JPH07242057A - Material to be recorded for ink jet recording excellent in transparency and gloss - Google Patents

Abstract

PURPOSE:To provide a material to be recorded for ink jet recording forming a high-grade image excellent in ink absorbability and having high gloss, high transparency and excellent water resistance. CONSTITUTION:A material to be recorded for ink jet recording is obtained by providing an ink absorbing layer containing a water-soluble polymer having a quaternary ammonium base on a support and applying a coating soln. containing fine silica particles and 10-150% by wt. of the fine silica particles of a polymer insoluble in both of water and alcohol to the upper surface of the ink absorbing layer in such a coating ratio that the polymer is present within a range not exceeding 0.3g/m<2> and the fine silica particles are present within a range of 5-50% of the total surface area of the ink absorbing layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium for water-based ink using an ink jet recording system, and more particularly to a recording material for ink jet recording having paper, resin coated paper, film or the like as a support. Is.

[0002]

2. Description of the Related Art In recent years, with the increase in speed of ink jet recording apparatuses, the higher definition of recorded images, and the realization of full color, the quality requirements for recording materials have become more and more strict.
Furthermore, among various ink jet printers that have been developed for full-color recording, models that have the capability of outputting high-definition images that are comparable in image quality to color images produced by conventional silver halide photography have been developed. It is desired to develop a recording material having a high gloss equivalent to that of a silver salt color paper. Alternatively, there is an urgent need for a recording material having high transparency and good image quality as an OHP film.

Basic requirements for ink jet recording materials include high ink dot density, bright and vivid color tone, and large ink absorption capacity and high absorption speed, resulting in overlapping ink dots. Also in this case, it is necessary that ink does not flow out or bleed, and that the shape of ink dots is smooth and the periphery is not blurred. Especially in the case of color recording, usually four colors of ink are used and each color ink is ejected as an ink dot on the recording material in an extremely short time, resulting in insufficient absorption capacity and absorption speed of the recording material for the ink. In such a case, the ink overflows on the surface of the recording material, and a phenomenon occurs in which an image is formed in a form in which the inks are mixed nonuniformly, which becomes a problem.

As conventional recording materials for ink jet, for example, JP-A Nos. 55-51583, 56-157, 57-107879, 57-107880 and 5 are available.
9-230787, 62-160277, 62
184879, 62-183382, 64-
A recording material obtained by coating a paper-containing surface with a silicon-containing pigment such as silica found in JP 11877 together with an aqueous binder has been proposed. The fine pigment particles such as silica used in these examples are oil-absorbing materials. Recording materials with large amounts generally reach a certain level in terms of ink absorption capacity and absorption speed, but it is necessary to introduce a large amount of inorganic pigment such as silica into the coating layer. Therefore, there are drawbacks that the surface gloss of the recording material itself is lowered and the vividness of the color tone required in the case of color recording is lost. Further, such a coating layer itself has low translucency, and when a similar coating layer is provided on a transparent film, there is a problem that it becomes an opaque recording material that cannot be used for OHP. If colloidal silica is used instead of silica for the purpose of improving gloss and transparency, the method described in Japanese Patent Laid-Open No.
As described in the text of Japanese Patent Publication No. 157-157, it is not preferable because the ink absorbency is deteriorated. Alternatively, JP-A-3-215082, JP-A-4-67986, and JP-A-5-32
A method for forming a recording material having transparency by coating fine alumina sol with a water-soluble binder on the surface of a support as described in JP-A-037, etc., the alumina sol in the coating layer is described. (Pseudo-boehmite)
There is a problem that the ink absorbency is poor unless the ratio to the binder is increased, and such a coating layer having a high pigment ratio is very likely to cause cracking of the coating film during coating and drying, and the coating amount is 20 g / m2. If it is not about m ² , the ink absorption capacity is not sufficient, and therefore thick film coating is required, which makes it more difficult to control the drying conditions in actual production. In addition, the coating film strength is weak and there are problems that images are easily peeled off by rubbing the surface where ink jet recording is performed, and various problems that curling easily occurs after printing and transparency is still insufficient. Is.

In order to form a translucent ink absorbing layer which is highly transparent and can be used as an OHP sheet, the above-mentioned various inorganic pigments are not used or the amount thereof is limited to a small amount even if they are used. As a result, the ink absorbency must rely exclusively on the binder used. Examples of binders conventionally used for such applications include, for example, polyvinylpyrrolidone, polyvinylpyrrolidone-vinyl acetate copolymers described in JP-A-57-38185 and JP-A-62-184879, and JP-A-60. -1686
No. 51, No. 60-171143, No. 61-13429.
No. 0, No. 0,085, a binder containing polyvinyl alcohol as a main component, or JP-A-62-22038.
Acrylic polymer having a carboxyl group as disclosed in JP-A-3-2,382, and polyvinyl acetal polymer as disclosed in JP-A-4-214382 and JP-A-4-2822.
No. 82, No. 4-285650, various ink-absorbing polymers such as cross-linkable acrylic polymers have been proposed. However, any of these has both ink-absorbing property and water resistance of the coating film itself. Is difficult to
There is a problem that the recorded image is easily washed off when washed with water. Furthermore, in color image recording, the ink absorption capacity and absorption speed are still insufficient, and non-uniform mixing of each color ink occurs on the surface of the recording medium, resulting in remarkable density unevenness particularly when a solid image is recorded. There was a problem to do.

When it is difficult to impart the ink absorption speed and the ink absorption capacity to a single recording layer, the two functions of the two layers are separated as the ink permeable layer and the ink receiving layer, respectively, with the functions of the both being separated. For example, Japanese Patent Laid-Open No. 62-14
No. 0878, No. 62-152779, No. 62-222.
No. 885, No. 62-222886, No. 64-5527.
No. 6, No. 64-55277, No. 2-55185, etc., the addition of an inorganic pigment or the like is limited in any layer in order to ensure translucency and surface gloss. Therefore, even in such a case, the ink absorbency of the binder itself becomes a problem.

[0007]

In any of the above examples, when a large number of ink dots are printed on the surface of a recording material at high speed, as in the case of high speed color recording, the ink absorption speed is high. No recording material was found that satisfied both of the ink absorption capacity and the ink absorption capacity and had excellent surface gloss and translucency. The problem to be solved by the present invention is to provide a recording material having high gloss and excellent transparency, and further shows excellent print quality even in multicolor color recording and water resistance of a recorded image. The purpose is to increase

[0008]

The above object can be achieved by the present invention described below. That is, paper, resin-coated paper (paper whose surface is coated with polyethylene such as photographic base paper),
An ink absorption layer containing a water-soluble polymer having a quaternary ammonium salt group is provided on a support such as a film, and silica fine particles are provided on the upper surface of the ink absorption layer, and 10% or more by weight of the silica fine particles is used. % Or less of a coating solution containing a polymer soluble in both water and alcohol within a range in which the polymer does not exceed 0.3 g / m ² and the silica fine particles are 5% or more of the total surface area of the ink absorbing layer. By forming a recording material for an ink jet, which is applied so as to have a coverage of 50% or less, a recording material having excellent ink absorbability and printing quality can be obtained. To be

The above-mentioned water-soluble polymer having a quaternary ammonium salt group is basically highly water-soluble and has the ability to absorb ink and retain it inside. However, it is usually used as an acid dye or a direct dye as a dye in the ink. Since a dye having a sulfonic acid group in the molecule is used in the molecule, a bond may be formed between the quaternary ammonium salt group and the quaternary ammonium salt in the form of ammonium sulfonate, and the dye may be bonded to the water-soluble polymer to be insolubilized. It is a feature. For this reason, the printed image has good water resistance, but conventionally, such quaternary salt type polymers are not used alone as dye fixing agents,
It has been used as an additive together with pigments and the like. In the present invention, such a polymer having a dye fixing action may be conventionally used in combination with other polymers, but rather, a polymer having a quaternary ammonium salt group as a dye fixing agent is mainly used for ink absorption. It has been found that the use as a binder is very preferable because the dye fixing action can be further increased. That is, when ink droplets land on such a polymer surface, the dye in the ink reacts with the quaternary ammonium base almost instantaneously and is fixed on the polymer. Even when the ink is driven in, the dyes of the respective colors are quickly fixed, so that there is an advantage that the resolution of the recorded image is high. This fixing effect has been well known in the past, but since water-soluble polymers having a quaternary ammonium salt group absorb moisture in the air and become sticky, other polymers and inorganic pigments such as silica are used in combination. It was necessary to prevent stickiness or blocking. Under the present circumstances, the problems that the original ink fixing action is weakened and the gloss and transparency of the film are impaired have not been solved. In order to prevent blocking, it is actively improved by introducing inorganic pigment such as silica or fine particles of organic polymer directly into such an ink absorption layer to give appropriate unevenness to the surface, but the surface gloss and transparency are impaired. In order to introduce such a so-called matting agent to the extent that it does not exist, the introduction amount must be kept at a low level. In such a case, the surface of the matting agent itself is usually covered with the binder polymer. When a polymer having a high hygroscopic property such as a salt type was used as a main binder, it was extremely difficult to prevent blocking by such a method.

In the present invention, when such a quaternary salt type polymer which is extremely likely to cause blocking is used as a binder component for absorbing ink, silica fine particles as a matting agent are directly introduced into a layer containing this polymer. However, it was found that by blocking silica particles on the upper surface of this layer separately from this layer, blocking can be prevented very effectively.

As a further important effect, by introducing silica fine particles into the surface by such a method, the wettability of the surface of the ink absorbing layer with ink is dramatically improved, and a plurality of ink dots land adjacently on the surface. Even in this case, the ink droplets are evenly bonded to each other, and a preferable effect of providing a uniform image density without density distribution is exhibited. That is, when the wettability with respect to the ink on the surface on which the ink lands is poor, the ink dots do not spread appropriately and a part independent of the part where the ink dots are joined to each other is formed, resulting in uneven density and stickiness. The problem arises. Therefore,
By reducing the contact angle of the surface to the ink, and especially when ink dots are ejected adjacent to each other on the surface, it is possible to show high color density without density distribution by actively causing the ink dots to fuse. preferable.

Such silica fine particles are randomly present on the surface of the recording material, and when the size of the silica fine particles is 1 micron or more, good blocking is achieved only when the silica fine particles are present in a proportion of 1% or more of the total surface area. When it occupies 5% or more, the contact angle with respect to the ink is lowered to eliminate the image density distribution and give a uniform solid image. At this time, the respective silica fine particles are most effective in that they are separated from each other without being aggregated, or that island-like portions of silica particles of 100 microns or less are randomly distributed on the surface. When the silica fine particles are densely gathered in a state of about 100 μm or more, it is not preferable because the surface gloss is not significantly reduced and the effect of decreasing the contact angle to the ink is not exhibited on the surface where the silica fine particles are not present. Further, when the silica fine particles occupy 50% or more of the total surface area of the surface of the recording material, there is a problem that surface gloss is significantly reduced and transparency is also significantly reduced although the contact angle is reduced to improve stickiness. In order to achieve the high gloss of the present invention,
In order to obtain a highly transparent recording material, it is preferable that such silica fine particles have a surface coverage of 5% or more and 50% or less of the total surface area, and further, a surface coverage of 5% or more and 25% or less is high while preventing stickiness. This is a very preferable range for securing gloss and high transparency. Furthermore, in the case where the surface coverage of fine silica particles is 18% or less, the decrease in gloss due to silica on the surface can maintain the gloss to the extent that it is hardly visible to the naked eye, which is particularly preferable. In addition, the coverage of silica on the surface is 1.5 × from the average particle diameter and the numerical value of the coating amount.
It is easily calculated by the formula of (coating amount) / (particle radius). For example, the coverage when silica particles having an average particle diameter of 3 microns are coated with a coating amount of 0.3 g / m ² is It is about 10%.

The present invention provides a recording material having a form in which fine silica particles are dispersed on the surface, but the purpose of using fine silica particles is generally extremely easy to disperse and good dispersion stability. The merit is that even when a liquid containing such fine particles is applied and dried, the particles are applied to the surface in an independent form and are unlikely to form an aggregated form. If the silica fine particles are aggregated and, in a remarkable case, a fine particle layer is formed on the surface, the ink absorbability in this part is high, but the ink penetrates into the gaps between the silica fine particles due to the capillary phenomenon, and the dots spread too much. It is not preferable because the resolution is lowered or the dot shape becomes non-uniform and the image quality is deteriorated.
Therefore, it is extremely important that the silica fine particles do not form a continuous layer, and even if several 100 particles or less are gathered together, the size of this portion should be 100 μm or less. The silica fine particles are discretely or sea-island-distributed on the surface because it is necessary or otherwise causes the problem of unevenness in the image.
It is extremely important that the surface of the lower ink absorbing layer is exposed to at least 50% of the entire surface.

The silica fine particles used in the present invention can be sprayed alone on the surface of the recording material to achieve the purpose of preventing blocking and improving stickiness, but the adhesion to the surface is weak, so it is easy to rub the surface. In addition, since the silica fine particles fall off, permanent blocking is not prevented and stickiness is not improved, and when the surface is touched with a finger, a feeling of discomfort such as powderyness is felt, which is not preferable. Therefore, it is preferable to add the soluble polymer to both the fine particles of silica and water and alcohol as an adhesive agent for the fine particles. That is,
In addition to water, alcohols such as glycerin and ethylene glycol are usually added to water-based inks used in ink jet recording devices for well-known reasons. Also, it is required to exhibit good affinity or absorbability. The presence of a polymer having an affinity for both water and alcohol in the ink on the surface on which the ink droplets land helps the ink droplets to be absorbed into the recording material more quickly, and It is extremely preferable since the distribution of droplets is appropriately controlled and the concentration distributions in the solid and image areas are made uniform.

On the other hand, since various compositions of ink are used for the water-based ink used in the commercial ink jet recording apparatus, the optimum polymer is selected according to each ink composition. The effect of the present invention is commonly observed for water-based inks containing water and alcohols.

The water-soluble and alcohol-soluble polymer used for this purpose is not particularly limited, but the fine particles are added to the surface of the recording material by adding them in a weight ratio of 10% to 150% with respect to the silica fine particles. Since the fine particles do not fall off the surface even after being fixed and rubbed, a polymer soluble in various water and alcohol can be used. In this case, if it is less than 10% by weight with respect to the fine particles, the effect as an adhesive is not obtained and the particles are easily dropped off, which is not preferable.
On the contrary, if it is used in a proportion of more than 150% by weight, a layer of such a polymer is formed around the particles and the ink absorbability and the ink fixing property in this portion are impaired, which is not preferable. Further, for the same reason, it is necessary to use such an adhesive polymer in an amount that does not exceed 0.3 g per square meter, and if the coating amount exceeds this amount, a layer of such a polymer is apt to be formed on the surface and ink fixing and absorption are caused. Is unfavorable because it inhibits the image and adversely affects the image.

As the polymer for adhering the silica fine particles to the surface of the recording material, various water-soluble and alcohol-soluble polymers are preferably used as described above. These polymers are water and alcohol in the ink. Since it has an affinity for both, it does not repel ink and contributes favorably to the improvement of image quality. As such a polymer, a polymer selected from polyvinylpyrrolidone and its copolymer, hydroxyethyl cellulose, hydroxypropyl cellulose, chitosan, polyacrylic acid and its copolymer, polyisopropylacrylamide and its copolymer, etc. are preferably used. . When an oil-soluble polymer or the like having a high hydrophobicity is used as a polymer other than the above-mentioned ones, it may be unfavorable because the water-based ink may repel and image unevenness may occur. When such a polymer is applied in an amount of more than 0.3 g on a square meter, a part of the dye in the ink is absorbed by the polymer regardless of the kind of the polymer, and the dye fixing property may be deteriorated, which is not preferable. Furthermore, the best results are obtained in the range of 0.1 g or less of square meters.

As the fine silica particles, those having an average particle size of 1 micron or more and 5 microns or less are preferably used.
If the average particle size is less than 1 micron, the effect of giving unevenness to the surface is small and the blocking effect itself is small. Therefore, in order to prevent blocking, 50% of the surface area is used.
Since it is sometimes applied at a ratio exceeding 1.0, gloss and transparency are deteriorated, which is not preferable. Also, when fine particles having an average particle size of more than 5 microns are used, the surface roughness becomes noticeable and it may also affect the resolution of the image, so the amount used is limited to a very small amount, and in some cases The surface area (coverage) may be less than 1%, and the blocking prevention effect may be insufficient. Therefore, it is preferable that at least 50% or more of the entire particle size distribution of the fine particles to be used is within the range of 1 to 5 microns, and if a large number of particles with a small particle size of less than 1 micron are mixed, the blocking prevention property is deteriorated. In some cases, the gloss and the transparency may deteriorate, and when a large number of particles having a large particle size exceeding 5 microns are mixed, the surface may be roughened or the resolution may be adversely affected.

The fine silica particles used in the present invention slightly absorb the dye in the ink, but the amount of silica itself present on the surface is very small, and the above water-soluble polymer plays a role of holding such fine particles on the surface. However, since the amount of the dye used is extremely small, the amount of the dye absorbed in this portion is also extremely small, so that the image and the dye fixing property are not adversely affected.

The object of the present invention can be achieved by providing an overcoat on the surface of the recording material with the above-mentioned composition of silica and a polymer soluble in both water and alcohol. For the purpose of, it is possible to add other components to further improve the characteristics. For example, various colloidal silica, alumina sol, polymer latex, various metal salts, it is possible to improve the characteristics by surface overcoating by addition of metal oxides, etc., but the amount of these additives is less than this amount relative to the silica particles. Is preferable, and when the amount is more than the amount of silica particles, undesired effects such as deterioration of gloss and transparency may occur, which is not preferable.

If the silica fine particles dispersed as described above are used to prevent blocking and improve stickiness, an ink absorbing and fixing layer containing a water-soluble polymer having a quaternary ammonium salt group is provided thereunder, so that the purpose of the present invention is basically. The polymer having such a quaternary ammonium salt group is, for example,
Alternatively, it is preferably a water-soluble polymer obtained by using at least a monomer selected from Chemical formula 3.

In the chemical formula ¹ , R ¹ represents hydrogen or a methyl group, and Q represents an oxygen or NH group. R ² , R ³ and R ⁴ represent a methyl group or an ethyl group and may be the same or different. X is a halogen ion or a sulfonate anion, an alkylsulfonate anion, an acetate anion,
Represents an alkylcarboxylic acid anion. n represents an integer of 2 or 3. In Chemical formula 2, R ⁵ , R ⁶ and R ⁷ represent a methyl or ethyl group and may be the same or different. X is the same as X in Chemical formula 1. In Chemical formula 3, R ⁸ , R ⁹ and R ¹⁰ represent a methyl, ethyl or allyl group and may be the same or different. X is the same as X in Chemical formula 1.

Preferred compounds among the monomers represented by Chemical Formula 1 are, for example, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth). ) Acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide and N , N-Diethylaminopropyl (meth) acrylamide methyl chloride, ethyl chloride, methyl bromide, ethyl bromide, methyl iodide or a quaternary compound of ethyl iodide, or a sulfone substituted with anion thereof. Salts, alkyl sulfonates, can be exemplified acetates or alkyl carboxylates. Among these, particularly preferable compounds include, for example,
Trimethyl-2- (methacryloyloxy) ethylammonium chloride, triethyl-2- (methacryloyloxy) ethylammonium chloride, trimethyl-2- (acryloyloxy) ethylammonium chloride, triethyl-2- (acryloyloxy) ethylammonium chloride, trimethyl- Three
-(Methacryloyloxy) propylammonium chloride, triethyl-3- (methacryloyloxy)
Propyl ammonium chloride, trimethyl-2-
(Methacryloylamino) ethylammonium chloride, triethyl-2- (methacryloylamino) ethylammonium chloride, trimethyl-2- (acryloylamino) ethylammonium chloride, triethyl-2- (acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloyl) Amino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) propylammonium chloride, triethyl-
3- (acryloylamino) propylammonium chloride, N, N-dimethyl-N-ethyl-2- (methacryloyloxy) ethylammonium chloride,
N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium chloride, N, N-dimethyl-N-ethyl-3- (acryloylamino) propylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium Bromide, trimethyl-3- (acryloylamino) propylammonium bromide, trimethyl-2- (methacryloyloxy) ethylammonium sulfonate,
Examples thereof include trimethyl-3- (acryloylamino) propylammonium acetate.

A preferred example of the monomer represented by Chemical formula 2 is trimethyl-p-vinylbenzylammonium.
Chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium chloride, N, N-dimethyl-N-
Ethyl-p-vinylbenzylammonium chloride, N, N-diethyl-N-methyl-p-vinylbenzylammonium chloride, trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-
Vinylbenzyl ammonium bromide, trimethyl-p-vinylbenzyl ammonium sulfonate, trimethyl-m-vinyl benzyl ammonium sulfonate, trimethyl-p-vinyl benzyl ammonium
Examples thereof include acetate and trimethyl-m-vinylbenzylammonium acetate.

Preferred examples of the monomer represented by Chemical formula 3 include diallyldimethylammonium chloride, diallyldiethylammonium chloride, diallyldimethylammonium bromide, diallyldimethylammonium sulfonate and diallyldimethylammonium acetate.

By introducing the quaternary ammonium salt group represented by the above Chemical Formula 1, Chemical Formula 2 or Chemical Formula 3 into the water-soluble polymer, when it is contained in the ink absorbing layer, it exhibits an excellent dye fixing action and is preferably used. Can be done. Such a quaternary salt type polymer may be used in the form of forming an ink absorbing layer in combination with other pigments such as silica or other water-soluble polymers, but in the case where pigments are used in combination, transparency and gloss are not impaired. Limited to small additions. Also, when other water-soluble polymers are used in combination, the concentration of the quaternary salt type polymer in the layer may decrease and the dye fixing function may not be fully exerted. More preferred is a system that does not.

Further, as the above quaternary salt type polymer, those in which the monomer unit shown in Chemical formula 1, Chemical formula 2 or Chemical formula 3 is contained in the polymer within the range of 10 to 50 parts by weight are particularly preferable, and the content of this range is included. The dye fixability and the ink absorbency are most preferably exhibited by the ratio, and in the range other than this, there is a problem that the dye fixability is deteriorated, the stickiness of the film may be extremely deteriorated, or the water resistance of the film itself may be inferior. May not be. Furthermore, in addition to the monomer units selected from Chemical formulas 1 to 3,
Copolymerization in the range of 30 parts by weight is very preferable because the properties such as the gloss of the film, the adhesion to the support and the curl prevention can be further enhanced.

In formula 4, R ¹¹ represents hydrogen or a methyl group,
R ¹² and R ¹³ represent a methyl group or an ethyl group, and may be the same or different. Q represents oxygen or an NH group. n represents an integer of 2 or 3. Preferred examples of the monomer represented by Chemical formula 4 include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropylacrylamide and the like.

In addition to these monomer units, acrylamide, methacrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, diacetone acrylamide, N-methylol acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth). By copolymerizing a monomer selected from acrylate and N-vinylpyrrolidone in the range of 20 to 80 parts by weight, the ink absorption capacity and the ink absorption speed of the polymer having the quaternary ammonium salt group are increased, and the ink dot diameter is further increased. It gives extremely favorable properties such as adjusting to an appropriate size and eliminating uneven printing on solid parts.
When the amount of such a monomer unit used in the quaternary salt type polymer is less than 20 parts by weight, it is difficult to recognize such a preferable effect, and when it exceeds 80 parts by weight, the concentration of the quaternary base in the polymer is lowered and the ink fixing property is lowered. Function may deteriorate.

As the quaternary salt type polymer, various copolymerizable monomers can be introduced in addition to the above monomer units, but they should be used within a range that does not impair the preferable effects due to the introduction of each monomer unit. It is usually preferably 30 parts by weight or less. Examples of such a monomer include styrene and its derivatives, acrylic acid ester, methacrylic acid ester, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, allylamine, diallylamine and vinyl ethers.

In particular, the above quaternary salt type polymer is extremely preferable because it forms an ink absorbing layer substantially solely and such a polymer itself simultaneously satisfies the ink absorbing property and the ink fixing property. It is preferable to keep the amount to the minimum even when the addition of an inorganic pigment such as silica and the use of other polymers are not necessary or required, and it is usually 10% or less with respect to the quaternary salt type polymer. It is preferable because the gloss and transparency are not impaired. In order to obtain a recording material with particularly high glossiness, it is necessary to configure the surface gloss of the ink absorbing layer itself to a high level, and the glossiness measured at an angle of 60 degrees is at least as measured by the JIS standard glossiness measurement method. By exhibiting a value of 30 or more, a recording material having a glossy feeling can be obtained. Furthermore, when the glossiness of the ink absorbing layer itself is 70 or more, the glossiness is further enhanced, and even if the silica fine particles are sprinkled on the ink absorbing layer together with the adhesive polymer as described above, the glossiness is not significantly reduced. It is extremely preferable because it is not recognized. That is, the presence of silica fine particles on the surface inevitably reduces the glossiness to some extent, but if the surface gloss of the recording material is about 20 or more, the glossiness can be visually confirmed, and thus the surface gloss of such recording material can be confirmed. It is necessary to secure the surface gloss of the ink absorbing layer itself to a value of at least 30 or more in order to keep the value of at least 20. In this case, even if the silica fine particles are sprinkled on the surface for the first time, the surface gloss is a value of 20 or more. It is possible to keep As described above, in order to maintain the surface gloss of the ink absorbing layer itself at 30 or more, it is preferable not to introduce inorganic particles such as silica into the ink absorbing layer as much as possible in addition to the quaternary salt type polymer. Also, in the case of 10 parts by weight or less based on 100 parts by weight of the quaternary salt type polymer, it is extremely preferable in order to maintain the surface gloss at the above preferable level and to provide transparency.

However, it is extremely preferable to add a curing agent to crosslink the quaternary salt type polymer to further improve the water resistance, while improving the ink absorption capacity. As a curing agent used for such a purpose, Epoxy curing agents represented by Chemical formulas 5 to 13 are preferably used. The addition ratio of the epoxy curing agent to the quaternary salt type polymer is preferably in the range of 1 to 30 parts by weight with respect to the polymer. Below this range, crosslinking is insufficient and the effect is not recognized. Addition in excess of parts by weight is not preferred because the curing will proceed too much to form a highly crosslinked polymer and the ink absorption will be extremely reduced. The preferred amount of epoxy hardener is Polymer 1
It is in the range of 1 to 10 parts by weight with respect to 00 parts by weight.

[0033]

[Chemical 5]

[0034]

[Chemical 6]

[0035]

[Chemical 7]

(In the chemical formula 7, n represents an integer of 2 or 3.)

[0037]

[Chemical 8]

[0038]

[Chemical 9]

[0039]

[Chemical 10]

[0040]

[Chemical 11]

[0041]

[Chemical 12]

(In chemical formula 12, m represents an integer from 1 to 22.)

[0043]

[Chemical 13]

(In chemical formula 13, q represents an integer from 1 to 11.)

As described above, the quaternary salt type polymer appropriately three-dimensionally cross-linked with the epoxy type curing agent is used as the ink absorbing layer, and silica fine particles are dispersed on the upper surface of this layer together with the water-soluble and alcohol-soluble polymer. By adhering to the surface in the form described above, a recording material that is excellent in ink absorption and fixing properties and does not cause blocking is formed, and these have excellent surface gloss and the above-mentioned structure is provided on a light-transmissive support such as a film. As a result, a recording material for OHP is provided. These are particularly useful for multicolor recording, and one of the characteristics is that the water resistance is dramatically improved.

[0046]

The present invention will be described in more detail with reference to the following examples.

Examples 1 to 5 Polymers having the compositions shown in Table 1 were synthesized, and each polymer was used as a 10% by weight aqueous solution to form a dry film on a paper (RC paper) whose surface was coated with polyethylene. It was coated and dried to a thickness of 10 microns. When the surface gloss of the formed ink absorbing layer was measured with a gloss meter (Gloss Checker, manufactured by Horiba Ltd.), the gloss was 70 or higher in any case. A coating liquid having the following composition was further coated on this coating layer as a coating liquid for overcoat so that the coating amount (wet coating amount) was 6 g / m ^2, and dried to obtain a recording material for ink jet.

Sylysia 350 (manufactured by Fuji Silysia Chemical Ltd., silica fine particles, average particle size 1.8 micron) 1.0 g Hydroxypropyl cellulose 0.4 g Methanol 80.0 g The resulting recording material is a full color ink jet printer manufactured by Canon Inc. Printing was performed using a pixel jet and the results shown in Table 2 were obtained.

Comparative Examples 1 to 5 As a comparison, the printing results obtained when the above overcoat coating liquid was not applied are also shown in Table 2 as comparative examples.
In the comparative example, the printed dots did not spread uniformly, and remarkable density unevenness occurred in the solid image. On the other hand, in each of the examples, the recording materials were excellent in glossiness of 30 or more, excellent in glossiness, excellent in resolution and uniformity of the solid portion, and free from blocking at all. When the surfaces of the recording materials obtained in Examples 1 to 5 were observed with a scanning electron microscope, it was confirmed that silica existed in a dispersed state on the surface and the lower polymer layer was exposed between silica particles. Was done.
The surface coverage of silica measured by an image analyzer was about 20%.

[0050]

[Table 1]

In Table 1, DMAPAA-Q = quaternary compound of dimethylaminopropylacrylamide with methyl chloride (trimethyl-3- (acryloylamino) propylammonium chloride), DMAEMA-Q = dimethyl chloride of dimethylaminoethylmethacrylate 4 Grade (trimethyl-2- (methacryloyloxy) ethylammonium chloride), VBTMAC = p-vinylbenzyltrimethylammonium chloride, DADMAC = diallyldimethylammonium chloride, AM = acrylamide, HEMA = 2-hydroxyethylmethacrylate, DMAP
AA represents dimethylaminopropyl acrylamide.

[0052]

[Table 2]

Comparative Examples 6 to 10 Polymers 1 to 5 shown in Table 1 were coated on RC paper in the same manner as in Example 1, and then a coating solution having the following formulation was used as an overcoat layer to give a dry film thickness of about 1 micron. The results obtained by coating and drying the above polymer layer on the above polymer layer and performing printing evaluation with an ink jet printer in the same manner as in Example 1 as a recording material are shown in Table 3.

Comparative overcoat coating liquid Sylysia 350 (manufactured by Fuji Silysia Chemical Ltd., silica fine particles) 10 g Polyvinyl alcohol (Kuraray, PVA-117) 2 g Distilled water 100 g In this case, when printing was performed, the printing quality of the solid part was good. However, the entire surface of the recording material was covered with silica, the glossiness was less than 20, and the printing result was low gloss and low resolution.

[0055]

[Table 3]

Examples 6 to 10 Polymers having the compositions shown in Table 4 were synthesized, each polymer was made into a 10% by weight aqueous solution, and 10% by weight of the epoxy curing agent shown in Chemical formula 5 was added to the polymer. The obtained aqueous solution was used as a coating liquid, and these were applied on a 100-micron-thick polyester film subjected to an aqueous undercoating treatment so that the dry film thickness was about 10 microns, and dried. After heating at a temperature of 40 ° C. for one day and night, a coating liquid having the following composition as a coating liquid for overcoating was further applied on the coating layer at a coating amount (wet coating amount) of 1
A recording material for an ink jet was obtained by coating and drying it so that the amount became 0 g / m ² .

Sylysia 435 (manufactured by Fuji Silysia Chemical Ltd., silica fine particles, average particle size 2.5 micron) 1.0 g Water / alcohol soluble polymers A to E 0.5 g (solid) methanol 60.0 g Water / alcohol soluble here As the polymer, A = polyvinylpyrrolidone, B = hydroxyethyl cellulose,
C = chitosan, D = polyacrylic acid, E = acrylamide-N-isopropylacrylamide copolymer (2: 7
Weight ratio) was used. The surface of the obtained recording material was covered with silica by about 20%, and printing was performed using a full color ink jet printer pixel jet manufactured by Canon Inc., and the results shown in Table 5 were obtained.

Comparative Examples 11 to 15 In place of the overcoat coating solutions of Examples 6 to 10, the following overcoat coating solutions were applied in a wet coating amount of about 10 g / m ^2.
Table 5 shows the results of each printing when applied so that
The results are shown as comparative examples.

Comparative overcoat coating liquid Sylysia 358 5.0 g Styrene-methyl methacrylate-methacrylic acid (40:30:30 weight ratio) Copolymer F 5.0 g (solid) Methanol 50.0 g

In the case of Comparative Example, when the surface of the recording material was observed with a scanning electron microscope, 60% or more of the surface was covered with silica, and the surface of the silica particles was covered with a binder polymer. When the recording material obtained in the comparative example was subjected to the same printing evaluation, the ink absorption was poor and the ink was transferred to the guide roller due to the ink overflow, and the density at the solid part was not uniform and the image quality was poor. Was bad. In this case, the transparency of the recording material was also poor. On the other hand, all of the recording materials obtained in this example show good print quality and are excellent in transparency, and even if the recording material after recording is washed with water, no decrease in image density or peeling of the film occurs. It was extremely excellent in water resistance.

[0061]

[Table 4]

In Table 4, DAM = dimethyl acrylamide, D
MAEMA represents dimethylaminoethyl methacrylate.

[0063]

[Table 5]

The evaluation methods of the evaluation items in Tables 2, 3, and 5 and the definition of the evaluation results are as follows. Uniformity of solid areas Visually judge each single color of yellow, magenta, cyan, and black and their heavy colors. ◯: A uniform solid without any overflow of ink, ×: A solid surface with rough or spilled ink. Resolution Visually judge thin lines with line width and spacing of 125 μm. ◯: The lines are clearly separated, and ×: the lines appear thick and sticky due to bleeding. Gloss Judgment based on visual inspection and glossiness. ◯: There is a glossy feeling, the glossiness is 30 or more, x: There is no glossy feeling, and the glossiness is less than 30. Blocking Property The front and back surfaces of recording materials are superposed on each other, and a pressure of 0.5 kg / 100 cm ² is applied, and the recording material is left in a room at 20 ° C. and 65% RH for 24 hours.
○: No blocking, ×: Blocking occurred. Water resistance Drop water on the printed image and wipe it off with a cloth after 1 minute. ◯: No peeling of the coating layer and no discoloration or bleeding of the printed image. X: Peeling of the coating layer or discoloration or bleeding of the printed image is recognized. Transparency Visual judgment. ◯: Transparent and the saturation of the printed image is high, ×: Low transparency, and the printed image looks cloudy.

[0065]

INDUSTRIAL APPLICABILITY According to the present invention, a recording material for ink jet recording having a good printing quality and excellent in gloss and transparency can be obtained.

Claims (7)

[Claims] 1. A support having an ink absorbing layer containing a water-soluble polymer having a quaternary ammonium salt group, and silica fine particles on the upper surface of the ink absorbing layer, and 10% by weight based on the weight of the silica fine particles. A coating liquid containing a polymer soluble in both water and alcohol in a proportion of not less than 150% and not more than 0.3 g / m ² and the silica fine particles are 5% of the total surface area of the ink absorbing layer. A recording material for ink jet recording, characterized in that the recording material is applied so as to be present at a coverage in the range of 50% to 50%. 2. The recording material according to claim 1, wherein the silica fine particles have an average particle size of 1 micron or more and 5 microns or less. 3. The water-soluble polymer having a quaternary ammonium salt group according to claim 1 is a water-soluble polymer obtained by polymerizing at least a monomer selected from Chemical formula 1, Chemical formula 2, and Chemical formula 3. Recording material. [Chemical 1] (In Chemical Formula 1, R ¹ represents hydrogen or a methyl group, Q represents an oxygen or NH group. R ² , R ³ , and R ⁴ represent a methyl group or an ethyl group, and may be the same or different. X represents a halogen ion or a sulfonate anion, an alkyl sulfonate anion, an acetate anion, an alkyl carboxylate anion, and n represents an integer of 2 or 3.) (R ⁵ , R ⁶ and R ^{7 in} Chemical Formula 2 represent a methyl or ethyl group and may be the same or different. X is the same as X in Chemical Formula 1.) (R ⁸ , R ⁹ and R ^{10 in} Chemical Formula 3 represent a methyl, ethyl or allyl group and may be the same or different. X is the same as X in Chemical Formula 1.) 4. The water-soluble polymer having a quaternary ammonium salt group according to claim 1 or 3 comprises 10 to 50 parts by weight of a monomer selected from Chemical formula 1, Chemical formula 2 and Chemical formula 3, and 1 to 1 of the monomer represented by Chemical formula 4. 30 parts by weight, and further as a water-soluble monomer, acrylamide, methacrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, diacetone acrylamide, N-methylol acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth ) Acrylate, N
20 to 80 monomers selected from vinylpyrrolidone
A recording material, which is a water-soluble polymer obtained by copolymerization in the range of parts by weight. [Chemical 4] (In the formula 4, R ¹¹ represents hydrogen or a methyl group, and R ¹² , R ¹³
Represents a methyl group or an ethyl group, and may be the same or different. Q represents oxygen or an NH group. n is 2
Alternatively, it represents an integer of 3. ) 5. A recording material, characterized in that a three-dimensionally crosslinked ink absorbing layer is formed by adding an epoxy curing agent together with a water-soluble polymer having a quaternary ammonium salt group according to claim 1, 3 or 4. 6. The ink absorbing layer according to claim 1, which does not contain inorganic fine particles such as silica in an amount of 10 parts by weight or more in addition to the polymer having a quaternary ammonium salt group, and the surface gloss of the ink absorbing layer alone is JIS. A recording material having a glossiness of 30 or more measured at an angle of 60 degrees according to the standard. 7. The polymer according to claim 1, wherein the polymer that is soluble in both water and alcohol contained together with the silica fine particles is polyvinylpyrrolidone and a copolymer thereof.
A recording material, which is a polymer selected from hydroxyethyl cellulose, hydroxypropyl cellulose, chitosan, polyacrylic acid and its copolymer, polyisopropylacrylamide and its copolymer.