Polyurethane Urea Resin Sunscreen Tolerance
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Solution Overview
Problem
Synthetic resin skin materials swell and deteriorate when exposed to sunscreen agents containing high concentrations of ultraviolet absorbing agents, due to the affinity between the ultraviolet absorbing agents and the urethane resin used in these materials, leading to undesirable infiltration and loosening of urethane bonds.
Innovation Solution
The use of a polyurethane urea resin with a specific molecular weight range (35,000 to 100,000) in both the skin and adhesive layers, obtained by reacting a polyol, a polyisocyanate, a diamine, and a monoamine, which includes a polycarbonate polyol with a divalent aliphatic or alicyclic hydrocarbon group, and an alicyclic diisocyanate, to enhance sunscreen agent tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional urethane resin is used in synthetic resin skin material, then texture and mechanical strength are improved, but the material swells and deteriorates when exposed to sunscreen agents containing ultraviolet absorbing agents
Solution Approach 1:
The patent changes the chemical parameters of the urethane resin by specifying a number average molecular weight range of 35,000 to 100,000 and using specific raw materials (polycarbonate polyol with divalent aliphatic or alicyclic hydrocarbon group, alicyclic diisocyanate). These parameter changes reduce the affinity between the resin and ultraviolet absorbing agents, preventing swelling while maintaining mechanical strength.
Solution Approach 2:
The patent creates a composite resin system by combining specifically selected polyol, polyisocyanate, diamine, and monoamine components. This composite approach produces a urethane resin with optimized molecular structure that resists ultraviolet absorbing agents while maintaining desirable texture and mechanical properties.
2Object-affected harmful factors
If ultraviolet absorbing agent is applied in high concentration for sunscreen protection, then ultraviolet blocking ability is improved, but infiltration into the synthetic resin skin material increases causing swelling
Solution Approach 1:
The patent applies preliminary anti-action by pre-modifying the urethane resin structure before exposure to sunscreen agents. The resin is designed with specific molecular weight and chemical composition that creates resistance against ultraviolet absorbing agent infiltration, preventing swelling and structural deterioration before contact occurs.
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
This approach inhibits outer appearance deterioration and provides excellent sunscreen agent tolerance, preventing swelling and maintaining the integrity of the synthetic resin skin material even when exposed to sunscreen agents with ultraviolet absorbing agents.
Implementation Method 1
the skin and adhesive layers including a polyurethane urea resin obtained by reacting a polyol, a polyisocyanate, a diamine, and a monoamine
Implementation Method 2
there are cases in which undesirable infiltration of an ultraviolet absorbing agent from a surface of a synthetic resin skin material to an inner part of the synthetic resin skin material occurs
Data Source
AI summary
A synthetic resin skin material includes, on one side of a base material 12, an adhesive layer 14, a skin layer 16, and a surface processing layer 18 in this order from the base material 12, the adhesive layer 14 and the skin layer 16 containing a polyurethane urea resin having a number average molecular weight of from 35,000 to 100,000.