Method for preparation of organopentasiloxane

A process for the production of organopentasiloxane represented by the general formula: ##STR1## wherein R.sup.1 is an acryloyloxy-containing monovalent organic group or a methacryloyloxy-containing monovalent organic group; R.sup.3 is a monovalent hydrocarbon group; X is a hydrolytic group; and the subscript n is 0, 1, or 2; which is characterized subjecting (A) 1-hydroxy-organotetrasiloxane, or an organosiloxane oligomer mixture comprising it as the main component, which is obtained by hydrolyzing 1-acyloxy-organotetrasiloxane or an oganosiloxane oligomer mixture comprising it as the main component; and (B) hydrolytic silane represented by the general formula R.sup.3.sub.n SiX.sub.(4-n) to a condensation reaction.

FIELD OF THE INVENTION 
The present invention relates to a process for the production of 
organopentasiloxane, and, more specifically, it relates to a process for 
efficiently producing organopentasiloxane having an acryloyloxy-containing 
monovalent organic group or a methacryloyloxy-containing monovalent 
organic group bonded to a silicon atom at one end of the molecular chain 
and a hydrolytic group bonded to a silicon atom at the other end of the 
molecular chain. 
BACKGROUND OF THE INVENTION 
In the past, 3-acryloyloxypropyl trimethoxysilane, 
3-acryloyloxypropylmethyl dimethoxysilane, 3-methacryloyloxypropyl 
trimethoxysilane, 3-metacryloyloxypropylmethyl dimethoxysilane, and other 
organosilicon compounds with monovalent organic groups containing 
acryloyloxy groups or monovalent organic groups containing methacryloyloxy 
groups and hydrolytic groups bonded to silicon atoms have been used as 
silane coupling agents and raw materials for the production of 
crosslinkable polyolefinic resins. 
However, due to the fact that the monovalent organic groups containing 
acryloyloxy groups or monovalent organic groups containing methacryloyloxy 
groups and hydrolytic groups were bonded to the same silicon atoms, the 
problem with these organosilicon compounds was that when they were used as 
silane coupling agents for the surface treatment of inorganic fillers, 
these functional groups ended up concealed in the crosslinked coating 
formed via the condensation reaction and hydrolysis, so that the 
effectiveness of the surface treatment was lower than expected. For this 
reason, when inorganic fillers obtained by surface treatment using these 
organosilicon compounds were compounded with silicone rubber compositions, 
sufficient fatigue durability could not be imparted to the silicone 
rubbers obtained by curing them. Also, when these organosilicon compounds 
were copolymerized with various olefins as raw materials for the 
production of crosslinked polyolefinic resins, these functional groups 
ended up concealed in the polyolefinic resin, and, as a result, the 
crosslinkability of the polyolefinic resin was lower than expected. 
In the past, the authors of the present invention offered 
organopentasiloxanes with acryloyloxy-containing monovalent organic groups 
or methacryloyloxy-containing monovalent organic groups and hydrolytic 
groups bonded to silicon atoms and a process for their production (see 
Japanese Unexamined (Kokai) Patent Publication No. Hei 05(1993)-86075). 
The process for the production of the organopentasiloxane offered in 
Japanese Unexamined (Kokai) Patent Publication No. Hei 05(1993)-86075 was 
characterized by subjecting organopentasiloxane having a hydrogen atom 
bonded to a silicon atom at one end of the molecular chain and a 
hydrolytic group bonded to a silicon atom at the other end of the 
molecular chain and an alkene or alkylenoxyalkene containing 
methacryloyloxy groups to a hydrosilylation reaction. 
However, the problem with the process for the production of the 
organopentasiloxane offered in Japanese Unexamined (Kokai) Patent 
Publication No. Hei 05(1993)-86075 was that when it was used to produce 
organopentasiloxanes, various side reactions were generated. When, for 
example, 1,1,1 -trimethoxy-3,3,5,5,7,7,9,9-octamethylpentasiloxane and 
allyl methacrylate were subjected to a hydrosilylation reaction, a 
propene-releasing b-elimination reaction described below would take place, 
producing the target organopentasiloxane with a 3-methacryloyloxypropyl 
group bonded to a silicon atom at the end of the molecular chain along 
with organopentasiloxane with a methacryloyloxy group bonded to a silicon 
atom at the end of the molecular chain and organopentasiloxane with a 
propyl group bonded to a silicon atom at the end of the molecular chain as 
by-products, which decreased the yield and purity of the target product. 
##STR2## 
SUMMARY OF THE INVENTION 
It is an object of the present invention to offer a process for efficiently 
producing organopentasiloxane having an acryloyloxy-containing monovalent 
organic group or a methacryloyloxy-containing monovalent organic group 
bonded to a silicon atom at one end of the molecular chain and a 
hydrolytic group bonded to a silicon atom at the other end of the 
molecular chain. 
More specifically, the present invention relates to a process for the 
production of organopentasiloxane represented by the general formula (IV): 
##STR3## 
wherein R.sup.1,R.sup.3,X and the subscript n are as defined below, which 
is characterized by subjecting (A) a 1-hydroxy-organotetrasiloxane, or an 
organosiloxane oligomer mixture comprising it as the main component, 
represented by the general formula (II): 
##STR4## 
wherein R.sup.1 is as defined below, which is obtained by hydrolyzing 
1-acyloxy-organotetrasiloxane, or an organosiloxane oligomer mixture 
comprising it as the main component, represented by the general formula 
(I): 
##STR5## 
wherein R.sub.1 is an acryloyloxy-containing monovalent organic group or a 
methacryloyloxy-containing monovalent organic group, and R.sup.2 is a 
monovalent hydrocarbon group, and (B) a hydrolytic silane represented by 
the general formula (III): 
EQU R.sup.3.sub.n SiX.sub.(4-n) (III) 
wherein R.sup.3 is a monovalent hydrocarbon group, X is a hydrolytic group, 
and the subscript n is 0, 1, or 2, to a condensation reaction. 
DETAILED DESCRIPTION OF THE INVENTION 
Below, the production process of the present invention is explained in 
detail. 
In the production process of the present invention, first of all, 
1-hydroxy-organotetrasiloxane represented by the general formula (II), or 
an organosiloxane oligomer mixture comprising it as the main component, is 
prepared by hydrolyzing 1-acyloxy-organotetrasiloxane represented by the 
general formula (I) or an organosiloxane oligomer mixture comprising it as 
the main component. The organosiloxane oligomer mixture comprising 
1-acyloxy-organotetrasiloxane represented by the general formula (I) as 
the main component means a mixture of organosiloxane oligomers, in which 
an acyloxy group is bonded to a silicon atoms at the end of the molecular 
chain as represented by the general formula (I), but the number of 
siloxane units varies, and, preferably, it is a mixture containing not 
less than 50% of 1-acyloxy-organotetrasiloxane represented by the general 
formula (I). Also, in the same manner as above, the organosiloxane 
oligomer mixture comprising the 1-hydroxy-organotetrasiloxane represented 
by the general formula (II) means a mixture of organosiloxane oligomers, 
in which a hydroxyl group is bonded to a silicon atom at the end of the 
molecular chain as represented by the general formula (II), but the number 
of siloxane units varies, and, preferably, it is a mixture containing not 
less than 30% of 1-hydroxy-organotetrasiloxane represented by the general 
formula (II). R.sup.1 in the general formula (I) is an 
acryloyloxy-containing monovalent organic group or a 
methacryloyloxy-containing monovalent organic group specifically 
exemplified by 3-acryloyloxypropyl, 6-acryloyloxyhexyl, and other 
acryloyloxyalkyl groups; 3-(2-acryloyloxyethyloxy)-propyl and other 
acryloyloxyalkyloxyalkyl groups; 3-methacryloyloxypropyl, 
6-methacryloyloxyhexyl, and other methacryloyloxyalkyl groups; 
3-(2-methacryloyloxyethyloxy)-propyl and other 
methacryloyloxyalkyloxyalkyl groups. Preferably, it is an acryloyloxyalkyl 
or methacryloyloxyalkyl group, with 3-methacryloyloxypropyl being 
especially preferable from the standpoint of ease of manufacture and 
economic efficiency. Also, R.sup.2 in the general formula (I) is a 
monovalent group, specifically exemplified by methyl, ethyl, propyl, 
butyl, pentyl, and other alkyl groups; vinyl, allyl, butenyl, pentenyl, 
and other alkenyl groups; phenyl, tolyl, xylyl, and other allyl groups; 
benzyl, phenetyl, and other aralkyl groups, with methyl being especially 
preferable. 
A method, in which hexamethylcyclotrisiloxane is subjected to a 
ring-opening reaction with acyloxysilane represented by the general 
formula (V): 
##STR6## 
in the presence of an acidic catalyst, is suggested as the process for 
preparing 1-acyloxy-organotetrasiloxane represented by the general formula 
(I). R.sup.1 in the general formula (V) is an acryloyloxy-containing 
monovalent organic group or a methacryloyloxy-containing monovalent 
organic group exemplified by the same organic groups as above. Also, 
R.sup.2 in the general formula (V) is a monovalent hydrocarbon group 
exemplified by the same monovalent hydrocarbon groups as above. The acidic 
catalyst is exemplified by proton acid catalysts and Lewis acid catalysts, 
with proton acid catalysts specifically exemplified by hydrochloric acid, 
nitric acid, sulfuric acid, trifluoromethanesulfonic acid, trifluoracetic 
acid, among which trifluoromethanesulfonic acid is especially preferable, 
and with Lewis acid catalysts specifically exemplified by ZnCl.sub.2, 
BeCl.sub.2, TeCl.sub.4, SnCl.sub.4, FeCl.sub.3, FeCl.sub.2, SbCl.sub.5, 
AlCl.sub.3 and other metal halides. Because they suppress equilibration 
reactions due to siloxane bond rearrangement, selectively bring about the 
ring-opening reaction of the target hexamethylcyclotrisiloxane, and can 
suppress undesirable side reactions, metal halides exhibiting Lewis acid 
properties are preferable, with ZnCl.sub.2 being especially preferable. 
Also, the activity of the catalyst in the ring-opening reaction can be 
conspicuously increased by using acid halides or acid anhydrides together 
with the metal halides exhibiting Lewis acid properties. Catalysts 
composed of such metal halides exhibiting Lewis acid properties and acid 
halides or acid anhydrides are known as Friedel-Crafts acylation reaction 
catalysts. Such catalysts consist of a metal halide exhibiting Lewis acid 
properties and an acid halide or an acid anhydride. Although the mole 
ratio is arbitrary, 1 moL of acid halide and 0.5 moL of acid anhydride per 
1 moL of metal halide is preferable stoichiometrically. In practice, 
however, it is preferable to use them in equivalent or greater amounts. 
Also, it is preferable that the acyl groups in the acid halides or acid 
anhydrides used in the catalysts should be the same as the acyl group 
represented by the general formula: 
##STR7## 
in the acyloxysilane represented by the general formula indicated above. 
Next, 1 -hydroxy-organotetrasiloxane represented by the general formula 
(II) or an organosiloxane oligomer mixture comprising it as the main 
component is prepared by hydrolyzing 1-acyloxy-organotetrasiloxane 
represented by the general formula (I) or an organosiloxane oligomer 
mixture comprising it as the main component. When 
1-acyloxy-organotetrasiloxane represented by the general formula (I) is 
hydrolyzed, the reaction must be conducted carefully so as to suppress 
siloxane bond rearrangement and dimerization of the 
1-hydroxy-organosiloxane represented by the general formula (II), which is 
produced by hydrolysis. The hydrolysis can be conducted under milder 
conditions than in the case of hydrolyzing conventional 
1-halo-organotetrasiloxanes. When the 1-acyloxy-organotetrasiloxane 
represented by the general formula (I) is hydrolyzed, it is preferable to 
hydrolyze 1-acyloxy-organotetrasiloxane represented by the general formula 
(I) in the presence of an alkali metal or alkaline earth metal carbonate. 
Alkali metal carbonates are exemplified by sodium hydrogencarbonate, 
sodium carbonate, potassium carbonate, lithium carbonate, and the like, 
and alkaline earth metal carbonates are exemplified by magnesium 
carbonate, calcium carbonate, barium carbonate, and the like. The amount 
of addition of these alkali metal or alkaline earth metal carbonates is, 
preferably, between 0.5 and 1.5 moL per 1 moL of 
1-acyloxy-organotetrasiloxane represented by the general formula (I). 
Also, in order to promote hydrolysis, it is preferable to add 
triethylamine, pyridine, piperidine, quinoline, diethylhydroxyamine, and 
other amine compounds. The amount of addition of these amine compounds is, 
preferably, between 0.0001 and 1 moL per 1 moL of 
1-acyloxy-organotetrasiloxane represented by the general formula (I). 
Also, although the hydrolysis proceeds even in the absence of an organic 
solvent, it can be conducted in the presence of an organic solvent, such 
as toluene, xylene, and other aromatic hydrocarbons; diethyl ether, 
tetrahydrofuran, and other ethers; chloroform, carbon tetrachloride, 
methylene chloride, and other chlorinated hydrocarbons. Also, a 
temperature of -10.degree. C. to 100.degree. C. is preferable, and a 
temperature of 0.degree. C. to 50.degree. C. is especially preferable as 
the reaction temperature used for the hydrolysis. 
Next, organopentasiloxane represented by the general formula (IV) or an 
organosiloxane oligomer mixture comprising it as the main component is 
obtained by subjecting (A) 1-hydroxy-organotetrasiloxane, or an 
organosiloxane oligomer mixture comprising it as the main component, which 
is obtained by hydrolyzing 1-acyloxy-organotetrasiloxane or an 
organosiloxane oligomer mixture comprising it as the main component, and 
(B) hydrolytic silane represented by the general formula (III) to a 
condensation reaction. The organosiloxane oligomer mixture comprising 
organopentasiloxane represented by the general formula (IV) as the main 
component means a mixture of organosiloxane oligomers, in which a 
hydrolytic group is bonded to a silicon atom at the end of the molecular 
chain as represented by the general formula (IV), but the number of 
siloxane units varies. X in the general formula (III) is a hydrolytic 
group bonded to a silicon atom, and is specifically exemplified by 
methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy and other alkoxy 
groups; vinyloxy, allyloxy, butenyloxy, hexenyloxy, isopropenyloxy, and 
other alkenyloxy groups; phenyloxy, tolyloxy, xylyloxy, and other aryloxy 
groups; benzyloxy, phenetyloxy, and other arylalkoxy groups; acetoxy, 
propionyloxy, benzoyloxy, and other acyloxy groups; chlorine atoms, 
bromine atoms, iodine, and other halogen atoms, and, preferably, alkoxy or 
acyloxy groups. Also, the subscript n in the general formula (III) is 0, 
1, or 2. Preferably, the subscript n is 0. When the subscript n is 0, the 
organopentasiloxane represented by the general formula (IV) obtained by 
the condensation reaction is trifunctional, when the subscript n is 1, it 
is difunctional, and when the subscript n is 2, it is monofunctional. 
The condensation reaction is promoted by mixing and heating 
1-hydroxy-organotetrasiloxane represented by the general formula (II) or 
an organosiloxane oligomer mixture comprising it as the main component and 
a hydrolytic silane represented by the general formula (III). Also, 
condensation reaction catalysts can be added in order to promote the 
condensation reaction. Such condensation reaction catalysts are 
exemplified by acetic acid, propionic acid, acrylic acid, and other 
carboxylic acids; carbonic acid, hydrochloric acid, sulfuric acid, and 
other inorganic acids; sodium oxide, potassium hydroxide, lithium 
hydroxide, calcium hydroxide, magnesium hydroxide, and other inorganic 
bases; triethylamine, pyridine, piperidine, quinoline, 
diethylhydroxylamine, and other amines. Also, there are no particular 
limitations concerning the amount of addition of the hydrolytic silane 
represented by the general formula (III) relative to the 
1-hydroxy-organotetrasiloxane represented by the general formula (II) as 
long as there is an excessive molar amount of the hydrolytic silane. The 
temperature of the condensation reaction is, preferably, between 
70.degree. C. and 130.degree. C. This is due to the fact that when the 
reaction temperature is less than 70.degree. C., the condensation reaction 
does not proceed quickly, and when the temperature exceeds 130.degree. C., 
the siloxane bonds of the obtained organopentasiloxane become prone to 
rearrangement. As the occasion demands, the organopentasiloxane 
represented by the general formula (IV) can be efficiently prepared by 
fractional distillation of the organopentasiloxane represented by the 
general formula (IV), or an organosiloxane oligomer mixture comprising it 
as the main component, which is obtained by the condensation reaction of 
the hydrolytic silane represented by the general formula (III) and 
1-hydroxy-organotetrasiloxane represented by the general formula (II), or 
an organosiloxane oligomer mixture comprising it as the main component. 
When such fractional distillation is conducted, it is preferable to use 
oxygen, quinone compounds, amine compounds, hindered phenol compounds, 
phenothiazine, hindered phenols having an onium salt structure, and other 
polymerization inhibitors in order to prevent the reaction mixture from 
gelling. 
Because the organopentasiloxane represented by the general formula (IV) 
obtained in this manner has an acryloyloxy-containing monovalent organic 
group or a methacryloyloxy-containing monovalent organic group bonded to a 
silicon atom at one end of the molecular chain and a hydrolytic group 
bonded to a silicon atom at the other end of the molecular chain, it can 
be used as a coupling agent and as raw material for the production of 
crosslinkable polyolefinic resins, and reinforcing inorganic fillers 
surface-treated therewith can be imparted with a fatigue durability that 
is superior to that of silicone rubbers.

EXAMPLES 
The process for the production of organopentasiloxane of the present 
invention will be now explained by using application examples. 
Example 1 
25.8 g (314.3 mmoL) sodium acetate and 30 g toluene were placed in a 
four-neck flask furnished with an agitator and the system was subjected to 
azeotropic dehydration by heating it for 30 minutes at the reflux 
temperature of toluene. After that, the system was cooled to 75.degree. C. 
and 63 g (285.7 mmoL) 3-methacryloyloxypropyl dimethylchlorosilane was 
added dropwise. When the dropwise addition was over, the system was heated 
for 30 minutes at 80.degree. C. under agitation. When a portion of the 
reaction mixture was analyzed using gas chromatography ("GLC" below), the 
peak of 3-methacryloyloxypropyl dimethylchlorosilane had disappeared. 
After that, a toluene solution was obtained by filtering off the 
by-produced sodium chloride and unreacted sodium acetate. After removing 
toluene from a portion of this toluene solution, analysis using GLC, 
infrared spectroscopic analysis ("IR" below), .sup.1 H-nuclear magnetic 
resonance analysis (".sup.1 H--NMR" below) and gas chromatography-mass 
spectrometry ("GC--MS" below) showed that 3-methacryloyloxypropyl 
dimethylacetyloxysilane represented by the formula: 
##STR8## 
had been produced. 
Next, when 7.6 g (56.5 mmoL) acetic anhydride and 3.5 g (25.7 mmoL) zinc 
chloride were placed in a separate four-neck flask furnished with an 
agitator and subjected to heating under agitation for 10 minutes at 
70.degree. C., zinc chloride was completely dissolved and a dark red 
solution was obtained. After cooling the solution to room temperature, the 
entire amount of the previously prepared toluene solution of 
3-methacryloyloxypropyl dimethylacetyloxysilane, 63.4 g (285.7 mmoL) 
hexamethylcyclotrisiloxane, and 0.003 g 2,6-di-i-butyl-4-methylphenol were 
placed in the flask, and the system was heated at 50.degree. C. for 3 
hours 45 minutes under agitation. When a portion of the reaction mixture 
was analyzed using GLC, it was found that 3-methacryloyloxypropyl 
dimethylacetyloxysilane had been converted to 1-acetyloxy-7-(3 
-methacryloyloxypropyl)-1,1,3,3,5,5,7,7-octamethyltetrasiloxane 
represented by the formula: 
##STR9## 
The ratio (reaction ratio) was 88%. After that, the system was neutralized 
by adding 2.9 g (28.3 mmoL) triethylamine. A toluene solution was obtained 
by removing the by-produced salt by decantation. 119.3 g of a liquid was 
obtained from this toluene solution by heating the low boiling point 
fraction at 90.degree. C. for 1 hour under a reduced pressure of 1 mmHg. 
Analysis of a portion of this liquid using .sup.1 H--NMR, IR, and GC--MS 
showed that it consisted of an organosiloxane oligomer mixture comprising 
1-acetyloxy-7-(3-methacryloyloxypropyl)-1,1,3,3,5,5,7,7-octamethyltetrasil 
oxane as the main component, with the content of the siloxane determined by 
GLC being 65%. 
Subsequently, after adding the entire amount of the liquid, 30 g toluene, 
100 g water, 26.4 g (314.3 .mu.moL) sodium hydrogencarbonate and 1.59 g 
triethylamine (15.7 .mu.moL), the system was subjected to agitation for 
2.5 hours at room temperature. When a portion of the reaction mixture was 
analyzed by using GLC, the peak of 
1-acetyloxy-1-acetyloxy-7-(3-methacryloyloxypropyl)-1,1,3,3,5,5,7,7-octame 
thyltetrasiloxane had disappeared. After that, a toluene solution obtained 
by removing water from the system was washed twice. A liquid was obtained 
after removing toluene by heating the toluene solution in an evaporator 
under reduced pressure. Analysis of a portion of this liquid using GLC, 
IR, .sup.1 H--NMR, and GC--MS showed that it consisted of an 
organosiloxane oligomer mixture comprising 1 
-acetyloxy-1-acetyloxy-7-(3-methacryloyloxypropyl)-1,1,3,3,5,5,7,7-octamet 
hyltetrasiloxane represented by: 
##STR10## 
as the main component, the content of the siloxane determined by GLC being 
50%. 
Upon adding 47.8 g (314.3 .mu.moL) tetramethoxysilane and 0.15 g calcium 
hydroxide to the entire amount of the liquid, the system was subjected to 
heating under agitation for 10 minutes at the reflux temperature of 
tetramethoxysilane. After that, upon filtering off calcium hydroxide from 
the system and adding 0.12 g 
3,5-di-t-butyl-4-hydroxyphenylmethyldimethylammonium chloride, 0.012 g 
hydroquinone monomethyl ether, and 0.012 g 2,6-di-t-butyl-4-methylphenol, 
51.4 g (corresponds to a yield of 33%) of the 140.degree.-153.degree. C./1 
mmHg fraction was obtained by heating under reduced pressure. Analysis of 
the fraction using GLC, IR, and NMR showed that it consisted of an 
organosiloxane oligomer mixture, 85.3% of which was constituted by 
1,1,1-trimethoxy-9-(3-methacryloyloxypropyl)-3,3,5,5,7,7,9,9-octamethylpen 
tasiloxane represented by the formula: 
##STR11## 
Also, it was also found that this mixture did not contain 1,1,1 
-trimethoxy-9-methacryloxy-3,3,5,5,7,7,9,9-octamethylpentasiloxane 
represented by the formula: 
##STR12## 
and 1,1,1-trimethoxy-9-propyl-3,3,5,5,7,7,9,9-octamethylpentasiloxane 
represented by the formula: 
##STR13## 
Comparison Example 1 
16.6 g (131.4 .mu.moL) allyl methacrylate, 25 .mu.L hexane, and 0.01 g 
2,6-di-t-butyl-4-methylphenol were placed in a four-neck flask furnished 
with an agitator and subjected to azeotropic dehydration for 30 minutes. 
Next, after adding 1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex of 
platinum to the system in such a manner that the amount of platinum metal 
relative to allyl methacrylate was 20 ppm, 50 g (119.4 .mu.moL) of 
1,1,1-trimethoxy-3,3,5,5,7,7,9,9-octamethylpentasiloxane represented by 
the formula: 
##STR14## 
was added dropwise at 70.degree. C. When the dropwise addition was over, 
hexane was removed by elution from a portion of the reaction mixture, 
whereupon analysis using GLC, .sup.1 H--NMR, IR, and GC--MS showed that it 
consisted of an organopolysiloxane mixture, 62% of which was constituted 
by 1,1,1-trimethoxy-9-(3-methacryloyloxypropyl)-3,3,5,5,7,7,9-octamethylpe 
ntasiloxane represented by the formula: 
##STR15## 
and it was found that the mixture contained 34% 
1,1,1-trimethoxy-9-methacryloyloxy-3,3,5,5,7,7,9,9-octamethylpentasiloxane 
represented by the formula: 
##STR16## 
3% 1,1,1 -trimethoxy-9-propyl-3,3,5,5,7,7,9,9-octamethylpentasiloxane 
represented by the formula: 
##STR17## 
and 1% of other organosiloxane oligomers. 
Thus it has been shown that the process for the production of 
organopentasiloxane of the present invention is characterized by 
permitting efficient production of organopentasiloxane having an 
acryloyloxy-containing monovalent organic group or a 
methacryloyloxy-containing monovalent organic group bonded to a silicon 
atom at one end of the molecular chain and a hydrolytic group bonded to a 
silicon atom at the other end of the molecular chain.