DE4234959C1 - Polysiloxane(s) with alkoxy gp. at one end and another gp. at the other - by anionic polymerisation of hexa:methyl:cyclo:tri:siloxane with lithium alcoholate, and addn of a functional silane chain-stopper - Google Patents

Abstract

The organopolysiloxanes are of formula (I); wherein R1 = opt. branched alkyl; R2, R3 = 1-4C alkyl or aryl; R4 = a gp. of formula -CH=CH2, -CH2CH2-Phe-CH2Cl, -(CH2)10COOME, -CH2CH2-(3,4-epoxycyclohexyl), -(CH2)3-O-glycidyl or -(CH2)mR5 (with Phe = 1,4-phenylene; R5 = OH, NH2 or Cl, opt. with H atom(s) in OH and NH2 replaced by SiMe3; m = 1-10); and a = 6-100. Also claimed is a process for the prodn. of (I), comprising (1) anionic polymerisation of hexamethhylcyclotrisiloxane (HMCT) with a Li alcoholate of formula R1OLi (II), (2) stopping polymerisation with cpds.of formula XSiR2R3R6 (III) (with X = Cl, Br or acyloxy; R6 = as for R4 above) and opt. (3) cleavage of Me3Si gps. by alcoholysis or hydrolysis. USE/ADVANTAGE - Used as compatibilisers for polymers with little on no mutual miscibility, and as modifiers for pigments and fillers, to improve compatibility with organic binders and paints (claimed).

Description

The invention relates to organopolysiloxanes with a terminal alk oxy group and another radio located at the other end of the chain tional group and processes for their preparation and their Ver Use as a compatibilizer for each other not or only to a limited extent miscible polymers and as modifiers for pigments and fillers substances to improve their compatibility with organic bandages agents and paints.

Functional siloxanes with the same are from the prior art Groups known in the α, ω position. So z. B. α, ω-bis (hydrogen, -hydroxyalkyl-, -aminoalkyl- and -glycidyloxyalkyl) siloxanes ben. The representation is made by acidic or basic equilibration the correspondingly functionalized disiloxanes with cyclic sil oxanes. Another manufacturing option is after EP-PS 0 400 613 the addition of α, ω-dihydrogensiloxanes to unge saturated organic compounds. Both functional groups of the Siloxanes react in the same way and application confines itself to reacting with other difunctional ver bonds to build linear polymers or functional polymers network. The disadvantage is that polymers with different funk tional groups cannot be linked.

In the latter addition process, monohydrogensil When oxanes are used, siloxanes with only one functional result  Group. So Monohydrogensiloxane u. a. according to the DE-OS 40 10 153 and JP-OS 62.195 389 to special unsaturated Hy droxyalkyl compounds and according to US Pat. No. 5,025,074 to 4-acet oxystyrene and according to JP-PS 02.250 887 on 2-allylphenol added.

Organic residues at only one chain end were also removed by the so-called called initiator method introduced. So lithium alkyl acetals for Hydroxyalkyl end group siloxanes (P.M. Lefebvre, R. Jerome, Ph. Teyssie; Macromolecules, 1977, 10, 871) or p-bis (trimethyl silylamino) phenyl alkyl lithium compounds for the production of sil oxanes with aminoaryl end groups (W.H. Dickstein, C.P. Lillya; Macromolecules, 1989, 22, 3886). These synthesis variants are limited to a few functional groups, however, and the Her position of the functional initiators is complex.

In addition, ω-functional siloxanes can be produced by that cyclic siloxanes polymerize anionically and the polymerization is broken off with functional silanes. In JP-PS 02.281042 and 02.294333, for example, the termination with trimethylsilyl-4- (dimethylchlorosilyl) butanoate. With the latter However, the disadvantage of methods is that a chain end of the siloxane is not is reactive.

In EP-OS 0 430 216 branched polysiloxanes with several Aminoalkyl groups described. However, this is almost out of the question finally, disiloxanes. For example, according to the EP-OSen 0 420 031 and 0 420 032 by basic equilibration of 1,3-divinyl tetramethyldisiloxane with 1,3-bis-γ-aminopropyltetramethyldisiloxane 1-γ-aminopropyl-3-vinyltetramethyldisiloxane prepared. The ge Desired product was removed from the equilibration mixture by frak tioned distillation isolated with only 50% yield. Furthermore is this procedure because of the necessary distillative cleaning step limited to very short siloxane chains.

U.S. Patent 4,650,849 et al. a. Siloxanes with an aminoalkyl group on a chain end and one or more vinyl, acrylate or mer  captopropyl groups at the other end of the chain. Here too it is only disiloxanes. Siloxanes with an alkoxy, Thiol and alkylamino or thiol group at the other end of the chain in U.S. Patent 4,992,512. According to this procedure, however only alkoxysiloxanes with vinyl end groups accessible.

Siloxanes with alkoxy groups have also been synthesized by oligomerizing Cy clotrisiloxanes with alkoxysilanes (B. G. Zavin, A.A. Zhdanov, M. Scibiorek, J. Chojnowski; Eur. Polym. J. 1985, 21, 135). This method can be according to DE-PS 23 35 118 functional groups such as γ- (meth acryloyloxy) propyl groups. But here arise always mixtures and no defined asymmetrically structured siloxanes.

In EP 362 710 siloxanes with the same or different unsaturated groups at the chain ends or with an unsaturated group on one side and a silanol group on the other te of the chain described. In the latter case, the introduction of a another functional group by condensation with the silanol group possible, but not described in the examples. The making he follows in that a functional chlorosilane in the corresponding Silanol and then converted to silanolate. After done Polymerization is carried out with acetic acid or with a chlorosilane, which bears an unsaturated group. During the silanolbil In turn, condensation reactions can occur.

There are therefore no known processes from the prior art che asymmetrically constructed, linear siloxanes with an alkoxy group at one and another functional group at the other chain end to the subject.

The present invention therefore relates to organopolysiloxanes with a terminal alkoxy group and one at the other chain end  located further functional group of the general sleek formula

in which
R ^{1 is} a straight-chain or branched alkyl radical, R ² and R ^{3 are} the same or different in the molecule and are an alkyl radical with 1 to 4 carbon atoms or an aryl radical,

in which R ^{5 is} an -OH, -NH ₂ - or -Cl radical, where the hydrogen atom of the radical OH or one or both hydrogen atoms of the radical NH _{2 can be} replaced by a trimethylsilyl radical and
m has a value from 1 to 10,
a has a value from 7 to 100.

R ¹ is a methyl, ethyl, propyl or butyl radical. The methyl radical is preferred.

The radicals R ² and R ³ can have different meanings in the same molecule. They are methyl, ethyl, propyl or butyl, but preferably also methyl. However, each of these radicals can also be an aryl radical, preferably a phenyl radical.

m preferably has a value from 3 to 6.

a has a value of 7 to 100, preferably 7 to 50. Here, a is as to understand an average value for the average molecule.

Examples of compounds according to the invention are

The invention further relates to a process for the preparation of these compounds according to the invention, in which
1.) Anionically polymerized hexamethylcyclotrisiloxane with a lithium alcoholate of the formula R ¹ OLi, then
2.1.) The anionic polymerization with compounds of the general formula

XSiR ² R ³ R ⁶ II

in which
X is a -Cl-, -Br- or acyloxy radical,
R ^{6 has} the meaning of the radical R ⁴ , but the hydrogen atom of the radical OH or one or both hydrogen atoms of the radical NH _{2 can be} replaced by a trimethylsilyl radical, breaks off and, if appropriate,
3.1.) Cleaves the trimethylsilyl group (s) by alcoholysis or hydrolysis.
X is preferably a chlorine or acetoxy radical.
n has a value from 0 to 8, preferably a value of 1.

The advantage of the method according to the invention is u. a. in that uniquely linear siloxanes with an alkoxy group on one and another functional group at the other end of the chain can be put.

By choosing the ratio of initiator to monomer, one can certain average chain length can be set. The products show good uniformity.

Another advantage is that there are no by-products and therefore no complex cleaning operations are necessary.

Another object of the invention is the use of Products according to the invention for the production of siloxane copolymers. So can hydroxy or aminoalkyl residues of the siloxanes with acid halide or anhydride residues (e.g. maleic anhydride) or isocyanate groups (e.g. precursors of PU production) are implemented by polymers. Siloxanes containing epoxy groups can be treated with hydroxy (e.g. polyols), ami No or acid residues of polymers react. Hydrogen siloxanes can added to unsaturated groups of a polymer (e.g. polybutadiene) and Vinylsiloxanes are grafted onto polyolefins (e.g. PE).  

The products of the invention can also be used as a compatibilizer for polymers which are immiscible or only miscible with one another. First, copolymers with alkoxy groups at the end of the siloxane chain are produced by reaction of the polymer with the radical R ^{4 of} the siloxane. Two such modified polymers can now be linked together by hydrolysis and subsequent condensation of the alkoxy groups.

Another possibility of linking two polymers is to bind one polymer via the radical R ⁴ and the second polymer by reaction with the alkoxy group of the siloxane. The latter leads to a SiOC link.

Finally, the products serve as modifiers for OH-grup Pen-containing pigments and fillers, especially silicate fillers substances to improve their compatibility with organic bandages agents and paints.

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

example 1 Preparation of oligomeric α-ethoxy-ω-hydroxypropylsiloxanes Representation of lithium ethylate

8.3 g (1.2 mol) are added to 27.6 g (0.6 mol) of ethanol in 400 ml of ether cut lithium sheet or wire. After reaction on is stirred for a further 2.5 hours with gentle warming, from excess lithium separated and the solution by a third tight.

A concentration of 0.5 mol / l is obtained using Gilman titration Right.

Preparation of α-ethoxy-ω-hydroxypropylsiloxanes

EtO (SiMe ₂ O) _n SiMe ₂ CH ₂ CH ₂ CH ₂ OH n = 15, 30, 45.

The amounts given in Table 1 of a 0.5 molar solution of lithium ethylate in ether are placed in a two-necked flask with dropping funnel and three-way cock with gas connection and septum, and 22.2 g (0.1 mol) of hexamethylcyclotrisiloxane (D ₃ ) at 45 ° C. , dissolved in 50 ml of tetrahydrofuran (THF), added dropwise.

After 1.5 hours, the polymerization is given in Table 1 the amounts of acetoxydimethyl (3-trimethylsiloxypropyl) silane 4 broken. To completely precipitate the lithium acetate, 70 ml Hexane added. The precipitate is fritted and the solvents are distilled off.

To remove the trimethylsilyl protective group, the siloxane is again dissolved in THF and with 10 ml of ethanol and catalytic amounts of OK 80 (acidic ion exchanger) added. The mixture is at 2.5 hours Room temperature left, then filtered off from OK 80 and volatile products deducted.  

The structure of the compounds is verified using ²⁹ Si NMR spectra.

Table 1

Example 2 Preparation of oligomeric α-isopropoxy-ω-hydroxypropylsiloxanes Preparation of lithium isopropylate

3.5 g (0.5 mol) of cut lithium sheet or wire are in 100 ml of THF are introduced and 24 g (0.4 mol) of isopropanol are added dropwise. To reaction is stirred for 1 hour, filtered and a concentration of 2.9 mol / l was determined by means of Gilman titration.

Preparation of α-isopropoxy-ω-hydroxypropylsiloxanes

iPrO (SiMe ₂ O) _n CH ₂ CH ₂ CH ₂ OH
n = 15, 30, 45.

The representation is carried out analogously to Example 1 using the in Amounts given in Table 2 of a 2.9 molar solution of lithium iso propylate in THF.

The structure of the compounds is verified using ²⁹ Si NMR spectra.

Table 2

Example 3 Preparation of α-ethoxy and α-isopropoxy-ω-allylsiloxanes

RO (SiMe₂O) _n SiMe₂CH₂CH = CH₂

R = Et, iPr
n = 15, 30, 45

The preparation is carried out analogously to Example 1 or 2. The amounts of allyl chlorodimethylsilane 5 given in Table 3 are used to terminate the polymerization. The structure of the compounds is confirmed by ²⁹ Si NMR spectra.

Table 3

Example 4 Representation of α-ethoxy and α-isopropoxy-ω-vinyl siloxanes

RO (SiMe₂O) _n SiMe₂CH = CH₂

R = Et, iPr
n = 15, 30, 45

The representation is analogous to example 1 or 2. As a terminator the amounts of chlorodimethylvinylsi given in Table 4 Lan 7 used.

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

Table 4

Example 5 Preparation of α-ethoxy-ω-aminopropylsiloxanes

RO (SiMe₂O) _n SiMe₂CH₂CH₂CH₂NH₂

R = Et, iPr
n = 15, 30, 45

7.2 g (0.04 mol) of bis (trimethylsilyl) allylamine made by Um Settlement of allylamine with trimethylchlorosilane in chloroform in a molver ratio 3: 2, together with 20 µl PtK in a flask with In thermometer, reflux condenser, magnetic stirrer and gas inlet pipe submitted. At a temperature of 40 ° C 10 g (0.008 mol) of α-Hy drug-ω-ethoxysiloxane with n = 18 added dropwise and at 110 ° C. for 6 hours warmed up.  

Then excess silylated allylamine and volatile Be components removed in a vacuum.

10 ml of ethanol are added to remove the trimethylsilyl protective group set and left for a day at room temperature. After that Excess ethanol and the resulting ethoxytrimethylsilane abge pulled.

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

Example 6 Preparation of α-ethoxy-ω-glycidyloxypropylsiloxanes

The preparation is carried out analogously to Example 6 with 4.6 g (0.04 mol) of Al lylglycidether.

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

Example 7 Preparation of α-ethoxy-ω-glycidyloxypropylsiloxanes

The preparation is carried out analogously to Example 6 with 4.6 g (0.04 mol) of Al lylglycidether.

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

Claims (4)

1. Organopolysiloxanes with a terminal alkoxy group and another functional group of the general average formula located at the other chain end in which
R ^{1 means} a straight-chain or branched alkyl radical,
R ² and R ^{3 are} the same or different in the molecule and represent an alkyl radical having 1 to 4 carbon atoms or an aryl radical, in which R ^{5 is} an -OH, -NH ₂ - or -Cl radical, where the hydrogen atom of the radical OH or one or both hydrogen atoms of the radical NH _{2 can be} replaced by a trimethylsilyl radical and
m has a value from 1 to 10,
a has a value from 7 to 100. 2. Process for the preparation of the compounds of claim 1, characterized in that
1.) Anionically polymerized hexamethylcyclotrisiloxane with a lithium alcoholate of the formula R ¹ OLi, then
2.1.) The anionic polymerization with compounds of the general formula XSiR ² R ³ R ⁶
X is a -Cl, -Br or acyloxy radical,
R ^{6 has} the meaning of the radical R ⁴ , but the hydrogen atom of the radical OH or one or both hydrogen atoms of the radical NH _{2 can be} replaced by a trimethylsilyl radical,
breaks off and if necessary
3.1.) The trimethylsilyl group (s) is split off by alcoholysis or hydrolysis. 3. Use of the compounds of claim 1 as a compatibilizer for polymers which are immiscible or only miscible with one another. 4. Use of the compounds of claim 1 as a modification agent for pigments and fillers to improve their ver inertness with organic binders and Paints.