Composition comprising nanoparticle tio2 and ethylene copolymer

(54) Title: COMPOSITION, MOLDED ARTICLE AND CONTAINER (30) Unionist Priority: 31/01/2005 us 11 / 047,406 (73) Holder (s): EI Du Pont de Nemours and Company (72) Inventor (s): Austin Henry Reid Jr, ChristinaTroeltzsch, Douglas E. Spahr, John W. Paul, Mark David Wetzel (74) Attorney (s): Cristiane Araújo Rodrigues (86) International Request: pct us2006003327de3i / 0i / 2006 (87) International Publication: wo 2006 / 0838i5de 10/08/2006 (57) Abstract: composition, molded article and CONTAINER. The present invention relates to a composition that comprises or is produced from TiO₂ nanoparticle size, an ethylene copolymer or jonomer of the ethylene copolymer and, optionally, a second polymer. It also refers to films and other molded articles produced from them. The composition, which has a barrier to UV light, can be used to protect products that may be susceptible to UV such as foodstuffs.

ΡΙ0606342-0 “COMPOSITION, MOLDED ARTICLE AND CONTAINER”

Field of the Invention

The present invention relates to a composition comprising TiO₂ with nanoparticle size (nano-TiO₂) and ethylene copolymer, to its process and to a product produced from it.

Background of the Invention

Ethylene copolymers are also referred to by those skilled in the art as polymers that comprise repeated units derived from ethylene and a polar monomer, such as ethylene acid copolymers, and include their ionomers. They are useful as packaging material. These polymers are well known to those skilled in the art and, because these polymers comprise repeated units derived from polar monomers, they have properties distinct from other polymers that do not have repeated units derived from polar monomers, such as polyethylene, polypropylene and other polyolefins.

It is well known that the presence of fillers in a polymeric resin can improve the mechanical and chemical properties of the resin. While the load can improve the tensile strength or modulus of a resin, this can decrease the toughness of the resin, the break elongation or the flexural modulus. By increasing from the surface area to the volume, such as with nanoparticles, the amount of charge required can be reduced, thereby reducing the negative effect of the charge, while maintaining or increasing the improvement of the desired properties.

Nanoparticles can often access properties that bulky materials cannot, such as which wavelengths are absorbed or transmitted. For example, titanium dioxide is a well-known white pigment (in general, which ranges in size from 100 nm to 1,000 nm) and can absorb and diffuse light in the visible region.

The TiO nano particles₂ (referring to TiO₂ that have particle sizes in the range of about 1 to about 100 nm) can be dispersed in water while remaining transparent in appearance. While the TiO nano₂ it is not absorbing or diffusing light in the visible region, it absorbs in the UV region.

For example, WO 2003/099911 describes the incorporation of TiO nano particles₂ in polyolefins; US 6,667,360 describes the incorporation of TiO particles₂ in polymer resins to improve mechanical properties; and the US document

6,479,576 describes the incorporation of TiO particles₂ in polyethylene or ethylene copolymers.

Many packaging applications have a need for a transparent, UV barrier film. For example, a packaging material that remains transparent attracts consumers. Such packaging material can be used for food, medicine, medical devices and cosmetics. Such a UV barrier film can increase shelf life and reduce other measures to preserve the packaged material.

The plasticized polyvinyl butyral sheet can be used in the manufacture of laminated structures such as, for example: windshields for vehicles including automobiles, motorcycles, boats and airplanes; houses and buildings; office shelves and display cases; and other articles where structural strength is desirable in a sheet of glass. In many applications, it is desirable that the laminate covering is undesirable to UV light and / or is transparent. In addition, a variety of decorative glass laminates can be useful in a variety of applications; the use of decorative glass laminates is not widespread in end-use applications, such as furniture, cabinets, shelves, table tops and the like.

Therefore, there is a continuing need to improve polymer properties, without sacrificing current properties, for packaging, bottles, laminated glass, in particular, transparent ethylene copolymer films that exhibit a barrier to the transmission of ultra-violet light.

Brief Description of the Invention

The present invention includes a composition that comprises, or is produced from, a nano-TiO₂ and a polymer that includes an ethylene copolymer or ionomer of the ethylene copolymer, polyester, polyvinyl butyral or combinations of two or more thereof.

Also included is a process for producing the composition.

Also included is a modeled article produced from the composition.

Detailed Description of the Invention

An ethylene copolymer is a polymer that can comprise repeating units derived from about 5 to about 50%, or about 10 to about 19%, or 12 to 15%, by weight (% by weight) of a polar monomer such as acrylic acid, alkyl acrylic acid, or alkyl acrylate or combinations of two or more thereof, based on the total weight of the ethylene copolymer. The alkyl group can contain up to about 20 carbon atoms such as methyl, ethyl, butyl, isobutyl, pentyl, hexyl and combinations of two or more of the same.

Examples of such polar monomers include acrylic acid, methacrylic acid, ethacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, isopropyl methacrylate butyl, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, octyl acrylate, octyl methacrylate, undecyl acrylate, undecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, dodecyl acrylate, dodecyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl acrylate, isobornyl acrylate, la-acrylate methacrylate, la-acrylate, acrilate hydroxyethyl, 2-hydroxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, poly (ethylene glycol) acrylate, poly (ethylene glycol) methacrylate, methyl poly (ethylene glycol) acrylate, methyl poly (ethylene glycol) ether methacrylate, poly (ethylene glycol) behenyl ether acrylate, poly (ethylene glycol) behenyl ether methacrylate, poly (ethylene glycol) 4-nonylphenyl ether acrylate, ether methacrylate Poly (ethylene glycol) 4-nonylphenyl, poly (ethylene glycol) phenyl ether acrylate, poly (ethylene glycol) phenyl ether methacrylate, dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl fumarate, fumarate of diethyl, dibutyl fumarate, dimethyl fumarate, vinyl acetic acid, vinyl acetate, vinyl propionate and combinations of two or more of them.

An ethylene copolymer can comprise up to 35% by weight of an optional comonomer such as carbon monoxide, sulfur dioxide, acrylonitrile, maleic anhydride, maleic acid diesters, (meth) acrylic acid, maleic acid, maleic acid monoesters, itaconic, fumaric acid, fumaric acid monoester, a salt of these acids, glycidyl acrylate, glycidyl methacrylate, glycidyl vinyl ether and combinations of two or more of the same.

The acidic portion of an ethylene copolymer can be neutralized with a cation to produce an ionomer. Neutralization, for example, can vary in the range of about 0.1 to about 100, or about 10 to about 90, or about 20 to about 80, or about 20 to about 40%, with based on the total content of carboxylic acid, with a metal ion. Metal ions can be monovalent, divalent, trivalent, multivalent or combinations of two or more of them. Examples include Li, Na, K, Ag,

Hg, Cu, Be, Mg, Ca, Sr, Ba, Cd, Sn, Pb, Fe, Co, Zn, Ni, Al, Sc, Hf, Ti, Zr, Ce and combinations of two or more of the same. If the metal ion is multivalent, a complexing agent, such as stearate, oleate, salicylate and phenolate radicals can be included, as described in US 3,404,134.

The ionomer can also be a mixture of an ionomer which has a neutralization greater than 20% and, for example, an ethylene (meth) acrylic acid copolymer to obtain the desired degree of neutralization.

For example, an ethylene alkyl acrylate copolymer can comprise from 1 to 30% by weight of at least one E / X / Y copolymer in which E comprises ethylene; X is a monomer selected from the group consisting of vinyl acetate and alkyl (meth) acrylic esters; and Y is one or more optional comonomers described above; X is 0 to 50% by weight of the E / X / Y copolymer, Y is 0 to 35% by weight of the E / X / Y copolymer, where the weight percentage of X and Y cannot both be zero (0), and E being the remainder.

Examples of ethylene copolymers include, but are not limited to, ethylene / methyl acrylate (EMA), ethylene / ethyl acrylate (EEA), ethyl acrylate (EA), ethylene / butyl acrylate (EBA), ethylene / isobutyl acrylate / methacrylic acid, ethylene / methyl acrylate / maleic anhydride, ethylene / butyl acrylate / glycidyl methacrylate (EBAGMA) and ethylene / butyl acrylate / carbon monoxide (EBACO), and butyl acrylate (BA).

Examples of commercially available ethylene copolymers include those available from EI duPont de Nemours and Company (DuPont), Wilmington, Delaware, under the trademarks Surlyn®, Nucrel®, Appeel®, Bynel® and Elvalov® and Evalva®.

Such ethylene copolymers can be produced by any methods known to those skilled in the art using the autoclave or tubular reactors (for example, US 3,404,134, US 5,028,674, US 6,500,888 and US 6,518,365).

For example, an ethylene copolymer can be produced at high pressure and high temperature in a tubular reactor. The inherent consequences of dissimilar reaction kinetics for the respective ethylene and alkyl (meth) acrylate comonomers (eg methyl acrylate) are moderated or partially offset by the intentional introduction of the monomers along the reaction flow pathway into the reactor tubular. Such ethylene copolymer produced by the tubular reactor has a higher relative degree of heterogeneity along the polymeric main chain (a larger block distribution of the comonomers), reduced branches of the long chain and a higher melting point than those produced at the same ratio. comonomer in a high pressure agitated autoclave reactor. For additional information on ethylene copolymers produced by tubular and autoclave reactors, see Richard T. Chou, Mimi Y. Keating and Lester J. Hughes, High Flexibility EMA made from High Pressure Tubular Process, Annual Technical Conference - Society of Plastics Engineers (2002), 60^The (Vol. 2), 1832-1836. The ethylene copolymers produced by the tubular reactors are commercially available from DuPont. Certain ethylene copolymers available from DuPont have a melt flow (g / 10 minutes) of about 0.1 to about 10 and comprise repeating units derived from an alkyl acrylate of about 5 to about 30% by weight .

Polyester is a polycondensation product of an alcohol and an organic acid or the salt thereof or the ester thereof. The example of polyester and its production has been described widely as, for example, in US patents 6,166,170; US 6,075,115; US 6,080,834; and US 6,255,442. Because polyester is well known to those skilled in the art, the description of which is omitted here for reasons of brevity.

Polyvinyl butyral (PVB) may be commercially available, for example, from DuPont or Solutia, St. Louis, MO. PVB can also be manufactured according to any method known to those skilled in the art as described in US patent 3,153,009. The PVB resin can be prepared by mixing polyvinyl alcohol (PVA) with butyraldehyde in an aqueous medium in the presence of an acid or mixture of acids, at about 5 ° C to 100 ° C. The ratio of PVA and butyraldehyde may depend on the functionality of the residual hydroxyl such as, for example, from about 10 to about 50, or from about 15 to about 25, or from about 15 to about 20, or from about 17 to about 19, percentage by weight of PVA in the total mixture. The percentage in residual weight of PVA can be determined according to ASTM D1396-92.

Nano-TiO2 can be present in the composition between about 0.1 to about 50, or about 0.5 to about 30, or about 0.5 to about 10, or about 0.5 to 2 % by weight (based on the total weight of the composition).

The nano-TiO₂ it may have an average size distribution of less than or equal to about 125 nm, or <100 nm, or <50 nm, or <40 nm, or <20 nm. The nano-TiO₂ it is preferably coated with an acid, a silicone compound, another metal oxide or combinations of two or more thereof. The coating can be in the range of about 0.1 to about 25% by weight, or from 0.1 to about 10% by weight, or from 0.3 to about 5% by weight, or from 0, 7 to about 2% by weight.

The acid can be a carboxylic acid such as, for example, adipic acid, terephthalic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, salicylic acid and ester or salt thereof.

Examples of silicone compound can be a silicate or organic siloxane silane including silicate organoalcoxisilano, aminosilane, epoxisilano and mercaptosilane such as hexiltrimetoxisilano, octiltrietoxisilano, noniltrietoxisilano, deciltrietoxisilano, dodeciltrietoxisilano, trideciltrietoxisilano, tetradeciltrietoxisilano, pentadeciltrietoxisilano, hexadeciltrietoxisilano, heptadeciltrietoxisilano, octadeciltrietoxisilano, N- (2-aminoethyl) 3-aminopropylmethyl dimethoxysilane, N- (28 aminoethyl) 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 3-mercaptopropyl trimethoxysilane and combinations of two or more of the same.

Examples of metal oxides include AI₂O₃, SiO₂, ZrO₂ or combinations of two or more of the same.

The composition may also include plasticizers, optical brighteners, adhesion promoters, stabilizers (for example, hydrolytic stabilizers, radiation stabilizers, thermal stabilizers and ultraviolet (UV) light stabilizers), antioxidants, ultraviolet ray absorbers, anti-oxidants. static, colorants, dyes or pigments, dazzles, fillers, flame retardants, lubricants, reinforcing agents (eg flakes and glass fibers), processing aids, anti-slip agents, sliding agent (for example, talc, anti-blocking agents), and other additives.

The nano-TiO₂ it may be commercially available or produced by any means known to the person skilled in the art such as that described in US patent 6,667,360. Phosphoric acid, metal phosphate, metal halide, metal carbonate, metal sulfate or combinations of two or more of them can be used to control the crystallinity, amorphous content, or grinding ability of nano-Ti0₂. The metal can be sodium, potassium, aluminum, tin or zinc. The surface reactivity of the particles can also be controlled by coating with a surface agent such as metal oxide, an acid, or silane as described above.

The composition comprising an ethylene copolymer can be produced using any methods known to those skilled in the art. A copolymer of ethylene and nano-TiO₂ they can be dry mixed, dry stirred, dry melted and other methods known to the person skilled in the art. For example, the incorporation of nano-TiO₂ in an ethylene or polyvinyl butyral copolymer it can be accompanied using both powder and syrups. A syrup or dry powder of TiO₂ it can be in an ethylene copolymer in an autoclave reactor containing the copolymer. The copolymer can be a base resin or a desired ionomer. The introduction can be done with a Roll Mill or an extruder, and with a color concentrate in the desired material or in direct compositions. Alternatively, a roll grinder can be used to produce a color concentrate in an extruder with a percentage by weight of nano-TiO₂ between 10 to 30, followed by extrusion between 0.5 to 2% by weight while neutralizing about 10 to about 90% with metal ions based on the total content of carboxylic acid. Alternatively, a nano-TiO powder₂ can be added to a desired ionomer in an extruder by a color concentrate with a weight percentage of nano-TiO₂ between 10 and 30 followed by extrusion between 0.5 to 2% by weight.

The composition can also comprise a plasticizer. Plasticizers can be those known to the person skilled in the art. For example, the plasticizer used in the production of plasticized PVB sheets can include triethylene glycol di- (2-ethylexanoate), tetraethylene glycol diheptanoate, dibutyl sebacate or combinations of two or more thereof.

The plasticizer can be included in any amount, such as about 5 to about 50 parts per hundred (pph) of resin, or about 20 to about 45 pph, or about 32 to about 45 pph, based on total dry weight of resin. Plastification can be carried out using any known processes as described in US 3,153,009 or US 5,886,075.

The composition can also comprise a charge such as CaCO3, SiO₂, THERE₂C> 3, TiO₂ of regular particle size, ZrO₂ or combinations of two or more of the same. A charge can be present in the composition in the range of about 0.01 to about 5% by weight.

A surfactant can also be included in the composition, especially in a PVB composition. Any known surfactant can be used, for example, sodium lauryl sulfate, sodium dioctyl sulfosuccinate, sodium cocomethyl tauride or benzenesulfonic decyl (sulfophenoxy) disodium salt.

A molded article can be produced from the composition. The molded article can be in the form of films, sheets, filaments, strips, molded products, thermoformed products, containers and the like. The processes for producing these products are well known to those skilled in the art. For example, films can be produced by any methods known to those skilled in the art such as, for example, extrusion of molten casting film from the solution, extrusion of blown film and formation of thermoplastic film (e.g. calendering or drawing). Due to the fact that such methods are known to those skilled in the art, their description will be omitted for the sake of brevity.

The films can also be multilayer films produced by co-extrusion or laminations. For example, a multilayer polymeric film may involve two or more layers including an outer overuse or structural layer, an inner barrier layer and an inner layer in contact and compatible with the intended contents of the package and capable of forming the seal necessary to close the product to be placed in the packaging. A film containing nano-TiO2 can also be laminated adhesive to a film or layer made of, or coextruded with materials such as nylon, polypropylene, polyethylene, ionomer, another ethylene copolymer, polyamide, polyethylene terephthalate, polystyrene and / or polyethylene vinyl alcohol. For example, a multilayer film can comprise the nano-TiC> 2 composition as a bonding layer (adhesive or sealant) with polyethylene as the outermost layer.

Films can be used to make a container, which is a molded article for use in packaging and includes box, wallets, bottles, trays, glasses and other containers. Containers can be used for drinks, food (for example, meat, cheese, fish, poultry, nuts and other edible items), spices, condiments, personal care products, fragrance, electronic component, medical device, medicinal liquid, products pharmaceuticals, cosmetics or combinations of two or more of them.

A glass laminate can comprise at least a piece of glass adhered to a film or interlayer layer produced from a composition comprising PVB and nano-TiO2. A glass laminate can optionally include other interlayer materials such as those which are known and used conventionally as interlayers in transparent laminates. A laminated glass can be any combination of laminated glass (glass / glass), glass / plastic, plastic / plastic or other multilayers. Other combinations of glass or plastic, or glass and plastic, can include metals, wood or stone. An adhesive layer can be used. Such glass laminate can be very useful, such as the production of decorative items in annuals, cabinet doors, table top, tablecloth, countertops, entry doors, door panel, shower stall doors, tile, lining ceilings, tiles, stair floor, tile frame, door accessories, equipment lining, room dividers, bookcases and cabinets. Such a glass laminate can be produced, for example, by depositing a sheet of glass and another sheet of glass or plastic sheet or film together, under heat and pressure to form the laminate, or by co-extruding the PVB with a filler. and a plasticizer. The extrusion can be carried out at a temperature of about 175 ° C to about 245 ° C. The extruded sheet can be cooled sharply, or cooled to below about 40 ° C and above about 10 ° C.

The following examples are provided to further exemplify, but are not to be misinterpreted as limiting the scope of the present invention.

Examples

Example 1

The example was prepared by adding nano-TiO powder₂ in a twin screw extruder. The nano-TiO₂ was obtained by Sachtleben Chemie Gmbh, Duisburg, Germany, had an average crystallite size of about 15 nm and was coated with AI₂O₃ and stearic acid. A color concentrate of

10% by weight of TiO₂ in 15% by weight of methacrylic acid / ethylene ionomer having 58% of carboxylic acid groups was produced, then reduced (diluted) to 0.5, 1 and 2% by weight of the samples by stirring with more ionomers. The samples were collected as pellets and then blown into the film. The film mist (ASTM-D 1003 method) and UV absorbance were measured (Table 1). The fog was measured by a Gardner Hazemeter Model UX10 and is defined in the ASTM Standard as n-diffusing light on the shiny surface of a specimen responsible for the apparent reduction in contrast to the objects seen by the reflection of the surface.

Table 1

<td>% in TiO₂</td><td>% in absorbance below 350 nm</td><td>Mist</td>

<td> 0</td><td> 0</td><td> 1,6</td>

<td> 0,5</td><td> 45</td><td> 12,6</td>

<td> 1</td><td> 80</td><td> 38,5</td>

<td> 2</td><td> 100</td><td> 33,0</td>

Example 2

The example was prepared by adding 10% by weight of nanoTiO₂ to 15% by weight of methacrylic acid / ethylene copolymer as a color concentrate. The color concentrate was then treated with ZnO to neutralize 58% of carboxylic acid groups and to reduce by 0.5 to 1% by weight samples with more ionomers as in Example 1. The samples were then blown onto the films and mist of the film was measured as described in Example 1. The results are shown in Table 2.

Table 2

<td>Uncle₂ (%)</td><td> 0</td><td> 0,5</td><td> 1</td>

<td>Mist</td><td> 2,4</td><td> 11,3</td><td> 17,5</td>

Example 3

The material in this example was prepared by direct injection of a nano-TiO syrup₂ in an autoclave reactor, a high pressure pilot unit, during a polymerization process to produce ethylene methacrylic acid copolymer that contained nano-TiO₂. The polymer produced containing nano-TiO₂ was treated as a color concentrate and diluted from 0.5 to 1% by weight (nano-TiO₂) of samples with ethylene methacrylic acid copolymer that did not contain nano-TiO₂.

Table 3

<td>Uncle₂ (%)</td><td> 0</td><td> 0,5</td><td> 1</td>

<td>Mist</td><td> 1,9</td><td> 7,5</td><td> 11,8</td>