Provided are a method for producing organic material microparticles and a method for modifying organic material microparticles, whereby it becomes possible to improve the crystallinity of organic material microparticles or achieve the crystal transformation of the organic material microparticles while preventing the growth of the organic material microparticles in a solvent. A surfactant is added to a solvent that is capable of partially dissolving organic material microparticles, and then the organic material microparticles are reacted with the solvent. In this manner, it becomes possible to improve the degree of crystallization of the organic material microparticles or achieve the crystal transformation of the organic material microparticles without substantially altering the particle diameters of the organic material microparticles.

A high-hydrophobic, low-bleeding color lake powder, a method for preparing the sane and a use thereof are provided. A color lake powder is dispersed into water, and a pH value of a system is adjusted to a range of 4 to 5.5. Then surface treating agents such as a silane coupling agent, a titanate coupling agent, a hydrogenated lecithin and an aliphatic acid are used to modify the color lake powder. Then pulverizing and drying the resultant to obtain the modified color lake powder.

Provided are a method for producing organic material microparticles and a method for modifying organic material microparticles, whereby it becomes possible to improve the crystallinity of organic material microparticles or achieve the crystal transformation of the organic material microparticles while preventing the growth of the organic material microparticles in a solvent. A surfactant is added to a solvent that is capable of partially dissolving organic material microparticles, and then the organic material microparticles are reacted with the solvent. In this manner, it becomes possible to improve the degree of crystallization of the organic material microparticles or achieve the crystal transformation of the organic material microparticles without substantially altering the particle diameters of the organic material microparticles.

The present invention is directed to a particle-containing entity P-(A--B-M).sub.x wherein P is a solid particle attached to at least one polymer M through one or several reversible covalent bonds -A---B-, wherein A and B are functional groups respectively grafted to P and M thus forming the P-(A---B-M).sub.x particle-containing entity with x being greater than or equal to 1, M has a degree of polymerization comprised between 5 and 1000, preferably ranging from 5 to 500, and wherein the reversible covalent bond -A---B- is chosen among an imine, a disulfide, a boronic ester or an acetal. The invention is also directed to a method of preparing this particle-containing entity, a method for sequentially forming and breaking the reversible covalent bond -A---B- in said particle-containing entity P-(A---B-M).sub.x and dispersions comprising same.

Provided are a method for producing organic material microparticles and a method for modifying organic material microparticles, whereby it becomes possible to improve the crystallinity of organic material microparticles or achieve the crystal transformation of the organic material microparticles while preventing the growth of the organic material microparticles in a solvent. A surfactant is added to a solvent that is capable of partially dissolving organic material microparticles, and then the organic material microparticles are reacted with the solvent. In this manner, it becomes possible to improve the degree of crystallization of the organic material microparticles or achieve the crystal transformation of the organic material microparticles without substantially altering the particle diameters of the organic material microparticles.