Aqueous polymer compositions for flexible roof coatings

Patent metadata

Field	Value
Publication number	US-11674048-B2
Application number	US-201816643079-A
Country	US
Kind code	B2
Filing date	Aug 29, 2018
Priority date	Aug 30, 2017
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

The present invention relates to the use of liquid aqueous polymer compositions containing an aqueous polymer latex and at least one inorganic particulate material for providing flexible roof coatings. The present invention also relates to a method for providing flexible roof coatings, which comprises applying said liquid aqueous polymer compositions to a flat roof. The liquid aqueous polymer composition contain, a. an aqueous polymer latex, where the polymer in the polymer latex is made of polymerized monomers M, where the polymerized ethylenically unsaturated monomers M comprise a combination of) at least two different monoethylenically unsaturated, non-ionic monomers M1, whose homopolymers have a theoretical glass transition temperature T g (th) of at least 25° C. and ii) at least two different monoethylenically unsaturated, non-ionic monomers M2, whose homopolymers have a theoretical glass transition temperature T g (th) of at less than 25° C., where each of the monomers M1 and M2 have a solubility in deionized water of at most 50 g/L and where the total amount of monomers M1 and M2 contributes with at least 90% by weight to the total amount of the monomers M, and b. at least one inorganic particulate material selected from inorganic pigments, inorganic fillers and mixtures thereof.

First claim

The invention claimed is:

1. A method for providing a flexible roof coating, the method comprising obtaining a liquid aqueous polymer composition comprising:
a. an aqueous polymer latex, where a polymer in the aqueous polymer latex comprises ethylenically unsaturated monomers M, where the ethylenically unsaturated monomers M comprise a combination of
i) at least two different monoethylenically unsaturated, non-ionic monomers M1, whose homopolymers have a theoretical glass transition temperature T g (th) of at least 25° C. and
ii) at least two different monoethylenically unsaturated, non-ionic monomers M2, whose homopolymers have a theoretical glass transition temperature T g (th) of less than 25° C.,
where each of the monomers M1 and M2 have a solubility in deionized water of at most 50 g/L and where a total amount of the monomers M1 and M2 contributes at least 90% by weight to a total amount of the monomers M, and
where the aqueous polymer latex is prepared by free radical aqueous emulsion polymerization of the ethylenically unsaturated monomers M, which form the aqueous polymer latex, in the presence of at least one surfactant and at least one polymerization initiator and optionally in the presence of a seed latex, where an amount of seed latex, if present, is in a range from 0.1 to 10% by weight, calculated as solids and based on a total weight of the monomers M to be polymerized; and
b. at least one inorganic particulate material selected from inorganic pigments, inorganic fillers and mixtures thereof, wherein the liquid aqueous polymer composition has a pigment volume concentration (PVC) of from 15% to 50%,
and, wherein, when applying the liquid aqueous polymer composition to a surface of a substrate to be coated with an application rate of from 750 to 3,500 g/m 2 an average coating thickness of 450 to 2,000 μm, calculated on a dry film basis is achieved.

2. The method of claim 1 , where the monomers M1 have a T g (th) of at least 50° C. and where the monomers M2 have a T g (th) of at most −20° C.

3. The method of claim 1 , where the monomers M1 are a combination of:
at least one monomer M1a, which is selected from vinylaromatic hydrocarbon monomers and C 5 -C 6 -cycloalkyl methacrylates; and
at least one monomer M1b, which is selected from C 1 -C 4 -alkyl esters of methacrylic acid and tert-butyl acrylate.

4. The method of claim 1 , where the monomers M1 comprise styrene, and where styrene contributes 10 to 35% by weight to the total amount of the monomers M.

5. The method of claim 3 , where a weight ratio of the at least one monomer M1a to the at least one monomer M1b is from 3:1 to 1:3.

6. The method of claim 1 , where a total amount of the monomers M1 contributes 25 to 70% by weight to the total amount of the monomers M.

7. The method of claim 1 , where the monomers M2 are a combination of at least two different C 2 -C 12 -alkyl acrylates, except for tert-butyl acrylate.

8. The method of claim 1 , where each of the monomers M2 contributes at least 10% by weight to the total weight of the monomers M, and where a total amount of the monomers M2 contributes 20 to 75% by weight to the total amount of the monomers M.

9. The method of claim 1 , where the monomers M comprise at least one further monoethylenically unsaturated monomer, which is selected from the group consisting of:
monomers M3, which are selected from the group consisting of monoethylenically unsaturated C 3 -C 6 -monocarboxylic acids, monoethylenically unsaturated C 4 -C 6 -dicarboxylic acids, primary amides of monoethylenically unsaturated C 3 -C 6 -monocarboxylic acids, and hydroxy-C 2 -C 4 -alkyl esters of monoethylenically unsaturated C 3 -C 6 -monocarboxylic acids and mixtures thereof,
monomers M4, which are selected from the group consisting of monoethylenically unsaturated monomers having at least one keto group and monoethylenically unsaturated monomers having at least one oxirane group and mixtures thereof, and
monomers M5, which are selected from the group consisting of monoethylenically unsaturated monomers having a silane group.

10. The method of claim 1 , where the monomers M comprise
from 25 to 70% by weight, based on a total weight of the monomers M, of a combination at least two monomers M1;
from 20 to 75% by weight, based on the total weight of the monomers M, of a combination at least two monomers M2;
from 0.1 to 10% by weight, based on the total weight of the monomers M, of one or more monoethylenically unsaturated monomers, selected from the group consisting of
one or more monomers M3a in an amount of at most 5% by weight, based on the total amount of the monomers M, which are selected from the group consisting of monoethylenically unsaturated C 3 -C 6 -monocarboxylic acids and monoethylenically unsaturated C 4 -C 6 -dicarboxylic acids,
one or more monomers M3b in an amount of at most 5% by weight, based on the total amount of the monomers M, which are selected from the group consisting of primary amides of monoethylenically unsaturated C 3 -C 6 -monocarboxylic acids, and hydroxy-C 2 -C 4 -alkyl esters of monoethylenically unsaturated C 3 -C 6 -monocarboxylic acids and mixtures thereof,
one or more monomers M4 in an amount of at most 5% by weight, based on the total amount of the monomers M, which are selected from the group consisting of monoethylenically unsaturated monomers having at least one ketogroup and monoethylenically unsaturated monomers having at least one oxirane group and mixtures thereof, and
one or more monomers M5 in an amount of at most 2% by weight, based on the total amount of the monomers M, which are selected from the group consisting of monoethylenically unsaturated monomers having a silane group.

11. The method of claim 1 , where the polymer has a glass transition temperature T g in a range from −20° C. to +40° C., where the glass transition temperature is determined by differential scanning calorimetry using a heating rate of 20 K/min and applying a midpoint measurement in accordance with ISO 11357-2:2013-05.

12. The method of claim 1 , where the liquid aqueous polymer composition comprises at least one inorganic filler selected from the group consisting of natural calcium carbonates, synthetic calcium carbonates, calcium silicates, aluminum silicates and alkalimetal silicates.

13. The method of claim 12 , where the at least one inorganic filler comprises particles and at least 90% by weight of the particles of the at least one inorganic filler have a particle size in a range from 0.1 to 25 μm, as determined by laser diffraction in accordance with ISO 13320:2009.

14. The method of claim 13 , where at least 50% by weight of the particles of the at least one inorganic filler have a particle size in a range from 0.1 to 2 μm, as determined by laser diffraction in accordance with ISO 13320:2009.

15. The method of claim 12 , where the liquid aqueous polymer composition additionally comprises at least one inorganic white pigment.

16. The method of claim 1 , where the pigment volume concentration PVC is in a range from 20 to 450.

17. A method for providing a flexible roofing, the method comprising applying the liquid aqueous polymer composition as defined in claim 1 as a coating to a flat roof having an inclination of not more than 15°.

Assignees

• Basf Se

Inventors

• Jahns Ekkehard
• Mangel Timo
• Burk Yeni
• Pakusch Joachim

Classifications

• C08L25/06

  Polystyrene · CPC title

• C09D133/08 Primary

  Homopolymers or copolymers of acrylic acid esters · CPC title

• C08K3/30

  Sulfur-, selenium- or tellurium-containing compounds · CPC title

• C08F20/12

  of monohydric alcohols or phenols · CPC title

• C08L35/06

  Copolymers with vinyl aromatic monomers · CPC title