JP3344012B2 - Moisture curable organopolysiloxane composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-curable organopolysiloxane composition which cures at room temperature, and more particularly to a moisture-curing composition which cures at room temperature and has excellent storage stability and adherence to an adherend. The present invention relates to a water-soluble organopolysiloxane composition.

[0002]

2. Description of the Related Art Silicone is a substance having high industrial utility such as impact resistance, vibration resistance and heat stress resistance, utilizing a flexible cured product and its elasticity.

Conventionally, various types of room-temperature-curable organopolysiloxane compositions which become elastomeric at room temperature upon contact with moisture in the air are known in the art. It is characterized by not having an unpleasant odor and not corroding metals, and is preferably used for sealing, bonding and coating of electric and electronic equipment.

[0004]

As a typical example of this type, Japanese Patent Application Laid-Open No. 55-43119 discloses a composition comprising an alkoxysilyl-terminal-blocked organopolysiloxane, an alkoxysilane and an alkoxytitanium. However, this composition has problems in storage stability and adhesion under sealed conditions.

Japanese Patent Application Laid-Open No. 61-247756 discloses a composition comprising an alkoxysilyl-terminal-blocked organopolysiloxane, an alkoxysilane, surface-treated silica, and a titanium chelate catalyst. There is a problem with the adhesion to the kimono.

The present invention provides a moisture-curable organopolysiloxane composition which overcomes the above-mentioned drawbacks, has excellent storage stability under sealed conditions, and has excellent adhesion to an adherend and can be cured at room temperature. The purpose is to do.

[0007]

[MEANS FOR SOLVING THE PROBLEMS] The present invention provides the above-mentioned problems.
As a result of intensive research to solve the point, organopolysilo
Xane and alkoxylan or its partially hydrolyzed condensate
Storage stability and adhesion by combination with moisture curing catalyst
Moisture-curable Olga that cures at room temperature with excellent adhesion to the body
Nopolysiloxane composition found to be obtained
It is.

The organopolysiloxane used in the present invention has a viscosity in the range of 20 mPa · s to 1000 Pa · s at 25 ° C. If the viscosity is less than 20 mPa · s, the cured elastomer has excellent physical properties, especially softness. This is because the composition cannot give high elongation and high elongation, and if it is more than 1000 Pa · s, the viscosity of the composition becomes high and the workability at the time of construction becomes extremely poor. Therefore, more preferably 100 mPas ~ 50
It is in the range of 0 Pa · s.

The organopolysiloxane used in the present invention
Is represented by the following general formula (I).

[0010]

Embedded image

(Wherein R ¹ is a divalent hydrocarbon group, R ² ,
R ³ is a monovalent hydrocarbon group, R ⁴ is hydrogen or a monovalent hydrocarbon group, 1 is an integer of 0 to 4, m is an integer of 100 to 10,000, and a is 0
Or 1)

The divalent hydrocarbon group represented by R ¹ in the formula includes an alkylene group such as a methyl group, an ethylene group, a propylene group and a butylene group, and an arylene group such as a phenylene group.

The monovalent hydrocarbon group represented by R ² includes an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, an alkenyl group such as a vinyl group and an allyl group,
Examples include an aryl group such as a phenyl group, or a group in which a hydrogen atom of these groups is partially substituted with a halogen atom or the like.

Further, examples of the hydrolyzable group represented by OR ³ group include an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group and a propenoxy group.

Such an organopolysiloxane is represented by the following general formula (III):

Embedded image

(Wherein, R is a monovalent hydrocarbon group similar to R ^2, and n is a positive integer) and a diorganopolysiloxane in which both ends of the molecular chain are blocked with hydroxyl groups.

B) The following general formula (IV)

Embedded image

A condensation reaction of a reactive silane compound having two or three alkoxysilyl hydrolyzable groups in one molecule and having an amino group as another reactive group in the absence or presence of a catalyst represented by Can be synthesized.

The reactive silane compound represented by the general formula (IV) includes (β-aminoethyl) -β-aminoethyl trialkoxysilane and (β-aminoethyl)-
γ-aminopropyl trialkoxysilane, (γ-aminopropyl) -β-aminoethyl trialkoxysilane, (γ-aminopropyl) -γ-aminopropyl trialkoxysilane, aminopropyl trialkoxysilane, aminopropylmethyl dialkoxysilane , N-methylaminopropyltrimethoxysilane, N-benzylaminopropyltrimethoxysilane and the like.

Examples of the catalyst used include amines, carboxylic acids and metal carboxylate salts such as zinc, tin and iron.

The molar ratio of the alkoxysilane compound having an amino group / SiOH in the above condensation reaction should be at least 1, preferably in the range of 1 to 10.

Although it is not essential, it is preferable to remove the alcohol by-produced in the above condensation reaction.

Next, the mixing ratio of the composition of the present invention is shown.
Is as follows. 100 parts by weight of the organopolysiloxane represented by the above general formula (I)

C) The following general formula (II)

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Wherein R ⁵ is a monovalent hydrocarbon group, R ³ is a monovalent hydrocarbon group or an alkoxy-substituted carbon group, and a is 0 or 1.
Or a partially hydrolyzed condensate thereof

D) A moisture-curing catalyst represented by a moisture-curable organopolysiloxane composition comprising 0 to 10 parts by weight.

Here, the component (c) serves to cure the composition according to the present invention and act as a crosslinking agent for forming a rubber elastic body.

Examples of the component (c) include tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane, and methylcellosolve orthosilicate; methyltrimethoxysilane; methyltriethoxysilane;
Examples include trifunctional alkoxysilanes such as aminopropyltrimethoxysilane and 3-acryloylpropyltrimethoxysilane, and partially hydrolyzed condensates thereof.

These may be used alone or in combination of two or more. Further, in order to impart a low modulus to the cured rubber elastic body, a diphenyldimethoxysilane, dimethyldimethoxysilane or the like may be used. Functional alkoxysilanes may be additionally added.

As the moisture curing catalyst of component (d) to be added to the composition of the present invention, known ones can be used. For example, lead-2-ethyl octoate, dibutyltin diacetate, dibutyltin dilaurate, butyl Tin tri-2-ethylhexoate, iron-2-ethylhexoate, cobalt-2-ethylhexoate, manganese-2-ethylhexoate, zinc-2-ethylhexoate, caprylic acid Metal salts of organic acid carboxylic acids such as tin, tin naphthenate, tin oleate, tin butylate, zinc naphthenate, cobalt naphthenate, zinc stearate; tetrabutyl titanate, tetra-2-ethylhexyl titanate, triethanolamine titanate , Tetra (isopropenyloxy) titanate, diisopropoxybis (acetoacetic acid) Til) Titanium esters such as titanium and diisopropoxybis (acetylacetone) titanium; organic titanium compounds such as organosiloxytitanium and β-carbonyltitanium; alkoxyaluminum compounds; quaternary ammonium salts such as benzyltriethylammonium acetate; Lower fatty acid salts of alkali metals such as potassium, sodium acetate and lithium oxalate; and dialkylhydroxyamines such as dimethylhydroxyamine and diethylhydroxyamine.

These moisture curing catalysts are preferably used in an amount of 0 to 10 parts by weight, particularly 0 to 5 parts by weight, based on the total weight of the oligomer. If the amount is too large, the curing will be too fast or the storage stability will be poor. Become.

The composition according to the present invention basically comprises the above-mentioned components. If necessary, the flow characteristics before curing are improved, and the rubber-like elastic body after curing is imparted with necessary mechanical properties. For this purpose, a fine powdered inorganic filler can be added.

As the inorganic filler, fumed silica, fine quartz powder, calcium carbonate, fumed titanium dioxide, diatomaceous earth, aluminum hydroxide, fine alumina, magnesia, zinc oxide, zinc carbonate, and the like are used. Examples thereof include silanes, silazanes, low-polymerization degree siloxanes, organic compounds, and the like, which are surface-treated.

To the composition of the present invention, an organic solvent, a fungicide, a flame retardant, a plasticizer, a thixotropy-imparting agent, a curing accelerator, a pigment and the like can be added.

The composition according to the present invention can be obtained by mixing each component and, if necessary, various additives in a state where moisture is shut off.

The obtained composition is stored as it is in a closed container, and is used as a so-called one-part room temperature-curable organopolysiloxane composition which cures to a rubber-like elastic material when exposed to moisture in the air at the time of use. be able to.

[0037]

(Production of organopolysiloxane)

Production Example 1 Silanol-terminated polydimethylsiloxane 10 having a viscosity of 5 Pa · s
15 g of 3-aminopropyltrimethoxysilane is added to 00 g, and the mixture is stirred and reacted at 100 ° C. for 6 hours in a nitrogen atmosphere. Then, vacuum was applied to remove by-produced methanol and excess 3-aminopropyltrimethoxysilane, and the viscosity was 8 Pa · s.
A polydimethylsiloxane oil (A) having an amino group and a methoxysilyl group at the end of the product was obtained.

When this polymer (A) and tetraisopropoxy titanate were mixed at a ratio of 100: 1, the viscosity was not immediately increased, but was cured after one day. From this, it was confirmed that the OH group at the terminal of the polymer was replaced with a -OSiC ₃ H ₆ NH ₂ (OCH ₃ ) ₂ group.

Production Example 2 Silanol-terminated polydimethylsiloxane 10 having a viscosity of 10 Pa · s
20 g of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane was added to
Stir at 6 ℃ for 6 hours. Thereafter, vacuum was applied to remove by-produced methanol and excess aminoethylaminopropyltrimethoxysilane to obtain a polydimethylsilicone oil (B) having a viscosity of 15 Pa · s and having an amino group and a methoxysilyl group at the terminal.

When this polymer (B) was mixed with tetotaisopropoxytitanate at a ratio of 100: 1, it was found that the OH group at the terminal of the polymer was -OSiC ₃ H ₆ NHC ₂ H ₄ NH ₂ (OC
H ₃ ) was confirmed to be substituted by _two groups.

Production Example 3 Silanol-terminated polydimethylsiloxane 10 having a viscosity of 5 Pa · s
75 g of methyltrimethoxysilane is added to 00 g, and the mixture is charged into a reactor equipped with a reflux condenser, and stirred and reacted at 140 ° C. for 12 hours. Thereafter, the mixture was heated to 120 ° C. under a reduced pressure of 20 mmHg to remove methanol by-produced and excess methyltrimethoxysilane. The obtained polymer (C) had a viscosity of 6 Pa · s and was mixed with tetraisopropoxytitanate at a ratio of 100: 1. This indicates that the OH group at the polymer terminal is -OSiCH ₃ (OC
H ₃ ) ₂ was confirmed to be substituted.

Production Example 4 Silanol-terminated polydimethylsiloxane 10 having a viscosity of 10 Pa · s
80 g of methyltrimethoxysilane and 4 g of ethylenediamine as a catalyst were added to 00 g, and the mixture was charged into a reactor equipped with a reflux condenser, and stirred at 70 ° C. for 6 hours. Then 20mm
The mixture was heated to 95 ° C. under a reduced pressure of Hg to remove methanol by-produced and excess methyltrimethoxysilane and ethylenediamine. The obtained polymer (D) had a viscosity of 11 Pa · s and was mixed with tetraisopropoxytitanate at a ratio of 100: 1. This indicates that the OH group at the polymer terminal is -OSiCH ₃ (OC
H ₃ ) was confirmed to be substituted with _two groups.

Example 1 100 g of the polymer obtained in Production Example 1 was treated with 5 g of dry silica surface-treated with 5 g of methyltrimethoxysilane and dimethyldichlorosilane, and dibutyltin dilaterate was used as a moisture curing catalyst.
0.5 g was added, and the mixture was stirred and mixed until the mixture became uniform during the replacement with nitrogen to obtain a moisture-curable silicone composition.

Comparative Example 1 100 g of the polymer obtained in Production Example 3 was treated with 5 g of dry silica surface-treated with 5 g of methyltrimethoxysilane and dimethyldichlorosilane, and dibutyltin dilaterate was used as a moisture curing catalyst.
0.5 g was added, and the mixture was stirred and mixed until the mixture became uniform during the replacement with nitrogen to obtain a moisture-curable silicone composition.

Example 2 To 100 g of the polymer obtained in Production Example 2, 5 g of dry silica surface-treated with phenyltrimethoxysilane and dimethyldichlorosilane, and 0.2 g of dibutyltin methoxide as a moisture curing catalyst were added. Then, the mixture was stirred and mixed until it became uniform to obtain a moisture-curable silicone composition.

Comparative Example 2 To 100 g of the polymer obtained in Production Example 4, 5 g of 3-aminopropyltrimethoxysilane, 5 g of dry silica surface-treated with dimethyldichlorosilane, and 0.2 g of dibutyltin dimethoxide as a moisture curing catalyst were added. The moisture-curable silicone composition was obtained by stirring and mixing until uniform during the replacement.

Example 3 To 100 g of the polymer obtained in Production Example 2, 5 g of 3-aminopropyltrimethoxysilane, 5 g of dry silica surface-treated with dimethyldichlorosilane, and 0.2 g of dibutyltin dimethoxide as a moisture curing catalyst were added. The moisture-curable silicone composition was obtained by stirring and mixing until uniform during the replacement.

Comparative Example 3 5 g of phenyltrimethoxysilane and 5 g of dry silica surface-treated with dimethyldichlorosilane and 0.2 g of dibutyltin methoxide as a moisture curing catalyst were added to 100 g of the polymer obtained in Production Example 4, and the mixture was purged with nitrogen. Then, the mixture was stirred and mixed until it became uniform to obtain a moisture-curable silicone composition.

The resin compositions obtained in these Examples and Comparative Examples were filled in a container having a depth of 5 mm × 150 mm × 150 mm and cured at room temperature for 7 days. Hardness of the obtained cured product (JIS hardness A
Type), tensile strength, elongation, and shear adhesive strength were measured, and the results are shown in Table 1 below.

[0050]

[Table 1]

[0051]

In summary, according to the present invention, a room temperature-curable organopolysiloxane composition having excellent storage stability under sealed conditions and excellent adhesion to an adherend can be obtained.

Claims (2)

(57) [Claims] 1. A compound represented by the following general formula (I): (Wherein, R ¹ is a divalent hydrocarbon group, R ² and R ³ are monovalent hydrocarbon groups, R ⁴ is hydrogen or a monovalent hydrocarbon group, l is an integer of 0 to 4, m is 10 100 parts by weight of an organopolysiloxane represented by the following general formula (II): (Wherein R ⁵ is a monovalent hydrocarbon group, R ³ is a monovalent hydrocarbon group or an alkoxy-substituted hydrocarbon group, and a is 0 or 1) or a partial hydrolytic condensation thereof. Curable organopolysiloxane composition comprising 0 to 20 parts by weight of a moisture curing catalyst. 2. The method of claim 1, wherein the organopolysiloxane is represented by the following general formula (III): (Wherein R is a monovalent hydrocarbon group similar to that of R ² and n is a positive integer) represented by the following general formula (IV): Embedded image (Wherein, R ¹ is a divalent hydrocarbon group, and R ² and R ³ are monovalent
R ⁴ is hydrogen or a monovalent hydrocarbon group, l is
An integer of 0 to 4, a is has two or three hydrolyzable groups alkoxysilyl groups in one molecule represented by a 0 or 1), and the reactive silane compound having an amino group as the other reactive group Is synthesized by reacting the compound in the absence or presence of a catalyst.