Chlorinated vinyl resin/cellulosic blends: compositions, processes, composites, and articles therefrom
First Claim
1. A process for preparing an extrudable powder blend comprising the steps of:
- (I) blending a mixture comprising the following components;
(a) from 30 to 65 weight percent of at least one chlorinated vinyl resin;
(b) from 0.25 to 5 weight percent of at least one thermal stabilizer;
(c) from 1.5 to 5 weight percent of at least one lubricant;
(d) from 3.5 to 15 weight percent of at least one high molecular weight polymer processing aid; and
(e) from 24 to 65 weight percent of at least one cellulosic material containing moisture, based upon the total weight of the powder blend;
(II) raising the temperature above 50°
C. during the (I) blending step; and
(III) removing water vapor.
1 Assignment
0 Petitions
Accused Products
Abstract
Compositions and processes for preparing extrudable powder blends containing at least one vinyl chloride resin and a cellulosic material are provided. More specifically, compositions and processes for preparing extrudable free-flowing powder blends containing PVC and wood flour (WF) are also provided for preparing foamed or nonfoamed extrudates. The processes provided herein incorporate components which may contain up to a total of 25 weight percent water. Processes for preparing foamed extrudates are also provided wherein a cooling fluid is used to increase the expansion ratio of the foam. Finally provided are composites having an extrudable thermoplastic substrate and at least one capstock layer disposed thereon containing a PVC/WF composition.
145 Citations
11 Claims
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1. A process for preparing an extrudable powder blend comprising the steps of:
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(I) blending a mixture comprising the following components;
(a) from 30 to 65 weight percent of at least one chlorinated vinyl resin;
(b) from 0.25 to 5 weight percent of at least one thermal stabilizer;
(c) from 1.5 to 5 weight percent of at least one lubricant;
(d) from 3.5 to 15 weight percent of at least one high molecular weight polymer processing aid; and
(e) from 24 to 65 weight percent of at least one cellulosic material containing moisture, based upon the total weight of the powder blend;
(II) raising the temperature above 50°
C. during the (I) blending step; and
(III) removing water vapor. - View Dependent Claims (2, 3)
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4. A process for preparing an extrudable free-flowing powder blend comprising the steps of:
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(I) blending a mixture comprising the following components;
(a) from 40 to 55 weight percent of at least one PVC resin;
(b) from 0.5 to 1.5 weight percent of at least one thermal stabilizer;
(c) from 1.5 to 3 weight percent of at least one lubricant;
(d) from 5 to 10 weight percent of at least one high molecular weight polymer processing aid;
(e) from 34 to 52 weight percent of at least one wood flour containing moisture;
(f) from 3 to 15 weight percent of at least one mineral filler; and
(g) up to 3 weight percent of at least one blowing agent, based upon the total weight of the powder blend;
(II) raising the temperature above 80°
C. during the (I) blending step; and
(III) removing water vapor so that the final moisture amount in of the powder blend is below 2.0 weight percent, based upon the total weight of the powder blend. - View Dependent Claims (5, 6, 7, 8, 9)
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10. A process for preparing a foamed extrudate comprising the steps of:
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(I) feeding an extrudable free-flowing powder blend, comprising at least one chlorinated vinyl resin, at least one blowing agent, and from 24 to 65 weight percent of at least one cellulosic material containing moisture, based upon the total weight of the powder blend, into an extruder;
(II) melting the powder blend to form a melt;
(III) extruding the melt from a die to form an expanding extrudate having at least one surface; and
(IV) hardening the surface of the expanding extrudate with a cooling fluid to increase the expansion ratio. - View Dependent Claims (11)
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Specification