JP7323910B2 - Spun yarn, heat storage fiber structure, method for producing heat storage fiber structure, heat storage spun yarn, and method for producing heat storage spun yarn - Google Patents

Description

TECHNICAL FIELD The present invention relates to a spun yarn, a heat storage fiber structure, a method for producing a heat storage fiber structure, a heat storage spun yarn, and a method for producing a heat storage spun yarn. Specifically, the present invention relates to a spun yarn containing short fibers containing graphite silica fine powder (graphite silica-containing short fibers), a heat storage fiber structure, and the like.

Fibers containing fine powder of graphite silica are described, for example, in Patent Document 1 and the like. In Patent Document 1, "fibers containing 0.2 to 25% by weight of fine powder of graphite silica, the graphite silica is 350 g with 1 g of graphite silica particles having an average particle size of 70 to 80 µm sandwiched between upper and lower electrodes. The fiber has a resistance value of 9 × 10 ¹⁰ Ω or less in a state where a load of 1 is applied.", and it is stated that "a fiber excellent in heat storage and heat retention performance can be stably obtained." . Undergarments and clothing using fibers containing graphite silica have the excellent feature of being thin but warm due to the effect of far infrared rays.

On the other hand, Patent Document 2 describes "a composite fiber having a polyester having an equilibrium moisture content of 2% or less as a sea component and a water-soluble thermoplastic polyvinyl alcohol-based polymer containing 4 to 15 mol % of ethylene units as an island component. ” is disclosed. It states, "By dissolving and removing the water-soluble thermoplastic polyvinyl alcohol from this conjugate fiber, a hollow fiber can be obtained." The conditions for dissolving and removing the water-soluble thermoplastic polyvinyl alcohol are, for example, pre-setting at 170° C. for about 40 seconds, followed by hot water treatment at 120° C. for 40 minutes (paragraph 0056).

Japanese Patent Application Laid-Open No. 2017-020141 (Claims) Japanese Patent No. 4514977 (Claims)

Undergarments and clothing using fibers containing graphite silica have excellent heat storage properties and are warm even though they are thin. However, it has been desired to further reduce the weight and improve the bulging feeling while maintaining the heat storage property.

An object of the present invention is to solve the above-mentioned problems, and to provide a heat-storage fiber structure excellent in heat-storage properties and texture (lightness, softness, bulgeness).
Another object of the present invention is to provide a spun yarn used for this heat storage fiber structure and a method for producing the heat storage fiber structure.
Another object of the present invention is to provide a heat-storage spun yarn that can be used for heat-storage fiber structures.
Another object of the present invention is to provide a method for producing this heat storage spun yarn.

In order to solve the above problems, a water-soluble thermoplastic polyvinyl alcohol-based polymer is prepared by using graphite silica-containing short fibers containing graphite silica fine powder and a thermoplastic polymer having an equilibrium moisture content of 2% or less as a sea component. and a composite staple fiber having island components as a spun yarn.

The inventors of the present application have devoted themselves to research and development in order to improve the texture while maintaining the excellent heat storage properties of fibers containing graphite silica. Surprisingly, the inventors have found that the above problems can be solved by using a spun yarn composed of predetermined graphite-silica-containing short fibers and predetermined composite short fibers.
This spun yarn can be treated with water (hot water or hot water) in the state of a fiber structure or the like to dissolve and remove the water-soluble thermoplastic polyvinyl alcohol-based polymer, which is the island component of the composite short fibers. As a result, the conjugate short fibers become hollow short fibers, and a heat storage fiber structure is obtained from the fiber structure.
This heat-storage fiber structure achieves both heat-storage and texture due to the synergistic action of graphite silica and hollow fibers. In addition, when the spun yarn is treated with water, water acts from both ends of the composite short fiber, which is a short fiber. is dissolved away. Furthermore, this heat storage fiber structure does not get stuffy even when worn for a long time.

Here, the graphite silica-containing short fiber has a core-sheath structure consisting of a core component and a sheath component, and contains fine graphite silica powder only in the core component, and the content of the fine graphite silica powder is It can be a spun yarn that is 0.5 to 5.0% by weight of the graphitic silica-containing staple fiber.

Since the graphite silica-containing short fibers contain graphite silica fine powder only in the core component, when dissolving and removing the water-soluble thermoplastic polyvinyl alcohol polymer from the composite short fibers, the graphite silica-containing short fibers Fine powder of graphite silica is difficult to fall off from.
Further, when the content of graphite silica fine powder is 0.5 to 5.0% by weight of the graphite silica-containing short fiber, both heat storage property and texture can be achieved at a high level.

Alternatively, the spun yarn may contain 10 to 30% by weight of short fibers containing graphite silica and 50 to 90% by weight of composite short fibers.

This spun yarn can achieve both heat storage and texture at a high level. A spun yarn containing 15 to 30% by weight of short fibers containing graphite silica and 50 to 70% by weight of composite short fibers is preferably used.

Further, the above object is to provide at least one heat-storage spun yarn comprising graphite silica-containing short fibers containing graphite silica fine powder and hollow short fibers made of a thermoplastic polymer having an equilibrium moisture content of 2% or less. It can also be solved by the heat storage fiber structure included in the part.

A method for producing a heat-accumulating fibrous structure includes a spun yarn preparing step of preparing the spun yarn, and a fibrous structure using at least a part of the spun yarn prepared in the spun yarn preparing step. The fiber structure obtained in the manufacturing process and the fiber structure manufacturing process is treated with water to dissolve and remove the water-soluble thermoplastic polyvinyl alcohol-based polymer from the composite short fibers, thereby hollowing the composite short fibers. A method comprising a composite short fiber hollowing step of forming hollow short fibers. Water includes warm water and hot water.

Moreover, the above-mentioned problems are also solved by a heat-storage spun yarn composed of graphite silica-containing short fibers containing graphite silica fine powder and hollow short fibers made of a thermoplastic polymer having an equilibrium moisture content of 2% or less. do.

Furthermore, the above-mentioned problem is to solve the above problem by using graphite silica-containing short fibers containing fine powder of graphite silica, a thermoplastic polymer having an equilibrium moisture content of 2% or less as a sea component, and a water-soluble thermoplastic polyvinyl alcohol polymer as an island component. The problem can also be solved by a heat-storage spun yarn comprising hollow short fibers obtained by dissolving and removing the water-soluble thermoplastic polyvinyl alcohol-based polymer from the component composite short fibers.

At this time, the graphite silica-containing short fiber has a core-sheath structure consisting of a core component and a sheath component, and contains fine graphite silica powder only in the core component, and the content of the fine graphite silica powder is A heat-accumulating spun yarn containing 0.5 to 5.0% by weight of the short fiber containing graphite silica can be obtained.

It is also possible to provide a heat storage fibrous structure at least partially including the heat storage spun yarn.

The method for producing the heat-accumulating spun yarn includes a spun yarn preparation step for preparing the spun yarn, and the spun yarn prepared in this spun yarn preparation step is treated with water to convert the composite staple fiber into a water-soluble thermoplastic polyvinyl alcohol polymer. and a composite short fiber hollowing step of hollowing the composite short fibers into hollow short fibers by dissolving and removing the united fibers.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a heat-storage fiber structure having excellent heat-storage properties and texture.

FIG. 2 is a cross-sectional view showing an example of the cross-sectional shape of short fibers containing graphite silica. FIG. 2 is a cross-sectional view showing an example of a cross-sectional shape of a composite staple fiber; FIG. 2 is a cross-sectional view showing an example of a cross-sectional shape of short hollow fibers.

Hereinafter, a spun yarn, a heat storage fiber structure, a method for producing a heat storage fiber structure, a heat storage spun yarn, and a method for producing a heat storage spun yarn will be illustrated and explained. First, the spun yarn is illustrated and explained. The spun yarn contains graphite silica-containing staple fibers and composite staple fibers.
It should be noted that the following embodiments are for illustration and explanation of the present invention to the last, and the present invention is not limited to the following specific embodiments.

[Short fibers containing graphite silica]
Short fibers containing graphite silica are short fibers containing fine powder of graphite silica. Graphite-containing short fibers are obtained by making graphite-silica-containing fibers into short fibers. Graphite-containing fibers are described, for example, in JP-A-2017-020141 mentioned above.

1. Graphite Silica Graphite is believed to be diatoms that have accumulated on the seafloor over hundreds of millions of years and rise to the surface. Graphitic silica is based on SiO ₂ and contains graphite crystals (usually about 5%). In addition, graphite silica contains aluminum, potassium, titanium and iron dioxide and magnesium. Graphite silica is sometimes referred to as black silica.

2. Pulverization of graphite silica The graphite silica is pulverized. At this time, it is preferable to pulverize the graphite silica so that the average particle size (d50: cumulative 50% particle size) is 3 μm or less.

3. Fiberization (long fiber)
A graphite silica-containing fiber (long fiber) containing a predetermined amount of fine powder of graphite silica is produced.

The polymer constituting the graphite silica-containing fiber, that is, the polymer into which graphite silica fine powder is kneaded is not particularly limited. Polyethylene terephthalate, nylon 6, nylon 66, and the like are preferred in consideration of the threadability and yarn physical properties during spinning. In the case of a core-sheath type fiber, for example, two types of the above polymers can be selected, one of which can be used as the core component polymer and the other can be used as the sheath component polymer.

If many graphite silica particles are present near the surface of graphite silica-containing fibers, when dissolving and removing the water-soluble thermoplastic polyvinyl alcohol-based polymer from the composite staple fibers, depending on the water treatment temperature and time, the graphite silica particles may become fine. The powder may fall off from the fibers, which is not preferable. Therefore, it is preferable to form a so-called core-sheath type fiber in which graphite silica is added to the core component polymer and the periphery is covered with the sheath component polymer.

In the case of core-sheath type composite short fibers, the ratio (weight ratio) of the sheath component to the core component is preferably in the range of 4:1 to 1:4, more preferably in the range of 3:1 to 1:3. Preferably, the range of 2:1 to 1:1 is most preferred. Moreover, the core component does not have to be one core in the fiber, and may be two or more cores. Furthermore, a part of the core component may be exposed on the fiber surface, but it is preferable that the core component is completely covered with the sheath component.

The method of adding the graphite silica fine powder to the thermoplastic polymer is not particularly limited. A method of making master chips using a twin-screw extruder is preferable from the viewpoint of uniform dispersion.
The addition timing of the graphite silica fine powder is not particularly limited. It can be added to the reaction system at the initial stage of polymerization and directly spun. Also, a so-called post-addition system in which fine powder of graphite silica is kneaded with a polymer in a molten state may be employed. Furthermore, a so-called masterbatch system can be used in which a master chip containing a high concentration of fine powder of graphite silica is used.

The amount of graphite silica fine powder added is preferably 0.5 to 8.0% by weight of the graphite silica-containing fiber (graphite silica-containing short fiber), more preferably 0.5 to 5.0% by weight of the graphite silica-containing fiber. 0% by weight, more preferably 0.5 to 4.0% by weight of the graphite silica-containing fiber.

In order to fiberize graphite-silica containing fibers, it is possible to use the above-mentioned materials and use the normal fiber manufacturing process as it is. The fiber thickness is preferably in the range of 0.5 to 15 decitex.

The cross-sectional shape of the graphite silica-containing fiber is not particularly limited. In addition to the circular cross section, for example, a polygonal cross section such as a triangular to hexagonal cross section, a T-shaped cross section, and a U-shaped cross section can be used.

4. Making into Short Fibers The obtained graphite-silica stone-containing fibers are made into short fibers to obtain graphite-silica stone-containing short fibers. The fibers containing graphite silica can be made into short fibers by a conventionally known method. The fiber length of the graphite silica-containing short fibers is preferably 25-150 mm, more preferably 35-100 mm, and most preferably 40-60 mm. The number of crimps is preferably 12 to 15/inch for 3.3 decitex, and the crimp rate is preferably approximately 10%.

[Composite staple fiber]
Next, the composite short fibers will be described. The composite short fibers contain a thermoplastic polymer having an equilibrium moisture content of 2% or less as a sea component, and a water-soluble thermoplastic polyvinyl alcohol polymer as an island component. Composite short fibers are obtained by making composite fibers into short fibers. Composite fibers are disclosed in the aforementioned Japanese Patent No. 4,514,977. The contents described in Japanese Patent No. 4514977 can be applied to the island component material, the sea component material and fiberization.

The shapes of the sea component and the island component are not particularly limited. One or more island components may be present in the cross section of the composite staple fiber. The number of island components can be, for example, 10 or more, further 30 or more, particularly 50 or more. Although the upper limit of the number of island components is not particularly limited, considering the fiber strength, it is preferably 1000 or less, more preferably 600 or less.

The composite ratio of the island component and the sea component is not particularly limited. The composite ratio can be changed according to the number of hollow portions of the hollow short fibers and the degree of hollowness to be set. If the ratio of the island component is too small, the effect of weight reduction is also reduced. On the other hand, if the ratio of the hollow portion is too large, it becomes difficult to secure the strength. The composite ratio (weight ratio) of the sea component and the island component is preferably sea:island=98:2 to 35:65, more preferably 95:5 to 40:60, and 70:30 to 50:50. is most preferred.
Moreover, the cross-sectional shape of the composite staple fiber is not particularly limited. The cross-sectional shape of the conjugate staple fiber can be circular, flat, elliptical, or polygonal, for example.
In addition, the composite short fibers may contain various additives. Additives include, for example, optical brighteners, stabilizers, flame retardants, and colorants.

1. Island Component The water-soluble thermoplastic polyvinyl alcohol-based polymer (hereinafter sometimes referred to as PVA) used for the island component of the composite staple fiber will be described. PVA includes homopolymers of polyvinyl alcohol as well as modified polyvinyl alcohol into which functional groups have been introduced by copolymerization, terminal modification, and post-reaction, for example.

The viscosity average degree of polymerization of PVA is preferably 200-500, more preferably 230-470, even more preferably 250-450. By using PVA with a low degree of polymerization having a viscosity-average degree of polymerization of 500 or less, the dissolution rate of PVA is increased. In addition, by using PVA with a low degree of polymerization having a viscosity average degree of polymerization of 500 or less, shrinkage of the short composite fibers during dissolution can be reduced. The viscosity average degree of polymerization is measured according to JIS-K6726.

The saponification degree of PVA is preferably 90 to 99.99 mol %. If the degree of saponification is less than 90 mol %, the water solubility of PVA may decrease depending on the type of copolymerizable monomer.

The melting point (Tm) of PVA is preferably 160 to 230°C, more preferably 170 to 227°C, even more preferably 175 to 224°C, most preferably 180 to 220°C. If the melting point is less than 160° C., the crystallinity of PVA is lowered, and the fiber strength and thermal stability of the conjugated fiber are deteriorated, and fiberization may not be possible. On the other hand, when the melting point exceeds 230° C., the spinning temperature becomes high, and the spinning temperature approaches the decomposition temperature of PVA, which may prevent stable fiberization.
The melting point of PVA is measured using DSC. Specifically, after heating to 250°C at a heating rate of 10°C/min in nitrogen, cooling to room temperature, and then heating again to 250°C at a heating rate of 10°C/min, the peak top of the endothermic peak. is measured, and this temperature is taken as the melting point of PVA.

Ethylene-modified PVA into which 4 to 15 mol %, preferably 6 to 13 mol % of ethylene units are introduced can be used as PVA. Such PVA has high fibrous physical properties.

By changing the type of PVA and the manufacturing conditions of the conjugate fiber, it is possible to obtain a conjugate fiber in which the island component PVA has a melting temperature of 30°C to 100°C. The melting temperature of PVA is preferably 40° C. or higher.

2. Sea Component The thermoplastic polymer that constitutes the sea component of the conjugate staple fiber is not particularly limited as long as it has an equilibrium moisture content of 2% or less. For example, polyolefin polymers such as polyethylene, polypropylene, and polymethylpentene; polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, and polypropylene terephthalate; Examples include vinyl chloride, polyvinylidene chloride, polyurethane, polybutadiene, hydrogenated polybutadiene, polyisoprene, hydrogenated polyisoprene, copolymers of aromatic vinyl monomers and diene monomers, and hydrogenated products thereof.
Moreover, these polymers may be modified by copolymerization or the like. In a polyester system, copolymerization with isophthalic acid, 5-sodium sulfoisophthalic acid, sebacic acid, adipic acid or the like is preferable because it facilitates dissolution and removal of PVA. Furthermore, the sea component may contain various additives.
The equilibrium moisture content is a value measured according to the method for measuring 7.3 "equilibrium moisture content" of JIS L1015-1992. The water balance in the measurement is under the conditions of a temperature of 20° C.±2° C. and a humidity of 65% RH±2% RH.

3. Composite fiber fiberization (long fiber)
Composite spinning, for example, can be used as a method for fiberizing composite fibers. In the case of composite spinning, the PVA and the thermoplastic polymer are melt-kneaded in separate extruders, and then extruded from a sea-island type composite spinning nozzle so that the PVA serves as an island component and the thermoplastic polymer serves as a sea component. It is preferable to fiberize by winding up.

4. Shortening of composite fibers (short composite fibers)
The obtained composite fibers are made into short fibers to obtain composite short fibers. It can be made into short fibers by a conventionally known method. The fiber length of the conjugate short fibers is preferably 25-150 mm, more preferably 35-100 mm, and most preferably 40-60 mm. For example, in the case of 3.3 decitex, the number of crimps is preferably 12 to 15/inch, and the crimp rate is preferably about 10%.

[Spun Yarn]
A spun yarn is obtained by blending the graphite silica-containing staple fibers and the composite staple fibers. The blending method is not particularly limited. For example, a spun yarn can be obtained by passing graphitic silica-containing short fibers and composite short fibers through a card (carding machine) and blending them at a predetermined ratio. Here, in addition to the graphite silica-containing short fibers and composite short fibers, other fibers may be blended. For example, short acrylic fibers can be used.
In the blend spinning, it is preferable to use 10 to 30% by weight of graphite-silica-containing staple fibers and 50 to 90% by weight of composite staple fibers from the viewpoint of texture (lightness, softness, bulgeness) and heat storage properties. When acrylic short fibers are blended, the amount is preferably 35% by weight or less, more preferably 20% by weight or less, based on the total spun yarn.

[Method for producing heat storage fiber structure]
Next, a method for producing a heat-storage fiber structure will be described by way of example. A method for producing a heat-storage fiber structure includes a spun yarn preparation step, a fiber structure production step, and a composite short fiber hollowing step.

The spun yarn described above is prepared in the spun yarn preparation step. In the subsequent fiber structure production step, the spun yarn prepared in the spun yarn preparation step is used at least in part to produce a fiber structure.
Textile structures include woven and knitted fabrics, non-woven fabrics, paper, artificial leather, and filling materials, as well as interwoven fabrics, interwoven fabrics, fiber laminates, clothing made from these, living materials, industrial materials, medical supplies, etc. Also includes various final products of These fiber structures can be produced, for example, by conventionally known methods.

In the composite staple fiber hollowing step, the fiber structure obtained in the fiber structure manufacturing step is treated with water (hot water) to dissolve and remove the water-soluble thermoplastic polyvinyl alcohol polymer (PVA) from the composite staple fiber. As a result, the composite staple fibers in the spun yarn are hollowed (hollow staple fibers).

The water treatment temperature for dissolving and removing PVA may be appropriately adjusted according to the dissolution temperature of PVA. The higher the water temperature, the shorter the time required to dissolve and remove the PVA. The water temperature is 60°C or higher, preferably 80°C or higher. If the glass transition point of the thermoplastic polymer to be the sea component is 70° C. or higher, water treatment at a temperature of 100° C. or higher and under high pressure is most preferable. As a water treatment method, for example, the fiber structure can be immersed in water. Water used for water treatment may be an alkaline aqueous solution or an acidic aqueous solution, and may contain a surfactant or the like.

The treatment time of the water treatment can be appropriately adjusted depending on the water temperature, the fineness of the composite fiber, the ratio of the island component, the state of distribution of the island component, and the like.

Water treatment selectively removes PVA in the short composite fibers. As a result, the conjugate short fibers in the spun yarn are hollowed (hollow short fibers) to produce a heat-storage fiber structure.

It is preferable that the area ratio of the hollow portion in the cross section of the hollow short fiber (hereinafter sometimes referred to as the hollow ratio) is 2% or more. If the hollowness is less than 2%, the feeling of lightness and swelling may be insufficient. The hollowness is preferably 5% or more, more preferably 20% or more, still more preferably 30% or more.
If the hollowness is too large, the fiber strength may be insufficient. The hollowness is preferably 70% or less, more preferably 65% or less, still more preferably 50% or less.

[Method for producing heat storage spun yarn]
In the above description, an example of dissolving and removing PVA from the composite short fibers by water-treating the fiber structure was given. However, the spun yarn can also be treated with water to dissolve and remove the PVA from the composite short fibers. Composite short fibers hollowed out by dissolving and removing PVA become heat-storage spun yarns. A method for producing a heat storage spun yarn includes a spun yarn preparation step and a composite short fiber hollowing step.

The spun yarn described above is prepared in the spun yarn preparation step. In the next composite staple fiber hollowing step, the spun yarn prepared in the spun yarn preparation step is treated with water to dissolve and remove PVA from the composite staple fiber. As a result, the composite short fibers become hollow short fibers.

A heat-storage fiber structure can be produced using the heat-storage spun yarn. Since PVA is dissolved and removed from the obtained heat-storage fiber structure, water treatment is basically unnecessary.

EXAMPLES Next, the present invention will be specifically described using Examples, but the present invention is not limited to these. The ratios and percentages in the examples relate to weight unless otherwise indicated.

[Example 1]
Graphite-containing fiber with a core-sheath structure in which polyester to which 10% by weight of graphite silica fine powder (average particle size 0.6 μm) is added is used as a core component, and polyester is used as a sheath component (ratio of sheath/core = 2/1, A stretched system of 83 dtex/24 f) was obtained. This was combined into a fiber tow of 400,000 denier, crimped using an indentation crimper and cut into 51 mm, and a short fiber containing graphite silica with a single filament fineness of 3 denier (the number of crimps was 12.0). / inch).
On the other hand, ethylene-modified PVA was used as the island component, and polyethylene terephthalate modified with 6 mol% isophthalic acid containing 0.045% by weight of titanium oxide (intrinsic viscosity [η] = 0.68, equilibrium moisture content 0.4%) was used as the sea component. After spinning at a spinning temperature of 260° C. and a spinning speed of 1800 m/min using a composite spinning part in which the PVA zone maximum temperature is 230° C. and the PVA melt retention is minimized, the undrawn yarn is transferred to a hot roller at 83° C. and a hot plate at 140° C. and drawn at a draw ratio of 2.3 to obtain a composite fiber of 83 dtex/24 f. The resulting conjugated fibers are combined into a 400,000 denier fiber tow, crimped using a press crimper and cut to 51 mm, and conjugated staple fibers with a single filament fineness of 3 denier (the number of crimps is 12). .0 pieces/inch).
The graphite silica-containing staple fibers and the composite staple fibers were passed through a card (carding machine) and blended at a ratio of 30:70 to obtain a 20 count spun yarn.
The obtained spun yarn is used to prepare a jersey knitted fabric, and the jersey knitted fabric is immersed in an aqueous solution containing 2 g/liter of sodium carbonate at 80°C for 30 minutes for desizing, and then at 170°C for about 40 seconds. I did a preset. Next, hot water treatment was performed with an aqueous solution containing 1 g/liter of Intoll MT Conc (anionic surfactant, manufactured by Meisei Chemical Co., Ltd.) at a bath ratio of 50:1 at a temperature of 120° C. for 40 minutes. After thoroughly washing with water, a top knitted fabric (heat storage fiber structure) was obtained.
It was confirmed that PVA, which is an island component of the conjugated short fibers, was almost completely dissolved and removed, and the conjugated short fibers became hollow short fibers. In addition, it was not confirmed that the graphite silica fine powder fell off during the presetting or hot water treatment.

The texture (lightness, softness, bulgeness) of the obtained top hat knitted fabric was evaluated according to the following criteria [texture evaluation]
The woven fabric was tested by 10 panelists and evaluated according to the following criteria.
◎: Judgment that 9 or more people have excellent feeling of lightness, softness, and swelling ○: Judgment that 7-8 people have excellent feeling of lightness, softness, and swelling △: Judgment that 5-6 people have lightness , Judgment that both softness and swelling are excellent ×: Judgment that 6 or more people are inferior in both lightness, softness, and swelling

In addition, the heat storage property of the obtained top hat knitted fabric was evaluated according to the following criteria.
[Heat storage evaluation]
The woven fabric was tested by 10 panelists and evaluated according to the following criteria.
◎: Judgment that 9 or more people are excellent in heat storage ○: Judgment that 7 to 8 people are excellent in heat storage △: Judgment that 5 to 6 people are excellent in heat storage ×: 6 or more Determined to be inferior in heat storage

Table 1 shows the evaluation results.

評価の結果、得られた天竺編物は、風合い（軽量感、ソフト感、ふくらみ感）、蓄熱性ともに優れていた。また、長時間の着用でも蒸れにくいとの評価であった。

As a result of the evaluation, the obtained cotton sheeting knitted fabric was excellent in both texture (lightness, softness, bulgeness) and heat storage properties. In addition, it was evaluated that it does not get stuffy even when worn for a long time.

[Example 2]
In the short fibers containing graphite silica of Example 1, the sheath/core ratio was changed from 2/1 to 1/1. Other than that, the same materials and conditions as in Example 1 were used to obtain a spun yarn and a top knitted fabric. By changing the sheath/core ratio from 2/1 to 1/1, the content of graphite silica in the fiber is increased from 3.3% by weight to 5.0% by weight.
Also in this example, it was confirmed that the PVA, which is the island component of the conjugated short fibers, was almost completely dissolved and removed, and the conjugated short fibers became hollow short fibers. In addition, it was not confirmed that fine powder of graphite silica was dropped off during presetting or hot water treatment.
The obtained cotton sheeting knitted fabric was excellent in both texture (lightness, softness and bulgeness) and heat storage properties. In addition, it was evaluated that it does not get stuffy even when worn for a long time.

[Example 3]
In the graphite silica-containing short fibers of Example 2, the graphite silica content ratio (in the core component) was changed from 10% by weight to 5% by weight. Also, in the composite short fibers of Example 2, the sea component was changed to PBT (polybutylene terephthalate). The PBT used for the sea component has an equilibrium moisture content of 2% or less. Furthermore, short acrylic fibers (fiber length: 51 mm) were used as other fibers. A spun yarn was obtained by blending 15% by weight of short fibers containing graphite silica, 50% by weight of composite short fibers, and 35% by weight of acrylic short fibers. A top hat knitted fabric was obtained using the same materials and conditions as in Example 2 except for the above.
Also in this example, it was confirmed that the PVA, which is the island component of the conjugated short fibers, was almost completely dissolved and removed, and the conjugated short fibers became hollow short fibers. In addition, it was not confirmed that fine powder of graphite silica was dropped off during presetting or hot water treatment.
The obtained cotton sheeting knitted fabric was excellent in both texture (lightness, softness and bulgeness) and heat storage properties. In addition, it was evaluated that it does not get stuffy even when worn for a long time.

[Example 4]
In the short fibers containing graphite silica of Example 1, the core component was changed from polyethylene terephthalate to nylon 6. In addition, in the composite short fibers of Example 1, the sea component was changed to PBT (polybutylene terephthalate). Furthermore, short acrylic fibers (fiber length: 51 mm) were used as other fibers. A spun yarn was obtained by blending 30% by weight of short fibers containing graphite silica, 50% by weight of composite short fibers, and 20% by weight of acrylic short fibers. Other than that, the same materials and conditions as in Example 1 were used to obtain a top knitted fabric.
Also in this example, it was confirmed that the PVA, which is the island component of the conjugated short fibers, was almost completely dissolved and removed, and the conjugated short fibers became hollow short fibers. In addition, it was not confirmed that fine powder of graphite silica was dropped off during presetting or hot water treatment.
The obtained cotton sheeting knitted fabric was excellent in both texture (lightness, softness and bulgeness) and heat storage properties. In addition, it was evaluated that it does not get stuffy even when worn for a long time.

[Example 5]
In the graphite silica-containing short fibers of Example 2, the graphite silica content ratio (in the core component) was changed from 10% by weight to 2% by weight. A top hat knitted fabric was obtained using the same materials and conditions as in Example 2 except for the above.
Also in this example, it was confirmed that the PVA, which is the island component of the conjugated short fibers, was almost completely dissolved and removed, and the conjugated short fibers became hollow short fibers. In addition, it was not confirmed that fine powder of graphite silica was dropped off during presetting or hot water treatment.
The obtained cotton sheeting knitted fabric was excellent in both texture (lightness, softness and bulgeness) and heat storage properties. In addition, it was evaluated that it does not get stuffy even when worn for a long time.

[Comparative Example 1]
In the graphite silica-containing short fibers of Example 2, the graphite silica content ratio (in the core component) was changed from 10% by weight to 50% by weight. However, disconnection frequently occurred during the fiberization process of graphite-silica containing fibers. In the composite short fibers of Example 2, the sea/island ratio (composite ratio) was changed from 70/30 to 50/50. There were also difficulties in the fiberization process. For these reasons, sample evaluation was discontinued.

[Comparative Example 2]
In the graphite silica-containing short fibers of Example 2, the graphite silica content ratio (in the core component) was changed from 10% by weight to 0.5% by weight. Other than that, the same materials and conditions as in Example 2 were used to obtain a spun yarn and top knitted fabric.
The resulting jersey knitted fabric was excellent in texture, but inferior in heat storage properties.

[Comparative Example 3]
In Example 1, acrylic staple fibers (fiber length: 51 mm) were used instead of composite staple fibers to obtain a spun yarn and a top knitted fabric.
The resulting jersey knitted fabric had excellent heat storage properties, but lacked a feeling of lightness and was inferior in texture. However, it was evaluated that it does not get stuffy even when worn for a long time.

[Comparative Example 4]
In Example 1, acrylic short fibers (fiber length: 51 mm) were used instead of graphite-silica-containing short fibers to obtain a spun yarn and a knitted fabric.
The resulting jersey knitted fabric was excellent in lightness, but was significantly inferior in heat storage properties.

Although the present invention has been described above with reference to specific embodiments and examples, the present invention is not limited to the above embodiments, and is attached to the application of the present application by those skilled in the art. Various changes and modifications are possible without departing from the scope of the claims.

The heat-storage fiber structure of the present invention obtained in this way is excellent in heat-storage and texture (lightness, softness, bulgeness), and can be used for woven and knitted fabrics, nonwoven fabrics, paper, artificial leather, filling materials, It can be used as a woven fabric, a knitted fabric, a fiber laminate, and various products such as clothing, living materials, industrial materials, medical supplies, etc., composed of these.

1 Short fibers containing graphite silica
11 core components
12 Sheath Component
13 Fine graphite silica powder 2 Composite staple fiber
21 sea component
22 Island component 3 Hollow staple fiber
30 Hollow part

Claims (5)

graphite silica-containing short fibers containing fine powder of graphite silica;
A spun yarn comprising composite short fibers having a thermoplastic polymer having an equilibrium moisture content of 2% or less as a sea component and a water-soluble thermoplastic polyvinyl alcohol polymer as an island component ,
The short fibers containing graphite silica are
It has a core-sheath structure consisting of a core component and a sheath component, and contains the graphite silica fine powder only in the core component, and the content of the graphite silica fine powder is 1 of the graphite silica-containing short fibers. .0 to 5.0% by weight,
15 to 30% by weight of the short fiber containing graphite silica is contained,
50 to 70% by weight of the composite staple fiber is contained,
The composite staple fiber has 10 to 600 island components in its cross section.
spun yarn.
A spun yarn preparing step for preparing the spun yarn according to claim 1 ;
a fiber structure manufacturing step of manufacturing a fiber structure using at least a part of the spun yarn prepared in the spun yarn preparing step;
The fiber structure obtained in this fiber structure manufacturing process is treated with water to dissolve and remove the water-soluble thermoplastic polyvinyl alcohol polymer from the composite short fibers, thereby hollowing the composite short fibers into hollow short fibers. a composite short fiber hollowing step;
A method for producing a heat storage fiber structure.
A spun yarn preparing step for preparing the spun yarn according to claim 1 ;
The spun yarn prepared in this spun yarn preparation step is treated with water to dissolve and remove the water-soluble thermoplastic polyvinyl alcohol polymer from the composite short fibers, thereby making the composite short fibers into hollow short fibers. a fiber hollowing step;
A method for producing a heat storage spun yarn.
2. The heat-storage spun yarn according to claim 1, which is obtained by removing the island component from the composite staple fiber to obtain hollow staple fibers.
At least a part of which contains the heat storage spun yarn according to claim 4 ,
A heat-storage fiber structure.