Polymer-modified cementitious composition

Patent metadata

Field	Value
Publication number	US-11352296-B2
Application number	US-201817051022-A
Country	US
Kind code	B2
Filing date	Apr 28, 2018
Priority date	Apr 28, 2018
Publication date	Jun 7, 2022
Grant date	Jun 7, 2022

Abstract

A polymer-modified cementitious composition comprising a specific aqueous polymer dispersion and a cementitious material, and such polymer-modified cementitious composition having low ammonia release and providing coating membranes made therefrom with balanced tensile strength and elongation at break.

First claim

What is claimed is:

1. A polymer-modified cementitious composition, comprising:
(A) an aqueous polymer dispersion comprising a polymer, wherein the polymer comprises, by weight based on the weight of the polymer,
(a) more than 1% and up to 1.45% of structural units of a carboxylic acid monomer,
(b) from 2% to 6% of structural units of a hydroxy-functional alkyl (meth)acrylate,
(c) from 15% to 45% of structural units of a vinyl aromatic monomer,
(d) from 50% to 80% of structural units of an additional alkyl (meth)acrylate, and
(e) less than 0.1% of structural units of (meth)acrylamide; and
(B) a cementitious material.

2. The polymer-modified cementitious composition of claim 1 , wherein the polymer comprises, by weight based on the weight of the polymer, from 1.1% to 1.4% of structural units of the carboxylic acid monomer.

3. The polymer-modified cementitious composition of claim 1 , wherein the carboxylic acid monomer comprises a carboxylic acid functional (meth)acrylate having the structure of formula (I),

where n is an integer of from 1 to 12, and R 1 and R 2 are each independently hydrogen or methyl.

4. The polymer-modified cementitious composition of claim 3 , wherein the polymer comprises, by weight based on the weight of the polymer, from 0.3% to 1.45% of structural units of the carboxylic acid functional (meth)acrylate.

5. The polymer-modified cementitious composition of claim 1 , wherein the carboxylic acid monomer is selected from the group consisting of acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, 2-carboxypropyl methacrylate, 2-carboxypropyl acrylate and itaconic acid.

6. The polymer-modified cementitious composition of claim 5 , wherein the polymer comprises, by weight based on the weight of the polymer, from 0.1% to 0.5% of structural units of itaconic acid.

7. The polymer-modified cementitious composition of claim 1 , wherein the additional alkyl (meth)acrylate is a C 1 -C 4 -alkyl (meth)acrylate.

8. The polymer-modified cementitious composition of claim 1 , wherein the polymer has a Tg in the range of from −25 to −5° C.

9. The polymer-modified cementitious composition of claim 1 , wherein the polymer comprises, by weight based on the weight of the polymer,
from 1.1% to 1.35% of structural units of the carboxylic acid monomer selected from the group consisting of acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, 2-carboxypropyl methacrylate, 2-carboxypropyl acrylate and itaconic acid;
from 3% to 5% of structural units of the hydroxy-functional alkyl (meth)acrylate selected from the group consisting of 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate;
from 20% to 30% of structural units of styrene; and
from 65% to 75% of structural units of the additional alkyl (meth)acrylate selected from the group consisting of methyl acrylate, methyl methacrylate, butyl acrylate, and butyl methacrylate.

10. The polymer-modified cementitious composition of claim 1 , further comprising a filler, a defoamer, a thickener, a dispersant, or mixtures thereof.

11. A method of preparing a polymer-modified cementitious composition, comprising admixing an aqueous polymer dispersion comprising a polymer with a cementitious material, wherein the polymer comprises, by weight based on the weight of the polymer,
(a) more than 1% and up to 1.45% of structural units of a carboxylic acid monomer,
(b) from 2% to 6% of structural units of a hydroxy-functional alkyl (meth)acrylate,
(c) from 15% to 45% of structural units of a vinyl aromatic monomer,
(d) from 50% to 80% of structural units of an additional alkyl (meth)acrylate, and
(e) less than 0.1% of structural units of (meth)acrylamide.

Assignees

• Dow Global Technologies Llc

Inventors

• Chen Jitao
• Li Yan
• Shi Ke
• Wang Tao
• Sun Tong
• Feng Shaoguang
• Zhang Xiaohong

Classifications

• C04B28/04

  Portland cements · CPC title

• C04B24/2641 Primary

  Polyacrylates; Polymethacrylates · CPC title

• C04B2103/44

  Thickening, gelling or viscosity increasing agents · CPC title

• C04B2111/27

  Water resistance, i.e. waterproof or water-repellent materials · CPC title

• C04B2103/408

  Dispersants · CPC title