发明名称 |
Polyamide films for flexible printed circuit boards |
摘要 |
The invention relates to a polymer film made of a polyamide composition comprising at least 80 weight percentage (wt. %) of a semi-crystalline semi-aromatic polyamide with a melting temperature (Tm) of at least 270° C., wherein the wt. % is relative to the total weight of the polymer composition, wherein the polymer film has an average coefficient of thermal expansion in plane in the temperature range of 20° C.-Tg, measured in plane with the method according to ASTM D969-08, of at most 40 ppm/K. The said film can be made from a polyamide moulding composition comprising said polyamide by film casting followed by biaxial stretching. The film has properties suitable for carrier films in flexible printed circuit boards. |
申请公布号 |
US8778247(B2) |
申请公布日期 |
2014.07.15 |
申请号 |
US201013144759 |
申请日期 |
2010.01.15 |
申请人 |
DSM IP Assets B.V. |
发明人 |
Stroeks Alexander Antonius Marie;Struijk Guido Richard |
分类号 |
B29C47/88;B29C71/00;B29C55/12 |
主分类号 |
B29C47/88 |
代理机构 |
Nixon & Vanderhye P.C. |
代理人 |
Nixon & Vanderhye P.C. |
主权项 |
1. A process for the production of a dimensionally stable polymer film, comprising steps of:
(i) melt-processing a polymer moulding composition at a temperature above a melting temperature (Tm) to form a polymer melt thereof, wherein the moulding composition comprises at least 80 wt. % relative to the total weight of the polymer composition of a semi-crystalline semi-aromatic polyamide having a melting temperature (Tm) of at least 290° C. as measured according to ASTM D3418-03 by DSC with a heating rate of 10° C. and a glass transition temperature (Tg) measured according to ASTM E 1356-91 by DSC with a heating rate of 10° C., wherein the semi-crystalline semi-aromatic polyamide comprises repeat units derived from dicarboxylic acids and diamines, the dicarboxylic acids consisting of 70-100 mole % terephthalic acid, and other repeat units in a total amount in the range of 0-5 mole %, relative to the total molar amount of repeat units derived from dicarboxylic acids and diamines; (ii) extruding the polymer melt obtained in step (i) into a film and thereafter immediately casting and cooling the film to a temperature below the glass transition temperature (Tg) to form a cast film; (iii) biaxially stretching the cast film obtained in step (ii) at a temperature in a range of Tg-5° C up to and including Tg+10° C.; and (iv) heat-setting the biaxially stretched film obtained in step (iii) at a temperature between the glass transition temperature and the melting temperature to obtain a dimensionally stable polymer film having an average thermal expansion coefficient (TEC) in a temperature range of 20° C.-Tg, measured in a plane according to ASTM D696-08, of at most 40 ppm/K. |
地址 |
Heerlen NL |