JPS6246679A - Thermal recording material - Google Patents

Abstract

PURPOSE:To provide a coated film having high water resistance at low temperatures and excellent operability (little contamination of a thermal head and a high sticking resistance), by using a color forming substance, a color developer for developing the color of the color forming substance when being heated, a polyvinyl alcohol resin and a water-soluble reactive resin comprising a specified comonomer as an essential constituent. CONSTITUTION:A water-soluble reactive resin comprising as an essential constituent a comonomer of general formula (I), wherein l is a positive integer, m is 0 or a positive integer, n is 2 or 3, and A is -O- or -NH-, is used as a water- resisting agent for a binder. The thermal recording material is produced by the usual coating method. The color former, the color developer and the binder are suitably used in respective amounts of 5-20%, 10-60% and 20-70% based on the weight of the color forming layer. The amount of the reactive resin is suitably 5-60wt% based on the amount of the PVA resin. The coating material is applied to the surface of a base by a known coating system, and the coating amount is ordinarily 2-10g/m<2> on a dry basis.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a heat-sensitive recording material that forms a highly water-resistant film at low temperatures, has excellent workability, and exhibits a cooling effect.

[Technical background of the invention and its problems]

Thermosensitive recording paper is a recording paper obtained by coating one side of base paper with a layer that develops color when heated. It has grown particularly rapidly among paper for the information industry, and has recently become popular as a printer paper for high-speed facsimiles and POS systems.

A water-bathable binder is used as a binder for a color-forming substance and a color developer. Conventional polyvinyl alcohol (hereinafter abbreviated as PVA), methylcellulose, hydroxycellulose, modified starch.

Carboxymethyl cellulose, petroleum resin, epoxy resin, maleic acid resin, f! Although lyacrylamide and the like are used, PVA is currently most commonly used. However, PVA alone lacks water resistance. Therefore, water-resistant agents such as formaldehyde, glyoxal, noaldehyde starch, urea resin, or melamine resin are usually required, but even if all of these water-resistant agents are used, it is difficult to achieve a well-balanced and high level of various qualities. . That is, it is difficult to obtain a water-resistant agent that is excellent in all of adhesion, water resistance, and workability (sticking and residue adhesion).

In addition, when coating and drying with a water-resistant agent such as a dialdehyde compound, if you try to dry at a safe temperature (approximately 60 degrees Celsius or less) that does not cause color development, it may be difficult for water resistance to progress sufficiently. .

[Effects of the present invention]

As a result of extensive research into binders that form a complete film that is highly water resistant at low temperatures and has excellent workability (less thermal head stains and high staining resistance), the inventors have discovered that a specific reactive water-soluble It was discovered that a combination of polyester resin '1 with a PVA-based resin is suitable for the purpose, and based on this knowledge, the present invention was completed.

[Means to solve all problems]

The present invention will be explained in detail below.

That is, the present invention comprises a color-forming substance, a color developer that causes the color-forming substance to develop color by heating, a PVA resin as a binder, and a reactive water-bathable resin containing a comonomer represented by the following general formula (R) as an essential component. The present invention provides a complete thermal recording material consisting of:

In the formula R 1 or -OH.

R: -CI (first order is -Cf (2CH.

R: CH or -CH2CH3 (X is a halogen element) R5: -H or 10ft3 t: Positive integer m: 0 or positive integer n: 2 and 3 A: -0- or -NH one As the color-forming material in the invention, a color-forming lactone compound is exemplified. The color-forming lactone compound may be one that can develop color by reacting with an acidic compound when heated, and is not particularly limited, such as triphenylmethane, triphenylmethane phthalide thread, fluoran, and leucoauramine , spiropyran series 4t
Examples include various leuco compounds. In addition, as a color developer, it is a substance that liquefies or vaporizes when heated by the thermal head, reacts with the color-forming substance, and causes it to develop color. Laoxybenzoic acid bennor ester, bisphenol A, 2,2'-nohydroxydiphenyl, 2
．． 2'-methylenebis(4-methyl-6-tart-butylphenol), 4,4'-isoglopylidenebis(
2-chlorophenol), 4,4'-5ec-butylidene diphenol, β-naphthol.

Examples include, but are not limited to, 4.4'-cyclohexylidene bis(2-methylphenol), novolak type phenol resin, and halonated nodelac type phenol resin.

The PVA resin used in the present invention is used as a constituent component of the binder. Typical examples include partially saponified or completely saponified polyvinyl acetate, vinyl esters and monomers copolymerizable with them, such as ethylene, propylene, isobutylene, α-octene, α-dodecene, α-octodecene, etc. olefins, unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, and itaconic acid, or their salts, monotolyles such as mono- or noalkyl esters, amides such as acrylamide and methacrylamide. Examples include saponified copolymers with olefin sulfonic acids or their salts such as ethylene sulfonic acid, allyl sulfonic acid, meta-allylsulfonic acid, alkyl vinyl ethers, vinyl ketones, N-vinyl pyrrolidone, vinyl chloride, [hynylidene chloride, etc.] However, it is not necessarily limited to these.

The reactive water-based resin (1) of the present invention is used as a water-resistant agent for a binder, but in order to obtain it, dialkylaminoalkyl (meth)acrylate tri is first mixed with dialkylaminoalkyl (meth)acrylamide hydrochloride and chlorohydroxy It is obtained by total copolymerization with (meth)acrylate, and then reacting the side chain tertiary amine groups of this copolymer with shrimp halohydrin. Also, these 2
In addition to these components, monomers that can be copolymerized with these components may also be used. For example, (meth)acrylic acid.

Unsaturated acids such as maleic acid, fumaric acid, itaconic acid or their salts, or mono- or noalkoxy esters,
Nido IJ such as (meth)acrylonitrile/amides such as l'al (meth)acrylamide, ethylene sulfone I
'ffl, olefin sulfonic acids or salts thereof such as (meth)allylsulfonic acid, alkyl vinyl ethers,
Examples include, but are not limited to, vinyl ketone and N-vinylpyrrolidone.

The polymerization reaction uses a normal radical polymerization catalyst and water m
Perform in liquid. The reaction between the copolymer and shrimp halohydrin is carried out by adding shrimp halohydrin gold to the copolymer and heating the mixture. Here, the dialkylaminoalkyl (meth)acrylate refers to, for example, trimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and noethylaminoglopyl (meth)acrylate gold. , and the dialkylaminoalkyl (meth)acrylamide refers to, for example, dimethylaminoethyl (meth)acrylamide, dimethylaminopropyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and noethylaminoglobil (meth)acrylamide.

Further, the above-mentioned epino-rohydrin refers to, for example, epichlorohydrin and ebibromohydrin. In addition, the reactive water-soluble resin is PI''! Totally hydroxylated) I
It exhibits the best effect when used as a water-resistant agent after adjusting the total amount of Jum to 7 or more.

The drying temperature after coating the heat-sensitive recording material of the present invention on the supporting substrate is suitably a low temperature (60°C or less) at which no color development occurs due to the phase M1 reaction between the color former and the acidic compound, that is, 40°C to 60°C. .

The heat-sensitive recording material of the present invention is manufactured by a conventional coating method. In this case, the amounts of the color forming agent, color developer, and binder used are 5 to 20, and 10 to 60, respectively, per color forming layer.
A range of 20 to 70% is suitable. Further, the ratio of the reactive water bathing resin to the PVA resin is suitably 5 to 60 parts. When making a paint, other additives such as dispersants, fillers, white pigments, wax,
dye.

One coloring agent and a surfactant may be added to the pigment, or an fc diluent may be added to improve coating suitability. After performing the obstetric coating as described above, the plate surface of the support is coated using a known coating method such as roll coating or gravure coating, usually in a coating amount (dry basis) of 2 to 10.
9/m”.

Further, although the present invention consists of the basic configuration as described above, iam
i may be provided. Furthermore, as a binder, binders other than PVA resin such as methyl cellulose, polyacrylamide, Cal? oxymethylcellulose, Denji/
Latex, etc.? It is also possible to use a mixture. However, even in that case, the PVA that accounts for the entire Bayhgu
The weight of the system resin must be 50wt or more.

Next, the present invention will be explained in more detail with reference to all embodiments.

Unless otherwise specified, "%" and "part" refer to heavy machinery standards.

Reference Examples 1 to 4> Reference Example 1 Completely equipped with nitrogen gas blowing device, thermometer, and I) H electrode; i
500ff+7! 47.2 g (0.3 mol) of dimethylaminoethyl methacrylate and 16.5 g (0.1 mol) of 1! was collected and an additional 94.41 t of water was added. Next, 30.4.9' of 36-thihydrochloric acid was added to this, and while stirring at 60°C under a nitrogen atmosphere, 110% of potassium persulfate was added.
Polymerize for 3 hours using , IN (1 mol % of heptamer) as a catalyst. In order to prevent the Weisenberg phenomenon and the glue effect,
Furthermore, 62.79 g of water is appropriately added to obtain a copolymer bath liquid with a nonvolatile content of 30 g.

Next, this copolymer was diluted with water to 33.7I
of epichlorohydrin is added, and the reaction is carried out by heating at 65° C. in the range of 142 to 6 for 2 and a half hours to obtain reactive water-based tree fat.

5% water bath solution 2 of the reactive water bath resin synthesized in this way
77I to 20% sodium hydroxide water bath solution 28.219'
(Add 1 and leave at room temperature for 10 minutes.

Reference Example 2 Into the same apparatus as Reference Example 1, 39.3 g (0.25 mol) of trimethylaminoethyl methacrylamide and 2f'+, 8/(0.15 mol) of chlorohydroquine methacrylate were added.
Collect the water and add 98.3.9 fd: to the kudzu. Next, 25.39' of 36-dihydrochloric acid is added to this.

Polymerization was carried out in the same manner as in Reference Example 1, and then 63.5 ft of water was added to obtain a copolymer bath liquid containing 30 t of non-volatile matter.

Hereinafter, as in Reference Example 1, epichlorohydrin 28.19
to obtain a reactive water-core resin.

5% water bath solution 2 of reactive water bath resin synthesized as above
(20% hydroxide to 64I) IJum hydroelectric liquid 13.8J
Add i' and leave at room temperature for 10 minutes.

Reference Example 3 Into the same apparatus as in Reference Example 1, all 47.2II (dimethylaminoethyl methacrylate) (0.3 mol) was collected, and water 26
7. Add li. Next, add 29.0J of 35% hydrochloric acid to this.
ammonium persulfate 1.64.9 (1 mol S of monomers) with stirring at 60°C under nitrogen atmosphere.
was used as a catalyst for polymerization for 3 hours.

115.0.9% of water was added to the obtained polymer 115.0.9%. ! i'
is added to obtain a polymer water core grade with a nonvolatile content of 8.5%. 3
-J, epichlorohydrin 11.1 as in Reference Example 1 below
yt reaction to obtain a one-reactive water-core resin.

5. Water bath solution 1 of reactive water core resin synthesized as above.
26.5.9 20% hydroxide) IJum water pericardial fluid 6,
Add 0&k and leave at room temperature for 10 minutes.

Reference Example 4 In the same apparatus as in Reference Example 1, 39. Og (0.25 mol), chlorohydroxyacrylate) 1fi, 5# (0.1 mol) and 5
0 thiacrylamide 7, I J (0.05 mol) is taken and a further 82.6.9 i of water is added. Next, 24.1.9% of 36-thihydrochloric acid was added, and while stirring at 60°C under nitrogen atmosphere, 1.11% of potassium persulfate (1.11% of monomer) was added.
mol %) as a catalyst for 3 hours, and then water 59.
0.9 to obtain a copolymer aqueous solution with a nonvolatile content of 30%.

This obtained copolymer water #1loo, (200 g of water per l
1 was added to make the nonvolatile content 10%, and then 12.4 g of epichlorohydrin was added to obtain a reactive water bath resin in the same manner as in Reference Example 1. To 200 g of the 5-chi water bath solution of the 9-reaction water injection resin synthesized as described above, 9.97 g of the 20% sodium hydroxide water bath solution was added and left at room temperature for 10 minutes.

<Examples 1 to 4> Example I Liquid A: Crystal violet lactone 20 parts by weight PV'A (degree of saponification 99 molar, average degree of polymerization 1750) 10 parts water 25 parts water
55 parts B liquid: Bisphenol A 20 heavy claws PVA (saponification degree 9
9 mol, average degree of polymerization 1750) 10 ml water 25 parts water
55 parts Solution C: N-stearylphenylamide 20 parts PVA (saponification degree 99 molti, average polymerization degree 1750) 10% water bath solution 25 parts water
55 parts Liquid: Reactive water-based resin synthesized in Reference Example 1 The above liquids A, B, and C were separately pulverized and dispersed in a sol mill for 24 hours, and then mixed in the following proportions to form a thermosensitive coloring layer forming liquid. Adjust it.

Liquid A 1.0 Jushabu B Kin 4. OIC liquid 2. OM total liquid 1.4# Apply this heat-sensitive coloring layer forming liquid to high-quality paper (1 tsubo 1i50#/FFI
”), the adhesion resistance when drying at 40°C is 69/
The entire heat-sensitive recording material of the present invention was prepared by coating the heat-sensitive recording material to form a heat-sensitive coloring layer.

Next, this heat-sensitive recording material was transferred to a commercially available facsimile IJ (manufactured by Matsushita Electric Co., Ltd., ANAFAX UF-1100).
02FI printing was performed, and the degree of contamination of the head and occurrence of sticking were observed. Regarding water resistance, the resulting heat-sensitive recording material was immersed in all water for 20 minutes, taken out, and then rubbed back and forth with fingertips 20 times to observe the surface condition. Table 1 shows the results of the 3° evaluation, in which good physical properties are indicated by ○, poor properties are indicated by ×7, and intermediate stages are indicated by Δ.

Example 2 The procedure was the same as in Example 1, except that the D solution was changed from the reactive water injection M resin synthesized in Reference Example 1 to the reactive water omega resin synthesized in Reference Example 2. A heat-sensitive recording material was prepared.

The evaluation results are shown in Table 1.

Example 3 Thermal recording was carried out in the same manner as in Example 1, except that the reactive water-soluble resin synthesized in Reference Example 1 was changed to the reactive water-soluble resin synthesized in Reference Example 3 as Liquid D. Created the material. The evaluation results are shown in Table 1.

Example 4 Thermosensitive recording was carried out in the same manner as in Example 1, except that in Example 1, the reactive water-soluble resin synthesized in Reference Example 1 was changed to the reactive water-bathable resin synthesized in Reference Example 4. 9.Create the materials.

The evaluation results are shown in Table 1.

Comparative Examples 1 to 3> Comparative Example 1 A heat-sensitive recording material was prepared in the same manner as in Example 1 except that the liquid D was removed and the drying temperature was 50°C. The evaluation results are shown in Table WJ1.

Comparative Example 2 A heat-sensitive recording material was prepared in the same manner as in Comparative Example 1, except that a PVA 10 fy water/liquid solution containing 5% glyoxol gold, a water resistance agent, was added to PVA.

The evaluation results are shown in Table 1.

Comparative Example 3 In Example 1, the ratio of Solution D in the thermosensitive color forming layer forming solution was set to 0.5 parts. Otherwise, a heat-sensitive recording material was prepared in the same manner as in Example 1+jjl. Show the evaluation results in the first disaster fCc Table 1

Claims (1)

[Claims] (1) Consisting of a color-forming substance, a color developer that causes the color-forming substance to develop color by heating, a polyvinyl alcohol resin, and a reactive water-soluble resin whose essential component is a comonomer represented by the following general formula (I). A heat-sensitive recording material characterized by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) In the formula R_1; -H or -CH_3 R_2; -CH_3 or -CH_2CH_3 R_3; -CH_3 or -CH_2CH_3 R_4; ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (X is a halogen element) R5; -H or -CH_3 l: Positive integer m; 0 or positive integer n; 2 or 3 A; -O- or -NH −