Polyvinyl Acetal Composition Transparency Recycling
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Solution Overview
Problem
Recycled off-spec polyvinyl acetal compositions for laminated sound insulation interlayer films often result in opaque or poorly transparent interlayer films due to compatibility issues between polyvinyl acetals with different average amounts of remaining hydroxyl groups, particularly when triethylene glycol di(2-ethylhexanoate) is used as a plasticizer.
Innovation Solution
A polyvinyl acetal composition comprising specific ratios of polyvinyl acetals with different average amounts of remaining hydroxyl groups, combined with a polyester, polyalkylene oxide, or ester compound containing hydroxyl groups, to enhance compatibility and transparency, including the use of triethylene glycol di(2-ethylhexanoate) as a plasticizer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If polyvinyl acetal compositions with different average amounts of remaining hydroxyl groups are mixed for recycling trim or off-spec products, then productivity is improved by recycling materials, but transparency deteriorates due to poor compatibility between different polyvinyl acetals
Solution Approach 1:
A compatibility control agent is introduced as an intermediary substance to mediate between polyvinyl acetals with different hydroxyl group contents. The compatibility control agent contains functional groups that can interact with both types of polyvinyl acetal, acting as a bridge to improve mutual solubility and prevent phase separation, thereby maintaining transparency while enabling recycling of mixed compositions
Solution Approach 2:
The chemical composition parameters of the polyvinyl acetal system are modified by adding the compatibility control agent. This changes the interaction parameters between different polyvinyl acetals, adjusting the hydrophilicity-hydrophobicity balance and enabling compatible mixing of materials with different hydroxyl group contents without compromising transparency
2Reliability
If triethylene glycol di(2-ethylhexanoate) is used as a plasticizer to achieve low water absorbency and high boiling point, then water resistance is improved, but transparency deteriorates when recycling mixed polyvinyl acetal compositions
Solution Approach 1:
The compatibility control agent serves as a mediator between the triethylene glycol di(2-ethylhexanoate) plasticizer and the polyvinyl acetals. It facilitates compatible mixing by providing interaction sites that bridge the plasticizer and polymer chains, preventing phase separation and maintaining transparency while preserving the water resistance benefits of the plasticizer
Solution Approach 2:
The system is formulated as a composite material system comprising polyvinyl acetals, triethylene glycol di(2-ethylhexanoate) plasticizer, and compatibility control agent. The compatibility control agent enables the composite to maintain homogeneity and transparency by ensuring compatible interaction between all components, particularly when recycling mixed compositions
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 excellent transparency and compatibility, even when using off-spec materials, by optimizing the ratio of polyvinyl acetals and adding specific compounds, thereby improving the mechanical strength and water resistance of the interlayer films.
Implementation Method 1
the polyvinyl acetal composition comprises 3 to 100 parts by mass of polyvinyl acetal (B) with respect to 100 parts by mass of polyvinyl acetal (A), and 0.05 to 0.75 times by mass of compound (C) with respect to the total mass of polyvinyl acetal (A) and polyvinyl acetal (B)... |X−Y|≥3 is satisfied
Implementation Method 2
Triethylene glycol di(2-ethylhexanoate) has low polarity and a high boiling point. A composition obtained by mixing triethylene glycol di(2-ethylhexanoate) with a polyvinyl acetal... exhibit, in a well-balanced manner, properties required for an interlayer film for laminated glass
Data Source
AI summary
An object is to provide a polyvinyl acetal composition which includes polyvinyl acetals having different average amounts of remaining hydroxyl groups and from which a sheet having excellent transparency can be molded.A polyvinyl acetal composition comprising 3 to 100 parts by mass of polyvinyl acetal (B) with respect to 100 parts by mass of polyvinyl acetal (A), and 0.05 to 0.75 times by mass of compound (C) with respect to the total mass of polyvinyl acetal (A) and polyvinyl acetal (B). The polyvinyl acetal (A) has an average amount of remaining hydroxyl groups of X mol % (X is a positive number), the polyvinyl acetal (B) has an average amount of remaining hydroxyl groups of Y mol % (Y is a positive number), and |X−Y|≥3 is satisfied. The compound (C) is selected from a group consisting of a polyester containing a hydroxyl group, a polyalkylene oxide, and an ester compound containing a hydroxyl group, the ester compound containing a hydroxyl group being an ester compound of one molecule of an m-valent alcohol (m represents an integer of 1 to 3) and n molecules (n represents an integer of 1 to m) of a monovalent carboxylic acid.