Cleaning member for improved ink jet head and ink jet device provided with said cleaning member

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to an improved cleaning member for removing deposits adhering to the ejection port surface of an inkjet head that ejects ink for recording and the like, and an inkjet device provided with the cleaning member.

【0002】

The cleaning member is composed of a polyurethane prepolymer using a bifunctional curing agent and further added with a water-repellent imparting substance, and is superior to conventional cleaning members particularly in terms of cleaning durability.

【0003】

[Conventional technology]

According to the inkjet method described in US Pat. No. 4,723,129 and US Pat. No. 4,740,796, high-speed, high-density, high-definition, high-quality recording can be obtained.

【0004】

Further, according to the inkjet method, it is possible to easily achieve color recording and the like, and further, since a recording head can be manufactured by using semiconductor technology, it is possible to achieve compactification of the apparatus.

【0005】

In such an inkjet method, an inkjet head provided with a plurality of ink ejection ports having extremely fine diameters is used.

【0006】

When recording, ink is ejected from those ink ejection ports in response to the input of a predetermined recording signal and adheres to the recording medium.

【0007】

Conventional inkjet heads have a continuous type that continuously ejects ink and selectively adheres the ejected ink to the recording medium, and an on-demand type that intermittently ejects only the ink droplets required for recording. And so on.

【0008】

The on-demand type inkjet head is a full-line type in which a plurality of ejection ports are arranged according to the recording width of the recording medium, and the inkjet head is moved relative to the recording medium for recording. The serial scanning type that is designed to perform the above is typically known.

【0009】

In an inkjet device using such an inkjet head, there are the following problems with respect to the inkjet head. That is, in the case of an inkjet head that ejects particleized ink from an ejection port formed with a fine diameter, dust, dust, paper dust from a recording medium, ink droplets, etc. existing in the recording device, etc. May adhere to the discharge port surface or the vicinity of the discharge port as shown in FIGS. 7 (a) and 7 (b). Due to the influence of these deposits, the flight trajectory of the ink particles discharged from the ejection port may become unstable, or the deposits may dry and solidify to block the ink ejection port, making it impossible to eject.

【0010】

As one of the means for solving this problem, a blade made of an elastic member such as polyether urethane rubber, polyester urethane rubber, hydrogenated nitrile rubber, or silicone rubber is used to rub the discharge port surface to wipe off the deposits. The rubber blade cleaning method is known.

【0011】

By the way, in addition to the inkjet recording apparatus that records in a single color, there is an increasing demand for a full-color inkjet recording apparatus equipped with four inkjet heads that eject inks of four colors such as yellow, magenta, cyan, and black. In recording in which the color tone is changed using four colors of ink in this way, it is necessary to eject a plurality of different inks to one dot, so that ejection accuracy is required more than that of a conventional single-color recording device. ..

【0012】

Therefore, it is necessary to constantly clean the state of the ejection port surface of the recording head that ejects each color and always maintain a stable ink ejection state.

【0013】

As a form of use of the cleaning blade in such a full-color recording device, there are one in which an independent cleaning blade is provided for each recording head and one in which each recording head is cleaned with a common cleaning blade. In particular, from the viewpoint of reducing the occupied area in the recording device and making it compact, a cleaning method of cleaning four recording heads with one cleaning blade is preferable.

【0014】

In such a cleaning method, since the recording head that continuously ejects different inks is cleaned, the inks may be mixed on the blade and color defects of the image may occur. As one of the cleaning methods to solve this problem, by cleaning in order from the recording head that ejects relatively light ink to the recording head that ejects dark ink, the influence of color mixing in the recording head that ejects light ink is affected. A method has been proposed to virtually eliminate it.

【0015】

Further, as another method, a configuration is proposed in which an ink absorber or the like is arranged between the color inkjet heads, one head is cleaned with a cleaning blade, and then the ink adhering to the cleaning blade is wiped off with the ink absorber. When cleaning the next head, the ink of the previously cleaned head is not affected.

【0016】

Hereinafter, the proposed method described later will be briefly described with reference to FIG. The main scanning carriage 2 having the inkjet head 1 moves on the main scanning rail 3. Further, in the non-recording area outside the recording area of the recording device, the cleaning blade 4 is arranged at a position where the inkjet head 1 comes into contact with the ejection port surface 1a. Reference numeral 5 denotes a holder for fixing the cleaning blade 4. As the main scanning carriage 2 moves and scans in the direction of arrow A, the cleaning blade 4 provided in the non-recording area rubs the ejection port surface 1a, and ink droplets, paper dust, dust, etc. adhered to the ejection port surface 1a. Use the edge of the cleaning blade 4 to remove the deposit X from the discharge port surface 1a. Then, the ink adhering to the cleaning blade 4 is removed by the ink absorber 6 provided between the inkjet heads, and the cleaning blade 4 cleans the next inkjet head in a cleaned state. Therefore, all the recording heads that eject different inks can be satisfactorily cleaned by the cleaning blade in a cleaned state without causing color mixing between the recording heads.

【0017】

In this case, the cleaning blade and the head rub against each other by the number of the inkjet heads arranged in one cleaning operation, and the number of times the blade head rubs increases as compared with the conventional case.

【0018】

On the other hand, in the field of inkjet recording, in recent years, from the viewpoints described below, research and development on high-speed recording and research and development to enable extremely large amount of recording with one model by using an interchangeable recording head have been carried out. ..

【0019】

For example, in a high-speed recording device, since the amount of ink ejected per unit time is large, the ink easily adheres to the ejection port surface of the recording head, and the timing of cleaning the recording head is for the purpose of eliminating the harmful effects caused by the ink. It is necessary to shorten the time and perform a lot of cleaning.

【0020】

Further, in a device capable of recording a large amount of data, the recording head is replaced a plurality of times and used for a long period of time, so that the number of times the recording head is cleaned by the blade becomes extremely large.

【0021】

As described above, in various inkjet recording devices, the cleaning operation by the cleaning blade is repeated an extremely large number of times. Furthermore, in the case of performing the above-mentioned color recording, as described in FIG. 1, not only the ejection port surface of the recording head but also the ink absorber provided between the heads is rubbed, so that the number of times the blade is rubbed is increased. It will increase further.

【0022】

Therefore, for the cleaning blades in the future, it is further desired to improve the durability as a characteristic thereof.

【0023】

By the way, as the elastic member for the cleaning blade used in the blade cleaning method, silicone rubber, hydrogenated nitrile rubber, polyester urethane rubber, polyether urethane rubber and the like have been conventionally used, but each has the following problems. ing.

【0024】

Silicone rubber has low wear resistance, and continuous rubbing with the inkjet head and ink absorber may cause wear of the silicone rubber, resulting in insufficient cleaning performed using the edge portion of the blade. That is, the worn cleaning blade may cause ink to slip through from the contact portion with the head ejection port surface, and the adhered matter cannot be sufficiently removed. As a result, the flight trajectory of the ink particles ejected due to residual ink and residual deposits due to poor cleaning becomes unstable, causing image defects (streaks due to twisting and non-ejection), and abrasion powder from the cleaning member on the nozzle of the inkjet head. It may be clogged, hinder ink ejection, and cause image defects (streaks due to non-ejection). In addition, an inorganic filler such as silica in the silicone rubber may damage the vicinity of the ejection port of the inkjet head, destabilizing the flight trajectory of the ink particles and causing an image defect. Furthermore, the oil component in the silicone rubber may cause image defects (shobo printing due to poor foaming may cause streaks) due to alteration of the ink. Furthermore, when a silicone rubber blade is used in an inkjet method in which droplets are ejected from an ejection element using thermal energy for recording, the oil component in the silicone rubber invades the ink ejection port and imparts thermal energy. There is a risk that the heating element of the above will burn due to the oil component, making it impossible to eject ink and causing image defects.

【0025】

Further, the hydride nitrile rubber has low wear resistance like the silicone rubber, and when applied to a color inkjet recording apparatus provided with an ink absorber as described above, it is rubbed against the inkjet head and the ink absorber. Durability such as significant wear of the blade after long-term use, insufficient ink cleaning, leaving ink and deposits near the nozzle, deteriorating ejection accuracy, and causing image defects such as color shift. Is not enough. Furthermore, hydrogenated nitrile rubber contains an oil component in order to lower its rubber hardness, but as in the case where the oil component is silicone rubber, the oil component invades the head and burns the heating element or ink. May change the composition of.

【0026】

Furthermore, since urethane rubbers such as polyester urethane rubber and polyether urethane rubber do not require the addition of inorganic fillers and oil components, there is no damage to the head discharge port surface due to the filler, and there is no adverse effect due to the oil components, and further wear resistance. Since it is relatively excellent in rubber, it is currently widely used as a cleaning blade material for inkjet heads.

【0027】

However, although urethane rubber has excellent wear resistance, when applied to a color inkjet recording device as shown in Fig. 1, the number of cleanings is increased by continuously rubbing with four inkjet heads and ink absorbers. When it increases extremely, as shown in Fig. 4 (b), the material is chipped off at the edge of the blade, causing uneven wear (roughened state). Such uneven wear makes it impossible to sufficiently clean the ink in the cleaning operation, and as shown in Fig. 8 (b), ink leakage 10B occurs from the part where the chipping occurs, and the ink remains in the vicinity of the nozzle. .. As a result, when the ink is ejected, the residual ink in the vicinity of the nozzle may deviate the flight trajectory of the ejected ink, which may cause a so-called twisting defect. Further, when the uneven wear becomes large and the amount of residual ink increases, the ejected ink is drawn into the residual ink, and printing may not be performed, so-called non-ejection may occur. In addition, when uneven wear occurs on the blade edge, the pressing pressure of the blade is concentrated on the edge where it is not chipped off, and the contact area with the ink (meniscus) increases, promoting ink withdrawal from the nozzle. (Fig. 5 (b)).

【0028】

In addition, polyester urethane rubber is prone to hydrolysis due to its structure, and in the case of an inkjet recording device that uses water in the air or water-based ink, the rubber deteriorates due to the water in the ink and loses its elastic force. In some cases, normal contact pressure was not applied to the edges and it could not withstand long-term use.

【0029】

Further, since the urethane rubber has a polar group in its structure, it easily absorbs the water-based ink generally used in the inkjet recording apparatus, and therefore the urethane rubber swells due to the ink when it is in contact with the ink for a long period of time. As a result, the cleaning blade pulls out the ink inside the nozzle with its affinity during cleaning (Fig. 5 (b)), and the ink remains in the vicinity of the nozzle, and the residual ink affects the ink ejection direction and deteriorates the ejection accuracy. It may cause defects, or it may be difficult to remove the ink remaining on the blade surface after cleaning, and it may remain as blade stains, which may cause deterioration of cleaning performance at the next cleaning. In particular, when applied to an inkjet recording device that uses multicolored ink, color shift due to poor ejection accuracy becomes a problem as described above, and at the stage of removing residual ink wiped from the head with a cleaning blade with an ink absorber. If the cleaning blade and the ink have a strong affinity, the ink cannot be sufficiently removed, which may cause color mixing.

【0030】

The problems with various blade materials as described above are not so problematic in the current personal type recording devices in which the number of prints at one time is relatively small and the frequency of use thereof is not so high. In other words, personal type devices generally perform monochromatic recording, and as described above, when the number of sheets recorded at one time is small and cleaning is not frequently performed, the device is not used frequently. Because there are many.

【0031】

However, for full-color type recording devices, high-speed recording devices, and long-term usable devices with interchangeable recording heads as described above, cleaning blades used to restore and improve print quality compared to personal machines. The frequency of use is extremely high, and high reliability or durability is required. In particular, in a full-color recording device, as described above, the cleaning blade is continuously rubbed with, for example, a plurality of recording heads and a plurality of absorbers in one cleaning operation, so that the number of times of rubbing with the heads and the like becomes substantially extremely large. After all, high reliability is required.

【0032】

[Problems to be Solved by the Invention]

Under such circumstances, the present invention aims to provide a material suitable as a cleaning blade of a recording device of a type in which a particularly high-quality image is required or is used for a long period of time. is there.

【0033】

As a result of various studies to improve the above-mentioned problems, the present inventors have added inorganic fillers, oil components, etc., which are particularly likely to affect inks and recording heads, among those listed as various blade materials. We focused on polyurethane rubber-based materials that are unnecessary and have relatively excellent wear resistance. Then, using this material, various experiments such as selection of constituent materials, change of additives, and adjustment were conducted, and the following views were obtained.

【0034】

First, the view on the improvement of the wear resistance of the cleaning blade is given.

【0035】

Generally, as a curing agent for polyurethane rubber, a bifunctional component which is a chain extender and a trifunctional or higher functional component which is a cross-linking agent are used.

【0036】

Since the polyfunctional component connects neighboring molecules by a chemical bond, it plays a role in making it difficult for slips and shifts between neighboring molecules to occur when the rubber is deformed. As a result, it is possible to manufacture a rubber that is hardly permanently deformed and has a small compression set. However, since this polyfunctional component restrains the movement of neighboring molecules, it hinders the interaction (aggregation) between polar groups and the interaction (crystallization) between main chain molecules in urethane rubber. As a result, the strength of rubber (tear strength, tensile strength) is reduced. Especially in the case of polyether urethane, the difference in tensile strength and tear strength depending on the presence or absence of the polyfunctional component is remarkable.

【0037】

According to the studies by the present inventors, it has been clarified that the wear form differs depending on the presence or absence of the polyfunctional component. That is, when a wear was examined by using a polyether urethane rubber produced by blending a rubber having a polyfunctional component in an inkjet recording device as shown in FIG. 9 described later, the discharge port surface of the recording head of the cleaning blade was examined. It was found that the material was partially chipped (chipping) as shown in Fig. 4 (b) at the rubbing part with the rubber, resulting in a non-uniform wear form. On the other hand, as shown in Fig. 4 (a), it was found that the polyurethane rubber produced by the rubber compounding containing only the bifunctional component had no chipping on the rubbing surface of the blade and had a uniform wear form.

【0038】

This difference in wear form becomes a big problem in the cleaning blade for an inkjet recording device. That is, when uneven wear occurs due to chipping as shown in FIG. 4 (b), ink slips through 10B occurs from the chipped portion during the cleaning operation as shown in FIG. 8 (b), and the nozzle Ink may remain in the vicinity, causing printing defects such as twisting and non-elopement. Further, when chipping occurs, the pressing pressure of the blade against the head is concentrated on the edge portion where the chip is not generated, and as a result, ink is drawn out from the nozzle. On the other hand, since polyurethane rubber composed of bifunctional components causes uniform wear, there is no chipping of the blade edge, ink does not slip through, and pressure is applied evenly, so ink withdrawal from the nozzle is minimized. It can be suppressed and good cleaning is done as shown in FIG. 8 (a).

【0039】

Here, the ink withdrawal will be described with reference to FIGS. 2 and 3.

【0040】

The cleaning blade 4 that rubs the ink ejection port surface 1a of the recording head is pressed with an appropriate pressure. Therefore, in the cleaning blade 4 in which the chip is formed as described above, the stress is concentrated on the edge portion in which the chip is not generated, and the edge portion of the cleaning blade 4 is located inside the ink ejection port 1b as shown in FIG. May invade. By the way, in the ink ejection port 1b, the meniscus M is formed by the predetermined surface tension of the ink existing in the ink liquid passage and the negative pressure applied to the ink.

【0041】

When the edge portion where the stress of the blade 4 is concentrated penetrates into the ink ejection port 1b in this way, the edge portion and the meniscus M portion of the ink may come into contact with each other depending on the amount of the penetration. If the blade moves in this state, the ink that has come into contact with the blade will be drawn out of the ejection port 1b (Fig. 5 (b)). Here, the ink pool existing between the cleaning blade 4 and the ink ejection port surface 1a of the recording head indicates the ink scraped by the cleaning operation.

【0042】

On the other hand, the polyether polyurethane-based cleaning blade formed by using only a bifunctional component as a curing agent does not cause chipping and stress concentration, so that the edge portion of the blade is inside the discharge port 1b in the first place. The phenomenon itself of invading is unlikely to occur.

【0043】

Further, even if the edge portion of the blade penetrates into the discharge port, the amount of penetration is extremely small, so that contact with the meniscus M is unlikely to occur. In addition, polyurethane-based cleaning blades that use only a bifunctional hardener show uniform wear. Therefore, even if the cleaning blade is worn as shown by the broken line in FIG. 3, the edge portion of the blade is extremely difficult to penetrate into the discharge port 1b. Further, even if the edge of the worn cleaning blade penetrates into the ejection port, the amount of penetration is extremely small, and contact with the meniscus M of the ink can hardly occur. That is, even if cleaning is performed, it is extremely difficult for ink to be drawn out from the ejection port.

【0044】

On the other hand, the following views were obtained regarding the improvement of water repellency of the cleaning blade.

【0045】

As shown in FIG. 2, the blade 4 invades into the ejection port 1b during the cleaning operation, comes into contact with the meniscus M of the ink formed in the ejection port as the blade moves, and the ink adhering to the blade (ink itself). The amount of ink drawn out varies depending on the surface tension of the blade and the water repellency of the blade), and the phenomenon of drawing the ink out of the ejection port also differs depending on the water repellency of the blade material. Here, FIG. 6 shows the relationship between the contact angle and the adhesion area. As is clear from FIG. 6, the smaller the contact angle θ of the blade material, the larger the ink adhesion area to the blade, and the larger the contact angle θ, the smaller the ink adhesion area. That is, the ink contact angle of the portion where the blade and the ejection port 1b are in contact with each other when the blade 4 finishes passing through the ejection port is related to the amount of ink drawn out, and the lower the water repellency of the blade, the smaller the contact angle, and the blade. Since the amount of ink adhering to the ink increases, the amount of ink drawn out tends to increase. Therefore, under the condition that the ink easily adheres to the blade material, the ink once adhered to the blade at the ejection port portion does not separate from the blade, and the ink is easily drawn out from the ejection port as the blade moves due to cleaning. (Fig. 5 (b)).

【0046】

That is, by giving the cleaning blade water repellency, the contact angle between the ink and the cleaning blade is increased, the adhesion of ink can be reduced, the amount of ink drawn out by cleaning is reduced, and a good cleaning state is achieved. Can be done.

【0047】

[Means for solving problems]

The present invention has been made based on the results of studies made by the present inventors as described above, and is a material in which a bifunctional curing agent is used for a polyurethane prepolymer and a water repellent-imparting substance is added. By forming a blade with ink jet, it is possible to record for a long period of time, and even if cleaning is repeated during that period, there is no uneven wear due to chipping of the cleaning blade, etc., and good cleaning can always be maintained even during long-term use. The present invention is to provide a cleaning blade for an inkjet head that prevents ink from being drawn out from a nozzle portion of the inkjet head.

【0048】

In addition, by further imparting water repellency to the elastic member having excellent wear resistance, ink leakage from the cleaning blade is improved, ink withdrawal from the ejection port is eliminated, and a cleaning blade for an inkjet head that can give a good image. Is to provide. Another object of the present invention is to provide an inkjet recording device using these cleaning blades.

【0049】

Further, the present invention is a cleaning member for removing deposits adhering to the ink ejection surface of an inkjet recording head that ejects ink and records on a recording medium. The cleaning member is made of an ether-based polyurethane rubber elastic body. Moreover, it is a cleaning member for an inkjet head, characterized in that the curing agent component of the ether-based polyurethane rubber elastic body is composed of only a bifunctional component.

【0050】

Further, the present invention is a cleaning member for removing deposits adhering to the ink ejection surface of an inkjet recording head that ejects ink and records on a recording medium. The cleaning member is made of a polyurethane rubber elastic body and is described above. A cleaning member for an inkjet head, characterized in that the curing agent component of the polyurethane rubber elastic body is composed of only a bifunctional component, and further contains a water-repellent imparting substance having an active group capable of chemically bonding with the polyurethane rubber. is there.

【0051】

Further, the present invention is an inkjet device provided with a support member capable of mounting an inkjet head that ejects water-based ink and records on a recording medium, and the support member is used as a recording area on which the recording medium is conveyed. The non-recording area is provided with a means for scanning between the non-recording area outside the area and a cleaning blade capable of cleaning the discharge port surface of the head, and the cleaning blade is ether. This is an inkjet device comprising a polyurethane rubber elastic body and having a curing agent component of the ether polyurethane rubber elastic body composed of only bifunctional components.

【0052】

Furthermore, the present invention is an inkjet device provided with a support member capable of mounting an inkjet head that ejects water-based ink to record on a recording medium, and the recording area in which the recording medium is conveyed to the support member. The non-recording area is provided with a means for scanning between the and the non-recording area outside the area, and the non-recording area is provided with a cleaning blade capable of cleaning the discharge surface of the head. It is said that it is made of a polyurethane rubber elastic body, the curing agent component of the polyurethane rubber elastic body is composed of only a bifunctional component, and further contains a water-repellent imparting substance having an active group capable of chemically bonding with the polyurethane rubber. It is a featured inkjet device.

【0053】

Here, as the urethane raw material preferably used as the material of the cleaning blade of the present invention, ethylene adipate-based, lactone-based polyester-based, polycarbonate-based, polyether-based, or the like can be arbitrarily used. Particularly, considering the hydrolyzability, a polyether urethane is preferable. As a polyether urethane material, the following general formula HO (CH)₂CH₂CH₂CH₂O)_nH It is a polyether urethane raw material obtained by the reaction of polyoxytetramethylene glycol (hereinafter abbreviated as PTMEG) represented by, and polyisocyanate. Commercially available products include Vibrasen B625, B635, B670, B821, and B836 (trade name). , Uniroyal), Adiplen M400, M415, M467, M483, LW520, LW570 (trade name, manufactured by DuPont) and the like. As another raw material for polyether urethane, a general formula HO (CH)₂CH₂CH₂O)_nH A polyether urethane raw material obtained by reacting polyoxypropylene glycol (hereinafter abbreviated as PPG) represented by (hereinafter abbreviated as PPG) with polyisocyanate, and examples of commercially available products include Vibrasen B843 (trade name, manufactured by Uniroyal). However, it is not limited to this.

【0054】

The isocyanate that can be reacted with the above polyol is not particularly limited, and isocyanates conventionally used in polyurethane production can be used. For example, diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, etc. Examples thereof include hydrogenated diphenylmethane diisocyanate.

【0055】

Further, as described above, the curing agent for the polyurethane raw material required for the blade to exhibit uniform wear resistance is required to be a bifunctional curing agent. Examples of the bifunctional curing agent include 4,4-butanediol, 1,6-hexanediol, ethylene glycol, propylene glycol, polyethylene glycol, hydroquinone ethylol ether, bisphenol A, methylenebis orthodichloroaniline, and triethylene glycol. As a curing agent such as paraaminobenzoate and a commercially available curing agent, Vibracure-A120, A931 (trade name, manufactured by Uniroyal Co., Ltd.), MOCA and the like, and mixtures thereof can be used. Among these, linear diols are preferable because they have good hydrolysis resistance and do not inhibit crystallinity. It should be noted that using only the bifunctional curing agent in the present invention does not prevent the polyfunctional curing agent from being contained to the extent of impurities.

【0056】

Also the curing agent of the polyurethane raw material is then not only difunctional curing agent described above can be used also polyfunctional curing agent on condition that the addition of the water repellency-imparting member shown below. For example, as a polyfunctional curing agent, a general urethane curing agent such as trimethylolpropane, trimethylolethane, and glycerin, and as a commercially available curing agent, VibraCure A125, A510, A567, Vibrasen 3080, 3095 (Product name, manufactured by Uniroyal), and mixtures thereof can be mentioned.

【0057】

In addition, as the water-repellent-imparting substance for improving the drawability of the blade used in the present invention with respect to ink, a polyurethane material is used to prevent the water-repellent-imparting substance from bleeding during long-term use and the water repellency from decreasing over time. A water-repellent substance having at least one active group such as a hydroxyl group, an amino group, an epoxy group, or an isocyanate group capable of chemically bonding with is preferable, and when the cleaning blade absorbs ink and becomes swollen. Also, since it must retain its water repellency, it is preferable that a chemical structure having a low surface energy is present in the molecule.

【0058】

Specific examples of the water-repellent-imparting substance include a modified silicone compound and a reactive fluorine compound, and examples of commercially available products include MF100, MF110, MF120, and M130 (manufactured by Mitsubishi Materials Corporation) as reactive fluorine compounds. , Cm alcohol, HFIP (manufactured by Central Glass), PFA6 (manufactured by Neos), etc. Examples of modified silicone compounds include amino-modified silicones such as SF8417 and BY16-828 (manufactured by Toray Dow Corning), SF8411 (manufactured by Toray). Epoxy-modified silicones such as Dow Corning), alcohols such as BX16-005, SF8427, SF8428 (Toray Dow Corning), X-22-160AS (Shinetsu Silicone), DKQ8-779 (Dow Corning) Modified silicone and the like can be mentioned, but the present invention is not limited thereto. Further, when a water-repellent substance having poor solubility in the polyurethane rubber material is used, it exists in the polyurethane rubber in the form of particles. When the water-repellent-imparting substance is present in the form of particles, the water-repellent-imparting effect on the polyurethane rubber is reduced, so that it is necessary to add more water-repellent-imparting substance than necessary, and the physical characteristics of the rubber are deteriorated to some extent. In addition, the particle component may cause uneven wear of the urethane cleaning blade, which is not very suitable for long-term use. Therefore, it is preferable that the water-repellent-imparting substance exists in a state of being compatible with the polyurethane rubber material. Further, when the recording head is an inkjet recording method in which droplets are ejected from an ejection element using thermal energy for recording, the modified silicone compound is not preferable from the viewpoint of foreign matter burning on the heating element. Therefore, the reactive fluorine compound is particularly preferable in consideration of the solubility in the polyurethane rubber material and the risk of foreign matter burning on the heating element.

【0059】

In the present invention, the ink contact angle (backward contact angle) of the blade is preferably 80 degrees or more. It should be noted that the ink contact angle is included in the above-mentioned range in the case where the amount of each component described below is satisfied.

【0060】

In the best embodiment of the present invention, there is a blade material formed by using only a bifunctional curing agent as a curing agent for polyurethane of a cleaning blade and adding a water repellent-imparting substance to the curing agent.

【0061】

A cleaning blade having such a configuration causes uniform wear peculiar to a blade formed of a bifunctional curing agent, and maintains a suitable contact angle with an ink obtained by adding a water-repellent imparting substance. It is possible to reduce the withdrawal of ink during cleaning, and it is possible to achieve good cleaning with uniform pressure for a long period of time without ink slipping.

【0062】

The sum of the number of moles of the bifunctional curing agent and the number of moles of the active element of the water repellent-imparting substance is preferably 0.80 to 1.05 with respect to the number of moles of the isocyanate group contained in the polyurethane of the blade material in the above embodiment, which is more preferable. Is preferably 0.90 to 1.00.

【0063】

Further, it is desirable to use 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, of the water repellent-imparting substance with respect to 100 parts by weight of the total amount of polyurethane and the curing agent. If the amount of the water-repellent substance used is less than 0.1 parts by weight, sufficient water repellency cannot be obtained, causing ink withdrawal, color mixing, etc., and if it is more than 20 parts by weight, the physical properties of the rubber deteriorate and cause significant wear. It is not preferable because it may become.

【0064】

Of course, as a preferred embodiment of the present invention, a blade material composed of polyurethane using only a bifunctional curing agent, or a polyurethane raw material using a bifunctional curing agent, a polyfunctional curing agent, and a water repellent-imparting substance is used. The blade material constructed in the above is also included.

【0065】

It should be noted that the use of only the bifunctional curing agent here does not prevent the polyfunctional curing agent from being contained to the extent of impurities.

【0066】

The amount of the bifunctional curing agent added and the amount of the water repellent-imparting substance added to the two types of blade materials listed as the preferred embodiments are described in the description of the blade material of the example cited as the optimum embodiment. It satisfies the numerical value.

【0067】

In order to manufacture the cleaning blade of the present invention, a predetermined amount of polyurethane and a curing agent that have been heated and melted in advance, and a water-repellent-imparting substance that has been heated as desired are weighed, mixed and stirred, and defoamed if necessary to form a mold. Alternatively, it is cast by casting into a centrifuge or the like and heat-curing at 80 to 140 ° C. Further, the water-repellent-imparting substance may be mixed and reacted with the polyurethane raw material in advance, and then a curing agent may be added, or may be dissolved and dispersed in the curing agent in advance to react with the polyurethane.

【0068】

According to such a method, since the water-repellent imparting substance is contained inside the polyurethane rubber, the water repellency does not decrease even when the surface is worn by rubbing.

【0069】

The hardness of the molded rubber for cleaning blades should be JISA hardness of 40 to 90 degrees, rather than the cleanability of liquid ink.

【0070】

More preferably, it is 50 to 90 degrees.

【0071】

[Example]

Experiment The experiments performed by the present inventors are shown below.

【0072】

Experiment A 22.7 parts by weight of heat-dissolved polyethylene glycol (bifunctional curing agent, molecular weight 1000) and 5.7 parts by weight of 1,4-butanediol (bifunctional curing agent) were mixed, and Nn-propyl-N-2, 3-Dihydroxypropyl perfluorooctylsulfonamide (fluorine-based water repellent-imparting substance, trade name MF110, manufactured by Mitsubishi Materials Co., Ltd.) was added in an amount of 3.6 parts by weight and dissolved by heating and stirring at 90 ° C to prepare a uniform solution.

【0073】

This solution was added to 100 parts by weight of a polyurethane polymer (ether-based urethane PTMEG-MDI, NCO content 7.7 wt%, trade name Vibrasen B635, manufactured by Uniroyal) heated to 80 ° C, and a curing agent for the number of moles of isocyanate groups. The number of moles of the active element of each of the water-repellent-imparting substances (hereinafter referred to as OH / NCO) was 1.00, and the mixture was stirred and mixed, and then defoamed in vacuum to obtain a uniform mixed solution.

【0074】

This mixed solution was cast into a centrifuge molding machine preheated to 130 ° C. and heat-cured for 1 hour. After that, it was demolded and secondarily cured at 130 ° C. for 4 hours to form a transparent sheet material having a thickness of 0.7 mm and containing 3 parts by weight of a water-repellent material for a total amount of 100 parts of a polyurethane raw material and a curing agent.

【0075】

After edge cutting, this sheet material was punched to a size of 10 mm × 15 mm to manufacture a test blade A for each evaluation item described later.

【0076】

Experiment B 23.6 parts by weight of polyethylene glycol, 5.9 parts by weight of 1,4-butanediol, 1.3 parts by weight of Nn-propyl-N-2,3-dihydroxypropyl perfluorooctyl sulfonamide, and other conditions were the same as in Experiment A. A transparent sheet material in which the content of the water-repellent-imparting substance was adjusted to about 1 part by weight was molded and punched under the same conditions as in Experiment A to manufacture a test blade B.

【0077】

Experiment C 21.6 parts by weight of polyethylene glycol, 5.4 parts by weight of 1,4-butanediol, 6.3 parts by weight of Nn-propyl-N-2,3-dihydroxypropyl perfluorooctylsulfonamide, and other conditions were the same as in Experiment A. A transparent sheet material in which the content of the water-repellent imparting substance was adjusted to about 5 parts by weight was molded and punched under the same conditions as in Experiment A to manufacture a test blade C.

【0078】

Experiment D Polyethylene glycol was 24.0 parts by weight, 1,4-butanediol was 6.0 parts by weight, and Nn-propyl-N-2,3-dihydroxypropyl perfluorooctylsulfonamide was 0.2 parts by weight. A transparent sheet material in which the content of the water-imparting substance was adjusted to about 0.2 parts by weight was molded and punched under the same conditions as in Experiment A to manufacture a test blade D.

【0079】

Experiment E 18.6 parts by weight of polyethylene glycol, 4.7 parts by weight of 1,4-butanediol, 13.4 parts by weight of Nn-propyl-N-2,3-dihydroxypropyl perfluorooctyl sulfonamide, and other conditions are the same as in Experiment A. A transparent sheet material in which the content of the water-imparting substance was adjusted to about 10 parts by weight was molded and punched under the same conditions as in Experiment A to manufacture a test blade E.

【0080】

Experiment F 14.1 parts by weight of polyethylene glycol, 3.5 parts by weight of 1,4-butanediol, 23.5 parts by weight of Nn-propyl-N-2,3-dihydroxypropyl perfluorooctyl sulfonamide, and other conditions are the same as in Experiment A, and the repellent properties are the same. A transparent sheet material in which the content of the water-imparting substance was adjusted to about 20 parts by weight was molded and punched under the same conditions as in Experiment A to manufacture a test blade F.

【0081】

Experiment G Polyethylene glycol was 19.3 parts by weight, 1,4-butanediol was 4.8 parts by weight, and Nn-propyl-N-2,3-dihydroxypropyl perfluorooctylsulfonamide was 3.2 parts by weight, and weighed so that OH / NCO was 0.8. The test blade G was manufactured in the same manner as in Experiment A under other conditions.

【0082】

Experiment H Polyethylene glycol was 23.8 parts by weight, 1,4-butanediol was 6.0 parts by weight, and Nn-propyl-N-2,3-dihydroxypropyl perfluorooctylsulfonamide was 3.8 parts by weight, and weighed so that OH / NCO was 1.05. The test blade H was manufactured in the same manner as in Experiment A under other conditions.

【0083】

Experiment I In Experiment A, the water-repellent substance was changed to 3.6 parts by weight of 3- (2-perfluorohexyl) ethoxy-1,2-dihydroxypropane (fluorine-based water-repellent substance, trade name MF100, manufactured by Mitsubishi Materials Corporation). Manufactured test blade I in the same manner as in Experiment A.

【0084】

Experiment J In Experiment A, the water-repellent substance was C₉ F₁₇O- (CH₂ )₆ -The test blade J was manufactured in the same manner as in Experiment A, except that it was changed to 3.6 parts by weight of OH (fluorine-based water repellent substance, trade name PFA6, manufactured by Neos).

【0085】

Experiment K In Experiment A, a test blade K was manufactured in the same manner as in Experiment A, except that the water-repellent-imparting substance was changed to 3.8 parts by weight of alcohol-modified silicone oil (silicone-based water-repellent-imparting substance, manufactured by Toray Dau).

【0086】

Experiment L A test blade L was produced in the same manner as in Experiment A except that polyethylene glycol was 24.3 parts by weight and 1,4-butanediol was 6.1 parts by weight and no water repellent-imparting substance was added.

【0087】

Experiment M The test blade M was used in the same manner as in Experiment A, except that the difunctional curing agent was only 69.8 parts by weight of polyethylene glycol and 3.9 parts by weight of Nn-propyl-N-2,3-dihydroxypropyl perfluorooctyl sulfonamide. Manufactured.

【0088】

Experiment N The test blade N was used in the same manner as in Experiment A, except that the difunctional curing agent was only 34.0 parts by weight of polyethylene glycol and 3.3 parts by weight of Nn-propyl-N-2,3-dihydroxypropyl perfluorooctyl sulfonamide. Manufactured.

【0089】

Experiment O Change the polyurethane polymer to 100 parts by weight of ether-based PPG-MDI (trade name: Vibrasen B843, manufactured by Uniroyal), change the bifunctional curing agent to 2.3 parts by weight of ethylene glycol, and 9.3 parts by weight of 1,6-hexanediol, and change Nn-propyl. A test blade O was produced in the same manner as in Experiment A, except that -N-2,3-dihydroxypropyl perfluorooctylsulfonamide was 2.9 parts by weight.

【0090】

Experiment P Experiments except that the polyurethane polymer was 100 parts by weight of ether-based PTMEG-HMDI (trade name: Adiprene LW520, manufactured by Uniroyal) and 3.5 parts by weight of Nn-propyl-N-2,3-dihydroxypropyl perfluorooctyl sulfonamide. A test blade P was manufactured in the same manner as A.

【0091】

Experiment Q Polyurethane polymer is ester-based EA-MDI (trade name: Coronate C4369, manufactured by Nippon Polyurethane Industry Co., Ltd.) 100 parts by weight, difunctional curing agent is 1,4-butanediol 1.5 parts by weight, 1,6-hexanediol 5.9 parts by weight, repellent The water-imparting substance was changed to Mitsubishi Materials' trade name MF100 3.2 parts by weight, and the test blade Q was manufactured in the same manner as in Experiment A.

【0092】

Experiment R Experiment A except that the polyurethane polymer is 100 parts by weight of the ester-based EA-MDI, the bifunctional curing agent is 1.6 parts by weight of 1,4-butanediol and 6.5 parts by weight of 1,6-hexanediol, and no water-repellent substance is added. The test blade R was manufactured in the same manner as above.

【0093】

Experiment S Polyurethane polymer is ester-based EA-MDI 100 parts by weight, bifunctional curing agent is 1,4-butanediol only 4.0 parts by weight, polyfunctional curing agent trimethylolpropane (trifunctional curing agent) 1.0 part by weight, water repellency imparting substance Was changed to MF100 3.1 by weight, and the test blade S was manufactured in the same manner as in Experiment A.

【0094】

Experiment T The test blade T was the same as in Experiment A, except that the difunctional curing agent was 1,4-butanediol alone at 5.8 parts by weight and the polyfunctional curing agent trimethylolpropane was 1.4 parts by weight, and no water repellent-imparting substance was added. Manufactured.

【0095】

Experiment U Polyurethane polymer is 100 parts by weight of ester-based EA-MDI, difunctional curing agent is 1,4-butanediol only 4.8 parts by weight, trimethylolpropane polyfunctional curing agent is 1.2 parts by weight, and no water-repellent substance is added. Manufactured a test blade U in the same manner as in Experiment A.

【0096】

Experiment V Using the trade name G-655 as hydrogenated nitrile rubber and manufactured by Nippon Oil Seal Co., Ltd., a sheet material with a thickness of 0.7 mm was cut in the same manner as in Experiment A to manufacture a test blade V.

【0097】

Experiment W A sheet with a thickness of 0.7 mm, which is a mixture of 100 parts by weight of the product name SH861V and Toray Dow Corning as a silicone rubber and 2 parts by weight of the product name RC4 and Toray Dow Corning as a curing agent, and press-molded with a mold. The material was molded. This was cut in the same manner as in Experimental Example A to manufacture a test blade W.

【0098】

Each of the test blades A to W manufactured in each of the above experiments A to W was attached to the inkjet recording apparatus shown in FIG. 9, cleaned, and roughened, wear-resistant, and head scratch-resistant. , Ink withdrawability and the obtained image were evaluated.

【0099】

Here, the inkjet recording apparatus used in performing the above-mentioned evaluation will be schematically described.

【0100】

FIG. 9 is an external perspective view showing an example of an inkjet recording device to which a blade is attached.

【0101】

In the figure, 501 is an inkjet head cartridge (IJC) provided with a group of nozzles for ejecting ink facing the recording surface of the recording paper fed onto the platen 507. 502 is a carriage (HC) that holds the IJC501, is connected to a part of the drive belt 504 that transmits the driving force of the drive motor 503, and slides with two guide shafts 505 and 506 arranged parallel to each other. By making it possible, the reciprocating movement by the inkjet head over the entire width of the recording paper becomes possible.

【0102】

The 508 is a head recovery device, which is arranged at one end of the movement path of the IJC501, for example, at a position facing the home position. The head recovery device 508 is operated by the driving force of the motor 510 via the transmission mechanism 509 to cap the IJC501. In connection with the capping of the head recovery device 508 to the IJC 501 by the cap portion 511, ink is sucked by an appropriate suction means provided in the head recovery device 508 or by an appropriate pressurizing means provided in the ink supply path to the IJC 501. Ink pressure feeding is performed, and ink is forcibly discharged from the ejection port to perform ejection recovery processing such as removing thickening ink in the nozzle. In addition, the recording head is protected by performing capping at the end of recording or the like.

【0103】

Reference numeral 512 denotes a cleaning blade of the present invention disposed on the side surface of the head recovery device 508. The blade 512 is held by the blade holding member 513 in the form of a cantilever, and is operated by the motor 510 and the transmission mechanism 509 like the head recovery device 508, and can be engaged with the discharge surface of the IJC 501. As a result, the blade 512 is projected into the movement path of the IJC501 at an appropriate timing in the recording operation of the IJC501 or after the discharge recovery process using the head recovery device 508, and the blade 512 is formed on the discharge surface of the IJC501 as the movement of the IJC501 is performed. Wipe off condensation, wetness or dust.

【0104】

In addition, for each test blade, the rubber hardness, the presence state of the water-repellent substance, the ink contact angle, and the ink deterioration property in JISA were evaluated.

【0105】

The evaluation methods for each of the above evaluation items are outlined below. (1) Rubber hardness: Measured according to the rubber hardness measurement method shown in JIS (Japanese Industrial Standards) A. The results are shown in Table 1. (2) Existence of water-repellent substance: After cutting as each test blade, the cut surface was observed with a microscope. Regarding the obtained results, those in which the presence of the particle component of the water repellent-imparting substance was confirmed were shown as "particles", and those in which the presence of the particle component was not recognized were shown as "compatibility" in Table 1. (3) Ink contact angle: For the manufactured test blades A to W, CI Murd Fuzzo 2 3 wt%, diethylene glycol 25 wt%, N-methyl-2-pyrrolidone. Measurements were carried out with a contact angle meter (trade name CA-Z150, manufactured by Kyowa Interface Science Co., Ltd.) using a water-based ink (hereinafter referred to as the ink used) having a composition of 20 wt% and 52 wt% water. The results are shown in Table 1. In Table 1, the ink contact angle "initial" indicates the measurement result of the unused state after the test blade is manufactured. The ink contact angle "after ink swelling" indicates the measurement result of the state in which the test blade is immersed in the ink used for 10 days. (4) Ink alteration: Each test blade is immersed in the ink used for 3 months, and the components of the immersed ink are measured by gas chromatography (trade name GC-9A, manufactured by Shimadzu Corporation), and the test blade is used. The component changes with the ink before immersion were compared. Here, is the one for which the deterioration state is not confirmed, is the one for which the deterioration state is not substantially confirmed, is the one for which the ink component is changed but does not pose a problem in image formation, and the ink component change. Those that are seen and affect image formation were evaluated as x, and the results are shown in Table 1. (5) Roughening resistance and wear resistance: A test blade was attached to the inkjet recording device shown in Fig. 9 under the conditions of a blade free length of 8 mm and a penetration amount into the head of 1.5 mm. Then, 50 empty discharges are not issued to the cap, and then a predetermined pattern is recorded on the recording paper when the sequence of performing the cleaning operation once is repeated 10 times. This cycle was repeated until the number of cleanings reached 50,000. At this time, the cleaning speed was 150 mm / sec, and the linear pressure on the head surface of the blade was 5 g / cm.

【0106】

Each of the test blades after 50,000 times was observed under a microscope.

【0107】

Regarding the roughening resistance, those that are not roughened without chipping at the edge of the blade are , those that are slightly chipped but do not pose a problem in cleaning are , Table 1 shows the results by evaluating the ones with missing parts that are roughened and have a slight effect on cleaning as , and the ones that have markedly chipped parts and are roughened and have an effect on cleaning as ×. It was shown to.

【0108】

Regarding wear resistance, those with no wear on the edge of the blade are marked with , those with slight wear but not affecting cleaning are marked with , and those with wear are found and slightly worn for cleaning. Those that affect cleaning are evaluated as Δ, and those that significantly wear and affect cleaning are evaluated as ×, and the results are shown in Table 1. (6) Head scratch resistance and ink withdrawal property: The vicinity of the discharge port on the discharge port surface of the recording head was observed with a microscope after the cleaning operation was repeated 50,000 times under the same conditions as described above. Regarding the head scratch resistance, those with no damage to the ejection port surface of the recording head are , those with virtually no damage and no effect on ink ejection are , and damage is observed. However, those that slightly affect ink ejection are evaluated as Δ, and those that are damaged and affect ink ejection are evaluated as ×, and the results are shown in Table 1.

【0109】

Regarding the ink withdrawal property, for those that do not allow ink withdrawal, for those that do not allow ink withdrawal, for those that allow ink withdrawal and have a slight effect on ink ejection, and ink withdrawal. Those that were significantly observed and had an effect on ink ejection were evaluated as x, and the results are shown in Table 1. (7) Image evaluation: A test blade was attached to the inkjet recording device shown in Fig. 9 under the conditions of a free blade length of 8 mm and a penetration amount into the head of 1.5 mm. Then, 50 empty discharges are not issued to the cap, and then a predetermined pattern is recorded on the recording paper when the sequence of performing the cleaning operation once is repeated 10 times. This cycle was repeated, and the recording state of the recording pattern was visually observed when the number of cleanings was 10,000, 50,000, and 100,000, respectively. At this time, the cleaning speed was 150 mm / sec, and the linear pressure on the head surface of the blade was 5 g / cm.

【0110】

A good image was formed , an image with virtually no problem was formed , and an image drool (non-ejection part) was observed at a rate of about 1 in about 1000 records. Those with non-discharged parts were evaluated as Δ, and those with non-discharged parts were evaluated as ×, and the results are shown in Table 1.

【0111】

From the results shown in Table 1, the following was found. That is, (i) a blade material prepared by using only a bifunctional curing agent and adding a water-repellent-imparting substance to a polyurethane prepolymer is good in all of the above-mentioned evaluation items; ( ii) Among these blade materials, the ratio of the number of moles (OH / NCO) of both active elements of the bifunctional curing agent and the water-repellent imparting substance to the number of moles of isocyanate groups contained in the polyurethane prepolymer. Blade materials made with a value of 0.80 to 1.05, more preferably 0.9 to 1.0, give satisfactory results for all of the above endpoints; and (iii) in particular polyurethane prepolymers and 2 The blade material prepared by adding a water-repellent imparting substance of 0.1 or more and 20 parts by weight or less, more preferably 1 or more and 10 parts by weight or less with respect to 100 parts by weight of the total amount of the functional curing agent has all of the above-mentioned evaluation items. Gives very good results.

【0112】

In addition to the facts found above, it was found that the presence state of the water-repellent substance in the blade material is a compatible state, which is an extremely important factor for the performance of the blade material.

【0113】

[table 1]

<img file="JPH05201014A_D0001.tif" />【0114】

[Table 2]

<img file="JPH05201014A_D0002.tif" />【0115】

[Table 3]

<img file="JPH05201014A_D0003.tif" />【0116】

[Table 4]

<img file="JPH05201014A_D0004.tif" />【0117】

Example 1 Hereinafter, examples of the present invention will be described.

【0118】

In this example, the full-color recording shown in FIGS. 10 to 13 is performed using the test blade A which showed an excellent effect as a blade material in the previous experiment and the test blade S which did not obtain a sufficient effect. These blades were attached to an inkjet device capable of cleaning, and a durability test was conducted in which cleaning was repeated 50,000 times.

【0119】

Hereinafter, the outline of the full-color inkjet apparatus shown in FIGS. 10 to 13 and the state of cleaning will be briefly described step by step.

【0120】

In these figures, the head unit 101 is fixed to the carriage 102, and the carriage 102 is attached to the main scanning rail 103 so as to be movable in the printing direction. Then, for example, when the discharge port 101b of the head unit 101 is clogged, the holder 301 having the cap 300 forming a closed space in the head in the non-printing position moves in the direction of the arrow a, and the cap 300 moves to the discharge surface 101a. Contact with and stop at a position where a closed shape can be formed. In this state, suction recovery is performed by the pump unit 303 via the tube 302. The ink drawn from the head unit 101 by suction is carried to the ink discharge processing member 305 via the tube 304. After the suction recovery, the holder 301 holding the cap 300 retracts in the direction of arrow b. At this time, the ink I drawn from the discharge port 101b remains on the discharge surface 101a of the head unit 101 due to the suction recovery. Here, the carriage 102 moves, the cleaning blade 401 held by the blade holder 402 wipes the ejection surface 101a (states of FIGS. 11 and 12), and the ink I on the ejection surface 101a is removed from the ejection surface 101a. Will be done.

【0121】

On the downstream side of the wiping of the head unit 101, one absorber 104 is fixed to the head unit 101 by means such as adhesion or heat caulking. Further, in the configuration on the head side, a tapered portion 101c is formed on the portion of the discharge surface 101a adjacent to the absorber 104 and located on the upstream side of wiping by the absorber 104, and the edge portion of the absorber 104 protrudes. It is configured.

【0122】

Further, a small amount of ink that may remain on the blade 401 is absorbed by the absorber 105 as the second absorbing member provided on the carriage 102 to perform complete cleaning.

【0123】

The materials of the absorbers 104 and 105 are polyolefin-based porous members having a property of hardly swelling at the time of liquid absorption (for example, a polyethylene porous sintered body is hydrophilized and swells. The rate is 0.01 to 0.02%. Product name: Sunfine AQ, manufactured by Asahi Kasei Corporation.

【0124】

Explaining in more detail with reference to FIGS. 11 and 12, the ink I adhering to the ejection surface 101a due to suction recovery is removed from the ejection surface 101a by the blade 401 as the carriage 102 moves, and moves the ejection surface 101a together with the blade 401. Then, in the tapered portion 101c formed on the ejection surface 101a, the ink I is scraped from the blade 401 by abutting on the edge 104a of the absorber 104 of the head, and the ink is once stored in the tapered portion 101c. Immediately after that, the ink I'is absorbed by the absorber 104 (the state of I'in FIG. 11). Then, when the carriage 102 moves further, the blade 401 then rubs against the absorber 105 of the carriage and moves. At this time, the blade 401 moves while absorbing a small amount of ink I that could not be removed by the absorber 104 of the head by the absorber 105, and when arriving at the next head, the ink is ink from the edge portion 401a of the blade 401. Is completely removed (state in Fig. 12). Therefore, the ink removed from the ejection surface 101a does not affect the next head, color mixing and the like are prevented, and the next wiping can be performed with the edge 401a of the blade 401 always in a pure state.

【0125】

The edge state of the test blades A and S after the durability test was observed. As a result, the blade A manufactured using only the bifunctional curing agent and the water-repellent imparting substance was not roughened at all (Fig. 4 (a)), and an extremely good cleaning state could be maintained for a long period of time without wear (Fig. 4 (a)). Fig. 5 (a) and Fig. 7 (a)), there is no deterioration in image quality. On the other hand, in the blade S manufactured by adding a large amount of trifunctional curing agent, the blade material is remarkably chipped off and the surface is roughened (Fig. 4 (b)), the head surface is damaged, the ink is slipped out, or the ink is ink. Due to the withdrawal (Fig. 5 (b)), the cleanability for a long period of time could not be maintained at all, and the image quality deteriorated.

【0126】

[Effect of the invention]

As described above, by using a material prepared by using polyurethane to which no inorganic filler is added as a raw material and adding a bifunctional curing agent and a water-repellent imparting substance, the discharge port surface of the recording head can be used. It does not damage, does not deteriorate with ink, does not easily wear the blade material itself, is extremely durable against roughening such as partial chipping of the material, and maintains water repellency. Since the ink release of the blade is good, it is possible to provide a cleaning blade that exhibits extremely stable cleaning characteristics even in long-term use without causing ink withdrawal.

【0127】

By using the cleaning blade having such characteristics, it is possible to provide an inkjet device capable of high-speed recording or full-color recording capable of recording stable high-quality images for a long period of time with high reliability.

[Simple explanation of drawings]

[Figure 1]

It is explanatory drawing which shows the state of cleaning by the cleaning blade in the inkjet recording apparatus which performs color recording.

[Figure 2]

It is explanatory drawing explaining the state which the edge part of the cleaning blade penetrates into the ejection port of a recording head, and draws out ink.

[Fig. 3]

It is explanatory drawing which shows the state which draws out the ink from the ejection port of a recording head when the edge portion of a cleaning blade wears well.

[Fig. 4]

It is explanatory drawing which shows the blade form after the endurance, (a) shows the blade which was excellent in rough surface resistance, and (b) is the blade which has low rough surface resistance and roughened.

[Fig. 5]

(a) is an explanatory diagram showing a good cleaning state, and (b) is an explanatory diagram showing a state in which ink is withdrawn from the ejection port due to cleaning.

[Fig. 6]

It is a figure which shows the relationship between the contact angle of a blade material, and an ink adhesion area.

[Fig. 7]

(a) and (b) are schematic views showing a state in which deposits such as ink are attached to the ejection port surface, respectively.

[Fig. 8]

(a) is a schematic view showing a state in which good cleaning has been performed, and (b) is a schematic view showing a state in which cleaning has been performed by a roughened blade.

[Fig. 9]

It is an external perspective view which shows an example of the inkjet recording apparatus provided with the cleaning blade to which this invention is applied.

[Fig. 10]

It is the schematic which shows the state of blade cleaning in the inkjet recording apparatus which performs color recording step by step, and shows the initial state.

[Fig. 11]

It is the 2nd schematic diagram which shows the state of blade cleaning in the inkjet recording apparatus which performs color recording step by step, and shows the state which ink is sucked by the absorber of a head.

[Fig. 12]

It is the 3rd schematic diagram which shows the state of blade cleaning in the inkjet recording apparatus which performs color recording step by step, and shows the state which ink is sucked by the absorber of the carriage.

[Fig. 13]

It is the 4th schematic diagram which shows the state of blade cleaning in the inkjet recording apparatus which performs color recording step by step, and is the state which the blade cleaning is completed.

[Explanation of symbols]

1 Inkjet head 1a Discharge port surface 1b Ink ejection port 2 Main scanning carriage 3 Main scanning rail 4 Cleaning blade 5 blade holder 6 Ink absorber