JPH0464484A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a thermal recording material generating no stickiness and refuse adhesion trouble and excellent in head matching properties by adding colloidal pseudoboehmite to a thermal color forming layer based on a leuco dye and a developer. CONSTITUTION:In a thermal recording material utilizing the color forming reaction of a leuco dye and a developer, colloidal pseudoboehmite is contained. Colloidal pseudoboehmite is amorphous aluminum hydroxide as compared with boehmite being crystalline in general and used as a filler for an inorg. fiber, papermaking or cosmetics and contained in an amount of 10-90% by wt. of a thermal color forming layer and 10-90% by wt. of a protective layer or 10-90% by wt. of both layers but pref. contained in an amount of 30-50% by wt. of the thermal color forming layer and 30-50% by wt. of the protective layer or 30-50% by wt. of both layers because effect is still more developed.

Description

[Detailed Description of the Invention] [Prior Art] Thermosensitive recording materials generally have a thermochromic layer containing a thermochromic composition as a main component on a support such as paper, synthetic paper, or plastic film. A colored image can be obtained by heating with a thermal pen, laser light, etc. Compared to other recording materials, this type of recording material does not require complicated processing such as development and fixing, and records can be obtained in a short time using relatively simple equipment, and it generates less noise and pollutes the environment. Due to its advantages such as low cost and low cost, it is used not only for copying books and documents, but also as a recording material in a wide range of applications such as electronic computers, facsimile machines, ticket vending machines, labels, and recorders.

Thermal color-forming compositions used in such isothermal recording materials generally consist of a color former and a color developer that causes the color former to develop color when heated.As the color former, for example, lactone, lactam or spiropyran ring is used. Colorless or light-colored leuco dyes are used, and various acidic substances such as organic acids and phenolic substances are used as color developers. Recording materials that combine this color forming agent and color developer have the advantage that the resulting image has a particularly clear color tone, has a high background whiteness, and has excellent weather resistance, and is widely used. has been done.

In recent years, as heat-sensitive recording materials have replaced other conventional recording methods and demand for them has increased, there has also been an increasing demand for improving the quality of heat-sensitive recording materials used in these heat-sensitive recording methods. There is a need for a heat-sensitive recording material that is trouble-free and has excellent head matching properties that do not affect head life.

As a method for improving head matching properties, many methods are known in which organic or inorganic fillers are used. For example, Japanese Patent Publication No. 57-20918 describes a method using water-insoluble urea-formalin resin fine powder;
No. 198 and Japanese Patent Publication No. 21030 disclose a method using amorphous silica, Japanese Patent Application Laid-Open No. 59-155095 discloses a method using calcium carbonate, and Japanese Patent Application Publication No. 59-155097 discloses a method using activated clay exhibiting oil absorption in a specific range. Although methods using calcined kaolin have been disclosed, the current situation is that neither method has been able to provide sufficiently satisfactory results.

〔the purpose〕

An object of the present invention is to provide a heat-sensitive recording material that is free from sticking and debris adhesion problems and has poor head matching properties.

(Structure) According to the present invention, there is provided a heat-sensitive recording material that utilizes a color-forming reaction between a leuco dye and a color developer, and is characterized in that it contains colloidal pseudo-boehmite.

Colloidal pseudo-boehmite used in the present invention is an amorphous aluminum hydroxide, whereas boehmite is generally crystalline, and is used as a filler for inorganic fibers, paper manufacturing, cosmetics, etc., and is commercially available as Cataloid AS. -1, AS-3
(manufactured by Catalyst Chemical Industry Co., Ltd.), Alumina Sol 100.200
．． 520 (manufactured by Nissan Chemical Industries, Ltd.). The shape is somewhat rod-like, the size is about 100 to 200 people, and an organic or inorganic acid is used as a deflocculant.

The colloidal pseudo-boehmite used in the present invention is effective even when added to the heat-sensitive coloring layer, but if a protective layer is provided, the effect is even more pronounced by adding it to the protective layer. .

In addition, colloidal pseudo-boehmite contains 10 to 9
0% by weight, 10-90% by weight in the protective layer, or 10-90% by weight in both layers, preferably 30-50% by weight in the heat-sensitive coloring layer, and 30-50% by weight in the protective layer.
Or, by containing it in both layers in an amount of 30 to 50% by weight, the effect is further exhibited.

The leuco dyes used in the heat-sensitive layer of the present invention can be applied singly or in combination of two or more, and such leuco dyes include triphenylmethane-based and fluoran-based leuco dyes. Phenothiazine-based, auramine-based, spiropyran-based, etc. are preferred, and specific examples include those shown below.

3.3-bis(p-dimethylaminophenyl)phthalide, 3.3-bis(p-dimethylaminophenyl)-6-
Dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminostyryl, 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminostyryl,
-dimethylaminophenyl)-6-chlorphthalide, bis(p-dimethylaminostyryl)-methyl γ-toluenesulfonate, bis(p-dimethylaminostyryl)-
Methyl henzenesulfonate, methyl bis(p-dimethylaminostyryl)-γ-chlorobenzenesulfonate, methyl bis(p-dimethylaminostyryl)-〇-naphthalenesulfonate, bis(p-dimethylaminostyryl)
-β-Methyl naphthalenesulfonate, 3.3-bis[2
(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethynyl)-4,5,6,7tetrachlorophthalide, 3.6bis(dimethylamino)fluorene-9
-spiro-3'-16'-dimethylamino)phthalide, 3-(4'-diethylamino-2°-methoxyphenyl)-3<(1°'-p-dimethylaminophenyl-1°'-phenyl)ethylene- 2-yl]benzophthalide, 3-(4"-diethylamino-2'-methoxyphenyl)-3-[:(1"-p-dimethylaminophenyl-1"-tolyl)ethylene-2-yl]benzophthalide, 3- (4'-diethylamino-2-methoxyphenyl)-3-C(1"-p-dimethylaminophenyl-1perphenyl)ethylene-2-yl]phthalide, 3-(4'-diethylamino-2'methoxyphenyl) enyl) -3-C(4''-p-dimethylaminophenyl-4''-phenyl-1''3-per-butadien-1-per-yl]phthalide, 3-(4'-diethylamino-2'-methoxyphenyl)3 -1: (4'"-p-dimethylaminophenyl-4''-p-tolyl-1", 3'"-butadien-1"yl]phthalide, 3-(4'-diethylamino-2'-methoxyphenyl) )−3−C(4“°−
p-Dimethylaminophenyl-4"-p-chlorophenyl-1-3'-butadien-1'-yl]benzophthalide, 3-(4'-diethylamino-2'-methoxyphenyl)-3-C(4"-p-dimethylaminophenyl-4"-p-phenyl-1°"3"-7'
Tadiene-1peryl]benzophthalide, 2-methyl-
3-chloro-6-(p((p-phenylaminophenyl)amino]phenyl)anilinofluorane, 3,3-bis(p-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6-chlorofluoran, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-
7-methylfluorane, 3-diethylamino-7,8-
Benzfluorane, 3-diethylamino-6-methyl-
7-chlorofluorane, 3-(N-p-tolyl-N-ethylamino)-6-methyl-7-anilinofluorane,
3-pyrrolidino-6-methyl-fuanilitufluorane, 2-(N-(3'-1lifluoromethylphenyl)amino)-6-dinithylaminofluorane, 2-(3,6
-bis(diethylamino)-9-(o-chloroanilino)xantylbenzoic acid lactam), 3-diethylamino-6-methyl-7-(m-trichloromethylanilino)fluoran, 3-diethylamino-7-(o-chloroanilino) Fluoran, 3-dibutylamino-7-(o
-chloroanilino)fluoran, 3-N-methyl-N-
amylamino-6-methyl-7-anilinofluorane,
3-N-Methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6
-Methyl-7-anilinofluorane, 3- (N,N-
diethylamino)-5-methyl-7-(N,N-dibenzylamino)fluorane, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrylosbilane, 6'-bromo-3'-methoxy- Benzoindolino-virillospiran, 3-(2“-hydroxy-4′-dimethylaminophenyl)-3-(2
'-Methoxy-5'-chlorophenyl)phthalide, 3-
(2'-hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-5'nitrophenyl)phthalide, 3- (2'-hydroxy-4°-diethylaminophenyl) -3=(2'-methoxy -5'-methylphenyl)phthalide, 3-(2'-methoxy-
4'-dimethylaminophenyl)-3-(2'-hydroxy-4-chloro-5-methylphenyl)phthalide,
3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7-(N-benzyl-trifluoromethyl anilino)fluorane, 3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluorane, 3-
Diethylamino-5-chloro-7-(α-phenylethylamino)fluoran, 3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamine-7-(o-methoxy carbonylphenylamino)fluoran, 3-diethylamino-5
-Methyl-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-piperidinofluorane,
2-chloro3-(N-methyltoluidino)-4-(p
-n-butylanilino)fluoran, 3-(N-pencyl-N-cyclohexylamino)-5,6-penzo 7
-α-naphthylamino-4'-bromofluorane, 3-
diethylamino-6-methyl-7-mesitidino 4',
5''-benzofluorane, 3-diethylamino-6-methyl-7-(2',4'-dimethylanilino)fluoran, etc.

In addition, as the coloring agent used in combination with the above-mentioned leuco dye in the present invention, various electron-accepting compounds or oxidizing agents that cause the above-mentioned leuco dye to catalytically develop color are conventionally known. Specific examples include inorganic acids, organic acids, phenolic substances, and phenolic resins as shown below.

Bentonite, zeolite, acid clay, activated clay, silica gel, phenolic resin, 4,4"-isopropylidene bisphenol, 4,4'-isopropylidene bis(0
-methylphenol), 4.4"-7candalybutylidene bisphenol, 4,4" -isopropylidene bis(〇-tert-butylphenol), 4.4'
~Cyclohexylidene diphenol, 4,4'-isopropylidene bis(2-chlorophenol), 2.2"
Methylenebis(4-methyl-6-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl-2-methyl)phenol, 1,1.3-
1 Lis(2-methyl-4-hydroxy-5-tert-butylphenol)butane, 1,1.3-1 Lis(2-methyl-4-hydroxy-5-tert-butylphenol)
-Methyl-4-hydroxy-5-cyclohexylphenyl)butane, 4,4'-thiobis(6-tert-butyl-2-methyl)phenol, 4,4'-diphenolsulfone, 42'-diphenolsulfone , 4-isopropoxy-4'-hydroxydiphenylsulfone, 4
-benzyloxy-4"-hydroxydiphenyl sulfone, 4,4'-diphenol sulfoxide, isopropyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1 .7-bis(4-hydroxyphenylthio)-3,5-dioxahebutane, 1,5-bis(4-hydroxyphenylthio)
-3-oxapentane, 1,3bis(4-hydroxyphenylthio)-propane, 2,2'-methylenebis(4
-ethyl-6-shabutylphenol), 1,3-bis(4-hydroxyphenylthio)-2-hydroxypropane, N,N"-diphenylthiourea, N,N'-di(m-chlorophenyl)thiourea, salicylanilide,
5-chlorosalicylanilide, salicyl-〇-chloroanilide, 2-hydroxy-3-naphthoic acid, antipyrine complex of zinc thiocyanate, 2-acetyloxy-3-
Zinc salts of naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-hydroxy-1-naphthoic acid, metal salts of hydroxynaphthoic acid such as zinc, aluminum, calcium, etc.
Bis-(4-hydroxyphenyl)acetic acid methyl ester, bis-(4-hydroxyphenyl)acetic acid benzyl ester, 1,3-bis(4-hydroxycumyl)benzene, 1,4-bis(4-hydroxycumyl) Benzene, 2
, 4'-diphenolsulfone, 3,3'-diallyl-
4,4゛-diphenolsulfone, α, α-bis(4
-hydroxyphenyl)-α-methyltoluene antipyrine complex of zinc thiocyanate, tetrabromobisphenol A, tetrabromobisphenol S, 3゜4-dihydroxy-4゛-methyldiphenylsulfone, etc.

In the present invention, when a leuco dye and a coloring agent are bonded and supported on a support to obtain a heat-sensitive recording material, various conventional binders can be used as appropriate. Specific examples of such binders include the following.

Polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide/acrylic acid ester copolymer, acrylamide/acrylic acid ester/
In addition to water-soluble polymers such as methacrylic acid terpolymer, styrene/maleic anhydride copolymer alkali salt, isobutylene/maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, and casein, polyacetic acid Emulsions such as vinyl, polyurethane, polyacrylic acid ester, polymethacrylic acid ester, vinyl chloride/vinyl acetate copolymer, ethylene/vinyl acetate copolymer, styrene/butadiene copolymer, styrene/butadiene/acrylic copolymer latex, etc.

Furthermore, when obtaining a heat-sensitive recording material according to the present invention, various heat-fusible substances can be used as a heat sensitivity improver, if necessary, and specific examples thereof include the following compounds.

Fatty acids such as stearic acid and behenic acid, fatty acid amides such as stearic acid amide and palmitic acid amide, fatty acid metal salts such as zinc stearate, aluminum stearate, calcium stearate, zinc palmitate, and zinc behenate, p-benzyl Biphenyl, terphenyl, triphenylmethane, benzyl p-benzyloxybenzoate, β-benzyloxynaphthalene, β-naphthoic acid phenyl ester, 1-hydroxy-2-naphthoic acid phenyl ester, methyl 1-hydroxy-2-naphthoic acid Ethyl, diphenyl carbonate, dibenzyl terephthalate, dimethyl terephthalate, 1,4-dimethoxynaphthalene, 1,4-jethoxynaphthalene, 1゜4-dibenzyloxynaphthalene, 1
．． 2-bis(phenoxy)ethane, 1.2-bis(3-
Methylphenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, 1,4-bis(phenoxy)butane, 1,4-bis(phenoxy)-2-butene, 1.2
-bis(4-methoxyphenylthio)ethane, dibenzoylmethane, 1,4-bis(phenylthio)butane, 1
．． 4-bis(phenylthio)-2-butene, 1,2-bis(4-methoxyphenylthio)ethane, 1,3-bis(2-vinyloxyethoxy)benzene, 1,4-bis(2-vinyloxyethoxy) ) benzene, p = (2-
(vinyloxyethoxy)biphenyl, p-aryloxybiphenyl, p-propargyloxybiphenyl, dibenzoyloxymethane, 1゜3-dibenzoyloxypropane, dibenzyl disulfide, 1.1-diphenylethanol, 1゜1-diphenylpropane. tools, p-
(benzyloxy)benzyl alcohol, 1,3-diphenoxy-2-propatol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N-octadecylcarbamoylbenzene, etc.

Further, in the present invention, auxiliary additive components commonly used in this type of heat-sensitive recording material, such as fillers, surfactants, lubricants, pressure coloration inhibitors, etc., may be used in combination, if necessary. In this case, fillers include, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, and other inorganic fine powders such as surface-treated calcium and silica. , urea-formalin resin, styrene/methacrylic acid copolymer, polystyrene resin, etc. As lubricants, higher fatty acids and their metal salts, higher fatty acid amides, higher fatty acid esters, animal-based , various vegetable, mineral, or petroleum-based waxes.

The heat-sensitive recording material of the present invention is produced, for example, by applying a heat-sensitive layer-forming coating solution containing the above-mentioned components on a suitable support such as paper, synthetic paper, or plastic film and drying it. applied to.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. Note that all parts and percentages shown below are based on weight.

Example 1 (Liquid A) 10% polyvinyl alcohol aqueous solution 20 parts Water 60 parts (B liquid) Bisphenol A p-benzylbiphenyl 10% polyvinyl alcohol aqueous solution (C liquid) 25 parts 20 parts 45 parts 35 parts (Cataroid AS-1 100 parts of 10% polyvinyl alcohol aqueous solution (manufactured by Catalyst Kasei ■) 10 parts of 20% zinc stearate dispersion Disperse each of the above mucilaginous liquids B using a sand mill so that the average particle size is 2 μm or less, (Liquid A) : (Liquid B) A thermosensitive color forming layer forming liquid prepared by mixing at a ratio of =1:2 was prepared with a basis weight of 52 g/rd.
After drying, spread it on high-quality paper so that the amount of cloth becomes 6 g/rd. Next, prepare (Liquid C) as a protective layer forming liquid,
Spread it on the heat sensitive layer so that the coating amount after drying is 3 g/rIf, dry it, and use a super calender to achieve a smoothness of about 5.
The recording material of the present invention was obtained by surface treatment to obtain a recording material of 0.00 seconds.

Example 2 The heat-sensitive recording material of Example 2 was prepared in the same manner as in Example 1, except that Alumina Sol 200 (manufactured by Nissan Chemical Industries, Ltd.) was used instead of Cataloid AS (liquid C). Obtained.

Comparative Example 1 A heat-sensitive recording material of Comparative Example 1 was obtained in the same manner as in Example 1, except that the following (Liquid B) was used instead of (Liquid C) in Example 1.

(Liquid B) Kaolin UW90 10 parts (manufactured by Landau Kogyo Co., Ltd.) 10% polyvinyl alcohol aqueous solution 100 parts 20%
Zinc stearate dispersion 10 parts 12.5% surfactant aqueous solution 32 parts (Interfacial 557H manufactured by Deitz-Hercules) Water
210 parts (disperse the above composition with a sand mill and make liquid B) Comparative Example 2 Same as Comparative Example 1 except that urea-formalin resin powder was used instead of kaolin UW90 in (Liquid B) of Comparative Example 1. A heat-sensitive recording material of Comparative Example 2 was prepared.

Each of the heat-sensitive recording materials obtained as described above was coated using a thermal printing simulator (manufactured by Matsushita Electronic Components), with an applied power of 0.6 W/dot and a current conduction time of 1.8 m5ec.
Line recording time 10m5ec, sub-scanning density 7, 711i
The following table shows the results of printing for 10 m with a ne 7 mm and examining the adhesion of residue and sticking noise.

(Effects) The heat-sensitive recording material of the present invention has less head debris, no sticking, and poor head matching properties.

Claims (4)

[Claims] (1) A heat-sensitive recording material having a heat-sensitive coloring layer containing a leuco dye and a color developer as main components, characterized in that the heat-sensitive coloring layer contains colloidal pseudo-boehmite. (2) A heat-sensitive recording material comprising a heat-sensitive coloring layer containing a leuco dye and a color developer as main components, and a protective layer containing a polymer binder as a main component on the heat-sensitive recording material, in which colloidal pseudo-boehmite is added to the protective layer. A heat-sensitive recording material characterized by containing. (3) Claim 1 characterized in that colloidal pseudo-boehmite is contained in the thermosensitive coloring layer in an amount of 30% to 50% by weight.
The heat-sensitive recording material described. (4) 30% by weight of colloidal pseudo-boehmite in the protective layer
3. The heat-sensitive recording material according to claim 2, wherein the heat-sensitive recording material contains 50% by weight.