JPS6329904B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester-based reactive hot melt adhesive. In recent years, as clothing made of polyethylene terephthalate fibers has come into widespread use, polyester-based hot melt adhesives with good adhesive properties have come to be used as interlining for clothing. Currently commercially available polyester hot melt adhesives have less elasticity and softer properties than polyamide adhesives, do not yellow, and do not shine, making them suitable for thin polyester clothing, but they have poor dry cleaning resistance. Because of its poor quality, its use is limited to light clothing that does not need to be dry cleaned. A common drawback of hot melt adhesives is that the adhesive undergoes plastic deformation during repeated ironing, leading to changes in texture and adhesive strength. The present inventors have conducted various studies on polyester-based hot melt adhesives that can improve these shortcomings, have excellent dry cleaning resistance and ironing resistance, and have a soft texture that can be used in a wide range of fiber bonding applications. He has now completed his invention. That is, the present invention provides (a) aromatic dicarboxylic acid residues 30 to 49
Mol%, (b) General formula () (wherein R is an alkyl group or alkenyl group having 4 to 20 carbon atoms) 0.1 to 5 mol% of dicarboxylic acid residues,
(c) 0 to 20 mol% of aliphatic dicarboxylic acid residues having a straight chain of 4 to 12 carbon atoms or a methyl group as a side chain, (d)
30 to 49 mol% of aliphatic diol residues having 2 to 10 carbon atoms, (e) 0 to 10 mol% of poly(oxyalkylene) glycol residues having a number average molecular weight of 500 to 2,500, and
(f) General formula () (In the formula, R' is an alkylene group having 2 to 4 carbon atoms, x
+y is 2 to 18) At the molecular chain end of polyester (A) composed of 0.1 to 15 mol% of aromatic diol residues represented by
(g) A hot melt adhesive comprising an isocyanate group-containing polyester obtained by reacting a polyfunctional isocyanate compound. In this specification, a dicarboxylic acid residue refers to a chemical structure in which a hydroxyl group is removed from the carboxyl group of a dicarboxylic acid, and a diol residue refers to a chemical structure in which a hydrogen atom is removed from a hydroxyl group in a diol. The aromatic dicarboxylic acid residue (a) of the present invention includes:
For example, terephthalic acid, isophthalic acid, phthalic acid,
Diphenyl-p,p'-dicarboxylic acid, diphenyl-m,m'-dicarboxylic acid, diphenylmethane-
p, p'-dicarboxylic acid, diphenylmethane-m,
m'-dicarboxylic acid, 2,2'-bis(4-carboxyphenyl)propane, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene- 2,7-dicarboxylic acid, diphenyl ether-p,p'-dicarboxylic acid, diphenyl ether-m,m'-dicarboxylic acid, diphenylsulfone-p,p'-dicarboxylic acid, diphenylsulfone-
Examples include residues of m,m'-dicarboxylic acids and lower alkyl ester derivatives thereof. The dicarboxylic acid residue (b) represented by the general formula () of the present invention includes n-dodecenylsuccinic acid, iso-dodecenylsuccinic acid, isododecylsuccinic acid, isooctylsuccinic acid, n-octylsuccinic acid, n-butylsuccinic acid, and n-butylsuccinic acid. Examples include residues of acids and their acid anhydrides or lower alkyl ester derivatives. A linear aliphatic dicarboxylic acid residue having 4 to 12 carbon atoms or having a methyl group as a side chain according to the present invention
(c) includes succinic acid, glutaric acid, adipic acid,
β-methyladipic acid, pimelic acid, corkic acid,
Examples include residues of azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, and derivatives thereof. Examples of the aliphatic diol residue (d) having 2 to 10 carbon atoms in the present invention include ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, pentamethylene glycol, and hexamethylene glycol. , heptamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, diethylene glycol, triethylene glycol, and the like. Examples of the poly(oxyalkylene) glycol residue (e) of the present invention include residues such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol having a number average molecular weight of 500 to 2,500. The residue (f) of the aromatic diol represented by the general formula () of the present invention is polyoxyethylene
(4)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene 2-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene(6)-2,2-bis( 4-Hydroxyphenyl)propane, polyoxyethylene(12)-
Examples include residues such as 2,2-bis(4-hydroxyphenyl)propane. The copolymerized polyester (A) used in the present invention is obtained by polycondensing the above-mentioned dicarboxylic acid component and diol component by a known method such as a direct esterification method or a transesterification method under conditions where the diol component is in excess. The proportion of aromatic dicarboxylic acid residues (a) among the above components contained in the polyester skeleton of the present invention is
30 to 49 mol% is preferred. If it is less than 30 mol%, even if a crosslinked structure is formed by isocyanate groups, dry cleaning resistance is poor and the softening point of the hot melt adhesive before the crosslinking reaction becomes too low, which is not preferable. On the other hand, if it exceeds 49 mol%, the resin will not only become too hard and affect the texture of the bonded clothing, but also have a high softening point before the crosslinking reaction, which means that it must be applied at a high temperature and the adherend will be exposed to heat. This is not desirable as it makes it easy to be attacked. Next, the proportion of dicarboxylic acid residues in (b) is preferably 0.1 to 5 mol%. The dicarboxylic acid residue has the effect of lowering the softening point of the resin and softening the hand, but if its proportion exceeds 5 mol%, the softening point of the resin may become too low, or even after the crosslinking reaction. It is not preferred because it lacks dry cleaning resistance. The proportion of the aliphatic dicarboxylic acid residue (c) is preferably 0 to 20 mol %, and if it exceeds 20 mol %, the dry cleaning resistance decreases even after the crosslinking reaction, which is not preferable. If the proportion of aliphatic diol residue (d) is less than 30 mol%, the resin becomes hard, so it is preferably 30 to 49 mol%. Although the poly(oxyalkylene) glycol residue (e) has the effect of softening the resin, dry cleaning resistance is insufficient even after crosslinking with a proportion exceeding 10 mol%, and the softening point of the resin before crosslinking. It is preferable to use 0 to 10 mol %, since blocking is likely to occur if the amount becomes too low. The aromatic diol residue (f) provides an excellent adhesive effect, but if it exceeds 15 mol %, the resin becomes hard, so it is preferably 0.1 to 15 mol %. (g) The polyfunctional isocyanate compound used in the present invention includes 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,
4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3 , 3'-dimethyl-4,4'-diphenyl diisocyanate, and 1,5-naphthalene diisocyanate. In addition, trifunctional or higher functional polyisocyanates such as polymethylene polyphenyl isocyanate, 4,4′,4″-triphenylmethane triisocyanate, trimethylolpropane-toluene diisocyanate adduct, dimer and trimer of toluene diisocyanate, etc. The addition reaction between the polyisocyanate and the above-mentioned polyester is carried out by adding polyisocyanate in an amount of 1.0 to 2.0 times the number of end groups of the polyester after the completion of the polycondensation reaction of the polyester. 80 under pressure
This can be carried out by melt mixing at a temperature of from 180°C to 180°C. Alternatively, the polyester and polyisocyanate may be mixed at the above ratio in a solvent for the polyester that does not have hydrogen atoms active with respect to isocyanate groups, and the mixture may be reacted under heating. If necessary, a catalyst such as tertiary amine, stannath octoate, dibutyltin dilaurate, etc. may be used. When the reaction is carried out in a solution state, the solvent is removed by evaporation after the reaction is completed. JIS of the reactive hot melt adhesive of the present invention
The softening point measured by the ring and ball method according to K2817 is 60 to 160°C, more preferably 80 to 130°C. If the softening point is lower than 60°C, even after the crosslinking reaction by the isocyanate group has progressed, plastic deformation of the resin will be observed every time heat compression bonding such as ironing is repeated, resulting in a change in the texture of the bonded clothing, which is undesirable. If the softening point is 160°C, the adhesion temperature to clothing must be higher than that, which is undesirable because the fibers are more likely to be thermally deformed. Antioxidants, fillers, colorants, lubricants, etc. may be added to the reactive hot melt adhesive of the present invention, if necessary. The reactive hot melt adhesive of the present invention can be subjected to various morphological processes such as pelletization, film formation, rod formation, fiber formation, powder formation, etc. in a dry atmosphere. The reactive hot melt adhesive made of a polyester resin having isocyanate groups thus obtained can be stored for a long period of time if sealed in a dry state with a moisture content of 0.05% or less. In the reactive hot melt adhesive of the present invention, the isocyanate group at the end of the polyester molecular chain reacts with moisture in the air or moisture on the surface of the adherend to cure the adhesive. Humidification using steam or the like will speed up the curing speed. Further, if the adherend contains hydrogen atoms that are active toward isocyanate groups, crosslinking also occurs in the adherend. Thus, the reactive hot melt adhesive of the present invention exhibits instant adhesive properties unique to hot melt adhesives and excellent solvent resistance and heat resistance due to crosslinking, and also exhibits excellent adhesion to polyethylene terephthalate fibers. The effect of the soft segments in the polyester chain gives the bonded clothing an appropriate texture. The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. Note that parts in the examples mean parts by weight. Example 1 Dimethyl terephthalate 48.5 parts (25 mol%) Dimethyl isophthalate 27.2 (14) Dimethyl adipate 17.4 (10) 1,4-butanediol 61.3 (68) Polytetramethylene glycol (molecular weight approx. 1000)
20.0〃(2〃) Polyoxyethylene(2)-2,2-bis(4-hydroxyphenyl)propane 15.8〃(5〃) Tetra-n-butoxytitanium
0.080〃 was placed in a separable flask and the temperature was raised to 220°C to carry out the transesterification reaction. After about 90% of the theoretical amount of methanol was distilled off, 1.5 parts (1 mol %) of n-butylsuccinic anhydride was added and esterification was carried out for about 40 minutes while raising the temperature to 240°C. Next, the temperature was raised to 250℃ and the pressure was gradually reduced to 1mmHg under a nitrogen atmosphere.
Polycondensation reaction was carried out in the following vacuum for 3 hours to obtain a polyester resin. Incidentally, excess 1,4-butanediol was removed from the system during the reaction. The acid value of the polyester resin was 1.2KOHmg/g, and the hydroxyl value was 16.5KOHmg/g (MW=
6339). For 100 parts of the polyester resin, 4,4'-
Diphenylmethane diisocyanate was charged in a proportion of 8.8 parts into a kneader and melted and kneaded at 120°C for about 60 minutes in a dry nitrogen atmosphere, then transferred to an extruder and extruded at 130°C to obtain a reactive hot melt adhesive. The softening point of the adhesive measured by the ring and ball method in silicone oil was 125°C. Apply the adhesive in a hot melt applicator at 140° C.
It was melted at 0.degree. C. and applied linearly to a 65%/35% polyester/cotton broadcloth at a coating weight of 0.5 g/m.
Immediately, the same type of cloth was layered and compressed for about 10 seconds at a pressure of about 200 g/cm ² while humidifying with a steam iron. No adhesive seeped out from the adhesive sample, and the feel was good. One week after adhesion, a hot water washing resistance test and a dry cleaning resistance test were conducted using the methods described below, and as shown in Table 1, a high adhesion retention rate was shown. Furthermore, no adhesive seepage or change in texture was observed even after repeated ironing. In the hot water resistance washing test, washing was repeated five times for 10 minutes at a detergent concentration of 0.3%, a bath ratio of 1:50, and a temperature of 60°C. The dry cleaning resistance test was conducted using percrene in a bath ratio of 1:50 and shaking at a temperature of 30°C for 10 minutes, which was repeated 5 times. In both cases, drying was done naturally (air drying). The peel strength was determined by T-peeling at 23° C. and a tensile speed of 200 mm/min.

[Table] Example 2 Dimethyl terephthalate 48.5 parts (25 mol%) Dimethyl isophthalate 44.7 (23) 1,4-butanediol 58.6 (65) Neopentyl glycol 6.6 (5) Polyoxyethylene ( 12)-2,2-bis(4-hydroxyphenyl)propane 37.8〃(5〃) Tetra-n-butoxytitanium
0.080〃 was placed in a separable flask and the transesterification reaction was carried out in the same manner as in Example 1. After about 90% of the theoretical amount of methanol was distilled off, 5.4 parts (2 mol%) of isododecylsuccinic anhydride was added. Example 1 below
Esterification and polycondensation reactions were carried out in the same manner as described above. The acid value of the obtained polyester resin is
0.9KOHmg/g, hydroxyl value is 12.8KOHmg/
g (MW=8190). A ratio of 4.5 parts of hexamethylene diisocyanate to 100 parts of the polyester resin was charged into a kneader and melted and kneaded at 130°C in a dry nitrogen atmosphere for about 60 minutes, then transferred to an extruder and extruded at 140°C to obtain a reactive hot melt adhesive. I got it. The softening point of the adhesive was 128°C. 150°C of the adhesive in a hot melt applicator.
0.5g/m melted on polyester jersey cloth at °C
It was applied in a linear manner with a coating amount of . Then, immediately layer the same type of cloth and use a steam iron to moisturize it.
Pressure bonding was carried out at 130° C. and a pressure of about 200 g/cm ² for about 10 seconds.
There was no adhesive seepage and the texture was good.
A hot water washing resistance test and a dry cleaning resistance test were carried out in the same manner as in Example 1. As a result, as shown in Table 2, it was found that the adhesive retention rate was high.

【table】

Claims (1)

[Claims] 1 (a) 30 to 49 mol% of aromatic dicarboxylic acid residues, (b)
General formula () (wherein R is an alkyl group or alkenyl group having 4 to 20 carbon atoms) 0.1 to 5 mol% of dicarboxylic acid residues,
(c) 0 to 20 mol% of aliphatic dicarboxylic acid residues having a straight chain of 4 to 12 carbon atoms or a methyl group as a side chain, (d)
30 to 49 mol% of aliphatic diol residues having 2 to 10 carbon atoms, (e) 0 to 10 mol% of poly(oxyalkylene) glycol residues having a number average molecular weight of 500 to 2,500, and
(f) General formula () (In the formula, R' is an alkylene group having 2 to 4 carbon atoms, x
+y is 2 to 18) At the molecular chain end of polyester (A) composed of 0.1 to 15 mol% of aromatic diol residues represented by
(g) A hot melt adhesive comprising an isocyanate group-containing polyester obtained by reacting a polyfunctional isocyanate compound.