JPH0418389A - Pressure-sensitive copying sheet - Google Patents

Abstract

PURPOSE:To prevent the generation of unnecessary developed color contamination on a capsule ink printing part after recording by partially printing the developer layer of a developing sheet with one kind of a capsule ink composition. CONSTITUTION:A developer layer 3 is provided on a support 2 to form a developing sheet and a capsule ink composition 4 containing a color former-including microcapsule and a desensitizing component as fundamental components is partial printed on the coupler layer of the developing sheet. In this case, as the sensitizing agent, any component preventing the reaction of the color former with the developer can be used and, concretely, a quaternary ammonium salt is used and, as the color former, an electron donating color former is used and 3, 3-bis(p-dimethylaminophenyl)-6-dimethylphthalide is designated. As the developer, an electron acceptive developer is used and clays such as acid clay, activated clay, attapulgite, zeolite or bentonite are designated.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a pressure-sensitive copying sheet, and particularly a pressure-sensitive copying sheet in which a color former-containing microcapsule layer and a color developer layer are provided at different locations on the same surface of a support. Concerning improvements in compression copying sheets.

"Prior art" Combination of electron-donating color formers such as crystal bioleft lactone and benzoyl leucomethylene blue with electron-donating color formers such as activated clay, phenol-formaldehyde condensates, and polyvalent metal salts of aromatic carboxylic acids. Pressure-sensitive copying sheets that utilize the color reaction of two types of chromogen substances are well known.

In general, these pressure-sensitive copying sheets are sheets in which color former-containing microcapsules prepared by a phase separation method, interfacial polymerization method, 1n-situ polymerization method, etc. A base sheet coated on the body and a middle sheet coated with the above-mentioned color forming agent-containing microcapsules and a color developer coated on separate sides of a support are used in appropriate combinations to be put into practice in various fields.

In special cases, a sheet in which the color former-containing microcapsule layer and the color developer layer are provided at different locations on the same side of the support is folded and used as a slip with the microcapsule layer and the color developer layer facing each other. There are cases.

In general, such a sheet can be obtained by: (1) Spot-printing an ink containing microcapsules containing a color former and an ink containing a color developer on different locations on the same surface of a support.

■ A method of spot printing an ink containing color former-containing microcapsules on a portion of the color developer layer of a base sheet in which a color developer layer is provided on the entire surface of the support.

(2) A method of spot printing a color developer-containing ink on a portion of the capsule layer of an upper sheet in which a color former-containing microcapsule layer is provided on the entire surface of the support.

etc. are valid.

However, method (2) requires a special printing machine to print both the ink containing microcapsules containing a color former and the ink containing a color developer. They tend to be inferior in color development compared to pressure-sensitive copying sheets.

In addition, in the methods ``■'' and ``■'', a general-purpose printing machine that can print with one type of ink can be used, and the color development is also relatively good, but the printed part consists of a color former-containing microcapsule layer and a color developer layer. Since it is a laminated self-coloring type, it has the disadvantage of being easily stained.

For this reason, for example, a method has been proposed in which a barrier layer is printed in advance on a part of the color former-containing microcapsule layer and an ink containing a color developer is printed on it, but as a result, the barrier layer Since it is necessary to print two types of ink, a layer-forming ink and a developer-containing ink, a special printing machine is required.

``Problems to be Solved by the Invention'' The present invention solves the above-mentioned drawbacks of the prior art, and in particular, develops color on the color developer layer of a color developer sheet in which a color developer layer is provided on a support. This method prevents the self-coloring performance of the printed portion, which is exhibited by pressure-sensitive copying sheets that are partially printed with ink containing agent-encapsulated microcapsules, and as a result, a desired pressure-sensitive copying sheet with excellent quality can be obtained. be.

"Means for Solving the Problems" The present invention provides capsules containing a color former-containing microcapsule and a desensitizing component as basic components on the developer layer of a color developer sheet in which a color developer layer is provided on a support. This is a pressure-sensitive copying sheet that is partially printed with an ink composition.

"Function" In the pressure-sensitive copying sheet of the present invention, a capsule ink composition containing color former-containing microcapsules and a desensitizing component as basic components is partially printed on the developer layer of the color developer sheet. As the sensitive component, any component can be used as long as it inhibits the reaction between the color former and the color developer. Specifically, quaternary ammonium salts [Japanese Patent Publication No. 33-3921], tertiary amines having two polyethyleneoxy groups [Japanese Patent Publication No. 46-29546], and initial condensates of urea resins [Japanese Patent Publication No. 46-1986] -35697], polyethyleneoxymonoalkyl ether [Japanese Patent Publication No. 47-38201], ethylene oxide addition compound of polyalkylene polyamine [Japanese Patent Publication No. 49-23008], propylene oxide addition compound of alkylene diamine [Japanese Patent Publication No. 49-2385]
0], polypropylene glycol with an average molecular weight of 400 to 5,000 [Special Publication No. 1919/1989], glycidyl esters and glycidyl ether addition compounds of polyamines [
Japanese Patent Publication No. 51-22416], diazabisiloalkenes and their salts [No. 54-26926], spiroacetal diamines [Japanese Patent Publication No. 55-16188], active hydrogen polyamine and alkylene oxide addition compounds [Japanese Patent Publication No. 53 -23724], ionizing radiation-curable desensitizing monomers and oligomers.

As the coloring agent, for example, electron-donating coloring agents well known in the technical field of pressure-sensitive copying paper can be used, and specific examples thereof include the following.

3.3-bis(p-dimethylaminophenyl)6-dimethylaminophthalide, 3-(p-dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)
Phthalide, 3,3-bis(I,2-dimethylindol-3-yl)-5dimethylaminophthalide, 3,3-bis(9ethylcarbazol-3-yl)-6-dimethylaminophthalide Triallylmethane dyes such as 4.4
'-bis-dimethylaminobenzhydrylbenzyl ether, N-halophenyl-leucoolamine, N-2,
Diphenylmethane dyes such as 4,5-trichlorophenylleucoolamine, thiazine dyes such as benzoylleucomethylene blue and p-niolohenzoylleucomethylene blue, 3-methyl-spiro-dinaphthopyran, 3
Spiro dyes such as phenyl-spiro-dinaphthopyran, 3-probilous biro-dihenzopyran, rhodamine-
Lactam dyes such as B-anilinolactam, rhodamine (0-chloroanilino)lactam, rhodamine (0-chloroanilino)lactam, 3-dimethylamino-7-methylfluorane, 3, diethylamino-6-methyl-7
-Chlorofluorane, 3-(N-ethyl-p-)luidino)-7-methylfluorane, 3-diethylamino-7
-N-methylaminofluorane, 3-diethylamino-
7-Sibenzylamiofluoran, 3-(N-ethyl-
p-Toluidino)-6-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-phenylaminofluorane, 3-(N-cyclohexyl-N
-methylamino) 6-methyl-7-phenylaminofluorane, 3-piperidino-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-xylidinofluorane, and other fluoran dyes.

As the color developer, for example, an electron-accepting color developer well known in the technical field of pressure-sensitive copying paper can be used, and specific examples thereof include the following.

Acid clay, activated clay, acpargite, zeolite,
Clays such as hentonite, phenolic resins, polyvalent metal salts of various aromatic carboxylic acids described in Japanese Patent Publication No. 51-25174, 2,2'-bisphenolsulfone compounds described in Japanese Patent Publication No. 54-106313 Organic color developers such as zinc salts, etc.

Color former-containing microcapsules are usually prepared by encapsulating a solution of a color former dissolved in oil. Examples of the oil include the following substances.

Aromatic carbonization of vegetable oils such as cottonseed oil, mineral oils such as kerosene, paraffin, naphthenic oil, and chlorinated paraffin, alkylated biphenyls, alkylated terphenyls, alkylated naphthalenes, diarylethanes, triarylmethanes, diphenylalkanes, etc. Hydrogens, dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate,
Esters such as dioctyl phthalate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, dioctyl adipate, etc.

As the encapsulation method, the conventionally known coacervation method, interfacial polymerization method, 1n-situ polymerization method, etc. are appropriately selected and used, but it is preferable to use synthetic resin as the wall material, and among them, melamine, The use of formaldehyde resin capsules is particularly preferred because the resulting pressure-sensitive copying sheet has excellent performance. Note that these microcapsules may contain auxiliary agents such as antioxidants and ultraviolet absorbers, if necessary.

The microcapsules prepared by the above method are usually aqueous dispersions, but they can be used as they are or after a concentration process such as filtration, through air drying, surface drying, fluidized drying, flash drying, spray drying, vacuum drying, and freezing. Most of the dispersion medium is removed by drying, infrared drying, high frequency drying, ultrasonic drying, finely pulverized drying, etc. to obtain powder capsules.

When the desensitizing component is a liquid, the capsule ink composition used in the present invention can be prepared by directly dispersing the powder capsules in the desensitizing component; however, usually non-aqueous ink compositions are used. It is prepared by adding desensitizing ingredients and powder capsules to the vehicle.

Various materials such as a resin, a white pigment, a capsule protective material, a photopolymerization initiator, a wax, a dryer, a thickener, a gelling agent, a surfactant, etc. can be added to this capsule ink composition as necessary. can.

Examples of non-aqueous ink media include benzene, toluene, xylene, cyclohexane, hexane, ligroin,
Methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monobutyl ether, diethylene glycol monobutyl acetate, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, n-hexanol, Volatile solvents such as cyclohexanol and 2-ethylhexyl alcohol; styrene, methyl methacrylate, butyl methacrylate, polyethylene glycol acrylate, propylene glycol dimethacrylate, pentaerythritol acrylate, trimethylolpropane diacrylate, pentaerythritol tetraacrylate, hexanediol acrylate, 1 .Ionizing radiation-curable compounds such as 2-butanediol acrylate, a reaction product of epoxy resin and acrylic acid, a reaction product of methacrylic acid, pentaerythritol and acrylic acid, a reaction product of maleic acid, diethylene glycol and acrylic acid; vegetable oil ( Drying oils such as linseed oil and sunflower oil, semi-drying oils such as soybean oil, dehydrated castor oil, polymerized oils, maleated oils, vinylated oils, urethanized oils), mineral oils (machine oil, spindle oil), etc. waxes such as carnauba wax, montan wax, paraffin wax, and microcrystalline wax;

Examples of the resin include rosin, trimerized rosin, polymerized rosin, (meth)acrylic ester, polyvinyl acetate, vinyl chloride/vinyl acetate copolymer, ethylene/maleic anhydride copolymer, styrene/maleic anhydride copolymer. Coalescence, methyl vinyl ether/maleic anhydride copolymer, isobutylene/maleic anhydride copolymer, modified polyvinyl alcohol, polyvinyl butyral, ethyl cellulose, nitrocellulose, hydroxypropyl cellulose, cellulose acetate propionate, cellulose acetate butylene Examples include rate.

Examples of white pigments include zinc oxide, titanium oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate,
Examples include clays such as magnesium silicate, calcium silicate, calcium sulfate, calcium phosphate, colloidal silica, zeolite, bentonite, kaolin, and calcined kaolin, and organic pigments such as melamine resin particles, urea resin particles, and polystyrene resin particles.

Capsule ink compositions typically contain 5 parts by weight of capsules per 100 parts by weight of the mixture of non-aqueous ink medium and desensitizing component.
~120 parts by weight, preferably about 10 to 70 parts by weight, but the proportion of the desensitizing component to 100 parts by weight of microcapsules is 10 to 500 parts by weight, preferably 30 to 3 parts by weight.
It is desirable to adjust the amount to about 0.00 parts by weight.

The capsule ink composition thus prepared is partially printed on the developer layer of the developer sheet by a printing method such as letterpress printing, offset printing, or flexographic printing. The amount of ink to be printed is adjusted as appropriate depending on the type of ink prepared, but is generally 0.3 to 10 g/r+? The amount is preferably adjusted within a range of about 1 to 5 g/m.

By the way, the color developer coating liquid for forming the color developer sheet is
In general, after pulverizing the color developer using a ball mill, attritor, sand mill, etc. as necessary, the above-mentioned white pigment, binder, and optionally a dispersant, colored dye, optical brightener, and ultraviolet absorber are added. It is usually prepared as an aqueous coating liquid by adding various auxiliary agents such as antioxidants, antifoaming agents, etc.

As the binder, a water-soluble binder or a Latinx binder is used, and examples of the water-soluble binder include proteins such as gelatin, albumin, and casein; cereal starch, pregelatinized starch, oxidized starch, etherified starch, Starches such as esterified starch: celluloses such as carboxymethyl cellulose and hydroxyethyl cellulose; water-soluble natural polymer compounds such as agar, sodium alginate, sucrose such as gum arabic, polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, and polyacrylamide , a sodium salt of a vinyl acetate/maleic anhydride copolymer, a maleic acid copolymer salt such as an ammonium salt of a styrene/maleic anhydride copolymer, and water-soluble synthetic polymer compounds. Examples of latex binders include styrene/phtadiene copolymer latex, acrylonitrile/phtadiene copolymer latex, acrylic ester latex, vinyl acetate latex, methyl methacrylate/butadiene copolymer latex, and carboxy-modified latexes thereof. (For example, acrylic acid modified) latex and the like.

The developer coating solution thus prepared is coated on paper, synthetic paper, etc. using a coating device such as an air knife coater, roll coater, blade coater, size press coater, curtain coater, bill blade coater, or short dwell coater.
It is coated on a suitable support such as a film.

The coating amount of the color developer coating liquid is adjusted as appropriate depending on the type of coating liquid prepared, etc., but is generally adjusted in the range of about 2 to 15 g/%, preferably about 3 to 7 g/m. .

The pressure-sensitive copying sheet of the present invention is not limited to the above-mentioned combinations, but can be made by, for example, replacing the electron-donating color former with the electron-accepting color developer, or by combining a ligand compound and a metal salt. It can also be applied to chelate coloring agents.

"Examples" Examples will be given below to further clarify the effects of the present invention, but the present invention is not limited to these Examples. Parts and % in the examples indicate parts by weight and % by weight, respectively, unless otherwise specified.

Example [Preparation of capsule ink] 8 parts of crystal violet lactone and 100 parts of alkyldiphenylethane (trade name: Hysol 5AS-29)
6, Nippon Petrochemical Co., Ltd.) was heated and dissolved to obtain internal phase oil.

Ethylene/maleic anhydride copolymer (product name: EMA-
2 to 200 parts of a 3.0% aqueous solution of
After the internal phase oil was emulsified in a solution whose pH was adjusted to 6.0 by adding 0% aqueous sodium hydroxide solution, the system was heated 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 dropped into the emulsion, stirred, heated to 80°C, kept at that temperature for 1 hour, lowered the pH to 3.5 with 0.2N hydrochloric acid, and kept for another 3 hours. After that, let it cool down to an average particle size of 3.6.
A microcapsule dispersion was obtained.

Next, 100 parts of powder capsules obtained by filtering and drying this dispersion were dispersed in 300 parts of ethanol, and ethyl cellulose (trade name: N4, manufactured by Vercules) was added to this.
30 parts and 100 parts of a desensitizer (trade name: KS-1530, manufactured by Sanyo Chemical Co., Ltd.) were added to obtain a capsule ink composition.

[Creation of color developer sheet]

65 parts of light calcium carbonate, 20 parts of zinc oxide, 3.5-
Mixture of zinc di(α-methylhensyl)salicylate and α-methylstyrene/styrene copolymer (melt ratio 80
/20) Add 20 parts (solid content) of carboxy-modified styrene-butadiene copolymer Latinx to the pulverized liquid obtained by grinding 15 parts of polyvinyl alcohol aqueous solution (solid content) and 300 parts of water in a ball mill for 24 hours. The developer coating solution prepared by
A color developer sheet was obtained by coating and drying with an air knife coater so that the color was 100%.

[Printing and evaluation]

A pressure-sensitive copying sheet of the present invention was obtained by flexographic printing the above capsule ink composition on a portion of the color developer layer of the color developer sheet so that the dry weight was 2.5 g/rrr.

When this pressure-sensitive copying sheet was folded as shown in the cross-sectional view of FIG. 1 and written with a writing instrument, a clear colored image was obtained on the developer layer facing the capsule ink printed area. However, no staining due to color development was observed in the capsule ink printed area.

Comparative Example A pressure-sensitive copying sheet was obtained in the same manner as in the example except that 100 parts of the desensitizer was not added when preparing the capsule ink composition.

Next, when this pressure-sensitive copying sheet was folded as shown in the cross-sectional view of FIG. 2 and written with a writing instrument, a clear colored image was obtained on the developer layer facing the capsule ink printed area. However, clear stains due to color development were also observed in the capsule ink printed areas.

"Effect" The pressure-sensitive copying sheet of the present invention has a color developer layer on the color developer layer of the color developer sheet.
It can be easily manufactured by only partially printing different types of capsule ink compositions, and the capsule ink printed area after recording does not generate unnecessary colored stains, and has excellent properties as a pressure-sensitive copying sheet.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the layer structure of a pressure-sensitive copying sheet of the present invention, and FIG. 2 is a cross-sectional view showing the structure of a conventional pressure-sensitive copying sheet. ■ = Writing instrument 2: Support 3: Color developer layer 4: Desensitizer-containing capsule ink layer 5: 4 Self-recorded image 6: Capsule ink layer

Claims (2)

[Claims] (1) Features: A capsule ink composition containing color former-containing microcapsules and a desensitizing component as basic components is partially printed on the developer layer of a color developer sheet having a color developer layer provided on a support. Pressure-sensitive copy sheet. (2) A pressure-sensitive copying sheet obtained by folding the sheet according to claim (1) so that the partially printed portion of the capsule ink composition and the color developer layer face each other.