JPH0146537B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a curable composition comprising a polyoxyalkylene polymer containing hydrolyzable silicone functional groups, which cures by absorbing atmospheric moisture. In particular, it relates to moisture-curable compositions that can be of one-component type. Blends of polyoxyalkylene polymers containing hydrolyzable silicone functional groups that can harden to rubber-like materials on exposure to moisture in the atmosphere have applications, for example, in architectural sealants. There are two-component sealants that mix the base agent and hardener immediately before use, and two-component sealants that mix the base agent and hardener in advance under anhydrous conditions, are stable in a sealed state, and harden by absorbing moisture when exposed to the atmosphere. There is a one-liquid type. 2
The liquid type is difficult to use, as it takes time to mix the base agent and curing agent, and the mixed material must be used up within a certain amount of time. It is much more convenient, as there is no need to use it, and leftovers can be used even after a while if they are sealed, but their storage stability is an issue. By adding a compound containing a hydrolyzable silicone group, the present invention can cure a one-component hydrolyzable silicone functional group-containing polyoxyalkylene polymer without special dehydration treatment of the raw material. This made it possible to obtain a sexual composition. According to the present invention, there is no need to dry the filler or the like beforehand as in the conventional method, and the advantage in manufacturing is clear. The hydrolyzable silicone compound used in the present invention undergoes a condensation reaction with the water originally contained in compounding agents such as fillers and plasticizers in the presence of a silanol condensation catalyst, and quickly removes the water in the system. lower. That is, the compound generally has a higher hydrolyzability than the terminal silicon functional group of the polyoxyalkylene polymer, and therefore acts as a dehydrating agent by first reacting with moisture in the system. In addition, the remaining small amount of the compound and its partially hydrolyzed product have the function of ensuring long-term storage stability of the composition. For the above reasons, the amount of the substituted or unsubstituted hydrolyzable silicon compound to be used is such that the total number of moles of the hydrolyzable functional groups of the compound is at least twice the number of moles of water in the system. However, if the amount is too large, the physical properties of the sealant after curing tend to decrease and the curing speed tends to be delayed, so the upper limit is naturally determined in consideration of the desired curing speed of the cured physical properties. In order to obtain normal properties, it is necessary to use an amount of 2.5 to 5 times the number of moles of water in the system, and it is possible to obtain a composition with good storage stability and properties during and after curing. I can do it. The hydrolyzable silicon compound used here is a low molecular weight silicon compound having a hydrolyzable functional group that reacts in the presence of moisture, and in the present invention, Si(OC ₂ H ₅ ) ₄ is used. be done. In the polyoxyalkylene polymer of the present invention, the main chain is essentially an -R ¹ -O- group (R ¹ is represented by an alkylene group having 1 to 4 carbon atoms) and at least one terminal thereof is hydrolyzed. Those containing possible silicone functional groups and having a molecular weight of 300 to 15,000 are preferred. Here, "essentially" indicates that the main chain may contain a bonding unit other than an alkylene group having 1 to 4 carbon atoms or a polymerized unit, but usually -R ¹ -
It is preferable that O-units account for 50% by weight or more, especially 80% by weight or more in the main chain. The terminal hydrolyzable silicone functional group is [In the formula, Z is -R-, -R-OR-,

【formula】

[Formula] and

[Formula] (R is the same or different divalent hydrocarbon group having 1 to 20 carbon atoms), R ² is hydrogen or the same or different carbon number 1
~20 substituted or unsubstituted monovalent organic groups or triorganosiloxy groups, R ³ is substituted or unsubstituted monovalent organic groups or organosiloxy groups having 1 to 20 carbon atoms, R ⁴ is 1 to 20 carbon atoms 20 saturated monovalent hydrocarbon groups, a is an integer of 0 or 1, b is an integer of 0, 1 or 2, c is an integer of 0, 1 or 2, m is 0 to 18
is a silicone functional group represented by an integer of . Methods for producing polyoxyalkylene polymers having such terminal groups are described, for example, in JP-A-50-156599 and JP-A-156599.
55-123620. A silanol condensation catalyst, a filler, a plasticizer, etc. can be added to the composition of the present invention. The silanol condensation catalyst used in the composition of the present invention includes metal organic carboxylates such as tin octylate, tin stearate, iron naphthenate, lead octylate, di-n-butyltin-di-laurate, di- Tetravalent organic tin such as n-butyltin-di-phthalate, amines such as laurylamine and ethanolamine, alkyl titanates, and the like can be used alone or in combination. In the present invention, the curing catalyst not only acts as a catalyst for the crosslinking reaction of the polyoxyalkylene polymer, but also promotes the reaction between a hydrolyzable silicon group-containing compound and water in the pre-crosslinking reaction stage, and It also plays the role of removing moisture from things. The amount of silanol condensation catalyst added is
Per 100 parts by weight of polyoxyalkylene polymer
0.1 to 10 parts by weight is preferred. Fillers that can be used in the present invention include calcium carbonate,
Common materials include kaolin, talc, titanium oxide, aluminum silicate, and carbon black.
The amount is usually in the range of 0.1 to 300 parts by weight per 100 parts by weight of the polyoxyalkylene polymer. Plasticizer is DOP
(dioctyl phthalate), BBP (butyl benzyl phthalate), chlorinated paraffin, epoxidized soybean oil, and other conventional substances range from 0 to 200 parts by weight per 100 parts by weight of the polyoxyalkylene polymer. These fillers and plasticizers can be used without any problem at their commercially available moisture contents. If the moisture content can be reduced by simple pretreatment, it is of course possible to use a product that has had some moisture removed by heat drying, pretreatment, etc. In this case, the amount of substituted or unsubstituted hydrolyzable silicon compound added can be reduced, which is advantageous in terms of cost. In addition, the composition of the present invention may contain various additives. For example, suitable anti-sagging agents include hydrogenated castor oil, silicic anhydride, or organic bentonite, and anti-aging agents include various substances classified as ultraviolet absorbers, radical chain inhibitors, peroxide decomposers, etc. alone or Can be used in combination. In order to adjust the physical properties of the composition of the present invention, a reactive silicon compound disclosed in JP-A-53-129247, a polysiloxane as disclosed in JP-A-55-21453,
It may also contain an ultraviolet curable resin disclosed in JP-A-55-36241. The present invention will be explained below with reference to Examples. Example 1 80% of all ends

[Formula] For 100 parts by weight of an oxypropylene polymer with an average molecular weight of 8000 having a group, 34 parts by weight of DOP, 140 parts by weight of calcium carbonate, 20 parts by weight of titanium oxide, 4 parts by weight of hydrogenated castor oil as an anti-sagging agent, and anti-aging agent. As agents, Nokrac NS-6 [2,2'-methylene-bis(4-methyl-6-t-butyl-phenol)], Sanol LS
-770 [bis(2,2,6,6-tetramethyl-4
-piperidine) sebacate] were added and uniformly kneaded using a sealed mixer. All of these raw materials were commercially available products and were used as they were in a moist state. After kneading, measure the moisture content
It was 2000ppm. After adding 6.9 parts by weight (the number of hydrolyzable functional groups is 3.8 times the number of moles of water) of tetraethylorthosilicate and uniformly dispersing it with a mixer, 1 part of di-n-butyltin-dilaurate was added. and stirred for 1 hour. Take this out and place it in an airtight container so that it does not come into contact with the outside air.
When stored at ℃, it was stable for more than 1 month.
Further, when this material was exposed to the outside air, it was cured in 6 hours. In addition, H-shaped test pieces were prepared according to JIS-A5758.
After curing at 23°C and 60% humidity for 14 days and a further 14 days at 30°C, a tensile test was conducted at a speed of 50 mm/min.
The results are 50% modulus 3.7Kg/cm ² and strength at break 7.0
Kg/cm ² and elongation was 230%. Tetraethylorthosilicate is cheap;
Since it is highly reactive with water, it has a large storage stabilizing effect, is non-corrosive, has the advantages of improved adhesion to construction objects, and improved water resistance of the cured product. Reference example 1 80% of all ends

[Formula] For 100 parts by weight of an oxypropylene polymer with an average molecular weight of 8000 having a group, 34 parts by weight of DOP, 140 parts by weight of calcium carbonate, 20 parts by weight of titanium oxide, 4 parts by weight of hydrogenated castor oil as an anti-sagging agent, and anti-aging agent. Add 1 part each of Nokrac NS-6 and Sanol LS-770 as agents,
Knead in a sealed mixer until homogeneous. All of these raw materials were commercially available products and were used as they were. After kneading, the moisture content was measured and found to be 2500 ppm. To this, 8.6 parts by weight (number of hydrolyzable functional groups equal to 2.6 times the number of moles of water) γ-glycidoxypropyltrimethoxysilane was added, and after uniformly dispersing with a mixer, di-n-butyl Two parts by weight of an equimolar solution of tin oxide in DOP was added and stirred for 1 hour. When this product was stored at 50°C under moisture exclusion, it remained stable for more than one month. When this was exposed to the outside air, it was cured in one hour. In addition, as a result of testing on the H-type test piece in the same manner as in Example 1, the 50% modulus was 3.3Kg/
cm ² , strength at break was 6.5 Kg/cm ² , and elongation was 470%. Reference example 2 80% of all ends

[Formula] For 100 parts by weight of an oxypropylene polymer with an average molecular weight of 8000, 34 parts by weight of DOP, 140 parts by weight of calcium carbonate, 20 parts by weight of titanium oxide, 4 parts by weight of hydrogenated castor oil as an anti-sagging agent, and anti-aging agent. Add 1 part each of Nokrac NS-6 and Sanol LS-770 as agents, and knead with a sealed mixer until uniform. These raw materials were commercially available products and were used as they were. After kneading, the moisture content was measured and found to be 2000 ppm. Here, 5.0 parts by weight (the number of hydrolyzable functional groups is 4.0 times the number of moles of water) of vinyltri(isopropenyloxy)silane.

After adding [formula] and uniformly dispersing it with a mixer, di-n-butyltin-
1 part of dilaurate was added and stirred for 1 hour. When this product was taken out and stored in a sealed container at 50°C without being exposed to the outside air, it remained stable for over a month. Furthermore, when this product was exposed to the outside air, it became tack-free in 3 hours. In addition, as in Example 1, the H-type test piece was tested, and as a result, 50
% modulus 4.1Kg/cm ² , strength at break 6.7Kg/cm ² ,
The growth was 420%. Comparative Example 1 A composition obtained by performing all the same operations as in Example 1 except that tetraethyl orthosilicate was not added was stored at 50°C in a closed container, but 3
After a few days, it had completely gelled. Comparative Example 2 A composition obtained by performing all the same operations as in Example 1 except that the amount of tetraethylorthosilicate used was 3.1 parts by weight (the number of hydrolyzable functional groups was 1.7 times the amount of water) was placed in a closed container. It was stored at 50°C, but after one week it had thickened and was unusable. Reference Example 3 In Reference Example 1, the amount of γ-glycidoxypropyltrimethoxysilane used was 4.5 parts by weight (the number of hydrolyzable functional groups is 1.5 times the number of moles of water).
A composition obtained by carrying out all the same operations except that the composition was stored at 50° C. in a closed container, but after one week it had thickened and was unusable. Comparative Example 3 Instead of the oxypropylene polymer of Example 1,
The same procedure as Example 1 was used except that an oxypropylene polymer having an average molecular weight of 8000 and having a methyldiisopropenyloxysilyl group, (CH ₃ )(CH ₂ =C(CH ₃ )O) ₂ Si-, at the end of the molecular chain was used. Compositions were prepared under similar conditions. Despite the addition of the silicon compound of the present invention, this composition gelled after one month even when stored in a closed container.

Claims (1)

[Claims] Linear formula [In the formula, Z is -R-, -R-O-R-, [Formula] and [Formula] (R is the same or different divalent hydrocarbon group having 1 to 20 carbon atoms), R ² is hydrogen or same or different carbon number 1
~20 substituted or unsubstituted monovalent organic groups or triorganosiloxy groups, R ³ is substituted or unsubstituted monovalent organic groups or organosiloxy groups having 1 to 20 carbon atoms, R ⁴ is 1 to 20 carbon atoms 20 saturated monovalent hydrocarbon groups, a is an integer of 0 or 1, b is an integer of 0, 1 or 2, c is an integer of 0, 1 or 2, m is 0 to 18
In a curable composition containing a polyoxyalkylene polymer having a silicon functional group represented by
(OC ₂ H ₅ ) ₄ is added and the amount added is
The total number of moles of hydrolyzable functional groups in the silicone compound is 2.5 to 5 times the number of moles of water in the composition, and is stable in a sealed state and can be cured by exposure to moisture. Room temperature curable composition.