JPH11113783A - Towel for bath - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a towel for bath which has a squeaking feel and improved use feel and is degradable in a relatively short period of time into soil, activated sludge and compost when discarded by forming the towel for bath by using polylactic acid fibers having specific optical purity as warp and weft, respectively. SOLUTION: The towel for bath formed which is formed by using the polylactic acid fibers and has an excellent biodegradation characteristic is formed by using at least 50 wt.% polylactic acid fibers having the optical purity of >=90% as the warp and the weft, respectively. The polylactic acid fibers used for the warp is preferably polylactic acid monofilaments of 20 to 100 d. Polylactic acid finished yarn of 75 to 500 d is used for at least part of the polylactic acid fibers used as the weft. The component of such towel cloth consists of natural fibers at preferably >=2/3 the non-polylactic acid fibers components. Plural kinds of the fibers are blended and used as the fibers in order to improve the use feel, durability, etc. The use feel and the durability may be improved particularly in the case of blended use of the fibers having the high fineness and the fibers having the fine fineness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bath towel using polylactic acid fibers and having excellent biodegradability.

[0002]

2. Description of the Related Art Natural fibers such as cotton, hemp and silk have been used for bath towels. Further, in recent years, synthetic fiber products such as nylon, polypropylene, and vinylidene chloride have been developed.

Conventionally used towels made of natural fibers such as cotton, hemp, silk, etc., have poor durability due to poor durability of the fibers themselves, blackening / yellowing during use for a long period of time. In some cases, mold may occur, or the strength may be easily reduced and the film may be broken, resulting in poor practical usability. On the other hand, towels made of synthetic fibers such as nylon, polypropylene, and vinylidene chloride have improved durability, but have poor usability, and have problems such as changes in quality such as yellowing and darkening. In particular, the stiffness of the synthetic fibers is severely irritating to the skin and may cause skin disorders such as melasma. Furthermore, the impact of waste materials on the environment, which has been attracting attention in recent years, cannot be ignored.

[0004] Bath towels made of synthetic fibers are much cheaper and can be supplied stably in comparison with those using natural fibers in terms of cost and supply. However, there are difficulties that conventional natural fibers do not have, such as almost no permanent degradation. That is, it does not decompose in normal disposal and remains semipermanently in its form,
Also, when incinerated, it generates a great deal of combustion heat, damages the incinerator, increases the amount of NO _x and SO _{x in} the exhaust gas,
Or it may generate carcinogenic dioxin.

[0005]

DISCLOSURE OF THE INVENTION The present invention has a stable quality and a stable supply, has a feeling of tingling and is excellent in usability, and can be compared in soil, activated sludge and compost at the time of disposal. or decompose within a specific short time, or does not generate toxic gases during incineration, also friendly bath towel environment that minimized the occurrence of harmful NO _X and SO _X for low combustion heat to the cellulose parallel The purpose is to propose.

[0006]

SUMMARY OF THE INVENTION The present invention is a bath towel using at least 50% by weight of a polylactic acid fiber having an optical purity of 90% or more for each of a warp and a weft. The bath towel is a towel mainly used for scouring in a bathroom.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical purity (hereinafter abbreviated as OP) of polylactic acid used in the present invention is usually 90% or more.
It is preferably at least 94%, more preferably at least 96%, particularly preferably at least 98%. If the OP does not reach 90%, the crystallinity of the polymer is low and the crystallization speed is low, so that yarn breakage is likely to occur during fiber production, and the operability is lowered and the crystallinity of the obtained fiber is also lowered. In addition, there are problems in the production process and problems during use, such as low fiber strength, lack of thermal stability, and change in dyeability. In addition, there is a problem that the heat setting property at the time of making knit / denit which is indispensable for the production of toweling is poor, so that a good crimp yarn cannot be produced, or a bulky yarn such as a wooly-processed yarn cannot be produced. . When OP is 90% or more, the crystallinity is good, and the above-mentioned problems are few. In particular, when the OP is 98% or more, the crystallinity of the fiber is particularly excellent, there are few problems during fiber production, and the strength and heat resistance of the obtained fiber, and the setting property in knit / denit are extremely good.

In general, polylactic acid is an optical isomer of L-
It is a polymer (copolymer in a broad sense) in which isomer and D-isomer of lactic acid are mixed, and the optical purity of polylactic acid is determined by their ratio. The body of living organisms in nature consists mostly of L-compounds,
Therefore, there are abundant enzymes that degrade L-form polymers and compounds. However, D-forms hardly exist in nature, and polymers and compounds containing a large amount of D-forms are hardly decomposed in nature. Therefore, the poly-lactic acid fiber of the present invention is also preferably poly-L-lactic acid having a high L-lactic acid content.

Therefore, in the composition of the polylactic acid fiber, the biodegradability decreases as the ratio of the D-form increases. In this sense, a higher OP is preferable.

Polylactic acid fibers are produced by melt-spinning or solution-spinning polylactic acid. Melt-spinning is preferable in that it has a low production efficiency, a wide variety of products, and a small load on the environment during production.

In the melt spinning, a polylactic acid resin is heated and melted to a temperature equal to or higher than its melting point, and discharged and cooled into the air from a spinneret having minute holes to produce fibers. The discharged and cooled fiber is wound up in order to go to the next step. In the case of long fiber, the winding speed is a conventional method called POY (Party) in which the winding speed is about 2000 m / min or less.
a method of winding at a winding speed of about 5500 m / min or less, which is referred to as an HYY method.
(Highly Oriented Yarn) method, a method in which the winding speed is about 5500 m / min or more, or SPD (Spi) in which drawing is performed immediately after spinning using the same apparatus.
n Draw) method or the like can be adopted. Also, in the case of short fibers, in order to extrude from many nozzles overwhelmingly compared to long fibers
Winding speed is usually slower than long fiber,
Usually, it is performed at 2000 m / min or less. In particular, 1500
Most commonly, it is performed at m / min or less.

In the towel of the present invention, at least 50% by weight of a polylactic acid fiber is used for each of the warp and the weft of the woven fabric. Other components of the towel (hereinafter, abbreviated as “non-polylactic acid fiber component”) may be conventional synthetic fibers or natural fibers. Preferably, the majority of the non-polylactic acid fiber components are natural fibers, more preferably 2/3 or more are natural fibers, particularly preferably all are natural fibers.
If the polylactic acid fiber content is less than 50% of the towel, there is no improvement in durability and usability or poor biodegradability.

The polylactic acid fiber used in the present invention may be any of ordinary cross-section fibers, flat cross-section fibers, cross-section fibers, hollow cross-section fibers (繊 維, Δ), and non-circular cross-section fibers such as U-section fibers. Fiber cross sections can also be used. Taking the feeling of use into consideration, it is also possible to use a mixture of fibers having irregular cross-sections such as a flat cross-section fiber, a △ cross-section fiber, and a U cross-section fiber, rather than a simple cross-section fiber. In order to improve the texture, swelling, detergency, foaming property, etc., the fiber of irregular cross section should be about 10% or more, preferably 2% or more.
0% or more, more preferably 30% or more is mixed. In the case of mixing, a method of a mixed fiber may be used, but it may be used as a warp or a weft of a woven fabric or a part thereof.

[0014] The thickness of the polylactic acid fiber is usually 1
5 to 150d monofilament or single yarn denier 2
~ 30d multifilament, preferably 20 ~ 10
0d monofilament or single yarn denier 3-25d
And more preferably 25 to 75d monofilament or single yarn denier 4 to 20d multifilament. Whether to use a monofilament or a multifilament can be determined according to the application and target performance. In the case of the multifilament, a non-twisted yarn, a sweet twisted yarn or a medium twisted yarn can be used, but it is preferable to use a non-twisted yarn from the viewpoint of cost.

The polylactic acid fiber used for the weft of the towel of the present invention is usually a multifilament of 50 to 700 d, preferably a multifilament of 75 to 500 d, and more preferably a multifilament of 100 to 400 d. The single yarn denier is usually 3 to 15 d, but other than this range, it can be used depending on the purpose and application. Since the weft has an important role in the effect of washing and touching the towel, crimped yarn by knit / denit method, crimped yarn by staffin method, crimped yarn by gear method, or crimped yarn by Panlon method , And the like, it is preferable to use a processed yarn such as a spiral crimped yarn by side-by-side composite yarn, or a false twisted yarn, but among them, a false twisted yarn called a wooly yarn, Or a knit / denit yarn is particularly preferred. One type of fiber may be used, or several types of fiber may be mixed and used for improving texture, feeling of use, and durability. In particular, if a mixture of a fiber having a large fineness and a fiber having a small fineness is used, the feeling in use and the durability are improved. In the combination of these fibers, the difference in fineness and the shrinkage rate of each fiber (for example,
By changing the thermal shrinkage ratio), the yarn itself has a swelling, and a plump texture and a soft feeling of use can be produced, which is more preferable. In particular, this effect can be more remarkably exhibited by setting the shrinkage of the fine-fiber yarn to be large and the shrinkage of the fine-fine yarn to be low.

When short fibers of polylactic acid are used, spun yarns of 100% polylactic acid fibers as well as other fibers, for example, natural fibers such as cotton, hemp, silk, nylon, polyester and acrylic fibers are blended. Can also be used. However, from the viewpoint of environmental load, it is preferable to use natural fibers as the blending partner. By mixing and using staple fibers of polylactic acid fibers having different fineness or fibers having different hot water shrinkage rates, richer texture, feeling of use, durability and the like can be exhibited.

In the towel of the present invention, as described above, polylactic acid fibers or a blend yarn of polylactic acid fibers and other fibers can be used, and further, other synthetic fibers or natural fibers are included in these fibers. It can be woven to express a woven pattern and heterochromatic properties during dyeing.

The structure of the woven fabric is not particularly limited as long as it is a woven structure usually used for toweling. For example, a normal plain weave, twill weave, or satin weave can be used, and those with a change in texture can also be used. In addition, it is usually a single woven fabric,
Double woven fabrics are also possible for a luxurious look. In particular, in the case of cross-weaving with other fibers, it is preferable to use a structure other than plain weave in order to change the type of yarn to be exposed on the surface according to the characteristics of the fibers. For example, when a softer fiber is used for the weft and a soft texture is obtained, it is preferable that the twill or satin weave has a structure in which a larger amount of weft is output.

The density of the woven fabric is usually from 3 to 50 yarns / inch, preferably from 5 to 40 yarns / inch, more preferably from 10 to 30 yarns / inch. The weft is usually 15 to 5
0 / inch, preferably 18-45 / inch, more preferably 20-40 / inch.

For dyeing, 100% polylactic acid fiber can be dyed with a disperse dye at a temperature of 95 to 120 ° C., but polylactic acid fiber has slightly lower color fastness than conventional polyester fiber. However, by properly selecting the dye, the color fastness can be maintained. For example, those having a medium hardness (SF-F type) are preferable.
The staining concentration can be appropriately selected depending on the use and purpose. In the case of towels mixed with other fibers or mixed with other fibers, when dyeing other fibers, they can be dyed by two-bath dyeing or by one-bath dyeing simultaneously with dyes of other fibers. At the time of dyeing or after dyeing, it is also possible to process ultraviolet absorbers, slip agents, antibacterial agents, and the like. In particular, in order to improve the light fastness, it is preferable to use an ultraviolet absorber in an amount of 1% / owf or more.

The bath towel according to the present invention is excellent in biodegradability when discarded after use, and has a heat of combustion of 34 even in the case of incineration.
To be comparable to 00~3500cal / g and a newspaper, can not be to generate toxic gases such as gas and dioxin of NO _X and SO _X, etc. or damage to the furnace, it can also be easily incinerated. Because it is biodegradable, it can be buried in a corner of a home garden, processed with a home composting machine, or easily composted at a local composting plant. In this respect, the bath towel of the present invention can be said to be a very environmentally friendly material.

[0022]

The present invention will be described in detail with reference to the following examples. In the examples, “parts” means “parts by weight” unless otherwise specified, and “%” means “% by weight” unless otherwise specified. Relative viscosity: ηrel was determined by a conventional method at 20 ° C. in a mixed solvent of phenol / tetrachloroethane = 6/4 (weight ratio). The melting point (Tm) is measured by an endothermic peak of a differential scanning calorimeter (hereinafter referred to as DSC) manufactured by Rigaku Denki.
It was determined from the peak value of the peak.

Example 1 The content of L-lactic acid was 99.2%, ηrel = 3.1,
Polylactic acid having a weight average molecular weight of 130,000 and a melting point of 175 ° C.
Melted at a melting temperature of 30 ° C, pore size 0.25mm, number of holes
Extruded into the air from a spinning nozzle having 48
Spin at 75d / 24f by filament method
Separated filaments were obtained. 400d for a single pick
/ 48f filament was obtained. Each has a strength of 4.5 g /
d, 4.2 g / d, elongation 34%, 37%, elastic modulus 685
Kg / mm^Two, 645 Kg / mm ^TwoHas the physical properties of
Was. 75d / 24f yarn puts 300T / m torque
Used as warp. Also, 400d / 48f yarn is tubular knitting
After heat-treating the product at 110 ° C for 40 minutes, it is denitized and crimped.
And used as weft. Using the fiber, sutra: 10 /
Inch, weft: Weft yarn is exposed with 35 / inch yarn design
In this way, a satin fabric was manufactured. Bath towel of the fabric
As the performance, the friction with the skin is very soft,
The foaming of the soap was also good. Draining after use
The property was also good, and it was possible to sufficiently dry indoors.

Example 2 Polylactic acid having an L-lactic acid content of 99.1%, ηrel = 3.3, a weight average molecular weight of 150,000 and a melting point of 173 ° C.
Melted at a melting temperature of 35 ° C, pore diameter 0.3 mm, number of holes 1
The mixture was extruded into the air from a spinning nozzle having two filaments, and spun by a normal filament method to obtain a 30d / 1f monofilament for 12-split. 40 as in the first embodiment.
A filament of 0d / 24f was obtained. Each with a strength of 4.0
g / d, 4.3 g / d, elongation 38%, 36%, elastic modulus 6
It had physical properties of 17 kg / mm ² and 640 kg / mm ² . The 30d / 1f monofilament is used as a warp as it is. For 400d / 24f, a weft yarn having a false twist of about 1500 T / m inserted by a spindle type false twister is used as one of ten weft yarns of the first embodiment. Using the fibers, a plain weave was manufactured with a design of warp: 10 yarns / inch and weft: 35 yarns / inch. The performance of the woven fabric as a bath towel was very soft, excellent in lightness, and very soft against the skin. The foaming of the soap was also good. Also, the drainage property after use was good, and it was possible to sufficiently dry indoors.

Example 3 The polylactic acid obtained in Example 1 was extruded into the air at an extrusion temperature of 220 ° C., and was 1.5 d (38 mm) by an ordinary production method.
Cut) staples were obtained. A 1/20 yarn is obtained from the fiber and used as one of the five wefts of Example 1. The spun yarn had a strength of 750 g and an elongation of 30%. Using 30d / 1f produced in Example 2 for warp, warp: 10
A cross-oblique woven fabric was manufactured with a design of yarns / inch and weft: 30 yarns / inch. The performance of the woven fabric as a bath towel was very soft, light and bulky, and the friction with the skin was very soft. The foaming of the soap was also good. Also, the drainage property after use was good, and it was possible to sufficiently dry indoors.

Example 4 The polylactic acid staple of Example 3 / about 1.3 d of cotton was mixed at a ratio of 75/25 to obtain a 1/15 yarn. This was used as a weft to obtain a woven fabric having the same structure as in Example 3. The performance of the woven fabric as a bath towel was very soft, excellent in lightness, and very soft against the skin. The foaming of the soap was also good. Also, the drainage property after use was good, and it was possible to sufficiently dry indoors.

Example 4 The polylactic acid of Example 1 was melted at a melting temperature of 225.degree. C. and extruded into the air from 96 pairs of nozzles consisting of 5 small holes having a hole diameter of 0.12 mm. Of 150d / 96f (single yarn 1.56d) having the following. The fiber had physical properties of a strength of 4.5 g / d, an elongation of 35%, and an elastic modulus of 658 Kg / mm ² . The fiber 2
This was also false-twisted with a spindle-type false twisting machine. The false twisted yarn and the 400d / 24f knit / denit yarn of Example 2 are used as wefts at a ratio of 2/8. 30d / 1f of Example 2 is used as a warp. As the warp, a plain woven fabric was manufactured with a design of 10d / inch yarn and a weft: 30 yarn / inch yarn alternately formed of a 300d / 192f processed yarn and a 400d / 24f knit / denit yarn. The performance of the woven fabric as a bath towel was very soft, excellent in lightness, and very soft against the skin. The foaming of the soap was also good. Also, the drainage property after use was good, and it was possible to sufficiently dry indoors.

[0028]

The bath towel made of the polylactic acid fiber of the present invention is excellent in usability, and is decomposed by landfilling even in disposal after use, and finally decomposed into water and carbon dioxide. No excessive heat generation during incineration,
NO _X effects and combustion gas to the incinerator, it is possible to reduce the generation amount of hazardous gases such as SO _X, it can be said that the friendly very environment towel. The characteristics of the bath towels made of polylactic acid fibers are that they are slightly hydrolyzed and become slightly acidic, and can create a skin-friendly condition, and are environmentally and healthily preferred products.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Kajiyama 6-9-106, Kanebocho, Hofu City, Yamaguchi Prefecture (72) Inventor Hideki Hinako 1-1-1-1306 Sumiregaoka, Takarazuka City, Hyogo Prefecture

Claims (3)

[Claims] An optical purity of 90% for each of the warp and the weft.
A bath towel using at least 50% by weight of the above polylactic acid fiber. 2. The polylactic acid fiber used for the warp is 20 to 1
The bath towel according to claim 1, which is a polylactic acid monofilament of 00d. 3. The bath towel according to claim 1, wherein a polylactic acid processed yarn of 75 to 500 d is used as at least a part of the polylactic acid fiber used for the weft.