JPH04216812A - One-pack moisture-curing polyurethane composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in the balance between storage stability and curability by mixing an adduct obtained by reacting an organic polyhydroxyl compound with CaCl2 and an organic isocyanate compound. CONSTITUTION:An organic polyhydroxyl compound (A) selected from among a polyether polyol, a polyester polyol and other polyols (e.g. polyethylene glycol) is reacted with 0.8-4.0mol, per OH of component A, of CaCl2 (B) to obtain an adduct of component A with component B. This adduct is mixed with an organic polyisocyanate (e.g. diphenylmethane diisocyanate) in an amount to give 0.3-10.0 equivalents of NCO groups per OH of component A and optionally a filler, a solvent, a plasticizer, a thixotropant, a stabilizer, a catalyst, etc., to obtain the title composition.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-curable polyurethane composition having an excellent balance between storage stability and curability during use. More specifically, the present invention relates to a one-component moisture-curable polyurethane composition useful for adhesives, waterproofing materials, sealing materials, lining materials, and the like.

0002

[Prior Art] Conventionally, moisture-curing polyurethane made of organic isocyanate compounds can be used as a one-component type by reacting with moisture in the atmosphere, eliminating the trouble of mixing two components, and Because of its excellent adhesion, it is used in many fields such as adhesives, waterproofing materials, sealing materials, and lining materials.

However, conventional moisture-curable polyurethane resins have the disadvantage that it is difficult to obtain a composition with an excellent balance between resin storage stability and curability during use. That is, if a resin with good storage stability is not subjected to many restrictions on the usage conditions during curing, foaming, cracking, poor curing, etc. may occur, and the desired performance of the cured product may not be obtained. Furthermore, resins with good curing conditions during use often have a short pot life due to increased viscosity and separation of components during storage.

It is common practice to incorporate calcium chloride as a filler into moisture-curable resins having free isocyanate groups. However, with the one-component type, even if many restrictions are placed on the usage conditions during curing, foaming, cracking, poor curing, etc. may occur, and the desired performance of the cured product may not be achieved, especially when used for on-site construction. There are many problems when doing so.

[0005] The method of incorporating an organic polyhydroxyl compound as a crosslinking agent into an organic polyisocyanate compound is generally used in a two-pack type. However, if it is made into a one-component type,
Naturally, the viscosity increases, resulting in a composition that cannot withstand long-term storage.

[0006] The present inventors mixed calcium chloride and an organic polyhydroxyl compound having two or more hydroxyl groups with an organic polyisocyanate compound having two or more free isocyanate groups to create a compound that can withstand storage over time. A patent application was filed for a one-component composition (Patent application No. 2-274
728).

[0007] However, the patent application does not have sufficient properties such as the deliquescent property of calcium chloride, the stability of the adduct of organic polyhydroxyl compound and calcium chloride in the presence of free isocyanate groups, and the foaming suppressing effect during moisture curing.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a one-component moisture-curable composition having free isocyanate groups that maintains good storage stability and curability. be.

[0009]

[Means for Solving the Problems] The present inventors have found that by mixing an organic polyisocyanate compound with an adduct of an organic polyhydroxyl compound and a specific amount of calcium chloride, the curability and storage properties as described above are improved. The present invention was completed by discovering that a one-component moisture-curing polyurethane composition that can be used satisfactorily without problems with stability can be obtained.

That is, the present invention provides calcium chloride (B) 0 for the hydroxyl group of the organic polyhydroxyl compound (A).
．． A one-component moisture-curing polyurethane prepared by mixing an adduct of an organic polyhydroxyl compound (A) and calcium chloride (B), which have been reacted in an amount of 8 to 4.0 mol, with an organic isocyanate compound (C). A composition comprising an organic isocyanate compound (A) and an organic polyhydroxyl compound (B)
It is a one-component moisture-curable polyurethane composition consisting of calcium chloride (C) and a filler (D).

[0011] In the present invention, an organic polyhydroxyl compound having two or more hydroxyl groups is desirable, and it is sufficient that calcium chloride is present in an amount that protects the hydroxyl groups.
Calcium chloride is preferably used in an amount of 0.8 to 4.0 moles, preferably 1.0 to 2.5 moles, based on the hydroxyl group. If it is less than 0.8 mol, storage stability in the organic isocyanate compound will be poor. When the amount exceeds 4.0 mol, a sweating phenomenon is observed in the cured sheet, which is thought to be caused by the deliquescent property of calcium chloride.

The mixing ratio of the adduct of calcium chloride and organic polyhydroxyl compound to the organic isocyanate compound is determined by the ratio of isocyanate groups to hydroxyl groups. Isocyanate group is 0.3 to hydroxyl group
equivalent to 10.0 equivalent, preferably 1.0 equivalent to 5
．． 0 equivalent is better. When the amount is less than 0.3 equivalent, a sweating phenomenon is observed in the cured sheet, which is thought to be caused by the deliquescent property of calcium chloride. If the amount exceeds 10.0 equivalents, the anti-foaming curing effect of the adduct of calcium chloride and the organic polyhydroxyl compound will be weakened, making it easier to foam during curing.

Calcium chloride is mixed in the composition as an adduct with the organic polyhydroxyl compound, and the weight of calcium chloride alone ranges from 0.05% to 15.0%, preferably from 0.1% to 7.0%. 0% is good. When the amount is too low, foaming tends to occur during curing, and when the amount is too high, a sweating phenomenon is observed on the cured product sheet.

It has been known for 100 years that calcium chloride forms adducts with up to 4 moles of ethyl alcohol. It is also well known that such adducts dissociate in the presence of water and the alcohol can be purified by distillation. However, it is surprising that such adducts remain stable in the coexistence of free isocyanate, and similar stability was confirmed for adducts with glycols.

When a filler is mixed into the composition, the sweating phenomenon of the cured sheet tends to be reduced, but it can be used within the above range, and after storage over time, it can be used in the air in the presence of moisture. When applied, it exhibits good curability and the molded sheet has satisfactory performance.

The organic polyisocyanate compound of the present invention is a compound having two or more isocyanate groups,
These include a prepolymer prepared by a conventional method using an organic polyisocyanate and an organic polyhydroxyl compound in an excess amount of isocyanate, and the organic polyisocyanate itself.

As the organic polyisocyanate, 2,4
-Tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, partially carbodiimidized diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, toridine diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylene Aromatic diisocyanates such as diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate,
Examples include one or a mixture of two or more aliphatic diisocyanates and alicyclic diisocyanates.

The organic polyhydroxyl compound of the present invention includes polyether polyol, polyester polyol,
Other polyols and mixed polyols thereof. The polyether polyol includes one or more polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, glucose, sorbitol, and sucrose, plus propylene oxide, ethylene oxide, and butylene. Examples include polyols obtained by adding one or more of oxide, styrene oxide, etc., and polyoxytetramethylene polyols.

[0019] Polyester polyols include ethylene glycol, propylene glycol, butanediol,
One or more of pentanediol, hexanediol, cyclohexanedimethanol, glycerin, trimethylolpropane or other low molecular weight polyols and glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid, dimer acid,
Examples include condensation polymers with hydrogenated dimer acid or one or more types of other low-molecular dicarboxylic acids and oligomer acids, and ring-opening polymers such as propiolactone, caprolactone, and valerolactone.

Other polyols include polycarbonate polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, acrylic polyols, and the like. Also included are low-molecular polyols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol glycerin, trimethylolpropane, glucose, sorbitol, and sucrose.

The hydroxyl group of the organic polyhydroxyl compound of the present invention is preferably a primary hydroxyl group.
The calcium chloride of the present invention is preferably anhydrous, but
Mono, 2, 4, 6 hydrates can also be used.

[0022] The adduct of calcium chloride and an organic polyhydroxyl compound is prepared by mixing at room temperature, but it may also be heated. When using anhydrous calcium chloride, there is no particular need for dehydration, but in order to mix it with an organic polyisocyanate compound and store it stably as a one-component type, it is better to perform dehydration under reduced pressure. In the case of a low-molecular organic polyhydroxyl compound, it becomes solid. In this case, the dehydration operation may be performed by mixing an inert solvent, plasticizer, process oil, etc. with the isocyanate group.

Adducts of calcium chloride and organic polyhydroxyl compounds can also be prepared in moisture-curing prepolymers having free isocyanate groups. Anhydrous calcium chloride may be mixed in advance with the prepolymer, and a predetermined amount of the organic polyhydroxyl compound may be mixed therein.

[0024] Examples of the filler include carbon black, calcium carbonate, talc, clay, silica, titanium oxide, gypsum, and diatomaceous earth. In the present invention, other appropriate solvents, plasticizers, thixotropic agents, stabilizers, catalysts, etc. may be added and used.

Examples of the solvent include toluene, xylene, turpentine, ethyl acetate, butyl acetate, methyl ethyl ketone, and cellosolve acetate. Process oils are high-boiling point oils obtained through petroleum refining.

Examples of the plasticizer include dibutyl phthalate and dioctyl phthalate. Examples of the thixotropic agent include polyvinyl chloride powder, finely powdered silica, and bentonite.

[0027] Examples of the stabilizer include antioxidants and ultraviolet absorbers. Examples of the catalyst include tertiary amines and organometallic compounds.

[0028]

EXAMPLES Next, Examples will be shown, but the present invention is not limited to these Examples. "Part", "%" in a sentence
are based on weight unless otherwise specified. Reference Example Method for Synthesizing Isocyanate Prepolymer 74 parts of diphenylmethane diisocyanate and 80 parts of xylene were added to 646 parts of polyoxyethylene propylene triol (hydroxyl value = 24), and the reaction was carried out at 80°C. Content = 1
．． An isocyanate prepolymer having a viscosity of 65% and a viscosity of 200 (glass temperature, 25 DEG C.) was obtained. This prepolymer is referred to as prepolymer A. Examples 1-3 and Comparative Examples 1-2 Table 1
Polyethylene glycol molecular weight 400 (hereinafter referred to as P
(abbreviated as EG-400) and calcium chloride (hereinafter referred to as CaC)
12) was dehydrated under reduced pressure for 2 hours at 100°C and 5 mmHg, and added to prepolymer A.
Storage stability by accelerated storage test at 50°C for 14 days,
The sheet was coated on a glass plate to a coating thickness of 2 mm, and the appearance of the sheet after curing was evaluated.

In these Examples and Comparative Examples, the effect of masking the hydroxyl groups in polyethylene glycol 400 was investigated when calcium chloride was varied with respect to the hydroxyl groups. The results of this experiment are shown in Table 1.

[0030]

[Table 1]

Examples 4, 5 to 7 and Comparative Examples 3 to 4 Polyethylene glycol 400 and calcium chloride were dehydrated under reduced pressure in advance in dioctyl phthalate (hereinafter abbreviated as DOP) under the above conditions at the ratios shown in Table 2. Prepolymer
The appearance of the sheet after curing was evaluated in the same manner as above.

In these Examples and Comparative Examples, the effect of the reaction ratio of polyethylene glycol 400 and prepolymer A was investigated. The results of this experiment are shown in Table 2.

[0033]

[Table 2]

Examples 4, 8 and Comparative Example 5 Pre-dehydrated polyethylene glycol 400 and polypropylene glycol molecular weight 400 (hereinafter abbreviated as PPG-400) were prepared in the proportions shown in Example 4, Example 8 and Comparative Example 5. ) was mixed with calcium chloride in dehydrated dioctyl phthalate,
The mixture with Prepolymer A was evaluated 30 minutes and 120 minutes after the start of mixing.

In these Examples and Comparative Examples, the masking effect due to the difference between the primary hydroxyl groups of polyethylene glycol 400 and the secondary hydroxyl groups of polypropylene glycol 400 was investigated. The results of these experiments are shown in Table 3.

[0036]

[Table 3]

Example 9 In Example 9, 650 parts of pre-dried calcium carbonate and titanium oxide were added to the weight part of the formulation of Example 3.
100 parts of carbon black and 5 parts of carbon black were mixed to form a compound. It was applied onto a glass plate to a coating thickness of 2 mm and cured in air. When the appearance of the sheet after curing was evaluated, there was no sweating phenomenon compared to the results of Example 3. The cured sheet was measured according to JIS A-6021. Hardness = 30, tensile strength = 14.2Kg/
cm2, tear strength = 6.3Kg/cm, elongation = 540%
It is.

[0038]

Effects of the Invention The moisture-curable polyurethane composition of the present invention has excellent mechanical properties and durability after curing, and is therefore useful for adhesives, waterproofing agents, sealing materials, lining materials, and the like.

Claims (9)

[Claims] Claim 1: Calcium chloride (B) is 0.8 to 4.0 relative to the hydroxyl group of the organic polyhydroxyl compound (A).
The organic polyhydroxyl compound (A
) and calcium chloride (B), and an organic isocyanate compound (C). Claim 2: Comprising an organic isocyanate compound (C), an organic polyhydroxyl compound (A), and calcium chloride (B), wherein the calcium chloride (B) is 0.05 to 15.0% by weight based on the polyurethane composition. A one-component moisture-curable polyurethane composition, characterized in that: 3. Comprised of an organic polyhydroxyl compound (A), calcium chloride (B), and an organic isocyanate compound (C), wherein the hydroxyl group of the organic polyhydroxyl compound (A) is replaced by the isocyanate group of the organic isocyanate compound (C). A one-component moisture-curable polyurethane composition having an equivalent weight of 0.3 to 10.0. 4. The one-component moisture-curable polyurethane composition according to claim 1, wherein the hydroxyl group of the organic polyhydroxyl compound (A) is a primary hydroxyl group. 5. A one-component moisture-curable polyurethane composition comprising an organic polyhydroxyl compound (A), calcium chloride (B), an organic isocyanate compound (C), and a filler (D). [Claim 6] Calcium chloride (B) is 0.8 to 4.0 relative to the hydroxyl group of the organic polyhydroxyl compound (A).
6. The one-component moisture-curable polyurethane composition according to claim 5, wherein the moles are reacted in advance. 7. The one-component moisture-curable polyurethane composition according to claim 5, wherein the calcium chloride (B) is 0.05 to 15.0% by weight based on the polyurethane composition. 8. The liquid composition according to claim 5, wherein the equivalent weight of the isocyanate group of the organic isocyanate compound (C) to the hydroxyl group of the organic polyhydroxyl compound (A) is 0.3 to 10.0. type moisture-curable polyurethane composition. 9. The one-component moisture-curable polyurethane composition according to claim 5, wherein the hydroxyl group of the organic polyhydroxyl compound (A) is a primary hydroxyl group.