JP2006212829A - Thermal transfer accepting sheet and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accepting sheet, which is excellent in the releasability of an inkribbon even in higher speed printing and, at the same time, excellent in the adhesion to a protective layer, and its manufacturing method. <P>SOLUTION: The thermal transfer accepting sheet comprises a dye dyeable resin-containing accepting layer on at least one side of a sheet-like support, wherein the accepting layer includes a reactant of a side-chain type amino-polyether modified solicone and a polyisocyanate compound. Preferably, the polyisocyanate compound is a hexamethylisocyanate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal transfer receiving sheet (hereinafter referred to as a receiving sheet) having a receiving layer mainly composed of a dye dyeable resin. More specifically, the present invention is excellent in releasability from the ink ribbon dye layer portion even during high-speed printing, and also adheres to the ink ribbon transfer type laminate layer portion (hereinafter referred to as a protective layer). The present invention relates to an excellent receiving sheet and a manufacturing method thereof.

  In the dye thermal transfer method, an ink ribbon and a receiving sheet are superposed, a sublimable dye is transferred onto a receiving layer by heat supplied from a thermal head or the like, and then both are released to form an image. As dye-dyeing resins used for the receiving layer, polyvinyl chloride resins, polyester resins, polyvinyl butyral resins, cellulose resins, and the like have been proposed (for example, Japanese Patent Application Laid-Open No. S59-223425, special publications). (Japanese Unexamined Patent Publication Nos. 57-11137191, 61-11293, and 5-177366).

  In recent years, in order to improve image storability such as light resistance and grease resistance, an “overlaminate” method in which a protective layer is provided after sequentially transferring three-color or four-color dyes on an ink ribbon has become mainstream. (For example, Unexamined-Japanese-Patent No. 58-149048, Unexamined-Japanese-Patent No. 58-148778). In this system, the receiving layer surface of the receiving sheet needs to realize contradictory physical properties, such as releasability with respect to the dye layer portion of the ink ribbon and adhesion with respect to the protective layer portion. Vinyl chloride resins have been widely used as dye-dyeing resins that can achieve both of these physical properties. However, in recent years, their use has been avoided from the viewpoint of environmental problems such as the tendency of dioxins to be easily generated when the receiving sheet is discarded and burned. Has been.

  In order to improve the releasability between the receiving layer and the ink ribbon dye layer during thermal transfer recording, it is generally known to use a releasable substance in the receiving layer. For example, silicon-based compounds, fluorine-based compounds and the like (for example, see Patent Document 1), cured products of amino-modified silicone and epoxy-modified silicone (for example, see Patent Document 2), and the like have been proposed. Examples of amino-polyether-modified silicone oils include cured products with carboxy-modified silicone oils (see, for example, Patent Document 3 or 4). Further, in order to improve sebum resistance and writing performance of recorded images, a reaction product of a silicone-based mold release agent and an isocyanate compound (see, for example, Patent Document 5) has been proposed. Furthermore, it has also been proposed to provide a release layer in which a thermoplastic polyester resin and amino / polyether-modified silicone are mixed on the surface of the receiving layer (see, for example, Patent Document 6). However, control of these reactions is not always easy, and it is difficult to obtain stable quality.

  In recent years, sublimation printers have been shortened in print time. As a result, since the high energy is applied from the thermal head in a short time in a state where the ink ribbon and the receiving sheet are overlapped, the receiving sheet and the ink ribbon are easily fused. In such a printer, when printing is performed on a receiving layer containing the above-described known release material, an amount of the release material that realizes sufficient release properties during high-speed printing is added to the receiving layer. Therefore, there is a need for a releasable substance that easily causes “lamination adhesion failure” that deteriorates the adhesion of the protective layer, and that achieves high performance and contradictory physical properties.

JP-A-60-212394 (2nd page) JP 60-34898 A (page 4) Japanese Patent Laid-Open No. 5-3068 (page 4) JP-A-8-118820 (Page 5) Japanese Patent Laid-Open No. 7-68948 (page 3-4) JP-A-1-247196 (page 1-3)

  An object of the present invention is to improve the above-mentioned drawbacks of the prior art, and to provide a receiving sheet excellent in the peelability of the ink ribbon even during high-speed printing, and excellent in the adhesion of the protective layer, and a method for producing the same. is there.

The present invention includes the following invention names.
(1) In a thermal transfer receiving sheet in which a receiving layer containing a dye-dyeable resin is provided on at least one surface of a sheet-like support, the receiving layer reacts with a side chain amino polyether-modified silicone and a polyisocyanate compound. A thermal transfer receiving sheet comprising:
(2) The thermal transfer receiving sheet according to item (1), wherein the polyisocyanate compound is hexamethylene diisocyanate.
(3) In a method for producing a thermal transfer receiving sheet in which a receiving layer containing a dye-dyeable resin is provided on at least one surface of a sheet-like support, a side chain type amino / polyether-modified silicone and a polyisocyanate compound are mixed. After the reaction, a composition for forming a receiving layer containing the reaction product and a dye-dyeable resin is prepared, coated on a sheet-like support, and dried to form a receiving layer. A method for producing a thermal transfer receiving sheet.

  The receiving sheet of the present invention is excellent in transferability of the protective layer to the surface of the receiving layer, has no ink ribbon fusion, and is excellent in high-speed printing suitability.

  The present invention provides a receptor sheet in which a receptor layer containing a dye-dyeable resin and a release substance is provided on at least one surface of a sheet-like support, wherein the receptor layer is at least a side chain amino acid as a release substance. -It contains the reaction material of polyether modified silicone and a polyisocyanate compound, It is characterized by the above-mentioned.

  In order to satisfy the contradicting physical properties of the receptive layer surface of the receptive layer sheet, such as peelability from the ink ribbon and adhesion to the protective layer, the side chain amino polyether-modified silicone of the present invention and the polyisocyanate compound It is not clear why the reactant has an excellent effect as a releasable substance, but the polyether-modified part of the side-chain amino-polyether-modified silicone contributes to the adhesion of the protective layer, and the amino group and isocyanate. Polymerization by reaction of the group makes it easier for the silicone to bleed out to the surface of the receiving layer, and the residual isocyanate group of the polyisocyanate after the reaction reacts with the functional group of the thermoplastic resin, so that the reactant becomes the receiving layer. This is considered to be because the peeling performance is stable even after multi-color printing, being fixed to the surface layer.

  As an example of the method for producing a receiving sheet of the present invention, a side chain type amino / polyether-modified silicone and a polyisocyanate compound are mixed and reacted, and then a receiving layer containing the reaction product and a dye-dyeable resin. A receiving sheet is obtained by preparing a forming composition, applying the composition on a sheet-like support, and drying to form a receiving layer.

  The side chain type amino / polyether-modified silicone in the present invention has, for example, a polysiloxane as a main skeleton, such as the following general formulas (I) and (II), and an amino group and a polyether group in the side chain. It is what you have.

但し、上記式（Ｉ）において、Ｒ^１およびＲ^２は互いに独立に選択されたアルキレン基である。ｌ、ｍ、ｎは１〜２０００の整数、ａ、ｂは１〜３０の整数である。

However, in the above formula (I), R ¹ and R ² are alkylene groups selected independently of each other. l, m, and n are integers of 1 to 2000, and a and b are integers of 1 to 30.

但し、上記式（ＩＩ）において、Ｒ^３、Ｒ^４およびＲ^５は、互いに独立に選択されたアルキレン基である。ｌ、ｍ、ｎは１〜２０００の整数、ａ、ｂは１〜３０の整数である。

However, in said formula (II), R < ³ >, R < ⁴ > and R < ⁵ > are the alkylene groups selected mutually independently. l, m, and n are integers of 1 to 2000, and a and b are integers of 1 to 30.

  Side chain type amino / polyether-modified silicones having amino groups in the side chain have a milder reaction with polyisocyanate than terminal type amino / polyether-modified silicones having amino groups at one or both ends, and the control thereof It is easy, and when preparing a coating solution for forming a receiving layer, problems such as gelation do not occur under normal conditions. Specific examples of the side chain type amino / polyether-modified silicone include X22-3939A and X22-3908A manufactured by Shin-Etsu Chemical Co., Ltd., and BY16-893 manufactured by Toray Dow Corning Co., of course. is not.

  Examples of the polyisocyanate compound to be reacted with the modified silicone in the present invention include 2,4-toluene diisocyanate (2,4-TDI), 2,6-TDI, diphenylmethane-4,4′-diisocyanate (MDI), and hydrogenation. MDI, 1,5-naphthalene diisocyanate (NDI), tolylene diisocyanate (TODI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), hydrogenated XDI, and modified products of these polyisocyanates Specific examples include, but are not limited to, and two or more of these can be used in combination. Among these polyisocyanate compounds, hexamethylene diisocyanate, which has a relatively mild reaction with amino groups, is preferably used.

  The reaction method of the side chain amino / polyether-modified silicone and the polyisocyanate compound is not particularly limited as long as the amino group of the side chain amino / polyether modified silicone and the isocyanate group of the polyisocyanate compound can react. When a dye dyeing resin having a relatively low reactivity is used in combination, it is possible to prepare a receiving layer coating solution. As a preferred reaction method, the reaction product can be obtained by diluting each of the side chain type amino / polyether-modified silicone and the polyisocyanate compound with an appropriate solvent and then mixing them with stirring at room temperature. Of course, it is possible to heat at the time of stirring or to use a catalyst or the like in order to proceed the reaction.

  The ratio of the amino group of the side chain type amino / polyether-modified silicone used in the reaction and the isocyanate group of the polyisocyanate compound is not particularly limited, but 0.1 mol of isocyanate group per 1 mol of amino group. The above is preferable, and more preferably in the range of 1-1000 mol. If the isocyanate group is less than 0.1 mole per mole of amino group, ribbon fusion may occur during printing, while if the isocyanate group is excessive, the transferability of the protective layer may be reduced. .

  As a releasable substance in the receiving layer, the reaction product of the side chain type amino / polyether-modified silicone and the polyisocyanate compound is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the dye-dyeable resin, More preferably, it mix | blends in 0.2-10 mass parts. If the blending amount is less than 0.1 parts by mass, the effect of releasability may not be sufficiently obtained, and if it exceeds 20 parts by mass, the adhesion of the protective layer may be deteriorated.

  Further, in order to ensure the releasability between the ink ribbon and the receiving layer, a known releasable substance can be used in combination. Specifically, modified silicone oils such as dimethyl silicone oil, polyether modified silicone oil, epoxy modified silicone oil, amino modified silicone oil, carboxyl modified silicone oil, carbinol modified silicone oil, methacrylic acid modified silicone oil, and paraffin wax These include, but are not limited to, hydrocarbons such as polyethylene and fluorocarbon, fatty acids such as stearic acid, aliphatic amides, esters, alcohols, metal soaps, and natural waxes. It is not something. These releasable substances are preferably blended in the range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the dye-dyeable resin of the receiving layer, but are not particularly limited.

  Furthermore, examples of the dye dyeable resin include polyester, polyvinyl butyral, polyvinyl chloride, polyvinyl acetal, polyacetal, polyvinylidene chloride, polyvinyl acetate, polyvinyl formal, polystyrene, styrene-acrylonitrile copolymer, polyethylene, ethylene-acetic acid. Examples thereof include vinyl copolymers, polypropylene, polymethyl methacrylate, methyl methacrylate-styrene copolymers, polyamides, ethyl cellulose, cellulose acetate, propyl cellulose, acetic acid / butyric acid cellulose, cellulose nitrate, polycarbonate, phenoxy resins, and polyurethane resins. Of course, the present invention is not limited to these and can be used in combination.

  In order to further improve the releasability, it is possible to crosslink the thermoplastic resin with a crosslinking agent such as a polyisocyanate compound, an epoxy, or an organometallic compound. These crosslinking agents are preferably blended so that the number of functional groups of the crosslinking agent is about 0.1 to 1000 with respect to 1 of the functional groups of the thermoplastic resin.

  In addition, a plasticizer can be used alone or in combination for the purpose of controlling dyeability. As the plasticizer, known ones such as phthalic acid ester type, aliphatic dibasic acid ester type, trimetic acid ester type, phosphoric acid ester type, epoxy type and polyester type can be used. Preferably 1-50 mass parts is mix | blended with respect to 100 mass parts of dye dyeable resin, However, 1-30 mass parts is more preferably used from the balance of bleed-out.

  In order to further improve the light resistance, an ultraviolet absorber (hereinafter referred to as UVA) or a hindered amine light stabilizer (hereinafter referred to as HALS) can be used alone or in combination. As UVA, benzotriazole UVA, triazine UVA, oxalic anilide UVA, and benzophenone UVA are generally known, but especially benzotriazole UVA has a wider absorption wavelength range than other UVAs, Further, since it has a maximum absorption peak on the high wavelength side and has a large absorbance, it is preferably used since a particularly excellent effect is obtained when used in combination with HALS. Preferably 1-70 mass parts is mix | blended with respect to 100 mass parts of dye dyeable resin, and especially 1-40 mass parts is more preferably used from the balance of the amount of UVA input and an effect. HALS is a compound having a 2,2,6,6-tetramethylpiperidine skeleton, and is not particularly limited as long as it has this skeleton. HALS is preferably blended in an amount of 1 to 70 parts by weight with respect to 100 parts by weight of the dye-dyeable resin. In particular, the blending of 1 to 40 parts by weight is more preferably used because of the balance between the amount of HALS input and the effect.

The coating amount of the receiving layer is preferably about 1 to 12 g / m ² , more preferably ² to 10 g / m ² . Incidentally, when the coating amount of the receiving layer is less than 1 g / m ² , the receiving layer cannot completely cover the surface of the substrate, resulting in deterioration of the image quality, and the receiving layer and the ink ribbon are not heated due to the heating of the thermal head. There may be a fusing problem that causes adhesion. On the other hand, when the coating amount of the receiving layer exceeds 12 g / m ² , not only is the effect saturated and uneconomical, but also the strength of the receiving layer is insufficient, the thickness of the receiving layer increases, The heat insulation effect may not be sufficiently exhibited, and the image density may be lowered.

  As the sheet-like support of the receiving sheet, a multilayer structure base material is generally used. The substrate surface layer of the multilayer structure substrate is not particularly limited, but from the viewpoint of uniformity of printed image quality and gradation, polyethylene such as polyethylene and polypropylene, polyester such as polyethylene terephthalate, polyamide, A stretched film mainly composed of polyvinyl chloride or polystyrene, or a porous film (so-called synthetic paper) mainly composed of a thermoplastic resin such as polyolefin or polyester is used.

  As a core material layer of a multilayer structure base material, paper containing cellulose pulp as a main component, coated paper, art paper, cast paper, laminated paper provided with a thermoplastic resin layer on at least one, or synthetic resin as a main component A film or sheet of polyester, polyamide, polyolefin, polystyrene, polycarbonate, polyvinyl alcohol, polyvinyl chloride or the like is used.

  The lamination method for obtaining the multilayer structure base material is not particularly limited, but known techniques such as wet lamination, extrusion lamination, dry lamination, and wax lamination may be used. Is used. As the dry laminating adhesive, polyether-based or polyester-based adhesives can be used. The sheet-like support used in the present invention preferably has a thickness of 20 to 300 μm.

In the receiving sheet of the present invention, on the surface opposite to the receiving layer (back surface), the running property is improved, the static electricity is prevented, the image receiving layer is prevented from being damaged by rubbing between the receiving sheets, and the printed receiving sheet is stacked. In some cases, a back coating layer may be formed for the purpose of preventing dye transfer from the receiving layer to the back surface of the receiving sheet adjacent to the receiving layer. A resin as an adhesive component and various conductive agents can be added to the back coating layer for antistatic treatment. As the conductive agent, it is desirable to use a cationic polymer. As the cationic polymer, polyethyleneimine, an acrylic polymer containing a cationic monomer, a cation-modified acrylamide polymer, a cationic starch, or the like can be generally used. The coating amount of the back coating layer is preferably in the range of 0.3 to 10.0 g / m ² .

In order to prevent static electricity and improve whiteness, an intermediate layer containing various known conductive agents, white pigments, fluorescent dyes and the like can be provided between the sheet-like support and the receiving layer. is there.
Furthermore, it is of course possible to use it as a so-called seal type receiving sheet in which an adhesive layer, a release agent layer, a base sheet layer and the like are sequentially provided on the back side of the receiving sheet.

  The receiving layer and other coating layers of the receiving sheet of the present invention use a coater such as a bar coater, gravure coater, blade coater, air knife coater, gate roll coater, curtain coater, die coater, lip coater, and slide bead coater. Can be applied and dried.

  The present invention will be described in more detail with reference to the following examples, but the present invention is of course not limited thereto. In the examples, “parts” and “%” all indicate “parts by mass” and “% by mass”.

"Reaction of Side-Chain Polyether Amino-Modified Silicone with Polyisocyanate Compound"
<Reaction Example 1>
After mixing the following materials, the mixture was stirred at 25 ° C. for 1 hour to obtain a silicone reactant A.
Side chain polyether amino modified silicone (trade name: X-22-3939A,
Manufactured by Shin-Etsu Chemical Co., Ltd.) 2 parts polyisocyanate compound (trade name: NY-710A, manufactured by Mitsubishi Chemical Corporation)
Hexamethylene diisocyanate) 8 parts methyl ethyl ketone / toluene (mass ratio: 1/1) 90 parts

<Reaction example 2>
After the following materials were mixed, the mixture was stirred at 25 ° C. for 1 hour to obtain a silicone reactant B.
Side chain polyether / amino-modified silicone (trade name: BY16-893,
2 parts polyisocyanate compound (trade name: NY-710A, manufactured by Mitsubishi Chemical Corporation)
Hexamethylene diisocyanate) 8 parts methyl ethyl ketone / toluene (mass ratio: 1/1) 90 parts

<Reaction Example 3>
After mixing the following materials, the mixture was stirred at 25 ° C. for 1 hour to obtain a silicone reactant C.
Side chain polyether amino modified silicone (trade name: X-22-3939A,
2 parts polyisocyanate compound (trade name: D-170, manufactured by Mitsui Takeda Chemical Co., Ltd.)
Hexamethylene diisocyanate trimer) 8 parts methyl ethyl ketone / toluene (mass ratio: 1/1) 90 parts

<Reaction Example 4>
After mixing the following materials, the mixture was stirred at 25 ° C. for 1 hour to obtain a silicone reactant D.
Amino-modified silicone (trade name: KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) 2 parts polyisocyanate compound (trade name: NY-710A, manufactured by Mitsubishi Chemical Corporation)
Hexamethylene diisocyanate) 8 parts methyl ethyl ketone / toluene (mass ratio: 1/1) 90 parts

<Reaction Example 5>
After mixing the following materials, the mixture was stirred at 80 ° C. for 24 hours to obtain a silicone reactant E.
Alcohol-modified silicone (trade name: X-22-4015, manufactured by Shin-Etsu Chemical Co., Ltd.) 5 parts polyisocyanate compound (trade name: Coronate HL, manufactured by Nippon Polyurethane Co., Ltd.)
Polyfunctional polyisocyanate) 5 parts water 0.1 part methyl ethyl ketone / toluene (mass ratio: 1/5) 40 parts

"Creating a receiving sheet"
Example 1
A multilayer structure film (trade name: YUPO FPG50, manufactured by YUPO Corporation) having a main component of biaxially stretched polypropylene is laminated on both surfaces of a high-quality paper having a thickness of 100 μm by a dry lamination method, and a sheet-like support did. After coating and drying (120 ° C., 1 minute) the following receiving layer coating solution on one side of the sheet-like support so that the solid content coating amount is 5 g / m ² , it is further reduced to 4 at 50 ° C. A receiving sheet was prepared by heat treatment for a day.
"Coating fluid for receiving layer"
Polyester resin (trade name: Byron 200, manufactured by Toyobo Co., Ltd.) 100 parts silicone reactant A 3 parts polyisocyanate (trade name: Takenate D-110N, manufactured by Mitsui Takeda Chemical Co., Ltd.,
Xylene diisocyanate adduct body) 5 parts toluene 300 parts

Example 2
A receiving sheet was prepared in the same manner as in Example 1 except that the silicone reactant B was used in place of the silicone reactant A in the formulation of the coating solution for the receiving layer.

Example 3
A receiving sheet was prepared in the same manner as in Example 1 except that the silicone reactant C was used in place of the silicone reactant A in the formulation of the receiving layer coating solution.

Comparative Example 1
In the formulation of the coating solution for the receiving layer, a receiving sheet was prepared in the same manner as in Example 1 except that polyether silicone (trade name: KF-351, manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of the silicone reactant A. Created.

Comparative Example 2
Example 1 except that amino-modified silicone (trade name: KF-393, manufactured by Shin-Etsu Chemical Co., Ltd., side chain amino group type) was used in place of the silicone reactant A in the formulation of the coating solution for the receiving layer. A receiving sheet was prepared in the same manner as above.

Comparative Example 3
A receiving sheet was prepared in the same manner as in Example 1 except that the silicone reactant D was used in place of the silicone reactant A in the formulation of the coating solution for the receiving layer.

Comparative Example 4
A receiving sheet was prepared in the same manner as in Example 1 except that the silicone reactant E was used instead of the silicone reactant A in the formulation of the coating solution for the receiving layer.

Evaluation The receiving sheets obtained in each of the above Examples and Comparative Examples were evaluated for protective layer transferability, printing paper discharge property, and the like. The obtained results are shown in Table 1.

[Protective layer transfer energy test]
Using a thermal transfer tester (trade name: TH-PMI2, manufactured by Okura Electric Co., Ltd.), changing the applied energy, the protective layer portion of the sublimation thermal transfer ribbon (trade name: UP-540, manufactured by Sony Corporation) is used as the receiving sheet. The minimum energy at which the protective layer can be sufficiently adhered was evaluated.
In this protective layer transferability test, if the minimum protective layer transfer energy is 1 mj / dot or less, the transferability level has no practical problem.

[Printing paper discharge]
Using a commercially available thermal transfer video printer (trade name: UP-50, manufactured by Sony Corporation) and a sublimation type thermal transfer ribbon (trade name: UP-540, manufactured by Sony Corporation), printing is performed on the receiving layer portion of the receiving sheet, and 50 ° C. Under the environment, ten black solids were printed continuously. At that time, the sheet discharge property of the receiving sheet was evaluated according to the following criteria.
◯: There is no fusion between the receiving sheet and the ribbon, and all 10 sheets are discharged normally and are sufficiently suitable for practical use.
X: One or more fusings between the receiving sheet and the ribbon occur, and the sheet is not discharged normally and is not suitable for practical use.

[Protective layer transfer appearance evaluation]
In the actual print suitability test using the above-mentioned commercially available thermal transfer video printer, the appearance of the protective layer on the surface of the image-forming receiving layer was visually evaluated according to the following criteria.
○: The protective layer is satisfactorily transferred and adhered, and there is no practical problem.
X: The protective layer is not sufficiently transferred and adhered, and there is a problem in practical use.

The receiving sheet of the present invention has excellent protective layer transferability and high-speed printing suitability, and can be used in a thermal transfer type full-color printer such as a sublimation thermal transfer method. Although it is particularly suitable for the “overlamination” method, it can of course be applied to other dye thermal transfer receiving layers and contributes greatly to the industry.

Claims (3)

  In a thermal transfer receiving sheet in which a receiving layer containing a dye-dyeable resin is provided on at least one surface of a sheet-like support, the receiving layer contains a reaction product of a side chain amino / polyether-modified silicone and a polyisocyanate compound. A thermal transfer receiving sheet.   The thermal transfer receiving sheet according to claim 1, wherein the polyisocyanate compound is hexamethylene diisocyanate. In a method for producing a thermal transfer receiving sheet in which a receiving layer containing a dye-dyeable resin is provided on at least one surface of a sheet-like support, a side chain type amino / polyether-modified silicone and a polyisocyanate compound are mixed and reacted. Then, a composition for forming a receiving layer containing the reaction product and a dye-dyeable resin is prepared, applied to a sheet-like support, and dried to form a receiving layer. A method for producing a receiving sheet.