Laminate for automobile interior material

Abstract

To provide a laminate for an automobile interior material which has excellent recyclability, in which increase of a CO2 discharge amount in recycling is suppressed, and which is light-weight and easily processed and has excellent designability.SOLUTION: A laminate for an automobile interior material comprises a polyolefin-containing skin material and a polyolefin-containing base material and has a maximum value of a melting point measured by DSC of 200°C or lower, in which the base material is preferably made of a nonwoven fabric, and the skin material contains (A) 10-90 pts.mass of an ethylene-α-olefin-nonconjugated polyene copolymer, (B) 10-90 pts.mass of a crystalline olefin-based polymer, and (D) 1-60 pts.mass of a softening agent and is preferably formed of them (provided that the sum total of (A), (B) and the softening agent (D) is set to be 100 pts.mass).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminate for automobile interior materials that is highly recyclable. [Background technology]

[0002] Automotive interior materials such as instrument panels, ceilings, door parts, and seats are widely used because they are made from thermoplastic resins, which are lightweight, easy to process, and have excellent design properties. Known examples of synthetic leather for automotive interiors include synthetic leather (Patent Document 1) made by laminating a polyurethane resin layer onto the surface of a fibrous substrate made of a tricot knit fabric, a blend of polyester, polyurethane, and other materials, and synthetic leather (Patent Document 2) made by laminating a synthetic resin, such as a polyurethane resin or a polyamide resin, onto a substrate layer made of a polyolefin such as polypropylene. However, there is a growing demand for recycling these synthetic leathers. However, some thermoplastic resins have high melting temperatures, making it difficult to maintain their resin performance due to thermal decomposition and other factors. Furthermore, the need for processing at relatively high temperatures has led to the undesirable issue of increased CO2 emissions. Furthermore, when the surface layer and substrate layer are made of different types of materials, there is the issue of having to separate the surface layer and substrate layer in order to recycle and reuse them as raw materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-111989 [Patent Document 2] WO2012 / 077180 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a laminate for automobile interior materials that has excellent recyclability, suppresses an increase in CO2 emissions during recycling, is lightweight, is easy to process, and has excellent design properties. [Means for solving the problem]

[0005] The present invention includes any one of the following aspects [1] to [7]. [1] A laminate for automotive interior materials, comprising a skin material containing a polyolefin and a substrate material containing a polyolefin, and having a maximum melting point measured by DSC of 200°C or less. [2] The laminate for automobile interior materials according to [1] above, wherein the substrate is made of a nonwoven fabric. [3] The laminate for automobile interior materials according to [1] or [2] above, wherein the skin material comprises 10 to 90 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (A), 10 to 90 parts by mass of a crystalline olefin polymer (B), and 1 to 60 parts by mass of a softener (D) (wherein the total of the above (A), (B), and softener (D) is 100 parts by mass). [4] The laminate for automobile interior materials according to any one of the above [1] to [3], wherein the thickness of the substrate is 0.6 mm or more. [5] The laminate for automobile interior materials according to any one of the above [1] to [4], which has a thickness of 1.1 mm or more. [6] The laminate for automobile interior materials according to any one of the above [1] to [5], wherein the skin material and the substrate contain polypropylene. [7] The laminate for automobile interior materials according to any one of the above [1] to [6], wherein the substrate is polypropylene. [Effects of the Invention]

[0006] According to the present invention, there is provided a laminate for automobile interior materials which has excellent recyclability, suppresses an increase in CO2 emissions during recycling, is lightweight, is easy to process, and has excellent design properties. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, a laminate for automobile interior materials will be described, which comprises a surface material containing the polyolefin of the present invention and a substrate containing the polyolefin, and has a maximum melting point of 200° C. or less as measured by DSC.

[0008] <Skin material> The skin material contains a polyolefin. In the present invention, the polyolefin is preferably an olefin-based resin, which is typically a high-molecular-weight solid product obtained by polymerizing one or more monoolefins by a high-pressure or low-pressure method. Examples of such resins include isotactic and syndiotactic monoolefin polymer resins. Representative resins are commercially available.

[0009] Suitable olefin-based raw material olefins include preferably α-olefins having 2 to 20 carbon atoms, specifically ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 5-methyl-1-hexene. These olefins may be used alone or in combination of two or more. The polymerization mode may be random or block, as long as a resinous product is obtained. These olefin-based resins may be used alone or in combination of two or more.

[0010] Examples of olefin-based resins include polyethylenes and propylene-based polymers whose main component is an olefin such as ethylene or propylene, specifically propylene homopolymers such as polypropylene, propylene-ethylene block copolymers, propylene-ethylene random copolymers, propylene-ethylene-butene random copolymers, and olefin-based thermoplastic elastomers (TPOs) including ethylene-α-olefin copolymers. Among these, propylene-based resins such as polypropylene and TPOs are preferred from the viewpoints of moldability, heat resistance, cold resistance, light weight, etc.

[0011] The olefin resin used in the present invention may contain structural units derived from at least one type of biomass-derived monomer. The same type of monomers constituting the polymer of the olefin resin may be composed solely of biomass-derived monomers, solely of fossil fuel-derived monomers, or both of biomass-derived monomers and fossil fuel-derived monomers. When the olefin resin used in the present invention is a propylene resin (propylene content is 70 mol % or more), it is preferable that the MFR (ASTM D1238-65T, 230°C, 2.16 kg) is generally in the range of 0.01 to 100 g / 10 min, particularly 0.05 to 50 g / 10 min.

[0012] The mass proportion of the olefin resin in the entire resin components of the skin material is preferably 90 mass % or more, more preferably 95 mass % or more, and even more preferably 100 mass %.

[0013] The skin material may contain a colorant, which may be selected from pigments and dyes, with pigments being preferred from the viewpoint of durability.

[0014] The thickness of the skin material in the laminate is preferably 0.3 mm to 2.0 mm, more preferably 0.4 mm to 1.0 mm, from the viewpoints of tensile strength, moldability and tactile feel.

[0015] <Thermoplastic elastomer composition (Y)> The skin material of the present invention is preferably an olefin-based thermoplastic elastomer, and among these, a thermoplastic elastomer composition (Y) having the following composition is preferred.

[0016] Ethylene-α-olefin-non-conjugated polyene copolymer (A) 10 to 90 parts by mass Crystalline olefin polymer (B) 10 to 90 parts by mass Softener (D) 1 to 60 parts by mass (The total of (A), (B) and softener (D) is 100 parts by mass.)

[0017] The thermoplastic elastomer composition (Y) is preferably a composition obtained by dynamically crosslinking a mixture containing an ethylene-α-olefin-non-conjugated polyene copolymer (A), a crystalline olefin polymer (B), and a softener (D). The dynamic crosslinking is preferably carried out in the presence of a crosslinking agent and a crosslinking aid. Each component will be explained below.

[0018] (Ethylene-α-olefin-non-conjugated polyene copolymer (A)) The ethylene-α-olefin-non-conjugated polyene copolymer (A) (hereinafter also referred to simply as "copolymer (A)") usually has (m) units derived from ethylene and (n) units derived from an α-olefin in a molar ratio range of 50 / 50 to 95 / 5, preferably 60 / 40 to 80 / 20, and more preferably 65 / 35 to 75 / 25 ((m) / (n)).

[0019] The α-olefin constituting the copolymer (A) is usually an α-olefin having 3 to 20 carbon atoms, specifically propylene, 1-butene, 4-methyl-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-nonadecene, 1-eicosene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc. Among them, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene are preferred, and propylene is particularly preferred. These α-olefins may be used alone or in combination of two or more.

[0020] Specific examples of the non-conjugated polyenes constituting the copolymer (A) include linear non-conjugated dienes such as 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 7-methyl-1,6-octadiene, 8-methyl-4-ethylidene-1,7-nonadiene, and 4-ethylidene-1,7-undecadiene; Cyclic non-conjugated dienes such as methyltetrahydroindene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 5-vinyl-2-norbornene, 5-isopropenyl-2-norbornene, 5-isobutenyl-2-norbornene, cyclopentadiene, and norbornadiene; trienes such as 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, and 4-ethylidene-8-methyl-1,7-nanodiene; and the like. These non-conjugated dienes can be used alone or in combination of two or more. Among these non-conjugated dienes, 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene (VNB) are preferred.

[0021] The copolymer (A) usually has an iodine value, which is an index of the amount of non-conjugated polyene components, in the range of 1 to 50, preferably 5 to 40, and more preferably 10 to 30. The total amount of non-conjugated dienes is usually in the range of 2 to 20 mass% of the ethylene-α-olefin-non-conjugated polyene copolymer (A) component.

[0022] The copolymer (A) usually has an intrinsic viscosity [η] measured at 135° C. in decalin solvent in the range of 1 to 10 dl / g, preferably 1.5 to 8 dl / g. The copolymer (A) may be a so-called oil-extended rubber, which is prepared by blending a softener, preferably a mineral oil-based softener, during its production. Examples of the mineral oil-based softener include conventionally known mineral oil-based softeners such as paraffin-based process oil.

[0023] Mooney viscosity [ML 1+4 (100°C)] is usually in the range of 10 to 250, preferably 30 to 150. The copolymer (A) may be used alone or in combination of two or more ethylene-α-olefin-non-conjugated polyene copolymers. The copolymer (A) can be produced by a conventionally known method.

[0024] (Crystalline Olefin Polymer (B)) The crystalline olefin polymer (B) is a homopolymer of an α-olefin such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, or 1-decene, or a copolymer of two or more α-olefins, usually containing 90 mol% or more of the main α-olefin, and has a melting point (Tm) in the range of 70 to 200°C, preferably 80 to 170°C.

[0025] The crystalline olefin polymer (B) usually has substantially no unsaturated bonds in the main chain. The crystalline olefin polymer (B) may be used alone or in combination of two or more kinds. Among these crystalline olefin polymers (B), propylene polymers (B-(a)) and ethylene polymers (B-(b)) are preferred.

[0026] Propylene polymer (B-(a)) The propylene polymer (B-(a)) is a propylene homopolymer, a random copolymer of propylene and an α-olefin having 2 to 10 carbon atoms, typically not more than 10 mol%, such as ethylene, 1-butene, 1-pentene, or 4-methyl-1-pentene, or a block copolymer of a propylene homopolymer and an amorphous or low-crystalline propylene-ethylene random copolymer, and typically has a melting point in the range of 120 to 170°C, preferably 145 to 165°C.

[0027] The propylene polymer (B-(a)) preferably has an isotactic structure as a three-dimensional structure, but it may also have a syndiotactic structure, a mixture of these structures, or a partial atactic structure.

[0028] The propylene polymer (B-(a)) usually has a melt flow rate (MFR: measured according to JIS K6758 at a temperature of 230°C and a load of 21.18N) in the range of 0.05 to 100g / 10min, preferably 0.1 to 50g / 10min.

[0029] The propylene polymer (B-(a)) is polymerized by various known polymerization methods. The propylene polymer (B-(a)) is usually produced and sold as a polypropylene resin.

[0030] Ethylene polymer (B-(b)) The ethylene polymer (B-(b)) is a homopolymer of ethylene or a random copolymer of ethylene and 10 mol% or less of an α-olefin having 2 to 10 carbon atoms, such as propylene, ethylene, 1-butene, 1-pentene, or 4-methyl-1-pentene, and typically has a melting point in the range of 80 to 150°C, preferably 90 to 130°C.

[0031] Ethylene polymers (B-(b)) are usually manufactured and sold as high-pressure low-density polyethylene, linear low-density polyethylene, high-density polyethylene, etc. The ethylene polymer (B-(b)) usually has a melt flow rate (MFR: measured according to JIS K6758 at a temperature of 190°C and a load of 21.18N) in the range of 0.05 to 100g / 10min, preferably 0.1 to 50g / 10min.

[0032] (Softener (D)) Specific examples of the softener (D) include petroleum-based softeners such as process oil, lubricating oil, paraffin, liquid paraffin, polyethylene wax, polypropylene wax, petroleum asphalt, and Vaseline; coal tar-based softeners such as coal tar and coal tar pitch; fatty oil-based softeners such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; tall oil; sab (factice); waxes such as beeswax, carnauba wax, and lanolin; ricinoleic acid, palmitic acid, stearic acid, barium stearate, and calcium stearate. Examples of suitable softeners include fatty acids and fatty acid salts such as zinc laurate, naphthenic acid, pine oil, rosin or derivatives thereof, synthetic polymeric substances such as terpene resins, petroleum resins, coumarone-indene resins, and atactic polypropylene, ester-based softeners such as dioctyl phthalate, dioctyl adipate, and dioctyl sebacate, microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, liquid polyisoprene, terminal-modified polyisoprene, hydrogenated terminal-modified polyisoprene, liquid thiokol, and hydrocarbon-based synthetic lubricating oils. Of these, petroleum-based softeners, particularly process oils, are preferably used.

[0033] The softener (D) is blended within the above blending ratio range, and within this range, it is usually blended in an amount of 10 to 200 parts by mass, preferably 15 to 150 parts by mass, and more preferably 20 to 80 parts by mass per 100 parts by mass of the copolymer (A). When the softener (D) is used in the above proportion, the resulting thermoplastic elastomer composition (Y) has excellent fluidity during molding, and the mechanical properties of the resulting molded article are not impaired. In the present invention, if the amount of the softener used exceeds 200 parts by mass, the heat resistance and heat aging resistance of the resulting thermoplastic elastomer composition (Y) tend to decrease. The softener (D) is added by a method of injecting the copolymer (A) and the crystalline olefin polymer (B) in advance, or when the copolymer (A) and the crystalline olefin polymer (B) are mixed, or by injecting the mixture (precursor) during dynamic crosslinking. In this case, the softener may be added by one of the above methods or by a combination of the above methods.

[0034] (Crosslinking agent) Examples of crosslinking agents used in dynamically crosslinking a mixture containing an ethylene-α-olefin-non-conjugated polyene copolymer (A) and a crystalline olefin polymer (B) include organic peroxides, sulfur, sulfur compounds, and phenolic vulcanizing agents such as phenolic resins, among which organic peroxides are preferably used.

[0035] Specific examples of organic peroxides include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl perbenzoate, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide.

[0036] Among these, in terms of odor and scorch stability, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, and n-butyl-4,4-bis(tert-butylperoxy)valerate are preferred, and of these, 1,3-bis(tert-butylperoxyisopropyl)benzene is most preferred.

[0037] These organic peroxides are usually used in an amount of 0.01 to 3 parts by mass, preferably 0.03 to 1 part by mass, per 100 parts by mass of the total amount of the copolymer (A) and the crystalline olefin polymer (B). When the organic peroxide is used in the above amount, a thermoplastic elastomer composition (Y) in which at least a portion of the copolymer (A) is crosslinked can be obtained, and a molded product having sufficient heat resistance, tensile properties, and rubber elasticity can be obtained.

[0038] (Crosslinking aid) In the crosslinking treatment with the organic peroxide, a crosslinking aid such as sulfur, p-quinone dioxime, p,p'-dibenzoylquinone dioxime, N-methyl-N,4-dinitrosoaniline, nitrobenzene, diphenyl guanidine, or trimethylolpropane-N,N'-m-phenylenedimaleimide, or a crosslinking aid consisting of a polyfunctional methacrylate monomer such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, or allyl methacrylate, or a polyfunctional vinyl monomer such as vinyl butyrate or vinyl stearate, may be added. By adding such a crosslinking aid, a uniform and gentle crosslinking reaction of the copolymer (A) can be expected. In particular, the use of divinylbenzene in the present invention is most preferable because it is easy to handle, has good compatibility between the copolymer (A) that is the main component of the treated material and the crystalline olefin polymer (B), and has a solubilizing effect on the organic peroxide and acts as a dispersing aid for the organic peroxide, thereby achieving a uniform crosslinking effect by heat treatment and providing a thermoplastic elastomer composition (Y) that has a good balance between fluidity and physical properties.

[0039] The crosslinking aid is usually used in an amount of 0.01 to 3 parts by mass, preferably 0.03 to 1 part by mass, per 100 parts by mass of the total amount of the copolymer (A) and the crystalline olefin polymer (B).

[0040] (Other additives) The thermoplastic elastomer composition (Y) or the mixture of the composition before dynamic crosslinking may contain additives such as slip agents, nucleating agents, fillers, antioxidants, weather stabilizers, colorants, and foaming agents, as needed, within the range that does not impair the object of the present invention.

[0041] The nucleating agents include non-melting and melting crystallization nucleating agents, which can be used alone or in combination. Non-melting crystallization nucleating agents include inorganic substances such as talc, mica, silica, and aluminum, brominated biphenyl ether, aluminum hydroxydi-p-tert-butylbenzoate (TBBA), organic phosphates, rosin-based crystallization nucleating agents, substituted triethylene glycol terephthalate, and terylene & nylon fibers. Aluminum hydroxydi-p-tert-butylbenzoate, sodium methylenebis(2,4-di-tert-butylphenyl)phosphate, sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, and rosin-based crystallization nucleating agents are particularly desirable. Melting crystallization nucleating agents include sorbitol-based compounds such as dibenzylidene sorbitol (DBS), substituted DBS, and lower alkyl dibenzylidene sorbitol (PDTS).

[0042] Examples of the slip agent include fatty acid amides, silicone oils, glycerin, waxes, and paraffin oils. Examples of the filler include conventionally known fillers, specifically carbon black, clay, talc, calcium carbonate, kaolin, diatomaceous earth, silica, alumina, graphite, and glass fiber.

[0043] (Method for producing thermoplastic elastomer composition (Y)) The thermoplastic elastomer composition (Y) is obtained by dynamically crosslinking a mixture containing the copolymer (A), the crystalline olefin polymer (B), and the softener (D) in the above-mentioned blending ratio range. When performing dynamic crosslinking, it is preferable to dynamically heat-treat the mixture in the presence of the crosslinking agent or in the presence of the crosslinking agent and the crosslinking coagent.

[0044] Here, "dynamic heat treatment" means kneading in a molten state. The dynamic heat treatment in the present invention is preferably carried out in a non-open type apparatus, and is preferably carried out in an inert gas atmosphere such as nitrogen or carbon dioxide gas. The heat treatment temperature is in the range of from the melting point of the crystalline olefin polymer (B) to 300°C, usually 150 to 270°C, preferably 170 to 250°C. The kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes. The applied shear force is a shear rate of 10 to 50,000 sec -1 , preferably 100 to 10,000 seconds -1 The range is.

[0045] As the kneading device, a mixing roll, an intensive mixer (for example, a Banbury mixer or a kneader), a single-screw or twin-screw extruder, etc. can be used, but a non-open type device is preferred. According to the present invention, the above-mentioned dynamic heat treatment provides a thermoplastic elastomer composition (Y) in which the copolymer (A) is at least partially crosslinked.

[0046] (Other thermoplastic resins) Furthermore, other thermoplastic resins include vinyl chloride resins; vinylidene chloride resins; acrylic resins; ethylene-vinyl acetate copolymers; ethylene-methacrylic acid acrylate copolymers; ionomers; and ethylene-vinyl alcohol copolymers.

[0047] (Other ingredients) The polymer composition forming the skin material may consist of the copolymer (A), the polymer (B), and the softener (D), but may also contain, in addition to the copolymer (A), the polymer (B), and the softener (D), other suitable additives as other components, as necessary.

[0048] Examples of additives that can be used, provided they do not impair the object of the present invention, include weather resistance stabilizers, heat resistance stabilizers, antistatic agents, antislip agents, antiblocking agents, foaming agents, foaming aids, antifogging agents, lubricants, pigments, dyes, plasticizers, antioxidants, hydrochloric acid absorbers, antioxidants, crystal nucleating agents, antifungal agents, antibacterial agents, flame retardants, fillers (inorganic fillers, organic fillers), and softeners. The total amount of these additives used is 0.001 to 30 parts by mass, with the total of the copolymer (A) and the polymer (B) being 100 parts by mass.

[0049] <Base material> The substrate contains a polyolefin. In the present invention, the polyolefin is preferably an olefin-based resin, and is usually a high-molecular-weight solid product obtained by polymerizing one or more monoolefins by a high-pressure or low-pressure method. The olefin resin is the same as that described above in the "skin material," but for the substrate, a propylene polymer, specifically a propylene homopolymer, a propylene-ethylene block copolymer, a propylene-ethylene random copolymer, or a propylene-ethylene-butene random copolymer, is preferred as the olefin resin.

[0050] When the olefin resin used in the present invention is a propylene resin such as polypropylene (the proportion of propylene units in the polymer is 70 mol % or more), the MFR (ASTM D1238-65T, 230°C, 2.16 kg) is preferably in the range of usually 0.01 to 100 g / 10 min, particularly 0.05 to 50 g / 10 min.

[0051] The proportion of the olefin resin in the entire resin components of the substrate is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass.

[0052] The thickness of the substrate in the laminate is preferably 0.3 mm or more, more preferably 0.6 mm or more, from the viewpoints of tensile strength, moldability, and tactile feel, and is preferably 5.0 mm or less. The substrate may also contain various stabilizers, ultraviolet absorbers, plasticizers, lubricants, or colorants.

[0053] The substrate is preferably a nonwoven fabric. The nonwoven fabric is made of polyolefin fibers, and the basis weight of the nonwoven fabric is preferably 50 g / m 2 More preferably, 100 g / m2 More than 500g / m 2 The following is the result.

[0054] Suitable nonwoven fabrics include those made by depositing or entangling short fibers made of polyolefin resin, and those made by melt-blown or spunbonding methods, etc. Among these, nonwoven fabrics made of fibers made of propylene-based resin are particularly suitable. When needle punching is used to manufacture nonwoven fabrics, the number of punchings and needle strokes can be adjusted to control the degree of fiber entanglement, thereby imparting appropriate rigidity and abrasion resistance.

[0055] Nonwoven fabrics may also be made by mixing fibers with binder resins, low-melting fibers, etc. to achieve the appropriate entanglement strength. Examples of binder resins include acrylonitrile-butadiene latex, styrene-butadiene latex, acrylate latex, and vinyl acetate latex.

[0056] <Forming of laminate> In a method for forming the laminate of the present invention, the skin material is formed by melt-extrusion laminating, for example, a polyolefin resin, preferably the above-mentioned dynamically crosslinked thermoplastic elastomer composition (Y), onto a continuously supplied substrate, to form a skin material having a thickness of usually about 0.3 mm to 2.0 mm, to form a laminate.

[0057] The present invention also includes the case where the skin material is a foam skin material. The foamed skin material can be produced by melt foam molding from a foaming composition containing the above-mentioned copolymer (A), crystalline olefin polymer (B), and softener (D), and also typically 1 to 15 parts by mass of a foaming agent. Another example is a laminate produced by extrusion laminating a skin material consisting of a foaming composition that forms a layer made of a resin foam and a composition that forms a layer made of a polyolefin resin, preferably a thermoplastic elastomer (Y), onto a substrate by co-extrusion molding.

[0058] The blowing agent used in the present invention includes inorganic or organic thermal decomposition type blowing agents (chemical blowing agents), carbon dioxide, nitrogen, and mixtures of carbon dioxide and nitrogen.

[0059] Examples of inorganic thermal decomposition type foaming agents include inorganic carbonates such as sodium hydrogen carbonate, sodium carbonate, ammonium hydrogen carbonate and ammonium carbonate, and nitrites such as ammonium nitrite.

[0060] Examples of organic thermally decomposable blowing agents include nitroso compounds such as N,N'-dimethyl-N,N'-dinitrosoterephthalamide and N,N'-dinitrosopentamethylenetetramine; azo compounds such as azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene and barium azodicarboxylate; sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, p,p'-oxybis(benzenesulfonyl hydrazide) and diphenylsulfone-3,3'-disulfonyl hydrazide; azide compounds such as calcium azide, 4,4'-diphenyldisulfonyl azide and p-toluenesulfonyl azide; and thermally expandable microcapsules (for example, trade name: ADVANCELL EM manufactured by Sekisui Chemical Co., Ltd.).

[0061] When carbon dioxide or nitrogen is used, the foaming composition is melted at 100 to 300°C in a resin plasticizing cylinder to form a molten foamable thermoplastic elastomer composition in which the foaming composition and the carbon dioxide or nitrogen are in a compatible state.

[0062] Examples of foaming aids include metal compounds such as zinc, calcium, lead, iron, and barium, higher fatty acids such as stearic acid and their metal salts, and fine inorganic particles such as talc, barium sulfate, and silica.Specific examples include mixtures of polycarboxylic acids such as citric acid, oxalic acid, fumaric acid, phthalic acid, malic acid, tartaric acid, cyclohexane-1,2-dicarboxylic acid, camphoric acid, ethylenediaminetetraacetic acid, triethylenetetraminehexaacetic acid, and nitrilotriacetic acid with inorganic carbonate compounds such as sodium hydrogencarbonate, sodium aluminum hydrogencarbonate, and potassium hydrogencarbonate, as well as intermediates produced by the reaction of these, such as salts of polycarboxylic acids such as sodium dihydrogen citrate and potassium oxalate.

[0063] These foaming agents or foaming aids may be dry-blended before extrusion molding so that they are decomposed during extrusion molding, or may be melt-blended into pellets in advance and then added.

[0064] <Laminate for automotive interior materials> The laminate of the present invention has a maximum melting point, as measured by DSC, of ​​200°C or less, preferably 190°C or less, more preferably 180°C or less, and preferably 140°C or more. This makes it highly recyclable, suppresses the increase in CO2 emissions during recycling, is lightweight, can be easily processed into various designs, maintains its strength despite temperature changes inside the automobile, and is heat resistant, making it suitable as a laminate for automobile interior materials. From the viewpoint of further improving flexibility, the laminate of the present invention has a thickness of 0.1 mm or more, more preferably 0.5 mm or more, of which 0.9 mm or more, and even more preferably 1.1 mm or more. Furthermore, the thickness is 10 mm or less, more preferably 5.0 mm or less, and even more preferably 3.5 mm or less. By setting the thickness within this range, the laminate does not take up too much space in the vehicle. The laminate of the present invention can exhibit the properties of light weight and moldability, and is used for automotive interior materials such as instrument panels, ceilings, door parts, and seats.

[0065] Example Examples are shown below, but the present invention is not limited to these examples. The following materials were prepared as substrates. Foam 1: Polypropylene foam sheet (Toray Industries, Inc., 25020-AP17, density 39 kg / m 3 ) Nonwoven fabric 1: PP spunbond nonwoven fabric (Mitsui Chemicals, Inc., Syntex PS-120, material PP, Weight 100g / m 2 ) Nonwoven fabric 2: PP spunbond nonwoven fabric (Mitsui Chemicals, Toughnel PA-4021, material PP, Weight 100g / m 2 ) Nonwoven fabric 3: PP spunbond nonwoven fabric (Mitsui Chemicals, Toughnel TST-545, material PP, Weight 140g / m 2 ) Nonwoven fabric 4: PP continuous long fiber nonwoven fabric (Mitsui Chemicals Industrial Products Co., Ltd., Polyfelt EX EX-26, material PP, Weight 140g / m 2 ) Nonwoven fabric 5: PP continuous long fiber nonwoven fabric (Mitsui Chemicals Industrial Products Co., Ltd., Polyfelt EX EX-60, material PP, Weight 300g / m 2 ) Nonwoven fabric 6: PP continuous long fiber nonwoven fabric (Mitsui Chemicals Industrial Products Co., Ltd., Polyfelt EX EX-80, material PP, Weight 400g / m 2 ) Nonwoven fabric 7: Spunbond nonwoven fabric (MA Life Materials Co., Ltd., Toughnel ESE-545, Material: PET / PP composite, basis weight: 140g / m 2 ) PET is polyethylene terephthalate, PP is polypropylene, and PE is polyethylene, and these are composite materials made from these components.

[0066] The physical properties of the raw materials of the substrates and skin materials used in the examples and comparative examples were measured by the following methods. Measurement of substrate relationships Melting point (Tm) and heat of fusion (ΔH) The melting points of Foam 1 and Nonwoven Fabrics 1 to 7 were determined by differential scanning calorimetry (DSC) using the following method. 10 mg of the sample was placed in a dedicated aluminum pan, and the sample was heated from room temperature to 300°C at a rate of 10°C / min under a nitrogen atmosphere using an X-DSC7000 (manufactured by SII Corporation). The melting point (Tm) and heat of fusion (ΔH) of the polymer were determined from the peak of the endothermic curve during the first heating. The heat of fusion (ΔH) is calculated by determining the area enclosed by the line connecting the low-temperature point where there is no change in heat quantity and the high-temperature point where there is no change in heat quantity as a baseline and the line portion including the peak of the endothermic curve obtained by the above measurement and the above baseline. When multiple peaks were detected in the endothermic curve, the temperature and peak area of ​​the highest peak were taken as the melting point (Tm) and heat of fusion (ΔH), respectively. The results are shown in Table 1.

[0067] Measurement of the relationship between skin materials Mass fraction of constituent units The mass fraction (mass%) of each structural unit contained in the ethylene-α-olefin-non-conjugated polyene copolymer (A-1) is 13 Specifically, the C-NMR of copolymer (A-1) was measured using an ECX400P nuclear magnetic resonance spectrometer (manufactured by JEOL Ltd.) under the conditions of a measurement temperature of 120°C, a measurement solvent of orthodichlorobenzene / deuterated benzene = 4 / 1 (volume ratio), and an accumulation number of 8000. 13 Calculated from the C-NMR spectrum.

[0068] Evaluation method for thermoplastic elastomer compositions for skin materials <Press sheet production> Pellets of the thermoplastic elastomer compositions obtained in the Examples and Comparative Examples were pressed using a hot press molding machine (pressing temperature: 190°C, cooling temperature: 20°C, preheating time: 6 minutes, pressure melting time: 4 minutes). As a result of the pressing, two types of flat pressed sheets with different thicknesses were produced for each composition. The obtained pressed sheets were 12 cm long x 14.7 cm wide x 2 mm thick, and 12 cm long x 14.7 cm wide x 0.5 mm thick, respectively.

[0069] Shore A hardness (instantaneous value) Three of the 2 mm thick press sheets were stacked together to form a test sample, and the Shore A hardness (instantaneous value) was determined using a durometer in accordance with the method described in JIS K 6253. The results are shown in Table 2.

[0070] Modulus, Tensile Stress at Break, Tensile Elongation at Break The above-mentioned pressed sheet was punched to a thickness of 2 mm to prepare a dumbbell-shaped No. 3 test piece. Using the prepared test piece, a tensile test (tensile speed: 500 mm / min, measurement temperature: 23°C) was carried out in accordance with JIS K 6251 to measure the modulus at 100% elongation (M100), stress at break (TB), and elongation at break (EB). The results are shown in Table 2.

[0071] Melting point (Tm) and heat of fusion (ΔH) The melting point of the skin material was determined by differential scanning calorimetry (DSC) using the following method. 10 mg of the sample was placed in a dedicated aluminum pan, and the sample was heated from room temperature to 300°C at a rate of 10°C / min under a nitrogen atmosphere using an X-DSC7000 (manufactured by SII Corporation). The melting point (Tm) and heat of fusion (ΔH) of the polymer were determined from the peak of the endothermic curve during the first heating. The heat of fusion (ΔH) is calculated by determining the area enclosed by the line connecting the low-temperature point where there is no change in heat quantity and the high-temperature point where there is no change in heat quantity as a baseline and the line portion including the peak of the endothermic curve obtained by the above measurement and the above baseline. When multiple peaks were detected in the endothermic curve, the temperature and peak area of ​​the highest peak were taken as the melting point (Tm) and heat of fusion (ΔH), respectively. The results are shown in Table 2.

[0072] The skin material was formed using the following materials: Raw materials for skin (1) Ethylene-α-olefin-non-conjugated polyene copolymer (A) Ethylene-α-olefin-non-conjugated polyene copolymer (A-1) Oil-extended ethylene-propylene-non-conjugated diene copolymer rubber was used. (EPDM, product name: 3072EPM; manufactured by Mitsui Chemicals, Inc.) Ethylene content = 64 mass%, propylene content = 30.6 mass%, Non-conjugated diene species: 5-ethylidene-2-norbornene, Non-conjugated diene content = 5.4% by mass Mooney viscosity [ML (1+4) 125℃]=51 Oil-extended amount (parts by mass): Ethylene-α-olefin-non-conjugated polyene copolymer Amount of oil extension (parts by mass) per 100 parts by mass = 40 (PHR) The values ​​for copolymer (A-1) in Table 2 indicate the blending ratio of only the rubber component, excluding the amount of oil extension. Furthermore, a paraffin-based process oil ("PW-100" manufactured by Idemitsu Kosan Co., Ltd.) was used to extend copolymer (A-1). This is the same as (D-1) below.

[0073] (2) Crystalline olefin polymer (B) Crystalline propylene polymer (B-1) Propylene-ethylene block copolymer (Product name: EL-Pro P740J; manufactured by SCG Chemicals, MFR (according to ASTM D 1238-65T; 230℃, 2.16kg load) = 27g / 10min) Melting point = 163°C, ΔH = 93 J / g)

[0074] (3) Soft propylene copolymer (C) Propylene-ethylene copolymer (C-1) (Product name:VERSIFY TM 2400.05, Manufactured by The Dow Chemical Company Melt flow rate (230℃, 2.16kg load) 2g / 10min Density 863kg / m 3 )

[0075] (4) Softener (D) Softener (D-1) Paraffin-based process oil (Product name: Diana Process Oil PW-100, manufactured by Idemitsu Kosan Co., Ltd.) The numerical values ​​of the blending ratio of the softener (D-1) in Table 2 include the blending amount of the softener (D-1) used for oil-extending the copolymer (A-1).

[0076] Crosslinking agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, (Product name: Perhexyne 25B, manufactured by Nippon Oil & Fats Co., Ltd.) Crosslinking aid Divinylbenzene, (Product name: DVB-810, manufactured by Nippon Steel Chemical & Material Co., Ltd.)

[0077] The breakdown of the crosslinking agent mixture of 0.84 parts by mass is as follows: Crosslinking agent 0.28 parts by weight Crosslinking aid 0.28 parts by mass, Softener (D-1) 0.28 parts by mass A mixture of equal amounts of each was used as shown below. The softener used when mixing this crosslinking agent mixture was the same as the softener (D-1) described above.

[0078] Manufacturing Example 1 Preparation of thermoplastic elastomer composition pellets for skin material 1 Ethylene-α-olefin-non-conjugated polyene copolymer (A) 40 parts by mass (oil-extended ethylene-propylene-non-conjugated diene copolymer rubber) (EPDM product name: 3072EPM; manufactured by Mitsui Chemicals, Inc.) 40 parts by mass, And the amount of oil extension agent (D-1) is 16 parts by mass, making it 56 parts by mass. Furthermore, 40 parts by mass of crystalline propylene polymer (B-1), 0.84 parts by mass of the above crosslinking agent mixture The above was thoroughly mixed in a Henschel mixer to obtain a mixture. (The amount of softener (D-1) in the mixture is 16.28 parts by mass.)

[0079] Next, this mixture was extruded using an extruder (model name: HYPERKTX-46, manufactured by Kobe Steel, Ltd.) Cylinder temperatures: C1 = 110°C, C2 = 120°C, C3 = 140°C, C4 = 140°C, C5=150℃, C6=160℃, C7~C8=180℃, C9~C14=230℃, Die temperature: 200℃ The mixture was melted at 40°C, and granulation was carried out while additional softener (D-1) was poured into the cylinder, to obtain pellets of the thermoplastic elastomer composition for skin material 1.

[0080] The proportion of the softener (D-1) added was determined so that the softener (D-1) in the pellets would have the blend ratio shown in Table 2 for skin material 1. That is, since 16 parts by mass of the softener (D-1) is already contained as the oil extender, the additional softener (D-1) is added in a ratio of 4 parts by mass.

[0081] Manufacturing Example 2 Preparation of thermoplastic elastomer composition pellets for skin material 2 Pellets of the thermoplastic elastomer composition for the skin material 2 were obtained in the same manner as in Example 1, except that the blending ratios of the raw materials used were changed to those shown in Table 2, that a soft propylene copolymer (C-1) was used, and that the blending ratio of the crosslinking agent mixture was changed to the blending ratio shown in Table 2.

[0082] Manufacturing Example 3 Preparation of thermoplastic elastomer composition pellets for skin material 3 Pellets of the thermoplastic elastomer composition for the skin material 3 were obtained in the same manner as in Example 1, except that the blending ratios of the raw materials used were changed as shown in Table 2, and that a soft propylene copolymer (C-1) was used and the blending ratio of the crosslinking agent mixture was changed to the blending ratio shown in Table 2.

[0083] Example Laminate manufacturing Using the above-mentioned foam 1 or any one of nonwoven fabrics 1 to 7 as the substrate, and any one of the pellets of the thermoplastic elastomer composition for skin material 1 to skin material 3 as the skin material, laminates of the examples and comparative examples shown in Table 3 were molded. That is, using the above-mentioned thermoplastic elastomer composition pellets, T-die molding machine (Toshiba Machine Co., Ltd.) Cylinder temperature: C1=160, C2=170, C3=180, C4=190, C5~C6=200℃, D1~D5=200℃, Squeezing roll temperature: 60~90℃ Take-up speed: 2.1m / min Rotation speed: 50-55 rpm A sheet of skin material having a thickness of 0.5 mm was extruded by the extrusion roller, and after the sheet extrusion had stabilized, the base material sheet was inserted just before the squeeze roll, and laminate molding was performed by thermocompression bonding of the rolls, resulting in a laminate consisting of the skin material and the base material.

[0084] Laminate evaluation Thickness measurement method The laminate was cut, and the cut surface was observed under a microscope (Olympus SZX-16) to measure the thickness of each layer. The sum of the thicknesses of the individual layers is the overall thickness of the laminate.

[0085] Compression Workload Using a YAWASA measuring instrument Type MSES-0512-1-SL manufactured by Tech Gihan Co., Ltd., measurements were taken at the center of the sheet under the conditions of an indenter diameter of 20.0 mm, a pressing speed of 1.0 mm / s, and a maximum load of 3.0 N, to determine the compression work. A larger value of the compression work load means a softer feel when pressed, and therefore a more luxurious feel.

[0086] flexibility The flexibility was evaluated according to the following criteria. ○: Compression work is 5.0 gf cm / cm 2 exceeded ×: Compression work is 5.0 gf cm / cm 2 was below

[0087] Melting Performance The melting point observed by DSC was measured and evaluated for meltability according to the following evaluation criteria. When multiple melting points were observed, the maximum melting point was used in the evaluation criteria below. ○: Melting point was 200°C or less △: The melting point was above 200°C and below 230°C ×: Melting point was over 230°C

[0088] [Table 1]

[0089] [Table 2]

[0090] [Table 3]

Claims

1. A laminate for automobile interior materials, comprising a skin material containing a polyolefin and a substrate material containing a polyolefin, the maximum melting point measured by DSC being 200°C or less.

2. 2. The laminate for automobile interior materials according to claim 1, wherein the substrate comprises a nonwoven fabric.

3. 2. The laminate for automobile interior materials according to claim 1, wherein the skin material comprises 10 to 90 parts by mass of an ethylene-α-olefin-non-conjugated polyene copolymer (A), 10 to 90 parts by mass of a crystalline olefin-based polymer (B), and 1 to 60 parts by mass of a softener (D) (wherein the total of (A), (B), and softener (D) is 100 parts by mass).

4. 2. The laminate for automobile interior materials according to claim 1, wherein the thickness of the substrate is 0.6 mm or more.

5. 2. The laminate for automobile interior materials according to claim 1, wherein the laminate for automobile interior materials has a thickness of 1.1 mm or more.

6. 2. The laminate for automobile interior materials according to claim 1, wherein said skin material and said substrate comprise polypropylene.

7. 2. The laminate for automobile interior materials according to claim 1, wherein the substrate is polypropylene.

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