JPH1029368A - Recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording sheet good in the slip proterties of the coupler coated surface and excellent in ink jet recording aptitude and the printability due to oily ink. SOLUTION: A recording sheet is formed by coating a support with a coupler dispersion obtained by adding solid disperse wax with an average particle size of 0.8μm or less to an aq. dispersion based on inorg. pigment and containing a phenol resin or a metal salt of aromatic carboxylic acid as a coupler to form a recording sheet adaptable to both of an ink jet recording sheet and a pressure-sensitive recording sheet. The solid wt. of the solid disperse wax is desirably 1-12wt.% with respect to the solid wt. of solid dispersion before solid disperse wax is added. This recording sheet can be used as a pressure- sensitive recording material being a combination of a coupler sheet having a coupler and a color forming sheet having a color forming agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a recording sheet, and more particularly to a recording sheet applicable to both ink jet recording and pressure recording. More specifically, the present invention relates to a recording sheet suitable for improving the slipperiness of a developer-applied surface and ink jet recording printing characteristics without deteriorating the printability of oil-based ink.

[0002]

2. Description of the Related Art The ink jet recording system has advantages such as easy multi-color recording, relatively high recording speed, and recording of large plates. On the other hand, nozzle clogging and maintenance, which has been a problem in the past, have been improved in terms of both ink and equipment, and are now widely used in various fields such as various printers, facsimiles, and computer terminals. Is rapidly spreading.

[0003] There is an application for partially recording an ink-jet method on a pressure-sensitive recording sheet. However, when a developed color sheet of a normal pressure-sensitive recording sheet is recorded by an ink-jet method, ink bleeding occurs. In addition, one of the problems when using a pressure-sensitive recording sheet in these apparatuses is transportability, and this transportability is often caused by slipperiness on the application surface of the recording sheet. As a conventional means for imparting lubricity to a coated surface, for example, a method of adding talc to a coating solution or a method of drying a coating solution surface, calendering the surface, and smoothing the coated surface, etc. There is.

[0004]

However, in the method of adding talc to a coating solution, there is a problem that the printability of oily ink on a coating surface is deteriorated, and bleeding of recording characters and the like becomes large, and ink jet printing is performed. There is a problem that the recording suitability deteriorates. On the other hand, we do calendering,
In the case of the method of smoothing the coated surface, there is a problem that the flexibility of the recording sheet is impaired, so that there is a dislike of a so-called stiff sheet, and the cost of equipment such as a calender device is increased.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording sheet suitable for improving the slipperiness of the coated surface and the ink jet recording printing characteristics without calendering, without deteriorating the printability of the oil-based ink. It is in.

[0006]

An object of the present invention is to provide an aqueous dispersion containing an inorganic pigment as a main component and a phenol resin or a metal salt of an aromatic carboxylic acid as a color developer having an average particle size of 0.8 μm or less. This is achieved by a recording sheet such as an ink jet recording sheet or a pressure-sensitive recording sheet obtained by applying a developer dispersion obtained by adding the solid dispersion wax of Example 1 on a support. The solid weight of the solid dispersion wax is preferably 1 to 12% by weight based on the solid weight of the dispersion before adding the solid dispersion wax.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The present invention is a recording sheet in which a developer dispersion is coated on a support, and the support has LBKP and NBPK.
And other base papers mainly made of wood pulp. This base paper may further contain a synthetic pulp, a synthetic fiber or the like as necessary. The base paper may contain a filler, a sizing agent, a paper strength enhancer, a fixing agent, and the like, if necessary.

[0008] As the filler, for example, clay, talc,
TiO ₂ , CaCO ₃ , BaSO _{4 and the} like can be mentioned. The content of the filler is usually 0 to 30 with respect to the pulp.
% By weight. Examples of the sizing agent include rosin, alkenyl succinate, stearate, alkyl ketene dimer, alkenyl succinic anhydride and the like.
Examples of paper strength agents include starch, gelatin, C
MC, polyacrylamide and the like. Examples of the fixing agent include aluminum sulfate, aluminum chloride, and polyamide polyamine epichlorohydrin.

The basis weight of the base paper is usually 30 to 250 g.
/ M ² , preferably 40 to 150 g / m ² . The thickness of the base paper is usually 30 to 250 μm, preferably 40 to 150 μm. The whiteness (hunter) of the base paper is preferably 70% or more, and the rigidity (Taber) of the base paper is preferably 1 to 29 g. The water absorption of the base paper is determined according to JIS
It is preferably from 10 to 30 g / m ² in -P-8140. If the water absorption is less than 10 g / m ² , ink flow may be likely to occur. On the other hand, if it exceeds 30 g / m ² , white spots may easily occur.

In addition to the above-described base paper, a thermoplastic synthetic resin film or the like can be used, and there is no particular limitation. Examples of the thermoplastic synthetic resin film include polyester, polystyrene, polyvinyl chloride, and polymethyl methacrylate.

The main component in the developer coating solution applied to the support as described above is an inorganic pigment. Examples of the inorganic pigment in the present invention include zinc oxide, titanium oxide, calcium carbonate, zinc carbonate, calcium sulfate, barium sulfate, zinc sulfide, clay, talc, titanium white, aluminum silicate, aluminum hydroxide, diatomaceous earth, and ken. Examples include at least one kind of acid, calcium citrate, magnesium silicate, alumina, lithopone, and the like.

As the color developer in the present invention, a phenol resin or a metal salt of an aromatic carboxylic acid is used. As the color developer, a metal salt of an aromatic carboxylic acid is particularly preferable because it has good color-developing properties for pressure-sensitive recording and does not significantly affect the ink absorbability of ink-jet recording. Specific examples of the developer include phenol formaldehyde resin, 3,5-di-t-butylsalicylic acid,
3,5-di-t-octylsalicylic acid, 3,5-di-t
-Nonylsalicylic acid, 3,5-di-t-dodecylsalicylic acid, 3-methyl-5-t-dodecylsalicylic acid, 3-
t-dodecylsalicylic acid, 5-t-dodecylsalicylic acid, 5-cyclohexylsalicylic acid, 3,5-di-α-
Methylbenzylsalicylic acid, 3-methyl-5- (α-methylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) -5-methylsalicylic acid, 3- (α, α-dimethylbenzyl) -6-methylsalicylic acid, 3- (α-methylbenzyl) -5- (α, α-dimethylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) -6-ethylsalicylic acid, 3-phenyl-5- (α, α-dimethylbenzyl) ) Salicylic acid, carboxy-modified terpene phenol resin, zinc salt, nickel salt, aluminum salt, calcium salt, etc., such as salicylic acid which is a reaction product of 3,5-bis (α-methylbenzylsalicylic acid and benzyl chloride). it can.

The solid dispersion wax added to the developer dispersion liquid includes animal and plant waxes such as wood wax, white wax, carnauba wax, beeswax, hardened wax, sugar wax, serracha wax, paraffin wax, microcrystalline wax, and the like. Examples include petroleum waxes such as ceresin wax, montan wax, powdered wax, oxidized paraffin, and slack wax, polyethylene wax, and other polyhydric alcohol esters and polyvalent metal salts of higher fatty acids.

The solid dispersion wax is used as a fine powder or an emulsion, and has an average particle size of 0.8.
It is necessary to be less than μm. 0.8μ average particle size
If it is larger than m, printability when printing the recording sheet with the oil-based ink is poor, resulting in poor print finish.

[0015] The solid dispersion wax in the present invention has a solid weight of 1 to 12% by weight based on the solid weight of the dispersion before adding the solid dispersion wax.
It is desirable that When the solid weight of the solid dispersion wax is less than 1% by weight, the suitability for ink-jet recording printing cannot be improved. On the other hand, when the solid weight of the solid dispersion wax is more than 12% by weight, the color density may be reduced. It is not preferable because of the decrease.

In the present invention, an aqueous binder can be used for the developer dispersion. Examples of the aqueous binder include polyvinyl alcohol or derivatives thereof, starches, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, casein, gelatin, maleic anhydride resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer. Acrylic copolymers such as polymers or copolymers of acrylic esters and methacrylic esters, and vinyl copolymers such as ethylene-vinyl acetate copolymer, and the like,
It is not limited to these. Further, in the developer dispersion liquid, a pigment dispersant, a thickener, a defoaming agent, a defoaming agent, and the like are added as necessary, in addition to the components described above, as long as the effects of the present invention are not impaired. be able to.

In the present invention, a developer dispersion containing the various components described above is applied to a support and dried to form a coating layer containing the developer. As a means for applying the dispersion to the support, any of an air knife coater, a blade coater, a roll coater, a curtain coater, a bar coater, a gravure coater and the like can be used. The developer dispersion is 1 to 15 solids on the support.
g / m ^2, preferably, it is coated to a 2 to 8 g / m ^2.

The present invention can be used not only as a recording sheet but also as a pressure-sensitive recording material in combination with a color former sheet as a color developer sheet.

[0019]

EXAMPLES Examples of the present invention will be described below. Unless otherwise specified, "parts" means "parts by weight". Example 1 Calcium carbonate (Brilliant-15, average particle size 0.5 μm)
m, Shiraishi Industry Co., Ltd.) 120 parts, activated clay 30 parts, zinc oxide 40 parts, 40% sodium hexametaphosphate aqueous solution 5
Parts and 230 parts of water, the mixture was uniformly dispersed with a sand glider so as to have an average particle size of 2 μm to obtain a pigment dispersion.

In 50 parts of this pigment dispersion, 10% PVA-1 was added.
17 (degree of saponification: 98%, degree of polymerization: 1,750, manufactured by Kuraray Co.) 40 parts of an aqueous solution, and 6 parts of 3,5-di- (α-methylbenzyl) zinc salicylate dispersion (solids concentration: 30%) In addition, 2.8 parts of a paraffin wax dispersion having a melting point of 68 ° C. (average particle size 0.8 μm, solid content concentration 30%) was added, and then water was adjusted so that the solid content concentration became 20%, and applied. A liquid was obtained. This coating solution was applied to a 50 g / m ² base paper using an air knife coater so that a solid content of 5.0 g / m ² was applied, and dried to prepare a recording sheet.

Example 2 Example 1 was repeated except that the paraffin wax dispersion having a melting point of 68 ° C. (average particle size: 0.5 μm, solid content: 30%) was used in place of the paraffin wax dispersion of Example 1. A recording sheet was prepared in the same manner as described above.

Example 3 Instead of the paraffin wax dispersion of Example 1, a paraffin wax dispersion (W-1) having an average particle size of 0.35 μm was used.
A recording sheet was produced in the same manner as in Example 1 except that 16H, solid content concentration 30%, manufactured by Arakawa Chemical Co., Ltd.) was used.

Example 4 A recording sheet was prepared in the same manner as in Example 1 except that the amount of the paraffin wax dispersion used in Example 1 was twice that of Example 1.

Comparative Example 1 A recording sheet was prepared in the same manner as in Example 1 except that the paraffin wax dispersion of Example 1 was not used.

Comparative Example 2 Example 1 was repeated except that talc (EF-100A, manufactured by Nippon Talc) was dispersed in water (solid content: 30%) instead of the paraffin wax dispersion of Example 1. A recording sheet was prepared in the same manner as described above.

Comparative Example 3 Instead of the paraffin wax dispersion of Example 1, melting point 6
8 ° C. paraffin wax dispersion (average particle size 2.5 μm)
m, solid content concentration 30%), except that a recording sheet was prepared in the same manner as in Example 1.

Comparative Example 4 A recording medium was prepared in the same manner as in Example 1 except that a liquid paraffin emulsion (average particle size: 0.5 μm, solid content: 30%) was used instead of the paraffin wax dispersion of Example 1. A sheet was prepared.

The recording sheets obtained as described above were evaluated for slipperiness, ink jet recording suitability, and printability with oil-based ink. [Evaluation of slipperiness] Combine so that the developer-coated surfaces of the prepared recording sheets are in contact with each other, measure the static friction coefficient and the dynamic friction coefficient using a friction coefficient measurement tester, and use the friction coefficient to determine the slip. Gender. (Note) The smaller the coefficient of friction, the better the slipperiness.

[Evaluation of Inkjet Recording Suitability] The ink was evaluated by a grading method in comparison with a standard bleeding sample by a pen writing size test (J. TAPPI No. 12). However, the ink used was an ink for inkjet recording. Poor (0) to good (6) were evaluated on a 7-point scale.

[Evaluation of Printability with Oil-Based Ink] Printing was performed on the developer-applied surface using an offset printing tester, and the print finish was visually judged. ：: good print finish, Δ: poor print finish, ×: extremely poor print finish The results are shown in Table 1.

[0031]

[Table 1]

Table 1 shows the following. When the solid dispersion wax was not used (Comparative Example 1), the coefficient of friction was large, the slipperiness was poor, and the suitability for inkjet recording was poor. When talc is used in place of the solid dispersion wax (Comparative Example 2), the lubricity is good, but the suitability for inkjet recording and printing with oil-based ink are poor.
When a 2.5 μm solid dispersion wax having an average particle size larger than 0.8 μm is used (Comparative Example 3), printability with oil-based ink is poor. Further, liquid paraffin is used instead of solid dispersion wax (Comparative Example 4)
In this case, the coefficient of friction is large, the slipperiness is poor, and the suitability for ink jet recording is slightly poor. On the other hand, when the average particle size is 0.8
When a solid dispersion wax having a particle size of μm or less is used (Examples 1 to 4), the coefficient of friction is small, the sliding property is good, and the suitability for inkjet recording and printing with oil-based ink are all excellent.

[0033]

As described above, according to the present invention, it is possible to provide a recording sheet having a low coefficient of friction, good slipperiness, and excellent ink jet recording suitability and printability with oil-based ink. This recording sheet contains a color developer and can be used as a color developer sheet, and can be used as a pressure-sensitive recording material in combination with a color former sheet.

Claims (4)

[Claims] 1. A solid dispersion wax having an average particle diameter of 0.8 μm or less is added to an aqueous dispersion containing an inorganic pigment as a main component and a phenol resin or a metal salt of an aromatic carboxylic acid as a color developer. A recording sheet, which is an ink jet recording sheet obtained by applying the obtained developer dispersion onto a support. 2. The ink jet recording sheet according to claim 1, wherein the solid weight of the solid dispersion wax is 1 to 12% by weight based on the solid weight of the dispersion before adding the solid dispersion wax. 2. The recording sheet according to 1. 3. A solid dispersion wax having an average particle diameter of 0.8 μm or less is added to an aqueous dispersion containing an inorganic pigment as a main component and a phenol resin or a metal salt of an aromatic carboxylic acid as a color developer. A recording sheet, which is a pressure-sensitive recording sheet obtained by applying the obtained developer dispersion onto a support. 4. The pressure-sensitive recording sheet according to claim 1, wherein the solid weight of the solid dispersion wax is 1 to 12% by weight based on the solid weight of the dispersion before adding the solid dispersion wax. Item 4. A recording sheet according to Item 3.