JP3106460B2 - Colored sheet for pressure-sensitive copying - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color developing sheet for pressure-sensitive copying having ink jet recording suitability.

[0002]

2. Description of the Related Art A pressure-sensitive copying paper is composed of a paper on which a color-forming agent microcapsule composition mainly containing microcapsules containing an oily substance in which an electron-donating organic color-forming agent or the like is dissolved is coated on the back surface of a support. A medium paper on which a color developer composition mainly composed of an electron-accepting color developer that develops color when it comes into contact with the color developer is applied to the surface of the support, and the color former microcapsule composition is applied to the back surface And a lower paper coated with a developer composition on the surface of a support, and generally used in combination of upper paper-lower paper or upper paper-middle paper-lower paper in order of writing pressure, pressure of a printer, etc. The microcapsules are destroyed and the oil dissolving the color former transfers to the color developing layer,
The color is developed by reacting with the color developer. In addition, a self-coloring type pressure-sensitive copying paper in which a color developing agent and a color developing agent are applied on the same surface of a support to enable pressure-sensitive recording with one sheet is also known as one form thereof.

[0003] As a developer used in pressure-sensitive copying paper,
Inorganic color developing agents such as acid clay, activated clay and attapulgite, and organic developing agents such as phenol-formaldehyde resin, polyvalent metal salt of salicylic acid derivative, polyvalent metal salt of terpene phenol resin and polyvalent metal salt of salicylic acid-containing copolymer. Coloring agents are known.

[0004] Pressure-sensitive copying paper is used for various slips, and is used as a copying set of upper and lower sheets, or as a large number of copying sets with a required number of middle sheets sandwiched between upper and lower sheets. You. Further, a self-coloring type pressure-sensitive copy paper may be incorporated in the copy set. The sheets of these copy sets need to be adhered so that they do not fall apart and are separated one by one with the minimum necessary force.

[0005] Sorting glue is used when creating such a copy set, and a copy set is created by using the sorting glue in the following manner. That is,
Each of the pressure-sensitive copying papers is printed in the order of 10
cm, and the glue is applied to one end surface of the cut surface of the stack of the stacked copy sets, and the paste is dried. The set glue is glued inside the set (between the upper and lower papers, between the middle and middle papers, between the middle and lower papers)
The adhesive between the sets (between the base paper surface of the lower paper and the base paper surface of the upper paper) is designed so as not to be adhered. This utilizes the difference in permeation of the glue between the coated surfaces and the non-coated surface (base paper surface). If the separated glue cannot be used, the separation must be performed manually using the back glue.

Japanese Patent Application Laid-Open No. Hei 7-309058 discloses a method of improving the separability of a pressure-sensitive copying set, in which the contact angle of water on the uncoated surface of a paper having an uncoated surface in the set is determined. It has been proposed to apply or print the water-based ink so as to be 70 degrees or less.

[0007] On the other hand, slips made of pressure-sensitive copying paper have been used in the form of form printing by offset printing, letterpress printing or the like. In recent years, with the technical development of the ink jet recording method, examples have been seen in which the ink jet recording method is used for form printing. The use of the ink jet recording method has the advantages that plate making is not required and that the format can be easily changed.It can be used for printing small lots or printing or printing variable information such as bar codes on slips. For this reason, printing or printing using an ink jet recording method has been widely used for pressure-sensitive copying paper.

However, an ink jet recorded image formed on a conventional pressure-sensitive copying sheet by using an ink jet recording method has problems such as poor water resistance, bleeding of the ink jet recorded image when wet with water, and a decrease in recording density. is there. Further, there is a disadvantage that the ink bleeds at the time of forming an ink jet recorded image, and clear image quality cannot be obtained.

In order to improve this, Japanese Patent Application Laid-Open No. 3-236
No. 986 discloses that a cationic substance is blended in a color developing layer of a pressure-sensitive copying sheet. However, in order to stabilize the viscosity of the color developing layer coating liquid, it is generally desirable that the coating liquid is anionic. However, when a cationic substance is added to this anionic color developing layer coating liquid, the coating liquid becomes Thickening or gelling makes coating very difficult. In addition, the cationic substance acts on the color developer to lower the color developing ability, the color density of the pressure-sensitive recording is reduced, and a sufficient quality as a pressure-sensitive copy sheet cannot be obtained.

[0010]

SUMMARY OF THE INVENTION According to the present invention, when an ink jet recording system is used, a clear ink jet recorded image can be obtained, and blurring of the ink jet recorded image and a decrease in image density when wet with water can be prevented. It is another object of the present invention to provide a pressure-sensitive copying color developing sheet which maintains a sufficient color development density and a suitable combination of pastes as pressure-sensitive copying paper.

[0011]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention provides a pressure-sensitive copying developer sheet provided with a developer layer containing an electron-accepting developer as a main component on a support,
The contact angle measured 10 seconds after the dropwise addition of distilled water is 70 to 12
It relates to a pressure-sensitive copying sheet at 0 degrees.

The present invention is characterized in that the contact angle of the surface of the color developing layer with distilled water is in the range of 70 to 120 degrees.
If the contact angle 10 seconds after dropping into distilled water is 70 degrees or less, it is difficult to obtain a clear ink jet recorded image, and if the contact angle exceeds 120 degrees, which is almost the same as the contact angle of the base paper, the separated glue penetrates. This makes it difficult to classify the copy sets, and the function as pressure-sensitive copy paper is significantly reduced. In the present invention, in order to make the contact angle of the surface of the color developing layer with distilled water in the range of 70 to 120 degrees, the color of the color developing layer
It is adjusted by containing an acrylic resin emulsion.

In general, a water-soluble binder such as polyvinyl alcohol or starch is mainly used as the binder in the color developing layer in order to improve the coating suitability and printability of the paint and the quality of ink-jet printing. However, when a water-soluble binder is used, the water resistance of the coating layer is relatively weak, and the coating layer is easily rubbed off. Therefore, in the present invention, it is effective to add a water-resistant agent to the color developing layer and to cause a cross-linking reaction with the water-soluble binder to impart water resistance to the color developing layer. In addition, the presence of the water-proofing agent also improves the water resistance of the ink jet recorded image.

[0014]

Next, the present invention will be described in detail. The present invention is manufactured by providing a color developing layer containing an electron-accepting color developer as a main component on a support by a method known in the field of pressure-sensitive copying paper.

In the color developing sheet for pressure-sensitive copying of the present invention,
The contact angle with distilled water Akirairoso surface in the range of 70 to 120 degrees, an acrylic resin Emarujo in to Akirairoso
Adjusted by containing Yes. In addition, styrene
Maleic acid resin, alkyd resin, olefin resin,
Sizing agents such as rukirketene dimer, higher fatty acids, etc.
Emulsion, petroleum resin emulsion, silicone
Water repellent such as styrene-based emulsion, styrene / butadiene
Use of synthetic resin emulsions such as emulsions
Can be. Acrylic resin emulsions are particularly preferably used because they have good color density as a pressure-sensitive copying sheet, can provide excellent printability without causing a decrease in coating layer strength, and can provide clear ink jet recorded images. .

[0016] The blending amount of the acrylic resin d <br/> Marujo emissions used in the present invention is to be determined by the balance between the process and other components of the paint preparation, so that the contact angle with views is obtained is not particularly limited it may be added as appropriate, with respect to the total solid content of the normal color developing layer blending 0.1 to 30 wt%. Acrylic resin Emarujo emissions are more effective when the amount of at least 1% by weight.

Examples of the water-proofing agent that can be used in the present invention include various known water-proofing agents such as formalin, glyoxal, chromium ban, melamine, melamine formalin, polyamide epichlorohydrin resin, and urea compound. It is not something to be done. The amount of the water-proofing agent is not particularly limited and is determined by the balance between the type and the content of the water-soluble binder,
Usually, about 0.1 to 10% by weight is added to the total solid content of the color developing layer.

As the electron-accepting color developer used in the color-developing layer of the present invention, any of conventionally known organic and inorganic substances can be used. Specifically, examples of the organic developer include phenol formaldehyde resin, phenol acetaldehyde resin, phenol acetylene resin, and polyvalent metal salts thereof described in JP-B-42-14144; JP-B-49-55410. , And Tokubo Sho5
1-25174, benzoic acid, 4-methyl-nitrobenzoic acid, p-isopropylbenzoic acid, 2,
5-dinitrobenzoic acid, p-tert-butylbenzoic acid, 4-methyl-3-nitrobenzoic acid, salicylic acid, m
-Hydroxybenzoic acid, p-hydroxybenzoic acid,
3,5-dinitrosalicylic acid, 5-tert-butylsalicylic acid, 3-phenylsalicylic acid, 3-methyl-5
tert-butylsalicylic acid, 3,5-di-tert-
Butylsalicylic acid, 3,5-di-tert-amylsalicylic acid, 5-cyclohexylsalicylic acid, 3-methyl-
5-isoamylsalicylic acid, 5-isoamylsalicylic acid, 3,5-di-sec-butylsalicylic acid, 5-nonylsalicylic acid, 2-hydroxy-3-methylbenzoic acid,
2-hydroxy-5-tert-butylbenzoic acid, 5,
5-methylene disalicylic acid, acetaminobenzoic acid,
2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,5-di-α, α-dimethylbenzylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid,
1-hydroxy-2-naphthoic acid, 2-hydroxy-3
-Aromatic carboxylic acids such as -naphthoic acid, 2-hydroxy-1-naphthoic acid, and metal salts of the aromatic carboxylic acids with metals such as copper, lead, magnesium, zinc, aluminum, tin and nickel; 63-194876
Polyvalent metal salts of carboxy-modified terpene phenolic resins described in JP-A-48-8215; novolak salicylate resins described in JP-A-48-8215;
5, JP-A-63-53092, JP-A-63-18672
9 or a copolymer of salicylic acid and a compound such as an alkoxyxylene or a trialkylbenzene and a styrene derivative, or a polyvalent metal salt thereof;
Examples thereof include metal salts of oligobenzylated aromatic hydroxycarboxylic acids described in JP-A-63-132857. Among them, salicylic acid metal salts are
It is preferably used in terms of color density and storage stability. Examples of the inorganic developer include activated clay, acid clay, bentonite, apalgite, zeolite, montmorillonite, halloysite, kaolinite, and finely powdered silicic anhydride.
Activated clay obtained by eluting a part of the base component in the acid clay has a high color density and is preferred.

The pigments contained in the color developing layer of the present invention include calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, magnesium oxide, aluminum hydroxide, zinc hydroxide, kaolin, calcined kaolin, silica, barium sulfate, and the like. Examples thereof include magnesium silicate, aluminum silicate, and talc, but are not limited thereto.

Examples of the binder include water-soluble polymers such as starch, sodium alginate, gum arabic, dextrin, glue, gelatin, casein, collagen, viscose, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, and polyvinyl alcohol; Acrylic emulsions, vinyl acetate emulsions, styrene-butadiene copolymer emulsions and the like can be used, but these are not particularly limited.

In the coating solution for a color developing layer of the present invention, the above-mentioned color developing agent, pigment, binder, and various auxiliaries known in the field of pressure-sensitive copying paper are dispersed in water, and an acrylic resin emulsion is added thereto. Adjusted in a way. The method for preparing the coating liquid is not particularly limited, and is appropriately prepared according to a conventional method. In the color developer layer, the color developer usually contains 1% by weight to 20% by weight of the total solid content.
% By weight, about 50% by weight to about 95% by weight of a pigment, and about 1% by weight to about 40% by weight of a binder.

The method for applying the developing layer coating solution is not particularly limited, and the coating solution is applied to a substrate such as paper or synthetic paper using an air knife coater, a roll coater, a blade coater, a rod coater, a curtain coater or the like.

[0023]

EXAMPLES Hereinafter, the effects of the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, the part and% shown below show a weight part and weight%, respectively.

Example 1 Using a sand grinder,
25 parts of a 40% aqueous dispersion of zinc 3,5-di (α-methylbenzyl) salicylate having an average particle size of 2 μm, 100 parts of calcium carbonate, 10% polyvinyl alcohol (trade name: PVA-105, Kuraray Co., Ltd.) 100) Aqueous solution 100
Parts, carboxy-modified SBR latex as solid content of 8
Parts, an acrylic emulsion (trade name: AE-330, manufactured by Nippon Synthetic Rubber Co., Ltd.), 4 parts as solids, and 3 parts of glyoxal as solids, and a paint whose concentration was adjusted with water using an air knife coater. the coating is a coating weight of about 6 g / m ² on a dry weight 40 g / m ² base paper Te,
A pressure-sensitive copy-developed paper was obtained.

[0025]

Example 2 A pressure-sensitive color-developed paper was obtained in the same manner as in Example 1, except that glyoxal was not used in the same manner as in Example 1.

Example 3 The average particle size was adjusted to 2 μm by a sand grinder.
40 of zinc 5-di (α-methylbenzyl) salicylate
% Aqueous dispersion 25 parts, calcium carbonate 100 parts, 10%
100 parts of an aqueous solution of polyvinyl alcohol (trade name: PVA-105, manufactured by Kuraray Co., Ltd.), 8 parts of carboxy-modified SBR latex as a solid content, acrylic emulsion (trade name: AE-922 (A), Nippon Synthetic Rubber Co., Ltd.)
4 parts as a solid content, a cyclic urea compound (trade name:
4 parts of SUMIREZ REZIN 5004, manufactured by Sumitomo Chemical Co., Ltd.), and the paint whose concentration has been adjusted with water is applied to a base paper of 40 g / m ² using an air knife coater so as to have a coating weight of about 6 g / m ^{2 on} a dry weight basis. To obtain a pressure-sensitive copying color-developed paper.

Example 4 The average particle size was adjusted to 2 μm by a sand grinder.
40 of zinc 5-di (α-methylbenzyl) salicylate
% Aqueous dispersion 25 parts, kaolin 80 parts, 10% polyvinyl alcohol (trade name: PVA-105, Kuraray Co., Ltd.)
100 parts of an aqueous solution, 8 parts of a carboxy-modified SBR latex as a solid content, an acrylic emulsion (trade name:
AE-922 (A), manufactured by Nippon Synthetic Rubber Co., Ltd.) as solids, 4 parts, melamine formalin resin (trade name: SUM)
IREZ REZIN 613, manufactured by Sumitomo Chemical Co., Ltd.) 3
Part of the paint, the concentration of which was adjusted with water, and about 6 g / m ² by dry weight on 40 g / m ² base paper using an air knife coater.
To obtain a pressure-sensitive copy-developed paper.

[0029]

[0030]

[0031]

[Comparative Example 1] Paint preparation and application were performed in the same manner as in Example 1 except that the acrylic emulsion was completely replaced with a carboxy-modified SBR latex.
A pressure-sensitive copy-developed paper was obtained.

Comparative Example 2 The same procedure as in Comparative Example 1 was carried out except that glyoxal was not used in the same manner as in Comparative Example 1 except that the paint was prepared and applied to obtain a pressure-sensitive color-developed paper.

Comparative Example 3 A sand grinder
25 parts of a 40% aqueous dispersion of zinc 3,5-di (α-methylbenzyl) salicylate having an average particle size of 2 μm, 100 parts of calcium carbonate, 10% polyvinyl alcohol (trade name: PVA-105, Kuraray Co., Ltd.) 100) Aqueous solution 100
Parts, carboxy-modified SBR latex as solids
1 part, 3 parts of glyoxal as a solid content, and 0.5 part of a silicone emulsion (trade name: POLON-MF-18, manufactured by Shin-Etsu Chemical Co., Ltd.) as a solid content, and the paint whose concentration was adjusted with water was air-blended. Using a knife coater, 40 g / m ² base paper was coated so as to have a dry weight of about 6 g / m ² to obtain a pressure-sensitive color-developed paper.

[0035] except for changing the non-blended glyoxal in Comparative Example 4 Comparative Example 3, the paint prepared in the same manner as Comparative Example 3, was applied to obtain a pressure-sensitive copying sensible colored paper.

With respect to each of the above-mentioned color developing papers, the suitability for recording as a pressure-sensitive copying paper and the suitability for ink jet recording were evaluated by the following methods, and the results are shown in Tables 1 and 2. [Suitable for pressure-sensitive copying paper] Color density: Commercial top paper NW40T
(Manufactured by Nippon Paper Industries Co., Ltd.) and a developing paper are superposed on each other so that the coated surfaces face each other, and calendered at a linear pressure of 50 Kg / cm to form a color. The color density after 24 hours is measured using a Macbeth densitometer (RD914, Wratten # 106 filters, MAKU
BETH). (The larger the value, the better the color.) Contact angle: Goniometer-type contact angle measuring device, Elmer G-
Using Type 1 (manufactured by Elma Optical Instruments), 0.05 CC of distilled water was dropped on the surface of the developing layer, and the contact angle was measured after 10 seconds. This was performed five times, and the average value was obtained. Suitability of grouping glue: After stacking and cutting 500 sets of upper paper, middle paper, and lower paper (commercial upper paper NW40T, middle paper NW40M: manufactured by Nippon Paper Industries Co., Ltd.)
Using a paint brush on the cut surface, glue (separate bond K500A: manufactured by Nippon Paper Industries Co., Ltd.) was applied so that the brush passed the same place four times, and after one hour,
500 sets of pressure-sensitive copying paper were manually separated, the state of adhesion between the sets (between the lower sheet and the upper sheet) at that time was observed, and the set separation property was visually evaluated. The environmental conditions during the operation were 6 humidity.
The test was performed at 0% at a temperature of 20 ° C. ○ There is no adhesion between the lower paper and the upper paper. × It is adhered and hard to peel, or it does not peel at all.

[Appropriateness of ink-jet recording] Print quality (clearness): ink-jet printer BJC
-400J (manufactured by Canon Co., Ltd.) was used to perform printing, and the bleeding of the ink in the printed area was judged with a standard paper. ○ No bleeding △ Slight bleeding (no problem in practical use) × Large bleeding (impractical) Water resistance: The solid printed portion 24 hours after inkjet printing was immersed in distilled water at 20 ° C. for 30 seconds, and after air drying. A visual judgment was made on the decrease in the ink jet print density. ○ No decrease in print density △ Slight decrease in print density (to the extent that there is no practical problem) × Significant decrease in print density (impractical) Wet lab test: ADAMS WET RUB TE
Using STER (Mountage Co.),
Twenty-four hours after the ink jet printing, a wet rub test (a surface friction strength test when wet with water) was performed on the solid printed portion, and the degree of change (disappearance) of the ink jet printing before and after the test was visually judged. ○ No change △ Slightly disappeared but readable (no problem in practical use) × Unreadable

[0038]

[Table 1]

[0039]

[Table 2]

As is evident from the results shown in Table 1, in Examples 1 to 4 having a contact angle within the range specified in the present invention, qualities sufficiently satisfactory for practical use in pressure-sensitive copying suitability and ink jet recording suitability were obtained. Have been obtained . Hand, Comparative Example 1 which is small without adjusting the contact angle also contain a water resistant agent has poor water resistance of the ink jet print quality and image, also, the contact angle is more than the range defined in the present invention compared In Examples 3 and 4, there was a problem in the suitability of the glue.

[0041]

The color developing sheet for pressure-sensitive copying of the present invention can provide a clear ink jet recorded image when the ink jet recording system is used, and is excellent in water resistance of the ink jet recorded image. Further, since it maintains a sufficient color density as a pressure-sensitive copying paper and has good suitability for separating and assembling, it is very practical as a pressure-sensitive copying sheet used for a multi-copy slip.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshifumi Nishikubo 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Nihon Paper Industries Co., Ltd. Product Development Laboratory (56) References JP-A-3-236986 (JP, A) JP-A-2-167773 (JP, A) JP-A-7-137437 (JP, A) JP-A-7-205576 (JP, A) JP-A-4-70375 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 5/124

Claims (2)

(57) [Claims] 1. A pressure-sensitive copying color developing sheet in which a color developing layer containing an electron-accepting color developing agent as a main component is provided on a support, wherein an acrylic resin emulsion is blended with the color developing layer.
A pressure-sensitive copying color sheet for ink-jet recording, wherein the contact angle measured 10 seconds after dropping distilled water on the surface of the color-developing layer is 70 to 120 degrees. 2. A color developing sheet for pressure-sensitive copying according to claim 1, wherein a water resistance agent is added to said color developing layer.