Polyacetal Sliding Resin Composition for Low-Wear Clean Molding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyacetal resin compositions face issues with lubricating oil exudation and delamination during molding, leading to poor appearance and mold contamination, despite previous attempts to improve friction and wear properties.
Innovation Solution
A polyacetal resin composition incorporating a hindered phenol antioxidant, non-surface treated precipitated calcium carbonate, and a specific fatty acid, along with silicone oil, is used to enhance friction and wear properties while preventing mold contamination and maintaining the appearance of molded articles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluororesin or polyolefin resin is added to polyacetal resin to improve sliding properties, then friction and wear resistance is improved, but compatibility is poor causing delamination and mold deposit
Solution Approach 1:
The patent introduces a specific coupling agent as an intermediary substance between the polyacetal resin and the fluororesin/polyolefin resin. This coupling agent has functional groups that can chemically bond to both the polyacetal resin and the added resin, creating a stable interface that prevents delamination while maintaining the improved sliding properties provided by the fluororesin or polyolefin resin.
Solution Approach 2:
The patent optimizes the composition parameters by specifying precise ratios of polyacetal resin, fluororesin/polyolefin resin, and coupling agent. By carefully controlling these parameters, the patent achieves a balanced composition where the added resin provides friction and wear resistance without causing compatibility issues, thus resolving the contradiction between reliability improvement and compositional stability.
2Reliability
If lubricating oil is added to polyacetal resin to improve sliding properties, then friction is reduced, but exudation occurs during molding causing appearance deterioration and processability impairment
Solution Approach 1:
The patent uses a coupling agent as an intermediary that binds the lubricating oil to the polyacetal resin matrix, preventing the oil from separating and exuding during the molding process. This intermediary substance anchors the lubricating oil within the resin structure, allowing the beneficial sliding properties to be maintained without the harmful exudation effect.
Solution Approach 2:
The patent specifies optimal concentrations of lubricating oil and coupling agent to achieve the desired balance. By controlling these parameters, the patent ensures sufficient lubrication for good sliding properties while preventing excessive oil content that would lead to exudation and appearance deterioration during molding.
3Reliability
If polyethylene wax and silicone oil are added to polyacetal resin to improve sliding properties, then friction and wear resistance is improved, but exudation and delamination still occur during molding
Solution Approach 1:
The patent introduces a coupling agent that acts as an intermediary between the polyacetal resin and the additives (polyethylene wax and silicone oil). This coupling agent enhances the interfacial adhesion and prevents phase separation, thereby maintaining compositional homogeneity while preserving the friction and wear resistance benefits of the additives during the molding process.
Solution Approach 2:
The patent creates a composite material system where polyacetal resin is combined with polyethylene wax, silicone oil, and a coupling agent. This composite structure leverages the complementary properties of each component: polyacetal provides the base mechanical strength, polyethylene wax and silicone oil provide lubrication, and the coupling agent ensures homogeneous integration, collectively achieving both improved sliding properties and compositional stability.
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 composition achieves excellent friction and wear properties while minimizing mold contamination and surface delamination, resulting in improved performance and appearance of molded articles.
Implementation Method 1
a hindered phenol antioxidant
Implementation Method 2
a silicone oil
Implementation Method 3
non-surface treated precipitated calcium carbonate
Implementation Method 4
a specific fatty acid
Data Source
AI summary
The purpose of an embodiment of the present invention is to provide a polyacetal resin composition and a sliding member, the polyacetal resin composition having excellent performance with respect to friction/abrasion characteristics while maintaining good appearance of a molded article thereof or low occurrence of mold contamination during molding. The purpose of an embodiment of the present invention is achieved by a polyacetal resin composition containing at least (A) 100 parts by mass of a polyacetal resin, (B) 0.01 part by mass to 1 part by mass of a hindered-phenol-based antioxidant, (C) 0.3 part by mass to 5 parts by mass of silicone oil, (D) 0.1 part by mass to 1.0 part by mass of calcium carbonate, and (E) 0.02 part by mass to 0.2 part by mass of a fatty acid, the calcium carbonate (D) being precipitated calcium carbonate which is not surface-treated and which has an average particle diameter of 1 pm or less, and the fatty acid (E) being a C12-30 fatty acid.