COPOLYMERS HAVING A GRADIENT STRUCTURE

• US 20200131089A1
• Filed: 12/12/2019
• Published: 04/30/2020
• Est. Priority Date: 09/24/2015
• Status: Active Grant

• Current Assignee: Sika Technology Ag (Compagnie de Saint-Gobain SA)
• Original Assignee: Sika Technology Ag (Compagnie de Saint-Gobain SA)
• Inventors: WEIDMANN, Jurg, ZIMMERMANN, Jorg
• Granted Patent: US 11,066,330 B2
• Time in Patent Office: Days
• CPC Class Codes: C04B 2103/0063 obtained by an unusual polymerisation process, e.g. by changing the molar ratio of the different monomers during the polymerisation process C04B2103/0058 - C04B2103/0061 take precedence
• CPC Class Codes: C04B 2103/408 Dispersants
• CPC Class Codes: C04B 24/165 containing polyether side chains
• CPC Class Codes: C04B 24/246 containing polyether side chains
• CPC Class Codes: C04B 24/2605 containing polyether side chains
• CPC Class Codes: C04B 24/2647 containing polyether side chains
• CPC Class Codes: C04B 24/2658 containing polyether side chains
• CPC Class Codes: C04B 24/267 containing polyether side chains
• CPC Class Codes: C04B 24/2694 containing polyether side chains

Abstract

The present invention relates to a copolymer, especially for use as a dispersant for solid particles, in particular for use as dispersant for mineral binder compositions, having a polymer backbone and side chains bonded thereto, comprising at least one ionizable monomer unit M1 and at least one side chain-bearing monomer unit M2, wherein the copolymer has a gradient structure in at least one section A in a direction along the polymer backbone with regard to the ionizable monomer unit M1 and/or with regard to the side chain-bearing monomer unit M2.

Claims

1. A copolymer having a polymer backbone and side chains bonded thereto, and comprising at least one ionizable monomer unit M1 and at least one side chain-bearing monomer unit M2, the copolymer having:

at least one section A having a gradient structure in a direction along the polymer backbone with regard to the ionizable monomer unit M1 and/or with regard to the side chain-bearing monomer unit M2, and

at least one section B having an essentially constant local concentration of monomers and/or a random distribution of monomers, wherein the at least one section B comprises ionizable monomer units M1 and/or side chain-bearing monomer units M2,

wherein a ratio of the number of monomer units in the at least one section A to the number of monomer units in the at least one section B is in the range of 80;

20 to 20;

80.

2. The copolymer as claimed in claim 1, wherein the polydispersity of the copolymer is <

1.5.

3. The copolymer as claimed in claim 1, wherein the polydispersity of the copolymer is in the range of 1.0-1.4.

4. The copolymer as claimed in claim 1, wherein the at least one section A has a proportion of at least 30% of monomer units, based on a total number of the monomer units in the polymer backbone.

5. The copolymer as claimed in claim 1, wherein the at least one section A has a proportion of at least 50% of monomer units, based on a total number of the monomer units in the polymer backbone.

6. The copolymer as claimed in claim 1, wherein the ratio of the number of monomer units in the at least one section A to the number of monomer units in the at least one section B is in the range of 70:

30 to 30;

70.

7. The copolymer as claimed in claim 1, wherein the at least one section B, based on all the monomer units present therein, comprises at least 30 mol % of side chain-bearing monomer units M2, and any proportion of ionizable monomer units M1 present in the at least one section B is less than 25 mol % based on all the monomer units M2 in the at least one section B.

8. The copolymer as claimed in claim 1, wherein the at least one section B comprises a total of 5-70 monomer units.

9. The copolymer as claimed in claim 1, wherein the at least one section B comprises a total of 7-40 monomer units.

10. The copolymer as claimed in claim 1, wherein the at least one section A comprises 5-70 monomer units M1 and 5-70 monomer units M2.

11. The copolymer as claimed in claim 1, wherein the at least one section A comprises 7-40 monomer units M1 and 7-40 monomer units M2.

12. The copolymer as claimed in claim 1, wherein the at least one section A, based on the weight-average molecular weight of the overall copolymer, has a proportion by weight of at least 30%.

13. The copolymer as claimed in claim 1, wherein the at least one section A directly adjoins the at least one section B.

14. The copolymer as claimed in claim 1, wherein the ionizable monomer unit M1 has a structure of the following formula (I)

15. The copolymer as claimed in claim 14, wherein n=10-200.

16. The copolymer as claimed in claim 14, wherein:

R¹=—

COOM;

R² and R⁵, independently of one another, are —

H, —

CH₃, or mixtures thereof;

R³ and R⁶, independently of one another, are —

H or —

CH₃;

R⁴ and R⁷ independently of one another, are —

H or —

COOM; and

X in at least 75 mol % of all monomer units M2 is —

O—

.

17. The copolymer as claimed in claim 13, wherein:

R¹=—

COOM;

R² and R⁵ are —

CH₃;

R³ and R⁶ are —

H;

R⁴ and R⁷ are —

H;

X in at least 99 mol % of all monomer units M2 is —

O—

; and

m=0, p=1, and n=19-45.

18. The copolymer as claimed in claim 1, wherein a weight-average molecular weight M_W of the overall copolymer is in the range of 12,000-80,000 g/mol.

19. The copolymer as claimed in claim 1, wherein a weight-average molecular weight M_W of the overall copolymer is in the range of 12,000-50,000 g/mol.

20. A method for dispersing solid particles, comprising mixing the copolymer as claimed in claim 1 with solid particles.

21. A mineral binder composition comprising at least one copolymer as claimed in claim 1.

22. A shaped body obtained by curing a mineral binder composition as claimed in claim 21 after addition of water.