JP2019023374A - Hydrophilic cellulose acetate tow band and absorber using the same - Google Patents

Abstract

To provide a cellulose acetate-based absorber achieving all properties of liquid permeability, liquid diffusibility and liquid holding property at high level with good balance while capable of reducing thickness.SOLUTION: A hydrophilic cellulose acetate tow band is formed from cellulose acetate having a substitution degree of 2.0 to 2.6, 0.2 to 2 wt.% of a hydrophilic component with an HLB value of 16 or more is loaded based on the cellulose acetate tow band on a crimped cellulose acetate tow band surface having total denier of 10,000 to 40,000 and a crimp number of 30 to 60 pieces/inch. A fiber oil agent of 0.2 to 2 wt.% may be loaded to the cellulose acetate tow band by adding the hydrophilic component with the HLB value of 16 or more to the crimped cellulose acetate tow band surface.SELECTED DRAWING: None

Description

  The present invention relates to a hydrophilic cellulose acetate tow band useful as an absorbent material for absorbent materials for hygiene materials such as diapers and sanitary goods, a fiber sheet formed from the hydrophilic cellulose acetate tow band, and the fiber sheet. It is related with the absorber (absorbent article) used.

  Conventionally, an absorber used for sanitary products such as paper diapers is made of a polymer absorber such as fluff pulp and SAP (high water absorption resin). Such an absorber is thick and inconvenient to carry. In addition, since fluff pulp absorbs water itself, there is also a problem that the liquid permeation rate is slow.

  In order to solve the above-mentioned problems of the absorber using conventional fluff pulp, an absorber in which SAP is added to cellulose acetate as a main component has also been proposed. For example, Patent Document 1 discloses that a crimped tow is spread in a direction perpendicular to the direction of movement of the tow, de-aligned, molded into a substantially rectangular cross section, and a superabsorbent high in the entire molded tow. A method for producing an absorbent composite that distributes particulates such as molecules is disclosed. As the tow, a cellulose acetate tow produced for a tobacco filter is used. In the absorbent body using such cellulose acetate, the thickness of the absorbent body can be reduced, and a disposable diaper that is convenient to carry can be produced. Moreover, since it is excellent in permeability | transmittance, there also exists an advantage that SAP can be used effectively. However, a thin absorbent body using cellulose acetate has problems in terms of water absorption characteristics, particularly liquid diffusibility and liquid retention. That is, there is a problem that absorption of liquid such as urine is concentrated locally and does not spread around, and since liquid retention is low, there is a problem that it is easy to leak when inclined, and liquid permeation-liquid diffusion-liquid Among the water absorption functions of holding, the liquid diffusibility and liquid holding properties were slightly inferior and the balance was poor.

  As a technique of an absorbent body using filaments other than cellulose acetate, Patent Document 2 discloses an absorption using a nonwoven fabric mainly composed of polyolefin-based or polyester-based fibers and having a fiber surface treated with sericin as a skin contact surface side material. A sex product is disclosed. Patent Document 3 discloses a wet laid web of cellulose fibers for use in the production of fiber airlaid lumps, the fiber treatment comprising cellulose fibers and at least one reagent having polysaccharide and hydrogen bond functionality. A wet laid web of fibers is disclosed, wherein the fiber treatment composition is distributed within the wet laid web of cellulose fibers. Further, Patent Document 4 discloses a synthetic fiber bundle that transports an aqueous fluid, and the fiber includes 10% by weight of a solution of poly [polyethylene glycol (1400) terephthalate] and 44.1% by weight of polyethylene glycol (400). Synthetic fiber coated with a lubricant comprising monolaurate, 44.1% by weight polyethylene glycol (600) monolaurate and 1.8% by weight 4-cetyl-, 4-ethylmorpholinium ethosulphate A bundle is disclosed.

  Patent Document 5 discloses an absorbent article having fibers that satisfy specific parameters. This document describes 49% polyethylene glycol (PEG) 600 monolaurate, polyoxyethylene (13.64) monolaurate, 49% as particularly preferred hydrophilic lubricants that can be used to lubricate the fibers. A lubricant consisting of polyethylene glycol (PEG) 400 monolaurate, polyoxyethylene (9.09) monolaurate, and 2% 4-cetyl-4-ethylmorpholinium ethosulphate is described. Further, in this document, polyester is exemplified as a preferable material used for producing fibers, and polyamide, polypropylene, polyethylene, and cellulose ester are exemplified as other materials.

  In addition, in the field of cellulose acetate for tobacco filters (filtered tow for tobacco), as described in Patent Document 6, in the fiber production process (spinning process), the convergence, smoothness, and antistatic properties of the fiber yarns. In order to improve the above, it is a common practice to apply a fiber oil to the traveling fiber yarn (filament). The fiber oil agent contains an oil and fat component as a main component, and an additive such as a surfactant is added thereto as necessary. In the fiber oil application technology in such a spinning process, uniform application of the fiber oil improves the converging property, smoothness, antistatic property, etc. of the fiber yarn, and is caused by contact wear with equipment. Emphasis is placed on preventing quality deterioration due to fiber damage, deterioration of the working environment due to fiber pieces cut by abrasion, and quality deterioration due to fiber pieces cut by abrasion. In the filter tow for cigarettes, it is necessary to crimp the tow in order to ensure ventilation resistance. In order to crimp the tow, it is essential that the tow contains a certain amount of moisture. For this reason, in the spinning of filter tow, a fiber oil agent emulsion which is a suspension obtained by diluting a fiber oil agent with water (that is, a suspension of water and oil) is used. The oil agent concentration in the fiber oil agent emulsion is about 2 to 10% by weight.

JP 2004-244794 A JP-A-9-322911 JP 2004-143653 A Special table 2001-500198 gazette JP 2003-33398 A JP 2007-77525 A

  An object of the present invention is to provide a cellulose acetate absorbent material that can be thinned and has all of the properties of liquid permeability, liquid diffusibility, and liquid retention at a high level in a balanced manner, and a fiber comprising the cellulose acetate absorbent material It is providing the sheet | seat and the absorber using this fiber sheet.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have formed an HLB value on the surface of a crimped cellulose acetate tow band formed from cellulose acetate having a specific substitution degree and having a total denier within a specific range. It has been found that a material to which a hydrophilizing component of a specific value or more is attached can be used as an absorbent material that can reduce the thickness and has all the properties of liquid permeability, liquid diffusibility and liquid retention at a high level in a well-balanced manner. The present invention has been completed.

  That is, the present invention provides a crimped cellulose acetate tow band surface formed from cellulose acetate having a substitution degree of 2.0 to 2.6, having a total denier of 10,000 to 40,000 and a crimp number of 30 to 60 / inch. Further, a hydrophilic cellulose acetate tow band characterized in that 0.2 to 2% by weight of a hydrophilic component having an HLB value of 16 or more is attached to the cellulose acetate tow band.

  Further, the present invention provides the hydrophilic cellulose acetate tow band wherein the hydrophilic component having an HLB value of 16 or more is at least one selected from polyoxyethylene sorbitan monolaurate and polyethylene glycol monostearate. provide.

  In the present invention, the surface of the crimped cellulose acetate tow band has a fiber oil added to the cellulose acetate tow band in an amount of 0.2 to 2% by weight in addition to the hydrophilic component having an HLB value of 16 or more. The hydrophilic cellulose acetate tow band is provided.

  The present invention also provides the hydrophilic cellulose acetate tow band wherein the total amount of the hydrophilic component having a HLB value of 16 or more and the fiber oil agent is 0.4 to 3% by weight based on the cellulose acetate tow band. I will provide a.

  In addition, the present invention provides the hydrophilic cellulose acetate tow band, wherein the crimped cellulose acetate tow band has a filament denier of 1.0 to 7.0.

  The present invention also provides a fiber sheet formed from the hydrophilic cellulose acetate tow band.

  The present invention further provides an absorbent body in which a highly water-absorbent resin is dispersed in the fiber sheet.

The present invention further includes (A) a step of discharging cellulose acetate having a substitution degree of 2.0 to 2.6 dissolved in an organic solvent from a die with a spinning cylinder to obtain a cellulose acetate filament,
(B) A step of attaching a fiber oil agent to the obtained cellulose acetate filament,
(C) a step of attaching a hydrophilic component to the obtained cellulose acetate filament,
(D) combining cellulose acetate filaments obtained from a plurality of spinning cylinders to obtain a cellulose acetate tow band having a total denier of 10,000 to 40,000, and (E) crimping the cellulose acetate tow band, A method for producing a hydrophilic cellulose acetate tow band comprising the step of obtaining a crimped cellulose acetate tow band having a number of crimps of 30 to 60 pieces / inch.

  In the step (B), the present invention is the cellulose acetate filament obtained by attaching a hydrophilic component together with a fiber oil to the obtained cellulose acetate filament, and then attaching the fiber oil and the hydrophilic component in the step (C). Provided is a method for producing a hydrophilic cellulose acetate tow band, wherein a hydrophilic component is further attached to a filament.

  Moreover, this invention provides the manufacturing method of the said hydrophilic cellulose acetate tow band which implements each process in order of a process (B), a process (D), and a process (C).

The hydrophilic cellulose acetate tow band of the present invention is formed from cellulose acetate having a substitution degree of 2.0 to 2.6, and has a total denier of 10,000 to 40,000 and a crimp number of 30 to 60 pieces / inch. Since a specific amount of a hydrophilic component having an HLB value of 16 or more is attached to the surface of the cellulose acetate tow band, water absorption characteristics, in particular, liquid diffusibility and Liquid retention (wetting characteristics) is improved, and the above characteristics are well-balanced. Further, since cellulose acetate tow is used, the thickness can be reduced without being bulky. Therefore, it can be used as an absorbent material for absorbents for sanitary materials such as diapers and sanitary products.
Note that cellulose acetate having a substitution degree of 2.0 to 2.6 is not water-soluble, and therefore its surface is not water-soluble. However, a hydrophilizing component having an HLB of 16 or more is water-soluble. Therefore, the surface of cellulose acetate can be made hydrophilic by attaching a hydrophilic component having an HLB of 16 or more.
Moreover, the absorbent body of the present invention maintains the liquid permeability inherent to cellulose acetate tow because the superabsorbent resin (SAP) is dispersed in the fiber sheet made of the above-mentioned hydrophilic cellulose acetate tow. Thus, the water absorption time is short, and for example, urinated urine can be absorbed in a short time. Moreover, since it has excellent liquid diffusibility and a wide-area SAP can be used, for example, there is little urine return (rewetting) and a comfortable feeling of use can be obtained. Further, the liquid retention is excellent, and for example, side leakage due to movement of a baby or the like can be reduced.

  Furthermore, according to the method for producing a hydrophilic cellulose acetate tow of the present invention, it is possible to industrially efficiently produce a cellulose acetate tow having a hydrophilic surface with excellent liquid permeability and water absorption characteristics. it can.

It is explanatory drawing which shows typically an example of the apparatus used for the manufacturing method of the hydrophilic cellulose acetate tow band of this invention.

[Hydrophilic cellulose acetate tow band]
The hydrophilic cellulose acetate tow band of the present invention is formed from cellulose acetate having a substitution degree of 2.0 to 2.6, and has a total denier of 10,000 to 40,000 and a crimp number of 30 to 60 pieces / inch. A hydrophilic component having an HLB value of 16 or more is attached to the surface of the cellulose acetate tow band. In the present invention, it is sufficient that the cellulose acetate tow band is crimped and a hydrophilic component having an HLB value of 16 or more is attached in the final form, and the operation order of crimping and attachment of the hydrophilic component is not limited. Absent.

  In the present invention, the degree of substitution (acetyl substitution degree) of cellulose acetate constituting the cellulose acetate tow band is 2.0 to 2.6, preferably 2.1 to 2.5.

  The cellulose acetate fiber constituting the cellulose acetate tow band is usually a long fiber produced by dry spinning. Depending on the shape of the die and other spinning conditions, products having different cross-sectional shapes and fineness can be obtained.

  The cross-sectional shape of the cellulose acetate fiber may be a circular shape or an irregular shape (for example, an elliptical shape, a polygonal shape, a T shape, an I shape, a Y shape, an X shape, etc.). . A fiber having an irregular cross section has a higher water absorption capacity than a fiber having a circular cross section, and is more suitable for use as an absorbent material. The cross-sectional shape of the cellulose acetate fiber is particularly preferably Y-shaped (Y-shaped).

  The single fiber fineness of the cellulose acetate fiber is not particularly limited, and is, for example, 0.1 to 20 denier, preferably 1.0 to 7.0 denier.

  As described above, the cellulose acetate tow band in the present invention is an aggregate of crimped long fiber bundles. The total denier of the cellulose acetate tow band is 10,000 to 40000, preferably 15000 to 35000, and more preferably 20000 to 30000. If the total denier of the cellulose acetate tow band is less than 10,000, it will be difficult to apply crimps uniformly, and it will be difficult to maintain the form of the absorbent when it is made into an absorbent. On the other hand, if the total denier of the cellulose acetate tow band exceeds 40,000, the thickness of the absorbent body becomes thick and unpleasant.

  Further, the number of crimps in the crimped cellulose acetate tow band is 30 to 60 / inch, preferably 30 to 40 / inch. When the number of crimps of the cellulose acetate tow band is less than 30 / inch, the swelling is insufficient when the fiber is opened. Further, if the number of crimps exceeds 60 / inch, the crimps are highly crimped and the tow is damaged, which is not preferable.

  In the present invention, as described above, it is important that a hydrophilic component having an HLB value of 16 or more is attached to the surface of the cellulose acetate tow band.

  The hydrophilic component having an HLB value of 16 or more is not particularly limited, and a nonionic surfactant having an HLB value of 16 or more can be preferably used. More specifically, as the hydrophilizing component having an HLB value of 16 or more, for example, polyoxyethylene sorbitan monolaurate (twin 20) (HLB value 16.7), polyethylene glycol monostearate (HLB value 18.0) However, it is not limited to these. Hydrophilic components having an HLB value of 16 or more may be used alone or in combination of two or more.

  The HLB value of the hydrophilic component is preferably 16.5 or more. The upper limit of the HLB value of the hydrophilic component is not particularly limited, but is usually 20.0 and may be 19.0.

  As the hydrophilizing component having an HLB value of 16 or more, the above-mentioned polyoxyethylene sorbitan monolaurate (HLB16.7) is particularly preferable because of its high versatility.

  The amount of the hydrophilic component having an HLB value of 16 or more attached to the cellulose acetate tow band is 0.2 to 2% by weight, preferably 0.25 to 1% by weight, based on the cellulose acetate tow band. Since the hydrophilizing component having an HLB value of 16 or more is attached to the cellulose acetate tow band within the above range, the liquid diffusibility and liquid retention (wetting) are maintained while maintaining the liquid permeability inherent in the cellulose acetate tow band. Characteristics) are greatly improved.

  The method for treating the cellulose acetate tow band surface with a hydrophilizing component having an HLB value of 16 or more is not particularly limited. For example, using an aqueous solution in which a hydrophilizing component having an HLB value of 16 or more is dissolved in water, the hydrophilic surface having a HLB value of 16 or more is formed on the surface of the cellulose acetate tow band by a general surface treatment method such as a dipping method, a spraying method, or a coating method. Can be imparted (attached).

  In the present invention, the hydrophilic component having an HLB value of 16 or more may be attached to the surface of the cellulose acetate tow band, but the spinnability, fiber yarn convergence, fiber surface smoothness, antistatic property In order to improve the friction preventing property, the surface of the cellulose acetate tow band is preferably further treated with a fiber oil agent.

  It does not specifically limit as a fiber oil agent, A well-known or usual fiber oil agent can be used. Examples of the fiber oil agent include mineral oil and esterified oil. Of these, mineral oil is preferable. A textile oil agent may be used individually by 1 type, and may use 2 or more types together.

  The amount of the fiber oil to be attached to the cellulose acetate tow band can be appropriately selected depending on the kind of cellulose acetate tow band and the fiber oil, the processing method, etc., but generally 0.2 to 2% by weight, for example, with respect to the cellulose acetate tow band. , Preferably 0.25 to 1% by weight.

  The method for treating the cellulose acetate tow band surface with a fiber oil agent is not particularly limited. For example, by using a fiber oil agent itself, a solution in which the fiber oil agent is dissolved in an organic solvent, or an emulsion in which the fiber oil agent is suspended in water, cellulose acetate is obtained by a general surface treatment method such as a dipping method, a spray method, or a coating method. A fiber oil agent can be applied (attached) to the tow band surface.

  When using the emulsion (fiber oil agent emulsion) which suspended the fiber oil agent in water, you may add surfactant as needed. Examples of the surfactant include an anionic surfactant and a nonionic surfactant having an HLB value of less than 16.

  The fiber oil emulsion is preferably a fiber oil emulsion having a total light transmittance of 850 nm light of 30% or more measured at an emulsion concentration of 5% by weight (see JP 2007-77525 A). By attaching such fiber oil emulsion to cellulose acetate tow fiber yarns, quality degradation due to fiber damage due to contact wear with equipment in the fiber manufacturing process, and deterioration of work environment due to fiber pieces cut by wear Can be remarkably suppressed, and the frictional force between the spinning guide and the tow band during filament spinning is reduced, and the frequency of gody roll breakage in the spinning process can be significantly reduced.

  When the fiber oil agent is attached to the cellulose acetate tow band surface together with the hydrophilic component having an HLB value of 16 or more, the total amount of the hydrophilic component having an HLB value of 16 or more and the fiber oil agent is, for example, 0.4 to 3% by weight, Preferably it is 0.5 to 2 weight%, More preferably, it is 0.5 to 1.5 weight%, More preferably, it is 0.6 to 1.2 weight%. If the total amount of the hydrophilic component having a HLB value of 16 or more and the fiber oil agent is too large, problems such as loosening of the yarn and dropping of the droplets may occur during the production process.

  The hydrophilic cellulose acetate tow band of the present invention has a total denier within a specific range, and the surface of the crimped cellulose acetate tow band with a specific number of crimps has a HLB value of 16 or more. Is added, while maintaining the liquid permeability that is the original characteristic of cellulose acetate tow, water absorption characteristics, in particular, liquid diffusibility and liquid retention (wetting characteristics) are improved, and the above characteristics are well-balanced. . Further, since the cellulose acetate tow band is used, the thickness can be reduced without being bulky. Therefore, it can be used as an absorbent material for absorbents for sanitary materials such as diapers and sanitary products.

  The hydrophilized cellulose acetate tow band of the present invention can be produced, for example, based on the following method.

[Production of hydrophilized cellulose acetate tow band]
The cellulose acetate tow band that has been made hydrophilic can be produced by treating the surface of the cellulose acetate tow band with a hydrophilic component (particularly, a hydrophilic component having an HLB value of 16 or more). The surface of the cellulose acetate tow band is treated with a fiber oil in addition to the above-mentioned hydrophilizing component in order to improve the spinnability, fiber yarn bundling, fiber surface smoothness, antistatic property and anti-friction property. It is preferable.

As a method for producing a hydrophilic cellulose acetate tow band in which both a hydrophilic component and a fiber oil agent are applied (attached) to the surface of the cellulose acetate tow band, for example,
(A) A step of discharging cellulose acetate having a substitution degree of 2.0 to 2.6 dissolved in an organic solvent from a die with a spinning cylinder to obtain a cellulose acetate filament,
(B) A step of attaching a fiber oil agent to the obtained cellulose acetate filament,
(C) a step of attaching a hydrophilic component to the obtained cellulose acetate filament,
(D) combining cellulose acetate filaments obtained from a plurality of spinning cylinders to obtain a cellulose acetate tow band having a total denier of 10,000 to 40,000, and (E) crimping the cellulose acetate tow band, A method of obtaining a cellulose acetate tow band hydrophilized through a step of obtaining a crimped cellulose acetate tow band having a number of crimps of 30 to 60 pieces / inch is mentioned.

  In the above production method, the attaching (applying) of the fiber oil agent [Step (B)] and the attaching (applying) of the hydrophilizing component [Step (C)] may be performed simultaneously or sequentially (in this case, Either may be applied first, but it is preferable to add the fiber oil first), or they may be combined. Further, the step (D) for forming the tow band may be performed either before or after the step (B), or may be performed before or after the step (C). In this invention, it is preferable to implement each process in order of a process (B), a process (D), and a process (C).

  The production method includes, for example, the following three embodiments: Method I, Method II, and Method III.

[Method I]
In step (B), a fiber oil agent is attached to the cellulose acetate filament obtained in step (A) (no hydrophilic component is attached). Thereafter, in step (C), the cellulose acetate filament is attached with the fiber oil agent. A method of attaching a hydrophilizing component to the surface.
[Method II]
A method of attaching a hydrophilizing component together with a fiber oil agent in the step (B) to the cellulose acetate filament obtained in the step (A) [a method of simultaneously performing the step (B) and the step (C)].
[Method III]
The cellulose acetate filament obtained by attaching a hydrophilic component together with the fiber oil agent in the step (B) to the cellulose acetate filament obtained in the step (A), and then attaching the hydrophilic component together with the fiber oil agent in the step (C). And a method of further attaching a hydrophilic component.

  Among these methods, Method III makes it easier for the hydrophilizing component to be present on the outermost surface, greatly improving water absorption characteristics, particularly liquid diffusibility and liquid retention (wetting characteristics), as well as fiber oil agent and hydrophilizing component. Since the hydrophilizing component is applied after the mixture is applied, this is a particularly preferable method in that the hydrophilizing component to be applied later is easily placed. In the case of Method III, the amount of the hydrophilizing component used in the step (C) is, for example, 5 to 95 with respect to the total use amount of the hydrophilizing component [total amount used in the steps (B) and (C)]. % By weight, preferably 30 to 90% by weight, more preferably 50 to 85% by weight.

  In any of the above methods, in the step (B), a fiber oil agent (or a mixture of a fiber oil agent and a hydrophilizing component) is attached in the form of cellulose acetate tow fiber yarns that are collected and bundled in a rope shape in the step (B). It is preferable to do this.

  In the step (C), the hydrophilic component is added to the tow band obtained by combining cellulose acetate filaments (particularly, cellulose acetate tow fiber yarns) obtained from a plurality of spinning cylinders [that is, after the step (D)]. The attachment is preferable from the viewpoint of production efficiency and the like.

  FIG. 1 is an explanatory view schematically showing an example of an apparatus used in the method for producing a hydrophilic cellulose acetate tow band of the present invention.

  In the apparatus of FIG. 1, a plurality of cellulose acetate filaments spun from the spinneret 1 are converged in a plurality of spinning cylinders to produce a rope-like cellulose acetate tow fiber yarn 2, which is obtained from the plurality of spinning cylinders. A cellulose acetate tow band 7 is produced by converging a plurality of the cellulose acetate tow fiber yarns 2 into a strip shape.

  This device includes a fiber oil agent applying device 3 for applying a fiber oil agent (or a mixture of a fiber oil agent and a hydrophilic component) to the cellulose acetate tow fiber yarn 2, and a fiber oil agent (or fiber oil agent) obtained from a plurality of spinning cylinders. A cellulose acetate tow fiber yarn 2 to which a cellulose acetate tow fiber yarn 2 provided with a mixture of hydrophilizing components is bundled to form a cellulose acetate tow band 7, and a cellulose acetate tow band 7 formed by the tow band forming device 6. A hydrophilizing component imparting device 8 that imparts a hydrophilizing component (particularly, a hydrophilizing component having an HLB value of 16 or more) and a crimp imparting device 9 that imparts crimps to the cellulose acetate tow band 7 imparted with the hydrophilizing component. And. Furthermore, in this apparatus, a goded roll (godi roll) 4 and a guide 5 are installed so that a cellulose acetate tow band 7 is smoothly formed from the cellulose acetate tow fiber yarn 2 to which the fiber oil agent is applied. In the method II, the hydrophilizing component applying device 8 is not necessary.

  The fiber oil agent applying device 3 is not particularly limited as long as it can apply a fiber oil agent (or a mixture of a fiber oil agent and a hydrophilizing component) to the cellulose acetate tow fiber yarn 2. An apparatus (fiber oil agent attaching apparatus) can be used. Examples of the fiber oil application device 3 include application devices such as a roller method, a nozzle method, and a slit method.

  The hydrophilizing component imparting device 8 is not particularly limited as long as it can impart a hydrophilizing component (particularly a hydrophilizing component having an HLB value of 16 or more) to the cellulose acetate tow fiber yarn 2. For example, the fiber An oil agent applying device (fiber oil agent attaching device) can be diverted. That is, in the fiber oil agent applying device (fiber oil agent attaching device), it can be used as the hydrophilizing component applying measure 8 by using a hydrophilizing component instead of the fiber oil agent (or a mixture of the fiber oil agent and the hydrophilizing component).

  In this example, the imparting (attachment) of the hydrophilizing component to the cellulose acetate tow band surface is performed after the fiber oil agent applying (attaching) step and the tow band forming step and before the crimping step. However, the present invention is not limited to this, and it may be performed at an appropriate stage. However, since it is desirable to impart spinnability, fiber yarn bundling, fiber surface smoothness, antistatic properties, and anti-friction properties to the cellulose acetate tow at an early stage, the hydrophilic component of the cellulose acetate tow The application (attachment) is preferably performed after the application (attachment) of the fiber oil [particularly after the cellulose acetate tow provided with the fiber oil is used as a tow band]. In addition, from the viewpoint that the hydrophilic component can be uniformly attached to the surface of the cellulose acetate tow band, it is preferable to impart (attach) the hydrophilic component to the surface of the cellulose acetate tow band before the crimping step.

  The crimp imparting device 9 is not particularly limited, and a known or commonly used crimp imparting device can be used. The crimping device 9 can perform sufficient crimping (crimper treatment) on the cellulose acetate tow band 7.

[Fiber sheet]
The fiber sheet of the present invention is formed from the hydrophilic cellulose acetate tow band of the present invention.

  The fiber sheet can be produced, for example, by opening the cellulose acetate tow band imparted with the crimp and then forming the sheet into a sheet shape.

  The opening of the crimped cellulose acetate tow band can be performed using a known or conventional opening method, for example, a mechanical opening method using a roller or the like, or a gas opening method using air or the like. In addition, opening (blooming) is to loosen the fibers and increase the bulk by pushing and expanding the crimped fibers in the length direction and the width direction.

  The method for forming the opened fiber into a sheet is not particularly limited, and is a known or conventional method, for example, a method in which the opened fiber is sandwiched between two plates and pressed into a sheet, or between a pair of rollers. A method of forming a sheet through the opened fiber can be adopted.

  As a method of opening the crimped fiber with a pressurized gas and forming the spread fiber obtained by opening into a sheet, for example, the crimped fiber is supplied to an opening chamber having an elliptical cross section or a circular cross section. Further, there is a method of opening with a pressurized gas and forming the resulting spread fiber into a sheet (see Japanese Patent Application Laid-Open No. 2008-255529). According to such a method, it is possible to obtain a fiber sheet that is remarkably excellent in absorbability with respect to liquids such as moisture. Moreover, while being able to adjust the thickness and width of a fiber sheet easily, thickness can be partially enlarged, and especially the fiber sheet from which thickness distribution differs in the width direction can be obtained.

The bulk specific gravity of the fiber sheet of the present invention can be appropriately set according to the use and purpose, but is generally 0.005 to 0.1 g / cm ³ , preferably 0.01 to 0.05 g / cm ³ . Moreover, the fiber sheet of the present invention can be used after being cut into an appropriate size according to the application and purpose.

[Absorber]
In the absorbent body according to the present invention, the superabsorbent resin (SAP) is dispersed in the fiber sheet according to the present invention. A well-known thing can be used as a highly water-absorbing resin (SAP).

The absorbent body can be produced, for example, by uniformly spraying the superabsorbent resin over the entire fiber sheet or in a predetermined range and hot pressing. Although the usage-amount of superabsorbent resin can be suitably set according to a use and the objective, it is 50-1000 g / m < ² > normally as a basis weight, for example, Preferably it is 100-500 g / m < ² >.

  Since the hydrophilic cellulose acetate tow is used as an absorbent material in the absorbent body of the present invention, the water absorption time is shorter than that of fluff pulp, and for example, urinated urine can be absorbed in a short time. it can. Moreover, since it has excellent liquid diffusibility and can use a wide water-absorbent resin (SAP), for example, urine or the like is less likely to return (rewet), and a comfortable feeling can be obtained. Further, the liquid retention is excellent, and for example, side leakage due to movement of a baby or the like can be reduced. Therefore, the absorbent body of the present invention is particularly useful as an absorbent body for sanitary materials such as disposable diapers, sanitary napkins and breast milk pads.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Preparation Example 1)
Fiber oil agent (mineral oil, trade name “DC-18”, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) was adjusted to 35 ° C., and water (diluted water) adjusted to 35 ° C. was added and stirred, and the emulsion concentration was 40 A weight percent fiber oil emulsion was prepared.
In addition, the phase inversion point of the said fiber oil agent was 50 weight%, and the dilution rate in the phase inversion point was 0.13 kg / min per kg of fiber oil agent. The average particle size of the emulsion was 0.199 μm. Moreover, the total light transmittance of the light of 850 nm measured with the emulsion density | concentration of 5 weight% of the obtained fiber oil agent emulsion was 34.8%.

(Preparation Example 2)
A hydrophilizing component (polyoxyethylene sorbitan monolaurate, HLB value 16.7, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) was dissolved in water to prepare a hydrophilizing agent aqueous solution having a concentration of 8.5% by weight.

(Preparation Example 3)
To 30 parts by weight of the fiber oil emulsion obtained in Preparation Example 1, 100 parts by weight of the aqueous hydrophilizing agent solution obtained in Preparation Example 2 was added and mixed to prepare a fiber oil agent-hydrophilizing agent mixture.

Example 1
A hydrophilic cellulose acetate tow band was produced using the apparatus shown in FIG.
Cellulose acetate having a substitution degree of 2.5 (L-50 manufactured by Daicel Corporation) is dissolved in acetone, discharged from the spinneret in a spinning cylinder, and the acetone solvent is volatilized to obtain cellulose acetate filaments. Cellulose acetate filaments were bundled into a rope shape to obtain cellulose acetate tow fiber yarn.
Next, the obtained cellulose acetate tow fiber yarn was treated with the fiber oil agent emulsion prepared in Preparation Example 1 using a roller type attaching device, and the fiber oil agent was applied (attached) to the fiber surface of cellulose acetate tow. . The amount of fiber oil applied was 0.5% by weight based on cellulose acetate tow.
Subsequently, a filament (cellulose acetate tow fiber yarn) is guided through a goded roll, and a plurality of filaments (cellulose acetate tow fiber yarn) from a plurality of spinning cylinders are converged to thereby concentrate a cellulose acetate tow band ( Tow band). The total denier of this tow band was 24,000. The filament denier was 3.3 (filament cross-sectional shape: Y-shape).
The tow band was treated with the hydrophilizing agent aqueous solution prepared in Preparation Example 2 using a roller-type attaching device to impart (attach) a hydrophilic component to the fiber surface of cellulose acetate tow. The amount of hydrophilic component added was 0.7% by weight based on cellulose acetate tow.
After that, crimping (crimping) is applied to the tow band to which the hydrophilic component has been added (crimping number: 36 pieces / inch), dried and bale-packed, and then the bale (packaging) of the cellulose acetate tow band that has been hydrophilized Body).
The obtained cellulose acetate tow band having been hydrophilized was subjected to a method (gas opening method) described in JP-A-2008-255529, and the cellulose acetate tow after opening was 2 g per 10 cm in width and 30 cm in length. The fiber sheet (thickness 1 cm) which consists of a cellulose acetate tow band hydrophilized was opened under such conditions.
A superabsorbent resin (trade name “Mooney Pants Type L”, collected from Unicharm Co., Ltd.) was sprayed at a weight of 250 g / m ² on the obtained fiber sheet and wrapped with tissue paper to produce an absorbent body. .

(Example 2)
Example 1 except that the amount of fiber oil was 0.4% by weight based on cellulose acetate tow and the amount of hydrophilic component was 0.3% by weight based on cellulose acetate tow. Thus, an absorbent body was produced.

(Example 3)
A hydrophilic cellulose acetate tow band was produced using the apparatus shown in FIG.
Cellulose acetate having a substitution degree of 2.5 (L-50 manufactured by Daicel Corporation) is dissolved in acetone, discharged from the spinneret in a spinning cylinder, and the acetone solvent is volatilized to obtain cellulose acetate filaments. Cellulose acetate filaments were bundled into a rope shape to obtain cellulose acetate tow fiber yarn.
Next, the obtained cellulose acetate tow fiber yarn is treated with the fiber oil agent-hydrophilizing agent mixture prepared in Preparation Example 3 using a roller-type attaching device, and the fiber oil agent and the fiber oil agent on the fiber surface of cellulose acetate tow A hydrophilic component was added (attached). The amount of fiber oil applied was 0.5% by weight based on cellulose acetate tow. The amount of hydrophilic component added was 0.4% by weight based on cellulose acetate tow.
Subsequently, a filament (cellulose acetate tow fiber yarn) is guided through a goded roll, and a plurality of filaments (cellulose acetate tow fiber yarn) from a plurality of spinning cylinders are converged to thereby concentrate a cellulose acetate tow band ( Tow band). The total denier of this tow band was 24,000. The filament denier was 3.3 (filament cross-sectional shape: Y-shape).
Next, the tow band is crimped (crimped) (crimp number: 36 / inch), dried and bale-packed to produce a bale (packaging body) made of a hydrophilic cellulose acetate tow band. did.
The obtained cellulose acetate tow band having been hydrophilized was subjected to a method (gas opening method) described in JP-A-2008-255529, and the cellulose acetate tow after opening was 2 g per 10 cm in width and 30 cm in length. The fiber sheet (thickness 1 cm) which consists of a cellulose acetate tow band hydrophilized was opened under such conditions.
A superabsorbent resin (trade name “Mooney Pants Type L”, collected from Unicharm Co., Ltd.) was sprayed at a weight of 250 g / m ² on the obtained fiber sheet and wrapped with tissue paper to produce an absorbent body. .

Example 4
A hydrophilic cellulose acetate tow band was produced using the apparatus shown in FIG.
Cellulose acetate having a substitution degree of 2.5 (L-50 manufactured by Daicel Corporation) is dissolved in acetone, discharged from the spinneret in a spinning cylinder, and the acetone solvent is volatilized to obtain cellulose acetate filaments. Cellulose acetate filaments were bundled into a rope shape to obtain cellulose acetate tow fiber yarn.
Next, the obtained cellulose acetate tow fiber yarn is treated with the fiber oil agent-hydrophilizing agent mixture prepared in Preparation Example 3 using a roller-type attaching device, and the fiber oil agent and the fiber oil agent on the fiber surface of cellulose acetate tow A hydrophilic component was added (attached). The amount of fiber oil applied was 0.6% by weight based on cellulose acetate tow. The amount of the hydrophilic component added at this stage was 0.4% by weight based on cellulose acetate tow.
Subsequently, a filament (cellulose acetate tow fiber yarn) is guided through a goded roll, and a plurality of filaments (cellulose acetate tow fiber yarn) from a plurality of spinning cylinders are converged to thereby concentrate a cellulose acetate tow band ( Tow band). The total denier of this tow band was 24,000.
The tow band was treated with a hydrophilizing agent aqueous solution prepared in Preparation Example 2 using a roller type attaching device, and a hydrophilic component was added (attached) to the fiber surface of cellulose acetate tow (attachment amount: cellulose acetate). 0.4% by weight with respect to tow). The total amount of hydrophilic component added was 0.8% by weight based on cellulose acetate tow.
After that, crimping (crimping) is applied to the tow band to which the hydrophilic component has been added (crimping number: 36 pieces / inch), dried and bale-packed, and then the bale (packaging) of the cellulose acetate tow band that has been hydrophilized Body).
The obtained cellulose acetate tow band having been hydrophilized was subjected to a method (gas opening method) described in JP-A-2008-255529, and the cellulose acetate tow after opening was 2 g per 10 cm in width and 30 cm in length. The fiber sheet (thickness 1 cm) which consists of a cellulose acetate tow band hydrophilized was opened under such conditions.
A superabsorbent resin (trade name “Mooney Pants Type L”, collected from Unicharm Co., Ltd.) was sprayed at a weight of 250 g / m ² on the obtained fiber sheet and wrapped with tissue paper to produce an absorbent body. .

(Comparative Example 1)
The absorbent body was manufactured in the same manner as in Example 1 except that the amount of fiber oil was 0.9% by weight based on cellulose acetate tow and that the treatment with the hydrophilic component was not performed.

(Comparative Example 2)
The same operation as in Example 1 was performed except that glycerin (HLB value 11.1) was used as the hydrophilic component and the amount of the hydrophilic component added was 0.4% by weight with respect to cellulose acetate tow. An absorber was manufactured. The amount of fiber oil applied was 0.5% by weight with respect to cellulose acetate tow, as in Example 1.

(Comparative Example 3)
The same as in Example 1 except that sorbitan monolaurate (HLB value 8.6) was used as the hydrophilizing component, and the amount of the hydrophilizing component added was 0.5 wt% with respect to cellulose acetate tow. The operation was performed to produce an absorber. The amount of fiber oil applied was 0.5% by weight with respect to cellulose acetate tow, as in Example 1.

(Comparative Example 4)
The same as in Example 1 except that polyoxyethylene lanolin (HLB value 13.0) was used as the hydrophilizing component, and the amount of the hydrophilizing component added was 0.5% by weight with respect to cellulose acetate tow. The operation was performed to produce an absorber. The amount of fiber oil applied was 0.5% by weight with respect to cellulose acetate tow, as in Example 1.

(Comparative Example 5)
In the same manner as in Example 1, a cellulose acetate tow band (tow band) (attachment amount of fiber oil: 0.5% by weight based on cellulose acetate tow) was produced. The total denier of this tow band was 24,000. The filament denier was 3.3 (filament cross-sectional shape: Y-shape).
The tow band was crimped (crimper treatment) (crimp number: 36 / inch) and dried. The obtained tow band is introduced into a roll set according to the method shown in FIG. 1 of JP 7-504233 A and passed through a stretching bath at 60 ° C. using a stretching ratio of about 1.2 to 1. Removed the crimp. Thus, after producing the tow band which consists of a non-crimped fiber, the said tow band is processed with the hydrophilizing agent aqueous solution prepared in Preparation Example 2 using a roller type attachment apparatus, and the fiber surface of cellulose acetate tow is made hydrophilic. The component was added (attached). The amount of hydrophilic component added was 0.7% by weight based on cellulose acetate tow.
Thereafter, the tow band provided with a hydrophilic component was cut into a length of 2 inches to produce cellulose acetate filaments with short fibers made hydrophilic.
The obtained short fiber hydrophilized cellulose acetate filaments were laminated under the condition of 7.5 g per 10 cm width and 30 cm length, and a fiber sheet (thickness 1 cm) comprising the hydrophilized cellulose acetate filaments was obtained. Obtained.
A superabsorbent resin (trade name “Mooney Pants Type L”, collected from Unicharm Co., Ltd.) was sprayed at a weight of 250 g / m ² on the obtained fiber sheet and wrapped with tissue paper to produce an absorbent body. .

(Comparative Example 6)
In the same manner as in Example 1, a cellulose acetate tow band (tow band) (attachment amount of fiber oil: 0.5% by weight based on cellulose acetate tow) was produced. The total denier of this tow band was 24,000. The filament denier was 3.3 (filament cross-sectional shape: Y-shape).
The tow band was treated with the hydrophilizing agent aqueous solution prepared in Preparation Example 2 using a roller-type attaching device to impart (attach) a hydrophilic component to the fiber surface of cellulose acetate tow. The amount of hydrophilic component added was 0.7% by weight based on cellulose acetate tow.
After that, the tow band to which the hydrophilic component is added is crimped (crimping) (crimp number: 36 pieces / inch), dried, and then cut to a length of 2 inches while applying sufficient tension to produce short fibers. Of hydrophilized cellulose acetate filaments. The number of crimps of the short fibers was 14 / inch.
The obtained short fiber hydrophilized cellulose acetate filaments were laminated under the condition of 7.5 g per 10 cm width and 30 cm length, and a fiber sheet (thickness 1 cm) comprising the hydrophilized cellulose acetate filaments was obtained. Obtained.
A superabsorbent resin (trade name “Mooney Pants Type L”, collected from Unicharm Co., Ltd.) was sprayed at a weight of 250 g / m ² on the obtained fiber sheet and wrapped with tissue paper to produce an absorbent body. .

(Reference example)
Superabsorbent resin (trade name “Mooney Pants Type L”, collected from Unicharm Co., Ltd.) on the surface of a fiber sheet (bulk specific gravity 0.025 g / cm ³ , thickness 1 cm) made of short pulp fibers (kraft pulp) ) Was sprayed at a basis weight of 250 g / m ² and wrapped with tissue paper to produce an absorbent.

<Evaluation test>
(Measurement of amount of hydrophilic component and fiber oil)
About 6 g of a cellulose acetate tow band to which a fiber oil agent and a hydrophilizing component are added [after crimping (however, Comparative Example 5 is after crimp release)] is weighed, dried at 105 ° C. for 1 hour, and then released. Cooled and weighed accurately. This was put into a Soxhlet extraction apparatus (manufactured by Asahi Seisakusho Co., Ltd.) to extract a fiber oil agent and a hydrophilic component. The extraction was performed by refluxing at 100 ° C. for 2 hours using 150 ml of a mixed solvent of hexane: ethyl acetate = 7: 3 (weight ratio) as an extraction solvent. After extraction, the solvent was removed by an evaporator, and further dried at 105 ° C. for 1 hour, and then the weight of the extract was measured. The weight of the extract was divided by the weight of the cellulose acetate tow subjected to extraction, and the total amount of the hydrophilic component and the fiber oil agent (% by weight; to cellulose acetate tow) was determined.
Next, the extract was dissolved in deuterated dimethyl sulfoxide (DMSO-d6), ¹ H-NMR analysis was performed, and the fiber oil agent and hydrophilic component were added by the calibration curve method from the signal intensity in the ¹ H-NMR spectrum. The amount (% by weight; to cellulose acetate tow) was determined.

(Evaluation of absorption performance)
Absorbers manufactured in Examples, Comparative Examples, and Reference Examples have a size of 10 cm × 30 cm (2 g of tow, 7.5 g of superabsorbent resin) (in the case of Comparative Examples 5 and 6, 7.5 g of tow, superabsorbent water) The resin was cut out by 7.5 g) and was hot-pressed for 1 minute under conditions of 100 ° C. and 3.5 MPa with a hot press to prepare an evaluation sample having a thickness of 2 mm.
A cylinder with an inner diameter of 6 cm was placed in the center of the evaluation sample so that the length direction was orthogonal to the surface of the evaluation sample, and 80 cc of physiological saline was injected into the cylinder. Simultaneously with the injection, the measurement of the absorption rate was started with a stopwatch, and the time when the physiological saline disappeared from the surface of the evaluation sample was defined as the water absorption time (80 cc water absorption) (unit: second). It can be said that the shorter the absorption time, the better the absorption speed.
Thereafter, 10 minutes after the first physiological saline injection, and 20 minutes later, another 80 cc of physiological saline was injected and absorbed by the absorber. After absorption, the length of the longest part in the longitudinal direction in the region diffusing on the absorber surface is measured by applying a ruler parallel to the absorber surface, and the plane diffusion length (240 cc water absorption) (unit: mm) It was. It can be said that the longer the planar diffusion length, the better the liquid diffusibility.

(Evaluation of water retention during tilting)
The absorber manufactured by the Example, the comparative example, and the reference example was cut out by the magnitude | size of 10 cm x 30 cm, and it was set as the evaluation sample.
The evaluation sample was fixed to the surface of the plate fixed at an inclination of 45 degrees so that the 10 cm side is the upper side, the lower side, and the 30 cm side is the right side and the left side. From a height of about 10 mm above the upper side of the evaluation sample, 80 cc of physiological saline (0.9% by weight) was dropped toward the upper end of the evaluation sample at a flow rate of 80 cc / min. The weight of physiological saline leaked from the lower end of the evaluation sample without being absorbed by the evaluation sample was measured to obtain water retention during tilting (80 cc water absorption) (unit: cc). It can be said that the smaller the amount of water leaking out in the water retention test at the time of inclination, the better the liquid retention.

  The evaluation results are shown in Tables 1 and 2. In Tables 1 and 2, “total amount of attachment” means the total amount of hydrophilic component attachment amount and fiber oil agent attachment amount.

DESCRIPTION OF SYMBOLS 1 Spinneret 2 Cellulose acetate tow fiber yarn 3 Textile oil agent grant apparatus 4 God dead roll (godi roll)
5 Guide 6 Tow Band Forming Means 7 Cellulose Acetate Tow Band 8 Hydrophilizing Component Applying Device 9 Crimp Applying Device

Claims (14)

  It is formed from cellulose acetate having a substitution degree of 2.0 to 2.6, and has a HLB value of 16 or more on the surface of the crimped cellulose acetate tow band having a total denier of 10,000 to 40,000 and a crimp number of 30 to 60 / inch. The hydrophilized cellulose acetate tow band is characterized in that 0.2 to 2% by weight of the hydrophilizing component is attached to the cellulose acetate tow band.   The hydrophilized cellulose acetate tow band according to claim 1, wherein the hydrophilizing component is attached to the cellulose acetate tow band in an amount of 0.25 to 2% by weight.   The hydrophilized cellulose acetate tow band according to claim 1, wherein the hydrophilizing component is attached to the cellulose acetate tow band in an amount of 0.3 to 2% by weight.   The hydrophilized component according to any one of claims 1 to 3, wherein the hydrophilizing component having an HLB value of 16 or more is at least one selected from polyoxyethylene sorbitan monolaurate and polyethylene glycol monostearate. Cellulose acetate tow band.   A fiber oil agent is attached to the crimped cellulose acetate tow band surface in an amount of 0.2 to 2% by weight with respect to the cellulose acetate tow band in addition to the hydrophilic component having an HLB value of 16 or more. The hydrophilic cellulose acetate tow band according to any one of the above.   6. The hydrophilic cellulose acetate tow band according to claim 5, wherein the total amount of the hydrophilizing component having a HLB value of 16 or more and the fiber oil agent is 0.4 to 3% by weight based on the cellulose acetate tow band.   The hydrophilic cellulose acetate tow band according to any one of claims 1 to 6, wherein a filament denier of the crimped cellulose acetate tow band is 1.0 to 7.0.   A fiber sheet formed from the hydrophilic cellulose acetate tow band according to claim 2 or 3.   The absorbent body characterized by disperse | distributing highly water-absorbing resin to the fiber sheet of Claim 8, and arrange | positioning. (A) A step of discharging cellulose acetate having a substitution degree of 2.0 to 2.6 dissolved in an organic solvent from a die with a spinning cylinder to obtain a cellulose acetate filament,
(B) A step of attaching a fiber oil agent to the obtained cellulose acetate filament,
(C) a step of attaching a hydrophilic component to the obtained cellulose acetate filament,
(D) combining cellulose acetate filaments obtained from a plurality of spinning cylinders to obtain a cellulose acetate tow band having a total denier of 10,000 to 40,000, and (E) crimping the cellulose acetate tow band, A method for producing a hydrophilic cellulose acetate tow band comprising a step of obtaining a crimped cellulose acetate tow band having a crimp number of 30 to 60 pieces / inch,
A method for producing a hydrophilic cellulose acetate tow band, wherein the hydrophilic component is attached to the cellulose acetate tow band in an amount of 0.2 to 2% by weight.   The method for producing a hydrophilic cellulose acetate tow band according to claim 10, wherein the hydrophilizing component is attached to the cellulose acetate tow band in an amount of 0.25 to 2% by weight.   The method for producing a hydrophilic cellulose acetate tow band according to claim 10, wherein the hydrophilizing component is attached to the cellulose acetate tow band in an amount of 0.3 to 2% by weight.   In the step (B), a hydrophilic component is attached to the obtained cellulose acetate filament together with the fiber oil agent. Then, in the step (C), the cellulose acetate filament to which the fiber oil agent and the hydrophilic component are attached is further hydrophilized. The method for producing a hydrophilic cellulose acetate tow band according to any one of claims 10 to 12, wherein components are attached.   The method for producing a hydrophilic cellulose acetate tow band according to any one of claims 10 to 13, wherein the steps are carried out in the order of step (B), step (D) and step (C).

Images