DE2164512A1 - Recording sheet and process for its manufacture - Google Patents

Description

PATENT LAWYERS

dr.iivg. H. NEGENDANK · dipl-ing. H. HATJCK graduate phys. W. SCHMITZ

HAMBURG-MUNICH ADDRESS FOR DELIVERY: HAMBURG 38 · NEW ER WAT.T. 41

TEL. 367428 AND 364110

TElEGH. NEGATIVE HAMBUBG

Kanzaki Paper Manufacturing Munich 15 · mozartstr. 23

TEL. 0 3 8 0 0 8 6 DO », Ltd · TELEGH. NEGEDAPATENT MUNICH

9-8 Yonchome, Ginza, Chuo-ku, "_

'Hamburg, December 22, 1971

Tokyo, Japan

Registration form and procedure for his Manufacturing

The invention relates to a recording medium with color-forming Components that react with one another to form a visible color after contact, and a process for making the bow.

Label-forming systems in which an electron donor-acceptor reaction between basic dyes and monomeric phenols is used for color formation, e.g. heat-sensitive or pressure-sensitive recording systems are known. In these systems the color-forming ones exist Components made from basic dyes and monomeric phenols, which are formed upon reactive contact with one another a visible color react, making contact by the application of heat or pressure with or without presence a solvent is achieved. The reactive contact described here means that the molecular distance between Electron donor and electron acceptor small enough

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so that a color-forming reaction can take place by donating and accepting electrons. An example of such a known recording system is described in Australian patent specification 402 733, which corresponds to US patent application Ser. No. 554 565; This is a heat-sensitive recording material consisting of a Trägerbiatt, but which is, _Ä liquid with Kristallviolettlac ton and a phenolic material which is solid at room temperature at normal thermograph-temperature and / or vaporized, is applied. Attempts have been made to use monomeric phenols such as 4-tert-but-.ylphenol, 4-phenylphenol, OL -naphthol, 4,4 ^l -isopropylidene-diphenol, etc. as phenolic materials.

It is an object of the invention to provide an improved recording material in which a deep-colored image is formed on the surface of the recording sheet generated by ultrasonic vibration energy, which is brought into action directly and locally on the sheet surface will. . ·.

The transmission system according to the invention brings a number of advantages: it is free from the influence of mechanical inertia, a transmission system such as photoelectronic Transfer, "is not required, and conversely, small changes to the recording device make it

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tion, the simplicity of construction and the high sensitivity possible with the system running at high speed Copy machines, facsimile system, etc. to use.

A transfer sheet has been created that is capable of producing a highly visible image when it is exposed to energy such as heat, frictional pressure, electromagnetic waves and ultrasonic vibration, whereby reactive contact between electron donor and electron acceptor is brought about. In particular, the recording sheet of the present invention has greater sensitivity to ultrasonic vibration energy and is therefore usable in the improved recording system.

The above object is achieved by a recording sheet with solid particles of the color-forming components, which consist of (a) leuco dyes, (b) polymeric phenol-aldehyde condensates and (c) monomeric substituted phenols. The monomeric substituted phenols have the general formula below

OH

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in which R is an alkyl group with four to 20 carbon atoms, an aralkyl group, a substituted aralkyl group, a Denotes a phenyl group, a substituted phenyl group or a cycloalkyl group. The weight ratio of polymeric phenol-aldehyde condensates to form monomeric substituted ones Phenols should be in the range of 90 to 10 to 10 to 90.

The colorless, color-forming compounds that are ^ Findings are suitable include compounds with lactone rings, lactam rings and sultone rings, which for themselves are colorless or light in color, but convert to a color upon contact with acidic materials, Such compounds are commonly referred to as "leuco compounds" or "leuco dyes"; those listed below Compounds or combinations thereof are given as examples of leuco dyes:

3,3-bis (p-Diraethylaminophenyl) -6-dimethylaminophthalide

■ (crystal violet lactone)

3,3-bis (p-dimethylaminophenyl) - &, 5, 6, 7-tetrachlorophthalide

. '9- (p-nitroanilino> 3 f 6-bis (diethylamino) -9-xanthenyl-ο -B enaae acid e-1 ac t am

(Rhodamine-B-lactam)

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3,3-bis (p-dibutylaminophenyl) phthalide (Malachite green lactone)

3,3-bis (p-dipropylaminophenyl) phthalide

3,3-bis (p-dimethylaminophenyl) -6-aminophthalide

3,6-bis (diethylamino) -9-hydroxy-9-xantheneqa.-benzenesulfonyl sultone

2- (2 ^f , 4 ', 6 ^t -trimethylphenylamino) -8-diethylamino-3,4-benzofluoran

2,8-Di (n-ethyl-N-p-toluylamino) -fluorane 3-diethylamino-6-methylchlorofluorane

Typical examples of polymeric phenol-aldehyde condensates are p-phenylphenol-formaldehyde condensates, p-terfc-butylphenol-formaldehyde condensate, p-octylphenol-formaldehyde condensate, phenol-formaldehyde condensate, cresol-formaldehyde condensate, phenol-acetaldehyde Condensate, etc. Typical examples of monomeric substituted phenols are p-phenylphenol, p-tert-butylphenol, p-octylphenol, p-benz / phenol, 2,2-bis (4'-hydroxyphenyl) propane, p-benzylphenol, 2 , 2-bis- (4 ^f hydroxyphenyl) -sec-isobutane, p- (4 ¹ chlorophenyl) phenol, cyclohexylphenol, etc.

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The polymer preferably used in the invention Phenol-aldehyde condensate is a material commonly referred to as "novolac" which has a free hydroxyl group has, in the absence of a crosslinking agent, is meltable and insoluble in water.

For the invention, suitable phenols are those which are solid at room temperature but become liquid at normal temperatures thermograph from 90 to 200 ⁰ C. It should be noted, however, that the melting point of the phenols is not an indispensable factor in the recording system described.

One of the basic features of the recording sheet according to the invention is that the polymeric phenol-aldehyde condensates and the monomeric substituted phenols in the color-forming components within a certain weight ratio, namely in the ratio of 90 to 10 to 10 to ^ 90 can be used. This relationship is critical, as will emerge from the examples given later. It is found that the components used in accordance with the invention have a very high chemical activity in the color formation reaction. This found effect or advantage

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is expediently used in the above recording system; the recording system would not be possible with the usual recording sheets. Monomeric phenols or polymeric phenol-aldehyde condensates, for example, cannot be used alone and not in combination with one another and cannot be used successfully in the recording system. The recording sheets according to the invention can be used as recording sheets wärmeeiqfindlicher operate when the phenolic material is selected from materials therein, which are solid at Raurataperatur, but liquefy at ordinary temperatures thermograph from 90 to 200 ⁰ C.

The above advantages of this invention will become more apparent from the examples given below and the accompanying drawings .

The recording sheet according to the invention can be produced by applying an aqueous or non-aqueous suspension in which the color-forming components are dispersed as small solid particles to a base sheet. In these cases , it is appropriate that the color-forming components are applied closely to one another on the base sheet so that the color-forming components easily accept a locally applied energy

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one side with a suspension which contains the solid particles of color-forming components, applied. The above method is particularly suitable for producing a recording sheet for the above-mentioned recording system. The solvent, that used in the non-aqueous suspension must be selected from those solvents that do not dissolve the color-forming components. Examples for such solvents are aliphatic hydrocarbons with 5 to 12 carbon atoms, such as n-paraffin hydrocarbons, Isoparaffinic hydrocarbons and cycloparaffinic hydrocarbons. However, ordinary aqueous systems are more preferable than non-aqueous systems, because they are more economical and easier to use, safer to work with and the like.

If necessary, an adhesive or binding agent such as polyvinyl alcohol can be added to the suspension, Carboxymethyl cellulose, hydroxyethyl cellulose, casein, starch, synthetic latices and the like, by which the solid particles made of color-forming components are glued to the base sheet. Paper can be used as the base sheet or synthetic polymers forming sheets can be used, but paper is preferred because it is the most economical

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and can be easily deformed (convert).

One of the improvements in the manufacturing process according to the The invention is the adjustment of the pH of the aqueous suspension containing the color-forming components to a value between 6.0 and 11.0 by adding basic Materials or buffers such as sodium hydroxide, potassium hydroxide, ammonia, lower amines and basic salts thereof as well Urea and thiourea. Adjusting the pH value helps to make the substrate look shaggy avoid what often happens during storage or recording. Before further improvement of the invention The method consists in subjecting the coated and dried sheet to a calendar treatment, e.g. with a supercalender. When the surface of the recording sheet is smoothed by this treatment it can evenly absorb energy from a recording pen or a needle. This treatment does the coating layer is also stronger because the coating layer can be mechanically compacted. This allows the crowd Adhesive in the suspension can be saved and the mutual contact of the color-forming components is facilitated. A further improvement is the production of solid particles of phenolic material by uniformity Mixing the polymeric phenol-aldehyde & condensates and the monomeric substituted phenols in the molten state

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and cooling to the solidification point, followed by pulverization. The phenolic solid particles thus obtained are more strongly activated in the color formation reaction. The particle size of the phenolic materials of the invention should be between 1 and 5 microns. The size is not limited to this area, but can can be set arbitrarily according to the required screen resolution. ·

Reference is made below to the attached figures, of which show:

Figures 1 and 2 an exemplary device, which

reproduces improved recording system according to the invention

Fig. 3 is a photograph of the results obtained in the examples given below.

In Fig. 1, electrodes 11 are attached on opposite sides of a ceramic piezoelectric substance 12 the end of which is connected to a pen 13 · This pen can hold a piano code with a width of 700 Microns, a thickness of 15 microns and a length of 3 mm

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be. Its edges come into light contact with the surface of the current recording sheet 14, for example under a pressure of 1 to 6 g. When AC signals are applied to the ceramic piezoelectric substance 12 from an AC power source 16 are applied, this causes a continuous expansion and contraction of the substance 12, what vibrates the pen 13 according to the frequency of the AC signal, and the vibration energy is transferred to the surface of the recording sheet 14. Although the oscillation frequency is preferably between 10 and 100 KHz, it is not limited to this range, but can according to the resonance frequency of the ceramic electrical substance that is used, to be determined. The optimal frequency can be selected at will depending on the size and shape of a pen, the recording speed, the running speed and the sensitivity of the recording process, the Line density of the pen, etc. The vibration energy causes the actual contact between the color-forming ones Components and, as a result, a visible image on the surface of the recording sheet becomes corresponding the pattern of alternating electrical signals applied. The device shown in Fig. 2 has a multiple cutting pen 15, consisting of a number of pens 15 ', each of which has a line density of 3 to 5 lines per mm has and is practically applicable to the generation of any type pattern

is. .

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The invention is now based on the following »examples not represent a limitation, are described in more detail. In the examples, the amounts are given in parts by weight.

example 1

13.5 parts of p-phenylphenol (Fp.i69 ° C) were uniformly mixed with 1.5 parts of polymeric ^ p-phenylphenol-formaldehyde condensate (50:50, mp. 140 ⁰ C) are mixed under melting conditions. At this point the weight ratio of the two materials was 90:10. This mixture was then solidified by cooling and pulverized. The powdered mixture was then mixed in a ball mill for three hours with 0.4 parts of an anionic wetting agent (as a dispersant), 0.3 part of hydroxypropyl cellulose (as a viscosity regulator) and 59.8 parts of water. The particle size of the phenolic materials so premixed was about 3 to 5 microns after ball mill treatment.

Component B

2- <2 ', 4', 6'-trimethylphenylamino) - 0.7 parts by weight 8-diethylamino-3 »4-benzofluorane.

2,8-Di (N-ethylN-p-toluylamino) - 0.5 part by weight of fluoran

Rhodamine B anilide 0.7 part by weight

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3-diethylamino-6-methylchloro-0.5 part by weight

fluoran

anionic wetting agent 0.1 part by weight

Water 15.2 parts by weight

The mixture of the above composition was milled in a ball mill for two hours. The particle size the colorant was about 3 to 5 microns after ball mill treatment.

75.5 parts of the resulting component A and 17.7 parts of component B were uniformly mixed with 2.7 parts of styrene-butadiene copolymer latex with a solids content of 50% (Dow latex 620) and 2.8 parts of a 10% strength Potassium hydroxide solution mixed. The pH of the final suspension was about 11.0. Then this became. Suspension applied to one side of a base paper weighing 50g / sqm in a thickness of 5 g / sqm dry weight. The coated sheet was then ait a roll pressure of 12.5 kg / cm supercalendered.

Examples 2. 3. 4. 5 »6. 7. Control example A and Coriroll example B

Each of these IteL games were the same as Example 1, except that the p-phenylphenol and the polymeric p-phenyolphenol-formaldehyde condensate were used in the following weight ratios:

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p-phenylphenol polymeric p-phenyl parts) phenol-formaldehyde .ieiie; Condensate (parts by weight)

Weight ratio

Example 2 Example 3 Example 4 Example 5 Example 6 Example 7

12 9

7.5 6 3 1.5

Control example A 15 Control example B -

3 6

7.5 9

12 13.5

80 60; 50! 40 s 20 y 10: ί 20 ί 40 ι 50 ί 60 : 80 ι 90

15th

100 s 0 0: 100

The control examples given above A and B corresponded to the Example 1 except that p-phenylphenol DAB (Pp. 169- ⁰ C) and the polymeric p-phenylphenol-formaldehyde condensate (50:50, mp. 140 ⁰ C) individually were used, namely, in the preparation of these control examples, each of the above-mentioned materials was used individually as small particles and mixed with the other components in the ball mill.

Those from the examples given above and the control examples obtained products, i.e., the recording sheets tested using the device shown in Fig. 1,

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Each record sheet obtained by any of the above Examples and Control Examples was subjected to a recording test using the apparatus of Fig. 1: Ultrasonic energy generated according to alternating electrical signals of 100 volts (effective) at a frequency of 30 KHz locally by applying the pen to the surface of the recording sheet running at a speed of 50 mm / minute. In addition, the surface of the recording sheet was scanned with a hot pen at a temperature of 200 ° C. The results of the tests are shown in the photograph of FIG. The dashed lines in Fig. 3 show the colored image created by the ultrasonic vibration energy, and the two lines on the right are the colored images created by the hot pen.

This photograph reproduced in FIG. 3 clearly shows that the use of p-phenylphenol (control example A) as well as polymeric p-phenylphenol-formaldehyde condensate (control example B) is in itself not applicable to this described recording system. It also shows that the Recording sheet according to the invention is a significant improvement over a non-heat-sensitive recording sheet. represents bow.

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Example 8

This example was the same as Example 1 except that 7.5 parts of small solid particles of p-phenylphenol and 7.5 parts of small solid particles of polymeric p-phenylphenol-formaldehyde condensate without premixing, with 0.4 parts of anionic wetting agent, 0.5 part of hydroxypropyl cellulose and 59.8 parts Water mixed in the ball mill to produce component A. became. The obtained recording sheet was tested in the same manner as in Example 1 and they became the same Results obtained as Fig. 3 for Example 1 shows.

Beialel 9

Component A:

8 parts of polymeric ρ-tert-butylphenol-formaldehyde condensate (50:50, mp. 128-131 ° C) were uniformly mixed with 1.2 parts of p-phenylphenol (mp. 169 ⁰ C) were mixed together in a molten state. At this point, the weight ratio of the two materials was 87:13. This mixture was then solidified by cooling and pulverized. Furthermore, the pulverized mixture was treated in a ball mill for three hours with 10 parts of a 20% Nylgum A-85 solution (starch esterified with phosphoric acid, a product of WASholten's Chemishe Fabrieken NV, Holland) and 70 parts of water.

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Component B

10 parts of crystal violet lactone and 10 parts of benzoyl leucomethylene blue were mixed with 10 parts of 2Q? 6 Nylgum A-85 solution and 70 parts of water for two hours. ;

75 parts of component A and 15 parts of component B were evenly mixed with 2.7 parts of styrene-butadiene copolymer latex having a solids content of 50%. The finished suspension was then applied to one side of a base paper weighing 50 g / m² in a thickness of 5 g / m², dry basis. The coated sheet was then supercalendered under a nip pressure of 12.5 kg / m².

The obtained recording sheet then became the same Manner as described in Example 1, and the same results were obtained.

Example 10
Component A:

25 parts of p-phenylphenol (m.p. 169 ° C) and 25 parts of polymer p-Phenylphenol-formaldehyde condensate (50:50, m.p. 140 ° C) carefully mixed together in the molten state. This mixture was then solidified by cooling and pulverized. The powdered mixture was in the ball mill for two hours with 100 parts of white spirit and 3 parts

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mixed with cyclized rubber. The particle size of the premixed phenolic material was about 3 to 5 microns after ball mill treatment.

Component B

10 parts of crystal violet lactone were used for three hours Ball milled 20 parts of white spirit and 0.5 part of cyclized rubber. The particle size of the dye was about three to five microns after ball mill treatment.

100 parts of component A and 20 parts of component B were mixed together uniformly. Then this became Suspension on one side of glassine paper of 40 g / m² Applied in a layer thickness of 5 g / m², based on dry weight. The coated sheet was then placed under a Nip pressure of 12.5 kg / qcm supercalendered.

The recording sheet obtained was similarly .. Wk ' . how

tested as example 1 and the same results / in example 1 were obtained.

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Claims (8)

Claims ί 1.) Recording sheet consisting of a base sheet and color-forming components in the form of small particles that are connected to the base sheet, characterized in that that the color-forming components from (a) leuco dyes, (b) polymeric phenol-aldehyde condensates and (c) monomeric substituted phenols of the general Formula OH in which R is an alkyl group with 4 to 20 carbon atoms, an aralkyl group, a substituted aralkyl group, a phenyl group, a substituted phenyl group or means a cycloalkyl group, where the weight ratio from polymeric phenol-aldehyde condensates to monomeric substituted phenols in the range of 90: to 10:90, and that after exposure to an energy, which reactive contact between the color-forming Components causes a visible image to appear on the surface of the recording sheet, 2. recording pool according to claim 1, characterized in that that the color-forming components are applied in the form of a coating layer on a surface of the base sheet are. - 20 - 209831/0574 3. Recording sheet according to claim 2, characterized in that each of the components (b) and (c) is solid at room temperature, but liquefies ^{at a temperature between 90 and 200 ° C.} 4. Recording sheet according to any one of the preceding claims, characterized in that the polymeric phenol-aldehyde condensates and the monomeric substituted phenols are present in the coating layer as individual small solid particles. 5. Record sheet according to any one of the preceding claims, characterized in that the polymeric phenol-aldehyde condensates and the monomeric substituted phenols present as premixed small solid particles in the coating layer. 6. Record sheet according to any one of the preceding claims, characterized in that the coating layer is a calendered smooth surface. 7. Process for the production of the recording sheet according to any one of claims 1 to 6, characterized in that the color-forming components (a, b and c) are based on one Side of the base sheet in the form of an aqueous suspension - 21 - 209831 / 0B74 a pH in the range of 6.0 to 11.0 can be applied. 8. The method according to claim 7, characterized in that components (b and c) as premixed small solids particles are suspended. 209831/0574