DE1140711B - Process for the purification of liquid phenylmethylpolysiloxanes from added silicon-free aromatic compounds by distillation - Google Patents
Process for the purification of liquid phenylmethylpolysiloxanes from added silicon-free aromatic compounds by distillationInfo
- Publication number
- DE1140711B DE1140711B DEF30884A DEF0030884A DE1140711B DE 1140711 B DE1140711 B DE 1140711B DE F30884 A DEF30884 A DE F30884A DE F0030884 A DEF0030884 A DE F0030884A DE 1140711 B DE1140711 B DE 1140711B
- Authority
- DE
- Germany
- Prior art keywords
- distillation
- phenylmethylpolysiloxanes
- aromatic compounds
- purification
- liquid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic System
- C07F7/02—Silicon compounds
- C07F7/08—Compounds having one or more C—Si linkages
- C07F7/20—Purification, separation
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
- C08G77/04—Polysiloxanes
- C08G77/32—Post-polymerisation treatment
- C08G77/34—Purification
Description
Verfahren zur Reinigung flüssiger Phenylmethylpolysiloxane von beigemengten siliciumfreien aromatischen Verbindungen durch Destillation Bei der Synthese von Phenylchlorsilanen aus Silicium und Chlorbenzol entstehen in geringen Mengen aromatische Nebenprodukte, wie Diphenyl und seine Chlorderivate, die bei der nachfolgenden Hydrolyse und Kondensation zu phenylsubstituierten Polysiloxanen, beispielsweise Phenylmethylpolysiloxanen, von diesen aufgenommen werden, so daß ihnen ein unangenehmer Geruch anhaftet. Process for the purification of liquid phenylmethylpolysiloxanes from admixed silicon-free aromatic compounds by distillation in the synthesis of Phenylchlorosilanes from silicon and chlorobenzene are produced in small quantities, aromatic By-products, such as diphenyl and its chlorine derivatives, that result from the subsequent hydrolysis and condensation to phenyl-substituted polysiloxanes, for example phenylmethylpolysiloxanes, are absorbed by these, so that they have an unpleasant odor attached.
Um aus niederpolymeren Organosiloxanen, deren Siedepunkte nahe denen ihrer vorerwähnten Verunreinigungen liegen, solche zu entfernen, kann man gemäß einem nicht zum Stande der Technik gehörenden Vorschlag ein Extraktionsverfahren unter Zuhilfenahme von mehrwertigen Alkoholen, Aminoalkoholen oder Aminen benutzen. Ein solches Verfahren hat zwar den Vorteil, bei hinreichend niedriger Temperatur auch auf wärmeempfindliche Siloxane anwendbar zu sein, doch sind die Extraktionsmittel ihrerseits auch nicht geruchlos und erfordern somit einen besonderen Aufwand sowohl zu ihrer Entfernung als auch zu ihrer Rückgewinnung zwecks Wiederverwendung. To be made from low polymer organosiloxanes whose boiling points are close to those their above-mentioned impurities lie, such can be removed according to a non-prior art proposal an extraction process Use with the help of polyhydric alcohols, amino alcohols or amines. Such a process has the advantage of being at a sufficiently low temperature to be applicable to heat-sensitive siloxanes as well, yet the extractants are for their part also not odorless and thus require a special effort both for their removal as well as for their recovery for reuse.
Es wurde nun gefunden, daß eine wesentlich einfachere Reinigung flüssiger Phenylmethylpolysiloxane von beigemengten siliciumfreien aromatischen Verbindungen durch Destillation erfolgen kann, wobei man die Destillation nach Zumischen eines aus einem zweiwertigen Alkohol oder Ätheralkohol bestehenden Schleppmittels durchführt, bis das dabei hinterbleibende Phenylmethylpolysiloxan sowohl von den ursprünglichen Beimengungen als auch von dem Schleppmittel im wesentlichen befreit ist. Als Schleppmittel dienen Äthylen-, Propylen-, Diäthylen- oder Dipropylenglykole. It has now been found that a much easier cleaning liquid Phenylmethylpolysiloxanes from admixed silicon-free aromatic compounds can be done by distillation, the distillation after admixing one carries out entrainer consisting of a dihydric alcohol or ether alcohol, until the remaining phenylmethylpolysiloxane both from the original Admixtures as well as the entrainer is essentially freed. As a drag agent Ethylene, propylene, diethylene or dipropylene glycols are used.
Beispiel 1 kg eines polymerhomologen Gemisches von niederpolymeren Phenylmethylsiloxanen, dessen Viskosität bei 20"C 20 cSt und in welchem das Phenyl-Methyl-Verhältnis 1: 5 beträgt, wird mit 1 kg Diäthylenglykol vermischt und bei einem Druck von 15 Torr und Temperaturen bis 135"C so lange destilliert, bis die eingesetzte Menge an Diäthylenglykol in das Destillat übergegangen ist. Example 1 kg of a homologous polymer mixture of low polymers Phenylmethylsiloxanes, their viscosity at 20 "C 20 cSt and in which the phenyl-methyl ratio 1: 5 is mixed with 1 kg of diethylene glycol and at a pressure of 15 Torr and temperatures up to 135 "C distilled until the amount used of diethylene glycol has passed into the distillate.
Der Rückstand wird dann nach hier nicht beanspruchtem Verfahren zweimal mit der. Hälfte seines Volumens an gesättigter Kochsalzlösung gewaschen und durch eine aus wasserfreiem Calciumchlorid und Aktivkohle gemischte Schicht filtriert. The residue is then processed twice using a method not claimed here with the. Half of its volume in saturated saline and washed through a layer mixed with anhydrous calcium chloride and activated carbon is filtered.
Das Filtrat ist farb- und geruchlos und enthält weniger als 0,5 Gewichtsprozent Chlor in Form von aromatischen Chlorkohlenwasserstoffen gegenüber 4 Gewichtsprozent im eingesetzten Rohsiloxan.The filtrate is colorless and odorless and contains less than 0.5 percent by weight Chlorine in the form of aromatic chlorinated hydrocarbons compared to 4 percent by weight in the raw siloxane used.
Das Destillat scheidet sich in zwei Schichten, deren untere das Diäthylenglykol und einen Teil der aromatischen Chlorwasserstoffe enthält; der übrige Teil bildet zusammen mit etwa 300/0 des zur Destillation eingesetzten Phenylmethylpolysiloxans die obere Schicht. The distillate separates into two layers, the lower one the diethylene glycol and contains part of the aromatic hydrochloric acid; the remaining part forms together with about 300/0 of the phenylmethylpolysiloxane used for the distillation the top layer.
Letztere wird mit frischem Rohprodukt erneut in das Reinigungsverfahren zurückgeführt. Die untere Schicht wird mit einem Viertel ihres Volumens an Wasser verrührt, wonach sie von neuem zwei Schichten bildet, deren untere aus den Aromaten besteht und verworfen wird. Das darauf schwimmende Diäthylenglykol wird durch Destillation von dem zugemischten Wasser befreit und- im weiteren Verfahren wieder verwendet. The latter is put back into the cleaning process with fresh raw product returned. The bottom layer gets a quarter of its volume in water after which it forms two layers again, the lower one consisting of the aromatics exists and is discarded. The floating diethylene glycol is made by distillation freed from the added water and reused in the further process.
Wendet man an Stelle des Diäthylenglykols Propylenglykol an und verfährt im übrigen analog, so erhält man ebenfalls ein gut gereinigtes Produkt, doch gehen bei der Destillation größere Anteile an Phenylmethylpolysiloxane über. If you use propylene glycol instead of diethylene glycol and proceed otherwise analogous, so you also get a well-cleaned product, but go larger proportions of phenylmethylpolysiloxanes in the distillation.
Bei Anwendung von Äthylenglykol an Stelle des Diäthylenglykols ist dies zwar nicht der Fall, aber es bleibt etwas mehr an Verunreinigungen im Destillationsrückstand. When using ethylene glycol instead of diethylene glycol this is not the case, but a little more impurities remain in the distillation residue.
Claims (2)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEF30884A DE1140711B (en) | 1960-03-31 | 1960-03-31 | Process for the purification of liquid phenylmethylpolysiloxanes from added silicon-free aromatic compounds by distillation |
GB814361A GB907066A (en) | 1960-03-31 | 1961-03-06 | Process for the removal of aromatic impurities from liquid phenyl methyl polysiloxanes |
BE601696A BE601696A (en) | 1960-03-31 | 1961-03-23 | Process for removing aromatic impurities in phenylmethylpolysiloxanes |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEF30884A DE1140711B (en) | 1960-03-31 | 1960-03-31 | Process for the purification of liquid phenylmethylpolysiloxanes from added silicon-free aromatic compounds by distillation |
Publications (1)
Publication Number | Publication Date |
---|---|
DE1140711B true DE1140711B (en) | 1962-12-06 |
Family
ID=7093963
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DEF30884A Pending DE1140711B (en) | 1960-03-31 | 1960-03-31 | Process for the purification of liquid phenylmethylpolysiloxanes from added silicon-free aromatic compounds by distillation |
Country Status (3)
Country | Link |
---|---|
BE (1) | BE601696A (en) |
DE (1) | DE1140711B (en) |
GB (1) | GB907066A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5618902A (en) * | 1995-11-03 | 1997-04-08 | General Electric Company | Vapor precipitation of polymers from solvent polymer blends by azeotropic spray drying |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE533847A (en) * | 1953-12-03 | 1958-06-06 | Gen Electric | SILICONE RUBBER SHALL SHRINK ON COMPRESSION. |
-
1960
- 1960-03-31 DE DEF30884A patent/DE1140711B/en active Pending
-
1961
- 1961-03-06 GB GB814361A patent/GB907066A/en not_active Expired
- 1961-03-23 BE BE601696A patent/BE601696A/en unknown
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE533847A (en) * | 1953-12-03 | 1958-06-06 | Gen Electric | SILICONE RUBBER SHALL SHRINK ON COMPRESSION. |
Also Published As
Publication number | Publication date |
---|---|
BE601696A (en) | 1961-07-17 |
GB907066A (en) | 1962-10-03 |
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