JPH04282285A - Pressure-sensitive copying sheet - Google Patents

Abstract

PURPOSE:To obtain a pressure-sensitive copying sheet which functions to cyclically repeatedly have adhesion properties and releasing properties by a method wherein a layer containing microcapsules containing a color former in a mixed state with a fine globular re-releasable adhesive is provided on a substrate. CONSTITUTION:On a substrate 4, a layer 2 containing microcapsules at least containing a color former is provided. A fine globular re-releasable adhesive is compounded in this layer 2. In this manner, a pressure-sensitive copying sheet is produced. As the color former, 3,3-bis (p-dimethyl aminophenyl)-6- dimethyl aminophthalide, 3-(p-dimethyl aminophenyl)-3-(1,2-dimethyl indol-3-yl) phthalide, and the like are concretely exemplified. As the fine globular re- releasable adhesive, an adhesive obtained by copolymerizing an acrylic acid and an itaconic acid with a methacylilate as a main component is concretely exemplified. As the substrate, wood free paper, medium-quality paper, synthetic paper, and a film are concretely exemplified.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive copying sheet capable of repeating cycles of pasting and peeling.

0002

[Prior Art] Pressure-sensitive copying sheets are made of electron-donating color formers such as crystal violet lactone and benzoylleucomethylene blue, and electron-accepting color developers such as activated clay, bentonite, phenolic resins, and polyvalent metal salts of aromatic carboxylic acids. It applies the principle of color development due to the reaction of a coloring agent. Microcapsules containing a coloring agent made by a phase separation method, an interfacial polymerization method, an in-situ method, etc. are coated on the back side of a support. A colored image can be obtained by placing a lower paper, which is formed by coating the surface of a support with a color developer, with the respective coated surfaces facing each other, and performing pressure printing on the surface of the upper paper by writing or using a typewriter or the like. If you wish to make more copies, insert the necessary number of inner sheets coated with the developer on the surface of the support and the microcapsules on the back between the upper and lower sheets. Multiple copies can be obtained. Furthermore, as a type of pressure-sensitive copying paper, there is a so-called single pressure-sensitive recording sheet in which the above-mentioned microcapsules and color developer are formed as a laminated or mixed layer.

[0003] Pressure-sensitive copying sheets have traditionally been used for documents such as product slips, but when a pressure-sensitive copying sheet is to be temporarily attached to a product, commercially available adhesives or adhesives are usually used. Since the copy sheet was attached directly to the product with tape or the like, there were drawbacks such as the copy sheet tearing when removed.

0004

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure-sensitive copying sheet that can be used repeatedly through cycles of application and removal.

[0005]

[Means for Solving the Problems] The present invention provides, on a support,
This pressure-sensitive copying sheet has a microcapsule-containing layer containing at least a coloring agent, and the microcapsule-containing layer contains a microspherical removable adhesive.

[0006]

[Function] The top paper or inner paper obtained by the present invention is produced by removing the coloring agent that reacts with the coloring agent in the coloring paper to form a color by a phase separation method.
It can be obtained by coating microcapsules encapsulated by an interfacial polymerization method, an in-situ method, etc. on a support, particularly in combination with a microsphere type removable adhesive. In addition, when using natural polymer membrane gelatin microcapsules obtained by phase separation method, the capsule membrane may collapse depending on the type of microsphere type removable adhesive used, so it is especially important to avoid Microcapsules made of a synthetic resin film produced by legal or in-situ methods are preferably used.

Coloring agents for pressure-sensitive copying paper include 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide and 3-(p-dimethylaminophenyl)-3-
(1,2-dimethylindol-3-yl)phthalide,
3,3-bis(1,2-dimethylindol-3-yl)-5-dimethylaminophthalide, 3,3-bis(9-
Ethylcarbazol-3-yl)-6-dimethylaminophthalide, 3-4-(diethylamino)-2-ethoxyphenyl-3-(2-methyl-1-octyl-3-indolyl)-4-azaphthalide, 3, Triallylmethane dyes such as 3-bis(2-methyl-1-octyl-3-indolyl)azaphthalide, 4,4'-bis-dimethylaminobenzhydrylbenzyl ether, N-halophenyl-leucoauramine, N - diphenylmethane dyes such as 2,4,5-trichlorophenylleucoolamine, thiazine dyes such as benzoylleucomethylene blue and p-nitrobenzoylleucomethylene blue, 3-methyl-spiro-dinaphthobilane, 3-phenyl-spiro-dinaphthobilane, 3-propyl-spiro-dinaphthobilane, 6'-[ethyl(3-methylbutyl)amino]-
Spiro dyes such as 3'-methyl-2'-(phenylamino)-spiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one, rhodamine-B-anilinolactam, rhodamine Lactam dyes such as (o-chloroanilino)lactam and rhodamine (o-chloroanilyl)lactam, 3-dimethylamino-7-methoxyfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-(N- ethyl-p-toluidino)
-7-methylfluorane, 3-diethylamino-7-N
-Methylaminofluorane, 3-diethylamino-7-
Dibenzylaminofluorane, 3-(N-ethyl-p-
Toluidino)-6-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-phenylaminofluorane, 3-(N-cyclohexyl-N-methylamino)-6-methyl-7-phenylamino Examples include fluoran dyes such as fluoran, 3-piperidino-methyl-7-phenylaminofluoran, and 3-diethylamino-6-methyl-7-xylidinofluoran, and mixtures thereof.

In the microcapsule-containing layer coating solution, adhesives such as polyvinyl alcohols, starches, latexes, carboxymethyl celluloses, pulp powder, raw starch powder, etc. Various materials such as a stilt agent are appropriately blended. Microspherical removable adhesives are not particularly limited, and include, for example, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, and nonyl acrylate. The main ingredients are methacrylic acid esters such as lauryl acrylate, methyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, isononyl methacrylate, and lauryl methacrylate, and these monomers are combined with acrylic acid, methacrylic acid, and itaconic acid. , crotonic acid, maleic acid, 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, N-methylol (meth)acrylamide, (meth)acrylamide, glycidyl methacrylate, cyl glycidyl ether, vinyl acetate,
Styrene, acrylonitrile, trimethylamine methacrylamide, trimethylamine-p-vinylbenzimide, ammonium acrylate, sodium acrylate, N,N-dimethyl-N-(β-methacryloxyethyl) ammonium propionate betaine, 1,1-
Dimethyl-1-(2-hydroxypropyl)amine methacrylimide, 4,4,9-trimethyl-4-azonia-7-oxy-9-decene-1-sulfonate, 1,1
It can be produced by copolymerizing monomers such as -dimethyl-1-(2,3-dihydroxypropyl)amine methacrylimide. For specific manufacturing methods, see, for example, JP-A-50-2736 and JP-A-61-14.
It can be produced by the suspension polymerization method described in No. 8278 and the like. The particle size of the microspheres is not particularly limited, but is about 10 to 100 μm, preferably about 30 to 80 μm.

The blending ratio of the capsule coating liquid and the removable microsphere adhesive is 10 to 1000 parts by weight, more preferably 50 parts by weight, based on 100 parts by weight of the capsule oil. to 500 parts by weight, most preferably from 100 parts to 300 parts by weight. Furthermore, the method for forming the layer containing the microcapsule-containing coating liquid and the microsphere-type removable adhesive on the support is not particularly limited; A mixed layer is applied and dried to form a microcapsule-containing layer. High-quality paper as a support;
Medium-quality paper, coated paper such as cast paper, art paper, coated paper, synthetic paper, film, etc. are used.

FIGS. 1 and 2 illustrate examples of top paper and middle paper, respectively. In both examples, the microcapsule-containing layer (2)
describes a case in which a microspherical removable adhesive and microcapsules are included as a mixed layer. In FIG. 2, a coloring agent-containing layer (3) is provided on the surface. The coating amount of the microcapsule-containing layer is about 2 g/m2 to 50 g/m2, preferably 5 g/m2.
g/m2 to 40 g/m2, most preferably 7 g/m2
to about 30 g/m2.

[0011]

EXAMPLES Examples of pressure-sensitive copying sheets according to the present invention will be described below. Note that the present invention is not limited to these Examples. Incidentally, parts and % indicate parts by weight and % by weight unless otherwise specified.

Example 1 [Preparation of upper paper] (Preparation of capsule dispersion) 15 mol% of vinyl sulfonic acid
, a 20% aqueous solution (2
5℃, ph2, concentration 20%, viscosity 50cps) 37.5
112.5 parts of water was added to 1 part, and 20% NaOH aqueous solution was added.
The aqueous medium for capsule production was prepared by adjusting h to 4.6. Diisopropylnaphthalene (manufactured by Kureha Chemical Co., Ltd.) in which 5 parts of crystal violet lactone was dissolved.
After adding 105 parts of "K-113") and emulsifying and dispersing it so that the average particle size was 5 μ, the temperature of the emulsion was raised to 70°C.

Next, 20 parts of a methylated methylolmelamine initial condensate (manufactured by Dainippon Ink Chemical Co., Ltd., "Beccamin APM" 80% concentration) was added to the system, and the temperature was maintained at 70° C. for 1 hour while maintaining stirring. After being held, it was cooled to obtain a milky white capsule dispersion. Next, 70 parts of wheat starch, 20 parts of dissolved oxidized starch (solid content), and microspherical removable adhesive (manufactured by Toyo Ink Co., Ltd., "BPW-5358" 40% concentration) 2
00 parts was added to prepare a microcapsule-containing coating liquid.

This coating liquid was applied to a 40 g/m 2 base paper using an air knife coater so that the dry coating amount was 10 g/m 2 and dried to obtain a top paper.

Example 2 "Preparation of inner paper" (Preparation of developer coating solution) 65 parts of aluminum hydroxide, 20 parts of zinc oxide, zinc 3,5-di(α-methylbenzyl)salicylate and α-methylstyrene. - A dispersion obtained by grinding 15 parts of a mixed melt with a styrene copolymer (melt ratio 80/20), 5 parts of an aqueous polyvinyl alcohol solution (solid content) and 300 parts of water in a ball mill for 24 hours was subjected to carboxy modification. Styrene-butadiene copolymer latex 20 parts (solid content)
was added to obtain a developer coating solution.

[0016] This coating liquid was applied to a 40 g/m2 base paper using an air knife coater so that the dry coating amount was 5 g/m2, dried, passed through a super calendar for smoothing treatment, and then applied to the back side. The microcapsule-containing layer coating liquid used in Example 1 was coated with an air knife coater so that the dry coating amount was 10 g/m 2 and dried to obtain an inner paper.

The top paper of Example 1, the middle paper of Example 2, and the commercially available bottom paper (manufactured by Kanzaki Paper Industries) thus obtained were finished into forms and printed on a typewriter, and excellent records were obtained. Furthermore, the pressure-sensitive copying sheets of Examples 1 and 2 had adhesive properties and could be repeatedly pasted and peeled off.

[0018]

[Effects of the Invention] The pressure-sensitive copying sheet according to the present invention is commercially available when used for documents such as product slips, or when used for temporarily pasting copied pressure-sensitive copying sheets on products. There is no need to use adhesive glue or adhesive tape. Furthermore, the sheet does not tear when removed. Therefore, the effects are extremely great for those who handle forms, such as improving work efficiency and administrative efficiency.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view illustrating a pressure-sensitive copying sheet (upper sheet) according to the present invention.

FIG. 2 is a cross-sectional view illustrating a pressure-sensitive copying sheet (inner sheet) according to the present invention.

[Explanation of symbols]

1 Pressure-sensitive copy sheet 2. Microcapsule-containing layer 3 Coloring agent-containing layer 4 Support

Claims (1)

[Claims] Claim 1: A pressure-sensitive copying sheet having a microcapsule-containing layer containing at least a coloring agent formed on a support, wherein the microcapsule-containing layer contains a microspherical removable adhesive.