JPS6076536A - Manufacture of alkoxy-terminated polydiorganosiloxane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Presentation of Related Applications This application relates to U.S. Patent Application No. j2θ97y, “Room Temperature Curable Organopolysiloxane Compositions,” filed on the same date as the first application of the present application by the inventors, and White et al. U.S. Patent Application No.,! 77t, 2nd issue (/9 and 2015/2016) ``One package of stable moisture-curable polyalkoxy-terminated organopolysiloxane button fabric and r memo manufacturing method 1. Mistake 1. Both of the above applications are assigned to the applicant.

BACKGROUND OF THE INVENTION Prior to the present invention, Cooper et al.
As shown in No. 2,9θ/, alkoxy-terminated polydiorganosiloxanes were produced by reacting silanol-terminated polydiorganosiloxanes with polyalkoxysilanes in the presence of an amine catalyst.

Another method for preparing alkoxy-terminated polydiorganosiloxanes is shown in U.S. Patent Application Ser. No. 277J, No. 2 to white et al. This method uses an alkoxysilane scavenger together with C
Although the method of Ooper et al. has been found to be effective in forming polyalkoxy-terminated polydiorganosiloxanes useful as base polymers for making room temperature curable compositions, it has been found that the method of Ooper et al. In most cases, high temperatures of 70θ°C or higher are required to obtain
"Also, long reaction times, such as several days or more, are often required. Although good results have been obtained with the above-mentioned U.S. patent application Ser. Dimethoxyenoxysilanes are often expensive to produce and generate undesirable by-products, such as amines.

SUMMARY OF THE INVENTION The present invention provides an alkoxy-terminated polydiorganosiloxane of the following formula: % formula % () (1), a silanol-terminated polydiorganosiloxane of the following formula: % formula % (2) and a silanol-terminated polydiorganosiloxane of the following formula: % formula % (3) of polyalkoxysilane, for example, an effective amount of θ per part by weight of silanol-terminated polydiorganosiloxane/θ
The invention was made based on the discovery that it can be produced in a relatively short time at ambient temperature by using the aluminum complex defined below in an amount of .theta./.about.i0 parts by weight. Here R is C
(1,,,,,3) Hydrocarbon groups, substituted C(+-+s) hydrocarbon groups, and hydrogen groups up to !θmolti and substituted or unsubstituted C(+-+s) hydrocarbon groups as the remaining groups. A monovalent group selected from a mixture of monovalent groups consisting of R+
is selected from monovalent substituted or unsubstituted C(+-+3) hydrocarbon groups, R2 is an alkyl group, an alkyl ether group,
selected from C(+-s) aliphatic organic groups selected from alkyl ester groups, alkyl ketone groups and alkylcyano groups and C(7-+x) aralkyl groups, where a is 0
or an integer equal to /, where n is about θ to about 2!00
is an integer.

The aluminum complex that can be used in carrying out the present invention is represented by the following formula.

(G)mAl (Q), m(4) where G is -OR', -0Si (R')3, -N(R
')2 and -SR' or a divalent group of the following formula: %, where D is 10-1-N- and -S- and mixtures thereof; is a divalent group selected from Z
It'i C(6-,3) 71J-L/'', t
It is a divalent group selected from C(+-8)alkylene, and when D is 10-, 2 can also be 1R1-(SiO)b-Si-R+R1, and b is 0-J -, Q is a monovalent anion selected from C(6J diaromatic hydrocarbon group and substituted C(6-+3) aromatic hydrocarbon group), Q is a monovalent anion selected from is a valent group, R3 and R4 are hydrogen,
R1, -〇R1, O8+ (R'')s, are the same or different monovalent groups selected from acyl and nitrile, R5 is a monovalent group selected from hydrogen, R1 and OR', m is an integer equal to θ-3.

According to the detailed description of the invention, (4) the reaction of 100 parts of the silanol-terminated polydiorganosiloxane of formula (2) with (B) θ/~/θ parts of the polyalkoxysilane of formula (3) is carried out by (Q A process for producing a polyalkoxy-terminated polydiorganosilane of formula +1) is provided, comprising carrying out in the presence of an effective amount of an aluminum complex of formula (4).

Examples of groups included in R and R1 in formula +o, (2) and (3) include hydrogen, aryl groups and halogenated aryl groups, such as phenyl, tolyl, chlorophenyl, naphthyl; alicyclic groups, such as cyclo cyhexyl, j-clobutyl; aliphatic groups such as alkyl and alkenyl groups, in particular methyl, ethyl, propyl, chloropropyl, vinyl, allyl, trifluoropropyl; and cyanoalkyl groups, such as cyanoethyl, cyanopropyl, cyanobutyl There is.

Examples of groups included in R2 include C(+-s) alkyl groups, such as methyl, ethyl, propyl, butyl, and pentyl; C(7-+s) aralkyl groups, such as benzyl; phenethyl; alkyl ether groups; For example -1methoxyethyl; alkyl ester groups, such as 2-acetoxyethyl; alkyl ketone groups, such as /-butane-3-
onyl; an alkylcyano group, such as -monocyanoethyl. In formulas (1) to (4), when R-R5 represents two or more groups, these groups may be the same or different. Groups included in R3, R4 and R5 are, for example, hydrogen, methyl, ethyl, propyl, butyl, trifluoropropyl, allyl, phenyl, chlorophenyl, tolyl, acetoxy, ethoxy, butoxy, trimethylsiloxy, phenoxy, flexoxy.

Specific examples of aluminum complexes included in formula (4) include aluminum di(methoxide) ethyl acetoacetonate, aluminum methoxide di(ethyl acetoacetonate), aluminum di(isopropoxide) acetylacetonate, aluminum di( isopropoxide) ethylacetoacetonate, aluminum isopropoxide di(acetylacetonate), aluminum isopropoxide di(ethylacetoacetonate), aluminum bis(trimethylsiloxide)
Ethylacetoacetonate, aluminum bis(dimethoxymethylsiloxide) ethylacetoacetonate, aluminum bis(dimethoxymethylsiloxide) acetylacetonate, aluminum tri(ethylacetoacetonate), aluminum bis(dimethylamine) ethylacetoacetonate, aluminum /, 3-propane dioxide ethylacetoacetonate, and aluminum di(impropoxide) (methyl salicylate).

A typical method for preparing the aluminum complexes encompassed by formula (4) is to carefully add/~2 equivalents of a chelating ligand, such as acetylacetone or ethylacetoacetone, preferably to a solution of aluminum triisopropoxide. . The sialumium isopropoxide chelate complex can then be obtained by removing volatile products under vacuum.

A similar methoxide complex can be prepared by adding an excess of methanol to an aluminum isopropoxide complex. By quickly removing volatile products, the methoxide group is substituted for the impropoxide group, and the A-aluminum trimethylsiloxide chelate complex replaces the trimethylsilanol with aluminum. It can be similarly produced by adding it to an isopropoxide chelate complex. Aluminum methyl dimethoxysiloxide chelate complexes can be formed by reacting aluminum methoxide chelate complexes with dimethyltetramethoxydisiloxane at elevated temperatures, such as from 6 to 720°C.

All these aluminum complexes are moisture sensitive and
Preferably it is produced under anhydrous conditions, for example in a dry box. An example of producing an aluminum complex is shown below.

To a solution of aluminum di(isopropoxide) ethyl acetoacetonate of /θ02 dissolved in 100 of anhydrous pentane, 2 and 2 of methanol were added dropwise with stirring. The resulting mixture was stirred at υ°C for 7 hours. During this heating period, reaction volatiles, such as pentane and impropatol, were removed by immersion under vacuum. A white crystalline product of and θg was obtained. Based on the manufacturing method and NMR analysis, aluminum cy(methoxide)ethyl acetoacetonate was obtained in varying yields.

Examples of polyalkoxysilanes included in formula (3) include:
Methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, tetraethoxysilane,
Examples include vinyltrimethoxysilane.

The silanol-terminated polydiorganosiloxanes of formula (2) are well known and preferably have viscosities of from about 5 to about 0.000 centipoise, particularly preferably from about 7000 to about 2 J0.000 centipoise, measured at about 23°C. It is in the centipoise range. These silanol-terminated fluids can be made by treating high molecular weight organopolysiloxanes, such as dimethylpolysiloxane, with water in the presence of mineral acids or basic catalysts to adjust the viscosity of the polymer to the desired range. Processes for producing such high molecular weight organopolysiloxanes for use in producing silanol-terminated polydiorganosiloxanes of formula f1) are also well known. Specifically, low molecular weight hydrolysis products can be obtained by hydrolysis of diorganohalosilanes such as dimethyldichlorosilane, diphenyldichlorosilane, methylvinyldichlorosilane or mixtures thereof. Thereafter, an organopolysiloxane with a higher molecular weight can be obtained by equilibration. High molecular weight polymers can also be obtained by equilibration of cyclopolysiloxanes such as octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane or mixtures thereof.
From such polymers, e.g.
Preferably, the equilibrated catalyst is removed before use by standard methods such as those shown in U.S. Pat. No. 37j3θθ2 to Oot.

A silanol-terminated organopolysiloxane having a viscosity as low as /, 2θθ centipoise can be prepared by treating an organopolysiloxane consisting essentially of chemically bonded diorganosiloxy units with pressurized steam. Other methods that can be used to make silanol-terminated polydiorganosiloxanes include Warwick, U.S. Pat.
No. 2107.792 and British Patent No. 3! ;, 790
It is specifically stated in the number.

In the practice of the present invention, the polyalkoxy-terminated polydiorganosiloxane of formula (1) is prepared by reacting the polyalkoxysilane of formula (3) with the silanol-terminated polydiorganosiloxane of formula (2) in an effective amount. It can be produced by carrying out the process in the presence of a complex. The reaction of this silanol-terminated polygeo-JL, ganosiloxane, and polyalkoxysilane can be carried out at a temperature of 20 to 200°C, preferably 2j to 10θ0C.

The end-capping of the silanol-terminated polydiorganosiloxane is carried out by stirring the reaction mixture, etc.
Under ambient conditions approx. This can be achieved in ~72 hours.

The reaction is carried out under moisture-free or substantially anhydrous conditions. This means applying a vacuum to evacuate the air and then mixing in a dry box or closed container purged with dry air, such as nitrogen.

After completion of the endcapping reaction, volatiles can be distilled off from the alkoxy-terminated polydiorganosiloxane, if desired.

To enable those skilled in the art to better practice the invention, the following examples are presented by way of illustration and not by way of limitation.
All parts are parts by weight.

Example / Silanol-terminated polydimethylsiloxane with 22% by weight of hydroxyl groups bonded to silicon, methyltrimethoxysilane ILF and aluminum isopropoxide (
A mixture of ethyl acetoacetonate) θ0232 was mixed in a nitrogen atmosphere under substantially anhydrous conditions. 7 at room temperature
After an hour, a methoxy-terminated polydimethylsiloxane was obtained having about 3 mol-0 methyldimethoxysiloxy units and about 1/7 mol dimethylmethoxysiloxy chain-terminating units based on SiNMR analysis. When this methoxy-terminated polydimethylsiloxane was heated at 7θ°C for 2 hours, SiNMR analysis showed no change in the end-blocking distribution. Next, put the mixture into -n///l mouth L*4 and 1 -JP -R go r flood'lry+ty! '+i
NVIR analysis confirmed that the endcapping distribution of the methoxy-terminated polydimethylsiloxane remained the same.

The mixture of the methoxy-terminated polydimethylsiloxane and aluminum isoproboxoxide (ethyl acetoacetonate) was stirred under substantially anhydrous conditions until a homogeneous mixture was obtained.

Exposure of the resulting mixture to atmospheric moisture for 72θ minutes under ambient conditions yielded a tack-free polydimethylsiloxane.

Example 2 Silanol-terminated polydimethylsiloxane 10θ2 with 909% by weight of chemically bonded hydroxy groups, methyltrimethoxysilane 22 and aluminum methoxydra(ethylacetoacetonate)/! The mixture of the two is mixed under substantially anhydrous conditions.

The 298i N
This was confirmed by MR analysis.

Example 3 Silanol-terminated polydimethylsiloxane with 009% by weight of hydroxyl groups bonded to silicon! A mixture of 02, methyltrimethoxysilane/V and aluminum isopropoxide (ethylacetoacetonate) θθj2 was mixed under substantially anhydrous conditions. Add half of this mixture to 2
Stored at 7°C. After 20 hours, it was confirmed by 29SINMR analysis that a methyldimethoxysiloxy-terminated polydimethylsilicone polymer was obtained. The other half of the mixture was heated to 0°C. After half an hour, it was confirmed by sINMR analysis that this silicone polymer was terminated with methyldimethoxysiloxy groups.

According to the method described in U.S. Patent Application No. 520,929, the methoxy-terminated polydimethylsiloxane and/or!
A mixture of parts of aluminum isopropoxide (ethylacetoacetonate) was stirred under substantially anhydrous conditions until a homogeneous mixture was obtained. Exposure of the resulting mixture to atmospheric moisture for 1 minute under ambient conditions yielded a tack-free polydimethylsiloxane.

EXAMPLE A mixture of the same components as described in Example 3 was prepared, except that the aluminum tri(ethylacetoacetonate) of θθjft was used in place of the aluminum isopropoxide catalyst of Example 3.

The same end-capping rates as described in Example 3 were observed at 2j°C and 0°C.

Example ! Viscosity is 62! Silanol-terminated polydimethylsiloxane which is ℃/ta, θ0θ centipoise! θθ2, methyltrimethoxysilane! A mixture of 2 and aluminum isopropoxide (ethyl acetoacetonate) θ301 was mixed for μ hours under substantially anhydrous conditions. The mixture was heated to 0°C for 7 hours. It was confirmed by Si NMR that a polydimethylsiloxane chain-terminated with methyldimethoxysiloxy groups was obtained.

The above examples illustrate just a few of the numerous variations that can be used in carrying out the method of the invention.
1A-111L 1uaan? ”h-L firefly m1aH
C41r encompasses the use of a very wide variety of silanol-terminated polydimethylsiloxanes, polyalkoxysilanes and aluminum complexes as shown in the description.

Claims (1)

[Claims] / To form a polyalkoxy-terminated polydiorganosiloxane of the following formula: % formula % ( ) ), a silanol-terminated polydiorganosiloxane of (N700 parts of the following formula: % formula %) and (B) 67 A method for producing a polyalkoxy-terminated polydiorganosiloxane, comprising: reacting with ~70 parts of a polyalkoxysilane of the formula: (Q) in the presence of an effective amount of an aluminum complex of the formula: However, R in the formula is a C(+-+s) hydrocarbon group, a substituted C(+
-15>hydrocarbon group, and! A monovalent group selected from a mixture consisting of hydrogen groups up to θ mole and the remainder substituted or unsubstituted C(+-+3) hydrocarbon groups, R1 is a monovalent substituted or unsubstituted C(+-+x) selected from hydrocarbon groups, R2 is a C(+-e) aliphatic organic group selected from alkyl groups, alkyl ether groups, alkyl ester groups, alkyl ketone groups and alkyl cyano groups or C(7-1
3) Aralkyl group, G is 10R', -O8+
A monovalent group selected from the group consisting of (R')s, -N(R1)2 and -8R1 or the following formula: %Formula% (wherein D is 10-, -N- and -S- and a mixture thereof, and 2 is a divalent group selected from C(6 to
, 3) is a divalent group selected from arylene and C(+-a) alkylene, and when D is 10-, Z is a divalent group of (21 in the formula is a divalent group selected from a C(6-+s) aromatic hydrocarbon group and a substituted C(6-+s) aromatic hydrocarbon group, R5 and R4 are hydrogen, R1, -OR'
, O8i(R'), are the same or different monovalent groups selected from acyl and nitrile, R5 is hydrogen,
is a monovalent group selected from R1 and OR'), a is an integer equal to θ or /, n is an integer from about 0 to about 2300, and b is θ m is an integer equal to 0 to 3. The method of claim 1, wherein the silanol-terminated polydiorganosiloxane is a silanol-terminated polydimethylsiloxane. 3. The method according to claim 1, wherein the polyalkoxysilane is methyltrimethoxysilane. (The method according to claim 1, wherein the aluminum complex is aluminum isopropoxide di(ethyl acetoacetonate). ! The method according to claim 1, wherein the aluminum complex is aluminum methoxide ethylacetoacetonate. B. The method according to claim 1, wherein the aluminum complex is aluminum tri(ethyl acetoacetonate). Z. The alkoxy-terminated polydiorganosiloxane reaction product is heated under reduced pressure to remove volatile components. A method according to claim 1, comprising the steps of: