A cleaning implement having controlled fluid absorbency

IS 2 175 487 T3

DESCRIPTION

Cleaning utensil with controlled fluid absorbency.

Technical field

This application refers to a cleaning implement useful in removing dirt from hard surfaces. The application relates in particular to a cleaning implement comprising a handle and a removable absorbent cleaning pad. The application also refers to the absorbent cleaning pad that is used with the cleaning implement. The cleaning pad exhibits the ability to absorb fluids at a controlled rate and retain absorbed fluids during the cleaning process.

Background of the invention

The literature is replete with products capable of cleaning hard surfaces, such as ceramic tile floors, hardwood floors, counter tops, and the like. In the context of floor cleaning, numerous devices are described which comprise a handle and some means for absorbing a fluid cleaning composition. Such devices include those that are reusable, including mops containing cotton cords, cellulose and / or synthetic strips, sponges, and the like. Although these mops are successful in removing many soils from hard surfaces, they typically require the inconvenience of performing one or more rinsing operations during use to avoid saturating the material with dirt, dirt, debris, etc. These mops therefore require the use of a separate container to perform the rinsing operation or operations to renew the utensil, and normally these rinsing operations are not successful in sufficiently removing dirt residues. This can result in the re-deposition of significant amounts of soil during subsequent mopping passes. In addition, as reusable mops are used for a long time, they are increasingly dirty and smelly. This has a negative effect on the subsequent cleaning efficiency.

To alleviate some of these negative attributes associated with reusable mops, attempts have been made to provide mops having disposable cleaning pads. For example, U.S. Patent No. 5,094,559, issued March 10, 1992 to Rivera et al., Describes a mop that includes a disposable cleaning pad that comprises a scrubbing or scouring pad to remove dirt from a mop. dirty surface, a drying layer to absorb fluid after the cleaning process, and a liquid impervious layer between the scrubbing and drying layers. The pad further contains a breakable package means located between the scrubbing layer and the liquid-impermeable layer. The breakable packages are positioned so that, after breakage, fluid is directed onto the surface to be cleaned. During the cleaning action with the scrubbing pad, the waterproof foil prevents fluid from moving into the absorbent drying pad. After the cleaning action is completed, the pad is removed from the mop handle and reattached in such a way that the drying layer comes into contact with the floor. Although this device can alleviate the need for multiple rinsing operations, it does require the user to physically handle the pad and reattach a wet, dirty pad in order to complete the cleaning process.

Similarly, US Patent 5,419,015, issued May 30, 1995 to Garcéa, describes a mop having removable, washable work pads. The pad is described with a top layer that is capable of being attached to hooks on a mop head, a center layer of synthetic microporous plastic foam, and a bottom layer for contacting the surface during the cleaning operation. It is stated that the composition of the undercoat depends on the end use of the device, ie washing, polishing or scrubbing. Although this reference faces problems associated with mops that require rinsing in use, the patent fails to provide a cleaning implement that sufficiently removes dirt that is deposited on typical domestic hard surfaces, particularly floors, such that the surface is perceived as essentially free of dirt.

In particular, the synthetic foam described by Garcéa for absorbing the cleaning solution has a relatively low absorbent capacity for water and aqueous solutions. Therefore, the user must either use small amounts of cleaning solution, so that they remain within the absorbent capacity of the pad, or the user must leave a significant amount of cleaning solution on the surface being cleaned. In any situation, the effectiveness of the cleaning pad is not optimal.

Although many known devices for cleaning hard surfaces are successful in removing a large majority of the dirt encountered by the typical consumer during the cleaning process, they are inconvenient and time consuming in requiring one or more cleaning / rinsing operations. Prior art devices that have addressed the issue of convenience and time savings typically do so at the cost of cleaning efficiency. As such, there remains a need for a device that offers both convenience and advantageous soil removal. Therefore, it is an object of the present invention to provide a cleaning implement comprising a removable cleaning pad, which alleviates the need to rinse the pad during use and provides a substantially dry result. In particular, it is an object of the present invention to provide a utensil comprising a removable cleaning pad with sufficient absorbent capacity, based on one gram of fluid absorbed per gram of cleaning pad, which allows cleaning a large surface, such as that of a typical soil with a hard surface (7.5-9.3 m²), without the need to renew or change the pad. It is an additional object provided

ES 2 175 487 T3 to create such a cleaning implement in which the pad offers advantageous soil removal properties. When the cleaning implement of the present invention is used in combination with a cleaning solution, it is a further object to provide an essentially dry end result.

The utensil of the present invention is designed to be compatible with all hard surface substrates, including wood, vinyl, linoleum, wax-free floors, ceramic, Formica®, porcelain, glass, wall panel, and the like. Summary of the invention

The present invention refers to a cleaning utensil comprising:

to. a handle; Y

b. a removable cleaning pad having average deionized water absorbency rate of no greater than about 0.5 g / s, when measured from t = 0 to t = 1200 seconds using the Performance Under Pressure (PUP) method; and an absorbent capacity at t1200 of at least about 1 g of deionized water per g of cleaning pad, when measured using the Performance Under Pressure method.

Although not limited to wet cleaning applications, the present invention is preferably used in combination with a cleaning solution. That is, although the utensil exists initially in a dry state, optimal cleaning efficiency for a typical hard surface will involve the use of a cleaning fluid that is applied to the soiled surface prior to cleaning with the present utensil. During the effort to develop the present cleaning implement, the applicants discovered that, surprisingly, a critical aspect of cleaning efficiency is that of controlling the absorbency rate of the fluid by the cleaning pad. That is, while it is important to absorb essentially all of the fluid cleaning solution during the time that a topical user cleans a surface, it is also important to avoid immediate absorption by the cleaning pad. This is generally contrary to the teachings of the prior art to which absorbent articles belong, where it is accepted that immediate, rapid absorbency is desired.

Avoiding rapid absorption allows the cleaning solution to be used more efficiently by emulsifying, diluting and transporting dirt on the pad. In this regard, the cleaning implement of the present invention allows cleaning of hard surfaces using low levels of cleaning solution, relative to the levels of solution required when using cleaning devices of the prior art. This provides numerous benefits, including a reduction in the cost of the cleaning solution necessary to carry out the cleaning operation. It has been found that by using a cleaning pad that has a controlled absorbency, excellent cleaning results can be achieved using dissolution levels no greater than about 67 ml of cleaning solution per square meter of area to be cleaned, while at the same time a pad is provided with a sufficiently high absorbent capacity to provide a substantially dry end result. Without wishing to be bound by theory, it is postulated that the controlled speed provided by the cleaning pad of the present invention allows an effective reservoir of fluid to be in contact with the ground, which helps to dilute and transport the dirt in the soil. pad, using fewer volumes of supplemental fluids than required by previous cleaning systems. As such, the present invention further relates to a method for cleaning a hard surface using low levels of a cleaning solution, the method comprising:

(i) apply the cleaning solution to the hard surface to be cleaned, at a level no greater than about 67 ml of cleaning solution per square meter of hard surface; and (ii) rubbing the hard surface with a cleaning utensil comprising:

to. a handle; Y

b. a removable cleaning pad having an absorbent capacity at t1200 of at least about 1 g of deionized water per g of cleaning pad.

Preferably, the method used about 5.6 to about 67 ml of cleaning solution per square meter of hard surface, more preferably about 22.4 to 44.8 ml per square meter. Preferably, the method involved the use of a cleaning pad having an absorbent capacity at t1200 of at least about 5 g / g, more preferably at least about 10 g / g, even more preferably at least about 20 g / g. g, and still more preferably at least about 30 g / g. It should be understood that the method also extends to the use of the cleaning pad as a product on its own (ie without a handle).

In addition to having the controlled rate of absorbency requirement, it is still important that the cleaning pad has the ability to absorb most of the fluid used. In this regard, a minimum overall absorbency is a requirement of the cleaning pad. This overall absorbency is also important as it allows the use of sufficient amounts of cleaning solution (to maximize the solution-soil interaction) and ensures that essentially all of the solution and solubilized soil are removed from the surface.

The handle useful in the present invention optionally comprised, at one end, a pivotally attached support head. The removable cleaning pad comprises:

i. a scrub coat;

ii. an absorbent layer that is preferably in direct fluid communication with the scrubbing layer; Y

ES 2 175 487 T3 iii. an optional attachment or attachment layer for releasably attaching the cleaning pad to the handle, preferably to the optional handle support head.

The present invention further relates to a method for cleaning a hard surface, comprising the step of rubbing the surface with an implement or pad of the present invention.

Brief description of the drawings

Figure 1 is a perspective view of a cleaning implement of the present invention, having a built-in fluid dispensing device.

Figure 1a is a perspective view of a cleaning implement of the present invention that does not have a built-in fluid dispensing device.

Figure 1b is a side view of the handle grip of the utensil shown in the figure

1st.

Figure 2 is a perspective view of a removable cleaning pad of the present invention.

Figure 3 is an exploded perspective view of the absorbent layer of a removable cleaning pad of the present invention.

Figure 4 is a cross-sectional view of one embodiment of a removable cleaning pad of the present invention.

Figure 5 represents a schematic view of an apparatus for measuring the Performance Under Pressure (PUP) of the removable cleaning pad.

Figure 6 depicts an enlarged sectional view of the piston / cylinder assembly shown in Figure 5.

Figure 7 depicts an exploded perspective view of another removable cleaning pad of the present invention.

Figure 8 depicts a perspective view of another removable cleaning pad of the present invention.

Detailed description

1. Definitions

As used herein, the term "comprising" means that the various components, ingredients, or steps can be used together in the practice of the present invention. Therefore, the term "comprising" encompasses the more restrictive expressions "consisting essentially of" and "consisting of".

As used here, the term "direct fluid communication" means that fluid can be transferred rapidly between two components or layers (eg, scrub layer and absorbent layer) of cleaning pad without substantial build-up, transport, or restriction. using an interposer. For example, tissues, nonwoven webs, construction adhesives, scrim, and the like, may be present between the two distinct components while maintaining "direct fluid communication", provided they do not essentially impede or restrict fluid as it passes from a component or layer to the other.

As used herein, the term "Z dimension" refers to the dimension orthogonal to the length and width of the cleaning pad of the present invention, or a component thereof. The Z dimension usually corresponds to the thickness of the cleaning pad or a pad component.

As used here, the term "XY dimension" refers to the plane orthogonal to the thickness of the cleaning pad, or a component thereof. The X and Y dimensions usually correspond to the length and width, respectively, of the cleaning pad or a component of the pad.

As used herein, the term "layer" refers to a member or component of a cleaning pad whose primary dimension is XY, that is, along its length and width. It is to be understood that the term layer is not necessarily limited to single layers or sheets of material. Thus, the layer may comprise laminates or combinations of various loamines or bands of the type of materials required. Therefore, the term "layer" includes the terms "layers" and "layered".

As used here, the term "hydrophilic" is used to refer to surfaces that can be wetted by aqueous fluids deposited on them. Hydrophilic and wettable characters are defined topically in terms of the contact angle and surface tension of the fluids and solid surfaces involved. This is explained in detail in the American Chemical Society publication Contact Angle, Wettability, and Adhesion, edited by Robert F. Gould (Copyright 1964), incorporated herein by reference. A surface is said to be wetted by a fluid (that is, it is hydrophilic) when either the contact angle between the fluid and the surface is less than 90 °, or when the fluid tends to spontaneously spread across the surface. , both conditions normally coexisting. Conversely, a surface is considered "hydrophobic" if the contact angle is greater than 90^° and the fluid does not spontaneously spread across the surface.

As used here, the term "chambray" (rough cotton fabric) means any durable material that provides texture next to contact with the surface of the scrubbing pad of the cleaning pad, and also has a sufficient degree of openness to allow the required movement of fluid into the absorbent layer of the cleaning pad. Suitable materials include materials that have a continuous open structure, such as wire mesh and synthetic screens. The open areas of these materials can be easily controlled by varying the number of interconnected threads that the mesh comprises, controlling the thickness of those interconnected threads, etc. Other suitable materials include those in which the texture is provided by a discontinuous pattern printed on a substrate. In this regard, a durable material (for example, a synthetic or resin) can be printed onto a substrate in a

ES 2 175 487 T3 continuous or discontinuous pattern, such as individual dots, brush-like filaments, and / or lines, to provide the required texture. Similarly, the continuous or discontinuous design can be printed on a release material which will then act as the scrim. These designs can be repetitive or they can be random. It will be understood that one or more of the solutions described to provide the desired texture can be combined to form the optional scrim material. The Z-direction height and open area of ​​the scrim and / or scrubbing substrate layer help to control (ie, retard) the rate of liquid flow into the absorbent core material. The height or Z-dimension of the scrim and / or scrubbing substrate helps to provide a means to control the volume of liquid in contact with the cleaning surface while at the same time controlling the rate of absorption of liquid into the absorbent core material. .

For the purposes of the present invention, a "top" layer of a cleaning pad is a layer that is relatively further away from the surface to be cleaned (i.e., in the context of the utensil, relatively closer to the handle of the utensil during use). The term "bottom" layer means, conversely, a layer of a cleaning pad that is relatively closer to the surface to be cleaned (i.e., in the context of the utensil, relatively further away from the handle of the utensil during use. ). As such, the scrub layer is the lowermost layer, and the absorbent layer is an upper layer relative to the scrub layer. The terms "top" and "bottom" are used analogously when referring to layers that are multiple (for example, when the scrub coat is a two-layer material).

All percentages, ratios, and proportions used herein are by weight, unless otherwise specified.

II. Cleaning tools

The cleaning utensil of the present invention comprises:

to. a handle preferably comprising, at one end, a pivotally attached support head; Y

b. a removable cleaning pad having average deionized water absorbency rate of not greater than about 0.5 g / s, when measured from t = 0 to t = 1200 seconds using the Performance Under Pressure method; and an absorbent capacity at t1200 of at least about 1 g of deionized water per g of cleaning pad, when measured using the Performance Under Pressure method.

As noted above, Applicants' discovery is based on the finding that a controlled rate of fluid reception by the absorbent pad improves overall cleaning efficiency. In particular, the cleaning pads have an average absorbency speed of no more than about 0.5 g / s, this average speed being calculated based on the speeds measured during the first 1200 seconds (hereinafter "average absorbency speed" ). The average absorbency rate is determined using the Performance Under Pressure method (hereinafter referred to as "PUP"), which is described in detail in the section Test Methods below. (Briefly, the PUP method measures an absorbency of the cleaning pad at different times under an initial confining pressure of 620 Pa (which reflects typical pressures in use during the cleaning operation)). Preferably, the average absorbency rate will be greater than about 0.3 g / s, more preferably not greater than about 0.2 g / s, and, still more preferably, not greater than about 0.1 g / s.

Although rapid uptake of fluid by the pad is required to be avoided for the cleaning pad to achieve the desired cleaning results, it is also necessary for the cleaning pad to absorb more of the fluid used during the cleaning process. As such, the cleaning pads will have an absorbent capacity at 1200 seconds (hereinafter referred to as "absorbent capacity at t1200") when measured using the PUP method, of at least about 1 gram of deionized water per gram of the pad. cleaning. Preferably, the cleaning pad will have an absorbent capacity at 1200 t of at least about 5 g / g, more preferably at least about 10 g / g, and, still more preferably, of at least about 20 g / g, and even more. preferably at least about 30 g / g.

The cleaning pads will preferably, but not necessarily, have a total fluid capacity (deionized water) of at least about 100 grams, more preferably at least about 200 grams, and most preferably at least about 300 grams. and, the most preferable, of at least 400 gr. Although pads having a total fluid capacity of less than 100 grams are within the scope of the invention, they are not as suitable for cleaning large areas, such as found in a typical home, as are larger capacity pads.

One skilled in the art will recognize that various materials can be used to carry out the claimed invention. Thus, while preferred materials for the various components of the utensil and cleaning pad are described below, it is recognized that the scope of the invention is not limited to such descriptions.

A. Mango

The handle of the cleaning tool will be made of any material that facilitates the grip of the cleaning tool. The handle of the cleaning implement will preferably consist of any elongated, durable material that provides practical cleaning. The length of the handle will be dictated by the end use of the utensil.

The handle will preferably comprise, at one end, a support head to which the cleaning pad can be releasably attached. For ease of use, the support head can be pivotably attached to the handle using known joint assemblies.

IS 2 175 487 T3

Any suitable means can be used to attach the cleaning pad to the support head, as long as the cleaning pad remains attached during the cleaning process. Examples of suitable fastening means include clamps, hooks and loops (for example Sailboat¹®) and the like. In a preferred embodiment, the support head comprised hooks on its lower surface, which were mechaonically attached to the top layer (preferably a different attachment or attachment layer) of the absorbent cleaning pad.

A preferred handle, comprising a fluid dispensing means, is depicted in Figure 1 and is fully described in US Patent 5,888,006 to Procter & Gamble. Another preferred handle, containing no fluid dispensing means, is depicted in Figures 1a and 1b, and is fully described in US Patent WO 98/12023.

B. Removable cleaning pad

In light of Applicants' discovery that controlled absorbency rates play an important role in the cleaning efficiency of the utensils of the present invention, one of skill in the art would recognize that the fluid absorption rate of the cleaning solution By the cleaning pad is dictated by the solution and the pad materials. In this regard, the volume flow (ie the rate of fluid uptake) can be calculated using Hagen Poiseuille's laminar flow law. The Hagen-Pouseuille law says that the volume flow, q, is calculated according to the following formula:

q = R²[(2γcosθ / R) -ρgL] / 8Lμ in which R is the radius of the tube, γ is the surface tension of the fluid being absorbed, θ is the contact angle at the fluid-solid interface, ρ is the density of the fluid, g is the gravitational constant, L is the wetted length of the tube, and μ is the viscosity of the fluid. From this equation it is evident that the absorbency rate of the cleaning pad is controllable, for example, by adjusting the pore size of the material constituting the cleaning pad, adjusting the surface wettability (cosθ) of the material for the absorbed fluid, etc. In conjunction with the teachings of the present disclosure, any of the well-known absorbent materials can be used and can be combined to achieve the desired initial delay of absorbency, except total absorbent capacity. Therefore, although representative materials and useful embodiments for the cleaning pad are described below, the invention is not limited to such materials and embodiments.

i. Scrubbing or scouring pad

The cleaning pad of the present invention would preferably comprise a scrubbing layer and an absorbent layer. The scrubbing layer is the part of the cleaning pad that comes into contact with the dirty surface during cleaning. As such, materials useful as a scrub coat must be durable enough for the coat to maintain its integrity during the cleaning process, without damaging the surface to be cleaned. Also, when the cleaning pad is used in combination with a solution, the scrub coat must be able to absorb liquids and dirt and release those liquids and dirt to the absorbent coat. This will ensure that the scrub coat is able to continually remove additional material from the surface being cleaned. Regardless of whether the utensil is used with a cleaning solution (that is, in the wet state) or without a cleaning solution (that is, in the dry state), the scrub coat, in addition to removing particulate matter, will facilitate other functions, such as polishing, dust suppression and polishing of the surface being cleaned.

The scrubbing layer may be a monolayer or a multi-layered structure, one or more of which layers may be split to facilitate scrubbing of the soiled surface and pick-up of particulate matter. This scrub coat, when passed over the soiled surface, interacted with the dirt (and the cleaning solution, when used), loosening and emulsifying tough soils and allowing them to pass freely into the absorbent layer of the pad. The scrubbing layer preferably contains openings (eg, grooves) that provide an easy passage for large particulate soil to move freely and become trapped within the absorbent layer of the pad. Low density structures are preferred for use as a scrubbing layer, to facilitate transport of particulate matter into the absorbent layer of the pad.

In order to provide the desired integrity, particularly suitable materials for the scrub coat include synthetic materials such as polyolefins (eg polyethylene and polypropylene), polyethers, polyamides, synthetic cellulosic substances (eg Rayon®) and mixtures thereof. Such synthetic materials can be manufactured using known processes, such as carding, spun bonding, meltblowing, airlaying, needle punching, and the like.

ii. Absorbent layer

The absorbent layer serves to retain any fluid and dirt absorbed by the cleaning pad during use. Although the scrubbing layer has some effect on the ability of the pad to provide the required fluid absorption rates, the absorbent layer plays an important role in achieving the absorption rates and overall absorbency of the present invention.

The absorbent layer would be able to remove fluid and dirt from the scrubbing layer so that the scrubbing layer would have the ability to continuously remove dirt from the surface. The absorbent layer must also be able to retain absorbed material under topical pressures in use to avoid "crushing out" of absorbed soil, cleaning solution, etc.

The absorbent layer consists of any material that is capable of absorbing fluids at required speeds, and of retaining such fluids during use. To achieve the desired layer6

In total fluid quantities, it is preferred to include in the absorbent layer a material having a relatively high capacity (in terms of grams of fluid per gram of absorbent material). As used herein, the term "superabsorbent material" means any absorbent material having a g / g capacity for water of at least about 15 g / g, when measured under a confining pressure of 2.1 kPa. Because most of the cleaning fluids useful with the present invention are water-based, it is preferred that the superabsorbent materials have a relatively high g / g capacity for water and aqueous fluids.

Representative absorbent materials include water-swellable, water-insoluble superabsorbent gelling polymers (referred to herein as "superabsorbent gelling polymers"), which are well known in the literature. These materials show very high absorbent capacities for water. The useful superabsorbent gelling polymers in the present invention may have varying sizes, shapes and / or morphologies over a wide range. These polymers can be in the form of particles that do not have a large ratio of maximum dimension to minimum dimension (e.g., granules, flakes, powders, aggregates between particles, cross-linked aggregates between particles, and the like) or they can be in the form of fibers, Leamines, films, foams, laminates, and the like. The use of superabsorbent gelling polymers in fibrous form provides the advantage of causing improved retention of the superabsorbent material, relative to the particles, during the cleaning process. Although their capacity is generally lower for water-based blends, these materials still show significant absorbent capacity for such blends. The patent literature is replete with descriptions of water swellable materials. See, for example, US Patents 3,699,103 (Harper et al.), Issued June 13, 1972; 3,770,731 (Harmon), issued June 20, 1972; Reissued Patent Re 32,649 (Brandt et al.), reissued April 19, 1989; 4,834,735 (Alemany et al.), Issued May 30, 1989.

Useful superabsorbent gelling polymers herein include a variety of water-insoluble, but water-swellable polymers capable of absorbing large amounts of fluids. Such polymeric materials are also commonly referred to as "hydrocolloids", and may include polysaccharides such as carboxymethyl starch, carboxymethyl cellulose, and hydroxypropyl cellulose; non-ionic types such as polyvinyl alcohol and polyvinyl ethers; cationic types such as polyvinyl pyridine, polyvinyl morpholinone, and N, N-dimethylaminoethyl or N, N-diethylaminopropyl acrylates and methacrylates, and their respective quaternary salts. Typically, the useful superabsorbent gelling polymers in the present invention have a plurality of aniogenic functional groups, such as sulphoenic acid, and, more typically, carboxy groups. Examples of suitable polymers for use herein include those prepared from polymerizable, unsaturated, acid-containing monomers. Thus, such monoemers include olepheneically unsaturated acids and anhydrides containing at least one carbon-to-carbon olefinic double bond. More specifically, these monoemers can be selected from olepheneically unsaturated carboxylic acid acids and anhydrides, olepheneically unsaturated sulphoenic acid acids, and mixtures thereof.

Some non-acid monomers may also be included, usually in minor amounts, in the preparation of the useful superabsorbent gelling polymers herein. Such non-acid monoemers may include, for example, esters of the acid-containing, water-soluble or water-dispersible monoomers, as well as monoeers that contain no carboxylic or sulpheonic acid groups at all. Optional non-acid monomer may therefore include monomer containing the following types of functional groups: carboxylic or sulphoenic acid esters, hydroxyl groups, amide groups, amino groups, nitrile groups, quaternary ammonium salt groups, aryl groups (for example, phenyl groups, such as those derived from styrene monoomer). These non-acidic monoemers are well known materials and are described in greater detail, for example, in US Patent 4,076,663 (Masuda et al.), Issued February 28, 1978, and US Patent 4,062. 817 (Westerman), issued December 13, 1997.

Olepheneically unsaturated carboxylic acid and carboxylic acid anhydride monomers include the acrylic acids typified by acrylic acid itself, methacrylic acid, ethacrylic acid, α-chloroacrylic acid, α-cyanoacrylic acid, α-methylcrylacrylic acid (β-crylacrylic acid). -phenylacrylic, e-acryloxypropionic acid, sorbic acid, α-chloroserbic acid, angelic acid, cinnamic acid, p-chlorokinamic acid, β-sterilacrylic acid, itaceonic acid, citracoenic acid, mesaceonic acid, glutaceonic acid, acontic acid, maleic acid, fumeric acid, tricarboxyethylene and maleic acid anhydride.

Olephenically unsaturated sulpheonic acid monomers include aliphatic or aromatic vinyl sulphene acids, such as vinyl sulphene acid, allyl sulphene acid, vinyl toluene sulphene acid and styrene sulphene acid; acrylic and methacrylic sulphoenic acid, such as sulfoethylacrylate, sulfoethyl methacrylate, sulfopropyl acrylate, sulfopropyl methacrylate, 2-hydroxy-3-methacryloxypropylsulpheonic and 2-acrylamide-2-methylpropane sulpheonic acid.

Preferred superabsorbent gelling polymers for use in the present invention contain carboxy groups. These polymers include hydrolyzed starch-acrylonitrile graft copolymers, partially neutralized and hydrolyzed starch-acrylonitrile graft copolymers, acrylic starch-acrylonitrile graft copolymers, partially neutralized acrylic acether-saponic acid starch-acetate graft copolymers, partially neutralized acrylic aceter-saponic vinyl ether copolymers. hydrolyzed acrylonitrile or acrylamide copolymers, lightly cross-linked network polymers of any of the prece7 copolymers

ES 2 175 487 T3 teeth, partially neutralized polyacrylic acid, and slightly crosslinked network polymers of partially neutralized polyacrylic acid. These polymers can be used either alone or in the form of a mixture of two or more different polymers. Examples of these polymeric materials are described in US Patents 3,661,875, 4,076,663, 4,093,776, 4,666,983, and 4,734,478.

The most preferred polymeric materials for use in the manufacture of superabsorbent gelling polymers are slightly cross-linked network polymers of partially neutralized polyacrylic acids and their starch derivatives. Most preferably, the hydrogel-forming absorbent polymers comprise from about 50 to about 95%, preferably about 75%, neutralized, slightly cross-linked polyacrylic acid (i.e., poly (sodium acrylate / acrylic acid) )). The crosslinking of the network renders the polymer essentially insoluble in water and determines, in part, the absorptive capacity and extractable polymer content characteristics of superabsorbent gelling polymers. Procedures for network crosslinking of these polymers, and typical network crosslinking agents, are described in detail in US Patent 4,076,663.

Although the superabsorbent gelling polymers are preferably of a single type (ie, homogeneous), blends of polymers can also be used in the utensils of the present invention. For example, blends of starch-acrylic acid graft copolymers and partially neutralized polyacrylic acid lightly crosslinked network polymers can be used in the present invention.

Although any of the superabsorbent gelling polymers described in the prior art may be useful in the present invention, it has recently been recognized that when significant values ​​(e.g., more than about 50% by weight of the absorbent structure) of superabsorbent gelling polymers, and in particular when one or more regions of the absorbent layer comprises more than about 50% by weight of the region, the problem of gel blocking by swollen particles can prevent fluid circulation, thereby adversely affecting the ability of the polymers. of gelation to absorb to its full capacity in the desired period of time. US Patent 5,147,343 (Kellenberger et al.), Issued September 15, 1992, and US Patent 5,149,335 (Kellenberger et al.), Issued September 22, 1992, describe superabsorbent gelling polymers. in terms of their Absorbency Under Load (AUL), where the gelling polymers absorb fluids (0.9% saline solution) under a confining pressure of 2.1 kPa. Methods for determining AUL are described in these patents. The polymers disclosed therein may be particularly useful in embodiments of the present invention that contain regions of relatively high values ​​of superabsorbent gelling polymers. In particular, when high concentrations of superabsorbent gelling polymer are incorporated into the cleaning pad, these polymers will preferably have an AUL, measured according to the methods described in US Patent 5,147,343, of at least about 24 ml / ml. gr, preferably at least 27 ml / gr, after 1 hour; or an AUL, measured according to the methods described in US patent 5,149,335, of at least about 15 ml / g, more preferably at least about 18 ml / g after 15 minutes. Commonly assigned U.S. Patent 5,599,335 (Goldman et al.), Filed March 29, 1994, and U.S. Patent 5,562,646 (Goldman et al.), Filed April 6, 1995, are contested. They also address the gel blocking problem and describe superabsorbent gelling polymers useful for overcoming this phenomenon. These patents specifically describe superabsorbent gelling polymers that prevent gel blocking even at higher confining pressures, specifically 4.8 kPa. In embodiments of the present invention where the absorbent layer contains regions comprising high values ​​(eg greater than about 50% by weight of the region) of superabsorbent gelling polymer, it may be preferred that the superabsorbent gelling polymer either as described in the aforementioned Goldman et al. patents.

In addition to the contribution to overall fluid absorbency, the superabsorbent material also directly affects the absorbency rate of the pad. As such, when particulate superabsorbent gelling polymers are employed, the skilled person will recognize that the absorbency rate of the fluid by the cleaning pad can be controlled by adjusting, for example, the mean particle size and / or size distribution. of the material particles.

Other useful superabsorbent materials include hydrophilic polymeric foams, such as those described in commonly assigned U.S. Patent 5,650,222 (DesMarais et al.), Issued July 22, 1995, and U.S. Patent 5,387,207 (Dyer et al), issued on February 7, 1995. These references describe hydrophilic polymeric absorbent foams made by polymerizing a high internal phase water-in-oil emulsion (commonly referred to as HIPE). These foams are easily structured to provide variable physical properties (pore size, capillarity, suction, density, etc.) that affect fluid handling ability. As such, these materials are particularly useful, either alone or in combination with others, such as foams or with fibrous structures, in providing the overall capacity required by the present invention.

When superabsorbent material is included in the absorbent layer, the absorbent layer will preferably comprise at least about 15% by weight of the absorbent layer.

ES 2 175 487 T3 preferably at least about 20% and most preferably at least 25% of the superabsorbent material.

The absorbent layer may also consist of, or comprise, fibrous material. Useful fibers in the present invention include naturally occurring fibers (modified or unmodified), as well as synthetically made fibers. Examples of suitable naturally occurring, unmodified / modified fibers include cotton, esparto grass, bagasse, coarse hair wool, linen, silk, wool, wood pulp, chemically modified wood pulp, jute, ethyl cellulose and cellulose acetate. Suitable synthetic fibers can be manufactured from polyvinyl chloride, polyvinyl fluoride, polytetrafluoroethylene, polyvinylidene chloride, polyacrylics such as ORLON®, polyvinyl acetate, Rayon®, poly ( ethylene-vinyl acetate), insoluble or soluble polyvinyl alcohol, polyolefins such as polyethylene (for example, PULPEX®) and polypropylene, polyamides such as nylon, polyesters such as DACRON® or KODEL®, polyurethanes, polystyrenes, and Similar. The absorbent layer may comprise only naturally occurring fibers, only synthetic fibers, or any compatible combination of naturally occurring or synthetic fibers.

The useful fibers herein may be hydrophilic, hydrophobic fibers, or they may be a combination of hydrophilic and hydrophobic fibers. As noted above, the particular selection of hydrophilic or hydrophobic fibers will depend on the other materials included in the absorbent (and, to some extent, scrub) layer. That is, the nature of the fibers will be such that the cleaning pad exhibits the necessary fluid retardation and overall fluid absorbency. Hydrophilic fibers suitable for use in the present invention include cellulose fibers, modified cellulose fibers, rayon, polyester fibers such as hydrophilic nylon (HYDROFIL®). Suitable hydrophilic fibers can also be made by hydrophilizing hydrophobic fibers, such as surfactant-treated or silica-treated thermoplastic fibers, derived from, for example, polyolefins, such as polyethylene or polypropylene, polyacrylics, polyamides, polystyrenes, polyurethanes, and the like.

Suitable wood pulp fibers can be obtained from well known chemical processes, such as the Kraft and sulfite processes. It is especially preferred to obtain these southern softwood pulp fibers because of their superior absorbency characteristics. These wood pulp fibers can also be obtained in mechanical processes, such as ground wood, mechanical refiner, thermo-mechanical, chemical-mechanical and chemical-thermal-mechanical processes. Recycled or secondary wood pulp fibers can be used, as well as bleached and unbleached wood pulp fibers.

Another type of hydrophilic fibers for use in the present invention are chemically rigid made cellulosic fibers. As used herein, the term "chemically stiff cellulosic fibers" means cellulosic fibers that have been chemically stiffened to increase the stiffness of the fibers under both dry and aqueous conditions. Such means may include the addition of a chemical stiffening agent which, for example, coats and / or permeates the fibers. Such means may also include stiffening the fibers by altering the chemical structure, for example by crosslinking of polymeric chains.

When the fibers are used as the absorbent layer (or a constituent component thereof), the fibers can optionally be combined with a thermoplastic material. After melting, at least a part of this thermoplastic material migrates to the intersections of the fibers, usually due to capillary gradients between fibers. These intersections are places of attachment for the thermoplastic material. When cooled, the thermoplastic materials at these intersections solidify to form the bonding sites that hold the matrix or web of fibers together in each of the respective layers. This can be beneficial in providing additional overall integrity to the cleaning pad.

Among its various effects, bonding at fiber intersections increases the overall compression modulus and strength of the resulting thermally bonded member. In the case of cellulose fibers made chemically rigid, the melting and emigration of the thermoplastic material also have the effect of increasing the average pore size of the resulting web or sheet, while maintaining the density and base weight of the material. still band was originally formed. This can improve the fluid receiving properties of the thermally bonded web after initial exposure to fluid, due to improved fluid permeability, and after subsequent exposure, due to the combined ability of the stiffened fibers to maintain their stiffness after exposure. wetting and the ability of the thermoplastic material to remain attached at the fiber intersections after wetting and after compression in wet. Lastly, the thermically bonded bands of stiffened fibers maintain their original overall volume, but the volumetric regions previously occupied by the thermoplastic material remain open, thus increasing the average size of capillary pores between fibers.

Useful thermoplastic materials in the present invention can be in any of a variety of forms, including in particles, fibers, or combinations of particles and fibers. Thermoplastic fibers are particularly preferred because of their ability to form numerous inter-fiber bonding sites. Suitable thermoplastic materials can be formed from any thermoplastic polymer that can be melted at temperatures that do not extensively damage the fibers of which the primary web or matrix of each layer is made. Preferably, the melting point of this thermoplastic material will be less than about 190^°C, and I will preferably be between about 75^°C and about 175^°C. In any case, the melting point of this thermoplastic material must not be lower.

ES 2 175 487 T3 at the temperature at which the thermally bonded absorbent structures are likely to be stored, when used in cleaning pads. The melting point of thermoplastic material is normally not less than about 50^°C.

Thermoplastic materials, and in particular thermoplastic fibers, can be made from a variety of thermoplastic polyomers including polyolefins such as polyethylene (for example, PULPEX®) and polypropylene, polyethers, copolyethers, polyvinyl acetate, poly ( ethyl vinyl acetate), poly (vinyl chloride), poly (vinylidene chloride), polyacrylics, polyamides, copolyamides, polystyrenes, polyurethanes and copolymers of any of the foregoing, such as vinyl chloride / vinyl acetate, and the like. Depending on the characteristics desired for the resulting thermally bonded absorbent member, suitable thermoplastic materials include hydrophobic fibers that have been made hydrophilic, such as solid-treated or surfactant-treated thermoplastic fibers, derived, for example, from polyolefins such as polyethylene or polypropylene. , polyacrylics, polyamides, polystyrenes, polyurethanes and the like. The surface of the hydrophobic thermoplastic fiber can be made hydrophilic by treatment with a surfactant, such as a nonionic or anionic surfactant, for example, by spraying the fiber with a surfactant, by immersion in a surfactant, or by including the surfactant. as part of the polymer melt in the production of thermoplastic fiber. After melting and resolidification, the surfactant tended to remain on the surface of the thermoplastic fiber. Suitable surfactants include nonionic surfactants, such as Brij® 76, manufactured by ICI Americas, Inc., of Wilmington, Delaware, and various surfactants sold under the Pegosperse® trademark by Glyco Chemical, Inc., of Greenwich, Connecticut. . In addition to non-ionic surfactants, they can also be used in anioonic surfactants. These surfactants can be applied to thermoplastic fibers at values ​​of, for example, about 0.2 to about 1 g per square centimeter of thermoplastic fiber.

Appropriate thermoplastic fibers can be made from one single polymer (monocomponent fibers), or they can be made from more than one polymer (eg, bicomponent fibers). As used here, "bicomponent fibers" refers to thermoplastic fibers that comprise a core fiber made from one polymer that is encapsulated within a thermoplastic sheath made from a different polymer. The polymer comprising the cladding frequently melts at a different, usually lower, temperature than the polymer constituting the core. As a consequence, these bicomponent fibers provide thermal bonding due to the sheath polymer fusion, while maintaining the desirable strength characteristics of the core polymer.

Bicomponent fibers suitable for use in the present invention may include sheath / core fibers having the following polymer combinations: polyethylene / polypropylene, poly (ethyl vinyl acetate) / polypropylene, polyethylene / polyester, polypropylene / polyeoster, copolyester / polyester. , and the like. Particularly suitable bicomponent thermoplastic fibers for use here are those with a polypropylene or polyester core, and a lower melting point copolyethene, poly (ethyl vinyl acetate) or polyethylene sheath (for example those available from Danaklon a / s , Chisso Corp. and CELBOND®, available from Hercules). These bicomponent fibers can be concentric or eccentric. As used here, the terms "concoentric" and "eccentric" refer to whether the sheath has a thickness that is uniform, or uneven, across the cross-sectional area of ​​the bicomponent fiber. Eccentric bicomponent fibers may be desirable to provide greater resistance to compression at lower fiber thicknesses.

Methods for preparing thermically bonded fibrous materials are described in US Patent 5,607,414 (Richards et al.), Issued March 4, 1997 (see especially pages 16-20), and US Patent 5,549,589. (Horney et al.), Issued August 27, 1996 (see especially columns 9 and 10).

The absorbent layer may also comprise a hydrophilic, polymeric foam derived from HIPE, which does not have the high absorbency of those previously described as "superabsorbent materials." Such foams and methods for their preparation are described in US Patent 5,550,167 (DesMarais), issued August 27, 1996; and US Patent 5,563,179, commonly assigned (Stone et al.), issued October 8, 1996.

The absorbent layer of the cleaning pad may be composed of a homogeneous material, such as a mixture of cellulosic fibers (optionally bonded or thermically bonded) and particulate swellable superabsorbent gelling polymer. Alternatively, the absorbent layer may be composed of discrete layers of material, such as a theoretically bonded layer of airlaid material, and a discrete layer of a superabsorbent material. For example, a thermally bonded layer of cellulosic fibers may be located lower than (ie, below) the superabsorbent material (ie, between the superabsorbent material and the scrubbing layer). In order to achieve high fluid absorption and retention capacity under pressure, while at the same time providing the initial delay in fluid uptake, it may be preferable to use such discrete layers when forming the absorbent layer. In this regard, the superabsorbent material can be located remote from the scrubbing layer by including a less absorbent layer as the lowermost aspect of the absorbent layer. For example, a layer of cellulosic fibers may be positioned lower (ie, below) than the superabsorbent material (ie, between the superabsorbent material and the scrubbing layer).

IS 2 175 487 T3

In a preferred embodiment, the absorbent layer will comprise a heat bonded, air laid web of cellulose fibers (Flint River, available from Weyerhaeuser, Wa) and AL Thermal C (thermoplastic available from Danaklon a / s Varde, Denmark), and a swellable, hydrogel-forming, superabsorbent polymer. The superabsorbent polymer is preferably incorporated such that a discrete layer is located near the surface of the absorbent layer that is distant from the scrubbing layer. Preferably, a thin layer of, for example, cellulose fibers (optionally heat bonded) was placed on top of the superabsorbent gelling polymer to improve containment.

iii. Optional holding layer

The cleaning pads of the present invention will optionally have an attachment layer that would allow the pad to be attached to the handle of the utensil or to the support head on preferred utensils. The fastening layer would be necessary in those embodiments where an absorbent layer is used, but is not suitable for attaching the pad to the handle support head. The fastening layer can also act as a means to prevent fluid from flowing across the top surface (i.e., the handle contacting surface) of the cleaning pad, and can further provide improved integrity to the pad. As with the scrubbing and absorbent layers, the hold-down layer may consist of a single-layer or multi-layer structure, provided it meets the above requirements.

In a preferred embodiment of the present invention, the fastening layer will comprise a surface that is capable of being mechanically attached to the support head of the handle through the use of known hook and loop technology. In one such embodiment, the attachment layer would comprise at least one surface that can be mechanically attached to hooks that are permanently attached to the lower surface of the handle support head.

To achieve the desired fluid impermeability and holding ability, it is preferred that a laminated structure is used comprising, for example, a nonwoven, fibrous, melt blown film structure. In a preferred embodiment, the tie layer is a three-layer material having a layer of melt blown polypropylene film positioned between two spun bonded polyethylene layers.

III. Cleaning pad

Although the cleaning pads of the present development are particularly suitable for use in the cleaning implements described above, the ability to control the absorption of fluid, followed by the subsequent reception and retention of significant amounts of fluid, imparts to the cleaning pads a utility independent of combining it with a handle to form a utensil, such as a mop. As such, the cleaning pads themselves can be used without being attached to a handle. Therefore, they can be constructed without the need for them to be attached to a handle. However, it may be desirable to construct the cleaning pads in such a way that they can be used either in combination with the handle or as a stand-alone product. Therefore, it may be preferred to prepare the pads with an optional fastening layer. In all other respects, the cleaning pad is essentially as described above. Of course, when the cleaning pad is designed to clean hard surfaces of smaller dimensions than domestic floors (for example, countertops, sinks, kitchen surfaces, plumbing, etc.), such pads can be obtained with relatively smaller overall capacities. .

IV. Other aspects and specific embodiments of the invention

When the cleaning pad is made up of discrete layers, the various layers can be bonded or bonded together using any means that provide the pad with sufficient integrity during the cleaning process. The scrubbing and fastening layers, when present, can be attached to the absorbent layer or to each other by any of a variety of bonding means, including the use of a uniform continuous layer of adhesive, a patterned layer of adhesive, or any series of separate lines, spirals, or dots of adhesive. Alternatively, the bonding means may consist of heat bonding, pressure bonding, ultrasonic bonding, mechanical dynamic bonding, or any other appropriate bonding means or combinations of these bonding means, as they are known in the art. The bond can be around the perimeter of the cleaning pad (for example, by heat welding the scrub layer and optional fastening layer), and / or across the area (i.e. the XY plane) of the scrub pad. so that a pattern is formed on the surface of the cleaning pad. The joining of the layers of the cleaning pad with ultrasoin bonds across the area of ​​the pad provides integrity to prevent shearing of the individual layers of the pad during use.

The cleaning pad of the present invention will be able to retain absorbed fluid, even under the pressures exerted during the cleaning process. This is referred to herein as the ability of the cleaning pad to prevent "crushing" of absorbed fluid or, conversely, as the ability to retain absorbed fluid under pressure. The method for measuring crush expulsion is described in the Assay Methods section. Briefly, the test measures the ability of a saturated cleaning pad to retain fluid when subjected to a pressure of 1.72 kPa. Preferably, the cleaning pads of the present invention will have a squeeze-out value of no more than about 40%, more preferably no more than about 25%, still more preferably no more than about 15%, and, more preferable, not greater than 10%, approximately.

IS 2 175 487 T3

The cleaning implement of the present invention is preferably used in combination with a cleaning solution. The cleaning solution can consist of any known hard surface cleaning composition. Hard surface cleaning compositions are typically water-based solutions comprising one or more of surfactants, solvents, builders, chelators, polyomers, suds suppressors, enzymes, etc. Suitable surfactants include anioonic, nonionic, zwitterionic, amphoteric and cationic surfactants. Examples of anioonic surfactants include, but are not limited to, linear alkylbenzene sulfonates, alkyl sulfates, alkyl sulfonates, and the like. Examples of nonionic surfactants include alkyl ethoxylates, alkylphenol ethoxylates, alkylpolyglucosides, alkylglucamines, sorbitan osters, and the like. Examples of zwitterionic surfactants include betaones and sulfobetaones. Examples of amphoteric surfactants include derived materials utilizing imidazole cheomics, such as alkylampho-glycinates, and alkyl imino-propionate. Examples of cationic surfactants include mono-, di-tri-ammonium surfactants. All of the above materials are commercially available, and are described in Vol. 1 from McCutcheon: Emulsifiers and Detergents, North American Ed., McCutheon Division, MC Publishing Co., 1995.

Suitable solvents include short chain (for example C1-C6) derivatives of oxyethylene glycol and oxypropylene glycol, such as mono- and diethylene glycol n-hexyl ether, mono-, di- and tripropylene glycol n-butyl ether, and the like. Appropriate builders include those derived from phosphorous sources, such as orthophosphate and pyrophosphate, and non-phosphorous sources, such as nitrile-triacoetic acid, S-acid, S-ethylenediamine-disucconic acid, and the like. Suitable chelators include ethylenediaminetetraacetic acid and choric acid, and the like. Suitable polyomers include those that are anioonic, cationic, zwitterionic, and non-ionic. Suitable suds suppressors include silicone polyomers and linear or branched fatty acids or alcohols of C10-C18. Suitable enzymes include lipases, proteases, amylases, and other enzymes known to be useful for soil degradation catalysis.

A suitable cleaning solution for use with the present implement comprises about 0.1% to 2.0% of a linear alcohol ethoxylate surfactant (eg, Neodol 91-5®, available from Shell Chemical Co.); from about 0 to 2.0% of an alkylsulfonate (eg Bioterge PAS-8s, a linear C8 sulfonate, available from Stepan Co.); from about 0 to 0.1% potassium hydroxide; from about 0 to 0.1% potassium carbonate or bicarbonate; from about 0 to 10% organic acids; optional adjuvants, such as dyes and / or perfumes; and about 99.9 to 90% deionized or softened water.

When the superabsorbent polymer material is used in the cleaning pad, it is possible to control the rate of fluid uptake by controlling the pH of the cleaning solution. In particular, when such polyomers are present, the cleaning solution will preferably have a pH of no greater than about 9, preferably a pH of no greater than about 7, even more preferably a pH of no greater than about 5, and more preferably a pH of no more than about 5. from about 2 to about 5.

Referring to the figures, which depict the cleaning pads of the present invention, Figure 2 is a perspective view of a removable cleaning pad 200 comprising a scrubbing layer 201, a holding layer 203 and an absorbent layer 205 located between the scrubbing layer and the fastening layer. As indicated above, although Figure 2 represents each layer 201, 203 and 205 as a single layer of material, one or more of these layers may consist of a laminate of two or more sheets. For example, in a preferred embodiment, scrub layer 201 is a laminate of two sheets of carded polypropylene, where the bottom layer sits. Also, although not shown in Figure 2, materials that do not have fluid circulation can be located between the scrub layer 201 and the absorbent layer 203 and / or between the absorbent layer 203 and the support layer 205. However, It is important that the scrub and absorbent layers are in communication with essential fluid to provide the required absorbency of the cleaning pad. Although Figure 2 depicts the pad 200 with all the pad layers being the same size in the X and Y dimensions, it is preferred that the scrub layer 201 and the fastening layer 205 are larger than the absorbent layer, such that layers 201 and 205 can be bonded together around the periphery of the pad to provide integrity. The scrubbing and holding layers can be attached to the absorbent layer or to each other by any of a variety of bonding means, including the use of a uniform continuous layer of adhesive, a patterned layer of adhesive, and any series of lines, spirals or separate dots of adhesive. Alternatively, the attachment means may consist of heat bonding, pressure bonding, ultrasonic bonding, mechanical dynamo bonding, or any other appropriate bonding means or combinations of these bonding means, as known in the art. Bonding can be made around the perometer of the cleaning pad and / or across the surface of the cleaning pad so that a pattern is formed on the surface of the scrubbing layer 201.

Figure 3 is an exploded perspective view of absorbent layer 305 of one embodiment of a cleaning pad of the present invention. Specifically, the absorbent layer 305 is shown as a single or discrete layer of particulate superabsorbent gelling material, shown as 307, positioned between two individual layers 306 and 308 of fibrous material. In this embodiment, due to the region 307 of high concentration of superabsorbent gelling material, it is preferred that the superabsorbent material does not exhibit blockage.

ES 2 175 487 T3 gel explained above. In a particularly preferred embodiment, each of the fibrous layers 306 and 308 will be a thermally bonded fibrous substrate of cellulosic fibers, and the lower fibrous layer 308 will be in direct fluid communication with the scrubbing layer (not shown).

FIG. 4 is a cross-sectional view of the cleaning pad 400 having a scrubbing layer 401, a fastening layer 403, and an absorbent layer 405 located between the scrubbing and bonding layers. Cleaning pad 400 is shown here with a smaller absorbent layer 405, in dimensions X and Y, than scrub layer 401 and hold layer 403. Layers 401 and 403 are therefore depicted as bonded together along the periphery of the cleaning pad. Also, in this embodiment, the absorbent layer 405 is represented with two individual layers 405a and 405b. In a preferred embodiment, top layer 405a is a hydrophilic polymeric foam material, as described in commonly assigned patent, US 5,650,222 (DesMarais et al.), Issued July 22, 1995; and the bottom layer 405b is a polymeric foam material, such as that described in US Patent 5,550,167 (DesMarais), issued August 27, 1996, or in commonly assigned US Patent 5,563,179 ( Stone et al.), Issued October 8, 1995. As described above, each of the layers 405a and 405b can be formed using two or more individual layers of the respective material.

Figure 7 is a perspective view of a cleaning pad 600 having an optional scrim material 602. This scrim material 602 is depicted as a separate material located between the scrubbing layer 601 and the absorbent layer 605. In another embodiment , the scrim 602 may be in the form of a resin or other synthetic material printed on the scrub layer 601 (preferably the upper surface) or the absorbent layer 605 (preferably the lower surface). Figure 7 also depicts an optional holding layer 603 that is positioned on top of absorbent layer 605. As explained above, the scrim can provide improved cleaning of soils that are not readily solubilized by the cleaning solution used, if any. The relatively open structure of the scrim 602 provides the necessary fluid communication between the scrub layer 601 and the absorbent layer 605 to provide the required absorbency values ​​and capacity. Also, although Figure 7 depicts each of layers 601, 603, and 605 as a single layer of material, one or more of these layers may consist of two or more sheets.

Although Figure 7 depicts the pad 600 with all the pad layers being equal in size in the X and Y dimensions, it is preferred that the scrub layer 601 and the fastening layer 603 are larger than the absorbent layer, such that layers 601 and 603 can be bonded together around the periphery of pad 600 to provide integrity. It may also be preferred that the scrim material 602 be of equal size in at least one of the X or Y dimensions, to facilitate bonding at the periphery of the pad with the scrub layer 601 and the support layer 603. This is done. particularly preferred when the scrim material is a distinct layer (ie not printed on a substrate). In those embodiments where the scrim is created by printing, for example, a resin on a substrate, it may not be important that the scrim is positioned such that it is part of the peripheral joint. The scrub layer 601, the scrim 602 and the support layer 603 can be attached to the absorbent layer or to each other by any of a variety of means of attachment, including the use of a uniform and continuous adhesive layer, a layer of patterned adhesive or any series of separate lines, spirals, or dots of adhesive. Alternatively, the attachment means may consist of heat bonding, pressure bonding, ultrasonic bonding, mechanical dynamic bonding or any other appropriate bonding means or combinations of these bonding means, as are known in the art. Bonding can be made around the perimeter of the cleaning pad and / or across the surface of the cleaning pad so that a pattern is formed on the surface of the scrub coat 601.

Figure 8 is a perspective view of a preferred embodiment of pad 700 comprising a scrim 702. Figure 8 shows an absorbent layer 705, a fastening layer 703, and a scrub layer 701 that is partially peeled away to facilitate illustration of the chambray 702. (Chambray 702 may be a separate layer of material or it may be a component of the scrubbing layer or absorbent layer). Pad 700 is shown with a lower hard surface contacting surface 700a and an upper utensil contacting surface 700b. Pad 700 has two opposite side edges 700c, corresponding to the "X" dimension of the pad, and two opposite end edges 700d, corresponding to the "Y" dimension of the pad. (In use, when pad 700 is rectangular in the XY dimension, the typical cleaning movement will generally be in the "back-to-front direction" indicated by arrow 710). As illustrated, in this preferred embodiment, the scrim 702 extends to the extreme edges 700d to allow attachment to the fastening layer 703 and the scrubbing layer 701 (although not shown as such, the absorbent layer 705 will preferably be more cuts in dimensions X and Y, to facilitate the joining of the chambray and the layers of joining and scrubbing). However, the scrim 702 does not extend to the side edges 700c. The termination of the scrim 702 in front of the side edges 700c provides the pad 700 with regions 711 of scrub coat 701 that do not have the texture of scrim 702 and are therefore relatively smooth. These 711 smooth regions allow for uniform soil / solution removal during the cleaning process.

V. Test methods A. Behavior under pressure

This test determines the capacity to absorb13

ES 2 175 487 T3 is in gram / gram, and the average absorbance rate in g / s of deionized water for a cleaning pad that is laterally confined in a piston / cylinder assembly under an initial confining pressure of 0.6 kPa. (Depending on the composition of the cleaning pad sample, the confining pressure may decrease slightly as the sample absorbs water and swells during the time of the test). The objective of the test is to determine the average speed of the cleaning pad to absorb fluid, in a sensible period of time, when the pad is exposed to conditions of use (capillary action and horizontal pressures).

The test fluid for the PUP capacity test is deionized water. This fluid is absorbed by the cleaning pad under demand absorption conditions at hydrostatic pressure close to zero.

An appropriate apparatus 510 for this test is shown in Figure 5. At one end of this apparatus is a fluid reservoir 512 (such as a petri dish) having a cover 514. The reservoir 512 rests on an analytical balance generally indicated with 516. The other end of apparatus 510 is a sintered or fritted funnel, generically indicated 518, a piston / cylinder assembly generically indicated 520, which fits inside funnel 518, and the cylindrical plastic cover of the sintered funnel, generally indicated with 522, which fits over funnel 518 and is open at the bottom and closed at the top, the top having a pin hole. The 510 apparatus has a system for transporting fluid in either direction, consisting of sections of glass capillary tubing, indicated as 524 and 531a, flexible plastic tubing (for example, Tygon tubing with an inner diameter of 0.635 cm and an outer diameter of 0.952 cm). indicated as 531b, stopcock assemblies 526 and 538 and Teflon connectors 548, 550 and 552 to connect glass tubing 524 and 531a and stopcock assemblies 526 and 538. The 526 stopcock assembly consists of a 528 3-way valve, 530 and 534 glass capillary tubing in the main fluid system, and a 532 glass capillary tubing section to fill reservoir 512 and then flood the sintered disk. in the sintered funnel 518. The stopcock assembly 538 similarly consists of a 3-way valve 540, glass capillary lines 542 and 546 in the main fluid line, and a glass capillary line section 544 that acts as a drain for the system.

Referring to Figure 6, assembly 520 consists of a cylinder 554, a cup-like piston, indicated by 556, and a weight 558 that fits inside piston 556. Attached to the lower end of cylinder 554 is a screen 559. stainless steel canvas, N mesh^° 400, which is biaxially stretched to tension before clamping. The cleaning pad sample, generally indicated 560, is applied to the 559 screen with the surface contacting (or scrubbing) layer in contact with the 559 screen. (If the sample from which the cleaning pad is cut is designed so that both of its surfaces are to be in contact with the surface during the cleaning operation, the surface that is primarily intended for the initial scrubbing action should be in contact with the 559 sieve). The cleaning pad sample is a circular sample having a diameter of 5.4 cm. (Although sample 560 is represented as a single layer, the sample will actually consist of a circular sample that has all the layers contained in the pad from which the sample is cut). The 554 cylinder is drilled by a transparent LEXAN® rod (or equivalent) and has an inside diameter of 6.00 cm (area = 28.25 cm²), with a wall thickness of approximately 5 mm and a height of approximately 5 cm. The 556 piston is shaped like a Teflon cup and is machined to fit the 554 cylinder within tight tolerances. The cylindrical stainless steel 558 weight is machined to fit tightly inside the 556 piston and is mounted with a handle on top (not shown) for ease of removal. The combined weight of the piston 556 and the weight 558 is 145.3 g, which corresponds to a pressure of 620 Pa for an area of ​​22.9 cm.².

The components of the apparatus 510 are dimensioned in such a way that the flow rate of deionized water through it, under a hydrostatic head of 10 cm, is at least 0.01 g / cm²/ sec, where the flow rate is normalized by the area of ​​the sintered funnel 518. Particularly impacting factors in the flow rate are the permeability of the sintered disk in the sintered funnel 518, and the inside diameters of the glass pipes 524, 530, 534, 542 , 546 and 531a, and stopcock valves 528 and 540.

The deposit 512 is placed on an analytical balance 516 that is accurate to at least 0.01 g with a drift of less than 0.1 g / hr. The balance is preferably interconnected to a computer with programming that can: (i) monitor the change in weight of the balance at predetermined time intervals from the initiation of the PUP test; and (ii) be set to automatically start at a weight change of 0.01-0.05 g, depending on the sensitivity of the balance. Capillary tubing 524 entering reservoir 512 must contact neither the bottom of the reservoir nor the cover 514. The volume of fluid (not shown) in reservoir 512 must be sufficient so that no air is blown into the reservoir. capillary line 524 during measurement. The fluid level in reservoir 512, at the beginning of the measurement, should be approximately 2 mm below the top surface of the sintered disk of sintered funnel 518. This can be confirmed by placing a small drop of fluid on the sintered disk and gravimetrically monitoring its slow reflux into reservoir 512. This level should not change significantly when piston / cylinder assembly 520 is placed within funnel 518. The reservoir has to have a sufficiently large diameter (for example, about 14 cm) so that the extraction of parts of approximately 40 ml will give

ES 2 result in a change in fluid height of less than 3 mm.

Before measurement, the assembly is filled with deionized water. The sintered disk in sintered funnel 518 is then flooded so that it is filled with fresh deionized water. Where possible, air bubbles are removed from the bottom surface of the sintered disk and from the system connecting the funnel to the tank. The following processes are carried out by sequential operation of the 3-way stopcocks:

1. Excess fluid on the upper surface of the sintered disk is removed (eg, poured) from the sintered funnel 518.

two. Adjust the height / weight of solution in reservoir 512 to the proper level / value.

3. Sintered funnel 518 was positioned at the correct height relative to reservoir 512.

Four. The sintered funnel 518 is then covered with the sintered funnel cover 522.

5. Reservoir 512 and sintered funnel 518 are balanced with valves 528 and 540 of stopcock assemblies 526 and 538 in the open position.

6. Then valves 528 and 540 are closed.

7. Valve 540 is then rotated so as to open the funnel for drainage through tube 544.

8. The system is allowed to equilibrate in this position for 5 minutes.

9. Then valve 540 is turned back to its closed position.

Steps 7-9 temporarily "dry" the surface of sintered funnel 518 by exposing it to a small hydraulic suction of —5 cm. This suction is applied if the open end of tube 544 extends —5 cm below the level of the sintered disk in sintered funnel 518 and is filled with deionized water. Typically —0.04 grams of fluid is drained from the system during this process. This process prevents premature absorption of deionized water when the piston / cylinder assembly 520 is positioned within the sintered funnel 518. The amount of fluid that is drained from the sintered funnel in this process (referred to as the correction weight sintered tube, or "Wffc": fritted funnel correction weight) is measured by performing the PUP test (see below) over a 20 minute time period without piston / cylinder assembly 520. Essentially all of the fluid drained from the sintered funnel by this process is very quickly reabsorbed by the funnel when the test is started. Thus, it is necessary to subtract this correction weight from the fluid weights removed from the reservoir during the PUP test (see below).

A round die-cut sample 560 was placed for approximately 1 second in a petri dish containing approximately 1 g of deionized water, and then immediately placed in cylinder 554. Piston 556

487 T3 28 slides into cylinder 554 and sits on top of cleaning pad sample 560. The piston / cylinder assembly 520 was positioned on top of the sintered portion of the funnel 518, the weight 558 was slid onto the piston 556, and the top of the funnel 518 was then covered with the sintered funnel cover 522. After verifying the stability of the balance reading, the test is started by opening valves 528 and 540 so that funnel 518 and reservoir 512 are connected. With auto-initiation, data collection begins immediately, when funnel 518 starts. to reabsorb fluid.

Data is recorded at intervals over a total time period of about 1200 seconds (20 minutes). The absorbent capacity of PUP is determined as follows:

absorbent capacity t1200 (gr / gr) = = [Wr (t = 0) -Wr (t = 1200) -Wffc] / Wds where the absorbent capacity at t1200 is the capacity in gr / gr of the pad after 1200 seconds, Wr_{(t = 0)} is the weight in grams of tank 512 before initiation, Wr_{(t = 1200)} is the weight in grams of the deposit 512 1200 seconds after initiation, Wffc is the correction weight of the sintered funnel and Wds is the dry weight of the cleaning pad sample. The speed of fluid absorbency is also measured during the 1200 second test procedure. From the velocity results, the mean absorbance velocity of the sample pad is obtained during the period t = 0 to t = 1200 seconds.

B. Ejection by crushing

The ability of the cleaning pad to retain fluid when exposed to operating pressures, and therefore to avoid "squashing" of the fluid, is another important parameter for the present invention. The "squash ejection" is measured on a complete cleaning pad by determining the amount of fluid that can be dried from the sample with Whatman filter paper under pressures of 1.5 kPa. Squash expulsion is performed on a sample that has been saturated to its capacity with deionized water by horizontal capillary action (especially, by capillary action from the surface of the pad consisting of the scrubbing layer or in contact with the surface. ). A means of obtaining a saturated sample is described in the Horizontal Gravimetric Capillary Action method of US Patent 5,849,805 (Dyer et al.), Issued December 15, 1998. The fluid-containing sample was placed horizontally in an apparatus. capable of supplying the respective pressures, preferably using an air-filled bag that provides evenly distributed pressure across the surface of the sample. Squeeze ejection values ​​are expressed as the weight of test fluid lost per weight of the huomeric sample.