JPS6359423B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to radiation curable organopolysiloxane compositions. Prior to the present invention, for example, Bruner
Room temperature vulcanizable organopolysiloxane compositions, such as those shown in US Pat. No. 3,070,555, were based on the moisture curing of mixtures of silanol-terminated polydiorganosiloxanes and acyloxysilanes. Although these moisture-curable organopolysiloxanes have been found to be useful in a variety of applications, acetic acid is evolved during curing, resulting in undesirable odors and undesirable reactions between acetic acid and various substrates. arise. No. 3,816,282 to Viventi, assigned to the present applicant, discloses that organopolysiloxanes can be radiation cured with good results using mercaptopolysiloxanes and free radical generators. ing. US Patent No. 4101513 to Fox et al.
No. 2, No. 1, No. 2, No. 1, No. 1, No. 1, No. 1, No. 1, No. 2, No. 2, No. 1, No. 2, No. 1, No. 1, No. 1, No. 2, No. 1, No. 2, No. 1, No. 2, No. 2, No. 1, No. 1, No. 2, No. 1, No. 2, and No. 2, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, and No. 1, No. 1, 2002, 2003 and 2002, 2003, and 2000, confirm that onium catalysts of groups A, A, and A are useful for the condensation of hydrolyzable silanes. The present invention provides a mixture of a, silanol-terminated polydiorganosiloxane and an alkoxysilane.
The present invention was made based on the discovery that when used in combination with an onium salt of an a or a group element, a radiation-curable organopolysiloxane composition that does not exhibit an acetic acid odor and can be cured by both ultraviolet and visible light can be obtained. Unlike the compositions of the Veventay patent, the radiation-curable organopolysiloxane compositions of the present invention are based on silanol condensation.
If visible light curing is desired, a suitable sensitizing organic dye can be used in combination with the onium salts mentioned above. The radiation-curable organopolysiloxane composition of the present invention comprises (A) 100 parts of a silanol-terminated organopolysiloxane consisting essentially of chemically bonded diorganosiloxy units of the formula: R ₂ SiO (1); (B) 2 ~200 parts of an alkoxysilane of the following formula: (R ¹ O) _a (R ² ) _b Si (2), (C) 0.1 to 20 parts of onium salts of elements of groups a, a, and a, and (D) 0 Contains ~20 parts of organic sensitizer. Here, R is a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group, and R ¹ is
C _(1-12) alkyl group, R ² is R group and C _(1-8)
selected from glycidyl alkyl groups, a is 2-4
b is an integer having a value of 0 to 2, and the sum of a and b is equal to 4. The groups represented by R in formulas (1) and (2) include, for example, monovalent aryl groups and monovalent halogenated aryl groups, such as phenyl, xylyl, chlorophenyl, naphthyl; aralkyl groups, such as benzyl, phenylethyl; aliphatic groups and aliphatic groups; Cyclic groups such as alkyl, alkenyl, cycloalkyl, chloroalkyl, particularly methyl, ethyl, propyl, chloropropyl, vinyl, allyl, trifluoropropyl, cyclohexyl, and the like, and cyanoethyl, cyanopropyl, cyanobutyl, and the like.
Examples of the group represented by R ¹ include methyl, ethyl, and propyl. The onium salt used in the practice of the present invention is represented by the formula: [Y] ⁺ [J] ^- (3). where J is a non-nucleophilic counterion,
More details later. Y is an aromatic halonium cation of the formula: [(R ³ ) _c (R ⁴ ) _d D] (4), and the formula: [(R ³ ) _f (R ⁵ ) _g (R ⁶ ) _h E] (5) and an aromatic group A cation of the formula: [(R ³ ) _j (R ⁷ ) _k (R ⁸ ) _n G] (6) . Here R ³ is a monovalent aromatic group,
R ⁴ is a divalent aromatic group, R ⁵ and R ⁷ are alkyl,
a monovalent aliphatic group selected from cycloalkyl and substituted alkyl; R ⁶ and R ⁸ are polyvalent organic groups selected from aliphatic groups and aromatic groups and forming a heterocyclic or fused ring structure with E or G; and D
is a halogen group, for example I, E are group a elements selected from N, P, AsSb and Bi, G is S, Se
and a group a element selected from Te. c is an integer of 0 or 2, d is an integer of 0 or 1, when c is 0, d is 1, when c is 2, d is 0, f is an integer equal to 0 to 4, g is 0 to An integer equal to 2, h is an integer equal to 0 to 2, and the sum of f+g+h is
have a value such that the sum of the valences of R ³ , R ⁵ and R ⁶ is 4, that is, 1 greater than the bond valence of E, j is an integer equal to 0 to 3, k is an integer equal to 0 to 2, m is an integer of 0 or 1, and the sum of j+k+m is
The total valence of R ³ , R ⁷ and R ⁸ has a value of 3, that is, 1 greater than the bond valence of G. The groups represented by R ³ may be the same or different and are aromatic carbocyclic or heterocyclic groups having 6 to 20 carbon atoms, such as C _(1-12) alkoxy, C _(1-12) alkyl,
A monovalent group selected from nitro, chloro, etc.
It may be replaced with four. R ³ is preferably phenyl, chlorophenyl, nitrophenyl, methoxyphenyl, pyridyl and the like. The group represented by R ⁴ is a divalent group, e.g.

【formula】

[Formula] (Q' in the formula is as described below), and the R ⁵ and R ⁷ groups are C _(1-12) alkyl, such as methyl, ethyl, substituted alkyl, such as -C ₂ H ₄ OCH ₃ , ―
CH ₂ COOC ₂ E ₅ , ―CH ₂ COCH ₃ , R ⁶ and
The ^R8 group has the following structural formula:

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

It is a group of [Formula]. where Q' is selected from -O-, ( _-CH2 ) _-o , =N-R' and -S-, n is an integer equal to 1 to 4, and Z is -O
-, -S- and

[Formula] and R' is selected from hydrogen, C _(1-8) alkyl, C _(6-13) aryl, etc. The non-nucleophilic counterion represented by J in formula (3) is the MQ _d anion, where M represents a metal or metalloid, Q represents a halogen group, and d is an integer, e.g.
It is an integer of ~6. J in formula (3) may also include non-nucleophilic counterions such as perchlorate groups, CF ₃ SO ₃ ^- , C ₆ H ₄ SO ₃ ^- , and the like. J in formula (3) can also be a halogen counterion, such as Cl ⁻ , Br ⁻ , F ^{− ,} etc., and a nitrate group, a phosphate group, etc. The metal or metalloid represented by M in the non-nucleophilic counterion MQ _d contained in J in formula (3) is a transition metal, e.g.
Sb, Fe, Sn, Bi, Al, Ga, In, Ti, Zr, Sc,
V, Cr, Mn, Cs, rare earth elements such as lanthanides, specifically Cd, Pr, Nd, etc., actinides, specifically Th, Pa, U, Np, etc., and metalloids such as B, P , As, etc. The complex anions represented by MQ _d are, for example, BF ₄ ^- , PF ₆ ^- , AsF ₆ ^- ,
SbF ₆ ⁻ , FeCl ₄ ⁻ , SnCl ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ =, etc. Examples of halonium salts included in formula (3) and having a cation of formula (4) are as follows.

【formula】

【formula】

【formula】

【formula】

[Formula] etc. Examples of group a onium salts included in formula (3) and having a cation of formula (5) are as follows. Such. Examples of group a onium salts included in formula (3) and having a cation of formula (6) are as follows. A silanol-terminated organopolysiloxane consisting essentially of chemical bonding units of formula (1) has the following formula: (R in the formula is as defined above, q is about 5
There are linear diorganopolysiloxanes with average values equal to ~3000). The fluid preferably has a viscosity in the range of about 2000 to 50000 centipoise measured at 25°C. These silanol-terminated fluids are prepared by treating higher molecular weight organopolysiloxanes, such as dimethylpolysiloxane, with water in the presence of mineral acids or basic catalysts to adjust the viscosity of the polymer to the desired range. Formula (7)
Methods for forming such high molecular weight organopolysiloxanes for use in preparing silanol-terminated diorganopolysiloxanes are well known. For example, a low molecular weight hydrolysis product can be produced by hydrolyzing a diorganohalosilane, specifically dimethyldichlorosilane, diphenyldichlorosilane, methylvinyldichlorosilane, etc. or a mixture thereof. After this, a high molecular weight organopolysiloxane can be obtained by equilibration.
High molecular weight polymers can also be obtained by equilibration of cyclopolysiloxanes such as octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane or mixtures thereof. Preferably, these polymers are stripped of equilibrated catalyst prior to use by standard methods such as those set forth in commonly assigned US Pat. No. 3,153,007 to Boot. A silanol-terminated organopolysiloxane having a viscosity of 1200 centipoise or less is substantially of the formula (1)
It can be formed by treating an organopolysiloxane consisting of chemically bonded units with steam under pressure. Other methods that can be used to form silanol-terminated organopolysiloxanes are detailed in Warrick, US Pat. No. 2,607,792 and British Patent No. 835,790. Examples of the alkoxysilane of formula (2) include methyltrimethoxysilane, dimethyldimethoxysilane,
Orthosilicate methyl ester, orthosilicate ethyl ester, n-butyltrimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, diphenyldiethoxysilane, and high condensates such as dimethyltetramethoxydisiloxane, There is 2-glycidyltrimethoxysilane. Organic dyes that can be used in the practice of this invention include:
Examples include acridine orange, acridine yellow, phosphine R, benzoflavin, hematoporphyrin, 9,10-diethylanthracene, Michler's ketone, setoflavin T, perylene, and coronene. In practicing the present invention, the components of the mixture,
For example, a silanol fluid, an alkoxysilane, and an onium salt can be mixed together. If the onium salt and the silanol-terminated polydiorganosiloxane, or "silanol fluid," do not form a solution, the onium salt can first be dissolved in a diluent that is inert to the components of the mixture. Suitable inert diluents are alcohols such as ethanol, ethyl acetate, ether, acetonitrile and the like. The alkoxysilane can be added to the silanol fluid before or with the onium salt. If visible light curing is desired, the organic dye is added to the other ingredients in complete or partial darkness to minimize premature activation of the onium salt. Various fillers and pigments can be incorporated into the radiation curable compositions, such as silica, talc, mica, titanium dioxide, gypsum, iron oxide, alumina, wood flour, glass fibers, graphite, carbon black, fly ash, and the like. The amount of filler added can vary within wide limits. However, since the type and amount of filler added affects the curing efficiency of the mixture, the amount added can vary within a wide range according to application requirements and acceptable curing times. Typical mixtures contain, for example, 1 to 30 parts of filler per 100 parts of silanol fluid. The composition of the present invention can be used as a construction sealant, caulking agent, and the like. Compositions of the invention can be stored indefinitely. but,
If a sensitizing organic dye is used in the mixture, it is necessary to shield the curable organopolysiloxane composition from daylight to minimize activation of the onium salt. In order that those skilled in the art may better understand how to carry out the invention, the following examples are provided, but not as a limitation.
Shown as an example. All parts are by weight. Example 1 10 parts of a silanol-terminated polydimethylsiloxane fluid having a viscosity of 35000 centipoise and an OH content of 0.09%, 1 part of orthosilicate ethyl ester, and di(4-n-butylphenyl hexafluoroarsenate).
A mixture of 0.3 parts of iodonium was applied as a 3 mil thin film on a glass plate and GE was applied from a distance of 7 inches.
Irradiation was performed using a H3T7 medium pressure mercury arc lamp. After an irradiation time of 20 seconds, a rubbery thin film was obtained. A copper wire was immersed in the UV-curable organopolysiloxane, and the covered wire was irradiated with ultraviolet light in the same manner as above. After 10 seconds of irradiation, an adhesive elastic silicone rubber coating was obtained on the copper wire, which was effective as an insulating coating. Example 2 The procedure of Example 1 was repeated, but in this example methyltriethoxysilane was used instead of orthosilicate ethyl ester. The curable silicone composition was applied to a glass plate as a 1 mil thin film and irradiated using the same procedure as in Example 1 from a distance of 7 inches. A rubbery crosslinked thin film was obtained after 10 seconds of irradiation. The same curable silicone composition was applied as a 0.1 mil thin film to Kraft paper and cured as described above. It was not possible to permanently adhere pressure-resistant adhesive coated paper to this kraft paper. The coating did not stain and could not be rubbed off. Example 3 0.2 g of di(4-n-heptylphenyl)iodonium hexafluoroarsenate, 10 g of difunctional hydroxyl-terminated polydimethylsiloxane fluid having a viscosity of 35000 cp, and orthosilicate methyl ester 1
A solution of g was prepared. This mixture was coated as a 1 mil thin film on an aluminum plate and illuminated with a GEH3T7 arc lamp from a 3 inch distance. A 15 second irradiation was sufficient to obtain a tack-free, rubbery coating. Example 4 A polymerizable mixture was prepared using 1 part of a hydroxyl-terminated polydimethylsiloxane fluid having a viscosity of 47,000 cp, 5 parts of 2-glycidyltrimethoxysilane, and 0.1 part of a sulfurized phenyltriphenylsulfonium salt of the formula: The above mixture was applied as a 1 mil thin film on a glass plate.
After irradiation for 1.0 minutes, a transparent hard thin film was obtained. Irradiation was performed using a GH H3T7 medium pressure mercury arc lamp. The above sulfurized phenyltriphenylsulfonium salt was produced as follows. A mixture of 19.6 parts of 86% potassium hydroxide, 33 parts of thiophenol and about 120 parts of dimethylacetamide was heated to a temperature of 120° C. with stirring to remove water. After collecting about 6.5 parts of water,
26.3 parts of p-dibromobenzene was added to this mixture, and the resulting mixture was heated to reflux. After refluxing for 6 hours, the reaction mixture was allowed to cool and 300 parts of water were added.
A brown solid was obtained which was filtered and washed several times with water. The product was then dried. According to this production method, 34.7 parts of 1,4-dithiophenoxybenzene was obtained. A mixture of 7.35 parts of the above disulfide, 11.75 parts of diphenyliodonium hexafluoroarsenate and 0.2 parts of copper benzoate was heated to 120 DEG C. for 3 hours.
The resulting reaction mixture was washed several times with about 50 parts of diethyl ether, and the remaining solid was recrystallized from 95% ethanol. A very light brown crystalline product was obtained with a yield of 45%, which had a melting point of 69-75° and the elemental analysis values were as follows: Calculated values C51.3%, H3.50%, S11.43% Actual values C51.21%, H3.59%, S11.37% Based on the manufacturing method, the following formula: A triarylsulfonium salt of was obtained. Example 5 To the reaction mixture of Example 4, 0.02 part of perylene was added as a sensitizer. This mixture was coated onto a glass plate, which was then stacked with another glass plate to form a glass-to-glass bond. GE EBR375W
A permanent bond was obtained by irradiating the mixture through the glass for 1.5 minutes using a photographic visible light flood lamp. Example 6 4 parts ethyltrimethoxysilane to 1 part
47,000 centipoise of hydroxyl terminated polydimethylsiloxane and 0.1 part of didodecylphenyliodonium hexafluoroantimonate were added. This solution was coated as a 2 mil thin film on an aluminum plate and the GEH3T7 was coated from a 6 inch distance.
Irradiation was performed using a medium pressure mercury arc lamp. After continuous irradiation for 1 minute, the thin film was cured into a transparent hard film. Example 7 0.01 part of perylene was added to the solution of Example 6, and a thin film was coated on an aluminum plate in the same manner as described above.
The thin film was irradiated with visible light using a GE EBR374W photographic flat lamp. Using the above lamp at a distance of 4 inches, a clear hard film was produced after 1 minute of irradiation. Example 8 The procedure of Example 6 was repeated, but in this example the photoinitiator was of the following formula: I replaced it with salt. 1.5 to obtain a non-stick hard coating
It took several minutes of curing time. Although the above examples relate only to a few of the many radiation-curable silicone compositions encompassed within the scope of the present invention, the present invention includes silanol-terminated polydiorganosiloxanes having units of formula (1), It is to be understood that a wide variety of silicone compositions are encompassed which contain alkoxysilanes, aromatic onium salts as described above, and optionally organic sensitizers.

Claims (1)

[Scope of Claims] 1 (A) has a viscosity in the range of 2,000 to 50,000 centipoise at 25°C and is substantially of the following formula: R ₂ SiO (wherein R is a monovalent hydrocarbon group and a monovalent halogen); ( ^B ₎ 100 parts of a silanol ^- terminated organopolysiloxane consisting of diorganosiloxy units selected ^from hydrogenated _hydrocarbon groups; _(1-12) alkyl group, R ² is selected from the above R group and C _(1-8) glycidyl alkyl group, a is an integer equal to 1 to 4, and b is an integer equal to 0 to 2. , the sum of a+b equals 4), (C) an onium salt of a, a or group a element;
and (D) 0 to 20 parts of an organic sensitizer. 2. The composition of claim 1, wherein the silanol-terminated polydiorganosiloxane is a silanol-terminated polydimethylsiloxane. 3. The composition according to claim 1, wherein the alkoxysilane is orthosilicate ethyl ester. 4 The onium salt is hexafluoroarsenic acid di(4
-n-butylphenyl) iodonium. 5 The onium salt is The composition according to claim 1. 6 The onium salt is The composition according to claim 1. 7 The onium salt is The composition according to claim 1. 8. The composition of claim 1, wherein the dye is perylene. 9. The composition of claim 1, wherein the dye is Michler's ketone.