JPH01314723A - Far-infrared light irradiating polyester fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber suitable for wadding cotton, carpet, inner stuff of underwear or winter cloth, etc., containing a specific amount in total of titanium oxide and silica having individually smaller particle diameters than specific value, containing specific range of ratio of titanium oxide and silica and irradiating far-infrared light. CONSTITUTION:5-15wt.% in total of titanium oxide (TiO2) having <=2mum, preferably <=1mum average particle diameter and silica (SiO2) having <=1mum, preferably 1-100mmum in a ratio of TiO2/SiO2=8/1-1/4, preferably 6/1-5/5 (in weight ratio) are contained in the aimed fiber.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a novel polyester fiber that emits far-infrared rays, and is particularly suitable for use in futons, carpets, inner underwear, winter clothing, etc. It relates to polyester fibers that exhibit heat retention effects.

<Conventional technology> The characteristics of heating an object using far infrared rays are as follows:
It has extremely strong radiation characteristics, and the object to be heated is directly heated and is not hindered even if there is an air layer in between.The difference in heat transfer time between the surface and the inside of the object is small, and the entire object is heated almost simultaneously. It has a high heating effect on polymer compounds and a gentle heating sensation on the human body. Utilizing these characteristics, in addition to industrial use for heating and drying, in addition to heating appliances for consumer use, medical and health applications such as far-infrared saunas and moxibustion devices have been developed.

Although infrared absorbers made of organic compounds are also known as materials for far-infrared radiation sources, metal oxides are cited as one of the most excellent materials. In fact, metal oxides with heat resistance, far-infrared absorption properties, and radiation properties consistent with
Today, it is mass-produced as far-infrared heaters and far-infrared dyes.

The preferred wavelength of far infrared rays that are effective for the human body is said to be 3 to 20 microns (μm), and materials that emit radiation in this wavelength range are preferred.

<Problem to be solved by the invention> Textile products using metal oxides are disclosed in Japanese Patent Application Laid-open No. 1290-1983.
This method is known in Japanese Patent Publication No. 8 and Japanese Patent Application Laid-Open No. 62-238811. The metal oxides used in the former include zircon (ZrO2.5IO2) and titania (TiO2/
The main component is SiO, ), and if necessary, manganese oxide (MnO2), iron oxide (Fe, 03), cobalt oxide (C, O), nickel oxide (Nip), chromium oxide (Cr, 05) Add as appropriate, 1100-17006C
We use fine ceramic powder that has been fired and crushed in
The latter include alumina, magnenoir, norconia, and mullite (
3A1203/2Si02) powder is used. However, the ceramics used in the prior art are not only expensive but also have high hardness, so they have a cost disadvantage in that grinding them to a particle size of 1 μm or less requires considerable cost. Furthermore, conventional far-infrared emitting polyester fibers have had problems with spinnability during spinning.

The present inventors conducted intensive research to improve these drawbacks, and at the same time, they added a specific amount of titanium oxide and silica powder of a specific particle size to the polyester fiber, which emits far infrared rays of 3 to 20 μm, which are most effective for the human body. The inventors have discovered that by doing this, it is possible to obtain polyester fibers that have far-infrared radiation characteristics that are effective for the human body and have good spinning conditions, and have thus arrived at the present invention.

Means for Solving the Problems> That is, the present invention provides titanium oxide (with an average particle size of 2 μm or less)
TiO2) and silica (Si) with an average particle size of 14 m or less
O2) in total from 5 to 15% by weight, and the ratio of titanium oxide and silica is TiO7/SiO,-8/
It is a far-infrared emitting polyester fiber characterized by having a ratio of 1 to 1/4 (weight ratio).

In the present invention, the polyester is not particularly limited, and any polyester that has fiber-forming ability may be used.

Further, the polyester may be produced by either the DMT method or the direct polymerization method, and the polymerization components include, for example, terephthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, sebacic acid, or the like. Carboxylic acid components such as esters can be used, and glycol components include ethylene glycol, 1
．． An aliphatic glycol such as 4-butylene glycol, or a part of the aliphatic glycol can be replaced with diethylene glycol, propylene glycol, polyalkylene glycol, or the like. Furthermore, oxyacids, polyols, etc. can also be appropriately copolymerized. The polyester in the present invention may contain modifiers and functional agents that are applied to ordinary polyester fibers, such as stabilizers and colorants such as dyes and pigments.

The titanium oxide (hereinafter sometimes simply referred to as TiOz) used in the present invention has an average particle size of 2 μm or less, preferably 1 μm or less. If it is larger than 2 μm, it tends to aggregate easily, or problems tend to occur in terms of spinnability. Furthermore, the titanium oxide used in the present invention may be coated with Al2O, Is5if2, P2O5, Fe2e3, or 0, for example.

Furthermore, the silica used in the present invention (hereinafter sometimes simply referred to as SiO2) has an average particle size of 1 μm or less, preferably 1 to 100 millimicrons, in which fine particles exist in the form of single particles. The use of colloidal silica is recommended. This colloidal silica is one in which fine particles containing silicon oxide as a main component exist as a colloid using water, monohydric alcohols, diols, or a mixture thereof as a dispersion medium.

The average particle size in the present invention is the Menuan diameter (particle size corresponding to 50% of the integrated distribution curve), and is determined by the light transmission method, which is determined by measuring the light transmittance of a diluted dispersion of pulverized fine powder. For example, specifically,
Micron Photosizer S K C manufactured by Seishin Enterprises
-200O8.

In the present invention, it is important that the total amount of titanium oxide and silica in the polyester is 5 to 15% by weight.

When the content of these fine powders is less than 5% by weight, the far-infrared radiation effect is slight, but when the content is 5% by weight or more, the warming effect increases. However, if it exceeds 15% by weight, it becomes difficult to form fibers and the physical properties of the fibers deteriorate. The weight ratio of titanium oxide and silica contained is T'i02/5iO2=8
A weight ratio of /1 to 1/4, more preferably 671 to 515, is good. Outside these ranges, the effect in the wavelength range (3 to 20 μm) of guiding infrared rays that is effective for the human body will be reduced. Furthermore, when the TiO2/SiO2/5102 ratio becomes less than 8/1, that is, when the amount of silica is too small, the stringiness tends to deteriorate.

In particular, the present invention is characterized by the combined use of titanium oxide and silica. If any of these is missing, a sufficient far-infrared radiation effect cannot be obtained. This is the wavelength range of 3 to 20, which is the most effective wavelength range for the human body as a whole, as titanium oxide and silica compensate for each other's poor radiation efficiency.
It is assumed that this is to uniformly and efficiently radiate far infrared rays in the μ range.

Furthermore, when polyester containing a considerable amount of inorganic particles is generally melt-spun, it has the serious drawback of poor spinnability due to cut threads, but surprisingly, oxidized silica When used in combination with titanium, an improvement in spinnability was observed compared to when titanium oxide was used alone.

As the method for producing polyester fibers of the present invention, conventionally known methods for blending and/or adhering inorganic particles to polyester fibers can be directly applied. For example, there are (1) a method of dyeing by adding fine powder to a dye solution, (2) a method of adding fine powder to a spinning solution, and (3) a method of adding fine powder to a reaction system during the polymerization process.

Here, in method (1), since the fine powder is attached to the fiber surface, there is no particular problem with spinnability, but the fine powder tends to fall off and the far-infrared radiation performance gradually deteriorates. . Note that "adhesion" is included in "containing" as used in the present invention. In addition, in method (2), fine powder is added after the completion of polycondensation, but since the addition in this case is mixed without a solvent, it becomes huge particles, which may clog the spinneret filter or Easy to cause single thread breakage, etc.

In the present invention, in order to achieve both an excellent far-infrared radiation effect and a good spinning condition, the method (3), that is, the use of titanium oxide and q-silica before the completion of the polycondensation reaction during the production of polyester is used. It is preferable to add the fine powder to the reaction system, and it is particularly preferable to add the fine powder between the esterification and the completion of the polycondensation reaction. In polyester fibers obtained by adding titanium oxide and silica at this stage, these fine powders are uniformly dispersed within the fibers without agglomeration. On the other hand, in the conventional method in which oxide ceramics are kneaded into the melt spinning dope, as mentioned above, the fine powder of oxide ceramics tends to agglomerate into huge particles, so it is difficult to maintain good spinning conditions. However, single yarn breakage or roller winding occurs, which is not very preferable.

Examples of methods for adding titanium oxide and silica include adding these fine powders to a slurry of a dicarboxylic acid component and a diol component in advance and feeding the slurry to an esterification tank; There is a method of directly feeding it to the esterification tank. In the former case, it is preferable that the fine powder is first mixed with the diol component, sufficiently stirred, and then mixed with the dicarboxylic acid component to form a slurry. Note that it is advantageous in terms of handling that titanium oxide and silica are added separately to the diol component.

The polyester fiber produced by this method has fine powder present in the fiber at a high concentration and in a highly dispersed state, and can exhibit a particularly durable far-infrared radiation effect.

In the present invention, the melt spinning itself can be carried out using a conventionally known melt spinning apparatus as is.

The far-infrared emitting polyester fiber of the present invention thus obtained has an excellent heat-retaining effect;
For example, it can be used in futon cotton, carpets, winter clothing, underwear, cushions, etc.

<Examples> Next, the present invention will be explained using Examples, but the present invention is not limited to the following Examples.

Examples 1 to 5, Comparative Examples 1 to 5 Titanium oxide used in Examples and Comparative Examples has a diameter of 08 to 005 μm
It is a commercial product manufactured by Titan Kogyo Co., Ltd. and has a particle size of 0.3 μm (average particle size), and is a titanium oxide for pigments.

The silica is an aqueous silica gel having a particle size distribution in the range of 10 to 20 millimicrons (average particle size 14 mμ) and a concentration of 20% by weight. These titanium oxide and silica are mixed with ethylene glycol at room temperature to a predetermined concentration,
After sufficient stirring, the molar ratio of terephthalic acid to the terephthalic acid was adjusted to 12 and mixed to prepare a slurry. This slurry was continuously supplied to an esterification tank and esterified to obtain an esterified product with an esterification rate of 98%, followed by polymerization to obtain a polyester. Incidentally, Sb, 03 was used as the polymerization catalyst. In accordance with this polymer manufacturing method, the amounts of titanium oxide and silica added were also changed.

Spinning and drawing is performed by a known method to obtain an intrinsic viscosity [η]06
4. A hollow comforter type far-infrared emitting polyester fiber having a fineness of 6 denier and a fiber length of 64 mm was obtained.

Note that the intrinsic viscosity [η] of polyester is determined by using an equal weight mixture of phenol and tetrachloroethane as a solvent at a temperature of 30°C.
This is a value calculated from the solution viscosity measured at °C.

As a method for evaluating the far-infrared radiation effect, the temperature emitted by the sample was measured using an infrared image processing device (trade name: Thermovyure, manufactured by JEOL Ltd.).

A measurement sample and a control sample were placed on a black body heating plate, a camera was placed directly above the sample, and after being left for 20 minutes, the temperature display of each sample on the screen was read. Evaluation was performed based on how much higher the temperature was (temperature difference: ΔT°C) compared to a control sample (fiber containing 20.4% TiO). The various evaluation results are shown in Table 1, and the fiber produced by the manufacturing method of the present invention has good fiber properties, no yarn breakage was observed during spinning, and it has excellent far-infrared radiation characteristics. Ta. On the other hand, in Comparative Examples 1 to 5, the far-infrared radiation characteristics were poor, and in particular, the system containing no silica had poor threadability (Comparative Example 1), and the total amount of TiO2 and 5102 was 1
When it exceeded 5 wt%, the spinning condition was poor (Comparative Example 4).

<Effects of the Invention> According to the present invention, it has become possible to obtain a polyester fiber with extremely good spinning condition, with almost no loss in the physical properties of the resulting fiber, and having excellent far-infrared radiation characteristics.

Margin below

Claims (1)

[Claims] (1) Titanium oxide (TiO_2) with an average particle size of 2 μm or less
) and silica (SiO_2) with an average particle size of 1 μm or less
It contains 5 to 15% by weight in total, and the ratio of titanium oxide and silica is TiO_2/SiO_2 = 8/1 to
A far-infrared emitting polyester fiber characterized by having a weight ratio of 1/4.