Resin composition, composite molded body, decorative film, and method for producing composite molded body

Abstract

To provide means for obtaining a composite molded body that can form a coating film with good adhesion on a resin molded body containing polypropylene or the like without application of a primer, while maintaining high impact resistance.SOLUTION: A resin composition containing (A) 20 to 60 mass% of a hydroxyl group-containing polypropylene, (B) 0 to 50 mass% of a polypropylene (excluding those corresponding to (A) the hydroxyl group-containing polypropylene), and (C) 30 to 80 mass% of an ethylene-α-olefin copolymer (wherein a total mass of the resin composition is 100 mass%).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition. [Background technology]

[0002] Resin molded articles containing polypropylene, etc., are used as automobile parts such as bumpers. In such applications, the resin molded articles are generally painted, but because polypropylene molded articles have low paint film adhesion, it has been common to apply a primer to the resin molded articles before forming a paint film in order to improve paint film adhesion (see, for example, Patent Document 1). If the process of using primer can be omitted, it will not only reduce costs but also contribute to reducing VOCs and energy consumption, so there is a demand for paint components that can form good coatings without using primer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-107537 Summary of the Invention [Problem to be solved by the invention]

[0004] Under these circumstances, the problem that the present invention aims to solve is to provide a means for forming a coating film with good adhesion on a resin molded body containing polypropylene or the like without the need for application of a primer, and for obtaining a composite molded body with high impact resistance. [Means for solving the problem]

[0005] In view of the above background, the present inventors have conducted extensive research and found that a resin composition having a specific composition can solve the above problems, thereby completing the present invention. That is, the present invention provides: [1] (A) 20 to 60 mass% of hydroxyl group-containing polypropylene, (B) 0 to 50 mass% of polypropylene (excluding those corresponding to (A) hydroxyl group-containing polypropylene), and (C) a resin composition containing 30 to 80 mass% of an ethylene-α-olefin copolymer (where the total mass of the resin composition is 100 mass%), Regarding.

[0006] Below, [2] to

[12] are each preferred aspects or embodiments of the present invention. [2] The resin composition according to [1], wherein the hydroxyl group-containing polypropylene (A) is a 2-hydroxyethyl methacrylate-modified polypropylene. [3] The resin composition according to [1] or [2], comprising (B) polypropylene, wherein (B) polypropylene is (B3) a heterophasic propylene polymerization material. [4] (C) The composition according to any one of [1] to [3], wherein the ethylene-α-olefin copolymer has a crystalline melting peak having a heat of crystalline melting of more than 1.0 J / g in a temperature range of −100°C to 200°C on a curve obtained by differential scanning calorimetry. [5] (C) The composition according to any one of [1] to [3], wherein the ethylene-α-olefin copolymer has a crystalline melting peak having a heat of crystalline melting of 10.0 J / g or more in the temperature range of −100°C to 200°C on a curve obtained by differential scanning calorimetry. [6] A resin layer having a thickness of 1 mm or less, comprising the composition according to any one of [1] to [5]. [7] A composite molded body formed by laminating (1) a coating film, (2) an adhesive layer, and (3) a polyolefin molded body in this order, wherein (2) the adhesive layer is constituted by the resin layer described in [6]. [8] (1) The composite molding according to [7], wherein the coating film contains a water-based paint. [9] (3) The composite molded body according to [7] or [8], wherein the polyolefin molded body contains polypropylene.

[10] The composite molded body according to any one of [7] to [9], which is an automotive part.

[11] A decorative film comprising (1) a coating film and (2) an adhesive layer laminated in this order, wherein the adhesive layer (2) is constituted by the resin layer described in [6].

[12] i) (3) A step of arranging the polyolefin molded body and the decorative film according to

[11] so that at least a part of the surface of the polyolefin molded body (3) contacts at least a part of the adhesive layer (2) of the decorative film; ii) (3) A step of heating and bonding the polyolefin molded body and the decorative film; A method for producing a composite molded body having the above-mentioned features.

[13] A two-layer structure comprising (2) an adhesive layer and (3) a polyolefin molded body laminated in this order, wherein the (2) adhesive layer is constituted by the resin layer described in [6].

[14] i') providing a two-layer structure according to

[13] , and ii') forming a coating film (1) on at least a portion of the surface of the adhesive layer (2) of the two-layer structure obtained in step i'; A method for producing a composite molded body having the above-mentioned features. [Effects of the Invention]

[0007] According to the present invention, a method can be provided for forming a coating film with good adhesion on a resin molded article containing polypropylene, etc., without the need for application of a primer. Furthermore, by obtaining a composite molded article using the method described in the present invention, a composite molded article with excellent impact resistance can be obtained. [Brief explanation of the drawings]

[0008] [Figure 1]1A and 1B are schematic diagrams illustrating a method for producing a composite molded body according to one embodiment of the present invention. [Figure 2] 5(a) to 5(d) are schematic diagrams illustrating a method for producing a composite molded body according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention provides (A) 20 to 60 mass% of hydroxyl group-containing polypropylene, (B) 0 to 50 mass% of polypropylene (excluding those corresponding to (A) hydroxyl group-containing polypropylene), and (C) a resin composition containing 30 to 80% by mass of an ethylene-α-olefin copolymer (where the total mass of the resin composition is taken as 100% by mass). That is, the resin composition of the present invention contains, as essential components, predetermined amounts of (A) hydroxyl-containing polypropylene and (C) ethylene-α-olefin copolymer, and may further contain, as an optional component, a predetermined amount or less of (B) polypropylene (excluding that which corresponds to (A) hydroxyl-containing polypropylene). Therefore, the resin composition of the present invention may consist only of (A) hydroxyl-containing polypropylene and (C) ethylene-α-olefin copolymer (and (B) polypropylene, if present) as essential components, or it may contain other components in addition to (A) hydroxyl-containing polypropylene and (C) ethylene-α-olefin copolymer (and (B) polypropylene, if present). Each of the above components will be explained below.

[0010] (A) Hydroxyl group-containing polypropylene The hydroxyl group-containing polypropylene (A) constituting the resin composition of the present invention is not particularly limited as long as it is a polymer whose main chain is mainly composed of structural units derived from propylene and has at least one hydroxyl group. Here, "whose main chain is mainly composed of structural units derived from propylene" means that the main chain contains more than 50% by mass and not more than 100% by mass of structural units derived from propylene. There are no particular restrictions on the molecular weight or viscosity of (A) the hydroxyl group-containing polypropylene, but the intrinsic viscosity [η] measured in decalin at 135°C is preferably 0.8 to 2.0 dl / g, more preferably 0.8 to 1.8 dl / g, and even more preferably 0.9 to 1.5 dl / g. There are no particular limitations on the melting point of (A) hydroxyl group-containing polypropylene, but the melting point as detected by a differential scanning calorimeter is preferably 150 to 168°C, more preferably 152 to 167°C. An intrinsic viscosity [η] measured in decalin at 135°C of 0.8 dL / g or more is preferable from the viewpoint of impact resistance, etc., and an intrinsic viscosity [η] of 2.0 dL / g or less is preferable from the viewpoint of realizing good fluidity and excellent moldability, etc. Furthermore, it is preferable that the melting point as detected by a differential scanning calorimeter is 150° C. or higher from the viewpoint of realizing high rigidity and heat-resistant rigidity.

[0011] While the method for producing (A) hydroxyl-containing polypropylene is not particularly limited, a preferred production method is a method of melt-kneading a mixture containing a polypropylene resin, such as (B) polypropylene described below, with a hydroxyl-containing monomer and an organic peroxide. The polypropylene resin used in the melt-kneading method is preferably an ultra-high molecular weight crystalline polypropylene resin having a melting point measured by a differential scanning calorimeter of preferably 150 to 168°C and an intrinsic viscosity [η] measured in decalin at 135°C of preferably 5 to 15 dL / g, more preferably 5.5 to 12 dL / g. The amounts of the hydroxyl-containing monomer and organic peroxide used are preferably in the range of 0.3 to 10 parts by weight of the hydroxyl-containing monomer and 0.001 to 10 parts by weight of the organic peroxide per 100 parts by weight of the polypropylene resin.

[0012] Preferred examples of hydroxyl group-containing monomers used in the production of (A) hydroxyl group-containing polypropylene include (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, glycerin mono(meth)acrylate, pentaerythritol mono(meth)acrylate, trimethylolpropane (meth)acrylate, tetramethylolethane mono(meth)acrylate, butanediol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, and 2-(6-hydroxyhexanoyloxy)ethyl acrylate. "(Meth)acryl" means "acrylate" and / or "methacrylate."

[0013] Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate are preferred, and 2-hydroxyethyl methacrylate is particularly preferred. The hydroxyl group-containing monomers may be used alone or in combination of two or more.

[0014] As the organic peroxide, known organic peroxides can be used without any particular limitation. Specific examples of preferred organic peroxides include peroxyketals such as 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)octane, n-butyl-4,4-bis(tert-butylperoxy)valerate, and 2,2-bis(tert-butylperoxy)butane; di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, α, Dialkyl peroxides such as α'-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3; acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,5-dichlorobenzoyl peroxide, m -Diacyl peroxides such as trioyl peroxide; tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxylaurate, tert-butyl peroxybenzoate, di-tert-butyl peroxyisophthalate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, tert-butyl peroxymaleic acid, tert-butyl peroxyisopropyl carbonate peroxyesters such as di(2-ethylhexyl)peroxydicarbonate and di(3-methyl-3-methoxybutyl)peroxydicarbonate; and hydroperoxides such as tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide.Among these, benzoyl peroxide, m-trioyl peroxide, tert-butylperoxy-2-ethylhexanoate, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butyl peroxybenzoate, etc. These may be used alone or in combination of two or more.

[0015] The hydroxyl group-containing polypropylene (A) can be produced by various known methods for mixing resins together or resins with solid or liquid additives. A preferred example is a method in which all or some of the components are combined and mixed separately using a Henschel mixer, ribbon blender, blender, or the like to form a uniform mixture, followed by kneading the resulting mixture. Kneading can be performed using a wide variety of conventional kneading methods, such as a Banbury mixer, a plastomill, a Brabender plastograph, or a single- or twin-screw extruder. The temperature during kneading in the kneader (e.g., the cylinder temperature in the case of an extruder) is, for example, 100 to 300°C, preferably 160 to 250°C. A temperature of 100°C or higher improves the grafting amount, while a temperature of 300°C or lower effectively suppresses decomposition of the resin, etc. The kneading time is typically 0.1 to 30 minutes, preferably 0.5 to 5 minutes. A kneading time of 0.1 minutes or more allows a sufficient amount of grafting to be obtained, and a kneading time of 30 minutes or less allows decomposition of the resin to be effectively suppressed.

[0016] There are no particular restrictions on the graft modification rate of (A) hydroxyl group-containing polypropylene, but from the standpoint of achieving excellent coating film adhesion, it is preferably 0.5% or more, and particularly preferably 0.7% or more. On the other hand, from the viewpoint of suppressing decomposition of polypropylene, the graft modification rate of (A) hydroxyl group-containing polypropylene is preferably 3.0% or less, and particularly preferably 2.0% or less. The graft modification rate is defined by the following formula: Graft modification rate (%) = 100 × (mass of grafted chains) / (mass of base material) In the case of (A) hydroxyl-containing polypropylene, the "mass of graft chains" in the formula is the total mass of side chains containing hydroxyl groups, and when (A) hydroxyl-containing polypropylene is produced by the above-mentioned production method, it is the total mass of the hydroxyl-containing monomers used in the production method that are grafted to the main chain (when substantially all of the hydroxyl-containing monomers are grafted to the main chain, it is the total mass of the hydroxyl-containing monomers used in the production method). Similarly, in the case of (A) hydroxyl-containing polypropylene, the "mass of base material" in the formula is the mass of the polypropylene main chain, and when (A) hydroxyl-containing polypropylene is produced by the above-mentioned production method, it is the total mass of the polypropylene resin used in the production method. The graft modification rate of (A) the hydroxyl group-containing polypropylene can be measured by nuclear magnetic resonance (NMR) measurement. The graft modification rate of (A) the hydroxyl group-containing polypropylene can be appropriately adjusted by selecting and adjusting the amounts of the hydroxyl group-containing monomer and organic peroxide used, the conditions of the graft modification step such as kneading, and the like.

[0017] There are no particular limitations on the MFR of (A) hydroxyl group-containing polypropylene, but from the viewpoint of moldability and the like, the MFR measured at 230°C under a load of 2.16 kg is preferably 0.5 g / 10 min or more, more preferably 1 g / 10 min or more, and particularly preferably 5 g / 10 min or more. On the other hand, from the viewpoint of tensile strength, the MFR of (A) hydroxyl group-containing polypropylene measured at 230° C. under a load of 2.16 kg is preferably 1000 g / 10 min or less, and particularly preferably 500 g / 10 min or less. The MFR of (A) the hydroxyl group-containing polypropylene can be adjusted appropriately by selecting and adjusting the type and physical properties of the polypropylene used in its production, the conditions of the above-mentioned graft modification step, and the like.

[0018] The hydroxyl group-containing polypropylene (A) may contain various additives such as phenolic, sulfuric, or phosphorus-based antioxidants, lubricants, antistatic agents, dispersants, copper inhibitors, neutralizing agents, foaming agents, plasticizers, anti-foaming agents, flame retardants, crosslinking agents, flow improvers such as peroxides, ultraviolet absorbers, and light stabilizers.

[0019] (B) Polypropylene The (B) polypropylene (excluding those falling under the category of (A) hydroxyl group-containing polypropylene) preferably used in the present invention is not particularly limited as long as the main chain is composed mainly of structural units derived from propylene and is a polymer that does not fall under the category of (A) hydroxyl group-containing polypropylene. Therefore, (B) polypropylene is a polymer whose main chain is composed mainly of structural units derived from propylene and does not contain hydroxyl groups. Here, "the main chain is composed mainly of structural units derived from propylene" means that the main chain is composed of more than 50% by mass and not more than 100% by mass of structural units derived from propylene. The polypropylene (B) preferably contained in the resin composition of the present invention (hereinafter, sometimes referred to as component (B)) is a propylene (co)polymer having more than 50 mass % and not more than 100 mass % of structural units derived from propylene, as described above. Component (B) may also have structural units derived from a monomer other than propylene.

[0020] Examples of the monomer other than propylene include ethylene and α-olefins having 4 or more carbon atoms, and ethylene and α-olefins having 4 or more and 20 or less carbon atoms are preferred. Examples of the α-olefins having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene, and 2,2,4-trimethyl-1-pentene. The proportion of structural units derived from propylene, the proportion of structural units derived from ethylene, and the proportion of structural units derived from at least one monomer selected from the group consisting of α-olefins having 4 or more carbon atoms in (B) polypropylene can be determined by infrared spectroscopy. More specifically, the infrared absorption spectrum of (B) polypropylene is measured using an infrared spectrophotometer, and the measurements can be performed according to the method described in "Characterization of Polyethylene by Infrared Absorption Spectroscopy (Takayama, Usami et al.)" or "Die Makromolekulare Chemie, 177, 461 (1976) (McRae, MA, Madam S, WF et al.)."

[0021] Examples of (B) polypropylene include (B1) propylene homopolymer, (B2) propylene random copolymer, (B3) heterophasic propylene polymer material, etc. The molded article according to the present invention may contain only one type of (B) polypropylene, or may contain two or more types.

[0022] Preferable examples of the (B2) propylene random copolymer include: (B2-1) A propylene-ethylene random copolymer having a proportion of structural units derived from propylene of 90% by mass or more and 99.5% by mass or less and a proportion of structural units derived from ethylene of 0.5% by mass or more and 10% by mass or less (the total amount of structural units derived from propylene and structural units derived from ethylene is taken as 100% by mass); (B2-2) A propylene-ethylene-α-olefin random copolymer having a proportion of propylene units of 81% by mass or more and 99% by mass or less, a proportion of structural units derived from ethylene of 0.5% by mass or more and 9.5% by mass or less, and a proportion of structural units derived from an α-olefin having 4 to 10 carbon atoms of 0.5% by mass or more and 9.5% by mass or less (the total amount of structural units derived from propylene, structural units derived from ethylene, and structural units derived from an α-olefin having 4 to 10 carbon atoms is taken as 100% by mass); (B2-3) Propylene-α-olefin random copolymers in which the proportion of structural units derived from propylene is 90% by mass or more and 99.5% by mass or less, and the proportion of structural units derived from α-olefins having from 4 to 10 carbon atoms is 0.5% by mass or more and 10% by mass or less (wherein the total amount of structural units derived from propylene and structural units derived from α-olefins having from 4 to 10 carbon atoms is taken as 100% by mass). Examples of the α-olefins having 4 to 10 carbon atoms in the above (B2-1) and (B2-2) include linear α-olefins such as 1-butene, 1-pentene, 1-hexene, 1-octene, and 1-decene; and branched α-olefins such as 3-methyl-1-butene and 3-methyl-1-pentene. In preparing the above (B2-1) and (B2-2), the α-olefins having 4 to 10 carbon atoms may be used alone or in combination of two or more.

[0023] The (B1) propylene homopolymer and the (B2) propylene random copolymer can be produced by polymerizing propylene (and other monomers, if necessary) in the presence of a Ziegler-Natta catalyst or a complex catalyst such as a metallocene complex or a nonmetallocene complex. Examples of the polymerization method include slurry polymerization, solution polymerization, bulk polymerization, and gas phase polymerization.

[0024] In this specification, the term "heterophagic propylene polymer material" refers to a polymer (I) having structural units derived from propylene in an amount of more than 80% by mass and not more than 100% by mass (where the total mass of the polymer is taken as 100% by mass) (hereinafter, sometimes simply referred to as "polymer (I)"). The term "copolymer (II)" refers to a mixture having a structure in which copolymer (II) (where the total mass of the copolymer is taken as 100 mass%) (hereinafter simply referred to as "copolymer (II)") having 20 mass % or more and 90 mass % or less of structural units derived from ethylene and structural units derived from at least one monomer selected from the group consisting of α-olefins having 3 or more carbon atoms is dispersed in a matrix of (II). The heterophasic propylene polymer material (B3) as component (B) contains propylene-derived structural units in an amount of 50% by mass or more, with the total amount of the heterophasic propylene polymer material being 100% by mass. The amount of polymer (I) contained in the (B3) heterophasic propylene polymerization material is preferably 70% by mass to 90% by mass, more preferably 75% by mass to 90% by mass (where the total amount of the (B3) heterophasic propylene polymerization material is 100% by mass). The amount of copolymer (II) contained in the (B3) heterophasic propylene polymerization material is preferably 10% by mass to 30% by mass, more preferably 10% by mass to 25% by mass (where the total amount of the (B3) heterophasic propylene polymerization material is 100% by mass).

[0025] Examples of the α-olefin having 3 or more carbon atoms in the copolymer (II) include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene, 2,2,4-trimethyl-1-pentene, etc. The α-olefin having 3 or more carbon atoms is preferably an α-olefin having 3 to 20 carbon atoms, more preferably an α-olefin having 3 to 10 carbon atoms, and even more preferably propylene, 1-butene, 1-hexene, or 1-octene. In the copolymer (II), the α-olefins having 3 or more carbon atoms may be used alone or in combination of two or more kinds.

[0026] The proportion of structural units derived from ethylene contained in copolymer (II) is preferably 22% by mass to 80% by mass, more preferably 25% by mass to 70% by mass, and even more preferably 27% by mass to 60% by mass (wherein the total amount of structural units derived from at least one selected from the group consisting of α-olefins having 3 or more carbon atoms and structural units derived from ethylene is 100% by mass). The proportion of structural units derived from at least one monomer selected from the group consisting of α-olefins having 3 or more carbon atoms contained in copolymer (II) is preferably 20% by mass to 78% by mass, more preferably 30% by mass to 75% by mass, and even more preferably 40% by mass to 73% by mass (wherein the total amount of structural units derived from at least one monomer selected from the group consisting of α-olefins having 3 or more carbon atoms and structural units derived from ethylene is 100% by mass).

[0027] Examples of the copolymer (II) include a propylene-ethylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, an ethylene-1-octene copolymer, a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, and a propylene-ethylene-1-octene copolymer, among which a propylene-ethylene copolymer or a propylene-ethylene-1-butene copolymer is preferred. The copolymer (II) is usually a random copolymer.

[0028] A method for producing the (B3) heterophasic propylene polymerized material as component (B) includes multistage polymerization of monomers including propylene and ethylene in the presence of a polymerization catalyst. For example, in a first polymerization step, a propylene-containing monomer is polymerized in the presence of the polymerization catalyst to produce polymer (I), and in a second polymerization step, ethylene and at least one monomer selected from the group consisting of α-olefins having 3 or more carbon atoms are copolymerized in the presence of polymer (I) obtained in the first polymerization step to produce copolymer (II). Examples of polymerization catalysts used in producing the (B3) heterophasic propylene polymerized material include Ziegler catalysts, Ziegler-Natta catalysts, catalysts consisting of a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring and an alkylaluminoxane, catalysts consisting of a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that reacts with the transition metal compound to form an ionic complex, and an organoaluminum compound. In addition, a prepolymerization catalyst may be used in the presence of the polymerization catalyst. Examples of the prepolymerization catalyst include those described in JP-A Nos. 61-218606, 61-287904, 5-194685, 7-216017, 9-316147, 10-212319, and 2004-182981.

[0029] Polymerization methods for producing the (B3) heterophasic propylene polymer material as component (B) include bulk polymerization, solution polymerization, slurry polymerization, and gas-phase polymerization. Examples of inert hydrocarbon solvents used in solution polymerization and slurry polymerization include propane, butane, isobutane, pentane, hexane, heptane, and octane. Two or more of these polymerization methods may be combined, and either batch or continuous polymerization is possible. Preferred polymerization methods for producing the (B2) heterophasic propylene polymer material are continuous gas-phase polymerization and bulk-gas-phase polymerization, in which bulk polymerization and gas-phase polymerization are performed continuously.

[0030] The melt flow rate (MFR) of (B) polypropylene, measured in accordance with JIS K7210 at a temperature of 230°C and a load of 21.18 N (2.16 kg), is not particularly limited, but from the viewpoint of bonding to other components, it is preferably 0.3 g / 10 min or more and 200 g / 10 min or less, and more preferably 2.5 g / 10 min or more and 150 g / 10 min or less.

[0031] (B) The intrinsic viscosity (hereinafter, [η cxis ]) is not particularly limited, but is preferably 0.1 dl / g or more and 6.0 dl / g or less, more preferably 0.3 dl / g or more and 5.0 dl / g or less, and even more preferably 0.3 dl / g or more and 3.1 dl / g or less. The intrinsic viscosity can be determined according to the following procedure: Using an Ubbelohde viscometer, the reduced viscosity is measured in tetralin at 135°C, and the intrinsic viscosity is calculated from the reduced viscosity by extrapolation according to the calculation method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (published by Kyoritsu Shuppan Co., Ltd. in 1982). The CXS and CXIS fractions are obtained by the following method. (B) Approximately 5 g of polypropylene is completely dissolved in 500 ml of boiling xylene. The resulting xylene solution is gradually cooled to 20°C and conditioned at 20°C for at least 4 hours, and the precipitate and solution are separated by filtration. The precipitate is the CXIS fraction. The substance obtained by removing the solvent from the solution is the xylene-soluble fraction at 20°C (CXS fraction).

[0032] As the (B) polypropylene, (B1) propylene homopolymer, (B2) propylene random copolymer such as propylene-ethylene random copolymer or propylene-ethylene-1-butene random copolymer, or (B3) heterophasic propylene polymerization material are preferred, (B1) propylene homopolymer or (B3) heterophasic propylene polymerization material are more preferred, and (B3) heterophasic propylene polymerization material is particularly preferred.

[0033] (C) Ethylene-α-olefin copolymer The ethylene-α-olefin copolymer (C) constituting the resin composition of the present invention may be any copolymer having structural units derived from ethylene and structural units derived from an α-olefin, and there are no other limitations thereon. However, it is preferably an ethylene copolymer having 50% by mass or more and 99% by mass or less of structural units derived from ethylene and structural units derived from at least one monomer selected from the group consisting of α-olefins having from 3 to 10 carbon atoms (wherein the total amount of the ethylene copolymer is taken as 100% by mass). The ethylene-α-olefin copolymer (C) is preferably a random copolymer. The (C) ethylene-α-olefin copolymer may have structural units derived from a monomer other than ethylene and an α-olefin.

[0034] Examples of the α-olefins having 3 to 10 carbon atoms include propylene, 1-butene, 2-methylpropene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. In preparing the (C) ethylene-α-olefin copolymer, the α-olefins having 3 to 10 carbon atoms may be used alone or in combination of two or more. More preferred examples of the structural unit derived from at least one selected from the group consisting of α-olefins having 3 to 10 carbon atoms include a structural unit derived from propylene, a structural unit derived from 1-butene, and a structural unit derived from 1-octene.

[0035] The proportion of structural units derived from ethylene in (C) ethylene-α-olefin copolymer is preferably from 50 to 99% by mass, more preferably from 55 to 90% by mass, and particularly preferably from 60 to 85% by mass (where the total amount of (C) ethylene-α-olefin copolymer is taken as 100% by mass). The proportion of structural units derived from at least one selected from the group consisting of α-olefins having from 3 to 10 carbon atoms in (C) ethylene-α-olefin copolymer is preferably from 1 to 50% by mass, more preferably from 10 to 45% by mass, and particularly preferably from 15 to 40% by mass (where the total amount of (C) ethylene-α-olefin copolymer is taken as 100% by mass).

[0036] The proportion of ethylene-derived structural units in (C) ethylene-α-olefin copolymer and the proportion of structural units derived from at least one monomer selected from the group consisting of α-olefins having from 3 to 10 carbon atoms can be determined by infrared spectroscopy. Specifically, the infrared absorption spectrum of (C) ethylene-α-olefin copolymer is measured using an infrared spectrophotometer, and the proportion of ethylene-derived structural units and the proportion of structural units derived from at least one monomer selected from the group consisting of α-olefins having from 3 to 10 carbon atoms can be calculated according to the method described in "Characterization of Polyethylene by Infrared Absorption Spectroscopy (Takayama, Usami et al.)" or "Die Makromolekulare Chemie, 177, 461 (1976) (McRae, MA, Madam S, WF et al.)." The proportion of ethylene-derived structural units in components (C-1) and (C-2) described below and the proportion of structural units derived from at least one monomer selected from the group consisting of α-olefins having from 3 to 10 carbon atoms can also be determined in a similar manner.

[0037] The (C) ethylene-α-olefin copolymer may have structural units derived from at least one monomer other than ethylene and α-olefins having from 3 to 10 carbon atoms. Examples of such other monomers include conjugated dienes having from 4 to 8 carbon atoms, such as 1,3-butadiene, 2-methyl-1,3-butadiene, 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene; non-conjugated dienes having from 5 to 15 carbon atoms, such as dicyclopentadiene, 5-ethylidene-2-norbornene, 1,4-hexadiene, 1,5-dicyclooctadiene, 7-methyl-1,6-octadiene, and 5-vinyl-2-norbornene; vinyl carboxylic acid esters, such as vinyl acetate; unsaturated carboxylic acid esters, such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, and ethyl methacrylate; and unsaturated carboxylic acids, such as acrylic acid and methacrylic acid. The other monomer is preferably a non-conjugated diene having from 5 to 15 carbon atoms, more preferably 5-ethylidene-2-norbornene or dicyclopentadiene. (C) The ethylene-α-olefin copolymer may contain two or more types of structural units derived from the other monomer.

[0038] When the (C) ethylene-α-olefin copolymer contains structural units derived from at least one monomer other than ethylene and an α-olefin having from 3 to 10 carbon atoms, the proportion of structural units derived from the other monomer is preferably 30% by mass or less, more preferably 20% by mass or less (where the total mass of the (C) ethylene-α-olefin copolymer is taken as 100% by mass). The proportion of structural units derived from the other monomer can be determined by infrared spectroscopy. Specifically, an infrared spectrophotometer is used to measure the peak intensity of the peak derived from the other monomer in the (C) ethylene-α-olefin copolymer, and the proportion of structural units derived from the other monomer in the (C) ethylene-α-olefin copolymer is calculated from the peak intensity.

[0039] Examples of (C) ethylene-α-olefin copolymers include ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-1-octene copolymers, ethylene-propylene-1-butene copolymers, ethylene-propylene-1-hexene copolymers, ethylene-propylene-1-octene copolymers, ethylene-propylene-5-ethylidene-2-norbornene copolymers, ethylene-propylene-dicyclopentadiene copolymers, ethylene-propylene-1,4-hexadiene copolymers, and ethylene-propylene-5-vinyl-2-norbornene copolymers. The ethylene-based copolymers as component (C) may be used alone or in combination of two or more. Ethylene-octene copolymers, ethylene-propylene copolymers, and the like are preferably used as component (C).

[0040] There is no particular limitation on the density of the (C) ethylene-α-olefin copolymer, but from the viewpoints of tensile strength and suppression of stickiness of the product, it is 0.830 g / cm 3 It is preferable that the concentration is 0.840 g / cm or more. 3 More preferably, it is 0.850 g / cm or more. 3 More preferably, it is equal to or greater than this. On the other hand, from the viewpoint of product flexibility, impact resistance, etc., the density of (C) ethylene-α-olefin copolymer is 0.900 g / cm 3 Preferably, it is 0.890 g / cm or less. 3 More preferably, it is 0.880 g / cm or less. 3 It is particularly preferred that: The density of the (C) ethylene-α-olefin copolymer can be adjusted appropriately by selecting and adjusting the type and proportion of structural units derived from α-olefin, the polymerization conditions for the (C) ethylene-α-olefin copolymer, etc.

[0041] There are no particular limitations on the MFR of the (C) ethylene-α-olefin copolymer, but from the viewpoint of moldability and the like, the MFR measured at 190°C under a load of 2.16 kg is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, and particularly preferably 0.5 g / 10 min or more. On the other hand, from the viewpoint of impact resistance and the like, the MFR of (C) ethylene-α-olefin copolymer measured at 190°C under a load of 2.16 kg is preferably 30 g / 10 min or less, more preferably 10 g / 10 min or less, and particularly preferably 5 g / 10 min or less. The MFR of the ethylene-α-olefin copolymer (C) can be appropriately adjusted by adjusting the molecular weight and other parameters through the polymerization conditions and other parameters of the ethylene-α-olefin copolymer (C).

[0042] There are no particular limitations on the melting point of the ethylene-α-olefin copolymer (C), but it is particularly preferred that it be 0° C. or higher in order to prevent the product from becoming sticky. On the other hand, from the viewpoint of the flexibility and impact resistance of the product, the melting point of the ethylene-α-olefin copolymer (C) is preferably 100°C or lower, more preferably 80°C or lower, and particularly preferably 70°C or lower. The melting point of the (C) ethylene-α-olefin copolymer can be measured by DSC (differential scanning calorimetry). The melting point of the ethylene-α-olefin copolymer (C) can be adjusted appropriately by adjusting the molecular structure, crystallinity, etc. of the ethylene-α-olefin copolymer (C) through the type and proportion of structural units derived from α-olefin, polymerization conditions, etc.

[0043] There are no particular limitations on the heat of crystalline fusion of the (C) ethylene-α-olefin copolymer, but from the viewpoint of suppressing stickiness of the product, it is preferable that the ethylene-α-olefin copolymer has a crystalline fusion peak with a heat of crystalline fusion exceeding 1.0 J / g in the temperature range of -100°C to 200°C on the curve obtained by differential scanning calorimetry. The presence of a crystalline melting peak with a heat of crystalline melting exceeding 1.0 J / g within the above temperature range indicates that the ethylene-α-olefin copolymer (C) is crystalline. The crystalline heat of fusion of the ethylene-α-olefin copolymer (C) is more preferably 10.0 J / g or more. The heat of crystalline fusion of the (C) ethylene-α-olefin copolymer can be adjusted appropriately by adjusting the molecular structure, crystallinity, etc. of the (C) ethylene-α-olefin copolymer through the type and proportion of structural units derived from α-olefin, polymerization conditions, etc.

[0044] More specifically, the crystalline melting peak and crystallization peak of the (C) ethylene-α-olefin copolymer can be measured, for example, by the following method. Measurement is carried out using a differential scanning calorimeter (Seiko Instruments DSC220C: power compensation DSC) under the following conditions. (i) Approximately 5 mg of sample is heated from room temperature to 200°C at a rate of 30°C / min, and after the temperature is raised, the sample is held for 5 minutes. (ii) Next, the temperature is lowered from 200°C to -100°C at a rate of 10°C / min, and after the temperature drop is complete, the sample is held at this temperature for 5 minutes. The peak observed in (ii) is a crystallization peak, and the presence or absence of a crystallization peak with a peak area of ​​1 J / g or more is confirmed. (iii) Next, the temperature is raised from -100°C to 200°C at a rate of 10°C / min. The peak observed in (iii) is taken as the melting peak of the crystal, and the presence or absence of a melting peak with a peak area of ​​1 J / g or more is confirmed, and its position and peak area are determined.

[0045] (C) Ethylene-α-olefin copolymers can be obtained by polymerization using known methods, such as a Ziegler-Natta catalyst or a metallocene catalyst, in an inert solvent such as hexane, heptane, toluene, or xylene.

[0046] resin composition The resin composition of the present invention contains 20 to 60 mass % of the above (A) hydroxyl group-containing polypropylene, 0 to 50 mass % of the above (B) polypropylene, and 30 to 80 mass % of the above (C) ethylene-α-olefin copolymer (where the total mass of the resin composition is taken as 100 mass %).

[0047] By containing 20 to 60 mass % of (A) hydroxyl group-containing polypropylene and 30 to 80 mass % of (C) ethylene-α-olefin copolymer, the resin composition of the present invention can achieve the effects of the present invention, such as the ability to form a coating film with good adhesion on a resin molded article containing polypropylene or the like, without the need for application of a primer. The content of (A) hydroxyl group-containing polypropylene is preferably from 20 to 55% by mass, more preferably from 20 to 50% by mass, and particularly preferably from 20 to 40% by mass. The content of (C) ethylene-α-olefin copolymer is preferably 35 to 75 mass%, more preferably 40 to 70 mass%, and particularly preferably 50 to 60 mass%. When the content of (C) ethylene-α-olefin copolymer is equal to or greater than the above lower limit, excellent impact resistance can be achieved when a composite molded article is formed by laminating a coating film, an adhesive layer containing the resin composition of the present invention, and a polyolefin molded article in this order. On the other hand, when the content is equal to or less than the above upper limit, good film formability can be obtained during film formation.

[0048] The resin composition of the present invention preferably contains, in addition to (A) hydroxyl group-containing polypropylene and (C) ethylene-α-olefin copolymer, 50 mass% or less of (B) polypropylene (excluding those corresponding to (A) hydroxyl group-containing polypropylene). By including 50% by mass or less of (B) polypropylene, the resin composition of this embodiment can achieve desirable effects such as improved tensile strength and elongation (here, the total mass of the resin composition is taken as 100% by mass). The content of (B) polypropylene is more preferably 0 to 40% by mass, and particularly preferably 0 to 30% by mass.

[0049] The resin composition of the present invention may be composed only of (A) hydroxyl group-containing polypropylene and (C) ethylene-α-olefin copolymer (and (B) polypropylene, if present), but may also contain components other than (A) hydroxyl group-containing polypropylene and (C) ethylene-α-olefin copolymer (and (B) polypropylene, if present).

[0050] Components other than (A) hydroxyl group-containing polypropylene and (C) ethylene-α-olefin copolymer (and (B) polypropylene, if present) can include, for example, various additives, fillers, other resin components, etc. There are no particular restrictions on the total amount of the various additives, fillers, other resin components, etc., but it is preferably 50 wt % or less based on the total mass of the resin composition.

[0051] As the additives, various known additives that can be used in polypropylene-based resin compositions, such as antioxidants, neutralizing agents, light stabilizers, ultraviolet absorbers, crystal nucleating agents, antiblocking agents, mineral oils, crosslinking agents, crosslinking aids, antistatic agents, and metal deactivators, can be blended.

[0052] Examples of antioxidants include phenol-based antioxidants, phosphite-based antioxidants, and thio-based antioxidants. Examples of neutralizing agents include higher fatty acid salts such as calcium stearate and zinc stearate. Examples of light stabilizers and ultraviolet absorbers include hindered amines, benzotriazoles, and benzophenones.

[0053] Examples of nucleating agents include aromatic carboxylic acid metal salts, aromatic phosphate metal salts, sorbitol derivatives, metal salts of rosin, and amide nucleating agents. Among these nucleating agents, aluminum p-tert-butylbenzoate, sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 2,2'-methylenebis(4,6-di-tert-butylphenyl)aluminum phosphate, a complex of aluminum hydroxide bis(2,4,8,10-tetra-tert-butyl-6-hydroxy-12H-dibenzo[d,g][1,2,3]dioxaphosphocin-6-oxide) and an organic compound, p-methylbenzylidenesorbitol, p-ethylbenzylidenesorbitol, 1,2,3-trideoxy-4,6:5,7-bis[(4-propylphenyl)methylene]nonitol, and sodium salt of rosin can be mentioned.

[0054] Examples of lubricants include higher fatty acid amides such as stearic acid amide, etc. Examples of mineral oils include high-boiling fractions of petroleum such as aromatic mineral oil, naphthenic mineral oil, and paraffinic mineral oil. Examples of crosslinking agents include organic peroxides, phenolic resins, sulfur, sulfur-containing compounds, p-quinone, p-quinonedioxime derivatives, bismaleimide compounds, epoxy compounds, silane compounds, and amino resins. Examples of crosslinking aids include polyfunctional compounds such as sulfur-based, methacrylate-based, and maleimide-based compounds. Examples of antistatic agents include fatty acid partial esters such as glycerin fatty acid monoesters, etc. Examples of metal deactivators include triazines, phosphones, epoxies, triazoles, hydrazides, and oxamides.

[0055] As the filler, various known fillers that can be used in polypropylene-based resins, such as inorganic fillers and organic fillers, can be blended. Examples of inorganic fillers include calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, magnesium silicate, glass fiber, and carbon fiber. Examples of organic fillers include crosslinked rubber fine particles, thermosetting resin fine particles, hollow thermosetting resin fine particles, and conductive carbon.

[0056] Examples of other resin components include other thermoplastic resins such as olefin resins other than propylene-based and ethylene-based resins, and aromatic vinyl resins such as styrene-based resins. It is also possible to color it to add design features, and various coloring agents such as inorganic pigments, organic pigments, dyes, etc. Luster materials such as aluminum flakes, titanium oxide flakes, and (synthetic) mica can also be used.

[0057] The method for producing the resin composition of the present invention is not particularly limited, but it can be produced by melt-kneading predetermined amounts of (A) hydroxyl group-containing polypropylene and (B) polypropylene (and (C) ethylene-α-olefin copolymer, if used), or by dry-blending a mixture of melt-kneaded portions of the above components with the other components.

[0058] Decorative film A decorative film can be formed using the resin composition of the present invention. More specifically, when constructing a decorative film in which (1) a coating film and (2) an adhesive layer are laminated in this order, the resin composition of the present invention can be used for the (2) adhesive layer, and more specifically, a resin layer containing the resin composition of the present invention can be used as the (2) adhesive layer. Since the resin composition of the present invention has excellent adhesion to polyolefins, the (2) adhesive layer containing the resin composition of the present invention can be bonded with good adhesion to various polyolefin-containing members, such as (3) polyolefin molded articles. This allows the (1) coating film to be formed with good adhesion to (3) polyolefin molded articles and the like, without the need for application of a primer. This allows for the formation of a composite molded body in which the (1) coating film, (2) adhesive layer, and (3) polyolefin molded body are laminated in this order. In this composite molded body, as described above, the (1) coating film is formed with good adhesion on the (3) polyolefin molded body without the need for a primer. Methods for joining the (2) adhesive layer to the (3) polyolefin molded body include, but are not limited to, thermocompression bonding, TOM molding, and insert molding.

[0059] 2 layer structure The resin composition of the present invention can be used to form a two-layer structure. More specifically, in constructing a two-layer structure in which (2) an adhesive layer and (3) a polyolefin molded body are laminated in this order, the resin composition of the present invention can be used for the (2) adhesive layer, and even more specifically, a resin layer containing the resin composition of the present invention can be used as the (2) adhesive layer. Methods for producing the two-layer structure include, but are not limited to, heat-pressure bonding and insert molding. The resin composition of the present invention has excellent adhesion to coating films, and therefore the (2) adhesive layer containing the resin composition of the present invention can be bonded to coating films, such as the (1) coating film, with good adhesion. This makes it possible to form the (1) coating film with good adhesion on the (3) polyolefin molded article, etc., without the need for application of a primer. As a result, (1) the coating film, (2) the adhesive layer, and (3) the polyolefin molded body are formed in this order. In this composite molding, the above-mentioned (3) Good adhesion to polyolefin molded bodies, without the need for a primer. (1) A coating film is formed.

[0060] (2) The thickness of the adhesive layer is not particularly limited, but (3) from the viewpoint of conformability to the shape of the polyolefin molded article, etc., the thickness is preferably 1 mm or less. (2) The thickness of the adhesive layer is more preferably 0.5 mm or less, and even more preferably 0.01 to 0.2 mm. (2) The content of the resin composition of the present invention in the adhesive layer is not particularly limited, but is preferably 50% by mass or more from the viewpoint of more effectively realizing the effects of the resin composition of the present invention, etc. (2) The content of the resin composition of the present invention in the adhesive layer is more preferably 80 to 100% by mass, and particularly preferably 90 to 100% by mass.

[0061] Although there are no particular limitations on the components of the (1) coating film, the embodiment in which the (1) coating film contains a water-based paint provides an even greater technical value for the effects of the present invention. More specifically, water-based paints generally do not necessarily have high adhesion to (3) polyolefin molded bodies, etc., and conventional techniques have required the application of a primer, so when the (1) coating film contains a water-based paint, the technical effect of the present invention, in which a good coating film can be formed without the use of a primer, is even more valuable. There is no particular limitation on the type of water-based paint, but preferred examples include various dyes, water-soluble resin-based paints, and water-based emulsions. The coating film may be composed of only a water-based paint, or may contain a water-based paint and other components such as a water-based solvent, a surfactant, a leveling agent, and the like.

[0062] Although there are no particular limitations on the components of the (3) polyolefin molded body, the embodiment in which the (3) polyolefin molded body contains polypropylene provides an even greater technical value for the effects of the present invention. More specifically, since it is generally difficult to form a coating film on a member containing polypropylene and prior art has required the application of a primer, the technical effect of the present invention, that is, the ability to form a good coating film without using a primer, is even more valuable when the (3) polyolefin molded body contains polypropylene. (3) When the polyolefin molded article contains polypropylene, the polypropylene is not particularly limited, and may be, for example, any of the above-mentioned (B1) propylene homopolymer, (B2) propylene random copolymer, (B3) heterophasic propylene polymer material, etc. In this embodiment, only one type of polypropylene may be used, or two or more types may be used in combination.

[0063] (3) When the polyolefin molded article contains polypropylene, the polyolefin may be the same as or different from (A) the hydroxyl group-containing polypropylene or (B) the polypropylene in the resin composition of the present invention used in (2) the adhesive layer. There is no particular limitation on the polypropylene content, but (3) polyolefin molded article can be suitably used in an amount of 40 to 80 mass % of the total mass of the polyolefin molded article, and more preferably 50 to 70 mass % of the polypropylene. (3) The polyolefin molded article may contain components other than polypropylene, and may contain additives such as polyolefins other than polypropylene, resins other than polyolefins, heat stabilizers, antistatic agents, weather stabilizers, light stabilizers, antioxidants, antioxidants, UV absorbers, softeners, dispersants, lubricants, etc., within the scope of the present invention. For example, from the viewpoint of improving impact resistance, it is preferable to compound a polyolefin other than polypropylene, such as an ethylene-α-olefin copolymer.

[0064] The decorative film of this embodiment may consist of only (1) the coating film and (2) the adhesive layer, or may have other layers. Examples of other layers include a clear layer, a surface layer, a surface decoration layer, a print layer, a light-shielding layer, a colored layer, a substrate layer, a seal layer, a barrier layer, and a tie layer. There are no particular limitations on the locations where the other layers are provided, and they may be provided on (1) the coating film, on (2) the adhesive layer, or between (1) the coating film and (2) the adhesive layer. In particular, it is preferable to provide a clear layer on the (1) coating film, that is, a decorative film in which the clear layer / (1) coating film / (2) adhesive layer are laminated in this order can be preferably used.

[0065] Composite molding and manufacturing method thereof By using the decorative film or two-layer structure of this embodiment, a composite molded article can be produced in which (1) a coating film, (2) an adhesive layer, and (3) a polyolefin molded article are laminated in this order, and in which (2) the adhesive layer contains the resin composition of the present invention. More specifically, the composite molded article can be produced using the decorative film of this embodiment by a production method including the following steps. Step i) (3) A step of arranging the polyolefin molded body and the decorative film of this embodiment so that at least a portion of the surface of the polyolefin molded body (3) comes into contact with at least a portion of the adhesive layer (2) of the decorative film. Step ii) (3) A step of heating and bonding the polyolefin molded body and the decorative film

[0066] FIG. 1 is a schematic diagram showing a method for producing a composite molded body according to the above embodiment. As shown in the upper part of FIG. 1(a), a decorative film 1 is provided in which 14 (clear layer), 11 ((1) coating film), and 12 ((2) adhesive layer) are laminated in this order. 13 ((3) polyolefin molded body) and the decorative film 1 are arranged so that one surface of the (3) polyolefin molded body faces 12 ((2) adhesive layer) of the decorative film 1 (Figure 1(a)). Next, one surface of 13 ((3) polyolefin molded body) is brought into contact with 12 ((2) adhesive layer) of the decorative film 1 (FIG. 1(b), corresponding to step i) above). Next, 13 ((3) polyolefin molded body) and the decorative film 1 are heated to heat-bond them together (15, corresponding to step ii) above), and a composite molded body is produced in which 14 (clear layer), 11 ((1) coating film), 12 ((2) adhesive layer), and 13 ((3) polyolefin molded body) are laminated in this order.

[0067] As another specific example, the composite molded article can be produced using the two-layer structure of the above embodiment by a production method including the following steps. Step i') Providing a two-layer structure according to the above embodiment Step ii') forming a coating film (1) on at least a portion of the surface of the adhesive layer (2) of the two-layer structure obtained in step i'. There are no particular limitations on the process for providing the two-layer structure in step i'), but it is preferable to bond (2) the adhesive layer onto the surface of (3) the polyolefin molded body by thermocompression bonding or insert molding.

[0068] FIG. 2 is a schematic diagram showing a method for producing a composite molded body according to the above embodiment. As shown in FIG. 2(a), a two-layer structure 2 is provided in which 12 ((2) adhesive layer) and 13 ((3) polyolefin molded body) are laminated in this order (corresponding to step i' above). Next, a liquid paint is applied from a paint sprayer 17 to the surface of the adhesive layer 12 ((2)) of the two-layer structure 2 (FIG. 2(b)). The liquid coating is then cured to form a coating film (1) on at least a portion of the surface of the adhesive layer (2) of the two-layer structure (Fig. 2(b)). 16 Coating film formation, corresponding to step ii) above. This produces a composite molded body in which 11 ((1) coating film), 12 ((2) adhesive layer), and 13 ((3) polyolefin molded body) are laminated in this order (Fig. 2(c) bottom). In a more preferred embodiment, a clear layer is further formed on 11 ((1) coating film). More specifically, following the above steps, a clear coating is applied from a clear coating spray 19 onto the surface of 11 ((1) coating film) of the composite molded body (FIG. 2(c)). The clear coating is then cured to form 14 (clear layer) on at least a portion of the surface of the (1) coating film of the composite molded body. This produces a composite molded body in which 14 (clear layer), 11 ((1) coating film), 12 ((2) adhesive layer), and 13 ((3) polyolefin molded body) are laminated in this order (FIG. 2(d)). In both the composite molded article of the embodiment in Fig. 1 and the composite molded article of the embodiment in Fig. 2, other layers, such as a surface layer, a surface decorative layer, a printed layer, a light-shielding layer, a colored layer, a substrate layer, a sealing layer, a barrier layer, and / or a tie layer, may be provided. The other layers may be provided on all or part of the surface of the composite molded article, i.e., on 14 (clear layer), 11 ((1) coating film), or 13 ((3) polyolefin molded article), or may be provided all or part of the spaces between the layers constituting the composite molded article (not shown).

[0069] The composite molded article of this embodiment allows a coating film to be formed easily and with good adhesion on a resin molded article containing polypropylene or the like at a relatively low cost, and therefore can be suitably used in various applications requiring both lightweight properties, impact resistance, etc., and appearance, design, etc. For example, it can be suitably used in various applications such as various automobile interior and exterior parts such as bumpers, fenders, back doors, side moldings, rocker moldings, various parts for home appliances, various housing equipment parts, various industrial parts, and various building material parts. [Example]

[0070] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0071] <Ingredients> The abbreviations and details of the raw materials used in the examples are shown below. [(C) Ethylene-α-olefin copolymer] Ethylene-octene copolymer (EOR-1) Density=0.870g / cm 3 The ethylene-octene random copolymer used had an MFR (190°C, 2.16 kg load) of 1.0 g / 10 min, a melting point of 60.8°C measured using a DSC (Q100, manufactured by TA Instruments), and a heat of crystalline fusion (ΔH) of 47 J / g. [(A) Hydroxyl group-modified polypropylene polymer] Hydroxyl-modified polypropylene copolymer (PPOH-1) A polypropylene homopolymer resin with an MFR of 0.5 g / 10 min at 230°C and a load of 2.16 kg was mixed with 2-hydroxyethyl methacrylate and di(tert-butylperoxypropyl)benzene and subjected to graft copolymerization modification by melt kneading using a twin-screw kneader at a cylinder temperature of 180°C. After modification, the MFR at 230°C and a load of 2.16 kg was 450 g / 10 min, and the graft modification rate was 1.3%. Hydroxyl-modified polypropylene copolymer (PPOH-2) A heterophasic propylene polymer material with an MFR of 0.6 g / 10 min at 230°C and a load of 2.16 kg, an ethylene-propylene copolymer content of 16% by mass, and a mass ratio of ethylene-derived structural units to propylene-derived structural units of 40 / 60 was mixed with 2-hydroxyethyl methacrylate and di(tert-butylperoxypropyl)benzene and subjected to graft copolymerization modification by melt kneading using a twin-screw kneader at a cylinder temperature of 180°C. After modification, the MFR at 230°C and a load of 2.16 kg was 275 g / 10 min, and the graft modification rate was 1.0%. [(B) Polypropylene] Polypropylene copolymer (PP-1) A heterophasic propylene polymer material having an MFR (230°C, 2.16 kg load) of 3.4 g / 10 min, an ethylene-propylene copolymer content of 20 mass %, and a mass ratio of ethylene-derived structural units / propylene-derived structural units in the ethylene-propylene copolymer of 37 / 63. [(3) Materials for polyolefin molded articles] A polypropylene composite material was used, which was obtained by kneading the following raw materials in a twin-screw kneader. Heterophagic propylene polymer material (MFR (230°C, 2.16 kg load) = 63 g / 10 min, ethylene-propylene copolymer content = 14.0%, mass ratio of ethylene-derived structural units / propylene-derived structural units in the ethylene-propylene copolymer = 30 / 70): 59 parts by mass Ethylene-butene copolymer (density = 0.862 g / cm 3 , MFR (190℃, 2.16kg load) = 1.2g / 10min): 10 parts by mass Ethylene-octene copolymer (density = 0.857 g / cm 3 , MFR (190℃, 2.16kg load) = 1.0g / 10min): 10 parts by mass Talc: 21 parts by weight

[0072] Example 1 <Preparation of modified polyolefin sheet> 60 parts by mass of EOR-1 and 40 parts by mass of PPOH-1 were kneaded in a bench kneader (Labo Plastomill, manufactured by Toyo Seiki Seisaku-sho) at 200°C for 6 minutes at a rotation speed of 80 rpm. The resulting modified polyolefin composition was heat-molded using a press molding machine (trade name: F37, manufactured by Shinto Metal Industries Co., Ltd.) at 200°C for 6 minutes at 9.5 MPa to obtain a pressed sheet (modified polyolefin sheet) with a thickness of 0.1 mm.

[0073] <Fabrication of a two-layer structure> The modified polyolefin sheet prepared above was cut into a size of 150 mm x 90 mm and placed on the flat surface of a mold for making a 150 mm x 90 mm x 3 mm thick plate. A polypropylene composite was injection molded using an injection molding machine (IS100EN-3A, manufactured by Toshiba Machine) at a molding temperature of 200°C, a mold cooling temperature of 50°C, an injection time of 10 seconds, and a cooling time of 30 seconds, to obtain a two-layer structure of the modified polyolefin sheet ((2) adhesive layer) and the polypropylene composite ((3) polyolefin molded body).

[0074] <Preparation of painted flat plate> On the modified polyolefin sheet side of the two-layer structure of modified polyolefin sheet and polypropylene composite material prepared above, "WBC-713T#040" (a water-based transparent colored base coat paint manufactured by Kansai Paint Co., Ltd.) was applied with an air gun to a dry film thickness of 15 μm, and the plate was preheated in an oven at 80°C for 5 minutes. Then, "Soflex 7172" (an acrylic urethane two-component solvent-based clear paint manufactured by Kansai Paint Co., Ltd.) was applied as a clear paint with an air gun to a dry film thickness of 30 μm, and the plate was baked at 120°C for 30 minutes to obtain a coated plate.

[0075] Example 2 40 parts by mass of EOR-1 and 20 parts by mass of PP-1 were mixed in a tabletop mixer (Labo Plastomill, manufactured by Toyo Seiki Seisaku-sho) at 200°C for 2 minutes at a rotation speed of 80 rpm, and then 40 parts of PPOH-1 was added and mixed again at 200°C for 4 minutes at a rotation speed of 80 rpm. Thereafter, a coated plate was obtained in the same manner as in Example 1.

[0076] Example 3 40 parts by mass of EOR-1 and 60 parts by mass of PPOH-2 were kneaded in a bench kneader (Labo Plastomill, manufactured by Toyo Seiki Seisaku-sho) at 200°C for 2 minutes at a rotation speed of 80 rpm. The resulting modified polyolefin composition was heat-molded using a press molding machine (trade name: F37, manufactured by Shinto Metal Industries Co., Ltd.) at 200°C for 6 minutes at 9.5 MPa to obtain a 0.5 mm thick press sheet (modified polyolefin sheet). Thereafter, a coated flat plate was obtained in the same manner as in Example 1.

[0077] (Comparative Example 1) Using a press molding machine (product name: F37, manufactured by Shinto Metal Industries Co., Ltd.), 100 parts by mass of PPOH-2 was hot-molded at 200°C for 6 minutes under 9.5 MPa to obtain a pressed sheet (modified polyolefin sheet) with a thickness of 0.1 mm. Thereafter, a coated plate was obtained in the same manner as in Example 1.

[0078] (Comparative Example 2) A 150mm x 90mm x 3mm thick plate of the above polypropylene composite was prepared, and "WBC-713T#040" (a water-based transparent colored base coat paint manufactured by Kansai Paint Co., Ltd.) was applied to one side of the plate with an air gun to a dry film thickness of 15μm, and the plate was preheated in an oven at 80°C for 5 minutes. Next, "Soflex 7172" (a 2-component acrylic urethane solvent-based clear paint manufactured by Kansai Paint Co., Ltd.) was applied as a clear paint with an air gun to a dry film thickness of 30μm, and the plate was baked at 120°C for 30 minutes to obtain a coated plate.

[0079] <Evaluation> The coated flat plates produced in the above Examples and Comparative Examples were evaluated according to the following procedures. [Measurement of coating adhesion] Test pieces were prepared by cutting grid lines into the coated flat plate with a cutter blade in accordance with JIS K5400. Cellotape (registered trademark) manufactured by Nichiban Co., Ltd. was attached to the test piece and then quickly pulled off. The number of grid lines where the coating remained was counted and used as an index of adhesion according to the following classification. The results are shown in Table 1. ○: 90 or more squares remaining out of 100 squares ×: 89 or fewer squares remaining out of 100 squares

[0080] [Evaluation of impact strength of painted flat plates] The coated plates were cut into 75mm x 90mm pieces and tested for high-speed impact strength using a Hydroshot high-speed puncture impact tester (HITS-P10, manufactured by Shimadzu Corporation) under the following conditions. The total energy to fracture (TE) was calculated from the results and is shown in Table 1. Holder diameter: 1.5 inches ·Speed: 2.8m / sec ·Temperature: -30℃

[0081] [Table 1] [Industrial Applicability]

[0082] The resin composition, composite molded body, decorative film, and method for producing a composite molded body of the present invention and its embodiments can form a coating film with good adhesion on a resin molded body containing polypropylene or the like without the need for application of a primer, and can provide a means for imparting excellent impact resistance to the composite molded body.Therefore, the resin composition, composite molded body, decorative film, and method for producing a composite molded body of the present invention can be suitably used for a variety of applications, including various automobile interior and exterior parts such as bumpers, fenders, and back doors, as well as various parts for home appliances, various housing equipment parts, various industrial parts, and various building material parts, and has high applicability in various industrial fields such as the transportation machinery industry, the electrical and electronics industry, and the building and construction industry. [Explanation of symbols]

[0083] 1:Decorative film 2: 2 layer structure 11:(1) Coating 12:(2) Adhesive layer 13: (3) Polyolefin molded body 14: Clear layer 15: Heating, joining 16: Paint film formation 17: Paint spray 18: Clear layer formation 19: Clear paint spray

Claims

1. (A) 20 to 60% by mass of hydroxyl group-containing polypropylene, (B) 0 to 50 mass% of polypropylene (excluding those corresponding to (A) hydroxyl group-containing polypropylene), and (C) A resin composition containing 30 to 80% by mass of an ethylene-α-olefin copolymer (where the total mass of the resin composition is taken as 100% by mass).

2. 2. The resin composition according to claim 1, wherein the hydroxyl group-containing polypropylene (A) is a 2-hydroxyethyl methacrylate-modified polypropylene.

3. The resin composition according to claim 1 or 2, comprising (B) polypropylene, wherein (B) polypropylene is (B3) a heterophasic propylene polymerization material.

4. The composition according to claim 1 or 2, wherein the ethylene-α-olefin copolymer (C) has a crystalline melting peak having a heat of crystalline melting exceeding 1.0 J / g in a temperature range of −100° C. to 200° C. in a curve obtained by differential scanning calorimetry.

5. The composition according to claim 1 or 2, wherein the ethylene-α-olefin copolymer (C) has a crystalline melting peak having a heat of crystalline fusion of 10.0 J / g or more in a temperature range of −100° C. to 200° C. on a curve obtained by differential scanning calorimetry.

6. A resin layer having a thickness of 1 mm or less, comprising the composition according to claim 1 or 2.

7. A composite molded body comprising (1) a coating film, (2) an adhesive layer, and (3) a polyolefin molded body laminated in this order, wherein (2) the adhesive layer is constituted by the resin layer described in claim 6.

8. (1) The composite molding according to claim 7, wherein the coating film contains a water-based paint.

9. (3) The composite molding according to claim 7, wherein the polyolefin molding contains polypropylene.

10. The composite molded article according to claim 7, which is an automobile part.

11. A decorative film comprising (1) a coating film and (2) an adhesive layer laminated in this order, wherein (2) the adhesive layer is constituted by the resin layer according to claim 6.

12. i) a step of arranging a (3) polyolefin molded body and the decorative film according to claim 11 so that at least a part of the surface of the (3) polyolefin molded body comes into contact with at least a part of the (2) adhesive layer of the decorative film; and ii) (3) A step of heating and bonding the polyolefin molded body and the decorative film; A method for producing a composite molded body having the above-mentioned features.

13. A two-layer structure comprising (2) an adhesive layer and (3) a polyolefin molded body laminated in this order, wherein (2) the adhesive layer is constituted by the resin layer according to claim 6.

14. i') providing a two-layer structure according to claim 13; and ii') forming a coating film (1) on at least a portion of the surface of the adhesive layer (2) of the two-layer structure obtained in step i'; A method for producing a composite molded body having the above-mentioned features.

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