Nippon Shokubai Co., Ltd.

Jiro Iriguchi

Yasuhiro Yamamoto

Shuji Shimizu

Hideki Oishi

Tomoyuki Kuwamoto

Tatsuhito Matsuda

Junichi Chosa

Yuji Ono

Masafumi Inoue

Provided are amorphous silica particles for application to industrial fields where there are increasing desires for high purity and colorlessness. The amorphous silica particles are produced through the steps of hydrolysis of an alkoxide, vacuum drying, and firing. The amorphous silica particles have been reduced in coloration and in Fe content, which is causative of coloration of the silica, and can meet the desires. The amorphous silica is characterized by having an Fe content of 20 ppm or less.

Amorphous silica and process for 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

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 process for preparing an aqueous resin dispersion includes the steps of copolymerizing a polymeric monomer whose ratio of (meth) acrolein to a total amount of the (meth) acrolein and a vinyl monomer is in the range from 10 weight % to 80 weight % in an organic solvent to obtain a copolymer solution, dispersing the obtained copolymer solution in an aqueous medium and removing an unreacted (meth) acrolein. Since the above process can extremely reduce contents of the unreacted (meth) acrolein and of an oligomer whose number-average molecular weight is less than 1000, an aqueous resin dispersion where problems of a pungent smell, toxicological properties, etc. due to the (meth) acrolein and the oligomer are eliminated can be provided.

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Himeji, Japan

Jiro Iriguchi