Flame retardant polyamide
A composition contains at least a copolyamide (PA-1) as a component (I), produced by polymerization of at least one lactam and of a monomer mixture (M) which contains at least a C 32 -C 40 dimer acid and at least a C 4 -C 12 diamine; and a flame retardant (F1) as a component (II). The flame retardant (F1) is selected from melamine cyanurates, magnesium hydroxide, and phosphorus-containing flame retardants. A process can be used for preparing such compositions, and the composition can be used for producing shaped articles.
1 . A composition, comprising:
(I) 20% to 80% by weight of a copolyamide (PA-1) and (II) 20% to 40% by weight of a flame retardant, based on overall composition weight;
wherein the copolyamide (PA-1) is prepared by polymerization of: (A) 15% to 84% by weight of at least one lactam, and (B) 16% to 85% by weight of a monomer mixture (M), based on a sum total of percentages by weight of the components (A) and (B);
wherein the monomer mixture (M) comprises: (B1) 45 to 55 mol % of at least one C32-C40 dimer acid, and (B2) 45 to 55 mol % of at least one C4-C12 diamine;
wherein the flame retardant is selected from the group consisting of a melamine cyanurate, magnesium hydroxide, a phosphorus-containing flame retardant, and a mixture of the melamine cyanurate and the phosphorus-containing flame retardant;
wherein the phosphorus-containing flame retardant is selected from the group consisting of a derivative of phosphoric acid, a derivative of phosphonic acid, a derivative of phosphinic acid, and mixtures of two or more of these derivatives; and
wherein the composition has a broad processing range of from 180° C. to 240° C.
2 . The composition according to claim 1 , wherein
the phosphorus-containing flame retardant is a mixture of a first flame retardant (F1) selected from the group consisting of a derivative of phosphoric acid, a derivative of phosphonic acid, and mixtures thereof, and a second flame retardant (F2) selected from the group consisting of a derivative of phosphinic acid.
3 . The composition according to claim 2 , wherein
the first flame retardant (F1) is selected from the group consisting of resorcinol bis(diphenyl phosphate) (RDP), bisphenol A bis(diphenyl phosphate) (BDP), diphenyl cresyl phosphate (DPK), and mixtures thereof.
4 . The composition according to claim 1 , wherein the copolyamide (PA-1) has a glass transition temperature (TGc) in the range of from 20 to 50° C.
5 . The composition according to claim 1 , comprising 20% by wt. of the flame retardant (II).
6 . The composition according to claim 1 , comprising 30% by wt. of the flame retardant (II).
7 . The composition according to claim 1 , wherein component (B1) is at least one C36 dimer acid.
8 . The composition according to claim 1 , wherein component (B2) is selected from the group consisting of tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine and dodecamethylenediamine.
9 . The composition according to claim 1 , wherein the copolyamide (PA-1) is a random copolymer.
10 . The composition according to claim 1 , wherein the copolyamide (PA-1) has a glass transition temperature (TGc) in the range of from 25 to 45° C.
11 . The composition according to claim 1 , further comprising: at least one filler selected from the group consisting of glass fibers, carbon fibers, aramid fibers, potassium titanate fibers, fibers of liquid-crystalline polymers, metal fibers, polyester fibers, polyamide fibers, organic fibrous fillers and inorganic fibrous fillers.
12 . A process for producing the composition of claim 1 , the process comprising:
(a) providing components (I) and (II) such that component (I) is present in amount of 20% to 80% by weight and component (II) is present in an amount of 20% to 40% by weight, based on overall composition weight; and
(b) mixing components (I) and (II) within the processing range of from 180° C. to 240° C.
13 . The process according to claim 12 , further comprising:
optionally drying the components prior to step (b), at a temperature of from 80° C. to 100° C., and a period of from 2 to 4 hours.
14 . The process according to claim 12 , wherein the mixing in (b) is performed at a temperature of from 200° C. to 225° C.
15 . A method, comprising: producing a shaped article with the composition according to claim 1 .
16 . A shaped article, prepared by the method of claim 15 .
17 . The shaped article according to claim 16 , wherein the article is transparent.