JP2013241710A - Purified polysaccharide fiber, fiber-rubber composite and tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a purified polysaccharide fiber excellent in strength, manufactured by a method with a high resource utilization rate; a fiber-rubber composite using the purified polysaccharide fiber; and a tire excellent in tire properties using the same.SOLUTION: The purified polysaccharide fiber of the present invention is a purified polysaccharide fiber obtained in that a polysaccharide solution dissolving a polysaccharide material in a liquid comprising a polar solvent or an ionic liquid is contacted with a solidifying liquid, followed by wet spinning or dry-wet spinning the polysaccharide, where a main component is composed of two or more kinds of polysaccharides comprising a first main component and where the first main component ratio in all the components constituting the purified polysaccharide fiber is 97 wt.% or less.

Description

  The present invention relates to a purified polysaccharide fiber, a fiber-rubber composite, and a tire.

Cellulose fibers have advantages such as good dimensional stability, high adhesiveness, and low temperature dependency of elastic modulus (elastic modulus change with respect to temperature change), and are widely used as viscose rayon in tires.
However, viscose rayon emits carbon disulfide in the manufacturing process and has a very high environmental impact, so it does not meet the current needs of manufacturing products with raw materials with low environmental impact.

The characteristics such as good dimensional stability, high adhesion, and low temperature dependence of elastic modulus largely depend on the fiber material being cellulose. Synthetic fibers such as polyester and nylon are also used as tire reinforcing cords, but it is difficult to obtain dimensional stability, adhesion, and elastic modulus comparable to those of cellulose fibers.
Accordingly, viscose rayon is currently used for some tires despite the high environmental load.

In recent years when environmental preservation of the earth is screamed, it is desired to use cellulose that does not depend on fossil fuels as a raw material. The necessity of using carbon disulfide, which has a high environmental impact in the production of viscose rayon, which is the above-mentioned problem, is to melt or dissolve the cellulose when it is fiberized (spun).
In order to melt or dissolve the cellulose raw material, it is necessary to break hydrogen bonds in and between the hydroxyl groups at three positions per one repeating unit of cellulose. In the production of viscose rayon, the hydroxyl raw material can be chemically modified with carbon disulfide to break hydrogen bonds, so that the cellulose raw material can be melted or dissolved. Thus, the cellulose fiber which spun by chemically modifying the hydroxyl group and then regenerated the hydroxyl group is generally called regenerated cellulose.

In a tire, the refined cellulose fiber is generally used as a fiber-rubber composite by twisting the refined cellulose fiber into a cord and coating it with rubber after the adhesion treatment. In industrial fibers, it is necessary to have high strength. In particular, fibers used in tires are mainly intended to reinforce rubber, so that the strength is preferably high. The higher the strength of the fiber, the more the amount of fiber used in the tire can be reduced. As a result, the tire weight and rolling resistance can be reduced.
Furthermore, since the amount of fiber used can be reduced, substances and energy required for tire production can be reduced.

A high-purity dissolving pulp is used as a raw material for the purified cellulose fiber. High purity dissolving pulp is produced by refining wood chips. The components contained in the wood are composed of 40 to 60% by weight of cellulose, 10 to 30% by weight of hemicellulose, and 15 to 30% by weight of lignin, depending on the type of wood.
Since refined cellulose fibers tend to be strongly reduced when a large amount of hemicellulose component is contained, high-purity dissolving pulp is produced by purifying wood chips and removing lignin and hemicellulose. The proportion of the cellulose component in the dissolving pulp is 98% by weight or more.

  Furthermore, when producing viscose rayon using the viscose method, the molecular weight is drastically reduced in the process of dissolving the cellulose, and the fiber strength tends to be difficult to obtain. Therefore, in order to ensure high strength, it is necessary to use a material that does not contain a low molecular weight component and has a cellulose component ratio of 98% by weight or more.

  On the other hand, it has been reported that several types of ionic liquids efficiently dissolve cellulose raw materials (see Patent Documents 1 to 3). Dissolution of the cellulose raw material by the ionic liquid is due to solvation and does not discharge harmful substances such as carbon disulfide in the production process of the purified cellulose fiber. Since the production of the purified cellulose fiber is easily achieved by passing the dissolved cellulose raw material through water, alcohol, or an aqueous solution of water and an ionic liquid, the cellulose molecular weight decreases in dissolving the cellulose with the ionic liquid. Can be suppressed (see Patent Documents 4 to 5).

U.S. Pat. No. 1,943,176 JP 60-144322 A Japanese Patent No. 4242768 US Patent Application Publication No. 2008/0269477 Chinese Patent No. 101382626 Specification

A large amount of chemicals and energy are used for refining a high purity dissolving pulp having a cellulose component ratio of 98% by weight or more, and there is a problem of wastewater treatment.
Moreover, when only cellulose is used for a fiber, it is clear that it is not effective utilization of resources. If hemicellulose can also be used for the fiber, most of the wood components can be used. Therefore, chemicals and energy necessary for purification can be saved, and resource saving can be achieved.

  The present invention has been made in view of the above circumstances, and is produced by a highly resource-efficient method, and is a highly excellent purified polysaccharide fiber, a fiber-rubber composite using the purified polysaccharide fiber, and It aims at providing the tire excellent in the tire characteristic using it.

［式中、Ｒ^１は、炭素数１〜４のアルキル基、又は炭素数２〜４のアルケニル基を示し、Ｒ^２は、水素原子又はメチル基を示し、Ｒ^３は、炭素数１〜８のアルキル基、又は炭素数２〜８のアルケニル基を示す。］
（１１）前記アニオン部がリン原子を含む化合物を有する（９）又は（１０）の精製多糖類繊維。
（１２）前記リン原子を含む化合物が、下記一般式（Ｃ２）で表されるホスフィネートイオン、ホスフェートイオン、及びホスホネイトイオンのいずれかである（１１）の精製多糖類繊維。

［式中、Ｘ^１及びＸ^２はそれぞれ独立して、水素原子、水酸基又は炭素数が１〜４のアルコキシ基を示す。］
（１３）強力ＴＢが５．１ｃＮ／ｄｔｅｘ以上である（１）〜（１２）のいずれか一つの精製多糖類繊維。
（１４）強力ＴＢが５．４ｃＮ／ｄｔｅｘ以上である（１）〜（１３）のいずれか一つのいずれかの精製多糖類繊維。
（１５）（１）〜（１４）のいずれかの精製多糖類繊維と、ゴム材料とを複合化してなることを特徴とする繊維−ゴム複合体。
（１６）（１５）の繊維−ゴム複合体を用いたことを特徴とするタイヤ。
（１７）前記繊維−ゴム複合体をカーカスプライ、ベルトプライ、又はベルト保護層として用いた（１６）のタイヤ。 The present invention provides a purified polysaccharide fiber, a fiber-rubber composite, and a tire having the following characteristics.
(1) A purified polysaccharide fiber obtained by bringing a polysaccharide solution obtained by dissolving a polysaccharide raw material into a liquid containing a polar solvent or an ionic liquid into contact with a solidified liquid and spinning the polysaccharide wet or dry. The main component is composed of two or more kinds of polysaccharides including the first main component, and the ratio of the first main component in all the components constituting the purified polysaccharide fiber is 97% by weight or less. Purified polysaccharide fiber characterized by that.
(2) The purified polysaccharide fiber according to (1), wherein a ratio of the first main component in all components constituting the purified polysaccharide fiber is 90% by weight or less.
(3) The purified polysaccharide fiber according to (1) or (2), wherein the ratio of the polysaccharide fiber obtained from the polysaccharide raw material is 60% by weight or more.
(4) The purified polysaccharide fiber according to any one of (1) to (3), wherein the main component is cellulose and hemicellulose.
(5) The purified polysaccharide fiber according to any one of (1) to (4), wherein a ratio of the main component in all components constituting the purified polysaccharide fiber is 90% by weight or more.
(6) The purified polysaccharide fiber according to (4) or (5), wherein a proportion of the hemicellulose in all components constituting the purified polysaccharide fiber is 0.1 to 40% by weight.
(7) The purified polysaccharide fiber according to any one of (1) to (6), wherein the polar solvent is a dipole molecule or a zwitterionic molecule.
(8) The purified polysaccharide fiber according to any one of (1) to (7), wherein the polar solvent is N-methylmorpholine-N-oxide.
(9) The ionic liquid is composed of a cation portion and an anion portion, and the cation portion is at least one selected from the group consisting of an imidazolium ion, a pyridinium ion, an ammonium ion, and a phosphonium ion. 6) The purified polysaccharide fiber according to any one of 6).
(10) The purified polysaccharide fiber according to (9), wherein the cation moiety is an imidazolium ion represented by the following general formula (C1).

[Wherein, R ¹ represents an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, R ² represents a hydrogen atom or a methyl group, and R ³ represents 1 to 8 carbon atoms. Or an alkenyl group having 2 to 8 carbon atoms. ]
(11) The purified polysaccharide fiber according to (9) or (10), wherein the anion moiety has a compound containing a phosphorus atom.
(12) The purified polysaccharide fiber according to (11), wherein the compound containing a phosphorus atom is any one of a phosphinate ion, a phosphate ion, and a phosphonate ion represented by the following general formula (C2).

[Wherein, X ¹ and X ² each independently represent a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 4 carbon atoms. ]
(13) The purified polysaccharide fiber according to any one of (1) to (12), wherein the strong TB is 5.1 cN / dtex or more.
(14) The purified polysaccharide fiber according to any one of (1) to (13), wherein the strong TB is 5.4 cN / dtex or more.
(15) A fiber-rubber composite comprising the purified polysaccharide fiber according to any one of (1) to (14) and a rubber material.
(16) A tire using the fiber-rubber composite of (15).
(17) The tire according to (16), wherein the fiber-rubber composite is used as a carcass ply, a belt ply, or a belt protective layer.

According to the present invention, the purified polysaccharide fiber can be produced by a method with a high resource utilization rate, and therefore, the environmental load can be reduced.
Moreover, since the refined polysaccharide fiber and rubber-fiber composite of the present invention are excellent in strength, they have high utility value.
Furthermore, since the tire of the present invention uses the rubber-fiber composite of the present invention, it has good tire performance.

[Purified polysaccharide fiber]
The purified polysaccharide fiber of the present invention is obtained by bringing a polysaccharide solution obtained by dissolving a polysaccharide raw material into a liquid containing a polar solvent or an ionic liquid, and bringing the polysaccharide into contact with the solidified liquid to wet-spin or dry-wet the polysaccharide. The main component which consists of 2 or more types of polysaccharide containing a 1st main component is contained, and the ratio of the said 1st main component in all the components which comprise the said refined polysaccharide fiber is 97 weight% or less.
Different types of polysaccharides means that the types of monosaccharides constituting the polysaccharides are different.
In the present invention, the main component is a component contained in the purified polysaccharide fiber in an amount of 1.0% by weight or more. In each component constituting the main component, the first main component and the second main component in descending order of the component ratio. It is called the main component.

  Examples of polysaccharides in polysaccharide raw materials (raw materials containing polysaccharides) used in the present invention include cellulose; cellulose derivatives such as ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, nitrocellulose, and cationized cellulose; Carrageenans such as κ-carrageenan, ι-carrageenan and λ-carrageenan; guar gum; locust bean gum; pectin; tragacanth; corn starch; phosphorylated starch; xanthan gum and dextrin It is done.

  Moreover, chitin is mentioned as a polysaccharide in a polysaccharide raw material. Chitin may be natural chitin or regenerated chitin, and examples of natural chitin include those contained in shells of shellfish such as insects, shrimps and crabs, and plants such as mushrooms.

In the present invention, the cellulose raw material is not particularly limited as long as it contains cellulose, and may be a plant-derived cellulose raw material, an animal-derived cellulose raw material, or a microorganism-derived cellulose raw material. Or a regenerated cellulose raw material.
Plant-derived cellulose raw materials include cellulose raw materials derived from unprocessed natural plants such as wood, cotton, hemp and other herbs, rice straw, bagasse, pulp, wood powder, wood chips, paper products, etc. The plant-derived processed cellulose raw material which gave the process is mentioned.
Examples of natural plants include conifers, hardwoods, monocotyledons, dicotyledons and bamboo.
Examples of animal-derived cellulose raw materials include squirt-derived cellulose raw materials.
Examples of the cellulose raw material derived from microorganisms include those produced by the raw materials of microorganisms belonging to the genus Aerobacter, Acetobacter, Achromobacter, Agrobacterium, Alacaligenes, Azotobacter, Pseudomonas, Rhizobium, Sarcina, etc.
Examples of the regenerated cellulose raw material include a cellulose raw material obtained by regenerating a cellulose raw material derived from plants, animals, or microorganisms as described above by a known method such as a viscose method.
Especially, as a cellulose raw material in this invention, the pulp which melt | dissolves favorably in a polar solvent or an ionic liquid is preferable.

  The dissolving pulp is preferably obtained by refining wood chips. The components contained in the wood are composed of 40 to 60% by weight of cellulose, 10 to 30% by weight of hemicellulose, and 15 to 30% by weight of lignin, depending on the type of wood.

The main component of the purified polysaccharide fiber of the present invention is composed of two or more kinds of polysaccharides. As a raw material of such purified polysaccharide fiber, a polysaccharide raw material containing two or more kinds of polysaccharides may be used, or a plurality of polysaccharide raw materials containing one kind of polysaccharide may be used.
The combination of polysaccharides is not particularly limited and is appropriately selected from those described above. A combination of cellulose and hemicellulose is preferable, and the first main component is more preferably cellulose.
In the present invention, the ratio of the first main component in all components constituting the purified polysaccharide fiber is 97% by weight or less, and preferably 90% by weight or less.

  When the main component of the purified polysaccharide fiber of the present invention is a combination of cellulose and hemicellulose, the strength of the fiber tends to be reduced by including the hemicellulose component. From the viewpoint of suppressing the decrease in strength, the total ratio of cellulose and hemicellulose is preferably 90% by weight or more in all components constituting the purified polysaccharide fiber.

From the viewpoint of resource saving, the ratio of the purified polysaccharide fiber of the present invention obtained from the polysaccharide raw material (hereinafter referred to as resource utilization rate) is preferably 60% by weight or more, and preferably 70% by weight or more. More preferably, it is particularly preferably 80% by weight or more.
For example, 60 g or more of the purified polysaccharide fiber of the present invention can be obtained from 100 g of pulp.
When producing a purified cellulose fiber as the purified polysaccharide fiber of the present invention, it becomes clear that a high strength fiber can be obtained even if the proportion of the cellulose component in all the components constituting the purified cellulose fiber is not 98% by weight or more. It was. Therefore, according to the present invention, the resource utilization rate can be increased.

  From the viewpoint of balance between strength and resource utilization in the purified polysaccharide fiber, the proportion of hemicellulose is preferably 0.1 to 40% by weight in all components constituting the purified polysaccharide fiber, and 0.1 to 20%. More preferably, it is% by weight.

  In the present invention, before a polysaccharide raw material containing cellulose or the like is dissolved in a polar solvent or a liquid containing an ionic liquid, the polysaccharide raw material can be pretreated for the purpose of improving the solubility in the ionic liquid. Specifically, the pretreatment may include a drying treatment, a physical pulverization treatment such as pulverization and grinding, a chemical modification treatment using an acid or an alkali, and the like. Any of these can be performed by a conventional method.

In the present invention, the polar solvent to be used is preferably one having a capability of solvating and dissolving in polysaccharides, particularly cellulose which is hardly soluble among polysaccharides.
Among them, a solvent having a high polarizability is considered to have a high ability to solvate. The degree of polarization is μ≈0 for neutral apolar molecules (cyclohexane, etc.), whereas μ = 3-6 for dipolar molecules (N-methylmorpholine-N-oxide, etc.), and μ> 10 for zwitterionic molecules. Here, μ represents a dipole moment.
The polar solvent is preferably a dipole molecule or a zwitterionic molecule, more preferably N-methylmorpholine-N-oxide (NMMO).

  In the present invention, the ionic liquid refers to a solvent that is liquid at 100 ° C. or lower and is composed only of ions, and the cation part or the anion part or both are composed of organic ions.

The ionic liquid is composed of a cation portion and an anion portion, and the cation portion of the ionic liquid is not particularly limited, and those generally used for the cation portion of the ionic liquid can be used.
Especially, as a preferable thing of the cation part of the ionic liquid of this invention, a nitrogen-containing aromatic ion, an ammonium ion, and a phosphonium ion are mentioned.

Specific examples of the nitrogen-containing aromatic cation include pyridinium ion, pyridazinium ion, pyrimidinium ion, pyrazinium ion, imidazolium ion, pyrazonium ion, oxazolium ion, 1,2,3-triazoli. Umum ion, 1,2,4-triazolium ion, thiazolium ion, piperidinium ion, pyrrolidinium ion and the like.
Especially, as a nitrogen-containing aromatic cation, an imidazolium ion and a pyrimidinium ion are preferable, and an imidazolium ion represented by the following general formula (C3) is more preferable.

［式中、Ｒ^６〜Ｒ^７は、それぞれ独立に、炭素数１〜１０のアルキル基、又は炭素数２〜１０のアルケニル基であり、Ｒ^８〜Ｒ^１０は、それぞれ独立に、水素原子、又は炭素数１〜１０のアルキル基である。］

[Wherein R ^{6 to} R ⁷ are each independently an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and R ^{8 to} R ¹⁰ are each independently a hydrogen atom, Or it is a C1-C10 alkyl group. ]

In formula (C3), R ^{6 to} R ⁷ are each independently an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms.
The alkyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, preferably linear or branched, and more preferably linear. .
Specific examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
Specific examples of the branched alkyl group include 1-methylethyl group, 1,1-dimethylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1,1-dimethylpropyl group, 2, Examples thereof include 2-dimethylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
The cyclic alkyl group may be a monocyclic group or a polycyclic group. Specific examples include monocyclic groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; and polycyclic groups such as norbornyl group, adamantyl group, and isobornyl group.
The number of carbon atoms of the alkyl group in R ⁶ to R ⁷ is preferably 1-8.
Examples of the alkenyl group having 2 to 10 carbon atoms include an alkyl group having 2 to 10 carbon atoms in which one carbon-carbon single bond is substituted with a double bond. Preferred examples include a vinyl group, Examples include allyl group. The position of the double bond is not particularly limited.
It is preferable that the carbon number of the alkenyl group in R < ⁶ > -R < ⁷ > is 2-8.
R ^{6 to} R ⁷ may be the same or different from each other.

In formula (C3), R ^{8 to} R ¹⁰ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.
The alkyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, preferably linear or branched, and more preferably linear. . Here, examples of the linear, branched, and cyclic alkyl groups include the same alkyl groups as those described above for R ^{6 to} R ⁷ .
The number of carbon atoms of the alkyl group in R ^{8 to} R ¹⁰ is preferably 1 to 6, more preferably 1 to 3, and most preferably R ^{8 to} R ¹⁰ is a hydrogen atom.
R ^{8 to} R ¹⁰ may be the same or different from each other.

  A preferred specific example of the imidazolium ion represented by the formula (C3) is shown as the following formula (C1).

［式中、Ｒ^１は、炭素数１〜４のアルキル基、又は炭素数２〜４のアルケニル基を示し、Ｒ^２は、水素原子又はメチル基を示し、Ｒ^３は、炭素数１〜８のアルキル基、又は炭素数２〜８のアルケニル基を示す。］

[Wherein, R ¹ represents an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, R ² represents a hydrogen atom or a methyl group, and R ³ represents 1 to 8 carbon atoms. Or an alkenyl group having 2 to 8 carbon atoms. ]

  Moreover, the preferable specific example of the imidazolium ion represented by Formula (C1) is shown as following formula (C1-1)-(C1-3).

The phosphonium ion is not particularly limited as long as it has “P ⁺ ”. Specifically, the phosphonium ion is preferably a general formula “R ₄ P ⁺ (a plurality of R are independently hydrogen atoms). It is an atom or a hydrocarbon group having 1 to 30 carbon atoms.) ”.
The hydrocarbon group having 1 to 30 carbon atoms may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
The aliphatic hydrocarbon group is preferably a saturated hydrocarbon group (alkyl group), and the alkyl group may be linear, branched, or cyclic.
The linear alkyl group preferably has 1 to 20 carbon atoms, and more preferably 1 to 16 carbon atoms. Specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, A hexadecyl group etc. are mentioned.
The branched alkyl group has 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms, and more preferably 3 to 16 carbon atoms. Specifically, 1-methylethyl group, 1,1-dimethylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1,1-dimethylpropyl group, 2,2-dimethylpropyl group, 1-methylbutyl Group, 2-methylbutyl group, 3-methylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
The cyclic alkyl group has 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms, more preferably 3 to 16 carbon atoms, and even a monocyclic group, It may be a polycyclic group. Specific examples include monocyclic groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group, and polycyclic groups such as norbornyl group, adamantyl group, and isobornyl group.
The aromatic hydrocarbon group preferably has 6 to 30 carbon atoms. Specifically, an aryl group such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a biphenyl group, a tolyl group, or a benzyl group And arylalkyl groups such as a phenethyl group, a naphthylmethyl group, and a naphthylethyl group.
Here, the plurality of R in the general formula “R ₄ P ⁺ ” may be the same or different.

  Especially, as a phosphonium ion, the cation part represented by a following formula (C4) is preferable.

［式中、Ｒ^１１〜Ｒ^１４は、それぞれ独立に、炭素数１〜１６のアルキル基である。］

[In formula, R < ¹¹ > -R < ¹⁴ > is a C1-C16 alkyl group each independently. ]

In formula (C4), R ^{11 to} R ¹⁴ are each independently an alkyl group having 1 to 16 carbon atoms. The alkyl group having 1 to 16 carbon atoms may be linear, branched or cyclic, preferably linear or branched, and more preferably linear. . Here, examples of the linear, branched, and cyclic alkyl groups include those described above.
R ^{11 to} R ¹⁴ may be the same or different from each other, but it is preferable that three or more of R ^{11 to} R ¹⁴ are the same from the viewpoint of availability.

Among these, in the present invention, the alkyl group of R ^{11 to} R ¹⁴ is preferably a linear or branched alkyl group having 1 to 14 carbon atoms, and is a linear or branched chain group having 1 to 10 carbon atoms. Are more preferable, linear or branched alkyl groups having 1 to 8 carbon atoms are more preferable, and linear or branched alkyl groups having 1 to 4 carbon atoms are particularly preferable.
A preferred specific example of the cation moiety represented by the formula (C4) is shown as the following formula (C5).

  In the present invention, the cation moiety is more preferably one or more selected from the group consisting of an imidazolium ion, a pyridinium ion, an ammonium ion, and a phosphonium ion.

In the present invention, examples of the anion moiety include a halogen ion, a carboxylate ion, a phosphinate ion, a phosphate ion, and a phosphonate ion.
Examples of the halogen ion include chloride ion, bromide ion, and iodide ion, and chloride ion is preferable.
Examples of carboxylate ions include formate ion, acetate ion, propionate ion, butyrate ion, hexanoate ion, maleate ion, fumarate ion, oxalate ion, rectate ion, and pyruvate ion. Formate ion, acetate ion and propionate ion are preferable.
Especially, it is preferable that an anion part has a compound containing a phosphorus atom, and it is more preferable that it is any of the phosphinate ion, phosphate ion, and phosphonate ion represented by the following general formula (C2).

［式中、Ｘ^１及びＸ^２はそれぞれ独立して、水素原子、水酸基又は炭素数が１〜４のアルコキシ基を示す。］
ホスフェートイオンとしては、下記一般式（Ａ１）で表されるものが挙げられる。

[Wherein, X ¹ and X ² each independently represent a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 4 carbon atoms. ]
As a phosphate ion, what is represented by the following general formula (A1) is mentioned.

［式中、Ｒ^１５及びＲ^１６はそれぞれ独立に水素原子、又はアルキル基である。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents a hydrogen atom or an alkyl group. ]

In the formula (A1), R ¹⁵ and R ¹⁶ are each independently a hydrogen atom or an alkyl group, and the alkyl group may be any of linear, branched, and cyclic. It is preferably a linear or branched alkyl group. The carbon number of the alkyl group of R ¹⁵ and R ¹⁶ is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 4, and 1 carbon atom for industrial reasons. Or an alkyl group of 2 is particularly preferred.
R ¹⁵ and R ¹⁶ may be the same or different.

  Of these phosphate ions, dimethyl phosphate ions and diethyl phosphate ions are preferred.

  Examples of the phosphonate ion include those represented by the following general formula (A2).

［式中、Ｒ^１５は上記と同様である。］

[Wherein, R ¹⁵ is the same as defined above. ]

Wherein ^{(A2), R 15} is the same as ^{R 15} in the formula (A1).

  Of these phosphonate ions, methyl phosphonate ions are preferred.

  The phosphinate ion is represented by the following formula (A3).

The ionic liquid having a compound in which the anion portion contains a phosphorus atom has a lower viscosity and melting point than when the anion portion is a halogen ion. For this reason, it is excellent in that it is easy to spin cellulose using the ionic liquid.
In addition, an ionic liquid having a compound in which the anion portion contains a phosphorus atom is less likely to decrease the molecular weight of the fiber and has higher heat resistance than the case where the anion portion is a carboxylate ion (that is, thermal decomposition at a high temperature). Hard to do). For this reason, the spinning temperature can be increased when the polysaccharide is spun using the ionic liquid. As a result, the productivity of the purified polysaccharide fiber at a higher spinning temperature can be ensured. For example, when the anion moiety is a carboxylate ion, the productivity of spinning the polysaccharide is lowered under the condition that the spinning temperature is 130 ° C. or higher. However, when the anion portion is a compound containing a phosphorus atom, the productivity of polysaccharide spinning can be maintained even under a high heat condition where the spinning temperature is 150 ° C.

Furthermore, when the ionic liquid having a compound in which the anion moiety contains a phosphorus atom is reused, the reuse yield is high. Generally, when manufacturing refined polysaccharide fiber industrially, the ionic liquid which flows out when the solution is made into fiber by passing it through a solidified liquid is recycled. The ionic liquid is recycled by distillation or the like by volatilizing liquid components other than the ionic liquid. At that time, since heat is applied to the ionic liquid, it is important that the ionic liquid has thermal stability, and the thermal stability of the ionic liquid affects the yield of recycling.
Therefore, by using a compound containing a phosphorus atom as the anion part, it is possible to prevent an increase in the amount of ionic liquid necessary for continuously producing purified polysaccharide fibers, substances necessary for the production of ionic liquid, and energy. .

  In addition, pseudohalogen ions may be mentioned as other anion moieties. Pseudohalogen ions have properties similar to those of halogen ions. Examples of pseudohalogen ions include cyanate ions, oxocyanate ions, thiocyanate ions, and selenocyanate ions.

The ionic liquid in the present invention is composed of a cation portion and an anion portion as described above. The combination of a cation part and an anion part is not specifically limited, The thing which can melt | dissolve a cellulose raw material suitably can be selected suitably.
Preferred ionic liquids include 1-allyl-3-methylimidazolium chloride (AmimCl), 1-ethyl-3-methylimidazolium acetate (C2mimAc), 1-ethyl-3-methylimidazolium diethylphosphate (C2mimDEP), 1 -Ethyl-3-methylimidazolium methylphosphonate (C2mimM EP), 1-butyl-3-methylimidazolium acetate (C4mimAc), 1-ethyl-3-methylimidazolium phosphinate (C2mim HPO) and the like.
By the polysaccharide dissolution method using an ionic liquid described later, an ionic liquid having a small decrease in the molecular weight of the polysaccharide was clarified.
From the viewpoint of suppressing the decrease in molecular weight of the polysaccharide in the fiber, 1-ethyl-3-methylimidazolium acetate (C2mimAc), 1-ethyl-3-methylimidazolium diethylphosphate (C2mimDEP), 1-ethyl-3-methyl Imidazolium methylphosphonate (C2mimMEP) and 1-ethyl-3-methylimidazolium phosphinate (C2mim HPO) are more preferred, and 1-ethyl-3-methylimidazolium diethylphosphate (C2mimDEP) is particularly preferred.

  The viscosity of the ionic liquid is preferably lower. When an ionic liquid having a high viscosity is used, it is difficult to dissolve the polysaccharide raw material in the ionic liquid. When it is difficult to dissolve the polysaccharide raw material, a large amount of undissolved polysaccharide raw material is produced, and the filter is clogged during spinning. As a result, productivity decreases. Moreover, when the above-mentioned undissolved polysaccharide raw material is mixed in the fiber, it becomes a fracture core of the fiber. As a result, the quality of the fiber decreases. On the other hand, when an ionic liquid having a low viscosity is used, when the polysaccharide raw material is dissolved in the ionic liquid, the polysaccharide raw material penetrates well into the ionic liquid. For this reason, the polysaccharide can be easily dissolved in the ionic liquid.

  In this invention, although the usage-amount of an ionic liquid is not specifically limited, As a density | concentration of a polysaccharide raw material, it is preferable that it is 3-30 mass%, and it is more preferable that it is 5-25 mass%. When the polysaccharide concentration is too low, there are many ionic liquids that are removed during the solidification process, and it is difficult to form dense fibers and it is difficult to exert strength. On the other hand, when the polysaccharide concentration is too high, the polysaccharide cannot be completely dissolved.

  In the present invention, the liquid for dissolving the polysaccharide raw material contains the ionic liquid. The liquid may or may not contain liquid components other than the ionic liquid. Specific examples of liquid components other than the ionic liquid include organic solvents.

The organic solvent is not particularly limited as long as it is other than the ionic liquid, and can be appropriately selected in consideration of compatibility with the ionic liquid, viscosity, and the like.
Among these, the organic solvent is preferably at least one selected from the group consisting of amide solvents, sulfoxide solvents, nitrile solvents, cyclic ether solvents, and aromatic amine solvents.

Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone, 1-vinyl-2-pyrrolidone and the like.
Examples of the sulfoxide solvent include dimethyl sulfoxide and hexamethylene sulfoxide.
Examples of nitrile solvents include acetonitrile, propionitrile, benzonitrile and the like.
Examples of the cyclic ether solvent include 1,3-dioxolane, tetrahydrofuran, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, 1,3,5-trioxane and the like.
Examples of the aromatic amine solvent include pyridine.

When these organic solvents are used, the blending mass ratio between the ionic liquid and the organic solvent is preferably 6: 1 to 0.1: 1, and more preferably 5: 1 to 0.2: 1. More preferably, it is 4: 1 to 0.5: 1. By setting it as the said range, it can be set as the solvent which a polysaccharide raw material tends to swell.
Moreover, the usage-amount of an organic solvent is although it does not specifically limit, It is preferable that it is 1-30 mass parts with respect to 1 mass part of polysaccharide raw materials, and it is preferable that it is 1-25 mass parts. More preferably, it is -20 mass parts. By setting it as the said range, it can be set as the polysaccharide solution of moderate viscosity.
It is preferable to use the organic solvent as described above in combination with the ionic liquid because the solubility of the polysaccharide raw material is further improved.

In the present invention, the method for dissolving the polysaccharide raw material in the liquid containing the ionic liquid is not particularly limited. For example, the liquid containing the ionic liquid and the polysaccharide raw material are contacted and heated as necessary. A polysaccharide solution can be obtained by stirring or stirring.
The method for bringing the liquid containing the ionic liquid into contact with the polysaccharide raw material is not particularly limited. For example, the polysaccharide raw material may be added to the liquid containing the ionic liquid, or the ionic liquid may be added to the cellulose raw material. A liquid containing it may be added.
When heating is performed during dissolution, the heating temperature is preferably 30 to 200 ° C, more preferably 70 to 180 ° C. It is preferable to perform heating because the solubility of the polysaccharide raw material is further improved.
The stirring method is not particularly limited, and the liquid containing the ionic liquid and the polysaccharide raw material may be mechanically stirred using a stirrer, a stirring blade, a stirring rod, etc., and the liquid containing the ionic liquid And the polysaccharide raw material may be sealed in a sealed container and stirred by shaking the container. Further, the liquid containing the ionic liquid and the polysaccharide raw material may be dissolved by an extruder or a kneader having a single axis or a plurality of axes. The stirring time is not particularly limited, and it is preferable to carry out the stirring until the polysaccharide raw material is suitably dissolved.

In addition, when the liquid containing the ionic liquid contains an organic solvent in addition to the ionic liquid, the organic solvent and the ionic liquid may be mixed in advance, and after mixing the ionic liquid and the polysaccharide raw material, A solvent may be added and dissolved, or after mixing an organic solvent and a cellulose raw material, an ionic liquid may be added and dissolved.
Especially, it is preferable to mix an organic solvent and an ionic liquid beforehand, and to manufacture a liquid mixture. At this time, it is preferable to stir while heating at 70 to 180 ° C. for about 5 to 30 minutes so that the organic solvent and the ionic liquid are uniformly mixed, and to mix until the liquid containing the ionic liquid becomes uniform. .

The polysaccharide dissolution method using the ionic liquid described above has a drawback that it is poor in versatility because the viscosity of the ionic liquid is very high.
The present inventors have solved the problem due to the high viscosity of the ionic liquid used by diluting the obtained polysaccharide solution with a lithium complex salt solution using a halogen ion as the anion of the ionic liquid. I found.
According to such a method, the ionic liquid can dissolve many of the polysaccharides. In order to dissolve cellulose in an ionic liquid as a polysaccharide, it may be contacted at 80 to 110 ° C. for about 2 to 8 hours. More preferably, it is about 3 to 5 hours at 80 to 90 ° C.

  Next, the obtained polysaccharide solution is diluted with a lithium complex salt solution. Thereby, the polysaccharide hydrated by the ionic liquid forms a complex with lithium and becomes soluble in the solvent. As a result, since dilution is possible only by standing and shaking, the work is simplified and shortened. Moreover, according to this polysaccharide dissolving method, the amount of ionic liquid used can be reduced to 1/100 or less of the conventional method, which is excellent in terms of cost.

  The cation of the ionic liquid preferably has the imidazolium skeleton described above. Specific examples of the cation having an imidazolium skeleton include 1-ethyl-3-methylimidazolium ion, 1-n-propyl-3-methylimidazolium ion, 1-n-butyl-3-methylimidazolium ion, 1 -N-pentyl-3-methylimidazolium ion, 1-n-hexyl-3-methylimidazolium ion, 1-n-octyl-3-methylimidazolium ion, 1-ethyl-2,3-dimethylimidazolium ion More preferred are ionic liquid cations having a methylimidazolium skeleton such as 1-n-butyl-2,3-dimethylimidazolium ion, 1-allyl-3-methylimidazolium, and the like. 3-methylimidazolium ion is particularly preferred.

  Moreover, as the anion of the ionic liquid, halogen ions such as fluoride ion, chloride ion, bromide ion and iodide ion are preferable, and chloride ion is more preferable.

  As a combination of these anions and cations, 1-n-butyl-3-methylimidazolium chloride is preferable. Further, it is preferably used as a mixed solution of 1-n-butyl-3-methylimidazolium chloride and dimethylacetamide. Thereby, the viscosity of an ionic liquid can be reduced and solubility can be improved. In consideration of the solubility of polysaccharides, particularly cellulose, in the ionic liquid, the amount of dimethylacetamide in the mixed solution is preferably 25 to 50% by mass.

  The lithium complex salt in the lithium complex salt solution used for diluting the polysaccharide solution is preferably a lithium halide such as lithium fluoride, lithium chloride, lithium bromide, or lithium iodide. This is because the ionic liquid in which the polysaccharide is dissolved is substituted by the lithium complex salt, and is dissolved by the interaction of the lithium ion-polysaccharide hydroxyl group. Among these, lithium chloride is more preferable.

  As a solvent for the lithium complex salt solution, a solvent that forms a complex with lithium ions and can dissolve the polysaccharide by interaction with the polysaccharide hydroxyl group can be used, and dimethylacetamide is preferable. The lithium complex salt concentration of the lithium complex salt solution is preferably 0.5 to 10% by mass.

The polysaccharide solution obtained as described above is brought into contact with a solidifying liquid that is a liquid other than the polysaccharide solution to solidify the polysaccharide, and then the polysaccharide is obtained by the above-described dry-wet spinning or wet spinning. Can be spun.
The spinning method of the wet spinning or the dry wet spinning is not particularly limited, and the polysaccharide can be spun by a known spinning method.
Dry-wet spinning is a method of spinning a polysaccharide by introducing a polysaccharide solution once discharged into a gas from a spinneret into a solidification tank that holds a solidified liquid. Spinning is a method of spinning a polysaccharide discharged from a spinneret disposed in a solidification tank.
A solidification tank means the bathtub by which the said solidification liquid for solidifying a polysaccharide was hold | maintained. As the solidified liquid, one or more selected from the group consisting of water, a polar solvent, and the ionic liquid described above are preferably exemplified.
Examples of the polar solvent include tetrahydrofuran, acetone, acetonitrile, N, N-dimethylformamide, dimethyl sulfoxide, acetic acid, 1-butanol, 2-propanol, 1-propanol, ethanol, methanol, formic acid and the like.

As described above, since the purified polysaccharide fiber of the present invention is obtained using a liquid containing a polar solvent or an ionic liquid, it is produced without chemical reaction as in the viscose method. Therefore, the physical properties of the fibers are not adversely affected in the manufacturing process. Therefore, the purified polysaccharide fiber of the present invention maintains high strength.
In addition, since the ionic liquid is superior in solubility to the polar solvent, the purified polysaccharide fiber obtained using the ionic liquid is a uniform fiber and further maintains high strength.
The strength TB of the purified polysaccharide fiber thus obtained is preferably 5.1 cN / dtex or more, and more preferably 5.4 cN / dtex or more.

A high-performance tire can be obtained by using such a rubber-fiber composite using purified polysaccharide fibers having excellent strength for a carcass ply, a belt ply, or a belt protective layer. Especially, it is preferable to use the rubber-fiber composite of the present invention for a carcass ply, and a tire excellent in pressure resistance and side cut resistance can be obtained.
Further, a rubber-fiber composite may be used for at least one of the carcass ply, the belt ply, and the belt protective layer, but it can also be used for both the carcass ply, the belt ply, and the belt protective layer.

  As the cord produced from the polysaccharide fiber, a single twisted structure composed of a single filament bundle added with a twist, and a double twist structure obtained by combining two twisted filament bundles with an upper twist are adopted. The fineness per cord is preferably 1400 to 6000 dtex, more preferably 1400 to 4000 dtex. When a cord of less than 1400 dtex is used, it is necessary to increase the number of carcass in order to maintain tire strength, leading to an increase in tire manufacturing costs. If a cord exceeding 6000 dtex is used, the thickness of the carcass layer will increase more than necessary, leading to an increase in tire weight.

The twist coefficient of the cord is preferably 0.30 to 0.80, and more preferably 0.50 to 0.70.
The twist coefficient tanθ is obtained by the following equation.

Ｄ：総デシテック数
Ｐ：コード比重
Ｔ：撚り数（回／ｃｍ）

D: Total decitec number P: Cord specific gravity T: Number of twists (times / cm)

[Fiber-Rubber Composite]
The purified polysaccharide fiber is immersed in a general adhesive such as RFL (resolvin-formalin-latex), dipped, and subjected to heat treatment including a drying step and a baking step. The dip cord thus produced is combined with a rubber material such as a coating rubber to produce a fiber-rubber composite.

The rubber used in the rubber-fiber composite of the present invention is obtained from, for example, natural rubber (NR), synthetic rubber having a carbon-carbon double bond, or a rubber composition obtained by blending two or more of these.
Examples of the synthetic rubber include polyisoprene rubber (IR), polybutadiene rubber (BR), polychloroprene rubber which are homopolymers of conjugated diene compounds such as isoprene, butadiene and chloroprene; the conjugated diene compound and styrene and acrylonitrile. Styrene butadiene copolymer rubber (SBR), vinyl pyridine butadiene styrene copolymer rubber, acrylonitrile butadiene copolymer rubber, which are copolymers with vinyl compounds such as vinyl pyridine, acrylic acid, methacrylic acid, alkyl acrylates, alkyl methacrylates, etc. , Acrylic butadiene copolymer rubber, methacrylic acid butadiene copolymer rubber, methyl acrylate butadiene copolymer rubber, methyl methacrylate butadiene copolymer rubber, etc .; ethylene, propylene, isobutylene Copolymers of olefins and diene compounds such as isobutylene isoprene copolymer rubber (IIR); Copolymers of olefins and non-conjugated dienes (EPDM) [eg ethylene-propylene-cyclopentadiene terpolymer Polymer, ethylene-propylene-5-ethylidene-2-norbornene terpolymer, ethylene-propylene-1,4-hexadiene terpolymer]; and further, halides of these various rubbers such as chlorinated isobutylene isoprene copolymer Examples thereof include ring-opening polymers of norbornene such as polymer rubber (Cl-IIR) and brominated isobutylene isoprene copolymer rubber (Br-IIR).
Polyalkenamers obtained by ring-opening polymerization of cycloolefins to the above synthetic rubbers (for example, polypentenamers), rubbers obtained by ring-opening polymerization of oxirane rings (for example, polyepichlorohydrin rubbers capable of sulfur vulcanization), polypropylene oxide rubbers, etc. The saturated elastic body can be blended.

In the rubber composition used in the present invention, sulfur, an organic sulfur compound, and other crosslinking agents are added to 100 parts by mass of the rubber component, preferably 0.01 to 10 parts by mass, more preferably 1 to 5 parts by mass. The vulcanization accelerator may be blended with 100 parts by mass of the rubber component, preferably 0.01 to 10 parts by mass, more preferably 0.5 to 5 parts. In this case, although the kind of vulcanization accelerator is not limited, the vulcanization time can be shortened by using dibenzothiazyl sulfide (DM), diphenylguanidine (D) or the like.
The rubber composition used in the present invention includes, for example, paraffinic, naphthenic, aromatic process oil, ethylene-α-olefin co-oligomer, paraffin wax, liquid paraffin, and other mineral oils; castor oil, cottonseed oil, linseed Oils such as oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil and other vegetable oils may be blended.
Further, according to the conventional method, the rubber composition used in the present invention includes fillers such as carbon black, silica, calcium carbonate, calcium sulfate, clay, mica, etc .; zinc white, stearic acid, etc. Vulcanization accelerating aids; compounding agents usually used in the rubber industry such as anti-aging agents may be added.

  The tire of the present invention can be produced by using the rubber-fiber composite of the present invention and passing through normal molding and vulcanization processes.

  EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited to a following example.

[Production of multifilament]
The polysaccharide was refine | purified from the raw material (raw material containing polysaccharide) of Tables 1-2. Cellulose and hemicellulose were purified by the Kraft method. Chitin was purified by decalcifying crustacean exoskeletons such as crabs with hydrochloric acid and deproteinizing with alkali.
The polysaccharides purified from the raw materials listed in Tables 1 and 2 were converted into 1-ethyl-3-methylimidazolium acetate (C2AmimAc), 1-allyl-3-methylimidazolium chloride (AminCl), 1-ethyl-3- Methylimidazolium diethyl phosphate (C2mimDEP), 1-ethyl-3-methylimidazolium phosphinate (C2mim HPO), 1-ethyl-3-methylimidazolium methylphosphonate (C2mimM EP), N-methylmorpholine-N-oxide It was dissolved in a mixed solution of (NMMO) or methyltributylphosphonium chloride (MBP Cl) and dimethylacetamide (DMAc) to obtain a polysaccharide solution. After heating this polysaccharide solution to the spinning temperature, it was extruded into a solidification bath with an extruder, and after washing and drying, the multifilaments of Examples 1 to 11 and Comparative Example 1 shown in Tables 1 and 2 ( Fiber).

  The properties of the multifilament (fiber) in each Example and Comparative Example were measured by the following test methods, and the results are shown in Tables 1-2. Moreover, the weight% of each component in the multifilament (fiber) in each Example and a comparative example is shown to Tables 1-2.

(1) Fineness 100 m of fiber was collected and dried at 130 ° C. for 30 minutes, and then allowed to cool to room temperature in a dried desiccator, and then the weight was measured. Since 1 g per 10000 m is 1 dtex, the fineness was calculated from the weight of 100 m.

(2) Tensile strength and cut elongation Tensile tests were performed on fibers subjected to false twisting 4 times per 10 cm under conditions of 25 ° C. and 55% RH using a tensile tester. The strength is the breaking strength divided by the fineness, and the cut elongation is the elongation at break.

(3) Resource utilization rate In the multifilaments (fibers) of Examples 1 to 11 and Comparative Example 1, when the raw material was 100, the weight of the obtained fiber was defined as the resource utilization rate.

[Cord production]
After the obtained multifilament was twisted, two of the multifilaments were combined and twisted to prepare a cord. Tables 1 and 2 show the number of lower twists and upper twists.

[Production of dip code]
The cord was immersed in an RFL (resolcin-formalin-latex) adhesive, dip-treated, and subjected to a heat treatment including a drying step and a baking step. The drying step was performed at a tension of 1 × 10 ⁻³ N / dtex at 150 ° C. for 150 seconds. The baking process was performed following the drying process at the same temperature, the same time, and the same tension as the drying process to prepare a dip code.

[Production of carcass ply material]
The dip cord was calendared with a coating rubber to prepare a carcass ply material.

[Production of tires]
A 185 / 60R14 tire was prepared through a normal molding and vulcanization process using a dip cord topped with the coating rubber.

The properties of the tires in each example and comparative example were measured by the following test methods, and the results are shown in Tables 1 and 2.
(1) Drum durability The tires in each of the examples and comparative examples were adjusted to the maximum air pressure of JIS standard in a room at 25 ± 2 ° C and allowed to stand for 24 hours. A double load was applied to the tire, and a running test was performed at a speed of 60 km / h on a drum having a diameter of about 1.7 m.
The distance traveled until the failure occurred at this time was measured, and the travel distance until the failure occurred in the tire of Comparative Example 1 was displayed as an index. The larger the index, the longer the distance traveled until the failure occurred and the better the durability at high loads.

As shown in Tables 1 and 2, in Examples 1 to 11, the refined polysaccharide fibers used had high strength and high cut elongation, and as a result, good tire performance was obtained.
On the other hand, in the comparative example 1, since the strength and cutting elongation of the used refined polysaccharide fiber were low and the energy until cord cutting was low, good tire performance could not be obtained. Furthermore, since Comparative Example 1 was mainly composed of cellulose, the resource utilization rate was low.

Claims (17)

A purified polysaccharide fiber obtained by contacting a polysaccharide solution obtained by dissolving a polysaccharide raw material in a liquid containing a polar solvent or an ionic liquid with a solidified liquid, and then spinning the polysaccharide wet or dry and wet. ,
It contains a main component composed of two or more kinds of polysaccharides including a first main component, and the ratio of the first main component in all the components constituting the purified polysaccharide fiber is 97% by weight or less. Purified polysaccharide fiber.   The purified polysaccharide fiber according to claim 1, wherein a ratio of the first main component in all components constituting the purified polysaccharide fiber is 90% by weight or less.   The purified polysaccharide fiber according to claim 1 or 2, wherein a ratio of the polysaccharide fiber obtained from the polysaccharide raw material is 60% by weight or more.   The purified polysaccharide fiber according to any one of claims 1 to 3, wherein the main components are cellulose and hemicellulose.   The purified polysaccharide fiber according to any one of claims 1 to 4, wherein a ratio of the main component in all components constituting the purified polysaccharide fiber is 90% by weight or more.   The purified polysaccharide fiber according to claim 4 or 5, wherein a proportion of the hemicellulose in all components constituting the purified polysaccharide fiber is 0.1 to 40% by weight.   The purified polysaccharide fiber according to any one of claims 1 to 6, wherein the polar solvent is a dipole molecule or a zwitterionic molecule.   The purified polysaccharide fiber according to any one of claims 1 to 7, wherein the polar solvent is N-methylmorpholine-N-oxide.   The ionic liquid is composed of a cation portion and an anion portion, and the cation portion is one or more selected from the group consisting of an imidazolium ion, a pyridinium ion, an ammonium ion, and a phosphonium ion. The purified polysaccharide fiber according to one item. The purified polysaccharide fiber according to claim 9, wherein the cation moiety is an imidazolium ion represented by the following general formula (C1).

[Wherein, R ¹ represents an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, R ² represents a hydrogen atom or a methyl group, and R ³ represents 1 to 8 carbon atoms. Or an alkenyl group having 2 to 8 carbon atoms. ]   The purified polysaccharide fiber according to claim 9 or 10, wherein the anion moiety has a compound containing a phosphorus atom. The purified polysaccharide fiber according to claim 11, wherein the compound containing a phosphorus atom is any one of a phosphinate ion, a phosphate ion, and a phosphonate ion represented by the following general formula (C2).

[Wherein, X ¹ and X ² each independently represent a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 4 carbon atoms. ]   The refined polysaccharide fiber according to any one of claims 1 to 12, wherein the strong TB is 5.1 cN / dtex or more.   The refined polysaccharide fiber according to any one of claims 1 to 13, wherein the strong TB is 5.4 cN / dtex or more.   A fiber-rubber composite comprising the purified polysaccharide fiber according to any one of claims 1 to 14 and a rubber material.   A tire using the fiber-rubber composite according to claim 15.   The tire according to claim 16, wherein the fiber-rubber composite is used as a carcass ply, a belt ply, or a belt protective layer.