Method for stabilising silicone elastomer moulds
AssigneeRhodia Chimie
InventorsJérôme Bressieux, Thomas Deforth, Christian Pusineri
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Abstract
The invention concerns the use for increasing the life span of molds made of silicone elastomer crosslinking by polyaddition or polycondensation reaction, of an additive capable of stabilizing the silicone elastomer whereof the mold is constituted with respect to materials to be mouded, said additive corresponding the following formula (1) wherein R1 and R2 are linear or branched alkyl radicals or cycloaliphatic radicals having 1 to 40 carbon atoms. Preferably, said additive is methyl laurylthiopropionate. C12H25—S—CH2—CH2—CO—O—CH3. The invention also concerns the corresponding silicone compositions and the resulting molds.
Claims24
A method for increasing the longevity of molds made of silicone elastomer which crosslinks by a polyaddition or polycondensation reaction comprising using an additive capable of stabilizing the silicone elastomer constituting the mold with respect to the materials to be molded, the additive corresponding to the following formula (1):
- in which R1 and R2 are linear or branched alkyl radicals or cycloaliphatic radicals having from 1 to 40 carbon atoms.
A method for increasing the longevity of molds made of silicone elastomer which crosslinks by a polyaddition or polycondensation reaction, the method comprising using an additive capable of stabilizing the silicone elastomer constituting the mold with respect to the materials to be molded, the additive corresponding to the following formula (1):
- in which R1 and R2 are linear or branched alkyl radicals or cycloaliphatic radicals having from 1 to 40 carbon atoms, wherein the additive comprises methyl lauryithiopropionate MeLTP:
- C12H25—S—CH2—CH2—CO—O—CH3.
A method for increasing the longevity of molds made of silicone elastomer which crosslinks by a polyaddition or polycondensation reaction, the method comprising using an additive capable of stabilizing the silicone elastomer constituting the mold with respect to the materials to be molded, the additive corresponding to the following formula (1):
- in which R1 and R2 are linear or branched alkyl radicals or cycloaliphatic radicals having from 1 to 40 carbon atoms, wherein R1 and R2 are such that R1+R2≦20 and, further involving a second additive wherein R1 and R2 are such that R1+R2>20.
A method for increasing the longevity of molds made of silicone elastomer which crosslinks by a polyaddition or polycondensation reaction, the method comprising using an additive capable of stabilizing the silicone elastomer constituting the mold with respect to the materials to be molded, the additive corresponding to the following formula (1):
- in which R1 and R2 are linear or branched alkyl radicals or cycloaliphatic radicals having from 1 to 40 carbon atoms, wherein the composition comprises another stabilization additive selected from the group consisting of:
- phosphates,
- sterically hindered phenols,
- aromatic amines and HALS hindered amines,
- metal thiophosphates,
- metal salts with an oxidizing action,
- additives comprising, in their structure, at least 2 groups of formula
- —Ra—OOC—Rb—S—Rc
- in which:
- the Ra radicals are, independently of one another, selected from the group consisting of divalent hydrocarbonaceous groups having from 1 to 6 carbon atoms;
- the Rb radicals are monovalent hydrocarbonaceous groups;
- the Rc radicals are selected from the group consisting of alkyls having from 1 to 40 carbon atoms, and
- additives of formula Rd—OOC—Re—S—Rf—COO—Rg
- in which:
- the Rd and Rg radicals, independently of one another, are selected from the group consisting of linear or branched alkyl radicals having from 1 to 40 carbon atoms;
- the Re and Rf radicals, independently of one another, are divalent hydrocarbonaceous groups.
A precursor silicone composition of a silicone elastomer which can be used for the formation of molds for the molding of polyester items, comprising, as a stabilization additive, at least one additive corresponding to the following formula (1):
- in which R1 and R2 are linear or branched alkyl radicals or cycloaliphatic radicals having from 1 to 40 carbon atoms.
A method of molding an object, the method comprising molding the object with a mold made of a silicone elastomer which crosslinks by a polyaddition or a polycondensation reaction, wherein the silicone elastomer is stabilized with respect to the object being molded with an additive corresponding to the formula (1):
- in which R1 and R2 are linear or branched alkyl radicals or cycloaliphatic radicals having 1 to 40 carbon atoms.
Dependencies are inferred from the claim text.