JP2000109535A - Polyurethane and elastic fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyurethane which consists of a high-molecular polyol, an organic polyisocyanate, a low-molecular polyol, and a specific chain- elongating agent, has a high thermosetting property and keeps an excellent elasticity recovery even after the thermosetting process, and is useful for producing elastic fibers and so on. SOLUTION: This polyurethane consists of (A) a high-molecular polyol (e.g. polybutylene adipate), (B) an organic polyisocyanate (e.g. diphenylmethanediisocyanate), and (C) a chain-elongating agent which contains, as a component, a compound shown by the formula (R is a divalent hydrocarbon, a divalent halogenated hydrocarbon or the like; R' is a direct bond, a divalent hydrocarbon or the like; A1-A4 are each H, a 1-6C hydrocarbon, an alkoxyl or the like) [e.g. bis(2-hydroxyethyl)-(4-hydroxyphenyl)isocyanurate]. It is preferable that the ratio of the total number of hydroxyl groups of components A and C versus the number of isocyanate groups of component B is (1:0.95)-(1:1.15).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane characterized by having excellent elastic recovery properties and having a part of urethane bonds reversibly dissociated and bonded at a certain temperature. When polyurethane is used as the elastic fiber, in a fabric or the like in which the elastic fiber is woven,
The present invention relates to a polyurethane elastic fiber having a high heat setting rate at a certain temperature or higher and having excellent elastic recovery after the heat setting step as well as before the heat setting step. Specifically, it is a polyurethane comprising a polymer polyol, an organic polyisocyanate, and a chain extender, wherein one component of the chain extender has a phenol structure or a benzyl alcohol structure. And a resilient fiber obtained therefrom.

[0002]

2. Description of the Related Art Conventionally, in the production of polyurethane, especially in the production of polyurethane elastic fibers, high-molecular diols, organic diisocyanates and low-molecular diols are often used. The elastic recovery of polyurethane is not always satisfactory. Particularly in the field of elastic fibers, when the polyurethane elastic fibers are woven into a cloth or the like and passed through a heat setting step, the heat setting ratio is high, but the elastic recovery of the polyurethane elastic fibers after setting is satisfactory. Not something you can do.

As an elastic fiber, polyurethane urea using a low molecular weight diamine instead of a low molecular weight diol is widely used. Since polyurethane urea has a strong urea bond with hydrogen bonding ability, it has high heat resistance, and the elastic recovery after passing through the heat setting step is also at a satisfactory level as before the heat setting step. There is a characteristic that it is low.

[0004] That is, in the conventional technique, it is impossible to obtain an elastic fiber having a high heat setting rate and an excellent elastic recovery property, particularly excellent elastic recovery property after passing through the heat setting step. This is because polyurethanes having such properties have not been obtained before.

[0005] On the other hand, although different from polyurethane, rubber crosslinked by vulcanization or the like is excellent in heat resistance and elastic recovery due to chemical bond crosslinking. However, it is very difficult to mold such a chemically crosslinked polymer, especially to an elastic fiber, and it can be said that the heat setting rate is very low from the viewpoint of heat setting.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a polyurethane having an excellent elastic recovery property comparable to that of a chemically crosslinked rubber from a high molecular weight polyol, an organic polyisocyanate or a low molecular weight polyol; An object of the present invention is to provide a polyurethane elastic fiber which has a high heat setting ratio at a certain temperature or higher and has excellent elastic recovery after the heat setting step as well as before the heat setting step.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies and studies, and as a result, have reached the present invention. That is, the present invention is a polyurethane comprising a polymer polyol, an organic polyisocyanate, and a chain extender, wherein one component of the chain extender is represented by the following general formula (1) or the following general formula (2) ), And an elastic fiber obtained therefrom.

[0008]

Embedded image (In the above formula, R represents a divalent hydrocarbon structure, a divalent halogenated hydrocarbon structure, or a divalent hydrocarbon in which a hydrocarbon is bonded to an ether bond, an ester bond, an amide bond, a urethane bond, or a urea bond. R ′ represents a direct bond, a divalent hydrocarbon structure, a divalent halogenated hydrocarbon structure, a hydrocarbon is an ether bond, an ester bond, an amide bond, a urethane bond, or a urea. Represents a structure selected from the divalent structure linked to a bond: A1, A2, A3, A4
Is hydrogen, a hydrocarbon group having 6 or less carbon atoms, an alkoxyl group,
Represents a group selected from halogen groups, and may be the same or different. )

[0009]

Embedded image (In the above formula, R represents a divalent hydrocarbon structure, a divalent halogenated hydrocarbon structure, or a divalent hydrocarbon in which a hydrocarbon is bonded to an ether bond, an ester bond, an amide bond, a urethane bond, or a urea bond. R ′ represents a direct bond, a divalent hydrocarbon structure, a divalent halogenated hydrocarbon structure, a hydrocarbon is an ether bond, an ester bond, an amide bond, a urethane bond, or a urea. Represents a structure selected from the divalent structure linked to a bond: A1, A2, A3, A4
Is hydrogen, a hydrocarbon group having 6 or less carbon atoms, an alkoxyl group,
Represents a group selected from halogen groups, and may be the same or different. B1 and B2 represent a group selected from hydrogen, a hydrocarbon group having 6 or less carbon atoms, and a halogen group, and may be the same or different. )

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The high molecular weight polyol used in the present invention includes polyether polyols typified by polytetramethylene ether glycol and polyester polyols typified by polybutylene adipate. , Polycaprolactonepolyol, polyesterpolycarbonatepolyol exemplified by a reaction product of a polyesterglycol such as polycaprolactone with an alkylene carbonate, etc., and ethylene carbonate as ethylene glycol. −
Propylene glycol, butylene glycol, neopentyl glycol, and other polyvalent alcohols,
Then, the obtained reaction mixture was reacted with an organic dicarboxylic acid such as adipic acid, azelaic acid, and sebacic acid,
And 1,4-butanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol,
Examples thereof include a polycarbonate resin obtained by a transesterification reaction of a polyhydroxyl compound such as 1,8-octanediol and an aryl carbonate, for example, diphenyl carbonate. These may be used alone or in combination of two or more.

Further, as the organic polyisocyanate,
4,4'-diphenylmethane diisocyanate, 1,5
-Naphthalene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate,
Aromatic diisocyanates such as 2,6-tolylene diisocyanate; benzylic diisocyanates such as m-xylylene diisocyanate and p-xylylene diisocyanate
Aliphatic diisocyanate, such as hexamethylene diisocyanate, and 1,4-cyclohexane diisocyanate
G, 4,4'-dicyclohexylmethane diisocyanate
And alicyclic diisocyanates such as isophorone diisocyanate. These may be used alone or in combination of two or more.

Compounds that can be used as one component of the chain extender include bis (2-hydroxyethyl)-
(4-Hydroxyphenyl) isocyanurate [formula (3) below], bis (4- (2-hydroxyethoxy) phenyl)-(4-hydroxyphenyl) isocyanurate [formula (4)], and the like. Can be. These are 1
They may be used alone or as a mixture of two or more.

[0013]

Embedded image

[0014]

Embedded image

Compounds that can be used as one component of the chain extender include bis (2-hydroxyethyl)-(4- (hydroxymethyl) phenyl) isocyanurate [formula (5) below] (2-hydroxyethyl)-(4- (hydroxymethyl) benzyl) isocyanurate [formula (6) below] and the like.
These may be used alone or in combination of two or more.

[0016]

Embedded image

[0017]

Embedded image

As the chain extender, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis (hydroxyethoxy) benzene, 1,3-bis (hydroxyethoxy) benzene, 1,2-bis (hydroxyethoxy) benzene, cyclohexanedimethanol, bis (2-hydroxyethyl) terephthalate, bis (2
-Hydroxyethyl) isophthalate, bis (2-hydroxyethyl) phthalate, 2,2-bis (4- (hydroxyethoxy) phenyl) propane and the like can be used in combination. These may be used alone or in combination of two or more.

In the present invention, the ratio between the high molecular weight polyol and the chain extender can be variously changed depending on the molecular weight of each and the desired physical properties of the polyurethane. In addition, the number of isocyanate groups (N
CO / OH) is preferably in the range of 0.80 to 1.25,
More preferably, it is 0.95 to 1.15. If the ratio is too small, the crosslinked structure is insufficient and the elastic recovery is reduced, which is not preferable.If the ratio is too large, the melt viscosity is small, the solidification rate is low, and the surface adhesiveness is large, and the productivity is reduced. Not preferred.

In the present invention, since the obtained polyurethane uses a trifunctional compound as a raw material, it has a crosslinked structure. Generally, polyurethane constrains the soft segment by the cohesive force of the hydrogen bond of the hard segment and exhibits rubber-like characteristics. It can be expected that the elastic recovery is improved.

The polyurethane of the present invention has a crosslinking point by a urethane bond. The crosslinking point is formed by a urethane bond comprising an aromatic hydroxyl group and an isocyanate group or a benzylic hydroxyl group and an isocyanate group. Therefore, it is possible to reversibly dissociate and bond at a lower temperature than a urethane bond of the main chain consisting of an aliphatic hydroxyl group and an isocyanate group. Utilizing this property, the development of elastic fibers with a high heat setting rate and excellent elastic recovery before and after passing through the heat setting process, which was impossible in the field of elastic fibers with conventional technologies, Becomes possible.

That is, since the polyurethane and the polyurethane elastic fiber have a crosslinked structure at room temperature, they have excellent elastic recovery. If the heat setting temperature is set to a temperature higher than the temperature at which the urethane bond forming the crosslink point bond is dissociated, the crosslink will be cut at the heat setting temperature, and the heat setting property will be high. When cooled to room temperature again, the crosslinks are reformed, so that the elastic recovery is excellent even after passing through the heat setting step.

In the polyurethane of the present invention, 0.1 to 25% of all the urethane bonds are reacted with an aromatic hydroxyl group and an isocyanate group, or a benzylic hydroxyl group is reacted with an isocyanate group. It is desirable that the urethane bond be obtained by the following method. Preferably, the urethane bond obtained by reacting an aromatic hydroxyl group with an isocyanate group or the urethane bond obtained by reacting a benzylic hydroxyl group with an isocyanate group is desirably in the range of 0.2 to 15%. If this is too small, sufficient elastic recovery cannot be obtained. On the other hand, if it is too large, the moldability becomes poor, which is not preferable. Among all the urethane bonds, the ratio of the urethane bond obtained by reacting an aromatic hydroxyl group and an isocyanate group, or the urethane bond obtained by reacting a benzylic hydroxyl group and an isocyanate group is, for example, alcohol under heating. It can be determined by reacting the compound with an amine or the like and analyzing it as a soluble polymer by NMR or the like.

The polyurethane of the present invention can be produced by applying a known urethanization technique such as a melting method or a solution method, but is preferably produced by a melting method in consideration of cost, working environment and the like. If necessary, a polyfunctional component such as another triol or triisocyanate may be used in combination.

In the production of polyurethane, catalysts, activators, defoamers, lubricants, stabilizers such as ultraviolet absorbers and yellowing inhibitors, pigments, antistatic agents, surface treatment agents which are usually used are also used. Optional components such as a flame retardant, a fungicide, and a reinforcing agent can be used as needed.

The polyurethane of the present invention comprises a resin, a molded product,
Although it can be widely used for films, elastic fibers, and the like, it is possible to obtain elastic fibers having excellent elastic recovery and a high heat setting rate, particularly when elastic fibers are used. The elastic fiber of the present invention can be produced by a spinning method such as melt spinning, dry spinning, and wet spinning. However, it is preferable to perform melt spinning from the viewpoint of cost, fiber homogeneity, and the like.

The spinning apparatus and spinning conditions used for melt-spinning the polyurethane of the present invention may vary depending on the content of the polyurethane, the desired fiber thickness, the polymerization method, and the like. Usually, the molten polymer is extruded. Supply to the spinning device,
Spinning is preferably performed at a spinning temperature of 180 to 240 ° C. and a spinning speed of 1000 m / min or less, particularly 600 m / min or less. The apparent draft rate is preferably 50 or more, and more preferably 100 or more. The spinning tension when the spun yarn is wound around a bobbin by a winding machine is 0.1 g / g.
d or less, preferably 0.05 g / d or less.

The wound yarn is hardened under low humidity.
It is preferable to perform a heat treatment near the glass transition temperature of the hard segment to sufficiently advance the phase separation between the hard segment and the soft segment. In general, polyurethane elastic fibers having a thickness of about 5 to 100 denier / filament can be obtained by these methods, but the polyurethane elastic fibers used in the present invention have a denier in the range of 15 to 100. It is suitable, preferably 20-80. These elastic fibers are used in the form of a covering yarn or a bare yarn.

[0029]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Parts in the examples are parts by weight. Further, in the following examples, the elastic recovery rate and the heat setting rate were measured by the following methods.

<< Preparation of Evaluation Sample >> Polyurethane polymer
Was sandwiched between two sheets of Teflon sheet, and formed into a film having a thickness of about 0.1 mm at 215 ° C. by a heat press machine. Also,
The production method of the elastic fiber is described in the following examples.

<< Measurement of elastic recovery >>: Using a film tensile tester, a sample (width: 5 mm, thickness: approx.
A 1 mm film) was sandwiched between chucks so as to have a sample length of 50 mm. After elongating 300% at a constant speed of 1000% / min, the film was immediately relaxed at the same speed. 15 of the extension process
The stress at the time of 0% elongation and the stress at the time of 150% elongation in the relaxation process were measured, and were obtained from the following equation. Elastic recovery rate (%) = (stress at 150% elongation in the relaxation process / stress at 150% elongation in the elongation process) × 100 Further, as a measurement of elastic recovery after the heat setting step, the film was subjected to the heat setting rate described below. Processing similar to measurement (100
% Elongation, heat treatment), and the elastic recovery of the film was measured in the same manner as described above.

<< Measurement of Elastic Recovery >> A sample (40 denier, monofilament) is sandwiched between chucks so as to have a sample length of 50 mm using a fiber tensile tester, and 300% at a constant speed of 1000% / min. Immediately after extension, they were relaxed at the same speed. The stress at the time of 150% elongation during the elongation process and the stress at the time of 150% elongation during the relaxation process were measured, and were obtained from the following equation. Elastic recovery rate (%) = (stress at 150% elongation in the relaxation process / stress at 150% elongation in the elongation process) × 100 Further, as a measurement of elastic recovery after the heat setting step, the elastic fiber was subjected to the following heat setting. The same processing as the rate measurement (100
% Elongation, heat treatment), and the elastic recovery of the elastic fiber was measured in the same manner as described above.

<< Measurement of heat setting rate >>: A film sample (a film having a width of 2 mm and a thickness of about 0.1 mm) was sandwiched by an initial length of 20 mm and heated at a certain temperature (dry heat) for 1 minute under 100% elongation. After cooling, the length of the sample when it was relaxed was measured, and the heat setting rate was determined from the following equation. Heat setting rate (%) = {(sample length after heating−initial length) / initial length} × 100

<< Measurement of heat set rate >>: A fiber (40 denier, monofilament) having an initial length of 22.5 cm is heated at 100% elongation at a certain temperature (dry heat) for 1 minute, cooled and then relaxed. The sample length at the time of the above was measured, and the heat setting rate was obtained from the following equation. Heat setting rate (%) = {(sample length after heating−initial length) / initial length} × 100

Example 1 58.5 parts of polybutylene adipate (abbreviated as PBA) having a hydroxyl group at both terminals and having a number average molecular weight of 1950 as a high molecular weight polyol, and 1,4-butanediol as a chain extender
(Abbreviated as BD) and bis (2-hydroxyethyl)-(4-hydroxyphenyl) isocyanurate
Then, 0.235 parts of diphenylmethane diisocyanate (abbreviated as MDI) as an organic polyisocyanate was added thereto, and polyurethane was polymerized. A film melt-molded with a heat press was used as Example 1 for measurement. Table 1 shows the measurement results of various physical properties.

Example 2 4.05 parts of BD, 1.545 parts of BEPI, 20 parts of MDI.
The same operation as in Example 1 was performed except that the amount was changed to 625 parts. Hee
A film melt-molded with a top press machine was subjected to measurement as Example 2. Table 1 shows the measurement results of various physical properties.

Example 3 58.5 parts of PBA as a polymer polyol, 4.365 parts of BD and 0.4635 parts of BEPI as a chain extender, and 19.75 parts of MDI as an organic polyisocyanate were continuously supplied to a twin screw extruder. Then, continuous melt polymerization was performed at 240 ° C. to obtain a polyurethane having an OH group concentration of 42.13 meq / kg. By 1 H-NMR measurement, it was confirmed that an aromatic hydroxyl group in an amount substantially equivalent to the charged BEPI remained in an unreacted state in the obtained polyurethane. This polymer is designated as Component 1.

0.777 parts of isophorone diisocyanate (abbreviated as IPDI) and 0.9205 parts of poly (ε-caprolactone) having a hydroxyl group at both terminals and having a number average molecular weight of 526 (abbreviated as PCL) were added at 80 ° C. to 60 parts. An isocyanate-terminated compound having an NCO concentration of 2062 meq / kg was obtained by stirring for minutes. This is designated as component 2.

Using a kneader, component 1 and component 2 were NCO
The mixture was melt-mixed at a weight ratio of 48.9 to 1 so that the / OH ratio became 1.0 to obtain a crosslinked polymer. A film melt-molded with a heat press was used for measurement as Example 3. Table 1 shows the measurement results of various physical properties.

Example 4 Example 4 was repeated except that 0.4845 parts of bis (2-hydroxyethyl)-(4- (hydroxymethyl) phenyl) isocyanurate (abbreviated as BEMPI) was used instead of 1.545 parts of BEPI. Performed similarly to 1. A film melt-molded with a heat press was used as a measurement in Example 4. Table 1 shows the measurement results of various physical properties.

Comparative Example 1 58.5 parts of PBA was used as a high molecular weight polyol and 4.5 parts of BD were used as a chain extender, and organic polyisocyanate was added thereto.
Then, 20 parts of MDI was added, and the polyurethane was polymerized. Comparative Example 1 of a film melt-formed with a heat press machine
Was used for measurement. Table 1 shows the measurement results of various physical properties.

Comparative Example 2 58.5 parts of PBA as a polymer polyol, 4.365 parts of BD as a chain extender and trimethylolpropane (TM
0.201 part of PDI), 20.2 parts of MDI as an organic polyisocyanate was added thereto, and polyurethane was polymerized. A film melt-molded with a heat press was used as a comparative example 2 for measurement. Table 1 shows the measurement results of various physical properties.
Shown in

[0043]

[Table 1]

Example 5 and Comparative Example 3 The polymer obtained in Example 1 and Comparative Example 1 was melt-spun at a spinning temperature of 210 ° C. and a spinning speed of 500 m / min using a single-screw extruder spinning machine. Elastic fibers were obtained and subjected to measurement as Example 5 and Comparative Example 3, respectively.
Table 2 shows the results of each example.

[0045]

[Table 2]

As is clear from Table 1, the polyurethane of the present invention has a high elastic recovery, and the decrease in the elastic recovery is particularly small even after the heat treatment corresponding to the heat setting step. Further, the polyurethane of the present invention, at a certain temperature or more,
The heat setting rate is as high as a general polyurethane having no crosslinked structure. The same can be said from the elastic fibers in Table 2.

[0047]

According to the present invention, there is provided a polyurethane comprising a high molecular weight polyol, an organic polyisocyanate and a chain extender, wherein one component of the chain extender has a phenol structure,
Or, in the case of an isocyanurate compound having a specific structure having a benzyl alcohol structure, a property having a high heat setting property,
Polyurethane which has both excellent properties of elastic recovery and
Polyurethane elastic fibers can be obtained, which greatly contributes to the industry.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J034 BA08 CA03 CB04 CC12 CC35 CC45 CC61 CC62 CC67 CC69 CD01 CD04 CD05 DA01 DB04 DF03 DF12 DG01 DG05 HA01 HA07 JA01 JA02 QB14 QD04 RA09 4L035 DD14 EE01 EE20 MH03 MH13 MH08

Claims (4)

[Claims] A polyurethane comprising a polymer polyol, an organic polyisocyanate, and a chain extender,
A polyurethane, wherein one component of the chain extender is a compound represented by the following general formula (1). Embedded image (In the above formula, R represents a divalent hydrocarbon structure, a divalent halogenated hydrocarbon structure, or a divalent hydrocarbon in which a hydrocarbon is bonded to an ether bond, an ester bond, an amide bond, a urethane bond, or a urea bond. R ′ represents a direct bond, a divalent hydrocarbon structure, a divalent halogenated hydrocarbon structure, a hydrocarbon is an ether bond, an ester bond, an amide bond, a urethane bond, or a urea. Represents a structure selected from the divalent structure linked to a bond: A1, A2, A3, A4
Is hydrogen, a hydrocarbon group having 6 or less carbon atoms, an alkoxyl group,
Represents a group selected from halogen groups, and may be the same or different. ) 2. An elastic fiber made from the polyurethane of claim 1. 3. A polyurethane comprising a polymer polyol, an organic polyisocyanate, and a chain extender,
A polyurethane, wherein one component of the chain extender is a compound represented by the following general formula (2). Embedded image (In the above formula, R represents a divalent hydrocarbon structure, a divalent halogenated hydrocarbon structure, or a divalent hydrocarbon in which a hydrocarbon is bonded to an ether bond, an ester bond, an amide bond, a urethane bond, or a urea bond. R ′ represents a direct bond, a divalent hydrocarbon structure, a divalent halogenated hydrocarbon structure, a hydrocarbon is an ether bond, an ester bond, an amide bond, a urethane bond, or a urea. Represents a structure selected from the divalent structure linked to a bond: A1, A2, A3, A4
Is hydrogen, a hydrocarbon group having 6 or less carbon atoms, an alkoxyl group,
Represents a group selected from halogen groups, and may be the same or different. B1 and B2 represent a group selected from hydrogen, a hydrocarbon group having 6 or less carbon atoms, and a halogen group, and may be the same or different. ) 4. An elastic fiber made from the polyurethane of claim 2.