Daicel Corporation

Daicel Chemical Industries, Ltd.

Keio University

Akihiro Higuchi

Masaaki Kusumoto

Hiroki Taniguchi

Hiroyuki Matsumura

Tomohiro Hashizume

Takafumi Kawasaki

Ikuhiro Suzuki

Yuya Ashida

Shu Shimamoto

Kazuo Tsubota

Kyokutou Ga

Takehiro Matsumoto

Kiyoshi Fukuhara

Maiko Tsuda

Naohiro Oyamada

Yukiko Matsuo

The cellulose acetate resin composition may include: a cellulose acetate having a total degree of acetyl substitution of 1.9 or greater and 2.6 or less; and a plasticizer. The cellulose acetate may have a number average molecular weight of 45000 or greater and a weight average molecular weight of 70000 or greater. The plasticizer may be selected from (1) an ether-based plasticizer in which at least one terminal hydroxyl group of a polyalkylene glycol is etherified, and (2) an ester-based plasticizer in which at least one terminal hydroxyl group of a polyalkylene glycol is esterified. The polyalkylene glycol in the ether-based plasticizer (1) and the ester-based plasticizer (2) may have a degree of polymerization of 3 or greater and less than 10. The plasticizer may not include an aromatic ring in the terminal group.

Cellulose acetate resin composition

This cellulose acetate has a total degree of acetyl substitution of 1.75 or more and 2.55 or less, and a degree of acetyl substitution at 2-position or a degree of acetyl substitution at 3-position is 0.7 or less. This cellulose acetate composition includes the cellulose acetate and an additive. The additive is one or more selected from the group consisting of (a) substances of which a pH of a 1 wt. % aqueous solution at 20° C. is 8 or more, (b) substances that dissolve in water at 20° C. in an amount of 2 wt. % or more, and (c) substances that exhibit biodegradability in seawater.

Cellulose acetate and cellulose acetate composition

A cellulose acetate resin composition may include a cellulose acetate (A) having a total degree of acetyl substitution of 2.60 or less; a filler (B); and a plasticizer (C). The filler (B) may be selected from the group consisting of (b1) a predetermined inorganic compound, (b2) a predetermined metal salt, (b3) cellulose or hemicellulose, and (b4) wood flour. The plasticizer (C) may be selected from (c1) a glycerin ester-based plasticizer, (c2) an ether-based plasticizer, and (c3) a glycol ester-based plasticizer. A content of the component (A) may be from 4.5 to 90 mass %. A total content of the component (B) may be from 5 to 50 mass %. A total content of the component (C) may be from 5 to 35 mass %.

The purpose of the present invention is to provide a cellulose acetate excellent in transparency, and a molded article of the cellulose acetate. In the cellulose acetate, an acetylation degree is 52% or more and 59% or less, and a content of low-molecular-weight components having a molecular weight of not more than &#xbc; of a peak top molecular weight in a molecular weight distribution measured by gel permeation chromatography of cellulose acetate is 12% or less.

Cellulose acetate and molded article

This cellulose acetate has a total degree of acetyl substitution of 1.75 or more and 2.55 or less, and a degree of acetyl substitution at 2-position or a degree of acetyl substitution at 3-position is 0.7 or less. This cellulose acetate composition includes the cellulose acetate and an additive. The additive is one or more selected from the group consisting of (a) substances of which a pH of a 1 wt. % aqueous solution at 20&#xb0; C. is 8 or more, (b) substances that dissolve in water at 20&#xb0; C. in an amount of 2 wt. % or more, and (c) substances that exhibit biodegradability in seawater.

The purpose of the present invention is to provide cellulose acetate with which it is possible to obtain a molded article containing cellulose acetate having a small amount of lumps. The cellulose acetate has an acetylation degree of 52% or more and 59% or less, and an acetone-insoluble substance content of 0.04 wt % or less.

Cellulose acetate, cellulose acetate composition, molded article, and film

Provided is cellulose acetate with which a hollow fiber membrane having excellent salt rejection and water permeability can be produced. The cellulose acetate, in which a total content of calcium and magnesium is 2.8 to 3.5 &#x3bc;mol/g; a 6 percent viscosity is 40 to 80 mPa&#xb7;s; a degree of filtration Kw is 35 gor less; a molecular weight distribution Mw/Mn is 3.00 or less; and a degree of acetylation is 61.3 to 62.3%.

Cellulose acetate and method for producing cellulose acetate

The purpose of the present invention is to provide a cellulose acetate which can be used to obtain an optical film having a very small amount of bright spot foreign matters, with excellent production efficiency, even when cellulose containing a small amount of hemicellulose components and having a high degree of crystallinity is used as a raw material. A cellulose acetate in which a content ratio by mole of mannose units to a sum of xylose units, mannose units and glucose units, which are sugar chain components, is 0.04 mol % or less, and a filtration index K measured by the following measurement method is 30 mLor less. (Measurement method) The cellulose acetate is dissolved in a mixed solvent containing methylene chloride and methanol at a weight ratio of methylene chloride/methanol of 9/1 to obtain a solution with a solid concentration of 16% by weight. The temperature of the solution is adjusted to 25&#xb0; C., and the solution is subjected to constant-pressure filtration under a pressure of 3 kg/cmusing a cloth obtained by stacking three sheets of calico (s 618) (diameter: 15 mm, filtration area: 1.77 cm). At this time, the filtration index k (mL) is calculated from the following expression, where Prepresents the amount of filtration (mL) up to 20 minutes after the start of filtration, and Prepresents the amount of filtration (mL) from 0 to 60 minutes. 

Cellulose acetate and producing method therefor

Provided is a cellulose acetate powder that makes it possible to reduce the formation of spotty patches on a formed article of the cellulose acetate and prevent lowering of the production process passability of the formed article. A cellulose acetate powder includes cellulose acetate having an acetylation degree of 53 to 56% and a 6% viscosity of 30 to 200 mPa&#xb7;s. In the cellulose acetate powder, a cumulative pore volume is not less than 0.200 ml/g; a proportion of particles having a particle diameter of not less than 500 &#x3bc;m is not higher than 40%; and an angle of repose is not greater than 51&#xb0;.

Cellulose acetate powder and method of producing cellulose acetate powder

A pharmaceutical composition for prophylaxis and/or treatment of a corneal and conjunctival disease or presbyopia, the composition containing a compound represented by Formula (I), or a salt thereof or a prodrug thereof as an active ingredient, wherein m and n are each independently an integer of 0 to 5; m+n&#x2265;1; and each aromatic ring of the compound represented by Formula (I) may be substituted.

Pharmaceutical composition for prophylaxis and/or treatment of corneal and conjunctival diseases or presbyopia containing stilbene compound as active ingredient

Disclosed is a cellulose diacetate comprising a 6-position highly acetylated cellulose diacetate having a 6-percent viscosity of 40 to 600 mPa&#xb7;s, and having a total degree of acetyl substitution of DSt and a degree of acetyl substitution at the 6-position of DS6, wherein DSt and DS6 satisfy following Conditions (1) and (2):2.0&#x2266;DSt&#x3c;2.6&#x2003;&#x2003;(1)0.400&#x2267;(6/)&#x2267;0.531&#x2212;0.088&#xd7;&#x2003;&#x2003;(2) The cellulose diacetate is usable typically as a starting material for cellulose acylates of different acyl groups, which have a high total degree of acyl substitution, have superior optical properties, and usable typically as photographic materials and optical materials.

6-position highly acetylated cellulose diacetate and process for producing the same

Cellulose ester and film thereof useful for remarkably improving optical properties, e.g., optical isotropy. The cellulose ester has a degree of substitution from 2.90 to 2.965, a total of degrees of substitution at 2- and 3-positions &#x2267;1.97, and a half height width of chemical composition expressed in degree of substitution of &#x2267;0.09. The cellulose ester maybe produced by (i) acylating a cellulose with an acylating agent in the presence of a sulfuric acid catalyst, and (ii) hydrolyzing the acylated product in the presence of a sulfuric acid catalyst, wherein the acylation carried out with 1.40 to 2.0 molar equivalents of the acylating agent relative to 1 mol of a hydroxyl group in the cellulose in the presence of 6.5 to 9.5 parts by weight of the sulfuric acid catalyst relative to 100 parts by weight of the cellulose in the acylating step (i).

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Himeji, Japan

Akihiro Higuchi