Processing for producing shaped wholly aromatic polyamide resin composition article and shaped article produced thereby
First Claim
1. A process for producing a shaped wholly aromatic polyamide resin composite article, comprising the steps of:
- (a) mixing an aqueous dispersion of polytetrafluoroethylene resin particles in an amount of 0.1% to 10% by weight based on the total weight of the shaped article, the polytetrafluoroethylene resin particles having an average size of from 0.3 to 3 μ
m, with wholly aromatic polyamide polymer particles comprising at least one type of aromatic polyamide polymer having at least 85 molar % of recurring m-phenyleneisophthalamide units of the formula;
##STR2## the aromatic polyamide polymer having a melting temperature at least 50°
C. higher than the melting temperature of the polytetrafluoroethylene resin particles, and composed of a plurality of primary polyamide particles having an average size of from 0.1 to 2.0 μ
m aggregated with each other to form secondary porous polyamide particles having an average size of from 30 to 200 μ
m, to form an aqueous mixture;
(b) drying the aqueous mixture to provide a dried product comprising coated composite particles which are composed of cores consisting of the wholly aromatic polyamide polymer particles and coating layers formed on the cores consisting of the polytetrafluoroethylene resin particles;
(c) preparing a shaping feed powder of a member selected from the group consisting of the product of the drying step (b) and mixtures of the product of the drying step (b) with an additional amount of the wholly aromatic polyamide polymer particles; and
(d) subjecting the shaping feed powder to a shaping procedure in which the shaping feed powder is preheated to a temperature lower than the glass transition temperature of the aromatic polyamide polymer, under compression, and then heat-compressed at a temperature of 30°
C. to 70°
C. above the glass transition temperature and 20°
C. to 80°
C. below the melting or decomposition temperature of the aromatic polyamide polymer;
the heat-compressed feed is shaped at the temperature above the glass transition temperature and below the melting or decomposition temperature of the polyamide polymer; and
the shaped article is cooled, to provide a shaped article wherein the polytetrafluoroethylene resin particles are in the form of fibrils dispersed in a matrix consisting of the wholly aromatic polyamide polymer and connected to each other to form fine networks of the fibrils in the matrix.
0 Assignments
0 Petitions
Accused Products
Abstract
A shaped wholly aromatic polyamide resin composition article having an excellent mechanical strength, stain-proof property and antistatic property, and comprising a wholly aromatic polyamide resin matrix and a dispersoid comprising polytetrafluoroethylene resin particles in the form of fine networks of fibrils and, optionally, additional inorganic particles, dispersed in the matrix, is produced by mixing an aqueous dispersion of PTFE particles having an average size of 0.3 to 3 μm in an amount of 0.01% to 10% based on the total weight of the shaped article, with wholly aromatic polyamide particles having a melting point of at least 50° C. higher than that of PTFE and composed of porous secondary particles having an average size of 30 to 200 μm and consisting of primary particles having an average size of 0.1 to 2.0 μm; drying the mixture to provide composite particles composed of aromatic polyamide cores and PTFE coating layers on the cores; and shaping a feed powder comprising the composite particles at a temperature not lower than the glass-transition point but not lower than the melting point or heat decomposition point of the aromatic polyamide, under a pressure.
34 Citations
14 Claims
-
1. A process for producing a shaped wholly aromatic polyamide resin composite article, comprising the steps of:
-
(a) mixing an aqueous dispersion of polytetrafluoroethylene resin particles in an amount of 0.1% to 10% by weight based on the total weight of the shaped article, the polytetrafluoroethylene resin particles having an average size of from 0.3 to 3 μ
m, with wholly aromatic polyamide polymer particles comprising at least one type of aromatic polyamide polymer having at least 85 molar % of recurring m-phenyleneisophthalamide units of the formula;
##STR2## the aromatic polyamide polymer having a melting temperature at least 50°
C. higher than the melting temperature of the polytetrafluoroethylene resin particles, and composed of a plurality of primary polyamide particles having an average size of from 0.1 to 2.0 μ
m aggregated with each other to form secondary porous polyamide particles having an average size of from 30 to 200 μ
m, to form an aqueous mixture;(b) drying the aqueous mixture to provide a dried product comprising coated composite particles which are composed of cores consisting of the wholly aromatic polyamide polymer particles and coating layers formed on the cores consisting of the polytetrafluoroethylene resin particles; (c) preparing a shaping feed powder of a member selected from the group consisting of the product of the drying step (b) and mixtures of the product of the drying step (b) with an additional amount of the wholly aromatic polyamide polymer particles; and (d) subjecting the shaping feed powder to a shaping procedure in which the shaping feed powder is preheated to a temperature lower than the glass transition temperature of the aromatic polyamide polymer, under compression, and then heat-compressed at a temperature of 30°
C. to 70°
C. above the glass transition temperature and 20°
C. to 80°
C. below the melting or decomposition temperature of the aromatic polyamide polymer;
the heat-compressed feed is shaped at the temperature above the glass transition temperature and below the melting or decomposition temperature of the polyamide polymer; and
the shaped article is cooled, to provide a shaped article wherein the polytetrafluoroethylene resin particles are in the form of fibrils dispersed in a matrix consisting of the wholly aromatic polyamide polymer and connected to each other to form fine networks of the fibrils in the matrix. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
Specification