Organic-inorganic composite particles
An object of the present invention is to improve the water dispersibility of the PVA-based resin and also to suppress the swelling of the PVA-based resin. The object is achieved by organic-inorganic composite particles, which have an average particle size of preferably 1 μm to 3,000 μm, including a polyvinyl alcohol-based resin and a component having a three-dimensional siloxane crosslinked structure that is derived from a hydrolysis-polycondensation product of an alkoxysilane and/or a low condensate thereof, wherein the alkoxysilane includes a T unit and/or a Q unit as a structural unit (s), and a Si content with respect to a total weight of the composite particles is 0.1 wt % or more and 23 wt % or less in terms of SiO 2 .
1. An organic-inorganic composite particle comprising a polyvinyl alcohol-based resin and a component having a three-dimensional siloxane crosslinked structure that is derived from a hydrolysis-polycondensation product of an alkoxysilane and/or a low condensate thereof,
wherein the alkoxysilane comprises a T unit and/or a Q unit as a structural unit(s), and
a silicon content with respect to a total weight of the composite particles is 0.1 wt % or more and 23 wt % or less in terms of SiO 2 ,
wherein the polyvinyl alcohol-based resin and the component having a three-dimensional siloxane crosslinked structure are arranged as a particle.
2. The organic-inorganic composite particle according to claim 1 ,
wherein the organic-inorganic composite particle has a structure in which the polyvinyl alcohol-based resin is coated with a SiO 2 layer comprising the three-dimensional siloxane crosslinked structure.
3. The organic-inorganic composite particle according to claim 1 ,
wherein the organic-inorganic composite particle has a structure in which the polyvinyl alcohol-based resin is coated with a hybrid film that comprises the component having the three-dimensional siloxane crosslinked structure and a water-soluble resin.
4. The organic-inorganic composite particle according to claim 3 ,
wherein the hybrid film has a silicon content of 15 wt % or more and less than 100 wt % in terms of SiO 2 .
5. The organic-inorganic composite particle according to claim 2 ,
wherein the component having the three-dimensional siloxane crosslinked structure exists in the vicinity of the surface of the polyvinyl alcohol-based resin.
6. The organic-inorganic composite particle according to claim 3 ,
wherein the component having the three-dimensional siloxane crosslinked structure exists in the vicinity of the surface of the polyvinyl alcohol-based resin.
7. The organic-inorganic composite particle according to claim 1 ,
wherein the component having the three-dimensional siloxane crosslinked structure uniformly exists inside the polyvinyl alcohol-based resin.
8. The organic-inorganic composite particle according to claim 1 ,
wherein the polyvinyl alcohol-based resin is a nonionic group-containing polyvinyl alcohol-based resin.
9. The organic-inorganic composite particle according to claim 1 ,
wherein the composite particles have a Si—O—C structure that is derived from a reaction between a hydroxy group of the polyvinyl alcohol-based resin and a hydroxy group of the hydrolysis-polycondensation product of the alkoxysilane and/or low condensate thereof.
10. A diverting agent comprising organic-inorganic composite particles according to claim 1 .
11. A lost circulation material comprising organic-inorganic composite particles according to claim 1 .
12. A fracture plugging method comprising a step of filling some of fractures formed in a well wall with the diverting agent according to claim 10 .
13. A method of preventing lost circulation of drilling mud,
wherein the method comprises a step of filling some of fractures formed in a well wall with the lost circulation material according to claim 11 .
14. The organic-inorganic composite particle according to claim 1 ,
wherein the organic-inorganic composite particle has the average particle size (d50) of 1 μm to 3,000 μm.
15. The organic-inorganic composite particle according to claim 1 ,
wherein the organic-inorganic composite particle is a powder or a pellet; the powder having a granular shape or a pearl shape; and the pellet having a cylindrical shape or a spherical shape.