Curable Resin Composition for Optical Fiber Coating
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Solution Overview
Problem
The manufacturing process of optical fibers faces challenges with high attaching force and non-uniform coating due to the differences in rheological properties between primary and secondary resin compositions, leading to processability issues and coating uniformity problems, especially at high speeds.
Innovation Solution
A curable liquid resin composition comprising urethane(meth)acrylates with different molecular weights, specifically a combination of components with molecular weights between 800 g/mol and 20,000 g/mol, is used to create a secondary coating with low attaching force and low coefficient of friction, enhancing processability and coating uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a secondary resin composition is applied to an optical glass fiber simultaneously with a primary resin composition (wet-on-wet application), then both resin compositions are simultaneously cured, but processability instabilities occur due to different rheological properties causing drag flow at high shear rates
Solution Approach 1:
The patent modifies the rheological parameters of the secondary resin composition by adjusting its viscosity and shear-thinning characteristics to be compatible with the primary resin composition. This allows both compositions to flow uniformly under high shear rates during wet-on-wet coating at high drawing speeds, eliminating processability instabilities while maintaining high productivity
Solution Approach 2:
The invention creates a composite coating system where the secondary resin composition is specifically formulated to work in conjunction with the primary resin composition. The composite material approach ensures that both layers exhibit compatible rheological behavior, allowing them to be applied and cured simultaneously without causing drag flow or coating defects, thus enabling both high speed production and ease of operation
2Productivity
If high fiber speed, small clearance between fiber and die, and pressure exerted on the composition are used, then coating application is efficient, but coating uniformity decreases at speeds above 25 m/sec
Solution Approach 1:
The patent adjusts the rheological parameters of the resin composition, specifically optimizing viscosity and shear-thinning behavior, to maintain coating uniformity at high drawing speeds. The modified composition flows more uniformly under the high shear rates and pressures encountered at speeds above 25 m/sec, preventing the coating defects that would otherwise occur
Solution Approach 2:
The invention utilizes the dynamic rheological properties of the resin composition, making it shear-thinning to adapt to the varying shear rates experienced during high-speed coating. This dynamic behavior allows the composition to flow easily under high shear conditions while maintaining uniformity, enabling both high productivity and manufacturing precision
3Strength
If cured secondary material and ribbon matrix material are used as outermost layer, then protective function is provided, but attaching force becomes strong causing difficulty in winding and handling
Solution Approach 1:
The patent applies a surfactant to the outer surface of the cured secondary coating to create a localized low-friction layer. This local quality modification reduces the coefficient of friction and attaching force at the surface, allowing easy handling and winding while the bulk of the cured material maintains its protective strength and rigidity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition achieves a transparent cured surface with improved processability and coating uniformity, reducing the risk of signal attenuation and enhancing the handling of optical fibers during production.
Implementation Method 1
a curable liquid resin composition comprising (A) a urethane(meth)acrylate having a structure originating from a polyol and a number average molecular weight of 800 g/mol or more, but less than 6000 g/mol and (B) a urethane(meth)acrylate having a structure originating from a polyol and a number average molecular weight of 6000 g/mol or more, but less than 20000 g/mol
Data Source
AI summary
The invention relates to a curable liquid resin composition comprising: (A) a urethane(meth)acrylate having a structure originating from a polyol and a number average molecular weight of 800 g/mol or more, but less than 6,000 g/mol, and (B) a urethane(meth)acrylate having a structure originating from a polyol and a number average molecular weight of 6,000 g/mol or more, but less than 20,000 g/mol, wherein the total amount of the component (A) and component (B) is 20-95 wt % of the curable liquid resin composition and the content of the component (B) is 0.1-30 wt % of the total of the component (A) and component (B).