Laminate, method for manufacturing a laminate, and automotive interior surface

Abstract

To provide a laminate having a multilayer structure consisting of a top coat layer, an adhesion layer, a thermoplastic elastomer layer and a foamed layer, with excellent adhesion to the adhesion layer, and a method for producing the laminate, and an automobile interior skin including the laminate.SOLUTION: A laminate includes a top coat layer, an adhesion layer, a thermoplastic elastomer layer composed of a thermoplastic elastomer composition including the following component (A) and component (B), and a foamed layer. An automobile interior skin includes the laminate. The component (A): an olefinic thermoplastic elastomer and the component (B): a modified polyalkylene ether glycol modified with an acid and / or a derivative thereof.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminate, a method for manufacturing the laminate, and an automotive interior skin made of this laminate.

Background Art

[0002] The laminate of industrial parts typified by an instrument panel or a door trim of an automobile has a multi-layer laminate structure including a layer made of a thermoplastic elastomer. Such a laminate has been put into practical use, for example, with a layer structure such as a top coat layer / adhesive layer / thermoplastic elastomer layer / foam layer in order from the surface layer. In such a laminate, efforts have been made to improve the adhesiveness between the adhesive layer and the thermoplastic elastomer layer.

[0003] For example, when providing a top coat layer via an adhesive layer on one side of a thermoplastic elastomer layer, in order to enhance the adhesiveness between the thermoplastic elastomer layer and the adhesive layer, a device for performing surface treatment on the surface of the thermoplastic elastomer by corona treatment or the like is known.

[0004] Also, a technique for enhancing the adhesiveness with an adhesive layer by introducing a functional group into a thermoplastic elastomer is known. Specifically, maleic anhydride-modified polyolefin obtained by modifying an olefin-based resin with maleic anhydride (see Patent Document 1), and a modified polyester-based elastomer obtained by copolymerizing polytetramethylene ether glycol with a polyester-based resin and then modifying it with maleic anhydride are known (see Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] In recent years, there has been a growing demand for improved adhesion between the adhesive layer and the thermoplastic elastomer layer in laminates, not only from the perspective of reducing costs through process elimination but also from the perspective of reducing CO2 emissions, without requiring surface treatments such as corona treatment. However, thermoplastic elastomers using modified polyolefins or modified polyester elastomers described in Patent Documents 1 and 2 had room for improvement in terms of adhesion to the adhesive layer.

[0007] This invention has been made in view of the above-mentioned conventional problems, and aims to provide a laminate having a laminated structure of a topcoat layer / adhesive layer / thermoplastic elastomer layer / foam layer, which exhibits excellent adhesion to the adhesive layer, and a method for manufacturing the laminate. The present invention also aims to provide an automotive interior surface using this laminate. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, the present inventors have found that a laminate having a top coat layer, an adhesive layer, a thermoplastic elastomer layer made of a specific thermoplastic elastomer composition, and a foam layer can solve the above problems.

[0009] In other words, the gist of this invention is as follows:

[0010] [1] A laminate having a top coat layer, an adhesive layer, a thermoplastic elastomer layer made of a thermoplastic elastomer composition containing the following components (A) and (B), and a foam layer. Component (A): Olefin-based thermoplastic elastomer Component (B): Modified polyalkylene ether glycol modified with an acid and / or its derivatives

[0011] [2] The laminate according to [1], wherein the thermoplastic elastomer composition further comprises the following component (E). Ingredient (E): Styrene-based thermoplastic elastomer

[0012] [3] The laminate according to [1] or [2], further comprising a decorative layer between the thermoplastic elastomer layer and the foam layer.

[0013] [4] An automotive interior surface made of a laminate as described in any of [1] to [3].

[0014] [5] A method for producing a laminate, comprising the steps of: forming a thermoplastic elastomer layer made of a thermoplastic elastomer composition containing the following components (A) and (B); forming an adhesive layer containing an adhesive on at least one surface of the thermoplastic elastomer layer; and forming a top coat layer. Component (A): Olefin-based thermoplastic elastomer Component (B): Modified polyalkylene ether glycol modified with an acid and / or its derivatives

[0015] [6] The method for producing a laminate according to [5], wherein the thermoplastic elastomer composition further comprises the following component (E). Ingredient (E): Styrene-based thermoplastic elastomer

[0016] [7] A method for producing a laminate, comprising the steps of: forming a thermoplastic elastomer layer made of a thermoplastic elastomer composition obtained by melt-kneading a mixture containing the following components (A), (b), (c), and (d); forming an adhesive layer containing an adhesive on at least one surface of the thermoplastic elastomer layer; and forming a top coat layer. Component (A): Olefin-based thermoplastic elastomer Ingredient (b): Polyalkylene ether glycol Component (c): Acids and / or derivatives thereof Component (d): Peroxide

[0017] [8] The method for producing a laminate according to [7], wherein the thermoplastic elastomer composition further contains the following component (E). Component (E): Styrenic thermoplastic elastomer

[0018] [9] A thermoplastic elastomer composition for bonding an adhesive layer, comprising the following component (A) and component (B). Component (A): Olefinic thermoplastic elastomer Component (B): Modified polyalkylene ether glycol modified with an acid and / or its derivative [Advantages of the Invention]

[0019] According to the present invention, in a laminate having a laminated structure of a top coat layer / adhesive layer / thermoplastic elastomer layer / foam layer, it is possible to provide a laminate excellent in adhesiveness to the adhesive layer and a method for producing the laminate. According to the present invention, it is also possible to provide an automotive interior skin using this laminate.

[0020] Further, according to the method for producing a laminate of the present invention, it is possible to provide a laminate excellent in interlayer adhesiveness without corona treatment. [Brief Description of the Drawings]

[0021] [Figure 1] It is a schematic cross-sectional view of an automotive instrument panel according to an embodiment of the laminate of the present invention. [Embodiments for Carrying Out the Invention]

[0022] Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to the following contents as long as it does not exceed the gist thereof. When the expression "~" is used in this specification, it is used in the sense of including the numerical values or physical property values described before and after it. Also, the numerical values or physical property values described as upper and lower limits are used in the sense of including those values.

[0023] [Thermoplastic elastomer composition] The thermoplastic elastomer composition constituting the thermoplastic elastomer layer of the laminate of the present invention (hereinafter sometimes referred to as "the thermoplastic elastomer composition of the present invention") will be described below.

[0024] The thermoplastic elastomer composition of the present invention comprises the following components (A) and (B). Component (A): Olefin-based thermoplastic elastomer Component (B): Modified polyalkylene ether glycol modified with an acid and / or its derivatives The thermoplastic elastomer composition of the present invention is preferably a thermoplastic elastomer composition obtained by reacting the following components (a) to (c) in the presence of component (d). Component (a): Olefin-based thermoplastic elastomer Ingredient (b): Polyalkylene ether glycol Component (c): Acids and / or derivatives thereof Component (d): Peroxide Note that component (A) and component (a) are synonymous. In the following, component (a) may be explained as component (A), but the explanation will be applied by replacing "component (A)" with "component (a)". Similarly, the explanation of "component (a)" can be applied by replacing it with "component (A)".

[0025] [Component (A): Olefin-based thermoplastic elastomer] As component (A), known olefin-based thermoplastic elastomers can be used. For example, polypropylene polymers, polyethylene polymers, etc., can be used, or they can be made by containing one or more types of ethylene-propylene copolymer rubber (EPM), ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), ethylene-butene copolymer rubber (EBM), ethylene-propylene-butene copolymer rubber, etc.

[0026] From the viewpoint of moldability, the olefin-based thermoplastic elastomer of component (A) typically has a melt flow rate (MFR) of 0.1 to 50 g / 10 min at a temperature of 230°C and a measuring load of 49 N in accordance with ISO 1133 (2011), preferably 0.5 to 40 g / 10 min, and more preferably 1 to 35 g / 10 min.

[0027] For the olefin-based thermoplastic elastomer of component (A), the durohardness A (value after 15 seconds), measured in accordance with ISO 7619, is preferably 95 or less, more preferably in the range of 20 to 90, and even more preferably in the range of 50 to 80. If the durohardness A is above the lower limit, it is preferable because it has good flexibility. If the durohardness A is below the upper limit, it is preferable because it has good moldability and processability.

[0028] A commercially available example of component (A) is "Torexplane®" manufactured by Mitsubishi Chemical Corporation.

[0029] These olefin-based thermoplastic elastomers may be used individually or in mixtures of two or more types.

[0030] [Component (B)] Component (B) is a modified polyalkylene ether glycol modified with an acid and / or its derivative.

[0031] Modified polyalkylene ether glycols are obtained by graft-modifying polyalkylene ether glycol (component (b)) with an acid and / or its derivative (component (c)), as is known in Macromol. Chem. Phys. 197, 981-990 (1996). The higher the graft-modification rate with the acid and / or its derivative in the modified polyalkylene ether glycol, the better the adhesion tends to be.

[0032] <Component (b): Polyalkylene ether glycol> Polyalkylene ether glycols are typically polyhydroxy compounds that have one or more ether bonds in the main backbone of their molecule.

[0033] Examples of repeating units in the main skeleton of polyalkylene ether glycols include saturated hydrocarbon groups having 1 to 20 carbon atoms, such as 1,2-ethylene glycol units, 1,2-propylene glycol units, 1,3-propanediol (trimethylene glycol) units, 2-methyl-1,3-propanediol units, 2,2-dimethyl-1,3-propanediol units, 1,4-butanediol (tetramethylene glycol) units, 2-methyl-1,4-butanediol units, 3-methyl-1,4-butanediol units, 3-methyl-1,5-pentanediol units, neopentyl glycol units, 1,6-hexanediol units, 1,7-heptanediol units, 1,8-octanediol units, 1,9-nonanediol units, 1,10-decanediol units, and 1,4-cyclohexanedimethanol units. A homopolymerized polyalkylene ether glycol may be formed using only one of these repeating units, or a copolymerized polyalkylene ether glycol may be formed using two or more repeating units.

[0034] In the present invention, the polyalkylene ether glycol used is preferably one of the polyalkylene ether glycols having the repeating units in the main skeleton, from the viewpoint of the mechanical strength and adhesive strength of the resulting thermoplastic elastomer composition, specifically polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol (PTMG), copolymer polytetramethylene ether glycol of 3-methyltetrahydrofuran and tetrahydrofuran, copolymer polyether polyol of neopentyl glycol and tetrahydrofuran, copolymer polyether polyol of ethylene oxide and tetrahydrofuran, or copolymer polyether glycol of propylene oxide and tetrahydrofuran. Among these, polytetramethylene ether glycol (PTMG) is more preferred.

[0035] In the present invention, the molecular weight of the polyalkylene ether glycol is not particularly limited, but a number-average molecular weight (Mn) of 200 to 4500, and particularly 200 to 3000, is preferred for application in various uses.

[0036] The number-average molecular weight (Mn) of polyalkylene ether glycol can be analyzed by gel permeation chromatography (GPC). In this invention, the POLYTETRAHYDROFURAN calibration kit from POLYMERLABORATORIES, UK was used for GPC calibration. The number-average molecular weight (Mn) of polytetramethylene ether glycol used in the examples and comparative examples described below was also measured using this method.

[0037] Polyalkylene ether glycols are available commercially. For example, the PTMG series and BioPTMG series manufactured by Mitsubishi Chemical Corporation can be used.

[0038] Polyalkylene ether glycol may be used alone, or two or more types with different compositions and physical properties may be used in combination.

[0039] <Component (c): Acids and / or derivatives thereof> The acid and / or derivative thereof used for modification is not particularly limited, but unsaturated carboxylic acids are preferably used. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, hymic acid, and citraconic acid. Examples of derivatives of unsaturated carboxylic acids include their acid anhydrides, esters, amides, imides, and metal salts.

[0040] Examples of derivatives of unsaturated carboxylic acids include, specifically, maleic anhydride, hymic anhydride, itaconic anhydride, citraconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, glycidyl acrylate, monoethyl maleate, diethyl maleate, monomethyl itaconicate, diethyl itaconicate, acrylamide, methacrylamide, monoamide maleate, diamide maleate, N-monoethyl maleate, N-N-diethyl maleate, N-N-monobutylamide maleate, N-N-dibutylamide maleate, monoamide fumarate, diamide fumarate, N-N-monobutylamide fumarate, N-N-dibutylamide fumarate, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, and potassium methacrylate.

[0041] These acids and / or their derivatives may be used individually or in combination of two or more.

[0042] Of these, maleic acid and / or its anhydride are preferred because they have a low electron density and high reactivity.

[0043] The amount of acid and / or its derivative used is usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, per 100 parts by mass of the olefin-based thermoplastic elastomer of component (a) (component (A)), while usually 5 parts by mass or less, preferably 4 parts by mass or less. If the amount of acid and / or its derivative used is above the lower limit, the adhesion between the thermoplastic elastomer layer made of the thermoplastic elastomer composition described later and the adhesive layer made of the adhesive tends to be good. On the other hand, if it is below the upper limit, the generation of unreacted substances and by-products is suppressed, which tends to prevent deterioration of the product appearance due to fish eyes, blemishes, etc. in the resulting laminate, and also suppresses a decrease in adhesion.

[0044] <Component (d): Peroxide> The peroxide is used as a radical initiator in the graft modification of the modified polyalkylene ether glycol of component (B).

[0045] In the present invention, both aromatic organic peroxides and aliphatic organic peroxides can be used as the peroxide. Specifically, dialkyl peroxides such as di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexine-3, 1,3-bis(t-butylperoxyisopropyl)benzene, 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane; t-butyl peroxybenzoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2 Examples include peroxyesters such as ,5-di(benzoylperoxy)hexane and 2,5-dimethyl-2,5-di(benzoylperoxy)hexine-3; hydroperoxides such as acetylperoxide, lauroylperoxide, benzoylperoxide, p-chlorobenzoylperoxide, and 2,4-dichlorobenzoylperoxide; diacylperoxides such as di-3,5,5-trimethylhexanoylperoxide, octanoylperoxide, and dibenzoylperoxide; and ketoneperoxides such as methyl ethyl ketoneperoxide and cyclohexanoneperoxide.

[0046] The peroxides listed above may be used individually or in combination of two or more.

[0047] Among these, those with a half-life temperature of 100°C or higher are preferred from the viewpoint of graft modification efficiency. Specifically, dialkyl peroxides such as di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyn-3 are preferred, as are peroxyesters such as t-butyl peroxybenzoate, t-butyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, and 2,5-dimethyl-2,5-di(benzoylperoxy)hexyn-3.

[0048] The amount of peroxide used is usually 3 parts by mass or more, preferably 5 parts by mass or more, per 100 parts by mass of polyalkylene ether glycol of component (b), while usually 20 parts by mass or less, preferably 15 parts by mass or less. By using an amount of peroxide above the lower limit, graft modification can be carried out efficiently, and by using an amount below the upper limit, the generation of odor due to the reaction residue of the peroxide can be reduced.

[0049] <Graft Degeneration> To produce the modified polyalkylene ether glycol of component (B), the polyalkylene ether glycol is modified using the aforementioned component (b): polyalkylene ether glycol, component (c): acid and / or its derivative, and component (d): peroxide in predetermined proportions. The modification of the polyalkylene ether glycol can be carried out, for example, by melting the polyalkylene ether glycol and adding the acid and / or its derivative and peroxide to perform graft modification. Alternatively, the polyalkylene ether glycol can be dissolved in a solvent and added the acid and / or its derivative and peroxide to perform graft modification. Among the above manufacturing methods, the method of modification by melting is preferred in terms of equipment, time, and environment.

[0050] In methods that involve melting and denaturing the material, a kneader is typically used. Suitable kneaders include Banbury mixers (intensive mixers), pressurized kneaders, and twin-screw extruders.

[0051] The Banbury mixer has two rotors in the mixing chamber, which rotate in opposite directions to knead the ingredients. It is also configured to apply pressure to the ingredients using a pressure ram and to heat or cool the ingredients from the outside via a jacket.

[0052] A pressurized kneader has two blades positioned in the mixing chamber, which rotate in opposite directions to knead the compounding material. It is also configured to apply pressure to the compounding material via a pressurized cylinder and to heat or cool the compounding material from the outside via a jacket.

[0053] A twin-screw extruder has two screws arranged inside a cylinder, and these screws rotate in the same direction or in different directions to transport the compound material back and forth, applying pressure and shear force to knead it. The outer wall of the cylinder is surrounded by a heater and a cooling jacket, allowing the compound material to be heated or cooled from the outside.

[0054] Modification using a kneader is typically carried out at a temperature of around 160-350°C, according to the settings of the kneader used. As described later, the modification of the polyalkylene ether glycol can be carried out in the presence of the olefin-based thermoplastic elastomer of component (a).

[0055] <Component (E): Styrene-based thermoplastic elastomer> From the viewpoint of enhancing adhesion, the thermoplastic elastomer composition of the present invention preferably contains a styrene-based thermoplastic elastomer. The styrene-based thermoplastic elastomer can be any of the following: styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), or their hydrogenated forms, styrene-ethylene-butylene-styrene copolymer (SEBS) or styrene-ethylene-ethylene-styrene copolymer (SEEPS). In this invention, one or more of these styrene-based elastomers can be used.

[0056] The number-average molecular weight of the styrene-based thermoplastic elastomer of component (E) is not limited, but is preferably 20,000 or more, more preferably 40,000 or more, as measured by gel permeation chromatography (hereinafter sometimes abbreviated as GPC) in terms of polystyrene equivalent. It is also preferably 500,000 or less, and more preferably 400,000 or less. When the number-average molecular weight is within the above range, flexibility and moldability tend to be good.

[0057] The styrene unit content of component (E) styrene-based thermoplastic elastomer is not limited, but is preferably 5% by mass or more, and more preferably 10% by mass or more. On the other hand, it is preferably 50% by mass or less, and more preferably 45% by mass or less.

[0058] Component (E), styrene-based thermoplastic elastomer, is available commercially. For example, you can select and use a suitable product from Kraton's "Kraton G Polymer" or Kuraray Co., Ltd.'s "Septon®" series.

[0059] [Content percentage] From the viewpoint of adhesion, the thermoplastic elastomer composition of the present invention preferably contains 0.1 to 30 parts by mass of component (B) per 100 parts by mass of component (A). From the viewpoint of stable adhesion, the lower limit of the content of component (B) is more preferably 0.2 parts by mass or more, and even more preferably 0.5 parts by mass or more. On the other hand, from the viewpoint of handling during manufacturing, the upper limit of the content of component (B) is more preferably 25 parts by mass or less, and even more preferably 15 parts by mass or less.

[0060] When the thermoplastic elastomer composition of the present invention contains component (E), the content of component (E) is preferably 1 to 10 parts by mass per 100 parts by mass of component (A) from the viewpoint of adhesion. The lower limit of the content of component (E) is more preferably 0.1 parts by mass or more, and even more preferably 1 part by mass or more, from the viewpoint of stable adhesion. On the other hand, the upper limit of the content of component (E) is more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, from the viewpoint of appearance.

[0061] [Other ingredients] In addition to the above-mentioned components (A), (component (a)), (component (B)), and (E), other components may be added to the thermoplastic elastomer composition of the present invention, depending on the purpose, as long as they do not impair the effects of the present invention.

[0062] Other components include, for example, various additives such as fillers, antioxidants, heat stabilizers, light stabilizers, UV absorbers, neutralizing agents, lubricants, antifogging agents, antiblocking agents, slip agents, dispersants, colorants, flame retardants, antistatic agents, conductivity imparters, metal deactivators, molecular weight modifiers, antibacterial agents, antifungal agents, fluorescent whitening agents, and hydrocarbon rubber softeners. Any of these can be used individually or in combination.

[0063] The thermoplastic elastomer composition of the present invention preferably contains a hydrocarbon-based rubber softener in order to soften the resulting thermoplastic elastomer composition, increase its flexibility and elasticity, and improve the processability and fluidity of the resulting thermoplastic elastomer composition.

[0064] Examples of hydrocarbon-based rubber softeners include mineral oil-based softeners and synthetic resin-based softeners. Mineral oil-based softeners are particularly preferred. Mineral oil-based softeners are generally mixtures of aromatic hydrocarbons, naphthenic hydrocarbons, and paraffinic hydrocarbons. Those in which 50% or more of the total carbon atoms are paraffinic hydrocarbons are called paraffinic oils, those in which 30-45% of the total carbon atoms are naphthenic hydrocarbons are called naphthenic oils, and those in which 35% or more of the total carbon atoms are aromatic hydrocarbons are called aromatic oils. Among these, paraffinic oils are preferred.

[0065] The kinematic viscosity of the hydrocarbon-based rubber softener at 40°C is preferably 20 centistokes (cSt) or higher, more preferably 50 cSt or higher, while it is preferably 800 cSt or lower, and more preferably 600 cSt or lower. Furthermore, the flash point (COC method) of the hydrocarbon-based rubber softener is preferably 200°C or higher, and more preferably 250°C or higher.

[0066] Commercially available hydrocarbon rubber softeners may be used. For example, the "Nisseki Polybutene® HV" series from JX Nippon Oil & Energy Corporation and the "Diana® Process Oil PW" series from Idemitsu Kosan Co., Ltd. can be selected and used as appropriate.

[0067] Hydrocarbon-based rubber softeners can be used individually or in any combination and ratio of two or more types.

[0068] Examples of fillers include glass fibers, hollow glass spheres, carbon fibers, alumina, talc, calcium carbonate, mica, potassium titanate fibers, silica, metal soap, calcium carbonate, titanium dioxide, carbon black, and boron nitride. These fillers may be used individually, or two or more may be used in any combination and ratio.

[0069] As heat stabilizers, the following can be used: aliphatic, aromatic or alkyl-substituted aromatic esters of phosphoric acid and phosphorous acid, hypophosphite derivatives, phosphorus compounds such as phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates, dialkylpentaerythritol diphosphite, and dialkylbisphenol A diphosphite; phenol derivatives, especially hindered phenol compounds; sulfur-containing compounds such as thioethers, dithioates, mercaptobenzimidazoles, thiocarbanilides, and thiodipropionates; and tin compounds such as sutmarate and dibutyltin monoxide.

[0070] Examples of hindered phenol compounds include "Irganox 1010" and "Irganox 1520" (both trade names, manufactured by BASF Japan Ltd.). Examples of phosphorus compounds include "PEP-36," "PEP-24G," and "HP-10" (all brand names: manufactured by ADEKA Corporation), and "Irgafos168" (brand name: manufactured by BASF Japan Ltd.).

[0071] Examples of sulfur-containing compounds include thioether compounds such as dilauryl thiopropionate (DLTP) and distearyl thiopropionate (DSTP).

[0072] The content of these heat stabilizers, as a mass percentage in 100 parts by mass of the thermoplastic elastomer composition, has a lower limit of preferably 0.01% by mass, more preferably 0.05% by mass, and an upper limit of preferably 1% by mass, more preferably 0.5% by mass. By setting the mass percentage of the heat stabilizer above the lower limit, its additive effect can be fully obtained, and by setting it below the upper limit, its precipitation can be suppressed.

[0073] Examples of light stabilizers include benzotriazole and benzophenone compounds. Specifically, "TINUVIN622LD" and "TINUVIN765" (both brand names: manufactured by BASF Japan Ltd.), and "SANOLLS-2626" and "SANOLLS-765" (both brand names: manufactured by Sankyo Co., Ltd.) can be used.

[0074] Examples of UV absorbers include "TINUVIN328" and "TINUVIN234" (both brand names, manufactured by BASF Japan Ltd.).

[0075] The content of these light stabilizers and ultraviolet absorbers, expressed as a mass percentage in 100 parts by mass of the thermoplastic elastomer composition, has a lower limit of preferably 0.01% by mass, more preferably 0.05% by mass, and an upper limit of preferably 1% by mass, more preferably 0.5% by mass. By setting the content of the light stabilizers and ultraviolet absorbers above the lower limit, their additive effect can be fully obtained, and by setting it below the upper limit, their precipitation can be suppressed.

[0076] Examples of colorants include dyes such as direct dyes, acid dyes, basic dyes, and metal complex dyes; inorganic pigments such as carbon black, titanium dioxide, zinc oxide, iron oxide, and mica; and organic pigments such as coupling azos, condensation azos, anthraquinones, thioindigos, dioxazones, and phthalocyanines.

[0077] Examples of flame retardants include additives and reactive flame retardants such as phosphorus and halogen-containing organic compounds, bromine or chlorine-containing organic compounds, ammonium polyphosphate, aluminum hydroxide, and antimony oxide.

[0078] These additives may be used individually or in any combination and ratio of two or more types.

[0079] [Method for producing thermoplastic elastomer compositions] The thermoplastic elastomer composition of the present invention is obtained by melt-kneading an olefin-based thermoplastic elastomer (component (A)) and a modified polyalkylene ether glycol (component (B)) using the above-described kneader or the like. This method includes a one-stage method in which the olefin-based thermoplastic elastomer (component (a)) is added simultaneously when producing the modified polyalkylene ether glycol to obtain the thermoplastic elastomer composition of the present invention, and a two-stage method in which the modified polyalkylene ether glycol is produced first, and then the olefin-based thermoplastic elastomer (component (A)) is mixed in afterward to obtain the thermoplastic elastomer composition of the present invention. Alternatively, the thermoplastic elastomer composition of the present invention containing a large amount of modified polyalkylene ether glycol can be produced using the one-stage method, and this can be used as a masterbatch to be mixed with the olefin-based thermoplastic elastomer (component (A)) in the second stage (masterbatch method). In the case of the one-stage method and the masterbatch method, it is preferable to use the aforementioned kneader, and more preferable to use a twin-screw kneader.

[0080] The thermoplastic elastomer composition of the present invention can also be obtained by reacting a mixture containing component (a): olefin-based thermoplastic elastomer, component (b): polyalkylene ether glycol, component (c): acid and / or its derivative, and component (d): peroxide. The mixture preferably contains 0.1 to 30 parts by mass of component (b), 0.01 to 5 parts by mass of component (c), and 0.01 to 3 parts by mass of component (d) per 100 parts by mass of component (a). If the mixture further contains a styrene-based thermoplastic elastomer as component (E), it is preferable that the mixture contains 0.1 to 30 parts by mass of component (b), 0.01 to 5 parts by mass of component (c), 0.01 to 3 parts by mass of component (d), and 1 to 10 parts by mass of component (E) per 100 parts by mass of component (a).

[0081] [Molding] The thermoplastic elastomer composition of the present invention can be formed into a thermoplastic elastomer layer of the laminate of the present invention by various commonly used molding methods, such as injection molding, extrusion molding, calendering, hollow molding, compression molding, and vacuum molding. Among these, extrusion molding and calendering are preferred. Furthermore, secondary processing such as lamination molding and thermoforming can be performed after these molding processes.

[0082] [Laminate] The laminate of the present invention comprises at least a top coat layer, an adhesive layer, a thermoplastic elastomer layer made of a thermoplastic elastomer composition containing the above-mentioned components (A) and (B), and a foam layer.

[0083] [Top coat layer] Thermoplastic resin elastomer layers have inferior adhesion, scratch resistance, abrasion resistance, and chemical resistance on their surface compared to other surface materials such as polyvinyl chloride resin; therefore, coating is necessary to improve these properties. For this reason, the topcoat layer according to the present invention is provided to improve the scratch resistance and oil resistance of the laminate, and embodiments provided as a surface layer are preferred. The thickness of the topcoat layer is preferably about 3 to 20 μm.

[0084] Examples of topcoat agents used in the topcoat layer include well-known aqueous treatment agents and oil-based treatment agents. Of these, oil-based treatment agents that exhibit good adhesion to the thermoplastic elastomer layer are preferably used.

[0085] [Adhesive layer] In the present invention, the adhesive layer is preferably provided between the topcoat layer and the thermoplastic elastomer layer, and is provided so as to be in contact with the topcoat layer and the thermoplastic elastomer layer, respectively. The thickness of the adhesive layer is preferably about 3 to 20 μm.

[0086] The adhesive layer according to the present invention preferably contains an adhesive. Adhesives used in the adhesive layer include emulsion-based adhesives and solvent-based adhesives. Examples of emulsion-based adhesives include acrylic ester resins, acrylic ester-vinyl acetate copolymer resins, vinyl acetate resins, ethylene-vinyl acetate copolymer resins, urethane resins, epoxy resins, and synthetic rubbers (SBR, NBR). Examples of solvent-based adhesives include epoxy resins, urethane resins, chloroprene resins, synthetic rubbers (SBR, NBR), vinyl acetate resins, and acrylic ester resins. Of these, a two-component solvent-based adhesive with good adhesion strength is preferred for laminates of industrial parts, and urethane-based adhesives are suitably used.

[0087] [Thermoplastic elastomer layer] The thermoplastic elastomer layer according to the present invention is formed by molding the thermoplastic elastomer composition of the present invention, which contains the aforementioned components (A) and (B). The molding method described above can be applied. In this case, a mixture of the thermoplastic elastomer composition of the present invention, as described later, with another thermoplastic elastomer, thermoplastic resin, various additives, and colorants may be used for molding. Such a mixture is also included in the thermoplastic elastomer composition of the present invention, and a material formed from such a mixture is also included in the thermoplastic elastomer layer according to the present invention.

[0088] [Foam layer] The foam layer according to the present invention is provided for the purpose of imparting flexibility to the laminate, and is preferably provided in contact with the thermoplastic elastomer layer. The foam can be open-cell or closed-cell, but closed-cell is preferred. Furthermore, among closed-cell foams, it is preferable that it contains one or more polyolefins which are electron beam crosslinked. Cross-linked polyolefin foams have excellent heat resistance and thermal insulation properties, and have therefore been used in a wide range of fields as thermal insulation materials, cushioning materials, etc. In particular, in automotive applications, they are used as thermal insulation and interior materials for ceilings, doors, instrument panels, cooler covers, etc. Specific examples include Softlon manufactured by Sekisui Chemical Co., Ltd. and Toraypef manufactured by Toray Industries, Inc.

[0089] [Decorative layer] The laminate of the present invention may further have a decorative layer. The decorative layer according to the present invention is provided for the purpose of enhancing the design and visibility of the laminate, and is preferably provided in contact with the thermoplastic elastomer layer. For example, it can be used in a laminated configuration of a topcoat layer / adhesive layer / thermoplastic elastomer layer / decorative layer / foam layer, or in a laminated configuration of a topcoat layer / adhesive layer / thermoplastic elastomer layer / foam layer / decorative layer. Among these, the configuration in which it is provided in contact with the thermoplastic elastomer layer, i.e., a laminated configuration of a topcoat layer / adhesive layer / thermoplastic elastomer layer / decorative layer / foam layer, is preferred. The decorative layer can take the form of a film or sheet with a pattern, function, or product number.

[0090] [Method for manufacturing laminates] The present invention provides a method for manufacturing a laminate, comprising the steps of: forming a thermoplastic elastomer layer made of a thermoplastic elastomer composition containing the aforementioned components (A) and (B); forming an adhesive layer containing an adhesive on at least one surface of the thermoplastic elastomer layer; and forming a topcoat layer.

[0091] The present invention also provides a method for producing a laminate, comprising the steps of: forming a thermoplastic elastomer layer made of a thermoplastic elastomer composition obtained by melt-kneading a mixture containing the aforementioned components (A), (b), (c), and (d); forming an adhesive layer containing an adhesive on at least one surface of the thermoplastic elastomer layer; and forming a topcoat layer.

[0092] There are no particular limitations on the method for forming the laminate of the present invention, but extrusion molding or calendering is applicable.

[0093] <Process for forming a thermoplastic elastomer layer> The process for forming the thermoplastic elastomer layer may involve methods such as extrusion molding or calendering. To adjust the hardness and color to the desired level, the thermoplastic elastomer composition of the present invention may be used alone or mixed with another thermoplastic elastomer, thermoplastic resin, various additives, colorants, etc., before molding.

[0094] The surface of the thermoplastic elastomer layer obtained in this manner may be corona-treated as needed to improve adhesion with adhesive layers, etc. However, from the viewpoint of reducing costs by streamlining the process and reducing CO2 emissions, it is preferable not to perform corona treatment.

[0095] <Process for forming the adhesive layer> The process of forming the adhesive layer is carried out, for example, by applying the aforementioned adhesive to the thermoplastic elastomer layer. A knife coater, roll coater, spray, brush, roller, or the like can be used as appropriate for applying the adhesive.

[0096] <Process for forming the top coat layer> The process of forming the topcoat layer is carried out, for example, by applying a topcoat agent to the adhesive layer described above. A knife coater, roll coater, spray, brush, roller, or other appropriate method can be used for applying the topcoat agent.

[0097] <Process for forming the foam layer> The process of forming the foam layer is carried out by bonding the structure having the topcoat layer / adhesive layer / thermoplastic elastomer layer obtained above to the foam by heating or using an adhesive.

[0098] <Process for forming the decorative layer> The process of forming the decorative layer is carried out, for example, by bringing the structure having the topcoat layer / adhesive layer / thermoplastic elastomer layer obtained as described above into contact with the decorative layer, such as a film or sheet.

[0099] [Automotive interior skin] The laminate of the present invention is particularly suitable for use in automotive interior surfaces such as instrument panels or door trims.

[0100] Figure 1 is a schematic cross-sectional view of an example of an automotive instrument panel (10), where (1) represents the top coat layer, (2) the adhesive layer, (3) the thermoplastic elastomer layer, (4) the decorative layer, and (5) the foam layer. The thermoplastic elastomer composition of the present invention described above is used in the thermoplastic elastomer layer (3) of the automotive instrument panel (10) described above. [Examples]

[0101] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples unless it exceeds its gist. The various manufacturing conditions and evaluation result values ​​in the following examples have meaning as preferred upper or lower limits in embodiments of the present invention, and the preferred range may be defined by a combination of the aforementioned upper or lower limits and the values ​​of the following examples or the values ​​of the examples themselves.

[0102] [raw materials] The raw materials used in the following examples and comparative examples are as follows:

[0103] <Component (A) (Component (a))> Olefin-based thermoplastic elastomer / Torexplane® TT1001N manufactured by Mitsubishi Chemical Corporation (a thermoplastic elastomer in which olefin rubber is dispersed in an olefin resin matrix) MFR: 22g / 10min (Measurement conditions: 230℃, load 49N) Duro hardness A: 66 (Measurement conditions: ISO 7619)

[0104] <Ingredient (b)> Polytetramethylene ether glycol / PTMG250 manufactured by Mitsubishi Chemical Corporation Number average molecular weight: 225

[0105] <Ingredient (c)> Maleic anhydride / Special grade reagent manufactured by Wako Pure Chemical Industries, Ltd.

[0106] <Ingredient (d)> A mixture of 40% by mass of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane and 60% by mass of calcium carbonate / Trigonox 101-40C manufactured by Nuurion Co., Ltd.

[0107] <Ingredient (E)> Styrene-based thermoplastic elastomer / Kraton G1651H Number average molecular weight: 253,000 Styrene content: 33% by mass

[0108] [Evaluation Method] The evaluation method for the thermoplastic elastomer compositions in the following examples and comparative examples is as follows.

[0109] <Adhesive strength> A thermoplastic elastomer composition was used to form a 1 mm thick sheet at 200°C using a press molding machine (hydraulic jack type heating / cooling press, 200 x 200 mm, manufactured by Toyo Seiki Seisakusho). After corona treatment of the molded sheet surface, a mixture of 100 parts by mass of Laseroid LU-4304 (manufactured by Dainichi Seika Co., Ltd.), a polyurethane resin adhesive, and 5 parts by mass of Laseroid LU-3017(c) (manufactured by Dainichi Seika Co., Ltd.), was applied to the corona-treated surface of the molded sheet to a thickness of approximately 10 μm using a bar coater. The mixture was dried in an 80°C oven for 6 hours and then left to stand at room temperature for 24 hours. Subsequently, a polyurethane tape (width 12 mm) was heat-laminated to the adhesive-coated surface to form Test Specimen 1. In addition, a test specimen 2 was prepared in which an adhesive layer was formed in the same manner as above, without performing corona treatment, and a polyurethane tape was attached. For the obtained test specimens 1 and 2, the adhesive strength between the tape and the sheet was measured using the 180-degree peel test method (test speed 50 mm / min, peel distance approximately 50 mm, maximum test force measured) with a Shimadzu Autograph AG2000, referencing the ISO 8510-2:1990 standard. The adhesion between the sheet made of the thermoplastic elastomer composition and the adhesive was evaluated based on this peel strength. Furthermore, the delamination surface of the test specimen after adhesive strength measurement was observed as the delamination mode. If delamination occurred near the interface between the thermoplastic elastomer composition sheet and the polyurethane tape, it was evaluated as interfacial delamination. If the thermoplastic elastomer composition sheet was fractured, it was evaluated as material fracture. In this evaluation, material fracture means that the adhesion between the thermoplastic elastomer composition sheet and the adhesive is stronger compared to interfacial delamination.

[0110] [Examples / Comparative Examples] <Example 1> 100 parts by mass of component (A), 1.8 parts by mass of component (b), 1 part by mass of component (c), and 0.2 parts by mass of component (d) were added to a small kneader (Laboplastmill 20C-200, mixer R-60H, manufactured by Toyo Seiki Seisakusho) at a temperature setting of 160°C. After homogenization at a rotor speed of 20 rpm, the temperature was raised in the range of 180-210°C, and kneading was performed for 5 minutes at a rotor speed of 100 rpm to obtain pellets of a thermoplastic elastomer composition containing modified polytetramethylene ether glycol modified with maleic anhydride from components (A) and (c). The adhesive strength of the obtained thermoplastic elastomer composition pellets was evaluated. The results are shown in Table 1.

[0111] <Examples 2-3 and Comparative Example 1> A thermoplastic elastomer composition pellet was obtained in the same manner as in Example 1, except for the formulation shown in Table 1. The obtained thermoplastic elastomer composition pellet was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0112] [Table 1]

[0113] <Evaluation Results> As shown in Table 1, Examples 1-3 showed superior adhesion compared to Comparative Example 1 in both Test Specimen 1 and Test Specimen 2. Comparing the results of Test Specimen 2 in Examples 1-3 with the results of Test Specimen 1 in Comparative Example 1, it was confirmed that Examples 1-3 achieved adhesion equivalent to that of Comparative Example 1, which represents the conventional technology. From this, it can be seen that practical adhesion can be obtained in Examples 1-3 without applying corona treatment. [Industrial applicability]

[0114] The laminate of the present invention, having a thermoplastic elastomer layer made of the thermoplastic elastomer composition of the present invention, exhibits excellent adhesive properties and can therefore be used in automotive parts (weatherstrips, ceiling materials, interior seats, bumper moldings, side moldings, air spoilers, hoses, armrests, instrument panels, door trims, console lids, and mats). In particular, it is industrially useful as an instrument panel or door trim for automobiles. Furthermore, since it has sufficient adhesive strength even without corona treatment, it can contribute to reducing CO2 emissions in the manufacturing process of the laminate. [Explanation of symbols]

[0115] (1) Top coat layer (2) Adhesive layer (3) Thermoplastic elastomer layer (4) Foam layer (5) Decorative layer (10) Automotive instrument panel

Claims

1. A laminate comprising, in this order, a top coat layer, an adhesive layer containing a urethane-based adhesive, a thermoplastic elastomer layer made of a thermoplastic elastomer composition containing the following components (A) and (B), and a foam layer, wherein the thermoplastic elastomer composition contains 0.1 to 30 parts by mass of component (B) per 100 parts by mass of component (A). Component (A): Olefin-based thermoplastic elastomer Component (B): Modified polyalkylene ether glycol modified with an acid and / or its derivatives

2. The laminate according to claim 1, wherein the thermoplastic elastomer composition further comprises the following component (E). Component (E): Styrene-based thermoplastic elastomer

3. The laminate according to claim 1 or 2, further comprising a decorative layer between the thermoplastic elastomer layer and the foam layer.

4. Automotive interior surface made of a laminate according to any one of claims 1 to 3.

5. A method for producing a laminate, comprising the steps of: forming a thermoplastic elastomer layer made of a thermoplastic elastomer composition containing the following components (A) and (B); forming an adhesive layer containing a urethane-based adhesive on at least one surface of the thermoplastic elastomer layer; and forming a topcoat layer, wherein the thermoplastic elastomer composition contains 0.1 to 30 parts by mass of component (B) per 100 parts by mass of component (A). Component (A): Olefin-based thermoplastic elastomer Component (B): Modified polyalkylene ether glycol modified with an acid and / or its derivatives

6. The method for producing a laminate according to claim 5, wherein the thermoplastic elastomer composition further comprises the following component (E). Component (E): Styrene-based thermoplastic elastomer

7. A method for producing a laminate, comprising the steps of: forming a thermoplastic elastomer layer made of a thermoplastic elastomer composition obtained by melt-kneading a mixture containing the following components (a), (b), (c), and (d); forming an adhesive layer containing a urethane-based adhesive on at least one surface of the thermoplastic elastomer layer; and forming a topcoat layer, wherein the thermoplastic elastomer composition contains 0.1 to 30 parts by mass of component (b), 0.01 to 5 parts by mass of component (c), and 0.01 to 3 parts by mass of component (d) per 100 parts by mass of component (a). Component (a): Olefin-based thermoplastic elastomer Component (b): Polyalkylene ether glycol Component (c): Acids and / or derivatives thereof Component (d): Peroxide

8. The method for producing a laminate according to claim 7, wherein the thermoplastic elastomer composition further comprises the following component (E). Component (E): Styrene-based thermoplastic elastomer

9. A thermoplastic elastomer composition for bonding adhesive layers, comprising the following components (A) and (B), with component (B) being 0.1 to 30 parts by mass per 100 parts by mass of component (A). Component (A): Olefin-based thermoplastic elastomer Component (B): Modified polyalkylene ether glycol modified with an acid and / or its derivatives

Images