JP6577380B2 - Decorative molding film and decorative molded products - Google Patents

Description

The present invention relates to a decorative molding film and a decorative molded product.

The decorative molding film is used by being attached to a part of or the whole of a vehicle such as a bicycle, a motorcycle, an automobile, a bus, or a train, or a part thereof, a home appliance, or the like. As a structure of the film for decoration shaping | molding, the structure by which the film layer used as the support body of the film for decoration shaping | molding and the adhesive layer containing an adhesive composition was laminated | stacked is mentioned.

As a decorative molding film, for example, Patent Document 1 discloses a vacuum molding decoration having a base material layer, a decorative layer, a resin layer containing an acrylonitrile-butadiene-styrene copolymer, and an adhesive resin layer in this order. A film is disclosed. As an adhesive composition, for example, Patent Document 2 discloses an acrylic adhesive composition containing an acrylic polymer, a (meth) acrylic polymer having a predetermined weight average molecular weight, and a hydrogenated tackifying resin. ing.

JP 2012-213891 A JP 2012-67279 A

The decorative molding film has a high adhesive strength when the molding temperature at the time of application to a sticking object (base material) is increased. However, when the molding temperature is increased, there is a possibility that damage such as deformation is applied to the substrate. Moreover, when embossing was performed also on the decorative molding film side, there was a possibility that the previously formed embossed shape disappeared or deformed due to high temperature.

Furthermore, when the base material is a motorcycle or the like, it is assumed that the base material is used in various usage environments. Therefore, there has been a demand for a decorative molding film that hardly causes the decorative film to float, peel off, or the like not only at room temperature but also in an environment exceeding 80 ° C.

From the above, there has been a demand for a decorative molding film that follows a curved surface shape and has excellent adhesive strength and dimensional stability in a normal temperature and high temperature environment.

In general, general-purpose pressure-sensitive adhesives (acrylic pressure-sensitive adhesives) that exhibit adhesive strength at room temperature have a lower cohesive force than hot melt adhesives, and tend to further reduce the cohesive strength when the usage environment exceeds 40 ° C. is there. Therefore, when a general-purpose pressure-sensitive adhesive is used as a pressure-sensitive adhesive for a decorative molding film, there may be a problem that the decorative film peels off or floats from the end of the base material in a high temperature environment. On the other hand, when a hot melt adhesive is used as a pressure-sensitive adhesive for a decorative film, the decorative film adheres sufficiently to the edge of the base material when it is attached to a large base material such as a motorcycle. There were times when it was not. About this point, when this inventor examined, when sticking a film for decoration molding to a large-sized base material, it contacts at the end rather than the center part of the base material which a film for decoration molding contacts first. It has been found that the temperature of the end portion of the base material to be lowered may not be sufficient because the temperature is lowered.

Therefore, the present inventor has studied an acrylic pressure-sensitive adhesive that can be molded at a lower temperature than a hot melt adhesive. Acrylic pressure-sensitive adhesives often use a monomer having a low glass transition temperature as a main ingredient in order to develop an adhesive force at room temperature. In general, butyl acrylate and 2-ethylhexyl acrylate are often used in combination. However, according to the study of the present inventor, such an adhesive is used for adhesion under normal temperature and / or high temperature environment. The power was found to be insufficient. The present inventor has repeatedly studied, and when a copolymer of methyl acrylate and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms is used as the main component of the pressure-sensitive adhesive, in addition to the adhesive strength at room temperature, It has been found that a high cohesive force can be maintained even in a high temperature environment like a melt adhesive. Furthermore, when (meth) acrylic-acid alkylester was added as an additive of an adhesive, it discovered that adhesive force could be controlled according to the use environment of the film for decorating shaping | molding. And by making the content of the additive a predetermined amount, it is found that a decorative molding film capable of expressing excellent adhesive force and dimensional stability can be obtained not only at room temperature but also in a high temperature environment. The present invention has been completed. In the present specification, “room temperature” refers to a range of 23 ° C. ± 5 ° C.

The decorative molding film of the present invention is laminated in the order of a polyvinyl chloride film layer, a pressure-sensitive adhesive layer, and a separator, and the pressure-sensitive adhesive layer includes methyl acrylate and an alkyl acrylate ester containing a C 4 alkoxy group; And a (meth) acrylic acid alkyl ester having a glass transition temperature of 115 ° C. or lower and a weight average molecular weight of 5,000 to 100,000, Content is 1-40 weight part with respect to 100 weight part of said copolymers, It is characterized by the above-mentioned.

The glass transition temperature of the (meth) acrylic acid alkyl ester is preferably 40 ° C. or higher.

The content of the alkyl (meth) acrylate is preferably 19 to 25 parts by weight with respect to 100 parts by weight of the copolymer.

The copolymer preferably has a weight average molecular weight of 800,000 to 1,100,000.

The thickness of the pressure-sensitive adhesive layer is preferably 15 μm or more and 50 μm or less.

The decorative molded product of the present invention is a decorative molded product comprising a base material having a three-dimensional curved surface portion and a decorative film covering the three-dimensional curved surface portion, and the decorative film is a decorative film of the present invention. The separator is peeled from the decorative film, and is attached to the three-dimensional curved surface portion via the pressure-sensitive adhesive layer.

Since the decorative molding film of the present invention is flexible, it can follow the curved surface shape. Furthermore, the pressure-sensitive adhesive layer contains a copolymer of methyl acrylate as a main agent and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms, and a predetermined amount of a predetermined (meth) acrylic acid alkyl ester as an additive. By containing, a decorative molding film having excellent adhesive strength and dimensional stability under normal temperature and high temperature environment can be obtained. Since the decorative molded product of the present invention uses a decorative molding film having excellent adhesive strength and dimensional stability under normal temperature and high temperature environments, it is used not only at normal temperatures but also in environments exceeding 80 ° C. Even when it is done, the decorative film is unlikely to float or peel off.

The decorative molding film of the present invention is laminated in the order of a polyvinyl chloride film layer, a pressure-sensitive adhesive layer, and a separator, and the pressure-sensitive adhesive layer includes methyl acrylate and an alkyl acrylate ester containing a C 4 alkoxy group; And a (meth) acrylic acid alkyl ester having a glass transition temperature of 115 ° C. or lower and a weight average molecular weight of 5,000 to 100,000, Content is 1-40 weight part with respect to 100 weight part of said copolymers, It is characterized by the above-mentioned.

[Polyvinyl chloride film layer]
The polyvinyl chloride film layer is a film layer made of a polyvinyl chloride resin. The polyvinyl chloride film has good elongation and is difficult to break, so that it can be easily attached to a three-dimensional curved surface. Moreover, since it is excellent in printability and softens at a relatively low temperature (about 100 ° C.), it is suitable as a support for a decorative molding film. Although the said polyvinyl chloride-type resin is not specifically limited, For example, it is obtained by adding a plasticizer to polyvinyl chloride. The polyvinyl chloride having a polymerization degree of 800 to 1200 is preferably used.

As the plasticizer, those usually used in the field of film can be used. For example, phthalic acid such as octyl phthalate (di-2-ethylhexyl phthalate), dibutyl phthalate, dinonyl phthalate, diisononyl phthalate, etc. Diesters, aliphatic dibasic acid diesters such as dioctyl adipate and dioctyl sebacate, phosphate triesters such as tricresyl phosphate and trioctyl phosphate, epoxy plasticizers such as epoxidized soybean oil and epoxy resins, and polymer polyester plastics Agents and the like. The minimum with the preferable addition amount of the said plasticizer with respect to 100 weight part of said vinyl chloride is 10 weight part, and a preferable upper limit is 30 weight part.

The polyvinyl chloride resin may contain a heat stabilizer. As the heat stabilizer, those usually used in the field of films can be used, for example, lead (Pb), barium (Ba), zinc (Zn), calcium (Ca), tin (Sn) and the like. Examples thereof include metal organic acid compounds.

The preferred lower limit of the thickness of the polyvinyl chloride film layer is 30 μm, the preferred upper limit is 400 μm, the more preferred lower limit is 40 μm, the more preferred upper limit is 350 μm, the still more preferred lower limit is 50 μm, and the still more preferred upper limit. Is 300 μm. When the thickness of the polyvinyl chloride film layer is less than 30 μm, it may become too thin when being attached to a substrate having a three-dimensional curved surface portion, and the base may be transparent. When the thickness of the polyvinyl chloride film layer exceeds 400 μm, the followability of the decorative molding film may be insufficient when affixed to a substrate having a three-dimensional curved surface portion.

[Adhesive layer]
The pressure-sensitive adhesive layer contains, as a main agent, a copolymer of methyl acrylate and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms. By using a copolymer (C1 / C4 acrylic pressure-sensitive adhesive) of methyl acrylate and alkyl acrylate containing an alkoxy group having 4 carbon atoms as the main agent, the temperature is lower than that of a hot melt adhesive. It can be molded and can exhibit a high cohesive force even in a high temperature environment such as a hot melt adhesive while exhibiting excellent adhesive strength at room temperature as in a general-purpose pressure-sensitive adhesive. The alkyl acrylate ester containing an alkoxy group having 4 carbon atoms may include any one of butyl acrylate, 1-methylpropyl acrylate, and 2-methylpropyl acrylate, or two or more thereof. May be included. As the main agent, for example, when an acrylic acid alkyl ester (C4 acrylic pressure-sensitive adhesive) containing an alkoxy group having 4 carbon atoms is used alone, the number of carbon atoms such as methyl acrylate and 2-ethylhexyl acrylate is 8 When a copolymer with an alkyl acrylate ester containing an alkoxy group (C1 / C8 acrylic adhesive) is used, it contains an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms and an alkoxy group having 8 carbon atoms. When a copolymer with an acrylic acid alkyl ester (C4 / C8 acrylic adhesive) is used, sufficient adhesive strength cannot be obtained at room temperature and / or high temperature, and sufficient dimensional stability can be obtained. I can't.

The copolymer preferably has a weight average molecular weight of 800,000 to 1,100,000. There exists a possibility that heat resistance may fall that the said weight average molecular weight is less than 800,000. On the other hand, when the weight average molecular weight exceeds 1.1 million, there is a possibility that sufficient adhesive strength cannot be obtained when molding is performed at a low temperature (80 ° C. to 100 ° C.). The weight average molecular weight of the copolymer can be measured by, for example, gel permeation chromatography (GPC).

The glass transition temperature of the copolymer is preferably -60 ° C or higher and -20 ° C or lower. The minimum with said more preferable glass transition temperature is -40 degreeC, and a more preferable upper limit is -30 degreeC. The glass transition temperature can be measured by, for example, a differential scanning calorimetry (DSC).

The pressure-sensitive adhesive layer contains (meth) acrylic acid alkyl ester as an additive. The (meth) acrylic acid alkyl ester may be an acrylic acid alkyl ester or a methacrylic acid alkyl ester. By containing (meth) acrylic acid alkyl ester as the additive, the adhesive strength can be controlled according to the use environment of the decorative molding film.

Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid alkyl esters having 1 to 20 carbon atoms in the alkyl group. Moreover, the copolymer of C1-C20 (meth) acrylic-acid alkylester of an alkyl group and the unsaturated monomer copolymerizable with this may be sufficient. Examples of the copolymerizable unsaturated monomer include aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, vinylpyridine, and the like. It can be obtained by polymerizing 90 to 99.5% by weight of a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group and 0.5 to 10% by weight of the copolymerizable unsaturated monomer. Examples of the polymerization include radical polymerization using an organic peroxide such as benzoyl peroxide and lauryl peroxide, and an azo polymerization initiator such as azobisisobutyronitrile.

The glass transition temperature of the (meth) acrylic acid alkyl ester is 115 ° C. or lower. When the glass transition temperature exceeds 115 ° C., sufficient tackiness cannot be obtained in a room temperature environment. A preferable upper limit of the glass transition temperature is 110 ° C., and a more preferable upper limit is 105 ° C. The glass transition temperature can be measured by, for example, a differential scanning calorimetry (DSC).

The glass transition temperature of the (meth) acrylic acid alkyl ester is preferably 40 ° C. or higher. When the glass transition temperature is 40 ° C. or higher, sufficient adhesive strength can be maintained in an 80 ° C. environment even when the glass transition temperature is molded at a relatively low temperature (80 ° C. to 100 ° C.). Therefore, even if it is a case where it shape | molds in a wide shaping | molding temperature range (80 degreeC-130 degreeC), the adhesive force outstanding in the normal temperature and the high temperature environment of 80 degreeC can be maintained. A more preferable lower limit of the glass transition temperature is 50 ° C.

The weight average molecular weight of the (meth) acrylic acid alkyl ester is 5,000 to 100,000. When the weight average molecular weight is less than 5,000, sufficient adhesive force and dimensional stability cannot be obtained in a high temperature environment at any molding temperature of 80 ° C to 130 ° C. On the other hand, if the weight average molecular weight exceeds 100,000, sufficient adhesive strength cannot be obtained in a high temperature environment at any molding temperature of 80 ° C to 130 ° C. A preferable lower limit of the weight average molecular weight is 10,000, and a more preferable lower limit is 30,000. The weight average molecular weight of the (meth) acrylic acid alkyl ester can be measured, for example, by gel permeation chromatography (GPC).

Content of the said (meth) acrylic-acid alkylester is 1-40 weight part with respect to 100 weight part of said copolymers. When the content is less than 1 part by weight, the decorative molding film has a sufficient adhesive force in an environment of 80 ° C. at any molding temperature of 80 ° C. to 130 ° C. Absent. On the other hand, when the content exceeds 40 parts by weight, the decorative molding film cannot obtain a sufficient adhesive force at room temperature at any molding temperature of 80 ° C to 130 ° C. Moreover, even if content of the said (meth) acrylic-acid alkylester is less than 1 weight part or exceeds 40 weight part, when it shape | molds at low temperature (80 to 100 degreeC), it is sufficient dimension. Stability is not obtained. From the viewpoint of maintaining excellent adhesive strength at room temperature even when molded at a low temperature (80 ° C. to 100 ° C.), the preferred lower limit of the content is 19 parts by weight, and the preferred upper limit is 25 parts by weight. is there.

The pressure-sensitive adhesive layer may contain a curing agent. By containing a curing agent, the dimensional stability of the decorative molding film can be improved. The curing agent is not particularly limited. For example, isocyanate curing agents such as tolylene diisocyanate and hexamethylene diisocyanate, epoxy curing agents such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and tetraglycidyl xylene diamine, Examples thereof include metal chelating agents such as Al, Ni and Zn, and amino resin-based curing agents such as melamine compounds.

The thickness of the pressure-sensitive adhesive layer is preferably 15 μm or more and 50 μm or less. When the thickness of the pressure-sensitive adhesive layer is less than 15 μm, the pressure-sensitive adhesive layer becomes too thin when the decorative molding film is stretched to be attached to a three-dimensional curved surface. In some cases, the adhesive strength to the substrate becomes insufficient. On the other hand, when the thickness exceeds 50 μm, the initial adhesive strength becomes high, so that it may be difficult to reattach. Moreover, since many adhesive compositions are used, it is not economical. The minimum with more preferable thickness of the said adhesive layer is 20 micrometers, and a more preferable upper limit is 40 micrometers.

[separator]
As said separator, what is normally used in the field | area of a film can be used. The separator may be a release film or release paper. Examples of the release film include those obtained by subjecting a resin film such as polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, and polypropylene to easy release treatment. Examples of the release paper include those obtained by subjecting paper such as high-quality paper or glassine paper to easy release treatment. Examples of the easy release treatment include a method of coating the surface of the resin film or paper that contacts the pressure-sensitive adhesive layer with a silicone-based, alkyd-based, or fluorine-based release agent. The separator may be surface-treated only on the surface on the pressure-sensitive adhesive layer side. The thickness of the separator is preferably 12 to 200 μm, and more preferably 50 to 150 μm.

The polyvinyl chloride film layer may be printed on the surface opposite to the pressure-sensitive adhesive layer. Printing on the polyvinyl chloride film layer can be performed by, for example, inkjet printing, gravure printing, screen printing, rotary screen printing, flexographic printing, offset printing, electrostatic printing, and the like. The polyvinyl chloride film layer may have fine irregularities on the surface opposite to the pressure-sensitive adhesive layer by embossing or the like.

The said polyvinyl chloride film layer may have a protective film layer on the opposite side to an adhesive layer. As said protective film, what is normally used in the field | area of a film can be used. Examples of the protective film include polyethylene terephthalate (PET) resin, polypropylene (PP) resin, and polycarbonate resin.

The method for producing the decorative molding film is not particularly limited. For example, the polyvinyl chloride film layer is formed by calendering or the like after melt-kneading the polyvinyl chloride resin using a Banbury mixer or the like. can do. The pressure-sensitive adhesive layer is formed by coating the pressure-sensitive adhesive composition on the release film or release paper using a general-purpose film formation apparatus or film formation method such as various coating apparatuses, bar coats, doctor blades, and the like. It can be formed by drying. A film for decorative molding can be obtained by laminating the pressure-sensitive adhesive layer on the polyvinyl chloride film layer.

The decorative molding film is used by attaching a decorative film from which the separator has been peeled off to a substrate. Since the decorative molding film follows a three-dimensional curved surface, it is suitably used for a base material having a three-dimensional curved surface portion. The decorative molded product of the present invention is a decorative molded product comprising a base material having a three-dimensional curved surface portion and a decorative film covering the three-dimensional curved surface portion, and the decorative film is a decorative film of the present invention. The separator is peeled from the decorative film, and is attached to the three-dimensional curved surface portion via the pressure-sensitive adhesive layer.

Since the decorative molded product uses a decorative molding film having excellent adhesive strength and dimensional stability under normal temperature and high temperature environments, it is used not only at normal temperature but also in an environment exceeding 80 ° C. However, the decorative film is unlikely to float or peel off.

The method for applying the decorative molding film is, for example, stacking a decorative film with a separator peeled on a substrate, vacuum forming, pressure forming, vacuum / pressure forming, in-mold forming, film insert forming, laminating, etc. The method of using and constructing is mentioned. Among these, it is preferable to use vacuum / pressure forming.

The vacuum / pressure forming is also referred to as a TOM (Three Dimension Overlay Method), and can be performed using, for example, a vacuum / pressure forming apparatus. An example of vacuum / pressure forming will be described. First, a decorative film from which a separator is peeled from a decorative molding film and a base material are set in a molding chamber in an atmospheric pressure state. Next, after the molding chamber is airtight, vacuum suction is performed using a vacuum tank, and the molding chamber is vacuumed. Subsequently, while maintaining the vacuum state, the decorative film is softened by heating to a desired molding temperature using a heater. After the substrate is brought into contact with the softened decorative film, the vacuum in the molding chamber is released to atmospheric pressure, and further, compressed air is introduced from the compressed air tank into the molding chamber to press the decorative film against the substrate. And paste along the shape. Thereafter, if necessary, the surplus film protruding from the base material is trimmed. Thereby, the decorative molded product by which the said decorative film was affixed on the base material through the adhesive layer can be obtained.

The material of the base material is not particularly limited. For example, a resin such as a polycarbonate resin, an acrylic resin, or a styrene resin, an acrylonitrile-butadiene-styrene copolymer (ABS resin); a metal such as iron, copper, or aluminum An alloy or the like.

Examples of the base material include, but are not limited to, vehicles such as bicycles, motorcycles, automobiles, buses, and trains; helmets; ships; airplanes such as airplanes and helicopters; household items such as furniture and home appliances; cabinets and office desks And office supplies such as personal computers; wall surfaces, floor surfaces, ceilings, roofs, pillars, signboards, doors, gates of buildings; or building materials on construction sites, or parts thereof.

EXAMPLES Hereinafter, although an Example is hung up and demonstrated in more detail about this invention, this invention is not limited only to these Examples.

Example 1
First, 15 parts by weight of diisononyl phthalate was added as a plasticizer to 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 1100 to obtain a polyvinyl chloride resin. The obtained polyvinyl chloride resin was melt-kneaded with a Banbury mixer, and then a polyvinyl chloride film layer was produced by calendering. The film thickness of the polyvinyl chloride film layer was 200 μm. Next, as a main agent, a copolymer (C1 / C4 system) of methyl acrylate having a weight average molecular weight of 800,000 and a glass transition temperature of −32 ° C. and an alkyl acrylate containing an alkoxy group having 4 carbon atoms. Acrylic adhesive) (solid content 20%) 100 parts by weight, as additives, glass transition temperature 40 ° C., weight average molecular weight of 100,000 alkyl methacrylate ester 25 parts by weight, epoxy curing agent ( 0.15 part by weight of E-AX model, manufactured by Soken Chemical Co., Ltd. was added to prepare an adhesive composition. Using a PET film coated with a silicone release agent as a separator, the resulting adhesive composition was coated on the separator using a comma coater so that the thickness of the adhesive layer after drying was 40 μm. did. Thereafter, the film was transferred to a polyvinyl chloride film layer to obtain a decorative molding film of Example 1.

(Example 2)
A decorative molding film of Example 2 was obtained in the same manner as in Example 1 except that 38 parts by weight of alkyl methacrylate was added to 100 parts by weight of the main agent.

(Example 3)
A decorative molding film of Example 3 was obtained in the same manner as Example 1 except that 12 parts by weight of alkyl methacrylate was added to 100 parts by weight of the main agent.

Example 4
A decorative molding film of Example 4 was obtained in the same manner as in Example 1, except that 6 parts by weight of alkyl methacrylate was added to 100 parts by weight of the main agent.

(Example 5)
A decorative molding film of Example 5 was obtained in the same manner as in Example 1 except that 19 parts by weight of alkyl methacrylate was added to 100 parts by weight of the main agent.

(Example 6)
As a main agent, a copolymer of methyl acrylate having a glass transition temperature of −37 ° C. and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms (manufactured by Soken Chemical Co., Ltd., SK2094) is used, and 100 parts by weight of the main agent is used. On the other hand, a decorative molding film of Example 6 was obtained in the same manner as in Example 1 except that 20 parts by weight of alkyl methacrylate was added.

(Example 7)
As a main agent, a copolymer of methyl acrylate having a glass transition temperature of −37 ° C. and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms (manufactured by Soken Chemical Co., Ltd., SK2094) is used as an additive. The decoration of Example 7 was performed in the same manner as in Example 1 except that an alkyl methacrylate having a glass transition temperature of 50 ° C. was used and 20 parts by weight of the alkyl methacrylate was added to 100 parts by weight of the main agent. A film for molding was obtained.

(Example 8)
As a main agent, a copolymer of methyl acrylate having a glass transition temperature of −37 ° C. and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms (manufactured by Soken Chemical Co., Ltd., SK2094) is used as an additive. The decoration of Example 8 was carried out in the same manner as in Example 1 except that 20 parts by weight of the alkyl methacrylate was added to 100 parts by weight of the main agent using an alkyl methacrylate having a glass transition temperature of 80 ° C. A film for molding was obtained.

Example 9
As a main agent, a copolymer of methyl acrylate having a glass transition temperature of −37 ° C. and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms (manufactured by Soken Chemical Co., Ltd., SK2094) is used as an additive. Example 9 is decorated in the same manner as in Example 1 except that 20 parts by weight of alkyl methacrylate is added to 100 parts by weight of the main agent using alkyl methacrylate having a glass transition temperature of 110 ° C. A film for molding was obtained.

(Example 10)
As a main agent, a copolymer of methyl acrylate having a glass transition temperature of −37 ° C. and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms (manufactured by Soken Chemical Co., Ltd., SK2094) is used as an additive. The decoration of Example 10 was performed in the same manner as Example 1 except that an alkyl methacrylate having a weight average molecular weight of 90,000 was used and 20 parts by weight of the alkyl methacrylate was added to 100 parts by weight of the main agent. A film for molding was obtained.

(Example 11)
A decorative molding film of Example 11 was obtained in the same manner as in Example 1 except that a copolymer having a weight average molecular weight of 1.1 million and a glass transition temperature of −60 ° C. was used as the main agent.

(Example 12)
A decorative molding film of Example 12 was obtained in the same manner as in Example 1 except that a methacrylic acid alkyl ester having a glass transition temperature of 30 ° C. was added as an additive.

(Example 13)
A decorative molding film of Example 13 was obtained in the same manner as Example 1 except that a methacrylic acid alkyl ester having a weight average molecular weight of 30,000 was added as an additive.

(Comparative Example 1)
A decorative molding film of Comparative Example 1 was obtained in the same manner as in Example 1 except that no alkyl methacrylate ester was added as an additive.

(Comparative Example 2)
A decorative molding film of Comparative Example 2 was obtained in the same manner as in Example 1 except that 50 parts by weight of alkyl methacrylate was added to 100 parts by weight of the main agent.

(Comparative Example 3)
As a main agent, a copolymer of a methyl acrylate and an alkyl acrylate containing an alkoxy group having 8 carbon atoms having a weight average molecular weight of 450,000 and a glass transition temperature of −44 ° C. (C1 / C8 acrylic adhesive) The film for decorative molding of Comparative Example 3 was obtained in the same manner as Example 1 except that SK2953 (manufactured by Soken Chemical Co., Ltd.) was used.

(Comparative Example 4)
As a main agent, a pressure-sensitive adhesive (C4 acrylic pressure-sensitive adhesive) containing an alkyl acrylate ester containing a C 4 alkoxy group having a weight average molecular weight of 550,000 and a glass transition temperature of −40 ° C. (manufactured by Soken Chemical Co., Ltd.) The decorative molding film of Comparative Example 4 was obtained in the same manner as in Example 1 except that SK1310) was used and no methacrylic acid alkyl ester was added as an additive.

(Comparative Example 5)
A decorative molding film of Comparative Example 5 was obtained in the same manner as Example 1 except that a methacrylic acid alkyl ester having a glass transition temperature of 120 ° C. was added as an additive.

(Comparative Example 6)
A decorative molding film of Comparative Example 6 was obtained in the same manner as in Example 1 except that a methacrylic acid alkyl ester having a weight average molecular weight of 110,000 was added as an additive.

(Comparative Example 7)
A decorative molding film of Comparative Example 7 was obtained in the same manner as in Example 1 except that a methacrylic acid alkyl ester having a weight average molecular weight of 4,000 was added as an additive.

(Comparative Example 8)
A copolymer of an acrylic acid alkyl ester containing an alkoxy group having 4 carbon atoms and an alkyl alkyl acrylate containing an alkoxy group having 8 carbon atoms, having a weight average molecular weight of 700,000 and a glass transition temperature of −45 ° C. A decorative molding film of Comparative Example 8 was obtained in the same manner as in Example 1 except that C4 / C8 acrylic adhesive (manufactured by Soken Chemical Co., Ltd., SK1717DT) was used.

Table 1 shows the configuration of the pressure-sensitive adhesive layer of the decorative molding film according to the example, and Table 2 shows the configuration of the pressure-sensitive adhesive layer of the decorative molding film according to the comparative example. In Tables 1 and 2, the pressure-sensitive adhesive containing a copolymer of methyl acrylate and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms is “C1 / C4 system”, and the acrylic containing an alkoxy group having 4 carbon atoms. The pressure-sensitive adhesive containing acid alkyl ester monomer is “C4 series”, and the pressure-sensitive adhesive containing a copolymer of methyl acrylate and alkyl acrylate ester containing an alkoxy group having 8 carbon atoms is “C1 / C8 series”. The pressure-sensitive adhesive containing a copolymer of an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms and an alkyl acrylate ester containing an alkoxy group having 8 carbon atoms was denoted as “C4 / C8 series”.

(Evaluation of decorative molding film)
For the decorative molding films prepared in Examples and Comparative Examples, the following methods were used: (1) adhesive strength at room temperature, (2) adhesive strength at 80 ° C., (3) dimensional stability, and (4 ) The followability to the three-dimensional curved surface portion was evaluated. From the evaluation results of (1) to (4), (5) comprehensive evaluation was performed.

(1) Adhesive force at room temperature The decorative molding films prepared in Examples and Comparative Examples were cut into 25 mm length and 180 mm width to obtain test pieces. The separator was peeled off from each test piece, and attached to an ABS resin plate having a length of 25 mm and a width of 180 mm at molding temperatures of 80 ° C., 100 ° C., 120 ° C. and 130 ° C. by vacuum / pressure forming. About each, after leaving at normal temperature (temperature 23 degreeC, humidity 50%) for 24 hours, the 180 degree peeling test was done by the method based on JISZ0237, and the adhesive force was measured. The target value of the adhesive strength at room temperature was 30 N / 25 mm or more.

(2) Adhesive strength at 80 ° C. In the same manner as the above-described evaluation test of adhesive strength at normal temperature, the separator was peeled off from the decorative molding films prepared in Examples and Comparative Examples, and was subjected to 80 ° C. by vacuum / pressure forming. At a molding temperature of 100 ° C., 120 ° C. and 130 ° C., it was attached to an ABS resin plate. About each, after leaving for 1 minute at the temperature of 80 degreeC, the 180 degree peeling test was done by the method based on JISZ0237, and the adhesive force was measured. The target value of the adhesive strength at 80 ° C. was 7 N / 25 mm or more.

(3) Dimensional stability In the same manner as the above-described evaluation test for adhesive strength at room temperature, the separator was peeled off from the decorative molding films prepared in Examples and Comparative Examples, and 80 ° C, 100 ° C, 120 ° C and 130 ° C. At this molding temperature, it was affixed to an ABS resin plate by vacuum / pressure forming. Then, with a cutter knife, a cut of 100 mm was made in each decorative film and stored for 96 hours in an environment at a temperature of 80 ° C. After 96 hours, the cut width of the decorative molding film was measured. The target value of the dimensional stability was such that the cut width was 0.6 mm or less.

(4) Followability to a three-dimensional curved surface part The separator is peeled off from the decorative molding film produced in the examples and comparative examples, and pasted on an ABS resin smartphone cover by vacuum / compression molding at a molding temperature of 120 ° C. I attached. Thereafter, the smartphone cover with the decorative film attached was placed in a gear oven and left at 80 ° C. for 96 hours. The width of the decorative film that floated from the edge of the smartphone cover was measured with calipers. The target value of the followability to the three-dimensional curved surface portion was such that the float at the edge of the decorative film was 0.5 mm or less.

(5) Comprehensive evaluation In the evaluation items (1) and (2) above, there is a molding temperature at which the adhesive strength at normal temperature and the adhesive strength at 80 ° C. meet the target values, and (3) and (4) above. If the evaluation item is satisfied, it was rated as ○. In the evaluation items (1) and (2) above, when molding is performed at all molding temperatures of 80 ° C., 100 ° C., 120 ° C. and 130 ° C., the adhesive strength at normal temperature and the adhesive strength at 80 ° C. are target values. Is satisfied and the evaluation items (3) and (4) above are satisfied. If there were one or more items that deviated from the target values of the evaluation items (1) to (4) above, it was marked as x. In the evaluation items (1) and (2) above, “out of target value” means that there is no molding temperature at which the adhesive strength at room temperature and the adhesive strength at 80 ° C. satisfy the target value.

The evaluation results of the decorative molding film according to the example are shown in Table 3, and the evaluation results of the decorative molding film according to the comparative example are shown in Table 4.

From the results of the examples and comparative examples, the adhesive layer of the decorative molding film was used as a main agent with a copolymer of methyl acrylate and an alkyl acrylate containing an alkoxy group having 4 carbon atoms as an additive. As a (meth) acrylic acid alkyl ester having a glass transition temperature of 115 ° C. or lower and a weight average molecular weight of 5,000 to 100,000, the content of the additive is set to 100 parts by weight of the main agent. 1 to 40 parts by weight, when molded at any molding temperature of 80 ° C., 100 ° C., 120 ° C., and 130 ° C., it follows a curved surface shape and is excellent in normal temperature and high temperature environments It was found that a decorative molding film having adhesive strength and dimensional stability can be obtained.

Claims (6)

Laminated in the order of polyvinyl chloride film layer, adhesive layer, separator,
The pressure-sensitive adhesive layer is a copolymer of methyl acrylate and an alkyl acrylate ester containing an alkoxy group having 4 carbon atoms, and has a glass transition temperature of 115 ° C. or lower and a weight average molecular weight of 5,000 to Containing 100,000 (meth) acrylic acid alkyl esters,
Content of the said (meth) acrylic-acid alkylester is 1-40 weight part with respect to 100 weight part of said copolymers, The film for decorative molding characterized by the above-mentioned. The glass transition temperature of the said (meth) acrylic-acid alkylester is 40 degreeC or more, The film for decorative shaping | molding of Claim 1 characterized by the above-mentioned. Content of the said (meth) acrylic-acid alkylester is 19-25 weight part with respect to 100 weight part of said copolymers, The film for decorative molding of Claim 1 or 2 characterized by the above-mentioned. The film for decorative molding according to any one of claims 1 to 3, wherein the copolymer has a weight average molecular weight of 800,000 to 1,100,000. The thickness of the said adhesive layer is 15 micrometers or more and 50 micrometers or less, The film for decorating shaping | molding in any one of Claims 1-4 characterized by the above-mentioned. A decorative molded product comprising a base material having a three-dimensional curved surface portion and a decorative film covering the three-dimensional curved surface portion,
The said decorating film peels the said separator from the film for decorating shaping | molding in any one of Claims 1-5, and is affixed on the said three-dimensional curved surface part through the said adhesive layer. Decorative molded product characterized by that.