Abstract: A thermal recording medium good in recording sensitivity and recording stability comprising a metal thin layer, a heat sensitive softening layer placed in contact with said metal thin layer, a contrasting layer placed in contact with said heat sensitive softening layer or said metal thin layer and having a visual contrast to said metal thin layer, and a heat sensitive color forming layer placed in contact with said heat sensitive softening layer or said metal thin layer on the side of said metal thin layer opposite to the side where the contrasting layer is positioned.
Abstract: Thermosensitive linerless labels (either thermal labels or thermal transfer labels) which can be used with food products contain a pressure sensitive adhesive covering one face of a substrate having a thermosensitive layer on the opposite face, and a release coat covering the thermosensitive layer. The release coating is preferably applied directly to the thermosensitive layer, and preferably is prepared by application and then drying of a formulation containing between about 5-25 parts chromium pentahydroxy (tetradecanoato) di-, and about 75-95% water or alcohol. Alternatively, the release coating may be a UV curable silicone with about 1-3% by weight photoinitiator. After the coatings are applied, the stock is dried in a manner that will not adversely affect the thermosensitive layer, e.g. by ultraviolet rays, or air drying at a temperature of less than 150.degree. F. A web comprising the substrate may be slit into individual rolls, and perfing or die cutting is practiced to form individual labels.
Abstract: A heat-sensitive recording material comprising a support having thereon a color-developing layer and at least one UV-absorbing layer with a light-transmittance of 70% or less at 400 nm, 5% or less at 370 nm, and 70% or more for entire visible light range, is disclosed.
Type:
Grant
Filed:
November 21, 1991
Date of Patent:
February 15, 1994
Assignee:
Fuji Photo Film Co., Ltd.
Inventors:
Naotaka Wachi, Ken Iwakura, Kensuke Ikeda, Katsuya Takemasa
Abstract: The present invention relates to a heat-sensitive recording medium which is excellent in dot-reproducibility and in adhesion between a support and a heat-sensitive recording layer provided thereon. The present recording medium comprises a synthetic-resin support, an ionomer-resin layer on the support, and a heat-sensitive recording layer provided on the ionomer-resin layer.
Abstract: A two sided thermal printing system includes a sheet which is specially coated on both sides for two sided thermal printing. A first side of the sheet has a dye receiving first coating for heat flowable dye transfer thermal printing via a dye bearing web in a transfer printing step. An opposing second side of the sheet has a second coating containing a heat activated dye material for forming, in situ, a dye image by direct thermal printing in an in situ printing step. The sheet portion, exclusive of the second coating, has a sufficient thickness and thermal resistance for inhibiting heat transfer therethrough during the transfer printing step on the first side to prevent activation of the dye material in the second coating on the second side.
Abstract: A reversible thermosensitive recording material is composed of a support and a reversible thermosensitive recording layer formed thereon. The reversible thermosensitive recording layer is composed of a matrix resin, such as polyvinyl chloride or vinyl chloride copolymer, and an organic low-molecular-weight material dispersed in the form of finely-divided particles in the matrix resin, with the weight percentage Y of the vinyl chloride repeat in the matrix resin and the average polymerization degree X of the matrix resin satisfying the relationship:-0.68 log X+3.794.ltoreq.log Y.ltoreq.-0.215 log X+2.66.
Abstract: This invention relates to the use of a compound containing at least two epoxide moieties in the protective topcoat layer and/or in a layer on top of the protective topcoat layer of certain thermographic recording films to reduce gouging and streaking of the printed image film and to reduce head build-up on the thermal printhead.
Type:
Grant
Filed:
January 27, 1993
Date of Patent:
January 11, 1994
Assignee:
Polaroid Corporation
Inventors:
Edward J. Dombrowski, John R. McPherson, Sr.
Abstract: A reversible thermosensitive recording material composed of a support, an undercoat layer formed on the support, and a reversible thermosensitive recording layer formed on the undercoat layer, capable of reversibly assuming a transparent state and a white opaque state depending on the temperature thereof, the undercoat layer having at least one colored portion and at least one light reflecting portion.
Abstract: The present invention provides a heat sensitive recording material comprising a heat sensitive recording layer formed on a substrate and containing a color former and a color developer reactive with the color former, an intermediate layer formed on the recording layer and containing a water-soluble resin or water-dispersible resin, and an overcoat layer formed on the intermediate layer and containing a resin curable with an ionizing radiation, the heat sensitive recording material being characterized in that the color developer comprises at least one of a salicylic acid derivative represented by the following formula (1) or formula (2) and polyvalent metal salt of the derivative ##STR1## wherein Ar, Q, A, R, X, Y, m and n are defined in the specification.
Abstract: The reversible heat-sensitive recording medium having a heat-sensitive recording layer capable of reversibly changing the transparency thereof with organic low molecular substances dispersed in an organic macromolecular resin provided on a support is characterized by using at least one long chain alkyl-containing compound having a melting point of 50.degree.-100.degree. C. and at least one saturated aliphatic bisamide having a melting point of not less than 110.degree. C. as the organic low molecular substance in a ratio of 98:2 to 80:20. A plasticizer may be contained in the organic macromolecular resin in a ratio of 1 to 10% by weight, based on the total solid of the heat-sensitive recording layer.
Abstract: The present invention provides a heat sensitive recording material comprising a substrate, a recording layer formed over the substrate and containing a colorless or light-colored basic dye and a color acceptor, and a protective layer formed over the recording layer, the recording material being characterized in that microcapsules having an ultraviolet absorber enclosed therein and having substantially no color forming ability are incorporated in the protective layer.Further, the present invention provides microcapsules having an ultraviolet absorber and as required an organic solvent enclosed therein, which have capsule wall film of synthetic resin and mean particle size of 0.1 to 3 .mu.m.
Abstract: A recording material comprising a thermosensitive recording layer (B) or a thermal dye transfer type image receiving layer (B') laminated on a surface layer (b) of a support (A), wherein the support (A) comprises the surface layer (b) comprising a uniaxially stretched thermoplastic resin film laminated onto a base layer (a), wherein the base layer (a) comprises a biaxially stretched film of a thermoplastic resin containing 10 to 45% by weight of an inorganic fine powder, and wherein said support (A) satisfies conditions (1) to (3):(1) the surface layer (b) of the support (A) comprises at least two layers: an outer layer (b.sup.1) comprising a uniaxially stretched film of a thermoplastic resin containing 0 to 30% by weight of an inorganic fine powder; and an inner layer (b.sup.2) comprising a uniaxially stretched film of a thermoplastic resin containing 30 to 80% by weight of an inorganic fine powder, wherein the thickness of the outer layer (b.sup.
Abstract: A heat-sensitive recording material excelled in surface gloss and printing concentration is disclosed.The disclosed heat-sensitive recording material with a heat-sensitive color-developing layer formed on a supporting member features provision on the surface of the heat-sensitive color-developing layer of a protective coating containing crosslinked microfine particles (B) having substantially no glass transition temperature, 0.5 .mu.m or less in mean particle size and 0.05 or less in the difference in refractive index from the solid content of aqueous resin despersion which are obtainable by emulsion-polymerizing vinyl-containing monomers containing 15 weight % or more of polymeric multifunctional monomers together with the aqueous resin dispersion (A).
Abstract: A thermosensitive recording material having a support and a thermosensitive coloring layer formed on the support, which thermosensitive coloring layer includes at least a first thermosensitive coloring layer containing at least one leuco dye having formula (I), (II) or (III) and a color developer capable of inducing color formation in the leuco dye under application of heat thereto, and a second thermosensitive coloring layer containing at least one leuco dye having formula (IV) and a color developer capable of inducing color formation in the leuco dye under application of heat thereto. The leuco dye for use in the first thermosensitive coloring layer has the absorption intensity in the near infrared region, and the leuco dye for use in the second thermosensitive coloring layer has the absorption intensity in the visible spectrum.
Abstract: A heat-sensitive recording composition comprising agglomerates which comprise an aromatic isocyanate compound, an imino compound and a sensitizer and have an average diameter of 2-30 .mu.m; and a process for producing the composition are disclosed. This heat-sensitive recording composition is excellent in heat response and high in sensitivity. From the point of image stability, the agglomerates are preferably contained in microcapsules together with a polymer.
Abstract: A thermal vellum medium includes a wood pulp based substrate having a thermal layer, comprising a heat-sensitive, image-forming material disposed on one side thereof and a silicone layer impregnated into an opposite side of the substrate.
Abstract: The heat-sensitive recording material is prepared by forming on a support successively a heat-sensitive recording layer containing a color former and a color developer which forms a color by reacting with the color former, an intermediate layer obtained by coating an aqueous solution or aqueous dispersion of a resin, and an overcoat layer containing a ionizing radiation curable resin, and then irradiating an ionizing radiation. The overcoat layer contains a silicone surface active agent and a low molecular weight polyolefin resin microball. The heat-sensitive recording material is excellent in recording runnability and printability as well as in color density of the recorded images and image-retainability.
Abstract: A heat-sensitive recording material having an improved color image-forming property and an enhanced gloss and resistance to water, oily substances and plasticizers, is provided with a heat-sensitive color-forming layer formed on a substrate surface and comprising a substantially colorless dye precursor, a color-developing agent and a binder; an intermediate layer formed on the color-forming layer and comprising a hydrophilic polymeric material and a pigment; a glossy surface layer formed on the intermediate layer and comprising a hydrophobic polymeric material having a glass transition point of 60.degree. C. or more, and a lubricant; and optionally, an additional intermediate layer formed between the color-forming layer and the intermediate layer and comprising at least one member selected from hydrophilic polymeric materials and hydrophobic polymeric materials.
Abstract: Structures for items such as promotional materials, game pieces, lottery tickets, security documents and other articles, which feature one or more thermal reactive layers that are activated by heat from a hidden image formed of infrared sensitive, heat generating material such as carbon black preprinted under the thermal reactive layers during manufacture. The thermal reactive layers permit transmission of radiant energy such as infrared to the heat generating, hidden layers. The heated image conducts heat to the thermal reactive layers which employ a coloring agent and a developer which, when exposed to the heat, react or act in concert in order to form a corresponding image on the face of the item.
Type:
Grant
Filed:
October 4, 1991
Date of Patent:
August 10, 1993
Assignee:
Dittler Brothers, Incorporated
Inventors:
Byrne E. Heninger, Donna C. Stimpson, Stephen M. Ems
Abstract: A thermosensitive recording material is composed of a support, an undercoat layer formed on the support, which is essentially composed of spherical-void plastic particles having an average particle diameter of 2 to 20 .mu.m and a voidage of 80% or more, and a thermosensitive coloring layer formed on the undercoat layer, which contains a leuco dye and a color developer capable of inducing color formation in the leuco dye upon application of heat thereto.
Abstract: A thermosensitive recording material is composed of a support, a thermosensitive coloring layer capable of inducing color formation upon application of heat thereto, formed on the support, and an overcoat layer formed on the thermosensitive coloring layer, the overcoat layer being essentially composed of a resin component which is crosslinked by a glycidylamine compound serving as a crosslinking agent for the resin component. A coating liquid for the formation of the overcoat layer is essentially composed of the resin component and the glycidylamine compound.
Abstract: Disclosed is a carbonless paper set having at least two sheets, wherein a first sheet comprises paper coated on one surface with a color former and a second sheet comprises paper coated on one surface with a color developer, and wherein at least one of the sheets contains an oleophilic pigment filler material on the surface of the sheet opposite to that coated with the color former or color developer.
Abstract: This invention relates to a heat-sensitive recording material. More particularly, this invention relates to a heat-sensitive recording material including a solvent-resistant and friction-reducing protective layer useful in the manufacture of adhesive-backed heat-sensitive labels and other thermally sensitive paper stock used in printers and facsimile equipment. The protective layer is non-acidic and has an improved resistance to background discoloration.
Abstract: A heat-sensitive recording material wherein a copolymer emulsion is employed, the copolymer emulsion being obtained by copolymerizing a monomer component which comprises (meth)acrylamide and an optional unsaturated monomer component copolymerizable with (meth)acrylamide in the presence of a seed emulsion serving as a nucleating particle. In the heat-sensitive recording material, the intermediate layer, the heat-sensitive recording layer or the protective layer comprises the copolymer emulsion. The recordinq layer and the resulting recorded images of such a heat-sensitive recording material have sufficient durability (such as water resistance, heat resistance, resistance to plasticizers and resistance to solvents) and the resistance to heat softening of the protective layer. The heat-sensitive recording material can be produced through easy process control and is excellent in color developing sensitivity.
Abstract: A coated resin film having excellent offset printability is described, which comprises a polyolefin resin film base material layer having formed on both the surfaces thereof a solvent permeation preventing layer for preventing the permeation of a solvent in offset printing ink compositions and further having formed on one or both the surfaces of the solvent permeation preventing layers a coating agent layer.
Abstract: A heat-sensitive stencil sheet is disclosed, which comprises a porous sheet having on one side thereof at least an adhesive layer and a thermoplastic resin film layer in this order, wherein at least one of the layers constituting said stencil sheet contains a heat-sensitive color-forming material. The layer containing the heat-sensitive color-forming material develops a color on thermal perforation to visualize the perforated image so that a printing ink, particularly plural inks of different color, can be easily applied to the stencil sheet in proper positions in proper quantities.
Abstract: This invention provides transparent thermographic recording films which exhibit good anti-stick properties, are scratch resistant and substantailly craze-free. The thermographic recording films comprise a transparent support carrying (a) a dye image-forming system comprising a di- or triarylmethane thiolactone dye precursor, an organic silver salt, a heat-fusible organic acidic material, and polyvinylbutyral as the binder; and, (b) a protective topcoat layer positioned above said dye image-forming system and comprising a water-insoluble polymeric binder, a mixture of at least two colloidal silicas having different average particle diameters in the proportion, by weight, of 1 part of silica having an average diameter of 50 nm or smaller and 0.3 to 1 part of silica particles having an average diameter no more than 40% of the larger sized silica particles, the ratio of total silica to binder being at least 3 parts per weight silica to 1 part per weight binder.
Abstract: A support for a dye transfer type thermosensitive printing sheet is disclosed, which comprises a porous film base having a biaxially stretched film of a thermoplastic resin containing an inorganic fine powder having adhered thereon a thermoplastic resin film having a centerline-average roughness of not more than 0.5 .mu.m as a surface layer on which a dye transfer type thermosensitive printing layer is to be provided, said surface layer having a thickness of from 0.3 to 1.5 .mu.m and a Bekk's smoothness of from 2500 to 7000 seconds, and said support having an opacity of not less than 70%, a density of not more than 0.91 g/cm.sup.3, and a compression ratio of from 15 to 35% under a stress of 32 kg/cm.sup.2. A dye transfer type thermosensitive printing sheet using the support of the invention has excellent surface smoothness and exhibits considerable compressibility and, therefore, shows improved adhesion or contact with a printing head to form an image rich in gradation.
Abstract: A heat-sensitive recording material having a superior resistance against water, plasticizers, and oily substances, is provided with a heat-sensitive color-forming layer formed on a surface of a substrate sheet and comprising a dye precursor, a color-developing agent, and a binder; and a protecting layer formed on the heat-sensitive color-forming layer and comprising (A) a polyvinylalcohol resin, (B) a water-soluble cross-linking agent, (C) at least one organic boron-containing polymer of the formula (I): ##STR1## and optionally (D) an acetoacetylated polyvinylalcohol resin.
Abstract: A thermosensitive recording material being composed of a support; a thermosensitive coloring layer, formed on the support, which contains a leuco dye and a color developer capable of inducing color formation in the leuco dye upon application of heat thereto; an overcoat layer, formed on the thermosensitive coloring layer, which contains a first resin component crosslinked by a first crosslinking agent; and a backcoat layer, formed on the back side of the support opposite to the thermosensitive coloring layer, which contains a second resin component crosslinked by a second crosslinking agent, with at least the first resin component being different from the second resin component or the first crosslinking agent being different from the second crosslinking agent.
Abstract: A thermosensitive stencil paper is composed of a substrate and a thermoplastic resin film formed thereon, which thermoplastic resin film has projections in the surface portion thereof, with a printing roughness (R.sub.p) of 2.2 to 5.0 .mu.m, which is a physical quantity proportional to the average depth of the depressions in the surface portion thereof pressed against a standard surface.
Abstract: A thermosensitive recording material is composed of a support, a thermosensitive coloring layer capable of inducing color formation upon application of heat thereto, formed on the support, and a protective layer including a resin and a filler formed on the thermosensitive coloring layer, the filler containing aluminum hydroxide or/and aluminum oxide particles, having a volume mean diameter of 1 .mu.m or less, with the amount of the particles with a diameter of 4 .mu.m or less being 90 vol. % or more in the entire particles.
Abstract: A heat-sensitive recording material which has a high recording density, ensures recorded images of high quality and allows printing on the reverse side. A base paper for the recording material is subjected to multilayer paper making by means of a paper machine having a multilayer head box. The surface layer of the base paper has a bulk density of below 0.85 g/cu. cm and a printing smoothness of above 15% (pressure: 20 kg/sq. cm) as measured by means of a printing smoothness tester.
Abstract: An extracted and isolated soy protein polymer is used for prevention of premature coloration in CFB pressure-sensitive copying paper which is neutral- or alkaline-sized with an alkyl ketene dimer and which utilizes an acid clay color developer composition. The soy protein polymer may be carried by the base paper, e.g. as a result of size press or size bath application, or may be present in the microcapsule coating.
Abstract: In a heat-sensitive recording paper having a heat-sensitive color-forming layer formed on substrate paper, said substrate paper is impregnated with pigment particles in its surface and said pigment particles are made to present between surface fibers or said substrate paper for the purpose of providing high sensitivity without causing any undesired transfer of tailings to the thermal head.
Abstract: A subcoat of plastic pigment particles and a binder is provided beneath the microcapsule coating of otherwise conventional pressure-sensitive copying paper of the CB or CFB type. The plastic pigment particles may be hollow or solid. Inorganic pigment particles are preferably also present in the subcoat. The binder may be a mixture of styrene/butadiene latex and polyvinyl alcohol. The subcoat typically has a coatweight of 3 to 6 g m.sup.-2. The presence of the plastic pigment subcoat improves copying intensity, or permits a desired given copy intensity to be obtained at a lower microcapsule coatweight.
Abstract: A reversible thermosensitive recording material is composed of a support and a reversible thermosensitive recording layer formed on the support. The reversible thermosensitive recording layer includes a matrix resin and an organic low-molecular-weight material dispersed in the matrix resin, and has a temperature-dependent transparency. The matrix resin includes a resin component having a glass transition temperature of 90.degree. C. or more.
Abstract: A thermosensitive recording material comprising a substrate and a thermosensitive coloring layer, formed thereon, which comprises a leuco dye; at least one color developer selected from the group consisting of 1,5-bis(4-hydroxyphenylthio)-3-oxapentane and 1,7-bis(4-hydroxyphenylthio)-3,5-dioxapentane; and an isocyanuric acid derivative of the formula (I): ##STR1## wherein R.sup.1, R.sup.3, R.sup.4 and R.sup.5 independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms, provided that at least either R.sup.1 or R.sup.3 represents an alkyl group having 1 to 4 carbon atoms; and R.sup.2 represents --C.sub.n H.sub.2n OH in which n is an integer of 0 to 4.
Abstract: A thermal printing medium having high mechanical strength, and a label and tag incorporating such a thermal printing medium is disclosed. In additional to high mechanical strength, the thermal printing medium of the present invention provides for excellent printing density and reslution, for which reason the medium is very applicable to bar codes and the like. The thermal printing medium which includes a multilayer structure consisting of a support substrate comprised of polyolefin type cross-laminate film; a thermal developing layer over the above mentioned under layer, comprised chiefly of colorless or lightly colored leuco-type dye and color developer agent; and a protective layer over the above mentioned thermal developing layer.
Abstract: A thermosensitive recording paper comprising a support sheet and a thermosensitive coloring layer formed thereon, which support sheet comprises needle-leaf tree pulp in an amount ratio of 10 to 50 wt. % of the absolute dry weight of the support sheet, with the maximum length of the fibers in the needle-leaf tree pulp being 4 mm or less.
Abstract: Disclosed is a heat-sensitive recording material useful in the manufacture of thermal paper and thermal labels. The material comprises a cellulosic or other suitable substrate, a thermally imprintable color-producing layer, and a protective layer over the color-producing layer. It may also include a second protective layer and/or a pressure-sensitive adhesive layer, on the surface of the substrate opposite from the color-producing layer, and a releasable liner covering the adhesive layer. The color-producing layer includes a basic, acid-neutralizing agent for both reducing background discoloration during manufacturing and increasing image definition. The protective layer comprises a cross-linked binder and fluorochemical surfactant-treated hydrocarbon or fluorocarbon particles as a friction reducing material.
Abstract: A thermosensitive recording material comprising a support, an intermediate layer including a foamed portion with minute voids on the support, and a thermosensitive coloring layer formed on the intermediate layer is disclosed, which is particularly improved in such a manner that the voidage of the upper portion of the intermediate layer close to the thermosensitive coloring layer is smaller than the voidage of the lower portion of the intermediate layer close to the support, or the voidage of the intermediate layer is increased from the upper portion thereof towards the lower portion thereof.
Abstract: Acid sized carbonless base paper incorporating a sulphate based filler, particularly calcium sulphate, is less base reactive than otherwise similar paper made using conventional clay (kaolin) fillers. Carbonless paper, particularly CB paper, made from such base is less susceptible to undesired discoloration arising from base reactivity.
Abstract: Disclosed are a water-sensitive coloring sheet comprising:(a) a substrate and(b) a water-sensitive coloring layer containing a colorless or pale-colored basic dye, a color developing material capable of forming a color on contact with the dye, a densensitizer and a binder, and a method for forming colored image on such water-sensitive coloring sheet by application of water.
Abstract: A thermosensitive recording material which comprises a support having a low Streckigt sizing degree, an undercoat layer comprising an oil absorbable pigment and a carboxymethyl cellulose, and a thermosensitive recording layer coated on the undercoat layer.The thermosensitive recording material of this invention can be used in a high speed recording system, since it has a high sensitivity, a high image quality and a low capacity to adhere stain to a thermal head, and these advantages can be improved further by adding an appropriate amount of paraffin wax to the undercoat layer. The thermosensitive recording material can be produced economically because a low cost material having a low Steckigt degree can be used as the support.
Abstract: A thermal transfer ribbon has a substrate, an undercoating which contains thermal reactive materials and leuco dyes, and a thermal transfer coating applied on the undercoating and which contains a mixture of a wax emulsion and a sensible material, the undercoating assiting the transfer of color images of an improved intensity and sharpness to a receiving medium upon the application of heat to the ribbon. The invention also covers incorporation of the leuco dye and a reactant in the functional coating to intensify the transferred image, with or without the presence of sensible materials such as iron oxide or fluroescent dye, to improve the sharpness and the scratch and smear resistance of the transferred image. An alternative to the two coatings is a single coating which includes pigments with sensing characteristics, thermal reactive material, and transfer agents to obtain an improved intensity image.
Abstract: A heat-sensitive recording material comprising a substrate, an intermediate layer disposed on said substrate and a heat sensitive recording layer disposed on said intermediate layer, characterized in that said intermediate layer contains a pigment of 80 cc/100 g or more in oil absorption as the main constituent and an alkaline pigment of 8 or more in PH value in an amount of 0.1 to 25% by weight on the total amount of the pigments contained in said intermediate layer.
Abstract: A support for a thermosensitive recording material comprising a surface layer of a thermoplastic resin film having a center line average roughness of 0.6 .mu.m or less laminated on the surface of a porous film base material of a biaxially stretched film of a thermoplastic resin containing an inorganic fine powder, wherein the properties of said support meet the following conditions (a) to (c);(a) the thickness of the surface layer is from 0.3 to 2.0 .mu.m and the Bekk smoothness of the surface layer is from 1,000 to 8,000 seconds,(b) the opacity of the support is at least 70%, the density of the support is 0.91 g/cm.sup.3 or less, and the compression ratio of the support under a stress of 32 kg/cm.sup.2 is from 15 to 35%, and(c) the coefficient of thermal shrinkage at 120.degree. C. for 30 minutes is 2.5% or less in the longitudinal direction and is 2.0% or less in the width direction.
Abstract: A donor sheet for pressure-sensitive image recording which comprises a support, an undercoating layer applied onto said support, and an overcoating layer applied onto said undercoating layer, said undercoating layer comprising microcapsules containing a solid wax, and said overcoating layer comprising microcapsules containing an image-forming component. By using said donor sheet, record images having a sufficiently high color density and a high resolution degree can be formed on a receptor sheet.
Abstract: A support for thermosensitive recording paper, said support being synthetic paper composed of a laminated film comprising a base layer composed of a biaxially stretched resin film and a paper-like layer composed of a uniaxially stretched film of a thermoplastic resin containing 10 to 50% by weight of calcium carbonate powder in a support made of synthetic paper and to be coated with a thermosensitive color forming layer and said support meeting the following physical properties (i) to (iii):(i) opacity is 45% or below as measured according to JIS P-8138,(ii) the paper-like layer to be coated with a thermosensitive color forming layer has Bekk smoothness of 100 to 300 sec and a surface roughness Ra of 1.5 .mu.m or below, and(iii) the support has a density of not higher than 1.1 g/cm.sup.3.