DE1961921B2 - PRINT SENSITIVE COPY PAPER - Google Patents

Description

The invention relates to pressure sensitive copier paper. A pressure sensitive copy paper is a material in which the principle is applied that an electron donating, color-reactive, colorless, organic substance (hereinafter referred to as color former) usually with an electron-accepting one Substance in a medium of a non-polar oily solvent reacts to to take on a color.

Leucomethylene blue, crystal violet lactone, rhodamine-B-lactone and acidic are suitable as color formers Rhodamine-B-sultone etc. and as an electron receptive substance z. B. Acid clay, active earth, Attapulgite, aluminum sulfate, natural zeolite, kaolin, bentonite, silicon dioxide gel, feldspar, pyrophyllite, Halloysite, magnesium trisilicate, zinc sulfate, zinc sulfide, calcium fluoride and organic acids or their Salts such as calcium citrate, tannic acid, benzoic acid, etc.

The pressure-sensitive copier paper generally comprises a combination of a sheet of paper, «Let the surface have a coating of the above Has color former in a non-polar solvent such as benzene, toluene, trichlorodiphenyl Od. The like. Is dissolved and then transferred into microcapsules, and a sheet of paper, the surface of which is coated with the electron-absorbing substance together with a binder. In certain Cases can be a sheet, one surface of which is coated with the microcapsules and the other side of which is coated carries a coating of the electron receptive substance between the above two Scroll to be applied. Occasionally there may also be a sheet containing the microcapsules and the electron receptive Substance is coated on the same surface. Find application. In either case the microcapsules and the ones contained in them are torn by the pressure when writing or printing Color former solution is brought into contact with an electron-accepting substance to give a colored copy image. The principle, formation and manufacture of such a material, as described above, are known (see U.S. Patents 2,548,366, 2,711,375, 2 730 256. 2 812 507, 2 800 457 and 2 800 458).

The aforesaid pressure-sensitive copying paper is required to be preserved for a long time in some uses will. However, the usual color former does not satisfactorily meet the necessary requirements done because the color former only has poor weather resistance properties and is limited in terms of shade.

The object of the invention is to provide a pressure-sensitive copying paper which does not have the aforementioned disadvantages of the known materials and is distinguished by particular durability, stability and good color tint in use.

The pressure-sensitive copier paper according to the invention is characterized in that it uses a compound of the general formula as a colorant

COOH

contains, in the ;; is an integer from 1 to 4, R ₁ and R ₂ each represent an alkyl group having 1 to 4 carbon atoms or a phenyl group, and R _{3 is} a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkoxycarbonyl group (where the Alkyl has 1 to 4 carbon atoms) or represents a halogen atom.

It is sufficient if the above-mentioned compounds in a solvent such as benzene, toluene,

ao dioctyphthalate, chlorodiphenyl or the like, dissolved and then be applied in the form of microcapsules as a coating on the surface of the paper. In use the product can be combined with the sheet, which is electron receptive with the above-described Substance is coated. Optionally, the microcapsules, which one Contain solution of the above-mentioned compound, and the electron receptive substance be applied simultaneously as a coating on the paper surface.

The microcapsules from the color former solution can be prepared according to the US Pat. No. 2,800,457 and British Patents 1,091,076, 1,091,077 and 1091078 will.

The invention also includes the new compound according to the above formula.

The compounds represented by the above formula can generally be according to the following Procedure are obtained:

R ₃ C ₆ H ₄ NH · NH ₂ and R ₁ R ₂ CHCOCH ₃

are reacted in the absence of a solvent to produce a phenylhydrazone derivative. The phenylhydrazone derivative is then refluxed _{in ethyl alcohol in the presence of ZnCl 2} in order to obtain the corresponding indolenine derivative. The indolenine derivative and Br (CH ₂ ) WCOOH are then reacted in the absence of solvent or using a suitable solvent at 100 to 150 ° C to form the quaternary salt. The thus obtained quaternary salt and n-formyl-β-naphthol can be combined with triethylamine added in the calculated amount in absolute ethanol to form a compound represented by the above formula. to be refluxed. The reactions under consideration can be represented by the following equations:

NHNM ₁ ⁺ CHjCOCH

NHN>

Γ / ^Rl

'C-

CH

i 961 92!

NH N = C-CH, ZnCl R2

Br (CH ₂ J _n COOH CH ₃ CH ₃

(CH ₂ J ₁₁ COOH

CHO

The pressure-sensitive copying paper according to the invention is excellent in durability or the preservation before and after use, because the connection according to the above general formd an excellent solubility and stability therefore leads to a material with better weather resistance properties in comparison with the usual pressure-sensitive copier paper. Also is the above connection excellent in terms of color tone.

example 1

In 50 ml of ethanol, 6.2 g of 1 - ^ - carboxyethyl-2,3,3-trimethyIindoleniumbromid and 3.4 g * -formyl /? - naphthol and after the addition of 2 g triethyl amine 2 hours under reflux at about Cooked at 78 ° C. After the reaction, the ethanol was distilled off, white crystals being obtained which were then recrystallized from ethanol, with 3.6 g of l - /? - carboxyethyl-3,3-dimethylspiro- (indoIin-2,2'-2'H -0-naph-Ihopyran) were obtained in the form of white crystals. The melting point of this compound was 203 to 208 ^° C. A solution of the aforementioned compound in ethanol was encapsulated in microcapsules according to the process described in US Pat. No. 2,800,457. The formed microcapsules were coated on paper and combined with a sheet of paper coated with an acid clay and a binder. The material was written on with a typewriter, the pressurized areas immediately colored red.

Example 2

To 100 g of a 10% aqueous solution of methyl cellulose, 10 g of a 1 ″ solution were added compound obtained according to Example 1 in chlorinated diphenyl was added and the mixture became lively stirred to form an emulsion. The emulsion was then coated onto a paper surface and dried. The thickness of the coating layer was about 100 μ. When the color-forming paper is on

(CH.KN. (CH ₂ ).

COOH

a clay-coated paper made similarly to Example 1 was superimposed and was subjected to writing pressure, the pressurized areas were colored red immediately.

Example 3

In the same way as described in Example 1, 3.3 g of l - /? - carboxyethyl-2,3,3, 5-tetramethylindoIeniumbromid and 1.7 g »-formyl- / 3-naphthol converted to 2.0 g of l- / 3-carboxyethyl-3,3,5-trimethylspiro- (indoline-2,2'-TH- / I-naphthopyran) in the form of white crystals. The melting point of this compound was 196 to 197 C. Wenn Stroke pressure was applied after applying this compound as described in Example 2, were the Pressurized spots colored red.

Example 4

45 In the same way as described in Example 1, 3.5 g of l - /? - carboxyethyl-2,3,3-trimethyl-5-chloroindolenium br <jmid and 1.7 g * -Formyl- / J- naphthol implemented, with 1.3 g of l- / 9-carboxyethyl-3,3-di-

Thus methyl - 5 - chloro - spiro - (indoline - 2,2 '- 2Ή - β naphthopyran) were obtained in the form of white crystals. The melting point of this compound was 206-208 ° C. A solution of this compound in chlorinated diphenyl was coated onto a surface of paper, which was then placed over the surface of clay-coated paper and pressurized. The pressurized areas were immediately colored red.

Example

The compound obtained according to Example 4 was in Microcapsules encapsulated by the method of Japanese Patent 493,064. The microcapsules were coated onto paper 6j and dried. The color-forming paper thus obtained was applied to a clay-coated paper launched and pressurized. The pressurized areas were immediately colored red.

Claims (3)

Patent claims: I. Pressure-sensitive copier paper with a (Jbcr / ugsschiclit of microcapsules containing a compound which is suitable for IirhhiUkmg with an ek-ktronenaufnahnuifähigen material, ύ adurc Ii geke η η ζ eic Ii η et, because the compound has the general formula liufwcist. in which η is an integer from 1 to 4, R, and R ₁ . each represents an alkyl group having 1 to 4 carbon atoms or a phenyl group and R _{3 represents} a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group (the alkyl having 1 to 4 carbon atoms), an alkoxycarbonyl group (the alkyl having 1 to 4 carbon atoms) has) or represents a halogen metal. 2. Pressure-sensitive copier paper according to claim 1, characterized in that the connection from l- / i-carboxyethyl-3,3-dimethy] -spiro- (indoline-2,2'-2'll- / i-naphthopyran), l- / i-carboxyüthyl-3,3,5-trimethylspiro- (indoline-2,2'-2'H - /? - napiiihopyran) or l- / J ~ carboxyethyl-3,3-dimethyl-5-chlorospiro- (indoline-2,2'-2'H- / i-naphthopyran) consists. 3. Pressure-sensitive copier paper according to claim 1 or 2, characterized in that the electron-absorbing material made of acid clay, active clay or active earth, attapulgite, zeolite, Kaolin, bentonite, silicon dioxide gel, aluminum sulfate, feldspar, pyrophyllite, halioysite, magnesium trisilicate, Zinc sulphate, ciric sulphide, calcium fluoride, Calcium citrate, tannic acid or benzoic acid.