GB2229364A - Far infrared ray emitting, odour absorbing material - Google Patents

Abstract

A far infrared ray emitting and odour absorbing material comprises one or more core materials selected from the group consisting of naturally occurring clay minerals, synthetic inorganic compounds, synthetic pigments, and synthetic or natural fibres having adhered thereto an ultrafine powder of a particle size of 500 angstrom or less and selected from alumina hydrate, silica hydrate, or when the core material is inorganic, from alumina and silica.

Description

DESCRIPTION FAR INFRARED RAY EMITTING, ODOR-ABSORBING MATERIAL This invention relates to a far infrared ray emitting, odor-absorbing material, and, more particularly, to a far infrared ray emitting, odor-absorbing material which as itself or combined with other substances can provide far infrared radiation to various objects to effect excitation vibration of water molecules in the objects and, at the same time, exhibit a superior odor-absorbing effect. The material has a wide variety of uses in the fields of drying, heating, food processing, plant growth, health promotion, and the like.

Among various far infrared ray emitting bodies, papers and woods cannot be used at a high temperature because of their ready combustibility. Metals exhibit only a small radiation activity. Ceramics which are inorganic oxides are considered as the most effective far infrared ray emitting bodies. A number of studies on ceramic far infrared ray emitting bodies have been reported, including zirconia, titania, alumina, as well as low-thermal expansion materials such as cordierite, ss-spodumene, aluminum titanate, and the like.Ceramics which are considered the most effective far infrared ray emitting bodies at the present time are oxides of transition elements such as MnO2, Fe203, CuO, CoO, and the like, or ceramics obtained by mixing these transition element oxides with Kibushi-Nendo (a clay) or petarite, as a low-thermal expansion material, and by calcining the mixture at above 1,0000C. These materials are very close to a black body exhibiting a high degree of radiation activity throughout the entire infrared range.

Various far infrared ray emitting bodies are on the market, including those mentioned above as well as naturally occurring materials. Their qualities, far infrared radiation capacities, and production costs remain, however, to be improved.

The present inventors have undertaken extensive studies to develop a far infrared ray emitting body possessing a stronger radiation capacity. The studies have been concentrated on various kinds of powders of inorganic materials, especially on their particle sizes, particle size distributions, and the effect of these factors on their far infrared radiation capacities. As a result, the inventors found that an inorganic powder emitted far infrared rays of a higher strength when the powder was more particulate and its particle size was more closely distributed. This finding has matured into a far infrared ray emitting body comprising a base material or a core material having an ultrafine inorganic powder with a closely distributed particle size adhered on said base or core material.

Further studies by the inventors revealed that alumina and silica are the most effective inorganic powders for adherence onto core materials, and that the most effective far infrared radiation could be obtained when the inorganic powders had a particle size below 500 angstrom, and preferably below 200 angstrom. That is to say, the body having an uneven, large specific surface area provides a larger radiation effect. The far infrared ray emitting body exhibited a considerable radiation capacity without a calcining process. An additional characteristic of such a far infrared ray emitting body is odor-absorbing or deodorizing effects.

Fiber products including textiles, lace, knits, nonwoven fabrics, felts, etc. are used mostly as clothing materials. Fibers are spun into strands or yarns by spinning processes, and are woven into textiles, knitted into knitting goods, packed and adhered into nonwoven fabrics, or otherwise processed to produce other fiber products.

Fibers from which textiles or yarns are prepared are called spinning and weaving fibers. Among the spinning and weaving fibers, those prepared into the closing materials are called closing fibers. Spinning and weaving fibers are broadly classified into naturals fibers, such as the fibers of vegetable, animal, or mineral origin, and synthetic fibers.

Synthetic fibers are grouped into inorganic fibers, (e.g. glass or ceramic fibers), those in the rayon family, and the synthetic fibers produced from substances derived from petroleum (e.g. nylon, polyester, acrylic fibers, etc.).

Fibers of the rayon family are of two types. One is those made from regenerated cellulose (wood pulp). Viscose and cuprammonium belong to this group. Both are derived from wood pulp dissolved in caustic soda. The other type is cellulose acetate fibers which are the reaction products (esters) of acetic acid and cellulose. Depending on the degree of acetylation cellulose acetate fibers are grouped into diacetate (usually called simply "acetate") and triacetate.

Triacetyl cellulose is produced by the reaction of acetic anhydride and cellulose. All three hydroxyl groups in glucose recurring units in cellulose are esterified by acetic acid in triacetyl cellulose. Triacetate is produced by dissolving the triacetyl cellulose into a suitable solvent, typically into a mixed solvent of methylene chloride and methanol, and by forcing the solution through sppinerets. Diacetyl cellulose is produced by adding water to triacetyl cellulose and heating the mixture to hydrolyze.

The product is dissolved into acetone and the solution is spun to produce diacetate (or acetate). Acetate fabrics are known for their brilliance of color and ability to drape well, properties that have made them particularly successful as apparel fabrics. Triacetate yarns have many of the same properties as diacetate but are particularly known for their ability to provide pleat retention in apparel. Short fibers (staples) of cellulose acetate are used as filling materials in pillows, mattress pads, and quilts and also as filtering agent of cigarettes. They are very frequently used blended with other fibers.

Different from natural fibers and synthetic fibers having round, circular cross sections, cross sections of acetate and triacetate fibers are concaved circles like leaves of clover. This makes the specific surface area of cellulose acetate fibers large.

Despite the above characteristics, cellulose acetate fibers do not possess a far infrared ray emitting, heatretaining property or a deodorizing effect which are demanded of fibers used for sanitary, health-care, or medical purposes.

The inventor found that by the combination of the above-mentioned far infrared ray emitting body and cellulose acetate fibers provides the latter with a superior far infrared ray emitting, heat-retaining characteristics as well as a superb deodorizing effect.

According to the present invention there is provided a far infrared ray emitting, odor-absorbing material, comprising: one or more core materials selected from the group consisting of naturally occurring clay minerals, synthetic inorganic compounds, synthetic pigments, and synthetic or natural fibers having adhered thereto an ultrafine powder of a particle size of 500 angstroms or less and selected from alumina hydrate, silica hydrate, and mixtures thereof, or when the core material is inorganic, from alumina oxide, silica and mixtures thereof.

Preferably the ultrafine powder has a particle size of 200 angstoms or less, e.g. a particle size of from 100-200 angstrom.

In one embodiment the ultrafine powder is chemically produced in situ in an aqueous dispersion of the core material. The ultrafine powder so produced adheres to the surface of the core material dispersed in the aqueous medium. The chemical reaction may, for example, be between a soluble material which is acidic in aqueous solution and a soluble alkali to produce particles of an insoluble reaction product which constitutes the ultrafine powder.

In another embodiment of the present invention said core material is a synthetic fiber, particularly cellulose acetate fiber.

In addition to the embodiment where the core material is cellulose acetate fibre having adhering to the surface thereof an ultrafine powder defined above, the invention also includes cellulose acetate fibre which has been filled with a particulate far infrared ray emitting material of the invention. The invention also includes yarn which comprises a far infrared ray emitting, odour absorbing material of the invention in which the core material is cellulose acetate fibre or cellulose acetate fibre filled with a particulate far infrared emitting material of the invention or a mixture of both such cellulose acetate fibres.

The core material used in this invention may be selected from a wide variety of materials. It may be a naturally occurring clay mineral such as kaolin, mica, or silicate; a synthetic inorganic compound such as alumina or silica; a synthetic pigment such as zirconia or titania; an organic material in a particle, fiber, film, or other form.

Given as more specific examples of the material which can be used as a core material in this invention are thin-layered minerals such as kaolin, vermiculite, mica, and the like; spherical particles such as spherical silica, beryllium, and the like; fibrous material such as glass fibers, ceramic fibers, carbon fibers, zeolite fibers, synthetic or natural fibers, and the like; porous material such as zeolite, diatomaceous earth, and the like; pigments, including various oxides, carbonates, sulfates, and nitrates, such as zirconia, titanium white, zinc white, barium titanate, and the like; and films such as plastic films. Depending on the application of the products of this invention synthetic or natural fibers, especially cellulose acetate fiber, are preferable as core materials.

Ultra fine inorganic particles in this invention may be formed in an aqueous dispersion of core material by adding inorganic compounds which can produce by reaction such inorganic particles.

Specifically, particles may be those of alumina hydrate or silica hydrate formed by a chemical reaction in an aqueous dispersion of core material(s). A typical example of an ultra fine particulate inorganic material is alumina hydrate produced by the reaction of aluminum chloride and ammonium hydroxide.

Other examples of such ultra fine particulate inorganic materials are silica, silicate, and the like. For example, to an aqueous solution of aluminum chloride an equivalent amount of ammonium hydroxide to neutralize the aluminum chloride is added to obtain alumina hydrate. In this instance, fine particles of the inorganic material, e.g. alumina hydrate in this case, deposit in the aqueous dispersion system.

Needle-like alumina hydrate deposits and adheres on the surfaces of the suspended core material to form a film, thus producing an ideal uneven surface with a large specific surface area which can provide a significant far infrared radiation effect.

Hydrate of alumina or silica takes the form of ultrafine particles having a size of 500 angstrom or below, usually 100 to 200 angstrom. The ultrafine particles remain unagglomerated in the dispersion and adhere on and evenly cover the surfaces of core materials to produce a reformed material with a uniform silica or alumina coat. Taking a reformed kaolin (a core material) covered with alumina hydrate, as an example, when water is eliminated and the material is dried, this material has a very uniformly aligned kaolin-alumina hydrate-kaolin structure, which can never been seen in a mere mixture of kaolin and alumina.

The material reformed by silica hydrate or alumina hydrate of this invention, if it is an inorganic material, can be calcined at a temperature above 5000C to convert the hydrate into the anhydrous oxide without impairing its effect as a far infrared ray emitting body.

The far infrared ray emitting body of this invention can be processed into compressed molded articles, films, fibers, and the like and directed to a variety of applications.

As one preferred embodiment, the present invention provides a far infrared ray emitting, odor-absorbing fibers comprising cellulose acetate fiber as an essential component. Such fiber material can be prepared by filling a particulte far infrared ray emitting inorganic material of the invention into cellulose acetate fibers.

Since cellulose acetate fibers have a clover-shaped, concaved circular cross section and have a large specific surface, there are ample spaces in the cellulose acetate fibers into which fine particles of far infrared ray emitting inorganic material can be filled. The fill-in operation can be performed by any suitable method.

A simple way of filling is to blend prescribed amounts of far infrared ray emitting particles and cellulose acetate fibers. The ratio of far infrared ray emitting particles and cellulose acetate fibers to be blended is usually 1-50 parts by weight of far infrared ray emitting particles per 100 parts by weight of cellulose acetate fibers, with a preferred range being 1-10 parts by weight of far infrared ray emitting particles per 100 parts by weight of cellulose acetate fibers.

The far infrared ray emitting, odor-absorbing fiber material of the present invention can also be prepared by using, instead of above-mentioned inorganic materials, cellulose acetate fibers as core materials in the preparation of the far infrared ray emitting inorganic material. In this instance, a proportion of ultrafine particles of hydrate of alumina or silica and cellulose acetate fibers is 1-50 parts by weight of the former per 100 parts by weight of the latter.

Another alternative method of preparing the far infrared ray emitting, odor-absorbing material of the present invention is to add cellulose acetate fibers to the aqueous dispersion of inorganic core materials in which ultrafine particles of alumina hydrate or silica hydrate is formed by a chemical reaction. A proportion of the components to be used for 100 parts by weight of cellulose acetate fibers are 1-100 parts by weight of inorganic core materials and 1-50 parts by weight of ultrafine particles of alumina hydrate or silica hydrate.

Any fibers other than cellulose acetate fibers can be used mixed with the cellulose acetate fibers of the invention.

Materials prepared according to the above procedures have ultrafine particles of alumina hydrate or silica hydrate having a large specific surface filled in cellulose acetate fibers which also have a large specific surface.

The material has excellent far infrared ray emitting, odorabsorbing effects and can expand the fields in which cellulose acetate fibers can be used.

The invention will be further illustrated by reference to the following Examples which are purely illustrative and not in any way limiting.

ExamPles Example 1 Ten (10) kg of kaolinite (UW-90, manufactured by Engelhard Minerals and Chemicals Corp.) having a specific surface of 15 m2/g was dispersed into 10 m3 of water. To this dispersion, A1C13 was added in such an amount that alumina hydrate (as A1203.3H20) of 5 kg could be produced.

To this, NH40H equivalent to neutralize A1C13 was added to ensure precipitation and adsorption of alumina hydrate of a 100 angstrom size on the surface of kaolinite. Water was removed from the product by means of a filter press, followed by drying. The dried substance was pulverized by hammer to obtain a far infrared ray emitting body.

Example 2 No. 3 water glass containing 5 kg of SiO2 was added to 10 kg of a dispersion of kaolinite prepared in the same manner as in Example 1. To this mixture HC1 in an amount equivalent to neutralize SiO2 was added to produce kaolinite having a specific surface of 250 m2/g, the surface of which was reformed by a silica film. From this material, a far infrared ray emitting body was prepared in the same manner as in Example 1.

Example 3 A far infrared ray emitting body of mica having a specific surface of 280 m2 /g, and the surface of which was reformed by alumina, was prepared in the same manner as in Example 1. In this Example mica having a specific surface of 12 m2/g (prepared by Canada Mica Co.) was used instead of kaolinite of Example 1.

Example 4 A far infrared ray emitting body was prepared in the same manner as in Example 1, except that instead of kaolinite of Example 1, TiO2 having an average particle size of 0.2 pm (Anatase-type, manufactured by Tohoku Titanium Co., Ltd.) was used. A far infrared ray emitting body having a specific surface of 25 m2/g, and the surface of which was reformed by alumina hydrate, was prepared in the same manner as in Example 1.

Example 5 A far infrared ray emitting body of polypropylene tip the surface of which was reformed by alumina was prepared in the same manner as in Example 1. In this Example polypropylene tips having a diameter of 1 mm (manufactured by OK Trading Co., Ltd.) were used instead of kaolinite of Example 1.

Comparative Example 1 To a 10% aqueous dispersion containing 10 kg of kaolinite (UW-90) 50 kg of 10% aqueous dispersion of fine particulate aluminum hydroxide having a diameter of 0.5 zm (C-3005 manufactured by Sumitomo Chemical Co., Ltd.) was added. The mixture was thoroughly stirred, and dehydrated, dried and pulverized in the same manner as in Example 1.

The pulverized material was calcined at 1,2000C for 4 hours to obtain a kaolin-alumina-type far infrared ray emitting body.

Comparative Example 2 Fine particulate aluminum hydroxide (C-3005) was used in place of alumina hydrate used in Example 4 to prepare a wet mixture of 10 kg of TiO2 and 5 kg of aluminum hydroxide.

The mixture was dehydrated, dried, pulverized, and calcined at 1,2000C for 4 hours to obtain a TiO2-A1203-type far infrared ray emitting body.

Test Example 1 An infrared radiation strength of between 2 pm and 30 jim was measured for each of the samples prepared in the above examples and in comparative examples. The measurement was carried out using an infrared spectrometer (Type A-302 manufactured by Nippon Bunkokogyo Co., Ltd.) equipped with an auxiliary photometer. The detector plotted a comparative value of each sample against a black body which was used as a standard.

Table 1 shows the mean integral value, for each sample, of the far infrared radiation strength between 5 to 15 Rm, a range having a significance in view of various applications of far infrared radiation. In the table, the relative strength at 3000C represents the relative value of each sample taking a radiation strength at 5-15 jim of the sample prepared in Example 1 as 100%.

Fifty (50) parts by weight of each product produced in the above examples and comparative examples were mixed and kneaded with 100 parts by weight of polypropylene (K-1008 manufactured by Chisso Polypropylene Co., Ltd.) and processed into plastic films. The radiation strength at 515 jim of each film was measured at 1000C according to the method described above. The results were expressed as the relative radiation strength of each film when the radiation strength at 5-15 jim measured at 1000C of the sample prepared in Example 1 was taken as 100.

Table 1 Relative Radiation Product Relative Radiation of Polypropylene Film at 3000C (%) at 1000C Example 1 100 25 Example 2 80 18 Example 3 95 22 Example 4 95 22 Example 5 - (melted) 25 Comparative Example 1 50 13 Comparative Example 2 45 10 Example 6 Ten (10) kg of silicic acid hydrate (manufactured by OK Trading Co., Ltd.) having an average particle size of 0.2 jim was dispersed into 10 m3 of water. To this dispersion, AlCl3 was added in such an amount that alumina hydrate (as A1203.3H2O) of 5 kg could be produced. To this, NH40H equivalent to neutralize A1C13 was added to ensure precipitation and adsorption of alumina hydrate of a 100 angstrom size on the surface of silicic acid hydrate.Water was removed from the product by means of a filter press, followed by drying at 1000C. The dried substance was pulverized by hammer to obtain a far infrared ray emitting body. This body was filled in cellulose acetate fiber in an amount of 3% by weight of the cellulose acetate fiber. The fiber was spun to obtain 6 denier far infrared ray emitting, odor-absorbing yarn of this invention.

Example 7 No. 3 water glass containing 3 kg of SiO2 was added to a dispersion of 10 kg of TiO2 (having an average particle size of 0.2 pm) prepared in the same manner as in Example 6.

To this mixture HC1 in an amount equivalent to neutralize SiO2 was added to produce TiO2 of which surface is reformed by SiO2. An amount of 3% by weight of this material was filled in cellulose acetate fiber in the same manner as in Example 1. The fiber was spun into 6 denier far infrared ray emitting, odor-absorbing yarn of this invention.

Example 8 Hundred (100) kg of cellulose acetate fiber was dispersed into 10 m3 of water. To this dispersion, AlCl3 was added in such an amount that alumina hydrate (as A1203.3H2O) of 3 kg could be produced. To this, NH40H equivalent to neutralize A1C13 was added to ensure precipitation and adsorption of alumina hydrate of a 50 angstrom size on the surface of cellulose acetate fiber.

Water was removed from the product by means of a filter press, followed by drying at 1000C. The dried fiber was spun into 6 denier far infrared ray emitting, odor-absorbing yarn of this invention.

Example 9 No. 3 water glass containing 3 kg of SiO2 was added to a dispersion of 100 kg of cellulose acetate fiber prepared in the same manner as in Example 8. To this mixture HC1 in an amount equivalent to neutralize SiO2 was added to produce cellulose acetate fiber of which surface is reformed by film-like SiO2. The fiber was spun into 6 denier far infrared ray emitting, odor-absorbing yarn of this invention.

Example 10 Hundred (100) kg of cellulose acetate fiber and 10 kg of silicic acid hydrate having an average particle size of 0.2 jim were dispersed into 10 m3 of water. To this dispersion, A1C13 was added in such an amount that alumina hydrate (as A1203.3H2O) of 3 kg could be produced. To this, NH40H equivalent to neutralize A1C13 was added to ensure precipitation and adsorption of alumina hydrate on the surface of cellulose acetate fiber and silicic acid hydrate.

Water was removed from the product by means of a filter press, followed by drying. The dried substance was spun to obtain 6 denier far infrared ray emitting, odor-absorbing yarn of this invention.

Example 11 The procedure of Example 10 was followed, except that AlCl3 used was such an amount that alumina hydrate (as A1203.3H2O) of 30 kg, instead of 3 kg, could be produced and the amount of NH40H used was equivalent to neutralize this A1C13 to obtain 6 denier far infrared ray emitting, odorabsorbing yarn of this invention.

Example 12 Ten (10) kg of the dried fiber before spinning prepared in Example 8 was blended with 2 kg of polyester fiber and spun into 6 denier far infrared ray emitting, odor-absorbing yarn of this invention.

Example 13 Ten (10) kg of the dried fiber before spinning prepared in Example 8 was blended with 2 kg of silk and spun into 6 denier far infrared ray emitting, odor-absorbing yarn of this invention.

Comparative Example 3 The same cellulose acetate fiber as used in Example 6, without mixing with the far infrared ray emitting body, was spun into 6 denier yarn.

Comparative Example 4 The same silicic acid hydrate and cellulose acetate fiber as used in Example 6 blended at a ratio of 3:97 and the blend was spun into 6 denier yarn.

Comparative Example 5 The far infrared ray emitting body produced in Example 6 was blended with polyester fiber at a ratio of 3:97 and the blend was spun into 6 denier yarn.

Comparative Example 6 The far infrared ray emitting body produced in Example 1 was blended with polypropylene fiber at a ratio of 3:97 and the blend was spun into 6 denier yarn.

Test Example 2 Infrared radiation and NH3 deodorizing effect were measured on the products prepared in Examples 6-13 and Comparative Examples 3-6.

Infrared radiation strength at 5-15 jim of the samples was measured according to the above-mentioned method.

Relative strength for each sample was calculated taking the radiation strength at 5-15 zm of the sample prepared in Example 6 as 100%.

The deodorizing effect of the samples was measured according to the following method.

(i) Test samples were prepared by placing the products in a dryer at 1100C for 3 hours and then allowing the dried products to cool in a desiccator.

(ii) A 12,150 ml glass container was used for ammonia absorption. A magnetic stirrer was provided at the bottom of the container for stirring NH3 gas.

(iii) A Kitazawa Gas Detector (manufactured by Kitazawa Industry Co., Ltd.) was used for measurement of NH3 gas concentrations.

(iv) An ammonia absorption test was performed as follows. A specified amount of a high concentration ammonia gas was injected to the glass container by a microsyringe.

After stirring for five minutes, the gas concentration in the container was measured by the gas detector. This procedure was repeated several times. One (1) gram of a sample was then placed in the container and the specified amount of a high concentration ammonia gas was injected to the glass container by a microsyringe in the same manner as above. After stirring for 5 minutes the ammonia concentration in the container was measured. Deodorization was calculated from the reduced concentration of ammonia gas.

The results are shown in the Table 2. Given in the table for reference is NH3 deodorization for coconut shell activated carbon.

TABLE 2 Infrared Radiation NH3 Deodorization Relative Strength (%) (5 to 15 corm) Example 6 100 50 Example 7 90 45 Example 8 120 60 Example 9 105 55 Example 10 125 65 Example 11 130 70 Example 12 110 50 Example 13 110 55 Comparative Example 3 30 20 Comparative Example 4 50 25 Comparative Example 5 60 40 Comparative Example 6 55 40 Activated carbon 37 According to the present invention, the surface of a inorganic core material such as kaolinite is reformed by the covering of ultrafine particles of alumina hydrate or silica hydrate to provide a very efficient far infrared ray emitting, odor-absorbing capability to the material, without calcining it at a high temperature of above 1,0000C. The material can be processed into various forms conforming to the use to which it is directed.The fiber product of the present invention possesses in addition to the high far infrared ray emitting and odor-absorbing capability, many characteristics inherently possessed by fibers, especially by cellulose acetate fibers. Thus, the fiber product will enormously expand the utility of cellulose acetate. The fields in which this product can be used encompasses those listed in Table 3.

Table 2 Field Expected Effects Application Examples Drying High-speed drying Paint, Ink, Powdery Energy savings Fibers, Tea, etc.

Homogeneous drying Freeze-proofing, etc.

Heating High-speed heating Gellation of polymers, Energy savings Softening of resins, Homogeneous heating Freeze-proofing, etc.

Food High-speed processing Fish meat paste, Bread, Processing Taste/flavor/freshness Meat, Fish, Vegetables, maintenance and promotion etc.

Agriculture Cell activation Pig breeding, Greenhouse Breeding Growth promotion control, Plant growth Health Environment conditioning House, Factory, Office, Medication Metabolism promotion Sauna, Rehabilitation facilities, etc.

Claims (12)

1. A far infrared ray emitting, odour-absorbing material, comprising: one or more core materials selected from the group consisting of naturally occurring clay minerals, synthetic inorganic compounds, synthetic pigments, and synthetic or natural fibres having adhered thereto an ultrafine powder of a particle size of 500 angstrom or less and selected from alumina hydrate, silica hydrate, or when the core material is inorganic from alumina oxide and silica.

2. A far infrared ray emitting, odour-absorbing material as claimed in claim 1 in which the ultrafine powder has a particle size of 200 angstrom or less.

3. A far infrared ray emitting, odour-absorbing material as claimed in claim 1 or 2 in which the ultrafine powder has a particle size of from 100 to 200 angstroms.

4. A far infrared ray emitting, odour-absorbing material, comprising: one or more core materials selected from the group consisting of naturally occurring clay minerals, synthetic inorganic compounds, synthetic pigments, and synthetic or natural fibres having adhered thereto an ultrafine powder selected from alumina hydrate, silica hydrate, and mixtures thereof which ultrafine powder is chemically produced in an aqueous dispersion of said core material and where the core material is inorganic optionally calcining the so formed material to convert the hydrate to the anhydrous oxide.

5. A far infrared ray emitting, odour-absorbing material as claimed in any of claims 1 to 4, wherein said core material is cellulose acetate fibre.

6. Cellulose acetate fibre filled with a particulate far infrared ray emitting, odour-absorbing material claimed in any of claims 1 to 4.

7. A yarn produced by spinning fibres which comprise cellulose acetate fibres claimed in claim 5 or 6 or a mixture thereof.

8. A far infrared ray emitting, odour-absorbing material as claimed in any of claims 1 to 5, substantially as hereinbefore described in any of Examples 1 to 11.

9. Cellulose acetate fibre as claimed in claim 6 substantially as hereinbefore described in Example 12.

10. A yarn as claimed in claim 7 substantially as hereinbefore described in Example 12 or 13.

core material and where the core material is inorganic optionally calcining the so formed material to convert the hydrate to the anhydrous oxide.

5. A far infrared ray emitting, odour-absorbing material as claimed in any of claims l to 4, wherein said core material is cellulose acetate fibre.

6. Cellulose acetate fibre filled with a particulate far infrared ray emitting, odour-absorbing material claimed in any of claims i to 4.

7. A yarn produced by spinning fibres which comprise cellulose acetate fibres claimed in claim 5 or 6 or a mixture thereof.

8. A far infrared ray emitting, odour-absorbing material as claimed in any of claims 1 to 5, substantially as hereinbefore described in any of Examples l to ii.

9. Cellulose acetate fibre as claimed in claim 6 substantially as hereinbefore described in Example 12.

10. A yarn as claimed in claim 7 substantially as hereinbefore described in Example 12 or 13.

10. A yarn as claimed in claim 7 substantially as hereinbefore described in Example 12 or 13.

core material and where the core material is inorganic optionally calcining the so formed material to convert the hydrate to the anhydrous oxide.

5. A far infrared ray emitting, odour-absorbing material as claimed in any of claims 1 to 4, wherein said core material is cellulose acetate fibre.

6. Cellulose acetate fibre filled with a particulate far infrared ray emitting, odour-absorbing material claimed in any of claims 1 to 4.

7. A yarn produced by spinning fibres which comprise cellulose acetate fibres claimed in claim 5 or 6 or a mixture thereof.

8. A far infrared ray emitting, odour-absorbing material as claimed in any of claims 1 to 5, substantially as hereinbefore described in any of Examples 1 to

11.

9. Cellulose acetate fibre as claimed in claim 6 substantially as hereinbefore described in Example

12.