Simultaneous Rubber Vulcanization and Coating Curing
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Solution Overview
Problem
Existing processes for producing rubber items with antifriction coatings are lengthy and prone to delamination due to inadequate bonding between the rubber surface and the coating layer, making them unsuitable for inline manufacturing and mass production.
Innovation Solution
A solvent-free coating process involving a rubber composition with a crosslinking agent and a coating composition amenable to free-radical polymerization, where both the rubber and coating compositions are crosslinked simultaneously at elevated temperatures, forming a strong covalent bond between the rubber and the coating layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rubber item is coated with an antifriction lacquer and then cured separately, then the antifriction properties are improved, but the production time is excessive and the coating tends to delaminate
Solution Approach 1:
The patent combines the vulcanization of rubber and curing of coating into a single simultaneous process step. The coating composition contains monomers amenable to free-radical polymerization that can be initiated by the same peroxide crosslinking agents used for rubber vulcanization. This merging eliminates the need for separate curing steps, significantly reducing production time while maintaining reliable antifriction properties through proper coating formulation and process parameter optimization.
2Reliability
If the rubber item is coated with an antifriction lacquer and then cured separately, then the antifriction properties are improved, but the coating delaminates due to inadequate bonding
Solution Approach 1:
The simultaneous vulcanization and curing process creates strong bonding between coating and rubber through coordinated crosslinking reactions. The peroxide crosslinking agents generate free radicals that simultaneously crosslink the rubber and polymerize the coating monomers, creating a unified structure with excellent interfacial adhesion that prevents delamination while maintaining reliable antifriction properties.
Solution Approach 2:
The patent carefully controls process parameters including temperature, peroxide concentration, and coating composition to optimize both bonding strength and antifriction properties. By adjusting these parameters, the simultaneous curing process achieves adequate bonding between coating and rubber surface while maintaining the desired low-friction surface characteristics.
3Reliability
If a multistage curing process is used for coating rubber items, then the coating can be applied, but the process complexity increases and is unsuitable for inline manufacture
Solution Approach 1:
The patent merges multiple curing stages into a single simultaneous process step where rubber vulcanization and coating curing occur together. This is achieved by formulating the coating with monomers that can be polymerized by peroxide-generated free radicals, the same mechanism used for rubber crosslinking. The simplified single-step process maintains coating application quality while enabling inline manufacturing with reduced process complexity and equipment requirements.
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
This process significantly reduces production time and costs, prevents delamination, and achieves a durable, friction-reducing surface coating with improved antifriction properties by forming a large number of covalent bonds between the rubber and the coating layer.
Implementation Method 1
a coating composition which comprises no solvent and at least one monomer amenable to free-radical polymerization
Implementation Method 2
which comprises a peroxide crosslinking agent and at least one initiator, in particular a thermal initiator... the crosslinking of the rubber composition takes place at the same time as the polymerization of the coating composition
Data Source
AI summary
A process for the production of a coated rubber item, comprising:(i) provision of a semifinished product having the main shape of the rubber item, where the semifinished product is composed of a rubber composition comprising at least one rubber and at least one crosslinking agent;(ii) coating of the semifinished product with a solvent-free coating composition comprising at least one monomer amenable to free-radical polymerization,(iii) crosslinking of the rubber composition and polymerization of the coating composition, to give a coated rubber item;wherein the boiling point of the at least one monomer amenable to free-radical polymerization is ≥150° C. and the crosslinking of the rubber composition takes place at the same time as the polymerization of the coating composition.