Processes for producing aqueous alkyd resin dispersions

A process for producing an aqueous alkyd resin dispersion, which is characterized by comprising:

• (A-2) a step of synthesizing an alkyd resin having a hydroxyl value of 0.1-50 mgKOH/g by depolymerizing polyester resin whose chief starting material is terephthalic acid and which has been recovered from waste materials and regenerated, while carrying out its esterification at the same time, by dissolving the polyester resin in a mixture of an alcoholic component in which the weight ratio of tri- or lower polyhydric alcohol to tetra- or higher hydric alcohol as the former/latter is within a range of 0-20, a fatty acid and/or an oil and fat, and polybasic acid component,
• (B-2) a step for obtaining a maleinized alkyd resin having an acid value of 10-200 mgKOH/g by reacting the alkyd resin as obtained in the above step (A-2) with maleic anhydride, and
• (C-2) a step of neutralizing and dispersing in water the maleinized alkyd resin as obtained in the above step (B-2).

A process for producing an aqueous alkyd resin dispersion, which is characterized by comprising:

• (A-3) a step of synthesizing an alkyd resin having a hydroxyl value of 5-200 mgKOH/g by depolymerizing polyester resin whose chief starting material is terephthalic acid and which has been recovered from waste materials and regenerated, and carrying out its esterification at the same time, by dissolving the polyester resin in a mixture of an alcoholic component in which the weight ratio of tri- or lower polyhydric alcohol to tetra- or higher hydric alcohol as the former/latter is within a range of 0-20, a fatty acid and/or an oil and fat, and polybasic acid component,
• (B-3) a step for obtaining a modified alkyd resin having an acid value of 10-200 mgKOH/g by reacting the alkyd resin as obtained in the above step (A-3) with an acid anhydride having no ethylenically unsaturated radical, and
• (C-3) a step of neutralizing and dispersing in water the modified alkyd resin as obtained in the above step (B-3).

A process for producing an aqueous alkyd resin dispersion, which is characterized by comprising:

• (A-4) a step of synthesizing an alkyd resin having an acid value of 10-200 mgKOH/g by depolymerizing polyester resin whose chief starting material is terephthalic acid and which has been recovered from waste materials and regenerated, while carrying out its esterification at the same time, by dissolving the polyester resin in a mixture of an alcoholic component in which the weight ratio of tri- or lower polyhydric alcohol to tetra- or higher hydric alcohol as the former/latter is within a range of 0-20, a fatty acid and/or an oil and fat, and polybasic acid component, and
• (C-4) a step of neutralizing and dispersing in water the alkyd resin as obtained in the above step (A-4).