JPH0231114B2 - SHIRIKOONSOSEIBUTSU - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a silicone composition, and particularly to a silicone composition containing a novel addition reaction control agent and having excellent workability and curing properties. (Prior art) Silicone compositions include an organopolysiloxane containing an aliphatic unsaturated group bonded to a silicon atom and a hydrogen atom bonded to a silicon atom (≡SiH
A so-called addition reaction type composition is widely used, in which an organohydrodiene polysiloxane containing (bond) is reacted in the presence of a noble metal catalyst, but this composition has a short pot life and balances curability. Since this is not easy, there are methods in which acetylene alcohols are added as a reaction control agent (see U.S. Pat. No. 3,445,420), and acrylonitrile is added (see U.S. Pat. No. 3,344,111, Japanese Patent Publication No. 45-22018). (see US Pat. No. 4,256,870), and those to which maleates are added (see US Pat. No. 4,256,870) have been proposed. However, this acetylene alcohol is ≡SiH
Because of its reactivity with bonds, compositions containing it have the disadvantage that over time the ≡SiH bonds as curing agent functional groups are consumed during storage, resulting in a decrease in curing properties. It has a weak effect and has almost no effect when added in small amounts, and when used in large amounts, the composition has poor curing, and has a special odor, which causes environmental problems. Since maleates have similar disadvantages, none of these are satisfactory, and there is a growing need for new control agents that improve on these points. (Structure of the Invention) The present invention relates to a silicone composition to which a novel reaction control agent is added, which solves the above-mentioned disadvantages.
100 parts by weight of an organopolysiloxane containing an aliphatic unsaturated group bonded to at least two silicon atoms; Empolysiloxane 0.1-20 parts by weight, 3) Platinum or platinum-based compound 0.0001-0.1 parts by weight, 4)
It is characterized in that it consists of 0.0001 to 5.0 parts by weight of C ₂ H ₅ CH=CHCN. That is, as a result of various studies on reaction control agents for addition reaction type silicone compositions, the present inventors found that one of the nitrile compounds as this control agent.
We discovered that a composition with a long pot life and excellent curability can be obtained by selectively using 2-pentenenitrile, which has the formula C ₂ H ₅ CH=CHCN as a seed, and we are proceeding with research on the amount of 2-pentenenitrile added. The present invention has been completed. The organopolysiloxane as the first component constituting the composition of the present invention contains at least 1 organopolysiloxane per molecule.
It has an aliphatic unsaturated group bonded to silicon atoms. Therefore this is the formula

[Formula], R ¹ is a vinyl group, an allyl group,

[Formula] CH ₂ = unsaturated group selected from CHCOOR ³ - (R ³ is a divalent organic group), R ² is an alkyl group such as methyl, ethyl, propyl, butyl, phenyl, tolyl group aryl groups such as cycloalkyl groups such as cyclohexyl groups, or chloromethyl groups in which part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyano groups, mercapto groups, etc., 3,3, The same or different unsubstituted or substituted monovalent saturated hydrocarbon groups selected from 3-trifluoropropyl group, cyanomethyl group, etc., preferably at least 50 mol% of which are methyl groups, and a is 0<a ≦3, b is 0≦b≦
3, where 0<a+b<4, and this organopolysiloxane is preferably linear and both ends of the molecular chain are blocked with vinylsilyl groups, but this terminal vinyl group has a plurality of or the unsaturated group such as the vinyl group may be included in the chain. Also mentioned above
The organic group represented by R ² may be a phenyl group, a phenylethyl group, an ethyl group, a propyl group, etc. other than a methyl group. Next, the organohydrodiene polysiloxane as the second component must contain at least two silicon-bonded hydrogen atoms (≡SiH bonds) in its molecule. Therefore this is the formula

[Formula], R ⁴ is the same or different unsubstituted or substituted monovalent saturated hydrocarbon group as R ² described above, and c is 0≦o≦
3, d is an organohydrodiene polysiloxane where 0<d<3. In addition, since this organohydrodiene polysiloxane acts as a crosslinking agent for the organopolysiloxane as the first component, it must be compatible with this first component. Although it is assumed that the molecular weight is lower than that of the first component, from the viewpoint of reactivity, it is preferable that the ≡SiH bond accounts for 50% or more of the total silicon number.
If the amount of organohydrodiene polysiloxane added is less than 0.1 part by weight per 100 parts by weight of the organopolysiloxane as the first component, this addition reaction will be insufficient, and if it is more than 20 parts by weight, the resulting film will become brittle. However, since excess ≡SiH bonds may remain and cause deterioration over time, the amount is set in the range of 0.1 to 20 parts by weight, but the preferred range is 1 to 10 parts by weight.
Parts by weight. The platinum or platinum compound as the third component may be a known addition reaction catalyst, including platinum black, platinum supported on silica, carbon black, etc., chloroplatinic acid, chloroplatinic acid, etc. Examples include alcohol solutions, complex salts of chloroplatinic acid, olefin, and vinyl siloxane. The amount added varies depending on the combination of the first component and the second component, but is usually in the range of 0.0001 to 0.1 part by weight per 100 parts by weight of the first component. The fourth component in the composition of the present invention is a novel control agent for controlling the reaction of the silicone composition consisting of the first to third components described above.
It is considered to be 2-pentenenitrile represented by C ₂ H ₅ CH=CHCN. Although this substance has rarely been used commercially in the past, the present inventors have discovered its usefulness as a control agent for addition reaction type silicone compositions. Addition-reactive silicone compositions containing compounds have the advantage of having improved storage stability at room temperature and a longer pot life.
It also has excellent curability, and is advantageous in that there is no oxygen inhibition even when it is cured by ultraviolet irradiation, making it possible to cure a thin film. The amount of the fourth component to be added may be adjusted according to the desired control time in the same way as the third component, but normally, if it is less than 0.0001 parts by weight per 100 parts by weight of the first component, its effect will not be clear. However, if it exceeds 5.0 parts by weight, the volatile content will increase and curing will be inhibited.
It should be in the range of 0.0001 to 5.0 parts by weight, but
This preferred range is from 0.01 to 1 part by weight. The silicone composition of the present invention can be obtained by uniformly mixing predetermined amounts of the first to fourth components described above. or silicone oil, or organic polymers such as isobutylene oligomers, and cellulose derivatives to impart writability to the silicone film made from this composition, as well as silica as a filler, titanium white, and dyes as colorants. , pigments, co-reactive low-molecular-weight siloxanes whose molecular chain ends are capped with hydroxyl groups as film modifiers, etc. may be added, but these are preferably added in an amount of 10% or less of the total amount. Although the silicone composition of the present invention can be used in all the applications for which compositions of this type have been used, it is particularly useful for mold release. Next, examples of the present invention will be given, in which parts are parts by weight, and viscosity is a value measured at 25°C. Example 1, Comparative Examples 1 to 4 Both ends of the molecular chain are blocked with dimethylvinylsilyl groups, the following formula Both ends of the molecular chain are blocked with trimethylsilyl groups in 100 parts of dimethylpolysiloxane with a viscosity of 1500 cS, as shown by the following formula: 2.0 parts of methylhydrodiene polysiloxane with a viscosity of 30 cS, 0.2 parts of a butyl alcohol solution of chloroplatinic acid (platinum content 5% by weight) and 2 parts of
-0.2 parts of pentenenitrile was added and mixed uniformly to prepare silicone composition A with a viscosity of 900 cS. Next, this composition was applied to polyethylene laminated paper at a coating amount of 0.8 g/m ² and cured by heat treatment at 150°C for 30 seconds in a hot air dryer.
The condition of this cured film was examined, and the condition of the cured film was also examined after the composition was left to stand for 5 hours in the same manner, and the results shown in Table 1 were obtained. Next, for comparison, silicone compositions B to E were prepared in which acrylonitrile, 3-pentenenitrile, and acetylene alcohol were added in place of 2-pentenenitrile in the above, and without adding a control agent, and silicone compositions B to E were prepared in the same manner as above. After processing,
The results shown in Table 1 were obtained.

[Table] (Notes) Cure property: ○...The film does not fall off and does not become cloudy even when the coated surface is rubbed with fingers.
〓
〓×…It becomes noticeably cloudy.
Example 2 Both ends of the molecular chain are blocked with trivinylsilyl groups, the following formula 100 parts of dimethylvinylpolysiloxane with a viscosity of 10,000cS, represented by the following formula, is obtained by capping both molecular chain ends with dimethylvinylsilyl groups. 2.0 parts of methylhydrodiene polysiloxane with a viscosity of 30 cS, 1.0 parts of a complex salt of chloroplatinic acid and vinylsiloxane (platinum content 0.3% by weight),
The following formula in which 0.05 part of 2-pentenenitrile and both ends of the molecular chain are blocked with trimethylsilyl groups When 10.0 parts of dimethylpolysiloxane with a viscosity of 1500 cS was added and mixed uniformly, the viscosity was
A mold release silicone composition of 7000 cS was obtained. Next, this composition was applied to polyethylene laminated paper at a coating amount of 0.8 g/m ² and cured by heating at 80°C for 30 seconds in a dryer to examine its curing properties. Apply acrylic adhesive Olivine BPS-8170 (trade name manufactured by Toyo Ink Manufacturing Co., Ltd.) to the surface and heat it for 30 minutes at 100℃.
After heat treatment for a minute, a laminated paper was laminated to this treated surface, and after aging, the laminated paper was pulled at an angle of 180° using a tensile tester to measure the peeling force, and the results are shown in Table 2. The same results were obtained, and a similar test was conducted after leaving this composition for 5 hours.
The viscosity had increased to 8000cS, but its curing properties
The peeling force showed the results as shown in Table 2.

[Table] Example 3 Both ends of the molecular chain are blocked with methylphenylvinylsilyl groups, the following formula 100 parts of dimethyldiphenylpolysiloxane with a viscosity of 3000cS is added with the following formula:

2.5 parts of methylhydrodiene polysiloxane with formula 1000cS, complex salt of chloroplatinic acid and vinylsiloxane (platinum content 0.3% by weight)
Add 1.0 part and 0.5 part of 2-pentenenitrile,
By uniformly mixing them, a mold release silicone composition with a viscosity of 2800 cS was prepared. Next, this composition was applied to polyethylene laminate paper at a coating amount of 0.6 g/m ² , and then
This was irradiated with ultraviolet rays from a 160W ultraviolet irradiator for 1 second from a distance of 8 cm to examine its curing properties, and its peeling force was examined in the same manner as in Example 2, and the composition was left to stand for 5 hours. When similar tests were conducted later, the results shown in Table 3 were obtained.

【table】

Claims (1)

[Claims] 1 1 Organopolysiloxane containing an aliphatic unsaturated group bonded to at least one silicon atom in one molecule 100 parts by weight 2 Bonded to at least two silicon atoms in one molecule Organohydrodiene polysiloxane containing hydrogen atoms (≡SiH bonds)
A silicone composition comprising: 0.1 to 20 parts by weight, 3 platinum or a platinum-based compound, 0.0001 to 0.1 parts by weight, and 4 C ₂ H ₅ CH=CHCN 0.0001 to 5.0 parts by weight.