Curable organopolysiloxane composition containing novel adhesion promoter

There is disclosed a curable organopolysiloxane composition suitable for forming an adherent coating on metals which is durable under acidic conditions, said composition comprising: PA1 (A) an organopolysiloxane that contains at least 2 alkenyl groups in each molecule; PA1 (B) an organopolysiloxane that contains at least 2 silicon-bonded hydrogen atoms in each molecule; PA1 (C) a novel adhesion promoter; and PA1 (D) a hydrosilylation catalyst, wherein the adhesion promoter is prepared by reacting PA2 (a) an amine compound with the general formula EQU R.sub.n NH.sub.(3-n) in which R denotes a monovalent hydrocarbon group and n is 1 or 2, and PA1 (b) an aliphatically unsaturated epoxy compound, and, optionally, condensing the above reaction product with PA1 (c) a silicon compound that contains at least two silicon-bonded alkoxy groups in each molecule.

FIELD OF THE INVENTION 
The invention relates to a curable organopolysiloxane composition. More 
specifically, the invention relates to a curable organopolysiloxane 
composition containing a novel adhesion promoter which imparts an adhesive 
character to the composition which is durable under acidic conditions. 
BACKGROUND OF THE INVENTION 
Addition reaction-curing organopolysiloxane compositions cure relatively 
rapidly at room temperature or when heated, and for this reason have been 
broadly examined as protectants for metal surfaces. These compositions are 
composed of an organopolysiloxane that contains at least 2 alkenyl groups 
in each molecule, an organopolysiloxane that contains at least 2 
silicon-bonded hydrogen atoms in each molecule, and a hydrosilylation 
catalyst. 
However, addition reaction-curing organopolysiloxane compositions generally 
exhibit poor adhesion, and this deficiency has necessitated the addition 
of an adhesion promoter in order to equip these compositions with 
self-bondability. A variety of adhesion promoters are known for this 
purpose. The following have already been disclosed as curable 
organopolysiloxane compositions with improved self-bonding properties: 
curable organopolysiloxane compositions that contain acryloxy-functional 
or methacryloxy-functional organoalkoxysilane (Japanese Patent Publication 
Number Sho 51-28309, curable organopolysiloxane compositions that contain 
the reaction product from epoxy-functional alkoxysilane and 
alkenyl-containing siloxane (Japanese Patent Publication Number Sho 
52-48146 and Japanese Laid Open Patent Application Number Hei 1-85224, and 
adhesion promoter-containing curable organopolysiloxane compositions, for 
example, as disclosed in Japanese Laid Open Patent Application Number Sho 
54-80358, whose adhesion promoter is prepared, for example, by the 
reaction of aminoalkylalkoxysilane and epoxyalkylalkoxysilane (refer to 
Japanese Laid Open Patent Application Number Sho 48-75633 or by reacting 
alkoxysilane with (i) active hydrogen-containing amine compound or 
aminoalkylalkoxysilane and (ii) epoxy-functional organic compound or 
epoxyalkylalkoxysilane, with the proviso that at least one of (i) and (ii) 
is the alkoxysilane (refer to Japanese Laid Open Patent Application Number 
Sho 61-72077. 
When cured at around 150.degree. C., the curable organopolysiloxane 
compositions disclosed in Japanese Patent Publication Numbers Sho 51-28309 
and Sho 52-48146 and Japanese Laid Open Patent Application Number Hei 
1-85224 exhibit an excellent adhesiveness for substrates such as iron and 
aluminum, but exhibit an inadequate adhesiveness for substrates such as 
nickel-plated substrates and copper. As a result, when these compositions 
are adhered on the surface of a substrate chosen from the latter group, 
delamination occurs rather easily when the adherent is treated with an 
acidic aqueous solution. In the case of the adhesion promoters taught in 
Japanese Laid Open Patent Application Numbers Sho 48-75633 and Sho 
61-72077, foaming occurs when addition reaction-curing organopolysiloxane 
compositions that contain these adhesion promoters are subjected to heat 
curing since these adhesion promoters are extremely unstable because they 
contain both hydroxyl and silicon-bonded alkoxy in the molecule. 
SUMMARY OF THE INVENTION 
In specific terms, the present invention takes as its object the 
introduction of a highly adhesive curable organopolysiloxane composition 
whose adhesiveness is also very durable under acidic conditions as well as 
an adhesion promoter which imparts this superior adhesiveness to the 
composition. 
The invention relates to a curable organopolysiloxane composition that is 
composed of 
(A) 100 weight parts of an organopolysiloxane that contains at least 2 
alkenyl groups in each molecule; 
(B) an organopolysiloxane that contains at least 2 silicon-bonded hydrogen 
atoms in each molecule, in a quantity sufficient to give 0.3 to 5.0 moles 
of silicon-bonded hydrogen in component (B) per 1 mole of total alkenyl in 
the composition; 
(C) 0.3 to 10 weight parts of an adhesion promoter whose effective 
ingredient is the reaction product of 
a) an amine compound with the general formula 
EQU R.sub.n NH.sub.(3-n) 
wherein R denotes monovalent hydrocarbon groups and n is 1 or 2 and 
(b) an aliphatically unsaturated epoxy compound; and 
(D) a catalytic quantity of a hydrosilylation catalyst. The present 
invention also relates to the above-described curable organopolysiloxane 
composition wherein the adhesion promoter (C') is the reaction product 
obtained by subjecting the reaction product of 
(a) an amine compound with the general formula 
EQU R.sub.n NH.sub.93-n) 
wherein R denotes monovalent hydrocarbon groups and n is 1 or 2 and 
(b) an aliphatically unsaturated epoxy compound, to a condensation reaction 
with 
(c) a silicon compound that contains at least two silicon bonded alkoxy 
groups in each molecule. 
The present invention is the subject of Japanese Patent Applications Hei 
5-311263 and Hei 5-311264, the full specifications of which are hereby 
incorporated by reference.

DETAILED DESCRIPTION OF THE INVENTION 
The organopolysiloxane comprising component (A), which is the base material 
of the present composition, consists of an organopolysiloxane that 
contains at least 2 alkenyl groups in each molecule. The alkenyl in 
component (A) is specifically exemplified by vinyl, allyl, butenyl, 
pentenyl, hexenyl, and decenyl, with vinyl being preferred. The bonding 
position for the alkenyl in component (A) is not critical, and the alkenyl 
may be bonded at the molecular chain terminals, or in nonterminal 
positions on the molecular chain, or at both positions. The non-alkenyl 
silicon-bonded organic groups in component (A) are specifically 
exemplified by alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, 
hexyl, and so forth; cycloalkyl groups such as cyclohexyl, cycloheptyl, 
and so forth; aryl groups such as phenyl, tolyl, xylyl, and so forth; 
aralkyl groups such as benzyl, phenethyl, and so forth; and halogenated 
alkyl groups such as 3,3,3-trifluoropropyl, chloromethyl, and so forth. 
Methyl preferably makes up at least half of the non-alkenyl silicon-bonded 
organic groups in component (A) because this affords good economics and an 
excellent adhesiveness. The molecular structure of component (A) is also 
not critical and is exemplified by straight-chain, partially branched 
straight-chain, branched, cyclic, and network structures. Straight-chain 
structures are preferred. No particular restrictions apply to the 
viscosity of component (A), but its viscosity at 25.degree. C. preferably 
falls in the range of 100 to 1,000,000 centipoise since this affords 
excellent handling characteristics on the part of the resulting curable 
organopolysiloxane composition. 
Subject organopolysiloxane (A) is exemplified as follows: 
trimethylsiloxy-endblocked methylvinylpolysiloxanes; 
trimethylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxane copolymers; 
trimethylsiloxy-endblocked methylphenylsiloxanemethylvinylsiloxane 
copolymers; 
dimethylvinylsiloxy-endblocked dimethylpolysiloxanes; 
dimethylvinylsiloxy-endblocked dimethylsiloxanemethylvinylsiloxane 
copolymers; 
dimethylvinylsiloxy-endblocked methylphenylpolysiloxanes; 
dimethylvinylsiloxy-endblocked methylphenylsiloxanemethylvinylsiloxane 
copolymers; 
silicone resins composed of the (CH.sub.3).sub.3 SiO.sub.1/2, 
(CH.sub.3).sub.2 (CH.sub.2 .dbd.CH)SiO.sub., and SiO.sub.4/2 units; and 
silicone resins composed of the (CH.sub.3).sub.3 SiO.sub.1/2, 
(CH.sub.3).sub.2 (CH.sub.2 .dbd.CH)SiO.sub.1/2, 
CH.sub.3 SiO.sub.3/2, and SiO.sub.4/2 units. 
Component (A) may also consist of combinations of two or more of the 
organopolysiloxanes provided above as examples. 
The organopolysiloxane (B), which is a crosslinker for the present 
composition, consists of an organopolysiloxane that contains at least 2 
silicon-bonded hydrogen atoms in each molecule. The bonding position for 
the silicon-bonded hydrogen in component (B) is not critical, and the 
silicon-bonded hydrogen may be bonded at the molecular chain terminals, or 
in nonterminal position on the molecular chain, or at both positions. The 
silicon-bonded organic groups in component (B) are specifically 
exemplified by alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, 
hexyl, and so forth; cycloalkyl groups such as cyclohexyl, cycloheptyl, 
and so forth; aryl groups such as phenyl, tolyl, xylyl, and so forth; 
aralkyl groups such as benzyl, phenethyl, and so forth; and halogenated 
alkyl groups such as 3,3,3-trifluoropropyl, chloromethyl, and so forth. 
Methyl preferably makes up at least half of the silicon-bonded organic 
groups in component (B) because this affords good economics and an 
excellent adhesiveness. The molecular structure of component (B) is also 
not critical and is exemplified by straight-chain, partially branched 
straight-chain, branched, cyclic, and network structures. Straight-chain 
structures are preferred. No particular restrictions apply to the 
viscosity of component (B), but its viscosity at 25.degree. C. preferably 
falls in the range of 5 to 1,000,000 centipoise since this affords 
excellent handling characteristics on the part of the resulting curable 
organopolysiloxane composition. 
Subject organopolysiloxane (B) is exemplified as follows: 
trimethylsiloxy-endblocked methylhydrogenpolysiloxanes; 
trimethylsiloxy-endblocked dimethylsiloxanemethylhydrogensiloxane 
copolymers; 
dimethylhydrogensiloxy-endblocked dimethylpolysiloxanes; 
dimethylhydrogensiloxy-endblocked methylhydrogenpolysiloxanes; 
dimethylhydrogensiloxy-endblocked dimethylsiloxanemethylhydrogensiloxane 
copolymers; 
cyclic methylhydrogenpolysiloxanes; 
cyclic dimethylsiloxane-methylhydrogensiloxane copolymers; 
tetrakis(dimethylhydrogensiloxy) silane; 
silicone resins composed of the (CH.sub.3).sub.2 HSiO.sub.1/2, 
(CH.sub.3).sub.3 SiO.sub.1/2, and SiO.sub.4/2 units; and 
silicone resins composed of the (CH.sub.3).sub.2 HSiO.sub.1/2, 
(CH.sub.3).sub.3 SiO.sub.1/2, CH.sub.3 Si O.sub.3/2, and SiO.sub.4/2 
units. 
Component (B) may also consist of combinations of two or more of the 
organopolysiloxanes provided above as examples. 
Component (B) must be added to the present composition in a quantity that 
yields 0.3 to 5.0 moles of silicon-bonded hydrogen in component (B) per 1 
mole of total alkenyl in the present composition. The curability of the 
curable organopolysiloxane composition is sharply reduced when the 
addition of component (B) provides less than 0.3 moles of silicon-bonded 
hydrogen from component (B) per 1 mole of total alkenyl in the present 
composition. At the other extreme, the cured organopolysiloxane will 
exhibit sharply reduced physical properties when the addition of component 
(B) provides more than 5.0 moles of silicon-bonded hydrogen from component 
(B) per 1 mole of total alkenyl in the present composition. 
The novel adhesion promoter comprising component (C) is the component that 
imparts self-bondability to the present composition. The characteristic 
feature of this adhesion promoter (C) is that its effective ingredient is 
the reaction product of 
(a) an amine compound with the general formula 
EQU R.sub.n NH.sub.(3-n) 
wherein R denotes a monovalent hydrocarbon groups and n is 1 or 2 and 
(b) an aliphatically unsaturated epoxy compound. 
The amine compound (a) is described by the following general formula 
EQU R.sub.n NH.sub.(3-n) 
wherein R denotes a monovalent hydrocarbon group, and is specifically 
exemplified by alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, 
hexyl, and so forth; alkenyl groups such as vinyl, allyl, butenyl, 
pentenyl, hexenyl, and so forth; aryl groups such as phenyl, tolyl, xylyl, 
naphthyl, and so forth; and aralkyl groups such as benzyl, phenethyl, and 
so forth. Allyl and phenyl are preferred. The subscript n in the preceding 
formula is 1 or 2: when n is 1, the amine compound is a primary amine 
compound, and when n is 2, the amine compound is a secondary amine 
compound. 
Subject amine compounds (a) are specifically exemplified by methylamine, 
ethylamine, n-propylamine, n-butylamine, tert-butylamine, dimethylamine, 
diethylamine, dipropylamine, di(n-butyl)amine, di(tert-butyl)amine, 
allylamine, butenylamine, diallylamine, methylaniline, allylaniline, and 
aniline. Allylamine and aniline are preferred. 
The epoxy compound (b) is an aliphatically unsaturated epoxy compound. 
Epoxy compound (b) is specifically exemplified by allyl glycidyl ether, 
butenyl glycidyl ether, pentenyl glycidyl ether, 
4-vinyl-1,2-epoxycyclohexane, 4-allyl-1,2-epoxycyclohexane, 
4-butenyl-1,2-epoxycyclohexane, 4-pentenyl-1,2-epoxycyclohexane, glycidyl 
methacrylate, and glycidyl acrylate. Allyl glycidyl ether is preferred. 
The adhesion promoter (C) is prepared by reacting the nitrogen-bonded 
hydrogen in component (a) with the epoxy group in component (b). This 
reaction proceeds at room temperature, but is accompanied by a substantial 
evolution of heat which creates the risk of a violent reaction course. The 
reaction is therefore preferably run by the gradual dropwise addition of 
component (b) into component (a) or the gradual dropwise addition of 
component (a) into component (b). Component (b) is preferably added to the 
preparative reaction so as to give a slight molar excess of epoxy groups 
of component (b) over nitrogen-bonded hydrogen of component (a). Even more 
desirably, component (b) is added in quantities that give 1.01 to 2 moles 
epoxy group of component (b) per mole nitrogen-bonded hydrogen of 
component (a). The basis for this preferred addition of component (b) is 
that the complete consumption of the nitrogen-bonded hydrogen in component 
(C) yields a substantial improvement in the curability of the present 
composition. There are no particular restrictions on the temperature in 
the subject reaction, but the recommended method consists of the gradual 
dropwise addition of component (a) while component (b) is heated to at 
least 70.degree. C. Following completion of the reaction, the adhesion 
promoter (C) can be purified by distilling off unreacted component (b) 
under reduced pressure. 
When allyl glycidyl ether is used as component (b) for the adhesion 
promoter (C), a reaction product with the following general formula will 
be the main component of the resulting adhesion promoter. 
##STR1## 
wherein R and n have their previously defined meanings. 
The use of the above-mentioned adhesion promoter (C') is preferred in order 
to provide the curable organopolysiloxane composition of the invention 
with-adhesiveness for a particularly broad range of substrates. The 
effective ingredient in adhesion promoter (C') consists of the reaction 
product obtained by the condensation of a silicon compound (c) that 
contains at least 2 silicon-bonded alkoxy groups in each molecule, with 
the aforementioned reaction product from the amine compound (a) and 
aliphatically unsaturated epoxy compound (b). 
Alkoxysilanes that contain at least two silicon-bonded alkoxy groups in 
each molecule and alkoxysilylalkyl-alkoxysilanes that contain at least two 
silicon-bonded alkoxy groups in each molecule may be cited as examples of 
the silicon compound (c). The alkoxysilanes encompassed by component (c) 
are specifically exemplified by 
tetramethoxysilane, 
tetraethoxysilane, 
methyltrimethoxysilane, 
ethyltrimethoxysilane, 
vinyltrimethoxysilane, 
allyltrimethoxysilane, 
phenyltrimethoxysilane, 
dimethyldimethoxysilane, 
methylvinyldimethoxysilane, 
methylphenyldimethoxysilane, 
diphenyldimethoxysilane, 
3-glycidoxypropyltrimethoxysilane, and 
3-methacryloxypropyltrimethoxysilane. 
Tetramethoxysilane is preferable. Specific examples of 
alkoxysilylalkylalkoxysilanes encompassed by component (c) include 
bis(trimethoxysilyl)ethane, 
bis(trimethoxysilyl)propane, 
bis(trimethoxysilyl)butane, 
bis(trimethoxysilyl)pentane, 
bis(trimethoxysilyl)hexane, 
bis(triethoxysilyl)ethane, 
bis(triethoxysilyl)propane, 
bis(methyldimethoxysilyl)ethane, and 
bis(methyldimethoxysilyl)propane, 
Bis(trimethoxysilyl)hexane is preferable. Combinations of two or more of 
the preceding alkoxysilanes and/or alkoxysilylalkyl-alkoxysilanes may also 
be used as component (c). 
When allyl glycidyl ether is used as component (b) for adhesion promoter 
(C'), the resulting adhesion promoter has the following general formula 
##STR2## 
wherein R and n have their previously defined meanings and X denotes an 
alkoxysilyl group or alkoxysilylalkylsilyl group. The alkoxysilyl groups 
represented by X can be expressed by the following general formula 
EQU --SiR.sup.2.sub.a (OR.sup.1).sub.(3-a) 
in which R.sup.1 =alkyl, R.sup.2 =monovalent hydrocarbon group, and a is an 
integer from 0 to 2. 
R.sup.1 in the preceding formula denotes alkyl, which is specifically 
exemplified by methyl, ethyl, propyl, butyl, pentyl, and hexyl, with 
methyl being preferred. R.sup.2 in the preceding formula denotes 
monovalent hydrocarbon groups, which are specifically exemplified in this 
case by the same monovalent hydrocarbon groups as listed above. The 
subscript a in the formula is an integer from 0 to 2. The alkoxysilyl 
groups encompassed by X are specifically exemplified by trimethoxysilyl, 
triethoxysilyl, methyldimethoxysilyl, vinyldimethoxysilyl, 
phenyldimethoxysilyl, dimethylmethoxysilyl, methylvinylmethoxysilyl, 
methylphenylmethoxysilyl, diphenylmethoxysilyl, 
3-glycidoxypropyldimethoxysilyl, and 3-methacryloxypropyldimethoxysilyl. 
The alkoxysilylalkylsilyl groups represented by X can be expressed by the 
following general formula 
EQU --SiR.sup.2.sub.b (OR.sup.1).sub.(2-b) --R.sup.3 --SiR.sup.2.sub.a 
(OR.sup.1).sub.(3-a) 
wherein R.sup.1, R.sup.2 and a have their previously defined meanings. 
R.sup.3 in the preceding formula is an alkylene group, which is 
specifically exemplified by methylene, ethylene, methylmethylene, 
methylethylene, propylene, butylene, pentylene, hexylene, heptylene, and 
octylene, with hexylene being preferred. The subscript b is also an 
integer from 0 to 2. Specific alkoxysilylalkylsilyl groups encompassed by 
X include 
trimethoxysilylethyldimethoxysilyl, 
trimethoxysilylpropyldimethoxysilyl, 
trimethoxysilylbutyldimethoxysilyl, 
trimethoxysilylpentyldimethoxysilyl, 
trimethoxysilylhexyldimethoxysilyl, 
triethoxysilylethyldiethoxysilyl, 
triethoxysilylpropyldiethoxysilyl, 
methyldimethoxysilylethyldimethoxysilyl, 
methyldimethoxysilylpropyldimethoxysilyl, 
methyldimethoxysilylbutyldimethoxysilyl, 
methyldimethoxysilylpentyldimethoxysilyl, 
methyldimethoxysilylhexyldimethoxysilyl, 
dimethylmethoxysilylethyldimethoxysilyl, 
dimethylmethoxysilylpropyldimethoxysilyl, 
dimethylmethoxysilylbutyldimethoxysilyl, 
dimethylmethoxysilylpentyldimethoxysilyl, and 
dimethylmethoxysilylhexyldimethoxysilyl. 
This reaction consists of an alcohol-liberating condensation reaction 
between the silicon-bonded alkoxy in component (c) and the hydroxyl in the 
reaction product that is the main component of component (C). This 
condensation reaction can be accelerated by an alcohol-exchange catalyst. 
The desired reaction product can be obtained by removing the alcohol 
by-product by heating and/or the application of reduced pressure. This 
reaction can be expressed, for example, by the following equation. 
##STR3## 
wherein R, R.sup.1, X and n have their previously defined meanings. 
There are no particular restrictions on the aforementioned alcohol-exchange 
catalyst as long as said catalyst is a compound that accelerates alcohol 
exchange. Specific examples of such catalysts include basic catalysts such 
as sodium hydroxide, potassium hydroxide, cesium hydroxide, potassium 
methylate, and so forth, and titanium catalysts such as 
tetrabutoxytitanium, and so forth. When the nitrogen in the adhesion 
promoter is strongly basic, the adhesion promoter will itself function as 
an alcohol-exchange catalyst, thus eliminating the need for a separate 
addition of alcohol-exchange catalyst. This reaction will proceed even at 
room temperature, but only very slowly. Accordingly, it is desirable to 
run this reaction by heating the system to a temperature of 50.degree. C. 
to 200.degree. C. It will also be desirable to remove the alcohol 
by-product at ambient pressure or under reduced pressure. 
Component (C) or (C') is added to the present composition at 0.3 to 10 
weight parts per 100 weight parts component (A). The self-bondability of 
the curable organopolysiloxane composition drops off sharply at component 
(C) or (C') additions of less than 0.3 weight parts per 100 weight parts 
component (A). On the other hand, the physical properties of the cured 
organopolysiloxane will be substantially impaired when component (C) or 
(C') is added in excess of 10 weight parts per 100 weight parts component 
(A). 
The hydrosilylation catalyst comprising component (D) is a catalyst that 
accelerates the cure of the present composition. This hydrosilylation 
catalyst is exemplified by platinum catalysts such as platinum black, 
platinum supported on silica micropowder, platinum supported on carbon 
powder, chloroplatinic acid, alcohol solutions of chloroplatinic acid, 
platinum/olefin complexes, platinum/alkenylsiloxane complexes, 
platinum/beta-diketone complexes, platinum/phosphine complexes, and so 
forth; rhodium catalysts such as rhodium chloride, rhodium 
chloride/di(n-butyl)sulfide complex, and so forth; and palladium 
catalysts. In the present invention, component (D) is preferably a 
platinum catalyst when the monovalent hydrocarbon group bonded to the 
nitrogen in component (C) is alkyl or aryl. On the other hand, component 
(D) is preferably a rhodium catalyst when the monovalent hydrocarbon group 
bonded to the nitrogen in component (C) is alkenyl. Component (D) should 
be added to the present composition in a catalytic quantity. In specific 
terms, the preferred addition gives 0.1 to 500 ppm catalyst metal in the 
composition. 
The curable organopolysiloxane composition according to the invention is 
prepared by mixing the aforementioned components (A) through (D) to 
homogeneity. Components which may be added to the invention composition on 
an optional basis are exemplified by inorganic fillers such as dry-process 
silica, wet-process silica, crystalline silica, diatomaceous earth, silica 
balloons, calcium carbonate, carbon black, titanium dioxide, aluminum 
oxide, zinc oxide, and so forth, and also colorants, heat stabilizers, 
antioxidants, and flame retardants. An acetylenic compound, amine 
compound, mercaptan compound, phosphorus compound, or the like, may be 
added in order to control the cure rate of the curable organopolysiloxane 
composition of the present invention. The following may be added in order 
to obtain additional improvements in the self-bondability of the-curable 
organopolysiloxane composition of the invention: 
3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 
vinyltrimethoxysilane, allyltrimethoxysilane, tetramethoxysilane, 
1,5-bis(trimethoxysilyl)hexane, 1,2-dimethyl-1,1,2,2-tetramethoxydisilane, 
or the reaction mixture from 3-glycidoxypropyltrimethoxysilane and 
methylvinylcyclosiloxane. Unreactive silicone oils may be added in order 
to improve the physical properties of the cured organopolysiloxane. 
The curable organopolysiloxane composition of the invention can be prepared 
by mixing the various components described hereinbefore to homogeneity. No 
specific restrictions apply to the equipment to be used for preparation of 
the curable organopolysiloxane composition of the invention, and, for 
example, a planetary mixer, kneader mixer, screw mixer, impeller mixer, 
static mixer, 2-roll mill, 3-roll mill, or twin-screw extruder can be 
used. 
The curable organopolysiloxane composition of the invention can be cured at 
room or elevated temperature. However, in order to obtain an excellent 
self-bondability, the preferred curing procedure consists of heating the 
curable organopolysiloxane composition on the adherent to 70.degree. C. to 
200.degree. C. 
The curable organopolysiloxane composition of the invention as described 
above exhibits an excellent self-bondability to metal surfaces. In 
particular, it is strongly adhesive to the surface of copper, which is 
widely used in the electrical and electronic sectors. The curable 
organopolysiloxane composition of the invention can therefore be used as a 
mask or solder resist during the partial plating of copper conductors. The 
curable organopolysiloxane composition of the invention exhibits a 
superior adhesiveness that appears immediately upon curing, and its 
adhesiveness is also very durable to challenge by acidic conditions. As a 
result of these attributes, this composition can be used for various types 
of masks, sealants, potting materials, coatings, and so forth. 
EXAMPLES 
The curable organopolysiloxane composition of the present invention is 
described below in greater detail through working examples. The 
adhesiveness was evaluated as follows: either immediately after the 
curable organopolysiloxane composition had been cured into silicone rubber 
by heating on the adherent, or after acid challenge of the adhesiveness, 
the silicone rubber was peeled off using a spatula and the performance at 
this point was rated. Good adhesion by the silicone rubber to the adherent 
was scored as "++"; partial delamination was scored as "+"; and complete 
delamination was scored as "x". 
REFERENCE EXAMPLE 1 
285 g of allyl glycidyl ether was placed in a 500-Ml four-necked flask 
equipped with a stirrer, thermometer, reflux condenser, and addition 
funnel. 57 g of allylamine was then added dropwise from the addition 
funnel while regulating the system so the temperature did not exceed 
150.degree. C. The system was reacted for 2 hours at 150.degree. C. after 
addition of the allylamine. This was followed by removal of the unreacted 
allyl glycidyl ether by stripping to give a moderately brown liquid 
product. Analysis of this liquid product by .sup.1 H-nuclear magnetic 
resonance spectroscopic analysis (NMR), infrared spectroscopic analysis 
(IR), and gas chromatographic/mass spectrometric analysis (GC/MASS) 
confirmed it to be an adhesion promoter (designated as adhesion promoter 
(A)) whose main component was the following compound. 
##STR4## 
REFERENCE EXAMPLE 2 
201 g of allyl glycidyl ether was placed in a 500-Ml four-necked flask 
equipped with a stirrer, thermometer, reflux condenser, and addition 
funnel. After the system had been heated to 140.degree. C., 65.9 g of 
aniline was added dropwise from the addition funnel while regulating the 
system so the temperature did not exceed 160.degree. C. The system was 
reacted for 2 hours at 150.degree. C. after addition of the aniline. This 
was followed by removal of the unreacted allyl glycidyl ether by stripping 
to give a moderately brown liquid product. This liquid product was 
distilled at 150.degree. C./0.2 torr using a thin-film distillation 
apparatus to give a moderately yellow liquid product. Analysis of this 
liquid product by NMR, IR, and GC/MASS confirmed it to be an adhesion 
promoter (designated as adhesion promoter (B)) whose main component was 
the following compound. 
##STR5## 
REFERENCE EXAMPLE 3 
100 g of the compound synthesized in Reference Example 1 and 213.3 g of 
tetramethoxysilane were placed in a 500-Ml four-necked flask equipped with 
a stirrer, thermometer, and distillation setup. 0.04 g of potassium 
hydroxide was added to this system, and the system was heated while 
stirring. During this period, the methanol by-product was removed through 
a 20-cm Vigreux distillation column. The system was cooled to room 
temperature after methanol evolution had ceased. The potassium hydroxide 
was then neutralized by the addition of 1.1 g of propionic acid. The 
unreacted propionic acid and tetramethoxysilane were removed by stripping 
to give a liquid product. Analysis of this liquid product by IR confirmed 
the disappearance of the peaks attributable to hydroxyl. Analysis of this 
liquid product by NMR and GC/MASS confirmed it to be an adhesion promoter 
(designated as adhesion promoter (C)) whose main component was the 
following compound. 
##STR6## 
REFERENCE EXAMPLE 4 
51.1 g of the compound prepared in Reference Example 2, 100 g of 
bis(trimethoxysilyl)hexane, and 1.5 g of tetrabutoxytitanium were placed 
in a 500-Ml four-necked flask equipped with a stirrer, thermometer, and 
distillation setup, and the system was heated to 150.degree. C. under 
reduced pressure produced by an aspirator. The methanol by-product was 
recovered in a dry ice-acetone trap, and 11 g of methanol by-product was 
obtained. After methanol production had ceased, the system was cooled to 
give a liquid product. Analysis of this liquid product by IR confirmed the 
disappearance of the peaks attributable to hydroxyl. Analysis of this 
liquid product by NMR and GC/MASS confirmed it to be an adhesion promoter 
(designated as adhesion promoter (D)) whose main component was the 
following compound. 
##STR7## 
REFERENCE EXAMPLE 5 
495.6 g of 3-glycidoxypropyltrimethoxysilane and 221 g of 
3-aminopropyltriethoxysilane were placed in a 1-liter four-necked flask 
equipped with stirrer and thermometer. Stirring this system for 3 hours at 
100.degree. C. produced a viscous adhesion promoter (E). Analysis of this 
adhesion promoter by IR confirmed the disappearance of the peaks 
attributable to the N--H bond. 
EXAMPLE 1 
A curable organopolysiloxane composition in accordance with the invention 
was prepared by mixing the following to homogeneity: 100 weight parts of 
dimethylvinylsiloxy-endblocked dimethylpolysiloxane with an average degree 
of polymerization of 300 and a vinyl group content of 0.24 weight %; a 
trimethylsiloxy-endblocked methylhydrogenpolysiloxane with an average 
degree of polymerization of 40 and a silicon-bonded hydrogen content of 
1.5 weight % (this component was added in sufficient quantity to give 1.5 
moles silicon-bonded hydrogen per mole total alkenyl in the composition); 
11 weight parts of fumed silica (specific surface=200 m.sup.2 /g) whose 
surface had been treated with hexamethyldisilazane; 2.2 weight parts of 
adhesion promoter (A); rhodium chloride/di(n-butyl)sulfide complex in an 
amount sufficient to give a rhodium metal content in the composition of 10 
ppm; and 0.02 weight parts of phenylbutynol. 
This curable organopolysiloxane composition was coated on each of the 
substrates shown in Table 1 and cured to give the silicone rubber by 
heating for 1 hour at 150.degree. C. The silicone rubber was in each case 
peeled from the substrate using a spatula in order to evaluate the 
adhesion. The results are reported in Table 1. 
EXAMPLE 2 
A curable organopolysiloxane composition in accordance with the invention 
was prepared by mixing the following to homogeneity: 100 weight parts of 
dimethylvinylsiloxy-endblocked dimethylpolysiloxane with an average degree 
of polymerization of 300 and a vinyl group content of 0.24 weight %; a 
trimethylsiloxy-endblocked methylhydrogenpolysiloxane with an average 
degree of polymerization of 40 and a silicon-bonded hydrogen content of 
1.5 weight % (this component was added in sufficient quantity to give 1.5 
moles silicon-bonded hydrogen per mole total alkenyl in the composition); 
11 weight parts of fumed silica (specific surface=200 m.sup.2 /g) whose 
surface had been treated with hexamethyldisilazane; 2.2 weight parts of 
adhesion promoter (B); a chloroplatinic acid/vinylsiloxane complex in an 
amount sufficient to give a platinum metal content in the composition of 
10 ppm; and 0.02 weight parts of phenylbutynol. 
This curable organopolysiloxane composition was coated on each of the 
substrates shown in Table 1 and cured to give the silicone rubber by 
heating for 1 hour at 150.degree. C. The silicone rubber was in each case 
peeled from the substrate using a spatula in order to evaluate the 
adhesion. The results are reported in Table 1. 
EXAMPLE 3 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 1, but in this case using adhesion promoter (C) in place of the 
adhesion promoter (A) used in Example 1. The adhesiveness was evaluated as 
in Example 1, and these results are reported in Table 1. 
EXAMPLE 4 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 2, but in this case using adhesion promoter (D) in place of the 
adhesion promoter (B) used in Example 2. The adhesiveness was evaluated as 
in Example 2, and these results are reported in Table 1. 
COMATIVE EXAMPLE 1 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 2, but in this case using adhesion promoter (E) in place of the 
adhesion promoter (B) used in Example 2. The adhesiveness was evaluated as 
in Example 2, and these results are reported in Table 1. 
COMATIVE EXAMPLE 2 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 2, but in this case omitting the adhesion promoter (B) used in 
Example 2. The adhesiveness was evaluated as in Example 2, and these 
results are reported in Table 1. 
TABLE 1 
______________________________________ 
comparative 
present invention 
examples 
Ex. Ex. Ex. Ex Comp. Comp. 
1 2 3 4 Ex. 1 Ex. 2 
______________________________________ 
adhesion promoter 
A B C D E none 
appearance of the 
++ ++ ++ ++ x ++ 
silicone rubber foaming 
adhesion 
aluminum ++ ++ ++ ++ ++ ++ 
copper ++ ++ ++ ++ ++ x 
stainless steel 
++ ++ ++ ++ ++ ++ 
SUS304 
nickel ++ ++ ++ ++ ++ ++ 
glass ++ ++ ++ ++ ++ ++ 
glass-epoxy ++ ++ ++ ++ + + x 
resin 
polybutylene 
++ ++ ++ ++ ++ x 
terephthalate 
nylon 6 ++ x ++ ++ x x 
polyphenylene 
x x + x x x 
sulfide 
______________________________________ 
EXAMPLE 5 
A curable organopolysiloxane composition in accordance with the present 
invention was prepared by mixing the following to homogeneity: 80 weight 
parts of dimethylvinylsiloxy-endblocked dimethylpolysiloxane with an 
average degree of polymerization of 300 and a vinyl group content of 0.24 
weight %; 20 weight parts of silicone resin composed of siloxane units 
with the formulas (CH.sub.3)SiO.sub.1/2 , (CH.sub.2 .dbd.CH) 
(CH.sub.3).sub.2 SiO.sub.1/2, and SiO.sub.4/2 (vinyl group content 
=approximately 2 weight %); a trimethylsiloxy-endblocked 
methylhydrogenpolysiloxane with an average degree of polymerization of 40 
and a silicon-bonded hydrogen content of 1.5 weight % (this component was 
added in sufficient quantity to give 1.5 moles silicon-bonded hydrogen per 
mole total alkenyl in the composition); 14.3 weight parts of fumed silica 
(specific surface =200 m.sup.2 /g) whose surface had been treated with 
hexamethyldisilazane; 2.3 weight parts of adhesion promoter (A); a rhodium 
chloride/di(n-butyl)sulfide complex in an amount sufficient to give a 
rhodium metal content in the composition of 10 ppm; and 0.02 weight parts 
of phenylbutynol. 
This curable organopolysiloxane composition was applied to copper plate at 
a coating thickness of 50 micrometers, and cured to give the silicone 
rubber by heating the coated plate for 1 hour at 150.degree. C. The 
adhesion was then evaluated by peeling the silicone rubber from the copper 
plate using a spatula. In addition, the silicone rubber bonded on the 
copper plate was immersed for 10 minutes in a 10% aqueous solution of 
hydrochloric acid at 50.degree. C., and the adhesion was evaluated 
following this immersion. The results are reported in Table 2. 
EXAMPLE 6 
A curable organopolysiloxane composition in accordance with the present 
invention was prepared by mixing the following to homogeneity: 80 weight 
parts of dimethylvinylsiloxy-endblocked dimethylpolysiloxane with an 
average degree of polymerization of 300 and a vinyl group content of 0.24 
weight %; 20 weight parts of silicone resin composed of siloxane units 
with the formulas (CH.sub.3).sub.3 SiO.sub.1/2, (CH.sub.2 
.dbd.CH)(CH.sub.3).sub.2 SiO.sub.1/2, and SiO.sub. (vinyl group 
content=approximately 2 weight %); a trimethylsiloxy-endblocked 
methylhydrogenpolysiloxane with an average degree of polymerization of 40 
and a silicon-bonded hydrogen content of 1.5 weight % (this component was 
added in sufficient quantity to give 1.5 moles silicon-bonded hydrogen per 
mole total alkenyl in the composition); 14.3 weight parts of fumed silica 
(specific surface=200 m.sup.2 /g) whose surface had been treated with 
hexamethyldi-silazane; 2.3 weight parts of adhesion promoter (B); a 
chloroplatinic acid/vinylsiloxane complex in an amount sufficient to give 
a platinum metal content in the composition of 10 ppm; and 0.02 weight 
parts of phenylbutynol. 
This curable organopolysiloxane composition was applied to copper plate at 
a coating thickness of 50 micrometers, and cured to give the silicone 
rubber by heating the coated plate for 1 hour at 150.degree. C. The 
adhesion was then evaluated by peeling the silicone rubber from the copper 
plate using a spatula. In addition, the silicone rubber bonded on the 
copper plate was immersed for 10 minutes in a 10% aqueous solution of 
hydrochloric acid at 50.degree. C., and the adhesion was evaluated 
following this immersion. The results are reported in Table 2. 
EXAMPLE 7 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 5, but in this case using adhesion promoter (C) in place of the 
adhesion promoter (A) used in Example 5. The adhesiveness was evaluated as 
in Example 5, and these results are reported in Table 2. 
EXAMPLE 8 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 6, but in this case using adhesion promoter (D) in place of the 
adhesion promoter (B) used in Example 6. The adhesiveness was evaluated as 
in Example 6, and these results are reported in Table 2. 
COMATIVE EXAMPLE 3 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 6, but in this case omitting the adhesion promoter (B) used in 
Example 6. The adhesiveness was evaluated as in Example 6, and these 
results are reported in Table 2. 
COMATIVE EXAMPLE 4 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 6, but in this case using tetramethoxysilane (TMS) in place of 
the adhesion promoter (B) used in Example 6. The adhesiveness was 
evaluated as in Example 6, and these results are reported in Table 2. 
COMATIVE EXAMPLE 5 
A curable organopolysiloxane composition was prepared using the procedure 
of Example 6, but in this case using bis(trimethoxysilyl)hexane (BTMSH) in 
place of the adhesion promoter (B) used in Example 6. The adhesiveness was 
evaluated as in Example 6, and these results are reported in Table 2. 
TABLE 2 
______________________________________ 
present invention comparative examples 
Ex. Ex. Ex. Ex. Comp. Comp. Comp. 
5 6 7 8 Ex. 3 Ex. 4 Ex. 5 
______________________________________ 
adhesion 
A B C D none TMS BTMSH 
promoter 
adhesion 
initial ++ ++ ++ ++ x ++ ++ 
after ++ ++ ++ ++ x x x 
treatment 
with 
hydro- 
chloric 
acid 
______________________________________