JPH09263046A - Coupling sheet for pressure-sensitive copy paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coupling sheet for pressure-sensitive copy paper developing desensitizing effect even if a desensitizing ink build-up amt. is little especially at a time of desensitizing printing and excellent in color forming properties and preservability as pressure-sensitive copy paper. SOLUTION: A coupling sheet is constituted by coating a support with a coating soln. containing a multivalent metal salt of a nucleus substituted aromatic carboxylic acid derivative and pigment as main components. In this case, poly[N,N-dimethyl-N-(2-hydroxypropyl)ammonium salt] is added to the coating soln. in an amt. of 2-10% by wt. of the total solid of the multlvalent salt of a nucleus substituted aromatic carboxylic acid derivative and the pigment.

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 paper, and particularly, at the time of desensitizing printing, a desensitizing effect is exhibited even if the amount of desensitizing ink is small, and pressure-sensitive copying is performed. The present invention relates to a color-developing sheet for pressure-sensitive copying paper which is excellent in color developability and storability as paper.

[0002]

2. Description of the Related Art A pressure-sensitive copying paper is prepared by applying a microcapsule composition containing microcapsules containing a hydrophobic core substance in which an electron-donating color former (leuco dye) is dissolved as a main component to one side of a support. The paper and the one side of the support were coated with a developer main component containing an electron-accepting developer as a main component, which was colored when contacted with the color former, and the other side was coated with a microcapsule composition. There is a middle paper and a lower paper in which the developer composition is applied to one side of the support, and these three types of sheets are practically used as a copy set by combining the upper paper, middle paper, lower paper or upper paper, and lower paper in this order. Has been converted. Also known as a form of pressure-sensitive copying paper is a self-coloring 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. Has been.

Conventionally, the pressure-sensitive copying paper is mainly used as a slip (form) paper, and the format of the slip is often printed by a printing specialist by letterpress printing or offset printing. However, in recent years, the demand for pressure-sensitive copying paper has been diversified, mainly with respect to general slips, delivery slips, contract documents, etc., with the expansion of its applications. Depending on the voucher structure, there may be areas where recording is not required on the developer application surface of the middle and lower sheets. In such a case, desensitizing ink containing desensitizer may be printed on the developer application surface. The desensitization method is applied to that part of the.

[0004]

However, in recent years, in the production of pressure-sensitive copying paper, when performing desensitizing printing,
If a large amount of desensitizing ink is not used, the desensitizing effect will not be expressed,
In addition, when the desensitizing ink is applied in a large amount, the drying of the desensitizing ink is delayed, and the number of cases causing printing problems such as set-off stains is increasing. Such a problem is remarkable in the case of black color development, which is less susceptible to desensitization than blue color development.

The object of the present invention is to produce a desensitizing effect even with a small amount of desensitizing ink during desensitizing printing, and for pressure-sensitive copying paper which is excellent in color developability and storability as pressure-sensitive copying paper. It is to provide a color-developing sheet.

[0006]

The present invention provides a color-developing sheet for pressure-sensitive copying paper, which comprises applying a coating liquid containing a polyvalent metal salt of a nuclear-substituted aromatic carboxylic acid derivative and a pigment onto a support. Poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt] is added to the coating liquid in an amount of 2 to 10 based on the total solid amount of the polyvalent metal salt of the nuclear-substituted aromatic carboxylic acid derivative and the pigment. The present invention relates to a color-developing sheet for pressure-sensitive copying paper, which is characterized in that it is contained by weight%.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the present invention comprises a developer layer containing a polyvalent metal salt of such a nucleus-substituted aromatic carboxylic acid derivative and containing a specific amount of a specific polymer. In the present invention, by using a polyvalent metal salt of a nuclear-substituted aromatic carboxylic acid derivative as a color developer, a color-developing sheet for pressure-sensitive copying paper excellent in color developability can be obtained, and a nuclear-substituted aromatic group in the color-developing layer. Based on the total solid amount of the polyvalent metal salt of the carboxylic acid derivative and the pigment,
By containing 2 to 10% by weight of poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt], desensitizing printability is improved. By the way, if the addition amount is less than 2% by weight, the desired effect of improving the desensitization printing aptitude cannot be obtained, and if it exceeds 10% by weight, the storage stability of the pressure-sensitive copy recorded image and the surface strength decrease. In addition, poly [N, N-
2 to 10% by weight of dimethyl-N- (2-hydroxypropyl) ammonium salt], the ink jet recording suitability can be improved.

Poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt used in the present invention]
Has the following structure.

[0009]

Embedded image

The degree of polymerization of the copolymer may be such that the effects of the present invention can be exhibited, and it can be widely used from relatively low molecular weight to high molecular weight. In general, it is preferable that n is 10 to 2000, but it is possible to use it even if it is out of the above range. In addition, a pigment is usually used in the developer layer, 50 to 95% by weight of the total solid content of the developer layer, and 1 to 1
It is preferable to add 20% by weight and 1 to 40% by weight of a binder.

The color developer used in the present invention is, for example, 3-phenylsalicylic acid, 3-cyclohexylsalicylic acid, 3-tert-butyl-5-methylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3-methyl. -5-benzylsalicylic acid, 3-phenyl-5- (α,
α-Dimethylbenzyl) salicylic acid, 3-cyclohexyl-5- (α, α-dimethylbenzyl) salicylic acid, 3
-(Α, α-Dimethylbenzyl) -5-methylsalicylic acid, 3,5-di-cyclohexylsalicylic acid, 3,5-di- (α-methylbenzyl) salicylic acid, 3,5-di-
(Α, α-Dimethylbenzyl) salicylic acid, 3- (α-
Methylbenzyl) -5- (α, α-dimethylbenzyl)
Salicylic acid, 4-methyl-5-cyclohexyl salicylic acid, 2-hydroxy-1-benzyl-3-naphthoic acid,
1-benzoyl-2-hydroxy-3-naphthoic acid, 3
-Hydroxy-5-cyclohexyl-2-naphthoic acid,
2-Hydroxy-4-[(4-carboxy-5-hydroxy) phenyl] -1-naphthoic acid, 3-methyl-5-
(Iso) nonylsalicylic acid, 3-methyl-5- (iso)
Dodecyl salicylic acid, 3-methyl-5- (iso) pentadecyl salicylic acid, 3-methyl-5- (α-methylbenzyl) salicylic acid, 3-methyl-5- (α, α-dimethylbenzyl) salicylic acid, 3.5- Di-sec-butylsalicylic acid, 3,5-di-tert-butyl-6-methylsalicylic acid, 3-tert-butyl-5-phenylsalicylic acid,
3,5-di-tert-amylsalicylic acid, 3-cyclohexyl-5- (iso) nonylsalicylic acid, 3-phenyl-
5- (iso) nonylsalicylic acid, 3- (α-methylbenzyl) -5- (iso) nonylsalicylic acid, 3-isopropyl-5- (iso) nonylsalicylic acid, 3- (iso) nonylsalicylic acid, 3- (iso) Nonyl-5-methylsalicylic acid, 3- (iso) nonyl-5-cyclohexylsalicylic acid, 3- (iso) nonyl-5-phenylsalicylic acid, 3- (iso) nonyl-5- (α-methylbenzyl)
Salicylic acid, 3- (iso) nonyl-5- (α, α-dimethylbenzyl) salicylic acid, 3- (iso) nonyl-5-
(Α, α-Dimethylbenzyl) salicylic acid, 3- (α, α
-Dimethylbenzyl) -5- (iso) nonylsalicylic acid, 5- (iso) nonylsalicylic acid, 3- (iso) nonyl-6-methylsalicylic acid, 3-tert-butyl-5-
(Iso) nonylsalicylic acid, 3,5-di (iso) nonylsalicylic acid, 3- (iso) dodecylsalicylic acid, 3-
(Iso) dodecyl-5-methylsalicylic acid, 3- (iso) dodecyl-6-methylsalicylic acid, 3-isopropyl-5- (iso) dodecylsalicylic acid, 3- (iso) dodecyl-5-ethylsalicylic acid, 5- (iso ) Dodecyl salicylic acid, 3- (iso) pentadecyl salicylic acid, 3
-(Iso) pentadecyl-5-methylsalicylic acid, 3-
(Iso) pentadecyl-6-methylsalicylic acid, 5-
(Iso) pentadecyl salicylic acid, 3-cyclohexyl-5- (α-methylbenzyl) salicylic acid, 3-phenyl-5- (α-methylbenzyl) salicylic acid, 3- (α
-Methylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5-methylsalicylic acid, 3- (α-methylbenzyl) -6-methylsalicylic acid, 3- (α-methylbenzyl) -5-phenylsalicylic acid, 3- (Α-Methylbenzyl) -5-bromosalicylic acid, 3- (α, α-dimethylbenzyl) -5-methylsalicylic acid, 3,5-di (α, α-dimethylbenzyl) salicylic acid, 3- (α, α)
-Dimethylbenzyl) -6-methylsalicylic acid, 3,5
-Di (α, α-dimethylbenzyl) salicylic acid, 5-
(4-mesitylmethylbenzyl) salicylic acid, benzylated styrenated salicylic acid, 2-hydroxy-3- (α,
Mention may be made of polyvalent metal salts of aromatic carboxylic acids such as α-dimethylbenzyl) -1-naphthoic acid or 3-hydroxy-7- (α, α-dimethylbenzyl) -2-naphthoic acid. Specific examples of the polyvalent metal include magnesium, calcium, zinc, aluminum, iron, cobalt, nickel and the like. These may be used alone or as a mixture.

The term "(iso) alkyl" means isoalkyl or normal alkyl. Further, the isononyl group, the isododecyl group and the isopentadecyl group are preferably substituents formed by addition of propylene trimer, propylene tetramer or 1-butene trimer and propylene pentamer, respectively.

In addition to calcium carbonate, examples of the pigment include zinc oxide, magnesium oxide, titanium dioxide, aluminum hydroxide, kaolin, clay, calcined kaolin, delaminated kaolin, structured kaolin, magnesium sulfate, calcium sulfate and the like. Inorganic pigments and organic pigments (plastic pigments) such as polystyrene resin fine particles, urea formalin resin fine particles, and minute hollow particles are appropriately used within a range that does not impair the effects of the present invention.

As the binder, for example, starch, casein, gum arabic, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, styrene / butadiene copolymer latex, vinyl acetate latex and the like are blended.

The method of preparing the coating liquid for forming the color-developing sheet is not particularly limited and may be appropriately prepared. For example, a method of applying a coating liquid obtained by mechanically dispersing an organic developer together with an inorganic pigment, a binder, a dispersant and other additives in water to a support, or dissolving the developer in an organic solvent. After emulsifying in water and distilling off the organic solvent by a method such as steam distillation, a method of applying a coating liquid obtained by adding an inorganic pigment, a binder, and other additives to a support, or a mixture of both A method of applying the coating liquid on the support is used.

As the organic solvent used for emulsifying and dispersing the developer, halogenated hydrocarbons having a boiling point of 200 ° C. or less, aromatic hydrocarbons, esters, ketones, ethers, amides and nitriles are preferable. Among these, those having a solubility in water at room temperature of 5 or less are more preferable. Specific examples of the organic solvent include chloroform, methylchloroform, benzene, toluene, xylene, chlorobenzene,
Examples thereof include ethyl acetate, butyl acetate, isopropyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and dimethylacetamide.

The water-soluble polymer used for emulsification includes polyvinyl alcohol, maleic anhydride-isobutylene copolymer, carboxymethyl cellulose, hydroxyethyl cellulose, polyacrylamide, polyacrylic acid, acrylamide-alkyl acrylate copolymer, ether. Examples thereof include synthetic or natural polymers such as modified polyvinyl alcohol, polyvinylpyrrolidone, starch, casein, gum arabic and gelatin.

In the present invention, the method for preparing the developer layer coating liquid is not particularly limited. Furthermore, various auxiliary agents such as a water-proofing agent, a curing agent, a cross-linking agent, an antifoaming agent, a coloring agent, a wetting agent, a flow modifier and an antiseptic agent are appropriately added to the coating liquid for the color developing layer. It

The coating solution for the color developing sheet thus prepared is applied to a support such as paper, synthetic paper or film on which an air knife coater, a blade coater, a rod blade coater,
A color-developing sheet for pressure-sensitive copying paper can be obtained by coating with a usual coating device such as a roll coater, a bar coater, a size press coater, a bill blade coater, a curtain coater, a short dwell coater, and a bar coater.

The coating amount on the support is not particularly limited, but is 3 to 10 g / m ^{2 on} a dry basis, preferably 4 to 7 g / m ² . The color-developing sheet for pressure-sensitive copying paper thus obtained can be passed through an on or off super calender, a soft nip calender or the like for pressure smoothing finish.

[0021]

EXAMPLES Examples and comparative examples will be described below in order to further clarify the effects of the present invention, but the present invention is not limited to these. In the examples, "parts" and "%" represent "parts by weight" and "% by weight", respectively, unless otherwise specified.

Example 1 [Preparation of coating liquid for color developing layer] 10 parts of zinc salt of 3,5-di (α-methylbenzyl) salicylic acid was added to 10 parts of toluene to give 7 parts.
A toluene solution dissolved at 0 ° C. was dissolved in water containing 0.6 parts of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 98%.
The mixture was emulsified in 30 parts using a homomixer, and then toluene was distilled off by steam distillation to obtain an aqueous dispersion of fine developer particles. Add light calcium carbonate (Tamapearl T to this water dispersion)
P-121; Okutama Industrial Co., Ltd.) 90 parts, 2 of oxidatively modified starch
20 parts of 5% aqueous solution and 16 parts of styrene-butadiene copolymer latex are mixed, and further poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt]
5 parts (Fix oil R-737; manufactured by Meisei Chemical Co., Ltd.) was added to prepare a coating liquid for the color developing layer.

[Production of color developing sheet for pressure-sensitive copying paper] Basis weight 4
On the surface of the base paper of 0 g / m ^2, the coating solution for the color developing layer was applied by an air knife coater so that the dry coating amount was 6 g / m ² , and dried to obtain a color developing sheet for pressure-sensitive copying paper.

Example 2 A color developing sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1 except that 2 parts of poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt] was added. .

Example 3 Example 1 except that 10 parts of poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt] was added.
A color developing sheet for pressure-sensitive copying paper was obtained in the same manner as in.

Example 4 Poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt] (PAL-2; manufactured by Nippon Senka Kogyo)
A color developing sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1 except that 6 parts of was added.

Comparative Example 1 A color developing sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1 without adding poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt].

Comparative Example 2 A color developing sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1 except that 1 part of poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt] was added. .

Comparative Example 3 Example 1 except that 13 parts of poly [N, N-dimethyl-N- (2-hydroxypropyl) ammonium salt] was added.
A color developing sheet for pressure-sensitive copying paper was obtained in the same manner as in.

[Performance Comparison Test] The six types of pressure sensitive copying paper color developing sheets obtained as described above were subjected to an evaluation test by the following method, and the results are shown in Table 1.

(1) Pressure-sensitive copy coloring property A color developing sheet and a commercially available top paper (KS copy bright / black coloring, N-40 / Shin Oji Paper Co., Ltd.) are superposed so that their coated surfaces face each other, and a line is formed. The paper was passed through a super calendar set to a pressure of 10 kg / cm to develop color, and after 1 hour, the color density was measured with a Macbeth densitometer RD-941.

(2) Storability A color development sheet and a commercially available top paper (KS copy bright / black color development, N-40 / Shin Oji Paper Co., Ltd.) are laminated so that the coated surfaces face each other, and the linear pressure is 10 kg. Paper is passed through a super calendar set to / cm to develop color, 90% RH, 40 ° C
The color density was measured with a Macbeth densitometer RD-941 after 72 hours of storage in a constant temperature and humidity chamber.

(3) Desensitizing effect A commercially available desensitizing ink (desensitizing ink JEP6-3; manufactured by Shin Oji Paper Co., Ltd.) was used with an RI printing aptitude tester (manufactured by Akira Seisakusho) to apply the developer on the developer sheet. After printing, a commercially available top paper (KS copy bright / black color development, N-40 / manufactured by Shin Oji Paper Co., Ltd.) was overlaid so that the printed surface and the coated surface faced each other, and printed with a typewriter. The amount of ink that does not completely develop color was measured by a gravimetric method.

(4) Surface Strength A commercially available printing ink (Tack Value 13; made by Dainippon Ink) was printed three times on the developer-coated surface of the developer sheet using an RI printability tester (manufactured by Meisei Seisakusho). The state of powder falling was evaluated organoleptically according to the following five-grade evaluation criteria. "Evaluation Criteria" 5: No powder drop was observed. 4: A slight powder drop is observed. 3: Although powder falling is recognized, there is no problem in practical use. 2: Peeling off was observed, which is a practical problem. 1: Remarkable powder falloff.

[0035]

[Table 1]

[0036]

As is apparent from Table 1, the color-developing sheet for pressure-sensitive copying paper obtained in the present invention exhibits the desensitizing effect even when the desensitizing ink amount is small during desensitizing printing. In addition, it is excellent in color development and storability as a pressure-sensitive copying paper.

Claims (1)

[Claims] 1. A color-developing sheet for pressure-sensitive copying paper, comprising a support and a coating liquid containing a polyvalent metal salt of a nuclear-substituted aromatic carboxylic acid derivative and a pigment, and [N,
N-dimethyl-N- (2-hydroxypropyl) ammonium salt] in an amount of 2 to 10% by weight based on the total solid amount of the polyvalent metal salt of the nuclear-substituted aromatic carboxylic acid derivative and the pigment. Developer sheet for pressure-sensitive copying paper.