JPH0351754B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a polyurethane-based hot melt adhesive especially for textiles, which has an excellent texture in the adhesive part and has improved water resistance and solvent resistance (dry cleaning resistance). It is something. [Prior Art] Hot melt adhesives are solvent-free, and when heated, bonding is completed instantaneously, providing strong adhesive strength.
Therefore, in recent years, many hot melt adhesives for textiles have already been developed and commercialized in the textile industry for reasons such as streamlining, labor saving, and speeding up the adhesive process. However, currently commercially available hot melt adhesives for textiles such as adhesive sewing, adhesive interlining, non-woven fabric binders, and adhesives for patch pens, names, and marks cannot be used to improve the texture and water resistance of the bonded area. Solvent properties cannot always be satisfied. Commercially available hot melt adhesives include polyolefin, polyamide, polyethylene-vinyl acetate (EVA), polyester, and polyurethane. For example, polyamide adhesive has relatively high adhesive strength and excellent solvent resistance. The agent is
In particular, when bonded in a film form, a rough and hard feeling remains in the bonded area, making it impossible to create a bonded area with a good texture that does not impair the characteristics of the outer material, and the water resistance is also unsatisfactory when used in hot water. isn't it. In addition, polyester adhesives that have a particularly high affinity with polyester woven fabrics have the advantage of high adhesive strength, but have poor solvent resistance. On the other hand, polyurethane adhesives individually exhibit relatively good properties in terms of the texture of the bonded area, water resistance, and resistance to petroleum solvents, but no adhesive has been found that satisfies all three at the same time. Not yet. In other words, when a film-like polyurethane adhesive is used, one with a good texture at the adhesive part does not have sufficient water resistance and/or solvent resistance, and on the other hand, one with good texture in the adhesive part does not have sufficient water resistance and/or solvent resistance. However, the texture of the bonded area is not satisfactory. Further, among dry cleaning solvents, chlorinated solvents (such as perchlorethylene and trichloroethane) have a high risk of causing swelling, and require great care when handling them. [Problems to be Solved by the Invention] The present invention has been made by intensive study to produce a polyurethane hot melt adhesive that overcomes the conventional problems, and
This is how we arrived at the present invention. That is, an object of the present invention is to provide a polyurethane-based hot melt adhesive that has an excellent texture at the bonded portion and has excellent water washing resistance and dry cleaning resistance. [Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and the gist of the invention is as follows. That is, a high molecular weight diol a with a molecular weight of 500 or more, a divalent isocyanate compound b, a chain extender c
and a molecular weight regulator d as a main component, a monool having a hindered nitrogen atom-containing piperidine ring is used as at least a part of the molecular weight regulator d, and the weight ratio of b+c+d/a+b+c+d is about 0.2 to
The object of the present invention is to provide a polyurethane-based hot melt adhesive made of polyurethane having a number average molecular weight of 30,000 to 80,000 obtained by reacting the polyurethane as 0.5. One of the features of the present invention is that as a molecular weight regulator,
The point is that the molecular weight of the polyurethane produced is adjusted to 30,000 to 80,000 by using a monool having a piperidine ring containing a hindering nitrogen atom. When hot melt adhesives are used for textiles, they need to have an appropriate melt viscosity because the resin flows out below the heat-resistant temperature of the outer fabric, penetrates into the fabric appropriately, and develops adhesive strength. . For this reason, the molecular weight of polyurethane used in hot melt adhesives must be controlled within a certain range, and is generally kept to a much lower molecular weight than thermoplastic elastomers. The molecular weight of polyurethane is usually adjusted by adjusting the ratio of total isocyanate groups/total hydroxyl groups in the polyurethane component (hereinafter referred to as isocyanate index), or
Alternatively, a method is known in which a molecular weight regulator is added to the constituent components of polyurethane. For example, as a method for controlling the molecular weight of the latter, Japanese Patent Publication No. 10388/1988 describes a method using a monohydric primary alcohol such as ethanol, and
Publication No. 48792 describes a method using a monohydric secondary alcohol. However, when the molecular weight modifiers described in these publications are applied to hot melt adhesives, they are effective in improving fluidity when hot and reducing melt viscosity, but they are effective in improving the water resistance of the adhesive layer,
Solvent resistance and mechanical properties will be significantly reduced. On the other hand, with the method of adjusting the molecular weight using an isocyanate index, the molecular weight of the resulting polymer fluctuates greatly if the index deviates slightly from the desired value, and it is relatively difficult to adjust the molecular weight to a certain range. . Therefore, we conducted an investigation to find a molecular weight modifier that would take advantage of the advantages of using a molecular weight modifier and also cause less deterioration in the performance of the resulting polyurethane hot melt adhesive.As a result, we found that a monool having a piperidine ring containing a hindered nitrogen atom was found. I found it to be suitable for this purpose. . A method for using a monool having a piperidine ring containing a hindered nitrogen atom (hereinafter referred to as a piperidine ring monool) in a polyurethane composition has already been disclosed in JP-A-55-18409 and JP-A-59-1999.
102950, but there is no description of a molecular weight adjustment method that minimizes the decrease in mechanical properties, water resistance, and solvent resistance. One of the features of the present invention is that a piperidine ring monool is used as a molecular weight regulator in a hot melt adhesive as a method for reducing the molecular weight with less deterioration in water resistance, solvent resistance and mechanical properties. Piperidine ring monool refers to the two ortho positions (2-position and 6-position) of the nitrogen atom of the piperidine ring.
A monool that has two lower alkyl groups in each position and a hydroxyl group or an organic acid group containing an alcoholic hydroxyl group in another position, and the hydrogen atom bonded to the hindered nitrogen atom is substituted with a lower alkyl group, etc. may also be substituted. In the latter case, the hydrogen atom bonded to the nitrogen atom is substantially inert or has very low reactivity toward the isocyanate group. The reason why the performance of hot melt adhesives using piperidine ring monool as a molecular weight modifier is relatively higher than when using other molecular weight modifiers is thought to be due to the nitrogen atom of the piperidine ring or the hydrogen atom bonded to it. For example, a hydrogen bond between this hydrogen atom and a functional group of a polyurethane chain can be considered. A further advantage of the present invention is that the piperidine ring monool has a photostabilizing effect. It is well known that polyurethane polymers are susceptible to yellowing and deterioration due to ultraviolet rays, and yellowing is a problem when hot melt adhesives are used for adhesive fibers for textiles, adhesive interlining, nonwoven fabric binders, etc. It may happen. On the other hand, the polyurethane hot melt adhesive obtained by the present invention has high photostability, and because the piperidine ring is bonded to the polyurethane chain, problems such as stabilizer bleed are unlikely to occur. . The piperidine ring monool in the present invention is a compound having at least one hindered nitrogen atom-containing piperidine ring skeleton represented by the following formula [] and one alcoholic hydroxyl group. However, the four R ₁ 's may be the same or different, and at least two are methyl groups, and the others are alkyl groups having 4 or less carbon atoms. 1 of the piperidine ring skeleton represented by the above formula []
At least one of the 3rd, 4th, and 5th positions has a substituent, and one of the substituents (excluding the 1st position) is a hydroxyl group or an organic group having an alcoholic hydroxyl group. . In particular, the 4th position has a hydroxyl group or a hydroxyl group-containing organic group, and the 3rd and 5th positions have no substituents or at least one of them.
Preferably, the compound has a lower alkyl group.
The 4th position may have two substituents, and they may form a ring. Examples of such piperidine ring monools include those described in Japanese Patent Application Laid-Open No.
Publication No. 1294, Japanese Patent Application Publication No. 1983-39395, Japanese Patent Application Publication No. 1987-39395
Piperidine ring monools described in JP-A-40780, JP-A-55-18409, etc. can be used. A preferred piperidine ring monool is a compound represented by the following formula []. R ₁ : Same as R1 in formula [] R ₂ : Monovalent group having no hydrogen atom or hydroxyl group R ₃ : Hydrogen atom or alkyl group having 4 or less carbon atoms A: Alkylene group or mono- or polyoxyalkylene group k: 0 or 1 Among the compounds represented by the formula [], more preferred are compounds in which all R ₃ are hydrogen atoms and A is an alkylene group having 6 or less carbon atoms or an oxyalkylene group. Particularly preferred compounds are 4-hydroxy-2,2,6,6-tetramethylpiperidine (hereinafter referred to as hindered piperidinol), its N-alkyl substituted product (hereinafter these two types of compounds are referred to as compound A), and 4-
(2-hydroxyethyl)2,2,6,6-tetramethylpiperidine and its N-alkyl substituted product (hereinafter referred to as compound B). When using the piperidine ring monool mentioned above, if it is a secondary alcohol like Compound A, Compound A can be present from the beginning of the reaction when a high molecular weight diol etc. and a diisocyanate compound are reacted. Further, it may be present when the isocyanate group-terminated prepolymer and the divalent chain extender are reacted. Furthermore, it can also be added when the viscosity reaches the desired viscosity while the polyurethane forming reaction is progressing. Since compound B is a primary alcohol,
It is preferably used in the prepolymer together with a chain extender or during the final polyurethane forming reaction. In the present invention, the piperidine ring monool is used as a molecular weight regulator to control the number average molecular weight of the produced polyurethane to 30,000 to 80,000. If the number average molecular weight of polyurethane is less than 30,000, water resistance, solvent resistance, mechanical properties, etc. will be poor when used as a hot melt adhesive. Moreover, the melt viscosity when melted becomes too low. On the other hand, 8
If it exceeds 10,000, the fluidity of the adhesive deteriorates when hot, and in the case of fabrics such as nylon, it is difficult to bond unless the temperature is raised above the heat-resistant temperature of the fabric. Further, when used for adhesive sewing, etc., heat shrinkage causes a problem of the outer fabric becoming loose, which is not preferable. Another feature of the present invention is that the main components are a high molecular weight diol a having a molecular weight of 500 or more, a divalent isocyanate compound b, a chain extender c, and a molecular weight regulator d, and the weight ratio of b+c+d/a+b+c+d is
The purpose is to react at a concentration of 0.2 to 0.5. More preferably, the reaction is carried out at a weight ratio of b+c+d/a+b+c+d of about 0.25 to 0.45. The required performance of a hot melt adhesive for textiles is the flexibility of the adhesive, and especially when a hot melt adhesive is used in the form of a film, the texture of the bonded area is very important.
If the weight ratio of b+c+d/a+b+c+d exceeds 0.5, the adhesive will become hard, leaving a rough and hard feel in the bonded area and impairing the texture of the outer material. Therefore,
The smaller the weight ratio of b+c+d/a+b+c+d, the better the flexibility of the hot melt adhesive. However, if the weight ratio of b+c+d/a+b+c+d is less than 0.2, water resistance, solvent resistance, and mechanical properties will deteriorate, resulting in problems, so 0.2 to 0.5 is preferable. More preferably, it is about 0.25 to 0.45. In addition, the structure of polymer diol a has a large influence on the texture of the bonded part.
For this purpose, polyester diols or polyoxytetramethylene diols having a molecular weight of 500 or more are preferred. More preferably, polyester diol with a molecular weight of 800 to 3000 or polyoxytetramethylene diol with a molecular weight of 600 to 2000 is used. Examples of polyester diols include esters of adipic acid and one or more dihydric alcohols such as polyethylene adipate, polybutylene adipate, polyhexylene adipate, polyneopentyl adipate, polyethylene-butylene adipate, and polyneopentyl-hexyl adipate. Other examples include polycaprolactone diol and phthalate diol. For hot melt adhesives for textiles, it is particularly preferable to use polyethylene-butylene adipate, which has particularly high adhesive flexibility. Furthermore, when high water resistance is required, it is preferable to use a mixture of polyethylene-butylene adipate and a relatively highly hydrophobic polyester diol. Preferred polyester diols with relatively high hydrophobicity include polybutylene adipate, polyhexylene adipate, polyneopentyl adipate, and polyneopentyl-hexyl adipate. The proportion of polyethylene-butylene adipate is preferably about 20 to 100% by weight, more preferably about 25 to 75% by weight, based on the total diol. If the highly hydrophobic polyester glycol exceeds about 80% by weight, the hot melt adhesive film not only has poor flexibility but also tends to have poor solvent resistance (dry cleaning resistance). Furthermore, when polyoxytetramethylene diol is used in a polyurethane-based hot melt adhesive, it has higher water resistance than polyester diol, but its solvent resistance is slightly inferior. This tendency is more pronounced as the molecular weight of polyoxytetramethylene diol increases. Therefore, the molecular weight of polyoxytetramethylene diol is preferably 600 to 2,000, more preferably 600 to 1,200. As the divalent isocyanate compound b, aromatic, aliphatic, alicyclic, and other diisocyanate compounds and modified products thereof can be used. For example, tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, p
-phenylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, methylene bis(cyclohexyl isocyanate), hexahydrotolylene diisocyanate,
Examples include isophorone diisocyanate. These may be a mixture of isomers, or some or all of them may be modified products. The most preferred divalent isocyanate is diphenylmethane diisocyanate. The chain extender c is a compound having a molecular weight of about 300 or less and having two primary hydroxyl groups or two amino groups, especially an aliphatic compound having a molecular weight of about 200 or less.
Hydrolic alcohols are preferred. Examples of divalent chain extenders include ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6
-hexanediol, neopentyl glycol,
Examples include N-methyldiethanolamine, ethylenediamine, isophoronediamine, diaminodicyclohexylmethane, diaminodiphenylmethane, and 1,4-butanediol and 1,6-hexanediol are particularly preferred. Note that two or more of these divalent chain extenders may be used in combination. The usage ratio of the main raw materials of the above-mentioned polyurethane hot melt adhesive is b+c+d/
Although limited by the weight ratio of a+b+c+d, it is preferable to adjust the usage ratio so that the isocyanate index is about 0.9 to 1.05. More preferably, the isocyanate index is 0.93 to 1.03. If the isocyanate index exceeds 1.05, excess isocyanate tends to cause a crosslinking reaction during the urethane forming reaction, which deteriorates the hot melt adhesive's flow characteristics. Furthermore, when the isocyanate index is less than 0.9, water resistance, solvent resistance, mechanical properties, etc. tend to deteriorate. Polyurethane-based hot melt adhesives are obtained from the above-mentioned main raw materials, but other auxiliary raw materials such as catalysts, stabilizers, colorants, etc. may also be used. Suitable catalysts are organometallic compounds, especially organotin compounds and tertiary amines. As stabilizers, ultraviolet absorbers, light stabilizers, antioxidants, etc. may be used. A polyurethane hot melt adhesive is produced using the above raw materials by a method such as a prepolymer method or a pseudo-prepolymer method. In the present invention, since the viscosity of the prepolymer is very high, it is preferable to employ a pseudo-prepo method in which a portion of the polymeric diol is added to the prepolymer later together with a chain extender. The hot melt adhesive of the present invention is particularly effective when used in the form of a film such as a tape, and the preferred method for forming the film is the melt film forming method.
Extruded into a film at a molding temperature of ~100℃,
Film. The thickness of this film is not particularly limited, but is suitably about 50 μm to 1 mm. The film may be embossed, but it is preferable not to actively stretch it. The thus obtained polyurethane film hot melt adhesive is sandwiched, for example, between woven or nonwoven fabrics of the same or different types, and bonded by heating and softening using a hot roller, hot press, ironing, or the like. The hot melt adhesive of the present invention is specially designed to be used in the form of a film such as a tape, but it can be used by melting the block as it is and using a general hot melt applicator such as a roll coater or nozzle. It is also possible to apply it. It is also possible to powder it and use it for adhesion. Furthermore, although the hot melt adhesive of the present invention is particularly suitable as an adhesive for textiles as described above, since it is an adhesive with relatively high mechanical properties, it can be used for base materials other than textiles, such as plastics,
It can also be used for adhesion between the same or different base materials such as metals, ceramics, and wood materials, or for adhesion between these and fiber base materials. For example, metal sheets and foils such as aluminum, plastic sheets, films, and molded products such as polyester resin, vinyl chloride resin, and polyurethane resin, surfaces coated with polyurethane paints and acrylic paints, surfaces such as glass, ceramics, and wood. It has high adhesion to, and can be used for adhesion between base materials of the same kind or different kinds, and between these base materials and fiber base materials. Suitable fiber base materials include woven fabrics and nonwoven fabrics made of fibers of nylon, polyester, acrylic, cotton, and other materials. It is particularly suitable for adhering clothing fabrics made of fibers of these materials alone or blended with fibers of other materials, and plastic films. [Examples] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. In the examples, "parts" represent parts by weight unless otherwise specified. Moreover, "molecular weight" represents the number average molecular weight measured by gel permeation chromatography. Example 1 After dehydrating 65 parts of polyethylene-butylene adipate diol (hereinafter referred to as PEBA) with a molecular weight of about 2000 by heating and vacuum degassing, hindered piperidinol (i.e., 2,2,6,6-tetramethyl-4-hydroxy Mix 1.5 parts of diphenylmethane diisocyanate (hereinafter referred to as MDI) and dissolve it in PEBA with stirring.
The mixture was stirred at 80°C for 2 hours. A premixed mixture of 35 parts of PEBA having a molecular weight of about 2000 and 4.6 parts of 1,4-butanediol (hereinafter referred to as 1,4-BD) was added to this reaction mixture, and the mixture was rapidly stirred. Heat generation was observed with the start of the reaction, and after about 5 minutes, the mixture was poured into a drying container coated with fluororesin and heated at 130℃ for 5 minutes.
A polyurethane hot melt block made of polyurethane with a molecular weight of 48,000 was obtained by holding for a certain period of time. After crushing this block and making it into round pellets, 40 mm
Thickness at extrusion temperature of about 130-150℃ with φ single screw extruder
A 150μ film was produced by extrusion. The tensile strength of the obtained film was about 180 kg/cm2. This film was slit into 1 cm wide tape and sandwiched between two pieces of T/C broad (polyethylene terephthalate fabric/cotton cloth) at 120°C, 140°C, and 160°C.
When heated and pressed for 10 seconds at a pressure of 1 kg/cm ² using a hot press machine heated to 100 mL, the peel strengths of the bonded portions were 3, 5, 4.1, and 4.5 kg/cm, respectively. The texture of the bonded area was not impaired at all, and there was no seepage from the woven fabric. In addition, the adhered T/C broad was washed with detergent concentration 0.3%, bath ratio 1:50, time 10 minutes x 5
Washing resistance test conducted twice at a temperature of 80℃,
As a result of conducting a dry cleaning resistance test in 25℃ and perchlorethylene for 10 minutes x 5 times, the adhesive strength was 96% and 92%, respectively.
was held in. Comparative Example 1 As a molecular weight regulator, 0.71 part of 1-butanol (Example 1) was used instead of hindered piperidinol.
The molecular weight was 4.6 in the same manner as in Example 1 except that the same number of moles as the hindered piperidinol was used.
Got 10,000 polyurethane. Next, a film with a thickness of 150μ was made in the same manner as in the example, and its adhesion to T/C broad was examined.
The peel strengths were 1.5, 1.6, and 1.9 Kg/cm, and all peeled off in the washing resistance test. Incidentally, the tensile strength of this film was quite low at 60 Kl·cm ² . Comparative Example 2 After dehydrating 65 parts of PEBA with a molecular weight of about 2000 by heating and vacuum degassing, 1.5 parts of hindered piperidinol was mixed and dissolved in PEBA with stirring. 80.2 parts of MDI was added thereto, and the mixture was heated at 80°C under a nitrogen stream. Stirred for 2 hours. To this reaction mixture was added 35 parts of PEBA with a molecular weight of about 2000 and 1,4-
A mixed solution of 23.3 parts of BD was added and mixed quickly with stirring. Polyurethane (molecular weight 75,000) was obtained in the same manner as in Example 1, and a 150 μ thick film was made from it (tensile strength was 530 Kg/cm ² ). The film was hard and the adhesive part to the T/C broad was A rough hard feeling remained, and the peel strengths at 120°C, 140°C, and 160°C were 1.8, 2.6, and 4.0 kg/cm, respectively. Comparative Example 3 After dehydrating 65 parts of PEBA with a molecular weight of about 2000 by heating and vacuum degassing, 1.5 parts of hindered piperidinol was mixed and dissolved in PEBA with stirring, 18.8 parts of MDI was added thereto, and the mixture was heated at 80°C under a nitrogen stream. Stirred for 2 hours. To this reaction mixture was added 35 parts of PEBA with a molecular weight of about 2000 and 1,4-
A mixed solution of 1.7 parts of BD was added, and the mixture was rapidly stirred and mixed. Polyurethane (molecular weight: 30,000) was obtained in the same manner as in Example 1, and a 100 μ thick film was made from it (tensile strength: 40 Kg/cm ² ).
Peel strength at 140℃ and 160℃ is 1.2, 1.1, and 0.9, respectively.
Kg/cm, and all peeled off in the washing resistance test and dry cleaning resistance test. Example 2 After dehydrating 65 parts of PEBA with a molecular weight of about 2000 by heating and vacuum degassing, 1.0 part of hindered piperidinol was mixed and dissolved in PEBA with stirring. 45.4 parts of MDI was added thereto, and the mixture was heated at 80°C under a nitrogen stream. Stirred for 2 hours. To this reaction mixture was added 35 parts of PEBA having a molecular weight of about 1000 and 1,4-
A mixed solution of 7.5 parts of BD was added, and the mixture was quickly stirred and mixed. Polyurethane (molecular weight: 62,000) was obtained in the same manner as in Example 1, a film with a thickness of 150μ was made from it (tensile strength was 380Kg/cm ² ), and its adhesion to nylon cloth was examined. , 140℃, 160℃
The peel strengths are 3.1, 4.0, and 4.3Kg/cm, respectively.
In addition, the adhesive strength after washing resistance test and dry cleaning resistance test was 97℃ and 92%, respectively.
All results were good. Example 3 32.5 parts of PEBA with a molecular weight of about 2000 and polyhexylene adipate diol (hereinafter referred to as PHA) with a molecular weight of about 2600
After dehydrating by heating and vacuum degassing, 1.0 part of hinderpiperidinol was mixed and dissolved in PEBA with stirring, 25.9 parts of MDI was added thereto, and the Stir for hours. To this reaction mixture was added 17.5 parts of DEBA, which has a molecular weight of approximately 2000, and
A mixed solution of 17.5 parts of PHA 2600 and 6.4 parts of 1,6-hexanediol (hereinafter referred to as 1,6-HD) was added and mixed rapidly with stirring. Hereinafter, polyurethane was obtained in the same manner as in Example 1 (molecular weight 60,000),
A film with a thickness of 100μ was made from this (tensile strength was 280Kg/cm ² ). This film was slit into tapes with a width of 1 cm and the adhesion to T/C broad was examined, and the peel strength at 140°C was 4.3 kg/cm for each.
The feel of the adhesive was good. In addition, good adhesion was maintained even after washing resistance tests and dry cleaning resistance tests. The above film was sandwiched between PET film/nylon fabric and urethane film/nylon fabric to examine adhesive strength. All exhibited high adhesion with a peel strength of 2.0 to 6.5 Kg/cm at 120 to 160°C, and the bonded portion was flexible. Example 4 In Example 3, the added amount of hindered piperidinol, which is a molecular weight regulator, was changed to 0.3 parts, 0.5 parts, and 1.0 parts.
Five types of films were made in the same manner as in Example 3, except that 1.5 parts, 1.5 parts, and 2.0 parts were used, and the molecular weight and tensile strength of each film were measured. The adhesion to /C broad and the washing resistance of the adhered T/C broad were investigated. (Table 1)

[Table] ×...Peeling Example 5 65 parts of polyoxytetramethylene diol (hereinafter referred to as PTMG) with a molecular weight of about 1000 was dehydrated by heating and vacuum degassing, and 1.5 parts of hindered piperidinol was mixed in and stirred into PTMG. Dissolve this into MDI44.1
The mixture was stirred at 80° C. for 2 hours under a nitrogen stream. Add 35 parts of PTMG with a molecular weight of about 1000 to this reaction mixture,
A mixed solution of 8.2 parts of 6-HD was added and mixed quickly with stirring. Polyurethane was obtained in the same manner as in Example 1 (molecular weight: 60,000), a film with a thickness of 150μ was made from it (tensile strength was 300Kg/cm ² ), and its adhesion to T/C broad was examined. 120℃, 140
The peel strength at ℃ and 160℃ is 3.3, 3.8, and 3.9Kg/, respectively.
cm, and the texture of the bonded area was good. Also,
Good adhesion was maintained even after washing resistance test and dry cleaning resistance test. [Effects of the Invention] The hot melt adhesive of the present invention has excellent adhesiveness and texture, and also has excellent water resistance (washing resistance) and solvent resistance (dry cleaning resistance).
Ideal as an adhesive for clothing fabrics made of nylon, polyester, acrylic, cotton, and their blends.

Claims (1)

[Claims] 1. High molecular weight diol a having a molecular weight of 500 or more, 2.
isocyanate compound b, a chain extender c, and a molecular weight regulator d as main components, a monool having a hindered nitrogen atom-containing piperidine ring is used as at least a part of the molecular weight regulator d, and further b+c+
A polyurethane-based hot melt adhesive made of polyurethane having a number average molecular weight of 30,000 to 80,000 obtained by reaction at a weight ratio of d/a+b+c+d of 0.2 to 0.5. 2. The hot melt adhesive according to claim 1, wherein the high molecular weight diol a is a polyester diol. 3. The hot melt adhesive according to claim 1, wherein the high molecular weight diol a is polyoxytetramethylene diol. 4. The hot melt adhesive according to claim 1, wherein the hot melt adhesive is a film hot melt adhesive. 5. The hot melt adhesive according to claim 1, wherein the hot melt adhesive is a hot melt adhesive for fibers.