JP2006274080A - Slush molding powder composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a slush molding powder composition which has good weather resistance, chemical resistance, adhesiveness, flexibility, and abrasion resistance, and has powder flowability, melt flowability (moldability), when molded, heat resistance and scratch resistance in an excellent balance. <P>SOLUTION: This slush molding powder composition comprises 0.5 to 20 pts.wt. of inorganic particles (Y) having a particle diameter of 0.1 to 30 μm and 100 pts.wt. of thermoplastic elastomer composition powder (X) having a particle diameter of 1 to 1,000 μm and comprising an acrylic polymer (B) having at least 1.1 functional groups (C) and an acrylic block copolymer (A) having a prescribed mol.wt. and comprising 15 to 50 wt.% of a prescribed methacrylic polymer block (a) and 85 to 50 wt.% of a prescribed acrylic polymer block (b) having acid anhydride groups and/or carboxyl groups. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention uses a powder composition for powder slush molding and a composition thereof having an excellent balance of moldability, heat resistance, weather resistance, chemical resistance, adhesiveness, flexibility, wear resistance and scratch resistance. Related to powder slush moldings.

As a method for molding various interior materials such as automobile interior skins and skin materials, there is a powder slush molding method using a soft powder material. According to this molding method, leather texture, stitches and the like can be easily provided on the product, and this molding method has advantages such as a high degree of design freedom and good design. Furthermore, the product obtained by this molding method has a soft feel. For this reason, this method is widely used for molding the skin of automobile interior parts such as instrument panels, console boxes, and door rims.
Unlike other injection molding and compression molding methods, this molding method does not apply shaping pressure during molding. For this reason, it is necessary to uniformly adhere the powder material to a complex-shaped mold during molding, and it is required to have excellent powder fluidity. At the same time, since the powder adhering to the mold needs to melt and flow even under no pressure to form a film, the melt viscosity is also required to be low.

As a material having such characteristics, a polyvinyl chloride sheet having a sufficient surface hardness and excellent flexibility is widely used. However, since polyvinyl chloride resin contains a large amount of chlorine in the molecule, there is a concern that the burden on the environment is large, and an effective alternative material is required (Patent Document 1).
Therefore, in recent years, a sheet molded product of a thermoplastic elastomer has been developed as an alternative to the polyvinyl chloride resin (Patent Documents 2 to 4). However, a sheet using a polyolefin-based resin or a styrene-based elastomer lacks wear resistance, flexibility, and oil resistance. Further, a sheet using thermoplastic polyurethane has poor moldability and has a problem in terms of cost.
JP-A-5-279485 JP-A-7-82433 Japanese Patent Laid-Open No. 10-30036 JP 2000-103957 A

The object of the present invention is weather resistance, chemical resistance, adhesion, flexibility and wear resistance, and balance of powder fluidity, melt fluidity (moldability), heat resistance and scratch resistance during molding. It is to obtain a powder composition for slush molding excellent in the above.

As a result of intensive studies to solve the above problems, the present inventors have developed a composition in which inorganic particles are externally added to a thermoplastic elastomer composition powder containing a predetermined acrylic block copolymer. Has been found to be effectively solved, and the present invention has been solved.
That is, the present invention comprises 15 to 50% by weight of a methacrylic polymer block (a) having a methacrylic polymer as a main component and a glass transition temperature of 50 to 130 ° C., acrylic acid-n-butyl, acrylic acid. 50 to 100% by weight of at least one monomer selected from the group consisting of ethyl and 2-methoxyethyl acrylate, and different acrylate and / or vinyl monomers 50 to 50% copolymerizable therewith The acrylic polymer block (b) having an acid anhydride group and / or a carboxyl group (b) consisting of 85 to 50% by weight and having a number average molecular weight measured by gel permeation chromatography of 30,000 to 200,000 acrylic block copolymer (A) and at least 1.1 or more reactive functional groups (C) per molecule Inorganic particles (Y) 0.5 having a particle size of 0.1 to 30 μm with respect to 100 parts by weight of the thermoplastic elastomer composition powder (X) having a particle size of 1 to 1000 μm comprising the acrylic polymer (B) having The present invention relates to a powder composition for slush molding formed by externally adding ˜20 parts by weight.
Another embodiment of the present invention relates to an automobile interior skin characterized by powder slush molding of the above composition.

The powder composition for slush molding of the present invention comprises a methacrylic polymer block (a) and an acrylic polymer block (b), and has an acid anhydride group and / or a carboxyl group in the block (b). Thermoplastic elastomer composition powder (X) comprising an acrylic block copolymer (A) and an acrylic polymer (B) having at least 1.1 reactive functional groups (C) in one molecule ) And inorganic particles (Y) having a particle diameter of 0.1 to 30 μm.
The acrylic polymer (B) has at least 1.1 or more reactive functional groups (C) in one molecule, and this functional group (C) is present in the acrylic polymer block (b). The acrylic block copolymer (A) is reacted with the acid anhydride group and the carboxyl group during molding to increase the molecular weight or crosslink.

The inorganic particles (Y) are added to prevent mutual adhesion of the thermoplastic elastomer composition powder (X). As a result, a powder composition for slush molding that hardly causes molding defects due to powder blocking or the like even during slush molding can be obtained.
Hereinafter, each component of the powder composition for slush molding according to the present invention will be described in more detail.

<Acrylic block copolymer (A)>
The acrylic block copolymer (A) constituting the thermoplastic elastomer composition (X) is composed of a methacrylic polymer block (a) that is a hard segment and an acrylic polymer block (b) that is a soft segment. Thus, the methacrylic polymer block (a) provides shape retention during molding, and the acrylic polymer block (b) provides elasticity as an elastomer and meltability during molding. For this purpose, in the acrylic block copolymer (A), the proportion of the methacrylic polymer block (a) is 15 to 50% by weight, and the proportion of the acrylic polymer block (b) is 85 to 50%. Weight%. If the proportion of the methacrylic polymer block (a) is smaller than 15% by weight and the proportion of the acrylic polymer block (b) is larger than 85% by weight, the shape is not retained during molding, and the methacrylic polymer block When the proportion of (a) is larger than 50% by weight and the proportion of the acrylic polymer block (b) is smaller than 50% by weight, the elasticity as an elastomer and the meltability at the time of molding are lowered.

From the viewpoint of the hardness of the composition, when the proportion of the methacrylic polymer block (a) is small, the hardness is low, and when the proportion of the acrylic polymer block (b) is small, the hardness tends to be high. There is. For this reason, the composition ratio between the methacrylic polymer block (a) and the acrylic polymer block (b) needs to be appropriately set in consideration of the required hardness of the elastomer composition. Further, from the viewpoint of processability, when the proportion of the methacrylic polymer block (a) is small, the viscosity is low, and when the proportion of the acrylic polymer block (b) is small, the viscosity tends to be high. . For this reason, the composition ratio of the methacrylic polymer block (a) and the acrylic polymer block (b) needs to be appropriately set in consideration of required processing characteristics.

The molecular weight of the acrylic block copolymer (A) is adjusted so that the number average molecular weight measured by gel permeation chromatography is 30,000 to 200,000. If the molecular weight is smaller than 30,000, sufficient mechanical properties as an elastomer may not be exhibited. Conversely, if the molecular weight is larger than 200,000, processing properties may be deteriorated. In particular, when powder slush molding is performed, it is necessary to flow even under no pressure. However, if the molecular weight is large, the melt viscosity tends to increase and the moldability tends to deteriorate.
Moreover, the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography of the acrylic block copolymer (A) may be 1.8 or less. Preferably, it is 1.5 or less. If Mw / Mn exceeds 1.8, the uniformity of the acrylic block copolymer may deteriorate.

The acrylic block copolymer (A) is a linear block copolymer or a branched (star) block copolymer, and may be a mixture thereof. The structure of such a block copolymer is appropriately selected according to the required physical properties of the acrylic block copolymer (A). However, in terms of cost and ease of polymerization, linear block copolymer Coalescence is preferred.

The linear block copolymer may have any structure. From the viewpoint of the physical properties of the linear block copolymer or the composition, the methacrylic polymer block (a) is a When the acrylic polymer block (b) is expressed as b, (ab) _n- type, b- (ab) _n- type, and (ab) _n- a-type (n is an integer of 1 or more) For example, it is preferably made of at least one acrylic block copolymer selected from the group consisting of 1 to 3). Among these, an ab type diblock copolymer, an abb type triblock copolymer, or a mixture thereof is preferable from the viewpoint of easy handling during processing and physical properties of the composition.
The relationship between the glass transition temperatures of the methacrylic polymer block (a) and the acrylic polymer block (b) constituting the acrylic block copolymer (A) is the glass transition of the methacrylic polymer block (a). When the temperature is Tg _a , and the glass transition temperature of the acrylic polymer block (b) is Tg _b , it is preferable to satisfy the relationship of the following formula in terms of mechanical strength, rubber elasticity, and the like.
Tg _a > Tg _b
The glass transition temperature (Tg) of the methacrylic polymer block (a) and the acrylic polymer block (b) can be measured by DSC (differential scanning calorimetry) or tan δ peak of dynamic viscoelasticity. .

<Methacrylic polymer block (a)>
The methacrylic polymer block (a) is a block obtained by polymerizing a monomer having a methacrylic acid ester as a main component, and is 50 to 100% by weight of the methacrylic acid ester and a vinyl type copolymerizable therewith. It preferably consists of 0 to 50% by weight of monomer. When the proportion of the methacrylic acid ester is less than 50% by weight, the weather resistance, which is a feature of the methacrylic acid ester, may be impaired.

Examples of the methacrylic acid ester constituting the methacrylic polymer block (a) include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, N-pentyl methacrylate, n-hexyl methacrylate, n-heptyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate, Methacrylic acid aliphatic hydrocarbons (eg, alkyl having 1 to 18 carbon atoms) such as stearyl methacrylate; Methacrylic acid alicyclic hydrocarbon esters such as cyclohexyl methacrylate and isobornyl methacrylate; Benzyl methacrylate Etc. Acid aralkyl ester; methacrylic aromatic hydrocarbon ester such as phenyl methacrylate and tolyl methacrylate; methacrylic acid such as 2-methoxyethyl methacrylate and 3-methoxybutyl methacrylate and etheric oxygen Esters with functional group-containing alcohols; trifluoromethyl methacrylate, trifluoromethyl methyl methacrylate, 2-trifluoromethyl ethyl methacrylate, 2-trifluoroethyl methacrylate, 2-perfluoroethyl methacrylate Ethyl, 2-perfluoroethyl-2-perfluorobutyl ethyl methacrylate, 2-perfluoroethyl methacrylate, perfluoromethyl methacrylate, diperfluoromethyl methyl methacrylate, 2-perfluoro methacrylate Methacrylic acid fluorinated alkyl esters such as methyl-2-perfluoroethylmethyl, 2-perfluorohexylethyl methacrylate, 2-perfluorodecylethyl methacrylate, 2-perfluorohexadecylethyl methacrylate, etc. can give. At least one of these is used. Among these, methyl methacrylate is preferable in terms of processability, cost, and availability.

Examples of vinyl monomers copolymerizable with the methacrylic acid ester constituting the methacrylic polymer block (a) include, for example, acrylic acid esters, aromatic alkenyl compounds, vinyl cyanide compounds, conjugated diene compounds, Examples thereof include halogen-containing unsaturated compounds, vinyl ester compounds, maleimide compounds, and the like.

Examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, N-octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, and the like, acrylate aliphatic hydrocarbon (eg, alkyl having 1 to 18 carbon atoms) ester; cyclohexyl acrylate Acrylic acid cycloaliphatic hydrocarbon esters such as isobornyl acrylate; Acrylic aromatic hydrocarbon esters such as phenyl acrylate and toluyl acrylate; Aralkyl acrylates such as benzyl acrylate; 2-methoxyethyl acrylate , An ester of acrylic acid such as 3-methoxybutyl acrylate and a functional group-containing alcohol having etheric oxygen; trifluoromethyl methyl acrylate, 2-trifluoromethyl ethyl acrylate, 2-perfluoroethyl ethyl acrylate, 2-perfluoroethyl-2-perfluorobutylethyl acrylate, 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethylmethyl acrylate, 2-perfluoromethyl-2-perfluoroethyl acrylate Examples thereof include fluorinated alkyl acrylates such as methyl, 2-perfluorohexylethyl acrylate, 2-perfluorodecylethyl acrylate, and 2-perfluorohexadecylethyl acrylate.

Examples of the aromatic alkenyl compound include styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, and the like.
Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.
Examples of the conjugated diene compound include butadiene and isoprene.

Examples of the halogen-containing unsaturated compound include vinyl chloride, vinylidene chloride, perfluoroethylene, perfluoropropylene, and vinylidene fluoride.
Examples of the vinyl ester compound include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, vinyl cinnamate, and the like.
Examples of the maleimide compound include maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide and the like.

These compounds mentioned as vinyl monomers can be used alone or in combination of two or more. These vinyl monomers are appropriately selected in consideration of the glass transition temperature of the methacrylic polymer block (a) described later, the compatibility with the acrylic polymer block (b), and the like.
The glass transition temperature of the methacrylic polymer block (a) is adjusted to 50 to 130 ° C. This is the powder slush molding material, even without load must flow, the cohesive force and glass transition temperature Tg _a of the methacrylic polymer block (a) is increased, is poor formability the higher the melt viscosity while in tends, when the glass transition temperature Tg _a is too low, also have a flowable resin composition is at room temperature, it becomes impossible to retain the properties of the powder.

<Acrylic polymer block (b)>
The acrylic polymer block (b) comprises 50 to 100% by weight of at least one acrylic ester selected from the group consisting of ethyl acrylate, acrylic acid-n-butyl and acrylic acid-2-methoxyethyl, and It consists of 0 to 50% by weight of different copolymerizable acrylic esters and / or vinyl monomers, and contains an acid anhydride group and / or a carboxyl group.
When acrylic acid-n-butyl is used, the molded product obtained from the composition according to the present invention exhibits good rubber elasticity and low temperature characteristics. When ethyl acrylate is used, it exhibits good mechanical properties such as good oil resistance and tensile strength. In addition, when 2-methoxyethyl acrylate is used, good low-temperature characteristics and oil resistance are exhibited, and the surface tackiness of the resin is improved. These may be used alone or in combination of two or more depending on the required properties. In addition, a softness | flexibility and oil resistance may be impaired as the ratio of these acrylic acid esters is less than 50 weight%.

Examples of the acrylic ester different from ethyl acrylate, acrylic acid-n-butyl and acrylic acid-2-methoxyethyl constituting the acrylic polymer block (b) include, for example, a methacrylic polymer block (a). The same monomers as the acrylates exemplified as the monomers constituting can be mentioned. These can be used alone or in combination of two or more thereof.

Examples of vinyl monomers copolymerizable with the acrylic ester constituting the acrylic polymer block (b) include methacrylic ester, aromatic alkenyl compound, vinyl cyanide compound, conjugated diene compound, halogen, and the like. -Containing unsaturated compounds, silicon-containing unsaturated compounds, unsaturated carboxylic acid compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, maleimide compounds, etc., and specific examples thereof include methacrylic polymer blocks The thing similar to the said thing used for (a) can be mention | raise | lifted. These vinyl monomers can be used alone or in combination of two or more. These vinyl monomers are appropriately selected in consideration of the balance of the glass transition temperature and oil resistance required for the acrylic polymer block (b), compatibility with the methacrylic polymer block (a), and the like. Choose the preferred one. For example, acrylonitrile may be copolymerized for the purpose of improving the oil resistance of the composition.

From the viewpoint of rubber elasticity of the composition, the glass transition temperature of the acrylic polymer block (b) is preferably 25 ° C. or lower, more preferably 0 ° C. or lower, and −20 ° C. or lower. Further preferred. When the glass transition temperature of the acrylic polymer block (b) is higher than the temperature of the environment in which the elastomer composition is used, flexibility and rubber elasticity are hardly exhibited.

<Acid anhydride group and carboxyl group>
In the present invention, the acid anhydride group and the carboxyl group usually act as a reaction point or a crosslinking point for the block copolymer to have a high molecular weight or to be crosslinked. The acid anhydride group and the carboxyl group are introduced into the block copolymer in a form in which the acid anhydride group and the carboxyl group are protected with an appropriate protecting group, or a precursor of the acid anhydride group and the carboxyl group, Thereafter, an acid anhydride group and a carboxyl group can be generated by a known chemical reaction.
The content of acid anhydride group and carboxyl group is the cohesive force of acid anhydride group and carboxyl group, reactivity, structure and composition of acrylic block copolymer (A), acrylic block copolymer (A) The number of blocks to be formed is changed depending on the glass transition temperature, and the number needs to be appropriately set as necessary, but is preferably 1.0 or more, more preferably 2.0 per molecule of the block copolymer. That's it. This is because if the number is less than 1.0, the block copolymer tends to be insufficient in improving the heat resistance by increasing the molecular weight or crosslinking.

Incidentally, the cohesive force and glass transition temperature Tg _b of the acrylic polymer block (b) is increased by introducing an acid anhydride group or a carboxyl group, there is a tendency that flexibility, rubber elasticity, low temperature characteristics deteriorate. For this reason, it is preferable to introduce an acid anhydride group and a carboxyl group in a range in which the flexibility, rubber elasticity, and low temperature characteristics of the acrylic block copolymer (A) are not deteriorated. Specifically, it is preferable to introduce the acrylic polymer block (b) after introducing the acid anhydride group or carboxyl group in a range where the glass transition temperature Tg _b is 25 ° C. or less, and 0 ° C. or less. It is more preferable to make it become, and it is still more preferable to make it -20 degrees C or less.
Hereinafter, each of the acid anhydride group and the carboxyl group will be described in more detail.

<Acid anhydride group>
When the composition contains a compound having active protons, the acid anhydride group easily reacts with a reactive functional group such as an epoxy group. The introduction position of the acid anhydride group is not particularly limited, and the acid anhydride group may be introduced into the main chain of the acrylic polymer block (b) or introduced into the side chain. May be. The acid anhydride group is an anhydride of a carboxyl group and is preferably introduced into the main chain from the viewpoint of ease of introduction into the acrylic polymer block (b). It is represented by (1). General formula (1):

(Wherein R ¹ is hydrogen or a methyl group, two R ^{1 s} may be the same or different from each other, n is an integer of 0 to 3, and m is an integer of 0 or 1) Is done.
N in General formula (1) is an integer of 0-3, Preferably it is 0 or 1, More preferably, it is 1. When n is 4 or more, polymerization tends to be complicated, and cyclization of the acid anhydride group tends to be difficult.
As a method for introducing the acid anhydride group, it is preferable that the acid anhydride group is introduced into the acrylic block copolymer in the form of a precursor of the acid anhydride group and then cyclized. In particular, the general formula (2):

(Wherein R ² represents hydrogen or a methyl group; R ³ represents hydrogen, a methyl group or a phenyl group; at least two of the three R ³ are selected from a methyl group and / or a phenyl group; R ³ may be the same or different from each other.) It is preferable that the acrylic block copolymer having at least one unit represented by:
The introduction of the unit represented by the general formula (2) into the acrylic polymer block (b) is obtained by copolymerizing an acrylate or methacrylic acid ester monomer derived from the general formula (2). Can be done. Examples of the monomer include t-butyl (meth) acrylate, isopropyl (meth) acrylate, α, α-dimethylbenzyl (meth) acrylate, α-methylbenzyl (meth) acrylate, It is not limited to these. Among these, (meth) acrylic acid-t-butyl is preferable from the standpoints of availability, ease of polymerization, and ease of acid anhydride group formation.
The formation of the acid anhydride group is preferably performed by heating the acrylic block copolymer having a precursor of the acid anhydride group at a high temperature, and is preferably heated at 180 to 300 ° C. When the temperature is lower than 180 ° C., the acid anhydride group is likely to be insufficiently generated. When the temperature is higher than 300 ° C., the acrylic block copolymer itself having a precursor of the acid anhydride group may be decomposed.

<Carboxyl group>
The carboxyl group easily reacts with a reactive functional group such as an epoxy group. The introduction position of the carboxyl group is not particularly limited, and the carboxyl group may be introduced into the main chain of the acrylic polymer block (b) or may be introduced into the side chain. In view of ease of introduction into the acrylic polymer block (b), it is preferably introduced into the main chain.
When the monomer having a carboxyl group does not poison the catalyst under the polymerization conditions, the introduction of the carboxyl group is preferably carried out by introducing it directly by polymerization. When there is a possibility of deactivating the catalyst during the polymerization, it is preferably carried out by a method of introducing a carboxyl group by functional group conversion.
In the method of introducing a carboxyl group by functional group conversion, the carboxyl group is introduced into the acrylic block copolymer in a form protected with an appropriate protective group or in the form of a functional group that is a precursor of the carboxyl group. The functional group can be generated by a predetermined chemical reaction known in the art.
As a synthesis method of the acrylic block copolymer (A) having a carboxyl group, for example, a functional group that becomes a precursor of a carboxyl group, such as t-butyl (meth) acrylate, trimethylsilyl (meth) acrylate, and the like. A method of synthesizing an acrylic block copolymer containing a monomer having a carboxyl group and generating a carboxyl group by a known chemical reaction such as hydrolysis or acid decomposition (Japanese Patent Laid-Open Nos. 10-298248 and 2001-234146) ) And general formula (2):

(Wherein R ² represents hydrogen or a methyl group; R ³ represents hydrogen, a methyl group or a phenyl group; at least two of the three R ³ are selected from a methyl group and / or a phenyl group; R ³ may be the same or different from each other.) There is a method of introducing an acrylic block copolymer having at least one unit represented by melting and kneading. The unit represented by the general formula (2) is produced by the decomposition of the ester unit at a high temperature to produce a carboxyl group, and a part of the carboxyl group is cyclized. Utilizing this, the carboxyl group can be introduced by appropriately adjusting the heating temperature and time according to the type and content of the unit represented by the general formula (2).
It is also possible to introduce a carboxyl group by hydrolyzing the acid anhydride group described above.

<Method for producing acrylic block copolymer (A)>
The method for producing the acrylic block copolymer (A) is not particularly limited, but it is preferable to use controlled polymerization using an initiator. Examples of controlled polymerization include living anion polymerization, radical polymerization using a chain transfer agent, and recently developed living radical polymerization. Especially, it is preferable to manufacture by living radical polymerization from the point of control of the molecular weight and structure of an acrylic block copolymer.
Living radical polymerization is radical polymerization in which the activity at the polymerization terminal is maintained without loss. In the narrow sense, living polymerization refers to polymerization in which the terminal always has activity, but generally includes pseudo-living polymerization in which the terminal is inactivated and the terminal is in equilibrium. . The definition here is also the latter. Living radical polymerization has been actively researched by various groups in recent years.

Examples thereof include those using a chain transfer agent such as polysulfide, cobalt porphyrin complex (J. Am. Chem. Soc., 1994, 116, 7943), Those using radical scavengers such as nitroxide compounds (Macromolecules, 1994, Vol. 27, 7228), atom transfer radical polymerization using organic halides as initiators and transition metal complexes as catalysts ( Atom Transfer Radical Polymerization (ATRP). In the present invention, there is no particular restriction as to which of these methods is used, but atom transfer radical polymerization is preferred from the viewpoint of ease of control.

Atom transfer radical polymerization is polymerized using an organic halide or sulfonyl halide compound as an initiator and a metal complex having a group 7 element, group 8, group 9, group 10, or group 11 element as a central metal in the periodic table as a catalyst. (For example, Mattyjaszewski et al., Journal of American Chemical Society, J. Am. Chem. Soc., 1995, 117, 5614, Macromolecules (Macromolecules). ), 1995, 28, 7901, Science, 1996, 272, 866, or Sawamoto et al., Macromolecules, 1995, 28, 1721).

According to these methods, in general, the polymerization proceeds in a living manner and the molecular weight distribution is narrow (Mw / M), although the polymerization rate is very high and a radical reaction such as coupling between radicals is likely to occur. Mn = 1.1 to 1.5) polymer is obtained, and the molecular weight can be freely controlled by the charging ratio of the monomer and the initiator.
In the atom transfer radical polymerization method, as the organic halide or sulfonyl halide compound used as an initiator, a monofunctional, difunctional, or polyfunctional compound can be used. These may be properly used depending on the purpose. However, in the case of producing a diblock copolymer, a monofunctional compound is preferable from the viewpoint of easy availability of an initiator, and an aba triblock In the case of producing a copolymer and a b-a-b type triblock copolymer, it is preferable to use a bifunctional compound from the viewpoint of the number of reaction steps and shortening of the time. In the case of production, it is preferable to use a polyfunctional compound in terms of the number of reaction steps and time reduction.

Moreover, it is also possible to use a polymer initiator as the initiator. The polymer initiator is a compound composed of a polymer in which a halogen atom is bonded to the end of a molecular chain among organic halides or sulfonyl halide compounds. Since such a polymer initiator can be produced by a controlled polymerization method other than the living radical polymerization method, a block copolymer obtained by combining polymers obtained by different polymerization methods is obtained. .
Examples of monofunctional compounds include:
C ₆ H ₅ -CH ₂ X,
_{C 6 H 5 -C (H)} (X) -CH 3,
_{C 6 H 5 -C (X)} (CH 3) 2,
R ⁴ —C (H) (X) —COOR ⁵ ,
R ⁴ —C (CH ₃ ) (X) —COOR ⁵ ,
R ⁴ —C (H) (X) —CO—R ⁵ ,
R ⁴ —C (CH ₃ ) (X) —CO—R ⁵ ,
R ⁴ —C ₆ H ₄ —SO ₂ X
And the like.

In the formula, C ₆ H ₅ represents a phenyl group, and C ₆ H ₄ represents a phenylene group (which may be ortho-substituted, meta-substituted, or para-substituted). R ⁴ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. X represents chlorine, bromine or iodine. R ⁵ represents a monovalent organic group having 1 to 20 carbon atoms.
As specific examples of the monofunctional compound, ethyl 2-bromide propionate and butyl 2-bromide propionate are preferable because they are similar to the structure of the acrylate monomer and can easily control polymerization. .

As a bifunctional compound, for example,
_{X-CH 2 -C 6 H 4} -CH 2 -X,
_{X-CH (CH 3) -C} 6 H 4 -CH (CH 3) -X,
_{X-C (CH 3) 2} -C 6 H 4 -C (CH 3) 2 -X,
^{_{X-CH (COOR 6) -}} (CH 2) n -CH (COOR 6) -X,
^{_{X-C (CH 3) (}} COOR 6) - (CH 2) n -C (CH 3) (COOR 6) -X
^{_{X-CH (COR 6) -}} (CH 2) n -CH (COR 6) -X,
^{_{X-C (CH 3) (}} COR 6) - (CH 2) n -C (CH 3) (COR 6) -X,
_{X-CH 2 -CO-CH 2} -X,
X—CH (CH ₃ ) —CO—CH (CH ₃ ) —X,
_{X-C (CH 3) 2} -CO-C (CH 3) 2 -X,
_{X-CH (C 6 H 5} ) -CO-CH (C 6 H 5) -X,
X—CH ₂ —COO— (CH ₂ ) _n —OCO—CH ₂ —X,
_{X-CH (CH 3) -COO-} (CH 2) n -OCO-CH (CH 3) -X,
_{X-C (CH 3) 2} -COO- (CH 2) n -OCO-C (CH 3) 2 -X,
_{X-CH 2 -CO-CO-} CH 2 -X,
_{X-CH (CH 3) -CO} -CO-CH (CH 3) -X,
_{X-C (CH 3) 2} -CO-CO-C (CH 3) 2 -X,
_{X-CH 2 -COO-C 6} H 4 -OCO-CH 2 -X,
_{X-CH (CH 3) -COO} -C 6 H 4 -OCO-CH (CH 3) -X,
_{X-C (CH 3) 2} -COO-C 6 H 4 -OCO-C (CH 3) 2 -X,
_{X-SO 2 -C 6 H 4} -SO 2 -X
And the like.

In the formula, R ⁶ represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. n represents an integer of 0 to 20. C ₆ H ₅ , C ₆ H ₄ and X are the same as described above.
Specific examples of the alkyl group having 1 to 20 carbon atoms, the aryl group having 6 to 20 carbon atoms, and the aralkyl group having 7 to 20 carbon atoms for R ⁶ include the alkyl group having 1 to 20 carbon atoms for R ⁴ , and 6 to 6 carbon atoms. Specific examples of 20 aryl groups and aralkyl groups having 7 to 20 carbon atoms are the same.
As specific examples of the bifunctional compound, bis (bromomethyl) benzene, diethyl 2,5-dibromoadipate and diethyl 2,6-dibromopimelate are preferable from the viewpoint of availability of raw materials.

As the multifunctional compound, for example,
_{C 6 H 3 - (CH 2} -X) 3,
_{C 6 H 3 - (CH (} CH 3) -X) 3,
_{C 6 H 3 - (C (} CH 3) 2 -X) 3,
_{C 6 H 3 - (OCO-} CH 2 -X) 3,
_{C 6 H 3 - (OCO-} CH (CH 3) -X) 3,
_{C 6 H 3 - (OCO-} C (CH 3) 2 -X) 3,
_{C 6 H 3 - (SO 2} -X) 3
And the like.
In the formula, C ₆ H ₃ is a trivalent phenyl group (the positions of the three bonding hands may be any of 1-position to 6-position, and the combination thereof can be appropriately selected), and X is the same as described above. is there.
Specific examples of the polyfunctional compound include, for example, tris (bromomethyl) benzene, tris (1-bromoethyl) benzene, tris (1-bromoisopropyl) benzene and the like. Of these, tris (bromomethyl) benzene is preferable from the viewpoint of availability of raw materials.

In addition, when an organic halide or sulfonyl halide compound having a functional group is used in addition to the group for initiating polymerization, a polymer in which a functional group other than the group for initiating polymerization is easily introduced at the terminal or in the molecule is obtained. It is done. Examples of functional groups other than the group that initiates polymerization include alkenyl groups, hydroxyl groups, epoxy groups, amino groups, amide groups, silyl groups, and the like.
The transition metal complex used as a catalyst for atom transfer radical polymerization is not particularly limited, but preferred are monovalent and zerovalent copper, divalent ruthenium, divalent iron, and divalent nickel. Complex.

Among these, a copper complex is preferable from the viewpoint of cost and reaction control. Examples of the monovalent copper compound include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, cuprous oxide, cuprous perchlorate, and the like. Of these, cuprous chloride and cuprous bromide are preferred from the viewpoint of polymerization control. When a monovalent copper compound is used, 2,2′-bipyridyl or a derivative thereof (for example, 4,4′-dinolyl-2,2′-bipyridyl, 4,4′-di (5- Noryl) -2,2'-bipyridyl and the like; 1,10-phenanthroline, derivatives thereof (for example, 4,7-dinolyl-1,10-phenanthroline, 5,6-dinolyl- 1,10-phenanthroline-based compounds such as 1,10-phenanthroline); polyamines such as tetramethylethylenediamine (TMEDA), pentamethyldiethylenetriamine, and hexamethyl (2-aminoethyl) amine may be added as a ligand. .

The type of catalyst, ligand and activator to be used may be appropriately determined from the relationship between the initiator, monomer and solvent to be used, and the required reaction rate.
Similarly, the amount of catalyst and ligand used may be determined from the relationship between the amount of initiator, monomer and solvent to be used, and the required reaction rate. For example, when trying to obtain a high molecular weight polymer, the initiator / monomer ratio must be smaller than when obtaining a low molecular weight polymer. The reaction rate can be increased by increasing the number of catalysts and ligands. In addition, when a polymer having a glass transition point higher than room temperature is produced, the reaction rate tends to decrease when an appropriate organic solvent is added to lower the viscosity of the system and increase the stirring efficiency. In such a case, the reaction rate can be increased by increasing the number of catalysts and ligands.
Atom transfer radical polymerization can be carried out in the absence of a solvent (bulk polymerization) or in various solvents. Further, in bulk polymerization and polymerization performed in various solvents, the polymerization can be stopped halfway.

Examples of the solvent that can be used include hydrocarbon solvents, ether solvents, halogenated hydrocarbon solvents, ketone solvents, alcohol solvents, nitrile solvents, ester solvents, carbonate solvents, and the like.
The polymerization can be performed in the range of 20 ° C to 200 ° C, and is preferably performed in the range of 50 to 150 ° C.
As a method for polymerizing an acrylic block copolymer, a method of sequentially adding monomers, a method of polymerizing the next block using a polymer synthesized in advance as a polymer initiator, and a separately polymerized polymer by reaction. The method of combining is mentioned. Any of these methods may be used and is appropriately selected according to the purpose. In addition, the method by the sequential addition of a monomer is preferable from the point of the simplicity of a manufacturing process.
The reaction solution obtained by polymerization contains a mixture of a polymer and a metal complex, and an acrylic block copolymer solution can be obtained by removing these.
The polymer solution thus obtained is subsequently subjected to an evaporation operation, whereby the polymerization solvent and unreacted monomers are removed. Thereby, an acrylic block copolymer can be isolated.

<Acrylic polymer (B)>
The acrylic polymer (B) constituting the thermoplastic elastomer composition according to the present invention is a polymer containing at least 1.1 or more reactive functional groups (C) in one molecule. The acrylic polymer (B) improves molding fluidity as a plasticizer during molding of the composition, and at the same time, reacts with an acid anhydride group or carboxyl group in the acrylic block copolymer (A) during molding. It reacts with the group (C) to make the acrylic block copolymer (A) high molecular weight or crosslinked. The number of reactive functional groups (C) referred to here represents the average number of reactive functional groups (C) present in the entire acrylic polymer (B).
The reactive functional group (C) in the acrylic polymer (B) is 1.1 or more, preferably 1.5 or more, more preferably 2.0 or more in the acrylic polymer (B). Let The number includes the reactivity of the reactive functional group (C), the site and mode of the reactive functional group (C), the acid anhydride group and / or the carboxyl group in the acrylic block copolymer (A). Vary depending on the number, location, and mode of the contained. When the content of the functional group (C) is less than 1.1, the effect of the block copolymer as a high molecular weight reaction agent or a crosslinking agent is reduced, and the heat resistance of the acrylic block copolymer (A) is improved. Tends to be insufficient.
The acrylic polymer (B) is obtained by polymerizing one or more acrylic monomers, or one or two or more acrylic monomers and a monomer other than the acrylic monomer. It is preferable that it is obtained by polymerizing.

Examples of the acrylic monomer include acrylic acid esters and methacrylic acid esters described in the section of the methacrylic polymer block (a). Among these, it is preferable to use any one of acrylic acid-n-butyl, ethyl acrylate and acrylic acid-2-methoxyethyl, or a combination of two or more thereof.
The monomer other than the acrylic monomer is not particularly limited as long as it is a monomer copolymerizable with the acrylic monomer, and for example, vinyl acetate, styrene and the like can be used.
In addition, it is preferable that the ratio of the acryloyl group containing monomer component with respect to all the monomer components in an acrylic polymer (B) is 70 weight% or more. When the proportion is less than 70% by weight, the weather resistance is lowered and the compatibility with the acrylic block copolymer (A) tends to be lowered. Moreover, discoloration tends to occur in the molded product.
The molecular weight of the acrylic polymer (B) is not particularly limited, but is preferably a low molecular weight having an average weight molecular weight of 30,000 or less, more preferably 500 to 30,000, and more preferably 500 to 10,000. Those are particularly preferred. If the weight average molecular weight is less than 500, the molded product tends to be sticky. On the other hand, if the weight average molecular weight exceeds 30,000, plasticization of the molded product tends to be insufficient.

The viscosity of the acrylic polymer (B) is preferably 35,000 mPa · s or less when measured with a cone-plate type rotational viscometer (E-type viscometer) at 25 ° C., and 10,000 mPa · s. More preferably, it is 5,000 mPa · s or less. When the viscosity is higher than 35,000 mPa · s, the plasticizing effect of the composition tends to decrease. Although there is no particular lower limit of the preferred viscosity, the normal viscosity of the acrylic polymer is 10 mPa · s or more.
The glass transition temperature Tg of the acrylic polymer (B) is preferably 100 ° C. or less, more preferably 25 ° C. or less, and more preferably 0 ° C. or less when measured by differential scanning calorimetry (DSC). More preferably, it is particularly preferably -30 ° C or lower. When glass transition temperature Tg exceeds 100 degreeC, there exists a tendency for the effect which improves a moldability as a plasticizer to become inadequate, and it exists in the tendency for the softness | flexibility of the molded object obtained to fall.
The acrylic polymer (B) can be obtained by polymerizing by a known predetermined method. The polymerization method may be appropriately selected as necessary. For example, suspension polymerization, emulsion polymerization, bulk polymerization, living anion polymerization, polymerization using a chain transfer agent, and controlled polymerization such as living radical polymerization may be performed. However, controlled polymerization in which a polymer having good weather resistance and heat resistance and a relatively low molecular weight and a small molecular weight distribution is obtained is preferable, and the method using high-temperature continuous polymerization described below is more preferable in terms of cost.

The acrylic polymer (B) is preferably obtained by a polymerization reaction at a temperature of 180 to 350 ° C. At this polymerization temperature, an acrylic polymer having a relatively low molecular weight can be obtained without using a polymerization initiator or a chain transfer agent. For this reason, the acrylic polymer is an excellent plasticizer and has good weather resistance. Specifically, the method by high-temperature continuous polymerization described in JP-A-57-502171, JP-A-59-6207, JP-A-60-215007 and WO01 / 083619, An example is a method in which the monomer mixture is continuously supplied at a constant supply rate into a reactor set to a temperature and a pressure, and an amount of the reaction liquid corresponding to the supply amount is withdrawn.

<Reactive functional group (C)>
Examples of the reactive functional group (C) include an epoxy group, a hydroxyl group, an amino group, and a carboxyl group. Among these functional groups, from the reactivity with the acid anhydride group and carboxy group contained in the acrylic block copolymer (A) and the ease of introduction of the functional group into the acrylic polymer (B), Epoxy groups are preferred.
Introduction of the reactive functional group (C) into the acrylic polymer (B) is, for example, a vinyl monomer having a reactive functional group (C) copolymerizable with a monomer constituting the acrylic polymer. It can be carried out by copolymerizing the body.
Specific examples of the acrylic polymer (B) having a reactive functional group (C) include ARUFON (registered trademark) XG4000, ARUFON UG4000, ARUFON XG4010, ARUFON UG4010, ARUFON XD945, ARUFON XD950 from Toagosei Co., Ltd. , ARUFON UG4030, ARUFON UG4070, etc. can be preferably used. These are acrylic polymers such as all acrylic and acrylate / styrene, and contain 1.1 or more epoxy groups in one molecule.

<Thermoplastic elastomer composition powder (X)>
The powder composition for slush molding of the present invention has a low melt viscosity when molding and excellent melt flowability (moldability), while the block composition of the acrylic thermoplastic elastomer composition powder (X) during heating is low. The acid anhydride group or carboxyl group in the polymer (A) reacts with the functional group (C) in the acrylic polymer (B) to increase the molecular weight of the acrylic block copolymer (A). Crosslinking is preferred. In terms of improving heat resistance, crosslinking is more preferable.
In order to accelerate the reaction during molding, various additives and catalysts may be added to the thermoplastic elastomer composition powder (X) as necessary. For example, it is possible to use a curing agent generally used for epoxy resins such as acid anhydrides such as acid dianhydrides, amines, and imidazoles.

You may mix | blend a filler with thermoplastic elastomer composition powder (X) as needed. Although it does not specifically limit as a filler, From an improvement of mechanical characteristics, a reinforcement effect, a cost surface, etc., an inorganic filler is more preferable, and a titanium oxide, carbon black, a calcium carbonate, a silica, and a talc are more preferable.
When using a filler, the amount added is preferably in the range of 5 to 200 parts by weight, and in the range of 10 to 100 parts by weight, based on 100 parts by weight of the acrylic block copolymer (A). Is more preferable. When the addition amount is less than 5 parts by weight, the reinforcing effect of the obtained molded product may not be sufficient, and when it exceeds 200 parts by weight, the molding of the resulting composition tends to decrease. In addition, a filler can be used 1 type or in combination of 2 or more types.

If necessary, various lubricants may be added to the thermoplastic elastomer composition powder (X) for moldability, mold releasability from the mold, and low friction of the surface of the resulting molded body. You may mix | blend.
Examples of lubricants include fatty acids such as stearic acid and palmitic acid, fatty acid metal salts such as calcium stearate, zinc stearate, magnesium stearate, potassium palmitate and sodium palmitate, polyethylene wax, polypropylene wax, and montanic acid wax. Waxes, low molecular weight polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene, polyorganosiloxanes such as dimethylpolysiloxane, amide-based lubricants such as octadecylamine, alkyl phosphate, fatty acid ester, ethylenebisstearylamide, tetrafluoroethylene Fluorine resin powder such as resin, molybdenum disulfide powder, silicone resin powder, silicone rubber powder, silica and the like can be used. These can be used alone or in combination of two or more. Among these, stearic acid, zinc stearate, calcium stearate, fatty acid ester, and ethylene bisstearyl amide are preferable because of excellent cost and moldability.

When using a lubricant, the addition amount thereof is preferably in the range of 0.1 to 20 parts by weight, and in the range of 0.2 to 10 parts by weight with respect to 100 parts by weight of the acrylic block copolymer (A). Is more preferable. If the amount added is less than 0.1 parts by weight, the effect of improving the moldability and lowering the friction of the resulting molded product may be insufficient. Characteristics and chemical resistance tend to deteriorate. A lubricant can be used alone or in combination of two or more.
Various additives other than the above may be added to the thermoplastic elastomer composition powder (X) as necessary for the purpose of adjusting various properties of the thermoplastic elastomer composition and the molded article to be obtained. Examples of the additive include a stabilizer, a plasticizer, a flexibility imparting agent, a flame retardant, a pigment, an antistatic agent, and an antibacterial and antifungal agent. Among these, examples of the stabilizer include an antioxidant, a light stabilizer, and an ultraviolet absorber.

<Method for producing thermoplastic elastomer composition powder (X)>
There is no restriction | limiting in particular in the manufacturing method of thermoplastic elastomer composition powder (X), A composition can be obtained by using a batch type kneading apparatus or a continuous kneading apparatus. As the batch kneader, for example, a mixing roll, a Banbury mixer, a pressure kneader, or a high shear mixer can be used. Moreover, as a continuous kneading apparatus, a single screw extruder, a twin screw extruder, a KCK extrusion kneader, etc. can be used. Furthermore, existing methods such as a method of mechanically mixing and shaping into pellets can be used.

The temperature at the time of kneading for producing the thermoplastic elastomer composition is preferably a temperature at which the acrylic block copolymer (A) and the acrylic polymer (B) react and the moldability does not deteriorate. The temperature at which the acrylic block copolymer (A) and the acrylic polymer (B) react and the moldability deteriorates depends on the type of acid anhydride group, carboxyl group, functional group (C), amount introduced, acrylic It depends on the composition of the block copolymer (A) and the acrylic polymer (B), the compatibility of the acrylic block copolymer (A) and the acrylic polymer (B), and the like. Here, after obtaining the composition, the temperature at the time of kneading is preferably 200 ° C. or lower, more preferably 180 ° C. or lower, and 150 ° C. or lower in order to enable molding of the composition. More preferably. When the temperature at the time of kneading exceeds 200 ° C., a high molecular weight or a crosslinking reaction occurs during the kneading and the moldability tends to be lowered. However, the temperature may be such that molding is possible even under conditions where high molecular weight and cross-linking occur in part.

As a method for obtaining the thermoplastic elastomer composition powder (X), the block-type or pellet-state thermoplastic elastomer composition processed by the above method is subjected to impact-type fine pulverization such as turbo mill, pin mill, hammer mill, and centrifugal mill. There is a method of pulverizing by a pulverizer using a shearing action by a machine, a fixed blade and a rotary blade. Further, the pulverization is usually performed at room temperature, but can be mechanically pulverized using a refrigerant or a cooling facility.
When the thermoplastic elastomer composition is pulverized, various powders for preventing mutual adhesion may be attached as a pulverization aid to the surface of the composition pellets before pulverization. As the grinding aid, calcium carbonate, talc, kaolin, silicon dioxide, fatty acid amide, fatty acid ester, metal soap and the like can be used. These can be used alone or in combination of two or more. Moreover, the amount is good to set it as about 2-20 weight part with respect to 100 weight part of compositions containing an acryl-type block copolymer (A). If it is less than 2 parts by weight, the effect is not sufficient, and if it is more than 20 parts by weight, the mechanical properties of the resulting composition powder (X) may be adversely affected. The particle size of the grinding aid to be used is not particularly limited. However, if the particle size is too large, the ability to prevent mutual adhesion is low, and if it is fine, the handling property will be reduced. It is preferable to use one having a diameter of 0.5 to 15 μm.
Although most of the pulverization aid remains in the thermoplastic elastomer composition powder obtained by pulverization, a part of the pulverization aid is detached in the pulverization step and separated in the pulverizer.

<External inorganic particles>
In the present invention, in order to improve the handling property and the blocking resistance of the slush molding powder composition, the thermoplastic elastomer composition is made into a powder and then mixed with inorganic particles (Y). .
As the inorganic particles (Y), at least one selected from the group consisting of calcium carbonate, talc, kaolin, and silicon dioxide is used. The amount added is 0.5 to 20 parts by weight. If the amount is less than 0.5 parts by weight, the effect is not sufficient. If the amount is more than 20 parts by weight, the mechanical properties of the obtained powder are adversely affected.

The method of adding the inorganic particles (Y) is not particularly limited, and a method of mixing with a blender, a method of adding in an air stream during transfer, or the like can be employed.
Regarding the inorganic particles (Y) to be used, when the particle diameter is too large, the specific surface area is small, so the effect of addition is low. When the particle diameter is fine, the bulk density is too low and the handling property is lowered. It is necessary to be 1 to 30 μm.

<Method of molding thermoplastic elastomer composition>
Powder slush molding is a method in which a composition powder is poured into a molding die heated to a high temperature, melt-molded, and a cooled and solidified molded body is taken out after a certain period of time. In powder slush molding, it is necessary to flow and melt mold even under no pressure, while the molded body is exposed to a use environment of 100 ° C. or higher. Thus, while the composition must have melt fluidity, the molded body is required to have high heat resistance, and it is difficult to balance moldability and heat resistance. However, in the powder composition for slush molding of the present invention, before molding, the acrylic block copolymer (A) and the acrylic polymer (B) are in an unreacted state, and the acrylic polymer (B) By effectively acting as a plasticizer, it exhibits good meltability in the mold, while acrylic block copolymer (A) and acrylic polymer (B) within a certain time until cooling and solidification. Reacts, and the acrylic block copolymer (A) has high heat resistance after molding by increasing the molecular weight or crosslinking. From this, it can be said that it is a material suitable for powder slush molding.

The powder composition for slush molding according to the present invention is excellent in weather resistance, chemical resistance, adhesiveness, flexibility and wear resistance, and further has powder flowability and melt flowability (moldability) during molding. Excellent balance between heat resistance and scratch resistance. For this reason, the composition of this invention can be used conveniently for powder slush molding. Moreover, since it shows a good scratch property, it can be suitably used as an automobile interior skin.

EXAMPLES Although this invention is demonstrated further in detail based on an Example, this invention is not limited only to these Examples. In the examples, BA, MEA, MMA, and TBA respectively represent -n-butyl acrylate, 2-methoxyethyl acrylate, methyl methacrylate, and t-butyl acrylate. Moreover, the molecular weight described in the examples, the conversion rate of the polymerization reaction, and the evaluation of each physical property were performed according to the following methods.

<Molecular weight measurement method>
The molecular weight shown in this example was measured by the GPC analyzer shown below, and the molecular weight in terms of polystyrene was determined using chloroform as the mobile phase. As a system, a GPC system manufactured by Waters was used, and Shodex (registered trademark) K-804 (polystyrene gel) manufactured by Showa Denko KK was used for the column.

<Method for measuring conversion rate of polymerization reaction>
The conversion rate of the polymerization reaction shown in this example was measured using the following analyzer and conditions.
Equipment used: Gas chromatography GC-14B manufactured by Shimadzu Corporation
Separation column: manufactured by J & W SCIENTIFIC INC, capillary column Supercoux-10, 0.35 mmφ × 30 m
Separation conditions: Initial temperature 60 ° C, hold for 3.5 minutes
Temperature increase rate 40 ° C / min
Final temperature 140 ° C, hold for 1.5 minutes
Injection temperature 250 ° C
Detector temperature 250 ° C
Sample preparation: The sample was diluted about 10 times with ethyl acetate, and butyl acetate or acetonitrile was used as an internal standard substance.

<Glass transition temperature>
The glass transition temperature of the methacrylic polymer block constituting the acrylic block copolymer shows the maximum value of the loss elastic modulus / storage elastic modulus ratio (Tan δ) from 50 ° C. to 130 ° C. in the dynamic viscoelasticity measurement. Measured as temperature.
The measurement is based on JIS K-6394 (Testing method for dynamic properties of vulcanized rubber and thermoplastic rubber). A test piece having a length of 6 mm, a width of 5 mm, and a thickness of 2 mm is cut out and a dynamic viscoelasticity measuring device DVA-200 ( Using IT Measurement Control Co., Ltd.), the measurement frequency was 0.5 Hz.

<Abrasion evaluation test>
A 3 cm × 10 cm sample was cut out from the sheet obtained by slush molding, and an abrasion test was performed with an abrasion tester.
Equipment used: Haydon-type wear tester 14DR (manufactured by Shinto Kagaku Co., Ltd.)
Movement speed: 6000 mm / min Movement length: 5 cm
Number of movements: 5 reciprocating load weight: 1 kg
Wear jig: An ASTM-type jig was fixed to the shaft so that the jig was always parallel to the sample. A semi-cylinder obtained by cutting a cylinder made of aluminum and having a diameter of 2.5 cm and a length of 1 cm in half was bonded to the lower side of the ASTM jig. On top of that, a cloth with a gold width of 3 was attached in a quadruple roll and fixed with an ASTM jig stopper.
The test was conducted, visually observed, and evaluated according to the following criteria.
Things that do not clearly show scratches from the front; ○
Slightly scratched when seen from the front;
Obvious scratches such as whitening and erosion; ×

<Scratch test>
A sample of 10 cm × 10 cm was cut out from a sheet obtained by slush molding and pasted on a mount to obtain a measurement sample. A scratch test was conducted under the following conditions.
Equipment used: Tabers Clutch Tester (Toyo Seiki Seisakusho Co., Ltd.)
Rotation speed: 0.5rpm
Cutter: Tungsten carbide, 4.8 mm square x 19 mm length, cutting edge radius 12.7 mm
Cutter orientation: The cutter was mounted so that the long side of the cutter was on the top so that the blade side of the cutter was on the bottom.
The test was performed with a load of 1 N, visually observed, and evaluated according to the following criteria.
Things that do not clearly show scratches from the front; ○
Slightly scratched when seen from the front;
Obvious scratches such as whitening and erosion; ×

<Ethanol resistance test>
The ethanol resistance shown in the examples and comparative examples was measured under the following conditions.
The textured sheet created in the examples and comparative examples was placed on a flat surface, and one drop of a solution obtained by diluting ethanol (manufactured by Wako Pure Chemical Industries, Ltd.) with pure water to 50% by weight with a pipette. And left at room temperature for 24 hours. Thereafter, the surface was visually observed and evaluated according to the following criteria.
No trace; ○
Traces are visible but not whitened;
What can be bleached; ×

<Oil resistance test>
The oil resistance shown in the examples and comparative examples was measured under the following conditions.
The textured sheet produced in the examples and comparative examples was placed on a flat surface, and one drop of liquid paraffin (manufactured by Nacalai Tesque) was dropped onto the sheet using a pipette and left at 100 ° C. for 24 hours. Thereafter, liquid paraffin was wiped off with Kimwipe (registered trademark) (manufactured by Crecia Co., Ltd.), and the surface was visually observed and evaluated according to the following criteria.
No trace; ○
Traces are visible but not whitened;
What can be bleached; ×

<Heat resistance test>
The heat resistance shown in the examples and comparative examples was measured under the following conditions.
The embossed sheet prepared in Examples and Comparative Examples was allowed to stand at 120 ° C. for 24 hours. Thereafter, the surface was visually observed and evaluated according to the following criteria.
No change in wrinkle pattern; ○
Although the change of the wrinkle pattern is not clear, the surface gloss increased compared to the initial stage;
Changes in wrinkle pattern observed; ×

<Urethane adhesion test>
According to the example, the composition was slush-molded and the skin material was a urethane foam mold (140 mm long × 200 mm wide × 10 mm high lid with a lid, made of SUS304) preliminarily set at 40 ° C. Set. Urethane on which a skin material was set by stirring 17 g of polyisocyanate (CEI-264, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 34 g of polyol (manufactured by Sanyo Chemical Industries, Ltd., HC-150) with a hand mixer at room temperature for 10 seconds. After pouring into the foaming mold, it was capped and allowed to foam for 2.5 minutes. After completion of foaming, a sample was taken out from the foaming mold, and after curing at room temperature for 24 hours, the skin material was peeled off from the foamed urethane by hand to observe the state of destruction, and evaluated according to the following criteria.
Urethane material that has been destroyed; ○
Some breakage occurs at the interface between the sheet and urethane;
Breaking at the interface between the sheet and urethane; ×

<Melability>
The resulting molded sheet was observed on the textured surface and the molded back surface and evaluated according to the following criteria.
Good wrinkle transfer and no pinholes / bubbles: ○
Good texture transfer, no pinholes / bubbles, but some found around the mold: △
Wrinkle transfer is not good, or pinhole / bubbles are recognized even at the center of the mold: ×

<Powder flowability>
The back surface of the obtained molded sheet was observed and evaluated according to the following criteria.
Good powder filling at the corners of the mold and the back of the ribs; ○
Insufficient powder filling at part of mold corner and rib back;
Insufficient powder filling at most corners of mold corners and ribs; x

(Production Example 1)
Synthesis of Acrylic Block Copolymer (A) Precursor The following operation was performed to obtain an acrylic block copolymer (A) precursor. After replacing the inside of the 500 L pressure-resistant reactor with nitrogen, 688 g (4.80 mol) of copper bromide, 78400 g (612 mol) of BA and 2870 g (22.4 mol) of TBA were charged, and stirring was started. Thereafter, a solution prepared by dissolving 1320 g (3.69 mol) of diethyl 2,5-dibromoadipate initiator in 7140 g of acetonitrile (nitrogen bubbling) was charged, and the inner solution was stirred for 30 minutes while raising the temperature to 75 ° C. . When the internal temperature reached 75 ° C., 83.2 g (0.480 mol) of the ligand pentamethyldiethylenetriamine was added to initiate polymerization of the acrylic polymer block.

About 100 mL of the polymerization solution was extracted from the polymerization solution for sampling at regular intervals from the start of polymerization, and the conversion rates of BA and TBA were determined by gas chromatogram analysis of the sampling solution. During polymerization, the polymerization rate was controlled by adding pentamethyldiethylenetriamine as needed. Pentamethyldiethylenetriamine was added twice in total (166 g in total) during the acrylic polymer block polymerization.
When the conversion rate of BA was 99.1% and the conversion rate of TBA was 99.3%, MMA 48300 g (482 mol), EA 7840 g (78.3 mol), copper chloride 475 g (4.80 mol), pentamethyldiethylenetriamine 83.2 g (0.480 mol) and 104000 g of toluene (nitrogen bubbled) were added to initiate polymerization of the methacrylic polymer block.

Sampling was performed when MMA and EA were added, and conversion rates of MMA and EA were determined based on this. After adding MMA and EA, the internal temperature was set to 85 ° C. During polymerization, the polymerization rate was controlled by adding pentamethyldiethylenetriamine as needed. Pentamethyldiethylenetriamine was added a total of 6 times (total 499 g) during methacrylic polymer block polymerization. When the conversion rate of MMA was 95.9%, 250,000 g of toluene was added, and the reactor was cooled to complete the reaction. When the GPC analysis of the obtained block copolymer was conducted, the number average molecular weight Mn was 53100, and molecular weight distribution Mw / Mn was 1.46.
Toluene was added to the resulting reaction solution to make the polymer concentration 25% by weight. 2190 g of p-toluenesulfonic acid was added to this solution, the inside of the reactor was purged with nitrogen, and the mixture was stirred at 30 ° C. for 3 hours. The reaction solution was sampled to confirm that the solution was colorless and transparent, and 6570 g of Radiolite # 3000 manufactured by Showa Chemical Industry Co., Ltd. was added. Thereafter, the reactor was pressurized to 0.1 to 0.4 MPaG with nitrogen, and the solid content was separated using a pressure filter equipped with a polyester felt as a filter medium (filtration area 0.45 m ² ).

Kyoward 500SH1310g was added to about 450kg of the block copolymer solution after filtration, the inside of the reactor was purged with nitrogen, and the mixture was stirred at 30 ° C for 1 hour. The reaction solution was sampled to confirm that the solution was neutral, and the reaction was completed. Thereafter, the reactor was pressurized to 0.1 to 0.4 MPaG with nitrogen, and the solid content was separated using a pressure filter (filter area 0.45 m ² ) equipped with polyester felt as a filter medium to obtain a polymer solution. It was. 675 g of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) was added to the obtained polymer solution and dissolved.

Subsequently, the solvent component was evaporated from the polymer solution. As an evaporator, SCP100 (heat transfer area: 1 m ² ) manufactured by Kurimoto Steel Corporation was used. The evaporation of the polymer solution was carried out by setting the heating medium oil at the evaporator inlet to 180 ° C., the evaporator vacuum to 90 Torr, the screw rotation speed to 60 rpm, and the polymer solution supply rate to 32 kg / h. The polymer is made into a strand with a φ4 mm die through a discharger, cooled in a water tank filled with 3% suspension of Alflow H50ES (main component: ethylenebisstearic acid amide, manufactured by Nippon Oil & Fats Co., Ltd.), and then by a pelletizer. A cylindrical pellet was obtained. In this manner, pellets of the acrylic block copolymer (A) precursor were produced.

(Production Example 2)
1 part by weight of hydrotalcite DHT-4A-2 (Kyowa Chemical Industry Co., Ltd.) is blended as an acid trapping agent with respect to 100 parts by weight of the acrylic block copolymer (A) precursor obtained above. , Using a twin screw extruder with a vent (44 mm, L / D = 42.25) (manufactured by Nippon Steel Works, Ltd.), the rotation speed of 150 rpm, the cylinder temperature of the hopper installation part is 100 ° C., all others are 260 Extrusion kneading was carried out at a temperature setting of 0 ° C. to obtain the target acid anhydride group and carboxyl group-containing acrylic block copolymer. During extrusion, the vent port was closed. At this time, an underwater cut pelletizer (CLS-6-8.1 COMPACT LAB SYSTEM manufactured by GALA INDUSTRIES INC.) Is connected to the tip of the twin-screw extruder, and Alflow (registered) is added to the circulating water of the underwater cut pelletizer. (Trademark) H-50ES (manufactured by NOF Corporation) was added to obtain pellets of spherical acrylic block copolymer 1 (acrylic block copolymer (A)) having no adhesion. .

The conversion efficiency of the t-butyl ester moiety into an acid anhydride group and a carboxyl group was measured by quantifying the amount of isobutylene generated from the t-butyl group by a 280 ° C. thermal decomposition reaction. As a result of the measurement, the conversion efficiency of the obtained resin was 95% or more. The resulting acrylic block copolymer 1 had a Tg of 101 ° C. for the methacrylic polymer block (a).

(Production Example 3)
An acrylic block copolymer 2 was produced according to Production Example 1 except that the reagent amount was changed as follows.
80.5 kg of BA and 0.648 kg of cuprous bromide were charged, and stirring was started. Thereafter, a solution prepared by dissolving 0.904 kg of diethyl 2,5-dibromoadipate in 7.06 kg of acetonitrile was charged, warm water was passed through the jacket, and the inner solution was stirred for 30 minutes while being heated to 75 ° C. When the internal temperature reached 75 ° C., 94.4 mL of pentamethyldiethylenetriamine was added to start polymerization of the first block.
When the conversion rate of BA reached 90%, 80.0 kg of toluene, 0.447 kg of cuprous chloride, 43.2 kg of MMA, and 94.4 mL of pentamethyldiethylenetriamine were added to start polymerization of the second block. When the MMA conversion rate reached 92% and the BA conversion rate reached 98%, 220 kg of toluene was added to dilute the reaction solution, and the reactor was cooled to terminate the polymerization. When the GPC analysis of the obtained block copolymer was conducted, the number average molecular weight Mn was 68300, and molecular weight distribution Mw / Mn was 1.37.
Thereafter, in the same manner as in Production Example 1, a cylindrical pellet of acrylic block copolymer 2 was obtained (acrylic block copolymer (A)). The resulting acrylic block copolymer 2 had a Tg of 96 ° C. for the methacrylic polymer block (a).

Example 1
With respect to 100 parts by weight (100 kg) of the acrylic block copolymer 1 as the acrylic block copolymer (A) obtained in Production Example 2, ARUFON XG4010 (Toagosei Co., Ltd.) as the acrylic polymer (B) ), All acrylic, containing 10 or more epoxy groups per molecule (approximate value 4 (from catalog)), 10 parts by weight, calcium carbonate (Bihoku Flour Industry Co., Ltd., Softon 3200) 43 parts by weight, carbon black (Asahi Carbon Co., Ltd., Asahi # 15) 1.4 parts by weight, lubricant (Nippon Yushi Co., Ltd., beef tallow extremely hardened oil) (Manufactured by Nippon Steel Co., Ltd.), and discharged as a strand at a cylinder temperature of 80 ° C. and a screw rotation speed of 100 rpm, and then a cylindrical pellet by a pelletizer It was a door.

6 parts by weight of silica powder (manufactured by Tatsumori Co., Ltd., microcrystalline soft silica A-10) is attached to the pellet surface with respect to 100 parts by weight of the obtained pellets, and a pulverizer (manufactured by Mitsui Mining Co., Ltd.). A pulverization process was performed using UCM300) to obtain a powder sample. The obtained powder was further sieved using a stainless steel mesh (22 mesh, 710 μm) to obtain a uniform powder. As a result of the composition analysis, 1 part by weight of the added silica powder was removed from the pulverized powder.
2 parts by weight of silica powder (manufactured by Tatsumori Co., Ltd., microcrystalline soft silica A-10, average particle size 2.6 μm) as inorganic particles (Y) at room temperature using a blender To make a powder for slush molding.

Using the obtained powder for slush molding, a small slush molded product for an automobile instrument panel shown in FIG. 1 was molded and evaluated. In addition, ribs are provided on the mold side in order to form grooves in the molded product, so that the powder is difficult to go around in slush molding. The shape of the groove is shown in FIG. The condition was that 6 kg of powder was charged and a small slush molding mold for an automotive instrument panel heated to 260 ° C. was set in a slush molding machine and then cooled to 250 ° C. When the mold reached 250 ° C., it was rotated once at 7.6 rpm in the clockwise direction, and then immediately reversed at the same rotational speed. Then, when the surplus composition was shaken off and 60 seconds passed, the mold was cooled with cooling water for 40 seconds. Further, air cooling was performed, and when the sheet temperature reached 50 ° C., the sheet was peeled off from the mold to obtain a molded sheet (thickness: 1.0 mm). Table 1 shows the results of evaluating the obtained molded sheet.

(Comparative Example 1)
A powder composition was obtained in the same manner as in Example 1 except that the silica powder as the inorganic particles (Y) of Example 1 was not added, and powder slush molding was similarly performed for evaluation. The results are shown in Table 1.

(Comparative Example 2)
43 weight of calcium carbonate (Bihoku Flour & Chemical Co., Ltd., Softon 3200) with respect to acrylic block copolymer 2 (100 parts by weight) as the acrylic block copolymer (A) obtained in Production Example 3 Part, carbon black (Asahi Carbon Co., Ltd., Asahi # 15) at a ratio of 1.4 parts by weight, using a twin screw extruder LABOTEX 30HSS (manufactured by Nippon Steel Works) with a cylinder temperature of 100 ° C. Then, it was discharged as a strand at a screw rotation speed of 100 rpm, and was subsequently formed into a cylindrical pellet by a pelletizer.
6 parts by weight of silica powder (manufactured by Tatsumori Co., Ltd., microcrystalline soft silica A-10) is attached to the pellet surface with respect to 100 parts by weight of the obtained pellets, and a pulverizer (manufactured by Mitsui Mining Co., Ltd.). A pulverization process was performed using UCM150) to obtain a powder sample. The obtained powder was further sieved using a stainless steel mesh (22 mesh, 710 μm) to obtain a uniform powder.
The obtained powder was subjected to powder slush molding in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

As can be seen from a comparison between Example 1 and Comparative Example 2, the slush molding powder composition of the present invention that undergoes a crosslinking reaction during powder slush molding has good meltability during slush molding and high heat resistance. And has an excellent balance between meltability and heat resistance. In addition, the material has good adhesion to urethane foam, scratch resistance and wear resistance. Furthermore, by comparing Example 1 with Comparative Example 1, by adding inorganic particles externally, the powder fluidity is improved, and as a result, the filling property of the powder for slush into the mold during molding is improved. It turns out that it improves. This indicates that even a skin material having a complicated shape can be produced with good shape expression.
As described above, the obtained sheet is excellent in heat resistance, abrasion resistance, and tactile sensation, and is also excellent in polyurethane adhesiveness.

The molded body obtained from the thermoplastic elastomer powder composition of the present invention is excellent in heat resistance, weather resistance, chemical resistance, adhesiveness, flexibility, wear resistance, etc. Tactile materials, materials whose appearance is important, wear-resistant materials, oil-resistant materials, vibration-damping materials, adhesive materials, and other materials such as panels, handles, grips, switches In addition to this, it can be used as a sealing member. The shape can be an arbitrary shape such as a sheet shape, a flat plate shape, or a film shape. As a use, it is suitably used for an automobile interior skin.

Schematic configuration diagram of slush molded product for automotive instrument panel AA sectional view of the slush molded product of FIG.

Claims (2)

15 to 50% by weight of a methacrylic polymer block (a) having a methacrylic polymer as a main component and a glass transition temperature of 50 to 130 ° C., acrylic acid-n-butyl, ethyl acrylate and acrylic acid 50 to 100% by weight of at least one monomer selected from the group consisting of 2-methoxyethyl and 50 to 0% by weight of different acrylate and / or vinyl monomers copolymerizable therewith. And an acrylic polymer block (b) having an acid anhydride group and / or carboxyl group (b) of 85 to 50% by weight, and the number average molecular weight measured by gel permeation chromatography is 30,000 to 200,000. Acrylic block copolymer (A) and acrylic having at least 1.1 or more reactive functional groups (C) in one molecule 0.5 to 20 parts by weight of inorganic particles (Y) having a particle diameter of 0.1 to 30 μm with respect to 100 parts by weight of the thermoplastic elastomer composition powder (X) having a particle diameter of 1 to 1000 μm comprising the coalescence (B) A powder composition for slush molding, which is externally added. An automotive interior skin formed by powder slush molding of the powder composition for slush molding according to claim 1.

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