UV-Curable Aqueous Mold Release for Processable Polyurethane Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mold release agents for polyurethane articles face challenges in providing easy removal from molds without causing damage while also ensuring a surface suitable for further processing, with solvent-based agents posing environmental hazards and water-based agents leaving a smeary surface that hinders adhesion of coatings or adhesives.
Innovation Solution
A mold release agent comprising an aqueous carrier, unsaturated polymer, and Norrish type 1 or 2 photoinitiator, which is cured with actinic radiation to transform the surface from smeary to waxy or solid, facilitating easy removal and enabling further processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If solvent-based release agents are used, then the molded article surface is dry and ready for further processing, but volatile organic solvent emissions occur
Solution Approach 1:
The patent changes the physical-chemical parameters of the release agent by using water instead of volatile organic solvents as the carrier, and by incorporating photoinitiators that enable UV-curable polymers to form dry, processable surfaces after curing, thus eliminating emissions while maintaining surface quality
Solution Approach 2:
The patent replaces the evaporation-based drying mechanism of solvent-based agents with a UV photopolymerization mechanism, where photoinitiators absorb UV radiation to trigger polymerization of unsaturated polymers, forming a solid, dry surface without requiring solvent evaporation
2Object-generated harmful factors
If water-based release agents with waxes are used, then the surface is dry, but the agent adheres to the mold making removal difficult
Solution Approach 1:
The patent changes the molecular structure and adhesion properties of the release agent by using unsaturated polymers with specific glass transition temperatures and molecular weights, combined with photoinitiators, to achieve low mold adhesion while maintaining easy removability after curing
Solution Approach 2:
The patent applies the release agent to the mold before molding, allowing it to form a preliminary protective layer that prevents strong adhesion between the polyurethane and mold surface, facilitating easy removal after the molding process
3Ease of operation
If water-based release agents with polybutadiene or polyisoprene are used, then article removal is easy, but the surface is smeary and wet making further processing difficult
Solution Approach 1:
The patent replaces the simple water evaporation mechanism with UV photopolymerization, where photoinitiators trigger cross-linking of unsaturated polymer chains upon UV exposure, transforming the surface from a smeary wet state to a dry, solid, and processable state
Solution Approach 2:
The patent creates a composite release agent system combining unsaturated polymers (polybutadiene, polyisoprene, or their copolymers) with Norrish type 1 or 2 photoinitiators, where the polymer provides release properties and the photoinitiator enables UV-curable surface formation
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 agent allows easy demolding without damage and provides a surface ready for further processing, such as adhesive application, by converting the surface from smeary to dry and waxy through UV curing.
Implementation Method 1
a step of irradiating at least a part of the surface of the article with UV radiation
Implementation Method 2
water-based release agents use water as the carrier
Data Source
AI summary
The present invention is related to an aqueous mold release agent for the production of polyurethane articles, particularly molded polyurethane foam articles, comprising an unsaturated polymer and a Norrish-type 1 and or a Norrish-type 2 photoinitiator, characterized in that the unsaturated polymer comprises a polybutadiene, a polyisoprene, a copolymer of butadiene and isoprene, or a combination thereof. The present invention is further directed to a process of producing a molded polyurethane article, comprising applying said aqueous agent to a mold, and to the use said aqueous mold release agent for the production of molded polyurethane articles