JPH0341116B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a primer composition, and particularly to a primer composition for firmly adhering silicone rubber to a metal surface or the like. (Prior Art) Silicone rubber has excellent physical and chemical properties and is widely used in various applications, but it is also used as a composite with metals, plastics, etc. However, regarding this composite, silicone rubber has poor adhesion to metals and plastics, so in the manufacture of this composite, vinyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, etc. Apply a primer composition consisting of an alkoxysilane having an unsaturated bond such as 3-methacryloxypropyltrimethoxysilane, a hydrolyzed condensate thereof, or a cohydrolyzed siloxane, a titanate ester, or a metal salt of an organic fatty acid. The method used is to then bond it with a cured silicone rubber material.
Even if this is done, the adhesive surface will not be able to maintain adhesion for a long time at high temperatures of 200°C or higher, for example.
It also has the disadvantage of causing a peeling phenomenon in hot oil. Therefore, regarding this type of primer composition, a rubber paste-like primer composition consisting of a vinyl group-containing organopolysiloxane, a polysiloxane resin, an alkoxysilane, an organic peroxide, and a catalyst has been proposed (Japanese Patent Publication No. 56-39817). Although this method improves adhesion at high temperatures and in high-temperature oil, it has the disadvantage that the composition is complex and requires a lot of labor and time in manufacturing. This process has the disadvantage that part or all of the primer layer may peel off due to the flow of the injected rubber compound, and furthermore, it has poor air drying properties and requires a certain amount of heat treatment to prevent the primer layer from flowing. There was also a disadvantage in terms of time and effort. Therefore, the present inventors previously proposed a primer composition containing an organosilicone polymer containing silazane bonds as a main ingredient (Japanese Patent Application No.
19774), although this method partially improves the above-mentioned drawbacks, the primer layer hardens very quickly during air-drying, and hardening is completed before the actual bonding process begins. , a phenomenon in which sufficient adhesion force is not developed during the adhesion operation, or conversely, the curing of the primer layer becomes extremely slow and the film easily flows even after being air-dried for more than a day, making it unsuitable for the intended adhesion operation. It may appear. (Structure of the Invention) The present invention relates to a primer composition that solves the above-mentioned disadvantages.

[Formula] (where R ¹ is a hydrogen atom or the same or different unsubstituted or substituted 1
valent hydrocarbon group, ^R2 is the same or different unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, X is an oxygen atom, NH group, alkylene group having 1 to 6 carbon atoms,
at least 10 selected from phenylene groups;
Atom or group in which % is NH group, a is 0.2 to 1.8,
b is 0 or a positive number of 1.8 or less), 100 parts by weight of a silazane bond-containing organosilicone polymer containing at least one unsaturated group in one molecule, 2) General formula R ² OH (R ² is the above) ) or the general formula (R ² O) _o S _i R ³ _4-o (where R ² is the same as above,
R ³ is mainly composed of alcohol or alkoxysilane represented by the same or different unsubstituted or substituted monovalent hydrocarbon group (n = 1 to 3) in an R ² OH equivalent amount of 0 to 30 parts by weight. That is. That is, as a result of various studies by the present inventors on improving the primer composition based on the silazane bond-containing organosilicone polymer proposed earlier, we found that the above-mentioned general formula for this silazane bond-containing organosilicone polymer

When it contains at least one unsaturated group in one molecule represented by the formula, its air drying properties are improved and it can have an appropriate curing speed, so it can be used in normal bonding processes. can have a longer pot life,
It was discovered that the coated surface could be sufficiently cured within a suitable time without baking treatment, and a coating film with excellent adhesive strength could be obtained. Among them, it is said that it is possible to obtain a primer composition that can be used for injection molding, transfer molding, etc., which require great pressure, because it provides a stable adhesive surface and the primer layer does not peel off or fall off due to the flow of the compound. After confirming this, the present invention was completed. The silazane bond-containing organosilicone polymer as the first component constituting the primer composition of the present invention has the general formula

[Formula], R ¹ is a hydrogen atom, a methyl group, an ethyl group, a propyl group,
Alkyl groups such as butyl groups, alkenyl groups such as vinyl groups and allyl groups, aryl groups such as phenyl groups and tolyl groups, cycloalkyl groups such as cyclohexyl groups, or part of the hydrogen atom bonded to the carbon atom of these groups. or a chloromethyl group completely substituted with a halogen atom, cyano group, etc., 3,3,
The composition is said to be the same or different type of unsubstituted or substituted monovalent hydrocarbon group selected from 3-trifluoropropyl group, cyanomethyl group, etc., and this composition can be used as a primer for firmly adhering silicone rubber to metal surfaces. Regarding R ¹ , it is desirable that the silicone rubber and the primer layer be chemically bonded when the silicone rubber is vulcanized with organic peroxide or addition reaction vulcanized. is required that at least one of them be an unsaturated group. Also, like R ¹ above, R ² is an unsubstituted or substituted monovalent hydrocarbon, especially one with 1 to 6 carbon atoms, and X is an oxygen atom, NH
an atom or a group selected from a group, an alkylene group having 1 to 6 carbon atoms, and a phenylene group, of which at least 10% must be an NH group, and a is 0.2 to 1.8. , b are assumed to be 0 or a positive number of 1.8 or less, and this includes the following unit formula CH ₂ =CHSi(NH) _{1.5 CH2} =CH− _CH2Si (NH) _1.5 Examples include compounds containing this unsaturated group, but examples of silazane compounds containing this unsaturated group include CH ₃ Si(NH) _1.5 , (CH ₃ O)CH ₃ Si(NH) _1.0 , C ₂ H ₅ Si(NH) _1.5 , ( _CH3 ) _{2Si (} NH) _1.0 , _C6H5Si (NH _{) 1.5} , _C2H5Si (NH) _1.5

[Formula] CF ₃ CH ₂ CH ₂ Si(NH) _1.5 HSi(NH) _1.5 It may be a copolymer with a silazane compound containing a unit formula such as 1.5. Next, the alcohol or alkoxysilane as the second component constituting this primer composition is optionally added when the (R ² O) group is reduced to zero in the silazane bond-containing organosilicone polymer as the first component. This component is represented by the general formula R ² OH or (R ² O) _o S _i R ³ _4-o , where R ² is the same unsubstituted or substituted monovalent hydrocarbon group as above, R ³ is also the same or different type of unsubstituted or substituted monovalent hydrocarbon group as ^R1 described above, and n is a positive number of 1 to 3, and examples of this alcohol include methyl alcohol, ethyl alcohol, n -propyl alcohol, iso-propyl alcohol, n-butanol, allyl alcohol, etc. Examples of the alkoxysilane include those shown by the following formula. ( _CH3O ) _Si ( _CH3 ) ₃ , (CH3O)2Si( _CH3 ) _{2 ,} ( _CH3O ) _{3SiCH3 ,} (C2H5O) _Si ( _CH3 ) _{3 ,} (CH _3O ) _3SiCH = _CH2 (CH ₃ O) ₃ Si(CH ₂ ) ₃ -NH, (CH ₃ OCH ₂ CH ₂ O) ₃ SiCH=CH ₂ The primer composition of the present invention includes the above first component and, if necessary, a second component. It can be obtained by adding a fixed amount of the second component to 100 parts by weight of the silazane bond-containing organosilicone polymer as the first component.
Alcohol and alkoxysilane as ingredients
If it is less than 0.5 parts by weight (calculated as R ² OH), air drying will be quick and the film will become hard, but the adhesive strength will drop rapidly in a short period of time, and if it is more than 30 parts by weight, the composition will harden at room temperature. 0.5 to 30 because it will run out and leave primer flow, making it virtually unusable.
The preferred range is 0.5 to 20 parts by weight. The primer composition of the present invention is usually used as an organic solvent solution, and therefore, it is suitable for use in toluene, xylene, petroleum ethers, ethers, chlorinated hydrocarbons such as dichloromethane, and esters such as acetate. It is used as a solution dissolved in ketones such as methyl ethyl ketone, siloxane compounds such as hexamethyldisiloxane and dimethylsiloxane cyclics, and the concentration thereof may be about 0.1 to 10% by weight. The primer composition of the present invention may be applied to the surface of various substrates to which adhesion with silicone rubber is desired, and the coating film not only adheres well to various substrates, but also reacts with moisture in the air. This gives a cured film with excellent adhesion to silicone rubber, which can be air-dried or heated for use. This cured film obtained by air drying or heating can be applied to a wide range of substrates such as metals, plastics, rubber, ceramics, etc., but it has particularly excellent adhesion to silicone rubber. , Specific applications include fixing rolls for dry copying machines, adhesion of pressure roll cores and rubber, laminating rolls in the plastics industry, adhesion of embossing roll cores and rubber, composite oil seals for automobiles, Examples include the manufacture of gaskets, and the manufacture of various sheets and belts based on metals, woven fabrics, etc. The most suitable silicone rubber is an organic peroxide vulcanized type containing silica or an addition reaction type, but it is not limited to these. It is effective in some cases, and this applies not only to silicone rubber but also to urethane rubber,
It can also be applied to non-silicone polymers such as polysulfide. In addition, in the primer composition of the present invention, the silanol group and silylamine group generated by its hydrolysis have extremely high activity, and furthermore, the effect of active hydrogen in the remaining silazane can be expected. It has the advantage of having a wider range of application and higher reliability than other compositions, but it has a group represented by (R ² O) in its molecule, In addition, since alcohol or alkoxysilane is added as a second component if necessary, the pot life is longer than that of conventional silazane-type primer compositions. Furthermore, it is useful in that it can sufficiently cope with seasonal changes such as humid periods and dry periods. Next, examples of the present invention will be given. Examples 1 to 3, Comparative Examples 1 to 3 _CH3Si (NH) _1.5 units 85 mol%, _CH2 =CHSi(NH) _1.5 units 5 mol%, A methanol-free dichloromethane solution containing 5% by weight of a silazane bond-containing organosilicone polymer consisting of 10 mol% units was prepared, and then methanol in the amount shown in Table 1 was added thereto to form six types of primer compositions. I made it. Next, this composition was tested as JIS H-4000A-1, 050P.
After 3 minutes, 10 minutes,
After 100 minutes and 3 days, a silicone rubber compound made by adding 0.6% by weight of dicumyl peroxide to silicone rubber KE555U [trade name manufactured by Shin-Etsu Chemical Co., Ltd.] was applied to the coated surface to a thickness of 2 mm. The air-drying property of the coating film in this case was determined by applying heat and pressure at a pressure of 30 kg/cm ² and a temperature of 165°C for 10 minutes to harden it.
The coating strength (apparent rigidity), the presence or absence of flow of the primer composition during press molding, and the adhesion of the molded body were examined, and the results shown in Table 1 were obtained.

[Table] ** Adhesion...○: Good, △: Partially peeled off, ×: Almost peeled off.
Example 4 Contains 3% of a silazane bond-containing organosilicone polymer containing _1.5 % by weight of methoxy groups consisting of _1.5 units of CH2=CHSi(NH) and _1.0 units of _CH2 =CH( _CH3O )Si(NH). When a primer composition consisting of a chloromethane solution was prepared and its adhesion was examined in the same manner as in Examples 1 to 3, the results shown in Table 2 below were obtained, which were fully satisfactory. I was wearing a kimono.

[Table] Example 5 CH ₃ Si (NH) _1.5 units 95 mol% A primer composition was prepared by diluting a composition obtained by adding 1.5% by weight of ethyl alcohol to a silazane bond-containing organosilicone polymer consisting of 5 mol% units with trichlorethylene to 5%, and using the same method as in Examples 1 to 3. When the adhesive properties were investigated, the results were almost the same as those shown in Table 2. Example 6 CH ₃ Si (NH) _1.5 units and 95 mol% A silazane bond-containing organosilicone polymer consisting of 5 mol% units was diluted to 5% with dichloromethane, and then 3.0% by weight of trimethoxyvinylsilane represented by (CH ₃ O) ₃ SiCH=CH ₂ was added to form a primer composition. When a product was made and its adhesive properties were examined, the results shown in Table 3 were obtained.

[Table] Example 7 The primer composition prepared in Example 5 was applied onto an aluminum core bar with a diameter of 30 mm and a length of 300 mm, and after 30 minutes of air drying and 2 days later, Example 1 was applied on top of the primer composition prepared in Example 5.
When the silicone rubber compound used in KE555U was injected to a thickness of 2 mm to make a roll for a dry copying machine, there was no flow of the primer layer at all, and the silicone rubber layer in the resulting roll was injected to a thickness of 2 mm. The adhesion between the metal core and the metal core was also good.

[Claims]

1. Mix paper and vinegar solution, stir, and leave to stand in a temperature range where bacteria can be active together with bacteria present in the raw materials, then filter the mixture, and mix the filtrate and polyester polyol at a temperature range where bacteria can be active. Stir, brew, and leave to stand to separate the first layer, the liquid phase, and the second layer.
An adhesive comprising a three-phase inclusive modified product of an ion-exchange semipermeable membrane liquid-viscous material having layers and a liquid-viscous material having a third phase, and a liquid-viscous material having a third phase obtained by separating the three-phase comprehensive modified product.