JP2012045781A - Decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet that prevents foil burr or foil fracture, produces a decorated molded article with high production efficiency, and has moldability for obtaining a molded article with satisfactory high hardness, high transferability, and more complex form, and to provide a decorated molded article using the decorative sheet.SOLUTION: The decorative sheet has at least a mold releasing layer and a hard coat forming layer on one side of a base material film. The mold releasing layer is formed of a coating liquid containing an aqueous melamine resin. The peeling strength between the mold releasing layer and the hard coat forming layer at 20°C is 0.06-0.4N/18 mm, the peeling strength at 80°C is 0.06-0.5N/18 mm, in a decorated molded article using the sheet.

Description

  The present invention relates to a decorative sheet.

Conventionally, an injection molding simultaneous decorating method is used for decorating a resin molded body having a complicated surface shape such as a three-dimensional curved surface. In the injection molding simultaneous decoration method, the decorative sheet inserted into the mold at the time of injection molding is integrated with the molten injection resin injected and injected into the cavity to decorate the surface of the resin molded body Generally, it is roughly classified into an injection molding simultaneous laminate decoration method and an injection molding simultaneous transfer decoration method depending on the difference in the configuration of the decorative sheet integrated with the resin molded body.
In the injection molding simultaneous transfer decorating method, the transfer layer side of the decorative sheet for injection molding simultaneous transfer decoration is directed into the mold and heated from the transfer layer side by a hot platen, and the decorative sheet is placed in the mold. Molded along the shape, tightly attached to the inner surface of the mold and clamped, then injected the molten injection resin into the cavity to integrate the decorative sheet and the injection resin, then cooled the decorative molded product And after taking out from a metal mold | die, the decorative molded product which transcribe | transferred the transfer layer by peeling a base film can be obtained.

  The decorative molded products thus obtained include notebooks including mobile PCs that can be carried everyday, for example, along with the expansion of the PC market in recent years, in addition to the fields of household appliances and automobile interiors that have been used in the past. Use in the field of personal computers, automobile exteriors, and cellular phones are also attracting attention. In these fields, the decorative sheet is required to have a formability that can give the decorative molded product surface characteristics such as good high hardness and at the same time obtain a molded product having a complicated shape.

  By the way, in the injection molding simultaneous transfer decoration method, after the decorative molded product is cooled and taken out from the mold, when the base film is peeled off, a recess or a through hole is formed on the end or surface of the object to be decorated. If this occurs, the transfer layer will remain even if you do not want to decorate these areas, so that when the so-called foil flash or decorative sheet is slit, a part of the transfer layer near the slit is added. The so-called foil spillage that peels off and falls off the decorative sheet may occur. When foil burr occurs, it takes time and effort to remove the foil, and the work efficiency deteriorates.In addition, the portion to be transferred is peeled off during the removal operation, resulting in poor appearance of the decorative molded product. It becomes a cause. Further, when foil spillage occurs, a part of the transfer layer that has fallen off adheres to the surface of the transfer layer or the decorative sheet, which may cause transfer failure or poor appearance of the decorative molded product. Furthermore, when the dropped transfer layer is sandwiched between the decorative sheet and the mold, it causes a molding defect in which a dent is generated on the surface of the part of the decorative molded product through the decorative sheet. was there.

  Therefore, it is a problem to prevent the phenomenon such as foil spill and foil spillage. For example, as a method for preventing foil spillage, there is a method of removing a slit portion on a base sheet and providing a release layer (see, for example, Patent Document 1). Although this method eliminates the problem of foil spillage, it may be necessary to produce a separate release layer for each molded product, which may reduce work efficiency. Moreover, the decoration sheet | seat which has various structures is examined as a response | compatibility to foil flash and foil spill (for example, patent documents 2-6). However, in the ones disclosed in Patent Documents 2 and 3, since it is necessary to additionally provide a foil spill prevention layer, this leads to an increase in the printing process and the manufacturing process, resulting in a decrease in manufacturing efficiency and an increase in cost. End up. Since it is necessary to provide each layer which comprises a transfer layer on a stripe, what is disclosed by patent document 4 is difficult to thicken the outermost surface layer of a decorative molded product in order to provide high hardness. Also, the one disclosed in Patent Document 5 has a problem in terms of physical properties such as high hardness of the transfer layer because it is difficult to increase the thickness of the outermost surface layer of the decorative molded product. In addition, in the one disclosed in Patent Document 6, since a release layer is formed by printing coating except for the slit portion using a pre-adhesive equipment sheet, manufacturing efficiency deteriorates and costs increase. It becomes a factor of.

Japanese Patent No. 3953867 Japanese Utility Model Publication No. 6-65258 Japanese Utility Model Publication No. 6-65259 Japanese Utility Model Publication No. 4-45799 JP-A-6-183124 Japanese Patent Laid-Open No. 11-58584

  Under such circumstances, the present invention suppresses the occurrence of foil flashing and foil spillage, makes it possible to produce a decorative molded product with excellent production efficiency, and has good high hardness and excellent transferability. It is another object of the present invention to provide a decorative sheet that imparts a moldability capable of obtaining a molded product having a more complicated shape, and a decorative molded product using the decorative sheet.

  As a result of intensive studies to achieve the above problems, the present inventor has found that the problems can be solved by the following invention. That is, the present invention provides the following decorative sheet, a method for manufacturing a decorative molded product using the same, and a decorative molded product obtained by the manufacturing method.

1. A decorative sheet having at least a release layer and a hard coat layer forming layer in order on one side of a base film, wherein the release layer is formed of a coating liquid containing a hydrophilic resin, and the release layer The decorative sheet having a peel strength at 20 ° C. of 0.06 to 0.4 N / 18 mm and a peel strength at 80 ° C. of 0.06 to 0.5 N / 18 mm.
2. The manufacturing method of the decorative molded product which has the following process (1) -process (5).
Step (1) Disposing the decorative sheet described in 1 above in the injection mold (2) Injecting molten resin into the cavity, cooling and solidifying the resin molded body and the decorative sheet (3) Process step for removing the molded body in which the resin molded body and the decorative sheet are integrated from the mold (4) Process step for peeling the base film of the decorative sheet from the molded body ( 5) Hard coat layer forming step of curing the hard coat layer forming layer provided on the molded body. A decorative molded product obtained by the production method described in 2 above.

  According to the present invention, it is possible to suppress the occurrence of foil flashing and foil spillage, to produce a decorative molded product with excellent production efficiency, and to have good high hardness, excellent transferability and more complicated shape. It is possible to provide a decorative sheet imparting moldability to obtain a simple molded product, and a decorative molded product using the decorative sheet.

It is a schematic diagram which shows the cross section of the decorating sheet of this invention. It is a schematic diagram which shows the cross section of the decorative molded product of this invention.

[Decorative sheet]
The decorative sheet of the present invention is a decorative sheet having at least a release layer and a hard coat layer forming layer in order on one side of a base film, and the release layer is formed of a coating liquid containing a hydrophilic resin. The peel strength at 20 ° C. between the release layer and the hard coat layer forming layer is 0.06 to 0.4 N / 18 mm, and the peel strength at 80 ° C. is 0.06 to 0.5 N / 18 mm. It is. Hereinafter, the decorative sheet of the present invention will be described with reference to FIGS. 1 and 2. Drawing 1 is a mimetic diagram showing the section about the desirable one mode of the decorating sheet of the present invention. FIG. 2 is a schematic diagram showing a cross section of a preferred embodiment of the decorative molded product of the present invention.
The decorative sheet 10 of the present invention shown in FIG. 1 has a release layer 12, a hard coat layer forming layer 13, an anchor layer 14, a picture layer 15 and an adhesive layer on one surface of a base film 11 made of a polyester film. 16 is laminated in order, and the antistatic layer 19 is laminated on the other surface of the base film 11 (the surface opposite to the surface on which the release layer 11 is provided). Further, the decorative molded product 20 of the present invention shown in FIG. 2 is a hard coat formed by curing the adhesive layer 16, the pattern layer 15, the anchor layer 14, and the hard coat layer forming layer 13 on the surface of the resin molded body 21. The layers 22 are sequentially stacked.

<Base film>
Examples of the base film 11 include polyolefin resins such as polyethylene and polypropylene; vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene / vinyl acetate copolymer, and ethylene / vinyl alcohol copolymer; polyethylene terephthalate. Polyester resins such as polybutylene terephthalate; Acrylic resins such as poly (meth) acrylate methyl and poly (meth) ethyl acrylate; Styrene resins such as polystyrene, Acrylonitrile butadiene styrene copolymers, Cellulose triacetate Those made of an elastomeric resin such as cellophane, polycarbonate, and polyurethane are used. Of these, polyester resins, particularly polyethylene terephthalate (hereinafter referred to as “PET”) are preferred from the viewpoint of good moldability and peelability.
The thickness of the base film 11 is preferably in the range of 25 to 150 μm, and more preferably in the range of 50 to 100 μm, from the viewpoints of moldability, shape followability, and easy handling.

<Release layer 12>
The release layer 12 preferably has a transfer layer 17 formed by laminating a hard coat layer forming layer 13, an anchor layer 14, a pattern layer 15, and an adhesive layer 16 in order so that the release layer 12 can be easily peeled off from the substrate sheet 11. It is a layer provided, and is a layer provided on the entire surface including the slit portion. By having the release layer 12, the transfer layer 17 is reliably and easily transferred from the decorative sheet of the present invention to the transfer target, and is provided with the base film 11, the release layer 12, and if necessary. The release layer 18 composed of the antistatic layer 19 can be reliably peeled off.

  The release layer 12 is preferably formed of a hydrophilic resin from the viewpoint of suppressing the occurrence of foil flash and foil spillage. The hydrophilic resin is preferably a water-soluble or water-dispersible hydrophilic resin having a hydroxyl group, carboxyl group, amide group, amino group, sulfonic acid group and / or ether group in the molecule. For example, water-based melamine resin, water-based polyester resin, water-based polyester urethane resin, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polystyrene sulfonic acid, polyacrylamide, carboxymethyl cellulose, chitosan, polyethylene oxide, water-soluble nylon, Preferred are copolymers of monomers that form coalesces, acrylic polymers having a polyoxyethylene chain such as 2-methoxypolyethylene glycol methacrylate / 2-hydroxylethyl acrylate copolymer, and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types. In the present invention, a water-based melamine resin and a water-based polyester resin are preferable from the viewpoint of obtaining good releasability (peeling strength) by combining with a hard coat layer forming layer described later, and a uniform coating on a base film From the viewpoint of improving the leveling ability, it is particularly preferable to use these in combination. When the water-based melamine resin and the water-based polyester resin are used in combination, the blending ratio (mass ratio) is 2/1 to 50/1 from the viewpoint of improving the leveling property that can be applied uniformly on the base film. 5/1 to 15/1 is more preferable.

When a water-based polyester resin is used as the hydrophilic resin, the number average molecular weight Mn of the polyester resin is preferably 5,000 to 50,000, more preferably 5,000 to 30,000, and further preferably 5,000 to 10,000. When the number average molecular weight is within the above range, good peel strength can be obtained. In addition, the said number average molecular weight Mn is the value of standard polystyrene conversion by the gel permeation chromatography method (GPC method).
The glass transition temperature (Tg) of the water-based polyester resin is preferably −25 to 90 ° C., more preferably 0 to 90 ° C., and further preferably 60 to 80 ° C. When the glass transition temperature is within the above range, good peel strength can be obtained. Here, the glass transition temperature (Tg) is a value measured by using a DSC apparatus under a temperature increase rate of 8 ° C./min.
Moreover, in the said polyester polyol-type resin, it is preferable that the weight average molecular weight Mw is 25000 or more from a viewpoint of adhesive performance. Furthermore, the hydroxyl value is preferably 1 to 25 mgKOH / g, more preferably 3 to 20 mgKOH / g, and the acid value is preferably 5 mgKOH / g or less, more preferably 3 mgKOH / g or less. When the hydroxyl value and acid value are within the above ranges, good peel strength can be obtained.

  The hydrophilic resin is preferably used as an aqueous dispersion as its usage form. When used as an aqueous dispersion, it can be used in the form of a dispersion or emulsion dispersed in water, and preferably in a dispersion state with a smaller particle size. The average particle size of the hydrophilic resin in the aqueous dispersion is preferably about 0.001 to 0.1 μm, and more preferably 0.001 to 0.05 μm.

  In the case of using an aqueous melamine resin, it is preferable to use an acid catalyst in order to accelerate the curing of the resin. The acid catalyst is not particularly limited, and preferable examples include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, and dinonylnaphthalenedisulfonic acid. This acid catalyst reacts not only with water-based melamine resins, but also with water-based polyester resins and water-based polyester urethane resins, and may cause gelation, so when using water-based melamine resins and water-based polyester resins or water-based polyester urethane resins in combination. It is preferable to add an acid catalyst after mixing these resins. From the viewpoint of preventing gelation, an aqueous polyester resin or an aqueous polyester urethane resin may be mixed after an acid catalyst is added to the aqueous melamine resin and mixed.

  In order to improve the releasability of the release layer 12, a known release agent such as wax may be used in addition to the fluororesin release agent and the silicone resin release agent. In addition, inorganic particles such as silica (colloidal silica, fumed silica, precipitated silica, etc.), alumina, zirconia, titania, zinc oxide, etc. are added in a range of 5 to 40% by mass, and a release layer having a matte feeling is obtained. It can also be formed. Further, for example, the release layer 12 may be formed using an ink mainly composed of a vinyl resin such as an acrylic resin or a cellulose resin with the above hydrophilic resin or release agent added thereto. .

The release layer 12 is formed by using an ink prepared by dissolving or dispersing the above-mentioned hydrophilic resin and the like in an appropriate solvent on the base sheet 11 by a known means. It can be applied and dried, and the thickness is preferably about 0.01 to 5 μm, more preferably 0.1 to 2 μm.
As a coating method in forming the release layer 12, a wire bar coating method, a doctor blade method, a micro gravure coating method, a gravure roll coating method, a reverse roll coating method, an air knife coating method, a rod coating method, a die coating method, a kiss coating method, A reverse kiss coating method, an impregnation method, a curtain coating method, a spray coating method, a dip coating method or the like can be applied alone or in combination.

<< Hard Coat Layer Forming Layer 13 >>
The hard coat layer forming layer 13 is a layer that forms the hard coat layer 22 in the decorative molded product 20 by curing. The hard coat layer 22 is an outermost layer of the decorative molded product and is a layer for protecting the molded product and the pattern layer from abrasion, light, chemicals, and the like. Therefore, the hard coat layer forming layer 13 is a layer having the performance of being excellent in surface physical properties such as chemical resistance and contamination resistance as well as excellent high hardness and scratch resistance by being cured. Cost.

As the resin used for the hard coat layer forming layer 13, a resin having physical properties capable of performing other functions required according to the application may be appropriately selected in consideration of the above performance. Examples of such resins include curable resins such as thermoplastic resins, thermosetting resins, and ionizing radiation curable resins.
As the thermoplastic resin, an acrylic resin, a cellulose resin, a thermoplastic urethane resin, or a vinyl polymer such as vinyl acetate resin can be used. As the thermosetting resin, a melamine resin, a two-component curable urethane resin, an epoxy resin, or the like can be used. Further, as the ionizing radiation curable resin, an ionizing radiation curable resin such as an acrylate type or an epoxy type can be used.
When more excellent performance is required for the hard coat layer, it is preferable to use a curable resin rather than a thermoplastic resin, and further use an ionizing radiation curable resin in the curable resin. Of these various resins, curable resins such as thermosetting resins and ionizing radiation curable resins are conventionally known to be susceptible to foil spillage, but the present invention aims to prevent such spillage. This is preferable in the present invention in terms of the effect of being able to.

(Ionizing radiation curable resin)
The ionizing radiation curable resin used for forming the hard coat layer forming layer 13 is a resin composition that can be cured by ionizing radiation such as ultraviolet rays and electron beams, and specifically, a radical polymerizable unsaturated bond in the molecule. Alternatively, a resin composition in which prepolymers (including so-called oligomers) and / or monomers having a cationic polymerizable functional group are appropriately mixed is preferably used. These prepolymers or monomers are used alone or in combination.

  Specifically, the prepolymer or monomer is a compound having a radically polymerizable unsaturated group such as a (meth) acryloyl group or (meth) acryloyloxy group, a cationically polymerizable functional group such as an epoxy group in the molecule. Become. Further, a polyene / thiol prepolymer based on a combination of polyene and polythiol is also used.

Examples of prepolymers having radically polymerizable unsaturated groups include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, and silicone (meth) acrylate. Etc. can be used. The molecular weight is usually about 250 to 100,000.
Also, (meth) acrylic acid alkyl ester and functional group-containing (meth) acrylic copolymerizable with glycidyl (meth) acrylate, (meth) acrylamide, (meth) acrylonitrile, hydroxyalkyl (meth) acrylate, etc. Acrylic (meth) acrylate prepolymers obtained by copolymerization with carboxylic acids such as methacrylic compounds or (meth) acrylic acid, maleic acid, fumaric acid and itaconic acid are also cited as prepolymers having radically polymerizable unsaturated groups. It is done.

  Examples of the monomer having a radically polymerizable unsaturated group include, as monofunctional monomers, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate, and the like. In addition, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate as polyfunctional monomers Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

Examples of the prepolymer having a cationic polymerizable functional group include a prepolymer of an epoxy resin such as a bisphenol type epoxy resin or a novolac type epoxy compound, or a vinyl ether resin such as a fatty acid vinyl ether or an aromatic vinyl ether.
Examples of the polythiol include polythiols such as trimethylolpropane trithioglycolate and pentaerythritol tetrathioglycolate. Moreover, as said polyene, what added allyl alcohol to the both ends of the polyurethane by a diol and diisocyanate etc. are mentioned.

  In the case of curing with ultraviolet rays or visible rays, a photopolymerization initiator is further added to the ionizing radiation curable resin. In the case of a resin system having a radically polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, and benzoin methyl ethers can be used alone or in combination as a photopolymerization initiator. In the case of a resin system having a cationic polymerizable functional group, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metallocene compound, a benzoin sulfonic acid ester or the like is used alone or as a mixture as a photopolymerization initiator. be able to. In addition, as addition amount of these photoinitiators, it is about 0.1-10 mass parts with respect to 100 mass parts of ionizing radiation curable resin.

(Resin composition)
In the present invention, the hard coat layer forming layer 13 is usually formed of a resin composition containing the thermoplastic resin, a resin such as a thermosetting resin and an ionizing radiation curable resin, and other additives.
Moreover, when ionizing radiation curable resin is employ | adopted as resin, a silicone is also mentioned preferably as an additive. Examples of silicones include silicone oil and reactive silicones. Some reactive silicones react with and bind to ionizing radiation curable resins when cured with ionizing radiation, and some remain. Examples of the reactive silicone include reactive silicone modified by acrylic modification, methacryl modification, epoxy modification, or the like. The proportion on the basis of mass containing silicone is about 0.1 to 10 parts by mass, preferably 0.3 to 5 parts by mass with respect to 100 parts by mass of the ionizing radiation curable resin composition. Below this range, the surface tends to be contaminated, and beyond this range, the adhesion of the adhesive layer to the anchor layer will be low.

A filler is also preferably added to the resin composition. Examples of the filler include micro silica and polyethylene wax. Examples of the polyethylene wax include polyethylene resin particles and beads, and spherical beads are preferable. However, since addition of polyethylene wax reduces the breakage of the foil, the addition amount is preferably about 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the resin. is there.
In addition, in the resin composition, inorganic particles such as silica (colloidal silica, fumed silica, precipitated silica, etc.), alumina, zirconia, titania, zinc oxide, etc., and vinyl groups, (meth) acryloyl groups, Reactive inorganic particles having an ethylenically unsaturated bond such as an allyl group and a reactive functional group such as an epoxy group or a silanol group are also preferably added. From the viewpoint of obtaining high hardness, addition of reactive inorganic particles is preferable.

<Other additives>
In the resin composition, if necessary, a thermoplastic resin such as an acrylic resin, a vinyl acetate resin, and a cellulose resin, a polyfunctional isocyanate compound, an ultraviolet absorber, an infrared absorber, a light stabilizer, and a polymerization prohibition. Other known additives such as additives, crosslinking agents, antistatic agents, antioxidants, leveling agents, thixotropic agents, coupling agents, plasticizers, antifoaming agents, fillers, thermal radical generators, aluminum chelating agents, etc. An agent can also be added.

<Formation of hard coat layer forming layer 13>
The hard coat layer forming layer 13 is formed by applying the resin composition used in the present invention by a gravure coating method, a roll coating method, a comma coating method, a die coating method or the like, a gravure printing method, a screen printing method, or the like. Can be formed.
The thickness of the hard coat layer forming layer 13 is preferably in the range of 0.1 to 20 μm, more preferably 1 to 10 μm. When the thickness is in the above range, not only excellent high hardness and scratch resistance, but also surface properties such as chemical resistance and stain resistance are obtained, and at the same time, excellent moldability and shape followability are obtained. Obtainable. It is also advantageous in terms of material costs.

<< Peeling strength between release layer 12 and hard coat layer forming layer 13 >>
The decorative sheet of the present invention has a peel strength at 20 ° C. between the release layer 12 and the hard coat layer forming layer 13 of 0.06 to 0.4 N / 18 mm, and a peel strength at 80 ° C. of 0.06 to 0. .5N / 18mm.
If the peel strength at 20 ° C. and 80 ° C. is less than the lower limit of 0.06 N / 18 mm, the peel strength is too small and foil flashing and spillage occur. Deteriorates, and the appearance of the decorative molded product is poor. On the other hand, if the peel strength at 20 ° C. and 80 ° C. is larger than the upper limit of 0.4 or 0.5 N / 18 mm, the peel strength is too high, leading to a poor appearance of the decorative molded product due to transfer failure. From such a viewpoint, the peel strength at 20 ° C. between the release layer 12 and the hard coat layer forming layer 13 is preferably 0.1 to 0.3 N / 18 mm, and more preferably 0.14 to 0.25 N / 18 mm. . The peel strength at 80 ° C. is preferably 0.07 to 0.5 N / 18 mm, more preferably 0.07 to 0.4 N / 18 mm.

  In addition, the decorative sheet of the present invention has a feature that a change in peel strength with time is small. More specifically, the decorative sheet of the present invention is characterized in that the peel strength is less likely to decrease from the value immediately after production without being affected by the environment in which the decorative sheet is left for 120 hours after production. Have. This feature is prominent when the release layer is formed of a hydrophilic resin, particularly when a water-based melamine resin and a water-based polyester urethane resin are used in combination as the hydrophilic resin.

  The peel strength in the present invention is a value measured as follows. First, a double-sided tape having a width of 50 mm and a length of 150 mm is opposite to the surface on which the release layer of the base film of the decorative sheet having the same size as the tape is provided (when an antistatic layer is provided) Was attached to the surface of the antistatic layer and fixed to a flat table. Next, cellophane tape having a width of 18 mm and a length of 100 mm (cellophane adhesive tape manufactured by Nichiban Co., Ltd., “cello tape (registered trademark))) is closely attached to the surface of the transfer layer 17 of the fixed decorative sheet. Cut along the tape with a cutter. Next, the transfer layer 17 was peeled off from the release layer 18 together with the adhesive tape (registered trademark), and the transfer layer 17 was lifted about 10 mm, and a hook jig was attached to the tip. After leaving for 3 minutes at a predetermined temperature (20 ° C. or 80 ° C.), a hook of a tension gauge (for load measurement) is hooked on the hooking jig, and the tension gauge is peeled off from the transfer layer 17 and the release layer 18. The peel rate was slowly raised in the range of 100 to 500 mm / second so that the angle was always 90 °, and the load indicated by the tension gauge was taken as the peel strength (N / 18 mm).

  When the tension gauge is pulled up as described above, the load indicated by the tension gauge fluctuates, so that the obtained peel strength has a value having a certain fluctuation width. In the present invention, the entire range of the runout width needs to be included in the range of peel strength defined in the present invention. That is, the decorative sheet in which the entire range of the runout width is included in the range of the peel strength defined in the present invention corresponds to the decorative sheet of the present invention. On the other hand, when even a part of the range of the swing width falls outside the range of the peel strength defined in the present invention, the decorative sheet having such a peel strength is not included in the decorative sheet of the present invention.

  In the present invention, the peel strength between the release layer 12 and the hard coat layer forming layer 13 can be adjusted by increasing or decreasing the amount of the polyester resin. Further, it is adjusted by the material for forming the release layer 12, for example, the kind of hydrophilic resin, the fluororesin mold release agent, the silicone resin mold release agent, the mold release agent such as wax, or the inorganic particles added to the release resin 12 can do. For example, when inorganic particles are used for forming the release layer 12, the release layer 12 has a matte feeling, and therefore, the design can have a matte feeling with the hard coat layer settled.

<< Anchor layer 14 >>
The anchor layer 14 is a layer provided as desired in order to improve the adhesion between the hard coat layer forming layer 13 and the adhesive layer 16 or the pattern layer 15 when there is the pattern layer 15.
The anchor layer 14 is a two-component curable urethane resin, a thermosetting urethane resin, a melamine resin, a cellulose ester resin, a chlorine-containing rubber resin, a chlorine-containing vinyl resin, an acrylic resin, an epoxy resin, and a vinyl copolymer. For example, a coating resin such as a gravure coating method, a roll coating method, or a comma coating method, a gravure printing method, a screen printing method, or the like is applied on the hard coat layer forming layer 13 formed as described above using a coalesced resin. Can be formed.
The thickness of the anchor layer 14 is usually about 0.1 to 5 μm, preferably about 1 to 5 μm.

<< Pattern layer 15 >>
The pattern layer 15 is a layer for imparting a desired design to the decorative molded product, and is a layer provided as desired. Although the pattern of the pattern layer 15 is arbitrary, for example, a pattern composed of wood grain, stone pattern, cloth pattern, sand pattern, geometric pattern, character, and the like can be mentioned. In addition, the pattern layer 15 can be provided with a pattern pattern layer expressing the above pattern and a whole surface solid layer alone or in combination, and the whole surface solid layer is usually used as a concealing layer, a colored layer, a colored concealing layer, or the like. .

The pattern layer 15 is usually a polyvinyl resin, a polyester resin, an acrylic resin, a polyvinyl acetal resin, a cellulosic resin on the hard coat layer forming layer 13 or the anchor layer 14 formed as described above. It is formed by printing with a printing ink containing a resin such as a resin as a binder and a pigment or dye of an appropriate color as a colorant. Examples of the printing method include known printing methods such as gravure printing, offset printing, silk screen printing, transfer printing from a transfer sheet, sublimation transfer printing, and ink jet printing.
The thickness of the pattern layer 15 is preferably 5 to 40 μm and more preferably 5 to 30 μm from the viewpoint of design.

<< Adhesive layer 16 >>
The adhesive layer 16 is a layer formed to transfer the transfer layer 17 to the resin molded body with good adhesiveness. For the adhesive layer 16, a heat-sensitive or pressure-sensitive resin suitable for the material of the resin molded body is appropriately used. For example, when the material of the resin molding is an acrylic resin, it is preferable to use an acrylic resin. If the resin molding is made of polyphenylene oxide / polystyrene resin, polycarbonate resin, or styrene resin, use an acrylic resin, polystyrene resin, polyamide resin, or the like that has an affinity for these resins. Is preferred. Furthermore, when the material of the resin molding is a polypropylene resin, it is preferable to use a chlorinated polyolefin resin, a chlorinated ethylene-vinyl acetate copolymer resin, a cyclized rubber, or a coumarone indene resin.

Examples of the method for forming the adhesive layer 16 include a coating method such as a gravure coating method and a roll coating method, a printing method such as a gravure printing method and a screen printing method. In addition, when the pattern layer 15 has sufficient adhesiveness with respect to a resin molding, the contact bonding layer 16 does not need to be provided.
As for the thickness of the contact bonding layer 16, about 0.1-5 micrometers is preferable normally.

<Antistatic layer 19>
The decorative sheet of the present invention can be provided with an antistatic layer 19. The antistatic layer 19 is a layer that is preferably provided in order to prevent foreign matter from adhering to the decorative sheet, and is provided on the surface of the base film 11 opposite to the surface on which the release layer is provided.
Antistatic agents used for the antistatic layer include anionic surfactants such as carboxylic acid, sulfonic acid, and phosphoric acid; cationic surfactants such as quaternary ammonium; alkylbetaine, alkylimidazoline , Amphoteric surfactants such as alkylalanine; nonionic surfactants such as alkylene oxide polymers, alkylene oxide copolymers, aliphatic alcohol-alkylene oxide adducts; carbon, gold, platinum, silver, copper, Inorganic conductive materials such as various metal powders such as aluminum, nickel, titanium and molybdenum; polyacetylene, polypyrrole, polyparaphenylene, polyaniline, polythiophene, polyphenylene vinylene, polyvinyl carbazole, or aminocarboxylic acid, dicarboxylic acid and polyethylene glycol A conductive polymer such as polyether ester amide resin consisting Lumpur are preferably exemplified.

  The antistatic layer is formed by applying a coating material composed of the above-described antistatic agent and an organic solvent by a coating method such as a gravure coating method or a roll coating method, or a printing method such as a gravure printing method or a screen printing method. The thickness of the antistatic layer formed in this manner is usually preferably 0.1 to 5 μm. If the thickness of the antistatic layer is within the above range, excellent antistatic performance can be obtained efficiently.

《Use of decorative sheet, etc.》
The decorative sheet of the present invention can suppress the occurrence of foil flashing and foil spillage, or because the hard coat layer forming layer is tack-free only by heat drying if necessary, it has excellent blocking resistance and at the same time heat resistance Since it can also give the property, it is excellent in production efficiency. Moreover, since it is not necessary to perform a semi-curing treatment by irradiation with ionizing radiation or high-temperature baking in order to make it tack-free, it has excellent moldability and shape followability. Furthermore, by curing the hard coat layer forming layer using ionizing radiation after molding transfer, excellent high hardness and scratch resistance can be obtained. For these reasons, it can be used in a wide range of fields such as household electrical appliances and automobile interior parts, personal computer fields, especially personal computer housings.

[Method of manufacturing decorative molded product]
The method for producing a decorative molded product according to the present invention includes a step (1) a step of arranging the decorative sheet of the present invention in an injection mold; a step (2) injecting a molten resin into the cavity, and cooling and solidifying. Then, an injection step of laminating and integrating the resin molded body and the decorative sheet; step (3) a step of taking out the molded body integrated with the resin molded body and the decorative sheet from the mold; step (4) from the molded body A step of peeling the base film of the decorative sheet; and a step (5) a hard coat layer forming step of curing the ionizing radiation on the hard coat layer forming layer provided on the molded body.

<< Process (1) >>
Step (1) is a step of placing and decorating the decorative sheet of the present invention in a molding die. Specifically, the decorative sheet is placed in a molding die composed of a movable mold and a fixed mold with the transfer layer 17 inside, that is, the base film 11 is on the fixed mold side. Send it in. At this time, a single sheet of decorative sheet may be fed one by one, or a necessary part of a long decorative sheet may be intermittently fed.

  When placing the decorative sheet in the molding die, (i) simply heat the die and place it so as to adhere to the die by vacuum suction, or (ii) place a heating plate from the transfer layer 17 side. It can be heated and softened, preliminarily molded so that the decorative sheet follows the shape in the mold, and clamped so as to be in close contact with the inner surface of the mold. The heating temperature at (ii) is preferably in the range of near the glass transition temperature of the substrate film 11 and less than the melting temperature (or melting point), and is usually performed at a temperature near the glass transition temperature. In addition, said glass transition temperature vicinity is the range of about glass transition temperature +/- 5 degreeC, and is generally about 70-130 degreeC. In the case of (ii), vacuuming can also be performed when the decorative sheet is heated and softened with a hot plate for the purpose of bringing the decorative sheet into close contact with the surface of the molding die.

<< Step (2) >>
Step (2) is an injection step in which molten resin is injected into the cavity, cooled and solidified, and the resin molded body and the decorative sheet are laminated and integrated. When the injection resin is a thermoplastic resin, it is made into a fluid state by heating and melting. When the injection resin is a thermosetting resin, the uncured liquid composition is appropriately heated and injected in a fluid state, and then cooled. And solidify. As a result, the decorative sheet is integrally attached to the formed resin molded body, and becomes a decorative molded product. The heating temperature of the injection resin is generally about 180 to 280 ° C. although it depends on the injection resin.

(Injection resin)
The injection resin used for the decorative molded product may be any thermoplastic resin that can be injection-molded or a thermosetting resin (including a two-component curable resin), and various resins can be used. Examples of such thermoplastic resin materials include polystyrene resins, polyolefin resins, ABS resins (including heat-resistant ABS resins), AS resins, AN resins, polyphenylene oxide resins, polycarbonate resins, polyacetal resins, and acrylic resins. Examples thereof include resins, polyethylene terephthalate resins, polybutylene terephthalate resins, polysulfone resins, and polyphenylene sulfide resins. Examples of the thermosetting resin include a two-component reaction curable polyurethane resin and an epoxy resin. These resins may be used alone or in combination of two or more.

<< Step (3) and Step (4) >>
Step (3) is a step of removing from the mold a molded body in which the decorative sheet and the resin molded body are integrated, and step (4) is a step of peeling the base film of the decorative sheet from the molded body. It is. Since the base film 11 has the release layer 12, at the boundary surface between the release layer 12 and the hard coat layer forming layer 13, the base film 11 and the release layer 12, and as necessary. The release layer 18 including the antistatic layer 19 provided can be easily peeled from the decorative molded product 20. In this manner, a molded product is obtained in which the adhesive layer 16, the pattern layer 15, the anchor layer 14, and the hard coat layer forming layer 13 are sequentially laminated on the surface of the resin molded body 21.

<< Step (5) >>
Step (5) is a step of curing the hard coat layer forming layer 13 in the molded product obtained in step (4) to form a hard coat layer. In the curing of the step (5), when an ionizing radiation curable resin is used for forming the hard coat layer forming layer 13, it can be performed by irradiating ionizing radiation in an atmosphere having an oxygen concentration of 2% or less. Of these, it is preferable to perform the irradiation with an electron beam. By carrying out curing in this way, while maintaining the shape followability and formability of the decorative sheet, it is possible to achieve the contradictory performance of obtaining excellent high hardness and scratch resistance on a higher standard. It becomes possible.

  The atmosphere having an oxygen concentration of 2% or less can be obtained by, for example, nitrogen, argon, hydrogen, etc., preferably using nitrogen, or performing air suction so that the oxygen concentration is about 2% or less.

When the hard coat layer forming layer 13 is cured using a thermoplastic resin or a thermosetting resin, the hard coat layer forming layer 13 may be cured under a temperature condition sufficient to cure these resins. Moreover, when using ionizing radiation curable resin, it can carry out by irradiating ionizing radiations, such as an electron beam and an ultraviolet-ray.
When an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected according to the type of polymer or monomer to be used or the thickness of the hard coat layer forming layer 13, but usually an acceleration voltage of about 70 to 300 kV is preferable. The irradiation dose is usually selected in the range of 5 to 300 kGy (0.5 to 30 Mrad), preferably 10 to 50 kGy (1 to 5 Mrad). The electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type. Can be used.
When ultraviolet rays are used as the ionizing radiation, those containing ultraviolet rays having a wavelength of 190 to 380 nm are emitted, and the irradiation dose is about 500 to 1500 mJ. There is no restriction | limiting in particular as an ultraviolet-ray source, For example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a carbon arc lamp, etc. are used.

The decorative molded product thus obtained has excellent high hardness and excellent surface properties such as chemical resistance and stain resistance. In addition, by using the decorative sheet of the present invention that provides moldability that can correspond to a molded product having a more complicated shape, a decorative molded product that is excellent in finish can be obtained.
The decorative molded product of the present invention can be suitably used in a wide range of fields such as household electrical appliances and automobile interior parts, and in the field of personal computers, especially personal computer casings, taking advantage of these excellent characteristics. Can do.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example. In addition, the evaluation method in this invention was performed with the following method.
1. Preparation of test sample Release material used in each example and comparative example on a base film (“S-10 (product number)”, thickness: 38 μm, manufactured by Toray Industries, Inc., polyethylene terephthalate film, unadhesive layer untreated) A layer-forming coating solution was applied, and after drying the dryer, heat treatment was performed in an oven at 180 ° C. for 20 seconds to form a release layer of 0.9 g / m ² . Subsequently, the acrylic hard coat agent used in each example and comparative example was gravure printed at a coating amount of 5 g / m ² to form a hard coat layer forming layer, and an output variable type UV lamp system (“DRS-10 / 12QN (model number) ", manufactured by Fusion UV Systems Japan Co., Ltd.), irradiating with ultraviolet rays so as to obtain an integrated light quantity of irradiation dose: 25 mJ / cm ² , precuring the hard coat layer forming layer, A test sample was obtained.
2. Measurement of Peel Strength The test samples were measured for peel strength at 20 ° C. and 80 ° C. according to the method for measuring peel strength. Here, the peeling speed was about 300 mm / min. Moreover, about the decorating sheet | seat, the peeling strength after leaving to stand in the environment of 20 degreeC, 40 degreeC environment, and 40 degreeC90% RH each for 120 hours was measured according to said measuring method. Also, the peeling rate at this time was set to about 300 mm / min.
2. Evaluation of high hardness After a test sample is cured by the curing method in each of the examples and comparative examples, a pencil scratch coating film hardness tester (“D-NP” (model number) is used in accordance with JIS K5600-5-4. ) ”, Manufactured by Toyo Seiki Seisakusho Co., Ltd.), and a pencil scratch test pencil (manufactured by Mitsubishi Pencil Co., Ltd.).
The test of scratching the ink coating layer with a pencil of each hardness was conducted 5 times, and the pencil hardness of which the scar did not occur 3 times or more was defined as the pencil hardness of the test sample.

Example 1
(1) Manufacture of a decorative sheet The following release layer is formed on a base film (“S-10 (product number)”, thickness: 38 μm, manufactured by Toray Industries, Inc., polyethylene terephthalate film, unadhesive layer untreated). The coating liquid for coating was applied by gravure reverse coating so as to have a thickness of 1 μm and cured by heating to form a release layer. Next, gravure printing of acrylic hard coat agent (acrylic resin properties: weight average molecular weight: 300,000, glass transition temperature: 105 ° C., total content of monofunctional / polyfunctional acrylate, acrylate prepolymer: 5% by mass or less) To form a hard coat layer forming layer of 2 μm, gravure the wood grain pattern with acrylic printing ink to form a 3 μm thick pattern layer, and apply an acrylic coating liquid with a thickness of 2 μm to form an adhesive layer Formed. In addition, a coating solution (cationic surfactant: quaternary ammonium salt) containing a cationic surfactant as the main component is applied to the surface of the base film opposite to the surface provided with the release layer. Gravure printing was performed at an amount of 1 g / m ² to form an antistatic layer, and a decorative sheet of Example 1 was obtained. The peel strength was measured for the decorative sheet. The measurement results of peel strength are shown in Table 1.

(Release layer forming coating solution)
The following aqueous melamine resin and diluting solvent were stirred with a stirrer, an acid catalyst was added, and an aqueous polyester resin was further added to obtain a coating solution.
Aqueous melamine resin (melamine / formaldehyde alkyl monoalcohol (carbon number 1 to 12) condensate 80% by mass aqueous dispersion: less than 20% by mass, methanol: less than 2% by mass, formaldehyde: less than 0.8%): 100 parts by mass water-based polyester resin (“Vylonal MD1500 (product number)”, manufactured by Toyobo Co., Ltd., dispersion type, glass transition temperature (Tg) of resin: 77 ° C., number average molecular weight: 8000, hydroxyl value: 14 KOHmg / g, Acid value: 3 KOH mg / g or less): 5 parts by mass Acid catalyst (organic amine acid catalyst): 3 parts by mass Diluting solvent (Methanol and water are mixed at a ratio of 2: 1): 200 parts by mass

(2) Production of decorative molded product The decorative sheet obtained in (1) above was sucked into a mold heated to 70 ° C. and adhered to the inner surface of the mold. The mold used was of a shape with a high degree of deep drawing, having a 80 mm square size, a 10 mm rise and a 3R tray shape.
On the other hand, ABS resin (“Crustic MTH-2 (product number)”, manufactured by Nippon A & L Co., Ltd.) was used as the injection resin, and this was melted at 230 ° C. and then injected into the cavity. After cooling and taking out from the mold, the base film was peeled off to obtain a molded product having an adhesive layer, a printing layer, an anchor layer and a hard coat layer forming layer on the surface of the resin molded product in this order. Furthermore, using an output variable type UV lamp system (“DRS-10 / 12QN (model number)”, manufactured by Fusion UV Systems Japan Co., Ltd.) in an air atmosphere, the molded product is irradiated with ultraviolet rays at an irradiation dose of 1000 mJ. Then, the hard coat layer forming layer was cured to obtain a resin molded product of Example 1 as a hard coat layer.

3. Evaluation of foil flash In the obtained resin molded product, the state of foil flash was confirmed visually and evaluated according to the following criteria. The evaluation is shown in Table 1.
○: Foil flash was not confirmed at all. Δ: Foil flash was confirmed slightly, but there was no problem in practical use. X: Remarkable foil flash was confirmed. Evaluation of foil spillage The state of foil spillage when the obtained decorative sheet was slit-processed was visually confirmed and evaluated according to the following criteria. The evaluation is shown in Table 1.
○: Foil flash was not confirmed at all. Δ: Foil flash was confirmed slightly, but there was no problem in practical use. X: Remarkable foil flash was confirmed. Evaluation of Appearance (Moldability) The resulting resin molded product was evaluated for appearance (moldability) according to the following criteria. The evaluation is shown in Table 1.
◎: No coating cracks or whitening were observed in the hard coat layer (and its formation layer), and the shape of the mold was satisfactorily observed. ○: Slight coating cracks and minor changes in the hard coat layer (and its formation layer) △: Some coating cracks and slight whitening were confirmed in the hard coat layer (and its formation layer), but there were no practical problems. ×: Significant paint crack in the hard coat layer (and its formation layer) And whitening was confirmed. Evaluation of Appearance (Heat Resistance) Further, the appearance (heat resistance) around the gate part (resin injection part) of the obtained resin molded product was evaluated according to the following criteria. The evaluation is shown in Table 1.
◎: Deformation or whitening due to flow was not confirmed at all in the hard coat layer (and its formation layer) ○: Deformation or slight whitening due to slight flow was confirmed at the hard coat layer (and its formation layer) △: Slight deformation and slight whitening were confirmed in the hard coat layer (and its formation layer), but there was no problem in practical use. ×: Deformation and whitening due to significant flow was confirmed in the hard coat layer (and its formation layer). The

Example 2 and Comparative Example 1
In Example 1, the coating liquid for forming the release layer is shown in Table 1, and the hard coating agent for forming the hard coat layer forming layer is shown in Table 1. In the same manner as in Example 1, a decorative sheet and a decorative molded product were obtained. About the used decoration sheet, said high hardness evaluation, peeling strength measurement, and foil spill evaluation were performed, and said foil flash and external appearance evaluation were performed about the obtained decorative molded product. The results are shown in Table 1.

  The decorative sheet used in the examples imparts excellent hardness and formability to the decorative molded product, and also shows excellent performance in terms of foil spillage, and the decorative molded product using this is a foil It was confirmed that it was excellent in terms of evaluation of the beam and appearance. On the other hand, the decorative sheet used in the comparative example is insufficient in terms of foil spillage, and the decorative molded product obtained using the decorative sheet has not been excellent in terms of foil flash. In addition, it was confirmed that the peel strength of the decorative sheet used in the examples hardly changed before and after being left for 120 hours and maintained stable quality.

  According to the present invention, it is possible to suppress the occurrence of foil flashing and foil spillage, to produce a decorative molded product with excellent production efficiency, and to have good high hardness, excellent transferability and more complicated shape. It is possible to provide a decorative sheet imparting moldability to obtain a simple molded product, and a decorative molded product using the decorative sheet. Therefore, the present invention is effective in a wide range of fields such as household electric appliances, automobile interior parts, automobile exteriors, and mobile phone fields, and personal computer fields, especially personal computer housings.

DESCRIPTION OF SYMBOLS 10 Decorating sheet 11 Base film 12 Release layer 13 Hard coat layer forming layer 14 Anchor layer 15 Picture layer 16 Adhesive layer 17 Transfer layer 18 Peeling layer 19 Antistatic layer 20 Decorated molded body 21 Resin molded body 22 Hard coat layer

Claims (6)

  A decorative sheet having at least a release layer and a hard coat layer forming layer in order on one side of a base film, wherein the release layer is formed of a coating liquid containing a hydrophilic resin, and the release layer The decorative sheet having a peel strength at 20 ° C. of 0.06 to 0.4 N / 18 mm and a peel strength at 80 ° C. of 0.06 to 0.5 N / 18 mm.   The decorative sheet according to claim 1, wherein the hydrophilic resin is an aqueous melamine resin.   The decorative sheet according to claim 1 or 2, wherein the hydrophilic resin is a combination of a water-based melamine resin and a water-based polyester resin.   The decorative sheet according to any one of claims 1 to 3, further comprising an antistatic layer on a surface opposite to the surface on which the release layer of the base film is provided. The manufacturing method of the decorative molded product which has the following process (1) -process (5).
Step (1) Step of arranging the decorative sheet according to any one of claims 1 to 4 in an injection mold (2) Injection of molten resin into the cavity, cooling and solidification, and resin molding (3) Step of taking out a molded body in which the resin molded body and the decorative sheet are integrated from the mold (4) Base film of the decorative sheet from the molded body (5) Hard coat layer forming step for curing the hard coat layer forming layer provided on the molded body   A decorative molded product obtained by the production method according to claim 5.

Images