JP3102284B2 - Adhesive silicone composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a self-adhesive silicone composition.

[0002]

2. Description of the Related Art Various kinds of adhesives such as polyurethane resin, acrylic resin, silicone and the like have been conventionally used for bonding various electric and electronic parts and for bonding a sealant for construction. In this case, silicone-based adhesives are preferred because they are excellent in heat resistance, weather resistance, electrical properties, and relaxation of stress caused by heating and cooling.

[0003] Many proposals have been made to improve the adhesiveness of such silicone adhesives. For example, an organopolysiloxane having a trialkoxysilyl group and a hydrogen atom bonded to a silicon atom (JP-A-48-169)
No. 52), an organopolysiloxane having a hydrogen atom bonded to a silicon atom and an ester group and / or a glycidyl group (see JP-A-50-39345), aminoalkylalkoxysilane and glycidoxyalkylalkoxysilane. Reaction product (JP-B-52-8854)
No., JP-B-55-41702) is proposed as an adhesion promoter.

[0004]

However, none of the above-mentioned prior art proposals still has a satisfactory adhesiveness, and in particular, has poor adhesiveness to plastics.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an adhesive silicone composition having sufficient adhesiveness to plastics.

[0006]

The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that an addition-curable silicone composition is represented by the following general formula (1) as an adhesion promoter. It has been found that, by blending the fluorinated organosilicon compound represented by the formula, good adhesion to plastics, which has been difficult to bond conventionally, is exhibited, and the present invention has been accomplished.

[0007]

Embedded image

Wherein R _f is a perfluoroalkylene group or a perfluorooxyalkylene group, R ¹ is an alkylene group having 1 to 12 carbon atoms, an arylene group or —C
H ₂ -C ₆ H ₄ - group, or -R'NHR '- (. R' is showing the C ₂ H ₄ or C ₃ H ₆ alone respectively), R ² is 1 to the number of carbon atoms
10 alkyl groups, aryl groups, alkenyl groups, aralkyl groups, or groups in which part or all of the hydrogen atoms of these groups have been substituted with halogen atoms, R ³ is an alkyl group or an alkoxyalkyl group, and n is 0 to 3 Indicates an integer. ]

Accordingly, the present invention provides (a) a diorganopolysiloxane containing an average of two or more alkenyl groups bonded to silicon atoms in one molecule, and (b) a hydrogen atom bonded to silicon atoms in one molecule. An organohydrogenpolysiloxane containing an average of 3 or more, (c) an addition reaction catalyst,
(D) An adhesive silicone composition comprising the fluorine-containing organosilicon compound represented by the general formula (1).

Hereinafter, the present invention will be described in more detail. The adhesive silicone composition of the present invention is obtained by adding the above formula (1) to the addition-curable silicone composition containing the components (a) to (c) as described above. ) Is blended.

Here, the diorganopolysiloxane of the component (A) is a base component of the composition of the present invention,
It may be branched or a mixture thereof, but usually, the main chain portion of the molecular chain is composed of repeating diorganosiloxane units, and the molecular chain end is blocked with a triorganosiloxy group. In general, This diorganopolysiloxane needs to have an alkenyl group bonded to two or more silicon atoms on average in one molecule, and such an alkenyl group may be present at the terminal of a molecular chain, May be present, but it is preferable to have one present at the terminal of the molecular chain from the viewpoint of the curing speed of the composition, the physical properties of the cured product, and the like.

As the diorganopolysiloxane of the component (a), those represented by the following general composition formula (2) are preferably used.

R ⁴ _a R ⁵ _b SiO _{(4-ab) / 2} (2)

In the formula, R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group having no aliphatic unsaturated bond, and is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, -Alkyl group such as butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, decyl group, aryl group such as phenyl group, tolyl group, xylyl group, naphthyl group, benzyl group, 2- Phenylethyl group, 3-phenylpropyl group,
Aralkyl groups such as 4-methylbenzyl group, and groups in which part or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, chlorine, bromine, etc., for example, chloromethyl group, 2-bromoethyl group, 3 A chloropropyl group, 3,
Usually 1 carbon atom such as 3,3-trifluoropropyl group
And, preferably, a monovalent hydrocarbon group having 1 to 8 carbon atoms. Of these groups, methyl groups are most preferred because of their ease of synthesis, low viscosity before curing, and the degree of polymerization required to retain good physical properties after curing. .

R ⁵ is an alkenyl group, and examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group,
Isopropenyl group, 1-butenyl group, 2-butenyl group,
The one having usually 2 to 8 carbon atoms such as an isobutenyl group, a 1-hexenyl group and a cyclohexenyl group can be exemplified, but a vinyl group is preferred from the viewpoint of easy synthesis.
a, b and a + b are respectively 0 <a <3, 0 <b ≦ 1,
It is a positive number satisfying 1 <a + b ≦ 3, preferably 1.
8 ≦ a ≦ 2.2, 0.001 ≦ b ≦ 0.1, 1.8 <a
+ B <2.7.

The viscosity of the diorganopolysiloxane at 25 ° C. is required to give excellent physical properties after curing.
50-100,000 cp, especially 100-10000 cp
Is preferable. If the viscosity is too low, elongation and elasticity after curing become unsatisfactory, while if the viscosity is too high, workability in casting, potting, and other operations tends to decrease. When the adhesive silicone composition of the present invention is used after being cured at room temperature, the viscosity at 25 ° C. of the diorganopolysiloxane is 10,000
It is preferable to have a high viscosity of cp or more.

The organohydrogenpolysiloxane (b) serves as a cross-linking agent, and needs to have an average of three or more hydrogen atoms bonded to silicon atoms in one molecule, that is, SiH groups. There is. The hydrogen atom bonded to the silicon atom forms an elastic cured product by an addition reaction with the alkenyl group bonded to the silicon atom in the diorganopolysiloxane of the above component (a). It may be bonded to a silicon atom at the terminal of the molecular chain or bonded to a silicon atom in the middle of the molecular chain. Further, the molecular structure of the organohydrogenpolysiloxane may be any of a linear, cyclic, branched, and network three-dimensional structure, or a mixture thereof. As the organohydrogenpolysiloxane, a compound represented by the following general composition formula (3) is particularly preferably used.

R ⁶ _{c Hd} SiO _{(4-cd) / 2} (3)

In the formula, R ⁶ is a substituted or unsubstituted, preferably 1 to 10 carbon atoms excluding an aliphatic unsaturated bond, especially 1 to 8 carbon atoms.
And the same as the above-mentioned R ⁴ are exemplified. c, d and c + d are respectively 1 ≦ c ≦ 2.5,
0 <d ≦ 2, a positive number satisfying 1.5 ≦ c + d ≦ 3, preferably 1.5 ≦ c ≦ 2.2, 0.002 ≦ d ≦
1, 1.5 <c + d ≦ 3.

The viscosity of the organohydrogenpolysiloxane at 25 ° C. is in the range of 0.5 to 10,000 cp, preferably 5 to 500 cp, particularly 10 to 100 cp.
It is preferably in the range of p. If the viscosity is too low, it tends to volatilize due to its low boiling point, while if it is too high, synthesis becomes difficult.

The amount of the component (b) is such that the hydrogen atom (SiH) bonded to the silicon atom per equivalent of the alkenyl group bonded to the silicon atom in the diorganopolysiloxane (a).
Is preferably 0.5 to 10 equivalents, more preferably 1 to 5 equivalents, in molar ratio. If the amount is outside the above range, the resulting cured product (addition reaction product)
Has a low degree of cross-linking, and its physical properties deteriorate, foaming tends to occur during curing, or the physical properties of the cured product at high temperatures tend to change.

Next, the addition reaction catalyst of component (c) is used to promote the addition reaction (ie, curing) between the alkenyl group in component (a) and the silicon-bonded hydrogen atom in component (b). What is used. As such an addition reaction catalyst, those conventionally used in this type of addition reaction curable composition can be used, and examples thereof include platinum-based, palladium-based, and rhodium-based catalysts. For example, examples of platinum-based materials include chloroplatinic acid, complexes of platinum with olefins, ketones or vinyl siloxanes, those in which platinum is supported on a carrier such as alumina or silica, and platinum black. Examples of the palladium-based compound include tetrakis (triphenylphosphine) palladium and a mixture of palladium black and triphenylphosphine. Further, examples of the rhodium series include tetrakis (triphenylphosphine) rhodium, a mixture of rhodium black and triphenylphosphine, and the like. Of these, platinum-based ones are preferred.

The blending amount of the addition reaction catalyst is a catalytic amount,
Specifically, the total amount of the components (a) and (b) is set at 0.
It is desirable to use 1 to 1000 ppm, particularly 0.3 to 200 ppm. If the amount is less than the above range, poor curing tends to occur. If the amount is too large, no further effect can be obtained, and on the contrary, it may be economically disadvantageous.

The fluorine-containing organosilicon compound of the component (d) is
Acts as an adhesion promoter as described above,
A disilane compound represented by the following general formula (1) and having a perfluoroalkylene group or a perfluorooxyalkylene group and two amide groups in a molecule.

[0025]

Embedded image

In this equation, Rf Is a perfluoroalkylene
Group or a perfluorooxyalkylene group.
Those represented by the general formula are preferably used.

[0027] -C _p F _2p - (where, p is 1 to 50, preferably 2 to 20, especially 2 to
Indicates an integer of 10. )

[0028]

Embedded image q; 1, 2, 3, 4, 5, 6, 8, 10 or 12 r; 0, 1, 2, 3, 4, 5, or 6

[0029]

Embedded image v; 0, 1, 2, 3, 4 or 5 w; 0, 1, 2, 3, 4 or 5 x; 0 or 1

In each formula, X is independently a fluorine atom or a CF ₃ group, and s is 1 to 100, preferably 1 to 4
Integers of 0, t and u are each 0 to 50, preferably 1 to
Integer of 20, t + u is 1 to 100, preferably 2 to 40
Is an integer.

Note that s, t, and u are respectively 1,
2,3,4,5,6,7,8,9,10,11,12,
13, 14, or 15 are exemplified.

Specific examples of the divalent perfluoroalkylene group and perfluorooxyalkylene group include the following.

[0033]

Embedded image

Further, in the above formula (1), R ¹ is a divalent hydrocarbon radical or -R'NHR '- (R' is independently a divalent hydrocarbon group), the R ¹ or R ' The divalent hydrocarbon group has 1 to 12 carbon atoms, preferably 2 to 2 carbon atoms.
6, especially those having 2 to 4 carbon atoms are preferred. Specific examples of R ¹ include a methylene group, an ethylene group, a trimethylene group,
Tetramethylene group, methylethylene group, alkylene group such as hexamethylene group, phenylene group, biphenylene group,
Arylene groups such as a methyl phenylene group, -CH ₂ -C ₆ H
_{4 -, - CH 2 CH 2} CH 2 NHCH 2 CH 2 - and the like can be exemplified. Of these, a trimethylene group is most preferable because of ease of synthesis.

R ² is a substituted or unsubstituted monovalent hydrocarbon group, specifically, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, ter-butyl, pentyl, neopentyl Group, hexyl group, cyclohexyl group, octyl group, nonyl group, alkyl group such as decyl group, phenyl group, tolyl group, xylyl group, aryl group such as naphthyl group, vinyl group, allyl group, propenyl group, isopropenyl group, Butenyl group, isobutenyl group,
Hexenyl group, alkenyl group such as cyclohexenyl group,
Aralkyl groups such as benzyl group, phenylethyl group and phenylpropyl group, or chloromethyl group, bromoethyl group and chloropropyl group in which part or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, chlorine and bromine; Examples thereof include those having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms excluding an aliphatic unsaturated bond, such as a group and a 3,3,3-trifluoropropyl group. R ³
Is an alkyl group or an alkoxyalkyl group, specifically, the alkyl group includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group,
-Having 1 to 1 carbon atoms such as butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, and octyl group;
8 and particularly those having 1 to 4 carbon atoms. Examples of the alkoxyalkyl group include those having 2 to 4 carbon atoms such as a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group and an ethoxyethyl group. Can be mentioned.

In the above formula, n is 0, 1, 2, or 3,
It is preferably 0 or 1 from the viewpoint of imparting adhesiveness,
The component (d) preferably has at least three, especially four or more R ³ O groups in the molecule.

The amount of the component (d) is as follows:
0.1 to 10 parts by weight, especially 0.5 to 100 parts by weight
The amount is preferably 2 parts by weight. If the amount of the component (d) is too small, the effect of improving the adhesion may be poor. On the other hand, if the amount is too large, the strength of the rubber cured product may be reduced or the economical disadvantage may be caused. It may be.

In the adhesive composition of the present invention, various additives can be used in addition to the above-mentioned components (a) to (d) as long as the adhesiveness is not impaired. For example, fumed silica, precipitated silica, quartz powder, diatomaceous earth, titanium oxide, aluminum oxide, zinc oxide, iron oxide, mica, clay, carbon black, graphite, glass beads, metal powder, filler such as calcium carbonate, water Heat and flame retardant imparting agents such as cerium oxide, pigments, adhesion aids, fungicides, organic solvents such as toluene and hexane, and viscosity modifiers composed of diorganopolysiloxanes of a type different from component (a) And the like can be used in an appropriate amount as needed.

The adhesive silicone composition of the present invention can be obtained by mixing the above-mentioned components. In this case, there is no particular limitation on the order of mixing the components.

The adhesive silicone composition of the present invention can be used in the same manner as ordinary adhesives, and can be used, for example, by casting, potting, coating, impregnating, or the like. In addition, there is no restriction on the target adherend,
In particular, it can be suitably used for plastics, for example, epoxy resin, polycarbonate, polybutylene terephthalate, and the like.

In use, for example, 120 to 150
The composition can be cured at a temperature of 10 ° C. for 10 to 30 minutes.

[0042]

The adhesive silicone composition of the present invention, in which the adhesion promoter of the formula (1) is blended, has properties in addition to the inherent heat resistance, weather resistance, electrical properties, stress relaxation properties, etc. of silicone. , Especially excellent adhesion to plastics.

[0043]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition, in the following examples, a part shows a weight part and a viscosity shows the measured value in 25 degreeC.

Examples 1 to 6, Comparative Examples (a) Dimethylpolysiloxane having a molecular chain end blocked with a dimethylvinylsilyl group and having a viscosity of 10,000 cp:
100 parts, (b) methyl hydrogen polysiloxane having a viscosity of 30 cp and having an average molecular formula represented by the following formula:
4.0 parts, (the molar ratio of SiH groups to vinyl groups in the component (a) is about 1.2 mol / mol) (c) Isopropyl alcohol solution of chloroplatinic acid (platinum content 2% by weight): 0.06 Part, (d) adhesion promoter (1) shown below
To (6): 1.0 part and hydrophobic silica (BET specific surface area: 170 m ² / g): 27 parts were uniformly mixed to prepare six kinds of adhesive silicone compositions. For comparison,
It was prepared without using the following adhesion promoter.

[0045]

Embedded image

[0046]

Embedded image (However, Me: CH ₃ , Et: C ₂ H ₅ )

These adhesive compositions were prepared using epoxy resin (Nippon Test Panel), polycarbonate (PC) (Nippon Test Panel), polybutylene terephthalate (PBT) (Nippon Test Panel), glass (Nippon Test Panel). (Manufactured by Panel Co., Ltd.), and cured by heating at 120 ° C. for 30 minutes.
gf / cm ² ) was measured in accordance with JIS-K-6850. Table 1 shows the results.

[0048]

[Table 1]

From the results shown in Table 1, it is confirmed that the adhesive silicone composition of the present invention shows good adhesiveness to various plastics.

──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Koji Matsuda 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture 10 Shin-Etsu Chemical Co., Ltd.Silicon Electronics Materials Technology Laboratory (58) Field surveyed (Int. Cl ^7, DB name) C09J 1/00 -. 201/10 C08L 1/00 - 101/16

Claims (1)

(57) [Claims] 1. A diorganopolysiloxane containing an average of two or more alkenyl groups bonded to a silicon atom in one molecule;
(C) addition reaction catalyst (d) fluorinated organosilicon compound represented by the following general formula (1) Wherein R _f is a perfluoroalkylene group or a perfluorooxyalkylene group, R ¹ is an alkylene group having 1 to 12 carbon atoms, an arylene group or —CH ₂ —C ₆ H ₄
— Or —R′NHR ′ — (R ′ is each independently C ₂ H
₄ or C ₃ H ₆ is shown. ), R ² is an alkyl group having 1 to 10 carbon atoms, an aryl group, an alkenyl group, an aralkyl group, or a group in which part or all of the hydrogen atoms of these groups are substituted with halogen atoms, and R ³ is an alkyl group or an alkoxy group. The alkyl group and n show the integer of 0-3. ] An adhesive silicone composition comprising: