JP5203315B2 - Multilayer stretched film - Google Patents

Description

  The present invention relates to a multilayer film for bonding molded articles useful for surface decoration of various plastic products. The present invention also relates to a decorative film and a decorative sheet using the multilayer film, and further to a decorative molded product.

  So far, as an acrylic stretched film formed by forming an acrylic resin into a film and stretching it, for example, by adding rubber particles to a single layer acrylic film, the film is given flexibility and its resistance. By adding acrylic rubber particles to the surface layer of a single-layer stretched acrylic film (Patent Document 1) and a multilayer acrylic film that can improve impact properties, the film surface is improved in slipperiness, and the film is wound. A multilayer stretched acrylic film (Patent Document 2) that is easy to remove has been proposed.

JP 2008-299096 A International Publication No. 2008/136346 Pamphlet

  However, the stretched acrylic film containing rubber particles described in Patent Document 1 and Patent Document 2 described above has a problem that whitening occurs due to heating during stretching. Furthermore, such a conventional rubber particle-containing stretched acrylic film is bonded to a molded product for various plastic products (such as an exterior member for home appliances or an interior member for automobiles), and a decorative film for decorating the surface. When it is going to be used, there is also a problem that whitening occurs due to heating during molding. Therefore, there has been a demand for a technique for improving the heat whitening resistance (that is, the property of being difficult to whiten by heat) in a stretched acrylic film containing rubber particles.

  Then, the objective of this invention is providing the stretched film (multilayer stretched film) for molded object bonding which was excellent in heat whitening resistance, while containing a rubber particle.

  The present inventor has intensively studied to solve the above problems. As a result, in a stretched film using a methacrylic resin composition containing methacrylic resin and acrylic rubber particles, the film structure is a thermoplastic resin that does not contain acrylic rubber particles on at least one surface of the layer made of the methacrylic resin composition. When it is laminated so that the layer (B) is present on the surface of the molded article with a film after lamination, it is heat-resistant when it is laminated to a molded article, with a multilayer structure in which layers composed of the composition are laminated. The inventors have found that the whitening property can be remarkably improved and have completed the present invention.

That is, this invention consists of the following structures.
(1) A layer made of a thermoplastic resin composition (b) containing no acrylic rubber particles on at least one surface of a layer (A) made of a methacrylic resin composition (a) containing methacrylic resin and acrylic rubber particles ( B) is a multilayer stretched film for laminating a molded body formed by laminating, and is bonded to the molded body so that the layer (B) is present on the surface of the molded body with a film after laminating. A multilayer stretched film characterized.
(2) The methacrylic resin composition (a) contains methacrylic resin and acrylic rubber particles in a ratio of methacrylic resin: acrylic rubber particles (weight ratio) = 20: 80 to 97: 3. The multilayer stretched film as described in 1).
(3) The multilayer stretching according to (1) or (2), wherein a multilayer film obtained by coextrusion molding of the methacrylic resin composition (a) and the thermoplastic resin composition (b) is stretched. the film.
(4) The multilayer stretched film according to (3), wherein the stretching is biaxial stretching.
(5) The multilayer stretched film according to (3) or (4), wherein a stretch ratio in the stretching direction in the stretching is 1.1 to 3.0.
(6) The multilayer stretched film according to any one of (1) to (5), wherein the total thickness is 10 to 250 μm.
(7) The thermoplastic resin composition (b) has at least one selected from the group consisting of an acrylic resin, a polystyrene resin, a polycarbonate resin, an ABS resin, and an aliphatic polyester resin as the resin component (1) to (1) to (7). The multilayer stretched film according to any one of (6).
(8) The methacrylic resin contained in the methacrylic resin composition (a) is composed of 50 wt% to 100 wt% of alkyl methacrylate, with the total of alkyl methacrylate, alkyl acrylate, and other monomers as 100 wt%. And the multilayer according to any one of the above (1) to (7), which is a polymer obtained by polymerizing 0 to 50% by weight of an alkyl acrylate and 0 to 49% by weight of a monomer other than these. Stretched film.
(9) The elastic polymer part in the acrylic rubber particles has an alkyl acrylate of 50%, with the total of alkyl acrylate, alkyl methacrylate, monofunctional monomer other than these, and polyfunctional monomer being 100% by weight. ˜99.9 wt%, alkyl methacrylate 0-49.9 wt%, monofunctional monomer 0-49.9 wt%, polyfunctional monomer 0.1-10 wt% The multilayer stretched film according to any one of the above (1) to (8), which contains an elastic polymer obtained by polymerizing the polymer and has an average particle diameter of 40 to 800 nm.
(10) The acrylic rubber particles are formed on the outside of the elastic polymer portion with a total amount of alkyl methacrylate, alkyl acrylate, other monofunctional monomer, and polyfunctional monomer as 100% by weight. 50-100% by weight of alkyl acid, 0-50% by weight of alkyl acrylate, 0-50% by weight of monofunctional monomer, and 0-10% by weight of polyfunctional monomer The multilayer stretched film according to (9), which is a particle having a layer made of a hard polymer.
(11) The elastic polymer part in the acrylic rubber particles is composed of alkyl methacrylate, alkyl acrylate, a monofunctional monomer other than these, and a polyfunctional monomer of 100% by weight, and alkyl methacrylate is 70%. Rigid polymer obtained by polymerizing ˜100 wt%, alkyl acrylate 0-30 wt%, monofunctional monomer 0-30 wt%, and polyfunctional monomer 0-10 wt% The multilayer stretched film according to (9) or (10), which contains

(12) Of the multilayer stretched film according to any one of (1) to (11), the layer (A) is formed on the multilayer stretched film in which the layer (B) is laminated on one surface of the layer (A). ) A decorative film characterized in that the surface is decorated.
(13) Among the multilayer stretched films according to any one of (1) to (11), either one of the multilayer stretched films in which the layer (B) is laminated on both sides of the layer (A) A decorative film characterized in that the surface is decorated.
(14) A decorative sheet, wherein a thermoplastic resin sheet is laminated on a surface on the decorative side of the decorative film according to (12) or (13).
(15) A decorative molded product, wherein a thermoplastic resin is injection-molded on the surface on the decorative side of the decorative film according to (12) or (13).
(16) A decorative molded product, wherein a thermoplastic resin is injection-molded on the surface of the decorative sheet according to (14) on the thermoplastic resin sheet side.

  ADVANTAGE OF THE INVENTION According to this invention, although containing a rubber particle, the multilayer stretched film for bonding of a molded object excellent in heat whitening-proof property can be provided. And if the decorative film or decorative sheet using this multilayer stretched film is used, it becomes possible to easily decorate the surface of various plastic products, and decorative molded products with excellent design properties Can be obtained.

  The multilayer stretched film of the present invention comprises a thermoplastic resin composition (b) containing no acrylic rubber particles on at least one surface of a layer (A) comprising a methacrylic resin composition (a) containing methacrylic resin and acrylic rubber particles. The layer (B) made up of) is laminated.

The said methacrylic resin composition (a) which is a forming material of a layer (A) contains a methacrylic resin as a resin component.
The methacrylic resin is a polymer mainly composed of methacrylic acid ester, and may be a homopolymer of methacrylic acid ester, or methacrylic acid ester and other monomers (specifically, alkyl acrylate). Or a copolymer with a monomer copolymerizable with alkyl methacrylate or alkyl acrylate). Here, as the methacrylic acid ester, an alkyl ester of methacrylic acid is usually used. In addition, only 1 type may be sufficient as a methacryl resin, and 2 or more types may be sufficient as it.

  As the alkyl methacrylate, those having an alkyl group having 1 to 8 carbon atoms, preferably 1 to 4 are usually used. Specific examples include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and the like. Among these, methyl methacrylate is preferable. Two or more kinds of alkyl methacrylates may be used as necessary.

  As the alkyl acrylate, those having an alkyl group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms are usually used. Specific examples include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. Two or more kinds of alkyl acrylates may be used as necessary.

  The monomer copolymerizable with alkyl methacrylate or alkyl acrylate (hereinafter also referred to as “monomer other than alkyl methacrylate and alkyl acrylate”) is a monofunctional monomer, May be a compound having one polymerizable carbon-carbon double bond, or a polyfunctional monomer, that is, a compound having at least two polymerizable carbon-carbon double bonds in the molecule. However, a monofunctional monomer is preferably used. Here, examples of the monofunctional monomer include aromatic alkenyl compounds such as styrene, α-methylstyrene, and vinyl toluene; alkenyl cyan compounds such as acrylonitrile and methacrylonitrile; acrylic acid, methacrylic acid, maleic anhydride, N-substituted maleimides; and the like. Examples of polyfunctional monomers include polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, trimethylolpropane triacrylate; allyl acrylate, allyl methacrylate, cinnamon Alkenyl esters of unsaturated carboxylic acids such as allyl acid; polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, triallyl isocyanurate; aromatic polyalkenyl compounds such as divinylbenzene; etc. Is mentioned. Two or more types of monomers other than alkyl methacrylate and alkyl acrylate may be used as necessary.

  The composition of the monomer component constituting the methacrylic resin (the methacrylate ester, the alkyl acrylate, and the monomer other than the alkyl methacrylate and the alkyl acrylate) is 100% by weight of the total of all monomers. The alkyl methacrylate is preferably 50 to 100% by weight, the alkyl acrylate is preferably 0 to 50% by weight, and the monomers other than the alkyl methacrylate and the alkyl acrylate are preferably 0 to 49% by weight, more preferably, It is preferable that the alkyl methacrylate is 50 to 99.9% by weight, the alkyl acrylate is 0.1 to 50% by weight, and the monomers other than the alkyl methacrylate and the alkyl acrylate are 0 to 49% by weight.

  The methacrylic resin can be prepared by polymerizing the above-described monomer components by a known method such as suspension polymerization, emulsion polymerization, or bulk polymerization. In that case, in order to adjust to a suitable glass transition temperature, or in order to obtain the viscosity which shows suitable moldability when producing a multilayer stretched film, it is preferable to use a chain transfer agent at the time of superposition | polymerization. The amount of the chain transfer agent may be appropriately determined according to the type of monomer component and the composition thereof.

  The glass transition temperature of the methacrylic resin is usually 40 ° C. or higher, preferably 60 ° C. or higher. There exists a possibility that the heat resistance of a layer (A) may fall that the glass transition temperature of a methacryl resin is less than 40 degreeC. The glass transition temperature of the methacrylic resin can be appropriately set by adjusting the type and ratio of each monomer in the monomer component constituting the methacrylic resin. In addition, the glass transition temperature of a methacryl resin can be measured by the method as described in the Example mentioned later, for example.

  The methacrylic resin composition (a) which is a material for forming the layer (A) also contains acrylic rubber particles having an elastic polymer part together with the methacrylic resin. Such an acrylic rubber particle has a layer (elastic polymer layer) made of an elastic polymer mainly composed of an acrylate ester, and may be a single-layer particle made of only an elastic polymer, or an elastic weight. It may be a particle having a multilayer structure constituted by a combined layer and a layer made of a hard polymer (hard polymer layer). In addition, only 1 type may be sufficient as an acrylic rubber particle, and 2 or more types may be sufficient as it.

  When the acrylic rubber particles have a multilayer structure, the layer structure is not particularly limited. For example, the acrylic rubber particles have a two-layer structure including an inner layer (elastic polymer layer) / outer layer (hard polymer layer), an inner layer (hard heavy layer). Combined layer) / outer layer (elastic polymer layer) two-layer structure, inner layer (hard polymer layer) / intermediate layer (elastic polymer layer) / outer layer (hard polymer layer) three-layer structure, inner layer (elastic) 3 layer structure consisting of polymer layer) / intermediate layer (hard polymer layer) / outer layer (elastic polymer layer), inner layer (elastic polymer layer) / inner layer side intermediate layer (hard polymer layer) / outer layer side intermediate layer Examples include a four-layer structure composed of (elastic polymer layer) / outer layer (hard polymer layer). In addition, in the structure in which the outermost layer is a hard polymer layer among these layer structures, the outer surface is further covered with a hard polymer layer having a different composition, specifically, for example, an inner layer (elastic polymer layer). / 3 layer structure consisting of intermediate layer (hard polymer layer) / outer layer (hard polymer layer), inner layer (hard polymer layer) / inner layer side intermediate layer (elastic polymer layer) / outer layer side intermediate layer (hard polymer) Layer) / outer layer (hard polymer layer) may be used.

  The elastic polymer part in the acrylic rubber particle is a part containing at least an elastic polymer. Specifically, when the acrylic rubber particle is a single layer particle made of only an elastic polymer, the acrylic rubber particle On the other hand, when the acrylic rubber particles are particles having a multilayer structure, the outermost elastic polymer layer among the layers constituting the acrylic rubber particles and the inner part covered with the elastic polymer layer Means. That is, the elastic polymer portion of the acrylic rubber particles includes all elastic polymer layers constituting the rubber particles. For example, when the acrylic rubber particles have a two-layer structure consisting of an inner layer (elastic polymer layer) / outer layer (hard polymer layer), only the inner layer corresponds to the elastic polymer portion, and the acrylic rubber particles are the inner layer (hard Polymer layer) / intermediate layer (elastic polymer layer) / outer layer (hard polymer layer), the inner layer and the intermediate layer correspond to the elastic polymer portion, and the acrylic rubber particles are the inner layer. In the case of a three-layer structure consisting of (elastic polymer layer) / intermediate layer (hard polymer layer) / outer layer (hard polymer layer), only the inner layer corresponds to the elastic polymer portion.

  The elastic polymer layer constituting the acrylic rubber particles includes an alkyl acrylate and a polyfunctional monomer, and polymerizes a monomer component including an alkyl methacrylate and other monofunctional monomers as necessary. It is preferable that the elastic polymer is formed.

  Examples of the alkyl acrylate used when forming the elastic polymer layer include the same ones as described above as the alkyl acrylate constituting the methacrylic resin, and among them, butyl acrylate and acrylic acid, among others. Those having an alkyl group having 4 to 8 carbon atoms such as 2-ethylhexyl are preferred. In addition, these alkyl acrylates may be only 1 type, and 2 or more types may be sufficient as them.

  Examples of the polyfunctional monomer used in forming the elastic polymer layer include the polyfunctional monomers described above as examples of monomers other than the alkyl methacrylate and alkyl acrylate constituting the methacrylic resin. Any material that exhibits a function as a so-called crosslinking agent or grafting agent may be used. Specific examples include the same polyfunctional monomers that constitute the methacrylic resin, and among them, alkenyl esters of unsaturated carboxylic acids and polyalkenyl esters of polybasic acids are preferably exemplified. In addition, these polyfunctional monomers may be only 1 type, and 2 or more types may be sufficient as them.

Examples of the alkyl methacrylate optionally used for forming the elastic polymer layer include the same ones as described above as the alkyl methacrylate constituting the methacrylic resin. In addition, these alkyl methacrylate may be only 1 type, and 2 or more types may be sufficient as it.
Examples of other monofunctional monomers that are optionally used in forming the elastic polymer layer include the monofunctional monomers described above as examples of monomers other than alkyl methacrylate and alkyl acrylate constituting the methacrylic resin. Examples thereof include those similar to the monomer, and among them, aromatic alkenyl compounds such as styrene, α-methylstyrene and vinyltoluene are preferable. In addition, these monofunctional monomers may be only 1 type, and 2 or more types may be sufficient as them.

  The preferred composition of the monomer component forming the elastic polymer layer in the acrylic rubber particles is, for example, the total of alkyl acrylate, alkyl methacrylate, other monofunctional monomers, and polyfunctional monomers. As 100% by weight, alkyl acrylate is 50 to 99.9% by weight, alkyl methacrylate is 0 to 49.9% by weight, monofunctional monomer is 0 to 49.9% by weight, and polyfunctional monomer is 0. .1 to 10% by weight.

The hard polymer layer constituting the acrylic rubber particles usually contains an alkyl methacrylate, and if necessary, a monomer containing an alkyl acrylate and other monofunctional monomers and polyfunctional monomers. It is preferably formed of a hard polymer obtained by polymerizing components.
Examples of the alkyl methacrylate used for forming the hard polymer layer include the same as those described above as the alkyl methacrylate constituting the methacrylic resin, and among them, methyl methacrylate is preferably mentioned. . In addition, these alkyl methacrylate may be only 1 type, and 2 or more types may be sufficient as it.

Examples of the alkyl acrylate optionally used for forming the hard polymer layer include the same as those described above as the alkyl acrylate constituting the methacrylic resin. What has the alkyl group which is -4 is mentioned preferably. In addition, these alkyl acrylates may be only 1 type, and 2 or more types may be sufficient as them.
As the monofunctional monomer optionally used in forming the hard polymer layer, the monofunctional monomer described above as an example of monomers other than alkyl methacrylate and alkyl acrylate constituting the methacrylic resin The same thing is mentioned. In addition, these monofunctional monomers may be only 1 type, and 2 or more types may be sufficient as them.
As the polyfunctional monomer optionally used in forming the hard polymer layer, the polyfunctional monomer described above as an example of monomers other than alkyl methacrylate and alkyl acrylate constituting the methacrylic resin The same thing is mentioned. In addition, these polyfunctional monomers may be only 1 type, and 2 or more types may be sufficient as them.

  A preferable composition of the monomer component forming the hard polymer layer in the acrylic rubber particles is, for example, when the hard polymer layer is present outside the elastic polymer portion, alkyl methacrylate, alkyl acrylate, The total of the monofunctional monomer other than the above and the polyfunctional monomer is 100% by weight, the alkyl methacrylate is 50 to 100% by weight, the alkyl acrylate is 0 to 50% by weight, and the monofunctional monomer is 0 to 0%. 50 wt%, polyfunctional monomer is 0 to 10 wt%, and on the other hand, when the hard polymer layer is present inside the elastic polymer portion (that is, the elastic polymer portion is In case of containing), alkyl methacrylate, alkyl acrylate, monofunctional monomer other than these, and polyfunctional monomer as a total of 100% by weight, alkyl methacrylate is 70-100% by weight Alkyl acrylate 0-30% by weight, the monofunctional monomer is 0-30 wt%, a polyfunctional monomer is 0-10 wt%.

  The weight ratio of the elastic polymer layer and the hard polymer layer constituting the acrylic rubber particles is not particularly limited. For example, the ratio of the elastic polymer layer and the hard polymer layer that are adjacent to each other is the elastic weight. The hard polymer is usually 10 to 400 parts by weight, preferably 20 to 200 parts by weight with respect to 100 parts by weight of the coalescence.

  The acrylic rubber particles as described above can be synthesized into the latex by, for example, a known emulsion polymerization method, and then coagulated by an appropriate recovery operation (for example, salting out, aciding out, freezing, etc., and then filtered. Then, it can be obtained by a method of isolating it as a powder by performing a washing method, a method of collecting by spray drying, and the like. In emulsion polymerization, polymerization may be carried out in order from the monomer component constituting the polymer that forms the inner (center side) layer of the acrylic rubber particles. For example, inner layer (elastic polymer layer) / outer layer (hard weight) In the case of rubber particles having a two-layer structure composed of a coalesced layer), first, a monomer component constituting an elastic polymer as an inner layer is polymerized to obtain a latex containing elastic polymer particles. What is necessary is just to graft a hard polymer on the particle | grains of an elastic polymer by adding and polymerizing the monomer component which comprises the hard polymer used as an outer layer. The polymerization for forming each layer may be carried out by a single-stage reaction or by a multi-stage reaction of two or more stages. In the case of performing the reaction in two or more stages, the composition of the monomer used in each stage is not particularly limited, and the composition of all the monomer components used in the multistage reaction for forming the layer is within the predetermined range described above. It only has to be inside.

  The average particle diameter of the elastic polymer part in the acrylic rubber particles is preferably 40 to 800 nm. More preferably, the average particle diameter of the elastic polymer portion is 60 to 600 nm. If the average particle diameter of the elastic polymer part in the acrylic rubber particles is less than 40 nm, the impact resistance may be reduced and the film may be easily broken. On the other hand, if it exceeds 800 nm, the transparency of the resulting film may be reduced. There is. The average particle diameter of the elastic polymer part in the acrylic rubber particles can be controlled, for example, by adjusting the amount of emulsifier added, the amount of monomer component used, and the like when obtaining the acrylic rubber particles by emulsion polymerization. .

  When acrylic rubber particles having a layer structure in which the outermost layer (outer layer) is a hard polymer layer are used, the average particle diameter of the elastic polymer portion (that is, the outermost elasticity among the layers constituting the acrylic rubber particles) The average particle diameter of the particles excluding the hard polymer layer outside the polymer layer is, for example, mixed with a methacrylic resin containing the acrylic rubber particles in the methacrylic resin composition (a) to form a film. After the elastic polymer layer is dyed with ruthenium oxide in the cross section, it can be obtained from the diameter (outer diameter) of the dyed portion by observing with an electron microscope. When acrylic rubber particles are mixed with methacrylic resin and the cross section is dyed with ruthenium oxide, the acrylic rubber particles are in a state where the hard polymer layer (outermost layer (outer layer)) outside the elastic polymer layer is removed. For example, if the rubber particles have a two-layer structure consisting of an inner layer (elastic polymer layer) / outer layer (hard polymer layer), only the inner elastic polymer layer is observed. If the rubber particles are dyed and observed as single-layer particles and have a three-layer structure consisting of an inner layer (hard polymer layer) / intermediate layer (elastic polymer layer) / outer layer (hard polymer layer), A certain hard polymer layer and an inner layer hard polymer layer at the center of the particle are not dyed, but only an elastic polymer layer as an intermediate layer is observed as a dyed two-layer particle.

  In the methacrylic resin composition (a), the content ratio of the methacrylic resin and the acrylic rubber particles is preferably methacrylic resin: acrylic rubber particles (weight ratio) = 20: 80 to 97: 3. More preferably, methacrylic resin: acrylic rubber particles (weight ratio) = 30: 70 to 95: 5, and still more preferably, methacrylic resin: acrylic rubber particles (weight ratio) = 40: 60 to 93: 7. . If the content ratio of the acrylic rubber particles is less than the above range, the flexibility of the obtained film may be reduced and the film may be easily broken. On the other hand, if the content ratio is more than the above range, the surface hardness of the obtained film may be reduced. In addition to being easily scratched, the appearance of the molded article may deteriorate when molded.

  The thermoplastic resin composition (b), which is a material for forming the layer (B), is not particularly limited as long as it does not contain acrylic rubber particles, and its resin component is not particularly limited. For example, an acrylic resin, a polystyrene resin, As the resin component, at least one selected from the group consisting of polycarbonate resin, ABS resin, and aliphatic polyester resin is preferable. Among these, it is possible to use the same methacrylic resin as the acrylic resin, particularly the methacrylic resin composition (a) as the resin component of the thermoplastic resin composition (b), and to obtain transparency and surface hardness of the film. From the viewpoint of smoothness and the like. In addition, only 1 type may be sufficient as the resin component of a thermoplastic resin composition (b), and 2 or more types may be sufficient as it.

For the methacrylic resin composition (a) and the thermoplastic resin composition (b), respectively, for example, an ultraviolet absorber, a plasticizer, an organic dye, an inorganic dye, a pigment, and an antioxidant, as necessary. Further, various additives such as an antistatic agent and a surfactant may be contained within a range not impairing the effects of the present invention.
The thermoplastic resin composition (a) and the methacrylic resin composition (b) are conventionally known, for example, by melt-kneading the above-described resin component and other components, for example, with a single screw extruder or a twin screw extruder. Can be prepared by the method.

  In obtaining the multilayer stretched film of the present invention, the production method is not particularly limited. For example, i) by forming the methacrylic resin composition (a) and the thermoplastic resin composition (b) into a multilayer film. A multilayer film in which the layer (B) composed of the thermoplastic resin composition (b) is laminated on at least one surface of the layer (A) composed of the methacrylic resin composition (a) is obtained, and then the multilayer film is stretched And ii) a methacrylic resin composition that constitutes the layer (A) by forming the methacrylic resin composition (a) and the thermoplastic resin composition (b) separately and then stretching the film. After obtaining a stretched film composed of the product (a) and a stretched film composed of the thermoplastic resin composition (b) constituting the layer (B), the layer (A) is made from the methacrylic resin composition (a). On at least one surface of the stretched film, it is possible to adopt a method of laminating a stretched film comprising a layer (B) to the thermoplastic resin composition (b), and the like. Of these, the method i) is preferably employed.

  In the case of obtaining a multilayer stretched film by the method i), as a method for forming the methacrylic resin composition (a) and the thermoplastic resin composition (b) into a multilayer film, for example, a methacrylic resin composition (a) And the thermoplastic resin composition (b) are each melted in an extruder and co-extruded by a feed block method or a multi-manifold method, thereby laminating (co-extrusion molding method) or forming materials ( Either one of the methacrylic resin composition (a) and the thermoplastic resin composition (b)) is formed into a film by an extrusion molding method or the like, and a material for forming the other layer is formed on the surface of the film as necessary. A method of coating by dissolving in a solvent or the like is preferably employed. In particular, a coextrusion molding method with a simple manufacturing process is preferable, and the multilayer stretched film of the present invention is obtained by coextrusion molding of the methacrylic resin composition (a) and the thermoplastic resin composition (b). It is preferable that the multilayer film is stretched.

  In the case of forming a multilayer film by the coextrusion molding method, the melted layer forming material (methacrylic resin composition (a) and thermoplastic resin composition (b)) is brought into close contact with a roll or a belt to form a film. At this time, the number of rolls and belts, the arrangement, the material, etc. are not particularly limited, but for example, each molten layer forming material is contacted and passed between two metal rolls or between a metal roll and a metal belt, It is preferable to transfer the surface of the roll or belt because the surface accuracy of the film surface can be improved and the decorating property can be improved. In addition, using a metal roll and a metal roll with elastic surface (metal elastic roll), if both sides of each layer-forming material melted on the surface are contacted and passed, distortion during molding is reduced, and strength and heat shrinkage are reduced. It is preferable because a film with little property anisotropy can be obtained. Here, the metal elastic roll includes, for example, a shaft roll and a cylindrical metal thin film disposed so as to cover the outer peripheral surface of the shaft roll, and water is provided between the shaft roll and the metal thin film. And a material in which a temperature-controlled fluid such as oil or oil is enclosed, or a material in which a metal belt is wound around the surface of a rubber roll.

As a stretching method for obtaining a multilayer stretched film by the method i) or ii), a conventionally known stretching method may be employed. For example, uniaxial stretching such as free-width uniaxial stretching or constant-width uniaxial stretching. And biaxial stretching such as sequential biaxial stretching and simultaneous biaxial stretching. Among these, biaxial stretching is preferable, and simultaneous biaxial stretching is particularly preferable in that unevenness of mechanical strength of the film can be suppressed.
When stretching, the stretching ratio in the stretching direction is preferably in the range of 1.1 to 3.0 times in order to improve the mechanical strength of the stretched film obtained, and 1.6 to 2 More preferably, it is 0.0 times.

The stretching temperature at the time of stretching may be appropriately set according to the glass transition temperature of the material forming the film (multilayer film) to be stretched, and is not particularly limited. For example, the thermoplastic resin composition (b) When a methacrylic resin is used as the glass transition temperature of the thermoplastic resin composition (b) as Tgb (° C.), the stretching temperature is preferably (Tgb + 10) ° C. to (Tgb + 70) ° C., more preferably ( Tgb + 15) ° C. to (Tgb + 60) ° C., more preferably (Tgb + 20) ° C. to (Tgb + 40) ° C. If the stretching temperature is too low, the resulting stretched film may be broken. On the other hand, if the stretching temperature is too high, the appearance of the film may be deteriorated due to the flow of the resin.
The stretching speed at the time of stretching is preferably in the range of 0.1 to 3.0 m / min. When the stretching speed is slower than 0.1 m / min, it takes a long time to obtain a sufficient stretching ratio, which tends to be disadvantageous in terms of productivity, while it is more than 3.0 m / min. If it is fast, the resulting stretched film may be uneven in thickness.

  The multilayer stretched film thus obtained preferably has a total thickness of 10 to 250 μm, more preferably 30 to 240 μm, and even more preferably 40 to 230 μm. If the thickness of the entire multilayer stretched film is too thick, for example, it will take a long time to decorate automobile interior materials, etc., and the effect of improving physical properties and design properties by decoration will be reduced, which is disadvantageous in terms of cost. Tend to be. On the other hand, if the total thickness of the multilayer stretched film is too thin, film formation by extrusion or the like becomes mechanically difficult, and the breaking strength of the film is lowered, and the probability of occurrence of defects during film production tends to increase. is there. The total thickness of the multilayer film can be adjusted by adjusting the film forming speed, the thickness of the T-die discharge port, the gap between rolls, and the like.

  The thickness of the layer (A) in the multilayer stretched film of the present invention is preferably 30 to 98% of the total thickness of the multilayer stretched film, and the thickness of each layer (B) is preferably 1 μm or more, More preferably, it is 3 μm or more. When the thickness of the layer (A) is too thin, the multilayer stretched film is fragile and may be easily broken. Further, if the thickness of the layer (B) is less than 1 μm, the heat whitening resistance of the multilayer stretched film may be insufficient. The thickness of each layer (B) may be the same or different.

  The multilayer stretched film of the present invention as described above has the layer (B) containing no acrylic rubber particles on at least one surface, and is a stretched film used for bonding a molded body. The multilayer stretched film for bonding a molded body is bonded to the molded body such that the layer (B) is present on the surface of the molded body with a film after bonding. Such a multilayer film of the present invention is suitable as a decorative film or a decorative sheet. In addition, the laminating method which can be applied when laminating the multilayer stretched film of the present invention to a molded body is not particularly limited. For example, the injection molding simultaneous laminating method described later, the multilayer stretched film is water, etc. For example, there may be mentioned a method in which the product is brought into close contact with each other by placing it on the molded body.

  The decorative film of the present invention is: i) the multilayer (A) side of the multilayer stretched film of the present invention, wherein the layer (B) is laminated on one surface of the layer (A). (This embodiment is referred to as “first form”), or ii) layers (A) on both sides of the multilayer stretched film of the present invention ( The multilayer stretched film formed by laminating B) is decorated on either side (this mode is referred to as “second mode”). Thus, in the decorative film of the present invention, a specific surface is decorated according to the laminated form of the multilayer stretched film. Since the decorative film is usually arranged so that the decorative surface is in contact with the molded body, the decorative molded product decorated with the decorative film of the present invention does not contain acrylic rubber particles. The surface of the layer (B) is always located on the surface side, and as a result, heat whitening resistance can be improved. For example, when the simplicity (decoration property) at the time of decorating, the surface hardness of the decorative molded product to be obtained, and the like are taken into consideration, the second form is preferable.

  The method for decorating the multilayer stretched film is not particularly limited, for example, a method of directly printing various designs such as wood grain on the surface of the multilayer stretched film by continuous gravure printing, silk printing, etc. It is possible to employ a method of decorating a metal plating tone by vapor deposition or sputtering, or a method of laminating a resin film that has been previously decorated by printing or vapor deposition.

  The decorative sheet of the present invention is obtained by laminating a thermoplastic resin sheet as a backing material on the surface on the decorative side of the decorative film of the present invention. Here, the resin constituting the thermoplastic resin sheet is not particularly limited, and examples thereof include ABS resin, methacrylic resin, polyvinyl chloride resin, polyurethane resin, polyester resin, and polyolefin resin. Further, the thickness of the thermoplastic resin sheet includes the thickness of a so-called film region, and is usually about 0.1 to 2 mm.

  In the decorative molded product of the present invention, the thermoplastic resin is injected on the surface on the decorative side of the decorative film of the present invention or on the surface on the thermoplastic resin sheet side of the decorative sheet of the present invention. It is formed. Thus, by performing injection molding so that the resin layer surface on which the decorative layer is not provided is located on the surface of the resulting decorative molded product, it has good design properties, impact resistance, A decorative molded product having excellent surface hardness and strength can be obtained. Here, the thermoplastic resin used for injection molding is not particularly limited, and examples thereof include ABS resin, methacrylic resin, polyvinyl chloride resin, polyurethane resin, polyester resin, and polyolefin resin.

  As a method for obtaining the decorative molded product of the present invention, an injection molding simultaneous bonding method is preferably employed. Specifically, the injection molding simultaneous bonding method is as follows: i) Inserting a decorative film or decorative sheet into an injection mold without preforming and injecting a molten resin therein to form an injection molded product At the same time, a method of bonding a decorative film or decorative sheet to the molded product (sometimes referred to as “injection molding simultaneous bonding method” in a narrow sense), ii) vacuum forming a decorative film or decorative sheet After preforming by pressure molding etc., insert into injection mold and inject molten resin into it to form injection molded product, and at the same time, paste decorative film or decorative sheet to the molded product (Iii) A decorative film or sheet is pre-molded by vacuum molding or pressure molding in an injection mold, and then a molten resin is added to the decorative film or sheet. Inject And by, at the same time to form an injection molded article, the method for laminating a decorative film or decorative sheet to the molded article (sometimes referred to as "in-mold molding method") can be carried out by such. For further details of the injection molding simultaneous bonding method, for example, according to a conventionally known technique as described in Japanese Patent Publication No. 63-6339, Japanese Patent Publication No. 4-9647, Japanese Patent Application Laid-Open No. 7-9484, etc. That's fine.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example. In the following, “parts” and “%” representing the content or amount used mean “parts by weight” and “% by weight” unless otherwise specified.

The stretched films obtained in the following examples and comparative examples were evaluated by the following methods.
<Total light transmittance (Tt)>
A 100 mm square test piece was prepared from the obtained stretched film, and the total light transmittance (Tt) (%) was measured according to JIS-K7361-1.

<Haze (ΔH)>
From the obtained stretched film and a film (multilayer film) before stretching the film, 100 mm square test pieces were prepared, and each haze value (%) was measured in accordance with JIS-K7136. . And the value which deducted the haze value of the film before extending | stretching this film from the haze value of the stretched film was computed, and this was made into (DELTA) H (%). It can be said that the smaller the value of ΔH, the better the heat whitening resistance.

<Transparency when bonding>
Water is applied to the surface of a black-colored methacrylic resin plate (molded body), and the stretched film cut into 4 cm × 6 cm is applied onto the applied water, and the layer ( B) was present (in other words, the layer (A) was in contact with water), and a molded article with a film was prepared in which a stretched film was adhered and bonded to the surface of the molded article.
While illuminating the film side of the obtained molded article with a film with a light source (fluorescent lamp), the film surface was visually observed from an oblique 45 ° direction on the film. Was judged to be “x”.

The methacrylic resin and acrylic rubber particles used in the following examples and comparisons are as follows.
<Methacrylic resin>
As the methacrylic resin, thermoplastic polymer pellets (glass transition temperature 104 ° C.) obtained by bulk polymerization of monomer components consisting of 97.8% methyl methacrylate and 2.2% methyl acrylate are used. It was. This glass transition temperature is an extrapolated glass transition start temperature obtained at a heating rate of 10 ° C./min by differential scanning calorimetry according to JIS-K7121: 1987.

<Acrylic rubber particles>
As acrylic rubber particles, the inner layer is a hard polymer obtained by polymerizing a monomer component consisting of 93.8% methyl methacrylate, 6% methyl acrylate, and 0.2% allyl methacrylate, The layer is an elastic polymer obtained by polymerizing a monomer component consisting of 81% butyl acrylate, 17% styrene and 2% allyl methacrylate, and the outer layer is 94% methyl methacrylate and 6% methyl acrylate. Is a hard polymer obtained by polymerizing a monomer component consisting of the following: weight ratio of inner layer (hard polymer layer) / intermediate layer (elastic polymer layer) / outer layer (hard polymer layer) The rubber particles having a spherical three-layer structure obtained by an emulsion polymerization method having a ratio of 35/45/20 were used. The average particle diameter of the elastic polymer part (the elastic polymer layer as the intermediate layer and the hard polymer layer as the inner layer) in the acrylic rubber particles was measured by the following method to be 220 nm.

[Method for measuring average particle diameter of elastic polymer part in acrylic rubber particles]
Acrylic rubber particles are mixed with a methacrylic resin to form a film, the resulting film is cut into a suitable size, and the slice is immersed in an aqueous 0.5% ruthenium tetroxide solution at room temperature for 15 hours. The coalesced layer was stained. Further, after cutting the sample to a thickness of about 80 nm using a microtome, the photograph was taken with a transmission electron microscope, and 100 dyed elastic polymer layers were randomly selected from the photograph, After calculating each diameter, the average value was calculated | required and this was made into the average particle diameter of an elastic polymer part. This average particle diameter is the average particle diameter of the acrylic rubber particles excluding the hard polymer layer as the outer layer (that is, the elastic polymer layer as the intermediate layer and the hard polymer layer as the inner layer).

Example 1
First, as a material for forming the layer (A), 80 parts of methacrylic resin pellets and 20 parts of acrylic rubber particles are mixed with a super mixer and melt kneaded using a twin screw extruder (manufactured by Toshiba Machine Co., Ltd.). By doing this, the methacrylic resin composition was obtained as a pellet. On the other hand, methacrylic resin pellets were used as the layer (B) forming material.

  Next, the pellet of the methacrylic resin composition used as the forming material of the layer (A) using a 65 mmφ single screw extruder (manufactured by Toshiba Machine Co., Ltd.) is used using a 45 mmφ single screw extruder (manufactured by Toshiba Machine Co., Ltd.). A methacrylic resin pellet as a forming material of the layer (B) is melted, and a layer formed of a methacrylic resin on one surface of the layer (A) formed of the methacrylic resin composition by a feed block method ( These layers are melt-laminated and integrated so that B) is laminated, extruded through a T-type die with a set temperature of 265 ° C., and the resulting film-like product is placed between a pair of metal rolls with a smooth surface And then molded. Thus, a multilayer film (layer (A) (thickness: 80 μm) / layer (B) (thickness: 45 μm)) of two types and two layers in which the layer (B) was laminated on one surface of the layer (A) was obtained. The haze value of this multilayer film was 1.5%.

Using the uniaxial stretching machine (manufactured by Instron), the obtained multilayer film is stretched at a stretching temperature of 150 ° C. and a stretching speed of 2.0 m / min, and the stretching ratio in the mechanical flow direction of the film becomes 2.0 times. Thus, a multilayer stretched film having a total thickness of 35 μm in a two-layer / two-layer configuration was obtained.
About the obtained stretched film, the total light transmittance (Tt), the measurement of haze value, and transparency at the time of bonding were evaluated. The results are shown in Table 1.

(Comparative Example 1)
The pellets of the methacrylic resin composition used as the material for forming the layer (A) in Example 1 were melted using a 65 mmφ single screw extruder (manufactured by Toshiba Machine Co., Ltd.) and passed through a T-type die having a set temperature of 265 ° C The film-like product obtained by extrusion was sandwiched between a pair of metal rolls having a smooth surface and molded. In this way, a single layer film (thickness: 125 μm) having a single layer configuration of only one layer (A) was obtained. The haze value of this single layer film was 0.8%.
The obtained single-layer film was stretched in the same manner as in Example 1 to obtain a single-layer stretched film having a one-layer / one-layer configuration and an overall thickness of 35 μm.
About the obtained stretched film, the total light transmittance (Tt), the measurement of haze value, and transparency at the time of bonding were evaluated. The results are shown in Table 1.

Claims (16)

  A layer (B) made of the thermoplastic resin composition (b) not containing acrylic rubber particles is formed on at least one surface of the layer (A) made of methacrylic resin composition (a) containing methacrylic resin and acrylic rubber particles. A multilayer stretched film for laminating a molded body that is laminated, and is bonded to the molded body so that the layer (B) is present on the surface of the film-formed molded body after lamination. Multilayer stretched film.   The methacrylic resin composition (a) contains methacrylic resin and acrylic rubber particles in a ratio of methacrylic resin: acrylic rubber particles (weight ratio) = 20: 80 to 97: 3. Multi-layer stretched film.   The multilayer stretched film according to claim 1 or 2, wherein a multilayer film obtained by coextrusion molding of the methacrylic resin composition (a) and the thermoplastic resin composition (b) is stretched.   The multilayer stretched film according to claim 3, wherein the stretching is biaxial stretching.   The multilayer stretched film according to claim 3 or 4, wherein a stretching ratio in the stretching direction in the stretching is 1.1 to 3.0 times.   The multilayer stretched film according to any one of claims 1 to 5, wherein the entire thickness is 10 to 250 µm.   The thermoplastic resin composition (b) comprises at least one selected from the group consisting of an acrylic resin, a polystyrene resin, a polycarbonate resin, an ABS resin, and an aliphatic polyester resin as a resin component. A multilayer stretched film as described in 1.   The methacrylic resin contained in the methacrylic resin composition (a) is composed of 50 to 100% by weight of alkyl methacrylate and 50 to 100% by weight of alkyl methacrylate, with the total of alkyl methacrylate, alkyl acrylate, and other monomers being 100% by weight. The multilayer stretched film according to any one of claims 1 to 7, which is a polymer obtained by polymerizing 0 to 50% by weight of an acid alkyl and 0 to 49% by weight of a monomer other than these.   The elastic polymer part in the acrylic rubber particles has an alkyl acrylate in the range of 50 to 99.% with the total of alkyl acrylate, alkyl methacrylate, monofunctional monomer other than these, and polyfunctional monomer being 100% by weight. 9% by weight, 0 to 49.9% by weight of alkyl methacrylate, 0 to 49.9% by weight of monofunctional monomer, and 0.1 to 10% by weight of polyfunctional monomer. The multilayer stretched film according to claim 1, wherein the elastic polymer part has an average particle size of 40 to 800 nm.   The acrylic rubber particles are formed on the outer side of the elastic polymer part by adding alkyl methacrylate, alkyl acrylate, monofunctional monomer other than these, and polyfunctional monomer as a total of 100% by weight. Hard weight obtained by polymerizing 50 to 100% by weight, alkyl acrylate 0 to 50% by weight, monofunctional monomer 0 to 50% by weight, and polyfunctional monomer 0 to 10% by weight. The multilayer stretched film according to claim 9, which is a particle having a layer composed of a coalescence.   The elastic polymer part in the acrylic rubber particles is composed of alkyl methacrylate, alkyl acrylate, monofunctional monomer other than these, and polyfunctional monomer in an amount of 100% by weight, and alkyl methacrylate is 70 to 100% by weight. %, A hard polymer obtained by polymerizing 0-30 wt% of an alkyl acrylate, 0-30 wt% of a monofunctional monomer, and 0-10 wt% of a polyfunctional monomer. The multilayer stretched film according to claim 9 or 10.   The multilayer stretched film according to any one of claims 1 to 11, wherein a layer (B) is laminated on one surface of the layer (A), and the layer (A) side surface is added to the multilayer stretched film. A decorative film characterized by being decorated.   The multilayer stretched film according to any one of claims 1 to 11, wherein the layer (B) is laminated on both surfaces of the layer (A), and the multilayer stretched film is decorated on either surface. A decorative film characterized by being applied.   A thermoplastic resin sheet is laminated on the surface on the decorating side of the decorating film according to claim 12 or 13, wherein the decorating sheet is characterized in that:   A decorative molded product, wherein a thermoplastic resin is injection-molded on the surface of the decorative film of the decorative film according to claim 12 or 13.   A decorative molded product, wherein a thermoplastic resin is injection-molded on a surface of the decorative sheet according to claim 14 on the side of the thermoplastic resin sheet.