Sulfur-Linkable Rubber Mixture Adhesion Safety

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Solution Overview

Problem

Methylene acceptor reactants like resorcinol and phenol in sulfur-crosslinkable rubber mixtures pose occupational safety and environmental risks due to vaporization and toxicity, leading to contamination and health hazards during processing, and existing alternatives do not consistently achieve desired adhesion and stiffness for all tire applications.

Innovation Solution

A sulfur-crosslinkable rubber mixture using a resorcinol-formaldehyde resin with dicyclopentadiene and styrene functionalization as the methylene acceptor, which has a free resorcinol content of less than 0.1% and free phenol content of less than 1% by weight, enhancing adhesion and reducing environmental and health risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If resorcinol and phenol are used as methylene acceptor reactants in sulfur-crosslinkable rubber mixtures, then adhesion to reinforcements is achieved, but occupational safety and environmental protection are compromised due to vaporization and toxicity

Engineering Contradiction:

Improveadhesion to reinforcementsVSAvoidoccupational safety and environmental protection

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by using modified resorcinol-formaldehyde resins with reduced free phenol content (less than 0.5% by weight) and incorporating specific additives that alter the vaporization characteristics. This maintains the adhesion function while reducing harmful emissions during processing

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs alternative methylene acceptor reactants that are less hazardous and can be used in controlled amounts, replacing the need for large quantities of resorcinol and phenol. These alternatives provide sufficient adhesion without the severe health and environmental risks

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Strength

If resorcinol is used as methylene acceptor, then adhesion is achieved, but contamination and cleaning effort increase due to evaporation and deposition on cooler components

Engineering Contradiction:

ImproveadhesionVSAvoidcontamination and cleaning effort

Core Design Contradiction:

StrengthVSLoss of substance

Solution Approach 1:

The patent modifies the volatile components by using resorcinol-formaldehyde resins with controlled free phenol content and adding specific compounds that reduce vaporization. This decreases deposition on cooler components and subsequent contamination

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful vaporization behavior into a benefit by using alternatives that vaporize less, thereby reducing contamination. The reduced volatility becomes an advantage rather than a disadvantage, minimizing cleaning requirements

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Object-affected harmful factors

If existing alternative methylene acceptors are used to avoid resorcinol and phenol, then occupational safety improves, but adhesion and stiffness may not be sufficient for all tire applications

Engineering Contradiction:

Improveoccupational safetyVSAvoidadhesion and stiffness

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent creates a composite approach by combining modified resorcinol-formaldehyde resins with specific additives and methylene donors. This composite system maintains adhesion and stiffness properties while improving occupational safety, achieving a balance that single alternatives cannot provide

Inventive Principle:

Principle #40Composite materials

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 resin achieves good or improved adhesion to reinforcements with minimal negative impact on vulcanizate properties, reducing contamination and health hazards while maintaining effective adhesion and stiffness, thus improving occupational safety and environmental protection.

Implementation Method 1

During the vulcanization process, a resin is formed from the methylene donor and the methylene acceptor

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

Resorcinol has a relatively high vapor pressure at the processing temperatures of a rubber coating mixture, so that it can be used e.g. T. evaporates during processing and is deposited on cooler components

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3636451B1Sulphur linkable natural rubber mixture

Publication Date: 2022.01.12 CONTINENTAL REIFEN DEUTSCHLAND GMBH

AI summary

The invention relates to a sulfur-crosslinkable rubber compound comprising a methylene acceptor-methylene donor pair. The invention further relates to a vehicle tire comprising at least one such sulfur-crosslinked rubber compound. For good adhesion to reinforcing materials, while improving occupational safety and environmental protection, the methylene acceptor is a resorcinol-formaldehyde resin with dicyclopentadiene and styrene functionalization, reactive to react with a methylene donor, wherein the resorcinol-formaldehyde resin has a free resorcinol content of less than 5 wt% and a free phenol content of less than 5 wt%.