JPS60107383A - Pressure-sensitive recording sheet - Google Patents

Abstract

PURPOSE:To provide a pressure-sensitive recording sheet excellent in the sunshine resistance by arranging 2,2,6,6-methylpiperazine derivative to be contained in a microcapsule containing virtually colorless electron donating dye or a developer containing an electron accepting compound. CONSTITUTION:In a pressure-sensitive recording sheet comprising a microcapsule layer containing a microcapsule obtained by dissolving a virtually colorless electron donating dye (e.g. triarylmethane based compound) into a solvent (e.g. cotton seed oil) and microcapsulizing oil drops and a developer layer containing an electron accepting compound (e.g. phenol resin), 2,2,6,6-tetramethylpiperazine derivative (e.g. a compound of the formula) is contained in the capsule preferably at the rate of 20-100wt% or in the developer layer at the rate of 5-50%.

Description

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

(Prior Art) A pressure-sensitive recording sheet is produced by dissolving a colorless electron-donating dye (hereinafter referred to as a coloring agent) in a suitable solvent.

A top paper coated with a microcapsule layer containing microcapsules containing the oil droplets on a support;
A base paper with a color developer layer containing an electron-accepting compound (hereinafter referred to as color developer) coated on another support, and in some cases, a microcapsule layer on one side of the support and a microcapsule layer on the other side. A combination of inner paper coated with a color developer layer, or a support containing the capsules and the developer on the same side, or a support containing either the capsules or the developer. There are some that contain one and coated with the other.

These pressure-sensitive recording papers are disclosed, for example, in US Pat.

TajO1lL71, same, 7JO,≠j7, same3,
≠/I, Kojθ, etc.

However, in these pressure-sensitive recordings, the sunlight resistance of the coloring material is still not sufficient, and there is a serious drawback in practical use.

Concerning improving the light resistance of coloring bodies in pressure-sensitive recording sheets.

The use of hydrogen quinoline derivatives in Tokuko Akihiro Tar 21 Core No. 21 is Tokuko Akihiro! 0-//λ reference discloses the use of aromatic aminos/derivatives.

However, even when these compounds were used, the effect of improving sunlight resistance was insufficient.

(Object of the Invention) An object of the present invention is to provide a pressure-sensitive recording sheet with significantly improved sunlight fastness.

(Structure of the Invention) The object of the present invention is to provide 2. This was achieved by a pressure-sensitive recording sheet characterized by containing a λ,6,6-titramethylpiperazine derivative.

λ according to the present invention, 2. Preferred specific examples of t,t-tetramethylbi-radizine derivatives include the compounds shown in Table 1.

When λ, λ, 6.6-titramethylpi is a radine derivative, the preferred amount used is t-200% by weight of the coloring agent used, more preferably 20 to 10% by weight.
Preferably, it is 0% by weight, and when it is contained in the developer layer, it is more preferably 3 to 100% by weight of the color developer used! ,! It is 0% by weight.

Examples of color developers used in the present invention include acid clay, activated clay, attapulgite, and zeolite.

Examples include clay materials such as bentonite, kaolin, metal salts of aromatic carboxylic acids, and phenolic resins.

The metal salt of aromatic carboxylic acid used as a color developer in the present invention is 1, for example, US Pat. No. 3,144! /≠No. 6, No. 32
132 Tar, special request! J-, J j /jr, etc.

The aromatic carboxylic acid in the above-mentioned metal salt of aromatic carboxylic acid is preferably one having a hydroxyl group in the ortho or ξ position with respect to the carboxy group, and among these, salicylic acid derivatives are preferable. Particularly preferred are those having a substituent such as an alkyl group, an aryl group, or an aralkyl group on at least one of the positions, and the total number of carbon atoms of the substituents is t or more.

Examples of particularly preferred aromatic carboxylic acids include:

3.! -di-t-butylsalicylic acid, 3.! -G1-
Amylsalicylic acid, 3.j-bis(α.α-dimethylbenzyl)salicylic acid, 3.j-bis(α-methylbenzyl)salicylic acid, 3-(α-methylbenzyl)-j-t
α・α-dimethylbenzyl) salicylic acid, 3・j-di-
t-Octylsalicylic acid, 3-cyclohexyl-3-(
Examples include α・α-dimethylbenzyl) salicylic acid.

Metals for forming metal salts with the aromatic carboxylic acids include magnesium, aluminum, calcium, scandium, titanium, vanadium, chromium, iron, cobalt, nickel, copper, and nitrous.

Examples include gallium, germanium, strontium, yttrium, zirconium, molybdenum, cadmium, indium, tin, antimony, barium, tungsten, lead, and bismuth. Among these metals, zinc, tin aluminum, etc. are particularly effective.

The most effective of these is zinc.

The phenolic resins used as the color developer in the present invention include those known as so-called novolac resins, such as phenylphenol resin, paratertiary butylphenol resin, octylphenol resin, and paranonylphenol resin. , parachlorophenol resin, paracumylphenol resin, etc. Preferred among these is noraphenylphenol resin. These color developers are applied to a support such as paper 1 together with a binder such as styrene butadiene latex.

The color former that reacts with the color developer used in the recording sheet of the present invention is not particularly limited, but specific examples of these color formers include triarylmethane compounds, diphenylmethane compounds, xanthine compounds, and thiazine. Examples thereof include compounds such as a type compound, a spiro type compound, or a mixture thereof.

These color formers are dissolved in a solvent and encapsulated, or dispersed in a binder solution 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, naphthenic oil, alkylated biphenyls, alkylated terfels, chlorinated paraffins, alkylated heptarenes, 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, talc, etc. is added to obtain a color former-containing microcapsule coating solution.

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

The invention is not limited to the examples.

Example 1 Partial sodium salt of polyvinylbenzenesulfonic acid adjusted to pn reference (average molecular weight zoo, ).

Emulsifying and dispersing a coloring agent oil dissolved in 100 parts of aqueous solution of 00), μ parts of crystal violet lactone, and 2 parts of compound (I) shown in Table 1, ioo parts of t-/-phenyl-l-xylylethane. The average particle size is d, jμ, O/
A W emulsion was obtained. Separately, 6 parts of melamine, 1 part of a 37% formaldehyde aqueous solution, and 3 parts of water were heated and stirred for 30 minutes to obtain a transparent mixed aqueous solution of melamine, formaldehyde, and melamine-formaldehyde initial condensate. This mixed aqueous solution was added to the above emulsion and mixed, and the pn was adjusted to 1.0% with a 20% acetic acid aqueous solution while stirring.
0, and the liquid temperature was raised to 44-'C and held for 30 minutes to complete encapsulation.

To this liquid were added 00 parts of a 20% aqueous solution of etherified starch, a care part of starch particles (average particle diameter tioμ), and 10 parts of talc.

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

The dry weight of this microcapsule liquid is jl/TrL2.
It was coated onto 4I011/m base paper using an air knife coater and dried to obtain a microcapsule sheet.

Example 2 In place of the coloring agent oil of Example 1, y μ part of crystal violet lactate and compound (II) shown in Table 7, J part = i
A microcapsule sheet was obtained in the same manner as in Example 1, except that a color former oil dissolved in ioo/phenyl-l-xylylethane was used.

[Microcapsule sheet for comparison]

In place of the color former oil in Example 1, crystal violet lactone was added to l-phenyl-l-xylylethane.
A comparative microcapsule sheet was obtained in the same manner as in Example 1, except that the color former oil dissolved in the oo part was used.

Example 3 2 parts of zinc oxide and lt part of calcium carbonate in 70 parts of water, 3.
1 part of zinc jt-di-α-methylbenzylsalicylate and part of compound (I) shown in Table 1 were added and mixed, and the carboxy-modified SDR latex was solidified into the solution that was dispersed for 30 minutes using an attritor. 2.5 parts and 10w1%P per minute
72 parts of VA (saponification degree tata% polymerization degree 1000) aqueous solution was added and stirred uniformly to obtain a coating liquid. This coating liquid! A color developer sheet was obtained by applying and drying the mixture to a base paper of 09/TrL2 using an air knife coater capable of applying a solid content of ≠g/rrL2.

Example 4 A color developer sheet was obtained in the same manner as in Example 3, except that 7 parts of compound +1[) shown in Table 1 was used instead of 7 parts of compound (I) in Example 3.

[Developer sheet for comparison]

A comparative color developer sheet was obtained in the same manner as in Example 3 except that 7 parts of Compound (I) was not used.

Comparative Test Examples 1 to 2 and comparative microcapsule sheets were stacked on Examples 3 to 4 and comparative color developer sheet 100 to 9
A load of 7 cm was applied to develop color.

After leaving it in the dark for 2 hours, the wavelength was 31rO~71on.
The spectral absorption curve of the color former between m was measured, and the concentration at the absorption maximum (fresh concentration fDol) was measured.

After irradiating this chromophore with sunlight for an hour, the spectral absorption curve of the chromophore was measured, and the concentration (D
) was measured.

The measurement of the spectral absorption curve was carried out using Hitachi Color Analyzer Model 307, and the light fastness values calculated using the following formula are shown in Table 2.

The larger the light resistance value, the better the sunlight resistance of the colored material.

As shown in Table 2, the sunlight resistance of the colored material developed with the microcapsule sheet of the example on the comparative color developer sheet is significantly improved compared to that of the colored material developed with the microcapsule sheet of the comparative example. I understand that.

Furthermore, it can be seen that the sunlight resistance of the colored material developed on the developer sheet of the example by overlapping the microcapsule sheet for comparison is significantly improved than that of the colored material developed on the developer sheet of the comparative example.

Patent applicant Fuji Photo Film Co., Ltd. Procedural amendment 1, case description Showa SR year patent application No.: l/jI/44
No. 2, Name of the invention Pressure-sensitive recording sheet 3, Relationship with the person making the amendment Patent applicant Location: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name (520) Fuji Photo Film Co., Ltd. Contact information 106
Fuji Photo Film Co., Ltd., Tokyo Head Office, 2-26-30 Nishi-Azabu, Minato-ku, Tokyo Not yet amended Subject of the amendment The following under-amendments have been made to the detailed description of the invention in column 5 of the description.

l) 1st page, row j (Compound ■) " ” and correct it.

Claims (1)

[Claims] 4. In a microcapsule containing a colorless electron-donating dye or in a color developer layer containing an electron-accepting compound. Pressure-sensitive recording sheet characterized by containing a j-tetramethylbiba-radizine derivative