JPS61223041A - Molded article of electrically-conductive resin and material thereof - Google Patents

Abstract

PURPOSE:The titled molded article useful as Venetian blinds, or containers, having electrical conductivity in all directions, randomly and uniformly dispersed electrically-conductive fibers, and improved surface state, obtained by blending specific amounts of resin with electrically-conductive fibers and an electrically- conductive scaly material. CONSTITUTION:100pts.wt. resin (preferably modified polyolefin which is partially or totally grafted with an unsaturated carboxylic acid compound and/or an organosilane compound) is blended with (A) 3-30pts.wt. preferably 5-20pts.wt. electrically-conductive fibers of stainless steel fibers having preferably 2-20mu diameters and 0.5-3mm average fiber length), (B) 5-50pts.wt., preferably 5-35pts.wt. metallic scaly material or scaly filler subjected to surface coating with a metal (nickel-coated mica having preferably 20-1,400mu average diameter and 20-90 average aspect ratio), (C) 0-120pts.wt., preferably 0-100pts.wt. flame-retardant, and (D) 0-40pts.wt. agent for providing synergistic effect with the flame retardant. The blend is kneaded, pelletized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to conductive resin products and conductive resin pellets, which are intermediate products thereof.

[Conventional technology]

Various electronic devices are used in automobiles and various home appliances, and each electronic device emits high-frequency or low-frequency radio waves, which become a source of radio wave interference and have an adverse effect. As a countermeasure to this problem, a metal plate (box) was used to cover (contain) the electronic device that was the source of the emission, and it was also effective in terms of shielding electromagnetic waves.

However, metal plates (boxes) are gradually being replaced by thermoplastic resin containers, and conventionally this has been handled by applying a conductive substance to the thermoplastic resin containers. However, coatings of conductive materials such as nitrates have poor durability and are often very costly.

It is also well known to mix conductive fibers or conductive fillers into resins in order to improve electrical and thermal conductivity.

[Problems to be Solved by the Invention] However, in many cases, conductive fibers alone cannot provide sufficient conductivity unless they are filled in a relatively large amount. Furthermore, when the molded product is cut into pieces and reused as molding material in order to reduce costs, the fibers are shredded during molding and the aspect ratio (length/diameter) is extremely reduced, resulting in an extremely low conductivity. There are many things to do.

Further, if a conductive filler is used alone, good conductivity cannot be obtained unless it is filled in a large amount, and if a large amount is filled with a conductive filler, the mechanical properties of the resin product (molded article) will be significantly reduced.

[Means for solving problems]

The present inventors completed the present invention as a result of intensive research to solve the above problems.

That is, 9 the present invention uses 100 parts by weight of resin and 3 parts by weight of conductive fibers.
~30 parts by weight, 5 to 50 parts by weight of a metal flake or a scaly filler whose surface is coated with metal, and 0 to 120 parts by weight of a flame retardant.
Parts by weight preferably 5 to 100 parts by weight and 0 parts by weight of flame retardant synergist
-40 parts by weight, conductive in all directions, conductive fibers are randomly and substantially uniformly distributed, and scaly matter is suppressed from extruding onto the surface and peeling off. It is about things.

9 In addition, the present invention includes 100 parts by weight of resin and 5 to 5 parts by weight of conductive fiber.
30 parts by weight and 5 to 50 parts by weight of a scaly filler whose surface is coated with a metal scaly material or metal.

The present invention relates to conductive resin pellets which are intermediate products for conductive resin products comprising 0 to 120 parts by weight of a flame retardant, preferably 5 to 100 parts by weight, and 0 to 40 parts by weight of a flame retardant synergist.

The resins used in the present invention include ABS, HIP8 (high impact polystyrene/), and polyamide.

For example, nylon 6, nylon 66, nylon 12, etc.
Examples include lnyl (modified PP0), PBT, PC (polycarbonate resin), polyolefin resin, and the like. The polyolefin resin is preferably a modified polyolefin resin in which part or all of the polyolefin resin is graft-modified with an unsaturated carboxylic acid compound and/or an organic silane compound. By using a modified polyolefin resin, embossment and peeling of scale-like substances on the surface of the molded product can be greatly suppressed.

Examples of the polyolefin resin include crystalline homopolymers of propylene, propylene and ethylene, or other α-olefins (e.g., butene-1°pentene, hexene,
Heptene, octene-1, etc.) and crystalline random or block copolymers with propylene and ethyl/thi/and other α
- Polypropylene resins such as crystalline terpolymers with olefins, homopolymers of ethylene with a density of 0.939/aA or more, copolymers of ethylene with α-olefins, etc., and blocks of propylene and ethylene. Copolymers are preferred. The melt flow rate index (VFR) of polyolefin resin is 0.1 to 100f/1
0 minutes [: ASTM D1238, 23σ (:', 21
60f, the same applies hereafter] is better or less. The organic silane compounds include vinyltriethoxysilane, methacryloyloxytrimethoxysilane, r-methacryloyloxypropyltrimethoxysilane, methacryloyloxycyclohexyltrimethoxysilane, r-methacryloyloxypropyltriacetyloxysilane, methacryloyloxytriethoxysilane, Examples include r-methacryloyloxypropyltriethoxysilane. These organic silane compounds may be used alone or in combination of two or more.

The modified polyolefin resin is obtained by grafting a part or all of the polyolefin resin described above and the organic silane compound, preferably in the presence of an organic peroxide. As the organic peroxide mentioned above.

Those having a 1-minute half-life temperature of about 160 to 260°C are preferred, such as tert-butyl peroxyisopropyl carbonate, di-tert-butyl civa-oxyphthalate, tert-butyl peroxyacetate), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 25-dimethyl-2,5-
Di(tert-butylperoxy)hexyne-6, tert-butyl peroxylaurate, tert-butyl peroxymaleic acid, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, cyclohexanone peroxide.

Examples include tertiary-butylcumyl peroxide, 2,5-dimethylhexane, 2,5-cybide lobaroxide, and the like. These organic peroxides may be used alone or in combination of two or more.

The modified polyolefin resin is preferably a polyolefin resin, particularly a block copolymer of propylene and ethylene 10.
0 parts by weight, 0.01 to 5 parts by weight of the organosilane compound, especially 0.05 to 3 parts by weight, and 0.01 to 3 parts by weight of the organic peroxide.
5 parts by weight, especially 0.05-2 parts by weight, and the resulting mixture is heated at 160-270°C, especially 180-270°C.
It can be obtained by grafting by heating to a temperature of . A simple heat treatment operation is to extrude and melt-heat the mixture at the temperature for about 1 to 10 minutes. Especially as a modified polyolefin resin, MFR is 5 to 80f.
/10 minutes modified propylene-ethylene block copolymer is preferred.

The modified polyolefin resin may be used alone or in combination with a modified polyolefin resin and an unmodified polyolefin resin.

Furthermore, a modified polyolefin graft-modified with unsaturated carboxylic acids can also be used as the modified polyolefin resin. Examples of unsaturated carboxylic acids as monomers to be grafted include maleic anhydride, itaconic anhydride,
Acrylic acid is preferably mentioned. Graft modification (reaction)
The introduction of the unsaturated carboxylic acid group is not particularly limited, and can be carried out by a conventional method such as a solution method using an organic peroxide or the like or a crosstalk method. Examples of organic peroxides include those used for graft modification with the aforementioned organic silane compounds. It is preferable to graft-modify the unsaturated carboxylic acids in a proportion ranging from 0.05 to 13.5% by weight based on the polyolefin resin. Other reaction conditions and specific reaction operations regarding the graft modification (reaction) of the polyolefin resin can be easily set according to methods known per se. After completion of graft modification (reaction).

The graft-modified polyolefin resin can be obtained by a method known per se. The modified polyolefin resin may be used alone or in combination with an unmodified polyolefin.

In the present invention, the conductive fibers include stainless steel x fibers,
Examples include nickel-coated carbon fiber, nickel-coated glass fiber, chatty aluminum fiber, and chatty brass fiber, and stainless steel fiber is preferred from the viewpoint of conductivity and fiber dispersibility. Stainless fibers are especially suitable for cut lengths of 2.5~
7.5 It is preferable to use briefly cut bundled stainless steel fibers during compounding, and the thickness of the stainless steel fibers should be 2 to 20 μm.
In particular, 2 to 15 μm is preferable. The bundled stainless steel fibers are preferably those in which 1000 to 500 stainless steel fibers are bundled with a binding polymer. A solvent-soluble polymer is preferably used as the focusing polymer.

An example of such a polymer is vinyl acetate copolymer.

Ethylene-vinyl acetate copolymer (EVA) and saturated polyester copolymer are preferably used, but are not limited thereto. As a focused stainless fiber, the adhesion amount is 1
~20% by weight of stainless steel fibers bound with the above-mentioned binding polymer are preferably used.

In addition, conductive fibers are included in the resin product with 0.5 to 311aI.
It is preferable that the fibers remain at an average fiber length of I.

Examples of the conductive scaly materials used in the present invention include metal scaly materials such as aluminum flakes and nickel flakes, and scaly fillers whose surfaces are coated with metals such as nickel-coated mica and nickel-coated graphite. Mica is preferred. In this invention, the average diameter of the nickel-coated mica is preferably from 20μ to 1400μ, preferably from 80μ to 650μ, and from 150μ to 44μ.
0μ is particularly preferred. The average aspect ratio (average diameter/average thickness) of nickel-coated mica is between 20 and 90, and 3
0 to 90 is preferred, and 40 to 70 is particularly preferred.

If the average diameter is 80μ or less and the aspect ratio is 30 or less, the plastic product will not have sufficient electrical conductivity, and if the average diameter is 650μ or more, the surface condition of the plastic product will not be good. The conductive scale-like material may be surface-treated with the organic or silane compound.

When flame retardance is the objective, a flame retardant 9, such as a brominated flame retardant, preferably a decabromidiphenyl flame retardant, and a flame retardant synergistic agent are blended. Examples of the decabromidiphenyl flame retardant include decabromidiphenyl ether and decabromidiphenyl. Moreover, antimony trioxide can be suitably used as a flame retardant synergistic agent.

In the present invention, the blending ratio of each of the above components is preferably 100 parts by weight of the modified polyolefin resin partially or completely graft-modified with the flame retardant, preferably 0 to 120 parts by weight of the decabromodiphenyl flame retardant (preferably 5-1
00 parts by weight, particularly preferably 20 to 60 parts by weight), 0 to 40 parts by weight (preferably 0 to 30 parts by weight) of a flame retardant synergist, and 3 to 3 parts by weight of conductive fibers, preferably 5 to 20 parts by weight. , 5 to 50 parts by weight of conductive scales, preferably 5 to 50 parts by weight
The amount is 35 parts by weight.

In the present invention, in addition to the conductive fibers, the conductive scales, the flame retardant, and the synergistic flame retardant, the resin composition may also contain metal powder, carbon black, and the like. Furthermore, in the present invention, additives necessary for the resin such as lubricants, plasticizers, antioxidants, and ultraviolet absorbers can also be added to the resin composition.

In the present invention, there is no particular restriction on the order of blending each component, but when the decabromodiphenyl flame retardant is used, the resin preferably is a modified polyolefin resin obtained by graft-modifying some or all of the above and the above flame retardant. Preferably, a flame retardant synergistic effect agent is first mixed in a predetermined ratio, preferably pelletized, and this mixture (preferably the pellets), the conductive fibers, and the conductive scales are mixed (
Usually, it is preferable to mix the resin at a temperature that is higher than the melting temperature and lower than the decomposition temperature of the modified polyolefin resin, and after the cross-crossing, it is pelletized and molded. There are no particular restrictions on the shape of the pellets, and usually 2~4111111'6+3~
It is pelletized into 7 mm (L) cylindrical or square shapes.

The electrically conductive resin product of the present invention is produced by molding the pelletized electrically conductive resin composition as described above, preferably by injection molding, extrusion molding, compression molding, foam molding, etc., preferably by injection molding. Plates, sheets, such as armor plates, side sections of various shapes, etc., have a random and almost uniform distribution of conductive fibers, and reduce the appearance and peeling of scale-like objects on the surface. 9 It is molded as a box, cover, and other contents.

Examples of the present invention are shown below. In the following, parts and % each represent parts by weight of 1% by weight.

□ [Example] Example I 0.5 part of maleic anhydride and 0.15 part of t-butyl peroxybenzoate are added to 100 parts of a crystalline ethylene-propylene block copolymer with an MFR of IP/10 minutes and an ethylene content of 7. were mixed in a tumbler and melt-kneaded for 2 minutes at 200°C in a screw extruder to obtain modified polypropylene graft-modified with maleic anhydride (MPP-1).
) Obtained from this modified polypropylene (MPP-1)
20 copies.

80 parts of a crystalline ethylene-propylene block copolymer with an MFR of 15 f/10 minutes and an ethylene content of 7%.

Decabromodiphenyl ether per 100 parts total
Product name: DP-10F Marubishi Yuka Kogyo ■] 56 parts, antimony trioxide 24 parts were added to flame-retardant modified polypropylene, which was mixed and milleted, and vinyl acetate copolymer [Product name: X-
8 μ (1 piece) , 1 nickel-coated mica [Product name: Conductive mica EC-150 Kuraray ■]
Cross-wire in a kneader at a rate of 5% (180°C, 6 minutes,
24 r, pm, ) L pellets (4m121X4~5
M) was obtained.

Injection mold this pellet with 220 1 + machine 80Z)
A molded flat plate in the order of L 15ctnX 153X was obtained.

The appearance of this molded flat plate is an embossed nickel-coated mica,
The appearance is good with no peeling observed, and the conductivity is as low as the volume resistivity (
MD and TD are almost the same) is 6.7 x 10''''1cWL
, the shielding effectiveness was 43 dB at 300 MHz. This confirmed that it had conductivity in all directions and that the fibers were randomly and uniformly distributed. The average fiber length of the stainless steel fibers dispersed in the molded flat plate at this time was 1.2 lin, and the flame retardancy was (UL-94) V-
It was 0.

Example 2 Saturated polyester as focused stainless fiber [Product name:
Uses focused stainless steel fibers to which 10 pieces of Elythyl UIC-3210 Unideca ■ are attached.

A molded flat plate was obtained in the same manner as in Example 1 except that the mixture was kneaded at 180° (ll') for 5 minutes at 24 rpm.The appearance of this molded flat plate was good with no embossment or peeling of the nickel-coated mica, and the conductivity was good. Volume resistivity is 8.9×10-'nc
m shielding effectiveness was 41 dB at 300 MHz. The average fiber length of the stainless steel fibers dispersed in the molded flat plate at this time was 11111 + flame retardancy (UL-94) was VO.

Example 6 EVA as focused stainless fiber (product name: Sumichi)
KA-10, Sumitomo Chemical ■] 7 pieces of focused stainless fiber with 5 pieces attached, nickel coated? (Power (EC!-15
0) 10% O ratio A molded flat plate was obtained in the same manner as in Example 1 except that the mixture was kneaded in a teneter (180°C, 3 minutes + 24 rpm). The appearance of this molded flat plate is good with no embossment or peeling of the nickel-coated mica, and the conductivity is 4.9X with a volume resistivity of 4.9X 10 Atx shielding effect of 300M
It was 46 dB at Hz. At this time, the average fiber length of the stainless steel fibers dispersed in the molded flat plate was 1.3 ml, and the flame retardancy (UL-94) was V-O.

Example 4 Vinyl acetate copolymer as focused stainless steel fiber [Product name: X
-I, imk Kanebo] 7 pieces of focused stainless fiber attached with 10 pieces, 10% of nickel-coated mica EO-150
Cross-wire in a kneader at a ratio of (180°C, 96 minutes, 24 rpm)
A molded flat plate was obtained in the same manner as in Example 1 except for m) and l.

The appearance of this molded flat plate is an embossed nickel-coated mica,
Good conductivity with no peeling observed and volume resistivity of 6. O
X 10-'ρcm shielding effectiveness is 4 at 300 MHz
It was 2dB. At this time, the average fiber length of the stainless steel fibers dispersed in the molded flat plate was 1.1. Flame retardant (Ul, -
94) was V-O.

[Comparative example]

Comparative Example 1 A molded flat plate was obtained in the same manner as in Example 1 except that 15 g of nickel-coated mica E (!-150 was added and no focused stainless fibers were added.The appearance of this molded flat plate was similar to that of nickel-coated mica. The conductivity was good with no embossment or peeling observed, but the volume resistivity was unmeasurable (10' A-
an or more).

Comparative Example 2 Nickel coated mica EC! A molded flat plate was obtained in the same manner as in Example 1, except that 25 g of -150 was added and the bundled stainless steel fibers were not added. The external appearance of this molded flat plate showed a very small amount of embossment of the nickel-coated mica, and the volume resistivity of the conductivity was unmeasurable (104 fLcrn or more).

Example 5 MFR is 9 g! /10 minutes, 10.5 parts of r-methacryloyloxypropyltrimethoxysila, and 0.5 parts of t-butyl peroxybenzoate were added to 100 parts of crystalline ethylene-propylene block copolymer with an ethylene content of 7. Mix 25 parts in a tumbler, -
Modified polypropylene (MFFIO (1/1
(MPP-2) was obtained (0 min) in air.

A molded flat plate was obtained in the same manner as in Example 1, except that modified polypropylene (MPP-2) graft-modified with the organosilane compound was used as the modified polypropylene. The appearance of this molded flat plate was good with no embossment or peeling of the nickel-coated mica, and the conductivity was 5.5% in volume resistivity. OX
10-! 12m + shield effect is 4 in S 00 MH2
It was 4 dB. The average fiber length of the stainless steel fibers dispersed in the molded flat plate at this time was 1.21EII, and the flame retardancy was (Ul, -94)V-0.

Example 6 Modified polypropylene (MPP-2) graft-modified with the organosilane compound was used as the modified polypropylene, and 5 pieces of KVA [trade name: Sumitate KA-10゜Sumitate Kagaku Kogyo ■] were attached as the bundled stainless fibers. 7 pieces of focused stainless steel fibers, nickel-coated mica (PC-
150) Kneaded in a kneader at a ratio of 10 cm (180°C3
A molded flat plate was obtained in the same manner as in Example 1, except that the molding speed was 24 rpm). The external appearance of this molded flat plate showed that the nickel-coated magnetic effect was 47 dB at 300 MHz. At this time, the average fiber length of the stainless steel fibers dispersed in the molded flat plate is 1.
35 m, flame retardancy (Ul, -94) was V-○.

It was confirmed that the molded flat plates of Examples 2 to 5 also had conductivity in all directions, and that the fibers were randomly and substantially uniformly distributed.

〔Effect of the invention〕

According to the present invention, by blending a small amount of conductive fibers and conductive scales, a resin product with good conductivity and a good surface condition can be obtained.

Claims (7)

[Claims] (1) 100 parts by weight of resin, 3 to 30 parts by weight of conductive fiber, 5 to 50 parts by weight of a metal scale or a scaly filler whose surface is coated with metal, and 0 to 120 parts by weight of a flame retardant, preferably 5 to 100 parts by weight. parts by weight and 0 to 40 parts by weight of a flame retardant synergistic effect agent, has conductivity in all directions, has a random and substantially uniform distribution of conductive fibers, and does not cause scale-like objects to rise to the surface or peel off. A conductive resin product that is suppressed. (2) The conductive resin product according to claim 1, wherein the resin is a modified polyolefin resin partially or entirely graft-modified with an unsaturated carboxylic acid compound and/or an organic silane compound. (3) The conductive resin product according to claim 1, which is manufactured using an injection molding machine. (4) The conductive resin product according to claim 1, which is formed into a plate or sheet. (5) The scale-like filler whose surface is coated with metal is nickel-coated mica having an average diameter of 20 to 1400μ and an average aspect ratio (average diameter/average thickness) of 20 to 90. 4. The conductive resin product according to item 4. (6) The conductive resin product according to any one of claims 1 to 5, wherein the conductive fibers are stainless steel fibers having a diameter of 2 to 20 μm and an average fiber length of 0.5 to 3 mm. (7) 100 parts by weight of resin, 3 to 30 parts by weight of conductive fiber, 5 to 50 parts by weight of a metal scale or a scaly filler whose surface is coated with metal, and 0 to 120 parts by weight of a flame retardant, preferably 5 to 100 parts by weight. A conductive resin pellet, which is an intermediate product for a conductive resin product, comprising parts by weight of a flame retardant synergist and 0 to 40 parts by weight of a flame retardant synergist.