JP3376848B2 - Thermal multiple copy sheet - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive multiplex copy sheet capable of simultaneously performing heat-sensitive recording on two or more sheets. The present invention relates to a thermosensitive recording medium having excellent dot reproducibility. 2. Description of the Related Art Thermosensitive recording in which a color image is obtained by making use of a color reaction between a colorless or light-colored leuco dye and a colorant and reacting both color-forming substances with heat energy from a thermal head. The body is well known. Such a thermosensitive recording medium is relatively inexpensive, and its recording equipment is compact and easy to maintain, so that it is used not only as a recording medium for facsimile machines and various computers but also in a wide range of fields. In particular, since this type of heat-sensitive recording sheet is used as a receipt, there is an increasing demand for several sheets of heat-sensitive recording once. As a means for printing on a plurality of sheets in a single thermal recording, it is conceivable to apply the thermal recording in a state in which a plurality of thermal recording sheets are superimposed. An easily legible recorded image cannot be formed on the thermosensitive recording layer that does not come into contact with the recording tool. In order to solve this problem, a heat-sensitive multiple copy sheet is provided on one surface of a base sheet with an electron-donating colorless or light-colored basic dye and an electron-accepting colorant which forms the basic dye by a thermal reaction. A heat-sensitive recording layer containing a color developer and a heat-fusible layer containing an electron-donating colorless or light-colored basic dye and a heat-fusible substance on the other surface of the base sheet; And a recording layer containing, on one surface of the base sheet, an electron-accepting color developer for coloring a basic dye in the heat-fusible layer of the first recording sheet. A heat-sensitive multiple copy sheet comprising a combination with a second recording sheet having
895, and Japanese Patent Application Laid-Open No. 57-96896. However, the problem that the recording sensitivity and dot reproducibility are lower as the number of sheets reaches the lower sheet of the multiple sheets has not been solved. [0005] The object of the present invention has been studied in view of such conventional drawbacks. The object of the present invention is to achieve particularly high recording sensitivity and excellent dot reproducibility. An object of the present invention is to provide a heat-sensitive multi-copy sheet. According to the present invention, there is provided a heat-sensitive multiplex copy sheet comprising a combination of a first recording sheet serving as an upper sheet and a second recording sheet serving as a lower sheet. In the recording layer 6 of the recording sheet 7, an oil absorption of 16
Using 0 to 260 ml / 100 g of silicon dioxide , and
Milk of salicylic acid derivative metal salt as a developer in recording layer 6
By using the product, particularly high recording sensitivity in multi several sheets sheet, as a result of the check that excellent dot reproducibility, and have completed the present invention. That is, referring to FIG. 1, according to the present invention, a colorless or light-colored basic dye having an electron donating property and an electron accepting property for forming the dye by a thermal reaction are provided on one surface of a substrate sheet 1. A heat-sensitive recording layer 2 containing a coloring agent, and a heat-fusible material containing a colorless or light-colored electron-donating basic dye and a heat-fusible substance on the other surface of the base sheet 1. A first recording sheet 4 having a layer 3 and an electron-accepting color developing color of the basic dye in the heat-fusible layer 3 of the first recording sheet 4 on one surface of the base sheet 5 And a second recording sheet 7 having a recording layer 6 containing an agent.
This is a thermosensitive multiple copy sheet using 100 g or more. DETAILED DESCRIPTION OF THE INVENTION In the heat-sensitive multiplex copying sheet of the present invention, paper, various nonwoven fabrics, plastic films, synthetic paper, metal foil, etc. are used as the base sheet 1 and base sheet 5.
Alternatively, a composite sheet or the like combining these is used. 70 ml of oil absorption as filler for the second recording sheet 7
/ 100 g or more, but with an oil absorption of 7
If less than 0 ml / 100 g, the first recording sheet 4 having the heat-fusible layer 3 containing an electron-donating colorless or light-colored basic dye and a heat-fusible substance, Can not be sufficiently absorbed, hindering the reaction between the colorless or light-colored basic dye and the electron-accepting color developer, resulting in low recording sensitivity and poor dot reproducibility. Examples of the electron-donating colorless or light-colored basic dyes used in the heat-sensitive recording layer 2 and the heat-fusible layer 3 include the following (1) to (5). (1) Triarylmethane compound 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3- (p-dimethylaminophenyl) -3-
(1,2-dimethylindole-isyl) phthalide,
3- (p-dimethylaminophenyl) -3- (2-phenylindol-3-yl) phthalide, 3,3-bis-
(2) diphenylmethane type (p-ethylcarbazol-3-yl) -3-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -5-dimethylaminophthalide, etc. Compound 4,4-bis-dimethylaminobenzhydrin benzyl ether, N-halophenylleuco auramine, N-
(3) xanthene compounds rhodamine B-anilinolactam, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-butylaminofuran Orane, 3-diethylamino-7- (2-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-
Dibutylamino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3-ethyl-tolylamino-6-methyl-7-anilinofluoran, 3-cyclohexyl- Methylamino-6-methyl-7-anilinofluoran, 3 diethylamino-6-chloro-7- (β-ethoxyethyl) aminofluoran, 3-diethylamino-6-chloro-7-
(Γ-chloropropyl) aminofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-
N-cyclohexyl-N-methylamino-6-methyl-
7-anilinofluoran, 3-diethylamino-7-phenylfluoran, 3- (N-isoamyl-N-ethylamino) -6-methyl-7-anilinofluoran and the like; (5) Spiropyran compounds 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, benzylspiro-dinaphthopyran, 3-methylnaphtho- (3-methoxy-benzo) ) -Spiropyran and the like. Further, a mixture of these is used, and is selectively used according to characteristics according to the use, and is selectively used according to characteristics according to the use. The electron-accepting color developer used for the heat-sensitive recording layer 2 includes 4,4 '-(1-methylpentylidene) bisphenol, N-stearyl-p-aminophenol, tetramethylbisphenol A, 4 '-(α-
Methylbenzylidene) bisphenol, 4,4 ′-(p
-Phenylenediisopropylidene) bisphenol,
4,4 ′-[1.3-phenylenebis (1-methylethylidene)] bisphenol, 4,4′-cyclohexylidenebisphenol, 2,2′-bis (4-hydroxy-3-isopropylphenyl) propane, α , Α′-bis (3-methyl-4-hydroxyphenyl) -m-diisopropylbenzene, n-butylbis (hydroxyphenyl) acetate, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3,3 5-triisopropylbenzene, 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol, stearyl gallate, 4-hydroxy-4′-iso Propoxydiphenyl sulfone, 2,
2-bis (4,4′-hydroxyphenyl) sulfone,
4,4-thiobis (6-t-butyl-m-cresol), 2,2-bis (3-allyl-4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxy-3) -Methylphenyl) sulfide, tetramethylbisphenol S, etc., and particularly, 4-hydroxy-4′-isopropoxydiphenylsulfone, and 2,2-bis (3-allyl-4)
-Hydroxyphenyl) sulfone is preferred. Examples of the heat-fusible substance used in the heat-fusible layer 3 include low-melting waxes such as carnauba wax, paraffin wax, and microcrystalline wax. Further, the recording layer 6 of the second recording sheet 7
Examples of the electron-accepting developer used for the developer include materials used for the developer and the pressure-sensitive copying sheet used in the heat-sensitive layer, such as acid clay, activated clay, attapulgite,
Clays such as zeolite and bentonite, phenolic resins, various polyvalent metal salts of aromatic carboxylic acids as described in JP-B-51-25174;
2,2 'as described in -106316
-Zinc salts of bisphenolsulfonic acid compounds, metal salts of salicylic acid derivatives, and mixtures thereof. Among them, emulsions of salicylic acid derivative metal salts have particularly high recording sensitivity and excellent dot reproducibility. The heat-sensitive recording layer 2 of the first recording sheet 4
It is formed as a coating layer of an electron-donating colorless or light-colored basic dye, an electron-accepting developer for developing the basic dye by a thermal reaction, and a water-soluble or water-dispersible binder. The heat-fusible layer 3 of the first recording sheet 4 is a coating layer of a heat-melted material containing a colorless or pale-color electron-donating basic dye and a heat-fusible substance. The ratio of the basic dye and the heat-fusible substance in the formed heat-fusible layer 3 is not particularly limited, but usually, the basic dye 3 is added to 100 parts by weight of the heat-fusible substance. About 40 parts by weight are used. In the heat-fusible layer 3, the heat-fusible substance acts as a binder for a basic dye and a sensitivity improver. Further, the recording layer 6 of the second recording sheet 7
Is formed as a coating layer of an electron-accepting developer for developing a basic dye and a water-soluble or water-dispersible binder in the heat-fusible layer 3 of the first recording sheet 4. Examples of the water-soluble or water-dispersible binder used for the heat-sensitive recording layer 2 of the first recording sheet 4 and the heat-sensitive recording layer 6 of the second recording sheet 7 include various starches and hydroxyethyl cellulose. , Methylcellulose, carboxymethylcellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, styrene-maleic anhydride copolymer, ethylene-maleic anhydride copolymer and other water-soluble binders, styrene-butadiene copolymer, Water-dispersible binders such as acrylonitrile-butadiene copolymer and acrylate-butadiene copolymer are exemplified. As the pigment of the recording layer 6 of the second recording sheet 7, an inorganic or organic pigment having an oil absorption of 70 ml / 100 g or more is used, and silicon dioxide is particularly preferable. The coating liquid for forming the heat-sensitive recording layer 2 of the first recording sheet 4 and the recording layer 6 of the second recording sheet 7 includes diatomaceous earth, clay, calcined clay, talc, kaolin, calcined Inorganic pigments such as kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, alumina, aluminum hydroxide, synthetic magnesium silicate, synthetic aluminum silicate, polystyrene, polymethacrylate, urea resin, urea-formalin resin And other organic pigments. The coating liquid for forming the heat-sensitive recording layer 2 of the first recording sheet 4 contains a high-grade calcium stearate or the like for the purpose of preventing head abrasion and sticking of the thermal recording device. Fatty acid metal salts, paraffin, paraffin oxide, polyethylene, polyethylene oxide, stearic acid amide, waxes such as caster wax and the like may be added. Further, as a sensitivity improver, metaterphenyl, parabenzylbisphenyl, hydroxynaphthoic acid ester, stearic acid amide, tribenzylamine, naphthalene derivative, dibenzyl terephthalate, dibenzyl oxalate, bis (paramethylbenzyl) oxalate, bis (oxalate) Various oxalates such as parachlorobenzyl) may be added. Further, various additives, for example, ultraviolet absorption, are contained in the coating liquid for forming the heat-sensitive recording layer 2 of the first recording sheet 4 and the heat-sensitive recording layer 6 of the second recording sheet 7. Agents, antioxidants, dispersants, fluorescent dyes and the like may be added. The heat-sensitive multiplex copy sheet of the present invention contains, on one surface of the base sheet 1, an electron-accepting color developer which causes a colorless or light-colored basic dye having an electron donating color to develop by a thermal reaction. A first sheet having a heat-sensitive recording layer and a heat-fusible layer containing, on the other side of the base sheet, a colorless or pale-color electron-donating basic dye and a heat-fusible substance; Recording sheet 4 and a recording layer containing, on one surface of a base sheet 5, an electron-accepting color developer for developing a basic dye in the heat-fusible layer 3 of the first recording sheet 4. 6 in combination with the second recording sheet 7. The heat-sensitive multiplex copy sheet of the present invention having the above-described structure includes a first recording sheet 4 and a second recording sheet 7.
In a state where the heat-fusible layer 3 and the heat-sensitive recording layer 6 are in contact with each other, and the heat-sensitive recording layer 2 of the first recording sheet 4 is overlapped.
When heat-sensitive recording is performed by a thermal head or the like, the heat-fusible layer 3 is thermally transferred to the heat-sensitive recording layer 6, and at the same time, the basic dye in the heat-fusible layer 3 and the developer in the recording layer 6 are removed. Due to the thermal reaction described above, recording on the heat-sensitive recording layer 6 is performed, and thermal recording can be simultaneously performed on the first recording sheet 4 and the second recording sheet 7. Using the heat-sensitive multiple copy sheet of the present invention,
To obtain more than one copy, for example, in the case of three copies, FIG.
As shown in FIG. 3, a heat-sensitive recording layer 9 containing an electron-accepting color developer on one surface of a base sheet 8 is provided between a first recording sheet 4 and a second recording sheet 7. And a heat-fusible layer 10 containing a colorless or pale-color electron-donating basic dye and a heat-fusible substance on the other surface of the base sheet 8.
May be interposed. The heat-sensitive multiplex copy sheet of the present invention used as described above can be used as the second recording sheet 7 by using a filler having an oil absorption of 70 ml / 100 g or more. Has high recording sensitivity,
A heat-sensitive multiplex copy sheet having excellent dot reproducibility can be obtained. EXAMPLES The specific structure of the heat-sensitive multiplex copy sheet of the present invention will be described below based on examples. <Example 1> (1) Formation of base sheet 5 50 parts by weight of LBKP having a CSF freeness of 300 ml and CSF
A sedimentable calcium carbonate (Phirako Shiraishi Kogyo Co., Ltd.) is contained in a pulp slurry composed of 50 parts by weight of NBKP having a freeness of 300 ml.
C) 40 parts by weight, cationized starch (manufactured by Nisseki Chemical Co., Ltd.) 3
0.3 parts by weight of anionic polyacrylamide (Polystron 117 manufactured by Arakawa Chemical Co., Ltd.) and 0.5 part by weight of a sizing agent for neutrality (Hercon W, manufactured by Dick Hercules Co., Ltd.) were added. Paper, and lightly calendered to a thickness of 33 μm and a surface smoothness of 60
A paper having 0 seconds, a size degree of 10 seconds and a filler content of 28% was obtained. (2) Preparation of coating liquid for forming heat-sensitive recording layer 2 of first recording sheet 4 Preparation of solution A: 3-dibutylamino-6-methyl-7-anilinofluoran (basic dye) ··· 10 parts by weight 20% by weight polyvinyl alcohol (Kuraray: Kuraray Poval 105) ··· 10 parts by weight Water ························································································· The mixture was pulverized to prepare a liquid A. Solution B: 4-hydroxy-4′-isopropoxydiphenyl sulfone: 10 parts by weight 20% by weight polyvinyl alcohol (Kuraray: Kuraray Poval 105): 10 parts by weight Water: 20 parts by weight The composition having the above composition was pulverized with a sand mill until the average particle diameter became 1.5 μm, to prepare a liquid B. Liquid C preparation: metaterphenyl (sensitizer): 10 parts by weight 20% by weight polyvinyl alcohol (Kuraray: Kuraray Poval 105): 10 parts by weight Water: composition of 20 parts by weight or more Was pulverized with a sand mill until the average particle diameter became 1.0 μm to prepare a liquid C. Subsequently, 40 parts by weight of the liquid A, 80 parts by weight of the liquid B, 40 parts by weight of the liquid C, and amorphous silica (manufactured by Mizusawa Chemical: P
-527) 15 parts by weight, 20 parts by weight polyvinyl alcohol (Kuraray: Kuraray Poval 105) 5 parts by weight, water 3
0 parts by weight were mixed and stirred to obtain a coating solution for forming the heat-sensitive recording layer 2. (3) Forming the Thermosensitive Recording Layer 2 On one surface of the base sheet 1 (glassine paper having a basis weight of 30 g / m ² ), 4.0 g (dry) of the coating liquid obtained in the item (2) was applied. /
After coating at a rate of m ² , the coated surface was subjected to a calender treatment to form a heat-sensitive recording layer 2. (4) Formation of the heat-fusible layer 3 10 g of 3-piperidino-6-methyl-7-anilinofluoran (basic dye), 30 g of carbana wax (heat-fusible substance), and stearic acid 15 g of amide from 120 to
After melting at 130 ° C., the melt was applied to the other surface of the base sheet 1 at 70 to 80 ° C. at a rate of 3.0 g (dry) / m 2.
The first recording sheet 4 was obtained by coating at a ratio of ² to form the heat-fusible layer 3. (5) Preparation of Coating Liquid for Forming Thermal Recording Layer 6 of Second Recording Sheet 7 Amorphous silicon dioxide 65 having an oil absorption of 160 ml / 100 g
Parts by weight, zinc oxide 20 parts by weight, mixed melt of zinc 3,5-di (α-methylbenzyl) salicylate and α-methylstyrene-styrene copolymer (mixed melt weight ratio = 80/20) 1
A dispersion obtained by grinding 5 parts by weight, 5 parts by weight of an aqueous polyvinyl alcohol solution (solid content) and 300 parts by weight of water with a ball mill for 24 hours is mixed with 20 parts by weight of a carboxy-modified styrene / butadiene copolymer latex (solid content). And add
A coating liquid for forming the heat-sensitive recording layer 6 was prepared. (6) Coating for forming the heat-sensitive recording layer 6 obtained in the above item (5) on one surface of the base sheet 5 of the item (1) where the second recording sheet 7 is formed. The working liquid was applied by an air knife coater at a rate of 5 g (dry) / m 2 to form a heat-sensitive recording layer 6, thereby forming a second recording sheet 7. Example 2 In the formation of a recording sheet 7, amorphous silicon dioxide 6 having an oil absorption of 160 ml / 100 g was used.
A thermosensitive recording medium manufactured in the same manner as in Example 1 except that amorphous silicon dioxide having an oil absorption of 260 ml / 100 g was used instead of 5 parts by weight is referred to as Example 2. <Reference Comparative Example 1> In forming the recording sheet 7, the oil absorption amount was 160 ml / 10.
Reference Comparative Example 1 is a thermosensitive recording medium produced in the same manner as in Example 1, except that 65 g of calcined kaolin having an oil absorption of 90 ml / 100 g was used instead of 65 g of amorphous silicon dioxide of 0 g. . <Reference Comparative Example 2> In forming the recording sheet 7, the oil absorption amount was 160 ml / 10.
Thermal recording produced in the same manner as in Example 1, except that 65 g of calcined kaolin (trade name: Alphatex) having an oil absorption of 79 ml / 100 g was used instead of 65 g of amorphous silicon dioxide of 0 g. Reference Example 2
And Comparative Example 1 In forming the recording sheet 7, amorphous silicon dioxide 6 having an oil absorption of 160 ml / 100 g was used.
Except for using 65 parts by weight of light calcium carbonate having an oil absorption of 57 ml / 100 g instead of 5 parts by weight,
A thermosensitive recording medium manufactured in the same manner as in Example 1 is referred to as Comparative Example 1. Comparative Example 2 In forming the recording sheet 7, amorphous silicon dioxide 6 having an oil absorption of 160 ml / 100 g was used.
Except for using 65 parts by weight of heavy calcium carbonate having an oil absorption of 37 ml / 100 g instead of 5 parts by weight,
A thermosensitive recording medium manufactured in the same manner as in Example 1 is referred to as Comparative Example 2. Comparative Example 3 In forming the recording sheet 7, the oil absorption was 160 ml / 10.
A heat-sensitive recording material manufactured in the same manner as in Example 1 except that 65 g of aluminum hydroxide having an oil absorption of 43 ml / 100 g was used instead of 65 g of amorphous silicon dioxide of 0 g was compared with Comparative Example 3 I do. As described above, in the first embodiment,
2. Evaluation results of dot reproducibility of the second recording sheet 7 of Reference Comparative Examples 1 and 2 and Comparative Examples 1, 2, and 3 and a heat-sensitive evaluation machine (trade name: TH-PMD, manufactured by Okura Electric Co., Ltd.) Each thermosensitive recording medium was colored at an applied energy of 0.45 mJ / dot, and the color density of the obtained recorded image was measured using a Macbeth densitometer [RD
-914 type, manufactured by Macbeth Co., Ltd.] in the visual mode, and the results are shown in Table 1. [Table 1] As is clear from the examples, by using a filler having an oil absorption of 100 ml / 100 g or more as the filler of the second recording sheet 7, the recording sensitivity is particularly high in the multiple sheets, and the dot is improved. An article with excellent reproducibility was obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view showing an example of a use state of a heat-sensitive multiplex copying sheet of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of a use state of the thermal multiplex copying sheet of the present invention. DESCRIPTION OF SYMBOLS 1: Base sheet of first recording sheet 2: Thermal recording layer of first recording sheet 3: Heat-fusible layer of first recording sheet 4: First recording sheet Sheet 5: Base sheet of second recording sheet 6: Thermal recording layer of second recording sheet 7: Second recording sheet 8: Base sheet of third recording sheet 9: Third Heat-sensitive recording layer 10 of recording sheet: Heat-fusible layer 11 of third recording sheet: Third recording sheet

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-6-1064 (JP, A) JP-A-7-164758 (JP, A) JP-A-7-329423 (JP, A) JP-A-6-64 72026 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/28-5/34

Claims (1)

(57) Claims 1. An electron-donating colorless or light-colored basic dye and an electron-accepting color developing the dye by a thermal reaction on one surface of the base sheet 1. Heat-sensitive recording layer 2 containing a colorant or a light-colored basic dye having an electron donating property and a heat-fusible substance on the other surface of the base sheet 1. A first recording sheet 4 having 3;
Second recording having a recording layer 6 containing an electron-accepting color developer for coloring a basic dye in the heat-fusible layer 3 of the first recording sheet 4 on one surface of the base sheet 5 Thermal multiplex copy sheet consisting of a combination with the sheet 7
Te, oil absorption as a filler in the recording layer 6 of the second recording sheet 7 with a silicon dioxide 160~260ml / 100g, and the color developer is a salicylic acid derivative metal salt in the recording layer 6
Sensitive multiple copy sheet, characterized in the emulsion der Rukoto.