Polyolefin filaments

Abstract

This invention provides a polyolefin filament containing a 4-methyl-1-pentene-α-olefin copolymer, which exhibits excellent flexibility and mechanical strength, as well as fabrics, headwear, and toys made using this filament. [Solution] A constituent unit derived from 4-methyl-1-pentene and C other than 4-methyl-1-pentene. 2-20 A polyolefin filament comprising a 4-methyl-1-pentene·α-olefin copolymer containing α-olefin-derived structural units, and a cellulose ester.

Description

[Technical Field]

[0001] This invention relates to polyolefin filaments. [Background technology]

[0002] Conventionally, flexible fibers have been used in various fields such as sports, apparel, and sanitary materials. One example of a flexible fiber is a fiber composed of filaments using a 4-methyl-1-pentene-α-olefin copolymer (see, for example, Patent Document 1). However, this fiber lacks sufficient mechanical strength, and there was room for improvement. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2017-197856 [Overview of the project] [Problems that the invention aims to solve]

[0004] This invention was made in view of the aforementioned problems, and aims to provide a polyolefin filament containing a 4-methyl-1-pentene·α-olefin copolymer that is flexible and has improved mechanical strength, as well as fabrics, headwear, and toys using this filament. [Means for solving the problem]

[0005] To solve the above problems, the present invention provides the following embodiments. [1] The constituent units are derived from 4-methyl-1-pentene and C other than 4-methyl-1-pentene. 2-20 A 4-methyl-1-pentene·α-olefin copolymer comprising a constituent unit derived from an α-olefin, Cellulose ester and, A polyolefin filament comprising the above. [2] The polyolefin filament according to [1], wherein the mass ratio of the 4-methyl-1-pentene·α-olefin copolymer to the cellulose ester is 99.9:0.1 to 50:50. [3] The polyolefin filament according to [1] or [2], wherein the cellulose ester is at least one selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. [4] A fabric made using the polyolefin filaments according to [1] to [3]. [5] A headdress comprising the polyolefin filaments according to [1] to [3]. [6] A toy comprising the polyolefin filaments according to [1] to [3]. [Advantages of the Invention]

[0006] The present invention can provide a polyolefin filament containing a 4-methyl-1-pentene·α-olefin copolymer, which is excellent in flexibility and mechanical strength, and a fabric, a headdress, and a toy using this filament. [Brief Description of the Drawings]

[0007] [Figure 1] A graph explaining the hysteresis characteristics in the color density - temperature curve of a heat-decoloring type reversible thermochromic composition. [Figure 2] A graph explaining the hysteresis characteristics in the color density - temperature curve of a heat-decoloring type reversible thermochromic composition having color memory. [Figure 3] A graph explaining the hysteresis characteristics in the color density - temperature curve of a heat-coloring type reversible thermochromic composition. [Embodiments for Carrying Out the Invention]

[0008] [Polyolefin Filament] The polyolefin filament according to the present invention (hereinafter sometimes referred to as "filament") comprises a 4-methyl-1-pentene / α-olefin copolymer and a cellulose ester. Each component constituting the polyolefin filament according to the present invention will be described below.

[0009] <<4-methyl-1-pentene / α-olefin copolymer>> The filament according to the present invention comprises a 4-methyl-1-pentene / α-olefin copolymer (hereinafter sometimes referred to as "polymer (I)"). The 4-methyl-1-pentene / α-olefin copolymer comprises at least a structural unit (Ia) derived from 4-methyl-1-pentene and a structural unit (Ib) derived from an α-olefin other than 4-methyl-1-pentene having C 2-20 Here, the "α-olefin having C 2-20 refers to an α-olefin having 2 to 20 carbon atoms and, unless otherwise specified, means not containing 4-methyl-1-pentene.

[0010] ​​​​​​​​​​​​​​The number of carbon atoms in the linear α-olefin is preferably 2 to 15, more preferably 2 to 10, and even more preferably 2 or 3. Examples of linear α-olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Among these, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, and 1-octene are preferred, with ethylene or propylene being more preferred.

[0013] The branched α-olefin has preferably 5 to 20 carbon atoms, and more preferably 5 to 15 carbon atoms. Examples of branched α-olefins include 3-methyl-1-butene, 3-methyl-1-pentene, and 3-ethyl-1-pentene.

[0014] The cyclic olefin has 3 to 20 carbon atoms, preferably 5 to 15. Examples of cyclic olefins include cyclopentene, cyclohexene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, and vinylcyclohexane.

[0015] Examples of aromatic vinyl compounds include mono- or polyalkylstyrenes such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, and p-ethylstyrene.

[0016] The number of carbon atoms in the conjugated diene is 4 to 20, preferably 4 to 10. Examples of conjugated dienes include 1,3-butadiene, isoprene, chloroprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 4-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-octadiene.

[0017] Examples of the functionalized vinyl compound include, for example, C 2-20 hydroxyl group-containing olefins such as linear or branched terminal hydroxylated α-olefins; C 2-20 halogenated olefins such as linear or branched halogenated α-olefins having a Group 17 atom of the periodic table; unsaturated carboxylic acids such as (meth)acrylic acid, propionic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid; unsaturated amines such as allylamine, 5-hexenylamine, 6-heptenylamine; succinic anhydrides such as (2,7-octadienyl)succinic anhydride, pentapropenyl succinic anhydride; unsaturated carboxylic acid anhydrides such as anhydrides obtained from the above unsaturated carboxylic acids; unsaturated carboxylic acid halides such as halides obtained from the above unsaturated carboxylic acids; unsaturated epoxy compounds; ethylenically unsaturated silane compounds and the like.

[0018] The α-olefin is used alone or in combination of two or more.

[0019] As the α-olefin, linear α-olefins of C 2-4 are preferred, and examples thereof include ethylene, propylene, 1-butene and the like. Since it is easy to improve the flexibility of the filament, ethylene or propylene is more preferred, and propylene is even more preferred.

[0020] In the 4-methyl-1-pentene·α-olefin copolymer, the blending ratios of 4-methyl-1-pentene, α-olefin and the like are measured by, for example, 13 13C NMR.

[0021] The 4-methyl-1-pentene·α-olefin copolymer preferably satisfies the requirements (i) to (v) described later.

[0022] The 4-methyl-1-pentene·α-olefin copolymer (i) The intrinsic viscosity [η] in decalin at 135°C is preferably 0.5 to 5.0 dL / g, more preferably 0.6 to 4.0 dL / g, and even more preferably 1.0 to 2.5 dL / g. The intrinsic viscosity [η] can be adjusted by the amount of hydrogen added during the polymerization process when preparing the copolymer. The intrinsic viscosity [η] is a value measured by the following method.

[0023] (Method for measuring intrinsic viscosity) (1) Dissolve approximately 20 mg of 4-methyl-1-pentene·α-olefin copolymer in 15 ml of decalin to prepare a decalin solution, and dissolve it in an oil bath at 135°C to obtain a specific viscosity (η sp ) Measure. (2) Dilute the decalin solution by adding another 5 ml of decalin, and obtain the specific viscosity (η sp ) is measured similarly. (3) The increase in viscosity per unit concentration (C) of the 4-methyl-1-pentene·α-olefin copolymer, i.e., the reduced viscosity (η red =η sp Find / C). (4) Plot the relationship between concentration and reduced viscosity, and determine the intrinsic viscosity [η] from the intercept when the concentration (C) is extrapolated to 0. Alternatively, determine the intrinsic viscosity [η] using the following formula (I).

number

[0024] 4-methyl-1-pentene·α-olefin copolymer is (ii) The melting point measured by differential scanning calorimetry (DSC) is preferably 200°C or less, or substantially no melting point, more preferably 110 to 180°C, or substantially no melting point, and even more preferably less than 160°C, or substantially no melting point. The melting point is C in copolymers. 2-20 The melting point can be adjusted by changing the proportion of α-olefins used. The melting point is the value measured by differential scanning calorimetry as described below.

[0025] (Differential scanning calorimetry) (1) Place approximately 5 mg of 4-methyl-1-pentene·α-olefin copolymer in an aluminum container, close the lid and seal it, and use it as the sample for measurement. (2) Place the sample to be measured in the differential scanning calorimetry device, raise the temperature to 290°C at a heating rate of 10°C / min, hold at 290°C for 5 minutes, and then lower the temperature to 20°C at a cooling rate of 10°C / min. (3) The melting point is determined from the temperature of the peak of the endothermic peak due to melting in the obtained DSC curve.

[0026] In the DSC curve, the area of ​​the endothermic peak is the enthalpy of fusion (ΔH). f This represents the area of ​​the endothermic peak, i.e., the enthalpy of fusion (ΔH), since no endothermic peak is observed when there is no melting point. f ) cannot be required. In this invention, "substantially no melting point" means that the enthalpy of melting in the DSC curve is substantially absent. "Substantially no melting point" means that the enthalpy of melting (ΔH f This includes a value of 0 to 10 J / g, and is preferably 0 to 5 J / g.

[0027] 4-methyl-1-pentene·α-olefin copolymer is (iii) Density is preferably 820-850 kg / m³ 3 , more preferably 825-850 kg / m 3 More preferably 825-845 kg / m 3 Particularly preferred is 825-840 kg / m³ 3 That is the case. Density is C in copolymer 2-20 The type of α-olefin, or 4-methyl-1-pentene and C 2-20 The composition can be adjusted by the proportion of α-olefins used. The density is a value measured according to the method compliant with JIS K7112.

[0028] 4-methyl-1-pentene·α-olefin copolymer is (iv) The molecular weight distribution (Mw / Mn) measured by gel permeation chromatography (GPC) is preferably 1.0 to 3.5, more preferably 1.3 to 3.0, and even more preferably 1.5 to 2.5. The molecular weight distribution (Mw / Mn) can be adjusted by the type of polymerization catalyst used in preparing the copolymer. The molecular weight distribution (Mw / Mn) is determined by measuring the mass-average molecular weight (Mw) and number-average molecular weight (Mn) using gel permeation chromatography as described below.

[0029] (Gel permeation chromatography) (1) Use o-dichlorobenzene as the mobile phase and 0.025% by mass of dibutylhydroxytoluene as an antioxidant, and move the mobile phase at a rate of 1.0 mL / min. (2) The concentration of the 4-methyl-1-pentene·α-olefin copolymer is adjusted to 15 mg / 10 mL, 500 μL is injected, and detection is performed using a differential refractometer. As the standard polystyrene, one with a mass-average molecular weight of 10 to 4 million is used. (3) The obtained chromatographs are analyzed using a calibration curve based on standard polystyrene samples to determine the mass-average molecular weight (Mw) and number-average molecular weight (Mn).

[0030] 4-methyl-1-pentene·α-olefin copolymer is (v) The melt flow rate (MFR) in accordance with JIS K7210 is preferably 0.1 to 100 g / 10 min, more preferably 0.5 to 50 g / 10 min, and even more preferably 0.5 to 30 g / 10 min. From the viewpoint of fluidity during filament molding, it is preferable that the melt flow rate be within the above range. The melt flow rate is measured in accordance with JIS K7210 at 230°C and under a 2.16 kg load.

[0031] The method for producing the 4-methyl-1-pentene·α-olefin copolymer is not particularly limited and can be produced by various methods. For example, in the presence of a polymerization catalyst, 4-methyl-1-pentene and C2-20 It can be produced by polymerizing with α-olefin.

[0032] <<Cellulose ester>> The filament according to the present invention comprises a cellulose ester (hereinafter sometimes referred to as "polymer (II)"). Cellulose esters are defined as cellulose in which at least one of the three hydroxyl groups in the glucose unit of cellulose is substituted with an acyl group represented by -COR (where R is a hydrocarbon group). Cellulose esters may have one hydroxyl group substituted with one type of acyl group, or two or more types of acyl groups.

[0033] Cellulose esters improve the mechanical strength of filaments without impairing their flexibility or spinnability. This is presumed to be due to physical entanglement between the side chain portion (-CH2-CH(CH3)2) of the 4-methyl-1-pentene-derived structural unit (polymethylpentene) in the 4-methyl-1-pentene-α-olefin copolymer and the side chain portion (acyl group) of the cellulose ester.

[0034] The cellulose esters are not particularly limited. Examples include cellulose acetate (cellulose monoacetate, cellulose diacetate, cellulose triacetate), cellulose acetate propionate, cellulose acetate butyrate, cellulose succinate, cellulose phthalate, cellulose acetate propionate butyrate, cellulose acetate hexanoate, cellulose acetate octanoate, and cellulose acetate decanoate. From the viewpoint of filament spinnability, the cellulose ester is preferably one or more selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. Cellulose acetate butyrate is more preferred because it readily entangles with the side chain portion of the constituent unit derived from 4-methyl-1-pentene, resulting in better mechanical strength of the filament.

[0035] The cellulose ester has a number-average molecular weight of preferably 10,000 to 80,000, more preferably 20,000 to 70,000, even more preferably 25,000 to 50,000, and particularly preferably 35,000 to 45,000. It is preferable that the number-average molecular weight be within the above range because it can easily improve the mechanical strength of the filament. The number-average molecular weight is the polystyrene-equivalent molecular weight measured by size exclusion chromatography.

[0036] The cellulose ester has a melting point preferably between 120 and 250°C, more preferably between 125 and 210°C, even more preferably between 130 and 200°C, and particularly preferably between 150 and 180°C. From the viewpoint of filament moldability, it is preferable that the melting point be within the above range. The melting point is a value measured by differential scanning calorimetry (DSC).

[0037] Cellulose esters have a glass transition temperature preferably of 80 to 200°C, more preferably 90 to 180°C, even more preferably 100 to 160°C, and particularly preferably 120 to 140°C. It is preferable for the glass transition temperature to be within the above range because it can easily improve the mechanical strength of the filament. The glass transition temperature is a value measured by differential scanning calorimetry (DSC) in accordance with the method for measuring the transition temperature of plastics specified in JIS K7121.

[0038] Cellulose esters can be used individually or in combination of two or more types.

[0039] In the filament according to the present invention, the mass ratio of the 4-methyl-1-pentene·α-olefin copolymer to the cellulose ester is preferably 99.9:0.1 to 50:50, more preferably 99.5:0.5 to 75:25, even more preferably 99:1 to 80:20, and particularly preferably 97:3 to 85:15. By having the mass ratio within the above range, it becomes easy to improve the mechanical strength while maintaining good spinnability of the filament.

[0040] Filaments are manufactured by melt spinning using a melt spinning apparatus or the like, in which polymer (I) and polymer (II) are melt-blended and integrated into a single form. The filament may have a structure in which polymer (I) and polymer (II) are mutually compatible to form a single phase, or it may have a structure in which polymer (I) and polymer (II) are phase-separated to form multiple phases (i.e., a sea-island structure). Here, "mutually compatible" includes not only a state in which the polymers are completely compatible with each other, but also a state in which they are partially compatible (a state in which there is a mixture of areas where one polymer and the other polymer are phase-separated with areas where the polymers are completely compatible with each other).

[0041] Furthermore, a mixture obtained by melt-blending polymer (I) and polymer (II), along with polymer (III), may be used to form composite filaments (composite fibers) in the form of core-sheath type, side-by-side type, sea-island type, or split type. In the case of the core-sheath type, it is preferable that the entire outer circumference of the core is covered by the sheath.

[0042] Polymer (III) may be a general-purpose thermoplastic resin, and examples include polyolefins such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, polypropylene-ethylene copolymer, polyisobutylene, polybutadiene, and ethylene-propylene rubber; polyamides such as nylon 6, nylon 6,6, nylon 6,9, nylon 6,10, nylon 11, nylon 12, nylon 6-12 copolymer, nylon 6,9-12 copolymer, and polyamide elastomers; polyesters such as polyhexamethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, saturated aliphatic polyester, and polyester elastomers; polyvinyl chloride; and polyvinylidene chloride.

[0043] The filament may be in a monofilament form using a single filament, or it may be in a multifilament form consisting of multiple monofilaments.

[0044] The average outer diameter of the filament according to the present invention is not particularly limited, but is preferably 0.2 to 3 mm. The average outer diameter corresponds to the average of the outer diameters at multiple points on a single filament. The outer diameter can be calculated, for example, using image analysis software or a planimeter, based on cross-sectional images of the filament taken with an optical microscope or electron microscope. If the cross-sectional shape of the filament is not circular, the outer diameter is defined as the diameter of the circle formed by treating the cross-sectional area as the area of ​​a circle. Filaments having a desired outer diameter or average outer diameter can be manufactured by appropriately adjusting conditions such as temperature and speed during the process of extruding and stretching the resin composition that forms the filament from the spinneret when manufacturing the filament using a melt spinning apparatus. When the average outer diameter is less than 0.2 mm, the effect of improving mechanical strength with cellulose ester is difficult to achieve. On the other hand, when the average outer diameter exceeds 3 mm, it becomes too thick, and the flexibility of the filament is easily compromised.

[0045] The cross-sectional shape of the filament can be a circle, an ellipse, or other circular shape; a polygon, such as a trefoil, triangle, square, pentagon, or star shape; or a Y-shape, but from the viewpoint of spinnability and processability, a circular cross-sectional shape is preferable. When the filament has a core-sheath type form, when the cross-section of the filament is observed, it may be a concentric core-sheath type in which the core and sheath are arranged in concentric circles, or it may be an heterocentric core-sheath type in which the centers of the core and sheath are different.

[0046] The filament according to the present invention has shape memory properties. Shape memory properties refer to the ability to be easily deformed into any shape within a specific temperature range and to fix the deformed state within that temperature range (shape retention), and the ability to restore the original shape from the deformed shape as needed (shape restoration). In the present invention, shape retention and shape restoration are collectively referred to as "shape memory properties." The shape memory property is presumed to be exhibited by the side chain portion (-CH2-CH(CH3)2) of the 4-methyl-1-pentene-derived structural unit (polymethylpentene) in the 4-methyl-1-pentene-α-olefin copolymer. Because the side chain portion of the 4-methyl-1-pentene-derived structural unit has a branched structure, the side chain portions easily intertwine in a complex manner, and it is thought that good shape memory is exhibited by the formation of a strong network structure starting from pseudo-crosslinking points.

[0047] Shape memory properties are related to the glass transition temperature of the resin composition that makes up the filament. Below the glass transition temperature of the resin composition, the thermal motion of the molecular chains (micro-Brownian motion) is restricted, resulting in a high modulus of elasticity due to energy elasticity and a rigid property. As the temperature rises and reaches a temperature range above the glass transition temperature of the resin composition, the modulus of elasticity decreases due to entropy elasticity based on micro-Brownian motion, causing the material to exhibit viscous properties, making it possible to deform the filament by applying external stress. If the filament is cooled to a temperature range below the glass transition temperature while maintaining the deformed state created by applying external stress, the micro-Brownian motion of the molecular chains is restricted again, the modulus of elasticity increases, and the filament can be fixed in the deformed state. This state is maintained even after the external stress is removed. When the temperature reaches a range above the glass transition temperature again, the modulus of elasticity decreases due to micro-Brownian motion, and the crosslinking points attempt to return to their initial positions and a stable state, making it possible to restore the filament to its original shape. In other words, the glass transition temperature of the filament is considered to be the deformation temperature of the filament. The shape memory property of the filament according to the present invention is exhibited by the 4-methyl-1-pentene·α-olefin copolymer; therefore, the glass transition temperature of the resin composition is predominantly determined by the glass transition temperature of the 4-methyl-1-pentene·α-olefin copolymer. In systems where the 4-methyl-1-pentene·α-olefin copolymer and the cellulose ester are mutually compatible, the glass transition temperature of the cellulose ester may also have an influence. In other words, the glass transition temperature of the resin composition (filament) can be adjusted by changing the blending ratio of each polymer.

[0048] Because cellulose esters do not easily change their properties even in temperature ranges above the glass transition temperature of the resin composition, they maintain good mechanical strength even if the filament transitions to a viscous state in temperature ranges above the glass transition temperature. In other words, they can suppress filament breakage when external stress is applied to deform the filament. Therefore, by incorporating cellulose ester into the filament according to the present invention, a filament with excellent flexibility, mechanical strength, and shape memory properties can be obtained.

[0049] The glass transition temperature (hereinafter sometimes referred to as "Tg") of a resin composition comprising a 4-methyl-1-pentene·α-olefin copolymer and a cellulose ester is a value measured by differential scanning calorimetry (DSC) as described below, in accordance with the method for measuring the transition temperature of plastics specified in JIS K7121.

[0050] (Differential scanning calorimetry) (1) Place approximately 10 mg of the resin composition into an aluminum container, close the lid, and seal it to use as a sample for measurement. (2) Place the sample to be measured in the differential scanning calorimetry device, maintain it at -20°C until the device stabilizes, then raise the temperature to 70°C at a heating rate of 10°C / min (1st heating), and maintain it at 70°C for 5 minutes. (3) Cool the temperature down to -20°C at a cooling rate of 10°C / min, and hold at -20°C for 5 minutes. (4) Heat again to 70°C at a heating rate of 10°C / min (2nd heating). (5) The glass transition temperature is determined from the change in the baseline in the DSC curve obtained from the second heating.

[0051] The glass transition temperature of the resin composition comprising a 4-methyl-1-pentene·α-olefin copolymer and a cellulose ester is preferably 0 to 70°C, more preferably 10 to 60°C, even more preferably 20 to 50°C, and particularly preferably 20 to 40°C. Filaments whose glass transition temperature is within the above temperature range of the resin composition can be repeatedly deformed into any shape, fixed and held in the deformed shape, and restored to the original shape by applying commonly used, known heating or cooling methods or deformation methods.

[0052] Heating methods include, for example, heat from hands, a medium such as hot water, steam or laser light, a hot air device using an electrically conductive resistance heating element (nichrome wire, positive resistance heating element, etc.) as a heat source, a box-type heating device, a hair dryer, etc. Cooling methods include, for example, those using refrigerants such as chilled water or ice water, air coolers using Peltier elements as a cooling source, box-type cooling devices, freezers, refrigerators, and refrigerant packs. Each can be illustrated with an example. Examples of deformation methods include fingers, trowels, or shaping jigs of various shapes. In particular, when the glass transition temperature of a resin composition made of 4-methyl-1-pentene·α-olefin copolymer and cellulose ester is in the temperature range of 20 to 40°C, it becomes possible to easily deform it into any shape, fix and maintain the deformed shape, and restore it to its original shape by applying heat or cold (for example, heat from fingers, or cold from hot water, ice water, etc.) that is commonly used in the living environment temperature range or nearby.

[0053] The filament according to the present invention can be deformed into shapes such as circular, elliptical, square, rectangular, heart-shaped, star-shaped, spiral, and vortex by applying external stress and bending it in a temperature range above the glass transition temperature of the resin composition of 4-methyl-1-pentene-α-olefin copolymer and cellulose ester.

[0054] The filament according to the present invention can also have its length changed by applying external stress to cause tensile deformation in a temperature range above the glass transition temperature of the resin composition. Specifically, a filament of a certain length (initial length) can be stretched to any desired length by applying external stress in a temperature range above the glass transition temperature of the resin composition, and the filament can be fixed in the stretched state by cooling it to a temperature range below the glass transition temperature of the resin composition. This state is maintained even after the external stress is removed. When the temperature range reaches above the glass transition temperature of the resin composition again, the filament shrinks and can be restored to its initial length. On the other hand, if the filament is stretched beyond a certain magnification, it can be fixed in the stretched state by cooling it to a temperature range below the glass transition temperature of the resin composition. This state is maintained even after the removal of external stress. When the temperature range exceeds the glass transition temperature of the resin composition, the filament shrinks, but it may remain longer than its initial length and may not return to its initial length. In other words, if a filament is stretched to a length less than a certain ratio from its initial length, it will return to its initial length. However, if it is stretched to a length greater than a certain ratio, it may remain longer than its initial length even after contraction, and may not return to its initial length. In this case, it can be restored to its original state (initial length) by cutting it with scissors or similar tools. For example, in a toy using the filament according to the present invention as hair, if the hair is stretched to a length less than a certain ratio from its initial length, the length of the hair can be freely changed by repeatedly stretching and contracting it. Also, if the hair is stretched to a length greater than a certain ratio from its initial length, the length of the hair can be irreversibly increased, or the length of the extended hair can be changed to any desired length by cutting it with scissors or the like.

[0055] <<Coloring agent>> The filament according to the present invention can be colored with a coloring agent. Dyes, pigments, and resin particles can all be used as colorants. In other words, a colorant may contain one or more selected from the group consisting of dyes, pigments, and resin particles.

[0056] Examples of dyes include acid dyes, basic dyes, direct dyes, reactive dyes, vat dyes, sulfur dyes, alloy dyes, cationic dyes, and disperse dyes. Examples of pigments include inorganic pigments, organic pigments, fluorescent pigments, phosphorescent pigments, and luminescent pigments. Microcapsulated pigments, in which the above-mentioned dyes or pigments are encapsulated in microcapsules, are also acceptable. As the resin particles, colored resin particles containing the above-mentioned dyes or pigments can be used. Examples of colored resin particles include colored resin particles in which the dye is homogeneously dissolved or dispersed within the resin particles, colored resin particles in which the dye is dyed onto the resin particles, colored resin particles in which the pigment is dispersed within the resin particles, and colored resin particles in which the surface of the resin particles is coated with pigment. The resin particles also include solid resin particles and hollow resin particles.

[0057] Thermochromic or photochromic materials can also be used as colorants.

[0058] <Thermochromic materials> Thermochromic materials are materials that change color with temperature changes, and this thermochromic function, which changes color with temperature changes, can be imparted to filaments. The color change may be reversible or irreversible, but reversible thermochromic materials are preferred because they allow the filament to repeatedly change color with temperature changes. Examples of reversible thermochromic materials include a reversible thermochromic composition comprising at least (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of components (a) and (b). This may be a reversible thermochromic microcapsule pigment in which the reversible thermochromic composition is encapsulated in microcapsules, or a reversible thermochromic resin particle in which the reversible thermochromic composition is dispersed in a thermoplastic resin or thermosetting resin.

[0059] The reversible thermochromic composition may be a heat-decolorizing type reversible thermochromic composition having a relatively small hysteresis width (ΔH) (ΔH = 1 to 7°C), as described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-29398, etc. Heat-decolorizing type means that it decolorizes when heated and develops color when cooled. This reversible thermochromic composition changes color before and after a predetermined temperature (color change point), exhibiting a decolorized state in the temperature range above the high-temperature color change point and a colored state in the temperature range below the low-temperature color change point. Of the two states, only one specific state exists in the room temperature range, and the other state is maintained as long as the heat or cold required to bring about that state is applied, but returns to the state exhibited in the room temperature range when the application of heat or cold is stopped (see Figure 1).

[0060] The reversible thermochromic composition may be a heat-decolorizing type reversible thermochromic composition having a large hysteresis width (ΔH = 8 to 80°C) as described in Japanese Patent Publication No. 4-17154, Japanese Patent Application Publication No. 7-179777, Japanese Patent Application Publication No. 7-33997, Japanese Patent Application Publication No. 8-39936, Japanese Patent Application Publication No. 2005-1369, etc. Heat-decolorizing type means that it decolorizes when heated and develops color when cooled. This reversible thermochromic composition exhibits color memory properties in a specific temperature range (between the color development start temperature t2 and the color decolorization start temperature t3 (essentially a two-phase retention temperature range)). The shape of the curve plotting the change in color intensity due to temperature changes follows a significantly different path depending on whether the temperature is raised from a temperature below the color development temperature range or from a temperature above the color development temperature range t4. The colored state at temperatures below the complete color development temperature t1, or the decolorized state at high temperatures above the complete decolorization temperature t4, is determined to be color-memory (see Figure 2).

[0061] The reversible thermochromic composition may be a heat-activated, reversible thermochromic composition using gallic acid ester, as described in Japanese Patent Publication No. 51-44706, Japanese Patent Application Publication No. 2003-253149, etc. Heat-activated means that it develops color when heated and disappears when cooled (see Figure 3).

[0062] The reversible thermochromic composition is a compatible mixture comprising the above-mentioned components (a), (b), and (c) as essential components. The proportion of each component depends on the concentration, discoloration temperature, discoloration form, or type of each component. Generally, the component ratio that yields the desired properties is in the range of 0.1 to 50 parts by mass, preferably 0.5 to 20 parts by mass, of component (b) per 1 part by mass of component (a), and 1 to 800 parts by mass, preferably 5 to 200 parts by mass, more preferably 5 to 100 parts by mass, and even more preferably 10 to 100 parts by mass of component (c).

[0063] <Photochromic materials> Photochromic materials are materials that change color depending on the presence or absence of light irradiation. They can impart a photochromic function to filaments, such as developing color when irradiated with light and losing color when the light irradiation is stopped. The color change may be reversible or irreversible, but reversible photochromic materials are preferred because they allow the filament to repeatedly change color depending on the presence or absence of light irradiation. Examples of reversible photochromic materials include photochromic compounds. Photochromic compounds change color when irradiated with sunlight, ultraviolet light, or violet to blue light with a peak emission wavelength in the range of 400-495 nm, and lose their color when irradiation is stopped. Specifically, examples include spirooxazine compounds, spiropyran compounds, naphthopyran compounds, diarylethene compounds, etc. Furthermore, examples of reversible photochromic materials include reversible photochromic compositions containing a photochromic compound and an oligomer. The oligomer can assist in the molecular structural change of the photochromic compound and adjust the sensitivity of the color change. It also enhances the color intensity and lightfastness of the reversible photochromic composition. This may be a reversible photochromic microcapsule pigment in which the reversible photochromic composition is encapsulated in microcapsules, or reversible photochromic resin particles in which the reversible photochromic composition is dispersed in a thermoplastic resin or thermosetting resin.

[0064] Reversible thermochromic materials or reversible photochromic materials may contain non-chromogenic colorants such as general dyes and / or pigments. By containing non-chromogenic colorants, the reversible thermochromic materials or reversible photochromic materials undergo an intermutation color change from a first color to a second color.

[0065] The reversible thermochromic material is preferably a reversible thermochromic microcapsule pigment in which a reversible thermochromic composition is encapsulated in a wall film. Similarly, the reversible photochromic material is preferably a reversible photochromic microcapsule pigment in which a reversible photochromic composition is encapsulated in a wall film. By encapsulating a reversible thermochromic composition or a reversible photochromic composition in microcapsules, chemically or physically stable pigments can be constructed. Furthermore, under various usage conditions, the reversible thermochromic composition or reversible photochromic composition can maintain the same composition and produce the same effects.

[0066] The wall film forms an internal space that encloses the reversible thermochromic composition or reversible photochromic composition, and this internal space is separated from the outside. As a result, the microcapsule pigment is less susceptible to external influences, protecting the reversible thermochromic composition or reversible photochromic composition from various degradation factors, and allowing it to exhibit its reversible thermochromic function or reversible photochromic function over a long period of time. Reversible thermochromic function refers to the function of a heat-decolorizing type reversible thermochromic composition in which it exhibits color development in the temperature range below the low-temperature color change point (complete color development temperature t1) and exhibits color development in the temperature range above the high-temperature color change point (complete color development temperature t4). Alternatively, it refers to the function of a heat-developing type reversible thermochromic composition in which it exhibits a decolorizing state in the temperature range below the low-temperature color change point (complete color development temperature T1) and exhibits color development in the temperature range above the high-temperature color change point (complete color development temperature T4). Reversible light-changing function refers to a function that causes a material to become colored when exposed to light and to become colorless when the light exposure is stopped.

[0067] The material of the wall film is not particularly limited. Examples include polyurea, polyamide, polyurethane, epoxy resin, melamine resin, urea resin, urea urethane resin, isocyanate resin, vinyl resin, gelatin, ethylcellulose, polyvinyl alcohol, carboxymethylcellulose, etc. These can be used individually or in combination of two or more.

[0068] Microencapsulated pigments are obtained by known microencapsulation methods. Examples of microencapsulation methods include interfacial polymerization, in situ polymerization, liquid curing and coating, phase separation from aqueous solutions, phase separation from organic solvents, melt-dispersion-cooling, air suspension and coating, and spray drying, and are selected as appropriate depending on the application.

[0069] Depending on the purpose, a resin coating or the like may be applied to the surface of the microcapsules to provide durability or modify the surface properties.

[0070] Microcapsule pigments consist of a microcapsule wall (wall material) and an encapsulated substance (including a reversible thermochromic composition or a reversible photochromic composition), with the mass ratio of encapsulated substance to wall preferably being 7:1 to 1:1. Having the mass ratio of encapsulated substance to wall within this range prevents a decrease in color density and vividness during color development. More preferably, the mass ratio of encapsulated substance to wall is 6:1 to 1:1.

[0071] Colored filaments can be manufactured by incorporating a coloring agent into the resin composition that forms the filament. Alternatively, colored filaments can be manufactured by printing or coating a liquid composition, such as a printing ink or paint, prepared by dispersing a coloring agent in a vehicle containing a binder resin and various additives as needed, onto the filament surface using various printing or coating methods to create a colored layer.

[0072] The proportion of the colorant to the total mass of the resin composition forming the filament is not particularly limited. Preferably, it is 0.01 to 30% by mass, more preferably 0.1 to 20% by mass, and even more preferably 1 to 15% by mass. When the coloring agent is the above-mentioned reversible thermochromic material or reversible photochromic material, the proportion of the coloring agent to the total mass of the resin composition forming the filament is not particularly limited. Preferably, it is 0.1 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 3 to 15% by mass. By keeping the proportion of the colorant within the above range, the dispersion stability of the colorant in the resin composition is excellent, and a filament with the desired color density can be easily obtained.

[0073] The proportion of the colorant to the total mass of the liquid composition is not particularly limited, but is preferably 0.01 to 50% by mass, more preferably 0.1 to 30% by mass, and even more preferably 1 to 15% by mass. When the coloring agent is the above-mentioned reversible thermochromic material or reversible photochromic material, the proportion of the coloring agent to the total mass of the liquid composition is not particularly limited, but is preferably 0.5 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 5 to 15% by mass. By keeping the proportion of the coloring agent within the above range, the dispersion stability of the coloring agent in the vehicle is excellent, and filaments with the desired color density can be easily obtained.

[0074] When the colorant is a reversible thermochromic microcapsule pigment or a reversible photochromic microcapsule pigment, the average particle size of these microcapsule pigments is preferably 0.1 to 30 μm, more preferably 0.5 to 20 μm, and even more preferably 0.5 to 10 μm. If the average particle size exceeds 30 μm, the dispersion stability and processability tend to be poor when blended into a resin composition or liquid composition. On the other hand, if the average particle size is less than 0.1 μm, it becomes difficult to exhibit high-concentration color development.

[0075] The average particle diameter is the equivalent diameter of an isovolume sphere measured using a laser diffraction / scattering particle size distribution analyzer that has undergone a predetermined calibration [for example, Horiba, Ltd., product name: LA-960V2]. The average particle size is the average value of the equivalent diameter of an equal-volume sphere (the particle size D50, i.e., the median diameter, which corresponds to a frequency of 50% when the particle size distribution is determined based on volume).

[0076] The prescribed calibration will be explained. If the particle size of all microcapsules exceeds 0.20 μm, the average value of the equivalent diameter of equivolute spheres is measured using the Coulter method with a particle size distribution analyzer (e.g., Multisizer 4e, manufactured by Beckman Coulter, Inc.), and calibration is performed based on that value.

[0077] In cases other than those described above, the microcapsule region is determined using image analysis-based particle size distribution measurement software (for example, MacView, manufactured by Mountec Co., Ltd.), the projected area equivalent diameter (Heywood diameter) is calculated from the area of ​​the microcapsule region, and calibration is performed based on the average value of these equivalent diameters of equivolute spheres.

[0078] <> The filament according to the present invention may also contain various additives as needed. Examples of additives include flame retardants; dispersants such as waxes; light stabilizers such as ultraviolet absorbers, antioxidants, anti-aging agents, singlet oxygen quenchers, ozone quenchers, superoxide anion quenchers, visible light absorbers, infrared absorbers; fluorescent whitening agents; surfactants; antistatic agents; water repellents; fungicides; insecticides; plasticizers such as phthalates, aliphatic dibasic acid esters, phosphate esters, epoxy, phenols, and trimet acids; and lubricants. Furthermore, calcium carbonate, magnesium carbonate, titanium dioxide, talc, etc., may be added to improve processability and physical properties.

[0079] Since the filament according to the present invention can be deformed into any shape by heat or cold, fixed and held in the deformed shape, and restored to the original shape, it is preferable to use a thermochromic material that changes color with temperature as the coloring agent. As the color can be changed repeatedly, the above-mentioned reversible thermochromic material is preferred as the thermochromic material, and reversible thermochromic microcapsule pigments are more preferred.

[0080] The glass transition temperature of the resin composition comprising a 4-methyl-1-pentene-α-olefin copolymer and a cellulose ester is preferably approximately the same as the complete color development temperature t1 or complete decolorization temperature t4 of the reversible thermochromic material (reversible thermochromic composition). This allows the temperature at which the filament changes from a rigid state to a viscous state to be synchronized with the temperature at which the reversible thermochromic material changes color, making it possible to determine whether the filament has reached a temperature at which it can be deformed by the color change of the reversible thermochromic material.

[0081] Here, "approximately identical" means that, when the glass transition temperature is temperature Tg, temperature Tg and temperature t1, or temperature Tg and temperature t4, are exactly the same temperature. In this invention, it also means that the difference between temperature Tg and temperature t1 (Δt1 = Tg - t1) is between 0 and 2, or that the difference between temperature Tg and temperature t4 (Δt4 = t4 - Tg) is between 0 and 2. In other words, in this invention, "approximately identical" means that 0 ≤ Δt1 ≤ 2, or 0 ≤ Δt4 ≤ 2. With respect to Δt1 or Δt4, preferably 0≦Δt1≦1 or 0≦Δt4≦1, more preferably 0≦Δt1<1 or 0≦Δt4<1, and even more preferably Δt1=0(Tg=t1) or Δt4=0(Tg=t4).

[0082] An example is given below for the case where the glass transition temperature of the resin composition is the same as the complete color development temperature t1 of the reversible thermochromic material, i.e., Δt1=0 (Tg=t1). When the filament is heated to a temperature of t4 or higher, the reversible thermochromic material decolorizes and the filament changes color. At this time, the filament can be deformed into any shape by applying an external force. After deforming the filament into an arbitrary shape by applying an external force, if it is cooled to a temperature below Tg (temperature t1) while the external force is still applied, the reversible thermochromic material develops color and the filament changes color, and the filament can be fixed in the deformed shape even after the external force is removed. Therefore, it is possible to determine that the properties of the filament have changed and that the temperature has reached a point where the filament can be held in the deformed shape without applying an external force by observing the change from the decolorized state to the colored state of the reversible thermochromic material, i.e., the color change of the filament.

[0083] An example is given below for the case where the glass transition temperature of the resin composition is the same as the complete decolorization temperature t4 of the reversibly thermochromic material, i.e., Δt4=0 (Tg=t4). When a colored filament is heated above a temperature Tg (temperature t4), the reversible thermochromic material loses its color, causing the filament to change color, and the filament can be deformed into any shape by applying an external force. Therefore, the change in the properties of the filament, which allows it to be deformed into any shape by applying an external force, can be determined by the change from the colored state to the decolorized state of the reversible thermochromic material, i.e., the change in the color of the filament.

[0084] The glass transition temperature of the resin composition is between the complete color development temperature t1 and the complete decolorization temperature t4 of the reversible thermochromic material, preferably satisfying at least one of Δt1≧5 or Δt4≧5, and more preferably satisfying both Δt1≧5 and Δt4≧5. This allows the filament to reach a temperature sufficiently higher than the temperature at which its properties change, and to be easily deformed into any shape by applying an external force, which can be determined by the color change of the filament. Furthermore, after the filament has been deformed into an arbitrary shape by applying an external force, it can be determined by the color change of the filament to reach a temperature sufficiently lower than the temperature at which its properties change, and to be well maintained in the deformed shape without applying an external force. With respect to Δt1 or Δt4, preferably Δt1≧10 or Δt4≧10.

[0085] An example is given below for the case where the glass transition temperature of the resin composition is between the complete color development temperature t1 and the complete decolorization temperature t4 of the reversible thermochromic material, and satisfies Δt1≧5 and Δt4≧5. The filament is in a colored state at temperature Tg, and when heated above temperature t4, the reversible thermochromic material decolorizes, causing the filament to change color, and the filament can be easily deformed into any shape by applying an external force. Therefore, it is possible to determine that the filament can be easily deformed into any shape by applying an external force at a temperature sufficiently higher than the temperature at which the properties of the filament change, by observing the change from the colored state to the decolorized state of the reversible thermochromic material, i.e., the color change of the filament. After deforming the filament into an arbitrary shape by applying an external force, if the material is cooled to a temperature below t1 while the external force is still applied, the reversible thermochromic material will change color, and the deformed shape of the filament will be well maintained even after the external force is removed. Therefore, it is possible to determine that the deformed shape of the filament will be well maintained without applying an external force, by observing the change from a decolorized state to a colored state of the reversible thermochromic material, i.e., the color change of the filament. Here, if a filament heated to a temperature of t4 or higher and deformed into an arbitrary shape is cooled to a temperature range above t1 but below Tg while an external force is applied, the reversible thermochromic material remains in a decolorized state, and the filament can be held in the deformed shape without applying any external force. Furthermore, as long as it is not cooled below t1, the reversible thermochromic material remains in a decolorized state, and the deformation of the filament into an arbitrary shape and its deformation can be repeatedly performed. Also, when cooled below t1, the reversible thermochromic material becomes colored. When heated to a temperature range above Tg but below t4, the reversible thermochromic material remains in a colored state, and the filament can be deformed into an arbitrary shape by applying an external force. Furthermore, as long as it is not heated above t4, the reversible thermochromic material remains in a colored state, and the deformation of the filament into an arbitrary shape and its deformation can be repeatedly performed. In other words, it is possible to repeatedly deform the filament into any shape and maintain the deformed shape while selectively maintaining either a colored or decolorized state of the reversible thermochromic material.

[0086] The filament according to the present invention can be used in fabrics, and it is possible to obtain fabrics that are flexible and have excellent mechanical strength. The fabric is not particularly limited, but examples include woven fabrics, knitted fabrics, braided fabrics, nonwoven fabrics, pile fabrics, etc. The fabric can be made by using the filament according to the present invention in at least one of the warp or weft threads.

[0087] A head ornament equipped with the filament according to the present invention can be obtained, and this head ornament has good flexibility and mechanical strength. Headwear is not limited to any specific type, but examples include hair wigs, hair extensions, and hairpieces.

[0088] A toy equipped with the filament according to the present invention can be obtained, and this toy has good flexibility and mechanical strength, and is highly marketable. While not specifically limited to toys, examples include doll toys or animal-shaped toys with hair or fur made of filaments, stuffed animals with filament hair, or accessories thereof. Examples of accessories include hair extensions for doll toys, clothing, hats, bags, and shoes for doll toys. Hair or fur made of filaments can be used by implanting it onto the head, face, torso, limbs, etc., of doll toys or animal-shaped toys.

[0089] When the average outer diameter of the filament is 0.2 to 0.5 mm, the filament can be used as toy hair for toys such as dolls by methods such as using a hair flocking machine, or by fixing the ends of the filaments with a fixing piece that can bundle multiple filaments together, and then fixing the fixing piece to the part of the toy to be flocked. When the average outer diameter of the filament is 0.5 to 1.5 mm, the filament can be used as toy hair for dolls and other toys by methods such as fixing a portion of the filament using a fixing piece that can bundle multiple filaments together and then fixing the fixing piece to the part of the toy to be filamented, or by interposing the filament between metal wires, twisting the metal wires together to fix the filament to the metal wire, and then fixing this metal wire to the part of the toy to be filamented. When the average outer diameter of the filament is 1 to 3 mm (preferably 1.5 to 3 mm), in addition to the method of fixing the filament to the part of the toy to be implanted as toy hair using the fixing piece or metal wire described above, the filament can also be applied to toys such as dolls as toy hair by molding it integrally with the toy (for example, the head or scalp of a doll).

[0090] Furthermore, the following are examples of products using the filament according to the present invention. (1) Clothing Clothing such as T-shirts, sweatshirts, blouses, dresses, swimwear, raincoats, and ski wear; underwear; footwear such as shoes; shoelaces; shoe components such as insoles, outsoles, and midsoles; cloth personal items such as towels, handkerchiefs, and furoshiki (wrapping cloths); gloves; ties; hats; scarves; sportswear, etc. (2) Mobility products Steering wheel, saddle, shift lever, bumper, seat, seat belt, headrest, armrest, door trim, instrument panel, various supporters, various cushions, vibration damping materials, etc. (3) Indoor decorations Carpets, curtains, curtain cords, tablecloths, rugs, cushions, seat cushions, picture frames, artificial flowers, photo frames, etc. (4) Furniture Bedding such as futons, pillows, mattresses, and beds; chairs, floor chairs, sofas; lighting fixtures; heating and cooling appliances, etc. (5)Electronic equipment Mobile phones, smartphones, smartwatches, smart glasses, earphones, headphones, computers, mice, cameras (e.g., grip parts), speakers, games, protective cases for various electronic devices, covers for various electronic devices, etc. (6) Ornaments Rings, bracelets, tiaras, necklaces, earrings, hair clips, false nails, ribbons, scarves, watches (e.g., bands), glasses (e.g., nose pads and earmuffs), keychains, etc. (7) Stationery Writing instruments (e.g., grips); covers for notebooks, diaries, books, etc.; adhesive tape, etc. (8)Daily necessities Toiletries such as disposable diapers, bath products, toothbrushes, insulated bags, hand warmers, thermometers, watering cans, buckets, cleaning supplies, masks (e.g., nose fitters), face masks, foundation tape, cosmetics, etc. (9) Kitchenware Cooking utensils (for example, knife handles), lunch boxes, water bottles, cups, plates, chopsticks, spoons, forks, frying pans, coasters, pots, trivets, placemats, etc. (10) Medical and nursing care supplies Supporters, casts, bandages, adhesive bandages, lumbar support chairs, wheelchairs, health equipment, etc. (12) Others Calendars, labels, cards, recording materials, various anti-counterfeiting printed materials; books such as picture books; sports equipment such as grip tape for tennis rackets and baseball bats, gloves, protectors, and nets; bags; packaging containers; embroidery thread; fishing gear; musical instruments; cold packs; pouches such as wallets; umbrellas; vehicles; buildings; temperature sensing indicators; educational materials such as picture books and maps; pet supplies, etc. [Examples]

[0091] Examples are shown below, but the present invention is not limited thereto. Unless otherwise specified, "parts" in the examples refers to "parts by mass".

[0092] [Measurement of average outer diameter] The average outer diameter of the filaments prepared in the examples and comparative examples was determined by cutting a 100 mm filament into five equal parts, observing the cross-section of each of the five filaments using an optical electron microscope, and recording the maximum outer diameter. The average of these maximum outer diameters was then calculated and used as the average outer diameter. Additionally, a straight line was drawn connecting any two points on the outer circumference of the filament cross-section image obtained by optical microscope observation. The point where the length of this line was maximized was identified, and the length of this line was measured and used as the maximum outer diameter of the filament.

[0093] Example 1 [Making filaments] A resin composition constituting the filament was prepared by melt-blending 99 parts of 4-methyl-1-pentene·α-olefin copolymer [manufactured by Mitsui Chemicals, Inc., product name: Absorter EP-1001] and 1 part of cellulose ester (cellulose acetate butyrate) [manufactured by Eastman Chemical Company, product name: CAB-381-2] at 200°C. This resin composition was supplied to a general-purpose melt spinning apparatus, spun at 200°C, and then stretched to obtain a monofilament with an average outer diameter of 2.5 mm.

[0094] Each filament in Examples 2-6 was obtained in the same manner as in Example 1, except that the materials and proportions were changed as shown in Table 1. The average outer diameter of each filament in Examples 2-6 is as shown in Table 1.

[0095] Example 7 [Making filaments] A resin composition for the filament was prepared by melt-blending 90 parts of 4-methyl-1-pentene-α-olefin copolymer [Mitsui Chemicals, Inc., product name: Absorter EP-1001], 5 parts of cellulose ester (cellulose acetate butyrate) [Eastman Chemical Company, product name: CAB-381-2], 0.2 parts of a general pink pigment, and 4.8 parts of a reversible thermochromic microcapsule pigment at 200°C. This resin composition was supplied to a general-purpose melt spinning apparatus, spun at 200°C, and then stretched to obtain a monofilament with an average outer diameter of 2.5 mm. When this filament was heated to above 38°C, the microcapsule pigment completely lost its color, resulting in a pink color due to the general pigment. When cooled to below 14°C, the microcapsule pigment fully developed its color, resulting in a purple color that was a mixture of the blue from the microcapsule pigment and the pink from the general pigment. The filament's color change was reversible with temperature changes.

[0096] Comparative Example 1 [Making filaments] 100 parts of 4-methyl-1-pentene·α-olefin copolymer [manufactured by Mitsui Chemicals, Inc., product name: Absorter EP-1001] were supplied to a general-purpose melt spinning apparatus, spun at 200°C, and then stretched to obtain monofilaments with an average outer diameter of 2.4 mm.

[0097] [Table 1]

[0098] The materials listed in Table 1 are explained according to their respective note numbers. The various physical properties were calculated as described above. (1) Manufactured by Mitsui Chemicals, Inc., Product name: Absorter EP-1001 • Concentration of structural units derived from 4-methyl-1-pentene: 72 mol%, Concentration of structural units derived from propylene: 28 mol% ·Intrinsic viscosity [η]: 1.4dL / g • Melting point: None ·Density: 840kg / cm 3 ·Molecular weight distribution (Mw / Mn): 2.1 Melt Flow Rate (MFR): 10g / 10min (2) Cellulose acetate butyrate (manufactured by Eastman Chemical Company, product name: CAB-381-2) • Melting point: 177℃ • Glass transition temperature: 133℃ ·Number average molecular weight: 40,000 (3) Cellulose acetate butyrate (manufactured by Eastman Chemical Company, product name: CAB-531-1) • Melting point: 143℃ • Glass transition temperature: 115℃ ·Number average molecular weight: 40,000 (4) Cellulose acetate butyrate (manufactured by Eastman Chemical Company, product name: CAB-381-0.5) Melting point: 160℃ • Glass transition temperature: 130℃ ·Number average molecular weight: 30,000 (5) Cellulose acetate butyrate (manufactured by Eastman Chemical Company, product name: CAB-551-0.2) • Melting point: 135℃ • Glass transition temperature: 101℃ ·Number average molecular weight: 30,000 (6) Pink general pigment (7) Reversible thermochromic microcapsule pigments

[0099] The above-mentioned reversible thermochromic microcapsule pigment was prepared as follows. A reversible thermochromic composition consisting of (a) 1 part of 3,3-bis(4-diethylamino-2-ethoxyphenyl)-4-azaphthalide as component (b), 5 parts of 2,2-bis(4-hydroxyphenyl)hexafluoropropane as component (c) 50 parts of cyclohexylmethyl stearate as component was added to a mixed solution consisting of 35 parts of aromatic isocyanate prepolymer as a wall material and 40 parts of a co-solvent. The mixture was then emulsified and dispersed in an 8% aqueous polyvinyl alcohol solution, and after stirring continued while heating, 2.5 parts of a water-soluble aliphatic modified amine were added, and stirring was continued to prepare a microcapsule dispersion. A reversible thermochromic microcapsule pigment with an average particle size of 8 μm was obtained from the above microcapsule dispersion by centrifugation. The reversible thermochromic microcapsule pigment had a complete color development temperature t1 of 14°C and a complete decolorization temperature t4 of 38°C, and reversibly changed from blue to colorless with temperature changes.

[0100] [Glass transition temperature measurement] In accordance with the method for measuring the transition temperature of plastics specified in JIS K7121, the filaments of Examples 1 to 7 and Comparative Example 1 were each cut to a length of 0.5 mm or less to prepare test specimens. Approximately 10 mg of these test specimens were placed in an aluminum container, sealed with a lid, and samples for measuring the glass transition temperature were prepared. Each sample for measurement was placed in a differential scanning calorimetry (DSC) system [METTLER TOLEDO, Inc., product name: FP900 Thermo System (a system consisting of an FP90 Central Processor and an FP85 TA Cell)], held at -20°C until the system stabilized, then heated from -20°C to 70°C at a heating rate of 10°C / min (1st heating), and held at 70°C for 5 minutes. Next, it was cooled from 70°C to -20°C at a cooling rate of 10°C / min, and held at -20°C for 5 minutes. Again, it was heated from -20°C to 70°C at a heating rate of 10°C / min (2nd heating), and a DSC curve was obtained. The glass transition temperature (Tg) of each filament was determined from the DSC curve obtained from the 2nd heating.

[0101] [Shape Memory Test] In the following shape memory tests, "Tg" refers to the glass transition temperature (Tg) of each filament obtained from the glass transition temperature measurements described above. (shape retention) The filaments from Examples 1 to 7, as well as Comparative Example 1, were each cut to a length of 150 mm to prepare linear shape memory test specimens. The test sample was placed in a constant temperature bath set to (Tg+10)°C as the deformation temperature, heated for 5 minutes, removed from the bath, and wound around a 10 mm diameter cylinder to deform the test sample into a coil shape. Immediately afterward, it was placed in a constant temperature bath set to (Tg-10)°C as the fixing temperature and cooled for 5 minutes to fix the shape. Then, the test sample was removed from the constant temperature bath, detached from the cylinder, and immediately placed back into the constant temperature bath set to (Tg-10)°C. After 5 minutes, the test sample was removed from the constant temperature bath, and its shape retention (whether it maintained its deformed shape (coil shape)) was evaluated based on the size of the inner diameter of the coil formed by the test sample, according to the following criteria. The evaluation results are shown in Table 2. A: The inner diameter of the coil was 10 mm (equal to the outer diameter of the cylinder), and the test specimen maintained the same shape as the deformed shape. B: The inner diameter of the coil was greater than 10 mm and less than or equal to 15 mm. The test sample underwent a slight change in shape from its deformed form, but this was at a level that did not pose any practical problems. C: The inner diameter of the coil was greater than 15 mm, and the test specimen did not maintain the same shape as the deformed shape. Furthermore, for products that received a "C" rating for shape retention, the shape restoration test described later was not performed.

[0102] (Shape recovery) Next, the coil-shaped test samples, after their shape retention had been evaluated, were placed again in a constant temperature bath set to (Tg+10)°C. After 5 minutes, the test samples were removed from the constant temperature bath, and their shape recovery was visually confirmed to determine if they had returned to their original shape (a straight shape with a length of 150 mm). The shape of the test samples was then evaluated according to the following criteria. The evaluation results are shown in Table 2. A: The test specimen was restored from a deformed shape to a straight shape. B: The test specimen did not return to a straight shape from its deformed shape.

[0103] [Tensile test] The filaments from Examples 1 to 7, as well as Comparative Example 1, were each cut to a length of 150 mm to prepare specimens for tensile testing. In accordance with the tensile strength measurement method for filaments specified in JIS L1013, the test specimen was mounted on a tensile testing machine (manufactured by Imada Seisakusho Co., Ltd., product name: SDT-504F-R3) with a chuck distance of 50 mm. A load was applied at a tensile speed of 50 mm / min in a temperature environment of 23°C. The maximum stress generated before the test specimen fractured was defined as the tensile strength. If the test specimen did not fracture by the end of the test, the maximum stress generated during the test was defined as the tensile strength.

[0104] [Table 2]

[0105] Application Example 1 [Fabric making] The filaments from Example 2 were used as warp and weft threads, and the loom was set up to produce a plain weave fabric. The resulting fabric could be stretched in both the vertical and horizontal directions, had a flexible texture, and exhibited excellent durability.

[0106] Application Example 2 [Creation of head accessories (hair extensions)] Using 100 filaments from Example 3, cut to a length of 300 mm, hair extensions were fabricated by implanting them onto fasteners (clips) using a conventional method. The hair extensions described above initially had straight filaments, which provided both flexibility and excellent durability. Furthermore, when a straight filament (hair) was immersed in 39°C warm water and wrapped around a 9mm diameter cylindrical hair curler, and then immersed in 15°C cold water before the curler was removed, the hair curled to the same diameter as the curler and maintained that shape unless external force was applied. Furthermore, when the hair was straightened and then immersed again in 39°C hot water, and subsequently in 15°C cold water, the hair returned to its initial straight shape and could be easily restored to its original state. The hair extensions described above were able to withstand repeated bending deformation because of the superior mechanical strength of the filaments. Furthermore, when the initially straight-shaped hair was immersed in 39°C warm water and stretched to twice its length by the fingers, and then the external force applied by the fingers was removed while immersed in 15°C cold water, the hair maintained its shape as long as no external force was applied. Furthermore, when the hair was immersed again in 39°C warm water, it restored to its initial length. Then, when it was straightened by hand and immersed in 15°C cold water, it returned to its initial straight shape, easily returning to its original state. Because the hair extensions described above possessed excellent filamentary mechanical strength, they could be repeatedly stretched and deformed.

[0107] Application Example 3 [Making animal-shaped toys] Ten filaments from Example 7, cut to a length of 150 mm, were cooled to below 14°C. Then, the filaments were implanted onto the tail of a horse-shaped toy made of polyvinyl chloride using a conventional method (e.g., a flocking sewing machine) to create an animal-shaped toy. The filaments (hair) described above were initially straight in shape, possessing both flexibility and excellent durability. Furthermore, at room temperature (for example, 25°C), the color was purple, a mixture of blue from the microcapsule pigment and pink from the general pigment. When a straight strand of hair was immersed in 39°C warm water, the microcapsule pigment completely lost its color, and the hair changed from purple to pink. Then, after wrapping the hair around the outer circumference of a heart-shaped molded body while it was still immersed in warm water, the hair was removed from the molded body at room temperature (25°C), and the hair became heart-shaped, maintaining that shape for several minutes. When immersed in 10°C cold water, the microcapsule pigment fully developed its color, and the hair changed from pink to purple. Furthermore, when the hair was immersed again in 39°C water, the microcapsule pigment completely lost its color, and the hair changed from purple to pink. Subsequently, when the hair was left at room temperature (25°C) in a straightened shape, it returned to its initial straight shape and could be easily returned to its original state. When it was immersed again in 10°C water, the microcapsule pigment fully developed its color, and the hair changed from pink to purple. The hair described above exhibited excellent filamentous mechanical strength, allowing for repeated bending and deformation. Furthermore, when the initial straight-shaped hair was immersed in 39°C warm water, the microcapsule pigment completely lost its color, and the hair changed from purple to pink. Then, after being stretched and deformed to twice its length by fingers while immersed in warm water, it was immersed in 10°C cold water, and the microcapsule pigment fully developed its color, changing the hair from pink to purple. Finally, when the external force applied by fingers was removed while immersed in cold water, the hair maintained its shape as long as no further external force was applied. Furthermore, when the hair was immersed again in 39°C warm water, it restored to its initial length. Then, when it was straightened by hand and immersed in 15°C cold water, it returned to its initial straight shape, easily returning to its original state. Because the hair exhibited excellent filamentous mechanical strength, it could undergo repeated stretching and deformation. [Explanation of symbols]

[0108] T1 Full Color Temperature T2 color development start temperature t3 decolorization start temperature t4 complete color erasure temperature T1 complete discoloration temperature T2 decolorization start temperature T3 color development start temperature T4 Full Color Temperature ΔH Hysteresis width

Claims

1. The constituent units are derived from 4-methyl-1-pentene and C other than 4-methyl-1-pentene. ２－２０ A 4-methyl-1-pentene / α-olefin copolymer comprising a constituent unit derived from an α-olefin, Cellulose ester and, Consists of, Polyolefin filament.

2. The polyolefin filament according to claim 1, wherein the mass ratio of the 4-methyl-1-pentene / α-olefin copolymer to the cellulose ester is 99.9:0.1 to 50:

50.

3. The polyolefin filament according to claim 1, wherein the cellulose ester is one or more selected from the group consisting of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate.

4. A fabric made using the polyolefin filament described in any one of claims 1 to 3.

5. A head ornament comprising a polyolefin filament according to any one of claims 1 to 3.

6. A toy comprising a polyolefin filament according to any one of claims 1 to 3.

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