JPS639994B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides a chromogen basic triphenylmethane derivative in a thermal paper and carrier composition for thermal printing equipment.
In particular, it relates to a heat-sensitive coating material for such paper, comprising a basic diaryl phthalide derivative and an acidic phenol developer. Basic triphenylmethane dyes, especially the leuco form of the chromogen basic diphenyl phthalane derivatives, which are essentially colorless chromogens, and active acidic developers, especially phenolic compounds and/or such as clays or attapulginate. Color-forming reactions between active inorganic solids are widely used in the field of reproduction and printing processes, for example in the production of transfer and copy papers (Sullivan
No. 3,244,548 and Farnham et al.
U.S. Patent Nos. 3356229 and 3244550 in the name of et al.
(see specification). Two essentially different types of coating compositions for copying and transfer papers are known: pressure-sensitive and heat-sensitive coatings. Pressure-sensitive recording materials are usually surface-coated with compositions in which the chromogenic compound is contained in microscopic pressure-rupturable capsules. These capsules consist of an oily liquid core containing a chromogenic compound and an oil-impermeable bumpy shell; they are made by preparing an emulsion of the chromogen-containing oil in an aqueous solution of gum arabic and gelatin; It is formed by curing a liquid film of gum arabic/gelatin surrounding the drop with formaldehyde. The solid acid developer is contained in the same coating composition but extracapsularly or, if desired, in a separate coating, for example on a second paper in the case of copying material. When localized printing or writing pressure is applied to the material, the gum arabic-gelatin-formaldehyde membrane ruptures and the chromogen liquid is released from the capsule, and the chromogen is then contacted with an active acid developer and pressurized. A colored mark is formed at the site. Pressure-sensitive recording materials are described, for example, in U.S. Pat.
It is disclosed in the specification of No. 2703457. U.S. Pat. No. 3,920,510 discloses that a pressure-rupturable capsule is
A pressure sensitive coating composition for copying paper is disclosed containing a solution of a chromogenic fluoran compound in monoisopropyldiphenyl surrounded by a hardened gum arabic-gelatin-formaldehyde film. In the production of thermosensitive compositions, the formation of microcapsules is not necessary. Instead, both the chromogenic compound and the phenolic developer are distributed in the form of a finely divided solid in a carrier or binder, especially polyvinyl alcohol. Localized heating fluidizes one of the color-forming reactants, usually a phenolic compound, thus creating intimate contact between the two color-forming reactants and causing the color-forming reaction to be localized to the heating site at the thermal printing temperature. exist and occur. A thermal recording material containing a chromogen compound and a color developer compound distributed in a polyvinyl alcohol coating composition is disclosed in U.S. Pat. No. 3,920,510;
No. 3539375 and No. 3674535. Polyvinyl alcohol, a nonionic water-soluble polymer, is the most commonly used carrier-binder component in thermal coating compositions for thermal printing. Other additives may also be used, such as gum arabic, as disclosed in US Pat. No. 4,168,845. In addition to the undesirable degree of pressure sensitivity of the coated paper, conventional heat-sensitive coating compositions and thermal printing papers coated with these heat-sensitive coating compositions have a tendency to premature self-coloring and environmental stability, i.e. heat, humidity and light. There are various drawbacks, such as lack of stability. Also, these thermal coating compositions cannot be coated on commercial grade paper without loss of performance. A problematic material characteristic is the tendency of the coated paper to not move freely and stick to the printing head during the thermal printing process. US Pat. No. 4,168,845 describes an attempt to alleviate this problem by adding pigments with specific oil absorption values to the composition. The object of the present invention is to provide a heat-sensitive recording material for thermal printing devices, in particular a heat-sensitive paper sheet and a heat-sensitive coating material therefor, which have excellent printing and storage properties. In particular, it is an object of the present invention to substantially eliminate any tendency of paper to stick during the thermal printing process due to melting or softening of the paint under heat and adhesion of the re-solidified paint to the printing head, and yet during the printing process. An object of the present invention is to provide a coated thermal paper that ensures free movement of the paper. Another object of the invention is to provide such thermal paper which substantially reduces noise levels during the printing process. Another object of the invention is to provide a coated thermal paper that has virtually no tendency to warp during slitting. Another object of the invention is to provide a coated thermal paper with excellent moisture stability. Another object of the present invention is to provide a thermal paper with increased color sensitivity at normal thermal printing temperatures that produces intense color images. Another object of the present invention is to provide a thermal paper that has a high degree of whiteness and a high degree of storage stability under normal storage conditions for any thermal product. Another object of the invention is to provide a pressure sensitive paper that does not exhibit an undesirable degree of pressure sensitivity. Another object of the present invention is to provide thermal paper and thermal coating compositions that significantly eliminate self-coloring and undesirable sheet coloring. Another object of the present invention is to produce a thermally sensitive coating formulation which exhibits significantly longer life and lower viscosity at higher concentrations which facilitates uniform coating of paper with water, yet exhibits good drying properties after application to paper. It is to provide a covering. To achieve the said object, according to the present invention, a chromogenic basic 3,3-bisaryl phthalate derivative of a finely divided solid in a color-forming amount and at least partially flowable at the thermal printing temperature and substantially a color-developing amount of a finely divided powder capable of color-forming reaction with a chromogenic 3,3-bisarylphthalane derivative distributed in a carrier composition comprising a water-soluble anionic polysaccharide gum and a stability-enhancing amount of sucrose benzoate; A heat-sensitive coating material is provided that includes a solid phenol derivative. The carrier composition further comprises lead, zinc, cadmium, and alkaline earth metal di(lower alkyl)dithiocarbamates and lower alkylxanthates and tetra(lower alkyl)thiuram disulfides and di(lower alkyl)xanthogens. It may also contain a filler selected from the group consisting of: Moreover, this carrier composition further contains a high molecular weight polymer selected from the group consisting of ultrafine polyolefin and ultrafine modified polyolefin. Heat-sensitive coating materials and coated papers for thermal printing of good quality, especially long life and stability, contain substantial amounts of the chromogenic bisaryl phthalane derivatives and color-developing phenols used therein. A binder comprising a sugar gum and a substantially water-soluble anionic polymeric binder that is sucrose benzoate.
It has been found that this can be obtained when incorporated into a carrier composition. The chromogen base that can be used in the present invention has the following structure: It is an arylphthalane derivative containing a compound having a 3,3-bisphenylphthalane element (in the formula, the benzene nucleus may be further substituted).
These chromogenic compounds are known in the art and include those disclosed in US Pat. No. 3,560,229 and US Pat. No. 4,168,845. Examples of particularly suitable chromogenic compounds include the formula [In the formula, R ₁ and R ₂ may be the same or different and represent hydrogen or lower alkyl, R ₃ and R ₄ each represent hydrogen, or
R ₃ and R ₄ together represent oxo, R ₅ and R ₆ each represent hydrogen or together represent oxo, A is hydrogen or

[Formula] represents a group in which R ₁ and R ₂ are as defined above;
is hydrogen or, if R ₅ and R ₆ are hydrogen, preferably in the p position and

[Formula] represents a group (in which R ₁ and R ₂ are as defined above) or an O-R ₇ group (in which R ₇ is lower alkyl), or R ₅ and R ₆ are When taken together to show oxo, it is preferably at the m position.

[Formula] Group (wherein R ₁ is as defined above, R ₈ is hydrogen, lower alkyl, phenyl,
or phenyl substituted by halogen, preferably chlorine or lower alkyl, preferably methyl), R ₉ and R ₁₀ may be the same or different, and methyl or halogen, especially chlorine or bromine, and n and m may be the same or different and represent a number between 0 and 3]. Chromogenic compounds within the above group include 3,3-bis(p-di(lower alkyl)aminophenyl)phthalide and 3-diethylamino-7, optionally having a further di(lower alkyl)amino group in the phthalide core.
-(p-chloroanilino)fluorane-like 3
-di(lower alkyl)amino-7-anilino-fluorane. Another group of particularly suitable chromogenic basic 3,3-bisarylphthalane derivatives includes an aryl group of the formula (wherein R ₁ and
R ₃ represents hydrogen or lower alkyl preferably containing from 1 to 4 carbon atoms, especially methyl; R ₂ and R ₄ which may be the same or different represent hydrogen or preferably containing from 1 to 4 carbon atoms lower alkyl containing atoms, in particular ethyl or methyl, and R ₅ and R ₆ each represent hydrogen or R ₅
and R ₆ taken together represent oxygen) are heterocyclic basic aryl groups, such as indole groups. A variety of phenol derivatives useful as developer reagents in heat-sensitive coating materials are known in the art. In order to obtain stable materials, the phenols must be solids and exhibit only a small vapor pressure at room temperature. There must be. Nevertheless, in order to obtain intimate contact between the phenol and the chromogen compound and for the color reaction to occur at the heating site, this phenol must at least partially liquefy and/or evaporate at typical thermal printing temperatures. There must be. Suitable phenolic compounds include alkyl and/or aryl substituted monophenols, diphenols and triphenols. Examples of suitable phenols are given in U.S. Pat.
No. 3539375, No. 3244548 and No. 3244550. Preferred phenol derivatives have the formula (wherein D is a bond or preferably 1 to 4
lower alkylidene groups having up to 3 carbon atoms,
Especially methylene, isopropylidene, or 2,2
-butylidene or 1,1-cyclohexylidene, the OH group is in the ortho or preferably para position to D, and R ₂ and R ₄ , which may be different but are preferably the same, are hydrogen, halogen, especially chlorine or bromine,
preferably lower alkyl having 1 to 4 carbon atoms, especially methyl or tert-butyl or hydroxy, which may be different but preferably the same
(R ₁ and R ₃ represent methyl or halogen, especially chlorine or bromine) bis-phenols. 4,4'-isopropylidene bis-phenol is particularly preferred. Other suitable phenolic compounds include naphthol, lower alkyl substituted phenols such as tert-
There are butylphenols, phenyl-substituted phenols and phenoxy-substituted phenols. As is known to those skilled in the art, the chromogen compound or mixture thereof and the type of phenol used will of course depend on the desired color of the colored mark produced on the thermal paper during thermal printing. Similarly, the amounts of chromogen compound and developer phenol will vary widely depending on the type of compound used and the desired color shade and color intensity in the produced colored mark. For example, to obtain the blue mark, 3,3-bis(p-dimethylaminophenyl), known as "brilliant violet leuco"
4, known as phthalide and bisphenol A.
The combination of 4'-isopropylidene diphenol is preferred. Satisfactory results show that from about 9% to about 30% by weight, preferably from about 10% to about 15% by weight of 3,3-bis(p-dimethylaminophenyl) with respect to the amount of solids in the coating material. phthalide and from about 16% to about 36% by weight, preferably about 30% by weight
obtained with a coating material containing from % to about 35% by weight of bisphenol A. Both the chromogenic compound and the phenol must be distributed in the coating in finely divided form, preferably in the form of particles having a particle size of about 1 micron to about 3 microns. The substantially water-soluble anionic polysaccharide modified by the addition of a stabilizing amount of sucrose benzoate as binder-carrier material in the carrier composition provides excellent properties, especially in the wet formulation of the coating material. It has been found that great stability is afforded not only to coating materials but also to coating materials and coated papers. The amount of substantially water-soluble anionic polysaccharide gum and sucrose benzoate in the carrier composition depends, for example, on the desired viscosity of the liquid formulation of the composition and/or the desired amount of the composition to be applied to the recording material. change. Satisfactory results have been obtained with respect to the total solids content in the coating material from about 16% to about 50% by weight, preferably about 30% by weight.
% to about 35% by weight of a substantially water-soluble gum and from about 3% to about 10% by weight, preferably from 5% to about 8% by weight of sucrose benzoate. Substantially water-soluble anionic polysaccharide gums that can be used as binders and carrier materials in carrier compositions according to the invention include gum arabic and varying amounts of gum karaya, water-soluble alginates,
There are agar and agaroid gum, caragee and carrageenan and carboxymethylcellulose. By varying the amount of other substantially water-soluble anionic polysaccharide gums combined with gum arabic, the viscosity of the composition can be easily controlled to any desired level. Even when used in relatively high concentrations, gum arabic is particularly effective since it does not cause an excessive increase in the viscosity of the aqueous formulation of the coating material, yet facilitates the application and drying of the coating on paper. Thermal papers made with coating materials containing substantial amounts of gum arabic, for example 30% by weight or more, exhibit good color development and excellent printing behavior, such as low residue and low print disturbances. Suitably, the pressure sensitive coating material further contains functional fillers which serve to reduce noise levels and tendency to stick. As a functional filler, the general formula (wherein X represents a bond or a metal selected from the group consisting of lead, zinc, cadmium, and alkaline earth metals, and Y represents lower alkyloxy or lower dialkylamino). Such a compound has the formula (wherein Alk represents lower alkyl preferably containing from 1 to 4 carbon atoms, such as for example methyl, ethyl, isopropyl or n-butyl, and Me represents one of the aforementioned metals, preferably zinc. di(lower alkyl)dithiocarbamate of (shown), formula (wherein Alk is as defined above, preferably represents isopropyl or ethyl, Me
is as defined above and preferably represents zinc), a lower alkyl xanthate of the formula (wherein Alk is as defined above and preferably represents methyl), and a tetra(lower alkyl)thiuram disulfide of the formula Di(lower alkyl) dixanthogens (where Alk is as defined above) are suitable. Zinc di-n-butyldithiocarbamate is such a preferred filler that provides additional image enhancement effects. The functional filler is suitably used in an amount of from about 2% to about 12%, preferably from about 5% to about 10% by weight, based on the total solids content of the coating material. Molecular weight from about 1000 to 2000 and from 240〓
Ultrafine polyolefins or ultrafine modified polyolefins having a melting point of up to 700° may be included in the composition. The addition of high molecular weight polyolefins, such as polyethylene or fluorinated polyethylene, to the coating material substantially eliminates the pressure sensitivity of the coated paper and increases its environmental stability while also affecting image quality. It has been found that whiteness can be imparted to the paper sheet without affecting the paper sheet. The high molecular weight polyethylene or fluorinated polyethylene may range from about 2% to about 12% by weight, preferably from about 5% to about 10% by weight, based on the total solids in the material.
Suitably they are contained in the coating material in amounts of up to % by weight. This high molecular weight polyethylene or fluorinated polyethylene is suitably introduced into the material in ultrafine powder form. Preferred heat-sensitive coating materials according to the invention contain from about 9% to about 30%, by weight based on total solids, of a chromogenic compound, preferably 6-dimethylamino 3,3
-bis(p-dimethylaminophenyl)phthalide, from about 16% to about 36% of a phenol derivative, preferably 4,4'-isopropylidene diphenol, from about 16% to about 50% substantially water-soluble an anionic polysaccharide gum, preferably gum arabic, about 3% to about 10% sucrose benzoate, about 2% to about 12% zinc di-n-butyl-dithiocarbamate, and about 2% to about 12% %, from about 240〓 to about 700〓
High molecular weight polyethylene or fluorinated polyethylene with a melting point of up to If desired, the heat-sensitive coating material according to the invention may further contain conventional additives for heat-sensitive coating materials and papers, such as binders, carriers and polyvinyl alcohol, methocell glycowax,
A lubricant such as magnesium stearate may also be included. The coating material according to the invention is a mixture of two separate species;
a chromogenic compound, a chromogenic mixture comprising a portion of a substantially water-soluble anionic polysaccharide gum and other components of the coating, and a phenol and a remaining portion of a substantially water-soluble anionic polysaccharide gum. It may also consist of a color developing mixture containing. Both mixtures may be stored separately and mixed prior to application to the paper, or may be applied separately to the paper to form successive layers of coating on the paper. The heat-sensitive recording sheet material according to the invention comprises a support sheet coated and/or impregnated on one or both of its surfaces with a heat-sensitive material. Preferred support sheet material is 12#/ream to 16
#/ream Up to 17 x 22 x 500 sheets of paper, preferably thin relatively opaque white paper sheets. However, the heat-sensitive material according to the invention can also be applied to a sheet or band of film-like polymeric material, fabric or laminated material to form a heat-sensitive recording material. The paper sheet may be coated and/or impregnated with one or more layers of a single heat-sensitive material containing both a chromogenic compound and a phenol distributed therein, or a phenol and a chromogenic material. The compounds may each be contained in different layers of a multilayer coating, for example paper is coated with a first basecoat of a coating mixture containing the phenol covered with a second coat of the coating mixture containing the chromogenic compound. It may have. Alternatively, a first support sheet coated with a coating mixture containing a phenol is placed in facing relationship with a second support sheet coated with a coating mixture containing a chromogenic compound. Good too. The total amount of coating material based on the support material will vary depending on the specific type of paper and specific materials used as well as the desired printing and processing behavior of the final product. Generally, satisfactory results are obtained with amounts of from about 1.5 g to about 3 g, preferably from about 1.6 g to about 2.75 g, of total coating material based on m ² of support paper. If desired, the thermal paper according to the invention may furthermore have an additional protective coating, for example of a modified copolymer emulsion. Thermal recording sheets according to the invention can be prepared by conventional paper coating methods, for example by coating a support paper with an aqueous dispersion of the coating material by roller, spray brush or other known methods and then drying the coating. manufactured by To prepare an aqueous dispersion of the coating material, a first mixture containing a phenol and a portion of a substantially water-soluble anionic polysaccharide gum and a chromogen compound, the remainder a substantially water-soluble anionic polysaccharide gum. ,
The second mixture containing sucrose bezoate and any other ingredients are each thoroughly triturated with water, suitably at a concentration between about 10% and about 50%, to reduce the solids to several microns. Preferably the average particle size is between about 1 micron and about 3 microns. The two dispersions obtained can be mixed together to form a single coating material which can be applied to paper after dilution, optionally with water. Alternatively, the two dispersions may be applied separately to the paper to form different coating layers. The invention is further illustrated by the following non-limiting examples. Example 1 Thermal Paper for Thermal Printing Devices 1 Preparation of the Coating Material Chromogen mixture of solids with the following composition Gum Arabic 32.96% Copikem 1 ^* 22.20% Butyl Zimate ^** 16.37% Sucrose Benzoate 12.10% MPP-620VF ^*** 16.37% 100.00% and a phenol-containing mixture of solid content having the following composition: Gum Arabic 32.96% Bisphenol A ^**** 67.04% 100.00% are produced. The two mixtures are fed into separate mills. Add water to each of these mixtures to approximately 30% solids. The aqueous mixture is thoroughly milled to reduce the solids content to an average particle size of 1 to 3 microns. The resulting mixtures are combined to form an aqueous formulation of the coating material in which the solids content has the following composition: Gum Arabic 32.96% Copichem 1 ^* 11.10% Butyl Zimate ^** 8.17% Sucrose Benzoate 6.07% MPP-620VF ^*** 8.17% Bisphenol A ^**** 33.53% 100.00% *: Hilton Davis Chemical Company made 6-
Trade name of dimethylamino 3,3-bis(p-dimethyl-aminophenyl) phthalide, **: Zinc di-n-butyldithiocarbamate ***: High molecular weight polyethylene, melting point >500〓 ***: 4,4 '-Isopropylidene diphenol 2 Preparation of thermal paper An aqueous formulation of this coating material is applied in a single layer to a paper sheet and dried in a conventional manner. The amount of coating of the aqueous formulation applied to the paper is adjusted such that the amount of solid coating material based on m ² is 2.1 g. Of course, depending on the end use, it may be possible and desirable to alternatively use multiple layers of developer and color former, techniques known in the art.

Claims (1)

[Scope of Claims] 1. A heat-sensitive coating material suitable for a heat-sensitive printing material or a recording material for a thermal printing device, comprising: a finely powdered solid chromogenic basic 3,3-bisarylphthalane derivative with a color-forming amount and a heat-printing material; a chromogen 3,3-bisaryl distributed in a carrier composition comprising a substantially water-soluble anionic polysaccharide gum that is at least partially flowable at temperature and a stability-enhancing amount of sucrose benzoate; A heat-sensitive coating material suitable for a heat-sensitive printing material or recording material for a thermal printing device, characterized in that it contains a color-developing amount of a finely powdered solid phenol derivative capable of color-forming reaction with a phthalane derivative. 2. The carrier composition further comprises lead, zinc, cadmium and alkaline earth metal di(lower alkyl)dithiocarbamates and lower alkylxanthates and tetra(lower alkyl)thiuram disulfide and di(lower alkyl)xanthogen. A heat-sensitive coating material according to claim 1, comprising a filler selected from the group. 3. Claim 1, wherein the carrier composition further comprises a high molecular weight polymer selected from the group consisting of ultrafine polyolefin and ultrafine modified polyolefin.
The heat-sensitive coating material described in Section. 4. The heat-sensitive coating material according to claim 1, wherein the polysaccharide gum is gum arabic. 5. The heat-sensitive coating material according to claim 2, wherein the filler is zinc di-n-butyl-dithiocarbamate. 6. The heat-sensitive coating material of claim 4, comprising between about 16% and about 50% by weight of gum arabic and between about 3% and about 10% by weight of sucrose benzoate. 7 Additionally between about 2% and about 12% by weight
- zinc butyldithiocarbamate and an ultrafine polyolefin or ultrafine modified polyolefin having a molecular weight of between about 2% and about 12% by weight from about 1500 to 2000 and a melting point of about 240〓 to 700〓. The heat-sensitive coating material according to item 6. 8 Between about 9% and about 30% by weight of chromogen 3,3
-bisarylphthalane derivative and approximately 16% by weight
containing up to about 36% by weight of phenol derivatives,
A heat-sensitive coating material according to claim 7. 9 The chromogen 3,3-bisarylphthalane derivative is 6-dimethylamino-3,3-bis(p-dimethylaminophenyl) phthalide, and the phenol derivative is 4,4'-isopropylidene diphenol. , Claims 1, 2, and 3
The heat-sensitive coating material according to item 1, 4, 5, 6, 7, or 8. 10 Between about 10% and about 15% by weight of 6-dimethylamino-3,3-bis(p-dimethylamino-
phenyl) phthalide, between about 30% and about 35% by weight of gum arabic, between about 5% and about 8% by weight of sucrose benzoate, between about 5% and about 10% by weight.
10. The thermal coating material of claim 9, comprising between % by weight of zinc di-n-butyl-dithiocarbamate and between about 5% and about 10% by weight of a high molecular weight polymer. 11 In a heat-sensitive coating material for a heat-sensitive recording material for a thermal printing device, a fine powder solid basicity with a color development amount of 3,3
-bisarylphthalane derivatives, gum arabic,
A chromogen mixture containing an amount of sucrose benzoate that increases stability and is at least partially flowable at the thermal printing temperature;
- A heat-sensitive coating suitable for heat-sensitive recording materials for thermal printing devices, characterized in that it contains a separate developer mixture containing a developer quantity of a finely divided solid phenol derivative and gum arabic capable of color-forming reaction with bisaryl phthalanes. Materials for manufacturing. 12. The material of claim 11, wherein the chromogen mixture further comprises zinc di-n-butyldithiocarbamate and a high molecular weight polymer selected from the group consisting of polyethylene and fluorinated polyethylene. 13 on at least one surface a color-forming amount of a finely divided solid chromogenic basic 3,3-bisarylphthalane derivative and an anionic polysaccharide gum that is at least partially flowable at the thermal printing temperature and substantially water-soluble. and a heat-sensitive coating material comprising a color-developing amount of a finely divided solid phenol derivative capable of color-forming reaction with a chromogenic 3,3-bisarylphthalane derivative distributed in a carrier composition comprising a stability-increasing amount of sucrose benzoate. A thermal recording sheet for a thermal printing device, comprising a support sheet having the following properties.