EPDM Rubber Composition for Mold Contamination Resistance
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Solution Overview
Problem
Ethylene/propylene-based copolymer rubber compositions face significant mold contamination issues, leading to decreased production efficiency due to frequent mold cleaning requirements, which existing solutions fail to adequately address while maintaining material physical properties.
Innovation Solution
An ethylene/propylene-based copolymer rubber composition incorporating a benzimidazole-based antioxidant, an ether ester-based plasticizer, and a primary antioxidant, with specific weight ratios to enhance mold contamination resistance and maintain heat resistance and compression set characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional rubber compositions are used, then production volume is high, but mold contamination occurs frequently requiring frequent cleaning
Solution Approach 1:
The patent changes the chemical composition parameters of the rubber compound by incorporating specific antioxidants (2,2,4-trimethyl-1,2-dihydroquinoline at 0.1-1.0 parts, benzimidazole-based antioxidants at 0.3-2.0 parts) and plasticizers (ether ester-based at 1-10 parts, paraffinic process oil at 1-5 parts) per 100 parts of EPDM. This compositional parameter adjustment reduces mold contamination while maintaining high production efficiency.
Solution Approach 2:
The patent creates a composite rubber composition by combining EPDM base polymer with multiple functional additives including primary antioxidants, secondary antioxidants (benzimidazole-based), and specific plasticizers. This composite material approach achieves both high productivity and reduced mold contamination through synergistic effects of the components.
2Object-generated harmful factors
If mold cleaning frequency is increased, then mold contamination is reduced, but production efficiency decreases due to downtime
Solution Approach 1:
The patent applies preliminary action by incorporating specific antioxidant and plasticizer combinations into the rubber compound formulation before molding. This preventive measure reduces mold contamination at its source, eliminating the need for frequent mold cleaning and maintaining continuous production efficiency.
3Temperature
If secondary antioxidants are added to improve heat resistance, then heat resistance is improved, but mold contamination increases
Solution Approach 1:
The patent applies local quality by selecting specific types of secondary antioxidants (benzimidazole-based) and controlling their concentration (0.3-2.0 parts per 100 parts EPDM). This localized optimization of antioxidant properties maintains heat resistance while minimizing mold contamination compared to using conventional secondary antioxidants.
Solution Approach 2:
The patent changes the parameter of secondary antioxidant type from conventional options to benzimidazole-based antioxidants, and adjusts the concentration parameter to 0.3-2.0 parts per 100 parts EPDM. This parameter change achieves the dual benefit of maintaining heat resistance while reducing mold contamination.
4Object-generated harmful factors
If mold release agents are changed to reduce contamination, then mold contamination is reduced, but vulcanization time cycle deteriorates
Solution Approach 1:
The patent extracts the mold contamination problem from the mold surface and relocates it to the rubber compound formulation through the use of specific antioxidants and plasticizers. This extraction approach reduces mold contamination without requiring changes to mold release agents that would affect vulcanization time.
Data Source
AI summary
An ethylene/propylene-based copolymer rubber composition having excellent mold contamination resistance obtained by adding a primary antioxidant, a secondary antioxidant, and a plasticizer to ethylene/propylene-based copolymer rubber, wherein based on 100 parts by weight of the ethylene/propylene-based copolymer rubber, 0.3 parts by weight or more of the benzimidazole-based antioxidant (A) is contained as the secondary antioxidant, less than 10 parts by weight of the ether ester-based plasticizer (B) is contained as the plasticizer, and the (B)/(A) ratio is 4.0 times or more.