JP2002256125A - Conductive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive resin composition which hardly generates burr or chips during cutting or punching. SOLUTION: This resin composition is prepared by compounding (A) 100 pts.wt. styrene resin with (B) 5-50 pts.wt. conductive agent and (C) 11-44 pts.wt. impact modifier and has an MI of 3.5 g/10 min or higher. The impact modifier (C) may be (C1 ) a thermoplastic styrene elastomer, (C2 ) a thermoplastic olefin elastomer, (C3 ) a thermoplastic polyester elastomer, or the like. The conductive agent (B) may be carbon black. The composition is excellent in antistatic properties, has a surface resistivity of 1×10<11> Ω/square or lower, and, when molded, gives a sheet or a molded article suitable as a container or a packaging material for containing or transporting electronic parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive styrenic resin composition suitable for a container or a packaging material for housing or transporting semiconductors and electronic parts, and a sheet formed from the composition.

[0002]

2. Description of the Related Art Semiconductors and electronic components, especially integrated circuits (I
C) and packaging forms for electronic components using ICs
Trays (injection trays, vacuum forming trays, etc.), magazines, carrier tapes (embossed carrier tapes, etc.) and the like are used. As the thermoplastic resin constituting these packaging materials, polystyrene resin, A
BS resin, polyvinyl chloride resin, polypropylene resin, polyester resin, polyphenylene ether resin, polycarbonate resin, etc. are used,
Generally, it has a high surface specific resistance and is easily charged.

[0003] Therefore, it is necessary to impart conductivity to these packaging materials at least to an antistatic level in order to avoid the failure or destruction of the IC due to static electricity. As a method of imparting conductivity, for example, a method of blending a conductive agent such as conductive carbon black with a resin is known. Of the thermoplastic resins constituting the packaging material, even if a large amount of carbon black is blended, polystyrene resins are widely used because there is no remarkable decrease in fluidity and moldability, and the cost is excellent. .

[0004] Japanese Patent Application Laid-Open No. 1-230655 discloses that 100 parts by weight of a polystyrene component in a polystyrene resin is
1 to 15 parts by weight of mineral oil, butadiene rubber 1 to 1
A conductive resin composition having a melt index (MI) of 5 g / 10 min or more, in which 0 part by weight and 10 to 20 parts by weight of carbon black having a DBP oil absorption of 100 ml / 100 g or more are disclosed. However, with this resin composition, mechanical properties such as impact resistance and strength are not sufficient, and notches and cracks occur during secondary molding.

Japanese Patent Application Laid-Open No. 8-283584 discloses that 100 parts by weight of a polystyrene resin is mixed with 5 parts of carbon black.
JP-A-9-76423 discloses a conductive resin composition for IC packaging, which comprises 50 parts by weight, 1 to 30 parts by weight of an olefin resin, and 0.2 to 10 parts by weight of a styrene-conjugated diene block copolymer. Also disclosed is a conductive composite plastic sheet in which the conductive resin composition is laminated on both sides of a sheet substrate made of a polystyrene resin. The MI of these resin compositions is 0.1 g / 10 min or more, and in Examples, a resin composition of less than 3.5 g / 10 min is used. In these resin compositions and sheets,
In addition to low formability, burrs and chips are generated during cutting and punching. For example, when punching a perforation hole in a carrier tape, burrs and chips may be generated and may adhere to an IC or the like.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a conductive resin composition, a sheet, and a molded article in which generation of burrs and chips is suppressed in cutting and punching.

Another object of the present invention is to provide a conductive resin composition, a sheet, and a molded product in which the occurrence of notches and cracks during secondary molding is suppressed.

Still another object of the present invention is to provide a conductive resin composition, a sheet, and a molded article which are excellent in moldability and are also excellent in mechanical properties such as impact resistance and strength.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, they have added a specific amount of an impact modifier to a styrene resin containing a conductive agent, and
It has been found that the conductive resin composition adjusted to I suppresses the generation of burrs and chips during cutting and punching, and has completed the present invention.

That is, the conductive resin composition of the present invention comprises:
(A) Styrene resin, (B) Conductive agent and (C) Impact modifier
A resin composition containing a good agent, wherein (C)
When the amount is 11 to 10 parts by weight of the styrene resin (A),
44 parts by weight and a melt index (MI) of 3.
5 g / 10 minutes or more. (C) The impact modifier is
(C ₁) Styrenic thermoplastic elastomer, (C_Two)me
Fin elastomer, (C _Three) Polyester thermoplastic
Elastomers and the like. (B) Conductive agent is conductive
Carbon black may be used. (B) Ratio of conductive agent
In the case of (A) 100 parts by weight of the styrene resin,
It is about 50 parts by weight. The resin composition has an antistatic property
Excellent surface resistivity of 1 × 10¹¹Ω / □ or less.

The present invention also includes a sheet comprising at least a conductive layer, wherein the conductive layer is formed from the composition. The molded article formed from the sheet may be used for housing and transporting electronic components.

[0012]

DETAILED DESCRIPTION OF THE INVENTION [(A) Styrene resin] The styrene resin includes a polystyrene resin and a rubber-modified styrene resin. As the aromatic vinyl monomer for forming the polystyrene resin, for example, styrene,
Alkyl-substituted styrene (for example, vinyltoluene, vinylxylene, p-ethylstyrene, p-isopropylstyrene, butylstyrene, pt-butylstyrene, etc.), halogen-substituted styrene (for example, chlorostyrene, bromostyrene, etc.), α-position And α-alkyl-substituted styrene (for example, α-methylstyrene). These aromatic vinyl monomers can be used alone or in combination of two or more. Of these monomers, usually styrene, vinyl toluene,
α-Methylstyrene and the like, especially styrene, are used.

The aromatic vinyl monomer may be used in combination with a copolymerizable monomer. Examples of the copolymerizable monomer include, for example, a vinyl cyanide monomer (for example, acrylonitrile), an unsaturated polycarboxylic acid or an acid anhydride thereof (for example, maleic acid, itaconic acid, citraconic acid or the like). Acid anhydride, etc.), imide-based monomers [for example, maleimide, N-alkylmaleimide (for example,
N-C _1-4 alkylmaleimide), N-cycloalkylmaleimide (eg, N-cyclohexylmaleimide), N-arylmaleimide (eg, N-phenylmaleimide), acrylic monomer [eg,
(Meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
C _1-20 alkyl (meth) acrylates such as hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) Hydroxy C _2-4 alkyl (meth) acrylates such as phenyl acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate And the like]. These copolymerizable monomers are:
They can be used alone or in combination of two or more. The amount of the copolymerizable monomer in all the monomers is usually 1 to 50% by weight, preferably 5 to 40% by weight, more preferably 8% by weight.
It can be selected from a range of about 30% by weight.

The rubber-modified styrenic resin is obtained by copolymerization (graft polymerization, block polymerization, etc.), etc., so that the rubbery polymer (soft component) is formed into particles in a matrix (hard component) composed of the polystyrene resin. A dispersed polymer, usually in the presence of a rubbery polymer, at least an aromatic vinyl monomer (for example, the aromatic vinyl monomer, or the aromatic vinyl monomer and the copolymerizable monomer) Monomer) and a conventional method (bulk polymerization, bulk suspension polymerization,
Solution polymerization, emulsion polymerization, etc.).

As the rubbery polymer of the rubber-modified styrene resin, for example, diene rubber [polybutadiene (low cis type or high cis type polybutadiene), polyisoprene,
Styrene-butadiene copolymer, styrene-isoprene copolymer, butadiene-acrylonitrile copolymer, isobutylene-isoprene copolymer, styrene-isobutylene-butadiene copolymer rubber, etc.], ethylene-vinyl acetate copolymer, acrylic rubber ( _E.g. , a copolymer elastomer containing a C _2-8 alkyl polyacrylate as a main component), an ethylene-α-olefin-based copolymer [such as ethylene-propylene rubber (EPR)], and an ethylene-α-olefin-polyene copolymer. Combined [ethylene-propylene-
Diene rubber (EPDM), etc.], urethane rubber, silicone rubber, butyl rubber, hydrogenated diene rubber (hydrogenated styrene-butadiene copolymer, hydrogenated butadiene polymer, etc.). The above copolymer may be a random or block copolymer, and the block copolymer includes an AB type, an ABA type, a taper type, a copolymer having a radial teleblock type structure, and the like. . These rubbery polymers can be used alone or in combination of two or more. Preferred rubbery polymers are polymers of conjugated 1,3-dienes or derivatives thereof, especially diene rubbers [polybutadiene (butadiene rubber), isoprene rubber, styrene-butadiene copolymer, etc.].

In the rubber-modified styrenic resin, the content of the rubbery polymer is, for example, 2 to 80% by weight, preferably 3 to 50% by weight, particularly preferably 3 to 20% by weight (for example, 5 to 10% by weight). ).

The form of the rubbery polymer dispersed in the matrix composed of the polystyrene resin is not particularly limited, and may be a core / shell structure, an onion structure, a salami structure, or the like. The particle size of the rubbery polymer constituting the disperse phase is, for example, a volume average particle size of 0.05 to 30 μm, preferably 0.1 to 10 μm, and more preferably 0.2 to 7 μm.
It can be selected from a range of about μm (particularly 0.5 to 5 μm). In the rubber-modified styrenic resin, the graft ratio is about 5 to 300%, preferably about 10 to 250%.

Among these styrene resins, polystyrene resins include polystyrene (GPPS), styrene-acrylonitrile copolymer (AS resin), styrene-methyl methacrylate copolymer, and styrene-maleic anhydride copolymer. (SMA resin) and the like, and as the rubber-modified styrene resin, high impact polystyrene (HI
PS), styrene-butadiene block copolymer, styrene-acrylonitrile-butadiene copolymer (ABS
Resins), α-methylstyrene-modified ABS resin, imide-modified ABS resin, MBS resin and the like.

The styrene resin is preferably composed of at least a rubber-modified styrene resin, and may be used in combination with a rubber-modified styrene resin and a polystyrene resin. The ratio (weight ratio) of the rubber-modified styrene resin and the polystyrene resin is such that rubber-modified styrene resin / polystyrene resin = 100/0 to 50/50.
(Especially, about 100/0 to 60/40). In the styrene resin, the content of the rubbery polymer (soft component) is preferably 3 to 40% by weight, particularly preferably about 5 to 20% by weight.

The weight average molecular weight of the styrene resin (styrene resin constituting the matrix in the case of the graft copolymer) is from 10,000 to 1,000,000, preferably from 50,000 to 500,000, and more preferably from 50,000 to 500,000. It is about 100,000 to 500,000.

The melt index (MI) of the styrene resin at the time of melting is 200 ° C., a load of 49 N (5.0 kg).
1) to 10 g / 10 min in f), preferably 1 to 5 g / 10 min.
You can choose from a range of minutes.

[(B) Conductive agent] Examples of the component (B) include carbon powder (conventional artificial graphite powder, expanded graphite powder, natural graphite powder, coke powder, conductive carbon black, etc.), carbon fiber, metal powder and the like. And among them, conductive carbon black is preferably used. These conductive agents can be used alone or in combination of two or more.

Examples of the conductive carbon black include furnace black, channel black, gas black, acetylene black, arc black and the like. Among these conductive carbon blacks, carbon blacks having a DBP (dibutyl phthalate) oil absorption of 100 ml / 100 g or more, preferably 110 to 200 ml / 100 g are preferable. For example, furnace black, ketjen black, and acetylene having excellent conductivity Black, especially furnace black, is preferred. Further, a conductive composite carbon black obtained by combining these conductive carbon blacks may be used. The specific surface area of conductive carbon black, 20~300m ² / g, especially 30 to 50 m ² / g
The degree is preferred.

Commercially available conductive carbon blacks include, for example, "@ 3050B" and "@" manufactured by Mitsubishi Chemical Corporation.
3150B "," $ 3750B "," $ 3950B ",
"VULCAN XC72", "VULCAN" manufactured by Cabot Specialty Chemicals, Inc.
P "," BLACK PEARLS 3500 "," B
LACK PEARLS 3700 "and" Acetylene Black "manufactured by Denki Kagaku Kogyo KK can be used.

The average particle size of the conductive agent (especially conductive carbon black) has a close relationship with the ratio of the component (A) and cannot be specified unconditionally, but is usually 1 nm to 1 μm, preferably 10 to 100 nm. More preferably, 40 to 60 nm
It is about.

The proportion of the component (B) is 100% of the component (A).
5 to 50 parts by weight, preferably 20 to 4 parts by weight, based on parts by weight
0 parts by weight, more preferably 25 to 40 parts by weight (particularly 3 parts by weight)
0 to 40 parts by weight).

[(C) Impact Modifier] As the impact modifier, various elastomers composed of a hard component and a soft component can be used. For example, styrene thermoplastic elastomer, olefin thermoplastic elastomer, polyester Thermoplastic elastomer, polyvinyl chloride-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, thermoplastic polyurethane, and the like can be given. Among these elastomers, (C ₁ ) styrene thermoplastic elastomer, (C ₂ ) olefin thermoplastic elastomer,
A thermoplastic elastomer such as (C ₃ ) polyester thermoplastic elastomer is preferably used.

The (C ₁ ) styrene-based thermoplastic elastomer includes an elastomer in which the hard part is composed of styrene-based units and the soft part is composed of diene-based units, for example, a styrene-diene-based block copolymer or its water. Additives and the like are included. Examples of the styrene-diene-based block copolymer or its hydrogenated product include styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, and styrene-butadiene-styrene block copolymer (SB
S), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene block copolymer, hydrogenated styrene-isoprene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS) ), Hydrogenated styrene-isoprene-styrene block copolymer (SEPS) and the like. In the block copolymer, the terminal block may be composed of either a styrene block or a diene block.

As the (C ₂ ) olefin-based thermoplastic elastomer, a copolymer of an olefin and at least one monomer selected from a (meth) acrylic monomer and a vinyl ester monomer, Plastic elastomers (elastomer in which the hard part is composed of polyethylene or polypropylene and the soft part is composed of ethylene-propylene rubber or ethylene-propylene-diene rubber), ethylene-α-olefin-based copolymer [ethylene-propylene rubber (EPR) Etc.], ethylene-α-olefin-diene copolymer [ethylene-propylene-diene rubber (E
PDM), diene rubbers [polybutadiene (low cis type or high cis type polybutadiene), polyisoprene,
Butadiene-acrylonitrile copolymer, isobutylene-isoprene copolymer, etc.]. Among these olefinic thermoplastic elastomers, a copolymer of an olefin and a (meth) acrylic monomer and a copolymer of an olefin and a vinyl ester monomer are preferred.

Examples of the olefin monomer include ethylene,
C such as propylene, butene, hexene and octene_2-10Oh
Refin, preferably C_2-4Olefin (especially ethyl
) Can be exemplified. As acrylic monomers,
TA) acrylic acid, methyl (meth) acrylate, ethyl
(Meth) acrylate, butyl (meth) acrylate,
(Meth) such as 2-ethylhexyl (meth) acrylate
Acrylic acid C_1-10Alkyl ester, preferably ethyl
(Meth) acrylic acid C such as (meth) acrylate _1-10
An example is an alkyl ester. Vinyl ester based simple substance
Fats such as vinyl acetate and vinyl propionate
Acid vinyl esters can be exemplified. Specifically, ethylene
-Ethyl acrylate copolymer, ethylene-vinyl acetate
Copolymers and the like can be preferably used.

Examples of the (C ₃ ) polyester-based thermoplastic elastomer include elastomers in which the hard portion is composed of alkylene arylate units and the soft phase is composed of aliphatic polyether or polyester units. As the aliphatic polyether constituting the soft layer, for example,
Examples thereof include poly C _2-6 alkylene oxides such as polyethylene oxide, polypropylene oxide, and polytetramethylene oxide. Examples of the aliphatic polyester include aliphatic C _2-6 dicarboxylic acids (eg, oxalic acid, succinic acid, adipine) Acids, etc.) and aliphatic C _2-6 diols (eg, ethylene glycol, propylene glycol, 1,
Examples thereof include polyesters with 4-butanediol, 1,3-butanediol, neopentyl glycol, hexanediol, and the like. The alkylene arylate constituting the hard phase, ethylene terephthalate, or C _2-4 alkylene terephthalate such as polybutylene terephthalate, ethylene naphthalate and polybutylene naphthalate C _2-4 alkylene naphthalate, preferably C _2-4 alkylene Terephthalate (especially ethylene terephthalate) can be exemplified.

The molecular structure of the thermoplastic elastomer is as follows:
There is no particular limitation, and a triblock copolymer, a star block copolymer, a multiblock copolymer, a graft copolymer, an ionomer, or the like may be used.

These impact modifiers can be used alone or in combination of two or more. When a single elastomer is used as the component (C), the proportion of the component (C) is
It is about 11 to 44 parts by weight, preferably about 15 to 40 parts by weight, and more preferably about 20 to 30 parts by weight, based on 100 parts by weight of the component. If the proportion of the component (C) is too small, the dimensional accuracy is poor even if the sheet is subjected to secondary molding (vacuum, air pressure, press molding, etc.), and particularly the edges of the container become thin, and stress concentrates when bent. , Easy to break. On the other hand, if the proportion of the component (C) is too large, burrs may be generated during cutting or punching, and the contents may be contaminated.

In the present invention, a combination of impact modifiers is used.
Preferably, for example, (C ₁) Styrene-based heat
Plastic elastomer and (C_Two) Olefin thermoplastic elastomer
Stomer and / or (C_Three) Polyester thermoplastic
Combination with lastmer, especially (C₁) Styrene thermoplastic
Elastomer and (C_Two) Olefin-based thermoplastic elastomer
Combination with Tomer is effective. These combinations
In addition to the effect of impact improvement, (C₁) Component
Structural units (or building blocks, cells,
To improve the compatibility with the component (A).
Can be. Also, (C_Two) And / or (C_Three) Components (especially
(C_Two) Component ethylene copolymer) and component (B)
Compatibility can be increased. (C_Two) Component and (C_Three)
(C based on the total amount of components₁) The proportion (weight ratio) of the components is
(C₁) / (C_Two+ C_Three) = 3/1 to 1/10, preferably
Is about 2/1 to 1/5, more preferably about 1/1 to 1/5.
Degrees. Combining multiple elastomers as component (C)
When used together, the proportion of component (C) is particularly limited.
0.1 to 100 parts by weight of component (A)
Parts by weight, preferably 1 to 50 parts by weight, more preferably
About 10 to 40 parts by weight (particularly 20 to 30 parts by weight)
You.

In the present invention, it is also preferable to use the (C ₃ ) polyester thermoplastic elastomer alone.
When the (C ₃ ) polyester thermoplastic elastomer is used alone as the component (C), the proportion of the component (C ₃ ) is as follows:
There is no particular limitation, and the amount is 0.1 to 100 parts by weight of the component (A).
1 to 100 parts by weight, preferably 1 to 50 parts by weight, more preferably 10 to 40 parts by weight (particularly 20 to 30 parts by weight)
It is about.

The ratio (weight ratio) of the hard component to the soft component in the components (A) and (C) is as follows: hard component / soft component = 95
/ 5 to 50/50, preferably 90/10 to 60/4
0, more preferably about 90/10 to 70/30. When the ratio between the soft component and the hard component is in the above range, it is possible to achieve both the moldability and the mechanical properties.

[Conductive resin composition] The conductive resin composition may be a mixture of powders of the components (A) to (C), and is prepared by kneading the components (A) to (C). May be. For the kneading, a conventional method can be used. For example, each component is dry-mixed with a Henschel mixer or a ribbon mixer, and a conventional melt mixing such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, a mixing roll, or the like is used. It can be supplied to the machine and melt-kneaded. The conductive resin composition may be in the form of a pellet.

The conductive resin composition may contain, if necessary, an antistatic agent (a surfactant having a weight average molecular weight of 3000 or less), a coloring agent, a dispersant, a release agent, and a stabilizer (an antioxidant, UV absorbers, heat stabilizers, etc.), flame retardants, anti-blocking agents, lubricants, fillers, defoamers, coatability improvers,
A thickener or the like may be added. Among these additives, a lubricant (for example, a wax or a C _8-24 higher fatty acid ester or amide) is added in an amount of 1 to 100 parts by weight of the component (A).
It is preferable to use 20 parts by weight, preferably about 3 to 15 parts by weight.

The MI of the conductive resin composition of the present invention is 20
3.5 g / 10 min or more, preferably 3.5 to 10 g / 10 min, more preferably 3.6 to 8 g / 10 min (particularly 3.7 to 6 g / 10) at 0 ° C. and a load of 49 N (5.0 kgf).
Min). If the MI is too low, extruding into a sheet shape increases the molecular orientation of the surface layer, and tends to generate burrs during punching. On the other hand, when the MI is too high, the thickness tends to be uneven when the secondary molding is performed.

The conductive resin composition of the present invention has a surface specific resistance of 1 × 10 ¹¹ Ω / □ or less (for example, 1 × 10 ⁰ to 1 ×).
10 ¹¹ Ω / □), preferably 1 × 10 ¹ to 1 × 10 ⁸ Ω /
□, more preferably about 1 × 10 ² to 1 × 10 ⁶ Ω / □, which is very excellent in conductivity.

[Production Method of Sheet] The production method of the conductive resin sheet is not particularly limited, and the resin composition is supplied to a usual extruder, melted and kneaded to form a die [flat, T-shaped.
(T die), cylindrical shape (circular die), etc.]. The sheet may be stretched (uniaxially stretched, biaxially stretched, or the like), but is usually an unstretched sheet in which a draw (drawing) is applied in the extrusion direction. If necessary, foam extrusion may be carried out using a foaming agent (chemical foaming agent or gas).

The sheet of the present invention is a sheet composed of at least a conductive layer formed of the resin composition, and may be a single-layer sheet or a laminated sheet composed of a plurality of layers. Good. The laminated sheet is a laminated sheet in which a conductive layer composed of the conductive resin composition is formed on at least one surface of the base sheet, and depending on the application, it may be sufficient to laminate the conductive layer on only one surface. However, it is usually preferable to laminate conductive layers on both sides of the base sheet. The material of the base sheet is not particularly limited as long as the formability and impact resistance are not impaired, and the styrene-based resin, olefin-based resin (eg, polyethylene, polypropylene, etc.), polyester-based resin (eg, polyethylene terephthalate, poly) Homopolyesters such as butylene terephthalate or copolyesters, etc.), polyamide resins (eg, nylon 6, nylon 66, nylon 61)
Thermoplastic resin such as polycarbonate resin (for example, bisphenol A-type polycarbonate). Of these, thermoplastic resins of the same type as the resin constituting the conductive layer, particularly styrene resins, are preferred.

The ratio of MI between the conductive resin composition and the styrene-based resin constituting the base sheet is as follows: conductive resin composition / base sheet = 0.7 to 5, preferably 1 to 4.5, more preferably 1 to 4.5. Preferably, it is about 1.2 to 4.5. If the ratio of the two MIs is too low, irregularities occur on the sheet surface, and if the ratio of the two MIs is too high, the difference in fluidity between the two resins becomes too large, so that the lamination ratio differs between the center part and both end parts. In addition, the conductivity and the mechanical strength become non-uniform.

The thickness of the conductive sheet is 0.01 to 5 m
m, preferably about 0.05 to 3 mm, and more preferably about 0.1 to 1 mm.

In the case of a laminated sheet, the ratio of the thickness of the base sheet to each conductive layer is as follows: base sheet / conductive layer = 30/1 to 1/1
1, preferably 20/1 to 2/1, more preferably 1
It is about 5/1 to 5/1. The thickness of each conductive layer is 1 to 5
The thickness is about 00 μm, preferably about 5 to 300 μm, and more preferably about 10 to 100 μm. The thickness of the base sheet is
10 to 5000 μm, preferably 50 to 3000 μm,
More preferably, it is about 100 to 1000 μm.

The laminated sheet may be prepared by a method such as heat lamination or dry lamination.
The base sheet and the conductive layer are preferably prepared by a co-extrusion method. Note that the lamination method does not necessarily require an adhesive.

[Secondary molded article] The sheet obtained in this manner is subjected to conventional thermoforming such as free blow molding, vacuum molding, bending, air pressure molding, match molding, hot plate molding and the like. Next can be molded. The sheet is
If necessary, it may be foamed. As a secondary molded product,
For example, a food container, a medicine container, a tray, an embossed tape, a magazine and the like can be mentioned.

The surface of the sheet or the secondary molded article may be subjected to a surface treatment (for example, discharge treatment such as corona discharge or glow discharge, acid treatment, flame treatment, etc.). The surface of the sheet or the secondary molded article may be subjected to a conductive treatment or an antistatic treatment (for example, application or kneading of a conductivity imparting agent such as an antistatic agent or a metal oxide) to prevent the surface of the sheet or the secondary molded product from being charged. An prevention layer (for example, a coating with a conductive ink) may be formed.

The sheet of the present invention has not only excellent antistatic properties but also excellent moldability and mechanical properties. Therefore, among the secondary molded products, semiconductors and electronic parts, particularly ICs and electronic devices using ICs, are used. A transfer molded product having a storage recess for storing components [for example, an electronic component transfer tray (injection tray, vacuum forming tray, etc.), a magazine,
Carrier tape (such as an embossed carrier tape)].

[0050]

According to the present invention, it is possible to obtain a conductive resin composition in which generation of burrs and chips during cutting and punching, and generation of notches and cracks during secondary molding are suppressed. Since the conductive resin composition is excellent in moldability and mechanical properties such as impact resistance and strength, it is suitable as a container or packaging material for housing or transporting semiconductors and electronic components.

[0051]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, the evaluation method of each evaluation item in an Example, and the content of each component used are as follows.

[Melt Index] The pellets obtained by strand cutting were subjected to melt indexer L244.
(Manufactured by Takara Industry Co., Ltd.). 20 pellets
A load of 5 kg weight (49 N) was applied at 0 ° C., and the weight of the resin discharged from the nozzle having an inner diameter of 2 mm for a predetermined time was measured, and this was converted into the weight of the resin discharged in 10 minutes to obtain the MI value.

[Surface Specific Resistance] The pelletized resin was molded into a sheet having a thickness of 300 μm with a T-die having a width of 120 mm using an extruder having a diameter of 25 mm and measured. Using a Lorester surface resistance meter (manufactured by Mitsubishi Chemical Corporation), measure any 10 points in the sample using an annular electrode with an outer diameter of 6 mm for the inner circle and 11 mm for the inner diameter of the outer circle, and logarithmically average the surface resistivity value. And

[Folding strength of molded article] The embossed carrier tape was repeatedly bent by 180 ° by hand so that the embossed portion was on the outside, and then returned to the original state, and the number of times until cracking was measured. .

[Burr occurrence frequency] An arbitrary 100 holes were formed in the flange portion.
The number of burrs of μm or more was counted.

[Abbreviations and Details of Each Component] HIPS-1: High impact polystyrene (Toyo Styrene Co., Ltd., Toyostyrol H610) HIPS-2: High impact polystyrene (Toyo Styrene Co., Ltd., Toyostyrol H53C) HIPS -3: High impact polystyrene (Toyo Styrene Co., Ltd., Toyostyrol E640) Lubricant: Stearyl stearate (RIKEN Vitamin Co., Ltd.)
CB: Carbon black (manufactured by Mitsubishi Chemical Corporation, # 303
0B) EEA: Ethylene-ethyl acrylate copolymer (NUC-6170, manufactured by Nippon Unicar Co., Ltd.) EVA: Ethylene-vinyl acetate copolymer (Evatate K4011, manufactured by Sumitomo Chemical Co., Ltd.) SBS: Styrene-butadiene block copolymer SEBS: Styrene-ethylene-butylene copolymer (Asahi Kasei Corp., Tuftec H1051) SBBS: Styrene-butadiene-butylene copolymer (Asahi Kasei Corp., Tuftec JT82P) SEPS-1: Styrene-ethylene-propylene copolymer (Kuraray Co., Ltd., Septon 2104) SEPS-2: Styrene-ethylene-propylene copolymer (Kuraray Co., Ltd., Septon 2043) PE / E: Polyester elastomer (Toray)・ DuPont, Hytrel 057).

Examples 1 to 17 and Comparative Examples 1 to 7 After the components were dry-blended using a tumbler at the ratios shown in Tables 1 and 2, a twin-screw extruder (L) having a diameter of 30 mm was used.
/ D = 32), melt-kneaded at a cylinder temperature of 210 ° C., and then pelletized by a strand cut method.
A conductive resin composition was obtained. HIPS-3: 90 parts by weight and SB: 10 parts by weight were dry blended with a tumbler to obtain a resin composition constituting a base material layer (MI = 3.1 g /
10 minutes).

Using a multilayer extruder (two-type three-layer extruder)
A resin composition constituting the base material layer was charged into a single screw extruder (L / D = 32) having a diameter of 65 mm at a cylinder temperature of 210 ° C., and the conductive resin composition was charged into a single screw extruder (L / D = 28) having a diameter of 50 mm. Materials are charged at a cylinder temperature of 210 ° C,
In the feed block, the conductive layers are joined to each other on both sides of the base material layer, laminated, and subjected to a die temperature 210 by a T-die casting method.
After being extruded into a sheet shape at a temperature of ° C., it was cooled by a cooling roll to obtain a laminated sheet having a total thickness of 300 μm (thickness ratio: conductive layer / base layer / conductive layer = 20 μm / 260 μm / 20 μm). This sheet was slit to a width of 24 mm, and a flange having a width of 4 mm on one side and a width of 1 mm on the other side was formed by hot press molding.
mm was embossed to obtain a carrier tape. 4
The distance from the center of the hole to the center is 4m in the mm width flange.
A perforation hole having a diameter of 1.5 mm was provided at regular intervals so as to be m. The interval between the embosses was 5 mm. Table 1 shows the evaluation results of the obtained sheet and carrier tape.

[0059]

[Table 1]

[0060]

[Table 2]

From the results of Tables 1 and 2, in the examples, the conductivity is excellent, the strength is high, and the occurrence of burrs is small. On the other hand, in Comparative Example 1, the strength was low, and Comparative Examples 2 to 7
Then, burr often occurs.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 53:02) C08L 53:02) (C08L 25/04 (C08L 25/04 23:02) 23:02 ) (C08L 25/04 (C08L 25/04 67:00) 67:00) F-term (reference) 4F071 AA12 AA13 AA15 AA20 AA22 AB03 AB06 AF37Y AF38Y AH04 BB06 BC01 4J002 AC032 AC062 AC072 AC082 BB042 BB062 BB072 BB082 BB072 BB081 BC041 BC051 BC061 BC071 BC081 BC091 BC111 BG022 BN051 BN061 BN071 BN081 BN091 BN121 BN141 BN151 BN161 BN171 BN211 BN231 BP012 CF002 CF092 CF102 DA026 DA036 DA066 FA046 FD116 GG01 5G301 DA18 DA10

Claims (16)

[Claims] 1. A resin composition comprising (A) a styrene resin, (B) a conductive agent and (C) an impact modifier, wherein (C)
A conductive resin composition wherein the ratio of the impact modifier is 11 to 44 parts by weight based on 100 parts by weight of the styrene resin (A) and the melt index (MI) is 3.5 g / 10 minutes or more. 2. The composition according to claim 1, wherein (C) the impact modifier is a thermoplastic elastomer. 3. The (C) impact modifier is at least one selected from (C ₁ ) styrene thermoplastic elastomer, (C ₂ ) olefin thermoplastic elastomer and (C ₃ ) polyester thermoplastic elastomer. The composition of claim 1. 4. The composition according to claim 3, wherein the (C ₁ ) styrene-based thermoplastic elastomer is at least one selected from a styrene-diene-based block copolymer and a hydrogenated styrene-diene-based block copolymer. . 5. The (C ₂ ) olefin thermoplastic elastomer is a copolymer of an olefin and at least one monomer selected from a (meth) acrylic monomer and a vinyl ester monomer. A composition according to claim 3. 6. The ratio (weight ratio) of the hard component and the soft component in (A) the styrene-based resin and (C) the impact modifier is (hard component / soft component) = 95/5 to 50/50. Item 10. The composition according to Item 1. 7. The (C) impact modifier comprises (C ₁ ) a styrene thermoplastic elastomer and at least one selected from a (C ₂ ) olefin thermoplastic elastomer and a (C ₃ ) polyester thermoplastic elastomer. And the ratio (weight ratio) of the component (C ₁ ) to the total amount of the components (C ₂ ) and (C ₃ ) is (C ₁ ) / (C ₂ +
2. The composition according to claim 1, wherein C ₃ ) = 5/1 to 1/20. 8. The composition according to claim 1, wherein (B) the conductive agent is conductive carbon black. 9. The ratio of component (B) is 100% of component (A).
The composition according to claim 1, wherein the amount is 5 to 50 parts by weight based on parts by weight. 10. The composition according to claim 1, which has a surface resistivity of 1 × 10 ¹¹ Ω / □ or less. (A) a rubber-modified styrenic resin,
A resin composition containing (B) a conductive carbon black and (C) an impact modifier, wherein 10 to 40 parts by weight of component (B) and 15 to 15 parts by weight of component (C) based on 100 parts by weight of component (A).
Contains 40 parts by weight, melt index (MI)
Is 3.5 to 10 g / 10 min and the surface resistivity is 1 × 10 ¹
A conductive resin composition having a density of about 1 × 10 ⁸ Ω / □; 12. A resin composition comprising (A) a styrene-based resin, (B) a conductive agent, and (C) an impact modifier,
(C) A conductive resin composition in which the impact modifier is composed of a combination of (C ₁ ) a styrene thermoplastic elastomer and a (C ₂ ) olefin thermoplastic elastomer, or (C ₃ ) a polyester elastomer. 13. A sheet comprising at least a conductive layer, wherein the conductive layer is formed of the composition according to claim 1. 14. The sheet according to claim 13, wherein conductive layers are formed on both surfaces of the base sheet made of a styrene-based resin. 15. A molded article formed from the sheet according to claim 13. 16. The molded article according to claim 15, which is used for housing and transporting electronic components.