JPS5857457A - Room temperature curing composition - Google Patents

Abstract

PURPOSE:To provide a compsn. which contains, as effective ingredients, hydrolyzable silicon groups and silanol group-contg. polyether and polysulfide, cures at room temperature to form a rubbery substance when brought into contact with moisture and exhibits reduced residual tackiness and improved weather resistance and adhesive property. CONSTITUTION:The compsn. contains, as effective ingredients, (A) polyether with a molecular weight of 500-15,000 which contains hydrolyzable silicon groups of formulaI[where a is 0-2; R is a univalent hydrocarbon group; X is a hydrolyzable group (e.g., methoxy group)]and/or silanol group and has chemically bonded repeating units represented by R-O (where R is a divalent alkylene group) in the main chain and (B) polysulfide polymer with a molecular weight of 300-15,000 which has a main chain consisting substantially of formula II and contains 0.01-5wt% mercaptan group as functional group.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a residual material containing as active ingredients a hydrolyzable silicon- and/or silanol-containing polyether that can cure at room temperature into a rubber-like substance when exposed to moisture, and a polysulfide polymer. This invention relates to a composition with improved tack, weather resistance, and adhesion.

The present inventors have already discovered that moisture-curable polyethers having silicon groups are useful as sealants, and have previously proposed methods and compositions for their production.

Room-temperature-curing sealants whose main component is polyethyl having a moisture-curable silicon group are inexpensive and have excellent performance, but depending on the composition, the surface of the cured product may become sticky over a long period of time, adsorbing dust, and causing drying. There was a problem of surface contamination.

As a result of intensive studies to improve this point, the inventors of the present invention have found that by adding a polysulfide polymer, the objective can be achieved without impairing the excellent properties of moisture-curable polyether having silicon groups. The present invention was achieved based on the discovery that

That is, the present invention provides (4) a chemical containing at least one hydrolyzable silicon group and/or silanol group and whose main chain is essentially -R-0- (R is a divalent alkylene group). a polyether having repeating units bonded together and having a molecular weight of 500 to 15,000;
(B) A room temperature curable composition containing a polysulfide polymer as an active ingredient.

In the present invention, a polyether having a room temperature curable silicon group is one whose main chain is essentially chemically bonded with -R-0- (R is a divalent alkylene group) and has repeating units such as It is a polymer consisting of polyether having a molecular weight of 500 to 15,000 and having at least one hydrolyzable group bonded to a silicon atom in one molecule. Here, what is meant by essentially having one -R-0 unit means that it may contain a small amount of other bonding units depending on the polyether manufacturing method, as will be described later. Hydrolyzable groups bonded to silicon atoms typically include hydride groups, halogen groups, alkoxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, aminooxy groups, mercapto groups, and alkenyloxy groups. .

Room-temperature-curable polyether having a silicon group can be produced by various known methods, but is preferably produced by using a silicon hydride compound of formula (1) (X is the hydrolyzable functional group) and formula (2). % formula % (2) (R1' is hydrogen or a monovalent organic group having 1 to 2 carbon atoms, R
3 is a divalent organic group having 1 to 20 carbon atoms, and b is an integer of 0 or 1. . Specifically, this type of polyether is disclosed in Japanese Patent Application Laid-open No. 50-156599,
It can be obtained by the methods disclosed in JP-A-54-6096, JP-A-55-13768, JP-A-55-82123, and JP-A-55-131022. In addition to this, JP-A-55-13767, JP-A-55-123620.
JP-A-55-125121, JP-A-55-]-
3102,1, JP-A-55-137129, JP-A-55
It is also possible to use a polyether having a room temperature curable silicon group obtained by the method disclosed in -135135 (3). Only one type of these polyethers can be used.

or a mixture of two or more types may be used.

The polysulfide polymer used in the present invention essentially has -CH2Q T-(2S S -1
-CH20, H2S SS 5-1- C5H,. S
Alkylene boris/l/7 id with basic unit structure represented by S-, -C6H, 2SS-, etc.: C
2H40C2H455-1-C2H4002I (4S
S S S-1-C2H40CH20C2■tSS--
c4■-4o c H2o C4H3S S-1-C4
Polysulfides having a basic unit structure containing an ether bond such as H80C4H8sS- are effective, but are not limited thereto. In particular, polysulfide having the basic unit structure of -C](4o CH20C2H45S- is effective.Also, polysulfide having a mercaptan functional group on the side chain or at the end of the molecule as a functional group is more effective.The molecular weight is 300 to 15,000. It is preferable to have a mercaptan functional group in the range of 0.01 to 5% by weight, but it is not limited to this range and can be used alone or in combination. It is more effective if it exists.

The polysulfide polymer containing mercaptan functional groups may be a metal oxide, an organic peroxide, a quinonediochytum,
It can be cured with various curing agents such as phenol resins, epoxy resins, and isocyanates, and the present invention also includes the use of these various existing curing agents in combination. The polysulfide polymer is used in an amount of 0.1 to 100 parts by weight, preferably 0.1 to 30 parts by weight, per 100 parts by weight of the silyl group-containing polyether.

The present invention has the effect that not only the residual tack on the surface of the cured product is improved, but also the weather resistance of the sealant itself and the adhesion to each adherend are improved.

In curing the compositions of the present invention, a 7-lanol condensation catalyst may or may not be used.

If condensation catalysts are used, alkyl titanates; organosilicon titanates; metal salts of carboxylic acids such as tin octylate, diptyltin laurate and diptyltin maleate, dibutyltin phthalate, etc.; dibutyamine-2-ethyl Known silanol condensation catalysts such as amino acids such as hexoates; and other acidic and basic catalysts are usefully used. The amount of these condensation catalysts used is preferably 0 to 10% by weight based on the silicon group-containing polyether. When an alkoxy group is used as the hydrolyzable group X, it is preferable to use a condensation catalyst since the curing rate is slow if this polymer alone is used.

In this case, a tin carboxylate is particularly preferred as the condensation catalyst.

The silicon group-containing polyether of the present invention can be modified by incorporating various fillers. Fillers include reinforcing fillers such as silica, precipitated silica, anhydrous silicic acid, hydrated silicic acid and carbon black; calcium carbonate, magnesium carbonate, diatomite, calcined clay, clay, Merck, titanium oxide, bentonite, organic bentonite,
Fillers such as ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and shirasu balloons; fibrous fillers such as asbestos, glass fibers and filaments can be used.

If you want to obtain a hardened composition with high strength using these fillers, you should mainly use tum silica, precipitated silica, silicic anhydride, silicic acid containing, carbon black, surface-treated fine calcium carbonate,
1 part by weight of a filler selected from fired clay, clay, activated zinc white, etc. per 100 parts by weight of silicon group-containing polyether.
Preferable results can be obtained if the amount is used in the range of 100 parts by weight. In addition, if it is desired to obtain a cured composition with low strength and moderate elongation, fillers mainly selected from titanium oxide, calcium carbonate, magnesium carbonate, talc, ferric oxide, zinc oxide, and shirasu balloons can be used. Favorable results can be obtained if it is used in an amount of 5 to 200 parts by weight per 100 parts by weight of the silicon group-containing polyether. Of course, these fillers may be used alone or in a mixture of two or more.

In the present invention, it is more effective to use a plasticizer in combination with a filler because the elongation of the cured product can be reduced and a large amount of filler can be mixed.

As the plasticizer, commonly used phthalate esters such as dioctyl phthalate, dibutyl phthalate, butylbenzyl phthalate, etc.; aliphatic esters such as dioctyl adipate, isodecyl conophosphate, dibutyl sepacate, etc. Basic acid esters; diethylene glycol dipenzoate, pentaeris IJ)'
- glycol esters such as esters; aliphatic niskels such as butyl oleate, methyl acetyl ricinoleate; phosphate esters such as tricresyl phosphate, trioctyl phosphate, octyldiphenyl phosphate; epoxidized soybean oil , epoxy plasticizers such as benzyl epoxy stearate; plasticizers such as chlorinated paraffin can be optionally used alone or in the form of a mixture of two or more types. The amount of plasticizer is silicon group-containing polyether 10
Preferable results are obtained when the amount is used in the range of 0 to 100 parts by weight. Fillers, plasticizers, and condensation catalysts are mainly used in the compounded composition of the present invention. Modifiers such as polysiloxane contained; tanks and weather resistance improvers such as ultraviolet curable resins; additives such as pigments, anti-aging agents, ultraviolet absorbers, etc. may also be optionally used.

The composition of the present invention can be either a one-part composition or a two-part composition. When used as a two-component composition, for example, a component consisting of a silicon group-containing polyether, an organic silane polymer, a filler, and a plasticizer, and a component consisting of a filler, plasticizer, and condensation catalyst are used. Good results can be obtained if both components are mixed immediately before use. When used as a one-component composition, the silicon group-containing polyether, organic silane polymer, filler, plasticizer, and condensation catalyst are thoroughly dehydrated and dried, then mixed in the absence of moisture, and stored in a cartridge or the like. If kept, it can be used as a one-component composition with good storage stability.

The compositions of the present invention are particularly useful as one-part and two-part elastic sealants and can be used as sealants for buildings, ships, automobiles, roads, etc. Furthermore, it can be used alone or with the aid of a primer to adhere to a wide range of substrates such as glass, porcelain, wood, metal, resin moldings, etc., and thus can be used in various types of sealing and adhesive compositions. It is. In addition, food packaging materials, casting rubber materials, molding materials, and paints.

It is also useful as

Examples will be specifically described below.

Example 1 20 dioctyl epoxy hexahydrophthalate was added to 100 parts by weight of polypropylene oxide having an average molecular weight s, ooo and 80% of it as end groups.
Parts by weight, 45 parts by weight of dioctyl phthalate, xylene resin (Mitsubishi Gas Chemical Exhibition, trade name dicanol I (H,) 2
0 parts by weight, 100 parts by weight of fatty acid-treated calcium carbonate (Shiraishi Calcium Ring, trade name C]R), 175 parts by weight of ground calcium carbonate, 15 parts by weight of titanium oxide, 6 parts by weight of hydrogenated castor oil, 0. 5 parts by weight, 1 part by weight of 2,2-methylene-bis-(4-methyl-6-tert-butylphenol), 2(2'-hydroxy-a,5-tert-butylphenyl)-5-10robenzotriazole 1 part by weight, 5 parts by weight of oligoester acrylate
parts by weight, 3 parts by weight of sulfur, 3 parts by weight of tin octylate, 75 parts by weight of laurylamine, polysulfide polymer (
Add 5 parts by weight of Toshi Thiokol (trade name: LP-32) and mix well using three paint rolls. Then 3 y
A sheet with a thickness of tm was prepared and cured for 30 days at 23°, 050% humidity, and then the residual tack was determined by finger touch. The determination method is as follows.

◎: Level where no tuck is observed even if you press firmly with your fingertips ○ Level where tucks are not observed when you lightly touch with your fingertips, but some tackiness is observed when you press strongly △゛ Level where tucks are observed even when you lightly touch with your fingertips Example The results are shown in Table 1 together with the results of a comparative example, which was tested in exactly the same manner as in Example 1 except that the polysulfide polymer was added less frequently.

Table 1 In addition, this cured product sheet was used as Sunshine WOM11000.
When observing the surface condition of the sheet after being irradiated for a period of time, it was found that the sort obtained in Comparative Example had a slight cracking on the surface, whereas the sheet obtained in Example 1 had no clearing at all. .

Example 2 In Example 1, instead of adding 5 parts by weight of polysulfide polymer and using 100 parts by weight of silicon-terminated polyether, 80 parts by weight of silicon-terminated polyether, 20 parts by weight of polysulfide polymer, and lead peroxide were used. (PbO2
) A cured sheet was prepared in exactly the same manner as in Example 1, except that 2 parts by weight was used, and the residual tank was determined to be at a level of ◎.

Examples 3 to 4 Instead of using Okibe, 50% of LP-2 or P-3 (all polysulfide polymers manufactured by Toshi Thiokol) were used.
A cured sheet was prepared in exactly the same manner as in Example 1, except that parts by weight were used, and the residual tack was determined, and the results shown in Table 2 were obtained.

Table 2 Patent applicant Kanebuchi Chemical Industry Co., Ltd. Agent: Patent Attorney Makoto Asano - Japanese Patent Publication No. 58-57457 (5)

Claims (1)

Scope of Claims: (1) (A) contains at least one hydrolyzable silicon group and/or silanol group, and the main chain is essentially -R-
A polyether having chemically bonded repeating units represented by 0-(R is a divalent alkylev group) and having a molecular weight of 500 to 15'000; (6) a polysulfide polymer; A room temperature curable composition containing as an active ingredient. (2) A hydrolyzable silicon group bonded to a silicon atom: a group consisting of an idlide group, a halogen group, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group, and an alkenyloxy group At least one type selected from the following claims (where a is an integer of 0 to 2, R is a monovalent hydrocarbon group, and X is a hydrolyzable group) Room temperature curable composition according to item 1. (4) The room temperature curable composition according to claim 3, wherein X is a methoxy group. (5) The polysulfide polymer is a polymer with a molecular weight of 300 to 15,000 whose main chain structure essentially consists of the formula A room temperature curable composition according to claim 1.