JPS582342A - Composition curable at room temperature - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent long-term storage stability, free from discoloration, color developnt and odor, and usable also as a one-pack type composition, by removing the water from a mixture of a polymer having hydrolyzable silicon group at the terminal and containing a main chain composed of polyether by azeotropic dehydration. CONSTITUTION:Water in the mixture mainly of a polyether containing at least one hydrolyzable silicon group and having a main chain composed essentially of the recurring unit of formula -R<1>-O- (R<1> is bivalent alkylene) is removed by the azeotropic dehydration using a volatile organic compound. The hydrolyzable silicon group is silyl group or silyloxysilyl group bonded with alkoxy group, alkenyloxy group, etc. The volatile organic compound is the one exhibiting minimun azeotropic point with water, e.g. chloroform, methylene chloride etc., and its amount is 0.1-10wt%, based on said mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a moisture-curable, room-temperature-curable composition comprising, as a base polymer, a polymer containing at least one hydrolyzable silicon group at the end and whose main chain consists essentially of polyether. Regarding.

In recent years, in the sealant industry, demand for one-liquid sealants has increased due to their superior workability, or a one-liquid sealant that satisfies all of the various quality requirements has not yet appeared. In particular, there are problems with storage stability.
It is desired that a one-component wetted product can be used for a long period of time and is free from problems such as coloration, discoloration, and odor.

The present invention solves these problems and provides a room temperature curable composition that can withstand long-term storage, does not discolor or stain, is odorless, and can be used as a one-component composition.

That is, the composition of the present invention contains at least one hydrolyzable silicon group at the end, and the main chain essentially has the formula -4'
A polyether having chemically bonded repeating units represented by -0- (R' is a divalent alkylene group) and having a molecular weight of 300 to 15,000, optionally containing a filler and a plasticizer. It is obtained by removing water in a mixture containing agents, additives, etc. by an azeotropic dehydration operation using a volatile organic compound.

The polyether used in the present invention has already been disclosed in Japanese Patent Publication No. 45-3.
6319, JP 1973-121.54, JP 50-1
56599, JP 53-186583 and JP 54
-6096 and the like are used.

The chemically bonded repeating unit represented by the formula -R1-0- includes, for example, -CH20-1-0)12CH20-
1 etc. These may be used alone or in a mixed form, but polyoxypropylene is particularly preferred.

The hydrolyzable silicon group at the terminal includes an alkoxy group, an alkenyloxy group, an acyloxy group, a keI-ximate group,
Examples include a silyl group or a silyloxysilyl group bonded with a hydrolyzable group selected from an amide group, an acid amide group, an aminooxy group, an amino group, and a mercapto group.

The filler used in the present invention is not special;
Examples include calcium carbonate, kaolin, talc, silica powder, titanium oxide, aluminum silicate, magnesium oxide, zinc oxide, carbon black, and synthetic resin powder.

Examples of plasticizers include known ones such as dioctyl phthalate-1-, butylbenzyl phthalate, epoxy octyl hexahydrophthalate, epoxidized soybean oil, and chlorinated paraffin. Various additives that may be added as necessary include hydrogenated castor oil, anti-sagging agents such as organic bentonite, anti-aging agents, coloring agents, and the like.

Volatile organic compounds that have a minimum azeotropic point with water include halides such as methylene chloride, chloroform, carbon tetrachloride, and trichloroethylene, alcohols such as ethanol, allyl alcohol, propatool, and butanol, ethyl acetate, and propionic acid. Esters such as methyl
Examples include ketones such as methyl ethyl ketone and 3-methyl-2-butanone; ethers such as ethyl ether and isopropyl ether; and hydrocarbons such as benzene, toluene, m-xylene and hexane. The amount used varies depending on the type of the organic compound and the composition (V) of the system, but it is usually 01 to 10% by weight of the above mixture.

The azeotropic dehydration operation can be carried out by various methods, or preferably, the polyether, filler, plasticizer and additives are charged in advance into a mixer or kneader with vacuum evacuation and heating equipment, and then they are uniformly dried. After kneading, the above-mentioned water azeotropic organic compound is added, and after further mixing uniformly, preferably 50
The objective is achieved by heating the system to ~90°C and taking out the water-organic compound azeotropic composition from the system while suctioning with a vacuum pump. Of course, the volatile organic compound may be added at or before crosstalk. Azeotropic dehydration operation is 1
The storage stability of the one-component ml product can be further strengthened by repeating the procedure not only twice but also two or three times, but one or two times is usually sufficient.

Further, after the azeotropic dehydration is completed, a curing catalyst is added and mixed uniformly to obtain a one-component room temperature curable composition.

As a curing catalyst, metal organic carboxylic acid salts such as tin octylate, tin stearate, iron naphthenate, lead octylate; so-n-butyltin dilaure-1, di-n-phthyltin siphthalate, dibutyltin oxide, etc. Organotin compounds such as reactants with esters, alkyl titanate compounds,
Amines and other known amines can be used alone or in mixtures.

In order to adjust the physical properties of the composition of the present invention, JP-A-53
-129247, polysiloxane as shown in JP-A-55-21453, and ultraviolet curable resin as shown in JP-A-55-36241.

The room temperature curable composition obtained by the present invention has excellent storage stability and can be stored for a long period of time if stored in a closed container. In addition, since it does not include a dehydration process using hydrolyzable compounds, it has the advantage that there are no problems such as discoloration, coloring, odor, or reduced elongation caused by hydrolyzable compounds. , it can be said that it has high practical significance.

The composition of the present invention is useful as an elastic sealant in fields such as architecture, automobiles, ships, and civil engineering, and can also be used as a paint or adhesive.

The present invention will be described below with reference to Examples, but the present invention is not limited by these.

Example 1 '80% of all ends of OH8 are (0HBO)25iCH20H20H
100 parts by weight of a 20-group polypropylene oxyto polymer with an average molecular weight of 8,000, 140 parts by weight of heavy calcium carbonate
Parts by weight, 20 parts by weight of titanium oxide, 1 part by weight of dioctyl phthalate
- 30 parts by weight, 8 parts by weight of hydrogenated castor oil, and 1 part by weight of styrenated phenol were placed in a jacketed mixer capable of evacuation and kneaded. When the moisture in the system is measured, it is 1500
It was ppm. Add 5 parts by weight of toluene to this and mix uniformly, then use a vacuum pump (10mmay) to
Azeotropic dehydration was carried out for 2 hours at 'C. The recovery rate of toluene was 98%. After the recovered 1-toluene was again put into the mixer and subjected to the same azeotropic dehydration operation, the water content in the system was measured and found to be 120 ppm. 1 part by weight of dibutyltin dilaure-I was added as a curing catalyst, and the mixture was uniformly kneaded and then transferred to a sealed container. The paste composition thus obtained still had good extrudability even after being stored at 50°C for 3 months. Furthermore, when exposed to the outside air, hardening progressed from the surface. An H-shaped test piece was prepared according to JIS 5758, and after curing at 23°C and 160% humidity for 14 days, and further curing at 30°C for 14 days, the tensile properties were as follows.

50% modulus 2.5 to 4 strength at break
6.4 K needle d elongation at break 46
0% After further curing at 90°C for 14 days, no change in physical properties, coloration, or discoloration was observed.

Comparative Example 1 The composition of Example 1, which was prepared by omitting only the toluene azeotropic dehydration operation, thickened when stored in a closed container at 50° C. for 11 days and could not be used.

Patent applicant Kanebuchi Chemical Industry Co., Ltd. Representative Patent Attorney Makoto Asano -

Claims (1)

[Scope of Claims] (1) A chemical compound containing at least one hydrolyzable silicon group and whose main chain is essentially represented by the formula -R'-0- (R' is a divalent alkylene group) A room-temperature curable composition obtained by removing water from a mixture whose main component is a polyether having bonded repeating units by an azeotropic dehydration operation using a volatile organic compound. (2) The hydrolyzable silicon group has the formula Oxy group, acyloxy group, ketoximate group, amide group, acid amide group, aminooxy group, amino group, mercapto group or silyloxy group having a hydrolyzable functional group, a is 0,1
or an integer of 2) according to claim 1. (3) Claim 1, Paragraph 1, where X is CH30-
Compositions as described in Section. (5) The composition according to claim 1, wherein the volatile organic compound has a minimum azeotropic point with respect to water in the system. (6) A composition according to claim 1, wherein the mixture contains a polyether and a filler, optionally a plasticizer and additives. (7) The composition according to claim 1, wherein the composition contains a curing catalyst and is a one-component type.