JPS6367181A - Thermal recording material - Google Patents

Abstract

PURPOSE:To prevent jamming in a thermal printer, by incorporating a specific compound in a thermal layer containing colorless or faint color dye precursor material or a compound reactable therewith to exhibit color or in a thermal layer containing a diazo compound or a compound reactable therewith to exhibit color. CONSTITUTION:In a supporting material such as paper or plastic and a thermal layer being provided thereon, triaryl methane compound, diphenyl methane compound, xanthin compound, thiazine compound, spiropyrene compound, diazo compound, etc. are employed as a colorless or faint color dye precursor material which is a main component of the thermal layer. One or more than one kind of said compounds are employed, and a compound shown by formula I is employed by 0.0001-0.5g, preferably 0.05-0.2g, per 1m<2> of supporting material in the thermal layer composed of said compounds.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a heat-sensitive recording material. The present invention relates to a heat-sensitive recording material that utilizes a color reaction between a chromatic compound (referred to as a color compound) or a color reaction between a diazo compound and a component that reacts with the diazo compound to form a color.

[Prior art]

As conventional heat-sensitive recording materials, so-called two-component heat-sensitive recording materials that utilize a color reaction between a colorless or light-colored electron-donating dye precursor and an electron-accepting compound are disclosed in Japanese Patent Publications No. 45-14039, Japanese Patent Publication No. 43-4160, Japanese Unexamined Patent Publication No. 59-19 [188
As described in publications such as No. 6, these two-component heat-sensitive recording materials are primary color-forming, do not require development processing, are easy to handle, have high color density, and are available in various color hues. It has the advantage of being easy to manufacture and has great utility value, so it is the most widely used of the various heat-sensitive recording materials. Particularly in recent years, its use has expanded not only to the facsimile, recorder, and printer fields, but also to the label field such as POS.

[Problem that the invention seeks to solve]

However, in recent years, in order to reduce the weight of thermal printing apparatuses, the material of the recording sheet conveying system members of thermal printing apparatuses has been replaced by plastic instead of the conventional metal.

Therefore, conventional heat-sensitive recording sheets become electrically charged when they come into contact with conveyance systems such as stockers, rollers, and trays, and the sheets stick to each other or the sheets and the conveyance system due to electrostatic force.
There was a problem in that so-called "jamming" was likely to occur.

[Means and effects for solving the problems] The present invention aims to solve the problems in the prior art described above, and to provide a new heat-sensitive recording material having even more excellent characteristics. The structure consists of a heat-sensitive layer containing a colorless to light-colored dye precursor and a compound that develops color by reacting with the dye precursor, or a diazo compound and a compound that reacts with the diazo compound on a support such as paper or silastic. The present invention is a heat-sensitive recording material provided with a heat-sensitive layer containing a component that develops color when the heat-sensitive recording material is heated, and is characterized in that it contains a compound represented by the following general formula (I).

General formula (I) (wherein, R1 to R+ are an alkyl group having 1 to 2 carbon atoms or an aryl group having 6 to 30 carbon atoms (they may form a ring with each other), and M is a halogen atom. ) The present invention will be described in detail below.

As mentioned above, the most characteristic feature of the present invention is that any layer of the heat-sensitive recording material contains the general formula (I) (wherein R1 to R4 are alkyl groups having 1 to 20 carbon atoms or 6 carbon atoms). -3o aryl groups (which may form a ring with each other) are contained in a compound represented by (M represents a halogen atom).

Specific examples of the compound represented by the general formula (I) include the following.

At least one of these compounds represented by general formula (I) is used.

These compounds usually contain 0.0[
] [Used in an amount of about 111 to 0.5 g, preferably about 0.05 to 0.2 g.

The heat-sensitive recording material of the present invention basically consists of a support such as paper or plastic, and a heat-sensitive layer provided thereon.

Examples of colorless to light-colored dye precursors that are the main components of the heat-sensitive layer include triarylmethane compounds, diphenylmethane compounds, xanthine compounds, thiazine compounds,
These include spiropyran compounds, diazo compounds, etc. To give specific examples, examples of triarylmethane compounds include 3,6-bis(p-Jmethylaminophenyl)-, 6-+dimethylaminophthari)'' (common name:
crystal violet lactone), 3,3-bis(p
-J methylaminophenyl)-phthalide, 3-(p--
Dimethylaminophenyl) i-(I,3-dimethylindol-6-yl) phthalide, 3-(p-dimethylaminophenyl)-3-(2-methylindol-3-yl) phthalide, etc., and diphenylmethane compounds. Examples include 4,4-bis-dimethylaminobenzhydrin pendyl ether, N-halophenylchloramine,
N-2,4,5-)lichlorophenylleucoauramine, etc., and xanthine compounds include rhodamine-B-anilinolactam and rhodamine (p-nitrino).
Lactam, 2-(dibenzylamino)fluorane, 2-
Phenylamino-6-diethylaminofluorane, 2-
(o-chloroanilino)-6-dinitylaminofluorane, 2-(3゜4-dichloroanilino)-6-dinitylaminofluorane, 2-anilino-3-methyl-6-piperidinofluorane, 2- Examples include phenyl-6-dinithylaminofluorane, and spiro-based compounds include 3-
Methylspiro-dinaphthopyran, 3-ethylspiro-dinaphthopyran, 3.3'-dichlorospiro-dinaphthopyran, 3-benzylspiro-naphthopyran, 3-methyl-naphtho-(3-methoxybenzo)-spiropyran, 3
-Propyl-spiro-dibenzopyran and the like.

These compounds may be used alone, or two or more of them may be used in combination.

The diazo compound used in the present invention has the general formula
ArN2+χ- (where Ar is a substituted or unsubstituted aromatic group, N
, 2+ represents a diazonium group, and X- represents an acid anion. ) It is a diazonium salt represented by: It is a compound that can develop a color by causing a coupling reaction with a coupling component, and can be decomposed by light.

Specific examples of diazonium compounds that form salts are 4.
-Diazo-1-dimethylaminobenzene, 4-diazo-
1-diethylaminobenzene, 4-diazo-1-dibropylaminobenzene, 4-diazo-1-methylbenzylaminobenzene, 4-diazo-1-diethylaminobenzene, 4-diazo-1-ethylhydroxyethylaminobenzene, 4 -Diazo-1-diethylamino-3-methoxybenzene, 4-diazo-1-dimethylamino-2-
Methylbenzene, 4-diazo-1-benzoylamino-
2,5-jethoxybenzene, 4-diazo-1-morpholinobenzene, 4-diazo-1-morpholino-2,5-
Jetoxybenzene, 4-diazo-1-morpholino-2
, 5-dibutoxybenzene, 4-diazo-1=anilinobenzene, 4-diazo-1-tolylmercapto-2,
Examples include 5-jethoxybenzene and 4-diazo-1,4-methoxybenzoylamino-2,5-jethoxybenzene.

Specific examples of acid anions include Cm F2m+ICO〇- (m represents an integer from 3 to 9)
, Cn F2n+ISO+a- (n represents an integer from 2 to 8), (CJ! F2ji!+j S 02 ) Z
CH (β is an integer of 1 to 18 C, 3H27CON H 15H31 H C5H5 BF, PF6, etc.).

As the color-developing heat-sensitive layer contained in the heat-sensitive layer of the present invention, compounds represented by the following general formulas (IV) to -VIII) are preferred.

(In the formula, X is s, o, SO2, S2, and R2 are each a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group formed by bonding R1 and Rλ, and R is carbon It represents a straight chain or branched alkyl group or a halogen atom having 1 to 8 atoms.) (In the formula, Y represents a hydrogen atom, a methyl group, or a hydroxyl group, and R represents -(-CHO)m-C6H5-Z.

1+CH2)n OC6R5Z1 A straight chain or branched alkyl group having 1 to 6 carbon atoms, and m and n are 0
an integer of ~3, and Z represents a hydrogen atom, a halogen atom, or a methyl group. (In the formula, R4 represents a benzyl group, a halogen atom, a benzyl group substituted with a straight chain or branched alkyl group having 1 to 8 carbon atoms, or a straight chain or branched alkyl group having 1 to 8 carbon atoms. ) (In the formula, R6 and R7 are Aru having 1 to 8 carbon atoms -- general formula m1I) (In the formula, R8 represents an alkylene group containing 1 to 5 ether bonds.

Preferred examples other than the electron-accepting compounds represented by the above general formulas (IV) to (VIII) include bis-hydroxycumylbenzenes or bis-hydroxy-α-
Methylbenzylbenzenes, specific examples are 1
．． 4-bis-hydroxycumylbenzene, 1.4-bis-m-hydroxycumylbenzene, 1.3-bis-p
-Hydroxycumylbenzene, 1,3-bis-m-hydroxycumylbenzene, 114-bis-m-hydroxycumylbenzene, 1,4-bis-p-hydroxy-α-
Examples include methylbenzylbenzene, and salicylic acid derivatives include 3,5-di-α-methylbenzylsalicylic acid, 3,5-di-butylsalicylic acid, 3-α,α
- Salicylic acids such as dimethylbenzyl salicylic acid, or polyvalent metal salts thereof, particularly zinc salts and aluminum salts, and others such as p-phenylphenol, 3,5-diphenylphenol, and cumylphenol.

The above color developing compound is preferably used in an amount of 50 to 1000% by weight, more preferably 100% by weight of the dye precursor.
~500% by weight.

These compounds may be used alone or in combination of two or more.

When the dye precursor is a diazo compound, the coupling component is one that forms a dye by coupling with the diazo compound (diazonium salt) in a basic atmosphere.Specific examples include resorcinol, phloroglucin, 2.
Sodium 3-dihydroxynaphthalene-6-sulfonate, 1-hydroxy-2-naphthoic acid morpholinopropylamide, 1,5-dihydroxynaphthalene, 2,3-
Dihydroxynaphthalene, 2,3-dihydroxy-6-
Sulfanylnaphthalene, 2-hydroxy-3-naphthoic acid morpholinopropylamide, 2-hydroxy-3-
Naphthoic acid anilide, 2-hydroxy-3-naphthoic acid-2°-methylanilide, 2-hydroxy-3-naphthoic acid ethanolamide, 2-hydroxy-3-naphthoic acid octylamide, 2-hydroxy-3-naphthoic acid-
N-dodecyloxypropylamide, 2-hydroxy-
3-Naphthoic acid tetradodecylamide, acetanilide, benzoylacetanilide, 1-phenyl-3-methyl-5-pyrazolone, 1-(2', 4', 6°-
trichlorophenyl)-3-benzamido-5-pyrazolone, 1-(2',4°,6'-)lichlorophenyl)
-3-anilino-5-pyrazolone, 1-phenyl-3-
Examples include phenylacetanilide-5-pyrazolone.

Furthermore, by using two or more of these force/knobbling components in combination, an image of any tone can be obtained.

As the color development aid of the present invention, a slightly water-soluble or water-insoluble basic substance or a substance that generates an alkali when heated is used.

Coloring aids include inorganic and organic ammonium salts, organic amines, amides, urea and thiourea and their derivatives, thiazoles, pyrroles, pyrimidines, piperazines, guanidines, indoles, imidazoles, imidacillins, triazoles. There are nitrogen-containing compounds such as morpholines, piperidines, amidines, formazines, and pyridines.

In the heat-sensitive recording material according to the present invention, a heat-fusible substance can be contained in the heat-sensitive layer in order to improve its thermal responsiveness.

Specifically, benzyl p-benzyloxybenzoate, β
-Naphthylbenzyl ether, niaric acid amide, palmitic acid amide, N-phenyl niaric acid amide, N-
Stearylurea, β-naphthoic acid phenyl ester, 1
-Hydroxy-2-naphthoic acid phenyl ester, β-
Naphthol (p-chlorobenzyl) ether, β-naphthol (p-methylbenzyl) ether, α-naphthylbenzyl ether, 114-butanediol-p-methylphenyl ether, 1,4-propanediol-p-
Methyl phenyl ether, 1,4-butanediol-p
-isopropylphenyl ether, 1,4-butanediol-p-t-octylphenyl ether, 2-phenoxy-1-p-)lyloxyethane, 1-phenoxy-
Examples include 2-(4-ethylphenoxy)ethane, 1-phenoxy-2-(4-chlorophenoxy)ethane, and 1,4-butanediol phenyl ether.

The thermofusible substance may be used alone or in combination of two or more, and in order to obtain sufficient thermal responsiveness, it is preferably used in an amount of 10 to 200% by weight based on the electron-accepting compound. More preferably, it is used in an amount of 20 to 150% by weight.

In two-component heat-sensitive recording materials that use an electron-donating dye precursor and an electron-accepting compound, the recorded images generally tend to fade due to the influence of external conditions such as humidity and heat.

In the heat-sensitive recording material according to the present invention, it is preferable to include a compound that prevents discoloration in the heat-sensitive layer in order to prevent such discoloration and to make the generated image more robust.

Phenol derivatives, especially hindered phenol compounds, are effective as anti-fading agents.

The amount of the phenol compound to be used is preferably 1 to 200% by weight, more preferably 5 to 50% by weight based on the electron accepting compound.

Polymers used as adhesives for the heat-sensitive layer of the present invention include polyvinyl alcohol, carboxy-modified polyvinyl alcohol, silica-modified polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride. Water-soluble copolymer hydrolysates, styrene-maleic anhydride copolymer Hafestel hydrolysates, isobutylene-maleic anhydride a co-m hydrolysates, polyacrylamide derivatives, polyvinylpyrrolidone, sodium polystyrene sulfonate, sodium alginate, etc. Polymers and water-insoluble polymers such as styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and polyvinyl acetate emulsion can be used in combination.

Pigments, metal soaps, waxes, surfactants, crosslinking agents, etc. may be added to the heat-sensitive layer of the heat-sensitive recording material of the present invention, if necessary.

Pigments include zinc oxide, calcium carbonate, barium sulfate,
Examples include titanium oxide, lithopone, talc, Rouseki, kaolin, aluminum hydroxide, silica, amorphous silica, etc. Metal soaps include emulsions of higher fatty acid metal salts such as zinc stearate, calcium stearate, and aluminum stearate. Waxes include emulsions such as paraffin wax, microcrystalline wax, carnauba wax, methylolstearamide, and polyethylene wax; surfactants include sulfosuccinic acid-based alkali metal salt fluorine-containing surfactants; must be selected appropriately depending on the type of polymer, but polyamines such as polyethyleneimine, dialdehydes such as glutaraldehyde,
Examples include polymethylol compounds such as methylol melamine, epoxy compounds, jurnium salts, and other inorganic salts. In the present invention, in particular, glutaraldehyde, glyoxal dimethoxyurea, 2,3-dihydroxy-1
, 4-dioxane and the like are preferred.

The amount of these additives added is 0.1 to 15% by weight, preferably 1 to 10% by weight, based on the polymer of the heat-sensitive layer.

Further, the dry coating amount of the heat-sensitive layer is preferably within the range of 1 to Log/r+7.

A protective layer may be provided on the heat-sensitive layer of the heat-sensitive recording material of the present invention, if desired. The main components of the M retention layer are (1) film-forming polymers.

Polymers used in the iJ5 include methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, and styrene-maleic anhydride copolymer Herfestel hydrate. Water-soluble polymers such as decomposition products, isobutylene-maleic anhydride non-polymer hydrolysates, polyvinyl alcohol, silica-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, polyacrylamide derivatives, polyvinylpyrrolidone, sodium polystyrene sulfonate, sodium alginate, and styrene. There are water-insoluble polymers such as acrylonitrile-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and polyvinyl acetate emulsion, and these polymers can be used alone or in combination of two or more. You can also do that.

Pigments, metal soaps, wax, crosslinking agents, etc. are added to the above-mentioned protective layer for the purpose of improving thermal and gutter matching during printing and improving the water resistance of the protective layer.

Pigments include zinc oxide, calcium carbonate, barium sulfate,
Titanium oxide, lithopone, talc, Rouseki, kaolin, aluminum hydroxide, silica, amorphous silica, etc. are added in an amount of 0.5 to 4 times the total weight of the polymer, preferably 0.8 to 3 times the total weight of the polymer. .5 times the amount. If the amount is below the lower limit of the above range, it will be ineffective in improving the head matching properties, and if the amount is above the upper limit, the sensitivity of the heat-sensitive recording material will drop significantly, impairing its commercial value.

Metal soaps include emulsions of higher fatty acid metal salts such as zinc stearate, calcium stearate, and aluminum stearate, and contain 0.5 to 0.5 of the total weight of the protective layer.
It is added in an amount of 20% by weight, preferably 1-10% by weight. Waxes include emulsions such as paraffin wax, microcrystalline wax, carnauba wax, methylolstearamide, and polyethylene wax, which are added in an amount of 1 to 20% by weight, preferably 1 to 10% by weight of the total weight of the protective layer. be done.

Further, when forming a protective layer on the heat-sensitive layer, a surfactant is added to the coating solution for forming the protective layer in order to form a uniform coating layer. Surfactants include sulfosuccinic acid-based alkali metal salts, fluorine-containing surfactants, and more specifically, cy(2-ethylhexyl)sulfosuccinic acid, di(
Examples include sodium salts or ammonium salts such as n-hexyl)sulfosuccinic acid, but generally any anionic surfactant is effective.

The dry coating amount of the protective layer is preferably about 0.5 to Log/ffl, particularly preferably about 1 to 5 g/m.

[Examples] - The present invention will be explained in more detail and specifically based on Examples. In addition, "%" in each example is "weight%"
", 7 parts" is "parts by weight".

Example 1 20 g each of crystal violet lactone, benzyl parahydroxybenzoate, stearamide, and 1゜1.3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane were added to 5% polyvinyl alcohol (
Manufactured by Kuraray, product name: PVA 105) Aqueous solution 10
A dispersion treatment was carried out with a ball mill for one day and a night with 0 g to prepare a dispersion liquid in which the volume average particle diameter of each solid component was 3 μm or less.

On the other hand, 108 g of pigment was dispersed with 160 g of 0.5% sodium hexametaphosphate solution using a homogenizer to prepare a pigment dispersion.

Each dispersion prepared as described above, 5 g of crystal violet lactone dispersion, 10 g of benzyl hydroxybenzoate dispersion, 5 g of stearamide dispersion, LL
3-) 2 g of lis(2-methyl-4-humanwaxy-5-tert-butylphenyl)butane dispersion.

Mix 5 g of the pigment dispersion, and further add 3 g of 21% zinc stearate emulsion, 4% 2,3-dihydroxy-5-methyl-1,4-dioxane log, and 2 parts di(2-ethylhexyl)-sulfonate. The coating solution obtained by adding 5 g of sodium succinate aqueous solution has a basis weight of 60 g/r.
+? Dry coating amount 5g/rr with a wire bar on high quality paper
? It was coated to give a heat-sensitive layer and dried in an oven at a temperature of 50°C.

Furthermore, a coating solution having the following composition was applied onto the obtained heat-sensitive layer using a wire bar so as to have a dry weight of 3 g/m, and was dried in an oven at a temperature of 50°C to form a protective layer.

Furthermore, a mixed solution having the following composition was applied to the back side of the support using a wire bar so that the dry weight was 3 g/m, and the mixture was dried in an oven at a temperature of 50°C to form a bank layer.

As described above, heat-sensitive recording material sample No. 1 was obtained.

Example 2 The coating liquid composition of the back layer in Example 1 was as follows, and the coating dry weight was 0.2 g/m, and the other conditions were as follows.Example 1
A heat-sensitive recording material sample No. 2 was prepared in the same manner as in the case of .

(In the main text) Compound ■ Solid content ---------- 1 part Example 3 The composition of the coating liquid for the back layer in Example 1 was as follows, the dry weight of the coating was 0.2 g/m, etc. Example 1
A heat-sensitive recording material sample No. 3 was prepared in the same manner as in the case of .

(In the text) Compound ■ Solid content ------- 1 part Example 4 The composition of the coating solution for the protective layer in Example 1 was as follows, and the coating dry weight was 0.01 g/m, and A heat-sensitive recording material No. 4 was prepared in the same manner as in Example 1 except that a back layer was not applied.

Example 5 A heat-sensitive recording material N[L5 was prepared in the same manner as in Example 2 except that the protective layer in Example 2 was not applied.

Comparative Example 1 A thermosensitive recording material sample No. 6 was prepared in the same manner as in Example 1 except for the components according to the present invention in the coating liquid composition of the back layer in Example 1.

Comparative Example 2 A heat-sensitive recording material sample 7 was prepared in the same manner as in Example 1 except that the back layer in Example 1 was not applied.

Comparative Example 3 Heat-sensitive recording material sample 8 was prepared in the same manner as in Example 1 except that the bank layer and protective layer in Example 1 were not applied.

Comparative Example 4 The coating composition of the anti-slip layer in Example 1 was the same as in Example 1, except that the components according to the present invention were removed, a back layer was applied, and a protective layer was not applied. A heat-sensitive recording material sample A9 was prepared.

Regarding the samples created in each of the above Examples and Comparative Examples, 100 sheets of test patterns with 25% of the screen are black were printed using Model A and Model B, which are particularly prone to jamming due to static electricity among commercially available facsimiles. We investigated how many pages would cause jamming by printing continuously. Printing was performed at a temperature of 15C and relative humidity.1. If jamming occurred, the paper was removed and the printing test continued.

As a result, the results shown in Table 1 were obtained.

Table 1 From the results shown in Table 1, it can be seen that the samples in each Example, which are the heat-sensitive recording materials of the present invention, had fewer jammed sheets in both Model A and Model B than the samples in Comparative Examples. was clear.

〔Effect of the invention〕

Claims (1)

[Scope of Claims] A heat-sensitive layer on a support containing a colorless to light-colored dye precursor and a compound that develops a color by reacting with the dye precursor, or a diazo compound and a component that develops a color by reacting with the diazo compound. A heat-sensitive recording material comprising a heat-sensitive layer containing a compound represented by the following general formula (I). General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1 to R_4 are alkyl groups with 1 to 20 carbon atoms or aryl groups with 6 to 30 carbon atoms (each forming a ring) ), M represents a halogen atom.)