JP2006028368A - Moisture-curing type urethane adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture-curing type urethane adhesive composition excellent in storage stability, having long pot life, excellent in a low-temperature curing property and making changeover of adhesive in summer season and winter season unnecessary and being useable all year. <P>SOLUTION: The moisture-curing type urethane adhesive compound comprises (A1) an urethane prepolymer having an isocyanate group and obtained by reacting a polyol with a polyisocyanate, (B) a morpholine compound and (C) an amine compound. The morpholine compound is preferably dimorpholinodiethyl ethers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a moisture curable urethane adhesive composition, and more specifically, it has excellent storage stability, has a long pot life under high temperature and high humidity conditions in summer, and is curable under low temperature and low humidity conditions in winter. In particular, the present invention relates to a moisture-curable urethane adhesive composition that can be suitably used for adhesion between a flooring material and a base material.

  Since polyurethane resins are excellent in various properties such as rubber elasticity, wear resistance and durability, they have been particularly used in recent years as paints, flooring materials, waterproofing materials, adhesives, wall materials, sealing materials and the like. These polyurethane resins are cured by a one-pack type that cures by reacting the terminal isocyanate group of the polyurethane prepolymer with moisture in the air or in the substrate after being applied to the object, and a main agent and polyol containing the polyurethane prepolymer. Are roughly classified into two-component types that are mixed and cured at the time of construction.

  One-pack type polyurethane resin has attracted particular attention in recent years because of its simple construction method. However, since the one-pack type polyurethane resin is cured by reacting with moisture in the air or the base material, there is a problem that the curing time and curability are greatly influenced by temperature and humidity. Therefore, under low temperature and low humidity conditions such as in winter, an adhesive adjusted to cure at low temperature and low humidity by adding a curing catalyst is used. In order to ensure the above, a method using an adhesive without adding a curing catalyst or the like is used.

  However, these methods require switching between the winter adhesive and the summer adhesive from time to time, which is time consuming and has a problem of switching time. The problem is that the adhesive strength is reduced and the pot life is too short, and the curing speed is too slow for the summer adhesive.

  In order to solve these problems, Patent Document 1 blends finely powdered calcium oxide with a terminal isocyanate group-containing urethane prepolymer, and reacts carbon dioxide generated when the isocyanate group and water react with calcium oxide. It is disclosed to prevent the generation of bubbles. However, this method does not solve the problem of pot life, and further, when curing is promoted with a catalyst or the like, carbon dioxide is generated more than the reaction between carbon dioxide and calcium oxide, resulting in bubbles and adhesion. There was a problem that led to a decline in power.

  In addition, Patent Document 2 uses a composition composed of a one-component moisture-curing urethane resin using 2,4′-diphenylmethane diisocyanate and an amine catalyst, and can be applied with an initial adhesive strength. A method for reducing the dependence of time on the construction environment is disclosed. In this method, by using 2,4′-diphenylmethane diisocyanate, it is possible to make the construction environment more curable and capable of sticking than when 4,4′-diphenylmethane diisocyanate is used alone. However, the problem of increase / decrease in the amount of reaction accelerator in winter and summer, that is, the problem of switching between winter construction and summer construction is not solved.

Further, Patent Document 3 provides improved adhesion and fast curability by using a one-component moisture-curing urethane resin using N-methyl-2-pyrrolidone and a tertiary amine-based catalyst using a crude MDI. However, the problem of temperature and humidity in summer and winter has not been solved.
JP 60-188455 A Japanese Patent Laid-Open No. 9-235540 JP-A-11-263962 Japanese Patent Laid-Open No. 2-111765 JP-A-8-245940

  The present invention is a moisture-curing urethane adhesive composition that is excellent in storage stability, has a long working life, is excellent in low-temperature curability, does not require switching of an adhesive in summer and winter, and can be used throughout the year. The purpose is to provide.

  In order to solve the above-mentioned problems, a first aspect of the moisture-curable urethane adhesive composition of the present invention is (A1) a urethane prepolymer having an isocyanate group obtained by reacting a polyol and a polyisocyanate, (B) It contains a morpholine compound and (C) an amine compound.

  The amine compound (C) is preferably at least one selected from the group consisting of tertiary amines and amine polyols.

  A second aspect of the moisture-curable urethane adhesive composition of the present invention comprises (A2) a urethane prepolymer obtained by reacting an amine polyol and a polyisocyanate, and (B) a morpholine compound. To do.

  In the first and second embodiments of the moisture-curable urethane adhesive composition of the present invention, it is preferable that the morpholine compound is dimorphonodiethyl ethers.

  According to the present invention, it has excellent storage stability, has a long pot life under high-temperature and high-humidity conditions in summer, has excellent curability under low-temperature and low-humidity conditions in winter, and has an adhesive in summer and winter. Therefore, it is possible to provide a moisture-curable urethane adhesive composition that can be used year round and can be suitably used for adhesion between a flooring material and a base material.

  Embodiments of the present invention will be described below, but these embodiments are exemplarily shown, and it goes without saying that various modifications can be made without departing from the technical idea of the present invention.

  The first aspect of the moisture-curable urethane adhesive composition of the present invention is (A1) a urethane prepolymer having an isocyanate group obtained by reacting a polyol and a polyisocyanate, (B) a morpholine compound, and (C) an amine. It contains a compound.

  As the urethane prepolymer (A1) having an isocyanate group used in the present invention, a polyurethane prepolymer having a known isocyanate group can be widely used. For example, a polyol having two or more hydroxyl groups (OH) and an isocyanate group ( It is obtained by reacting a polyisocyanate having 2 or more NCO) with an excess of isocyanate groups, that is, with an NCO / OH equivalent ratio of more than 1. The reaction conditions include, for example, an NCO / OH equivalent ratio of 2.0 to 15.0, more preferably 2.0 to 8.0 at a temperature of 70 to 100 ° C. in a nitrogen or dry air stream. Produced by reacting for a time. The normal NCO content of the obtained NCO-containing prepolymer is in the range of 5 to 25% by weight.

  The polyol is not particularly limited, and may be any active hydrogen-containing compound having two or more active hydrogen groups. Generally, polyether polyol, polyester polyol, or amine polyol is preferably used, and particularly polyether polyol. Is preferred. As the polyol, those having a molecular weight of usually 100 to 12000 and 2 to 4 OH groups in one molecule can be preferably used. These polyols may be used alone or in combination of two or more.

  More specifically, for example, as the polyether polyol, one or two kinds of diols such as ethylene glycol, propylene glycol and butylene glycol, triols such as glycerin and trimethylolpropane, and amines such as ammonia and ethylenediamine are used. Examples include polyether polyols such as random or block copolymers obtained by ring-opening polymerization of propylene oxide and / or ethylene oxide in the presence of the above.

  Examples of polyester polyols include polyester polyols such as copolymers obtained by polycondensation of adipic acid, sebacic acid, terephthalic acid, etc. in the presence of ethylene glycol, propylene glycol, 1,4 butanediol, neopentyl glycol, etc. And other low molecular active hydrogen compounds having two or more active hydrogen groups such as bisphenol A and ramester of castor oil.

  The amine polyol can be obtained, for example, by addition reaction of an alkylene oxide with an amine compound, and is preferably a triamine or higher polyamine polyol on average. Examples of the amine compound include ethylamine, butylamine, octylamine, laurylamine, ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, propylenediamine, methylaminomethylamine, methylaminoethylamine, ethylaminoethylamine, 1,2 -Diaminopropane, 1,3-diaminopropane, methylaminopropylamine, bis (3-aminopropyl) ether, 1,3-bis (3-aminopropyl) ethane, 1,4-diaminobutane, laurylaminopropylamine, Examples include aliphatic polyamines such as iminobispropylamine and methyliminobispropylamine, and aromatic polyamines such as metaxylenediamine, which should be used alone or in combination. It can be. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and the like.

  Specific examples of the polyisocyanate include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), naphthalene diisocyanate, hexamethylene diisocyanate (HDI), and lysine methyl ester diisocyanate. Alicyclic polyisocyanates such as aliphatic polyisocyanates, hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, and the like. Among these, MDI is used from the viewpoint of toxicity and price. Is preferred.

  The urethane prepolymer (A1) having an isocyanate group obtained by reacting the polyol and polyisocyanate may be used alone or in combination of two or more. When two or more types are used in combination, the combination is not particularly limited, and prepolymers using different polyols or polyisocyanates, for example, a prepolymer using polypropylene glycol and a prepolymer using amine polyol are used in combination. May be.

  As the morpholine compound (B) used in the present invention, known morpholine compounds can be widely used, and dimorphonodiethyl ethers represented by the following formula (1) are preferable because of excellent storage stability.

[In Formula (1), R < ¹ > -R < ⁸ > is a hydrogen atom or a monovalent substituent each independently, A hydrogen atom or a C1-C3 alkyl group is preferable, and hydrogen or a methyl group is more preferable. ]

  Examples of the dimorphino diethyl ethers include those disclosed in Patent Documents 4 and 5, and specifically, bis (morpholinoethyl) ether, bis (2,6-dimethylmorpholinoethyl) ether. Bis (3,5-dimethylmorpholinoethyl) ether, bis (3,6-dimethylmorpholinoethyl) ether, 4- (3,5-dimethylmorpholino) -4 '-(3,6-dimethylmorpholino) diethyl ether, etc. Is a suitable example.

  The blending ratio of the component (B) is not particularly limited, but it is preferable to use 0.05 to 10.0 parts by weight of the component (B) with respect to 100 parts by weight of the component (A). It is more preferable to use 1 to 5.0 parts by weight. These morpholine compounds (B) can be used alone or in combination of two or more.

  As the amine compound (C) used in the present invention, amine compounds other than the morpholine compound (B) can be widely used, but tertiary amines and amine polyols are preferable. These amine compounds can be used alone or in combination of two or more.

  Examples of the tertiary amine include tripropylamine, triisopropylamine, tributylamine, triisobutylamine, tritertiary butylamine, triamylamine, trihexylamine, trioctylamine, tri-2-ethylhexylamine, methyldi-2- Monoamines such as ethylhexylamine, dibutyl 2-ethylhexylamine, trihexadecylamine, tribenzylamine, and tetramethyl 1,2-diaminoethane, tetramethyl 1,3-diaminopropane, tetramethylhexamethylenediamine, pentamethyldiethylenetriamine, etc. Examples include polyamines. As the amine polyol, the amine polyol described in the description of the isocyanate (A1) can be used in the same manner.

  The blending ratio of the component (C) is not particularly limited, but when a tertiary amine is used as the component (C), the component (C) is added in an amount of 0.05 to 100 parts by weight with respect to 100 parts by weight of the component (A). It is preferable to use 10.0 parts by weight, and it is more preferable to use 0.1 to 3.0 parts by weight. Moreover, when using an amine polyol as (C) component, it is preferable to use 1-50 weight part of (C) component with respect to 100 weight part of (A) component, and it is more preferable to use 1-20 weight part.

  In addition to the above components, the moisture curable urethane adhesive composition of the present invention includes a curing catalyst, an adhesion-imparting agent, a physical property modifier, a filler, a plasticizer, a thixotropic agent, and a dehydrating agent (if necessary). Storage stability improver), tackifier, anti-sagging agent, UV absorber, antioxidant, flame retardant, colorant, radical polymerization initiator, and various solvents such as toluene and alcohol Also good.

  2nd aspect of the moisture hardening type urethane adhesive composition of this invention contains the urethane prepolymer formed by making (A2) amine polyol and polyisocyanate react, and (B) morpholine compound, It is characterized by the above-mentioned. .

  The said component (B) is as having mentioned above in the 1st aspect of the moisture hardening type urethane adhesive composition of this invention. What is necessary is just to carry out similarly to the 1st aspect of the moisture hardening type urethane-adhesive composition of above-described this invention about the mixture ratio of a component (B). The component (A2) is obtained by the reaction of the amine polyol and the polyisocyanate listed in the component (A1) of the first embodiment of the moisture curable urethane adhesive composition of the present invention. In the second embodiment of the present invention, a urethane prepolymer other than the component (A2) may be used in combination with the component (A2). It is the same as that of a 1st aspect also about compounds other than the said component.

  The present invention will be described more specifically with reference to the following examples. However, it is needless to say that these examples are shown by way of illustration and should not be construed in a limited manner.

(Synthesis Example 1)
In a stirrer equipped with a thermometer, 67.7 parts by weight of polypropylene glycol having a molecular weight of 2000 (trade name: Diol-2000, manufactured by Mitsui Takeda Chemical Co., Ltd.) was dehydrated, and then 4,4′-diphenylmethane diisocyanate (MDI) 32. 3 parts by weight was added and reacted at 70 to 90 ° C. for 3 hours under a nitrogen stream to obtain a urethane prepolymer having a terminal isocyanate content of 8.0% by weight.

Example 1
As shown in Table 1, 100 parts by weight of the urethane prepolymer obtained in Synthesis Example 1 was added to 200 parts by weight of dried calcium carbonate, 10 parts by weight of a diluent, 0.3 parts by weight of a morpholine compound, and 0.3 parts of a tertiary amine. Part by weight was added and stirred and mixed at 90 ° C. under a nitrogen stream to obtain a one-part moisture-curable urethane adhesive composition.

In Table 1, the compounding quantity of each compounding substance is shown by a weight part, and * 1- * 7 is as follows.
* 1: Urethane prepolymer obtained in Synthesis Example 1 * 2: SBU isocyanate E21-2 (manufactured by Sumika Bayer Urethane Co., Ltd., urethane prepolymer using amine polyol)
* 3: Bis (morpholinoethyl) ether * 4: 2,4,6-tris (dimethylaminomethyl) phenol (manufactured by Sumitomo Chemical)
* 5: Actcoal EDA200 (Mitsui Takeda Chemical)
* 6: Dried calcium carbonate * 7: DINP (diisononyl phthalate)

Using the obtained adhesive composition, the pot life, storage stability, and low-temperature curability were evaluated as follows. The results are shown in Table 2.
1) Pot life: Measured time to tack free under 23 ° C 50% RH condition.
2) Storage stability: The prepared adhesive composition was filled in a glass bottle, and the viscosity increase rate after being allowed to stand in a 50 ° C. atmosphere for 2 weeks was measured.
3) Low-temperature curability: Plywood was bonded to an adhesive composition stored at 5 ° C. in an atmosphere at 5 ° C., and shear adhesive strength was measured after 3, 6, 8 and 24 hours.

(Examples 2 to 6)
As shown in Table 1, the experiment was performed in the same manner as in Example 1 except that the blending substances and blending ratios were changed. The results are shown in Table 2.

(Conventional examples 1 and 2)
As shown in Table 3, the experiment was performed in the same manner as in Example 1 except that the blending substances and blending ratios were changed. The results are shown in Table 4.

  In Table 3, the compounding quantity of each compounding substance is shown by a weight part, * 1- * 7 is the same as Table 1, * 8 is dibutyltin dilaurate (DBTDL).

(Comparative Examples 1-4)
As shown in Table 3, the experiment was performed in the same manner as in Example 1 except that the blending substances and blending ratios were changed. The results are shown in Table 4.

  As shown in Table 2, the moisture-curable urethane adhesive composition of the present invention has excellent storage stability and has a great effect that it has a long pot life and excellent low-temperature curability.

Claims (4)

(A1) a urethane prepolymer having an isocyanate group obtained by reacting a polyol and a polyisocyanate,
(B) a morpholine compound, and (C) an amine compound,
A moisture-curing urethane adhesive composition comprising: (A2) urethane prepolymer obtained by reacting amine polyol and polyisocyanate, and (B) morpholine compound,
A moisture-curing urethane adhesive composition comprising:   The moisture-curable urethane adhesive composition according to claim 1, wherein the amine compound (C) is at least one selected from the group consisting of a tertiary amine and an amine polyol.   The moisture-curable urethane adhesive composition according to any one of claims 1 to 3, wherein the morpholine compound is dimorphonino diethyl ethers.