JP2011031437A - Method for producing decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a decorative sheet constituted so as to be capable of faithfully reproducing the fine view of target three-dimensional design even in the case that the method is used in an insert molding method. <P>SOLUTION: An uneven shape surface 11 is formed at the rear of a substrate sheet 10 by emboss processing and an UV curable ink layer 12 is formed on the uneven shape surface 11, and after the UV curable ink layer 12 is cured by UV radiation, a design layer 13 is formed on the UV curable ink layer 12. Accordingly, an uneven shape is held as it is even if the substrate sheet 10 is heated at the insert molding and the manufactured decorative sheet 1 can faithfully reproduce the fine view of the target three-dimensional design. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a decorative sheet having a three-dimensional design such as a cloth and used for an interior material of a vehicle.

  Conventionally, as a method for producing this type of decorative sheet, pressing a shaping member formed with positive unevenness of a target three-dimensional design on one side of a sheet material made of a transparent thermoplastic resin, A heating shaping process for forming the irregularities of the irregularities of the shaping member on one side (hereinafter, the process for forming the irregularities of the irregularities of the shaping members is referred to as embossing), and a sheet material A technology comprising: a cooling process for cooling; a coating process for applying an ink or paint containing a glittering material on one side to form a coating film that adheres to the outer surface of the irregularities; and a drying process for drying the coating film. It is disclosed in Patent Document 1. Concavity and convexity formation on a sheet material by embossing has an advantage that complex and relatively large concavities and convexities can be easily formed as compared with the formation of concavities and convexities by cutting.

Japanese Patent No. 4165623

  However, when a decorative molded product that is an integral part of a resin molded product is formed by an insert molding method using a conventional decorative sheet in which irregularities are formed on the sheet material by embossing, the uneven shape formed on the sheet material However, there are cases where the aesthetics of the target three-dimensional design cannot be faithfully reproduced by trying to return to the original plane by the heat of the molding resin.

  An object of this invention is to provide the manufacturing method of the decorating sheet which can reproduce the aesthetics of the target three-dimensional design faithfully even when using for an insert molding method.

  In order to achieve the above object, the present invention has the following features.

The method for producing a decorative sheet of the present invention forms an uneven surface by embossing on the back surface of the base sheet,
Form a UV curable ink layer on the uneven surface,
A pattern layer is formed on the UV curable ink layer after the UV curable ink layer is cured by UV irradiation.

  In the above invention, the UV curable ink layer may be cured by UV irradiation from the back side of the base sheet.

  In the method for producing a decorative molded product of the present invention, the decorative sheet formed by the method for producing a decorative sheet of the above invention is arranged in a mold so that the surface of the base sheet faces the mold cavity. Thereafter, the mold is closed, and a molding resin is poured into the mold to cool and solidify.

  In the method for producing a decorative sheet according to the present invention, an uneven surface is formed on the back surface of a base sheet, a UV curable ink layer 12 is formed on the uneven surface, and the UV curable ink layer 12 is cured by UV irradiation. . Therefore, even if the base sheet is heated during insert molding, the uneven shape is maintained as it is, so that the manufactured decorative sheet can faithfully reproduce the aesthetics of the target three-dimensional design.

  In the method for producing a decorative sheet of the present invention, the UV curable ink layer 12 is cured by UV irradiation from the back side of the base sheet. Therefore, since the UV curable ink layer 12 is reliably cured and the uneven shape is maintained as it is even when the base sheet is heated during the insert molding, the manufactured decorative sheet has a target three-dimensional design. Faithfulness can be faithfully reproduced.

It is sectional drawing which shows the manufacturing method of the decorating sheet of this invention. It is sectional drawing which shows the unevenness | corrugation formation apparatus provided with the pinching roller which can be used for the manufacturing method of the decorating sheet of this invention. It is sectional drawing which shows the hot press machine for uneven | corrugated formation which can be used for the manufacturing method of the decorating sheet of this invention. It is sectional drawing which shows the manufacturing method of the decorative molded product of this invention. It is sectional drawing which shows the decorative molded product formed by the manufacturing method of the decorative molded product of this invention.

  Embodiments of the present invention will be described in detail with reference to the drawings.

  In the manufacturing method of the decorative sheet 1 of the present invention, after forming a negative uneven surface 11 having a target three-dimensional design by embossing on the back surface of the base sheet 10 (see FIG. 1A), the uneven shape is formed. After the UV curable ink layer 12 is formed on the surface 11 and then the UV curable ink layer 12 is cured by UV irradiation (see FIG. 1B), the pattern layer 13 is formed on the UV curable ink layer 12. It is to be formed (see FIG. 1C).

  Examples of the material of the base sheet 10 include acrylic resin, polycarbonate resin (PC resin), acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polystyrene resin, polyurethane resin, nylon resin, and ethylene vinyl alcohol resin. The thickness of the base sheet 10 is preferably in the range of 20 to 500 μm. If the thickness is less than 20 μm, there is a problem that the function of protecting the UV curable ink layer 12 and the pattern layer 13 is lowered. On the other hand, if the thickness exceeds 500 μm, a large amount of heat is required for drawing, and the material cost increases.

  In order to form the concavo-convex shape surface 11 on the back surface of the base sheet 10 by embossing, a concavo-convex forming apparatus including a pinching roller 102 can be used (see FIG. 2). This unevenness forming apparatus includes a sandwiching roller 102, a cooling section 103, a coating machine 104, a UV irradiation apparatus 105, and a sheet traveling path between the sheet feeding roll 100 and the sheet take-up roll 101 in order from the upstream side. Is arranged. The sandwiching roller 102 includes a pressing roller 102a and a shaping roller 102b in which positive and concave portions of a target three-dimensional design are formed on the peripheral surface. Then, the sandwiching roller 102 is rotated while being heated, and the base sheet 10 fed from the sheet feeding roll 100 is passed through the sandwiching roller 102. According to this, a negative concavo-convex shape surface 11 of the concavo-convex shape of the peripheral surface of the shaping roller 102 b is formed by pressing the shaping roller 102 b as a shaping member on the back surface of the base sheet 10.

  Next, after naturally cooling the base sheet 10 in the cooling section 103, a UV curable ink is applied to the formation surface of the concavo-convex shape surface 11 of the base sheet 10 by the coating machine 104 to form the UV curable ink layer 12, Next, the base sheet 10 is passed through the UV irradiation device 105, the UV curable ink layer 12 is irradiated with UV to cure the UV curable ink layer 12, and the decorative sheet 1 thus obtained is wound into a sheet winding roll. Take up to 101. The decorative sheet 1 manufactured in this way has the UV curable ink layer 12 cured, and even if the base sheet 10 is heated during the insert molding, the uneven shape is maintained as it is, so that the target three-dimensional design is achieved. Faithfulness can be faithfully reproduced.

  Here, when UV irradiation is performed from the back side of the base sheet, the UV curable ink layer 12 can be reliably cured. Therefore, the decorative sheet 1 manufactured in this way can faithfully reproduce the aesthetics of the target three-dimensional design.

  Note that the UV curable ink layer 12 and the UV irradiation may be formed after the base sheet 10 is cut to a required length at the downstream end of the cooling section 103.

Moreover, in the said embodiment, although the uneven | corrugated shaped surface 11 was formed in the back surface of the base sheet 10 using the pinching roller 102, you may form the uneven | corrugated shaped surface 11 using the hot press machine 110 shown in FIG. In detail, the hot press machine 110 includes a pair of lower and upper mold holders 110a and 110b for heating and cooling by flowing steam or cooling water therein, and the lower mold holder 110a. A state in which a shaping die 110c made of a silicon material having a positive shape unevenness of a target three-dimensional design is placed on the upper surface of the substrate via a surface plate 110d, and the base sheet 10 is set on the shaping die 110c. The upper mold holder 110b is lowered while both mold holders 110a and 110b are heated with steam of about 180 to 190 ° C., and the base is placed between the surface plate 110e attached to the lower surface of the mold holder 110b and the shaping mold 110c. The sheet 10 is clamped at a pressure of ² to 20 kg / cm ² for 3 to 5 minutes to form negative irregularities of the irregularities of the shaping mold 110c on the lower surface of the base sheet 10, and then both mold holders 110a and 110b. Cold After cooling the substrate sheet 10 by flowing water for 3 to 5 minutes, the upper mold holder 110b is raised and the substrate sheet 10 is taken out. Note that the shaping die 110c may be made of an epoxy resin, an etched iron plate, or an electroformed plate made of metal such as Ni, Cu, or Fe. When using an iron plate or an electroformed plate, the temperature of the heating steam is made slightly lower than the above value. The mold holders 110a and 110b can be heated by electric heating.

  By the way, when using the hot press machine 110, it is necessary to attach and detach the base sheet 10 previously cut to a required length to the hot press machine 110 for one sheet, whereas when using the pinching roller 102, sheet feeding is performed. The concavo-convex surface 11 can be formed continuously on the long base sheet 10 fed out from the roll 100, and the productivity can be improved. On the other hand, when the decorative sheet 1 is a small item, the shaping die 110c can be produced in a shorter period of time and at a lower cost than the shaping roller 102b. Manufacturing at the level is advantageous in that the manufacturing efficiency is high and the cooling process can be performed using the hot press machine 110, so that no space is required. Further, since the shaping mold 110c is formed with positive irregularities on the flat plate, it is easy to clearly form the negative irregular surface 11 on the base sheet 10, and the quality is improved.

  The resin used as the UV curable ink layer 12 contains a prepolymer having a reactive double bond or a reactive epoxy group and a reactive diluent. Examples of prepolymers having reactive double bonds include unsaturated polyesters, alkyd acrylates, polyester acrylates, urethane acrylates, silicon acrylates, diene acrylates, melamine acrylates, and low molecular weight vinyl copolymer functional groups. There are those in which an acryloyl group is introduced by use, or those in which these prepolymers are modified with an isocyanate compound. Examples of the prepolymer having a reactive epoxy group include a reactive epoxy acrylate and a composition obtained by ring-opening polymerization of a reactive epoxy compound using a compound that decomposes by light to generate a Lewis acid as a photopolymerization initiator. is there.

  Reactive diluents include monofunctional monomers such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, tetrafurfryl acrylate, 1-3 butadiol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol Examples thereof include multifunctional monomers such as triacrylate. The reactive diluent is used for the purpose of, for example, adjusting the viscosity of the UV coating ink, crosslinking with the prepolymer, and improving the adhesion with the picture layer 13 to be laminated next.

  If necessary, a photopolymerization initiator is added to the aforementioned prepolymer and reactive diluent. The photopolymerization initiator is used for initiating a polymerization reaction with ultraviolet rays. Examples of such photopolymerization initiators include carbonyl compounds such as acetophenone and benzophenone, sulfur compounds such as etramethyl-thiuram monosulfite and thioxanthone, and azo compounds such as allylazonium salts.

  Further, a colorant is added to the UV curable ink layer 12 in order to make the uneven surface 11 visible from the surface. A pigment or dye of an appropriate color may be added as a colorant, but a glittering material may be added. As the bright material, pearl pigments such as mica and metallic pigments such as aluminum pieces can be used. In this way, when the decorative sheet 1 is viewed with the formation surface of the concavo-convex shape surface 11 as the back surface, the inner surface of the UV curable ink layer 12 in which light incident from the surface adheres to the outer surface of the concavo-convex shape surface 11. The irregular surface 11 is clearly reflected on the surface of the decorative sheet 1, and the aesthetic feeling of the target three-dimensional design is faithfully reproduced.

  The picture layer 13 is a layer having a function of expressing a pattern for decorating a molded product. As a material of the pattern layer 13, a resin such as a polyvinyl resin, a polyamide resin, a polyester resin, an acrylic resin, a polyurethane resin, a polyvinyl acetal resin, a polyester urethane resin, a cellulose ester resin, or an alkyd resin is used as a binder. And a color ink containing an appropriate color pigment or dye as a colorant may be used. As a method for forming the pattern layer 13, a normal printing method such as a gravure printing method, a screen printing method, or an offset printing method may be used. The thickness of the pattern layer 13 is preferably 1 to 30 μm. The pattern layer 13 is not limited to colored ink, and may form a metal vapor deposition layer or the like to express a design with metallic luster. Aluminum, chromium, copper, tin, or the like is used as the material for the metal deposition layer. The metal vapor deposition layer may be formed by using a vacuum vapor deposition method, a sputtering method, an ion plating method, or the like.

  Examples of the material of the adhesive layer 14 formed as necessary include urethane resin, vinyl chloride vinyl acetate copolymer resin, acrylic-ketone resin, acrylic-vinyl resin, and acrylic resin. As a method of forming the adhesive layer 14, for example, there is gravure printing.

  A method of forming the decorative molded product 3 by adhering the decorative sheet 1 formed by the above-described method of manufacturing a decorative sheet to the surface of the resin molded product 2 by an insert molding method will be described.

  Examples of the resin molded product 2 include polyolefin resins such as polyethylene and polypropylene, polystyrene resins, polyvinyl chloride resins, poly (meth) acrylate resins, acrylic resins, polyacetal resins, polyethylene terephthalate, and polybutylene terephthalate. Any known thermoplastic resin such as polyester resin, polyamide resin, polycarbonate resin, polyphenylene sulfide resin, and polyimide resin can be used. These resins can be used alone or in admixture of two or more.

  In order to adhere the decorative sheet 1 to the surface of the resin molded product 2 by the insert molding method, it is performed as follows (see FIG. 4). First, the decorating sheet 1 is placed in a resin molding die 21 composed of a movable die and a fixed die so that the surface of the base sheet 10 faces the die cavity. At that time, the decorative sheet 1 may be fed one by one as a sheet, or a necessary portion may be intermittently fed as a long sheet. In the case of a single sheet, it may be preformed so as to conform to the three-dimensional shape of the mold cavity surface in advance. In the case of a long sheet, it is preferable to use a feeding device having a positioning mechanism so that the registration of the long sheet and the mold 21 coincide. Further, when a long sheet is intermittently fed, the sheet may be fixed by a movable mold and a fixed mold after the position of the sheet is detected by a sensor.

  After the decorative sheet 1 is placed in the mold 21, the mold is closed (see FIG. 4A). Next, the molten molding resin is poured into the mold and solidified by cooling to form a resin molded product 2 (see FIG. 4B). Finally, the mold 21 is opened, and the decorative molded product 3 in which the decorative sheet 1 is bonded to the surface of the resin molded product 2 is taken out (see FIG. 4C). Thus, a decorative molded product 3 is obtained (see FIG. 5).

DESCRIPTION OF SYMBOLS 1 Decorative sheet 2 Resin molded product 3 Decorative molded product 10 Base sheet 11 Uneven shape surface 12 UV curable ink layer 12
DESCRIPTION OF SYMBOLS 13 Picture layer 14 Adhesive layer 21 Mold 100 Sheet delivery roll 101 Sheet winding roll 102 Nipping roller 102a Pressing roller 102b Forming roller 103 Cooling section 104 Coating machine 105 UV irradiation apparatus 110 Heat press machine 110a Type holder 110b Type holder 110c Model 110d Surface plate 110e Surface plate

Claims (3)

Form an uneven surface on the back of the base sheet by embossing,
Form a UV curable ink layer on the uneven surface,
A method for producing a decorative sheet, wherein a pattern layer is formed on a UV curable ink layer after the UV curable ink layer is cured by UV irradiation.   The method for producing a decorative sheet according to claim 1, wherein the UV curable ink layer is cured by UV irradiation from the back side of the base sheet. The decorative sheet formed by the method for producing a decorative sheet according to claim 1 or 2 is placed in a mold so that the surface of the base sheet faces the mold cavity, and then the mold is closed to form a mold. A method for producing a decorative molded product, characterized in that a molding resin is poured into the inside and cooled and solidified.

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