JPH04163186A - Pressure-sensitive copy sheet - Google Patents

Abstract

PURPOSE:To obtain pressure sensitive sheets which have an excellent color developing and anti-abrasive fouling properties when produced by means of printing method and an excellent multiple-sheet duplicable and anti-abrasive fouling properties when produced by means of coating method, by a method wherein capsules containing oil and particles as stilt agent having a larger diameter than the average diameter of the oil capsules are contained in a color developer layer of a receptive sheet. CONSTITUTION:Coating liquid used for forming a color developer layer is usually an aqueous liquid, and color developer, oil capsules, fine particles as stilt agent having a larger diameter than the average diameter of the capsules, binder, and, if required, various auxiliary agents such as white pigment, dispersant, anti-foaming agent, antiseptic agent, fluorescent whitener, ultraviolet light absorber, anti-oxidizing agent, colored dye, etc., are added and mixed into water under agitation to prepare coating liquid. Pulp powder is preferably used as the fine particles as stilt agent which are contained in the color developer layer together with the oil capsules because it is effective in improving the anti-abrasive fouling property. The pulp powder having an average diameter range of 20-200mum is especially preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pressure-sensitive copying sheet, and more particularly to an improvement in a receptor sheet having a color developer layer provided on a support.

[Conventional technology]

A combination of an electron-donating color former such as crystal violet lactone or benzoyl leucomethylene blue and an electron-accepting color developer such as activated clay, a phenol-formaldehyde condensate, or a polyvalent metal salt of an aromatic carboxylic acid, or nickel carboxylate. Color is produced by the reaction of various chromogen substances, such as combinations of salts and metal salts such as N, N-di-benzyl-dithio-oxide, organic iron phosphate salts and lauryl gallate, and ligand compounds. Pressure sensitive copying sheets utilizing this principle are well known.

In general, such pressure-sensitive copying sheets are made by coating a support with microcapsules containing a chromogen substance prepared by a phase separation method, an interfacial polymerization method, an 1n-situ method, etc.
), a base paper (CF) in which the support is coated with another chromogen substance that reacts with the above chromogen substance to develop color, and the above microcapsules and the chromogen substance are coated on separate sides of the support. It is put into practical use by appropriately combining medium paper (CFB).

In addition, there is also a so-called single pressure-sensitive copying sheet in which the above-mentioned microcapsules and chromogen material are coated as a laminated or mixed layer on the same side of a support, and a capsule layer is further coated on the back side of the single pressure-sensitive copying sheet. There is also a stand-alone pressure-sensitive copying set in which the above-mentioned lower paper and inner paper are appropriately combined.

However, the capsule layer of such a pressure-sensitive copying sheet is usually provided by applying an aqueous capsule coating liquid to a support using a large coating machine (hereinafter, this method is referred to as a coating method), Alternatively, capsules can be made into ink and applied using a printing machine (hereinafter, this method is referred to as the printing method), but the quality of the products obtained by either method is still far from satisfactory. has. For example, in the case of the printing method, expensive capsules can be printed only on the necessary parts of the support, so it is more economical than the coating method that coats the entire surface of the support, and it is also more flexible and allows for small-lot, high-mix production. Although it has the advantage of being able to be used as a coating method, it is inferior to that obtained by coating methods in terms of quality such as color development.
The reality is that it has hardly been put into practical use at this stage. In order to solve the problem that the color development of pressure-sensitive copying sheets obtained by printing methods is poor, the inventors of the present invention previously proposed in Japanese Patent Application Laid-open No. 177280/1983 that a color developer layer was used in the color developer layer. Although it is stated that the method of containing encapsulated oil is effective, as a result of further investigation,
It has been found that although this method can significantly improve color development, there is a practical problem in that friction stain resistance decreases. In addition, in the case of pressure-sensitive copying sheets obtained by the coating method, all sheets show relatively good color development when the number of copies is 2 to 4, but if you try to make more copies than this, the number of copies below 5 There is a problem that the recording on the sheet becomes unclear. Furthermore, in order to deal with this problem, a method of incorporating oil into the color developer layer is also known. However, if this known method is used to improve the color development of the color developing layer, there is a problem in that color development stains due to friction become more noticeable.

[Problem to be solved by the invention]

The pressure-sensitive copying sheet of the present invention has excellent color development and friction stain resistance when manufactured by a printing method, and has excellent multi-sheet copyability and friction stain resistance when manufactured by a coating method. The purpose is to provide a pressure-sensitive copying sheet.

[Means to solve the problem]

As a result of studies, the present inventors found that by incorporating fine particles of a specific size into the color developer layer containing the oil capsules to protect the oil capsules from destruction, the friction of the receptor sheet that caused colored stains to become more noticeable. They discovered that stains can be improved and completed the present invention.

The present invention provides a pressure-sensitive copying sheet that combines a transfer sheet in which a support is provided with a capsule layer containing oil in which a color forming agent is dissolved, and a receptor sheet in which a color developer layer is provided in a support. This is a pressure-sensitive copying sheet characterized by containing capsules containing oil in the color developer layer and fine particles having a larger average particle diameter than the oil capsules as a stilting agent.

[Effect]

Generally, the coloring agent includes an electron-donating coloring agent.
Further, the color developer includes an electron-accepting color developer, but the present invention is not limited to this, and there are also cases where a color former and a color developer are used, or a chelate diameter recording material is used. included.

Examples of the electron-donating coloring agent used in the present invention include the following substances known in the field of pressure-sensitive copying paper.

3.3-bis(p-dimethylaminophenyl)-3-(
1,2-dimethylindol-3-yl)phthalide, 3
,3-bis(l,2-dimethylindol-3-yl)
-5-dimethylaminophthalide, 3,3-bis(9-ethylcarbazol-3-yl)-6-dimethylaminophthalide and other triallylmethane dyes, 4,4'-bis-dimethylaminobenzhydryl benzyl ether, N
-2゜4.5-diphenylmethane dyes such as chlorophenyl leuco auramine, thiazine dyes such as hendiyl leucomethylene blue and p-nitrohendiyl leucomethylene blue, spiro dyes such as 3-methyl-spiro dihenzobilane, Lactam dyes such as rhodamine-B-anilinolactam, rhodamine (p-nitroanilino) lactam, rhodamine (O-chloroanilino) lactam, 3-dimethylamino-7-medoxyfluoran,
3-diethylamino-6-methyl-7-chlorofluorane, 3-(N-ethyl-p-toluidino)nia-methylfluorane, 3-diethylamino-7-N-methylaminofluorane, 3-diethylamino-7- dibenzylaminofluorane, 3-(N-ethyl-P-)luidino)
-6-Methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-phenylaminofluorane, 3-(N-cyclohexyl-N-methylamino)
Fluoran dyes such as -6-methyl-7-phenylaminofluorane, 3-piperidino-6-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-xylidinofluorane, etc., and these Mixtures may be mentioned.

Examples of the electron-accepting color developer include the following substances known in the field of pressure-sensitive copying paper.

Acid clay, activated clay, attapulgite, zeolite,
Clays such as bentonite, phenolic resin, special public interest
Examples thereof include polyvalent metal salts of various aromatic carboxylic acids as described in No. 1-25174, zinc salts of 2,2'-bisphenolsulfone compounds as described in JP-A-54-106316, and mixtures thereof.

Examples of chelate-based recording materials include the following combinations of substances known in the field of pressure-sensitive copying paper.

Nickel stearate and N, N-benzyloodithiooxamide, nickel laurate and α-benzylglyoxime, tricaprylmethylammonium vanadate and dodecylamine 8-hydroxyquinolinesulfonate, benzyllauryldimethylammonium molybdate and lauryl protocatechuate, titanium stearate and lauryl gallate, iron naphthenate and hensyl gallate, polyferrophenylmethylsiloxane and methylene bissus (8-oxyquinoline), copper valmitate and N,
N'-bis-2-octanoyloxyethyldiethyldithiooxide, cobalt laurate and di-o
Examples include combinations of -tolylguanidine, hinokitiol and polyhanadophenylmethylsiloxane, organic iron phosphate and lauryl gallate described in JP-A-58-38191, and mixtures thereof.

In the receiving sheet constituting the present invention, the coating liquid used to form the color developer layer is usually an aqueous system, in which water contains a color developer, an oil capsule, fine particles larger than the average particle diameter of the oil capsule as a stilt agent, and Prepared by adding and mixing a binder and various auxiliaries such as white pigments, dispersants, antifoaming agents, preservatives, optical brighteners, ultraviolet absorbers, antioxidants, and colored dyes under stirring as necessary. be done. The color developer and white pigment are used after being pulverized using a ball mill, attritor, sand mill, etc., if necessary.

Examples of oils used in oil capsules include the following substances that are commonly used to dissolve color formers in pressure-sensitive copying paper.

Vegetable oils such as cottonseed oil; Mineral oils such as kerosene, valefin, naphthenic oil, and chlorinated paraffin; alkylated biphenyls, alkylated terphenyls, alkylated naphthalenes,
Aromatic hydrocarbons such as diarylethane, triarylmethane, diphenylalkane, dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, dioctyl phthalate, diethyl adipate, propyl adipate, di-n-butyl adipate, Esters such as dioctyl adipate and mixtures thereof.

As a method for encapsulating oil, conventionally known coacervation methods, interfacial polymerization methods, 1n-situ methods, etc. can be selected and used as appropriate, but among them, melamine-formaldehyde resins and urethane resins obtained by 1n-situ methods can be used. Capsules having a wall made of urea resin are particularly preferred because they have extremely good color development and the receptor layer is difficult to deteriorate over time. In addition, the particle size of the capsule is 1 to 10
Those in the μm range are particularly preferred in terms of the balance between color development and stain resistance.

The oil in the oil capsule added to the color developer layer can contain an antioxidant, an ultraviolet absorber, etc. as necessary, and a color developer can also be added. However, the addition of the color developer should be limited to an amount that does not pose the risk of staining the capsule ink layer.

Fine particles as a stilt agent to be included in the color developer layer together with oil capsules include, for example, starches such as wheat starch, rice starch, and corn starch: pulp powder: polystyrene particles, polyolefin particles, penzoganamine particles, melamine resin particles, urea resin Target particles include synthetic resin particles such as phenol resin particles and silicone resin particles, inorganic particles such as Nijirikapaloon, and those having an average particle diameter of 7 to 1000 μm. Among these, pulp powder is particularly preferred in terms of its effect on improving friction stain resistance. Especially,
Particularly preferred are those having an average particle diameter of 20 to 200 μm. Incidentally, if it is 7 μm or less, the effect as a tilt is poor, and if it is 1000 μm or more, it is too coarse and the surface of the color developer layer becomes too rough.

White pigments include silica, kaolin, calcined kaolin,
Examples include satin white, heavy calcium carbonate, light calcium carbonate, magnesium carbonate, calcium phosphate, calcium sulfate, aluminum hydroxide, zinc oxide, and titanium oxide.

As the binder, a water-soluble polymer compound or latex is used, and examples of the water-soluble polymer compounds include gelatin, albumin, casein, cereal starch, pregelatinized starch, oxidized starch, etherified starch, esterified starch, carboxymethyl cellulose, hydroxyethylcellulose, agar,
Water-soluble natural polymer compounds such as sodium alginate and gum arabic, polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, polyacrylamide, vinyl acetate-maleic anhydride copolymer, ethylene-maleic anhydride copolymer, or styrene-anhydride Examples include water-soluble synthetic polymer compounds such as alkali salts or ammonium salts of maleic anhydride copolymers such as maleic acid copolymers. Examples of the latex include styrene-butadiene latex, acrylic acid ester latex, vinyl acetate latex, acrylonitrile-butadiene latex, methyl methacrylate-butadiene latex, and carboxy-modified (e.g., acrylic acid) latex thereof. .

The amount of each component added to the developer layer is not particularly limited, but usually the developer is 1 to 90 parts by weight per 100 parts by weight of the solid content of the developer layer forming coating solution. , preferably 3~
50 parts by weight, oil capsules are 0.5 to 50 parts by weight, preferably 3 to 50 parts by weight, and the average particle size is 7 to 1000 μm.
1 to 50 parts by weight of fine particles in the range of m, preferably 3 to 3 parts by weight.
0 parts by weight, 0 to 80 parts by weight of white pigment, preferably 0 to 80 parts by weight
60 parts by weight, and the binder is 5 to 40 parts by weight, preferably 10 to 30 parts by weight.

The aqueous developer layer-forming coating solution thus prepared is applied to a support such as paper, synthetic paper, film, etc. using various known coating equipment such as an air knife coater, roll coater, bar coater, blade coater, or curtain coater. applied on top. The coating amount is usually 1 to 15 g/m in terms of dry weight.
2, preferably 2 to Log/m2.

Incidentally, the color developer layer of the present invention is usually formed using an aqueous coating liquid using a coating machine as described above, but in special cases, the aqueous coating liquid is formed by non-coating using a method such as flexography or gravure. It can also be formed by preparing an aqueous coating liquid and coating or printing.

In the transfer sheet constituting the present invention, the oil used in preparing the oil capsule is used as the oil for dissolving the coloring agent. 2 per 100 parts by weight of regular oil
The core material obtained by dissolving ~100 parts by weight of the coloring agent is encapsulated by the encapsulation method described for the preparation of oil capsules, especially consisting of a melamine-formalin resin film obtained by the 1n-situ method. Capsules are particularly suitable for making into ink because they have good solvent resistance and can be easily powdered.

The average particle diameter of the capsules varies depending on the membrane material or membrane thickness used and cannot be unconditionally determined, but it is usually 1 to 10 μm. Furthermore, the capsule may contain an antioxidant and an ultraviolet absorber, if necessary.

The coating liquid using the coating machine is the aqueous capsule dispersion prepared by the above method, and if necessary, the above-mentioned water-soluble polymer compound, latex, white pigment, stilt scraping, dispersant,
It is prepared by adding and mixing various auxiliaries known in the art such as defoaming agents, preservatives, optical brighteners, ultraviolet absorbers, antioxidants, and thickeners under stirring.

The capsule content in the capsule coating liquid is usually adjusted within the range of 20 to 90 parts by weight per 100 parts by weight of the coating liquid.

The prepared capsule coating liquid is coated with the color developer on a support such as paper, synthetic paper, film, etc. using various coating methods such as an air knife coater, bar coater, roll coater, Clavier coater, or curtain coater. Usually 1 to 10 g/s2, preferably 2 to 6 g/s2, on the back side of the coated sheet.
-2 is applied.

When the prepared aqueous capsule dispersion is made into an ink, it can be filtered and left in a semi-dry state, or it can be dried through air drying, surface drying, fluidized drying, flash drying, spray drying, vacuum drying, freeze drying, infrared drying, It is processed by high frequency drying, ultrasonic drying, pulverization drying, etc. and dispersed in a dry state in a non-aqueous ink medium to become capsule ink. In addition, as described in JP-A No. 53-135718, after mixing an aqueous capsule dispersion and a non-aqueous medium, water is removed under reduced pressure, or after filtering a capsule dispersion, a non-aqueous medium that is miscible with water is used. Capsule ink can also be prepared by washing and replacing with water.

Ink media used in the capsule ink in the present invention include various media known in the ink industry, such as volatile media in the case of evaporative drying ink, waxes in the case of hot melt ink, and ultraviolet curing In the case of ink, metal compounds having one or more vinyl groups or vinylidene groups in the molecule are used, and in the case of oxidative polymerization type ink, oils are used.

Volatile media include Hensen, toluene, xylene,
Examples include cyclohexane, hexane, ligroin, methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, etc., especially when printing. From this point of view, ethanol is preferable.

When the above-mentioned volatile medium is used, it is usually a resin for fixing the capsule to the support or a compound having one or more vinyl groups or vinylidene groups in the molecule (in this case, an ultraviolet irradiation device is used). ) is used.

Examples of the resin include polyvinyl acetate, vinyl chloride, vinyl chloride/vinyl acetate copolymer, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, and isobutylene. -Maleic anhydride copolymer, modified polyvinyl alcohol, polyvinyl butyral, polyvinylpyrrolidone, ethylcellulose, nitrocellulose, hydroxypropylcellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like.

Examples of compounds having one or more vinyl groups or vinylidene groups in the molecule include polyols, polyamines, or amino alcohols having acryloyl groups, methacryloyl groups, allyl groups, unsaturated polyesters, vinyloxy groups, acrylamide groups, etc., and unsaturated carboxylic acids. and a reaction product of an acrylate or methacrylate having a hydroxyl group with a polyisocyanate.

Typical compounds include, for example, polyethylene glycol diacrylate, propylene glycol dimethacrylate, pentaerythritol triacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, hexanediol diacrylate, 1.2
-Butanediol diacrylate, reaction product of epoxy resin and acrylic acid, reaction product of pentaerythritol and methacrylic acid, reaction product with acrylic acid, reaction product of diethylene glycol and maleic acid, acrylic acid, methyl methacrylate, butyl methacrylate, styrene, etc. Can be mentioned.

When using the above compounds, it is necessary to add a photopolymerization initiator at the same time, such as benzoquinone, phenanthrenequinone, naphthoquinone, diisopropylphenanthrenequinone, benzoisobutyl ether, benzoin, furoinbutyl ether, Michler's ketone, Aromatic ketones such as Michler's thioketone, fluorenone, trinitrofluorenone, β-benzoylaminonaphthalene,
Examples include quinone compounds, ether compounds, and nitro compounds. Examples of waxes used as media for true melt ink include beeswax, spermaceti, lanolin, candelilla wax, carnauba wax, wood wax, rice wax, montan wax,
Osikelite 1, paraffin wax, microcrystalline wax, montan wax derivative, paraffin wax derivative, microcrystalline wax derivative, castor wax, opal wax, low molecular weight polyethylene, distearyl ketone, caprylic acid amide,
Examples include stearamide, ethylene bisstearamide, stearic acid, hehenic acid, stearyl alcohol, distearyl phosphate, and the like, and these may be used alone or in combination.

Among these, those having a penetration hardness of 0.1 to 30, a melting point of 50 to 160''C, and a melting point range of less than 20''C are preferably used. In the case of hot-melt ink, aromatic hydrocarbon compounds, resins, etc. may be added in addition to the above-mentioned wax as necessary.

Examples of oils used as media for oxidative polymerization inks include vegetable oils such as linseed oil, safflower oil, soybean oil, and castor oil; processed oils such as dehydrated castor oil, polymerized oils, maleated oils, vinyl oils, and urethane oils; Oil: Examples include mineral oils such as machine oil and spindle oil.

In the case of oxidative polymerization type ink, in addition to the above oils, solvents, wax, dryers, thickeners, gelling agents,
A thixotropic agent and the like are added.

As a medium for the ultraviolet curable ink, a compound having one or more vinyl groups or vinylidene groups in the molecule as described above is used, and a photopolymerization initiator as described above is used to cure this.

Incidentally, the above-mentioned volatile medium can be added to this ink within a range that does not cause curing failure upon irradiation with ultraviolet rays.

The evaporative drying ink, hot melt ink, ultraviolet curing ink, and oxidative polymerization ink that can be used in the present invention may optionally contain capsule protectants such as cellulose powder, starch particles, synthetic resin particles, desensitizers, etc. Desensitizing components for color development, white pigments such as those mentioned above, ultraviolet absorbers, antioxidants, optical brighteners, plasticizers, colored dyes, etc. can be added.

The capsule content in capsule ink is usually 10
It is adjusted to a range of 5 to 80 parts by weight relative to 0 parts by weight.

Further, the content of the ink medium is usually adjusted to a range of 30 to 95 parts by weight per 100 parts by weight of the ink.

The prepared capsule ink is printed on a support such as paper, synthetic paper, or film, or on the back side of a sheet coated with the developer layer on the support using various printing methods such as flexo, letterpress, offset, gravure, and screen. be done.

The coating amount of the capsule ink is usually 1 to 10 g/m'', preferably 2 to 6 g/m''.

- "Examples" In order to make the effects of the present invention even clearer, Examples and Comparative Examples are listed below, but the present invention is not limited to these Examples.

In addition, unless otherwise specified, parts and % in the examples represent parts by weight and % by weight, respectively.

Example 1 (Preparation of Capsule Ink) 28 parts of Crystal High Olene Tract was heated and dissolved in 100 parts of alkyldiphenylethane (trade name: Hysol 5AS-296, manufactured by Nippon Petrochemical Co., Ltd.) to obtain an internal phase oil. Subsequently, the internal phase oil was emulsified in 200 parts of a 3% aqueous solution of ethylene-maleic anhydride copolymer (trade name: EMA-31, manufactured by Monsando Co., Ltd.) whose pH was adjusted to 6.0. The temperature was raised to °C. Separately, 15 parts of melamine was added to 45 parts of a 37% formaldehyde aqueous solution and reacted at 60° C. for 15 minutes to prepare a prepolymer aqueous solution.

This prepolymer aqueous solution was added dropwise to the emulsion, and while stirring, the prepolymer solution was added dropwise. Add 1N hydrochloric acid dropwise to adjust the pH to 5.
After setting the temperature to 3, the system was heated to 80°C and stirred for 1 hour.
Subsequently, 0.2N hydrochloric acid was added dropwise to lower the pH to 3.5, and after further stirring for 3 hours, the average particle size was reduced to 3.5.
A dispersion of 0 μm capsules was obtained.

Next, this dispersion was filter-pressed and then air-dried to form powder capsules. 100 parts of the capsules were dispersed in 300 parts of ethanol, and an ultraviolet curable resin containing a photopolymerization initiator (trade name: Grandi) was dispersed in 300 parts of ethanol. KS, manufactured by Dainippon Ink Co., Ltd.) 10 (1 and 20 parts of cellulose powder and KS
A capsule ink was prepared by adding and mixing 10 parts of a brightening desensitizer.

(Preparation of upper paper) After flexographically printing the above capsule ink on a 40 g/m'' base paper, the ink was cured with an ultraviolet irradiation device to obtain a spot printed matter with an ink amount of 3 g/m''.

(Preparation of oil-containing capsule) An internal phase oil was obtained by heating and dissolving in 100 parts of alkyldiphenylethane. Subsequently, ethylene-adjusted to pH 6.0
After the internal phase oil was emulsified in 200 parts of a 3% aqueous solution of maleic anhydride copolymer (trade name EMA-31, manufactured by Monsando), the temperature of this system was raised to 55°C.

Separately, 15 parts of melamine was added to 45 parts of a 37% formaldehyde aqueous solution and reacted at 60°C for 15 minutes to prepare a prepolymer aqueous solution.

This prepolymer aqueous solution was added dropwise to the emulsion, and while stirring, the prepolymer solution was added dropwise. After dropping IN hydrochloric acid to bring the pH to 5.3, the system was heated to 80°C and stirred for 1 hour, followed by dropwise addition of 0.2N hydrochloric acid to lower the pH to 4.0. After stirring for an additional 3 hours, it was cooled until the average particle size was 5.0μ.
A dispersion of capsules of m was obtained.

(Creating the bottom sheet) 65 parts of light calcium carbonate, 20 parts of zinc oxide, 3.5-
Mixture of zinc di(α-methylbenzyl)salicylate and α-methylstyrene-styrene copolymer (melt ratio 80/
20) Disperse 15 parts of the above oil-encapsulated capsules, 20 parts of the above oil-encapsulated capsules, and 10 parts of pulp powder (trade name Apocel, average particle size approximately 70 μm, manufactured by Rintenmeyer) in 300 parts of a 0.2% polyvinyl alcohol aqueous solution, and further disperse carboxy-modified styrene. - Apply a color developer coating solution prepared by adding 20 parts (solid content) of butadiene latex to a 40 g/m" base paper using an air knife coater so that the dry weight is 5 g/m" to coat the bottom paper. Obtained.

(Evaluation) When the thus obtained upper paper and lower paper were stacked and their surfaces were rubbed, almost no stains were generated on the lower paper surface.

Also, the typewriter printing on this copy paper was clear.

Comparative Example 1 (Preparation of lower paper) A lower paper was prepared in the same manner as in Example 1, except that Apocel was not added when preparing the developer coating liquid.

(Evaluation) A combination of the upper paper obtained in the same manner as in Example 1 and the lower paper mentioned above produced vivid color when used with a typewriter, but there was a level of problem on the lower paper surface when the surfaces of the lower paper were rubbed. Significant staining occurred.

Example 2 (Preparation of lower paper) The same procedure was carried out except that 10 parts of starch particles (trade name: Glico B, average particle diameter of about 20 μm, manufactured by Glico ■) were added instead of 10 parts of Apocel when preparing the color developer coating liquid. A lower paper was prepared in the same manner as in Example 1.

(Evaluation) The upper paper obtained in the same manner as in Example 1 and the lower paper mentioned above were stacked and the surfaces were rubbed. Although the stains generated on the lower paper surface were slightly worse than in Example 1, they were at a level that would pose no problem in practical use. It belonged to Also, the typewriter printing on this copy paper was clear.

Example 3 (Preparation of capsule ink) 100 parts of powder capsules prepared in the same manner as in Example 1 were mixed with 300 parts of an ultraviolet curable resin containing a photopolymerization initiator (trade name: Grandik, manufactured by Dainippon Ink Co., Ltd.). A capsule ink was prepared by adding and mixing 5 parts of cellulose powder and 10 parts of a desensitizer for KS Bright.

(Creation of top paper) After letterpress printing the above capsule ink on a base paper of 40 g/m2, the ink was cured with an ultraviolet irradiation device to obtain a spot print with an ink amount of 3 g/m (evaluation) Implementation with the above top paper The bottom paper obtained in the same manner as in Example 1 was stacked and the surface was rubbed, but almost no stains were generated on the bottom paper surface.

Also, the typewriter printing on this copy paper was clear.

Comparative Example 2 (Evaluation) A combination of the top paper obtained in the same manner as in Example 3 and the bottom paper obtained in the same manner as in Comparative Example 1 developed vivid colors with a typewriter, but the surfaces of each other were rubbed. In some cases, significant staining occurred on the bottom paper surface.

Example 4 (Preparation of inner paper) To the aqueous capsule dispersion prepared in the same manner as in Example 1,
A coating solution prepared by adding 30 parts (solid content) of carboxy-modified styrene-butadiene latex and 30 parts of starch particles was applied to the base paper surface of the lower paper prepared in the same manner as in Example 1, with a dry weight of 4 g/rrr. The paper was coated with an air knife coater to obtain a medium paper.

(Evaluation) Eight sheets of the thus obtained inner sheets were stacked and printed using a typewriter. As a result, the copy of the eighth sheet was clear and the sheets were also excellent in friction stain resistance.

Comparative Example 3 (Preparation of lower paper) A lower paper was produced in the same manner as in Example 1, except that oil-encapsulated capsules and pulp powder were not added in preparing the color developer coating solution.

(Creation of inner paper) The aqueous capsule dispersion prepared in the same manner as in Example 4 was
The base paper surface of the bottom paper was coated with an air knife coater so that the dry weight was 4 g/bot to obtain an inner paper.

(Evaluation) As a result of printing 8 sheets of the thus obtained inner sheets with a typewriter, the copy of the 8th sheet was unclear and unreadable.

"Effects" The pressure-sensitive copying sheet of the present invention has excellent color development and friction stain resistance when manufactured by a printing method, and has excellent multi-copying properties and resistance when manufactured by a coating method. It had friction staining properties and was excellent in practicality.

Claims (4)

[Claims] (1) In a pressure-sensitive copying sheet that combines a transfer sheet in which a support is provided with a capsule layer containing oil in which a color former is dissolved, and a reception sheet in which a color developer layer is provided in a support, the reception sheet is A pressure-sensitive copying sheet characterized in that a developer layer contains capsules containing oil and fine particles as a stilting agent that are larger in diameter than the average particle diameter of the oil capsules. (2) The pressure-sensitive copying sheet according to claim (1), wherein the capsule layer containing oil in which a coloring agent is dissolved is provided by printing with capsule ink. (3) Claim (1) wherein the fine particles are pulp powder.
The pressure-sensitive copying sheet described in (2) to (2) above. (4) The average particle diameter of the pulp powder is 20 to 200
The pressure-sensitive copying sheet according to claim 3, wherein the pressure-sensitive copying sheet has a range of .mu.m.