JP2719105B2 - One-part thixotropic polyurethane composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Moisture-curable one-component polyurethane compositions are used as jointing materials and sealing materials. For such applications, thixotropic (thixotropic, slump resistance) is required. For this purpose, a component having ethylene oxide in its structure or a colloidal silica is added. It has been pointed out that foaming and cracking occur at the adhesive interface during curing, and that the modulus is high and it is difficult to follow moving joints.

On the other hand, Japanese Patent Application Laid-Open No. 2-38309 proposes a method using calcium carbonate surface-treated with a fatty acid ester instead of colloidal silica, and this method uses colloidal silica. The above-mentioned problem in the case of the above is considerably solved.

[0004]

However, in order to impart thixotropic properties by blending the above-mentioned calcium carbonate with a 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 thixotropic properties with the two-component polyurethane. Therefore, there have been problems such as storage stability, interfacial foaming during curing, and generation of surface cracks. Further, the polyurethane composition containing the above calcium carbonate also has a problem that the thixotropic properties such as thixotropy and slump resistance are rapidly reduced under the condition of the melting point of the fatty acid ester as the surface treating agent or more.
Thus, the present invention has the advantage of a polyurethane composition using calcium carbonate surface-treated with a fatty acid ester as a thixotropic agent, and can impart thixotropic properties with a small amount of addition, resulting in improved storage stability. An object is to provide an excellent polyurethane composition.

[0005]

According to the present invention, there are provided (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.

Embedded image (Wherein, R ¹ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, R ² is a monovalent organic group having 1 to 20 carbon atoms, and m is 0.
~ 3 is an integer)

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the constitution of the present invention will be described in detail, but more preferred embodiments of the present invention and advantages based thereon will become apparent.

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

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

The compounds having two or more active hydrogens include, for example, polyhydric alcohols, amines, alkanolamines, polyhydric phenols and the like. Polyhydric alcohols include ethylene glycol, propylene Glycol, butanediol, diethylene glycol, glycerin, hexanetriol, trimethylolpropane, pentaerythritol, etc., as amines, ethylenediamine, hexamethylenediamine, etc.,
Alkanolamines include ethanolamine, propanolamine and the like, and polyhydric phenols include resorcinol and bisphenol.

[0010] As the polyester polyol,
Condensates of polyhydric alcohols and polybasic carboxylic acids, condensates of hydroxycarboxylic acids and polyhydric alcohols, lactone polymers and the like are exemplified.As the polyhydric alcohol used for these, the polyether polyol Compounds and the like exemplified in the section, as a 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 condensates of hydroxycarboxylic acid and polyhydric alcohol include reaction products of castor oil and ethylene glycol, and reaction products of castor oil and propylene glycol.

The lactone polymers include ε-caprolactone, α-methyl-ε-caprolactone, and ε-caprolactone.
Lactones such as methyl-ε-caprolactone are subjected to ring-opening polymerization with a suitable polymerization initiator, and those having hydroxyl groups at both terminals can be mentioned.

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

As the polyisocyanate to be reacted with the polyol, various ones 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 include propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1-methyl-2,4-diisocyanatecyclohexane, 1-methyl-2,6-diisocyanatecyclohexane, dicyclohexylmethane diisocyanate, and triphenylmethane triisocyanate. 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 using an excess of the polyisocyanate. Usually, the molar ratio of the isocyanate group to the hydroxyl group (NCO / O
H) is performed in 1.1 to 3.0. Reaction temperature is from room temperature to 1
The temperature is about 20 ° C., and an inert solvent can be used if necessary.

The thus obtained isocyanate-terminated polyurethane prepolymer preferably contains 0.5 to 10% by weight of isocyanate groups.

(B) Calcium carbonate component The calcium carbonate component (B) is surface-treated with a fatty acid ester.
No. 9 describes this in detail.

As the fatty acid ester, an ester of a higher fatty acid having 8 or more carbon atoms is preferable, and examples thereof include stearyl stearate, lauryl stearate, stearyl palmitate, lauryl palmitate and the like.

As a method of surface-treating calcium carbonate with the above fatty acid ester, for example, a method of adding a fatty acid ester to an aqueous slurry of calcium carbonate and kneading the mixture 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 a fatty acid ester was obtained from Maruo Calcium Co., Ltd.
0, sold under the trade name SERETS 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.

Embedded imageWhere R¹Is a hydrogen atom or a monovalent having 1 to 20 carbon atoms
Or a divalent organic group, R ^TwoIs monovalent having 1 to 30 carbon atoms
Is a divalent organic group. In the organic group, halogen
Group, alkoxy group, nitrile group, acid amide group, ester
And functional groups such as epoxy groups.

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 above, and X represents a halogen atom). be able to.

In the above synthesis method, the carboxylic acids include acetic acid, butyric acid, caproic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachinic acid, behenic acid, Linear saturated fatty acids such as lignoceric acid, cerotic acid, montanic acid, and melicinic acid; unsaturated fatty acids such as caproleic acid, oleic acid, cetreic acid, sorbic acid, linoleic acid, and linolenic acid; It is used as one or a combination of two or more carboxylic acids such as carboxylic acids. Furthermore, even if a metal salt of a carboxylic acid is used instead of using a carboxylic acid, the desired fatty acid silyl ester can be synthesized.

Examples of the metal carboxylate include sodium, potassium, calcium, magnesium, aluminum and zinc salts of the above-mentioned carboxylic acids. At this time, the metal halide by-produced 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-trichlorosilylnorbornane, 2-
(4-cyclohexynylethyl) trichlorosilane,
Dodecyltrichlorosilane, tetradecyltrichlorosilane, 1,2-bis (trichlorosilyl) ethane, 1,
One or a combination of two or more of 2-bis (dimethylchlorosilyl) ethane, 1,4-bis (dimethylchlorosilyl) benzene, and other chlorosilane compounds is used.

Specifically, tertiary amines such as triethylamine and pyridine are removed from the above carboxylic acid and chlorosilane compound using hexane, heptane, benzene, toluene, xylene, methylene chloride, chloroform or the like having no active hydrogen as a solvent. The reaction is carried out at room temperature to 100 ° C. as a hydrogen chloride agent. By-product hydrochloride is removed by filtration. Alternatively, the synthesis can be carried out without using a base as a dehydrochlorinating agent and removing hydrogen chloride gas generated at 120 to 180 ° C.

One or more kinds of fatty acid silyl esters as the component (C) of the present invention may be mixed. The fatty acid silyl ester represented by the above formula (1) is a component (A)
It is preferable to add 0.1 to 20 parts by weight to 100 parts by weight. The use of the fatty acid silyl ester of the component (C) as an essential component of the composition of the present invention is the most important requirement in the present invention. By blending this, the storage stability is remarkably improved, and the thixotropic property based on the blending of (B) the calcium carbonate surface-treated with the fatty acid ester is exhibited even when the melting point of the fatty acid ester of the treating agent is higher than the melting point. Perform the function. In addition, an effect appears in preventing surface cracks and foaming.

Optional Components In the composition of the present invention, in addition to the above essential components, a filler, a plasticizer, a solvent,
An adhesion promoter, a stabilizer, a colorant, 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 polyester, alkyl epoxystearate, epoxidized soybean oil and the like. And 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, quicklime, 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 as a mixture.

Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, heptane and octane, petroleum solvents ranging from gasoline to kerosene fraction, acetone, methyl ethyl ketone and methyl isobutyl ketone. Ketones, ether esters such as cellosolve acetate and butyl cellosolve acetate, etc., 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 or a triazole compound is used as a stabilizer. Examples of the coloring agent include titanium white, carbon black, red iron and the like.

The blending ratio (A) terminal isocyanate polyurethane prepolymer component is preferably occupied in the composition 20 wt% or more. Then, the calcium carbonate surface-treated with the fatty acid ester as the component (B) is usually added in an amount of 20 to 100 parts by weight of the total amount of the liquid component comprising the polyurethane prepolymer and the plasticizer and / or the solvent optionally blended.
It is preferable to mix 120 parts by weight, particularly 40 to 100 parts by weight. With such a mixing ratio, a composition excellent in thixotropic 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, based on 100 parts by weight of the calcium carbonate as the component (B).
It is preferable to mix by weight.

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

The composition thus prepared is stored in a state where it is 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, and a coating agent.

[0038]

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 3,000, and 250 g of xylylene diisocyanate were placed in a three-necked flask and reacted at 80 ° C. to give an NCO content of 1 A urethane prepolymer of 0.5% by weight was obtained.

Synthetic Compound 2 of Fatty Acid Silyl Ester 100 g of stearic acid was placed in a three-necked flask,
And dehydrated under reduced pressure for 1 hour, and n-hexane (Dry) was
g, 35 g of dimethyldichlorosilane. 140
The mixture was refluxed at 4 ° C. for 4 hours, and then depressurized for 1 hour to distill off n-hexane and generated HCl. The obtained reaction solution was filtered to obtain dimethylsilylene stearate (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 in Compound 2.

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

Comparative Examples 1 to 3 Compositions were prepared in the same manner as in Example 1 except that no fatty acid silyl ester was added.

The following evaluation was performed on the above one-pack type polyurethane composition. (1) Thixotropic 20 ° C. using a jig specified in JIS A5758
It evaluated by the slump test under the environment of below, 60 degreeC, 80 degreeC, and 100 degreeC. (2) Storage stability Using a BS type viscometer, The viscosity was evaluated by measuring the viscosity immediately after the preparation of the composition and after the accelerated storage at 60 ° C. for 3 days under the condition of 1 rpm with 7 rotors. (3) Presence or absence of foaming and cracks After filling the composition into a concrete joint (joint width 20 mm, depth 10 mm) and immediately leaving it to stand at 60 ° C. to cure it, cracks and interfaces on the surface of the cured product and The foam inside was examined. Table 2 shows the above results.

[0043]

[Table 1]

Table 1 Note

Embedded image

[0045]

[Table 2]

As is evident from Table 2, the compositions of Examples 1 to 7 in which the fatty acid silyl ester was added to Comparative Example 1 exhibited good vibration even at each environmental temperature, particularly at an environmental temperature of 60 ° C. or more. Modification, that is, improvement of the slump value was observed, storage stability was excellent, and no generation of surface cracks during curing and foaming inside the cured product and at the interface were observed.

Without adding any fatty acid silyl esters,
Add 160 more fatty acid ester surface treated calcium carbonate
In Comparative Examples 2 and 3 in which the amount was increased to 200 parts by weight, the thixotropic property in an environment of 60 ° C. or more was slightly improved as compared with Comparative Example 1, but the storage stability was significantly deteriorated and the curing time There has been a problem that a large number of foams are observed at the surface cracks, inside the cured product and at the interface.

[0048]

The novel one-part thixotropic polyurethane resin composition of the present invention has excellent thixotropic properties even at high temperatures, that is, it has excellent storage stability while maintaining thixotropy and slump resistance, and has a high degree of storage stability. It has excellent performance such that cracks and bubbles hardly occur, and can be used very effectively in a wide range of fields such as waterproofing materials, adhesives, sealing materials and similar materials.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-54-133538 (JP, A) JP-A-50-51131 (JP, A) JP-A-4-298590 (JP, A) JP-A-Heisei 4- 370146 (JP, A) JP-A-63-191820 (JP, A)

Claims (4)

(57) [Claims] 1. A liquid containing (A) an isocyanate-terminated 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. Embedded image (Wherein, R ¹ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, R ² is a monovalent organic group having 1 to 20 carbon atoms, and m is 0.
~ 3 is an integer) Wherein請<br/> Motomeko polyurethane composition according to 1, wherein the component (A) is 2 0% by weight or more. Wherein said component (B), is 20 to 120 parts by weight per 100 parts by weight of the total amount of components (A) alone or <br/> components (A) and a plasticizer and / or solvent Claim 1 or 2
The polyurethane composition according to the above. 4. The composition according to claim 1, wherein component (C) is added in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of component (B).
The polyurethane composition according to any one of the above.