WO2018047389A1 - Liquid crystalline textile material and textile product - Google Patents

Abstract

The present invention provides a liquid crystalline textile material having thermal responsiveness at near normal temperature and yet having given or greater strength (durability), focusing on a phenomenon that when a liquid crystalline polyurethane makes phase transition between a crystal phase and an isotropic phase due to a temperature change, the elongation rate thereof changes. A liquid crystalline textile material 11 including a liquid crystalline polyurethane that reversibly stretches between a crystal phase and an isotropic phase in accordance with a temperature change, wherein the elongation rate in the fiber direction is set to 102-200%, with a state of the liquid crystalline polyurethane being most shrunk used as a point of reference (100%), and the shrinkage factor in the fiber direction is set to 98.04-50%, with a state of the liquid crystalline polyurethane being most expanded used as a point of reference (100%).

Description

Liquid crystalline fiber materials and textile products

The present invention relates to a liquid crystalline fiber material containing liquid crystalline polyurethane that reversibly expands and contracts between a liquid crystal phase and an isotropic phase in accordance with a temperature change, and a fiber product using the liquid crystalline fiber material.

A liquid crystalline polymer having a mesogenic group in the molecular structure changes the physical properties of the liquid crystalline polymer when the degree of orientation of the liquid crystal (mesogenic group) changes. Paying attention to such properties, attempts have been made to use liquid crystalline polymers in various applications.

For example, for a highly crystalline liquid crystalline polymer having a specific structure, a technique for obtaining a liquid crystal fiber material having a high degree of orientation by melt spinning a polymer having a certain weight average molecular weight or more is known (for example, Patent Documents). 1). Patent Document 1 discloses a method for producing a liquid crystalline fiber material in which a liquid crystalline polymer is heated to a temperature of (Ti + 30) ° C. or higher to adjust the melt viscosity to allow melt spinning. Ti represents a transition temperature from the liquid crystal phase to the isotropic phase in the liquid crystalline polymer.

JP 2013-82804 A

In order to incorporate liquid crystal fiber materials into daily necessities, especially in the vicinity of room temperature, the liquid crystal fiber material is maintained according to changes in the external environment such as temperature while maintaining the strength (durability) of the liquid crystal fiber material to a certain level or more. It is required to arbitrarily change the mechanical properties and displacement of the conductive fiber material.

In this regard, the liquid crystal polymer used as a raw material for the liquid crystal polymer fiber in Patent Document 1 has a transition temperature (Ti) between the liquid crystal phase and the isotropic phase that is considerably higher than room temperature. ) Is higher than room temperature, and is considered unsuitable for daily necessities such as clothing. In addition, since the liquid crystal polymer fiber of Patent Document 1 is not intended for repeated use, it maintains durability and reliability as a heat-responsive material over a long period of time in an environment with continuous temperature changes. There is a possibility that it cannot be done.

As described above, the conventional liquid crystalline fiber material has not been established the thermal responsiveness that can withstand repeated use while maintaining the strength above a certain level. There is much room for improvement. The present invention has been made in view of the above problems, and pays attention to a phenomenon in which the elongation rate changes when the liquid crystalline polyurethane undergoes a phase transition between the liquid crystal phase and the isotropic phase due to a temperature change. An object of the present invention is to provide a liquid crystalline fiber material having a certain level of strength (durability) while having thermal response. Furthermore, this invention aims at providing the textiles using the said liquid crystalline fiber material.

The characteristic configuration of the liquid crystalline fiber material according to the present invention for solving the above problems is as follows.
A liquid crystalline fiber material comprising a liquid crystalline polyurethane that reversibly expands and contracts between a liquid crystal phase and an isotropic phase according to a temperature change,
Based on the state in which the liquid crystalline polyurethane is most contracted (100%), the elongation in the fiber direction is set to 102 to 200%, or the state in which the liquid crystalline polyurethane is most expanded (100%). ), The shrinkage rate in the fiber direction is set to 98.04 to 50%.

In general, it is known that the structure of a polymer material greatly affects the physical properties, and the phase structure (liquid crystal phase and isotropic property) of the liquid crystalline polyurethane is also used in the liquid crystalline fiber material having thermal responsiveness including liquid crystalline polyurethane. Understanding the correlation between (phase) and mechanical properties is an important clue in designing liquid crystalline fiber materials. Therefore, the present inventors focused on the elongation rate or shrinkage rate of the liquid crystalline polyurethane accompanying the change of the phase structure (phase transition) of the liquid crystalline polyurethane in developing a new liquid crystalline fiber material containing the liquid crystalline polyurethane. Thus, a liquid crystal fiber material meeting the object of the present invention was searched.
According to the liquid crystalline fiber material of this configuration, since it contains liquid crystalline polyurethane that reversibly expands and contracts between the liquid crystal phase and the isotropic phase in response to temperature changes, the thermal responsiveness that combines liquid crystallinity and stretchability It can be used as a material. Here, the elongation rate of the liquid crystalline polyurethane is set to 102 to 200% in the fiber direction, with the standard (100%) of the state in which the liquid crystalline polyurethane is most contracted. Since the shrinkage rate in the fiber direction is set to 98.04-50%, based on the state in which the liquid crystalline polyurethane is most stretched (100%), the amount of displacement usable as a heat-responsive material is secured. However, a certain level of strength (durability) can be maintained between the liquid crystal phase and the isotropic phase.

In the liquid crystalline fiber material according to the present invention,
The liquid crystalline polyurethane is preferably configured as a monofilament or a multifilament.

According to the liquid crystalline fiber material of this configuration, the liquid crystalline polyurethane is configured as a monofilament or a multifilament, and thus can be used for various applications in an appropriate fiber form.

In the liquid crystalline fiber material according to the present invention,
In the fiber direction, the elastic modulus of when the liquid crystalline polyurethane comprising the liquid crystal phase and E _1, when the elastic modulus of the time including the isotropic phase was E _2, satisfying the E 1 _/ E ₂ ≦ 1000 It is preferable.

According to the liquid crystal fiber materials of this configuration, when the liquid crystalline polyurethanes and E ₁ the modulus of elasticity of when a liquid crystal phase, the modulus of the time, including an isotropic phase was _{E 2, E 1 / E 2} ≦ Since it is set to satisfy 1000, when a phase transition occurs between the liquid crystal phase and the isotropic phase, the elastic modulus of the liquid crystalline polyurethane changes up to 1000 times. At this time, the order (entropy) of the molecular structure of the liquid crystalline polyurethane increases or decreases with the phase transition, and the liquid crystalline polyurethane is displaced (stretched / contracted) accordingly. Even when the liquid crystalline polyurethane is displaced, the change in the elastic modulus of the liquid crystalline polyurethane is maintained within 1000 times as described above. As described above, the liquid crystalline fiber material of this configuration has a certain level of strength (durability) between the liquid crystal phase and the isotropic phase, and can greatly change the elastic modulus. It is useful as a material having thermal response utilizing the transition.

In the liquid crystalline fiber material according to the present invention,
In the fiber direction, when rupture stress when the liquid crystalline polyurethane includes the liquid crystal phase is σ ₁ and rupture stress when the isotropic phase is included is σ ₂ , σ ₁ / σ ₂ ≦ 40 is satisfied. It is preferable.

According to the liquid crystalline fiber material of this configuration, when the breaking stress when the liquid crystalline polyurethane contains a liquid crystal phase is σ ₁ and when the breaking stress when the liquid crystalline polyurethane contains an isotropic phase is σ ₂ , σ ₁ / σ ₂ ≦ Therefore, if a phase transition occurs between the liquid crystal phase and the isotropic phase, the breaking stress of the liquid crystalline polyurethane changes up to 40 times. At this time, the order (entropy) of the molecular structure of the liquid crystalline polyurethane increases or decreases with the phase transition, and the liquid crystalline polyurethane is displaced (stretched / contracted) accordingly. Even when the liquid crystalline polyurethane is displaced, the change in the breaking stress of the liquid crystalline polyurethane is maintained within 40 times as described above. As described above, the liquid crystalline fiber material of this configuration has a strength (durability) of a certain level or more between the liquid crystal phase and the isotropic phase, but can greatly change the breaking stress. It is useful as a material having thermal response using

In the liquid crystalline fiber material according to the present invention,
The phase transition temperature (Ti) serving as a boundary between the liquid crystal phase and the isotropic phase is preferably not less than the glass transition temperature (Tg) of the liquid crystalline polyurethane and not more than 100 ° C.

According to the liquid crystalline fiber material of this configuration, since the phase transition temperature (Ti) of the liquid crystalline polyurethane exists between the glass transition temperature (Tg) and 100 ° C., the liquid crystal can be used in a relatively low temperature region including normal temperature. The elastic modulus and breaking stress of the flexible polyurethane are greatly changed, and it becomes a practical liquid crystal fiber material that is easy to use.

In the liquid crystalline fiber material according to the present invention,
The difference between the phase transition temperature (Ti) and the glass transition temperature (Tg) is preferably 20 ° C. or higher.

According to the liquid crystalline fiber material of this configuration, by setting the difference between the phase transition temperature (Ti) and the glass transition temperature (Tg) to 20 ° C. or more, the liquid crystal phase region in which the elastic modulus and the breaking stress are increased is wide. It is a practical liquid crystalline fiber material that is secured and easy to use.

In the liquid crystalline fiber material according to the present invention,
The liquid crystalline polyurethane preferably contains a reaction product of a mesogen group-containing compound having an active hydrogen group, an isocyanate compound, an alkylene oxide and / or a styrene oxide, and a crosslinking agent.

According to the liquid crystalline fiber material of this configuration, when a mesogenic group-containing compound having an active hydrogen group, an isocyanate compound, an alkylene oxide and / or a styrene oxide, and a crosslinking agent react to form a liquid crystalline polyurethane, Since the alkylene oxide and / or styrene oxide acts to lower the thermal stability of the mesogenic group contained in the liquid crystalline polyurethane, the liquid crystalline expression temperature of the liquid crystalline polyurethane is lowered, and the liquid crystalline fiber is solventless at room temperature. The material can be molded.

In the liquid crystalline fiber material according to the present invention,
The cross-linking agent is preferably a polyol having at least three reactive functional groups.

According to the liquid crystalline fiber material of this configuration, since a matrix is densified by using a polyol having at least three reactive functional groups as a crosslinking agent, it is possible to ensure a certain level of strength as a material. . In addition, the polyol having at least three reactive functional groups has less steric hindrance in the molecular structure, so that an excessive change in elastic modulus and breaking stress before and after the phase transition temperature of the liquid crystalline polyurethane is suppressed. Therefore, when the liquid crystalline fiber material undergoes a phase transition from the liquid crystal phase to the isotropic phase, it is possible to reduce deterioration in physical properties of the matrix while maintaining the thermal response.

In the liquid crystalline fiber material according to the present invention,
When the total amount of the mesogenic group-containing compound, the isocyanate compound, the alkylene oxide and / or the styrene oxide, and the crosslinking agent is 100 parts by weight, the amount of the crosslinking agent is 0.1 to 20 parts by weight. It is preferable that

According to the liquid crystalline fiber material of this configuration, since the blending amount of the crosslinking agent in the raw material of the liquid crystalline polyurethane is set to an appropriate range, the mesogenic group in the liquid crystalline polyurethane can move moderately. In addition, the thermal responsiveness and the liquid crystallinity can be expressed with a good balance.

The characteristic configuration of the textile product according to the present invention for solving the above problems is as follows:
A fiber product using any one of the above liquid crystalline fiber materials,
The stretch rate or the shrinkage rate is configured to be locally different.

According to the fiber product of this configuration, since the liquid crystalline fiber material described above is used, the fiber product is useful as a fiber product having a certain level of strength (durability) and excellent thermal response. In addition, since the amount of displacement associated with the phase transition from the liquid crystal phase to the isotropic phase is set to a significant value in the liquid crystalline fiber material that is the raw material, the fiber product of this configuration is capable of minute expansion and contraction such as medical supplies. It can be used from those requiring high performance to those requiring great elasticity such as socks, sportswear, and supporters. Moreover, since it is comprised so that an expansion | extension rate or shrinkage | contraction rate may differ locally, it can utilize as correction | amendment underwear which tightens only the location which wants to clamp | tighten a body locally, and the health clothing goods from which a massage effect is acquired.

FIG. 1 is an explanatory diagram showing a relationship between a phase structure and a modulus of elasticity accompanying a change in temperature for a liquid crystalline fiber material. FIG. 2 is an explanatory view showing the breaking stress due to the difference in the phase structure of the liquid crystalline fiber material. FIG. 3 is an explanatory diagram of a fiber product using a liquid crystalline fiber material.

Hereinafter, embodiments relating to the liquid crystalline fiber material of the present invention and fiber products using the liquid crystalline fiber material will be described. However, the present invention is not intended to be limited to the configurations described in the following embodiments and drawings.

[Composition of liquid crystalline fiber material]
The liquid crystalline fiber material of the present invention contains liquid crystalline polyurethane, and is a liquid crystalline elastomer having both liquid crystallinity and stretchability. The raw material liquid crystalline polyurethane constitutes the matrix of the liquid crystalline fiber material of the present invention and is processed into a fiber form by liquid crystal spinning. Here, in this specification, “matrix” means a main component of a material. Therefore, in addition to the main component, the liquid crystalline fiber material of the present invention includes subcomponents added in a small amount (for example, other polymers, low-molecular substances, fillers, etc.) and minute three-dimensional structures (for example, bubbles, This does not exclude the possibility of including voids and the like.

The liquid crystalline polyurethane is obtained by reacting a mesogen group-containing compound having an active hydrogen group (hereinafter simply referred to as “mesogen group-containing compound”), an isocyanate compound, an alkylene oxide and / or a styrene oxide, and a crosslinking agent. Is generated by When producing the liquid crystalline polyurethane, the alkylene oxide and / or styrene oxide acts to reduce the thermal stability of the mesogenic group contained in the liquid crystalline polyurethane, so the liquid crystalline expression temperature of the liquid crystalline polyurethane is reduced, It becomes possible to mold the liquid crystalline fiber material without solvent at room temperature.

As the mesogen group-containing compound, for example, a compound represented by the following general formula (1) is used.

In the formula, X is a part of the molecular structure of the mesogenic group, and is a single bond forming a part of the adjacent linking group, —N═N—, —CO—, —CH═N—, —CO—O. —, —CH ₂ —, —CH═CH—, or —CO—NH—, and A ₁ and A ₂ independently or together are a cycloalkane having 3 to 8 carbon atoms, a benzene ring, naphthalene, biphenyl, Or a heterocyclic compound thereof, or a compound in which a part thereof is substituted with -Br, -Cl, or -CH ₃ , and Y ₁ and Y ₂ are independently or both of one of the adjacent linking groups. Part of a single bond, —O—, —CO—, —S—, —Se—, or —Te—, and B ₁ and B ₂ independently or together form part of an adjacent linking group A single bond, or — (CH ₂ ) _m —, wherein _m is an integer of 1 to 20. However, the case where Y ₁ and Y ₂ are —O— and B ₁ and B ₂ are a single bond forming a part of the adjacent linking group is excluded. Z ₁ and Z ₂ are end groups having the active hydrogen group, and independently or together, —OH, —SH, —NH ₂ , —COOH, —CHO, —O—CH (OH) —CH ₂ OH or secondary amine. The “single bond forming a part of the adjacent linking group” means a state in which the single bond is shared with a part of the adjacent linking group. For example, in the general formula (1), when Z ₁ is —OH, Y ₁ is —CO—, and B ₁ is a single bond that forms part of an adjacent bonding group, Z ₁ —B ₁ The site of —Y ₁ becomes HO—CO—, and B ₁ that is a single bond is shared with —OH and —CO— on both sides.

As the isocyanate compound, for example, a diisocyanate compound or a trifunctional or higher functional isocyanate compound can be used. Examples of diisocyanate compounds include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate. Aromatic diisocyanates such as p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylylene diisocyanate, and m-xylylene diisocyanate, ethylene diisocyanate, 2,2,4-trimethylhexamethylene-1,6-diisocyanate, 2, Aliphatic diisocyanates such as 4,4-trimethylhexamethylene-1,6-diisocyanate and 1,6-hexamethylene diisocyanate, and 1,4 Cyclohexane diisocyanate, cyclohexane diisocyanate, 4,4'-dicyclohexyl methane diisocyanate, isophorone diisocyanate, and include alicyclic diisocyanates such as norbornane diisocyanate. The above-mentioned diisocyanate compounds may be used alone or in combination of two or more. Examples of trifunctional or higher functional isocyanate compounds include triphenylmethane triisocyanate, tris (isocyanatephenyl) thiophosphate, lysine ester triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,6,11-undecane triisocyanate, Examples thereof include triisocyanates such as 1,8-diisocyanate-4-isocyanate methyloctane and bicycloheptane triisocyanate, and tetraisocyanates such as tetraisocyanate silane. The above trifunctional or higher functional isocyanate compounds may be used singly or as a mixture of plural kinds. As the isocyanate compound, it is possible to use a mixture of the above-mentioned diisocyanate compound and the above-described trifunctional or higher isocyanate compound. The compounding amount of the isocyanate compound is adjusted so as to be 10 to 40% by weight, preferably 15 to 35% by weight, based on all raw materials of the liquid crystalline polyurethane. When the blending amount of the isocyanate compound is less than 10% by weight, it is difficult to continuously mold the liquid crystalline polyurethane because the polymerization by the urethane reaction becomes insufficient. When the blending amount of the isocyanate compound exceeds 40% by weight, the blending amount of the mesogenic group-containing compound in the total raw materials is relatively small, so that the liquid crystallinity of the liquid crystalline polyurethane is lowered.

As the alkylene oxide, for example, ethylene oxide, propylene oxide, or butylene oxide can be used. The above alkylene oxides may be used alone or in combination of two or more. About styrene oxide, you may have substituents, such as an alkyl group, an alkoxyl group, and a halogen, in a benzene ring. As the alkylene oxide, a mixture of the above-mentioned alkylene oxide and the above-mentioned styrene oxide can be used. The blending amount of alkylene oxide and / or styrene oxide is adjusted so that 1 to 10 mol, preferably 2 to 8 mol, of alkylene oxide and / or styrene oxide is added to 1 mol of the mesogen group-containing compound. When the number of added moles of alkylene oxide and / or styrene oxide is less than 1 mole, it is difficult to sufficiently reduce the temperature range in which the liquid crystallinity of the liquid crystalline polyurethane is manifested. It becomes difficult to continuously mold the liquid crystalline polyurethane while reaction-curing the raw materials in the state. When the number of added moles of alkylene oxide and / or styrene oxide exceeds 10 moles, the liquid crystalline polyurethane liquid crystallinity may be difficult to be exhibited.

As the crosslinking agent, for example, a polyol having at least three reactive functional groups (hereinafter, also referred to as “polyol having three or more reactive functional groups”) can be used. When such a polyol is used as a cross-linking agent, the liquid crystalline polyurethane is densified, so that a certain level of strength can be secured as a material. In addition, since polyol has less steric hindrance in its molecular structure, excessive changes in elastic modulus and changes in rupture stress before and after the phase transition temperature of liquid crystalline polyurethane are suppressed (about changes in elastic modulus and changes in rupture stress). Will be explained in detail later). Therefore, when the liquid crystalline fiber material undergoes a phase transition from the liquid crystal phase to the isotropic phase, it is possible to reduce the deterioration of the physical properties of the liquid crystalline polyurethane while maintaining the thermal response. Examples of polyols having at least three reactive functional groups include polyether polyols, polyester polyols, polycarbonate polyols, and high molecular weight polyols having three or more hydroxyl groups (molecular weight of 400 or more) such as polyester polycarbonate polyols, and trimethylolpropane. Glycerin, 1,2,6-hexanetriol, meso-erythritol, pentaerythritol, tetramethylolcyclohexane, methylglucoside, sorbitol, mannitol, dulcitol, sucrose, 2,2,6,6-tetrakis (hydroxymethyl) cyclohexanol, And low molecular weight polyols such as triethanolamine. The above-mentioned polyols may be used alone or in combination of two or more. The blending amount of the crosslinking agent is 0.1 to 20 parts by weight when the total amount of all raw materials (mesogen group-containing compound, isocyanate compound, alkylene oxide and / or styrene oxide, and crosslinking agent) is 100 parts by weight, Preferably, it is adjusted to 0.2 to 18 parts by weight. If it is such a range, the mesogenic group in liquid crystalline polyurethane can move moderately, and heat responsiveness and liquid crystallinity can be expressed with sufficient balance. When the blending amount of the cross-linking agent is less than 0.1 parts by weight, the liquid crystalline polyurethane is not sufficiently cured, so that the matrix itself may flow and heat response may not be obtained. When the blending amount of the cross-linking agent exceeds 20 parts by weight, the cross-linking density of the liquid crystalline polyurethane becomes too high, so that the orientation of the mesogenic group is hindered to make it difficult to develop liquid crystallinity and the thermal response may not be obtained. is there.

The liquid crystalline fiber material is produced, for example, by the following reaction scheme. First, a mesogen group-containing compound is reacted with alkylene oxide and / or styrene oxide to prepare a mesogen group-containing compound to which alkylene oxide and / or styrene oxide is added (hereinafter referred to as “mesogen diol”). A catalyst and a first-stage isocyanate compound are added to the obtained mesogenic diol to obtain a liquid crystalline urethane compound. The first-stage isocyanate compound is preferably added so that the NCO index is 50 to 98. Here, the NCO index is a numerical value obtained by dividing the total number of isocyanate groups of the isocyanate compound by the total number of active hydrogen groups of a polyol that can react with the isocyanate group and multiplying by 100. When the NCO index is less than 50, the molecular weight of the liquid crystalline urethane compound is small, so that the viscosity of the liquid crystalline urethane compound is low and spinning may be difficult. If the NCO index exceeds 98, the crosslink density of the liquid crystalline polyurethane becomes too high with the addition of the first-stage isocyanate compound. However, there is a possibility that the crosslinking reaction hardly occurs. Under the above conditions, the mesogenic groups contained in the obtained liquid crystalline urethane compound can be uniformly dispersed to some extent before crosslinking with a polyol having three or more reactive functional groups. A semi-cured liquid crystalline urethane compound (prepolymer) is obtained by adding a crosslinking agent and a second-stage isocyanate compound to the obtained liquid crystalline urethane compound and kneading while heating. The second-stage isocyanate compound is preferably added so that the NCO index finally becomes 100 to 130. Thereby, an isocyanate group can react with the active hydrogen group of a polyol without excess and deficiency. When this semi-cured liquid crystalline urethane compound is extruded into fibers using an extrusion molding machine, etc., and cured under appropriate conditions, the liquid crystalline urethane compound cures while polymerizing and is formed into a fiber form. Polyurethane (elastomer) is formed. At this time, when the liquid crystalline polyurethane is molded while being stretched at a glass transition temperature (Tg) or higher and a phase transition temperature (Ti) or lower (that is, a temperature at which liquid crystallinity is exhibited), the mesogenic group contained in the liquid crystalline polyurethane is stretched. A high degree of orientation can be obtained. Then, when the liquid crystalline polyurethane is cured in the stretched state, a liquid crystalline fiber material containing the liquid crystalline polyurethane that reversibly expands and contracts between the liquid crystal phase and the isotropic phase according to a temperature change is completed. Since the liquid crystalline fiber material includes liquid crystalline polyurethane that reversibly changes between a liquid crystal phase and an isotropic phase according to a temperature change, the liquid crystalline fiber material has both liquid crystallinity and stretchability. It can be used as a heat-responsive stretch material that reversibly stretches depending on the temperature. In this liquid crystalline fiber material, the mesogenic groups in the liquid crystalline polyurethane are oriented in the stretching direction. When heat is applied, the orientation of the mesogenic groups collapses (becomes irregular) and contracts in the stretching direction, and heat is applied. When it is removed, the orientation of the mesogenic group is restored and exhibits a specific thermal response behavior that extends in the stretching direction.

Incidentally, the orientation of liquid crystalline polyurethane can be evaluated by the degree of orientation of mesogenic groups. In the case where the value of the degree of orientation is large, the mesogenic group is highly oriented in the uniaxial direction. The degree of orientation was determined by measuring the absorbance (0 °, 90 °) of the antisymmetric stretching vibration of the aromatic ether and the methyl group by one-time total reflection measurement (ATR) using a Fourier transform infrared spectrophotometer (FTIR). Absorbance (0 °, 90 °) of symmetric bending vibration is measured and calculated based on the following calculation formula using these absorbances as parameters.
Degree of orientation = (AB) / (A + 2B)
A: Absorbance of reverse symmetrical stretching vibration of aromatic ether measured at 0 ° / Absorbance of symmetrical bending vibration of methyl group measured at 0 ° B: Reverse of aromatic ether measured at 90 ° Absorbance of symmetrical stretching vibration / absorbance of symmetrical bending vibration of methyl group measured at 90 °

The liquid crystalline polyurethane obtained by the above reaction scheme can be used as it is as a matrix of the liquid crystalline fiber material of the present invention, but it can be used by adding a small amount of subcomponents to the liquid crystalline polyurethane or by dispersing bubbles. Is also possible. Examples of subcomponents that can be added to liquid crystalline polyurethane include organic fillers, inorganic fillers, reinforcing agents, thickeners, release agents, excipients, coupling agents, flame retardants, flame retardants, pigments, colorants, Examples include odorants, antibacterial agents, antifungal agents, antistatic agents, ultraviolet ray preventing agents, and surfactants. Moreover, it is also possible to add another polymer and a low molecular substance as a subcomponent. The liquid crystalline polyurethane to which the subcomponent is added is provided with the function of the subcomponent and can be used in various situations.

Examples of a method for dispersing bubbles in liquid crystalline polyurethane include a method in which a foaming agent is mixed with a raw material of liquid crystalline polyurethane and the foaming agent is foamed during the curing reaction of the liquid crystalline polyurethane. In this case, for example, sodium bicarbonate can be used as the foaming agent. Further, as another method for dispersing bubbles in liquid crystalline polyurethane, for example, a mechanical floss method in which bubbles are mixed in liquid crystalline polyurethane by mixing the raw material while containing air in the raw material of liquid crystalline polyurethane, liquid crystal Examples include a method of dispersing the hollow filler in the liquid crystalline polyurethane by mixing the hollow filler with the raw material of the conductive polyurethane. The liquid crystalline fiber material in which bubbles are dispersed in the liquid crystalline polyurethane has increased heat insulation properties due to the bubbles, and thus can be used even in an environment with a large temperature change. Further, since the liquid crystalline fiber material is reduced in weight by including bubbles in the liquid crystalline polyurethane, it can be suitably applied to a transport machine such as an automobile.

The fiber form of the liquid crystalline fiber material may be either monofilament or multifilament. The monofilament can be obtained by processing liquid crystalline polyurethane into a fiber form by liquid crystal spinning. By extruding a kneaded product obtained by melting the liquid crystalline urethane compound obtained from the mesogenic diol and the first-stage isocyanate compound and the second-stage isocyanate compound into a fiber by an extrusion molding machine or the like, fibers are obtained. A liquid crystalline polyurethane (elastomer) is produced. A monofilament is obtained by winding this liquid crystalline polyurethane on a roll while uniaxially stretching and curing for a predetermined period. A multifilament is obtained by bundling several to hundreds of monofilaments. The liquid crystalline fiber material configured as a monofilament or a multifilament can be used for various applications depending on the fiber form.

[Physical properties of liquid crystalline fiber materials]
The liquid crystalline fiber material of the present invention is characterized in that the physical properties of the liquid crystalline polyurethane are greatly different between a state containing a liquid crystal phase and a state containing an isotropic phase. In the following embodiments, the elongation rate or shrinkage rate of the liquid crystalline polyurethane accompanying the phase transition and the influence of the phase structure of the liquid crystalline polyurethane on the mechanical properties (particularly the elastic modulus and breaking stress) will be described.

(Elongation rate or shrinkage rate of liquid crystalline fiber material)
In the liquid crystalline fiber material, a liquid crystal phase is developed by aligning the mesogenic groups of the liquid crystalline polyurethane below the phase transition temperature (Ti). Since the mesogenic group in the liquid crystalline fiber material is oriented in the stretching direction (that is, the fiber direction), the liquid crystalline fiber material itself is stretched along the stretching direction. On the other hand, above the phase transition temperature (Ti), the orientation of the mesogenic group of the liquid crystalline polyurethane collapses (is irregular) and an isotropic phase appears. Since the orientation of the mesogen groups in the liquid crystalline fiber material is irregular, the liquid crystalline fiber material itself contracts along the stretching direction as compared to when it is aligned along the stretching direction. The orientation of the mesogenic group is imparted to the liquid crystalline fiber material by liquid crystal spinning as described above. For the liquid crystalline fiber material, for example, the elongation ratio in the fiber direction is set to 102 to 200% with reference to the state in which the liquid crystalline polyurethane is most contracted (100%). The liquid crystalline fiber material set to such an elongation rate has a certain level of strength (durability) between the liquid crystal phase and the isotropic phase while ensuring a displacement that can be used as a heat-responsive material. Therefore, it is useful as a material having thermal response utilizing phase transition. For example, in medical supplies and precision instruments used in the body, there are cases where minute expansion and contraction is required so as not to place a burden on an organ or other members. In addition, in socks, sportswear, supporters, etc., there is a case where large expansion / contraction is required that is loose when worn on the body, fits to the body after being worn, and presses as necessary. Since the liquid crystalline fiber material has an elongation rate set to 102 to 200%, it can be suitably used as a material for various textile products. When the elongation rate is less than 102%, the fiber product using the liquid crystalline fiber material hardly expands and contracts, so that it is not suitable as a material having substantially thermal response. When the elongation rate exceeds 200%, the fiber product using the liquid crystalline fiber material is greatly deformed, and thus there is a possibility that the durability may be lowered due to repeated expansion and contraction. The elongation ratio of the liquid crystalline fiber material is based on the state in which the liquid crystalline polyurethane is most contracted (100%), but the state in which the liquid crystalline polyurethane is most expanded (100%). %), It can also be expressed as the shrinkage of the liquid crystalline fiber material. In this case, the elongation rate of 102 to 200% corresponds to the shrinkage rate of 98.04 to 50%. In order for the fiber material to exhibit significant stretchability, the orientation degree of the liquid crystalline polyurethane is preferably 0.05 or more, and more preferably 0.1 or more.

(Relationship between phase structure and elastic modulus of liquid crystalline fiber material)
FIG. 1 is an explanatory diagram showing the relationship between the phase structure and the elastic modulus associated with a temperature change in the liquid crystalline fiber material of the present invention. When the liquid crystalline fiber material in a low temperature state is heated to continuously increase the temperature, the elastic modulus of the liquid crystalline polyurethane decreases with the glass transition temperature (Tg) as a boundary. However, in the region exceeding the glass transition temperature (Tg), the subsequent elastic modulus is maintained. This is because, as shown in the image in the broken circle (a), a liquid crystal phase appears due to the orientation of the mesogenic group of the liquid crystalline polyurethane above the glass transition temperature (Tg), and the mesogenic group is stressed in the orientation direction. It is because it can bear. When the liquid crystalline fiber material is further heated from this state, the elastic modulus of the liquid crystalline polyurethane is remarkably lowered at the phase transition temperature (Ti). This is because, as shown in the image in the broken-line circle (b), the orientation of the mesogenic group of the liquid crystalline polyurethane collapses to cause a phase transition from the liquid crystal phase to the isotropic phase, thereby reducing the stress bearing ability of the mesogenic group. is there. Here, when the liquid crystalline polyurethanes and E ₁ the modulus of elasticity of when a liquid crystal phase, the modulus of the time, including an isotropic phase was E _2, liquid crystal fiber materials of the present invention, the following dynamic conditions 1:
<Mechanical conditions _{1>: E 1 / E 2} ≦ 1000
Designed to meet. Modulus E ₁ is, for example, can be adopted initial tensile resistance degree was measured at the phase transition temperature (Ti) from 10 ~ 30 ° C. lower temperature of the liquid crystalline polyurethane (deemed Young's modulus). Modulus E ₂ are, for example, can be adopted initial tensile resistance degree were measured at 10 ~ 30 ° C. higher temperature than the phase transition temperature of the liquid crystalline polyurethane (Ti) a (deemed Young's modulus). The initial tensile resistance may be a Young's modulus E obtained from a tensile test or a storage elastic modulus E ′ obtained from a dynamic viscoelasticity measurement. In the following description, the elastic modulus E will be described as the initial tensile resistance E.

In the liquid crystalline fiber material satisfying the above-mentioned mechanical condition 1, when a phase transition occurs between the liquid crystal phase and the isotropic phase, the initial tensile resistance E of the liquid crystalline polyurethane changes up to 1000 times. Specifically, when the phase transition from the liquid crystal phase to the isotropic phase, the initial tensile resistance of the liquid crystalline polyurethane can be reduced to 1/1000 times. At this time, since the mesogenic groups that have been aligned with the phase transition become irregular, the order (entropy) of the molecular structure of the liquid crystalline polyurethane is increased, and the liquid crystalline fiber material is in the alignment direction (that is, the fiber direction). It shrinks and is displaced so as to extend in the non-orientation direction (that is, the fiber radial direction). Conversely, when the phase transition from the isotropic phase to the liquid crystal phase, the initial tensile resistance of the liquid crystalline polyurethane can increase up to 1000 times. At this time, the disordered mesogen groups are aligned again with the phase transition, so that the molecular structure order (entropy) of the liquid crystalline polyurethane is lowered, and the liquid crystalline fiber material extends in the alignment direction and in the non-alignment direction. Displace to shrink. In the above mechanical condition 1, the lower limit value of E ₁ / E ₂ is not particularly defined, but as understood from FIG. 1, the initial tensile resistance E ₁ is smaller than the initial tensile resistance E _2. Therefore, it is appropriate to set E ₁ / E ₂ to a value larger than 1. Therefore, even if the liquid crystalline polyurethane is displaced along with the phase transition, the change in the initial tensile resistance of the liquid crystalline polyurethane is maintained within 1000 times as described above. As described above, the liquid crystalline fiber material of the present invention can greatly change the initial tensile resistance while having a certain level of strength (durability) between the liquid crystal phase and the isotropic phase. It is useful as a material having thermal response utilizing phase transition.

In order for the liquid crystalline fiber material to have a practical strength, it is preferable that E ₁ and E ₂ defined above have a predetermined value or more. In the present invention, in particular, E ₂ measured at a temperature higher than the phase transition temperature (Ti) of the liquid crystalline polyurethane is set to 0.01 cN / dtex or more, preferably 0.02 cN / dtex or more. If E ₂ is 0.01cN / dtex or more, it can be suitably used as a practical liquid crystal fiber materials with sufficient durability. Note that the value of E ₁ is E ₁ ≦ 10 cN / dtex in the case of E ₂ = 0.01 cN / dtex, for example, from the mechanical condition 1 described above.

(Relationship between phase structure of liquid crystalline fiber material and breaking stress)
FIG. 2 is an explanatory diagram (stress-strain curve) showing the breaking stress due to the difference in phase structure for the liquid crystalline fiber material of the present invention. Since the liquid crystalline fiber material of the present invention is an elastomer, for example, when a tensile stress is applied in the fiber direction, the liquid crystalline fiber material expands in the fiber direction, and when the tensile stress is further increased, the liquid crystalline fiber material further expands accordingly. When the tensile stress exceeds the limit value, the liquid crystalline fiber material is broken. The stress when the liquid crystalline fiber material breaks is the breaking stress. When the liquid crystalline fiber material of the present invention is in a state in which the liquid crystalline polyurethane contains a liquid crystal phase, as shown in FIG. 2 (a), the liquid crystalline phase is expressed by the orientation of the mesogenic groups of the liquid crystalline polyurethane. Since the mesogenic group can bear the stress in the direction, it has a relatively high breaking stress. On the other hand, when the liquid crystalline polyurethane is in a state containing an isotropic phase, as shown in FIG. 2 (b), the phase transition from the liquid crystal phase to the isotropic phase occurs due to the disruption of the orientation of the mesogenic group of the liquid crystalline polyurethane. Since the stress bearing ability of the base is reduced, the breaking stress is significantly reduced. Here, when the breaking stress when the liquid crystalline polyurethane contains a liquid crystal phase is σ ₁ and the breaking stress when the liquid crystalline polyurethane contains an isotropic phase is σ ₂ , the liquid crystalline fiber material of the present invention has the following mechanical conditions: 2:
<Mechanical condition 2>: σ ₁ / σ ₂ ≦ 40
Designed to meet. As the breaking stress σ ₁ , for example, a breaking stress measured at a temperature lower by 10 to 30 ° C. than the phase transition temperature (Ti) of the liquid crystalline polyurethane can be employed. As the breaking stress σ ₂ , for example, a breaking stress measured at a temperature 10 to 30 ° C. higher than the phase transition temperature (Ti) of the liquid crystalline polyurethane can be adopted.

When a phase transition occurs between the liquid crystal phase and the isotropic phase, the liquid crystalline fiber material satisfying the above-described mechanical condition 2 changes the breaking stress σ of the liquid crystalline polyurethane by a maximum of 40 times. Specifically, when the phase transition from the liquid crystal phase to the isotropic phase, the breaking stress of the liquid crystalline polyurethane can be reduced to 1/40 times. At this time, the mesogenic groups that have been aligned with the phase transition become irregular, so the order (entropy) of the molecular structure of the liquid crystalline polyurethane increases, and the liquid crystalline polyurethane shrinks in the alignment direction (that is, the fiber direction). At the same time, it is displaced so as to extend in the non-oriented direction (that is, the radial direction of the fiber). On the contrary, when the phase transition from the isotropic phase to the liquid crystal phase, the breaking stress of the liquid crystalline polyurethane can increase up to 40 times. At this time, the disordered mesogenic groups are realigned with the phase transition, so that the order (entropy) of the molecular structure of the liquid crystalline polyurethane is lowered, and the liquid crystalline polyurethane stretches in the alignment direction and shrinks in the non-alignment direction. Displaces like In the above mechanical condition 2, the lower limit value of σ ₁ / σ ₂ is not particularly defined, but the breaking stress is similar to the relationship between the initial tensile resistance degree E ₁ and the initial tensile resistance degree E ₂ described above. Since it is difficult to realistically think that σ ₁ is smaller than the breaking stress σ ₂ , it is appropriate to set σ ₁ / σ ₂ to a value larger than 1. Therefore, even if the liquid crystalline polyurethane is displaced along with the phase transition, the change in the breaking stress of the liquid crystalline polyurethane is maintained within 40 times as described above. As described above, the liquid crystalline fiber material of the present invention has a strength (durability) of a certain level or more between the liquid crystal phase and the isotropic phase, and can greatly change the breaking stress. It is useful as a material having thermal response utilizing the transition.

In order for the liquid crystalline fiber material to have a practical strength, it is preferable that σ ₁ and σ ₂ defined above have a predetermined value or more. In the present invention, in particular, σ ₂ measured at a temperature higher than the phase transition temperature (Ti) of the liquid crystalline polyurethane is set to be 0.01 cN / dtex or more, preferably 0.02 cN / dtex or more. When σ ₂ is 0.01 cN / dtex or more, it can be suitably used as a practical liquid crystalline fiber material having sufficient durability. Note that the value of σ ₁ is σ ₁ ≦ 0.4 cN / dtex in the case of σ ₂ = 0.01 cN / dtex, for example, from the above-described mechanical condition 2.

(Glass transition temperature (Tg) and phase transition temperature (Ti) of liquid crystalline polyurethane)
In order for the liquid crystalline fiber material to be usable in a temperature range including normal temperature, it is necessary to select a liquid crystalline polyurethane having an appropriate glass transition temperature (Tg) and phase transition temperature (Ti) as a matrix. In the present invention, a liquid crystalline polyurethane having a phase transition temperature (Ti) of not less than the glass transition temperature (Tg) of the liquid crystalline polyurethane and not more than 100 ° C. is preferably used. Furthermore, the difference between the phase transition temperature (Ti) and the glass transition temperature (Tg) is preferably 20 ° C. or higher, and more preferably 25 ° C. or higher. The liquid crystalline fiber material containing such a liquid crystalline polyurethane has a liquid crystal phase in which the initial tensile resistance and breaking stress of the liquid crystalline polyurethane greatly change in a relatively low temperature region including normal temperature, and the initial tensile resistance increases. Since a wide area is secured, a practical liquid crystalline fiber material having excellent thermal response and good usability is obtained.

Mechanical condition 1 regarding the initial tensile resistance E ₁ and initial tensile resistance E _2, mechanical condition ₂ regarding the breaking stress σ ₁ and breaking stress σ _2, and the glass transition temperature (Tg) and phase transition described above. A liquid crystalline polyurethane that satisfies the temperature (Ti) and is preferable as a raw material of the liquid crystalline fiber material of the present invention is the liquid crystalline polyurethane described in the above-mentioned item of “Composition of liquid crystalline fiber material”, a mesogenic group-containing compound, It is produced by reacting an isocyanate compound, alkylene oxide and / or styrene oxide, and a crosslinking agent. Preferred physical property values of the liquid crystalline polyurethane usable in the present invention are exemplified below.
・ Glass transition temperature (Tg)  : -30 ~ 60 ℃
-Phase transition temperature (Ti)  : 0 to 100 ° C
Initial tensile resistance E _{1 at} −30 to 60 ° C .: 2 to 25 cN / dtex
Initial tensile resistance E _{2 at} 0 to 100 ° C .: 0.01 to 5 cN / dtex
Breaking stress σ _{1 at} −30 to 60 ° C .: 0.06 to 1.6 cN / dtex
Breaking stress σ _{2 at} 0 to 100 ° C .: 0.01 to 0.6 cN / dtex

[Uses of liquid crystalline fiber materials]
The liquid crystalline fiber material of the present invention can be applied to various uses by utilizing the liquid crystallinity and stretchability of liquid crystalline polyurethane. Such an application example will be described.

FIG. 3 is an explanatory view of a fiber product using the liquid crystalline fiber material of the present invention. In FIG. 3, a sock 10 is shown as an example of a clothing product.

The sock 10 includes an upper step portion 12 that mainly covers the shin, a middle step portion 13 that mainly covers the ankle, and a lower step portion 14 that mainly covers the toes from the toes, and is configured to have different elongation rates. The upper step portion 12, the middle step portion 13, and the lower step portion 14 are knitted as chain stitches of fibers 11 made of multifilaments obtained by liquid crystal spinning of the liquid crystalline fiber material of the present invention. The upper stage part 12, the middle stage part 13, and the lower stage part 14 are configured to have different elongation rates, and the middle stage part 13, the upper stage part 12, and the lower stage part 14 are set so that the elongation rate increases in this order.

The liquid-spun fibers 11 have excellent liquid crystallinity because the molecular chains of liquid crystalline polyurethane are highly oriented in the fiber length direction. As shown in FIG. 3 (a), the sock 10 is in an environment lower than the phase transition temperature (Ti) of the liquid crystalline polyurethane, and the liquid crystalline fiber material constituting the fiber 11 is liquid crystal as shown in the image in the broken line circle. In the state containing the phase, since the fibers 11 are elongated, for example, the knitted fabric constituting the upper step portion 12 and the middle step portion 13 is in a relatively loose state. For this reason, the user can easily wear the socks 10 on the foot. After the user wears the sock 10, when the sock 10 is warmed by the body temperature of the user and exceeds the phase transition temperature (Ti) of the liquid crystalline polyurethane, as shown in the image in the broken line circle of FIG. The liquid crystalline fiber material constituting the fiber 11 includes an isotropic phase, and the fiber 11 contracts accordingly. As the fiber 11 contracts, the upper step portion 12 and the middle step portion 13 are contracted, and the sock 10 fits the user's foot. Here, if the upper step portion 12 and the middle step portion 13 are set at different elongation rates, not only will they fit the user's foot, but also the pressure will be stepwise depending on the location of the user's foot as necessary. Can be granted. In the case of this application example, since the extension rate of the middle step portion 13 is set larger than that of the upper step portion 12, the ankle covered by the middle step portion 13 from the outside is compared with the shin covered by the upper step portion 12. It is strongly squeezed. Since the lower step portion 14 has a smaller elongation rate than the upper step portion 12 and the middle step portion 13, compression from the outside is weakened. Thus, by giving strength to the compression, blood flow in the user's foot can be effectively promoted. In particular, if the phase transition temperature (Ti) of the liquid crystalline polyurethane used for the fiber 11 is set to around body temperature (about 35 to 37 ° C.), for example, from a material that requires microstretchability such as medical supplies, socks It can be suitably used as a material for various textile products, such as sportswear, supporters and the like that require great stretchability. Moreover, since it is comprised so that an expansion | extension rate or shrinkage | contraction rate may differ locally, it can utilize as correction | amendment underwear which tightens only the location which wants to clamp | tighten a body locally, and the health clothing goods from which a massage effect is acquired.

In order to confirm the usefulness of the liquid crystalline fiber material of the present invention, liquid crystalline fiber materials containing various liquid crystalline polyurethanes were prepared by changing the composition of the raw materials, and their characteristics were evaluated. Hereinafter, it demonstrates as an Example of a fiber material.

[Preparation of liquid crystalline fiber material]
Liquid crystalline polyurethane materials were synthesized according to the conditions of the present invention and spun to obtain liquid crystalline fiber materials (Examples 1 to 5). In the following examples, the unit of the blending amount of each raw material of liquid crystalline polyurethane is “g”, but the present invention can be scaled up at an arbitrary magnification. That is, the unit of the blending amount of each raw material of the liquid crystalline polyurethane can be read as “parts by weight”.

<Example 1>
BH6 (500 g), potassium hydroxide (19.0 g) as a mesogen group-containing compound having an active hydrogen group, and N, N-dimethylformamide (3000 ml) as a solvent are mixed in a reaction vessel and further mixed. As a propylene oxide, 2 equivalents of 1 mol of BH6 were added, and the mixture was reacted at 120 ° C. for 2 hours under pressure (addition reaction). Next, oxalic acid (15.0 g) was added to the reaction vessel to stop the addition reaction, insoluble salts in the reaction solution were removed by suction filtration, and N, N-dimethylformamide in the reaction solution was further reduced in pressure. By removing by a distillation method, mesogenic diol A was obtained. A synthesis scheme of mesogenic diol A is shown in Formula (2). In addition, the mesogen diol A shown in Formula (2) is typical, and may contain various structural isomers.

Next, mesogenic diol A (500 g), triethylenediamine as a catalyst (trade name “TEDA (registered trademark) -L33” manufactured by Tosoh Corporation) (5 g), and 1,6-hexamethylene as the first-stage isocyanate compound Diisocyanate (158 g) was mixed and heated at 100 ° C. for 2 hours to obtain liquid crystalline urethane compound A. The first-stage isocyanate compound was added so that the NCO index was 83. Next, the liquid crystalline urethane compound A is filled in a preheated extrusion molding machine and melted. Using a side feeder, a trimethylolpropane (9 g) as a crosslinking agent and 1,6-hexamethylene diisocyanate as a second-stage isocyanate compound are used. (45 g) was added and the kneaded product was extruded into a fiber while being kneaded at 100 ° C. The second-stage isocyanate compound was added so that the NCO index was finally 107. When the total amount of raw materials (mesogenic diol A, isocyanate compound, and crosslinking agent) was 100 parts by weight, the content of trimethylolpropane as a crosslinking agent was 1.3 parts by weight. The extruded fiber was wound up at 20 ° C. while being uniaxially stretched so that the draw ratio was 2 times. The wound fiber was cured at room temperature for 24 hours to obtain a liquid crystalline fiber material of Example 1 in which liquid crystals (mesogenic groups) were aligned.

<Example 2>
The amount of trimethylolpropane is 18.5 g, the amount of 1,6-hexamethylene diisocyanate is 160 g (NCO index is 77) as the first-stage isocyanate compound, and the amount of 1,6- The amount of hexamethylene diisocyanate was 57 g (the final NCO index was 105). The content of trimethylolpropane as a crosslinking agent was 2.5 parts by weight with respect to 100 parts by weight of the raw material. The other raw materials, the blending amount thereof, the reaction conditions, the stretching conditions, and the curing conditions were the same as in Example 1, and the liquid crystalline fiber material of Example 2 was obtained.

<Example 3>
The amount of trimethylolpropane is 1.5 g, the amount of 1,6-hexamethylene diisocyanate is 150 g as the first-stage isocyanate compound (NCO index is 86), and the amount of 1,6- The amount of hexamethylene diisocyanate was 27 g (the final NCO index was 101). The content of trimethylolpropane as a crosslinking agent was 0.22 parts by weight with respect to 100 parts by weight of the raw material. The other raw materials, the blending amount thereof, the reaction conditions, the stretching conditions, and the curing conditions were the same as in Example 1, and the liquid crystalline fiber material of Example 3 was obtained.

<Example 4>
150 g of polyether polyol (trade name “EXCENOL (registered trademark) 400MP”, manufactured by Asahi Glass Co., Ltd.) is blended as a crosslinking agent, and the blending amount of 1,6-hexamethylene diisocyanate is 173 g as the first-stage isocyanate compound (NCO index was 58), and the compounding amount of 1,6-hexamethylene diisocyanate as the second-stage isocyanate compound was 132 g (final NCO index was 102). The content of the polyether polyol as a crosslinking agent was 16 parts by weight with respect to 100 parts by weight of the raw material. The other raw materials, the blending amounts thereof, the reaction conditions, the stretching conditions, and the curing conditions were the same as in Example 1, and the liquid crystalline fiber material of Example 4 was obtained.

<Example 5>
BH6 (500 g), potassium hydroxide (19.0 g) as a mesogen group-containing compound having an active hydrogen group, and N, N-dimethylformamide (3000 ml) as a solvent are mixed in a reaction vessel and further mixed. 7 equivalents of propylene oxide to 2 moles of BH6 (ie, 3.5 equivalents to 1 mole of BH6) and these mixtures were reacted under pressure at 120 ° C. for 2 hours ( Addition reaction). Next, oxalic acid (15.0 g) was added to the reaction vessel to stop the addition reaction, insoluble salts in the reaction solution were removed by suction filtration, and N, N-dimethylformamide in the reaction solution was further reduced in pressure. By removing by a distillation method, mesogenic diol B was obtained. A synthesis scheme of mesogenic diol B is shown in Formula (3). In addition, the mesogen diol B shown in Formula (3) is typical, and may contain various structural isomers.

Next, mesogenic diol B (500 g), triethylenediamine as a catalyst (trade name “TEDA (registered trademark) -L33” manufactured by Tosoh Corporation) (5 g), and 1,6-hexamethylene as the first-stage isocyanate compound Diisocyanate (142 g) was mixed and heated at 100 ° C. for 2 hours to obtain liquid crystalline urethane compound B. The first-stage isocyanate compound was added so that the NCO index was 90. Next, this liquid crystalline urethane compound B is filled in a preheated extruder and melted, and a side feeder is used to crosslink trimethylolpropane (9 g) and 1,6-hexamethylene diisocyanate as the second-stage isocyanate compound. (35 g) was added and the kneaded product was extruded into a fiber while kneading at 100 ° C. The second-stage isocyanate compound was added so that the NCO index was finally 112. When the total amount of raw materials (mesogenic diol B, isocyanate compound, and crosslinking agent) was 100 parts by weight, the content of trimethylolpropane as a crosslinking agent was 1.3 parts by weight. The extruded fiber was wound up at 20 ° C. while being uniaxially stretched so that the draw ratio was 2 times. The wound fiber was cured at room temperature for 24 hours to obtain a liquid crystalline fiber material of Example 5 in which liquid crystals (mesogenic groups) were aligned.

<Comparative Example 1>
The amount of trimethylolpropane is 0.2 g, the amount of 1,6-hexamethylene diisocyanate is 147 g as the first stage isocyanate compound (NCO index is 85), and the amount of 1,6- The amount of hexamethylene diisocyanate was 29 g (the final NCO index was 102). The content of trimethylolpropane as a crosslinking agent was 2.5 parts by weight with respect to 100 parts by weight of the raw material. The content of trimethylolpropane, which is a crosslinking agent, was 0.03 parts by weight with respect to 100 parts by weight of the raw material. The other raw materials, the blending amount thereof, the reaction conditions, the stretching conditions, and the curing conditions were the same as in Example 1, and the fiber material of Comparative Example 1 was obtained.

<Comparative example 2>
300 g of polyether polyol is blended as a crosslinking agent, the amount of 1,6-hexamethylene diisocyanate is 437 g as the first stage isocyanate compound (NCO index is 103), and 1,6-hexa is blended as the second stage isocyanate compound. The blending amount of methylene diisocyanate was 30 g (the final NCO index was 110). The content of trimethylolpropane as a crosslinking agent was 2.5 parts by weight with respect to 100 parts by weight of the raw material. The content of the polyether polyol as a crosslinking agent was 24 parts by weight with respect to 100 parts by weight of the raw material. The other raw materials, the blending amount thereof, the reaction conditions, the stretching conditions, and the curing conditions were the same as in Example 4, and the fiber material of Comparative Example 2 was obtained.

[Characteristic measurement of liquid crystalline fiber material]
In order to confirm the properties (physical properties) of the liquid crystalline fiber materials of Examples 1 to 5, glass transition temperature (Tg), phase transition temperature (Ti), liquid crystallinity, elongation rate, initial tensile resistance, breaking stress, and fineness Was measured. The measurement method and measurement conditions for each measurement item will be described below.

<Glass transition temperature (Tg), phase transition temperature (Ti)>
Using a differential scanning calorimeter [DSC] (X-DSC 7000, manufactured by Hitachi High-Tech Science Co., Ltd.), the glass transition temperature (Tg) and the phase transition temperature (Ti) of each sample were measured. About the temperature increase rate at the time of a measurement, it was 20 degrees C / min.

<Liquid crystal>
Each sample was observed with a polarizing microscope (manufactured by Nikon Corporation, LV-100POL) to confirm the presence or absence of liquid crystallinity. Furthermore, the presence or absence of liquid crystallinity was also confirmed from the measurement results of a differential scanning calorimeter [DSC] (Hitachi High-Tech Science Co., Ltd., X-DSC 7000).

<Elongation rate>
For each sample, the change in size in the alignment direction (change in the length of the sample) generated with the phase transition between the liquid crystal phase and the isotropic phase was measured on a scale. In the measurement, the elongation percentage in the fiber direction was calculated based on the state (100%) in which the liquid crystalline polyurethane was most contracted (in this example, the shortest length in the fiber direction of the liquid crystalline fiber material).

<Initial tensile resistance>
The storage elastic modulus E ′ of each sample was measured using a dynamic viscoelasticity measuring device (manufactured by Ueshima Seisakusho Co., Ltd., fully automatic viscoelasticity analyzer VR-7110). The measurement conditions were a heating rate of 2 ° C./min, a measurement mode of tensile mode, a strain of 2%, and a frequency of 10 Hz. For each sample, the storage elastic modulus E ′ at a temperature 20 ° C. lower than the phase transition temperature (Ti) is the initial tensile resistance E _1, and the storage elastic modulus E ′ at a temperature 20 ° C. higher than the phase transition temperature (Ti) is the initial tensile strength. was the resistance of _{E 2.}

<Breaking stress>
Each sample was measured according to JIS L 1013 using a tensile tester (manufactured by Shimadzu Corporation, precision universal testing machine Autograph AG-X). For each sample, the breaking stress σ at a temperature about 20 ° C. lower than the phase transition temperature (Ti) is defined as the breaking stress σ _1, and the breaking stress σ at a temperature about 20 ° C. higher than the phase transition temperature (Ti) is defined as the breaking stress σ ₂ . .

<Fineness>
The fineness of each sample was measured according to JIS L 1013.

The measurement results for each sample are summarized in Table 1 below.

The liquid crystalline fiber materials of Examples 1 to 5 are those having a fineness of 149 to 160 dtex. As the liquid crystalline polyurethane undergoes a phase transition from the liquid crystal phase to the isotropic phase, the size in the alignment direction (fiber length) is increased. It decreased (shrinked). When the liquid crystalline polyurethane was returned from the isotropic phase to the liquid crystal phase, the fiber length increased (stretched). Thus, the liquid crystalline fiber materials of Examples 1 to 5 exhibited the property of reversibly expanding and contracting between the liquid crystal phase and the isotropic phase in accordance with the temperature change. When the fiber length when the liquid crystalline polyurethane in which the liquid crystalline fiber material is most contracted is in the isotropic phase is 100%, the fiber length (elongation rate) when the liquid crystalline polyurethane is in the liquid crystal phase is 103 to 119%. Met. Incidentally, when this measurement result is converted into a shrinkage rate, when the fiber length when the liquid crystalline polyurethane is in the liquid crystal phase is 100%, the fiber length (shrinkage rate) when the liquid crystalline polyurethane is in the isotropic phase is 97. 0.08-84.03%. As described above, it was confirmed that the liquid crystalline fiber materials of Examples 1 to 5 exhibited a displacement amount usable as a heat responsive material. The liquid crystalline fiber materials of Examples 1 to 5 all have an initial tensile resistance E ₂ of 0.01 cN / tdex or more, and the ratio of the initial tensile resistance E ₁ and the initial tensile resistance E ₂ (E ₁ / E ₂ ) was 6.32 to 875, and the above-mentioned mechanical condition 1 was satisfied. In all of the liquid crystalline polyurethanes of Examples 1 to 5, the breaking stress σ ₂ is 0.01 cN / tdex or more, and the ratio of the breaking stress σ ₁ to the breaking stress σ ₂ (σ ₁ / σ ₂ ) is 4.17. 22.5, which satisfies the above-mentioned mechanical condition 2. Thus, the liquid crystalline polyurethanes of Examples 1 to 5 have a certain level of strength (durability) between the liquid crystal phase and the isotropic phase, but the initial tensile resistance and breaking stress due to the phase transition. It has been confirmed that can vary greatly. Therefore, the liquid crystalline fiber material containing the liquid crystalline polyurethane of the present invention has a thermal response and a certain level of strength (durability) and is useful as a material having both liquid crystallinity and stretchability. Was suggested.

In contrast, the fiber material of Comparative Example 1, the initial tensile resistance degree _{E 1} and the initial tensile ratio of the resistance of _{E 2 (E 1 / E 2} ) is 1400, which do not meet the mechanical condition 1 above Met. Further, the fiber material of Comparative Example 1 had a ratio (σ ₁ / σ ₂ ) between the breaking stress σ ₁ and the breaking stress σ ₂ of 42.1 and did not satisfy the mechanical condition 2 described above. The fiber material of Comparative Example 1 was confirmed to have liquid crystallinity, but did not exhibit the property of reversibly expanding and contracting between the liquid crystal phase and the isotropic phase in accordance with temperature changes. Moreover, the fiber material of the comparative example 2 did not express liquid crystallinity, and the stretchability according to the temperature change was not confirmed.

The liquid crystalline fiber material and fiber product of the present invention utilize the excellent thermal responsiveness, stretchability, elastic modulus change characteristics, and breaking stress change characteristics in addition to the clothing product (sock) described in the embodiment. It can be used for various purposes. For example, the liquid crystalline fiber material and fiber product of the present invention can be used in industrial fields such as actuators and filters. It may also be used in the medical and medical fields such as artificial muscles and catheters.

10 Socks 11 Fiber (Liquid crystalline fiber material)

Claims (10)

1. A liquid crystalline fiber material comprising a liquid crystalline polyurethane that reversibly expands and contracts between a liquid crystal phase and an isotropic phase according to a temperature change,
   Based on the state in which the liquid crystalline polyurethane is most contracted (100%), the elongation in the fiber direction is set to 102 to 200%, or the state in which the liquid crystalline polyurethane is most expanded (100%). ), A liquid crystalline fiber material whose shrinkage in the fiber direction is set to 98.04 to 50%.
2. The liquid crystalline fiber material according to claim 1, wherein the liquid crystalline polyurethane is configured as a monofilament or a multifilament.
3. In the fiber direction, the elastic modulus of when the liquid crystalline polyurethane comprising the liquid crystal phase and E _1, when the elastic modulus of the time including the isotropic phase was E _2, satisfying the E 1 _/ E ₂ ≦ 1000 The liquid crystalline fiber material according to claim 1 or 2.
4. In the fiber direction, when rupture stress when the liquid crystalline polyurethane includes the liquid crystal phase is σ ₁ and rupture stress when the isotropic phase is included is σ ₂ , σ ₁ / σ ₂ ≦ 40 is satisfied. The liquid crystalline fiber material according to any one of claims 1 to 3.
5. The phase transition temperature (Ti) serving as a boundary between the liquid crystal phase and the isotropic phase is not less than the glass transition temperature (Tg) of the liquid crystalline polyurethane and not more than 100 ° C. The liquid crystalline fiber material described.
6. The liquid crystalline fiber material according to claim 5, wherein a difference between the phase transition temperature (Ti) and the glass transition temperature (Tg) is 20 ° C or more.
7. The liquid crystalline polyurethane includes a reaction product of a mesogen group-containing compound having an active hydrogen group, an isocyanate compound, an alkylene oxide and / or a styrene oxide, and a crosslinking agent. Liquid crystalline fiber material.
8. The liquid crystalline fiber material according to claim 7, wherein the crosslinking agent is a polyol having at least three reactive functional groups.
9. When the total amount of the mesogenic group-containing compound, the isocyanate compound, the alkylene oxide and / or the styrene oxide, and the crosslinking agent is 100 parts by weight, the amount of the crosslinking agent is 0.1 to 20 parts by weight. The liquid crystalline fiber material according to claim 7 or 8.
10. A fiber product using the liquid crystalline fiber material according to any one of claims 1 to 9,
    The textile product comprised so that the said elongation rate or the said shrinkage | contraction rate may differ locally.

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