JP2001026762A - Reactive hot-melt adhesive and adhesive interlining cloth using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactive hot-melt adhesive having a sufficiently long usable life and excellent in durability, etc. SOLUTION: This reactive hot-melt adhesive comprises (A) 60-98% of a condensation-based polymer having an active hydrogen group of >=200 eq/T and a weight-average molecular weight of >=40,000 and (B) 2-40% of a blocked isocyanate compound, wherein a polyesterurethaneurea which is formed by adding a compound having both of amino and hydroxyl groups to a urethane prepolymer formed by polymerizing a polyesterpolyol and a polyisocyanate with, if necessary, a chain extender is, for example, used as the condensation- based polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a hot-melt adhesive which maintains thermoplasticity at room temperature or relatively low temperature and can be processed and bonded as a hot-melt adhesive. The present invention relates to a reactive hot melt adhesive exhibiting heat resistance and adhesiveness.

[0002]

2. Description of the Related Art Hot-melt and solution-type adhesives are used in various fields. However, hot-melt as an environmentally-friendly adhesive is deteriorating due to organic solvent treatment and cost increase due to water treatment. It is an excellent adhesive not only for bonding automotive parts, assembling electronic parts and for textiles, but also for expanding its applications in the future. However, since it is based on a thermoplastic resin, the adhesive strength, durability, heat resistance, chemical resistance, and the like are often inferior to those of a curable solution-type adhesive.

[0003] For example, as an adhesive for textile use, thermoplastic polyester and polyamide thermoplastic and condensed polymers are used for adhesive interlining applications. In particular, polyester resins have an adhesive property to polyester clothing. It has good characteristics such as good flexibility and non-yellowing, and is suitable for adhesives for clothing. However, the polyester resin adheres relatively well to the polyester fiber, but has poor adhesion to the other fiber. Further, polyamide-based resins adhere to relatively various types of fibers, but there is a problem in that the adhesiveness decreases with time in cleaning resistance and washing resistance (water resistance). Moreover, since it is thermoplastic, it has a restriction that it can be used only in a temperature range lower than its melting point by 10 to 30 ° C. or more, and heat resistance is insufficient.

Therefore, in recent years, there has been a demand for the development of a reactive hot melt adhesive which does not decrease in adhesiveness over time for the purpose of improving various performances. For example, Tokiko 07-1
No. 7890 proposes a moisture curing system using a urethane prepolymer of polyester. Moisture curing reaction type terminal isocyanate prepolymer type adhesives have been studied in several fields mainly for automotive applications. However, since the moisture-curable adhesive reacts with the moisture in the atmosphere, it needs to be distributed in a special storage container, and when applying the adhesive, special adhesives such as a completely sealed hot melt coater can be used. Since the apparatus is required, the initial cost is large, and there are problems in workability and cost. Further, it is not suitable for a system in which curing is not required immediately after application to an interlining, such as an adhesive interlining application, and which is desired to be cured by secondary heating with an iron or the like. Also, JP-A-03-93877, JP-A-04-253785, and JP-A-09-1
58055 and the like have proposed a reactive adhesive using a blocked isocyanate. In such a system, the isocyanate block is removed by heating and moisture curing starts, so that the timing of curing can be adjusted. However, in order to obtain sufficient curing, a high temperature and a long time are required for block dissociation and reaction, which adversely affects the fiber.
Therefore, by using a main agent having a large amount of active hydrogen groups, an effective curing system can be obtained in a short time. However, the introduction of large amounts of active hydrogen groups into condensation polymers such as polyamides and polyesters, which are mainly used in adhesives for fibers, has been proposed as a product obtained in a stable form. Not.

As described above, according to the conventional technology, it is possible to use the conventional equipment for hot melt adhesives, and further to a system that requires a sufficiently long pot life after application, such as an adhesive interlining application. No applicable reactive hot melt adhesives have been proposed.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reactive hot melt adhesive having a sufficiently long pot life and excellent durability, while solving the above-mentioned problems. And

[0007]

In order to achieve the above object,
The present inventors have conducted intensive studies and have come to propose the following invention.

That is, according to the present invention, (a) an active hydrogen group having 200
Equivalent / T or more and a weight average molecular weight of 40,000
A reactive hot melt adhesive comprising the above-mentioned condensation polymer at 60 to 98% and (a) 2 to 40% of a blocked isocyanate compound. An adhesive interlining using the adhesive.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The condensation polymer having (a) an active hydrogen group of 200 equivalents / T or more used in the present invention is stable at room temperature, but (a) the block isocyanate compound dissociates the block by heating. When an isocyanate group is generated, it immediately reacts with the active hydrogen group of the condensation polymer (A) to extend or cure the molecule, thereby improving the adhesive property and maintaining the adhesive performance for a long time. At this time, when the active hydrogen group of the condensation polymer (A) is located only at the terminal of the molecule or is small, the amount of heat and time required for the curing reaction may damage the fiber or cause a sufficient curing reaction. Can not be obtained. Therefore, amino groups, O
As a method for introducing a large amount of active hydrogen groups such as H group and thiol group, for example, as shown in Japanese Patent Publication No. 4-8856, an OH group is prepared by reacting only an amino group of a chain extender having an amino group and a hydroxyl group. Or a method of leaving
As disclosed in JP-A-07733, a method of introducing an OH group polyfunctional compound into polyester urethane can be mentioned.
In particular, the former method can introduce a highly reactive primary OH group into the main chain while maintaining the linearity of the main chain. This is preferable because the curability can be significantly increased while maintaining the same. In this case, as the material of the condensation polymer, a polyester urethane urea in which a compound having both an amino group and a hydroxyl group is added to a urethane prepolymer polymerized with a polyester polyol and a polyisocyanate and a chain extender as necessary, is preferable. .

The polyester urethane urea as the condensation polymer used in the present invention is used as a polyester polyol. As a hot melt adhesive, it is used at a temperature of 130 ° C. In order to avoid the occurrence of damage to adherends such as fibers due to heating required to melt the high melting point compound, it is preferable to maintain sufficient crystallinity at a melting point of 50 to 130 ° C after urethane formation. Desirably, the melting point is 50 to 80 ° C. in order to obtain high adhesion to various fibers. In order to obtain initial adhesiveness immediately after application of the adhesive, a crystalline polyester polyol having a number average molecular weight of 2,000 or more is desirable.

The dibasic acid component of the crystalline polyester polyol includes terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid,
Aromatic dibasic acids such as 4,4'-diphenyldicarboxylic acid, 2,2'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, adipic acid, azelaic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid Aliphatic and alicyclic dibasic acids such as 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, and dimer acid; and particularly, terephthalic acid. , Isophthalic acid and adipic acid are preferred.

As the glycol component, ethylene glycol, propylene glycol, 1,3-propanediol-
2-methyl-1,3-propanediol, 1,2-
Butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentaneddiol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentylglycol -Diethylene glycol,
Dipropylene glycol, 2,2,4-trimethyl-
1,3-pentaneddiol, cyclohexanedimethanol
, Tricyclodecane dimethanol, neopentyl hydroxypivalate, ethylene oxide adducts and propylene oxide adducts of bisphenol A, ethylene oxide adducts and propylene oxide adducts of hydrogenated bisphenol A, 1, Low-molecular-weight diols such as 9-nonanediol, 2-methyloctanediol, 1,10-dodecanediol, 2-butyl-2-ethyl-1,3-propanediol, and tricyclodecanedimethanol are exemplified. 1,4-butanediol and 1,6-hexanediol are preferred in order to maintain crystallinity. Examples of high molecular weight diols include polyethylene glycol, polypropylene glycol, polyether polyols such as polytetramethylene glycol and polycaprolactone, and polyester polyols such as polycarbonate diol, and polycaprolactone is preferred from the viewpoint of good crystallinity. .

The polyisocyanate constituting the polyester urethane urea as the condensation polymer used in the present invention may be one kind or a mixture of two or more kinds as long as it contains an isocyanate group. For example, it may be a mixture of diisocyanate, its dimer (uretdione), and its trimer (isocyanurate). Examples of the diisocyanate component constituting the polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and p-phenylene diisocyanate.
Diphenylmethane diisocyanate, m-phenylene diisocyanate, hexamethylene diisocyanate
, Tetramethylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylenediisocyanate,
1,5-naphthalenediisocyanate, 2,6-naphthalenediisocyanate, 3,3'-dimethyl-4,4 '
-Diisocyanate, 4,4'-diisocyanato diphenyl ether, 1,5-xylylene diisocyanate
G, 1,3-diisocyanatomethylcyclohexane,
1,4-diisocyanatomethylcyclohexane, 4,
Examples thereof include 4'-diisocyanate-cyclohexane, 4,4'-diisocyanate-cyclohexylmethane, and isophorone diisocyanate. However, yellowing is often a problem in fiber applications and the like. Hexamethylene diisocyanate and isophorone diisocyanate, which are cyclic diisocyanates, are preferred.

Examples of the chain extender constituting the polyester urethane urea used in the present invention include a low molecular weight diol as a glycol component when synthesizing a polyester polyol, and a carboxyl group-containing compound such as dimethylolpropionic acid and dimethylolbutanoic acid. Low molecular weight diols and the like.

Compounds having both an amino group and a hydroxyl group, which are added to the urethane prepolymer obtained by reacting the polyester polyol, the polyisocyanate and, if necessary, the chain extender at an NCO / OH molar ratio of 1 or more, include: Examples include metaxylylenediamine ethylene oxide 2 mol adduct and metaxylylenediamine propylene oxide 2 mol adduct. The molecular weight of the obtained polyester urethane urea is preferably in the range of 40,000 to 300,000 in terms of weight average molecular weight. When the weight average molecular weight is less than 40,000, the initial adhesive strength is reduced. Furthermore, since a long heating time is required for curing, it is not suitable for applications requiring relatively fast curability, such as adhesive interlining applications. In addition, the molecular weight is 300,000
If it exceeds, the melt viscosity becomes too high, so that sufficient penetration cannot be obtained, making it difficult to apply as a hot melt adhesive for fiber use.

The concentration of active hydrogen groups in the polyester urethane urea used in the present invention may be 200 eq / T (ton) or more. More preferably, it is 500 eq / T or more. When curing at a low temperature and in a short time is required as in the case of an adhesive interlining, a sufficient active hydrogen group concentration is required because sufficient time and energy are not obtained for all the functional groups to react.

As a reaction method of the polyester urethane urea, a polyester polyol, a polyisocyanate and, if necessary, a chain extender are charged into a reaction vessel in advance to prepare a urethane prepolymer, which has both an amino group and a hydroxyl group. The compound is put into the reaction vessel at once, or a compound having both an amino group and a hydroxyl group is put in the reactor in advance, and the urethane prepolymer prepared in another reaction vessel is gradually added. You may put in. This reaction can be produced by reacting in the presence or absence of a solvent inert to isocyanate groups. In order to obtain a product as a reactive hot melt at low cost, it is desirable to carry out the reaction in the absence of a solvent. When preparing in the presence of a solvent, the solvent may be an ester solvent (ethyl acetate,
Butyl acetate, ethyl butyrate, etc.), ether solvents (dioxane, tetrahydrofuran, diethyl ether, etc.), ketone solvents (cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, etc.), aromatic hydrocarbon solvents (benzene, toluene, xylene, etc.) and These mixed solvents may be mentioned, but dimethylformamide or dimethylacetamide, which is an aprotic hydrophilic solvent, is preferable in view of the solubility of the formed crystalline polyester urethane urea. Examples of the reaction device include a reaction can equipped with a stirring device, a kneader, and a mixing and kneading device such as a twin-screw extruder.In the absence of a solvent, a compound having both an amino group and a hydroxyl group and a urethane prepolymer are used. A twin-screw extruder capable of high-speed rotation at a rotation speed of 300 rpm or more is more preferable because polyurethane urea which can be kneaded at a stroke and has a high viscosity can be extruded.

In order to promote urethane and urea reactions,
Catalysts used in ordinary reactions, for example, tin catalysts (such as trimethyltin laurate, dimethyltin dilaurate, trimethyltin hydroxide, dimethyltin dihydroxide, and stannas octoate), and lead catalysts (red oleate, red-2-) Ethylhexoate, etc.) Amine-based catalysts (triethylamine, tributylamine, morpholine, diazabicyclooctane, etc.) can be used, but are selective when reacting a compound having both amino groups and hydroxyl groups with a urethane prepolymer. In order to cause a urea reaction, a reaction without a catalyst is desirable. The reaction can be carried out at a temperature not lower than the melting point of the resin and up to 140 ° C., preferably 100 ° C. or lower for the selective reaction of urea.

The reactive hot melt adhesive of the present invention is prepared by mixing (a) an appropriate amount of a blocked isocyanate group with a condensation polymer having an active hydroxyl group of 200 equivalents / T or more as compound (a). Since the compound (a) is required to have low-temperature reactivity, a blocked isocyanate having a low dissociation temperature is required. There is no particular limitation on the isocyanate component used, but when used for fiber applications, non-yellowing aliphatic or alicyclic isocyanates are preferred. The blocking agent is not limited as long as it enables low-temperature dissociation, but those which are not discharged out of the system after dissociation are preferable. For example, 3,5-dimethylpyrazole and the like can be mentioned. The weight ratio of the compounds (A) and (A) is 60/40
It is desirably ９８98/2. More preferably, 7
5/25 to 95/5. The method of mixing the compounds (A) and (A) may be mixing of powders, or melting or mixing with a solution.

Further, additives such as a lubricant such as silica may be added to the reactive hot melt adhesive of the present invention within a range not to impair the reactivity, depending on the purpose of use.

The reactive hot-melt adhesive of the present invention can be applied by completely conventional methods for applying a hot-melt adhesive such as melt coating with a hot-melt coater, powder dot coating, and aqueous paste coating.

[0022]

The present invention will be specifically illustrated by the following examples. In the examples, “parts” means “parts by weight”.

<Description of Abbreviations> The abbreviations are as follows. Polyester Polyester (A): terephthalic acid / adipic acid //
1,4-butanediol (35/65 // 100 molar ratio, number average molecular weight 10,000, melting point 83 ° C.) Polyester (B): terephthalic acid / adipic acid //
1,6-hexanediol (50/50 // 100 molar ratio, number average molecular weight 7,000, melting point 72 ° C) Polyester (C): polycaprolactone, number average molecular weight 3,000, melting point 60 ° C Polyester (D) : Polycaprolactone, number average molecular weight 32,000, weight average molecular weight 65,000, melting point 60 ° C) Chain extender BD: 1,4-butanediol NPG: neopentyl glycol Multifunctional monomer MXDA-EO2: metaxylylenediamine Ethylene oxide 2 mol adduct MXDA-PO2: Propylene oxide 2 mol adduct of meta-xylylenediamine TMP: Trimethylolpropane Polyisocyanate HDI: Hexamethylene diisocyanate IPDI: Isophorone diisocyanate Catalyst TPP: Triphenylphosph Down

<Synthesis Example 1 of Polyester Urethane Urea Containing Active Hydrogen Group> In a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 100 parts of the polyester (A) described in the description of abbreviations in Table 1 were added. Charge NPG 9 parts 110
After heating and melting at 25 ° C., 25 parts of HDI was added. The reaction was carried out at 125 ° C. for 30 minutes to obtain a urethane prepolymer. The urethane prepolymer is kept at 90 ° C. and the stirrer is stopped. Twelve parts of MXDA-EO2 were put into this at once.
After the introduction, the stirrer is started, and sufficient stirring is performed for 90 minutes for 90 minutes.
C. Table 1 shows the properties of the obtained polyester urethane urea. In Table 1, the weight average molecular weight was determined by gel permeation chromatography using tetrahydrofuran as a solvent and polystyrene as a standard.
It was measured by a differential scanning calorimeter under the condition of minutes. The hydroxyl group concentration was determined by charge calculation. As a result, the active hydrogen group concentration became 730 equivalents / T.

<Synthesis Examples 2 to 4 of Polyester Urethane Urea Containing Active Hydrogen Group> Polyesters (B) to (C) described in the description of abbreviations in Table 1 in the same manner as in Synthesis Example 1.
Using such raw materials, crystalline polyester urethane ureas (2) to (4) were obtained. Table 1 shows the characteristics of the polyester urethane urea.

[0026]

[Table 1]

<Comparative Synthesis Examples 1 to 3 of Polyester Urethane or Polyester Urethane Urea> In the same reactor as in Synthesis Example 1, raw materials such as polyesters (A) to (D) described in the description of abbreviations in Table 1 were used. Using crystalline polyester urethane or polyester urethane urea (R1)
(R3) was obtained. Table 2 shows the properties of the polyester urethane or polyester urethane urea. Comparative Synthesis Example 1
Nos. 2 to 2 have an active hydrogen group concentration of as low as 200 equivalents / T or less and are outside the scope of the present invention. Comparative Synthesis Example 3 has a molecular weight outside the scope of the present invention.

[0028]

[Table 2]

Example 1 100 parts of the crystalline polyester urethane urea obtained in Synthesis Example 1 (compound (A))
And a 3,5-dimethylpyrazole block of isophorone diisocyanate trimer (Baxenden “BI
-7952 "), 10 parts (compound (a)), TPP at 0.
Add 1 part, freezer mill (SPEX industrial)
This was frozen and pulverized together with liquid nitrogen using IES, Inc. “6750”) to obtain a fine powder having a particle size of 250 μm or less.
This is screened with a polyester interlining (70 g /
m ² ) was applied at 10 g / m ^2, and was temporarily attached in an oven at 105 ° C. for 1 minute. One day after the tacking, a polyester outer material (150 g / m ² ) was superimposed on the adhesive interlining, and ironed at 150 ° C. for 15 seconds at a pressure of 300 g / cm ² . Immediately after bonding or after one day, pulling speed 100m
The T peel strength was measured at m / min. Similarly, the T-peel strength of the adhesive interlining three weeks after tacking was measured one day after adhesion. The peel strength after washing with water at a temperature of 40 ° C. × 15 minutes (washing test) and the peel strength after immersion in a dry cleaning liquid (perchlorethylene) and stirring with a stirrer at 30 ° C. for 15 minutes (cleaning test) were also measured. Table 3 shows the results. In addition, the composition in Table 3 shows the weight composition ratio in a fine powder.

<Examples 2 to 4, Comparative Examples 1 to 3> Tables 3 and 4
In the same manner as in Example 1, a fine powder was obtained from the composition described in Example 1, and the peel strength was evaluated. Tables 3 and 4 show the results.
Shown in In the examples, better adhesion than the initial,
Good results were obtained after three weeks of tacking. Further, even by washing and dry cleaning, almost no decrease in adhesion was observed. However, in the comparative example, good adhesiveness and durability were not exhibited.

[0031]

[Table 3]

[0032]

[Table 4]

[0033]

As described above, the present invention can be applied as a normal polyester hot melt resin since no reactivity is exhibited at a temperature at which the resin melts as a hot melt resin.
When the uretdione ring is dissociated by reheating at a higher temperature to exhibit reactivity, a reactive hot melt adhesive excellent in adhesiveness and durability can be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J040 EF071 EF111 EF331 GA05 GA14 JB01 JB02 LA01 LA05 LA08 NA11

Claims (2)

[Claims] (1) 60 to 98% of a condensed polymer having an active hydrogen group of 200 equivalents / T or more and having a weight average molecular weight of 40,000 or more, and (a) 2 to 40% of a blocked isocyanate compound A reactive hot melt adhesive characterized by comprising: 2. An adhesive interlining using the reactive hot melt adhesive according to claim 1.