E/E connector and polymer composition used therein
This invention relates to a flame retardant polyamide composition comprising a semi-aromatic polyamide, a flame retardant system and a reinforcing agent, wherein the semi-aromatic polyamide comprises units derived from dicarboxylic acids comprising terephthalic acid and aliphatic dicarboxylic acids, and aliphatic diamines. In the semi-aromatic polyamide the aliphatic diamines consist of 10-70 mole % of a short chain aliphatic diamine with 2-5 C atoms and 30-90 mole % of a long chain aliphatic diamine with at least 6 C atoms; the dicarboxylic acids consist of 5-65 mole % aliphatic dicarboxylic acid and optionally aromatic dicarboxylic acid other than terephthalic acid and 35-95 mole % terephthalic acid; and the combined molar amount of terephthalic acid and the long chain aliphatic diamine is at least 60 mole %, relative to the total molar amount of the dicarboxylic acids and diamines. The invention also relates to a housing for an electrical/electronic (E/E) connector and use therein of the flame retardant polyamide composition, to a surface mounting process wherein the E/E connector is used and to a surface mounted device comprising the E/E connector.
1. An electrical connector for joining electrical circuits together in electrical or electronic applications, comprising a conductive element and a plastic housing, wherein at least part of the conductive element is embedded in the housing, and wherein the plastic housing comprises a flame retardant polyamide composition which exhibits blister resistance when heated during a reflow soldering of the conductive element to a peak temperature in the range of 260° C. to 300° C., wherein the flame retardant polyamide composition consists of:
25-80 wt. % of a semi-aromatic polyamide having a glass transition temperature (Tq) of at least 110° C. and at most 140° C. and a melt temperature (Tm) of at least 300° C. and at most 340° C.;
5-50 wt. % of a reinforcing agent;
1-40 wt. % of a flame retardant system comprising at least one flame retardant; and
0-25 wt. % polymers other than the semi-aromatic polyamide,
0-25 wt. % inorganic fillers, and/or
0-5 wt. % auxiliary additives, wherein
the weight percentages (wt. %) are relative to the total weight of the composition and wherein the semi-aromatic polyamide comprises units derived from aliphatic diamines and dicarboxylic acids, and wherein
a) the dicarboxylic acids (A) consist of a mixture of (A1) 5-65 mole % aliphatic dicarboxylic acid, less than 25 mole % aromatic dicarboxylic acids other than terephthalic acid, and (A2) 35-95 mole % terephthalic acid;
b) the aliphatic diamines (B) consist a mixture of (B1) 10-70 mole % of a short chain aliphatic diamine with 2-5 C atoms, and (B2) 30-90 mole % of a long chain aliphatic diamine with at least 6 C atoms; and
c) the combined molar amount of the terephthalic acid (A2) and the long chain aliphatic diamine (B2) is at least 60 mole %, relative to the total molar amount of the dicarboxylic acids and diamines.
2. The electrical connector according to claim 1 , having a comparative tracking index (CTI) of at least 500 V.
3. The electrical connector according to claim 1 , wherein the electrical connector is an I/O connector, a card (PCB) connector, an FPC (flexible printed circuit) connector, an FFC (flexible foil circuit) connector, a high speed connector, a terminal block, an MID (moulded integrated device) connector, or a plug and socket connector, or any combination thereof.
4. The electrical connector according to claim 1 , wherein the aliphatic diamines (B) consist a mixture of (B1) a short chain aliphatic diamine with 4 or 5 C atoms, and (B2) a long chain aliphatic diamine having 6 C atoms.
5. An electrical or electronic device comprising the electrical connector according to claim 1 , mounted by an SMT process comprising a thermal soldering step.