JP6817505B2 - Sealant composition - Google Patents

Description

The present invention relates to a polyurethane-based sealant composition having excellent curability, excellent storage stability, initial adhesiveness to concrete, mortar, and the like, and excellent water resistance.

Polyurethane resin can be cured at room temperature and has excellent properties such as rubber elasticity, abrasion resistance, and durability. Therefore, paints, flooring materials, waterproof materials, adhesives, potting materials, wall materials, sealing materials, etc. It has been particularly used in recent years. These polyurethane resin curing methods include a one-component type in which the terminal isocyanate of the urethane prepolymer is cured by moisture in the air after construction, and a curing agent containing a main agent containing urethane prepolymer and polyols at the time of construction. It is roughly divided into a two-component type that is mixed and cured.

In the two-component type, the curing speed can be easily adjusted, but each component needs to be mixed at the time of construction, which is complicated to handle. On the other hand, the one-component type has problems such as slow curing, poor storage stability, and foaming, although the construction method is simple. In addition, the sealing material using aromatic diisocyanate has low flexibility due to its excellent high cohesive force derived from its benzene ring, and has high modulus during elongation, so it does not follow the expansion and contraction of the joints constructed, and the joints. Has the problem of destroying.

In order to solve these problems, a one-component polyurethane composition containing a latent curing agent has been proposed. For example, Patent Document 1 discloses a polyurethane composition containing polyaldimine as a latent curing agent.

However, these compositions have problems in curability, such as a significant decrease in curability when they are constructed in a low temperature and low humidity environment such as in winter.

Further, in Cited Document 2, there is also a method of adding an organic acid to the composition in advance for the purpose of improving the curability, but in this case, the long-term storage property of the composition deteriorates in proportion to the addition amount. Therefore, practical use is limited.

On the other hand, conventionally, a method of using a silane coupling agent for imparting adhesiveness to a polyurethane composition has been known, but when a large amount is added, the alcohol generated from the silane coupling agent is an isocyanate of a urethane prepolymer. There is a problem that it reacts with the group and causes curing failure.

In addition, conventional one-component polyurethane compositions do not have excellent water resistance as well as initial adhesiveness to concrete and mortar, and a primer containing a silane coupling agent is applied to places where waterproofness is required. There is a need to.
Japanese Unexamined Patent Publication No. 2010-18755 Japanese Unexamined Patent Publication No. 2013-2108

The present invention provides a sealant composition having excellent curability and excellent storage stability, and having excellent initial adhesiveness to concrete, mortar, etc., and water resistance. With the goal.

The solution to the above problem was achieved by the following.
(1) At least
(A) Urethane prepolymer, which is a reaction product of a polyether polyol having an ethylene oxide chain and a propylene oxide chain and a polyisocyanate compound.
(B) Biuret of diisocyanate,
Sealant composition containing and.
(2) The sealing material composition according to claim 1, wherein the diisocyanate of (B) is hexamethylene diisocyanate.

According to the present invention, it is a sealing material composition having excellent curability and excellent storage stability, and has excellent initial adhesiveness to concrete, mortar, etc. and water resistance even without using a primer. An excellent sealant composition can be provided.

Embodiments of the present invention will be described below, but these embodiments are shown by way of example, and various modifications can be made without departing from the technical idea of the present invention.

The sealant composition of the present invention comprises at least (A) a urethane prepolymer which is a reaction product of a polyether polyol having an ethylene oxide chain and a propylene oxide chain and a polyisocyanate compound, and (B) a biuret of diisocyanate. It is characterized by being a sealing material composition contained.

<(A) Urethane prepolymer>
The urethane prepolymer (A) of the present invention is characterized by being a reaction product of a polyether polyol having an ethylene oxide chain and a propylene oxide chain and a polyisocyanate compound.

As the polyether polyol having an ethylene oxide chain and a propylene oxide chain, a known polyether polyol having an ethylene oxide chain and a propylene oxide chain can be widely used and is not particularly limited, but for example, 1 to 30% by mass is preferable. Is preferably used as a polyoxypropylene main chain polyol polymerized with propylene oxide, which has a 10 to 20% by mass ethylene oxide chain at the end.

The number average molecular weight of the polyether polyol is not particularly limited, but is preferably 500 to 10,000, more preferably 1,000 to 6,000.

These polyether polyols may be used alone or in combination of two or more. Further, if necessary, a known polyether polyol other than the ethylene oxide chain and the polyether polyol having the propylene oxide chain may be used in combination.

The polyisocyanate compound (A) refers to a compound having two or more isocyanate groups in one molecule, preferably a compound containing 2 to 5 isocyanate groups in one molecule, and has an alkylene group, a cycloalkylene group, and a phenylene. More preferably, two or more isocyanates are bonded to the group or the like.

For example, aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), naphthalene diisocyanate, xylylene diisocyanate (XDI), aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI) and lysine methyl ester diisocyanate. , Hydrocyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, norbornan diisocyanate, hydrogenated tolylene diisocyanate, etc. Among these, MDI is used from the viewpoint of toxicity, reactivity, price, etc. preferable. These polyisocyanate compounds may be used alone or in combination of two or more.

The reaction between the polyether polyol and the polyisocyanate compound is carried out so that the isocyanate group becomes excessive, that is, the NCO / OH equivalent ratio becomes larger than 1. The reaction conditions are not particularly limited, but for example, at a ratio of NCO / OH equivalent ratio of 1.3 to 10.0, more preferably at a ratio of 1.5 to 5.0, 70 in a nitrogen or dry air stream. It is produced by reacting at ~ 100 ° C. for several hours.

The urethane prepolymer (A) may be used alone or in combination of two or more. Further, in addition to (A) urethane prepolymer, other known urethane prepolymers may be used in combination, if necessary.

<Biuret body of diisocyanate>
The biuret form of (B) diisocyanate refers to a compound having a structure of R-NH-CO-NR'-CO-NH-R'' in which a large amount of diisocyanate is added. In particular, a biuret form of hexamethylene diisocyanate is preferable. When the biuret form of hexamethylene diisocyanate is obtained, the isocyanurate form of hexamethylene diisocyanate may be contained in a side reaction, but if the biuret form is 50% by mass or more, it can be preferably used.

The blending ratio of the biuret form of diisocyanate can be 0.5 to 20% by mass with respect to the urethane prepolymer (A), and is preferably 5 to 15% by mass.

<Other ingredients>
The sealant composition of the present invention contains at least (A) urethane prepolymer and (B) diisocyanate biuret, but as other components, (C) polyalkylene ether monool and hexa as plasticizers having urethane bonds. It preferably contains a urethane compound obtained by reacting with methylene diisocyanate.

<< (C) Urethane compound obtained by reacting polyalkylene ether monool with hexamethylene diisocyanate >>
In the present invention, the urethane compound has a function as a plasticizer for the polyurethane resin composition.

The method for producing the polyalkylene ether monool constituting the urethane compound of the present invention is not particularly limited and can be obtained by a known production method. For example, a compound having a hydroxyl group as one active hydrogen group at the molecular terminal can be used. A polymerized alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and styrene oxide alone, a copolymerized product, or a mixture of these polymers can be used.

Examples of the compound having a hydroxyl group as one active hydrogen group at the end of the molecule include aliphatic monoalcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol and octanol; cyclopentanol, dimethylcyclohexanol and the like. Examples thereof include alicyclic monoalcohols; aromatic aliphatic monoalcohols such as benzyl alcohol; aromatic (phenolic) monoalcohols such as phenol and cresol; and other monoalcohols.

The polyalkylene ether monool of the present invention may be used alone or in combination of two or more. The OH value of the polyalkylene ether monool is preferably 5.5 to 281.0 [mgKOH / g], more preferably 11.0 to 140.3 [mgKOH / g], and 24 to 125 [mgKOH / g]. More preferred. As the polyalkylene ether monool, polyoxypropylene monool (including those containing a polyoxyethylene unit) is preferable.

The reaction between the polyalkylene ether monool and hexamethylene diisocyanate is preferably carried out under reaction conditions of 40 ° C to 100 ° C. For this reaction, it is preferable that the equivalent ratio of NCO / OH is 1.1 / 1.0 to 1.0 / 1.1. By reacting the hydroxyl groups of the polyalkylene ether monool with the isocyanate groups, not only the hydroxyl groups are blocked, but also substantially all the isocyanate groups are blocked.

It is preferable that the content of the isocyanate group remaining in the urethane compound (C) is 0.1% by mass or less from the viewpoint of further suppressing foaming. In order to shorten the reaction time between the polyalkylene ether monool and hexamethylene diisocyanate, it is preferable to use a catalyst such as a tertiary amine, a tin catalyst, or a bismuth catalyst.

The urethane compound (C) preferably has a viscosity at 25 ° C. of 10,000 mPa · s or less, and more preferably 500 mPa · s or more and 7,000 mPa · s or less.

The blending ratio of the component (C) is not particularly limited, but it is preferably blended in an amount of 5 to 400% by mass, more preferably 10 to 200% by mass, based on the component (A).

<< (D) 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB) >>
The sealant composition of the present invention preferably further contains (D) 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB) as another component.
The blending ratio of the component (D) is not particularly limited, but it is preferably blended in an amount of 5 to 100% by mass, more preferably 5 to 80% by mass, based on the component (A).

≪Other additives≫
In addition to the above-mentioned components, the sealant composition of the present invention contains, if necessary, a catalyst, a filler, a plasticizer other than the component (C), a colorant such as a pigment and a dye, an antistatic agent, and a flame retardant. , Adhesive-imparting agent, thixotropy-imparting agent, silane coupling agent, dispersant, antioxidant, antistatic agent, water absorber, stabilizer, solvent and the like may be blended.

In the sealing material composition of the present invention, the time (coating time) until a film is formed is preferably in the range of 30 minutes to 240 minutes. With this time, sufficient time for spatula repair and the like can be taken, which is also appropriate as the total construction time.
The sealant composition of the present invention can be further cured by using a catalyst. When a catalyst is used, it is preferably added to the sealant composition immediately before use. Specifically, known metal compounds such as tin, zinc, and bismuth, tertiary amine compounds, imine compounds, imidazole compounds, and the like can be used.

The method for producing the sealing material composition of the present invention is not particularly limited, but preferably, other additives are added to each component as necessary, and the mixture is sufficiently kneaded under reduced pressure or under an inert atmosphere to be uniformly dispersed. It is better to make a composition. The polyurethane-based sealant composition of the present invention can be used in either a one-component type or a two-component type, and especially when used in the one-component type, it is not necessary to mix each component at the time of construction, so that workability is improved. Are better.

Fillers include organic and inorganic fillers of various shapes, such as calcium carbonate (light treatment, heavy), magnesium carbonate, zinc carbonate; carbon black; clay; talc; fumed silica, calcined silica, precipitated silica. , Crushed silica, molten silica; kaolin; diatomaceous soil; zeolite; titanium oxide, quicklime, calcium oxide, iron oxide, zinc oxide, barium oxide, magnesium oxide; aluminum sulfate; vinyl chloride paste resin; glass balloon, silas balloon, saran Inorganic balloons such as balloons, phenol balloons, vinylidene chloride resin balloons, organic balloons and the like; or these fatty acids, resin acids, fatty acid ester-treated products and the like can be used alone or in combination.

Other plasticizers include, for example, dioctyl phthalate (DOP), dibutyl phthalate (DBP), dilauryl phthalate (DLP), butyl benzyl phthalate (BBP), dioctyl adipate, diisononyl phthalate, diisodecyl adipate, diisodecyl phthalate, trioctylphos. Hate, tris (chloroethyl) phthalate, tris (dichloropropyl) phthalate, propylene glycol adipate polyester, butylene glycol adipate polyester, alkyl epoxidate stearate, terminal esterified polyether, epoxidized soybean oil, etc. Alternatively, they can be mixed and used.

Examples of the colorant include organic pigments such as azo pigments and copper phthalocyanine pigments, pigments such as various inorganic pigments, carbon black, titanium white, chromium oxide, red iron oxide and the like. Examples of the stabilizer include hindered phenol-based compounds and triazole-based compounds.

Examples of the antistatic agent generally include ionic compounds such as quaternary ammonium salts and amines, and hydrophilic compounds such as polyethylene glycol and ethylene oxide derivatives.

Examples of the adhesive imparting agent include terpene resin, phenol resin, terpene-phenol resin, rosin resin, xylene resin and the like. Examples of the flame retardant include chloroalkyl phosphate, dimethylmethylphosphonate, bromine, phosphorus compound, ammonium polyphosphate, diethylbishydroxyethylaminophosphate and the like.

Examples of the thixotropy-imparting agent include colloidal silica, fatty acid amide wax, aluminum stearate, surface-treated bentonite, polyethylene short fibers, phenol resin short fibers, Aerosil (manufactured by Nippon Aerosil Co., Ltd.), Disparon (manufactured by Kusumoto Kasei Co., Ltd.) and the like. ..

Examples of the silane coupling agent include amino group-containing silanes such as N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane; mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane; γ- Epoxy group-containing silanes such as glycidoxypropyltrimethoxysilane; vinyl-type unsaturated group-containing silanes such as vinyltrimethoxysilane; isocyanate group-containing silanes such as γ-isocyanuspropyltrimethoxysilane can be mentioned. , These silane coupling agents may be used alone or in combination of two or more.

Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, heptane, octane and cyclohexane, petroleum-based solvents ranging from gasoline to kerosene distillates, ethyl acetate, butyl acetate and the like. Esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ether esters such as cellosolve acetate and butyl cellosolve acetate, and the like, and aromatic solvents are preferable.

Hereinafter, the present invention will be described in more detail with reference to Examples, but it goes without saying that these Examples are illustrated and should not be construed in a limited manner.

(Synthetic Example 1) Preparation of Urethane Prepolymer A 2080 equivalents of propoxylation having 510 parts by mass of 4,4-diphenylmethane diisocyanate (MDI) and Voranol CP6001 (trade name manufactured by Dow Chemical Company, 15% by mass of ethylene oxide chain). A polyether polyol (OH value 27 mgKOH / g) 4185 parts by mass was reacted at 70 ° C. for 7 hours to obtain a urethane prepolymer A having an isocyanate group as a terminal. The terminal NCO group was 1.83% by mass.

(Synthesis Example 2) Preparation of Urethane Prepolymer X 598 parts by mass of 2,4-tolylene diisocyanate, 2600 parts by mass of polyoxypropylene glycol (OH value 55.6 mgKOH / g), and polyoxypropylene triol (OH value 56. 1 mgKOH / g) 1802 parts by mass was reacted at 80 ° C. for 7 hours to obtain a urethane prepolymer X having an isocyanate group as a terminal. The terminal NCO group was 1.89% by mass and the viscosity was 41,000 mPa · s / 25 ° C.

(Synthesis Example 3) Preparation of Urethane Compound To 200 g of polyoxypropylene monool (Actol EH-25, manufactured by Mitsui Chemicals Polyurethane Co., Ltd., OH value 27.2 mgKOH / g), 14.1 g of hexamethylene diisocyanate was added, and the temperature was 80 ° C. The reaction was carried out for 10 hours to obtain a urethane compound. The NCO content of the urethane compound was 0.09%, and the viscosity was 6,400 mPa · s / 25 ° C.

(Example 1)
A sealant composition was prepared as follows with the compositions shown in Table 1. Put (D) TXIB, surface-treated calcium carbonate and heavy calcium carbonate in a 3 liter planetary mixer, knead at room temperature for 15 minutes, and then dehydrate in vacuum while kneading at 100 ° C for 1 hour. It was. Next, (A) urethane prepolymer, (B) biuret body, and (C) urethane compound were added and kneaded at room temperature for 15 minutes to obtain a sealing material composition.

Each compounded substance in Table 1 and the compounding amount thereof are shown by mass.
1. 1. Urethane prepolymer A component (A) obtained in Synthesis Example 1
2. 2. Urethane prepolymer X obtained in Synthesis Example 2
3. 3. Biuret of HDI: Takenate D165N (manufactured by Mitsui Chemicals, Inc.) Ingredient (B)
4. Isocyanurate of HDI: Takenate D170N (manufactured by Mitsui Chemicals, Inc.)
5. Urethane compound component (C) obtained in Synthesis Example 3
6.2,2,4-trimethyl-1,3-pentanediol diisobutyrate (manufactured by Eastman Chemical Japan Co., Ltd.) Ingredient (D)
7: Maruo Calcium Co., Ltd., Calfine 200 (fatty acid-treated calcium carbonate)
8: Made by Maruo Calcium Co., Ltd., Super # 1500 (heavy calcium carbonate)

The following measurements were carried out on the obtained sealing material composition.
1) Storage stability The sealant composition of the present invention was kept warm at 50 ° C., and the viscosities were measured at the initial stage, 1 week and 2 weeks later. The viscosity was measured with a BS type No7 viscometer at a rotation speed of 5 rpm (Pa · s).

2) Drying time to the touch The obtained sealing material composition was filled in a container having a diameter of 50 mm and a depth of 5 mm and left in an atmosphere of 23 ° C. and 50% RH until the sample did not adhere to the fingertips. I checked the time.

3) H-type tensile adhesiveness The sealant composition of the present invention was cured with mortar on both sides as an adherend for 14 days under the condition of 23 ° C. and 50% RH, and then for 14 days under the condition of 30 ° C. and 50% RH. By doing so, an H-type tensile test piece was prepared. With that state as the initial value, an H-type tensile test piece was prepared in which the test piece was immersed in water at 23 ° C. for 7 days for an adhesion test after immersion in water.
JIS A-1439 5.20. In accordance with the tensile adhesiveness test, a tensile test is performed in an atmosphere of 23 ° C. and 50% RH, and the modulus at 50% elongation, the maximum tensile modulus, and the elongation at maximum load are measured, and the state at break. Was visually confirmed.

≪Test items≫
・ Modulus at 50% elongation (50% tensile stress)
・ Maximum tensile modulus (maximum tensile stress)
・ Elongation (elongation at maximum load)
-Observation of fractured state: CF cohesive fracture, AF interface fracture, TCF thin layer aggregate fracture (The fractured state is better in the order of CF>TCF> AF.)

From Table 1, it is clear that the sealant composition of the present invention has good curing rate and storage stability. In addition, good results were obtained for the initial adhesiveness and water resistance.

Claims (2)

A urethane prepolymer which is a reaction product of (A) a polyether polyol having an ethylene oxide chain and a propylene oxide chain and a polyisocyanate compound.
(B) Biuret of diisocyanate,
Sealant composition containing and. The sealant composition according to claim 1, wherein the diisocyanate of (B) is hexamethylene diisocyanate.