PVC-C Adhesive Composition for Heat-Resistant Plastic Pipe Bonding

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Solution Overview

Problem

Existing adhesives for bonding plastic parts, particularly PVC and ABS, face challenges with pressure and temperature resistance, storage stability, and compatibility, especially when avoiding tetrahydrofuran (THF) as a solvent.

Innovation Solution

A solvent-based adhesive composition using a solution of PVC-C resin in butan-2-one, with specific weight percentages and optional co-solvents, providing improved pressure and temperature stability, storage stability, and compatibility with plastic materials, potentially eliminating the need for thickeners.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If THF-free adhesive formulations based on 2-methyltetrahydrofuran are used to extend open time, then open time is improved, but pressure resistance at elevated temperatures deteriorates

Engineering Contradiction:
Improveopen timeVSAvoidpressure resistance at elevated temperatures
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the adhesive by using butan-2-one as the primary solvent instead of 2-methyltetrahydrofuran, and by carefully controlling the PVC-C resin content (15-25% by weight) and butan-2-one content (70-85% by weight). This parameter change resolves the contradiction by achieving both extended open time and maintained pressure resistance at elevated temperatures.

Inventive Principle:
Principle #35Parameter changes

2Strength

If conventional PVC solution adhesives with cyclic PVC solvents are used, then bonding capability is achieved, but toxicological concerns arise

Engineering Contradiction:
Improvebonding capabilityVSAvoidtoxicity
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and eliminates the harmful cyclic PVC solvents (such as THF) from the adhesive formulation while maintaining the essential bonding functionality. By using butan-2-one as a replacement solvent that is less toxic, the patent achieves bonding capability without the harmful toxicological effects of conventional cyclic solvents.

Inventive Principle:
Principle #2Taking out (Extraction)

3Strength

If adhesive formulations with high polymer content are used to improve bond strength, then bonding strength is improved, but storage stability deteriorates

Engineering Contradiction:
Improvebond strengthVSAvoidstorage stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent optimizes the parameter of polymer content to a specific range (15-25% by weight of PVC-C resin) that balances bond strength and storage stability. This parameter optimization ensures that the adhesive has sufficient bonding strength while maintaining excellent storage stability, preventing the contradiction between strength and stability.

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 adhesive composition achieves high-pressure and temperature resistance, excellent storage stability, and compatibility with plastic materials, ensuring durable and long-lasting bonds, particularly suitable for PVC and ABS plastics.

Implementation Method 1

The solvents diffuse into the base material, swell it

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

The solvents diffuse into the base material, swell it

Methodology Applied
Scientific EffectSwelling:

Implementation Method 3

The solvents desorb over a period of time

Methodology Applied
Scientific EffectDesorption: Desorption

Data Source

PatentEP3366744B1Adhesive composition to join parts made of plastic
Publication Date: 2021.03.31 HENKEL KGAA

AI summary

The invention is in the field of adhesives. In particular, it relates to a means for gluing molded parts made of plastic, in particular plastic pipes, comprising a PVC-C resin with a K value of less than or equal to 55 and butan-2-one as a solvent, and a method for the material connection of plastic -pipes and a pipe assembly consisting of at least two plastic pipes.