Process for the preparation of a thixotropic composition

Patent metadata

Field	Value
Publication number	US-11261284-B2
Application number	US-201716339749-A
Country	US
Kind code	B2
Filing date	Nov 7, 2017
Priority date	Nov 7, 2016
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

The invention relates to a process for the preparation of a thixotropic composition comprising polyurea particles, said process comprising contacting and reacting in a liquid medium reactants to form a polyurea and precipitating the polyurea to form polyurea particles, wherein acoustic vibration is applied during contacting of the reactants or as a post-treatment on the formed polyurea particles or both. The invention further relates to a thixotropic composition obtainable by the process, in particular thixotropic composition comprising high amounts of polyurea particles and optionally a polymer resin having high thixotropic efficiency. The compositions can be used, in particular as a masterbatch, in preparation of i.a. coating compositions.

First claim

What is claimed is:

1. A process for the preparation of a thixotropic composition comprising polyurea particles, said process comprising:
contacting and reacting in a liquid medium, reactants (I) comprising a polyisocyanate (a) and a mono-amine (b), or reactants (II) comprising a polyamine (a) and a mono-isocyanate (b) to form a polyurea, and
precipitating the polyurea to form polyurea particles, wherein acoustic vibration is applied during contacting of the reactants or as a post-treatment on the formed polyurea particles or both,

wherein the reaction takes place in the liquid medium in substantial absence of a polymeric resin material, and the thixotropic composition comprises at least 4 wt % of the polyurea particles relative to the total weight of the thixotropic composition and substantially no polymeric resin material;
or
wherein the polyurea particles are formed in the presence of the polymeric resin material, and the thixotropic composition comprises between 1 and 40 wt % of the polymeric resin material and at least 4 wt % of the polyurea particles relative to the total weight of the thixotropic composition including the polymeric resin material;
or
wherein the reaction takes place in a resin composition comprising between 40 wt % and 85 wt % of the polymeric resin material as a binder, and the thixotropic composition comprises between 0.1 and 8 wt % of the polyurea particles, wherein the wt % are relative to the total weight of the thixotropic composition.

2. The process according to claim 1 , wherein acoustic vibration is applied both during the contacting of the reactants and, as a post-treatment, on the formed polyurea particles.

3. The process according to claim 1 , wherein temperature during the contacting and/or in the post-treatment is lower than 80° C.

4. The process according to claim 1 , wherein the acoustic vibration is sonic vibration applied either indirectly or directly.

5. The process according to claim 1 , wherein the acoustic vibration has an energy density E1 of more than 5 W/l, where the energy density is the gross power of the ultrasonic unit(s) divided by the total volume of liquid being exposed to the ultrasound, or
wherein the acoustic vibration has an energy density E2 of more than 5 W/l, where the energy density is the gross power of the ultrasonic unit(s) divided by the total volume of thixotropic composition being exposed to the ultrasound.

6. The process according to claim 1 , wherein the reactants and the formed polyurea particles are also subjected to stirring.

7. The process according to claim 1 , wherein the reaction takes place in the liquid medium in substantial absence of the polymeric resin material, and the thixotropic composition comprises at least 6 wt %, and less than 40 wt % of the polyurea particles relative to the total weight of the thixotropic composition and substantially no polymeric resin material.

8. The process according to claim 1 , wherein the polyurea particles are formed in the presence of the polymeric resin material, and the thixotropic composition comprises between 1 and 25 wt % of the polymeric resin material and at least 4 wt % of the polyurea particles relative to the total weight of the thixotropic composition including polymeric resin material.

9. The process according to claim 1 , wherein the reaction takes place in the resin composition comprising between 40 wt % and 85 wt % of the polymeric resin material as the binder, and the thixotropic composition comprises between 0.1 and 5 wt % of the polyurea particles, wherein the wt % are relative to the total weight of the thixotropic composition.

10. The process according to claim 1 , wherein acoustic vibration is applied only as a post treatment to the thixotropic composition or to a coating composition comprising polyurea particles.

11. A thixotropic composition obtained by the process of claim 1 .

12. The thixotropic composition of claim 11 comprising A) at least 5 wt % of polyurea particles and comprising substantially no polymeric resin, or B) comprising at least 5 wt % of polyurea particles and between 1 and 40 wt % of polymeric resin, wherein the wt % is relative to the total weight of the thixotropic composition, and wherein the thixotropic composition, when tested at a concentration of 1.5 wt % polyurea particles based on total solids weight, has a reduced compliance lower than 50% and a Hegman fineness value of less than 40 μm.

13. The thixotropic composition of claim 11 , wherein at least part of the polyurea particles is prepared from a di-isocyanate and benzylamine or wherein at least part of the polyurea particles is prepared from chiral amines or chiral isocyanates.

14. The thixotropic composition of claim 11 comprising a liquid medium selected from the group consisting of a solvent, a reactive diluent, a low molecular weight resin, and combinations thereof.

15. A method for the preparation of a coating-, gel coat-, paint-, adhesive-, ink- or sealant composition comprising the step of adding the thixotropic composition of claim 11 to the coating-, gel coat-, paint-, adhesive-, ink- or sealant composition.

16. A coating composition prepared from the thixotropic composition according to claim 11 .

17. A cured coating prepared from the coating composition of claim 16 .

18. The process of claim 1 , wherein the liquid medium is selected from the group consisting of a solvent, a reactive diluent, a low molecular weight resin and combinations thereof.

19. A coating composition comprising polyurea particles from the thixotropic composition according to claim 11 .

20. A cured coating prepared from the coating composition of claim 19 .

21. The thixotropic composition of claim 11 comprising:
A) at least 5 wt % of polyurea particles and comprising substantially no polymeric resin, wherein at least part of the polyurea particles is prepared from reactants (I) comprising the polyisocyanate (a) and the mono-amine (b), or reactants (II) comprising the polyamine (a) and the mono-isocyanate (b), wherein the mono-amine (b) or mono-isocyanate (b) are chiral.

22. The thixotropic composition of claim 21 , wherein at least part of the polyurea particles is prepared from reactants (I), and wherein the polyisocyanate (a) is hexamethylene diisocyanate and the chiral mono-amine (b) is alpha-methylbenzylamine.

23. The thixotropic composition of claim 22 , wherein first polyurea particles are prepared and are a reaction product of the polyisocyanate (a), which is hexamethylene diisocyanate and the chiral mono-amine (b), which is alpha-methylbenzylamine, and
second polyurea particles are formed and precipitated in the presence of the first polyurea particles, wherein the second polyurea particles are a reaction product of the polyisocyanate (a), which is hexamethylene diisocyanate and the mono-amine (b) which is benzylamine.

24. The thixotropic composition of claim 11 comprising:
B) at least 5 wt % of polyurea particles and between 1 and 40 wt % of polymeric resin, wherein the wt % are relative to the total weight of the thixotropic composition, and wherein the polyurea particles are prepared from reactants (I) comprising the polyisocyanate (a) and a non-chiral mono-amine (b) or reactants (II) comprising the polyamine (a) and a non-chiral mono-isocyanate (b).

25. The thixotropic composition of claim 24 , wherein the polyisocyanate (a) is hexamethylene diisocyanate and the non-c

Assignees

• Allnex Netherlands Bv

Inventors

• Bosma Martin
• Elfrink Petrus Johannes Maria David
• Rensen Enrico Richardus August
• Brinkhuis Richard Hendrikus Gerrit

Classifications

• C08G18/2865 Primary

  Compounds having only one primary or secondary amino group; Ammonia · CPC title

• C09K3/10

  {Materials in mouldable or extrudable form} for sealing or packing joints or covers (filling pastes C09D5/34) · CPC title

• C08J3/226

  using a polymer as a carrier · CPC title

• C08J3/28

  Treatment by wave energy or particle radiation · CPC title

• C08G18/73

  acyclic · CPC title