JP3329007B2 - Moisture-curable and photocurable silicone compositions - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicone composition which can be cured by both moisture curing and light curing mechanisms.

[0002]

2. Description of the Related Art Silicone is made of a flexible cured product and its elasticity, making use of its impact resistance, vibration resistance,
It is a substance with high industrial use value such as thermal stress resistance. However, the conventional one-pack silicone cures by condensation reaction due to moisture, and it takes a considerable time to completely cure the silicone. Therefore, in recent years, silicones that are cured by light irradiation have been developed. For example, there is one in which a silanol-terminated organopolysiloxane is treated with an aminoalkoxysilane to change the terminal to an amino group, and glycidyl (meth) acrylate is added to enable photocuring (JP-A-55-11).
2262). However, the reactivity between the glycidyl group and the amino group is poor, and the reaction requires a long-time heating reaction at a high temperature or the use of a catalyst. In addition, regarding the addition reaction of glycidyl (meth) acrylate, since the reactivity of the epoxy group and the acrylic group is similar, the acrylic group may undergo a Michael addition reaction and the photocurability may not be provided.

In Japanese Patent Application Laid-Open (JP-A) No. 61-145227, a silicone oil having an amino group is reacted with a vinyl group-containing isocyanate. But not suitable for potting and bonding. Also, if the amino group is a primary amino group in the reaction between the vinyl group-containing isocyanate and the amino group-terminated silicone oil, a urea bond is formed, so that the hydrogen bond increases and the viscosity becomes very high, making handling difficult. There is a problem.

[0004] An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and in particular, to provide a silicone composition which has excellent photocurability and moisture curability, is easy to produce, and has good handleability. .

[0005]

According to the present invention, there is provided a compound of the general formula

[0006]

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(Wherein R ¹ is a divalent hydrocarbon group, R ² and R ³ are monovalent hydrocarbon groups, X is a hydrolyzable group, l is an integer of 0 to 4, m is 1 An integer from 10,000 to a
Addition reaction products of an organopolysiloxane and a vinyl group-containing isocyanate having an amino group at both molecular ends represented by a 0 or 1), said addition reaction product per
0.01 to 10 parts by weight of a photopolymerization catalyst and 0.01 to 10 parts by weight
The present invention relates to a moisture-curable and photo-curable silicone composition comprising a part by weight of a moisture-curing catalyst.

Next, the components constituting the silicone composition of the present invention will be described. The organopolysiloxane having amino groups at both molecular ends has the above general formula, and the divalent hydrocarbon group represented by R ¹ in the formula includes an alkylene group such as a methylene group, an ethylene group, and a propylene group. , An arylene group such as a phenylene group, and the like. Examples of the monovalent hydrocarbon group represented by R ² and R ³ include an alkyl group such as a methyl group, an ethyl group, a propyl group, and a butyl group, a vinyl group, and an allyl group. Alkenyl groups such as,
Benzyl group, substituted alkyl group

[0009]

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Alternatively, groups in which a hydrogen atom of these groups is partially substituted with a halogen atom or the like are exemplified. Further, the hydrolyzable group represented by X is a methoxy group,
Examples thereof include an alkoxy group such as an ethoxy group and a propoxy group, or an oxime group, an amino group, a propenoxy group, and an acetoxy group.

Such an organopolysiloxane can be prepared by a conventionally known method, for example, by the formula

[0012]

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(Wherein R has the same meaning as R ² described above, and n represents a positive integer) and a diorganopolysiloxane in which both terminals of the molecular chain are blocked with a hydroxyl group is represented by the following formula: It can be synthesized by reacting a reactive silane compound having two or three decomposable groups and having a secondary amino group as another reactive group. The use of a secondary amino group has an effect of reducing hydrogen bonding between molecules as compared with the primary amino group, and lowering the viscosity.

The reactive silane compound used in the above reaction includes N-benzylaminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, (CH ₃ O) ₃ Si—C ₃ H ₆ —NH—C ₂ H ₄ -
_{NH-C 3 H 6 -S 2} - (OCH 3) 3, (CH 3 O)
_{3 Si-C 3 H 6 -NH} -C 3 H 6 -Si (OCH 3)
₃ and so on

[0015]

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Secondary amino silane compounds obtained by the Michael addition reaction of primary amino silane compounds with various acrylate monomers are also exemplified.

The vinyl group-containing isocyanate is a compound having at least one vinyl group which is a photocurable functional group in one molecule and an isocyanate group as a functional group for reaction with an amino group. Isocyanate groups such as methacryloyl isocyanate, 2-isocyanate ethyl methacrylate, isopropenyl-2,2-dimethylbenzyl isocyanate, and 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, One or more and 2-hydroxyethyl methacrylate,
There is an isocyanate group-containing (meth) acrylate obtained by the reaction of a (meth) acrylate having a hydroxyl group such as 2-hydroxypropyl methacrylate.

The addition reaction is generally carried out by mixing the amino group-containing organopolysiloxane with the amino group in an amount such that the isocyanate group of the vinyl group-containing isocyanate sufficiently reacts with the amino group of the amino group-containing organopolysiloxane. Usually, the latter is added in an amount of 2 mol or more per 1 mol of the former, and reacted under slight heating such as around 50 ° C.

Known photopolymerization catalysts and moisture curing catalysts to be added to the thus obtained addition reaction product can be used.

Examples of the photopolymerization catalyst include dimethoxyacetophenone, 1-hydroxycyclohexylphenylketone, diethoxyacetophenone, acetophenone, propiophenone, benzophenone, xanthol, fluorein, benzaldehyde, anthraquinone, camphorquinone, 2,4,6- Trimethylbenzoyldiphenylphosphine oxide triphenylamine, carbazole, 3-methylacetophenone, 4-methylacetophenone, 3-bentylacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4 −
Allyl acetophenone, 4-methylbenzophenone, 4
-Chloro-4-benzylbenzophenone, 3-chloroxantone, 3,9-dichloroxantone, 3-chloro-8-nonylxantone, benzoyl, benzoin methyl ether, benzoin butyl ether, bis (4
-Dimethylaminophenyl) ketone, benzylmethoxy ketal, 2-chlorothioxatone and the like. The addition amount of the photopolymerization catalyst may be in the range of 0.01 to 10% by weight based on the total weight of the oligomers present in the composition, since it is only necessary to slightly light-sensitize the system. The content is preferably in the range of 1 to 5% by weight.

Examples of the moisture curing catalyst include lead-2-ethyl octoate, dibutyltin diacetate, dibutyltin dimethoxide, dibutyltin dilaurate, butyltin tri-2-ethylhexoate, iron-2-ethylhexoate, Cobalt-2-ethylhexoate, manganese-2-ethylhexoate, zinc-2-ethylhexoate, stannous caprylate, tin naphthenate, tin oleate, tin butylate, tin naphthenate, naphthene Metal lead of organic acid carboxylic acid such as zinc acid, cobalt naphthenate, zinc stearate; organic titanate such as tetrabutyl titanate, tetra-2-ethylhexyl titanate, triethanolamine titanate, tetra (isopropenyloxy) titanate; Organosiloxy titanium, β-cal Organic titanium compounds such as nil titanium; alkoxyaluminum compounds; quaternary ammonium salts such as benzyltriethylammonium acetate; lower fatty acids of alkali metals such as potassium acetate, sodium acetate and lithium oxalate; dialkyls such as dimethylhydroxyamine and diethylhydroxyamine Hydroxylamine; and the like. The amount of the moisture curing catalyst used is 0.01 to 1 with respect to the total weight of the oligomer.
0 parts by weight, especially 0.1 to 5 parts by weight is preferred.

The composition of the present invention basically comprises the above-mentioned components. If necessary, various additives and inorganic fillers may be used in combination. Particularly, the combined use of fumed silica is preferable from the viewpoint of improving the physical properties of the cured product.

Further, not only a photoinitiator but also a thermal polymerization initiator or a rexox polymerization initiator can be used in combination with the radical polymerization initiator to give thermal polymerization, rexox polymerization or the like. Then, for further adjusting the viscosity, dimethyl silicone oil or a reactive diluent may be added. Examples of the reactive diluent include compounds containing an unsaturated (vinyl double bond) group, compounds containing a hydrolyzable group, and the like. Specific examples include isobornyl acrylate, isobornyl methacrylate, and the like. (Meth) acrylates such as dicyclopentanyl acrylate, dicyclopentenyl acrylate, phenoxy acrylate,

[0024]

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A compound containing an unsaturated group and a hydrolyzable group such as

[0026]

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Examples of the silane coupling agent include:

[0028]

【Example】

Production Example 1. 20 g of N-benzylaminopropyltrimethoxysilane is added to 1000 g of terminal silanol polydimethylsiloxane (molecular weight 30,000), and the mixture is stirred and reacted at 100 ° C. for 2 hours while being replaced with nitrogen. Thereafter, the mixture was evacuated to remove excess N-benzylaminopropyltrimethoxysilane to obtain a 8000 cps-terminated N-benzylaminopolydimethylsiloxane.

Production Example 2. 27 g of N-benzylaminopropyltrimethoxysilane is added to 1000 g of terminal silanol polydimethylsiloxane (molecular weight: 20,000), and the mixture is stirred and reacted at 100 ° C. for 2 hours in a nitrogen atmosphere. Thereafter, vacuum was applied to remove excess N-benzylaminopropyltrimethoxysilane, and the viscosity was 1000 cps at the terminal N.
-Benzylaminopolydimethylsiloxane was obtained.

Embodiment 1 Resin 10 obtained in Production Example 1
0 g of 2-isocyanatoethyl methacrylate 1.1
g was added and the mixture was stirred and reacted for 1 hour at 50 ° C. while replacing with nitrogen. Further, 1 g of 1-hydroxycyclohexylphenyl ketone as a photocuring catalyst and 0.5 g of dibutyltin dilaurate as a moisture curing catalyst were added to obtain a moisture and ultraviolet curable silicone composition. The viscosity was 15000 cps.

Embodiment 2 FIG. Resin 10 obtained in Production Example 2
0 g to 2-isocyanatoethyl methacrylate 1.6
The reaction was stirred for 1 hour at room temperature while replacing with nitrogen. Further, 1 g of dimethoxyacetophenone and 0.5 g of a moisture curing catalyst dibutyltin dilaurate were added as a photocuring catalyst to obtain a moisture- and ultraviolet-curable silicone composition. The viscosity was 2000 cps.

Comparative Example 1 The viscosity of the terminal aminopolydimethylsiloxane obtained by changing N-benzylaminopropyltrimethoxysilane of Production Example 1 to 3-aminopropyltrimethoxysilane was 20,000 cps. In addition, as a result of performing the same as in Example 1, the viscosity was 45,000.
cps.

Comparative Example 2 The viscosity of the terminal aminopolydimethylsiloxane obtained by changing N-benzylaminopropyltrimethoxysilane of Production Example 2 to 3-aminopropyltrimethoxysilane was 10,000 cps. In addition, as a result of performing the same as in Example 2, the viscosity was 20,000.
cps.

Production Example 3 To 31,000 g of 3-aminopropyltrimethoxysilane and isoboronyl acrylate were added to 1000 g of terminal silanol polydimethylsiloxane (molecular weight 20,000), and 1
Stir at 00 ° C for 2 hours. Thereafter, methanol was removed as a by-product while applying a vacuum to obtain a terminally substituted aminopolydimethylsiloxane having a viscosity of 900 cps.

Embodiment 3 FIG. Resin 10 obtained in Production Example 3
0 g to 2-isocyanatoethyl methacrylate 1.6
g was added thereto, and the mixture was stirred and reacted at room temperature for 1 hour while purging with nitrogen.
Further, 1 g of 1-hydroxycyclohexyl phenyl ketone as a photocuring catalyst and 0.5 g of dibutyltin dilaurate as a moisture curing catalyst were added to obtain a moisture and ultraviolet curable silicone composition. The viscosity of the obtained composition is 1
It was 200 cps.

The resin composition obtained in each of the examples was filled in a volume of 5 mm × 150 mm × 150 mm in depth and 4 k
When irradiation was performed with a W high-pressure mercury lamp at 150 mW / cm ² × 20 seconds, curing occurred. The hardness (JIS hardness A type), tensile strength, and elongation of the obtained cured product were measured. The moisture-cured product not irradiated with ultraviolet light has a temperature of 25 ° C. and a humidity of 60
%, The surface was hardened 24 hours later, leaving no tack. Hardness after 7 days (J
IS hardness A), tensile strength and elongation were measured.

[0037]

[Table 1]

────────────────────────────────────────────────── ─── Continued from the front page Examiner Yoko Nakajima (56) References JP-A-61-145227 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 83/08 C08F 299 / 08

Claims (1)

(57) [Claims] 1. A compound of the general formula (Wherein R ¹ is a divalent hydrocarbon group, R ² and R ³ are monovalent hydrocarbon groups, X is a hydrolyzable group, and l is 0 to 4)
, M is an integer of 1 to 10000, a is 0 or 1), an addition reaction product of an organopolysiloxane having an amino group at both ends of the molecule and a vinyl group-containing isocyanate, and the addition reaction product 0.01 to 10 weights per
The amount of the photopolymerization catalyst and moisture curing and silicone composition capable of photocuring, characterized in that it consists of 0.01 to 10 parts by weight moisture curing catalyst.