JP4664175B2 - Thermal transfer image receiving sheet and method for producing thermal transfer image receiving sheet - Google Patents

Description

  The present invention relates to a thermal transfer image-receiving sheet used in an image forming method using a thermal transfer system, and more particularly to a thermal transfer image-receiving sheet that is excellent in releasability even after printing a plurality of times.

  Conventionally, an image forming method using a thermal transfer method is known as one of color or monochrome image forming techniques, and has been widely used as a means for easily obtaining a high-quality image. The thermal transfer system is a method for forming an image by transferring a thermal transfer sheet having a dye exhibiting specific thermal properties from a thermal transfer sheet to a thermal transfer image receiving sheet using a thermal printing device such as a thermal head or a laser. is there. Such a thermal transfer system has the advantage that the apparatus can be miniaturized and is low in cost.

The thermal transfer system is roughly classified into two types, a thermal melting transfer system and a thermal diffusion transfer system, depending on a dye transfer mechanism from the thermal transfer sheet to the thermal transfer image receiving sheet. The thermal melt transfer system is a system in which an image is formed by using a thermal transfer sheet having a hot melt dye and transferring the hot melt dye to a thermal transfer image receiving sheet by a heat transfer process. On the other hand, the thermal diffusion transfer system is a system in which an image is formed by using a thermal transfer sheet having a thermal diffusible dye and transferring the thermal diffusible dye to a thermal transfer image receiving sheet by a thermal diffusion transfer mechanism.
In the thermal diffusion transfer method, by controlling the degree of heating of the thermal transfer sheet, the transfer amount of the thermal diffusible dye to the thermal transfer image-receiving sheet can be arbitrarily adjusted. An image can be formed, which is advantageous for full-color image formation. Because of these advantages, thermal diffusion transfer-type thermal transfer technology is widely used in business photographs, personal computer printers, video printers, and the like.

By the way, since the thermal transfer image receiving sheet used in such a thermal transfer system forms a high-definition image, it is necessary to exhibit excellent releasability in relation to the thermal transfer sheet. If the releasability of the receiving layer is low, the heat transfer sheet dye binder and the image receiving layer are likely to be fused, resulting in a loud peeling sound during printing, or in some cases, it is completely fused, and it is normal from the printer. Problems such as prints not being ejected occur.
In particular, in the thermal transfer system, since an image is usually formed by a subtractive color method, yellow, magenta, and cyan dyes are sequentially printed on the thermal transfer image receiving sheet. Therefore, since the thermal transfer image-receiving sheet is subjected to at least three times of printing processing, the above-mentioned releasability is not limited to simply excellent releasability, and excellent releasability is maintained in any of the three times of printing processing. It is necessary to have mold release stability that can be achieved. In addition, when transferring the protective layer in order to impart durability after image formation, it is further required to have excellent releasability in the three printing processes and also have adhesiveness of the subsequent protective layer.
As a means for improving the mold release property and mold release stability, a method in which a release agent having a function of improving the mold release property is included in the receiving layer is generally used.

  Patent Document 1 discloses a method of adding a release agent made of silicone oil to the receiving layer in order to improve the release property between the thermal transfer image receiving sheet and the thermal transfer sheet. Since such a method uses silicone oil, the mold release property can be improved, but there is a problem that the mold release stability is insufficient. In addition, the silicone oil has a problem in that when a receiving layer is formed by a melt extrusion method, the bleed-out during processing is large and the printing image quality is deteriorated.

Japanese Patent Laid-Open No. 2001-030639

  The present invention has been made in view of the above problems, and has as its main object to provide a thermal transfer image-receiving sheet that is excellent in releasability even after printing a plurality of times by a thermal transfer system. It is.

In order to solve the above problems, the present invention is a thermal transfer image receiving sheet comprising a base sheet and a receiving layer formed on the base sheet and containing a binder resin, high molecular weight silicone, and silicone, and the kinematic viscosity of the high molecular weight silicone 500,000 mm ² / s or more, and wherein the kinematic viscosity of the low molecular weight-modified silicone is in the range of 100mm ² / s~10 ten thousand mm ² / s A thermal transfer image receiving sheet is provided.

According to the present invention, the above-receiving layer, by the kinematic viscosity include low molecular weight-modified silicone is in the range of 100mm ² / s~10 ten thousand mm ² / s, excellent the receiving layer releasability Can be a thing. In addition, since the high-molecular weight silicone having a kinematic viscosity of 500,000 mm ² / s or more is contained in the receiving layer, the low-molecular weight modified silicone can be prevented from bleeding out from the receiving layer. Sex change can be suppressed. Therefore, according to the present invention, it is possible to obtain a thermal transfer image-receiving sheet that is excellent in releasability and excellent in releasability without deteriorating releasability even after printing a plurality of times.

  In the present invention, the mass ratio of the high molecular weight silicone in the receptor layer to the low molecular weight modified silicone (mass of high molecular weight silicone: mass of low molecular weight modified silicone) is in the range of 1: 4 to 4: 1. It is preferable to be within. The thermal transfer image-receiving sheet of the present invention is more excellent in releasability and releasability because the mass ratio of the high molecular weight silicone and the low molecular weight modified silicone in the receiving layer is within such a range. Because it can be.

Further, the present invention provides a receptor layer forming step for forming a receptor layer by melt-extruding a receptor layer forming resin containing a binder resin, a high molecular weight silicone, and a low molecular weight modified silicone; A method for producing a thermal transfer image receiving sheet for producing a thermal transfer image receiving sheet in which a receiving layer is laminated on a substrate by laminating a receiving layer formed by a film process and a substrate sheet, wherein the high molecular weight kinematic viscosity of the silicone is 500000 mm ² / s or more, and a thermal transfer image-receiving sheet kinematic viscosity of the low molecular weight-modified silicone is characterized in that in the range of 100mm ² / s~10 ten thousand mm ² / s A manufacturing method is provided.

According to the present invention, in the receptor layer forming resin, a high molecular weight silicone kinematic viscosity of 500,000 mm ² / s or more, a kinematic viscosity in the range of from 100mm ² / s~10 ten thousand mm ² / s Since the low molecular weight modified silicone is contained, the low molecular weight modified silicone can be prevented from bleeding out at the time of melt extrusion, so that a high-productivity thermal transfer image-receiving sheet excellent in releasability and releasability is produced. be able to.

  In the present invention, the receptive layer forming step includes heat insulation including the receptive layer forming resin, a thermoplastic resin, and at least one of an incompatible resin or filler incompatible with the thermoplastic resin. By melt coextrusion of the layer forming resin, a receiving layer laminate in which the receiving layer and the heat insulating layer are laminated is formed, and the laminating step includes the heat insulating layer of the receiving layer laminate, Lamination is performed so that the base sheet adheres, and it is preferable to further include a stretching step of stretching the receiving layer laminate between the receiving layer forming step and the laminating step. This is because according to such a manufacturing method, a thermal transfer image-receiving sheet on which a heat insulating layer having a desired porosity is formed can be easily formed.

  The present invention has an effect that it is possible to provide a thermal transfer image-receiving sheet that is excellent in releasability even after printing a plurality of times.

  Hereinafter, the thermal transfer image receiving sheet of the present invention and the method for producing the thermal transfer image receiving sheet will be described.

A. First, the thermal transfer image receiving sheet of the present invention will be described. The thermal transfer image-receiving sheet of the present invention has a base sheet and a receiving layer formed on the base sheet and containing a binder resin, a high molecular weight silicone, and a low molecular weight modified silicone. viscosity of 500,000 mm ² / s or more, and in which kinematic viscosity of the low molecular weight-modified silicone is characterized in that in the range of 100mm ² / s~10 ten thousand mm ² / s.

Next, the thermal transfer image receiving sheet of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an example of the thermal transfer image receiving sheet of the present invention. As illustrated in FIG. 1, the thermal transfer image receiving sheet 10 of the present invention includes a base sheet 1 and a receiving layer 2 formed on the base sheet 1. In the thermal transfer image-receiving sheet 10 shown in FIG. 1, the receiving layer 2 and the binder resin, a high molecular weight silicone is kinematic viscosity 500,000 mm ² / s or more, a kinematic viscosity of 100mm ² / s~10 ten thousand mm ² / s And a low molecular weight modified silicone that falls within the range.

  The thermal transfer image receiving sheet of the present invention may have other layers in addition to the base sheet and the receiving layer. FIG. 2 is a schematic sectional view showing another example of the thermal transfer image receiving sheet of the present invention. As illustrated in FIG. 2, the thermal transfer image receiving sheet 11 of the present invention has a heat insulating layer 3 and an adhesive layer 4 between the base sheet 1 and the receiving layer 2, and receives the base sheet 1. The back surface layer 5 may be formed on the surface opposite to the surface on which the layer 2 is formed.

According to this invention, mold release stability can be improved by the said low molecular weight modified silicone and the said high molecular weight silicone being contained in the said receiving layer. Thus, although it is not clear about the mechanism which can improve mold release stability by including the said low molecular weight modified silicone and the said high molecular weight silicone in the said receiving layer, it thinks based on the following mechanisms.
That is, since the low molecular weight modified silicone is present on the surface of the receptor layer, the surface energy of the receptor layer can be lowered, and thus has a high releasability. However, since the molecular weight is low, it tends to bleed out on the surface of the receiving layer, so that when the dye is printed on the receiving layer, it is transferred to the thermal transfer sheet. Therefore, when the low molecular weight modified silicone is used alone, there is a problem that the releasability of the receiving layer is lowered by one printing.
On the other hand, since the high molecular weight silicone has a large molecular weight, when the dye is printed on the receiving layer, it is rarely transferred to the thermal transfer sheet, so that the releasing property of the receiving layer hardly changes by one printing. However, there is a drawback that the function of reducing the surface energy of the receiving layer is insufficient as compared with the low molecular weight modified silicone. Therefore, when a high molecular weight silicone is used alone, there is a problem that desired releasability cannot be obtained.
Here, since the low molecular weight modified silicone and the high molecular weight silicone are common in having Si, the low molecular weight modified silicone and the high molecular weight silicone interact with each other through Si by using a mixture thereof. be able to.
Therefore, in the present invention, since the receiving layer has both the low molecular weight modified silicone and the high molecular weight silicone, the high molecular weight silicone is transferred to the thermal transfer sheet from the high molecular weight silicone by the interaction. Therefore, it is considered that excellent release stability can be expressed.

  In the present invention, the low molecular weight modified silicone is used as the low molecular weight silicone because it has a weak compatibility with the receiving layer resin by modification, and is a bleed-out during extrusion film formation or heat setting after stretching, or dye transfer. This is because silicone is present in a well-balanced manner on the surface of the receiving layer, and good release properties can be imparted to the receiving layer. Furthermore, by using a low molecular weight modified silicone, when the protective layer is transferred after image formation, the bleeding out of the silicone that inhibits the adhesion to the protective layer is suppressed, and by using the organically modified silicone. It is because the adhesiveness improvement of a protective layer can also be anticipated from the effect of compatibility improvement with a protective layer.

  The thermal transfer image receiving sheet of the present invention has a base sheet and a receiving layer. Hereafter, each structure of the thermal transfer image receiving sheet of this invention is demonstrated in detail.

1. Receiving layer First, the receiving layer used in the present invention will be described. The receiving layer used in the present invention contains a binder resin, a high molecular weight silicone, and a low molecular weight modified silicone, and is transferred from the thermal transfer sheet when an image is formed using the thermal transfer image receiving sheet of the present invention. It has a function of accepting a dye.

(1) High molecular weight silicone The high molecular weight silicone used for this invention is demonstrated. The high molecular weight silicone used in the present invention has a kinematic viscosity of 500,000 mm ² / s or more. In the present invention, the kinematic viscosity of the high molecular weight silicone is defined as described above. When the kinematic viscosity is less than 500,000 mm ² / s, the mobility of the high molecular weight silicone in the receptor layer is increased, which This is because the function of suppressing the bleed out of the low molecular weight modified silicone is insufficient.
The kinematic viscosity of the high molecular weight silicone in the present invention may be 500,000 mm ² / s or more, and even a solid high molecular weight silicone can be suitably used. Especially, in this invention, it is preferable that kinematic viscosity of high molecular weight silicone is 10 million mm < ² > / s or more. The kinematic viscosity of the high molecular weight silicone in the present invention refers to a value measured at a temperature of 25 ° C. based on the viscosity measuring method described in JIS Z8803 unless otherwise specified. The kinematic viscosity can be measured by, for example, a single cylinder type rotational viscometer TVB33H (U) manufactured by Toki Sangyo Co., Ltd.

  The high molecular weight silicone used in the present invention is not particularly limited as long as it has a polysiloxane structure, but is preferably compatible with the binder resin described later.

  The high molecular weight silicone used in the present invention may be an unmodified silicone (straight silicone) or a modified silicone. In the present invention, only one kind may be used as the high molecular weight silicone, or two or more kinds may be mixed and used.

  Examples of the unmodified silicone include dimethyl silicone, methyl phenyl silicone, and methyl hydrogen silicone.

  The modified silicone is not particularly limited as long as it has a polysiloxane structure having an organic functional group, but has a structure in which a part of methyl group of dimethyl silicone is substituted (modified) with an organic functional group. It is preferable to use what has. Examples of the modified silicone having such a structure include a side-chain modified silicone in which an organic functional group is bonded to part of a side chain of polysiloxane, and a both-end modified silicone in which an organic functional group is bonded to both ends of polysiloxane. , One-end-type modified silicone in which an organic functional group is bonded to one end of polysiloxane, side-chain both-end-type modified silicone in which an organic functional group is bonded to a part of both side chains and both ends of polysiloxane, Name the side-chain single-end modified silicone with organic functional groups bonded to part of the polysiloxane side chain and one terminal, and the main-chain modified silicone with organic functional groups bonded to the main chain of polysiloxane. Can do. In the present invention, any of modified silicones having these structures can be suitably used, and among these, side chain type modified silicones are preferably used.

  In the present invention, only one type of modified silicone having the above structure may be used, or two or more types may be mixed and used.

The organic functional group is not particularly limited as long as it can impart a desired releasability to the thermal transfer image-receiving sheet of the present invention. Such organic functional groups are broadly classified into reactive functional groups having reactivity and non-reactive functional groups having no reactivity. In the present invention, the reactive functional groups and the non-reactive groups are used. Any functional group can be suitably used.
Examples of the reactive functional group used in the present invention include amino groups (including primary amino groups and secondary amino groups), epoxy groups, carboxyl groups, carbinol groups, mercapto groups, and (meth) acrylic groups. Can give.
Examples of the non-reactive functional group used in the present invention include a polyether group, a methyl styryl group, an alkyl group, a higher fatty acid ester group, a fluorine-containing functional group (such as a fluorinated alkyl group). it can.

  The modified silicone used in the present invention may be one in which one type of organic functional group is bonded, or one in which two or more types of functional groups are bonded. The modified silicone bonded with two or more types may be one in which only a reactive functional group is bonded, or may be one in which a reactive functional group and a non-reactive functional group are bonded. . Among these, in the present invention, it is preferable to use a modified silicone to which a reactive functional group is bonded, and it is particularly preferable to use a modified silicone in which a reactive functional group and a non-reactive functional group are bonded.

  As the modified silicone used in the present invention, a silicone-modified polymer grafted or blocked on an organic condensation polymer or an addition polymer (for example, polyolefin, polyester, acrylic, ethylene vinyl acetate) can also be used. By using such a silicone-modified polymer, there is an advantage that compatibility with a binder resin described later can be improved.

  Specific examples of the high molecular weight silicone suitably used in the present invention include dimethyl silicone, methylphenyl silicone, acrylic modified silicone bonded with (meth) acrylic groups, polyester modified silicone, and polypropylene modified silicone bonded with polypropylene groups. be able to.

  The content of the high molecular weight silicone contained in the receiving layer in the present invention is not particularly limited as long as the desired release stability can be imparted to the thermal transfer image-receiving sheet of the present invention. What is necessary is just to determine suitably according to the kind etc. of the low molecular weight modified silicone mentioned later. Among them, the content of the high molecular weight silicone in the present invention is preferably in the range of 0.1 to 10 parts by weight, particularly 0.5 parts by weight with respect to 100 parts by weight of the binder resin contained in the receiving layer. Within the range of ˜3 parts by weight is preferred.

  Further, the ratio between the content of the high molecular weight silicone in the receiving layer and the content of the low molecular weight modified silicone described later is a range in which desired release properties and release stability can be imparted to the thermal transfer image-receiving sheet of the present invention. If it is in, it will not specifically limit, What is necessary is just to determine suitably according to the kind of high molecular weight silicone and low molecular weight modified silicone, the kind of binder resin, etc. In particular, in the present invention, the mass ratio of the high molecular weight silicone to the low molecular weight modified silicone in the receptor layer (mass of high molecular weight silicone: mass of low molecular weight modified silicone) is in the range of 1: 4 to 4: 1. In particular, the range of 1: 3 to 3: 1 is preferable, and 1: 1 is particularly preferable.

(2) Low molecular weight modified silicone Next, the low molecular weight modified silicone used in the present invention will be described. As described above, the low molecular weight modified silicone used in the present invention has a function of mainly reducing the surface energy of the receiving layer and improving the releasability of the thermal transfer image receiving sheet of the present invention, and has a kinematic viscosity. it is to being in the range of 100mm ² / s~10 ten thousand mm ² / s.
In the present invention, the kinematic viscosity of the low molecular weight modified silicone is defined as described above, which is a silicone that is not organically modified. If the kinematic viscosity is less than 100 mm ² / s, the kind of the high molecular weight silicone described above, etc. Depending on the case, the low molecular weight modified silicone may bleed out from the receiving layer during the transfer of the dye. On the other hand, if the kinematic viscosity is 100,000 mm ² / s or more, the binder resin contained in the receiving layer This is because there is a possibility that desired releasability cannot be imparted to the thermal transfer image-receiving sheet of the present invention depending on the kind of the toner.
The kinematic viscosity of the low molecular weight-modified silicone in the present invention, is not particularly limited as long as it is within the above range, preferably in the range of inter alia 300mm ² / s~5 ten thousand mm ² / s , particularly preferably in the range of 1000mm ² / s~3 ten thousand mm ² / s. The kinematic viscosity of the low molecular weight modified silicone in the present invention is a value at a temperature of 25 ° C. unless otherwise specified. Further, the method for measuring the kinematic viscosity is the same as the method for measuring the kinematic viscosity of the high molecular weight silicone described above, and thus the description thereof is omitted here.

  The low molecular weight modified silicone used in the present invention is not particularly limited as long as it has a polysiloxane structure having an organic functional group. The structure and organic functional group of such a low molecular weight modified silicone are the same as those described in the above section “(1) High molecular weight silicone”, and thus the description thereof is omitted here.

  Only one kind of low molecular weight modified silicone used in the present invention may be used, or two or more kinds may be mixed and used.

  Specific examples of the low molecular weight modified silicone used in the present invention include a modified silicone in which a polyether group and an amino group are bonded, polyether modified silicone, Examples thereof include epoxy-modified silicone. In the present invention, polyether-modified silicone is particularly preferably used among the above-described modified silicone oils. The polyether group of the polyether-modified silicone is partially decomposed by heat (180 ° C. or more) during extrusion, but the remaining polyether group can maintain a compatibility with the binder resin described later, so that Further, bleeding out at the time of extrusion film formation, heat setting after stretching, and dye transfer is moderately suppressed. For this reason, as a result of the presence of silicone in a balanced manner on the surface of the receiving layer, it is possible to impart good releasability to the receiving layer.

  The content of the low molecular weight modified silicone contained in the receiving layer in the present invention is not particularly limited as long as it is within a range capable of imparting a desired release property to the thermal transfer image receiving sheet of the present invention. High molecular weight silicone and low molecular weight What is necessary is just to determine suitably according to the kind etc. of modified silicone. In particular, in the present invention, the content of the low molecular weight modified silicone is preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin contained in the receiving layer, and more preferably 0.5 to 0.5 parts by weight. Within the range of parts by weight to 3 parts by weight is preferred.

(3) Binder resin Next, the binder resin used for the said receiving layer is demonstrated. The binder resin used in the present invention mainly has a function of imparting self-supporting property to the receiving layer in the present invention.

  The binder resin used in the present invention preferably has a glass transition temperature in the range of 50 ° C to 100 ° C, and more preferably in the range of 70 ° C to 85 ° C.

  Further, the molecular weight of the binder resin used in the present invention may be arbitrarily determined according to various physical properties required for the thermal transfer image-receiving sheet of the present invention and constituent materials of the thermal transfer sheet used at the time of printing. (Mw) is preferably 11,000 or more, particularly preferably 15000 or more. When the weight average molecular weight of the binder resin is lower than the above range, the elastic modulus and heat resistance of the receiving layer are lowered, and it may be difficult to ensure the releasability between the thermal transfer sheet and the thermal transfer image receiving sheet of the present invention. Because. Moreover, it is because the adhesiveness with the base material sheet mentioned later may deteriorate when a weight average molecular weight is larger than the said range. In addition, the said weight average molecular weight in this invention can be calculated | required by GPC method, for example.

  Specific examples of the binder resin used in the present invention include polyolefin resins such as polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, halogenated polymers such as polyvinylidene chloride, polyvinyl acetate, and ethylene-vinyl acetate. Copolymers, vinyl polymers such as polyacrylic esters, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, copolymers of olefins such as ethylene and propylene, and other vinyl monomers, Examples include cellulose resins such as ionomers and cellulose diacetates, polycarbonate resins, phenoxy resins, epoxy resins, polyvinyl acetal resins, polyvinyl alcohol resins, and tackifier resins. Known as resin modifiers, for example, hydrogenated petroleum resins, aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, aromatic hydrocarbon resins, rosin resins, terpene resins, Examples thereof include a malon indene resin.

  In the present invention, one kind of resin may be used as the binder resin, or two or more kinds of resins may be mixed and used.

  In the present invention, it is preferable to use a polyester-based resin as the binder resin, and it is most preferable to use an amorphous polyester resin because of its high dye dyeing property.

The amorphous polyester resin is not particularly limited as long as it is substantially amorphous. As an amorphous polyester resin used for this invention, the polyester resin which has a terephthalic acid and ethylene glycol as a main component and contains the other acid component and / or other glycol component as a copolymerization component can be mentioned, for example.
Examples of the other acid component include aliphatic dibasic acids (for example, adipic acid, sebacic acid, azelaic acid) and aromatic dibasic acids (for example, isophthalic acid, diphenyldicarboxylic acid, 5-tert-butyl). Isophthalic acid, 2,2,6,6-tetramethylbiphenyl-4,4-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,1,3-trimethyl-3-phenylindene-4,5-dicarboxylic acid) Etc.
Examples of the glycol component include aliphatic diols (for example, neopentyl glycol, diethylene glycol, propylene glycol, butanediol, hexanediol), alicyclic diols (for example, 1,4-cyclohexanedimethanol), or aromatic diols (for example, , Xylylene glycol, bis (4-β-hydroxyphenyl) sulfone, 2,2- (4-hydroxyphenyl) propane derivative) and the like.

  Moreover, as binder resin used for this invention, what added the polymer (resin) which has an epoxy group and a carbodiimide group to the said amorphous polyester resin can also be used. Such a binder resin can improve the extrusion processability in the high temperature range and the heat resistance of the receiving layer, because the polymer containing the epoxy group or carbodiimide group undergoes a crosslinking reaction with the polyester resin. It has the advantage that the releasability of the high printing energy part at the time of printing can be improved.

  Examples of the polymer having an epoxy group include esters of methacrylic acid or acrylic acid and various glycidyl alcohols, for example, methyl glycidyl ester, butyl glycidyl ester, polyethylene glycol diglycidyl ester, polypropylene glycol diglycidyl ester, Examples thereof include neopentyl glycol diglycidyl steal.

  Moreover, as a polymer which has the said carbodiimide group, the Nisshinbo Co., Ltd. carbodilite (HMV-8CA) etc. can be used, for example.

(4) Other compounds The receiving layer in the present invention may contain other compounds in addition to the binder resin, the high molecular weight silicone, and the low molecular weight modified silicone. Hereinafter, other compounds used in the receiving layer will be described.

(Wax)
The receiving layer in the present invention may contain waxes for the purpose of improving thermal sensitivity, thermal transferability and abrasion resistance. Examples of such waxes include waxy fatty acid amides, various lubricants, synthetic waxes such as paraffin wax, natural waxes such as candelilla wax and carnauba wax, and oils such as silicone oil and half-loroalkyl ether. It can be improved by the addition of a kind. In addition to polyethylene resins and phosphate esters, other resins such as silicone resins, tetrafluoroethylene resins and fluoroalkyl ether resins, and inorganic lubricants such as silicon carbide and silica can also be used.

(Curing agent)
A curing agent may be added to the receiving layer in the present invention. The curing agent reacts with active hydrogen in the receptor layer and is used to crosslink and cure the receptor layer. By using the curing agent, heat resistance can be imparted to the receptor layer.

  The curing agent used in the present invention is not particularly limited as long as desired heat resistance can be imparted to the receptor layer. Usually, isocyanates, chelate compounds and the like are used, and among them, non-yellowing type isocyanate compounds are used. It is preferable to use it. Specific examples include xylylene diisocyanate (XDI), hydrogenated XDI, isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDl) and their adducts / burettes, oligomers and prepolymers.

  In the present invention, a catalyst may be added as a reaction aid for the isocyanate compound. In this case, a known catalyst can also be used as the reaction aid used in the present invention. A typical catalyst is a tin-based catalyst di-n-butyltin dilaurate (DBTDL). In addition, dibutyltin fatty acid salt catalysts, monobutyltin fatty acid salt catalysts, monooctyltin fatty acid salt catalysts, dimers thereof, and the like are effective, and the reaction rate increases as the amount of tin per weight increases. Therefore, what is necessary is just to select a kind, a combination, and an addition amount according to the isocyanate compound to be used. When a block type isocyanate compound is used, it is also effective to use a block separation catalyst.

(UV absorber and light stabilizer)
A UV agent and a light stabilizer may be used for the receiving layer in the present invention. The UV absorber and the light stabilizer that can be used in the present invention are not particularly limited as long as they have a function of improving the light resistance of a thermal transfer print formed using the thermal transfer image-receiving sheet of the present invention. As UV absorbers and light stabilizers used in the present invention, JP-A Nos. 59-158287, 63-74666, 63-145089, 59-196292, 62-229594, 63- Examples of the compounds described in JP-A Nos. 122596, 61-283595, and JP-A-1-204788, and compounds that improve the image durability in photographs and other image recording materials may be mentioned.

(Filler)
The receiving layer in the present invention may contain a filler. The filler that can be used in the present invention has a function of improving the slipperiness of the thermal transfer sheet by being contained in the receiving layer, and can impart desired high-speed printing characteristics to the thermal transfer image-receiving sheet of the present invention. There is no particular limitation. In the present invention, general inorganic fine particles and organic resin particles can be used as the filler.

  Examples of the inorganic fine particles include silica gel, calcium carbonate, titanium oxide, acidic clay, activated clay, and alumina. Examples of the organic fine particles include resin particles such as fluororesin particles, guanamine resin particles, acrylic resin particles, and silicon resin particles. The content of these fillers can be arbitrarily determined according to the specific gravity of the filler.

(Pigment)
The pigment that can be used in the present invention is not particularly limited as long as it has a function of improving the image quality formed by the thermal transfer image-receiving sheet of the present invention by being contained in the receiving layer. Examples of the pigment used in the present invention include titanium white, calcium carbonate, zinc oxide, barium sulfate, silica, talc, clay, kaolin, activated clay, and acid clay. The addition amount of such a pigment can be arbitrarily determined and used within a range not impairing the object of the present invention.

(Plasticizer)
The plasticizer that can be used in the present invention is not particularly limited as long as it has a function of improving the diffusibility of the dye in the receiving layer by being contained in the receiving layer. Examples of the plasticizer used in the present invention include phthalic acid esters, trimellitic acid esters, adipic acid esters, other saturated or unsaturated carboxylic acid esters, citric acid esters, epoxidized soybean oil, and epoxidized linseed oil. And epoxy stearic acid epoxies, orthophosphoric acid esters, phosphorous acid esters, glycol esters and the like. The content of these plasticizers can be arbitrarily determined in accordance with the type of plasticizer and the like as long as the object of the present invention is not impaired.

(Release agent)
The receptor layer in the present invention may contain a release agent in addition to the high molecular weight silicone and the low molecular weight modified silicone. As the mold release agent used in the present invention, for example, phosphate ester compounds, fluorine compounds, and other mold release agents known in the art can be used.

(5) Receiving layer The receiving layer in the present invention may be a single layer or a plurality of layers of two or more as required. In the case of a plurality of layers, layers having the same composition or the like may be stacked, or layers having different compositions may be stacked.

The thickness of the receiving layer in the present invention can be arbitrarily determined according to the use of the thermal transfer image-receiving sheet of the present invention, but is usually preferably in the range of 0.5 μm to 50 μm, particularly in the range of 1 μm to 20 μm. Is preferred. If the thickness of the receiving layer is less than the above range, the mechanical strength of the receiving layer is low, and there is a possibility that "cracking" or "tearing" may occur. This is because it may be difficult to form a layer.
Here, when the receiving layer is formed by laminating two or more layers, the above thickness range covers the total thickness.

2. Next, the base sheet used in the present invention will be described. The base sheet used in the present invention has a function of supporting the receiving layer formed on the base sheet and expressing the self-supporting property of the thermal transfer image receiving sheet of the present invention.

The substrate sheet used in the present invention is not particularly limited as long as it has a desired self-supporting property, mechanical strength, and the like according to the application of the thermal transfer image-receiving sheet of the present invention. Examples of such a base sheet include condenser paper, glassine paper, sulfuric acid paper, or high-size paper, synthetic paper (polyolefin-based, polystyrene-based), high-quality paper, art paper, coated paper, cast-coated paper, Wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivative, Polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyether resin Possible phone, tetrafluoroethylene-perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene-ethylene, tetrafluoroethylene-hexafluoropropylene, polychlorotrifluoroethylene, that films such as polyvinylidene fluoride are exemplified.
In addition, as the base sheet used in the present invention, a white opaque film formed by adding a white pigment or a filler to these synthetic resins, or a foamed foam sheet can be used.
Furthermore, the base material sheet used in the present invention may be a laminate of any combination of the above base material sheets.

  In the present invention, it is particularly preferable to use pulp paper such as fine paper, art paper, coated paper, cast coated paper among the above-mentioned base sheet. It is because cost reduction etc. are attained by using such a pulp paper.

  The thickness of the base material sheet used for this invention is about 10-300 micrometers normally.

  Moreover, when the adhesiveness of the said base material sheet and the layer provided on it is scarce, it is preferable to perform various primer processing and corona discharge processing on the surface of a base material sheet.

3. Thermal Transfer Image Receiving Sheet The thermal transfer image receiving sheet of the present invention may have a configuration other than the receiving layer and the base sheet. Such other configurations are not particularly limited as long as a desired function can be imparted to the thermal transfer image receiving sheet of the present invention. Hereinafter, examples of other configurations that can be used in the present invention will be described in order.

(1) Heat-insulating layer The heat-insulating layer used in the present invention is usually formed between the substrate sheet and the receptor layer, and when the receptor layer is heated, the substrate sheet and the like are thermally damaged. It has the heat insulation which prevents receiving. The heat insulating layer also has a function of imparting cushioning properties to the thermal transfer image receiving sheet of the present invention and improving printing characteristics. The heat insulation layer used in the present invention usually contains a thermoplastic resin and at least one of an incompatible resin or a filler that is incompatible with the thermoplastic resin.

Examples of the thermoplastic resin used in the heat insulating layer include, for example, polyolefin resins such as polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, polyvinyl acetate, ethylene vinyl acetate copolymer, and vinyl chloride acetic acid. Vinyl copolymers, vinyl resins such as polyacrylic esters, acetal resins such as polyvinyl formal, polyvinyl butyral, polyvinyl acetal, various saturated and unsaturated polyester resins, polycarbonate resins, cellulose resins such as cellulose acetate, polystyrene, Examples thereof include styrene resins such as acrylic-styrene copolymers and acrylonitrile-styrene copolymers, polyamide resins such as urea resins, melamine resins, and benzoguanamine resins. These resins can be used by arbitrarily blending them within a range that maintains the extrusion processability and is compatible.
Especially in this invention, it is preferable to use a polyester-type resin as said thermoplastic resin. This is because the polyester resin is excellent in stretchability and has an advantage in terms of cost.

  As the polyester resin, for example, an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid or naphthalenedicarboxylic acid or an ester thereof and a glycol such as ethylene glycol, diethylene glycol, 1,4-butanediol or neopentyl glycol are combined. Mention may be made of polyester resins obtained by condensation. Typical examples of this polyester resin include polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene butylene terephthalate, polyethylene-2,6-naphthalate, and the like. These polyester resins may be homopolymers, or may be copolymers copolymerized with the third component. The copolymer has the advantage that stretchability is improved and the stretch ratio can be increased.

  The incompatible resin used in the heat insulating layer is incompatible with the thermoplastic resin, and is uniformly mixed in the thermoplastic resin in a dispersed state, and at the interface with the thermoplastic resin during stretching, There is no particular limitation as long as it is a source for causing peeling and generating voids in the voids.

As an example of an incompatible resin when the polyester resin is used as the thermoplastic resin, the polyester resin is incompatible with the polyester resin and uniformly mixed in the polyester resin in a dispersed state. There is no particular limitation as long as it becomes a source for generating voids by causing peeling at the interface with the polyester resin during stretching. Examples of such incompatible resins include polystyrene resins, polyolefin resins, polyacrylic resins, polycarbonate resins, polysulfone resins, and cellulose resins. In the said heat insulation layer, these can be used independently, and 2 or more types can also be combined and used as needed. Or moderate affinity can also be provided between polyester resins by copolymerizing these resins.
In the present invention, among the above, polystyrene resins, or polyolefin resins such as polymethylpentene, polypropylene, and cyclic olefins are preferably used.

  When the heat insulating layer is composed of a thermoplastic resin and the incompatible resin as main components, the ratio of the heat insulating plastic resin and the incompatible resin in the heat insulating layer is usually in the total amount of the resin composition of the heat insulating layer. The content of the incompatible resin is preferably in the range of 3% by mass to 40% by mass, and particularly preferably in the range of 5% by mass to 30% by mass. This is because if the content of the incompatible resin is less than the above range, a desired porosity cannot be imparted to the heat insulating layer, and heat resistance, cushioning properties, and the like may be insufficient. Further, if it is more than the above range, heat resistance and mechanical strength may be lowered.

  The heat insulating layer used in the present invention may be composed mainly of the thermoplastic resin and a filler. The filler used in this case is incompatible with the thermoplastic resin, uniformly mixed in the thermoplastic resin in a dispersed state, and causes voids by peeling at the interface with the thermoplastic resin during stretching. If it becomes a source, it will not specifically limit.

  Examples of the filler used in the present invention include inorganic fillers such as silica, kaolin, talc, calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, and titanium oxide; cross-linked polymers and organic white pigments. Organic fillers can be used. These fillers having an average particle size of about 0.5 to 3 μm are used. In particular, a silicone filler is preferable from the viewpoints of ease of interfacial peeling and sharpness of particle size distribution.

  In the heat insulating layer used in the present invention, as other components other than the thermoplastic resin, the incompatible resin, and the filler, an antistatic agent, an ultraviolet absorber, a plasticizer, a dispersant, a colorant, a compatibilizing agent. An agent or the like may be included.

  The dispersant has the effect of making the dispersion diameter of the incompatible resin finer and making the dispersion of the filler uniform, and the voids to be formed can be made finer, so that whiteness and film-forming properties can be improved. More preferable dispersing agents exhibiting the above effects include olefin polymers or copolymers having polar groups such as carboxyl groups and epoxy groups, and functional groups reactive with polyester, diethylene glycol, polyalkylene glycols, interfaces. An activator can be used. These may be used alone or in combination of two or more.

  Examples of the compatibilizer include a block copolymer, a graft copolymer, a polymer having a functional group at the terminal or side chain, and a polymer macromer having a polymerizable group at the terminal of the polymer.

In addition, the porosity of the heat insulating layer used in the present invention is not particularly limited as long as the desired heat insulating properties and cushioning properties can be realized, and can be arbitrarily determined according to the material constituting the heat insulating phase. Although it is good, it is preferably within the range of 15% to 65%. This is because if the porosity is smaller than the above range, the ratio of the porosity, which is microvoids of fine voids, is small, and the features of the heat insulating layer of the present invention such as satisfactory heat insulating properties and cushioning properties may not be exhibited. . In addition, if the porosity of the heat insulating layer is larger than the above range, the film remaining on the heat insulating layer may become thin, or the pores of fine voids may collapse, making it impossible to form microvoids. It is.
Here, the porosity (V) is a percentage of the numerical value obtained by dividing the density (ρ) of the target heat insulating layer by the density (ρ ₀ ) of the entire solid content of the resin, filler, etc. constituting the heat insulating layer. Void ratio (V) = (1−ρ / ρ ₀ ) × 100 (%). The density (ρ) of the heat insulating layer is the density of the heat insulating layer having a foam structure, and is a numerical value in a configuration including voids. On the other hand, the density (ρ ₀ ) of the entire solid content of the resin, filler and the like constituting the heat insulating layer is a density in the solid content alone without including voids. The density of the heat insulating layer having a foam structure applied in the present invention (ρ) is preferably in the range of 0.3 to 1.0 g / cm ³ .

  Although the thickness of the heat insulation layer used for this invention will not be specifically limited if it is in the range which can express desired heat insulation and cushioning properties according to the material etc. which comprise a heat insulation layer, Usually, it shall be about 10 micrometers-about 100 micrometers. . If the thickness of the heat insulating layer is thinner than the above range, there is a possibility that desired heat resistance, cushioning properties, etc. may not be expressed, and if the thickness is thicker than the above range, heat resistance and mechanical strength may be reduced. Because there is.

(2) Adhesive Layer In the thermal transfer image receiving sheet of the present invention, an adhesive layer having adhesiveness to both may be formed between the receiving layer and the base sheet. By forming such an adhesive layer, there is an advantage that it is easy to laminate the base sheet and the receiving layer.

  The adhesive constituting the adhesive layer is not particularly limited as long as it exhibits adhesion to a layer adjacent to the adhesive layer, but neck-in (the film width is narrower than the die width). It is preferable to use a resin having a small draw-down property (which is a measure of high-speed spreadability and high-speed workability). Examples of such an adhesive include high-density polyethylene, medium-density polyethylene, low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer ( EMAA), ethylene-maleic acid copolymer, ethylene-fumaric acid copolymer, ethylene-maleic anhydride copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer and other polyolefin resins; polyethylene Polyester resin such as terephthalate; ionomer resin; nylon; polystyrene, polyurethane and the like can be mentioned.

  Moreover, an acrylic resin can also be used as the adhesive. Acrylic resins that can be used as the adhesive include acrylic resins obtained by polymerizing acrylic acid (including methacrylic acid) and its derivatives acrylamide and acrylonitrile, other acrylic esters, styrene, etc. Copolymer resins with other monomers can be used. Specific examples of such acrylic resins include poly (meth) methyl acrylate, poly (meth) ethyl acrylate, poly (meth) butyl acrylate, methyl (meth) acrylate-butyl (meth) acrylate Copolymer, methyl (meth) acrylate- (meth) acrylate 2-hydroxyethyl copolymer, butyl (meth) acrylate- (meth) acrylate 2-hydroxyethyl copolymer, methyl (meth) acrylate- ( (Meth) acrylic acid 2-hydroxypropyl copolymer, methyl (meth) acrylate-butyl (meth) acrylate- (meth) acrylic acid 2-hydroxyethyl copolymer, styrene-methyl (meth) acrylate copolymer The thing which consists of a homo- or copolymer containing (meth) acrylic acid ester, such as these, is mentioned. Here, (meth) acrylic acid means acrylic acid and methacrylic acid.

  The adhesive described above may be composed of one kind of resin, or may be a mixture of a plurality of resins.

(3) Back layer A back layer may be formed on the thermal transfer image-receiving sheet used in the present invention, if necessary. The function of the back layer is not particularly limited, and a layer having a desired function can be formed according to the use of the thermal transfer image receiving sheet of the present invention.

  In the present invention, it is preferable to provide a back layer having a function of improving the transportability of the thermal transfer image-receiving sheet and a function of preventing curling as the back layer. The constituent material of the back layer having such a function is not particularly limited as long as it is a material capable of imparting desired transportability and anti-curl property to the back layer, but usually an acrylic resin, a cellulose resin, a polycarbonate resin, A resin such as a polyvinyl acetal resin, a polyvinyl alcohol resin, a polyamide resin, a polystyrene resin, a polyester resin, or a halogenated polymer is used in which a filler is added as an additive.

  The back layer is preferably formed by curing the resin with a curing agent. Such a curing agent is not particularly limited as long as it can cure the above resin, and generally known ones can be used. Among them, an isocyanate compound is preferable. This is because the back layer resin reacts with an isocyanate compound to form a urethane bond and is cured / three-dimensionalized to improve heat storage stability and solvent resistance, and also improve adhesion to the base sheet. .

  Although the addition amount of the said hardening | curing agent will not be specifically limited if it exists in the range which can provide desired hardness to the said back surface layer, Usually, the inside of the range of 1-2 is preferable with respect to 1 resin reactive group equivalent. If it is less than 1, it takes a long time to complete the curing, and heat resistance and solvent resistance may be deteriorated. It is because the malfunction that the lifetime of a working fluid is short may arise.

  The filler is not particularly limited as long as a desired slip property can be imparted to the back layer. As such a filler, an organic filler such as an acrylic filler, a polyamide filler, a fluorine filler, or polyethylene wax, or an inorganic filler such as silicon dioxide or a metal oxide can be used. In particular, in the present invention, among the organic fillers and inorganic fillers, polyamide fillers are preferable. This is because the polyamide filler has a high melting point and is thermally stable, has good oil resistance and chemical resistance, and is difficult to be dyed with a dye.

  As such a polyamide filler, a spherical filler is usually used. The average particle diameter may be arbitrarily adjusted according to the amount of filler added, etc., which will be described later. Usually, the average particle diameter is preferably in the range of 0.01 to 30 μm, particularly preferably in the range of 0.01 to 10 μm. preferable. This is because if the average particle size is smaller than the above range, the filler is hidden in the back surface layer, and it may be difficult to exhibit a sufficient slip function. Further, if the average particle size is larger than the above range, the protrusion from the back surface layer becomes large, and as a result, the friction coefficient may be increased or the filler may be lost. Moreover, as said polyamide-type filler, the mixture of the 2 or more types of polyamide-type fillers from which average particle diameter differs can also be used.

  As a constituent material of the polyamide filler, a nylon resin is preferably used. Examples of such a nylon resin include nylon 6, nylon 66, nylon 12, and the like. In the present invention, nylon 12 is preferably used. This is because nylon 12 filler is excellent in water resistance and has a relatively small change in properties due to water absorption.

  The content of the filler in the back surface layer may be determined by appropriately adjusting the content within a range in which a desired transportability can be obtained according to the constituent material of the filler to be used, the average particle size, and the like. Is preferably in the range of 0.01% by mass to 200% by mass, particularly preferably in the range of 1% by mass to 100% by mass, and more preferably in the range of 0.05% by mass to 2% by mass. The inside is preferable. This is because if the content is less than the above range, the slipperiness becomes insufficient, and there is a possibility of causing trouble such as paper jam at the time of feeding the printer. Further, if the amount is larger than the above range, it may be slippery and color misalignment or the like is likely to occur in the printed image.

  The method for forming such a back layer is not particularly limited as long as it can form a back layer with excellent planarity, and a general method can be used. Examples of such a method include a method of applying a coating solution for forming a back surface layer containing the resin, filler, and the like onto the core material and drying to form a film.

(4) Others The thermal transfer image receiving sheet of the present invention may have other configurations than those described above, if necessary. Examples of the configuration other than the above include an antistatic layer and the like.

4). Production Method of Thermal Transfer Image Receiving Sheet The production method of the thermal transfer image receiving sheet of the present invention is not particularly limited as long as it is a method capable of producing a thermal transfer image receiving sheet having the above-described configuration. For example, “B. It can be produced by the method described in the section “Manufacturing method”.

B. Method for Manufacturing Thermal Transfer Image Receiving Sheet Next, a method for manufacturing the thermal transfer image receiving sheet of the present invention will be described. The method for producing a thermal transfer image-receiving sheet of the present invention comprises a receptor layer forming step of forming a receptor layer by melt-extruding a receptor layer forming resin containing a binder resin, a high molecular weight silicone, and a low molecular weight modified silicone. And a laminating step of laminating the receiving layer formed by the receiving layer forming step and the substrate sheet, and a method of manufacturing a thermal transfer image receiving sheet having a receiving layer laminated on a substrate, the kinematic viscosity of the molecular weight silicone is 500000 mm ² / s or more, and in which kinematic viscosity of the low molecular weight-modified silicone is characterized in that in the range of 100mm ² / s~10 ten thousand mm ² / s is there.

  The method for producing a thermal transfer image-receiving sheet according to the present invention comprises the step of forming the receptor layer in the receptor layer forming resin, the thermoplastic resin, and the incompatible resin or filler incompatible with the thermoplastic resin. A receiving layer laminate in which the receiving layer and the heat insulating layer are laminated by melt coextrusion of a heat insulating layer forming resin containing at least one of the above, and the laminating step comprises the receiving layer The laminate is laminated so that the heat insulating layer of the laminate and the base sheet are adhered, and further, a stretching step of stretching the receptor layer laminate between the receptor layer forming step and the laminate step. It is preferable to have it.

Next, the manufacturing method of the thermal transfer image receiving sheet of the present invention will be described with reference to the drawings. FIG. 3 is a schematic view showing an example of the method for producing a thermal transfer image receiving sheet of the present invention. As illustrated in FIG. 3, in the method for producing a thermal transfer image receiving sheet of the present invention, the heat insulating layer forming resin 21 and the receiving layer forming resin 22 are supplied to the die head 23 through separate paths, and the outlet of the die head 23 is supplied. 24. Receiving layer film forming step of co-extruding resin 21 for forming heat insulating layer and resin 22 for forming heat receiving layer in a molten state from 24 to form a receiving layer laminate comprising receiving layer 2 and heat insulating layer 3 I and
The receptor layer laminate formed in the receptor layer forming step I is stretched longitudinally with a stretching roll 31 with a peripheral speed difference, and then subjected to a transverse stretching process with a tenter-type transverse stretching machine 32, and then A stretching process II in which the film is heated and heat-set to the extent that the material crystallizes in a state where the film is chucked to the tenter, and
The adhesive 42 is melt-extruded from the die head 41, and the base sheet 1 and the receiving layer laminate are passed between the adhesive 42, between the laminating roll 43 and the press roll 44, and pressed by both rolls. By the laminating process III to EC laminate,
A thermal transfer image-receiving sheet 12 having an adhesive layer 4, a heat-insulating layer 3 and a receiving layer 2 provided in this order on a base sheet 1 is produced, and the receiving layer forming resin has a kinematic viscosity of 500,000 mm ² / a high molecular weight silicone is s or more, and the kinematic viscosity include the low molecular weight-modified silicone is in the range of 100mm ² / s~10 ten thousand mm ² / s.

According to the method for producing a thermal transfer image-receiving sheet of the present invention, the above-mentioned receiving layer forming resin contains a high molecular weight silicone having a kinematic viscosity of 500,000 mm ² / s or more and a kinematic viscosity of 100 mm ² / s to 100,000 mm ^2. By including low molecular weight modified silicone within the range of / s, it is possible to suppress bleeding out of the low molecular weight modified silicone at the time of melt extrusion, so high productivity and excellent release properties and release stability. A thermal transfer image receiving sheet can be produced.

  The method for producing a thermal transfer image-receiving sheet of the present invention comprises a receiving layer forming step and a laminating step. Hereinafter, each of these steps will be described in detail.

1. Receiving layer film forming step First, the receiving layer film forming step in the present invention will be described. The receiving layer film forming step in the present invention is a step of forming a receiving layer by melt extrusion of a receiving layer forming resin containing a binder resin, a high molecular weight silicone, and a low molecular weight modified silicone. the kinematic viscosity of the silicone is 500000 mm ² / s or more, and in which kinematic viscosity of the low molecular weight-modified silicone is characterized in that in the range of 100mm ² / s~10 ten thousand mm ² / s is there.

  The receptor layer formed by this step may be a single layer or a receptor layer laminate in which the receptor layer and other layers are laminated. The layer is preferably formed as the above-described receptor layer laminate, and particularly preferably as the receptor layer laminate laminated with the heat insulating layer.

  In this step, the method for forming the receptor layer is not particularly limited as long as it can form a receptor layer having a uniform thickness, and a general method can be used. Examples of such a method include a T-die method or an inflation method. In addition, when forming the receiving layer laminate in this step, the film forming method includes co-extrusion by a T die such as a field block method, a multi-manifold method, a multi-slot die method, and an inflation method using a round die. A coextrusion method can be used.

  The receptor layer forming resin used in this step contains a binder resin, a high molecular weight silicone, and a low molecular weight silicone, but the binder resin, high molecular weight silicone, and low molecular weight silicone used in this step are the above-mentioned “ Since it is the same as that described in the section of “A. Thermal transfer image receiving sheet”, the description thereof is omitted here. Further, regarding the contents of the binder resin, the high molecular weight silicone, and the low molecular weight silicone in the receptor layer forming resin, the respective contents in the receptor layer described in the section “A. Thermal transfer image-receiving sheet”. The description is omitted here.

Further, in the case where a laminate in which a heat insulating layer and a receiving layer are laminated in this step is formed, the heat insulating layer forming resin used for forming the heat insulating layer is a thermoplastic resin and the thermoplastic resin. The thermoplastic resin, the incompatible resin, and the filler used in this step are those of the above-mentioned “A. Thermal transfer image receiving sheet”. Since it is the same as that described in the section, explanation here is omitted.
Further, regarding the contents of the thermoplastic resin, the incompatible resin, and the filler in the resin for forming a heat insulation layer, the contents in the heat insulation layer described in the section of “A. Thermal transfer image receiving sheet” and Since it is the same, description here is abbreviate | omitted.

2. Lamination process Next, the lamination process in the manufacturing method of the thermal transfer image receiving sheet of this invention is demonstrated. The laminating step in the present invention is a step of laminating the receiving layer formed by the receiving layer forming step and the base material sheet.

In this step, the method for laminating the receiving layer and the substrate sheet is not particularly limited as long as both methods can be laminated with a desired adhesive force. In particular, in the present invention, a method of laminating the receiving layer and the base sheet using an adhesive is suitably used. As a method of laminating using the adhesive, the adhesive is melt-extruded, the base sheet and the receiving layer are laminated, and the laminating adhesive is applied by a printing method such as gravure coating. And a method of performing wet lamination or dry lamination.
In this step, when laminating using the above-mentioned adhesive, an adhesive layer is formed on the thermal transfer image-receiving sheet obtained by the present invention.

  In this step, the adhesive surface when laminating the receptor layer and the base sheet is not particularly limited as long as both surfaces can be bonded. In particular, in the present invention, when the receptor layer is formed as a receptor layer laminate, it is preferable that another layer formed on the receptor layer adheres to the base sheet. More specifically, when forming a receiving layer laminate in which the receiving layer and the heat insulating layer are laminated in the receiving layer forming step, the heat insulating layer and the base sheet are bonded in this step. It is preferable to perform lamination.

  The material used as the adhesive is the same as the material described in the section “A. Thermal transfer image-receiving sheet”, and the description thereof is omitted here.

3. Other Steps The method for producing a thermal transfer image-receiving sheet of the present invention may have other steps in addition to the receiving layer forming step and the laminating step. Examples of such other steps include a stretching step of stretching the receptor layer formed in the receptor layer forming step. In the present invention, in the case of forming a laminate in which the receptor layer and the heat insulating layer are laminated in the receptor layer formation step, a stretching step is provided between the receptor layer formation step and the laminate step. It is preferable that they are arranged. This is because the heat insulating layer can have a desired porosity by such a stretching step.

  The method for stretching the receptor layer in the stretching step is not particularly limited as long as it can be uniformly stretched to a desired stretching ratio. For example, a method using a stretching roll as shown in FIG. The method used can be used. Further, in the stretching step, stretching in the longitudinal direction only or stretching in the lateral direction can be performed. The longitudinal and transverse biaxial stretching may be an aspect of performing transverse stretching after longitudinal stretching, may be an aspect of performing longitudinal stretching after transverse stretching, and is an aspect of performing longitudinal and transverse stretching simultaneously. Also good. Furthermore, the longitudinal stretching and the lateral stretching may be divided into several times. Moreover, it is also possible to divide and execute a part of each alternately.

  In the said extending process, it is preferable to adjust the draw ratio to 3.6 times or more and 25 times or less by area magnification, and can make the porosity of a heat insulation layer into the range of 15 to 65% by this. When the draw ratio is lower than 3.6 times, the porosity of the heat insulating layer becomes low, and the heat resistance and cushioning properties cannot be sufficiently exhibited. On the other hand, when the draw ratio exceeds 25 times, the drawing conditions are too strong, and the smoothness of the drawn film is lowered, which is not preferable. In order to adjust the stretching ratio to the above range, for example, it is necessary to appropriately adjust the surface temperature of the stretching roll and the environmental temperature of the stretching process, and the rotation speed of the stretching roll and the film traveling speed. For example, the surface temperature of the drawing roll at the time of drawing and the environmental temperature of the drawing treatment are performed at a temperature equal to or higher than the glass transition point of the resin constituting the material to be drawn and lower than the melting point. As specific temperature, it is 60-160 degreeC, for example, Preferably it is the range of 80-130 degreeC.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the technical idea described in the claims of the present invention has substantially the same configuration and exhibits the same function and effect regardless of the case. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1
Using a resin for forming a receiving layer having the following composition, a resin for forming a heat insulation layer, and a resin for forming an adhesive layer, a heat insulation layer having a thickness of 360 μm and an easy adhesion layer having a thickness of 36 μm are laminated in this order by melt extrusion. In addition, a receiving layer having a thickness of 36 μm was formed. The receptor layer thus prepared was stretched 9 times by area magnification with a biaxial stretching machine manufactured by Toyo Seiki Co., Ltd., and then heat-set at 240 ° C. for 1 minute to have a void having a fine void of 48 μm. A receiving layer / heat insulating layer / adhesive layer film was obtained.

<Receptor Layer Forming Resin (Example 1)>
-Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight-High molecular weight dimethyl silicone oil (SH-200-Kinematic viscosity 1 million mm ² / s, manufactured by Toray Dow Corning Co., Ltd.)
0.5 parts by weight Low molecular weight modified silicone oil (X-22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight

<Insulating layer forming resin>
Polyethylene terephthalate resin (KR-565, manufactured by Mitsubishi Rayon Co., Ltd.) 85 parts by weight Silicone filler (KMP-590, manufactured by Shin-Etsu Chemical Co., Ltd.) 15 parts by weight

<Adhesive layer forming resin>
-Polyester resin (SI-173, manufactured by Toyobo Co., Ltd.) 70 parts by weight-EMAA resin (Nucrel N09008C, manufactured by Mitsui DuPont Polychemical Co., Ltd.) 30 parts by weight

  Adhesive (EMAA resin (Nucrel N09008C, Nacrel N09008C, the core layer paper side of the base sheet in which 150 μm core material paper and 25 μm PET are bonded) The thermal transfer image receiving sheet of Example 1 was obtained by hot melt extrusion lamination using Mitsui DuPont Polychemical Co., Ltd.).

(Example 2)
A thermal transfer image receiving sheet of Example 2 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Example 2)>
-Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight-Ultra high molecular weight dimethyl silicone oil (SH-200-Kinematic viscosity 1 million mm ² / s, manufactured by Toray Dow Corning Co., Ltd.)
0.25 parts by weight Low molecular weight modified silicone oil (X-22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.75 parts by weight

(Example 3)
A thermal transfer image receiving sheet of Example 3 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Example 3)>
・ Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight ・ Ultra high molecular weight dimethyl silicone oil
(SH-200-kinematic viscosity 1 million mm ² / s manufactured by Toray Dow Corning Co., Ltd.)
0.75 parts by weight Low molecular weight modified silicone oil (X-22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.25 parts by weight

Example 4
A thermal transfer image receiving sheet of Example 4 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Example 4)>
・ Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight ・ Ultra high molecular weight dimethyl silicone oil (SH-200—kinematic viscosity 500,000 mm ² / s manufactured by Toray Dow Corning Co., Ltd.) 0.5 weight Part ・ Low molecular weight modified silicone oil (X-22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 part by weight

(Example 5)
A thermal transfer image receiving sheet of Example 5 was obtained by producing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Example 5)>
-Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 99.5 parts by weight-Ultra high molecular weight dimethyl silicone masterbatch (MB50-010 active Si component 50% manufactured by Dow Corning) 1 part by weight-Low molecular weight Modified silicone oil (X-22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight

(Example 6)
A thermal transfer image receiving sheet of Example 6 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Example 6)>
Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight Silicone varnish (YR3370 GE Toshiba Silicone Co., Ltd.) 0.5 parts by weight Low molecular weight modified silicone oil (X-22-3939A, Shin-Etsu) Chemical Industry Co., Ltd.) 0.5 parts by weight

(Example 7)
A thermal transfer image receiving sheet of Example 7 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Example 7)>
Polyester resin (Byron 290, manufactured by Toyobo Industries Co., Ltd.) 100 parts by weight Silicone modified acrylic resin (x-22-8171 manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight Low molecular weight modified silicone oil (X -22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight

(Example 8)
A thermal transfer image receiving sheet of Example 8 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Example 8)>
Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight Polyester modified silicone (x-22-6133, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 part by weight Low molecular weight modified silicone oil (X- 22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight

Example 9
A thermal transfer image receiving sheet of Example 9 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Resin Layer Forming Resin (Example 9)>
-Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight-Ultra high molecular weight dimethyl silicone oil (SH-200-Kinematic viscosity 1 million mm ² / s, manufactured by Toray Dow Corning Co., Ltd.)
0.5 parts by weight Low molecular weight modified silicone oil (TSF4452, GE Toshiba Silicone Co., Ltd.) 0.5 parts by weight

(Example 10)
A thermal transfer image-receiving sheet of Example 10 was obtained by preparing a thermal transfer image-receiving sheet in the same manner as in Example 1 except that the receiving layer-forming resin had the following composition.

<Receptor Layer Forming Resin (Example 10)>
-Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight-Ultra high molecular weight dimethyl silicone oil (SH-200-Kinematic viscosity 1 million mm ² / s, manufactured by Toray Dow Corning Co., Ltd.)
0.5 parts by weight Low molecular weight modified silicone oil (TSF4702, manufactured by GE Toshiba Silicones Co., Ltd.) 0.5 parts by weight

(Example 11)
A thermal transfer image receiving sheet of Example 11 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Example 11)>
・ Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight ・ Polycarbodiimide resin
(HMV-8CA, manufactured by Nisshinbo Co., Ltd.) 3 parts by weight ・ Ultra high molecular weight dimethyl silicone oil (SH-200—kinematic viscosity 1 million mm ² / s, manufactured by Toray Dow Corning Co., Ltd.)
0.5 parts by weight Low molecular weight modified silicone oil (X-22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight

(Comparative Example 1)
A thermal transfer image receiving sheet of Comparative Example 1 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Comparative Example 1)>
-Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight-Ultra high molecular weight dimethyl silicone oil (SH-200-Kinematic viscosity 1 million mm ² / s, manufactured by Toray Dow Corning Co., Ltd.)
1 part by weight

(Comparative Example 2)
A thermal transfer image receiving sheet of Comparative Example 2 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Comparative Example 2)>
-Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 99 parts by weight Ultra high molecular weight dimethyl silicone masterbatch (MB50-010 active Si component 50% manufactured by Dow Corning) 2 parts by weight

(Comparative Example 3)
A thermal transfer image receiving sheet of Comparative Example 3 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Comparative Example 3)>
-Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight-Low molecular weight modified silicone (X-22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part by weight

(Comparative Example 4)
A thermal transfer image receiving sheet of Comparative Example 4 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receptor Layer Forming Resin (Comparative Example 4)>
・ Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight ・ Ultra high molecular weight dimethyl silicone oil
(SH-200-kinematic viscosity 1 million mm ² / s manufactured by Toray Dow Corning Co., Ltd.) 5 parts by weight

(Comparative Example 5)
A thermal transfer image receiving sheet of Comparative Example 5 was obtained by preparing a thermal transfer image receiving sheet in the same manner as in Example 1 except that the receiving layer forming resin had the following composition.

<Receiving layer forming resin (Comparative Example 5)>
Polyester resin (Byron 290, manufactured by Toyobo Co., Ltd.) 100 parts by weight Low molecular weight modified silicone (X-22-3939A, manufactured by Shin-Etsu Chemical Co., Ltd.) 5 parts by weight

(Evaluation)
Next, the thermal transfer image receiving sheets of the above examples and comparative examples were evaluated as follows.

(1) Releasability <Evaluation method>
Using a sublimation transfer printer CP-400 manufactured by Canon Inc. and a thermal transfer film, using the thermal transfer image-receiving sheets of the above examples and comparative examples, printing a solid black image, and releasing properties during Y, M, C printing Was visually evaluated.

<Evaluation criteria>
The evaluation criteria for the visual evaluation are as follows.
5: Release.
4: Mold release but loud peeling sound.
3: The mold is released, but abnormal transfer is performed at less than 30%.
2: The mold is released, but abnormal transfer occurs at 30% or more.
1: Fusing with the ribbon.

(2) Print sensitivity <Evaluation method>
(Thermal transfer recording)
As a thermal transfer film, a transfer film UPC-740 for sublimation transfer printer UP-D70A manufactured by Sony Corporation is used, and the thermal transfer image-receiving sheet of the above-mentioned examples and comparative examples is used, with the dye layer and the dye-receiving surface facing each other. Thermal transfer recording was performed from the back surface of the thermal transfer film in the order of superposition, Y, M, C, and protective layer using a thermal head under the following conditions.

(Print printing A)
A gradation image was formed by thermal transfer recording under the following conditions.
-Thermal head: KYT-86-12MFW11 (manufactured by Kyocera Corporation)
-Heating element average resistance: 4412 (Ω)
・ Print density in the main scanning direction: 300 dpi
-Sub-scanning direction printing density: 300 dpi
Applied power: 0.136 (w / dot)
・ One line cycle: 6 (msec.)
Printing start temperature: 30 (° C)
Print size: 100mm x 150mm
・ Gradation printing: Using a multi-pulse test printer that can vary the number of divided pulses from 0 to 255 with a pulse length that equally divides one line period into 256 in one line period, the duty of each divided pulse The ratio is fixed at 40%, and the number of pulses per line cycle is increased in increments of 17 from 0 in 1 step, 17 in 3 steps, 34 in 3 steps, and from 0 to 255, depending on the gradation. 16 gradations from 1 step to 16 steps were controlled.
・ Transfer of protective layer: Using a multi-pulse test printer that can vary the number of divided pulses from 0 to 255 within a line period and having a pulse length obtained by equally dividing the line period into 256 lines. The duty ratio was fixed to 50%, the number of pulses per line period was fixed to 210, solid printing was performed, and the protective layer was transferred to the entire print surface.

<Evaluation criteria>
The maximum reflection density of the printed matter was measured with a visual filter using an optical reflection densitometer (Macbeth RD-918, manufactured by Macbeth).
Evaluation: ○... Maximum reflection density of 2.0 or more.
Evaluation: × ··· Maximum reflection density less than 2.0.

  The evaluation results are shown in Table 1 below.

  As shown in Table 1, according to the present invention, a thermal transfer image receiving sheet excellent in releasability and releasability can be obtained.

It is a schematic sectional drawing which shows an example of the thermal transfer image receiving sheet of this invention. It is a schematic sectional drawing which shows the other example of the thermal transfer image receiving sheet of this invention. It is the schematic which shows an example of the manufacturing method of the thermal transfer image receiving sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material sheet 2 ... Receptive layer 3 ... Heat insulation layer 4 ... Easily bonding layer 5 ... Back surface layer 10, 11 ... Thermal transfer image receiving sheet 21 ... Receptor layer forming resin 22 ... Heat insulation layer forming resin 23 ... Die head 24 ... Outlet 31 ... Stretch roll 32 ... Tenter-type lateral stretcher 41 ... Die head 42 ... Adhesive 43 ... Laminate roll 44 ... Press roll

Claims (4)

A thermal transfer image-receiving sheet comprising a base sheet and a receiving layer formed on the base sheet and containing a binder resin, a high molecular weight silicone, and a low molecular weight modified silicone,
The kinematic viscosity of the high molecular weight silicone is 500000 mm ² / s or more and a kinematic viscosity of the low molecular weight-modified silicone is characterized in that in the range of 100mm ² / s~10 ten thousand mm ² / s Thermal transfer image receiving sheet.   The mass ratio of the high molecular weight silicone to the low molecular weight modified silicone in the receiving layer (mass of high molecular weight silicone: mass of low molecular weight modified silicone) is in the range of 1: 4 to 4: 1. The thermal transfer image receiving sheet according to claim 1, wherein A receiving layer forming step of forming a receiving layer by melt-extruding a receiving layer forming resin containing a binder resin, a high molecular weight silicone, and a low molecular weight modified silicone;
A laminating step of laminating the receiving layer formed by the receiving layer forming step and the base sheet,
A method for producing a thermal transfer image receiving sheet for producing a thermal transfer image receiving sheet in which a receiving layer is laminated on a substrate,
The kinematic viscosity of the high molecular weight silicone is 500000 mm ² / s or more and a kinematic viscosity of the low molecular weight-modified silicone is characterized in that in the range of 100mm ² / s~10 ten thousand mm ² / s The manufacturing method of a thermal transfer image receiving sheet. The heat receiving layer forming resin, wherein the receiving layer forming step includes the receiving layer forming resin, the thermoplastic resin, and at least one of an incompatible resin or a filler incompatible with the thermoplastic resin. By melt coextrusion, a receiving layer laminate in which a receiving layer and a heat insulating layer are laminated is formed, and the laminating step includes a heat insulating layer of the receiving layer laminate and a base sheet. It laminates so that it may adhere | attach, and also has the extending process which extends | stretches the said receiving layer laminated body between the said receiving layer film forming process and the said laminating process, It is characterized by the above-mentioned. Manufacturing method of thermal transfer image receiving sheet.

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