Patent Number: 044435657
Section: description

EXAMPLE 1 Into a four-necked glass flask having a capacity of 3 liters and equipped with a stirrer, 2.0 kg of demineralized water and 320 g of aluminum foil fragments (1.4.times.1.times.0.025 mm, K-102 manufactured by Transmet Company) were introduced and thoroughly stirred. Then, 8 g of methylmethacrylate and 8 g of dimethylaminoethylmethacrylate were added thereto and the flask was flushed with nitrogen gas and heated to 70.degree. C. After the polymerization system reached 70.degree. C., 0.8 g of potassium persulfate was added and the reaction was continued for 1.5 hours. Then, the system was heated to 90.degree. C. and the reaction was continued for 1 hour. Thereafter, while maintaining the temperature of the reaction system at 80.degree. C., 50 g of styrene, 34 g of acrylonitrile, 1 g of terpinolene as a chain transfer agent, 2 g of benzoyl peroxide as an initiator and 0.5 g of azobisisobutylonitrile were added and the polymerization were conducted for 2 hours. After completion of the reaction, the temperature was raised to 90.degree. C. and the removal of the unreacted monomers was conducted for 1 hour while supplying nitrogen gas. Thereafter, the polymer containing aluminum foil fragments was collected by filtration with use of a metal net of 200 mesh. The polymer thereby obtained had a bulk density of 0.46 g/cm.sup.3 (the bulk density of aluminum foil fragments was 0.19 g/cm.sup.3). The contents of the aluminum foil fragments was 83.3% by weight and the yield was 95%. EXAMPLE 2 A composition containing aluminum foil fragments was prepared in the same manner as in Example 1 except that 16 g of methylmethacrylate was used instead of the mixture of methylmethacrylate and dimethylaminoethylmethacrylate. The bulk density of the composition was 0.35 g/cm.sup.3, the contents of the aluminum foil fragments was 84% by weight and the yield was 96.8%. EXAMPLE 3 A composition containing aluminum foil fragments was prepared in the same manner as in Example 1 except that a mixture of 3.2 g of acrylic acid and 12.8 g of methylmethacrylate was used instead of the mixture of methylmethacrylate and dimethylaminoethylmethacrylate. The bulk density of the composition was 0.38 g/cm.sup.3, the contents of aluminum foil fragments was 90.7% by weight and the yield was 88%. COMPARATIVE EXAMPLE 1 Into a four-necked flask having a capacity of 3 liters, 2.0 kg of demineralized water and 320 g of aluminum foil fragments (which were the same as used in Example 1) were introduced and throughly stirred to obtain a dispersion. Then, 62.5 g of styrene, 37.5 of acrylonitrile, 1 g of terpinolene, 2 g of benzoylperoxide and 0.5 g of azobisisobutylonitrile were added thereto and the polymerization was conducted at 80.degree. C. for 2 hours. The temperature was then raised to 90.degree. C. and the removal of the unreacted monomers was conducted for 1 hour while supplying nitrogen gas. The bulk density of the polymer was 0.28 g/cm.sup.3 and the yield was 83% However, a great number of polymer particles containing no aluminum foil fragments were present. Further, there remained some aluminum fragments which were not coated with the polymer and which were not laminated. EXAMPLE 4 Into the same flask as used in Example 1, 2.0 kg of demineralized water and 900 g of copper foil fragments (1.5.times.1.3.times.0.035 mm) were introduced and stirred to obtain a dispersion. Then, 10 g of methylmethacrylate and 10 g of dimethylaminomethacrylate were added thereto and the temperature was raised to 70.degree. C. After the temperature reached 70.degree. C., 2 g of potassium persulfate was added and the above monomer mixture was polymerized for 1.5 hours and then the polymerization was conducted at 90.degree. C. for 1 hour. After the polymerization system was cooled to 80.degree. C., 64 g of styrene, 36 g of acrylonitrile, 1 g of terpinolene, 3 g of benzoylperoxide and 2 g of azobisisobutylonitrile were added and the polymerization was conducted for 2 hours. The composition containing the copper foil fragments was collected by filtration with a metal net of 200 mesh. The bulk density of the composition thereby obtained was 1.44 g/cm.sup.3 (the bulk density of the copper foil fragments per se was 0.95 g/cm.sup.3). The content of the copper foil fragments was 91.5% by weight and the yield was 97%. APPLICATION EXAMPLE 1 The composition obtained by Example 1 was dry-blended with an ABS resin (TFX-455 AB manufactured by Mitsubishi Monsanto Chemical Company) to bring the aluminum foil content to be 40% by weight and the blended mixture was injection-molded. The composition thereby obtained had the following physical properties. Tensile strength (Breaking point) 365 kg/cm.sup.2 (measured in accordance with JIS K-6871) PA0 Elongation for breakage 1.7% (measured in accordance with JIS K-6871) PA0 Izod impact strength 6.1 kg.cm/cm (measured in accordance with JIS K-6871) PA0 Specific volume resistance* 3.0 .OMEGA..multidot.cm FNT *measured with a test piece of 1.27.times.1.27.times.10 cm. APPLICATION EXAMPLE 2 The composition obtained by Example 4 was mixed with an ABS resin (TFX-455 AB manufactured by Mitsubishi Monsanto Chemical Company) to bring the copper foil contents to be 70% by weight and the mixture was pelletized by a single shaft extruder. The pellets thereby obtained were molded to obtain test pieces. The specific volume resistance of the test pieces as measured in the same manner as in Application Example 1 was 10.sup.2 .OMEGA..multidot.cm or less. EXAMPLE 5 Into a four-necked glass flask having a capacity of 3 liters and equipped with a stirrer, 2.0 kg of demineralized water, 280 g of aluminum foil fragments (1.4.times.1.times.0.025 mm, K-102 manufactured by Transmet Company) and 40 g of zinc foil fragments (2.0.times.1.times.0.020 mm, manufactured by Fukuda Metal Foil Company) were introduced and thoroughly stirred. Then, 8 g of methylmethacrylate and 8 g of dimethylaminoethylmethacrylate were added thereto. The flask was flushed with nitrogen gas and the temperature was raised to 70.degree. C. After the polymerization system reached 70.degree. C., 0.8 g of potassium persulfate was added and reaction was conducted for 1.5 hours. Then, the temperature was raised to 90.degree. C. and reaction was conducted for 1 hour. Then, while maintaining the temperature of the polymerization system at 70.degree. C., 50 g of styrene, 34 g of acrylonitrile, 1 g of terpinolene as a chain transfer agent, 2 g of benzoyl peroxide as an initiator and 0.5 g of azobisisobutylonitrile were added and the polymerization was conducted for 2 hours. After completion of the reaction, the temperature was raised to 90.degree. C. and the removal of the unreacted monomers was conducted for 1 hour while supplying nitrogen gas. Thereafter, the polymer containing laminated metal foil fragments was collected by filtration with use of a metal net of 200 mesh. The bulk density of the polymer thereby obtained was 0.45 g/cm.sup.3 and the content of the metal foil fragments was 82.6%. EXAMPLE 6 A composition containing metal foil fragments was prepared in the same manner as in Example 5 except that the metal foil fragments were replaced by 300 g of aluminum foil fragments and 20 g of zinc foil fragments. The content of the metal foil fragments was 83.5%. EXAMPLE 7 A composition containing metal foil fragments was prepared in the same manner as in Example 5 except that the metal foil fragments were replaced by 160 g of aluminum foil fragments and 160 g of zinc foil fragments. The content of the metal foil fragments was 82.0%. EXAMPLE 8 A composition containing metal foil fragments was prepared in the same manner as in Example 5 except that the metal foil fragments were replaced by 280 g of aluminum foil fragments and 40 g of copper foil fragments. The content of the metal foil fragments was 81.6%. EXAMPLE 9 A composition containing metal foil fragments was prepared in the same manner as in Example 5 except that no aluminum foil fragments were added and 720 g of zinc foil fragments were used. The content of the zinc foil fragments was 91.0%. EXAMPLE 10 A composition containing metal foil fragments was prepared in the same manner as in Example 5 except that 320 g of copper foil fragments were used as the metal foil fragments. The content of the copper foil fragments was 83.0%. APPLICATION EXAMPLES 3 TO 9 The compositions obtained by Examples 1 and 5 to 10 were respectively dry-blended with an ABS resin (TFX-455 AB manufactured by Mitsubishi Monsanto Chemical Company) to bring their metal foil content to be 45% by weight and the blended mixtures were respectively pelletized and injection-molded. The physical properties of the respective molded products are shown in Tables 1 and 2. APPLICATION EXAMPLE 10 The compositions obtained by Examples 1 and 9 were mixed in such a proportion that aluminum foil fragments were 87.5% by weight and the zinc foil fragments were 12.5% by weight, and the mixture was dry-blended and the physical properties of the product was measured in the same manner as in Application Example 3. The results thereby obtained are shown in Table 1. APPLICATION EXAMPLE 11 87.5% by weight of the aluminum foil fragments and 12.5% by weight of the zinc foil fragments as used in Example 5 were mixed and the mixture was blended with an ABS resin as used in Application Example 3 by a double shaft extruder to bring the metal foil content to be 45% by weight. The results thereby obtained are shown in Tables 1 and 2. TABLE 1 __________________________________________________________________________ Metal Ratio of different metal foil foil fragments Specific Application contents Al Zn Cu resistane Examples Compositions (wt. %) wt. % wt. % wt. % (.OMEGA. .multidot. cm) __________________________________________________________________________ 3 Example 1 45 100 0 0 1.5 4 Example 6 45 93.7 6.3 0 0.090 5 Example 5 45 87.5 12.5 0 0.048 6 Example 7 45 50 50 0 0.35 7 Example 8 45 87.5 0 12.5 0.37 8 Example 9 45 0 100 0 13.3 9 Example 10 45 0 0 100 10 or greater 10 Example 1 + 45 87.5 12.5 0 1.7 Example 9 11 Aluminum foil 45 87.5 12.5 0 1.8 + zinc foil __________________________________________________________________________ The specific resistance was obtained by measuring the resistance of a test piece of 1.27.times.1.27.times.10 cm between two points thereof at a distance of 10 cm. TABLE 2 ______________________________________ Application Attenuation of electromagnetic waves (dB) Examples Frequency 10 MHz 100 MHz 1 GHz ______________________________________ 3 24 22 23 4 54 56 64 5 64 72 78 7 43 39 29 9 23 23 33 ______________________________________ The attenuation of electromagnetic waves was measured by placing a disk-shaped test piece having an outer diameter of 90 mm and a thickness of 3.2 mm and provided at its center with a coaxial disk-shaped through-hole having a diameter of 25 mm, in a coaxial transmission tube and measuring the difference between the input and the output.