JP3158987B2 - Method for producing disilanyl organopolysiloxane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a disilenyl organopolysiloxane having excellent heat resistance, and more particularly to a method for producing a disilenyl organopolysiloxane useful as a reinforcing agent for mica products.

[0002]

2. Description of the Related Art
Silane coupling agents, organopolysiloxanes, silicates and the like have been used as surface treatment agents, binders or reinforcing agents for inorganic materials such as mica. Since these substances have a curable functional group, they can be formed into a film by condensation curing at a low temperature.
Cracking due to volume shrinkage is inevitable at about 00 ° C,
Heat resistance was poor.

JP-A-6-263425 and JP-A-6-263
No. 426 describes that a fine, porous silicon-based powder can be obtained by hydrolyzing an alkoxysilane using a fluoride salt compound or a compound having a Si—F bond as a catalyst. There is no suggestion about the application to disilanes having different reactivity, and the shapes are different.

Japanese Patent Application Laid-Open No. Hei 5-295563 discloses an example using a polysilane which does not easily cause cracks, but it is difficult to form a film at a low temperature equivalent to that of a silicone resin. Even at a high temperature of 400 ° C. according to the method described in the above publication, there are some materials such as dimethylpolysilane that cannot be formed into a film. Even the only methylphenylpolysilane that could be formed into a film was inferior in adhesion, chemical resistance, etc., and no satisfactory product was obtained. Therefore, surface treatment agents, binders or reinforcing agents that do not have the above-mentioned disadvantages have been desired.

[0005]

Means for Solving the Problems and Embodiments of the Invention The present inventors have conducted intensive studies in order to meet the above-mentioned demand, and as a result, have found that a disilane containing a hydrolyzable group represented by the following general formula (1) and / or Alternatively, by subjecting the partially hydrolyzed condensate to hydrolysis and condensation using an alkali fluoride or a combined system of a dibasic organic acid and a metal condensation catalyst as a catalyst, the disila represented by the average composition formula (2) is obtained. It has been found that nylorganopolysiloxane can be produced efficiently.

[0006] R¹ _aSi_TwoX_6-a ... (1) (However, R¹ Is a hydrogen atom or a substituted or unsubstituted monovalent
X is a hydrocarbon group, and X is a hydrolyzable group. a is 0,
1, 2, or 3. ) R¹ _cSi_Two(OR^Two)_dO_{(6-cd) / 2} ... (2) (However, R¹ Has the same meaning as above, and R^TwoIs a hydrogen atom
Or a substituted or unsubstituted monovalent hydrocarbon group. c,
d satisfies 0 ≦ c ≦ 3, 0 <d <6, 0 <c + d <6
It is a positive number. )

When this disilane-containing organopolysiloxane is used as a main component of a surface treating agent for inorganic materials, a binder, or a reinforcing agent, it has a curable functional group similarly to a conventional silicone resin, and therefore has a low content. Film formation at temperature is possible, so productivity is improved,
It was also found that the chemical resistance was good.

In addition, since the molecule has a disilane skeleton, at a high temperature, an oxidation reaction of the Si—Si bond to the Si—O—Si bond occurs before or simultaneously with the thermal decomposition of the organic group, and the weight due to the oxidation reaction is increased. It has also been found that by the increase, the volume shrinkage due to the thermal decomposition of the organic group is suppressed, so that the occurrence of cracks can be avoided and the heat resistance becomes good.

Further, disilane as a raw material may be chloro-containing disilane as a distillation residue produced as a by-product during the synthesis of silane, but this disilane is generally discarded as an unsuitable raw material for polysiloxane synthesis, and is therefore disposed of. In many cases, according to the method of the present invention, industrial waste can be effectively used, and it is preferable from the global environment. Therefore, the disilane-containing organopolysiloxane according to the present invention has heat resistance. In addition to imparting performance effects such as adhesion, chemical resistance, and the like, industrial waste can be used as a raw material for its production. This is what led to the invention.

Hereinafter, the present invention will be described in detail.

[0011] The present invention relates to the use of a hydrolyzable group-containing disilane represented by the following general formula (1) and / or a partially hydrolyzed condensate thereof as a catalyst to form an alkali fluoride or a dibasic organic acid with a metal condensation catalyst. Provided is a method for producing a disilanyl organopolysiloxane represented by an average composition formula (2) obtained by hydrolytic condensation using a combination system.

R¹ _aSi_TwoX_6-a ... (1) (However, R¹ Is a hydrogen atom or a substituted or unsubstituted monovalent
X is a hydrocarbon group, and X is a hydrolyzable group. a is 0,
1, 2, or 3. ) R¹ _cSi_Two(OR^Two)_dO_{(6-cd) / 2} ... (2) (However, R¹ Has the same meaning as above, and R^TwoIs a hydrogen atom
Or a substituted or unsubstituted monovalent hydrocarbon group. c,
d satisfies 0 ≦ c ≦ 3, 0 <d <6, 0 <c + d <6
It is a positive number. )

In the equation (1), R¹ Is a hydrogen atom or substitution
Or an unsubstituted monovalent hydrocarbon group having 1 to 1 carbon atoms
0, especially 1-6 are preferred. Specifically, methyl
Group, ethyl group, propyl group, butyl group, pentyl group,
Alkyl groups such as xyl, heptyl and octyl groups;
Cycloalkyl such as clopentyl and cyclohexyl
Group, aryl group such as phenyl group, benzyl group, phenyl
An aralkyl group such as an ethyl group can be exemplified,
In these groups, some or all of the hydrogen atoms are halogenated
And it may be substituted by a substituent atom. Also, as a reactive group
Alkenyl groups such as vinyl group and allyl group,
Aliphatic groups such as cypropyl group and methacryloxypropyl group
Saturated group-containing organic group-substituted alkyl groups can also be exemplified.
You. Particularly preferred among these are methyl groups.

The hydrolyzable group X is a halogen atom,
Examples thereof include an alkoxy group, an acetoxy group, an amino group and an oxime group, and a halogen atom and an alkoxy group are preferred. In this case, the alkoxy group is particularly preferably one having 1 to 4 carbon atoms, and the halogen atom is particularly preferably a chlorine atom.

Here, in the disilane of the formula (2), a
Is 0, 1, 2, or 3 as described above, and a is a> 3
In such a case, the cross-linking rate is reduced, so that the heat resistance is inferior and the adhesion is also lowered, which is not preferable.

The disilane can be obtained as a high-boiling fraction produced as a by-product at the time of synthesis of silane by a conventional metal silicon and alkyl halide reaction. Considering the production cost and the global environment, this disilane can be obtained. It is preferred to use a boiling fraction.

Accordingly, those suitable as the hydrolyzable group X are a chlorine atom obtained as a high-boiling fraction or an alkoxy group which can be derived at low cost by reacting the chlorine atom with an alcohol or the like.

Specific examples of the hydrolyzable group-containing disilane used in the present invention are as follows.

(CH ₃ O) ₃ SiSi (OCH ₃ ) ₃ , (C
H ₃ O) ₂ CH ₃ SiSi (OCH ₃ ) ₃ , (CH ₃ O) ₂ C
H ₃ SiSiCH ₃ (OCH ₃ ) ₂ , (CH ₃ O) ₃ SiSi
(CH ₃ ) ₂ OCH ₃ , (CH ₃ O) ₂ CH ₃ SiSi (CH
₃ ) ₂ OCH ₃ , (CH ₃ O) ₃ SiSi (CH ₃ ) ₃ , Cl ₃
SiSiCl ₃ , Cl ₂ CH ₃ SiSiCl ₃ , Cl ₂ CH ₃
SiSiCH ₃ Cl ₂ , Cl ₃ SiSiCH ₃ , Cl ₂ CH ₃
SiSiCH ₃ Cl

In the equation (2), c and d are 0 ≦ c
≦ 3, 0 <d <6, 0 <c + d <6, more preferably 0
It is a positive number that satisfies <c + d <4. Especially 0 <c + d <4
In this case, the disilane structure has a branched structure, and has excellent heat resistance and mechanical strength.

R ² is a hydrogen atom or a monovalent hydrocarbon group and includes the same groups as R ¹ , such as methyl, ethyl, propyl, butyl, pentyl, hexyl, Examples include an alkyl group such as a heptyl group and an octyl group, a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, an aryl group such as a phenyl group, and an aralkyl group such as a benzyl group and a phenylethyl group. These groups may have some or all of the hydrogen atoms replaced with halogen atoms. Of these, particularly preferred are a hydrogen atom and an alkyl group having 4 or less carbon atoms.

The catalyst used for the hydrolytic condensation is KF, NaF
Or a combination of a dibasic organic acid and a metal condensation catalyst. With a known acidic catalyst such as sulfuric acid or hydrochloric acid or a basic catalyst such as KOH or NaOH as a catalyst for hydrolyzing silane, the heat resistance of the resulting disilanyl organopolysiloxane is insufficient. On the other hand, KF is particularly preferable in a fluoride salt system. Further, the heat resistance is insufficient when the organic acid is used alone, but a disilanyl organopolysiloxane having excellent heat resistance can be obtained by using a metal condensation catalyst in combination.

Here, specific examples of the above-mentioned dibasic organic acids include maleic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, phthalic acid and the like. Preferred is maleic acid.

As the metal condensation catalyst, titanium-based catalysts,
Examples include tin-based, iron-based, and aluminum-based condensation catalysts. Specific examples thereof include tetrabutyl titanate, dibutyltin dioctate, optape iron, and aluminochelate, among which dibutyltin dioctate is particularly preferred.

The above-mentioned hydrolytic condensation can be carried out in the same manner as in known acidic or basic conditions.
It is preferable to carry out the reaction for 3 hours. It is preferable to use an alcohol solvent as the solvent.

The conditions for the combined use of the dibasic organic acid and the metal condensation catalyst may be such that both may be added at the same time. It is preferable to carry out the reaction further using a catalyst. in this case,
When hydrolyzing and condensing with a two-base organic acid, 0 to 100 ° C
Is preferably performed for 0.1 to 5 hours. It is preferable to use an alcohol solvent as a solvent. Next, at the time of condensing with a metal condensation catalyst, the reaction is carried out at 0 to 200 ° C. for 0.1 minute.
It is preferable to carry out the reaction for 5 to 24 hours. At this time, it may be replaced with a solvent having a high boiling point, if necessary.

The disilane-containing organopolysiloxane of the present invention can be used as a main component of a surface treating agent for inorganic materials, a binder or a reinforcing agent. When used in such applications, the disilane-containing organopolysiloxane is sufficiently mixed with an organic solvent such as toluene to form a uniform solution, then uniformly applied to the surface of the inorganic material, sufficiently dried, and adhered. At this time, a known curing catalyst such as an acidic, basic or metal compound may be added as well as a known silicone resin-based surface treatment agent, binder or reinforcing agent. Also,
You may use together with inorganic substance reinforcement materials, such as mica, silica, titanium oxide, and aluminum oxide.

Thereafter, a heat treatment is carried out in the air or under an oxygen atmosphere, and an oxidation reaction is caused if necessary, whereby an inorganic material surface-modified with disilane-containing organopolysiloxane is obtained. In this case, the heat treatment can be performed at 20 to 250 ° C. for 10 minutes to 10 hours.

Specific examples of the inorganic material include iron,
Copper, nickel, aluminum, silicon, stainless steel, brass, glass cloth, brick and the like are not particularly limited. The shape is not particularly limited, and may be a rod, a tube, a bulk, a fiber, a film, or a powder.

Here, the disilane-containing organopolysiloxane obtained by the production method of the present invention can be suitably used when obtaining a silicone mica product such as a mica laminate.

That is, mica is generally used widely because of its excellent electrical properties and heat resistance. However, since its mechanical strength is weak, its mechanical strength is obtained by molding or laminating with a binder. Is used as a mica product. Conventionally, as a binder, a method using a first phosphate-based inorganic polymer or an organic resin is known.However, a binder using an inorganic polymer obtained by condensing a first phosphate metal salt is used as a laminated product. Since a high temperature of 400 ° C. or more is required for forming, special equipment is required, and there is a problem that manufacturing cost is high. In addition, the mica product obtained thereby has excellent heat resistance, but has poor water resistance, and has the disadvantage of impairing mechanical strength and electrical properties in the presence of moisture. On the other hand, when an organic resin such as an alkyd resin, a polyester resin, an epoxy resin, and an acrylic resin is used as a binder, it can be laminated and molded at a relatively low temperature of 100 to 200 ° C., and has excellent mechanical strength. There is a drawback that heat resistance and water resistance are poor. Therefore, in order to solve such a drawback, organopolysiloxanes having better heat resistance and water resistance than organic resins have come to be used as binders. Organopolysiloxanes are
No heat resistance was sufficiently satisfied, such as generation of cracks due to volume shrinkage due to weight reduction accompanying thermal decomposition of organic groups.

However, the present inventors have obtained the catalyst used for the hydrolysis and condensation from a conventional acidic catalyst or basic catalyst by changing to a combined system of an alkali fluoride or a dibasic organic acid and a metal condensation catalyst. A mica laminate was prepared using the disilane-containing organopolysiloxane, and the mechanical strength was measured. Unexpectedly, no decrease in strength was observed even at high temperatures, which was extremely superior to conventional catalyst systems. It has been found that it exhibits characteristics.

When a silicone mica product such as a mica laminate is obtained using such a disilane-containing organopolysiloxane, the disilane-containing organopolysiloxane or a resin composition containing the same as a main component is toluene,
After diluting and mixing with a hydrocarbon solvent such as xylene or petroleum solvent to make a uniform solution, impregnating the peeled mica or aggregated mica, spraying it, applying it by brushing, etc. Evaporate the solvent at low temperatures. At this time, similarly to the silicone resin, a known curing catalyst such as an acidic, basic, or metal compound may be added. Thereafter, the obtained mica pieces containing the disilane-containing organopolysiloxane are superimposed, and if necessary at a temperature of 150 to 250 ° C.
150 kg / cm ² By heating for 15 minutes to 2 hours while applying the pressure described above to cure the disilane-containing organopolysiloxane.

[0034]

According to the present invention, since it has a curable functional group, it can be formed into a film at a low temperature and has a high hardness.
Furthermore, no disilane-containing organopolysiloxane which does not generate cracks due to volume shrinkage at high temperatures and has good heat resistance, and thus can be effectively used as a surface treatment agent, a binder or a reinforcing agent for inorganic materials. It can be obtained efficiently.

[0035]

EXAMPLES The present invention will be described below in detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Example 1 A 1,2-liter separable flask equipped with a cooling tube, a thermometer, and a dropping funnel was placed in a 0.3-liter separable flask.
100 g of a mixture of dimethyl-1,1,2,2-tetramethoxydisilane and 1,1,2-trimethyl-1,2,2-trimethoxydisilane (2: 1 molar ratio), 125 g of methanol and fluorinated 0.03 g of potassium was charged and stirred at room temperature. When 27 g of water was added dropwise over 15 minutes with stirring, the temperature inside the flask was raised to 32 ° C. After further stirring at room temperature for 1 hour, the reaction solution was stripped at a low temperature and methanol was distilled off, and 60 g of toluene was added.
Next, washing with a 20% CaCl ₂ aqueous solution,
After washing with a ₂ SO ₄ aqueous solution, Na ₂ SO _{4 was} dried. After filtration, a toluene solution having a nonvolatile content of 50% was prepared.

The average composition formula of disilanylorganopolysiloxane obtained from ²⁹ Si-NMR, functional group measurement and GPC average molecular weight is [(CH ₃ ) _2.33 Si ₂ (OR) _0.22 O _3.28 ] (OR is OH Group is 40mol%, OCH ₃ group is 60mo
1%).

Example 2 A 1,2-liter separable flask equipped with a cooling tube, a thermometer, and a dropping funnel was placed in a 0.3-liter separable flask.
100 g of a mixture of dimethyl-1,1,2,2-tetramethoxydisilane and 1,1,2-trimethyl-1,2,2-trimethoxydisilane (molar ratio 2: 1), 125 g of methanol and maleic acid 0.6 g was charged and stirred at room temperature. While stirring, 11.3 g of water was added dropwise over 6 minutes, and the temperature inside the flask was raised to 33 ° C. After further stirring at room temperature for 1 hour, 50% of dibutyltin dioctate was added.
0.1 g of a toluene solution was added, and methanol was distilled off from the ester adapter while 100 g of toluene was added dropwise.

After the replacement with toluene, the temperature inside the flask was maintained at 90 ° C., and the mixture was stirred for 1 hour. After cooling, the flask was washed with a 20% aqueous Na ₂ SO ₄ solution. The extract was dried over Na ₂ SO ₄ , filtered, and then adjusted to a toluene solution having a nonvolatile content of 50%.

The average composition formula of disilanylorganopolysiloxane obtained from ²⁹ Si-NMR, functional group measurement, and GPC average molecular weight is [(CH ₃ ) _2.33 Si ₂ (OR) _0.15 O _3.35 ] (OR is OH Group is 40mol%, OCH ₃ group is 60mo
1%).

Comparative Example 1 A 1,2-liter separable flask equipped with a cooling tube, a thermometer, and a dropping funnel was placed in a 0.3-liter separable flask.
100 g of a mixture of dimethyl-1,1,2,2-tetramethoxydisilane and 1,1,2-trimethyl-1,2,2-trimethoxydisilane (molar ratio 2: 1), 104.2 g of toluene and isopropyl 8.9 g of alcohol was charged and stirred at room temperature. After adding 2.0 g of methanesulfonic acid with stirring, 24 g of water was added dropwise over 20 minutes, and the temperature in the flask was raised to 45 ° C. 1 at room temperature
After stirring time, the reaction solution was washed with 20% Na ₂ SO ₄ aqueous solution and Na ₂ SO ₄ dried. Hereinafter, a toluene solution having a nonvolatile content of 50% was obtained in the same procedure as in Example 2.

The average composition formula of disilanylorganopolysiloxane obtained from ²⁹ Si-NMR and functional group measurement is [(CH ₃ ) _2.33 Si ₂ (OR) _0.22 O _3.28 ] (OR is 50 mol% of OH group. , OMe group is 50 mol
%)Met.

Comparative Example 2 A 1,2-liter separable flask equipped with a cooling tube, a thermometer, and a dropping funnel was placed in a 0.3-liter separable flask.
100 g of a mixture of dimethyl-1,1,2,2-tetramethoxydisilane and 1,1,2-trimethyl-1,2,2-trimethoxydisilane (mixing molar ratio 2: 1), 125 g of methanol and 0 g of maleic acid And then stirred at room temperature. Under stirring, 11.3 g of water was added dropwise over 6 minutes, and the temperature inside the flask was raised to 32 ° C. After further stirring at room temperature for 1 hour, the reaction solution was stripped at a low temperature and methanol was distilled off, and 60 g of toluene was added. Next, 2
After washing with 0% Na ₂ SO ₄ aqueous solution and Na ₂ SO ₄ dried. After filtration, a toluene solution having a nonvolatile content of 50% was prepared.

The average composition formula of disilanylorganopolysiloxane obtained from ²⁹ Si-NMR, functional group measurement and GPC average molecular weight is [(CH ₃ ) _2.33 Si ₂ (OR) _0.28 O _3.22 ] (OR is OH Group is 40mol%, OCH ₃ group is 60mo
1%).

Comparative Example 3 100 g (0.74 mol%) of methyltrimethoxysilane, 148 g of methanol and 0.03 g of potassium fluoride were placed in a 0.3-liter separable flask equipped with a cooling tube, a thermometer, and a dropping funnel. Preparation,
Stir at room temperature. When 20 g of water was added dropwise over 15 minutes with stirring, the temperature inside the flask was raised to 35 ° C. After further stirring at room temperature for 1 hour, the reaction solution was stripped at a low temperature, methanol was distilled off, and 40 g of toluene was added. Next, it is washed with a 20% CaCl ₂ aqueous solution, and further washed with 20% Na ₂
After washing with an aqueous solution of SO ₄ , it was dried over Na ₂ SO ₄ . After filtration, a toluene solution having a nonvolatile content of 50% was prepared.

From the results of functional group measurement and GPC average molecular weight,
The average composition formula of the obtained organopolysiloxane is [CH_ThreeSi O_3/2] Met.

Reference Example 1 Examples 1 and 2 and Comparative Examples 1
5 of the disilanyl organopolysiloxane obtained from 3
Take 100 g of each 0% toluene solution, add and mix 0.6% by weight of phosphoric acid, apply and impregnate a 0.02 mm-thick laminated mica piece so that the resin adhesion amount becomes 10%, and then 30 minutes Air dried. After air-drying, it was further pre-cured at 105 ° C. for 5 minutes, and this was 10 cm × 10 cm
Then, 10 sheets were stacked and pressed for 1 hour at 180 ° C. and 10 kg / cm ² to produce a silicone mica plate without thermal damage.

Further, the obtained silicone mica plate was
A laminate was prepared after-curing from 0 ° C. to 400 ° C. for 6 hours and after-curing from 200 ° C. to 600 ° C. for 6 hours.

Table 1 shows the physical properties of the organopolysiloxanes obtained from Examples 1 and 2 and Comparative Examples 1 to 3. Table 2 shows the properties of the laminate obtained by the above method.

[0050]

[Table 1] * GPC molecular weight measurement (polystyrene equivalent)

[0051]

[Table 2] * The rate of weight loss when immersed in water at 50 ° C. for 24 hours was less than 1%, and 1% or more was poor.

From the results shown in Table 2, the disilenyl organopolysiloxane obtained by using the combined use of an alkali fluoride or a dibasic organic acid and a metal condensation catalyst of the present invention as a hydrolysis condensation catalyst can be obtained by the conventional method. It was recognized that it had superior performance.

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kenichi Isobe 1-10 Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Silicone Electronics Materials Research Laboratory (56) References JP-A-6-228318 ( JP, A) JP-A-59-108033 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 77/48 C08G 77/08

Claims (1)

(57) [Claims] 1. The following general formula (1): R¹ _aSi_TwoX_6-a ... (1) (However, R¹ Is a hydrogen atom or a substituted or unsubstituted monovalent
X is a hydrocarbon group, and X is a hydrolyzable group. a is 0,
1, 2, or 3. ) A hydrolyzable group-containing di
Using silane and / or its partially hydrolyzed condensate as a catalyst
Alkali fluoride or dibasic organic acid and metal condensation catalyst
Wherein the hydrolysis and condensation using
Uniform composition formula (2) R¹ _cSi_Two(OR^Two)_dO_{(6-cd) / 2} ... (2) (However, R¹ Has the same meaning as above, and R^TwoIs a hydrogen atom
Or a substituted or unsubstituted monovalent hydrocarbon group. c,
d satisfies 0 ≦ c ≦ 3, 0 <d <6, 0 <c + d <6
It is a positive number. ) Dissilanyl organopolysilo
A method for producing a xan.