DE2008426A1 - - Google Patents

Description

Applicant? Ceskoslovenskö Academy ved _{# /} Praha 1

¹¹ Process for the preparation of spatially crosslinked silicone polymers "

The invention relates to a new method for the preparation of crosslinked Polysiloxanes.

Recently, in the production of spatially crosslinked silicone polymers, the high reactivity of some functional ones has become more and more common Exploited groups through which the side chain of the SiIaxanskelett is substituted. With this goal in mind, silylamines, Sily alcohols, organosilicon epoxy compounds and acids as well as siloxanes with unsaturated groups in the side chain used. These polymers find extensive practical use.

The invention relates to a method for production spatially cross-linked silicone polymer that is based on the addition reaction the SH group of thioalkylsiloxanes with the double bond C = C of alkenylsiloxanes or the NCO group of organic diisocyanates is based. It has been found that the following possibilities can be used to form the aforementioned polymers:

009837/2109

1. Reactions of alkenylsiloxanes of the general formula I with low molecular weight organosilicon dithiols of the general formula II as network-forming components.

Si - * 0 R ¹

R "Si

(CH ₂ )

= CH,

m + n> 30,

n / m = 1/10 to 1/60 χ = 0 to 4,

R, R ¹ , R "are alkyl groups with 1 to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms, aryl groups or siloxy groups in the case of a three-dimensional polymer.

HS (CH ₉ ) -Si - 0 -

S: - 0

R "

Si - (CH ₂ ) _x SH

ρ = 0 to 30, x = 1 to 4,

R, R ¹ , R "are alkyl groups with T to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms or aryl groups.

2. Reactions of alkenylsiloxanes of the general formula I with high molecular weight thioalkylpolysiloxanes of the general formula III.

009837/2109

R 'Si R "

- β

R "

Si - O RSH

III

ρ + q> 30,

σ / ρ = 1/10 to 1/60,

R is an alkenyl group of 1 to 6 carbon atoms, one Cycloalkenyl group having 5 to 8 carbon atoms or one Arylene group, R *, R "_# R ^Mi are alkyl groups with 1 to 6 carbon atoms, Cycloalkyl groups with 5 to 8 carbon atoms or aryl groups.

3. Reactions of polysiloxanes of the general formula III with low molecular weight alkenylsiloxanes of the general formula IV as network-forming components.

CH2 = CH - (CH.) -Si-O-

R ¹ - O R. Si -Si- R " R ¹

= CH ₂ IV

r = 0 to 30, x = 0 to 4,

R, R ', R "are alkyl groups with 1 to 6 carbon atoms, Cycloalkyl groups with 5 to 8 carbon atoms or aryl groups.

4. Reactions of high molecular weight with thioalkyl and alkenyl groups substituted siloxanes of the general formula

R ¹

Si -RSH

I DIl

R ¹

i - C

R ¹¹¹

R ^HI

Si-o RCH = CH,

009837/2109

-A-

whereby

m + η + ρ y 30 and

m / p a is 1 to 1/60, and

R is an alkylene group having 1 to 6 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms or an arylene group and

R ' ₇ R ", R" ¹ denotes alkylene groups with 1 to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms or aryl groups.

5. Reactions of high molecular weight thioalkylpolysiloxanes of the general Formula III or the general formula

HO (RSiO _{1 5) a} (R ^f R "SiO) _b / R ^{L (I} (RSH) Si / _c OH

whereby

a + b + c y 5 and

c / a + b = 1/5 to 1/60, and

R, R ¹ , R ", R ¹ " denotes alkyl groups with 1 to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms or aryl groups, with organic diisocyanates, such as with hexamethylene diisocyanate, toluene-2,4-diisocyanate, benzene - !, 4 -diisocyanate _{and the like}

It has been found that the reaction of the alkylenesiloxanes with organosilicon thiols proceeds easily at temperatures of 30-110 ° C. in the presence of initiators for radical reactions (such as azobisisobutyronitrile, azomethylvinyldinitrile, etc.) or when initiated by ultraviolet light. The reaction can be carried out without solvent and with an optimal initiator concentration of 0.5-7 wt.% (Based on monomer).

009837/2109

~ ⁵ ~ 2008A26

It was further found that the reaction of the organosilicon thiols with organic diisocyanates in the medium aprotic solvents, or _o can be carried out (preferably between 50 -120 C) without a solvent at moderately elevated temperatures. Further, it was found that an addition of organic substances of a basic nature, such as tertiary amines in the amount of 1.2 to 7 wt.% Of the required (based on the weight of the reaction mixture) in a substantial reduction to form the three-dimensionally networked polymer Time leads.

The process according to the invention for the preparation of spatially crosslinked polymers has one compared to the previously known processes whole series of advantages that consist in that

a) the formation of the cross bridges between the individual polysiloxane chains can be carried out under milder conditions and in much shorter times, and that

b) the resulting polymers are characterized by excellent thermal and chemical resistance and their mechanical Properties can be varied to a large extent by the choice of different mutual proportions of the reactants can.

The subject method can be practically used, for example, for directed crosslinking of linear siloxane elastomers, i.e. H. for their vulcanization at relatively low temperatures, or for the hardening of Silicone varnishes or silicone resins can be used at low temperatures.

009837/2109

The examples given below serve as a detailed description of the process forming the subject of this invention, but without in any way limiting or restricting it want.

example 1

A mixture of 290 g of a linear vinylmethylpolysiloxane of the composition ((CH ₀ = CH) _{,. (CH 0} ), _OR Si0), with the

Z. Ο · οΰ «3 1« VO ι χ

ψ Molecular weight 60,000 from 18 g of the symmetrical bis (thiomethyl) tetramethyldisilixane and from 3 g of azomethylvinyldinitrile (MVN) was heated for half an hour at the temperature of 50 C. During this time, a colorless, highly elastic, spatially networked polyene was created. Heating the polymer prepared in this way in air at 200 ° C. for eight hours did not result in any changes in its mechanical properties.

Example 2

A mixture of 10 g of a high molecular weight linear (thiomethyl) - W -methylpolysiloxane of the composition ((HSCHp) _. (CH-) _ (C ₀ Hc) ₁ flSiO) and 350 g of a linear vinylmethylpolysioxane of the composition ((CH _O = CH ) _ 05 (^^ 0) 1 οκ ^ ίΟ) with degi molecular weight 60,000 was _{heated to the temperature of 90 105 C together with 100 g of a Si0 0} airgel with the addition of 5 g of azobisisobutyronitrile. After 20 minutes
like spatially cross-linked polymer "

Heated to 105 C. After 20 minutes, a colorless, rubber-

009837/2109

Example 3

A mixture of 7 g of a high molecular weight linear (thiopropyl) methylpolysiloxane of the composition ((HSCH-CHLChL) _nn c-

(CH.). 05 ^^) ^urM J ^from 1/2 g of a symmetrical divinyltetramethyldisiloxane was irradiated with UV light for 3 hours. During this time, a transparent, elastic, spatially crosslinked polymer formed.

Example 4

A mixture of oil> 10 g of a high molecular weight linear (thiomethyl) allylmethylpol / siloxane of the composition ((HSCH ₉ ). _M -

(CH ₂ = CHCH ₂ ) ₀ O ₅ (CHg) _{1 94} SiO) _x and 1.5 g of azomethylvinyldinitrile was heated to the temperature of 50 C for half an hour. It a colorless, elastic, spatially cross-linked polymer was created.

Example 5

In a solution of 40 g of a high molecular weight linear vinylmethylpolysiloxane with the composition ((CH ₃ ). Λ (^ ₆ Η _) _ _- (CH „= CH) ₀ (HO) _n «SiO. .) with the molecular weight of 9,800 of 3 g of a thiome

thy! polysiloxane of the composition ((HSCH-J _nn c (CH _Q ). _Of -Si0)

£. U. UO <5 I »" Ο χ

with a molecular weight of 10,000 and 0.6 g of azobisisobutyronitrile transformer plates were immersed in 100 ml of toluene. To Evaporation of the solvent (after 2 hours) became the insulating

The lacquer layer is heated to 100 ° C. for one hour. After this treatment

a non- soluble, non-meltable polymer was created.

- 8 009837/2109 © ^ ^oBl ^ -

Example 6

A mixture of 150 g of a linear thiomethylpolysiloxane of the composition ((HSChL) _n ,. (Ci-L).., SiO) with depi molecular

i. υ «ι v>». y χ

weight of about 30,000 and 15 g of hexamethylene diisocyanate Heated to 80 ° C. for 16 hours under nitrogen. After this time, a colorless, elastic, spatially networked structure formed Polymer.

Example 7

A mixture of 40 g of a linear thiomethylethalpolysiloxane of the composition ((HSCH ₀ ) _n "(C-hL). _Ö Si0) with the molecular

weight of about 60,000, made from 7 g of benzene-1,4-diisocyanate and 1.5 g of pyridine was heated to 70 ° C. for 8 hours under nitrogen warmed up. A colorless, rubber-like, spatially crosslinked polymer was produced. A twelve hour heating of the so prepared Polymer in air at 120 C did not result in any changes in its mechanical properties.

Example 8

In a solution of 60 g of a thiopropylmethylphenylpolysiloxane of the composition (

With a molecular weight of 8.60O ₇ of 3 g of toluene 2 _/ 4-diisocyanate and 1 g of cyclohexyldimethylamine in 100 ml of a mixture of benzene-N, N-dimethylformamide (2: 1), transformer sheets were immersed. After evaporation of the solvent (after 2 hours), the insulating lacquer layer was heated to 120 ° C. for 2 hours. The polymer layer formed was found to be insoluble.

009837/2109 ~ ⁹ ~

Claims (11)

- 9 - "'PATENT CLAIM 1. Process for the preparation of spatially crosslinked silicone polymers ^ characterized in that on by ThioaikyJU group-substituted siloxanes with alkenylsiloxanes or organic diisocyanates is acted upon. 2. The method according to claim 1, characterized in; that also high molecular weight alkenylpolysiloxanes of the general formula R Si-O R ' R "
Si - CH = CH in which m + n> 30, n / m = 1/10 to 1/60, x = 0 to 4 and R, R ¹ , R ^es denotes alkyl groups with 1 to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms, aryl groups or siloxy groups in the case of a three-dimensional polymer with a low molecular weight thioalkylsiloxane of the general formula HS (CH ₉ ) -Si-OR ¹ Si R " Si R ¹ in which P = 0 to 30, ...- ■■ ♦ ■ χ = 1 to 4 and., R, R ¹ , R "alkyl groups with 1 to ό carbon atoms, cycloal 009837/210 9 -K - kyigruppen with 5 to 8 carbon atoms or arvi groups means acting as a network-forming component. 3. The method according to claim 1, gekennr ei honors in that on a high molecular weight AiKenylpoiysiloxar the general formula S; Λ. ^mm R ^T Γ R "
4- Si - 0 I (CH ₀ ) CHCH ₀ in which rr _; -r η> 30, n / m - 1/10 to; / 6C, γ κ O to 4 1 st and R ^ 8% R "alkyl groups with Ί to 6 carbon atoms, Cycloal ~ kyigruppen" with 5 ^{or 8 carbon "stotfatc!} .. ■■: - Ar / l groups or Siioxyqruppen in the case of a three-dimensional C; _: :: c! L .s5 'Polymers means !! ".. ¹ Ii a hoenmclekularer. Thioalkyl pc. ¹ "', oxsr. I ei formula r, Π * L ;, -fq / -10, ■ ϊ / p ^r - "1/10 b: s 1/50 and R is an alkylene group n ^ it 1 'eic 6 Kohl alkyiengrupp" with 5 to 6 KeL -. "- snstof. group and 3n ₇ a cycloeine Arvlen- 009837/2108 R ', R ", R ^MI denotes alkyl groups with 1 to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms or aryl groups, is acted upon« 4. The method according to claim 1, characterized in that that on a high molecular weight thioalkylpolysiloxane of the general formula Si-O RSH which R ¹ q> 30, Si - 0 R " ¹ in P + a / p = 1/10 to 1/60 and R is an alkenyl group having 1 to 6 carbon atoms, a cycloalkenyl group or an arylene group and R *, R ", R ^IM denotes alkyl groups with 1 to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms or aryl groups, with a low molecular weight alkenylsiloxane of the general formula CH - (CH ₂ ) - Si - 0 - - Si - C Si - (CH ₂ ) _x CH = CH ₂ , R ¹ in which r = 0 to 30, xs0 to 4 and R, R ', R "alkyl groups" with 1 to 6 carbon atoms, cycloalkyl denotes groups with 5 to 8 carbon atoms or aryl groups, acts as a network-forming component. 009837/2109 5. The method according to claim 1, characterized in, that the reaction with high molecular weight siloxanes of the general formula R ^{1 Ί}
Si - C
RSH m Τ? "
Si-O
R " ¹ η Si-O- R-CH = CH _n 2 whereby m + η + ρ ^> 30,
m / p = 1 to 1/60 and R is an alkylene group having 1 to 6 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms or an arylene group and R ¹ , R ¹¹ , R " ¹ denotes alkyl groups with 1 to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms or aryl groups substituted with thioalkyl and alkenyl groups, is carried out» 6. The method according to claim 1, characterized in that the high molecular weight thioalkyl-substituted polysiloxanes general formula Si-O Si-O in which a + b ^. 30, but preferably over 100, b / a = 1/10 to 1/60 and R, R ¹ , R ", R" ¹ denotes alkyl groups with 5 to 8 carbon atoms or aryl groups, or the general formula 009837/2109 - 13 - OH (SiO _{1 c} ) (RR ¹¹ SiO), / R " ¹ (RSH) SiO / OH, in which α + b + c> 5, c / α + b = 1/5 to 1/60 and Rj R ¹ , R ", R" ¹ denotes alkyl groups with 1 to 6 carbon atoms, cycloalkyl groups with 5 to 8 carbon atoms or aryl groups, organic diisocyanates are acted upon at temperatures of 30 - 120 C «. 7. The method according to claims 1 to 5, characterized in that the reaction in the presence of an initiator for radical reactions at a concentration of 0.5-7 wt. Based on d
to be led. based on the monomer, and at temperatures of 30 - 110 C through8. Process according to Claims 1 to 5, characterized in that the reaction is carried out at temperatures from 15 to 30 C under irradiation with UV light is carried out. 9. The method according to claims 1 to 6, characterized in that g e k e η η, that the network-forming components toluene-2, 4-diisocyanate, benzene-1,4-diisocyanate or hexamethylene diisocyanate be used. 10. The method according to claims 1, 6 and 9, characterized in that a tertiary amine in amounts of 0.5 to 7 wt. % Based on the weight of the reaction mixture is used as the catalyst. • - 14 009837/2109 11. The method according to claims 1, 6, 9 and 10, characterized in that the reaction is carried out without a solvent or in an aprotic solvent will. 009837/2109