EP0874012A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Coating composition for optical fiber

Assignee: Shin-Etsu Chemical Co Ltd

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Filing: 1998-04-22

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Granted: —

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Expires: 2018-04-22

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Abstract

Abstract In the coating composition for a optical fiber of the present invention, a polyurethane (meth)acrylate oligomer (A), which is based on a urethane prepolymer having an equivalent ratio of NCO group in a polyisocyanate (a) to OH group in a polyol (b) of more than 3.0, is used and the oligomer (A) has a mixing weight ratio of an oligomer (d) having a number average molecular weight of 800 or less to an oligomer (e) having a number average molecular weight of 1,000 or more of 30/70 - 70/30. The coating composition of this invention has a low viscosity, and therefore, is suitable for a rapid fiber-drawing in a production of an optical fiber. Further, a cured material obtained from the coating composition of the present invention has both a high elastic modulus and a high elongation, which properties are required for a hard material, and has a slight change of elastic modulus with a change of temperature to improve a long-term reliability of an optical fiber.

Inventors

👤 Kyuya c/o Takeda Chemical Ind. Ltd Yamazaki
👤 Mitsuhiro c/o Takeda Chem. Ind. Ltd. Nishimura
👤 Takashi c/o Takeda Chemical Ind. Ltd. Uemura
👤 Akira c/o Shin-Etsu Chem. Co. Ltd Yamamoto
👤 Shouhei c/o Shin-Etsu Chemical Co. Ltd Kozakai
👤 Masatoshi c/o Shin-Etsu Chemical Co. Ltd Asano

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-10-31 21:17

CPC Classifications

C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/67; C08G18/671; C08G18/672; C03; C03C; C03C25/00; C03C25/10; C03C25/104; C03C25/106; C08F; C08F290/00; C08F290/08; C08F290/14; C08F290/147; C08G18/08; C08G18/10; C08G18/65; C08G18/66; C08G18/6666; C08G18/667; C08G18/6674; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2938

Claims Analysis

Total Claims: 4

Claim 1

Independent Claim 119 words

A coating composition for an optical fiber which comprises: (A) a polyurethane (meth)acrylate oligomer which is obtainable by subjecting (a) a polyisocyanate, (b) a polyol and (c) a (meth)acrylate monomer containing a hydroxyl group to a urethanation reaction; (B) an ethylenically unsaturated compound; and (C) a photopolymerization initiator, wherein said urethanation reaction is conducted under conditions that an equivalen ratio of NCO group in (a) to OH group in (b) is more than 3.0, and that a ratio of a remaining equivalent of NCO group calculated by subtracting the equivalent of OH group in (b) from the equivalent of NCO group in (a) to an equivalent of OH group in (c) is within a range of 0.9 - 1.1.

Claim 2

Dependent Claim 72 words

The coating composition for an optical fiber according to claim 1, wherein, in (A), a proportion of the total amount of (d) a component with a number average molecular weight of 800 or less and (e) a component with a number average molecular weight of 1,000 or more to the total amount of (A) is 30% by weight or more, and a weight ratio of (d) to (e) is 30/70 - 70/30.

Claim 3

Dependent Claim 25 words

The coating composition for an optical fiber according to claim 1, wherein, in (A), a weight ratio of (d) to (e) is 51/49 - 70/30.

Claim 4

Dependent Claim 36 words

The coating composition for an optical fiber according to claim 1, wherein, in (A), a proportion of the total amount of (d) and (e) to the total amount of (A) is 40% by weight or more.

References Cited (Backward Citations)

DE3437531A1 Cited

GB2163443A Cited

WO1991003499A1 Cited

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