JP4402227B2 - Transfer sheet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transfer sheet, particularly when the base material is an amorphous polyethylene terephthalate resin sheet, and the surface of the transfer target has a three-dimensional shape with irregularities. Further, the present invention relates to a transfer sheet that can be satisfactorily transferred by the transfer sheet being deformed following the shape of an object to be transferred at the time of transfer or prior to transfer.
[0002]
[Prior art]
There are several methods for patterning the surface of industrial products, but instead of patterning those products directly, once a temporary base sheet is patterned, a transfer sheet is constructed, A so-called transfer is often performed in which a pattern is transferred by applying the obtained transfer sheet to a product.
[0003]
As a base sheet of such a transfer sheet, paper, plastic sheet, metal foil, etc. can be used, and it is properly used depending on the application, but a plastic sheet, particularly a polyethylene terephthalate resin sheet, should be used as the base sheet. There are many. The reason for this is that when transferring the pattern on the transfer sheet to the transfer target, prepare a sheet with a heat-sensitive adhesive layer on the surface of the pattern layer, and use the transfer machine to make a base sheet for the transfer sheet. In many cases, a polyethylene terephthalate resin sheet is used as a versatile resin sheet from the viewpoint of heat resistance and mechanical strength required for the base sheet. By being suitable.
The heat-sensitive adhesive layer is used because effective adhesiveness can be obtained in a short time with respect to a plastic molded article that occupies a considerable proportion of the transfer target.
[0004]
The transfer sheet whose base material sheet is a polyethylene terephthalate resin sheet can be easily applied to the surface of the transfer target being flat, and a special transfer machine is used for the primary curved surface such as the side of a cylinder. It is necessary to do this, but it can be applied as it is.
However, when a transfer sheet whose base sheet is a polyethylene terephthalate resin sheet is tried to be transferred on a three-dimensional transfer target having projections and depressions on the surface, the base sheet is those Since the three-dimensional shape cannot be followed, a portion that cannot be transferred is generated.
[0005]
Conventionally, as a method of transferring to an object to be transferred having irregularities, a method of once forming a pattern on a sponge-like pad, printing on a water-soluble to water-swellable film, and floating the print film in water, There is also a method of pressing a transfer target in a state where the base sheet is dissolved or sufficiently softened and using a water pressure to stir the printed film.
However, in these methods, the deformation of the pattern cannot be controlled, the pattern to be transferred is not constant, and printing as intended is difficult.
[0006]
[Problems to be solved by the invention]
In the present invention, the substrate sheet is a polyethylene terephthalate resin sheet, avoiding the disadvantages of the transfer sheet, and the conventional method used as a means for transferring to a transfer target having irregularities is as intended. The problem is to avoid the drawbacks that are difficult to transfer.
[0007]
[Means for solving the problems]
The above problem uses a transfer sheet in which the base sheet reliably holds the pattern until the transfer, but by using an amorphous polyethylene terephthalate resin sheet as the base sheet of the transfer sheet, I was able to solve it.
[0008]
1st invention has the peelable base material sheet which has a peelable surface on the surface, and the transfer layer laminated | stacked on the said peelable surface so that peeling is possible, For comprising the said peelable base material sheet The base sheet is an amorphous polyethylene terephthalate resin sheet, the transfer layer is a pattern layer, and a protective layer that protects the pattern layer that becomes the uppermost layer after transfer to the peelable base sheet side of the pattern layer. The transfer sheet is characterized in that it is laminated and the protective layer is made of a thermosetting resin or an ionizing radiation curable resin composition. A second invention is characterized in that, in the first invention, the peelable substrate sheet is obtained by laminating a peelable layer on the surface of the amorphous polyethylene terephthalate resin sheet on the protective layer side. It relates to a transfer sheet. According to a third invention, in the first or second invention, the transfer layer is formed by laminating an adhesive layer for adhering to an object to be transferred on the side of the pattern layer opposite to the peelable substrate sheet. The present invention relates to a transfer sheet. A fourth invention relates to a transfer sheet according to any one of the first to third inventions, wherein the protective layer is made of a thermosetting resin using a polyurethane resin. A fifth invention relates to a transfer sheet according to any one of the first to third inventions, wherein the protective layer is formed by adding a thermoplastic resin to an ionizing radiation curable resin composition. is there.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The sectional structure of the transfer sheet of the present invention will be described with reference to FIG. 1. The transfer sheet 1 has a structure in which a transfer layer 20 is laminated on the lower surface of a peelable substrate sheet 10.
Among these, the peelable substrate sheet 10 has a structure in which the peelable layer 12 is laminated on the lower surface of the substrate sheet 11, and the transfer layer 20 is a pattern layer that is a main element constituting the transfer layer 20. 21, a protective layer 22 thereon, and an adhesive layer 23 under the pattern layer 21 are laminated together.
[0010]
Since the peelable substrate sheet 10 only needs to have a peelable bottom surface, the peelable layer 12 can be omitted in consideration of the material of the transfer layer.
The protective layer 22 protects the pattern transferred to the surface of the transfer target by transfer, and can be omitted depending on the application.
The adhesive layer 23 is for adhering the pattern layer 21 and the protective layer 22 to an object to be transferred when accompanied by the pattern layer 21 and the protective layer 22.
The above is related to the basic structure of the transfer sheet, and there can be various other modifications. In any case, the sectional structure of the transfer sheet itself is known, and the present invention May take their known structure.
[0011]
The characteristic point of the transfer sheet 1 of the present invention is that an amorphous polyethylene terephthalate resin sheet is used as the base sheet.
In the present invention, “non-crystalline” of the non-crystalline polyethylene terephthalate resin sheet does not cause deterioration in physical properties due to recrystallization even when heat treatment is performed again. The thing which does not have a sex component. The crystallinity is measured according to JIS K7121.
[0012]
Specifically, using a DSC-50 manufactured by Shimadzu Corporation, the temperature was raised from 30 ° C. to 280 ° C. at a rate of 10 ° C. per minute, and then cooled to 30 ° C. at a rate of 10 ° C. per minute. When the temperature is increased again at the same temperature increase rate as described above, the case where no melting peak occurs is referred to as non-crystalline.
[0013]
The amorphous polyethylene terephthalate resin sheet is preferably made of an amorphous polyester resin having a glass transition point of 35 to 100 ° C.
Such a polyester resin is excellent in moldability at the time of heating, and has an advantage that the deformation does not return after being deformed into a predetermined shape by molding.
[0014]
When the amorphous polyethylene terephthalate resin sheet has a glass transition point less than the lower limit, the thermal stability of the sheet deteriorates. Conversely, when the glass point transfer increases, the sheet formability tends to deteriorate. .
Therefore, as a glass transition point, it is 35-100 degreeC, Preferably it is 50-95 degreeC, More preferably, it is 65-95 degreeC.
[0015]
Examples of the non-crystalline polyethylene terephthalate resin in the non-crystalline polyethylene terephthalate resin sheet include dicarboxylic acid such as terephthalic acid or dimethyl terephthalic acid, and if necessary, isophthalic acid, naphthalene dicarboxylic acid, diphenylene dicarboxylic acid, etc. Using aliphatic dicarboxylic acids such as aromatic dicarboxylic acid, adipic acid, sebacic acid and oxalic acid, and their derivatives, ethylene glycol as diol, and if necessary, alkylene glycol such as butanediol, 1,4-cyclohexane It can be produced using aromatic diols such as dimethanol and derivatives thereof.
[0016]
More preferably, the non-crystalline polyethylene terephthalate resin is composed of two or more types of diol components, and optimally, the dicarboxylic acid content is terephthalic acid, and the diol component is ethylene glycol 50 to 50. 99 mol% and 1,4-cyclohexanedimethanol 1-50 mol% are good. In particular, those having 60 to 80 mol% of ethylene glycol and 20 to 40 mol% of 1,4-cyclohexanedimethanol are still better.
[0017]
As a specific non-crystalline polyethylene terephthalate resin, a commercial product manufactured by Eastman Kodak Company; KODAR PETG6763 (dicarboxylic acid component; terephthalic acid, diol component; ethylene glycol 70% by weight, 1,4-cyclohexanedimethanol 30% by weight) can be used.
[0018]
In the non-crystalline polyethylene terephthalate resin sheet, other additives such as a crystalline polyethylene terephthalate resin, a flame retardant, or inorganic fine particles may be blended within a range not impairing the performance.
[0019]
The amorphous polyethylene terephthalate resin sheet may be either non-stretched or stretched, but the non-stretched one is preferred for the transfer sheet of the present invention in terms of heating stability and moldability. Moreover, you may give surface treatments, such as a corona discharge process, as needed.
[0020]
A peelable layer 12 is laminated on the base sheet 11 made of the non-crystalline polyethylene terephthalate resin sheet as necessary. The peelable layer 12 effectively holds the transfer layer 20 by adhering to the base sheet 11 until transfer is performed using the transfer sheet, and the transfer layer 20 adheres to the transfer target during transfer. In order to realize smooth peeling between the peelable layer 12 and the transfer layer 20 by the adhesive force, it has adhesiveness that is not so strong.
[0021]
Generally, it is applied to the base sheet 11 using an ink composition prepared by appropriately adding a wax, silicone or the like as a release agent to a resin binder having good adhesion to an amorphous polyethylene terephthalate resin. Thereby, the peelable layer 12 is formed.
[0022]
Resin binders include nitrocellulose, cellulose acetate, cellulose butyrate, ethyl cellulose, polyamide resin, chlorinated rubber, cyclized rubber, polyamide resin, polyvinyl chloride resin, vinyl chloride / vinyl acetate copolymer resin, ethylene / vinyl acetate copolymer One type or two or more types are selected and used from resin, chlorinated polypropylene, acrylic resin, polyester resin, polyurethane resin, styrene male resin, or the like.
[0023]
The transfer layer 20 is generally formed by laminating a protective layer 22, a pattern layer 21, and an adhesive layer 23 in this order on the peelable layer 12 (on the lower surface of the peelable layer 12 in FIG. 1). Is.
[0024]
The protective layer 22 has the purpose of improving the physical or / and chemical durability of the pattern layer 21 described below transferred to the transfer target. Generally, it is often provided for the purpose of preventing the pattern from disappearing due to wear.
[0025]
Although the protective layer 22 can be composed of a thermoplastic resin, it is more preferably composed of a thermosetting resin in view of the above-mentioned purpose, and usually a polyurethane resin having both flexibility is often used.
[0026]
When higher durability is required, it is preferable to use an ionizing radiation curable resin composition. As the ionizing radiation curable resin composition, a prepolymer having a polymerizable unsaturated bond or an epoxy group in the molecule is used. What mixed the polymer, the oligomer, and / or the monomer suitably is used.
The ionizing radiation refers to an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking molecules, and usually an ultraviolet ray or an electron beam is used.
[0027]
Examples of prepolymers and oligomers in the ionizing radiation curable resin composition include unsaturated polyesters such as unsaturated dicarboxylic acid and polyhydric alcohol condensates, polyester methacrylate, polyether methacrylate, polyol methacrylate, melamine methacrylate, etc. Examples include methacrylates, polyester acrylates, epoxy acrylates, urethane acrylates, polyether acrylates, polyol acrylates, acrylates such as melamine acrylate, and cationic polymerization type epoxy compounds.
[0028]
Examples of the monomer in the ionizing radiation curable resin composition include styrene monomers such as styrene and α-methylstyrene, methyl acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, acrylic acid Acrylic esters such as butyl, methoxybutyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methoxyethyl methacrylate, ethoxymethyl methacrylate, phenyl methacrylate, lauryl methacrylate, etc. Esters, 2- (N, N-diethylamino) ethyl acrylate, 2- (N, N-dimethylamino) ethyl acrylate, 2- (N, N-dibenzylamino) methyl acrylate, acrylic acid -2- (N, N-diechi Unsaturated substituted amino alcohol esters such as amino) propyl, unsaturated carboxylic acid amides such as acrylamide and methacrylamide, ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol di Compounds such as acrylate, triethylene glycol diacrylate, polyfunctional compounds such as dipropylene glycol diacrylate, ethylene glycol diacrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate, and / or two or more thiol groups in the molecule Polythiol compounds having, for example, trimethylolpropane trithioglycolate, trimethylolpropane trithiopropylate, pentaerythritol Examples include tetrathioglycolate.
[0029]
Usually, as a monomer in an ionizing radiation curable resin composition, the above compounds are used alone or in combination of two or more as required. In order to give it, it is preferable that the prepolymer or oligomer is 5% by weight or more and the monomer and / or polythiol compound is 95% by weight or less.
[0030]
The ionizing radiation curable resin composition is applied by a known application method. However, when flexibility is required after application, the amount of monomer is reduced or the number of functional groups is 1 or 2. The acrylate monomer may be used. When wear resistance, heat resistance, and solvent resistance are required when an ionizing radiation curable resin composition is applied and cured, ionizing radiation such as using an acrylate monomer with three or more functional groups A curable resin composition can be designed. Here, 2-hydroxy acrylate, 2-hexyl acrylate, and phenoxyethyl acrylate are exemplified as those having one functional group. Examples of those having 2 functional groups include ethylene glycol diacrylate and 1,6-hexanediol diacrylate. Examples of the functional group having 3 or more include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.
[0031]
In order to adjust the physical properties such as flexibility and surface hardness when the ionizing radiation curable resin composition is applied and cured, a resin that is not cured by ionizing radiation irradiation should be added to the ionizing radiation curable resin composition. You can also. Specific examples of the resin include the following. Thermoplastic resins such as polyurethane resin, cellulose resin, polyvinyl butyral resin, polyester resin, acrylic resin, polyvinyl chloride resin, and polyvinyl acetate. Among these, addition of a polyurethane resin, a cellulose resin, a polyvinyl butyral resin, or the like is preferable from the viewpoint of improving flexibility.
[0032]
When hardening after application | coating of an ionizing radiation curable resin composition is performed by ultraviolet irradiation, a photoinitiator and a photoinitiator are added. As the photopolymerization initiator, in the case of a resin system having a radical polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether and the like are used alone or in combination. In the case of a resin system having a cationic polymerizable functional group, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metatheron compound, a benzoin sulfonic acid ester or the like is used alone or as a mixture as a photopolymerization initiator. . The addition amount of a photoinitiator is 0.1-10 weight part with respect to 100 weight part of ionizing radiation-curable resin compositions.
[0033]
The pattern layer 21 imparts aesthetics to the surface of the transfer target by transfer, and usually uses a pattern arbitrarily selected from various patterns.
The pattern of the pattern layer 21 may be a concrete pattern, an abstract pattern, or the like. Although it does not necessarily give an aesthetic appearance, it may be a character, a small solid pattern, a uniform uniform colored layer, a metal thin film layer, or the like. These may be combined as appropriate.
The pattern layer 21 is usually formed by printing in many cases, but may be formed by a method such as coating or vapor deposition.
[0034]
When the pattern layer 21 is formed by printing or coating, a colorant, solvent or diluent comprising a dye or / and a pigment is added to the same resin binder as that for forming the peelable layer 12, if necessary. It is carried out by a known printing method or coating method using an ink composition or paint composition prepared by blending extender pigments, surfactants, and other additives.
[0035]
The adhesive layer 23 is for adhering the pattern layer 21 and the protective layer 22 to the object to be transferred when the pattern layer 21 and the protective layer 22 are accompanied. The transfer mode, the material to be transferred, the object to be transferred This is a layer made of an adhesive resin that is selected in consideration of the use and the like.
Usually, a heat-sensitive adhesive that is activated by heating and generates an adhesive force is often used.
[0036]
Examples of the adhesive resin include polyvinyl acetate resin, polyvinyl alcohol, polyvinyl acetal (polyvinyl formal, polyvinyl butyral, etc.), cyanoacrylate, polyvinyl alkyl ether, polyvinyl chloride, polyamide, polymethyl methacrylate, nitrocellulose, and cellulose acetate. , Thermoplastic epoxy, polystyrene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, urea resin, melamine resin, phenol resin, resorcinol resin, furan resin, epoxy resin, unsaturated polyester resin, polyurethane resin, polyimide, polyamideimide , Polybenzimidazole, or polybenzothiazole can be used.
[0037]
Adhesive layer 23 is a rubber-based natural rubber, recycled rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, polysulfide rubber, silicone rubber, polyurethane rubber, stereo rubber (synthetic natural rubber), ethylene propylene. Rubber or block copolymer rubber (SBS, SIS, SEBS, etc.) may be used.
[0038]
In addition to the above layers, the transfer sheet 1 is usually a primer in the sense that it improves the adhesion between the substrate sheet 11, the peelable layer 12, the protective layer 22, the pattern layer 21, and the adhesive layer 23. A layer may be interposed.
[0039]
In the transfer sheet 1 of the present invention, since the base sheet is composed of an amorphous polyethylene terephthalate resin sheet, the mechanical properties such as tensile strength are much less than those of a normal polyethylene terephthalate resin sheet. It is inferior and has almost no disadvantage in handling, but rather has a feature of excellent thermoformability due to the material of the base sheet 11, and transfer utilizing this feature becomes possible. .
[0040]
The general transfer is performed by stacking the transfer sheet so that the transfer layer side of the transfer sheet is in contact with the transfer target, and applying pressure using a heating roll from the base sheet side of the transfer sheet, which is called hot stamping.
As a transfer method in the case where the object to be transferred has irregularities such as protrusions and recesses, typically, a pressure-air transfer that is performed by pressing a transfer sheet against the object to be transferred using vacuum or / and compressed air. In addition, there is simultaneous injection molding transfer using the heat and injection pressure of resin injected by setting a transfer sheet in a mold during injection molding.
[0041]
The true pressure air transfer will be described with reference to FIG. 2. For example, the transfer sheet 1 is sandwiched between the containers 30 a and 30 b divided vertically so that the transfer sheet 1 is on the lower side, and the air is fixed in an airtight manner. In FIG. 2, the upper and lower containers 30a and 30b are shown with a space therebetween for easy understanding.
[0042]
In the lower container 30 b, a transfer target 31 having an uneven shape is set on a fixing base 32. The fixing base 32 can be moved up and down. In this state, the transfer sheet is sufficiently softened by being heated by the heater 33. When the softening is performed, air pressure is introduced into the upper container 30a, and the lower container 30b is evacuated while raising the transfer target. By deforming the sheet 1 and bringing it into close contact with the uneven shape of the surface of the transfer target 31, the transfer layer of the transfer sheet 1 is adhered to the transfer target 31, and then the transfer target 31 is lowered, Transfer is performed by peeling the substrate sheet of the transfer sheet 1.
In some cases, either one of vacuum and compressed air is sufficient.
[0043]
In the above-described true-pressure air transfer, the transfer sheet 1 softened by heating is molded using the transfer target 31 as a mold, and therefore, the transfer sheet 1 is preferably one that has a property of being easily deformed by heating. The transfer sheet of the present invention using a non-crystalline polyethylene terephthalate resin sheet as a base sheet is required to be made of a material that can be thermoformed. Since it has a mechanical strength comparable to that of a terephthalate resin sheet, it is less likely to cause problems in handling.
[0044]
Next, the injection molding simultaneous transfer will be described with reference to FIG. 3. The molding dies 40 a and 40 b divided vertically are provided with a molding space 41 between the upper and lower dies, The transfer sheet 1 is set with the transfer layer 20 facing upward.
Next, the upper and lower molds are brought into close contact with each other, and the molten molding resin is injected from the upper mold sprue 42 toward the space 41 in the mold, so that the molten molding resin heats the transfer sheet 1. Since the pressure is simultaneously applied, the transfer sheet 1 is deformed and pressed along the inner surface of the lower mold 40b, and the space 41 on the upper side of the transfer sheet 1 is filled with the resin to be molded.
After molding, the mold is opened, the base material sheet 11 attached to the surface of the molded product is peeled off, and a resin molded product to which a pattern by transfer is attached is obtained.
[0045]
In the above-described simultaneous injection molding transfer, the transfer sheet 1 is softened by the molding resin that is melted and injected, and at the same time, it is pressed and molded along the molding surface by the pressure of the injected molten resin. The transfer sheet 1 preferably has a property of being easily deformed by heating, and needs to have heat resistance such that the strength does not decrease or break due to the high temperature of the molten resin. The transfer sheet of the present invention using a non-crystalline polyethylene terephthalate resin sheet as a base sheet has formability by heating, and also has mechanical strength and heat resistance comparable to that of a crystalline polyethylene terephthalate resin sheet. Transfer can be performed without any problem.
[0046]
In addition, in the above, as a transfer sheet, you may set what was shape | molded previously in a type | mold. In the molding performed in advance, it is not necessary to match the details of the shape of the mold for injection molding.
[0047]
【The invention's effect】
According to the invention of claim 1, since the non-crystalline polyethylene terephthalate resin sheet is used as the base sheet, it has mechanical strength and heat resistance comparable to a transfer sheet using the polyethylene terephthalate resin sheet. Moreover, since it can shape | mold by heating, the transfer sheet which can perform the transfer according to the intention with respect to the to-be-transferred object which has an unevenness | corrugation can be provided.
According to the invention of claim 2, in addition to the effect of the invention of claim 1, since the peelable layer is laminated on the surface of the base sheet, the adhesiveness of the transfer layer is moderate, and the peeling is smoothly performed at the time of transfer. Possible transfer sheets can be provided.
According to the invention of claim 3, in addition to the effect of the invention of claim 1 or 2, a transfer sheet that can improve the aesthetics of the object to be transferred having irregularities by transferring the pattern layer is provided. it can.
According to the invention of claim 4, in addition to the effect of the invention of claim 3, transfer can be performed with a protective layer on the pattern layer, and not only aesthetic appearance but also durability can be imparted to the transfer target. A transfer sheet can be provided.
According to the invention of claim 4, in addition to the effects of the invention of claim 4 or claim 5, since the adhesive layer is provided on the side of the transfer layer that contacts the transfer target, It is possible to provide a transfer sheet that does not require application of the agent again.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the structure of a transfer sheet of the present invention.
FIG. 2 is a diagram showing a transfer method using true pressure air forming.
FIG. 3 is a diagram showing a transfer method by simultaneous injection molding transfer.
[Explanation of symbols]
1 transfer sheet 10 base sheet (11; base sheet, 12 peelable layer)
20 Transfer layer (21; protective layer, 22; pattern layer, 23; adhesive layer)
30 True Pressure Air Molding Container 31 Transferred Object 40 Injection Mold

Claims (5)

It has a peelable substrate sheet having a peelable surface on its surface and a transfer layer laminated on the peelable surface so as to be peelable, and a substrate sheet for constituting the peelable substrate sheet is non- It is a crystalline polyethylene terephthalate resin sheet, the transfer layer is laminated with a pattern layer, and a protective layer for protecting the pattern layer that becomes the uppermost layer after transfer on the peelable substrate sheet side of the pattern layer, A transfer sheet, wherein the protective layer is made of a thermosetting resin or an ionizing radiation curable resin composition.   The transfer sheet according to claim 1, wherein the peelable substrate sheet is obtained by laminating a peelable layer on the surface of the amorphous polyethylene terephthalate resin sheet on the protective layer side.   The transfer sheet according to claim 1 or 2, wherein the transfer layer is formed by laminating an adhesive layer for adhering to the transfer target on the side of the pattern layer opposite to the peelable substrate sheet. .   The transfer sheet according to claim 1, wherein the protective layer is made of a thermosetting resin using a polyurethane-based resin.   The transfer sheet according to any one of claims 1 to 3, wherein the protective layer is formed by adding a thermoplastic resin to an ionizing radiation curable resin composition.

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