KR20020067208A - Ink holding material for ink-jet printer and printing paper comprising the ink holding material - Google Patents

Abstract

PURPOSE: An ink acceptor and printing paper including the same is provided to achieve a superior water resistance, while allowing ink to be quickly absorbed. CONSTITUTION: An ink acceptor contains 20 to 80 weight parts of hydrophobic resin as a binder, 80 to 20 weight parts of hydrophilic resin for permitting ink to be quickly absorbed, and 1 to 10 weight parts of polycarbodiimide resin as a crosslinking agent. A printing paper includes an ink-absorbent layer formed onto a base film, into the thickness of 10 to 15 micron when dried. An acrylic resin is mainly used as the hydrophobic resin for improving an adhesive force which permits the ink-absorbent layer to be tightly adhered to the base film, when the ink-absorbent layer is formed by depositing the ink acceptor onto the base film.

Description

Ink holding material for ink-jet printer and printing paper comprising the same {Ink holding material for ink-jet printer and printing paper comprising the ink holding material}

The present invention relates to an ink receptor for an inkjet printer and a printing paper comprising the same.

More specifically, the present invention forms an ink absorbing layer by applying an ink receptor on a substrate, thereby forming a recording sheet for an inkjet printer, that is, a transparent film or an opaque film based on a plastic film. Or a paper-based photo paper, and the like, comprising: a binder for enhancing adhesion to a substrate, a hydrophobic resin such as acrylic resin, and a hydrophilic resin for enhancing ink absorption and a polycarbodiimide resin as a crosslinking agent. It relates to an ink receptor and a printing paper comprising the same.

Inkjet printers have excellent color expression, high output speed, and low price, and are used in a variety of applications from office to industrial and commercial use. Recently, digital cameras capable of expressing high resolution of 1440dpi have been used. As it is widespread, it is becoming common in home use.

Generally, when printing an image through an inkjet printer, a considerable amount of ink is discharged through the inkjet printer. If the ejected ink solvent is not rapidly absorbed by the printing paper, the printed surface is contaminated after printing and is difficult to handle. There is a problem that becomes difficult.

The ink ejected from an inkjet printer may be classified into a dye ink, which contains a large amount of a high boiling point solvent such as glycerin or ethylene glycol, and a large amount of water, and also uses a pigment to improve the weather resistance of a printed matter. Ink and the like are used.

As a technique related to such a printing paper for inkjet printers, Japanese Patent Application Laid-Open No. 1996-258403 discloses an inkjet transparent in which water absorbency of ink is imparted by mixing and coating polyvinyl alcohol, polyvinylpyrrolidone, and cationic resin on a substrate. The film is described. U.S. Patent No. 5,275,867 describes a technique of applying alumina sol to a substrate using polyvinyl alcohol as a binder to increase solvent absorption and to form a coating film having excellent water resistance. In addition, US Pat. Nos. 5,208,092, 5,389,723 and the like describe an ink absorbing layer that improves water resistance by using a polyfunctional aziridine-based crosslinking agent by mixing a hydrophilic resin and a hydrophobic resin on a base film, and has a high ink absorption rate. However, the multifunctional aziridine-based crosslinking agent has a high temperature reactivity of 130 ° C. or higher, and there is a problem of yellowing with time due to the generation of secondary amines after the reaction.

An object of the present invention is to provide an ink receptor comprising a hydrophobic resin as a binder and a hydrophilic resin for quick absorption of ink and a polycarbodiimide resin as a crosslinking agent.

Another object of the present invention is to provide an ink absorbing layer on a substrate such that the ink receptor comprising a hydrophobic resin as a binder and a hydrophilic resin for fast absorption of ink and a polycarbodiimide resin as a crosslinking agent has a dry thickness of 10 to 15 microns. It is to provide a printing paper for an inkjet printer formed by forming.

The ink receptor for an ink jet printer according to the present invention is a polycarbodiimide resin 1 to 20 parts by weight of a hydrophobic resin such as acrylic resin as a binder, and 80 to 20 parts by weight of a hydrophilic resin for enhancing the absorption of ink. It is made by crosslinking to 10 parts by weight.

The printing paper containing the ink receptor for an inkjet printer according to the present invention is 20 to 80 parts by weight of a hydrophobic resin such as acrylic resin as a binder, 80 to 20 parts by weight of a hydrophilic resin for enhancing the absorption of ink, and 0.1 to 5 organic or inorganic fillers. An ink receptor formed by crosslinking 1 to 10 parts by weight of a polycarbodiimide resin as a crosslinking agent by weight of 100 to 200 parts by weight of a lower alcohol having 1 to 4 carbon atoms as a crosslinking agent is applied on a substrate film with a dry thickness of 10 to 15 microns or more. Is done.

Hereinafter, the present invention will be described in detail with reference to specific examples.

The ink receptor for an ink jet printer according to the present invention comprises a polycarbodiimide resin 1 to 20 to 80 parts by weight of a hydrophobic resin such as an acrylic resin as a binder, and a resin mixture of 80 to 20 parts by weight of a hydrophilic resin for improving absorption of ink. It is characterized by consisting of 10 parts by weight of crosslinking.

The hydrophobic resin is a component that can enhance the adhesive force so that the ink absorbing layer adheres closely to the substrate when the ink receptor according to the present invention is applied to the substrate to form an ink absorbing layer, and an acrylic resin having excellent mechanical properties is mainly used.

The acrylic resins include alpha, beta unsaturated alkyl acrylates and methacrylates, ie methyl acrylate and methyl methacrylate, ethyl acrylate and ethyl methacrylate, hydroxymethyl acrylate and hydroxy methyl methacrylate, hydrates. Hydroxy ethyl acrylate and hydroxy ethyl methacrylate, hydroxy propyl acrylate and hydroxy propyl methacrylate, methacrylamide, butylamino ethyl acrylate and methacrylate, diamino acrylate and methacrylate, acrylamide And copolymers of carboxylic acid monomers such as methacrylamide, methacrylic acid, acrylic acid, maleic acid, and the like. In addition, it is also possible to use a resin in which carboxyl groups of copolymers of carboxylic acid monomers are crosslinked with methacrylic acid, acrylic acid, maleic acid, or the like.

In particular, the hydrophobic resin is preferably one of acrylate and methacrylate containing a hydroxy group such as hydroxymethyl acrylate and hydroxy methyl methacrylate, hydroxy ethyl acrylate and hydroxy ethyl methacrylate. An acrylic resin that is polymerized by necessarily including one of monomers containing at least one carboxyl group such as acrylic acid or maleic acid is used.

As the hydrophilic resin, polyvinylpyrrolidone having excellent hygroscopicity and its copolymer, polyvinyl alcohol and its copolymer, cellulose derivative, starch, gelatin or a mixture of two or more thereof are used.

The polycarbodiimide resin used as the crosslinking agent is represented by the following formula (1).

Wherein R ₁ and R ₃ are alkyl or monoalkyl, capped alkylene oxide polymers having 1 to 10 carbon atoms, preferably 3 to 6 carbon atoms, and R ₂ is representative of known isocyanate moieties, hexamethylene, Cyclohexylene, isophorone, 2,2,4 or 2,4,4-trimethylhexylene, para or meta-tetramethylxylene, dicycloheximethane (dicyclohexymethane) etc. are mentioned.

By using the polycarbodiimide resin, the crosslinking property of the diimide compound may be represented by the following Chemical Formula 2.

When the crosslinking is carried out in the same manner as above, the acid groups contained in the resin produced by copolymerizing the acrylic resin are first crosslinked to form N-acyl urea, and the ester groups are reacted with the hydroxyl groups in the secondary copolymerized resin to form ester urea. It is possible to form a good coating film having good adhesive strength with excellent film strength and excellent water resistance.

When cross-linked as described above, the hydrophobic resin is formed into a network structure, and the hydrophilic resin is contained in the formed network structure to improve the hydrophilicity of the coating film, while improving the absorbency and absorption speed of the ink, and easily eliminating the stickiness after printing. It is possible to improve the water resistance, which is a characteristic of the present invention. In particular, the polycarbodiimide resin used as the crosslinking agent in the present invention is hydrophilic after the reaction, and even after the reaction is completed, since the amine group does not remain, the yellowing phenomenon of the printed material due to the crosslinking agent may be prevented.

The polycarbodiimide resin reacts well with carboxyl groups, amine groups, hydroxyl groups, mercaptans, epoxies, and isocyanate groups and is widely used in film coating or paint, and is stable to ultraviolet rays after the reaction. In the present invention, the polycarbodiimide resin which can be reacted with a crosslinking agent has two or more carbodiimide groups, and the aliphatic polycarbodiimide resin is faster than the aromatic polycarbodiimide resin and has no discoloration. More advantageous. The aliphatic polycarbodiimide resin is represented by Chemical Formula 1, wherein the substituents R ₁ and R ₂ bonded to the nitrogen atoms are aliphatic hydrocarbon groups.

When the ink receptor having water resistance is formed using the polycarbodiimide resin as a crosslinking agent, the acrylic resin is crosslinked with a polycarbodiimide resin to crosslink the acrylic resin, which is a hydrophobic resin, into a network structure. In the hydrophobic resin having the network structure, a carboxyl group or a hydroxyl group should be copolymerized individually or simultaneously, and particularly, 5 to 30 parts by weight of a hydroxyl group-containing acrylic or methacrylate such as hydroxymethyl methacrylate and hydroxyethyl acrylate, acrylic acid It is preferable to use a resin in which carboxylic acids such as methacrylic acid and the like are copolymerized in the range of 40 to 60 parts by weight of alpha and beta-unsaturated fatty acid esters, such as 5 to 30 parts by weight, acrylate and methacrylate. In addition, in order to incorporate the hydrophilic resin into the network structure of the hydrophobic resin in order to absorb the solvent in the ink while adhering the adhesion with the base film and to fix the dye, the hydrophilic resin is 50 to 600 parts by weight based on 100 parts by weight of the hydrophobic resin. Can be included. At this time, when the hydrophilic resin is less than 50 parts by weight with respect to 100 parts by weight of hydrophobic resin, the hydrophobicity is too large, but the water resistance is increased, but the ink absorption speed is slowed, the absorption power is also lowered, there is a problem that it is difficult to expect the action as the ink absorption layer. On the contrary, the ink absorption speed is increased when it exceeds 600 parts by weight. The absorption power is also increased, but the water resistance is too low, there may be a problem that the retention of the printed matter is lowered. In addition, when the amount of the polycarbodiimide resin used as the crosslinking agent is less than 1 part by weight, the crosslinking effect may not be sufficient, resulting in a decrease in water resistance and long stickiness after printing. If so, there may be a problem that the crosslinking degree is too high and the ink absorption rate and absorbency are lowered.

The ink receptor according to the present invention prepared as described above may be used as a printing paper by applying a dry thickness of 10 to 15 microns or more on the base film, and the ink receptor coated on the base film may be referred to as an ink absorbing layer. .

As the base film, a polyester film having excellent heat resistance, weather resistance, dimensional stability and the like is suitable, and a corona treated biaxially stretched polyethylene terephthalate film can be used. In addition, it is also possible to use an o-pack film or paper such as white paper, art paper, matte paper, and the present invention is not limited to the type of these base films, and it is easily understood by those skilled in the art that it is applicable to all commercially available film-like materials. It can be.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described.

The following examples are intended to illustrate the invention and should not be understood as limiting the scope of the invention.

Example 1

55 parts by weight of the acrylic resin of the composition shown in Table 1 (a) and 11 parts by weight of polyvinylpyrrolidone (ISP, product name; PVP K-90), polycarbodiimide resin (product of Union Carbide, product name) UCARLNK.RTM.XL-29SE) 3 parts by weight, 0.5 parts by weight of porous silica (Mizusawa Corporation, trade name mizukasil 78D) and 140 parts by weight of ethanol were added to adjust the total solids to 13% and mixed for 1 hour The receptor was prepared. The ink receptor thus obtained was applied to a thickness of 10 μm with a roll coater commercialized on one surface of the transparent polyester film, and dried at 120 ° C. for 3 minutes to obtain an inkjet transparent film.

Example 2

55 parts by weight of the acrylic resin of the composition shown in Table 1 (a) and 5.5 parts by weight of polyvinylpyrrolidone (ISP, trade name; PVP K-90), quaternized vinylpyrrolidone dimethylaminoethylmethacryl 5.5 parts by weight of late copolymer resin (ISP, trade name 734N), 3 parts by weight of polycarbodiimide resin (product of Union Carbide, trade name; UCARLNK.RTM.XL-29SE), 0.5 parts by weight of multi-process silica (Mizusawa Co., Ltd.) Except for using the product, trade name mizukasil 78D) and 170 parts by weight of ethanol was carried out in the same manner as in Example 1 to obtain an inkjet transparent film.

Example 3

55 parts by weight of the acrylic resin of the composition shown in Table 1 (b) and 11 parts by weight of polyvinylpyrrolidone (ISP, trade name; PVP K-90), polycarbodiimide resin (product of Union Carbide, UCARLNK.RTM.XL-29SE) 3 parts by weight, 0.5 parts by weight of porous silica (Mizusawa Corporation, trade name mizukasil 78D) and 140 parts by weight of ethanol was carried out in the same manner as in Example 1 for inkjet A transparent film was obtained.

Example 4

55 parts by weight of acryl resin and 11 parts by weight of polyvinylpyrrolidone (ISP, trade name; PVP K-90) and polycarbodiimide resin (manufactured by Union Carbide) UCARLNK.RTM.XL-29SE) 3 parts by weight, 0.5 parts by weight of porous silica (Mizusawa Corporation, trade name mizukasil 78D) and 140 parts by weight of ethanol was carried out in the same manner as in Example 1 for inkjet A transparent film was obtained.

Example 5

55 parts by weight of the acrylic resin of the composition shown in Table 1 (D), 11 parts by weight of polyvinylpyrrolidone (ISP, trade name; PVP K-90), polycarbodiimide resin (trade name of Union Carbide; UCARLNK.RTM.XL-29SE) 3 parts by weight, 0.5 parts by weight of porous silica (Mizusawa Corporation, trade name mizukasil 78D) and 140 parts by weight of ethanol was carried out in the same manner as in Example 1 to be transparent for inkjet A film was obtained.

Example 6

55 parts by weight of the acrylic resin of the composition shown in Table 1 (e) and 11 parts by weight of polyvinylpyrrolidone (ISP, trade name; PVP K-90), polycarbodiimide resin (product of Union Carbide, UCARLNK.RTM.XL-29SE) 3 parts by weight, 0.5 parts by weight of porous silica (Mizusawa Corporation, trade name mizukasil 78D) and 140 parts by weight of ethanol was carried out in the same manner as in Example 1 for inkjet A transparent film was obtained.

Comparative Example 1

55 parts by weight of acryl resin and 11 parts by weight of polyvinylpyrrolidone (ISP, trade name; PVP K-90) and 0.5 parts by weight of porous silica (products of Mizusawa Corporation, product name) Except for using mizukasil 78D) and 140 parts by weight of ethanol was carried out in the same manner as in Example 1 to obtain an inkjet transparent film.

Comparative Example 2

55 parts by weight of the acrylic resin of the composition shown in Table 1 (e) and 11 parts by weight of polyvinylpyrrolidone (ISP, trade name; PVP K-90), polycarbodiimide resin (product of Union Carbide, UCARLNK.RTM.XL-29SE) 3 parts by weight, 0.5 parts by weight of porous silica (Mizusawa Corporation, trade name mizukasil 78D) and 140 parts by weight of ethanol was carried out in the same manner as in Example 1 for inkjet A transparent film was obtained.

Experimental Example

The inkjet films obtained in the above Examples and Comparative Examples were printed using a Hewlett-Packard Company Deskjet 890, and the following items were examined.

Water resistance was 3 minutes after printing, water was dropped on the printed surface and rubbed vertically to observe whether the coating film was damaged. When there was no phenomenon that the color of the printed material was not melted by water while the coating film was not damaged at all,?

The ink absorption speed after printing is completed, the ink on the printing surface adheres to A4 paper for copy paper so that the ink on the printing surface does not get on the copy paper. It was set as.

The time when the stickiness disappeared after 3 minutes after printing was overlaid with A4 paper for copy paper on the printing surface, and it was examined whether part of A4 paper for copy paper adhered to the print door of the film after l hour.

Color development was visually examined for consistency with the color on the monitor by the mode specified on the printer.

After printing, after printing, the printout was exposed for 24 hours using a xenon weather-ometer (manufactured by Atlas, product name; S3000 model) and placed on a white paper, and yellowing was visually observed. When yellowing does not occur, (circle) and yellowing occurs as x.

The experimental results are summarized in Table 2 below.

As shown in Table 2, the embodiments according to the present invention are almost all excellent in all aspects of physical properties desirable as printing paper, such as water resistance, ink absorption rate, stickiness, color development and yellowing compared to the comparative examples, some Was found to exhibit the same degree of physical properties.

According to the present invention, when the carboxylic acid and the hydroxyl group are present at the same time when the acrylic resin is polymerized, the crosslinking reaction of the polycarbodiimide resin, which is used as a crosslinking agent, first reacts with the carboxylic acid. In addition, since the hydrophilic resin is contained in the network structure, the absorbed ink is not eluted by the water, and thus, the printout printed by the inkjet printer can be touched within a few minutes to prevent contamination by fingerprints.

However, even when the same resin was used, the comparative examples showed that when the amount of polycarbodiimide was out of the use range or there was no carboxylic acid in the resin, the ink absorption rate was slowed or water resistance was not expressed.

Therefore, according to the present invention, the polycarbodiimide resin is used as a crosslinking agent, and the ink is formed by using a liquid obtained by mixing an acrylic resin and a hydrophilic resin containing a hydroxyl group and a carboxyl group on one side of a polyethylene terephthalate transparent or opaque base film. An inkjet transparent film having an ink absorbing layer using a receptor does not have a problem of yellowing, has excellent water resistance, and has an effect of providing inkjet printing paper capable of continuous output due to high ink absorption speed. This is applied as a base film by applying not only a transparent polyester film but also an opaque polyester film, a processing special paper, etc., and thus the application to high gloss photo paper is possible.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (4)

An inkjet comprising 20 to 80 parts by weight of a hydrophobic resin such as an acrylic resin as a binder and 80 to 20 parts by weight of a hydrophilic resin for enhancing the absorption of ink, by crosslinking with 1 to 10 parts by weight of a polycarbodiimide resin as a crosslinking agent. Ink receptor for printer. The method of claim 1, The hydrophobic resins are alpha, beta unsaturated alkyl acrylates and methacrylates, ie methyl acrylate and methyl methacrylate, ethyl acrylate and ethyl methacrylate, hydroxymethyl acrylate and hydroxy methyl methacrylate, hydroxy Ethyl acrylate and hydroxy ethyl methacrylate, hydroxy propyl acrylate and hydroxy propyl methacrylate, methacrylamide, butylamino ethyl acrylate and methacrylate, diamino acrylate and methacrylate, acryl amide and An ink receptor for an inkjet printer, characterized in that it is selected from the group consisting of copolymers of carboxylic acid monomers such as methacrylamide, acrylic acid, methacrylic acid, or mixtures of two or more thereof. The method of claim 2, The hydrophobic resin is one of acrylates and methacrylates containing hydroxy groups such as hydroxymethyl acrylate and hydroxy methyl methacrylate, hydroxy ethyl acrylate and hydroxy ethyl methacrylate, acrylic acid and methacrylic acid, and the like. The ink receptor for the inkjet printer, characterized in that the acrylic resin is polymerized by including at least one of monomers containing at least one carboxyl group. The printing paper containing the ink receptor for inkjet printer is a binder, 20 to 80 parts by weight of hydrophobic resin such as acrylic resin, 80 to 20 parts by weight of hydrophilic resin for enhancing the absorption of ink, 0.1 to 5 parts by weight of organic or inorganic filler, carbon number It is made by applying an ink receptor formed by crosslinking 1 to 4 parts by weight of a lower alcohol of 1 to 4 with 100 to 200 parts by weight of a raw material mixture to 1 to 10 parts by weight of a polycarbodiimide resin on a base film with a dry thickness of 10 to 15 microns or more. Printing paper containing an ink receptor for an inkjet printer.