BR-112025009642-B1 - Aqueous polymeric latex of a film-forming copolymer, process for the production of an aqueous polymeric latex, use of an aqueous polymeric latex, and water-based coating composition.

BR112025009642B1BR 112025009642 B1BR112025009642 B1BR 112025009642B1BR-112025009642-B1

Abstract

Aqueous polymeric latex of a film-forming copolymer, process for the production of an aqueous polymeric latex, use of an aqueous polymeric latex, and water-based coating composition. The present invention relates to aqueous polymeric latexes of a film-forming copolymer obtained by aqueous emulsion polymerization of ethylenically unsaturated M monomers, comprising 5 to 70% by weight, in particular 10 to 60% by weight, based on the total amount of M monomers, of at least one M1 monomer, which is selected from cyclopentyl acrylate, cyclopentyl methacrylate and mixtures thereof; ii. 20 to 90% by weight, in particular 30 to 80% by weight, based on the total amount of monomers M, of at least one monomer M2, which is selected from C2-C20 alkyl esters of acrylic acid, except tert-butyl acrylate, and C5-C20 alkyl esters of methacrylic acid and mixtures thereof; iii. 0 to 40% by weight, in particular 0 to 35% by weight, based on the total amount of monomers M, of one or more monomers M3, which is selected from tert-butyl acrylate, C1-C4 alkyl esters of methacrylic acid, cyclohexyl methacrylate, isobornyl methacrylate and monovinyl aromatic monomers (...).

Inventors

Friederike Fleischhaker
Andrea Misske
Christoph Fleckenstein
Konrad Roschmann
JEAN-PIERRE BERKAN LINDNER
Felix LAUTERBACH
Arnold LEIDNER
AMIT A GOKHALE

Assignees

BASF SE

Dates

Publication Date: 20260310
Application Date: 20231115
Priority Date: 20221118

Claims (17)

1. Aqueous polymeric latex of a film-forming copolymer, characterized in that it is obtained by aqueous emulsion polymerization of ethylenically unsaturated M monomers, comprising: i. 5 to 70% by weight, based on the total amount of M monomers, of at least one M1 monomer, selected from cyclopentyl acrylate, cyclopentyl methacrylate and mixtures thereof; ii. 20 to 90% by weight, based on the total amount of M monomers, of at least one M2 monomer, selected from C2-C20 alkyl esters of acrylic acid, except tert-butyl acrylate, and C5-C20 alkyl esters of methacrylic acid and mixtures thereof; iii. 0 to 40% by weight, based on the total amount of M monomers, of one or more M3 monomers, which is selected from tert-butyl acrylate, methacrylic acid alkyl esters (C1-C4), cyclohexyl methacrylate, isobornyl methacrylate and monovinyl aromatic monomers and mixtures thereof; wherein the total amount of M1 and M3 monomers is in the range of 5 to 70% by weight, based on the total amount of ethylenically unsaturated M monomers, and wherein the total amount of M1, M2 and M3 monomers is at least 85% by weight, based on the total amount of ethylenically unsaturated M monomers.
2. Aqueous polymeric latex according to claim 1, characterized in that the monomer M1 is cyclopentyl methacrylate.
3. Aqueous polymeric latex according to any of the preceding claims, characterized in that at least the carbon atoms of the cyclopentyl groups in the M1 monomers are of biological origin.
4. Aqueous polymeric latex according to any of the preceding claims, characterized in that the M2 monomers comprise isobutyl acrylate.
5. Aqueous polymeric latex according to claim 4, characterized in that at least the carbon atoms of the isobutyl group of isobutyl acrylate are of biological origin.
6. Aqueous polymeric latex according to claim 4 or 5, characterized in that the amount of isobutyl acrylate is in the range of 20 to 80% by weight, based on the total amount of monomers M.
7. Aqueous polymeric latex according to any of the preceding claims, characterized in that the monomer M3 comprises or is methyl methacrylate or in that the monomer M3 comprises or is styrene.
8. Aqueous polymeric latex according to any of the preceding claims, characterized in that the M monomers additionally comprise at least one M4 monomer, selected from monoethylenically unsaturated monomers with an acid group.
9. Aqueous polymeric latex according to claim 8, characterized in that the M4 monomers are selected from acrylic acid, methacrylic acid, itaconic acid and combinations thereof.
10. Aqueous polymeric latex according to any of the preceding claims, characterized in that the monomers M further comprise at least one non-ionic monoethylenically unsaturated monomer M5, which has a solubility in deionized water at 20°C and 0.1 MPa (1 bar) of at least 60 g/L.
11. Aqueous polymeric latex according to any of the preceding claims, characterized in that the monomers M consist of: i. 5 to 70% by weight, based on the total amount of monomers M, of cyclopentyl methacrylate as monomer M1; ii. 20 to 90% by weight, based on the total amount of monomers M, of at least one monomer M2, which comprises or is isobutyl acrylate or which comprises or is n-butyl acrylate; iii. 0 to 40% by weight, based on the total amount of monomers M, of at least one monomer M3, which is selected from styrene, methyl methacrylate and combinations thereof; iv. 0.05 to 5% by weight, based on the total amount of M monomers, of one or more monoethylenically unsaturated M4 monomers, which is selected from monoethylenically unsaturated monomers with an acid group;v. 0 to 9.95% by weight, based on the total mass of M monomers, of one or more non-ionic M5 monomers with solubility in deionized water at 20°C and 0.1 MPa (1 bar) of at least 60 g/L.
12. Aqueous polymeric latex according to any of the preceding claims, characterized in that the polymeric particles comprise a polymeric phase with a glass transition temperature Tg in the range of -25 to +40 °C, wherein the glass transition temperature is determined by the differential scanning calorimetry (DSC) method, according to ISO 11357-2:2013, preferably with sample preparation according to ISO 16805:2003.
13. Process for the production of an aqueous polymeric latex as defined in any of the preceding claims, characterized in that it comprises carrying out an aqueous emulsion polymerization of the monomers M as defined in any of claims 1 to 11; wherein the aqueous emulsion polymerization by free radicals is initiated by a free radical initiator, which is used in an amount of 0.05 to 2 pphm, based on the total amount of monomers M, wherein the aqueous emulsion polymerization is carried out at a temperature in the range of 0 to 170 °C; and wherein the aqueous emulsion polymerization is conducted at a pressure in the range of 85 Pa (850 mbar) to 1.5 MPa (15 bar).
14. Process according to claim 13, characterized in that the free radical initiator used to initiate aqueous emulsion polymerization is a peroxide or an azo compound, which is used in an amount of 0.1 to 1 ppm, based on the total amount of monomers M, wherein the aqueous emulsion polymerization is carried out in the presence of a seed latex, with the polymeric particles of the seed latex having an average particle diameter Z, determined by dynamic light scattering (DLS) at 20 °C, preferably varying in the range of 10 to 80 nm, in particular from 10 to 50 nm; wherein the seed latex is loaded into the polymerization vessel and subsequently the polymerization conditions are established, preferably by heating the reaction mixture to the polymerization temperature; wherein at least part of the free radical initiator is preferably loaded into the polymerization vessel before the addition of the monomers M begins, or wherein the monomers M and the free radical initiator are added in parallel to the vessel; wherein the amount of seed latex used in the emulsion polymerization, calculated as solids, is preferably in the range of 0.01 to 10% by weight, in particular in the range of 0.05 to 5% by weight, especially in the range of 0.05 to 3% by weight, based on the total weight of monomers M to be polymerized; wherein the aqueous emulsion polymerization is carried out at a temperature in the range of 50 to 120 °C and is preferably conducted at ambient pressure; and wherein the emulsion polymerization is carried out as a single-stage polymerization or a multi-stage polymerization, for example in 2, 3 or 4 stages, in which the composition of the monomers fed to the polymerization reaction under polymerization conditions is changed one, two or three times.
15. Use of an aqueous polymeric latex as defined in any one of claims 1 to 12, characterized in that it acts as a binder in a water-based coating composition.
16. Water-based coating composition, characterized in that it contains a) a binder polymer in the form of aqueous polymeric latex as defined in any one of claims 1 to 12; and b) at least one additional ingredient, conventionally used in water-based coating compositions and which is not a binder.
17. Coating composition according to claim 16, characterized in that it is a latex paint, in particular a latex paint for architectural coatings, a coating for wood or a composition for dyeing wood or a latex paint for interior coatings.

Description

[001] The present invention relates to aqueous copolymer film-forming polymeric latexes obtained by aqueous emulsion polymerization of ethylenically unsaturated M monomers comprising a combination of (meth)acrylate esters as monomers. The present invention also relates to a process for producing such polymeric latexes and to the use of these polymeric latexes as binders in water-based coating compositions. Furthermore, the present invention relates to a water-based coating composition containing a binder polymer in the form of aqueous polymeric latex, as defined herein, and at least one additional ingredient, which is conventionally used in water-based coating compositions and which is not a binder. [002] Polymeric latexes, also called polymeric dispersions, are commonly known, in particular, as a binder or binding component, also called a co-binder, for coating compositions. As a binder or co-binder in coating compositions, one of the important requirements is that they provide hardness and blocking resistance to the coatings and adhesion of the coating to the coated surface. In addition, the polymeric latex must exhibit good opacity, good wet abrasion resistance, good stain removal properties and low dirt absorption, as well as low water absorption. [003] Despite the progress achieved in many aspects, it remains a challenge to provide polymer dispersions with a balanced application profile, since not only the application properties but also the stability of the polymer dispersion must be considered. In particular, it is difficult to reconcile the different coating property requirements simultaneously through the binder. As a rule, attempting to improve one coating property by altering the polymer composition of the binder leads to a significant deterioration of other coating properties. [004] Although the polymeric dispersions described in the technique present specific advantages in one or more aspects, they do not always present a balanced application profile. Furthermore, they are based exclusively on monomers, which are prepared from fossil sources. In view of the ongoing discussion on the impact of CO2 emissions, there is a demand for the reduction of fossil carbon in polymeric lattices. The term “bio-based” means that the monomers are, at least in part, prepared from renewable raw materials, such as plants, plant parts, plant residues, biomass and the like. These products are called “bio-based” and are characterized by having a traceable 14C carbon content. It is also possible that these materials can be converted into suitable raw materials, such as bionaphtha, as described, for example, in EP 2290 045 A1 or EP 2290 034 A1. These raw materials typically enter the chemical production system, such as a steam cracker, where they are converted into products along the chemical value chain, such as acrylic acid, methacrylic acid, acrylic esters, and others. The renewable material content of these products is defined by the mass balance approach and can be allocated to these products. [005] WO 2014/207389 describes the use of 2-octyl acrylate from renewable resources in the production of a polymeric latex. The polymeric latex is suggested as a binder. However, large amounts of 2-octyl acrylate in the monomers that form the latex will result in low glass transition temperatures of the resulting polymer, since 2-octyl acrylate homopolymers have a glass transition temperature below -40 °C. Thus, a latex with an adequate glass transition temperature will require considerable amounts of conventional fossil-derived monomers. [006] WO 2018/118221 describes copolymeric lattices comprising monomers with high biorenewable carbon content, whose homopolymers exhibit high glass transition temperatures, in particular isobornyl methacrylate. However, isobornyl methacrylate can cause problems during emulsion polymerization and result in unstable polymeric lattices (see, for example, O. Llorente et al. Progress in Organic Coatings 172 (2022) 107137). [007] WO 2022/018013 describes polymeric lattices based on acrylate monomers, methacrylate monomers and/or monovinyl aromatic monomers containing a certain amount of monomers selected from isobutyl acrylate and isoamyl acrylate and mixtures thereof. Coating compositions prepared from them result in coatings with enhanced properties such as resistance to bleaching, water absorption and flexibility. Isobutyl acrylate and isoamyl acrylate can be – at least with respect to their alkanol moiety – obtained from biological sources, thus allowing a reduction in fossil carbon in the polymeric lattices. [008] JPH 11171927 A describes an aqueous polymeric dispersion comprising a dicyclopentyl (meth)acrylate-based polymer. This polymer has a number average molecular weight of 1,000 to 1,000,000 and exhibits low odor and high heat resistance. [009] However, there is still a need to provide polymeric lattices that are at least partly based on bio-derived monomers and that have an acceptabl