JP2018171708A - Protective film for decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective film for obtaining a decorative sheet which has a protective film for a decorative sheet peelable after molding provided on a decorative sheet, is peeled after molding, and is excellent in appearance, from the viewpoints such as (1) blocking prevention, (2) scratch prevention, (3) scratch prevention during printing and molding, (4) during trimming, (5) die mark prevention during injection molding and (6) stain prevention until a decorative molded body after molding is used, in production of the decorative sheet.SOLUTION: This invention relates to a protective film 101 for a decorative sheet which has at least one base material, and an adhesive layer. A storage modulus of a base material layer 12 at 80°C is 5×10to 1×10Pa, and a storage modulus at 160°C is 5×10to 6×10Pa. In the whole protective film 101, a storage modulus at 80°C is 4×10to 1×10Pa; and a storage modulus at 160°C is 1×10to 4×10Pa.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a protective film for a decorative sheet for protecting the hard coat surface of a decorative sheet having a hard coat layer formed on a surface thereof from a specific acrylic paint.

  Resin-molded products are often used for portable information terminal devices such as smartphones, notebook computers, home appliances, and automobile interior and exterior parts. In order to improve the designability of these resin molded products after molding a plastic resin, the surface is usually decorated by painting or printing.

  Conventionally, a colored paint has been applied or printed on the surface of a resin molded product in order to impart design properties. Also, in order to protect the surface from scratches and fingerprints, the surface of the resin molded product has been spray-coated or dipped with a hard coat paint. However, it is difficult for such a conventional decoration method to perform decoration with high designability. Moreover, for reasons such as difficulty in productivity, a method for decorating the surface of a resin molded product using a decorative sheet has been widespread as an alternative method. A decorative sheet is a base film provided with a pattern or a hard coat layer by printing or coating.

  As a method of using a decorative sheet, (1) a method in which a resin molded product molded in advance is a target for decoration, and a decorative sheet is laminated on the surface of the resin molded product, or (2) set in a mold. There is a method of injecting a resin for injection molding to be decorated on the decorated sheet and integrating the resin molded product and the decorated sheet. In the method (2), the decorative sheet can be preformed prior to the injection of the resin for injection molding. Examples of the preforming means include vacuum molding, mechanical molding, and the like.

The use of various decorative sheets is proposed in Patent Documents 1-8.
Patent Document 1 describes a multilayer body in which a layer made of an acrylic resin and a layer made of an aliphatic polycarbonate resin are laminated. It is described that a multilayer body excellent in transparency, heat resistance, impact resistance, UV discoloration resistance, and surface hardness can be obtained by using an aliphatic polycarbonate resin having a specific structure.

  In Patent Document 2, as a resin film that is difficult to break, has excellent whitening resistance, has high surface hardness, and is easy to mold, a methacrylic resin (with a glass transition temperature of the polycarbonate resin) is formed on at least one surface of the polycarbonate resin material layer. A multilayer film formed by laminating a layer of a methacrylic resin material containing 85 to 100 parts by mass (having a predetermined relationship with the glass transition temperature of the material) and 0 to 15 parts by mass of acrylic rubber particles is disclosed. Further, it is also disclosed that the multilayer film is suitably used as a surface decorating sheet such as an exterior member for home appliances or an interior member for automobiles. It has been suggested that a polymer of methyl methacrylate is suitable as the methacrylic resin.

In Patent Document 3, using an ink composition for a hard coat layer having ionizing radiation curability,
Step (1) In the injection mold, at least a release layer and a hard coat layer forming layer formed by coating an ink composition for hard coat layer having ionizing radiation curability on one side of the base film in order. A step of arranging a decorative sheet having,
Step (2) An injection step of injecting molten resin into the cavity, cooling and solidifying, and laminating and integrating the resin molded body and the decorative sheet,
Step (3) Step of taking out a molded body in which a resin molded body and a decorative sheet are integrated, from a mold,
Process (4) The process of peeling the base film of a decorating sheet from a molded object,
Step (5) a hard coat layer forming step of curing the hard coat layer forming layer provided on the molded body in an atmosphere having an oxygen concentration of 2% or less,
A method for producing a decorative molded product through each of the steps is disclosed.

  Patent Document 4 discloses a laminated hard coat film for molding in which a hard coat layer containing a resin is provided on a base film, and the elongation of the laminated hard coat film in an atmosphere of 23 ° C. and 50% RH. A laminated hard coat film for molding having a rate of 10% or more is disclosed. As the resin contained in the hard coat layer, an active energy ray curable resin is used.

  Patent Document 5 discloses a resin composition containing at least a polymer having a hydroxyl group and a carboxyl group, a polyisocyanate, and a prepolymer having three or more acryloyl groups or methacryloyl groups in one molecule on a peelable gas film. The transfer film obtained by applying to the above is described (claims 1 and 5). In claim 2, the polymer is a polymerizable monomer comprising a polymerizable monomer having a hydroxyl group and an unsaturated double bond and a polymerizable monomer having an unsaturated double bond having a carboxyl group. In claim 3, the polymer has a hydroxyl value of 5 to 100 mgKOH / g, a weight average molecular weight of 30,000 to 300,000, and a polymer obtained by copolymerizing a polymer mixture. It is described that the glass transition temperature is 60 to 180 ° C.

  Patent Document 6 discloses a laminated sheet that can be integrally formed with a cured resin layer as a topcoat layer (Claim 1). In Claims 2 and 3, the cured resin layer of the topcoat layer has a hydroxyl value of 10 to 300 mgKOH / g, a weight average molecular weight of 2,000 to 50,000, and a glass transition temperature (Tg) of 80 ° C. or less. It is described that it is a resin layer obtained by curing a resin composition comprising a hydroxyl group-containing vinyl copolymer and a polyisocyanate compound.

In Patent Document 7, a protective film in which a transparent protective resin layer is laminated on one side of a plastic film is heated to 100 to 140 ° C. and placed in a compressed air type, and 200 to 300 is placed in a compressed air box combined with the compressed air type. A protective film shaping step for obtaining a shaped protective film shaped into the mold surface shape by blowing heated compressed air at 8 ° C. and 15 to 15 MPa to bring the protective film into close contact with the compressed air mold surface; The shape protective film is disposed in the injection mold so that the protective resin layer side faces one mold surface of the injection mold, and the substrate protective resin is injected into the injection mold to form the shape protective film. A multilayer resin molded product in which the shaped protective film and the base material are integrated is obtained by a film insert injection molding process in which a base material is laminated on the opposite side of the protective resin layer. A method for producing a multilayer resin molded product characterized by the above is described.

Furthermore, Patent Document 8 discloses a laminated decorative film product useful for molding parts or panels for vehicle bodies and other uses.
A layer of thermoformable decorative material that can be an outer surface finish for a part or panel, and said decorative material removably secured to the decorative material, prior to, during, and after subsequent molding operations A first protective layer of a thermoformable plastic film capable of limiting damage to the surface, and removably secured to the first protective layer of the thermoformable film until the first protection until removed prior to the molding operation There has been proposed a laminated decorative film product comprising a second protective layer of a flexible plastic film capable of limiting damage to the layer.

However, these films do not have heat resistance enough to withstand the molding temperature, and foaming occurs at the molding temperature or peeling occurs due to film shrinkage, and the foamed traces remain as irregularities on the hard coat surface. Could not protect. Even if there is no damage to the protective film at the time of molding, the protective film foams or melts due to the high heat of the injection molten resin in the injection process after trimming, and it is pressed by the pressure in the mold and hard coat surface As a result, the surface of the hard coat was not only impaired, but also the resin was fused to the mold due to the melting of the base film, resulting in contamination. Also, in press molding, foreign matter adhering to the mold surface may be pressed against the hard coat surface, resulting in unevenness.

Can be applied to the hard coat surface of these decorative sheets in the whole process of printing, vacuum forming, trimming, and injection molding, and prevents irregularities caused by mixing of foreign matter such as burrs and ink pieces by trimming the hard coat surface. There is a need for protective film for decorative molding. Up to now, self-adhesive films by polyethylene or polypropylene single-layer or multi-layer coextrusion have been the mainstream as protective films for decorative molding, but these films do not have heat resistance to withstand the molding temperature and are molded. Foaming was caused by temperature or peeling occurred due to shrinkage of the film, and the foamed trace remained as irregularities on the hard coat surface, and the surface could not be protected. Even if there is no damage to the protective film at the time of molding, the protective film foams or melts due to the high heat of the injection molten resin in the injection process after trimming, and it is pressed by the pressure in the mold and hard coat surface As a result, the surface of the hard coat was not only impaired, but also the resin was fused to the mold due to the melting of the base film, resulting in contamination.

JP 2011-161871 A JP 2010-125645 A JP 2011-161692 A JP 2012-210755 A JP 2010-126633 A JP 2002-347179 A JP 2007-331185 A WO97 / 48776

(1) Blocking prevention, (2) Scratch prevention, (3) Scratch prevention during printing, molding, (4) Trimming, (5) Mold trace prevention during injection molding, (6) From the standpoint of preventing stains before use of the decorative molded body after molding, a protective film for the decorative sheet that can be peeled off after molding is provided on the decorative sheet, and then peeled off after molding. It aims at obtaining the decoration sheet excellent in.

  As a result of intensive studies, the present inventors have found that a specific decorative molding protective film solves the above-described problems, and have completed the present invention.

That is, the present invention is a decorative sheet protective film having at least one base material layer and an adhesive layer, and the storage elastic modulus of the base material layer at 80 ° C. is 5 × 10 ⁷ to 1 × 10 ¹⁰ Pa. And the storage elastic modulus in 160 degreeC is 5 * 10 < ⁵ > -6 * 10 < ⁸ > Pa, It is related with the protective film for decorative sheets characterized by the above-mentioned.

A protective film for a decorative sheet laminated in the order of at least a first base material layer, an adhesive layer, a second base material layer, and an adhesive layer, and storing the first base material layer at 80 ° C. The elastic modulus is 5 × 10 ⁷ to 1 × 10 ¹⁰ Pa and the storage elastic modulus at 160 ° C. is 1 × 10 ^{6 to} 5 × 10 ⁸ Pa, and the storage elastic modulus at 80 ° C. of the second base material layer is 1 ×. The storage elastic modulus at 10 ⁸ to 1 × 10 ¹⁰ Pa and 160 ° C. is 1 × 10 ⁶ to 1 × 10 ⁹ Pa. The protective film for a decorative sheet according to claim 1.

The storage elastic modulus at 80 ° C. of the entire decorative sheet protective film is 4 × 10 ⁷ to 1 × 10 ⁹ Pa and the storage elastic modulus at 160 ° C. is 1 × 10 ⁷ to 4 × 10 ⁸ Pa. It relates to the protective film for a decorative sheet according to Item 1 or 2.
Furthermore, it is related with the protective film addition decoration sheet characterized by laminating a decoration sheet on the outer side of the adhesive layer of the protection film for decoration sheets.

Furthermore, it is related with the manufacturing method of the decoration molded object characterized by having the following process.
(Step 1) Step of shaping the protective film-added decorative sheet,
(Step 2) A step of injection-molding a resin to the shaped protective film-added decorative sheet,
(Step 3) A step of removing the protective film from the injection-molded protective film-added decorative sheet.

  ADVANTAGE OF THE INVENTION By this invention, the decoration molded product excellent in the external appearance which does not have a damage | wound and an unevenness | corrugation on the hard coat surface of a decorating sheet can be provided.

Typical sectional drawing which shows the structural example of the protective film for decorating sheets of this invention. Typical sectional drawing which shows the structural example of the protective film for decorating sheets of this invention. Typical sectional drawing which shows the structural example of the protective film for decorating sheets of this invention. Typical sectional drawing which shows the structural example of the protective film for decorating sheets of this invention. The typical sectional view showing the example of composition of the decorating sheet of the present invention. The typical sectional view showing the example of composition of the decorating sheet of the present invention. The typical sectional view showing the example of composition of the decorating sheet of the present invention. The typical sectional view showing the example of composition of the decorating sheet of the present invention. The typical sectional view showing the example of composition of the decorating sheet of the present invention. The typical sectional view showing the example of composition of the decorating sheet of the present invention. The typical sectional view showing the example of composition of the decorating sheet of the present invention.

The detail of the protective film for decorative sheets is described below.

[Protective film for decorative molding]
A protective film for a decorative sheet having at least one base material and an adhesive layer, wherein the base material layer has a storage elastic modulus at 80 ° C. of 5 × 10 ⁷ to 1 × 10 ¹⁰ Pa and 160 ° C. It is a protective film for decorative sheets, characterized in that the rate is 5 × 10 ^{5 to} 6 × 10 ⁸ Pa.

<Base material layer>
The protective film for a decorative sheet of the present invention has a storage elastic modulus of 5 × 10 ⁷ to 1 × 10 ¹⁰ Pa at 80 ° C. of at least one kind of the base material layer, and a storage elastic modulus of 160 ° C. of 5 × 10 ^5. It is in the range of ˜6 × 10 ⁸ Pa. When the storage elastic modulus at 80 ° C. is less than 5 × 10 ⁷ Pa, dents are likely to appear in the mold. Further, if it exceeds 1 × 10 ¹⁰ Pa, dents are hardly produced, but when the molding temperature of the decorative sheet is low, it is too hard to be molded.
Moreover, when the storage elastic modulus in 160 degreeC is less than 5 * 10 < ⁵ > Pa, there is no heat resistance at the time of shaping | molding, A film is torn or it melt | dissolves and marks a hard-coat surface.
When the storage elastic modulus at 160 ° C. exceeds 6 × 10 ⁸ Pa, it is not desirable because it becomes impossible to perform precise molding even with a normal vacuum / pressure molding machine or a high-pressure molding machine.

As a base material for a decorative sheet protective film, a base material that does not change in appearance and has a small dimensional change when printing or molding a decorative sheet is preferable, and a molding process in vacuum molding, pressure molding, or vacuum pressure molding. What can be done is preferred. What is the hard coat layer of the decorative sheet when burrs (debris of the decorative sheet) and ink pieces (debris of the film formed by drying the ink) generated when trimming during injection molding adhere to the surface? It preferably has a property of relaxing and absorbing the pressure (in-mold pressure) of the molten resin injected to the back surface of the molding resin on the opposite side. In order to maintain the smoothness of the hard coat, it is preferable that the base material surface in contact with the hard coat surface has high smoothness.
The base material is obtained by laminating at least one kind or two or more kinds, but this combination is changed depending on the molding temperature and the molding temperature (molding, injection molding) of the plastic base material for forming the decorative sheet. If two or more layers are laminated, a dry laminate adhesive, pressure-sensitive adhesive, hot melt adhesive, etc. may be provided between the two layers. If the substrate is a thermoplastic resin, it is laminated by heating lamination. May be.

As a further desirable configuration of the present invention, there is provided a protective film for a decorative sheet laminated in the order of at least a first base layer, an adhesive layer, a second base layer, and an adhesive layer, wherein The storage elastic modulus at 80 ° C. of the base material layer is 5 × 10 ⁷ to 1 × 10 ¹⁰ Pa and the storage elastic modulus at 160 ° C. is 1 × 10 ^{6 to} 5 × 10 ⁸ Pa, and 80 of the second base material layer. A protective film for a decorative sheet having a storage elastic modulus at 1 ° C. of 1 × 10 ⁸ to 1 × 10 ¹⁰ Pa and a storage elastic modulus at 160 ° C. of 1 × 10 ⁶ to 1 × 10 ⁹ Pa.
When the storage modulus at 80 ° C. of the first base material layer is less than 5 × 10 ⁷ Pa, the film adheres in the mold and it becomes difficult to remove the molded product, or the mold is soiled. On the other hand, when it exceeds 1 × 10 ¹⁰ Pa, it is too hard to be molded.
Moreover, when the storage modulus at 160 ° C. of the first base material layer is less than 1 × 10 ⁶ Pa, the heat resistance as the base material is insufficient, and foaming occurs due to shaping heat, or the base material is torn. . Furthermore, if it exceeds 5 × 10 ⁸ Pa, it will be too hard to perform precise molding.
Moreover, when the storage elastic modulus in 80 degreeC of a 2nd base material layer will be less than 1 * 10 < ⁸ >, heat resistance will run short and a base material will foam. When it exceeds 1 × 10 ¹⁰ Pa, it is too hard to be molded.
Moreover, when the storage elastic modulus in 160 degreeC of a 2nd base material layer is less than 1 * 10 < ⁶ > Pa, the heat resistance as a base material is insufficient, it foams with the heat of shaping, or a base material is torn. . If it exceeds 1 × 10 ⁹ Pa, it will be too hard and precise molding will not be possible.

  Examples of the base material include polyethylene terephthalate, polybutylene terephthalate, polymethylpentene, urethane, polypropylene, and the like, and they can be suitably used within the range of the storage elastic modulus. Note that a film substrate in which two to three layers are simultaneously formed by coextrusion is a single layer substrate. A protective film substrate can be obtained by laminating one or two or more of these film substrates, but this combination is based on the molding temperature and the molding temperature of the molding plastic substrate that forms the decorative sheet (molding). , Injection molding).

  What is necessary is just to set the thickness of a base material suitably in the range of 30-1000 micrometers by layer thickness, More desirably, 100-300 micrometers is desirable from the point of a moldability and heat resistance. When the thickness is 300 μm or more, the pressure-sensitive adhesive at the time of injection molding is hardly cooled on the mold surface, and the heat resistance of the pressure-sensitive adhesive becomes severe and the molded film is likely to be warped.

<Adhesive layer>
The adhesive layer provided between the base material layers is used to bond the two base materials, and foams or melts from the end when printing is dried, shaped, and injection molded. Heat resistance and adhesiveness that do not flow and do not peel off during molding are required.
When two or more substrate layers are laminated, a conventionally known dry laminate adhesive, pressure-sensitive adhesive, hot melt adhesive, etc. may be provided between the layers. If the substrate is a thermoplastic resin, it is laminated by heating lamination. May be.
As the resin suitable for the adhesive, acrylic resin, polyurethane resin, polyester resin, vinyl chloride resin, vinyl acetate resin, polyamide resin, polyimide resin, polyester polyurethane, polyurea resin, etc. are used. What is necessary is just to use it by bridge | crosslinking with an aziridine crosslinking agent, an epoxy crosslinking agent, a metal chelating agent etc., improving heat resistance, or adjusting adhesive force.

<Adhesive layer>
The adhesive of the pressure-sensitive adhesive layer used for attaching the protective film to the hard coat surface is a (meth) acrylic ester resin, (meth) acrylic acid, itaconic acid, (anhydrous) maleic acid, (anhydrous) Polymerizable monomer having a non-carboxyl group such as fumaric acid or crotonic acid or its anhydride, alkyl (meth) acrylate [methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate , Isooctyl (meth) acrylate, lauryl (meth) acrylate, etc.], mono (meth) acrylate such as 2-hydroxyethyl (meth) acrylate, di (meth) acrylate such as diethylene glycol di (meth) acrylate, hexanediol (meth) acrylate, etc. Acrylate, pentaerythri Homopolymers of monomers selected from (meth) acrylic monomers, such as tri (meth) acrylates such as tall tri (meth) acrylate, (meth) acrylamide, (meth) acrylamide such as N, N-dimethyl (meth) acrylamide, In addition, there are multi-polymers such as copolymers and terpolymers selected from two or more.
Furthermore, the copolymer of the said (meth) acrylic-type monomer and vinyl compounds other than (meth) acrylic-type monomers, such as vinyl acetate, N-vinyl pyrrolidone, N-vinyl piperidone, N-vinyl caprolactam, and styrene, is mentioned.

These are obtained by reacting at a temperature of 40 to 100 ° C. for 2 to 8 hours using a radical polymerization initiator such as an organic peroxide polymerization initiator or an azo polymerization initiator, and have a weight average molecular weight. Those having (Mw) of 100,000 to 1,000,000 can be suitably used.

As the curing agent used for the pressure-sensitive adhesive layer, a compound having a functional group capable of reacting with a carboxyl group is used. In this case, as a crosslinking agent, for example, a bisamide-based crosslinking agent (for example, 1,1′-isophthaloyl-bis (2-methylaziridine)), an aziridine-based crosslinking agent (for example, Nippon Shokubai Chemite PZ33, Avisia NeoCryl CX-100) ), Carbodiimide-based crosslinking agents (for example, Nisshinbo Carbodilite V-03, V-05, V-07), epoxy-based crosslinking agents (for example, E-AX, E-5XM, E5C manufactured by Soken Chemical), isocyanate-based crosslinking agents ( For example, Coronate L, Coronate HK, Death Module H, Death Module W, Death Module I) manufactured by Japan Polyurethane can be used, and it is particularly desirable to contain an aziridine-based curing agent.

It is preferable to contain 0.1-15 weight part of hardening | curing agents with respect to 100 weight part of resin (a), 1.1 mol or less with respect to 1 mol of functional groups in resin (a), Preferably it is 0.00. The range of 01-0.8 mol is preferable from the balance with physical properties. When it is desired to reduce the adhesive strength, a larger amount of the curing agent can be used, and when it is desired to increase the adhesive strength, a smaller amount of the curing agent can be added.

Cellulose can also be used as an additive in the adhesive.
The cellulose that can be used for the pressure-sensitive adhesive is any one of cellulose acetate, cellulose acetate butyrate (hereinafter also referred to as CAB), and cellulose acetate propionate (hereinafter also referred to as CAP), and preferably CAB and CAP. Can also be used together.
In addition, the use of nitrocellulose (hereinafter also referred to as NC) or ethyl cellulose as cellulose can be expected to have an effect of reducing the dependency on the peeling rate. However, as described above, yellowing occurs when a temperature of 160 ° C. or higher is applied. There are problems in heat resistance, such as partly disassembling or causing cohesive failure to reduce re-peelability.

The pressure-sensitive adhesive used in the present invention can contain 1 to 60 parts by weight of the cellulose (c) with respect to 100 parts by weight of the resin (a), preferably 10 to 50 parts by weight.
When the cellulose (c) is less than 1 part by weight, the peeling force at the time of high-speed peeling is remarkably increased, and workability at the time of peeling off the protective film and the like is lowered. On the other hand, when the cellulose (c) exceeds 60 parts by weight, the peeling force itself is hardly affected by the peeling speed, but the pressure-sensitive adhesive layer itself becomes too hard and it is difficult to ensure the performance as a pressure-sensitive adhesive.

If the cellulose (b) is contained in an amount of 1 to 60 parts by weight with respect to 100 parts by weight of the resin (a), the peeling force is hardly affected by the peeling speed.
Moreover, it is preferable that the peeling force at the time of low speed peeling is the range of 10-1000 mN / 25mm.

(Organic solvent)
The pressure-sensitive adhesive used in the present invention is a removable pressure-sensitive adhesive and is a solvent type, that is, an organic solvent-soluble type, and contains an organic solvent. Various organic solvents can be used. For example, toluene and ethyl acetate are the main components, and methyl ethyl ketone, acetone, isopropyl alcohol, ethanol, methanol, rubber volatile oil, hexane, heptane, butyl acetate, and the like can be used as appropriate.

In addition to the additives such as tackifier resins, plasticizers, thickeners, antioxidants, UV absorbers, various stabilizers, wetting agents, flame retardants, various drugs, etc. A curing agent, a curing accelerator and the like can be used in combination.

Examples of tackifiers include terpene resins, aliphatic petroleum resins, aromatic petroleum resins, coumarone-indene resins, styrene resins, phenolic resins, terpene-phenolic resins, rosin derivatives (rosin, polymerized rosin, hydrogenated All existing ones such as rosin and esters thereof with glycerin, pentaerythritol, etc., resin acid dimers, etc. can be used. As the plasticizer, known materials such as phthalates and phosphates can be used.

(Method for forming pressure-sensitive adhesive layer)
The pressure-sensitive adhesive layer is a layer in which a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive dissolved in the above-described solvent is uniformly provided on one side of the base material of the protective film, and can be produced by various production methods.
For example, roll separators, comma coaters, knife coaters, lip coaters, film separators such as peeled paper separators, polylamiclasine paper separators, peeled polyethylene terephthalate (PET) separators, peeled polyolefin separators, etc. Apply a pressure-sensitive adhesive using a known coating machine such as curtain coater, gravure coater, spin coater, silk screen coating machine, etc., and dry to form a pressure-sensitive adhesive layer. The substrate is pasted by roll lamination.
Or, if there is no concern that the protective film substrate swells or dissolves with a solvent or shrinks at the drying temperature, apply adhesive to the protective film substrate and attach the peelable substrate with roll laminate. There is no problem.
After peeling the base material peel-treated from the protective film for a decorative sheet prepared as described above, the laminate is roll-laminated on the hard coat surface on the decorative sheet.
Furthermore, it is possible to apply a pressure-sensitive adhesive directly to the cured hard coat layer and roll laminate the base material for the protective film.

  What is necessary is just to set the thickness of an adhesive layer suitably in view of adhesive force, holding power, and removability in the range of 1-100 micrometers by dry film thickness, More preferably, the range of 5-50 micrometers is heat resistance, adhesive strength, and holding | maintenance. Desirable in terms of strength, removability, and solvent drying. If it is 5 μm or less, the adhesive strength is weak, and peeling may occur in the middle of molding, and if it is 50 μm or more, re-peelability may be reduced.

Furthermore, the storage elastic modulus at 80 ° C. of the whole decorative film for decorative sheet is 4 × 10 ⁷ to 1 × 10 ⁹ Pa and the storage elastic modulus at 160 ° C. is 1 × 10 ⁷ to 4 × 10 ⁸ Pa. To do.
When the storage elastic modulus at 80 ° C. is less than 4 × 10 ⁷ Pa, there is no heat resistance, and foaming occurs or the film curls and peels off. If the storage elastic modulus is larger than 1 × 10 ⁹ Pa, it is too hard to be molded.
Further, when the storage elastic modulus at 160 ° C. is smaller than 1 × 10 ⁷ Pa, the film has no heat resistance, and the film is wrinkled or broken at the time of molding, and when it is larger than 4 × 10 ⁸ Pa, molding is difficult.

<Protective film for decorative sheet>
There exist the following aspects in the protective film for decorating sheets.
In FIG. 1, the protective film 101 which consists of a 2 layer structure of the base material 11 and the adhesive layer 12 is shown.
The protective film 102 which consists of the structure which adhere | attached two types of base materials 11a and the base materials 11b on FIG. 2 with the adhesive 12a.
FIG. 3 shows a protective film 103 having a configuration in which two types of base materials 11 a and 11 b are bonded with an adhesive 13.
FIG. 4 shows a protective film 104 composed of a base material layer and a pressure-sensitive adhesive layer 12 in which two types of base materials 11a and 11b are bonded together by coextrusion or heat lamination.

<Method of manufacturing protective film for decorative sheet>
The decorative sheet protective film can be provided on the decorative sheet by the following production method.
1) A pressure-sensitive adhesive solution is applied to a film that has been subjected to a release treatment, dried with hot air at 80 to 100 ° C, laminated with a base film, and aged at room temperature to 100 ° C for 1 week. Thereafter, the release film is peeled off and laminated by laminating on the hard coat layer of the decorative sheet.
2) Apply the adhesive solution on the anti-blocking film stuck on the hard coat layer or hard coat layer of the decorative sheet, dry with hot air at 80-100 ° C, and then laminate the base film of the protective film Aging at room temperature to 100 ° C. for 1 week.
3) A pressure-sensitive adhesive solution is applied onto the base film, dried with hot air at 80 to 100 ° C., and then laminated on the hard coating layer of the decorative sheet or the anti-blocking film attached on the hard coating layer. Aging at room temperature to 100 ° C. for a week.
Although it is not limited to the above manufacturing method, the manufacturing method of 1) is desirable in order to finally remove the adhesive without leaving the adhesive from the hard coat layer as a protective film.

[Decorative sheet]
Next, the decorative sheet to which the protective film for decorative sheets is attached will be described.
<Hard coat layer>
As a composition for forming a hard coat layer of a decorative sheet, basically a conventionally known composition can be used without particular limitation in this type of insert molding film, and typically a UV curable resin. It is classified into an ultraviolet curing type containing (d) and a photopolymerization initiator (e), and a thermosetting type using an acrylic copolymer (f) having a hydroxyl group and an isocyanate curing agent (g). .

(UV curing type)
Examples of the ultraviolet curable type ultraviolet curable resin (d) include urethane (meth) acrylate (oligomer), epoxy (meth) acrylate (oligomer), polyester (meth) acrylate (oligomer), polyether (meth) acrylate ( One or more selected from the group consisting of oligomers), (meth) acrylates (oligomers) and the like can be used.

The photopolymerization initiator (e) is used as a polymerization initiator when the hard coat layer forming composition is cured by ultraviolet rays (UV) to form a coating film. The photopolymerization initiator (e) is not particularly limited as long as it initiates polymerization by ultraviolet irradiation, and known compounds can be used. For example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -One, acetophenone polymerization initiators such as 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, benzoin, 2,2-dimethoxy 1,2 -Benzoin polymerization initiators such as diphenylethane-1-one, benzophenone, [4- (methylphenylthio) phenyl] phenylmethanone, 4-hydroxybenzophenone, 4-phenylbenzophenone, 3,3 ', 4,4' -Benzophenone polymerization initiators such as tetra (t-butylperoxycarbonyl) benzophenone, 2-chlorothio Sandton, such thioxanthone type polymerization initiators such as 2,4-diethyl thioxanthone, and the like. These photopolymerization initiators (e) may be used alone or in combination of two or more.
(Thermosetting type)
The thermosetting type hard coat layer is obtained by applying and curing a paint containing an acrylic copolymer (f) having a hydroxyl group and an isocyanate curing agent (g). Thereby, it is possible to achieve both moldability and surface hardness, which cannot be obtained with an acrylic resin film obtained by melt extrusion of a thermoplastic acrylic resin. Moreover, the light resistance which cannot be obtained with a UV curable acrylic resin film can be ensured.

<Acrylic copolymer having a hydroxyl group>
The acrylic copolymer (f) having a hydroxyl group can be obtained by copolymerizing a monomer having a hydroxyl group and another monomer having no hydroxyl group. That is, the acrylic copolymer is a copolymer composed of a unit derived from a monomer having a hydroxyl group and a unit derived from another monomer.

  Examples of the monomer having one hydroxyl group include hydroxyalkyl (meth) acrylate and compounds obtained by adding ε-caprolactone to the hydroxyalkyl (meth) acrylate, and hydroxyalkyl (meth) acrylate is preferable.

Specific examples of the hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Examples thereof include hydroxyalkyl (meth) acrylates having 1 to 4 carbon atoms in the alkyl group such as hydroxybutyl (meth) acrylate.
Specific examples of compounds obtained by adding ε-caprolactone to hydroxyalkyl (meth) acrylate include 1 mol of ε-caprolactone adduct of 2-hydroxyethyl (meth) acrylate, 2 mol of ε-caprolactone of 2-hydroxyethyl (meth) acrylate. Examples of the adduct include an ε-caprolactone adduct of a hydroxyalkyl (meth) acrylate having 1 to 4 carbon atoms, such as an adduct, an ε-caprolactone 3 mol adduct of 2-hydroxyethyl (meth) acrylate, and the like. It is not limited only to such illustration. These hydroxyl group-containing monomers may be used alone or in combination.

  Examples of the monomer having two or more hydroxyl groups include 1,1-dihydroxymethyl (meth) acrylate, 1,2-dihydroxyethyl (meth) acrylate, 2,2-dihydroxyethyl (meth) acrylate, and 2,3- Dihydroxypropyl (meth) acrylate and (meth) acryloyl monomer having an epoxy group in one molecule are reacted with one functional group capable of reacting with an epoxy group and a compound having a hydroxyl group or water in one molecule, Although the monomer etc. which are obtained by ring-opening of an epoxy group are mentioned, this invention is not limited only to this illustration. These hydroxyl group-containing monomers may be used alone or in combination.

  The hydroxyl value of the acrylic copolymer is preferably 5 to 210 mgKOH / g. When the hydroxyl value of the acrylic copolymer is 5 mgKOH / g or more, the durability of the cured film can be secured, and when it is 210 mgKOH / g or less, the moldability of the cured film can be secured. From the viewpoint of adhesion to the base material, for example, when a paint made of an acrylic copolymer is applied and laminated on a polycarbonate base material, the hydroxyl value of the acrylic copolymer (A) is 50 mgKOH / g or less is preferable. When the hydroxyl value is 50 mgKOH / g, the hard coat layer and the polycarbonate base material layer are in good contact. Moreover, when using another base material, it is more preferable that it is 150 mgKOH / g or less. When the hard coat layer is isolated (referred to as a cast film) and bonded to the base material layer using an adhesive, the hydroxyl group is preferably 50 mgKOH / g or more from the viewpoint of film strength, and more preferably 70 mgKOH / g. More preferably.

  Examples of other acrylic monomers having no hydroxyl group include various monomers as shown below. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and sec-butyl (meth). Acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, Examples include alkyl (meth) acrylates such as tert-butylhexyl (meth) acrylate, 2-acetoacetoxyethyl (meth) acrylate, and phenoxyethyl (meth) acrylate.

  As a monomer having an alicyclic hydrocarbon group, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, Examples thereof include dicyclopentenyl (meth) acrylate and dicyclopentanyl (meth) acrylate.

  Examples of the monomer having an epoxy group include glycidyl (meth) acrylate, α-methylglycidyl acrylate, α-methylglycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, and the like.

  The acrylic copolymer (f) having a hydroxyl group is preferably obtained by polymerizing a methacrylate monomer among the various monomers described above.

  Examples of the method for polymerizing the monomer include a solution polymerization method, a bulk polymerization method, a suspension polymerization method, and an emulsion polymerization method, but the present invention is not limited to such a polymerization method. Among these polymerization methods, the solution polymerization method is preferable because the obtained reaction mixture can be used as it is.

  Below, one embodiment in the case of preparing the acrylic copolymer (f) which has a hydroxyl group by solution-polymerizing a monomer is demonstrated. However, the present invention is not limited only to the embodiment.

  Examples of the solvent used for solution polymerization of the monomer include aromatic solvents such as toluene and xylene; alcohol solvents such as n-butyl alcohol, propylene glycol monomethyl ether, diacetone alcohol, and ethyl cellosolve; ethyl acetate, Examples thereof include ester solvents such as butyl acetate and cellosolve acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; dimethylformamide and the like, but the present invention is not limited to such examples. The amount of the solvent is preferably appropriately determined according to the concentration of the monomer mixture, the molecular weight of the target acrylic copolymer, and the like.

  Examples of the polymerization initiator include 2,2′-azobis- (2-methylbutyronitrile), tert-butylperoxy-2-ethylhexanoate, 2,2′-azobisisobutyronitrile, benzoyl Although a peroxide, di-tert-butyl peroxide, etc. are mentioned, this invention is not limited only to this illustration. The amount of the polymerization initiator is usually preferably 0.01 to 30 parts by mass, more preferably 0.05 to 10 parts by mass per 100 parts by mass of the monomer mixture. When the mass average molecular weight (Mw) is 100,000 or more as in the present invention, the amount of the polymerization initiator is preferably 0.05 to 0.1 parts by mass.

  The polymerization temperature when the monomer is polymerized is usually preferably 40 to 200 ° C, more preferably 40 to 160 ° C. When the mass average molecular weight (Mw) is 100,000 or more as in the present invention, the polymerization temperature is preferably 90 ° C. or less.

  Since the polymerization time of the monomer varies depending on the polymerization temperature, the composition of the monomer mixture, the type and amount of the polymerization initiator, and cannot be determined unconditionally, it is preferably determined appropriately according to them.

The acrylic copolymer (f) may have an acid value. Since the reaction between the hydroxyl group and the isocyanate is promoted by having an acid value, a cured film having high durability can be obtained. When providing an acid value, it is preferable that the acid value of an acrylic copolymer (f) is 20 mgKOH / g or less. When the acid value is 20 mgKOH / g or less, durability can be imparted without impairing moldability. The acid value is more preferably 15 mgKOH / g or less.
The method for imparting an acid value to the acrylic copolymer (f) is obtained by copolymerizing a monomer having an acid value with another monomer. Examples of the monomer having an acid value include (meth) acrylic acid, maleic anhydride, 2- (meth) acryloyloxyethyl-succinic acid, 2- (meth) acryloyloxyethyl-hexahydrophthalic acid, 2- (meth) ) Acryloyloxyethyl-phthalic acid, 2- (meth) acryloyloxyethyl acid phosphate, and the like. Among them, (meth) acrylic acid is preferably used.

  The acrylic copolymer (f) preferably has a glass transition temperature of 0 to 95 ° C. When the glass transition temperature is 0 ° C. or higher, good scratch resistance and wear resistance are obtained, and when it is 95 ° C. or lower, good moldability is obtained. The glass transition temperature of the acrylic copolymer (f) is determined by the composition ratio of other monomers copolymerized with the hydroxyl group-containing monomer and acidic functional group-containing monomer.

<Isocyanate curing agent>
The isocyanate curing agent (g) reacts with a hydroxyl group which is a crosslinkable functional group in the acrylic copolymer (f) having a hydroxyl group described above to form a crosslinked cured resin layer. The blending ratio of the acrylic copolymer (f) and the isocyanate curing agent (g) in the coating material for forming the hard coat layer is 100 parts by mass of the acrylic copolymer (A) having a hydroxyl group of the present invention ( The ratio of the isocyanate group in the isocyanate curing agent (g) to the hydroxyl group in the acrylic copolymer (f) is NCO / OH = 1/2 to 3/1 with respect to the solid content). preferable. When the isocyanate group is 1 mol or more with respect to 2 mol of the hydroxyl group, the crosslinking reaction of the acrylic copolymer (f) and the isocyanate curing agent (g) proceeds, and cannot be obtained with a simple thermoplastic acrylic extruded film. An acrylic resin layer having good scratch resistance and wear resistance can be obtained. When the isocyanate group is 3 mol or less with respect to 1 mol of the hydroxyl group, excessive cross-linking reaction is suppressed and deep drawing can be performed.

  It is important that the isocyanate-based curing agent (g) has two or more isocyanate groups in one molecule, and examples thereof include aromatic isocyanates, aliphatic isocyanates, and alicyclic isocyanates. Especially, it is preferable to use an aliphatic isocyanate type hardening | curing agent from the point which prevents the yellowing of a shaping decoration sheet. One type of isocyanate curing agent (g) may be used, or two or more curing agents may be used in combination. Moreover, you may use the hardening | curing agent which reacts with another hydroxyl group in the range which does not affect the physical property of the decorating sheet of this invention.

  As aromatic isocyanate, 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate Isocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanatebenzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 "- And triphenylmethane triisocyanate.

  Examples of the aliphatic isocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, Examples include 2,4,4-trimethylhexamethylene diisocyanate.

  As alicyclic isocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2 , 4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanatomethyl) cyclohexane, and the like.

  These isocyanate-based curing agents further include adducts of the above isocyanates and polyol compounds such as trimethylolpropane, burettes and isocyanurates of the above isocyanates, and further the above isocyanates and known polyether polyols, polyester polyols, acrylic polyols, It is preferably used as an adduct with polybutadiene polyol, polyisoprene polyol or the like.

  Among these isocyanate curing agents (g), a low yellowing type aliphatic or alicyclic isocyanate is preferable from the viewpoint of design, and an adduct is preferable from the viewpoint of the film strength of the cured film. More specifically, an adduct of hexamethylene diisocyanate (HDI) and an adduct of 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI) are preferred. Moreover, these mixtures are also used suitably.

  Moreover, in this invention, you may use a blocked isocyanate hardening | curing agent from a viewpoint of the storage stability of the coating material for hard-coat layer formation. As the blocked isocyanate curing agent, those obtained by blocking the above-mentioned non-blocked isocyanate curing agent with various blocking agents are used, and as the blocking agent, those that deviate at a relatively low temperature of about 80 ° C. to 120 ° C. preferable. When using a non-blocked isocyanate curing agent, the acrylic copolymer (f) having a hydroxyl group and the isocyanate curing agent (g) are packaged separately and mixed immediately before use. Is preferably used.

<Paint for forming hard coat layer>
The paint contains a solvent in addition to the acrylic copolymer (f) and the isocyanate curing agent (g). The kind of the solvent is not particularly limited, and a known one can be used, but an organic solvent is preferable from the viewpoint of solubility of the acrylic copolymer (f) and the isocyanate curing agent (g).
Examples of the organic solvent include aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate, butyl acetate and cellosolve acetate; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone.

When a plastic having poor solvent resistance (for example, polycarbonate) is used as the substrate layer, the solvent is at least alcohol, methyl isobutyl ketone (hereinafter also referred to as MIBK), or propylene glycol monomethyl ether acetate (hereinafter also referred to as PGMAC). It is preferable to include one type. The alcohol can be used if the isocyanate curing agent (g) is a blocked isocyanate, and even if it is a non-blocked isocyanate, it can be used if it is a higher alcohol having poor reactivity with an isocyanate group.
When these solvents are used, the surface of the base material layer is not whitened when the paint of the present invention is applied to the polycarbonate base material, and the polycarbonate base material warps during drying and curing after coating. There is nothing.
When using MIBK or / and PGMAC, it is preferable that the ratio of MIBK and PGMAC is MIBK / PGMAC = 100 / 0-0 / 100 in 100 mass% of both. And in 100 mass% of organic solvents to be used, it is preferable that MIBK and PGMAC are 70 mass% or more in total.
Even when polycarbonate or the like is used as the base material layer, a solvent other than MIBK or PGMAC can be used if the coating is not applied directly to the base material layer. That is, after the paint is separately applied on the peelable sheet, the solvent is volatilized, the acrylic copolymer (f) having a hydroxyl group and the isocyanate curing agent (g) are cured, and a hard coat layer is formed. When the hard coat layer is laminated on the base material layer using the adhesive layer, the degree of freedom in selecting the solvent contained in the paint is widened.

  It is preferable to use a solvent having a boiling point of 50 ° C to 200 ° C. When the boiling point is lower than 50 ° C., the solvent tends to volatilize when applying the coating material, which is a curable composition, to the base film, and the solid content becomes high, making it difficult to apply with a uniform film thickness. When the boiling point is higher than 200 ° C., it is difficult to dry the solvent. Two or more solvents may be used.

  In the present invention, an additive such as polyol may be added to improve moldability.

Various additives and other resins can be appropriately blended in the hard coat layer of the present invention as long as the effects of the present invention are not impaired. Here, examples of the additive include an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, a flame retardant, a colorant, and a surface conditioner. Examples of the other resin include methyl methacrylate-maleic anhydride copolymer.

A surface conditioner or the like may be added to the paint for the purpose of more effectively preventing surface defects in the hard coat layer of the present invention. Examples of the surface conditioner include BYK-300, BYK-315, and BYK-320 manufactured by BYK. These surface conditioners are used in an amount of 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the solid content of the paint.

(Antioxidant)
As the antioxidant, various commercially available products can be applied, and various types such as monophenol type, bisphenol type, polymer type phenol type, sulfur type and phosphite type can be exemplified.
Examples of monophenols include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, and the like. Examples of bisphenols include 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2′-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4 '-Thiobis- (3-methyl-6-tert-butylphenol), 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenol), 3,9-bis [{1,1-dimethyl- 2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl} 2,4,9,10-tetraoxaspiro] 5,5-undecane and the like can be exemplified.

  Examples of the high molecular phenolic compound include 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris ( 3,5-di-tert-butyl-4-bidoxybenzyl) benzene, tetrakis- {methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate} methane, bis {(3,3'-bis-4'-hydroxy-3'-tert-butylphenyl) butyric acid} glycol ester, 1,3,5-tris (3 ', 5'-di-tert-butyl- Examples include 4'-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione, tocopherol (vitamin E) and the like.

  Examples of sulfur-based compounds include dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiopropionate.

Examples of the phosphite system include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, Crick neopentanetetrayl bis (octadecyl phosphite), tris (mono and / or di) phenyl phosphite, diisodecyl pentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Oxide, 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10 -Dihydro-9-oxa-10-fo Phaphenanthrene, cyclic neopentanetetraylbis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-tert-methylphenyl) phosphite, 2 , 2-methylenebis (4,6-tert-butylphenyl) octyl phosphite.
The said antioxidant can be used individually by 1 type or in combination of 2 or more types.

In the present invention, phenolic and phosphite-based antioxidants such as high-molecular-weight phenols are preferred in view of the effect of antioxidants, thermal stability, economy, etc. Among them, phosphite-based ones having excellent thermal decomposition resistance are preferred. Antioxidants are more preferred.
The addition amount of the antioxidant is in the range of 0.001 to 0.5 parts by mass with respect to 100 parts by mass of the resin composition constituting the acrylic resin layer (A), and 0.05 to 0.3 It is preferable to add part by mass.

(UV absorber)
As the ultraviolet absorber, various commercially available products can be applied, and various types such as benzophenone, benzotriazole, triazine, and salicylic acid ester can be exemplified.
Examples of the benzophenone ultraviolet absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-n-dodecyl. Oxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2,4 Examples include -dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone.

Benzotriazole-based UV absorbers include hydroxyphenyl-substituted benzotriazole compounds, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-butylphenyl) benzotriazole 2- (2-hydroxy-3,5-dimethylphenyl) benzotriazole, 2- (2-methyl-4-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-3-methyl-5-t-butylphenyl) ) Benzotriazole, 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole and the like.
Examples of the triazine ultraviolet absorber include 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol, 2- (4 , 6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyloxy) phenol and the like.
Examples of salicylic acid esters include phenyl salicylate and p-octylphenyl salicylate.
The said ultraviolet absorber can be used individually by 1 type or in combination of 2 or more types.
The addition amount of the ultraviolet absorber is in the range of 0.3 to 5.0 parts by mass with respect to 100 parts by mass of the resin composition constituting the acrylic resin layer (A), and 0.5 to 2.0. It is preferable to add part by mass.

(Light stabilizer)
In addition to the above UV absorbers, hindered amine light stabilizers can be suitably used as light stabilizers that impart weather resistance. The hindered amine light stabilizer does not absorb ultraviolet rays like the ultraviolet absorber, but exhibits a remarkable synergistic effect when used together with the ultraviolet absorber.

(Hindered amine light stabilizer)
Examples of hindered amine light stabilizers include dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1,1 , 3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {{2, 2,6,6-tetramethyl-4-piperidyl} imino}], N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2, 6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (3 , 5-Di-tert-4- Mud alkoxybenzylacetic) -2-n-butyl malonic acid bis (1,2,2,6,6-pentamethyl-4-piperidyl), and others.
The addition amount of the hindered amine light stabilizer is in the range of 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the resin composition constituting the acrylic resin layer (f), and 0.05 to 0 It is preferable to add 3 parts by mass.

<Decoration sheet base material layer>
The decorative sheet base layer plays a role of supporting the hard coat layer and other colored layers and adhesive layers described later.
The decorative sheet base material layer is not particularly limited as long as it is a film that plays a role as a support, and known ones can be used. For example, polyethylene film, polypropylene film, polyester film, polycarbonate film, polymethyl methacrylate film, polyamide film, polyimide film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polystyrene film, polyacrylonitrile film, aluminum foil, paper The thing etc. were mentioned and what laminated | stacked 1 type or multiple types can be used. In particular, from the viewpoint of transparency and moldability, a polyester film, a polycarbonate film, and a polymethyl methacrylate film are preferable. These films can also be used alone or in a laminate of a plurality of types. For example, PMMA / PC films in which polymethyl methacrylate (PMMA) is co-extruded on polycarbonate (PC), polycarbonate A film in which a film and a polyester film are laminated with an adhesive can also be used. Polycarbonate film has good moldability, polyester film has good solvent resistance (for organic solvents, sunscreen cream, etc.), and polymethylmethacrylate film has good hardness. The combination can be appropriately selected and used.
In addition, regarding the total light transmittance and the diffuse transmittance, the base material layer is preferably 40% or more of the total light transmittance and 70% or less of the diffuse transmittance similarly to the hard coat layer. This is not the case with the configuration provided between the hard coat layer and the base material layer.

<Adhesive layer>
The decorative sheet of the present invention can be further provided with an adhesive layer and a colored layer as described later. As described above, the adhesive layer is provided between the hard coat layer and the base material layer, and is used to bond the hard coat layer and the base material layer together. Is also used to bond various layers.
For example, a 1st base material layer and a 2nd base material layer can be bonded together using an adhesive bond layer. Or an adhesive layer can be provided in the opposite side to the hard-coat layer side of a base material layer, and to-be-decorated bodies, such as a decorative sheet and a resin molding, can also be bonded together.

Adhesives constituting the adhesive layer are not particularly limited, and known ones can be used, for example, thermosetting adhesives, pressure sensitive adhesives, hot melt adhesives, acrylic adhesives, urethane adhesives. , Hot melt pressure-sensitive adhesives, and the like. These can be used alone or in combination of two or more.
The components constituting these adhesives are not particularly limited. For example, polyester resin, poly (meth) acrylate resin, polyurethane resin, polyether resin, polyamide resin, polyimide resin, polyethylene resin, polystyrene resin, polypropylene resin, ethylene-acetic acid Examples include vinyl resin, polyvinyl alcohol resin, epoxy resin, silicone resin, phenol resin, styrene-butadiene rubber, nitrile rubber, and natural rubber. The (meth) acrylic acid ester copolymer (a) of the present invention and aziridine It is also possible to use a composition containing the system curing agent (b), and it can be used alone or in combination of two or more.

  A method for providing the adhesive layer will be described. The adhesive layer can be prepared by directly applying and drying an adhesive containing a solvent to the base layer or hard coat layer, or by softening an adhesive not containing a solvent with heat to form the base layer or hard coat (HC ), And a method of coating and cooling, or applying an adhesive containing or not containing a solvent on the peelable sheet by the above method, and providing the adhesive sheet between the objects to be bonded. It can be provided by a method of sandwiching an adhesive sheet. An aging treatment may be further performed after the adhesive layer is provided. In addition, the thickness of the adhesive layer is not particularly limited, and can be set by arbitrarily setting the thickness that can secure the adhesive force, but in the range of 1 to 200 μm from the balance between the adhesive force and durability. Is preferred.

  As a method for applying the adhesive, known methods can be used, and specific examples include comma coating, gravure coating, reverse coating, roll coating, lip coating, and spray coating.

<Colored layer>
The decorative sheet of the present invention may further be provided with a colored layer. The colored layer is laminated to give the decorative sheet a design, and when it is used as a decorative molded body such as between the hard coat layer and the base material layer, the hard coat layer of the base material layer and the other surface. Any position that does not become the outermost layer can be provided freely. In addition, the term “coloring” as used in the present invention includes various decorations such as a picture / design, a metallic tone, a character, and a pattern in addition to a single color, and a plurality of different colored layers may be laminated.

  A method for obtaining a colored layer will be described. The colored layer is obtained by applying a colored paint to the base material layer and drying it, the method by which the base material layer can be applied, dried and aged, the method by which the base material layer is applied and irradiated with light, the base material Examples thereof include a method obtained by printing on a layer and drying, a method obtainable by printing on a substrate layer and performing light irradiation, and a method obtainable by vapor-depositing a metal on the substrate layer. The thickness of the colored layer is not particularly limited as long as the intended color, pattern or the like can be recognized, but is preferably 500 μm or less from the viewpoint of moldability.

  As a method of providing the colored layer on the substrate, a known method can be used. Specifically, comma coating, gravure coating, reverse coating, roll coating, lip coating, spray coating, silk screen printing, offset Examples thereof include printing, gravure printing, ink jet printing, and vapor deposition.

  The decorative sheet of the present invention can produce a decorative molded body by various molding methods such as vacuum molding, pressure molding, TOM molding, injection molding, in-mold molding, press molding, and stamping molding.

  As a method for providing a protective film on the decorative sheet of the present invention, when a hard coat layer or an adhesive layer is provided by applying and drying a coating liquid on a base material layer, a method of attaching a protective film, or protection Examples include a method of applying a coating solution on a film, drying, aging as necessary, providing a hard coat layer and an adhesive layer, and then bonding the substrate layer and a decorative sheet. In addition, when providing a hard-coat layer on a protective film previously, you may bond together using an adhesive agent as needed.

<Aspect of decorative sheet>
There are various modes for the decorative sheet provided with a hard coat layer to which the protective film for decorative molding is attached. A specific example of this aspect will be described with reference to the drawings. The figures shown in FIGS. 1 to 8 are views after peeling off the anti-blocking protective film to be applied when the hard coat is applied, and the decorative molding protective film is provided on the anti-blocking protective film. In some cases, it is peeled off after injection molding.
In FIG. 5, the decorating sheet | seat 201 which consists of a 2 layer structure of the hard-coat layer 10 and the base material layer 1 is shown.
In FIG. 6, the decorating sheet 202 which consists of a laminated body of the hard-coat layer 10, the 2nd 1st base material layer 1a, and the 2nd base material layer 1b is shown. The 1st base material layer 1a and the 2nd base material layer 1b can be provided by co-extrusion, for example.
FIG. 7 shows a decorative sheet 203 in which the adhesive layer 1 is sandwiched between the hard coat layer 10 and the base material layer 1.
FIG. 8 shows a decorative sheet 204 having the hard coat layer 10 and the base material layer 1 and having the colored layer 3 on the non-opposing side of the base material layer 1 to the hard coat layer 10.
FIG. 9 shows a decorative sheet 205 having a hard coat layer 10, a base material layer 1, and a colored layer 3, and comprising a laminate in which the colored layer 1 is sandwiched between the hard coat layer 10 and the base material layer 1. Indicates.
FIG. 10 includes a hard coat layer 10, a base material layer 1, an adhesive layer 2, and a colored layer 1, and the adhesive layer 2 is sandwiched between the hard coat layer 10 and the base material layer 1. The decoration sheet 206 which has the colored layer 3 in the non-opposing surface side with 1 adhesive bond layer 2 is shown.
FIG. 11 includes a hard coat layer 10, a first base layer 1a, a second base layer 1b, a first adhesive layer 2a, and a second adhesive layer 2b. The first adhesive layer 2a Shows the decorative sheet 207 in which the second adhesive layer 2a is located between the first base material layer 1a and the second base material layer 1b, between the hard coat layer 10 and the first base material layer 1a. .

[Decorative molding]
The decorative molded body is a decorated body such as a molded body whose surface is covered with the decorative sheet, and the material of the decorated body to be coated is not particularly limited, and a known material is used. Can do.
Examples of materials that can be used as decorated objects include wood, paper, metal, plastic, fiber reinforced plastic, rubber, glass, minerals, clay, etc., one or a combination of two or more Can do.
Examples of plastics include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, epoxy resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (AS) resin, poly (meth) acrylate, polycarbonate, polyamide, polyimide , Polyphenylene ether, polyphenylene sulfide, polyester, polytetrafluoroethylene and the like, and one kind or a combination of two or more kinds can be used.
Examples of the fiber reinforced plastic include carbon fiber reinforced plastic, glass fiber reinforced plastic, aramid fiber reinforced plastic, polyethylene fiber reinforced plastic, and the like, which can be used alone or in combination of two or more.
Examples of metals include hot rolled steel, cold rolled steel, galvanized steel, electrogalvanized steel, hot dip galvanized steel, alloyed hot dip galvanized steel, zinc alloy plated steel, copper plated steel, zinc-nickel plated steel, Zinc-aluminum-plated steel, iron-galvanized steel, aluminized steel, aluminum-galvanized steel, tin-plated steel, aluminum, stainless steel, copper, aluminum alloy, electromagnetic steel, etc. Can be used in combination. In addition, a protective layer or the like may be provided on the surface of the metal.

  There is no limitation in particular in the method of integrating with the decorating sheet of this invention, and a to-be-decorated body, It can integrate with a well-known integration method. As an integration method, for example, insert molding, in-mold molding, vacuum molding, compressed air molding, TOM molding, press molding, or the like can be used.

  After pre-molding the protective film-added decorative sheet into a desired shape, plastic or fiber-reinforced plastic is injection-molded so that the hard coat layer side is the outermost layer to obtain a decorative molded body. Alternatively, a hard-coating layer is obtained by obtaining a molded body from plastic, fiber-reinforced plastic, or metal, and forming a protective film-added decorative sheet on the surface of the molded body, or a preformed body that has been pre-shaped into a desired shape. Although it can be attached so that the side is the outermost layer, the protective film for decorative sheets of the present invention is particularly effective for insert molding in which foreign matter is pressed into the mold with a large pressure on the hard coat surface, This is in-mold molding and press molding, and can prevent unevenness caused by foreign matter.

  In order to protect the appearance defects that may occur in each process such as coating, drying, aging, and molding integration, the protective film of the present invention is provided on the hard coat layer of the decorative sheet, and the resulting decorative molded body is used. In the case where the protective film is applied, the protective film peels off.

When manufacturing a decorative molded body using a protective film-added decorative sheet, it is preferable to include the following steps.
(Step 1) Step of shaping the protective film-added decorative sheet,
(Step 2) A step of injection molding the shaped protective film-added decorative sheet,
(Step 3) A step of removing the protective film from the injection-molded protective film-added decorative sheet.

(Step 1) Step of shaping the protective film-added decorative sheet,
The protective film-added decorative sheet is shaped (preliminarily formed) by a conventionally known molding method such as vacuum forming, vacuum / pressure forming, or pressure forming. At this time, the decorative sheet is heated to a temperature necessary for forming the base material. The temperature to be heated is appropriately selected depending on the substrate to be molded, but is about 80 to 180 ° C. Therefore, the protective film is required to have heat resistance to this step. Unnecessary parts of the decorative sheet with the molded protective film are trimmed and removed with a cutting blade such as a laser or Thomson blade. At this time, it plays a role in preventing ink and burrs from adhering to the hard coat surface. Is a protective film.

(Step 2) A step of injection-molding a resin to the shaped protective film-added decorative sheet,
Unnecessary portions of the molded protective film-added decorative sheet are trimmed and removed by a cutting blade such as a laser or a Thomson blade, and the decorative sheet of the portion provided in the molded body is inserted (inserted) into an injection molding machine. Depending on the application and performance, the resin to be injected can be polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyphthalamide (PAA), polyoxymethylene (POM), polymethyl methacrylate (PMMA), polypropylene (PP), It is selected from polybutylene terephthalate (PBT), polyamide (PA), etc., and used as an injection resin. The injection resin is appropriately selected depending on the injection resin in the range of 100 to 300 ° C. However, if there is a foreign matter on the hard coat surface of the molded body, it is pressed by the pressure of the injection resin to cause unevenness, which is called a dent. is there. This is because the protective film absorbs the pressure applied to the hard coat surface from the foreign matter at this time, and maintains the smoothness of the hard coat surface.

(Step 3) A step of removing the protective film from the injection-molded protective film-added decorative sheet.
When the injection molding is completed, the molded body having an excellent appearance on the hard coat surface can be obtained by taking out the molded body from the injection molding machine and removing the protective film from the molded body.

Hereinafter, the embodiment of the present invention will be described in more detail with reference to examples and comparative examples. It should be noted that the present invention is not limited to only these examples in accordance with the detailed description.

(Adjustment of adhesives and adhesives)
The adjustment method of the adhesive agent and adhesive used for preparation of the protective film for decorating sheets is demonstrated.

(Adhesive A)
TM-K76 (main agent) manufactured by Toyo Morton: CAT-RT85 (curing agent) was mixed at a ratio of 100: 7 to prepare an adhesive with a solid content of 30%.

(Adhesive a)
The pressure-sensitive adhesive a was synthesized and adjusted by the following method.
In a reaction vessel (hereinafter simply referred to as “reaction vessel”) equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 70 parts of n-butyl acrylate, 20 parts of methyl acrylate, 2-ethyl After charging 4 parts of hexyl acrylate, 6 parts of acrylic acid, 72 parts of ethyl acetate and 0.13 part of 2,2′-azobis (2-methylbutyronitrile), the air in this reaction vessel was replaced with nitrogen gas The reaction solution was reacted at reflux temperature for 8 hours in a nitrogen atmosphere with stirring. After completion of the reaction, diluted with ethyl acetate, to give a nonvolatile concentration of about 30%, of the weight average molecular weight Mw105 ten thousand a solution of acrylic copolymer a _1.
Charge 100 parts of toluene in the reaction vessel, charge 95 parts of n-butyl methacrylate and 5 parts of N, N-dimethylaminoethyl methacrylate in the dropping device, and replace the air in the reaction vessel with nitrogen gas, then stir. Then, the reaction solution was reacted at reflux temperature for 8 hours after dropwise addition in 1 hour in a nitrogen atmosphere. After completion of the reaction, diluted with ethyl acetate, nonvolatile concentration of about 30% to obtain a solution of acrylic copolymer a ₂ weight-average molecular weight Mw5 250,000.
25 parts by weight of acrylic copolymer solution _{a 1} to 75 parts by weight acrylic copolymer solution _{a 2,} N as epoxy cross-linking agent, N, N ', N'- tetraglycidyl -m- xylylenediamine 0.021 parts Was added and stirred uniformly to obtain an adhesive a.

(Adhesive b)
The adhesive b for affixing on the hard-coat surface of the decorating sheet used for the Example and the comparative example was synthesize | combined and mix | blended as follows.
2-ethylhexyl acrylate / butyl acrylate / vinyl acetate / acrylic acid / 2hydroxyethyl acrylate = 55.0 / 33.5 / 10.0 / 0.5 / 1.0 in a solvent of toluene / ethyl acetate = 1/1 (Weight ratio) was copolymerized to obtain an acrylic copolymer solution having a weight average molecular weight (hereinafter referred to as Mw) of 550,000.
20 parts by weight of cellulose acetate butyrate resin CAB551-0.2 (manufactured by Eastman Kodak Co., Ltd.) is blended with the acrylic copolymer (100 parts by weight of solid content), and the base solution (solid content) of the adhesive layer b 40%).

(Protective film base for decorative sheet)
The following were used for the substrate.
CR1012: Polymethylpentene trilayer film 150 μm, Mitsui Chemicals Tosero X-44b: Polymethylpentene monolayer film 50 μm, Mitsui Chemicals Tosero FT3PE: Easily molded polyethylene terephthalate 25 μm, Teijin AG306X: Polypropylene film 200 μm, Idemitsu Unitech BS -50: Polybutylene terephthalate 25 μm, Aussie film S-25: Polyethylene terephthalate 25 μm, Unitika S-12: Polyethylene terephthalate 12 μm, Unitika DUs605CER: Non-yellowing urethane film 100 μm, Seadam
DUS202: non-yellowing urethane film 200 μm, made by Seadam
MH-14: Polypropylene self-adhesive film 50 μm, Hayashi Koji Co., Ltd. DNFC1312-80WS: Vinyl chloride film 80 μm, Riken Technos 100Q16CK: Releasable olefin film 200 μm, Toray

(Create a protective film for decorative sheets)
Protective film for decorative sheet (Example 1)
PET film separator 50 μm treated with release silicone by compounding 0.1 part by weight of aziridine compound Chemitite PZ-33 (manufactured by Nippon Shokubai Co., Ltd.) as a curing agent with respect to the main component (solid content 100 parts by weight) of adhesive b (SP-PET01-50BU: manufactured by Mitsui Chemicals Tosero) was applied so that the coating amount was 30 g / m ² (dry), and dried at 90 ° C. for 1 minute.
CR1012 was attached by roll lamination as a base material.

(Examples 2 to 5, Comparative Examples 1, 2, and 4)
Except having changed CR1012 of Example 1 into the base material 1 of Table 1, it carried out similarly to Example 1, and obtained the protective film for decorative sheets of Examples 2-5 and Comparative Examples 1, 2, and 4.

(Example 6)
The untreated surfaces of X-44b (base material 1) and FT3PE (base material 2) were each subjected to corona at a table speed of 3 m / min and an output of 0.25 KW using a sheet-fed corona treatment machine manufactured by Kasuga Electric Co., Ltd. Processed. Wako Pure Chemical Industries, Ltd. Wetting Index Standard Solution No. A cotton swab was dipped in 35, and a standard solution was applied to the corona-treated substrate surface with a cotton swab to confirm that there was no repelling.
Next, 30 μm (dry) of adhesive A was applied on the corona-treated surface of FT3PE (base material 2) by a bar coater, dried at 80 ° C. for 1 minute, and then the corona-treated surface of X-44b (base material 1) was coated. Roll lamination was performed to obtain a multilayer substrate.
Then, 0.1 part by weight of aziridine compound Chemitite PZ-33 (manufactured by Nippon Shokubai Co., Ltd.) as a curing agent was blended with the main component of the adhesive b (solid content: 100 parts by weight), and a release silicone-treated PET film. After applying to a separator 50 μm (SP-PET01-50BU: manufactured by Mitsui Chemicals, Inc.) so that the coating amount is 30 μm (dry) and drying at 90 ° C. for 1 minute, X-44b (base material 1) and FT3PE The multilayer substrate bonded with (Substrate 2) was roll-laminated to obtain a protective film. The protective film was aged at room temperature for 1 week.

(Examples 7 to 17, Comparative Examples 5 to 7)
For the decorative sheets of Examples 7 to 17 and Comparative Examples 5 to 7, in the same manner as in Example 6, except that the base material 1, base material 2, and adhesive of Example 6 were changed according to the description in Table 1. A protective film was obtained.
(Comparative Example 3)
In Comparative Example 3, a commercially available self-adhesive film MH-14 50 μm (manufactured by Hayashi Koji Co., Ltd.) was used as it was as a protective film for a decorative sheet.

(Measurement of storage modulus)
The storage elastic modulus was measured by cutting a test piece having a length of 15 mm and a width of 5 mm from the base film and the protective film, and using a dynamic viscoelasticity measuring device DVA-200 (manufactured by IT Measurement Control Co., Ltd.), load cell: 600 gf , Temperature rising rate: 5 ° C./min, frequency: change in storage elastic modulus (E ′), loss elastic modulus (E ″), and loss tangent (tan δ) in a temperature range of 25 to 200 ° C. when tensioned at 10 Hz And the storage elastic modulus (E ′) at 80 ° C. and 160 ° C. was extracted.

Table 1 shows the constitution of the protective film, the base film used, and the storage elastic modulus of the entire protective film.

(Creating a decorative sheet)
Next, a method for creating a decorative sheet will be described. As the decorative sheet, a polycarbonate film provided with a hard coat paint by the following method was used.

(Synthesis of hard coat resin)
The hard coat resin was synthesized as follows.
Synthesis Example A “Acrylic Copolymer A Solution”
A four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen introducing tube was charged with 150 parts of methyl isobutyl ketone (MIBK) and heated with stirring in a nitrogen atmosphere. When the temperature in the flask reaches 74 ° C., this temperature is maintained as the synthesis temperature, 30 parts of methyl methacrylate, 61.21 parts of cyclohexyl methacrylate, 31.33 parts of n-butyl methacrylate, 0.77 parts of methacrylic acid, Monomer solution prepared by mixing 1.79 parts of 2-hydroxyethyl methacrylate, 1 part of vancyl FA-711MM (manufactured by Hitachi Chemical Co., Ltd., methacrylate-pentamethylpiperidinyl) and 0.07 part of azobisisobutyronitrile. Was added dropwise over 2 hours. The reaction was continued by adding 0.02 parts of azobisisobutyronitrile every hour from 1 hour after the completion of the monomer dropping, and the reaction was continued until the unreacted monomer in the solution was 1% or less. When the unreacted monomer was 1% or less, the reaction was terminated by cooling to obtain an acrylic copolymer A-1 solution having a solid content of about 40%. Acrylic copolymer A-1 has a glass transition temperature of 70 ° C., an acid value of 5 mg KOH / g, a hydroxyl value of 25 mg KOH / g, a number average molecular weight of 70,000, a mass average molecular weight of 300,000, and a polydispersity. : 4.1.
Solid content, glass transition temperature (Tg), acid value, hydroxyl value, number average molecular weight (Mn), mass average molecular weight (Mw), and polydispersity (Mw / Mn) were measured by the methods described below.

<Measurement of solid content>
The mass of an aluminum pan with a lid having a diameter of 55 mm and a depth of 15 mm is measured to 4 digits after the decimal point. About 1.5 g of the resin solution is collected in an aluminum dish, and the lid is immediately covered and the mass is measured quickly and accurately. With the lid removed, place in an oven at 150 ° C. for 10 minutes to dry. After cooling to room temperature, the mass of the aluminum pan and the lid is measured, and the solid content is calculated by the following formula.
Solid content (%) = (mass after drying−mass of aluminum dish) ÷ (mass before drying−mass of aluminum dish) × 100

<< Measurement of glass transition temperature (Tg) >>
An aluminum pan containing a sample of about 10 mg of resin having a solid content of 100% dried and an aluminum pan containing no sample was set in a differential scanning calorimetry (DSC) apparatus, and this was placed in a nitrogen stream. Liquid nitrogen is used to cool the predicted glass transition temperature to a temperature of minus 50 ° C., and then the temperature is increased to a temperature of 10 ° C./min from the predicted glass transition temperature to a temperature of plus 50 ° C. Plot the DSC curve. The slope of the DSC curve on the low temperature side (the DSC curve portion in the temperature region where no transition or reaction occurs in the test piece) is extended to the high temperature side, and the slope of the step change portion of the glass transition is maximized. From the intersection with the tangent drawn at such a point, the extrapolated glass transition start temperature (Tig) was determined, and this was taken as the glass transition temperature.

<Measurement of acid value (AV)>
About 1 g of the resin solution is accurately weighed into an Erlenmeyer flask with a stopper, and 50 mL of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. To this is added phenolphthalein reagent as an indicator and held for 30 seconds. Thereafter, the solution is titrated with a 0.1 mol / L alcoholic potassium hydroxide solution until the solution becomes light red. The acid value was determined by the following formula. The acid value is a numerical value of the dry state of the resin.
Acid value (mgKOH / g) = (a × F × 56.1 × 0.1) / S
S: Amount of sample collected x (solid content of sample / 100) (g)
a: Titration volume of 0.1 mol / L alcoholic potassium hydroxide solution (mL)
F: Potency of 0.1 mol / L alcoholic potassium hydroxide solution

<< Measurement of hydroxyl value (OHV) >>
About 1 g of the resin solution is accurately weighed into an Erlenmeyer flask with a stopper, and 50 mL of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. Further, add exactly 5 mL of an acetylating agent (a solution in which 25 g of acetic anhydride is dissolved in pyridine to make a volume of 100 mL), heat to 100 ° C. and stir for about 1 hour. To this, phenolphthalein reagent is added as an indicator and lasts for 30 seconds. Thereafter, the solution is titrated with a 0.5 mol / L alcoholic potassium hydroxide solution until the solution becomes light red. Separately, as a blank test, a solution obtained by adding an acetylating agent only to a toluene / ethanol mixed solution and heating at 100 ° C. for 1 hour is titrated with a 0.5 mol / L alcoholic potassium hydroxide solution. The hydroxyl value was determined by the following formula. The hydroxyl value was a numerical value of the dry state of the resin.
Hydroxyl value (mgKOH / g) = {(ba) × F × 56.1 × 0.5} / S + D
S: Amount of sample collected x (solid content of sample / 100) (g)
a: Titration volume of 0.5 mol / L alcoholic potassium hydroxide solution (mL)
b: Titration volume (mL) of 0.5 mol / L alcoholic potassium hydroxide solution in the blank experiment
F: titer of 0.5 mol / L alcoholic potassium hydroxide solution D: acid value (mgKOH / g)

<< Measurement of Number Average Molecular Weight (Mn) and Mass Average Molecular Weight (Mw) >>
The measurement was performed using a Shodex GPC-104 / 101 system manufactured by Showa Denko.
Column Shodex KF-805L + KF-803L + KF-802
Detector Differential refractometer (RI)
Column temperature 40 ° C
Eluent Tetrahydrofuran (THF)
Flow rate: 1.0 mL / min
Sample concentration: 0.2%
Standard sample for calibration curve TSK standard polystyrene The polydispersity was determined from the obtained Mn and Mw by the following formula.
Polydispersity = Mw / Mn
(Creation of hard coat paint)
15 parts by weight of Duranate “P301-75E” (manufactured by Asahi Kasei Chemicals Corporation, polyisocyanate of hexamethylene diisocyanate) as a polyisocyanate compound and 100 parts by weight of acrylic copolymer (A) as a leveling agent, BYK-300 ( Bic Chemie Japan Co., Ltd.), 0.8 parts by weight, and further diluted with methyl isobutyl ketone to a solid content of 30% to prepare a hard coat paint (HC-1).

(Hard coat coating)
A hard coat paint (HC-1) was applied to one side of a 300 μm thick, A4-sized polycarbonate base material (Teijin Hanlite 0.3t 2151) so that the film thickness after drying was 20 μm. The solvent was volatilized by drying in an oven at 0 ° C. for 1 minute. Next, it is left in a thermostatic chamber at 50 ° C. for 4 days to allow the reaction between the acrylic copolymer and the polyisocyanate compound to proceed (aging) to form a hard coat layer on the polycarbonate base material to obtain a decorative sheet. It was.
[Evaluation of protective film for decorative sheet]
The obtained protective film for decorative sheet was evaluated by the following method. The results are shown in Table 2.

(Heat resistance during printing)
The decorative molding protective film is pasted on the hard coat of the decorative sheet in a sample width of 25 mm and at 23 ° C. and 50% atmosphere, and a 2 kg roll is pressure-bonded according to JIS0237 to obtain a decorative molded protective film-added decorative sheet. It was.
After 20 minutes, the decorative sheet with a decorative molded protective film was placed in an oven at 80 ° C. and left for 30 minutes to observe the appearance.
○: No foaming.
Δ: Some foaming is observed.
X: Foaming is observed on the entire surface.

≪Evaluation of heat resistance and moldability during molding≫
The protective film cut to A4 size was roll-laminated on the hard coat surface of the decorative sheet cut to A4 size and left for 20 minutes to obtain a protective film-added decorative sheet.
A vacuum / pneumatic molding machine TFH-0121 manufactured by Asano Laboratory was used for moldability evaluation.
The protective film-added decorative sheet was set so that the molding die was placed in the die frame, and the protective film faced upward on the frame. As the molding die, a deep drawing molding die having a tray shape with a size of 80 mm square, a rising edge of 10 mm, and a corner portion of R = 3 mm was used.
Continue heating until the surface temperature of the decorative sheet reaches 160 ° C on the heating plate at the top of the chamber. When the decorative sheet is heat softened, 0.9MPa of compressed air is sent from the hole in the upper heating plate, and a protective film is added. The sheet is brought into close contact with the mold, vacuumed from the lower part of the mold, molded, cooled, and the molded product is taken out from the mold. About the obtained protective film for decorative molding, the external appearance (heat resistance and moldability) was evaluated according to the following criteria.
(Heat resistance during molding)
○: No foaming.
Δ: Some foaming is observed.
X: Foaming is observed on the entire surface.
(Formability)
A: No wrinkles or tears.
○: There is no wrinkle or tearing, but some floats are seen.
Δ: Wrinkles and tears are seen in 10% of the total.
X: Wrinkles and tears are observed in 50% or more of the whole.

(Injection molding)
Protective film for decorative molding On the protective film of the decorative sheet, assuming a burr generated by trimming, use a white oily marker (Pentel White X100W-MD) so that the thickness is 3 to 6 μm in 5 mm square. Marked. The thickness was measured and confirmed using a Nikon Digimicro.
It is set in a mold, pre-dried at 100 ° C. for 4 hours using ABS / PC alloy resin “Excelloy CK50 (trade name)” manufactured by Techno Polymer Co., Ltd., and then PNX-60 hydraulic manufactured by Nissei Plastic Industry. A thermoplastic resin substrate was injection molded under the conditions of a cylinder temperature of 300 ° C., a mold temperature of 80 ° C., an injection speed of 250 mm / sec, and a holding pressure of 55 MPa using a type injection molding machine. As the mold, a mold matched to the mold formed by vacuum forming was used.

(Evaluation of heat resistance, protective film peelability, dent, smoothness, and flow during injection molding)
Regarding the heat resistance after the injection molding and the peelability of the protective film, the molded product was taken out after the injection molding, and the peelability of the protective film was evaluated as follows.
Pre-molding / post-molding peel force ratio = [0.3 m / min post-molding peel force] / [0.3 m / min initial peel force] was evaluated in the following range. For the peeling force, the protective film for molding was cut to a width of 25 mm on the molded body, and the adhesive force (90-degree peel, tensile speed 0.3 m / min) was measured in a tensile mode of a small desktop tester Eztest (manufactured by Shimadzu Corporation).
(Peelability after injection molding)
○: 1 to 3 times Δ: 3 to 5 times ×: 5 times or more In addition, the heat resistance was evaluated from the appearance before the protective film was peeled off from the molded body.
(Heat resistance during injection molding)
○: No foaming.
Δ: Some foaming is observed.
X: Foaming is observed on the entire surface.
The dent marks were evaluated based on whether or not the protective film was peeled off and the surface of the molded body was uneven with a mark marked with a white oily marker.
(Dent)
A: There is no unevenness.
○: There are slight irregularities, though not so conspicuous.
Δ: Slight unevenness is noticeable.
X: It is clearly depressed and uneven.
The smoothness evaluated the smoothness after peeling off a protective film.
(Smoothness)
◯: Smooth and glossy.
Δ: Slightly matte.
X: After film deformation or wrinkles.
The flow means that the film or adhesive adheres to the mold due to deformation / melting of the film or the adhesive sticks out from the side and soils the mold. When removing the molded body from the mold, the following criteria are used. evaluated.
(flow)
○: No film or adhesive is attached to the mold.
Δ: A small amount of film or adhesive is attached to the mold.
X: The film and the adhesive have adhered to the metal mold | die.

  A protective film with excellent heat resistance and moldability can be obtained by the protective film with a single layer film in Examples 1 to 5 and the protective film with a multilayer film in Examples 6 to 17, and the decorative sheet is hard. A decorative sheet excellent in the appearance of the coat layer could be obtained.

In Examples 6-8, two types of base materials were laminated with an adhesive, and in Examples 9-17, two types of base materials were laminated with an adhesive, but both gave good results.

A comparative example having no heat resistance and a low storage modulus exhibited foaming at the stage of printing and molding. Further, the self-adhesive film made of a commercially available polypropylene film of Comparative Example 3 was insufficient in heat resistance during molding and foamed, or the self-adhesive film itself contracted and partly peeled off from the decorative sheet.
In Comparative Examples 2, 3, 5, 6, and 7, the reason why the peelability after injection molding was poor is that the base material was melted and fused to the molded product.

101-103: Protective sheet for decorative sheet 11: Substrate layer 11a: First substrate layer 11b: Second substrate layer 12: Adhesive layer 12a: First adhesive layer 12b: Second adhesive Agent layer 13: Adhesive layer

201-207: Decorative sheet 10: Hard coat layer 1: Base layer 1a: First base layer 1b: Second base layer 2: Adhesive layer 2a: First adhesive layer 2b: Second Adhesive layer 3: colored layer

Claims (5)

A protective film for a decorative sheet having at least one base material layer and an adhesive layer, wherein the base material layer has a storage elastic modulus at 80 ° C. of 5 × 10 ⁷ to 1 × 10 ¹⁰ Pa and 160 ° C. A protective film for a decorative sheet having a storage elastic modulus of 5 × 10 ^{5 to} 6 × 10 ⁸ Pa. It is a protective film for a decorative sheet laminated in the order of at least a first base material layer, an adhesive layer, a second base material layer, and an adhesive layer,
The storage modulus at 80 ° C. of the first substrate layer is 5 × 10 ⁷ to 1 × 10 ¹⁰ Pa and the storage modulus at 160 ° C. is 1 × 10 ^{6 to} 5 × 10 ⁸ Pa, and the second substrate The protective film for decorative sheets is characterized in that the storage elastic modulus at 80 ° C. of the layer is 1 × 10 ⁸ to 1 × 10 ¹⁰ Pa and the storage elastic modulus at 160 ° C. is 1 × 10 ⁶ to 1 × 10 ⁹ Pa. . The storage elastic modulus at 80 ° C. of the whole decorative sheet protective film is 4 × 10 ⁷ to 1 × 10 ⁹ Pa and the storage elastic modulus at 160 ° C. is 1 × 10 ⁷ to 4 × 10 ⁸ Pa. The protective film for decorating sheets of Claim 1 or 2. A decorative film-added decorative sheet, wherein a decorative sheet is laminated on the outside of the pressure-sensitive adhesive layer of the protective film for a decorative sheet according to claim 1. A method for producing a decorative molded body characterized by having the following steps,
(Step 1) A step of shaping the protective film-added decorative sheet according to claim 4,
(Step 2) A step of injection-molding a resin to the shaped protective film-added decorative sheet,
(Step 3) A step of removing the protective film from the injection-molded protective film-added decorative sheet.