JPH0986033A - Ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet having high aq. ink absorbability or absorbing capacity, especially high in glossiness, showing permeability when a support is transparent and excellent in water resistance. SOLUTION: In an ink jet recording sheet wherein an ink receiving layer is applied to a support, the ink receiving layer is based on polyviyl alcohol alone or polyvinyl alcohol and colloidal silica and the dye fixing agent in the ink receiving layer is a cationic polymeric dye fixing agent and a curing agent of polyvinyl alcohol is a melamine resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet, and more specifically, it is an ink jet recording sheet having good ink absorbency, high gloss, and water resistance. Slides and OHP
An ink jet recording sheet having high transparency and water resistance with respect to a recording sheet on which a recorded image is projected on a screen by an optical device such as an (over head projector).
It is about G.

[0002]

2. Description of the Related Art The ink jet recording system is used in various printers and the like because it has little noise, does not require processes such as development and fixing, and can easily perform full color recording, and has been rapidly popularized in recent years. . Especially computer
In recent years, a color image is formed by a computer, a recording apparatus can be made relatively small, and the maintenance of the apparatus is easy, and the driving sound and the recording sound are very low. It is used as a recording medium for facsimiles and various printers.

By improving the performance of an ink jet printer using water-based ink, such as printing speed and resolution, high-speed absorption, high absorption capacity, and regular ink can be achieved even for recording sheets. With the demand for more advanced characteristics such as the dot diameter, the so-called coated paper having an ink receiving layer provided on a support has been developed.

Further, a silver salt type color which is a photosensitive substance.
In addition to the above required performance to obtain a recording quality comparable to that of a photograph,
It is required that the surface be glossy and that the whiteness be high. Further, high transparency is required for a recording sheet where a recorded image is projected on a screen by an optical device such as a slide or an OHP (over head projector).

Conventionally, as an ink jet recording sheet having good ink absorption and high glossiness, a recording sheet provided with an ink receiving layer made of a water-soluble resin such as polyvinyl alcohol or polyvinyl pyrrolidone is used. Are known. However, such a recording sheet has a drawback in that the water resistance of the ink receiving layer is poor, and when the image gets wet with water, the ink oozes out to stain the sheet or the receiving layer is easily melted.

JP-A-5-124330 proposes to use alumina sol as a pigment for an ink receiving layer having good ink absorbency and water resistance. However, an ink receiving layer using such a pigment does not have a high specular gloss, and has poor transparency for ink jet recording sheets made using a transparent polyester film support, such as slides and OHPs. There was a problem.

In addition, it is a sheet having excellent transparency and a high surface gloss.
In order to obtain water resistance, it is necessary to provide a transparent receiving layer as much as possible. Further, in order to obtain water resistance, the receiving layer is insolubilized.
Since it does not have a porous structure like that of plain paper or plain paper, it has a drawback in that a portion with a large amount of ink cannot absorb the ink and uneven density or a mixed portion of different colors causes a blur at the boundary.

[0008]

As described above, the glossy paper for forming an image having gloss on the surface, and the slide and OHP recording sheet having excellent transparency have good water resistance, In addition, high-speed ink absorption and high absorption capacity are required.

Therefore, the problem to be solved by the present invention is
An object of the present invention is to provide an inkjet recording sheet having high water-based ink absorbency and absorption capacity, particularly high glossiness, and showing transparency when the support is transparent, and having excellent water resistance. It is a thing.

[0010]

The present invention has been made for the purpose of solving the above-mentioned problems, and its constitution is an ink jet recording sheet having an ink receiving layer on a support, wherein the ink receiving layer is The main component of the binder to be formed is polyvinyl alcohol alone or polyvinyl alcohol and colloidal silica, and is characterized by containing a melamine resin and a cationic polymer dye fixing agent.

That is, as a result of earnest research aimed at solving the above-mentioned problems, as a result of using polyvinyl alcohol alone or in a mixture with colloidal silica, which has high absorbency and absorption capacity of water-based ink, permeability and gloss are improved. Water resistance and ink receptivity are improved, and by using a melamine resin and a cationic polymer dye fixing agent in combination, water resistance is good, there is no density unevenness or boundary bleeding, high surface glossiness, and excellent transparency. -The present invention has been completed by finding out that it is possible to obtain the advantages.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The inkjet recording sheet of the present invention is obtained as follows. In order to obtain a sheet having a high surface gloss as a support, high-quality paper, biaxially stretched film, or biaxially stretched synthetic paper having cavities inside is used. Slides and OHP
For the purpose of high transparency such as a recording sheet for use, a transparent film is used. Further, for the purpose of improving the adhesive strength between the support and the receiving layer, in the case of a biaxially stretched film, a biaxially stretched type synthetic paper or a transparent film having a cavity inside, corona treatment or undercoating is performed. You can also

Next, a receiving layer is provided on the support, and as the binder, polyvinyl alcohol is used alone, or polyvinyl alcohol and colloidal silica are mixed and used. Polyvinyl alcohol has a high saponification degree of 70 to 90, which has high absorbency and absorption capacity for aqueous ink.
The mol% is good, and in order to enhance the strength and water resistance of the receiving layer, the degree of polymerization is preferably 100 or more.

Further, in order to enhance the absorbability of the water-based ink and reduce the amount of polyvinyl alcohol dissolved in water, mixing with colloidal silica is effective. However, when the amount of colloidal silica added is large, the gloss and the permeability are impaired, and when the colloidal silica is 50 parts or more based on 100 parts by weight of the solid content of polyvinyl alcohol, the glossiness is remarkably reduced. Not preferable.

The colloidal silica used in the present invention is
It is necessary that the average particle diameter is 1 to 50 nm. When the average particle diameter exceeds 50 nm, the ink acceptability is improved, but the glossiness is lowered, which is not preferable.

In order to improve the water resistance, it is necessary to add a melamine resin to the above-mentioned polyvinyl alcohol alone or a mixed solution of polyvinyl alcohol and colloidal silica. Here, the melamine resin used is preferably cationic or nonionic, and in particular, cationic acid colloids are particularly good in insolubilizing the receiving layer and absorbing the aqueous ink. The mixing ratio of the melamine resin is 100 parts by weight of the solid content of the above resin, and the solid content of the melamine resin is 0.
The amount of melamine resin is preferably from 01 to 10 parts, and when the amount of melamine resin is large, insolubilization proceeds, the absorbability of the water-based ink deteriorates, density unevenness and boundary bleeding occur, and printing is disturbed.

Further, a cationic polymer dye fixing agent is used to further improve the fixing property of the aqueous ink. As the cationic polymer dye fixing agent, higher alkyl amine,
Higher fatty acid amides can be used. Among them, polymeric fixing agents are preferable because they have excellent film-forming properties.

Next, regarding the amount of the cationic polymer dye fixing agent added to the binder, the solid content weight of the above resin is 100.
The solid content of the cationic polymer dye fixing agent is preferably 1.0 to 10 parts by weight per part. If the addition amount is less than the above numerical value, when the image gets wet with water, the ink bleeds and the sheet becomes dirty, etc., and there is no effect in achieving the intended purpose of the present invention. It is not preferable because the receiving layer is not insolubilized, the blocking property as a sheet is poor, and the cost is increased.

When the support is a non-transparent support such as high quality paper or biaxially stretched synthetic paper, a cationic fluorescent whitening agent is added to the ink receiving layer as a means for making the recording sheet look white. Use is effective.

Since the ink receiving layer of the present invention contains a cationic component as its constituent component, when a fluorescent whitening agent having anionic or anionic ionic property is used, the fluidity of the coating liquid is remarkably changed. Not only is the coating difficult, but even if coating is possible, the effect of the optical brightener will be lost. The fluorescent whitening agent used in the present invention, because its ionicity is cationic, can produce a whitening effect without causing any problems when an anionic or nonionic fluorescent whitening agent is used. It is possible. A naphthalimide-based optical brightening agent is preferably used as the cationic optical brightening agent.

The amount of the cationic optical brightening agent added is 0.1 with respect to 100 parts by weight of the solid content of polyvinyl alcohol.
It is preferably 10 parts. When the addition amount exceeds 10 parts, the water resistance of the ink receiving layer is lowered, and when the image is wet with water, not only the ink may ooze out but also the cost is increased. If the amount added is less than 0.1 part, the whitening effect will be insufficient.

Further, in the ink receiving layer, as other additives, a surfactant, a thickener, a fluidity improver, a defoaming agent, a foam suppressor, a release agent, an ultraviolet absorber, an antioxidant. Etc. may be appropriately used depending on the production conditions and required performance.

In order to obtain the ink-receiving layer of the present invention, polyvinyl alcohol is dissolved by boiling to uniformly disperse the above-mentioned constituents into a coating solution, for example, a bar coater or a brush. It is coated on the support by a coating method such as a coater, an air knife coater, a lip coater, and a comma coater. After coating, if necessary, a super calendar treatment may be carried out for smoothing the surface.

The preferable thickness of the ink receiving layer is 2
To 100 μm, and more preferably 10 to
40 μm. If it is less than 2 μm, the ink cannot be completely absorbed and the ink drying property is poor. Even if the thickness of the ink receiving layer is 100 μm or more, the intended effect of the present invention is not significantly impaired.

[0025]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. In the examples and comparative examples, all parts by weight are indicated by numerical values in terms of solid content. Example 1 1% of a 10% by weight aqueous solution of polyvinyl alcohol (PVA217, manufactured by Kuraray Co., Ltd.) having a saponification degree of 88 mol%
Melamine resin (trade name Beckamine MA-
S, solid content 60%, 5 parts by weight of Dainippon Ink and Chemicals Inc. was added, and a dye fixing agent (trade name: Sumirez Resin 100) was added.
1, solid content 30%, Sumitomo Chemical Co., Ltd.) 10% by adding water
5 parts by weight were added, and the mixture was sufficiently stirred and mixed to obtain a coating liquid. This coating solution was applied on the corona discharge treated surface of a milky-white polyethylene terephthalate film with a bar coater so that the thickness of the coating layer after drying would be 15 μm to obtain a recording sheet. It was

Example 2 Colloidal silica having an average particle diameter of 14 nm (trade name: Silica Dol 20A, SiO2 content 20%, manufactured by Nippon Kagaku Kogyo Co., Ltd.) and the polyvinyl alcohol used in Example 1 were used in a solid content ratio of 30. : 70. 10 of this mixed slurry
5 parts by weight of the melamine resin used in Example 1 and 5 parts by weight of the dye fixing agent used in Example 1 were added to 0 parts by weight, and sufficiently stirred and mixed to obtain a coating solution. Thereafter, coating was performed in the same manner as in Example 1 to obtain a recording sheet.

Example 3 A coating solution prepared in the same manner as in Example 1 was mixed with a cationic fluorescent whitening agent (trade name: Mica White ACR Liquid, active ingredient 10).
5% by weight (0%, manufactured by Nippon Kayaku Co., Ltd.) was added and mixed sufficiently with stirring to obtain a coating liquid. Thereafter, coating is carried out in the same manner as in Example 1,
A recording sheet was obtained.

Example 4 The coating solution prepared in the same manner as in Example 2 was added with the optical brightener used in Example 3 and mixed sufficiently with stirring to obtain a coating solution. Thereafter, coating was performed in the same manner as in Example 1 to obtain a recording sheet.

Example 5 Colloidal silica used in Example 2 and saponification degree 80mo
1% polyvinyl alcohol (trade name PVA403,
(Manufactured by Kuraray Co., Ltd.) in a 10% by weight solids ratio of 10: 9
Mixed to 0. To 100 parts by weight of this mixed slurry, 5 parts by weight of the melamine resin used in Example 1 and 5 parts by weight of the dye fixing agent used in Example 1 were added, and 5 parts of the optical brightener used in Example 3 was added. A part by weight was added and sufficiently stirred and mixed to obtain a coating liquid. Thereafter, coating was performed in the same manner as in Example 1 to obtain a recording sheet.

Example 6 The colloidal silica used in Example 2 and the polyvinyl alcohol used in Example 1 were mixed at a solid content ratio of 10:90. To 100 parts by weight of this mixed slurry, 0.01 parts by weight of the melamine resin used in Example 1 and 1 part by weight of the dye fixing agent used in Example 1 were added, and the optical brightener used in Example 3 was added. 5 parts by weight of the above were added and sufficiently stirred and mixed to obtain a coating liquid. Thereafter, coating was carried out in the same manner as in Example 1, and a recording sheet was used.
Got

Example 7 A coating solution was prepared and coated in the same manner as in Example 6 except that the melamine resin used in Example 1 was 10 parts by weight and the dye fixing agent used in Example 1 was 10 parts by weight. Then, a recording sheet was obtained.

Example 8 A coating solution was prepared and coated in the same manner as in Example 6 except that the melamine resin used in Example 1 was 10 parts by weight and the dye fixing agent used in Example 1 was 1 part by weight. Then, a recording sheet was obtained.

Example 9 A coating liquid was prepared in the same manner as in Example 6 except that the melamine resin used in Example 1 was 0.01 part by weight and the dye fixing agent used in Example 1 was 10 parts by weight. Then, coating was performed to obtain a recording sheet.

Example 10 A coating solution was prepared and coated in the same manner as in Example 3 except that the melamine resin was replaced with a melamine resin acid colloid (trade name: Sumirezin AC, solid content 8%, manufactured by Sumitomo Chemical Co., Ltd.). A recording sheet was obtained.

Example 11 The coating solution prepared in the same manner as in Example 1 was bar-coated on the corona discharge treated surface of a transparent polyethylene terephthalate film.
Coat so that the thickness after drying will be 15 μm,
A recording sheet was obtained.

Comparative Example 1 Polyvinyl alcohol as saponification degree 98.5 mol%
Polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray Co., Ltd.) was used, and a coating liquid was prepared and coated in the same manner as in Example 5 except that no optical brightener was used. -I got it.

Comparative Example 2 A coating liquid was prepared and coated in the same manner as in Example 6 except that the melamine resin used in Example 1 and the dye fixing agent used in Example 1 were not used. I got a sheet.

Comparative Example 3 A coating sheet was prepared and coated in the same manner as in Example 6 except that the dye fixing agent used in Example 1 was not used to obtain a recording sheet.

Comparative Example 4 A coating solution was prepared and coated in the same manner as in Example 6 except that the melamine resin used in Example 1 was not used to obtain a recording sheet.

Comparative Example 5 A coating solution was prepared and coated in the same manner as in Example 6 except that the melamine resin used in Example 1 was 15 parts by weight and the dye fixing agent used in Example 1 was 5 parts by weight. Then, a recording sheet was obtained.

Comparative Example 6 Coating was carried out in the same manner as in Example 3 except that the melamine resin used in Example 1 was replaced with glyoxal (trade name Beckamine LK-S, solid content 50%, manufactured by Dainippon Ink and Chemicals, Inc.). A working solution was prepared and coated to obtain a recording sheet.

Comparative Example 7 The cationic optical brightening agent used in Example 3 was replaced by an anionic optical brightening agent (trade name: Keicol BXNL, active ingredient 10).
The coating liquid was prepared in the same manner as in Example 3 except that the coating liquid was replaced with 0%, manufactured by Nippon Soda Co., Ltd., but the coating liquid gelled and coating was impossible.

Comparative Example 8 The coating solution was prepared and coated in the same manner as in Example 3 except that the amount of the cationic optical brightener used in Example 3 was changed to 15 parts by weight to obtain a recording sheet. It was

Comparative Example 9 The colloidal silica used in Example 2 and the polyvinyl alcohol used in Example 1 were mixed at a solid content ratio of 60:40. To 100 parts by weight of this mixed slurry, 5 parts by weight of the melamine resin used in Example 1 and 5 parts by weight of the dye fixing agent used in Example 1 were added, and sufficiently stirred and mixed to obtain a coating solution. . Thereafter, coating was performed in the same manner as in Example 1 to obtain a recording sheet.

Comparative Example 10 A coating solution was prepared in the same manner as in Comparative Example 9. Thereafter, coating was carried out in the same manner as in Example 11 to obtain a recording sheet.

The evaluation of each characteristic in Examples and Comparative Examples is as follows. 75 ° glossiness Measured according to JIS P 8142. Dryability After printing with an Epson Full Color Printer-700V2C and leaving it at room temperature (20 ° C., 65% RH) for 15 seconds, when the recorded image is touched with a finger, the ink is taken into the ink receiving layer. It was evaluated on a scale of 4 according to whether it adhered to the finger. (In order of goodness, ◎, ○, △, ×.)

Water resistance 1 After printing with a full color printer 700V2C manufactured by Epson Corporation, water droplets were attached to the recorded image, and after 1 minute, wiped with absorbent cotton to evaluate the disappearance of the image. (In good order,
◎, ○, △, ×. ) Water resistance 2 After printing with an Epson full color printer 700V2C, water droplets are attached to the recorded image and left for 24 hours,
The degree of ink bleeding was evaluated on a 4-point scale. (In good order,
◎, ○, △, ×. )

Image The recorded image was visually observed, and the sharpness of the image, the blurring of the boundary between two different colors, or the clarity of the fine line was evaluated in four levels. (In order of goodness, ◎, ○, △, ×.) Haze The difference between the haze (A) of the support before coating and the haze (B) of the unprinted portion after coating was calculated by the following formula, and Result (C)
showed that. Haze (C) = Haze of unprinted portion after coating (B)-Haze of support before coating (A) The haze was measured according to JIS K 7105.

Fluorescent intensity The fluorescent intensity was measured with a colorimetric color difference meter Z-1001DP manufactured by Nippon Denshoku Industries Co., Ltd. Visual Whiteness The recording sheet was visually observed, and the whiteness of the printed surface was evaluated in three levels. (Good, good, bad, bad.)

[0050]

[Table 1]

[0051]

[Table 2]

The following is clear from Tables 1 and 2. That is, according to the present invention, in the system in which the melamine resin and the cationic dye fixing agent are used in combination (Examples 1 to 11), the system in which the melamine resin and the cationic dye fixing agent are used in combination or not (Comparative Examples 2, 3, 4) It can be seen that, compared with, the water resistance is obviously good, a high glossiness can be realized, and a clear image can be obtained. In addition, melamine resin,
When the amount is more than necessary (Comparative Example 5), sufficient drying property and clear image cannot be obtained. Furthermore, even if a resin other than melamine is used to make it water resistant (Comparative Example 6), it is not possible to obtain the same good results as the melamine resin.

On the other hand, by using colloidal silica (Examples 2, 4, 5, 6, 7, 8, 9), the drying property, water resistance and image are improved, but the amount of colloidal silica is increased. When the amount is large, the gloss is low (Comparative Example 9) and the haze is high (Comparative Example 10). When a polyvinyl alcohol having a saponification degree of more than 90 is used (Comparative Example 1),
Compared with the polyvinyl alcohol having a saponification degree of 90 or less (Examples 1 to 11), the ink absorbency is obviously lowered, the drying property and the image are deteriorated, and the water resistance is also good. Can not.

Further, by using a cationic fluorescent whitening agent (Examples 3 to 10), it is possible to easily whiten the recording sheet without deteriorating various characteristics. However, when the addition amount is large (Comparative Example 8), the water resistance decreases,
When a non-cationic optical brightener is used (Comparative Example 7), coating becomes difficult.

[0055]

As described in detail above, according to the ink jet recording sheet of the present invention, it is possible to obtain a sheet having a high water-based ink absorbency and a high absorbing capacity and a particularly high gloss. Further, when the support is transparent, high transparency is exhibited, water resistance is excellent, and a clear image can be obtained.

Claims (10)

[Claims] 1. An ink jet recording sheet comprising an ink-receiving layer coated on a support, wherein the ink-receiving layer is mainly composed of polyvinyl alcohol or polyvinyl alcohol.
An ink jet printer characterized in that it is a rucolol and colloidal silica, the dye fixing agent in the ink receiving layer is a cationic polymer dye fixing agent, and the curing agent of the polyvinyl alcohol is a melamine resin. Recording sheet
G. 2. An ink jet recording sheet comprising an ink-receiving layer coated on a support, wherein the ink-receiving layer is mainly composed of polyvinyl alcohol or polyvinyl alcohol.
Ru alcohol and colloidal silica, the dye fixing agent in the ink receiving layer is a cationic polymer dye fixing agent, and the curing agent of the polyvinyl alcohol is a melamine resin. An inkjet recording sheet characterized by containing a whitening agent. 3. The ratio of the polyvinyl alcohol and colloidal silica is such that the solid content weight is 100: 0 to 50:50.
The inkjet recording sheet according to claim 1 or 2, wherein 4. The average particle size of colloidal silica is 1 to 5
The inkjet recording sheet according to claim 1, 2 or 3, wherein the thickness is 0 nm. 5. The polyvinyl alcohol according to claim 1, wherein the degree of saponification is 70 to 90 mol%.
2. The inkjet recording sheet according to 2, 3, or 4. 6. The solid content weight of the melamine resin is 0.01 per 100 parts by weight of the solid content of polyvinyl alcohol.
-10 parts, Claims 1, 2, 3, 4
Alternatively, the inkjet recording sheet according to item 5. 7. The cationic polymer dye fixing agent has a solid content of 1.0 to 10 parts by weight based on 100 parts by weight of the solid content of polyvinyl alcohol. The ink jet recording sheet according to 2, 3, 4, 5 or 6. 8. The cationic optical brightening agent is a naphthalimide-based optical brightening agent, and is 0.1 to 10 parts with respect to 100 parts by weight of the solid content of polyvinyl alcohol. The inkjet recording sheet according to claim 1, 2, 3, 4, 5, 6 or 7. 9. The ink jet recording sheet according to claim 1, wherein the glossiness is 75% specular gloss of 90% or more. Inkjet recording sheet. 10. The support is a fine paper, a biaxially stretched film, a biaxially stretched synthetic paper having cavities therein, or a transparent film.
The ink jet recording sheet according to 4, 5, 6, 7, 8 or 9.