Nippon Shokubai Co., Ltd.

Hideki Oishi

Shuji Shimizu

Jiro Iriguchi

Mitsuo Kushino

Yoshikuni Mori

Tadahiro Yoneda

Masafumi Inoue

Yasuhiro Shingai

Yuji Ono

Shoichi Shibazaki

The object of the present invention is to provide silica particles which are surface-treated with a silicon compound uniformly and have improved surface characteristics and affinity with a resin. The silica particles according the present invention are surface-treated with a specific silicon compound, wherein C/Si ratio from X-ray photoelectron spectroscopy (XPS) is not less than 0.05.

Silica particles, resin composition containing said particles, and use thereof

The present invention provides an amino resin composite particle in which an inorganic compound is fixed (firmly adhered) on a surface of an amino resin particle, for example, an amino resin composite particle, in which a child particle made of the inorganic compound is fixed on a mother particle made of the amino resin particle, and a method of easily and inexpensively producing the amino resin composite particle. After an amino compound such as benzoguanamine is reacted with formaldehyde, so as to prepare a reaction mixture containing an amino resin precursor to be the mother particle, an emulsion of the reaction mixture and an aqueous solution of an emulsifier, and an aqueous dispersion of the inorganic compound, such as silica powder, to be the child particle are mixed with a shear force application, so as to emulsify them to have an emulsion thereof. The emulsion is hardened by adding a catalyst. The thus obtained amino resin composite particle has a firm-adhering ratio of the inorganic compound of 10% or more.

Amino resin composite particle and method of producing same

A grain aggregate is formed by bonding a plurality of cross-linking polymeric grains via a substance (binder) having a reactive functional group, and alternatively, the grain aggregate is formed by bonding at least two different types of a plurality of grains, thus providing the grain aggregate having the improved heat resistance, solvent resistance, strength and light-diffusing properties. Further, a light-diffusing agent made up of the grain aggregate has the improved light-diffusing properties. Therefore, when applying a light-diffusing mold article including the light-diffusing agent to, for example, a backlight of a liquid crystal display device, high brightness and a wide angle of visibility can be attained. Further, by spray drying of a dispersion liquid containing the grain aggregate, the grain aggregate can be produced with ease.

Grain aggregate and producing method thereof, and light-diffusing agent

A process for producing amino resin particles includes: a reaction process for obtaining a reaction solution containing an amino resin precursor which is obtained by a reaction of an amino compound with formaldehyde, and having a viscosity in a range of from 2&times;10 Pa&middot;s to 5.8&times;10 Pa&middot;s at a temperature in a range of from 95&deg; C. to 98&deg; C.; an emulsion process for obtaining an emulsion by emulsifying the reaction solution; and a curing process for curing the amino resin precursor in the emulsion state by adding a catalyst to the emulsion. With this producing process, it is possible to readily produce amino resin particles with an essentially uniform particle size (narrow particle size distribution). Further, with use of an aqueous dispersion of an inorganic pigment which is obtained by wet pulverizing the inorganic pigment in an aqueous medium until the average particle size of the inorganic pigment measured by a light scattering method becomes not more than 300 nm, it is possible to obtain amino resin particles with superior properties in coloring strength, visibility, heat resistance, solvent resistance, and chemicals resistance.

Process for producing amino resin particles

Thermosetting resin potting composition

Provided is a silica base particle having an average particle diameter of 0.01 to 10 .mu.m, wherein carboxylic esters are present on the surface of the above particle in a proportion falling in a range of 0.05 to 10% by weight based on the weight of the above particle. A polyester film containing the above silica base particles shows an excellent lubricant property and scratch resistance.

Silica base particles and production process for same

A method for the recovery of microfine suspended particles from a suspension medium, characterized by subjecting a polymeric monomer suspended in a suspension medium to suspension polymerization thereby forming microfine globular particles in the suspension solution, adding microfine water-insoluble particles to said suspension solution of microfine globular particles thereby inducing cohesion of said microfine globular particles, and separating said microfine globular particles in the form of an aggregate from said suspension solution filtration.

Method for production of microfine colored particles and

A method for the production of microfine colored particles, characterized by subjecting a polymeric monomer suspended in a suspension medium to suspension polymerization in the presence of a coloring agent and/or a magnetic powder thereby forming microfine globular colored particles possessing an average particle diameter in the range of from 3 to 50 .mu.m, heat treating said microfine globular colored particles with water as a heating medium at a temperature in the range of from 50.degree. C. to 130.degree. C. thereby inducing fusion of said particles and giving rise to blocks of fused particles, and then disintegrating said blocks of particles to an average particle diameter substantially equal to the average particle diameter of said microfine globular colored particles existent prior to said fusion.

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Himeji, Japan

Hideki Oishi