JPH09255757A - Polyurethane one-pack curable composition - Google Patents

Abstract

(57) Abstract: The present invention provides curability, hardness, tensile strength, elongation,
A polyurethane one-pack curable composition having excellent non-foaming property is intended. SOLUTION: (A) (A-1) molecular weight of 1,000 per hydroxyl group
To 12,000, a urethane prepolymer having an isocyanate group at the molecular end consisting of a polyoxyalkylene polyol having an unsaturated bond amount of 0.04 meq / g or less and (A-2) polyisocyanate, and (B) at least an oxazolidine ring. A polyurethane one-part curable composition comprising a reaction product or a mixture with one compound.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a curable material obtained by reacting or mixing a compound having an oxazolidine ring, which is used as a sealing material, a wall material, a waterproof material, a paint, or an adhesive for construction or vehicles. , A one-component polyurethane curable composition having excellent hardness, tensile strength and elongation.

[0002]

2. Description of the Related Art A one-component urethane resin is excellent in various properties such as rubber elasticity, abrasion resistance and durability and is used as a sealing material, a wall material, a waterproof material, a paint or an adhesive.

Such a urethane resin is a one-pack type in which a polyurethane prepolymer having a terminal isocyanate group is cured by water in the atmosphere after construction, and a curing agent containing a main agent containing a polyurethane prepolymer having a terminal isocyanate group and a polyol chain. Agents are roughly divided into two-component type which mixes and cures during construction, but the former one-component type polyurethane has attracted attention in recent years and has come to be used experimentally due to its simple construction method. It was

This one-component polyurethane is called moisture-curable polyurethane, and the most common one is a method of reacting polyisocyanate with moisture (moisture). In this method, the addition of isocyanate and moisture causes There is a problem that carbon dioxide gas is generated and the cured product foams. A compound having an oxazolidine ring is known as a one-liquefiable curing agent component.

The cured product of the polyurethane resin composition as described above is required to have properties of high elongation and low modulus, but when cured, it should be cured promptly after application and have less tack. Therefore, in order to obtain a polyurethane cured product having a high elongation and a low modulus, a polyoxyalkylene polyol having a relatively high molecular weight of 2 to 4 functional groups is used. Particularly when a large amount of bifunctional polyoxyalkylene glycol is used, the curing time becomes long, the tack of the cured product remains forever, and it becomes impossible to maintain satisfactory performance.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a polyurethane one-part curable composition which is excellent in curability, hardness, tensile strength, elongation and non-foaming property.

[0007]

Means for Solving the Problems As a result of intensive studies on polyols, the present inventors have found that a urethane prepolymer having an isocyanate group at the molecular end obtained by reacting a specific polyol with a polyisocyanate has at least one oxazolidine ring. The inventors have found that the above-mentioned problems can be solved by reacting or mixing the compounds to form one liquid, and have completed the present invention.

That is, according to the present invention, the molecular weight per (A) (A-1) hydroxyl group is 1,000 to 12,000 and the amount of unsaturated bond is 0.0
With a polyoxyalkylene polyol of 4 meq / g or less
(A-2) a urethane prepolymer having an isocyanate group at the molecular end consisting of polyisocyanate, and (B) consisting of a reaction product or a mixture of a compound having at least one oxazolidine ring, more preferably latent generated from oxazolidine The ratio of isocyanate groups to active hydrogen (the sum of latent amino groups and latent hydroxyl groups), the equivalent ratio of latent active hydrogen ((A) / (B)) of isocyanate / oxazolidine is 0.4 to 4.0. And preferably a polyoxyalkylene polyol having an unsaturated bond amount of 0.003 to 0.04 meq / g is used to provide a one-part polyurethane curable composition.

The invention will be described in detail below.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The polyoxyalkylene polyol (A-1) of the present invention is obtained by addition-polymerizing an alkylene oxide with a polyhydric alcohol in the presence of a catalyst.
When the alkylene oxide is propylene oxide,
As the molecular weight increases, the amount of unsaturated bonds increases and monool is produced. With an alkaline catalyst such as potassium hydroxide,
Since the molecular weight per hydroxyl group is about 1,000 and the unsaturated bond amount is 0.04 meq / g,
It is difficult to obtain a polyoxyalkylene polyol exceeding 000. The polyoxyalkylene polyol having an unsaturated bond amount of 0.04 meq / g or less preferably has a molecular weight of 1 per hydroxyl group obtained in the presence of a catalyst such as a metal porphyrin, a cesium compound and a complex metal cyanide complex.
000 to 12,000 polyoxyalkylene polyol. As such a polyoxyalkylene polyol, Japanese Patent Publication (Kokoku) No.
Those manufactured in accordance with Japanese Patent Publication No. 551-551 are suitable for use in the present invention.

In the present invention, a polyoxyalkylene polyol polymerized by an alkali catalyst such as potassium hydroxide can be used in combination, but a polyol having a low unsaturated bond amount is mixed to obtain a total unsaturated bond amount of 0. It may be adjusted to 0.04 meq / g or less. Especially when a bifunctional polyol is used to secure the elongation of the cured product, 0.04 m
A polyoxyalkylene glycol of eq / g or less is suitable.

As the polyoxyalkylene polyol (A-1), ethylene glycol, diethylene glycol,
One or more polyhydric alcohols such as propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, glucose, sorbitol and sucrose, and one or two species such as propylene oxide, ethylene oxide, butylene oxide and styrene oxide. Examples include polyols and polyoxytetramethylene polyols obtained by adding the above. Polyols that can be used in combination include polyester polyols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, trimethylolpropane, and one or more other low molecular weight polyols and glutar. Acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid,
Examples thereof include condensation polymers with dimer acid, hydrogenated dimer acid or other low molecular weight dicarboxylic acid or one or more kinds of oligomeric acids, and ring-opening polymers such as propiolactone, caprolactone and valerolactone. Other polyols that can be used in combination include polycarbonate polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, acrylic polyol and the like. Also, ethylene glycol, diethylene glycol,
Low molecular weight polyols such as propylene glycol, dipropylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol glycerin, trimethylolpropane, glucose, sorbitol and sucrose are also included.

The polyurethane prepolymer (A) having an isocyanate group at the terminal used in the present invention is a compound having two or more isocyanate groups, and comprises a polyisocyanate (A-2) and a polyol (A-1). It is a prepolymer prepared by a conventional method in the presence of excess polyisocyanate, or further contains polyisocyanate itself. In the preparation of the polyurethane prepolymer, the isocyanate group of polyisocyanate is preferably prepared in a usual manner in a ratio of 1.2 to 20 with respect to one hydroxyl group of various polyols, and it is natural that polyisocyanate can be mixed and used. .

As the polyisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, partially carbodiimidated diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, tolidine diisocyanate, naphthalene diisocyanate, Phenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, aromatic diisocyanates such as cyclohexane diisocyanate,
Examples thereof include aliphatic diisocyanate and alicyclic diisocyanate, or a mixture of two or more kinds.

As the one-liquefying curing agent component of the polyurethane composition, there are known a calcium chloride hydroxyl group-protected compound, an aldimine compound, an enamine compound and a compound having an oxazolidine ring, which accelerates curing of the polyurethane composition. For this purpose, an aldimine compound, an enamine compound, or a compound having an oxazolidine ring, which dissociates and forms a primary and secondary amino group with moisture, is suitable. The oxazolidine ring is suitable for the case where a secondary amino group and a hydroxyl group are simultaneously generated and reticulated during curing, but there is a drawback that the oxazolidine ring lacks storage stability in the presence of a free isothiocyanate group. However, even in the case of an oxazoline compound, one having a carbon number of the side chain at the 2-position of the oxazolidine ring, preferably 3 or more, has storage stability for several months and is practically preferable.

The ratio of the isocyanate group to the latent active hydrogen (sum of latent amino group and latent hydroxyl group) generated from oxazolidine is preferably the equivalent ratio of isocyanate / latent active hydrogen ((A) / (B)) of oxazolidine. 0.4
˜4.0, more preferably 0.5 to 2.0. 0.
When it is less than 4, the storage stability of the composition becomes short. 4.0
If the amount is larger, foaming tends to occur during curing.

The compound (B) having an oxazolidine ring is
A compound synthesized by a dehydration reaction between an alkanolamine having a primary and secondary amino group and a 2-hydroxyalkyl group (alkyl chain: having 2 or more carbon atoms) and an aldehyde or a ketone is preferable.

The alkanolamines include ethanolamine, diethanolamine, isopropanolamine, diisopropanolamine, isobutanolamine, diisobutanolamine, hydroxyethylaminomethyl alcohol, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine. , Bis (aminomethyl) cyclohexane, xylylenediamine, dicyclohexyldiamine, isophoronediamine, isopropylidenebis (aminocyclohexane), methylenebis (aminocyclohexane), polymethylenepolyamine, diaminotoluene, phenylenediamine and the like. Compound having secondary amino-2-hydroxyl group substituted with hydroxyethyl group It is.

Examples of aldehydes or ketones include butyraldehyde, trimethylacetaldehyde, triethylacetaldehyde, valeroaldehyde, furfural, benzaldehyde, methylethylketone, cyclohexanone, trimethylcyclohexanone, acetophenone, anisaldehyde, hexanal, octanal,
Examples include decanal and citral.

The compound having at least one oxazolidine ring includes a compound obtained by reacting 3- (2-hydroxyethyl) -oxazolidine with the aforementioned polyisocyanate, an ester of polycarboxylic acid, and a compound bonded with a carbonate group. Be done. As the polycarboxylic acid, oxalic acid, malonic acid, succinic acid, methylmalonic acid, isosuccinic acid,
Glutaric acid, adipic acid, itaconic acid, maleic acid, fumaric acid, phthalic acid, trimellitic acid, pyromellitic acid,
Butyltetracarboxylic acid, azelaic acid, nonanedicarboxylic acid and the like. The bond of the carbonate group is 3- (2
-Hydroxyethyl) -oxazolidine and diethyl carbonate, dimethyl carbonate, diphenyl carbonate, etc. are introduced by deethanoling, demethanoling, and dephenoling, respectively.

In the present invention, when the hydroxyl group of the compound having at least one oxazoline ring is reacted with the urethane prepolymer having an isocyanate group at the molecular end, the NCO / OH equivalent ratio at that time is preferably 1 to 10 /. 1 and a mixture of the urethane prepolymer (A) and the compound (B) having at least one oxazolidine ring, the compound is
(B) also includes a compound reacted with an isocyanate compound. At this time, when the oxazolidine compound (B) is reacted with or mixed with the polyurethane prepolymer (A) having an isocyanate group, the amount of unsaturated bonds as the polyol of the polyurethane prepolymer is 0.04 me.
The molecular weight per hydroxyl group of q / g or less is 1,000 to 1.
The effect of the present invention cannot be obtained unless 2,000 polyoxyalkylene polyol is used.

The polyurethane one-pack curable composition used in the present invention comprises one or more selected from the group consisting of inorganic acids, organic acids and their anhydrides, esters and acidic salts. Cure is accelerated. For example, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, silicic acid, aluminic acid, perchloric acid,
Formic acid, acetic acid, propionic acid, caproic acid, oxalic acid, succinic acid, adipic acid, maleic acid, phthalic acid, etc., or their anhydrides, esters, acid salts and the like can be mentioned. Of these, phosphoric acid, phosphoric acid ester, acidic phosphoric acid ester, acetic anhydride and alumina silicate are particularly preferable as the moisture curing accelerator.

The polyurethane one-part curable composition of the present invention may optionally further contain a plasticizer, a stabilizer, an inorganic filler or a catalyst.

Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate and the like. Examples of stabilizers include antioxidants and ultraviolet absorbers. Examples of the inorganic filler include calcium carbonate, titanium oxide, calcium oxide, calcium oxide, talc,
Examples thereof include clay, aluminum sulfate, vinyl chloride paste resin and the like. These may be used alone or in combination of one or more, and surface-treated ones may be appropriately used.

[0025]

EXAMPLES Examples will be shown and specifically described below, but the present invention is not limited thereto.

1. <Synthesis of Polyoxyalkylene Polyol> Polyol A: Polyoxypropylene glycol using zinc hexacyanocobaltate diglyme complex catalyst Molecular weight 3,000, unsaturated bond amount = 0.016 meq / g

Polyol B: Polyoxypropylene triol using zinc hexacyanocobaltate diglyme complex catalyst Molecular weight 5,000, unsaturated bond amount = 0.022
meq / g

Polyol C: Polyoxypropylene triol using zinc hexacyanocobaltate diglyme complex catalyst Molecular weight 10,000 Unsaturated bond amount = 0.033
meq / g

Polyol D: Polyoxypropylene glycol with potassium hydroxide catalyst, molecular weight 3,000
0, unsaturated bond amount = 0.058 meq / g.

Polyol E: Polyoxypropylene triol molecular weight 5,000 using potassium hydroxide catalyst
0, unsaturated bond amount = 0.076 meq / g.

Polyol F: polyoxypropylene glycol, molecular weight 500 unsaturated bond amount = 0.006 meq
/ G

2. <Synthesis of Polyurethane Prepolymer> Next, regarding the above polyols A, B, C, D, and E,
Tolylene diisocyanate (2,4 / 2,6 isomer ratio =
80/20) and NCO / OH ratio = 2.2 molar ratio, 90
The reaction was carried out for 5 hours at ℃, urethane prepolymer A,
B, C, D and E were synthesized.

Urethane Prepolymer A:% Isocyanate = 2.8

Urethane Prepolymer B: Isocyanate% = 2.5

Urethane Prepolymer C: Isocyanate% = 1.35

Urethane Prepolymer D: Isocyanate% = 2.8

Urethane Prepolymer E: Isocyanate% = 2.6

Urethane Prepolymer F: Isocyanate% = 10.8

3. Synthesis of oxazolidine 3-1) Synthesis of 2-isopropyl-3- (2-hydroxyethyl) -1,3 oxazolidine

1.2 mol of isobutyraldehyde was added dropwise to 1 mol of diethanolamine and reacted for 5 hours while refluxing. A fraction of 89 to 92 ° C was collected at 7 mmHg. The title compound with a purity of 99% was obtained with a yield of 85%.

The following bisoxazolidine compound was prepared using this compound.

Oxazolidine A: 2-isopropyl-3 equimolar to the isocyanate group of urethane prepolymer A
-(2-hydroxyethyl) -1,3 compound reacted with oxazolidine

Oxazolidine D: 2-isopropyl-3 in equimolar amount to the isocyanate group of urethane prepolymer D
-(2-hydroxyethyl) -1,3 compound reacted with oxazolidine

Oxazolidine F: 2-isopropyl-3 equimolar to the isocyanate group of urethane prepolymer F
-(2-hydroxyethyl) -1,3 compound reacted with oxazolidine

Oxazolidine G: Compound obtained by reacting 1 mol of hexamethylene diisocyanate with 2 mol of 2-isopropyl-3- (2-hydroxyethyl) -1,3 oxazolidine.

Example 1 100 parts by weight of calcium carbonate, 12 parts by weight of titanium oxide, 18 parts by weight of dioctyl phthalate and 0.1 part by weight of carbon were mixed in a planetary mixer and kneaded at 100 ° C. for 1 hour. It was dehydrated under reduced pressure.
Next, 80 parts by weight of urethane prepolymer A, 20 parts by weight of urethane prepolymer B, 8 parts by weight of oxazolidine G, and 0.5 part of propionic acid were kneaded at room temperature for 1 hour. Furthermore, 5 parts by weight of xylene was charged and stirred,
A polyurethane one-pack curable composition was obtained. The calculated average value of the unsaturated bond amount of the polyol used in this composition is 0.01
It is 7 meq / g. This composition was applied to a glass plate in a thickness of 2 mm, and the curability was measured in tack free time. 2.5 hours. The physical properties of the cured sheet were measured by JIS-K6301 after curing for 4 weeks.

Hardness (Shore A) = 55, Tensile strength (K
g / ccm ² ) = 40 and elongation (%) = 550.

(Comparative Example 1) The parts are the same except that D was used instead of the urethane prepolymer A and E was used instead of the urethane prepolymer B in Example 1. The calculated average value of the unsaturated bond amount of the polyol used in this composition is 0.0
It is 62 meq / g.

The procedure is the same as in Example 1 except that 40 parts by weight of the urethane prepolymer A, 25 parts by weight of the urethane prepolymer B, 30 parts by weight of oxazolidine A, and 5 parts by weight of oxazolidine F are replaced by E. The calculated average value of the unsaturated bond of the polyol used in this composition is 0.017 m.
eq / g.

(Comparative Example 2) The parts are the same as in Example 2 except that D was used instead of the urethane prepolymer A, E was used instead of the urethane prepolymer B, and D was used instead of the oxazolidine A. The calculated average value of the unsaturated bond amount of the polyol used in this composition is 0.062 meq / g.

Example 3 The same as Example 1 except that 20 parts by weight of urethane prepolymer A, 40 parts by weight of urethane prepolymer C, and 35 parts by weight of oxazolidine A were used. The calculated average value of the unsaturated bond amount of the polyol used in this composition is 0.023 meq / g.

Comparative Example 3 D was used instead of the urethane prepolymer A of Example 1 and D was used instead of oxazolidine A. The weight part is also the same. The calculated average value of the unsaturated bond content of the polyol used in this composition is 0.045 meq.
/ G.

Table 1 shows Examples 1 to 3 and Comparative Examples 1 to 3. Since each of them contains an oxazolidine compound,
There was no foaming.

[0054]

[Table 1] Table 1

[0055]

INDUSTRIAL APPLICABILITY According to the present invention, by using a specific polyoxyalkylene glycol containing an oxazolidine compound, a polyurethane one-pack curable composition excellent in curability, hardness, tensile strength, elongation and non-foaming property can be obtained. Thus, the curing of the one-component polyurethane composition and the reliability of the cured product are improved.

Claims (3)

[Claims] 1. A molecular weight of (A) (A-1) hydroxyl group is 100
A urethane prepolymer having an isocyanate group at the molecular end consisting of a polyoxyalkylene polyol of 0 to 12,000 and an unsaturated bond amount of 0.04 meq / g or less and (A-2) polyisocyanate, and (B) an oxazolidine ring A one-component polyurethane curable composition comprising a reaction product or a mixture with at least one compound. 2. The ratio of the isocyanate group to the latent active hydrogen (the sum of the latent amino group and the latent hydroxyl group) generated from oxazolidine is the equivalent ratio of the latent active hydrogen ((A) / (B)) of isocyanate / oxazolidine, 0.4-4.0
The one-component polyurethane curable composition according to claim 1, wherein 3. The one-component polyurethane curable composition according to claim 1, wherein the polyoxyalkylene polyol has an unsaturated bond amount of 0.003 to 0.04 meq / g.