DE2345974C3 - Polysiloxane molding compounds - Google Patents

Description

R'Si (OR ")

_orer or other derate and to the J
ι glass fiber reinforced molded bodies
While meeting with a number of applications to them zugedachtenι purpose, adhere ™ a rh fmhesondere not be on special Tragern in "5 J ^edo J ^ _{ch hands} ^S rs, and their adhesive action

in which R 'is a vinyl or allyl group and IT Yyyy. ^ _{mms at} Closer exposure to elevated a low molecular weight alkyl radical having from 1 ms after _TOTperatur fairly. "_. _e

including 4 carbon atoms means ent- tempe ^ ^^ _{fet therefore} creating a holds, u,. Polysiloxane molding compound, which is made into an elastomer

3 Molding compositions according to claim 2 characterized by 3o JJgJ ^ _{can> the one} , improved adhesion characterizes that the group R 'is a vinyl ^ J? _pre-treated or primed substrates group and the radical R "is a methyl or n ^

sinen ethyl radical means. ^ ₆ polysiloxane formin compositions according to the invention

35 type mentioned at the beginning is now characterized by

"Snet that as component (b) they are about 2 to

Contains 10 parts by weight of diallyl phthalate.

never mixture a) is known per se

The invention relates to polysiloxane _{molding compounds} made from a compound. The usual silicones are on

(.) 100 parts by weight of a mixture of emem g ¹⁰ ^ ₁ oxanes, the methyl, vinyl,

brganopolysiloxane, the repeating one 4 ° W ^ P ^^ ,. g ^^. Trifluoropropyl residues to the

healing general formula silicon atoms of the essentially linear poly-

R ς; π have bound siloxane. Examples for

^{RnSl (} V Se Organopolys! Oxanes are polymers mixed poly-

_Λ .c “L and mixtures of these products, which are classified as

contains, in which R is a methyl, vinyl phenyl ^ or 45 mere oimethylsiloxan-, Phenylmethylsil-

3,3,3-Τπ «ηοφ _Γ ορ _Υ 1 _Γε5 1 and η an average ^ f ^ ₃ . _Trifluor p _r o _P ylmethylsi -, Drphenyllichen value from 1.98 to 2.01 e.nschV ßhch meaning oxane 3.3 £ ^^. _{and P;} vinyisjoxan-

tet, a reinforcing Silic.umdioxid and a süoxan »^ - _Vorzugswe ise at least organoperoxide as a vulcanizing agent and_ (b," _R nne _{meth lreste} p "vinyl

a certain amount of an olefinic "ng" amg so w /. 8th . _{q an amount of up to m 2} , _{/ o> related} compound and possibly customary subgroups ^ ^^ ^ be present while

Sentences. . _{orn d} ^ phenvlreste in an amount of up to 10 · / · the

The adhesion of silicone elastomers to a GRO aie r y ^ _{Q regard Res} te be present Ben variety of substrates such as metals, glass, ASCM ₃ _ _Tri fluorpropylreste up to

Wood, ceramic and plastic matenals is for the 55 ™ 3 _he au / ^U i _Gesamtanzah of the organic radicals ausVerwendung such elastomers of great loading. _Organopo iy _S iloxane are wesentdeutung. In general, it is difficult eme good "fgj ¹¹ ^ _d ie on average from 1.98 to 2.01 of connection between a Süiconelastomeren and Mh ^ to obtain bonded organic radicals per one substrate. Certain Sihcone ver S cuma ο κ ^ _{£ nd u can} bond with a few substrates but require 6o SJaumatome Dimethylvinylsiloxy-, Methyleein pretreatment of the surfaces on the ae «5 T ^ S ^^ eth ^ dipienylsiloxy-, 3,3,3, - Tri to be applied with primers to contain phenyWmyte ^,., ^ ₆ . _In addition, with different substrates an adhesion to ™ ° ^ ° Ρ ^ ™ _en ^y _organ Lchen substituents can! ^^ Ä ^^ iTFSSn ^ SS = _6S d ^ 'dreS.bstituierten ~ "" -

Avoiding priming it is desirable, group of the case.

3 4

The polysiloxane molding compositions according to the invention, the molding composition according to the invention can heat

l can use any of the common reinforcing stabilizers, organic and inorganic fillers

Siliciumoxydiüiistone contain. These fillers are substances, additives to improve the lasting

well known and commercially available from several manufacturers

available. The reinforcing silica fillers 5 improve handling properties, addi-

include fumed silicon dioxide or silicon tive for preventing aging and others

Dioxide aerogels and untreated, treated additives usually found in volcanic heat

or treated in situ. Treated siliconizable polysiloxane compositions are used, ent-

Dioxyde will hold according to known procedures.

produced using organo-ίο the polysiloxane molding compositions according to the invention as the treatment agent

silanes, organopolysiloxanes or silazanes are used. is easily obtained by mixing the ingredients.

The organic compounds used for the molding compounds can be mixed using conventional peroxide vulcanizing agents are known. The procedures can be achieved, e.g. B. Commonly used peroxides include grinding on a rubber mill. The components bis (2,4-dichlorobenzoyl) peroxide, benzoyl peroxide, 15 can be combined in any order. Dicumyl peroxide, p-dichlorobenzoyl peroxide, tert.- An effective process for the production of the invention-butyl perbenzoate, 2,5-bis- (tert-butylperoxy) -2,5-di- according to the invention is to use free-flowing methylhexane or di-tert. -butyl peroxide. Other ingredients, such as diallyl phthalate and / or vinyl peroxide vulcanizing agent, are published in the prepublished trimethoxysilane, to a small amount of the bulk of the literature. _ao substance ii to apply the form of a coating and the

The ratio of the constituents of the molding compositions with a coated filler to that not can vary within a wide range. Vulcanized mass can become clogged,
the amount of reinforcing silica filler composite articles containing a silicone elastomer in amounts in the range of 10 to 200 parts by weight associated with a solid substrate per 100 parts by weight of the organopolysiloxane 25 can be obtained by extending the while the organic Peroxide vulcanized molding compound vulcanized in contact with the nizing agent in amounts of 0.1 to 10 parts by weight of substrate. The vulcanization or the pre-curing per 100 parts by weight of the organopolysiloxane is carried out by heating. The curing temperature can be. The amounts mentioned are the temperature depends on the curing time, the particular one commonly used. A filler content of 30 organopolysiloxane, the type and amount of the 20 to 60 parts per 100 parts of the polysiloxane used is preferred peroxide and the fillers used. away. in general, the curing temperature is

The combination of 100 parts of the above range from 100 to 200 ° C, the Härschritten polysiloxane a) with about 2 to 10 times of a few seconds to several parts by weight of diallyl phthalate leads to a form of 35 hours. The molding compound can be made into a compound which has improved adhesion to any solid substrate, such as metal, for example, handled substrates. Diallyl phthalate steel, aluminum, copper or brass, masonry, can easily be obtained by reacting allyl alcohol with stones, ceramics, glass, wood or polymeric artificial phthalic acid, isophthalic acid or terephthalic acid, substances such as epoxy resins, acrylic resins, nylon or poly- and according to the invention diallyl phthalate 40 ester. Particularly suitable are diallyl isophthalate and diallyl terephthalate, which are linked to nets or fabrics. The unsaturated ester is commercially available. Elastomers include, like hoses or pipes, diallyl phthalate which is not vulcanized, which are used to transport hot liquids. Polysiloxane is relatively compatible, and the following examples are intended to explain the invention that this ester is not
complete compatibility is deposited during vulcanization, resulting in a surface example 1
layer with good adhesion properties.

It was also found that the addition of a mixture of 100 unsaturated silane by grinding the effect of the diallyl phthalate 50 parts by weight of a dimethylvinylsiloxy end groups in terms of improving the adhesion, in particular copolymers, the dimethyl special the retention of the adhesion properties of siloxy and methylvinylsiloxy units and a higher one Temperature and high humidity, vinyl content of about 0.2%, 33 weight improved. Together with the unsaturated ester share a reinforcing Siliciumdioxyds, 5 Gekönnen therefore, unsaturated silanes of the general 55 weight parts of diatomaceous earth and 8.9 parts by weight of the formula of conventional additives to improve the structure and R'Si (OR ") the aging behavior of a mass was produced. ³ During the Grinding was sufficient

in which R 'is a vinyl or allyl group and R "is added dicumyl peroxide to a content of the

a low molecular weight alkyl radical with 1 to 60 vulcanizing agents of 2.5 percent by weight Including 4 carbon atoms means to add up.

are given. Examples of these unsaturated The above composition (100 parts by weight) was with Silanes are Vinyhrimethoxysilan, Allyltriäthoxysilan 4 parts by weight diallyl-o-phthalate mixed up or vinyltriethoxysilane. The silane can result in a smooth mixture in a.

Amount in the range from 0.25 to 2.5 parts by weight 65 The molding composition according to the invention was during per 100 parts by weight of the molding compound a) used for 15 minutes at 150 ° C using different

will. those not pretreated and not primed

In addition to the ingredients listed above, substrates are molded. The adhesion of the vulcanized

Rubber was rated using the following scale:

0 - no initial tack;

1 - good initial adhesion, poor adhesion after

4 hours in water at room temperature;

2 - good initial adhesion, poor adhesion after

24 hours in water at room temperature;

3 - good adhesion after 24 hours in water

Room temperature, poor adhesion after 1 hour in boiling water;

4 - good adhesion after 1 hour in boiling

Water, poor adhesion after 4 hours in boiling water;

5 - good adhesion after 4 hours in boiling

Water.

A rating labeled “good” indicates a cohesive failure of the rubber. For comparison purposes samples of the unmodified rubber were also bonded to substrates and vulcanized onto it, whereupon the adhesion was determined. The results obtained are in summarized in the following table:

Substrate

Adhesion rating of the silicone rubber, the 4 parts by weight

Diallyl

o-phthalate

contains

Not modified

Silicone rubber

Glass

aluminum

steel

Stainless steel

tin

Brass

Polyimide film

Folycarbonate film

Polyester film

Polyamide film

Polyester fabric

2 4 3 4 4 3 5 5 5 5 4

0 0 0 0 0 0 0 0 0 0 0

It can be seen that the addition of diallylphthalate gives good adhesion to glass, good adhesion Dry and wet adhesion to various metals and good adhesion in difficult conditions (boiling water) on a wide variety of synthetic plastics, while not modified rubber itself is insufficient in terms of initial adhesion to the substrates Results.

Example 2

A mixture of 1 part by weight of vinyltrimethoxysilane and 4 parts by weight of diallyl o-phthalate mixed and based on 5 parts by weight of a precipitated silica with a high specific surface area applied. The treated silica was then added with 100 parts by weight of that described in Example 1 Grind the mass.

The molding composition according to the invention was applied to glass and aluminum plates and heated vulcanized for 15 minutes at 150 ° C. The adhesion of the vulcanized rubber to them Substrate was good even after being immersed in boiling water for 4 hours.

Example 3

By grinding 100 parts by weight of one MiEChs containing dimethylvinylsiloxy end groups Svmerisate from about 92.3 · /. Dimetnylsüoxyemheitpn about 75% phenylmethylsiloxy units and about 0 2 · /. Methylvinylsiloxy units, 42 parts by weight of a reinforcing silica filler, 1i 0 parts by weight of a hydroxyl end group Polvdimethylsiloxanöls and 10 parts by weight of e ^ i 3 reinforcing filler and one Piments was then made into a mass a mixture of 4 parts by weight of diallyl phthalate, iGeStel Vmyltriethoxysilan 3 parts by weight "Diltome earth as a filler and 1 part by weight Benzoyl peroxide with 100 denier by weight Grind the mass.

The molding composition according to the invention was vulcanized onto various substrates at 127 ° C. for 5 minutes. The adhesion to aluminum! Brass, copper, stainless steel, cold rolled steel, and polyester cloth were excellent, with any substrate failing to cohesive. Similar results are obtained if the _{copolymer containing phenyl groups used in a5 of} the molding composition described is replaced by a polydimethylsiloxane containing hydroxyl end groups.

Example 4

By grinding 100 parts by weight of a copolymer with hydroxyl end groups, which has about 99.6 "/ o 3,3,3-fluoropropylmethylsioxy units and about 0.4 /. Methyl-methylsiloxy- ₃ , units, 0.6 parts by weight 2,3-dichlorobenzoyl peroxide, 42 Weight of the reinforcing sumdioxide filler, 25 weight of a 3,3,3-fluoroscale polysiloxane oil containing hydroxyl end groups and 2.1 weight of a stability-promoting additive, a mass was then prepared The molding composition according to the invention was molded onto an unprimed aluminum plate and vulcanized for 50 minutes at 150 ° C. and then post-cured for 8 hours at 200 ° C. For comparison purposes, part of the unmodified composition was subjected to the same conditions connected to an aluminum plate who had been coated with a gnin fee obtained in the trade. The molding compound according to the invention showed a cohesive failure «of 1,85 kg / cm width when it was peeled off at an angle of 180 ° on an examination device, while the unmodified compound, which was vulcanized together with the primed substrate, showed an adhesion failure of the connection at 1 , 04 kg / cm

⁶⁰ ^ It can be seen that Polysiloxanformmassen the invention show improved adhesion to unprimed substrates.

Comparative experiment

To demonstrate the unexpected technical progress of the polysiloxane form according to the invention

mass is a comparison with the from the DT-AS 17 19 316, Table II, emerging trialiyl cyanurate accomplished.

To produce a base mixture, 100 parts of a dimethylvinylsiloxane-terminated copolymer of 88 ⁰ Zo dimethylsiloxy units and

12% methylvinylsiloxy units and 42 parts Fumed silica, which you previously used to reduce the existing siloxy groups with trimethylsiloxy groups treated, mixed together. The material thus obtained is divided into two equal parts and processed as follows:

materials part One Part II Basic mix ...
Diallyl phthalate
ViSi (OAe),
Triallyl cyanurate ...
Diatomaceous earth ....
peroxide
liability 100
4th
1
5
1.5
kg / cm 100
1
4th
5
1.5
kg / cm

liability part One
(kg / cm) Part II
(kg / cm) after 2 hours
Hardening at 150 ^° C
after 2 hours
Hardening at 150 ^° C
and 24hours
Aging at 200 ° C 2.95 (more cohesive
Fracture)
2.32 (more cohesive
Fracture) l, 26 (more adhesive
Fracture)
l, 17 (more adhesive
Fracture)

The above values clearly show that the diallyl- »ο remains even after 24 hours of a phthalate a stronger adhesion on cold-rolled material at 200 ° C the adhesion to about 80% Steel gives as triallyl cyanurate. Obtained from diallyl phthalate.

Claims (1)

To develop one _"w ith 7usätzen to the ge Masses with ^additional ^ ⁿ _erzie i _s. The _addition of the h »e ^ afTungl m achieve. The addition of the 2 ^ 7 _verb essemden ingredients to Silicon: claims! Ξ ^ problematic because certain components of the SSS ™ S "ÄAdende units ur ™ ^^" _dg , _s F ¹¹¹ J " ¹ '_, ^lul , j-jT AC1719 316 WCIUCU uuuu woiiu- of the general formula ^^ Gteß or impregnating resins based on R _n SiCVn 5o? Orgiopolysiloxanes with an average of min- ^{2 10} ^ t I Ql SiC-bonded olefinically unsaturated