JP7513408B2 - cotton - Google Patents

Description

The present invention relates to an environmentally friendly granular cotton that has excellent moisture absorption and heat generation properties, moisture absorption and release properties, and heat retention properties, and is used mainly in clothing and bedding.

2. Description of the Related Art Traditionally, in order to keep the body warm during the cold winter months, cold weather clothing and bedding have been used that have an insulating structure with an air layer between the outside air and the inner clothing or skin, using insulation materials such as down or batting between outer fabrics.
The materials used for this purpose, which have become common, are feathers, cotton, and more recently, granular cotton.
On the other hand, acrylic and cellulose fibers that have moisture absorption and release properties and moisture absorption and heat generation properties have been developed. Attempts have been made to incorporate these fibers into the filling material to achieve warmth and lightness, but simply mixing them together does not provide a dense air layer within the filling material, and so no satisfactory insulation has been achieved.
In recent years, environmental awareness has increased worldwide, and companies are being tasked with issues such as reducing waste plastic and carbon dioxide emissions. These efforts are also heavily influenced by the company's image.

One way to solve these problems is to use natural fiber materials. Typical examples include cotton, hemp, kapok, birch, flax, hemp, potato hemp, wool, alpaca, cashmere, and mohair, but the plant fiber kapok has been attracting a lot of attention in recent years.
In general, kapok, a plant fiber, is a material that is lightweight, water-repellent, and has dense fibers, and so has been used in the fields of materials such as life jackets, bedding such as pillows and stuffed toys, and simply as stuffing for miscellaneous goods.
However, there were several problems with processing the plant fiber kapok in the production of cotton. One of these was that the fibers were easily shed when made into cotton due to their short length. Also, the fibers became worn out after the product was dry-cleaned, so the use of kapok was avoided in terms of providing high-quality cotton.

The following Patent Document 1 describes a method for making large, round fiber granules, but this method has problems such as a hard feel and the material becoming easily worn out.
In addition, the following Patent Document 2 discloses a method of improving the texture and elasticity by incorporating polytrimethylene terephthalate short fibers at a certain mixing ratio or more, but does not boast moisture absorption and heat generation properties or moisture absorption and release properties.
Furthermore, the following Patent Document 3 discloses a composite substrate in which kapok cotton is unevenly mixed and bonded with other materials via a binder to prevent the cotton from falling off. However, this requires a curing process after the binder is applied, which results in a deterioration in texture and poor productivity, and therefore has not been put to practical use.

Patent No. 3990350 JP 2018-178304 A Japanese Patent Application Laid-Open No. 54-88368

In view of the problems with the conventional technology, the problem that this invention aims to solve is to provide an environmentally friendly granular cotton that has the properties of absorbing moisture and generating heat, absorbing and releasing moisture, and retaining heat.

The inventors of the present application conducted extensive research and experiments to solve this problem, and as a result, unexpectedly discovered that by taking advantage of the characteristics of the plant fiber kapok, which is light, dense, and a highly hollow natural fiber with a hollow ratio of approximately 80%, and by using this plant fiber kapok as the main ingredient in order to express the heat retention and insulation properties, and by using animal fibers such as wool, alpaca, and cashmere, cellulose fibers, and synthetic fibers in the appropriate mixture ratios to make batting, it is possible to obtain the original properties required for batting (moisture absorption and heat generation, moisture absorption and release, and heat retention), which led to the completion of the present invention.

That is, the present invention is as follows.
[1] A batting comprising a mixture of 20 wt% to 60 wt% hygroscopic fiber and 80 wt% to 40 wt% hydrophobic fiber, the hygroscopic fiber being at least one selected from the group consisting of kapok vegetable fiber, animal fiber, and cellulose fiber, the mixture ratio of the kapok vegetable fiber being 0.1 wt% to 40 wt%, the hydrophobic fiber being a synthetic fiber, and the granular batting having an approximately spherical shape and exhibiting a circular or elliptical appearance with a diameter of 0.5 to 30 mm.
[2] The cotton wool described in [1] above, having a moisture absorption and heat generation value of 3°C to 8°C, moisture absorption and release rate of 3% to 15%, and heat retention of 60% to 85%.
[3] The cotton batting according to [1] or [2], wherein the single fiber fineness of the plant fiber kapok is 0.15 dtex or more and 0.30 dtex or less.
[4] The cotton according to any one of [1] to [3], wherein the synthetic fiber has a single fiber fineness of 1.0 dtex or more and 10 dtex or less.
[5] The cotton batting according to any of [1] to [4], wherein the animal fiber content is 0.1 wt% or more and 40 wt% or less, and the single fiber diameter is 10 μm or more and 25 μm or less.
[6] The cotton according to any one of [1] to [5], wherein the blend ratio of the cellulose fibers is 0.1 wt% or more and 40 wt% or less, and the single fiber fineness is 1.0 dtex or more and 10 dtex or less.

The cotton of the present invention is an environmentally friendly granular cotton that has excellent moisture absorption and heat generation, moisture absorption and release, and heat retention properties, which are inherent characteristics of cotton, by blending the plant fiber kapok as a hygroscopic fiber and synthetic fibers as a hydrophobic fiber in an appropriate and balanced ratio, and can be used, for example, for cold weather clothing, bedding such as futons and cushions, sports and outdoor goods, etc.

FIG. 1 is a photograph of the appearance of the cotton of this embodiment. FIG. 2 is a schematic diagram of the filling of this embodiment.

Hereinafter, an embodiment of the present invention will be described in detail.
The cotton of this embodiment is a cotton comprising a mixture of 20 wt% to 60 wt% hygroscopic fibers and 80 wt% to 40 wt% hydrophobic fibers, the hygroscopic fibers being at least one type selected from the group consisting of kapok plant fibers, animal fibers, and cellulose fibers, the mixture ratio of the kapok plant fibers being 0.1 wt% to 40 wt%, the hydrophobic fibers being synthetic fibers, and the granular cotton is a cotton having an approximately spherical shape characterized by having a circular or elliptical appearance with a diameter of 0.5 mm to 30 mm.

The cotton of this embodiment preferably has a moisture absorption and heat generation value of 3°C to 8°C, a moisture absorption and release rate of 3% to 15%, and a heat retention rate of 60% to 85%.
The single fiber fineness of the kapok plant fiber is preferably 0.15 dtex or more and 0.30 dtex or less.
The single fiber fineness of the synthetic fiber is preferably 1.0 dtex or more and 10 dtex or less.
It is preferable that the mixing ratio of the animal fibers is 0.1 wt % or more and 40 wt % or less, and the single fiber diameter is 10 μm or more and 25 μm or less.
It is preferable that the blending ratio of the cellulose fibers is 0.1 wt % or more and 40 wt % or less, and the single fiber fineness is 1.0 dtex or more and 10 dtex or less.

The cotton of this embodiment is made of a mixture of hygroscopic fibers and hydrophobic fibers, and at least a portion of the hygroscopic fibers contains the vegetable fiber kapok (hereinafter also referred to as kapok fiber).
In this specification, the term "hygroscopic fiber" refers to fibers having an official moisture regain of 6% or more, such as natural plant fiber kapok, animal fiber, cellulose fiber, and the like.
Kapok is a tree of the Bombacaceae family that grows widely, mainly in Southeast Asia, and is widely cultivated for the fiber (fluff) extracted from its seeds. Kapok is a natural plant fiber with a fiber length of about 2 to 7 mm, which places a small burden on the environment. It is extremely light and dense, and has a highly hollow structure with a hollow ratio of about 80%.

The batting of this embodiment is characterized by containing hygroscopic fibers, plant fiber kapok, animal fiber, and cellulose fiber, in a total mixture ratio of 20 wt% to 60 wt%. If the total mixture ratio is less than 20 wt%, the hygroscopic heat generation, hygroscopic release, and/or heat retention required for the batting are impaired. On the other hand, if the total mixture ratio exceeds 60 wt%, the mixture ratio of hydrophobic synthetic fibers, such as polyester fibers, decreases, so that bulkiness and washing durability decrease significantly, the batting shape is not maintained, and marketability is lost. The total mixture ratio of hygroscopic fibers, plant fiber kapok, animal fiber, and cellulose fiber, is preferably 25 wt% to 50 wt%.

The filling of this embodiment must contain kapok fiber at a mixing ratio of 0.1 wt% to 40 wt%. If the mixing ratio of kapok fiber exceeds 40 wt%, the kapok fiber will fall off more in the filling product, causing the kapok fiber to fly off during sewing, which can worsen the working environment, and the falling off of the kapok fiber when wearing or washing the clothing product can reduce the functionality of the filling and deteriorate the appearance of the surface of the clothing to which the filling is sewn. On the other hand, if the mixing ratio is less than 0.1 wt%, the desired effect will not be achieved. The mixing ratio of kapok fiber is preferably 1.0 wt% to 35 wt%, and more preferably 10 wt% to 30 wt%.

The cotton of this embodiment may contain animal fibers as hygroscopic fibers in a blend ratio of 40 wt% or less in addition to kapok fibers. Examples of animal fibers include wool, angora, and cashmere. Kapok fibers and cellulose fibers are considered difficult to process because they do not shrink much and do not easily entangle with each other, but animal fibers have the ability to shrink and therefore tend to entangle, making the fibers bulky and elastic, which also has an effect on sagging resistance. The blend ratio of animal fibers is preferably 0.1 wt% or more, and more preferably 1.0 wt% to 30 wt%.

In the present embodiment, the batting may contain cellulose fiber as a moisture-absorbing fiber in a blend ratio of 40 wt% or less in addition to kapok fiber. Examples of cellulose fiber include natural fibers such as cotton and hemp, and regenerated cellulose fibers such as cupra ammonium rayon, viscose rayon, and solvent-spun cellulose fiber. It is more preferable that the blend ratio of cellulose fiber is 0.1 wt% or more, and particularly preferably 1.0 wt% or more and 30 wt% or less.

The filling of this embodiment contains 40wt% to 80wt% synthetic fibers, which are hydrophobic fibers. If the blending ratio is within this range, it is possible to impart properties such as strength as filling without reducing the effect of the hygroscopic fibers, and it is possible to achieve excellent bulkiness and washing durability, particularly by suppressing sagging and uneven filling after dry cleaning, and to maintain the required filling shape. Examples of synthetic fibers include polyester fibers and polyamide fibers (nylon), but plant-derived polylactic acid fibers are preferable as they can be advertised as eco-friendly products.

The diameter of the cotton in this embodiment is the sum (D+L1+L2) of the diameter D (mm) of the granular cotton part at the center of the granular cotton fluff part, the length _L1 (mm) of the fluff part protruding from one side, and the length _L2 (mm) of the fluff part protruding from the other side of the granular cotton part, as shown in Figure _2. These can be easily measured using a magnifying microscope, and for example, _in the following examples, measurements were made using a digital microscope VHX-2000 manufactured by KEYENCE.

The cotton of this embodiment has a fluff part protruding from the surface of the granular cotton, and when the diameter of the granular cotton part at the center of the fluff part of the granular cotton is D (mm) and the length of the fluff part protruding from one side is _L1 (mm), if the ratio of the length _L1 of the fluff part to the diameter D of the particle is in the range of 0.2≦ _L1 /D≦3, the fluff parts will be entangled with each other to maintain the expansion of the cotton, reduce bias, and improve heat retention. The same applies to _L2 , and when _L1 and _L2 are collectively written as L, it is preferably in the range of 0.2≦L/D≦3, and more preferably 0.5≦L/D≦2.

The cotton of this embodiment is characterized by being granular and having a roughly spherical shape with a circular or elliptical appearance having a diameter of 0.5 mm to 30 mm. In this specification, the term "granular cotton" refers to cotton that is produced into a ball shape by a granular cotton production machine after the fibers are opened and mixed.
If the diameter of the batting of this embodiment is less than 0.5 mm, the batting particles will be dense when filled with granular batting, making the product heavy and lacking in volume, while if the diameter exceeds 30 mm, the filling rate will not be sufficient, and aesthetics and functionality will be impaired. The diameter of the batting of this embodiment is preferably 5 mm or more and 15 mm or less.

In order to satisfy the performance of the filling in this embodiment, it is preferable that each fiber constituting the filling has the following shape.
The kapok fiber preferably has a fiber length of 7 mm to 15 mm and a single fiber fineness of 0.15 dtex or more and 0.30 dtex or less.
Since animal fibers are natural fibers, they have an irregular shape, but it is preferable that the fiber length is 30 mm to 100 mm and the single fiber diameter is 10 μm or more and 25 μm or less.
The cellulose fibers preferably have a fiber length of 36 mm to 51 mm and a single fiber fineness of 1.0 dtex or more and 10 dtex or less.
The synthetic fibers preferably have a fiber length of 30 mm to 60 mm and a single fiber fineness of 1.0 dtex or more and 10 dtex or less.

The cotton of this embodiment can exhibit excellent performance, with a moisture absorption and heat generation value of 3°C to 8°C, moisture absorption and release rate of 3 to 15%, and heat retention of 60% to 85%, as measured by the method described below.

The present invention will be specifically described below with reference to examples and comparative examples.
In the following examples, specific material names and numerical values are given, but it goes without saying that the present invention is not limited to these.
The official moisture regain of each fiber was determined by the measurement method described in JIS 0105, General Rules for Physical Testing Methods for Textile Products.
The diameters of the fibers were measured using the KEYENCE VHX-2000 digital microscope, D, _L1 , and _L2 . Six particles were selected from the sample and measured twice in the horizontal and vertical directions in each microscope field, and the average of 12 measurements was calculated. L/D was calculated by averaging 24 measurements, including _L1 /D and _L2 /D in each measurement.

Example 1
Natural plant fiber kapok (fineness 0.15 dtex to 0.30 dtex, fiber length 9 mm to 15 mm, official moisture regain 6% or more), animal fiber cashmere (fiber length 25 mm to 90 mm, single fiber diameter 12 μm to 20 μm, official moisture regain 15%), and polyester fiber (fineness 3.3 dtex, fiber length 51 mm, official moisture regain 0.4%) were opened and blended in a ratio of 20:10:70, and then formed into balls in a granular cotton forming machine to obtain cotton formed into an approximately spherical shape having a circular or elliptical appearance with a diameter of 9.5 mm and an L/D ratio of 0.8.

Example 2
The fibers were opened and mixed in the same manner as in Example 1, except that the plant fiber kapok, cellulose fiber (fineness 1.4 dtex, fiber length 51 mm, official moisture regain 11%), and polyester fiber were contained in a ratio of 20:30:50.The fibers were then formed into balls in a granular cotton making machine, and cotton formed into an approximately spherical shape with a circular or elliptical appearance and a diameter of 9.8 mm and an L/D ratio of 0.7 was obtained.

Example 3
The fibers were opened and mixed in the same manner as in Example 1, except that the vegetable fiber kapok and polyester fiber were contained in a ratio of 30:70, and then the fibers were formed into balls using a granular cotton making machine, obtaining cotton formed into an approximately spherical shape with a circular or elliptical appearance and a diameter of 10.0 mm and an L/D ratio of 1.0.

(Comparative Example 1)
Polyester fibers (fineness 3.3 dtex, fiber length 51 mm, nominal moisture regain 0.4%) were opened and blended, then formed into balls using a pellet-forming machine, resulting in approximately spherical batting with a circular or elliptical appearance and a diameter of 13.8 mm and an L/D ratio of 0.5.

The moisture absorption and heat generation properties, moisture absorption and release properties, and heat retention properties of the batting of the examples and comparative examples prepared as described above were measured and evaluated as follows. The evaluation results are shown in Table 1 below.

(1) Moisture absorption heat value (℃)
A 5g sample of cotton was left in a constant temperature dryer at 105°C for 1 hour, then left in an environment of 20°C temperature and 5% RH for 6 hours in what is commonly referred to as an environmental test chamber, and then left in an environment of 20°C temperature and 65% RH for 5 minutes.The peak value of the change in surface temperature of the cotton was measured using infrared thermography, and the temperature rise (°C) due to the high humidity environment was calculated.

(2) Moisture absorption and release (%)
A 5g sample of cotton was left in a constant temperature dryer at 105°C for 2 hours to dry it out, and then based on the weight of the cotton, it was left in an initial environment of 30°C temperature and 95% RH for 5 hours, and then left in an environment of 30°C temperature and 30% RH for 5 hours.The change in weight of the cotton was measured over time, and the difference between the maximum moisture content in the initial environment where moisture was absorbed, calculated from the bone dry weight of the cotton, and the minimum moisture content released in the subsequent environment was calculated.

(3) Heat retention (%) and clo value These were measured in accordance with JIS L 1096 Method A (constant temperature method) with an outside air temperature of 23.0°C and a heating element surface temperature of 36.0°C.

The cotton of the present invention is an environmentally friendly granular cotton that has high functionality such as moisture absorption and heat generation, moisture absorption and release, and heat retention, by blending the natural fiber kapok, animal fiber, cellulose fiber, and synthetic fiber in an appropriate and balanced ratio, and is therefore suitable for use in, for example, cold weather clothing.

Claims (6)

The batting is a mixture of 20wt%-60wt% hygroscopic fibers and 80wt%-40wt% hydrophobic fibers, the hygroscopic fibers being at least one selected from the group consisting of kapok vegetable fiber, animal fibers, and cellulose fibers other than kapok vegetable fiber, the kapok vegetable fiber mixing ratio being 0.1wt%-40wt%, the hydrophobic fibers being synthetic fibers selected from the group consisting of polyester fibers, polyamide fibers (nylon), and polylactic acid fibers, and the batting has a substantially spherical shape and is characterized by having a circular or elliptical appearance with a diameter of 0.5mm-30mm. The cotton wool according to claim 1, which has a moisture absorption heat generation value of 3°C to 8°C, moisture absorption and release rate of 3% to 15%, and heat retention of 60% to 85%. The wadding according to claim 1 or 2, wherein the single fiber fineness of the kapok vegetable fiber is 0.15 dtex or more and 0.30 dtex or less. The wadding according to any one of claims 1 to 3, wherein the synthetic fiber has a single fiber fineness of 1.0 dtex or more and 10 dtex or less. The batting according to any one of claims 1 to 4, in which the animal fiber content is 0.1 wt% or more and 40 wt% or less, and the single fiber diameter is 10 μm or more and 25 μm or less. The wadding according to any one of claims 1 to 5, in which the blending ratio of cellulose fibers other than the kapok vegetable fiber is 0.1 wt% or more and 40 wt% or less, and the single fiber fineness is 1.0 dtex or more and 10 dtex or less.

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