JP4596547B2 - Thermal transfer image receiving sheet - Google Patents

Description

  The present invention relates to a thermal transfer image receiving sheet.

In recent years, the adoption of a thermal transfer system has made it easy to obtain high-quality and high-definition images comparable to conventional silver salt photographs. By making such a sublimation transfer image a postcard size, it has come to be widely mailed as a postcard. When it is used as a postcard, it is necessary to print an address, address, etc. on the back side and affix a stamp. Until now, in order to give writability to the back surface of the image receiving sheet, for example, a hydrophilic filler has been used on the back surface of the thermal transfer image receiving sheet as disclosed in Patent Document 1, Patent Document 2, and Patent Document 3, for example. It is known that a porous layer is formed, or fine irregularities are imparted by a hard filler or a hard resin to provide writing properties.
Japanese Patent Laid-Open No. 6-239036 Japanese Patent Laid-Open No. 9-175052 JP-A-9-175048

  However, in the above conventional method, there is generally no problem with writing with a writing instrument, but when printing is performed using an inkjet printer, there are problems such as blurring of printing and slow drying of the printed portion. In addition, when using commercially available ink for inkjet printers, the composition of the ink and the solvent composition differ from manufacturer to manufacturer, so that the degree of bleeding after printing varies depending on the ink, and it is difficult to obtain uniform print quality.

  For this reason, methods for absorbing ink and preparing blots by adding various additives such as surfactants are known, but these additives are less stable against environmental changes such as temperature and humidity, so performance It is unsuitable for maintaining and may cause blocking. In general, in order to absorb the ink-jet ink composition, the ink receiving layer must be applied very thickly on the substrate. For this reason, it is difficult to provide a layer that enables ink jet printing with a production facility that is advantageous for those having a small coating amount such as a gravure coater or a bar coater. Further, in order to provide writing properties, fine irregularities are imparted, and depending on the degree of irregularities, the quality of the thermal transfer image receiving sheet may be impaired.

  In addition to the writing performance, it is important for the back surface of the thermal transfer image receiving sheet to have a stable paper supply / discharge characteristic by reducing friction with the image receiving surface. For example, as disclosed in JP-A-7-101163 and JP-A-7-223384, a method of reducing friction using a specific filler or resin is known. However, with these conventional methods, it is difficult to impart sufficient writing property and stamp adhesion property at the same time, even though the paper supply / discharge characteristics are excellent.

  The object of the present invention is to achieve good writing performance with an ink jet printer and various writing tools at a low coating amount without sacrificing quality due to unevenness on the back surface, satisfying stamp sticking properties, and excellent transportability in the printer. An object of the present invention is to provide a thermal transfer image-receiving sheet capable of stably exhibiting performance even after storage under high humidity and high temperature and humidity.

  The invention described in claim 1 solves the above-mentioned problem, and in a thermal transfer image-receiving sheet provided with a dye-receiving layer on at least one surface of a base sheet, a group on the side opposite to the surface on which the dye-receiving layer is formed. A hydrophilic porous layer mainly composed of polyvinyl butyral resin and hydrophilic porous particles is formed as a first layer on the surface of the material sheet, and a polyvinyl acetal resin, silicone-modified acrylic resin and nylon are further formed thereon as a second layer. A back coating layer containing resin particles is formed.

  In the present invention, the content of the silicone-modified acrylic resin is preferably 5 to 35% by weight of the total solid content in the second layer.

  In the present invention, the nylon resin particles preferably have an average particle size of 0.01 to 30 μm, and the nylon resin particle / resin weight ratio in the second layer is preferably 0.25 to 2.0.

  The thermal transfer image-receiving sheet of the present invention is a thermal transfer image-receiving sheet provided with a dye-receiving layer on at least one surface of a base material sheet. Polyvinyl chloride is used as the first layer on the surface of the base material sheet opposite to the surface on which the dye-receiving layer is formed. A hydrophilic porous layer mainly composed of butyral resin and hydrophilic porous particles is formed, and a back coating layer containing a polyvinyl acetal resin, a silicone-modified acrylic resin and nylon resin particles as a second layer is further formed thereon. Since it is formed, it enables printing with various writing instruments and inkjet printers after storage in high humidity and high temperature and high humidity, as well as in normal environments, has stickiness on stamps, and has high surface roughness. In addition to being felt in terms of quality, it has the advantage of having a very high practical value that can express stable transportability within the printer.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments of the present invention.

  As shown in FIG. 1, the thermal transfer image receiving sheet of the present invention is a base on the opposite side to the surface on which the dye receiving layer 2 is formed in the thermal transfer image receiving sheet having the dye receiving layer 2 on at least one surface of the substrate sheet 1. Formed on the surface of the material sheet 1 is a hydrophilic porous layer 3 mainly composed of polyvinyl butyral resin and hydrophilic porous particles, and further comprises a polyvinyl acetal resin, a silicone-modified acrylic resin and nylon resin particles on the back surface. A coating layer 4 is provided. In addition, as shown in FIG. 2, an intermediate layer 5 can be provided between the dye receiving layer 2 and the base sheet 1.

  Next, components of the thermal transfer image receiving sheet of the present invention will be described.

(1) Base sheet 1
In the present invention, the paper that can be used for the base sheet 1 can be any of various types of paper or processed paper, such as high-quality paper, coated paper, art paper, cast coated paper, and paperboard. Other examples include impregnated paper such as resin emulsion and synthetic rubber latex, and synthetic resin internal paper. Furthermore, laminated paper of these and various plastic films can also be used.

  Further, as the synthetic paper, polyolefin synthetic paper or polystyrene synthetic paper can be used, and as the plastic film, a polyolefin resin film, a polyester resin film, a polystyrene film, or the like can be used. These plastic films can be used not only as transparent films but also as white opaque films, white opaque films formed by adding fillers, or foamed films, and are not particularly limited.

  In addition, when using a plastic film, in order to adjust the rigidity of a film, you may add a plasticizer etc. as needed. Each of these materials can be used alone, but as described above, a laminate in which a plastic film is combined with other materials can also be used. Moreover, when forming an intermediate | middle layer and a dye receiving layer on these base material sheets, you may give a corona discharge process, a plasma discharge process, etc. as needed. The thickness of the base sheet is generally in the range of about 1 to 400 μm, and preferably about 100 to 300 μm.

(2) Dye-receiving layer 2
In the thermal transfer image-receiving sheet of the present invention, the dye image-receiving layer 2 may be a known one used in the sublimation biothermal transfer system, and is not particularly limited, but examples thereof include the following materials.
B) Resins having an ester bond Polyester resin, polyacrylate resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, and the like.
B) Resin having urethane bond Polyurethane resin, etc.
C) Resin having an amide bond Polyamide resin, etc.
D) Resins having urea bonds Urea resins, etc.
E) Other resins having a highly polar bond Polycaprolactone resin, styrene-maleic anhydride resin, polyvinyl chloride resin, polyacrylonitrile resin, and the like.
In addition to the synthetic resins as described above, a mixture or copolymer thereof can also be used.

  The dye-receiving layer is heat-pressed with a thermal head or the like together with the thermal transfer image-receiving sheet at the time of transfer. Therefore, the thermal transfer image-receiving sheet is easy to stick, and usually a dye-permeable mold release resin as described above. It is formed by containing an agent. As such a release agent, solid waxes, fluorine-based or phosphate-based surfactants, and oily silicone oils can be used, but reactive curing type is preferable, for example, amino-modified A combination of silicone and epoxy-modified silicone is preferred.

  In the case of solid wax, the amount of these release agents added is 0.5 to 50% by weight, preferably 0.5 to 10% by weight, based on the weight of the resin in the resin. In the case of curable silicone oil, it is not sticky and can be used in a large amount, and can be added in the range of 0.5 to 30% by weight of the resin weight. In either case, if the amount is too small, the releasing effect is insufficient, and if the amount is too large, the acceptability of the dye is lowered, and there is an adverse effect such that a sufficient recording density cannot be obtained.

  Moreover, as a method for imparting the mold releasability of the dye receiving layer, in addition to the method for adding a releasing agent to the dye receiving layer as described above, it is also possible to laminate a release layer separately on the dye receiving layer. Any method may be used. Further, the dye-receiving layer may contain an inorganic filler such as fine powder silica and titanium oxide, an antioxidant, an ultraviolet absorber, and the like as necessary.

  In forming the dye-receiving layer on the base sheet, for example, a gravure printing method, a screen printing method, or a gravure plate was used in which these materials were dissolved in an organic solvent or a liquid dispersed in an organic solvent or water was used. It can be formed by applying and drying by a reverse roll coating method, a die coating method or the like. Depending on the type of material, it can be formed by a melt extrusion coating method without using an organic solvent or water. The dye receiving layer formed as described above may have any thickness, but is generally formed to a thickness of 1 to 50 μm.

(3) Intermediate layer 5
Any conventionally known intermediate layer can be provided between the receiving layer and the base sheet for the purpose of imparting adhesiveness to the receiving layer, preventing curling, and the like. Binder resin used in the intermediate layer is polyurethane resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer Examples include coalesced resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl alcohol resin, epoxy resin, cellulose resin, ethylene-vinyl acetate copolymer resin, polyethylene resin, polypropylene resin, etc. Among these resins, active hydrogen Further, those having a cured product of isocyanate can be used as an intermediate layer.

  Moreover, it is preferable to add fillers such as titanium oxide, magnesium oxide and calcium carbonate in order to impart whiteness and concealability. In addition, stilbene compounds, benzimidazole compounds, benzoxazole compounds, etc. are added as fluorescent brightening agents to increase whiteness, and hindered amine compounds, hindered phenol compounds are used to increase the light fastness of prints. Compounds, benzotriazole compounds, benzophenone compounds can be added as UV absorbers or antioxidants, or cationic acrylic resins, various conductive fillers, etc. can be added to impart antistatic properties. .

(4) Back surface layer The back surface layer has a two-layer structure, and the first layer (hydrophilic porous layer 3) mainly plays the following three roles. The first is good adhesion to the base sheet and the second layer (back surface coating layer 4), the second is the ink absorbability of various writing instruments and the ink jet printer, the third is pencils, etc. A certain degree of hardness and unevenness required for writing.

  The second layer (back surface coating layer 4) mainly plays the following three roles. The first is prevention of bleeding of ink jet printer printing and ink fixing, the second is stamp stickability, and the third is high slipperiness.

  The first layer (hydrophilic porous layer 3) quickly absorbs the thermoplastic resin component having good adhesion to the substrate surface, various writing instrument inks and ink compositions for inkjet printers, It comprises hydrophilic porous particles for imparting irregularities.

  As a preferable thermoplastic resin component, a resin effective as a binder is used, and resins such as polyvinyl acetal, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl butyral, cellulose acetate, nitrile cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, starch, gelatin and the like are used. And water-soluble acrylic resins, water-soluble urethane resins, and mixtures and copolymers thereof, but when considering the combination of materials, butyral resin or acetal resin is particularly suitable for adhesion to the second layer. Is preferable.

  As the hydrophilic porous particles added to the thermoplastic resin, silica, alumina, talc, calcium carbonate, barium carbonate, zinc oxide, titanium oxide, or the like is used. Of these, silica particles having high absorbability are preferable. The average particle diameter of the particles is 0.1 to 20 μm, preferably 1 to 15 μm. If the particle size is less than 0.1 μm, the unevenness necessary for writing such as a pencil cannot be maintained, and if it exceeds 20 μm, the surface feel becomes poor and the coating film strength becomes weak and the particles may be peeled off.

  Further, in order to make the ink absorption and holding function more preferable, the particle / resin weight ratio in the first layer is preferably 1.0 to 3.0, particularly preferably 1.5 to 2.0. .

In the first layer, an additive is added to the above-described composition as necessary, and a solution or dispersion composition dissolved or dispersed in an appropriate organic solvent or water is used, for example, gravure printing, screen printing, gravure printing The first layer is applied to the base sheet 1 by about 0.5 to 20 g / m ² , and in particular, the applied amount is about 1.0 to 10 g / m ^2. It is preferable to form by.

  As described above, the second layer includes polyvinyl acetal resin, silicone-modified acrylic resin, and nylon resin particles. The polyvinyl acetal resin plays a role of fixing an ink composition for an ink jet printer and a role of a binder. The silicone-modified acrylic resin prevents bleeding of inks for various writing instruments and ink compositions for ink jet printers and plays a role of developing slipperiness. Further, the nylon resin particles play a role of quickly transferring the ink composition to the first layer and exhibiting slipperiness.

  The degree of acetalization of the polyvinyl acetal resin is generally in the range of 2 to 40 mol%, preferably 3 to 30 mol%, more preferably 5 to 20 mol%. When the degree of acetalization is low, the ink fixability may deteriorate.

  As the silicone-modified acrylic resin, an acrylic resin obtained by graft copolymerization or block copolymerization of polyorganosiloxane can be used. In the case of an aqueous system, an aqueous solution of a silicone-modified acrylic resin and an emulsion-dispersed aqueous solution can be used. The acrylic main chain having a high affinity with the polyvinyl butyral resin in the first layer of the silicone-modified acrylic resin keeps the adhesion to the base sheet, and conversely, the silicone part having a low affinity with the first layer resin It exists on the opposite side, that is, the surface of the back surface of the thermal transfer image-receiving sheet, and acts to modify the surface with water repellency. With a certain degree of water repellency, it is possible to adjust the penetration of the ink of the writing instrument and the ink jet ink which are very easy to bleed, and bleed can be prevented. In addition, the presence of the silicone portion on the back surface of the thermal transfer image receiving sheet improves slipperiness when superimposed on the image receiving surface, and can provide stable conveyance of the image receiving sheet.

  In the case of an emulsion-dispersed aqueous solution, the emulsion particle diameter is preferably 40 to 150 nm, and particularly preferably 60 to 100 nm. If it is less than 40 nm, there are places where it is difficult to produce, and the cost is also high. On the other hand, if the thickness is larger than 150 nm, ink bleeding of various writing instruments tends to occur.

  The content of the silicone-modified acrylic resin is preferably 5 to 35% by weight with respect to the total solid content in the second layer. If it is less than 5% by weight, the effect of preventing ink bleeding is not exhibited, leading to a decrease in writing performance. On the other hand, if it exceeds 35% by weight, the fixing property of the ink is lowered.

  Nylon resin particles having a molecular weight of 10 to 900,000 and spherical, preferably having an average particle diameter of 0.01 to 30 μm, particularly having a molecular weight of 100 to 500,000 and an average particle diameter of 0.01 to 30 μm Is more preferable. As for the type of nylon resin particles, nylon 12 filler is more preferable than nylon 6 or nylon 66 because it is superior in water resistance and does not change in characteristics due to absorption.

  When the average particle diameter is less than 0.01 μm, the filler is hidden in the second layer, the quick drying property of the ink jet printing is poor, and the slippery function is not achieved. On the other hand, if the particle diameter is too large, the protrusion from the back surface layer becomes large, the touch becomes poor and the quality is lowered, and bleeding occurs when writing with various writing tools, leading to a decrease in writing performance.

  The weight ratio of nylon resin particles / resin in the second layer is preferably in the range of 0.25 to 2.0, particularly 0.5 to 1.0. If the weight ratio is less than 0.25, the quick-drying property of ink jet printing is poor, and the slipping property is lowered. On the other hand, when it exceeds 2.0, the film strength is lowered, ink fixing property of ink jet printing is lowered, and ink bleeding at the time of writing with various writing tools is increased.

For the second layer, an additive is added to the above composition as necessary, and a solution or dispersion composition dissolved or dispersed in an appropriate organic solvent or water is used, for example, gravure printing, screen printing, gravure, etc. Coating and drying are performed by a forming means such as a reverse coating method using a plate, and formed on the first layer at a coating amount of about 0.3 to 20 g / m ² , especially 0.5 to 5.0 g / m ^2. It is preferable.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the scope of the present invention is not limited to the content of these Examples. In Examples and Comparative Examples, “parts” means “% by weight” and “parts by weight” unless otherwise specified.

Example 1
Applying and drying a first layer made of a composition of the following composition on a base sheet (150 μm thick synthetic paper (FPG # 150 made by YUPO Corporation)) to a coating amount of 1.5 g / m ² when dried. Then, a second layer made of a composition having the following composition is applied and dried so as to be 0.7 g / m ² when dried, and the back surface of the thermal transfer image-receiving sheet is formed to form the thermal transfer image-receiving sheet of Example 1. Was made.

Composition of composition constituting first layer Polyvinyl butyral resin 100 parts (manufactured by Denki Kagaku Kogyo Co., Ltd., # 3001-1)
Microsilica (average particle size 3.0 μm) 100 parts (Fuji Silysia Co., Ltd., Silicia 730)
Microsilica (average particle size 1.4 μm) 80 parts (manufactured by Fuji Silysia Ltd., Silicia 310)
Water / isopropyl alcohol = 1/1 ... 200 parts

Composition of composition constituting second layer Polyvinyl acetal resin (Sekisui Chemical Co., Ltd., KX-5) ... 100 parts Nylon filler (average particle size 7.5 [mu] m) ... 100 parts (Shinto paint) (MW330)
Silicone-modified acrylic resin (manufactured by JSR): 11 parts Water / isopropyl alcohol = 1/1: 2000 parts

  The thermal transfer image-receiving sheet of Example 1 produced as described above was evaluated by the following evaluation method.

Evaluation method 1. Inkjet printer printability The performance of the printed thermal transfer image-receiving sheet was evaluated by printing on the back side of the thermal transfer image-receiving sheet using an inkjet printer. The printer used was PM770C manufactured by Seiko Epson Corporation and BJF850 manufactured by Canon Inc., and the ink used was genuine ink designated by each manufacturer.
(1) Bleeding of ink The bleeding in arbitrary character printing was visually evaluated according to the following criteria.
○ No bleeding △ Slight bleeding × Severe bleeding
(2) Ink fixability Ink fixability is the time when the back of the thermal transfer image-receiving sheet is printed and then a white paper is placed on the printed surface and pressed at a pressure of 34 gf / cm ² for 5 seconds, and the paper is not set off on the white paper. Were measured and evaluated.
○ No ink transfer within 120 seconds △ No ink transfer within 300 seconds x Ink transfer even after 300 seconds Writability Characters were written on the back surface of the thermal transfer image-receiving sheet using oil-based pens, water-based pens, pencils, and ballpoint pens as representative writing tools, and the writability was evaluated according to the following criteria.
○ Can be written smoothly with sufficient density, no bleeding, and good fixability.
△ Characters are slightly thin. Or something with a slight bleeding.
× Characters that cannot be read with just a slight rubbing with a finger. Or something difficult to write.
3. Printer Conveyance 30 sheets of thermal transfer image-receiving sheets cut to A6 size were stacked to perform continuous printing of black solid images. A total of 150 sets of these were carried out, and the transportability was evaluated based on the number of occurrences of paper feed errors such as paper jams. Olympus P-330 was used for the printer.
○ No paper feeding / discharging trouble × There is a paper feeding / discharging problem, which is a practical problem.
4). Surface roughness The sensory evaluation by hand was performed on the unevenness of the back surface.
○ There is no unevenness and it feels high quality. △ There are a little unevenness and the texture is felt low. × There are many unevenness and the texture is damaged. Stamp stickability Tap water was applied to the half of the adhesive surface of a Japanese postage stamp and attached to the back of the thermal transfer image-receiving sheet. After leaving for 5 hours, the part not coated with tap water was held by hand, the stamp was peeled off from the image receiving sheet, and evaluated according to the following criteria.
○ After the stamp is peeled off, a part of the stamp remains on the back surface of the thermal transfer image-receiving sheet and a trace remains. × The stamp is easily peeled off from the back surface of the thermal transfer image-receiving sheet, and no trace remains. Environmental stability The image-receiving sheet was stored for 7 days under conditions of a temperature of 60 degrees, a humidity free of 40 degrees, and a humidity of 90%, and then the printing evaluation and the writing performance were evaluated by the ink jet printer.
○ No bleed and writing with writing utensils × Bleeding or difficult to write with writting tools

  As a result of the evaluation by the above-described evaluation method, as a result of the printing test by the ink jet printer, there is no problem in bleeding and ink fixing property for both models of PM770C and BJF850, the writing property is good, the printer transportability is satisfactory, and the surface It has been found that it has no stickiness, has ticket sticking properties, and has environmental stability.

(Example 2)
In the same manner as in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image receiving sheet of Example 2 was produced.

Composition of composition constituting second layer Polyvinyl acetal resin (Sekisui Chemical Co., Ltd., KX-5) ... 100 parts Nylon filler (average particle size 7.5 [mu] m) ... 100 parts (Shinto paint) (MW330)
Silicone-modified acrylic resin (manufactured by JSR) ... 107 parts Water / isopropyl alcohol = 1/1 ... 2000 parts

  The thermal transfer image-receiving sheet produced as described above was evaluated by the same evaluation method as that performed in Example 1. As a result, as a result of the printing test by the ink jet printer, there is no problem with bleeding and ink fixing property for both models PM770C and BJF850, the writing property is good, the printer transportability is satisfactory, the surface is not rough, and the ticket sticking property is good. It was found to have environmental stability.

(Example 3)
In the same manner as in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image-receiving sheet of Example 3 was produced.

Composition of composition constituting second layer Polyvinyl acetal resin (Sekisui Chemical Co., Ltd., KX-5) ... 100 parts Nylon filler (average particle size 7.5 [mu] m) ... 27.75 parts (God Made by East Paint Co., Ltd., MW330)
Silicone-modified acrylic resin (manufactured by JSR): 11 parts Water / isopropyl alcohol = 1/1: 2000 parts

  The thermal transfer image-receiving sheet produced as described above was evaluated by the same evaluation method as that performed in Example 1. As a result, as a result of the printing test by the ink jet printer, there is no problem with bleeding and ink fixing property for both models PM770C and BJF850, the writing property is good, the printer transportability is satisfactory, the surface is not rough, and the ticket sticking property is good. It was found to have environmental stability.

Example 4
In the same manner as in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image receiving sheet of Example 4 was produced.

Composition of composition constituting second layer Polyvinyl acetal resin (Sekisui Chemical Co., Ltd., KX-5) ... 100 parts Nylon filler (average particle size 7.5 [mu] m) ... 240 parts (Shinto paint) (MW330)
Silicone-modified acrylic resin (manufactured by JSR) 20 parts Water / Isopropyl alcohol = 1/1 2000 parts

  The thermal transfer image-receiving sheet produced as described above was evaluated by the same evaluation method as that performed in Example 1. As a result, as a result of the printing test by the ink jet printer, both the PM770C and BJF850 models have no problem with bleeding and ink fixing property, the writing property is good, the printer transportability is satisfactory, the surface is not rough, and the ticket sticking property is good. It was found to have environmental stability.

(Example 5)
In the same manner as in Example 1, except that the constituent material of the first layer was changed to the following composition, a thermal transfer image receiving sheet of Example 5 was produced.

Composition of composition constituting first layer Polyvinyl butyral resin 100 parts (manufactured by Denki Kagaku Kogyo Co., Ltd., # 3001-1)
Microsilica (average particle size: 3.0 μm) 50 parts (Fuji Silysia Co., Ltd., Silicia 730)
Microsilica (average particle size 1.4 μm) 50 parts (Fuji Silysia Co., Ltd., Silicia 310)
Water / isopropyl alcohol = 1/1 ... 300 parts

  The thermal transfer image-receiving sheet produced as described above was evaluated by the same evaluation method as that performed in Example 1. As a result, as a result of the printing test by the ink jet printer, there is no problem with bleeding and ink fixing property for both models PM770C and BJF850, the writing property is good, the printer transportability is satisfactory, the surface is not rough, and the ticket sticking property is good. It was found to have environmental stability.

(Example 6)
In the same manner as in Example 1, except that the constituent material of the first layer was changed to the following composition, a thermal transfer image receiving sheet of Example 6 was produced.

Composition of composition constituting first layer Polyvinyl butyral resin 100 parts (manufactured by Denki Kagaku Kogyo Co., Ltd., # 3001-1)
Microsilica (average particle size 3.0 μm) 150 parts (Fuji Silysia KK, Silicia 730)
Microsilica (average particle size 1.4 μm) 150 parts (manufactured by Fuji Silysia Co., Ltd., Silicia 310)
Water / isopropyl alcohol = 1/1 ... 300 parts

  The thermal transfer image-receiving sheet produced as described above was evaluated by the same evaluation method as that performed in Example 1. As a result, as a result of the printing test by the ink jet printer, there is no problem with bleeding and ink fixing property for both models PM770C and BJF850, the writing property is good, the printer transportability is good, the surface is not rough, and the ticket sticking property is good. It was found to have environmental stability.

(Comparative Example 1)
The thermal transfer image receiving sheet of Comparative Example 1 was prepared in the same manner as in Example 1, except that only the first layer was coated on the back surface of the base sheet.

  The thermal transfer image-receiving sheet of Comparative Example 1 produced as described above was evaluated by the same evaluation method as that performed in Example 1. As a result, as a result of a printing test using an ink jet printer, both PM770C and BJF850 models showed significant bleeding, no ink fixing property, and ink transfer.

(Comparative Example 2)
The thermal transfer image receiving sheet of Comparative Example 2 was prepared in the same manner as in Example 1, except that only the second layer was coated on the back surface of the base sheet.

  The thermal transfer image-receiving sheet of Comparative Example 2 produced as described above was evaluated by the same evaluation method as performed in Example 1. As a result, as a result of a print test using an ink jet printer, both the PM770C and BJF850 models have poor ink fixability, requiring a long time for fixing, and inferior in writing performance with an aqueous pen and writing performance with a pencil.

(Comparative Example 3)
As in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image-receiving sheet of Comparative Example 3 was produced.

Composition of the composition constituting the second layer Nylon filler (average particle size 7.5 [mu] m) ... 100 parts (MW330, manufactured by Shinto Paint Co., Ltd.)
Silicone-modified acrylic resin (manufactured by JSR): 100 parts Water / isopropyl alcohol = 1/1: 2000 parts

  The thermal transfer image-receiving sheet of Comparative Example 3 produced as described above was evaluated by the same evaluation method as performed in Example 1. As a result, as a result of a printing test using an ink jet printer, both PM770C and BJF850 models showed significant bleeding, no ink fixing property, and ink transfer. It was found that the writing ability with a water-based pen was lacking.

(Comparative Example 4)
In the same manner as in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image receiving sheet of Comparative Example 4 was produced.

Composition of the composition constituting the second layer Polyvinyl acetal resin (manufactured by Sekisui Chemical Co., Ltd., KX-5) ... 100 parts silicone-modified acrylic resin (manufactured by JSR) ... 11 parts water / isopropyl alcohol = 1 / 1 ... 2000 copies

  The thermal transfer image-receiving sheet of Comparative Example 4 produced as described above was evaluated by the same evaluation method as performed in Example 1. As a result, it was found that a paper supply / discharge trouble occurred and there was a practical problem with respect to printer transportability.

(Comparative Example 5)
In the same manner as in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image receiving sheet of Comparative Example 5 was produced.

Composition of the composition constituting the second layer Polyvinyl acetal resin (Sekisui Chemical Co., Ltd., KX-5) ... 100 parts Nylon filler (average particle size 30 [mu] m) ... 100 parts (Nippon Rilsan Co., Ltd.) Manufactured by Olgasol 2002 ES-3)
Silicone-modified acrylic resin (manufactured by JSR): 11 parts Water / isopropyl alcohol = 1/1: 2000 parts

  The thermal transfer image-receiving sheet of Comparative Example 5 produced as described above was evaluated by the same evaluation method as performed in Example 1. As a result, it was found that the surface roughness was poor and the texture was inferior.

(Comparative Example 6)
In the same manner as in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image receiving sheet of Comparative Example 5 was produced.

Composition of composition constituting second layer Polyvinyl acetal resin (Sekisui Chemical Co., Ltd., KX-5) ... 100 parts Nylon filler (average particle size 7.5 [mu] m) ... 100 parts (Shinto paint) (MW330)
Water / isopropyl alcohol = 1/1 ... 2000 parts

  The thermal transfer image-receiving sheet of Comparative Example 6 produced as described above was evaluated by the same evaluation method as performed in Example 1. As a result, BJF850 was noticeably blurred as a result of a print test using an inkjet printer. In addition, some bleeding was observed for PM770C.

(Comparative Example 7)
In the same manner as in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image receiving sheet of Comparative Example 5 was produced.

Composition of composition constituting second layer Polyvinyl acetal resin (Sekisui Chemical Co., Ltd., KX-5) ... 100 parts Nylon filler (average particle size 7.5 [mu] m) ... 100 parts (Shinto paint) (MW330)
Surfactant (Dainippon Ink Co., Ltd., MegaFac F470) 2 parts Water / Isopropyl alcohol = 1/1 2000 parts

  The thermal transfer image-receiving sheet of Comparative Example 7 produced as described above was evaluated by the same evaluation method as performed in Example 1. As a result, it was found that this thermal transfer auxiliary image sheet satisfies all of the ink jet printer printability, writing property, printer transportability, back surface condition, and stamp sticking property, but lacks environmental stability.

(Comparative Example 8)
In the same manner as in Example 1, except that the constituent material of the second layer was changed to the following composition, a thermal transfer image receiving sheet of Comparative Example 8 was produced.

Composition of composition constituting second layer Polyvinyl acetal resin (Sekisui Chemical Co., Ltd., KX-5) ... 100 parts Nylon filler (average particle size 7.5 [mu] m) ... 100 parts (Shinto paint) (MW330)
Acrylic resin (manufactured by Daicel Chemical Industries) ... 11 parts Water / Isopropyl alcohol = 1/1 ... 2000 parts

  The thermal transfer image-receiving sheet of Comparative Example 8 produced as described above was evaluated by the same evaluation method as performed in Example 1. As a result, as a result of a print test using an ink jet printer, it was found that PM770C has a slight blur and BFJF850 has a significant blur.

  Table 1 shows the results of evaluation relating to the thermal transfer image receiving sheets of Examples 1 to 6 and Comparative Examples 1 to 8.

It is sectional drawing of the thermal transfer image receiving sheet of this invention. It is sectional drawing of another embodiment of the thermal transfer image receiving sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material sheet 2 Dye receiving layer 3 Hydrophilic porous layer 4 Back surface coating layer 5 Intermediate layer

Claims (3)

  In a thermal transfer image-receiving sheet having a dye-receiving layer on at least one surface of a substrate sheet, polyvinyl butyral resin and hydrophilic porous particles as a first layer on the surface of the substrate sheet opposite to the surface on which the dye-receiving layer is formed The thermal transfer is characterized in that a hydrophilic porous layer mainly composed of a resin is formed, and a back coating layer containing a polyvinyl acetal resin, a silicone-modified acrylic resin and nylon resin particles is formed thereon as a second layer. Image receiving sheet.   The thermal transfer image-receiving sheet according to claim 1, wherein the content of the silicone-modified acrylic resin is 5 to 35% by weight of the total solid content in the second layer. The average particle diameter of the nylon resin particles is 5 to 20 µm, and the weight ratio of nylon resin particles / resin in the second layer is 0.25 to 2.0. Thermal transfer image receiving sheet.

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