RU2685545C1 - Oligosiloxanes with hydrophilic and hydrophobic branches as a modifier for siloxane rubber and a method for production thereof - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to synthesis of organosilicon compounds in which silicon is bonded to oxygen-containing groups. Disclosed are oligosiloxanes with hydrophilic and hydrophobic branches of general formula (I), where n equals 9, m equals 500–540, as a modifier for siloxane rubber. Method for production thereof is also disclosed.(I).EFFECT: disclosed oligosiloxanes significantly improve physical and mechanical properties of sealants based on siloxane-modified rubber 60 modified with disclosed oligosiloxanes, and disclosed method of producing simplifies the process of producing modified siloxane rubber.2 cl, 2 dwg, 4 ex

Description

The invention relates to the field of synthesis of organosilicon compounds, where silicon is associated with oxygen-containing groups. New compounds oligosiloxanes with hydrophilic and hydrophobic branches of the general formula I are proposed.

where n is equal to 9, m is equal to 500-540, as a modifier for siloxane rubbers and a method for their preparation.

Known comb-shaped polymethylsiloxanes of the formula

where X is the same radical selected from the series: -Si (CH ₃ ) ₂ CH = CH ₂ , -Si (CH ₃ ) ₃ , -Si (CH ₃ ) ₂ H;

Y is the same radical from the series: -CH ₃ , -CH = CH ₂ ;

n is an integer from the range of numbers from 12 to 600;

m - 0 or an integer from the range from 1 to 11;

These polymethylsiloxanes are obtained by reacting a poly (sodium oxy) methylsiloxane and a siloxane oligomer selected from a range of oligomers of the general formula

where X is a radical selected from the series: -Si (CH ₃ ) ₂ CH = CH ₂ , -Si (CH ₃ ) ₃ , -Si (CH ₃ ) ₂ H;

m is 0 or an integer from the range from 1 to 11;

Z is —Cl or —OC (O) CH ₃ ; in the medium of an organic solvent of toluene or dimethyl sulfoxide, or hexane at a temperature of from 0 ° C to 25 ° C. The precipitate is filtered off. The solvent is removed in vacuo.

Known comb-shaped polymethylsiloxanes were not used as a modifier for siloxane rubbers, see RU Patent No. 2440382, IPC C08G 77/04 (2006.01), C08G 77/20 (2006.01), C08G 77/382 (2006.01), 2012.

Known polyorganosiloxanes with hydrophilic simple polyester branches of the general formula:

where R is selected from the series: hydrogen, phenyl, ethyl or methyl fragment;

n is 1 to 1000, m is 1 to 1000, f is an O atom;

x - yO- (CH ₂ CHR ₁ 0) _v (CH ₂ CHR ₂ O) _z (CH ₂ ) _w - or y- (CH ₂ ) _w -;

y is an aliphatic hydrocarbon fragment in which the number of carbon atoms is 1-18;

v - 1 to 1000, z - 0 to 1000, w - 1 to 18;

R ₁ is selected from the range: methyl, ethyl or propyl;

R ₂ is selected from the range: hydrogen, methyl, ethyl or propyl;

R ₃ is a hydrocarbon moiety selected from the series: hydrogen, methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, alkyl radical containing 5-18 carbon atoms, substituted and unsubstituted aromatic hydrocarbon, fluorine-substituted, halogen-substituted and cyclic hydrocarbons.

Preferably for polyorganosiloxanes, including side polyether fragments, ethers of the general formula are used:

where p is the mass content in percent of hydroxypropylene units (45-60%);

q - mass content in percent of oxyethylene units (40-55%);

y is an aliphatic hydrocarbon fragment in which the number of carbon atoms is 1-18;

as silicones use compounds of the general formula:

where n is 1 to 1000;

R is an alkyl radical selected from the series: methyl, ethyl, n-propyl, isopropyl.

These polyorganosiloxanes are obtained by reacting the organosiloxane polymer with a polyether in the presence of a zinc (II) acetylacetonate catalyst at a temperature of 90-160 ° C for 3-5 hours, and then cooling the reaction medium to ambient temperature to complete the reaction.

No known polyorganosiloxanes were previously used as a modifier for siloxane rubbers,

see RU Patent No. 2609260, IPC C08G 77/38 (2006.01), C08G 77/46 (2006.01), C08L 83/12 (2006.01), D21H 17/59 (2006.01) D21H 17/53 (2006.01), 2017.

Known linear organopolysiloxanes with different functional groups at the ends of the chain of the general formula:

where R ¹ is a hydrocarbon fragment containing from 1 to 20 carbon atoms selected from the series: methyl, ethyl, propyl, cycloalkyl groups, amino, alkoxy groups;

m - 1 to 300;

Q ¹ and Q ² - hydrocarbon fragments containing from 1 to 20 carbon atoms (amide or ether, or urethane groups); as Q ¹ and Q ² hydrophilic fragments of the formula:

where k is from 0 to 6;

g is from 1 to 4;

* - Si fragment of formula (I);

** - A or B;

A is a functional group bound to an organometallic moiety (an alkoxy group or an amino group, or a halogen atom);

B is hydrogen or compounds A;

b is 0 or 1.

Linear organopolysiloxanes are obtained at a synthesis temperature of 80-90 ° C for 3-4 hours by reacting a cyclic siloxane or disiloxane, each of which has one functional group with an organometallic compound, and then reacting the resulting compound with a metal silicate to form a siloxane compound, which has 2 functional groups.

Known linear organopolysiloxanes with different functional groups at the ends of the chain were not previously used as a modifier for siloxane rubbers,

see EP Patent No. 3385268 A1, IntCl C07F 7/10 (2006.01), C08F 30/08 (2006.01), C08B 61/00 (2006.01), C07F 7/08 (2006.01) C08G 77/04 (2006.01), 2018.

Known hydrophilic / lipophilic modified gross polysiloxanes of the formula:

[M _a D _b T _c Q _d ] _e

where M is equal to R ₃ SiO _1/2 ;

D is equal to R ₂ SiO _2/2 ;

T is equal to R ₃ SiO _3/2 ;

Q is SiO _4/2 ;

a is 1-10; b is 0-1000; c is 0-1; d is 0-1; e is 1-10. Modified polysiloxanes contain a structural element of the formula:

where the structural element contains at least one R ⁹² - lipophilic and R ⁹¹ - hydrophilic groups, f - 1-600, in which R ^{91 is} selected from the group consisting of R ¹¹ or R ⁶ or R ⁷ ;

where R ¹¹ contains a fragment of Z- (AE) _y ;

where Z is a hydrocarbon residue With ₂ -C ₂₀ that may contain one or more groups selected from -O-, -NH-, -N- and may be substituted by one or more OH groups;

Preferably Z is selected from the range:

where z is from 1 to 4, x-1

where the * in each case denotes the groups selected from the series:

in which Si takes place in position 2.

Where A is a bivalent residue

y is 1 or 2.

Where E is selected from the group that contains E ² or E ³ , or E ⁵ :

where E ² equals -OC (O) -R ²² , in which:

R ²² is an unsaturated hydrocarbon residue containing up to 9 carbon atoms and which may contain one or more groups selected from the range: -O-, -NH-, -NR ³ - (R ^{3 is a} hydrocarbon residue containing up to 6 carbon atoms) , —C (O) -, and R ²² may be substituted with one or more OH groups.

Where E ³ contains a fragment

in which E ² is described above, and x is 1-4.

Where E ⁵ contains a fragment -NR ⁴¹ R ⁵¹ , in which R ⁴¹ and R ⁵¹ is a hydrocarbon residue containing up to 9 carbon atoms and which may contain one or more groups selected from -O-, -NH-, -NR ^3- (R ^{3 is a} hydrocarbon residue containing up to 6 carbon atoms), and may be replaced by one or more —OH and / or N ₂ N.

Where R ⁶ (see II) contains a fragment -ZE ² ,

in which Z and E ² are as described above.

Where R ⁷ (see III) contains a fragment of -ZE ⁶ ,

in which E ⁶ is -NH-C (O) -R ⁴¹ , and R ⁴¹ is as previously described. The lipophilic group R ^{92 is} selected from the group consisting of R ¹ or R ⁶ or R ⁷ ;

where R ¹ is -Z- (AE) _y , f is 1-300, y is 1 or 2.

Where Z and A is as described above for R ⁹¹ ;

where E is selected from the group that contains E ² or E ³ or E ⁵ ,

where E ² is -OC (O) -R ²³ , in which R ²³ is an unsaturated hydrocarbon residue containing from 10 to 50 carbon atoms and which may contain one or more groups selected from -O-, -NH-, -NR ³ (R ^{3 is a} hydrocarbon residue containing up to 6 carbon atoms), -C (O);

E ³ contains a fragment

E ² is as described above for R ⁹² , and x is 1-4.

Where E ⁵ contains a fragment of —NR ⁴² R ⁵² , in which R ⁴² and R ^{52 is a} hydrocarbon residue containing from 10 to 30 carbon atoms and which may contain one or more groups selected from —O—, —NH, —NR ³ - (R ^{3 is a} hydrocarbon residue containing up to 6 carbon atoms), C (O), R ⁴² and R ⁵² can be substituted by one or more OH and / or H ₂ N groups.

Where R ⁶ (see IIa.) Equal to - Z ² -E, where E ² is as described above for R ^92; R ⁷ (see IIIa) is -Z-E ⁶ , where E ⁶ is -NH-C (O) -R ⁴² , where R ⁴² is as described above;

Hydrophilic / lipophilic modified polysiloxanes are prepared in several ways:

Polysiloxane containing a hydrophobic fragment of an epoxy group is reacted with compounds containing hydrophilic groups: carboxylic acids and amines, or amines and carboxylic acids, and carboxylic anhydrides (they can be esterified by adding monohydric or polyhydric alcohols); either the polysiloxane with functional hydrophobic SiH groups is reacted with monofunctional olefinic or acetylenic unsaturated glycerol esters, which contain hydrophilic and hydrophobic fragments; either polysiloxane with functional hydrophilic amino groups is reacted with carboxylic acids or with compounds containing hydrophobic epoxy functional groups. The interaction process is carried out at a temperature of 80-120 ° C for 6-12 hours, followed by a two-hour evacuation of volatile components at 70 ° C and a pressure of 20 mbar, see. Article Hydrophilic / lipophilic modified polysiloxanes as emsulsifiers / Nov 24, 2010 - Momentive Performance Materials GmbH / https: //patents.justia.com/patent/9340650.

These hydrophilic / lipophilic modified polysiloxanes were not previously used as a modifier for siloxane rubbers,

see EP 2504381 B1, Int C1 C08G 77/14 (2006.01), C08G 77/388 (2006.01), C08G 77/46 (2006.01) C08L 83/08 (2006.01), C08L 83/12 (2006.01), A61K 8 / 892 (2006.01), C08J 3/03 (2006.01), 2018.

Known oligo (alkylene) alkoxysiloxanes containing functional groups of the general formula

where R is CH ₃ , C ₂ H ₅ , C ₃ H ₅ , C ₄ H ₉ , x is 0 or 1, m is 5 to 15; These oligo (alkylene) alkoxysiloxanes are obtained by the hydrolytic condensation of an alkylene trialkoxysilane with water in a liquid alcohol-aqueous medium by boiling for 5 hours. Methanol or ethanol, or propanol, or butanol is used as the alcohol. A disadvantage of the known oligo (alkylene) alkoxysiloxanes is that the functional group containing double bonds does not allow obtaining relatively stable oligosiloxanes due to the susceptibility of the double bond to the addition reactions.

Compounds of oligo (alkylene) alkoxysiloxanes containing the indicated functional groups were not used as a modifier of siloxane rubbers,

see RU Patent No. 2387677, IPC C08G 77/20 (2006.01), C08G 77/06 (2006.01), C08G 77/14 (2006.01), 2010.

Copolymers of polysiloxane with hydrophilic polymer end chains of the general formula are known.

where r is 0 or 1;

A ₁ and A ₂ are a linear or branched C ₁ -C ₂ alkylene bivalent radical;

X ₁ , X ₂ , X ₃ - linking group, including the direct bond -O-, -N-;

или

L ₁ , L ₂ - groups selected from the row:

or

PDMS is a divalent polysiloxane radical corresponding to the formula

where v is 0 or 1, w is from 0 to 5;

U ₁ , U ₂ is a divalent radical corresponding to the formula —R ₁ -X ₄ -EX ₅ -R ₂ , in which R ₁ and R _{2 are} linear or branched C ₁ -C ₁₀ alkylene divalent radical;

X ₄ , X ₅ - a linking group comprising a bond -O- or -N-;

E is an alkyl diradical containing from 1 to 40 carbon atoms, which can be linked to the main chain via an ether bond;

D ₁ D ₂ and D ₃ is a divalent group corresponding to the formula

where m and p are from 2 to 698;

R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ - C ₁ -C ₈ alkyl;

Y ₁ , Y ₂ - a bivalent radical selected from the series:

in which R ₁₂ and R ₁₃ are hydrogen or C ₁ -C ₈ alkyl;

alk 'is a linear or branched C ₁ -C ₁₀ alkylene bivalent radical;

A and A ₄ are groups selected from the series: -O- or -S-;

A ₃ is a linking group comprising a bond -O- or -N-.

Where T is a hydrophilic polymer chain consisting of monomeric units from one or more hydrophilic vinyl monomers selected from the range: M-vinyl-2-pyrrolidone (NBP), N, N-dimethylacrylamide (DMA), dimethylaminoethyl methacrylate, N-vinyl-N -methyl isopropylamide, N-vinyl-N-methylacetamide and vinyl alcohol.

These copolymers of polysiloxane with hydrophilic polymer end chains are prepared by mixing at least one hydrophilic vinyl monomer with polysiloxane having at least one functional group capable of polymerizing the composition.

Polysiloxane copolymers with hydrophilic polymer end chains have not been previously used as a modifier for siloxane rubbers, see RU Patent No. 2524946, IPC C08G 77/442 (2006.01), C08F 283/12 (2006.01), G02C 7/04 (2006.01), 2014.

The closest to the technical essence are silicon compounds obtained by hydrolysis and condensation of alkoxysilane containing epoxy functional groups of the general formula:

and silane with organic functional groups of the general formula

Where

R, R 'is an H atom or an alkyl group with the number of carbon atoms from 1 to 6 (preferably selected from the series: H, -CH ₃ , -C ₂ H ₅ , -C ₃ H ₇ , -C ₄ H ₉ );

A and A 'is a bivalent alkyl group with the number of carbon atoms from 1 to 10, (preferably chosen from the series: - (CH ₂ ) -, - (CH ₂ ) ₂ -, - (CH ₂ ) ₃ -, -CH ₂ - CH (CH ₃ ) -CH ₂ - for A 'and the group - (CH ₂ ) - for A);

R ² is an alkyl group with the number of carbon atoms from 1 to 20, the substituents may be groups bearing the atoms N, O, S, halogen, such as fluoroalkyl, aminoalkyl, mercaptoalkyl, methacryloxyalkyl, methoxy groups or ethoxy groups;

x - 1 to 50;

y - 0 to 50, with x together with y greater than or equal to 2;

n is 0 or 1;

Known silicon compounds are obtained in the presence of water and a catalyst with stirring by reacting an alkoxysilane containing epoxy functional groups with an alkoxysilane containing organic functional groups, with one mol of the alkoxy group taking from 0.001 to 5 moles of water, boron acid is used as a catalyst, the process is carried out at a temperature of from 50 to 70 ° C, a pressure of 500 to 100 mbar for 6-12 hours.

These silicon compounds were not previously used as a modifier for siloxane rubbers.

see RU Patent No. 2495059, IPC C08G 77/08 (2006.01), C08G 77/14 (2006.01), 2013.

A technical problem is the development of oligosiloxanes with hydrophilic and hydrophobic branches, used as a modifier for siloxane rubbers.

The technical problem is solved by a new structure of oligosiloxanes with hydrophilic and hydrophobic branches of the general formula

where n is 9, m is 500-540, as a modifier for siloxane rubbers.

These compounds oligosiloxanes with hydrophilic and hydrophobic branches are obtained with stirring by reacting tetraethoxysilane with polyoxyethylene glycol in the presence of from 0.04 to 0.09% water taken from the mass of tetraethoxysilane and polyoxyethylene glycol, and potassium diethylene glycol catalyst at a temperature of 95 ° C to obtain a homogeneous reaction mixture , with its subsequent interaction with siloxane rubber, with a mass ratio of tetraethoxysilane: polyoxyethylene glycol: siloxane rubber 2: 2: 1, respectively And evacuation at the pressure of 20 mm Hg until complete removal of boiling components.

The obtained oligosiloxanes with hydrophilic and hydrophobic branches allow to reduce the time of obtaining modified siloxane rubbers by 4-5 times in comparison with the industrial method of obtaining siloxane rubber, improve 1.5-2 times the physical and mechanical properties of sealants based on them, simplify the process of obtaining modified siloxane rubbers.

To obtain the claimed oligosiloxanes with hydrophilic and hydrophobic branches use:

Tetraethoxysilane (C ₂ H ₅ O) ₄ Si is a liquid with a characteristic odor, the molecular weight is 208.34, the melting point (T _PL ) is minus 82.5 ° C, the boiling point (T _kip ) is 169 ° C, the flash point ( T _g ) is equal to 48 ° C, the relative density of ρ at 20 ° C is 0.9676 g / cm ³ , see “Chemist's Handbook. The basic properties of inorganic and organic substances "T. 2, L.-M .: Chemistry, 1964 p. 948-949.

Polyoxyethylene glycol-9 HO - [- CH ₂ -CH ₂ -O-] ₉ -H is a light or yellow liquid with a faint characteristic odor, the molecular weight is 400, the hydroxyl number KOH mg / 1 g is 260-290, the mass fraction of water is not more than 0.7%, see. TU 6-14-714-79.

Siloxane low molecular weight rubber, grade "A" (SKTN-A) of the formula [-OSi (CH ₃ ) ₂ ] _n ,

where n is 500-540 siloxane units, a viscous colorless liquid without mechanical impurities, the molecular weight is 37-40 thousand, the conventional viscosity is 90-150 seconds, see GOST 13835-73.

Potassium diethylene glycolate (DEG-K)

BUT - С ₂ Н ₄ -О-С ₂ Н ₄ -ОК,

Synthesized in laboratory conditions, in which the content of potassium-alcoholate groups of the total number of hydroxyl groups is 10%, the molecular weight is 144, the melting point ( _Tm ) is from minus 35 to 30 ° C, the boiling point (T _kip ) is 264 ° WITH.

Octamethylcyclotetrasiloxane ((CH ₃ ) ₂ SiO) ₄ is a clear, colorless liquid without mechanical impurities, the molecular weight is 296, the melting point ( _Tm ) is 17.4 ° C, the boiling point (T _kip ) is 175.8 ° C, relative ρ density at 20 ° С is 0.9558 g / cm ³ , see TU 6-02-1-027-90.

The structure of the obtained oligosiloxanes with hydrophilic and hydrophobic branches is confirmed by infrared spectroscopy (IR spectroscopy), where the wavenumbers measured in cm ^{-1 are} plotted on the abscissa axis, the log transformation Lg (1 / R), where R is the reflection coefficient , and the method of dynamic light scattering, where the particle size measured in nm is plotted along the abscissa, the fraction of particles,%, is plotted along the ordinate.

The structure of oligosiloxanes with hydrophilic and hydrophobic branches is in good agreement with the presence of absorption bands in the IR spectrum, see FIG. 1, line 3 in the region of 1010 cm ¹ and 1080 cm ¹ , characteristic of stretching vibrations of Si-O-Si bonds. These analytical absorption bands are also present on the IR spectrum of siloxane rubber, see

FIG. 1, line 1, while the intensity of these bands significantly exceeds the intensity of the analytical absorption bands of 1010 cm ¹ and 1080 cm ¹ for oligosiloxanes with hydrophilic and hydrophobic branches, the absorption band of 1090 cm ¹ with a shoulder at 1070 cm ^-1 indicates a change in bonds in the compound, leading to the formation of the claimed oligosiloxanes with hydrophilic and hydrophobic branches. The presence of a broad band in the region of 1100 cm ^-1 , see FIG. 1, line 2 characterizes the C – O – C bond in polyoxyethylene glycol — 9, which is completely overlapped by the spectrum of oligosiloxanes with hydrophilic and hydrophobic branches. This indicates that the absorption band of 1090 cm ^-1 with a shoulder at 1070 cm ^-1 characterizes the Si-OC bonds, see FIG. 1 line 3 and identifies oligosiloxanes with hydrophilic and hydrophobic branches. The expansion and shift to the high-frequency region of the absorption band of 1085 cm ^-1 and the appearance of a shoulder at 1135 cm ^-1 is due to the formation of branched siloxane structural elements, see FIG. 1, line 3. The presence of absorption bands at 850 cm ^-1 and 890 cm ^-1 on the IR spectrum is due to the stretching vibrations of the Si-O bond in the composition of the Si-OH siloxane rubber, see Figure 1, line 1. Analytical bands at 870 cm- ¹ and 890 cm ^-1 , characteristic for the terminal silanol groups of siloxane rubber, are absent due to their involvement in the transesterification reaction with polyoxyethylene glycol, see FIG. 1, line 3.

The size distribution of oligosiloxane particles with hydrophilic and hydrophobic branches in a toluene solution is determined by dynamic light scattering, see FIG. 2

The average particle size of oligosiloxanes with hydrophilic and hydrophobic branches is in the range of 60–700 nm with a maximum at 100 nm, and an increase in the proportion of particles with a size distribution in the range of 10–30 nm occurs, see FIG. 2

The invention is illustrated by the following examples of specific performance.

Example 1. Obtaining oligosiloxanes with hydrophilic and hydrophobic side branches is carried out with stirring by reacting tetraethoxysilane 8.54 ml with polyoxyethylene glycol 9.64 ml in the presence of water 20 μl and a catalyst of diethylene glycolate potassium at a temperature of 95 ° C to obtain a homogeneous reaction mass, followed by interaction with siloxane rubber in the amount of 5 ml, with a mass ratio of tetraethoxysilane: polyoxyethylene glycol: siloxane rubber 2: 2: 1, respectively, with further evacuation at ION 20 mmHg until complete removal of boiling components.

Example 2. Siloxane rubber is modified by oligosiloxanes with hydrophilic and hydrophobic branches, obtained in Example 1, by introducing them into octamethylcyclotetrasiloxane in an amount of 0.05% by weight of octamethylcyclotetrasiloxane in the presence of 10 μl of a 50% aqueous solution of KOH at 140 ° C, at This reaction vessel is equipped with a reflux condenser and a glass stirrer. The process is conducted until the termination of the increase in viscosity of the polymer.

Example 3. Getting sealant based on the modified siloxane rubber obtained in Example 2, in accordance with the recipe, in the following ratio, wt. including:

siloxane rubber modified with oligosiloxanes with hydrophilic and hydrophobic branches 100 zinc white ZnO 50 tetraethoxysilane 3

These components are stirred for 3-4 hours at a temperature of 25 ° C.

Example 4. Getting siloxane rubber without the use of the claimed modifier.

Siloxane rubber is obtained by introducing into the octamethylcyclotetrasiloxane 10 μl of a 50% aqueous solution of KOH at a temperature of 140 ° C, while the reaction tank is equipped with a reflux condenser and a glass stirrer. The process is carried out until the termination of the increase in viscosity of the polymer.

The use of oligosiloxanes with hydrophilic and hydrophobic branches as a modifier simplifies the technological process of obtaining anionic polymerization of siloxane rubber. Upon receipt of siloxane rubber without the use of the specified modifier at the final stage of polymerization, it is necessary to neutralize the catalyst, since the absence of the neutralization process in siloxane rubbers reduces its shelf life, which is not more than 7 days, due to the structuring and loss of technological properties of the siloxane rubber.

Upon receipt of siloxane rubber using oligosiloxanes with hydrophilic and hydrophobic branches as a modifier, the need to neutralize the final product is eliminated, which simplifies the process, and the resulting siloxane rubber acquires the ability for long-term storage, which is longer than 5 months.

The time to obtain siloxane rubber without the use of a modifier is 40-60 minutes, and in the presence of a modifier based on oligosiloxanes with hydrophilic and hydrophobic branches in an amount of 0.05 wt. % of siloxane rubber is 7-10 minutes.

Industrial sealant VGO-1 has a Shore hardness value of at least 28 units, a strength of at least 2 MPa, an elongation at break of 250-600%, a pot life of at least 0.17 h. See. TU 38.303-04-04, "Technology of organometallic monomers and polymers" K.A. Andrianov, L.M. Khananashvili. - M .: Chemistry, 1973. - 400 p.

When using oligosiloxanes with hydrophilic and hydrophobic branches in the process of producing siloxane rubber and further in the production of sealant, the sealant hardness according to Shore A is more than 44 units, the tensile strength is from 3.1 MPa, the relative elongation at break is from 360%, viability is from 18 min

Thus, the claimed oligosiloxanes with hydrophilic and hydrophobic branches as a modifier of siloxane rubbers and a method for their preparation simplify the technological process of obtaining modified siloxane rubbers by eliminating the catalyst neutralization stage, increase the shelf life of the siloxane rubber compared to unmodified rubber for more than 5 months, reduce the time of obtaining siloxane rubber from 40 to 7 minutes and get sealants based on modified siloxane Vågå rubber physical and mechanical properties that exceed 1.5-2 times industrial adhesives.

Claims (4)

1. Oligosiloxanes with hydrophilic and hydrophobic branches of the general formula

where n is 9, m is 500-540, as a modifier for siloxane rubbers. 2. A method of producing oligosiloxanes with hydrophilic and hydrophobic branches according to claim 1 in the presence of water and a catalyst with stirring, characterized in that the tetraethoxysilane is reacted with polyoxyethylene glycol in the presence of from 0.04 to 0.09 wt. % of water taken from the mass of tetraethoxysilane and polyoxyethylene glycol, and the catalyst of potassium diethylene glycolate at a temperature of 95 ° C to obtain a homogeneous reaction mass, followed by its interaction with siloxane rubber at a mass ratio of tetraethoxysilane: polyoxyethylene glycol: siloxane rubber 2: with a pressure of 20 mm Hg. until complete removal of boiling components.

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