Modified Silicon Oil for Low-Temperature Die Casting Release
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Solution Overview
Problem
Conventional silicon oils used in pressure die casting release agents require temperatures above 225°C to form a solid film, which limits their effectiveness on cooler parts of the die, leading to decreased release properties.
Innovation Solution
A mixture of polyalkylsiloxanes obtained through a hydrosilylation reaction involving polyenes like (R)-limonene and monounsaturated olefins, such as 1-dodecene, which cures and forms a film at temperatures as low as 170°C, enabling effective release on cooler die surfaces while maintaining high temperature stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional silicon oils are used to form a solid film on the die, then high temperature stability and release properties are achieved, but the curing temperature must be above 225°C which prevents solid film formation on cooler parts of the die
Solution Approach 1:
The patent modifies the chemical structure of silicon oil by introducing vinyl groups through partial vinylation reaction, which changes the curing temperature parameter from above 225°C to between 170-225°C. This allows the lubricant to form solid films on cooler die surfaces while maintaining high temperature stability and release properties through the preserved siloxane backbone structure.
Solution Approach 2:
The invention creates a composite lubricant system combining modified vinyl-containing silicon oil with unmodified silicon oil and additives. This composite approach allows the vinyl-modified component to cure at lower temperatures on cooler die parts while the unmodified silicon oil provides high temperature stability, achieving both low-temperature film formation and high-temperature performance.
2Use of energy by stationary object
If the die temperature is kept cooler to influence casting quality or cast with lower melting metals, then energy consumption and operating costs are reduced, but conventional silicon oils cannot form solid films due to insufficient temperature
Solution Approach 1:
By chemically modifying silicon oil to contain vinyl groups, the curing temperature parameter is shifted to 170-225°C range. This enables solid film formation at lower die temperatures, allowing energy-efficient casting processes with lower melting metals while ensuring complete surface coverage and proper film formation even on cooler die sections.
3Area of stationary object
If silicon oil is applied to ensure complete surface coverage, then release function is improved, but on cooler spots the oil remains uncured and release properties decrease
Solution Approach 1:
The vinyl modification lowers the curing temperature threshold, enabling the lubricant to cure completely across the entire die surface area including cooler spots. The modified silicon oil forms solid films at 170-225°C, ensuring uniform release properties across all die surfaces regardless of local temperature variations from cooling channels or thick casting sections.
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 new silicon oil effectively forms a film at lower temperatures, enhancing release properties on cooler die parts and maintaining stability comparable to existing silicon oils, with a curing process completed below 190°C and decomposition above 520°C.
Implementation Method 1
a mixture of polyalkylsiloxanes obtainable through a hydrosilylation reaction wherein a mixture of ethylenically unsaturated olefins... is reacted with an amount of one or more polyalkylhydrosiloxanes in the presence of a hydrosilylation catalyst
Implementation Method 2
Formation of such a solid film on the die by curing at these temperatures allows the lubricant to practice its release function
Data Source
AI summary
The present invention relates to a mixture of polyalkylsiloxanes that cure at comparably low temperatures of about 170°C while being unreactive under ambient conditions during storage or transport and which are obtainable through a hydrosilylation reaction wherein a mixture of ethylenically unsaturated olefins consisting of 1-100 % of one or more polyene(s) having one terminal double bond which is either monosubstituted or geminal disubstituted and one or more tri- or tetrasubstituted double bond(s), wherein said terminal double bond and said one or more tri- or tetrasubstituted double bond(s) are preferably non-conjugated, and 0-99 mol % of monounsaturated olefins with 6 to 15 carbon atoms is reacted with an amount of one or more polyalkylhydrosiloxanes in the presence of a hydrosilylation catalyst. Furthermore, the present invention relates to water-based compositions suitable for use in metal casting processes as a mold release agent comprising a mixture of polyalkylsiloxanes of the invention and a non-ionic surfactant having a HLB value of at least 8. In addition, the present invention relates to the use of the polyalkylsiloxanes and mixtures of polyalkylsiloxanes as defined herein.