US3816838A

US3816838A - Method of making recordings in a recording sheet material

Info

Publication number: US3816838A
Application number: US00210885A
Authority: US
Inventors: T Higaki; M Mikumo
Original assignee: Kanzaki Paper Manufacturing Co Ltd
Current assignee: Kanzaki Paper Manufacturing Co Ltd
Priority date: 1970-12-28
Filing date: 1971-12-22
Publication date: 1974-06-11
Anticipated expiration: 1991-06-11
Also published as: BE777296A; DE2164512C3; SE377780B; DE2164512A1; CA937050A; DE2164512B2

Abstract

A method of making recordings in a recording sheet material is disclosed, wherein the base sheet is applied with a suspension containing finely divided solid particles of color-forming components which essentially comprises (a) leuco dyes and (b) phenolic-aldehyde polymeric condensates and (c) particular types of monomeric substituted phenols the weight ratio of said components (b) and (c) in the range from 90 : 10 to 10 : 90. The resultant product can produce an excellent color-formation when reactive contact among the color-forming components is caused by imparting heat or an ultrasonic vibrating energy.

Description

United States Patent 1191 Higaki et a1.

[ 1 June 11, 1974 1 1 METHOD OF MAKING RECORDINGS IN A RECORDING SHEET MATERIAL [75] Inventors: Taiii l-ligaki, Nishinomiya; Masao Mikumo, Amagasaki, both of Japan [73] Assignee: Kanzaki Paper Manufacturing Co.,

Ltd., Amagasaki, Hyogo, Japan 221 Filed: Dec. 22, 1971 21 Appl. NO.Z 210,885

[30 Foreign Application Priority Data Dec, 28, 1970 Japan 45-127821 Dec. 29, 1970 Japan 45-126386 [52] US. Cl 346/1, 117/362, 117/368, 117/369, 204/l59.21, 346/135 [51] Int. Cl. (101d 9/00, B41m 5/22 [58] Field of Search 117/362, 36.8, 36.9; 204/1592]; 346/135, 1

[56] References Cited UNITED STATES PATENTS 2,661,998 12/1953 Pessel 346/] 3,162,763 12/1964 Huett et a1 117/368 3,466,184 /1969 Bowler ct al l l7/362.2 3,466,185 9/1969 Taylor 117/362 3,539,375 11/1970 Baum 117/369 3,576,660 4/1971 Bayless et al. 117/368 3,672,935 6/1972 Miller et al. 117/369 Primary ExaminerWi11iam D. Martin Assistant Examiner-William B. Trenor Attorney, Agent, or Firm-Morgan, Finnegan, Durham & Pine [5 7] ABSTRACT A method of making recordings in a recording sheet material is disclosed, wherein the base sheet is applied with a suspension containing finely divided solid particles of color-forming components which essentially comprises (a) leuco dyes and (b) phenolic-aldehyde polymeric condensates and (c) particular types of monomeric substituted phenols the weight ratio of said components (b) and (c) in the range from 90 10 to 10 90. The resultant product can produce an excellent color-formation when reactive contact among the color-forming components is caused by imparting heat or an ultrasonic vibrating energy.

5 Claims, 3 Drawing Figures PATEMTEDJUN H 1914 3L816L838 SHEET 2 0F 2 FIG. 3

CONTROL A I 1 m EXAMPLE 1| l 1 H] EXAMPLE 2 L i{ J EXAMPLE 5 4H] EXAMPLE 4 L 4 H] EXAMPLE 5 L EXAMPLE 6 A4 EXAMPLE 7 L qm CONTROL B L A M] METHOD OF MAKING RECORDINGS IN A RECORDING SHEET MATERIAL v forming components which react upon contact to producea visible color, and also to a method for making the same.

Mark-forming system utilizing an electron donoracceptor color-forming reaction between basic dyes and monomeric phenols such as heat-sensitive or pressure-sensitive recording system is well known. In such system, color-forming components comprising basic dyes and monomeric phenols react upon reactive contact to produce a visible color with the contact being achieved by the use of heat or pressure with or without the existence of any solvent. The reactive contact herein described means that the molecular distance between electron donor and electron acceptor is close enough to each other to cause an electron donoracceptor colorforming reaction. As an example of such prior recording system, Australian Pat. No. 402,733 (corresponding to US. Pat. No. 3,539,375, issued Nov. 10, I970) discloses a heat-sensitive record material comprising a support sheet having crystal violet lactone and a phenolic material solid at the room temperature but capable of liquefying and/or vaporizing at normal thermographic temperature. Attemps have been made to use suchmonomeric phenols as 4-tertiary-buthylphenol, 4-phenylphenol, a-naphthol, 4,4'-isopropy1idene-diphenol and etc. as phenolic materials.

SUMMARY OF THE INVENTION We have successfully developed an improved recording system in which a deep color image is produced on the surface of recording sheet through ultrasonic vibrating energy imparted directly and locally on the sheet surface.

The above mentioned novel recording system has a number of advantages such as free from the effect of mechanical inertia, unnecessity of using transforming system such as photo-electronic transformation, and vice versa, less defacement of recording equipment, a simple in constraction and high sensitivity, all of which make it possible to apply it to highspeed printer, facsimile system and etc. I

In the course of establishing the above recording sys-.

The recording sheet according to the invention comprises a base sheet having solid particles of colorforming components which essentially comprises (a) leuco dyes, (b) phenolic-aldehyde polymeric condensates and (c) monomeric substituted phenols. The

monomeric substituted phenols should have the following general formula:

wherein R is alkyl group having four to 20 carbon atoms, aralkyl group, substituted aralkyl group, phenyl group substituted phenyl group or cycloalkyl group. The weight ratio of phenolic-aldehyde polymeric condensates to monomeric substituted phenols should be within the range of from 10 to 10 90.

Among the colorless dyes useful in this invention there are included the compounds having lactone ring, lactam ring or sultone ring, which are colorless or light color for themselves but react with acidic materials upon contact to produce a color. Such compound is generally called as leuco dye, and the following compounds or combination thereof may be mentioned as typical leuco dyes:

3,3-bis(p-dimethylaminophenyl)'6- dimethylaminophthalide (crystal violet lactone) 3,3-bis(p-dimethylaminophenyl)4,5,6,7- tetrachlorophthalide 9-(p-nitroanilino)-3,6-bis(diethylamino)- 9-xanthenyl-o-benzoic acid lactam (rhodamine B lactam) 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-xanthenoylbenzensulfonic sultone 2-(2',4,6-trimcthylphenylamino)-8-diethylamino- 3,4-benzofluorane 2,8-di(n-ethyl-N-ptoluylamino)-fluorane 3-diethylamino-o-methylchlorofluorane Typical examples of phenolic-aldehyde polymeric condensates are p-phenylphenol-formaldehyde polymeric condensates, p-ter-butylphenol-formaldehyde polymeric condensate, p-octylphenol-formaldehyde polymeric Condensate, phenol-formaldehyde polymeric condensate, cresol-formaldehyde polymeric condensate, phenol-acetaldehyde polymeric condensate, and so forth. And, typical examples of monomeric substituted phenols are p-phenylphenol, p-ter-butylphenol, p-octylphenol, p-pentylphenol, 2,2-bis(4'-hydroxyphenyl)propane, p-benzyl-phenol, 2,2-bis (4'-hydroxyphenyl)-sec-isobutane p-(4'-chlorophenyl)phenol,cyclohexylphenol and so forth.

The most useful phenolic-aldehyde polymeric condensate in this invention is a material generally called as novolack which has a free hydroxyl group and fusability in the absence of cross-linking agent and is water insoluble.

Among the phenolic material useful in this invention there are included the materials which are solid under the room temperature but liquefied under normal thermographic temperatures of 90-200 C. However, it should be noted that the melting point of phenolic materials is not an indispensable factor in the recording system described.

cording sheets'For example, monomeric phenols or thermographic temperatures of 90 200 C.

The above advantages of this invention are selfexplanatory from the examples described hereinafter and attached drawings.

The recording sheet of this invention may be produced by applying to a base sheet with an aqueous or non-aqueous suspension dispersing therein fine solid particles of color-forming components. In those cases, it is desirable that the solid particles of color-forming components are deposited to the base sheet in a mutually close position that the'color-forming components can easily accept a local energy. To comply with this requirements, the base sheet is coated on one side with a suspension system containing solidparticles of colorforming components. Particularly the above process is preferable in manufacturing a record sheet for the aforementioned recording system. The solvent used in the non-squeous suspension must be selected from the materials which do not solve a color-forming components. For the examples of such solvents there may be mentioned aliphatic hydrocarbons, having 5 12 carbon atoms such as n-paraffinic hydrocarbon, isoparaffinic hydrocarbon and cycloparaffinic hydrocarbon.

However, usually, aqueous systems are more preferable than non-aqueous systems from the view points of economy, handling, safety and others.

If necessary, the suspension system may be added thereto with adhesives or bonding agents such as polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, casein, starch, syntheric latices and etc., in order that solid particles of color-forming components may be sticked to the base sheet. Paper or synthetic polymeric materials of sheet form can be used' forsuch base sheet, but paper is more desirably used since paper is more economical and easy to convert. One of the improvements of manufacturing method of this invention is control the pH of aqueous suspension containing color-forming components between 6.0 and l 1.0 by addition of basic materials or buffers such as sodium hydroxide, potassium hydroxide, ammonia, lower amines and basic salts thereof as well as urea and thiourea. The control of pH helps to avoid smudge or background which often take place during storing or recording process. Another improvement is to put coated and dried sheet to a calender treatment by means of, for example, supercalender. As the surface of the recording sheet is smoothened by this treatment,

4 this can accept an energy from a stylus uniformly. Also, this treatment makes the coated layer stronger since the coated layer can be mechanically densified/This may also save the quantity of adhesives in suspension and to simplify the mutual contact of color-forming components. A further improvement is to prepare solid particles of phenolic materials by uniformly mixing phenolic-aldehyde polymeric condensates and monomeric substituted phenolsunder a melted condition,

and cooling it down to the solidifying point before pulverization. Phenolic solid particles so obtained are more activated in color-forming reaction. The particle size of phenolic materials under this invention is to be controlled between approximately I and 5 microns. However, this is not restricted within the above range since this may be voluntarily determined according to the required resolution.

, A BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 show a typical equipment showing the improved recording-system. In FIG. 1, electrodes 11 are attached on opposite sides of ceramic piezoelectric substance 12 on end of which a stylus 13 is connected: This stylus 13 maybe a piano code of 700 microns wide by 15 microns thick by 3 milimeters long, and the edge comes in slight contact with the surface of the running record sheet 14, say, under a pressure of 1 5 grams. When AC alternating electric signal is applied to the ceramic piezoelectric substance 12 from an AC source 16, the substance 12 causes a continuous expansion and contraction making the stylus 13 vibrate according to the frequency of the-AC signal, and the vibrating energy is imparted on the surface of the recording sheet 14. Although the frequency of vibration and preferably between from 10 KHz to KHz, this is not restricted within the above range since this may be determined according to the resonant frequency of the ceramic electric substance used. Optimum frequency can be chosen at will according to the size and the shape of the stylus, the recordingspeed, the running speed and the sensitivity of the recording sheet, the line density of the stylus and so forth. The vibration energy causes a virtual contact among color-forming components, and, as a result, a visible image is produced on the surface of recording sheet corresponding to the pattern of applied alternating electric signal. In FIG. 2, the equipment has multi-styli' 15 consisting of a'number of stylus 15' each of which has a line density of three five linesper milimeter practically capable of producing any type of pattern.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following examples serve to illustrate further the invention althoughthe invention is not limited to these examples. The amount of each example shows parts by weight. v Example 1 13.5 parts of p-phenylphenol (m.p. 169 C) was uniity controler) and 59.8 parts of water. The particle size of the above premixed phenolic materials was approximately 3 5 microns after ball-milling.

Component-E 2-(2',4',6-trimethylphenylamino)- 0.7 part 8-diethylamino'3,4-benzofluorane 2.8-di(NethylN-p-toluylamino)- 0.5 part fluorane rhodamine B-anilide 07 part 3-diethylamino-6-methylchrolo- 0.5 part fluoranc anionic surfactant 01 part water 15.2 parts The mixture with above formulation was ground by ball-milling for 2 hours. The particle size of the dyes was approximately 3 5 microns after ball-milling.

75.5 parts of resultant Component-A and 17.7 parts of Component-B were uniformly mixed with 2.7 parts of Dow-620 (styrene-butadiene copolymer latex, 50 percent of solid content, manufactured by Dow Chemical Co., USA) and 2.8 parts or percent potassium hydroxide solution. The pH of this final suspension was approximately 11.0. Then, this suspension was coated on one side of a base paper of 50 grams per square meter by the weight of 5 grams per square meter on dry basis. And further, this coated sheet was treated by super-calender under nip-pressure of 12.5 Kg/cm Example 2, 3, 4, 5,6, 7 Control-A and Control-B Each of these examples is similar to Example 1 except. that p-phenylphenol and p-phenylphenolformaldehyde polymeric condensate were used in the combination with following weight ratio.

The above Control-A and Control- B are similar to Example 1 except that each of p-phenylphenol (m.p. 169 C) and p-phenylphenol-formaldehyde polymeric condensate (5O 50 mp. 140 C) was'used singly. Namely, when the preparation of Component-A, each of above materials was used signly as fine particles and mixed with other components in the ball-mill.

The resultant products (i.e., recording sheet) obtained from above examples and controls were experimented using the equipment as shown in FIG. 1.

Each recording sheet obtained through above exam ples and controls was put to a recording test by means of the equipment as shown in FIG. 1. Namely, ultrasonic energy caused according to alternating electric signal of 100 V (effective) with frequency of 30 KHZ was locally applied from the stylus to the surface of the recording sheet running at a speed of 50 millimeter per minute. On the other hand, a hot stylus with a temperature of 200 C. scanned over the surface of the recording sheet. The results of the experiment are as shown in the photograph of FIG. 3. In FIG. 3, the dotted line shows the colored image brought about by ultrasonic vibrating energy, and two lines of on the right side show the colored image brought about by the scanning hot stylus.

This photograph of FIG. 3 clearly explains that the independent use of p-phenylphenol (Control-A) or p-phenyl-phenol-formaldehyde polymeric condensate (Control-B) cannot possibly be applied to the recording system described, and that the recording sheet according to the invention also provides a remarkable improvement as a no heat-sensitive recording sheet. Example 8 This example is similar to Example 1 except that 7.5 parts of fine solid particles of p-phenylphenol and 7.5 parts of fine solid particles of p-phenylphenolformaldehyde polymeric condensate were without premixing them, mixed with 0.4 part of anionic surfactant, 0.5 part of hydroxipropyl cellulose and 59.8 parts of water in the ball-mill at preparation stage of Component-A.

The resultant recording sheet was experimented in the same way as Example 1, and similar results as in Example 1 were obtained as shown in the attached photograph of FIG. 3.

Example 9 Component-A 8 parts of p-ter-butylphenol-formaldehyde polymeric condensate (50 50, mp. l28-l31 C) was uniformly mixed with 1.2 parts of p-phenylphenol (m. p. 169 C) under melt state. At that time, the weight ratio of both materials is 87: 13. This mixture was then solidified by cooling and repulverized. And further, this pulverized mixture was ground by ball-milling for 3 hours with 10 parts of 20 percent Nylgum A-85 (Starch phosphate ester, manufactured by W. A. Sholtens Chemishe F abrieken N-.V., I-Iolland) solution and parts of water.

Component-B 10 parts of crystal violet lactone and 10 parts of benzoyl leucomethylene blue were ground by ball-milling for 2 hours with 10 parts of 20 percent Nylgum A- (see above) solution and 70 parts of water.

75 parts of resultant Component-A and 15 parts of Component-B were uniformly mixed with 2.7 parts of Dow-620 (see Example 1). Then, this final suspension was coated on one side of a base paper 50 grams per square meter by the weight of 5 grams per square meter on dry basis. And further, this coated sheet was treated by super-calender under nip-pressure of 12.5 Kg/cm parts of p-phenylphenol-fonnaldehyde polymeric condensate (50 :50, mp. C) were uniformly mixed under melt condition. This mixture was then solidified t 7 by cooling and repulverized. Then, this pulverized mixture was ground by ball-milling for 2 hours with 100 parts of mineral. spirit and three parts of cyclolized rubber. Theparticle size of the above premixed phenolic materials was approximately 3 5 microns after ballmilling. Component-B 7 10 parts of crystal violet lactone was ground by ballmilling for 3 hours with parts of mineral spirit and 0.5 part of cyclolized rubber. The particle size of the above dye was approximately 3 microns after ballmilling.

100 parts of resultant Component-A and 20 parts of Component-B were uniformly mixed. Then, this suspension was coated on oneside of a glassine paper of 40 grams per square meter by the weight of 5 grams per square meter on dry basis. And further, this coated sheet was treated by super-calender under nip-pressure v of 12.5 Kglcm wherein R is alkyl group having four to 20 carbon atoms, aralkyl group, substituted aralkyl group, phenyl group, substituted phenyl group or cycloalkyl group, the weight ratio of said phenolicaldehyde polymeric condensates to' said monomeric substituted phenols being within the range of 90:10 to 10:90, and subjecting said recording sheet to ultrasonic vibrating energy to produce a color change in said coating layer corresponding to the desired recording. I

2. A process as defined in claim 1, wherein said phenolic-aldehyde polymeric condensates and said monomeric substituted phenols are provided as individual fine solid particles in an aqueous suspension and including the steps of coating said suspension on one side nolic-aldehyde polymeric condensates and monomeric substituted phenols are suspended in said suspension as premixed fine solid particles.

Claims

2. A process as defined in claim 1, wherein said phenolic-aldehyde polymeric condensates and said monomeric substituted phenols are provided as individual fine solid particles in an aqueous suspension and including the steps of coating said suspension on one side of a base sheet to form said recording sheet and drying the coated recording sheet.
3. A process as defined in claim 1, in which said coated layer has a smooth surface.
4. A process as defined in claim 2, including the step of maintaining the pH of said suspension within the range of from 6.0 to 11.0.
5. A process as defined in claim 2, wherein said phenolic-aldehyde polymeric condensates and monomeric substituted phenols are suspended in said suspension as premixed fine solid particles.
90. THE RESULTANT PRODUCT CAN PRODUCE AN EXCELLENT COLOR-FORMATION WHEN REACTIVE CONTACT AMOUNT THE COLOR-FORMING COMPONENTS IS CAUSED BY IMPARTING HEAT OR AN ULTRASONIC VIBRATING ENERGY.