JP2007130960A - Sublimation transferred image-receiving sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a conventional sublimation transferred image-receiving sheet containing a silicone-based additive often causes a blur on an image due to bleeding, and makes high-speed coating difficult because it promotes foaming during the coating. <P>SOLUTION: In this sublimation transferred image-receiving sheet in which a receiving layer with dyeing properties is provided on the substrate, a long-chain aliphatic pendant resin is contained in the receiving layer. This brings about the sublimation transferred image-receiving sheet which contains a non-silicone-based release assistant, and which has as proper releasability and printability as the conventional image-receiving sheet containing the silicone-based additive. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sublimation transfer image receiving sheet that is used while being superposed on a sublimation transfer sheet, and more particularly to a sublimation transfer image receiving sheet that is excellent in releasability from a sublimation transfer sheet during transfer and image sharpness.

  In recent years, a so-called sublimation type thermal recording system has attracted attention as a kind of full-color printing system because of its characteristics such as fidelity of color tone reproduction and high image quality. This method uses a sublimation transfer sheet (hereinafter referred to as a transfer sheet) obtained by applying a heat sublimable dye on a substrate, and a thermal head having a heating element that selectively applies a voltage according to a recording signal. And a sublimation transfer image receiving sheet (hereinafter referred to as an image receiving sheet) in which a layer having dyeability (hereinafter referred to as a receiving layer) provided on another substrate is provided, the thermal head is interposed via the transfer sheet. By applying a voltage to the heating element based on the recording information, the dye is transferred and fixed (transferred) to the receiving layer of the image receiving sheet by adhesion, adsorption, dyeing, etc., and a desired recorded image is obtained. It is a recording method to obtain.

  The receiving layer of the image receiving sheet used in this sublimation type thermal recording system is generally composed mainly of a resin having high affinity for the dye because it needs to receive and dye the dye sublimated from the transfer sheet. ing.

  As a prior art relating to the resin constituting the matrix of the receiving layer, Patent Document 1 discloses the use of a polyester resin, a polycarbonate resin, a polyvinyl butyral resin, an acrylic resin, a cellulose resin, a polystyrene resin, or the like. However, when a resin having a good dye dyeing property, which is an essential requirement for a sublimation transfer image-receiving sheet, is selected from these resins, such a resin generally has a low softening point, and thus occurs during image formation. Due to the heat of the thermal head, the receiving layer and the sublimation transfer sheet are fused, and a large peeling noise is generated at the time of peeling. In extreme cases, the receiving layer and the sublimation transfer sheet cannot be separated while being adhered. There was a problem such as.

  Therefore, in order to solve the problem of difficulty in peeling, it has been proposed to add various silicone-based additives as peeling aids, focusing on the composition of the receiving layer (see Patent Documents 1, 2, and 3). .

Japanese Patent Laid-Open No. 62-222895 Japanese Patent Laid-Open No. 02-81684 JP 2000-86862 A

  However, these silicone-based additives generally have a problem that it is easy to cause image bleeding due to bleeding, and it is easy to promote foaming at the time of coating, so that it is difficult to increase the coating speed and increase the production speed. Therefore, the development of a non-silicone release aid has been awaited.

  The present invention is intended to solve the problems of such a conventional configuration, and has a non-silicone system having good releasability and printability equivalent to an image receiving sheet containing a silicone additive. An object of the present invention is to provide a sublimation transfer image receiving sheet containing a peeling aid.

  In order to achieve the above object, the present invention provides a sublimation transfer image-receiving sheet in which a receiving layer having dye-dyeing properties is provided on a substrate, and the receiving layer contains a long-chain aliphatic pendant resin. Is.

  Examples of the long-chain aliphatic pendant resin in the present invention include A.I. A copolymer of a monomer containing a long-chain aliphatic group and a monomer containing, for example, an epoxy group; A resin having a long-chain aliphatic group-containing monomer bonded to a polymer such as polyvinyl alcohol or polyethyleneimine, and having a releasability in which the aliphatic group has 12 or more carbon atoms. Exhibits exfoliation properties when the aliphatic group has 12 or more carbon atoms.

Examples of the A-type resin include the formula (1):
CH ₂ = C (R ¹ ) COOR ²
(Wherein R ¹ is hydrogen or a methyl group, and R ² is an alkyl group, alkenyl group or alkynyl group having 12 or more carbon atoms) and a monomer containing a long-chain aliphatic group represented by the formula ( 2):
CH ₂ = C (R ³ ) COOR ⁴
An acrylic polymer having an epoxy group-containing structural unit represented by (wherein R ³ is hydrogen or a methyl group, and R ⁴ is an alkyl group, alkenyl group or alkynyl group containing an epoxy group). Can be mentioned.

  Here, the monomer compound of the above formula (1) is a (meth) acrylic acid aliphatic ester having a long chain aliphatic group having 12 or more carbon atoms, preferably 22 to 30 carbon atoms, specifically, Examples thereof include lauryl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like.

  The amount of the compound of the above formula (1) used is 30% by weight or more, usually 50 to 99.99% by weight, preferably 60 to 99.9% by weight in the monomer mixture forming the polymer. If the amount is too small, the peelability becomes worse.

  Further, the epoxy group-containing compound of the above formula (2) is an (meth) acrylic acid aliphatic ester having an epoxy group, and specifically, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, methyl glycidyl (meth) ) Acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 6-methyl-3,4-epoxycyclohexylmethyl (meth) acrylate, and the like.

  The amount of the compound of the above formula (2) used is 0.01 to 40% by weight, preferably 0.1 to 4% by weight, in the monomer mixture forming the polymer. If it is inferior and too much, the peelability is lowered.

  If necessary, for example, in order to improve heat resistance, nitrile group-containing monomers such as acrylonitrile and methacrylonitrile, and other (meth) acrylic acid alkyl esters having an aliphatic group having less than 12 carbon atoms, (meth ) Known acrylamides, mono- or diesters of maleic acid, NN-dimethylaminoethyl (meth) acrylate, NN-dimethylaminopropyl (meth) acrylate, N-vinylpyrrolidone, (meth) acryloylmonophorin, etc. It is also possible to further include a monomer.

Examples of the B type resin include at least one active hydrogen-containing polymer selected from polyvinyl alcohol, ethylene / vinyl alcohol copolymer, polyethyleneimine, and a hydroxyl group-containing cellulose derivative, and a formula (3) :
R ⁵ -NCO
A reaction product of an aliphatic group-containing isocyanate (wherein R ⁵ is an alkyl group, alkenyl group or alkynyl group having 12 or more carbon atoms) can be mentioned.

  The polyvinyl alcohol used here is a known substance, and the average degree of polymerization is in the range of 100 to 3000, preferably 150 to 2000. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. In this case, the degree of saponification is 50% or more, preferably 60 to 100%.

  An ethylene / vinyl alcohol copolymer is also a known substance, and the ethylene content is 90 mol% or less, preferably 20 to 60%. Moreover, the average degree of polymerization is 500-3000, Preferably it is 800-2500.

  Furthermore, polyethyleneimine is also a known substance, and the average molecular weight is 100 to 150,000, preferably 300 to 120,000.

  Moreover, a hydroxyl group containing cellulose derivative is also a well-known substance, The average degree of polymerization is 100-20000, Preferably it is 1000-10000. Specific examples include hydroxyethyl cellulose, hydroxypropyl cellulose, and ethyl hydroxyethyl cellulose.

On the other hand, in the aliphatic group-containing isocyanate of the above formula (3) to be reacted with these active hydrogen-containing polymers, R ⁵ is a linear aliphatic group having a carbon number of 12 or more, preferably 22 to 30 (preferably 22 to 30 carbon atoms). For example, an alkyl group or an alkenyl group). It is preferable that the number of carbon atoms is 22 or more because there is little decrease in peelability at high temperatures. Specific examples include docosanyl isocyanate, tetracosanyl isocyanate, hexacosanyl isocyanate, and octacosanyl isocyanate.

  Specific examples of the resin include, for example, Pyroyl 1050, Pyroyl 1010, Pyroyl 81, Pyroyl 406, Pyroyl HT (manufactured by Yasushi Kogyo Co., Ltd.); Ashioresin RA-40, Ashioresin RA-95HS (above, manufactured by Ashio Sangyo Co., Ltd.); and BP type manufactured by Nitto Denko Corporation.

  The amount of the long-chain aliphatic pendant resin added to the receiving layer is preferably 0.1 to 20% by weight, more preferably 1 to 10% by weight, based on the weight of the binder resin constituting the receiving layer. If it is less than 0.1% by weight, the releasability is not expressed, and if it exceeds 20% by weight, the blending ratio of the binder resin is relatively reduced, which may adversely affect the printability (transferability).

  Examples of the binder resin constituting the receiving layer of the sublimation transfer image receiving sheet according to the present invention include, for example, polyester resins, polyacrylate resins, polyvinyl acetate resins, styrene acrylate resins, polyurethane resins, and polyolefin resins. , Polystyrene resin, polyvinyl chloride resin, polyether resin, polyamide resin, polycarbonate resin, polyethylene resin, polypropylene resin, polyacrylate resin, polyacrylamide resin, polyvinyl chloride resin, polyvinyl butyral resin, polyvinyl acetoacetal resin Polyvinyl acetal resins such as vinyl chloride / vinyl acetate / vinyl alcohol copolymer resins, cellulose ester resins, polyol resins, epoxy resins, phenolic resins, melamine resins, etc. It may be obtained readily commercially.

  As a substrate for providing the receiving layer of the sublimation transfer image-receiving sheet according to the present invention thereon, a film having relatively good heat resistance, for example, polyester, polypropylene, PEEK, PEN, PET, polystyrene, polysulfone, aromatic Examples include various film base materials such as polyamide, polyimide, polycarbonate, and triacetyl cellulose, and paper base materials such as fine paper, art paper, coated paper, and cast coated paper. Among them, polyester, PEEK, PEN, aromatic polyamide, And polyimide films are preferred. Moreover, the composite base material which provided these as a core material and provided the foamed film, the non-foamed film, etc. on the single side | surface or both surfaces may be sufficient. Furthermore, if necessary, a layer imparted with plasticity and conductivity may be provided on the back surface of these base materials, and an intermediate layer or the like may be provided on the receiving layer side.

  The sublimation transfer image-receiving sheet according to the present invention has, on the at least one surface of the base material, the above-described components, and, if necessary, additives known in the art, for example, an ultraviolet absorber, an antioxidant, What added a light stabilizer, an inorganic filler, etc. is dissolved in an appropriate organic solvent or dispersed in an organic solvent or water, for example, bar coater, roll coater, air knife coater, gravure coater, screen printing method. It can be obtained by applying a reverse roll coating method or the like and then drying to form a receiving layer.

  The thickness of the receptor layer to be formed is arbitrary, but is generally 1 to 20 μm.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these.

[Examples 1-6] and "Comparative Examples 1-2"
<Production of image receiving sheet>
Biaxially stretched polypropylene on both sides of commercially available A2 coated paper (Mitsubishi Paper Co., Ltd .; thickness 110 μm; basis weight 127 g / cm ² ) via urethane adhesive (coating amount: 5 g / m ² ). A film (P4256 (trade name); manufactured by Toyobo Co., Ltd .; thickness: 40 μm) was laminated by dry lamination to obtain a substrate (support).
Further, on the biaxially stretched polypropylene film, each receiving layer forming coating solution having each composition shown in Table 1 was applied using a Mayer bar so that the coating amount was 5.0 g / m ^2. The receiving layer was formed by drying and each image receiving sheet was produced.

In Table 1, the names shown in the leftmost column mean the following materials or compounds.
Byron 200: Saturated polyester resin manufactured by Toyobo Co., Ltd. Pyroyl 1010: Long chain alkyl pendant acrylic polymer manufactured by Yushi Kogyo Co., Ltd. (solid content 10%)
Pyroyl 1050: On the other hand, an ethylene-vinyl copolymer of a long-chain alkyl isocyanate (solid content: 10%) manufactured by Yushi Kogyo Co., Ltd.
Toluene / MEK: solvent (weight ratio 1: 1)

<Evaluation of image quality>
Each image-receiving sheet according to each example, each comparative example, and the sample for evaluation (the receiving layer does not contain a long-chain aliphatic pendant resin) was cut into a size of 100 mm × 140 mm. Set a special sublimation type thermal transfer ribbon to the sublimation type thermal transfer printer CVP-G7 (trade name) manufactured by Sony Corporation, and perform gradation printing of 32 gradations on each image receiving sheet under the same conditions. The reflection density was measured using Macbeth RD-918 (trade name; manufactured by Gretag Macbeth). The evaluation was performed on the assumption that the region having a low density is changed to a region having a high density as the gray level is shifted from 1 gradation to 32 gradations. The evaluation results are shown in Table 2.
<Evaluation criteria>
A: The reflection density was equal to or higher than that of the sample for evaluation.
A: The reflection density was 95% or more and less than 100% with respect to the sample for evaluation.
X: The reflection density was less than 95% with respect to the sample for evaluation.

<Silentness during printing>
Using the printer and transfer ribbon used in the above image quality evaluation, black solids with yellow, magenta and cyan were printed at the maximum energy value, and the peeling sound at that time was confirmed and evaluated by N = 10 people. . The evaluation criteria were as follows. The results are shown in Table 2.
<Evaluation criteria>
A: I felt that everyone was not interested.
○: I felt that more than 80% of people do not care.
X: I felt that more than 80% of people were interested.

<High temperature / high humidity printability>
Using the above printer and the above transfer ribbon, a black solid print in which yellow, magenta, and cyan are stacked with maximum energy is continuously printed at a temperature of 35 ° C. and a humidity of 85%. ) Was evaluated for high temperature / high humidity printability. The evaluation criteria were as follows. The results are shown in Table 2.
<Evaluation criteria>
A: Pr ≦ 1/300
A: 1/300 <Pr ≦ 1/200.
×: 1/200 <Pr

[Comparative Example 3]
An image receiving sheet was prepared in the same manner as in Example 1 except that KF393 (trade name) (amino-modified silicone manufactured by Shin-Etsu Chemical Co., Ltd.), which is a silicone-based release material, was used instead of the pyroyl 1010 used in Example 1. Obtained.

Claims (3)

  A sublimation transfer image receiving sheet comprising a base material provided with a dye-receptive receiving layer, wherein the receiving layer contains a long-chain aliphatic pendant resin. The long-chain aliphatic pendant resin has the formula (1):
CH ₂ = C (R ¹ ) COOR ²
(Wherein R ¹ is hydrogen or a methyl group, and R ² is an alkyl group having 12 or more carbon atoms, an alkenyl group, or an alkynyl group),
Formula (2):
CH ₂ = C (R ³ ) COOR ⁴
An acrylic polymer having an epoxy group-containing structural unit represented by (wherein R ³ is hydrogen or a methyl group, and R ⁴ is an alkyl group, alkenyl group or alkynyl group containing an epoxy group). 2. The sublimation transfer image receiving sheet according to claim 1, which is a main component. The long-chain aliphatic pendant resin is at least one active hydrogen-containing polymer selected from polyvinyl alcohol, ethylene / vinyl alcohol copolymer, polyethyleneimine, and a hydroxyl group-containing cellulose derivative, and a formula (3):
R ⁵ -NCO
The sublimation transfer image-receiving sheet according to claim 1, which is a reaction product of an isocyanate (wherein R ⁵ is an alkyl group, alkenyl group or alkynyl group having 12 or more carbon atoms).