Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
  • B41M5/337—Additives; Binders
  • B41M5/3375—Non-macromolecular compounds

Definitions

• the invention relates to a heat-sensitive recording sheet which has a superior color formation effect and a high stability against hair oil, sweat and skin secretions etc.
• a heat-sensitive recording sheet using a heat color reaction between a colorless or weakly colored chromogenic dye and a phenolic substance or an organic acid is disclosed in Japanese Patent Publications 4160/1968 and 14039/1970, among others, and in Japanese Laid-open specification 27736/1973. There is currently a wide variety of practical applications.
• a heat-sensitive recording sheet is generally prepared by applying a coating color to the surface of the support such as paper, film, etc., which by fine grinding and dispersing a colorless chromogenic dye and a color developing material such as phenolic substances into fine particles by mixing the dispersions obtained and by adding a binder, filler, sensitizer, lubricant and other auxiliaries.
• heat-sensitive recording sheets are widely used in practice, including medical and technical recording equipment, terminal printers of computers and information systems, printers of facsimile machines and electronic calculating machines, ticket machines and the like.
• the invention has for its object to provide a heat-sensitive recording sheet in which the recording image is very stable to the action of oily materials such as hair oil, sweat, etc. and the quality of the recording material is not impaired.
• This object is achieved in the case of a heat-sensitive recording sheet in that it contains benzyl p-benzyloxybenzoate in the color formation layer which contains a basic colorless or slightly colored chromogenic dye and an organic color developing agent.
• Benzyl p-benzyloxybenzoate is obtained as a by-product by partial etherification of the OH group of the p-hydroxybenzoate when p-hydroxybenzoate (potassium or sodium salt) and benzyl chloride and benzyl chloride are used to synthesize benzyl p-hydroxybenzoate as a color developing agent for heat-sensitive recording sheets. Therefore, benzyl p-benzyloxybenzoate was previously considered an unnecessary product.
• the yield of the p-hydroxybenzoic acid benzyl ester is low, so that measures to prevent this side reaction or steps to remove this side product were required.
• p-hydroxybenzoic acid benzyl ester can be controlled in the required ratio, and the two chemicals can be used in a mixture, which has a cost-effective effect.
• Benzyl p-benzyloxybenzoate can be synthesized alone or can be obtained as a by-product by separation. Then, if desired, it can be used with various color developing agents.
• Organic acids or phenolic substances such as bisphenol A, (4,4'-isopropylidene diphenol), p-p '(1-methyl-n-hexylidene) diphenol, p-tertiary butylphenol, p-phenylphenol, novolak phenolic resins and p-Hydroxybenzoic acid benzyl ester used.
• Such organic color developing agents are used alone or in a mixture, depending on the use and skills required.
• the above-mentioned organic color developing agents, the colorless chromogenic dyes and benzyl p-benzyloxybenzoate are ground to a particle size of several microns or smaller by means of a grinder such as a ball mill, attritor, sand grinder, etc. or by a suitable emulsifying machine.
• a grinder such as a ball mill, attritor, sand grinder, etc. or by a suitable emulsifying machine.
• additives are added to this, depending on the intended use, in order to produce the coating color.
• the additives that can be used according to the invention are e.g. B. the following:
• Binders such as polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, starch, styrene-maleic anhydride copolymers, vinyl acetate-maleic anhydride copolymers, styrene-butadiene copolymers, etc. inorganic or organic fillers, such as kaolin, burnt kaolin, diatomaceous earth, talc , Calcium carbonate, magnesium carbonate, aluminum hydroxide, etc .; Release agents such as metal salts of fatty acids: lubricants such as waxes, UV absorbers of the benzophenone and triazole series, waterproofing agents such as glyoxal, etc. dispersants, anti-foaming agents etc.
• the desired heat-sensitive sheet is obtained by applying this coating color to a paper or on different films.
• the amount of benzyl p-benzyloxybenzoate according to the present invention, and the kind and amount of the other constituents, which are determined depending on the desired effect and suitability for recording purposes, are not particularly limited.
• Solution B (dispersion of color developing agents):
• a heat sensitive recording sheet is pressed against a hot plate under a pressure of 10 g / cm 2 for 5 seconds, and the optical density of the image is measured with a Macbeth RD-104 densimeter.
• Hair liquid (manufactured by Shiseido Company, Limited) is taken up with a syringe. A drop of hair fluid is pressed from the syringe needle onto an index finger, spread the thumb on the index finger and transferred with the index finger to the surface of a heat-sensitive recording sheet that has been colored. The optical density of the image is measured with a Macbeth RD-104 density meter 10 days after the hair fluid has been contaminated.
• the preparation of the example according to the invention which contains benzyl p-benzyloxybenzoate, has a residual image density of 99.2%.
• the picture is therefore fairly stable to contamination with the hair liquid.
• These coating colors were applied in a coating amount of 6. 0 g / m 2 to a base paper with a weight of 50 g / m 2 , dried and supercalendered to adjust a smoothness of 200-300 seconds.
• the heat-sensitive recording sheets obtained which formed a black color, were tested for their quality and their behavior, using castor oil instead of the hair liquid as the soiling material.
• the results are summarized in Table 2.
• the heat-sensitive recording sheet using bisphenol A as a color developing agent has a much higher residual image density after being contaminated with a castor oil than the comparative product.
• Benzyl p-benzyloxybenzoate gives the product great stability against the effects of polluting substances.
• Solution B (dispersion of color developing agents):
• These coating colors were applied in a coating amount of 6.0 g / m 2 to a base paper with a weight of 50 g / m 2 , dried and supercalendered to set a smoothness of 200-300 seconds.
• the heat-sensitive recording sheets were provided with recording images at a pulse width of 3.0 milliseconds and an applied voltage of 18.0 V using a facsimile machine for the test, manufactured by Matsushita Electric Industrial Co., Ltd., the optical density of which was determined by a Macbeth density meter from Type RD-104 can be determined.
• the heat-sensitive recording sheet using bisphenol A as a color developing agent and crystal violet lactone as a basic colorless chromogenic dye has a much higher residual image density after being contaminated with a castor oil than the comparative product.
• Benzyl p-benzyloxybenzoate gives the product great stability against the effects of polluting substances.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Heat Sensitive Colour Forming Recording (AREA)
• Color Printing (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=13846796

Family Applications (1)

Country Status (4)

Cited By (2)

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Citations (2)

Family Cites Families (1)

• 1981
  • 1981-06-04 JP JP56085011A patent/JPS57201691A/ja active Pending
• 1982
  • 1982-05-28 DE DE8282104725T patent/DE3265598D1/de not_active Expired
  • 1982-05-28 EP EP82104725A patent/EP0066813B1/fr not_active Expired
• 1986
  • 1986-06-04 US US06/870,453 patent/US4719198A/en not_active Expired - Lifetime

Patent Citations (2)

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