JPS60120743A - Electromagnetic wave shielding resin composition having flame retardance - Google Patents

Abstract

PURPOSE:To provide a resin compsn. excellent in an electromagnetic wave shielding effect, mechanical properties, and flame resistance, by incorporating a particular copolymer, phosphoric acid derivative, carbon fiber, halogen-contg. org. flame retardant, and flame retardant auxiliary. CONSTITUTION:40-70wt% ethylenically unsatd. nitrile/diene rubber/arom. vinyl copolymer (e.g., acrylonitrile/butadiene/styrene copolymer) or mixture of ethylenically unsatd. nitrile/arom. vinyl copolymer therewith, 1-10wt% phosphoric acid derivative (e.g., tricresyl phosphate) as a flame retardant plasticizer, 5- 40wt% carbon fiber, 5-35wt% halogen-contg. org. flame retardant (e.g., tetrabromobisphenol A), and 1-21wt% flame retardant auxiliary (e.g., Sb2O3) are incorporated so that component E is 6/10-2/10 of component D.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an electromagnetic wave shielding resin composition comprising a comonomer, a flame retardant, carbon fiber, and a plasticizer, which has particularly good electromagnetic wave shielding effects and mechanical properties, and is highly flame retardant. The present invention relates to a resin composition.

2. Description of the Related Art Conventionally, electronic devices such as office equipment, computers, and TV receivers themselves are sources of electromagnetic waves, causing malfunctions and noise in surrounding electronic devices.

On the other hand, these electronic devices are affected by electrical devices installed nearby, and may malfunction or generate noise themselves.

The casings of these electronic devices have been shielded from electromagnetic waves to some extent.

However, in recent years, ease of molding, free design,
Plastic materials are widely used in the housings of electronic devices due to their light weight and other advantages.

Plastic materials generally have poor conductivity and have almost no ability to shield electromagnetic waves, so when using plastic materials for the housing of electronic devices, shielding treatment against electromagnetic waves is required.

In particular, recently, strict restrictions have been placed on the radiation of electromagnetic waves from electronic devices, both domestically and internationally, and there is an increasing demand for electromagnetic wave shielding treatments for plastic materials.

On the other hand, when plastic materials are used for the housings of these electronic devices, UL
Standards such as the C8A standard require that plastic materials be made flame retardant.

7. A known method for making durable materials flame retardant is to mix a flame retardant and a flame retardant aid with a flame retardant. Moreover, when used in combination with a flame retardant aid such as antimony trioxide, a mutually beneficial effect is expected.

However, standard standards for flame retardancy, such as UL
In order to pass the vertical combustion test of No.-94, it was necessary to add a large amount of these flame retardants and flame retardant aids, so the thermal and mechanical properties of the molded products were poor.

In addition, especially when a conductive filler such as carbon fiber is mixed into the resin as a shielding treatment against electromagnetic waves,
As the thermal conductivity of the resin improves, the flame retardancy decreases, so it is necessary to add a larger amount of flame retardant or flame retardant aid, and the thermal and mechanical properties of the molded product are completely inferior. It was something.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have found that a flame-retardant electromagnetic wave made of a copolymer, carbon fiber, and... By adding a flame retardant plasticizer made of a phosphoric acid derivative to the shielding resin composition, sufficient flame retardancy can be achieved with the addition of a small amount of flame retardant or flame retardant aid, and the thermal The present invention was completed based on the new finding that an electromagnetic wave shielding resin composition with good properties and mechanical properties can be obtained.

That is, the present invention provides: (1) Ethylenically unsaturated nitrile-diene rubber-aromatic vinyl copolymer N8 or a mixture thereof with ethylenically unsaturated nitrile-aromatic vinyl copolymer 40-70% by weight (2) Phosphorus Flame retardant plasticizers 1 to 10 consisting of acid derivatives: i
', t% (3) carbon fiber 5-40% by weight) halogen-containing organic flame retardant 5-35% by weight (5) flame retardant aid 1-21M amount.

The base resin of the electromagnetic wave shielding resin composition having flammability of the present invention is an ethylenically unsaturated nitrile-diene rubber-aromatic vinyl copolymer or an ethylenically unsaturated nitrile-aromatic vinyl copolymer with this copolymer. A mixture of

The ethylenically unsaturated nitrile compound in the present invention includes, for example, acrylonitrile, methacrylonitrile, ethacrylonitrile, methylmethacrylonitrile, and the like, with acrylonitrile and methacrylonitrile being particularly preferred.

The diene rubber in the present invention includes one or more conjugated 1,6-dienes, such as sitadiene, isofurene, 2-chloro-1,3-7"tadiene, 1-chloro-
Any rubber compound such as 1,3-butadiene and piperylene may be used, but butadiene is particularly preferred.

The aromatic vinyl compounds in the present invention include styrene, α
- Means methylstyrene, vinyltoluene, divinylbenzene, chlorostyrene, etc., singly or in mixtures, among which styrene alone gives better results in the present invention.

Furthermore, the ethylenically unsaturated nitrile-dienecomb-aromatic vinyl copolymer of the present invention includes an ethylenically unsaturated nitrile compound and A polymer grafted with 80 to 25 parts by weight of a mixture of aromatic vinyl compounds is preferred.

On the other hand, when using a mixture of the ethylenically unsaturated 2)IJ ludiene rubber-aromatic vinyl copolymer and the ethylenically unsaturated 2[.liru aromatic vinyl copolymer, the ratio is such that the former is 25 to 99 parts by weight. , the latter is preferably in the range of 1 to 75 double dobes. These manufacturing methods are described, for example, in Japanese Patent Publication No. 1983-
No. 37675 is mentioned.

Next, the carbon fiber used in the present invention is a mixture of one or more selected from the group of polyacrylonitrile carbon fiber, pitch carbon fiber, and phenol carbon fiber, and among them, polyacrylonitrile carbon fiber, pitch carbon fiber, and phenol carbon fiber are used. When acrylonitrile carbon fiber is used alone, a particularly good electromagnetic wave shielding effect can be obtained.

The carbon fiber content is 5 to 40'li, preferably 10 to 25 m, and if the added amount is less than 5% by weight, almost no electromagnetic wave shielding effect can be obtained, and the amount added is less than 5% by weight. If it exceeds 40% by weight, extrusion molding and injection molding will be difficult, and the mechanical properties of the molded product will also be poor.

The halogen-containing organic flame retardants used in the present invention include chlorinated paraffin, tetrabromobisphenol A1 and its oligomer, decabromobiphenyl ether, hexabromobiphenyl ether, pentabromobiphenyl ether, pentazolomotoluene, pentabromoethylbenzene, and hexabromobiphenyl ether. Bromobenzene, pentabromophenol,
Tripro%7:r:, /-ru derivative, perchloropentanecyclodecane, hexabromocyclododecane,
Tris-(2,3-diglomozolovir-1)-in cyanurate, tetrabromobisphenol S and its derivatives, 1,2bis(2,3,4,5,6-pentabromophenoxy)ethane, 1.2bis(2 ,4゜6-tribromophenoxy)ethane, brominated styrene oligomer, 2,
2-bis-(4-(2,3-dibromopropyl)-3,
'5 dibromophenoxy)propane, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, etc.

The kinetic aids used in the present invention are antimony trioxide, sorta antimonate, zinc olate, zircon, and molybdenum oxides or sulfides, although antimony trioxide gives the best results. give.

The degree of flammability of the halogen-containing organic flame retardant varies depending on the required degree of flame retardancy and the amount of flame retardant plasticizer made of a phosphoric acid derivative, but it is from 5 to 65, preferably from 10 to 20. .

If the amount of the halogen-containing flame retardant added is less than 5% by weight, a sufficient flame retardant effect cannot be obtained, while if the amount added exceeds 65% by weight, the thermal and mechanical properties of the molded product will be poor. becomes.

Furthermore, the amount of flame retardant aid added is 1 to 21% by weight,
Moreover, the content of the rogen-containing organic flame retardant is in the range of 'Ao to 2AO%, preferably %0 to %0. Addition amount of flame retardant aid is 1
If it is less than 21% by weight, the flame retardant effect due to the interaction with the flame retardant will be insufficient, and if it exceeds 21% by weight, the mechanical properties of the molded article will deteriorate.

Moreover, the added amount of flame retardant aid is 2A of halogen-containing organic flame retardant.
If it is less than o, the flame retardant effect due to the mutual effect with the halogen-containing organic flame retardant is insufficiently expressed, and a sufficient flame retardant effect cannot be obtained, and on the other hand, the amount added exceeds '/io of the halogen-containing organic flame retardant. This results in inferior mechanical properties of the molded product.

Furthermore, flame-retardant plasticizers made of phosphoric acid derivatives used in the present invention include tri(2-ethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate,
Tricythoxyethyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, indecyl diphenyl phosphate, tricresyl phosphate, tricylenyl phosphate, mixed allyl phosphate, phenyl/isopropyl phenyl phosphate, mixed triallyl phosphate, tris (chloroethyl)phosphate, especially 2
-Ethylhexyl diphenyl phosphate and tricresyl phosphate, each alone or in combination, give good results.

The amount of flame retardant plasticizer made of phosphoric acid derivative is 1 to 1.
0% by weight, preferably 2 to 8% by weight; if the amount added is less than 1% by weight, a sufficient flame retardant effect cannot be obtained when the addition of a small amount of the rodene-containing organic flame retardant and flame retardant aid; Moreover, it is not possible to obtain a molded article with good thermal stability during molding or mechanical properties of the molded product.

On the other hand, the amount added is 10! If it exceeds i%, a molded article with good thermal and mechanical properties cannot be obtained.

Furthermore, processing aids such as antioxidants, stabilizers, internal lubricants, external lubricants, etc. can be added to improve the performance of the resin compositions of the present invention.

Next, in the method for producing the resin composition of the present invention, first, powdery
Ethylenically unsaturated nitrile-diene rubber-aromatic vinyl copolymer in various shapes such as beads and pellets, or mixtures thereof with ethylenically unsaturated >U nitrile-aromatic vinyl copolymers in various shapes; It consists of longitudinal fibers, a flame retardant, a flame retardant aid, and a flame retardant plasticizer, but from the viewpoint of moldability and physical properties of molded products, ethylene-unsaturated nitrile-diene rubber is used.
It is more preferable to use the aromatic vinyl copolymer in powder form and the ethylenically unsaturated nitrile-aromatic vinyl copolymer in bead form. In order to make the composition of the present invention uniform, mixing and kneading may be carried out in a mixing machine or extruder such as a Banbury mixer, a co-kneader, a screw extruder, a twin-screw extruder, or a mixing machine. Before mixing and kneading in an extruder, preliminary mixing may be performed using a means such as a tumbler-1 high-speed mixer.

The resin composition obtained by performing this mixing and cross-mixing is supplied into the hopper of an injection molding machine, melted in a plasticizing cylinder, injected into an injection mold, and cooled and solidified in the mold to produce a molded product. By taking out the resin composition of the present invention, an injection molded article can be obtained.Similarly, the resin composition is fed into the hopper of an extrusion molding machine, melted in the plasticizing cylinder, and then An extrusion molded article using the resin composition of the present invention can be obtained by extrusion through a die installed at the tip.The present invention will be described in detail below with reference to Examples and Comparative Examples.

Examples 1 to 8 Resin (composition ratio: 10% by weight of acrylonitrile)
Powdered acrylonitrile-butadiene-styrene copolymer resin (ABS resin) consisting of 501% polygetadiene, 40M1 styrene, and beaded acrylonitrile-styrene copolymer resin consisting of 30% acrylonitrile and 70% styrene. (As resin) f/ was used, the carbon fiber was a chopped strand of polyacrylonitrile carbon fiber manufactured by Toho Rayon Co., Ltd. under the trade name "Besphite HTAC6SJ", and the halogen-containing organic flame retardant was tetrabromobisphenol A. Banjin Kasei Co., Ltd. Product name: “Fire Guard 2D”
Using DOj, as a flame retardant aid, Nippon Mining Co., Ltd.,
Antimony trioxide was used.

Furthermore, as flame retardant plasticizers made of phosphoric acid derivatives,
Oiri Kagaku Co., Ltd.'#J1 tricresyl phosphate was used.

Further, an antioxidant, a stabilizer consisting of tribasic lead, and zinc stearate were added to this, and the composition was blended as shown in the table, and the mixture was heated in a Banbury mixer heated to 140'O.
The mixture was melted and kneaded, and when the mixture reached 190'O, it was taken out, immediately cooled into a sheet shape using a mixing roll, and crushed into pellets.

The pellets are fed into the hopper of an 8 ounce injection molding machine, melted in a 0J' plasticizing cylinder, and injected into an injection mold.

The injection mold had a casing shape of 15 cTL square with a thickness of ψ, and the r-t was a direct date with a diameter of 2 fins φ.

The molded article thus obtained had excellent mechanical properties, heat resistance, and electromagnetic shielding effect.

Example 9 The composition shown in the table was pelletized in the same manner as in Example 1, and then pelletized using an extruder with a diameter of 4Dψ (VD = 24
> is fed into a hopper, melted and fed to a single layer sheet die at 200°C.

The width of the die was adjusted to 600 dam, and the lip was adjusted to 6.5 dam, and as a result, a single layer sheet with a thickness of 3 my'm was obtained.

As shown in the table, the obtained single-layer sheet had excellent mechanical properties, heat resistance, and electromagnetic wave shielding effect.

Examples 10-11 Powdered acrylonitrile-butadiene of Examples 7-8
Methacrylonitrile 50 instead of styrene copolymer resin
] for quantity, policy weight 10 weight and styrene 40.
Using a powdered methacrylonitrile-butadiene-styrene co-acrylic resin (MB8 resin) consisting of Kame weight 1, a composition other than that shown in the table was pelletized in the same manner as in Example 1, and this was used. An injection molded product was obtained. As a result of measuring the physical properties, it was found to be excellent in mechanical properties, heat resistance, and electromagnetic shielding effect.

A pelleted acrylonitrile-citadiene-styrene copolymer resin (ABS resin) consisting of 20% by weight of acrylonitrile, 20% by weight of polybutadiene, and 60% by weight of styrene was used, and the other formulations were as shown in the table. Composition Example 1
It was made into pellets in the same manner as above, and an injection molded product was obtained using the pellets. As a result of measuring the physical properties, it was found to be excellent in mechanical properties, heat resistance, and electromagnetic wave shielding effect.

Example 16 2- instead of tricresyl phosphate in Example 2
Take ethylhexyl diphenyl phosphate once a month, otherwise! Furthermore, the composition shown in the formulation was pelletized in the same manner as in Example 1, and an injection molded product was obtained using the pellet. As a result of measuring the physical properties, it was found to be excellent in mechanical properties, heat resistance, and electromagnetic σ shielding effect.

Comparative Examples 1 to 2 Injection molded products were made in the same manner as in Example 1, except that the plasticizer was added to the lid in an amount that was below the claimed range or exceeded the claimed range, using the compounding composition shown in the table. I got it.

The results of measuring the physical properties of this injection molded product are shown in the table.

The physical properties of the molded products shown in Examples and Comparative Examples were measured by the following method.

(Example 11', Magnetic wave shielding effect: Using the Denka method, 71% as shown in the drawing. Using a shielding effect measurement device for the magnetic wave iμ, apply the high frequency voltage excited by the tracking generator to the transmitting antenna and receive it through the sample. The ratio between the received voltage and the transmitted voltage was measured using a spectrum analyzer.

(2) Tensile strength: JIS K-6871 compliant method (3
) Bending action, bending modulus: ASTM D-790 compliant method (4) Izot (+1ii impact strength: JIS
K-6871 compliant method (with notch) (5) Heat distortion temperature: JIS K-7207 (load deflection temperature test of hard plastics) compliant method (6) UL-94 combustion test: UL-94 vertical combustion test compliant method (7) ) Oxygen index: JIS K-7201 compliant method

[Brief explanation of the drawing]

The drawing is a schematic diagram of a four-value determination device for the electromagnetic wave shielding effect of the plastic molded body of the present invention ψ. Code 1... Shield box, 2... Plastic molded product, 3... Transmitting antenna, 4... Receiving antenna, 5
...Spectrum Analyzer-16...Tracking Generator Patent Applicant Denki Kagaku Kogyo Co., Ltd. Procedural Amendment January 18, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of Case 1988 Patent Application No. No. 227019 No. 2, Name of the invention: Electromagnetic shielding resin composition having flame retardant properties, Relationship with the amended case Patent applicant address: 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Details of the invention in the specification Explanation Column 5, Contents of Amendment 1) Change “・Organic flame retardant・” to “,
"Organic flame retardant..." is corrected. 2) "Flame retardancy" on line 16 of No. 8 of the specification is corrected to "flame retardancy", and "1 weight" is added next to ".5-35" on line 17. b) Correct "mutual effect" in line 6 of page 9 of the specification to "・reciprocal effect" and correct "・ni・" in line 14 to "...ga". 4) Specification page 17, line 2, line 12, page 15, line 6
In the second and bottom line, "・Heat resistance," is followed by "Flame retardant,"
Next to "heat resistance" on page 15, item 121, "flame retardancy" is written. 5) The table on page 17 of the specification is corrected as shown in the attached sheet. Procedural amendment April 18, 1980 Director of the Japan Patent Office Mr. Kazuo Wakasugi 1 Indication of the case 1982 Patent Application No. 227019 2 Name of the invention Flame-retardant electromagnetic wave R-shielding resin composition Filter Person making the amendment Relationship to the case Patent applicant address 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Name (5
29) Denki Kagaku Kogyo Co., Ltd. - Detailed description of the invention column 5 of the specification Contents of amendment 1) Description 1, page 6, line 8 r "-20 to 75 parts by weight" followed by "preferably 20 ~6o parts by weight'' in the 10th line, r---80 to 25 parts by weight'', followed by ``preferably 8o to 4o parts by weight'', and r---25 to 9 in the 15th line.
9 parts by weight'' followed by ``preferably 65 to 65 parts by weight'',
Next to the 16th line ``r---i~75 parts by weight'', add ``preferably 65 to 65 parts by weight'' and the 16th line ``-m-
is good. " is followed by [Outside the above range, moldability and physical properties deteriorate. ” respectively. 2) Lines 18 to 20 of page 10 of the specification are corrected as follows. Furthermore, processing aids such as antioxidants, stabilizers, and lubricants may be added to improve the performance of the products of the present invention. For details, as an antioxidant, phenolic antioxidant,
Sulfur-based antioxidants and phosphorus-based antioxidants are used. The amount of antioxidant added is 0.000 parts by weight per 100 parts by weight of the resin.
01 to 4 parts by weight is preferred. As the stabilizer, metal soaps, inorganic acid salts, organic tin compounds, and composite stabilizers are used. The amount of stabilizer added is 0.01 per 100 parts by weight of resin.
~The 4-layered scene is very interesting. As lubricants, paraffin and hydrocarbon resins, fatty acids,
Fatty acid amides, fatty acid esters, aliphatic alcohols, and partial esters of fatty acids and polyhydric alcohols are used. Addition of lubricant 1 to 0.01 to 100 parts by weight of resin
A quadruple highest part is preferred. 6) Specifications, page 16, line 9, ``Add 1 part by weight of -m-zinc stearate to 1 and then 1 part by weight of J to 100 parts by weight of the resin.''

Claims (1)

[Scope of Claims]
40-70% mixture with aromatic vinyl copolymer (2) 1-10% flame retardant plasticizer made of phosphorus derivative (3) 5-4ON carbon fiber (4) Halogen-containing plasticizer An electromagnetic wave shielding resin composition having flame retardancy, characterized in that it consists of a machine flame retardant of 5 to 65 parts by weight (5) a fine combustion aid of 1 to 21 parts by weight.