JP2548938B2 - Transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The transfer sheet of the present invention is transferred onto the surface of various molded articles and then irradiated with ultraviolet rays or electron beams to cure the transferred surface layer. It is used by making it possible to obtain a surface having excellent physical and chemical properties such as scratch resistance, chemical resistance and solvent resistance.

[Conventional technology]

Conventionally, when a product having a reinforced surface is produced by transfer, a protective layer is formed using a resin that is crosslinked by irradiation with ultraviolet rays or electron beams.

By the way, the protective layer is resistant to scratches when scratched or scratched by a hard object (scratch resistance)
It is necessary to add a lubricant in order to give However, in order to exert the effect of adding the lubricant, a considerable amount is required, the transparency of the protective layer is impaired, and the transparency of the lower layer of the protective layer becomes low after transfer.

[Problems to be solved by the invention]

The problems to be solved by the present invention are to maintain the effect of adding a lubricant and to improve the transparency of the protective layer in a transfer sheet in which a protective layer is formed using a resin that is cross-linked by irradiation with conventional ultraviolet rays or electron beams. That is, it was not possible to secure the same at the same time.

[Means for solving problems]

In the present invention, the protective layer is divided into two layers, a layer not containing a lubricant and a layer to which a lubricant is added to the same extent as in the conventional case, and the latter is the outermost layer after transfer, It is possible to solve the point, "The following two layers of the first and second layers are sequentially provided on the releasable surface of the releasable sheet,
A transfer sheet comprising a first and second uncured or partially cured resin layer, which serves as a post-transfer protection layer.

(A) A first uncured or partially cured resin layer made of a UV curable or electron beam curable resin which is solid at room temperature in the lubricant and uncured state and is thermoplastic, and (b) in an uncured state. A second uncured or partially cured resin layer which is a solid at room temperature and which is made of a thermoplastic resin that is ultraviolet curable or electron beam curable and does not contain a lubricant.

[Action]

According to this invention, since the protective layer is divided into two layers, a layer containing a lubricant and a layer not containing a lubricant, the required concentration of the lubricant can be maintained in the layer containing the lubricant, and the other layer is Since the material is not included, the amount of lubricant added can be reduced as a whole.

〔Example〕

The transfer sheet used in the present invention is basically composed of a releasable sheet and two non-effect resin layers.
Further, it may have a pattern layer, and may have an adhesive layer for the purpose of more reliable transfer.

Releasable Sheet As a general rule, the material of the releasable sheet may be one used in this type of transfer sheet, and the thickness thereof is usually preferably 5 to 200 μm, more preferably 12 to 1
It is 5 μm.

Specific examples include films of synthetic resin such as polyethylene terephthalate (so-called polyester), polypropylene, polyethylene, and polyamide, paper, and synthetic paper. These can be used by laminating if necessary.

The unevenness on the surface of the release sheet determines the unevenness on the surface of the protective layer when transferred. When the surface after the transfer is desired to be a mirror (mirror) surface, the surface of these release sheets must be a mirror surface. In addition, in the case of decorative applications, a matte surface is often required. In this case, a matte film is used as a release sheet, in which the matting agent is kneaded, and the glossy state is adjusted by sandblasting or chemical etching. Good to do.

The release sheet may be made of a material other than the above-mentioned materials, or may be provided with a release layer separately to make the surface releasable.

This releasable layer has a component that enables the protective layer to be peeled off from the base sheet of the transfer sheet during transfer, and specifically, an appropriate vehicle (an example of a vehicle is described below as a vehicle of an ordinary ink composition). Wax) alone or, if desired, additionally with a wax, for example paraffin wax,
It may be made by adding a releasing material such as montan wax or synthetic wax, or silicone.

First uncured resin layer This layer is the most surface layer after transfer, is a lubricant, and is solid at room temperature in the uncured state, and has thermoplasticity and solvent solubility. Of an ultraviolet curable resin or an electron beam curable resin that gives a coating film that is non-fluid (dry to the touch) even when touched by hand by coating and drying, and is non-adhesive. It is composed mainly of both components.

As the above-mentioned lubricant, waxes such as polyethylene wax, paraffin wax, synthetic wax, montan wax, carnauba wax, candelilla wax, microwax, etc., liquid materials such as silicone series, fluorine series etc. can be used.

By adding a lubricant, the resistance of the outermost surface after transfer to scratches and scratches can be increased.

As the above-mentioned ultraviolet curable resin or electron beam curable resin, there are the following two types of thermoplastic resins (1) and (2) having a radically polymerizable unsaturated group.

(1) Those having a radically polymerizable unsaturated group in a polymer having a glass transition temperature of 0 to 250 ° C. More specifically, a compound obtained by polymerizing or copolymerizing the following compounds (1) to (4) with a radically polymerizable unsaturated group introduced by the methods (a) to (d) described below can be used.

A monomer having a hydroxyl group; N-methylol (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2
-Hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate and the like.

Monomers having a carboxyl group: (meth) acrylic acid, (meth) acryloyloxyethyl monosuccinate and the like.

Monomer having epoxy group: glycidyl (meth) acrylate and the like.

Monomers having an aziridinyl group: 2-aziridinylethyl (meth) acrylate, allyl 2-aziridinylpropionate and the like.

Monomer having an amino group: (meth) acrylamide,
Diacetone (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the like.

Monomers having sulfone groups: 2- (meth) acrylamido-2-methylpropanesulfonic acid, etc.

Monomer having an isocyanate group: 1,4-toluene diisocyanate and 2-hydroxyethyl (meth) acrylate, such as an adduct of 1 mole to 1 mole of diisocyanate and a radical polymerizable monomer having active hydrogen.

Further, adjusting the glass transition point of the above copolymer,
In order to adjust the physical properties of the cured film, the above compound and the following monomers copolymerizable with this compound can be copolymerized. Examples of such a copolymerizable monomer include, for example, methyl (meth) acrylate,
Ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate,
Examples thereof include isoamyl (meth) acrylate, cyclohexyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

Next, the polymer obtained as described above is reacted by the methods (a) to (d) described below to introduce a radically polymerizable unsaturated group, whereby an ultraviolet ray or electron beam curable resin is obtained. .

In the case of (a) a polymer or copolymer of a monomer having a hydroxyl group, a monomer having a carboxyl group such as (meth) acrylic acid is subjected to a condensation reaction.

(B) In the case of a polymer or copolymer of a monomer having a carboxyl group or a sulfone group, the above-mentioned monomer having a hydroxyl group is subjected to a condensation reaction.

(C) In the case of a polymer or copolymer of a monomer having an epoxy group, an isocyanate group or an aziridinyl group, the above-mentioned monomer having a hydroxyl group or a monomer having a carboxyl group is added.

(D) In the case of a polymer or copolymer of a monomer having a hydroxyl group or a carboxyl group, a monomer having an epoxy group, a monomer having an aziridinyl group, or a diisocyanate compound and a hydroxyl group-containing acrylate monomer One to one mole of the adduct of the product is subjected to an addition reaction.

In order to carry out the above reaction, it is desirable to add a trace amount of a polymerization inhibitor such as hydroquinone and to carry out the reaction while sending dry air.

(2) A compound having a radical-polymerizable unsaturated group and a melting point of room temperature (20 ° C) to 250 ° C. Specific examples thereof include stearyl acrylate, stearyl (meth) acrylate, triacryl isocyanurate, cyclohexanediol diacrylate, cyclohexanediol di (meth) acrylate, spiroglycol diacrylate, and spiroglycol (meth) acrylate. Further, in the present invention, the above (1) and (2) may be mixed and used.

Lubricants and solid at room temperature in the uncured state,
In addition, a coating film that has thermoplasticity and solvent solubility, is non-fluid (dry to the touch) even when touched by hand by coating and drying, and is non-adhesive Both components of the ultraviolet curable resin or the electron beam curable resin to be given are the ultraviolet curable resin or the electron beam curable resin.
The lubricant is used in an amount of 0.1 to 30 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight.
If it is less than 0.1 parts by weight, the effect of addition is poor, and if it exceeds 30 parts by weight, the effect is not improved, and the hardness of the film,
Robustness is lost.

When providing the first uncured resin, a radical-polymerizable unsaturated monomer may be further added. This radically polymerizable unsaturated monomer improves the crosslink density and the heat resistance upon irradiation with ionizing radiation, and in addition to the above-mentioned monomers, ethylene glycol di (meth) acrylate and polyethylene. Glycol di (meth) acrylate,
Hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate , Ethylene glycol diglycidyl ether di (meth) acrylate, polyethylene glycol diglycidyl ether di (meth) acrylate, propylene glycol diglycidyl ether di (meth) acrylate, polypropylene glycol diglycidyl ether di (meth) acrylate, sorbitol tetraglycidyl ether tetra ( (Meth) acrylate or the like can be used, and the above-mentioned ultraviolet curable resin or electron beam curable resin can be used. 0.1 to 10 per 100 parts by weight of resin
It is preferable to use 0 parts by weight. Further, although the above can be sufficiently cured by an electron beam, in the case of curing by ultraviolet irradiation, benzoin such as benzoquinone, benzoin, benzoin methyl ether, etc. as a sensitizer. It is also possible to use ethers, halogenated acetophenones, biacetyls and the like that generate radicals by irradiation with ultraviolet rays.

To apply the above components to the releasable surface of the releasable sheet, known methods such as roll coating, curtain flow coating, wire bar coating, gravure coating, air knife coating, reverse coating Method, kiss coating method, blade coating method, smooth coating method, etc., and the coating amount is 1 μm to 10 μm when dried.
m.

Second uncured resin layer This layer is solid at room temperature in an uncured state, and has thermoplasticity and solvent solubility, but when it is apparently or touched by hand by coating and drying. Is mainly composed of an ultraviolet curable resin or an electron beam curable resin that gives a coating film that is non-fluid (dry to the touch) and is non-tacky, and has the above-mentioned first uncured resin. The same material as that of the above-mentioned first uncured resin layer can be used except that the lubricant is removed from the layer, and the layer can be provided by the same method.

The thickness of the second uncured resin layer is 1 μm to 50 μm, preferably 1 μm to 5 μm.

Other Layers In addition to the above-mentioned first and second uncured resin layers, the following various layers provided in a normal transfer sheet can be provided.

Adhesive layer Even if the above uncured resin layer is applied to the transfer target and transferred, a temporary adhesive force can be obtained. However, when it is necessary to further improve the adhesive force, another adhesive layer is used. Should be provided as

As the adhesive for the adhesive layer, known adhesives can be used, for example, rubber-based resins such as polyisoprene rubber, polyisobutyl rubber, styrene-butadiene rubber, and butadiene acrylonitrile rubber, (meth) acrylic acid ester-based resins, polyvinyl. It is possible to use any adhesive such as ether resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, polystyrene resin, polyester resin, polyamide resin, polychlorinated olefin resin, polyvinyl butyral resin, etc. it can.

These resins are diluted, if necessary, to have a viscosity suitable for coating, and then coated by a known coating method such as reverse roll coating, roll coating, gravure coating, kiss coating, blade coating, and smooth coating.

In the transfer sheet of the present invention, the method of providing the other layers is almost the same, except that when the layers are provided in a pattern, a printing technique is used.

Pattern layer Since the pattern layer is for imparting a pattern to the transfer target by transfer, it is always necessary in the pattern transfer sheet intended to transfer the pattern. An example of a transfer sheet that does not require a pattern layer is a protective layer transfer sheet that transfers substantially only a protective layer, and the use of this is a substitute for painting. A specific protective layer transfer sheet should be prepared by considering the adhesion or peelability with the release sheet, the adhesiveness of the protective layer with the transfer target, the necessity of the adhesive layer, etc. according to the application. Good.

The pattern layer is usually provided directly on the protective layer or indirectly via another layer, and the type of ink may be determined in consideration of the application and the structure of the transfer sheet. An ordinary ink is obtained by kneading a vehicle with a pigment or dye coloring agent, a plasticizer, a stabilizer, other additives, a solvent or a diluent, or the like.

Among the components of the ink, as binders related to adhesiveness, homopolymers of acrylic or methacrylic monomers such as poly (methyl methacrylate), poly (ethyl methacrylate), poly (ethyl acrylate) and poly (butyl acrylate), or these monomers are used. Copolymers containing, polystyrene, styrene resins such as poly α-methylstyrene and styrene copolymer resins, ethyl cellulose, ethyl hydroxyethyl cellulose, cellulose acetate propionate, cellulose derivatives such as cellulose acetate, rosin, rosin-modified maleic acid resin, Rosin-modified phenol resin, rosin ester resin such as polymerized rosin, polyvinyl acetate resin, vinyl chloride resin, coumarone resin, vinyltoluene resin, butyral resin, polyurethane resin, polyester resin, Click, gum arabic, Akaroido uses one or two or more of such mastic.

The ink provided with the pattern layer may be an ionizing radiation curable ink.

The structure of the transfer sheet is basically as described above. However, if necessary, the following layers can be provided.

Solvent volatilization-type resin layer A solvent volatilization-type resin such as a thermoplastic resin is provided between the curable layer and a layer that directly contacts the second uncured resin layer, for example, a pattern layer. Layers may be provided,
By doing so, when providing the pattern layer, it is sufficient to consider only the adhesion to the uncured resin layer that is interposed, and there is an advantage that the selection range of the binder of the ink when forming the pattern layer is expanded.

Metal thin film layer A metal thin film layer may be provided on the surface of the transferred material in order to give a metallic appearance. The material for forming the metal thin film layer is aluminum, chromium, tin, silver, copper, gold, etc., and the thickness is usually about 400 to 600Å. The metal thin film layer can be patterned if necessary.A metal thin film is provided after forming a water-soluble pattern, and water is then applied, or a metal thin film is first provided and then a resist pattern is provided. After that, there is a method of applying acid or alkali.

Method of Use The transfer sheet of the present invention is transferred onto a surface of a transferred material by transferring it by an appropriate method and then irradiating it with ultraviolet rays or electron beams to completely cure the transferred uncured resin layer. A fully cured film can be produced. At this time, there is a case where the release sheet is peeled off before irradiation and a case where it is peeled off after irradiation. If the protective layer of the transfer sheet is required to have some heat resistance, it is necessary to partially cure (so-called “half-cure”, not necessarily half-cure) a range that does not lead to complete curing. It can also be transcribed.

As a transfer method, for example, a pattern layer (in some cases, another layer such as an adhesive layer further provided on the pattern layer) may be thermocompression-bonded to the transfer target by heating to transfer the pattern together with the uncured resin layer. Examples thereof include a thermal transfer method performed, and a solvent activated transfer method performed by interposing an activating liquid composed of a solvent or a solvent solution of a resin between the transfer sheet and the transfer target.

Alternatively, as an interesting method, it is possible to apply and transfer to a molding method such as press molding, vacuum molding, pressure molding, vacuum pressure molding, simultaneous injection molding, extrusion molding, calendar molding, etc. The transfer can be performed at the same time as the molding.

In addition, after transfer, to make the transferred material more predetermined shape,
You may perform press molding, vacuum molding, pressure molding, vacuum pressure molding, etc.

Transfer Target Various objects can be used as the transfer target (transfer target) using the transfer sheet of the present invention. As an object to be transferred, other than an object which has already been molded into a predetermined shape or a material which is previously molded into a simple shape such as a flat plate shape, the transfer can be performed in the same manner as when the object to be transferred is manufactured. Including the following, for example:

AAS resin, ABS resin, ACS resin, amino resin, cellulose resin such as cellulose acetate / cellulose cellulose butyrate / ethyl cellulose, allyl resin, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene-
Vinyl chloride copolymer, ionomer resin, MBS resin, methacryl-styrene copolymer, nitrile resin, phenol resin, polyamide resin, polyarylate resin, polycarbonate resin, polybutadiene resin, polybutylene terephthalate resin, polyethylene resin, polyethylene terephthalate resin, Plastic molded products made of plastics such as polymethylmethacrylate resin, polypropylene resin, polyphenylene oxide resin, polystyrene resin, AS resin, polyurethane resin, polyvinyl chloride resin, acrylic modified polyvinyl chloride resin and unsaturated polyester resin.

Extruded products of metals such as iron, aluminum, copper, and stainless steel.

If necessary, the transfer surface of these transfer materials may be subjected to a pretreatment suitable for the material of the transfer material surface. For example, pretreatment for improving adhesion such as primer treatment or corona treatment, coating. Others include adjustment of the base color, sealing treatment, and alkali leaching prevention treatment on an alkaline substrate such as cement.

Ionizing Radiation Irradiation After the transfer sheet is used to transfer the image to a transfer target, the transfer sheet is irradiated with ionizing radiation to cure the transferred first and second uncured resin layers. The ionizing radiation is typically ultraviolet rays and electron beams.

As the electron beam, 50-1000 KeV, preferably 100-, emitted from various electron beam accelerators such as Cockloft-Walton type, Van de Graaff type, resonance transformer type, insulating core transformer type, linear type, dynamitron type high frequency type, etc. An electron beam having an energy in the range of 300 KeV can be used, and as the ultraviolet ray, one that is emitted from an ultraviolet ray source using a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, carbon arc, xenon arc, and a metal halide lamp is used. be able to.

〔The invention's effect〕

According to this invention, the uncured resin layer that becomes the protective layer after transfer is divided into two layers, and the lubricant is contained only in the layer that becomes the uppermost layer after transfer, so the content of the lubricant as a whole is small, Moreover, since a sufficient amount of lubricant can be added to the uppermost layer, addition and curing of the lubricant is not impaired.

[Specific examples]

Example 1 A polyester film (Lumirror T-60, manufactured by Toray Industries, Inc.) was used as a release film, and a melamine resin varnish (manufactured by Dainichiseika Co., Ltd.) was gravure coated on one side thereof to give a thickness of 0.5 μm. A releasable layer was formed.

Then, on the releasable layer, to 100 parts by weight of an ultraviolet curable resin (Mitsubishi Yuka Co., Ltd., trade name Upia LZ-075),
1 part by weight of polyethylene wax was added and the paint diluted with methyl ethyl ketone to a solid content of 35% was coated by gravure coating to obtain a coating thickness of 2.
A 5 μm first uncured resin layer was provided.

On the first uncured resin layer, the same paint used to provide the first uncured resin layer, except that polyethylene wax was not added and the solid content was 40%, A second uncured resin layer having a coating thickness of 3.5 μm was provided by performing gravure coating.

On the first and second uncured resin layers, a pattern is printed by using a gravure ink containing a mixture of an acrylic resin and a nitrocellulose resin as a vehicle, and the acrylic is further printed on the pattern. A resin solution of a mixed solvent of the resin, methyl ethyl ketone / toluene = 2/1 (weight ratio), was applied to the entire surface to form an adhesive layer.

The obtained transfer sheet was transferred onto a surface of an acrylic resin plate using a heat roll (surface temperature: 200 ° C.) so that the adhesive layer side of the transfer sheet was in contact, and after transfer, the polyester film was peeled off.

The uncured resin layer was cured by irradiating the transferred acrylic resin plate for 10 seconds under a high pressure mercury lamp of ozone type (80 W / cm) so that the transferred surface was slightly irradiated.

The resulting acrylic plate with a patterned and hardened surface is
It was not scratched by rubbing with Steel Wool # 0000.

For comparison, in the same manner as above, except that the first uncured resin layer was provided to have a thickness of 6.0 μm, and the second uncured resin layer was not provided, a comparative transfer sheet was produced and the same procedure was performed. Even when compared with the one obtained by transfer, the protective layer was transparent, the cloudiness was not felt, the pattern was clearly visible, and the design was good.

Example 2 After the first and second uncured resin layers were formed in the same manner as in Example 1, Alnium was vapor-deposited to a thickness of 600Å on the entire surface, and after vapor deposition, acrylic resin methyl ethyl ketone / toluene = 2/1 ( A resin solution with a mixed solvent (weight ratio) was applied to the entire surface to form an adhesive layer, and thus a transfer sheet was manufactured.

The obtained transfer sheet was used for transfer in the same manner as in Example 1 and irradiated with ultraviolet rays. As a result, the surface of the transferred plate was excellent in transparency of the protective layer, and the brightness of the aluminum vapor deposition layer was excellent. Excellent and surface steel wool # 0000
It was not scratched by rubbing.

Claims (3)

(57) [Claims] 1. A transfer comprising a first and a second layer described below sequentially provided on a release surface of a release sheet, the transfer comprising a first and a second uncured or partially cured resin layer. A transfer sheet having a layer to be a post-protection layer. (A) A first uncured or partially cured resin layer made of a UV curable or electron beam curable resin which is solid at room temperature in the lubricant and uncured state and is thermoplastic, and (b) in an uncured state. A second uncured or partially cured resin layer which is solid at room temperature and which is composed of a thermoplastic resin that is ultraviolet curable or electron beam curable and does not contain a lubricant. 2. The transfer sheet according to claim 1, further comprising a pattern layer on the second uncured or partially cured resin layer. 3. The transfer sheet according to claim 1, further comprising an adhesive layer as an uppermost layer.