JPH04301491A - Mold release sheet and transfer sheet - Google Patents

Abstract

PURPOSE:To provide a mold release sheet, in which the release properties of a mold release layer can be controlled to proper release strength and release properties of which are not changed with time, and a transfer sheet. CONSTITUTION:A mold release layer, in which silicone resin fine particles having network structure consisting of siloxane bonds extended in a three- dimensional manner and mean particle size of 0.1-15 mum are included, is formed onto the surface of a base material sheet in a mold release sheet, and a transfer layer composed of one or more layers selected from a peel ply, a pattern layer, a decorative layer and an adhesive layer is laminated on said mold release sheet in a transfer sheet. There is no possibility, in which the silicone resin fine particles used for the mold release layer are bled on a surface with time owing to a solid, and the mold release sheet, in which the particle size of the silicone resin fine particles is selected arbitrarily and irregularities are given to the surface, is formed, and said mold release sheet can be utilized as a shaped film.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release sheet and a transfer sheet.

0002

BACKGROUND OF THE INVENTION Conventionally, a sheet having a release layer provided on the surface of a base sheet has been used as a release sheet for processing paper and the like. Process paper is used, for example, as a support sheet for vinyl resin plastisol in the production of vinyl wallpaper, and as an oxygen shielding sheet to block oxygen in the air during the curing of polyester resin liquid in the production process of polyester decorative laminates. . Furthermore, a transfer sheet using the above-mentioned release sheet is known, and the transfer sheet has a structure in which a transfer layer consisting of a release layer, a decorative layer such as a pattern, an adhesive layer, etc. is laminated on the release sheet. It is used to transfer a transfer layer to an object to be transferred, and to easily apply a design such as a pattern to the surface of a molded product or the like. Conventionally, in a release sheet, silicone oil or the like has been added to the release layer in order to improve the releasability of the release layer. Furthermore, as a release sheet for a transfer sheet, a sheet in which the above-mentioned silicone oil is added to the release layer has been used.

0003

[Problems to be Solved by the Invention] However, with the above conventional release sheet, the silicone oil added to the release layer bleeds out to the surface, and the peel strength changes over time, making it difficult to release the sheet during use. There is a problem in that the sheet peels off when it is necessary not to peel it off, making it impossible to achieve the intended purpose. For example, in the case of a conventional transfer sheet using a release sheet with a release layer added with silicone oil, it is difficult to control the releasability, and the transfer sheet is laminated on the object to be transferred and heat and pressure are applied. There were problems such as the release sheet peeling off before the transfer was completed, making it impossible to transfer to an accurate position. In order to prevent silicone oil from bleeding out as mentioned above, functional groups are introduced into silicone oil, and modified silicone oil is copolymerized with polyether, etc. to increase compatibility with the resin that forms the release layer. Attempts have been made to control bleeding from the release layer using silicone oil and the like. However, the above-mentioned attempts either had no effect on preventing bleeding to the surface, or conversely, had no releasability at all, and were unable to demonstrate their performance as a release sheet. I couldn't get it. The present invention aims to solve the above-mentioned drawbacks of the prior art, and provides a release sheet that can control the releasability of the release layer to have an appropriate peel strength and whose releasability does not change over time, and a transfer sheet. It is intended to provide a foil.

0004

[Means for Solving the Problems] As a result of intensive studies in view of the above-mentioned problems, the present invention has been developed by adding specific silicone resin fine particles to the mold release layer, which makes it possible to appropriately control the releasability. The present invention was completed by discovering that it is possible to form a release sheet that does not change over time. That is, the release sheet of the present invention has a release layer formed on the surface of the base sheet containing silicone resin fine particles having an average particle diameter of 0.1 to 15 μm and having a network structure consisting of three-dimensionally extended siloxane bonds. has. Furthermore, in the release sheet, the release layer may contain a matting agent in an amount of 0.1 to 10% by weight. Further, the transfer sheet of the present invention has a structure in which a transfer layer consisting of one or more layers selected from a release layer, a pattern layer, a decorative layer, and an adhesive layer is laminated on the above-mentioned release sheet.

[0005] In the release sheet, the silicone resin fine particles have a network structure in which siloxane bonds extend in three dimensions, and have an intermediate structure between inorganic and organic in which one methyl group is bonded to a silicon atom. It is something that you have. Such silicone resin fine particles (silicone resin fine powder) are called "Tospearl" (trade name sold by Toshiba Silicone)
, and "KMP-590" (trade name sold by Shin-Etsu Chemical Co., Ltd.) can be used.The average particle diameter of the silicone resin fine particles used is 0.1 to 15 μm, and the release sheet The average particle size can be selected as appropriate depending on the surface shape.For example, in the case of "Tospearl 120" as an example of the specific properties of silicone resin fine particles, the appearance is true spherical, white fine particles, and the average particle size is 2.0μm, moisture content 2% or less (105°C, 60 minutes),
pH is 7.5 (2% dispersion in methanol:water = 1:1 solution), true specific gravity 1.32 (25°C), bulk specific gravity 0.3
5. Specific surface area is 30m2/g, linseed oil absorption is 75m
It has physical properties of l/100g.

The amount of silicone resin fine particles added to the mold release layer can range from 1 to 50% by weight, but is preferably from 5 to 15% by weight. If the amount added is less than 1%, release properties will not be exhibited and peeling will become difficult, and if the amount added exceeds 50%, release properties will be excessively developed and the base sheet of the release sheet and the release layer will be separated. The adhesion of the film decreases, making it difficult to manufacture a release sheet.

[0007] As the base sheet, a film having a thickness of about 5 to 200 μm can be used. Examples of materials include polyethylene terephthalate, polybutylene terephthalate,
Polyester resins such as polyethylene terephthalate isophthalate copolymers, polyethylene, polypropylene,
Polyolefin resins such as polymethylpentene, polyfluorinated ethylene resins such as polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polyamides such as nylon 6 and nylon 66, Vinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, vinyl polymer such as vinylon, cellulose resin such as cellulose acetate, cellophane, polymethane Acrylic resins such as methyl acrylate, polyethyl methacrylate, and polybutyl acrylate; monolayers or multiple laminates of synthetic resin films or sheets such as polystyrene, polycarbonate, polyarylate, and polyimide; or high-quality paper; Examples include tissue paper, glassine paper, and parchment paper.

The release layer may be formed by forming a coating film of a paint obtained by adding the above-mentioned silicone resin fine particles to a known vehicle such as acrylic resin, cellulose resin, vinyl resin, etc. For example, coating a composition added to a resin such as a fluororesin, a melamine resin, a polyolefin resin, a polyfunctional acrylate crosslinked by ionizing radiation, a polyester resin, an epoxy resin, or a two-component curing polyurethane resin,
Alternatively, it can be formed by forming a film using extrusion coating or the like. The thickness of the release layer is formed to be 1 to 20 μm.

In the present invention, a matting agent can be added to the above-mentioned mold release layer to make the surface of the mold release layer uneven. As the matting agent, for example, fine powder of calcium carbonate, barium sulfate, silica, barium carbonate, alumina, glass balloon, polyethylene, etc. with a particle size of about 1 to 5 μm is used. It should be noted that the release layer can be made to have a certain degree of surface unevenness by adding silicone resin fine particles without adding a matting agent in particular.However, by further adding the above-mentioned matting agent, It becomes possible to arbitrarily adjust the unevenness. In addition, as a means for imparting unevenness to the surface of the release sheet,
The above-mentioned release layer may be formed using a sheet in which the above-mentioned matting agent is kneaded into the base sheet in advance and surface irregularities are formed on the base sheet itself.

The mold release sheet of the present invention can be used as a process paper for PVC sol casting, a molding film for molding and shaping thermosetting resin decorative laminates such as melamine decorative laminates, and other various molding sheets.
It can be suitably used for hot stamping, thermal transfer methods such as injection molding simultaneous transfer method, solvent activated transfer, and release sheets for various other transfer papers (which forms irregularities on the surface of the transfer layer at the same time as transfer).

Next, another invention, a transfer sheet using the above-mentioned release sheet, will be explained. The transfer sheet of the present invention uses the above-mentioned release sheet as a releasable base sheet, and is provided with layers such as a release layer, a pattern layer, a decorative layer such as a metal vapor deposition layer, an adhesive layer, etc. on the release sheet. A transfer layer is formed by selecting one or more of the above layers depending on the conditions.

[0012] The above-mentioned release layer has a release property from the release sheet, and after the transfer is completed, a resin composition is selected that has desired physical properties as a surface protective layer of the transfer layer. The resin forming the release layer may be a thermoplastic resin, but particularly when surface scratch resistance, chemical resistance, and stain resistance are required, thermosetting resins or ionizing radiation-curable resins are usually used. The film thickness is also selected depending on the desired physical properties, etc., but is usually 0.1 to 10 μm.
It is. The above-mentioned pattern layer and decorative layer may be provided on the entire surface or partially in a pattern, and the patterns include designs of natural materials such as wood grain, stone grain, cloth grain, letters, figures, symbols, various abstract patterns, etc. Either is fine. The adhesive layer is a layer for transferring and adhering the transfer layer to the object to be transferred, and is selected from heat-sensitive adhesives, solvent-activated adhesives, ionizing radiation-curable adhesives, etc. depending on the application. Incidentally, when the transfer layer other than the adhesive layer itself, such as the pattern layer and the release layer, has sufficient adhesiveness, the adhesive layer may be omitted. The heat-sensitive adhesive exhibits adhesive properties when heated, and thermoplastic resins, ionomers, etc. are usually used.

[0013]

[Examples] The present invention will be described in more detail below with reference to specific examples. Examples 1 to 4 A biaxially stretched PET film (manufactured by Toray Industries, Ltd.: E-86) was used as a base film, 100 parts by weight of an acrylic polyol-based main agent (manufactured by Dainichiseika Chemical Industry Co., Ltd.: TM-CCM), an isocyanate curing agent (manufactured by Dainichiseika Industries, Ltd.: TM-CCM), Kakogyo: TM-DH) 10 parts by weight,
A paint containing 1 part by weight of a matting agent mixed with silicone resin fine particles (Tospar 120 manufactured by Toshiba Silicone) in the amount shown in Table 1 was applied to the surface of the base film using a reverse roll coating method. After that, it was cured at 50°C for 2 days to form a release layer, and a release sheet was manufactured. Next, a release layer made of acrylic (Hakuri 46-7 manufactured by Showa Ink Co., Ltd.) was formed on the release layer of the release sheet at a coating amount of 2.0 g/m2, and wood grain was further applied on the release layer. A pattern layer made of a mixture of vinyl chloride-vinyl acetate copolymer and acrylic (BC heat-resistant ink manufactured by Showa Ink) is formed on the pattern, and then a PVC/vinyl acetate type (PVHS manufactured by Showa Ink) is further formed on the pattern layer.
A transfer sheet was manufactured by providing an adhesive layer with a thickness of 3.0 g/m2. The above-mentioned release layer, pattern layer, and adhesive layer were all formed by gravure coating. The obtained transfer sheet was placed in a mold to perform in-mold molding, and the transfer was performed simultaneously with the molding. As a result, good transfer could be performed in all cases. Furthermore, the peel strength between the release sheet and release layer of the transfer sheet was measured. The measurement results are shown in Table 1. Comparative Examples 1 to 5 For comparison, silicone resin fine particles used in Examples 1 to 4 were not used, and silicone oil was not added as shown in Table 1 (Comparative Example 1), or various modifications shown in Table 1 were used. Examples 1 to 5 except for adding silicone oil (Comparative Examples 2 to 5)
A release sheet and a transfer sheet were manufactured in the same manner as in Example 4, and the peel strength was measured. The measurement results are shown in Table 1.

[0014]

[Table 1] *1: Product name of commercially available silicone resin fine particles manufactured by Toshiba Silicone Co., Ltd.

[0015]

Effects of the Invention As explained above, the release sheet of the present invention has a release layer containing fine silicone resin particles having an average particle diameter of 0.1 to 15 μm and having a network structure consisting of three-dimensionally extended siloxane bonds. Because the structure is formed on the surface of the base sheet, compared to conventional release sheets that use silicone oil for the release layer, the silicone resin fine particles are not liquid like silicone oil but solid. Since it does not move inside the release layer, there is no risk of it bleeding from the inside of the release layer to the surface over time and changing the peel strength over time, unlike silicone oil, so it is stable. It can exhibit excellent releasability. Further, by selecting the particle size of the silicone resin fine particles, it is possible to easily form an arbitrary uneven surface on the surface of the release sheet, so that it can be used as a shaping film. Further, a matting agent is added to the release layer of the release sheet of the present invention in an amount of 0.1 to
When the content is 10% by weight, it has the effect that the uneven shape of the surface of the release sheet can be adjusted more finely. The transfer sheet of the present invention adopts a structure in which a transfer layer is formed on the surface of the above-mentioned release sheet, so it has more stable peeling than a transfer sheet that uses conventional silicone oil for the release layer of the release sheet. It exhibits excellent performance and has the effect of being able to perform good transfer without the problem of the transfer layer peeling off during transfer work or storage.

Claims (3)

[Claims] 1. A release layer containing fine silicone resin particles having an average particle diameter of 0.1 to 15 μm and having a network structure consisting of three-dimensionally extended siloxane bonds is formed on the surface of the base sheet. Release sheet. 2. The release sheet according to claim 1, wherein the release layer contains 0.1 to 10% by weight of a matting agent. 3. A transfer layer comprising one or more layers selected from a release layer, a pattern layer, a decorative layer, and an adhesive layer is laminated on the release sheet according to claim 1. transfer sheet.