TWI837413B - Infrared absorbing fiber, woven fabric or non-woven fabric - Google Patents

Abstract

The present invention is an infrared absorbing fiber, woven fabric or nonwoven fabric, which is an infrared absorbing fiber, woven fabric or nonwoven fabric containing an infrared absorbing pigment, and is characterized in that L ^* in the CIE1976 color space is greater than 30, and the color difference ΔE in the CIE1976 color space between the infrared absorbing fiber, woven fabric or nonwoven fabric and the infrared absorbing fiber, woven fabric or nonwoven fabric not containing the infrared absorbing pigment is less than 10.

Description

Infrared absorbing fibers, woven or nonwoven fabrics

The present invention relates to infrared absorbing fibers, woven fabrics or nonwoven fabrics.

Fiber products that absorb light and have the property of generating heat are well known. For example, infrared absorbing pigments such as carbon black have the property of generating heat by absorbing infrared rays, and by kneading them into fibers or coating them, heat-generating fibers can be obtained.

However, fibers containing carbon black as an infrared absorbing pigment have a problem of being extremely dark in color due to the black color of carbon black and being unable to be applied to designs with bright colors.

In this regard, Patent Document 1 describes an infrared absorbing fiber containing composite tungsten oxide particles represented by Cs _0.33 WO ₃ as an infrared absorbing pigment, wherein the content of the particles is 0.001 to 80% by weight relative to the solid content of the fiber.

The color tone of composite tungsten oxide is brighter than the black color of carbon black. Therefore, fiber products containing composite tungsten oxide have the advantage of greater freedom in design compared to fiber products containing carbon black. [Prior art literature] [Patent literature]

[Patent Document 1] Japanese Patent Application Publication No. 2006-132042

[Problems to be solved by the invention]

When a composite tungsten oxide, such as Cs _0.33 WO ₃ (hereinafter referred to as CsWO), is used for a fiber product that exhibits a light bluish green color that is visible under visible light and has a bright color tone, the color tone of the obtained fiber product may be changed.

Generally speaking, for heat-generating cold-proof clothing, it is not necessary to make the entire clothing with heat-generating fiber products. Only the portion of the clothing that generates heat and contributes to the cold-proof property to a greater extent should be made of heat-generating fiber products, and the other portions should be made of ordinary fiber products. In this case, when the heat-generating fiber products are used together with fiber products containing CsWO, there is a possibility that a difference in color tone occurs between the portion containing CsWO and the portion not containing CsWO, which may cause design problems. This tendency is particularly prominent when the color tone of the target clothing is particularly bright.

Furthermore, according to Patent Document 1, when the CsWO content in the infrared absorbing fiber is 0.001 to 80 wt % relative to the solid content of the fiber, a very wide range is indicated, including insufficient and excessive heat generation when used as cold-proof clothing.

The present invention was completed in view of the above-mentioned matters. Accordingly, the purpose of the present invention is to provide a fiber, woven fabric or non-woven fabric, which contains an infrared absorbing pigment and has the property of absorbing infrared rays and generating heat, and is suitable for clothing products such as cold-proof clothing, and can provide better design. [Means for solving the problem]

The present invention for solving the above-mentioned problems is as follows.

[Aspect 1] An infrared absorbing fiber, woven fabric or nonwoven fabric, which is an infrared absorbing fiber, woven fabric or nonwoven fabric containing an infrared absorbing pigment, characterized in that L ^* in the CIE1976 color space is greater than 30, and the color difference ΔE in the CIE1976 color space between the infrared absorbing fiber, woven fabric or nonwoven fabric and the infrared absorbing fiber, woven fabric or nonwoven fabric not containing the infrared absorbing pigment is less than 10. [Aspect 2] The infrared absorbing fiber, woven fabric or nonwoven fabric as described in Aspect 1, wherein the L ^* described in the CIE1976 color space is greater than 90, and at least one of the following (i) to (iv) is satisfied: (i) a ^* in the CIE1976 color space is less than -10, (ii) a ^* in the CIE1976 color space is greater than 10, (iii) b ^* in the CIE1976 color space is less than -10, and (iv) b ^* in the CIE1976 color space is greater than 10. [Aspect 3] The infrared absorbing fiber, woven fabric or nonwoven fabric as described in Aspect 1, wherein the L ^* described in the CIE1976 color space is less than 90. [Aspect 4] An infrared absorbing fiber, woven fabric or nonwoven fabric as described in any one of Aspects 1 to 3, wherein the content of the infrared absorbing pigment is 0.01 mass % to 0.50 mass % for the infrared absorbing fiber, based on the total mass of the infrared absorbing fiber, and the content of the infrared absorbing pigment per unit area of the infrared absorbing woven fabric or nonwoven fabric is 0.05 g/ ^m2 to 0.50 g/ ^m2 . [Aspect 5] An infrared absorbing fiber, woven fabric or nonwoven fabric as described in any one of aspects 1 to 4, wherein the infrared absorbing pigment comprises one or more selected from the group consisting of a complex tungsten oxide represented by general formula (1) and a tungsten oxide having a Maneli phase represented by general formula (2), general formula M _x W _y O _z (1) {In formula (1), M is one or more elements selected from the group consisting of H, He, alkali metal elements, alkali earth metal elements, rare earth elements, 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, W is tungsten, O is oxygen, x, y and z are positive numbers, 0＜x/y≦1, and 2.2≦z/y≦3.0} General formula W _y O _z (2) {In formula (2), W is tungsten, O is oxygen, y and z are positive numbers, and 2.45≦z/y≦2.999}. [Aspect 6] An infrared absorbing fiber described in any one of aspects 1 to 5. [Aspect 7] An infrared absorbing woven fabric or nonwoven fabric, which is composed of the infrared absorbing fiber described in aspect 6. [Aspect 8] An infrared absorbing woven fabric or nonwoven fabric, which is composed of the infrared absorbing fiber described in aspect 6 and a fiber that does not contain an infrared absorbing pigment, wherein the fiber that does not contain the aforementioned infrared absorbing pigment has a structure in which the aforementioned infrared absorbing pigment is removed from the aforementioned infrared absorbing fiber. [Aspect 9] An infrared absorbing woven fabric or nonwoven fabric as described in any one of aspects 1 to 5. [Aspect 10] An infrared absorbing woven fabric or nonwoven fabric as described in aspect 9, which is composed of infrared absorbing fibers containing infrared absorbing pigments. [Aspect 11] An infrared absorbing woven fabric or nonwoven fabric as described in aspect 9, which is composed of infrared absorbing fibers containing infrared absorbing pigments and fibers not containing infrared absorbing pigments, wherein the fibers not containing the aforementioned infrared absorbing pigments have a structure in which the aforementioned infrared absorbing pigments are removed from the aforementioned infrared absorbing fibers. [Aspect 12] An infrared absorbing clothing, which is composed of an infrared absorbing woven fabric or nonwoven fabric as described in any one of aspects 7 to 11. [Aspect 13] An infrared absorbing clothing, which is composed of an infrared absorbing woven fabric or nonwoven fabric as described in any one of aspects 7 to 11, and a woven fabric or nonwoven fabric that does not contain an infrared absorbing pigment, wherein the woven fabric or nonwoven fabric that does not contain the aforementioned infrared absorbing pigment has a structure in which the aforementioned infrared absorbing pigment is removed from the aforementioned infrared absorbing woven fabric or nonwoven fabric. [Effect of the invention]

The present invention provides a fiber, woven fabric or nonwoven fabric, which contains an infrared absorbing pigment and has the property of absorbing infrared rays and generating heat. When used in clothing products such as cold-proof clothing, the fiber, woven fabric or nonwoven fabric can provide better design.

The infrared absorbing fiber, woven fabric or nonwoven fabric of the present invention is an infrared absorbing fiber, woven fabric or nonwoven fabric containing an infrared absorbing pigment, and is characterized in that L ^* in the CIE1976 color space is greater than 30, and the color difference ΔE in the CIE1976 color space between the infrared absorbing fiber, woven fabric or nonwoven fabric and the infrared absorbing fiber, woven fabric or nonwoven fabric not containing the infrared absorbing pigment is less than 10.

The infrared absorbing fiber, woven fabric or nonwoven fabric of the present invention may further have an L ^* exceeding 90 in the CIE1976 color space and satisfy at least one of the following (i) to (iv): (i) a ^* in the CIE1976 color space is less than -10, (ii) a ^* in the CIE1976 color space is greater than 10, (iii) b ^* in the CIE1976 color space is less than -10, and (iv) b ^* in the CIE1976 color space is greater than 10.

The infrared absorbing fiber, woven fabric or nonwoven fabric of the present invention may be an infrared absorbing fiber, woven fabric or nonwoven fabric having an L ^* of 90 or less in the CIE1976 color space.

In this manual, the term "woven fabric" includes both fabrics (woven fabrics) and knitted fabrics (knitted fabrics). The term "nonwoven fabric" refers to a sheet of intertwined fibers and does not include the concepts of woven fabrics and knitted fabrics. In the following, fibers, woven fabrics, and nonwoven fabrics are collectively referred to as "fiber products".

In this specification, the L ^* requirement of an infrared absorbing fiber product in the CIE1976 color space is ³⁰ or more, and the color difference ΔE in the CIE1976 color space between an infrared absorbing fiber product and the infrared absorbing fiber product not containing the infrared absorbing pigment is 10 or less.

The color difference ΔE is the value expressed by the following formula when the color of the infrared absorbing fiber product in the CIE1976 color space is defined as (L ^* , a ^* , b ^* ) and the color of the infrared absorbing fiber product in the CIE1976 color space when the infrared absorbing fiber product does not contain an infrared absorbing pigment is defined as ( _L0 ^* , _a0 ^* , _b0 ^* ). ΔE={(L ^* _-L0 ^* ) ²⁺ (a ^* _-a0 ^* ) ²⁺ (b ^* _-b0 ^* ) ² } ^1/2

In order to solve the problem of the present invention, the inventors have studied in detail the relationship between the color tone of a fiber product without an infrared absorbing pigment, the amount of infrared absorbing pigment contained in the infrared absorbing fiber product, the change in the color tone of the fiber product when a specified amount of infrared absorbing pigment is contained, and the heat generation of the fiber product when a specified amount of infrared absorbing pigment is contained.

The results revealed the following: (1) For dark-colored fiber products, the color change between when infrared absorbing pigments are not included and when they are included is so small that it does not become a problem. (2) For bright-colored fiber products, especially bright-colored fiber products with low chroma, the color change caused by the inclusion of infrared absorbing pigments can be easily recognized visually compared to bright-colored fiber products with high chroma. (3) In the range where the color change is difficult to recognize, bright-colored fiber products can exert comfortable heat generation as cold-proof clothing by including infrared absorbing pigments.

The present invention is accomplished based on the above-mentioned insights.

In the infrared absorbing fiber product of the present invention, when L ^* in the CIE1976 color space is 30 or more, by including a significant amount of infrared absorbing pigment, the color tone of the fiber product is bright to the extent that the color tone change may become a problem. Accordingly, fiber products with dark colors with L ^* less than 30, in which the color tone change is difficult to recognize even if a significant amount of infrared absorbing pigment is included, are excluded from the scope of the present invention.

In the infrared absorbing fiber product of the present invention, the color difference ΔE in the CIE1976 color space between when the infrared absorbing pigment is included and when it is not included is less than 10, indicating that the fiber product contains the infrared absorbing pigment in a range where the color tone change is difficult to identify. The fiber product that meets this requirement can not only have comfortable heat generation as cold-proof clothing, but also reduce the color tone difference with the part without the infrared absorbing pigment, and thereby can exert better design.

When the brightness of the color tone of the infrared absorbing fiber product of the present invention is particularly high, by including the infrared absorbing pigment, the color tone change of the fiber product can be easily recognized visually. In view of this, when the brightness of the color tone of the fiber product is particularly high, a higher chroma is advantageous from the perspective of making it difficult to visually recognize the color tone change. Accordingly, when the brightness of the infrared absorbing fiber product of the present invention is particularly high, for example, when L ^* in the CIE1976 color space exceeds 90, it is preferably to satisfy at least one of the following requirements (i) to (iv): (i) a ^* in the CIE1976 color space is less than -10, (ii) a ^* in the CIE1976 color space is greater than 10, (iii) b ^* in the CIE1976 color space is less than -10, and (iv) b ^* in the CIE1976 color space is greater than 10.

On the other hand, when the brightness of the infrared absorbing fiber product of the present invention is not particularly high, for example, when the L ^* in the CIE1976 color space is below 90, the color tone change caused by the inclusion of the infrared absorbing pigment is not particularly easy to recognize visually. Therefore, in this case, regardless of the value of a ^* or b ^* , the present invention can be appropriately adapted.

The L ^* , a ^* , and b ^* of a fiber product in the CIE 1976 color space can be measured by the method described in the examples described below.

The present invention is described in detail below.

"Infrared absorbing fiber product" The infrared absorbing fiber product of the present invention is an infrared absorbing fiber product containing an infrared absorbing pigment, and is characterized in that L ^* in the CIE1976 color space is greater than 30, and the color difference ΔE in the CIE1976 color space between the infrared absorbing fiber product and the infrared absorbing fiber product without the infrared absorbing pigment is less than 10.

The infrared absorbing fiber product of the present invention may be an infrared absorbing fiber product having an L ^* exceeding 90 in the CIE1976 color space and satisfying at least one of the following (i) to (iv): (i) a ^* in the CIE1976 color space is less than -10, (ii) a ^* in the CIE1976 color space is greater than 10, (iii) b ^* in the CIE1976 color space is less than -10, and (iv) b ^* in the CIE1976 color space is greater than 10.

The infrared absorbing fiber product of the present invention may be an infrared absorbing fiber product having an L ^* of 90 or less in the CIE1976 color space.

The color difference ΔE between the infrared absorbing fiber product and the infrared absorbing fiber product without the aforementioned infrared absorbing pigment in the CIE1976 color space is 10 or less. If the ΔE between the two is 10 or less, it becomes difficult to visually identify the color change of the fiber product due to the inclusion of the infrared absorbing pigment. The value of ΔE may be 9 or less, 8 or less, 6 or less, 5 or less, or 4 or less. In addition, the value of ΔE may be 0 or more, more than 0, 0.5 or more, 1 or more, 2 or more, or 3 or more.

In the case of an infrared absorbing fiber product, when L ^* in the CIE1976 color space exceeds 90, that is, even if the color tone of the fiber product is particularly bright, if at least one of the above (i) to (iv) is satisfied, it becomes difficult to visually recognize that the color tone of the fiber product has changed due to the inclusion of an infrared absorbing pigment. When L ^* exceeds 90, from the perspective of difficulty in visually recognizing the change in color tone, the color difference ΔE may be 5 or less, 4.5 or less, 4 or less, 3.5 or less, or 0 or more, more than 0, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, or 0.5 or more.

However, when L ^* exceeds 90, it becomes difficult to visually identify the color change, and the content of the infrared absorbing pigment in the fiber product is limited, thereby limiting the heat generation. From this point of view, the L ^* of the infrared absorbing fiber product in the CIE1976 color space can be below 90.

This L ^* is appropriately set in the above range according to the desired color tone of the fiber product. For example, for a fiber product with a red color tone, L ^* is 90 or less, and may be 80 or less, 70 or less, 60 or less, or 50 or less. For a fiber product with a yellow color tone, L ^* is 90 or less, and may be 89 or less, 88 or less, 87 or less, or 86 or less. For a fiber product with a blue color tone, L ^* is 90 or less, and may be 80 or less, 60 or less, or 40 or less.

Even when L ^* is 90 or less, when the color tone of the fiber product is relatively bright, for example, when L ^* exceeds 80, in order to ensure the difficulty of visually recognizing the color tone change, the color difference ΔE may be set to 8 or less, 7 or less, 6 or less, or 5 or less. On the other hand, when L ^* is 80 or less, if the color difference ΔE is 10 or less, the visual recognition of the color tone change becomes extremely difficult.

<Fiber> The infrared absorbing fiber product of the present invention comprises fiber and infrared absorbing pigment.

The fiber of the infrared absorbing fiber product of the present invention can be appropriately selected from synthetic fibers, semi-synthetic fibers, natural fibers, synthetic fibers, inorganic fibers, and mixed yarns composed of multiple types thereof. In consideration of the dispersibility of the infrared absorbing pigment, the heat-retaining properties of the fiber product, etc., synthetic fibers are preferred.

Examples of the synthetic fiber in the present invention include polyester fibers, polyolefin fibers, acrylic fibers, polyamide fibers, polyether ester fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, and polyvinyl chloride fibers, and any of these fibers can be appropriately selected and used.

Polyester fibers may be, for example, polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, or the like.

Polyolefin fibers may be, for example, fibers of polyethylene, polypropylene, polystyrene, etc.

The acrylic fiber may be, for example, a fiber including polyacrylonitrile, acrylonitrile/vinyl chloride copolymer, or the like.

The polyamide-based fiber may be, for example, a fiber including nylon, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, aramid, and the like.

The fiber of the present invention may have a cross-section of any shape, such as round, polygonal, flat, hollow, Y-shaped, star-shaped, core-sheath shaped, etc.

The fiber of the present invention can be short fiber or long fiber.

<Infrared absorbing pigment> The infrared absorbing pigment of the infrared absorbing fiber product of the present invention preferably has the property of absorbing infrared rays, preferably near-infrared rays, emitting heat, and has a bright color tone, and does not excessively impair the design freedom of the infrared absorbing fiber product of the present invention.

Examples of such infrared absorbing pigments include complex tungsten oxides represented by general formula (1) and tungsten oxides having a Magniel phase represented by general formula (2). One or more of these can be appropriately selected and used. General formula M _x W _y O _z (1) {In formula (1), M is one or more elements selected from the group consisting of H, He, alkali metal elements, alkali earth metal elements, rare earth elements, 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, W is tungsten, O is oxygen, x, y and z are positive numbers, 0＜x/y≦1, and 2.2≦z/y≦3.0} General formula W _y O _z (2) {In formula (2), W is tungsten, O is oxygen, y and z are positive numbers, and 2.45≦z/y≦2.999}.

Here, the so-called alkali metal elements are the elements of Group 1 of the Periodic Table excluding hydrogen atoms. The so-called alkali earth metal elements are the elements of Group 2 of the Periodic Table excluding Be and Mg. The so-called rare earth elements are Sc, Y and yttrium elements.

The composite tungsten oxide represented by the general formula (1) contains the element M. Therefore, since free electrons are generated, the absorption band derived from the free electrons appears in the near-infrared wavelength region, and thus it is suitable as a material that absorbs near-infrared rays with a wavelength of about 1,000 nm and generates heat.

If the value of x/y, which indicates the amount of element M added, exceeds 0, the near-infrared absorption effect of generating a sufficient amount of free electrons can be fully obtained. The more the amount of element M added, the more the supply of free electrons increases. Although the near-infrared absorption effect is also increased, the value of x/y is saturated at about 1. If the value of x/y is 1 or less, it is better because the generation of an impurity phase in the layer containing microparticles can be avoided. The value of x/y is preferably 0.001 or more, 0.2 or more, or 0.30 or more. This value is preferably 0.85 or less, 0.5 or less, or 0.35 or less. The ideal value of x/y is 0.33.

In particular, when the element M in the general formula (1) is one or more of Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe and Sn, it is preferred from the viewpoint of improving the optical properties and weather resistance as a near-infrared absorbing material, and it is particularly preferred when M is Cs.

In the case of Cs _x W _y O _z (0.25≦x/y≦0.35, 2.2≦z/Y≦3.0), the lattice constant is 7.4060Å to 7.4082Å for the a-axis and 7.6106Å to 7.6149Å for the c-axis, which is better in terms of optical properties in the near-infrared region and weather resistance.

When the composite tungsten oxide represented by general formula (1) has a hexagonal crystal structure or is composed of a hexagonal crystal structure, it is preferred because it increases the transmittance of infrared absorbing material particles in the visible light wavelength region and increases the absorption in the near-infrared light wavelength region. When cations of element M are added to the gaps in the hexagonal crystal, the transmittance in the visible light wavelength region is increased and the absorption in the near-infrared light wavelength region is increased. Here, generally speaking, when an element M having a larger ion radius is added, a hexagonal crystal is formed. Specifically, when an element having a larger ion radius such as Cs, Rb, K, Tl, In, Ba, Sn, Li, Ca, Sr, Fe, etc. is added, a hexagonal crystal is easily formed. However, the present invention is not limited to these elements, and even if it is an element other than these elements, as long as the additive element M exists in the hexagonal voids formed by the WO ₆ unit.

When the composite tungsten oxide having a hexagonal crystal structure has a uniform crystal structure, the amount of the additive element M is preferably such that the value of x/y is 0.2 or more and 0.5 or less, more preferably 0.30 or more and 0.35 or less, and ideally 0.33. It is considered that when the value of x/y is 0.33, the additive element M is arranged in all the hexagonal voids.

The composite tungsten oxide represented by general formula (1) is better when treated with a silane coupling agent because of its excellent dispersibility, near-infrared absorption and transparency in the visible light wavelength region.

In tungsten oxide having a Maneli phase represented by general formula (2), the so-called "Maneli phase" having a composition ratio in which the z/y value satisfies the relationship of 2.45≦z/y≦2.999 is chemically stable and has good absorption characteristics in the near-infrared wavelength region, so it is preferably used as a near-infrared absorption material.

In general formulas (1) and (2), the value of z/y indicates the control level of the oxygen content. Since the composite tungsten oxide represented by general formula (1) satisfies the relationship of z/y of 2.2≦z/y≦3.0, in addition to the same oxygen control mechanism as the tungsten oxide represented by general formula (2), even when z/y=3.0, there is also a supply of free electrons by the addition of element M. In general formula (1), it is more preferable that the value of z/y satisfies the relationship of 2.45≦z/y≦3.0.

In addition, the raw material compounds used in the production of the composite tungsten oxide and tungsten oxide of the present invention may have a part of the oxygen atoms constituting the composite tungsten oxide and tungsten oxide replaced by halogen atoms. However, this does not cause any problem in the implementation of the present invention. Therefore, the composite tungsten oxide and tungsten oxide of the present invention also include a part of the oxygen atoms replaced by halogen atoms.

Since the infrared absorbing pigment of the present invention greatly absorbs light in the near-infrared wavelength region, especially light around 1,000 nm, its color tone often changes from blue to green. However, since the color is light, the infrared absorbing fiber product of the present invention including the infrared absorbing pigment can provide better design when applied to clothing such as cold-proof clothing.

The content of the infrared absorbing pigment in the infrared absorbing fiber product of the present invention will be described later.

<Infrared absorbing fiber> The infrared absorbing fiber product of the present invention includes infrared absorbing fiber.

Accordingly, the infrared absorbing fiber of the present invention is an infrared absorbing fiber containing an infrared absorbing pigment, and is characterized in that L ^* in the CIE1976 color space is greater than 30, and the color difference ΔE in the CIE1976 color space between the infrared absorbing fiber and the infrared absorbing fiber without the infrared absorbing pigment is less than 10.

In this specification, the color tone of a fiber can be measured when the fiber is in a state of being a plain woven or tricot warp knitted fabric.

The content of the infrared absorbing pigment in the infrared absorbing fiber of the present invention can be 0.01 mass % or more and 0.50 mass % or less based on the total mass of the infrared absorbing fiber.

The content of the infrared absorbing pigment that satisfies the ΔE requirement specified in the present invention and is suitable for achieving comfortable heat generation may be 0.01 mass % or more, 0.05 mass % or more, 0.10 mass % or more, or 0.15 mass % or less, or 0.50 mass % or less, 0.40 mass % or less, 0.30 mass % or less, or 0.20 mass % or less, based on the total mass of the infrared absorbing fiber.

<Method for producing infrared absorbing fiber> The infrared absorbing fiber of the present invention can be produced by a known appropriate method or by adding appropriate modifications thereto by a person having ordinary knowledge in the field of the present invention.

The infrared absorbing fiber of the present invention can be produced, for example, by: (1) a method of directly blending an infrared absorbing pigment into a raw polymer of a synthetic fiber and spinning the fiber; (2) a method of preparing a masterbatch in which an infrared absorbing pigment is blended at a high concentration in a raw polymer of a synthetic fiber, and then mixing the masterbatch with a diluted polymer that does not contain an infrared absorbing pigment and spinning the fiber; (3) a method of blending an infrared absorbing pigment into a doping solution containing a raw polymer of a synthetic fiber and spinning the fiber; (4) a method of attaching an infrared absorbing pigment to the surface and at least one side of the interior of a fiber that does not contain an infrared absorbing pigment, etc.

The spinning in the above-mentioned production methods (1), (2) and (3) may be wet spinning using an appropriate solvent, or may be dry spinning such as melt spinning.

The infrared absorbing fiber of the present invention may contain a coloring agent such as a suitable pigment or dye in order to express a desired color tone. The coloring agent may be added at any time point in the production process of the infrared absorbing fiber.

<Application of infrared absorbing fiber> The infrared absorbing fiber of the present invention can be applied to, for example, infrared absorbing woven fabrics or nonwoven fabrics.

The infrared absorbing woven or nonwoven fabric may be composed only of the infrared absorbing fiber of the present invention, or may be composed of the infrared absorbing fiber of the present invention and other fibers. Here, the other fibers may contain infrared absorbing pigments, but may be fibers that do not meet at least one of the L ^* requirement and the ΔE requirement specified in the present invention, or may be fibers that do not contain infrared absorbing pigments.

However, when applied to clothing products, in order to achieve the purpose of the present invention to provide better design, it is preferred to use, as other fibers, a fiber obtained by removing the infrared absorbing pigment from the infrared absorbing fiber of the present invention.

That is, the infrared absorbing woven fabric or nonwoven fabric formed using the infrared absorbing fiber of the present invention is suitable to be composed only of the infrared absorbing fiber of the present invention or composed of the infrared absorbing fiber of the present invention and a fiber having a structure in which the infrared absorbing pigment is removed from the infrared absorbing fiber.

If the infrared absorbing fiber of the present invention satisfies both the L ^* requirement and the ΔE requirement specified in the present invention, the infrared absorbing woven fabric or non-woven fabric composed of the infrared absorbing fiber of the present invention can satisfy both the L ^* requirement and the ΔE requirement specified in the present invention, or can satisfy at least one of them.

The infrared absorbing woven fabric or nonwoven fabric made of the infrared absorbing fiber of the present invention may be, for example, plain weave, satin weave, twill weave, etc.; it may also be chain stitch, single hook weave, thread weave, double crochet, semi-double crochet, slip stitch, tricot warp knitting, etc.; it may also be a nonwoven fabric manufactured by a suitable method such as dry process, wet process, spunbond process, meltblowing process, thermal bonding process, chemical bonding process, needle rolling process, spunlace process, stitch bond process, steam jet process, etc.

<Infrared absorbing woven fabric or nonwoven fabric> The infrared absorbing fiber product of the present invention includes infrared absorbing woven fabric or nonwoven fabric. Hereinafter, woven fabrics and nonwoven fabrics are collectively referred to as "woven fabrics, etc."

The infrared absorbing fabric of the present invention is an infrared absorbing fabric containing an infrared absorbing pigment, and is characterized in that L ^* in the CIE1976 color space is greater than 30, and the color difference ΔE in the CIE1976 color space between the infrared absorbing fabric and the infrared absorbing fabric without the infrared absorbing pigment is less than 10.

The content of the infrared absorbing pigment in the infrared absorbing woven fabric of the present invention may be 0.05 g/m ² or more and 0.50 g/m ² or less per unit area of the infrared absorbing woven fabric.

The content of the infrared absorbing pigment that satisfies the ΔE requirement specified in the present invention and is suitable for achieving comfortable heat generation may vary depending on the color tone of the infrared absorbing woven fabric, etc. In the case of bright warm colors, such as red and yellow woven fabrics, the L ^* value is relatively large, and the color tone change of the woven fabric, etc. due to the inclusion of the infrared absorbing pigment tends to be easily recognized by the eye. Therefore, the content of the infrared absorbing pigment that satisfies the ΔE requirement has a limit on the upper limit. In this case, the content of the infrared absorbing pigment per unit area may be 0.01 g/m ² or more, 0.03 g/m ² or more, 0.05 g/m ² or more, 0.06 g/m ² or more, 0.08 g/m ^{2 or more, 0.10 g/m 2 or} more, or 0.12 g/m ² or more in order to achieve comfortable heat generation, and may be 0.50 g/m ² or less, 0.40 g/m ² or less, 0.30 g/m ² or less, 0.25 g/m ² or less, or 0.20 g/m ² or less in order to ensure the sufficiency of the ΔE requirement.

In the case where the color tone is particularly bright, for example, the L ^* value exceeds 80 or exceeds 90, the content of the infrared absorbing pigment per unit area may be 0.30 g/ ^m2 or less, 0.25 g/ ^m2 or less, 0.20 g/ ^m2 or less, 0.15 g/m2 or less, 0.12 g/ ^m2 or less, or 0.10 g/ ^m2 or less from the viewpoint that the visual ^recognition of the color tone change becomes more difficult.

On the other hand, in the case of a darker cool color tone, such as a blue color tone of a woven fabric, the L ^* value is relatively small, and the change in color tone due to the inclusion of an infrared absorbing pigment in the woven fabric tends to be difficult to distinguish visually. Therefore, even if a relatively large amount of an infrared absorbing pigment is included, it tends to be easy to satisfy the ΔE requirement. In this case, in order to achieve comfortable heat generation, it may be above 0.05 g/m ² , above 0.06 g/m ² , above 0.08 g/m ² , above 0.10 g/m ² or above 0.12 g/m ^2. In order to ensure the sufficiency of the ΔE requirement, it may be below 0.50 g/m ² , below 0.48 g/m ² , below 0.46 g/m ² , below 0.44 g/m ² , below 0.42 g/m ² or below 0.40 g/m ² .

<Composition of infrared absorbing woven fabrics, etc.> The infrared absorbing woven fabrics, etc. of the present invention may be composed only of infrared absorbing fibers containing infrared absorbing pigments, or may be composed of infrared absorbing fibers containing infrared absorbing pigments and fibers not containing infrared absorbing pigments. Here, the fibers not containing infrared absorbing pigments may be those having a composition in which the infrared absorbing pigments are removed from the infrared absorbing fibers, or may be composed of a material different from this.

However, when applied to clothing products, in order to achieve the purpose of the present invention to provide better design, it is preferred to use a fiber having a structure in which the infrared absorbing pigment is removed from the infrared absorbing fiber as the fiber not containing the infrared absorbing pigment.

That is, the infrared absorbing woven fabric of the present invention is suitable to be composed only of infrared absorbing fibers containing infrared absorbing pigments, or composed of infrared absorbing fibers containing infrared absorbing pigments and fibers having a structure in which the infrared absorbing pigments are removed from the infrared absorbing fibers.

The infrared absorbing knitted fabric of the present invention as a whole only needs to satisfy both the L ^* requirement and the ΔE requirement specified in the present invention. The fiber constituting the infrared absorbing knitted fabric may satisfy both the L ^* requirement and the ΔE requirement specified in the present invention, or may satisfy at least one of them.

The infrared absorbing woven fabric of the present invention is made of the above-mentioned fibers, for example, it can be a plain weave, satin weave, twill weave, etc.; it can also be a chain stitch, single crochet, thread weave, double crochet, semi-double crochet, blind stitch, tricot warp knitting, etc. (knitting); it can also be a non-woven fabric made by appropriate means such as a fleece forming method (for example, dry method, wet method, spunbond method, melt-blowing method, etc.), a fleece bonding method (for example, thermal bonding method, chemical bonding method, needle rolling method, hydroentanglement method, needle-type bonding method, steam jet method, etc.).

<Method for manufacturing infrared absorbing woven fabric> The infrared absorbing woven fabric of the present invention can be manufactured by a known appropriate method, or by a method in which appropriate modifications are made by a person having ordinary knowledge in the field of the present invention.

The infrared absorbing woven fabric of the present invention can be manufactured, for example, by: (1) a method of obtaining a woven fabric by weaving infrared absorbing fibers; (2) a method of obtaining a woven fabric by weaving infrared absorbing fibers, or infrared absorbing fibers and fibers that do not contain infrared absorbing pigments; (3) a method of obtaining a nonwoven fabric by using infrared absorbing fibers, or infrared absorbing fibers and fibers that do not contain infrared absorbing pigments, by appropriate means such as a flock forming method and a flock bonding method; (4) a method of applying a coating liquid containing an infrared absorbing pigment to a woven fabric that does not contain an infrared absorbing pigment; etc.

The coating liquid used in the method (4) may contain, in addition to, for example, an infrared absorbing pigment and a suitable solvent, and may further contain a binder polymer, etc., if necessary, in order to improve the adhesion between the infrared absorbing pigment and the woven fabric.

The infrared absorbing woven fabric of the present invention may contain a coloring agent such as a suitable pigment or dye in order to express a desired color tone. The coloring agent may be applied at any time point in the manufacturing process of the infrared absorbing woven fabric. In particular, in the method (3) using a coating liquid, the coloring agent may be contained in the coating liquid.

《Infrared absorbing clothing》 The present invention further provides infrared absorbing clothing.

The infrared absorbing clothing of the present invention may include infrared absorbing woven fabrics etc. formed of the infrared absorbing fiber of the present invention, and infrared absorbing woven fabrics etc. of the present invention.

The infrared absorbing clothing of the present invention may be composed only of the infrared absorbing woven fabrics as described above, or may be composed of the infrared absorbing woven fabrics and woven fabrics that do not contain infrared absorbing pigments.

The woven fabric etc. not containing the infrared absorbing pigment may be a fabric having a structure in which the infrared absorbing pigment is removed from the infrared absorbing fabric etc., or may be a fabric composed of a material different from this.

However, in order to achieve the purpose of the present invention to provide better design, it is preferred to use a structure in which the infrared absorbing pigment is removed from the infrared absorbing woven fabric or the like as the woven fabric or the like that does not contain the infrared absorbing pigment.

That is, the infrared absorbing clothing of the present invention is suitable for being composed only of an infrared absorbing woven fabric etc. containing an infrared absorbing pigment, or being composed of an infrared absorbing woven fabric etc. containing an infrared absorbing pigment and a woven fabric etc. having a structure in which the infrared absorbing pigment is removed from the infrared absorbing woven fabric etc.

The infrared absorbing clothing of the present invention can be manufactured by a known method using the above-mentioned woven fabric, etc. [Example]

1. Infrared absorbing woven fabrics In the following examples and comparative examples, the following raw materials were used in sample preparation.

<Infrared absorbing pigment> (Tungsten cesium oxide) A dispersion containing "YMS-01A-2" manufactured by Sumitomo Metal Mining Co., Ltd., 25% by weight of Cs _0.33 WO ₃ , and propylene glycol monomethyl ether acetate as a solvent

Hereinafter, the infrared absorbing pigment Cs _0.33 WO ₃ is referred to as “CsWO”, and the dispersion containing the CsWO and a solvent is referred to as “CsWO dispersion”.

(Antimony-doped tin oxide) Ishihara Industries Co., Ltd., "ATO", solid content 100% by weight

(Carbon black) Produced by CABOT, furnace black "R400R", solid content 100% by weight

＜Binder polymer＞ Dainichi Seika Co., Ltd., urethane resin solution "RESAMINE ME-44ELPNS", solid content 30% by weight

<Color paint> Red: Seiko Advance Co., Ltd., "MRJ RX02 510 American Red", solid content 37% by weight Yellow: Seiko Advance Co., Ltd., "MRJ RX02 NC200 Primrose Yellow", solid content 37% by weight Blue: Seiko Advance Co., Ltd., "MRJ RX02 440 Blue", solid content 37% by weight White: Seiko Advance Co., Ltd., "MRJ RX02 120 White", solid content 64% by weight

《Comparative Example r1》 (1) Preparation of coating 10.0 parts by weight of red coating (equivalent to 3.70 parts by weight of solid content), 54.0 parts by weight of urethane resin solution (equivalent to 16.20 parts by weight of solid content), and 36.0 parts by weight of methyl ethyl ketone (MEK) were mixed to prepare 100 parts by weight of red base coating with a red coating content of 10% by weight (wet/wet) and a solid content of 19.9% by weight.

(2) Coating: The coating obtained above was applied to a 100% polyester white fabric (334 μm thick, L ^* 93.6, a ^* 1.9, b ^* -8.7) using a Baker coating machine at a wet film thickness of 200 μm and a coating speed of 5.2 m/min. The solvent was then removed by leaving the fabric at 100°C for 1 minute to prepare a reference fabric sample.

(3) Evaluation (3-1) Evaluation of photothermal properties A lighting eye light (model name "PRF250", rated voltage 100V, rated power consumption 250W, color temperature 3,200K, diffuse light type) manufactured by Iwasaki Electric Co., Ltd. was set at a distance of 30cm from a fabric sample cut into a 7cm×7cm square and irradiated with light. The temperature of the back side of the fabric (the temperature of the surface opposite to the surface on the light irradiated side) was measured before light irradiation (0 minutes later) and 5 minutes after light irradiation, and the photothermal properties of the fabric sample were calculated from the difference between the two.

The photothermal values of the fabric samples obtained here were used as a basis for calculating the photothermal effects of the infrared absorbing pigments in Examples R1 and R2 and Comparative Example R2.

(3-2) Evaluation of color tone Using a spectrophotometer manufactured by X-Rite, model name "SpectroEye", the L ^* , a ^* and b ^* of the fabric sample obtained above were measured in the CIE1976 color space. The measurement was performed by overlapping three sheets of white paper (L ^* = 94.84, a ^* = 0.03, b ^* = 0.44, thickness 0.24 mm) and placing them under the fabric sample.

The L ^* , a ^* , and b ^* values of the fabric sample obtained here were used as a basis for calculating the color difference ΔE in Examples R1 and R2 and Comparative Example r2.

The fabric samples obtained here were used as the basis for the sensory evaluation of the color difference in Examples R1 and R2 and Comparative Example R2.

《Example R1》 (1) Preparation of coating By adding 0.12 parts by weight of CsWO dispersion (equivalent to 0.030 parts by weight of CsWO) to 100 parts by weight of the red base coating prepared in the same manner as in Comparative Example R1, an infrared absorbing red coating having a red coating content of 10% by weight (wet/wet) and a CsWO content of 0.15% by weight per unit of coating solid component was prepared.

(2) Painting Except for using the infrared absorbing red paint obtained above, a fabric sample was prepared by painting a 100% polyester white fabric (fabric) in the same manner as in Comparative Example r1. Here, the dry weight of the painted fabric was determined from the difference in weight between the fabric sample before and after painting, and the content of the infrared absorbing pigment per unit area of the fabric sample was calculated from the amount of infrared absorbing pigment contained therein and the area of the painted surface.

(3) Evaluation (3-1) Evaluation of photothermal effect Using the obtained fabric sample of Example R1, the photothermal property and color tone were evaluated in the same manner as in Comparative Example r1. The photothermal effect of the infrared absorbing pigment in the fabric sample of Example R1 was calculated from the photothermal value of the fabric sample by reducing the photothermal value of the fabric sample of Comparative Example r1.

(3-2) Evaluation of Color Difference ΔE The color difference ΔE between the fabric sample of Example R1 and the reference of Comparative Example r1 was calculated from the L ^* , a ^* and b ^* values of the fabric sample and the L ^* , a ^* and b ^* values of the reference of the fabric sample of Comparative Example r1.

(3-3) Sensory evaluation of color difference The fabric sample obtained in this example and the standard fabric sample obtained in comparative example r1 were placed side by side on three stacked white base papers (L ^* =94.84, a ^* =0.03, b ^* =0.44, thickness 0.24 mm) and illuminated with daylight fluorescent light to investigate whether the difference in color tone between the two samples could be visually identified. The test was conducted by 6 testers and evaluated using the following criteria. A: No tester (0) could identify the difference in the color tone of the two samples (good) B: One or two testers could identify the difference in the color tone of the two samples (acceptable) C: Three or more testers could identify the difference in the color tone of the two samples (poor)

《Example R2 and Comparative Example R2》 Except for adding the amount of CsWO dispersion to 100 parts by weight of the red base coating as shown in Table 1, the same procedures as in Example R1 were followed to prepare an infrared absorbing red coating, and use it to coat and evaluate the fabric.

《Comparative Example R3》 Except for changing the usage of urethane resin solution, red paint and MEK as shown in Table 1, the rest is the same as in Comparative Example R1, and a red base paint with a red paint content of 30 wt% (wet/wet) and a solid content of 21.6 wt% is prepared, and this is used for coating and evaluation of fabrics.

The photothermal properties of the fabric samples obtained here, as well as the values of L ^* , a ^* and b ^* , were used as the basis for calculating the photothermal effect and color difference ΔE of the infrared absorbing pigment in Examples R3 and R4 and Comparative Example R4.

The fabric samples obtained here were used as the basis for the sensory evaluation of color difference in Examples R3 and R4 and Comparative Example R4.

《Example R3》 (1) Preparation of coating By adding 0.13 parts by weight of CsWO dispersion (equivalent to 0.03 parts by weight of CsWO) to 100 parts by weight of the red base coating prepared in the same manner as in Comparative Example R3, an infrared absorbing red coating having a red coating content of 30% by weight (wet/wet) and a CsWO content of 0.15% by weight per unit of coating solid component was prepared, and the coating on the fabric was performed and evaluated.

《Example R4 and Comparative Example R4》 Except that 100 parts by weight of the red base coating prepared in the same manner as in Comparative Example R3 was used as the red base coating, and the amount of CsWO dispersion added to the 100 parts by weight of the red base coating was as shown in Table 1, the same infrared absorbing red coating was prepared as in Example R3, and the fabric was coated and evaluated using the same.

The above results are shown in Table 2.

《Comparative Example y1, Examples Y1 and Y2, Examples y2 and y3, Examples Y3 and Y4, and Comparative Example y4》 Except that the same amount of yellow paint was used instead of red paint, the same yellow base paint (Comparative Examples y1 and y3) and infrared absorbing yellow paint (Examples Y1 to Y4, and Comparative Examples y2 and y4) were prepared in the same manner as Comparative Example r1, Examples R1 and R2, Comparative Examples r2 and r3, Examples R3 and R4, and Comparative Example r4, and the fabrics were coated and evaluated using these.

The photothermal properties and the values of L ^* , a ^* and b ^* of the fabric sample obtained in Comparative Example y1 were used as the basis for calculating the photothermal effect of the infrared absorbing pigment and the color difference ΔE in Examples Y1 and Y2 and Comparative Example y2. In addition, the fabric sample obtained in Comparative Example y1 was used as the basis for the sensory evaluation of the color difference in Examples Y1 and Y2 and Comparative Example y2.

The photothermal properties and the values of L ^* , a ^* and b ^* of the fabric sample obtained in Comparative Example y3 were used as the basis for calculating the photothermal effect of the infrared absorbing pigment and the color difference ΔE in Examples Y3 and Y4 and Comparative Example y4. In addition, the fabric sample obtained in Comparative Example y3 was used as the basis for the sensory evaluation of the color difference in Examples Y3 and Y4 and Comparative Example y4.

The blending of the coating materials of the above-mentioned Examples and Comparative Examples is shown in Table 3. Table 4 also shows the evaluation results of the photothermal effect and color tone (L ^* , a ^* and b ^* , and color difference ΔE) thereof.

《Comparative Example b1 and Examples B1 to B4》 Except for replacing the red paint with the same amount of blue paint, the same procedures as in Comparative Example r1, Examples R1 and R2, and Comparative Example r2 were followed to prepare a blue base paint (Comparative Example b1) and an infrared absorbing blue paint (Examples B1 to B4), and these were used for coating and evaluation of fabrics.

The photothermal properties and the values of L ^* , a ^* and b ^* of the fabric sample obtained in Comparative Example b1 were used as the basis for calculating the photothermal effect of the infrared absorbing pigment and the color difference ΔE in Examples B1 to B4. In addition, the fabric sample obtained in Comparative Example b1 was used as the basis for the sensory evaluation of the color difference in Examples B1 to B4.

The blending of the coating materials of the above-mentioned Examples and Comparative Examples is shown in Table 5. Table 6 also shows the evaluation results of the photothermal effect and color tone (L ^* , a ^* and b ^* , and color difference ΔE) thereof.

《Example R5》 Except that 0.24 weight parts of antimony-doped tin oxide (manufactured by Ishihara Industry Co., Ltd., "ATO", solid content 100 weight%) was added to 100 weight parts of the red base coating prepared in the same manner as in Comparative Example R1 as an infrared absorbing pigment, and an infrared absorbing red coating having a red coating content of 10 weight% (wet/wet) and an ATO content of 1.19 weight% per unit of coating solid content was prepared, and this was used, the coating and evaluation of the fabric were performed in the same manner as in Example R1.

《Comparative Example R5》 Except that 0.03 weight parts of carbon black (CB) (produced by CABOT, furnace black "R400R", solid content 100 weight%) was added to 100 weight parts of the red base paint prepared in the same manner as in Comparative Example R1 as an infrared absorbing pigment, and an infrared absorbing red paint having a red paint content of 10 weight% (wet/wet) and a CB content of 0.15 weight% per unit of paint solid content was prepared, and this was used, the fabric was painted and evaluated in the same manner as in Example R1.

In the evaluation of these Examples and Comparative Examples, the fabric sample obtained in Comparative Example r1 was used as the fabric sample used as the reference for photothermal properties, color difference ΔE, and sensory evaluation.

The coating material blends of the above-mentioned Examples and Comparative Examples are shown together with the blends of Comparative Example r1 in Table 7. The evaluation results of the photothermal effects and color tones (L ^* , a ^* and b ^* , and color difference ΔE) are shown together with the evaluation results of Comparative Example r1 in Table 8.

《Comparative Examples p1-p3 and Examples P1-P3》 Except for changing the usage of each color coating, urethane resin solution, MEK and CsWO dispersion to those shown in Table 9, the other procedures were the same as those of Comparative Example r1 and Example R1. The base coatings of each color (Comparative Examples p1-p3) and infrared absorbing coatings of each color (Examples P1-P3) were prepared and used for coating and evaluation of fabrics.

In these evaluations, as the fabric samples set as the basis for the photoluminescence, color difference ΔE and sensory evaluation, the sample of Comparative Example P1 was used for the sample of Example P1, the sample of Comparative Example P2 was used for the sample of Example P2, and the sample of Comparative Example P3 was used for the sample of Example P3. The obtained results are shown in Table 10.

2. Infrared absorbing fiber In the following examples and comparative examples, tests were conducted on tricot warp knitted or woven fabrics made using infrared absorbing fibers containing infrared absorbing pigments. CsWO was used as the infrared absorbing pigment, and the content in the fiber was set at two levels of 0.11 wt% and 0.52 wt%, and infrared absorbing fibers based on polyethylene terephthalate (PET) were prepared for the test.

In the following Examples and Comparative Examples, the following raw materials were used for sample preparation.

<Infrared absorbing pigment> (Tungsten cesium oxide) Dispersible powder containing Sumitomo Metal Mining Co., Ltd.'s "YMDS-874", 23% by weight of Cs _0.33 WO ₃ and a dispersant

Hereinafter, the infrared absorbing pigment Cs _0.33 WO ₃ is referred to as "CsWO", and the dispersion powder containing the CsWO and a dispersant is referred to as "CsWO dispersion powder".

<Base resin> Contains "Bell Pet IP121B" manufactured by Bell Polyester Products, isophthalic acid copolymerized polyethylene terephthalate as the third component, intrinsic viscosity = 0.62

<Preparation of CsWO masterbatch> In a double-screw extruder, 95 parts by weight of base resin and 5 parts by weight of CsWO dispersion powder (equivalent to 1.15 parts by weight of CsWO) were mixed to obtain a CsWO masterbatch containing 1.15% by weight of CsWO.

《Comparative Example t1》 (1) Spinning By using a multifilament melt spinning device, Homo PET was used as the spinning material, and the spinning was performed for 1 hour at a spinning temperature of 290°C, an extrusion rate of 4 kg/h, and a winding speed of 1,500 m/min to obtain a multifilament fiber of 50 denier and 24 filaments.

(2) Fabric Production 80 wt% of the above multifilament fiber and 20 wt% of polyurethane fiber were used to produce a 32 gauge warp knitted fabric with a unit weight of 240 g/ ^m2 by a knitting machine.

(3) Evaluation (3-1) Evaluation of photothermal properties A lighting eye light (model name "PRF250", rated voltage 100V, rated power consumption 250W, color temperature 3,200K, diffuse light type) manufactured by Iwasaki Electric Co., Ltd. was placed 30cm away from a sample of Tricot warp knitted fabric cut into a 7cm×7cm square and irradiated with light. The surface temperature of the Tricot warp knitted fabric was measured before (0 minutes after) and after 5 minutes of irradiation, and the photothermal properties of the Tricot warp knitted fabric sample were calculated from the difference between the two.

The photothermal values of the Tricot warp knitted fabric samples obtained here were used as a basis for calculating the photothermal effect of the infrared absorbing pigment in Example T1 and Comparative Example t2.

(3-2) Evaluation of color tone Using a spectrophotometer manufactured by X-Rite, model name "SpectroEye", the L ^* , a ^* and b ^* of the above-obtained Tricot warp knitted fabric sample were measured in the CIE1976 color space. The measurement was performed by overlapping three sheets of white paper (L ^* = 94.84, a ^* = 0.03, b ^* = 0.44, thickness 0.24 mm) and placing them under the Tricot warp knitted fabric sample.

The values of L ^* , a ^* , and b ^* of the Tricot warp knitted fabric sample obtained here were used as the basis for calculating the color difference ΔE in Example T1 and Comparative Example t2.

《Example T1》 (1) Spinning Except for using 9.57 parts by weight of CsWO masterbatch and 90.43 parts by weight of Homo PET as spinning raw materials, the same procedures as in Comparative Example t1 were followed to obtain an infrared absorbing multifilament fiber containing 0.11% by weight of CsWO.

(2) Fabric Preparation Infrared absorbing Tricot warp knitted fabric was prepared in the same manner as in Comparative Example t1 except that 80 wt% of the above-mentioned infrared absorbing multifilament fiber and 20 wt% of polyurethane fiber were used. The CsWO content of the infrared absorbing Tricot warp knitted fabric was 0.19 g/m ² .

(3) Evaluation The evaluation was carried out in the same manner as in comparative example t1 except that the obtained infrared absorbing Tricot warp knitted fabric was used.

《Comparative Example t2》 Except that 45.25 parts by weight of CsWO masterbatch and 54.75 parts by weight of Homo PET were used as spinning raw materials, the other procedures were the same as those of Comparative Example t1, and an infrared absorbing multifilament fiber containing 0.52% by weight of CsWO was obtained. Using the obtained infrared absorbing multifilament fiber, infrared absorbing Tricot warp knitted fabric was produced and evaluated in the same manner as in Example T1.

Table 11 shows the evaluation results of the photothermal effect and color tone (L ^* , a ^* and b ^* , and color difference ΔE) of the above-mentioned Examples and Comparative Examples.

《Comparative Example c1》 (1) Spinning By using a multifilament melt spinning device, Homo PET was used as the spinning material, and the spinning temperature was 290℃, the extrusion amount was 4kg/h, and the winding speed was 1,500m/min. The spinning was carried out for 1 hour to obtain a 75 denier 24-filament multifilament fiber. By twisting two of these multifilament fibers, a double yarn equivalent to 150 denier was obtained.

(2) Fabric Production: The obtained double yarn was set as the weft, and the polyester/wool blended yarn (250 denier) with a weight ratio of 50:50 was set as the warp. The weight ratio of the weft:warp was set to 41:59. A Jonchel type weaving machine was used to perform 3/1 twill weaving to obtain a fabric with a unit weight of 170 g/ ^m2 .

(3) Evaluation The fabric obtained here is a 3/1 twill woven fabric, with the warp side where the polyester/wool blended yarn is mostly exposed, and the weft side where the double yarn is mostly exposed. Therefore, the evaluation of the heat generation and color tone of the fabric sample was performed on both the warp side and the weft side.

(3-1) Evaluation of photothermal properties A lighting eye light (model name "PRF250", rated voltage 100V, rated power consumption 250W, color temperature 3,200K, diffuse light type) manufactured by Iwasaki Electric Co., Ltd. was set 30cm away from a fabric sample cut into a 7cm×7cm square and irradiated with light. The temperature of the back side of the fabric was measured before irradiation (0 minutes later) and 5 minutes after irradiation, and the photothermal properties of the fabric sample were calculated from the difference between the two.

The photo-heat radiance values of the fabric sample obtained here are used as the basis for calculating the photo-heat radiance effect of the infrared absorbing fabric in Example C1 and Comparative Example C2, respectively, for the warp plane and the weft plane.

(3-2) Evaluation of color tone Using a spectrophotometer manufactured by X-Rite, model name "SpectroEye", the L ^* , a ^* and b ^* of the fabric sample obtained above were measured in the CIE1976 color space. The measurement was performed by overlapping three sheets of white paper (L ^* = 94.84, a ^* = 0.03, b ^* = 0.44, thickness 0.24 mm) and placing them under the fabric sample.

The L ^* , a ^* , and b ^* values of the fabric sample obtained here were used as the basis for calculating the color difference ΔE in Example C1 and Comparative Example C2 for the warp plane and the weft plane, respectively.

《Example C1》 (1) Spinning Except for using 9.57 parts by weight of CsWO masterbatch and 90.43 parts by weight of Homo PET as spinning materials, the same procedures as in Comparative Example C1 were followed to obtain a 75 denier 24-filament infrared absorbing multifilament fiber containing 0.11% by weight of CsWO. By twisting two strands of this infrared absorbing multifilament fiber, an infrared absorbing double yarn equivalent to 150 denier was obtained.

(2) Fabric Preparation The same procedures as in Comparative Example C1 were followed except that the infrared absorbing double yarn obtained above was used as the weft yarn to obtain an infrared absorbing fabric having a unit weight of 170 g/m ^2. The CsWO content of the infrared absorbing fabric was 0.08 g/m ² .

(3) Evaluation The obtained infrared absorbing fabric was evaluated in the same manner as in comparative example c1.

Comparative Example C2: Except for using 45.25 parts by weight of CsWO masterbatch and 54.75 parts by weight of Homo PET as spinning raw materials, the same process as in Comparative Example C1 was carried out to obtain an infrared absorbing multifilament fiber containing 0.52% by weight of CsWO. Except for using the obtained infrared absorbing multifilament fiber, the same process as in Example C1 was carried out to prepare an infrared absorbing double yarn, and this was used to obtain an infrared absorbing fabric with a unit weight of 170 g/ ^m2 . The CsWO content of this infrared absorbing fabric was 0.35 g/ ^m2 .

This infrared absorbing fabric was evaluated in the same manner as in Comparative Example c1.

Table 12 shows the evaluation results of the photothermal effect and color tone (L ^* , a ^* and b ^* , and color difference ΔE) of the above-mentioned Examples and Comparative Examples.

Claims (10)

An infrared absorbing woven fabric or nonwoven fabric comprising an infrared absorbing pigment, wherein the infrared absorbing pigment comprises at least one selected from the group consisting of a composite tungsten oxide represented by general formula (1) and a tungsten oxide having a Magniel phase represented by general formula (2), wherein the general formula is M _x W _y O _z (1) {wherein, M is one or more elements selected from the group consisting of H, He, alkali metal elements, alkali earth metal elements, rare earth elements, 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 , W is tungsten, O is oxygen, x, y and z are positive numbers, 0<x/y≦1, and 2.2≦z/y≦3.0} General formula WyOz (2) {wherein W is tungsten, O is oxygen, y and z are positive numbers, and 2.45≦z/y≦2.999} L ^* in the CIE1976 color space is 30 or more, and the color difference ΔE in the CIE1976 color space between the infrared absorbing woven or nonwoven fabric and the infrared absorbing woven or nonwoven fabric not containing the infrared absorbing pigment is 10 or less. An infrared absorbing woven or nonwoven fabric as claimed in claim 1, wherein the aforementioned L ^* in the CIE 1976 color space is greater than 90 and satisfies at least one of the following (i) to (iv): (i) a ^* in the CIE 1976 color space is less than -10, (ii) a ^* in the CIE 1976 color space is greater than 10, (iii) b ^* in the CIE 1976 color space is less than -10, and (iv) b ^* in the CIE 1976 color space is greater than 10. An infrared absorbing woven or nonwoven fabric as claimed in claim 1, wherein the L ^* in the CIE 1976 color space is less than 90. The infrared absorbing woven or nonwoven fabric of claim 1, wherein the content of the infrared absorbing pigment is not less than 0.05 g/ ^m2 and not more than 0.5 g/ ^m2 per unit area of the infrared absorbing woven or nonwoven fabric. The infrared absorbing woven or nonwoven fabric of claim 2, wherein the content of the infrared absorbing pigment is not less than 0.05 g/ ^m2 and not more than 0.5 g/ ^m2 per unit area of the infrared absorbing woven or nonwoven fabric. The infrared absorbing woven or nonwoven fabric of claim 3, wherein the content of the infrared absorbing pigment is not less than 0.05 g/ ^m2 and not more than 0.5 g/ ^m2 per unit area of the infrared absorbing woven or nonwoven fabric. The infrared absorbing woven fabric or non-woven fabric as claimed in any one of claim items 1 to 6 is composed of infrared absorbing fibers containing infrared absorbing pigments. The infrared absorbing woven fabric or nonwoven fabric of any one of claim items 1 to 6 is composed of infrared absorbing fibers containing infrared absorbing pigments and fibers not containing infrared absorbing pigments, and the fibers not containing the aforementioned infrared absorbing pigments have a structure in which the aforementioned infrared absorbing pigments are removed from the aforementioned infrared absorbing fibers. An infrared absorbing clothing, which is composed of an infrared absorbing woven fabric or non-woven fabric as described in any one of claim items 1 to 8. An infrared absorbing clothing, which is composed of an infrared absorbing woven fabric or non-woven fabric described in any one of claims 1 to 8, and a woven fabric or non-woven fabric that does not contain an infrared absorbing pigment, wherein the woven fabric or non-woven fabric that does not contain the aforementioned infrared absorbing pigment has a structure in which the aforementioned infrared absorbing pigment is removed from the aforementioned infrared absorbing woven fabric or non-woven fabric.