JPH0267178A - Color self-developable type pressure-sensitive recording paper - Google Patents

Abstract

PURPOSE:To enhance developed color density without deteriorating developed color staining by providing an intermediate layer containing inorg. or org. pigment on a support and laminating a recording layer consisting of a microcapsule containing a color former and paint containing a coupler to said layer. CONSTITUTION:An intermediate layer containing inorg. and/or org. pigment is provided on a support and a monolithic recording layer consisting of a microcapsule containing a color former and paint containing a coupler is laminated to said intermediate layer to prepare color self-developable pressure-sensitive recording paper. As a concrete example of the inorg. pigment, there are calcium carbonate, talc, silica and barium sulfate and, as a concrete example of the org. pigment, there are polystyrene, polyvinyl toluene and a styrene/divinyl benzene copolymer all of which have melting temp. of 100 deg.C of higher. The coating amount of the intermediate layer is pref. 1-20g/m<2>.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to self-coloring pressure-sensitive recording paper, in which a pigment layer is provided between a support and a single self-coloring pressure-sensitive recording layer. This paper relates to self-coloring pressure-sensitive recording paper.

(Prior Art) Self-coloring pressure-sensitive recording paper is developed from so-called carbonless copying paper, and is also called self-contained paper. Its structure consists of a process of coating a support with a microcapsule paint containing a colorless compound (hereinafter referred to as a coloring agent) that has electron-donating properties, adsorption properties, and coloring reactivity, and A two-layer coating method consisting of two steps (the order of coating is reversed) due to the process of coating an electron-accepting substance (hereinafter referred to as a color developer) such as acid clay, phenolic resin, or organic acid substance on the layer. There are also known methods (Japanese Patent Publication No. 47-16091) in which the components of the above two steps, or one of them, are made into microcapsules, mixed uniformly, and coated in a single layer.

(Problems to be Solved by the Invention) Among the self-coloring pressure-sensitive recording papers of the above two methods, which have different manufacturing methods and coating layer configurations, the most different point is the @ structure on the coating layer surface.

In a two-layer laminated form, the "I!A" is applied on the surface with only one layer of color former or a color developer layer, or in the case of a two-layer form coated with a mixed liquid, it is a two-layer composition. The components are uniformly mixed, which has various advantages and disadvantages.

The advantage is that since the entire amount of the color forming agent and color developer are present in the vicinity of the phase q, it is easy to obtain a product with a strong color density. but,
This indicates that unintended colored stains are likely to occur due to friction during manufacturing or handling.

Self-coloring (blue pressure-sensitive recording paper is destined to have both the necessary coloring performance for practical use and unnecessary coloring stains, and has conventionally been designed to satisfy both contradictory characteristics v1 of coloring and staining. 3. It's a waste of effort, but...
Realistically, from the standpoint of product value, it is necessary to prevent unnecessary coloring stains (1-7), so it is necessary to prevent dissatisfaction by sacrificing the most necessary coloring performance. Real Vi is the only thing I've been able to get.

(Means for Solving the Problems) The purpose of the present invention is to obtain a high color density without aggravating unnecessary color stains, and a pigment layer ( It is characterized by the provision of an intermediate layer (hereinafter referred to as an intermediate layer).

The pigment used in this intermediate layer can be either an inorganic pigment or an organic pigment.
Refers to Plusbook fine powder with a melting temperature of about 0'C or higher.

Examples include polystyrene, polyvinyl 1-toluene, styrene-divinylbenzene copolymer, polymethyl methacrylate, urea-formaldehyde polymer, and the like.

Inorganic pigments refer to natural, semi-synthetic, and synthetic mineral substances that are substantially insoluble in water, such as calcium carbonate,
Taruri, silica, clay, filf2 baricum, barium carbonate, magnesium carbonate, magnesium citrate,
Examples include lead sulfate, lead white, sulfide II, satin white, titanium oxide, antimony oxide, mica, bentonite, calcium silicate, gypsum, aluminum hydroxide, and the like.

In addition, these inorganic pigments may be used alone, or two or more types may be used in various combinations.
The objectives of the invention can be achieved.

Among these pigments, JIS K5101 (face No. 31
The larger the oil absorption amount (according to test method), the easier it is to obtain a deep color density, but the color stains also become larger.

Furthermore, if the oil absorption is too small, the coloring density will not improve much, but the coloring stain will also decrease little.

From this, preferably 10 to 300 mff/100
It is best to wait for the oil absorption amount of 9, and more preferably 20.
The effect is very large when using ~150tml/100g of pigment.

These pigments are coated onto a support together with an adhesive;
Conventionally known adhesives can be used, such as proteins such as cavin and seratin, lerulose derivatives such as carboxymethylcellulose cellulose, and sucrose such as oxidized starch and esterified starch. Water-soluble natural polymer compounds, such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, styrene-butadiene latex, acrylonitrile-butadiene-acrylic acid latex, polyacrylamide, styrene-maleic anhydride co-consolidated compound, etc. Synthetic polymer compounds\b uratexes can be used.

In addition, auxiliary agents such as antifoaming agents and dispersants may be added as necessary.

The coating mass of this intermediate layer may be controlled depending on the required quality characteristics of the self-coloring pressure-sensitive recording paper to be obtained, and is preferably 1 to 20 g/m.

The coating method is not particularly limited, or any method used by those skilled in the art can be used. For example, there are various coating methods such as air knife, blade, roll, rubber doctor, curtain, rod, flexo, and gravure.

Regarding the self-coloring pressure-sensitive recording layer that can be used in the present invention,
There are no particular restrictions; conventionally known materials may be used.

For example, the microcarcelization method, the microcapsule wall + A, color former At) dissolving the color former - (J oil), or color developer, adhesive, capsule protectant, etc.

Mike['] cabrelization method is =1 acervation method (as disclosed in US 'I! f812800458, etc.);
The interface method (Japanese Patent Publication No. 171763, etc.), the in-length method (Japanese Patent Application Laid-Open No. 51-9079, etc.), etc. can be used.

? Microphone [1 capsule wall + Δ includes polyurethane, polyDR cord, epoxy resin, urea-formalin resin,
Melamine-formalin resin etc. can be used.

As the color former, triallylmethane compounds, diarylmethane compounds, xanthine compounds, masuazine compounds, spiropyran compounds, etc. can be used.

The oil that dissolves the coloring agent is diarylalkane,
Aromatic synthetic oils such as alkylnaphthalenes, alkylated biphenyls, and hydrogenated terphenyls, aliphatic synthetic oils such as kerosene, naphtha, paraffin oil, and chlorinated paraffins, vegetable oils such as cottonseed oil, soybean oil, and linseed oil can be used. .

As a protective agent for microcapsules, cellulose powder,
Starch particles, talc, calcined kaolin, calcium carbonate, etc. can be used.

Color developers include clays (e.g. acid clay, attapulgite, etc.), organic acids (e.g. aromatic carboxy compounds such as salicylic acid or metal salts thereof), mixtures of organic acids and metal compounds, acidic polymers (e.g. phenol). −
(formaldehyde resin, salicylic acid resin, metal salts thereof, etc.) can be used.

As the adhesive, the same adhesive as that used for the intermediate layer can be used.

For example, proteins, cellulose derivatives, sucrose,
Latexes, water-soluble synthetic polymer compounds, etc.

(Function) The self-coloring pressure-sensitive recording paper of the present invention provides a high coloring density and at the same time produces less unnecessary coloring stains.

The reason for this is that when the microcapsules are destroyed by the confining pressure of a typewriter, etc., the coloring agent and oil contained therein are absorbed by the face 4'4 of the intermediate layer between the support and the self-coloring type. This is probably because the color former and color developer in the pressure-sensitive recording layer are used efficiently.

Also, unlike a typewriter, unnecessary colored stains are caused by extremely weak forces such as friction, so the surface of the coating layer has a large effect, and the presence or absence of an intermediate layer has little to do with it.

Therefore, colored stains are not worsened even if there is an intermediate layer.

For these reasons, the self-coloring pressure-sensitive recording paper of the present invention has a higher color density than the conventional paper without an intermediate layer, even though it has the same self-coloring pressure-sensitive recording layer, and is free from color stains. An excellent self-coloring pressure-sensitive recording paper with no observed deterioration can be obtained.

(Examples) Hereinafter, specific examples of the present invention will be described, but the present invention is not limited only to these descriptions. The following (parts) represent parts by weight.

Example 1 Zinc oxide (made by Sakai Chemical Industry 0 Vermilion, zinc oxide No. 1 special oil absorption ff
112.5 m1/100 g>50 parts were dispersed in 50 parts of water with 0.2 part of sodium hexametaphosphate.

Thereto, 60 parts of a 10% oxidized starch aqueous solution was added and thoroughly stirred to obtain an intermediate paint.

The coloring agent-containing microcapsules used in the self-coloring pressure-sensitive recording layer are made by mixing 10 parts of crystal violet lactone with 90 parts of Hysol SAS N-296 (manufactured by Nippon Petrochemical Co., Ltd.).
The mixture was heated and dissolved to obtain an internal phase oil.

10 parts of melamine and 25 parts of 37% formalin were heated together with 100 parts of water at pH 8 to obtain an initial polycondensate of melamine-formalin. Next, the internal phase oil was emulsified in 150 parts of a 5% styrene-maleic anhydride copolymer aqueous solution, and the above-described melamine-formalin condensate was added to this emulsion to adjust the pH of the system to 5.6. While maintaining the temperature, the liquid temperature was maintained at 70'C for 2 hours to obtain a microcapsule dispersion containing a coloring agent and having a melamine-formalin resin film.

The average particle size of the obtained Microcabuvir was 4 microns. A coating for a self-coloring pressure-sensitive recording layer was prepared using the following formulation. The units are dry small parts.

Microcapsules containing a color former 100 parts Color developer (Sumitomo Dells (TAI PR26298) 50 parts Denzon particles 300 parts Kaolin clay 70 parts Oxidized starch
100 copiesNext, to create self-coloring pressure-sensitive recording paper, coat 40 (g/'rrt) high-quality paper with paint for the intermediate layer so that the coating amount is 10 (3/min). It was applied and dried using a rondo.

On this intermediate layer, a self-coloring pressure-sensitive recording layer having the above-mentioned composition was coated at a density of 8 (g/m>) to prepare a self-coloring pressure-sensitive recording paper.

Example 2 A self-coloring pressure-sensitive recording paper (7) was prepared in the same manner as in Example 1, except that titanium oxide (R650, manufactured by Sakai Kagaku Kogyo U, 20-22 weight/100 g) was used as the intermediate layer pigment.

Example 3 A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 1, except that aluminum hydroxide (Hisilite H-32 manufactured by Showa Denko 11, oil absorption 23 mff/1003) was used as the intermediate layer pigment.

Example 4 Kaolin clay (Thele Ka, USA) as intermediate layer pigment
Oin Co, M Kaobrite Oil absorption 37.2ml
A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 1, except that 1/100 g) was used.

Example 5 Intermediate layer pigment with talc (manufactured by Fukuoka Talc Kogyo ■, oil absorbing ff1)
A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 1 except for the position used.

Example 6 A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 1, except that calcium carbonate (Shiraishi T-Gyo Co., Ltd., Hakuenka P7, oil absorption: 47 m/100 g) was used for the intermediate layer face 1'81.

Example 7 Calcium carbonate (Okutama Kogyo (Taisei Tamavar-cho P123 oil absorption fit 127rd!/100) was used as the intermediate layer pigment.
A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 1 except that 9) was used.

Example 8 A self-coloring pressure-sensitive recording paper was prepared in the same manner as in Example 1 except that silica powder (Mizusawa Chemical Industry Co., Ltd. (Mizusawa Kagaku Kogyo Co., Ltd. (Mizusawa Kagaku Kogyo Co., Ltd. (Mizusawa Kagaku Kogyo Co., Ltd. Mizukasil P-527 Oil Absorption FF 1160ml/100g)) was used as the intermediate layer pigment.
It's G.

Example 9 Silica powder for intermediate layer pigment (Fuji Davison Illoit 7)
2 Oil absorption ff1210rrl! A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 1, except that .

Example 10 A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 1, except that a urea-formalin resin (Pergopack M-2 oil absorbent 295 ml/100 g, manufactured by Ciba Kaigy Co., Ltd.) was used as the intermediate layer pigment.

Example 11 Inorganic solid acid as color developer Jilton 5S- manufactured by Mizusawa Chemical Industry ■
A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 6 except that 1> was used.

Example 12 A self-coloring pressure-sensitive recording paper was obtained in the same manner as in Example 6 except that 3,5-di(α-methylbenzyl)tonalicylic acid zinc salt was used as the color developer.

Comparative Example 1 A self-coloring pressure-sensitive recording paper of Example 6 without an intermediate layer was prepared.

Comparative Example 2 A self-coloring pressure-sensitive recording paper of Example 11 without an intermediate layer was prepared.

Comparative Example 3 A self-coloring pressure-sensitive recording paper without the intermediate layer of Example 12 was prepared.

Test specimens were prepared by cutting 15 types of self-coloring pressure-sensitive recording papers prepared based on the above Examples and Comparative Examples into pieces approximately 5 cm wide and 10 cm long and arranging them in a C-row.

The test piece was covered with a piece of -L trade paper, and a ruler was applied to it and a ballpoint pen was used to write on the test piece at once so that all the test pieces were colored.

As a result, no matter how the test pieces were rearranged, there was a clear difference between those with and without the intermediate layer, and those with the intermediate layer had better insulation and color development.

Furthermore, it was obvious at a glance that even in those with an intermediate layer, as the oil absorption ω of the pigment in the intermediate layer increased, the color density also became deeper.

Colored stains were determined by visual inspection of friction stains when a pressure point of 300 g/cti was applied to each test piece and the fingertips were strained.
JJ was established.

As a result, almost no colored stains were observed in all the test pieces.

However, in the case where a pigment with a high oil absorption level was used in the intermediate layer, color staining occurred, although only slightly.

Table 1 summarizes the test results, and evaluation of color development and friction staining was performed using a 5-point method. A larger value indicates better characteristics.

That is, the coloring property is 5 (dark) (f) 1 (light) friction stain 5 (no stain) < +1 (stain), and a rating of 4 or higher indicates that there is no difference in practical use.

(Margins below) (Table 1) (Effects of the invention) As is clear from the examples, the self-coloring pressure-sensitive recording paper of the present invention has a low coloring cIf without worsening coloring stains.
was obtained, which was extremely useful in practice, and was sufficient to dispel the image of self-coloring pressure-sensitive recording paper that only a thin coloring density could be obtained.

Procedure Shinbo Seisho (spontaneous) April 20, 1999

Claims (2)

[Claims] (1) In a self-coloring pressure-sensitive recording paper in which microcapsules containing a color former and a paint containing a color developer are formed into a single recording layer on the same side of the support, the support and recording A self-coloring pressure-sensitive recording paper, characterized in that an intermediate layer containing an inorganic and/or organic pigment is provided between the layers. (2) The pigment in the intermediate layer has an oil absorption amount of 10 ml/100 g to 300 m as specified by JIS K5101 (pigment test method).
The self-coloring pressure-sensitive recording paper according to claim 1, which has a coloring density of 1/100g.