JPH0298484A - Pressure sensitive recording sheet - Google Patents

Abstract

PURPOSE:To ensure excellent light resistance of a developed coloring matter and obtain a favorable blue developed hue by incorporating a metallic salt of a specified salicylic acid derivative as an electron-acceptive color developer, and incorporating a p-substd. aminophenylindolylazaphthalide derivative as an electron-donative dye. CONSTITUTION:A metallic salt of a salicylic acid derivative of formula I (wherein each of R1 and R2 is hydrogen or an alkyl, the total number of carbon atoms in R1 and R2 being 12 to 24) is incorporated as an electron-acceptive color developer, and a p-substd. aminophenylindolylazaphthalide derivative is incorporated as an electron-donative dye, in a pressure sensitive recording sheet for obtaining a developed color image through a reaction between a substantially colorless electron-donative dye and an electron-acceptive color developer. A developed coloring matter obtained through a reaction between a p- substd. aminophenylindolylazaphthalide derivative and a metallic salt of an ordinary well-known salicylic acid derivative has a cyan hue. On the other hand, the developed coloring matter obtained through a reaction between the p-substd. aminophenylindolylazaphthalide derivative and the metallic salt of the salicylic acid derivative of formula I has a blue hue, unexpectedly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a pressure-sensitive recording sheet.More specifically, it is an almost colorless electron-donating dye precursor (hereinafter referred to as a color former).
and an electron-accepting color developer (hereinafter referred to as color developer).

(Prior art) Conventionally, color formers and color developers, such as 11 FIJ, acid clay,
Pressure-sensitive recording materials that utilize color-forming reactions with clay materials such as activated clay, attapulgite, zeolite, bentonite, and kaolin, metal salts of aromatic carboxylic acids, and phenol formaldehyde resins are well known, and are disclosed, for example, in US Pat. ! Oj, No. 4/-70, same, 202. Guri No., Doko, RZO, Da7/No., J, J44R, J4A
No. 2, 7/, 2゜107, same, 730. HirojA
Issue, 2.73Q, Hiro! No. 7, 3.4! /r,λ! O
No., Tokukai Sho≠2-21,4t// No. Tokukai Sho jo-up
,o.

The battle is recorded in the RI issue, etc.

The properties that a pressure-sensitive recording sheet should have are: 1) high color developing ability and little decline in color developing ability over time;

2) The coloring body has excellent light resistance.

3) There is little yellowing of the developing surface when exposed to the source.

4) A desired coloring hue can be obtained.

etc. can be mentioned.

Among currently known color developers, metal salts of salicylic fermentation conductors exhibit the best performance. However, among the above-mentioned properties, the light resistance of the color former is still insufficient when exposed to sunlight for a long time.As a color former, p-
It has already been proposed to use 111m aminophenylindolyl asaphthalide derivatives (Tokukosho!/-/
6107, Tokuko Showa 11-312 Ko 3, Tokuko Showa sr--0
72t, special public Sho 6/-≠rzt, etc.).

But this p-1! The aminobutyl indolyl azaphthalide derivative has a drawback in that the hue becomes cyan when it reacts with a metal salt of a normal salicylic acid derivative, and the hue is not favorable for use as a recording sheet for blue coloring.

(Object of the Invention) An object of the present invention is to provide a pressure-sensitive recording sheet that has a color former that has excellent light resistance and that produces a good blue color hue.

(Structure of the Invention J The object of the present invention is to provide a pressure-sensitive recording sheet that obtains a colored image by a reaction between an almost colorless electron-donating dye and an electron-accepting color developer, in which the electron-accepting color developer contains - ['t'' indicated salicyl r
Contains a metal salt of an IR visiting conductor and serves as an electron-donating dye,
This was achieved by a pressure-sensitive recording sheet characterized in that it contains all p-@-converted aminophenylindolyl aza 7-thallide derivatives.

In the above formula (1), among the groups represented by R1 and R2, a hydrogen atom and a number of carbon atoms l
- Preferable alkyl group, especially carbon atom number ~/
A tertiary alkyl group for r is preferred.

Collective examples of groups represented by R1 and R2 include μ, hydrogen atom, methyl group, ethyl group, isopropyl group, t-butyl &, 1-octyl M, t-nonyl group, t-amyl group, t
-dodecyl group, cyclohexyl group, cyclohexylcyclohexyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group, octadecyl group, hexadecyl group, etc.

Examples of preferred metal salts of salicylic acid derivatives useful in the present invention are as follows: 3. ! -di-t-octylsalicylic acid, 3. j-di-t-nonylsalicylic acid, 3. ! -G-t
-dodecylsalicylic acid, 3-1-octyl-1-1-gtylsalicylic acid, 3-1-dodecyl-z-t-y-tylsalicylic acid,! -t-dodecylsalicylic acid,! Examples include zinc salts, nickel salts, aluminum salts, calcium salts, etc. -octadecylsalicylic acid, 3-methyl-1-1-octersalicylic acid 1j-cyclohexylcyclohexylsalicylic acid, and the like.

p-Itmaminophenyl indolyl azaphthalide! 8
It can be obtained by the reaction of the 4-isomer with commonly known metal salts of salicylic acid derivatives (zinc 3,!-bis(α-methylbenzyl)salicylate, zinc 3,5-di-t-butylsalicylate, etc.). The hue of the coloring material is cyan, whereas the coloring material obtained by the reaction of the p-substituted abanophenyl indolyl aza 7-thallide conductor with the gold pA salt of the salicylic acid derivative represented by the general formula (1). I never expected that the hue would turn blue.

In addition, the pressure-sensitive recording sheet according to the present invention further uses well-known materials other than the present invention, such as phenol spinners, metal salts of aromatic carboxylic acids, novolac resins, metal-treated novolac resins, and metal complexes. May be used.

Examples of these are Tokko Akihiro No. 0-2302, Tokko Akihiro No.
No. 117039, JP-A No. 7.2-144044113, JP-A-Sho μF-! /j10, JP-A-57-λtorr
No. 6, Tokukai Akira! No. r-47019, JP-A-Sho ty-iix
rt issue, JP-A-60-/777-5, JP-A-4/-9
It is described in No. 12try, etc.

Pigments useful in the present invention include zinc oxide, aluminum hydroxide, calcium carbonate, titanium oxide, magnesium carbonate, magnesium oxide, @telk barium, kaolin, activated clay, Merck, and the like.

Color developer and pigment include dispersant, water-soluble polymer, and other additives.
Together with the u agent, the dispersion is mechanically treated in an aqueous system using a ball mill, attritor, sand mill, etc. to obtain a dispersion. A part of the color developer can also be used as an emulsion in which the color developer is dissolved in an organic solvent and emulsified in water.

The dispersion or emulsion thus obtained is coated on a support with a binder applied to it.The final amount of developer coated on the support is 00197m-2,o9/m
2%, preferably from 0.297 m to 0.097 m2.

Examples of these binders include latexes such as styrene-butadiene copolymer latex, polyvinyl alcohol, maleic anhydride-styrene copolymer, starch, casein, gum arabic, gelatin, carboxymethyl cellulose, methyl cellulose, and other synthetic or Natural polymeric substances can be used.

The p-substituted aminophenylindolyl azaphthalide compound used as the color former of the present invention is preferably one represented by the following general formula.

In the above formula, one of X and Y represents -H, the other represents -CH=, and Z is a hydrogen atom, a halogen atom, Cl
-Cs alkyl group, C1-C12 alkoxy group, Cs
6 to C18 aryloxy group, or Hc7 to C13 aralkyloxy group, W represents a hydrogen atom or a halogen atom, R1 is a hydrogen atom or an unsubstituted or halogen atom having up to 11 carbon atoms, a hydroxyl group , represents an alkyl group or a C6 to C12 aryl group substituted with an ano group, or a lower alkoxy group, and a
2h hydrogen atom, cl-C8 alkyl group or C6-C
The 7-aryl group of I2, R3 and R4 are each independently a hydrogen atom or an alkyl group having up to 7.2 carbon atoms, unsubstituted or substituted with a halogen atom, a hydroxyl group, a 77 group, f, or a lower alkoxy group. Group, C5~
It represents a C7 7-chloroalkyl group, benzyl group, or phenyl group, and may further form a pyrrolidinyl group as -NR3R4.

Table 7 shows the preferred compounds as the p-substituted aminophenylindolyl aza 7-talide compound represented by the above formula.

In addition to i, p-a9 aminophenylindolyl aza 7-thalide derivatives, triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, indolylphthalide compounds, leuco auramine thread compounds, and rhodamine lactams are used as coloring agents. type compounds, triphenylmethane type compounds, triazene type compounds, spiropyran thread compounds, etc. may be used in combination.

The coloring agent used in the present invention is dissolved in a solvent, encapsulated, and applied to a support.

As a solvent, natural or synthetic oils can be used alone or in combination. Examples of solvents include cottonseed oil, kerosene, paraffin, t-phthenic oil, alkylated biphenyls, alkylated terphels, chlorinated nomurafins, alkylated phthalenes, diphenylalkanes, and the like.

As a method for manufacturing the color former-containing microcapsules, an interfacial polymerization method, an internal polymerization method, a phase separation method, an external polymerization method, a coacervation method, etc. are used.

In preparing a coating solution containing microcapsules containing a color former, a water-soluble binder or a latex binder is generally used. Further, a capsule protectant such as cellulose powder, starch particles, Merck, etc. is added to obtain a color former-containing microcapsule coating solution.

(Example of the invention) The present invention will be comprehensively explained below with reference to Examples.

Unexploded bA is not limited to the examples.

[Preparation of color former-containing microcapsule sheet] pH 4'
vc) 1M] partial sodium salt of polyvinylbenzenesulfonic acid (average molecular weight j00.000),
To 10 parts of the 4c aqueous solution, add the coloring agent t shown in Table 2, 09
The average particle size is obtained by emulsifying and dispersing color-forming oil-resistant oil dissolved in 100 parts of Shiitsubu A Pillnaphthalene. , jμ particle size was obtained. Separately, 1 part of melamine was added to 1 part of J7 fili% formaldehyde aqueous solution, 1 part of water, 30 parts of water, and stirred with heating, and after 30 minutes, a transparent mixed aqueous solution of melamine, formaldehyde, and melamine-formaldehyde initial condensate was obtained. The pH of this mixed aqueous solution was t,o to t,0. Hereinafter, this mixed aqueous solution of melamine, formaldehyde, and melamine-formaldehyde initial condensate will be referred to as an initial condensate solution. The initial condensate solution obtained by the above method was mixed with the above emulsified mixture, the pH was adjusted to 6.0 with 3.61ffi% hydrochloric acid solution while stirring, and the temperature was raised to 47'C for 360 minutes. Continued stirring. The capsule liquid was cooled to room temperature and diluted with 20 parts of sodium hydroxide to adjust the temperature to O.

To this capsule dispersion, 100 parts of a 10Nht% polyvinyl alcohol aqueous solution, 70 parts of carboquine-modified S [SR latex in solid content, 50 parts of starch particles, and 10 parts of calcium carbonate were added, and water was added to increase the solid content concentration to 20%. A microcapsule coating solution containing v4 stain coloring agent was prepared.

This coating solution was coated on j Og/m2 base paper using an air knife coater so that the solid content of 197 m2 was covered, and dried to obtain a color former-organized microcapsule sheet.

[Preparation of color developer sheet]

[Color developer sea]/J [Dispersion liquid preparation] 3,! -Zinc 1-octylsalicylate/! Part, calcium carbonate (Shiraishi Kogyo, Br1lliant-/j,
Average particle size O0jμ) 120 parts, activated clay 70 parts, zinc oxide 20s, sodium hexametaphosphate 1 part and water 200 parts
Dispersion liquid (A)'! 'Obtained.

[Adjustment of coating solution] Dispersion W (A) zoo part / 100 parts of 0% PVA-1/7 (manufactured by Kuraray) aqueous solution and 7 parts of carboxy-modified SBR latex (manufactured by Sumitomo Naugatac, S-307) (solid content ff57JDt) was adjusted to have a solid content concentration of 20% by adding water to obtain a coating liquid.

[Application of color developer sheet]

This coating liquid is 10! A developer sheet was obtained by coating a base paper of I/m 2 with an air knife coater so that a solid content of 1.097 m 2 was coated and drying.

[Color developer Zitco]

[Developer Sheet/J] In Preparation of Dispersion J, 3.5-
A developer sheet was obtained in the same manner as in Developer Sheet/J except that 75 parts of zinc di-t-dodecylsalicylate was used.

[Developer sheet 3J [Developer sheet/J [dispersion adjustment]]
3.5- parts instead of 75 parts of zinc t-octylsalicylate
10 parts of zinc di-t-octylsalicylate; and 3. A developer sheet was obtained in the same manner as in Developer Sheet I/J except that 5 parts of zinc j-bis(α-methylbenzyl)salicylate was used.

[Comparison developer sheet l]

[Developer sheet 1] [Dispersion liquid adjustment]
3. instead of 11 parts of zinc t-octylsalicylate. j-
A developer sheet was obtained in the same manner as [Developer Sheet 1] except that bis(α-methylbenzyl J zinc salicylate/! part) was used.

[Comparative color developer Zitco]

3° with [dispersion adjustment] of [color developer sheet/]! -Zinc t-octylsalicylate/! 3 instead of the department. j-
A developer sheet was obtained in the same manner as in Developer Sheet/J except that 75 parts of zinc di-t-butylsalicylate was used.

The comparative test method described below was conducted on each color former sheet and each color developer sheet obtained as described above.

(1) Hue test (λmax) Microcapsules l- of the color former-containing microcapsule sheet were stacked on the developer sheet, and a load pressure of iooKy7cm2 was applied. I applied it to develop the color. After leaving this in a dark place for λμ time, the fractional absorption distortion of the chromophore between wavelengths of 310 to 710 nm was measured, and the absorption maximum (λmax) and all (fresh r4 degrees DoJ) at the absorption maximum were measured.

(2) Color density test (1) Reflective vision of the color material after being left in the dark for 2 hours @ degree (V, D,)'2 densitometer (Macbeth RD j/≠ type) ).

(3) Light resistance test of coloring material After leaving it for 2 hours in a dark place obtained in (1), test the coloring material with a xenon phetometer (FAL-λ!AX-HC).
After irradiation for t hours using a mold (manufactured by Suga Test Instruments), the spectral absorption curve of the color former was measured, and the concentration DY at the absorption maximum was determined.
Measurements were taken. The spectral absorption curve was measured using a "Hitachi Color Analyzer Model 307" (Newly manufactured by Hitachi Seisakusho). Further, a value indicating light resistance (original resistance value) was calculated using the following formula.

The larger the original bone resorption value after xenon 7 edometer irradiation, the better the light resistance of the coloring agent.

The results obtained are shown in Table 2.

(Effect of the invention J As is clear from the results in Table 2, when the color former sheet and color developer sheet according to the example of the present invention are used, the light resistance of the color former is excellent and good compared to the comparative example. It can be seen that it exhibits a blue color.

Claims (1)

[Scope of Claims] In a pressure-sensitive recording sheet that obtains a colored image by a reaction between a nearly colorless electron-donating dye and an electron-accepting color developer, the electron-accepting color developer is represented by the general formula [I]. Contains a metal salt of a salicylic acid derivative, and p-
A pressure-sensitive recording sheet comprising a substituted aminophenylindolyl azaphthalide derivative. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the above formula, R_1 and R_2 represent hydrogen atoms or alkyl groups, and the total number of carbon atoms of R_1 and R_2 is 12 to 24.
It is. )