JP2018184546A - Thermoplastic elastomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition which has high thermal conductivity and is excellent in both flexibility and heat resistance, and to provide a molded body obtained by the composition.SOLUTION: There are provided a thermoplastic elastomer composition that contains a thermoplastic elastomer formed of a block copolymer having a polymer block (A) containing a structural unit derived from styrenes and a maleimide compound and an acrylic polymer block (B), and a conductivity imparting agent of 1-100 pts.vol. with respect to 100 pts.vol. of the thermoplastic elastomer, where the polymer block (A) is a polymer that has 30 mass% or more and 99 mass% or less of a structural unit derived from a maleimide compound in the total structural unit of the polymer block (A) and a glass transition temperature (Tg) of 150°C or higher; and a molded body obtained by heating and molding the thermoplastic elastomer composition.SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic elastomer composition used for a wide range of industrial materials that require electrical conductivity, such as an antistatic mat, an antistatic grip, an electromagnetic wave suppression sheet, a cable coating, and a touch pen, and the thermoplastic elastomer composition. It is related with the molded object obtained by heat-molding.

Patent Document 1 discloses a resin composition that is flexible and has a volume resistivity of 10 ² to 10 ¹² Ω · cm, which includes a styrene-based thermoplastic elastomer and / or an olefin-based thermoplastic elastomer and a conductive filler. ing.

Japanese Patent Laid-Open No. 10-226742

  However, the resin composition described in Patent Document 1 has a drawback that the heat resistance is not sufficient and the resin composition cannot be used for applications that require high heat resistance such as automobile applications.

  The subject of this invention is providing the thermoplastic elastomer composition which has high electroconductivity, and was excellent in both the softness | flexibility and heat resistance, and the molded object by this composition.

The present invention
[1] A thermoplastic elastomer comprising a polymer block (A) containing a structural unit derived from styrenes and a maleimide compound, and a block copolymer having an acrylic polymer block (B), and 100 volumes of the thermoplastic elastomer A thermoplastic elastomer composition containing 1 to 100 parts by volume of a conductivity-imparting agent with respect to parts, wherein the polymer block (A) is a maleimide compound in all structural units of the polymer block (A). A thermoplastic elastomer composition, which is a polymer having a structural unit derived from 1 to 30% by mass and 99% by mass and having a glass transition temperature (Tg) of 150 ° C. or higher, and [2] the above [1] The present invention relates to a molded article obtained by thermoforming the thermoplastic elastomer composition.

  The thermoplastic elastomer composition of the present invention has an effect of having high conductivity and excellent flexibility and heat resistance.

  The thermoplastic elastomer composition of the present invention (hereinafter also referred to as the composition of the present invention) includes a polymer block (A) containing structural units derived from styrenes and a maleimide compound, and an acrylic polymer block (B). It contains a thermoplastic elastomer made of a block copolymer having a conductivity and a conductivity-imparting agent.

<Polymer block (A)>
As described above, the polymer block (A) has a structural unit derived from styrenes and a maleimide compound.

The styrenes include styrene and its derivatives. Specific compounds include styrene, α-methyl styrene, β-methyl styrene, vinyl toluene, vinyl xylene, vinyl naphthalene, o-methyl styrene, m-methyl styrene, p-methyl styrene, o-ethyl styrene, m- Ethyl styrene, p-ethyl styrene, pn-butyl styrene, p-isobutyl styrene, pt-butyl styrene, o-methoxy styrene, m-methoxy styrene, p-methoxy styrene, o-chloromethyl styrene, p- Examples include chloromethyl styrene, o-chloro styrene, p-chloro styrene, o-hydroxy styrene, m-hydroxy styrene, p-hydroxy styrene, divinyl benzene and the like, and one or more of these may be used. it can. By polymerizing a monomer containing styrenes, a structural unit derived from styrenes can be introduced into the polymer block (A).
Among these, styrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-hydroxystyrene, m-hydroxystyrene, and p-hydroxystyrene are preferable from the viewpoint of polymerizability. Further, α-methylstyrene, β-methylstyrene, and vinylnaphthalene are preferable in that the Tg of the polymer block (A) can be increased and a block polymer having excellent heat resistance can be obtained.

In the polymer block (A), the proportion of the structural units derived from the styrenes is preferably 1% by mass or more and 70% by mass or less in all the structural units of the polymer block (A). More preferably, they are 5 mass% or more and 70 mass% or less, More preferably, they are 10 mass% or more and 70 mass% or less, More preferably, they are 20 mass% or more and 60 mass% or less. Further, for example, it may be 20% by mass or more and 40% by mass or less.
If the structural unit derived from styrene is 1% by mass or more, a block copolymer having excellent moldability can be obtained. On the other hand, if it is 70 mass% or less, since it becomes possible to ensure the required amount of the structural unit derived from the maleimide compound mentioned later, the block copolymer excellent in heat resistance and oil resistance can be obtained.

  The maleimide compound includes maleimide and N-substituted maleimide compounds. Examples of the N-substituted maleimide compound include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, N-tert-butylmaleimide N-alkyl substituted maleimide compounds such as N-pentylmaleimide, N-hexylmaleimide, N-heptylmaleimide, N-octylmaleimide, N-laurylmaleimide, N-stearylmaleimide; N-cyclopentylmaleimide, N-cyclohexylmaleimide, etc. N-cycloalkyl substituted maleimide compounds; N-phenylmaleimide, N- (4-hydroxyphenyl) maleimide, N- (4-acetylphenyl) maleimide, N- (4-methoxyphenyl) maleimide, N- (4- N-aryl-substituted maleimide compounds such as toxiphenyl) maleimide, N- (4-chlorophenyl) maleimide, N- (4-bromophenyl) maleimide, N-benzylmaleimide, etc., and one or two of these The above can be used. By polymerizing a monomer containing a maleimide compound, a structural unit derived from the maleimide compound can be introduced into the polymer block (A).

  Among these, the compound represented by the following general formula (1) is preferable in that the resulting block copolymer has more excellent oil resistance.

Wherein, ^{R 1} represents hydrogen, an alkyl group or PHR ² of 1 to 3 carbon atoms. However, Ph represents a phenyl group, R ² represents hydrogen, hydroxy group, an alkoxy group having 1 to 2 carbon atoms, an acetyl group or a halogen. ]

In the polymer block (A), the proportion of the structural unit derived from the maleimide compound is 30% by mass or more and 99% by mass or less in all the structural units of the polymer block (A). Preferably they are 30 to 95 mass%, More preferably, they are 30 to 90 mass%, More preferably, they are 40 to 80 mass%. For example, it may be 50% by mass or more, and for example, may be 60% by mass or more. Further, for example, it may be 75% by mass or less, and for example, 70% by mass or less. For example, it may be 50% by mass or more and 75% by mass or less, or 60% by mass or more and 70% by mass or less.
When the structural unit derived from the maleimide compound is less than 30% by mass, the resulting block copolymer may not have sufficient heat resistance and oil resistance. On the other hand, if it exceeds 99% by mass, the structural units derived from the styrenes may be insufficient, resulting in insufficient fluidity and moldability.

  At least one of the polymer block (A) and the acrylic polymer block (B) preferably has a crosslinkable functional group. When the polymer block (A) contains a crosslinkable functional group, the compression set This is preferable because a block copolymer having a small value can be easily obtained. The crosslinkable functional group may be introduced by using, for example, styrenes and / or maleimide compounds having a functional group such as a hydroxy group, or by copolymerizing a vinyl compound having a crosslinkable functional group. Can do. As vinyl compounds having a crosslinkable functional group, unsaturated carboxylic acid, unsaturated acid anhydride, hydroxy group-containing vinyl compound, epoxy group-containing vinyl compound, primary or secondary amino group-containing vinyl compound, reactive silicon group-containing Compounds and the like. These compounds may be used alone or in combination of two or more.

  Examples of unsaturated carboxylic acids include (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamic acid, and monoalkyl esters of unsaturated dicarboxylic acids (maleic acid, fumaric acid, itaconic acid). Acid, citraconic acid, maleic anhydride, itaconic anhydride, monoalkyl esters such as citraconic anhydride, etc.). These compounds may be used alone or in combination of two or more.

  Examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride and the like. These compounds may be used alone or in combination of two or more.

  Examples of the hydroxy group-containing vinyl compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth ) 3-hydroxybutyl acrylate, 4-hydroxybutyl (meth) acrylate, and mono (meth) acrylates of polyalkylene glycols such as polyethylene glycol and polypropylene glycol. These compounds may be used alone or in combination of two or more.

  Examples of the epoxy group-containing vinyl compound include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, 3,4-epoxycyclohexylmethyl (meth) acrylate, and the like. These compounds may be used alone or in combination of two or more.

  Examples of the primary or secondary amino group-containing vinyl compound include amino groups such as aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, N-methylaminoethyl (meth) acrylate, and N-ethylaminoethyl (meth) acrylate. Containing (meth) acrylic acid ester; amino group-containing (meth) acrylamide such as aminoethyl (meth) acrylamide, aminopropyl (meth) acrylamide, N-methylaminoethyl (meth) acrylamide, N-ethylaminoethyl (meth) acrylamide, etc. Etc.

  Examples of reactive silicon group-containing compounds include vinyl silanes such as vinyl trimethoxy silane, vinyl triethoxy silane, vinyl methyl dimethoxy silane, and vinyl dimethyl methoxy silane; trimethyoxysilylpropyl (meth) acrylate, trimethyl (meth) acrylate Silyl group-containing (meth) acrylic esters such as ethoxysilylpropyl, methyldimethoxysilylpropyl (meth) acrylate, dimethylmethoxysilylpropyl (meth) acrylate; silyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether; Examples thereof include silyl group-containing vinyl esters such as vinyl methoxysilylundecanoate. These compounds may be used alone or in combination of two or more.

  In addition to the above, an oxazoline group or an isocyanate group can be introduced as a crosslinkable functional group by copolymerizing an oxazoline group-containing monomer or an isocyanate group-containing monomer.

  Furthermore, by copolymerizing a polyfunctional polymerizable monomer having two or more polymerizable unsaturated groups in the molecule, a polymerizable unsaturated group is introduced as a crosslinkable functional group into the polymer block (A). obtain. The polyfunctional polymerizable monomer is a compound having two or more polymerizable functional groups such as a (meth) acryloyl group or an alkenyl group in the molecule, a polyfunctional (meth) acrylate compound, a polyfunctional alkenyl compound, The compound etc. which have both (meth) acryloyl group and an alkenyl group are mentioned. Of these, allyl (meth) acrylate, isopropenyl (meth) acrylate, butenyl (meth) acrylate, pentenyl (meth) acrylate, 2- (2-vinyloxyethoxy) ethyl (meth) acrylate, etc. When a compound having both a (meth) acryloyl group and an alkenyl group in the molecule, there is a difference in the reactivity of the polymerizable unsaturated group, so that the polymer block (A) is effectively polymerizable unsaturated. This is preferable in that a group can be introduced. These compounds may be used alone or in combination of two or more.

  When the polymer block (A) has a crosslinkable functional group, the amount of the crosslinkable functional group introduced is preferably 0.01 mol% or more based on the total structural unit of the polymer block (A), and more Preferably it is 0.1 mol% or more, More preferably, it is 1.0 mol% or more, Most preferably, it is 2.0 mol% or more. When the amount of the crosslinkable functional group introduced is 0.01 mol% or more, it is easy to obtain a block copolymer having a small compression set value. On the other hand, from the viewpoint of controllability of the crosslinking reaction, the upper limit of the amount of the crosslinkable functional group introduced is preferably 60 mol% or less, more preferably 40 mol% or less, still more preferably 20 mol% or less, Preferably it is 10 mol% or less. The amount of the crosslinkable functional group introduced can be in the range of 0.01 mol% to 60 mol%, preferably 0.1 mol% to 40 mol, based on the total structural units of the polymer block (A). % Or less, and more preferably 1.0 mol% or more and 20 mol% or less.

The polymer block (A) may have a structural unit derived from another monomer copolymerizable with the monomer unit in addition to the monomer unit as long as the effects of the present invention are not impaired. . Examples of other monomers include (meth) acrylic acid alkyl ester compounds, (meth) acrylic acid alkoxyalkyl ester compounds, amide group-containing vinyl compounds, and the like. These compounds may be used alone or in combination of two or more.
Among these, an amide group-containing vinyl compound is preferable because a block copolymer having more excellent oil resistance can be obtained.
In the polymer block (A), the proportion of the structural units derived from the other monomers is in the range of 0% by mass to 50% by mass in the total structural units of the polymer block (A). Is preferred. More preferably, they are 5 mass% or more and 45 mass% or less, More preferably, they are 10 mass% or more and 40 mass% or less.

  Specific examples of the (meth) acrylic acid alkyl ester compound include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, and (meth) acrylic acid n. -Butyl, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate (Meth) acrylic acid n-nonyl, (meth) acrylic acid isononyl, (meth) acrylic acid decyl, and (meth) acrylic acid dodecyl (meth) acrylic linear or branched alkyl ester compounds; ) Acrylic acid cyclohexyl, (meth) acrylic acid methyl cyclohexyl, (meth) acrylic (Meta) such as tert-butylcyclohexyl acid, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate ) Aliphatic cyclic ester compounds of acrylic acid.

  Examples of (meth) acrylic acid alkoxyalkyl ester compounds include methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and (meth) acrylic acid n. -Propoxyethyl, n-butoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxypropyl (meth) acrylate, n-propoxypropyl (meth) acrylate, n-butoxypropyl (meth) acrylate, Examples include methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, n-propoxybutyl (meth) acrylate, and n-butoxybutyl (meth) acrylate.

  Examples of the amide group-containing vinyl compound include (meth) acrylamide, tert-butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and N-isopropyl (meth) acrylamide. , N, N-dimethylaminopropyl (meth) acrylamide and (meth) acrylamide derivatives such as (meth) acryloylmorpholine; and N-vinylamide simple substances such as N-vinylacetamide, N-vinylformamide and N-vinylisobutyramide Examples include a polymer.

  Examples of other monomers other than the above include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate.

The glass transition temperature (Tg) of the polymer constituting the polymer block (A) is 150 ° C. or higher. Since Tg can contribute to heat resistance, it may be, for example, 170 ° C. or higher, 180 ° C. or higher, 190 ° C. or higher, or 200 ° C. or higher. Furthermore, it may be 210 ° C. or higher, 220 ° C. or higher, or 230 ° C. or higher. When Tg is less than 150 ° C., the resulting block copolymer may have insufficient heat resistance and oil resistance. The upper limit of Tg is 350 ° C. due to the limitation of the constituent monomer units that can be used. Tg may be, for example, 280 ° C. or lower, 270 ° C. or lower, and further, for example, 260 ° C. or lower.
Incidentally, the value of Tg can be obtained by differential scanning calorimetry (DSC) as described in Examples described later. Moreover, it can also obtain | require by calculation from the monomer unit which comprises a polymer block.

When the solubility parameter (SP value) of the polymer block (A) is 10.0 or more, it is preferable in that the oil resistance of the block copolymer becomes better. The SP value is more preferably 11.0 or more, further preferably 12.0 or more, and still more preferably 13.0 or more.
The upper limit of the SP value of the polymer block (A) is not particularly limited, but is preferably 30 or less. For example, the SP value may be 20.0 or less, and may be 18.0 or less, for example.

  Regarding the SP value, R.I. F. It can be calculated by the calculation method described in “Polymer Engineering and Science” 14 (2), 147 (1974) written by Fedors. Specifically, it is based on the calculation method shown in Formula (1).

δ: SP value ((cal / cm ³ ) ^1/2 )
ΔE _vap : Heat of molar evaporation of each atomic group (cal / mol)
V: molar volume of each atomic group (cm ³ / mol)

<Acrylic polymer block (B)>
The acrylic polymer block (B) can be obtained by polymerizing a monomer containing an acrylic monomer. An acrylic monomer refers to an unsaturated compound having an acryloyl group such as acrylic acid and an acrylic ester compound. Examples of the acrylate compound include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, 2-acrylic acid 2- Acrylic acid alkyl ester compounds such as ethylhexyl, octyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, stearyl acrylate; cyclohexyl acrylate, methyl cyclohexyl acrylate, tert-butyl cyclohexyl acrylate, cyclododecyl acrylate, etc. Aliphatic cyclic ester compounds of acrylic acid: methoxymethyl acrylate, ethoxymethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, n-propoxy acrylate Chill, n-butoxyethyl acrylate, methoxypropyl acrylate, ethoxypropyl acrylate, n-propoxypropyl acrylate, n-butoxypropyl acrylate, methoxybutyl acrylate, ethoxybutyl acrylate, n-propoxybutyl acrylate, Examples include acrylic acid alkoxyalkyl ester compounds such as n-butoxybutyl acrylate. In addition, an acrylate compound having a functional group such as an amide group, an amino group, a carboxy group, or a hydroxy group may be used.
Among these, an acrylic acid alkyl ester compound having an alkyl group having 1 to 12 carbon atoms or an alkoxyalkyl group having 2 to 8 carbon atoms is preferable in that a block copolymer having excellent flexibility can be obtained. In addition, when the viewpoints of heat resistance and oil resistance are taken into account, the acrylic monomer is an acrylic acid alkyl ester compound having an alkyl group having 1 to 3 carbon atoms or an alkoxyalkyl group having 2 to 3 carbon atoms (acrylic acid). More preferably, the alkyl ester compound A) includes an acrylic acid alkyl ester compound (acrylic acid alkyl ester compound B) having an alkyl group having 4 to 12 carbon atoms or an alkoxyalkyl group having 4 to 8 carbon atoms. The mass ratio of the acrylic acid alkyl ester compound A to the acrylic acid alkyl ester compound B (acrylic acid alkyl ester compound A / acrylic acid alkyl ester compound B) is preferably 10/90 to 90/10, more preferably 40/60 to 85/15.

In the acrylic polymer block (B), the proportion of the structural unit derived from the acrylic monomer is in the range of 20% by mass to 100% by mass in the total structural unit of the acrylic polymer block (B). It is preferably 50% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, and still more preferably 90% by mass to 100% by mass.
In the acrylic polymer block (B), when the structural unit derived from the acrylic monomer is in the above range, a good block copolymer tends to be obtained in terms of mechanical properties.

  As long as the effects of the present invention are not hindered, the acrylic polymer block (B) can use a monomer other than the acrylic monomer as a constituent monomer unit. As monomers other than acrylic monomers, monomers having unsaturated groups other than acryloyl groups can be used, methacryloyl group-containing compounds such as methacrylic acid esters, alkyl vinyl esters, alkyl vinyl ethers and Examples thereof include aliphatic or aromatic vinyl compounds such as styrenes.

The Tg of the polymer constituting the acrylic polymer block (B) is preferably 20 ° C. or less from the viewpoint of the flexibility of the block copolymer. For example, it may be 10 ° C. or lower. Tg is more preferably 0 ° C. or lower, and further preferably −10 ° C. or lower. The lower limit of Tg is −80 ° C. due to the limitation of the constituent monomer units that can be used.
Moreover, when Tg is -20 degrees C or less, it is preferable at the point from which a softness | flexibility is ensured also in a low temperature environment. In consideration of cold resistance, the temperature is more preferably −30 ° C. or lower, and further preferably −40 ° C. or lower.

Moreover, when SP value of an acrylic polymer block (B) is 9.9 or more, it is preferable at the point from which the oil resistance of a block copolymer becomes better. The SP value is more preferably 10.0 or more, still more preferably 10.1 or more, and particularly preferably 10.2 or more.
The upper limit of the SP value of the acrylic polymer block (B) is not particularly limited, but is preferably 20 or less.

  Further, the polymer block (B) may contain a crosslinkable functional group, which is preferable in that it is easy to obtain a block copolymer having high oil resistance. The crosslinkable functional group can be introduced, for example, by copolymerizing a vinyl compound having a crosslinkable functional group. As vinyl compounds having a crosslinkable functional group, unsaturated carboxylic acid, unsaturated acid anhydride, hydroxy group-containing vinyl compound, epoxy group-containing vinyl compound, primary or secondary amino group-containing vinyl compound, reactive silicon group-containing Compounds and the like. These compounds may be used alone or in combination of two or more.

  When the polymer block (B) has a crosslinkable functional group, the amount of the crosslinkable functional group introduced is preferably 0.01 mol% or more based on the total structural unit of the polymer block (B), and more Preferably it is 0.1 mol% or more, More preferably, it is 0.5 mol% or more. When the amount of the crosslinkable functional group introduced is 0.01 mol% or more, it becomes easy to obtain a block copolymer having high oil resistance. On the other hand, from the viewpoint of flexibility, the upper limit of the amount of the crosslinkable functional group introduced is preferably 20 mol% or less, more preferably 10 mol% or less, and further preferably 5 mol% or less. The amount of the crosslinkable functional group introduced can be in the range of 0.01 mol% or more and 20 mol% or less, preferably 0.1 mol% or more and 10 mol based on the total structural unit of the polymer block (B). % Or less, and more preferably 0.5 mol% or more and 5 mol% or less.

<Block copolymer>
The block copolymer in the present invention has one or more of the polymer block (A) and the acrylic polymer block (B). When the block copolymer has two or more polymer blocks (A) and / or acrylic polymer blocks (B), the structure of each block may be the same or different. Moreover, the block copolymer may have polymer blocks other than the said polymer block (A) and the said acrylic polymer block (B) in the range which does not impair the effect of this invention.

  There is no restriction | limiting in particular also about the structure of a block copolymer, Various linear or branched block copolymers, such as AB type | mold diblock polymer or an ABA type | mold and ABC type | mold triblock polymer, can be used. A material having an A- (BA) n-type structure (n is an integer of 1 to 10) is preferable in that good performance can be obtained as an elastomer material. The A- (BA) n-type structure is a polymer block (A)-(acrylic polymer block (B) -polymer block (A)) n-type structure, and when n is 1, the polymer block It is an ABA triblock copolymer comprising (A) -acrylic polymer block (B) -polymer block (A).

  In the block copolymer, the polymer block (A) acts as a hard segment, and the acrylic polymer block (B) acts as a soft segment. As a result, the block copolymer in the present invention exhibits excellent mechanical properties such as elongation at break and strength at break and becomes a material useful as an elastomer.

10 mass% or more and 60 mass% or less are preferable, and, as for the ratio of the polymer block (A) in a block copolymer, 20 mass% or more and 50 mass% or less are more preferable.
The proportion of the acrylic polymer block (B) in the block copolymer is preferably 40% by mass or more and 90% by mass or less, and more preferably 50% by mass or more and 80% by mass or less.

  In the composition of the present invention, the SP value of the polymer block (A) is preferably larger than the SP value of the acrylic polymer block (B), and the SP value of the polymer block (A) and the acrylic weight The SP value of the combined block (B) preferably has a difference of 0.1 or more. When the SP values are different from each other by 0.1 or more, in the block copolymer, the two are appropriately phase-separated, so that it is possible to exhibit performance excellent in mechanical strength. The difference in SP value is more preferably 0.3 or more, further preferably 0.5 or more, still more preferably 0.8 or more, and particularly preferably 1.0 or more. . Further, from the viewpoint of production and the like, the difference in SP value is preferably 10 or less, and more preferably 5.0 or less.

  Moreover, when a polymer block (A) has a crosslinkable functional group, an elastomer material having a smaller compression set value can be obtained by crosslinking using this. The cross-linking may be by reaction between cross-linkable functional groups introduced into the polymer block (A), or as described later, a cross-linking agent having a functional group capable of reacting with the cross-linkable functional group is added. You may go. In the case of the reaction between the crosslinkable functional groups introduced into the polymer block (A), when a reactive silicon group is used as the crosslinkable functional group, the polymerization reaction for producing the block copolymer and the subsequent crosslinking reaction are efficient. Can be done automatically.

  The number average molecular weight (Mn) of the block copolymer is preferably in the range of 10,000 to 500,000. If the number average molecular weight is 10,000 or more, sufficient strength as an elastomer material can be exhibited. Moreover, if it is 500,000 or less, favorable moldability is securable. The number average molecular weight is more preferably in the range of 20,000 to 400,000, and still more preferably in the range of 50,000 to 200,000.

  The molecular weight distribution (Mw / Mn) obtained by dividing the weight average molecular weight (Mw) value of the block copolymer by the value of the number average molecular weight (Mn) is 1.5 or less in terms of moldability. Preferably there is. More preferably, it is 1.4 or less, More preferably, it is 1.3 or less, More preferably, it is 1.2 or less. The lower limit of the molecular weight distribution is 1.0.

<Method for producing block copolymer>
The block copolymer is not particularly limited as long as the block copolymer having the polymer block (A) and the acrylic polymer block (B) is obtained, and a known production method is adopted. Can do. Examples thereof include a method using various controlled polymerization methods such as living radical polymerization and living anion polymerization, a method of coupling polymers having functional groups, and the like. Among these, the living radical polymerization method is preferable because the operation is simple and the method can be applied to a wide range of monomers.

Living radical polymerization may employ any process such as a batch process, a semi-batch process, a dry continuous polymerization process, and a continuous stirred tank process (CSTR). The polymerization method can be applied to various modes such as bulk polymerization without using a solvent, solvent-based solution polymerization, aqueous emulsion polymerization, miniemulsion polymerization or suspension polymerization.
There are no particular restrictions on the type of living radical polymerization method, and reversible addition-cleavage chain transfer polymerization method (RAFT method), nitroxy radical method (NMP method), atom transfer radical polymerization method (ATRP method), organic tellurium compounds Various polymerization methods such as polymerization method using TERP (TERP method), polymerization method using organic antimony compound (SBRP method), polymerization method using organic bismuth compound (BIRP method), and iodine transfer polymerization method can be employed. Among these, the RAFT method, the NMP method, and the ATRP method are preferable from the viewpoints of controllability of polymerization and ease of implementation.

In the RAFT method, controlled polymerization proceeds via a reversible chain transfer reaction in the presence of a specific polymerization control agent (RAFT agent) and a general free radical polymerization initiator. As the RAFT agent, various known RAFT agents such as a dithioester compound, a xanthate compound, a trithiocarbonate compound, and a dithiocarbamate compound can be used.
As the RAFT agent, a monofunctional agent having only one active site may be used, or a bifunctional or more functional agent may be used. From the viewpoint of easily obtaining the block copolymer having the A- (BA) n type structure, it is preferable to use a bifunctional RAFT agent.
Moreover, the usage-amount of a RAFT agent is suitably adjusted with the monomer to be used, the kind of RAFT agent, etc.

As the polymerization initiator used in the polymerization by the RAFT method, known radical polymerization initiators such as azo compounds, organic peroxides and persulfates can be used. An azo compound is preferred because side reactions are unlikely to occur.
Specific examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2, 4-dimethylvaleronitrile), dimethyl-2,2′-azobis (2-methylpropionate), 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1- Carbonitrile), 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), and the like.
The radical polymerization initiator may be used alone or in combination of two or more.

  The proportion of the radical polymerization initiator used is not particularly limited, but from the viewpoint of obtaining a polymer having a smaller molecular weight distribution, the amount of the radical polymerization initiator used relative to 1 mol of the RAFT agent is preferably 0.5 mol or less. More preferably, it is 2 mol or less. From the viewpoint of stably performing the polymerization reaction, the lower limit of the amount of the radical polymerization initiator used relative to 1 mol of the RAFT agent is 0.01 mol. Therefore, the amount of radical polymerization initiator used per 1 mol of RAFT agent is preferably in the range of 0.01 mol to 0.5 mol, and more preferably in the range of 0.05 mol to 0.2 mol.

  The reaction temperature in the polymerization reaction by the RAFT method is preferably 40 ° C. or higher and 100 ° C. or lower, more preferably 45 ° C. or higher and 90 ° C. or lower, and further preferably 50 ° C. or higher and 80 ° C. or lower. If reaction temperature is 40 degreeC or more, a polymerization reaction can be advanced smoothly. On the other hand, if reaction temperature is 100 degrees C or less, while being able to suppress a side reaction, the restrictions regarding the initiator and solvent which can be used are eased.

  In the NMP method, a specific alkoxyamine compound having nitroxide or the like is used as a living radical polymerization initiator, and polymerization proceeds via a nitroxide radical derived therefrom. In the present disclosure, the type of nitroxide radical to be used is not particularly limited, but from the viewpoint of polymerization controllability when polymerizing an acrylate-containing monomer, a compound represented by the general formula (2) is used as the nitroxide compound. Is preferred.

{In the formula, R ¹ represents an alkyl group having 1 to 2 carbon atoms or a hydrogen atom, R ² represents an alkyl group having 1 to ² carbon atoms or a nitrile group, and R ³ represents — (CH ₂ ) m —, m Is 0 to 2, and R ⁴ and R ⁵ are alkyl groups having 1 to 4 carbon atoms}

The nitroxide compound represented by the general formula (2) is primarily dissociated by heating at about 70 to 80 ° C. to cause an addition reaction with the vinyl monomer. In this case, it is possible to obtain a polyfunctional polymerization precursor by adding a nitroxide compound to a vinyl monomer having two or more vinyl groups. Next, the vinyl monomer can be living polymerized by secondary dissociation of the polymerization precursor under heating.
In this case, since the polymerization precursor has two or more active sites in the molecule, a polymer having a narrower molecular weight distribution can be obtained. From the viewpoint of easily obtaining the block copolymer having the A- (BA) n type structure, it is preferable to use a bifunctional polymerization precursor having two active sites in the molecule.
Moreover, the usage-amount of a nitroxide compound is suitably adjusted with the kind etc. of the monomer to be used and a nitroxide compound.

  When the block copolymer is produced by the NMP method, the nitroxide radical represented by the general formula (3) is within a range of 0.001 to 0.2 mol with respect to 1 mol of the nitroxide compound represented by the general formula (2). Polymerization may be performed by adding.

{Wherein R ⁴ and R ⁵ are each an alkyl group having 1 to 4 carbon atoms. }

  By adding 0.001 mol or more of the nitroxide radical represented by the general formula (3), the time for the concentration of the nitroxide radical to reach a steady state is shortened. As a result, the polymerization can be controlled to a higher degree, and a polymer with a narrower molecular weight distribution can be obtained. On the other hand, if the amount of the nitroxide radical added is too large, the polymerization may not proceed. A more preferable addition amount of the nitroxide radical with respect to 1 mol of the nitroxide compound is in a range of 0.01 to 0.5 mol, and a more preferable addition amount is in a range of 0.05 to 0.2 mol.

  The reaction temperature in the NMP method is preferably 50 ° C. or higher and 140 ° C. or lower, more preferably 60 ° C. or higher and 130 ° C. or lower, still more preferably 70 ° C. or higher and 120 ° C. or lower, particularly preferably 80 ° C. or higher and 120 ° C. or lower. It is as follows. If reaction temperature is 50 degreeC or more, a polymerization reaction can be advanced smoothly. On the other hand, if the reaction temperature is 140 ° C. or lower, side reactions such as radical chain transfer tend to be suppressed.

  In the ATRP method, a polymerization reaction is generally performed using an organic halide as an initiator and a transition metal complex as a catalyst. As the organic halide as an initiator, a monofunctional one or a bifunctional or higher one may be used. From the viewpoint of easily obtaining the block copolymer having the A- (BA) n type structure, it is preferable to use a bifunctional compound. Moreover, bromide and chloride are preferable as the kind of halogen.

  The reaction temperature in the ATRP method is preferably 20 ° C. or higher and 200 ° C. or lower, more preferably 50 ° C. or higher and 150 ° C. or lower. If reaction temperature is 20 degreeC or more, a polymerization reaction can be advanced smoothly.

  An A- (BA) n type structure such as an ABA triblock copolymer comprising a polymer block (A) -acrylic polymer block (B) -polymer block (A) is obtained by a living radical polymerization method. In this case, for example, the target block copolymer may be obtained by sequentially polymerizing each block. In this case, as a first polymerization step, a polymer block (A) is obtained by polymerizing a monomer containing 1% by mass to 70% by mass of styrene and 30% by mass to 99% by mass of a maleimide compound. . Next, as a second polymerization step, an acrylic monomer is polymerized to obtain an acrylic polymer block (B). Further, as a third polymerization step, an ABA triblock copolymer is obtained by polymerizing a monomer containing 1% by mass to 70% by mass of styrene and 30% by mass to 99% by mass of the maleimide compound. Can do. In this case, it is preferable to use the above-described monofunctional polymerization initiator or polymerization precursor as the polymerization initiator. By repeating the second polymerization step and the third polymerization step, a higher order block copolymer such as a tetrablock copolymer can be obtained.

  Moreover, when it manufactures by the method containing the two-stage polymerization process shown below, since a target object is obtained more efficiently, it is preferable. That is, as a first polymerization step, an acrylic monomer is polymerized to obtain an acrylic polymer block (B), and then as a second polymerization step, styrene is present in the presence of the acrylic polymer block (B). A polymer block (A) is obtained by polymerizing a monomer containing 1% by mass to 70% by mass of the compound and 30% by mass to 99% by mass of the maleimide compound. Thereby, the ABA triblock copolymer which consists of a polymer block (A) -acrylic polymer block (B) -polymer block (A) can be obtained. In this case, it is preferable to use a bifunctional polymerization initiator or polymerization precursor as the polymerization initiator. According to this method, a process can be simplified compared with the case where each block is polymerized in sequence. Moreover, higher order block copolymers, such as a tetrablock copolymer, can be obtained by repeating said 1st polymerization process and 2nd polymerization process.

  The polymerization of the block copolymer may be carried out in the presence of a chain transfer agent, if necessary, regardless of the polymerization method.

  As the chain transfer agent, known ones can be used. Specifically, ethanethiol, 1-propanethiol, 2-propanethiol, 1-butanethiol, 2-butanethiol, 1-hexanethiol, 2-hexane Thiol, 2-methylheptane-2-thiol, 2-butylbutane-1-thiol, 1,1-dimethyl-1-pentanethiol, 1-octanethiol, 2-octanethiol, 1-decanethiol, 3-decanethiol, 1-undecanethiol, 1-dodecanethiol, 2-dodecanethiol, 1-tridecanethiol, 1-tetradecanethiol, 3-methyl-3-undecanethiol, 5-ethyl-5-decanethiol, tert-tetradecanethiol, 1 -Hexadecanethiol, 1-heptadecanethiol and 1- In addition to alkylthiol compounds having an alkyl group of 2 to 20 carbon atoms such as kutadecanethiol, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, etc. may be mentioned, and one or more of these may be used Can do.

  A known polymerization solvent can be used in the living radical polymerization. Specifically, aromatic compounds such as benzene, toluene, xylene and anisole; ester compounds such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate; ketone compounds such as acetone and methyl ethyl ketone; dimethylformamide, acetonitrile, dimethyl sulfoxide, Examples include alcohol and water. Moreover, you may carry out by aspects, such as block polymerization, without using a polymerization solvent.

  The content of the thermoplastic elastomer is preferably 60 to 99% by mass, more preferably 70 to 95% by mass, and further preferably 75 to 90% by mass in the composition of the present invention.

  The composition of the present invention may contain another block copolymer as a thermoplastic elastomer as long as the effects of the present invention are not impaired, but the content of the block copolymer is the same as that of the block copolymer. Is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more.

<Conductivity imparting agent>
Examples of the conductivity-imparting agent include polymer-type antistatic agents, inorganic conductive fillers, and the like. Examples of the inorganic conductive filler include conductive carbon black, carbon fiber, carbon nanotube, carbon nanofiber, graphite, powder, or fibrous form. Or a metal oxide thereof. From the viewpoint of improving the heat resistance of the composition, the conductivity imparting agent in the present invention is preferably an inorganic conductive filler, and more preferably conductive carbon black.

  Examples of the conductive carbon black include acetylene black obtained by thermally decomposing acetylene gas, furnace black, ketjen black, etc. produced by crude incomplete combustion using crude oil as a raw material. These conductive carbon blacks are different from carbon blacks for pigments added to paints or the like for coloring purposes, and usually have a form in which fine particles are connected. Preferred is ketjen black from the viewpoint of easily reducing the volume resistivity.

  The conductive carbon black has a dibutyl phthalate (DBP) oil absorption measured according to ASTM D2414, preferably 30 ml / 100 g or more, more preferably 100 to 1000 ml / 100 g.

The BET specific surface area of the conductive carbon black is preferably 50 to 3000 m ² / g, more preferably 200 to 2000 m ² / g.

A smaller particle size of the inorganic conductive filler is preferable because it can cope with a thinner sheet shape. On the other hand, the larger the particle size, the smaller the surface area per volume, so the fluidity during melt flow improves. preferable. From these viewpoints, the volume median particle size of the inorganic conductive filler is 0.1 to 500 μm, preferably 0.5 to 100 μm, more preferably 0.8 to 60 μm, and still more preferably 1.0. ˜20 μm. It is known that the particle size can be measured by various measurement principles such as image analysis based on electron microscope observation, Coulter counter, centrifugal sedimentation type, laser diffraction type, etc. It is also known that there are differences in the numerical values obtained by the principle. In the present invention, the median diameter in the volume-based particle size distribution based on image analysis based on electron microscope observation is defined as the volume-median particle diameter (D ₅₀ ). The particle diameter value measured by another measurement principle is based on the common general technical knowledge. It is also possible to convert and use.

  The specific gravity of the inorganic conductive filler means the true specific gravity, and is preferably 1 or more and more preferably 2 or more from the viewpoint of conductivity. Further, from the viewpoint of dispersibility, 10 or less is preferable, and 4 or less is preferable. From these viewpoints, the specific gravity of the inorganic conductive filler is preferably 1 to 10, and more preferably 2 to 4, from the viewpoints of dispersibility and conductivity.

  As a polymer type antistatic agent, a polymer having a polyethylene oxide structure has been known for a long time. However, an alkali metal such as a lithium salt or a sodium salt is added to a polymer having a basic skeleton such as polyether, polyester, polyamine, or polysulfide. What is called a polymer solid electrolyte in which a salt is dissolved is preferable from the viewpoint of higher conductivity. Specifically, for example, a method using a solution in which lithium imide is dissolved in a propylene glycol-based polyether polyol is disclosed in JP-A No. 2002-146178. By using it mixed with a urethane monomer, antistatic performance can be improved. It is disclosed that the urethane rubber which has is obtained. In the thermoplastic elastomer used in the present invention, since the structural unit derived from the maleimide compound in the block copolymer has a high affinity for such an alkali metal salt, it does not take a special method such as mixing at the monomer stage. However, the ionic conductivity of the polymer antistatic agent is easily exhibited, and the bleed out of the polymer antistatic agent hardly occurs.

  When a polymer type antistatic agent is used, it is preferable that the flexibility of the composition is not impaired and may be made more flexible in some cases.

Such polymer-type antistatic agents are generally various polymer substances containing a high concentration of polyether blocks, and are 10 ⁸ to 10 ¹³ Ω / cm ² due to ionic conduction along the polyether. Generates surface resistivity. As the ionic species of such an ion conductive polymer type antistatic agent, sodium, lithium and the like are common, but some of them are nonionic. For the surface resistivity, a resistivity is measured at five points by a four-probe method based on JIS K7194 using a Lorester GP resistivity meter manufactured by Mitsubishi Chemical Analytech.

  Examples of commercially available polymer-type antistatic agents include Pelestat 230, VH230, 303, and 300 manufactured by Sanyo Kasei Co., Ltd., Sanconol TBX35, TBX25, TBX310, TBX320, and TBX8210 manufactured by Sanko Chemical Co., Ltd.

  The smaller the content of the conductivity-imparting agent in the composition of the present invention is, the higher the melt fluidity of the composition is, while the larger the content is, the higher the conductivity of the composition is. From these viewpoints, the content of the conductivity-imparting agent is 1 to 100 parts by volume, preferably 2 to 50 parts by volume, more preferably 5 to 40 parts by volume with respect to 100 parts by volume of the thermoplastic elastomer. .

  In addition, the effect of the conductivity imparting agent tends to appear mainly based on the size of the surface area rather than the mass of the conductivity imparting agent. In that sense, the ratio of the thermoplastic elastomer and the conductivity imparting agent is more than the mass part. Also, the trend of the effect can be better reflected when the volume part is defined. When the specific gravity of each of the thermoplastic elastomer and the conductivity imparting agent is known, the mass part can be converted into the volume part by the specific gravity. The volume part of the conductivity-imparting agent can be calculated from the true specific gravity.

  It is known that the addition of an imparting agent to the elastomer increases the hardness, but in the combination of the thermoplastic elastomer of the present invention and the conductivity imparting agent, the particle size and volume part of the conductivity imparting agent are within the above ranges. When limited to, the surface hardness of the composition is not so large, and flexibility can be maintained.

<Elastomer composition>
The composition of this invention is good also as an aspect of the composition which mix | blended the well-known additive etc. as needed. In particular, when the block copolymer contains a crosslinkable functional group in at least one of the polymer block (A) and the acrylic polymer block (B), a crosslinker and a crosslink accelerator that can react with the functional group. Etc. are preferably contained.

  When the block copolymer includes a structural unit derived from a crosslinkable monomer having a carboxyl group, a polyvalent amine, a polyfunctional isocyanate, or the like is preferably used as the crosslinking agent.

  Examples of the polyvalent amine include aliphatic diamine compounds such as hexamethylene diamine, hexamethylene diamine carbamate, and N, N'-dicinnamylidene-1,6-hexane diamine; and alicyclic compounds such as 4,4'-methylenebiscyclohexylamine carbamate. Diamine compound; 4,4′-methylenedianiline, m-phenylenediamine, 4,4′-diaminodiphenyl ether, 4,4 ′-(m-phenylenediisopropylidene) dianiline, 4,4 ′-(p-phenylenediene) Isopropylidene) dianiline, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 4,4'-diaminobenzanilide, m-xylylenediamine, p-xylylenediamine, 1,3,5 -Benzyltriamine, 1,3,5-benzenetriaminomethyl, etc. Family diamine compounds and the like.

  Examples of the polyfunctional isocyanate include hexamethylene diisocyanate, dimethyldiphenylene diisocyanate, and isophorone diisocyanate.

  When using a polyvalent amine, guanidine compounds such as 1,3-di-o-tolylguanidine and 1,3-diphenylguanidine; imidazole compounds such as 2-methylimidazole and 2-phenylimidazole; phosphoric acid, carbonic acid, bicarbonate , Salts of weak acids such as alkali metal salts (Li, Na, K) of acids such as stearic acid and lauric acid; thirds such as triethylenediamine, 1,8-diazabicyclo- [5.4.0] undecene-7 Tertiary amines; Tertiary phosphine compounds such as triphenylphosphine and tri (methyl) phenylphosphine; Cross-linking aids such as quaternary onium salts such as tetrabutylammonium bromide, tetrabutylammonium chloride and octadecyltri-n-butylammonium bromide It is preferable to use together.

  When the block copolymer includes a structural unit derived from a crosslinkable monomer having an epoxy group, examples of the crosslinking agent include organic carboxylic acid ammonium salt, dithiocarbamate, polyvalent carboxylic acid or anhydride, A combination with a quaternary ammonium salt or a phosphonium salt is preferably used.

  Examples of the organic carboxylic acid ammonium salt include ammonium benzoate.

  Examples of the dithiocarbamate include zinc salts such as dimethyldithiocarbamic acid, diethyldithiocarbamic acid, and dibenzyldithiocarbamic acid, iron salts, tellurium salts, and the like.

  Examples of the polyvalent carboxylic acid include malonic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, citric acid, tartaric acid, and phthalic acid. Examples of the quaternary ammonium salt include tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, n-dodecyltrimethylammonium bromide, octadecyltrimethylammonium bromide and the like. Examples of the phosphonium salt include triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide, triphenylbenzylphosphonium iodide, triethylbenzylphosphonium chloride, tetrabutylphosphonium bromide and the like.

  When the block copolymer includes a structural unit derived from a crosslinkable monomer having a hydroxyl group, a polyfunctional isocyanate or the like is preferably used as the crosslinking agent.

  When the block copolymer includes a structural unit derived from a crosslinkable monomer having a primary or secondary amino group, a polyfunctional isocyanate, a polyfunctional glycidyl compound, or the like is preferably used as the crosslinking agent.

  When the block copolymer contains a polymerizable unsaturated group, 1,2-ethanedithiol, 1,4-butanethiol, 1,10-decanethiol, 1,4-benzenethiol and other dithiol compounds, or ethane- An ene-thiol reaction with a polyvalent thiol such as a trithiol compound such as 1,1,1-trithiol or 1,3,5-benzenetrithiol can be used.

  When the crosslinkable group of the block copolymer is a reactive silicon group, it causes a crosslinking reaction due to moisture, so there is no need to add a crosslinking agent or the like.

  The composition of the present invention may contain other thermoplastic resins and thermoplastic elastomers as long as the effects of the present invention are not impaired. Among these, the polar elastomer can improve the fusion property of the composition to the polar resin. The polar elastomer is not particularly limited, and examples thereof include NBR (nitrile rubber), polyurethane rubber, epichlorohydrin rubber, polyamide thermoplastic elastomer, acrylic thermoplastic elastomer, and the like.

  The composition of the present invention is, as necessary, a polyolefin resin such as polypropylene and polyethylene, a reinforcing agent such as silica, carbon fiber, and glass fiber, an inorganic filler, and an insulating heat conduction as long as the effects of the present invention are not impaired. Dispersants such as conductive fillers, metal soaps, pigments, hydrated metal compounds, red phosphorus, ammonium polyphosphate, antimony, silicone and other flame retardants, antistatic agents, tackifiers, thermal stabilizers, antioxidants, light stability Various additives such as an agent, an ultraviolet absorber, an antiblocking agent, a sealability improver, a release agent, a colorant, and a fragrance may be contained.

  The composition of the present invention can be obtained, for example, by mixing a thermoplastic elastomer and a conductivity-imparting agent, and further, if necessary, raw materials containing other additives and solidifying by cooling.

  “Mixing” as used in the present invention is not particularly limited as long as various components are mixed well, and various components may be dissolved and mixed in a soluble organic solvent, or by melt kneading. You may mix.

  In the case of melt mixing, a kneader or a general melt extruder can be used, and it is preferable to use a single screw extruder for improving the kneading state. As for the supply to the extruder, various components may be directly supplied to the extruder, a mixture of various components using a mixing device such as a Henschel mixer in advance may be provided from one hopper, or two hoppers. Each of the components may be charged and used while being quantified with a screw or the like under the hopper.

  The thermoplastic elastomer composition can be used by directly forming a molded product obtained by melting and mixing into pellets, powders before forming a molded product to be used as a final product depending on the application. Intermediate products such as sheets can be used. For example, it is melt-mixed by an extruder, extruded into a strand, and cut into pellets such as a cylindrical shape and a rice grain by a cutter while cooling in cold water. The obtained pellets can be usually formed into a predetermined sheet-like molded product or a molded product by a molding method such as injection molding, extrusion molding, or press molding.

The storage elastic modulus at 23 ° C. of the composition of the present invention is preferably 1 × 10 ⁹ Pa or less, more preferably 1 × 10 ⁵ to 8 × 10 ⁸ Pa, and further preferably 1 × 10 from the viewpoint of flexibility. ^{6 to} 5 × 10 ⁸ Pa. In the present invention, the storage elastic modulus is based on 30 Hz dynamic viscoelasticity measurement.

The storage elastic modulus at 150 ° C. of the composition of the present invention is preferably 1 × 10 ⁷ Pa or more, more preferably 1 × 10 ⁷ to 1 × 10 ⁹ Pa, more preferably 1.5 from the viewpoint of heat resistance. It is * 10 < ⁷ > -5 * 10 < ⁸ > Pa.

  A molded body is obtained by appropriately heat-molding the thermoplastic elastomer composition of the present invention according to a conventional method. The use of the molded product obtained by thermoforming the thermoplastic elastomer composition of the present invention is not particularly limited, and general styrene elastomers, polyolefin elastomers, polyurethane elastomers, polyamide elastomers, acrylic elastomers And polyester elastomers can be used.

  The apparatus used for manufacturing a molded body using the thermoplastic elastomer composition of the present invention can be any molding machine capable of melting a molding material. Examples thereof include a kneader, an extrusion molding machine, an injection molding machine, a press molding machine, a blow molding machine, and a mixing roll.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Various physical properties of the raw materials used in Examples and Comparative Examples were measured by the following methods.

<Block copolymer>
[Composition ratio]
The composition ratio of the block copolymer is identified and calculated from ¹ H-NMR measurement by dissolving the sample in deuterated chloroform.

[Glass transition temperature (Tg)]
The glass transition temperature (Tg) of the block copolymer is determined from the intersection of the base line of the heat flux curve obtained using a differential scanning calorimeter and the tangent at the inflection point. About 10 mg of the sample was cooled to −50 ° C. and held for 5 minutes, then heated to 300 ° C. at 10 ° C./min, subsequently cooled to −50 ° C., held for 5 minutes, and then 10 ° C. / It is obtained under conditions where the temperature is raised to 350 ° C. in min.
Measuring instrument: DSC6220 manufactured by SII Nano Technology
Measurement atmosphere: under nitrogen atmosphere In addition, by performing differential scanning calorimetry of the block copolymer, inflection points corresponding to the polymer block (A) and the acrylic polymer block (B) are obtained. The Tg of the polymer block can be determined.

(Molecular weight measurement)
Gel permeation chromatography (GPC) measurement is performed under the conditions described below to obtain a number average molecular weight (Mn) and a weight average molecular weight (Mw) in terms of polystyrene. Moreover, molecular weight distribution (Mw / Mn) is calculated from the obtained value.
○ Measurement conditions Column: Tosoh TSKgel SuperMultipore HZ-M × 4 Solvent: Tetrahydrofuran Temperature: 40 ° C
Detector: RI
Flow rate: 600 μL / min

<Conductivity imparting agent>
[Volume-median particle size _{(D 50)]}
About a powdery thing, length measurement is performed by image analysis about arbitrary 100 particles using an electron microscope. Specifically, the average value of the longest diameter and the shortest diameter is defined as the particle diameter of the particles, and the median diameter in the volume-based particle size distribution is calculated. In addition, when primary particles of several nanometer level are connected to form secondary particles such as ketjen black, the length of the secondary particles is measured.
[BET specific surface area]
Based on the method of JIS Z8830, a BET nitrogen adsorption isotherm is measured using AUTOSORB-1 manufactured by Quantachrome, and a specific surface area is calculated from the nitrogen adsorption amount using a BET multipoint method.

[Dibutylphthalate (DBP) oil absorption]
It is measured by a method based on ASTM D2414.

Synthesis Example 1 of RAFT Agent
Add 1-dodecanethiol (42.2 g), 20% aqueous KOH solution (63.8 g) and trioctylmethylammonium chloride (1.5 g) to an eggplant-shaped flask and cool in an ice bath to obtain carbon disulfide (15.9 g). ) And tetrahydrofuran (hereinafter also referred to as “THF”) (38 ml) were added and stirred for 20 minutes. A THF solution (170 ml) of α, α′-dichloro-p-xylene (16.6 g) was added dropwise over 30 minutes. After reacting at room temperature for 1 hour, the mixture was extracted from chloroform, washed with pure water, dried over anhydrous sodium sulfate, and concentrated on a rotary evaporator. The obtained crude product is purified by column chromatography and then recrystallized from ethyl acetate, whereby 1,4-bis (n-dodecylsulfanylthiocarbonylsulfanylmethyl) benzene represented by the following formula (4) is obtained. (Hereinafter also referred to as “DLBTTC”) was obtained in a yield of 80%. ^{From the 1} H-NMR measurement, the peak of the target product was confirmed at 7.2 ppm, 4.6 ppm, and 3.4 ppm.

Production Example 1 of Acrylic Polymer Block (B)
The RAFT agent (DLBTC) (4.28 g) obtained in Synthesis Example 1 and 2,2′-azobis (2-methylbutyronitrile) (hereinafter “ABN-E”) were added to a 1 L flask equipped with a stirrer and a thermometer. (Also referred to as “)” (0.25 g), ethyl acrylate (651 g) and anisole (287 g) were charged, sufficiently deaerated by nitrogen bubbling, and polymerization was started in a thermostatic bath at 60 ° C. After 3 hours and 30 minutes, the reaction was stopped by cooling to room temperature. The polymer B1 was obtained by reprecipitation purification from hexane and vacuum drying. The molecular weight of the obtained polymer B1 was Mn69200, Mw75500, and Mw / Mn1.09 from GPC (gel permeation chromatography) measurement (polystyrene conversion).

Production Example 2 of Acrylic Polymer Block (B)
In addition to ethyl acrylate, using n-butyl acrylate and 2-methoxyethyl acrylate, changing the amount of charge as shown in Table 1, and adjusting the reaction time appropriately, the same operation as in Production Example 1 And polymer B2 was obtained. The molecular weight of the polymer B2 was measured and shown in Table 1. Moreover, when the composition ratio of ethyl acrylate, n-butyl acrylate, and 2-methoxyethyl acrylate in the polymer was determined from ¹ H-NMR measurement, ethyl acrylate / n-butyl acrylate / acrylic acid 2- Methoxyethyl (mass ratio) = 49/25/26.

Production example 1 of block copolymer
In a 1 L flask equipped with a stirrer and a thermometer, the polymer B1 (87.0 g), ABN-E (0.10 g), N-phenylmaleimide (28.8 g) obtained in Production Example 1 and styrene (32.2 g) were obtained. ) And anisole (342 g) were thoroughly deaerated by nitrogen bubbling, and polymerization was started in a constant temperature bath at 60 ° C. After 3 hours, the reaction was stopped by cooling to room temperature. Block polymerization 1 shown in Table 3 was obtained by reprecipitation purification from methanol, and vacuum drying of the polymerization solution. As a result of measuring the molecular weight of the obtained block copolymer 1, Mn99,000, Mw111,000, and Mw / Mn were 1.12.

The block copolymer 1 is a triblock copolymer having a structure of polymer block (A) -acrylic polymer block (B) -polymer block (A). ^When the composition ratio of N-phenylmaleimide and styrene in the polymer block (A) was determined from ¹ H-NMR measurement, N-phenylmaleimide / styrene (mass ratio) = 51/49, and the polymer block (A ) And the acrylic polymer block (B) were (A) / (B) (mass ratio) = 30/70. The block copolymer 1 was evaluated as an elastomer, and the results are shown in Table 3.

Production example 2 of block copolymer
Block copolymers 2 to 4 were obtained in the same manner as in Production Example 1 except that the types and amounts of raw materials charged into the flask were changed as shown in Table 2 and the reaction time was appropriately adjusted. Molecular weight of each block copolymer, composition ratio of polymer block (A) by ¹ H-NMR measurement, and composition ratio of polymer block (A) and acrylic polymer block (B) in the block copolymer Are described in Table 3.

In addition, the SP value of the polymer block (A) and the acrylic polymer block (B) is determined based on the composition ratio of the polymer block (A) and the composition ratio of the acrylic polymer block (B) by ¹ H-NMR measurement. Using the calculation formula described above (formula (1)), the results are shown in Table 3. Moreover, based on the differential scanning calorimetry of the block copolymers 1 to 4, Tg of the polymer block (A) and the acrylic polymer block (B) was obtained and listed in Table 3.

Examples 1-10 and Comparative Examples 1-4
Ingredients (mass ratio) shown in Tables 4 and 5 were charged with raw material components into a mixer and dry blended.

  Details of raw material components other than the block copolymers 1 to 4 are as follows.

〔Thermoplastic resin〕
Hard acrylic resin with acrylic rubber: PMMA (polymethyl methacrylate) + acrylic rubber, Parapet SA-1000NP (manufactured by Kuraray Co., Ltd.)
Soft acrylic resin: MMA (methyl methacrylate) / BA (butyl acrylate) block copolymer, Clarity LA2140e (manufactured by Kuraray Co., Ltd.)
Heat-resistant polyester elastomer: Perprene S-1002 (manufactured by Toyobo Co., Ltd.)
[Conductivity imparting agent]
Ketjen Black: Ketjen Black EC600JD (manufactured by Lion), DBP oil absorption: 495 ml / 100 g, D ₅₀ : 1.5 μm (secondary particle size), BET specific surface area: 1270 m ² / g
Pitch-based carbon fiber: Dialead KM223HM N8500N0100 (Mitsubishi Resin Co., Ltd.), average fiber length: 50 to 200 μm, fiber diameter: 10 μm, water absorption: 0.4 mass%
Ion conductive polymer: Sanconol TBX-8310 (manufactured by Sanko Chemical Co., Ltd.), ethylene oxide-propylene oxide-allyl glycidyl ether copolymer, lithium fluoromethanesulfonate (CF ₃ SO ₃ Li) and adipic acid ester Mixture, lithium salt content: 10% by mass
[Crosslinking agent]
Cheminox AC-6 (Unimatex, hexamethylenediamine carbamate)
[Dispersant]
SM1000 (manufactured by Sakai Chemical Industry Co., Ltd., magnesium stearate metal soap)
〔Antioxidant〕
Irganox B225 (manufactured by BASF)

Thereafter, the obtained mixture was melt-kneaded with an extruder (continuous kneader) under the following conditions to produce pellets of a thermoplastic composition.
[Melting and kneading conditions]
Extruder: KZW32TW-60MG-NH (manufactured by Technobel)
Cylinder temperature: 180-260 ° C
Screw rotation speed: 200-650 r / min

  The flexibility, heat resistance, and conductivity of the obtained thermoplastic elastomer composition were evaluated by the following methods. The results are shown in Tables 4 and 5.

[Flexibility and heat resistance]
A test piece with a thickness of 2 mm and a width of 12 mm molded by hot pressing is set on ARES G-2 manufactured by TA Instruments, and the temperature rise rate is 5 ° C / min in a torsion mode (twist) between 25 mm in length. The viscoelasticity was measured at -30 ° C to 200 ° C at 30 Hz, and the storage elastic modulus G 'at 23 ° C and 150 ° C was measured. The smaller the storage elastic modulus G ′ at 23 ° C., the better the flexibility, and the larger the storage elastic modulus G ′ at 150 ° C., the better the heat resistance.

〔Conductivity〕
Using a Lorester GP resistivity meter manufactured by Mitsubishi Chemical Analytech Co., with a four-probe method according to JIS K7194, resistance was measured at 5 points on a test piece of 2 mm thickness, 50 mm width, and 80 mm length molded by hot press. The volume resistivity was calculated by measuring the rate. The volume resistivity means that the smaller the value, the higher the conductivity of the molded body.

  From the above results, it can be seen that the thermoplastic elastomer compositions of Examples 1 to 10 have a good balance of flexibility, heat resistance, and conductivity as compared with Comparative Examples 1 to 4.

  Furthermore, the compression set and A hardness of the thermoplastic elastomer compositions of Example 1 and Example 5 were measured by the following methods. The results are shown in Table 6.

<Measurement of compression set>
A film sample having a thickness of 2 mm was prepared in accordance with the sample preparation procedure in the initial tensile physical properties, and a disk-shaped molded body prepared by stacking seven sheets cut into a disk shape having a diameter of 29 mm was hot-pressed at 200 ° C. What adjusted thickness to 12.5 mm +/- 0.5mm was used as a test piece, and it measured by the compression set test prescribed | regulated to JISK6262.
Specifically, at the standard temperature (23.2 ± 2 ° C.), the diameter and thickness of the test piece were 29.0 ± 0.5 mm (diameter) and 12.5 mm ± 0.5 mm (thickness), respectively. It was confirmed that the test piece was sandwiched between compression plates provided with spacers having a thickness of 9.3 to 9.4 mm. The test piece was held at 70 ° C. for 24 hours under the condition that the ratio of compressing the test piece was 25% by volume, and then the thickness of the central part of the test piece was measured after removing the compression plate at 23 ° C. and leaving it for 30 minutes.
The measurement result was applied to the following compression set calculation formula to calculate the compression set (%).
Compression set (%) = (t ₀ −t ₂ ) / (t ₀ −t ₁ ) × 100
(Where t ₀ is the original thickness (mm) of the test piece, t ₁ is the thickness of the spacer (mm), and t ₂ is the thickness of the test piece 30 mm after removal from the compression device (mm). Indicate)
After compression release, the compression set value when the specimen completely returns to the dimension before compression is 0%, and the dimension shape does not return to its original shape even when released from compression. Since the compression set value in this case is 100%, the smaller the compression set value is between 0% and 100%, the better the recovery.

<A hardness>
A 2 mm thick film produced in the same procedure as the compression set was allowed to stand in a constant temperature and humidity chamber (temperature 23 ° C., relative humidity 50%) for 24 hours or more to stabilize the state, and then three sheets were used. The A hardness was measured according to JIS K 7215 “Durometer hardness test method for plastics”.

  From the above results, in general, the compression set tends to decrease as it becomes harder, whereas when the block copolymer is cross-linked, the hardness is almost equal, It can be seen that the compression set is greatly improved.

  The thermoplastic elastomer composition of the present invention is suitably used as a wide range of industrial materials that require electrical conductivity, such as antistatic mats, antistatic grips, electromagnetic wave suppression sheets, cable covers, and touch pens.

Claims (6)

  A thermoplastic elastomer comprising a block copolymer having a polymer block (A) containing a structural unit derived from styrenes and a maleimide compound, and an acrylic polymer block (B), and 100 parts by volume of the thermoplastic elastomer A thermoplastic elastomer composition containing 1 to 100 parts by volume of a conductivity imparting agent, wherein the polymer block (A) is derived from a maleimide compound in all structural units of the polymer block (A). A thermoplastic elastomer composition, which is a polymer having a structural unit of 30% by mass to 99% by mass and a glass transition temperature (Tg) of 150 ° C. or higher.   The block copolymer has a polymer block (A)-(acrylic polymer block (B) -polymer block (A)) n-type structure (n is an integer of 1 to 10). The thermoplastic elastomer composition as described. The thermoplastic elastomer composition according to claim 1 or 2, wherein the storage elastic modulus by 30 Hz dynamic viscoelasticity measurement is 1 × 10 ⁹ Pa or less at 23 ° C. and 1 × 10 ⁷ Pa or more at 150 ° C.   The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein at least one of the polymer block (A) and the acrylic polymer block (B) has a crosslinkable functional group.   The thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the conductivity-imparting agent is an inorganic conductive filler having a volume median particle size of 0.1 to 500 µm by image analysis based on observation with an electron microscope.   The molded object obtained by heat-molding the thermoplastic elastomer composition in any one of Claims 1-5.