DE2153635A1 - Pressure sensitive recording papers - Google Patents

Description

PATENTANWXITE DR. E. WIEGAND DIPL-ING. W. NIEMANN DR.M. KÖHLER DIPL-ING. C. GERNHARDT 2153635 MÖNCHEN HAMBURG TELEPHONE: 55 54 76 8000 MDNCHEN 15, TELEGRAMMER CARPATENT NUSSBAUMSTRASSE 10

V 40791/71 - Ko / Kl October 27, 1971

Fuji Photo Film Co., Ltd. Ashigara-Kamigun, Kanagawa, Japan

Pressure sensitive recording papers

The invention is concerned with pressure sensitive recording papers. In particular, the invention relates pressure-sensitive recording papers in which a terphenyl derivative is used as the solvent for the color former, for example hexahydroterphenyl or dodecahydroterphenyl is used.

The object of the invention is to achieve a pressure-sensitive recording paper which does not have any has an unpleasant odor or toxicity and forms a color developed image with a high density is suitable without the formation of color-developed fog. Pressure-sensitive recording papers are widely used Scope instead of carbon, copier papers or carbon copier papers of the pigment type and are used as Non-carbon copy papers or carbon-free copy paper. Different embodiments for

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Pressure sensitive copier papers are described in, for example, U.S. patents 2,712,507, 2,730,456, 2,730,457, 3,418,250 and 3,432,327.

Usually the pressure-sensitive recording papers are made from those made from a so-called top paper, which by dissolving an almost color-free Compound, hereinafter referred to as color former, in an organic solvent, encapsulation the same made in microscopic capsules, then pulling the capsules onto the carrier one by drawing up a color developing material

"rials, hereinafter referred to as color developer and which is suitable for forming a colored product, sub-sheet produced on a further carrier and in some cases from a middle paper, which is produced by opening capsules containing the color former, on one side of a carrier and a color developer on the other side thereof, or containing these capsules and the color developer on the same side of the carrier.

In the case of the combination of top paper and bottom paper or top paper, middle paper and bottom paper, the color develops by local pressing in such a way that

) that the capsule layer is in contact with the color developer layer comes, whereby the capsules located on the pressed part are decomposed and a reaction between the color former and the color developer. If a pressure-sensitive recording paper that If the capsules and the color developer on the same surface are used, the color will through Pressing developed in the same way. As the color developer, active clay materials such as

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sour clay, active clay, zeolite and bentonite or organic acidic materials such as succinic acid, tannic acid, Bile acid, pentachlorophenol, and phenolic resins are used. As a color former for pressure-sensitive recording papers are for example malachite green lactone, benzoylleucomethylene blue, crystal violet lactone, rhodamine B-lactam, ^ -Dialkylamino-T-dialkylaminofluorane, 3-dialkylamino-7-alkylfluorane, 3-methyl-2,2'-spirobi- (benzo [f] chromene) and the like are used.

The conditions for a solvent to dissolve the color former for pressure-sensitive recording papers, which must be fulfilled are the following:

(a) Sufficient solubility to dissolve the necessary amount of the color former,

(b) no changes such as decomposition of the color former, color formation and the like,

(c) quite high boiling point so that none. Evaporation with an ¥ drying process and in places with increased temperature occurs,

(d) no elution upon encapsulation,

(e) no desensitization or prevention of color formation on the lower paper,

(f) low viscosity so that the capsules can flow freely when the capsules are broken, and furthermore only a small increase in viscosity even at low temperature,

(g) no unpleasant odor,

(h) low toxicity to humans and animals and the like.

Of these, conditions (a) to (e) are particularly important and if one of these conditions is not met the solvent cannot be used as a solvent for

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the color former can be used.

In fact, no solvents have yet been found which satisfy conditions (a) to (h) fulfill. Therefore those currently used are. where different types of solvents in one appropriate ratio are mixed.

Here ethers do not meet conditions (a) and (c) and alcohols do not meet conditions (a), (d) and (e), while paraffins do not meet conditions (a), Ketones, esters, olefins and amines do not meet the condition (s) and organic acids do not meet the condition

(b) fail to meet. The chlorinated diphenyl now used as a solvent for pressure-sensitive recording papers almost satisfies conditions (a) to (e). However, it has a defect that when the degree of chlorination is low, it has a particularly unpleasant odor and has a low viscosity, and that when the degree of chlorination is high, it has a high viscosity but does not exhibit such an unpleasant odor. That is, the viscosities of low chlorinated trichlorodiphenyl and tetrachlorodiphenyl are relatively low. The viscosities of trichlorodiphenyl and Tetrachlordiphenyl be JE) weils 60 cp and 200 cp at 3O ⁰ C. However, they have a particularly unpleasant odor.

The highly chlorinated pentachlorodiphenyl and hexachlorodiphenyl have considerably reduced unpleasant odor, but on the other hand their viscosity is considerably increased. The viscosity of pentachlorodiphenyl is 2000 cp at 30 ^° C. Hexachlorodiphenyl has no flowability at room temperature. Therefore, trichlorodiphenyl and tetrachlorodiphenyl are used as solvents for pressure-sensitive

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sensitive recording papers are used. However, solvents that do not show the above defects will become still needed.

Since the chlorinated diphenyls are somewhat decomposed by light and form hydrogen chloride, they show with Capsules coated arches when using chlorinated biphenyl have the fault that they are exposed to light generate hydrogen chloride for a long time and this with the color former to form a colored Fog reacts. Furthermore, the colored mist causes a decrease in color development suitability the lower paper and a sufficient density of the formed color cannot be obtained. Also own the chlorinated diphenyls are noticeably toxic to humans and animals.

In the course of numerous studies with this type of solvent, it has now been established within the scope of the invention that that terphenyl derivatives such as hexahydroterphenyl or decahydroterphenyl are completely adequate for the present purposes have what forms the basis of the invention. The invention is characterized in that that in pressure-sensitive recording papers a terphenyl derivative as a solvent for the color former used separately or in combination with other solvents.

The terphenyl derivatives according to the invention can be those represented by Structures 1-4 below Contain compounds or mixtures thereof.

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If the terphenyl is used as a mixture as a solvent, the mixing ratios are not limited.

The terphenyl solvent can be mixed with other solvents. In this case the The amount of the terphenyl as a solvent is preferably more than that of the other solvent. As examples for other solvents are petroleum fractions such as kerosene, naphtha, or paraffin oil, synthetic oils such as chlorinated Paraffin, methylenebi sphenyl, alkylnaphthaliii or alkylated polyphenyl or vegetable oils such as cotton oil or flaxseed oil listed.

The above, using the terphenyl as a solvent Miscible solvents are used to adjust the viscosity, to control the solubility of the color former or used to lower the cost of manufacturing the product.

When the pressure-sensitive recording papers according to the invention are pressed, that becomes in the solvent dissolved color formers released from the broken microcapsules and effective on or in the Transferred or impregnated color developer for the formation of high density color images.

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The terphenyl derivatives can by customary methods and their physical properties are known. For example, cyclohexyl chloride, Dicyclohexyl chloride and cyclohexyl chloride with biphenyl, benzene and cyclohexylbenzene according to Friedel, Crafts implementation implemented. They can also be made by hydrogenating terphenyl.

Such compounds are commercially available from various chemical companies. For example, a mixture from Hexahydroterphenyl and Dodecahydroterphenyl under the name "Santosam 66" by Mitubishi-Monsant Co., Ltd. sold.

The terphenyl derivatives according to the invention satisfy the above for a solvent for the color former Conditions (a) to (e) required for pressure-sensitive recording papers. Furthermore, they show the excellent advantage that they show only a slight increase in viscosity even at low temperatures, they have no unpleasant odor and no toxicity for humans or animals, that the stability of the capsule-coated arc for light is increased even with exposure of the capsule-coated When compared to the arc of light for a long period of time, the colored fog of the arc is remarkably lower among the usual is that the color development suitability in developing the capsule-coated Sheet on the backing paper does not decrease, as with the usual, and the like. The pressure-sensitive recording papers according to the invention are also excellent in that they have a higher density of formed Color compared to the usual printing-sensitive recording papers, which are chlorinated

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Diphenyl is used, show.

The invention is characterized in that the terphenyl derivatives are used as solvents for the color former of pressure-sensitive recording papers can be used, and all known methods can be used as the manufacturing method can be used to encapsulate this solvent. The invention is in terms of the method or process of encapsulation is not limited. For example, as a method of microencapsulation the coacervation process (U.S. Patents 2,800,457 and 2,800,458), the surface polymerization process (British patent specification 990 443 and U.S. Patent 3,287,154), the separation process (U.S. Patent 3,418,250), and others will.

Examples of color formers which are suitable in practice are compounds of the triaryl methane type, compounds diphenylmethane type compounds, xanthene type compounds, thiazine type compounds and compounds mentioned of the spiropyran type.

The compounds of the triaryl methane type include 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, i.e., crystal violet lactone, 3,3-bis- (p-dimethylaminophenyl ) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylindol-3-yl) -phthalide, 3- (p-dimethylaminophenyl) 3- (2-methyl-indol-3-yl) -phthalide, 3- (p-dimethyl-aminophenyl) -3- (2-phenylindol-3-yl) -phthalide, 3,3-bis- (1,2-dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis-. (1 ^ -dimethylaminoindol - ^ - yl) -6-dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -5-dimethylaminophthalide, 3,3-bis- (2-phenylindol-3-yl) -5-dimethyl-aminophthalide, 3-p-Dimethylaminophenyl-3- (1-methylpyrrol-2-yl) -6-dimethylaminophthalide etc.

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The compounds of the diphenylmethane type include 4,4-bis-dimethyl-aminobenzhydrinbenzyl ether, N-halophenylleucoauramine, N-2,4,5-trichlorophenylleucoauramine and the like.

Xanthene-type compounds include rhodamine-B-anilinolactam, Rhodamine- (p-nitroanilino) -lactam, Rhodamine-B- (p-chloroanilino) -lactam, 7-dimethylamino-2-methoxyfluorane, 7-diethylamino-2-methoxyfluorane, 7-diethylamino-

3-chloro-2-methylfluorane, 7-diethylamino-3- (acetylmethylamino) fluorane, 7-diethylamino-3- (dibenzylamino) -fluorane, 7-diethylamino-3- (methylbenzylamino) -fluorane, 7-diethylamino-3-chloroethylmethylamino) -fluorane, 7-diethylamino-34iiäthylamino) fluorane and the same.

Thiazine-type compounds include benzoylleucomethylene blue, p-Nitrobenzylleucomethylene blue and similar compounds.

Spirotype compounds include 3-methylspiro-dinaphthospyran, 3-ethyl-spiro-dinaphthospyran, 3,3'-dichloro-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho- (3-methoxy-benzo) -spiropyran, 3-propyl-spiro-dibenzodipyran and the like.

Examples of color developers are active clay substances such as acid clay, active clay, attapulgite, bentonite or zeolite, organic acidic substances such as phenolic resins and the like materials.

The following examples serve to further illustrate the invention. All parts are based on weight based.

In the examples according to the invention, a clay-coated paper (backing paper) was used, which on the following method was manufactured:

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100 parts of an acid treated with sulfuric acid Tones were made in 280 parts of water, the 6 parts of a 40 S ^ - aqueous sodium hydroxide solution was dispersed using a homogenizer. Then 50 Parts of a 10 5 ^ aqueous solution of the sodium salt. of casein and 30 parts of a styrene-butadiene latex (designation Dow Latex 626 from Dow Chemical Co.) as a binder added and on a paper with a weight of 50 g / m 2 with the Luftauf spreading method to a solid content of 10 g / m, drawn up and dried and the clay-coated paper obtained.

example 1

In 50 parts of a terphenyl derivative containing hexahydroterphenyl and dodecahydroterphenyl as main components, (name Santosam 66 from Mitubishi-Monsant Co., Ltd., pour point: -27 ⁰ C, ignition point: 173 ° C _f boiling point: 340 to 40O ³ C, specific weight (25 ⁰ C): 1.005, viscosity (30 ³ C): 26.5 cp) were dissolved 1.5 parts of crystal violet lactone. The resulting solution was added to 10 parts of gum arabic, dissolved in 60 parts of warm water, ^{heated to 40 °} C. and then emulsified by means of an ultrasonic emulsifier to form an O / W emulsion with a particle size of 6 to 10 microns.

Then 10 parts of acid-treated gelatin with an isoelectric point of 7.8 were dissolved in 80 parts of water at 40 ³ C. The solution was added to the O / W emulsion and a 50% acetic acid solution was added thereto to adjust the pH to 4.2. To the system were 250 parts V / ater added of 40 ⁰ C for coacervation to form a wall film of gelatin and gum

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arabic was formed around the oil droplets in which the color former was dissolved. To gel the wall film, the system was ^{cooled to 10 3} C and then 4 parts of 37% formalin were added to harden the wall. To accelerate the Härtungseffektes 40 parts of a 10% aqueous solution of carboxymethyl cellulose were added to this and a 10% aqueous sodium hydroxide dropwise to adjust the system to pH 9.5 were added, was heated and the system to 5O ⁰ C. To the capsule liquid obtained, 15 parts of cellulose flakes were added and the microcapsule coating was obtained.

The microcapsule coating was applied to a paper weighing 40 g / m 2 to a solid content of 6.0 g / m pulled up and dried and the top sheet obtain. The microcapsule mass was based on that in the above Clay-coated paper produced in this way is mounted and dried, and the central sheet is obtained.

The upper arch, the middle arch and the lower arch were stacked so that the capsule layer y and the clay-coated layer touched each other and then printed with a needle, immediately a blue Image was obtained. When the microcapsules were broken, there was no offensive odor.

Further, the top sheet was exposed to the sunlight over a long period of time or heated at 100 ⁰ C during a long period, whereby there is no fog on the capsule-coated sheet, and no reduction in color-developing ability was caused, so that the sheets far better than the conventional pressure-sensitive recording papers under Application of

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usual solvents.

Example 2

In 50 parts Hexahydroterphenyl, which had been prepared by the reaction of cyclohexyl chloride with diphenyl in the presence of aluminum chloride, and a mixture of isomers was (boiling point 335-397 ⁰ C, specific gravity (25 ⁰ C): 1,002, viscosity (3O ³ C ): 29.1 cp) 2 parts of 3-diethylamino-7-methylfluorane were dissolved. The obtained solution was processed into microcapsules in the same manner as in Example 1.

The top sheet and the middle sheet thus obtained formed a red color image with no odor. The red picture had high density and strong lightfastness.

Example 3

The same procedure as in Example 2 was repeated, except that 2 parts of rhodamine-B-anilinolactam were dissolved in 50 parts of dodecahydroterphenyl, which had been prepared by reacting dicyclohexyl chloride and benzene in the presence of aluminum chloride and was a mixture of the isomers. The Terphenylgemisch had a boiling point of 330-390 ⁰ C, a specific gravity of 0.987 at 25 ¹ C and a viscosity of 26.7 cp at 30 $.

The top paper or middle sheet obtained formed a red color image immediately on the clay-coated one Paper. The pressure-sensitive recording paper

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was in terms of fog and lightfastness excellent.

Example 4

3 parts of Y-diethylamino ^ -diäthylamino-fluoran were in a mixture of 10 parts of chlorinated diphenyl with a degree of chlorination of 40 percent by weight and 14 carbon atoms and 40 parts of Santosam 66 dissolved. The same procedure as in Example 1 was followed and a pressure-sensitive recording paper which, when contacted with a clay-coated Paper formed a green image.

Example 5

The same procedure as in Example 1 was used, but 3 parts of T-diethylamino-S-methylamino-fluoran dissolved in a mixture of 10 parts of η-paraffin and 40 parts of Santosam 66.

The pressure-sensitive recording paper thus obtained formed a blue-black image of high density and strong lightfastness.

Example 6

In a mixture of 10 parts of diisopropyldiphenyl and 40 parts of Santosam 66, 3 parts of crystal violet lactone were obtained and 2 parts of benzoylleucomethylene blue dissolved. A solution of 10 parts of tolylene diisocyanate, 6 parts of bisphenol A, 0.5 part of lead octylate

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and 20 parts of methylene blue are mixed in and a first solution is obtained.

10 parts of gum arabic were dissolved in 50 parts of water of 3CPG , and then the first solution was dispersed in this solution by means of a homogenizer to form an * O / W emulsion with a particle diameter of 10 to 15 microns. The emulsion was added to 100 parts of water at 50 ³ C and the system was ^{heated to 80 0} C with stirring and then held at this temperature for 30 minutes to form the microcapsule liquid.

The microcapsule coating liquid was drawn up on a clay-coated paper with the air spreading method to a solid content of 4.0 g / m 2 and dried. The obtained pressure-sensitive recording paper formed a blue image when pressed with a pen.

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Claims (4)

Claims nj Pressure-sensitive recording paper, consisting of a color developer and a color former suitable for the formation of a distinctive color when coming into contact with the color developer, the color developer and the color former being mounted on the same or different carriers, characterized in that as a solvent for the color former at least one terphenyl derivative is used. 2. Pressure-sensitive recording paper according to claim 1, characterized in that the terphenyl derivative consists of hexahydroterphenyl or dodecahydroterphenyl. 3. Pressure-sensitive recording paper according to claim 1 or 2, characterized in that the terphenyl derivative is used as a mixture with a solvent other than the terphenyl derivative. 4. Pressure-sensitive recording paper according to claim 1 to 3t, characterized in that color formers and solvents are contained in microcapsules. 209819/0978