Flame resistant semiaromatic polyamide resin compositions and processes for the preparation of the compositions exhibiting increased melt flow and articles therefrom
View Patent ↗There is provided high temperature flame retarded polyamides which provide superior properties in molded articles while maintaining high flow in the molding process. The resin compositions include, in addition to the polyamide and flame retardant, talc and at least one inorganic reinforcing agent and/or filler other than talc. Processes for their preparation and articles made from these compositions are also disclosed.
1. A process for the preparation of a flame retardant polyamide resin composition, comprising melt-blending a polyamide component (a′), flame retardant (b), talc (c) and inorganic agent other than talc selected from the group consisting of reinforcing agent and filler (d) with 0.1 to 10 weight percent, based on the total weight of the polyamide (a′), of at least one aromatic organic acid having a naphthalene ring, in order to reduce an inherent viscosity of the polyamide component (a′) below 0.85 dl/g.
2. The process for the preparation of the resin composition of claim 1 , comprising melt-blending
(a′) about 30 to about 71 weight percent of a polyamide component comprising about 20 to 100 weight percent of at least one semiaromatic polyamide
(b) at least one flame retardant selected from the group consisting of a phosphinate of the formula (I); a disphosphinate of the formula (II); polymers of (I) and polymers of (II)
wherein R 1 and R 2 are identical or different and are selected from the group consisiting of linear or branched C 1 -C 6 alkyl, and aryl; R 3 is selected from the group consisting of linear or branched C 1 -C 10 -alkylene, C 6 -C 10 -arylene, C 6 -C 10 -alkylarylene and C 6 -C 10 -arylalkylene; M is selected from the group consisting of calcium ion, magnesium ion, aluminum ion and zinc ion; m is 2 to 3; n is 1 or 3; and x is 1 or 2;
(c) about 1 to about 15 weight percent of talc;
(d) about 20 to about 60 weight percent of at least one inorganic agent other than talc selected from the group consisting of reinforcing agent and filler; and
(e) about 0.1 to about 5 weight percent of at least one aromatic organic acid having anaphthalene ring,
wherein the weight percentages of (a′) and (d) are based on the total weight of the composition; wherein flame retardant (b) is present in an amount that is about 10 to about 45 percent of the weight of polyamide (a′); and wherein the weight percentages of (c) and (e) are based on the total weight of the polyamide
3. The process of claim 2 , wherein said aromatic organic acid having a naphthalene ring has a melting point that is no lower than about 10° C. less than the onset temperature of the melting point endotherm of the polyamide (a′).
4. The process of claim 1 , wherein said aromatic organic acid having a naphthalene ring is 2,6-naphthalenedicarboxylic acid.
5. The process of claim 2 , wherein said semiaromatic polyamide is selected from one or more of the group consisting of polyamide 9,T;
polyamide 10,T; polyamide 10,T/10,12; polyamide 10,T/1010; polyamide 12,T;
polyamide 6,T16,6; and polyamide 6,T/D,T.
6. The process of claim 1 wherein said reinforcing agent (d) is glass fibers.
7. The process of claim 1 wherein said reinforcing agent (d) is a combination of glass fibers and glass flakes.
8. The process of claim 1 wherein said composition further comprises zinc borate in an amount of from about 1 to about 5 percent of the weight of the flame retardant.
9. The process of claim 1 wherein said composition further comprises boehmite in an amount of from about 10 to about 20 weight percent, based on the total weight of the boehmite and flame retardant (b).
10. An article of manufacture made from compositions according to the process of claim 1 .