JP2787128B2 - Adhesive 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 composition useful as a waterproof sealing material for construction, an adhesive and the like.

[0002]

2. Description of the Related Art In recent years, a method of using a silicone rubber molded article adhered to a predetermined substrate has been widely adopted. That is, the silicone gasket material has not only excellent properties such as weather resistance and flame retardancy, but also a small compression set, as compared with a synthetic rubber-based building gasket, and is a waterproof material for buildings requiring long-term reliability. It has excellent properties as a seal. For this reason, the demand in the construction industry for a silicone gasket material as a waterproof seal is rapidly increasing. For example, these silicone gasket materials are used as waterproof sealing materials by bonding to metal curtain walls, concrete curtain walls, aluminum sashes, ALC panels and the like used as exterior walls of buildings. 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 of adhesive composition, and its curing requires a considerable amount of time. For example,
After attaching the silicone gasket to the outer wall using the silicone sealant, wait at least one day before
The silicone gasket does not adhere firmly to the outer wall. For this reason, the outer wall panel cannot be moved immediately, and the productivity in the factory has been extremely low. Accordingly, an object of the present invention is to provide an adhesive composition which is initially tacky, can be cured under anaerobic conditions, and exhibits adhesive strength upon 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 an alkyl group, an alkenyl group,
An aryl group, or a halogen atom-substituted product thereof, or
It is a cyano group-substituted product . ) And an SiO ₂ unit (hereinafter referred to as Q), and the molar ratio of M to Q, M / Q is 0.6 to
An organopolysiloxane copolymer in the range of 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 of 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 polymerization degree of 3000 or more,

(C) carbon black, and

(D) The following equation (2):

[0008]

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(Wherein, R ² may be the same or different and is an alkyl group having 3 to 10 carbon atoms or —Si
(R ⁴ ) ₃ (where R ⁴ may be the same or different and is an alkyl group or an aryl group.)
R ³ is a linear or branched having 1 to 8 carbon atoms.
A chain alkylene group or a formula:-(R'O) _m -R "
— (Where R ′ and R ″ may be the same or different and are the same groups as R ^3, and m is an integer of 1 to 4). An adhesive composition containing an organic peroxide represented by the following formula (1) is provided.

[0010] In the component (A) present invention, the organopolysiloxane copolymer used as component (A), as described above, it is made M and Q units Toka et structure. Wherein R ¹ in M is ethyl group, an alkyl group such as propyl, vinyl group,
Allyl group, propenyl group, alkenyl group such as butenyl group, phenyl group, aryl group such as tolyl group, and a group in which part or all of the hydrogen atoms of these groups are substituted with a halogen atom or a cyano group, For example, chloromethyl, chloropropyl, 3,3,3-trifluoropropyl, 2-
It is a cyanoethyl group, and the like.

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. When M is present more than the above range, there are disadvantages such as insufficient initial tackiness, and when the amount of M is smaller than the above range, the component (A) can be stably prepared. There are inconveniences such as difficulty in manufacturing.

The above-mentioned organopolysiloxane copolymer has a unit other than M and Q, for example, 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. Units such as SiO _3/2 and (R ¹ ) ₂ SiO _2/2 (R ¹ is as described above) may be used. 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 to Q is within the range described above, and co-hydrolytic condensation is performed. It is easily synthesized by performing.

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

The molecular structure of the alkenyl group-containing organopolysiloxane is preferably a linear one.
The molecule may have a branched structure. Further, this molecular terminal 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 3,000 or more, preferably 5 to 5.
000 to 10,000. If the degree of polymerization is too small, problems such as insufficient initial tackiness of the composition of the present invention occur. In the present invention, the organopolysiloxane copolymer of the component (A) and the alkenyl group-containing organopolysiloxane of the component (B) are (A)
/ (B) = 30/70 to 70/30, preferably (A) / (B) = 40/60 to 60/40. If the ratio (A) / (B) is too large or too small, problems such as insufficient initial tackiness occur.

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

As such carbon black, usually,
Those commonly used in silicone rubber compositions can be used. These include acetylene black, conductive furnace black (CF), superconductive furnace black (SCF), extra conductive furnace black (XCF), There are conductive channel black (CC), furnace black and channel black heat-treated at a high temperature of about 1500 ° C. Specifically, acetylene black includes electrified acetylene black (manufactured by Denki Kagaku), Shaunigan acetylene black (manufactured by Shaunigan Chemical), and conductive furnace black includes Continex CF (manufactured by Continental Carbon). ), Vulcan C (manufactured by Cabot), Superconducting furnace black such as Continex SCF (manufactured by Continental Carbon), Vulcan SC (manufactured by Cabot), etc. As an extra-conductive furnace black, Asahi HS-500 (Asahi Carbon), Vulcan XC-72 (Cabot)
As the conductive channel black, commercially available products such as Colux L (manufactured by Degussa) can be used. Commercial products such as Ketjen Black EC and Ketjen Black EC-600JD (Ketjen Black International), which are a kind of furnace black, can also be used. In the present invention, particularly preferred 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, especially 1 to 10 parts by weight, per 100 parts by weight of the total 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 organic peroxide represented by the general formula (2) used as the component (D) is an essential catalyst for the composition to cure under anaerobic conditions. . The general formula (2)
In the formula, R ² is an alkyl group having 3 to 10 carbon atoms or —Si (R ⁴ ) ₃ (R ⁴ is as defined above).
Ri, for example, n- propyl group, isopropyl group, t- butyl group, n- amyl group, t-amyl group, a hexyl group, heptyl group, octyl group, 2-ethylpropyl group, 2-ethylbutyl group, 2-ethylhexyl group And trialkylsilyl groups such as trimethylsilyl group, triethylsilyl group and triphenylsilyl group.

In the general formula (2), R
³ is a linear or branched alkyl having 1 to 8 carbon atoms.
Killen group or the formula :-( _R'O) m -R "- by (wherein, R 'and R" may be the same or different, ^{R 3}
When likewise linear or branched A 1 to 8 carbon atoms
M is an integer of 1 to 4. ) Is a divalent group.

Examples of the linear alkylene group having 1 to 8 carbon atoms, e.g., methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group etc., also branched Alkylene
As the group, a dimethylmethylene group, an isopropylene group,
2-methyl propylene, 2,2-dimethylpropylene, and the like.

On the other hand, R ′ and R ″ are, for example,
The same as the above-mentioned divalent hydrocarbon groups having 1 to 8 carbon atoms for R ³ can be used. Formula:-(R '
O) Specific examples of the divalent group represented by _m- R "-include:
3-oxapentylene group, 3,6-dioxaoctylene group, 3,6,9-trioxaundecylene group, 3,6
Formula such as 9,12-tetraoxatetradecylene group:
(CH ₂ CH ₂ O) _m —CH ₂ CH ₂ — (where m is
It is an integer of 1 to 4. )). In the present invention, organic peroxides most preferably used include those represented by formulas (3), (4) and (5):

[0023]

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[0024]

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[0025]

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Compounds represented by the following formulas are exemplified. The organic peroxide of the component (D) is used in an amount of 0.1 to 5 parts by weight, particularly 0.5 to 3 parts by weight, per 100 parts by weight of the total of the components (A) and (B).
It is preferred that it be used in the range of parts by weight. If the amount is less than 0.1 part by weight, the effect as a catalyst is not sufficient, and the 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 other than the above-mentioned components (A) to (D) may be added, if necessary, as long as the adhesiveness is not impaired. Can be blended.
For example, a filler can be blended for the purpose of reinforcing or increasing the amount. 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 the like. Surface of which has been hydrophobized with silane, etc., metal carbonates such as calcium carbonate, magnesium carbonate, zinc carbonate, asbestos,
Glass fiber, fine powder mica, fused silica powder and the like can be blended.

In addition to the above-mentioned fillers, for example, thixotropy-imparting agents such as polyethylene glycol or derivatives thereof, pigments, dyes, antioxidants, antioxidants, antistatic agents, antimony oxide, paraffin chloride, etc. Flame retardants, thermal conductivity improvers such as boron nitride, aluminum oxide, etc .; organosilicon compounds having reactive organic groups such as amino groups, epoxy groups and mercapto groups; adhesives such as silane coupling agents; plasticizers; An inhibitor, an antifouling agent, a preservative, a bactericide, a fungicide, and the like can also be added.

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

[0030]

The present invention will be described with reference to 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 units (M) and SiO ₂ units (Q), the molar ratio (Q) between M and Q is 0.75, and the viscosity at 25 ° C. Is 850 cP and a toluene solution with a nonvolatile content of 70.5%. Solvent-soluble silicone resin (a-2); consisting of ViMe ₂ 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 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, Comparative Example 1, 2, 98.975% by mole of dimethylsiloxane unit and 1.0% by mole of methylvinylsiloxane unit, having a molecular end of 0.000% by mole blocked with 0.025% by mole of dimethylvinylsilyl group.
50 parts by weight of toluene was added to and dissolved in 100 parts by weight of an organopolysiloxane of 000 cSt (25 ° C.). Next, 150 parts by weight of the solvent-soluble silicone resin (a-1) was added to this solution, and the mixture was heated at 150 ° C. for 2 hours to have a viscosity of 3000 cSt.
(25 ° C.) and a liquid composition (A) having a nonvolatile content of 68.7%.

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

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

[0034]

[Table 1]

Example 2 and Comparative Example 3 Example 1 was repeated except that the solvent-soluble silicone resin (a-2) was used in place of the solvent-soluble silicone resin (a-1). Similarly, the viscosity is 3000cSt (25 ℃)
Thus, a liquid composition (b) 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 a similar test piece was prepared. An adhesive composition was prepared in the same manner as described above except that the peroxide of the formula (3) was not used (Comparative Example 3), and a test piece was prepared in the same manner, and a change with time of the adhesive force was measured. . Table 2 shows the results.

[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 KK) was added, and the mixture was uniformly mixed with a three-roll mill. To this mixture was added 1 part by weight of glycidoxypropyltrimethoxysilane. 1 part by weight of a peroxide of the 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 over time in the adhesive strength was measured. Table 3 shows the measurement results.

[0038]

[Table 3]

[0039]

The adhesive composition of the present invention can be quickly cured under anaerobic conditions, exhibits excellent tackiness in the early stage of curing, and exhibits adhesive strength together with curing. Accordingly, this composition is extremely useful when used as a silicone sealant for bonding a silicone gasket for waterproof sealing, for example, in the field of construction, since both the workability and the obtained adhesiveness are good. In addition, since the workability is good, for example, the productivity of a waterproof and sealed wall material is significantly improved.

Continued on the front page (72) Inventor Tomiyoshi Tsuchida 1-10 Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture Inside the Silicone Electronics Materials Research Laboratory, Shin-Etsu Chemical Co., Ltd. (56) References JP-A-5-65414 (JP, A JP-A-59-45356 (JP, A) JP-B-35-18190 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09J 183/04 C09J 183/07

Claims (1)

(57) [Claims] 1. Formula (A): (R ¹ ) ₃ SiO _1/2 (wherein R ¹ may be the same or different,
An alkyl group, an alkenyl group or an aryl group, or
These are halogen-substituted or cyano-substituted products . )) (Hereinafter referred to as M) and SiO
₂ units (hereinafter, Q referred.) Toka made et configured, the molar ratio of M and Q, organopolysiloxane copolymers M / Q is in the range of 0.6 to 0.9, (B) the average compositional formula (1): (R ¹ ) _a SiO _{(4. a) / 2} (1) (wherein R ¹ is as described above, and a is 1.95 to 2.
05 is the number. ), And all R ¹ in one molecule
Is an alkenyl group,
An organopolysiloxane having a degree of polymerization of 3000 or more, (C) carbon black, and (D) a formula (2): (Wherein, R ² may be the same or different, and an alkyl group having 3 to 10 carbon atoms or —Si (R ⁴ ) ₃ (where R ⁴ may be the same or different,
It is an alkyl group or an aryl group. ) And R
³ is a linear or branched alkyl having 1 to 8 carbon atoms.
A ren group or a formula: — (R′O) _m —R ″ — (where R ′ and R ″ may be the same or different ;
^It is the same group as ^3, and m is an integer of 1-4. ) Is a divalent group. An adhesive composition comprising the organic peroxide represented by the formula (1).