JPS6043867B2 - Room temperature curable polyorganosiloxane composition - Google Patents

Description

Detailed Description of the Invention The present invention provides rubber-like elasticity by crosslinking α・ω-dihydroxypoly(diorganosiloxane) with an organosilicon compound having an average of two or more aminoxy groups in one molecule. The improved room-temperature curable polyorganosiloxane composition that provides a polyorganosiloxane composition that is liquid or plastic when stored in a dry environment and hardens upon contact with moisture. 1'I-j-ιl■I-Fi ゛i4CM-ト ←l, L 噌, ι■1, 1 body' relates to a room temperature curable polyorganosiloxane composition.

Recently, room-temperature curing polyorganosiloxane elastomer (referred to as RTV silicone rubber) has been used as a sealing material for buildings due to its excellent characteristics: excellent weather resistance, durability, heat resistance, and cold resistance. It is widely used because its physical properties change little with temperature and it is less susceptible to deterioration due to ozone, ultraviolet rays, etc.

Traditionally, acetic acid-depleted polyorganosiloxane elastomers have been mainly used for this purpose, but they do not provide sufficient adhesion to concrete or mortar even after being primed, and they are often released. There are drawbacks such as corrosion caused by acid, and a solution to these drawbacks has been desired. These difficulties can be solved with polyorganosiloxane elastomers such as de-oxime type and dealcohol type, but when these elastomers are used as sealants, the modulus is large and the elongation at break is limited to about 600%. It was unsatisfactory as a sealing material for high-rise buildings. In other words, these high-rise buildings require sealing materials with low modulus and high elongation at break due to the need to absorb vibrations caused by earthquakes, etc. The properties of organosiloxane elastomers do not satisfy these requirements, and therefore there are restrictions on the locations in which they can be used. As a polyorganosiloxane sealing material with low modulus and high elongation, a dehydroxyamine based on a combination of α◆ω-dihydroxy poly(diorganosiloxane) and an aminoxy group-containing silicon compound proposed in Japanese Patent Publication No. 43-24545. type polyorganosiloxane elastomer.

This has the advantage that a sealing material with low modulus and high elongation can be obtained by adjusting the ratio of the difunctional aminoxy group-containing silicon compound to the trifunctional aminoxy group-containing silicon compound. However, at present, the sealing failure due to this crosslinking mechanism is a two-pack type in which α●ω-dihydroxypoly(diorganosiloxane) and aminoxy group-containing silicon compound are stored separately, and when used, they are mixed and cured at room temperature. However, it is difficult to mix uniformly at construction sites under various adverse conditions, and it is necessary to prevent measurement errors and insufficient mixing in order to mix certain amounts of both components. There is. Therefore, in the case of acetic acid-removed type, oxime-removed type, and alcohol-eliminated type, α・ω-dihydroxypoly(diorganosiloxane) and crosslinking agent are stored in the same container with no moisture and released into the air. It was hoped that a so-called one-pack type product would be developed, in which the product would be cured by moisture, but if conventional technology were used,
When α・ω-dihydroxypoly(diorganosiloxane) and an aminoxy group-containing silicon compound are mixed, a dehydroxyamine reaction and a siloxane cleavage reaction occur, and even if stored in a dry state, it will take 2 to 3 hours. However, the curing progressed or, conversely, the curing did not reach the desired hardness even when exposed to moisture in the air, and it was not possible to make it into a one-pack type. The present inventors have discovered that the instability of a system containing an α・ω-dihydroxypoly(diorganosiloxane) and an aminoxy group-containing silicon compound is caused by the reaction of a part of the two in the coexistence of the organosiloxane. It was discovered that by acting as a catalyst for the dehydroxylamine reaction, hydroxylamine promotes both of the above reactions even in the absence of moisture, and that this is due to the scission of the siloxane chain. By promptly removing the above from the system, we succeeded in significantly increasing the stability of both in a moisture-free state.

Furthermore, depending on the selection of the type and amount of additives that react with the organohydroxylamine and remove it from the system, it may be possible to impair the curing reaction in the presence of moisture, and the composition as a sealant. The inventors have discovered that this does not impair the properties of the compound, and have completed the present invention. That is, the present invention provides (4) general formula HOCR″2S10]NH(TAS
tR'' are mutually the same or different monovalent substituted or unsubstituted hydrocarbon groups, n is a number satisfying the following viscosity range), and the viscosity at 25°C is 20 to 1,000,000.
11) 1 (4) parts by weight of α・ω-dihydroxypoly(diorganosiloxane), which is P, (B) an average of 2 parts by weight in the molecule
1 to 3 parts by volume of an aminoxy group-containing silicon compound having at least 1 organoaminoxy group, and (C) 0.01 part of an organosilicon compound having a hydrogen atom bonded to a silicon atom.
to a room temperature curable polyorganosiloxane composition consisting essentially of parts by weight of W.

The α・ω-dihydroxypoly(diorganosiloxane) used in the present invention (4) has the general formula HO[R″2Si
0]NH (S-R'', n is as described above) and has a viscosity of 20 to 1,000,000 CP at 25°C.

R″ is a monovalent hydrocarbon group such as methyl group, ethyl group, propyl group, butyl group, vinyl group, phenyl group, chloromethyl group, cyanoethyl group, 3●3◆3-trifluoropropyl A monovalent substituted hydrocarbon group such as a group is exemplified, and they may be the same or different from each other. Characteristics as a sealant, especially low modulus, excellent weather resistance, and moderate curing speed.
In order to satisfy that the composition has appropriate fluidity before curing, it is preferable that 85% or more of R'' is a methyl group, and in particular, when all R'' are methyl groups, these characteristics, This is advantageous from the viewpoint of ease of synthesis of α・ω-dihydroxypoly(diorganosiloxane). In addition, when cold resistance or heat resistance is required, it is recommended to use a phenyl group as a part of R''.The range of n is determined by ease of handling, flowability of the composition, Due to the physical properties of the sealant, α・ω-dihydroxypoly(
The viscosity of diorganosiloxane) is 20~20 at 25℃
It is chosen to be between 1,000,000 CP. The value of n varies depending on the type of R'' and its molar ratio, but
R″ corresponds to 20 to 3000 when all are methyl groups.Among them, the viscosity at 25°C is 100 to 1000.
It is preferably between 0 .P and more preferably between 500 and 50,000:)P. This is because if a sealant with a viscosity of less than 2CCP is used, it will not be possible to obtain a low modulus and good elongation at break as a sealant;
This is because if a material exceeding the CP is used, workability will deteriorate. The aminoxy group-containing silicon compound (B) used in the present invention is produced by performing a dehydroxylamine reaction with the terminal silanol group of α・ω-dihydroxypoly(diorganoxy). It performs crosslinking and chain length extension, and may be a silane derivative or a linear, cyclic or branched siloxane derivative.

In particular, for the purpose of obtaining a sealing material with good reactivity, low modulus, and high elongation, combinations of cyclic polysiloxanes having two and three aminoxy groups in one molecule are preferred. The organic groups to be bonded to the aminoxy group include two monovalent hydrocarbons such as methyl, ethyl, propyl, butyl, and cyclohexyl groups, or two monovalent carbons such as butylene and pentene groups. One hydrogen group is exemplified, but availability of raw materials, ease of synthesis, reactivity,
In view of the ease with which the organohydroxylamine to be released can be volatilized, an ethylene group is preferable. Examples of such aminoxy group-containing silicon compounds include the following. Hereinafter, for the sake of simplicity, the following abbreviations will be used for various organosilicon compounds. Me: methyl group,
Et: ethyl group, Bu: butyl group, Vi: vinyl group, P
h: Phenyl potato. ---. [0Me2S10NE
t2]3, PhSl[0Me2Si0NEt2]3 The amount of the aminoxy group-containing silicon compound is 1 to 3 parts by weight, preferably 3 to 2 parts by weight, based on 100 parts by weight of the α・ω-dihydroxypoly(organosiloxane) (4). Selected from the range of traffic volume. The amount of aminooxy group-containing silicon compound is 1
If it is less than 3 parts by weight, the reaction rate with the α・ω-dihydroxypoly(organosiloxane) will be too fast and one package will be damaged, and if it exceeds 3 parts by weight, storage stability will deteriorate and curing properties will decrease. It is. Used in the present invention (
The organosilicon compound of C) reacts with the organohydroxylamine generated by a partial reaction when the above components (4) and (B) are mixed, and removes it from the system, thereby reducing moisture. It is an additive for imparting stability to a mixed system of both components in the absence of moisture.Moreover, in the presence of moisture, a large amount of is consumed by organohydroxylamines generated in
Does not inhibit curing reaction.

) Examples of organosilicon compounds having a hydrogen atom bonded to a silicon atom (C) used in the present invention include Et
3SiHNMe3SiSiMe2H,. HMe2SiO
SiMe2HlMe3SiOMeHSiOSiMe3,
Me3SiO[MeHSlO]2SiMe3,M
e3SiOCMeHSiO]PSiMe3 (p is a number from 3 to 60), Me3SiOCMeHSiO]9[M
e2SiO') QSiMe3 (Stp is as described above, q is a number from 1 to 40).

The reaction of these organosilicon compounds with organohydroxylamine (diethylhydroxylamine is shown as an example) is shown in the following formula (1). …SlH+Et2NO
H→...SlONEt2+H2 (1) The amount of such an organosilicon compound added is 0.00 parts by weight per 100 parts by weight of the α●ω-dihydroxypoly(diorganosiloxane) in (4).
0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight. If it is less than 0.01 part by weight, the composition will not have sufficient storage stability, and if it exceeds 1 part by weight, the above (
1) Hydrogen gas generated as the formula progresses causes foaming, internal pressure is applied to the container, and curing is delayed in the presence of moisture.

In the present invention, a finely powdered inorganic filler may be added in order to impart appropriate flowability to the composition before curing and to impart mechanical properties necessary as a sealant to the composition after curing. preferable.

Examples of inorganic fillers include reinforcements such as fumed silica, pyrogenic silica, precipitated silica, fumed titanium, and their surfaces hydrophobized with organochlorosilanes, polyorganosyl, xane, and hexamethyldisilazane. Examples include non-reinforcing fillers such as carbonate fillers, calcium carbonate, organic acid surface treated calcium carbonate, diatomaceous earth, ground silica, aluminosilicate, magnesia, alumina, and the like. As a building sealant, it is preferable to use a non-reinforcing filler, especially when a low modulus is required. The inorganic filler is selected from 50 parts by weight or less, preferably 1 part by weight, per 10 parts by weight of the α・ω-dihydroxypoly(diorganosiloxane).
The range is 30 parts by weight, more preferably 40 to 15 parts by weight. If the amount of inorganic filler is less than this, sufficient mechanical properties cannot be obtained, and if it is too much, the modulus becomes large and the elongation at break becomes low. There is no harm in adding coloring pigments, fungicides, flame retardants, etc. to the composition of the present invention, if necessary. 7 The composition of the present invention maintains the characteristics of a dehydroxylated polyorganosiloxane composition, such as low modulus and high elongation, which are necessary properties for sealing materials for high-rise buildings, while maintaining long-term durability in the absence of moisture. This made it possible for the first time to store it and use it as a single-pack sealing material.

This eliminates the need for mixing during construction at a construction site, eliminates construction defects caused by mixing errors such as measurement errors and insufficient mixing, and has the advantage of shortening construction time. The composition of the present invention is useful as a low modulus one-pack sealant in architecture, particularly in high-rise buildings.

The present invention will be explained below with reference to Examples.

In the examples, all parts represent parts by weight. In addition, “Example”
The following abbreviations are used to describe the physical properties.
H: Hardness' TS: Tensile strength E: Elongation M5O: 50% Modulus CF: Cohesive failure rate Example 1 100 parts of α・ω-dihydroxypoly(dimethylsiloxane) having a viscosity of 80,000 CP at 25°C and calcium carbonate powder 1 ( Knead part) and make base compound A.
I got it.

Comparative example sample 1a was obtained by kneading 2.7 parts and 0.3 parts with this base compound A1 (1) part, and ← M
A composition sample 1b was obtained by kneading 30.05 parts of e3SlO[MeHSlO]2SiMe.

These samples were packed and sealed in aluminum tubes in the absence of moisture and stored initially and at room temperature for 3 months and 6 months, respectively, and then extruded into air to a thickness of 2Tn! Form into a sheet of n, temperature 25℃, humidity 50℃.
%RH for 7 days to completely cure. When the physical properties of this product were measured, the results shown in Table 1 were obtained. Example 2 In the base compound AlOO part prepared in Example 1,
In the same manner as in Example 1, a comparative sample 1a to which 2.25 parts and 0.25 parts were added, and a composition sample 1b to which 0.1 part was further added were obtained.

These samples were packed in an aluminum tube in the absence of moisture, sealed, and stored in a thermostatic oven at 50°C for 7 to 27 days. When the physical properties of the compound were measured, the results shown in Table 2 were obtained. Example 3 In the base compound AlOO part prepared in Example 1,
Comparative sample C obtained by adding a mixture of 0.8 parts and 0.01 parts and mixing thoroughly was packed in an aluminum tube in the absence of moisture and sealed, but the apparent viscosity increased within the tube. After 2 hours, it became impossible to extrude it from the tube, and after 3 hours it turned into a gel.

On the other hand, Me3S was added to the above aminoxysiloxane mixture.
iO[MeHSlO]30CMe2S10]20S1M
A composition sample obtained by adding 30.05 parts of e in advance and thoroughly mixing it was packed in an aluminum tube in the same way, and it was found that it had the same good extrudability as the initial one even after being stored for 3 months. Obtained. Composition sample? Table 3 shows the physical properties of a sheet with a thickness of 2 wrm obtained in the same manner as in Example 1. Example 4 100 parts of α-ω-dihydroxypoly(diorganosiloxane) having a viscosity of 30,000 CP at 25°C and consisting of 8 mol% diphenylsiloxy units and 92 mol% dimethylsiloxy units and 10 (2 )
were kneaded to obtain a base compound.

Add 100 parts of this base compound to Et2NOMe2S.
lOPh2SlOSlMe2ONEt22.75 parts, M
e3SlOCMeHSlO]20S1Me30. The mixture was added to the mixture and kneaded under sealed conditions at room temperature to obtain a composition sample.

This was packed in an aluminum tube in a moisture-free state, sealed, and initially stored at room temperature for 6 months, then extruded into the air to make a sheet with a thickness of 2 Twt in the same manner as in Example 1. When the physical properties were measured, the results shown in Table 4 were obtained. Example 5 Base compound B was obtained by kneading 1 (4) parts of calcium carbonate powder and 50 parts of alumina powder with 100 parts of α·ω-dihydroxypoly(dimethylsiloxane) having a viscosity of 20,000 CP at 25°C.

This base compound
Et2NOMe2SiOSjMe2 in BlOO part
ONEt22. α? , 40.1 parts of [MeHSiO] were added thereto, and the mixture was kneaded at a temperature of 70° C. for 6 hours under closed conditions to obtain a composition. This is sealed in a moisture-free condition and the temperature is 50℃.
After storing it for 3 weeks, it was extruded into the shape shown in FIG. 1 and adhered between aluminum, glass or mortar, and left in the air at room temperature for 3 weeks to harden to obtain a test specimen. When this material was subjected to a tensile test at a speed of 50 TI0 nImin, the results shown in Table 5 were obtained. Example 6 A sixth compound was added to the base compound AlOO obtained in Example 1.
Various aminoxy group-containing silicon compounds and additives shown in the table are added and kneaded, placed in an aluminum container in the absence of moisture, sealed tightly, and extruded into the air after 4 months.
The physical properties of a sheet having a thickness of 2 THm were measured in the same manner as in Example 1, and the results are shown in Table 6.

Example 7 An α.
ω-dihydroxy poly(diorganosiloxane) 100
A base compound was obtained by kneading the powder, crushed quartz powder, and calcium carbonate powder.

To 1 (4) parts of this base compound, [Me2SlO
] 20.6 parts of 12Si11Me were added and mixed, stored in an aluminum container for 3 months in a moisture-free state, and bonded between glass plates in the shape shown in Figure 1. Good adhesion was observed. showed his sexuality.

[Brief explanation of the drawing]

Figure 1 shows a specimen for an adhesive tensile test of a silicone sealant.

Claims (1)

[Claims] 1 (A) General formula HO[R'_2SiO]nH (where R' is the same or different monovalent substituted or unsubstituted hydrocarbon group, and n satisfies the following viscosity range) viscosity at 25°C is 20 to 1,000,000c
100 parts by weight of α・ω-dihydroxypoly(diorganosiloxane) which is P, (B) 1 to 30 parts by weight of an aminoxy group-containing silicon compound having an average of 2 or more organoaminoxy groups in the molecule, and (C) A room temperature curable polyorganosiloxane composition consisting essentially of 0.01 to 10 parts by weight of an organosilicon compound having hydrogen atoms bonded to silicon atoms. 2. The composition according to claim 1, wherein R' in (A) is a methyl group.