JPS58147446A - Thermoplastic resin composition containing metallic foil pieces and its preparation - Google Patents

Abstract

PURPOSE:To obtain a resin composition containing uniformly dispersed metallic foil pieces in high concentration, and having sufficiently high strength, by mixing an aromatic vinyl polymer with metallic foil pieces coated with a specific amount of a (co)polymer of (meth)acrylic acid, etc. CONSTITUTION:100pts.wt. of metallic foil pieces (0.5-5 square pieces of 5- 50mum thick made of Al, Cu or their alloy) are coated with 1-10pts.wt. of a (co)polymer derived and (meth)acrylic acid, alkyl (meth)acrylatel and aminoalkyl (meth)acrylate, and the coated foil pieces are mixed with 5-13pts.wt. of a (co) polymer of an aromatic vinyl compound. The composition can be prepared by carrying out the suspension polymerization of the first monomer in the presence of the metallic foil pieces, adding the aromatic vinyl compound thereto, and carrying out the second suspension polymerization. The obtained composition can be used as it is or in combination with an ABS resin, an AS resin, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition containing a high concentration of metal foil pieces and a method for producing the same.

Recently, devices with built-in sources of electromagnetic waves, such as microwave ovens, TVs, and microcomputers, have become widespread.
There is electromagnetic interference to measuring instruments, etc.

When assembling these devices, metal shells are often used to avoid interference from magnetic waves.
Since many steps are required for molding, painting, etc., there has been a desire to develop a thermoplastic resin material that is easy to mold and that has a large amount of attenuation of electromagnetic waves passing through it.

However, if a thermoplastic resin is mixed with a large amount of metal foil (A4 Cu, etc.) that is effective at attenuating electromagnetic waves, it will be difficult to get into the screw in a single-screw extrusion mode, and it is difficult to get it into the screw by mechanical kneading alone. It was difficult for the metal foil pieces to be sufficiently dispersed in the resin, and the strength of the resulting resin composition was also unsatisfactory.

The present inventors solved the problems of the prior art described above, and obtained a resin composition that contains metal foil pieces at a high concentration, has good dispersion of the metal foil pieces, and has sufficient strength. The present invention was arrived at as a result of intensive research with the first objective being to develop a method for producing such a resin composition.

The first object of the present invention is that the surface of 100 parts by weight of a metal foil piece is made of a monomer selected from the group consisting of acrylic acid, methacrylic acid, alkyl acrylate, aminoalkyl acrylate, alkyl methacrylate, and aminoalkyl methacrylate; Alternatively, the surface is coated with 7 to /θ parts by weight of a first polymer obtained by polymerizing a mixture of two or more monomers, and aromatic vinyl is added to 100 parts by weight of a metal foil piece. This can be achieved by a composition obtained by blending 33 parts by weight of the first monomer j obtained by polymerizing a mixture consisting of a monomer and a monomer copolymerizable with an aromatic vinyl monomer.

A second object of the present invention is to provide a method for producing a composition containing 6 to 3 parts by weight of a thermoplastic resin based on 100 parts by weight of a piece of metal foil. , 7 to 10 parts by weight of a monomer selected from the group consisting of alkyl methacrylate and aminoalkyl methacrylate or a mixture of two or more monomers are subjected to suspension polymerization in the coexistence of 700 parts by weight of metal foil pieces. , followed by a mixture consisting of an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer! This cannot be achieved by adding ~33 parts by weight and carrying out suspension polymerization.

The metal foil piece used in the present invention is Az.

Those made of alloys of metals such as Cu, etc. are preferable from the viewpoint of conductivity, but those made of other metals are preferable, and rectangular ones with a diameter of 7 to 2 mm are more preferable. Other shapes may be used as long as they are of equivalent size.

These metal foil pieces have a surface coated with a polymer of a monomer or a mixture of monomers selected from the group consisting of acrylic acid, methacrylic acid, alkyl acrylate, aminoalkyl acrylate, alkyl methacrylate, and aminoalkyl methacrylate. is coated. A single combination of these is suitable because it has high adhesiveness to the metal foil piece.

In this case, per 100 parts by weight of the metal foil piece, 1 of the above-mentioned combinations/
~70 parts by weight is appropriate.0 If it is less than 7 parts by weight, there is no coating effect, and if it exceeds 70 parts by weight, the amount of polymer that does not adhere to the surface of the metal foil piece increases, which may adversely affect the physical properties of the composition. I don't like the nature.

The polymer used to coat the metal foil piece may be one obtained by polymerizing the above-mentioned monomers alone, or may be one obtained by polymerizing a mixture of two or more arbitrary monomers. For example, methyl methacrylate alone or a mixture of methyl methacrylate and acrylic acid containing 70 to 30 wt% of acrylic acid are used.
A polymer obtained by polymerizing a mixture of methyl methacrylate and aminoalkyl methacrylate containing % wt% is excellent in terms of coverage of metal foil pieces and compatibility with other resins. In this case, the aminoalkyl group is preferably dimethylaminoethyl group ((CH3)2NCH2CH2-),
Diethylaminoethyl group, dimethylaminepropyl group, etc. are also used.

Further, the alkyl group preferably has 1 to 10 carbon atoms in terms of physical properties such as tensile strength. The blending ratio of each monomer mixture is not limited to the above range, but if it is within the above range, good results can be obtained in terms of coverage, dispersibility, physical properties, etc. of the surface of the metal foil piece. .

To coat a metal foil piece with the above polymer, the metal foil piece may be immersed in a solution in which the polymer is dissolved in a suitable organic solvent; Coating can be more easily achieved by suspension polymerization in the presence of.

Subsequently, a mixture consisting of an aromatic vinyl monomer and a monomer copolymerizable with the monomer is polymerized to iooM parts of the metal foil pieces used initially to obtain a polymer j to 33% by weight. parts, and the total amount of the polymer used to coat the surface of the metal foil piece is 6 to 6 parts by weight based on 100 parts by weight of the metal foil piece initially used.
Blend so that it becomes 4t3 parts by weight.

If the amount of the aromatic vinyl monomer and the monomer copolymerizable with it is less than 1 part by weight, the bulk density of the resulting composition will be low, and when compounding with ABS, the metal foil piece will be This is not preferred because it becomes difficult to increase the concentration.

Examples of the aromatic vinyl monomer used in the present invention include styrene, α-methylstyrene, vinyltoluene, and nuclear halogenated styrene. Further, as the "copolymerizable monomer", acrylonitrile, methacrylonitrile, and alkyl esters of acrylic acid and methacrylic acid are suitable. The appropriate concentration of these "copolymerizable monomers" in the monomer mixture is 10 to t0wt%. If it is outside the above range, the compatibility with other resins will deteriorate, which is not preferable.

In order to produce the composition according to the present invention, it is preferable to carry out suspension polymerization of each of the above monomers in the presence of gold FjA foil pieces.

That is, 100 parts by weight of a metal foil piece, and a monomer selected from the group consisting of acrylic acid, methacrylic acid, alkyl acrylate, aminoalkyl acrylate, alkyl acrylate, and aminoalkyl methacrylate,
Alternatively, 7 to 70 parts by weight of the monomer mixture is suspended in water and subjected to suspension polymerization by a conventional method. In this case, the use of a water-soluble initiator (persulfate, etc.) provides better coverage of the foil surface. After the polymerization is completed, 1 to 33 parts by weight of a mixture of an aromatic vinyl monomer and a monomer copolymerizable therewith are added to further carry out suspension polymerization.

The obtained composition had a pellet shape made by laminating several dozen metal foils, and had a large bulk density (it also had good compatibility with ABS resin and the like).

The composition according to the present invention can be used as is, but
It can also be used in combination with ABS resin, AS resin, etc. In this case, compounding can be carried out using a single screw extruder. The resulting composition has good physical properties and exhibits good electrical conductivity.

Furthermore, the metal foil pieces may peel off due to an external force. There is hardly any.

The present invention will be explained in more detail based on Examples, Comparative Examples, and Application Examples.

Example 1 Deionized water - 8 kg and aluminum (At) foil pieces (
/Jmmx /mmxθ, θ2j fight, Transmet
Add K-10, :z) 3aθV and stir well. In this, methyl methacrylate I? 2 and dimethylaminoethyl methacrylate? 2 was added, and the inside of the flask was replaced with nitrogen gas, and then the temperature was raised to 20°C. After the polymerization system reached 7θ°C, 0.0% potassium persulfate was added. 2 was added and reacted for 3 hours. Subsequently, the temperature was raised to 0℃ and 7
Allowed time to react. Set the temperature of the polymerization system to 0℃,
styrene! Polymerization was carried out for 2 hours by adding 02, acrylonitrile 3, 7, Terpi 4ii'''/2 as a chain transfer agent, benzoyl peroxide λ?, azobisimptilonitrile θ, !2 as an initiator. After the reaction was completed. The temperature was then raised to 0° C., and unreacted monomers were removed for 7 hours under nitrogen gas flow.

Thereafter, the polymer containing the At foil pieces was distributed door to door using a λθO mesh wire gauze.

The bulk density of the obtained polymer was 0. t, t ty /c
l (The bulk density of the A4 foil piece used is o, /9y/7 people A
The content of the foil piece is J' j, j wt%, the yield is 5%
◎ Example - A/, a foil piece-containing composition was produced in the same manner as in Example/, except that methyl methacrylate 76F was used instead of the mixture of methyl methacrylate and dimethylaminoethyl methacrylate.

Bulk density is 0. ．． 3 j f /7, At content is w
t%, yield scale6. and %.

Example 3 Instead of the mixture of methyl methacrylate and dimethylaminoethyl methacrylate, acrylic f93.2 f
, 1 and methyl methacrylate/2Jf was used in the same manner as in Examples/Examples, except that a composition containing At foil pieces was produced.

The bulk density is o, 3z y /crl, and the At content is 0.
The yield was 2 wt%.

Comparative Example Deionized water was placed in a four-loaf flask with an internal volume of 3 tons - 0 Ωk.
g, At foil piece (same as that used in Example 1) 32
09 was added and stirred well to disperse. To this, styrene t 2.3 F, acrylonitrile 37jf, terpy f/2, benzoyl peroxide-22 and azobisin butyronitrile 0. Add jV and L! Polymerization was carried out at 0° C. for 2 hours.

Subsequently, the temperature was raised to 0° C., and unreacted monomers were removed for an hour while flowing nitrogen gas.

The bulk density of the polymer is o, 2. ry/crd, also
The yield was 23%, but a large number of aluminum foil pieces were prepared by using the same apparatus as in the example/deionized water λ, θ, 9, copper foil cut pieces (i, sw x i, 3tnm xθ, θ3sr).
rm)”ri009 was added and stirred to disperse.To this,
Ioy was added to each of methyl methacrylate and dimethylaminoethyl methacrylate, and the temperature was raised to 20°C.

After raising the temperature, potassium persulfate was added and the above monomer mixture was polymerized for 1 hour, and further polymerized for 7 hours at 0°C. What is the temperature of the polymerization system? After cooling down to θ℃, styrene 6
2, acrylonitrile 362, turbino/f, benzoyl peroxide 32 and azobisisobutyronitrile 2
2 was added and polymerized for one hour.

The composition containing the copper foil pieces was distributed door to door with a 200 mesh wire mesh.

The bulk density of the obtained composition is /, ri￥f/(yd, the bulk density of only the copper foil pieces used is Oo rij f /crl), and the content of the copper foil pieces is 8! wt% And the yield! P7%.

Application Example/Example/The composition obtained in Example/was injection molded after being coated with an At foil piece. The physical properties of the obtained composition were as follows.

Tensile strength at break 3Q/,,i (JIS,
K bow 2/(τ from C]; ] constant) Breaking elongation 7.2%
-() engineeringzOd impact strength t, 1kg-cm/cm ('
) Volume resistivity* 3. θΩ-m * /, 27cm X /, 27cm X / Ocm
One measurement was carried out using a test piece.

Application Example λ The composition obtained in Example G and ABSII] fat (Mitsubishi Monsanto Chemical Co., Ltd. TFX-ty: jit AB) were mixed so that the copper content was 2θwt%, and the mixture was pelletized using a single screw extruder. The volume resistivity of the test piece molded using pellets was measured in the same manner as in Application Example/1.
It was 0-2Ω- below the subplate.

Patent applicant Mitsubishi Monsanto Chemical Co., Ltd. Representative
Person Patent Attorney Hase - (7 others)

Claims (2)

[Claims] (1) The surface of the metal foil piece ioo weight part is acrylic acid,
The first monomer obtained by polymerizing one type of monomer selected from the group consisting of methacrylic acid, alkyl acrylate, aminoalkyl acrylate, alkyl methacrylate, and aminoalkyl methacrylate, or a mixture consisting of two or more types of monomers. The surface is coated with 7 to 70 parts by weight of a polymer, and an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer per 100 parts by weight of the metal foil piece. A composition comprising 33 parts of the first polymer S obtained by polymerizing the mixture. (2) One type of monomer selected from the group consisting of acrylic acid, methacrylic acid, alkyl acrylate, aminoalkyl acrylate, alkyl methacrylate, and aminoalkyl methacrylate, or a mixture of two or more types of monomers 7 to 10 part by weight in the coexistence of 700 parts by weight of metal foil pieces, and then a mixture consisting of an aromatic vinyl monomer and a monomer that can be combined with an aromatic vinyl monomer, f ~ 33 parts by weight. A method characterized in that suspension polymerization is carried out by adding 50% of