WO2008147037A1

WO2008147037A1 - Transfer sheet having excellent cubic effect

Info

Publication number: WO2008147037A1
Application number: PCT/KR2008/001446
Authority: WO
Inventors: Won Seop Jin; Jong Chul Lee; Kang Youp Lee
Original assignee: Lg Chem, Ltd.
Priority date: 2007-05-25
Filing date: 2008-03-14
Publication date: 2008-12-04
Also published as: JP5296059B2; JP2010527823A; KR101048714B1; CN101687423A; KR20080103749A; CN101687423B

Abstract

The present invention relates to a transfer sheet having excellent cubic effect which is used for decorating surfaces of synthetic resin molded articles. The transfer sheet having excellent cubic effect comprises a base sheet; a release layer and a peeling layer formed sequentially on the base sheet; a glass bead layer formed on the peeling layer; and an adhesive layer formed on the glass bead layer. The glass bead layer may comprise a resin layer formed on the peeling layer and glass beads partially embedded and fixed in the resin layer, and a metal deposition layer may be formed on the glass bead layer. The glass bead layer is partially formed on the peeling layer together with a print pattern layer, a metal deposition layer may be formed on the glass bead layer and the print pattern layer or formed on only the glass bead layer formed partially on the peeling layer.

Description

Description TRANSFER SHEET HAVING EXCELLENT CUBIC EFFECT

Technical Field

[1] The present invention relates to a transfer sheet used for decorating surfaces of synthetic resin molded articles, and more specifically, a transfer sheet having an excellent cubic effect, which comprises a glass bead layer and a metal deposition layer

[2]

Background Art

[3] As a method for decorating surfaces of synthetic resin molded articles, a concurrent molding/transferring method has been conventionally used, which is molded by inserting a transfer sheet into a mold, wherein a release layer, a peeling layer, a print pattern layer, a metal pattern or metal deposition layer and an adhesive layer are formed on a base sheet. The transfer sheet employed in the concurrent molding/ transferring method has been so called a concurrent mold/transfer sheet.

[4] For example, in an injection molding process, the transfer sheet is inserted into a mold in a state where an adhesive layer of the transfer sheet is positioned at a direction in which an injected product is discharged, and the injected product flowing out in a state of melt comes becomes in contact with the adhesive layer of the transfer sheet, and so injection molded product is obtained. Finally, the base sheet of transfer sheet is peeled (released) from the injection molded product, whereby a synthetic molded article in which the furthermost layer acts as the peeling layer of the transfer sheet is obtained, and the base sheet and the release layer are stripped.

[5] In conventional transfer sheets comprising a metal pattern layer or a metal deposition layer, a metal thin layer is formed on an entire surface of the release layer or partially formed on a surface of the release layer. For example, in case of metal vapor deposition, it may be formed in a thickness of as much as 40 to 60 nm by using a metal such as aluminum, nickel, copper, platinum, chrome, iron, and titanium, to represent an inherent color of metal.

[6] When the metal deposition layer is partially formed, aqueous coating agent is applied on a surface of a region except an area on which a metal deposition layer will be formed later, and a metal vapor deposition is performed. Then, the aqueous coating agent layer is removed by mixed solvent of alcohol/water so that a metal deposition layer is formed exactly on the desired area. [7] In addition, a transfer sheet comprising a glass bead layer and a metal deposition layer together was present. For example, in Japanese Unexamined Patent Publication No. 2005-271357 published on October 6, 2005, a transfer material is disclosed, which comprises a support sheet, a surface-protecting layer containing particles and formed on the support sheet, a sealing layer formed on the surface-protecting layer, a metal thin film layer formed on the sealing layer, and an adhesive layer formed on the metal thin film layer.

[8] In conventional sheets comprising the metal pattern layer or the metal deposition layer and particles (glass beads) as described above, the texture of metal can be represented, since the metal pattern layer or metal deposition layer was formed on a plane. However, there was the disadvantage that it had less refined sense as well as no or impaired cubic effect.

[9]

Disclosure of Invention Technical Problem

[10] The present invention is conceived to the above problems and to provide a transfer sheet having excellent cubic effect and a method for preparing the same.

[11] The present invention is intended to provide a transfer sheet having excellent cubic effect by forming sequentially a release layer, a peeling layer and an adhesive layer on a base sheet, and then forming sequentially a glass bead layer and a metal deposition layer on the peeling layer, and a method for preparing the same.

[12] Another object of the present invention is intended to provide a transfer sheet having excellent cubic effect by forming the glass bead layer consisting of a resin layer formed on the peeling layer and glass beads partially embedded in the resin layer for fixing glass beads, and a method for preparing the same.

[13] Yet another object of the present invention is intended to provide a transfer sheet having various print patterns as well as the excellent cubic effect with a texture of metal, by partially forming the glass bead layer along with a print pattern layer on the peeling layer, and a method for preparing the same.

[14]

Technical Solution

[15] To achieve the above objects, the transfer sheet according to the present invention comprises a base sheet; a release layer and a peeling layer formed sequentially on the base sheet; a glass bead layer formed on the peeling layer; and an adhesive layer formed on the glass bead layer.

[16] Here, the glass bead layer can comprise a resin layer formed on the peeling layer and glass beads partially embedded and fixed in the resin layer.

[17] Therefore, the transfer sheet having excellent cubic effect, according to the present invention comprises the base sheet, and the release layer, the peeling layer, the glass bead layer consisting of a binder resin layer and glass beads partially embedded in the resin layer and an adhesive layer formed sequentially on the base sheet.

[18] In addition, the transfer sheet having excellent cubic effect according to the present invention may further comprise a metal deposition layer formed on the glass bead layer which is formed on the peeling layer.

[19]

[20] In the transfer sheet having excellent cubic effect according to the present invention, the glass bead layer and a print pattern layer may be partially formed on the peeling layer. At this time, a metal deposition layer can be formed on the print pattern layer and the glass bead layer or can be formed on only the glass bead layer.

[21] The transfer sheet having excellent cubic effect, according to the present invention may have one or more functional layers selected from usual known functional layers such as an anchor layer, an antistatic layer, and an easy binding treatment layer for enabling release agent to be easily bonded (attached) to the base sheet.

[22] The transfer sheet having excellent cubic effect, according to the present invention, may be employed in decorating surfaces of articles to be transferred such as synthetic molded articles by various method. For example, the transfer sheet according to the present invention may decorate surfaces of articles to be transferred by usual transferring methods such as a transferring method employing a roll transcriber or an up-down transcriber, having elastic bodies of heat resistant rubber phase, as well as concurrent molding/transferring method including injection molding. Especially, the present transfer sheet can be advantageously applied as a concurrent injection mold/ transfer sheet.

[23]

Advantageous Effects

[24] The glass bead layer and various print pattern layers can be formed in the transfer sheet according to the present invention, and so the present invention has an advantage that an excellent cubic effect and various print patterns can be represented.

[25] Brief Description of the Drawings

[26] Figs. 1 to 5 are cross sectional view of the transfer sheets according to the preferred embodiments of the present invention. [27]

Best Mode for Carrying Out the Invention

[28] Hereinafter, the preferred embodiments of the present invention are explained in detail with reference to the accompanying drawings.

[29] Fig. 1 is a cross sectional view of a transfer sheet according to the first embodiment of the present invention. A transfer sheet 10 according to the present embodiment comprises a base sheet 11, a release layer 12 and a peeling layer 13 formed sequentially on the base sheet 11. The transfer sheet 10 further comprises a glass bead layer formed on the peeling layer 13 and an adhesive layer 16 formed on the glass bead layer. The glass bead layer consists of a resin layer 14 formed on the peeling layer 13 and glass beads 15 embedded in the resin layer 14. The glass beads 15 are fixed in the resin layer 14.

[30]

[31] As the base sheet 11 of the transfer sheet 10 according to the present invention, a film (sheet) such as polyethylenes, for example a polyethylene terephthalate resin, acrylics, polyvinyl chlorides, polypropylenes, polyesters, and polyamides, a copolymer film (sheet) thereof, or a metal sheet (thin film) such as aluminum and copper, a film (sheet) such as cellophane, and the like may be used. Preferably, a synthetic resin film (sheet) having good elasticity and moldability is used. Particularly, since the base sheet is subjected to several steps of printing (laminating) or coating work, poly- ethyleneterephthalate (PET) having excellent heat stability is preferable. Suitably, the base sheet has a thickness of 25 to 50 micrometer (JM), considering curve property or flexibility in a mold of articles to be transferred.

[32] The release layer 12 is a layer formed on the base sheet 11 and released with the base sheet 11 from the peeling layer 13 when the base sheet 11 is peeled off after transferring. Due to the release layer 12, the base sheet 11 can be easily peeled off from the peeling layer 13. A silicon resin, an epoxy resin, a melamine resin, a fluoro resin, and the like may be employed as materials of the release layer 12. It can be homogeneously coated by a microgravure coating method, a lip coating method and the like as a method of forming the release layer.

[33] Since the peeling layer 13 becomes the outermost layer of molded articles after transferring, it is required to have high hardness resistant to the outer wear, friction or scratching. In addition, the transfer sheet should have no problem, such as brittleness in the curved parts, on transferring it to articles to be transferred, having various curves, and concurrently molding and transferring it in a mold. A resin appropriate to these properties may include an ultraviolet or electron beam curable resin, a thermosetting resin and the like. The resin for forming the peeling layer may be used by adding, if appropriate, a pigment or a dye thereto to color it. As a method for curing the resin for forming the release layer, a one cure method, wherein it is completely cured after coating it on the release layer 12, and a dual cure method, wherein it is partially cured (generically termed as a state that it is not completely cured) after coating it and it is again completely cured through an ultraviolet (UV) radiation after molding, may be employed. A comma coating method, a roll coating method, a mi- corgravure coating method, a lip coating method and the like may be used as a method for coating the peeling layer.

[34] The glass bead layer of the transfer sheet 10 according to this embodiment of the present invention consists of the resin layer 14 formed on the peeling layer and the glass beads 15 embedded in the resin layer 14, and so the glass bead 15 are fixed in the resin layer 14. The glass bead layer may be partially formed on the peeling layer 13 together with a print pattern layer (not shown in Fig. 1).

[35] The resin layer 14 for fixing the glass beads 15 of the present invention is formed on the peeling layer 13. The resin layer 14 for fixing the glass beads 15 serves to embed the glass beads 15 therein partially and fix them. The resin layer 14 for fixing the glass beads 15 is formed from a two-component thermosetting resin composition cross-linked with a copolymer having good adhesion of an acrylic polyol, acrylate, methylmethacrylate, butylacrylate, ethylacrylate, vinylacetate and the like, and a multifunctional isocyanate or a two-component thermosetting resin composition of polyester polyol and polyisocyanate. The resin layer 14 for fixing the glass beads 15 may be formed by a bar coating method or a comma coating method and the like to have a thickness of 5 to 10 micrometer (μm) after drying.

[36] The glass beads 15 of the present invention may be embedded and fixed in the resin layer 14 with their depth of as much as 1/3 to 2/3, by forming the resin layer 14, drying it at 60 to 100⁰C for about 1 minute, dispersing the previously prepared glass beads 15 on the resin layer 14 for fixing the glass beads 15, further drying them at 100 to 180°C for about 1 minute.

[37] The glass beads 15 have a light transmitting sphere shape, in which glass marbles (glass beads) or polymer marbles (polymer beads) may be used. Polymer beads are preferable, and especially, acrylic resin beads are preferable, which may be well fixed to the resin layer for fixing glass beads. The larger the diameter of glass beads is, the better the cubic effect is. However, for transferring, it is preferably in a range of 4 to 15 micrometer (μm), and most preferably in a size of around 5 micrometer (μm).

[38] The adhesive layer 16 of the present invention, for example, in case of injection molding, is a transfer surface for forming an adhesion surface directly coming in contact with the injected product flowing out in a state of melt on molding synthetic resin products, which is a layer for obtaining good adhesion between the transfer surface and the injected resin. Such adhesive layer 15 may be applied by usually diluting an adhesive for hot melt in a diluting solvent and formed by a usual coating method such as a roll coating method, a comma coating method, a gravure coating method and a lip coating method and a printing method such as a gravure printing method and a screen printing method. The adhesive for hot melt may be used by selecting suitable thermo- sensitive or pressure sensitive synthetic resin, depending on the quality of adherend materials.

[39]

[40] Fig. 2 is a cross sectional view of a transfer sheet according to the second embodiment of the present invention.

[41] Like the transfer sheet 10 of the first embodiment, a transfer sheet 20 according to the second embodiment comprises a base sheet 21, a release layer 22 and a peeling layer 23 formed sequentially on the base sheet 21. The transfer sheet 20 further comprises a glass bead layer formed on the peeling layer 23 and an adhesive layer 26 formed on the glass bead layer. The glass bead layer consists of a resin layer 24 formed on the peeling layer 23 and glass beads 25 embedded in the resin layer 24. The glass beads 25 are fixed in the resin layer 24.

[42] The transfer sheet 20 according to the second embodiment further comprises a metal deposition layer 27 formed between the glass beads 25 of the glass bead layer and the adhesive layer 26.

[43] The metal deposition layer 27 of the second embodiment is formed on the glass bead layer. The metal deposition layer 27 may be formed by usual methods such as vacuum evaporation, sputtering deposition, and electron beam evaporation. The metal deposition layer 27 may represent each inherent texture and color of metals by using a metal such as aluminum, nickel, copper, gold, platinum, silver, chrome, iron, and titanium, and has a thickness of as much as 40 to 60 nanometer (μm). When the metal deposition layer is partially formed, the exactly desired area only may be deposited by first applying surfaces except for areas to be deposited with an aqueous coating agent, then depositing it, and washing out the aqueous coating layer, using a mixed solvent of alcohol/water.

[44] Functions of other structural elements and a method of forming thereof are the same as those of the elements in the first embodiment, and so a detailed description thereof is omitted.

[45]

[46] Fig. 3 is a cross sectional view of a transfer sheet according to the third embodiment.

[47] Like the transfer sheet 20 of the second embodiment, a transfer sheet 30 according to the third embodiment comprises a base sheet 31, a release layer 32 and a peeling layer 33 formed sequentially on the base sheet 31. The transfer sheet 30 further comprises a glass bead layer formed on the peeling layer 33, an adhesive layer 36 formed on the glass bead layer and a metal deposition layer 37 formed between the glass beads 35 of the glass bead layer and the adhesive layer 36.

[48] The glass bead layer consists of a resin layer 34 formed on the peeling layer 33 and glass beads 35 embedded and fixed in the resin layer 34.

[49] Functions of other structural elements and a method of forming thereof are the same as those of the elements in the second embodiment, and so a detailed description thereof is omitted.

[50] The transfer sheet 30 according to the third embodiment further comprises an easy binding treatment layer 38 formed between the base sheet 31 and the release layer 32.

[51]

[52] Fig. 4 is a cross section of a transfer sheet according to the fourth embodiment.

[53] Like the transfer sheets 20 and 30 of the second and third embodiments, a transfer sheet 40 according to the fourth embodiment comprises a base sheet 41, a release layer 42 and a peeling layer 43 formed sequentially on the base sheet 41. The transfer sheet 40 further comprises a glass bead layer formed on the peeling layer 43.

[54] The glass bead layer consists of a resin layer 44 formed on the peeling layer 43 and glass beads 45 embedded and fixed in the resin layer 44. The transfer sheet 40 further comprises an easy binding treatment layer 48 formed between the base sheet 41 and the release layer 42.

[55] Functions of other structural elements and a method of forming thereof are the same as those of the elements in the second and third embodiment, and so a detailed description thereof is omitted. [56] In the transfer sheet 40 according to the fourth embodiment, print pattern layers 49 and the glass bead layers consisting of the resin layer 44 and glass beads 45 are formed on the peeling layer 43. As shown in Fig. 4, each print pattern layer 49 is formed between two glass bead layers.

[57] A metal deposition layer 47 is formed on an entire structure including the glass bead layers and the print pattern layer 49 and an adhesive layer 46 is formed on the metal deposition layer 47.

[58] The print pattern layer 49 may be formed by a gravure coating method, a mi- crogravure coating method, and a rotary screen coating method, using usual print inks made of a resin such as a polyester resin, an acrylic resin, and a polyester urethane, having good adhesion with the peeling layer.

[59] In the transfer sheet 40 according to the fourth embodiment, an anchor layer (not shown) acting as a functional layer may be further formed between the peeling layer 43 and the print pattern layer 49 and/or between the print pattern layer 49 and the adhesive layer 46 to obtain good adhesion.

[60] Fig. 5 is a cross section of a transfer sheet according to the fifth embodiment of the present invention.

[61] The entire structure of the transfer sheet 50 according to the fifth embodiment is the substantially same as that of the transfer sheet 40 according to the fifth embodiment shown in Fig. 4. Accordingly, the detailed description on the entire structure of the transfer sheet 50 is omitted.

[62] A major feature of the entire structure of the transfer sheet 50 is that a metal deposition layer 57 can be partially formed on the entire structure. As shown in Fig. 5, that is, the metal deposition layer 57 is formed on only each glass bead layer (that is, glass beads 55). Accordingly, an adhesive layer 56 is formed on the metal deposition layers 57 and print patterns layers 59.

[63]

[64] In addition, in the transfer sheet according to the first to fifth embodiments of the present invention, usual known functional layers such as an anti-static layer may be further formed thereon.

[65] The transfer sheet according to the present invention may be prepared through steps of preparing raw materials including a base sheet; coating one side of the base sheet with a release agent to form a release layer; coating on the release layer with a synthetic resin solution to form a peeling layer; forming a glass bead layer at the front side on the peeling layer or partially forming a glass bead layer and a print pattern layer, respectively, on the peeling layer; and applying an adhesive on the glass bead layer formed on a surface of the peeling layer or on the glass bead layer and the print pattern layer partially formed on the peeling layer, respectively, to form an adhesive layer.

[66] The step of forming the glass bead layer of the present invention comprises the steps of forming a resin layer on the peeling layer; and partially embedding and fixing glass beads in the resin layer.

[67] The process for preparing the transfer sheet according to the present invention may further comprise the step of forming a glass bead layer on an entire surface of the peeling layer or forming a glass bead layer and a print pattern layer, and then forming a metal deposition layer thereon.

[68] The process for preparing the transfer sheet according to the present invention may further comprise the step of easy binding-treatment in which the base sheet is treated by a method such as corona treatment, and so the release agent is easily adhered to the base sheet.

[69] The transfer sheet according to the present invention as above may decorate surfaces of various kinds of articles to be transferred, with various patterns and colors. For example, the transfer sheet may be applied in various products and shapes such as injection molded articles, extruding molded articles, press molded articles, flat boards, curved plates, and bars, made of materials such as synthetic resin molded products, metal products, wooden products, and ceramic products.

[70]

[71] [Example]

[72] A polyester film (manufactured by Japan Toray Industries, Inc.) with a thickness of

38 micrometer (μm) that an easy binding treatment layer was formed on one side as a base sheet. A release agent (Kunsul Chemical Industrial Co., Ltd., Letron 3100) was coated on the side that the easy binding treatment layer of the base sheet was formed, to form a release layer. A UV curable resin was applied thereon with a microgravure method, dried and then cured with a metal halide lamp of 0.558 J/cnf to form a peeling layer with a thickness of 5 micrometer (μm). The UV curable resin, in which urethane oligomer having a functional group of isocyanate and a hydroxyl acrylate resin were included as major components, was thermally cured to form the peeling layer in a state of semi-cure, and then was completely cured with a UV radiation after molding.

[73] On the peeling layer, TAEGEUK (yin and yang) patterns were partially printed with a gravure printing method to form a print pattern layer in a thickness of 2 micrometer (μm), and dried. Then, to form a glass bead layer, a polyester adhesive was first coated in a thickness of 2 μm on parts that no print pattern was formed, and acrylic resin beads having a diameter of 5 micrometer (μm) were dispersed thereon so that their depth of around 1/2 to 2/3 was embedded, and cured to fix them. Then, the surface of the print pattern layer except for the surface of the glass bead layer to be partially deposited was coated by masking with an aqueous coating agent, and placed in an evaporator to deposit aluminum metal. After depositing, the aqueous coating agent was washed out with a mixture of water/alcohol and dried to remain the metal deposition layer formed on only the surface of the glass bead layer (see Fig. 5). Finally, the transfer sheet of the present invention was prepared by applying a hot-melt adhesive on the print pattern layer and the metal deposition layer formed on the glass bead layer in a thickness of 3 μm to form an adhesive layer.

[74] The transfer sheet prepared according to the present invention was transferred on the outer surface of a synthetic resin water glass with a usual heating under pressure and then observed. As a result, a cubic effect as well as a refined esthetic sense could be observed, since the glass bead layer and the print pattern layer got joined together.

[75] Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

Claims

[I] A transfer sheet having excellent cubic effect, comprising; a base sheet; a release layer and a peeling layer formed sequentially on the base sheet; a glass bead layer formed on the peeling layer; and an adhesive layer formed on the glass bead layer. [2] The transfer sheet having excellent cubic effect according to claim 1, wherein the glass bead layer comprises a resin layer formed on the peeling layer and glass beads partially embedded and fixed in the resin layer. [3] The transfer sheet having excellent cubic effect according to claim 1, further comprising a metal deposition layer formed on the glass bead layer. [4] The transfer sheet having excellent cubic effect according to claim 1, further comprising an easy binding treatment layer formed between the base sheet and the release layer. [5] The transfer sheet having excellent cubic effect according to claim 1, wherein the glass bead layer is partially formed on the peeling layer together with a print pattern layer. [6] The transfer sheet having excellent cubic effect according to claim 5, further comprising a metal deposition layer formed on the glass bead layer and the print pattern layer formed on the peeling layer. [7] The transfer sheet having excellent cubic effect according to claim 5, further comprising a metal deposition layer formed on only the glass bead layer formed partially on the peeling layer. [8] The transfer sheet having excellent cubic effect according to claim 5, further comprising an anchor layer formed between the peeling layer and the print pattern layer or between the print pattern layer and the adhesive layer. [9] The transfer sheet having excellent cubic effect according to claim 5, further comprising an anchor layer formed between the peeling layer and the print pattern layer and between the print pattern layer and the adhesive. [10] The transfer sheet having excellent cubic effect according to any one of claims 1 to 9, wherein the glass beads constituting the glass bead layer are glass marbles or polymer marbles.

[I I] The transfer sheet having excellent cubic effect according to claim 10, wherein the polymer beads are acrylic resin beads. [12] The transfer sheet having excellent cubic effect according to claim 10, wherein the transfer sheet is a concurrent injection mold/transfer sheet.

[13] A method for preparing the transfer sheet having excellent cubic effect as described in any one of claims 1 to 12, comprising the steps of, preparing raw materials including a base sheet; applying a release agent on a surface of the base sheet to form a release layer; applying synthetic resin solution on the release layer to form a peeling layer; forming a glass bead layer on an entire surface of the peeling layer or forming partially a glass bead layer and a print pattern layer on a surface of the peeling layer; and applying an adhesive on the glass bead layer formed on the entire surface of the peeling layer or on the glass bead layer and the print pattern layer formed partially on the peeling layer to form an adhesive layer.

[14] The method for preparing the transfer sheet having excellent cubic effect according to claim 13, wherein the step of forming the glass bead layer comprises the steps of forming a resin layer for fixing glass beads on the peeling layer; and embedding partially glass beads in the resin layer to fix the glass beads in the resin layer.

[15] The method for preparing the transfer sheet having excellent cubic effect according to claim 13 or 14, further comprising the step of forming a metal deposition layer on the glass bead layer or the glass bead layer and the print pattern layer before forming the adhesive layer.