JP-2026514244-A - Stabilizer for polymer foams based on the regeneration of polydimethylsiloxane

JP2026514244AJP 2026514244 AJP2026514244 AJP 2026514244AJP-2026514244-A

Abstract

Inventors

トーマスローゼン
ミヒャエルフェレンツ
マティアスローベアト
カーステンシラー

Assignees

エボニックオペレーションズゲーエムベーハー

Dates

Publication Date: 20260507
Application Date: 20240425
Priority Date: 20230503

Claims (14)

A method for producing polyether polydimethylsiloxane, (a) A cyclic polydimethylsiloxane-containing composition comprising at least one cyclic polydimethylsiloxane is subjected to an equilibrium reaction with at least one poly(methylhydrogen)siloxane in the presence of at least one equilibrium catalyst to form a poly(methylhydrogen)-polydimethylsiloxane copolymer, (b) The poly(methylhydrogen)-polydimethylsiloxane copolymer obtained in step (a) is subjected to a hydrosilylation reaction with at least one polyether containing at least one carbon-carbon double bond that is reactive to the Si-H bond, preferably in the presence of at least one hydrosilylation catalyst, to obtain a polyether polydimethylsiloxane. The at least one cyclic polydimethylsiloxane is at least partially derived from at least one linear or branched polydimethylsiloxane or its copolymer. The cyclic polydimethylsiloxane-containing composition contains up to 300 ppm of water, measured according to DIN 51777:2020-04 based on the total weight of the cyclic polydimethylsiloxane-containing composition. The at least one linear or branched polydimethylsiloxane or its copolymer is contained in the polydimethylsiloxane-containing composition, and the polydimethylsiloxane-containing composition is A method comprising: - at least 50% (by weight), preferably at least 70% (by weight), or more preferably at least 90% (by weight), of at least one linear or branched polydimethylsiloxane or its copolymer, based on the total weight of the polydimethylsiloxane-containing composition, and/or - having a silicon content of 19% to 38% (by weight), preferably 26% to 38% (by weight), more preferably 34% to 38% (by weight), based on the total weight of the polydimethylsiloxane-containing composition, and/or - comprising less than 50% (by weight), preferably less than 25% (by weight), more preferably less than 5% (by weight), of a filler, based on the total weight of the polydimethylsiloxane-containing composition.
The method according to claim 1, wherein the cyclic polydimethylsiloxane-containing composition contains a maximum of 0.25 mol% of M units, preferably a maximum of 0.15 mol%, or more preferably a maximum of 0.05 mol%, based on the total moles of M, D, T, and Q units of the cyclic polydimethylsiloxane-containing composition, and/or the sum of T and Q units of the cyclic polydimethylsiloxane-containing composition is a maximum of 0.75 mol%, preferably a maximum of 0.5 mol%, or more preferably a maximum of 0.25 mol%, based on the total moles of M, D, T, and Q units of the cyclic polydimethylsiloxane-containing composition, and/or the sum of M, T, and Q units of the cyclic polydimethylsiloxane-containing composition is a maximum of 1.00 mol%, preferably a maximum of 0.65 mol%, or more preferably a maximum of 0.3 mol%, based on the total moles of M, D, T, and Q units of the cyclic polydimethylsiloxane-containing composition.
The aforementioned cyclic polydimethylsiloxane-containing composition - Based on the total weight of the cyclic polydimethylsiloxane-containing composition, measured according to DIN 51777:2020-04, up to 0.05% (by weight), preferably up to 100 ppm, more preferably up to 40 ppm (by weight), most preferably up to 10 ppm of water; and/or - Based on the total moles of M, D, T, and Q units in the cyclic polydimethylsiloxane-containing composition, as determined by Si-NMR spectroscopy, up to 0.25 mol%, preferably up to 0.15 mol%, or more preferably up to 0.05 mol% of M units; and/or - Based on the total moles of silicon atoms in the cyclic polydimethylsiloxane-containing composition, as determined by Si-NMR spectroscopy, up to 0.5 mol%, preferably up to 0.2 mol%, or more preferably up to 0.1 mol% of vinyl-substituted silicon atoms; and/or - Based on the total moles of silicon atoms in the cyclic polydimethylsiloxane-containing composition, The method according to claim 1 or 2, comprising up to 0.2 mol%, preferably up to 0.1 mol%, and more preferably up to 0.05 mol%, of hydroxyl-substituted silicon atoms as determined by Si-NMR spectroscopy.
The method according to any one of claims 1 to 3, wherein the at least one cyclic polydimethylsiloxane is at least one recycled cyclic polydimethylsiloxane.
The method according to any one of claims 1 to 4, wherein the at least one linear or branched polydimethylsiloxane or its copolymer corresponds to or is derived from waste polydimethylsiloxane polymer or copolymer material, wide-spec polydimethylsiloxane polymer or copolymer material, used polydimethylsiloxane polymer or copolymer material, expired polydimethylsiloxane polymer or copolymer material, surplus polydimethylsiloxane polymer or copolymer material, or any mixture or combination thereof.
The method according to any one of claims 1 to 5, wherein the at least one linear or branched polydimethylsiloxane or its copolymer is polydimethylsiloxane oil, polydimethylsiloxane elastomer, polydimethylsiloxane rubber, or a mixture thereof, wherein the polydimethylsiloxane oil preferably has a viscosity of at least 1000 mPa·s at 25°C as measured according to DIN 53019-1:2008-09.
The aforementioned at least one cyclic polydimethylsiloxane, From the above at least one linear or branched polydimethylsiloxane or its copolymer, - A polydimethylsiloxane-containing composition comprising at least one linear or branched polydimethylsiloxane or its copolymer is subjected to catalytic depolymerization in the presence of at least one depolymerization catalyst to form at least one cyclic polydimethylsiloxane in the depolymerization reaction mixture, and - The depolymerization reaction mixture is distilled to obtain the cyclic polydimethylsiloxane-containing composition comprising at least one cyclic polydimethylsiloxane, thereby at least partially derived. The method according to any one of claims 1 to 6, wherein the cyclic polydimethylsiloxane-containing composition is optionally subjected to additional fractional distillation and purification before being subjected to the equilibrium reaction.
The aforementioned poly(methylhydrogen)-polydimethylsiloxane copolymer Density of 0.95–0.98 g/mL, preferably 0.96–0.98 g/mL, or more preferably 0.97–0.98 g/mL, at 25°C, as measured according to DIN 51757:2011-01; The method according to any one of claims 1 to 7, wherein the viscosity is 2 to 2000 mPa·s, preferably 3 to 1000 mPa·s, or more preferably 10 to 500 mPa·s, at 25°C, as measured according to DIN 53019-1:2008-09; and/or the SiH value is 0.2 to 10 mol/kg, preferably 0.4 to 8 mol/kg, or more preferably 0.6 to 6 mol/kg, as measured by gas volumetric spectroscopy.
A composition for preparing a polymer foam comprising at least one monomer and one or more polyether polydimethylsiloxanes obtained by the method described in any one of claims 1 to 8, wherein the polymer foam is preferably a polyurethane foam, a phenolic resin foam, or a polyvinyl chloride foam, and more preferably a polyurethane foam.
A method for preparing a polymer foam, comprising reacting one or more monomer species in the presence of one or more polyether polydimethylsiloxanes obtained by the method described in any one of claims 1 to 8 to obtain a polymer foam.
An article comprising a polymer foam obtained according to the method described in claim 10, or as a reaction product of the composition described in claim 9.
The use of recycled cyclic polydimethylsiloxane for the production of polyether polydimethylsiloxane, wherein the recycled cyclic polydimethylsiloxane is derived from a linear or branched polydimethylsiloxane or its copolymer. The cyclic polydimethylsiloxane-containing composition contains up to 300 ppm of water, measured according to DIN 51777:2020-04 based on the total weight of the cyclic polydimethylsiloxane-containing composition. The at least one linear or branched polydimethylsiloxane or its copolymer is contained in the polydimethylsiloxane-containing composition, and the polydimethylsiloxane-containing composition is - Based on the total weight of the polydimethylsiloxane-containing composition, the composition comprises at least 50% (by weight), preferably at least 70% (by weight), or more preferably at least 90% (by weight), of at least one linear or branched polydimethylsiloxane or its copolymer; and/or - Based on the total weight of the polydimethylsiloxane-containing composition, it has a silicon content of 19% to 38% (by weight), preferably 26% to 38% (by weight), more preferably 34% to 38% (by weight); and/or - Based on the total weight of the polydimethylsiloxane-containing composition, it comprises less than 50% (by weight), preferably less than 25% (by weight), more preferably less than 5% (by weight), of fillers.
The use according to claim 12, wherein the recycled cyclic polydimethylsiloxane has a carbon footprint of less than 4 kg CO2 equivalents/kg or preferably less than 2 kg CO2 equivalents/kg of the recycled cyclic polydimethylsiloxane, as determined in accordance with DIN EN ISO standard 14067:2018.
Use of at least one polyether polydimethylsiloxane obtained by the method described in any one of claims 1 to 8 as an additive in a method for producing a polymer foam or a composition for preparing a polymer foam, wherein the polymer foam is preferably a polyurethane foam, a phenolic resin foam, or a polyvinyl chloride foam, and more preferably a polyurethane foam.

Description

This invention relates to polyether polydimethylsiloxanes that can be used as stabilizers for polymer foams such as polyurethane foams. It is known that polyether polydimethylsiloxanes can be produced based on compounds derived from recycled polydimethylsiloxanes. Therefore, a method for producing polyether polydimethylsiloxanes based on cyclic polydimethylsiloxanes derived from linear or branched polydimethylsiloxanes or their copolymers is provided. This invention also relates to methods and compositions for preparing polymer foams using polyether polydimethylsiloxanes, and articles produced thereby. Furthermore, this invention relates to the use of cyclic polydimethylsiloxane-containing compositions and the use of polyether polydimethylsiloxanes thus obtained as foam stabilizers. Technical Background: Foam stabilizers are typically used to ensure the formation of stable foams. These compounds ensure that gases produced during the reaction do not leak from the reaction mixture and that the resulting foam remains stable until the reaction is complete, preventing collapse. Typical polymer foams are polyurethane foams, phenolic resin foams, or polyvinyl chloride foams. Frequently used foam stabilizers are selected from polyether polydimethylsiloxanes. Therefore, suitable starting materials for the production of polyether polydimethylsiloxanes are generally cyclic polydimethylsiloxanes, preferably octamethylcyclotetrasiloxanes. High-purity cyclic polydimethylsiloxanes are typically obtained from chlorosilanes in the Mueller-Rochow process (hereinafter abbreviated as MR or MR process), followed by hydrolysis. The Mueller-Rochow process is the most common process for preparing organosilicon compounds on an industrial scale directly from natural silicon sources such as sand. In the Mueller-Rochow process, alkyl chlorides react with elemental silicon in a fluidized bed reactor. Unfortunately, the production of cyclic polydimethylsiloxanes by the Mueller-Rochow process requires a wasteful amount of energy. Therefore, it is desirable to reduce the carbon footprint of the manufacturing process and the polyether polydimethylsiloxane foam stabilizers thus produced, and to provide alternative methods for their preparation. On the other hand, the accumulation of large amounts of plastic waste is one of the global challenges currently facing the world. Indeed, the serious environmental risks of landfills or the incineration of plastic waste are a growing global concern. Under these conditions, the recycling of polymers such as polydimethylsiloxane (also abbreviated herein as PDMS) is essential for the polymer industry's transition to carbon neutrality. Consequently, polydimethylsiloxane is widely used in industry, for example, in sealants, adhesives, lubricants, cookware, and equipment for medical applications, thermal insulation, and electrical insulation. Various recycling methods for polydimethylsiloxanes are known. For example, European Patent Application Publication No. 0009202 discloses that waste materials containing polyorganylsiloxanes can be recycled by catalytic depolymerization. For this purpose, a composition of a linear or branched organopolysiloxane comprising at least 50 mol% dimethylsiloxane units and aqueous sulfuric acid as a catalyst to promote the rearrangement of siloxane bonds is heated to obtain a cyclic dimethylpolysiloxane-containing composition. Furthermore, U.S. Patent No. 5,110,972 relates to the recycling of waste silicone by dissolving the silicone in a suitable solvent and converting it to a cyclic siloxane by applying a two-step acid/base catalytic cracking process. Thus, the silicone waste consists of high molecular weight liquid or elastomer materials typically formed by silicone polymers having short alkyl groups, particularly methyl groups. The cyclic siloxane-containing composition is ultimately obtained in high yield by distillation. Canadian Patent Application Publication No. 2737235 discloses a first step in the production of a hydrogen polysiloxane, comprising reacting decamethylcyclopentasiloxane (D5), poly(methyl)hydrogensiloxane and hexamethyldisiloxane HMDS using a pre-dried ion-exchange resin. The resulting polyhydrogen-dimethylsiloxane is then reacted with a polyether of the central formula CH₂ = CH- CH₂O- ( C₂H₄O- ) ₅ ( C₃H₆O ) ₂CH₃ having a platinum metal complex to form a block polysiloxane-polyoxyalkylene, which is used as a stabilizer for flexible polyurethane foams. U.S. Patent Application Publication No. 2006/241270 discloses a first step in the production of a hydrogen siloxane, comprising reacting a mixture of decamethylcyclopentasiloxane (D5), poly(methyl)hydrogen-siloxane PTF1, and hexamethyldisiloxane HMDS using a pre-dried ion-exchange resin. The hydrogen siloxane thus obtained is then further reacted with polyethers of various average formulas to obtain a polysiloxane (polyoxyalkylene block copolymer). As detailed above, cyclic polydimethylsiloxanes are starti