JPS6183093A - Coating composition for pressure-sensitive copy paper - Google Patents

Abstract

PURPOSE:To enhance color forming property, hue stability and printability, by containing a specific amount of an ammonium salt in a coating composition for pressure-sensitive copy paper based on pigment containing fine calcium carbonate, a coupler and an adhesive. CONSTITUTION:0.1-7.0pts.wt. of an ammonium salt such as ammonium nitrate or ammonium chloride is added to 100pts.wt. of the pigment of the coating composition for pressure-sensitive copy paper. As the pigment, one containing 30wt% or more fine particlulate calcium carbonate with a particle size of 0.5mum or less is used. As the coupler, an org. type such as a phenol resin is pref. and used in an amount of 10-35pts.wt. per 100pts.wt. of the pigment. As an adhesive, copolymer latex, which is prepared by copolymerizing aliphatic conjugated diene, ethylenic unsaturated carboxylic acid and other ethylenic unsaturated compound and has an average particle size of 0.04-0.09mum and toluene insolubility of 70-90wt%, is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a coating composition for pressure-sensitive copying paper having high sensitivity.

[Conventional technology]

In general, pressure-sensitive copying paper consists of three sheets: top paper, middle paper, and bottom paper.The back sides of the top paper and middle paper are coated with a micro-encapsulated coloring agent, and the surfaces of the middle paper and bottom paper are coated with a color-forming agent. is coated with a color developer. Then, when mechanical or impact pressure is applied to the surface of the top paper by a writing instrument, typewriter, or various other mechanical printers, the microcapsules on the back side of the clay paper and inner paper are destroyed, and the capsules are destroyed. The internal coloring agent transfers to the coloring agent on the surface of the middle paper and the lower paper to develop color, and a cutting record is achieved.

Other types of pressure-sensitive copying paper include those in which a microencapsulated color former and color developer are mixed or coated in one layer on the same surface of the base paper; Type that contains color developer, H
Types of partial printing using micro-encapsulated color formers or color developers, etc.
Various types of pressure-sensitive copying paper have been put into practical use depending on the purpose.

The general performance required for such pressure-sensitive copying paper is as follows:
(1) Fast color development speed, (2) High color density, (31) Good color stability after color development, (41) Excellent color resistance, storage stability, chemical resistance, and water resistance after color development. Being in good condition is disappointing.

Conventional pressure-sensitive copying paper uses acid clay,
Pressure-sensitive copying paper using all of these color-promoting agents may have used clay-based materials such as activated white clay, but while it has excellent performance such as fast color development speed and high color density, Is it a disadvantage that the color stability, water resistance, and printability of mapping are not good? I'm doing M.

Therefore, in order to overcome this drawback, a method has been proposed in which a shoulder type color developer such as an oil-soluble phenol resin or an oil-soluble salicylic acid glass conductor is used in place of the clay type color developer. Is this Miso color developer? The coating composition used has a suitable coloring performance even with a small number of coatings, good color stability of copied images, excellent water resistance, good coating properties, and printability. Although it has the characteristics of good color and matte color, it has the disadvantage that the color development speed is slow and therefore it takes a long time to form a stable copy image with the desired color development.

[Problem that the invention seeks to solve]

The present invention has been made against the above-mentioned background, and its purpose is to provide pressure-sensitive copying paper that has excellent color development and color tone stability of copied images, as well as excellent water resistance and printability. It is an object of the present invention to provide a coating composition for pressure-sensitive copying paper that can be obtained and has good coating properties.

[Means for solving the problem] The coating composition for pressure-sensitive copying paper of the present invention is characterized by: a containing finely particulate calcium carbonate having an average particle size of 0.5 μm or less on a 30-weight plate; 1. A coating composition for pressure-sensitive copying paper, the main components of which are a U colorant, an M colorant, and an M coloring agent.

The composition contains at least 1 m of ammonium salt, which is equivalent to 0.1 to 7 parts per 100 parts of the pigment.

Furthermore, the coating composition for pressure-sensitive copying paper of the present invention is characterized by containing at least 30 Nm1 of finely divided calcium carbonate with an average particle size of 0.5 μm or less, a color developer, an adhesive, and C. at least 1 m of ammonium salt corresponding to about 0.1-40 parts by weight per 100 parts by weight of said pigment.

ii J Adhesive Adhesive The following monomer components [Yes] Conjugated diene 30-60 C
Ethylene-based fukiwa Karun enemy 2-15 nail amount 0
A copolymer latex obtained by combining 30 to 60 x Etele/based unsaturated compounds other than is 70 to 901 t%.

The present invention will be explained in detail below.

The coating composition of the present invention mainly contains a pigment containing a relatively high proportion of fine charcoal calcium, a color developer, and particularly a color developer made of an organic compound (hereinafter referred to as "stone thread color developer"). An adhesive consisting of a color developer, at least one ammonium salt used in a specific ratio to the above-mentioned colorant, an additive added as necessary, a copolymer latex, etc. The most distinctive feature is the use of ammonium salts as a component.

Examples of the ammonium salt include nitrate ammonium, ammonium chloride, and partial eU ammonium.

Ammonium chromate, the enemy ammonium thio.

Examples include ammonium in the return ridge water system.

These can be used alone or in combination of two or more. 1 addition of ammonium salt -m.

0.1 to 7.0 parts by weight per 100 parts by weight of the pigment, preferably L < 0.2 to 5.0 parts by weight. If the amount of ammonium salt is less than 0.91 parts by weight, the coloring speed cannot be sufficiently increased, and - the amount of labor is 7.0% by weight.
If it exceeds NN, the ammonium salt acts on the base paper and reduces its strength, which is not preferable.

In addition, when using an ammonium salt in the state of an aqueous solution, it is used after adjusting the pH to 7.0 or more with aqueous ammonia.

Such ammonium salts greatly contribute to an increase in color development speed, color stability of copied images, and improvement in color density.

The pigment contains 300 parts by weight or more, preferably 50 parts by weight or more, of finely divided calcium carbonate having an average particle size of 0.5 μm or less. If the ratio of this calcium carbonate to the pigment is less than 30% by weight, or if the average particle size of the calcium carbonate exceeds 0.5 μm, the whiteness and color development of the resulting pressure-sensitive copying paper will deteriorate. It's not good because it's lowered. The type of calcium carbonate is not particularly limited, and examples include heavy moxibustion cal/wam, shen 11i! Dissolved calcium carbonate? You can use C.

8. The average particle size of calcium carbonate is measured using a constant pressure aeration type specific surface area measuring device.
1, 2;).

Other raw materials used with calcium carbonate include, but are not limited to, clay, satin white,
Titanium oxide, aluminum hydroxide, etc. can be used.

There are no particular restrictions on the ML coloring agent.
(Two threads are preferred, and if kept, oil-soluble phenols such as p-alkylphenol and p-allylphenol and aldehydes) Phenol resins such as 1g rank type condensates, aromas with hydroxyl groups r Polyvalent metal salts of organic carboxylic acids, such as zinc salts of derivatives of group carboxylic acids, e.g. salicylic acid? For example, the above-mentioned phenol resins are particularly preferred. Do these color developers have two or more effects on their own? Can be used in combination. The amount of color developer to be used is preferably μmo~35N after measuring 100N of pigment.
The amount of S et V is preferably 15 to 25 parts by weight.

It is also possible to use the above-mentioned M-type color developer together with 8-type color developers such as acid clay and activated clay, which have a color-developing effect.
It's the eyes.

As the post-school agent, natural rubber latex, styrene
Butadiene copolymer latex, butadiene copolymerized with acrylic acid or acrylic acid ester, or butadiene-styrene copolymer latex, acrylic rubber latex, vinyl acetate polymer copolymer with vinyl acetate and other monomers, etc. Synthetic rubber latex such as polymer latex, water bathable polymers such as polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, and oxidized starch? These can be used alone or in combination of two or more types of tMi.

The adhesive is determined by the adhesive strength of the film layer formed by the composition for pressure-sensitive copying paper, the adhesive strength of the film layer and the base paper, and the adhesive strength of the temporary composition. Is there a big impact on etc.? Since it gives, the quickest choice of seven is Wataan.

From this perspective, the following conditions (
A) ~(/1) It is particularly desirable to form an adhesive into a purple copolymer latex.

(a) The copolymer latex consists of the following monomer components ■Aliphatic conjugated diene 30-60% by weight■Ethylenically unsaturated phase carboxylic acid 2-15% by weight■Ethylenically unsaturated compounds other than @30~ It must be obtained by copolymerizing 60j@% by weight.

(b) Both N'clr latex latex ~ diameter is 0.0
Must be 4 to 0.09 μm. Here, what is the average tear diameter of the copolymer latex after it is treated with total osmic acid? A photograph was taken at a magnification of 30,000 times using an electron microscope, and the F particle 5 was found in the obtained microscopic photograph.
What is the average value of the numbers obtained by adding 11 of the 00 grain sizes? say.

←Toludiene content of copolymer 1 is 70 to 909 f5
)°%. What is the amount of toluene in 3 here?
Copolymer latex gold pH 6 by sodium hydroxide
After adjusting to ~8, it was coagulated with methanol, further washed and dried to collect 0.3p of the coagulated product (-). It refers to the ratio of insoluble matter to the whole sample.

This copolymer latex k M 9ti was used as a 9ti agent. It's soaked in spots.

The adhesive is preferably used in an amount of 3 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of the pigment.

〔Example〕

An embodiment of the present invention will be described below, but the invention is not limited to this.
%'' ζ, the staff member H workman hat 1 and the like are shown in purple.

Example 1-11. Specific examples 1 to 2 (IJ) Synthesis of copolymer latex In an autoknope directly rehydrated with nitrogen gas, butadiene
10 parts, 46 parts of styrene, 10 parts of methyl methacrylate, 3 parts of methacrylic acid, 1 part of itaconic acid, 1 part of ammonium persulfate, 3 parts of sodium dodecylbenzenesulfonate, 2.5 fJj+ of carbon tetrachloride; 250 parts of deionized water ? The mixture was charged and reacted at 70°C for 15 hours. The polymerization conversion rate at this time was 99% or more. The resulting copolymer latex was adjusted to pH 6.5 using sodium hydroxide, and then all of the steam was blown in to remove the remaining sodium hydroxide. Removed. Copolymer latex obtained in this way? Let's call it "Latex A".

Furthermore, the amount of sodium dodecylbenzenesulfonate + 77 μm added? Four types of latex were made in the same manner as above except for the changes. Also, the amount of carbon tetrachloride added? Two latex stocks were made in the same manner as above except for the changes. Obtained. A total of 6 pieces of latex gold "Latex BJ~"
"Latex G".

When the average particle size and toluene insoluble content of the polymer particles of Latex A to Latex GICj6 were determined, the results shown in Table 1 were obtained.

Table 1 (2) Manufacture of a temporary coating Pigment with the composition shown in Chapter 2, a color developer, an ammonium base, and a dispersant are used to disperse the pigment, an adhesive is added and mixed, and the solid content concentration is determined. A 50% pot temporary composition tJJ bag was used.

Here, the adhesive has the following composition.

Any one of latex A to latex G 7 parts oxidized starch 10 parts polyvinyl alcohol
: 3 parts Also, the average particle size of the RU calcium used as the pigment was 0.5 μm or less in all, except for Comparative Example 2, in which S gel was 71 μm. 3. As a dispersant, 0.2% of the polyacrylic sodium 'kA material was used.

(3) Characteristic Test The four types of coating compositions shown in Table 2, xtfi for Examples and Comparative Examples, were coated on high-quality paper (5317m2
) was coated on one side with a rod, dried, and then given a super calender finish, reducing the amount of machining to 517 m.
E-copying paper (color developer paper) was obtained.The following characteristic tests were conducted on each of these color developer papers.The results are also shown in Table 2.

(1) Whiteness Determined using a Hunter colorimeter and expressed as the reflectance of reflective light. For measurements, use a blue filter.

(2) Color development rate Using crystalline iolet lactone as the main pressure-sensitive dye, superimpose a commercially available top paper and the above-mentioned color developer paper so that their coated surfaces face each other. The copy paper is colored using an electric typewriter, and
The degree of color development was examined at 0 seconds, 45 seconds, 60 seconds, and 9 seconds after one day had elapsed, and the color development rate fc was calculated by the following method. That is, the whiteness before and after color development on color developer paper is determined by a Hunter colorimeter using a Hunter colorimeter, and the whiteness before one color development is Io (%), and the whiteness after one color development is It (%).

The color development rate Dt is determined by the following formula.

Io-It D t"I.

(8) Printing suitability Using a printing tester 1, the occurrence of dry vic and wet vic was visually observed, and the dry strength and wet strength were determined.

The rating is ◎ for extremely good items and 0 for somewhat good items.
Slightly poor samples were indicated by Δ, and poor samples were indicated by ×.

From the above results, in the 9 Examples of the present invention, good quality Tsumugi pots were obtained in all custom-made products. It was also confirmed that by adding ammonium salt, ``C'', color development (particularly color development speed reading), and color development magnetism were increased. On the other hand, in the comparative example, good results could not be obtained in all characteristics. In Comparative Example 1, since it did not contain an ammonium salt, the color development speed and rate were low and it was inferior in terms of 0 color development.

In Comparative Example 2, the particle size of the calcium charcoal used as the pigment was too large, and the properties were generally inferior at 9. In Comparative Example 8 and Comparative Example 4, the content ratio of returned calcium was too low.

It was found that all of them were inferior in all nine characteristics.

〔Effect of the invention〕

As is clear from the examples, the uninvented coating composition for pressure-sensitive copying paper has excellent color development properties and color tone stability of copied images, as well as excellent water resistance and printability. Moreover, it has good coating properties and is extremely useful in practice.

In particular, by using ammonium salt as a composition component, it has become possible to achieve remarkable color development. The usefulness of coating compositions using MA coloring agents can be increased.

Agent Patent Attorney Masahiko Inui 3.2 No. 1 Procedural Amendment (Voluntary) October 20, 1980 Commissioner of the Patent Office Manabu Shiga 1. Indication of the case 1.4-:,,2? (!Showa 59
Patent application 2 filed on September 29, 2013, title of invention: Coating composition for pressure-sensitive copying paper 3, relationship with the amended case Patent applicant address: 2-11-24 Tsukiji, Chuo-ku, Tokyo (427) Japan Synthetic Rubber Co., Ltd. 4, Agent 5, Subject of amendment (1) Detailed description of the invention in the specification column 6, Contents of amendment (1) Page 16 of the specification, Table 2 (the The adhesive (Latte Nox) section in the coating composition column in 2) was changed to Comparative Example 1.
-4 will be supplemented as follows.

Claims (1)

[Scope of Claims] 1) A coating composition for pressure-sensitive copying paper whose main components are a pigment containing 30% by weight or more of finely particulate calcium carbonate with an average particle size of 0.5 μm or less, a color developer, and an adhesive. A coating composition for pressure-sensitive copying paper, characterized in that it contains at least one ammonium salt in an amount of 0.1 to 7.0 parts by weight based on 100 parts by weight of the pigment. 2) The coating composition for pressure-sensitive copying paper according to claim 1, wherein the color developer is an organic color developer. 3) A pigment containing 30% by weight or more of finely particulate calcium carbonate with an average particle diameter of 0.5 μm or less, a color developer, an adhesive, and an amount corresponding to 0.1 to 7.0 parts by weight per 100 parts by weight of the pigment. The adhesive contains at least one ammonium salt, and the adhesive contains the following monomer components: (a) aliphatic conjugated diene, 30 to 60% by weight, and (b) ethylenically unsaturated carboxylic acid, 2 to 15% by weight. (c) (b)
A copolymer latex obtained by copolymerizing 30 to 60% by weight of an ethylenically unsaturated compound other than the above, the average particle size of which is 0.04 to 0.09 μm, and the toluene insoluble content of the copolymer is 70% by weight. 90% by weight of a coating composition for pressure-sensitive copying paper.