A noncurable sealing material from a hydroxyl end-blocked polydiorganosiloxane, a filler and a silane or siloxane with two hydrolyzable groups having silicon-nitrogen bonds or silicon-oxygen-nitrogen bonds. The material when mixed and stored under substantially anhydrous conditions remains fluid but when exposed to the moisture in air increases in viscosity to form a sealing material which is uncured.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to noncurable sealing materials. 
2. Description of the Prior Art 
Sealing materials can be roughly divided into noncurable sealing materials 
and curable sealing materials. Both types are materials which are used for 
filling joints for the purpose of water-tightness and air-tightness, and 
are widely utilized in construction and engineering work, vehicles, 
automobiles and airplanes. Especially in the case of construction work, 
these sealing materials are widely used at joints between various parts, 
to seal windows to window frames and for joints and gaps produced by the 
occurrence of cracks. 
Noncurable glazier's putty and oily caulking materials are known as 
noncurable sealing materials. The former consists primarily of oils and 
fats and the latter also consists primarily of oils and fats, polybutene 
and alkyd resins. Thus, they have poor weather resistance. There is the 
drawback that the life of these sealing materials is short when they are 
used outdoors. There is also the drawback that they cannot be used at 
positions at high temperature because of their poor heat resistance. In 
addition, silicone oil sealing materials and sealing materials consisting 
primarily of nonreactive silicone oil and a filler have the drawback that 
separation of oil phase occurs easily. If a highly viscous silicone oil is 
used for decreasing the oil phase separation, the viscosity of the sealing 
material increases and there is the drawback that workability during the 
sealing process decreases. 
DESCRIPTION OF THE INVENTION 
The present invention provides a new material without the drawbacks of the 
above-mentioned known common noncurable sealing materials. 
This invention relates to a noncurable sealing material comprising a 
composition which increases in viscosity on contact with moisture, does 
not cure and substantially maintains its initial viscosity when stored in 
a container which does not substantially allow moisture to penetrate, 
consisting essentially of a product obtained by mixing the following 
ingredients under substantially anhydrous conditions 
(a) 100 parts by weight of a polydiorganosiloxane having 
silicon-atom-bonded hydroxyl groups at the terminus of the molecule 
chains, the organic groups of the polydiorganosiloxane being substituted 
or unsubstituted monovalent hydrocarbon radicals and said 
polydiorganosiloxane having a viscosity of 0.5 m.sup.2 /s or less at 
25.degree. C., 
(b) from 1 to 500 parts by weight of a filler and 
(c) an amount of an organosilicon compound sufficient to supply 
silicon-bonded nitrogen groups or groups having silicon-oxygen-nitrogen 
bonds in at least the same molar amount as the total molar amount of 
silicon-atom-bonded hydroxyl groups in (a), said organosilicon compound 
having two moisture hydrolyzable groups per molecule and said groups being 
selected from the group consisting of silicon-bonded nitrogen groups and 
groups having silicon-oxygen-nitrogen bonds. 
The components of this invention will be explained individually below. 
Component (a) is a polydiorganosiloxane of the following general formula 
having silicon atom-bound hydroxyl groups at the terminus of the molecular 
chain: 
##STR1## 
where R represents substituted or unsubstituted monovalent hydrocarbon 
radicals selected from among methyl, ethyl, propyl, octyl, phenyl, vinyl 
and trifluoropropyl groups, and m is a number such that the viscosity at 
25.degree. C. is 0.5 m.sup.2 /s or less. If the viscosity at 25.degree. C. 
exceeds 0.5 m.sup.2 /s, the workability when the composition is prepared 
by adding a filler, component (b) and a chain extension agent, component 
(c), and the workability and process when the composition is discharged 
from containers such as cartridges, tubes and plastic film containers, 
become very poor. In addition, if the viscosity is too low, the 
composition leaks out of the sealed container and the increase in 
viscosity is inadequate after filling a gap or cavity. The viscosity 
preferably ranges from 0.00005 to 0.05 m.sup.2 /s. 
The silicon-atom-bonded hydroxyl group at the terminus of the molecular 
chain is a functional group which is required for the condensation of 
component (a) with component (c) in the presence of moisture for obtaining 
higher molecular weight and higher viscosity. 
Component (a) can be a polymer of a single viscosity or a mixture of two or 
more viscosities. 
Component (b) of this invention is a filler which is used to modify the 
viscosity of component (a). For example, the following fillers can be 
used: dry-process silica (fumed silica), wet-process silica (precipitated 
silica), diatomaceous earth, fine quartz powder, talc, mica powder, 
calcium carbonate, magnesium carbonate, carbon black, asbestos powder and 
glass powder. 
The amount of component (b) ranges from 1 to 500 parts by weight per 100 
parts by weight of component (a). However, it is arbitrarily selected 
within the above-mentioned range according to the types of fillers used 
and in particular, the specific gravity and thickening ability, and 
according to the viscosity of organopolysiloxane. In the case of the 
fillers having a high thickening ability, i.e. dry-process silica, 
wet-process silica, carbon black, asbestos powder, non-surface-treated 
light and fine calcium carbonate, the amount used is relatively small, 
while in the case of the fillers having a relatively low thickening 
ability, i.e. diatomaceous earth, fine quartz powder, mica powder, 
surface-treated precipitated calcium carbonate and heavy calcium 
carbonate, the amount used is perferably higher. 
Component (b) can be a single filler or a mixture of two or more fillers. 
Component (c) is a component which helps increase molecular weight and 
viscosity by lengthening the polydioganosiloxane chain, component (a), 
when the sealing material of this invention is discharged into air from a 
sealed container. That is, component (c) is a bifunctional diorganosilane 
or bifunctional diorganosiloxane which is hydrolyzable with water. These 
compounds are generally expressed by the general formula: 
EQU R.sup.1 R.sup.2 SiX.sub.2 
where R.sup.1 and R.sup.2 are each an unsubstituted or substituted 
monovalent hydrocarbon radical and X is a hydrolyzable group selected from 
the group consisting of silicon-bonded nitrogen groups and groups having 
silicon-oxygen-nitrogen bonds, or the general formula: 
##STR2## 
where R, R.sup.1, R.sup.2 and X are defined above, and n has a value in 
the range of from 0 to 30 inclusive. In addition, the above-mentioned 
diorganosiloxane can contain a cyclic group. In these formulas, R, R.sup.1 
and R.sup.2 represent alkyl groups such as methyl, ethyl, and propyl, 
alkenyl groups such as vinyl, allyl and butadienyl, aryl groups such as 
phenyl, xylenyl and naphthyl, cycloalkyl groups such as cyclohexyl, 
cycloalkenyl such as cyclohexenyl, aralkyl groups such as benzyl, alkaryl 
groups such as tolyl and xylyl, and their substituted groups. R, R.sup.1 
and R.sup.2 can be selected from the same or different groups. 
X is a group which is hydrolyzable with water and which is bonded to a 
silicon atom. Examples of the hydrolyzable groups are amino groups 
##STR3## 
amido groups 
##STR4## 
imido groups 
##STR5## 
lactam groups 
##STR6## 
aminoxy groups 
##STR7## 
oxime groups 
##STR8## 
In these formulas, R.sup.3 through R.sup.12 each represent a hydrogen atom 
or unsubstituted or substituted monovalent hydrocarbon radical. Examples 
are the same as those described as examples of R, R.sup.1 and R.sup.2. In 
terms of ease of preparation of silanes and siloxanes having these 
functional groups, R.sup.3 through R.sup.12 are preferably selected from 
among unsubstituted and substituted monovalent hydrocarbon radicals. 
R.sup.13 and R.sup.14 represent alkylene groups. 
Examples of component (c) are as follows: aminosilanes and aminosiloxanes 
such as (CH.sub.3).sub.2 Si[NH(C.sub.4 H.sub.9)].sub.2, (CH.sub.3).sub.2 
Si[NH(C.sub.6 H.sub.5)].sub.2, (CH.sub.3).sub.2 Si[N(CH.sub.3).sub.2 
].sub.2, (CH.sub.3)(C.sub.6 H.sub.5)Si[N(CH.sub.3).sub.2 ].sub.2, 
(CH.sub.3)(CH.sub.2 .dbd.CH)Si[N(CH.sub.3).sub.2 ].sub.2, (CH.sub.3).sub.2 
Si[N(C.sub.2 H.sub.5).sub.2 ].sub.2, (CH.sub.3)(C.sub.6 
H.sub.5)Si[N(CH.sub.3)(C.sub.2 H.sub.5)].sub.2, (CH.sub.3)(C.sub.6 
H.sub.5)Si[N(CH.sub.3)(C.sub.2 H.sub.5)].sub.2, 
##STR9## 
aminoxysilanes and aminoxysiloxanes such as (CH.sub.3).sub.2 
Si[ON(CH.sub.3).sub.2 ].sub.2, (CH.sub.3)(C.sub.6 
H.sub.5)Si[ON(CH.sub.3).sub.2 ].sub.2, (CH.sub.3)(CH.sub.2 
.dbd.CH)Si[ON(CH.sub.3).sub.2 ].sub.2, (CH.sub.3).sub.2 
Si[ON(CH.sub.3)(C.sub.2 H.sub.5)].sub.2, (CH.sub.3)(CH.sub.2 
.dbd.CH)Si[ON(C.sub.2 H.sub.5).sub.2 ].sub.2, 
##STR10## 
or oximesilanes and oximesiloxanes such as (CH.sub.3).sub.2 
Si[ON.dbd.C(CH.sub.3).sub.2 ].sub.2, (CH.sub.3)(CH.sub.2 
.dbd.CH)Si[ON.dbd.C(CH.sub.3).sub.2 ].sub.2, (CH.sub.3).sub.2 
Si[ON.dbd.C(CH.sub.3)(C.sub.2 H.sub.5)].sub.2, (CH.sub.3)(C.sub.6 
H.sub.5)Si[ON.dbd.C(CH.sub.3)(C.sub.2 H.sub.5)].sub.2, 
##STR11## 
or amidosilanes and amidosiloxanes such as 
##STR12## 
or imidosilanes and imidosiloxanes such as 
##STR13## 
or lactamsilanes and lactamsiloxanes such as 
##STR14## 
Component (c) can be a single compound or a mixture of two or more 
compounds. However, when two or more types are used in a mixture, an X 
group which is hydrolyzable is preferably selected from the same type of 
group. The amount of organosilicon compound used is an amount sufficient 
to supply silicon-bonded nitrogen groups or groups having 
silicon-oxygen-nitrogen bonds in at least the same molar amount as the 
total molar amount (mol%) of silicon atom-bonded hydroxyl groups at the 
terminus of the molecular chain in component (a). 
By so doing, the composition of this invention can be preserved for a long 
period when prepared under substantially anhydrous conditions and when 
stored under substantially anhydrous conditions. When it is discharged 
into air, a highly viscous product is obtained and an extremely viscous 
form of putty can be produced. 
In addition to components (a), (b) and (c), a catalyst which accelerates 
the reaction between component (a) and component (c), i.e. diorganotin 
dicarboxylate, can be added. In addition, various additives which are 
generally compounded in the conventional silicone oil sealing materials, 
i.e. inorganic pigments, organic pigments, heat resistance agents, 
tackiness-improving agents, anti-sagging agents, and flame retardants, can 
be added. 
The composition of this invention can be produced as follows. For example, 
component (b) is added to component (a) and the mixture is blended in any 
of various types of blenders until a homogeneous mixture is obtained. 
After degassing, component (c) is added and the mixture is again blended 
until a homogeneous mixture is obtained. In this case, the moisture must 
be eliminated as much as possible from the mixture of component (a) and 
component (b), and component (c) must be added and blended under 
substantially anhydrous conditions. The obtained sealing material can be 
sucked up by a caulking gun and subsequently used in sealing work. 
Alternatively, the sealing material can be packed in a container which 
does not substantially allow moisture to permeate, e.g. cartridges, 
aluminum foil tubes and plastic film containers, and sealed for 
preservation. Thereafter, the stored sealing material can be used when 
needed. 
The sealing material of this invention has the following characteristics 
and effects: (1) If it is stored in a container which does not 
substantially allow moisture to permeate, the viscosity is unchanged after 
long-term storage; (2) since a polydiorganosiloxane having a low viscosity 
is used, it can be easily discharged from the container; (3) a gap or 
cavity can be easily filled; (4) the finishing work for the position 
filled is very easy; (5) the viscosity increases greatly in a time period 
of from one day to a few days after filling and an extremely viscous 
putty-like substance can be obtained; and (6) the obtained putty-like 
substance has excellent air-tightness and water-tightness, and no oil 
phase separation occurs after it is stored for a long period. This 
noncurable sealing material is especially useful as a sealing material for 
construction and civil engineering work.

The following examples are presented for illustrative purposes and should 
not be construed as limiting the scope of the invention which is 
delineated in the claims. "Parts" indicated in the following examples 
means "parts by weight". The viscosity was the value at 25.degree. C. The 
atmosphere for the sealing work was as follows: 23.degree.-25.degree. C. 
at 60-65% relative humidity. 
EXAMPLE 1 
Polydimethylsiloxane having hydroxyl terminal groups with a viscosity of 
0.015 m.sup.2 /s (100 parts) was well mixed with light, fine calcium 
carbonate without surface treatment (average particle size: 0.1.mu. and 
BET relative surface area: 7.5 m .sup.2 /g) (45 parts). After degassing, 
dimethyldi(N-methyl-acetamido)silane (8 parts) was added and the mixture 
was blended in a closed system without contact with moisture. The mixture 
obtained was packed in an aluminum tube. The material was squeezed out 
from the aluminum tube by hand and a vertical joint with a depth of 5 mm 
and a width of 8 mm, along a precast concrete plate, was filled with the 
contents of the aluminum tube. After 3 days, an extremely viscous putty 
had formed to a depth of 5 mm. After 6 months, no dripping had occurred 
nor was any separation of an oil phase observed. When this sealing 
material was stored in the aluminum tube at room temperature for 6 months, 
no changes occurred in its viscosity and it could still be squeezed out 
very easily by hand. 
EXAMPLE 2 
Polydimethylsiloxane having hydroxyl terminal groups with a viscosity of 
0.002 m.sup.2 /s (100 parts) was well mixed with dry-process silica whose 
surface had been treated with trimethylchlorosilane as a hydrophobic 
treatment and whose BET relative surface area was 130 m.sup.2 /g (20 
parts). After degassing, methylvinyldi(N,N-diethylaminoxy)silane (10 
parts) was added. The mixture was blended in a closed system without 
contact with moisture and the obtained mixture was packed in a paper 
cartridge whose interior surface was lined with aluminum foil. This paper 
cartridge was loaded in a hand gun. The content was squeezed out by hand 
and used to fill a horizontal groove between a plate of glass and an 
aluminum window sash (depth: 7 mm, width: 4 mm). After 5 days, an 
extremely viscous putty had formed to a depth of 7 mm. After 6 months, no 
separation of an oil phase was found. When this sealing material was 
stored in the paper cartridge for 6 months, no changes occurred in 
viscosity and the sealing material could still be easily squeezed out 
using a hand gun. 
EXAMPLE 3 
Dimethylsiloxane-methylphenylsiloxane copolymer having hydroxyl groups at 
the molecular chain terminus with a viscosity of 0.008 m.sup.2 /s (phenyl 
group content: 5 mol%) (100 parts) was well mixed with dry-process silica 
having a BET relative surface area of 200 m.sup.2 /g (10 parts). After 
degassing, methylphenyldi(N-cyclohexylamino)silane (11 parts) was added 
and the mixture was blended in a closed system without contact with 
moisture. The mixture was packed in a cylindrical container made of 
polyvinylidene chloride film and the container was wrapped with an 
evaporation-aluminized polyvinylidene chloride film. After 6 months, the 
external evaporation-aluminized polyvinylidene chloride film wrapper was 
taken off and the cylindrical container made of polyvinylidene chloride 
film was loaded in a hand gun. The material was squeezed out by hand and a 
horizontal groove between ALC panels (depth: 10 mm, width: 12 mm) was 
filled with the content. After 7 days, an extremely viscous putty was 
formed to a depth of 10 mm. After 6 months, no separation of an oil phase 
was found. 
EXAMPLE 4 
Sealing materials were prepared using the following compounds as component 
(c) as shown in the following table under the same conditions as in 
Example 1. The characteristics were evaluated and are shown in the 
following table. 
__________________________________________________________________________ 
Days required for 
forming an ex- 
Amount tremely viscous 
Separation of oil 
added putty to a depth 
phase after 6 
Component (c) 
(parts) 
Squeezability 
of 5 mm months 
__________________________________________________________________________ 
.alpha.,.omega.-Bis[dimethyl 
20 good 3 days none 
(N,N-diethylaminoxy)] 
dimethylsiloxane 
(degree of poly- 
merization: 10) 
Methylvinyldi 
10 good 5 days none 
(methylethylketo- 
xime)silane 
__________________________________________________________________________ 
EXAMPLE 5 
In the sealing material as in Example 1, colloidal calcium carbonate (120 
parts) (average particle size: 0.04.mu., BET relative surface area: 31 
m.sup.2 /g) with a treated surface was used instead of the light, fine 
calcium carbonate under the same conditions as in Example 1. The prepared 
sealing material was packed in an aluminum tube. The material was squeezed 
out from the aluminum tube and a horizontal groove between a plate of 
glass and an aluminum window sash (depth: 7 mm, width: 4 mm) was filled 
with this sealing material. After 5 days, an extremely viscous putty had 
formed to a depth of 7 mm. After 6 months, no separation of an oil phase 
had occurred. No changes occurred in its viscosity after leaving this 
sealing material in the aluminum tube at room temperature and the contents 
could still be squeezed out easily by hand.