Aqueous polymer secondary dispersions for manufacturing coatings

摘要

Aqueous secondary dispersion (Q) contains a copolymer (A) obtained from a hydroxyl functional, hydrophobic polymer (I) containing (Ia) (meth)acrylic acid ester with 1-22C hydrocarbon in the alcohol part, vinyl aromatic and/or vinyl ester and (Ib) hydroxyl functional monomer, as a structural monomer, and a hydroxyl functional, hydrophilic polymer (II) containing (IIa) (meth)acrylic acid ester with 1-22C-hydrocarbons in the alcohol part, vinyl aromatic and/or vinyl ester, (IIb) hydroxyl functional monomer and (IIc) acid-functional monomer, as structural components. Aqueous secondary dispersion (Q) contains a copolymer (A) obtained from a hydroxyl functional, hydrophobic polymer (I) containing (Ia) (meth)acrylic acid ester with 1-22C hydrocarbon in the alcohol part, vinyl aromatic and/or vinyl ester and (Ib) hydroxyl functional monomer, as a structural monomer, and a hydroxyl functional, hydrophilic polymer (II) containing (IIa) (meth)acrylic acid ester with 1-22C-hydrocarbons in the alcohol part, vinyl aromatic and/or vinyl ester, (IIb) hydroxyl functional monomer and (IIc) acid-functional monomer, as structural components, where the (meth)acrylic acid ester type (Ia)/(IIa), contains special monomer (B) exhibiting an aliphatic residue with at least eight carbon atoms in the alcohol part and polymer (P) (at least 12.5 wt.%). Independent claims are included for: (1) the preparation of aqueous polyacrylate dispersion comprising: (a) preparing hydroxyl functional, hydrophobic graft base polymer (I) having a hydroxyl number of 12-250 mg potassium hydroxide (KOH)/g of solid material, from (Ia) and (Ib); (b) polymerizing the monomer (IIa)-(IIc) in the solution obtained in (a), where monomer (B) is added in step (a) or (b), and the resulting hydroxyl functional, hydrophilic polymer has hydroxyl number and an acid number of 20-250 mg KOH/g and 50-250 mg KOH/g of solid material, respectively; (c) radical initiated copolymerization of the monomers (I) and (II) in cosolvent; (d) adding neutralizing agent to remove excess ionic group, after the copolymer production; (e) dispersing the copolymer by adding water; and (f) converting copolymer into aqueous form; and (2) a two-component coating agent containing polyacrylate dispersion and cross linker.