JP2007246616A - Resin composition for powder molding and molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for powder molding, having excellent antiblocking property, exhibiting good powder fluidity and excellent in fusibility and heat resistance. <P>SOLUTION: The resin composition for powder molding is provided by adding 0.01-30 pts.wt. resin powder (D) to 100 pts.wt. acrylic polymer powder (C), wherein, the resin powder (D) has an average particle diameter of ≤30 μm and smaller than that of the powder (C) and the acrylic polymer powder (C) comprises an acrylic polymer (B) having an average of ≥1.1 epoxy in a molecule, and an acrylic block polymer (A) comprising methacrylic polymer block (a) composed mainly of methacrylic polymer and acrylic polymer block (b) composed mainly of acrylic polymer, and having acid anhydride group and/or carboxy group in at least one polymer block of the methacrylic block (a) and the acrylic polymer block (b). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an acrylic powder molding resin composition having an excellent balance between powder flowability and meltability. The present invention also relates to a composition suitable for powder slush molding and a powder slush molding using the composition.

  Conventionally, soft polyvinyl chloride (hereinafter referred to as PVC) is often used for skin materials such as interior materials. For example, a powder slush molding method, which is a molding method using a powder material, is used. It is used. In this method, i) a soft tactile product can be obtained, ii) leather texture and stitches can be provided on the product, iii) a high-quality skin material with a high degree of design freedom and high design can be formed. , Etc., and is widely used for the skin molding of automobile interior parts such as instrument panels, console boxes and door rims. In this molding method, unlike other molding methods such as injection molding, no shaping pressure is applied during molding. For this reason, the powder material is required to uniformly adhere to a mold having a complicated shape during molding and to form a film by melting the powder adhering to the mold. Further, the skin material and the like are required to have mechanical properties such as tensile strength and elongation, weather resistance, heat resistance, scratch resistance, low temperature characteristics, strain recovery properties, resistance to contactable drugs, and the like.

  PVC is excellent in moldability during powder slush molding. However, since it contains a large amount of halogen atoms, it has a problem of generating toxic gas during combustion. Therefore, in recent years, many olefin-based thermoplastic elastomers and styrene-based thermoplastic elastomers have been proposed as materials to replace these PVCs. These thermoplastic elastomers are relatively inexpensive and excellent in weather resistance and heat resistance. However, it has the disadvantage of being inferior in scratch resistance.

  As a material excellent in scratch resistance, a powder slush molding material made of a thermoplastic urethane elastomer (hereinafter referred to as TPU) has been proposed. TPU is excellent in low temperature characteristics and flexibility in addition to scratch resistance. However, since it is inferior in weather resistance, there is a problem in terms of reliability in applications such as automobile interior parts that are used for a long time.

  Therefore, a powder slash material using an acrylic block copolymer has been proposed as a material for solving the above problems (Patent Document 1). Acrylic block copolymers that have methyl methacrylate as a hard segment and butyl acrylate as a soft segment are known to have properties as thermoplastic elastomers, and the components that make up the block are appropriately selected. By doing so, it is also possible to give an extremely flexible elastomer as compared with other thermoplastic elastomers such as a styrene block body. The acrylic block copolymer is excellent in weather resistance, heat resistance, durability, oil resistance, abrasion resistance, and low temperature characteristics, and further, for example, an acrylic block having a methacryl block and an acrylic block manufactured by an iniferter method. The block copolymer exhibits excellent mechanical properties (Patent Document 2).

  However, the acrylic block copolymers described in Patent Documents 1 and 2 are tacky and cause blocking. For this reason, there is a problem that handling as pellets or powder is difficult and powder characteristics are inferior. For this reason, there has been a demand for the development of powders for automobile interior materials that have good powder flowability and excellent meltability.

International Publication No. 2004/041886 Pamphlet Japanese Unexamined Patent Publication No. 1-26619

  An object of the present invention is to obtain a resin composition for powder molding that is excellent in blocking resistance, exhibits good powder flowability, and is excellent in meltability and heat resistance.

  As a result of intensive studies, the present inventors have solved the above problems.

  That is, the present invention comprises a methacrylic polymer block (a) whose main component is a methacrylic monomer and an acrylic polymer block (b) whose main component is an acrylic monomer. An acrylic block copolymer (A) having an acid anhydride group and / or a carboxyl group in at least one of the polymer block (a) and the acrylic polymer block (b), and in one molecule With respect to 100 parts by weight of the acrylic polymer powder (C) comprising an acrylic polymer (B) having an average of 1.1 or more epoxy groups, the average particle diameter is 30 μm or less, and from the powder (C) The present invention relates to a resin composition for powder molding characterized by adding 0.01 to 30 parts by weight of resin powder (D) having a small average particle size.

  As a preferred embodiment, the resin powder as component (D) is an acrylic resin, an imide resin, a styrene resin, an amide resin, a silicon resin, an olefin resin, an epoxy resin, a urea resin, and a urethane resin. And a resin composition for powder molding, which is at least one resin powder selected from the group consisting of:

  A preferred embodiment includes a resin composition for powder molding characterized in that an acid anhydride group and / or a carboxyl group are present in the main chain of the acrylic polymer block (b).

  As a preferred embodiment, the acrylic block copolymer as the component (A) comprises 10 to 60% by weight of a methacrylic polymer block (a) mainly composed of a methacrylic monomer, Examples thereof include a resin composition for powder molding, comprising 90 to 40% by weight of an acrylic polymer block (b) mainly composed of a monomer.

  In a preferred embodiment, the acrylic polymer block (b) is at least one unit selected from the group consisting of n-butyl acrylate, ethyl acrylate, 2-methoxyethyl acrylate, and 2-ethylhexyl acrylate. A resin composition for powder molding characterized by comprising 50 to 100% by weight of a monomer and a different kind of acrylic acid copolymerizable therewith and 50 to 0% by weight of a vinyl monomer copolymerizable therewith Can be mentioned.

  A preferred embodiment includes a resin composition for powder molding, wherein the glass transition temperature of the methacrylic polymer block (a) is 25 to 130 ° C.

  As a preferred embodiment, the number average molecular weight of the acrylic block copolymer as the component (A) measured by gel permeation chromatography is 30,000 to 200,000. Composition.

  As a preferred embodiment, 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 as the component (A) is 1 And a resin composition for powder molding characterized by being 8 or less.

  A preferred embodiment includes a resin composition for powder molding, wherein the acrylic block copolymer as component (A) is a block copolymer produced by atom transfer radical polymerization.

  A preferred embodiment includes a resin composition for powder molding, wherein the acrylic polymer as the component (B) has a weight average molecular weight of 30,000 or less.

  As a preferred embodiment, there is a resin composition for powder molding characterized in that the acrylic polymer powder (C) has an average particle diameter of 1 μm or more and less than 1000 μm.

  As a preferred embodiment, the present invention relates to a powder slush molding composition comprising the above powder molding resin composition.

  As another embodiment, the present invention relates to a powder slush molded article obtained by powder slush molding the above powder molding resin composition.

  As another embodiment, the present invention relates to an automobile interior skin characterized by powder slush molding of the above powder molding resin composition.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to obtain the resin composition for powder molding which was excellent in blocking resistance and excellent in the balance of powder fluidity | liquidity and a meltability. The composition according to the present invention can be suitably used for powder slush molding, press molding, and other various molding methods. For example, it is possible to produce an automobile interior skin having excellent appearance. Is possible.

  Hereinafter, the present invention will be described in more detail.

  The acrylic polymer powder (C) constituting the resin composition according to the present invention has a methacrylic polymer block (a) containing a methacrylic monomer as a main component and an acrylic monomer as a main component. An acrylic polymer block (b), wherein at least one of the methacrylic polymer block (a) and the acrylic polymer block (b) has an acid anhydride group and / or a carboxyl group. It comprises an acrylic block copolymer (A) having an acrylic polymer (B) having an average of 1.1 or more epoxy groups in one molecule. A resin powder (D) having an average particle diameter of 30 μm or less and an average particle diameter smaller than that of the powder (C) is added to the acrylic polymer powder (C), and the acrylic polymer powder ( The resin powder (D) is adhered to the surface of C). The acid anhydride group or carboxyl group of the acrylic block copolymer (A) and the epoxy group of the acrylic polymer (B) react at the time of molding to increase the molecular weight or crosslink the acrylic block copolymer (A). Let

  Hereinafter, the present invention will be described in more detail.

<Acrylic block copolymer (A)>
The structure of the block copolymer (A) may be linear, branched (star), or a mixture thereof, and the required block copolymer (A). The linear block copolymer is preferable from the viewpoints of cost and ease of polymerization.

The arrangement of the linear block copolymer is not particularly limited. However, from the viewpoint of the physical properties or physical properties of the composition, a methacrylic polymer block (A) constituting the acrylic block copolymer (A) ( a) (hereinafter referred to as polymer block (a) or block (a)) and acrylic polymer block (b) (hereinafter referred to as polymer block (b) or block (b)) have the general formula: (Ab) _n , general formula: a- (ba) _n , general formula: (b-a) _n -b (n is an integer of 1 to 3) It is preferably at least one block copolymer selected. Among these, from the viewpoint of easy handling at the time of processing and physical properties in the case of a composition, an ab type diblock copolymer, an abb type triblock copolymer, or These mixtures are preferred.

  The number average molecular weight of the block copolymer (A) measured by gel permeation chromatography is not particularly limited, but is preferably 30,000 to 500,000, more preferably 50,000 to 400,000. If the number average molecular weight is small, the viscosity is low, and if the number average molecular weight is large, the viscosity tends to be high. Therefore, the viscosity is appropriately set according to the required processing characteristics.

  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 block copolymer is not particularly limited, but is preferably 1.8 or less, more preferably 1 .5 or less. When Mw / Mn exceeds 1.8, the homogeneity of the block copolymer tends to decrease.

  The composition ratio of the methacrylic polymer block (a) and the acrylic polymer block (b) of the block copolymer (A) is 5 to 90% by weight of the methacrylic polymer block (a), and the acrylic weight The combined block (b) is desirably 95 to 10% by weight. When the proportion of the methacrylic polymer block (a) is less than 5% by weight, the shape tends to be difficult to be maintained during molding. When the proportion of the acrylic polymer block (b) is less than 10% by weight, There is a tendency that the elasticity and the meltability at the time of molding are lowered. From the viewpoint of maintaining the shape during molding and elasticity as an elastomer, the composition ratio is 10 to 60% by weight of the methacrylic polymer block (a) and 90 to 40% by weight of the acrylic polymer block (b). The methacrylic polymer block (a) is preferably 15 to 50% by weight, and the acrylic polymer block (b) is more preferably 85 to 50% by weight.

  The hardness of the elastomer composition tends to be low when the proportion of the methacrylic polymer block (a) is small and high when the proportion of the methacrylic polymer block (a) is large. For this reason, the proportion of the methacrylic polymer block (a) may be appropriately set according to the required hardness. Further, the viscosity tends to be low when the proportion of the methacrylic polymer block (a) is small and high when the proportion of the methacrylic polymer block (a) is large. For this reason, the proportion of the methacrylic polymer block (a) may be appropriately set according to required processing characteristics.

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). Assuming that the temperature is Tg _a and the glass transition temperature of the acrylic polymer block (b) is Tg _b , the relationship of the following formula is preferably satisfied 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) is set according to the following Fox formula, and the weight ratio of monomers in each polymer portion is set. Can be performed.
_{1 / Tg = (W 1 /} Tg 1) + (W 2 / Tg 2) + ... + (W m / Tg m)
W ₁ + W ₂ + ... + W _m = 1
(Wherein Tg represents the glass transition temperature of the polymer portion, and Tg ₁ , Tg ₂ ,..., Tg _m represent the glass transition temperatures of the respective polymerization monomers. Also, W ₁ , W ₂ ,. _m represents the weight ratio of each polymerization monomer.)

As the glass transition temperature of each polymerization monomer in the Fox formula, for example, the value described in Polymer Handbook Third Edition (Wiley-Interscience 1989) may be used.
The glass transition temperature can be measured by DSC (differential scanning calorimetry) or tan δ peak of dynamic viscoelasticity, but the polarities of the methacrylic polymer block (a) and the acrylic polymer block (b). May be too close, or if the number of monomer chains in the block is too small, the measured values and the calculation formula based on the Fox formula may deviate.

<Methacrylic polymer block (a)>
The methacrylic polymer block (a) is a block obtained by polymerizing a monomer component mainly composed of a methacrylic acid ester, and 50 to 100% by weight of the methacrylic acid ester in terms of processability and the like. It is preferably composed of 0 to 50% by weight of a copolymerizable vinyl monomer.

  Examples of the methacrylic acid ester constituting the methacrylic polymer block (a) include, for example, methyl methacrylate, ethyl methacrylate, methacrylate-n-propyl, isopropyl methacrylate, and methacrylate-n-. Butyl, isobutyl methacrylate, methacrylate-n-pentyl, methacrylate-n-hexyl, cyclohexyl methacrylate, methacrylate-n-heptyl, methacrylate-n-octyl, methacrylate-2- Ethylhexyl, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate, phenyl methacrylate, toluyl methacrylate, benzyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methacrylate 3-methoxybutyl 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, stearyl methacrylate, glycidyl methacrylate, 2-aminoethyl methacrylate, γ- (methacryloyloxypropyl) trimethoxysilane, γ- (Methacryloyloxypropyl) dimethoxymethylsilane, ethylene oxide adduct of methacrylic acid, trifluoromethylmethyl methacrylate, methacrylic acid-2-trifluoromethylethyl, methacrylic acid-2-perfluoroethylethyl, methacrylic Acid-2-perfluoroethyl-2-perfluorobutylethyl, methacrylic acid-2-perfluoroethyl, perfluoromethyl methacrylate, diperfluoromethylmethyl methacrylate, -2-acrylic methacrylate Oromechiru 2-perfluoroethyl methyl, methacrylic acid-2-perfluorohexylethyl, methacrylic acid-2-perfluorodecyl ethyl, and the like methacrylic acid-2-perfluoroalkyl-hexadecyl ethyl.

  These can be used alone or in combination of two or more. Among these, methyl methacrylate is preferable in terms of processability, cost, and availability. Further, the glass transition point can be increased by copolymerizing isobornyl methacrylate and cyclohexyl methacrylate. Furthermore, methacrylic acid-t-butyl is preferable as a precursor for introducing an acid anhydride to improve heat resistance.

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

  Examples of the acrylate ester include methyl acrylate, ethyl acrylate, acrylic acid-n-propyl, isopropyl acrylate, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic acid-t-butyl, and acrylic acid-n-. Pentyl, acrylate-n-hexyl, cyclohexyl acrylate, acrylate-n-heptyl, acrylate-n-octyl, acrylate-2-ethylhexyl, nonyl acrylate, decyl acrylate, dodecyl acrylate, phenyl acrylate, Toluyl acrylate, benzyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, stearyl acrylate, acrylic acid Guri Ziryl, 2-aminoethyl acrylate, ethylene oxide adduct of acrylic acid, trifluoromethyl methyl acrylate, 2-trifluoromethyl ethyl acrylate, 2-perfluoroethyl ethyl acrylate, 2-acrylic acid-2- Perfluoroethyl-2-perfluorobutylethyl, 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethyl methyl acrylate, 2-perfluoromethyl-2-perfluoroethyl methyl acrylate, acrylic Examples include acid-2-perfluorohexylethyl, 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 silicon-containing unsaturated compound include vinyltrimethoxysilane and vinyltriethoxysilane. Examples of the unsaturated dicarboxylic acid compound include maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid, fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid, and the like. 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 can be used alone or in combination of two or more. These vinyl monomers are appropriately selected from the viewpoints of adjusting the glass transition temperature required for the methacrylic polymer block (a) and compatibility with the acrylic polymer block (b). .

  From the viewpoint of thermal deformation of the elastomer composition, the methacrylic polymer block (a) is preferably designed so that the glass transition temperature is 25 ° C. or higher, more preferably 40 ° C. or higher. More preferably, the temperature is 50 ° C. or higher. When the glass transition temperature of (a) is lower than the temperature of the environment in which the elastomer composition is used, thermal deformation may easily occur due to a decrease in cohesive force.

  From the viewpoints described above, the methacrylic polymer block (a) is mainly composed of methyl methacrylate and for the purpose of controlling the glass transition point, ethyl acrylate, acrylic acid-n-butyl, acrylic acid. A block obtained by polymerizing at least one monomer selected from the group consisting of 2-methoxyethyl and 2-ethylhexyl acrylate is preferable.

<Acrylic polymer block (b)>
The acrylic polymer block (b) is a block obtained by polymerizing a monomer component mainly composed of an acrylate ester. From the viewpoint of rubber elasticity and the like, the acrylate ester block is 50 to 100% by weight and the same. It is preferably composed of 0 to 50% by weight of a polymerizable vinyl monomer.

  Examples of the acrylic acid ester constituting the acrylic polymer block (b) include the same monomers as the acrylic acid ester exemplified as the monomer constituting the methacrylic polymer block (b). it can.

  These may be used alone or in combination of two or more. Among these, acrylic acid-n-butyl is preferable from the viewpoint of rubber elasticity, low temperature characteristics and cost balance. Furthermore, when low temperature characteristics, mechanical characteristics, and compression set are required, 2-ethylhexyl acrylate may be copolymerized. If oil resistance and mechanical properties are required, ethyl acrylate is preferred. Further, when it is necessary to impart low temperature characteristics and oil resistance and to improve the surface tackiness of the resin, 2-methoxyethyl acrylate is preferable. When a balance between oil resistance and low-temperature characteristics is required, a combination of ethyl acrylate, acrylic acid-n-butyl and acrylic acid-2-methoxyethyl is preferred. Furthermore, when introducing an acid anhydride group in order to improve heat resistance, the precursor is preferably tert-butyl acrylate.

  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. Examples thereof include an unsaturated compound containing silicon, an unsaturated compound containing silicon, an unsaturated dicarboxylic acid compound, a vinyl ester compound, and a maleimide compound.

  Methacrylic acid esters, aromatic alkenyl compounds, vinyl cyanide compounds, conjugated diene compounds, halogen-containing unsaturated compounds, silicon-containing unsaturated compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, maleimide compounds The monomer similar to what was illustrated as a monomer which comprises a system polymer block (a) can be mention | raise | lifted.

  These 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.

  The acrylic polymer block (b) preferably has a glass transition temperature of 25 ° C. or lower, more preferably 0 ° C. or lower, and further preferably −20 ° C., from the viewpoint of rubber elasticity of the elastomer composition. It is as follows. If the glass transition temperature of the acrylic polymer block (b) is lower than the temperature of the environment in which the elastomer composition is used, rubber elasticity is easily developed.

  From the viewpoints described above, the acrylic polymer block (b) is at least one selected from the group consisting of -n-butyl acrylate, ethyl acrylate, 2-methoxyethyl acrylate, and 2-ethylhexyl acrylate. In addition, a block obtained by polymerizing 50 to 100% by weight of different acrylates copolymerizable with these and 50 to 0% by weight of vinyl monomers copolymerizable with these is preferable.

  From the viewpoint of rubber elasticity of the elastomer composition, the glass transition temperature of the acrylic polymer block (b) is preferably 25 ° C. or less, more preferably 0 ° C. or less, and further preferably −20 ° C. or less. 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.

  From the viewpoints described above, the acrylic polymer block (b) comprises an acid anhydride group, a carboxyl group or an acid anhydride group, a monomer having a carboxyl group precursor, and acrylic acid-n-butyl, acrylic acid. A block obtained by polymerizing a monomer having at least one selected from the group consisting of ethyl and 2-methoxyethyl acrylate as a main component is preferable.

The Tg _b of the acrylic polymer block (b) can be set by setting the weight ratio of the monomers in each polymer portion according to the Fox formula.

<Acid anhydride group and carboxyl group>
An acid anhydride group and a carboxyl group are added to a methacrylic heavy group in order to maintain mechanical properties at high temperatures while imparting chemical resistance and rubber elasticity to a molded product obtained from the thermoplastic elastomer composition according to the present invention. It is preferable to introduce at least one block copolymer per molecule into the combined block (a) and / or the acrylic polymer block (b). An acid anhydride group and a carboxyl group are the reactivity of an acrylic block copolymer (A) and an acrylic polymer (B), a methacrylic polymer block (a), and an acrylic polymer block (b). Either an acid anhydride group or a carboxyl group may be introduced depending on the cohesive strength and glass transition temperature of the acrylic block copolymer, the required physical properties of the acrylic block copolymer (A), ease of introduction, etc. It is good or may be introduced together.

  In the present invention, the acid anhydride group and the carboxyl group may act as a reaction point with the acrylic polymer (B), and as a reaction point or a crosslinking point for the block copolymer to have a high molecular weight or to be crosslinked. It is preferable to act. 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 in the form of a precursor of the acid anhydride group and the carboxyl group. Later, it can be introduced by generating an acid anhydride group and a carboxyl group 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 on an average per block copolymer molecule, more preferably 2 0 or more. This is because when the number is less than 1.0, there is a tendency that the high molecular weight due to the bimolecular reaction of the block copolymer and the heat resistance improvement due to crosslinking tend to be insufficient.

Note that when improved cohesive force and glass transition temperature Tg _b of the acrylic polymer block (b) 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, when an acid anhydride group and / or a carboxyl group are introduced into the acrylic polymer block (b), the acrylic block copolymer (A) is introduced in a range that does not deteriorate the flexibility, rubber elasticity, and low temperature characteristics. It is preferable to do. Specifically, it is preferably introduced such that the glass transition temperature Tg _b of the acrylic polymer block (b) after introduction of the acid anhydride group or carboxyl group is 25 ° C. or less, more preferably 0 ° C. or less, More preferably, the temperature is set to −20 ° C. or lower.

  Below, an acid anhydride group and a carboxyl group are demonstrated.

<Acid anhydride group>
When the composition contains a compound having active protons, the acid anhydride groups in the methacrylic polymer block (a) and the acrylic polymer block (b) are heated at the predetermined temperatures described below. By this, it reacts easily with the epoxy group in the compound (B). The introduction position of the acid anhydride group is not particularly limited, and the acid anhydride group is introduced into the main chain in the methacrylic polymer block (a) and the acrylic polymer block (b). It may be introduced to the side chain. The acid anhydride group is an anhydride of a carboxyl group, and is introduced into the main chain for ease of introduction into the methacrylic polymer block (a) and the acrylic polymer block (b). Is specifically represented by the general formula (1). General formula (1):

（式中、Ｒ¹は水素またはメチル基で、２つのＲ¹は互いに同一でも異なっていてもよい。ｎは０〜３の整数、ｍは０または１の整数）で表される形で含有される。

(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):

（式中、Ｒ²は水素またはメチル基を表わす。Ｒ³は水素、メチル基またはフェニル基を表わし、３つのＲ³のうち少なくとも２つはメチル基および／またはフェニル基から選ばれ、３つのＲ³は互いに同一でも異なっていてもよい。）で表される単位を少なくとも１つ有するアクリル系ブロック共重合体を溶融混練して、環化導入することが好ましい。

(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 to melt-knead an 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. In the present application, (meth) acrylic acid means acrylic acid or methacrylic acid.

  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 more preferably by heating 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 in the acrylic block copolymer (A) easily reacts with the epoxy group in the compound (B). The introduction position of the carboxyl group is not particularly limited, and the carboxyl group may be introduced into the main chain in the methacrylic polymer block (a) and the acrylic polymer block (b). Although it may be introduced into the side chain, it is preferably introduced into the main chain from the viewpoint of ease of introduction.

  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 the catalyst is deactivated during the polymerization, it is preferably carried out by a method of introducing a carboxyl group by functional group conversion.

  As a method for introducing a carboxyl group by functional group conversion, the carboxyl group is introduced into an acrylic block copolymer in the form of protecting the carboxyl group with an appropriate protecting group or in the form of a functional group that is a precursor of the carboxyl group. A method of generating a functional group by a predetermined chemical reaction known later is mentioned.

  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):

（式中、Ｒ²は水素またはメチル基を表わす。Ｒ³は水素、メチル基またはフェニル基を表わし、３つのＲ³のうち少なくとも２つはメチル基および／またはフェニル基から選ばれ、３つのＲ³は互いに同一でも異なっていてもよい。）で表わされる単位を少なくとも１つ有するアクリル系ブロック共重合体を、溶融混練して導入する方法がある。

(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 melt kneading.

  Moreover, a carboxyl group can also be introduce | transduced by hydrolyzing the said acid anhydride group.

<Method for producing block copolymer (A)>
(polymerization)
Although the manufacturing method of the acrylic block copolymer composition concerning this invention is not specifically limited, It is preferable to use controlled polymerization from a viewpoint that molecular weight can be controlled easily. As the controlled polymerization, an organic alkali metal compound is used as a polymerization initiator and anionic polymerization is performed in the presence of an organoaluminum compound (International Publication No. 2004/041886 pamphlet) or coordinated anionic polymerization is performed using an organic rare earth complex as a polymerization initiator. Examples thereof include a method (Japanese Patent Laid-Open No. 10-298248), radical polymerization using a chain transfer agent, and recently developed living radical polymerization. Among these, living radical polymerization is preferable from the viewpoint of molecular weight and structure control of the block copolymer and ease of production.

  Examples thereof include those using a chain transfer agent such as polysulfide, those using a radical scavenger such as a cobalt porphyrin complex (Journal of American Chemical Society, 1994, 116, 7943) and a nitroxide compound (Macromolecules, 1994). 27, 7228), atom transfer radical polymerization (ATRP) using an organic halide as an initiator and a transition metal complex as a catalyst. In the present invention, which of these methods is used is not particularly limited, but atom transfer radical polymerization is preferable from the viewpoint of ease of control.

  Among them, for example, Matyjaszewski et al., Journal of American Chemical Society, 1995, 117, 5614, and Macromolecules, 1995, 28, 7901, and Science, 1996, 27, 66. As the page and patent literature, the polymerization method disclosed in JP-A-2001-200026 can be preferably used.

(Removal of polymerization catalyst, etc.)
The reaction liquid obtained by polymerization is a mixture of a polymer and a metal complex, and it is necessary to remove the metal complex. The removal method is not particularly limited, but for example, a treatment method disclosed in JP-A-2003-147015 is preferably used.

(Functional group conversion)
In the present invention, an acrylic block copolymer having a carboxyl group or an acid anhydride group introduced by a functional group conversion reaction of the ester portion of the monomer introduced into the polymer block may be used.

  The method for synthesizing the block copolymer having a carboxyl group is not particularly limited. For example, the carboxyl group is generated by the method described in JP-A-10-298248 or JP-A-2001-234146 described above. There is a way. There is also a method of generating a carboxyl group by hydrolyzing a derived acid anhydride group, such as the method described below.

  As a method for synthesizing a block copolymer having an acid anhydride group, the block copolymer having a carboxyl group is subjected to dehydration or dealcoholization reaction by heating, so that an ester site of an adjacent monomer is formed. There is a method of converting to a carboxylic acid anhydride. Alternatively, a block copolymer containing a monomer having a functional group that becomes a precursor of a carboxyl group, such as t-butyl methacrylate, t-butyl acrylate, trimethylsilyl methacrylate, trimethylsilyl acrylate, or the like is synthesized. In addition, there is a method of converting an ester site of an adjacent monomer into a carboxylic acid anhydride by performing a dealcoholization reaction by heating as described above.

  The block copolymer having an acid anhydride group derived by such a method can be hydrolyzed by heating with purified water in an autoclave, for example, and the acid anhydride group can be converted into a carboxyl group. . Hydrolysis can be performed, for example, by heating at 200 ° C. for 2 hours.

  When a t-butyl group is contained in the methacrylic polymer block (a) or the methacrylic polymer block (b), a carboxylic acid group, or a carboxylic acid group and an acid anhydride group are obtained by the above-described method. Can be converted into both.

<Acrylic polymer (B)>
The acrylic polymer (B) constituting the thermoplastic elastomer composition according to the present invention is a polymer containing an average of 1.1 or more epoxy groups 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, The acrylic block copolymer (A) can be increased in molecular weight or crosslinked. The number here represents the average number of epoxy groups present in the entire acrylic polymer (B).

  The epoxy group is contained in the acrylic polymer (B) at 1.1 or more, preferably 1.5 or more, more preferably 2.0 or more. The number depends on the reactivity of the epoxy group, the site and manner in which the epoxy group is contained, and the number, location and manner in which the acid anhydride group or carboxyl group is contained in the acrylic block copolymer (A). Change as appropriate. When the epoxy group content 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 not improved. There is a tendency to become sufficient.

  The acrylic polymer (B) is obtained by polymerizing one or two or more kinds of acrylic monomers, or a single amount other than one or two or more kinds of acrylic monomers and acrylic monomers. It is preferable to be obtained by polymerizing a mixture with the body.

  Examples of acrylic monomers include acryloyl group-containing monomers and methacryloyl group-containing monomers. Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate. , Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, (meth) acrylic Examples thereof include glycidyl acid, methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, phenoxyethyl acrylate, and the like. As the other monomer, a monomer copolymerizable with an acrylic monomer such as vinyl acetate or styrene can be used.

  The acrylic polymer (B) includes an acryloyl group-containing monomer unit. The ratio of the acryloyl group-containing monomer unit to the total monomer unit in the acrylic polymer (B) is preferably 70% by mass or more. When the proportion is less than 70% by mass, the weather resistance of such a polymer is relatively low, and the compatibility with the acrylic block copolymer (A) tends to decrease. Moreover, discoloration tends to occur in the molded product.

  The acrylic polymer (B) is at least one simple substance selected from the group consisting of acrylate-n-butyl, ethyl acrylate, and 2-methoxyethyl acrylate, from the viewpoint of balance between oil resistance and low temperature characteristics. Those composed of 50 to 100% by weight of a monomer and 50 to 0% by weight of different acrylates and / or vinyl monomers copolymerizable therewith are preferred. As the vinyl monomer, styrene is preferable.

  The weight average molecular weight of the acrylic polymer (B) is not particularly limited, but is preferably a low molecular weight of 30,000 or less, more preferably 500 to 30,000, and more preferably 500 to 10,000. Those are particularly preferred. When the weight average molecular weight is less than 500, the molded product tends to be sticky. On the other hand, when the weight average molecular weight exceeds 30,000, plasticization of the molded product becomes 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. A more preferable viscosity is 10,000 mPa · s or less. A particularly preferred viscosity 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) measured by differential scanning calorimetry (DSC) is preferably 100 ° C. or lower, more preferably 25 ° C. or lower, and further preferably 0 ° C. or lower. Yes, 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) is produced by polymerizing by a known predetermined method. The polymerization method may be appropriately selected as necessary. For example, the polymerization may be carried out by a method such as suspension polymerization, emulsion polymerization, bulk polymerization, living anion polymerization, polymerization using a chain transfer agent, and controlled polymerization such as living radical polymerization. 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, a relatively low molecular weight acrylic polymer can be obtained without using a polymerization initiator or a chain transfer agent, so that the acrylic polymer is an excellent plasticizer and has good weather resistance. It is. Specifically, the method by high-temperature continuous polymerization disclosed in JP-A-57-502171, JP-A-59-6207, JP-A-60-215007 and International Publication No. 2001/083619. Illustrated. That is, it is a method in which a mixture of the above monomers is continuously supplied into a reactor set at a predetermined temperature and pressure at a constant supply rate, and an amount of reaction liquid corresponding to the supply amount is withdrawn.

  Specific examples of the acrylic polymer (B) include ARUFON (registered trademark) XG4000, ARUFON UG4000, ARUFON XG4010, ARUFON UG4010, ARUFON XD945, ARUFON XD950, ARUFON UG4030, ARUFON UG40ON, and ARUONON 40, URU70ON from Toagosei Co., Ltd. Can be used for These are acrylic polymers such as all acrylic and acrylate / styrene, and contain 1.1 or more epoxy groups in one molecule.

<Composition for acrylic polymer powder (C)>
The composition for acrylic polymer powder (C) has an acrylic block copolymer (A) having an acid anhydride group and / or a carboxyl group and an average of 1.1 or more epoxy groups per molecule. A thermoplastic elastomer composition comprising an acrylic polymer (B).

  Although the ratio of the blend amount of the acrylic block copolymer (A) and the acrylic polymer (B) contained in the composition for the acrylic polymer powder (C) is not particularly limited, the acrylic polymer (B ) Is preferably 0.1 to 100 parts by weight, more preferably 1 to 50 parts by weight with respect to 100 parts by weight of the acrylic block copolymer (A). If the blending amount of the acrylic polymer (B) is less than 0.1 parts by weight, the crosslinking reaction with the acrylic block copolymer (A) does not proceed sufficiently, and the heat resistance of the molded product may be insufficient. If it is larger than 100 parts by weight, the crosslinking reaction proceeds excessively, and the elongation and flexibility of the molded product may be impaired.

  The composition for the acrylic polymer powder (C) has a low melt viscosity during molding and excellent moldability. On the other hand, an acrylic acid group or carboxyl group reacts with an epoxy group which is a reactive functional group during molding. The system block copolymer (A) is preferably increased in molecular weight or cross-linked, and more preferably cross-linked during molding from the viewpoint of improving heat resistance.

  When crosslinking is required between the acrylic block copolymer (A) and the acrylic polymer (B), there is no particular limitation on the crosslinking method. For example, the acrylic block copolymer (A) and the acrylic polymer A crosslinked polymer can be obtained by using a kneader or the like that can melt-knead the composition containing (B) while heating.

  Various additives and catalysts may be added to the acrylic polymer powder (C) composition as necessary in order to promote the reaction during molding. For example, when the reactive functional group is an epoxy group, it is possible to use a curing agent generally used for epoxy resins such as acid anhydrides such as acid dianhydrides, amines, and imidazoles.

  In addition to the acrylic block copolymer (A) and the acrylic polymer (B), the composition for the acrylic polymer powder (C) includes a stabilizer, a lubricant, and a flame retardant as necessary. , Pigments, fillers, reinforcing agents, tackifiers, and plasticizers can be appropriately blended. Specifically, stabilizers such as hindered phenol, hindered amine and dibutyltin maleate; lubricants such as polyethylene wax, polypropylene wax, montanic acid wax, and beef tallow extremely hardened oil; flame retardants such as decabromobiphenyl and decabromobiphenyl ether Fillers such as carbon black and activated carbon, reinforcing agents; coumarone / indene resins, phenol resins, terpene resins, high styrene resins, petroleum hydrocarbons (eg dicyclopentadiene resins, aliphatic cyclic hydrocarbon resins, unsaturated carbons) Hydrogen resins, etc.), tackifiers such as polybutene and rosin derivatives, adipic acid derivatives, phthalic acid derivatives, glutaric acid derivatives, trimellitic acid derivatives, pyromellitic acid derivatives, polyester plasticizers, glycerin derivatives, epoxy derivatives polyester polymerization type Plasticity , Vinyl polymers obtained by polymerizing vinyl monomers such as polyether polymerization type plasticizers and acrylic plasticizers by various methods, hydroxybenzoic acid esters, N-alkylbenzenesulfonamides, N -Plasticizers such as polymer plasticizers such as alkyltoluenesulfonamides.

<Method for Producing Acrylic Polymer Powder (C)>
Although it does not specifically limit as a manufacturing method of acrylic polymer powder (C) used by this invention, For example, the composition for block-shaped or pellet-shaped acrylic polymer powder (C) is freeze-pulverized, normal temperature grinding | pulverization By pulverizing by the method of method to obtain acrylic polymer powder (C), organic solvents (aliphatic hydrocarbons such as pentane, aromatic hydrocarbons such as toluene, ethers such as diethyl ether, acetic acid Acrylic polymer powder by heating while stirring a polymer solution in which (c) is dissolved in esters such as ethyl, halogenated hydrocarbons such as chloroform), water, and a dispersant. There is a method for obtaining the body (C). (Beading process will be enhanced in the future)
The average particle size of these polymer powders is preferably 1 μm or more and less than 1000 μm. If the particle size is larger than 1000 μm, pinholes are likely to occur in the molded skin, which is not preferable. On the other hand, if it is smaller than 1 μm, the powder fluidity deteriorates, and the powder may not enter the details of the mold at the time of slush molding, which may make molding difficult.

  The average particle size shown in the present invention is a value obtained by sieving the dry spherical powder with a standard sieve and individually weighing the fractions belonging to each particle size range to obtain an average value based on the weight. The average particle diameter can be determined using, for example, an electromagnetic sieve shaker (manufactured by Lecce, AS200BASIC (60 Hz)).

<Resin powder (D)>
In the resin composition for powder molding of the present invention, a resin powder (D) having an average particle size of 30 μm or less and an average particle size smaller than that of the powder (C) is added to the polymer powder (C). Blend. By blending these resin powders into the polymer powder, not only blocking can be prevented, but also the heat resistance of the molded body can be improved. Examples of such resin powder (D) include olefin resins, vinyl chloride resins, acrylic resins, imide resins, styrene resins, amide resins, silicon resins, olefin resins, epoxy resins, urea resins. Preferred examples include resin, guanamine resin, melamine resin and urethane resin powder. Moreover, it is preferable that the addition amount shall be 0.01-30 weight part with respect to acrylic polymer powder (C), More preferably, it is 0.1-25 weight part, More preferably, it is 0.1 weight. Parts to 20 parts by weight. When (D) is less than 0.01 part by weight, the anti-blocking effect is small and the powder fluidity is deteriorated, so that good moldability cannot be obtained. It may cause deterioration and molding defects.

  Moreover, in order to reduce the friction between particles and to improve the blocking resistance, the shape of the resin powder is preferably spherical. Furthermore, the particle size of the resin powder (D) is preferably 0.1 μm or more, more preferably 0.5 μm or more, from the viewpoint of fluidity (powder flowability) of the resin composition for powder molding. In addition, the upper limit is preferably 30 μm or less, more preferably 20 μm or less.

<Use and usage of molded body>
Examples of the molding method of the composition of the present invention include powder slush molding, but other than that, injection molding, injection blow molding, blow molding, extrusion blow molding, extrusion molding, calendar molding, vacuum molding, press molding, etc. It is applicable to.

  The obtained molded article can be suitably used as, for example, a skin material, a tactile sensation material, and an appearance material, and has other purposes such as an abrasion resistant material, an oil resistant material, a vibration damping material, and an adhesive material. It can be used as a material having. As a shape, it can be used as a sheet, flat plate, film, small molded product, large molded product or other arbitrary shape, as a part such as panels, handles, grips, switches, etc. be able to. Although it does not restrict | limit especially as a use, The object for motor vehicles, household electrical appliances, or office electrical appliances are illustrated. For example, automotive skin materials, automotive tactile materials, automotive exterior materials, automotive panels, automotive handles, automotive grips, automotive switches, and household or office electrical panels Examples thereof include switches for household or office electrical appliances. Among these, it is suitably used for 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, MMA, TBA, and EA represent acrylate-n-butyl, methyl methacrylate, tert-butyl acrylate, and ethyl acrylate, respectively.

<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. A Waters GPC system was used as the system, and Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK was used as 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
Sample preparation: The sample was diluted about 3 times with ethyl acetate, and butyl acetate was used as an internal standard.

<Powder fluidity test>
A funnel-shaped metal container was filled with a certain weight of resin powder, and the time from when the bottom lid was opened until the powder completely flowed out was measured. Based on this data, the outflow weight per second was calculated. As an evaluation index of the powder fluidity test, the above calculated value was 1.0 (g / sec) or more: ○, smaller than 1.0 (g / sec): x.

<Melability test>
Powder slush molding:
The obtained powder was subjected to a molding melt test evaluation under the following conditions.
Equipment used: Metal plate with skin wrinkles (plate thickness 4.5mm, wrinkle depth 80%)
Heating conditions: 250 ° C
Heating time: The mold and powder are brought into contact at the first inversion, the mold is inverted after 6 seconds to separate the unmelted powder, the mold is removed after 1 minute, and the cooling start time is within 1 minute (water in the aquarium Cooling by touching)
Meltability evaluation index: The thickness of the molded body is uniform: ○, thickness unevenness is: ×

<Heat resistance test>
The heat resistance shown in the examples and comparative examples was measured under the following conditions.
The embossed sheet prepared in the examples and comparative examples was left at 130 ° 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; ×

(Production Example 1)
[Synthesis of Precursor of Acrylic Block Copolymer 1]
In order to obtain the precursor of the acrylic block copolymer 1, the following operation was performed. After replacing the inside of the 500 L pressure-resistant reactor with nitrogen, 692 g (4.82 mol) of copper bromide, 77,820 g (607 mol) of BA and 3,470 g (27.1 mol) of TBA were charged, and stirring was started. Then, a solution prepared by dissolving 965.1 g (2.68 mol) of diethyl 2,5-dibromoadipate as an initiator in 7140 g of acetonitrile (nitrogen bubbling) was charged, and the inner solution was stirred for 30 minutes, and the temperature was raised to 75 ° C. Allowed to warm. When the internal temperature reached 75 ° C., 83.6 g (0.482 mol) of the ligand pentamethyldiethylenetriamine was added to start polymerization of the acrylic polymer block.

  About 100 mL of the polymerization solution was sampled at regular intervals from the start of polymerization, and the conversion of BA and TBA was determined by gas chromatogram analysis. During the polymerization, the polymerization rate was controlled by adding pentamethyldiethylenetriamine as needed, and pentamethyldiethylenetriamine was added twice in total (167 g in total) during the acrylic polymer block polymerization.

  When the conversion rate of BA is 98.9% and the conversion rate of TBA is 99.0%, MMA 49,590 g (495 mol), EA 8,050 g (80.4 mol), copper chloride 477 g (4.82 mol) Then, 83.6 g (0.482 mol) of pentamethyldiethylenetriamine and 106,860 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 (502 g in total) during block polymerization of the methacrylic polymer. 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 performed, the number average molecular weight Mn was 77,400 and molecular weight distribution Mw / Mn was 1.44. Toluene was added to the resulting reaction solution to make the polymer concentration 25% by weight. 2,203 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 2,650 g of Radiolite # 3000 manufactured by Showa Chemical Industry 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 (filter area 0.45 m ² ) equipped with polyester felt as a filter medium.

(Production Example 2)
[Synthesis of Acrylic Block Copolymer 1]
790 g of Irganox 1010 (manufactured by Ciba Specialty Chemicals) was added to the filtrate obtained by the above method, and TBMA as an internal standard substance was added at 0.1 wt% with respect to 100 wt% of the filtrate. . This solution was heated and stirred at 150 ° C. for 4 hours. After 4 hours, the solution was sampled, it was confirmed that TBMA had disappeared by GC measurement, the reaction was terminated, and the solution was cooled to room temperature.

Kyoward 500SH, 13,150 g, was added to the resulting solution, the inside of the reactor was purged with nitrogen, and the mixture was stirred at 30 ° C for 1 hour. The solution was sampled, and it was confirmed that the solution was neutral. 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. To the obtained polymer solution, 790 g of Irganox 1010 and 1,315 g of hydrotalcite DHT-4A-2 (manufactured by Kyowa Chemical Industry Co., Ltd.) were added as an acid trapping agent.

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 way, a pellet of the acrylic block copolymer 1 was produced.

(Production Example 3)
[Manufacture of acrylic polymer powder]
ARUFON XG4010 (Toagosei Co., Ltd.) as an acrylic polymer (B) to 100 parts by weight of the acrylic block copolymer (A) in 6 kg of the polymer solution shown in Production Example 2 (solid content concentration 25%) Made of acrylic resin, containing 10 or more epoxy groups per molecule (approximately 4 (from catalog)) 10 parts by weight, plasticizer (Asahi Denka Co., RS700) 10 parts by weight After adding, stirring and mixing at a ratio of 0.14 parts by weight of lubricant (manufactured by Nippon Oil & Fats Co., Ltd., beef tallow extremely hardened oil), the mixture was put into a 50 L pressure-resistant stirrer.

  Subsequently, 8 kg of pure water was charged, and 15 g of water-soluble cellulose ether having a cloud point of 90 ° C. (registered trademark 90SH-100, manufactured by Shin-Etsu Chemical Co., Ltd.) was added as a dispersant. The temperature was raised by blowing steam from the bottom of the stirring tank while stirring at 250 rpm using a two-stage four-padded paddle. The solvent gas evaporated by the temperature rise was introduced into the condenser, and the solvent was sequentially recovered. After reaching 100 ° C. and 10 minutes later, the introduction of steam was stopped. The mixture was cooled by passing water through the jacket, and the stirring was stopped after the internal temperature decreased to 60 ° C. The resin slurry produced in the stirring tank was collected. In the obtained powder, particles having a particle diameter of 0.05 to 0.35 mm accounted for 92% of the total powder by weight ratio, and the average particle diameter was 210 μm. The particles having an aspect ratio in the range of 1 to 2 were spherical particles occupying 95% of the total number of particles. The recovered resin slurry was treated at 2000 rpm using a basket type centrifuge (product name: H-110A, manufactured by KOKUSAN) to obtain an acrylic polymer powder having an average particle size of 175 μm.

Example 1
Acrylic polymer powder obtained in Production Example 3; to 100 parts by weight, 6 parts by weight of acrylic resin powder MA1002 (manufactured by Nippon Shokubai Co., Ltd.) having an average particle diameter of about 2 μm is added, and hand blending Then, standing drying (room temperature, 48 hours) was performed to obtain a powdery sample. Using the samples obtained here, a powder fluidity test, heat resistance and meltability were evaluated. The results are shown in Table 1.

(Example 2)
Acrylic polymer powder obtained in Production Example 3; to 100 parts by weight, 6 parts by weight of an amide resin (nylon 12) powder ANYBESTA (manufactured by Ube Industries) having an average particle size of about 6 μm is added. After hand blending, standing drying (room temperature, 48 hours) was performed to obtain a powdery sample. Using the samples obtained here, a powder fluidity test, heat resistance and meltability were evaluated. The results are shown in Table 1.

(Example 3)
Acrylic polymer powder obtained in Production Example 3; 6 parts by weight of urea resin powder organic filler (Nippon Kasei Co., Ltd.) having an average particle diameter of about 3 μm is added to 100 parts by weight, After blending, standing drying (room temperature, 48 hours) was performed to obtain a powder sample. Using the samples obtained here, a powder fluidity test, heat resistance and meltability were evaluated. The results are shown in Table 1.

Example 4
Acrylic polymer powder obtained in Production Example 3; to 100 parts by weight, 6 parts by weight of cellulose resin powder Nikka Rico AS-100S (Nikka Co., Ltd.) having an average particle size of about 20 μm was added, After hand blending, standing drying (room temperature, 48 hours) was performed to obtain a powdery sample. Using the samples obtained here, a powder fluidity test, heat resistance and meltability were evaluated. The results are shown in Table 1.

(Comparative Example 1)
100 parts by weight of the acrylic polymer powder obtained in Production Example 3 was allowed to stand and dry (room temperature, 48 hours) to obtain a powder sample. Using the sample obtained here, a powder fluidity test and an evaluation of meltability were performed. The results are shown in Table 1.

  As can be seen from Table 1 (Examples 1 to 4 and Comparative Example 1), the powder molding resin compositions of Examples 1 to 4 gave good results in powder flowability and meltability. On the other hand, the sample of Comparative Example 1 did not satisfy all of powder flowability and molding meltability.

From the above, it is shown that the resin composition for powder molding of the present invention has an excellent balance of powder flowability, molding meltability and heat resistance as compared with conventional resin compositions for powder molding. It was.

Claims (14)

A methacrylic polymer block (a) having a methacrylic monomer as a main component and an acryl polymer block (b) having an acrylic monomer as a main component, the methacrylic polymer block (a ) And an acrylic block copolymer (A) having an acid anhydride group and / or a carboxyl group in at least one of the polymer blocks (b) and an average of 1.1 per molecule With respect to 100 parts by weight of the acrylic polymer powder (C) composed of the above acrylic polymer having an epoxy group (B), the average particle diameter is 30 μm or less and the average particle diameter is smaller than the powder (C). A resin composition for powder molding characterized by adding 0.01 to 30 parts by weight of a resin powder (D) containing The resin powder as component (D) is at least one selected from acrylic resins, imide resins, styrene resins, amide resins, silicon resins, olefin resins, epoxy resins, urea resins, and urethane resins. The resin composition for powder molding according to claim 1, which is a resin powder. The resin composition for powder molding according to claim 1 or 2, wherein an acid anhydride group and / or a carboxyl group are present in the main chain of the acrylic polymer block (b). The acrylic block copolymer as the component (A) has a methacrylic polymer block (a) of 10 to 60% by weight having a methacrylic monomer as a main component, and an acrylic monomer as a main component. The resin composition for powder molding according to any one of claims 1 to 3, wherein the acrylic polymer block (b) is 90 to 40% by weight. The acrylic polymer block (b) is at least one monomer selected from the group consisting of n-butyl acrylate, ethyl acrylate, 2-methoxyethyl acrylate, and 2-ethylhexyl acrylate, and a copolymer thereof. It consists of 50 to 100% by weight of a different kind of polymerizable acrylic acid ester and 50 to 0% by weight of a vinyl monomer copolymerizable therewith. A resin composition for powder molding. The resin composition for powder molding according to any one of claims 1 to 5, wherein the methacrylic polymer block (a) has a glass transition temperature of 25 to 130 ° C. The number average molecular weight measured by gel permeation chromatography of the acrylic block copolymer as component (A) is 30,000 to 200,000. A resin composition for powder molding. 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 as the component (A) is 1.8 or less. The resin composition for powder molding according to any one of claims 1 to 7. The resin composition for powder molding according to any one of claims 1 to 8, wherein the acrylic block copolymer (A) is a block copolymer produced by atom transfer radical polymerization. . The resin composition for powder molding according to any one of claims 1 to 9, wherein the acrylic polymer as the component (B) has a weight average molecular weight of 30,000 or less. The resin composition for powder molding according to any one of claims 1 to 10, wherein the acrylic polymer powder (C) has an average particle size of 1 µm or more and less than 1000 µm. A powder slush molding composition comprising the powder molding resin composition according to claim 1. A powder slush molded article obtained by powder slush molding of the resin composition for powder molding according to any one of claims 1 to 12. 14. A skin for automobile interior, wherein the powder molding resin composition according to any one of claims 1 to 13 is formed by powder slush molding.