JPH07166050A - One-component thixotropic polyurethane composition - Google Patents

Abstract

PURPOSE:To obtain a compsn. improved in storage stability by compounding an NCO-terminated polyurethane prepolymer, CaCO3 surface-treated with a fatty acid ester, and a specific fatty acid silyl ester. CONSTITUTION:This compsn. comprises 100 pts.wt. NCO-termined polyurethane prepolymer having an NCO content of about 0.5-10wt.% or if necessary 100 pts. wt. the sum of such a prepolymer and a plasticizer and/or a solvent, 20-120 pts.wt. CaCO3 surface-treated with 1.0-10wt.% fatty acid ester, and a fatty acid silyl ester of formula II (wherein R<1> is H or a 1-20C monovalent org. group; R<2> is a 1-20C monovalent org. group; and m is 0-4) (e.g. stearoyloxytrimethylsilane of formula I) in an amt. of 0.1-20wt.% of the surface- treated CaCO3. The silyl ester is prepd. by reacting a carboxylic acid or its metal salt with a halosilane compd. in the presence of a tert. amine in a solvent (e.g. hexane).

Description

Detailed Description of the Invention

[0001]

The present invention relates to a joint material, a sealing material,
The present invention relates to a one-component thixotropic polyurethane composition having excellent thixotropy which can be used as an adhesive.

[0002]

2. Description of the Related Art A moisture-curable one-component polyurethane composition is used as a joint material and a sealing material. For such applications, thixotropy (thixotropy, slump resistance) is required, and for that purpose, a component having ethylene oxide in the structure or a colloidal silica is added, but in such a system, It has been pointed out that there are defects such as occurrence of foaming and cracks at the adhesive interface during curing, and high modulus, which makes it difficult to follow joints with movement.

On the other hand, JP-A-2-38309 proposes a method using calcium carbonate which is surface-treated with a fatty acid ester in place of colloidal silica, and this method uses colloidal silica. The above problems in case of doing are solved to a considerable extent.

[0004]

However, in order to add thixotropy by incorporating the above-mentioned calcium carbonate into the one-component polyurethane, a considerable amount is required. Although the amount varies depending on the composition of the polyurethane, it can be said that the amount is larger than the amount of the fatty acid-treated calcium carbonate used when imparting thixotropy with the two-component polyurethane. Therefore, problems such as storage stability and interface foaming and surface cracking during curing occur. In addition, the polyurethane composition containing the calcium carbonate has a problem that thixotropy such as thixotropy and slump resistance is rapidly reduced under the conditions of the melting point of the fatty acid ester as the surface treatment agent or higher.
Thus, the present invention has the advantages of a polyurethane composition using calcium carbonate surface-treated with a fatty acid ester as a thixotropic agent, and moreover, it is possible to impart thixotropy with a small amount of addition and to improve storage stability. An object is to provide an excellent polyurethane composition.

[0005]

According to the present invention, (A) a terminal isocyanate type polyurethane prepolymer (B) calcium carbonate surface-treated with a fatty acid ester and (C) a fatty acid represented by the following general formula (1) A one-pack thixotropic polyurethane composition containing a silyl ester as an active ingredient is provided, and the above object is achieved.

[Chemical 2] (In the formula, R ¹ is a hydrogen atom or a monovalent or divalent organic group having 1 to 20 carbon atoms, R ² is a monovalent or divalent organic group having 1 to 20 carbon atoms, and m is an integer of 0 to 4 Is)

[0006]

[Structure] The structure of the present invention will be described in detail below, but it will become apparent from the more preferable embodiments of the present invention and the advantages based thereon.

(A) Terminated isocyanate type polyurethane
Prepolymer The isocyanate group of the terminal isocyanate type polyurethane prepolymer, which is the component (A) used in the present invention, has a rubber elasticity in which the flexible main chain of the prepolymer serves as a matrix by reacting with moisture in the air to form a crosslinking point. A crosslinked structure is formed.

The polyurethane prepolymer having such a function may be any one generally used in a one-pack type polyurethane composition, and is not particularly limited. It can be obtained by reacting a polyol compound with an excess polyisocyanate compound. Examples of the polyether polyol include products obtained by addition-polymerizing one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran with a compound having two or more active hydrogens. You can

Examples of the compound having two or more active hydrogens include polyhydric alcohols, amines, alkanolamines, polyhydric phenols, and the like, and polyhydric alcohols include ethylene glycol and propylene. Glycol, butanediol, diethylene glycol, glycerin, hexanetriol, trimethylolpropane, pentaerythritol and the like, and amines such as ethylenediamine and hexamethylenediamine,
Examples of the alkanolamines include ethanolamine and propanolamine, and examples of the polyhydric phenols include resorcin and bisphenols.

As the polyester polyol,
Condensates of polyhydric alcohols and polybasic carboxylic acids, condensates of hydroxycarboxylic acids and polyhydric alcohols, polymerized products of lactones, and the like are exemplified, and as the polyhydric alcohols used for these, polyether polyol The compounds and the like exemplified in the item, as the polybasic carboxylic acid, for example, adipic acid, glutaric acid, azelaic acid, fumaric acid,
Maleic acid, phthalic acid, terephthalic acid, dimer acid, pyromellitic acid and the like can also be used.

Further, examples of the condensation product of hydroxycarboxylic acid and polyhydric alcohol include reaction products of castor oil and ethylene glycol, reaction products of castor oil and propylene glycol, and the like.

Further, as the lactone polymer, ε-caprolactone, α-methyl-ε-caprolactone, ε-
Examples thereof include those obtained by ring-opening polymerization of a lactone such as methyl-ε-caprolactone with an appropriate polymerization initiator and having hydroxyl groups at both ends.

The polymer polyol is obtained by graft-polymerizing the above-mentioned polyether polyol or polyester polyol with an ethylenically unsaturated compound such as acrylonitrile, styrene or methyl acrylate, or 1,
2- or 1,4-polybutadiene polyol, or a hydrogenated product of these. Examples of the polyol compound which is a raw material for producing the polyurethane prepolymer include the above compounds, and one or more kinds thereof may be used in combination, but those having a weight average molecular weight of about 100 to 10,000 are preferable.

As the polyisocyanate to be reacted with the above-mentioned polyol, various polyisocyanates used in the production of ordinary polyurethane resins can be used. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, phenylene diisocyanate, Xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, naphthylene-1,5-diisocyanate, and hydrogenated compounds thereof, ethylene diisocyanate,
Examples thereof include propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1-methyl-2,4-diisocyanate cyclohexane, 1-methyl-2,6-diisocyanate cyclohexane, dicyclohexylmethane diisocyanate, triphenylmethane triisocyanate and the like. These polyisocyanate compounds may be used alone or in combination of two or more.

The reaction between the polyol and the polyisocyanate is carried out by using polyisocyanate in excess, but usually, the molar ratio of the isocyanate group to the hydroxyl group (NCO / O) is used.
H) is performed at 1.1 to 3.0. Reaction temperature is room temperature ~ 1
The temperature is about 20 ° C., and an inert solvent can be used if necessary.

The terminal isocyanate type polyurethane prepolymer thus obtained preferably contains 0.5 to 10% by weight of an isocyanate group.

(B) Calcium carbonate as the calcium carbonate component (B) is surface-treated with a fatty acid ester, and the method thereof is described in JP-A-2-3830.
No. 9 is described in detail.

The fatty acid ester is preferably an ester of a higher fatty acid having 8 or more carbon atoms, and preferred examples thereof include stearyl stearate, lauryl stearate, stearyl palmitate, and lauryl palmitate.

As a method of surface-treating calcium carbonate with the above fatty acid ester, for example, a method of adding the fatty acid ester to an aqueous slurry of calcium carbonate and kneading to adsorb the fatty acid ester on the surface of calcium carbonate can be mentioned. .

The surface treatment amount of the fatty acid ester is usually 1.0 to 10% by weight based on calcium carbonate.

Calcium carbonate surface-treated with fatty acid ester is manufactured by Maruo Calcium Co., Ltd.
The product is sold under the trade name of 0 and CLEET'S 300 and can be preferably used.

(C) Fatty Acid Silyl Ester In the composition of the present invention, a fatty acid silyl ester represented by the following general formula (1) is used as an essential component.

[Chemical 3]Where R¹Is hydrogen atom or monovalent having 1 to 20 carbon atoms
Or divalent organic group, R ²Is monovalent with 1 to 30 carbon atoms
Is a divalent organic group. Among the organic groups, halogen
Group, alkoxy group, nitrile group, acid amide group, ester
Functional groups such as groups, epoxy groups and the like.

The method for synthesizing the fatty acid silyl ester represented by the above formula (1) is not particularly limited, but the following method is exemplified as an example. That is, the compound is synthesized from a carboxylic acid or a metal salt of a carboxylic acid and a halogen compound SiR ¹ _m X _4-m (2) (wherein R ¹ and m are the same as described above, and X represents a halogen atom). be able to.

In the above synthetic method, as the carboxylic acid, acetic acid, butyric acid, caproic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, Linear saturated fatty acids such as lignoceric acid, serotic acid, montanic acid, and melissic acid; unsaturated fatty acids such as caproreic acid, oleic acid, cetoleic acid, sorbic acid, linoleic acid, and linolenic acid; aromatics such as benzoic acid and phenylacetic acid It is used as one kind or a combination of two or more kinds of carboxylic acids such as carboxylic acid. Furthermore, the target fatty acid silyl ester can be synthesized by using a carboxylic acid metal salt instead of using the carboxylic acid.

Examples of the carboxylic acid metal salt include sodium, potassium, calcium, magnesium, aluminum and zinc salts of the above-mentioned carboxylic acid. At this time, the metal halide salt produced as a by-product can be easily removed by filtration.

Specific examples of the halogenated silane compound used include tetrachlorosilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltrichlorosilane, 2-chloroethyltrichlorosilane, ethyltrichlorosilane, 2-cyanoethyltrichlorosilane, Allyltrichlorosilane, 3-bromopropyltrichlorosilane, methylvinyltrichlorosilane, ethylmethyldichlorosilane, trimethylbromosilane, divinyldichlorosilane, methyl-3,
3,3-trifluoropropyldichlorosilane, isobutyltrichlorosilane, pentyltrichlorosilane, phenyltrichlorosilane, methylphenyldichlorosilane, dimethylphenylchlorosilane, cyclohexyltrichlorosilane, benzyltrichlorosilane, p-tolyltrichlorosilane, 6-trichlorosilyl- 2-norbornene, 2-trichlorosilyl norbornane, 2-
(4-cyclohexylnethyl) trichlorosilane,
Dodecyltrichlorosilane, tetradecyltrichlorosilane, 1,2-bis (trichlorosilyl) ethane, 1,
2-bis (dimethylchlorosilyl) ethane, 1,4-bis (dimethylchlorosilyl) benzene or other chlorosilane compounds may be used alone or in combination of two or more.

Specifically, the above carboxylic acid and chlorosilane compound are treated with hexane, heptane, benzene, toluene, xylene, methylene chloride, chloroform and the like having no active hydrogen as a solvent to remove tertiary amines such as triethylamine and pyridine. The reaction is performed at room temperature to 100 ° C. as a hydrogen chloride agent. By-produced hydrochloride is removed by filtration. Alternatively, it is also possible to synthesize without removing the hydrogen chloride gas produced at 120 to 180 ° C. without using a base as a dehydrochlorination agent.

The fatty acid silyl ester which is the component (C) of the present invention may be one kind or a mixture of plural kinds. The fatty acid silyl ester represented by the above formula (1) is the component (A).
It is preferable that 0.1 to 20 parts by weight is mixed with 100 parts by weight. The use of the component (C) fatty acid silyl ester as an essential component of the composition of the present invention is the most important requirement in the present invention. By blending this, storage stability is remarkably improved, and thixotropy based on the blending of the calcium carbonate surface-treated with the fatty acid ester (B) is exhibited even at a melting point of the fatty acid ester of the treating agent or higher. Perform a function. Further, the effect also appears in terms of preventing surface cracks and foaming.

Optional Ingredients In the composition of the present invention, in addition to the above-mentioned essential ingredients, a filler, a plasticizer, a solvent, in order to adjust viscosity, physical properties and the like.
Adhesion imparting agents, stabilizers, coloring agents and the like can be added.

Examples of the plasticizer include dioctyl phthalate, dibutyl phthalate, dilauryl phthalate, butyl benzyl phthalate, dioctyl adipate, diisodecyl adipate, trioctyl phosphate, propylene glycol adipate propylene glycol polyester, epoxidized soybean oil and the like. And is used in the range of 1 to 80% by weight based on the prepolymer.

Examples of the filler include ordinary calcium carbonate, carbon black, clay talc, titanium oxide, quick lime, kaolin, zeolite, diatomaceous earth, vinyl chloride paste resin, glass balloon, vinylidene chloride resin balloon, acrylonitrile / methacrylonitrile. There are resin balloons and the like, which can be used alone or in combination.

Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, heptane and octane, petroleum solvents such as gasoline to kerosene fraction, acetone, methyl ethyl ketone and methyl isobutyl ketone. The above-mentioned ketones, ether esters such as cellosolve acetate, butyl cellosolve acetate and the like are used, and are used in the range of 1 to 40% by weight based on the prepolymer.

A silane coupling agent or the like is used as an adhesion-imparting agent, and a hindered phenol compound, a triazole compound or the like is used as a stabilizer. Examples of colorants include titanium white, carbon black, red iron oxide, and the like.

The blending ratio (A) terminal isocyanate polyurethane prepolymer component is preferably occupied in the composition 20 wt% or more. Then, with respect to 100 parts by weight of the total amount of the liquid components comprising the polyurethane prepolymer and a plasticizer and / or a solvent optionally blended, the calcium carbonate surface-treated with the fatty acid ester as the component (B) is usually 20 to
120 parts by weight, particularly 40 to 100 parts by weight is preferably blended. With such a blending ratio, a composition having excellent thixotropy and storage stability can be obtained.

The fatty acid silyl ester compound as the component (C) is usually 0.1 to 20 parts by weight, particularly 0.5 to 10 parts by weight, relative to 100 parts by weight of the calcium carbonate as the component (B).
It is preferred to blend in parts by weight.

Preparation Method and Use of Composition The composition of the present invention comprises the above-mentioned essential components (A), (B),
It is prepared by mixing (C) and optional components to be blended, if desired, using a mixing device known per se, for example, a planetary mixer equipped with a vacuum device.

The composition thus prepared is stored while being shielded from water in the air. The composition of the present invention is a joint material,
It can be used as a sealing material, an adhesive material, or a coating agent.

[0038]

EXAMPLES The present invention will be specifically described below with reference to examples. Preparation of Polyurethane Prepolymer 500 g of polyoxypropylene glycol having a number average molecular weight of about 3000, 2000 g of polyoxypropylene triol having a number average molecular weight of about 3000, and 250 g of xylylene diisocyanate were placed in a three-necked flask and reacted at 80 ° C. to obtain an NCO content of 1 A urethane prepolymer of 0.5% by weight was obtained.

Fatty Acid Silyl Ester Synthetic Compound 2 100 g of stearic acid was placed in a three-necked flask and heated to 80 ° C.
After dehydration under reduced pressure for 1 hour, n-hexane (Dry) was added to 10
g, 35 g of dimethyldichlorosilane are added. 140
The mixture is refluxed at 4 ° C. for 4 hours, and then depressurized for 1 hour to distill off n-hexane and generated HCl. The obtained reaction liquid was filtered to obtain stearic acid dimethylsilylene ester (stearoyloxydimethylsilane). Compounds 1, 3, 4 and 5 were obtained by reacting a carboxylic acid and a halogenated silane compound in a solvent in the same manner as compound 2.

(Examples 1 to 7) Compound 1 was prepared as a prepolymer prepared above in a container with a stirrer, surface-treated calcium carbonate (fatty acid ester surface-treated by heating and drying) (Sealets 300: Maruo Calcium Co., Ltd.) and fatty acid silyl ester. 5 to 5 were added and kneaded at room temperature for 10 minutes, and then kneaded under vacuum for 30 minutes. At this time, the temperature of the composition reached about 55 ° C. Subsequently, dehydrated dioctyl phthalate and dehydrated xylene were added in the amounts shown in Table 1 and kneaded for 15 minutes in vacuum to obtain a one-component thixotropic polyurethane resin. CLEET'S 300 is a calcium carbonate surface-treated with a fatty acid ester (melting point 60 ° C.) and having an average primary particle size of about 0.07 μm and containing about 10% by weight of a fatty acid ester.

Comparative Examples 1 to 3 Compositions were prepared in the same manner as in Example 1 except that fatty acid silyl ester was not added.

The following evaluation was carried out on the above one-pack type polyurethane composition. (1) Thixotropy 20 ° C using a jig specified by JIS A5758
Under the environment of 60 ° C., 80 ° C. and 100 ° C., the slump test evaluated. (2) Storage stability Using a BS type viscometer, No. The viscosity was evaluated by measuring the viscosity immediately after preparation of the composition and after accelerated storage at 60 ° C. for 3 days under the condition of 7 rpm and 1 rpm. (3) Presence or absence of foaming and cracking The concrete joint (joint width 20 mm, depth 10 mm) was filled with the composition, and immediately left in an environment of 60 ° C. for curing, and then cracks and interfaces on the surface of the cured product and The inside foam was examined. The above results are shown in Table 2.

[0043]

[Table 1]

Table 1 Note

[Chemical 4]

[0045]

[Table 2]

As is clear from Table 2, the samples of Examples 1 to 7 in which the fatty acid silyl ester was added to Comparative Example 1 had good fluctuations at each environmental temperature, particularly at an environmental temperature of 60 ° C. or higher. Modification, that is, improvement in slump value was observed, storage stability was excellent, and neither surface cracking during curing nor foaming inside the cured product and at the interface was observed.

No fatty acid silyl ester was added,
Fatty Acid Ester Surface Treated Calcium Carbonate 160
In Comparative Examples 2 and 3 in which the amount was increased to 200 parts by weight, compared to Comparative Example 1, thixotropy in an environment of 60 ° C. or higher was slightly improved, but storage stability was significantly deteriorated and curing was difficult. There was a problem that many cracks were observed on the surface cracks and inside the cured product and at the interface.

[0048]

The novel one-pack thixotropic polyurethane resin composition of the present invention has excellent thixotropy at high temperature, that is, thixotropy and slump resistance are maintained, and storage stability is excellent, and at the time of curing. It has excellent properties such that cracks and bubbles are extremely unlikely to occur, and can be effectively used in a wide range of fields such as waterproof materials, adhesives, sealing materials and similar materials.

Claims (4)

[Claims] 1. A liquid containing (A) a terminal isocyanate-type polyurethane prepolymer (B) calcium carbonate surface-treated with a fatty acid ester and (C) a fatty acid silyl ester represented by the following general formula (1) as active ingredients. A thixotropic polyurethane composition. [Chemical 1] (In the formula, R ¹ is a hydrogen atom or a monovalent or divalent organic group having 1 to 20 carbon atoms, R ² is a monovalent or divalent organic group having 1 to 20 carbon atoms, and m is an integer of 0 to 4 Is) 2. The polyurethane composition according to claim 1, wherein the component (A) accounts for 20% by weight or more in the composition. 3. The component (B) is blended in an amount of 20 to 120 parts by weight based on 100 parts by weight of the total amount of the component (A) and a plasticizer and / or solvent optionally blended. 2. The polyurethane composition according to 2. 4. The component (C) is blended in an amount of 0.1 to 20 parts by weight with respect to 100 parts by weight of the component (B).
The polyurethane composition according to any one of claims.