US3260613A - Heat-sensitive sheet for thermographic copying - Google Patents

Heat-sensitive sheet for thermographic copying Download PDF

Info

Publication number
US3260613A
US3260613A US265337A US26533763A US3260613A US 3260613 A US3260613 A US 3260613A US 265337 A US265337 A US 265337A US 26533763 A US26533763 A US 26533763A US 3260613 A US3260613 A US 3260613A
Authority
US
United States
Prior art keywords
lead
heat
paper
copying
sheet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US265337A
Inventor
Edward C Otto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Interchemical Corp
Original Assignee
Interchemical Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Interchemical Corp filed Critical Interchemical Corp
Priority to US265337A priority Critical patent/US3260613A/en
Application granted granted Critical
Publication of US3260613A publication Critical patent/US3260613A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • B41M5/32—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers one component being a heavy metal compound, e.g. lead or iron
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
    • Y10S430/165—Thermal imaging composition
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
    • Y10T428/251—Mica

Definitions

  • This invention relates to copy sheets and to a method of making copies therewith. More particularly the invention relates to copy sheets for use in making copies by a thermographic technique wherein the image on the copy sheet is the result of a chemical change produced by localized heating in the image area.
  • thermocopying of typed or printed originals has become increasingly popular.
  • Thermographic copying involves placing the original in heat conductive relationship with a sheet of copy paper and then subjecting the original and copy sheet to intense irradiation of such character that the printed or type matter on the original absorbs that least a portion of the radiant energy thereby converting it into heat which causes the image of the original to be developed in the copy sheet.
  • the copy sheet must be constructed in such manner as to be capable of changing to a contrasting color when heated.
  • the thermographic copying process machines for carrying out the process and certain types .of heat-sensitive papers are described in numerour prior art patents, for instance, United States Patents 2,663,654-7; 2,710,263; 2,740,895-6.
  • the .heat induced image may be formed either by a physical change in the copy sheet or by a chemical reaction induced by the heat.
  • This invention is concerned with heat-sensitive sheets in which the image is formed as a result of a chemical reaction.
  • thermogra-phic copying paper in which image formation results from a chemical reaction is the copying paper described in U.S. Patent 2,663,657.
  • This paper has a coating of two materials that are reactive with each other to produce a dark colored product which forms the image.
  • the reactants are disperse as discrete particles in a binder. At least one of the reactants is fusible within the range of 60 to 120 C. Thus, when the coating is heated to a temperature within said range, the fusible reactant particles melt and flow into contact with the particles of the other reactant with the resultant reaction.
  • US. Patent 2,663,657 further states that the binder should be infusible within the 60 to 120 range in order to avoid undesirable sticking of the copying paper to contacting surfaces during copying.
  • thermographic copying paper of the chemically reactive type in which both of the reactants are infusible within the 60 to 120 C. range and which employs a binder which is fusible within the 60 to 120 C. range. Furthermore the use of the binder of this invention creates none of the problems of undesirable stickiness which eliminated the use of low melting binders in US. Patent No. 2,663,657
  • the paper of this invention may be generally described as a heat-sensitive copying sheet comprising a base sheet, preferably of infrared transparent paper, carrying a coating comprising individual dispersions of two reactants which are capable of reacting to form colored sulfides of heavy metal.
  • One of the reactants may be described as the heavy metal donor and the other reactant as the sulfide donor.
  • the reactants are of very low water solubility and preferably are substantially insoluble in water. Both reactants have fusion points greater than 120 C.
  • the reactants are dispersed in a binder which has a fusion point of from 60 to 120 C. Accordingly, the binder "Ice melts during the copying operation and carries the indivrdual dispersed particles of the reactants into contact with each other where they may react.
  • the heavy metal donor is preferably a lead salt, having a fusion point greater than C., lead hydroxide or a lead oxide compound.
  • the lead salts may be the salt of any acid except strong acids such as sulfuric, hydrochloric or nitric acids. Suitable lead salts include lead maleate, lead carbonate, lead formate and lead phosphate.
  • lead oxide is meant to include lead oxide containing compounds e.g., the commercially available compounds:
  • the sulfur donor is preferably a thiourea compound and most preferably a substituted thiourea having a fusion point above 120 C. and being substantially insoluble in water.
  • Two such substituted thioureas which are very suitable for the practice of this invention are monophenyl thiourea and diphenyl thiourea.
  • the binder is preferably a chlorinated paraflin wax containing at least 50% chloride and having a fusion point between 60 andl20. (It should be noted that in the present specification and claims, all proportions are by weight unless otherwise stated.) I have found such colorinated paraffin wax binders display stability or aging characteristics far superior to other binders having the requisite 60 to 120 C. fusion point. Representative of the binders having the requisite melting points which were tried were ethyl cellulose polymer, chlorinated natural rubber having a 67% chlorine content and polyamides formed by the condensation polymerization of dilinolenic acid and ethylene diamine.
  • binders produced papers which had a lower stability and a lower resistance to aging as compared to the papers of this invention.
  • the darkness of the image may be enhanced by the addition to the binder of small amounts of a wax which has a lower viscosity than the chlorinated paraffin wax.
  • Microcrystalline wax is an excellent additive for this purpose as is parafiin wax.
  • the wax additive preferably constitutes from 15% to 30% of the total binder weight.
  • a sufficient amount of the lead donor is used to provide from 1 to 4 sulfur atoms for each lead atom.
  • the reactants are applied to the substrate as dispersions in a volatile organic solvent solution of the binder.
  • the coating may be applied in a single application. However, as the reactants display some tendency to react with each other while dispersed in these solutions, the preferable technique is to apply the coating layer in two steps. One of the reactants dispersed in the binder solution is first applied after which the second reactant in the same binder solution is applied.
  • the resulting coating on the paper is uniform, has good adhesion to the paper and excellent strain and pressure resistance. In addition the paper has excellent resistance to aging. When subjected to the aforementioned accelerated aging test for 72 hours at 120 -F. and 97% relative humidity the paper still produces readable copies.
  • the sheet When exposed in the Thermo-Fax copying machine by either front or back printing techniques with an original, the sheet produces a clear copy in which the graphic matter is black against a white background.
  • Example 2 The following batches A and B are prepared separately by mixing on a ball mill in accordance with the procedure of Example 1. Batch A:
  • Chlorowax 70 Tribasic lead maleate monohydrate having the for- Parts by wt. 6.0
  • the two batches are then mixed and immediately coated on an infrared transparent base paper using a No. 3 Mayer coater.
  • the resulting coating is uniform, has good adhesion to the paper and excellent strain and pressure resistance.
  • the sheet When exposed, after drying, to the Thermo-Fax copying machine by either front or back printing methods with an original, the sheet produces a clear copy in which the graphic matter is dark brown against a white background.
  • Example 3 using the procedure of Example 1 which involves two steps in the application of the paper coating, a coated paper is produced from the following compositions:
  • Step 1 composition: Parts by wt. Chlorowax 70 6.0 Tribasic lead maleate monohydrate 7.0 Microcrystalline wax 1.5 Toluene 30.0
  • the resulting coated paper has all of the properties of the paper of Example 1 and in addition has greater heatsensitivity.
  • Example 4 using the 2 step procedure of Example 1. a coating is produced from the following compositions:
  • Step 1 composition: Parts by wt; Chlorowax 70 6.0 Tribasic lead maleate 7.0 Microcrystalline wax 1.5 Toluene 30.0
  • Step 2 composition: Chlorowax 70 7.0 Diphenyl thiourea 5.0
  • the resulting coated paper has all of the desirable properties of the paper of Example 1. 7
  • Example 6 using the 2 step procedure of Example 1; a coating is produced from the following compositions:
  • Step 1 composition: Parts by wt. Chlorowax 70 7.0 Lead hydroxide 5.0
  • Microcrystalline Wax Toluene 30.0 Step 2 composition: Chlorowax 70 7.0 Diphenyl thiourea 5.0 Toluene 30.0
  • the resulting coated paper has all of the desirable properties of the paper of Example 1.
  • Example 7 Example 7 is repeated using the same conditions, ingredients and proportions except that lead maleate is used in place of lead hydroxide. The results are the same as in Example 5.
  • Example 8--Example 5 is repeated using the same conditions, ingredients and proportions except that lead oxide is used in place of lead hydroxide. The results are the same as in Example 5.
  • Example 9.-Example 3 is repeated using the same ingredients, proportions and conditions except that in place of the Chlorowax 70 binder in the compositions of both step 1 and step 2, there is used a combination of 4.0 parts of Chlorowax 70 and 2 parts of Chlorowax 50 in each step.
  • Chlorowax 50 is chlorinated paraflin having a chlorine content of 50% and a molecular Weight of about 660.
  • the resulting paper had all of the desirable properties of the paper of Example 3 except that the paper of Example 3 had slightly better stability on accelerated aging.
  • Example 10.-Example 1 is repeated using the same ingredients, conditions and proportions except that, the second applied coating further includes 5 parts of mica.
  • the resulting paper has all of the desirable properties of the paper of Example 1.
  • a heat-sensitive copying sheet adapted, on being placed in heat-conductive relationship with a. graphic original having graphic representations highly absorbtive of infrared rays and on irradiation of said graphic original with infrared rays, to produce a copy of said graphic original, said copying sheet comprising a base sheet having thereon a coating comprising (A) a dispersion of a lead compound having a melting point above 120 C. selected from the group consisting of lead salts of maleic acid, lead carbonate, lead phosphite, lead formate, lead hydroxide and lead oxide and (B) a dispersion of phenyl substituted thiourea having a melting point above 120 C. in
  • (C) a binder comprising a major portion of chlorinated paraflin wax having a chloride content of at least 50% by weight and a melting point between 60 and 120 C.
  • binder further comprises microcrystalline Wax blended with the chlorinated paraffin wax.
  • a copying sheet according to claim 1 comprising a dispersion of tribasic lead maleate monohydrate and of monophenyl thiourea in a binder comprising a chlorinated paraflin wax having a chlorine content of about by weight.
  • a copying sheet according to claim 1 comprising a dispersion of tribasic lead maleate monohydrate and of monophenyl thiourea in a binder comprising a paraffin wax having a chlorine content of about 70% by weight and a microcrystalline wax.
  • the copying sheet of claim 13 further including a colorless filler having a melting point above C.

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)
  • Paper (AREA)

Description

July 12, 1966 E. c. OTTO 3,260,613
HEAT-SENSITIVE SHEET FOR THERMOGRAPHIC COPYING Filed March 15, 1963 DISPERSED PHENYL THIOUREA DISPERSED LEAD COMPOUND CHLORINATED PARAFFIN WAX BINDER United States Patent 3,260,613 HEAT-{SENSITIVE SHEET FOR THERMO- GRAPHIC COPYING Edward C. Otto, Brooklyn, N.Y., assignor to Interchemical Corporation, New York, N.Y., a corporatron of Ohio Filed Mar. 15, 1963, Ser. No. 265,337 14 Claims. (Cl. 117-36.9)
This invention relates to copy sheets and to a method of making copies therewith. More particularly the invention relates to copy sheets for use in making copies by a thermographic technique wherein the image on the copy sheet is the result of a chemical change produced by localized heating in the image area.
In recent years thermocopying of typed or printed originals has become increasingly popular. Thermographic copying involves placing the original in heat conductive relationship with a sheet of copy paper and then subjecting the original and copy sheet to intense irradiation of such character that the printed or type matter on the original absorbs that least a portion of the radiant energy thereby converting it into heat which causes the image of the original to be developed in the copy sheet. In such a process, it is apparent that the copy sheet must be constructed in such manner as to be capable of changing to a contrasting color when heated. The thermographic copying process machines for carrying out the process and certain types .of heat-sensitive papers are described in numerour prior art patents, for instance, United States Patents 2,663,654-7; 2,710,263; 2,740,895-6.
The .heat induced image may be formed either by a physical change in the copy sheet or by a chemical reaction induced by the heat. This invention is concerned with heat-sensitive sheets in which the image is formed as a result of a chemical reaction.
A typical thermogra-phic copying paper in which image formation results from a chemical reaction is the copying paper described in U.S. Patent 2,663,657. This paper has a coating of two materials that are reactive with each other to produce a dark colored product which forms the image. The reactants are disperse as discrete particles in a binder. At least one of the reactants is fusible within the range of 60 to 120 C. Thus, when the coating is heated to a temperature within said range, the fusible reactant particles melt and flow into contact with the particles of the other reactant with the resultant reaction. US. Patent 2,663,657 further states that the binder should be infusible within the 60 to 120 range in order to avoid undesirable sticking of the copying paper to contacting surfaces during copying.
I have now discovered a novel thermographic copying paper of the chemically reactive type in which both of the reactants are infusible within the 60 to 120 C. range and which employs a binder which is fusible within the 60 to 120 C. range. Furthermore the use of the binder of this invention creates none of the problems of undesirable stickiness which eliminated the use of low melting binders in US. Patent No. 2,663,657
The paper of this invention may be generally described as a heat-sensitive copying sheet comprising a base sheet, preferably of infrared transparent paper, carrying a coating comprising individual dispersions of two reactants which are capable of reacting to form colored sulfides of heavy metal. One of the reactants may be described as the heavy metal donor and the other reactant as the sulfide donor. The reactants are of very low water solubility and preferably are substantially insoluble in water. Both reactants have fusion points greater than 120 C. The reactants are dispersed in a binder which has a fusion point of from 60 to 120 C. Accordingly, the binder "Ice melts during the copying operation and carries the indivrdual dispersed particles of the reactants into contact with each other where they may react.
While other heavy metal salts, notably mercury, silver, cadmium, nickel, cobalt and tin have been used with adequate results in this invention, the heavy metal donor is preferably a lead salt, having a fusion point greater than C., lead hydroxide or a lead oxide compound. The lead salts may be the salt of any acid except strong acids such as sulfuric, hydrochloric or nitric acids. Suitable lead salts include lead maleate, lead carbonate, lead formate and lead phosphate. The term lead oxide is meant to include lead oxide containing compounds e.g., the commercially available compounds:
Lectro 7 8-tetrabasic lead fumarate,
4Pb0 -PbC- H (COO 2H O Tribase-tribasic lead sulfate,
3Pb0- PbSO -H O Dy-thaldibasic or lead phthalate,
The sulfur donor is preferably a thiourea compound and most preferably a substituted thiourea having a fusion point above 120 C. and being substantially insoluble in water. Two such substituted thioureas which are very suitable for the practice of this invention are monophenyl thiourea and diphenyl thiourea.
The binder is preferably a chlorinated paraflin wax containing at least 50% chloride and having a fusion point between 60 andl20. (It should be noted that in the present specification and claims, all proportions are by weight unless otherwise stated.) I have found such colorinated paraffin wax binders display stability or aging characteristics far superior to other binders having the requisite 60 to 120 C. fusion point. Representative of the binders having the requisite melting points which were tried were ethyl cellulose polymer, chlorinated natural rubber having a 67% chlorine content and polyamides formed by the condensation polymerization of dilinolenic acid and ethylene diamine. These binders produced papers which had a lower stability and a lower resistance to aging as compared to the papers of this invention. I have further found that, in some instances, where the images on copy are lighter than desired, the darkness of the image may be enhanced by the addition to the binder of small amounts of a wax which has a lower viscosity than the chlorinated paraffin wax. Microcrystalline wax is an excellent additive for this purpose as is parafiin wax. When used, the wax additive preferably constitutes from 15% to 30% of the total binder weight.
Preferably a sufficient amount of the lead donor is used to provide from 1 to 4 sulfur atoms for each lead atom. Preferably, from 0.2 to 2.0 parts of binder are used for each part of total reactants.
In preparing the paper, the reactants are applied to the substrate as dispersions in a volatile organic solvent solution of the binder. The coating may be applied in a single application. However, as the reactants display some tendency to react with each other while dispersed in these solutions, the preferable technique is to apply the coating layer in two steps. One of the reactants dispersed in the binder solution is first applied after which the second reactant in the same binder solution is applied. The
use of this technique also permits the manufacture of a formula C24H29Cl21) 7 Lead carbonate 8 Microcrystalline wax (M.P. about 90 C., Fisher- Johns method) 3 Toluene 15 It has been further found that in some instances even further freedom from tack may be obtained by the inclusion of a filler. Best results have been obtained using mica or calcium carbonate as fillers. However any other conventional colorless or white filler having a melting point above 120 C. may be used. When present, the filler preferably constitutes from 10 to 40% of the total binder present. Where the coating is applied in two applications, the filler is included preferably in the second layer applied so that it Will 'be predominantly in the upper part of the coating.
Then, 15 additional parts of toluene are added and the mixture is applied to an infrared transparent White paper at a coating thickness of 0.1 mil using a No. 3 Mayer rod. The coating is then permitted to dry at ambient temperature for 20 seconds.
The applied coating is then overcoated with a composition prepared by the same procedure as above containmg:
' Parts by Wt. Chlorowax 70 6 Monophenyl thiourea Microcrystalline wax (M.P. 90 C.) 1.5
Toluene The resulting coating on the paper is uniform, has good adhesion to the paper and excellent strain and pressure resistance. In addition the paper has excellent resistance to aging. When subjected to the aforementioned accelerated aging test for 72 hours at 120 -F. and 97% relative humidity the paper still produces readable copies.
When exposed in the Thermo-Fax copying machine by either front or back printing techniques with an original, the sheet produces a clear copy in which the graphic matter is black against a white background.
Example 2.The following batches A and B are prepared separately by mixing on a ball mill in accordance with the procedure of Example 1. Batch A:
Chlorowax 70 Tribasic lead maleate monohydrate having the for- Parts by wt. 6.0
Monophenyl thiourea 5.0 Microcrystalline wax 1.5 Toluene 30.0
The two batches are then mixed and immediately coated on an infrared transparent base paper using a No. 3 Mayer coater. The resulting coating is uniform, has good adhesion to the paper and excellent strain and pressure resistance. When exposed, after drying, to the Thermo-Fax copying machine by either front or back printing methods with an original, the sheet produces a clear copy in which the graphic matter is dark brown against a white background.
Example 3.Using the procedure of Example 1 which involves two steps in the application of the paper coating, a coated paper is produced from the following compositions:
Step 1 composition: Parts by wt. Chlorowax 70 6.0 Tribasic lead maleate monohydrate 7.0 Microcrystalline wax 1.5 Toluene 30.0
Step 2 composition:
Chlorowax 70 6.0 Monophenyl thiourea '5-.0 Microcrystalline wax 1.5 Toluene 30:0
The resulting coated paper has all of the properties of the paper of Example 1 and in addition has greater heatsensitivity.
Example 4.Using the 2 step procedure of Example 1. a coating is produced from the following compositions:
Step 1 composition: Parts by wt; Chlorowax 70 6.0 Tribasic lead maleate 7.0 Microcrystalline wax 1.5 Toluene 30.0
Step 2 composition: Chlorowax 70 7.0 Diphenyl thiourea 5.0
Toluene 30.0
Chlorowax 70 6.0 Monophenyl thiourea 5.0 1.5
Microcrystalline wax v Toluene 30.0
The resulting coated paper has all of the desirable properties of the paper of Example 1. 7
Example 6.Using the 2 step procedure of Example 1; a coating is produced from the following compositions:
Step 1 composition: Parts by wt. Chlorowax 70 7.0 Lead hydroxide 5.0
Microcrystalline Wax Toluene 30.0 Step 2 composition: Chlorowax 70 7.0 Diphenyl thiourea 5.0 Toluene 30.0
The resulting coated paper has all of the desirable properties of the paper of Example 1.
Example 7 .-Example 5 is repeated using the same conditions, ingredients and proportions except that lead maleate is used in place of lead hydroxide. The results are the same as in Example 5.
Example 8.--Example 5 is repeated using the same conditions, ingredients and proportions except that lead oxide is used in place of lead hydroxide. The results are the same as in Example 5.
Example 9.-Example 3 is repeated using the same ingredients, proportions and conditions except that in place of the Chlorowax 70 binder in the compositions of both step 1 and step 2, there is used a combination of 4.0 parts of Chlorowax 70 and 2 parts of Chlorowax 50 in each step. (Chlorowax 50 is chlorinated paraflin having a chlorine content of 50% and a molecular Weight of about 660.) The resulting paper had all of the desirable properties of the paper of Example 3 except that the paper of Example 3 had slightly better stability on accelerated aging.
Example 10.-Example 1 is repeated using the same ingredients, conditions and proportions except that, the second applied coating further includes 5 parts of mica. The resulting paper has all of the desirable properties of the paper of Example 1.
While there have been described what is at present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.
What is claimed is 1. A heat-sensitive copying sheet adapted, on being placed in heat-conductive relationship with a. graphic original having graphic representations highly absorbtive of infrared rays and on irradiation of said graphic original with infrared rays, to produce a copy of said graphic original, said copying sheet comprising a base sheet having thereon a coating comprising (A) a dispersion of a lead compound having a melting point above 120 C. selected from the group consisting of lead salts of maleic acid, lead carbonate, lead phosphite, lead formate, lead hydroxide and lead oxide and (B) a dispersion of phenyl substituted thiourea having a melting point above 120 C. in
(C) a binder comprising a major portion of chlorinated paraflin wax having a chloride content of at least 50% by weight and a melting point between 60 and 120 C.
2. The copying sheet of claim 1 wherein said lead compound is a lead salt of maleic acid.
3. The copy sheet of claim 2 wherein said lead salt is tribasic lead maleate monohydrate.
4. The copying sheet of claim 1 wherein said lead compound is lead carbonate.
5. The copying sheet of claim 1 wherein said lead compound is lead oxide.
6. The copying sheet of claim 1 wherein said lead compound is lead phosphite.
7. The copying sheet of claim 1 wherein said thiourea is monophenyl thiourea.
8. The copying sheet of claim 1 wherein said thiourea is diphenyl thiourea.
9. The copying sheet of claim 1 wherein the binder further comprises microcrystalline Wax blended with the chlorinated paraffin wax.
10. The heat-sensitive copying sheet of claim 1 wherein the dispersion of the lead compound is situated predominantly in the lower half of the coating layer and the dispersion of the phenyl substituted thiourea is situated predominantly in the top half of the coating layer.
11. A copying sheet according to claim 1 comprising a dispersion of tribasic lead maleate monohydrate and of monophenyl thiourea in a binder comprising a chlorinated paraflin wax having a chlorine content of about by weight.
12. A copying sheet according to claim 1 comprising a dispersion of tribasic lead maleate monohydrate and of monophenyl thiourea in a binder comprising a paraffin wax having a chlorine content of about 70% by weight and a microcrystalline wax.
13. The copying sheet of claim 1, further including a colorless filler having a melting point above C.
14. The copying sheet of claim 13 wherein said filler is mica.
References Cited by the Examiner UNITED STATES PATENTS 2,625,494 1/ 1953 Morrison 11736.8 2,916,395 12/1959 Owen 11736.8 2,967,784 1/ 1961 Newman et al 11736.8 2,999,035 9/1961 Sahler 117-36.8 3,080,254 3/1963 Grant 1l7-36.8 3,107,174 10/ 1963 Wartman 117-368 3,111,423 11/1963 OStie 117-369 MURRAY KATZ, Primary Examiner.
WILLIAM D. MARTIN, Examiner.

Claims (1)

1. A HEAT-SENSITIVE COPYING SHEET ADAPTED, ON BEING PLACED IN HEAT-CONDUCTIVE RELATIONSHIP WITH A GRAPHIC ORIGINAL HAVING GRAPHIC REPRESENTATIONS HIGHLY ABSORBTIVE TO INFRARED RAYS AND ON IRRADIATION OF SAID GRAPHIC ORIGINAL WITH INFRARED RAYS, TO PRODUCE A COPY OF SAID GRAPHIC ORIGINAL, SAID COPYING SHEET COMPRISING A BASE SHEET HAVING THEREON A COATING COMPRISING (A) A DISPERSION OF A LEAD COMPOND HAVING A MELTING POINT ABOVE 120*C. SELECTED FROM THE GROUP CONSISTING OF LEAD SALTS SALTS OF MALEIC ACID, LEAD CARBONATE, LEAD PHOSPHITE, LEAD FORMATE, LEAD HYDROXIDE AND LEAD OXIDE AND (B) A DISPERSION OF PHENYL SUBSTITUTED THIOUREA HAVING A MELTING POINT ABOVE 120*C. IN (C) A BINDER COMPRISING A MAJOR PORTION OF CHLORINATED PARAFFIN WAX HAVING A CHLORIDE CONTENT OF AT LEAST 50% BY WEIGHT AND A MELTING POINT BETWEEN 60* AND 120*C.
US265337A 1963-03-15 1963-03-15 Heat-sensitive sheet for thermographic copying Expired - Lifetime US3260613A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US265337A US3260613A (en) 1963-03-15 1963-03-15 Heat-sensitive sheet for thermographic copying

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US265337A US3260613A (en) 1963-03-15 1963-03-15 Heat-sensitive sheet for thermographic copying

Publications (1)

Publication Number Publication Date
US3260613A true US3260613A (en) 1966-07-12

Family

ID=23010024

Family Applications (1)

Application Number Title Priority Date Filing Date
US265337A Expired - Lifetime US3260613A (en) 1963-03-15 1963-03-15 Heat-sensitive sheet for thermographic copying

Country Status (1)

Country Link
US (1) US3260613A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3772052A (en) * 1970-09-28 1973-11-13 Fuji Photo Film Co Ltd Recording sheet and color developer therefor
JPS49115554A (en) * 1973-03-08 1974-11-05
US3934070A (en) * 1970-10-23 1976-01-20 Fuji Photo Film Co., Ltd. Recording sheet and color developer therefor
US4050945A (en) * 1974-07-08 1977-09-27 Yoshio Suzuki Heat-sensitive color-producing compositions and articles using same
WO1992020526A1 (en) * 1991-05-16 1992-11-26 Raychem Limited Laser marking of fluoropolymers

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2625494A (en) * 1948-05-05 1953-01-13 Morrison Montford Heat-sensitive recording element
US2916395A (en) * 1958-07-21 1959-12-08 Minnesota Mining & Mfg Heat-sensitive copy-paper
US2967784A (en) * 1958-05-02 1961-01-10 Columbia Ribbon Carbon Mfg Thermographic copying paper
US2999035A (en) * 1958-03-08 1961-09-05 Keuffel & Esser Co Heat sensitive reproduction sheet, method of making and method of using
US3080254A (en) * 1959-10-26 1963-03-05 Minnesota Mining & Mfg Heat-sensitive copying-paper
US3107174A (en) * 1958-10-20 1963-10-15 Minnesota Mining & Mfg Heat sensitive copy sheet and method of making
US3111423A (en) * 1960-05-16 1963-11-19 Minnesota Mining & Mfg Heat-sensitive copy-sheet

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2625494A (en) * 1948-05-05 1953-01-13 Morrison Montford Heat-sensitive recording element
US2999035A (en) * 1958-03-08 1961-09-05 Keuffel & Esser Co Heat sensitive reproduction sheet, method of making and method of using
US2967784A (en) * 1958-05-02 1961-01-10 Columbia Ribbon Carbon Mfg Thermographic copying paper
US2916395A (en) * 1958-07-21 1959-12-08 Minnesota Mining & Mfg Heat-sensitive copy-paper
US3107174A (en) * 1958-10-20 1963-10-15 Minnesota Mining & Mfg Heat sensitive copy sheet and method of making
US3080254A (en) * 1959-10-26 1963-03-05 Minnesota Mining & Mfg Heat-sensitive copying-paper
US3111423A (en) * 1960-05-16 1963-11-19 Minnesota Mining & Mfg Heat-sensitive copy-sheet

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3772052A (en) * 1970-09-28 1973-11-13 Fuji Photo Film Co Ltd Recording sheet and color developer therefor
US3934070A (en) * 1970-10-23 1976-01-20 Fuji Photo Film Co., Ltd. Recording sheet and color developer therefor
JPS49115554A (en) * 1973-03-08 1974-11-05
JPS5127599B2 (en) * 1973-03-08 1976-08-13
US4050945A (en) * 1974-07-08 1977-09-27 Yoshio Suzuki Heat-sensitive color-producing compositions and articles using same
WO1992020526A1 (en) * 1991-05-16 1992-11-26 Raychem Limited Laser marking of fluoropolymers

Similar Documents

Publication Publication Date Title
US2663657A (en) Heat-sensitive copying paper
US2612480A (en) Printing ink
US2872340A (en) Transfer element and method of making the same
EP0005976B1 (en) Process for preparing zinc-modified phenol-aldehyde novolak resins and heat- or pressure-sensitive recording material carrying a resin so prepared
US2618574A (en) Surfaces of plastics coated with ink containing a chlorinated or chlorosulfonated polymer of ethylene
US3260613A (en) Heat-sensitive sheet for thermographic copying
US3170809A (en) Transfer sheet and process of making
US3312564A (en) Transfer sheet, process of making and using
US4431769A (en) Binder composition for paper-coating materials
US5017428A (en) Multiple impression thermal transfer ribbon
US3461092A (en) Solid particulate printing ink composition and process for producing same
US3157526A (en) Thermo-sensitive copy sheet and method of making
US3129109A (en) Heat-sensitive copy-sheet
US3028255A (en) Heat-sensitive copy-sheet
JPS6025786A (en) Heat transfer material
US4055704A (en) Typing correction paper
US4442179A (en) Heat-sensitive recording paper
US3539376A (en) Method of making copying paper
US3238047A (en) Data processing media
US3261023A (en) Thermographic recording process wherein the heat-sensitive sheet is used in plural processes
US3065099A (en) Pressure sensitive transfer sheet
JPH02145394A (en) Thermal transfer sheet
JPH0257389A (en) Heat transfer sheet
JPH01176587A (en) Thermal transfer sheet
US3240613A (en) Data processing media