JP2012121178A - Production method for decorative sheet and decorative sheet coating mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet which has an un-cured or semi-cured curable resin layer for forming a hard coat layer and hardly generate an appearance defect even if a thermal cycle test is carried out after laminated on a base body by a post-cure method.SOLUTION: The decorative sheet 1 includes a base material 10, and a curable resin layer 20 which is arranged at one side of the base material 10 and has the curable resin layer 20 having an un-cured or semi-cured curable component where the base material 10 is constituted of an amorphous resin having a glass transition temperature of ≥90°C. In the decorative sheet 1, the amorphous resin having the glass transition temperature of ≥90°C is preferably polyethylene terephthalate having the glass transition temperature of ≥90°C.

Description

  The present invention relates to a decorative sheet that improves the design of a three-dimensional substrate. The present invention also relates to a method for producing a molded body in which a three-dimensional substrate is covered with a decorative sheet.

In joinery, furniture, furniture, etc., a decorative sheet made of a synthetic resin may be bonded to a three-dimensional base to improve the design. As the decorative sheet, a substrate made of a polyvinyl chloride or polyethylene terephthalate substrate with a pattern formed by coloring or printing is used. Moreover, in a decorative sheet, in order to prevent a damage, a hard-coat layer may be provided in the surface of a base material.
Usually, since the hard coat layer is hard, the decorative sheet having the hard coat layer is difficult to perform secondary processing. Therefore, when the decorative sheet is provided with a hard coat layer, an uncured or semi-cured curable resin layer is formed on the surface of the base material to obtain a decorative sheet. A post-cure method is applied in which a molded body in which a decorative sheet is bonded to a substrate is formed by molding the substrate so as to be in close contact with a substrate having a different shape and curing an uncured or semi-cured curable resin layer (for example, Patent Documents). 1).

Japanese Patent Laid-Open No. 2007-7528

Durability is required for products such as joinery, furniture, and furniture obtained by bonding a decorative sheet to a substrate. Durability may be evaluated by a thermal cycle test in which heating and cooling are repeated. However, the molded product obtained by the post-cure method described in Patent Document 1 has wrinkles on the decorative sheet after the thermal cycle test, and the appearance It sometimes caused a defect.
Therefore, the present invention has an uncured or semi-cured curable resin layer for forming a hard coat layer, and hardly causes poor appearance even after a thermal cycle test after being bonded to a substrate by a post-cure method. An object is to provide a decorative sheet. It is another object of the present invention to provide a method for producing a decorative sheet-covered molded article having a hard coat layer and hardly causing poor appearance even when subjected to a cooling and cycling test.

The present invention has the following aspects.
[1] A non-crystalline resin having a base material and a curable resin layer provided on one side of the base material and containing an uncured or semi-cured curable component, the base material having a glass transition temperature of 90 ° C. A decorative sheet comprising:
[2] The decorative sheet according to [1], wherein the amorphous resin having a glass transition temperature of 90 ° C. or higher is polyethylene terephthalate having a glass transition temperature of 90 ° C. or higher.
[3] A method for producing a decorative sheet-covered molded article, wherein the decorative sheet according to [1] or [2] is adhered to a three-dimensional substrate, and the curable resin layer is cured.

The decorative sheet of the present invention has an uncured or semi-cured curable resin layer for forming a hard coat layer, and an appearance defect occurs even after a thermal cycle test after being bonded to a substrate by a post cure method. Hateful.
According to the method for producing a decorative sheet-covered molded article of the present invention, it is possible to easily produce a decorative sheet-coated molded article that has a hard coat layer and hardly causes poor appearance even when subjected to a thermal cycle test.

It is sectional drawing which shows one embodiment of the decorative sheet of this invention.

One embodiment of the decorative sheet of the present invention will be described.
In FIG. 1, sectional drawing of the decorative sheet of this embodiment is shown. The decorative sheet 1 according to the present embodiment includes a first substrate 10, a curable resin layer 20 provided on one surface of the first substrate 10, and the other surface of the first substrate 10. The provided adhesive layer 30 and a decorative layer 40 formed on the opposite side of the adhesive layer 30 from the first substrate 10 are provided.

(First base material)
The first substrate 10 is made of an amorphous resin having a glass transition temperature of 90 ° C. or higher, preferably 100 to 120 ° C. When the amorphous resin has a glass transition temperature of less than 90 ° C., appearance defects are likely to occur when a thermal cycle test is performed after bonding to a substrate by a post-cure method. In the present invention, the glass transition temperature is a value measured by differential thermal analysis (DSC).
Examples of the amorphous resin having a glass transition temperature of 90 ° C. or higher include polyethylene terephthalate, polymethyl methacrylate, polycarbonate, polycycloolefin, and modified polyphenylene ether having a glass transition temperature of 90 ° C. or higher. Among these, polyethylene terephthalate having a glass transition temperature of 90 ° C. or higher is preferable from the viewpoint of moldability and mechanical properties.
Since the visibility of the makeup layer 40 when the makeup layer 40 is viewed through the first substrate 10 is increased, the first substrate 10 is preferably uncolored.

  150-500 micrometers is preferable and, as for the thickness of the 1st base material 10, 350-400 micrometers is more preferable. If the thickness of the first substrate 10 is equal to or greater than the lower limit value, sufficient mechanical strength is obtained, and if the thickness is equal to or less than the upper limit value, sufficient transparency is ensured and the visibility of the decorative layer 40 is improved. Become good.

(Curable resin layer)
The curable resin layer 20 contains an uncured or semi-cured curable component. Here, the “curable component” is a monomer or oligomer that is polymerized and cured by heat or light. “Uncured” means that the curable component is not cured at all, and “semi-cured” means that a part of the curable component is cured and the stretching ratio is 80 ° C. When stretched at 100%, the surface does not crack.

  Examples of the curable component include an acrylic compound, an epoxy compound, and a phenol compound, but an acrylic compound is preferable in that a hard coat layer can be easily formed by curing the curable resin layer 20. Here, the hard coat layer is a layer whose pencil hardness measured in accordance with JIS K5400 is harder than H.

Examples of the acrylic compound include polyfunctional (meth) acrylates having two or more (meth) acryloyl groups in the molecule and monofunctional (meth) acrylates having one (meth) acryloyl group in the molecule.
As polyfunctional (meth) acrylate having two or more (meth) acryloyl groups in the molecule, neopentyl glycol di (meth) acrylate, 1,6-hexanediol diacrylate, (meth) trimethylolpropane tri (meth) ) Polyols such as acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. (Meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, di (meth) acrylate of neopentyl glycol diglycidyl ether, 1,6-hexanediol jig Polyester (meth) acrylate obtained by esterifying epoxy (meth) acrylate such as di (meth) acrylate of sidyl ether, polyhydric alcohol and polyhydric carboxylic acid and / or anhydride thereof and (meth) acrylic acid , Urethane (meth) acrylate obtained by reacting polyhydric alcohol, polyvalent isocyanate and hydroxyl group-containing (meth) acrylate, polysiloxane poly (meth) acrylate, and the like.
Monofunctional (meth) acrylates include hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxy Examples thereof include propyl (meth) acrylate and glycidyl (meth) acrylate.
These may be used individually by 1 type, and may mix and use 2 or more types.

The curable resin layer 20 can be made photopolymerizable by containing a photopolymerization initiator. Examples of the photopolymerization initiator include acetophenones, benzophenones, benzoin ethers, anthraquinones, thiols and the like.
It is preferable that the compounding quantity of a photoinitiator is 0.01-10 mass parts when a sclerosing | hardenable component is 100 mass parts. If the content of the photopolymerization initiator is not less than the lower limit, photopolymerization can be easily performed. However, even if a photopolymerization initiator is blended in excess of the above upper limit, the effect of improving photopolymerization reaches its peak and is useless.

  The thickness of the curable resin layer 20 is preferably 1 to 20 μm, more preferably 3 to 15 μm, and particularly preferably 3 to 5 μm. If the thickness of the curable resin layer 20 is equal to or more than the lower limit value, sufficiently high scratch resistance can be secured after curing, and if it is equal to or less than the upper limit value, occurrence of cracks in the obtained hard coat layer can be prevented.

(Adhesive layer)
The adhesive layer 30 is composed of an adhesive that adheres the first substrate 10 and the decorative layer 40.
As an adhesive, for example, an acrylic hot melt adhesive, an ethylene vinyl acetate hot melt adhesive, a styrene-butadiene rubber solution adhesive, a styrene-butadiene rubber emulsion adhesive, an acrylic solution adhesive, or the like is used. Can do. Among these, an acrylic hot melt adhesive and an ethylene vinyl acetate hot melt adhesive are preferable because a thermal laminate can be applied.
The adhesive layer 30 is also preferably uncolored because the visibility of the decorative layer 40 when the decorative layer 40 is viewed through the adhesive layer 30 is increased.

  The thickness of the adhesive layer 30 is preferably 1 to 50 μm, more preferably 2 to 20 μm, and particularly preferably 3 to 5 μm. If the thickness of the adhesive layer 30 is equal to or greater than the lower limit value, the first substrate 10 and the decorative layer 40 can be bonded with sufficient adhesive strength, and if the thickness is equal to or smaller than the upper limit value, the adhesive layer 30 is easily formed. Can be formed.

(Makeup layer)
The decorative layer 40 includes a second substrate 41 and a printed layer 42 provided on one side of the second substrate 41.
Examples of the resin constituting the second substrate 41 include polyethylene terephthalate and polyvinyl chloride. As long as the second base material 41 is colored, the design of the decorative layer 40 can be further improved, but it may be uncolored.
20-700 micrometers is preferable and, as for the thickness of the 2nd base material 41, 50-500 micrometers is more preferable. If the thickness of the second base material 41 is equal to or greater than the lower limit value, the mechanical strength and concealment can be sufficiently increased, and if the thickness is equal to or less than the upper limit value, sufficient flexibility and printability can be ensured.

The print layer 42 contains a binder resin and a colorant, and a pattern or a pattern is formed by printing. Examples of the pattern and pattern include wood grain, stone grain, cloth grain, grain grain, tiled pattern, brickwork pattern, leather pattern, geometric pattern, character, symbol, full-face solid, metallic and the like. These patterns and patterns can be combined.
Examples of the binder resin include acrylic resin, vinyl chloride-vinyl acetate copolymer, chlorinated polypropylene, polyester resin, cellulose resin, and urethane resin.
Examples of the colorant include inorganic pigments such as titanium white, zinc white, carbon black, iron black, petal, chrome vermillion, cadmium red, ultramarine, cobalt blue, yellow lead, and titanium yellow, phthalocyanine blue, and indanthrene. Examples thereof include organic pigments such as blue, isoindolinone yellow, benzylidine yellow, quinacridone red, polyazo red, berylene red, and aniline black, and pearlescent pigments such as scaly foil powder such as aluminum and brass. The colorants can be used alone or in combination of two or more.

(Production method)
An example of the manufacturing method of the decorative sheet 1 will be described.
In this example, first, the thermosetting resin layer 20 is bonded to one surface of the first base material 10 via the adhesive layer 30, and the decorative layer 40 is bonded to the other surface. Although it does not specifically limit as a bonding method, A thermal lamination is preferable at the point which is simple.
The thermosetting resin layer 20 may be a single layer, but is preferably formed on a sheet-like support from the viewpoint of handleability. As the sheet-like support, for example, a biaxially stretched polyethylene terephthalate film can be used. Moreover, as a formation method of the thermosetting resin layer 20, the method of applying the coating liquid containing an acrylic compound to a sheet-like support body is mentioned. Examples of the coating method include a bar coating method, a roll coating method, a blade coating method, a reverse coating method, a gravure coating method, and a die coating method.
The decorative layer 40 is obtained by printing on one surface of the second base material 41 with an ink containing a colorant and a binder resin to form a printed layer 42. Examples of the printing method at that time include an offset printing method, a gravure printing method, and a screen printing method.

(Decorative sheet covering molding)
By using the decorative sheet 1, a decorative sheet-covered molded article can be produced. That is, in order to obtain a decorative sheet-covered molded article, first, the decorative sheet is molded so that the decorative sheet is in close contact with a three-dimensionally formed base. As a forming method at that time, a vacuum forming method, a press forming method, a pressure forming method, or the like can be applied. The molding temperature is preferably 130 to 180 ° C, more preferably 140 to 170 ° C. If the molding temperature is at least the lower limit, the decorative sheet 1 can be easily molded, and if it is at most the upper limit, the molding cycle can be shortened.
After molding, the curable resin layer 20 is cured by heating or irradiation with active energy rays (ultraviolet rays or electron beams) to form a hard coat layer. Thereby, a decorative sheet-covered molded body in which a three-dimensional substrate is covered with a decorative sheet can be obtained.

(Function and effect)
As described above, the design of the base can be improved by bringing the decorative sheet 1 into close contact with the surface of the three-dimensional base. Further, since the curable resin layer 20 is cured to form a hard coat layer, it has scratch resistance. In addition, the obtained decorative sheet-covered molded body is less likely to wrinkle even when subjected to a thermal cycle test, and poor appearance is unlikely to occur. That is, the decorative sheet-covered molded article is excellent in durability.

(Other embodiment examples)
Note that the present invention is not limited to the above embodiment. For example, the decorative layer 40 may not be provided. However, in that case, in order to impart a decorative property, the first base material 10 is printed or the first base material 10 itself is colored.

Example 1
A post-cure transfer foil was heat-laminated at 170 ° C. from the upper surface of a polyethylene terephthalate film (glass transition temperature: 108 ° C.) having a thickness of 300 μm, which was the first substrate, and from the lower surface.
As the post-cure transfer foil, a 25 μm biaxially stretched PET (“S-25” manufactured by Unitika) and a UV curable resin (urethane acrylate type, “CI-S01” manufactured by Dainichi Seika Co., Ltd.) have a thickness of 4 μm. Then, a curable resin layer was formed, and a sheet on which 4 μm of a heat sealant (polyester, “Dick Seal A-970” manufactured by DIC Graphics) was applied was used.
As the printing sheet, a polyester sheet printed with ink using vinyl chloride-vinyl acetate copolymer as a binder was used.

(Comparative Example 1)
Example 1 except that a 300 μm thick polyethylene terephthalate film (glass transition temperature: 73 ° C.) was used instead of a 300 μm thick polyethylene terephthalate film (glass transition temperature: 108 ° C.) as the first substrate. Thus, a decorative sheet was obtained.

[Evaluation]
Each decorative sheet of the above Examples and Comparative Examples was placed on a MDF substrate having a length of 150 mm and a height of 150 mm, and vacuum-molded at a molding temperature of 165 ° C., so that the decorative sheet was adhered to the substrate. Next, using an ultraviolet irradiation device (Model: ECS-401GX, manufactured by Eye Graphics Co., Ltd.), the curable resin layer is cured by irradiating ultraviolet rays having an intensity of 120 W / cm, thereby forming a hard coat layer. A sheet-coated molded body was obtained.
The obtained decorative sheet-covered molded article was repeated 5 times in a cooling cycle in which it was allowed to stand for 120 minutes in a 70 ° C. environment and for 120 minutes in a −20 ° C. environment.
The appearance of the decorative sheet-covered molded article after the thermal cycle test was evaluated. As a result, when the decorative sheet of Example 1 was used, wrinkles did not occur after the cooling and cycling test, and a good appearance was shown. On the other hand, when the decorative sheet of Comparative Example 1 was used, wrinkles were generated after the cooling and cycling test, and poor appearance was observed.

1 decorative sheet 10 first substrate 20 curable resin layer 30 adhesive layer 40 decorative layer 41 second substrate 42 printing layer

Claims (3)

  A substrate and a curable resin layer provided on one side of the substrate and containing an uncured or semi-cured curable component, and the substrate is composed of an amorphous resin having a glass transition temperature of 90 ° C. or higher. A decorative sheet characterized by   The decorative sheet according to claim 1, wherein the amorphous resin having a glass transition temperature of 90 ° C or higher is polyethylene terephthalate having a glass transition temperature of 90 ° C or higher.   A method for producing a decorative sheet-covered molded article, wherein the decorative sheet according to claim 1 or 2 is brought into close contact with a three-dimensional substrate and the curable resin layer is cured.

Images