DD298404A5 - PROCESS FOR THE PREPARATION OF SILOXYANL-ALKENDIYL-BIS (METH) ACRYLATES - Google Patents

Abstract

The invention relates to the preparation of siloxanyl-alkendiyl-bis (meth) acrylates, which are suitable as an intermediate for organic synthesis and as a surfactant. According to the invention, the preparation is carried out in such a way that alk-2-yn-di (meth) acrylate-1,4 and an Si-H-containing organosilyl, organosiloxanyl or polyorganosiloxanyl compound in the equimolar molar ratio catalytically and in the presence of a polymerization inhibitor under normal pressure and in a protective gas atmosphere at a reaction temperature between 80 and 110 C. [Siloxanyl-alkendiyl-bis (meth) acrylate; Si-H group; Organosilylverbindung; Organosiloxanylverbindung; Catalyst; polymerization inhibitor; surfactant}

Description

"C-CR'a-OR"

in which R 'and R "are as defined in formula I, and an Si-H group-containing organosilicon compound of the general formula III,

(Si) -H III

in the (Si) has the meaning given in the general formula, in an equimolar molar ratio is less in the presence of a Hydrosiylierungskataiysators in concentrations of 10 ^-2 to 10 ^-8 mol per mol of triple bond and a polymerization inhibitor at concentrations between 0.01 and 2.0% Normal pressure and in a protective gas atmosphere at a reaction temperature between 80 and 110 ⁰ C to be implemented.

2. The method according to claim characterized in that the hydrosilylation a hydrosilation promoting transition metal compound, such as platinum compounds, is used.

3. The method according to claim 1 and 2, characterized in that is used as the hydrosilylation hexachloroplatinic acid in a concentration of 10 ~ ⁴ to 10 ~ ⁶ moles per mole of triple bond.

4. The method according to claim 1, characterized in that the concentration of the polymerization inhibitor is preferably 0.05 to 0.2%, based on the total mass of the reaction mixture.

5. The method according to claim 1 and 4, characterized in that are used as polymerization inhibitors phenolic stabilizers such as cresol or hydroquinone derivatives.

6. The method according to claim 1,4 and 5, characterized in that are used as polymerization inhibitors bis (tert.butyl) cresol, 2,5-di-tert.butyl · hydroquinone or the monomethyl ether of hydroquinone.

7. The method according to claim 1 and 4 to 6, characterized in that preferably 2,6-di-tert-butyl-4-methyl-phenyol in a concentration between 0.01 and 0.5%, based on the total mass as polymerization inhibitor the reaction mixture is used.

8. The method according to claim 1, characterized in that the hydrosilation is preferably carried out at a reaction temperature of 100 to 110 ⁰ C.

Field of application of the invention

The invention relates to a process for the preparation of siloxanyl-alkenediyl-bis-methacrylates, which are suitable as an intermediate for organic synthesis and as Tensici.

Characteristic of the known state of the art Specific methods for the preparation of siloxanyl-alkenediyl-bis-di-methacrylates are not described in the patent literature

Service.

It is known that conventional methods of hydrosilation of unsaturated compounds (C.Earborn, R.W. Organomet. Compounds oi the Group IV Elements [1968]) mainly due to the easy polymerizability of Acrylic compounds are not suitable for these. Nonetheless, in various US patents, there are indications of the synthesis and application of (meth) acrylic-functionalized esters Siloxanylverbindungen (US-PS 2793223,2898361,2922806,2922807,4348454), which are mainly based on traditional Hydrosilylation conditions based. Thus, US Pat. No. 4,348,454 describes the preparation of acryloyl-functional silicone polymer by Pt-catalyzed addition

of a dimethyl silicone containing Si-H groups on allyl chloride and subsequent reaction with acrylic acid in the presence of a tertiary amine (NEt ₃ ).

Likewise, according to DE-PS 3222839 and EP 0097333, the preparation of acryioyl-substituted siloxanes by Pt-catalyzed Hydrosilation of allyl alcohol and subsequent esterification with acrylic acid. In fact, there are problems in the synthesis of (meth) acryloyl-substituted siloxanyl compounds according to the above-mentioned. yourself

especially to the hydrosilation of allyl compounds related patents, which in particular from the for this

Implementation of typical side reaction of propene elimination revealed. It is also possible to obtain (meth) dcryloyl-modified siloxanes characterized in that initially unsaturated alcohols with Acrylic acid (derivatives) esterified and the esters formed are subsequently hydrosilylated. For example, EP-PS 0130731 describes the preparation of (meth) acryloyl-functional organosiloxanes by hydrosilation of

β- (allyloxy) ethyl methacrylate with a Si-H siloxane. The well-known in a known manner Pt-catalyzed Si-H addition is surprisingly close to quantitative, but this result is only at strict observance of the upper temperature limit of 80 to 85 ⁰ Cerzielt.

The same patent also refers to the possibility of equivalent synthesis by hydrosilation of Allyl methacrylate with Si-H functional polyorganosiloxane polymers. A disadvantage of this method is that about 30%

the product containing methacrylate groups are easily hydrolyzed, whereby z. B. upon exposure to

Humidity a significant loss of methacryloyl functionality is favored. A further development is the US-PS 3,258,477, in the unwanted polymerization phenomena as far as possible

be avoided. It describes the hydrosilation of allyl methacrylate with trimethoxysilane in toluene and in the presence of 2,5-di-tert-butyl-hydroquinone and hexachloroplatinic acid. The use of large amounts of solvent, however, make these processes very expensive and economically unattractive.

The preparation of siloxanyl-alkendiyl-bls-carboxylates is the subject of DD-PS 255346, after which

(Polylsiloxsnvlsubstituierte alkenyl or disilyl ether equimolar with dicarboxylic acidsAnanhydriden in the presence of a

Esterification, »italysators and optionally inert solvent at temperatures between 90 and 130 ^c implemented C and

subsequently neutralized.

However, the application to siloxanyl-alkendiyl-bis (meth) acrylates as structural analogs is because of the extraordinarily high Polymerization tendency already below the reaction temperature is not possible. Object of the invention

It is the object of the invention to prepare siloxanyl-alkendiyl-bis (meth) acrylates in a simple and economically favorable manner in high purity and with quantitative yield.

Explanation of the essence of the invention

The invention has for its object to develop an easily manageable process for the preparation of siloxanyl-alkendiyl-bis (meth) acrylates, are avoided in the unwanted polymerization reactions or take place only to an insignificant extent

 The object is achieved in that SiIc (anyl-alkendiyl-bis-lmethlacrylate the general formula I

(Si) -C-CRJ-O-R "H-C-CRJ-O-R"

(Si) = organosilyl radicals with alkyl, alkoxy, aryl, aryloxy or the like. Organosiloxanyl radicals having straight-chain, branched and / or cyclic groups and 1 to 20 silicon atoms and alkyl, alkoxy, aryl and / or aryloxy groups mi; 1 to 6 C atoms or straight-chain or branched Oi ganopolysiloxanylreste having 5 to 250 silicon atoms and alkyl, alkoxy, aryl, aryloxy

R '= HoderC, -bisC ₄ alkyl R "-acryloyl or methacryloyl

are prepared according to the invention by alk-2-in-di (meth) acrylate-1,4 of the general formula II,

C-CRVO-R ""

C-CRVO-R "

in which R 'and R "have the meaning given in formula I, and an organosilicon compound containing Si-H groups of the general formula IiI,

(Si) -H III

in which (Si) has the meaning given in the general formula I, in an equimolar ratio in the presence of a hydrosilylation catalyst in concentrations of 1CT ² to 10 ~ ^e moles per mole of triple bond and of a polymerization inhibitor in concentrations between 0.01 and 2.0% lower Normal pressure and in a protective gas atmosphere at a reaction temperature between 80 and UO ⁰ C are reacted. The reaction time is usually in the range of 2 to 5 hours.

Suitable catalysts for the hydrosilation are any, the Si-H addition promoting transition metal compounds, such as. B. platinum catalysts. Preferably hexachloroplatinic acid in amounts of 10 ~ ⁴ to 10 ⁶ mol per mol of triple bond used ~. Suitable polymerization inhibitors are phenolic stabilizers, such as cresol or hydroquinone derivatives, for example bis (tert-butyl) cresol, 2,5-di-tert-butyl-hydroquinone or the monomethyl ether of hydroquinone, preferably 2,6-di-tert. butyl-4-methyl-phenol, in a concentration between 0.01 and 0.5%, preferably between 0.05 and 0.2%, based on the total mass of the reaction mixture, can be used.

The H / drosilylation can be carried out by first heating the di (meth) acrylate added with the catalyst and the stabilizer to about 30 ° C and then adding the Si-H compound with further heating to 110 ° C becomes. According to the invention, the reaction is carried out without the presence of a solvent, the use of an appropriate for the hydrosilation inert organic solvent such. As toluene, but, especially if the reaction mixture - especially in reactions involving polyorganosiloxanyl - is highly viscous, may be advantageous.

The present invention is characterized in particular by the fact that in a very simple process under mild reaction conditions (low temperature, atmospheric pressure) and at the same time very short reaction time siloxanyl-alkenediyl bis (meth) acrylates both in high purity, as well as in almost quantitative yield be synthesized.

embodiments example 1 Preparation of 2-heptamethyltrisiloxanyl-but-2-ene-dimethacrylate-1.4 A mixture consisting of 5g (0.0225mol) but-2-yne-dimethacrylate-1.4,01g of 2,6-di-tert-butyl-4-methyl-phenol (0.1%) and

0.05 ml of a 0.1 molar isopropanolic Hexachloroplatinsäurelösung, stirring, reflux and in

Inert gas atmosphere heated to about 30 ⁰ C. To the now liquid substance mixture with further heating until

At 110 ° C 5 g (0.0225 mol) of heptamethyltrisiloxane slowly added dropwise. The mixture is stirred for 2 hours at this temperature and the orange-yellow solution filtered to remove any polymerized but-2-in-dimethacrylate-1,4 (4,7mg). There remain 9.0 g of 2-heptamethyltrisiloxanyl-but-2-ene-dimethacrylate-1,4.

Yield: 90% of theory.

Sdp. _O , ooi: 110 ° C

GC purity: 98.7% Example 2 Preparation of 2-heptamethyltrisiloxanyl-but-2-ene-dimethacrylate-1,4

10 g (0.045 mol) of but-2-yn-dimethacrylate 1.4.0.05 g of 2,6-di-tert-butyl-4-methyl-phenol (0.25%), 0.1 ml of the platinum catalyst are dissolved in 50 ml of toluene and reacted in analogy to Example 1 with 10 g (0.045 mol) heptamethyltrisiloxane, wherein a

Reaction temperature of 8O ⁰ C is maintained. After Sstündiger reaction time, the solvent is separated by distillation,

and 16.5 g of 2-heptamethyltrisiloxanyl-but-2-ene-dimethacrylamide M, 4 remain.

Yield: 83% of theory Example 3 Preparation of a Polorganosiloxanyl-but-2-ene-dimethacrylate-1,4

3g (0.0135 mol) of but-2-yne-dimethacrylate-1.4 dissolved in 35ml toluene, 0.026g 2,6-di-tert-butyl-4-methylphenol (0.26%) and 0.05ml hexachloroplatinic acid solution are hydrosilylated as described in Example 1 with 6.8 g of a polysiloxane having an average molecular weight of M = 3000 and an Si-H content of 0.2%. After distillative removal of the solvent, 8.0 g of a yellow highly viscous product were obtained, which was identified as the target compound by C-NMR spectroscopy Yield: 81.6% of theory

¹³ C-NMR: δοο = 166.44 ppm

Sch = 136.76 ppm.

Claims (1)

1. A process for the preparation of 8iloxanyl-alkendiyl-bis (meth) acryla ⁽ .en of the general formula I. (SiHJ-CrV ₂ -OR "! H-C-O-R-CR'R " (Si) = organosilyl radicals having alkyl, alkoxy, aryl, aryloxy groups or organosiloxanyl radicals having straight-chain, branched and / or cyclic groups and 1 to 20 silicon atoms and alkyl, alkoxy, aryl and / or aryloxy groups having 1 to 6 C atoms or straight-chain or branched organopolysiloxanyl radicals having 5 to 250 silicon atoms and also alkyl, alkoxy, aryl, aryloxy groups, R '= H od'jr C ₁ - to C ₄ -A! Kylrest R "= acryloyl or methacryloyl characterized in that alk-2-yn-di (meth) acrylate-1,4 of general formula II,