JPH07196913A - Moisture-setting urethane sealant composition - Google Patents

Abstract

PURPOSE:To obtain a moisture-setting urethane sealant composition capable of manifesting the initial strength even before curing with moisture and excellent in durability. CONSTITUTION:This moisture-setting urethane sealant composition contains (A) a urethane prepolymer synthesized by reacting a mixture of a polyether triol of 1000 to 7000 number-average molecular weight and a polyether diol with a diisocyanate compound in an equivalent ratio of NCO/OH=1.1 to 2.5 and (B) a polyurethane compound synthesized by reacting a polyether polyol having 500 to 3000 number-average molecular weight or a polyester polyol having 500 to 6000 number-average molecular weight with a polyisocyanate compound in an equivalent ratio of NCO/OH=1.1 to 2.5 and subsequently further reacting a 1 to 22C monoalcohol therewith in an equivalent ratio of NCO/OH =1.1 to 5.0. The polyurethane compound (B) is contained in an amount of 1 to 25 pts.wt. based on 100 pts.wt. urethane prepolymer (A).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt type moisture-curable urethane sealant composition, and more particularly, to an automobile that exhibits sufficient initial strength before moisture-curing and does not deteriorate in adhesiveness for a long time after bonding. The present invention relates to a moisture-curable urethane sealant composition suitable for bonding window glass and the like.

[0002]

2. Description of the Related Art Conventionally, a polymer composition called a reactive hot melt has been known, but this composition is used in a heated and melted state and expresses initial strength by solidification accompanying a decrease in temperature. The final physical properties are exhibited by the curing reaction.

As the reactive hot melt, a moisture containing a polyether polyol-based urethane prepolymer as a main component, or a urethane prepolymer whose raw material polyol component is a combination system of polyester polyol and polyether polyol is used. Curable hot-melt type sealing material (JP-A-02-32189), or a polyether polyol-based urethane prepolymer having a relatively low molecular weight and a glass transition temperature higher than room temperature, and a relatively high molecular weight and room temperature. Known is a fast-curing hot-melt polyurethane composition (Japanese Patent Laid-Open No. 02-182774) which comprises a mixture with a urethane prepolymer having a lower glass transition temperature.

Reactive hot melts having such properties are used in various fields, and are particularly useful as a sealant for attaching window glasses to vehicle bodies in the automobile industry. The performance required for this window glass mounting sealant is that it does not drip when applied to the adherend, sufficient initial strength by cooling and solidification (adhesive strength that can hold the window glass in a short time after coating). Expressing
It has excellent durability and the like.

[0005]

Among the above, with respect to the initial strength, it is required to show sufficient adhesive strength in about 10 minutes in order to shorten the manufacturing time. However, in the conventional moisture-curable urethane sealant for automobile window glass,
After applying the sealant and mounting the glass, there is no rise in adhesive strength until the sealant cures,
For this reason, the glass sometimes slips or floats during the assembly of the automobile, and the correction must be made each time. It was also necessary to use a jig in order to prevent such displacement and floating.

Therefore, the inventors of the present invention have proposed in Japanese Patent Application No.
50912, the terminal NCO of polyester polyol / polyether polyol and polyisocyanate
The above problem is solved by using a polyurethane compound in which the terminal isocyanate group (NCO) of the prepolymer is blocked with monoalcohol. However, such terminal N
When the adhesiveness of the CO-blocked polyurethane compound was examined by an exposure test in the normal state and outdoors, it was found that there was no problem in the normal state, but the adhesiveness was decreased in the long-term outdoor exposure test.

[0007]

Therefore, the present inventors have
The present invention has been completed in order to solve the above problems. INDUSTRIAL APPLICABILITY The present invention is a reactive hot melt particularly suitable for adhesion of window glass of automobiles, capable of exhibiting initial strength even before moisture curing, and durable moisture curability that does not decrease adhesiveness for a long time after adhesion. It is intended to provide a urethane sealant composition.

The present invention has a number average molecular weight of 1,000 to 7,
Urethane prepolymer (A) obtained by reacting a mixture of 000 polyether triols and polyether diols with a diisocyanate compound at an isocyanate group / hydroxyl group equivalent ratio of 1.1 to 2.5, A polyether polyol having a number average molecular weight of 500 to 3,000 or a polyester polyol having a number average molecular weight of 500 to 6,000 and a polyisocyanate compound are used in an amount ratio such that the equivalent ratio of isocyanate group / hydroxyl group is 1.1 to 2.5. After the reaction, the polyurethane compound (B) further contains a polyurethane compound (B) obtained by reacting a monoalcohol having 1 to 22 carbon atoms at an isocyanate group / hydroxyl group equivalent ratio of 1.1 to 5.0. The moisture content is 1 to 25 parts by weight with respect to 100 parts by weight of the urethane prepolymer (A). A reduction urethane sealant composition.

The present invention will be described in detail below. The urethane prepolymer (A) used in the present invention comprises a mixture of a polyether triol having a number average molecular weight of 1,000 to 7,000 and a polyether diol, a polyisocyanate compound, and an isocyanate group / hydroxyl group (hereinafter referred to as NCO).
/ OH) at an equivalence ratio of 1.1 to 2.5.

Polyethertriol which is one of the raw materials for producing the urethane prepolymer (A) is, for example, one or two or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide and tetrahydrofuran. A product obtained by addition-polymerizing a compound having active hydrogen. Here, examples of the compound having three active hydrogens include triols, triamines, alkanolamines, and trivalent phenols. Examples of triols include glycerin, hexanetriol, and trimethylolpropane, examples of alkanolamines include triethanolamine, and examples of trivalent phenols include pyrogallol, phloroglucin, and oxyhydroquinones. Examples of the polyether diol include ethylene glycol, propylene glycol, 1,4-butane diol, hydrobenzoin, benzpinacol, cyclopentane 1,2-diol, cyclohexane 1,4-diol, and the like, diamines include ethylene diamine,
Hexamethylenediamine, o-phenylenediamine, etc., alkanolamines, ethanolamine, propanolamine, etc., and dihydric phenols, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, etc. Is mentioned.

In producing the urethane prepolymer (A), polyether triols and polyether diols having a number average molecular weight of 1,000 to 7,000 are used. The number average molecular weight of the polyether triol and polyether diol used in the production of the urethane prepolymer (A) is set within this range. When the number average molecular weight of less than 1,000 is used, the glass transition temperature becomes high. On the other hand, if the number average molecular weight of more than 7,000 is used, the physical properties of the sealant after curing become poor.

The mixing ratio of polyether triol and polyether diol used in the production of the urethane prepolymer (A) may be any ratio and is not particularly limited.

Examples of the diisocyanate compound which is the other raw material for producing the urethane prepolymer (A) include various diisocyanate compounds used in the production of ordinary polyurethane resins. Specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, naphthalene-1,5-diisocyanate, and hydrogenation thereof Examples of the above compounds, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, and the like. These diisocyanate compounds may be used alone or in combination of two or more when producing the urethane prepolymer (A).

In producing the urethane prepolymer (A), the amount ratio of the raw materials is such that the equivalent ratio of NCO / OH of the diisocyanate compound to the hydroxyl group of the polyethertriol and polyetherdiol mixture is 1.1 to.
The quantity ratio is 2.5. The reason why the equivalent ratio of NCO / OH is set within the above range is that when the ratio is less than 1.1, the viscosity of the urethane prepolymer (A) becomes too high and it cannot be put to practical use. This is because if it exceeds the above range, a large amount of unreacted polyisocyanate groups remain, and the foaming resistance when used as a sealant decreases.

The production conditions of the urethane prepolymer (A) are not particularly limited as long as they are the usual production conditions of the urethane prepolymer. That is, the reaction temperature is 50 to 1
The reaction may be performed under atmospheric pressure at about 00 ° C. Further, a urethane-forming catalyst such as an organic tin compound or an organic bismuth compound may be used.

Polyurethane compound (B) used in the present invention
Is a polyether polyol having a number average molecular weight of 500 to 3,000, or a number average molecular weight of 500 to 6,000.
After the polyester polyol and the polyisocyanate compound are reacted at an NCO / OH equivalent ratio of 1.1 to 2.5, a monoalcohol having 1 to 22 carbon atoms is further added at an NCO / OH equivalent ratio of 1. The reaction was conducted at 1 to 5.0.

When the polyurethane compound (B) is produced, one having a number average molecular weight of 500 to 3,000 is used. This is because if less than 500 is used, the glass transition temperature becomes high, whereas if more than 3,000 is used, the crystallinity of the reaction product becomes slow and the initial strength of the sealant does not appear.

Among the polyester polyols are polycondensates of polybasic acids such as dicarboxylic acids and polyhydroxy compounds such as glycols. Examples of the polybasic acid include adipic acid, sebacic acid, phthalic acid, maleic acid, glutaric acid and the like. As the polyhydroxy compound, ethylene glycol, diethylene glycol, butylene glycol, neopentyl glycol, hexane glycol,
Examples include trimethylolpropane, glycerin, pentaerythritol and the like. Other than polycondensates, there are polycarbonate polyols having a structure in which alkylene groups are arranged via carbonate bonds, and lactone polyester polyols obtained by ring-opening polymerization of caprolactone monomers.

Polyether polyol or polyester polyol and polyisocyanate compound NCO /
The equivalence ratio of OH is set within the above range because the equivalence ratio is 1.
If it is less than 1, the viscosity of the urethane prepolymer becomes high and it becomes difficult to handle, and the compatibility with the urethane prepolymer (A) decreases and the workability deteriorates.
This is because if it exceeds 2.5, a large amount of unreacted diisocyanate compound remains, so that the crosslinking and curing slows down and the initial strength is not expressed.

The polyisocyanate compound is as described in the description of the urethane prepolymer (A).

The monoalcohol having 1 to 22 carbon atoms includes linear or branched monoalcohol and may be either saturated or unsaturated monoalcohol. In addition, it is a straight chain saturated alcohol and has 2 carbon atoms.
Those of -12 are preferable.

In the production of the polyurethane compound (B), first, the polyether polyol or the polyester polyol and the polyisocyanate compound are reacted to obtain a urethane prepolymer. The amount ratio at that time is the polyether. The equivalent ratio of the isocyanate group (NCO / OH) of the polyisocyanate compound to the hydroxyl group of the polyol or the polyester polyol is 1.1 to 2.5. When this equivalent ratio is less than 1.1, the viscosity of the urethane prepolymer becomes too high, and the compatibility with the urethane prepolymer (A) decreases, while when it exceeds 2.5, the crystallinity is high. It becomes slow and the initial strength of the sealant does not develop.

The production conditions for this urethane prepolymer are as follows:
There is no particular limitation, and ordinary urethane prepolymer production conditions may be used. That is, the reaction may be performed at a reaction temperature of about 50 to 100 ° C. under normal pressure. Further, a urethane-forming catalyst such as an organic tin compound or an organic bismuth compound may be used.

Next, the urethane prepolymer was added to the above-mentioned monoalcohol in an equivalent ratio of NCO / OH of 1.0 to 5.
A polyurethane compound (B) is obtained by reacting as 0 and blocking the isocyanate group to some extent.

The above-mentioned monoalcohol may be used so that the hydroxyl groups of the above-mentioned monoalcohol are excessive with respect to the isocyanate groups of the urethane prepolymer, but normally, the equivalent ratio of NCO / OH is 1.1 to 5. The quantity ratio is 0.0. The equivalent ratio of NCO / OH is set within this range because the adhesiveness is deteriorated in the long-term outdoor exposure test when the equivalent ratio is less than 1.1, and a large amount of isocyanate groups remains when it exceeds 5.0 because the sealant is a sealant. This is because the initial strength of is not exhibited. The equivalent ratio of NCO / OH is preferably 1.1 to 2.5.

The conditions of this reaction are not particularly limited, and the usual conditions for urethanization reaction may be used. That is, the reaction temperature may be about 50 to 100 ° C. and the reaction may be performed under normal pressure, and the unreacted raw materials are separated after the reaction is completed.

The polyurethane compound (B) does not participate in the reaction and acts as a thickening agent that expresses the initial strength of the sealant without increasing the glass transition temperature.

The moisture-curable urethane sealant composition of the present invention contains the urethane prepolymer (A) and the polyurethane compound (B) as essential components, and the amount ratio is 100% of the urethane prepolymer (A). The polyurethane compound (B) is used in an amount of 1 to 25 parts by weight based on parts by weight. The blending amount of the polyurethane compound (B) with respect to the urethane prepolymer (A) is set in this range. When the amount is less than 1 part by weight, the initial strength does not appear, while when it exceeds 25 parts by weight, the glass transition temperature becomes high. This is because.

The moisture-curable urethane sealant composition of the present invention contains, in addition to the above essential components, a plasticizer, a filler, a thixotropic agent, a tackifier, a catalyst, an ultraviolet absorber, a dye, a pigment, a flame retardant, etc. One or more of the above may be contained.

Examples of the plasticizer include benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, citric acid, and the like, polyester, polyether, Examples thereof include epoxy type.

As the filler, silicic acid derivative, talc,
Examples thereof include metal powder, calcium carbonate, clay, carbon black and the like.

Examples of the thixotropic agent include bentone, silicic acid anhydride, silicic acid derivatives, and urea derivatives.

Examples of the catalyst include metal catalysts such as dibutyltin dilaurate, dioctyltin dilaurate, zinc octylate and organic bismuth compounds, amine catalysts such as triethylenediamine and morpholine amine.

In a preferred example of the moisture-curable urethane sealant composition of the present invention, the content of the polyurethane compound (B) is 1 to 25 parts by weight with respect to 100 parts by weight of the urethane prepolymer (A). Is preferred. When the content of the polyurethane compound (B) is within this range, the initial strength of the sealant will not be expressed if it is less than 1 part by weight, and if it exceeds 25 parts by weight, the cured product becomes hard, brittle or liquid. This is because the workability is deteriorated such that the viscosity becomes high.

The moisture-curable urethane sealant composition of the present invention may be produced by mixing the constituent components while melting at about 40 to 80 ° C.

The moisture-curable urethane sealant composition of the present invention, after being applied to one or both of the adherends at about 40 to 80 ° C., rapidly develops initial strength (adhesive strength) by solidification by cooling, Further, by curing in a relatively short time, physical properties of the cured product (elasticity, adhesive strength, etc.) will be exhibited.

[0037]

EXAMPLES The present invention will be specifically described below with reference to examples. (Examples) The following urethane prepolymers (A) and polyurethane compounds (B-1 to 11) having the compositions shown in Table 1 were synthesized and mixed to obtain a moisture-curable urethane sealant composition (Invention Examples 1 to 1). 11) and a urethane compound (Comparative Examples 1 to 4) were produced.

[0038]

[Table 1]

(I) Preparation of Urethane Prepolymer (A) 57 parts by weight of polyoxypropylene triol having 3 hydroxyl groups and having an average molecular weight of 5,000 and 23 parts by weight of polypropylene ether diol having 2 hydroxyl groups and having an average molecular weight of 2,000 Part into a reaction vessel, 110 ℃, 50mm
After dehydration under reduced pressure with Hg for 2 hours, the mixture was cooled to 80 ° C., and 9.1 parts by weight of a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate (80:20) was added thereto with stirring. , 2.2% free isocyanate
Until it becomes tolylene diisocyanate (TD
I) A prepolymer was obtained. Next, 19.6 parts by weight of diphenylmethane-4,4′-diisocyanate was added to this TDI prepolymer, and the mixture was stirred and dehydrated in advance to obtain polyoxypropylene triol 85 having an average molecular weight of 5,000.
35 parts by weight of polypropylene ether diol having an average molecular weight of 2,000 is added and reacted at 80 ° C. until the free isocyanate content becomes 1.8% to obtain a diphenylmethane-4,4′-diisocyanate (MDI) prepolymer. None, urethane prepolymer (A) was obtained.

(II) Production of Polyurethane Compound (1) Polyurethane Compound (B-1) 100 parts by weight of polyethylene ether diol having an average molecular weight of 1,000 was dehydrated under reduced pressure in a reaction vessel at 110 ° C. and 50 mmHG for 2 hours, and then 80 The mixture was cooled to 0 ° C., and 43 parts by weight of diphenylmethane-4,4′-diisocyanate was added thereto with stirring, and reacted until the free isocyanate was 4.1%. To the reaction product, 21 parts by weight of n-hexyl alcohol was added and reacted until the isocyanate group / hydroxyl group (NCO / OH) ratio became 1.33, and then excess alcohol was separated and removed to obtain a polyurethane compound (B -1) was obtained.

(2) Polyurethane compound (B-2) The same procedure as in (1) was conducted using polypropylene ether diol having an average molecular weight of 700 shown in Table 1, diphenylmethane-4,4'-diisocyanate and n-hexyl alcohol. After reacting until the NCO / OH ratio shown in 1 was obtained, excess alcohol was separated and removed to obtain a polyurethane compound (B-2).

(3) Polyurethane Compound (B-3) Using polytetramethylene ether diol having an average molecular weight of 1,000 shown in Table 1, diphenylmethane-4,4'-diisocyanate and n-hexyl alcohol,
After reacting in the same manner as (1) until the NCO / OH ratio shown in Table 1 was obtained, excess alcohol was separated and removed to obtain a polyurethane compound (B-3).

(4) Polyurethane compound (B-4) Adipate polyester diol having an average molecular weight of 2,000 shown in Table 1, hexamethylene diisocyanate and n-hexyl alcohol were used in the same manner as in (1) and shown in Table 1. After reacting until the NCO / OH ratio shown was reached, excess alcohol was separated and removed to obtain a polyurethane compound (B-4).

(5) Polyurethane compound (B-5) Polycarbonate diol having an average molecular weight of 2,000 shown in Table 1, diphenylmethane-4,4'-diisocyanate and n-hexyl alcohol were used in the same manner as in (1). After reacting until the NCO / OH ratio shown in Table 1 was reached, excess alcohol was separated and removed to obtain a polyurethane compound (B-5).

(6) Polyurethane Compound (B-6) Using the polycaprolactone having an average molecular weight of 2,000, hexamethylene diisocyanate and n-hexyl alcohol shown in Table 1, N shown in Table 1 in the same manner as in (1).
After reacting until a CO / OH ratio is reached, excess alcohol is separated and removed to give a polyurethane compound (B-6).
Got

(7) Polyurethane compound (B-7) Using the polycaprolactone having an average molecular weight of 2,000, hexamethylene diisocyanate and n-hexyl alcohol shown in Table 1, N shown in Table 1 in the same manner as in (1).
After reacting until a CO / OH ratio is reached, excess alcohol is separated and removed to give a polyurethane compound (B-7).
Got

(8) Polyurethane compound (B-8) Using the polycaprolactone having an average molecular weight of 2,000, hexamethylene diisocyanate and n-hexyl alcohol shown in Table 1, N shown in Table 1 in the same manner as in (1).
After reacting until a CO / OH ratio is reached, excess alcohol is separated and removed to give a polyurethane compound (B-8).
Got

(9) Polyurethane compound (B-9) Using the polycaprolactone having an average molecular weight of 2,000, hexamethylene diisocyanate and n-hexyl alcohol shown in Table 1, N shown in Table 1 in the same manner as in (1).
After reacting until a CO / OH ratio is reached, excess alcohol is separated and removed to give a polyurethane compound (B-9).
Got

(10) Polyurethane compound (B-10) Using the polycaprolactone having an average molecular weight of 2,000, hexamethylene diisocyanate and n-hexyl alcohol shown in Table 1, N shown in Table 1 in the same manner as in (1).
After reacting until the CO / OH ratio became 10.0, excess alcohol was separated and removed to obtain a polyurethane compound (B-10).

(11) Polyurethane compound (B-11) Polycaprolactone having an average molecular weight of 2,000, diphenylmethane-4,4'-diisocyanate and n-hexyl alcohol shown in Table 1 were used in the same manner as in (1). After reacting until the NCO / OH ratio shown in Table 1 was reached,
Excessive alcohol was separated and removed to obtain a polyurethane compound (B-11).

(III) Production of Moisture-Cure Urethane Sealant Composition 100 parts by weight of the above urethane prepolymer (A) and polyurethane compounds (B-1 to 11) shown in Tables 2 and 3 are added. The mixture was placed in a kneading machine container filled with elemental gas, and 17 parts by weight of dehydrated plasticizer, 100 parts by weight of dry carbon black, and 10 parts by weight of dry calcium carbonate were added, and the mixture was sufficiently kneaded under reduced pressure. Then, a 5% solution of dioctyl tin dilaurate in dioctyl phthalate was added to 1.
7 parts by weight was added, and further sufficient kneading was carried out under reduced pressure to obtain compositions (present invention examples 1 to 11, comparative examples 2 to 4).

(IV) Production of Urethane Composition Plasticizer 2 obtained by placing 100 parts by weight of the above urethane prepolymer (A) in a kneading machine container filled with nitrogen and further dehydrating it.
0 parts by weight, 100 parts by weight of dry carbon black, and 10 parts by weight of dry calcium carbonate were added, and they were sufficiently kneaded under reduced pressure. Then, 1.7 parts by weight of a 5% dioctyltin dilaurate solution of dioctyltin dilaurate was added, and the mixture was sufficiently kneaded under reduced pressure to obtain a polyurethane composition (Comparative Example 1).

With respect to the above composition, H
The physical properties were measured and evaluated using the initial tensile strength of the mold, peel adhesion strength, and hardness as indexes. (Evaluation of H-type initial strength) H-type initial strength is measured by JASO.
338-89 Curing rate measurement It was measured according to the method specified in Method B. That is, the compositions of the present invention and the comparative example were kept at 60 ° C., a triangle having a base of 8 mm and a height of 12 mm was formed on a glass plate, and another glass plate was pressed against this to form a gap between the glass plates. 6 mm, 20 ° C, 65% RH
After being left for 10 minutes in the above environment, the glass plate was peeled off in the direction opposite to the pressing direction, and the H-type tensile strength was measured.

(Physical Properties of Cured Material) In the Production Example, the compositions of the present invention and Comparative Example were kept at 60 ° C., and a sheet having a thickness of 3 mm was formed. The cured product was obtained by leaving it in an environment of 20 ° C. and 65% RH for 7 days. Hardness test according to JISK6301,
The hardness of these compositions was measured. An autograph (manufactured by Shimadzu Corporation) was used as the tester.

(Peeling test) A primer (G-20
0, made by Yokohama Rubber Co., Ltd.) on a glass plate coated with a thickness of 3 mm
The compositions of Examples 1 to 11 of the present invention and Comparative Examples 1 to 4 obtained in Production Examples were applied so that the samples were left for 7 days in an environment of 20 ° C. and 65% RH to obtain a sample for a peel test. . The end of the sample for peel test was pulled by a tensile tester, and a peel test was performed while knife cutting every 10 mm to measure the peel adhesive force and confirm the state of the fracture interface. The case of cohesive failure is indicated by CF, and the case of thin layer failure is indicated by TCF. When simply displayed as CF, it means 100% CF, and when displayed as 10% TCF, for example,
90% indicates CF, but 10% indicates TCF. Regarding the peel adhesion strength of the moisture curable urethane sealant composition of the present invention example and the urethane composition of the comparative example,
The initial peel adhesion and outdoor exposure were compared for 1 year. The results are shown in Tables 2 and 3.

[0056]

[Table 2]

In Table 2, as shown in Table 1, NCO / OH
Of the polyurethane compound (B-1
The results of measurement of H-type initial strength, peel adhesive strength, and hardness in the case of blending 10 parts by weight of B to B-6) with 100 parts by weight of the urethane prepolymer (A) are shown. As shown in Table 2, there was almost no difference in hardness between the moisture-curable urethane sealant compositions of Examples 1 to 6 of the present invention and the urethane composition of Comparative Example 1. Also in the initial peel adhesion, the moisture curable urethane sealant composition of Example 8 of the present invention showed the lowest value, but the urethane composition of Comparative Example 1 was the same as the other moisture curable urethane sealant compositions of the present invention. The value was comparable. However, in each of the moisture-curable urethane sealant compositions of Examples 1 to 6 of the present invention, the H type initial strength was 0.10 kg / cm ² or more, and the initial strength was rapidly developed, while Comparative Example 1 0.06 for the urethane composition
At a value of Kg / cm ² , initial strength was not expressed. Therefore, if the moisture-curable urethane sealant compositions of Examples 1 to 6 of the present invention are used, the window glass can be sufficiently retained with the initial strength due to the increase in the structural viscosity due to crystallization even before the structural strength is exhibited by the moisture curing. However, in the case of Comparative Example 1, the strength for holding the glass cannot be expressed until the structural strength due to moisture curing is expressed.

With respect to the above physical properties when the compounding amount of the polyurethane compound (B-6) was changed from 3 to 30 parts by weight, the results of Inventive Examples 6 to 8 and Comparative Example 2 were shown. (B-6)
Although there was no significant difference in hardness even when the compounding amount of (B-6) was increased, the H type initial strength became higher as the compounding amount of (B-6) increased, and the compounding amount of (B-6) was In Comparative Example 2, which is the largest amount of 30 parts by weight, the maximum value was 0.40 kg / cm ² . On the other hand, the initial peel adhesive strength, which is the reverse of the H-type initial strength, decreases as the compounding amount increases, and in Comparative Example 2 in which the compounding amount of (B-6) is 30 parts by weight, which is the largest, the lowest value is 10 kg / 10 mm. showed that. It was also shown that the peeled state also changed from cohesive failure to partial thin-layer failure, and if the blending amount of (B-6) was too large, the adhesiveness decreased. From the above, when the compounding amount of the polyurethane compound (B) is 30 parts by weight or more, the initial strength,
It was revealed that there is no problem in hardness but the adhesiveness decreases, and that if no compound is added at all, there is no problem in adhesiveness and hardness but the initial strength is not expressed.

[0059]

[Table 3]

In Table 3, the diol compounded in the urethane prepolymer (A) was fixed to 10 parts by weight of polycaprolactone and the NCO / OH equivalent ratio was changed from 1.00 to 10.0. The results of measuring the initial strength, peel adhesion strength and hardness are shown. The peel adhesion strength was measured as an initial peel adhesion strength and a value one year after outdoor exposure. Invention Examples 6 to 1
In the moisture-curable urethane sealant composition of 1 and the urethane compositions of Comparative Examples 3 and 4, even if the NCO / OH equivalent ratio was different, neither hardness nor initial peel adhesion was significantly different. However, H of the urethane composition of Comparative Example 3
The initial mold strength is as low as 0.09 Kg / cm ² , whereas the moisture-curable urethane sealant compositions of Examples 6 to 11 of the present invention are as high as 0.16 to 0.39 Kg / cm ^2. Showed the value. NCO / OH of the urethane composition of Comparative Example 3
Since the equivalence ratio is 10.0, it was shown that the initial strength was not expressed when the NCO / OH equivalence ratio became higher.

On the other hand, in the result of measuring the peel adhesion force after one year of outdoor exposure, a large difference was observed depending on whether the NCO / OH equivalent ratio was within the range of the present invention. That is, NCO
In the urethane composition of Comparative Example 3 in which the / OH equivalent ratio is as high as 10.0, the decrease in peel adhesion strength is 1 from the initial 20 kg / 10 mm.
It was 6 kg / 10 mm, but the NCO / OH equivalent ratio was 1.00
With the urethane composition of Comparative Example 4, which is low, the initial 28 kg / 10 m
It dropped significantly from m to 9 kg / 10 mm. In addition, the peeling state was initially cohesive failure, but it was 100% thin layer failure, indicating poor durability. Invention Example 6-
The moisture-curable urethane sealant composition of No. 11 showed no significant decrease in peel adhesive strength after 1 year of outdoor exposure, and the peeling state was cohesive failure after 1 year of outdoor exposure. It was shown to be excellent in sex. From the above, when the NCO / OH equivalent ratio is as low as 1.00, there is no problem in the initial strength and hardness, but the peel adhesive strength after one year after outdoor exposure is greatly reduced, and the peeled state also becomes a thin layer destruction. Further, it was revealed that when the NCO / OH equivalent ratio is as high as 10.0, there is no problem in peel adhesion and hardness, but initial strength is not expressed.

[0062]

EFFECTS OF THE INVENTION According to the present invention, a reactive hot melt which is particularly suitable for adhesion of window glass of automobiles, can exhibit initial strength even before the development of structural strength by moisture curing, and has good adhesiveness. Moisture curable urethane sealant compositions are provided. Therefore, when the moisture-curable urethane sealant composition of the present invention is used, workability is improved, and in particular, since it is excellent in holding automobile window glass, it is possible to shorten the manufacturing time and also occur during the working process. Since it is possible to prevent the window glass from being displaced, it is possible to omit the step of correcting the displacement.
Further, since the cured product of the moisture-curable urethane sealant composition of the present invention maintains good adhesive strength even after 1 year of outdoor exposure, by using the sealant composition, a product of higher quality than before can be marketed. Will be provided.

Claims (1)

[Claims] 1. A mixture of a polyether triol having a number average molecular weight of 1,000 to 7,000 and a polyether diol, in which a diisocyanate compound has an isocyanate group / hydroxyl group equivalent ratio of 1.1 to 2.5. And a number average molecular weight of 500
After reacting a polyether polyol having a molecular weight of 500 to 3,000 or a polyester polyol having a number average molecular weight of 500 to 6,000 with a polyisocyanate compound at an amount ratio of an isocyanate group / hydroxyl group equivalent ratio of 1.1 to 2.5. ,
Furthermore, it contains a polyurethane compound (B) obtained by reacting a monoalcohol having 1 to 22 carbon atoms at an isocyanate group / hydroxyl group equivalent ratio of 1.1 to 5.0, and the content of the polyurethane compound (B) is Urethane prepolymer (A) 1
A moisture-curable urethane sealant composition, characterized in that it is 1 to 25 parts by weight with respect to 00 parts by weight.