JP3291759B2 - 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 between the epoxy group and the acrylic group is similar, the acrylic group may react and the photocurability may not be given.

[0003] 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 is excellent in photocurability and moisture curability and can be easily produced.

[0004]

SUMMARY OF THE INVENTION The present invention is a hydrolyzable
And -NH (R ⁴ ) (where R
⁴ represents a monovalent hydrocarbon group).
Organopolysiloxane and vinyl group-containing isocyanate
Group-containing organo obtained by the addition reaction of
Photopolymerization catalyst 0.01 per 100 parts by weight of polysiloxane
10 to 10 parts by weight and a moisture curing catalyst 0.01 to 10 parts by weight
The present invention relates to a moisture-curable and photo-curable silicone composition characterized by containing .

Next, components constituting the silicone composition of the present invention will be described.

A typical example of an organopolysiloxane having amino groups at both ends of the molecule is represented by the general formula:

Embedded image (Wherein R ¹ and R ³ are divalent hydrocarbon groups, R ² and R ⁴
Represents a monovalent hydrocarbon group; X represents a hydrolyzable group;
Is an integer of 0 to 4; m is an integer of 50 to 10000; a is 0 or 1); and the divalent hydrocarbon group represented by R ¹ in the formula is a methylene group. Examples thereof include an alkylene group such as an ethylene group and a propylene group, and an arylene group such as a phenylene group.
Examples of the monovalent hydrocarbon group represented by R ² include 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; an aryl group such as a phenyl group; Examples thereof include a group in which a hydrogen atom of a group is partially substituted with a halogen atom or the like. Examples of the hydrolyzable group represented by X include an alkoxy group such as a methoxy group, an ethoxy group, and a propoxy group, an oxime group, an amino group, a propenoxy group, and an acetoxy group.

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

Embedded image (Wherein, R has the same meaning as R ² described above, and n represents a positive integer). A diorganopolysiloxane in which both terminals of the molecular chain are blocked with a hydroxyl group and a hydrolyzable group in one molecule It can be synthesized by reacting two or three reactive silane compounds having an amino group as another reactive group.

The reactive silane compounds used in the above reaction include (β-aminoethyl) -β-aminoethyl trialkoxysilane, (β-aminoethyl) -γ-aminopropyl trialkoxysilane, and (γ-amino Propyl) -β-aminoethyl trialkoxysilane, (γ
-Aminopropyl) -γ-aminopropyl trialkoxysilane, aminopropyl trialkoxysilane, aminopropylmethyldialkoxysilane,

Embedded image And the like.

A 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-isocyanatoethyl methacrylate, isopropenyl-2,2-dimethylbenzyl isocyanate, and 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and 1,5-naphthalenediisocyanate; 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 product of the present invention is
This refers to an organopolysiloxane having a vinyl group formed by contacting an organopolysiloxane having a secondary amino group with an isocyanate group containing a vinyl group by bringing the latter into contact with a vinyl group-containing isocyanate. This addition reaction is usually carried out by mixing the amino group-containing organopolysiloxane with the vinyl group-containing isocyanate in an amount such that the amino group of the vinyl group-containing isocyanate sufficiently reacts with the amino group. 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-hydroxycyclohexylphenyl ketone, diethoxyacetophenone, acetophenone, propiophenone, benzophenone, xanthol, fluorein, benzaldehyde, anthraquinone, triphenylamine, carbazole, 3-methyl Acetophenone, 4-methylacetophenone, 3-bentylacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-allylacetophenone, 4-methylbenzophenone, 4-chloro-4-benzyl Benzophenone, 3-chloroxanthone, 3,9-dichloroxanthone, 3-chloro-8-nonylxanthone, benzoyl, benzoinmethone Ether, benzoin butyl ether, bis (4-dimethylaminophenyl) ketone,
Benzyl methoxy ketal, 2-chlorothioxatone and the like. With regard to the amount of addition of the photopolymerization catalyst is present in the composition it is only slightly light sensitive the system additional reaction
0.01 to 10 based on 100 parts by weight of the total weight of the reaction product
Although it may be in the range of parts by weight , it is generally preferred to be in the range of 0.1 to 5 parts by weight .

Examples of the moisture curing catalyst include lead-2-ethyl octoate, dibutyltin diacetate, dibutyltin dilaurate, butyltin tri-2-ethylhexoate, iron-2-ethylhexoate, and cobalt-2- Ethylhexoate, manganese-2-ethylhexoate,
Zinc-2-ethylhexoate, stannous caprylate,
Metal lead of organic acid carboxylic acid such as tin naphthenate, tin oleate, tin butylate, tin naphthenate, zinc naphthenate, cobalt naphthenate, zinc stearate; tetrabutyl titanate, tetra-2-ethylhexyl titanate, triethanol Organic titanates such as amine titanate and tetra (isopropenyloxy) titanate; organic titanium compounds such as organosiloxytitanium and β-carbonyltitanium; alkoxyaluminum compounds; quaternary ammonium salts such as benzyltriethylammonium acetate; potassium acetate; Alkali metal lower fatty acids such as sodium acetate and lithium oxalate; dialkylhydroxylamine such as dimethylhydroxyamine and diethylhydroxyamine; The amount of this moisture curing catalyst used depends on the addition reaction product
0.01 to 10 parts by weight per 100 parts by weight of the total weight of
And particularly preferably 0.1 to 5 parts by weight.

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

[0015] Further, not only a photoinitiator but also a thermal polymerization initiator or a rexox polymerization initiator may be used in combination as a radical polymerization initiator to impart thermal polymerization, rexox polymerization or the like. Then, for further adjusting the viscosity, dimethyl silicone oil or a reactive diluent may be added. Unsaturated (vinyl double bond) as reactive diluent
There are a compound containing a group, a compound containing a hydrolyzable group, and the like, specifically, isobornyl acrylate,
(Meth) acrylates such as isobornyl methacrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, phenoxy acrylate,

Embedded image Compounds containing an unsaturated group and a hydrolyzable group such as,

Embedded image And the like. The present invention
If a reactive diluent is added to the composition of
It needs to be added after the product has formed.

[0016]

EXAMPLES Production Example 1 Silanol-terminated polydimethylsiloxane (molecular weight 300)
00) 12 g of aminopropyltrimethoxysilane is added to 1000 g, and the mixture is stirred and reacted at 100 ° C. for 2 hours while replacing with nitrogen. Then, vacuum is applied to remove excess aminopropyltrimethoxysilane , and both ends have a viscosity of 15,000 cps.
Polydimethylsiloxane having an amino group at the end was obtained.

Production Example 2 Terminal silanol polydimethylsiloxane (molecular weight 300)
00) Add 15 g of aminoethylaminopropyltrimethoxysilane to 1000 g, and add
Stir for 2 hours. Then pulling a vacuum removes excess aminoethyl aminopropyl trimethoxy silane, poly-di <br/> methyl silicones having amino groups at both terminals of the viscosity 18000cps was obtained.

Example 1 To 100 g of the resin obtained in Production Example 1, 1.1 g of 2-isocyanatoethyl methacrylate was added, and 5 g of the resin was replaced with nitrogen.
Stir at 0 ° C for 1 hour to cause addition reaction, and
Methyl siloxane . Furthermore, as a photo-curing catalyst, 1
1 g of hydroxycyclohexyl phenyl ketone and 0.5 g of dibutyltin dilaurate as a moisture curing catalyst were added to obtain a moisture- and ultraviolet-curable silicone composition.

Example 2 To 100 g of the resin obtained in Production Example 1, 0.8 g of methacryloyl isocyanate was added, and the mixture was stirred for 1 hour at room temperature in a nitrogen atmosphere to carry out an addition reaction, whereby vinyl-containing polydimethylsiloxane was added.
Sun. Further, 40 g of 100 cps dimethyl silicone oil, 1 g of dimethoxyacetophenone as a photocuring catalyst and 0.5 g of a moisture curing catalyst dibutyltin dilaurate were added to obtain a moisture and ultraviolet curable silicone composition.

Example 3 To 100 g of the resin obtained in Production Example 2 was added 2 g of 2-isocyanatoethyl methacrylate, and the mixture was cooled to room temperature under nitrogen purge.
Addition reaction by stirring for hours
Siloxane . Further, 1 g of 1-hydroxycyclohexyl phenyl ketone as a photocuring catalyst and 0.5 g of tin octylate as a moisture curing catalyst were added to obtain a moisture- and ultraviolet-curable silicone composition.

Example 4 100 g of the resin obtained in Production Example 2 was added to isopropenyl-
3.8 g of 2,2-dimethylbenzyl isocyanate was added, and the mixture was stirred at 50 ° C. for 1 hour in a nitrogen purge to carry out an addition reaction.
A vinyl group-containing polydimethylsiloxane is used. further,
40 g of 100 cps dimethyl silicone oil, 1 g of dimethoxyacetophenone as a photocuring catalyst and 0.5 g of tin octylate as a moisture curing catalyst were added to obtain a moisture and ultraviolet curable silicone composition.

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.

[0023]

[Table 1]

(56) References JP-A-5-295272 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 83/08 C08G 18/61 C08G 18/81

Claims (2)

(57) [Claims] (1) a compound having a hydrolyzable group and
-NH (R ⁴ ) (where R ⁴ is a monovalent hydrocarbon group)
0.01 to 10 parts by weight of a photopolymerization catalyst and 100 parts by weight of a moisture-curing catalyst per 100 parts by weight of a vinyl-containing organopolysiloxane obtained by subjecting an organopolysiloxane having an amino group represented by 0.11 to 10 parts by weight of a moisture-curable and photocurable silicone composition. 2. The organopolysiloxane has a general formula: (Wherein R ¹ and R ³ are divalent hydrocarbon groups, R ² and R ⁴
Represents a monovalent hydrocarbon group; X represents a hydrolyzable group;
Is an integer of 0 to 4; m is an integer of 50 to 10000; and a is 0 or 1).