JPH08156390A - Transfer of patterns to surface of glass - Google Patents

Abstract

PURPOSE: To form patterns of high quality on a glass product by applying an adhesive layer composed of an ionizing radiation curable resin to the surface of the glass product to irradiating the coated adhesive layer with ionizing radiation to crosslink and cure the same and bringing a transfer sheet into contact with the adhesive layer. CONSTITUTION: When patterns are transferred to the surface of a glass product 1, at first, an adhesive layer 2 composed of an ionizing radiation curable resin is applied to the surface of the glass product 1 and, next, the surface of the adhesive layer 2 is irradiated with ionizing radiation 5 to crosslink and cure the adhesive layer 2 so that crosslinking density becomes high from the surface of the adhesive layer 2 to the interior thereof. That is the adhesive layer 2 is not perfectly crosslinked and cured in the vicinity of its surface but perfectly crosslinked and cured in the vicinity of the interface with the glass product 1. Continuously, a transfer sheet 3 is superposed on the adhesive layer 2 so that the transfer layer 32 thereof comes into contact with the surface of the adhesive layer 2. After the transfer layer 32 is bonded to the adhesive layer 2, only a support sheet 31 is peeled and removed to transfer the transfer layer 32 to the adhesive layer 2. By this constitution, patterns of high quality are formed on the glass product 1 having a shape of every kind.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for imparting a pattern to a glass product surface such as a plate glass and a glass bottle by a transfer method.

[0002]

2. Description of the Related Art Conventionally, a method of directly printing on a glass surface has been used as a method of imparting a pattern on the surface of a glass product. However, the direct printing method cannot apply a printing method such as gravure printing, which is capable of expressing fine gradations, such as gravure printing, to a hard and thick material such as a glass surface. In particular, it is even more difficult when the glass surface has low smoothness and swells.
Therefore, the silk screen printing method has been mainly used as a direct printing method on the glass surface, but it is difficult to obtain a fine pattern and gradation expression by this method. It was also not applicable to curved bodies such as bottles.

Therefore, in order to improve these drawbacks, a method has been developed in which a transfer sheet is prepared by printing a transfer layer including a pattern layer on a support sheet, and the transfer layer is transferred to the glass surface. . According to this method, the object to be printed is a support sheet made of a thin film synthetic resin sheet having good printability, and only the pattern already formed is transferred (moved) to the glass surface. Therefore, it is a thick rigid body,
It has become possible to impart a fine pattern with rich gradation to the surface of a glass product, which is a curved body or has a ridge on the surface.

As one of them, Japanese Patent Publication No. 53-42
No. 043, etc., a transfer layer is composed of a glass powder, an inorganic pigment powder, and a resin binder, and this is transferred onto the glass surface by using a heat-sensitive (heat-melting) type adhesive layer. There is disclosed a transfer method in which a pattern layer in which an inorganic pigment is bound to a glass material is baked on the glass surface by baking the resin to burn and sublimate a resin (organic substance). In this method, it is possible to apply gravure printing or the like to give a pattern that is sufficiently precise and rich in gradation, and since the pattern layer is vitreous, it contains a pattern layer. The transfer layer has good surface properties such as surface hardness, chemical resistance, and heat resistance. However, on the other hand, a process called post-transfer baking is required, which takes time and requires equipment, heating and heating costs, which is a problem in terms of production efficiency and cost. Therefore, the following non-firing method for transferring onto glass has been developed. In these methods, it is not possible to obtain sufficient adhesion to the glass surface with the heat-sensitive adhesive layer of the thin film on the transfer sheet,
In both cases, a thick film of an adhesive layer is applied on the glass surface side, and a transfer layer is transferred onto the adhesive layer. That is,

Japanese Utility Model Publication No. 5-20523 discloses a method in which an isocyanate-curable polyurethane adhesive layer is formed on the glass surface by coating, the coating is cured, and the transfer layer is thermally transferred onto the surface. This method does not require such high temperature firing. However, in order to completely cure the polyurethane resin, a curing step for 3 to 5 days is still required at a temperature of about 40 to 60 ° C. Therefore, there is a problem in that equipment and utilities are required for that purpose, and the process time becomes long.

Therefore, in order to improve this drawback, the methods described in Japanese Patent Publication No. 63-51112 and Japanese Patent Publication No. 63-21638 have been developed. Here, an uncured liquid of an ultraviolet curable resin is applied to the glass surface as an adhesive layer,
A transfer sheet is laid on top of it so that the transfer layer side is in contact with the adhesive layer, and in that state, ultraviolet rays are radiated from the transfer sheet side to crosslink and cure the adhesive to bond and integrate it with the transfer layer. A method of peeling and removing only the support sheet is disclosed. In this method, an ultraviolet lamp is prepared, and the adhesive layer can be cured only by an irradiation step of several seconds at room temperature,
No heating process and equipment like those are required, and the process time is short. However, when actually carried out, ultraviolet rays are absorbed in the pattern of the transfer sheet, which causes a problem. That is, when the pattern is entirely dark, the curing of the adhesive layer is insufficient over the entire surface, and in extreme cases, part or all of the pattern is taken on the support sheet side at the time of peeling the support sheet, resulting in poor transfer or It becomes impossible. Further, when the pattern has a partial or gradation of light and shade, the adhesive directly under the light portion of the pattern has a high degree of curing by ultraviolet rays, a large curing shrinkage, and no fluidity. On the other hand, since the adhesive just under the dark portion of the pattern has a relatively small degree of curing by ultraviolet rays, its curing shrinkage is small and its fluidity is also to some extent. Therefore, due to the difference in shrinkage stress and fluidity of the adhesive layer between the dark portion and the light portion, the adhesive layer immediately below the dark portion is pulled and moved by the adhesive layer immediately below the light portion, and It will be an uneven surface that is relatively recessed from just below the light part. Naturally, the surface properties of the recess are poor. Therefore, in order to further improve the above problem, JP-A-53-53
The method described in Japanese Patent Publication No. 29811 has been tried. In the same way as here, but let the ultraviolet rays through the glass layer,
That is, a method of irradiating from the side opposite to the transfer sheet is disclosed. However, when this method was actually used, the result was still insufficient. That is, since glass generally absorbs ultraviolet rays well, ultraviolet rays that have passed through the glass are attenuated and the curing of the adhesive becomes insufficient, and the adhesive force between the glass and the adhesive or the adhesive and the pattern becomes insufficient. However, even if transfer is possible, the surface properties of the transfer pattern layer will be low.
Therefore, it was found that this method is not practical except for special glass such as quartz glass having a low ultraviolet absorption rate.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art and uses a gravure printing method or the like on a surface of a glass product regardless of the shape of a flat plate or a curved surface to form a fine or shaded layer. An object of the present invention is to provide a method capable of forming a high-quality pattern rich in tone. It is another object of the present invention to provide a highly efficient pattern forming method for a glass product which does not require heating in the pattern forming step and can be completed in a short time of several seconds. Further, the present invention is wear resistance, chemical resistance,
The object is to form a pattern layer having good surface properties such as heat resistance and adhesion to the glass surface, regardless of the size of the shade area of the pattern.

In the present invention, an adhesive agent of an ionizing radiation curable resin such as ultraviolet rays, which has a good adhesive force and is cured at room temperature (room temperature) in a short time, is applied, and a pattern is formed on the glass surface. A transfer method is adopted, and an object thereof is to solve the defect of the transfer sheet or the curing failure of the adhesive due to the glass. UV irradiation to the UV-curable resin adhesive layer on the glass surface, transfer, and curing sequence,
To simply list the combinations of the irradiation directions and the irradiation directions, in addition to the above-mentioned conventional technique, “first, an adhesive layer is applied to the glass surface, and then the adhesive is UV-cured from the surface side (without passing through the glass). Then, after that, a pattern is transferred onto the adhesive layer. It is also possible that there is a combination. However, this method has never been noticed or tried for some reason. It is inferred from this that "the adhesives of UV curable resins that are usually used have the property that the curing reaction is inhibited by oxygen or moisture in the atmosphere (see Japanese Patent Laid-Open No. 47-30730). Therefore, if ultraviolet rays are irradiated in the air without covering the adhesive surface with a transfer sheet, curing will be insufficient due to the action of oxygen or moisture (moisture) in the air atmosphere, and in extreme cases, the adhesive layer will be liquid. Therefore, neither adhesion to glass nor pattern transfer is possible. Further, even if transfer and adhesion can be performed, the physical properties of the pattern layer are extremely low because the adhesive layer is insufficiently cured. On the other hand, it has been known that the ultraviolet curable resin is completely cured by increasing the irradiation amount of ultraviolet rays or by irradiating it in an inert atmosphere such as nitrogen. Once cured, the chemical activity of the adhesive is lost,
It no longer adheres to the pattern layer. Therefore, it is not practical in any case. It is thought that it was because it was thought.

The present inventor has considered this point and said, "If the inhibition of curing of the ultraviolet-curable resin adhesive layer is due to oxygen or moisture in the atmosphere, the oxygen or water molecules are It should gradually diffuse and penetrate from the surface. Therefore, the degree of inhibition of hardening of the adhesive layer is greatest in the vicinity of the surface, and should have a gradient in the thickness direction such that it gradually decreases toward the inside of the layer. Therefore, if the adhesive layer left in the air atmosphere for an appropriate time is cured by UV,
In the vicinity of the surface, it is incompletely hardened so that it does not flow and has chemical and physical activity, so that it can be transferred and adheres well to the pattern layer. Further, since oxygen or moisture has not reached the interface between the glass and the adhesive layer, the interface is completely cured and the adhesive force with the glass is improved. 』I predicted that. Therefore, we dared to challenge the conventional prejudice, "First, apply a UV-curable adhesive layer on the glass surface, then cure the adhesive from the surface side with UV (without passing through the glass), and after that The pattern is transferred onto the agent layer. The present invention has been accomplished by obtaining a method for transferring a pattern onto a glass surface, in which the above-mentioned drawbacks of the prior art are eliminated.

[0010]

In order to solve the above problems, in the method of the present invention, "(Claim 1) a method for transferring a pattern onto a glass surface characterized by including the following steps; Glass product A step of coating an adhesive layer of an ionizing radiation curable resin on the surface of the adhesive layer, and then irradiating the surface of the adhesive layer with ionizing radiation to increase the crosslinking density of the adhesive layer from the surface toward the inside. Cross-link and harden in the same manner, and the surface of the adhesive layer is non-fluid, but is not completely cross-linked and hardened yet, and the vicinity of the interface between the adhesive layer and the glass surface is completely Step of bringing into a state of being cross-linked and cured, then preparing a transfer sheet having a transfer layer containing at least a pattern layer on a support sheet, and contacting the transfer layer side of the transfer sheet with the adhesive layer surface side In the same manner, and then the transfer layer A step of adhering to the adhesive layer, after which only the support sheet is peeled and removed, and the transfer layer is transferred to the adhesive layer. (Claim 2) A method for transferring a pattern onto a glass surface, which comprises performing a step of applying an overcoat coating film on the surface of the transfer layer after the step of claim 1. (Claim 3) A step of irradiating ionizing radiation to completely crosslink and cure the surface of the adhesive layer after the final step of claim 1 or 2, Pattern transfer method. ] Is the summary. .

The glass product 1 is a flat plate (plate glass) used for windows, partitions or the like, or a curved plate, a container having a three-dimensional shape such as a bottle or a plate. The material of the glass includes soda glass, potassium glass, lead glass, borosilicate glass, quartz glass and the like. The glass surface may be untreated, but in order to prevent repellency of the adhesive and to improve the adhesion between the glass and the adhesive, it is preferable to coat the surface of the glass product before coating the adhesive. It is advisable to degrease with an alkali, a surfactant, an organic solvent or the like, or to apply an easily adhering primer such as a silane coupling agent in addition thereto.

The adhesive forming the adhesive layer 2 is a material containing an ionizing radiation curable resin as at least a main component. As the ionizing radiation-curable resin, a monomer having two or more radically polymerizable unsaturated groups such as (meth) acryloyl group and (meth) acryloyloxy group or cationically polymerizable functional groups such as epoxy group in the molecule. It is composed of a body, a prepolymer or a polymer (hereinafter collectively referred to as a compound). These monomers, prepolymers or polymers may be used alone or in combination of two or more. In addition, in this specification, (meth) acrylate is used to mean acrylate or methacrylate. Further, in the present specification, when simply referred to as an adhesive, it means an adhesive of an ionizing radiation curable resin.

Examples of the prepolymer having a radical-polymerizable unsaturated group include polyester (meth) acrylate, urethane (meth) acrylate and epoxy (meth).
Acrylate, melamine (meth) acrylate, triazine (meth) acrylate, etc. can be used. As the molecular weight, those having a molecular weight of about 100 to 10,000 are usually used. Both acrylates and methacrylates can be used, but acrylates are more advantageous in terms of crosslinking and curing speed with ionizing radiation, and therefore acrylates are more advantageous for the purpose of curing efficiently at high speed in a short time. As the polymer having a radically polymerizable unsaturated group, a polymer having a degree of polymerization of the above prepolymer of about 10,000 or more is used.

Examples of the prepolymer having a cationically polymerizable functional group include epoxy resins such as bisphenol type epoxy resin, novolac type epoxy resin, alicyclic type epoxy resin, and aliphatic type epoxy resin, aliphatic type vinyl ether, and aromatic resin. There are vinyl ether resins such as group vinyl ethers, urethane vinyl ethers and ester vinyl ethers, and prepolymers such as cyclic ether compounds and spiro compounds.

Examples of the monomer having a radical-polymerizable unsaturated group include monofunctional monomers of (meth) acrylate compounds such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth). ) Acrylate, methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, butoxyethyl (meth) acrylate, 2 ethylhexyl (meth) acrylate,
N, N-dimethylaminomethyl (meth) acrylate,
N, N-dimethylaminoethyl (meth) acrylate,
N, N-diethylaminoethyl (meth) acrylate,
N, N-diethylaminopropyl (meth) acrylate, N, N-dibenzylaminoethyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate, ethylcarbitol (meth) acrylate, phenoxyethyl (meth) acrylate ,
Phenoxy polyethylene glycol (meth) acrylate, tetrahydroxyfurfuryl (meth) acrylate, methoxytripropylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2- (meth) acryloyloxypropyl There are hydrogen phthalate and the like.

Examples of the polyfunctional monomer having a radical-polymerizable unsaturated group include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth). Acrylate, dipropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexyldiol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tetraethylene glycol di (meth) ) Acrylate, triprorylene glycol di (meth) acrylate, bisphenol A-di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate ) Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin polyethylene oxide tri (meth) acrylate, tris (meth) Examples include acryloyloxyethyl phosphate.

As an example of the monomer having a cationically polymerizable functional group, the above-mentioned prepolymer monomer having a cationically polymerizable functional group can be used.

Among these compounds, surface properties after transfer,
From the viewpoint of elongation and flexibility, radical polymerization type urethane (meth) acrylate is preferable. A cationic polymerization type epoxy is preferable from the viewpoints of adhesiveness to the transfer layer and ease of forming a gradient of crosslink density.

A photopolymerization initiator is added to the ionizing radiation-curable resin adhesive when it is cured with ultraviolet rays or visible rays. In the case of a resin system having a radically polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether,
Michler's benzoyl benzoate, Michler's ketone, diphenyl sulfide, dibenzyl disulfide, diethyl oxide, triphenylbiimidazole, isopropyl-N, N-dimethylaminobenzoate, etc. can be used alone or in combination. Further, in the case of a resin system having a cationically polymerizable functional group, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metallocene compound, a benzoin sulfonate ester, a fryloxysulfoxonium salt, a diallyl iodosyl salt, etc. Can be used alone or as a mixture. The addition amount of these photopolymerization initiators is about 0.1 to 10 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin.

If necessary, the ionizing radiation-curable resin contains inorganic fine powder of calcium carbonate, alumina, silica, barium sulfate, acrylic beads, urethane beads,
Fillers made of resin beads such as polycarbonate beads, volatile diluent solvents such as organic solvents, and colorants such as dyes and pigments may be added. Also, if necessary, a thermoplastic resin which is solid at room temperature is added to improve the drying property of the ionizing radiation curable resin adhesive layer on the surface in the uncured state.
In addition, the adhesion with the transfer layer can be improved. However, if too much is added, the cross-linking density of the adhesive layer will decrease and the adhesive strength will decrease, or the surface properties such as abrasion resistance and heat resistance of the transferred transfer layer will decrease. Therefore, when it is added, the content is about 10% by weight or less. Examples of thermoplastic resins that are solid at room temperature include thermoplastic acrylic resins, cellulosic resins, vinyl chloride / vinyl acetate copolymers, polystyrene and the like.

The ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing and cross-linking molecules, and includes visible light, ultraviolet light (near ultraviolet light, vacuum ultraviolet light, etc.), X-ray, electron beam and the like. is there. Usually, ultraviolet rays or electron beams are used. As the ultraviolet ray source, a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, and a metal halide lamp can be used.
As the wavelength of ultraviolet rays, a wavelength range of 1900 to 3800Å is usually mainly used. As the electron beam source, Cockloft-Walton type, Van de Graaff type, resonant transformer type, insulating core transformer type, or linear type, dynamitron type,
100 to 100 using various electron beam accelerators such as high frequency type
Those which irradiate with electrons having an energy of 0 KeV, preferably 100 to 300 KeV can be used. Upon irradiation with ionizing radiation, the ionizing radiation curable resin causes a cross-linking polymerization reaction and changes into a three-dimensional polymer structure. Such a change is called hardening.

The transfer sheet 3 comprises a support sheet 31 and a transfer layer 32 which is releasably temporarily adhered onto the support sheet 31.
As the material of the support sheet, a resin sheet such as polyethylene terephthalate, polybutylene terephthalate, ethylene terephthalate / isophthalate copolymer, polyethylene naphthalate, polyester resin such as polyarylate, polyolefin resin such as polyethylene, polypropylene, polymethylpentene, etc. Is. If necessary, a release layer may be further formed on the resin film by using silicon resin, melamine resin, polyolefin resin or the like. In addition, coated paper coated with a release resin such as silicone resin or polyolefin resin is used, and a thickness of about 10 μm to 200 μ can be used. Furthermore, when it is desired to impart a desired matte or uneven pattern to the surface of the transfer layer after the transfer, even if a desired uneven pattern of reverse unevenness is formed on the surface of the support sheet or the release layer. Good. Examples of such uneven patterns include matte, hairline, wood grain conduit, linear grooves, diffraction grating, hologram and the like. The release layer in the present invention means a layer which is released at the interface with the transfer layer at the time of transfer and is adhered to the support sheet side and is removed together with the support sheet.

A pattern layer is essential as the transfer layer, and if necessary, a release layer may be provided on the support sheet side, or a transfer sheet side adhesive layer may be provided on the side opposite to the support sheet. Either one of the release layer and the transfer sheet-side adhesive layer may be provided, or both may be provided.

The peeling layer is a layer which is peeled off from the support sheet or the release layer at the time of transfer, moves to the transfer target (glass product) side, and becomes a protective layer of the pattern layer after transfer. The release layer can be omitted when the surface properties are sufficient even with only the pattern layer, or when the top coat is further applied after the transfer. Examples of the material of the release layer include acrylic resins such as methyl poly (meth) acrylate, ethyl poly (meth) acrylate, and butyl poly (meth) acrylate, vinyl chloride resins, vinyl chloride vinyl acetate copolymers. A vinyl polymer such as vinyl acetate resin, a cellulose derivative such as cellulose acetate or cellulose nitrate, a styrene resin such as polystyrene, a polyurethane resin or a polyester resin may be used alone or in combination. In addition, if necessary, inorganic fine powders (extensive pigments) such as calcium carbonate, alumina, silica, barium sulfate, fillers made of resin beads such as acrylic beads, urethane beads, polycarbonate beads, and coloring agents such as dyes and pigments. Etc. may be added. The film thickness is 1 to 1
It is about 00 μm.

The pattern layer is formed by forming a pattern from ink by printing or the like. As the ink, a resin vehicle in which a pigment, a dye, a colorant such as a matting agent, an extender pigment, a stabilizer and a solvent are appropriately mixed is used. The pattern layer is printed by a known printing method such as gravure printing, silk screen printing or offset printing using the ink. The pattern is arbitrary such as a wood grain pattern, a stone grain pattern, a stained glass pattern, an etching glass-like matte pattern, letters, figures, a solid layer on the entire surface, blur (continuous gradation), or a combination thereof.

The transfer sheet side adhesive layer is provided to improve the adhesiveness of the ionizing radiation curable resin with the adhesive. However, if the transfer layer is bonded to the ionizing radiation curable resin adhesive with sufficient adhesive force even without the transfer sheet side adhesive layer, this may be omitted. As the transfer sheet side adhesive,
Although a heat-sensitive adhesive is mainly used, other than this, a pressure-sensitive adhesive, a solvent activated adhesive or the like can also be used. The heat-sensitive adhesive exhibits adhesiveness by heating, and normally, a thermoplastic resin, an ionomer, or the like that is melted by heat to exhibit adhesiveness is used. Examples of thermoplastic resins include cellulose derivatives such as cellulose nitrate and cellulose acetate, polystyrene, styrene resins such as poly α-methylstyrene or styrene copolymers, and poly (meth).
Acrylic resins such as methyl acrylate and poly (meth) acrylate, vinyl polymers such as vinyl chloride / vinyl acetate copolymers and ethylene vinyl alcohol copolymers, rosin ester resins such as rosin and rosin-modified maleic acid resins, poly Natural or synthetic rubbers such as isoprene rubber and styrene-butadiene rubber are used. In addition, a thermosetting resin that causes cross-linking polymerization, addition polymerization, etc. by heat to be cured to develop an adhesive force is also used as a heat-sensitive adhesive. As the thermosetting resin, for example, epoxy resin, polyurethane resin, phenol resin or the like is used. As the pressure-sensitive adhesive, any of the pressure-sensitive adhesives used in known pressure-sensitive adhesive tapes and seals can be used, and examples thereof include rubber resins such as polyisoprene rubber, polyisobutyl rubber, styrene butadiene rubber, and butadiene acrylonitrile rubber. (Meth) acrylic acid ester-based resin, polyvinyl ether-based resin, polyvinyl acetate-based resin, polyvinyl chloride / vinyl acetate copolymer-based resin, polyvinyl butyral-based resin, etc. A suitable tackifier, a coumarone-indene resin, etc. are added to the resin system of 1. in an appropriate amount, and if necessary, a softening agent, a filler, an antiaging agent, a crosslinking agent, etc. are added.

As the top coat film 4, a film having good adhesion to the transfer layer and good surface properties such as abrasion resistance, chemical resistance and heat resistance is selected. For example, a thermosetting polyurethane resin, a polyester resin, an epoxy resin, a melamine resin, or the like, or an ionizing radiation-curable resin listed above in the section of the adhesive is used.

Next, the pattern transfer method of the present invention on the glass surface will be described.

First, as shown in FIG. 1 (A), a glass product 1 (a flat plate in this figure) to be a transferred body is prepared. Then, if necessary, the degreasing treatment and / or the easy-adhesion primer treatment is performed.

Next, as shown in FIG. 1 (B), the glass product 1
On the surface of the surface to which the pattern layer is to be transferred, the adhesive layer 2 of the ionizing radiation curable resin is formed by coating. For coating the ionizing radiation curable adhesive layer, various known methods, for example, gravure offset coating, roll coating, knife coating, wire bar coating, flow coating, comma coating, dip coating, spray coating, silk screen printing, Pour coat, brush coating, etc. are applied, and the thickness of the coating film when dried is about 1 to 100 μm, more preferably 5 to
It is about 30 μm.

Then, as shown in FIG. 1C, the adhesive layer 2 is irradiated with ionizing radiation 5 from the surface side (atmosphere side) to crosslink and cure the adhesive layer. What is important in this step is to make the cured state of the adhesive layer have a gradient in the thickness direction. That is, in the present invention, the adhesive layer 2 of the ionizing radiation-curable resin is cross-linked and cured so that the cross-link density increases from the surface to the inside, and the vicinity of the surface of the adhesive layer becomes non-fluid. However, it is not completely crosslinked and hardened yet, and the vicinity of the interface between the adhesive layer and the glass surface is completely crosslinked and hardened. To achieve this, the adhesive layer 2
Is irradiated with an ionizing radiation curable resin in an atmosphere containing a component that inhibits the crosslinking and curing reactions of the adhesive to cause a crosslinking polymerization reaction. The diffusion of the substrate from the atmosphere into the coating film gradually penetrates from the surface to a deep portion. The diffusion depth is approximately proportional to the square root of time. Therefore, if curing is performed before the component that inhibits the cross-linking polymerization reaction reaches the bottom of the adhesive layer completely, the crosslinking degree can be cured with a gradient as described above.

Crosslinking of this ionizing radiation curable resin adhesive,
The component that inhibits the curing reaction due to the polymerization reaction differs depending on the mechanism of crosslinking and polymerization reaction of the adhesive. In the case of the compound having a radically polymerizable unsaturated group, oxygen is used. The oxygen concentration depends on the type of compound used, the degree of polymerization (monomer, prepolymer, or polymer), the thickness of the adhesive layer, the type and intensity of ionizing radiation to be irradiated, the composition of the transfer layer, and the like. An appropriate value is selected depending on the adhesive strength (adhesive layer / glass, and adhesive layer / transfer layer) and the like, but it is usually about 5000 to 230000 PPM (weight, the same applies below). As disclosed in Japanese Patent Laid-Open No. 261572/1990, it is normally at an oxygen concentration of 5000 PPM or more that the inhibition of curing of the surface of the ionizing radiation curable resin coating film by oxygen in the atmosphere becomes negligible. Because. Since the atmosphere usually contains about 23% (230,000 PPM) of oxygen, the composition of the adhesive 2 (compound, degree of polymerization, reaction initiator, etc.) is adjusted so that the desired crosslink density is obtained at an oxygen concentration of about 230,000PPM. ), It is convenient to select the irradiation amount, etc., because it is not necessary to prepare an atmosphere of special composition or prepare a sealed container.

In the case of the compound having a cationically polymerizable functional group, steam (humidity) is used. Usually, as the water vapor concentration, a relative humidity of about 20 to 65% is used. This is because the effect of water vapor curing inhibition begins to appear when the relative humidity is about 20% or more.
This is because if it is 5% or more, the degree of curing inhibition is so large that it becomes difficult to make the surface non-fluid. The ambient temperature during irradiation is preferably about 30 ° C. or lower. This is because the curing reaction tends to be rapidly promoted when the temperature is around 30 ° C. or higher, and the inhibition of curing is offset.

The non-fluid state where the surface of the adhesive layer has not been completely crosslinked and cured means that the surface has tackiness, or that the surface is tack-free and is dry to the touch. Status is also available. In any case, the adhesive layer has unreacted functional groups remaining and is chemically adherent to the transfer layer (intermolecular force, covalent bond force, etc.) or physical adhesive force (anchoring effect, compatibility). In addition, the transfer layer (including the pattern layer) may be deformed during the period from application to adhesion or during adhesion, or the transfer layer surface may be uneven (film thickness). It is important that it is non-fluid so as not to make it non-uniform). However, when the adhesive layer 2 after transfer is not irradiated with ionizing radiation again, a crosslinking curing reaction is performed until touch-drying from the viewpoint of securing surface physical properties such as adhesion between the transferred pattern layer and the adhesive layer and scratch resistance. It is preferable to proceed. Also, after transfer, when the adhesive layer is completely cross-linked and cured by irradiation with ionizing radiation again, it is better to transfer with the adhesive layer surface kept tacky (but non-fluid) during transfer. It is preferable from the viewpoint of improving the adhesive force between the layer and the adhesive layer.

There are various methods for determining whether or not the front surface or the back surface (glass side) of the adhesive layer is completely crosslinked and cured, and an appropriate method may be selected from them. The most practical method is to record the change in the desired physical property value obtained by curing while gradually increasing the irradiation dose, and consider that the stage where the physical property value is saturated is the completely cured state. . The desired physical property values include, for example, the adhesive force between the transfer layer 32 and the adhesive layer 2 (evaluated by a tensile peel test, a cross-cut cellophane adhesive tape peel test, etc.), the adhesive force between the adhesive layer 2 and the glass product 1. (Same as above) or abrasion resistance (JIS-K-6902 Taber type abrasion test, JIS-
L-0801 Gakushin-type wear fastness test, etc.).

More specifically, the crosslink density on the surface of the adhesive layer 2 is determined as follows. That is, as shown in FIG.
When the transfer layer is transferred after the adhesive layer 2 is cured, the adhesive force between the transfer layer and the adhesive layer is extremely low and the transfer itself is impossible while the adhesive layer has fluidity. . The adhesive strength between the transfer layer and the adhesive layer increases as the irradiation amount is increased to increase the crosslink density and progress to a high-viscosity fluidized state and further to a non-fluidized adhesive state. Then, the adhesive force saturates just beyond the dry state to the touch (first saturation region). Then, as the crosslink density is further increased, the adhesive strength is reduced again. When the crosslink density is 100% or saturated, the adhesive strength is saturated again (at a level lower than the maximum value) (second
Saturated region). In this case, as the degree of curing of the surface of the adhesive layer 2 at the time of transfer, in the case where there is no irradiation again after the transfer, the area is the dry area to the touch, and the vicinity of the maximum value of the first saturated area is selected. In the case of re-irradiating after transfer to completely cure the surface of the transfer layer, it is an adhesive area where the adhesive force between the transfer layer and the adhesive layer is larger than the adhesive force between the transfer layer and the support sheet (transfer is possible). Area).

The crosslink density at the interface between the adhesive layer 2 and the glass product is determined as follows. That is, as shown in FIG. 3, in the vicinity of the interface between the adhesive layer 2 and the glass surface, the adhesive force between the glass surface and the adhesive layer is extremely low while the adhesive layer has fluidity, Further, the surface of the adhesive layer is still fluid and the transfer itself is impossible. The adhesive strength between the glass surface and the adhesive layer increases as the irradiation amount increases and the crosslink density increases, and the high viscosity fluid state and further the non-fluid adhesive state progress. Then, as the crosslink density approaches 100% or becomes saturated, the adhesive force between the glass surface and the adhesive layer becomes saturated (saturation region). Therefore, this region is considered to be a completely cured state, and the cured state of the adhesive layer / glass interface is set to fall within this saturated region. However, if a large amount of radiation is passed beyond the saturation region, distortion or internal stress may occur inside the adhesive layer, or the adhesive layer may deteriorate due to ionizing radiation,
On the contrary, the adhesive force may be reduced, so do not irradiate an unnecessarily large amount of light.

In addition, the crosslinking density (curing degree) of the adhesive layer of the ionizing radiation-curable resin is determined by infrared absorption spectroscopy (for example, in the case of a compound having an acryloyl group, 1).
640cm ^-1, 1410cm ^-1, to evaluate the absorption lines of 800cm ^-1), photo-DSC, methods such as reaction exotherm measurements can be evaluated using. Even when these methods are used, it is considered that the crosslinking and curing is completely completed at the stage where the density of the reacted functional groups reaches the theoretical saturation value or at the stage where the density of the reacted functional groups becomes saturated in the measurement data. .

The ionizing radiation curable resin, the irradiation method and the apparatus therefor are as described in the description of the adhesive layer 2.

After the adhesive layer 2 of the ionizing radiation-curable resin is cured with a gradient in the cross-linking density in the thickness direction,
Transfer is performed as in (D). This is the above-mentioned transfer sheet 3
The transfer layer 32 side of the is laminated toward the adhesive layer 2, pressure is applied,
Alternatively, the transfer layer 32 is adhered to the adhesive layer 2 by applying pressure and heat, and the support sheet 31 is peeled and removed. Thus, the transfer layer including the pattern layer can be transferred to the surface of the adhesive outermost layer.

If necessary, the top coat film 4 is applied as shown in FIG. When the top coating film is an ionizing radiation curable resin, it is crosslinked and cured by irradiation with ionizing radiation 5 as shown in FIG. 1 (F). At the same time, the surface of the adhesive layer 4 is completely hardened (to the saturated state), and the adhesive force between the adhesive layer 2 and the transfer layer 32 is further improved.

Alternatively, although not shown, the transfer process diagram 1
After (D), the surface of the adhesive layer 4 is completely cured (to a saturated state) by further irradiating with ionizing radiation without providing an overcoat film, and the adhesive force between the adhesive layer 2 and the transfer layer 32 is increased. It may be improved.

Various transfer methods can be applied as the transfer method. If the glass product is a flat plate, the roll transfer method is typical. This is a method in which the support sheet side of the transfer sheet is pressed by an elastic roller such as rubber as shown in FIG. 1 (D). When a heat-sensitive adhesive type transfer sheet side adhesive layer is used, the heated elastic roller 7 is used and heated at the same time as pressing. When the heating amount is insufficient with only the roller, the glass plate side may be preheated and then heated and pressed by the roller.

The following method is applied especially when the glass product is in the shape of a bottle, a plate, or the like. JP-A-4-288214, JP-A-5-5778
Vacuum forming simultaneous transfer method as disclosed in Japanese Patent No. This is a transfer sheet above the transfer target (glass product).
The transfer layer is placed so as to face the transfer target side. Then, the surface of the transfer target is covered with the transfer sheet by vacuum suction from the transfer target side. If necessary, air pressure is applied from the base sheet side, or pressure is applied with an elastic film such as rubber to assist the molding of the transfer sheet on the transfer target side. When a heat-sensitive adhesive type transfer sheet side adhesive is used, a heated elastic film is used and heated at the same time as pressing. Lapping simultaneous transfer method. This is a lapping method, that is, Japanese Patent Publication No. 59-5190.
No. 0, Japanese Patent Publication No. 61-5895, Japanese Patent Publication No. 3-2
As disclosed in Japanese Patent No. 666, etc., it is applied to a columnar body, and when a transfer sheet is attached,
Using a pressure roller on each side of the columnar body, sequentially attach the sheets (for example, in the case of attachment to a square pole, the sheets are sequentially attached to the upper side surface, the left and right side surfaces, and the lower side. And finally to the four sides). With the transfer layer side of the transfer sheet facing the transfer target, the transfer sheet is sequentially attached to each side surface by lapping. When a heat-sensitive adhesive type transfer sheet-side adhesive is used, it is heat-bonded by heat of a heating roller or the like, and then only the base sheet is peeled off.

[0045]

In the pattern transfer method according to the first aspect of the present application, the ionizing radiation-curable adhesive layer formed on the surface of the glass product in advance is cured so that the crosslinking density has a gradient in the thickness direction prior to the transfer. . The gradient is crosslinked and hardened so that the crosslink density increases from the surface toward the inside, and the vicinity of the surface of the adhesive layer is non-fluid but not yet completely crosslinked and hardened. In this state, and in the vicinity of the interface between the adhesive layer and the glass surface, it is characterized by being completely crosslinked and cured. Therefore, during transfer, the surface of the adhesive layer does not flow and deform due to the pressure during transfer, and the breaking strength of the adhesive layer itself is larger than the peel strength between the transfer layer and the support sheet. Sometimes the transfer layer will remain on the adhesive layer side. Therefore, good transfer is possible. At the same time, the surface of the adhesive layer does not reach a saturated state of cross-linking, the cross-linking density is relatively low, and it has an unreacted functional group. Therefore, physical (anchoring effect, permeation, etc.) and chemical (bonding force between molecules, reaction) adhesiveness are sufficiently active, and the adhesive force between the transfer layer and the adhesive layer becomes good. Further, since the adhesive surface is partially cross-linked and polymerized, it has sufficient surface properties such as abrasion resistance and heat resistance as compared with the adhesive agent of the non-crosslinked thermoplastic resin. Further, since the crosslink density is completely increased (up to the saturated state) in the vicinity of the interface between the adhesive layer and the glass surface, the adhesive force between the adhesive layer and the glass surface is also good.

Next, the mechanism by which the crosslink density of the adhesive layer causes a gradient in the thickness direction will be mentioned. When the coating film of the ionizing radiation curable resin is exposed in an atmosphere having a component that inhibits crosslinking and curing of the ionizing radiation curable resin such as oxygen and water vapor, the inhibiting component diffuses and permeates from the surface of the coating film. The diffusion region permeates in the depth direction with time (generally, the diffusion depth r is r = where D is the diffusion coefficient and t is the elapsed time).
(Dt) ^1/2 is known). Therefore, by irradiating the coating film with ionizing radiation before the penetration depth of the inhibitor reaches the bottom of the coating film, the crosslink density becomes lower at the surface of the coating film and becomes higher at the deeper part of the coating film. The coating film can be cured in such a state.

In the pattern transfer method according to claim 3 of the present application, the adhesive layer is further irradiated with ionizing radiation after the transfer. Therefore, the surface of the adhesive of the ionizing radiation-curable resin is further shielded from the atmosphere in the transfer layer and further irradiated, so that the crosslink density increases. As a result, the adhesive strength between the transfer layer (including the pattern layer) and the adhesive layer is further increased, and the surface physical properties such as abrasion resistance and heat resistance of the transfer layer are further improved as compared with the invention according to claim 1. .

[0048]

[Effect] The pattern transfer method according to claim 1 of the present application has the following effects. After transfer, baking and baking at high temperature are not required, and the surface properties such as sufficient surface hardness, abrasion resistance, chemical resistance, and heat resistance are good. Sufficient adhesive strength and surface properties can be obtained by irradiation with ionizing radiation for several seconds. Since irradiation of ionizing radiation for about several seconds is sufficient, a long curing process unlike the isocyanate-curable polyurethane adhesive layer is unnecessary. Problems such as uneven curing of the adhesive layer and unevenness in synchronization with the pattern density do not occur unlike the method of laying a transfer sheet on the surface of an uncured liquid ionizing radiation curable adhesive and irradiating from the transfer sheet side. Like a method of laying a transfer sheet on the surface of an uncured liquid ionizing radiation curable adhesive and irradiating from the glass product side, poor curing of all adhesive layers, defective adhesion of pattern layer, adhesive layer, and glass surface to each other Does not occur.

The pattern transfer method according to claim 2 of the present application is
In addition to the above-mentioned effects (1) to (3), the physical properties of the surface, especially abrasion resistance, are good because of the top coating film.

The pattern transfer method according to claim 3 of the present application is
In addition to the effects (1) to (3), the adhesion between the transfer layer (including the pattern layer) and the adhesive layer is stronger.

[0051]

EXAMPLES Next, examples of the transfer sheet according to the present invention will be specifically described.

Example 1 As a base film, a biaxially stretched polyethylene terephthalate sheet (T-60 manufactured by Toray Co., Ltd.)
# 25, thickness 25 μm), 0.3 g / m ² of melamine resin-based ink (manufactured by Zainktec) is applied to the surface, and 170
The support sheet was produced by baking at 20 ° C. for 20 seconds to form a release layer. Next, a release layer, a pattern layer, and a transfer sheet side adhesive layer were formed in this order as a transfer layer on the surface of the release layer to obtain a transfer sheet. Here, the release layer was formed by applying an acrylic resin by gravure coating to a thickness of 2 μm (when dried). The pattern layer is formed by printing by a gravure printing method using a mixture of a vinyl chloride / vinyl acetate copolymer and an acrylic resin as a binder and four color inks of yellow, red, blue, and black with pigments added thereto. did. The pigment used was isoindolinone for yellow, quinacridone for red, phthalocyanine blue for blue, carbon black for black ink, and the printed pattern was stained glass. The transfer sheet-side adhesive layer was formed by applying a heat-sensitive adhesive having a mixture of nitrified cotton and an acrylic resin as a binder on the surface of the pattern layer with a gravure coater to a film thickness of 5 μm. (Thus, the transfer sheet is completed.) Next, a flat plate of soda glass having a thickness of 5 mm was prepared, and its surface was degreased with methyl alcohol and dried. Next, on the degreased surface of the glass plate, a liquid cationic polymerization type ultraviolet curable resin adhesive composed of an epoxy resin monomer was applied with a wire bar coater to a film thickness of 20 μm. Then, irradiate the ultraviolet ray from the ultraviolet curable resin adhesive side,
The adhesive layer was crosslinked and cured so that the crosslink density increased from the surface toward the inside. The area near the surface of the adhesive layer is non-fluid but is not completely crosslinked and hardened yet, and the area near the interface between the adhesive layer and the glass surface is completely crosslinked and hardened. Let In the case of this example, when an experiment was performed by changing the irradiation amount, the output was 80 as an ultraviolet source.
A high pressure mercury lamp of W / cm is used, the distance between the lamp and the adhesive layer is 10 cm, the atmosphere during irradiation is 45% relative humidity, and the temperature is 2
5 ° C, air with an oxygen content of 230000PPM (weight),
In the case where the amount of adhesive applied is 1 μm or more, the adhesive surface is dried to the touch and the transfer layer /
It was found that the adhesive force of the adhesive layer was maximized, and the adhesive force of the adhesive layer / glass was saturated. Based on the result, the curing condition was set to this condition. Next, the transfer sheet is placed on the adhesive layer-coated surface so that the transfer layer faces the ultraviolet-curable resin adhesive, and the transfer sheet is placed at 200 ° C. for 10 minutes.
Transfer was completed by passing the silicon rubber roll of kg / cm ^{2 at} a speed of 2 m / min, and then peeling off the support sheet.

Example 2 In Example 1, after the transfer was completed, the transfer layer surface was further irradiated with the same conditions as when the adhesive was cured to cure the uncured portion of the adhesive surface. Others are the same as in Example 1.

(Example 3) In Example 1, after the transfer was completed, a top coating film of a two-component curing type urethane resin composed of tolylene diisocyanate and acrylic polyol was spray-coated on the transfer layer. Others are the same as in Example 1.

(Example 4) In Example 1, as the ionizing radiation curable adhesive, a radical polymerization type ultraviolet curable resin adhesive made of a dipentaerythritol hexaacrylate monomer was used. As the irradiation conditions, an irradiation time of 1 second (other irradiation conditions are the same as in Example 1) is a condition compatible with this resin system. Others are the same as in Example 1.

(Comparative Example 1) In Example 1, immediately after the adhesive was applied to the glass surface, the surface of the adhesive layer was covered with a 38 μm-thick polypropylene film, and ultraviolet rays were applied under the condition that both oxygen and water vapor were blocked. Irradiated. Under these irradiation conditions,
It was also confirmed that the scratch resistance of the surface of the cured adhesive layer and the adhesive force of the adhesive layer / glass were saturated. (Complete curing) Others are the same as in Example 1.

(Comparative Example 2) In Example 1, a radical polymerization type UV curable resin adhesive composed of a dipentaerythritol hexaacrylate monomer was used as the adhesive. As the irradiation conditions, immediately after the adhesive was applied to the glass surface, the surface of the adhesive layer was covered with a polypropylene film having a thickness of 38 μm, and ultraviolet rays were applied under the condition that both oxygen and water vapor were blocked. It was also confirmed that under these irradiation conditions, the scratch resistance of the surface of the cured adhesive layer and the adhesive force of the adhesive layer / glass were saturated. Others are the same as Example 1.

(Comparative Example 3) In Example 1, the relative humidity of the atmosphere during irradiation was set to 85%. Others are the same as Example 1.

(Comparative Example 4) In Example 1, ultraviolet irradiation was performed from the glass side (through the glass). Other conditions are the same as in Example 1.

(Comparative Example 5) In Example 1, a radical polymerization type ultraviolet curable resin adhesive made of a dipentaerythritol hexaacrylate monomer was used as an adhesive. And UV irradiation from the glass side (through the glass)
went. Other conditions are the same as in Example 1.

(Comparative Example 6) In Example 1, the surface of the adhesive layer was covered with an uncured continuous transfer sheet immediately after the application of the adhesive, and in this state, ultraviolet irradiation was applied from the transfer sheet side ( (Through the transfer layer). After the curing, the support sheet was peeled off. Other conditions are the same as in Example 1.

(Measurement / Evaluation Method) The measurement / evaluation method will be described below.

(Adhesive force) The surface transferred to the transfer target is
The cellophane tape was adhered and then peeled to determine whether peeling occurred at the transfer layer / adhesive layer interface or the adhesive layer / glass interface. No peeling at the transfer layer / adhesive layer interface → The adhesive strength of the transfer layer / adhesive layer is ○ There is partial peeling at the transfer layer / adhesive layer interface → Transfer layer /
Adhesive strength of the adhesive layer is △ There is peeling at the transfer layer / adhesive layer interface over the entire surface → Transfer layer /
Adhesive strength of adhesive layer x No peeling of adhesive layer / glass interface → Adhesive strength of adhesive layer / glass ○ There is partial peeling of adhesive layer / glass interface → Adhesive layer /
Adhesive strength of glass is △ Adhesive layer / glass interface is peeled all over → Adhesive layer /
The adhesive force of glass was evaluated as x. The cellophane tape used is 18 mm width for industrial use manufactured by Nichiban Co., Ltd.

(Scratch resistance) The surface transferred to the transferred material was lightly rubbed with steel wool # 0000 10 times in a reciprocating manner to determine whether or not a change in appearance such as a scratch occurs on the surface. No scratches are found on the pattern layer → ○ Scratches are partially found on the pattern layer → △ Scratches are entirely found on the pattern layer → ×

[0065]

[Table 1]

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing typical steps of a pattern transfer method of the present invention. (A) Preparation of glass product (B) Application of ionizing radiation curable resin adhesive (C) Crosslinking and curing of adhesive by irradiation of ionizing radiation (D) Transfer (E) Topcoat coating (F) Re-irradiation of ionizing radiation

FIG. 2 is a conceptual diagram showing an increase in crosslink density of an adhesive layer due to irradiation of ionizing radiation and a change in adhesive strength of a transfer layer / adhesive layer.

FIG. 3 is a conceptual diagram showing an increase in the crosslink density of the adhesive layer and a change in the adhesive force of the adhesive layer / glass due to irradiation with ionizing radiation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass product 2 Adhesive layer of ionizing radiation curable resin 3 Transfer sheet 31 Support sheet 32 Transfer layer 4 Top coat film 5 Ionizing radiation 6 Atmosphere 7 Elastic roller

Claims (3)

[Claims] 1. A method for transferring a pattern onto a glass surface, which comprises the following steps; a step of coating an adhesive layer of an ionizing radiation curable resin on the surface of a glass product, and then a surface side of the adhesive layer. From the surface of the adhesive layer to crosslink and cure the adhesive layer so that the crosslink density increases from the surface to the inside, and the surface of the adhesive layer is still non-fluid. A step of completely crosslinking and curing, and a state of completely crosslinking and curing the vicinity of the interface between the adhesive layer and the glass surface, and then forming a transfer layer including at least a pattern layer on the support sheet. Preparing a transfer sheet, and stacking the transfer sheet so that the transfer layer side of the transfer sheet is in contact with the adhesive layer surface side, then the transfer layer is adhered to the adhesive layer, and then the supporting Only the body sheet is peeled and removed, and the transfer layer is contacted. The process of transferring to the adhesive layer. 2. A method for transferring a pattern onto a glass surface, which further comprises the step of applying an overcoat film on the surface of the transfer layer after the step of claim 1. 3. The step of irradiating ionizing radiation to completely crosslink and cure the surface of the adhesive layer after the final step of claim 1 or claim 2, Pattern transfer method.