DE2049279A1 - Pressure sensitive copier paper - Google Patents

Description

PATENT LAWYERS DR. E. WIEGAND DIPL.-ING. W. NIEMANN 2049279

DR. M. KÖHLER DIPL-ING. C. GERNHARDT

MÖNCHEN HAMBURG

S ₅₅₄₇₄ 8000 monks 15, ⁷ 'October 197o

TELEGRAMS: KARPATENT NUSSBAUMSTRASSE 10

W. 4o 132/70

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

Pressure sensitive copier paper

The invention relates to a pressure-sensitive copier paper »

In general, pressure-sensitive copying paper is based on the principle that a Electron donating and color-reactive, colorless organic substance to react with an electron accepting one Substance in a medium composed of a non-polar oil solvent is brought to the formation of a color, v / o at the electron donating and color-reactive, essentially colorless organic substance (hereinafter referred to as "color former" leucomethylene blue, crystal violet lactone, rhodamine-B-lactam and acidic rhodamine-B-sultone or the like. and the electron accepting substance

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acid clay, active hone, attapulgite, aluminum sulfate, natural Zeolite, kaolin, bentonite, silicon dioxide gel, feldspar, pyrophyllite, halloysite, magnesium trisilicate, Zinc sulfate, zinc sulfide, calcium fluoride, lead sulfate, lead sulfide and an organic acid such as calcium citrate, Includes tannic acid and benzoic acid.

In general, a pressure-sensitive copier paper comprises a combination of a sheet which is to be

ψ the color formers indicated above, dissolved in a non-polar solvent such as benzene, toluene, trichlorodiphenyl or the like., has enclosed microcapsules as a coating on a paper and from a sheet which has the electron accepting substance together with a binder as a coating on a paper , and in some cases a sheet containing the microcapsules as a coating on one side and bearing the electron accepting substance on the other side is used between the above two sheets, or a sheet containing the microcapsules and the electrons .absorbent substance at the same time on the same surface of the paper as a coating is used. In each case, the microcapsules are torn open by the writing or copying pressure and the solution of the color former contained therein is brought into contact with the electron-accepting substance, whereby a colored copied image is obtained.

The principle, the shape, as well as the manufacturing process, as described above, have long been known (see US Pat. Nos. 2,548,366, 2,711,375, 2,730,456, 2 73o 457, 2 812 5o7, 28oo 457 and 2 8oo 458).

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20A9279

The object of the invention is to provide a pressure sensitive Copy paper in which a novel compound is used as a color former.

The pressure-sensitive copier paper according to the invention is characterized in that it is on a carrier has a layer of microcapsules which, as a color former, are a compound of the general ones listed below formula

contains, wherein R _{1 is} an alkyl group with 1 to 4 carbon atoms, R ₂ and R., each a hydrogen atom, a halogen atom, an ITitro group, an alkoxyl group with 1 to 4 carbon atoms in the alkyl group, an alkoxy carbonyl

group with 1 to 4 carbon atoms in the alkyl group or an aldehyde group, especially a formyl group, mean. This compound can with an electron accepting substance forming a distinctive color implemented. .

The above compound is dissolved in a solvent such as benzene, toluene, dioctyl phthalate and chlorinated Diphenyl or the like., Dissolved, encapsulated in microcapsules and as a coating on the surface of paper upset.

In use, this material can be associated with a sheet that has the electrons specified above

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absorbing substance as a coating.

In addition, the microcapsules containing a solution of the above-described compound, and the electron-accepting substance can be applied as a coating to the surface of the paper at the same time. The microcapsules containing a solution of the color former can be prepared according to procedures as described in US Pat 2,800,457 and British patents 1,091,076, 1091,077 and 1091,078 will.

The compound represented by the above general formula is usually prepared according to the following procedure manufactured:

lower

2-aminobenzothiazole and a halogenated ^ alkyl or

p-Toluenesulfonic acid alkyl esters in equimolar proportions implemented. The quaternary salt thus obtained and an equimolar amount of a salicylaldehyde derivative can refluxed in ethanol in the presence of an equimolar amount of triethylamine, one being Compound of the formula given above is obtained.,

The implementation described above is carried out by the The reaction equations below are illustrated.

NH ₉ + R ₁ SO, /

1 0 9 B ι 7/20 b 3

2OA9279

13O ⁰ C

2-3 hours,

-P-Ts

■ Bf
ι

R-

-P-Ts

CHO

+ ■ HO

\ φ7

The compound thus obtained is sufficiently excellent Properties as a compound for a pressure-sensitive copier paper that leads to the formation of a red to red-violet color when brought into contact with the Electron-accepting substance is capable.

In the manufacture of a pressure-sensitive copier paper, the compound is used together with a common one Color formers, for example crystal violet lactone or benzoylleucomethylene blue, encapsulated in microcapsules, whereby different hues or colors, e.g. black, are obtained when the mixture of the color formers with the substance that accepts electrons is brought into contact.

α fl 1 7 / ο η

The invention is illustrated below by way of examples explained in more detail.

example 1

3.4 g of I-methyl ^ aminobenzothiazolium p-toluenesulfonate and 1.2 g of salicylaldehyde were dissolved in 25 ml of ethanol and 1 g of triethylamine was added, followed by refluxing for about 3 hours. Then was allowed to stand, bring crystals to crystallize to ψ, which is then filtered and was recrystallized from ethanol. 1.4 g of 3-methyl-spiro / benzothiazoline-2,2'-2'H- (1,3) -benzoxazine7 were obtained in the form of white crystals. The melting point of this compound was 155 to 159 ^° C

Elemental analysis 67, C. 4th H 9 N calculated (#) 67, 38 4th , 21 Io , 93 found ($) 15th , 51 , 44

The solution of this compound in benzene was enclosed in microcapsules and applied to the surface of paper applied as a coating, this paper was then combined with a construction paper, the surface of which with acidic white clay and a binder, whereupon this material was pressed by means of a typewriter or was printed. The pressed part was instantly colored red.

Example 2

3.4 g of 3-methyl-2-amino-benzothiazolium p-toluenesulfonate and 1.7 g of 5-nitrosalicylaldehyde were in 25 ml of ethanol dissolved and 1 g of triethylamine was added, whereupon during

C. 3 H N 9ο 57 , 76 3 , 85 13, 42 57 , 51 , 54 13,

was refluxed for about 3 hours. After 2.5 hours from the start of the reaction, / yellow crystals crystallized out. After standing, the crystals were filtered and recrystallized from benzene, where "2.3 g of 3-methyl-6'-nitrospiro- / eenzothiazoline-2.2-2 ^f H- (1,3) benzoxazine7 in the form of light yellow Crystals were obtained. The melting point of this compound was 195 to 198 ^° C.

Elemental analysis calculated. ($) found ( ^c / °)

When this compound was pressed in the same manner as described in Example 1, the pressed part became colored red-purple.

Example 3

34 g of 3-methyl-2-aminobenzothiazolium p ~ toluenesulfonate and 2 g of 3-i- ^1- methyl-5-nitrosalicylaldehyde were dissolved in 25 ml of ethanol and 1 g of triethylamine was added, which was then refluxed for about 3 hours. When the reaction liquid was concentrated to about a quarter and then cooled, orange colored crystals crystallized out. The crystals were filtered and recrystallized from ethanol, giving 2.1 g of 3-methyl-6'-nitro-e-forrnylspiro-Zdenzothiazolium ^, 2'-2 ¹ H- (1, 3) -benzoxazine / in the form of yellow crystals were obtained. The melting point of this compound was 162 to 165 ^° C.

Elemental analyzes:

calculated

found

C. 3 H 12th IT 55.92 3 , 66 12th , 9o 56.31 , 25 , 31

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When using this connection to write un1? Er Applying pressure in the same way as indicated in Example 1, the pressed part was colored red-purple.

Example 4

3.4 g of 3-methyl-2-aminobenzothiazolium-p-toluenesulfonate and 2.8 g of 3,5-dibromosalicylaldehyde were dissolved in 25 ml of ethanol and 1 g of triethylamine was added, followed by refluxing for 3 hours, and if so after Reaction was allowed to stand, white crystals crystallized out. These were filtered and recrystallized from a mixed solution of ethanol and benzene, whereby 3.3 g of 3-methyl-6 ', 8'-dibromospiro- / b "enzothiazolin-2,2'-2 ^! H- (1,3) -benzoxazin7 were obtained in form of white crystals. The melting point of this compound was at 192-194 ⁰ C.

When the solution of this compound in chlorinated diphenyl was applied to the surface of the paper as a coating and then to the surface of the clay paper and the two papers were pressed, the pressed part was instantly colored red.

Example 5

1 »7 δ 3-methyl-2-aminobenzothiazolium-p-toluenesulfonate and 3-methoxy-5-nitrosalicylaldehyde were dissolved in 20 ml of ethanol and 0.5 g. Triethylamine was added and refluxed for about 2 hours. When cooling was carried out after the reaction, yellow-brown crystals crystallized out. These were filtered and recrystallized from ethanol to give 1.2 g of 3-methyl-6 ^f -nitro-8'-methoxyspiro- ^ eenzothiazoline-2,2'-2 'H- (1,3) -benzoxazine7 were obtained in the form of light yellow crystals. The melting point of this compound was 195 to 198 ^° C.

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Elemental analysis: 56, O H IT 51 calculated (#.) 55 ·, 2o 4, o8 12, 24 found ($) example 98 3.82 12, 6th

10 g of an aqueous solution of the compound obtained as in Example 2 in chlorinated diphenyl was added to 100 g of an aqueous solution of 10% of methyl cellulose, followed by vigorous stirring to obtain an emulsion. This emulsion was then applied to the surface of the paper as a coating and dried. The thickness of the coating layer was 8o / u.

When the color-producing paper is placed on a construction paper and by the pressure of a writing implement in the same When pressed in the manner described in Example 1, the pressed part was instantly colored red.

Example 7

The paper coated with the compound obtained in Example 5 on its surface and in the same way as had been dried in Example 6, it was dyed red after placing it on a construction paper and pressing.

Example 8

The compound contained in Example 4 was prepared according to the procedure described in Japanese Patent No. 493,064 encapsulated. This capsule solution was applied as a coating to a paper surface and dried, y / hen the pattern formation paper thus obtained on a construction paper was placed and printed, the printed or pressed part was instantly colored red »

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Claims (2)

- Io - claims 1. Pressure-sensitive copier paper, characterized in that it has a coating of on a carrier Has microcapsules containing a compound of the general formula below contain, in which R-, an alkyl group with 1 to 4 carbon atoms, Rp ^{urL <} ^ ^ 3 in each case a hydrogen atom, a halogen atom, a nitro group, an alkoxyl group with 1 to 4 carbon atoms in the alkyl group, an alkoxycarbonyl group with 1 to 4 carbon atoms in the dei Represent an alkyl group or an aldehyde group, this compound being reactive with an electron accepting substance to form a distinct color. 2. Pressure-sensitive copier paper according to claim 1, characterized in that the compound of 3-methylspiro- ^ ~ benzothiazoline-2,2'-2'H- (1,3) -benzoxazin7 »3-methyl-6 '~ nitrospiro-- / b "enzothiazoline-2,2 '-2 · Η- (1,3) -benzoxazine /» 3-methyl-6' -nitro-8 '-formylspiro- / be nzothiazoline-2,2' -2 ¹ H - (1,3) -benzoxazin7 »3-methyl-6 ', 8'-dibutylspiro- / b" enzothiazo ·· lin-2,2'-2'PI- (1,3) -benzoxazin7 or 3-methyl- 6'-nitro-8 · - methoxyspiro- / 5enzothiazoline-2,2 ^f -2 ¹ H- (1,3) -benzoxazine / consists. 109817/2053