Reinforced thermoplastics sheet and its manufacturing process
AssigneeExxon Chemical Patents Inc.
InventorMichel Goguelin
Life of this patent
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Abstract
Fiber reinforced thermoplastics sheet is produced by a wet method from (a) an aqueous dispersion of reinforcing fibers an dispersing agent; and (b) an aqueous dispersion of thermoplastics polymer powder and an ionic polymer additive of opposite charge to the fiber dispersion. The dispersions are mixed, a high molecular weight ionic polymer flocculating agent is added, of charge opposite to that of the mixture, and the resulting suspension is drained and dried to form the sheet.
Claims26
A process for preparing by the wet method a reinforced thermoplastics semi-finished product in sheet form, which process comprises the following steps:
- (a) mixing
- (i) a first aqueous dispersion of an ionic dispersing agent having an ionic charge with reinforcing fibers, and
- (ii) a second aqueous dispersion containing at least one thermoplastics polymer powder and at least one ionic polymer additive of opposite charge to that of the ionic dispersing agent of the first dispersion, to form a mixture,
- (b) incorporating into the mixture a flocculating agent in ionic polymer form, of high molecular weight and of charge opposite to that of said mixture, and
- (c) draining the resulting suspension and drying the resulting semi-finished product.
A semi-finished reinforced thermoplastics product in sheet form, comprising from 96 to 99.5% by weight of well dispersed and uniformly distributed thermoplastics component, reinforcing fibers and optionally reinforcing filler(s), the balance including the residues of dispersing agents, ionic polymer additives and flocculating agents derived from the process by which said product is formed.
A process for preparing by the wet method a reinforced thermoplastics semi-finished product in sheet form, which process comprises the following steps:
- (a) mixing
- (i) a first aqueous dispersion of from 5 to 15 wt % based on the fibers of a cationic, fatty acid-containing dispersing agent with reinforcing glass fibers of length from 6 to 25 mm and unit diameter from 10 to 20 microns, and
- (ii) a second aqueous dispersion containing at least one thermoplastics polymer powder of average granulometry less than 800 microns and from 0.1 to 0.5 wt % based on the dry powder weight of at least one ionic polycarboxylic polymer additive of opposite charge to that of the first dispersion, to form a mixture,
- (b) incorporating into the mixture from 0.5 to 1.5 wt % based on the dry weight of the aqueous suspension of a cationic polyacrylamide flocculating agent, of high molecular weight and of charge opposite to that of said mixture, and
- (c) draining the resulting suspension and drying the resulting semi-finished product.
A process for preparing by the wet method a reinforced thermoplastics semi-finished product in sheet form, which process comprises the following steps:
- (a) mixing
- (i) a first aqueous dispersion of a cationic dispersing agent with reinforcing fibers, and
- (ii) a second aqueous dispersion containing at least one thermoplastics polymer powder and at least one ionic polymer additive of opposite charge to that of the first dispersion, to form a mixture,
- (b) incorporating into the mixture from 0.5 to 1.5 wt % based on the dry weight of the aqueous suspension of a cationic polyacrylamide flocculating agent, of high molecular weight and of charge opposite to that of said mixture, and
- (c) draining the resulting suspension and drying the resulting semi-finished product.
Dependencies are inferred from the claim text.