JP4670471B2 - Chargeable fiber and non-woven fabric, processed non-woven fabric using them - Google Patents

Description

  The present invention relates to a chargeable fiber. More specifically, the present invention relates to a chargeable fiber that does not require a washing step of a fiber treatment agent used for processed nonwoven products such as air filters and wipers.

In recent years, there has been increasing interest in dust-free, dust- and dust-free spaces, from buildings and underground malls and vehicles and amusement spaces to clean rooms such as laboratories and factories. There is an increasing demand for air filters and the like that collect dust using charging. For such an air filter, a synthetic fiber having a charging property and a non-woven fabric processed product made of the same are often used.
The above nonwoven fabric processed products are generally made of staple fibers and shortcut fibers as raw cotton, and after being webbed by a processing method such as the carding method or airlaid method, the nonwoven fabric obtained by thermal fusion or physical entanglement is subjected to electret treatment To obtain. The electret treatment is a step of charging the nonwoven fabric during processing into the nonwoven fabric or by making it into a thermal electret or corona discharge electret after the nonwoven fabric is formed.

In general, fibers used for nonwoven fabric processing have a fiber treatment agent such as a surfactant attached to the surface in order to suppress adverse effects on the processability and operability of the nonwoven fabric due to the generation of static electricity. However, in the case of the above-mentioned nonwoven fabric processed product, such a fiber treatment agent not only hinders the electret treatment but also causes a decrease in the collection efficiency with time.
Therefore, in the electret treatment process of nonwoven fabric, a method of introducing a washing process such as secondary water washing or hot water washing or a method of washing and removing the oil agent while being entangled by the water jet method is used. Restrictions arise, and problems such as an increase in process facilities and an increase in manufacturing costs have arisen. Further, Patent Document 1 discloses a method that enables non-woven fabrics and electrets by utilizing a decrease in the amount of oil agent attached in the heat treatment step. However, a restriction that a heat treatment step is necessarily required before electret processing and a high quality control technology that controls the amount of the fiber treatment agent to be adhered to a prescribed amount or less are required.

JP 2002-339256 A

  The present invention is a fiber made of a thermoplastic resin to which an oil agent is adhered to such an extent that the processability is not impaired by the generation of static electricity in a dry nonwoven fabric processing step such as a carding step or an airlaid step. It is an object of the present invention to provide a chargeable fiber that can be easily electret-treated without being restricted by a processing method such as a change in the amount of the oil agent attached or introduction of a cleaning process.

As a result of intensive studies to solve the above problems, the present inventors have found that by using a specific nonionic fiber treatment agent, it is possible to provide a fiber and a nonwoven fabric processed product that can be easily electret treated. The present invention has been completed based on the finding and the findings.
The present invention has the following configuration.

一般式（II）

（一般式（I）及び一般式（II）中、Ｒ^１,Ｒ^２,Ｒ^３はそれぞれ独立して水酸基、ポリオキシエチレン基またはポリオキシプロピレン基であり、それらの重合度（エチレンオキシド基またはプロピレンオキシド基の構成単位）はそれぞれ独立して０〜５５であり、Ｒ⁴は炭素数１６〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表す。）
一般式（III）

（式中、Ｒ⁵は炭素数１２〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表す。Ｒ^６は水素基又はメチル基を表し、ｋは５〜５０の整数である。）
一般式Ｘ

（式中、Ｒ⁷は炭素数１６〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表し、ｍは２〜５０の整数である）。
一般式Ｙ

（式中、Ｒ⁸，Ｒ⁹はそれぞれ単独に炭素数１６〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表し、ｎは２〜５０の整数である）。
〔２〕熱可塑性樹脂からなる繊維であって、下記一般式（I）もしくは下記一般式（II）で示されるソルビタン脂肪酸エステル類および下記一般式（III）で示されるポリオキシアルキレンアルキルエーテルからなる群から選ばれた少なくとも一種を５０重量％以上の範囲で含有する非イオン性の繊維処理剤（ただし、下記一般式Ｘ及び／またはＹで表されるポリオキシエチレン高級脂肪酸エステルを含む繊維処理剤を除く）を、該繊維に対して０．０１〜１．５重量％付着してなるエアレイド加工用帯電性繊維。
一般式（I）

一般式（II）

（一般式（I）及び一般式（II）中、Ｒ ^１ ,Ｒ ^２ ,Ｒ ^３ はそれぞれ独立して水酸基、ポリオキシエチレン基またはポリオキシプロピレン基であり、それらの重合度（エチレンオキシド基またはプロピレンオキシド基の構成単位）はそれぞれ独立して０〜５５であり、Ｒ ⁴ は炭素数１６〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表す。）
一般式（III）

（式中、Ｒ ⁵ は炭素数１２〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表す。Ｒ ^６ は水素基又はメチル基を表し、ｋは５〜５０の整数である。）
一般式Ｘ

（式中、Ｒ ⁷ は炭素数１６〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表し、ｍは２〜５０の整数である）。
一般式Ｙ

（式中、Ｒ ⁸ ，Ｒ ⁹ はそれぞれ単独に炭素数１６〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表し、ｎは２〜５０の整数である）。
〔３〕熱可塑性樹脂からなる繊維が、融点差を有する少なくとも２種類の熱可塑性樹脂で構成される複合繊維であって、少なくとも１種類の熱可塑性樹脂はポリオレフィンであり、該ポリオレフィンが複合繊維表面の少なくとも一部を長さ方向に連続して露出している熱接着性複合繊維である前記〔１〕または〔２〕項に記載の帯電性繊維。
〔４〕熱可塑性樹脂からなる繊維が、該繊維を構成する熱可塑性樹脂の少なくとも１種が反応性官能基を有するビニルモノマーからなる重合体（以下、これらを変性剤という）を含む樹脂である前記〔１〕〜〔３〕項のいずれか１項に記載の帯電性繊維
〔５〕帯電性繊維の繊維長が３〜４０ｍｍであることを特徴とする前記〔２〕、〔３〕または〔４〕項のいずれか１項に記載の帯電性繊維。
〔６〕帯電性繊維の繊維長が３２〜１２０ｍｍであることを特徴とする前記〔１〕、〔３〕または〔４〕項のいずれか１項に記載の帯電性繊維。
〔７〕前記〔５〕項に記載の帯電性繊維を用いて、エアレイド法によって得られる不織布。
〔８〕前記〔６〕項に記載の帯電性繊維を用いて、カード法によって得られる不織布。
〔９〕前記〔１〕〜〔６〕項のいずれか１項に記載の帯電性繊維と、他の繊維、不織布、フィルム、パルプシート、編み物及び織物から選ばれた少なくとも１種と混合して得られる複合化不織布。
〔１０〕前記〔７〕〜〔８〕項のいずれか１項に記載の不織布と、他の繊維、不織布、フィルム、パルプシート、編み物及び織物から選ばれた少なくとも１種とを積層して得られる複合化不織布。
〔１１〕前記〔７〕〜〔８〕項のいずれかに記載の不織布または前記〔９〕〜〔１０〕項記載の複合化不織布を用いた不織布加工品。
〔１２〕前記〔７〕〜〔８〕項のいずれかに記載の不織布または前記〔９〕〜〔１０〕項記載の複合化不織布をエレクトレット処理して用いたエアーフィルター。
〔１３〕前記〔７〕〜〔８〕項のいずれかに記載の不織布または前記〔９〕〜〔１０〕項記載の複合化不織布をエレクトレット処理して用いたワイパー。
〔１４〕前記〔７〕〜〔８〕項のいずれかに記載の不織布または前記〔９〕〜〔１０〕項記載の複合化不織布をエレクトレット処理して用いたマスク。
〔１５〕請求項７〜８のいずれか１項に記載の不織布または請求項９〜１０記載の複合化不織布に、エレクトレット処理を実施することを含む、不織布加工品の製造方法。 [1] A fiber made of a thermoplastic resin, comprising a sorbitan fatty acid ester represented by the following general formula (I) or the following general formula (II) and a polyoxyalkylene alkyl ether represented by the following general formula (III) Nonionic fiber treatment agent containing at least one selected from the group in a range of 50% by weight or more (however, a fiber treatment agent containing a polyoxyethylene higher fatty acid ester represented by the following general formula X and / or Y) Is a chargeable fiber for card processing in which 0.01 to 1.5% by weight is attached to the fiber.
Formula (I)

Formula (II)

(In General Formula (I) and General Formula (II), R ¹ , R ² and R ³ are each independently a hydroxyl group, a polyoxyethylene group or a polyoxypropylene group, and their degree of polymerization (ethylene oxide group or propylene The structural unit of the oxide group is independently 0 to 55, and R ⁴ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms.)
General formula (III)

(In the formula, R ⁵ represents a saturated or unsaturated aliphatic hydrocarbon group having 12 to 30 carbon atoms. R ⁶ represents a hydrogen group or a methyl group, and k is an integer of 5 to 50.)
Formula X

(In the formula, R ⁷ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms, and m is an integer of 2 to 50).
General formula Y

(In the formula, R ⁸ and R ⁹ each independently represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms, and n is an integer of 2 to 50).
[2] A fiber made of a thermoplastic resin, comprising a sorbitan fatty acid ester represented by the following general formula (I) or the following general formula (II) and a polyoxyalkylene alkyl ether represented by the following general formula (III) Nonionic fiber treatment agent containing at least one selected from the group in a range of 50% by weight or more (however, a fiber treatment agent containing a polyoxyethylene higher fatty acid ester represented by the following general formula X and / or Y) ) Is attached to the fiber in an amount of 0.01 to 1.5% by weight.
Formula (I)

Formula (II)

(In General Formula (I) and General Formula (II), R ¹ , R ² and R ³ are each independently a hydroxyl group, a polyoxyethylene group or a polyoxypropylene group, and their degree of polymerization (ethylene oxide group or propylene The structural unit of the oxide group is independently 0 to 55, and R ⁴ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms.)
General formula (III)

(In the formula, R ⁵ represents a saturated or unsaturated aliphatic hydrocarbon group having 12 to 30 carbon atoms. R ⁶ represents a hydrogen group or a methyl group, and k is an integer of 5 to 50.)
Formula X

(In the formula, R ⁷ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms, and m is an integer of 2 to 50).
General formula Y

(In the formula, R ⁸ and R ⁹ each independently represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms, and n is an integer of 2 to 50).
[3] A fiber composed of a thermoplastic resin is a composite fiber composed of at least two types of thermoplastic resins having a melting point difference, and the at least one type of thermoplastic resin is a polyolefin, and the polyolefin is a surface of the composite fiber. The chargeable fiber according to [1] or [2], which is a heat-adhesive conjugate fiber in which at least a part of the fiber is continuously exposed in the length direction.
[4] The fiber made of a thermoplastic resin is a resin containing a polymer (hereinafter referred to as a modifier) in which at least one of the thermoplastic resins constituting the fiber is made of a vinyl monomer having a reactive functional group. [2], [3] or [3], wherein the chargeable fiber according to any one of [1] to [3], [5] The length of the chargeable fiber is 3 to 40 mm. [4] The chargeable fiber according to any one of items [1] to [3] .
[6] The charging fiber according to any one of [1], [3] or [4], wherein the charging fiber has a fiber length of 32 to 120 mm.
[7] A nonwoven fabric obtained by the airlaid method using the chargeable fiber according to the above [5].
[8] A nonwoven fabric obtained by the card method using the chargeable fiber according to the item [6].
[9] A mixture of the chargeable fiber according to any one of [1] to [6] and at least one selected from other fibers, nonwoven fabrics, films, pulp sheets, knitted fabrics, and woven fabrics. The resulting composite nonwoven fabric.
[10] Obtained by laminating the nonwoven fabric according to any one of [7] to [8] above and at least one selected from other fibers, nonwoven fabrics, films, pulp sheets, knitted fabrics and woven fabrics Composite nonwoven fabric.
[11] A nonwoven fabric processed product using the nonwoven fabric according to any one of [7] to [8] or the composite nonwoven fabric according to [9] to [10].
[12] An air filter using the non-woven fabric according to any one of [7] to [8] or the composite non-woven fabric according to [9] to [10] after electret treatment.
[13] A wiper using the nonwoven fabric according to any one of [7] to [8] or the composite nonwoven fabric according to any of [9] to [10] after electret treatment.
[14] A mask using the non-woven fabric according to any one of [7] to [8] or the composite non-woven fabric according to [9] to [10] after electret treatment.
[15] A method for producing a processed nonwoven fabric product, comprising subjecting the nonwoven fabric according to any one of claims 7 to 8 or the composite nonwoven fabric according to claims 9 to 10 to electret treatment.

  The chargeable fiber of the present invention imparts appropriate chargeability to the fiber by attaching a nonionic fiber treatment agent made of sorbitan fatty acid esters or polyoxyalkylene alkyl ether. Therefore, non-woven fabric processing by air laid machines and card machines suppresses the generation of static electricity, and when performing electret processing on non-woven fabric, it is necessary and sufficient as the performance of non-woven fabric processed products without the need for removal processes such as washing process of fiber treatment agent. It is possible to charge a large amount of static electricity. In addition, since it is not necessary to control the amount of attached oil and fat by heat history, the web obtained from the fibers can use various non-woven fabric processing conditions such as a needle punch.

Hereinafter, the present invention will be described in detail.
The fiber treatment agent used for the chargeable fiber of the present invention may be composed only of sorbitan fatty acid esters and polyoxyalkylene alkyl ethers. In addition, antioxidants, antiseptics, rust inhibitors, antibacterials may be used as necessary. An agent, a wettability improver (hydrophilic agent) and the like can be blended within a range that does not impair the effects of the present invention.

一般式（II）

（一般式（I）及び一般式（II）中、Ｒ^１,Ｒ^２,Ｒ^３はそれぞれ独立して水酸基、ポリオキシエチレン基またはポリオキシプロピレン基であり、それらの重合度（エチレンオキシド基またはプロピレンオキシド基の構成単位）はそれぞれ独立して０〜５５であり、Ｒ⁴は炭素数１６〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表す。）
該ソルビタン脂肪酸エステル類は非イオン系の界面活性剤に分類され、高い湿潤性と粘調性を有している。 Sorbitan fatty acid esters are compounds having a structure represented by the following general formula (I) or (II).
Formula (I)

Formula (II)

(In General Formula (I) and General Formula (II), R ¹ , R ² and R ³ are each independently a hydroxyl group, a polyoxyethylene group or a polyoxypropylene group, and their degree of polymerization (ethylene oxide group or propylene The structural unit of the oxide group is independently 0 to 55, and R ⁴ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms.)
The sorbitan fatty acid esters are classified as nonionic surfactants and have high wettability and viscosity.

  Specific examples of sorbitan fatty acid esters used in the charging fiber of the present invention include sorbitan monolaurate, sorbitan monopalmylate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan sesquistearate, sorbitan trioleate Sorbitan tristearate, sorbitan monoisostearate, coconut oil fatty acid sorbitan, etc. Examples of polyoxyethylene derivatives of sorbitan fatty acid esters include polyoxyethylene (EO = 4) sorbitan monolaurate, polyoxy Ethylene (EO = 4) sorbitan tristearate, polyoxyethylene (EO = 4) sorbitan trioleate, polyoxyethylene (EO = 5) sorbitan monooleate, polyoxyethylene (EO = 6) sorbitan monooleate, polyoxyethylene (EO = 6) sorbitan monostearate, polyoxyethylene (EO = 20) monococonut oil fatty acid sorbitan, polyoxyethylene (EO = 20) sorbitan monopalmylate, poly Oxyethylene (EO = 5) sorbitan monolaurate, polyoxyethylene (EO = 20) sorbitan monolaurate, polyoxyethylene / polyoxypropylene sorbitan monolaurate, polyoxyethylene (EO = 20) sorbitan monostearate, Polyoxyethylene (EO = 20) sorbitan monoisostearate, polyoxyethylene (EO = 20) sorbitan monooleate, polyoxyethylene (EO = 20) sorbitan trioleate, polyoxyethylene (EO = 2) ) Such as sorbitan tristearate and the like. The sorbitan fatty acid esters used in the present invention are not particularly limited to these.

  When sorbitan fatty acid esters are contained as the main component of the fiber treatment agent, they are blended in an amount of 50% by weight or more, preferably 60 to 70% by weight, based on the weight of the fiber treatment agent. As other components to be blended, any nonionic surfactant is preferable, and these may be used to enhance the emulsification and antiseptic effects of the fiber treatment agent. Moreover, it does not prevent containing a polyoxyalkylene alkyl ether as a nonionic surfactant.

（式中、Ｒ⁵は炭素数１２〜３０の飽和もしくは不飽和の脂肪族炭化水素基を表す。Ｒ^６は水素基又はメチル基を表し、ｋは５〜５０の整数である。）
Ｒ⁵の炭素数は、繊維同士の摩擦を抑えて良好な開繊性を保つために１２以上であることが好ましく、また３０以下のものはポリオキシアルキレンアルキルエーテルそのものの合成が困難ではなく工業化に適している。Ｒ⁵の炭素数が１８〜３０の場合はさらに好ましい。また、式中のkの値は、１０〜２５である場合、さらに好ましい。 On the other hand, polyoxyalkylene alkyl ether is a compound having a structure represented by the following general formula (III).
General formula (III)

(In the formula, R ⁵ represents a saturated or unsaturated aliphatic hydrocarbon group having 12 to 30 carbon atoms. R ⁶ represents a hydrogen group or a methyl group, and k is an integer of 5 to 50.)
The carbon number of R ⁵ is preferably 12 or more in order to suppress the friction between the fibers and keep good opening property, and those having 30 or less are not difficult to synthesize polyoxyalkylene alkyl ether itself and are industrialized. Suitable for The case where R ⁵ has 18 to 30 carbon atoms is more preferable. Further, the value of k in the formula is more preferably 10-25.

  Specific examples of the polyoxyalkylene alkyl ether used in the charging fiber of the present invention include polyoxyethylene (k = 20) behen ether, polyoxyethylene (k = 14) stearyl ether, polyoxyethylene (k = 20). Tetracosane ether, polyoxyethylene (k = 18) octacosane ether, polyoxyethylene (k = 10) tria contour ether, polyoxyethylene (k = 5) lauryl ether, polyoxyethylene / polyoxypropylene (configuration of ethylene oxide) The unit is 2, the structural unit of propylene oxide is 6, and k = 8 as a whole. Examples include lauryl ether, but the polyoxyalkylene alkyl ether used in the present invention is not particularly limited thereto.

  When polyoxyalkylene alkyl ether is contained as the main component of the fiber treatment agent, it is blended in the range of 50% by weight or more, preferably in the range of 60 to 70% by weight, based on the weight of the fiber treatment agent. As other components to be blended, any nonionic surfactant is preferable, and these may be used to enhance the emulsification and antiseptic effects of the fiber treatment agent. Moreover, it does not prevent containing a sorbitan fatty acid ester as a nonionic surfactant.

  The fiber treatment agent used for the chargeable fiber of the present invention contains at least one selected from the above sorbitan fatty acid esters and polyoxyalkylene alkyl ether as a main component in the above weight ratio, and the other is any nonionic It does not preclude containing the ingredients. That is, the fiber treatment agent used in the present invention is preferably composed of nonionic components and does not contain ionic components. However, as long as the effects of the present invention are not impaired, it does not impede the inclusion of a trace amount of ionic components depending on the purpose. Further, the fiber treatment agent is used by dissolving in water as necessary.

  In the chargeable fiber of the present invention, the amount of the fiber treatment agent mainly composed of sorbitan fatty acid esters or polyoxyalkylene alkyl ether attached to the fiber is 0.01 to 1.5% by weight based on the fiber weight. Yes, preferably in the range of 0.15 to 1.0% by weight. By making the adhesion amount 0.15% by weight or more, generation of static electricity can be moderately suppressed, and the processability and texture of the nonwoven fabric are improved. By setting it to 1.5% by weight or less, charging of the nonwoven fabric during the electret treatment is not hindered by the fiber treatment agent, and the electret characteristics of the nonwoven fabric are improved.

The chargeable fiber of the present invention uses a fiber using a spinnable thermoplastic resin as a raw material, and a single fiber obtained by melt-spinning a thermoplastic resin alone or two or more uniformly mixed resins, A composite fiber obtained by composite spinning using two or more kinds of thermoplastic resins is used.
Examples of the thermoplastic resin include polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, polyolefins such as binary or ternary copolymers of propylene and other α-olefins, polyamides, polyethylene Examples thereof include terephthalate, polybutylene terephthalate, low melting point polyester obtained by copolymerizing diol and terephthalic acid / isophthalic acid, polyesters such as polyester elastomer, fluororesin, and a mixture of the above resins.

  When the chargeable fiber of the present invention is a composite fiber, a composite form such as a sheath-core type, a parallel type, a multi-layer type having three or more layers, a hollow multi-layer type, and an irregular multi-layer type can be used. At this time, the combination of the thermoplastic resins preferably has a melting point difference of 10 ° C. or more, and among the thermoplastic resins constituting the fibers, the low melting point thermoplastic resin exposes at least a part of the fiber surface, and further the fibers It is preferable to have a structure that is continuous along the length direction of the composite, and by this, heat treatment is performed at a temperature equal to or higher than the softening point or melting point of the low-melting thermoplastic resin and lower than the melting point of the high-melting thermoplastic resin. It is possible to form a thermoadhesive nonwoven fabric having a three-dimensional network structure in which the low melting point thermoplastic resin of the fiber is melted and the intersections of the fibers are thermally bonded.

  When the composite fiber used for the chargeable fiber of the present invention is composed of two types of thermoplastic resins, a low-melting point thermoplastic resin and a high-melting point thermoplastic resin, examples of the combination include high-density polyethylene / polypropylene, Density polyethylene / polypropylene, linear low density polyethylene / polypropylene, low density polyethylene / propylene-ethylene-butene-1 crystalline copolymer, ethylene-propylene copolymer / polypropylene, high density polyethylene / polyethylene terephthalate, nylon-6 / Examples include nylon 66, low melting point polyester / polyethylene terephthalate, polypropylene / polyethylene terephthalate, polyvinylidene fluoride / polyethylene terephthalate, a mixture of linear low density polyethylene and high density polyethylene / polyethylene, and the like. . Preferably, the composite fiber is made of a polyolefin-based component. Examples of such low-melting point thermoplastic resin / high-melting point thermoplastic resin combinations include high-density polyethylene / polypropylene, ethylene-propylene copolymer / polypropylene. Etc.

  The weight ratio of the low-melting thermoplastic resin and the high-melting thermoplastic resin constituting the composite fiber used for the charging fiber of the present invention is 10 to 90% by weight for the low-melting thermoplastic resin and 10 to 10% for the high-melting thermoplastic resin. 90% by weight, preferably 30 to 70% by weight of the low-melting point thermoplastic resin and 70 to 30% by weight of the high-melting point thermoplastic resin. When the low melting point thermoplastic resin is less than 10% by weight, the thermal adhesiveness is insufficient and the strength of the nonwoven fabric when processed into a nonwoven fabric is lowered. Conversely, when the low melting point thermoplastic resin exceeds 90% by weight, the high melting point thermoplastic resin as the core component is difficult to maintain the fiber form.

  In the composite fiber used for the chargeable fiber of the present invention, a polymer comprising a vinyl monomer having a reactive functional group in a low melting point component continuously exposed along a length direction on a part of the surface of the fiber. A resin (modifier) can be contained. The modifier is a resin having a reactive functional group, and examples of the reactive functional group include groups such as a hydroxyl group, amino, nitrile, nitrilo, amide, carbonyl, carboxyl, and glycidyl. The modified polyolefin can be polymerized using the vinyl monomer having the reactive functional group, and any of copolymers such as block, random, ladder, and graft polymers can be used. As the vinyl monomer having a reactive functional group, at least one unsaturated carboxylic acid selected from maleic anhydride, maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, a derivative thereof, or an anhydride thereof is used. Containing vinyl monomers, styrenes such as styrene and α-methylstyrene, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, or similar acrylic esters, etc. At least one vinyl monomer, glycidyl acrylate, glycidyl methacrylate, butenecarboxylic acid ester, allyl glycidyl ether, 3.4-epoxybutene, 5.5-epoxy-1-hexene, vinylcyclohexene monoxide, etc. And vinyl monomers containing one.

  Generally as a modifier, it is preferable to have the vinyl monomer which has the said reactive functional group with the modification | denaturation rate of 0.05-2.0 mol / kg with respect to the total weight of a modifier, 0.05-1. The case of 0 mol / kg is more preferable. From the viewpoint of cost and spinnability, the content of the modifier is preferably 80% by weight or less, more preferably 50% by weight or less, and more preferably 20% by weight or less, based on the weight of the sheath component of the composite fiber. Even more preferable.

  Since the modifier has high adhesiveness to other cellulosic fibers and inorganic substances when constituting the nonwoven fabric, and because it reacts with the fiber treatment agent to increase the chargeability of the chargeable fiber in the present invention, Then, a modified polyolefin composed of a vinyl monomer composed of an unsaturated carboxylic acid or a derivative thereof and a polyolefin can be preferably used as the modifier.

  Among the above modified polyolefins, a modified polyolefin which is a graft polymer can be used more preferably because of its high polymer strength and good fiber processability. With regard to the modification rate, the fiber processability and the effects of the present invention can be achieved. It is preferable to have a high denaturation rate as much as possible within the range not hindering.

As the trunk polymer of the modified polyolefin, polyethylene, polypropylene, polybutene-1, or the like is used. As the polyethylene, high density polyethylene, linear low density polyethylene, and low density polyethylene are used. These are polymers having a density of 0.90 to 0.97 g / cm ³ and a melting point of about 100 to 135 ° C. As the polypropylene, a propylene homopolymer and a copolymer of propylene and another α-olefin having propylene as a main component are used. These are polymers having a melting point of about 130 to 170 ° C. Polybutene-1 is a polymer having a melting point of about 110 to 130 ° C. Among these polymers, polyethylene is preferable in consideration of melting point, copolymerization, and ease of graft polymerization, and high-density polyethylene having high polymer strength is more preferable in order to improve the strength of the nonwoven fabric.

  As the low melting point component containing the modified polyolefin, a modified polyolefin alone, a mixture of at least two modified polyolefins, a mixture of at least one modified polyolefin and another thermoplastic resin, or the like can be used. The modified polyolefin generally has a tendency to decrease the polymer strength when compared with the unmodified polyolefin. Therefore, in order to maintain a higher fiber strength, a modified polyolefin having a high modification rate and an unmodified polyolefin can be used as a low melting point component. It is preferable to use a mixture with a modified polyolefin, and it is particularly preferable to use the same polymer as the backbone polymer of the modified polyolefin in terms of compatibility.

  When mixing the modifier with other thermoplastic resins, it is preferable to use a modifier with a high modification rate of about 0.1 mol / kg or more. By using the modifier, it is possible to add the effect of improving the adhesiveness of the chargeable fiber of the present invention to other cellulosic fibers and inorganic substances and improving the chargeability of the chargeable fiber of the present invention. This is presumed that the reactive functional groups of the fiber treatment agent and the modifying agent present on the fiber surface react to improve the chargeability. Moreover, it is preferable to mix with the same thermoplastic resin as the trunk polymer which comprises a modifier.

  The thermoplastic resin constituting the chargeable fiber of the present invention includes an antioxidant, a light stabilizer, an ultraviolet absorber, a neutralizer, a nucleating agent, an epoxy stabilizer, a lubricant, and the like within a range not impeding the effects of the present invention. Antibacterial agents, flame retardants, pigments, plasticizers and other thermoplastic resins can be added.

  The fineness of the chargeable fiber of the present invention is not particularly limited, but a range of 0.2 to 100 denier is preferably used. When the nonwoven fabric containing the chargeable fiber of the present invention is used for a filter member, a fineness in the range of 0.5 to 30 denier is preferably used, although it varies depending on the object to be collected and required air permeability.

  In general, the chargeable fiber of the present invention is used alone or mixed with other fibers such as nylon to form a web by a known processing method such as a card method, an airlaid method, etc. It is made a non-woven fabric by thermally fusing the intersections of the fibers with a machine or by mechanically interlacing the fibers with a water jet method or the like. The chargeable fiber of the present invention can be deposited on other nonwoven fabrics, films, pulp sheets, knitted fabrics, woven fabrics and the like to form composite nonwoven fabrics.

  Nonwoven fabrics using the charged fibers of the present invention and the composite nonwoven fabrics are nonwoven fabrics, fibers, films, pulp sheets obtained by other processing methods such as a card method, airlaid method, wet papermaking method, spunbond method, melt blow method, etc. It can be laminated with other sheets such as knitted fabrics, woven fabrics, wood boards and metal plates to form composite nonwoven fabrics.

  When the non-woven fabric processing is performed on the chargeable fiber of the present invention by the airlaid method, it is necessary to allow the fiber to pile up so as to form a web in which the fiber is uniformly dispersed through a sieve or a screen. For this purpose, it is preferable to use short fibers having a fiber length in the range of 3 to 40 mm. If the fiber length greatly exceeds 40 mm, uniform dispersion tends to be difficult, and formation unevenness tends to occur on the nonwoven fabric. On the contrary, if the fiber length is less than 3 mm, not only the strength of the nonwoven fabric is lowered when processed into a nonwoven fabric, but also the bulkiness characteristic of the airlaid method is easily lost.

  As a web manufacturing apparatus used in the airlaid method, for example, a box-type sieve type apparatus that vibrates in any of front and rear, left and right, upper and lower, horizontal circles, etc., and disperses and drops short fibers from the sieve eyes can be used. Further, a net-like cylindrical type apparatus in which a net-like metal perforated plate is formed into a cylindrical shape, has a fiber inlet on the side surface thereof, and disperses / drops the fiber from its sieve eyes can be used.

  When the chargeable fiber of the present invention is flown with a card machine, it is preferable to use a fiber having a fiber length of 32 to 120 mm. If fibers having a fiber length significantly exceeding 120 mm are fluffed, the fibers tend to be wound around the roller of the card machine, and if the length is less than 32 mm, the web is not sufficiently formed.

  The number of crimps of the chargeable fiber of the present invention is not particularly limited. However, when flowing with a card machine, a range of 3 to 20 ridges / 25 mm is preferable because web formation is good. At this time, the strength of the obtained nonwoven fabric is reduced when the number of crimps is less than 3 crests / 25 mm, and when the crest number exceeds 20 crests / 25 mm, the entanglement between the fibers is increased, and the fiber opening property is lowered. It becomes difficult to obtain a web having a uniform texture or a non-woven fabric. As the crimped shape, any shape such as a zigzag type two-dimensional crimp or a three-dimensional crimp such as a spiral type or an ohmic type can be used.

  The number of crimps of the chargeable fiber of the present invention is not particularly limited. However, when forming a web by the airlaid method, a range of 0 to 15 crests / 25 mm is preferable because the web formation is good. At this time, if the number of crimps exceeds 15 peaks / 25 mm, the entanglement between the fibers becomes large, the fiber opening property is lowered, and it becomes difficult to obtain a uniform textured web or a nonwoven fabric. As the crimped shape, any shape such as a zigzag type two-dimensional crimp or a three-dimensional crimp such as a spiral type or an ohmic type can be used.

  The web obtained by the airlaid method or the card method using the chargeable fiber of the present invention is processed into a nonwoven fabric by heat treatment or mechanical entanglement at the fiber intersection. Heat treatment uses a device that heats the intersection of the fibers by heating to a temperature lower than the softening point or lower melting point of the low-melting thermoplastic resin and lower than the melting point of the high-melting thermoplastic resin. A flat roll heat treatment machine or the like can be used. In particular, a web obtained by the airlaid method is suitable because a bulky nonwoven fabric can be obtained by using a through-air heat treatment machine. Mechanical entanglement is a method of mechanically entwining a web with a high-pressure water flow or a needle, and is suitable for obtaining a nonwoven fabric having a soft texture. Since the chargeable fiber of the present invention does not necessarily require the cleaning of the fiber treatment agent and the penetration of the components due to the heat history as in the prior art, it is possible to make the nonwoven fabric with such a needle.

The process for producing the heat-adhesive conjugate fiber used for the chargeable fiber of the present invention is shown below.
A parallel-type die so that the low-melting thermoplastic resin forms at least a part of the fiber surface, or a sheath-core die having a low-melting thermoplastic resin as a sheath component and a high-melting thermoplastic resin as a core component, or an eccentric sheath core Using a die die, a thermoplastic resin is spun by a commonly used melt spinning machine. At this time, the thermoadhesive conjugate fiber in an unstretched state is manufactured by blowing air just below the base by quenching and cooling the semi-molten thermoplastic resin. At this time, the discharge amount of the melted thermoplastic resin and the take-up speed of the undrawn yarn are arbitrarily set to obtain an undrawn yarn having a fiber diameter of about 1 to 5 times the target fineness. The ratio of the low-melting-point thermoplastic resin forming the fiber surface is preferably sufficient when the fiber cross-sectional circumference is 50% or more, and particularly when 50 to 100%, the strength becomes strong. This is not necessarily the case for improving electret characteristics. The obtained undrawn yarn can be made into a drawn yarn (heat-adhesive conjugate fiber before crimping) by drawing with a drawing machine usually used. In a normal case, stretching is performed between the rolls heated to 40 to 120 ° C. so that the speed ratio between the rolls is in the range of 1: 1 to 1: 5. The obtained drawn yarn is crimped by a box-type crimping machine to form a tow.
As for the process of attaching the fiber treatment agent, there are a method of attaching with a kiss roll at the time of taking an undrawn yarn, and a method of attaching by a touch roll method, a dipping method, a spray method, etc. at the time of drawing / after, at least one of these methods It is attached in the process. The tow is dried at 60 to 120 ° C. using a dryer, cut to an arbitrary fiber length according to the application using a push cutter, and used.

  The non-woven fabric using the chargeable fiber of the present invention is subjected to electret treatment such as a thermal electret method in which a charge is given in a heating atmosphere that does not melt the low melting point component of the fiber and a corona discharge method in which a charge is given by corona discharge. In this way, the non-woven fabric is charged with electric charge to give the non-woven fabric properties such as a collecting function. This is not particularly the case with respect to the electret processing method.

As described above, the nonwoven fabric using the chargeable fiber of the present invention can be obtained by, for example, the airlaid method or the card method. The basis weight of the nonwoven fabric is not particularly limited, but a basis weight in the range of 10 to 500 g / m ² when used for a wiper or the like, and a basis weight in the range of 8 to 1000 g / m ² when used for a filter is preferable.

The nonwoven fabric processed product using the chargeable fiber of the present invention can take various forms such as a fiber assembly, a web, a nonwoven fabric, a fiber tow, a paper-like material, a knitted fabric or a woven fabric depending on the application. Among these, those manufactured using the above-mentioned nonwoven fabrics and composite nonwoven fabrics are particularly preferable, and can be used for various applications. For example, the nonwoven fabric can be electret-treated and used for cleaning wipers for furniture, floors, etc., air filters, masks, etc. used in air conditioners and air conditioning equipment. As the composite non-woven fabric, for example, by laminating with a net, the non-woven fabric has mechanical strength and rigidity, can be pleated during filter processing, and can maintain the strength of the filter itself.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these. In addition, the measuring methods or definitions of physical property values shown in Examples and Comparative Examples are collectively shown below.
Crimp number: Measured according to JIS-L-1015.
Single yarn fineness: Measured according to JIS-L-1015.
Weight per unit area: The weight of the entire molded body obtained by cutting the nonwoven fabric into 50 cm squares was weighed and indicated by the weight per unit area (g / m ² ).
Fiber treatment agent adhesion amount (%): Extract fiber treatment agent adhering to fiber from 2 g of dried fiber with 25 ml of methanol, evaporate methanol from the extracted methanol, weigh the remaining residue, and calculate the weight ratio to fiber Value (%).
Collection efficiency (%): Using a particle measuring instrument (Rion Co., Ltd., Particle Counter KC-01 (0.3-5 μm)), air dust (0.3-5 μm) was passed through the nonwoven fabric at a speed of 5 cm / min. When the amount of dust collected on the nonwoven fabric was measured, the value (%) calculated at 100 minutes from the total amount of dust passed.
Non-woven fabric processability: A value obtained by sensorically comparing and evaluating the processability of a non-woven fabric processed by an airlaid method and a card method from the texture and openability of the obtained non-woven fabric and the dispersion state of the fibers. The obtained non-woven fabric was evaluated in terms of ◎ (good), ◯ (normal), and × (bad) in terms of good texture, openness and fiber dispersion.

  The components of the fiber treatment agent used in Examples 1 to 7 and Comparative Examples 1 to 3 and the blending ratio thereof are shown in Table 1, and the production conditions of the composite fibers obtained by attaching these fiber treatment agents are shown in Table 2. Indicated. In addition, the kiss roll system in the spinning process, or the touch roll system and the spray system in the stretching process were used as the method for attaching the fiber treatment agent. Moreover, the number of crimps of the fiber used was 10-13 threads / 25 mm.

Examples 1-4, 7 and Comparative Examples 1-3
Using each fiber shown in Table 2, a web with a basis weight of 100 g / m ² was made by the airlaid method and passed through a through air heat treatment machine at 138 ° C. to obtain a nonwoven fabric. An electret nonwoven fabric was prepared by holding a voltage of 10 kV for 2 seconds after holding it at 90 ° C. for 1 minute.

Example 4
A non-woven fabric was produced under the same airlaid method conditions as in Example 1 using chargeable fibers obtained by blending modified PE with sheath side thermoplastic resin (HDPE) shown in “Example 4” of Table 2. An electret nonwoven fabric was prepared by holding a voltage of 10 kV for 2 seconds after holding it at 90 ° C. for 1 minute.

Example 5
As shown in “Example 5” in Table 2, a tow prepared using an ethylene-propylene copolymer (ethylene component: 3.5% by weight) having a density of 0.9222 g / cm ² for the sheath side thermoplastic resin. The fiber length was cut to 51 mm, a web having a target weight of 100 g / m ^{2 was} obtained by a card method, and a nonwoven fabric was produced by passing through a through-air heat treatment machine at 138 ° C. An electret nonwoven fabric was prepared by holding a voltage of 10 kV for 2 seconds after holding it at 90 ° C. for 1 minute.

Example 6
Using the fibers shown in “Example 6” of Table 2 (tow cut into a fiber length of 51 mm), a web having a target basis weight of 100 g / m ² was made by the card method and passed through a needle punch processing machine to make a nonwoven fabric. Was made. An electret nonwoven fabric was prepared by holding a voltage of 10 kV for 2 seconds after holding it at 90 ° C. for 1 minute.

Example 7
As shown in “Example 7” of Table 2, a nonwoven fabric was produced under the same thermoplastic resin and processing conditions as in Example 1 except that the fiber treatment agent 4 was used and the fiber length was 3 mm. An electret nonwoven fabric was prepared by holding a voltage of 10 kV for 2 seconds after holding it at 90 ° C. for 1 minute.

Comparative Example 1
After the nonwoven fabric produced on the same conditions as Example 1 was washed with hot water and the fiber processing agent was washed, electret processing was performed and the nonwoven fabric was produced.

Comparative Examples 2-3
Although sorbitan fatty acid esters or polyoxyethylene alkyl ether was used as the fiber treatment agent, a nonwoven fabric was produced under the same conditions as in Example 1 except that a fiber treatment agent to which a cationic component was added was used.

The collection efficiency of the electret nonwoven fabrics of Examples 1 to 7 and Comparative Examples 1 to 3 was measured. Table 3 shows the results of the collection efficiency and the amount of attached oil and fat.
The collection efficiency is the dust collection rate when atmospheric dust passes through the nonwoven fabric, but it is considered to reflect the collection rate of dust collected by the electrostatic effect of the nonwoven fabric. This was used as an indicator of the chargeability of the nonwoven fabric. This indicates that a fiber having a high collection efficiency is excellent in chargeability.

Since the collection efficiency equivalent to the comparative example 1 which performed the conventional hot water washing process is obtained in Examples 1-6, the charging fiber of this invention does not need the washing | cleaning of a fiber treatment agent. Further, it was found that a heat history was not necessarily required during / after the nonwoven fabric processing, and good electrification was exhibited in electret processing. That is, by using the chargeable fiber of the present invention, it is possible to obtain electret fibers suitable for various non-woven fabric processing steps such as the needle punch method and the through air method without going through multi-step processing steps. However, in the fiber treatment agents having the ionicity of Comparative Examples 2 and 3, almost no chargeability due to electret processing was observed. This is presumably because the amount of electricity charged in the fiber is discharged through an ionic component present in the fiber treatment agent. Moreover, in Examples 4 and 5 using the same fiber treating agent as in Example 7, the chargeability (collecting efficiency) by the electret processing was remarkably excellent. The thermoplastic resin constituting the fiber was the result. The effect of the present invention can be further enhanced by selecting a thermoplastic resin. That is, the static electricity retention after electrification by electret processing largely depends on the fiber constituent resin, and it can be said that using a thermoplastic resin containing a modifier is one of the preferred embodiments of the present invention.
It should be noted that the fiber treatment agent 4 is considered to be a fiber treatment agent in which the component ratio of the fiber treatment agent is within a preferable range because good results are obtained in both electrification in electret processing and workability of the nonwoven fabric.

  The chargeable fiber of the present invention can be efficiently processed by suppressing the generation of static electricity in the process of processing into a non-woven fabric using an airlaid machine or a card machine. Since it can be sufficiently charged, it can be used for non-woven fabric processed products such as air filters and wipers that require a dust collection effect.

Claims (15)

A fiber made of a thermoplastic resin, selected from the group consisting of sorbitan fatty acid esters represented by the following general formula (I) or the following general formula (II) and polyoxyalkylene alkyl ether represented by the following general formula (III) Nonionic fiber treatment agent containing at least one of the above in a range of 50% by weight or more (excluding fiber treatment agents containing polyoxyethylene higher fatty acid ester represented by the following general formula X and / or Y) Is a chargeable fiber for card processing in which 0.01 to 1.5% by weight is attached to the fiber.
Formula (I)

Formula (II)

(In General Formula (I) and General Formula (II), R ¹ , R ² and R ³ are each independently a hydroxyl group, a polyoxyethylene group or a polyoxypropylene group, and their degree of polymerization (ethylene oxide group or propylene The structural unit of the oxide group is independently 0 to 55, and R ⁴ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms.)
General formula (III)

(In the formula, R ⁵ represents a saturated or unsaturated aliphatic hydrocarbon group having 12 to 30 carbon atoms. R ⁶ represents a hydrogen group or a methyl group, and k is an integer of 5 to 50.)
Formula X

(In the formula, R ⁷ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms, and m is an integer of 2 to 50).
General formula Y

(In the formula, R ⁸ and R ⁹ each independently represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms, and n is an integer of 2 to 50). A fiber made of a thermoplastic resin, selected from the group consisting of sorbitan fatty acid esters represented by the following general formula (I) or the following general formula (II) and polyoxyalkylene alkyl ether represented by the following general formula (III) Nonionic fiber treatment agent containing at least one of the above in a range of 50% by weight or more (excluding fiber treatment agents containing polyoxyethylene higher fatty acid ester represented by the following general formula X and / or Y) Is a chargeable fiber for airlaid processing, in which 0.01 to 1.5% by weight is attached to the fiber.
Formula (I)

Formula (II)

(In General Formula (I) and General Formula (II), R ¹ , R ² and R ³ are each independently a hydroxyl group, a polyoxyethylene group or a polyoxypropylene group, and their degree of polymerization (ethylene oxide group or propylene The structural unit of the oxide group is independently 0 to 55, and R ⁴ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms.)
General formula (III)

(In the formula, R ⁵ represents a saturated or unsaturated aliphatic hydrocarbon group having 12 to 30 carbon atoms. R ⁶ represents a hydrogen group or a methyl group, and k is an integer of 5 to 50.)
Formula X

(In the formula, R ⁷ represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms, and m is an integer of 2 to 50).
General formula Y

(In the formula, R ⁸ and R ⁹ each independently represents a saturated or unsaturated aliphatic hydrocarbon group having 16 to 30 carbon atoms, and n is an integer of 2 to 50). The fiber made of a thermoplastic resin is a composite fiber composed of at least two types of thermoplastic resins having a melting point difference, and the at least one type of thermoplastic resin is a polyolefin, and the polyolefin is at least one of the surfaces of the composite fiber. The chargeable fiber according to claim 1 or 2, which is a thermoadhesive conjugate fiber in which a portion is continuously exposed in the length direction. The fiber comprising a thermoplastic resin is a resin containing a polymer (hereinafter referred to as a modifier) in which at least one of the thermoplastic resins constituting the fiber is a vinyl monomer having a reactive functional group. The chargeable fiber according to any one of? The chargeable fiber according to any one of claims 2, 3 and 4, wherein the chargeable fiber has a fiber length of 3 to 40 mm. The chargeable fiber according to any one of claims 1, 3 and 4, wherein the length of the chargeable fiber is 32 to 120 mm. A nonwoven fabric obtained by the airlaid method using the chargeable fiber according to claim 5. A nonwoven fabric obtained by the card method using the chargeable fiber according to claim 6. A composite nonwoven fabric obtained by mixing the chargeable fiber according to any one of claims 1 to 6 and at least one selected from other fibers, nonwoven fabrics, films, pulp sheets, knitted fabrics, and woven fabrics. A composite nonwoven fabric obtained by laminating the nonwoven fabric according to any one of claims 7 to 8 and at least one selected from other nonwoven fabrics, fibers, films, pulp sheets, knitted fabrics, and woven fabrics. The nonwoven fabric processed product using the nonwoven fabric of any one of Claims 7-8, or the composite nonwoven fabric of Claims 9-10. The air filter which used the nonwoven fabric of any one of Claims 7-8, or the composite nonwoven fabric of Claims 9-10 for the electret process. A wiper using the nonwoven fabric according to any one of claims 7 to 8 or the composite nonwoven fabric according to claims 9 to 10 after electret treatment. The mask which used the nonwoven fabric of any one of Claims 7-8, or the composite nonwoven fabric of Claims 9-10 for the electret process. The manufacturing method of a nonwoven fabric processed article including implementing an electret process to the nonwoven fabric of any one of Claims 7-8, or the composite nonwoven fabric of Claims 9-10.