Polyvinyl Acetal Interlayer for Laminated Glass Sound Insulation
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Solution Overview
Problem
Laminated glasses used in vehicles, especially those with internal combustion engines, require improved sound-insulating properties in low frequency ranges, while those used in electric vehicles need enhanced sound-insulation in high frequency ranges, with existing interlayer films exhibiting insufficient performance over a wide temperature range and being prone to coincidence effects.
Innovation Solution
An interlayer film comprising multiple layers of polyvinyl acetal resin and plasticizer, with specific acetylation degrees and cloud points, is used to enhance sound-insulating properties in high frequency ranges over a wide temperature range, achieved by varying the acetylation degrees and cloud points of the polyvinyl acetal resins and plasticizer ratios in each layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the thickness of laminated glass is reduced to decrease weight, then the weight is reduced, but the sound-insulating property deteriorates
Solution Approach 1:
The invention changes the chemical composition parameters of the polyvinyl acetal resin, specifically controlling the acetalization degree within 60-85 mol% and acetylation degree within 0.1-30 mol%, to optimize sound insulation performance while maintaining thin film thickness
Solution Approach 2:
The invention uses composite material formulation by combining polyvinyl acetal resin with specific plasticizers in controlled ratios, creating a material that achieves both lightweight and high sound-insulating properties through optimized compositional parameters
2Strength
If the acetalization degree of polyvinyl acetal resin is increased to improve adhesion, then the adhesion is improved, but the sound-insulating property in high frequency range deteriorates
Solution Approach 1:
The invention optimizes the acetalization degree parameter within the specific range of 60-85 mol%, balancing the competing requirements of adhesion strength and high-frequency sound insulation by preventing excessive chain rigidity that would cause coincidence effects
3Ease of operation
If the acetylation degree of polyvinyl acetal resin is increased to improve flexibility, then the flexibility is improved, but the sound-insulating property over wide temperature range deteriorates
Solution Approach 1:
The invention precisely controls the acetylation degree parameter within 0.1-30 mol% to maintain appropriate molecular chain flexibility across temperature variations, preventing both excessive flexibility that causes coincidence effects and insufficient flexibility that reduces comfort
4Ease of operation
If the plasticizer content is increased to improve flexibility, then the flexibility is improved, but the cloud point increases causing insufficient sound insulation at low temperatures
Solution Approach 1:
The invention optimizes the plasticizer content parameter within 20-70 parts by weight per 100 parts of resin, balancing flexibility improvement with maintaining low cloud point for consistent sound insulation performance across temperature ranges
Solution Approach 2:
The invention selects specific types of plasticizers with appropriate molecular structures to achieve localized optimization of flexibility while minimizing impact on cloud point, creating non-uniform molecular distribution that prevents coincidence effects
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 interlayer film significantly improves sound-insulating properties in high frequency ranges over a wide temperature range, effectively addressing the limitations of existing films by optimizing the acetylation degrees and cloud points of the polyvinyl acetal resin and plasticizer combinations in each layer.
Implementation Method 1
an interlayer film for laminated glass which contains a polyvinyl acetal resin and a plasticizer
Implementation Method 2
enhance sound-insulating properties in high frequency ranges
Implementation Method 3
the coincidence effect is a phenomenon that, when sound waves strike a glass plate, the transverse wave is propagated on the glass surface due to the rigidity and inertia of the glass plate, and then the transverse wave resonates with the incident sound
Data Source
Figure 1~3
Figure 4
AI summary
The present invention provides an interlayer film for laminated glass which can enhance, when used in a laminated glass, the sound-insulating property of the laminated glass in a high frequency range over a wide temperature range. An interlayer film for laminated glass of the present invention includes first, second, and third layers, wherein when a cloud point C1 is measured by using a first liquid containing 100 parts by weight of a first plasticizer and 8 parts by weight of a first polyvinyl acetal resin contained in the first layer, a cloud point C2 is measured by using a second liquid containing 100 parts by weight of a second plasticizer and 8 parts by weight of a second polyvinyl acetal resin contained in the second layer, and a cloud point C3 is measured by using a third liquid containing 100 parts by weight of a third plasticizer and 8 parts by weight of a third polyvinyl acetal resin contained in the third layer, the cloud point C1 is 10°C or lower; the cloud point C2 is higher than the cloud point C1 by at least 5°C; and the cloud point C3 is higher than the cloud point C1 by at least 50°C and higher than the cloud point C2.