PVB Resin Melt Viscosity Control via Hydrogen Peroxide Decomposition

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Solution Overview

Problem

The manufacturing of multiple layer glass panels faces challenges such as delamination and bubbling due to inefficient de-airing, especially when using warped or wavy glass substrates, which affects the optical clarity and structural integrity, and existing solutions like increasing interlayer thickness or flowability come with additional costs and issues like creep and limited molecular weight variability.

Innovation Solution

Incorporating hydrogen peroxide into the melt blend of poly(vinyl butyral) (PVB) resin to control melt viscosity and flowability, allowing for the production of PVB sheets with selectable flow characteristics, thereby improving de-airing efficiency and reducing surface roughness while avoiding the drawbacks of previous methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If interlayer thickness is increased to improve de-airing efficiency, then de-airing efficiency is improved, but manufacturing cost increases

Engineering Contradiction:
Improvede-airing efficiencyVSAvoidinterlayer thickness
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent changes the molecular weight parameter of the PVB resin by blending resins of different molecular weights (e.g., 100,000 g/mol and 200,000 g/mol) to achieve optimal melt viscosity for de-airing, eliminating the need to increase interlayer thickness. This parameter adjustment allows thin interlayers to maintain high de-airing efficiency during lamination.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If PVB resin flowability is increased to improve de-airing, then de-airing efficiency is improved, but creep resistance deteriorates

Engineering Contradiction:
Improvede-airing efficiencyVSAvoidcreep resistance
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent optimizes the molecular weight distribution parameter of the PVB resin blend to achieve a balance where the resin has sufficient flowability for de-airing while maintaining creep resistance. The specific blend ratio and molecular weight range are controlled to ensure both de-airing efficiency and dimensional stability under load.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite PVB resin system by blending resins of different molecular weights, where the lower molecular weight resin provides flowability for de-airing and the higher molecular weight resin provides creep resistance, achieving both properties simultaneously in a single interlayer material.

Inventive Principle:
Principle #40Composite materials

3Stability of the object's composition

If molecular weight variability is limited to maintain creep resistance, then creep resistance is improved, but de-airing efficiency deteriorates

Engineering Contradiction:
Improvecreep resistanceVSAvoidde-airing efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent deliberately broadens the molecular weight variability parameter by using a blend of PVB resins with different molecular weights, which increases melt viscosity control and improves de-airing efficiency while maintaining creep resistance through the synergistic effect of the blend components.

Inventive Principle:
Principle #35Parameter changes

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 use of hydrogen peroxide in the PVB melt blend results in PVB sheets with lower melt viscosity and reduced surface roughness, enhancing the de-airing process and reducing the likelihood of delamination and bubbling, while also offering tunable flowability and molecular weight distribution for improved panel performance.

Implementation Method 1

incorporating hydrogen peroxide into the melt blend of poly(vinyl butyral) (PVB) resin to control melt viscosity and flowability

Methodology Applied
Scientific EffectDecomposition: Decomposition (biological)

Data Source

PatentEP2969550B1Hydrogen peroxide as a reactive extrusion additive for poly(vinyl butyral)
Publication Date: 2017.04.26 SOLUTIA INC
  • EP2969550B1 patent drawingFigure 1
  • EP2969550B1 patent drawingFigure 2

AI summary

A poly(vinyl butyral) (PVB) resin formulation, a method of extruding PVB resins, and related materials and products that provide for PVB sheets with a selectable flow (or melt viscosity) by melt blending hydrogen peroxide (H2O2) into a PVB resin composition is described herein.