SE413646B - SHEET-SIZED MATERIAL INTENDED FOR USE IN A PRESSURE COPYING SYSTEM - Google Patents

Description

u _, '7313139 ~ 3 2 the sheet when the microcapsules break and thereby form a visible, colored image on the underlying sheet. If multiple copies are required, an intermediate sheet provided with the microcapsules on one side and the acceptor on the other side is inserted between the topsheet and the backsheet.

U.S. Pat. No. 2,750,457 further discloses a registration sheet in which both the fine capsules and the acceptor are applied to the same side, i.e. and s.k. copy sheet unit.

German Pat. No. 1,275,550 further discloses a pressure-sensitive recording sheet in which recording-forming components soluble in a liquid solvent are supported on the surface and / or inside a support member, said solvent being present in isolation from at least one of the recording-forming components. by means of capsules which can be caused to break under the influence of pressure. Examples of the color former are the leucotype of chromogenic compounds, such as crystal violet-lactone, benzoyl-leukomethylene blue, malachite green-lactone, rhodamine β-lactone, fluorane derivatives and spiropyrans.

Examples of known acceptors are acid clay, activated clay, applaugite, kaolin and other inorganic solid acids, but in these the disadvantage arises that a developed color image is bleached by the action of moisture and sunlight. A sensitized sheet coated with organic solid acid, such as phenolic resins, was also used. Such a sheet, however, shows a tendency to yellow in the sunlight, and the developed color image decreases in density or is made to disappear for a short time by the action of heat or moisture.

As further examples of an organic solid acid, aromatic carboxylic acids (U.S. Pat. Nos. 3,322,557 and 3,488,207) and polyvalent metal salts of aromatic carboxylic acids are proposed (German Offenlegungsschrift No. 2,152,765). For example, there is described benzoic acid, o-nitrobenzoic acid, o-chlorobenzoic acid, 4-methyl-3-nitrobenzoic acid, p-isopropylbenzoic acid, p-tert-butylbenzoic acid, salicylic acid, 5-tert-butylsalicylic acid, 3-cyclohexylsalicylic acid 5-methyl--5-isoamylsalicylic acid, 3,5-dinitrosalioylic acid, 1-naphthoic acid, 1-hydroxy--2-naphthoic acid, 5,5'-methylene-disalioylic acid and other similar aromatic carboxylic acids and salts of metals, such as magnesium, calcium, zinc, cadmium, aluminum, gallium, tin, lead, chromium, molybdenum, manganese, cobalt and nickel, with the abovementioned carboxylic acids. Such aromatic carboxylic acids and polyvalent metal salts thereof are superior to the phenolic resins in terms of stability to sunlight. Some of the aromatic carboxylic acids and polyvalent metal salts thereof have a sublimation property, so that a sheet sensitized by a coating containing such acceptors loses its color-forming ability over time. Since these acceptors are relatively soluble in water and thus diffuse within the sheet by the action of a high moisture content or water, the color-forming ability is lost on the surface of the sheet. These inconveniences show an increase. tendency as the molecular weight of the aromatic carboxylic acid decreases. The reason why salioylic acid was proposed earlier but not used in practice is that it has the above-mentioned disadvantages and also a weak point with low color density. Some aromatic carboxylic acids and polyvalent metal salts thereof show an improved resistance to heat and moisture as the molecular weight increases, and they can maintain relatively stable color-forming properties at normal temperature and humidity. However, the pressure-sensitive recording papers leave room for practical improvements in the properties required. It is inevitable that the registration papers are stored and handled under such conditions as e.g. high moisture content or in such a way that water happens to come directly onto the sheet.-It often happens, for example, that rainwater or water that is spilled from a glass gets stuck to the sheet. When in some cases a letter or number is printed by means of offset printing on the upper or underlying sheet in pressure-sensitive recording papers, stock solution on the printing felt will be transferred to an acceptor-coated surface on the sheet. If under such conditions an organic acid substance has insufficient resistance to high humidity or water, the color-forming ability of a sensitized sheet will be considerably reduced, or, in the case that the sensitized sheet comes into contact with a sheet containing the encapsulated color former, the organic acid substance will be brought into contact with the color former by means of the moisture or water as carrier, whereby an undesirable color arises, namely so-called smear paint.

Thus, a coating containing the acceptor must have a high resistance to moisture or water, which resistance is sufficient for stability of the color-forming ability and the developed color image to be maintained and further to prevent color saturation. On the other hand, one must carefully monitor a coating composition containing aromatic carboxylic acids and polyvalent metal salts thereof, since these compositions are unstable to heat 1 in general, and they must also be handled with care during storage resp. during the coating process. Especially during the coating process, the coating composition is subjected to mechanical shear, which is accompanied by rising temperature. Thus, when the mechanical and thermal stability is insufficient, the coating composition can not form a uniform layer on the surface of a base sheet, and in the worst case, the application of the coating must be interrupted. If the application of the coating is carried out with the aid of coating apparatus mounted on a paper machine, this is the simplest process, so it is economically advantageous. Since the coating composition in this case is applied to the base sheet heated by a dryer, the requirements for mechanical and thermal stability become stricter.

The present invention thus has for its object to provide a sheet material of the type mentioned in the introduction, which material is characterized in that said coating contains a granular mixture comprising (a) 100 parts by weight of an acidic organic substance selected from the group consisting of aromatic carboxylic acids and polyvalent metal salts thereof, and (b) from 5 to 300 parts by weight of an organic high molecular weight compound selected from the group consisting of polystyrene; styrene copolymer, a-netylstyrenpolymerer, o: ~ -metylstyren- copolymer, polyvinyl chloride, vinylkloridsampolymerisat, vinylidene kloridsampolymerisat, polychloroprene, cyklopentadienpolymerer, cyclopentane tadiensampolymerisat, acrylic ester polymers, akrylestersampolymerisat, akrylsyrasampolymerisat, metakrylesterpolymerer, metakrylestersampoly- merisab, methacrylic acid copolymers, vinyl acetate polymers, vinyl acetate sampolymeriaat, such as ethylene-vinyl acetate copolymer, acrylonitrile copolymer, dcrylamide copolymer, allyl alcohol copolymer, benyl chloride-copolymer condensation products, benzyl chloride copolymer condensation products, methacylene-formaldehyde condylene condensate; a molecular weight of at least 400, is non-flowing at ordinary temperature and is compatible with said acidic organic substance.

As mentioned above, the acidic organic substance is selected from the group consisting of aromatic carboxylic acids and polyvalent metal salts thereof. These compounds are illustrated by non-limiting examples below, but it should of course be understood that other aromatic carboxylic acids and polyvalent metal salts thereof, which can effect color formation when contacted with a color former, may also be used.

An aromatic carboxylic acid for use is represented by the formula (I): COOH (I) wherein each of the designations R 1, H 2, H 3, H 4 and H 5 represents hydrogen, halogen or a hydroxyl, amino, carboxyl, carbamoyl, N-substituted carbamoyl, alkyl, cycloalkyl, alkoxyl, aryl, aryloxy, arakyl or alkylaryl group, and any pair of adjacent substituents R1 to R5, together with the carbon atoms to which they are attached, can complete a ring, e.g. and naphthalene ring. Compounds of formula I, wherein B1 or R5 is a hydroxyl group, are particularly important in embodiments of the invention, as will be seen in more detail below.

Examples of aromatic carboxylic acids of the formula I in which R1 and R5 are not a hydroxyl group are benzoic acid, o-toluic acid, m-toluic acid, p-toluic acid, p-tert-butylbenzoic acid, o-chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, dichlorobenzoic acid, trichlorobenzoic acid, tetrachlorobenzoic acid, phthalic acid, isophthalic acid, terephthalic acid, 2-carboxybiphenol, p-oxybenzoic acid, paramethoxybenzoic acid, p-butoxybenzoic acid, p-octoxybenzoic acid, bile acid, monoamide 5-tert-butyl-4-hydroxybenzoic acid, 3-cyclohexyl-4-hydroxybenzoic acid, 3-phenyl-4-hydroxybenzoic acid, 3- (α-methylbenzyl) -4-hydroxybenzoic acid, 3,5-dimethyl-4 -hydroxybenzoic acid, trimellitic acid, pyromellitic acid, α-naphthoic acid, sanzanaphthoic acid, tetrachlorophthalic acid and 2,2'-dicarboxidiphenyl.

Aromatic carboxylic acids of the formula I, in which H1 or H5 is a hydroxyl group, are defined by the formula II: 17313139-3 6 '~ 1 coon 119 oH (II) Rs _ Re E? where H6 to R are the same as R1 to R5 in formula I.

Examples of these carboxylic acids which may be mentioned are salioylic acid, o-cresotic acid, p-cresotinic acid, 3-ethylsalicylic acid, 4-ethylsalicylic acid, 3-isopropylsalioylic acid, 4-isopropylsalioylic acid, 5-1-isopropylsalioyl-tert-acid, 3-butsalicylic acid. -butylsalicylic acid, 5-cyclohexylsalioylic acid, 5-cyclohexylsalioylic acid, 5-phenylsalicylic acid, 5-phenylsalicylic acid, 3-benzylsalicylic acid, 5-tert-octylsalioylic acid, 5- (1-methyl-benzyl) -yl) -yl èsalicylic acid, 5-nonylsalicylic acid, 5- (α, α-dimethylbenzyl) -salicylic acid, 5-chlorosalicylic acid, 5-butoxy-salioylic acid and 5-octoxysalioylic acid.

Compounds of formula II, wherein R 6 and R 8 are halogen, alkyl, cycloalkyl, aryl, aralkyl or alkylaryl, can be readily prepared on a commercial scale from phenols, alkylphenols, arylphenols or halogenated phenols. Examples of these aromatic carboxylic acids which may be mentioned are 3,5-dichlorosalicylic acid, 3-chloro-5-tert-butylsalioylic acid, 3-chloro-5-tert-amylsalicylic acid, 3-chloro-5-tert-octyl salioylic acid, 3-chloro-5- (α, α-dimethylbenzyl) -salicylic acid, 3,5-dimethylsalicylic acid, 3-methyl-5-tert-bubylsalicylic acid, 3-methyl-5-cyclohexylsalioylic acid, 5- methyl 5-tert-octylsalioylic acid, 3-methyl-5- (α-methyl-benzyl) -salioylic acid, 3-methyl-5-nonylsalioylic acid; 5-methyl-5- (α, α-dimethylbenzyl) -salicylic acid, 5,5-diisopropylsalicylic acid, 3,5-di-sec-butylsalicylic acid, 3-tert-butyl-5-chlorosalicylic acid,} -tert .-butyl-5-methylsalicylic acid, 3-tert-butyl-5-ethyl-salioylic acid, 3,5-di-tert-butylsalicylic acid, 3-tert-butyl-5-cyclohexylsalicylic acid, 3-tert.- -butyl-5-phenylsalicylic acid, 3-tert-butyl-5- (4'-tert-butylphenyl) -salicylic acid, 3-tert-amyl-5-chlorosalicylic acid, 5-tert-amyl-5-methyl salicylic acid, 3-tert-amyl-5-ethylsalioylic acid, 3,5-di-tert-amylsalioylic acid, 5-tert-amyl-5-cyclohexylsalicylic acid, 3-tert-amyl-5-phenylsalicylic acid , 5-tert-amyl-5- (4'-tert-amylphenyl) -salioylic acid, 5-cyclohexyl-5-chlorosalioylic acid, 3-cyclohexyl-5-methylsalioylic acid, 3-cyclohexyl-5-ethylsalicylic acid, 3,5 -dicyclohexylsalicylic acid, 3-cyclohexyl-5-phenylsalicylic acid,} -cyclohexyl-5- (H'-cyclohexylphenyl) -salicylic acid, ya-phenyl-5-chlorosalicylic acid, 3-phenyl-5-isopropylsalicylic acid, 5- tert-butylsalicylic acid, 3-phenyl-5-tert-amylsalicylic acid, 3-phenyl-5-cyclohexylsalioylic acid, 3-phen yl-5-benzylsalicylic acid, 5-phenyl-7313139-3 7 -5-tert-octylsalicylic acid, 3-phenyl-5- (α-methylbenzyl) -salicylic acid, 3-phenyl-5-nonylsalicylic acid, 5-phenyl-5- (α, α-dimethylbenzyl) -salicylic acid, 5-benzyl-5-chlorosalicylic acid, 3-benzyl-5-methylsalicylic acid, 3-benzyl-5-ethylsalioylic acid, 3-benzyl-5-cyclohexylsalicylic acid, 3-benzyl-5 -phenylsalicylic acid, 5,5-dibenzylsalicylic acid, 3-benzyl-5-tert-octylsalicylic acid, 3-benzyl-5-nonylsalicylic acid, 3-benzyl-5- - (α, α-dimethylbenzyl) -salicylic acid, 5-tert. -octyl-5-chlorosalicylic acid, 3-tert-octyl-5-methylsalicylic acid, 5-tert-octyl-5-ethylsalicylic acid, 3-barth-octyl-5-cyclohexylsalicylic acid, 3-tert-octyl-5-phenylsalicyl acid, 3,5-di-tert-octylsalicylic acid, 3- (methylbenzyl) -5-chlorosalicylic acid, 3- (α-methylbenzyl) -5-methylsalicylic acid, 5- (α-methylbenzyl) -5-ethylsalicylic acid , 3- (α-methylbenzyl) -5-cyclohexylsalicylic acid, 5- (α-methylbenzyl) -5-phenylsalicylic acid, 3,5-di (α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5- (a , α-dimethylbenzyl) -salicylic acid, 3- (α-methylbenzyl) -5-bis' - (α-methylbenz syl) -phenylsalicylic acid, 3-nonyl-5-chlorosalicylic acid, 5-nonyl-5-methylsalicylic acid, 5-nonyl-5-ethylsalicylic acid, 3-nonyl-5-phenylsalicylic acid, 3,5-dinonylsalicylic acid, 3- ( α, α-dimethylbenzyl) -5-chlorosalicylic acid, 3- (α, α-dimethylbenzyl) -5-methylsalicylic acid, 3- (α, α-dimethylbenzyl) -5-ethylsalicylic acid, 3- (α, α-dimethylbenzyl) -5- -t-amylsalicylic acid, 3- (α, α-dimethylbenzyl) -5-cyclohexylsalicylic acid, 3- (α, α-dimethylbenzyl) -5-phenylsalicylic acid, 3- (α, α-dimethylbenzyl) -5- - ( α-methylbenzyl) -salicylic acid, 3,5-di- (α, α-dimethylbenzyl) -salicylic acid, 3- (4'-tert-butylphenyl) -5-tert-butylsalicylic acid,} - (4'-cyclohexyl- phenyl) -5-cyclohexylsalicylic acid and 3-[1- (α, α-dimethylbenzyl) -phenyl} -5- (α, α-dimebylbenzyl) -salicylic acid.

Aromatic carboxylic acids of the formula II in which R7 or R9 are alkyl, cycloalkyl or phenyl can be obtained from, for example, methacresol, metapropylphenol, metaphenylphenol, 2,3-xylenol, 2,5-xylenol, 3,4-xylenecl and 3, 5 ~ xyleno1. Examples of such carboxylic acid tubes are 3,4-dimethylsalicylic acid, 4,5-dimethylsalicylic acid, 4,6-dimethylsalicylic acid, 4-methyl-5-isopropylsalicylic acid, 4-methyl-5-sec-butylsalicylic acid, 4-methylsalicylic acid. 5-tert-butylsalicylic acid, 4-methyl-5-tert-amylsalicylic acid, 4-methyl-5-cyclohexylsalicylic acid, 4-methyl-5-benzylsalicylic acid, 4-methyl-5-tert-octylsalicylic acid, 4-methyl-5-methylsalicylic acid - (α-methylbenzyl) -salicylic acid, 4-methyl-5-nonylsalicylic acid, 4-methyl-5- (α, α-dimethylbenzyl) -salicylic acid, 5,6-dimethylsalicylic acid, 3-tert-butyl-6-methylsalicylic acid, 3-tert-amyl-6-methylsalicylic acid, 5-cyclohexyl-6-methylsalicylic acid, 5-tert-octyl-6-methylsalicylic acid, fw (α-methylbenzyl-6-methylsalicylic acid, δ-diisopropylsalicylic acid, .dzutyl-β-isopropylsalicylic acid, 3-heme; -okyl-β-α-isopropyl-salicylic acid, j- (α-dimethylbenzyl) -O-isupzopylsalicylic acid, 3-tert-α, β-z1z1z9-z8-butyl-6-phenylsalicyl , 3-tert-amyl-6-phenylsalicylic acid, 3-cyclohexyl-6-phenylsalicylic acid, 3-tert-octyl-6-phenylsalicylic acid, 3- (α-methylbenzyl) -6-fe nylsalicylic acid or 3- (α, α-dimethylbenzyl) -6-phenylsalicylic acid.

Aromatic carboxylic acids of formula II, in which at least one of the radicals R6 to R9 is a hydroxyl group, are represented by the formula III: coon ou (111) (mn ¶ mmm 1 which m represents 1 or 2, n represents a whole numbers from 0 to 3 and R is an alkyl, cycloalkyl or aralkyl group, Examples of these carboxylic acids are 3-hydroxyalicylic acid, 3-hydroxy-5-tert-butylsalicylic acid, 3-hydroxy-5-tert-amylsalicylic acid , -hydroxy-5-cyclohexylsalicylic acid, 5-hydroxy-5-tert-octylsalicylic acid, 3-hydroxy-5- (o-methylbenzyl) -salicylic acid, 3-hydroxy-5- (α, α-dimethylbenzyl) -salicylic acid, 3-hydroxy-4,6-dicyclohexylsalicylic acid, 4-hydroxy-salicylic acid, 4-hydroxy-5-tert-butylsalicylic acid, 4-hydroxy-5-tert-amylsalicylic acid, 4-hydroxy-5-cyclohexylsalicylic acid 4-hydroxy-5-tert-octylsalioylic acid, 4-hydroxy-5- (α-methylbenzyl) -salicylic acid, 4-hydroxy-5- (α, α-dimethylbenzyl) -salicylic acid, 5,5-diisopropyl-6- hydroxyisalicylic acid, 5,5-di-tert-butyl-6-hydroxysalicylic acid, 3,5-di-tert-amyl-6-hydroxysal ioyl acid, 5,5-dicyclohexyl-6-hydroxysalicylic acid, 5,5-di- (α-methylbenzyl) -6-hydroxysalicylic acid, 3,5-di- - (α, α-dimethylbenzyl) -6-hydroxysalicylic acid , 5-hydroxysalicylic acid, 4-tert-butyl-5-hydroxysalioylic acid, 4-tert-amyl-5-hydroxysalicylic acid, 4-cyclohexyl-5-hydroxysalicylic acid, 4- (α-methylbenzyl) §5-hydroxysalicylic acid , 5,6-diisopropyl-5-hydroxysalicylic acid, 3,6-dicyclohexyl--5-hydroxysalicylic acid or 3,6-di (α-methylbenzyl) -5-hydroxysalicylic acid.

In the case where an arbitrarily adjacent pair of the radicals H6 to R form a ring together with the carbon atoms to which they are attached, the naphthalene derivatives are obtained. They are represented by the formulas IV, V and VI: 7313139-3 (IV) We RU »n'7 1 cooH \\ (V) // R'6 I 'on R 5 R 1 P RIB RIB IR 7 R u \ (VI) 1 / 'n'6 coon R'5 oH o where each of the radicals R'1, R'2, R'3, R'4Q R'5, R'6, R'7 and R '8 is hydrogen or halogen or a hydroxyl, alkyl, cycloalkyl or aralkyl group. Examples of such naphthalene derivatives are 1-hydroxy-2-carboxinaphthalene, 1-hydroxy-2-carboxy-4-isopropyl-naphthalene, 1-hydroxy-2-carboxy-4-cyclohexylnaphthalene, 1-hydroxy-2--carboxylate 4-benzylnaphthalene, 1-hydroxy-2-carboxy-4- (α-methylbenzyl) -naphthalene, 1-hydroxy-2-carboxy-7-isopropylnaphthalene, 1-hydroxy-2-carboxy-oxy-7-tert.- butylnaphthalene, 1-hydroxy-2-carboxy-7-tert-amyl-naphthalene, 1-hydroxy-2-carboxy-1-cyclohexylnaphthalene, 1-hydroxy-2-carboxy-7-tert-octylnaphthalene, 1-nitroxy-2-xarbox1_7_ (α-methyl-benzyl) -naphthalene, 1-hydroxy-2-carboxy-7- (α, α-dimethylbenzyl) -naphthalene, 1-hydroxy-2-carboxy-4,7-diisopropylnaphthalene, 1-hydroxy-2- -carboxy-4,7-di-tert-butylnaphthalene, 1-hydroxy-2-carboxy-4,7-di-tert-amylnaphthalene, 1-hydroxy-2-carboxy-4,7-dicyclohexylnaphthalene, 1- hydroxy-2-carboxy-4,7-dibenzylnaphthalene, 1-hydroxy-2-carboxy-4,7- «ry3131z9-3-di-tert-octylnaphthalene, 1-hydroxy-2-carboxy-4,7-di (α-methylbenzyl) -naphthalene, 1-hydroxy-2-carboxy-4,7-di (α, α-dimethylbenzyl) -naphthalene, 1-carboxy-2-hydro xinaphthalene, 1-carboxy-2-hydroxy-3,6,8-tri-tert.-butyl-naphthalene, 2-hydroxy-3-carboxinaphthalene, 2-hydroxy-5-carboxy-6,8-di-tert .-butylnaphthalene, 2-hydroxy-3-carboxy-6,8-di-tert.-amylnaphthalene, 2-hydroxy-3-carboxy-6,8-dicyclohexylnaphthalene, 2-hydroxy--3-carboxy-6, 8-di-tert-octylnaphthalene, 2-hydroxy-3-carboxy-6,8-di- (α-methylbenzyl) -naphthalene and 2-hydroxy-3-carboxy-6,8-di (a, audi- methylbenzyl) -naphthalene. Aromatic carboxylic acids derived from, for example, bisphenol A, 4,4'-diylaroxyl cyclohexylidene biphenyl, 4,4'-amyroxyl-methylenebiphenyl and 2,2'-dihydroxydiphenyloxide are considered as condensates of salicylic acid. Examples of these carboxylic acids are 5- (4'-hydroxybenzyl) -salicylic acid, 5- (3'-carboxy-4'-hydroxybenzyl) -salicylic acid- (mecylene-tais-salieylsyz-a), jscert. -butyl-5- (3 ', 5'-α-tert-butyl-11-hydroxybenzyl) -salicylic acid, 5- (α, α-dimethylbenzyl) L5-ii', 5'-di (a , α--dimethylbenzyl) -4'-hydroxybenzylsalicylic acid, 3-tert-butyl-5- (α, α--dimethyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzyl) - salicylic acid, 5- (α, α- -dimethyl-3'-carboxy4'-hydroxybenzyl) -salicylic acid, 5- (α, α-dimethyl--4'-hydroxybenzyl) -salicylic acid, 5- (2 ' -hydroxyphenoxy) -salicylic acid, 3- (2'-hydroxy-5'-carboxyphenoxy) -salicylic acid, 3- (2'-hydroxy-5'-carboxy-5'-tert-butylphenoxy) -5-tert-butylsalicylic acid 3- (2'-hydroxy-3 ', 5'-di-tert-butylphenoxy) -5-tert-butylsalicylic acid, 3- {2'-hydroxy-3'-carboxy-5' - (a , α-dimethylbenzyl) -phenoxy-5- (α, α-dimethylbenzyl) -salicylic acid, 3- [2'-hydroxy-3 ', 5'-di (α, α-dimethylbenzyl) -phenoxy]} -5- ( α, α- -dimethylbenzyl) -salicylic acid and 5- (2'-hydroxy-j ', 5'-dicyclohexylphenoxy) -5-cyclohexylsalicylic acid.

Furthermore, a large number of aromatic carboxylic acids of formula II, which can be expressed with difficulty in chemical nomenclature, can be indicated; For example, nama sampolykondensationsprodukter of formaldehyde with salicylic acid or nucleus-substituted salicylic acids and phenols, salicylic acid or nucleus-substituted salicylsyraadditionsprodukter of propylene polymer or isobutylene polymer, salicylic acid or nucleus-substituted salicylsyraadditionsprodukter of benzyl kloridpolykondensationsproduuter, salicylic acid or nucleus-substituted salicylsyraadditionsprodukter of styrene polymers, salicylic acid or nucleus-substituted salicylsyraadditionsprodukter of α-methylstyrene polymers, salicylic acid or nucleus-substituted salioylic acid condensates of aldehydes or aoethylene, salicylic acid or nucleic salicylic acid condensates of kebones and salicylic acid or nucleus-substituted salicylic acid compounds with the addition of compounds.

The terms "aromatic carboxylic acids" and "polyvalent metal salts thereof", as used herein and in the claims, also include the aforementioned condensates and polymers and the polyvalent metal salts thereof. All of the above aromatic carboxylic acids can form salts with polyvalent metals.

Polyvalent metals associated with the acceptors of the present invention represent all of the salt-forming metals except lithium, sodium, potassium, rubidium, cesium and francium. The useful polyvalent metals include magnesium, aluminum, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, strontium, yttrium, zirconium, niobium, molybdenum, silver, cadmium, indium , tin, antimony, barium, tungsten, mercury, lead and bismuth. The most suitable metals for practical use are magnesium, aluminum, calcium, titanium, manganese, zinc and tin.

Among the above-mentioned aromatic carboxylic acids and the polyvalent metal salts thereof, compounds having at least one hydroxyl group on the benzene ring are preferred, especially a hydroxyl group in the ortho position to the carboxyl group due to the color-forming ability of these compounds. From the aspects of heat and moisture resistance as well as compatibility with an organic high molecular weight compound, an aromatic carboxylic acid and a polyvalent metal salt thereof of higher molecular weight are preferred, with those having 10 or more and preferably 17 or more carbon atoms all in all. In particular, there are compounds of formulas II, III, IV, V and VI, in which the 3-position of the carboxyl group is substituted by isopropyl, secondary butyl, tertiary butyl, tertiary amyl, cyclohexyl, phenyl, substituted phenyl, benzyl, d-methylbenzyl , d, d-dimethylbenzyl, tertiary octyl, nonyl and the second group having 3 or more carbon atoms, excellent color-forming properties, stability to water and compatibility with an organic high molecular weight compound. Compounds of formulas II, III, IV, V and VI, which comprise at least one 5- or 6-membered carbon ring as substituent and contain 17 or more carbon atoms all in all are preferred.

The polyvalent metal salts of aromatic carboxylic acids are obtained by reaction between aromatic carboxylic acids and oxides, hydroxides, carbonate and silicate of polyvalent metals, although they are conveniently obtained by a double reaction of an alkali metal salt of an aromatic carboxylic acid and a water-soluble polyvalent metal salt. In this case, the aromatic carboxylic acid resp. the water-soluble polyvalent metal salt may each be used singly or in a mixture of two or more. The polyvalent metal salts of aromatic carboxylic acids are usually obtained in the form of crystalline powders, amorphous fine powders or viscous liquids.

An organic high molecular weight compound used in the practice of the invention should have the property that it is not easily fluidized at normal temperature and should preferably have a molecular weight of about 400 or more. Examples of useful organic high molecular weight compounds are the following: cyclopentadiene polymers, cyclopentadiene copolymers, polystyrenes, styrene copolymer, α-methylstyrene polymer, α-methylstyrene copolymer, polyvinyl chloride, vinyl chloride copolymer, acyl amyl copolymer, vinyl copolymer estersampolymerisat, akrylsyrasampolymerisat, metakrylesterpoly- mers, metakrylestersampolymerisat, methacrylic acid copolymers, vinyl acetate polymers, vinyl acetate copolymers, such as ethylene -vinylacetatsampolymerisat, akrylnitrilsampolymerisat, acrylamide copolymers, allylalkoholsampolymerisat, bensylkloridpoly- condensation bensylkloridsampolykondensationsprodukter, meta-xylene-formaldehyde condensates, diphenyl-formaldehyde condensates, diphenyl-meta xylene-formaldehyde copolycondensation products, styrene polymers, styrene copolymer, α-methylstyrene polymer, u-methylstyrene copolymer. These high molecular weight compounds have good compatibility with different types of the organic acid substance and they can therefore be easily pulverized into fine powders and maintain a good color-forming property.

It is desirable that the above-mentioned organic high molecular weight compound be selected from compounds compatible with the organic acid substance to be incorporated therein. The term "compatibility" in the sense in which it is used herein refers to the property that two or more chemical substances dissolve in each other, as well as in the case where dissolution occurs only in one substance because the other is crystalline. In many cases the compatibility of a chemical substance can be explained in relation to the polarity of the substance.A suitable combination of the organic acid substance and the high molecular weight compound of the present invention will be determined taking into account this point of view.In general, the polarity of chemical substance is qualitative An aromatic carboxylic acid usually increases in the organophile and decreases in polarity as the number of carbon atoms increases. In the case of aromatic carboxylic acids with the same number of carbon atoms, the polarity will increase gradually. facing such polar radicals as hydroxyl, carboxyl, nitro, cyano and halogen es in the molecule. The polarity can also vary, depending on the type of radicals and the position of the radicals in the molecule. The type of polyvalent metal affects the compatibility, which can be explained in connection with the polarity. For example, many of the polyvalent metals which show a tendency to form polyvalent metal salts with a high inorganophilic or high polarity are metals with a comparatively low atomic weight, such as magnesium, aluminum, calcium and titanium. In contrast, zinc and tin show a tendency to form polyvalent metal salts with low inorganophilicity or low polarity. In the case of high molecular weight organic compounds, for example polyethylene and polypropylene, which are considered to be of the lowest polarity, are introduced with double bonds or substituted by halogen, benzene ring or hydroxyl, carboxyl, ether, ester, ketone , nitro-, cyan- and amide radicals, on the other hand, the polarity will increase, depending on the type and number of substituents.

Since substances of similar polarity are compatible or miscible with each other, a powdered homogeneous mixture comprising an organic acid substance and an organic high molecular weight compound will be obtained by selecting the organic high molecular weight compound having similar polarity as the polarity of an aromatic carboxylic acid and a polyvalent metal salt.

An organic high molecular weight compound that is compatible with an organically acidic substance of comparatively high polarity is selected from a high polarity compound having polar radicals in the molecule. However, if such radicals as -C = N, -CO-, ~ N =, -SO 2 -, -SO-, -S-, -PO =, -P =, -CS- and -O- occur in large numbers in the molecule they prevent the color formation reaction with a color former, so it is desirable to limit the introduction of such radicals to the absolute minimum possible. Halogen and a phenyl radical do not constitute 7313139-3 _...._..._ ..,. obstacles to the color reaction. In particular, hydroxyl and carboxyl radicals do not impede the color reaction, and they increase the polarity in the presence of a small number of radicals.

Although the incorporation ratio of the organic high molecular weight compound to the organic acid substance is not particularly limited, the desired resistance to heat, light and especially to a high humidity or water can not be achieved. when the amount of the high molecular weight organic compound is too small. It is desirable to include the high molecular weight organic compound in an amount of 5 parts by weight, or more, preferably 1.5 to 500 parts by weight, based on 100 parts by weight in dry weight of the organic acid substance.

There are many methods for obtaining a powdered mixture comprising the organic acid substance and the organic high molecular weight compound. The simplest and most preferably used method is to mix and melt the organic high molecular weight compound and the organic acid substance while heating, after which the product obtained is allowed to solidify by cooling and pulverized. According to another method, the organic acid substance and the high molecular weight compound are dissolved in an organic solvent therefor, after which they are mixed, then the product obtained is evaporated to dryness and later pulverized. The pulverization can be carried out in a dry system or in a wet system with a medium such as water. In this case, surfactants and fine powders with high hardness, such as silicon anhydride and kaolin, can be used simultaneously so as to increase the efficiency of the pulverization.

As the organic high molecular weight compound used in the above methods, one having a comparatively high glass transition point (second order transition point) and a comparatively low molecular weight are preferred. It is generally said that an organic high molecular weight compound with a large number of ring structures in the molecule shows a high second order transition point. Examples are polystyrene, styrene-α-methylstyrene copolymers, α-methylstyrene polymers, cyclopentadiene copolymers, aliphatic unsaturated hydrocyclic hydrocarbon polymers, benzyl chloride-diphenyl-poly-condensation products, methaxylene-formaldehyde-polycondensation-diphenylsene products formaldehyde copolycondensation products, diphenyl-formaldehyde polycondensation products, methacrylic ester polymers and acrylonitrile styrene copolymers. with a molecular weight of between about 600 and 5000.

Alternatively, a granular mixture in water-dispersed form is obtained by converting the organic acid substance and the high molecular weight compound to liquid by heating or adding an organic solvent, after which the product obtained is dispersed in water and cooled, or, if necessary, the organic solvent is removed.

According to a further alternative method, the organic acid substance and an initiator as well as a polymerization regulator are mixed with a vinyl monomer capable of dissolving the organic acid substance, such as styrene, methyl methylene, ethyl acrylate and methyl methacrylate, to provide a suspension or emulsion polymer. in water and thereby obtains a granular mixture, consisting of the organic acid substance and an organic high molecular weight compound. According to another alternative method of obtaining the granular mixture, an alkali metal or an ammonium salt of aromatic carboxylic acids is added to an emulsion of organic high molecular weight compounds, for example a polystyrene emulsion and a styrene-butadiene copolymer emulsion, whereupon an acid or a aqueous solution of polyvalent metal salts is added and an acid decomposition or double reaction is effected. In this case, heating can be used to promote the diffusion of the aromatic carboxylic acid or its polyvalent metal salt into the particles of the emulsified organic high molecular weight compound. A finely divided mixture is thus obtained in the form of an emulsion or dispersion in water.

In many cases, according to the invention, the organic acid substance and the organic high molecular weight compound are completely dissolved in each other to form a homogeneous phase, but even if parts which do not dissolve are partly present in the homogeneous phase, this does not mean anything at all. obstacles to the objects of the invention.

The fine powders obtained are controlled to a particle size of normally less than several microns, preferably about 0.5 microns.

In some of the methods for preparing the granular mixture comprising the organic acid substance and the organic high molecular weight compound, the granular mixture may also be mixed with a water-insoluble inorganic material in the form of particles such as oxides, hydroxides and carbonate of a metal, another mineral pigment and / or an organic material in the form of powder, such as powdered starch, powdered celluloses and organic pigments. For example, when incorporating the organic acid substance with the high molecular weight organic compound under heating, a water-insoluble inorganic material in the form of particles such as clay, kaolin, activated clay, zinc oxide, calcium carbonate and aluminum hydroxide is also incorporated, after which the product is solidified. by cooling and then pulverized. A granular substrate is thus obtained in which the mixture of the organic acid substance and the organic high molecular weight compound can be adsorbed around the inorganic powders. The further incorporation of the inorganic or organic powders causes an expansion of the granular substrate and an improvement of the fluidity of a coating composition. In particular, the incorporation of the inorganic powders, as will be mentioned below, improves a color-forming property of the organic acid substance as well as the resistance of a sensitized sheet to sunlight. The amount of inorganic or organic powder mixed in is not particularly limited as long as the properties of the organic acid substance do not deteriorate. It is generally preferred to mix the inorganic and / or organic powders in a quantity of less than 2000 parts (dry weight) per 100 parts (dry weight) of the organic acid substance.

In order to improve the compatibility between the organic acid substance and the organic high molecular weight compound and the color-forming property, it is preferred to additionally mix an aliphatic carboxylic acid and / or a polyvalent metal salt thereof in the granular substrate.

Examples of aliphatic carboxylic acids which may be mentioned are saturated monocarboxylic acids of the formula CnH2n + 1COH, where n is an integer, for example valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid or a petrochemical or petrocyenic acid, cyclic monocarboxylic acid represented by the formula CnH2n_mCOOH, where n is an integer and m is an integer equal to 1, 3, 5, 7 or 9, for example acrylic crotonic acid, oleic acid, elaidic acid, erucic acid, linoleic acid, elaeostearic acid, phenylacetic acid or naphthylacetic acid, ricinic acid or oxystearic acid, linolenic acid, a monooxy fatty acid such as lactic acid, Isic acid, a halogenated fatty acid such as α-dichloro-palmitic acid, d-chlorostearic acid and α, α-dichlorostearic acid, a poly fatty acid13 such as oxal- Acid, malonic acid, suceic acid, glutaric acid, adipic acid, suberic acid, azdaic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, malic acid and c citric acid and halogenated products thereof, phenoxyacetic acid, a core-substituted phenoxyacetic acid, maleic acid copolymer, an unsaturated fatty acid polymer or an unsaturated carboxylic acid copolymer and rosin.

A metal salt of the above-mentioned aliphatic carboxylic acids can also be used for the same purpose as mentioned above. Among these compounds may be mentioned salts of all metals which may form salts with the abovementioned fatty acids. The aliphatic carboxylic acids and the metal salts thereof are preferably used in an amount of less than about 100 parts (dry weight) per 100 parts (dry weight) of the organic acid substance and the high molecular weight organic compound together.

A coating composition according to the invention is obtained by dispersing the granular mixture comprising the organic acid substance and the high molecular weight organic compound, if required, with a suitable binder in water or any suitable organic solvent which does not readily dissolve the organic acid substance and the high molecular weight compound. Examples of such an organic solvent are methanol, ethanol, isopropanol, ethylene glycol and propylene glycol, which can be used in admixture with water. Examples of binders which may be mentioned are starch, casein, gelatin, gum arabic, polyvinyl alcohol, polyacrylamide, acrylamide-methylol-acrylamide copolymer, acrylamide-acrylonitrile copolymer, methylol-acrylamide-acrylate-acrylate-ester-copolymer copolymer, acrylic acid-acrylic ester copolymer, melamine resins, urea resins, sodium nolyacrylate, carboxymethylcellulose, carboxyethylellulose, natural rubber, artificial rubber, polyacrylic acid ester, polymethacrylic acid ester, polyvinyl acetate, polyethylene polyethylene, vinyl ampoule , ethylcellulose, nitroellulose, cellulose acetate, phenolic resins, butyral resins, petroleum resins and alkyd resins.

The binders, especially the water-soluble ones, can be added with chemical linkers to form water-insoluble binders by the reaction.

If an aqueous coating composition is desired, a water-insoluble binder in the form of a suspension or emulsion in water is used. A carboxyl-modified polymer emulsion is particularly preferable because it is quite stable in coatings and exhibits sufficient adhesive properties when present in small amounts. Examples of such emulsions are carboxylated styrene-butadiene copolymer emulsions, carboxylated methyl methacrylate-butadiene and vinyl acetate-crotonic acid copolymer emulsions. In many cases a mixture of two or more binders is used, and a suitable combination of water-soluble and water-insoluble binders is usually used.

The coating composition of the invention may contain water-insoluble oxides, hydroxides and carbonate of a polyvalent metal and / or other mineral pigments. In particular, such metal compounds as oxides, hydroxides and carbonates of a polyvalent metal show an excellent color-forming property as they are present at the same time as the aromatic carboxylic acids. These metal compounds can therefore be used with good effect in combination with some of the aromatic carboxylic acids which are considered to be disadvantageous in practice to the result of an inactive phase-gray reaction and low color catheter. Suitable inorganic metal compounds are oxides, hydroxides and carbonates of such metals as magnesium, calcium, barium, zinc, titanium, aluminum, nickel, cobalt, manganese, iron, tin, chromium and palladium.

Magnesium oxide, calcium oxide, barium oxide, zinc oxide, alumina, tin oxide, magnesium hydroxide, calcium hydroxide, zinc hydroxide, aluminum hydroxide, tin hydroxide, magnesium carbonate, calcium carbonate and zinc carbonate are preferably used.

The above-mentioned inorganic metal compounds, which generally belong to the class called "mineral pigments", have little color-forming ability per se, but nevertheless they exhibit the particular color-forming ability in combination with the aromatic carboxylic acids. The above-mentioned metal compounds will therefore be specifically referred to as "inorganic metal compounds" in this text and thereby to be distinguished from the conventional mineral pigments.

Examples of mineral pigments in addition to the inorganic metal compounds used are activated clay, acid clay, aluminum silicate, zinc silicate, tin silicate, a colloidal aluminum hydrosilicate zeolite, bentonite, kaolin and talc. In the description of the invention, they will simply be referred to as "mineral pigments".

The coating composition may include the above-defined inorganic metal compound and the mineral pigment in an amount of between 1 and 10,000 and preferably between 5 and 1000 parts (dry weight) per 100 parts (dry weight) of the aromatic carboxylic acid and / or the polyvalent metal salt thereof. It should be noted that the coating composition may contain all or part of the inorganic metal compound and the mineral pigment contained in the granular substrate consisting of the organic acid substance and the high molecular weight organic compound mentioned above. The desired coating compositions for some types of copy paper units also contain fine capsules; which encloses the color former therein.

The coating composition is applied to the surface of a substrate by conventional coating means, for example an air knife, rollers, wings and a sizing press, or else it is applied to the substrate by a printing press, for example a letterpress, and the flexographic method is applied. If a coating composition is of the organic solvent type, the printing method is preferred, the coating composition further comprising a plasticizer such as tributyl phosphate, dibutyl phthalate, dioctyl phthalate, butyl adipate and castor oil.

A natural fiber paper, a synthetic fiber paper and a film of synthetic polymers can be used as a backing, although natural fiber paper is generally used. If required, the substrate may be provided with a barrier coating of a natural or synthetic high molecular weight substance.

The sensitized sheet according to the invention has advantages which will be described below. Since the organic acid substance is prevented from being affected by heat, light and especially high moisture content or water by means of the organic high molecular weight compound, said substance can maintain a stable color-forming ability for a long time and completely prevent the color saturation. Thus, a comparatively low molecular weight organic acid substance, such as salicylic acid or its polyvalent metal salt, which was previously unusable for practical use, can now have practical application.

Since the coating composition has excellent mechanical and thermal stability, it can be maintained in perfect condition and the coating work can be easily performed. It is also possible to apply the coating composition to the substrate by means of a coating apparatus mounted on the paper machine, whereby the pressure-sensitive recording sheets can be obtained in a very economical manner.

The granular mixture comprising the organic acid substance and the organic high molecular weight compound can be pulverized into fine powders with a uniform particle size of several .mu.m by mechanical means, for example treatment in a ball mill. It therefore becomes possible to form a coating layer in which the fine powders are homogeneously finely divided so as to obtain clear images which are free from so-called bleeding is obtained.

. The coating composition is generally applied in a quantity of more than about 2 g / ma, and the upper limit is set for purely economic reasons.

The invention will be further illustrated by the following examples, which do not constitute a limitation. The stated quantities refer to parts dry weight unless otherwise stated.

Example 1. 100 parts of a thermoplastic modified xylene resin having a softening point of 110 ° C (which resin is sold under the name Nikanol S-100 by Mitsubishi Gas Chemistry Co., Japan) was heated to 180%, was added with 90 parts of zinc fi ß-di (cna-dimethylbenzylsalicylate with stirring and dissolved. A mass was obtained by allowing the mixture to cool and solidify. Said mass was coarsely crushed and then pulverized with 200 parts of kaolin and 50 parts of a powdered silicon anhydride (sold under the name Carplex No. 80). by Shionogi Pharmaceutical Co., Japan) in a ball mill for 15 hours.

A granular mixture with an average particle size of about 3 μm was obtained. The total contents of the ball mill were added together with 40 parts of a soluble starch and 100 parts of styrene-butadiene copolymer latex (50% dry matter) to 600 parts of water and stirred thoroughly. A coating composition was thereby obtained.

A sensitized sheet was obtained by applying the coating composition to the surface of a continuous paper web weighing 50 g / m 2 in a quantity of 10 g / mg (dry weight) using a semi-technical paper machine (sold under the name Rissar Paper Machine by Mitsubishi Kakoki). Co., Japan), which was provided with an applicator similar to a larger scale commercial applicator. The coating composition was applied to the surface of a preheated paper web and recycled during the coating operation.

As a result, the coating composition was subjected to mechanical shear and at the same time reached a temperature of at most 7000 but maintained a markedly stable fluidity without any increase in viscosity.

Examples 2-1 - 2-14 100 parts of α-methylstyrene-styrene copolymer having a molecular weight of about 1500, obtained by polymerizing 60% by weight of α-methylstyrene and 40% by weight of styrene in the presence of thioglycolic acid, were mixed and fused with 200 portions of each of the organic acid substances mentioned below at temperatures of between 15,000 and 19,000 to form a homogeneous liquid phase. An easily crushable mass was obtained by cooling the liquid phase.

Example No. Organic acid substances 2 - 1,3-di- (α-methylbenzyl) -salicylic acid 2-2 zinc 5-phenyl-5- (d, α-dimethylbenzyl) salicylate 2-3 aluminum 3-phenyl-5- (α, α-dimethylbenzyl) -salicylate 2-4 zinc-3-cyclohexyl-5- (α, α-dimethylbenzyl) -salicylate 2-5 zinc salt of 3-cyclohexyl-5- (α, α-dimethylbenzyl) -salioylic acid 70 % by weight and its aluminum salt 30% by weight 2-6 zinc 3,5-di- (α, α-dimethylbenzyl) salicylate 2-7 zinc salt of 3,5-di- (α, α-dimethylbenzyl) -salicylic acid 70% by weight and its aluminum salt 50% by weight 2-8 zinc 5- (α-methylbenzyl) -5- (α, α-dimethylbenzyl) -1-salicylate 2-9 zinc salt of 3- (α-methylbenzyl) -5- (α, d-dimethylbenzyl) - salicylic acid 70% by weight and its aluminum salt 30% by weight 2-10 zinc 3,541- (oW-methylethyl) silica-2-zinc-5- (d, α-dimethylbenzyl) -5-phenyl-salicylate 2-122 aluminum 3- (a, α-dimethylbenzyl) -5-phenyl-salicylate 2-13 zinc salt of 3- (α, α-dimethylbenzyl) -5-phenyl-salioylic acid 70% by weight and its aluminum salt 30% by weight 2-yellow zinc 3,5-dicyclohexylsalicylate 200 parts of each of the resulting masses was crushed to an average particle size of about 200 microns, mixed with a portion of a formaldehyde sodium naphthalene sulfonate condensate (sold under the name Demol-N by Kao Atlas Company, Japan) and 600 parts of water, and 20 parts of a soluble starch, after which the whole was passed through a sand-grinding mill. Finally, 40 parts of an ethylene-butadiene copolymer latex (50% dry matter) were added thereto to obtain different coating compositions.

Sensitized sheets were obtained by applying each of the coating compositions to a substrate 1 in the amount of 7 g / mg (dry weight) in the same manner as in Example 1. All coating compositions exhibited excellent mechanical and thermal stability during the coating operation. Example Q-lkskâ-lä 200 parts of each of the pulps obtained according to Example 2 were crushed to an average particle size of about 200 .mu.m and mixed with 200 parts of kaolin, 50 parts of zinc oxide, 600 parts of water, 40 parts of a soluble starch. and some Demol-N (compare Example 2), after which pulverization took place in a sand-grinding mill. Finally, 100 parts of a carboxylated styrene-butadiene copolymer latex (50% dry matter) were added thereto so as to obtain different coating compositions.

Sensitized sheets were obtained by applying each of the coating compositions to a substrate in the amount of 10 g / m 2 (dry weight) in the same manner as in Example 1. The entire coating composition exhibited the same mechanical and thermal stability as in Example 1.

Example 4.

A coating composition was obtained by the same procedure as in Example 1, except that 5 parts of zinc stearate was additionally added to the mixture of 100 parts of Nikanol S-100 and 90 parts of zinc-5,5- (d1 (d, d-dimethylbenzyl) salicylate. A sensitized sheet was obtained from the coating composition in the same manner as in Example 1.

Example §. 100 parts of α-methylstyrene polymer having a molecular weight of about 1100 were heated to about 18000 together with 10 parts of zinc stearate, and 60 parts of zinc-5 - {'4' - (d, α-dimethylbenzyl) -phenyl '- 5- (α, d-dimethylbenzyl) salicylate was melted and mixed therewith. The product obtained was cooled and solidified, after which it was coarsely crushed. All the crushed products were mixed with 40 parts of a powdered zinc silicate, 20 parts of polyacrylamide (degree of polymerization approx. 1000) and 500 parts of water and pulverized in a porcelain ball mill. for about 20 hours. Finally, 60 parts of a styrene-butadiene polymerization latex were added thereto to form a coating composition.

A sensitized sheet was obtained from the coating composition using the same procedure as in Example 1. The coating composition exhibited good mechanical and thermal stability during the coating operation.

Examples 6-1- «6-14. 100 parts of a camethylstyrene copolymer (molecular weight about 1100) were mixed and fused with 150 parts of each of the organic acid substances listed below at temperatures of 10000-20 ° C. A mass was obtained when the formed liquid was cooled and solidified.

Example No. Organic acid compounds 6-1 salicylic acid 6-2 zinc salicylate 6-3 5-hydroxy-5- (α, α-dimethylbenzyl) -salicylic acid 6-4 zinc 5-hydroxy-5- (α, α-dimethylbenzyl) -salicylate 6-5 zinc 5-phenyl-5- (α, d-dimethylbenzyl) -salicylate 6-6 zinc 5,5-di- (α-methylbenzyl) -salicylate 6-7 zinc 3, salt-tertiary-bu- .alpha.-zinc cyate 6-8 zinc β-octoxyl benzoate 6-9 zinc 5-phenyl-salicylate 6-10 4-tertiary-butylbenzoic acid 6-11 zinc 5- (5'-carboxy-4'-hydroxybenzyl) -salicylate 6- 5- (3'-Carboxy-4'-hydroxybenzyl) -salicylic acid 6-13 Magnesium 5,5-di-tertiary-butyl salicylate 6-14 1-Carboxy-2,5-dihydroxy-6- (a , α-dimethylbenzyl) -naphthalene 50% by weight and 1-carboxy-2,5-dihydroxy-7- (d, d-dimethylbenzyl) -naphthalene 50% by weight Each of the pulps was crushed into a powder having a particle size of about 200 um. 200 parts of each of the powdered substances were mixed with 50 parts of zinc oxide, 600 parts of water and 40 parts of a soluble starch and pulverized in a sand grinding mill. Finally, 100 parts of a carboxylated styrene-butadiene copolymer latex (50% dry matter) were added to form a coating composition. A sensitized sheet was obtained by applying the coating composition to a substrate in the same manner as in Example 1. Each of the coating compositions exhibited the same mechanical and thermal stability as the coating composition of Example 1.

Example 1. 100 parts of polystyrene having a molecular weight of about 1000, 50 parts of aluminum 5- (α; d-dimethylbenzyl) -5-cyclohexyl salicylate and 500 parts of kaolin were heated to 18,000, melted and mixed. Such a mass was obtained by cooling and solidifying the product formed.

The pulp was coarsely crushed and then mixed with 520 parts of an aqueous solution containing 20 parts of polyvinyl alcohol, and then pulverized in a ball mill for 20 hours. Finally, 20 parts of a styrene-butadiene copolymer latex (50% dry matter) were added to form a coating composition.

A sensitized sheet was obtained from the coating composition according to the same procedure as in Example 1. The coating composition exhibited the same mechanical and thermal stability as the coating composition of Example 1.

Example gel 8., 100 parts of d-methylstyrene polymer having a molecular weight of about 1000, 50 parts of 3-cyclohexyl-5- (d, d-dimethylbenzyl) -salicylic acid, 5 parts of stearic acid and 50 parts of zinc oxide were heated at 170 ° C, allowed to melt and mixed. The resulting product was cooled and solidified to form a mass. The resulting mass was coarsely crushed and charged with 500 parts of an aqueous solution containing 20 parts of starch, after which it was pulverized in a ball mill for 10 hours.

Finally, 50 parts of a styrene-butadiene copolymer latex (50% dry matter) were added to form a coating composition. A sensitized sheet was obtained from the coating composition by the same procedure as in Example 1. The coating composition showed the same mechanical and thermal stability as the coating composition in Example 1.

Example gel 2. g of 100 parts of polystyrene having a molecular weight of about 2000, obtained by polymerization in carbon tetrachloride, and 100 parts of aluminum 3,5-di (d-methylbenzyl) salicylate were mixed in and melted at about 15000 and then allowed to cool and solidify. . The resulting mass was crushed into grains with a particle size of less than about 1000 .mu.m and added with 400 parts of kaolin and 100 parts of zinc oxide, after which pulverization took place in a ball mill for 10 hours.

All the products treated in the mill were dispersed in a solution consisting of 200 parts of water, 800 parts of ethanol and 100 parts of ethylcellulose to form a paint composition.

A sensitized sheet was obtained by printing the ink composition on a substrate weighing 50 g / m2 in an amount of 7 g / m2 (dry weight) using the usual printing machine. Example 10. 100 parts of styrene-allyl alcohol copolymer (monomer weight ratio 90:10, molecular weight about 5000) and 200 parts of zinc-3,5- -di- (α-methylbenzyl) -salicylate were dissolved in 200 parts of acetone . The acetone was then allowed to evaporate to give a mass. This mass was coarsely crushed to a particle size of about 200 .mu.m, and 200 parts of the crushed products were mixed with 1 part of Demol-N (Compare Example 2), 600 parts of water and 20 parts of a soluble starch and pulverized in a grinder (sold). under the name Attritor by Mitsui Miike Seisakusho, Japan). Finally, 40 parts of styrene-butadiene copolymer latex (50% dry matter) were added to form a coating composition.

A sensitized sheet was obtained using the coating composition in the same manner as in Example 1.

Example ll. 100 parts of styrene-allyl alcohol copolymer (monomer weight ratio 85:15, molecular weight about 1500) and 300 parts of zinc-5,5-di- (d-methylbenzyl) salicylate were dissolved in 300 parts of acetone. The resulting solution was added in small portions to a dispersion consisting of 2500 parts of water, 50 parts of Demol-N and 500 parts of kaolin with stirring, whereby a dispersion of a granular support consisting of styrene-allyl alcohol copolymer and zinc-3,5- di- (as -methylbenzyl) -salicylate was obtained. A sensitized sheet was obtained by applying the dispersion to a substrate weighing 50 g / m 2 in an amount of 7 g / m 2 dry weight.

Example 12. c To 200 parts of a polystyrene emulsion (50% dry substance) was added 100 parts of a 30% aqueous solution of sodium 3- (α, α--dimethylbenzyl) -5-methylsalicylate, after which heating took place to a temperature of 80 ° C. ° C and small portions of 500 parts of a 40% aqueous solution of stannous chloride were added with stirring. Stirring was then continued for about 1 hour, at the same time as the temperature of the solution was maintained at 9000. The emulsified polystyrene particles thus obtained contain tin-3- (α, d-dimethylbenzyl) -5-salicylate. Then 150 parts of kaolin, 100 parts of water and 30 parts of a soluble starch were added to the emulsion as above while vigorous stirring took place, whereby a coating composition was obtained.

A sensitized sheet was obtained by the coating composition by the same procedure as in Example 1. Examples 15-1- »Ig-3. 100 parts of zinc-5,5-di (d-methylbenzyl) salicylate were mixed and fused with 50 parts of each of the high molecular weight organic compounds listed below. The resulting product was cooled and solidified, whereby a mass was obtained.

Example No. Organic High Molecular Compounds 26 15-1 Styrene-d-methylstyrene copolymer (monomer weight_ ratio 60:40, molecular weight 50000) 15-2 polystyrene (molecular weight 1500) 15-5 styrene-acrylonitrile copolymer (monomer weight ratio 80:20, molecular weight b 2000) 15-4 vinyl chloride-vinyl acetate copolymer (monomer weight ratio 85:15, molecular weight 5000) 15-5 styrene-methyl methacrylate copolymer (monomer weight ratio 80 = 20o, molecular weight eooo) 15-6 - diphenyl-formaldehyde polycondensation product 600 ) 13-7 sheilaek 15-8 polystyrene (molecular weight 1500) 70% by weight and paraoctylphenol-formaldehyde polycondensation product (molecular weight 800) 50% by weight Each of the above pulps was roughly crushed. 150 parts of each of the crushed products were mixed with 75 parts of kaolin, 55 parts of activated clay, 450 parts of water and 50 parts of a soluble starch and pulverized in a sand-grinding mill. Finally, 75 parts of a styrene-butadiene copolymer latex were added (50% dry matter) to form a coating composition. A sensitized sheet was obtained from the coating composition according to the same procedure as in Example 1. The coating composition showed good mechanical and thermal stability as in the case of Example 1. For comparison with the above examples, an aqueous dispersion of organic acid substance was prepared separately containing the composition given below.

Comparative Sample 1: Composition Weight Parts Salicylic Acid 100 Demol-N (see Example 2) 1 Polyvinyl Alcohol 5 7313139-3 27 Comparative Groove 2: Composition Weight Parts Salicylic Acid 100 Zinc Oxide 300 Demol-N 4 Polyvinyl Alcohol 20 Comparative Groove Q: Comgosition Violet Parts 100 N 1 Styrene-butadiene copolymer latex (50% dry matter) 16 Comparative coarse 4: Composition Weight parts z1nk-3,5-d1_tere1ar- butyl salicylate 100 Activated clay 300 Demol-N 4 Starch 9 Styrene-butadiene copolymer dry latex (50% dry matter) A sensitized sheet was obtained by applying each of the above dispersions to a substrate weighing 50 g / ma in a variety of between 7 and 10 g / ma (dry weight) in a single method as in Example 1.

To confirm the effects of the sensitized sheets of the invention, a topsheet coated with microcapsules enclosing a color former therein was prepared. These microcapsules can be manufactured in accordance with, for example, the. U.S. Patent No. 2,800,457. An embodiment of the preparation is set forth below. 50 parts of an acid-treated gelatin were added to 470 parts of water and dissolved at 6000. 5 parts of crystal violet-lactone were dissolved in 100 parts of isopropylnaphthalene, heated to 60 ° C and added with the aqueous gelatin solution obtained above, after which emulsification and dispersion took place under stirring to form small droplets of oil with an average particle size of between 4 and 5 .mu.m. Then 300 parts of a 10-percent aqueous solution of gum arabic were added to the above-mentioned emulsion, after which another 200 parts of water were added, after which the pH value of the dispersion was adjusted to the interval 4-4.5 by adding vinegar. 7z1z1z9-3 28 acid. The dispersion was cooled to 10 ° C to give a formed film to a gel, which was added with 10 parts of formaldehyde. After aging for 10 hours, a capsule dispersion was formed. A topsheet was obtained by applying the dispersion to a backing paper weighing 50 g / m 2 in an amount of 5 g / m 2 (dry weight). the effects of the sensitized sheets of the invention were confirmed in the following manner. A sensitized sheet that was subjected to the treatments described below resp. a sensitized sheet which was not subjected to said treatments was placed under an upper sheet provided with the encapsulated color former in such a way that the coated surface was in contact with the microcapsules, after which a marking print was applied by means of a typewriter. Stability in the color-forming ability with respect to heat, light and moisture was observed by differences in the density of a developed color image between the treated and untreated sheets. E E a) A sensitized sheet was allowed to stand in an environment with 90% relative humidity and the temperature 5o ° c for io hours. b) A sensitized sheet was allowed to stand in an environment at 100 ° C for 5 hours. c) A sensitized sheet was exposed to direct sunlight for 3 hours, and in addition to the above tests, a sensitized sheet was brought into close contact with an upper sheet so that the coated surface and the microcapsules were opposite each other. After immersion in water, the sheet batch was allowed to dry, after which the individual sheets were separated. In the case of a sensitized sheet, the resistance to water is low, so the coated surface of the topsheet assumed a color and was exposed to "paint soiling".

The results of the above tests are shown in Table 1.

To confirm the stability of a developed color image with respect to light, heat, moisture and water, the following experiments were performed.

The topsheet was placed over the sensitized sheet in such a way that the coated surface and the microcapsules were opposite each other, after which a marking print was applied by means of a typewriter. After standing for 24 hours, the sensitized sheet was subjected to the treatments set forth below, resulting in a reduction in the density of the color image. .a) A sensitized sheet was placed in an environment with 90% relative humidity and a temperature of 50 ° C for 10 hours. b) A sensitized sheet was placed in an environment with a temperature of 100 ° C for 5 swims. 7313139-3 29 c) A sensitized sheet was directly exposed to the sun for 5 hours. d) A sensitized sheet was dipped in water and allowed to dry at normal temperature.

The results of the experiments performed above can be found in Table l. M m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m. mmmmmmm »m mm mmmmmmm m- mmmmmmmmm m- mmm m_ mmmmm m- mmmmmmmmm mouth mmmmmmmmm mm- mmmmmmmmm mm» mmmmmmmmm mm- mmmmmmmmm S- ommmmmmmmm om- 3 mmmmmmmmm m- mmmmmmmmm _ m- mmm .mm mmmmm. m- mmmmmmmmm m- mmmmmmmmm now mmmmmmmmm m- vw ommmmmmmm mm mf mmmmm _ m. m. m m m 1% mø »mm> _ mdwm wëmm>. »Wnm fl nxøm mmuum> mäm msnm> pmmmmuxßw Ål _ u. OE u ~ OE u. OE n. OE u CE # 05 u. OE u. OE m5 mwmmmm møcmmmmoz mqmmmmcm mcmmwpoz .ummmmmos mqmmwmoz unmmwmomm mmmmommoz ä. mon pwuw. . . m Hmm ïuàwnwmmmmmmm mmmmmmmmmm wmmmmmäömm m2. mom ... wmmmmmmmm šmmammmmwømåmmmmmmm mom mwmm fi mmmm »ewwm A ... m m. Anm www mm .mmmGmnmHsmmmw> mumson mwmv .m H fl mnm fi> ... 1 31 å gt \ 44:11:14 mm 4 4 m <= m <mmmmm 4 4 4 4 44444 444m mmmmm mmmm mmmmm mmm4 44444 4 4 4 4 44444_ 4444 44444 mmmm mmmmm mmmm 44444 4 4 4 4 44444 4m4m 44CQFD4 4 4 4 4 44444 4131144 44444 4 4 4 4 44444 4444 44444 mm 4 4 m4m4m mmmm O fi Nt fi- fi 'O (UM-d- f-la- »Lf-If-ll-I - | rn ko co - ~ l.-1 - | - | fa IfM-lll ||||||| -l ||| O-IN xo | mar-If: í 7z13139 ~ 3 '% 52 .. \ = tm <fi mmm fl ít << f fl <fl <fl r fl mr fl <<<<< 1 <fi mmm <<n <4 fifl lm fl l fs' 3 f-INM-: i-Lnwß-oo nf-icur fl: Annsuuun 42: å 7313139-3 33 In the previous tables, the letters have the following meanings: Stability of the color-forming ability A : the original color formation ability was maintained B: barely affected C: strongly affected D: completely gone (color images could not be produced) Stability of the developed color image A: no color change at all B: slightly bleached C: heavily bleached D: bleached or discolored Image color intensity A: strong B: average C: extremely weak

Claims (12)

7313139-3 54 PATENT REQUIREMENTS Sheet-shaped material intended for use in a pressure-sensitive copying system and sensitized with a coating for producing color on contact with a chromogenic material, characterized in that said coating contains a granular mixture comprising (a) 100 parts by weight of an acidic organic substance selected from the group consisting of aromatic carboxylic acids and polyvalent metal salts thereof, and (b) from 5 to 300 parts by weight of an organic high molecular weight compound selected from the group consisting of polystyrene, styrene copolymer, ohmethylstyrene polymers, dimethylstyrene copolymer, polyvinyl , vinyl chloride copolymer, vinymide chloride copolymer, polychloroprene, cyclopentadiene polymers, cyclopentadiene copolymer, acrylic ester polymers; akrvlestersampolymerisat, akrylsyrasam- polymer, metakrylesterpolymerer, metakrylestersampolymerisat, methacrylic acid copolymers, vinyl acetate polymers, vinyl acetate copolymers, such as ethylene-vinyl acetate copolymer, acrylic nitrilsampolymerisat, akrylamidsampolymerisat, allylalkoholsam- copolymers, polycondensation products benzyl chloride, benzyl-sampolykondensationsprodukter, meta-xylene-formaldehyde condensate , diphenylformaldehyde condensate and diphenyl-meta-xylene--formaldehyde copolycondensation products, said organic high molecular weight compound having a molecular weight of at least 400, being non-flowing at ordinary temperature and being compatible with said acidic organic substance. A sheet material according to claim 1, characterized in that the acidic organic substance has at least one 5- or 6-carbon ring as a substituent and has 17 or more carbon atoms in its chemical structure. A sheet material according to claim 1, characterized in that the acidic organic substance has a hydroxyl group in the ortho position to the carboxyl group of the aromatic ring. A sheet material according to claim 1, characterized in that a quantity of the organic high molecular weight compound is in the range from 15 to 500 parts by weight based on 100 parts by weight of the acidic organic substance. I _35 7313139-3 Sheet-shaped material according to claim 1, characterized in that said coating further contains at least one water-insoluble inorganic material in the form of particles consisting of inorganic metal compounds or mineral pigments. Sheet-shaped material according to claim 5, characterized in that a quantity of said inorganic material is in the range 1 - 10,000 parts by weight based on 10 10 parts by weight of the acidic organic substance. Sheet-shaped material according to claim 5, characterized in that the inorganic material is partially or completely incorporated with the granular mixture, which consists of the acidic organic substance and the high-molecular compound. A sheet material according to claim 5, characterized in that the inorganic material is incorporated with the granular mixture in a weight ratio of at most 2000 parts based on 100 parts of the acidic organic substance. Sheet material according to claim 5, characterized in that the inorganic metal compounds consist of one or more oxides, hydroxides and / or carbonate of any of the metals zinc, aluminum, calcium, magnesium, titanium, nickel, cobalt , manganese, tin, chromium and vanadium. Sheet-shaped material according to claim 5, characterized in that the mineral pigments consist of activated clay, acid clay, kaolin, talc, bentonite, aluminum silicate, zinc silicate, barium sulphate or silica gel. 11. ll. Sheet-shaped material according to Claim 1, characterized in that an organic powdery material is incorporated with the granular mixture consisting of the acidic organic substance or the high molecular weight compound. A sheet material according to claim 1, characterized in that at least one aliphatic carboxylic acid or a polyvalent metal salt thereof is incorporated into the granular mixture consisting of the acidic organic substance and the high molecular weight compound. _ ANFÖROA PUBLIKATIoNEÉn Sver1ge 379 502 (B41M S / 12) Tysktand 2 152 765