JP3324284B2 - Adhesive silicone composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive silicone composition having excellent adhesion to various organic resins and metals.

[0002]

2. Description of the Related Art
As a method of bonding the addition-curable silicone rubber and the organic resin, for example, a method in which a primer is applied to the surface of a molding resin, and an uncured silicone rubber is applied thereon and cured and adhered, and a self-adhesive silicone rubber material is used. A method of curing the resin from above has been proposed.
Further, with respect to this self-adhesive silicone rubber composition, in particular, a large number of compositions using the adhesive component as a framework have been proposed. Specifically, Japanese Patent Application Laid-Open No. 54-80358 discloses aminoalkoxysilanes and epoxyalkoxysilanes. JP-B-53-21026 discloses a partial addition product of an alkoxysilyl group to hydrogenated polysiloxane, and JP-A-54-48853 discloses an acryltrialkoxysilane to a hydrogenated siloxane cyclic substance. Addenda,
JP-B-51-33540 discloses an epoxy adduct to hydrogenated siloxane, JP-B-45-23354 discloses an alkoxysilane adduct to triallyl isocyanurate, and JP-A-54-37157 discloses a glycidyl-containing product. The use of compounds and acid anhydrides is disclosed.

[0003] However, self-adhesive silicone rubber compositions using these adhesive components have been improved in adhesion to metals and some resins and can withstand full use, but have recently been used in various industries. However, it cannot be said that it has sufficient adhesiveness to plastics, especially nylon, polycarbonate, acrylic resin and the like.

The present invention has been made in order to solve the above problems, and has an adhesive silicone composition excellent in adhesion to various metals, and further to various resins, especially plastics such as nylon, polycarbonate and acrylic resin. The purpose is to provide.

[0005]

The present inventors have made intensive studies to achieve the above object, and as a result, have found that an alkenyl group-containing organopolysiloxane has the following general formula (1):
(2) An organohydrogenpolysiloxane having at least three hydrogen atoms directly bonded to silicon atoms in one molecule selected from (3) and at least one aliphatic unsaturated group in one molecule, And a phenylene skeleton of 2
By compounding a compound having at least one compound with platinum or a platinum-based compound, the adhesiveness to various metals is excellent,
It has been found that it is possible to obtain an adhesive silicone composition which is excellent in adhesiveness to various organic resins, and in particular, can be favorably adhered to plastics such as nylon, polycarbonate, acrylic resin and the like, which were conventionally regarded as poorly adhesive resins.

[0006]

Embedded image (Wherein, R is a halogen-substituted, cyano-substituted or unsubstituted alkyl group, aryl group or aralkyl group. In the general formula (3), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group. N is an integer of 3 or more, and h is 3 or 4.)

That is, the present inventors have found that one molecule contains at least one aliphatic unsaturated group and that the phenylene skeleton has two
The compound having more than one compound shows an extremely interesting behavior that, when used alone in the silicone composition, adheres only to the organic resin and does not adhere to the metal, and is selected from the above formulas (1) to (3). When used together with SiH group-containing organohydrogenpolysiloxane, it can surprisingly adhere well to various organic resins, especially with conventional addition-curable silicone rubber adhesives such as plastics such as nylon, polycarbonate and acrylic resin. Adhesion to organic resins, which has been difficult, becomes possible, and it also shows excellent adhesion to various metals. Further, these compounds have been considered to be effective for the adhesion in addition-curable silicone rubber adhesives. When a compound having a SiH group and an alkoxysilyl group and / or a glycidyl group in a molecule is used in combination, the adhesiveness is improved. It was found that could be improved, leading to the completion of the present invention.

Accordingly, the present invention provides (A) an alkenyl group-containing organopolysiloxane, and (B) a hydrogen atom directly bonded to a silicon atom in one molecule selected from the above general formulas (1), (2) and (3). (C) a compound represented by the following general formula (5) having at least one aliphatic unsaturated group in one molecule and having two or more phenylene skeletons, And (D) an adhesive silicone composition containing platinum or a platinum-based compound.

Now, the present invention will be described in further detail. The alkenyl group-containing organopolysiloxane as the first component of the adhesive silicone composition of the present invention preferably has a viscosity at 25 ° C. of 100 to 500,000 cp. ,
A known organopolysiloxane which is generally used as a main raw material of an addition-curable silicone rubber, one represented by the following general formula (4) is preferably used.

R ¹ _a SiO _{(4-a) / 2} (4) (wherein R ¹ is a substituted or unsubstituted monovalent hydrocarbon group, and a is in the range of 1.9 to 2.4) is there.)

In the above formula (4), R ¹ preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl group, hexyl group, cyclohexyl group, alkyl group such as octyl group, vinyl group,
Allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group, alkenyl group such as cyclohexenyl group, phenyl group, tolyl group, aryl group such as xylyl group, benzyl group, aralkyl group such as phenylethyl group,
Some or all of the hydrogen atoms of these groups are halogen atoms,
Examples include groups selected from halogen-substituted groups such as a chloromethyl group, a cyanoethyl group, and a 3,3,3-trifluoropropyl group substituted with a cyano group, and a hydrocarbon group substituted with a cyano group. Each substituent R ¹ may be different or the same, but it is necessary that the molecule contains one or more alkenyl groups, preferably 2 to 10 alkenyl groups. Incidentally, the substituent of the silicon atom may be basically any of the above, particularly, a vinyl group or an allyl group as the alkenyl group, a methyl group as the other substituent,
The introduction of a phenyl group or a trifluoropropyl group is preferred. Further, the organopolysiloxane may be linear or branched containing R ¹ SiO _3/2 units or SiO _4/2 units.

Specific examples of the organopolysiloxane of the above formula (4) include the following compounds.

[0013]

Embedded image (Wherein, R ¹ is the same as described above (excluding the aliphatic unsaturated hydrocarbon group), k is 60 to 1500, and m is 1
~ 300. )

The organopolysiloxane of the above formula (4) can be easily produced by a known method, for example, by equilibrating an organocyclopolysiloxane and a hexaorganodisiloxane in the presence of an alkali or acid catalyst. Can be.

Next, the organohydrogenpolysiloxane, which is the second component of the present invention, is represented by the following formulas (1) to (3) and acts as a crosslinking agent that reacts with the first component. By coexisting with the compound of the third component described below, the adhesiveness of the composition can be improved.

[0016]

Embedded image (Wherein, R is a halogen-substituted, cyano-substituted or unsubstituted alkyl group, aryl group or aralkyl group. In the general formula (3), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group. N is an integer of 3 or more, and h is 3 or 4.)

In the above formulas (1) and (2), R preferably has 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms, for example, methyl, ethyl, propyl, isopropyl,
Butyl, t-butyl, hexyl, cyclohexyl, alkyl such as octyl, aryl such as phenyl, tolyl, xylyl, aralkyl such as benzyl, phenylethyl, chloromethyl, cyanoethyl And 3,3,3-trifluoropropyl groups. In addition, each substituent R may be different or the same. H is 3 or 4, and n is 3 or more, and preferably 3 to 50. In addition, the specific example of a C1-C6 alkyl group of Formula (3) is the same as the above (however, except an octyl group).

[0018] Of the organohydrogenpolysiloxanes of the above formulas (1) to (3), those of the formula (1) or (2) are preferably used especially when the pot life is required. .

The amount of the above-mentioned organohydrogenpolysiloxane is determined based on the amount of the organopolysiloxane 10 as the first component.
1 to 20 parts, particularly 1
It is preferable to set it to 5 parts. If the addition amount is less than 1 part, the expression of adhesiveness may not be sufficient, and if it exceeds 20 parts, hydrogen gas may be generated during storage, and the risk of foaming may occur even during curing.

Further, when the above-mentioned organohydrogenpolysiloxane is added, the equivalent of the hydrogen atom bonded to the silicon atom is 0.1 to one aliphatic unsaturated group contained in the first component and the third component. 4 to 10 equivalents, especially 0.8 to 5
It is desirable that the amount be equivalent. If the added amount is less than 0.4 equivalent, the curing is insufficient, and the mechanical strength may be inferior.
May cause aging.

In the present invention, in addition to the above-mentioned organohydrogenpolysiloxane, a hydrogenpolygen represented by the following formula, which is usually blended into an addition-curable silicone composition, in order to supplement the curing speed and the hardness after curing. Siloxane may be added. The addition amount of the hydrogen polysiloxane is in the range of 0.5 to 10 parts.

[0022]

Embedded image (Where R ¹ is the same as above, p is 3 or more, preferably an integer of 3 to 50, q is 1 or more, preferably 1 to
It is an integer of 150, and p + q is 4-300, preferably 4-200. )

The third component of the present invention is a compound containing at least one aliphatic unsaturated group in one molecule and having two or more phenylene skeletons. This compound is an essential component for exhibiting adhesiveness in the presence of the second component, organohydrogenpolysiloxane, as an adhesive component.

As the compound containing an aliphatic unsaturated group and a phenylene skeleton, a compound represented by the following general formula (5), more preferably a compound represented by the following general formula (6) is used.

[0025]

Embedded image However, R ² is a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an aryl group, an alkenyl group, an alkoxy group or an alkenyloxy group, or an alkenyl group, an alkoxy group, a glycidyl group, a carbonyl group, a carbonyloxy group,
A monovalent organic group containing a silyloxy group or an alkoxysilyl group (excluding those containing a SiH group),
At least one of R ^2, is preferably 1-4, more preferably 1 or 2 is alkenyl or alkenyl group-containing monovalent organic group. X is the following group (R ³ is a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkenyl group or an alkynyl group, s is 2 or more, preferably a positive number of 2 to 4), and r is 0 or It is one.

In this case, in R ² or R ³ , the alkyl group and the alkoxy group have 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and the aryl group has 6 carbon atoms.
-10, preferably 6-8, the alkenyl group, alkynyl group and alkenyloxy group preferably have 2 to 10 carbon atoms, preferably 2 to 8, more preferably 2 to 6,
The monovalent organic group preferably has 1 to 12, preferably 2 to 10, more preferably 2 to 8 carbon atoms.

Examples of the alkyl group, alkenyl group and aryl group are the same as those exemplified for R described in formulas (1) to (3), and the alkynyl group is an acetylene group. . Examples of the alkoxy group and alkenyloxy group include methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, methoxyethoxy, ethoxyethoxy, vinyloxy, allyloxy, propenoxy, isopropenoxy, and butenoxy. Further, an alkenyl group,
Examples of the monovalent organic group including an alkoxy group, a glycidyl group, a carbonyl group, a carbonyloxy group, a silyloxy group, and an alkoxysilyl group include the following.

[0028]

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[0029]

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However, R ⁴ is a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group having 1 to 10, preferably 1 to 8, more preferably 1 to 6, or 2 to 10, preferably 2 to 8 carbon atoms. And more preferably 2 to 6 alkenyl groups. R ⁵ is an alkenyl group having 2 to 12 carbon atoms, preferably 2 to 10 carbon atoms, an alkenyl group-containing monovalent organic group, —R ⁶ _t —S
iR ⁷ or indicates -CO-R ^7, R ⁶ is 1 to 6 carbon atoms, preferably 1 to 4 alkylene group, t is 0 or 1, R ⁷ is an alkyl group having 1 to 6 carbon atoms, 2 carbon atoms Alkenyl group having 1 to 6 carbon atoms or alkoxy group having 1 to 6 carbon atoms, and one or both of R ⁵ is an alkenyl group or a monovalent organic group containing an alkenyl group. Note that X and r have the same meaning as described above.

The alkyl group, alkenyl group and alkenyl group-containing monovalent organic group include those exemplified above as R ² , and the alkylene group includes a methylene group, an ethylene group and a trimethylene group. , Tetramethylene group, hexamethylene group, methylethylene group and the like.

The following can be mentioned as such compounds.

[0033]

Embedded image

The third component is not limited to those described above, and those having three or more phenyl groups can be used.

The compounding amount of the compound containing an aliphatic unsaturated group and a phenylene skeleton is preferably from 0.1 to 20 parts, more preferably less than 0.1 part, based on 100 parts of the organopolysiloxane of the first component. When the amount exceeds 20 parts, the cured product becomes hard and brittle.

In the present invention, in addition to the second and third components, one molecule conventionally used as an adhesive component contains Si.
A compound having an H group and an alkoxysilyl group and / or a glycidyl group, in particular, a cyclic or chain organopolysiloxane can be added, whereby the adhesion to various metals and organic resins can be further improved or the adhesion can be improved. Target substances can be increased. Examples of the organopolysiloxane compound having an alkoxysilyl group and / or a glycidyl group and a SiH group in the molecule include the following.

[0037]

Embedded image

[0038]

Embedded image

The amount of the compound having an alkoxysilyl group, glycidyl group or the like is in the range of 0.1 to 20 parts based on 100 parts of the first component organopolysiloxane.

Further, in the present invention, platinum or a platinum compound is blended as the fourth component. This platinum or platinum-based compound is used as a catalyst for accelerating the curing addition reaction (hydrosilation) between the first component and the second component, and specifically, platinum black, chloroplatinic acid And alcohol-modified chloroplatinic acid, and complexes of chloroplatinic acid with various olefins, aldehydes, vinylsiloxanes, acetylene alcohols, and the like.

The amount of platinum or platinum-based compound added may be appropriately increased or decreased according to the desired curing rate, but is preferably 0.1 to 1000 ppm, more preferably 1 to 2 ppm of platinum, based on the whole composition.
A range of 00 ppm is preferred.

The silicone composition of the present invention may contain other optional components in addition to the above essential components. For example, when it is necessary to impart strength to the composition, quartz powder, diatomaceous earth, calcium carbonate, alumina,
It is effective to add a quasi-reinforcing filler such as carbon black and a reinforcing filler such as finely divided silica. Specific examples of the reinforcing filler include Aerosil 130, 200, and 300 (manufactured by Nippon Aerosil Co., Ltd. and Degussa Co.), and Cabosil as hydrophilic silica.
MS-5, MS-7 (Cabot), Rheoro
sil QS-102, 103 (manufactured by Tokuyama Soda Co., Ltd.), Ni
psil LP (manufactured by Nippon Silica Co., Ltd.), and Aerosil R-812, R-81 as hydrophobic silica.
2S, R-972, R-974 (Degussa), Rheosil MT-10 (Tokuyama Soda), Nipsil SS series (Nippon Silica)
Etc. are exemplified. The amount of these fillers is 10
A range of ~ 150 parts is preferred.

Further, in order to make these materials practical,
When it is necessary to adjust the curing time, a vinyl group-containing organopolysiloxane such as vinylcyclotetrasiloxane as a control agent, triallyl isocyanurate, alkyl maleate, acetylene alcohols and their silanes, siloxane modified products, Compounds selected from the group consisting of hydroperoxide, tetramethylethylenediamine, benzotriazole and mixtures thereof may be used.

It is also possible to add an inorganic pigment such as cobalt blue, a coloring agent such as an organic dye, and a heat-resistant and flame-retardant improver such as cerium oxide, zinc carbonate, manganese carbonate, red iron oxide, titanium oxide and carbon black. It is.

As conditions for curing the composition of the present invention, a temperature of 60 to 200 ° C. and a heating time of 5 minutes to 5 hours can be employed.

[0046]

The adhesive silicone composition of the present invention has excellent adhesiveness to various metals and also to various organic resins, especially nylon and polycarbonate, which have been regarded as difficult-to-adhere resins. , PBT, acrylic resin, and other plastics, and can be widely used as an adhesive.

[0047]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. All parts in each example are parts by weight.

Examples and Comparative Examples Both ends were blocked with a dimethylvinylsilyl group and the viscosity at 25 ° C. was 10,000.
cp polydimethylsiloxane 100 parts, specific surface area 3
40 parts of fumed silica of 00 cm ² / g, 8 parts of hexamethyldisilazane, and 1 part of water were charged into a kneader, and the mixture was stirred and mixed at room temperature for 1 hour. went. Then, the mixture is cooled to room temperature,
Further 20 parts of polydimethylsiloxane having a viscosity of 10,000 cp at 25 ° C., both ends of which are blocked with dimethylvinylsilyl group, 20 parts of acetylene alcohol to extend the time until curing at room temperature, 0.1 part of platinum vinylsiloxane The complex was added at 50 ppm as a platinum atom and mixed well until it became homogeneous.

Next, as shown in Table 1, methyl hydrogen polysiloxane represented by the following formula and an adhesive component (compound containing an aliphatic unsaturated group and a phenylene skeleton) were added to 100 parts of the composition comprising the above mixture. Thus, six types of silicone rubber compositions shown in Table 1 were obtained. The obtained silicone rubber composition was placed on a plate of various objects to be bonded, cured at 120 ° C. for 1 hour, and the adhesiveness of each was examined. In this case, the adhesiveness was cut 15 mm between the cured product and the plate with a knife, and the cut piece was 180 °
It was examined by pulling with a peel and observing the adhesive interface.

[0050]

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[0051]

[Table 1]

[Example 1] Polycarbonate resin, PB
Using T, aluminum, and chromium as the objects to be bonded, the adhesiveness of the composition of Example 1 was examined. As a result, it showed excellent adhesiveness to any of the above objects to be bonded.

Example 2 As a result of examining the adhesion of the composition of Example 2 to a nylon resin, excellent adhesion was shown. It also exhibited excellent adhesion to aluminum and chromium.

Example 3 As a result of examining the adhesion of the composition of Example 3 to an acrylic resin, excellent adhesion was shown. Furthermore, the results of examining the adhesion to the polycarbonate resin and PBT also showed excellent adhesion. It also exhibited excellent adhesion to aluminum and chromium.

Example 4 Polycarbonate resin, PB
Using T, aluminum, and chromium as the objects to be bonded, the adhesiveness of the composition of Example 4 was examined. As a result, it showed excellent adhesiveness to any of the above objects to be bonded.

[Comparative Example 1] Polycarbonate resin, PB
T, aluminum, and chromium were used as objects to be bonded, and the adhesion of the composition of Comparative Example 1 was examined. As a result, it showed excellent adhesiveness to aluminum, but the other objects to be bonded easily peeled off at the interface. In addition, the adhesiveness to acrylic resin and nylon resin was examined, but both were peeled off at the interface, and the adhesiveness was poor.

Comparative Example 2 Polycarbonate resin, PB
T, aluminum, and chromium were used as objects to be bonded, and the adhesion of the composition of Comparative Example 2 was examined. As a result, any of the objects to be bonded easily peeled off at the interface. In addition, the adhesiveness to acrylic resin and nylon resin was examined, but both were peeled off at the interface, and the adhesiveness was poor.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mikio Shiono 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Inside Silicone Electronics Materials Research Laboratory Shin-Etsu Chemical Co., Ltd. (72) Inventor Masayuki Ikeno Matsui, Usui-gun, Gunma Prefecture Hitomi Tamachi 1-10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (56) References JP-A-6-12738 (JP, A) JP-A-56-155257 (JP, A) JP-A-3 JP-163183 (JP, A) JP-A-64-87661 (JP, A) JP-A-4-126787 (JP, A) JP-A-52-126455 (JP, A) (58) Fields investigated (Int. . ^7, DB name) C09J 183/00 - 201/10

Claims (4)

(57) [Claims] (A) an alkenyl group-containing organopolysiloxane; (B) at least three hydrogen atoms directly bonded to silicon atoms in one molecule selected from the following general formulas (1), (2) and (3): An organohydrogenpolysiloxane having the following formula: (Wherein, R is a halogen-substituted, cyano-substituted or unsubstituted alkyl group, aryl group or aralkyl group. In the general formula (3), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group. N is an integer of 3 or more, and h is 3 or 4.) (C) The following general formula (1) containing at least one aliphatic unsaturated group in one molecule and having two or more phenylene skeletons: A compound represented by 5), [However, R ² represents a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an aryl group, an alkenyl group, an alkoxy group or an alkenyloxy group, or an alkenyl group, an alkoxy group, a glycidyl group, a carbonyl group, a carbonyloxy group, a silyloxy group or an alkoxy group. It is a monovalent organic group containing a silyl group (excluding those containing a SiH group)
Wherein at least one of R ² is an alkenyl group or a monovalent organic group containing an alkenyl group. X is the following group (R ³ is a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkenyl group or an alkynyl group, and s is a positive number of 2 or more.), And r is 0 or 1. ] And (D) platinum or a platinum-based compound. 2. The composition according to claim 1, wherein the component (C) is represented by the following general formula (6). Embedded image (However, R ⁴ represents a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. R ⁵ represents an alkenyl group having 2 to 12 carbon atoms,
An alkenyl group-containing monovalent organic group, —R ⁶ _t —SiR ⁷
Or shows a -CO-R ^7, R ⁶ is a number from 1 to 6 alkylene group, t is 0 or 1, R ⁷ is an alkyl group having 1 to 6 carbon atoms, an alkenyl group, or a carbon number of 2 to 6 carbon atoms atoms Among the alkoxy groups 1 to 6, one or both of R ⁵ are an alkenyl group or a monovalent organic group containing an alkenyl group. X and r have the same meaning as described above. ) 3. The composition according to claim 1, wherein an organopolysiloxane containing a SiH group and an alkoxysilyl group and / or a glycidyl group in the molecule is blended. 4. The composition according to claim 1, which is used for bonding to nylon, polycarbonate, polybutylene terephthalate or acrylic resin or metal.