KR102501480B1 - Antistatic resin composition, method for producing antistatic resin composition, and packing material for electronic component - Google Patents

Abstract

An antistatic resin composition that exhibits excellent antistatic performance and is also excellent in transparency is provided.
An antistatic resin composition comprising a block copolymer (b) and a donor/acceptor molecular compound (c),
The block copolymer (b) is a block copolymer containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit, and has a polymer block mainly composed of the vinyl aromatic hydrocarbon monomer unit, and the vinyl aromatic hydrocarbon monomer unit is 30 to 90 mass %, the conjugated diene monomer unit is 70 to 10% by mass,
When the total amount of the block copolymer (b) and the donor/acceptor molecular compound (c) is 100 mass%, the content of the donor/acceptor molecular compound (c) is 0.5 mass% or more and 5 mass% % or less, the antistatic resin composition.

Description

Antistatic resin composition, manufacturing method of antistatic resin composition, and packaging material for electronic parts

The present invention relates to an antistatic resin composition, a method for producing the antistatic resin composition, and an electronic component packaging material.

In general, vinyl aromatic hydrocarbon-based resins (for example, styrene-based resins) are excellent in molding processability, rigidity, transparency, etc., are inexpensive, have low specific gravity, and are economically excellent, so they are used as vinyl aromatic hydrocarbon-based resins. Molded articles are widely used in various fields, such as injection molded articles, sheet-like molded articles extruded from a T die, annular or prismatic tubular molded extruded articles extruded from a mold release mold, and the like.

Among them, carrier tapes for mounting and packing electronic parts such as integrated circuits (ICs) and large-scale integrated circuits (LSIs) in electronic devices, connectors, and magazine tubes for mounting and packing various semiconductor parts (also called magazine sticks) and sheet-shaped molded articles made of vinyl aromatic hydrocarbon-based resins such as impact-resistant polystyrene and transparent MBS resin (methyl methacrylate/butadiene/styrene copolymer resin) for packaging materials for various electronic parts, such as transport trays for packing liquid crystal panels and the like. Tubular extruded articles are widely used.

Electronic parts packaging materials such as carrier tapes, magazine tubes, and transport trays have mechanical properties such as rigidity and impact resistance from their usage form, do not generate burrs during slit processing, or have thickness variations during vacuum forming. There are a wide range of required characteristics, such as molding processability to obtain a uniform thickness, transparency (visibility), and antistatic properties to prevent damage or destruction of electronic parts due to static electricity. In order to improve these properties and obtain a better balance of physical properties, various improvement studies have been conducted.

In particular, as an antistatic material based on a vinyl aromatic hydrocarbon-based resin, conventionally, a composition obtained by blending a styrene-based resin with conductive carbon such as Ketjen Black has been widely known.

A conventionally proposed styrenic antistatic material in which conductive carbon is mixed with a styrenic resin exhibits a surface resistivity of about 10 ⁵ Ω/□ and expresses an extremely low surface resistivity that is indispensable depending on the type of electronic component. Depending on the electronic component, such a low surface resistivity is not necessarily indispensable, and there are many electronic components where even a surface resistivity of about 10 ¹⁰ Ω/□ is sufficient.

On the other hand, as a disadvantage of the antistatic material blended with conductive carbon, there is a problem that the visibility is poor because the color of the molded product is black and opaque, and it is difficult to check the contents in a packaged state. In addition, when electronic components are mounted on molded electronic component packaging materials and actually transported, conductive carbon is detached due to friction between the contact portion between the electronic components and the packaging material due to vibration during transport, and the detached conductive carbon adheres to the electronic components. Problems that can cause contamination, such as becoming, are also pointed out.

On the other hand, technology development related to a resin composition exhibiting antistatic performance without using conductive carbon has been conventionally made.

For example, a technique related to a resin composition obtained by blending a high molecular type conductive polymer having a polyoxyalkylene chain with a thermoplastic resin such as a styrenic resin has been proposed (see, for example, Patent Document 1).

However, in general, a high molecular type conductive polymer has a lower refractive index than a base resin, a styrene-based resin, and an electronic component packaging material containing a resin composition blended with a high molecular type conductive polymer has a large discrepancy in their refractive indices, resulting in cloudiness. There is a problem that the visibility is impaired. Furthermore, in order to develop antistatic properties, it is necessary to blend a large amount of a high-molecular-type conductive polymer at a content of usually 10% or more, and the polymer structure has a low elastic modulus and a decrease in the rigidity of the resin composition. There is also a problem that the characteristics change greatly.

In addition, as a method for obtaining an antistatic resin composition, a method of adding a surfactant, which is a general-purpose antistatic agent, to a thermoplastic resin is also conventionally known.

However, since surfactant-type antistatic agents develop performance by bleeding out on the surface of molded articles, when the surface of molded articles is wiped with water, the antistatic performance is temporarily lowered and the surface resistivity is increased. Stability in antistatic performance has a task in Furthermore, since the antistatic agent itself bleeds out on the surface of the molded product, it may adhere to the electronic component as the content and cause contamination, making it unsuitable for use as a packaging material for electronic components.

Therefore, in recent years, as a new type of antistatic agent, an antistatic resin composition using a donor/acceptor molecular compound containing an organic boron compound and a nitrogen-containing compound and adding this to a thermoplastic resin has been proposed (for example, patent See Document 2, Non-Patent Document 1).

This is an antistatic agent that introduces the concept of a molecular compound. This antistatic resin composition, unlike the conventional surfactant type that bleeds out to the surface of a molded product and exhibits an antistatic effect, combines an electron donor and an acceptor to instantly transfer and accept charges, thereby reducing the charged charge. is to instantaneously attenuate to express an antistatic effect.

Japanese Unexamined Patent Publication No. 2011-6604 Japanese Patent No. 5734491

Magazine "Plastics Age" April 2018, pages 47 to 52

However, an antistatic resin composition using a donor/acceptor molecular compound containing the organic boron compound and a nitrogen-containing compound also has a problem.

What exhibits antistatic performance is a so-called crystalline polyolefin resin such as PE, PP, or cyclic polyolefin, or a heteroatom other than a hydrocarbon such as polyamide, PET resin, ABS resin, polyvinyl chloride, or polyacetal in the backbone of the polymer. It is limited to so-called polar resins containing more than a certain concentration. That is, in general-purpose polystyrene (also referred to as GPPS), rubber-modified polystyrene (also referred to as HIPS), and methyl methacrylate/styrene copolymer resin (also referred to as MS resin) having a methyl methacrylate content of about 20% by mass, for example, 4 Even if the donor/acceptor type molecular compound, which is usually considered to be a sufficient amount by mass%, is blended, the effect of lowering the surface resistivity is not obtained, and there is a problem that the antistatic performance is not expressed.

Therefore, the present invention, in view of the above-mentioned problems of the prior art, even when a styrene-based resin such as general-purpose polystyrene (GPPS), rubber-modified polystyrene (HIPS) containing graft rubber particles, or styrene-acrylic copolymer resin is used as a base resin. , an antistatic resin composition in which the donor/acceptor molecular compound is blended, in which the original properties of the donor/acceptor molecular compound are incorporated, exhibits excellent antistatic performance, and also has excellent transparency; and It aims at providing a manufacturing method.

As a result of intensive studies, the present inventors have found that an antistatic resin composition capable of exhibiting excellent antistatic performance and transparency by combining a donor/acceptor type molecular compound and a specific block copolymer and further optimizing the composition. They found what was to be obtained and came to complete the present invention.

That is, this invention is as follows.

[One]

a block copolymer (b);

Donor/acceptor type molecular compound (c)

An antistatic resin composition comprising

The block copolymer (b) is a block copolymer containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit, and has a polymer block mainly composed of the vinyl aromatic hydrocarbon monomer unit, and the vinyl aromatic hydrocarbon monomer unit is 30 to 90 mass %, the conjugated diene monomer unit is 70 to 10% by mass,

When the total amount of the block copolymer (b) and the donor/acceptor molecular compound (c) is 100 mass%, the content of the donor/acceptor molecular compound (c) is 0.5 mass% or more and 5 mass% % or less, the antistatic resin composition.

[2]

The antistatic resin composition according to [1] above, wherein the surface resistivity is 1×10 ¹² Ω/□ or less.

[3]

A vinyl aromatic hydrocarbon-based resin (a);

a block copolymer (b);

Donor/acceptor type molecular compound (c)

An antistatic resin composition comprising

The block copolymer (b) is a block copolymer containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit, and has a polymer block mainly composed of the vinyl aromatic hydrocarbon monomer unit, and the vinyl aromatic hydrocarbon monomer unit is 30 to 90 mass %, the conjugated diene monomer unit is 70 to 10% by mass,

When the total amount of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100% by mass, the mass ratio of the vinyl aromatic hydrocarbon-based resin (a) is 81% by mass or less, and the block copolymer The mass ratio of (b) is 19% by mass or more and less than 100% by mass;

The donor/acceptor molecular compound ( The content of c) is 0.5 mass % or more and 5 mass % or less,

An antistatic resin composition having a surface resistivity of 1×10 ¹² Ω/□ or less.

[4]

The vinyl aromatic hydrocarbon-based resin (a)

Homopolymers of vinyl aromatic hydrocarbon monomers (a1);

Graft copolymers (a2) of vinyl aromatic hydrocarbon monomers and

The antistatic resin composition according to [3] above, which is any one selected from the group consisting of a random copolymer (a3) of a vinyl aromatic hydrocarbon monomer unit and (meth)acrylic acid and/or (meth)acrylic acid alkylester monomer unit.

[5]

In the melt flow rate (MFR) under the 200 ° C. 5 kg load condition specified in ISO1133,

The relationship between the MFR (hereinafter referred to as MFRa) of the vinyl aromatic hydrocarbon-based resin (a) and the MFR (hereinafter referred to as MFRb) of the block copolymer (b),

The antistatic resin composition according to the above [3] or [4], which satisfies any one of the following conditions (i) to (iv).

<Condition (i)>

When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 0% by mass and 30% by mass or less, and the component (b) is 70% by mass or more and 100% by mass If less than

Regardless of the numerical value of MFRa and MFRb, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.5% by mass or more and 5% by mass less than %.

<Condition (ii)>

When the total of the component (a) and the component (b) is 100% by mass, the component (a) is greater than 30% by mass and not more than 50% by mass, and the component (b) is less than 70% by mass 50% by mass If more than

MFRa<MFRb . . . (Equation 1)

In the case of a relationship, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.5% by mass or more and 5% by mass or less,

MFRa≥MFRb . . . (Equation 2)

In the case of a relationship, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.9% by mass or more and 5% by mass or less.

<Condition (iii)>

When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 50% by mass and 70% by mass or less, and the component (b) is less than 50% by mass and 30% by mass If more than

MFRa<MFRb . . . (Equation 1)

The relationship of is satisfied, and when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.9% by mass or more and 5% by mass or less.

<Condition (iv)>

When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 70% by mass and 81% by mass or less, and the component (b) is less than 30% by mass and 19% by mass If more than

MFRa<MFRb . . . (Equation 1)

The relationship of is satisfied, and when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 3% by mass or more and 5% by mass or less.

[6]

In the melt flow rate (MFR) under the 200 ° C. 5 kg load condition specified in ISO1133,

In the relationship between the MFR (hereinafter referred to as MFRa) of the vinyl aromatic hydrocarbon-based resin (a3) and the MFR (hereinafter referred to as MFRb) of the block copolymer (b),

The antistatic resin composition according to [4] above, which satisfies the condition (v) or (vi) below.

<Condition (v)>

When the sum of the component (a3) and the component (b) is 100% by mass, the component (a3) is more than 0% by mass and 20% by mass or less, and the component (b) is 80% by mass or more and 100% by mass If less than, regardless of the values of MFRa and MFRb,

When the sum of the component (a3), the component (b), and the component (c) is 100% by mass, (c) is 0.5% by mass or more and 5% by mass or less.

<condition (vi)>

When the sum of the component (a3) and the component (b) is 100% by mass, the component (a3) is more than 20% by mass and 50% by mass or less, and the component (b) is less than 80% by mass and 50% by mass If more than

MFRa<MFRb . . . (Equation 1)

is satisfied, and when the sum of the component (a3), the component (b), and the component (c) is 100% by mass, the component (c) is 3% by mass or more and 5% by mass or less.

[7]

The antistatic resin composition according to any one of [1] to [6] above, wherein the donor/acceptor molecular compound (c) is represented by the following general formula (1).

(In Formula (1), R ₁ and R ₂ are each independently CH ₃ (CH ₂ ) _n -CO-OCH ₂ (n is an integer of 12 to 22) or HOCH ₂ , and at least one is CH ₃ ( CH ₂ ) _n -CO-OCH ₃ (n is an integer from 12 to 22).

R ₃ and R ₄ are each independently selected from the group consisting of CH ₃ , C ₂ H ₅ , HOCH ₂ , HOC ₂ H ₄ and HOCH ₂ CH(CH ₃ ).

Here, "δ+" in the general formula (1) indicates that polarity exists in the covalent bond in the molecule, (+) indicates that the electron donating ability of the oxygen atom is strong, and (-) indicates that boron Indicates that the electron-withdrawing property of an atom is strong, "→" indicates a path through which electrons are attracted, and "---" indicates a state in which the bonding force between atoms is weakened.)

[8]

A method for producing the antistatic resin composition according to any one of the above [1] to [7],

Using the block copolymer (b) and the donor/acceptor molecular compound (c), when the total amount of the master batch is 100% by mass, the donor/acceptor molecular compound (c) is 5% by mass or more and 20% by mass A step (I) of producing a masterbatch by melting and kneading at a composition ratio of % or less;

Step (II) of diluting the master batch by kneading the master batch with vinyl aromatic hydrocarbon-based resin (a) and/or block copolymer (b)

Method for producing an antistatic resin composition having.

[9]

An electronic component packaging material, which is a molded article of the antistatic resin composition according to any one of the above [1] to [7].

According to the present invention, even when combined with styrenic resins such as general-purpose polystyrene (GPPS), rubber-modified polystyrene (HIPS), and methyl methacrylate/styrene copolymer resin (MS resin), excellent antistatic performance is exhibited, and An antistatic resin composition excellent in transparency, a manufacturing method of the antistatic resin composition, and an electronic component packaging material can be provided.

Hereinafter, the mode for implementing the present invention (hereinafter referred to as "the present embodiment") will be described in detail.

In addition, the present embodiment below is an example for explaining the present invention, and is not intended to limit the present invention to the following content, and the present invention can be implemented with various modifications within the scope of the gist.

[Antistatic Resin Composition]

(First Antistatic Resin Composition)

The first antistatic resin composition of the present embodiment is an antistatic resin composition containing a block copolymer (b) and a donor/acceptor molecular compound (c).

The block copolymer (b) is a block copolymer containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit, and has a polymer block mainly composed of the vinyl aromatic hydrocarbon monomer unit, and the vinyl aromatic hydrocarbon monomer unit is 30 to 90 mass %, the conjugated diene monomer unit is 70 to 10% by mass.

Further, when the total amount of the block copolymer (b) and the donor/acceptor molecular compound (c) is 100% by mass, the content of the donor/acceptor molecular compound (c) is 0.5% by mass or more and 5% by mass less than %.

By having the above configuration, excellent antistatic performance is exhibited even when combined with styrenic resins such as general-purpose polystyrene (GPPS), rubber-modified polystyrene (HIPS), and methyl methacrylate/styrene copolymer resin (MS resin), In addition, an antistatic resin composition excellent in transparency is obtained.

The first antistatic resin composition of the present embodiment preferably has a surface resistivity of 1×10 ¹² Ω/□ or less.

As a result, excellent antistatic performance can be exhibited.

The surface resistivity of the first antistatic resin composition is preferably 5×10 ¹¹ Ω/□ or less, and more preferably 5×10 ¹⁰ Ω/□ or less.

The surface resistivity of the antistatic resin composition can be measured by the method described in Examples described later.

The surface resistivity of the first antistatic resin composition can be controlled within the above numerical range by mixing an appropriate amount of the donor/acceptor molecular compound (c) in addition to optimizing the polymer structure of the block copolymer (b).

Originally, there is no lower limit of the surface resistivity, and the lower the surface resistivity, the better the performance. However, since the reduction in surface resistivity is proportional to the cost, it is desirable to design the lower limit to 1×10 ⁸ Ω/□ to 1×10 ⁹ Ω/□ in reality.

(Second Antistatic Resin Composition)

The second antistatic resin composition of the present embodiment,

A vinyl aromatic hydrocarbon-based resin (a);

a block copolymer (b);

Donor/acceptor type molecular compound (c)

It is an antistatic resin composition containing.

The block copolymer (b) is a block copolymer containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit, and has a polymer block mainly composed of the vinyl aromatic hydrocarbon monomer unit, and the vinyl aromatic hydrocarbon monomer unit is 30 to 90 mass %, the conjugated diene monomer unit is 70 to 10% by mass.

When the total amount of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100% by mass, the mass ratio of the vinyl aromatic hydrocarbon-based resin (a) is 81% by mass or less, and the block copolymer (b) ) The mass ratio of is 19 mass % or more and less than 100 mass %.

Further, when the total amount of the vinyl aromatic hydrocarbon-based resin (a), the block copolymer (b), and the donor/acceptor molecular compound (c) is 100% by mass, the donor/acceptor molecular compound The content of the compound is 0.5% by mass or more and 5% by mass or less.

Further, the second antistatic resin composition has a surface resistivity of 1×10 ¹² Ω/□ or less.

By having the above configuration, antistatic resin compositions that are various styrenic resin compositions that exhibit excellent antistatic performance and are also excellent in transparency can be obtained.

The surface resistivity of the second antistatic resin composition of the present embodiment is 1×10 ¹² Ω/□ or less.

Thereby, excellent antistatic performance can be exhibited.

The surface resistivity of the second antistatic resin composition is more preferably 5×10 ¹¹ Ω/□ or less, and even more preferably 5×10 ¹⁰ Ω/□ or less.

The surface resistivity of the antistatic resin composition can be measured by the method described in Examples described later.

The surface resistivity of the second antistatic resin composition can be controlled within the above numerical range by blending an appropriate amount of the donor/acceptor molecular compound (c) in addition to optimization of the composition ratio and polymer structure of the block copolymer (b). .

Preferable aspects of the second antistatic resin composition are shown below.

The second antistatic resin composition has a melt flow rate (MFR) of the vinyl aromatic hydrocarbon-based resin (a) under a load condition of 200 ° C. and 5 kg stipulated by ISO1133 (hereinafter referred to as MFRa) It is preferable that the relationship between MFR (hereinafter referred to as MFRb) of the block copolymer (b) satisfies any one of the following conditions (i) to (iv).

<Condition (i)>

When the total of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100% by mass, component (a) is more than 0% by mass and 30% by mass or less, and component (b) is 70% by mass In the case of more than 100% by mass, regardless of the numerical value of MFRa and MFRb, when the sum of the component (a), the component (b) and the component (c) is 100% by mass, the donor/acceptor The system molecular compound (c) is 0.5% by mass or more and 5% by mass or less.

By satisfying the above condition (i), an antistatic resin composition exhibiting excellent antistatic performance and excellent transparency is obtained. In addition, since the composition ratio of the block copolymer (b) is high, the effect of having rich flexibility and excellent impact strength is obtained.

In condition (i), the content of the donor-acceptor type molecular compound (c) is preferably 1 to 5 mass%, more preferably 2 to 4 mass%.

<Condition (ii)>

When the total of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100% by mass, the component (a) is more than 30% by mass and not more than 50% by mass, and the component (b) is 70% by mass In the case of less than 50% by mass or more,

MFRa<MFRb . . . (Equation 1)

In the case of a relationship, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.5% by mass or more and 5% by mass or less,

MFRa≥MFRb . . . (Equation 2)

In the case of a relationship, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.9% by mass or more and 5% by mass or less.

By satisfying the above condition (ii), an antistatic resin composition exhibiting excellent antistatic performance and excellent transparency is obtained. In addition, the effect of further increasing the rigidity of the resin composition is obtained derived from the vinyl aromatic hydrocarbon-based resin (a).

In condition (ii), the content of the donor-acceptor molecular compound (c) is preferably 1 to 5% by mass, more preferably 2 to 4% by mass, when the above (Formula 1) is satisfied. %am.

Further, when the above (Formula 2) is satisfied, it is preferably 2 to 5% by mass, more preferably 2 to 4% by mass.

<Condition (iii)>

When the total of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100% by mass, the component (a) is more than 50% by mass and 70% by mass or less, and the component (b) is 50% by mass In the case of less than 30% by mass or more,

MFRa<MFRb . . . (Equation 1)

is satisfied, and when the sum of the component (a), the component (b), and the component (c) is 100 mass%, the donor/acceptor molecular compound (c) is 0.9 mass% or more It is 5 mass % or less.

By satisfying the above condition (iii), an antistatic resin composition exhibiting excellent antistatic performance and excellent transparency is obtained. In addition, the effect of further increasing the rigidity of the resin composition is obtained derived from the vinyl aromatic hydrocarbon-based resin (a).

In condition (iii), the content of the donor-acceptor molecular compound (c) is preferably 2 to 5% by mass, more preferably 3 to 5% by mass.

<Condition (iv)>

When the total of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100% by mass, the component (a) is more than 70% by mass and 81% by mass or less, and the component (b) is 30% by mass In the case of less than 19% by mass or more,

MFRa<MFRb . . . (Equation 1)

is satisfied, and the content of the donor-acceptor molecular compound (c) is 3% by mass, when the total of the component (a), the component (b), and the component (c) is 100% by mass It is more than 5 mass % or less.

By satisfying the above condition (iv), an antistatic resin composition exhibiting excellent antistatic performance and excellent transparency is obtained. In addition, the effect of increasing the stiffness to a value close to that originally possessed by the vinyl aromatic hydrocarbon-based resin (a) is obtained.

In condition (iv), the content of the donor/acceptor molecular compound (c) is preferably 3.5 to 5% by mass, more preferably 4 to 5% by mass.

In this specification, the naming of each monomer unit constituting the polymer follows the naming of the monomer from which the monomer unit is derived. For example, "vinyl aromatic hydrocarbon monomer unit" means a structural unit of a polymer formed as a result of polymerization of a vinyl aromatic hydrocarbon monomer as a monomer, and its structure is that two carbon atoms of a substituted ethylene group derived from a substituted vinyl group are polymer It is a molecular structure composed of a main chain.

In addition, "conjugated diene monomer unit" means a structural unit of a polymer formed as a result of polymerization of a conjugated diene as a monomer, and its structure is a molecular structure in which two carbons of an olefin derived from a conjugated diene monomer are polymer main chains. .

In this specification, "as a main component" means that the content of a predetermined monomeric unit is 90% by mass or more.

For example, in the block copolymer (b), "a polymer block mainly composed of vinyl aromatic hydrocarbon monomer units" refers to a block in which the vinyl aromatic hydrocarbon monomer units are 90% by mass or more.

A polymer block having less than 90% by mass of vinyl aromatic hydrocarbon monomer units and more than 10% by mass of conjugated diene monomeric units is defined as a random copolymer block.

The random copolymer block may have a completely random structure or a tapered structure (a copolymerization composition ratio changes stepwise along the chain).

(Mass ratio of block copolymer (b) and donor/acceptor molecular compound (c))

The first antistatic resin composition of the present embodiment includes a block copolymer (b) containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit and a donor/acceptor molecular compound (c).

The said block copolymer (b) is 30-90 mass % of vinyl aromatic hydrocarbon monomer units, and 70-10 mass % of conjugated diene monomer units.

When the total of the block copolymer (b) and the donor/acceptor molecular compound (c) is 100 mass%, the content of the donor/acceptor molecular compound (c) is 0.5 mass% or more and 5 mass% less than %.

(Mass ratio of vinyl aromatic hydrocarbon-based resin (a), block copolymer (b), donor/acceptor molecular compound (c))

The mass ratio of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) in the second antistatic resin composition of the present embodiment is vinyl aromatic hydrocarbon-based resin (a)/block copolymer (b) = 0 It is between the amount exceeding less than 100 and less than 81/19 or more.

Within the above mass ratio, depending on the magnitude of the respective MFR values (MFRa and MFRb), depending on the variation in the mass ratio of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b), donors and billions of donors exhibiting performance. The minimum required amount of the scepter-based molecular compound (c) is determined.

Vinyl aromatic hydrocarbon-based resin (a) / block copolymer (b) so that sufficient antistatic performance can be expressed according to the conditions of the respective MFR values of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) according to the mass ratio ) and/or the content of the donor/acceptor molecular compound (c) is set.

In the antistatic resin composition of the present embodiment, the relative comparison value of the mass ratio of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) and the MFR for achieving excellent antistatic performance, that is, antistatic performance, is It is closely related to the minimum required blending amount of the donor/acceptor type molecular compound (c) leading to expression of performance.

For example, even if about 4% by mass of the donor/acceptor molecular compound (c) is blended with the vinyl aromatic hydrocarbon-based resin (a) without using the block copolymer (b), the antistatic performance is not exhibited. In order to express antistatic performance, when the total of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100 parts by mass, the composition in which the content of the block copolymer (b) is at least 19% by mass or more It is necessary to be

Further, when the total of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100% by mass, when the block copolymer (b) is 70% by mass or more, the donor/acceptor molecular compound ( c), since the lowest compounding amount required to develop antistatic performance is 0.5% by mass and does not depend on the MFR value of the vinyl aromatic hydrocarbon-based resin (a) or the block copolymer (b), the range of compositions in which performance can be developed is remarkably widened. all.

For example, antistatic performance is exhibited even when 99.5% by mass of the block copolymer (b) and 0.5% by mass of the donor/acceptor molecular compound (c) are blended without using the vinyl aromatic hydrocarbon resin (a). That is, in order to express antistatic performance in the vinyl aromatic hydrocarbon resin, it is essential that the block copolymer (b) is present in a certain ratio or more, and any interaction leading to the development of antistatic performance is considered.

Hereinafter, the vinyl aromatic hydrocarbon-based resin (a), the block copolymer (b), and the donor/acceptor molecular compound (c), which are constituent components of the antistatic resin composition of the present embodiment, will be described in detail.

(Vinyl aromatic hydrocarbon-based resin (a))

The vinyl aromatic hydrocarbon-based resin (a) is a homopolymer (a1) of a vinyl aromatic hydrocarbon monomer represented by general-purpose polystyrene (GPPS), polybutadiene represented by rubber-modified polystyrene (HIPS), styrene-butadiene rubber, etc. A graft copolymer (a2) obtained by dissolving a rubber in a styrene monomer and carrying out graft polymerization while stirring, and a vinyl aromatic hydrocarbon monomer unit represented by MS resin and (meth)acrylic acid and/or (meth)acrylic acid alkyl ester Any selected from the group consisting of random copolymers (a3) of monomeric units is preferred.

Regarding (a1) and (a2), (a3) has a different dispersion form when mixed with the block copolymer (b) due to the difference in polarity, so the composition range of the antistatic performance expression in the antistatic resin composition is different.

The second antistatic resin composition has a melt flow rate (MFR) of the vinyl aromatic hydrocarbon-based resin (a3) under a load condition of 200 ° C. and 5 kg specified in ISO1133 (hereinafter referred to as MFRa) It is preferable that the relationship between MFR (hereinafter referred to as MFRb) of the block copolymer (b) satisfies the following conditions (v) or (vi).

<Condition (v)>

When the total of the vinyl aromatic hydrocarbon-based resin (a3) and the block copolymer (b) is 100% by mass, the component (a3) is more than 0% by mass and 20% by mass or less, and the component (b) is 80% by mass When it is less than 100% by mass, regardless of the numerical value of MFRa and MFRb, when the sum of the component (a3), the component (b) and the component (c) is 100% by mass, the donor/acceptor The content of the system molecular compound (c) is 0.5% by mass or more and 5% by mass or less.

By satisfying the above condition (v), an antistatic resin composition exhibiting excellent antistatic performance and excellent transparency is obtained. In addition, a resin composition having a low haze value and excellent transparency can be obtained compared to the composition using (a1) or (a2).

In condition (v), the content of the donor/acceptor molecular compound (c) is preferably 1 to 5, more preferably 2 to 4% by mass.

<condition (vi)>

When the total of the vinyl aromatic hydrocarbon-based resin (a3) and the block copolymer (b) is 100% by mass, the component (a3) is more than 20% by mass and 50% by mass or less, and the component (b) is 80% by mass In the case of less than 50% by mass or more,

MFRa<MFRb . . . (Equation 1)

is satisfied, and when the sum of the component (a3), the component (b), and the component (c) is 100% by mass, the component (c) is 3% by mass or more and 5% by mass or less.

By satisfying the above condition (vi), an antistatic resin composition exhibiting excellent antistatic performance and excellent transparency is obtained. In addition, a resin composition having a low haze value and excellent transparency can be obtained compared to the composition using (a1) or (a2).

In condition (vi), the content of the donor-acceptor molecular compound (c) is preferably 3.5 to 5% by mass, more preferably 4 to 5% by mass.

The copolymerization ratio of the vinyl aromatic hydrocarbon monomer unit (S) and the (meth)acrylic acid and/or (meth)acrylic acid alkyl ester monomer unit (M) in the MS resin (a3) is S/M = 83/17 to 60 / 40 (mass %), more preferably S/M = 82/18 to 68/32 (mass %), still more preferably S / M = 82/18 to 78/22 ( mass %).

By using the MS resin of this composition ratio, the refractive index with the block copolymer (b) becomes approximate, and although the dispersion form is not completely compatible, it shows a uniform dispersion form on the order of micrometers, and has excellent transparency and antistatic properties in dynamic properties. A resin composition is obtained.

On the other hand, when the content of the vinyl aromatic hydrocarbon monomer unit of component (a3) is less than 60% by mass, the difference in refractive index from the block copolymer (b) becomes large, the antistatic resin composition tends to become cloudy, and the polarity difference also increases. Therefore, the compatibility is also deteriorated and the mechanical properties of the antistatic resin composition are remarkably deteriorated, which is not preferable.

As long as the antistatic performance is not impaired, the MS resin (a3) may contain other copolymerizable monomeric units as needed.

The vinyl aromatic hydrocarbon monomer constituting the vinyl aromatic hydrocarbon-based resin (a) only needs to have an aromatic ring and a vinyl group in the molecule, and is not particularly limited. For example, styrene, o-methylstyrene, m-methylstyrene, p-methyl Styrene, o-ethyl styrene, p-ethyl styrene, p-tert-butyl styrene, 2,4-dimethyl styrene, 1,3-dimethyl styrene, α-methyl styrene, α-methyl-p-methyl styrene, vinylnaphthalene, Vinyl anthracene, 1, 1-diphenyl ethylene, etc. are mentioned.

You may use these vinyl aromatic hydrocarbon monomers individually by 1 type or in combination of 2 or more types.

Among these, styrene is preferable from the viewpoints of industrial availability and economy.

Among the above vinyl aromatic hydrocarbon-based resins, in particular, the (meth)acrylic acid and/or (meth)acrylic acid and/or (meth)acrylic acid alkyl ester monomer units constituting the random copolymer (a3) of the vinyl aromatic hydrocarbon monomer unit and the (meth)acrylic acid and/or (meth)acrylic acid alkylester monomer unit. The acrylic acid ester monomer means one type or two or more types of monomers selected from the group consisting of acrylic acid, methacrylic acid, acrylic acid alkyl esters and methacrylic acid alkyl esters.

The alkyl ester may be at least one type of ester compound of an alkyl alcohol having 1 to 8 carbon atoms (C1 to C8) and acrylic acid and/or methacrylic acid.

Examples of (meth)acrylic acid and/or (meth)acrylic acid ester monomers are not limited to the following, but examples include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, and n-butyl acrylate (butyl acrylate). , acrylic acid C1-6 alkyl esters such as n-pentyl acrylate and n-hexyl acrylate, cycloalkyl esters of acrylic acid such as cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-methacrylate methacrylic acid C1-6 alkyl esters such as butyl, n-pentyl methacrylate and n-hexyl methacrylate, and cyclohexyl esters of methacrylic acid such as cyclohexyl methacrylate; among these, vinyl aromatic hydrocarbons C1-6 alkyl esters of acrylic acid and C1-6 alkyl methacrylates are preferable from the viewpoint that the softening temperature of the resin (a) can be further increased and, as a result, the moldability and heat deformation resistance of the obtained molded article can be further improved. C1-4 alkyl esters of acrylic acid and C1-4 alkyl methacrylates are more preferred, methyl acrylate and/or methyl methacrylate are more preferred, and methyl methacrylate is still more preferred.

In the present specification, "random copolymer of a vinyl aromatic hydrocarbon monomer unit and (meth)acrylic acid and/or (meth)acrylic acid alkylester monomer unit" (a3) includes a vinyl aromatic hydrocarbon monomer unit, other (meth)acrylic acid and And/or a polymer containing a small amount of other polymerizable monomeric units other than the (meth)acrylic acid alkylester monomeric unit is also included.

The amount of the other monomer units is preferably 2% by mass or less in the vinyl aromatic hydrocarbon-based resin (a).

Also in the case of the "random copolymer of a vinyl aromatic hydrocarbon monomer unit and methyl methacrylate" exemplified as a particularly preferable copolymer, an aspect containing 2% by mass or less of other monomer units is also included in this.

The vinyl aromatic hydrocarbon-based resin (a) can be produced by a known polymerization method.

As a known polymerization method, bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization etc. are mentioned, for example.

When the vinyl aromatic hydrocarbon-based resin (a) is a homopolymer (a1) of a vinyl aromatic hydrocarbon monomer typified by GPPS, for example, styrene monomer is used in the presence of ethylbenzene, in the presence of an organic peroxide, or in the presence of an organic peroxide A styrene homopolymer (GPPS) can be obtained by undergoing radical polymerization using only heat without using the solvent to remove ethylbenzene as a solvent and unreacted styrene monomer.

Further, when the vinyl aromatic hydrocarbon-based resin (a) is a graft copolymer (a2) which is a rubber-modified polystyrene typified by HIPS, for example, polybutadiene is dissolved in a mixture of ethylbenzene and styrene monomer, and the presence of an organic peroxide Then, radical polymerization is carried out while stirring under an appropriate temperature to remove ethylbenzene as a solvent and unreacted styrene monomer, thereby obtaining rubber-modified polystyrene (HIPS).

The molecular weight (Mooney viscosity or solution viscosity) of polybutadiene, the use of styrene-butadiene rubber instead of polybutadiene, or the control of the stirring speed can control the size, occlude shape, and density of graft rubber particles. .

In the case where the vinyl aromatic hydrocarbon resin (a) is a random copolymer (a3) containing (meth)acrylic acid and/or (meth)acrylic acid alkyl ester monomer units typified by MS resin, the vinyl aromatic hydrocarbon monomer and (meth)acrylic acid alkyl ester monomer units ) Under the coexistence of acrylic acid and/or (meth)acrylic acid ester, the production method by radical polymerization similar to the above example is industrially common.

The MFR of the vinyl aromatic hydrocarbon-based resin (a) changes depending on factors such as the degree of polymerization of the monomer unit and the graft rate, but also changes greatly by adding additives such as mineral oil in addition to these factors. The MFR of the vinyl aromatic hydrocarbon-based resin (a) affects the dispersion state of the components (a) and (b), and the dispersion state is an important factor for the expression of antistatic performance of the antistatic resin composition of the present embodiment. am.

The above conditions (i) to (vi) stipulate the MFR value of the component (a) in a state including additives such as mineral oil, and the MFR value expresses the performance of the antistatic resin composition of the present embodiment. directly affect

In the method for producing the vinyl aromatic hydrocarbon-based resin (a), polymerization solvents such as ethylbenzene, radical generators such as organic peroxides, and chain transfer agents such as aliphatic mercaptans may be appropriately used. A specific example is described below.

The polymerization solvent is used to keep the viscosity in the reaction system low during the continuous polymerization process. Examples of the organic solvent include, but are not limited to, alkylbenzenes such as benzene, toluene, ethylbenzene and xylene, and acetone. and ketones such as methyl ethyl ketone, aliphatic hydrocarbons such as hexane and cyclohexane, and the like.

In particular, when a polyfunctional vinyl aromatic hydrocarbon monomer is used as the polymerization monomer, it is preferable to use a polymerization solvent from the viewpoint of suppressing gelation.

By using a polymerization solvent, it becomes difficult to generate a gel, more precise control in the polymerization process becomes possible, and it becomes easier to obtain a vinyl aromatic hydrocarbon-based resin (a) having desired composition and physical properties.

The amount of the polymerization solvent used is not particularly limited, but from the viewpoint of controlling gelation, it is usually preferably 1 to 50% by mass, more preferably 5 to 25% by mass with respect to the entire composition in the polymerization reactor. .

By using 1 to 50% by mass of the polymerization solvent, the vinyl aromatic hydrocarbon-based resin (a) excellent in industrial productivity and economical efficiency can be obtained by suppressing gelation and highly controlling the polymerization process.

In the polymerization step of the vinyl aromatic hydrocarbon-based resin (a), radical agents such as organic peroxides can be preferably used.

Examples of the radical agent include, but are not limited to, 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, and 2,2-di(4). peroxyketals such as 4-di-t-butylperoxycyclohexyl)propane and 1,1-di(t-amylperoxy)cyclohexane; hydroperoxides such as cumene hydroperoxide and t-butyl hydroperoxide; Alkyl peroxides, such as t-butylperoxyacetate and t-amylperoxyisononanoate; dialkyl peroxides such as t-butylcumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, and di-t-hexyl peroxide; Peroxy esters, such as t-butyl peroxy acetate, t-butyl peroxy benzoate, and t-butyl peroxy isopropyl monocarbonate; peroxycarbonates such as t-butyl peroxyisopropyl carbonate and polyether tetrakis (t-butyl peroxycarbonate); N,N'-azobis(cyclohexane-1-carbonitrile), N,N'-azobis(2-methylbutyronitrile), N,N'-azobis(2,4-dimethylvaleronitrile) , N,N'-azobis[2-(hydroxymethyl)propionitrile], etc. are mentioned.

These radical agents can be used individually by 1 type or in combination of 2 or more types.

Further, in the polymerization step of the vinyl aromatic hydrocarbon-based resin (a), a chain transfer agent can be used for the purpose of adjusting the molecular weight of the vinyl aromatic hydrocarbon-based resin (a).

Although it is not limited to the following as a chain transfer agent, For example, aliphatic mercaptan, aromatic mercaptan, pentaphenyl ethane, (alpha)-methylstyrene dimer, terpinolene, etc. are mentioned.

The molecular weight of the vinyl aromatic hydrocarbon-based resin (a) can be controlled by adjusting the concentration of monomers, the amount of radical agents such as organic peroxides, the presence or absence of chain transfer agents, and the amount.

In general, when the amount of radical generation is reduced and the chain transfer agent is not used, the molecular weight is increased, and when the amount of radical generation is increased and the chain transfer agent is added or the amount is increased, the molecular weight is reduced.

As the vinyl aromatic hydrocarbon-based resin (a), it is possible to use commercially available products. For example, GPPS and HIPS include "PSJ-polystyrene" manufactured by PS Japan. GPPS is transparent and HIPS is opalescent, and both products can be suitably used, but note that the tendency of performance expression differs depending on the MFR.

In addition, in the MS resin, "PSJ-Polystyrene SC004" and "PSJ-Polystyrene MM290" manufactured by PS Japan, "Toyo MS MS200" and "Toyo MS MS300" manufactured by Toyo Styrene, "Toyo MS KS10", etc. are mentioned as preferred items. can

All of these have similar refractive indices to the block copolymer (b), are easy to obtain transparent compositions, and show uniform dispersibility on the order of micrometers, although the dispersion form is not completely commercial, and have excellent transparency and antistatic properties in dynamic properties. Since a resin composition is obtained, it can be used preferably.

(block copolymer (b))

The block copolymer (b) is a block copolymer containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit, and the vinyl aromatic hydrocarbon monomer unit is 30 to 90% by mass and the conjugated diene monomer unit is 70 to 10 mass%, It has a polymer block mainly composed of at least one vinyl aromatic hydrocarbon monomer unit.

The polymer block mainly composed of the vinyl aromatic hydrocarbon monomer unit constituting the block copolymer (b) is a polymer block composed of 90% by mass or more of the vinyl aromatic hydrocarbon monomer unit.

In addition, the conjugated diene monomeric unit constituting the block copolymer (b) may be contained as a copolymerization block of a conjugated diene monomeric unit and a vinyl aromatic hydrocarbon monomeric unit other than a conjugated diene polymer block composed of a conjugated diene monomeric unit alone. In the case of the copolymerization block, various copolymerization block structures such as a uniform random structure or a tapered structure (the composition ratio of monomers changes along the chain) can be used.

Further, the block copolymer (b) may be a combination of two or more types of block copolymers having different average molecular weights, or a combination of two or more types of block copolymers having different copolymerization ratios of the vinyl aromatic hydrocarbon monomer unit and the conjugated diene monomer unit. do.

Moreover, the block copolymer (b) may also contain other monomeric units which can be polymerized other than the vinyl aromatic hydrocarbon monomeric unit and the conjugated diene monomeric unit as needed.

The vinyl aromatic hydrocarbon monomer should just have an aromatic ring and a vinyl group in the molecule, and is not limited to the following, and examples thereof include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, and p-ethyl Styrene, p-tert-butylstyrene, 2,4-dimethylstyrene, 1,3-dimethylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, vinylnaphthalene, vinylanthracene and 1,1-diphenylethylene can be heard

These vinyl aromatic hydrocarbon monomers may be used individually by 1 type, or may be used in combination of 2 or more type.

Among these, styrene is preferable from the industrial and economical viewpoints.

The conjugated diene monomer may be a diolefin having a pair of conjugated double bonds, and is not limited to the following, but examples thereof include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), and 2,3- Dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, etc. are mentioned.

These conjugated diene monomers are used individually by 1 type or in combination of 2 or more types.

Among these, 1,3-butadiene and isoprene are preferred from the viewpoints of industrial availability and economic efficiency, and 1,3-butadiene is more preferred from the viewpoint of industrial availability and higher economic efficiency.

The mass ratio of the vinyl aromatic hydrocarbon monomer unit and the conjugated diene monomer unit in the block copolymer (b) is vinyl aromatic hydrocarbon monomer unit/conjugated diene monomer unit = 30/70 to 90/10.

When the ratio of each monomer unit is within the above range, good antistatic properties can be exhibited in the antistatic resin composition of the present embodiment combined with the donor/acceptor molecular compound (c) described later.

In the block copolymer (b), the range of the mass% ratio of the vinyl aromatic hydrocarbon monomer unit/conjugated diene monomer unit is 30/70 to 90/10 as described above.

When the ratio of the vinyl aromatic hydrocarbon monomer units constituting the block copolymer (b) is less than 30% by mass, the modulus of elasticity is very low as a single unit, so an antistatic resin composition using such a block copolymer (b) is used as an electronic component packaging material. In order to use it as a component (a), it is necessary to use a composition mainly containing a vinyl aromatic hydrocarbon-based resin. However, since the ratio of the vinyl aromatic hydrocarbon monomer unit in the block copolymer (b) itself is low, the compatibility with the vinyl aromatic hydrocarbon-based resin, which is the component (a), deteriorates, and as a result, the donor/acceptor molecular compound ( The dispersibility of c) also tends to deteriorate.

In the block copolymer (b), the content of the vinyl aromatic hydrocarbon monomer unit is 30% by mass or more, so that a practically sufficient elastic modulus is ensured, compatibility with the component (a) is good, and component (c) described later An antistatic resin composition having good dispersibility is obtained.

On the other hand, when the ratio of the vinyl aromatic hydrocarbon monomer units constituting the block copolymer (b) exceeds 90% by mass, even when the block copolymer (b) is 100% by mass as the base resin of the antistatic resin composition. , Even if the vinyl aromatic hydrocarbon resin (a) is blended in an arbitrary ratio or 4% by mass of the donor/acceptor molecular compound (c) is blended, the surface resistivity tends to be difficult to decrease.

Content of the vinyl aromatic hydrocarbon monomer unit and the conjugated diene monomer unit in the block copolymer (b) can be quantified by the method described in the Examples described later.

In addition, content of these monomeric units is controllable by adjusting the addition amount and ratio of each monomer in the polymerization process of a block copolymer (b).

Although it does not specifically limit as a block copolymer (b), For example, the block copolymer which has a block structure represented by the following general formula (1) - (7) is mentioned.

In the above general formulas (1) to (7), S1, S2 and S3 respectively represent polymer blocks mainly composed of vinyl aromatic hydrocarbon monomer units, and B1 and B2 respectively represent polymer blocks mainly composed of conjugated diene monomer units (B ), and B/S1 and B/S2 represent random copolymer blocks (B/S) each having a content of a vinyl aromatic hydrocarbon monomer unit and a conjugated diene copolymer unit of less than 90% by mass.

In addition, the numbers attached to S, B, and B / S in the above general formulas (1) to (7) are used to identify a polymer block, a polymer block (B), and a random copolymer block (B / S), respectively. It is a number for each block, and if the number is different, the molecular weight (polymerization degree) or copolymerization ratio of each block may be the same or different. In addition, the chain structure of the random copolymer block (B/S) may be a uniform random block or a tapered block (a composition ratio gradually changed along the chain).

Further, the block copolymer (b) may be either a linear polymer or a branched polymer.

As a method of obtaining a branched polymer, for example, a method of subjecting polymerization terminals to a coupling reaction, a method of branching from the initial stage of polymerization using a polyfunctional initiator, and the like are exemplified.

Further, a suitable application of the antistatic resin composition of the present embodiment is a packaging material for electronic parts. In light of such application, from the viewpoint of various mechanical properties required, the block copolymer (b) is a vinyl aromatic hydrocarbon monomer unit. It has at least one or more polymer blocks S mainly composed of, and preferably has at least two or more polymer blocks S.

In addition, in this specification, a "polymer block mainly composed of a vinyl aromatic hydrocarbon monomer unit" may be described as "polymer block S".

<Peak molecular weight and molecular weight distribution of block copolymer (b)>

The antistatic resin composition of the present embodiment has a peak molecular weight derived from the block copolymer (b) within the range of 30,000 or more and 300,000 or less in the molecular weight distribution curve measured by gel permeation chromatography (GPC measurement method). It is preferable that at least one exists. In this way, the balance between the mechanical properties and molding processability of the antistatic resin composition of the present invention is further improved.

From the same point of view, the peak molecular weight derived from the block copolymer (b) is more preferably within the range of 40,000 or more and 250,000 or less, and more preferably within the range of 50,000 or more and 210,000 or less.

In addition, the peak molecular weight of block copolymer (b) can be measured by the method described in the Example mentioned later.

<Molecular Weight Distribution (Mw/Mn) of Block Copolymer (b)>

The molecular weight distribution (Mw/Mn) of the block copolymer (b) is not particularly limited. A block copolymer (b) having a large molecular weight distribution (Mw/Mn) can be obtained by associating the polymerizable active ends of some polymers with a coupling agent described later or the like to have different molecular weight combinations.

Furthermore, by adding an appropriate amount of alcohol such as ethanol during polymerization to stop the polymerization of a part of the polymer, a block copolymer (b), which is a mixture of different molecular weights, can be obtained. For example, since the polymerization of the polymer can be partially stopped by adding an alcohol such as ethanol in a molar equivalent amount smaller than the number of moles of the polymerization initiator in the polymerization system, the molecular weight distribution having a plurality of peak molecular weights (Mw/Mn ) can obtain a large block copolymer (b).

<Number average molecular weight (Mn) of polymer block S>

The number average molecular weight (Mn) of the polymer block S mainly composed of vinyl aromatic hydrocarbon monomer units in the block copolymer (b) is preferably 10,000 to 60,000, more preferably 15,000 to 50,000, still more preferably is from 20,000 to 40,000.

When the number average molecular weight (Mn) of the polymer block S is within the above range, a molded product (for example, a styrenic resin sheet) having excellent mechanical properties and good molded appearance in a well-balanced manner can be obtained.

The number average molecular weight (Mn) of the polymer block S in the block copolymer (b) is controllable by adjusting the supply amount (feed amount) of the vinyl aromatic hydrocarbon monomer to the polymerization initiator.

The block copolymer (b) contains a polymer block S mainly composed of at least one vinyl aromatic hydrocarbon monomer unit. Preferably, two or more polymer blocks S are included, and at least one polymer block S is more preferably present at the end of the polymer chain. The molecular weight of the polymer block S can control the structure independently of each other even when two or more are included.

In addition, the number average molecular weight (Mn) of the said polymer block S is represented as the number average molecular weight which combined all the polymer blocks S in a block copolymer (b). For example, in the case of the block copolymer (b) of the S1-B/S1-S2 structure, the average molecular weight of the polymer block S is the sum of S1 and S2 and the number average molecular weight.

The number average molecular weight of the polymer block S in the block copolymer (b) is determined by the method of oxidatively decomposing the block copolymer with tert-butyl hydroperoxide using osmium tetraoxide as a catalyst (I. M. KOLTHOFF, et al., J Polym. It can be obtained by measuring using Specifically, it can be measured by the method described in Examples.

<Molecular Weight Distribution of Polymer Block S (Mw/Mn)>

The molecular weight distribution (Mw/Mn) of the polymer block S mainly composed of vinyl aromatic hydrocarbon monomer units in the block copolymer (b) is preferably 1.5 to 4.0, more preferably 1.6 to 3.6, still more preferably 1.7 to 3.2.

When the molecular weight distribution (Mw/Mn) of the polymer block S is within the above range, the molding processability of the antistatic resin composition of the present embodiment and the dispersibility balance between the block copolymer (b) and the vinyl aromatic hydrocarbon-based resin (a) are improved. There is a tendency for a molded article to be obtained that is much better and has a good molding appearance in which defects in molding appearance such as flow during molding are less likely to occur.

The molecular weight distribution (Mw/Mn) of the polymer block S in the block copolymer (b) is the average molecular weight distribution of the entirety of all the polymer blocks S in the block copolymer (b). For example, in the case of the block copolymer (b) of the S1-B/S1-S2 structure, the average molecular weight of the polymer block S is the average molecular weight distribution of S1 and S2. It is controllable by adjusting the supply amount (feed amount) of the vinyl aromatic hydrocarbon monomer to the polymerization initiator, such as bringing the chain lengths of each polymer block S present two or more closer to or apart from each other.

As another method for controlling the molecular weight distribution (Mw/Mn) of the polymer block S in the block copolymer (b), for example, during the polymerization step of the polymer block S, an alcohol such as ethanol in a molar amount smaller than that of the polymerization initiator is added to stop part of the polymerization of the polymer. As a result, the polymer block S becomes a mixture composed of two different molecular weights. In this way, it is possible to control the molecular weight distribution of the polymer block S also by setting it as the block copolymer (b) having the polymer block S having two or more different chain length distributions.

The molecular weight distribution (Mw/Mn) of the polymer block S in the block copolymer (b) can be specifically determined by the method described in Examples described later.

<Method for producing block copolymer (b)>

A known technique can be used for the method for producing the block copolymer (b) constituting the antistatic resin composition of the present embodiment. As a representative prior art, there is a method of block copolymerizing a conjugated diene monomer and a vinyl aromatic hydrocarbon monomer using an anionic polymerization initiator such as an organolithium compound in a hydrocarbon solvent. For example, Japanese Patent Publication No. 36-19286, Japanese Patent Publication 43-17979, Japanese Patent Publication 48-2423, Japanese Patent Publication 49-36957, Japanese Patent Publication 57- It can be manufactured by the method described in Japanese Patent Publication No. 49567 and Japanese Patent Publication No. 58-11446.

The block copolymer (b) is obtained by copolymerizing a vinyl aromatic hydrocarbon monomer and a conjugated diene monomer in a hydrocarbon solvent.

As the hydrocarbon solvent used for producing the block copolymer (b), conventionally known hydrocarbon solvents can be used. Although not limited to the following, For example, Aliphatic hydrocarbons, such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, and n-octane; alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cycloheptane, and methylcycloheptane; Moreover, aromatic hydrocarbons, such as benzene, toluene, xylene, and ethylbenzene, etc. are mentioned.

These hydrocarbon solvents may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, when using an organolithium initiator, n-hexane and cyclohexane are common, and among these, cyclohexane is industrially the most general-purpose and is suitably used.

Although it does not specifically limit as a polymerization initiator, For example, the polymerization initiator which shows anionic polymerization activity with respect to a conjugated diene monomer and a vinyl aromatic hydrocarbon monomer can be used suitably. Specifically, alkali metal compounds, such as an aliphatic hydrocarbon alkali metal compound, an aromatic monomer alkali metal compound, and an organic amino alkali metal compound, are mentioned.

Although it does not specifically limit as an alkali metal used for an alkali metal compound, For example, lithium, sodium, potassium etc. are mentioned.

Examples of suitable alkali metal compounds are, but are not limited to, aliphatic and aromatic hydrocarbon lithium compounds having 1 to 20 carbon atoms and containing one lithium per molecule, and dilithium containing a plurality of lithium per molecule. compounds, trilithium compounds, and tetralithium compounds.

Examples of such an alkali metal compound include, but are not limited to, n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, hexamethylenedilithium, butadienyldilithium, isoprenyldilithium, reaction products of diisopropenylbenzene and sec-butyllithium, further reaction products of divinylbenzene, sec-butyllithium and a small amount of 1,3-butadiene; and the like.

In addition, organic alkali metal compounds disclosed in foreign patents such as US Patent No. 5708092, British Patent No. 2241239, and US Patent No. 5527753 can also be used. These are used individually by 1 type or in combination of 2 or more types. Among these, n-butyllithium is preferable.

As the manufacturing process of the block copolymer (b), the content of the vinyl aromatic hydrocarbon monomer unit and the conjugated diene monomer of the finally obtained block copolymer (b) are adjusted by adjusting the input ratio of the vinyl aromatic hydrocarbon monomer and the conjugated diene monomer as polymerization raw materials. The unit content can be controlled.

In addition, as an option for the production process of the block copolymer (b), for example, a process of additionally adding a polymerization initiator during polymerization, a process of partially coupling reaction by adding a small amount of a polyfunctional monomer having two or more reactive active points Alternatively, a process in which an alcohol, water, etc. less than the polymerization active point is added in the middle of the polymerization, and then the monomer is supplied again to continue the polymerization, etc. can also be suitably employed. By appropriately selecting such a process, a block copolymer (b) in which a plurality of components having different molecular weights are present can be produced.

As a method for producing a copolymer block containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit, a method of continuously supplying a mixture of a vinyl aromatic hydrocarbon monomer and a conjugated diene monomer to a polymerization system for polymerization, a polar compound or a randomizer and methods such as copolymerizing a vinyl aromatic hydrocarbon monomer and a conjugated diene monomer by using.

Examples of the polar compound and randomizer include, but are not limited to, ethers such as tetrahydrofuran, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether; amines such as triethylamine and tetramethylethylenediamine; Thioethers; phosphines; phosphoramides; Alkylbenzene sulfonic acid salts; The alkoxide of potassium or sodium, etc. are mentioned.

Optimal conditions for the polymerization temperature in the polymerization step of the block copolymer (b) vary depending on the polymer structure, but in the case of anionic polymerization using a polymerization initiator, it is generally -10°C to 150°C, preferably 40°C to 40°C. It is in the range of 120 ° C.

In addition, the time required for polymerization is usually within 48 hours, preferably within the range of 1 hour to 10 hours. In addition, it is preferable to replace the atmosphere of the polymerization system with an inert gas such as nitrogen gas. The polymerization pressure may be carried out within a pressure range sufficient to maintain the monomer and polymerization solvent in the liquid layer in the above polymerization temperature range, and is not particularly limited. In addition, it is desirable to take care not to inadvertently introduce impurities such as water, oxygen, carbon dioxide gas, etc. that inactivate the polymerization initiator and living polymer into the polymerization system.

When the block copolymer (b) contains a random copolymer block, a mixture of a vinyl aromatic hydrocarbon monomer and a conjugated diene monomer is continuously supplied to the polymerization system for polymerization, and/or a vinyl aromatic compound or a randomizing agent is used for polymerization. A method such as copolymerizing a hydrocarbon monomer and a conjugated diene monomer can be employed.

In the production of the block copolymer (b), when using an organic alkali metal as a polymerization initiator, when stopping the polymerization reaction, a coupling reaction in which two or more molecules are bonded to stop it can be suitably used. In the coupling reaction, a coupling agent exemplified below can be added to the polymerization system. In addition, by adjusting the addition amount of the coupling agent, only a part of the polymer in the polymerization system is coupled, and the uncoupled polymer and the coupling polymer coexist, thereby obtaining a block copolymer (b) having two or more peaks in the molecular weight distribution. It is also possible to manufacture.

Although it does not specifically limit as a coupling agent which can be used suitably for manufacture of a block copolymer (b), For example, bifunctional or more than arbitrary coupling agents are mentioned.

Specifically, tetraglycidylmethaxylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyl-p-phenylenediamine, tetraglycidyldiaminodiphenylmethane, diglycidyl Dilyaniline, diglycidyl orthotoluidine, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxypropyltri Silane compounds containing amino groups, such as ethoxysilane, (gamma)-glycidoxypropyl tripropoxysilane, and (gamma)-glycidoxypropyl tributoxysilane, are mentioned.

Further, examples of other coupling agents include 1-[3-(triethoxysilyl)-propyl]-4-methylpiperazine and 1-[3-(diethoxyethylsilyl)-propyl]-4-methylpiperazine. Razine, 1-[3-(trimethoxysilyl)-propyl]-3-methylimidazolidine, 1-[3-(diethoxyethylsilyl)-propyl]-3-ethylimidazolidine, 1- [3-(triethoxysilyl)-propyl]-3-methylhexahydropyrimidine, 1-[3-(dimethoxymethylsilyl)-propyl]-3-methylhexahydropyrimidine, 3-[3-( Tributoxysilyl)-propyl]-1-methyl-1,2,3,4-tetrahydropyrimidine, 3-[3-(dimethoxymethylsilyl)-propyl]-1-ethyl-1,2,3 ,4-Tetrahydropyrimidine, 1-(2-ethoxyethyl)-3-[3-(trimethoxysilyl)-propyl]-imidazolidine, (2-{3-[3-(trimethoxysilyl)-propyl] and silane compounds containing a silyl group such as oxysilyl)-propyl]-tetrahydropyrimidin-1-yl}-ethyl)dimethylamine.

In addition, as other coupling agents, for example, γ-glycidoxypropyltriphenoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyl Diethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropyldimethylmethoxysilane, γ-glycidoxypropyldiethylethoxysilane, γ-glycidoxypropyldimethylethoxysilane, γ-glycidoxypropyldimethylphenoxysilane, γ-glycidoxy Propyldiethylmethoxysilane, γ-glycidoxypropylmethyldiisopropenoxysilane, bis(γ-glycidoxypropyl)dimethoxysilane, bis(γ-glycidoxypropyl)diethoxysilane, bis(γ -glycidoxypropyl)dipropoxysilane, bis(γ-glycidoxypropyl)dibutoxysilane, bis(γ-glycidoxypropyl)diphenoxysilane, bis(γ-glycidoxypropyl)methylmethoxy Silane, bis(γ-glycidoxypropyl)methylethoxysilane, bis(γ-glycidoxypropyl)methylpropoxysilane, bis(γ-glycidoxypropyl)methylbutoxysilane, bis(γ-glycyl and silane compounds containing glycidoxy groups such as doxypropyl)methylphenoxysilane and tris(γ-glycidoxypropyl)methoxysilane.

In addition, as other coupling agents, for example, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-methacryloxyethyltri and silane compounds containing a methacryloxy group such as ethoxysilane, bis(γ-methacryloxypropyl)dimethoxysilane, and tris(γ-methacryloxypropyl)methoxysilane.

In addition, as another coupling agent, for example, β-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-triethoxysilane, β-(3 ,4-epoxycyclohexyl)ethyl-tripropoxysilane, β-(3,4-epoxycyclohexyl)ethyl-tributoxysilane, β-(3,4-epoxycyclohexyl)ethyl-triphenoxysilane, β-(3,4-epoxycyclohexyl)propyl-trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-methyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-ethyl Dimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-ethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-methyldiethoxysilane, β-(3,4-epoxycyclohexyl) ) Ethyl-methyldipropoxysilane, β-(3,4-epoxycyclohexyl)ethyl-methyldibutoxysilane, β-(3,4-epoxycyclohexyl)ethyl-methyldiphenoxysilane, β-(3 ,4-epoxycyclohexyl)ethyl-dimethylmethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-diethylethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-dimethylethoxysilane , β-(3,4-epoxycyclohexyl)ethyl-dimethylpropoxysilane, β-(3,4-epoxycyclohexyl)ethyl-dimethylbutoxysilane, β-(3,4-epoxycyclohexyl)ethyl- Epoxycyclohexyl groups such as dimethylphenoxysilane, β-(3,4-epoxycyclohexyl)ethyl-diethylmethoxysilane, and β-(3,4-epoxycyclohexyl)ethyl-methyldiisopropenoxysilane. A silane compound containing Examples of other coupling agents include 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N,N'-dimethylpropylene urea, and N-methylpyrrolidone. there is.

In the case where the coupling agent is subjected to an addition reaction to the living end of the block copolymer (b), the structure of the living end of the block copolymer (b) is not limited at all, but the mechanical properties of the antistatic resin composition of the present embodiment From the standpoint of strength and the like, it is preferably a living end of a block mainly composed of a vinyl aromatic hydrocarbon monomer.

The amount of coupling agent used is preferably 0.1 equivalent or more and 10 equivalent or less, more preferably 0.5 equivalent or more and 4 equivalent or less, relative to 1 equivalent of the living end of the block copolymer (b). A coupling agent can be used individually by 1 type or in combination of arbitrary 2 or more types.

(Donor-acceptor molecular compound (c))

The antistatic resin composition of the present embodiment contains a donor/acceptor compound (c).

The donor-acceptor molecular compound (c) is a molecular compound having both a donor and an acceptor. A donor here means an electron-donating group, and an acceptor means an electron-withdrawing group.

Specifically, the donor/acceptor molecular compound (c) comprises an organoboron compound represented on the upper end side of the following general formula (1) as the donor component and the lower side of the following general formula (1) as the acceptor component. It is preferable that each of the organic nitrogen compounds shown in is a compound obtained by mixing.

In the above general formula (1), R ₁ and R ₂ are each independently CH ₃ (CH ₂ ) _n -CO-OCH ₂ (n is an integer of 12 to 22) or HOCH ₂ , and at least one is CH ₃ (CH ₂ ) _n -CO-OCH ₃ (n is an integer from 12 to 22).

R ₃ and R ₄ are each independently selected from the group consisting of CH ₃ , C ₂ H ₅ , HOCH ₂ , HOC ₂ H ₄ and HOCH ₂ CH(CH ₃ ).

Here, "δ+" in the general formula (1) indicates that polarity exists in the covalent bond in the molecule, (+) indicates that the electron donating ability of the oxygen atom is strong, and (-) indicates that boron The electron-withdrawing property of an atom is strong, "→" represents a path through which electrons are attracted, and "---" represents a state in which the bonding force between atoms is weakened.

The donor component composed of the organoboron compound moiety appearing on the upper end side of the general formula (1) has at least one straight-chain hydrocarbon group having 12 to 22 carbon atoms, and the organic boron compound appearing on the lower end side of the general formula (1) In the acceptor component consisting of a nitrogen compound moiety, one of the N-substituents is a group in which a straight-chain hydrocarbon group having 12 to 22 carbon atoms is terminally bonded through an amide bond, and the other two N-substituents are hydrocarbon groups having 1 to 3 carbon atoms or It is a tertiary amine that is a hydroxyhydrocarbon group.

A plurality of donor-acceptor molecular compounds are manufactured and sold by Boron Research Institute, Inc., and the trade name "Biomicell BN-105" in particular is a representative example thereof.

The donor/acceptor molecular compound (c) used in the antistatic resin composition of the present embodiment has an antistatic effect and exhibits antistatic properties by being added to resin to form a composition.

The expression of antistatic properties by the donor-acceptor molecular compound (c) is affected by the polymer species of the resin composition to be blended, the composition ratio, the melt viscosity of each component, and the like.

From the viewpoint of expression of antistatic performance, the appropriate composition range of the donor/acceptor molecular compound (c), particularly its lower limit, is determined by the mass ratio of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) and the MFR of each component. change to value

That is, the antistatic resin composition of the present embodiment satisfies any one of the following conditions (i) to (iv).

<Condition (i)>

When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 0% by mass and 30% by mass or less, and the component (b) is 70% by mass or more and 100% by mass If less than

Regardless of the numerical value of MFRa and MFRb, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.5% by mass or more and 5% by mass less than %.

<Condition (ii)>

When the total of the component (a) and the component (b) is 100% by mass, the component (a) is greater than 30% by mass and not more than 50% by mass, and the component (b) is less than 70% by mass 50% by mass If more than

MFRa<MFRb . . . (Equation 1)

In the case of a relationship, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.5% by mass or more and 5% by mass or less,

MFRa≥MFRb . . . (Equation 2)

In the case of a relationship, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.9% by mass or more and 5% by mass or less.

<Condition (iii)>

When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 50% by mass and 70% by mass or less, and the component (b) is less than 50% by mass and 30% by mass If more than

MFRa<MFRb . . . (Equation 1)

The relationship of is satisfied, and when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.9% by mass or more and 5% by mass or less.

<Condition (iv)>

When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 70% by mass and 81% by mass or less, and the component (b) is less than 30% by mass and 19% by mass If more than

MFRa<MFRb . . . (Equation 1)

The relationship of is satisfied, and when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 4% by mass or more and 5% by mass or less.

As the composition ratio of the block copolymer (b) increases in this way, the MFR value (MFRb) of the block copolymer (b) is higher than the MFR value (MFRa) of the vinyl aromatic hydrocarbon-based resin (a). A decrease in surface resistivity is observed with the added amount of the donor/acceptor molecular compound (c), and there is a tendency for the antistatic performance to be easily expressed.

(Other additives that can be incorporated into the antistatic resin composition)

The antistatic resin composition of this embodiment may also contain arbitrary additives within the range which does not impair the effect of this embodiment.

Examples of additives include those generally used for formulation of resins and rubbery polymers, and include, but are not limited to, inorganic fillers such as calcium carbonate, magnesium carbonate, silica, zinc oxide, and carbon black; fatty acid metal salts such as higher alcohols such as stearyl alcohol, fatty acids such as palmitic acid, stearic acid, and behenic acid, zinc stearate, calcium stearate, magnesium stearate, magnesium behenate, and hydrogenated magnesium ricinoleate; lubricants and release agents such as fatty acid amides such as erucic acid amide and ethylenebisstearylamide; softeners and plasticizers such as paraffin oil, process oil, organopolysiloxane, and mineral oil; Hindered phenol-based, phosphorus-based heat stabilizers and antioxidants: hindered amine-based light stabilizers; Benzotriazole-based UV absorbers: flame retardants; reinforcing agents such as organic fibers, glass fibers, carbon fibers, and metal whiskers; and coloring agents such as organic pigments, inorganic pigments, and organic dyes.

[Method for Producing Antistatic Resin Composition]

The method for producing the antistatic resin composition of the present embodiment is not particularly limited. For example, a block copolymer (b) and a donor/acceptor molecular compound (c) or a vinyl aromatic hydrocarbon-based resin (a) are added to the block copolymer (b). After adding and dry blending at room temperature, heat-melting and kneading in a twin-screw extruder, extruding the heat-melted antistatic resin composition from a die into strands, and pelletizing again through a cooling bath to obtain a pellet-like composition. there is.

In the case of heat-melting kneading, there is no particular limitation as long as it is a kneading machine for a thermoplastic resin capable of being heated and melted. there is.

In addition, not only a strand cutting method using a cooling bath, but also a hot cutting method, an under water cutting method, and the like can be suitably used depending on the purpose.

In order to sufficiently exhibit the antistatic performance of the donor/acceptor molecular compound (c), it is preferable to prepare the antistatic resin composition by the following manufacturing method.

That is, the block copolymer (b) and the donor/acceptor molecular compound (c) are melt-kneaded so that the composition ratio of the donor/acceptor molecular compound (c) is 5% by mass or more and 20% by mass or less, ( c) Process (I) of producing a master batch having a high component concentration, and a process of kneading the master batch, vinyl aromatic hydrocarbon-based resin (a) and/or block copolymer (b), and diluting the master batch ( Through II), the antistatic resin composition of this embodiment is obtained.

By adopting the manufacturing method via the master batch, the dispersibility of the donor/acceptor molecular compound (c) in the antistatic resin composition is remarkably improved, and the desired reduced surface resistivity can be efficiently expressed with a smaller addition amount. Thus, the balance between the mechanical properties and antistatic performance of the resulting antistatic resin composition becomes optimal.

In the antistatic resin composition of the present embodiment, the donor/acceptor molecular compound (c) is contained in a resin matrix containing the component (b) or in a resin matrix containing the component (a) and the component (b). Sufficient dispersion using a kneader is important for performance development, and a production method of obtaining a desired antistatic resin composition by diluting it after once preparing a high-concentration master batch is recommended.

[Electronic parts packaging material]

The molded article of the antistatic resin composition of the present embodiment is suitable as an electronic component packaging material.

As an electronic component packaging material, a carrier tape, a conveyance tray, a magazine tube etc. are mentioned, for example.

The electronic component packaging material of the present embodiment may be a single layer or a multi-layer structure in the thickness direction. However, from an economical point of view, the electronic component packaging material of the present embodiment contains the antistatic resin composition of the present embodiment as the surface layer or It is common to use it limited to the front and back layers.

Forming a multi-layer sheet in which a layer containing the antistatic resin composition of the present embodiment is provided with several tens of μm is performed on the surface layer portion on the side in contact with the electronic component product, and then the electronic component product is housed through vacuum molding or compression molding. A recess (also referred to as a pocket or embossing) is formed. Since the electronic component packaging material used in a single layer such as a conveyance tray is also in contact with the electronic component product on its back side, the electronic component packaging material provided with the antistatic resin composition of the present embodiment not only in the surface layer but also in the second layer is used. is common and desirable.

In the antistatic resin composition of the present embodiment, even if the donor/acceptor molecular compound (c) is added, the transparency of the base resin containing component (a) and component (b) is not significantly impaired.

By selecting the combination of component (a) and component (b) to be used, an electronic component packaging material having good transparency can be obtained.

The electronic component packaging material of the present embodiment is not particularly limited in its thickness or the thickness of each layer that constitutes it, and is appropriately designed depending on the case depending on the electronic component that is the target of the packaging material.

When the electronic component packaging material of the present embodiment is an extrusion molded product, the overall thickness is preferably 50 µm to 4 mm, more preferably 0.1 mm to 2.0 mm, still more preferably 0.1 mm to 1.5 mm, and still more preferably. Preferably, it is 0.2 mm to 1.2 mm. If the final use is a carrier tape, it tends to be thin, while if it is a conveyance tray, it tends to be thick.

The thickness of the layer containing the antistatic resin composition in contact with the electronic part product is preferably 5 µm to 1 mm, more preferably 10 µm to 0.1 mm, still more preferably 15 µm to 50 µm. When secondary processing such as vacuum molding or compression molding is performed from the raw sheet, there are places such as the embossed side surface that are stretched and become thinner, so that the raw sheet has a certain amount of layer thickness containing the antistatic resin composition. It is preferable to put

For the purpose of in-process recycling, the electronic component packaging material of the present embodiment may be used by blending pulverized scrap material of the sheet into at least one layer of the intermediate layer. In that case, a method of blending a new material and a recycled material in an arbitrary ratio is common, but the recycled material may be used alone. The recycled material is preferably of a similar composition generated from the same line, but within a range that does not impair the action and effect of the present embodiment, you may blend different resin compositions generated from different series.

Further, the surface of the electronic component packaging material of the present embodiment may be subjected to surface treatment such as printing, electrical discharge treatment such as corona discharge or glow discharge, acid treatment, or the like, within a range not departing from the spirit of the present invention.

[Characteristics of electronic parts packaging materials]

(surface resistivity)

The surface resistivity of the antistatic resin composition and the electronic part packaging material obtained by molding from the antistatic resin composition is 1×10 ¹² Ω/□ or less.

The surface resistivity of a molded product or a resin composition comprising only component (a) and component (b) without blending donor/acceptor molecular compound (c) is generally an insulator that exhibits 1×10 ¹⁶ Ω/□ or more. The fact that the surface resistivity can be 1×10 ¹² Ω/□ or less is the effect of blending the donor/acceptor molecular compound (c).

However, it is difficult to bring out the performance even if the donor/acceptor molecular compound (c) is blended with the vinyl aromatic hydrocarbon-based resin alone as component (a), and the existence of a block copolymer as component (b) is indispensable. .

The surface resistivity of an electronic component packaging material is determined only by the resin composition of the surface portion in contact with the electronic component, without depending on the molding method or product shape.

Therefore, the surface resistivity of the packaging material for electronic parts has the same value as the surface resistivity of the antistatic resin composition in direct contact with the electronic parts, and is compatible.

The surface resistivity can be measured by the method described in Examples, and can be measured using, for example, Simco Japan Co., Ltd. simple surface resistivity meter "ST-3". It is preferable to measure the sample after molding it into a sheet shape and leaving it still (for example, for 24 hours) in a constant temperature room at 23°C and 50% humidity. The surface resistivity of the extruded sheet sample can be an average value of values measured in the extrusion direction (MD) and the extrusion vertical direction (TD) on the front and back surfaces, respectively.

(Haze value)

The antistatic resin composition and the packaging material for electronic parts of the present embodiment may have better visibility depending on the type of parts to be packaged, etc., and having transparency broadens the range of applicable uses. For example, there are not many cases where visibility is required in transport tray applications, on the other hand, there are many cases where visibility is required in carrier tape applications, and it is preferable to have transparency.

Transparency shown in the examples is based on ISO14782 and is expressed as a haze value measured using a 1 mm thick flat plate produced by injection molding of an antistatic resin composition.

The range of the haze value that has visibility (the electronic parts of the contents are visible through the packaging material) is 20% or less, and the smaller the haze value and closer to zero, the better the visibility. When the content is clearly visible, the haze value is 4.0% or less, and when the haze value is 2.0% or less, even the outline of the content is clearly visible.

In order to improve the transparency by reducing the haze value of the antistatic resin composition of the present embodiment, each component alone of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) has transparency, and the vinyl aromatic It is necessary that the refractive indices of the hydrocarbon-based resin (a) and the block copolymer (b) are approximated. Specifically, when the difference in refractive index is 0.004 or less, transparency becomes good, and a haze value of 4.0% or less can be achieved.

As for the haze value of the antistatic resin composition of the present embodiment, a value measured on an injection plate is used as described above, but actual packaging materials for electronic parts are often molded by extrusion molding, and dispersion derived from the higher order structure of the resin composition. Depending on the shape, the roll temperature, the clearance between the rolls, or the finished state such as the mirror surface of the roll surface, the extruded surface changes, and the haze value also changes. In addition, in the case of a multilayer molded sheet including a surface layer and an intermediate layer, the transparency of each layer affects the transparency of the electronic component packaging material itself.

<Example>

Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples.

In addition, this embodiment is not limited at all by the following examples.

(Vinyl aromatic hydrocarbon-based resin (a) and donor/acceptor molecular compound (c) used in Examples and Comparative Examples)

As the vinyl aromatic hydrocarbon-based resins (a)-1 to (a)-8 and the donor/acceptor molecular compound (c-1), commercially available ones were obtained and used.

In the following [Table 1], in addition to these manufacturers, product names, and types, the MFR value (described as MFRa in Table 1) is also added for the component (a), and a list is shown.

(Melt flow rate (MFRa) of vinyl aromatic hydrocarbon resin (a))

(a) For the MFR of the component, a value published as a physical property table was used.

The measurement standard was based on ISO1133 and was measured at a temperature of 200°C and a load of 5 kgf. It was set as the same standard and the same conditions as MFRb of block copolymer (b) mentioned later.

(block copolymer (b))

[Production Examples 1 to 8]

As for the block copolymer (b), block copolymers (b)-1 to (b)-8 were prepared according to the following Production Examples.

[Production Example 1]

In a nitrogen gas atmosphere, 0.08 parts by mass of n-butyllithium and 0.015 parts by mass of tetramethylmethylenediamine were added to a cyclohexane solution containing 20 parts by mass of styrene at a concentration of 25% by mass, followed by polymerization at 80°C for 20 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 14 parts by mass of 1,3-butadiene and 10 parts by mass of styrene at a concentration of 25% by mass to the polymerization solution over 30 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 16 parts by mass of 1,3-butadiene and 10 parts by mass of styrene at a concentration of 25% by mass to the polymerization solution over 30 minutes.

Next, a cyclohexane solution containing 30 parts by mass of styrene at a concentration of 25% by mass was added to the polymerization solution, followed by polymerization at 80°C for 30 minutes.

Thereafter, in order to completely stop polymerization, ethanol was added in an equimolar mole to n-butyllithium in the reactor, and 2-t-butyl-6(3-t-butyl-6(3-t-butyl- Block copolymer (b)-1 was recovered by adding 0.4 parts by mass of 2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and then removing the solvent.

[Production Example 2]

In a nitrogen gas atmosphere, 0.08 parts by mass of n-butyllithium was added to a cyclohexane solution containing 31 parts by mass of styrene at a concentration of 25% by mass, followed by polymerization at 80°C for 20 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 21 parts by mass of 1,3-butadiene and 20 parts by mass of styrene at a concentration of 25% by mass to the polymerization solution over 30 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 2 parts by mass of 1,3-butadiene and 6 parts by mass of styrene at a concentration of 25% by mass to the polymerization solution over 30 minutes. Next, a cyclohexane solution containing 20 parts by mass of styrene at a concentration of 25% by mass was added to the polymerization solution, followed by polymerization at 80°C for 30 minutes.

Thereafter, in order to completely stop polymerization, ethanol was added in an equimolar mole to n-butyllithium in the reactor, and 2-t-butyl-6(3-t-butyl-6(3-t-butyl- Block copolymer (b)-2 was recovered by adding 0.3 parts by mass of 2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and then removing the solvent.

[Production Example 3]

In a nitrogen gas atmosphere, 0.08 parts by mass of n-butyllithium was added to a cyclohexane solution containing 8 parts by mass of butadiene at a concentration of 25% by mass, followed by polymerization at 80°C for 20 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 14 parts by mass of styrene at a concentration of 25% by mass to the polymerization solution over 15 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 22 parts by mass of 1,3-butadiene at a concentration of 25% by mass to the polymerization solution over 15 minutes.

Next, a cyclohexane solution containing 29 parts by mass of styrene at a concentration of 25% by mass was added to the polymerization solution, followed by polymerization at 80°C for 30 minutes.

After that, in order to stop part of the polymerization, ethanol was added in a molar amount of 0.5 times the amount of n-butyllithium in the reactor, and the polymerization solution was stirred for 10 minutes, and then 27 parts by mass of styrene was included in the polymerization solution at a concentration of 25% by mass A cyclohexane solution was added and polymerization was performed at 80° C. for 30 minutes.

Thereafter, in order to completely stop the polymerization, ethanol was added in an amount of 0.5 molar to n-butyllithium in the reactor, and 2-t-butyl-6(3-t-butyl as a heat stabilizer with respect to 100 parts by mass of the block copolymer). Block copolymer (b)-3 was recovered by adding 0.4 parts by mass of -2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and then removing the solvent.

[Production Example 4]

In a nitrogen gas atmosphere, 0.08 parts by mass of n-butyllithium and 0.015 parts by mass of tetramethylmethylenediamine were added to a cyclohexane solution containing 60 parts by mass of styrene at a concentration of 25% by mass, followed by polymerization at 80°C for 20 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 30 parts by mass of 1,3-butadiene and 10 parts by mass of styrene at a concentration of 25% by mass to the polymerization solution over 30 minutes.

Thereafter, in order to completely stop polymerization, ethanol was added in an equimolar mole to n-butyllithium in the reactor, and 2-t-butyl-6(3-t-butyl-6(3-t-butyl- Block copolymer (b)-4 was recovered by adding 0.3 parts by mass of 2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and then removing the solvent.

[Production Example 5]

In a nitrogen gas atmosphere, 0.08 parts by mass of n-butyllithium and 0.015 parts by mass of tetramethylmethylenediamine were added to a cyclohexane solution containing 40 parts by mass of styrene at a concentration of 25% by mass, followed by polymerization at 80°C for 20 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 15 parts by mass of 1,3-butadiene and 10 parts by mass of styrene at a concentration of 25% by mass to the polymerization solution over 30 minutes.

Next, a cyclohexane solution containing 35 parts by mass of styrene at a concentration of 25% by mass was added to the polymerization solution, followed by polymerization at 80°C for 30 minutes.

Thereafter, in order to completely stop polymerization, ethanol was added in an equimolar mole to n-butyllithium in the reactor, and 2-t-butyl-6(3-t-butyl-6(3-t-butyl- Block copolymer (b)-5 was recovered by adding 0.2 parts by mass of 2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and then removing the solvent.

[Production Example 6]

In a nitrogen gas atmosphere, 0.08 parts by mass of n-butyllithium was added to a cyclohexane solution containing 42 parts by mass of styrene at a concentration of 25% by mass, followed by polymerization at 80°C for 20 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 8 parts by mass of 1,3-butadiene at a concentration of 25% by mass to the polymerization solution over 10 minutes. Next, a cyclohexane solution containing 50 parts by mass of styrene at a concentration of 25% by mass was added to the polymerization solution, followed by polymerization at 80°C for 30 minutes.

Thereafter, in order to completely stop polymerization, ethanol was added in an equimolar mole to n-butyllithium in the reactor, and 2-t-butyl-6(3-t-butyl-6(3-t-butyl- Block copolymer (b)-6 was recovered by adding 0.2 parts by mass of 2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and then removing the solvent.

[Production Example 7]

In a nitrogen gas atmosphere, 0.08 parts by mass of n-butyllithium was added to a cyclohexane solution containing 16 parts by mass of styrene at a concentration of 25% by mass, followed by polymerization at 80°C for 20 minutes.

Next, a cyclohexane solution containing 68 parts by mass of 1,3-butadiene at a concentration of 25% by mass was added to the polymerization solution over 10 minutes, followed by polymerization at 80°C.

Next, a cyclohexane solution containing 16 parts by mass of styrene at a concentration of 25% by mass was added to the polymerization solution, followed by polymerization at 80°C for 30 minutes.

Thereafter, in order to completely stop polymerization, ethanol was added in an equimolar mole to n-butyllithium in the reactor, and 2-t-butyl-6(3-t-butyl-6(3-t-butyl- Block copolymer (b)-7 was recovered by adding 0.5 parts by mass of 2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and then removing the solvent.

[Production Example 8]

In a nitrogen gas atmosphere, 0.08 parts by mass of n-butyllithium was added to a cyclohexane solution containing 9 parts by mass of styrene at a concentration of 25% by mass, followed by polymerization at 80°C for 15 minutes.

Next, polymerization was carried out at 80°C while continuously adding a cyclohexane solution containing 75 parts by mass of 1,3-butadiene and 7 parts by mass of styrene at a concentration of 25% by mass to the polymerization solution over 30 minutes.

Next, a cyclohexane solution containing 9 parts by mass of styrene at a concentration of 25% by mass was added to the polymerization solution, followed by polymerization at 80°C for 30 minutes.

Thereafter, in order to completely stop polymerization, ethanol was added in an equimolar mole to n-butyllithium in the reactor, and 2-t-butyl-6(3-t-butyl-6(3-t-butyl- Block copolymer (b)-8 was recovered by adding 0.5 parts by mass of 2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and then removing the solvent.

(Contents of vinyl aromatic hydrocarbon monomer units (styrene units) and conjugated diene monomer units (butadiene units) of each block copolymer (b)-1 to (b)-8)

For each block copolymer obtained in Production Examples 1 to 8, the copolymerization ratio of styrene and 1,3-butadiene, each monomer component, is analyzed by the analysis method shown below to confirm that there is no difference from the addition ratio during polymerization. did As an analysis instrument, an ultraviolet and visible spectrophotometer manufactured by Shimadzu Corporation was used.

Specifically, about 30 mg (accurately weighed to the nearest 0.1 mg unit) of each block copolymer (b)-1 to (b)-8 was dissolved in 100 mL of chloroform, and the polymer solution was filled in a quartz cell and set in an ultraviolet and visible spectrophotometer. and irradiated with ultraviolet wavelengths of 260 to 290 nm. Styrene composition ratio ( mass%) was obtained. The peak wavelength originating from styrene appears at 269.2 nm.

As a result, it was confirmed that there was no difference between the styrene input ratio during polymerization and the styrene composition ratio in the block copolymer. On the other hand, the butadiene composition ratio (mass %) is obtained by subtracting the styrene composition ratio (mass %) from 100.

(Weight average molecular weight Mw, number average molecular weight Mn, molecular weight distribution Mw/Mn, peak molecular weight and molecular weight peak number of each block copolymer (b)-1 to (b)-8)

The weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw/Mn), peak molecular weight and molecular weight peak number of the block copolymers (b)-1 to (b)-8 were determined by gel permeation chromatography, respectively. It was measured according to the following measurement conditions with the graphography (GPC) apparatus.

(Measuring conditions)

GPC device: HLC-8220 manufactured by Tosoh Corporation

Column: Two SuperMultiporeHZ-M manufactured by Tosoh Corporation are connected in series.

Column temperature: 40°C

Transfer amount: 0.2mL/min

Detector: Refractometer (RI)

Further, using tetrahydrofuran as a solvent, about 10 mg of the polymer of interest for molecular weight measurement was dissolved in 20 mL of tetrahydrofuran, filtered to remove insoluble matter, and a sample for GPC measurement was obtained.

A specific measurement method is described below. First, a calibration curve was prepared using 9 standard polystyrene samples of known molecular weights having different molecular weights. The weight average molecular weight (Mw) of standard polystyrene having the highest molecular weight was 1090000, and that having the lowest molecular weight was 1050. Subsequently, samples for measurement were prepared in the manner described above using each block polymer whose molecular weight was to be measured.

After confirming that the temperature in the tank in which the column was stored became constant, a sample of the solution was injected and measurement was started. After completion of the measurement, the obtained molecular weight distribution curve was subjected to statistical processing to calculate the weight average molecular weight (Mw) and number average molecular weight (Mn). The molecular weight distribution (Mw/Mn) was obtained by dividing the obtained weight average molecular weight (Mw) by the number average molecular weight (Mn). In addition, the peak molecular weight and the number of molecular weight peaks were judged from the above molecular weight distribution curve.

(Weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) of polymer block S of each block copolymer (b)-1 to (b)-8))

Next, the molecular weight of the polymer block S composed only of the vinyl aromatic monomer units constituting each of the block copolymers (b)-1 to (b)-8 was measured.

Specifically, after dissolving about 20 mg of the polymer in about 10 mL of chloroform using an Erlenmeyer flask, 20 mL of an osmic acid solution was added and the mixture was heated in hot water at about 90°C for 30 minutes to decompose the conjugated diene portion.

After boiling water, the Erlenmeyer flask was cooled with running water, and about 200 mL of methanol was lightly injected into the polymer solution after decomposition to precipitate components that did not dissolve in the solvent.

This precipitated solid component is a polymer block S composed only of vinyl aromatic monomer units, and styrene monomers that do not form blocks and styrene with a low polymerization degree remain dissolved in the mixed solution of methanol / tert-butyl alcohol / chloroform. This precipitate was suction filtered using a glass filter, washed with pure methanol and vacuum dried to isolate only the polymer block S from the block copolymer (b).

Here, the above-mentioned osmic acid solution is a tert- It is a solution obtained by dissolving and mixing with 3 L of butyl alcohol.

About 10 mg of the polymer block S thus obtained was dissolved again in 20 mL of tetrahydrofuran and measured by a GPC device. The measurement conditions and method were performed in accordance with the measurement conditions and method for the molecular weight of the block copolymer (b) described above.

(Melt flow rate (MFRb) of block copolymer (b))

Based on standard ISO1133, the measurement was performed under conditions of a temperature of 200°C and a load of 5 kgf.

Monomer feed composition at the time of each production of the block copolymers (b)-1 to (b)-8 obtained by each Production Example 1 to 8, and the ratio of the vinyl aromatic monomer unit and the conjugated diene monomer unit (% by mass) , molecular weight information and melt flow rate based on the GPC measurement results are shown in [Table 2] below.

[Method for Producing Antistatic Resin Composition]

The vinyl aromatic hydrocarbon-based resins (a)-1 to (a)-7 and the donor/acceptor molecular compound (c-1) shown in [Table 1], and the block copolymers shown in [Production Examples 1 to 8] above Antistatic resin compositions were prepared using the compounds (b)-1 to (b)-8 by the method described below.

First, component (a), component (b), and component (c) were dry blended at room temperature in a desired composition ratio. Then, it injected|threw-in into the hopper of Nippon Sekosho twin-screw extruder TEX30(L/D=42), and melt-kneaded at the cylinder temperature of 210 degreeC.

In addition, only in the case of the blending composition using (a)-5, it was carried out at a cylinder temperature of 230 ° C.

In order to fully exhibit the antistatic performance of the component (c), it is necessary to highly finely disperse the component (c) in the component (b), and when via the production of a high-concentration master batch (Examples 35 to 44 ), or in the case of directly producing an antistatic resin composition without going through the production of a high-concentration master batch (Examples 1 to 34 and Comparative Examples 1 to 24), at the time of the first processing from each single component, that is, the configuration In the melt-kneading step of the components, a kneading machine having high kneading properties, specifically a twin-screw extruder, was used.

On the other hand, in the case of preparing an antistatic resin composition by dilution of the master batch using the component (a) and/or component (b) based on the master batch containing the component (c) at a high concentration (Example 35 to 44), in the dilution step, the master batch was diluted using a single screw extruder having a gentler kneading property to prepare a pellet-shaped antistatic resin composition.

Thereafter, a desired molded product was produced by injection molding, or a sheet-like antistatic resin composition having a desired thickness was prepared while diluting the master batch using a single screw extruder equipped with a T die.

Once a master batch in which component (c) was highly finely dispersed was prepared, it was confirmed that the subsequent dilution process sufficiently exhibited antistatic performance even under gentle kneading conditions.

In the case of performing dilution processing of the high-concentration masterbatch (Examples 35 to 44), regarding injection molding described later, Tanabe Plastics Kikai Co., Ltd. single screw extruder VS40-28V (L/D = 28; with compression kneading zone) A pellet-shaped antistatic resin composition was prepared by using. In addition, regarding the extrusion sheet molding described later, a sheet-like antistatic resin composition having a desired thickness was produced using the sheet extrusion molding machine described below.

[Characteristics of Antistatic Resin Composition]

(Extrusion molding of antistatic resin composition and measurement of surface resistivity)

As described above, using pellets (Examples 1 to 34, Comparative Examples 1 to 24) containing the antistatic resin composition in which the donor/acceptor molecular compound as component (c) is highly finely dispersed, or the component ( A master batch containing c) in high concentration was diluted using component (a) and/or component (b) as a base (Examples 35 to 44), and an extruded sheet was produced by a single-screw T-die extruder.

T-die sheet molding is performed using a sheet extrusion machine FS40-36V+TS400 (shortened screw, with dulmage kneading, screw diameter 40 mm, L/D = 36, T die width 400 mm, mirror surface roll) manufactured by Ikegai Co., Ltd. , At a cylinder temperature of 210°C and a roll temperature of 70°C, single-layer sheets having a thickness of 0.20 mm were each produced by adjusting the screw rotation speed and the roll take-up speed.

In addition, only the blending composition using (a)-5 was carried out at a cylinder temperature of 230°C and a roll temperature of 80°C.

When evaluating the surface resistivity, the measurement was performed with a single-layer sheet, and the sheet for measurement was prepared by single-layer extrusion.

Both ends of the extruded sheet were trimmed by about 30 mm, respectively, to obtain a raw sheet having a width of 220 mm.

The surface resistivity in Examples and Comparative Examples was obtained by leaving the antistatic resin composition molded in a sheet shape in a constant temperature room at 23° C. and 50% humidity for 24 hours, and then using Simco Japan Co., Ltd. simple type surface resistivity meter “ST -3” was used for measurement.

The surface resistivity of the extruded sheet sample was taken as the average value of the measured values in the extrusion direction (MD) and the extrusion perpendicular direction (TD) on the front and back surfaces, respectively.

(Injection molding and haze value of antistatic resin composition)

The evaluation of the haze value of the antistatic resin composition used a flat plate by injection molding.

For injection molding, a hybrid injection molding machine FNX110III-18A (mold clamping force 110 tons) manufactured by Nissei Jushi Kogyo Co., Ltd. was used, and the mold had a thickness of 1 mm, a short side of 100 mm, and a long side of 150 mm, and a film gate was placed on the short side. A 1 mm thick flat molded product was obtained by adding 5% of the injection pressure to the shot point at a cylinder temperature of 210°C and a mold temperature of 50°C.

The molding cycle was performed at 7 seconds of injection and 25 seconds of cooling.

In addition, only the formulation (a)-5 was carried out at a cylinder temperature of 230°C.

A test piece for measurement was cut into a suitable size from a molded product having a thickness of 1 mm obtained by the injection molding described above, and the haze value was evaluated using a Haze Meter Model HZ-1 manufactured by Suga Shikenki Co., Ltd. (unit: %).

In addition, when the haze value exceeds 40%, since accurate measurement is impossible as specified in ISO14782, it was described as "more than 40 (opaque)" in the results of Examples and Comparative Examples.

[Examples 1 to 34, Comparative Examples 1 to 24]

Vinyl aromatic hydrocarbon-based resins (a)-1 to (a)-7 and donor/acceptor molecular compounds (c)-1 shown in [Table 1], and Production Examples 1 to 1 shown in [Table 2] Using the block copolymers (b)-1 to (b)-8 of 8, melt kneading using the twin screw extruder to obtain each resin composition in one step processing, and by the single screw T die extruder The surface resistivity of the obtained sheet-like antistatic resin composition having a thickness of 0.25 mm was measured, and the haze value was also measured using a 1 mm thick flat plate obtained by the injection molding machine.

The measurement results are shown in [Table 3] and [Table 4] below.

In addition, in the table, when the surface resistivity reaches 1 × 10 ¹² Ω/□ or less, the actual measured value is described, while when it does not reach 1 × 10 ¹² Ω/□ or less, the antistatic performance is expressed It was described as “Out” in the sense of being outside the range of possible surface resistivity.

[Production Examples 9 to 14]

Block copolymer (b), donor/acceptor molecular compound (c), and vinyl aromatic hydrocarbon-based resin (a) are used, and component (c) is 5% by mass when the total amount of master batch is 100% by mass Melt-kneading was performed with the twin-screw extruder according to the blending ratio shown in Table 5 below so as to be 20% by mass or more, and a master batch containing component (c) at a high concentration was prepared.

[Examples 35 to 44]

Diluting the master batch by blending the vinyl aromatic hydrocarbon-based resin (a) and/or the block copolymer (b) into the master batch containing the component (c) in high concentration prepared in [Production Examples 9 to 14] The surface resistivity of the sheet-shaped resin composition having a thickness of 0.25 mm obtained by the single-screw T-die extruder was measured by the method of two-step processing. In addition, the haze value was measured using a 1 mm thick flat plate obtained by the above injection molding machine.

Combined with the preparation example of the master batch used, the measurement results are shown in [Table 6] below.

[Example 35] shown in [Table 6] is an antistatic resin composition prepared by two-step processing through master batch, but the final composition itself is the same as [Example 9] shown in [Table 3].

Similarly, [Example 36] is [Example 13], [Example 37], [Example 15], [Example 38] is [Example 19], [Example 39], and [Example 44]. ] is [Example 11], [Example 40] is [Example 14], [Example 41] is [Example 7], [Example 42] is [Example 10] and [Example 10]. Example 43 is an antistatic resin composition having the same final composition as [Example 28].

In the case of two-stage processing through master batch, transparency was improved by about 0.1 (%) in haze value or equivalent.

As for the surface resistivity, it was found that, in any example, a lower surface resistivity was expressed in the case of two-stage processing through the master batch.

In the case of two-step processing in which a high-concentration masterbatch of component (c) is once produced and then diluted with component (a) and/or component (b), the surface resistivity is lower, and as a result, better antistatic properties are obtained. A resin composition could be prepared.

In other words, it was found that it is possible to reduce the amount of component (c) required to express the same surface resistivity, and to achieve both mechanical properties and economical efficiency.

In addition, when preparing the master batch, the effect of reducing the surface resistivity is excellent by using the block copolymer (b) and the donor/acceptor molecular compound (c) as essential components. It became clear by contrasting 43.

Specifically, when a high-concentration master batch was produced only with vinyl aromatic hydrocarbon-based resin (a) and donor/acceptor molecular compound (c) without using block copolymer (b), [Example 11] and [ As is evident by comparing the three examples of [Example 39] and [Example 44], the effect of improving the surface resistivity by the master batch method was not confirmed, and it was found that the result was not much different from that of one-stage kneading.

From the above results, the antistatic resin compositions of Examples exhibited the desired surface resistivity.

On the other hand, in Comparative Examples 1 to 24, the surface resistivity did not reach 1×10 ¹² Ω/□ or less even when a large amount of the donor/acceptor molecular compound (c) originally formulated to express antistatic properties was formulated, and this Difficulty was found in obtaining the antistatic resin composition of the invention.

In addition, after preparing a manufacturing method for obtaining an antistatic resin composition in one step and a high-concentration master batch containing component (b) and component (c) as essential components, component (a) and/or component (b) are prepared based thereon. ), in comparison of the above-described examples having exactly the same final composition, in comparison of the production methods for obtaining an antistatic resin composition by dilution using ), the antistatic resin obtained in two-step processing through the production of the latter high-concentration master batch It was found that the surface resistivity of the composition was more reduced and became a favorable trend. This is because the dispersion of the donor-acceptor molecular compound as component (c) is more finely dispersed, and the addition efficiency is improved.

[Example 45]

The antistatic resin composition obtained in Example 40 was used as a front and back layer with a thickness of 40 μm, and in the core layer, 90% by mass of vinyl aromatic hydrocarbon-based resin (a)-3 and 10% block copolymer (b)-1 were added. From the composition obtained by blending in the mass % ratio, a multilayer extruded sheet having a thickness of 0.3 mm was molded using a multilayer sheet extruder equipped with a T die.

T-die multi-layer sheet molding is performed using a multi-layer sheet extrusion machine GT-40-28-A+UT-25-28-H manufactured by Plastic Kogaku Genkyusho Co., Ltd. (shortened screw, equipped with syringite kneading, screw diameter 40 mm (core layer) + 25 mm (front and back layer), L/D = 28, T die width 400 mm, roll with corrugation), cylinder temperature 210 ° C., roll temperature 70 ° C., by adjusting the screw rotation speed and roll take-up speed, the above 0.3 mm Thick multilayer extruded sheets were fabricated.

The molded sheet was heated at 110°C, and a conveyance tray capable of accommodating electronic components was obtained by press molding.

The obtained tray for transporting electronic parts has surface resistivity of 10 to the 10th power, antistatic performance excellent in antistatic properties, moderate rigidity and heat deformation resistance, and excellent interlayer adhesive strength between the front and back layers and the core layer, and has good end surfaces. It was confirmed that it can be suitably used for practical use in that it is firmly adhered without peeling off and has excellent strength that is not easily broken even when intentionally bent.

In the present embodiment, the selectivity of the performance expression of the donor/acceptor molecular compound with respect to the matrix resin composition and the resin composition map that allows the expression of antistatic performance to be clarified, especially for the styrenic resin matrix.

The antistatic resin composition of the present invention exhibits good antistatic properties by exhibiting a surface resistivity of 1×10 ¹² Ω/□ or less, and furthermore, the donor/acceptor molecular compound, which is a substance that exhibits antistatic performance, exhibits good processability of the resin composition. However, since the influence on mechanical properties and optical properties is minimal, when the resin composition itself has transparency, the antistatic resin composition also maintains transparency, and furthermore, mechanical properties such as break resistance are also excellent, Type 2 3 It has industrial applicability as a material for packaging molded articles for electronic parts with excellent interlayer adhesive strength when used as an extruded multilayer sheet such as a layer.

In addition, the antistatic resin composition of the present invention has industrial applicability as a material for packaging materials for electronic parts, such as carrier tapes, magazine tubes, and trays for conveying electronic parts.

Claims (10)

A vinyl aromatic hydrocarbon-based resin (a);
a block copolymer (b);
Donor/acceptor type molecular compound (c)
An antistatic resin composition comprising
The block copolymer (b) is a block copolymer containing a vinyl aromatic hydrocarbon monomer unit and a conjugated diene monomer unit, and has a polymer block mainly composed of the vinyl aromatic hydrocarbon monomer unit, and the vinyl aromatic hydrocarbon monomer unit is 30 to 90 mass %, the conjugated diene monomer unit is 70 to 10% by mass,
When the total amount of the vinyl aromatic hydrocarbon-based resin (a) and the block copolymer (b) is 100% by mass, the mass ratio of the vinyl aromatic hydrocarbon-based resin (a) is 81% by mass or less, and the block copolymer The mass ratio of (b) is 19% by mass or more and less than 100% by mass;
The donor/acceptor molecular compound ( The content of c) is 0.5 mass % or more and 5 mass % or less,
The surface resistivity is 1×10 ¹² Ω/□ or less,
In the melt flow rate (MFR) under the 200 ° C. 5 kg load condition specified in ISO1133,
The relationship between the MFR (hereinafter referred to as MFRa) of the vinyl aromatic hydrocarbon-based resin (a) and the MFR (hereinafter referred to as MFRb) of the block copolymer (b),
An antistatic resin composition that satisfies any one of the following conditions (i) to (iv).
<Condition (i)>
When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 0% by mass and 30% by mass or less, and the component (b) is 70% by mass or more and 100% by mass If less than
Regardless of the numerical value of MFRa and MFRb, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.5% by mass or more and 5% by mass less than %.
<Condition (ii)>
When the total of the component (a) and the component (b) is 100% by mass, the component (a) is greater than 30% by mass and not more than 50% by mass, and the component (b) is less than 70% by mass 50% by mass If more than
MFRa<MFRb . . . (Equation 1)
In the case of a relationship, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.5% by mass or more and 5% by mass or less,
MFRa≥MFRb . . . (Equation 2)
In the case of a relationship, when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.9% by mass or more and 5% by mass or less.
<Condition (iii)>
When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 50% by mass and 70% by mass or less, and the component (b) is less than 50% by mass and 30% by mass If more than
MFRa<MFRb . . . (Equation 1)
The relationship of is satisfied, and when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 0.9% by mass or more and 5% by mass or less.
<Condition (iv)>
When the sum of the component (a) and the component (b) is 100% by mass, the component (a) is more than 70% by mass and 81% by mass or less, and the component (b) is less than 30% by mass and 19% by mass If more than
MFRa<MFRb . . . (Equation 1)
The relationship of is satisfied, and when the sum of the component (a), the component (b), and the component (c) is 100% by mass, the component (c) is 3% by mass or more and 5% by mass or less. The method of claim 1, wherein the vinyl aromatic hydrocarbon-based resin (a)
Homopolymers of vinyl aromatic hydrocarbon monomers (a1);
Graft copolymers (a2) of vinyl aromatic hydrocarbon monomers and
The antistatic resin composition which is any one selected from the group which consists of a random copolymer (a3) of a vinyl aromatic hydrocarbon monomer unit and (meth)acrylic acid and/or (meth)acrylic acid alkylester monomer unit. The method of claim 2, in the melt flow rate (MFR) under the 200 ° C. 5 kg load condition specified in ISO1133,
In the relationship between the MFR (hereinafter referred to as MFRa) of the vinyl aromatic hydrocarbon-based resin (a3) and the MFR (hereinafter referred to as MFRb) of the block copolymer (b),
An antistatic resin composition that satisfies the following conditions (v) or (vi).
<Condition (v)>
When the sum of the component (a3) and the component (b) is 100% by mass, the component (a3) is more than 0% by mass and 20% by mass or less, and the component (b) is 80% by mass or more and 100% by mass If less than, regardless of the values of MFRa and MFRb,
When the sum of the component (a3), the component (b), and the component (c) is 100% by mass, (c) is 0.5% by mass or more and 5% by mass or less.
<condition (vi)>
When the sum of the component (a3) and the component (b) is 100% by mass, the component (a3) is more than 20% by mass and 50% by mass or less, and the component (b) is less than 80% by mass and 50% by mass If more than
MFRa<MFRb . . . (Equation 1)
is satisfied, and when the sum of the component (a3), the component (b), and the component (c) is 100% by mass, the component (c) is 3% by mass or more and 5% by mass or less. The antistatic resin composition according to any one of claims 1 to 3, wherein the donor/acceptor molecular compound (c) is represented by the following general formula (1).

(In Formula (1), R ₁ and R ₂ are each independently CH ₃ (CH ₂ ) _n -CO-OCH ₂ (n is an integer of 12 to 22) or HOCH ₂ , and at least one is CH ₃ ( CH ₂ ) _n -CO-OCH ₃ (n is an integer from 12 to 22).
R ₃ and R ₄ are each independently selected from the group consisting of CH ₃ , C ₂ H ₅ , HOCH ₂ , HOC ₂ H ₄ and HOCH ₂ CH(CH ₃ ).
Here, "δ+" in the general formula (1) indicates that polarity exists in the covalent bond in the molecule, (+) indicates that the electron donating ability of the oxygen atom is strong, and (-) indicates that boron Indicates that the electron-withdrawing property of an atom is strong, "→" indicates a path through which electrons are attracted, and "---" indicates a state in which the bonding force between atoms is weakened.) A method for producing the antistatic resin composition according to any one of claims 1 to 3,
Using the block copolymer (b) and the donor/acceptor molecular compound (c), when the total amount of the master batch is 100% by mass, the donor/acceptor molecular compound (c) is 5% by mass or more and 20% by mass A step (I) of producing a masterbatch by melting and kneading at a composition ratio of % or less;
Step (II) of diluting the master batch by kneading the master batch with vinyl aromatic hydrocarbon-based resin (a) and/or block copolymer (b)
A method for producing an antistatic resin composition having a. An electronic component packaging material, which is a molded article of the antistatic resin composition according to any one of claims 1 to 3. delete delete delete delete