Claims
- 1. Cellulose fibers cross-linked with formaldehyde by the process comprising the steps of
- (1) spraying of formaldehyde as a mixture with hydrochloric acid and formic acid on individualized cellulose fibers;
- (2) immediately after said spraying, introducing said fibers which have the reagents of step (1) uniformly disposed thereon into an air stream having a temperature of from about 60.degree. and about 250.degree. C., and a velocity of from about 1-20 m/sec during a curing-time period ranging between about 1 and 20 seconds to effect a cross-linking reaction; and
- (3) separating said fibers from said air stream.
- 2. The fibers obtained by the process according to claim 1 further characterized in that the air stream has a temperature between about 170.degree. and 180.degree. C.
- 3. The fibers obtained by the process according to claim 1 further characterized in that said individualized fibers are obtained through the step of fluffing crude and compacted pulp.
- 4. The fibers obtained by the process according to claim 3 further characterized in that the steps from fluffing to separating of said fibers from said air stream are carried out within less than one minute time.
- 5. The fibers obtained by the process according to claim 3 further characterized in that the fluffed pulp is heated.
- 6. The fibers obtained by the process according to claim 1 further characterized in that the amount of formic acid used in the mixture is less than 50% by weight with respect to the reagents.
- 7. The fibers obtained by the process according to claim 6 further characterized in that the amount of formic acid used is less than 12% by weight with respect to the fibers.
- 8. The fibers obtained by the process according to claim 1 further characterized in that the amount of hydrochloric acid used is from trace amounts and 2% by weight with respect to the fibers.
- 9. The fibers obtained by the process according to claim 1 further characterized in that the fibers are retained in the air stream for about 2 to 3 seconds.
- 10. Cellulose fibers cross-linked with formaldehyde, at least 50% of the cross-linking bridges being at the surface area of the fibers, thereby imparting flexibility and softness to the fibers.
Priority Claims (1)
Number |
Date |
Country |
Kind |
75 31965 |
Oct 1975 |
FRX |
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Parent Case Info
This application is a continuation-in-part of application Ser. No. 731,895 filed Oct. 13, 1976, now U.S. Pat. No. 4,113,936 issued on Sept. 12, 1978.
US Referenced Citations (12)
Non-Patent Literature Citations (1)
Entry |
Chemical Abstracts, vol. 82, No. 14, Apr. 7, 1975, p. 87968M. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
731895 |
Oct 1976 |
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