DE4436076A1 - Organo-siloxane(s) useful in polymer prodn. and as polymer compatibiliser - Google Patents

Abstract

Organosiloxanes of formula CH2=CHSiMeR<1>O(SiMe2O)aSiR<2>R<3>R<4> (I), which have a terminal vinyl gp. at one end and another functional gp. at the other end of the chain, are new. In (I), R<1> = 1-4C alkyl or aryl; R<2>, R<3>, R<4> = alkyl, aryl, aminoalkyl, hydroxyalkyl, haloalkyl or alkoxy OR<5> (R<5> = 1-4C alkyl or aryl); a = 3-100. (I) are prepd. by (a) decomposition of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane (III) with Li organyls of formula R<1>Li (IV) to Li silanolates of formula CH2=CHSiMeR<1>OLi (V); (b) anionic polymerisation of hexamethylcyclotrisiloxanes (VI) with (V); and (c) stopping anionic polymerisation with cpds. of formula XSiR<2>R<3>R<4> (VII) (where X = Cl or acetoxy).

Description

The invention relates to organosiloxanes with a terminal vinyl group and another radio located at the other end of the chain tional group, a process for their preparation and their Ver Use as starting compounds for the production of siloxane copoly mer and for hydrosilylation reactions, as a compatibilizer for different polymers and as a modifier for pig elements and fillers to improve their compatibility with or ganic binders and varnishes.

From the prior art, siloxanes with the same groups are in α- and ω position known, e.g. B. α, ω-bis (hydrogen, hydroxyalkyl, -aminoalkyl- and -glycidyloxyalkyl) siloxanes. You are acidic or basic equilibration of the correspondingly functionalized Di siloxanes accessible with cyclic siloxanes.

Organic residues at only one chain end are identified by the so-called Initiator method introduced. So lithium alkyl acetals for the Preparation of siloxanes with hydroxyalkyl end groups (P. M. Lefebv re et al; Macromolecules, 1977, 10, 878) or p-bis (trimethylsilyl amino) phenyl alkyl lithium compounds for the production of silox anenes with aminoaryl end groups (W.H. Dickstein et al; Macromole cules, 1989, 22, 3886).

Siloxanes with an aminoalkyl group and one or more vinyl, Acrylate or mercaptopropyl end groups at the other chain end in U.S. Patent 4,650,849. The examples are however, are only disiloxanes.

Siloxanes with an Si-H and another functional group on other chain ends are described in DE-PS 42 34 898. she are by anionic polymerization of hexamethylcyclotrisil  oxane with hydrogen silanolates and termination of the polymerization with functional chlorine or acetoxysilanes. The be The necessary initiator is obtained by cleavage of tetramethylcyclotetrasi loxane synthesized with lithium organylene. When splitting can undesirable side reactions occur, for example on Si bonded H atoms are replaced by alkyl groups, whereby the SiH content in the siloxane is reduced.

Siloxanes with one alkoxy group and one vinyl group on the other Chain ends are described in DE-PS 42 34 959. The manufacturer development is carried out by anionic polymerization of D₃ with Li alcohol laten and termination of the polymerization with functional chlorine or Acetoxysilanes. In this way, however, no siloxanes can contain several alkoxy groups can be synthesized.

There are therefore no known processes from the art which un symmetrical linear siloxanes with a vinyl group one and another functional group at the other chain end to the subject.

The invention relates to organosiloxanes of the general formula

CH₂ = CHSiMeR¹O (SiMe₂O) _a SiR²R³R⁴ (I)

in which
R¹ represents an alkyl radical with 1 to 4 carbon atoms or an aryl radical,
R², R³ and R⁴ independently of one another the same or different alkyl radicals, aryl radicals, aminoalkyl radicals, hydroxyalkyl radicals, haloalkyl or alkoxy radicals OR⁵, where R⁵ is an alkyl radical with 1 to 4 carbon atoms or an aryl radical, and
a assumes a value from 3 to 100.

The radical R1 can be a methyl, n-butyl, s-butyl, t-butyl or Be phenyl. Methyl and n-butyl radicals are preferred. The Residues R², R³ and R⁴ can be alkyl groups, such as. B. methyl or Alkoxy groups of the general formula OR⁵, where R⁵ is preferably a Is ethyl residue. Values between 3 and 50 are preferred for a.  

Another object of the invention is a method for Preparation of these compounds according to the invention by

• a) in a first stage 1,3,5,7-tetramethyl-1,3,5,7-tetravinyl cyclotetrasiloxane with lithium organylene of the general formula R¹Li to lithium silanolates of the general formula CH₂ = CHSiMeR¹OLi (II) cleaved, then
• b) Hexamethylcyclotrisiloxane with lithium silanolates of the general my formula II anionically polymerized and then
• c) the anionic polymerization is terminated with compounds of the general formula XSiR²R³R⁴ (III) where X is a chlorine radical or an acetoxy radical and
  R², R³ and R⁴ have the meaning already given.

Examples of compounds according to the invention are

CH₂ = CHSiMe₂O (SiMe₂O) ₁₅SiMe (OEt) ₂
CH₂ = CHSiMe₂O (SiMe₂O) ₁₅Si (OEt) ₃
CH₂ = CHSi (C₄H₉) MeO (SiMe₂O) ₁₅SiMe (OEt) ₂

The advantage of the method according to the invention is, among other things in the fact that linear siloxanes with a vinyl group on one and another functional group on the other Chain end can be made.

By choosing the ratio of what is produced according to the invention Lithium silanolate to monomer can have a certain average chain length can be set. The products are highly uniform on.

Another advantage is that there are hardly any by-products and thus no complex cleaning operations are required.

Another object of the invention is the use of Products according to the invention for the production of siloxane copolymers.  

For example, hydroxy or aminoalkyl residues of the siloxanes with acid halo genide or anhydride residues (e.g. maleic anhydride) or Isocya nate groups (e.g. precursors of polyurethane production) from poly be implemented. The vinyl group can be grafted onto poly olefins (e.g. polyethylene) can be used.

The products of the invention are also starting materials for Hydrosilylation reactions. Hydrogen silanes or siloxanes the general formula

H (SiR⁶R⁷O) _b SiR⁸R⁹R¹⁰ (IV)

in which

R⁶, R⁷, R⁸ and R⁹ independently of one another represent alkyl groups, preferably methyl groups,
R¹⁰ is a stabilizer molecule (e.g. HALS or antioxidant molecule), a radical of the general formula (CH₂) ₃X with X = OH, NH₂, Cl or glycidoxy and
b assumes a value from 0 to 100,

be added to vinylsiloxanes.

The products according to the invention can also be used as compatibilizers serve for polymers which are immiscible or only miscible with one another. First, by grafting vinyl siloxanes with a or more alkoxy groups on polyolefins with siloxane copolymers Alkoxy end groups produced. Two polymers modified in this way can now by hydrolysis and subsequent condensation of the alk oxy groups are linked together.

Another possibility of linking two polymers is therein one polymer over the vinyl residue and the second polymer over to bind the radicals R², R³, R⁴ or R¹⁰.

Finally, the products containing alkoxysilyl groups serve as modes fication agent for OH group-containing pigments and fillers, ins special for silicate fillers, to improve their ver inertness with organic binders and paints.  

Embodiments

The process according to the invention is intended to be illustrated by the following examples are explained in more detail.

I. Siloxanes with a vinyl group in α and alkoxy groups in ω position Representation of lithium dimethyl vinyl silanolate CH₂ = CHSiMe₂OLi

5 g (0.0145 mol) of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetra siloxane (D₄ ^vinyl ), dissolved in 20 ml of THF, were added to 39.3 ml of a 1 at room temperature. 48 molar (0.058 mol) solution of methyl lithium in ether was added. The mixture was stirred at room temperature for one hour.

The concentration of the silanolate solution was determined by double titration determined according to Gilman to 0.96 mol / l.

example 1 Representation of α-dimethylvinylsiloxy-ω-diethoxymethylsiloxy polydimethylsiloxanes CH₂ = CHSiMe₂O (SiMe₂O) _n SiMe (OEt) ₂ n = 3, 6, 15

In a three-necked flask with a dropping funnel, reflux condenser and Three-way cocks with septum and gas connection were the ones in Table 1 specified amounts of a 0.96 molar solution of the prepared Lithium dimethyl vinyl silanolates in an ether / THF mixture sets and at 55 ° C 6.66 g (0.03 mol) of hexamethylcyclotrisiloxane (D₃), dissolved in THF, added dropwise.

After 2 hours the polymerization started with that in Table 1 given amounts of diethoxymethylchlorosilane canceled and still stirred for a further 0.5 hours.

The precipitate was filtered off and the solvent was distilled off liert.

The structure of the compounds was confirmed by ²⁹Si NMR spectra.  

Table 1

Example 2 Representation of α-dimethylvinylsiloxy-ω-triethoxysiloxy polydimethylsiloxanes CH₂ = CHSiMe₂O (SiMe₂O) _n Si (OEt) ₃ n = 3, 15, 30

The presentation was carried out analogously to Example 1 with the difference that as abort the amounts of chlorotriethoxy given in Table 2 silane were used.

The structure of the compounds was determined by ²⁹Si NMR spectra approved.

Table 2

II. Siloxanes with a vinyl and a butyl group in α- and Alkoxy groups in the ω position Representation of lithium-butylmethylvinylsilanolates CH₂ = CHSiMeR¹OLi R¹ = n-Bu, s-Bu, t-Bu

Analogous to the production of lithium dimethylvinyl lithium silanolate described above, silanolates were obtained by cleavage of D₄ ^vinyl with 0.058 mol of the solutions of lithium organyls given in table 3 in various solvents, which were suitable for the anionic polymerization of D₃.

The concentration of the silanolate solution was determined by double titration determined according to Gilman to 1.05 mol / l.

Table 3

Example 3 Representation of α-butylmethylvinylsiloxy-ω-diethoxymethylsiloxy polydimethylsiloxanes and of α-butylmethylvinylsiloxy-ω-triethoxy siloxy-polydimethylsiloxanes CH₂ = CHSiMeR¹O (SiMe₂O) _n SiMe _i (OEt) _3-i R¹ = as above, i = 0 to 3

The representation was carried out analogously to Examples 1 or 2 with the sub decided that the amounts of 1.05 molar solution given in Table 4 gene of lithium butyl methyl vinyl silanolates used as initiators were.

The structure of the compounds was confirmed by ²⁹Si NMR spectra.  

Table 4

Claims (5)

1. Organosiloxanes with a terminal vinyl group and another functional group located at the other chain end of the general formula CH₂ = CHSiMeR¹O (SiMe₂O) _a SiR²R³R⁴ (I) where
R¹ represents an alkyl radical with 1 to 4 carbon atoms or an aryl radical,
R², R³ and R⁴ independently of one another the same or different alkyl radicals, aryl radicals, aminoalkyl radicals, hydroxyalkyl radicals, halogen alkyl, or alkoxy radicals OR⁵, where R⁵ is an alkyl radical having 1 to 4 carbon atoms or an aryl radical, and
a takes a value between 3 and 100. 2. A process for the preparation of the compounds of claim 1, characterized in that

• a) 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane with lithium organyls of the general formula R¹Li to lithium silanoates of the general formula CH₂ = CHSiMeR¹OLi (II) cleaved, then
• b) Hexamethylcyclotrisiloxane anionically polymerized with lithium silanolates of the general formula II and then
• c) the anionic polymerization is terminated with compounds of the general formula XSiR²R³R⁴ (III) wherein
  X is a chlorine residue or an acetoxy residue and
  R², R³ and R⁴ have the meaning already given.

3. Use of the compounds of claim 1 as a starting material for the addition of hydrogen silanes or siloxanes of the general formula H (SiR⁶R⁷O) _b SiR⁸R⁹R¹⁰ (IV) wherein
R⁶, R⁷, R⁸ and R⁹ independently represent alkyl groups, preferably methyl groups,
R¹⁰ is a stabilizer molecule (e.g. HALS or antioxidant molecule), a radical of the general formula (CH₂) ₃X with X = OH, NH₂, Cl or glycidoxy and
b takes a value between 0 and 100,
on vinyl siloxanes. 4. Use of the compounds of claim 1 as a compatibilizer for polymers which are immiscible or only miscible with one another. 5. Use of the alkoxysilyl group-containing compounds of Claim 1 as a modifier for pigments and fillers to improve their compatibility with organic binders and paints.