Organic polymeric particles, paper coating compositions, and methods

A method of making a hollow porous particle, the method comprising:

• (a) providing an organic polymeric particle including a core including a polymer including units deriving from the polymerization of acrylate monomer;
• and a shell surrounding the core, where the shell includes a polymer having units deriving from the polymerization of styrene monomer and acrylate monomer;
• where the shell includes polymer having from 70 to 98 weight units deriving from the polymerization of styrene monomer, and from 2 to 30 weight units deriving from the polymerization of acrylate monomer;
• (b) combining the organic polymeric particle with an alkaline compound to thereby form a hydrolysis mixture;
• and
• (c) heating the hydrolysis mixture to a temperature of at least 140° C. for at least 120 minutes to thereby hydrolyze the units deriving from the polymerization of acrylate monomer within the shell and the core, to thereby provide a hollow porous particle.

A method of preparing a coated paper, the method comprising:

• (a) providing an organic polymeric particle including a core including a polymer including units deriving from the polymerization of acrylate monomer;
• and a shell surrounding the core, where the shell includes a polymer having units deriving from the polymerization of styrene monomer and acrylate monomer;
• where the shell includes polymer having from 70 to 98 weight units deriving from the polymerization of styrene monomer, and from 2 to 30 weight units deriving from the polymerization of acrylate monomer;
• (b) subjecting the organic polymeric particle to conditions that will hydrolyze the units deriving from the polymerization of acrylate monomer within the shell and the core, to thereby provide a hollow porous particle;
• and
• (c) combining the hollow porous particle with a binder and titanium dioxide to thereby form a coating composition.