JPS61139481A - Recording sheet - Google Patents

Abstract

PURPOSE:To improve the light resistance of micro capsule layer by including a tetrahydroquinoline derivative of specific general formula in a micro capsule containing nearly colorless electron donative dye. CONSTITUTION:A tetrahydroquinoline derivative of the formula I(where R1 is H, a 1-8C alkoxy, a 6-18C aryloxy, or a 7-18C aralkyloxy group, R2 is a 1-15C alkyl, a 6-18C aryl, or a 7-18C aralkyl group, and R3 is H or methyl group) is contained in a micro capsule containing a nearly colorless electron donative dye to form a recording sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a recording sheet, and more particularly to a recording sheet that utilizes a color-forming reaction between a nearly colorless electron-donating dye and an electron-accepting compound.

(Prior art) Conventionally, color-forming reactions have been utilized between a nearly colorless electron-donating dye (hereinafter referred to as a color former) and an electron-accepting compound (hereinafter referred to as a color developer) that develops a color when it comes into contact with this color former. The deployment sheet is well known. For example, pressure-sensitive copy paper,
Thermal recording paper, electrically conductive recording paper, etc., U.S. patent, 7/
2,107 No. 1, Ko, 7JO, ≠! No., λ, 730,
4AJ7, 3, air, xzo, j, 4C12,
No. 127, 3, tri, rai No., J, 993, 131
No., J, Riyt, tri No., J, 5F24, 4ca
It is explained in detail in No. R, No. R, No. 00, No. Ory, etc.

The forms of these recording sheets include paper sheets in which a color forming agent is dissolved in a suitable solvent and a layer of microcapsules containing oil droplets is coated on a support, and a developer sheet containing a color developing agent. A combination of a bottom paper with a colorant layer coated on another support, and in some cases a middle paper with a microcapsule layer coated on one side of the support and a color developer layer on the other side. , or one in which the capsule and the color developer are contained on the same side of the support, or one in which the capsule or the color developer is contained in the support and the other is coated. .

However, these recording sheets have the following practically serious drawbacks.

(11.The light resistance of the microcapsule layer containing the color former is not sufficient. 1.The color development property of the microcapsule layer decreases when the microcapsule layer is irradiated with light.

(2) The light resistance of the coloring material is insufficient. ...The density of the coloring body decreases when the coloring body is irradiated with light.

Regarding improvement of light resistance of coloring material of pressure-sensitive recording sheet, /, 2-
dihydroquinoline, co, λl”)'limethyl-/, 2-
dihydroquinoline, /2. ! .

Attempts have been made to use hydrogen quinoline derivatives such as μm-tetrahydroquinoline, O-methyl-/, and λ-dihydroquinoline.

However, even when these compounds were used, the effect of improving the light resistance of the color former was insufficient. Furthermore, these compounds have little effect on improving the light resistance of the microcapsule layer.

(Object of the Invention) An object of the present invention is to provide a recording sheet in which the light resistance of a microcapsule layer containing a color former and the light resistance of a color former are significantly improved.

(Structure of the Invention) The object of the present invention is achieved by a recording sheet characterized by containing a tetrahydroquinoline derivative represented by the following formula -ff in microcapsules containing an almost colorless electron-donating dye. Ta.

(In the formula, R1 is a hydrogen atom, an alkoxy group having a carbon atom number/~t, an aryloxy group having a carbon atom number of 6 to If, or an aralkyloxy group having a carbon atom number of 7 to ir, R2 is a carbon atom number/, /J alkyl group, carbon atom number 6 - /I aryl group, carbon atom number 7 - /r aralkyl group, R3 represents a hydrogen atom or a methyl group) The above general formula [I]K, R1 is preferably a hydrogen atom, a methoxy group, an ethoxy group, or a benzyloxy group, and R2 is preferably an alkyl group having a carbon atom number of λ to t, an aryl group, or a benzyl group. Specific examples of these compounds include (1) -ethoxy-7-ethyl-co, co, μ-trimethyl-i, 2,3. a-tetrahydroquinoline (11) O-ethoxy-l-ethyl-1,2,J,
Hiro-tetrahydroquinoline 4if) A-ethoxy-7-octyl, 2. Pichitrimethyl/, 2. J, μm Tetrahydroquinoline GV) 4-ethoxy-/-7x = 2, 2, 4
C-trimethyl-/, 2. ! , 4 to 1 tetrahydroquinoline M to -ditoxy-7-phenyl-7, co, 3゜μm tetrahydroquinoline (vD & -ditoxy-7-xylyluco, co, IA-
trimethyl-/, J, J, μm tetrahydroquinoline 4/i) 4-nitoxy-/-(p-chlorophenyl)-1,! , gootrimethyl-/, 2. J.

μm Tetrahydroquinoline (viii) 4-xt*t-hensil-x,
J, a-trimethyl-/, 2. J, IA-tetrahydroquinoline (ix)7--x-t-? sea / -7x2/l/
-2, λ, 4cm trimethyl/, 2. J, It-tetrahydroquinoline (X) A-me, ) xy-/-7xnyl-2,2
, IA-trimethyl-7, co, J, 4A-tetrahydroquinoline (xi) O-methoxy-7-ethyl-/, 2. ! , 4A
-Tetrahydroquinoline (Xii) A-methoxy-l-benzyl-2,! ,
4A-trimethyl-i,-2,3,a-tetrahydroquinoline CMiD J-benzyloxy-7-ethyl-7,2゜3,l-tetrahydroquinoline (XM) 4-benzyloxy-7-7enyl λ, co .

≠-trimethyl-/, 2. J, 4A-tetrahydroquinoline (XV) 4-7 dinoxyl-octylco+ 21
"-trimethyl-/, 2.J, <4-tetrahydroquinoline (XVD/phenyl 2, -2, 1L-) 1
7 Mefk-/.

2.31μm Tetratetrahydroquinoline derivative-phenyl-1,2,J,g-tetrahydroquinoline C%/liD/-benzyluco,u,lA-trimethyl-7゜2,! , 4C-tetrahydroquinoline, and the like.

The preferred amount of the tetrahydroquinoline derivative used is based on the weight of the color former used, 7O-4COD, and more preferably 7O-4COD.
It weighs 200 yen.

The tetrahydroquinoline derivative can be added by dissolving it in a solution of a color former in an organic solvent, microcapsulating this solution, and coating it on a support.

The coloring agents used in the recording sheet of the present invention are not particularly limited, but specific compounds of these coloring agents include:
Examples include triarylmethane compounds, diphenylmethane compounds, xanthine compounds, thiazine compounds, spiro compounds, and mixtures thereof.

These coloring agents are dissolved in a solvent, encapsulated, and applied onto a support.

As a solvent, natural or synthetic oils can be used alone or in combination. Examples of solvents are cottonseed oil, kerosene, /4?
Examples include fins, naphthenic oils, alkylated biphenyls, alkylated terphels, chlorinated paraffins, alkylated naphthalenes, 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.

A water-soluble binder, latex-based pine goo, is generally used to prepare a coating solution containing icrocapsules containing a coloring agent. Further, a capsule protectant such as cellulose powder, starch particles, talc, etc. is added to obtain a color former-containing microcapsule coating solution.

Examples of color developers that react with the color forming agent used in the recording sheet of the present invention include acid clay, activated clay, attapulgite, zeolite, bentonite, clay materials such as kaolin, metal salts of aromatic carboxylic acids, and phenol resins. can be given.

These color developers are applied to a support such as paper along with a binder such as styrene-dutadiene latex.

The performance of the microcapsule sheet for pressure-sensitive recording of the present invention was tested using the following color developer sheet.

[Adjustment of color developer sheet]

70 parts of water, 2 parts of zinc oxide, it part of calcium carbonate and J
,! - Zinc α-methylbenzylsalicylate was added and mixed, and then dispersed for 1) 30 minutes using an attritor.
．． 5 parts and 72 parts of an aqueous solution of Owt SPY (degree of saponification to degree of polymerization of 2 to too much) were added and stirred uniformly to obtain a coating liquid. Apply this coating liquid to 101/m2o base paper K 4C
A developer sheet was obtained by coating and drying using an air knife coater capable of coating a solid content of f/m''O.

(Example of the invention) The present invention will be specifically explained below using Examples.

The present invention is not limited to the examples.
12E) Partial sodium salt of H'A-adjusted polyvinylbenzenesulfonic acid (average molecular weight zoo, ).

To 100 parts of a 4% aqueous solution of 00), the main part of crystal violet lactone and the part of the tetrahydroquinoline derivative shown in Table 1 were added to 1 part of /-phenyl-/-xylylethane.
By emulsifying and dispersing the coloring agent oil dissolved in 0.00 parts, the average particle size is
An O/W emulsion of jμ was obtained. Separately, 6 parts of melamine,
37 Add 1 part of thiformaldehyde aqueous solution and 13 parts of water to
After heating and stirring for 30 minutes, a transparent mixed aqueous solution of melamine, formaldehyde and melamine-formaldehyde initial condensate was obtained. This mixed aqueous solution was added to the above emulsion and mixed, and while stirring, a 20% acetic acid aqueous solution ff1K was added.
After adjusting the temperature to OK, the liquid temperature was raised to 6joC and maintained for 30 minutes to complete the encapsulation.

To this liquid were added 200 parts of a 2096 aqueous solution of etherified starch, 7 parts of starch particles (average particle diameter μOμ), and io parts of talc.

Then, water was added to adjust the solid content concentration to 20% to prepare a microcapsule liquid.

Dry this microcapsule liquid and weigh it! f/WL2 on a 4LO2/1rL2 base paper using an air knife coater and drying to obtain a microcapsule sheet.

Comparative Example 1 In place of the color former oil of Example, a color former oil was prepared by dissolving 100 parts of crystal violet lactone, λ, co, μ-trimethyl, μ parts of cordihydroquinoline, and 100 parts of phenyl-l-xylylethane. A comparative microcapsule sheet was obtained in the same manner as in the example except that .

Comparative Example 2 In place of the color former oil in Example, a color former oil prepared by dissolving μ parts of crystal violet lactone Hirobe, L, CO, J, 4A-tetrahydroquinoline in 100 parts of /-phenyl-7-xylylethane was used. A comparative microcapsule sheet was obtained in the same manner as in the example except for the above.

Comparative Example 3 In place of the color former oil in Example, 1 crystal violet lactone Hirobe was added to 10 l-phenyl-l-xylylethane.
A comparative microcapsule sheet was obtained in the same manner as in the example except that a color former oil dissolved in 0 parts was used.

Comparative test (υ Light resistance of microcapsule layer) After irradiating the microcapsule layer of the example and the comparative microcapsule sheet with a fluorescent light fading tester (33,0001 uX) for μ hours, it was placed on a developer sheet and 300 k
A load pressure of 2 g/an was applied to develop color. After being left in a dark place for a period of λ, the spectral absorption curve of the chromophore between wavelengths of 3ro to 7rOnm was measured, and the density at the absorption maximum was measured.

Separately, unirradiated Example and Comparative microcapsule sheets were stacked on a developer sheet, and a load pressure of j 00 kg/lx2 was applied to develop color. After leaving it for 21 A hours in a dark place, the spectral absorption curve of the chromophore between wavelengths 310 to 71 Onm was measured, and the concentration at the absorption maximum (Fresh concentration (Do
)) was measured.

The measurement of the spectral absorption curve was performed using Hitachi Color Analyzer JO7.
Table 1 shows the light resistance values obtained using the following formula.

A large light resistance value (tl) indicates that the microcapsule layer has excellent light resistance.

(Lightfastness of phantom color forming material Examples and comparative microcapsule sheets were layered on a developer sheet and a load of J 00 kg/Cm 2 was applied to develop color. After being left in a dark place for 2 hours, wavelength 310
The spectral absorption curve of the chromophore between 7rOnm and 7rOnm was measured, and the concentration at the absorption maximum (fresh concentration (Do)) was measured.

This color-forming material is
After irradiating with FAL-2jAX-) (C base) for μ hours, the spectral absorption curve of the chromophore was measured, and the concentration C at the absorption maximum was measured.
D) was measured.

The measurement of the spectral absorption curve was carried out using Hitachi Color Analyzer J07, and the original resistance value determined by the following formula is shown in Table 1.

Density (D) at absorption maximum after xenon fade meter irradiation The larger the light fastness value, the better the light fastness of the coloring material.

As shown in Table 1, it can be seen that the microcapsule sheet of the present invention is superior to the comparative microcapsule sheet in the light resistance of the microcapsule layer and the light resistance of the color former.

Claims (1)

[Scope of Claims] A recording sheet characterized by containing a tetrahydroquinoline derivative represented by the following general formula [I] in microcapsules containing an almost colorless electron-donating dye. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] (In the formula, R_1 is a hydrogen atom, an alkoxy group having 1 to 8 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, or 7 to 18 carbon atoms. (R_2 represents an alkyl group having 1 to 15 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms, and R_3 represents a hydrogen atom or a methyl group.)