CN101376732A - Conductive plastic composition - Google Patents

Abstract

The present invention provides a conductive plastic composition comprising: a copolymer comprising a styrene block and an acrylate block; (B) a copolymer comprising an olefin block and an enoate block; and (C) carbon black. The composition contains 5 to 40 parts by weight of the copolymer (B) containing an olefin block and an enoate block per 100 parts by weight of the copolymer containing a styrene block and an acrylate block; and 5 to 35 parts by weight of the carbon black (C) per 100 parts by weight of the copolymer containing a styrene block and an acrylate block.

Description

conductive plastic composition

technical field

The present invention relates to a plastic composition. More specifically, the present invention relates to an electrically conductive plastic composition. The conductive plastic composition is preferably used for producing sheets for packaging containers for semiconductors such as electronic parts including ICs.

Background technique

For packaging and shipping electronic parts containing ICs, injection molded trays, vacuum formed trays, carrier tapes (also called embossed carrier tapes), etc. have been used. In order to prevent electronic parts from being damaged due to static electricity from friction or insulation, a packaging container including a thermoplastic resin component and a conductive component has been developed. Such packaging containers typically include a lidding film to seal and secure electronic components during packaging, transport and assembly. The thermoplastic resin component generally contains acrylonitrile-butadiene-styrene type resin, polystyrene type resin, polyvinyl chloride resin or styrene-co-butylene resin, and uses fine metal powder, carbon fiber and conductive carbon black as a conductive component.

In order to meet the requirements of small size and fast packaging speed, the mechanical strength of the packaging container should be enhanced. There has been proposed a packaging container made of a composite plastic sheet, the conventional composite plastic sheet comprising a substrate layer and a conductive surface layer laminated on at least one side of said substrate layer. The most commonly used materials for the substrate layer are acrylonitrile-butadiene-styrene (ABS), polystyrene (PS) and polycarbonate (PC) due to their excellent mechanical strength. But on the other hand, the material of the conventional conductive surface layer is limited in order to seal this conventional sheet to the lidding film. Thus, the compatibility between the conventional substrate layer and the conductive surface layer is not satisfactory, and this often results in separation of these two layers from each other.

Therefore, there is a need in the art for an electrically conductive plastic composition for producing an electrically conductive surface layer with acceptable mechanical strength, capable of sealing to a lidding film and having satisfactory compatibility with a substrate layer.

Contents of the invention

The invention provides a conductive plastic composition comprising:

(A) a copolymer comprising styrene blocks and acrylate blocks;

(B) a copolymer comprising olefin blocks and acrylate blocks; and

(C) carbon black;

The composition contains 5 to 40 parts by weight of the copolymer comprising olefin blocks and acrylate blocks per 100 parts by weight of the copolymer (A) comprising styrene blocks and acrylate blocks (B); and containing 5 to 35 parts by weight of the carbon black (C) per 100 parts by weight of the copolymer (A) comprising a styrene block and an acrylate block.

In another aspect, the present invention provides a conductive plastic sheet made of the above composition.

In yet another aspect, the present invention provides a conductive composite plastic sheet comprising a substrate layer and a conductive surface layer laminated on at least one side of the substrate layer, wherein the conductive surface layer is made of the above-mentioned conductive plastic sheet become.

Description of drawings

none

Detailed ways

The present invention provides a novel conductive plastic composition for preparing conductive plastic sheets having good sealing strength, mechanical strength and surface resistivity. A packaging container for packaging and transporting electronic parts or ICs made of the conductive plastic sheet according to the present invention can be sealed to a lidding film and has satisfactory compatibility with a substrate layer.

The conductive plastic composition comprises:

(A) a copolymer comprising styrene blocks and acrylate blocks;

(B) a copolymer comprising olefin blocks and acrylate blocks; and

(C) carbon black;

The composition contains 5 to 40 parts by weight of the copolymer comprising olefin blocks and acrylate blocks per 100 parts by weight of the copolymer (A) comprising styrene blocks and acrylate blocks (B); and containing 5 to 35 parts by weight of carbon black (C) per 100 parts by weight of the copolymer (A) comprising a styrene block and an acrylate block.

The compositions according to the invention are used to form conductive plastic sheets.

Preferably, the conductive plastic sheet is used to manufacture a conductive composite plastic sheet comprising a substrate layer and a conductive surface layer laminated on at least one side of the substrate layer, wherein the conductive surface The layers comprise the compositions described above.

Additionally, the packaging container comprises a conductive composite plastic sheet and a lidding film as described above.

The styrene blocks of the copolymer (A) comprising styrene blocks and acrylate blocks are designed to maintain a low softening point that facilitates sealing to the lidding film. Preferably, the copolymer (A) comprising styrene blocks and acrylate blocks comprises 10 to 80 wt% of styrene blocks.

In a preferred aspect of the present invention, the acrylate block of the copolymer (A) comprising a styrene block and an acrylate block is selected from acrylate, methacrylate, methyl methacrylate, butyl acrylate Groups consisting of esters and mixtures thereof. The acrylate block is a polar block having excellent compatibility with the substrate layer of the conductive composite plastic sheet according to the present invention. Furthermore, the polar acrylate blocks have satisfactory sealing properties for lidding films when applied to packaging containers according to the invention.

In a preferred aspect of the present invention, the copolymer (A) comprising styrene blocks and acrylate blocks further comprises diene blocks. In a more preferred aspect, the diene block is butadiene. Specifically, when the diene block is incorporated, the copolymer (A) has fairly good firmness, flexibility and folding resistance, and both the seal strength between the container and the cargo and the adhesion to carbon black have been improved.

In a more preferred aspect of the present invention, the copolymer (A) comprising styrene blocks and acrylate blocks is selected from the group consisting of styrene-methyl methacrylate copolymer, styrene-butadiene-methyl The group consisting of methyl acrylate copolymer, styrene-butadiene-butyl acrylate copolymer, styrene-butadiene-methyl methacrylate-acrylonitrile copolymer and mixtures thereof.

According to the invention, the copolymer (B) comprising olefin blocks and acrylate blocks is used to improve the compatibility between the copolymer (A) comprising styrene blocks and acrylate blocks and the substrate layer properties, and prevent the conductive surface layer from separating from the substrate layer. Furthermore, the copolymer (B) comprising olefin blocks and enolate blocks is also fastened to the lidding film.

In a preferred aspect of the present invention, the olefin block of the copolymer (B) comprising an olefin block and an enolate block is ethylene.

In a preferred aspect of the present invention, the acrylate block of the copolymer (B) comprising olefin block and acrylate block is selected from butyl acrylate, methacrylate, vinyl acrylate and other A group of mixtures.

In a more preferred aspect of the present invention, the copolymer (B) comprising olefin blocks and acrylate blocks is selected from the group consisting of ethylene-butyl acrylate, ethylene-methyl acrylate, ethylene-vinyl acrylate and other A group of mixtures.

In a preferred aspect of the present invention, the composition contains 20 to 30 parts by weight of the olefin block-containing block and acrylate block copolymer (B).

或Ketjen 

的高结构碳黑。所述碳黑应以某一量并入，以使表面电阻率在10²到10⁸Ω的范围内，且优选地从10³到10⁶Ω。如果表面电阻率超过10⁸Ω，那幺不能获得足够的抗静电效应，且如果其小于10²Ω，那幺过高的电力生产能力将从而破坏电子零件。对于每100重量份的所述包含苯乙烯嵌段和丙烯酸酯嵌段的共聚物(A)，碳黑(C)的量为从5到35重量份，优选地从20到30重量份。如果所述量小于5重量份，那幺不能获得足够的导电性，且表面电阻率将增大。另一方面，如果其超过35重量份，那幺往往难以均匀分散到树脂中，可模制性往往显着变坏，且例如机械强度的特性亦会变坏。In a preferred embodiment of the present invention, the carbon black (C) is selected from the group consisting of furnace black, channel black, superconducting furnace black and conductive furnace black. More preferably, the carbon black (C) has a larger specific surface area, whereby a higher conductivity grade can be obtained with a small amount of carbon black. For example, it could be

or Ketjen

high structure carbon black. The carbon black should be incorporated in an amount such that the surface resistivity is in the range of 10 ² to 10 ⁸ Ω, and preferably from 10 ³ to 10 ⁶ Ω. If the surface resistivity exceeds 10 ⁸ Ω, sufficient antistatic effect cannot be obtained, and if it is less than 10 ² Ω, excessive power production capability will thereby destroy electronic parts. The amount of carbon black (C) is from 5 to 35 parts by weight, preferably from 20 to 30 parts by weight, per 100 parts by weight of the copolymer (A) comprising styrene blocks and acrylate blocks. If the amount is less than 5 parts by weight, sufficient conductivity cannot be obtained and surface resistivity will increase. On the other hand, if it exceeds 35 parts by weight, uniform dispersion in the resin tends to be difficult, moldability tends to remarkably deteriorate, and characteristics such as mechanical strength also deteriorate.

In a preferred embodiment of the present invention, the composition further comprises (D) styrene-butadiene copolymer, ethylene-vinyl acetate or chlorinated polyethylene. In particular, the styrene-butadiene copolymers provide fairly good elongation strength without altering the strength of the seal between the packaging container and the cargo.

Furthermore, various additives can be added to the composition according to the invention, such as lubricants, plasticizers, processing aids, reinforcing agents (resin modifiers) or to improve the flow properties of the composition and the dynamic properties of molded products Other resin components and their mixtures.

或

双螺杆挤压机的常规机器实现。To prepare the composition, the starting materials can be kneaded together at the same time, or the starting materials can be kneaded step by step and then finally the kneaded products are brought together and kneaded again. Kneading can be done by eg

or

A conventional machine realization of a twin-screw extruder.

According to the invention, this substrate layer comprises a thermoplastic resin. For example, the thermoplastic resin is acrylonitrile-butadiene-styrene, polystyrene or polycarbonate. Preferably, the substrate layer is acrylonitrile-butadiene-styrene. The thickness of the foil layer is preferably between 0.1 and 3.0 mm, and the thickness of the conductive surface layer is 2 to 80% of the thickness of the conductive composite plastic foil.

According to the present invention, the lidding film is heat-sealed or pressure-sealed to the surface of the conductive composite plastic sheet. Preferably, the lidding film is a poly(ethylene terephthalate) (PET) film.

Packaging containers according to the invention may be manufactured by any conventional method, for example a method selected from the group consisting of pressure forming, vacuum forming and thermoforming.

The following examples are given for illustrative purposes only and are not intended to limit the scope of the invention.

Examples 1 to 5 and comparative examples 1 to 6

Table 1 lists the content of the composition. The material of the substrate layer is acrylonitrile-butadiene-styrene resin. Each material was weighed and uniformly mixed with a high-speed mixer, then kneaded by means of ψ125 mm and ψ40 mm open twin-screw extruders, and granulated by a wire cutting method to obtain conductive plastic flakes as a conductive surface layer. This substrate layer was laminated on each side with a conductive surface layer to form a 0.3mm sheet, with a conductive surface layer:substrate layer:conductive surface layer thickness ratio of 1:8:1.

Table 1:

Comparative example 6 is ECM3,

Copolymer (A) comprising styrene blocks and acrylate blocks:

Styrene-methyl methacrylate copolymer: PM-200,

Styrene-butadiene-methyl methacrylate copolymer: TI-300S,

Styrene-butadiene-methyl methacrylate-acrylonitrile copolymer: TOYOLAC920,

Copolymer (B) comprising olefin blocks and enolate blocks:

Ethylene-methyl acrylate: EMA 1209, TC020, Exxon

Ethylene-butyl acrylate: EBA 3107,

(C) carbon black:

EC-300J，KETJEN BLACK INTERNATIONAL  Carbon black: granular type,

EC-300J, KETJEN BLACK INTERNATIONAL

(D) Styrene-butadiene copolymer:

HP9450，FORMOSACHEMICALS & FIBRE 

Styrene-butadiene copolymer: PH-88S, CHI MEI

HP9450, FORMOSACHEMICALS & FIBER

Taipol 3152. Hydrogenated styrene-butadiene copolymer: H1043,

Taipol 3152.

The characteristics of Examples 1 to 5 and Comparative Examples 1 to 6 were evaluated according to the methods enumerated below:

Surface Resistivity: According to ASTM D-257, the surface resistivity within the detectable range is used.

Seal Strength: 25 mm wide strips prepared from the sheets of Examples 1 to 5 and Comparative Examples 1 to 6 were passed through a sealing machine (by Manufactured TP-1000) was sealed with the lidding film, and the sealing strength of the conductive plastic sheet and the lidding film was tested according to the EIA-481 method by means of a peel tester (JE PFT-500 manufactured by OVERTOP TECHNOLOGY CO., LTD.) Measurement.

Mechanical Properties: Each of the sheets of Examples 1 to 5 and Comparative Examples 1 to 6 were cut in their transverse and longitudinal directions according to the ASTM D-882 method into five strips of width 2.5 cm and length 20 cm. The average values of transverse and longitudinal tensile strength and elongation of the five strips were obtained by a universal tensile testing machine.

Peel Strength: Each of the sheets of Examples 1 to 5 and Comparative Examples 1 to 6 was evaluated according to the method listed below.

Method 1: A notch is formed on the sheet by cutting, and then a semicircular portion (about 5 cm ² ) is obtained by tearing off the sheet from the notch. The semicircular part is weighed. The greater the weight of the half-circle, the more the conductive surface layer will be stripped away. This reflects the compatibility between the conductive surface layer and the substrate layer.

制造的TP-1000)将其密封到封盖膜。称重所述封盖膜上的导电表面层的剩余物。剩余物的重量越大，剥离的导电表面层也就越多。这反映了导电表面层与衬底层之间的兼容性。Method 2: Strips with a width of 25 mm and a length of 1 m were prepared from the sheets of Examples 1 to 5 and Comparative Examples 1 to 6, and passed through a sealing machine at a sealing temperature of 240° C. and a pressure of 40 psi (by

Manufactured TP-1000) seal it to the lidding film. The remainder of the conductive surface layer on the lidding film was weighed. The greater the weight of the residue, the more the conductive surface layer will be stripped. This reflects the compatibility between the conductive surface layer and the substrate layer.

The results are listed in Tables 2 and 3:

Table 2:

According to Table 2, the surface resistivities of Examples 1 to 5 are almost the same as those of Comparative Examples 2 to 5 because the carbon black content is the same (16.67 wt%).

Examples 1 and 2 did not contain (D) styrene-butadiene copolymer, and their elongation was lower than that of Examples 3 to 5. Compared with Comparative Example 2, Example 1 was added with 5% by weight of the copolymer (B) containing an olefin block and an enolate block, and seal strength and peeling were improved. As the copolymer (B) comprising olefin block and enolate block was added in Examples 2 to 5, the seal strength was significantly increased. However, an excessive amount of copolymer (B) (for example, in Example 5) results in excessively high sealing strength (over 90 g), which would interfere with unpacking electronic parts packaged in a packaging container made of a sheet. The compatibility of Examples 1 to 5 is better than that of Comparative Examples 3 to 6.

While various embodiments of the invention have been illustrated and described, various modifications and improvements will occur to those skilled in the art. It is intended that the invention not be limited to the particular forms as illustrated and that all modifications which do not depart from the spirit and scope of the invention come within the purview of the appended claims.

Claims (20)

1. conductive plastic composites, it comprises:

(A) comprise the multipolymer of styrene block and acrylate block;

(B) comprise the multipolymer of olefin block and olefin(e) acid ester block; And

(C) carbon black;

Described composition is for the described multipolymer that comprises styrene block and acrylate block of per 100 weight parts

(A) contain the described multipolymer (B) that comprises olefin block and olefin(e) acid ester block of 5 to 40 weight parts; And the described carbon black (C) that contains 5 to 35 weight parts for the described multipolymer (A) that comprises styrene block and acrylate block of per 100 weight parts.

2. composition according to claim 1, the wherein said multipolymer (A) that comprises styrene block and acrylate block comprise 10 to 80wt% styrene block.

3. composition according to claim 1, the wherein said acrylate block that comprises the multipolymer (A) of styrene block and acrylate block is selected from the group that is made up of and the following: acrylate, methacrylic ester, methyl methacrylate, butyl acrylate, vinyl cyanide and its mixture.

4. composition according to claim 1, the wherein said multipolymer (A) that comprises styrene block and acrylate block further comprises diene block.

5. composition according to claim 1, the wherein said multipolymer (A) that comprises styrene block and acrylate block is selected from the group that is made up of and the following: styrene-methylmethacrylate copolymer, styrene butadiene-methylmethacrylate copolymer, styrene butadiene-butyl acrylate copolymer, styrene butadiene-methyl methacrylate-acrylonitrile copolymer and its mixture.

6. composition according to claim 1, the wherein said olefin block that comprises the multipolymer (B) of olefin block and olefin(e) acid ester block is an ethene.

7. composition according to claim 1, the wherein said olefin(e) acid ester block that comprises the multipolymer (B) of olefin block and olefin(e) acid ester block is selected from the group that is made up of and the following: butyl acrylate, methacrylic ester, vinyl acrylate and its mixture.

8. composition according to claim 1, the wherein said multipolymer (B) that comprises olefin block and olefin(e) acid ester block is selected from the group that is made up of and the following: ethylene-propylene acid butyl ester, ethylene-methyl acrylate, ethylene-propylene vinyl acetate and its mixture.

9. composition according to claim 1, its described multipolymer (A) that comprises styrene block and acrylate block for per 100 weight parts contains the described multipolymer (B) that comprises olefin block and olefin(e) acid ester block of 20 to 30 weight parts.

10. composition according to claim 1, wherein said carbon black (C) is selected from the group that is made up of and the following: furnace black, channel black, super conducting furnace black and conductive furnace black.

11. composition according to claim 1, it further comprises (D) styrene-butadiene copolymer, ethane-acetic acid ethyenyl ester or chlorinatedpolyethylene.

12. composition according to claim 1, it further comprises additive.

13. composition according to claim 12, wherein said additive is selected from the group that is made up of and the following: lubricant, plasticizer, processing aids, toughener and in order to other resinous principle of the kinetic characteristic of the flow characteristics of improving described composition and moulded product with and composition thereof.

14. a conductive plastics thin slice, it comprises composition according to claim 1.

15. conductive plastics thin slice according to claim 14, it has 10 ²To 10 ⁸The surface resistivity of Ω.

16. a conduction composite plastic thin slice, it comprises substrate layer and is laminated to conductive surface layer at least one side of described substrate layer, and wherein said conductive surface layer comprises composition according to claim 1.

17. conduction composite plastic thin slice according to claim 16, wherein said substrate layer is selected from the group that is made up of and the following: acrylonitrile-butadiene-styrene (ABS), polystyrene and polycarbonate.

18. conduction composite plastic thin slice according to claim 17, wherein said substrate layer is an acrylonitrile-butadiene-styrene (ABS).

19. a packaging container, it comprises conduction composite plastic thin slice according to claim 16 and capping film.

20. conduction composite plastic thin slice according to claim 19, wherein said capping film are poly-(ethylene glycol terephthalate) films.