A series of functionalized mesoporous silicas with cagelike pore topology has been synthesized and screened for size-selective catalytic transformations. The aluminum-catalyzed Meerwein-Ponndorf-Verley (MPV) reduction of differently sized aromatic aldehydes (benzaldehyde and 1-pyrenecarbox-aldehyde) has been investigated as a test reaction. The catalysts were synthesized in a two-step grafting sequence
Ionomers comprising higher alkyl ammonium or quaternary polyammonium salts of polyacids, particularly sulfonic acids, having anionic groups covalently bonded to carbon atoms comprising a backbone chain of a polymer, or to acyclic, alicyclic or aromatic radicals which are pendant to the backbone chain of the polymer, are novel compositions of matter. These ionomers vary in properties from water-soluble polyelectrolytes useful as thickening agents to thermoplastic elastomers which can be extruded, injection molded, vacuum formed, etc. at elevated temperatures. The elastomers are useful as speciality and general purpose rubbers.
Polyamide resin composition having improved weathering resistance and its molded products
申请人:MITSUBISHI ENGINEERING-PLASTICS CORPORATION
公开号:EP1074585A1
公开(公告)日:2001-02-07
The present invention relates to a polyamide resin composition comprising:
100 parts by weight of a polyamide resin mixture comprising
(A) 20 to 90% by weight of a polyamide 6 resin and/or polyamide 66 resin and
(B) 10 to 80% by weight of an aromatic polyamide resin;
and
(C) 0 to 300 parts by weight of an inorganic filler, the said aromatic polyamide resin having diamine units comprising 10 to 50 mol% of paraxylylenediamine units and 50 to 90 mol% of methaxylylenediamine units, and aliphatic dicarboxylic acid units, proviso that when the amount of the said inorganic filler is not less than 45 parts by weight, the said polyamide resin composition further comprises at least one component selected from the group consisting of
(D) 0.05 to 5 parts by weight of a light stabilizer,
(E) 0.05 to 5 parts by weight of a phenolic antioxidant and
(F) 0.01 to 5 parts by weight of a copper compound and/or a halide,
based on 100 parts by weight of the polyamide resins (A) and (B).
[Problems]
Provided is a polyamide resin material having high elastic modulus, good gas barrier properties, low water absorption and excellent flexibility.
[Means for solving the problems]
This is a polyamide resin composition comprising a polyamide resin (A) composed of a diamine structural unit and a dicarboxylic acid structural unit wherein 70 mol % or more of the diamine structural unit is derived from xylylenediamine and 50 mol % or more of the dicarboxylic acid structural unit is derived from sebacic acid, and 1 to 40 parts by mass of at least one copolyamide (B) selected from the following group consisting of (B-1)-(B-3) per 100 parts by mass of the polyamide resin (A);
(B-1): a copolyamide 6/66/12;
(B-2): a copolyamide 6/66/11;
(B-3): a polyether-polyamide copolymer composed of a polyamide 12 unit or a polyamide 11 unit and a polyether unit.
Provided is a thin-wall article formed from a polyamide resin which can be stably produced with little variation in mechanical properties such as flexural strength, flexural modulus and impact resistance. Athin-wall article formed by molding a polyamide resin (C) obtained by polycondensing a diamine (A) and a dicarboxylic acid (B) or a polyamide resin composition containing the polyamide resin, wherein 70 mol % or more of a diamine structural unit is derived from xylylenediamine and the polyamide resin has a melt viscosity (i) of 50 to 200 Pa·s as measured at a temperature of the melting point plus 10°C for a holding time of 6 minutes at a shear rate of 122 sec-1.