JPH11147237A - Acrylic film for simultaneous lamination of injection molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film suitable for simultaneous lamination of injection molding and the like, and a molded article having the surface hardness using the same and having a deep and transparent feeling. SOLUTION: An acrylic resin containing methyl methacrylate as a main component and having a glass transition temperature of 40 to 105 ° C.
0% by weight, the innermost layer is a hard polymer containing methyl methacrylate as a main component, and the intermediate layer is an alkyl group having 4 to 8 carbon atoms.
Soft rubber elastic body composed of a copolymer of an alkyl acrylate and a polyfunctional monomer, and a three-layer acrylic polymer whose outermost layer is composed of a hard polymer containing methyl methacrylate as a main component. An acrylic film or sheet for simultaneous lamination with injection molding, comprising a resin composition in which the weight percentage is dispersed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic film or sheet (hereinafter, collectively referred to as a film) suitable for simultaneous lamination of injection molding, and a molded article using the same.

[0002]

2. Description of the Related Art The simultaneous lamination method of injection molding is disclosed in
As disclosed in Japanese Unexamined Patent Publication No. 6339, Japanese Patent Publication No. Hei 4-9647 and Japanese Unexamined Patent Publication No. Hei 7-9484, a film inserted between male and female molds during injection molding is mixed with a molten resin injected into a cavity. It is a method of integrating and decorating or painting the surface of a formed body, and is a forming method called a laminating method or a transfer printing method depending on the type of film used.

[0003] That is, in the laminating method, a laminating painting film (laminate film) that becomes a decorative layer by bonding and integrating all the layers of the painting film composed of the base film and the pattern layer to the surface of the molded article is obtained. used. In the transfer printing method, a transfer film is used, and only the base film of the painting film integrated on the surface of the molded body is peeled off, and a transfer layer such as a picture layer is left on the molded body to form a decorative print layer.

Conventionally, in such a method, for example, a vinyl chloride film, a polyester film, a polystyrene film or the like on which a pattern is printed is laminated on a surface of an acrylonitrile-butadiene-styrene (ABS) resin or a polystyrene resin by a lamination method or a transfer printing method. Pasted to obtain a molded product. In the case of a molded product with a woodgrain pattern used for automotive interior applications, the pattern is printed on the surface of the ABS resin molded product by a hydraulic transfer method (curl fit method) or the like, and the surface is made of a transparent material such as urethane. It is manufactured by coating with resin and giving depth.

[0005] The purpose of coating the resin surface in this way is to protect the base material, provide surface functions, impart functions such as transmission shielding properties, or adjust the surface gloss and give a three-dimensional appearance (depth).
Mainly, it is said that the design is improved by adding a picture, and that the structural mechanical strength is added.

[0006] The coating resin is cost, functional,
It is selected from thermoplastic or thermosetting resins depending on the appearance and post-processability. As a thermoplastic resin film,
There are a polyvinyl chloride film (PVC film), a polyolefin film, a polyester film, an acrylic resin film, a fluorine resin film and the like. The acrylic resin film can be heat-sealed with a PVC film, and its weather resistance,
It has a feature that the underlying PVC film can be protected by the ultraviolet shielding performance, and is used for exterior building materials.

As such an acrylic resin film,
JP-B-56-27378 discloses a film comprising a resin composition containing an alkyl methacrylate as a main component, an ultraviolet absorber and the like.

Further, JP-A-51-129449 discloses that
As a multilayer polymer composition, there is disclosed an acrylic resin film having excellent transparency and stress whitening resistance in which the alkyl methacrylate monotonically increases in the multilayer structure from the center toward the outer layer. Examples of commercially available acrylic resin films include acrylic films having a trade name of acrylne or sanjulen.

[0009]

As described above, a generally used polyvinyl chloride film has low weather resistance and, in addition, has a problem that when it is incinerated as waste, it pollutes the environment. Commercially available acrylic resin films used in the field of building materials are generally soft and have low surface hardness. Furthermore, the method of clear-coating the surface of the resin molded product on which the woodgrain pattern is printed in advance with a transparent resin, because the application of the clear layer is repeated coating, the occurrence rate of defects is high, the cost is high, or Since the solvent is used in the factory, there are problems such as generation of environmental pollution.

In view of such circumstances, the present inventors have conducted extensive studies on decorated molded articles while maintaining surface hardness. As a result, a resin in which a multilayer acrylic polymer including a rubber elastic layer is dispersed in a specific acrylic resin is dispersed. A film comprising the composition,
The present inventors have found that they are excellent as a film for simultaneous lamination with injection molding, maintain surface hardness, and can easily produce a decorated molded product at low cost, and have completed the present invention.

[0011]

That is, the present invention is as follows. (1) 95 to 50% by weight of an acrylic resin containing methyl methacrylate as a main component and having a glass transition temperature of 40 to 105 ° C
The innermost layer is a hard polymer mainly composed of methyl methacrylate, and the middle layer is a soft rubber composed of a copolymer of an alkyl acrylate having an alkyl group having 4 to 8 carbon atoms and a polyfunctional monomer. Acrylic film or sheet for simultaneous lamination by injection molding comprising a resin composition in which 5 to 50% by weight of a three-layer acrylic polymer in which an elastic body and an outermost layer are a hard polymer mainly composed of methyl methacrylate is dispersed. . (2) The acrylic film or sheet according to (1), wherein a pattern is printed on one side. (3) A molded article in which the acrylic film or sheet according to (1) or (2) is bonded and integrated to a surface layer of a thermoplastic resin molded article. (4) The acrylic film or sheet according to the above (1) or (2) is inserted between the male and female molds and the acrylic film or sheet is formed on the surface of a molded product obtained by injection molding a thermoplastic resin in the mold. The method for producing a molded article according to the above (3), wherein the molding is performed simultaneously. Hereinafter, the present invention will be described in detail.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The acrylic resin having a glass transition temperature of 40 to 105 ° C. containing methyl methacrylate as a main component used in the present invention has a methyl methacrylate content of at least 50%.
It is a copolymer comprising, by weight, less than 50% by weight of at least one vinyl monomer copolymerizable therewith. To make the glass transition temperature of the acrylic resin 40 to 105 ° C,
The type and amount of these monomers to be copolymerized are adjusted. That is, if the homopolymer of the monomer used for copolymerization has a low glass transition temperature, the glass transition temperature of the copolymer using the monomer decreases.

The vinyl monomers copolymerized with methyl methacrylate include, for example, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, and methacrylic acid. Methacrylates such as 2-hydroxyethyl acid, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hedrooxyethyl acrylate, etc. Acrylic esters, acrylic acid, unsaturated fatty acids such as methacrylic acid, styrene, α
-Methylstyrene, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide, cyclohexylmaleimide and the like. Among them, acrylic acid esters are preferably used. Among the acrylates, alkyl acrylates are particularly preferred, and the higher the number of carbon atoms in the alkyl ester portion, the lower the glass transition temperature can be achieved by a small amount of copolymerization.

As the acrylic resin of the present invention, an acrylic resin obtained by copolymerizing 50 to 99% by weight of methyl methacrylate and 50 to 1% by weight of an alkyl acrylate is preferable. Alternatively, it is used as a mixture of a plurality of copolymers. The mixture may have a glass transition temperature in the range of 40 to 105 ° C. When the glass transition temperature of the acrylic resin exceeds 105 ° C., it is difficult to keep the film of the present invention in a temperature range where the film can be formed when the film of the present invention is laminated in a mold and shaped. Therefore, it is not preferable. On the other hand, when the temperature is lower than 40 ° C., the heat resistance of the film of the present invention is lowered, which is not practically preferable. In addition, the glass transition temperature is preferably 80 ° C. or lower from the viewpoint that the unevenness phenomenon at the time of molding which usually occurs on the film surface during injection molding and bonding can be remarkably improved.

The multi-layer acrylic polymer having a rubber elastic layer in the present invention is at least two layers, preferably three layers of multi-layer acrylic polymer powder. As the two-layer acrylic polymer, the inner layer is a soft rubber composed of a copolymer of an alkyl acrylate having an alkyl group having 4 to 8 carbon atoms and a polyfunctional monomer, and the outer layer is formed of methyl methacrylate. 2 is a hard polymer whose main component is
It is based on a layered structure. The acrylic polymer having a three-layer structure means that the innermost layer is a hard polymer having methyl methacrylate as a main component, and the intermediate layer has an alkyl group having 4 to 8 carbon atoms.
It is based on a three-layer structure consisting of a soft rubber elastic layer made of a copolymer of an alkyl acrylate and a polyfunctional monomer, and a hard polymer whose outermost layer contains methyl methacrylate as a main component. is there. Above all, 20 rubber elastic layers
More preferably, it contains 〜60% by weight. These are described, for example, in JP-B-55-27576 and JP-A-1-252.
No. 653.

A multilayer acrylic polymer containing the rubber elastic layer is added to the acrylic resin in an amount of 5 to 50% by weight.
% By weight. When the acrylic polymer having a multilayer structure containing the rubber elastic layer is less than 5% by weight, the impact strength of the film of the present invention is low and the breaking elongation is small, so that the film can follow the elongation accompanying molding in a mold. It is not preferable because it causes tearing. On the other hand, if it exceeds 50% by weight, the surface hardness of the film is undesirably low. Use of a single-layered elastic body is not preferable because the surface hardness of the obtained film is extremely low. Furthermore, when an acrylic polymer having a three-layer structure is used, improvements in elastic modulus, surface hardness, abrasion resistance, and the like are observed as compared with the case where an acrylic polymer having a two-layer structure is used.

The method of dispersing the acrylic polymer having a multilayer structure containing the rubber elastic layer in the acrylic resin is not particularly limited as long as both are uniformly mixed. Are sufficiently mixed and dispersed using an extruder capable of melt-mixing the thermoplastic resin. During this melt mixing, well-known hindered phenolic antioxidants, phosphorus antioxidants and sulfur antioxidants, weathering agents such as ultraviolet absorbers and hindered amine light stabilizers, flame retardants, coloring agents, pigments, An inorganic filler or the like may be blended. As the ultraviolet absorber, generally, a benzotriazole-based or benzophenone-based ultraviolet absorber is used alone or in combination, but from the viewpoint of eliminating volatilization from the film and preventing deterioration of a printed pattern. And a high-molecular-weight benzotriazole-based ultraviolet absorber is preferred. Specifically, 2,
2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2
H-benzotriazol-2-yl) phenol] is preferably used. In addition, the addition amount is at least 1000
It is desirably set to ppm.

The film of the present invention can be obtained by extrusion casting using a well-known chill roll, extrusion molding in which both sides of the film are brought into contact with the roll surface, and belt cooling extrusion in which both sides are brought into contact with a metal belt. , An inflation extrusion molding method, a solvent casting method and the like. Among them, a method in which the film is obtained in a good surface condition, a method in which both surfaces of the film are brought into contact with a roll surface or a metal belt, and a method in which the film is manufactured by an extrusion molding method or a belt cooling extrusion method is used. It is desirable from the viewpoint of a reduction in haze and an effect of preventing print omission which is a printing characteristic of a picture.

In general, the film of the present invention is often used for simultaneous lamination and injection molding in a state where a picture or the like is printed on one side or colored. In addition, a film obtained by giving a shape in advance by thermoforming such as vacuum forming may be used for simultaneous lamination with injection molding. Further, the film of the present invention may be used as the outermost layer of a multilayer film. That is, a vinyl chloride film, a transparent A
It is also possible to form a multilayer film by backing another resin film such as a BS film.

The film of the present invention has a thickness of 0.1 to 0.6.
mm. The film of the present invention is usually supplied in a state where a pattern or the like is printed on one side, and the printed surface is directed toward the resin side to be melt-injected after the injection molding die. In other words, this is because the purpose is to increase the printing depth of the transparent (clear) layer in the state of the final molded product. For this reason, if the thickness of the film is less than 0.1 mm, the depth of a printed pattern or the like becomes poor, which is not preferable. In addition, in order to industrially carry out the simultaneous lamination of the injection molding of the present invention in a mold, it is preferable to continuously supply the film into the mold. For this reason, if the thickness of the film exceeds 0.6 mm, the film cannot be wound in a continuous roll shape, which is not preferable.

As described above, for example, an ABS resin, a polycarbonate resin, a polystyrene resin, a polyolefin resin or the like can be used as a resin melt-injected into a mold at the time of simultaneous lamination of the film of the present invention during injection molding. ,
It is desirable to select an ABS resin or a polycarbonate resin from the viewpoints of impact resistance, dimensional stability, and the like of the finished product. Further, in the case where the film is continuously supplied as industrial production, a film thickness of 0.1 to 0.2 mm is preferable from the viewpoints of reduction in winding weight and moldability during vacuum forming. In the case of a film thickness exceeding 0.2 mm, it is advantageous to feed the film into the mold every leaf.

Injection molding simultaneous lamination using the film of the present invention is disclosed in JP-B-63-6339, JP-B-4-964.
No. 7, JP-A-7-9484 and the like. That is, open the female mold and the male mold that form the cavity space, insert the film between both molds, close both molds with the film in between, close the mold, and inject the molten resin into the cavity from the gate By filling and cooling and solidifying, a film is adhered and integrated on the surface of the injected molded body, and then both molds are opened to obtain a molded body. Conditions such as the resin temperature and the injection pressure of the injection molding are appropriately set in consideration of the type of the resin and the like.

[0023]

The acrylic film of the present invention is excellent as a film for simultaneous lamination of injection molding. If this film is used, a molded product having a high surface hardness and a deep and transparent feeling can be produced at low cost. It can be easily manufactured.

[0024]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. The evaluation method is as follows. (1) Irregularity generation test during molding: The surface state of the laminated synthetic body was visually observed, and the surface state was evaluated as good, the fine irregularity was evaluated as x, and the middle was evaluated as Δ. (2) Gauze abrasion: A gauze was attached to a measuring jig of a D-type friction tester for dyeing fastness manufactured by Toyo Seiki Seisaku-sho, Ltd., and a 500-reciprocal abrasion test was performed with a load of 200 g to evaluate the evaluation visually. .し な い indicates no wear, X indicates worn, and Δ indicates the middle. (3) Surface hardness: Pencil hardness was measured according to JIS K5400. (4) Transparency: Total light transmittance (Tt) and haze were measured according to the method described in JIS K 6718. (5) Glass transition temperature (Tg): Differential scanning calorimetry (D
SC), the endothermic onset temperature observed when the film sample was heated at a heating rate of 10 ° C./min was determined by the tangential method. (6) Number of missing prints: A picture was gravure-printed on one side of the film, a film having a width of about 1 m and a length of about 10 m was visually inspected, and the number of missing prints was converted per 1 m @ 2.

Example 1 76 parts by weight of pellets of an acrylic resin (methyl methacrylate unit: 97.8% by weight, methyl acrylate unit: 2.2% by weight) obtained by a bulk polymerization method, and rubber having a spherical three-layer structure Elastic layer acrylic polymer (the innermost layer is a crosslinked polymer of methyl methacrylate, the intermediate layer is a soft rubber elastic body containing butyl acrylate as a main component, and the outermost layer is an acrylic polymer of a methyl methacrylate polymer: average particles About 30 in diameter
(0 nm) (see Example 3 of JP-B-55-27576) 24 parts by weight were mixed with a super mixer, and melt-kneaded with a twin-screw extruder to obtain pellets. Next, the pellets were extruded through a T-die at a set temperature of 255 ° C. using a 65 mmφ single screw extruder manufactured by Toshiba Machine Co., Ltd., and cooled so that both surfaces were completely in contact with a polishing roll. A 13 mm acrylic film was obtained.

The obtained acrylic film having a thickness of 0.13 mm was placed in an injection molding die, and ABS resin was injected into the back surface to a thickness of 3 mm to obtain a molded product. At that time, the acrylic film temperature was 130 ° C., the mold temperature was 50 ° C., the injection molding conditions were an injection pressure of 1150 kg / cm ² , and the ABS resin temperature was 230 ° C. Table 1 shows the evaluation results of the obtained films and molded products.

Example 2 75 parts by weight of a powder of an acrylic resin (87% by weight of methyl methacrylate unit, 3% by weight of methyl acrylate unit, 10% by weight of butyl acrylate unit) obtained by a suspension polymerization method, and Twenty-five polymer parts of the rubber elastic layer acrylic polymer having the same three-layer structure as in Example 1 were mixed with a supermixer and melt-kneaded with a twin-screw extruder to form pellets. Next, the pellets were extruded through a T-die at a set temperature of 255 ° C. using a 65 mmφ single screw extruder manufactured by Toshiba Machine Co., Ltd., and cooled to a continuous stainless steel belt cooling device so that both surfaces were completely in contact with each other. An acrylic film having a thickness of 0.13 mm was obtained. Using this acrylic film, a molded article was obtained in the same manner as in Example 1. Table 1 shows the evaluation results of the obtained films and molded products.

Example 3 A film was cooled in the same manner as in Example 2 except that the film was cooled only on one side of the polishing roll. Table 1 shows the evaluation results of the obtained films and molded products.

Example 4 The amount of the acrylic resin powder used in Example 2 was 80
Pellets were obtained in the same manner as in Example 2 except that the amount of the acrylic polymer in the three-layer structure was 20 parts by weight. The procedure was performed in the same manner as in Example 2 except that both surfaces were completely contacted. Table 1 shows the evaluation results of the obtained films and molded products.

Example 5 A rubber elastic layer acrylic polymer having a two-layer structure was used in place of the rubber elastic layer acrylic polymer in Example 4 [a soft rubber elastic body whose inner layer is mainly composed of butyl acrylate,
Acrylic polymer having an outer layer of a methyl methacrylate polymer: average particle size of about 300 nm, Japanese Patent Publication No. 55-2775
Manufactured without forming the innermost layer according to Example 3 of JP-A No. 6]. Table 1 shows the evaluation results of the obtained films and molded products.

Comparative Example 1 A molded article was obtained in the same manner as in Example 1 using a commercially available acrylic film (trade name: Acryprene HBX006, thickness: 0.1 mm: Mitsubishi Rayon Co., Ltd.). In addition, this film was confirmed to contain a rubber elastic body having a single-layer structure, based on the results of observation with a transmission electron microscope. Table 1 shows the evaluation results of the film and the molded product.

[0032]

[Table 1]

Claims (8)

[Claims] 1. An acrylic resin containing methyl methacrylate as a main component and having a glass transition temperature of 40 to 105 ° C. in 95 to 50% by weight, a hard polymer having an innermost layer containing methyl methacrylate as a main component, and an intermediate layer comprising: A soft rubber elastic body made of a copolymer of an alkyl acrylate having 4 to 8 carbon atoms in an alkyl group and a polyfunctional monomer, and an outermost layer made of a hard polymer mainly composed of methyl methacrylate. An acrylic film or sheet for simultaneous lamination with injection molding, comprising a resin composition in which 5 to 50% by weight of an acrylic polymer having a layer structure is dispersed. 2. An acrylic resin comprising 50 to 99% by weight of methyl methacrylate units and 50 to 1% by weight of alkyl acrylate units.
Acrylic film or sheet for simultaneous lamination with injection molding according to 1. 3. The method according to claim 1, wherein the thickness is 0.1 to 0.6 mm.
Acrylic film or sheet for simultaneous lamination with injection molding according to 1. 4. The acrylic film or sheet according to claim 1, wherein a pattern is printed on one side. 5. The acrylic film or sheet for simultaneous injection molding lamination according to claim 1, which is formed by bringing both surfaces into contact with a roll surface or a metal belt surface. 6. A molded product obtained by bonding the acrylic film or sheet for simultaneous lamination of injection molding according to claim 1 or 5 to a surface layer of a thermoplastic resin molded product. 7. The molded article according to claim 6, wherein the thermoplastic resin is an acrylonitrile / butadiene / styrene resin or a polycarbonate resin. 8. A molded product obtained by inserting the acrylic film or sheet for simultaneous lamination of injection molding according to claim 1 or 5 between male and female molds and injection-molding a thermoplastic resin in the molds. The method for producing a molded product according to claim 6, wherein the acrylic film or sheet is simultaneously bonded to a surface.