JP7363394B2 - Infrared absorbing fibers and textile products - Google Patents

Description

The present invention relates to infrared absorbing fibers and textile products.

A variety of cold-weather clothing, interior goods, and leisure goods with enhanced heat retention effects have been devised and put into practical use. There are two main methods of increasing the heat retention effect that have been put to practical use so far.

The first method is to maintain heat retention by reducing the dissipation of heat generated from the human body. Specifically, for example, methods have been adopted to physically increase the air layer in cold-weather clothing by controlling the weaving and knitting structure, or by making the fibers used hollow or porous. .

The second method is to store heat through active methods such as radiating the heat generated by the human body back into the human body or converting some of the sunlight received by winter clothing into heat. This is a way to improve Specifically, for example, in cold weather clothing, a method has been adopted in which the entire clothing or the fibers constituting the cold weather clothing are subjected to chemical and physical processing.

As mentioned above, the first method has been to increase the air space in clothing, make the fabric thicker, make the mesh finer, or make the color darker. A specific example is a type of clothing that is often used in winter, such as sweaters, or clothing for winter sports, where a padding is inserted between the outer material and the lining, and the thickness of the air layer in the padding maintains heat retention. Examples include clothing made with However, increasing the air layer by adding padding or other means makes the clothing heavy and bulky, which causes problems when used in sports that require ease of movement. In order to eliminate such problems, in recent years, the second method described above, which actively utilizes internally generated heat or heat from the outside, has begun to be adopted.

One way to implement the second method is to deposit metals such as aluminum or titanium on the lining of clothing, and actively dissipate heat by reflecting the radiant heat emitted from the body on the metal-deposited surface. There are known ways to prevent this. However, with this method, not only does it cost a lot to vapor-deposit metal onto clothing, but the yield is also poor due to uneven vapor deposition, which results in an increase in the price of the product itself.

Another method for implementing the second method is to knead ceramic particles such as alumina, zirconia, and magnesia into the fiber itself, and use the far-infrared radiation effect of these ceramic particles and convert light into heat. A method has been proposed that utilizes the changing effect, that is, a method that actively incorporates external energy.

For example, Patent Document 1 discloses one or more kinds of inorganic fine particles having heat radiation properties and containing at least one kind of metal or metal ion having a thermal conductivity of 0.3 kcal/ ^m2 ·sec·°C or more. A heat ray emissive fiber characterized by containing the following is disclosed. Silica or barium sulfate is mentioned as inorganic fine particles having heat radiation properties.

Patent Document 2 describes a thermoplastic polymer A having a melting point of 110°C or higher, and a thermoplastic polymer B having a melting point of 15 to 50°C, a cooling crystallization temperature of 40°C or lower, and a heat of crystallization of 10 mJ/mg or higher. A composite fiber comprising 0.1 to 20% by weight of ceramic fine particles having far-infrared radiation ability based on the weight of the fiber, and characterized in that the fiber surface is covered with polymer A. A heat-retaining composite fiber is disclosed.

Patent Document 3 discloses an infrared absorbing processed textile product in which a binder resin containing an infrared absorbing agent made of at least one type of predetermined amino compound is dispersed and fixed to the textile product.

Patent Document 4 discloses that the spectral reflection of fabric in the range of 750 to 1,500 nm as near-infrared absorption is achieved by dyeing with a dye that has a property of absorbing in the near-infrared region larger than that of black dye in combination with other dyes. A method for near-infrared absorption processing of a cellulose-based fibrous structure in which the near-infrared absorption ratio is 65% or less is disclosed.

Furthermore, in Patent Documents 5, 6, and 7, the applicant of the present invention has disclosed fibers containing boride fine particles, tungsten oxide fine particles, and composite tungsten oxide fine particles, and textile products obtained by processing the fibers. is proposed.

Japanese Patent Application Publication No. 11-279830 Japanese Patent Application Publication No. 5-239716 Japanese Patent Application Publication No. 8-3870 Japanese Patent Application Publication No. 9-291463 Japanese Patent Application Publication No. 2005-9024 Japanese Patent Application Publication No. 2006-132042 International Publication No. 2019/054476

For example, as disclosed in Patent Documents 5 to 7, infrared absorbing fibers containing infrared absorbing particles have been studied. However, according to studies conducted by the inventors of the present invention, infrared absorbing particles such as tungsten oxide fine particles do not have sufficient chemical resistance, and infrared absorbing fibers and textile products cannot be exposed to high-temperature acidic or alkaline chemical environments. Infrared absorption properties may deteriorate when exposed to.

One aspect of the present invention aims to provide an infrared absorbing fiber with chemical resistance properties.

In one aspect of the invention, a fiber;
organic-inorganic hybrid infrared absorbing particles;
Each of the organic-inorganic hybrid infrared absorbing particles has an infrared absorbing particle and a coating resin that includes the infrared absorbing particle,
The organic-inorganic hybrid infrared-absorbing particles provide an infrared-absorbing fiber arranged in one or more portions selected from the interior and surface of the fiber.

In one aspect of the present invention, an infrared absorbing fiber with chemical resistance properties can be provided.

A schematic diagram of the crystal structure of a hexagonal composite tungsten oxide. 1 is a transmission electron micrograph of organic-inorganic hybrid infrared particles obtained in Example 1.

[Infrared absorbing fiber]
In this embodiment, an example of the structure of the infrared absorbing fiber will be described.

The infrared absorbing fiber of this embodiment can include fiber and organic-inorganic hybrid infrared absorbing particles.
The organic-inorganic hybrid infrared absorbing particles can include infrared absorbing particles and a coating resin that covers at least a portion of the surface of the infrared absorbing particles.
In addition, the organic-inorganic hybrid infrared absorbing particles can be arranged at one or more selected portions inside and on the surface of the fiber.

As mentioned above, infrared absorbing particles used in infrared absorbing fibers sometimes did not have sufficient chemical resistance. Therefore, the inventors of the present invention conducted extensive studies on a method for producing infrared absorbing particles with chemical resistance. As a result, it was found that chemical resistance can be exhibited by directly arranging an organic material such as a resin on at least a portion of the surface of the infrared absorbing particles to form organic-inorganic hybrid infrared absorbing particles.

However, infrared absorbing particles are usually made of an inorganic material, and it has been difficult to arrange an organic material such as a resin on at least a portion of their surfaces. For this reason, organic-inorganic hybrid infrared absorbing particles and methods for producing them have not been known. Therefore, the inventors of the present invention conducted further studies and discovered organic-inorganic hybrid infrared absorbing particles in which an organic material is arranged on the surface of infrared absorbing particles, and a method for producing the same.

Then, the inventors discovered that by using such organic-inorganic hybrid infrared absorbing particles, an infrared absorbing fiber having chemical resistance can be obtained, and the present invention was completed.

First, a method for producing organic-inorganic hybrid infrared absorbing particles and organic-inorganic hybrid infrared absorbing particles will be described.
1. Method for producing organic-inorganic hybrid infrared absorbing particles The infrared absorbing fiber of this embodiment can contain organic-inorganic hybrid infrared absorbing particles as described above. The method for producing organic-inorganic hybrid infrared absorbing particles can include, for example, the following steps.

A dispersion liquid preparation step of preparing a dispersion liquid containing infrared absorbing particles, a dispersant, and a dispersion medium.
A dispersion medium reduction step in which the dispersion medium is evaporated from the dispersion liquid.
A raw material mixed liquid preparation step of preparing a raw material mixed liquid by mixing the infrared absorbing particles recovered after the dispersion medium reduction step, a coating resin raw material, an organic solvent, an emulsifier, water, and a polymerization initiator.
A stirring process in which the raw material mixture is stirred while being cooled.
A polymerization process in which a polymerization reaction of the resin raw material for coating is performed after deoxidizing treatment to reduce the amount of oxygen in the raw material mixture.

Each step will be explained below.
(1) Dispersion preparation step In the dispersion preparation step, a dispersion containing infrared absorbing particles, a dispersant, and a dispersion medium can be prepared.

Each material that can be suitably used when preparing a dispersion liquid in the dispersion liquid preparation step will be explained.
(a) Infrared Absorbing Particles In the dispersion liquid preparation step, various infrared absorbing particles that are required to have improved chemical resistance, such as acid resistance or alkali resistance, can be used as the infrared absorbing particles. As the infrared absorbing particles, for example, infrared absorbing particles containing various materials containing free electrons are preferably used, and infrared absorbing particles containing various inorganic materials containing free electrons can be more preferably used.

As the infrared absorbing particles, infrared absorbing particles containing one or more types selected from tungsten oxides having oxygen vacancies and composite tungsten oxides can be particularly preferably used. When a tungsten oxide having oxygen vacancies or a composite tungsten oxide is used as the infrared absorbing particles, the organic-inorganic hybrid infrared absorbing particles containing the infrared absorbing particles can be made light in color and inconspicuous. In this case, specifically, the infrared absorbing particles are, for example, tungsten oxide represented by the general formula W _y O _z (W: tungsten, O: oxygen, 2.2≦z/y≦2.999), and General formula M _x W _y O _z (Element M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt , Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo , Ta, Re, Be, Hf, Os, Bi, I, expressed as 0.001≦x/y≦1, 2.0≦z/y≦3.0) It is preferable to contain one or more types selected from composite tungsten oxides.

In general, it is known that materials containing free electrons exhibit a reflection/absorption response to electromagnetic waves around the solar radiation region with a wavelength of 200 nm to 2600 nm due to plasma vibration. Therefore, various materials containing free electrons can be suitably used as infrared absorbing particles. Infrared absorbing particles are preferable because, for example, when particles are smaller than the wavelength of light, geometric scattering in the visible light region (wavelengths from 380 nm to 780 nm) can be reduced and particularly high transparency can be obtained in the visible light region. .

In this specification, "transparency" is used to mean "less scattering and high transparency for light in the visible light region."

Generally, tungsten oxide (WO ₃ ) does not have effective free electrons, so it has poor absorption/reflection properties in the infrared region and is not effective as an infrared absorbing particle.

On the other hand, it is known that WO ₃ having oxygen vacancies and a composite tungsten oxide obtained by adding a positive element such as Na to WO ₃ are conductive materials and materials having free electrons. Analysis of single crystals of materials with these free electrons suggests that the free electrons respond to light in the infrared region.

According to studies by the inventors of the present invention, there is a specific range of the composition range of tungsten and oxygen that is particularly effective as an infrared absorbing material, and is transparent in the visible light region and particularly effective in the infrared region. Tungsten oxide and composite tungsten oxide with strong absorption can be used.

Therefore, tungsten oxide and composite tungsten oxide, which are a type of material for infrared absorbing particles that can be suitably used in the dispersion liquid preparation process, will be further explained below.
(a1) Tungsten oxide Tungsten oxide is expressed by the general formula W _y O _z (where W is tungsten, O is oxygen, and 2.2≦z/y≦2.999).

In the tungsten oxide represented by the general formula W _y O _z , the composition range of tungsten and oxygen is preferably such that the composition ratio (z/y) of oxygen to tungsten is less than 3, and 2.2≦z It is more preferable that /y≦2.999. In particular, it is more preferable that 2.45≦z/y≦2.999.

If the value of z/y is 2.2 or more, it is possible to avoid the appearance of an unintended WO ₂ crystal phase in the tungsten oxide, and to obtain chemical stability as a material. This makes them particularly effective infrared absorbing particles.

In addition, by setting the value of z/y to preferably less than 3, more preferably 2.999 or less, a sufficient amount of free electrons is generated in order to improve the absorption and reflection characteristics in the infrared region, resulting in an efficient method. It can be an infrared absorbing particle.

In addition, the so-called "Magneli phase", which has a composition ratio expressed as 2.45≦z/y≦2.999, is chemically stable and has excellent light absorption properties in the near-infrared region, so it is highly effective in absorbing infrared rays. It can be more preferably used as a material. Therefore, it is more preferable that the above z/y satisfies 2.45≦z/y≦2.999 as described above.
(a2) Composite tungsten oxide Composite tungsten oxide is obtained by adding element M, which will be described later, to the above-mentioned WO ₃ .

By adding element M to form a composite tungsten oxide, free electrons are generated in WO ₃ , and strong absorption characteristics derived from free electrons are developed especially in the near-infrared region, absorbing near-infrared light with a wavelength of around 1000 nm. It is effective as a particle that

That is, by forming a composite tungsten oxide by controlling the amount of oxygen and adding element M that generates free electrons to the WO ₃ , more efficient infrared absorption characteristics can be exhibited. When the general formula of a composite tungsten oxide that combines the control of the amount of oxygen with respect to WO ₃ and the addition of the element M that generates free electrons is written as M _x W _y O _z , 0.001≦x/y It is preferable to satisfy the following relationships: ≦1, 2.0≦z/y≦3.0. In the above general formula, M represents the element M described above, W represents tungsten, and O represents oxygen.

As described above, when the value of x/y indicating the amount of addition of element M is 0.001 or more, a particularly sufficient amount of free electrons is generated in the composite tungsten oxide, and a high infrared absorption effect can be obtained. As the amount of element M added increases, the amount of free electrons supplied increases and the infrared absorption efficiency also increases, but this effect is saturated when the value of x/y is about 1. Further, it is preferable that the value of x/y is 1 or less because it is possible to avoid generation of an impurity phase in the infrared absorbing particles containing the composite tungsten oxide.

In addition, element M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au. , Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be , Hf, Os, Bi, and I.

From the viewpoint of particularly increasing the stability in M _x W _y O _z , the element M is an alkali metal, an alkaline earth metal, a rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, More preferably, it is one or more elements selected from V, Mo, Ta, and Re. From the viewpoint of improving the optical properties and weather resistance of the infrared absorbing particles containing the composite tungsten oxide, element M is selected from alkali metals, alkaline earth metal elements, transition metal elements, group 4B elements, and group 5B elements. More preferably, it is one or more selected elements.

Regarding the value of z/y indicating the amount of oxygen added, the same mechanism works in the composite tungsten oxide expressed as M _x W _y O _z as in the above-mentioned tungsten oxide expressed as W _y O _z . In addition, even when z/y=3.0, free electrons are supplied due to the addition amount of the element M mentioned above. Therefore, 2.0≦z/y≦3.0 is preferable, 2.2≦z/y≦3.0 is more preferable, and 2.45≦z/y≦3.0 is even more preferable.

Furthermore, when the composite tungsten oxide has a hexagonal crystal structure, the transmission of light in the visible region of the infrared absorbing particles containing the composite tungsten oxide is improved, and the absorption of light in the infrared region is improved. This will be explained with reference to FIG. 1, which is a schematic plan view of this hexagonal crystal structure.

FIG. 1 shows a projected view of the crystal structure of a composite tungsten oxide having a hexagonal crystal structure when viewed from the (001) direction, and a unit cell 10 is indicated by a dotted line.

In FIG. 1, six octahedrons 11 formed by _six units of WO are assembled to form a hexagonal void 12, and an element 121, which is element M, is arranged in the void 12 to form one unit. A large number of this single unit aggregate to form a hexagonal crystal structure.

In order to improve the transmission of light in the visible light region and the absorption of light in the infrared region, it is sufficient that the composite tungsten oxide contains the unit structure explained using FIG. , it does not matter whether the composite tungsten oxide is crystalline or amorphous.

When cations of element M are added and present in the hexagonal voids described above, the transmission of light in the visible light region is improved and the absorption of light in the infrared region is improved. Generally, when an element M having a large ionic radius is added, the hexagonal crystal is likely to be formed. Specifically, when one or more elements selected from Cs, K, Rb, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn are added as the element M, hexagonal crystals are likely to be formed. Of course, elements other than these may be used as long as the above-mentioned element M is present in the hexagonal void formed by WO ₆ units, and the element is not limited to the above-mentioned elements.

Since the composite tungsten oxide having a hexagonal crystal structure has a uniform crystal structure, the amount of element M added is preferably 0.2 or more and 0.5 or less in terms of the value of x/y in the general formula described above. 0.33 is more preferred. Since the value of x/y is 0.33, it is considered that the above-mentioned element M is arranged in all the hexagonal voids.

Furthermore, infrared absorbing particles containing composite tungsten oxides other than hexagonal, such as tetragonal or cubic, also have sufficiently effective infrared absorption characteristics. The absorption position in the infrared region tends to change depending on the crystal structure, and the absorption position tends to shift toward longer wavelengths in the order of cubic < tetragonal < hexagonal. In addition, the hexagonal crystal, tetragonal crystal, and cubic crystal have the lowest absorption of light in the visible light region. Therefore, it is preferable to use a hexagonal composite tungsten oxide for applications that transmit more light in the visible region and block more light in the infrared region. However, the trends in the optical properties described here are just general trends and vary depending on the type of additive element, the amount added, and the amount of oxygen, and the present invention is not limited thereto.

Infrared absorbing particles containing tungsten oxide or composite tungsten oxide largely absorb light in the near-infrared region, particularly around a wavelength of 1000 nm, so the transmitted color tone thereof often ranges from blue to green.

Further, the dispersed particle diameter of the infrared absorbing particles can be selected depending on the purpose of use.

First, when used in applications where transparency is desired to be maintained, it is preferable that the infrared absorbing particles have a dispersed particle diameter of 800 nm or less. This is because particles with a dispersed particle diameter of 800 nm or less do not completely block light due to scattering, and can maintain visibility in the visible light region and at the same time efficiently maintain transparency. In particular, when emphasis is placed on transparency in the visible light region, it is preferable to further consider reducing scattering by particles.

When reducing scattering by particles is important, the dispersed particle diameter is preferably 200 nm or less, more preferably 100 nm or less. This is because if the dispersed particle size of the particles is small, the scattering of light in the visible light range of wavelengths from 400 nm to 780 nm due to geometric scattering or Mie scattering is reduced. This is because it is possible to avoid the appearance of cloudy glass and the inability to obtain clear transparency. That is, when the dispersed particle diameter becomes 200 nm or less, the above-mentioned geometric scattering or Mie scattering decreases and becomes a Rayleigh scattering region. This is because in the Rayleigh scattering region, scattered light is reduced in proportion to the sixth power of the particle diameter, so as the dispersed particle diameter decreases, scattering decreases and transparency improves.

Further, it is preferable that the dispersed particle diameter is 100 nm or less, since the amount of scattered light will be very small. From the viewpoint of avoiding light scattering, it is preferable that the dispersed particle size is smaller.

Although the lower limit of the dispersed particle size of the infrared absorbing particles is not particularly limited, it is preferable that the dispersed particle size is 1 nm or more, for example, because it can be easily produced industrially.

By setting the dispersed particle size of the infrared absorbing particles to 800 nm or less, the haze value of the infrared absorbing particle dispersion in which the infrared absorbing particles are dispersed in a medium is 30% or less with a visible light transmittance of 85% or less. be able to. By controlling the haze to 30% or less, the infrared absorbing particle dispersion can be prevented from becoming like cloudy glass, and particularly clear transparency can be obtained.

The dispersed particle diameter of the infrared absorbing particles can be measured using ELS-8000 manufactured by Otsuka Electronics Co., Ltd., which is based on the principle of dynamic light scattering.

Further, from the viewpoint of exhibiting excellent infrared absorption characteristics, the crystallite diameter of the infrared absorbing particles is preferably 1 nm or more and 200 nm or less, more preferably 1 nm or more and 100 nm or less, and preferably 10 nm or more and 70 nm or less. More preferred. To measure the crystallite diameter, measurement of an X-ray diffraction pattern by powder X-ray diffraction method (θ-2θ method) and analysis by Rietveld method can be used. The X-ray diffraction pattern can be measured using, for example, a powder X-ray diffractometer "X'Pert-PRO/MPD" manufactured by PANalytical, Inc., Spectris Co., Ltd.
(b) Dispersant The dispersant is used for the purpose of hydrophobizing the surface of the infrared absorbing particles. The dispersant can be selected depending on the dispersion system, which is a combination of infrared absorbing particles, dispersion medium, coating resin raw material, and the like. Among these, dispersants having one or more functional groups selected from amino groups, hydroxyl groups, carboxyl groups, sulfo groups, phosphor groups, and epoxy groups can be preferably used. When the infrared absorbing particles are tungsten oxide or composite tungsten oxide, the dispersant more preferably has an amino group as a functional group.

As described above, the dispersant preferably has an amino group as a functional group, that is, is an amine compound. Moreover, it is more preferable that the amine compound is a tertiary amine.

Further, since the dispersant is used for the purpose of hydrophobizing the surface of the infrared absorbing particles, it is preferably a polymeric material. For this reason, the dispersant preferably has one or more types selected from, for example, long-chain alkyl groups and benzene rings, and has styrene and methacrylic acid, which is a tertiary amine, in the side chain, which can also be used as a coating resin raw material. A polymer dispersant having a copolymer of (dimethylamino)ethyl or the like can be more preferably used. The long chain alkyl group preferably has 8 or more carbon atoms. Note that, for example, a dispersant that is a polymeric material and an amine compound can also be used.

The amount of the dispersant added is not particularly limited and can be selected arbitrarily. A suitable amount of the dispersant to be added can be selected depending on the type of the dispersant and the infrared absorbing particles, the specific surface area of the infrared absorbing particles, and the like. For example, it is preferable to add the dispersant in an amount of 10 parts by mass or more and 500 parts by mass or less based on 100 parts by mass of the infrared absorbing particles because it is easy to prepare a dispersion liquid with a particularly good dispersion state. The amount of the dispersant added is more preferably 10 parts by mass or more and 100 parts by mass or less, and even more preferably 20 parts by mass or more and 50 parts by mass or less.
(c) Dispersion medium The dispersion medium may be any dispersion medium as long as it can disperse the above-mentioned infrared absorbing particles and dispersant to form a dispersion liquid, and for example, various organic compounds can be used.

As the dispersion medium, for example, one or more types selected from aromatic hydrocarbons such as toluene and xylene can be suitably used.

In the dispersion liquid preparation process, a dispersion liquid can be prepared by mixing infrared absorbing particles, a dispersant, and a dispersion medium. In order to disperse the particles, it is preferable to pulverize the infrared absorbing particles at the same time as mixing.

The mixing means used for mixing and pulverizing the infrared absorbing particles, dispersant, and dispersion medium is not particularly limited, but for example, one or more types selected from bead mills, ball mills, sand mills, paint shakers, ultrasonic homogenizers, etc. can be used. In particular, as the mixing means, it is more preferable to use a media agitation mill such as a bead mill, a ball mill, a sand mill, or a paint shaker using media such as beads, balls, and Ottawa sand. This is because the use of a media agitation mill allows the infrared absorbing particles to have a desired dispersed particle size particularly in a short time, which is preferable from the viewpoint of productivity and suppression of contamination with impurities.
(2) Dispersion medium reduction step In the dispersion medium reduction step, the dispersion medium can be evaporated and dried from the dispersion liquid.

In the dispersion medium reduction step, it is preferable that the dispersion medium is sufficiently evaporated from the dispersion liquid so that the infrared absorbing particles can be recovered.

The specific means for evaporating the dispersion medium is not particularly limited, but for example, a dryer such as an oven, a vacuum fluid dryer such as an evaporator or a vacuum crusher, a spray dryer such as a spray dryer, etc. may be used. can.

Further, the degree to which the dispersion medium is evaporated is not particularly limited, but it is preferable that the content thereof can be sufficiently reduced so that, for example, powdery infrared absorbing particles can be obtained after the dispersion medium reduction step.

By evaporating the dispersion medium, the dispersant is disposed around the infrared absorbing particles, and it is possible to obtain infrared absorbing particles whose surfaces are hydrophobized. For this reason, it becomes possible to increase the adhesion between the hydrophobically treated infrared absorbing particles and the coating resin obtained by polymerizing the coating resin raw material, and by the polymerization process described below, at least the surface of the infrared absorbing particles is It becomes possible to place the coating resin in a part.
(3) Raw material mixture preparation step In the raw material mixture preparation step, the infrared absorbing particles recovered after the dispersion medium reduction step, coating resin raw material, organic solvent, emulsifier, water, and polymerization initiator are mixed. , a raw material mixture can be prepared.

The infrared absorbing particles recovered after the dispersion medium reduction step may have the dispersant supplied in the dispersion liquid preparation step attached to the surface of the particles, resulting in dispersant-containing infrared absorbing particles. Therefore, when the dispersant is attached to the infrared absorbing particles in this way, the infrared absorbing particles containing the dispersant recovered after the dispersion medium reduction step should be used as the infrared absorbing particles in the raw material mixture preparation step. become.

Each material other than the infrared absorbing particles used in the raw material mixture preparation step will be explained below.
(a) Coating resin raw material The coating resin raw material is polymerized in the polymerization step described below, and becomes a coating resin disposed on at least a portion of the surface of the infrared absorbing particles. Therefore, as the coating resin raw material, various monomers and the like that can be polymerized to form a desired coating resin can be selected.

The coating resin after polymerization is not particularly limited, and may be, for example, one or more resins selected from thermoplastic resins, thermosetting resins, photocuring resins, and the like.

Examples of thermoplastic resins include polyester resin, polycarbonate resin, acrylic resin, polystyrene resin, polyamide resin, vinyl chloride resin, olefin resin, fluororesin, polyvinyl acetate resin, thermoplastic polyurethane resin, acrylonitrile butadiene styrene resin, and polyvinyl resin. Examples include acetal resin, acrylonitrile/styrene copolymer resin, and ethylene/vinyl acetate copolymer resin.

Examples of the thermosetting resin include phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, thermosetting polyurethane resin, polyimide resin, and silicone resin.

Examples of the photocurable resin include resins that are cured by irradiation with ultraviolet light, visible light, or near-infrared light.

In particular, coating resins include polyester resin, polycarbonate resin, acrylic resin, polystyrene resin, polyamide resin, vinyl chloride resin, olefin resin, fluororesin, polyvinyl acetate resin, polyurethane resin, acrylonitrile butadiene styrene resin, polyvinyl acetal resin, and acrylonitrile.・Contains one or more types selected from styrene copolymer resin, ethylene/vinyl acetate copolymer resin, phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyimide resin, and silicone resin. It is preferable to do so. Note that as the polyurethane resin, either thermoplastic polyurethane or thermosetting polyurethane can be used.

Further, as the coating resin, a photocurable resin can also be suitably used, and the photocurable resin may contain a resin that is cured by irradiation with ultraviolet rays, visible light, or infrared light, as described above. I can do it.

Among these, the coating resin is preferably a resin to which mini-emulsion polymerization can be applied, and more preferably contains, for example, a polystyrene resin. In addition, when the coating resin is polystyrene, styrene can be used as the coating resin raw material.

Moreover, a polyfunctional vinyl monomer such as divinylbenzene and ethylene glycol dimethacrylate can also be added as a crosslinking agent.
(b) Organic Solvent There are no particular limitations on the organic solvent either, but any solvent may be used as long as it is water-insoluble. Among these, those with a low molecular weight are preferred, such as long-chain alkyl compounds such as hexadecane, methacrylic acid alkyl esters with a long alkyl moiety such as dodecyl methacrylate and stearyl methacrylate, higher alcohols such as cetyl alcohol, olive oil, etc. One or more types selected from the following may be mentioned.

As the organic solvent, long-chain alkyl compounds are particularly preferred, and hexadecane is even more preferred.
(c) Emulsifier The emulsifier, that is, the surfactant, may be cationic, anionic, nonionic, etc., and is not particularly limited.

Examples of cationic emulsifiers include alkylamine salts and quaternary ammonium salts.

Examples of anionic emulsifiers include acid salts and ester salts.

Examples of nonionic emulsifiers include various esters, various ethers, various ester ethers, and alkanolamides.

As the emulsifier, for example, one or more types selected from the above-mentioned materials can be used.

Among these, it is preferable to use a cationic emulsifier, that is, a surfactant exhibiting cationic properties, from the viewpoint that the infrared absorbing particles particularly easily form organic-inorganic hybrid infrared absorbing particles.

In particular, when an amine compound is used as a dispersant, it is preferable to use one or more cationic emulsifiers selected from dodecyltrimethylammonium chloride (DTAC), cetyltrimethylammonium chloride (CTAC), etc.

Further, when an amine compound is used as a dispersant, it may be difficult to form organic-inorganic hybrid infrared absorbing particles if sodium dodecyl sulfate (SDS), which is an anionic emulsifier, is used. When preparing the raw material mixture, the emulsifier can be added as an aqueous solution, for example, by adding it to water that is added at the same time. At this time, it is preferable to add it as an aqueous solution adjusted to have a concentration of 1 to 10 times the critical micelle concentration (CMC).
(d) Polymerization initiator As the polymerization initiator, one or more types selected from various polymerization initiators such as radical polymerization initiators and ionic polymerization initiators can be used, and the polymerization initiator is not particularly limited.

Examples of the radical polymerization initiator include azo compounds, dihalogens, organic peroxides, and the like. Further, redox initiators that combine an oxidizing agent and a reducing agent, such as hydrogen peroxide and iron (II) salt, persulfate and sodium bisulfite, can also be mentioned.

Examples of the ionic polymerization initiator include nucleophiles such as n-butyllithium, electrophiles such as protonic acids, Lewis acids, halogen molecules, and carbocations.

Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), potassium peroxodisulfate (KPS), and 2,2'-azobis(2-methylpropionamidine) dihydrochloride (V-50). ), 2,2′-azobis(2-methyl-N-(2-hydroxyethyl)propionamidine) (VA-086), and the like can be suitably used.

When preparing the raw material mixture, the polymerization initiator can be added to the organic phase or the aqueous phase depending on its type. For example, when using 2,2'-azobisisobutyronitrile (AIBN), When using potassium peroxodisulfate (KPS) or 2,2'-azobis(2-methylpropionamidine) dihydrochloride (V-50), it can be added to the aqueous phase.

In the raw material mixture preparation step, it is sufficient if the raw material mixture can be prepared by mixing the infrared absorbing particles recovered after the dispersion medium reduction step, the coating resin raw material, an organic solvent, an emulsifier, water, and a polymerization initiator. . For this reason, although the procedure for preparing the raw material mixture is not particularly limited, for example, a mixture containing an emulsifier may be prepared in advance as an aqueous phase. Further, as the organic phase, a mixed solution can be prepared in which the coating resin raw material and the infrared absorbing particles recovered after the dispersion medium reduction step are dispersed in an organic solvent.

Note that the polymerization initiator can be added to the aqueous phase or the organic phase depending on the type of polymerization initiator used as described above.

Then, by adding and mixing the organic phase to the aqueous phase, a raw material mixture can be prepared.

It is preferable to stir sufficiently after adding the organic phase to the aqueous phase so that the coating resin can be more uniformly disposed on the surface of the infrared absorbing particles. That is, the raw material mixture preparation step includes a mixing step of mixing the infrared absorbing particles recovered after the dispersion medium reduction step, a coating resin raw material, an organic solvent, an emulsifier, water, and a polymerization initiator. It is preferable to further include a stirring step of stirring the obtained liquid mixture.

In the stirring step, stirring can be performed using, for example, a stirrer. When performing the stirring step, the degree of stirring is not particularly limited, but for example, it is preferable to perform the stirring so that oil-in-water droplets are formed in which infrared absorbing particles encapsulated in the coating resin raw material are dispersed in the water phase. .

The amount of the polymerization initiator added is not particularly limited and can be arbitrarily selected. The amount of the polymerization initiator added can be selected depending on the type of coating resin raw material and polymerization initiator, the size of the oil droplets that are the mini-emulsion, the ratio of the coating resin raw material to the infrared absorbing particles, and the like. For example, if the amount of the polymerization initiator added is 0.01 mol% or more and 1000 mol% or less based on the coating resin raw material, it is easy to obtain organic-inorganic hybrid infrared absorbing particles in which the infrared absorbing particles are sufficiently covered with the coating resin. Therefore, it is preferable. The amount of the polymerization initiator added is more preferably 0.1 mol% or more and 200 mol% or less, and even more preferably 0.2 mol% or more and 100 mol% or less, based on the coating resin raw material.
(4) Stirring step In the stirring step, the raw material mixture obtained in the raw material mixture preparation step can be stirred while being cooled.

The degree of stirring in the stirring step is not particularly limited and can be selected arbitrarily. For example, stirring should be carried out so that the size of the oil-in-water droplets, which is an O/W type emulsion in which infrared absorbing particles encapsulated in the coating resin raw material are dispersed in the water phase, is a mini-emulsion with a diameter of 50 nm or more and 500 nm or less. It is preferable to do so.

A mini-emulsion is obtained by adding to the organic phase a substance that is hardly soluble in water, ie a hydrophobe, and applying strong shearing force. Examples of the hydrophob include the organic solvents mentioned above in the raw material mixture preparation step mentioned above. Further, as a method of applying strong shearing force, for example, a method of applying ultrasonic vibration to the raw material mixture using a homogenizer or the like can be mentioned.

In the stirring step, it is preferable to stir the raw material mixture while cooling it as described above. This is because by cooling the raw material mixture, a mini-emulsion can be formed while suppressing the progress of the polymerization reaction.

Note that the degree to which the raw material mixture is cooled is not particularly limited, but it is preferable to cool it using a refrigerant at 0° C. or lower, for example, in an ice bath or the like.
(5) Polymerization step In the polymerization step, a polymerization reaction of the resin raw material for coating can be performed after performing a deoxidation treatment to reduce the amount of oxygen in the raw material mixture.

In the polymerization step, the coating resin raw material is polymerized, and the coating resin can be placed on at least a portion of the surface of the infrared absorbing particles.

Although the conditions in the polymerization step are not particularly limited, deoxidation treatment to reduce the amount of oxygen in the raw material mixture can be performed before starting the polymerization. The specific method of deoxidizing treatment is not particularly limited, but examples include a method of performing ultrasonic irradiation and a method of blowing an inert gas into the raw material mixture.

The specific conditions for carrying out the polymerization reaction are not particularly limited, as they can be arbitrarily selected depending on the coating resin raw material added to the raw material mixture, but, for example, heating the raw material mixture Alternatively, the polymerization reaction can be caused to proceed by irradiating with light of a predetermined wavelength.

According to the method for producing organic-inorganic hybrid infrared absorbing particles of the present embodiment described above, an organic material such as a resin is placed on at least a part of the surface of the infrared absorbing particles, which has been difficult in the past, and organic-inorganic hybrid Infrared absorbing particles can be obtained. Therefore, even if exposed to a chemical environment such as a high temperature acid or alkali, the infrared absorbing particles can be prevented from coming into direct contact with chemical components such as acids or alkalis, resulting in excellent chemical resistance and reduced infrared absorption characteristics. can be restrained from doing so.
2. Organic-Inorganic Hybrid Infrared Absorbing Particles Organic-inorganic hybrid infrared absorbing particles that can be suitably used in the infrared absorbing fiber of this embodiment will be described. The organic-inorganic hybrid infrared absorbing particles can include infrared absorbing particles and a coating resin that covers at least a portion of the surface of the infrared absorbing particles. The organic-inorganic hybrid infrared absorbing particles can be manufactured, for example, by the method for manufacturing organic-inorganic hybrid infrared absorbing particles described above. For this reason, explanations of some of the matters already explained will be omitted.

In this way, by placing a coating resin on the surface of infrared absorbing particles that covers at least a portion of the surface, which has been difficult in the past, it is possible to eliminate the possibility of exposure to chemicals such as high-temperature acids or alkalis. Even in this case, direct contact of the infrared absorbing particles with chemical components such as acids or alkalis can be suppressed. Therefore, the infrared absorbing fiber of this embodiment containing such organic-inorganic hybrid infrared absorbing particles has excellent chemical resistance and can suppress a decrease in infrared absorbing properties.

The infrared absorbing particles have already been explained in the method for producing organic-inorganic hybrid infrared absorbing particles, so the explanation will be omitted, but for example, it is preferable to use infrared absorbing particles containing various materials containing free electrons. Infrared absorbing particles containing various inorganic materials can be more preferably used.

As the infrared absorbing particles, infrared absorbing particles containing one or more types selected from tungsten oxides having oxygen vacancies and composite tungsten oxides can be particularly preferably used. In this case, specifically, the infrared absorbing particles are, for example, tungsten oxide represented by the general formula W _y O _z (W: tungsten, O: oxygen, 2.2≦z/y≦2.999), and General formula M _x W _y O _z (Element M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt , Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo , Ta, Re, Be, Hf, Os, Bi, I, expressed as 0.001≦x/y≦1, 2.0≦z/y≦3.0) It is preferable to contain one or more types selected from composite tungsten oxides.

Furthermore, since the coating resin has already been explained in the method for producing organic-inorganic hybrid infrared absorbing particles, its explanation will be omitted here, but for example, one type selected from thermoplastic resins, thermosetting resins, photocuring resins, etc. The above resins can be used. In particular, coating resins include polyester resin, polycarbonate resin, acrylic resin, polystyrene resin, polyamide resin, vinyl chloride resin, olefin resin, fluororesin, polyvinyl acetate resin, polyurethane resin, acrylonitrile butadiene styrene resin, polyvinyl acetal resin, and acrylonitrile.・Contains one or more types selected from styrene copolymer resin, ethylene/vinyl acetate copolymer resin, phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyimide resin, and silicone resin. It is preferable to do so. Note that as the polyurethane resin, either thermoplastic polyurethane or thermosetting polyurethane can be used.

Further, as the coating resin, a photocurable resin can also be suitably used, and as the photocurable resin, a resin that is cured by irradiation with ultraviolet light, visible light, or infrared light is preferably used as the photocurable resin. be able to.

Among these, the coating resin is preferably a resin to which mini-emulsion polymerization can be applied, and more preferably contains, for example, a polystyrene resin.

The organic-inorganic hybrid infrared absorbing particles described above have a coating resin, which is an organic material, placed on at least a portion of the surface of the infrared absorbing particles, which has been difficult to do in the past. Therefore, even if exposed to a high-temperature chemical environment such as acid or alkali, the infrared absorbing particles can be prevented from coming into direct contact with chemical components such as acid or alkali, resulting in excellent chemical resistance and reduced infrared absorption properties. can be restrained from doing so. Infrared absorbing fibers using the organic-inorganic hybrid infrared absorbing particles can also have chemical resistance.

The infrared absorbing fiber of this embodiment can include fibers in addition to the organic-inorganic hybrid infrared absorbing particles described above.

The infrared absorbing fiber of this embodiment can be obtained by dispersing the above-mentioned organic-inorganic hybrid infrared absorbing particles in an appropriate medium and containing the dispersion in one or more parts selected from the inside and the surface of the fiber. It can be manufactured by The fibers and the like will be explained below.
3. Fibers Various types of fibers can be selected from the infrared absorbing fibers of this embodiment depending on the purpose.

The fibers included in the infrared absorbing fibers of this embodiment can include, for example, one or more types selected from synthetic fibers, semi-synthetic fibers, natural fibers, recycled fibers, and inorganic fibers. Specifically, the fibers include one or more types selected from the fiber group consisting of synthetic fibers, semi-synthetic fibers, natural fibers, regenerated fibers, and inorganic fibers, and one or more types selected from the above fiber groups. One or more types of mixed yarns selected from blended yarns, doubled yarns, mixed fibers, etc. may be used. In consideration of incorporating the organic-inorganic hybrid infrared absorbing particles into the fibers by a simple method and maintaining heat retention, the fibers preferably include synthetic fibers, and more preferably synthetic fibers.

When the infrared absorbing fiber of this embodiment includes synthetic fiber as the fiber, the specific type of the synthetic fiber is not particularly limited. The synthetic fibers are selected from, for example, polyurethane fibers, polyamide fibers, acrylic fibers, polyester fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, polyether ester fibers, etc. One or more of the following can be suitably used.

Examples of the polyamide fiber include one or more types selected from nylon, nylon 6, nylon 66, nylon 11, nylon 610, nylon 612, aromatic nylon, aramid, and the like.

Examples of the acrylic fiber include one or more selected from polyacrylonitrile, acrylonitrile-vinyl chloride copolymer, modacrylic, and the like.

Examples of the polyester fiber include one or more types selected from polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and the like.

Examples of the polyolefin fiber include one or more types selected from polyethylene, polypropylene, polystyrene, and the like.

Examples of polyvinyl alcohol fibers include vinylon and the like.

Examples of the polyvinylidene chloride fiber include vinylidene.

Examples of the polyvinyl chloride fiber include polyvinyl chloride.

Examples of the polyetherester fiber include one or more types selected from Lexe, Success, and the like.

When the infrared absorbing fiber of the present embodiment includes semi-synthetic fibers as fibers, the semi-synthetic fibers preferably include one or more types selected from cellulose fibers, protein fibers, chlorinated rubber, hydrochloric acid rubber, etc. .

Examples of cellulose fibers include one or more types selected from acetate, triacetate, oxidized acetate, and the like.

Examples of protein fibers include Promix and the like.

When the infrared absorbing fiber of the present embodiment includes natural fibers as fibers, it is preferable that the natural fibers include one or more types selected from, for example, vegetable fibers, animal fibers, mineral fibers, and the like.

Examples of the vegetable fiber include one or more selected from cotton, kapok, flax, hemp, jute, Manila hemp, sisal hemp, New Zealand hemp, Rabun hemp, palm, rush, and wheat straw.

Examples of animal fibers include one or more selected from wools such as wool, goat hair, mohair, cashmere, alpaca, angora, camel, and vicuña, silk, down, and feathers.

Examples of the mineral fiber include one or more types selected from asbestos, asbestos, and the like.

When the infrared absorbing fiber of the present embodiment includes a regenerated fiber as a fiber, the regenerated fiber is, for example, one or more types selected from cellulose fiber, protein fiber, algin fiber, rubber fiber, chitin fiber, mannan fiber, etc. It is preferable to include.

Examples of cellulose fibers include one or more selected from rayon, viscose rayon, cupro, polynosic, cuprammonium rayon, and the like.

Examples of the protein fiber include one or more types selected from casein fiber, peanut protein fiber, corn protein fiber, soybean protein fiber, regenerated silk thread, and the like.

When the infrared absorbing fiber of the present embodiment includes inorganic fibers, the inorganic fibers preferably include one or more types selected from, for example, metal fibers, carbon fibers, silicate fibers, and the like.

Examples of the metal fibers include one or more types selected from metal fibers, gold threads, silver threads, heat-resistant alloy fibers, and the like.

Examples of the silicate fibers include one or more types selected from glass fibers, mineral fibers, rock fibers, and the like.

The cross-sectional shape of the fibers included in the infrared absorbing fibers of this embodiment is not particularly limited, but examples thereof include one or more types selected from circular, triangular, hollow, flat, Y-shaped, star-shaped, core-sheath type, etc. It will be done. Note that the infrared absorbing fiber of this embodiment can also contain fibers with different cross-sectional shapes at the same time.

The organic-inorganic hybrid infrared absorbing particles can be arranged in one or more parts selected from inside and on the surface of the fiber in various ways depending on the cross-sectional shape of the fiber and the like. For example, when the cross-sectional shape of the fiber is a core-sheath type, the organic-inorganic hybrid infrared absorbing particles may be contained in the core portion of the fiber or in the sheath portion. Further, the shape of the fibers of the infrared absorbing fibers of this embodiment may be filaments (long fibers) or staples (short fibers).
4. Additives The infrared absorbing fiber of this embodiment may contain antioxidants, flame retardants, deodorants, insect repellents, antibacterial agents, ultraviolet absorbers, etc., depending on the purpose, within a range that does not impair the performance of the fibers it contains. Can be included.

Moreover, in addition to the infrared absorbing material, the infrared absorbing fiber of this embodiment can further contain particles having the ability to emit far infrared rays. Particles capable of emitting far-infrared rays can be placed, for example, in one or more selected parts of the interior and surface of the fiber. Examples of particles having the ability to emit far infrared rays include metal oxides such as ZrO ₂ , SiO ₂ , TiO ₂ , Al ₂ O ₃ , MnO ₂ , MgO, Fe ₂ O ₃ and CuO, ZrC, SiC, and TiC. At least one selected from carbides such as ZrN, Si ₃ N ₄ , nitrides such as AlN, etc. can be suitably used.

The organic-inorganic hybrid infrared absorbing particles, which are both an infrared absorbing material and a near-infrared absorbing material, which the infrared absorbing fiber of this embodiment has have a property of absorbing solar energy with a wavelength of 0.3 μm or more and 3 μm or less. It selectively absorbs near-infrared light in the vicinity of 0.9 μm or more and 2.2 μm or less, and converts it into heat or re-radiates it.

On the other hand, the above-mentioned particles that emit far-infrared rays have the ability to receive the energy absorbed by the organic-inorganic hybrid infrared-absorbing particles, which are near-infrared absorbing materials, convert the energy into thermal energy at mid- and far-infrared wavelengths, and radiate it. are doing. For example, ZrO ₂ particles convert this energy into thermal energy with a wavelength of 2 μm or more and 20 μm or less and radiate it. Therefore, particles capable of emitting far-infrared rays and organic-inorganic hybrid infrared-absorbing particles coexist within the fiber or on the surface, so that, for example, sunlight energy absorbed by the organic-inorganic hybrid infrared-absorbing particles can be absorbed into the fiber.・It is efficiently consumed on the surface, resulting in more effective heat retention.

As described above, in the infrared absorbing fiber of this embodiment, organic-inorganic hybrid infrared absorbing particles can be arranged in one or more parts selected from inside and on the surface of the fiber. That is, organic-inorganic hybrid infrared absorbing particles can be placed both inside and on the fiber, or either inside or on the surface of the fiber.

As mentioned above, since the organic-inorganic hybrid infrared absorbing particles have excellent chemical resistance, the infrared absorbing fiber of this embodiment containing the organic-inorganic hybrid infrared absorbing particles can also have excellent chemical resistance. can.
[Method for manufacturing infrared absorbing fiber]
The method for producing the infrared absorbing fiber of this embodiment is not particularly limited, and can be produced by arranging organic-inorganic hybrid infrared absorbing particles on one or more portions selected from the surface and inside of the fiber.

For example, the infrared absorbing fiber of this embodiment can be manufactured by the following manufacturing methods (a) to (d).

(a) A method in which organic-inorganic hybrid infrared absorbing particles are directly mixed into a raw material polymer for synthetic fibers and then spun.
(b) A method in which a masterbatch is prepared in advance in which a part of the raw material polymer contains organic-inorganic hybrid infrared absorbing particles at a high concentration, and this is diluted to a predetermined concentration at the time of spinning, and then spun.
(c) Organic-inorganic hybrid infrared absorbing particles are uniformly dispersed in a raw material monomer or oligomer solution in advance, and the desired raw material polymer is synthesized using this dispersion, and at the same time, the organic-inorganic hybrid infrared absorbing particles are A method in which the material is dispersed in a raw material polymer and then spun.

(d) A method in which organic-inorganic hybrid infrared absorbing particles are attached to the surface of fibers obtained by spinning in advance using a binder or the like.
Here, the above-mentioned manufacturing methods (a) to (d) for incorporating organic-inorganic hybrid infrared-absorbing particles into the fibers of the infrared-absorbing fiber of the present embodiment described above will be explained by giving specific examples.

Method (a):
For example, the case where polyester fiber is used as the fiber will be explained.
An organic-inorganic hybrid infrared absorbing particle dispersion is added to polyethylene terephthalate resin pellets, which is a thermoplastic resin, and the mixture is uniformly mixed in a blender, and then the solvent is removed. The mixture from which the solvent has been removed is melt-kneaded using a twin-screw extruder to obtain a masterbatch containing organic-inorganic hybrid infrared absorbing particles. This organic-inorganic hybrid infrared absorbing particle-containing masterbatch is melt-mixed at around the melting temperature of the resin, and then spun, for example, according to various known methods.

At this time, a dispersant can be added in order to improve the dispersibility of the organic-inorganic hybrid infrared absorbing particles in the polyethylene terephthalate resin. The dispersant is not limited as long as it can disperse the organic-inorganic hybrid infrared absorbing particles in polyethylene terephthalate resin or fibers obtained by spinning a masterbatch containing the resin. For example, the dispersant applied to polyethylene terephthalate resin is not particularly limited, and is preferably a polymer dispersant, such as polyester, polyether, polyacrylic, polyurethane, polyamine, or polystyrene. A main chain selected from polyester, polyether, polyacrylic, polyurethane, polyamine, polystyrene, and aliphatic. More preferably, it is a dispersant having a copolymerized main chain.

Further, the dispersant preferably has one or more functional groups selected from a group containing an amine, a hydroxyl group, a carboxyl group, a group containing a carboxyl group, a sulfo group, a phosphoric acid group, or an epoxy group. . Particularly preferred is a polyacrylic type having an amine-containing group as a functional group. The dispersant having any of the above-mentioned functional groups is adsorbed onto the surface of the organic-inorganic hybrid infrared-absorbing particles, and can more reliably prevent aggregation of the organic-inorganic hybrid infrared-absorbing particles. Therefore, the organic-inorganic hybrid infrared absorbing particles can be more uniformly dispersed, and thus can be suitably used.

Such dispersants include Solsperse (registered trademark) (the same applies hereinafter) 9000, 12000, 17000, 20000, 21000, 24000, 26000, 27000, 28000, 32000, 35100, 54000, Solsix 250, manufactured by Japan Lubrizol Co., Ltd. , EFKA (registered trademark) manufactured by Efka Additives (hereinafter the same) 4008, EFKA4009, EFKA4010, EFKA4015, EFKA4046, EFKA4047, EFKA4060, EFKA4080, EFKA7462, EFKA4020, EFKA4050, EFKA40 55, EFKA4585, EFKA4400, EFKA4401, EFKA4402, EFKA4403, EFKA4300, EFKA4320, EFKA4330, EFKA4340, EFKA6220, EFKA6225, EFKA6700, EFKA6780, EFKA6782, EFKA8503, Ajisper (registered trademark) manufactured by Ajinomoto Fine Techno Co., Inc. (same hereinafter) PB821, Ajisper PB8 22, Ajisper PB824, Ajisper PB881, Famex L- 12. DisperBYK (registered trademark) manufactured by Big Chemie Japan Co., Ltd. (same hereinafter) 101, DisperBYK106, DisperBYK108, DisperBYK116, DisperBYK130, DisperBYK140, DisperBYK142, DisperBYK14 5, DisperBYK161, DisperBYK162, DisperBYK163, DisperBYK164, DisperBYK166, DisperBYK167, DisperBYK168DisperBYK171, DisperBYK180, Dispe rBYK182 , DisperBYK2000, DisperBYK2001, DisperBYK2009, DisperBYK2013, DisperBYK2022, DisperBYK2025, DisperBYK2050, DisperBYK2155, DisperBY K2164, BYK350, BYK354, BYK355, BYK356, BYK358, BYK361, BYK381, BYK392, BYK394, BYK300, BYK3441, Disparon (registered trademark) manufactured by Kusumoto Kasei Co., Ltd. ) (same below) 1831, Disparon 1850, Disparon 1860, Disparon DA-400N, Disparon DA-703-50, Disparon DA-725, Disparon DA-705, Disparon DA-7301, Disparon DN-900, Disparon NS-5210, Examples include Disparon NVI-8514L and TERPLUS (registered trademark) MD1000, D 1180, and D 1130 manufactured by Otsuka Chemical Co., Ltd.

Method (b):
A masterbatch containing organic-inorganic hybrid infrared-absorbing particles is prepared using the same method as in (a), and the masterbatch and a masterbatch made of polyethylene terephthalate without addition of organic-inorganic hybrid infrared-absorbing particles are mixed as desired. The resins are melt-mixed at a mixing ratio near the melting temperature of the resin and spun according to a known method.

Method (c):
For example, a case where urethane fibers are used as the fibers will be explained.

A polymeric diol containing organic-inorganic hybrid infrared absorbing particles and an organic diisocyanate are reacted in a twin-screw extruder to synthesize an isocyanate group-terminated prepolymer, and then a chain extender is reacted thereto to form a polyurethane solution (raw material polymer). ) is manufactured. The polyurethane solution is spun according to various known methods.

Method (d):
For example, a case will be explained in which organic-inorganic hybrid infrared absorbing particles are attached to the surface of natural fibers.
First, a treatment liquid is prepared by mixing organic-inorganic hybrid infrared absorbing particles, one or more binder resins selected from acrylic, epoxy, urethane, and polyester, and a solvent such as water.

Next, the natural fibers are immersed in the prepared treatment liquid, or the natural fibers are impregnated with the prepared treatment liquid by padding, printing, spraying, etc., and then dried. Thereby, the organic-inorganic hybrid infrared absorbing particles can be attached to the natural fiber. In addition to the above-mentioned natural fibers, the method (d) can be applied to any of semi-synthetic fibers, regenerated fibers, inorganic fibers, blends, yarns, mixed fibers, etc. thereof.

Note that when carrying out the methods (a) to (d), the dispersion method for dispersing the organic-inorganic hybrid infrared absorbing particles in a dispersion medium is not particularly limited, and the organic-inorganic hybrid infrared absorbing particles are dispersed in a liquid, that is, a dispersion medium. Any method that can achieve uniform dispersion may be used. For example, methods such as a medium stirring mill, a ball mill, a sand mill, and an ultrasonic dispersion method can be suitably applied.

Furthermore, the dispersion medium for the organic-inorganic hybrid infrared absorbing particles is not particularly limited and can be selected depending on the fibers to be mixed. One or more types selected from organic solvents and water can be used.

Furthermore, when attaching and mixing organic-inorganic hybrid infrared absorbing particles to fibers or polymers that are raw materials thereof, a dispersion of organic-inorganic hybrid infrared absorbing particles may be directly mixed with fibers or polymers that are raw materials thereof. do not have. Furthermore, if necessary, an acid or alkali may be added to the dispersion of the organic-inorganic hybrid infrared-absorbing particles to adjust the pH. It is also possible to add surfactants, coupling agents, etc.

The content of organic-inorganic hybrid infrared absorbing particles contained in the infrared absorbing fiber of this embodiment is not particularly limited. For example, the content of organic-inorganic hybrid infrared absorbing particles in the infrared absorbing fiber of this embodiment is preferably 0.001% by mass or more and 80% by mass or less. Furthermore, when considering the weight and raw material cost of the infrared absorbing fiber after addition of the organic-inorganic hybrid infrared absorbing particles, the content ratio of the organic-inorganic hybrid infrared absorbing particles in the infrared absorbing fiber is 0.005% by mass or more and 50% by mass. It is more preferable that it is below.

When the content of organic-inorganic hybrid infrared absorbing particles in the infrared absorbing fiber is 0.001% by mass or more, a sufficient infrared absorbing effect can be obtained, for example, even if the fabric using the infrared absorbing fiber is thin.

Further, it is preferable that the content of organic-inorganic hybrid infrared absorbing particles in the infrared absorbing fiber is 80% by mass or less, since deterioration of spinnability due to filter clogging or yarn breakage in the spinning process can be avoided, and especially It is more preferable if it is 50% by mass or less. Further, since the amount of organic-inorganic hybrid infrared absorbing particles added can be small, the physical properties of the fibers are hardly impaired, which is preferable.

As explained above, according to the infrared absorbing fiber according to the present embodiment, by arranging infrared absorbing particles inside or on the surface of the fiber, infrared rays from sunlight etc. can be efficiently absorbed, and the fiber has excellent heat retention properties. It is possible to provide fibers that are Further, since the infrared absorbing fiber according to this embodiment has high chemical resistance, the infrared absorbing characteristic does not deteriorate even when exposed to a chemical environment such as a high temperature acid or alkali. As a result, the infrared absorbing fiber according to the present embodiment can be used in various applications such as cold-weather clothing, sports clothing, stockings, curtains, and other textile products that require heat retention, and other industrial textile products. .
[Fiber products]
The textile product of this embodiment is formed by processing the above-mentioned infrared-absorbing fiber, and can contain the above-mentioned infrared-absorbing fiber. Note that the textile product of this embodiment can also be made of the above-mentioned infrared absorbing fiber.

The textile product of this embodiment, which includes the infrared absorbing fiber described above, has excellent properties such as a visible light absorption rate of 20% or less and a solar radiation absorption rate of 47% or more. The fact that the visible light absorption rate is 20% or less and the solar radiation absorption rate is 47% or more indicates that the textile product is light in color and has an excellent infrared absorption effect.

The textile product of this embodiment containing the infrared absorbing fiber of this embodiment has excellent chemical resistance, and even when immersed in a 0.01 mol/L sodium hydroxide aqueous solution maintained at 80°C for 30 minutes, The solar radiation absorption rate is maintained at over 47%. That is, the textile product of this embodiment can have chemical resistance.

The present invention will be specifically described below with reference to Examples. However, the present invention is not limited to the following examples.

The optical properties of the fiber products obtained in Examples and Comparative Examples were measured using a spectrophotometer U-4100 (manufactured by Hitachi, Ltd.). Visible light transmittance, visible light reflectance, solar transmittance, and solar reflectance were measured according to JIS R 3106.

To measure the crystallite diameter of the infrared absorbing particles, dry powder of the infrared absorbing particles obtained by removing the solvent from a dispersion of the infrared absorbing particles was used. Then, the X-ray diffraction pattern of the infrared absorbing particles was measured by powder X-ray diffraction method (θ-2θ method) using a powder X-ray diffraction device (X'Pert-PRO/MPD manufactured by PANalytical, Spectris Co., Ltd.). The crystal structure contained in the infrared absorbing particles was identified from the obtained X-ray diffraction pattern, and the crystallite diameter was calculated using the Rietveld method.
[Example 1]
Infrared absorbing fibers and textile products were produced and evaluated using the following procedure.
1. Production of organic-inorganic hybrid infrared absorbing particles Organic-inorganic hybrid infrared absorbing particles used for infrared absorbing fibers were produced according to the following steps.
(Dispersion liquid preparation process)
In the dispersion liquid preparation step, a dispersion liquid containing infrared absorbing particles, a dispersant, and a dispersion medium was prepared.

As the infrared absorbing particles, hexagonal cesium tungsten bronze (Cs _0.33 WO _z , 2.0 z≦3.0) was prepared.

As the dispersant, a polymer dispersant which is a copolymer of styrene and 2-(dimethylamino)ethyl methacrylate was prepared.

Moreover, toluene was prepared as a dispersion medium.

Then, a mixed solution obtained by mixing 10% by mass of infrared absorbing particles, 3% by mass of dispersant, and 87% by mass of dispersion medium was loaded into a paint shaker containing 0.3 mmφ ZrO ₂ beads. The mixture was subjected to pulverization and dispersion treatment for 10 hours to obtain a dispersion of Cs _0.33 WO _z particles according to Example 1.
(Dispersion medium reduction process)
Toluene as a dispersion medium was removed from the dispersion of Cs _0.33 WO _z particles obtained in the dispersion preparation step using an evaporator, and infrared absorbing particles were recovered. The recovered infrared absorbing particles become dry powder of Cs _0.33 WO _z particles containing a polymer dispersant.

The crystallite diameter of the collected infrared absorbing particles, ie, Cs _0.33 WO _z particles, was measured and found to be 16 nm.

Note that the crystallite diameter was measured and calculated by the method described above.
(Raw material mixture preparation process)
0.05 g of infrared absorbing particles obtained in the dispersion medium reduction step, 1.0 g of styrene as a coating resin raw material, and 0.065 g of hexadecane as an organic solvent were mixed to form an organic phase.

Separately from the organic phase, dodecyltrimethylammonium chloride as an emulsifier, 0.013 g of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (V-50) as a polymerization initiator, and water were mixed to form 10 g of an aqueous phase. Note that when forming the aqueous phase, dodecyltrimethylammonium chloride as an emulsifier was added to water so that the concentration was 1.5 times the critical micelle concentration. Further, the polymerization initiator was added in an amount of 0.5 mol% relative to the styrene added to the organic phase.

Thereafter, a raw material mixture was prepared by adding the organic phase to the aqueous phase.
(stirring process)
The raw material mixture prepared in the raw material mixture preparation step was irradiated with high-power ultrasound for 15 minutes while being cooled in an ice bath to obtain a mini-emulsion.
(Polymerization process)
After the stirring step, the raw material mixture was subjected to nitrogen bubbling for 15 minutes in an ice bath to perform deoxidation treatment.

Thereafter, heat treatment was performed at 70° C. for 6 hours in a nitrogen atmosphere to advance the polymerization reaction of styrene, thereby obtaining an organic-inorganic hybrid infrared absorbing particle dispersion.

The resulting dispersion containing organic-inorganic hybrid infrared absorbing particles was diluted and transferred to a microgrid for TEM observation, and the transferred material was observed by TEM. The TEM image is shown in Figure 2. From the TEM image, particles 21 containing composite tungsten oxide, which appear black as infrared absorbing particles, are encapsulated in a coating 22 of polystyrene, which is a coating resin, and appear gray, forming organic-inorganic hybrid infrared absorbing particles 23. It was confirmed. In addition, when the organic-inorganic hybrid infrared absorbing particles were visually checked, it was confirmed that they were light in color. Further, although the microgrid 24 is also shown in FIG. 2, this does not constitute the organic-inorganic hybrid infrared absorbing particles.
2. Manufacture of infrared absorbing fiber The obtained organic-inorganic hybrid infrared absorbing particle dispersion and a water-soluble acrylic binder resin were mixed to prepare a treatment liquid. Next, the prepared treatment liquid was impregnated with polyester fibers and dried to produce infrared absorbing fibers according to Example 1 to which organic-inorganic hybrid infrared absorbing particles were attached.
3. Production of textile products The obtained infrared absorbing fibers were cut to produce polyester staples, which were used to produce spun yarns. Then, a knit product according to Example 1 was obtained using this spun yarn. Note that the solar absorption rate of the produced knit product sample was adjusted to be around 50%. The following comparative examples were also adjusted in the same manner.
4. Evaluation of textile products The optical properties of the textile products according to Example 1 were measured by the method described above. The visible light absorption rate and solar absorption rate are: visible light absorption rate (%) = 100% - visible light transmittance (%) - visible light reflectance (%) and solar absorption rate (%) = 100% - solar radiation transmission. Calculated from ratio (%) - solar reflectance (%). The calculated visible light absorption rate and solar radiation absorption rate were 18% and 51%, respectively. Furthermore, when the color tone of the knit product was visually confirmed, it was found to be light in color.
5. Evaluation of alkali resistance The textile product according to Example 1 was immersed in a 0.01 mol/L aqueous sodium hydroxide solution maintained at 80° C. for 30 minutes to conduct an alkali resistance test. After that, the optical properties were measured again.

The visible light absorption rate and solar absorption rate after the alkali resistance test were 17% and 53%, respectively. When comparing before and after the alkali resistance test, the difference in visible light absorption rate and solar absorption rate was 1% and 2%, respectively. The evaluation results are shown in Table 1.

In other words, it was confirmed that there was no significant change in the light absorption rate of the infrared absorbing fiber before and after the alkali resistance test. Therefore, it was confirmed that the infrared absorbing fibers and textile products obtained in this example had chemical resistance properties, particularly alkali resistance properties.
[Comparative example 1]
In the dispersion liquid preparation step, a dispersion liquid containing infrared absorbing particles and a dispersion medium was prepared.

As the infrared absorbing particles, hexagonal cesium tungsten bronze (Cs _0.33 WO _z , 2.0 z≦3.0) was prepared.

Pure water was prepared as a dispersion medium.

Then, a mixed solution obtained by mixing 10% by mass of infrared absorbing particles and 90% by mass of a dispersion medium was loaded into a paint shaker containing 0.3 mmφ ZrO ₂ beads, and pulverized and dispersed for 10 hours. A dispersion of Cs _0.33 WO _z particles according to Comparative Example 1 was obtained.

Pure water as a dispersion medium was removed from the dispersion of Cs _0.33 WO _z particles obtained in the dispersion preparation step using an evaporator, and infrared absorbing particles were recovered. The collected infrared absorbing particles become dry powder of Cs _0.33 WO _z particles.

The crystallite diameter of the collected infrared absorbing particles, ie, Cs _0.33 WO _z particles, was measured and found to be 16 nm.

Note that the crystallite diameter was measured and calculated by the method described above.

Example 1 except that the dispersion of Cs _0.33 WO _z particles according to Comparative Example 1, prepared in the above dispersion preparation step, was used instead of the organic-inorganic hybrid infrared absorbing particle dispersion of Example 1. Similar operations were performed to obtain infrared absorbing fibers and textile products according to Comparative Example 1. The obtained textile product was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

以上の表１に示した繊維製品の耐アルカリ性試験前後の光学特性の評価の結果から、赤外線吸収粒子の表面の少なくとも一部に被覆用樹脂を配置した、実施例１の有機無機ハイブリッド赤外線吸収粒子を用いた繊維製品では、試験前後で光の吸収特性に大きな変化がないことを確認できた。

From the results of the evaluation of optical properties before and after the alkali resistance test of textile products shown in Table 1 above, the organic-inorganic hybrid infrared absorbing particles of Example 1 in which a coating resin was disposed on at least a part of the surface of the infrared absorbing particles It was confirmed that there was no significant change in the light absorption characteristics of textile products using this method before and after the test.

Therefore, it was confirmed that the infrared absorbing fiber using the organic-inorganic hybrid infrared absorbing particles of Example 1 and the textile products containing the infrared absorbing fiber have excellent alkali resistance, that is, chemical resistance, and excellent infrared absorption characteristics. did it. Although only an alkali resistance test was conducted here, these organic-inorganic hybrid infrared absorbing particles also have acid resistance properties because a coating resin is placed on at least a portion of the surface of the infrared absorbing particles. .

On the other hand, in the textile product using the infrared absorbing particles of Comparative Example 1, the infrared absorbing property disappeared after the alkali resistance test, and it was confirmed that the fiber product did not have alkali resistance.

Claims (11)

fiber and
organic-inorganic hybrid infrared absorbing particles;
Each of the organic-inorganic hybrid infrared absorbing particles has an infrared absorbing particle and a coating resin that includes the infrared absorbing particle,
An infrared absorbing fiber, wherein the organic-inorganic hybrid infrared absorbing particles are arranged at one or more portions selected from inside and on the surface of the fiber. The coating resin may be polyester resin, polycarbonate resin, acrylic resin, polystyrene resin, polyamide resin, vinyl chloride resin, olefin resin, fluororesin, polyvinyl acetate resin, polyurethane resin, acrylonitrile butadiene styrene resin, polyvinyl acetal resin, acrylonitrile resin, etc. Contains one or more selected from styrene copolymer resin, ethylene/vinyl acetate copolymer resin, phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyimide resin, and silicone resin. The infrared absorbing fiber according to claim 1. The infrared absorbing fiber according to claim 2, wherein the coating resin is a photocurable resin, and the photocurable resin contains a resin that is cured by irradiation with any one of ultraviolet rays, visible light, and infrared rays. The infrared absorbing particles are tungsten oxide represented by the general formula W _y O _z (W: tungsten, O: oxygen, 2.2≦z/y≦2.999), and the general formula M _x W _y O _z (Element M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn , Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf , Os, Bi, I, selected from composite tungsten oxides represented by 0.001≦x/y≦1, 2.0≦z/y≦3.0) The infrared absorbing fiber according to any one of claims 1 to 3, containing one or more types. The infrared absorbing fiber according to any one of claims 1 to 4, wherein the fiber includes one or more types selected from synthetic fibers, semi-synthetic fibers, natural fibers, regenerated fibers, and inorganic fibers. The synthetic fibers are selected from polyurethane fibers, polyamide fibers, acrylic fibers, polyester fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, and polyether ester fibers. The infrared absorbing fiber according to claim 5, containing one or more types. The infrared absorbing fiber according to claim 5 or 6, wherein the semi-synthetic fiber contains one or more types selected from cellulose fiber, protein fiber, chlorinated rubber, and hydrochloric acid rubber. The infrared absorbing fiber according to any one of claims 5 to 7, wherein the natural fiber includes one or more types selected from vegetable fiber, animal fiber, and mineral fiber. The infrared absorption according to any one of claims 5 to 8, wherein the regenerated fibers include one or more types selected from cellulose fibers, protein fibers, algin fibers, rubber fibers, chitin fibers, and mannan fibers. fiber. The infrared absorbing fiber according to any one of claims 5 to 9, wherein the inorganic fiber contains one or more types selected from metal fiber, carbon fiber, and silicate fiber. A textile product comprising the infrared absorbing fiber according to any one of claims 1 to 10.