JP2006225563A - Powder for surface skin molding for automobile interiors and surface skin for automobile interiors - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder for surface skin molding for automobile interiors which has excellent melt fluidity and can be suitably used for molding of the surface skin for automobile interiors based on a molding method using the powder such as a powder slush molding method. <P>SOLUTION: (1) A thermoplastic elastomer composition (X) consists of an acrylic block copolymer (A) consisting of 15-50 wt.% of methacrylic polymer block (a) and 85-50 wt.% of acrylic polymer block (b) having an acid anhydride group and/or a carboxyl group, and an acrylic polymer (B) having on average at least 1.1 of reactant functional group in one molecule. (2) A dispersion (Y) comprises a solvent (C), (3) water (D), and (4) a dispersing agent (E). From the thermoplastic elastomer composition (X) and the dispersion (Y), the solvent (C) and the water (D) are removed to obtain a polymer spherical powder composition. Based on 100 pts.wt. of the polymer spherical powder composition, (5) an inorganic particle (F1) is added at the ratio of 0-20 pts.wt. to obtain the powder for the surface skin molding for automobile interiors. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a powder for molding an automobile interior skin and an automobile interior skin.

Skin materials manufactured using a soft polyvinyl chloride resin composition are inexpensive, flexible, and scratch-resistant, so instrument panels, door trims, console boxes, seats, etc. It has been widely used in the field of automobile interior materials. As a method for molding such a skin material, there is a powder slush molding method using a soft powder material. According to this molding method, complex shapes such as leather textures and stitches can be easily molded. In addition, there are advantages such as a high degree of freedom in design and good design. Furthermore, the product molded by this molding method gives a soft touch.

This molding method is different from other molding methods such as injection molding and compression molding, and 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, the powder adhering to the mold needs to melt and flow even under non-pressurization to form a film, so that the melt viscosity of the powder 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, polyvinyl chloride resin generates harmful substances such as dioxins during incineration, and the plasticizers used there are suspected of acting as endocrine disrupting substances and carcinogenic substances. There's a problem. There are also problems such as bleeding out and fogging derived from plasticizers (see, for example, Patent Document 1).

In view of the above, in recent years, it has been studied to perform slush molding using a thermoplastic elastomer containing no halogen or plasticizer instead of polyvinyl chloride resin (Patent Documents 2, 3 and 4). However, a sheet using a polyolefin-based resin or a styrene-based elastomer has poor moldability and has a problem in 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 that powder flowability is good, and it can be suitably used in the molding of automobile interior skins using powder, such as powder slush molding, does not contain halogens and plasticizers, and is environmentally friendly. It does not occur, there is no concern about carcinogenicity, etc., and it is excellent in safety. In addition, abrasion resistance, scratch resistance, solvent resistance (ethanol resistance), oil resistance, heat resistance, urethane adhesion, meltability, moldability, An object of the present invention is to provide a skin molding powder for automobile interior which can form a high quality automobile interior skin having excellent texture and appearance.

The present invention includes (1) a methacrylic polymer block (a) having a glass transition temperature of 50 to 130 ° C. (a) 15 to 50% by weight, acrylic acid-n-butyl, ethyl acrylate and acrylic acid-2-methoxy. It is obtained by polymerizing 50 to 100% by weight of at least one monomer selected from the group consisting of ethyl and 50 to 0% by weight of different acrylates and / or vinyl monomers copolymerizable therewith. And an acrylic polymer block (b) having an acid anhydride group and / or a carboxyl group (b) in an amount of 85 to 50% by weight, and the number average molecular weight measured by gel permeation chromatography is 30,000 to 200,000. An acrylic block copolymer (A);
Acrylic polymer (B) having at least 1.1 or more reactive functional groups (r) on average in one molecule
A thermoplastic elastomer composition (X) comprising:
(2) 0.5 to 10 times weight solvent (C) of the thermoplastic elastomer composition (X),
(3) 0.5 to 5 times weight of water (D) of the thermoplastic elastomer composition (X),
(4) At least one dispersion selected from the group consisting of 0.1 to 5 parts by weight of a water-soluble cellulose ester and 5 to 50 parts by weight of calcium carbonate with respect to 100 parts by weight of the thermoplastic elastomer composition (X). Agent (E)
To 100 parts by weight of polymer spherical powder obtained by removing the solvent (C) and water (D) from the dispersion (Y) containing
(5) It relates to a powder for molding an automobile interior skin, to which 0 to 20 parts by weight of inorganic particles (F1) are added.

In the automotive interior skin molding powder of the present invention, the dispersion (Y) is an inorganic particle (F2) 0 having a particle diameter of 0.1 to 30 μm with respect to 100 parts by weight of the thermoplastic elastomer composition (X). It is preferable to contain 5-20 weight part.

In the polymer spherical powder, 90% or more of the total number of powder particles has an aspect ratio of 1 to 2 expressed as a ratio of the minor axis to the major axis of the particles, and
The average particle diameter is preferably 1 μm or more and less than 1000 μm.

The present invention also relates to an automobile interior skin formed by powder slush molding of the above-mentioned automotive interior skin molding powder.

Since this invention consists of the above-mentioned structure, the powder for skin molding for motor vehicle interior suitable for powder slush molding with high powder fluidity | liquidity can be provided.

The present invention is described in detail below.

The thermoplastic elastomer composition (X) used in the present invention comprises an acrylic block copolymer (A) and an acrylic polymer (B). Here, the acrylic block copolymer (A) is a methacrylic polymer block (a) having a glass transition temperature of 50 to 130 ° C., 15 to 50% by weight, acrylic acid-n-butyl, and ethyl acrylate. And 50 to 100% by weight of at least one monomer selected from the group consisting of 2-methoxyethyl acrylate and 50 to 0% by weight of different acrylates and / or vinyl monomers copolymerizable therewith The acrylic polymer block (b) having an acid anhydride group and / or a carboxyl group (b) is formed in an amount 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. The acrylic polymer (B) is an acrylic polymer having an average of 1.1 or more reactive functional groups (r) in one molecule.

<Methacrylic polymer block (a)>
The methacrylic polymer block (a) is a block formed by polymerizing a monomer having a methacrylic acid ester as a main component. Here, “having a methacrylic ester as a main component” means that the content of the methacrylic ester is the highest among all the monomer components constituting the methacrylic polymer block (a). In particular, the block (a) preferably comprises 50% by weight or more of methacrylic acid ester, and comprises 50 to 100% by weight of methacrylic acid ester and 0 to 50% by weight of other vinyl monomers copolymerizable therewith. Is more preferable. Moreover, you may contain the monomer which has a reactive functional group as a methacrylic ester and / or as another vinyl-type monomer. When the proportion of the methacrylic acid ester is less than 50% by weight, the weather resistance or the like that is characteristic 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, methacrylic acid. Methacrylic acid aliphatic hydrocarbons such as n-hexyl acid, n-heptyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate, stearyl methacrylate (for example, carbon number 1-18 alkyl) esters; methacrylic acid alicyclic hydrocarbon esters such as cyclohexyl methacrylate and isobornyl methacrylate; aralkyl methacrylates such as benzyl methacrylate; phenyl methacrylate, methacrylate Methacrylic acid aromatic hydrocarbon ester such as tolyl acid; ester of methacrylic acid such as 2-methoxyethyl methacrylate and 3-methoxybutyl methacrylate and functional group-containing alcohol having etheric oxygen; trifluoromethyl methacrylate, methacrylic acid Trifluoromethyl methyl acid, 2-trifluoromethyl ethyl methacrylate, 2-trifluoroethyl methacrylate, 2-perfluoroethyl ethyl methacrylate, 2-perfluoroethyl-2-perfluorobutyl ethyl methacrylate, methacrylic acid 2 -Perfluoroethyl, perfluoromethyl methacrylate, diperfluoromethyl methyl methacrylate, 2-perfluoromethyl 2-perfluoroethyl methyl methacrylate, 2-perfluorohexyl ethyl methacrylate, methacrylate Le acid 2 perfluorodecyl ethyl, and methacrylic acid fluorinated alkyl esters such as methacrylic acid 2-perfluoroalkyl-hexadecyl ethyl. These can be used alone or in combination of two or more thereof. 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, and halogen-containing compounds. Examples include unsaturated compounds, unsaturated carboxylic acid compounds, unsaturated dicarboxylic acid 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 alicyclic hydrocarbon esters such as isobornyl acrylate; aromatic acrylic hydrocarbon esters such as phenyl acrylate and toluyl acrylate; aralkyl acrylates such as benzyl acrylate; 2-methoxyethyl acrylate, acrylic Esters of acrylic acid such as 3-methoxybutyl and functional group-containing alcohols having etheric oxygen; trifluoromethyl methyl acrylate, 2-trifluoromethyl ethyl acrylate, 2-perfluoroethyl ethyl acrylate, acrylic acid 2 -Perfluoroethyl-2-perfluorobutylethyl, 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethyl methyl acrylate, 2-perfluoromethyl-2-perfluoroethyl methyl acrylate, acrylic Examples thereof include fluorinated alkyl acrylates such as 2-perfluorohexylethyl acid, 2-perfluorodecylethyl acrylate, 2-perfluorohexadecylethyl acrylate, and the like.

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 unsaturated carboxylic acid compound include methacrylic acid and acrylic acid.

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 selected from the viewpoints of glass transition temperature required for the methacrylic polymer block (a), compatibility with the acrylic polymer block (b), and the like. Further, these monomers may have a reactive functional group such as an acid anhydride group or a carboxyl group.

The glass transition temperature of the methacrylic polymer block (a) is 50 to 130 ° C. When the glass transition temperature is lower than 50 ° C., the heat resistance of the automobile interior skin after molding is inferior, and there is a risk of deformation when the interior of the automobile becomes hot in summer or the like. Moreover, since it will become difficult to fuse | melt when it exceeds 130 degreeC, there exists a tendency for a moldability to deteriorate. Preferably it is 55-120 degreeC, More preferably, it is 60-110 degreeC, More preferably, it is 65-100 degreeC.

The glass transition temperature (Tg) of the polymer (methacrylic polymer block (a) and acrylic polymer block (b) described later) is set according to the following Fox formula, and the weight of the monomer of each polymer portion This can be done by setting the ratio.
_{1 / Tg = (W 1 /} Tg 1) + (W 2 / Tg 2) + ... + (W m / Tg m)
W ₁ + W ₂ + ... + W _m = 1
In the formula, Tg represents the glass transition temperature of the polymer portion, and Tg ₁ , Tg ₂ ,..., Tg _m represent the glass transition temperature of each polymerization monomer. W ₁ , W ₂ ,..., W _m represent the weight ratio of each polymerization monomer.

The glass transition temperature of each polymerization monomer in the Fox formula may be, for example, a value described in Polymer Handbook Third Edition (Wiley-Interscience 1989).

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). If they are too close, or if the number of monomer chains in the block is too small, the measured values may be misaligned with the calculation formula based on the Fox formula.

<Acrylic polymer block (b)>
The acrylic polymer block (b) is composed of 50 to 100% by weight of at least one monomer selected from the group consisting of acrylic acid-n-butyl, ethyl acrylate, and 2-methoxyethyl acrylate. It is formed from 50 to 0 weight of a different kind of polymerizable acrylic ester and / or vinyl monomer. Powder that is a characteristic when an acrylate ester is used when the ratio of at least one selected from the group consisting of n-butyl acrylate, ethyl acrylate, and 2-methoxyethyl acrylate is less than 50% by weight Physical properties, particularly flexibility and oil resistance, may be impaired.

The above-mentioned acrylate-n-butyl, ethyl acrylate, and 2-methoxyethyl acrylate can be used alone or in combination of two or more thereof. Among these, acrylate-n-butyl is preferable from the viewpoint of rubber elasticity, low temperature characteristics, and cost balance. 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. Further, 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 preferable.

Although it does not specifically limit as a dissimilar acrylic ester and / or vinyl-type monomer copolymerizable with acrylic acid-n-butyl, ethyl acrylate, or 2-methoxyethyl acrylate, The above-mentioned acrylic ester (acrylic) Acid-n-butyl, ethyl acrylate or 2-methoxyethyl acrylate), methacrylic acid ester, aromatic alkenyl compound, vinyl cyanide compound, conjugated diene compound, halogen-containing unsaturated compound, unsaturated carboxylic acid Examples include compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, maleimide compounds, and the like.

<Acid anhydride group and / or carboxyl group>
The acrylic polymer block (b) has an acid anhydride group and / or a carboxyl group. By introducing an acid anhydride group and / or a carboxyl group into the acrylic polymer block (b) as a crosslinking point, high rubber elasticity and compression set characteristics can be imparted to the automobile interior skin.

When the number of acid anhydride groups and / or carboxyl groups is two or more, the mode in which the monomers are polymerized may be random copolymerization or block copolymerization. An example of the a-b-a type triblock copolymer is a- (b / z) -a type, (a / z)-(b / z)-(a / z) type, etc. It may be. Here, z represents a monomer or polymer block containing an acid anhydride group and / or a carboxyl group, and (b / z) represents an acid anhydride group and / or an acrylic polymer block (b). Or it represents that the monomer containing a carboxyl group is copolymerized.

In the present invention, the acid anhydride group and / or the carboxyl group act as a reaction point or a crosslinking point for the acrylic block copolymer (A) to have a high molecular weight or to be crosslinked. Compared with other functional groups, the acid anhydride group and / or carboxyl group can be easily introduced into the acrylic block copolymer (A), and in terms of cost and reaction balance between low and high temperatures. Preferred functional groups.

These acid anhydride groups and / or carboxyl groups are introduced into the acrylic polymer block (b) in a form protected with an appropriate protecting group or as a precursor of an acid anhydride group and / or carboxyl group. Then, it can be converted into an acid anhydride group and / or a carboxyl group by a known chemical reaction.

The content of the acid anhydride group and / or carboxyl group is not particularly limited, and the cohesive force of the acid anhydride group and / or carboxyl group, reactivity, the structure and composition of the acrylic block copolymer (A), acrylic It can be set as appropriate depending on the number of blocks constituting the block copolymer (A), the glass transition temperature, and the site and manner in which the acid anhydride group and / or carboxyl group is contained. When the content of the acid anhydride group and / or carboxyl group is too small, the reaction between the acrylic block copolymer (A) and the acrylic polymer (B) is not sufficiently performed, and due to high molecular weight or crosslinking. Since the improvement in heat resistance tends to be insufficient, the acrylic polymer block (b) preferably contains at least 1.0 per block and contains 1.2 or more. Is more preferable, and 1.5 or more are particularly preferable.

The acid anhydride group and / or carboxyl group may be contained only in the acrylic polymer block (b), or both of the methacrylic polymer block (a) and the acrylic polymer block (b). It may be contained in. Reaction point of acrylic block copolymer (A), block constituting acrylic block copolymer (A) (only acrylic polymer block (b), or methacrylic polymer block (a) and acrylic Depending on the purpose, such as the cohesive strength and glass transition temperature of the polymer block (b) and the required physical properties of the acrylic block copolymer (A), and / or carboxyl groups. It can be determined whether or not the group is also contained in the methacrylic polymer block (a). When it is necessary to improve the heat resistance and heat decomposability of the acrylic block copolymer (A), it is preferably introduced into the methacrylic polymer block (a).

It is preferable to introduce the acid anhydride group and / or carboxyl group in such a range that the flexibility, rubber elasticity, and low temperature characteristics of the acrylic block copolymer (A) are not deteriorated. When the cohesive force and glass transition temperature Tg _b of the acid anhydride group and / or the acrylic polymer block by the introduction of a carboxyl group (b) is increased, there is a tendency that flexibility, rubber elasticity, low temperature characteristics deteriorate. Specifically, the glass transition temperature Tg _b of the acrylic polymer block (b) after introducing the acid anhydride group and / or carboxyl group is preferably 25 ° C. or less, more preferably 0 ° C. Hereinafter, it is more preferably set to −20 ° C. or lower.

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 above Fox formula.

The relationship between the glass transition temperature of the methacrylic polymer block (a) and the acrylic polymer block (b) is that the glass transition temperature of the methacrylic polymer block (a) is Tg _a , and the acrylic polymer block (b) the glass transition temperature as Tg _b, it is preferable to satisfy the relation of the following equation.
Tg _a > Tg _b

When an acid anhydride group and / or a carboxyl group are also introduced into the methacrylic polymer block (a), it is preferably introduced within a range in which the moldability of the acrylic block copolymer (A) does not deteriorate. Although the case of performing powder slush molding has to be flowing in a non-pressure, the introduction of the acid anhydride group and / or carboxyl groups when the cohesive force and glass transition temperature Tg _a of the methacrylic polymer block (a) is increased The melt viscosity tends to increase and the moldability tends to deteriorate. Therefore, 130 ° C. Glass transition temperature Tg _a of Specifically, acid anhydride group and / or after the introduction of the carboxyl group methacrylic polymer block (a) or less, more preferably 110 ° C. or less, more preferably It introduce | transduces in the range which becomes 100 degrees C or less.

Next, an acid anhydride group and a carboxyl group will be described.

<Acid anhydride group>
An acid anhydride group easily reacts with a hydroxyl group and an amino group. Further, when the composition contains a compound having an active proton, it easily reacts with an epoxy group.

The acid anhydride group may be introduced into the main chain of the acrylic polymer block (b) or may be introduced into the side chain, but it may be introduced into the acrylic polymer block (b). In view of ease, it is preferably introduced into the main chain. The acid anhydride group is obtained by dehydration and condensation of two carboxyl groups. Specifically, the general formula (1):

(Wherein R ¹ is hydrogen or a methyl group, which 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). preferable.
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.

When the monomer having an acid anhydride group does not poison the catalyst under the polymerization conditions, the acid anhydride group is preferably introduced by direct polymerization. When the body deactivates the catalyst during polymerization, a method of introducing an acid anhydride group by functional group conversion is preferred. Although not particularly limited, it is preferable in terms of ease of introduction that it is introduced into the acrylic polymer block (b) in the form of a precursor of an acid anhydride group and then cyclized. :

(In the formula, R ² represents hydrogen or a methyl group. R ³ represents hydrogen, a methyl group, or a phenyl group, and at least two of the three R ³ groups in the formula consist of a methyl group and a phenyl group. And these may be the same or different from each other.) An acrylic block copolymer comprising at least one unit represented by the following formula: It is more preferable to introduce a desired acid anhydride group by cyclization.

The introduction of the unit represented by the general formula (2) into the acrylic polymer block (b) is carried out by copolymerizing an acrylic ester or methacrylic ester monomer derived from the general formula (2). Can do. Examples of the monomer include t-butyl (meth) acrylate, isopropyl (meth) acrylate, α, α-dimethylbenzyl (meth) acrylate, α-methylbenzyl (meth) acrylate, and the like. It is not limited to these. Among these, (meth) acrylic acid-t-butyl is preferable from the viewpoints of availability, ease of polymerization, ease of acid anhydride group formation, and the like.

The step of forming an acid anhydride group from the precursor by cyclization is preferably performed by heating an acrylic block copolymer having a precursor of an acid anhydride group at a high temperature at 180 to 300 ° C. It is preferable to carry out by heating. When the heating temperature is lower than 180 ° C., there is a tendency that the generation of acid anhydride groups tends to be insufficient. When the heating temperature is higher than 300 ° C., the acrylic block copolymer itself having a precursor of acid anhydride groups tends to decompose. is there.

<Carboxyl group>
Carboxyl groups easily react with epoxy groups and amino groups. The carboxyl group may be introduced into the main chain of the acrylic polymer block (b) or may be introduced into the side chain. The carboxyl group is preferably introduced into the main chain from the viewpoint of ease of introduction into the acrylic polymer block (b).

Regarding the method for introducing a carboxyl group, when the monomer having a carboxyl group does not poison the catalyst under the polymerization conditions, it is preferably introduced by direct polymerization. When deactivating the catalyst, a method of introducing a carboxyl group by functional group conversion is preferred.

In the method of introducing a carboxyl group by functional group conversion, it is introduced into the acrylic polymer block (b) in a form in which the carboxyl group is protected with an appropriate protective group, or in the form of a functional group that becomes a precursor of the carboxyl group, Thereafter, a carboxyl group can be generated by a known chemical reaction.

Examples of the method for synthesizing the acrylic polymer block (b) having a carboxyl group include precursors of carboxyl groups such as tert-butyl methacrylate, tert-butyl acrylate, trimethylsilyl methacrylate, trimethylsilyl acrylate, and the like. A method of synthesizing an acrylic polymer block (b) containing a monomer having a functional group to form a carboxyl group and generating a carboxyl group by a known chemical reaction such as hydrolysis or acid decomposition (JP-A-10-298248, JP 2001-234146 A) and general formula (2):

(In the formula, R ² represents hydrogen or a methyl group. R ³ represents hydrogen, a methyl group, or a phenyl group, and at least two of the three R ³ groups in the formula consist of a methyl group and a phenyl group. And these may be the same or different from each other.) An acrylic block copolymer comprising at least one unit represented by the following formula: There is a way to introduce. The unit represented by the general formula (2) has a route through which an ester unit decomposes at a high temperature to generate a carboxyl group, followed by cyclization and an acid anhydride group. 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). Moreover, a carboxyl group can also be introduce | transduced by hydrolyzing an acid anhydride group. The introduction of a carboxyl group by hydrolysis can be hydrolyzed by heating an acrylic block copolymer having a (carboxyl group) precursor in the presence of an acid catalyst. The reaction temperature at that time is preferably heated at 100 to 300 ° C. When the temperature is lower than 100 ° C., the carboxyl group tends to be insufficiently generated. When the temperature is higher than 300 ° C., the acrylic block copolymer itself having a carboxyl group precursor may be decomposed.

<Acrylic block copolymer (A)>
The acrylic block copolymer (A) of the present invention may be a linear block copolymer, a branched (star) block copolymer, or a mixture thereof. The structure of such a block copolymer may be used depending on the required physical properties of the acrylic block copolymer (A). However, from the viewpoint of cost and ease of polymerization, the linear block copolymer is used. Polymers are preferred.

The linear block copolymer may have any structure. When the methacrylic polymer block (a) is expressed as a and the acrylic polymer block (b) is expressed as b in view of the physical properties of the linear block copolymer or the physical properties of the powder, (ab) _n At least one acrylic block selected from the group consisting of a type, b- (ab) _n- type and (ab) _n- a type (n is an integer of 1 or more, for example, an integer of 1 to 3) It preferably consists of a copolymer. Although not particularly limited, among these, from the viewpoint of ease of handling during processing and physical properties of the powder, ab type diblock copolymer, abb type triblock copolymer, or these Is preferred.

As for the molecular weight of the acrylic block copolymer (A) used in the present invention, the number average molecular weight measured by gel permeation chromatography is 30,000 to 200,000. If the number average molecular weight is smaller than 30,000, sufficient mechanical properties as an elastomer may not be exhibited. Conversely, if the number average molecular weight is larger than 200,000, processing properties may be deteriorated. In the case of powder slush molding, it is necessary to flow even under non-pressurization. Therefore, if the molecular weight is large, the melt viscosity tends to increase and the moldability tends to deteriorate.

In view of the above, the molecular weight of the preferred acrylic block copolymer (A) is preferably 35,000 to 150,000 in terms of number average molecular weight measured by gel permeation chromatography, more preferably 40,000 to 100,000.

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) is not particularly limited, but is 1.8 or less. It is preferable that it is 1.5 or less. If Mw / Mn exceeds 1.8, the uniformity of the acrylic block copolymer may deteriorate.

The molecular weight and molecular weight distribution of the acrylic block copolymer (A) are measured using, for example, a Waters GPC system (column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK, mobile phase: chloroform). be able to. The number average molecular weight is a value expressed in terms of polystyrene.

In the present invention, the methacrylic polymer block (a) and the acrylic polymer block (b) constituting the acrylic block copolymer (A) have a block (a) of 15 to 50% by weight, a block (b ) Is used at a composition ratio of 85 to 50% by weight. When the proportion of (a) is less than 15% by weight, the shape tends to be difficult to be retained during molding, and when the proportion of (b) is less than 50% by weight, the elasticity as an elastomer and the meltability during molding tend to decrease. is there. From the viewpoint of maintaining the shape during molding and the elasticity as an elastomer, the preferred range of the composition ratio is 20 to 45% by weight of (a), 80 to 55% by weight of (b), and more preferably (a ) Is 25 to 40% by weight, and (b) is 75 to 60% by weight.

<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 a polymer initiator. Examples of controlled polymerization include living anion polymerization, radical polymerization using a chain transfer agent, and recently developed living radical polymerization. Of these, living radical polymerization is preferable from the viewpoint of controlling the molecular weight and structure of the 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) and nitroxide. Compounds using radical scavengers such as compounds (Macromolecules, 1994, 27, 7228), atom transfer radical polymerization using organic halides as initiators and transition metal complexes as catalysts (Atom Transfer) And 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 preferable from the viewpoint of ease of control.

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

According to these methods, in general, polymerization proceeds in a living manner and the molecular weight distribution is narrow (Mw / M), although the polymerization rate is very high and 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, a monofunctional, difunctional, or polyfunctional compound can be used as the organic halide or sulfonyl halide compound used as an initiator. 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.

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.

Specific examples of the alkyl group having 1 to 20 carbon atoms (including the alicyclic hydrocarbon group) as R ⁴ include, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, Examples thereof include t-butyl group, n-pentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group, isobornyl group and the like. Specific examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a tolyl group, a naphthyl group, and the like. Specific examples of the aralkyl group having 7 to 20 carbon atoms include benzyl group and phenethyl group.

Specific examples of the monovalent organic group having 1 to 20 carbon atoms which is R ⁵ include the same groups as R ⁴ .

Specific examples of the monofunctional compound include, for example, tosyl bromide, methyl 2-bromide propionate, ethyl 2-bromide propionate, butyl 2-bromide propionate, methyl 2-isobutyrate bromide, 2- Examples thereof include ethyl bromide isobutyrate and 2-butyl isobutyrate bromide. Of these, 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 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.

Specific examples of the bifunctional compound include, for example, bis (bromomethyl) benzene, bis (1-bromoethyl) benzene, bis (1-bromoisopropyl) benzene, dimethyl 2,3-dibromosuccinate, and 2,3-dibromosuccinate. Diethyl acetate, dibutyl 2,3-dibromosuccinate, dimethyl 2,4-dibromoglutarate, diethyl 2,4-dibromoglutarate, dibutyl 2,4-dibromoglutarate, dimethyl 2,5-dibromoadipate, 2, Diethyl 5-dibromoadipate, dibutyl 2,5-dibromoadipate, dimethyl 2,6-dibromopimelate, diethyl 2,6-dibromopimelate, dibutyl 2,6-dibromopimelate, dimethyl 2,7-dibromosuberate, 2, , 7-dibromosuberic acid diethyl, 2,7-dibromosuberine Dibutyl, and the like. Of these, bis (bromomethyl) benzene, diethyl 2,5-dibromoadipate, and diethyl 2,6-dibromopimelate are preferred 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 trisubstituted benzene ring (the position of the three bonds may be any combination in the 1st to 6th positions), and X is the same as above.

Specific examples of the polyfunctional compound include 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.

In the organic halide or sulfonyl halide compound that can be used as an initiator, the carbon to which the halogen group (halogen atom) is bonded is bonded to the carbonyl group or the phenyl group, and the carbon-halogen bond is activated. Polymerization starts. The amount of the initiator to be used may be determined from the molar ratio with the monomer in accordance with the required molecular weight of the acrylic block copolymer. That is, the molecular weight of the acrylic block copolymer can be controlled by the number of monomers used per molecule of the initiator.

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 and its derivatives (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 tetramethyldiethylenetriamine (TMEDA), pentamethyldiethylenetriamine, hexamethyl (2-aminoethyl) amine, etc. may be added as a ligand. .

A tristriphenylphosphine complex of divalent ruthenium chloride (RuCl ₂ (PPh ₃ ) ₃ ) is also preferable as a catalyst. When a ruthenium compound is used as a catalyst, aluminum alkoxides may be added as an activator. Furthermore, a divalent iron bistriphenylphosphine complex (FeCl ₂ (PPh ₃ ) ₂ ), a divalent nickel bistriphenylphosphine complex (NiCl ₂ (PPh ₃ ) ₂ ), and a divalent nickel bistributylphosphine A complex (NiBr ₂ (PBu ₃ ) ₂ ) is also preferable as a catalyst.

The kind of the catalyst, ligand and activator to be used is not particularly limited, and may be appropriately determined from the relationship between the initiator, monomer and solvent to be used and the required reaction rate. For example, in the polymerization of acrylic monomers such as acrylic acid esters, it is preferable from the viewpoint of polymerization control that the growth terminal of the polymer chain has a carbon-bromine bond, so that the initiator used is an organic bromide or It is a sulfonyl bromide compound, the solvent is preferably acetonitrile, copper bromide, preferably a metal complex catalyst centered on copper contained in cuprous bromide, and a ligand such as pentamethyldiethylenetriamine Is preferably used. For polymerization of methacrylic monomers such as methacrylic acid esters, it is preferable from the viewpoint of polymerization control that the growth terminal of the polymer chain has a carbon-chlorine bond. Or a sulfonyl chloride compound, the solvent is preferably a mixed solvent with acetonitrile and, if necessary, toluene, etc., using a metal complex catalyst having copper as the central metal, preferably copper contained in cuprous chloride It is preferable to use a ligand such as pentamethyldiethylenetriamine.

The amount of catalyst and ligand to be 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 polymer with a high molecular weight, the initiator / monomer ratio must be smaller than when trying to obtain a polymer with a low molecular weight. Further, 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.

Examples of the hydrocarbon solvent include benzene and toluene. Examples of ether solvents include diethyl ether and tetrahydrofuran. Examples of the halogenated hydrocarbon solvent include methylene chloride and chloroform. Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the alcohol solvent include methanol, ethanol, propanol, isopropanol, n-butanol, t-butanol and the like. Examples of nitrile solvents include acetonitrile, propionitrile, benzonitrile and the like. Examples of ester solvents include ethyl acetate and butyl acetate. Examples of the carbonate solvent include ethylene carbonate and propylene carbonate.

The solvent mentioned above can be used individually or in combination of 2 or more types.

When a solvent is used, the amount used may be appropriately determined from the relationship between the viscosity of the entire system and the required stirring efficiency. In addition, in the case of bulk polymerization and polymerization performed in various solvents, even when the polymerization is stopped halfway, the monomer conversion rate at the point of stopping the reaction is the relationship between the viscosity of the entire system and the required stirring efficiency. It may be determined as appropriate.

The atom transfer radical polymerization can be carried out in the range of 20 ° C to 200 ° C, preferably in the range of 50 to 150 ° C.

In order to produce an acrylic block copolymer by atom transfer radical polymerization, a method of sequentially adding monomers, a method of polymerizing the next block using a polymer synthesized in advance as a polymer initiator, and polymerizing separately Examples thereof include a method of bonding a polymer by reaction. Any of these methods may be used, and they may be properly used according to the purpose. From the viewpoint of simplicity of the production process, a method by sequential addition of monomers is preferred.

The reaction liquid obtained by the polymerization contains a mixture of a polymer and a metal complex, and an organic acid containing a carboxyl group or a sulfonyl group is added to form a metal complex and a metal salt. The solid content is removed by filtration, etc., and subsequently impurities such as basic activated alumina, basic adsorbent, solid inorganic acid, anion exchange resin, and acid remaining in the solution by cellulose anion exchanger adsorption treatment are removed. By removing, an acrylic block copolymer solution can be obtained.

The polymer solution thus obtained is subsequently subjected to an evaporation operation to remove the polymerization solvent and unreacted monomers. Thereby, an acrylic block copolymer can be isolated. As the evaporation method, a thin film evaporation method, a flash evaporation method, a horizontal evaporation method provided with an extrusion screw, or the like can be used. Since the acrylic block copolymer has adhesiveness, efficient evaporation is possible by combining the horizontal evaporation method with an extrusion screw alone or another evaporation method among the above evaporation methods.

<Acrylic polymer (B)>
The acrylic polymer (B) is a polymer containing at least 1.1 or more reactive functional groups (r) on average in one molecule. The acrylic polymer (B) having such a structure improves the molding fluidity as a plasticizer at the time of molding the powder, and at the same time, acid anhydride groups and carboxyls in the acrylic block copolymer (A) at the time of molding. The acrylic block copolymer (A) can be made to have a high molecular weight or be crosslinked by reacting with a reactive functional group (r). In addition, the number of reactive functional groups (r) here represents the average number of reactive functional groups (r) possessed per molecule of the acrylic polymer (B).

The reactive functional group (r) in the acrylic polymer (B) is 1.1 or more, preferably 1.2 or more, more preferably 1.5 or more in the acrylic polymer (B). Particularly preferably, 2.0 or more are contained. The number is the reactivity of the reactive functional group (r), the site and mode of the reactive functional group (r), the acid anhydride group and / or the carboxyl group in the acrylic block copolymer (A). It is changed according to the number, part and style of the contained. When the functional group (r) 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 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 the acrylic 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. For example, the above-mentioned methacrylic acid ester, aromatic alkenyl compound, cyanide A vinyl compound, a conjugated diene compound, a halogen-containing unsaturated compound, an unsaturated carboxylic acid compound, an unsaturated dicarboxylic acid compound, a vinyl ester compound, a maleimide compound, or the like can be used.

In addition, it is preferable that the ratio of the acrylic 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 molecular weight of the acrylic polymer (B) can be measured using, for example, a GPC system manufactured by Waters (column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK, mobile phase: chloroform). The weight average molecular weight is a value expressed in terms of polystyrene.

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 powder 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, the polymerization may be performed 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 can be 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 (r)>
Examples of the reactive functional group (r) 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 (r) into the acrylic polymer (B) is, for example, a vinyl monomer having a reactive functional group (r) 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 (r) 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 used suitably. These are all acrylic polymers such as acrylic and acrylate / styrene, and contain an average of 1.1 or more epoxy groups in one molecule.

<Thermoplastic elastomer composition (X)>
The thermoplastic elastomer composition (X) comprises an acrylic block copolymer (A) having an acid anhydride group and / or a carboxyl group, and an average of at least 1.1 reactive functional groups (r) per molecule. A thermoplastic elastomer composition comprising a compound (B) containing

Although the ratio of the blend amount of the acrylic block copolymer (A) and the acrylic polymer (B) contained in the thermoplastic elastomer composition (X) is not particularly limited, the blend amount of 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.

While the thermoplastic elastomer composition (X) has a low melt viscosity during molding and excellent moldability, the acrylic anhydride copolymer and / or carboxyl group reacts with the reactive functional group (r) during molding to produce an acrylic block copolymer. The combined body (A) is preferably polymerized or crosslinked, and more preferably crosslinked at the time of 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 thermoplastic elastomer composition (X) as necessary in order to promote the reaction during molding. For example, when the reactive functional group (r) 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. When the functional functional group (r) is a hydroxyl group or a carboxyl group, a known esterification catalyst or transesterification catalyst such as divalent tin compounds and titanate esters can be used.

In addition to the above acrylic block copolymer (A) and acrylic polymer (B), the thermoplastic elastomer composition (X) may contain stabilizers, lubricants, flame retardants, pigments, and fillers as necessary. An agent, a reinforcing agent, a tackifier, and a plasticizer 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 resin, phenol resin, terpene resin, high styrene resin, petroleum hydrocarbon (eg dicyclopentadiene resin, aliphatic cyclic hydrocarbon resin, unsaturated carbonization) 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.

<Dispersion (Y)>
In the present invention, a polymer spherical powder is obtained from a dispersion (Y) containing a solvent (C), water (D) and a dispersant (E) in addition to the thermoplastic elastomer composition (X). The method for forming the dispersion is not particularly limited, and is generally performed by physically stirring a mixture containing the above components.

<Solvent (C)>
The solvent used in the present invention is not particularly limited, and is appropriately selected so that the polymer to be used is dissolved. The boiling point of the solvent is preferably 25 ° C. or higher, more preferably 30 ° C. or higher at normal pressure (1 atm) in consideration of handling at room temperature. In addition, since the solvent is finally evaporated, the boiling point of the solvent is preferably 130 ° C. or less at normal pressure (1 atm), more preferably 120 ° C. or less, and particularly preferably 100 ° C. or less. .

Specific examples of the solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane and cyclopentane, aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene, methyl ethyl ether, diethyl ether and Examples include ethers such as tetrahydrofuran, esters such as ethyl acetate, and halogenated hydrocarbons such as dichloromethane and chloroform.

The solvent is used in an amount of 0.5 to 10 times by weight with respect to the thermoplastic elastomer composition. The amount of the solvent used is appropriately selected in consideration of the concentration, viscosity, etc. of the polymer solution, but is preferably 1 to 9 times the weight, and more preferably 2 to 8 times the weight. If the amount of the solvent is too large, the yield is reduced and it is not efficient. On the other hand, if the amount of the solvent is too small, the viscosity of the entire solution becomes too high, and the polymer may not be sufficiently dispersed by stirring.

<Water (D)>
In the present invention, water (D) 0.5 to 5 times the weight of the thermoplastic elastomer composition (X) is used. The amount of water to be used can be appropriately determined in consideration of the desired polymer particle size and the like. The amount of water is preferably 0.8 to 4 times the weight of the thermoplastic elastomer composition (X), particularly preferably 1 to 3 times the weight. If the weight is less than 0.5 times, the particles may agglomerate and the particle size may become too large. If the weight is more than 5 times, the yield per reactor will be small, and a large amount of dispersant will be required. May not be preferable.

The water to be used is not particularly limited, and any type of water such as soft water, hard water, tap water, ion exchange water, pure water, and distilled water may be used. Ion exchange water, pure water and distilled water are preferred from the viewpoint of preventing impurities from being mixed.

<Dispersant (E)>
In the present invention, at least one dispersant selected from the group consisting of cellulose esters and calcium carbonate is used. The cellulose ester is not particularly limited, and examples thereof include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose and the like. Examples of calcium carbonate include light calcium carbonate, heavy calcium carbonate, and colloidal calcium carbonate. These may be used alone or in combination of two or more.

When cellulose ester is used, it is used at a ratio of 0.1 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic elastomer composition (X). If the amount is less than 0.1 parts by weight, the polymer may not be sufficiently dispersed and particles may be difficult to form. Even if added more than 5 parts by weight, the dispersion characteristics do not change particularly, which is economically undesirable. Moreover, it may adversely affect physical properties such as transparency and moldability of the polymer. Preferably, it is used in a proportion of 0.2 to 2 parts by weight with respect to 100 parts by weight of the thermoplastic elastomer composition (X).

Moreover, when using calcium carbonate, it is used in the ratio of 5-50 weight part with respect to 100 weight part of said thermoplastic elastomer compositions (X). If the amount is less than 5 parts by weight, the polymer may not be sufficiently dispersed and particles may be difficult to form. Even if the amount added is more than 50 parts by weight, the dispersion characteristics are not particularly changed, which is economically undesirable. Even if an amount of calcium carbonate is added, it may be dispersed on the water side without being contained in the resin and flow into the wastewater, causing loss, or adhering to the spherical surface, which may adversely affect physical properties such as moldability There is. Preferably, it is used in a proportion of 10 to 35 parts by weight with respect to 100 parts by weight of the thermoplastic elastomer composition (X).

Furthermore, when using together a cellulose ester and a calcium carbonate, what is necessary is just to use within the range of 0.1-2 weight part of cellulose esters and 5-50 weight part of calcium carbonate with respect to 100 weight part of said thermoplastic elastomer compositions (X). .

<Inorganic particles (F2)>
If necessary, the dispersion (Y) may contain inorganic particles (F2) having a particle size of 0.1 to 30 μm. Such inorganic particles (F2) are not particularly limited, but include asbestos, glass fiber, mica, graphite, diatomaceous earth, white clay, silica (fumed silica, precipitated silica, crystalline silica, fused silica, dolomite, anhydrous Reinforcing fillers such as silicic acid, hydrous silicic acid, etc .; magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, ferric oxide, red pepper, aluminum fine powder, flint powder, zinc oxide, Examples thereof include fillers such as activated zinc white, zinc dust, zinc carbonate and shirasu balloon; glass fibers and glass filaments. These can be used alone or in combination of two or more.

Among these inorganic particles, titanium oxide, silica, and talc are preferable from the viewpoint of improving mechanical properties, reinforcing effect, cost, and the like.

In the case of silica, silica whose surface is previously hydrophobically treated with an organosilicon compound such as organosilane, organosilazane, or diorganopolysiloxane may be used.

The content of the inorganic particles (F2) is preferably 0.5 to 20 parts by weight with respect to 100 parts by weight of the thermoplastic elastomer composition (X). When the addition amount is small, the reinforcing effect of the obtained molded product may not be sufficient, and when the addition amount is too large, the moldability of the resulting powder tends to be lowered. The addition amount is more preferably 1 to 15 parts by weight, particularly preferably 3 to 12 parts by weight, based on 100 parts by weight of the thermoplastic elastomer composition (X).

The inorganic particles (F2) have a particle size of 0.1 to 30 μm. If the particles are smaller than 0.1 μm, the resulting molded article may not have sufficient reinforcing effect. If larger than 30 μm, the spherical particles may not be obtained as a result of the inorganic particles protruding from the powder surface. . Preferably it is 0.5-25 micrometers, Most preferably, it is 1-20 micrometers.

<Polymer spherical powder>
In the present invention, (1) a thermoplastic elastomer composition (X) comprising the acrylic block copolymer (A) and an acrylic polymer (B), and (2) the thermoplastic elastomer composition (X). 0.5 to 10 times the weight of solvent (C), (3) 0.5 to 5 times the weight of water (D) of the thermoplastic elastomer composition (X), and (4) the thermoplastic elastomer composition ( X) At least one dispersant (E) selected from the group consisting of 0.1 to 2 parts by weight of a water-soluble cellulose ester and 5 to 50 parts by weight of calcium carbonate with respect to 100 parts by weight, and as required The inorganic particles (F2) are mixed to obtain a dispersion (Y), and then the solvent (C) and water (D) are removed from the dispersion to obtain a polymer spherical powder.

The polymer spherical powder can be obtained by heating a polymer dispersion dissolved in a solvent, an aqueous dispersion containing water and a dispersant while stirring. Although it does not specifically limit as an apparatus used for stirring, For example, it can carry out in the reaction tank provided with the jacket and the stirrer. The shape of the stirring blade provided in the stirrer is not particularly limited, and any blade such as a screw blade, a propeller blade, an anchor blade, a paddle blade, an inclined paddle blade, a turbine blade, and a large lattice blade can be used. In these, liquid-liquid dispersion operation and solvent removal operation can be performed using the same stirring tank, and after the liquid-liquid dispersion operation is performed in advance to form a dispersion, the solvent removal is continuously performed for a plurality of stirring operations. It can also be performed using a tank.

The stirring time in this case is not particularly limited, and is appropriately determined according to the dispersibility of the polymer so that the polymer is sufficiently dispersed. The stirring time is generally 1 minute to 5 hours, preferably 5 minutes to 3 hours, and more preferably 10 minutes to 2 hours.

Although the liquid temperature at the time of a heating is not specifically limited, It is preferable that it is more than the azeotropic point of a solvent. However, even below the azeotropic point of the solvent, the solvent can be easily removed by reducing the pressure inside the container. Specifically, it is preferably 70 ° C. or higher and lower than 160 ° C., more preferably 80 ° C. or higher and lower than 150 ° C. If it is lower than 70 ° C., the amount of the residual solvent of the spherical particles is increased, and this is not preferable in that the safety at the time of drying, the solvent recovery rate and the like are lowered. On the other hand, when the temperature is 160 ° C. or higher, the spherical particles of the polymer are softened, so that aggregation or the like may occur and the particles may not be dispersed in a single spherical shape.

In addition to the above heating, steam can be blown into the aqueous dispersion and the solvent removed by steam stripping.

After obtaining the aqueous dispersion containing the polymer spherical powder, the polymer spherical powder can be separated by subjecting the aqueous dispersion to filtration, centrifugation, sedimentation, or the like, if necessary. Furthermore, if necessary, it can be made into a polymer spherical powder by drying using a conductive heat transfer dryer such as a grooved agitation dryer or a hot air heat receiving dryer such as a fluid dryer.

The polymer spherical powder that can be obtained in this way is 90% or more of the total number of powder particles, the aspect ratio expressed as the ratio of the minor axis to the major axis of the particles is 1-2, and Those having an average particle diameter of 1 μm or more and less than 1000 μm are preferred.

The closer the aspect ratio of the polymer spherical powder is to 1, the closer it is to a true sphere, indicating that the fluidity of the particles is high. In the polymer spherical powder in the present invention, the aspect ratio of 90% or more of the total number of powder particles is more preferably 1 to 1.8, and particularly preferably 1 to 1.5.

In the present invention, the aspect ratio of the particles is orthogonal to the line connecting the longest diameter and the longest diameter of the particles by taking a photograph with a magnification of 100 to 200 times using a magnifying glass (a KEYENCE microscope). The longest part is measured as the minor axis. The major axis / minor axis is evaluated as the aspect ratio. Each aspect ratio is evaluated for about 300 particles. The ratio of particles having an aspect ratio of 1 to 2 to the total number of powder particles is
[(Number of particles having an aspect ratio of 1 to 2) / (total number of evaluated particles)] × 100 (%)
Can be calculated as

The average particle diameter of the polymer spherical powder is preferably 1 μm or more and less than 1000 μm. When the particle diameter is larger than 1000 μm, molding using a mold having a fine structure is not preferable because molding abnormalities are likely to occur. On the other hand, when the thickness is smaller than 1 μm, static electricity or the like is likely to be generated, and the fluidity may be deteriorated. Moreover, the said particle diameter can be adjusted by adjusting the quantity of a dispersing agent, the ratio of a polymer solution and water, etc. according to the required particle diameter. In the present invention, particles having a smaller particle diameter can be obtained as the amount of the dispersant is increased and as the ratio of polymer solution / water (v / v) is decreased.

In the present invention, the average particle size is a value obtained by sieving the dry spherical powder with a standard sieve and individually weighing the fractions belonging to the respective particle size ranges 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)).

<Inorganic particles (F1)>
The powder for molding an automobile interior skin according to the present invention may be the polymer spherical powder itself obtained as described above, but may also contain inorganic particles (F1). Although it does not specifically limit as inorganic particle (F1), In addition to what was illustrated as an example of inorganic particle (F2), calcium carbonate, such as light calcium carbonate, heavy calcium carbonate, and colloidal calcium carbonate, etc. can be used. Of these, titanium oxide, calcium carbonate, silica, and talc are preferable from the viewpoint of improving mechanical properties, reinforcing effect, cost, and the like.

In this invention, the said inorganic particle (F1) is 0-20 with respect to 100 weight part of polymer spherical powder obtained by removing the said solvent (C) and water (D) from a dispersion (Y). Part by weight can be added. When the addition amount is small, the reinforcing effect of the obtained molded product may not be sufficient, and when the addition amount is too large, the moldability of the resulting powder tends to be lowered. Therefore, it is preferable to add 1 to 18 parts by weight, and it is more preferable to add 3 to 15 parts by weight.

Furthermore, carbon black, activated carbon, etc. can also be mix | blended as needed.

<About car interior skin>
The present invention also relates to an automobile interior skin formed by powder slush molding of the above-mentioned automotive interior skin molding powder. Although the method of powder slush molding is not particularly limited, an example of the procedure is as follows. A mold release agent (silicone mold release agent or the like) is applied to the mold at a temperature of 60 ° C. or less by spraying or brushing, and the mold is heated by hot sand heating, oil heating or the like. Next, the powder for molding the skin for automobile interior is introduced into the mold and held for 10 to 45 seconds to weld the powder, then the excess unwelded powder is removed, and further 60 to 300 seconds, preferably After completing the welding of the material by holding for 70 to 120 seconds, the molded body (usually 0.2 to 2 mm thick sheet) is obtained by cooling and demolding the mold by water cooling or the like.

EXAMPLES Next, although this invention is demonstrated further in detail based on an Example, this invention is not limited only to these Examples.
In the examples, the following abbreviations were used.
BA: n-butyl acrylate MEA: 2-methoxyethyl acrylate MMA: methyl methacrylate TBA: t-butyl acrylate EA: ethyl acrylate

The molecular weight and molecular weight distribution of the polymer shown in this example were measured using a Waters GPC system (column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK, mobile phase: chloroform). The number average molecular weight is expressed in terms of polystyrene.

Each particle diameter and average particle diameter of the polymer spherical powder were measured by using an electromagnetic sieve shaker (manufactured by Lecce Co., Ltd., AS200BASIC (60 Hz)). Among these, the average particle diameter was specifically measured as follows. First, using standard sieves having openings of 4000 μm, 2000 μm, 1000 μm, 710 μm, 500 μm, 300 μm, 212 μm, 100 μm, and 53 μm, respectively, and using an electromagnetic sieve shaker (manufactured by Lecce, AS200BASIC (60 Hz)) for 10 minutes Vibrating sieving was performed, and the particles remaining on each sieve were collected and weighed. At this time, particles of 4000 μm or more were excluded. The particle weight on a sieve with an opening of 2000 μm is converted as W3000, average particle diameter (4000 + 2000) / 2 = 3000 μm, and similarly, the weight on the 1000 μm sieve is W1500, the particle diameter is 1500 μm, the weight on the 710 μm sieve is W855, and the particle diameter is 855 μm. The weight on the 500 μm sieve is W605, the particle diameter is 605 μm, the weight on the 300 μm sieve is W400, the particle diameter is 400 μm, the weight on the 212 μm sieve is W256, the particle diameter is 256 μm, the weight on the 100 μm sieve is W156, the particle diameter is 156 μm, and the weight on the 53 μm sieve A particle weight of 76.5 μm at W76.5 and a particle weight of 53 μm or less was handled as an average particle size of 26.5 μm at W26.5. The total weight of each was taken as WT, and the weight average diameter Dave (μm) was calculated by the following equation.
Dave =
(3000 × W3000 + 1500 × W1500 + 855 × W855 + 605 × W605 + 400 × W400 + 256 × W256 + 156 × W156 + 76.5 × W76.5 + 26.5 × W26.5) / WT

The aspect ratio of the polymer spherical powder was determined as follows. Take a photograph at a magnification of 100 to 200 times using a magnifying glass (Keyence microscope), the longest part of the particle is the major axis, the longest part is perpendicular to the line connecting the major axis and the longest part is the minor axis The major axis / minor axis was measured as an aspect ratio. Each aspect ratio was evaluated for about 300 particles. The ratio of particles having an aspect ratio of 1 to 2 to the total number of powder particles is
[(Number of particles having an aspect ratio of 1 to 2) / (total number of evaluated particles)] × 100 (%)
Calculated as

The micrograph of the powder for molding automobile interior skin was observed and photographed using an S-800 microscope manufactured by Hitachi.

<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 (a) constituting the acrylic block copolymer (A) is a ratio of loss elastic modulus / storage elastic modulus at 50 ° C. to 130 ° C. (tan δ) in dynamic viscoelasticity measurement. Was measured as the temperature showing the maximum value of.
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 apparatus DVA-200 ( Using IT Measurement Control Co., Ltd.), the measurement frequency was 0.5 Hz.

<Abrasion resistance evaluation test>
Samples having a width of 3 cm and a length of 10 cm were cut out from the sheets obtained by powder slush molding in Examples and Comparative Examples, and subjected to an abrasion test using 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 and visually observed, and the wear resistance was evaluated according to the following criteria.
Things that do not clearly show scratches from the front; ○
Slightly scratched when seen from the front;
Those with obvious scratches such as whitening and erosion; ×

<Scratch resistance>
A sample having a width of 10 cm and a length of 10 cm was cut out from a sheet obtained by powder slush molding in Examples and Comparative Examples, and attached to a mount to obtain a measurement sample. A scratch test was conducted under the following conditions.
Equipment used: Tabers Clutch Tester (Toyo Seiki 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, and the sample was visually observed. The scratch resistance was evaluated according to the following criteria.
Things that do not clearly show scratches from the front; ○
Slightly scratched when seen from the front;
Those with 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 on the 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 sheets prepared in the examples and comparative examples were left 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>
A urethane foam mold (140 mm long x 200 mm wide x 10 mm high lid, made of SUS304) is obtained by preliminarily setting the skin material obtained by slush molding according to the embodiment using the powder for car interior skin molding. ) With the embossed surface of the skin material facing down. 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) at room temperature for 10 seconds with a hand mixer. 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 skin material and urethane;
Breaking at the interface between the skin material and urethane; ×

<Melability>
The textured surface and the molded back surface of the resulting molded sheet were observed 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 side 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

<Repose angle>
The angle of repose uses a Hosokawa Micron powder tester and slowly drops the particles from a height of 11 cm above the disk floated from the desk by the method shown in FIG. ) Was evaluated. The angle of repose is an index that indicates the ease of collapse of powder particles and the ease of flow of powder particles in a static state. The smaller the angle of repose, the better the powder flowability of the particles. Particles easily reach every corner of the mold.

<Apparent specific gravity>
The apparent specific gravity was measured using a Hosokawa Micron powder tester by the method shown in FIG. The particles were calculated by filling a container of known volume and dividing the weight of the particle by the volume of the container. The apparent specific gravity is an index indicating the magnitude of the filling rate of the resin. When a resin powder having a small apparent specific gravity is used, a molded body having many voids is easily formed at the time of molding.

<ICI flow time>
In the ICI flow, a funnel-shaped metallic container shown in FIG. 4 is filled with a certain weight of resin powder, and the time from when the bottom lid is opened until the powder flows out is measured. The ICI flow is an index representing the ease of flow of the powder particles in the dynamic state of the powder particles. A small ICI flow time indicates that the powder flowability of the particles is good, Particles tend to spread quickly to every corner of the mold.

<Moldability>
Formability is determined by performing powder slush molding with a box-shaped embossed die, and comprehensively judging the embossed pattern, the bottom surface, the presence or absence of pinholes on the boundary surface, and the unevenness of the molding back surface. Specifically, as described in Example 1, using a container with a lid as shown in FIG. 5, the container is heated to 260 ° C., turned upside down, filled with resin powder, inverted, and turned to the embossed surface. Drop the resin and mold the sheet.

(Production Example 1)
<Synthesis of Acrylic Block Copolymer (A) Precursor>
The following operation was performed in order 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 sampling. 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 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 ). It was 101 degreeC when the glass transition temperature of the methacrylic polymer block (a) obtained by this manufacture example 1 was computed according to the said Fox formula.

(Production Example 2)
To about 450 kg of the filtered block copolymer solution obtained in Production Example 1, 675 g of Irganox 1010 (manufactured by Ciba Specialty Chemicals) was added and dissolved. The reactor was purged with nitrogen, stirred at an internal temperature of 150 ° C. for 2 hours, and then cooled to 60 ° C. Kyoward 500SH 1310 g was added, the inside of the reactor was purged with nitrogen, and the mixture was stirred at 30 ° C. for 2 hours. 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.

(Production Example 3)
To about 450 kg of the filtered block copolymer solution obtained in Production Example 1, 1310 g of Kyoward 500SH was added, 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.

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, carbon black (Asahi Carbon Co., Ltd., Asahi # 15) 1 .4 parts by weight, and a lubricant (manufactured by Nippon Oil & Fats Co., Ltd., beef tallow extremely hardened oil) at a ratio of 0.14 parts by weight was added, stirred and mixed, and then charged into a 50 L pressure-resistant stirrer.

Subsequently, 8 kg of pure water was charged, 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, and 750 g was added as a 2% aqueous solution. The temperature was raised by blowing steam from the bottom of the stirring tank while stirring at 250 rpm using a two-stage four-paddle paddle. The solvent gas evaporated by the temperature rise was introduced into the condenser, and the solvent was sequentially recovered. After reaching 100 ° C. for 10 minutes, 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 recovered. 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 recover resin powder. The amount of residual solvent per dry powder weight in the powder resin was 5,000 ppm. 3 parts by weight of silica powder (manufactured by Tatsumori Co., Ltd., microcrystalline soft silica A-10) was added to 100 parts by weight of the recovered resin powder. After mixing, the particles were vacuum-dried overnight to obtain dry particles. The weight of the obtained dry powder particles was measured, and silica powder as an inorganic particle (F1) at normal temperature (about 25 ° C.) (manufactured by Tatsumori Co., Ltd., microcrystalline soft silica A-10, average particle size 2) .6 μm) was added to the powder using a blender so that the weight of the silica powder relative to the weight of the dry powder particles was 6 parts in total to obtain a powder for molding an automobile interior skin.

Slush molding was performed using the obtained powder for molding an automobile interior skin. Conditions are as follows: 1 kg powder for car interior skin molding is put into a 1 kg powder box, a flat plate with grain heated to 260 ° C. is set in a box containing powder for car interior skin molding, and then cooled to 250 ° C. did. When the embossed flat plate reached 250 ° C., it was inverted and allowed to stand for 6 seconds, and then inverted again. Thereafter, excess unwelded powder was shaken off, and when 60 seconds had passed, the mold was cooled with cooling water for 40 seconds. Thereafter, the sheet was peeled off from the mold to obtain a molded sheet. Table 1 shows the results of evaluating the obtained molded sheet.

4.5 kg of toluene was added to 1.5 kg of the acrylic block copolymer (A) precursor pellets shown in Production Example 3 and mixed by stirring to obtain a polymer solution having a solid content concentration of 25%. In 6 kg of this polymer solution, 100 parts by weight of the acrylic block copolymer (A), ARUFON XG4010 (manufactured by Toagosei Co., Ltd., acrylic resin as an acrylic polymer (B), 1 epoxy group 1.1 parts or more in the molecule (contains 4 approximate values (from catalog)) 10 parts by weight, lubricant (manufactured by Nippon Oil & Fats Co., Ltd., beef fat extremely hardened oil) 0.14 parts by weight, and carbonic acid as a dispersant After adding, stirring and mixing at a ratio of 43 parts by weight of calcium (trade name Brilliant-1500, manufactured by Shiroishi Kogyo Co., Ltd.), the mixture was put into a 50 L pressure-resistant stirrer.

Subsequently, 8 kg of pure water was charged, and the temperature was increased by blowing steam from the lower part of the stirring tank while stirring at 250 rpm using a two-stage four-paddle paddle on the stirring blade, and the solvent was evaporated in the same manner as in Example 1. The resin slurry was recovered. In the obtained powder, particles having a particle diameter of 0.05 to 0.30 mm accounted for 90% of the total powder by weight ratio, and the average particle diameter was 185 μm. The particles having an aspect ratio in the range of 1 to 2 were spherical particles that accounted for 93% of the total number of particles. Resin powder is recovered from the recovered resin slurry in the same manner as in Example 1. The silica powder is added to the powder using a blender so that the silica powder weight with respect to the dry powder particle weight is 6 parts in total. A powder for interior skin molding was obtained. Using the obtained powder for molding an automobile interior skin, slush molding was performed in the same manner as in Example 1. Table 1 shows the results of evaluating the obtained molded sheet.

(Comparative Example 1)
For 100 parts by weight of the acrylic block copolymer (A) precursor obtained in Production Example 3, 1 part by weight of hydrotalcite DHT-4A-2 (Kyowa Chemical Industry Co., Ltd.) is used as an acid trapping agent. Using a twin screw extruder with a vent (44 mm, L / D = 42.25) (manufactured by Nippon Steel Works), the rotation speed of 150 rpm, the cylinder temperature of the hopper installation part is 100 ° C., All were extruded and kneaded at 260 ° C. at a temperature setting to obtain the target acid anhydride group and carboxyl group-containing acrylic block copolymer. During extrusion, the vent 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 methacrylic polymer block (a) of the resulting acrylic block copolymer 1 had a Tg of 101 ° C. For 100 parts by weight (100 kg) of the acrylic block copolymer, ARUFON XG4010 as an acrylic polymer (manufactured by Toagosei Co., Ltd., acrylic resin, 1.1 or more epoxy groups per molecule (approximate) 10 parts by weight (containing 4 values (from the catalog)), 43 parts by weight of calcium carbonate (Bihoku Powder Chemical Co., Ltd., Softon 3200), carbon black (Asahi Carbon Co., Ltd., Asahi # 15) 1.4 Cylinder temperature of 80 parts by weight using a bent twin screw extruder LABOTEX30HSS (manufactured by Nippon Steel Co., Ltd.) at a ratio of 0.14 parts by weight of lubricant (made by Nippon Oil & Fat Co., Ltd., beef fat extremely hardened oil). The strand was discharged as a strand at 100 ° C. and 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 UCM300) to obtain a powder sample. The obtained powder was further classified using a stainless 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 dropped 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 (F1) at room temperature (about 25 ° C.) was added to the obtained powder. Then, it was added to the powder using a blender to obtain a powder for molding an automobile interior skin. In the obtained granular material, particles having a particle size of 0.05 to 0.40 mm accounted for 90% of the total powder by weight, and the average particle size was 195 μm, but the aspect ratio was 1-2. In this range, the shape of the particles was an elongated irregular shape of less than 40% of the total number of particles. Using the obtained powder for molding an automobile interior skin, slush molding was performed in the same manner as in Example 1. Table 1 shows the results of evaluating the obtained molded sheet.

As can be seen from Table 1, the molding powder for automobile interior of the present invention has a good heat resistance at the same time as the meltability at the time of slush molding compared with the conventional powder obtained by pulverization. Excellent balance between meltability and heat resistance. Moreover, although the adhesiveness with a urethane foam and a scratch resistance are also favorable materials, it turns out that the powder of the comparative example 1 is inferior in powder fluidity | liquidity.

FIG. 1 is an enlarged photograph of a powder for molding an automobile interior skin obtained in Example 1 using a microscope, while FIG. 2 is an enlarged photograph of a pulverized product of Comparative Example 1. In any picture, one grid in the picture corresponds to the actual size of 1 mm × 1 mm. In FIG. 1, the powder for molding an automobile interior skin of the present invention is almost spherical, as can be seen from the aspect ratio. On the other hand, as shown in FIG. 2, it can be seen that many of the conventional particles obtained by pulverization are amorphous powders having irregular beard-like protrusions. This photograph shows the reason why the powder fluidity of the powder for molding an automobile interior of the present invention is good.

Further, Table 2 shows the angle of repose, apparent specific gravity, ICI flow time, and moldability of the powder for molding an automobile interior of the present invention obtained in Examples 1 and 2 and the powder of Comparative Example 1. The evaluation results are shown. As can be seen from Table 2, compared to Comparative Example 1, the powder for molding an automobile interior of the present invention obtained in Examples 1 and 2 has a small angle of repose and a short ICI flow. It can be seen that the powder tends to collapse and flow easily. Moreover, since the apparent specific gravity is larger in the example, it can be understood that the gap can be filled with little gap when the mold is filled. These differences are presumed to be due to the shape of the powder as shown in FIGS.

Molding was performed using the powders obtained in Examples 1 and 2 and Comparative Example 1. As a result, when the powder for molding an automobile interior skin of Examples 1 and 2 was used, a good molded body without a pinhole was obtained up to the upper part of the mold, whereas the powder of Comparative Example 1 was used. Some pinholes were observed in the molded body, and particularly the filling of the upper part of the mold was not good, and the end of the upper part of the particle filling phase was fluffy.

By comparing the powders obtained in Examples 1 and 2 and Comparative Example 1 with respect to the powder prepared by the conventional method of once pelletizing and pulverizing as in Comparative Example 1, the polymer as in the present invention is used. Using spherical powder obtained by evaporating the solvent while stirring the solution and water improves the powder fluidity and, as a result, fillability for molding the car interior skin into the mold during molding. Can be seen to improve. This indicates that even a skin material having a complicated shape can be produced with good shape expression. Further, as described above, the obtained sheet is excellent in heat resistance, abrasion resistance, and touch feeling, and is excellent in polyurethane adhesiveness, and is found to be suitable as an automobile interior skin.

The molded body obtained from the powder for molding automobile interior skin according to the present invention has abrasion resistance, scratch resistance, chemical resistance (ethanol resistance), oil resistance, heat resistance, weather resistance, adhesion, and flexibility. Because of its excellent properties, it can be used as an automobile interior skin. The shape can be an arbitrary shape such as a sheet shape, a flat plate shape, or a film shape. Since the powder for molding an automobile interior skin of the present invention has a good powder flowability, it can be satisfactorily filled even in a complex-shaped mold, and is suitably used for molding an automobile interior skin. Is done.

2 is a photograph of a powder for molding an automobile interior skin obtained in Example 1. FIG. One grid in the photograph corresponds to the actual size of 1 mm × 1 mm. 2 is a photograph of powder obtained in Comparative Example 1. One grid in the photograph corresponds to the actual size of 1 mm × 1 mm. It is a figure which shows the measuring method of a repose angle and apparent specific gravity. It is a figure of the funnel-shaped metallic container used for the measurement of ICI flow. It is the figure which showed the metal mold | die used for a moldability evaluation.

Claims (4)

(1) Methacrylic polymer block (a) having a glass transition temperature of 50 to 130 ° C. (a) 15 to 50% by weight, and a group consisting of acrylic acid-n-butyl, ethyl acrylate and acrylic acid-2-methoxyethyl Acid anhydride obtained by polymerizing 50 to 100% by weight of at least one monomer selected from the above, and 50 to 0% by weight of different acrylates and / or vinyl monomers copolymerizable therewith Acrylic polymer block (b) having a group and / or a carboxyl group (b) of 85 to 50% by weight, and having a number average molecular weight of 30,000 to 200,000 measured by gel permeation chromatography A polymer (A);
Acrylic polymer (B) having at least 1.1 or more reactive functional groups (r) on average in one molecule
A thermoplastic elastomer composition (X) comprising:
(2) 0.5 to 10 times the solvent (C) of the thermoplastic elastomer composition (X),
(3) 0.5 to 5 times weight of water (D) of the thermoplastic elastomer composition (X),
(4) At least one dispersant selected from the group consisting of 0.1 to 5 parts by weight of cellulose ester and 5 to 50 parts by weight of calcium carbonate with respect to 100 parts by weight of the thermoplastic elastomer composition (X) ( E)
100 parts by weight of the polymer spherical powder obtained by removing the solvent (C) and water (D) from the dispersion (Y) containing
(5) A skin molding powder for automobile interior, comprising 0 to 20 parts by weight of inorganic particles (F1). The dispersion (Y) contains 0.5 to 20 parts by weight of inorganic particles (F2) having a particle diameter of 0.1 to 30 μm with respect to 100 parts by weight of the thermoplastic elastomer composition (X). The powder for molding an automobile interior skin according to claim 1. The obtained polymer spherical powder has an aspect ratio of 1 to 2 in which 90% or more of the total number of powder particles is expressed as a ratio of the minor axis to the major axis of the particles, and
3. The powder for molding an automobile interior skin according to claim 1, wherein the average particle size is 1 μm or more and less than 1000 μm. An automotive interior skin obtained by powder slush molding the automotive interior skin molding powder according to any one of claims 1 to 3.