JPH0657231A - Adhesive composition - Google Patents

Abstract

PURPOSE:To provide an adhesive composition which is tacky in the initial stage, is curable under anaerobic conditions and can develop adhesiveness when cured. CONSTITUTION:The adhesive composition comprises an organopoly-siloxane copolymer essentially consisting of repeating units of (R<1>)3SiO1/2 (wherein R<1> is a monovalent hydrocarbon group) and SiO2 repeating units, an organopolysiloxane of a degree of polymerization of 3000 or above, represented by the average compositional formula: (R<1>)aSiO(4-a)/2 (wherein R<1> is as defined above; and a is a number of 1.95-2.05), carbon black and an organic peroxide of the formula [wherein R<2> is a monovalent hydrocarbon group or -Si(R<4>)3 (wherein R<4> is an alkyl or aryl), and R<3> is a bivalent group represented by -(R'O)m-R''- (wherein R' and R'' are each a bivalent hydrocarbon group; and m is an integer of 1-4)].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition useful as a waterproof sealing material for construction, an adhesive, etc.

[0002]

2. Description of the Related Art In recent years, a method of using a silicone rubber molding by adhering it to a predetermined base has been widely adopted. That is, compared to synthetic rubber-based building gaskets, silicone gasket materials not only have excellent weather resistance and flame retardancy, but also have a small compression set and are waterproof for buildings that require long-term reliability. It has excellent properties as a seal. Therefore, the demand for silicone gasket materials as a waterproof seal is rapidly increasing in the construction industry. For example, these silicone gasket materials are used as waterproof sealing materials by adhering to metal curtain walls, concrete curtain walls, aluminum sashes, ALC panels, etc. used as outer walls of buildings. Further, in order to adhere the silicone gasket to the outer wall, a silicone sealant is used as an adhesive.

[0003]

However, the silicone sealant is a moisture-curable type adhesive composition, and its curing takes a considerable amount of time. For example,
After adhering the silicone gasket to the outer wall with the silicone sealant, at least one day has passed,
Silicone gasket does not adhere to the outer wall firmly. For this reason, the outer wall panel cannot be moved immediately, resulting in extremely low productivity in the factory. Therefore, it is an object of the present invention to provide an adhesive composition that is initially tacky, can be cured under anaerobic conditions, and exhibits adhesive strength during curing.

[0004]

According to the present invention, (A) formula: (R ¹ ) ₃ SiO _1/2 (wherein R ¹ may be the same or different and may be substituted or unsubstituted). A unit represented by a monovalent hydrocarbon group (hereinafter referred to as M) and SiO ₂
It is essentially composed of units (hereinafter referred to as Q),
An organopolysiloxane copolymer in which the molar ratio of M and Q, M / Q is in the range of 0.6 to 0.9,

(B) The following average composition formula (1): (R ¹ ) _a SiO _{(4-a) / 2} (1) (wherein R ¹ is as described above, and a is a number from 1.95 to 2.05). The total R ¹ in one molecule is 0.0001 ~
0.5 mol% is an alkenyl group, and an organopolysiloxane having a degree of polymerization of 3000 or more,

(C) carbon black, and

(D) The following formula (2):

[0008]

[Chemical 2]

(In the formula, R ^{2 s} may be the same or different and may be a monovalent hydrocarbon group having 3 to 10 carbon atoms or --Si (R
⁴ ) ₃ (wherein R ^4's may be the same or different and each is a rualkyl group or an aryl group), and R ³
Is a divalent hydrogen group having 1 to 8 carbon atoms, or a formula:
-(R'O) _m -R "-(wherein R'and R" may be the same or different and are a divalent hydrocarbon group having 1 to 8 carbon atoms, and m is 1 to 4). Is a divalent group represented by. The adhesive composition containing the organic peroxide represented by these is provided. Hereinafter, each component will be described.

Component (A) In the present invention, the organopolysiloxane copolymer used as the component (A) is essentially composed of M units and Q units as described above. Here, R ¹ in M is, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a vinyl group, an allyl group, a propenyl group, an alkenyl group such as a butenyl group, an aryl group such as a phenyl group and a tolyl group, And groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms, cyano groups, etc., such as chloromethyl group, chloropropyl group, 3,3,3-trifluoropropyl group, 2-cyanoethyl group, etc. Mention may be made of substituted or unsubstituted monovalent hydrocarbon radicals.

In this organopolysiloxane copolymer, it is important that the molar ratio M / Q of M and Q is in the range of 0.6 to 0.9. If the amount of M is more than the above range, the initial tackiness may be insufficient, and if the amount of M is less than the range, the component (A) may be stabilized. There are inconveniences such as difficulty in manufacturing.

The above-mentioned organopolysiloxane copolymer is a unit other than M and Q, such as R ¹ as long as it does not impair the property of the composition of the present invention that it exhibits high tackiness in the early stage of curing. It may be a unit such as SiO _3/2 , (R ¹ ) ₂ SiO _2/2 (R ¹ is as described above). The above-mentioned organopolysiloxane copolymer can be produced by a method known per se. For example, (R ¹ ) ₃ SiCl (where R ¹ is as described above) and SiCl ₄ are blended so that the molar ratio of M and Q is within the above-mentioned range, and co-hydrolysis condensation is performed. It is easily synthesized by carrying out.

Component (B) The alkenyl group-containing organopolysiloxane used as component (B) is represented by the above average composition formula (1), and R ¹ in the formula (1) is The same as those exemplified in the item of the component (A) can be mentioned. Further, the content of alkenyl groups in this organopolysiloxane is 0.0001 to 0 out of all R ¹ in one molecule.
The range is 5 mol%. By setting the content of the alkenyl group in this range, it is possible to impart good anaerobic curability to the obtained adhesive composition.

The molecular structure of this alkenyl group-containing organopolysiloxane is preferably linear.
The molecule may have a branched structure. The terminal of this molecule may be blocked with a triorganosilyl group or a hydroxyl group. Examples of the triorganosilyl group include a trimethylsilyl group, a dimethylvinyl group, a methylphenylvinylsilyl group, a dimethylphenylsilyl group, a methyldivinylsilyl group and a trivinylsilyl group.

Further, the degree of polymerization of the alkenyl group-containing organopolysiloxane is 3000 or more, preferably 5
It is 000 to 10000. Use of a polymer having a too low degree of polymerization causes problems such as insufficient initial tackiness of the composition of the present invention. In the present invention, the organopolysiloxane copolymer of the component (A) and the alkenyl group-containing organopolysiloxane of the component (B) described above are (A)
It is preferably used in a ratio of / (B) = 30/70 to 70/30, and more preferably (A) / (B) = 40/60 to 60/40. If this (A) / (B) ratio is too large or too small, problems such as insufficient initial tackiness occur.

Component (C) In the present invention, the carbon black used as the component (C) is mainly used as a catalyst for promoting curing under anaerobic conditions.

As such carbon black, usually,
Those commonly used in silicone rubber compositions can be used, and these include acetylene black, conductive furnace black (CF), super conductive furnace black (SCF), extra conductive furnace black (XCF), Conductive channel black (CC), and furnace black and channel black heat-treated at a high temperature of about 1500 ° C. Specifically, as acetylene black, electrified acetylene black (manufactured by Denki Kagaku), Shawnigan acetylene black (manufactured by Shawnigan Chemical Co., Ltd.), and as conductive furnace black, Continex CF (manufactured by Continental Carbon Co. ), Vulcan C (manufactured by Cabot Co., Ltd.), etc., as Super Conductive Furnace Black, Continex SCF (manufactured by Continental Carbon Co., Ltd.), Vulcan SC (manufactured by Cabot Co., Ltd.), etc., Asahi HS-500 (Made by Asahi Carbon Co., Ltd.), Vulcan XC-72 (Made by Cabot)
As the conductive channel black, commercially available products such as COULAX L (manufactured by Degussa) can be used. Further, commercially available products such as Ketjen Black EC and Ketjen Black EC-600JD (manufactured by Ketjen Black International), which are types of furnace black, can also be used. In the present invention, particularly suitable carbon blacks are furnace black, Ketjen black, channel black and acetylene black.

In the present invention, the carbon black is used in an amount of 0.1 to 20 parts by weight, particularly 1 to 10 parts by weight, per 100 parts by weight of the total amount of the components (A) and (B). Is preferred. Furthermore, for the purpose of conductivity,
When carbon black is added, the amount of carbon black may be increased beyond the above range.

Component (D) In the present invention, the general formula (2) used as the component (D)
The organic peroxide represented by is an essential catalyst for the composition to cure under anaerobic conditions. In the general formula (2), R ² is a monovalent hydrocarbon group having 3 to 10 carbon atoms or —Si (R ⁴ ) ₃ (R ⁴ is as described above), and is, for example, n-propyl. Group, isopro group, t-butyl group, n-amyl group, t-amyl group, hexyl group, heptyl group, octyl group, 2-ethylpropyl group, 2-ethylbutyl group, 2
An alkyl group such as an ethylhexyl group and a cumyl group, and
Examples thereof include triorganosilyl groups such as trimethylsilyl group, triethylsilyl group and triphenylsilyl group.

In the general formula (2), R ³ is
A divalent hydrocarbon group having 1 to 8 carbon atoms or a formula:-(R '
O) _m -R "-(wherein R'and R" may be the same or different and are a divalent hydrocarbon group having 1 to 8 carbon atoms, and m is an integer of 1 to 4). Is a divalent group represented by.

Examples of the divalent hydrocarbon group having 1 to 8 carbon atoms include methylene group, ethylene group, propylene group,
Linear divalent hydrocarbon groups such as butylene group, pentylene group, hexylene group, heptylene group, octylene group; dimethylmethylene group, isopropylene group, 2-methylpropylene group, 2,2-dimethylpropylene group, etc. Examples thereof include a branched chain divalent hydrocarbon group.

On the other hand, examples of R'and R "include the same ones as the divalent hydrocarbon group having 8 to 8 carbon atoms exemplified for R ³ above. Formula:-(R'O) _m −R ”−
Specific examples of the divalent group represented by: 3-oxapentylene group, 3,6-dioxaoctylene group, 3,6,9
- trio key sound decylene group, 3,6,9,12 formula :-( CH ₂ CH ₂ O, such tetraoxatetracosane decylene group) _m -CH
_A divalent group represented by ₂ CH ₂ — (wherein it is an integer of m to 4) can be mentioned. In the present invention, the most preferably used organic peroxide is represented by the formula (3), (4) and
(Five):

[0023]

[Chemical 3]

[0024]

[Chemical 4]

[0025]

[Chemical 5]

Examples of compounds represented by: The organic peroxide of the component (D) is 0.1 to 5 parts by weight, particularly 0.5 to 3 parts by weight per 100 parts by weight of the total amount of the components (A) and (B).
It is preferably used in the range of parts by weight. If it is less than 0.1 part by weight, the effect as a catalyst is not sufficient, and curing may be insufficient. Further, even if it is used in an amount of more than 5 parts by weight, there is no further effect, and not only the cost is increased, but also the adverse effect of the decomposition residue may occur.

Other compounding agents In the adhesive composition of the present invention, various additives may be added, if necessary, in addition to the components (A) to (D) described above, as long as the adhesiveness is not impaired. It can be blended.
For example, a filler can be added for the purpose of reinforcement or weight increase. As the filler, those known per se can be used, for example, fine powder silica, fumed silica, precipitated silica, diatomaceous earth, iron oxide, zinc oxide, metal oxides such as titanium oxide, and these. Whose surface is hydrophobized with silane, metal carbonate such as calcium carbonate, magnesium carbonate, zinc carbonate, asbestos,
Glass fibers, finely powdered mica, fused silica powder and the like can be added.

In addition to the above-mentioned fillers, for example, thixotropy-imparting agents such as polyethylene glycol or its derivatives, pigments, dyes, antioxidants, antioxidants, antistatic agents, antimony oxide, paraffin chloride, etc. Thermal conductivity improvers such as flame retardants, boron nitride and aluminum oxide, organosilicon compounds having reactive organic groups such as amino groups, epoxy groups and mercapto groups, adhesion promoters such as silane coupling agents, plasticizers, and sauces. Inhibitors, antifouling agents, antiseptics, bactericides, antifungal agents and the like may be added.

Adhesive Composition The adhesive composition of the present invention is easily prepared by uniformly mixing the above-mentioned components. Since this composition easily cures at room temperature even under anaerobic conditions, for example,
This is applied to a predetermined base material such as a wall material, and a silicone gasket material or the like is pressure-bonded on the base material to cure it, and the silicone gasket material is bonded onto the base material. When the adhesive composition is applied to a substrate, it can be diluted with an appropriate solvent, for example, a hydrocarbon solvent such as toluene, xylene, petroleum ether, a solvent such as ketones, esters, etc. .

[0030]

The present invention will be described in the following examples. In the following examples, as the organopolysiloxane copolymer of the component (A), the following solvent-soluble silicone resins (a-1) and (a
−2) was used. Solvent-soluble silicone resin (a-1); consisting of Me ₃ SiO _1/2 unit (M) and SiO ₂ unit (Q), molar ratio of M and Q (Q) is 0.75, viscosity at 25 ° C Is 850 cP and is a toluene solution with a nonvolatile content of 70.5%. Solvent-soluble silicone resin (a-2); composed of ViMe ₂ SiO _1/2 units (M) and SiO ₂ units (Q), molar ratio of M and Q / Q) is 0.75, viscosity at 25 ° C Is 850 cP and is a toluene solution with a nonvolatile content of 69.5%. In the above unit formula, Me is a methyl group and Vi is a vinyl group.

Example 1 and Comparative Examples 1 and 2, composed of 98.975 mol% of dimethylsiloxane units and 1.0 mol% of methylvinylsiloxane units, and the viscosity of which was blocked with 0.025 mol% of dimethylvinylsilyl groups at the molecular end was 10,00.
50 parts by weight of toluene was added to 100 parts by weight of organopolysiloxane having a composition of 0,000 cSt (25 ° C.) and dissolved. Next, 150 parts by weight of solvent-soluble silicone resin (a-1) was added to this solution and heated at 150 ° C for 2 hours to obtain a viscosity of 3000 cSt.
(25 ° C.), and a liquid composition (a) having a nonvolatile content of 68.7% was obtained.

To 100 parts by weight of this liquid composition (a), 2 parts by weight of acetylene black (manufactured by Denki Kagaku Co., Ltd.) was added and uniformly mixed with a three-roll mill. An adhesive composition was prepared by adding 1 part by weight of glycidoxypropyltrimethoxysilane and 1 part by weight of the peroxide of the formula (3) to this mixture (Example 1). For comparison, an adhesive composition was prepared in the same manner as above except that the peroxide of formula (3) was not used (Comparative Example 1).

These adhesive compositions were applied on an aluminum panel to a thickness of 0.5 mm, left at room temperature for 15 minutes, and then molded and vulcanized to a thickness of 2 mm to obtain a vulcanized silicone rubber sheet at about 1 kgf /. A test piece was prepared by pressure bonding with a pressure of cm ² . With respect to this test piece, the adhesive force between the aluminum panel and the silicone rubber sheet was measured with time. The results are shown in Table 1.
Shown in. Also, silicone sealant 45 for comparison
The results when using (manufactured by Shin-Etsu Chemical Co., Ltd.) are also shown (Comparative Example 2).

[0034]

[Table 1]

Example 2 and Comparative Example 3 As in Example 1, except that the solvent-soluble silicone resin (a-1) was used in place of the solvent-soluble silicone resin (a-1). Similarly, the viscosity is 3000cSt (25 ℃)
Thus, a liquid composition (ii) having a nonvolatile content of 68.7% was obtained. Using this liquid composition (b), an adhesive composition was prepared in the same manner as in Example 1 (Example 2), and the same test piece was prepared, and the change in adhesive strength with time was measured. Further, an adhesive composition was prepared in the same manner as above (Comparative Example 3) except that the peroxide of the formula (3) was not used, and test pieces were prepared in the same manner, and the change with time of the adhesive strength was measured. . The results are shown in Table 2.

[0036]

[Table 2]

Example 3 To 100 parts by weight of the liquid composition (a) used in Example 1, 2 parts by weight of acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd.) was added and uniformly mixed with a three-roll mill. To this mixture were added: 1 part by weight of glycidoxypropyltrimethoxysilane 1 part by weight of peroxide of formula (5) to prepare an adhesive composition. Using this adhesive composition, a test piece was prepared in the same manner as in Example 1, and the change in adhesive strength with time was measured. The measurement results are shown in Table 3.

[0038]

[Table 3]

[0039]

The adhesive composition of the present invention can be rapidly cured under anaerobic conditions, exhibits excellent tackiness in the early stage of curing, and exhibits adhesive strength with curing. Therefore, this composition is extremely useful, for example, in the field of construction when it is used as a silicone sealant used for adhering a silicone gasket for a waterproof seal, because the workability and the adhesiveness obtained are good. Further, since the workability is good, the productivity of, for example, a waterproof sealed wall material is significantly improved.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumiyoshi Tsuchida 1 Hitomi, Oita, Matsuida-cho, Usui-gun, Gunma 10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory

Claims (1)

[Claims] 1. A formula (A): (R ¹ ) ₃ SiO _1/2 (wherein R ¹
Are each a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different. ) Units (
Hereinafter referred to as M. ) And a SiO ₂ unit (hereinafter referred to as “Q”), the molar ratio of M to Q, M /
An organopolysiloxane copolymer in which Q is in the range of 0.6 to 0.9, (B) average composition formula (1): (R ¹ ) _a SiO _{(4-a) / 2} (1) (wherein R ¹ is the above And a is a number from 1.95 to 2.05), and 0.0001 of all R ¹ in one molecule.
~ 0.5 mol% is an alkenyl group and has a degree of polymerization of 3000 or more, an organopolysiloxane, (C) carbon black, and (D) formula (2): (In the formula, R ² may be the same or different, a monovalent hydrocarbon group having 3 to 10 carbon atoms or —Si (R ⁴ ) ₃ (wherein, R ⁴ may be the same or different. It is also an alkyl group or an aryl group.) And R ³ is
A divalent hydrocarbon group having 1 to 8 carbon atoms, or a formula:-
(R′O) _m —R ″ — (wherein R ′ and R ″ may be the same or different and are a divalent hydrocarbon group having 1 to 8 carbon atoms, and m is 1 to 4). Is a divalent group represented by. ) An adhesive composition containing an organic peroxide represented by: