Butyl Rubber Hose Composition for Refrigerant Barrier

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing composite flexible hoses for refrigerant transportation lack sufficient water barrier properties and tensile strength, and require adhesive layers for adhesion, which increases costs and complexity.

Innovation Solution

A butyl rubber composition incorporating styrene-isobutylene block copolymer, white filler, brominated alkylphenol-formaldehyde resin, phenol resin, and methylol melamine, which allows direct vulcanization adhesion to resin without adhesives, improving water barrier properties while maintaining flexibility and tensile strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an adhesive component is kneaded into the butyl rubber intermediate layer to achieve direct vulcanization adhesion with the polyamide resin innermost layer, then adhesion strength is improved, but water barrier properties deteriorate because the adhesive component is highly hydrophilic

Engineering Contradiction:

Improveadhesion strengthVSAvoidwater permeation

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent removes the adhesive component from the rubber composition entirely. Instead of adding adhesive to achieve bonding, the invention uses a polyamide resin layer as the innermost layer that inherently provides both adhesion to the rubber layer and gas barrier properties, eliminating the need for separate adhesive components and thus preventing water permeation issues.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The polyamide resin innermost layer serves multiple functions simultaneously: it provides adhesion to the butyl rubber intermediate layer, maintains gas barrier properties, and prevents water permeation. This multi-functional approach eliminates the need for separate adhesive layers while addressing all requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of manufacture

If polybutene and white filler are added to the butyl rubber innermost layer to improve gas barrier properties and flexibility, then processability is improved, but tensile strength becomes insufficient

Engineering Contradiction:

ImproveprocessabilityVSAvoidtensile strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The patent assigns different functional qualities to different layers: the butyl rubber intermediate layer contains polybutene and white filler for flexibility and gas barrier properties, while the polyamide resin innermost layer provides the necessary tensile strength and adhesion. This local differentiation allows each layer to optimize its specific function without compromising overall performance.

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If the butyl rubber innermost layer is used to improve flexibility and gas barrier properties, then water barrier properties are enhanced, but direct vulcanization adhesion with the polyamide resin layer cannot be achieved

Engineering Contradiction:

Improvewater barrier propertiesVSAvoiddirect vulcanization adhesion

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

Instead of making the butyl rubber layer the innermost layer and attempting to achieve adhesion to polyamide, the patent inverts the arrangement by making polyamide resin the innermost layer. This inversion naturally provides the adhesion interface while maintaining the water barrier properties of the butyl rubber intermediate layer.

Inventive Principle:

Principle #13The other way round (Inversion)

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 solution provides a hose with enhanced water barrier properties, strong adhesion to resin, and maintained extrusion molding characteristics and tensile strength, making it suitable for refrigerant transportation without the need for adhesive layers.

Implementation Method 1

gas barrier properties for restraining the permeation of refrigerant gas

Methodology Applied

Scientific EffectPermeation: Permeation

Implementation Method 2

direct vulcanization adhesion with the polyamide resin in the innermost layer

Methodology Applied

Scientific EffectVulcanization:

Data Source

PatentUS9644094B2Butyl rubber composition and hose using same

Publication Date: 2017.05.09 NICHIRIN CO LTD

AI summary

A butyl rubber composition is preferably used for an intermediate rubber layer 3 of a composite flexible hose formed by laminating, from the inner side, an innermost layer 2, intermediate rubber layer 3, fiber reinforcement layer 4, and an external rubber layer 5 in this order. The butyl rubber composition includes halogenated butyl rubber, styrene-isobutylene block copolymer, white filler, white reinforcing agent, brominated alkylphenol-formaldehyde resin, phenol resin, and methylol melamine, and 5 to 45 parts by weight of the styrene-isobutylene block copolymer is added to 100 parts by weight of the halogenated butyl rubber.