JPH08192566A - Transfer sheet - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] Covering the exterior surface of the transfer material that has a three-dimensional shape, such as a cabinet of light electrical equipment, an interior member of an automobile, etc., with a sheet by vacuum press molding or pressure molding. After molding
Provide a transfer sheet used for painting and decoration. A transfer sheet comprising a substrate sheet 1 and a transfer layer having an adhesive layer 4 exposed on the outermost surface, the adhesive layer 4 comprising:
A large number of fine particles coated with an adhesive contained therein are projected from the surface of the adhesive layer 4, and the center line average roughness (Ra) of the adhesive layer 4 is 0.3 to 1.2 μm and the maximum of the surface is A transfer sheet having a height (Rmax) of 2.5 to 8.0 μm.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention covers and molds a sheet on the exterior surface of a transfer body having a three-dimensional shape such as a cabinet of light electric equipment, an interior member of an automobile, etc. by a vacuum press molding method, a pressure molding method or the like. The present invention relates to a transfer sheet used later for painting or decoration.

[0002]

2. Description of the Related Art Conventionally, in a cover molding transfer method such as a vacuum press molding method or a pressure molding method, when the transfer sheet is transferred onto the surface of the transfer target, the surface of the transfer target is brought into contact with the surface of the adhesive layer of the transfer sheet. Then, it is heated and pressed while degassing the air existing between the transfer target and the transfer sheet in a vacuum state. In this case, however, some of the air tends to remain (air trap), so the blister However, defects such as transfer omission occur and the external appearance deteriorates. Heretofore, there are a method of previously forming fine irregularities on the transferred body by painting or molding, a method of providing a large number of small holes penetrating the entire transfer sheet, and the like. Further, in Japanese Patent Laid-Open No. 51-45137, there is a feature that deaeration is performed by using a heating sheet in which fine ridges or grooves are provided on the adhesive surface. Furthermore, the actual development Sho 5-22947
Then, the label for in-mold molding is such that the heat-sealable resin layer has a valley depth of 4 to 8 μm and is embossed with a thickness of 1/3 or more of the thickness of the heat-sealable resin layer. It has the feature of eliminating the air pocket.

[0003]

In the method of forming fine irregularities on the surface of the transfer object by painting or molding in advance, if it is too small, the effect is not obtained, and if it is too large, transfer failure occurs or appearance becomes poor. . Since the number of processes is increased and special processing is applied to molds and the like, the cost required for decoration is considerably high. There may be variations in the size of the unevenness, which may result in missing of the pattern locally or poor adhesion.

In the method of providing a large number of small holes penetrating the entire transfer sheet, a decorative layer having a large number of small holes is formed, resulting in a poor design. In addition to increasing the number of processes, it may cause ink residue (foreign matter),
It is inferior in cost and quality.

According to Japanese Patent Laid-Open No. 51-45137, in a heating sheet having fine ridges or ridges on the adhesive surface, the ink layer is peeled off from the substrate film in the embossing process, or foreign matter is attached to cause a transfer failure. As compared with the present invention, it is difficult to form uniform and fine irregularities, irregularities appear on the surface of the decorative layer, and the adhesiveness becomes unstable. The embossing conditions are narrow and the quality is not stable.

Further, in Japanese Utility Model Laid-Open No. 5-22947, the heat-sealable resin layer is embossed with a valley depth of 4 to 8 μm, which is 1/3 or more of the thickness of the heat-sealable resin layer. In-mold molding labels that have been used have the same problems as those described in JP-A-51-45137 and have irregularities of 4 to 8 μm, and it is necessary to perform sufficient heating and pressure to eliminate these irregularities during transfer. In addition to the problem that the ink sticks to the base film to cause a defective design, heat transfer distortion occurs on the transferred material.

Therefore, according to the present invention, it is not necessary to perform a process for forming fine irregularities on a transfer target before transfer, and it is not necessary to provide a large number of small holes penetrating the transfer sheet, and further, the transfer sheet is adhered. There is no need to perform embossing as a method of forming irregularities on the surface of the layer, and there is no air pocket between the transfer target and the transfer sheet during transfer, so painting or painting without causing defects such as blister and ink loss It is an object of the present invention to provide a transfer sheet that can be decorated on a transfer target.

[0008]

In order to solve the above problems, the inventors of the present invention have a transfer sheet of the present invention in which a transfer layer having an adhesive layer exposed on the outermost surface is laminated on a base sheet. In the transfer sheet, the adhesive layer is formed by protruding a large number of fine particles coated with the adhesive in the adhesive layer from the surface, and the center line average roughness (Ra) of the surface of the adhesive layer is 0.3 to 1.
2 μm, maximum surface height (Rmax) is 2.5-
It is characterized in that it is 8.0 μm.

In the transfer sheet of the present invention, the transfer layer (a layer which is separated from the base material sheet and is transferred to the transferred material) is an adhesive layer exposed on the outermost surface. A release layer and a pattern layer are provided. Further, a pattern layer having adhesiveness, that is, an adhesive layer having pattern forming property can be provided.

In principle, the material for the substrate sheet may be any as long as it has releasability from the transfer layer used in this type of transfer sheet, and its thickness is usually 5 to 200 μm.
m is preferable, and more preferably 19 to 50 μm. Specific examples of the material of the base sheet include polyethylene terephthalate, polybutylene terephthalate, polyester resins such as polyethylene terephthalate / isophthalate copolymer, polyethylene, polypropylene, polyolefin resins such as polymethylpentene,
Polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, polyfluoroethylene resin such as ethylene / tetrafluoroethylene copolymer, nylon 6 nylon 66
Polyamide resin such as polyvinyl chloride, vinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, polyvinyl alcohol and other vinyl resins, cellulose triacetate, cellophane and other cellulose resins, polymethylmethacrylate Examples include acrylic resins such as polyethylmethacrylate and polybutylacrylate, impact-resistant polystyrene, polycarbonate, polyarylate, and polyimide, but they do not melt due to heat during transfer, and they stretch according to the elongation of the pattern layer. The material is not particularly limited as long as it is possible. In addition, it is possible to change the luster entirely or partially by printing, coating or the like using an ink containing a matting agent that adheres closely to the substrate sheet.

The adhesive layer is mainly composed of fine particles and a binder. As the binder, a heat sensitive adhesive or a pressure sensitive adhesive can be used, and the type of the resin can be selected from a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin. Among them, acrylic resin, acrylic
Hot melt resins such as styrene copolymer resin, vinyl chloride / vinyl acetate copolymer resin, polyurethane, chlorinated rubber, cyclized rubber, and chlorinated polypropylene are preferable.

The fine particles which are the constituents of the adhesive layer include
Inorganic particles, organic particles and mixtures thereof can be used. Specifically, pigments, silica, acrylic beads,
Polycarbonate beads, urethane beads, nylon beads, metal powder, etc. can be used. The particle size of these fine particles may be 2 to 20 μm, preferably 1 to 10 μm. Further, it is preferable to add 1 to 40 parts by weight of fine particles to 100 parts by weight of the binder. By adding the above-mentioned fine particles, the center line average roughness (Ra) of the surface of the adhesive layer is
It becomes 0.3 to 8.0 μm. Here, the particle size of the fine particles is 2
If it is smaller than μm, the surface roughness due to addition is 0.3.
Since it is less than μm, it is not possible to prevent air pockets that occur between the transfer sheet and the transfer target during transfer. Further, when the particle size of the fine particles is larger than 20 μm, the contact between the transfer sheet and the transfer target is not dense, and transfer unevenness during transfer is likely to occur. The uneven surface hinders the design. When the amount of fine particles added is less than 1 part by weight, the surface roughness is 0.3 μm.
Therefore, it is not possible to prevent the accumulation of air generated between the transfer sheet and the transfer target during transfer. If the amount of the fine particles added is 40 parts by weight or more, the adhesiveness at the time of transfer will be poor.

On the release surface of the substrate sheet, a release layer, which constitutes the surface layer of the transfer layer to be transferred to the transfer medium, is formed, if necessary. That is, the release layer serves as a surface layer of the transfer layer that remains on the transfer target side when the base material sheet is released from the transfer sheet after the transfer step, and the transfer layer is held on the base material before the transfer and after the transfer. Has the function of facilitating the peeling between the base material sheet and the transfer layer and further protecting the transferred pattern layer. As the resin material constituting the release layer, thermoplastic resin, thermosetting resin, ionizing radiation curable resin can be used. For example, acrylic resin such as polymethylmethacrylate, polyurethane resin, vinyl chloride / vinyl acetate Polymer resin, unsaturated polyester, chlorinated rubber, resin such as cyclized rubber, isocyanate compound and polyol compound, prepolymer having acryloyl group or methacryloyl group, monomer having acryloyl group or methacryloyl group, and 2 selected from the above Mixtures of more than one can be used. The thickness of the release layer is usually 1.0
To 4.0 μm, preferably 1.5 to 3.0 μm.

The pattern layer is to add design characteristics to the transferred material by transfer of the transfer layer. Each of the pattern layer provided with a pattern and a pattern, or the whole ink layer (solid layer) or two of them. Composed of multiple layers. This pattern layer is
It is formed by printing or applying an ink in which a colorant such as a dye or a pigment is added to a resin binder.

As the binder resin material for this pattern layer, a thermoplastic resin, a thermosetting resin, or an ionizing radiation curable resin can be used. For example, an acrylic resin such as polymethylmethacrylate, a polyurethane resin, vinyl chloride / acetic acid. Vinyl copolymer resin, unsaturated polyester, chlorinated rubber, resins such as cyclized rubber, isocyanate compounds and polyol compounds, prepolymers having an acryloyl group or methacryloyl group, monomers having an acryloyl group or a methacryloyl group, and selected from the above. Mixtures of two or more can be used. It is preferable that the resin be a resin that stretches in accordance with the local stretching that occurs during vacuum forming at room temperature.

As the pattern layer, it is also possible to form a glittering layer in which a glittering pigment such as aluminum powder or mica coated with tan oxide is dispersed in the binder.

As the picture pattern, a wood grain pattern, a stone pattern, characters, figures, a solid layer, or a combination thereof may be used.

In the ionizing radiation-curable resin used in the above-mentioned adhesive layer, release layer and pattern layer, acetophenones, as a photopolymerization initiator, when being cured by ultraviolet rays,
Benzophenones, Michler benzoyl benzoate,
Thioxanthones and the like can be mixed and used.

The ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing and cross-linking a molecule, and usually an ultraviolet ray or an electron beam is 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, a black light lamp, and a metal halide lamp can be used. As the electron beam source, various electron beam accelerators such as Cockloft-Walton type, Van de Graft type, resonant transformer type, insulating core transformer type, or linear type, dynamitron type, high frequency type,
100-1000 KeV, preferably 100-300
A device that irradiates an electron having an energy of KeV can be used.

Various materials such as resin, metal, glass, ceramics, and wood can be used as the transferred material. The form of the transferred material is a plate, a sheet, a three-dimensional molded product, or the like.

As the transfer method, it is the following method that can fully utilize the characteristics of the transfer sheet of the present invention. Japanese Patent Laid-Open No. Hei 4
-288214, vacuum forming simultaneous transfer method as disclosed in JP-A-5-57786. In this, a transfer sheet is placed above the transfer target so that the transfer layer faces the transfer target side. Then, vacuum suction is performed from the transfer target side to help cover the transfer target surface with the transfer sheet. When a heat-sensitive adhesive is used as the adhesive, a transfer method in which the transfer sheet is coated with the transfer sheet at the same time as or after the transfer sheet is heated with a heater to develop adhesiveness, or a heated method is used. This is a transfer method in which a molded rubber is pressed to develop adhesiveness.

Another transfer method that can make full use of the characteristics is an injection molding simultaneous transfer method as disclosed in Japanese Patent Publication No. 2-4080, Japanese Patent Publication No. 4-19924, and the like. in this case,
It is also possible to perform the same treatment using a binder that does not separate from the base sheet on the base sheet that is opposite to the transfer ink layer, that is, on the side that contacts the mold. First, a transfer sheet is inserted between the female mold and the male mold so that the transfer layer faces the male mold side having the ejection holes. After pre-molding the transfer sheet on the surface of the female mold as needed, after closing both molds, injecting the molten resin from the injection hole into the cavity (molding cavity) between both molds, and cooling and solidifying the injected resin In this method, both molds are opened, the molded product and the transfer sheet in close contact with the molded product are taken out from the mold, and only the releasable base sheet is peeled off, leaving only the transfer layer on the molding side.

Further, as disclosed in JP-B-59-51900, JP-B-61-5895, JP-B-3-2666, etc., when a sheet is attached to a columnar body, each side surface of the columnar body is bonded. The sheets are sequentially laminated using a pressing roller (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 4 There is a lapping method. In this method, the adhesive layer side of the transfer sheet is directed to the transfer target, the transfer sheets are sequentially attached to the respective side surfaces, the adhesive layer is adhered by heating or the like, and then only the base sheet is peeled off.

[0024]

According to the present invention, in a transfer sheet comprising a base sheet and a transfer layer having an adhesive layer exposed on the outermost surface, a large number of fine particles coated with an adhesive contained in the adhesive layer are added to the transfer layer. The adhesive layer has a center line average roughness (Ra) of 0.3 to 1.2 μm and a maximum surface height (Rmax) of 2.5 to 8.0 μm. Since it is a transfer sheet to be transferred, when the transfer sheet is transferred onto the surface of the transfer target in a cover molding transfer method such as a vacuum press molding method or a pressure molding method, the surface of the transfer target is brought into contact with the adhesive layer surface of the transfer sheet. Then, when heated and pressurized while deaerating the air existing between the transfer target and the transfer sheet in a vacuum state, no air pockets are created and defects such as blister and transfer omission occur. It is possible to apply the decoration and decoration to the transfer target without Wear.

[0025]

EXAMPLE Next, an example of the transfer sheet according to the present invention will be specifically described with reference to FIG. FIG. 1 is a sectional view of the transfer sheet of the present invention.

(Examples 1 to 3) A 25 μm thick moldable polyethylene terephthalate film (Lumirror X45 manufactured by Toray) was used as the substrate sheet 1, and an acrylic resin-based peeling varnish (manufactured by Zinc Tech) was used on the surface thereof. Apply
The release layer 2 having a thickness of 2.5 μm was formed by drying at 80 ° C. for 0.5 second. Next, a wood grain pattern layer 3 was formed on the release layer 2 by gravure printing with a pattern layer ink (UPV manufactured by Showa Ink Mfg. Co., Ltd.) whose binder was urethane vinyl chloride vinyl acetate resin. Next, an adhesive having an acrylic resin (HS32 White, manufactured by Showa Ink Industry Co., Ltd.) and silica (manufactured by Fuji Silysia, Syroid) as a blend shown in Table 1 was prepared. These adhesives were applied on the above-mentioned pattern layer and dried at 105 ° C. for 0.5 seconds to obtain an adhesive layer 4 having a thickness of 5 μm.

Using the transfer sheet thus prepared, a three-dimensional transfer target was simultaneously decorated on the outer side surface and bottom surface of a cylindrical cup molded of polystyrene resin. The surface roughness of the transferred material was 0.15 μm and 1.18 μm. As a procedure, first,
The transfer sheet was placed so that the adhesive layer wrapped around the outside of the cup, and the transfer sheet was stretch-molded by vacuum suction at room temperature of 20 ° C. to fit the outside of the cup. In this state, a silicon molded rubber heated to 170 ° C. was pressed from the side of the base material sheet for about 3 seconds to be heated and pressed, and then the base material sheet was peeled off. As a result, the cup including the three-dimensional curved surface was excellently decorated without cracks or cracks in the transfer layer. Table 3 shows the evaluation results of the transfer sheet.

(Comparative Examples 1 to 3) For the adhesive layers described in Examples 1 to 3, adhesives containing the acrylic resin and silica, which are the constituents of the adhesive layers, in the composition shown in Table 2 were prepared to prepare the adhesive layers of the pattern layers. Apply on top and dry at 105 ° C for 0.5 seconds to a thickness of 5μ
m adhesive layer was obtained. Subsequent steps were the same as in Examples 1 to 3 to obtain transfer sheets. Example 1 is also applied to the transfer process.
Was performed in the same manner as ~ 3. The evaluation results are shown in Table 3. (Below margin)

[0029]

[Table 1]

[0030]

[Table 2]

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

(Centerline average roughness [Ra] and maximum height [Rmax]) According to JIS B0601-1982.

(Observation of Transferred Body Side After Transfer) The appearance of the transferred body side after transfer and after the cellotape peeling test is visually observed. The evaluation results are shown in Table 3. (Below margin)

[0034]

[Table 3]

[0035]

Since the present invention is constructed as described above, it has the following effects.

In a coating molding transfer method such as a vacuum press molding method and a pressure molding method, when the transfer sheet is transferred to the surface of the transfer object, the surface of the transfer sheet is brought into contact with the surface of the adhesive layer of the transfer sheet, and then a vacuum is applied. When heated and pressurized while deaerating the air that exists between the transfer target and the transfer sheet, it does not create air pockets and does not cause defects such as blister and transfer drop. Or the decoration can be applied to the transferred material.

[Brief description of drawings]

FIG. 1 is a sectional view of a transfer sheet for explaining an embodiment of the present invention.

[Explanation of symbols]

 1 Base Material Sheet 2 Release Layer 3 Design Layer 4 Adhesive Layer

Claims (1)

[Claims] 1. A transfer sheet comprising a base sheet and a transfer layer having an adhesive layer exposed on the outermost surface, wherein a large number of fine particles coated with an adhesive contained in the adhesive layer are transferred from the surface of the adhesive layer. The center line average roughness (R
a) is 0.3 to 1.2 μm and the maximum surface height (Rm
ax) is 2.5 to 8.0 μm.