JPS58148789A - Pressure-sensitive duplicate paper - Google Patents

Abstract

PURPOSE:To improve the concentration and light fastness of color by using a lactone colorant and a methine colorant as pressure-sensitive colorants and adding a 2,6-di-substituted phenol derivative to a developer agent in a pressure- sensitive duplicate paper using a clay mineral-based developer. CONSTITUTION:A lactone colorant of phthalide or fluoran series and a methine colorant of the formulaI(where X is a substituted or nonsubstituted phenyl, naphthyl, indolyl or beta-styryl, R1-R6 are each amino, alkyl, alkoxy or halogen atom, and R7 and R8 are each H, a halogen atom or a lower alkoxy) are mixed, as needed, with an alkanolamine, a sequestering agent, etc., and micro-capsulated to form a color micro capsule layer. On the other hand, 1-50pts.wt. a 2,6- di-substituted phenol derivative on the basis of 100pts.wt. developer is added to the layer containing a clay mineral developer of acid clay, activated clay, etc.

Description

[Detailed description of the invention] This paper relates to improvements in pressure-sensitive copying paper using physical toners.

Pressure-sensitive copying paper is disclosed, for example, in U.S. Pat.
No. 07, No. 2,730,465, etc., and is known as a microcapsule containing a solution of an almost colorless electron-donating dye (hereinafter referred to as a coloring agent), an electron-withdrawing substance ( This method utilizes the coloring reaction that occurs between the color developer and the color developer (hereinafter referred to as a color developer).

Examples of the color developer include natural or synthetic clay mineral-based inorganic color developers such as acid clay, activated clay, attapulgite, and zeolite, and organic acid-based color developers such as special phenolic resins or substituted salicylic acid compounds. It is used.

Among these, clay mineral-based inorganic color developers have been widely used since the early stages of pressure-sensitive copying paper, and are still widely used today as a result of various technological improvements. however,
These clay mineral color developers instantly color triphenylmethane phthalide dyes such as crystal violet lactone (hereinafter abbreviated as OVL) and malachite green lactone, but the fastness of the colored image is extremely poor; It is well known that the color density is maintained by using benzoylleucomethylene blue as a so-called secondary coloring agent. However, the hue of the image that gradually develops with benzoyl leucomethylene blue is pale green, and the hue of the image that develops gradually is pale green.For example, the hue of the image that develops is completely different from the blue-purple color image of crystal violet lactone. It turns green when exposed to
This has a major problem in that the hue cannot be maintained during color development, and there is a strong need for improvement.

Although various proposals have been made to improve the problems of pressure-sensitive copying paper using clay mineral color developers, no fundamental solution has yet been found.

For example, (1) Special Publication No. 48-36209, No. 48-3
No. 3210 discloses that clay minerals are combined with 1 to 10 parts of a phenol compound, such as 4,4'-isopropylidenediphenol, p-phenylphenol, p-cresol, methylene-bis(phenylenephenol), etc. In addition, (2) a method of adding an IF nitric acid compound in Japanese Patent Publications No. 50-16965 and No. 51-15777, and (b) a method of adding a cyanamide compound in Japanese Patent Publication No. 50-16968, etc. Two methods have been proposed for improving the stability of colored images, but their improvement effects have not yet been sufficient.

For example, in the method (1) above, the color image of the OVT is stabilized and the blue-violet color can be maintained for a long period of time, but the yellowing behavior of the pressure-sensitive paper surface becomes significant and it is difficult to store it indoors. Due to these conditions, the paper surface gradually turned yellow, making it impossible to put it to practical use.

The present inventors have conducted intensive studies on improving the performance of pressure-sensitive copying paper using these clay mineral-based color developers, and have found that lactone-based dyes such as phthalide or fluoran-based dyes and general Methine dye of formula (1) (wherein, Amino group, substituted amine group, lower alkyl group, cycloalkyl group, lower alkoxy group, (1 represents a haloalkyl group, halogen atom, lower alkoxy group, R7-R8 represents a hydrogen atom, halogen atom, lower alkoxy group, bond When a 2,6-disubstituted phenol derivative is coexisted with a layer containing a clay mineral compound as a color developer, an extremely deep color develops. The team discovered that it is possible to obtain a pressure-sensitive copying paper that exhibits little change in color image density and hue over time and also has excellent light fastness of the sheet containing a color developer layer, and has thus arrived at the present invention.

That is, in the present invention, in order to stabilize blue colored images using pressure-sensitive copying paper using a clay mineral color developer, especially OVT, as the main color developer, Instead of benzoylleucomethylene blue as a secondary color former, methine dyes of IZ formula (1), especially
O selected from substituted aminotriphenylmethane derivatives
By using a dye with a color similar to 441 for VL, OV
A color image of the same hue as the color image of L is gradually developed on the color developer-coated paper surface, and then 2,6
By adding and using mono-di-converted phenol derivatives,
Significantly improves the density and hue stability of colored images of lactone dyes and methine dyes.

That is, the present invention has excellent light yellowing resistance for uncolored paper,
When color is developed, it shows an attractive color density, and there is no change in the hue of the color image, and it has excellent storage stability and light stability.
The present invention provides an overall excellent pressure-sensitive copying paper with excellent yellowing resistance.

In order to stabilize these colored images, lactone-based dyes and methine-based dyes must be selected appropriately, not only for pressure-sensitive copying paper that develops blue color, but also for pressure-sensitive copying paper that develops various hues such as black, green, and red. It is also possible by

In the present invention, the lactone dye refers to a generally known compound, for example, the general formula (11) (where a, b,
c and d represent carbon atoms, one or two of which may be nitrogen atoms. The carbon atom may have a substituent attached to it, a-1), b-c or c-d
The bonds may also form other aromatic rings. In addition, X and Y represent a phenyl group, a naphthyl group, or an aromatic heterocyclic residue, which may have a substituent, and may be the same or different, and X and Y may be bonded together. It is a lactone dye represented by (may form a ring). In general,
(A) Phthalide dye, (■3) Fluoran dye, (
0) Includes a group of compounds called azaphthalide dyes, particularly phthalide dyes such as triphenylmethane phthalides and indolyl phthalides, that is, compounds of the general formula (IIn, (wherein R] to R4) is a lower alkyl group, and Y is a hydrogen atom or an alkyl-substituted amine group); Indolyl phthalide dyes represented by (representing a group) are often used.

Representative specific compounds include ro, 3-bis-(4/-
dimethylaminophenyl) phthalide, 3,3-his-(
4-dimethylaminophenyl)-6-dimethylaminophenyl phthalide, 3-(1'-ethyl-2'-methyl-
Indole-37-,yl)-ro-(4'-dimethylaminophenyl)phthalide, 3-diethylamino-6-methyl-7-anilinofluorane, Ro-diethylamine-
7,8-benzofluorane, ro-diethylamino-7-
dipendylaminofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 6-diethylamino-
Examples include 6-chlorofu-anilinofluorane and 3-(2'-ethoxy-47-diethylamino)-ro-(1'-ethyl-27-methyl-indol-5-yl)-4-azaphthalide.

Specific examples of the methine dye represented by the general formula (1) include the following compounds.

(A) As a triaminotriphenylmethane dye, 4
, 4.4"-tris-dimethylamino-triphenylmethane, 4,4'-bis-dimethylamino-4"-dimethylaminotriphenylmethane, 4-N-benzyl-N-
Methylamino-4/,4//-bis-dimethylaminotriphenylmethane, 4,4'-bis-diethylamino-
4"-dimethylamine-triphenylmethane, 4.4'
-bis-ethylamino-3,3'-dimethyl-4"-dimethylamino-triphenylmethane, 4,4'-bis-
Dimethylamino-3-methyl-4-ethylamino-
Triphenylmethane 1. '1.4'-bis-dimethylamino-4-methylamino-triphenylmethane, 4.
4'-bis-molporino 4//, ymethylamino-triphenylmethane, 4.4', 4''-tI),
<,) ethylamino-triphenylmethane, 4.4'-
Bis-N-benzylamino-5,6'-dimethyl-47
-dimethylamine triphenylmethane, 4,4'-bis-(N-p-chlorobenzyl-N-methyl)-4"-
Dimethylamino-triphenylmethane, 4,4'-bis-dimethylamino-4//N-benzyl-N-methylamino-triphenylmethane.

(B) As a diamino-triphenylmethane dye, 4
．． 4'-bis-dimethylamine-triphenylmethane,
4,4'-bis-dimethylamino-4"-methyl-triphenylmethane, 4,4'-bis-dimethylamine-3
7-Methyl-4"-methoxotriphenylmethane, 4
, 4'-bis-dimethylamine-5// , 4//-
Dimethoxy-triphenylmethane, 4.4'-bis-diethylaminolo"-ethyl-4"-ethoxy-triphenylmethane, 4.4'-bis-methylamino/ =3.
3'-dimethyl-3"-butyl-4"-ethoxy-triphenylmethane, 4.4'-bis=(N-benzyl-N
-methylamino) 3//-methyl-47-nitoxytriphenylmethane, 4,4'-bis-N-hyrolidyl-6"-methyl-4"-methoxy-triphenylmethane, etc., (0) monoamino-triphenylmethane, etc. As a phenylmethane dye,
4.4'-dimethoxy-4"-dimethylamino-triphenylmethane, 4.4'-dimethoxy-6"-methyl-
4"-ethylaminotriphenylmethane, 3,3'-dimethyl-4,4'-dimethoxy-4"-dimethylamino-triphenylmethane, 4,4'-dimethoxy-4"-
(D) naphthyldiphenylmethane dyes such as pyrrolidino-triphenylmethane; 1'methane, bis(4-dimethylaminophenyl)-4'-N-phenylaminenaphthyl-17-methane, bis(4-dimethylaminophenyl)
4/-dimethylaminonaphthyl-17-methane, (I
ii) As a diphenyl-β-styrylmethane dye,
Bis(4-dimethylaminophenyl)-β-styrylmethane, bis(3-methyl-4[N-phenylamino]phenyl)-β-styrylmethane, bis(4-dimethylaminophenyl)-β-(4/- dimethylaminostyrylmethane), bis(4-dimethylaminophenyl)-β-
(3'-Mef-4'ethoxystyryl)methane, etc. (P) X in general formula (1) is a methine dye that forms a heterocycle, bis(4-dimethylaminophenyl)
i lysylmethane, bis(3-methyl-4-diethylaminophenyl) 2/5/-biradylmethane,
Bis(4-N-dibenzylaminophenyl)2/ 4/
-pyrimidylmethane, bis-(6-methyl-4[N-
Methyl-N-benzyl]phenyl)-1'-ethyl-2
(G) Other methine dyes in which 3 and R4 of the general formula (1) form a ring include 3,6-bis-dimethylami2-9-phenylxanthine, 6,6-bis-(N-methyl-N-phenylamino)-q-(s;4'-dimethoxyphenyl)xanthine, ro, 6-bis-dimethylamino-9-phenylthioxanthine, ro, 6-dimethylamino q-(4'-methoxyphenyl)-10-
Methyl-9,10-dihydroacridine and the following methine dyes can be used, but of course the present invention is not limited to these exemplified compounds.

The methine dyes of general formula (1) above are generally unstable upon storage, and when applied to pressure-sensitive copying paper, the oxidized color development of each dye may occur during microencapsulation or the microcapsule-coated paper. Since the methine dye has a tendency to become colored, if necessary, the methine dye is stabilized on the paper surface by containing an alkanolamine and/or a sequestering agent in the dye microcapsule layer.

The alkanolamine used has the general formula (V) biR'-N-4--OH(V) (wherein R represents a lower alkylene group, a hydroxyalkylene group or a poly(oxyalkylene) group, and , W is a hydrogen atom, an alkyl group, a hydroxyalkyl group,
represents a lower alkyl ether of an aryl group, an aralkyl group, an acyl group, a /-hydroxyalkylpolyoxyalkylene group, or a /-hydroxyalkylpolyoxyalkylene group, and Bi and V may be combined to form a ring). The represented compounds include, for example, (1) alkanolamines having a tertiary amine group, tris-N-(2-hydroxyethyl)amine,
Tris-N-(2-hydroxypropyl)amine, Tris-N-(3-hydroxypropyl)amine, N-methyl-N-phenyl-N-(2-hydroxyethylamine), N-acetyl-N,N-di (2-hydroxyethyl)amine, N-hydroxyethylmorpholine, tris-
N(,1-hydroxyethyl-polyoxyethylene)amine, N,N'-bis(2-hydroxypropyl)piperazine, etc. (2) As alkanolamines having a secondary amino group, N,N-di(2 -hydroxyethyl)amine, N,
(l) Alkanols having a primary amine group, such as N-di(2-hydroxypropyl)amine, N-methyl-N-(2-hydroxyethyl)amine, N-acetyl-N-(2-hydroxypropyl)amine, etc. As amines, N-(2-hydroxypropyl)amine, N-(
Examples include 2,3-dihydroxyglopyl)amine and N-(2-hydroxy-ro-aminopropyl)amine.

Among these, alkanolamines having a quaternary amino group and compounds having a temperature of 250°C or higher are preferred.

In addition, as metal ion sequestering agents, ethylenediaminetet-yell, N-hydroxyethyl-ethylenediamine-N, Nζζ-mer triacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminepentaacetic acid, nitrilotriacetic acid, N-hydroxyethyl-iminodiacid, glycol ether Organic water-soluble sequestering agents such as diaminetetraacetic acid, tartaric acid, citric acid, gluconic acid, lignin sulfonic acid, polyacrylic acid and their alkali metal salts, sodium tripolyphosphate, sodium polymetaphosphate, sodium pyrophosphate, etc. Examples include polymerized phosphates.

The alkanolamine used in the microcapsule layer is 1-1 parts by weight per 100 parts by weight of the methine dye used.
0,000 parts by weight, preferably 200 to 2,000 parts by weight.

The amount of the metal ion sequestering agent used is 01 to 1000 parts by weight per 100 parts by weight of the total amount of the used (lactone dye, notin dye), and usually 100 parts by weight or less is sufficient.

These metal ion sequestering agents and alkanolamines may be (1) added prior to microcapsule membrane formation, or (2) may be added and mixed to the microcapsule liquid after the encapsulation process, and may be added to (3) aqueous coating solution for pressure-sensitive copying paper (mixing composition with microcapsules, stilts, adhesives, etc.).

From the viewpoint of coloring suppression effect and economical efficiency, it is preferable to add the microcapsule liquid in step (1) or (2). When adding an excessive amount of sequestering agents or alkanolamines before microcapsulation, depending on the encapsulation method, they may react with reactive components (monomers) in the system or cause damage to the system forming microcapsules. Since the equilibrium may be shifted and microencapsulation inhibition may occur, it is preferable to select the timing of addition depending on the microencapsulation method (°C).

In addition, as clay mineral color developers, natural and synthetic clay inorganic compounds such as acid clay, activated clay obtained by acid treatment of acid clay, bentonite, attapulgite, and zeolite are used. The activated clay obtained in this manner is suitable as the clay mineral color developer of the present invention.

These activated clays have both acid sites that can instantly color lactone dyes such as phthalide and fluoran, and oxidation points that can turn methine dyes of general formula (1) into oxidized colored images. Therefore, it is suitable as a clay mineral color developer of the present invention.

In the present invention, 2 coexisting as a clay mineral color developer
, 6-disubstituted phenol derivative, for example, 1, 3.5
- trimethyl-2,4,6-)lis(3/s/-seam41.-phthyl-4'-hydroxybenzyl)
Benzene, 1.3.5-) Lis(3/5/-Diemlesupty-4'-hydroxyphenyl)isocyanurate, Octadecyl-ro-(Roζ5'-DiLe, J
-butyl-4'-hydroxyphenyl) flobionate, 6-(4'-oxy-3(5'-seimun, er-butylanilino)-2,4-bis-(n-octylthio)1
, 3.5-) riazine, (4-oxy-6,5-seam 41-butylbenzyl) phosphate/l/, 4.4'
-methylenebis-(2,6-cyLbd-butylphenol), 2,2-bis(ro15!-seam-butyl-4'-hydroxyphenyl)furopane, tetrakis-[
Methylene-(ro,5-di-4.1-butyl-4-hydroxyphenyl)gropionate]methane, 1,1.3
-) lis-(3/s/-m4zobutylphenyl)phthane, 1,6-hexanethiol bis[3-(riζ57-dimu 1.l-butyl-4'-hydroxyphenyl)gropione-1 Examples include, but are not limited to, -1N, N'-hexamethylene-bis-(ro, 5-seam-subbutyl-4-bitroxyhydrocinnamamide), and the like.

Among these 2,6-di-substituted phenol derivatives,
In particular, 2,6-dialkyl-4-aminephenol derivatives, namely 1,3,5- -(n-octylthio)=1.
3.5-) Reazine and the like are preferred.

The amount of these 2,6-disubstituted phenol visitors used is 1 to 50 parts by weight per 100 parts by weight of the clay mineral color developer, and the preferred amount is 2 to 20 parts by weight.

These 2,6-di-substituted phenol derivatives have been prepared in advance by
Typically, but not exclusively, used as a wet-milled aqueous suspension with a clay mineral developer in the presence of a dispersant, surfactant or protective colloid. isn't it.

The pressure-sensitive copying paper of the present invention is generally used for pressure-sensitive copying as follows.
It is composed of a combination of 8 papers and OF paper. That is, 08 paper for pressure-sensitive copying is made by adding cellulose powder, cellulose powder, and a microcapsule solution of a hydrophobic solvent containing a lactone dye and a methine dye to which an alkanolamine and/or a sequestering agent have been added using a known microencapsulation method. Stilt a for preventing contamination of pulp powder, starch particles, talc, clay, polystyrene resin beads, etc., and polyvinyl alcohol, OK [4i1J! A coating liquid prepared by mixing water-bathable polymeric adhesives such as powder 'lA, carboxyl cellulose, casein, etc. to have appropriate clay, coating suitability, or alkanolamines and/or sequestering metal ions. In addition to stain-preventing stilts and adhesives, alkanolamines and/or sequestering agents are added to the pigment microcapsule liquid that does not contain agents to create a coating liquid that has suitable clay and coating suitability. , obtained by coating on paper.

02 paper for pressure-sensitive copying paper is prepared by mixing the above-mentioned clay mineral color developer and 2,6-disubstituted phenol derivative with pigments, adhesives, dispersants, various additives, etc. by a known method. After being dispersed, it is made into a water-based or oil-based paint, which is given clay and rheology properties depending on the coating method, and then coated with a knife coater.
Grade coater, percoater τ It can be obtained by coating on paper using a roll coater or by printing on paper using a gravure printing method, a flexo printing method, etc.

The present invention will be explained below with reference to Examples.

Examples 1 to 4 and Comparative Examples 1 to 4 a) FF construction of microcapsules containing a color former.

100 g of the following dye solutions (A) to (E) and 200 g of an acid-treated gelatin 10 aqueous solution are emulsified at 50°C until the average particle size becomes 4 to 5 μη. 142 g of a 7% carboxymethyl cellulose aqueous solution was added to the emulsion, and further 290 g of 50 uO hot water was added to dilute the emulsion, and the acid resistance was adjusted to pII of 41 to form a coacel pension. Subsequently, while stirring, the liquid temperature was cooled to 10'O to gel the coacervate film.

Furthermore, 20 parts of 37% formalin was added, and a 10% caustic soda aqueous solution was gradually added dropwise to adjust the pH to 105 to harden the coacervate film.Then, the temperature of the solution was further raised to 40°C, and then allowed to cool to room temperature and microcoated. Obtain capsule liquid.

(A) Ro, 3-bis(4'-dimethylaminophenyl)
-6-dimethylaminophthalide (OVL) 3wt% and phenylxylylethane in which 7J 4.4'-bis-diethylamino-4''-dimethylaminotriphenylmethane 1.5W1% was dissolved, (B) cvL3wt% , 4.4? 4"-tris-dimethylaminotriphenylmethane 1 wt%, bis(4-
dimethylaminophenyl) -4/-naphthyl-1'-
Diisopropylnaphthalene with 0.5 wt% of methane dissolved in it, (0) Phenylxylylethane with 3 wt% of OVT and 1.5 wt% of benzoylleucomethylene blue (BLMB) dissolved in it, (D) 3-N-cyclohexyl-N-methyl Phenylxylylethane dissolved in 4 wt% amino-6-methyl-7-anilite fluorane and 15W hiss(4-dimethylaminophenyl)-β-styryl-methane, (E) 3-N-cyclohexyl-N- methylamino-
Phenylxylylethane in which 5 wt% of 6-methyl-7-anirithufluorane is dissolved; b) Preparation of a+B paper 5 parts by weight of wheat starch granules with an average particle size of 15 μm are added to each of the microcapsule liquid prepared in a). and 5 parts by weight of 20% oxidized starch solution, further (A), (B),
Or for the dye-containing microcapsules (D),
An aqueous coating solution obtained by thoroughly mixing Tris-N=(2-hydroxyethyl)amine 1 and Kurabe was coated on 3 high-quality paper-H so that the dry coating amount was 6 g/nr and dried to prepare pressure-sensitive copying paper. (08 paper) was created.

C) Preparation of OF paper (developer coated sheet) (I) Water 200
．． Add 1 g of sodium hexametaphosphate and activated clay (Mizusawa Chemical "Jilton") iooy to 9, and add 20% NaOH.
Add an aqueous solution to neutralize until the pH reaches 70, and then
-(4'-oxy-315'-diiknobutylanilino) -2,4-bis(n-octylthio)1,3.
20 g of a 30% aqueous dispersion of 5-triazine (previously dispersed into fine particles in the presence of an anionic surfactant) and a 20% oxidized starch aqueous solution IJj9
and SBR Latex 34.9, and while stirring well, apply this coating solution prepared with 20% NaoI (pi) to 98 on base paper of 5CJg/d so that the solid content becomes Bg/nf. was coated with a Meyer bar to obtain pressure-sensitive copying paper (OF paper).

(1) 6-(4'-Oxita5'-Siemunzobutylanilino)-2,4-bis(n-octylthio)1.
3.5-) Instead of riazine, a 40% aqueous dispersion of 1,3,5-1-lith4 (3/5/-subbutyl-4-hydroxyphenyl) isocyanurate was added to pressure-sensitive copying paper. (OF paper) was obtained.

(III)1. ro, 5-tris (3/s/-seam 4
No. 1, except that 25 g of a 40 aqueous dispersion of 2,2-bis(4'-hydroxyphenyl)propane (bisphenol A) was used instead of i-butyl-4'-hydroxyphenyl) isocyanurate. Pressure-sensitive copying paper (OF paper) was obtained in the same manner as above.

(rV) Add 1 g of sodium hexametaphosphate and 100 g of activated clay (Mizusawa Chemical "Jilton") to 2 DJ9 water,
Add 20% NaOH aqueous solution to neutralize until I) II becomes 71, then add 5 g of 20% oxidized starch aqueous solution I and S
D It, add 34 g of latex and mix with 20% NaOH to give a PTF of 95. Apply the coating solution to 50.9/y on any cardboard with a solid content of 8 g.
/nf was coated with a Mayer bar and dried to obtain pressure-sensitive copying paper (OF paper).

d) Performance test of pressure-sensitive copying paper The following performance evaluation of the pressure-sensitive copying paper was carried out by combining the 08 paper and 02 paper obtained in b) and c) as shown in Table-1.

Color development rate 2 CB paper and 02 paper were stacked on top of each other with their coated surfaces facing each other, and then the paper was pressed to develop color using an electric typewriter.

The color development rate was expressed using a Hunter colorimeter (amber filter). AO: Reflectance of 02 paper before coloring Al: Reflectance of coloring surface after 20 hours of coloring The higher the coloring rate, the darker the color.

Colored image storage stability: ■ Colored 02 paper is placed in a carbon arc fetometer.
The degree of fading of the colored image was expressed by the color development rate after exposure for a certain period of time.

The higher the value, the darker the color remaining after the test.

■ Separately, colored paper was left indoors in a dark place for one month to examine the degree of natural fading tendency. The concentration after the test was expressed as a color development rate.

The storage stability mentioned above is accompanied by not only a decrease in the density of the colored image but also a change in hue, which is considered a drawback of pressure-sensitive copying paper using a clay mineral developer, so the various phases of the developed color are also shown after the test. did.

02 Yellowing of paper: Based on JIS L-1055 (Test method for nitrogen oxide gas fastness of dyed products and dyes), uncolored OF paper is exposed to nitrogen oxide gas in a sealed container for 50 minutes, and uncolored Examine the degree of yellowing on the coated surface of 02 paper that has been left indoors for one month out of direct sunlight. display).

The higher the value, the whiter the paper surface and less yellowing.

7 8 As is clear from the Examples and Comparative Examples, the pressure-sensitive copying paper of the present invention develops deep colors and has excellent storage stability (hue, density) of colored images and yellowing resistance. That is clear.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Scope of Claims] 1) A microcapsule layer of a dye composition containing a lactone dye and a methine dye represented by general formula (1) as essential components on the same or different supports, a clay mineral color developer, and A pressure-sensitive copying paper comprising a developer layer containing a 2,6-disubstituted phenol derivative. (In the formula, It represents an alkyl group, a cycloalkyl group, a lower alkoxy group, a lower haloalkyl group, a halogen atom, or a lower alkoxy group, and R7 and FLll represent a hydrogen atom, a halogen atom, or a lower alkoxy group, and may be combined to form a ring. 2) Claim 1, wherein the microcapsule layer of the dye composition containing a lactone dye and a methine dye represented by general formula (1) as essential components contains an alkanolamine and/or a sequestering agent. Pressure-sensitive copying paper as described in section. 3)2. The pressure-sensitive copying paper according to claim 1, wherein the S-disubstituted phenol derivative is a 2,6-dialkyl-4-amine phenol derivative.