Claims
- 1. A method of manufacturing fiber-reinforced resin moldings, which comprises the steps of:
- forming an aqueous dispersion consisting essentially of from one to 100 parts by weight of the sum of the weights of the following components A and B, per 100 parts by weight of aqueous dispersing medium,
- A. fibers selected from the group consisting of glass fibers, slag wool fibers and asbestos fibers,
- B. one or a mixture of .alpha.,.beta.-ethylenically unsaturated, radical polymerizable monomers,
- the weight ratio of A/B being such that the polymer-coated fibers obtained by the following polymerization step contain from 5 to 50 weight percent of polymer;
- adding to said dispersion from 0.001 to 10 parts by weight of SO.sub.2, per 100 parts by weight of said monomer B, as essentially the sole polymerization initiator made present in said dispersion, and maintaining said dispersion under polymerizing conditions effective to polymerize said monomer B, while agitating said dispersion, to form a polymer of B as a coating on the surfaces of fibers A,
- recovering from the dispersion polymer-coated fibers composed of from 5 to 50 weight percent of polymer;
- and then compression molding said polymer-coated fibers to form a molded object.
- 2. A method according to claim 1 in which the content of monomer B in said dispersion is from (5/0.95) to (50/0.75) percent by weight, based on the sum of the weights of A plus B.
- 3. A method according to claim 1 in which said fibers consist of glass fibers having diameters of 1 to 2.mu. and lengths of 1 to 50 mm.
- 4. A method according to claim 1 in which said fibers consist of slag wool fibers having diameters of 1 to 2.mu. and lengths of 1 to 50 mm.
- 5. A method according to claim 1 in which said fibers consist of individual asbestos fibers.
- 6. A method according to claim 1 in which said monomer B is selected from the group consisting of halogenated vinyl compounds, styrene and styrene derivatives, vinyl esters of fatty acids, .alpha.,.beta.-ethylenically unsaturated carboxylic acids and alkyl esters thereof, and mixtures thereof.
- 7. A method according to claim 1 in which the sum of the weights of A and B is from 5 to 50 parts by weight, per 100 parts by weight of aqueous dispersing medium.
- 8. A method according to claim 7 in which the amount of sulfur dioxide added to the dispersion is from 0.05 to 5 parts by weight, per 100 parts by weight of monomer B.
- 9. A method according to claim 8 in which polymerization is effected with continuous shaking of the dispersion, at a temperature of 40.degree. to 70.degree.C, for from 0.5 to 5 hours.
- 10. A method according to claim 9 in which the polymer-coated fibers contain from 5 to 35 percent by weight of polymer.
- 11. A method according to claim 10 in which said monomer B is selected from the group consisting of methylmethacrylate, styrene and vinyl chloride.
Priority Claims (1)
Number |
Date |
Country |
Kind |
47-19543 |
Feb 1972 |
JA |
|
RELATED APPLICATION
This application is a continuation-in-part of pending application Ser. No. 334,663 filed under dated of Feb. 22, 1973, now abandoned.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
3265644 |
Herman et al. |
Aug 1966 |
|
3635879 |
Baer et al. |
Jan 1972 |
|
3661620 |
Dekking |
May 1972 |
|
3808174 |
Yamaguchi et al. |
Apr 1974 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
334663 |
Feb 1973 |
|