WO1999039036A2

WO1999039036A2 - Absorbents

Info

Publication number: WO1999039036A2
Application number: PCT/JP1999/000300
Authority: WO
Inventors: Naomichi Momoi; Noboru Watanabe; Hiroshi Onoue; Osayuki Numata
Original assignee: Kanebo Limited; Kanebo Gohsen Limited
Priority date: 1998-01-28
Filing date: 1999-01-26
Publication date: 1999-08-05
Also published as: WO1999039036A3

Abstract

A first absorbent comprising: synthetic fibers and/or natural fibers; water-absorbing fibers; and ultrafine fibers, characterized by being obtained by mixing all these fibers together, carding the mixture, and then needle-punching the carded mixture; a second absorbent which is a laminated nonwoven fabric comprising: synthetic fibers and/or natural fibers; and water-absorbing fibers, characterized by comprising one nonwoven fabric layer comprising fibers having a higher average fineness and another nonwoven fabric layer comprising fibers having a lower average fineness; and a third absorbent comprising flame-retardant fibers and (flame-retardant) water-absorbing fibers, characterized by being obtained by mixing all these fibers together, carding the mixture, and then needle-punching the carded mixture. The absorbents are excellent not only in liquid absorption but in liquid retention and dimensional stability. They are suitable for use as absorbents for ink-jet printers.

Description

Description Absorber Technical field

The present invention relates to an absorbent body made of a nonwoven fabric, and particularly to an absorbent body suitably used for an ink absorbent body of an ink jet printer. Background art

Conventionally, a nonwoven fabric mixed with a water-absorbent resin or a water-absorbent fiber has been widely used as an ink absorber for an ink jet pudding or the like. For example, Japanese Patent Application Laid-Open No. 08-311755 describes an absorbent in which an acrylic acid-based highly water-absorbent resin or fiber is mixed into a nonwoven fabric. However, since such an absorber is manufactured by an air-lay method, the entanglement of the fibers is weak and the swelling of the water-absorbent resin or the water-absorbent fiber at the time of liquid absorption is not suppressed. There is a disadvantage that.

In addition, since such an absorbent contains a water-absorbent resin or a water-absorbent fiber, the absorbent has a certain level of liquid absorbency in a free state, but when one end is lifted and tilted or when a centrifugal force is applied. There is a problem that the absorbed liquid cannot be retained and drops.

An object of the present invention is to provide an absorbent body which is excellent not only in liquid absorbency but also in liquid retainability and dimensional stability. Disclosure of the invention

The present inventors have studied the preparation of the materials constituting the absorber and the manufacturing method, and have completed the present invention. That is, the first of the present invention is an absorbent containing synthetic fibers and / or natural fibers, water-absorbent fibers, and ultrafine fibers, wherein the synthetic fibers and / or natural fibers, water-absorbent fibers, and ultrafine fibers are mixed, An absorbent body obtained by needle punching after carding. A second aspect of the present invention is an absorbent body in which a nonwoven fabric containing synthetic fibers and Z or natural fibers and a water-absorbent fiber is laminated, wherein one layer is a nonwoven fabric layer having a higher average fineness, An absorber characterized in that the layer is a nonwoven fabric layer made of fibers having a lower average fineness.

A third aspect of the present invention is an absorbent body containing a flame-retardant fiber and a (flame-retardant) water-absorbent fiber, wherein the flame-retardant fiber and the (flame-retardant) water-absorbent fiber are mixed, An absorber obtained by a needle punch. BEST MODE FOR CARRYING OUT THE INVENTION

The synthetic fibers and natural fibers which are the matrix fibers used in the present invention are not particularly limited. If synthetic fibers are used, for example, acrylic, modacrylic or polyolefins such as polypropylene or polyethylene, polyethylene terephthalate ポリエステル polyesters such as polybutylene terephthalate, polyamides such as nylon 6 or nylon 66 A polymer or the like can be used. Also, a mixture of two or more of these may be used.

When using natural fibers, for example, cellulose, wool, cotton, silk and the like can be used. Also, a mixture of two or more of these may be used. Examples of the water-absorbing fibers used in the present invention include fibers composed of carboxylic acids and alkali metal salts of carboxylic acids. The polymer comprises a monomer that provides a carboxylic acid group and a monomer that contains a hydroxyl group that reacts with the carboxylic acid group to form an ester crosslink. Acrylic acid and its water-soluble salts are used as monomers for providing a carboxylic acid group.

Examples of the monomer containing a hydroxyl group include vinyl alcohol, aryl alcohol, epoxide-substituted vinyl monomers, and hydroxyalkyl esters of vinyl carboxylic acid monomers. Specific compound names include hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, glyceryl monomethacrylate, glyceryl monoacrylate, and the like. Each of these monomers is A number of types may be used.

It is preferable that the monomer having a hydroxyl group is contained in an amount equal to or less than free acrylic acid of 0.5% by weight or more. When the content is 0.5% by weight or more, crosslinking proceeds sufficiently, and the strength of the fiber is maintained, so that the operability during the production of the nonwoven fabric is good.

In addition to the above monomers, other vinyl monomers such as vinyl acetate and acrylonitrile may be used to impart plasticity.

The method for polymerizing the above monomer is not particularly limited. As long as the monomer composition is water-soluble, aqueous polymerization is preferred. As a polymerization initiator, generally used sodium persulfate or the like may be used.

In the spinning method for producing the water-absorbent fiber used in the present invention from the above polymer, in the case of aqueous polymerization, dry spinning is preferable. In the case of wet spinning, water cannot be used as a coagulant, so an organic solvent system must be used.

After the dry spinning, the water content of the water-absorbent fiber is generally adjusted to 8 to 25% based on the dry weight of the fiber, and stretching, crimping, cutting, and the like are appropriately performed. When the moisture content is less than 8%, the strength of the fiber is insufficient and the fiber becomes brittle.

The water-absorbing fibers thus taken out undergo cross-linking of the polymer chain by heat treatment to make the polymer insoluble. First, these fibers are further dried to a moisture content of 0 to 10%, preferably 4 to 8%. Drying is carried out at a temperature below 100 ° C to avoid damage due to the formation of heated steam bubbles within the fiber structure. It is generally carried out by passing the fibers through a furnace at a temperature above 50 ° C, for example at 60 to 90 ° C.

Next, in a cross-linking step, heating is performed to cause sufficient cross-linking of the polymer chains to render the water-soluble polymer insoluble. The temperature at this time is generally in the range of 125 to 250 ° C. When an ester crosslink is formed by the reaction of the carboxylic acid and the hydroxyl group, the preferred temperature for the crosslink is at least 150 ° C or 160 ° C, and preferably no more than 25 ° C. If the temperature is below 150 ° C., the progress of crosslinking is slowed, so that the fiber may not have a predetermined gel strength at the time of absorbing water. If the temperature is higher than 25 ° C., the polymer may be deteriorated during the crosslinking step due to the high temperature. The time during which the crosslinking step takes place is generally in the range from 2 minutes to 2 hours, preferably between 5 and 15 minutes. When the time is less than 2 minutes, the gel strength at the time of predetermined water absorption may not be obtained as a fiber due to insufficient crosslinking in the polymer. On the other hand, if the time is longer than 2 hours, cross-linking in the polymer will increase, and the fiber may not have a predetermined water absorption.

The water absorption per unit weight of these water-absorbing fibers is preferably 10 g / g or more. When it is lOgZg or more, sufficient liquid absorption and liquid absorption retention as an absorber can be obtained.

An example of the water-absorbing fiber is "Bel Oasis" (trade name) manufactured by Technical Absorbent and imported and sold by Kanebo Synthetic Fiber Co., Ltd.

The mixing ratio of the water-absorbing fibers is preferably 5 to 40% by weight based on the whole nonwoven fabric. When the mixing ratio is within this range, it is preferable because the water absorption is excellent and the fibers do not fall off as much as the force dwell.

Furthermore, in the first aspect of the present invention, it is necessary to mix ultra-fine fibers in order to impart a liquid absorbing property. By mixing such microfibers, the liquid retention ability is increased, and an absorbent having both excellent liquid absorption properties and liquid absorption retention properties can be obtained.

The fineness of the ultrafine fibers used here is preferably less than 2 denier, more preferably less than 0.8 denier. It is preferable that the fineness is less than 2 deniers, because the effect by the capillary phenomenon is improved and excellent liquid absorption retention is exhibited. Here, the liquid-absorbing property refers to the liquid absorbing performance when the end of the absorber is lifted and tilted, or when a certain centrifugal force is applied.

The use ratio of the ultrafine short fibers having a density of less than 2 denier is preferably 5 to 40% by weight, and more preferably 10 to 30% by weight, based on the whole absorbent body. It is preferable that the content be in this range, because it shows excellent liquid absorption retention property and needle breakage during the production of the absorber is small.

The ultrafine short fibers having a density of less than 2 denier used in the present invention are not particularly limited, but conjugate fibers split by a physical method or a chemical method are preferable.

Examples of fibers split by physical means include polyethylene and polyethylene fiber. A fiber that combines a refuge rate into a star-shaped part and its foot part is commercially available

(Kanebo Synthetic Co., Ltd., trade name E91, etc.). Such a composite fiber is divided into five if the number of stars is four. Therefore, if the fineness of the conjugate fiber is 2 denier, the average fineness of the split fiber is 0.4 denier.

In addition, as fibers split by a chemical method, composite fibers composed of two components, ordinary PET and copolymerized PET that is easily dissolved by alkali treatment, are commercially available (Kanebo Synthetic Fiber Co., Ltd., trade name) NX 103).

Fibers split by the above physical method are split in the force dwell process and the needle punching process. Ideally, it is preferable not to divide in the carding process but to divide in the needle punching process. E91 (trade name) above is also excellent in this respect. Fibers split by chemical physical methods such as NX103 (trade name) are split by alkali treatment or the like in the process after they become products.

Other fiber materials to be mixed are not particularly limited. It may be appropriately selected depending on the application. General synthetic fibers, natural fibers and recycled fibers can be used.

In the method for producing an absorbent body comprising the above fibers, it is necessary to perform a needle punch after carding. That is, after opening and mixing cotton as a raw material, a web is produced through a card, and then a 21 dollar punch is used to produce a nonwoven fabric absorbent. Without the $ 21 punching process, the fibers in the absorber are less brittle and the swelling of the water-absorbing fibers during liquid absorption cannot be suppressed.

In addition, an absorbent body in which a nonwoven fabric containing synthetic fibers and / or natural fibers and a water-absorbing fiber is laminated, wherein one layer is a nonwoven fabric layer made of a fiber having a higher average fineness, and the other layer is made of a fiber having a lower average fineness. The absorbent (the claims 5 to 8), which is a nonwoven fabric layer made of fibers, also has the effect of increasing the liquid transfer speed while preventing liquid leakage from below the absorbent.

Synthetic fibers and / or natural fibers and water-absorbent fibers are opened and mixed, then passed through a card to produce a web, and needle punched to produce a nonwoven fabric absorbent. At this time, one layer is a nonwoven fabric layer composed of fibers with high average fineness, and the other layer is low in average fineness. It is necessary that the absorbent be a laminated nonwoven fabric layer made of fibers. By laminating non-woven fabrics having different average finenesses, it is possible to have both contradictory properties such as liquid absorbency and liquid absorbency.

In addition, it is possible to improve the liquid permeability in the lateral direction by using a nonwoven fabric layer made of fibers having a high average fineness. Furthermore, by suppressing the downward movement speed of the liquid by the nonwoven fabric layer made of fibers having a low average fineness, it is possible to prevent liquid leakage from the lower part of the absorber.

The average fineness in the nonwoven fabric layer composed of fibers having a high average fineness is preferably 2 denier or more. When the denier is 2 denier or more, the porosity in the nonwoven fabric is large, and the entanglement of the fibers is small, so that the swelling at the time of absorbing liquid in a free state is not suppressed, and sufficient liquid absorbing property as an absorber is obtained. Can be In addition, the transfer speed of the liquid is increased, and the permeability in the lateral direction in the absorber is increased. The mixing ratio of the water-absorbing fibers in the nonwoven fabric layer is preferably 5 to 40% by weight. When the mixing ratio is in this range, the liquid absorbing property is further improved, and the fibers do not fall off as much as in the force dwell, which is preferable.

Further, the average fineness in the nonwoven fabric layer made of fibers having a low average fineness is preferably less than 2 denier. If it is less than 2 deniers, sufficient absorbent retention as an absorber can be obtained due to the effect of capillary action. Furthermore, since the porosity is reduced and the downward moving speed of the liquid is suppressed, it is possible to prevent liquid leakage from the lower part of the absorber. Further, the mixing ratio of the water-absorbing fibers in the nonwoven fabric layer is preferably 5 to 40% by weight. When the mixing ratio is in this range, the liquid absorption retention property is further improved, and the fibers do not fall off in the force dwell, which is preferable.

In addition, the liquid-absorbing ability here refers to the liquid absorbing performance when one end of the absorber is lifted and inclined, or when a certain centrifugal force is applied.

It is also possible to mix ultra-fine fibers in the non-woven fabric layer made of fibers having a low average fineness. By mixing ultra-fine fibers of less than 2 denier, preferably less than 0.8 denier, an absorbent having more excellent liquid absorption retention can be obtained.

When such ultra-fine short fibers having a density of less than 2 denier are used, the use ratio is preferably from 5 to 40% by weight, more preferably from 10 to 30% by weight, based on the entire absorbent body. Content When the content is within this range, excellent liquid absorption retention properties are exhibited, and needle breakage during the production of the absorber is reduced, which is preferable.

The ultrafine short fibers of less than 2 denier used in the present invention are not particularly limited. For example, the composite fiber split by the physical method or the chemical method described above can be used.

By the way, the water-absorbing fiber of the present invention is also a flame-retardant fiber showing a high L 値 I value. For example, in the case of Bell Oasis, the value is about 42.

Therefore, by further mixing the flame-retardant fiber with the water-absorbent fiber, it becomes possible to obtain an absorber having excellent flame retardancy. More specifically, flame retardancy to the extent that it passes V0 of the flame retardant standard UL94 vertical test is obtained (claims 9 to 12). In recent years, from the viewpoint of enhancing the safety of electrical products, each component used in these components has been required to have performance such as flame retardancy, but it contains water-absorbing fiber and flame-retardant fiber. The absorber of the present invention can sufficiently satisfy such a demand.

In this case, the type of the flame-retardant fiber used is not particularly limited. For example, a type in which a fuel component is copolymerized can be used. Examples of this type of fiber include a halogen-containing component copolymerized polyester, a phosphorus-containing compound copolymerized polyester, and a halogen-containing component copolymerized acrylic. Alternatively, known flame-retardant fibers such as a type obtained by adding various organic and inorganic flame retardants to a polymer can be used. A composite type in which a flame retardant is added to a flame retardant polymer is also preferable.

These flame-retardant fibers preferably have an L 繊維 I value of 25 or more and a mixing ratio of 5 to 95% by weight. It is preferable that the content is within these ranges, since sufficient flame retardancy can be obtained as an absorber. When using a water-absorbing fiber other than Bell Oasis, its LOI value is preferably 25 or more.

It is also possible to mix other types of fibers as long as the flame retardancy to pass V0 of the UL94 vertical test is not impaired.

When manufacturing an absorbent body containing these flame-retardant fibers and (flame-retardant) water-absorbent fibers, it is necessary to perform needle punching after pressing. Specifically, the raw material cotton is opened and mixed, then the card is made through a card to produce a web. A non-woven fabric absorber is manufactured by punching. Without the needle punching step, the fibers in the absorber are weakly combined and the swelling of the water-absorbent fibers during liquid absorption cannot be suppressed, so the dimensional stability of the absorber is inadequate.

From the viewpoint of imparting excellent flame retardancy to the absorber, the mixing ratio of the flame retardant fibers is preferably 5% or more. Further, in order to obtain sufficient water absorption performance as an absorbent, the mixing ratio of the flame-retardant fiber is preferably 95% or less. Example

Hereinafter, the present invention will be described by way of examples. First, methods for measuring various physical properties of the fiber and the absorber will be described.

(Method of measuring water absorption of water-absorbing fiber)

Place 0.5 g of the water-absorbent fiber in a tea bag of 5 cm x 5 cm and immerse it sufficiently in ion-exchanged water. After taking out this and applying a load of 0.5 psi for 30 minutes to remove water in the fiber gap, the weight was measured to calculate the amount of water absorption per 1 g of the water-absorbing fiber.

(Method of measuring liquid absorption)

Samples were cut into 10 cm x 10 cm and weighed. This was sufficiently immersed in a liquid, and then allowed to stand on a 40-mesh wire gauze. After the zero was not dropped, the weight was measured, and the liquid absorption per 10 cm × 10 cm was obtained.

In the evaluation, when the liquid to be immersed was ion-exchanged water, ◎ was given when the amount of absorbed liquid was 150 g or more, Δ was given when the amount of absorbed liquid was 130 g or more and less than 150 g, and Δ was given when less than 130 g.

When the ink was immersed in a commercially available ink jet printer ink, the ink absorption was 80 g or more, ◎, 60 g or more and less than 80 g, Δ, and less than 608.

(Measurement method of liquid retention)

A string was passed through one end of a 10 cm x 10 cm sample whose liquid absorption was measured by the wire mesh method described above, lifted up and suspended vertically, and the liquid adhering between the fibers still remaining by the wire mesh method was further removed. Drop it off. The sample was allowed to stand as it was, and the weight was measured after zero was not dropped. Then, the liquid absorption retention was calculated from the ratio with the liquid absorption. The evaluation was evaluated as ◎ when the liquid absorption retention ratio was 85% or more, 〇 when 80% or more and less than 85%, and △ when less than 80% for both ion-exchanged water and commercially available ink jet printer ink.

(Method of measuring and evaluating dimensional stability)

At the time of the above-mentioned liquid absorption measurement, the thickness before liquid absorption and the thickness after liquid absorption were measured, and the swelling ratio of the volume was calculated and used as an index of dimensional stability.

Swelling ratio (%) = ((Thickness after liquid absorption-thickness before liquid absorption) Z Thickness before liquid absorption) XI 00 Evaluation is less than 10% ◎, 10% or more and less than 15% △, 15% or more △ was given. (Measurement method and evaluation method of lateral permeability and liquid leakage from the lower part of the absorber) Cut out a sample to 2 cm x 14 cm, and drop liquid at one end at a speed of lm1 / min. At this time, the time required for the liquid to reach a portion 10 cm from the dropping portion was measured and defined as a permeation time.

The evaluation was ◎ when the permeation time was less than 500 seconds, 〇 when 500 seconds or more and less than 1000 seconds, and △ when 1000 seconds or more.

When liquid leakage occurred from the lower part of the absorber, the time was also measured. The evaluation was ◎ when no liquid leakage occurred, 〇 when it occurred after 600 seconds or more, and △ when it occurred within 600 seconds.

(Method of measuring and evaluating flame retardancy)

Flame retardant standard UL 94 vertical test was performed. In the evaluation, V0 was rated as ◎, VI was rated as Δ, V2 as Δ, and burnt down as X.

Example 1 <Embodiments of Claims 1 to 4>

Example 11

Absorbers having the composition shown in Table 11 were manufactured by force reading, cross lay, and 21 dollar punch. The liquid absorption of this absorber with respect to ion-exchanged water was 161.2 g, and the liquid absorption retention was 96.4%. The ink absorption for commercially available ink-jet printer ink was 80.3 g, and the liquid absorption retention rate was 94.2%. The swelling ratio of these absorbers was less than 3% for both ion-exchanged water and the ink for ink jet pudding, and the dimensional stability was good. The evaluation results are shown in Tables 1-2. Example 11

Absorbers having the composition shown in Table 1-1 were manufactured by carding, cross lay, and 21 dollar punch. The absorption capacity of the absorber with respect to ion-exchanged water was 169.lg, and the absorption retention rate was 97.2%. The ink absorption for a commercially available ink for an ink jet printer was 85.40 g, and the liquid absorption retention rate was 96.1%. The swelling ratio of these absorbers was less than 3% for both ion-exchanged water and ink for ink jet printers, and the dimensional stability was good. The evaluation results are shown in Tables 1-2.

Comparative Example 11

Absorbers having the compositions shown in Table 11 were manufactured by carding, cross lay, and needle punch. The liquid absorption of this absorber with respect to ion-exchanged water was 134.lg, and the liquid absorption retention was 85.9%. In addition, the ink absorption amount for a commercially available ink jet printer ink is 70.8 g, and the liquid absorption retention rate is 84.7% .Therefore, the liquid absorption amount is small, and the absorbed ink drops slightly. Thousands occurred. The swelling ratio of these absorbers was less than 3% for both ion-exchanged water and ink for an ink jet printer, and the dimensional stability was good. The evaluation results are shown in Tables 1-2.

Comparative Example 1-2

Absorbers having the composition shown in Table 11 were manufactured by force reading, cross lay, and 21 dollar punch. The liquid absorption of this absorber with respect to ion-exchanged water was 136.8 g, and the liquid absorption retention was 88.0%. The ink absorption for a commercially available ink for an ink jet printer was 74.9 g, and the liquid absorption retention rate was 87.0%, indicating that some of the absorbed ink dripped off. The swelling ratios of these absorbers were less than 3% for both ion-exchanged water and ink for ink jet pudding, and the dimensional stability was good. The evaluation results are shown in Tables 1-2.

Comparative Example 11

Absorbers having the compositions shown in Table 11 were manufactured by carding, cross lay, and needle punch. The liquid absorption of the absorber with respect to ion-exchanged water was 130.2 g, and the liquid retention was 63.8%. Also, commercially available inkjet printer printers The liquid absorption amount for ink was 60.3 g, and the liquid absorption retention rate was 62.4%. The liquid absorption amount was small, and the absorbed ink dripped off frequently. The swelling ratio of these absorbers was less than 3% for both ion-exchanged water and ink for ink-jet pudding, and the dimensional stability was good. The evaluation results are shown in Tables 1-2.

[Table 1-1]

1 1 2]

Example 2 Claims 5 to 8 Embodiments>

Example 2-1

Ku upper mix>

A web having the composition shown in Table 2-1 was produced by force loading, cross lay, and a 21 dollar punch. The average fineness was 2.35 denier.

Mixing of lower layer>

A web having the composition shown in Table 2-1 was produced by carding, cross lay, and a 21 dollar punch. The average fineness was 1.71 denier.

Method for producing absorber>

The upper layer and the lower layer web were laminated, and a further 21 dollar punch was performed to produce an absorber. . The thickness was 4 mm for the upper layer and 4 mm for the lower layer. The thickness was 8 mm, and the basis weight was 1600 g / m ² .

The liquid absorption of the produced absorber with respect to ion-exchanged water was 138.8 g, and the liquid absorption retention was 88.0%. The liquid absorption of the commercially available ink for ink jet printing pudding was 76.4 g, and the liquid absorption retention was 86.0%. The swelling ratio of these absorbers was less than 3% for both ion-exchanged water and ink for inkjet printers, and the dimensional stability was good.

Furthermore, when the nonwoven fabric layer composed of fibers having a high average fineness was placed on the upper side, the permeation time was 630 seconds, and no liquid leakage from the lower part of the absorber occurred. Table 2-2 shows the results of these evaluations.

Comparative Example 2-1

Absorbers having the composition shown in Table 2-1 were manufactured by force-feeding, cross-laying, and 21 dollar punching. The average fineness was 2.35 denier.

The liquid absorption of the manufactured absorber of the present invention with respect to ion-exchanged water was 147.0 g, which was higher than the example, but the liquid absorption retention rate was 75.2%, which was lower than the example. In addition, the liquid absorption with respect to a commercially available ink for an inkjet printer was 79.2 g, which was higher than the example, but the liquid absorption retention was 74.1%, which was lower than the example. The swelling ratio of these absorbers was less than 3% for both ion-exchanged water and ink jet pudding ink, and the dimensional stability was good.

Furthermore, although the permeation time was 640 seconds, liquid leakage from the lower part of the absorber occurred after 390 seconds. Table 2-2 shows the results of these evaluations.

Comparative Example 2-2

Absorbers having the composition shown in Table 2-1 were manufactured by carding, cross lay, and 21 dollar punch. The average fineness was 1.71 denier.

The liquid absorption of the manufactured absorber of the present invention with respect to ion-exchanged water was 120.0 g, which was lower than that of the examples. The liquid retention rate was 89.0%. In addition, the amount of liquid absorbed with respect to a commercially available ink for an ink jet printer was 58.5 g, which was lower than the example. The liquid retention ratio was 88.4%. The swelling ratio of these absorbers is determined by Both ink jet pudding inks are less than 3% and have good dimensional stability.

Furthermore, the permeation time was 1020 seconds, which was much slower than that of Example 2-1. No liquid leakage from the lower part of the absorber occurred. Table 2-2 shows the results of these evaluations.

[Table 2-1]

Example 3 Embodiment of Claims 9 to 12>

Example 3-1

Absorbers having the composition shown in Table 3-1 were manufactured by carding, cross lay, and 21 dollar punch. The liquid absorption of the absorber with respect to ion-exchanged water was 163.2 g, and the liquid absorption retention was 94.3%. The liquid absorption for a commercially available ink jet pudding ink was 80.3 g, and the liquid retention was 96.0%. Also these The swelling ratio of the absorber of both ion-exchanged water and ink for inkjet printers

It was less than 3%, and the dimensional stability was good.

Furthermore, the flame retardancy (flame retardant standard UL 94 vertical method) as the absorber was V0, the best result. Table 3-1 shows the results of these evaluations.

Example 3-2

Absorbers having the composition shown in Table 3-1 were manufactured by force-feeding, cross-laying, and needle punching. The liquid absorption of this absorber with respect to ion-exchanged water was 168.2 g, and the liquid retention was 94.4%. The liquid absorption for a commercially available ink jet printer ink was 82.4 g, and the liquid absorption retention rate was 96.2%. The swelling ratio of these absorbers was less than 3% for both ion-exchange water and ink for inkjet printers, and the dimensional stability was good.

Comparative Example 3-1

Absorbers having the composition shown in Table 3-1 were manufactured by carding, cross lay, and 21 dollar punch. The liquid absorption of the absorber with respect to ion-exchanged water was 125.2 g, and the liquid absorption retention was 76.8%. The liquid absorption amount for a commercially available ink jet printer ink was 50.2 g, and the liquid absorption retention rate was 75.2%. The swelling ratio of these absorbers was less than 3% for both ion-exchanged water and ink jet printing pudding ink, and the dimensional stability was good.

Furthermore, the flame retardancy (flammability standard UL 94 vertical method) as the absorber was V0, which was a good result. Table 3-1 shows the results of these evaluations.

Comparative Example 3-2

Absorbers having the composition shown in Table 3-1 were manufactured by force-feeding, cross-laying, and needle punching. The liquid absorption of the absorber with respect to ion-exchanged water was 140.0 g, and the liquid absorption retention was 82.1%. The liquid absorption with respect to a commercially available ink for an ink jet printer was 60.9 g, and the liquid absorption retention rate was 81.8%. In addition, the swelling ratio of these absorbers is the same for both ion-exchanged water and ink-jet pudding ink. It was less than 3%, and the dimensional stability was good.

However, the flame-retardant properties of the absorber (flame-retardant standard UL 94 vertical method) were burnt down due to the candle burning phenomenon. Table 3-1 shows the results of these evaluations.

About 3—1]

Industrial applicability

INDUSTRIAL APPLICABILITY The present invention is an absorber excellent not only in liquid absorbency but also in liquid absorbability and dimensional stability, and is suitably used as an ink jet type pudding absorber.

Claims

The scope of the claims

1. An absorbent material containing a synthetic fiber and / or Z or a natural fiber, a water-absorbent fiber and an ultrafine fiber, wherein the synthetic fiber and / or the natural fiber, the water-absorbent fiber and the ultrafine fiber are mixed, and the needle An absorber obtained by punching.

2. The absorbent body according to claim 1, wherein the water-absorbing fiber has a water absorption of 10 g Z g or more.

3. The absorber according to claim 1 or 2, wherein the mixing ratio of the water-absorbing fibers is 5 to 40% by weight.

4. The absorber according to any one of claims 1 to 3, wherein the fineness of the ultrafine fibers is less than 2 denier, and the mixing ratio is 5 to 40% by weight.

5. Absorbent laminated with non-woven fabric containing synthetic fiber and Z or natural fiber and water-absorbing fiber, one layer of non-woven fabric layer with higher average fineness, the other layer with lower average fineness An absorbent body, which is a nonwoven fabric layer made of fibers.

6. The absorbent body according to claim 5, wherein an average fineness of the nonwoven fabric layer made of the fiber having a higher average fineness is 2 denier or more, and a mixing ratio of the water-absorbing fibers is 5 to 40% by weight.

7. The absorbent body according to claim 6, wherein an average fineness of the nonwoven fabric layer made of fibers having a lower average fineness is less than 2 denier, and a mixing ratio of water-absorbing fibers is 5 to 40% by weight.

8. The absorber according to any one of claims 5 to 7, wherein the water-absorbing fiber has a water absorption of 10 gZg or more.

9. An absorbent body containing a flame-retardant fiber and a water-absorbent fiber, wherein the flame-retardant fiber and the water-absorbent fiber are obtained by blending, pressing, and punching with a $ 21 punch. body.

10. The absorbent body according to claim 9, wherein the L0I value of the flame-retardant fiber is 25 or more, and the mixing ratio is 5 to 95% by weight.

11. The absorbent body according to claim 9, wherein the water absorbent fiber has an LOI value of 25 or more.

12. The water-absorbing fiber according to claim 9, wherein the water-absorbing fiber has an amount of water absorption of at least 10 g Z g. An absorber according to any of the above items.