Mitsui Chemicals, Inc.

Mitsui Toatsu Chemicals, Incorporated

Other

Hiroshi Suizu

Masanobu Ajioka

Masatoshi Takagi

Yuji Terado

Akihiro Yamaguchi

Shinji Ogawa

Masayuki Sakai

Shoji Hiraoka

Hiroyuki Suzuki

Yasushi Kotaki

Chojiro Higuchi

Taiji Kameoka

Ryo Shinagawa

Teruyuki Nagata

Keisuke Takuma

Hiroshi Kimura

Masayuki Furuya

Masaru Wada

Isamu Ghoda

Takeshi Kashima

Tatsuo Yamazaki

Ikumi Kitada

Haruo Yuasa

Mihaya Matsukawa

Isamu Kawamura

Motoyuki Esaki

Isao Hata

The invention relates to a process for producing an aliphatic polyester excellent in stability which includes subjecting an aliphatic polyester containing at least 50% of an aliphatic hydroxycarboxylic acid unit, obtainable by solid-phase polymerization under a flowing gas in the presence of a volatile catalyst so as to have a desired weight average molecular weight within the range of 50,000 to 1,000,000, to a heat treatment at a temperature equal to or higher than the reaction temperature of the solid-phase polymerization under a flowing gas with maintaining the aliphatic polyester in a solid state. According to the process of the invention, an aliphatic polyester excellent in stability at molding and storage stability is obtained.

Process for producing aliphatic polyester excellent in stability

A process for producing aliphatic polyester wherein a crystallized aliphatic polyester prepolymer formed from an aliphatic dihydric alcohol and an aliphatic dicarboxylic acid and having a weight-average molecular weight of 2,000 to 100,000 is caused to undergo solid-phase polymerization in the presence of a volatile catalyst to make an aliphatic polyester having a weight-average molecular weight of 50,000 to 1,000,000. This process is more efficient than any prior process calling for a complicated step for catalyst removal, since it enables the removal of the catalyst from the reaction system during and/or after solid-phase polymerization. The polyester is comparable in stability to any aliphatic polyester having any catalyst removed therefrom.

Process for preparing aliphatic polyester

A bag for packing powder, permeable for gases and comprising a plurality of inwards protrudent hole-forming portions. Preferably, the bag comprises a film having holes (B) of predetermined thickness (d) furnished with protrudent hole-forming portions of predetermined height (h), the height (h) of the protrudent hole-forming portions being in the range of 2 to 200, still preferably 5 to 100, times the thickness (d) of the film having holes (B). By virtue of this structure, the soaring of powder at the time of powder filling can be prevented to thereby facilitate the filling operation. Furthermore, not only is the sticking of powder to seal portion reduced at the time of sealing the mouth of the bag to thereby ensure obtaining satisfactory seal strength but also the environmental pollution by the soaring of powder can be avoided.

Bag for packing powder, method of producing the same and method of producing film having holes constituting the bag

The invention provides a process for producing high-molecular aliphatic polyesters capable of being substitutes for general-purpose resins that are required to have high toughness, in a simplified manner and at a high volume efficiency. Specifically, in the process, used as the starting material is an easily-available, low-molecular aliphatic polyester prepolymer to be prepared through polycondensation of inexpensive materials of an aliphatic hydroxycarboxylic acid such as lactic acid, glycolic acid or the like, an aliphatic polyalcohol such as butanediol or the like, and an aliphatic polycarboxylic acid such as succinic acid or the like, and the starting prepolymer is crystallized and thereafter polycondensed in a solid phase in the presence of a catalyst to give the intended, tough and high-molecular aliphatic polyester.

Preparation process of polyester

A process for treating pyruvic acid and other impurities of lactic acid by reduction treatment of an aqueous lactic acid solution and for obtaining high quality lactic acid having a substantially no pyruvic acid content, high purity, excellent heat stability and improved smell. Further, a high molecular weight polylactic acid having low coloration and consistent quality can be prepared by dehydration polycondensation of lactic acid obtained by the reduction treatment.

Purification process of lactic acid

A degradable polymer and a process for preparing the degradable polymer which has a structure resulting from combination of a star-shaped polymer comprising a polyfunctional base compound of polycarboxylic acid having three or more carboxyl groups and/or anhydride of the same or aliphatic polyhydric alcohol having three or more hydroxyl groups and a unit of aliphatic hydroxycarboxylic acid, with aliphatic polyhydric alcohol having two or more hydroxyl groups or polycarboxylic acid having two or more carboxyl groups or anhydrides of the same. The degradable polymer leads to remarkably low coloration as compared with a polymer comprising polysaccharide as a polyfunctional base compound, has high melt tension as compared to common aliphatic polyester is excellent in processability on various molding methods, foam molding and blow molding in particular, and high transparency.

Degradable polymer and preparation process of the same

A preparation process of a degradable copolymer comprising carrying out dehydration polycondensation of polysaccharide (A) with one or more compounds (B) selected from the group consisting of:

Preparation of degradable copolymers

The invention is a purification process of an aliphatic polyester prepared in the presence of a catalyst from a hydroxycarboxylic acid or a cyclic ester of a hydroxycarboxylic acid, or a combination of an aliphatic polyhydric alcohol with an aliphatic polybasic acid, or a mixture of these compounds, comprising deactivating the catalyst while maintaining the aliphatic polyester in a molten or dissolved state, or insolubilizing and separating the catalyst and successively removing low molecular compounds; and can provide aliphatic polyester which has a low content of unreacted monomers and low molecular weight compounds and is excellent in heat resistance and weatherability.

Purification process of aliphatic polyester

The invention is a method of dyeing aliphatic polyester filaments with a disperse dye by selecting a dyeing temperature, dyeing pH, and dyeing time in such a way that the weight average molecular weight of the aliphatic polyester filament has a lowering ratio of 20% or less. The invention is a method for dyeing the aliphatic polyester filament with good reproducibility and level dyeing property while substantially maintaining the molecular weight and the essential excellent properties of the aliphatic polyester filament, and can provide dyed articles which have high strength, are excellent in level dyeing property and color fastness to light, and have various hues.

Dyeing method

A purification process of an aliphatic polyester prepared in the presence of a catalyst from a hydroxycarboxylic acid or a cyclic ester of a hydroxycarboxylic acid, or a combination of an aliphatic polyhydric alcohol with an aliphatic polybasic acid, or a mixture of these compounds, comprising deactivating the catalyst while maintaining the aliphatic polyester in a molten or dissolved state, or insolubilizing and separating the catalyst and successively removing low molecular compounds. The process can provide aliphatic polyester which has a low content of unreacted monomers and low molecular weight compounds and is excellent in heat resistance and weatherability.

N-substituted monochlorosuccinimides e.g., N-phenylmonochlorosuccinimide, can be prepared in a high yield by reacting a maleamic acid, e.g., N-phenylmaleamic acid, with phosgene in the presence of a catalyst, e.g., dimethylformamide.

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Kanagawa-ken, Japan

Hiroshi Suizu