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EP-4608922-B1 - RHEOLOGY MODIFIER FOR IMPROVED VISCOSITY LOSS ON TINTING IN PAINT FORMULATIONS CONTAINING ORGANO-PHOSPHORUS-FUNCNTIONALIZED LATEXES

EP4608922B1EP 4608922 B1EP4608922 B1EP 4608922B1EP-4608922-B1

Inventors

  • RILEY, John K.
  • Rabasco, John J.

Dates

Publication Date
20260513
Application Date
20231211

Claims (12)

  1. A composition comprising: (i) polymer particles comprising structural units of an organo-phosphorus monomer; and (ii) a hydrophobically modified oxyalkylene-urethane polymer having a hydrophobic fragment represented by Structure I: where the dotted line represents the point of attachment of the fragment to the hydrophobically modified oxyalkylene-urethane polymer; Ar 1 is unsubstituted phenyl, naphthyl, phenyl-O-CH 2 -, phenyl-CH 2 -O-CH 2 -, or naphthyl-O-CH 2 -; or phenyl, naphthyl, phenyl-O-CH 2 -, phenyl-CH 2 -O-CH 2 -, or naphthyl-O-CH 2 -substituted with from 1 to 3 C 1 -C 6 alkyl or alkoxy groups; Ar 2 is phenyl, phenyl-OCH 2 CH 2 -, phenyl-(OCH 2 CH 2 ) y -, benzyl, naphthyl, naphthyl-CH 2 -, naphthyl-OCH 2 CH 2 - or naphthyl-(OCH 2 CH 2 ) y -, wherein the phenyl or naphthyl portion of Ar 2 is unsubstituted or substituted with from 1 to 3 C 1 -C 6 alkyl groups, and wherein y is from 2 to 10; each R 1 is independently H or C 1 -C 6 -alkyl; X is O or NR 2 , wherein R 2 is H, C 1 -C 6 -alkyl, phenyl, or benzyl; m is from 1 to 20; and n is from 0 to 100.
  2. The composition of Claim 1 wherein the organo-phosphorus monomer is a compound represented by Structure III: wherein: R 3 is H or -CH 3 ; R 4 is a C 1 -C 6 alkylene; R 5 is H or wherein the dotted line represents the point of attachment to the oxygen atom; and p is from 1 to 5.
  3. The composition of Claim 2 wherein R 3 is -CH 3 , R 4 is -CH 2 CH 2 -, R 5 is H, and p is 1
  4. The composition of any one of the preceding claims wherein the polymer particles comprise at least 2 weight percent to 10 weight percent structural units of the organo-phosphorus monomer relative to the total weight of the polymer particles.
  5. The composition of any one of the preceding claims wherein the polymer particles further comprise at least 30 weight percent to 98 weight percent structural units of acrylate and methacrylate monomers relative to the total weight of the polymer particles.
  6. The composition of any one of the preceding claims wherein: Ar 1 is phenyl-O-CH 2 -or o -methylphenyl-O-CH 2 -; Ar 2 is phenyl, phenyl-OCH 2 CH 2 -, or o -methylphenyl; each R 1 is independently H or CH 3 ; m is from 1 to 10; and n is from 0 to 40.
  7. The composition of any one of the preceding claims wherein the hydrophobic fragment has a number average molecular weight (M n ) in the range of from 500 to 10,000 g/mol; and X is O, or N-CH 3 , N-phenyl, or N-benzyl.
  8. The composition of claim 7 which wherein the hydrophobic fragment has an M n in the range of from 500 to 2500 g/mol and is selected from the group consisting of: where R 1 ' is H or CH 3 ; and R 2 ' is CH 3 or benzyl.
  9. The composition according to any one of the preceding claims comprising an aqueous dispersion of 10 to 60 weight percent, based on the weight of the composition, of the polymer particles; and from 0.05 to 2 weight percent, based on the weight of the composition, of the hydrophobically modified oxyalkylene-urethane polymer.
  10. The composition of any one of the preceding claims which comprises less than 10 PVC of TiO 2 or BaSO 4 particles.
  11. The composition of any one of the preceding claims which further includes one or more materials selected from the group consisting of binders, dispersants, pigments, defoamers, surfactants, solvents, extenders, coalescents, biocides, and opaque polymers.
  12. The composition of any one of the preceding claims, wherein the hydrophobically modified oxyalkylene-urethane polymer is a hydrophobically modified oxyethylene-urethane polymer.

Description

Background of the Invention The present invention relates to rheology modifiers having improved viscosity retention of tinted coatings formulations. US 9,745,492 relates to a composition comprising an aqueous dispersion of an associative thickener having a hydrophobic portion with a calculated log P in the range of from 2.7 to 4.8; and composite particles comprising phosphorus acid functionalized polymer particles adsorbed to the surfaces of TiO2 particles. This provides formulators with flexibility in their use of low and mid shear rate thickeners to balance paint performance properties. Hydrophobically modified alkylene oxide urethane polymers, more particularly hydrophobically modified ethylene oxide urethane polymers (HEURs) are preferred rheology modifiers for paints because of the combination of good flow and levelling and reduced water sensitivity. HEURs build viscosity in aqueous dispersions through associative thickening, and this viscosity is sensitive to the addition of solvents and surfactants which can interfere with the HEUR associative network. HEUR-thickened formulations often lose a substantial amount of viscosity when tinted with colorant dispersions and concentrates, as these colorants are comprised of organic and inorganic pigments, solvents, and surface-active agents which act to disperse and stabilize the pigment particles. When added to a coatings formulation, the colorant will dilute the paint, contribute solvents and surfactants, and cause pre-existing surface-active agents to redistribute throughout the formulation - all of which tend to reduce the viscosity built by HEUR thickeners. Summary of the Invention The present invention addresses a need in the art by providing a composition comprising (i) polymer particles comprising structural units of an organo-phosphorus monomer and (ii) a hydrophobically modified oxyalkylene-urethane polymer having a hydrophobic fragment represented by Structure I: where the dotted line represents the point of attachment of the fragment to the hydrophobically modified oxyalkylene-urethane polymer; Ar1 is unsubstituted phenyl, naphthyl, phenyl-O-CH2-, phenyl-CH2-O-CH2-, or naphthyl-O-CH2-; or phenyl, naphthyl, phenyl-O-CH2-, phenyl-CH2-O-CH2-, or naphthyl-O-CH2- substituted with from 1 to 3 C1-C6 alkyl or alkoxy groups; and Ar2 is phenyl, phenyl-OCH2CH2-, phenyl-(OCH2CH2)y-, benzyl, naphthyl, naphthyl-CH2-, naphthyl-OCH2CH2-or naphthyl-(OCH2CH2)y-, wherein the phenyl or naphthyl portion of Ar2 is unsubstituted or substituted with from 1 to 3 C1-C6 alkyl groups; wherein y is from 2 to 10; each R1 is independently H or C1-C6-alkyl; X is O or NR2, wherein R2 is H, C1-C6-alkyl, phenyl, or benzyl; m is from 1 to 20; and n is from 0 to 100. The compound of the present invention addresses a need in the art by providing viscosity stability upon tinting for paints containing polymer particles comprising structural units of an organo-phosphorus monomer and a hydrophobically modified oxyalkylene-urethane rheology modifier. Detailed Description of the Invention The present invention is a composition comprising (i) polymer particles comprising structural units of an organo-phosphorus monomer and (ii) a hydrophobically modified oxyalkylene-urethane polymer having a hydrophobic fragment represented by Structure I: where the dotted line represents the point of attachment of the fragment to the hydrophobically modified oxyalkylene-urethane polymer; Ar1 is unsubstituted phenyl, naphthyl, phenyl-O-CH2-, phenyl-CH2-O-CH2-, or naphthyl-O-CH2-; or phenyl, naphthyl, phenyl-O-CH2-, phenyl-CH2-O-CH2-, or naphthyl-O-CH2- substituted with from 1 to 3 C1-C6 alkyl or alkoxy groups; and Ar2 is phenyl, phenyl-OCH2CH2-, phenyl-(OCH2CH2)y-, benzyl, naphthyl, naphthyl-CH2-, naphthyl-OCH2CH2-or naphthyl-(OCH2CH2)y-, wherein the phenyl or naphthyl portion of Ar2 is unsubstituted or substituted with from 1 to 3 C1-C6 alkyl groups; wherein y is from 2 to 10; each R1 is independently H or C1-C6-alkyl; X is O or NR2, wherein R2 is H, C1-C6-alkyl, phenyl, or benzyl; m is from 1 to 20; and n is from 0 to 100. As used herein, the term "oxyalkylene-urethane polymer" refers to water-soluble polyethylene oxide polymers, as well as water-soluble polyethylene oxide/polypropylene oxide and polyethylene oxide/polybutylene oxide copolymers. Preferably, the oxyalkylene-urethane polymer is an oxyethylene-urethane polymer. As used herein, a hydrophobically modified oxyalkylene-urethane polymer refers to a polyethylene, polypropylene, or polybutylene oxide urethane polymer, preferably a polyethylene oxide urethane polymer (a HEUR) modified with the hydrophobe fragment of Structure I. The fragment of Structure I is prepared with a capping agent which is a compound represented by Structure II: Examples of suitable diisocyanates include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethyl-1,6-diisocyanatohexane, 1,10-decamethylene diisocyanate, 4,4'-methylenebis(isocyanatoc