Claims
- 1. In a process for the manufacture of urea-formaldehyde condensation products the improvement according to which highly disperse, solid urea-formaldehyde condensation products are formed which contain sulpho groups and consist of compact, spherical, agglomerated primary particles having a diameter of less than 1 .mu.m, the process comprising polycondensing a precondensate (P) of urea and formaldehyde said precondensate being a cocondensate in which up to one-third of the urea is replaced by the corresponding molar amount of a comonomer selected from the group consisting of phenol, resorcinol, a cresol, salicylic acid, an acid amide, biuret, a hydantoin and a mixture thereof and a condensation polymer (N) of naphthalenesulphonic acid and formaldehyde in aqueous solution at temperatures of 20.degree. to 100.degree. C to form a gel, the components being added in such ratio that the molar ratio of formaldehyde to urea and the comonomer in the reaction mixture at the moment of gelling is 1.25 to 2, these molar ratios taking into account both the free starting products, formaldehyde, urea and comonomer, and the monomeric starting products chemically bound in the intermediate products.
- 2. A process according to claim 1 wherein up to one-third of the urea is replaced by the corresponding molar amount of the comonomer by employing a precondensate (P) of a correspondingly lower urea content and adding the particular comonomer to the reaction mixture before or during the polycondensation.
- 3. Highly disperse solid urea-formaldehyde condensation polymers which contain sulpho groups, consist of compact, spherical, agglomerated primary particles of diameter less than 1 .mu.m, and are manufactured in accordance with the process of claim 1.
- 4. Pulverulent urea-formaldehyde condensation polymers according to claim 3, wherein the products have a specific surface area of 5 to 100 m.sup.2 /g, a sulphur content of 0.2 to 2.0% by weight and an average diameter of the primary particles of 0.04 to 1 .mu.m.
- 5. Urea-formaldehyde condensation polymers according to claim 3, the molar ratio of comonomer to urea being up to 1/2.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7809/74 |
Jun 1974 |
CH |
|
Parent Case Info
This application is a division of application Ser. No. 576,938, filed May 12, 1975, now U.S. Pat. No. 4,010,132
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
2944046 |
Sellet |
Jul 1960 |
|
3553115 |
Curchod et al. |
Jan 1971 |
|
Foreign Referenced Citations (6)
Number |
Date |
Country |
315,493 |
Sep 1973 |
OE |
1,907,914 |
Oct 1969 |
DT |
1,361,045 |
Jul 1974 |
UK |
515,517 |
Dec 1939 |
UK |
1,318,244 |
May 1973 |
UK |
462,846 |
Aug 1975 |
SU |
Non-Patent Literature Citations (2)
Entry |
Renner, Die Makromolekulare Chemie, 149, (1971). |
Billmeyer, Textbook of Polymer Science, Interscience Publishers, N.Y. (1962), pp. 326-330. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
576938 |
May 1975 |
|