CN1478164A - Cellulose fibers having low water retention value and low capillary desorption pressure - Google Patents

Abstract

The present invention provides cellulose fibers having low median desorption pressures and low water retention values (WRV), which exhibit improved drainage and fluid flow properties. These fibers are particularly well suited for use in acquisition, distribution, and acquisition-distribution layers, or in absorbent core structures. One embodiment of the invention is a method for preparing cellulose fibers by refining cellulose fibers to a freeness ranging from about 300 to about 700 ml CSF and crosslinking the refined fibers. Another embodiment of the invention is fibers crosslinked with at least one saturated dicarboxylic acid, aromatic dicarboxylic acid, cycloalkyl discarboxylic acid, bifunctional monocarboxylic acid, or amine carboxylic acid. A crosslinking facilitator, such as oxalic acid, may be present during the crosslinking reaction to improve the efficacy of the crosslinking agent. Yet another embodiment of the invention is an absorbent core comprising SAP particles and reversible crosslinked fibers.

Description

Cellulose fibre with low water retention value and low capillary desorption pressures

The application requires the U.S. Provisional Application No.60/247 that proposed on November 10th, 2000, and 078 and the U.S. Provisional Application No.60/286 that proposes April 25 calendar year 2001,298 right, it is for referencial use all to incorporate them into this paper.

Invention field

The present invention relates to have the cellulose fibre of low water retention value and low intermediate value desorption pressures (in capillary absorption-desorption cycle, measuring), prepare the method for these fibers, and the absorbing structure that contains these fibers.

Background of invention

Absorbing structure is important in various disposable absorbent articles (comprising baby diaper, adult's gatism articles for use, sanltary towel and other women sanitary articles etc.).Provide absorbent core so that hold and keep body fluid for usually these and other absorbing products.In a kind of conventional absorbing structure, absorbent core is placed between liquid infiltration top layer (its effect is to allow liquid pass through, and enters into described core) and the liquid impermeability back sheet (its effect is to hold fluid and prevent that it from seeing through on the clothes that absorbent article flows to the absorbent article wearer).

Diaper, adult's gatism pad and the used absorbent core of women sanitary articles generally include by de-fibering, loose, the fibrofelt or the width of cloth soft, that hydrophilic cellulose fibre constitutes.Such fibrofelt forms the base material that can absorb and keep some liquid.Yet their this ability is limited.So superabsorbent polymer (SAP) particulate, particle, sheet or the fiber (particulate of gathering) that usually can absorb a lot of liquid doubly of their own wts are contained in the absorbent core, increasing the absorbability of core, but needn't enlarge markedly the volume of core.In the absorbent core that contains matrix fiber and SAP particulate, described fiber provides the structural intergrity of absorbent core with SAP particulate physical isolation, and provides passage for fluid flows through core.

The absorbent core that contains the SAP particulate has obtained success, and in recent years, increasing for the market demand of the absorbent article thinner, that absorbability is stronger and more comfortable.Along with the enhancing of core absorbability, core has become very important from the ability of the rapid withdrawn fluid in absorbent article top layer for the skin of the wearer that keeps absorbent article and the dry environment between the goods top layer.

Absorbent core is from being positioned at above it the control that is subjected to following factors near its ability of layer withdrawn fluid absorbing structure: gravity, do not account for quantity, size and the spatial orientation of volume (space or hole) in the absorbent core and influence the core component characteristic that fluid flows, for example by contact angle represent the fluid that receives to the surface tension of the wettability of component, the fluid that receives and the viscosity of the fluid that receives.In absorbing structure, between top layer and absorbent core, can comprise an acquisition layer, Distribution Layer or collection and Distribution Layer to promote the importing of fluid to absorbent core.

In order to obtain absorbing structure in the optimum performance aspect fluid displacement and the core usability, the dry section of crucial is fluid that absorbent core receives moves to rapidly from the wetted area of core core.Can absorbent core is moved to fluid the dry section of core from the wetted area of core ability be described with permeability.The permeability of absorbent core is defined as the ability that liquid flows through absorbent core.

First base material (for example, absorbent core) is called as the partition characteristic of base material mainly by the ability of capillary force by second base material (for example, gathering and Distribution Layer) withdrawn fluid.

It is known to those skilled in the art that the absorbing structure that comprises the absorbent core with good fluid partition characteristic also shows poor fluid permeability.Equally, the fluid partition characteristic that has the absorbing structure performance difference of good fluid permeability.Therefore, importantly, under the body weight of diaper wearer, the fiber that is used for acquisition layer has higher hardness or resiliency (being measured by the dry-pressing shrinkage) than the conventional fibre that is used for absorbent core.This rebound performance makes that space or hole can be held between the fiber in the acquisition layer, so fluid can be absorbed into rapidly in the absorbing structure of diaper by the top layer of fluid permeable when dressing diaper.

It is also important that when soaking, core fibre can not be dense to the degree that limit fluid flowed into and flow through absorbent core.In addition, core fibre must have enough physical integrities keeping the separation of wet SAP particulate in the absorbent core, thereby along with the swelling of described particulate, minimizes or eliminate the gel sealing process.

A kind of hardness of increased fiber and the method for resiliency are that they are crosslinked.Cellulose fibre can join (that is, between two different pieces of same fiber crosslinked) hardening by intrafiber crosslink, and by crosslinked between fiber (that is, between two different fibers crosslinked) hardening on littler degree.

Disclose in the U.S. Patent No. 5,190,563 of Herron etc. with some aliphatic series and alicyclic C authorizing ₂～C ₉The intramolecular crosslinking of polybasic carboxylic acid." the C of definition such as Herron ₂～C ₉Polybasic carboxylic acid " be a kind of organic acid, during it comprises two or more carboxyls and is in the chain that is connected carboxyl or the ring on 2～9 carbon atoms.Appropriate C ₂～C ₉Polybasic carboxylic acid contains at least three carboxyls or two carboxyls, has a carbon-to-carbon double bond in α, the β position of one or two carboxyl.When two carboxyls were isolated by a carbon-to-carbon double bond or all are connected on the identical ring, these two carboxyls must be cis-configuration.The example of such polybasic carboxylic acid comprises: citric acid, 1,2,3-tricarballylic acid, 1,2,3,4-butanetetra-carboxylic acid (BTCA) and oxygen di-succinic acid.Herron etc. also find, with the aliphatic alkane that contains 4 carboxyls be BTCA cross-linked cellulosic ratio to contain 3 carboxyls be citric acid and 1,2, tricarboxylic those of 3-alkane have lower water retention value.Usually, it is harder than those fibers with higher water retention value to have a fiber of lower water retention value.

Different with the cellulose fibre with intrafiber crosslink connection point, the cellulose fibre (for example, seeing in most of paper those) with crosslinking points between fiber is hard when drying, but not necessarily keeps their hardness when moistening.Disclose with citric acid and 1,23 in the following document, crosslinked and with maleic acid, citric acid and 1,2,3 between the fiber of the paper that the 4-butanetetra-carboxylic acid carries out, crosslinked between the fiber of the fabric that the 4-butanetetra-carboxylic acid carries out: D.F.Caulfield, TAPPI J., 77 (3): 205～212 (1994); D.Hcrie﹠amp; C.J.Biermann, TAPPI J., 77 (8): 135～140 (1994); Y.J.Zhou, P.Luner﹠amp; P.Caluwe, journal of applied (J.Appl.Polymer Sci.), 58:1523～1534 (1995); And D.D.Gagliardi and F.B.Shippee, american dye report (Am.Dyestuff Reptr.), 52:300 (1963).

Zhou etc. (seeing above) have studied the wet strength with the paper of some polycarboxylic acid crosslinked (between fiber).Usually, the crosslinked wet strength that increases the paper fiber between fiber.Discoveries such as Zhou, the wet strength of paper increases along with the increase of polybasic carboxylic acid degree of functionality (that is the carboxyl number in the polybasic carboxylic acid).For example, find 1,2,3,4-butanetetra-carboxylic acid (BTCA) (4 carboxyls) is more effective than tricarballylic acid (TCA) (3 carboxyls), and tricarballylic acid is obviously more effective than succinic acid (2 carboxyls).The paper of handling with succinic acid shows very little wet strength.

H.J.Campbell and T.Francis, textile research magazine (Textile Res.J.), 35:260 (1965) is with specific polycarboxylic acid crosslinked gossypin.This reaction needs to use nonaqueous solvents (using benzene in this example) in order to avoid the TFAA hydrolysis with TFAA (TFAA) catalysis.Campbell and Francis have reported succinic acid and glutaric acid only shows slight activity to gossypin.In addition, they have reported with oxalic acid esterification (or crosslinked) have not taken place.Find the easy and gossypin reaction of malonic acid, produce the fabric that the yellowing degree depends on degree of reaction.

Usually, cross-linked cellulose fibres are to produce away from the place that they is incorporated into absorbing structure.Because crosslinked fiber volume is big and fiber contacts for a short time with interfibrous, they are combination well each other.Like this, the sheet material that forms from cross filament scatters easily.Therefore, usually that the big contracted affreightment of cross-linked cellulosic is defeated.This has increased the expense of shipment cross filament and the expense of producing absorbing structure.Therefore, wish that preparation contains the sheet material of the cellulose fibre of crosslinking agent.

" crosslinkable " cellulose fibre that is processed into coiled material or sheet material is disclosed among the international publication number WO 00/65146.This crosslinkable product is to produce like this: crosslinking agent is coated on the cellulose fibre felt, again the felt of dry this processings (but not being heated to the temperature that is enough to make crosslinking agent curing) consequently do not take place basically crosslinked, so product does not have crosslinking points basically.

U.S. Patent No. 6,059,924 disclose the contract method of characteristic and capillary properties of a kind of dry-pressing that strengthens loose paper pulp.This method comprises, is forming the suitably refining in the past chemical pulp of loose paper pulp sheet.

People need such fibres modified cellulose fiber always: they have low water retention value and low intermediate value desorption pressures, can be incorporated into acquisition layer, Distribution Layer and collection-Distribution Layer.Also need such core or matrix fiber, it can impel fluid to flow into and flow through absorbent core and keep enough physical integrities and minimize or eliminate the gel sealing of the SAP particulate of swelling.At last, the method that needs the sheet material of preparation crosslinkable cellulose fibre.

Summary of the invention

The invention provides the cellulose fibre with low intermediate value desorption pressures (measuring in capillary absorption-desorption cycle) and low water retention value (WRV), they show the drain performance and the fluid mobility energy of improvement.These fibers are specially adapted in acquisition layer, Distribution Layer and the collection-Distribution Layer, and are applicable in the absorbent core structures.

By an embodiment, fiber of the present invention is crosslinked and has 15cm or a littler intermediate value desorption pressures (measuring) in capillary absorption-desorption cycle.Preferably, described cellulose fibre also has 45% or littler WRV.These fibers can prepare like this: cellulose fibre is refined to the interior beating degree of about 300～about 700ml canadian standard freeness (CSF) scope, and again that refining fiber is crosslinked.By an embodiment preferred, refining back citric acid cross filament.

Another embodiment of the invention is with at least a saturated dicarboxylic acid, aromatic dicarboxylate, cycloalkyl dicarboxylic acids, difunctionality monocarboxylic acid or the crosslinked fiber of amine carboxylic acid.In the cross-linking reaction process, can there be a kind of crosslinking accelerator such as oxalic acid, to improve the efficient of crosslinking agent.By an embodiment preferred, refined fiber cellulose fiber before crosslinked is so that further harden them.

Another embodiment is a kind of method for preparing crosslinkable cellulose fibre, it comprises the steps: (a) with being selected from least a crosslinking agent cross-linked cellulose fibres in saturated dicarboxylic acid, aromatic dicarboxylate, cycloalkyl dicarboxylic acids, difunctionality monocarboxylic acid and the amine carboxylic acid, and (b) cross-linked cellulosic is separated crosslinked.Preferably, the crosslinking agent in this embodiment contains 4 or carbon atom still less.Two kinds of preferred cross-linking agents are oxalic acid and sodium chloroacetate.Crosslinkable fiber process can be become sheet material and be convenient to their transportation.In addition, crosslinkable fiber can be separated cross-linked cellulosic and crosslinked again by curing.

Another embodiment of the present invention is acquisition layer, Distribution Layer or collection and the Distribution Layer that comprises cellulose fibre of the present invention.

Another embodiment is the absorbent core that comprises cellulose fibre of the present invention.This absorbent core shows the fluid inflow of improvement and flows through the mobile performance of core.By an embodiment preferred, absorbent core comprises SAP particulate and reversible crosslink fiber.The reversible crosslink fiber with the SAP particulate separately and is walked around the SAP particulate for fluid and is flowed to dry section from the humid region of absorbent core passage is provided.In addition, the reversible crosslink fiber helps at short notice (for example, once gushing out) a large amount of urine of absorption (or other fluids).In case urine or other fluid enter absorbent core, crosslinked fiber just begins to separate crosslinked.Separate crosslinked fiber and hold and keep urine or other fluid to a greater degree than for good and all crosslinked fiber.As a result, described absorbent core has the capacity of initially gushing out than the absorbent core improvement that contains conventional loose fiber, and has the wetting characteristics again than the absorbent core improvement that contains permanent crosslinked fiber.

Another embodiment is a kind of absorbing structure, and it comprises acquisition layer of the present invention, Distribution Layer or collection and Distribution Layer and/or absorbent core of the present invention.Preferably, described absorbing structure comprises: top layer (acquisition layer, Distribution Layer or collection and Distribution Layer) and with the bottom of top layer fluid communication (storing layer).Compare with conventional absorbing structure, described absorbing structure shows from acquisition layer and/or Distribution Layer and is assigned to the good distribution performance that stores layer.

Another embodiment is a kind of absorbent article that comprises absorbing structure of the present invention. Detailed Description Of The Invention Definition

Term " capillary absorption-desorption cycle " (being also referred to as capillary sorption cycle or CSC) is meant that being determined at liquid-absorbent goes into absorbing structure and the method for correlation between the pore volume of absorbing structure and the capillary pressure in the liquid process of discharging subsequently from absorbing structure.Capillary absorption-desorption cycle has been indicated the ability of distributing fluids in absorbing structure attraction, maintenance and the hole between the fiber of absorbing structure.Absorbing structure can by systematically reduce or the narrow gap that raises in capillary pressure experience this circulation, for example measure: " the capillary adsorption equilibrium in the fibrous matter " by the method described among the application's the embodiment and in the following document, A.A.Burgeni and C.Kapur, the textile research magazine, 37:356～366 (1967); And P.K.Chatterjee, Absorbability, textiles Science and Technology 7 (Textile Science and Technology 7), the II chapter, pp.63～65, Elsevier Science Publishers (1985), it is for referencial use to incorporate them into this paper.

The water-soluble bloated cellulose fibre of " intermediate value desorption pressures " expression of measuring in capillary-desorption cycle discharges the ability of water.For example, the cellulose fibre sample of water conservation shows much higher intermediate value desorption pressures than the fiber sample of swollen cellulose that discharges water easily consumingly.The intermediate value desorption pressures of Tao Luning is that the method for describing in embodiment by the application and the following document is measured: " the capillary absorption equilibrium in the fibrous matter ", A.A.Burgeni and C.Kapur, textile research magazine, 37:356～366 (1967) herein; And P.K.Chatterjee, Absorbability, textiles Science and Technology 7, the II chapters, pp.63～65, Elsevier SciencePublishers (1985), it is for referencial use to incorporate them into this paper.This test determines water-soluble bloated cellulose fibre under hydrostatic pressing, keep the ability of water.

" water retention value " of cellulose fibre (WRV) can be measured by the method for describing in the following document: TAPPI Useful Methods, and UM 256, and P.K.Chatterjee, Absorbability, TextileScience and Technology Z, the II chapter, pp.62～63, Elsevier SciencePublishers (1985), it is for referencial use to incorporate them into this paper.This test determination the weight of the water that keeps in centrifugal back of water saturated cellulose fibre sample, and to express this amount based on the percetage by weight of fiber dry weight.The WRV of cellulose fibre relates to its drainability.

Any " cellulose fibre " known in the art comprises the cellulose fibre (for example be derived from wood pulp those) of any natural source can being used as the raw material in the inventive method.Preferred cellulose fibre includes but not limited to, the boiling fiber, for example be derived from the sulfate paper pulp fibres of cork, hardwood or velveteen, the sulfate paper pulp fibres of prehydrolysis, soda pulps fiber, sulfite pulp fiber, the chemistry-fiber of Re mechanical treatment and the fiber of hot mechanical treatment.Preferred cellulose fibre includes but not limited to, the sulphate cook fiber comprises the phosphate boiling fiber of prehydrolysis.

Usually, the cellulose fibre with thicker wall is preferred, because they are more coarse and harder than the like fibrous with thinner wall.The fibre wall of fiber is limited by the chamber (being the hollow interior of fiber) and the outer surface of fiber of fiber.For example, because the fibre wall of the fibre wall average specific northern softwood of southern softwood is thicker, so the fiber that is derived from southern softwood is preferred.More preferably, described cellulose fibre is derived from cork, for example, and pine tree, fir and dragon spruce.

Other suitable cellulose fibre comprises, is derived from those of the wooden and cellulose fibre source of needle Rhizoma Imperatae (Esparto grass), bagasse, kemp, flax and other.Cellulose fibre can be slurry, form compressing tablet or compressing tablet provides.

Combine the concrete final use that the suitableeest fibre source of using will depend on expection with the present invention.Usually, the paper pulp fiber by chemical beating method preparation is preferred.Full bleaching, all can the using of partial bleaching with unbleached fiber.May wish to utilize the slurry of bleaching usually, because it has good whiteness and to consumer's attraction.With regard to product, for example paper handkerchief and be used for the absorption pad of diaper, sanitary napkin, sanitary towel, and other similar absorbent paper article preferably especially uses the cellulose fibre that is derived from the southern softwood slurry, because they have excellent absorption characteristic.

Preferred cellulose fibre includes but not limited to, with trade name Foley Fluff ^TMThe sulfate southern pine fiber of the bleaching of selling, they can derive from Buckeye TechnologiesInc.of Memphis, TN.

Cellulose fibre can have any fibre length.Usually, the cross-linked cellulose fibres of long fiber production than having lower desorption pressures and water retention value from those of short fiber production.

Refining and crosslinked fiber

The inventor is surprised and be surprised to find that after cellulose fibre was made with extra care and be crosslinked, the fiber of generation had low intermediate value desorption pressures (measuring) and low water retention value (WRVs) in capillary absorption-desorption cycle.In addition, with similarly not refined fiber compare, these fibers show the discharge opeing that improves in acquisition layer and/or Distribution Layer.

Described cellulose fibre is crosslinked and has 15cm or a littler intermediate value desorption pressures (measuring) in capillary absorption-desorption cycle.Be not bound by any theory, the inventor believes that this performance is the result of the intrafiber crosslink connection in the cellulose fibre.More desirably, cellulose fibre of the present invention has 14cm or littler intermediate value desorption pressures (measuring) in capillary absorption-desorption cycle; Wish that further fiber of the present invention has 13cm or littler intermediate value desorption pressures (measuring) in capillary absorption-desorption cycle; Wish that more more fiber of the present invention has 12cm or littler intermediate value desorption pressures (measuring) in capillary absorption-desorption cycle.

Refining and cross-linked cellulosic has 45% or littler WRV usually; Better is 38% or littler; More better is 30% or littler.

Above-mentioned cellulose fibre can prepare like this: the refined fiber cellulose fiber is to the interior beating degree of about 300～about 700mlCSF scope, and is again that refining fiber is crosslinked.By an embodiment preferred, the original fibers cellulose fiber of being made with extra care is wet lap.By another embodiment preferred, before refining, cellulose fibre bleaching and/or evacuation are opened.Refining fiber can be crosslinked by any method known in the art, for example, and by making the reaction of fiber and crosslinking agent.

Having the intermediate value desorption pressures of improvement and the fiber of water retention value can prepare like this: refined fiber at first makes fiber crosslinked with any of various crosslinking agents then.Suitable crosslinking agent includes but not limited to those and other polybasic carboxylic acid described below, for example aliphatic series and alicyclic C ₂～C ₉Polybasic carboxylic acid.Term " C used herein ₂～C ₉Polybasic carboxylic acid " be meant contain two or more carboxyls (COOH) and be positioned at the chain that is connected carboxyl or ring on the organic acid of 2～9 carbon atoms.When the carbon number of determining chain or encircling, do not comprise carboxyl.For example, 1,2, the 3-tricarballylic acid should be counted as the C that contains three carboxyls ₃Polybasic carboxylic acid.Equally, 1,2,3, the 4-butanetetra-carboxylic acid should be regarded the C that contains four carboxyls as ₄Polybasic carboxylic acid.

Be suitable for and make C of the present invention cellulose crosslinked dose ₂～C ₉Polybasic carboxylic acid preferably includes, saturated or unsaturated aliphatic series of olefinic and alicyclic acid, and per molecule contains at least three, and preferred a plurality of carboxyls are if there are carbon-to-carbon double bond in the α of one or two carboxyl, β position.In addition, in order to be reactivity when the esterified cellulose hydroxyl, a given carboxyl in the aliphatic or alicyclic polybasic carboxylic acid preferably is separated by with second carboxyl and is no less than two carbon atoms and no more than three carbon atoms.As if without being limited by theory, but in order to make carboxyl be active, it must form a ring-type 5 or 6 yuan of anhydride rings with adjacent carboxyl in this polybasic carboxylic acid molecule.Isolated by carbon-to-carbon double bond or two carboxyls all are connected under the situation on the same ring at two carboxyls, if they think to interact by this way, these two carboxyls must be cis-configuration each other.

Novel cross filament

Another embodiment of the invention is that it shows low intermediate value desorption pressures (measuring) and low water retention value in capillary absorption-desorption cycle with at least a saturated dicarboxylic acid, aromatic dicarboxylate, cycloalkyl dicarboxylic acids, difunctionality monocarboxylic acid or amine carboxylic acid cross-linked cellulosic.These cross filaments show discharge opeing that improves and the permeability that improves in absorbent core in acquisition layer and/or Distribution Layer.

Usually, these cross-linked cellulose fibres have 25cm or littler intermediate value desorption pressures (measuring) in capillary absorption-desorption cycle.Be not bound by any theory, it is believed that this performance is the result of the intrafiber crosslink connection in the cellulose fibre.

More desirably, described cross-linked cellulose fibres have 20cm or littler intermediate value desorption pressures (measuring) in capillary absorption-desorption cycle; More it is desirable for these fibers and have 18cm or littler intermediate value desorption pressures (in capillary absorption-desorption cycle, measuring); Further it is desirable for these fibers and have 15cm or littler intermediate value desorption pressures (in capillary absorption-desorption cycle, measuring); More more it is desirable for these fibers and have 14cm or littler intermediate value desorption pressures (in capillary absorption-desorption cycle, measuring); Further it is desirable for these fibers and have 13cm or littler intermediate value desorption pressures (in capillary absorption-desorption cycle, measuring); Have 12cm or littler intermediate value desorption pressures (in capillary absorption-desorption cycle, measuring) and also further it is desirable for these fibers.

These cross-linked cellulose fibres have 50% or littler WRV usually; More wish it is 45% or littler; Further wish it is 38% or littler; And more desirably be 30% or littler.

Described cross-linked cellulose fibres have the saturated capacity of at least 10 gram every gram samples of salt solution (g/g) usually, and this saturated capacity is by the embodiment in the application; Burgeni etc., preamble; With Chatterjee etc., the method for describing in the preamble is measured.By an embodiment preferred, described cross-linked cellulose fibres have at least 11,12,13,14 or the saturated capacity of 15g/g.

Cross-linked cellulose fibres of the present invention are by preparing with one or more crosslinking agent cross-linked cellulose fibres of the present invention.Can reduce the intermediate value desorption pressures and the water retention value of cross filament by refined fiber before crosslinked.In addition, cross-linking reaction can be carried out to improve the efficient of crosslinking agent in the presence of one or more crosslinking accelerators of the present invention. Refining

Refining can being undertaken by any methods known in the art (comprising machine finish).Paper pulp is refining to be related to the fiber acting, carries out in aqueous slurry usually, but does not get rid of other modes.For example, thus can reduce average fiber length and make with extra care them by cutting off fiber.Perhaps, also can be by fiber being rubbed each other and on irregular surface, rubbing refined fiber.Cause that like this outer fiber surface area is owing to the delineation and the wearing and tearing on surface increase.In addition, the merit of input fiber causes fiber inwall and skin lamination during making with extra care.The result is the fibre wall attenuation, makes the fiber can be than more water of unpurified fiber absorbs and swelling to a greater degree.Never the dry refined fiber of crossing is also than similarly the unpurified never dry fiber of crossing is more soft.In addition, when compacting was in blocks, intensity that refined fiber produces in sheet after drying and deflection were bigger than what produce in the dry not refined fiber sheet.

At J.d ' A.Clark, The pulping technique of paper and processing (Pulp Technology and Treatment for Paper), the 2nd edition, the 8th chapter, pp.160～183, the 12 chapters, pp.277～305, the 13 chapters, pp.306～355, the 14 chapters, pp.356～407, Miller Freeman Pub. has described the method for refined fiber cellulose fiber among the San Francisco (1985), include but not limited to making beating and fibrillation.A kind of method for optimizing of refined fiber cellulose fiber is fibrillation.Available for example disk refiner or derive from Valley Mill Corporation ofLee, the Valley beater of MA comes the refined fiber cellulose fiber.Make with extra care and carry out at normal temperatures and pressures usually.For example, can flow through the Valley beater refined fiber cellulose fiber that reaches 15 minutes up to obtaining required beating degree by the aqueous slurry that makes cellulose fibre.

Usually, before refined fiber, fiber soaked or wetting.By an embodiment preferred, bleached cellulose fibres before refining.

Cellulose fibre roughly is refined to the beating degree of about 300～about 700ml CSF, preferably is refined to the beating degree of about 500～about 700ml CSF.By an embodiment preferred, cellulose fibre is refined to the beating degree of about 650～about 700ml CSF.The beating degree of the cellulose fibre of this paper discussion is measured by TAPPI T-227 method. Crosslinked

By covalent cross-linking in the fiber harden refining or unpurified cellulose fibre.Preferably, cellulose fibre with the reaction of crosslinking agent and crosslinking accelerator before, soaked or wetting.Ideally, in certain embodiments, described cellulose fibre is the never dry cellulose fibre of crossing.

Fiber is by they and crosslinking agent of the present invention and optional crosslinking accelerator (for example following those) reaction and crosslinked.Preferably, fiber is crosslinked under the situation of high distortion.Usually, this reactions steps is being carried out under the unrestricted condition basically, i.e. each fiber freely-movable and not with adjacent fibration and be not under any bigger tension force or pressure.Can be by cured fiber in the presence of crosslinking agent and optional crosslinking accelerator, fiber and crosslinking agent and the crosslinking accelerator chosen wantonly are reacted.

Usually, by the following method that fiber is crosslinked: as (i) they to be mixed with crosslinking agent of the present invention and optional crosslinking accelerator and (ii) be enough to cause cured fiber under the condition that intrafiber crosslink joins.To cause that generally effective dose crosslinking agent and optional crosslinking accelerator that intrafiber crosslink connection key forms mix with cellulose fibre.Preferably, the effective dose crosslinking accelerator is mixed with cellulose fibre, to increase the quantity and the generating rate of the intrafiber crosslink connection key that forms by fiber and crosslinking agent reaction.Usually, make the about 0.5～about 40mol% that calculates based on cellulose glucoside molal quantity, crosslinking agent and crosslinking accelerator and the mixed with fibers of preferred about 1～about 30mol%.When crosslinking agent is the dicarboxylic acids crosslinking agent, generally be crosslinking agent and the described mixed with fibers that makes the about 5～about 21mol% that calculates based on cellulose glucoside molal quantity.Usually, make crosslinking accelerator and the described mixed with fibers of the about 1.8～about 9mol% that calculates based on cellulose glucoside molal quantity.The mixture that contains fiber and crosslinking agent preferably contains the crosslinking agent of the 5～about 10wt% that has an appointment, with the fiber dry weight basis.

After crosslinking agent and mixed with fibers, preferably by for example evacuating fiber or cracked and evacuate fiber with fiber separation and individuation.By defibre, intrafiber crosslink connection is maximized and crosslinked being minimized between fiber.Preferably, the formation by covalent bond in the fiber makes fiber crosslinked.

The cellulose fibre that provides with the form of wet lap, dried lap or other compressing tablet can by machinery cracked they become loose form separate.With regard to dried lap, advantageously wetting fiber before machinery is cracked is for example wetting to 40% humidity (60% solid content is based on the gross weight of fiber and water), so that plasticized fibre minimizes fibre damage with making.

If in the aqueous solution, crosslinking agent is applied to fiber, before curing, want dried fibres.Preferred dried fibres solidifies to produce the intrafiber crosslink connection with whole water of removing in the fiber again.Drying can be undertaken by any methods known in the art.Usually, carry out drying by under about 50～about 225 ℃ temperature, adding thermal fiber.Preferably, under about 105～about 175 ℃ temperature, carry out drying.Usually fiber drying is arrived constant weight.No matter how fiber carries out dry temperature in the dry run, the temperature of fiber generally is no more than 100 ℃ (boiling points of water), evaporates from fiber up to whole water.As T.Lindstrom, Paper structure and performance (Paper Structure and Properties), international fiber and technology series 8 (International Fiber andTechnology Series 8), the 5th chapter, pp104～105, Marcel Dekker Inc., that is discussed among the NewYork (1986) is such, the irreversible reduction of swelling ability when the drying of cellulose fibre causes fiber wetting more usually.This phenomenon often is called keratinization.Be not bound by any theory, it is believed that the microfiber in the fibre wall combines in dry run, so reduced the size of fibre wall mesopore.This fiber that causes hardening (comparing) with the fiber before dry.Follow-up curing schedule promotes the formation of covalent bond in the fiber, dry fiber deflection and the physical dimension of its locking.

Curing is normally carried out under being enough to cause the temperature that covalent bond forms in the fiber.Solidify roughly under about 105～about 225 ℃ temperature and carry out.Preferably, cellulose fibre solidifies under about 150～about 190 ℃ temperature.More preferably, they solidify under about 160～about 175 ℃ temperature.Curing can be carried out 15,30,45 or 60 minutes or more of a specified duration.

By an embodiment preferred, make fiber crosslinked by the following method: (i) aqueous solution of crosslinking agent with the crosslinking accelerator of choosing wantonly to be contacted with the aqueous mixture of cellulose fiber, (ii) remove the water in the aqueous mixture, (iii) fibre machinery is separated into single basically form, (iv) dried fibres and (v) make the reaction of fiber and crosslinking agent and cause crosslinked in the fiber.Usually, step (ii) relates to remove most of water from aqueous mixture.Preferably, from aqueous mixture, remove abundant water and obtain to have the mixture of about 40～about 80wt% solids (based on the gross weight of 100% fiber and water).By a preferred embodiment, step (ii) relates to removes the mixture that anhydrates and obtain to have about 60wt% solids (based on the gross weight of 100% fiber and water) from aqueous mixture.Dewater, separation and drying steps cause the fiber high distortion that becomes.The state of distortion usually by cross-linking reaction at least in part but by halves, fixing enduringly.

For example, can be fiber is crosslinked by the method for describing in the U.S. Patent No. 5,190,563 (it is for referencial use to incorporate it into this paper), with the crosslinking agent in crosslinking agent of the present invention and the crosslinking accelerator replacement U.S. Patent No. 5,190,563.In U.S. Patent No. 5,190, in 563, cellulose fibre with contain C ₂～C ₉Polycarboxylic acid crosslinked dose solution contact.Then, fibre machinery is separated into single basically form, drying and with crosslinking agent reaction, keep single basically form simultaneously so that form intrafiber crosslink connection key.The cellulose fibre of individuation is contacted with the crosslinking agent that is enough to cause fiber to form the amount of intrafiber crosslink connection key.Preferably, the crosslinking agent of the about 0.5mol%～about 6.0mol% that calculates based on cellulose glucoside molal quantity is contacted with fiber.

When crosslinking agent contains the amino that participates in reaction or amido, preferably before cross-linking reaction or simultaneously, crosslinking agent is activated.Term used herein " activation " is meant the modified crosslinking agent so that the nitrogen-atoms of amino or amido is more active state, promptly is easier to reaction.Can be by any method activation crosslinking agent known in the art.For example, can make the crosslinking agent and the nitrite reaction that contain amine or amino come activating amine or amino nitrogen-atoms.

Can in the presence of reductant (antioxidant), make fiber crosslinked in order to avoid fiber yellowing during cross-linking reaction.Appropriate reductant includes but not limited to, hypophosphite, for example inferior sodium phosphate; Sodium hydrogensulfite; Sodium phosphite; And any combination of any above-mentioned substance.Preferred reductant is an inferior sodium phosphate.

Can be in the cross-linking reaction process or afterwards bleached fiber to improve their outward appearance.For example, can react and bleached fiber by making they and bleaching agent.Can utilize any bleaching agent known in the art.Suitable bleaching agent includes but not limited to hydrogen peroxide.

For example, bleaching agent can be included in the aqueous solution that contains crosslinking agent that is applied to fiber.Preferably, the described aqueous solution contains the bleaching agent of capacity, so that by adding the bleaching agent that mixture that the aqueous solution obtains in the fiber comprises about 2.5wt%～about 5wt%, based on the dry weight basis of fiber. The saturated dicarboxylic acid crosslinking agent

Term " saturated dicarboxylic acid " expression does not contain the dicarboxylic acids of any carbon-to-carbon double bond or three key.Saturated dicarboxylic acid can comprise the aliphatic chain of linear or branching, and promptly they are acyclics.Preferred saturated dicarboxylic acid includes but not limited to C ₂～C ₈Saturated dicarboxylic acid.Term " C ₂～C ₈Saturated dicarboxylic acid " be meant that the total number of carbon atoms wherein (comprise in the carboxyl those) is 2～8 dicarboxylic acids.C ₂～C ₈The limiting examples of saturated dicarboxylic acid has: oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid and suberic acid.Can mention C especially ₂～C ₆Saturated dicarboxylic acid and C ₂～C ₄Saturated dicarboxylic acid.

By an embodiment preferred, C ₃More senior saturated dicarboxylic acid such as C ₃～C ₈Saturated dicarboxylic acid and crosslinking accelerator for example the oxalic acid applied in any combination in cellulose fibre.

Another kind of saturated dicarboxylic acid is the saturated hydroxy dicarboxylic acids.Term " saturated hydroxy dicarboxylic acids " expression comprises the saturated dicarboxylic acid of at least one hydroxyl substituent.Suitable saturated hydroxy dicarboxylic acids includes but not limited to C ₂～C ₈Hydroxyl saturated dicarboxylic acid (that is, contain 2～8 carbon atoms those).What is particularly worth mentioning is that C ₂～C ₈The polyhydroxy saturated dicarboxylic acid.C ₂～C ₈The limiting examples of hydroxyl saturated dicarboxylic acid has: tartaric acid, malic acid, glucosaccharic acid and glactaric acid. Aromatic dicarboxylate's crosslinking agent

The aromatic compounds of term " aromatic dicarboxylate " expression HOOC-R-COOH, wherein R is that replace or unsubstituted phenyl.Term used herein " replacement " includes but not limited at least one in the following substituting group: hydroxyl, C ₁～C ₄Alkoxyl, C ₁～C ₄Alkyl, amino, halogen atom and nitro.

Preferred aromatic dicarboxylate has following formula: Wherein, R ¹, R ², R ³And R ⁴Be hydrogen, hydroxyl, C independently ₁～C ₄Alkoxyl, C ₁～C ₄Alkyl, amino, halogen atom or nitro.Preferred aromatic dicarboxylate is a phthalic acid. Cycloalkyl dicarboxylic acids crosslinking agent

Term " cycloalkyl dicarboxylic acids " is illustrated in the not cycloalkyl dicarboxylic acids of carbon-carbon double key of the α of carboxyl or β position.By an embodiment, the cycloalkyl dicarboxylic acids has following formula: Wherein,

R ⁶, R ⁷, R ¹⁰And R ¹¹Be hydrogen independently, hydroxyl, halogen atom, C ₁～C ₄Alkoxyl, C ₁～C ₄Alkyl, amino, or nitro; And

R ⁸And R ⁹Be hydrogen independently, halogen atom, C ₁～C ₄Alkoxyl or C ₁～C ₄Alkyl.

Preferred cycloalkyl dicarboxylic acids is 1,2,5, the 6-tetrahydrophthalic acid. Difunctionality monocarboxylic acid crosslinking agent

" difunctionality monocarboxylic acid " represents a kind of organic acid, it have (a) only carboxyl and (b) be not carboxyl but can with a functional group of carboxyl, carboxylic acid, amino or the hydroxyl reaction of polymer.Preferably, the difunctionality monocarboxylic acid only comprises two functional groups, i.e. a carboxyl and second functional group.

Suitable difunctionality monocarboxylic acid includes but not limited to, the acid derivative of the salt of amino acid, halogenated acetic acids, monobasic hydroxy-acid and monobasic hydroxy-acid (for example, the acid esters of monobasic hydroxy-acid).

Preferred halogenated acetic acids salt is sodium chloroacetate.Be not bound by any theory, it is believed that when dry and when solidifying the aqueous mixture of sodium chloroacetate and cellulose fibre, the chloride carbon atom by cellulose hydroxyl and sodium chloroacetate molecule reacts and forms ether.This etherification reaction discharges the salt acid molecule, and it is neutralized by the sodium salt of newly-generated cellulose base acid immediately.Under higher temperature, this acid can be used for nearest hydroxyl in the esterify cellobiose, follows release water.After ether and ester form, remaining sodium chloride as accessory substance.

Suitable monobasic hydroxy-acid and acid derivative thereof include but not limited to, the p-methyl benzenesulfonic acid ester of the methanesulfonates of glycollic acid, glycollic acid and glycollic acid. Amine carboxylic acid crosslinking agent

Suitable amine carboxylic acid includes but not limited to primary amine, secondary amine, tertiary amine and arylamine.Preferred primary amine includes but not limited to amino acid.What is particularly worth mentioning is that amino acid with following formula:

H ₂N-CH ₂-R ¹²-C (O) OH wherein, R ¹²Be singly-bound, C ₁～C ₁₂Alkyl is perhaps by carboxyl, hydroxyl, C ₁～C ₄Alkoxyl, C ₁～C ₄The C of the one or more replacements in alkyl, amino and the nitro ₁～C ₁₂Alkyl.

Preferred amino acids includes but not limited to have those of following formula:

Wherein, R ⁵Be linear or the C of branching ₁～C ₈Alkyl.By an embodiment preferred, R ⁵Be C ₂～C ₄Alkyl.Suitable amino acid whose limiting examples comprises aspartic acid and glutamic acid.

Other suitable amine carboxylic acid crosslinking agent includes but not limited to ethylene nitrilo-tetraacethyl (EDTA). Crosslinking accelerator

Crosslinking accelerator of the present invention increases the efficient of crosslinking agent.Preferred crosslinking accelerator is an oxalic acid.Be not bound by any theory, it is believed that oxalic acid (pKa=1.23) can be used as the acid catalyst of the esterification of crosslinking agent.Perhaps, oxalic acid can form mixed acid anhydride with crosslinking agent, and it promotes the esterification of cellulose fibre subsequently. Crosslinked invertibity

With the crosslinked fiber of short crosslinking agent of the present invention can be separated crosslinked and and then crosslinked, described short crosslinking agent promptly is to contain 4 or still less those of carbon atom (for example 3 or still less carbon atom), for example oxalic acid and sodium chloroacetate.The crosslinked of this fiber is reversible usually basically, that is, can be separated crosslinked at least about the crosslinked fiber of 50wt%.By an embodiment, at least about 60,70,80,90 or the crosslinked fiber of 95wt% can be separated crosslinked.

Can be enough to that they are separated the crosslinked time and separate crosslinked fiber crosslinked by crosslinked fiber being immersed in reach in the water.Usually, crosslinked fiber was soaked about 0.5～about 4 hours.By an embodiment preferred, fiber was soaked about 2 hours.Also can by make among the embodiment of crosslinked fiber experience as the application, the capillary absorption-desorption cycle of (literary composition sees before) descriptions such as Burgeni etc. (literary composition sees before) and Chatterjee separates crosslinked fiber crosslinked.

Can be by making them crosslinked again with solidifying described fiber drying or drying.United States Patent(USP) Nos. 5,137,537; The fiber of disclosed covalent cross-linking is not observed this phenomenon in 5,183,707 and 5,190,563.

Be not bound by any theory, it is believed that along with cross filament absorbs water and swelling, cross-bond since cellulosic polymer chain move and open the water that holds absorption and be tauted.When corsslinking molecular length very in short-term, come to this (be positioned between the hydroxyl on the plain polymer chain of adjacent fiber two carbon atoms are arranged) as the fiber of handling with oxalic acid and sodium chloroacetate, the stress of fiber swelling is enough to promote hydrolysis and the fracture in two covalent bonds of cross filament.On the contrary, as United States Patent(USP) Nos. 5,137,537; The crosslinked fiber of disclosed citric acid has the molecule (be positioned between the hydroxyl on the plain chain of adjacent fiber four or five carbon atoms are arranged) of much longer cross-over connection cellulosic polymer chain in 5,183,707 and 5,190,563.Therefore, along with fiber absorbs water and swelling, the understrressing on long corsslinking molecular is to promote a fracture in the crosslinked covalent bond.

Because it is crosslinked that fiber of the present invention can be separated, can transport or store with their dryings with sheet form rather than with form loose or big bag.This has just reduced transportation and storage cost.In the time of can or needing in the destination for example by separately and solidify they and described fiber is crosslinked again.In case fiber just can for example be incorporated into absorbing structure with them by crosslinked again.

Term used herein " reversible cross filament " and crosslinked fiber or the cross-linked cellulosic of " reversible cross-linked cellulose fibres " expression, wherein, in water, be dipped to many after 4 hours, at least about 50,60,70,80,90 or the crosslinked fiber of 95wt% separate crosslinked, and wherein by dried fibres under 105 ℃ or higher temperature can make at least 50,60,70,80,90 or 95wt% to separate cross filament crosslinked again.

Reversible crosslink fiber of the present invention is specially adapted to contain the absorbent core of superabsorbent polymer (SAP) particulate.Crosslinked fiber separation SAP particulate, and provide passage for fluid flows to dry section from the humidity district of absorbent core around the SAP particulate.In addition, the reversible crosslink fiber helps at short notice a large amount of urine (or other fluid) of (for example, once gushing out) absorption.In case urine or other fluid enter absorbent core, cross filament just begins to separate crosslinked.By an embodiment, be exposed to urine or other fluid after 0.5～4.0 hour, the major part of wet fiber is separated crosslinked.Separate crosslinked fiber and hold and keep urine or other fluid to a greater degree than permanent crosslinked fiber.As a result, absorbent core has the capacity of initially gushing out than the absorbent core improvement that contains conventional loose fiber, and has the wetting characteristics again than the absorbent core improvement that contains permanent cross filament. Absorbing structure

Cellulose fibre of the present invention can be incorporated into any disposable or non-once absorbing structure that is intended to absorb and keep body exudates, and they are placed or are clamped in and press close to the wearer's body place.Such absorbing structure is applied in the disposable and non-once absorbent article usually.The example of disposable absorbent article includes but not limited to, baby diaper, adult-incontinence articles, close-fitting sport pants, sanitary napkin and other women sanitary articles.Those that wherein can include but not limited to describe in the following patent: international publication number WO 98/47456 in conjunction with the absorbing structure example of cellulose fibre of the present invention, WO 99/63906, and WO 99/63922, WO 99/63923, WO 99/63925, and WO 00/20095, and WO 00/38607, WO 00/41882, WO 00/71790 and WO 00/74620, and U.S. Patent No. 5,695,486, it is for referencial use all to incorporate them into this paper. Acquisition layer and Distribution Layer

Cellulose fibre of the present invention can be incorporated into acquisition layer, Distribution Layer or collection-Distribution Layer.Layer like this is applied in the contained absorbing structure of disposable absorbent article usually.Collection and/or Distribution Layer can and be incorporated into absorbing structure by any methods known in the art preparation.By an embodiment, described absorbing structure comprises a top layer, and it comprises that acquisition layer of the present invention and/or Distribution Layer and store bottom (being also referred to as absorbent core).Collection and Distribution Layer can be one deck or two-layer independent layer, that is, and and the top acquisition layer and the Distribution Layer of below.The Distribution Layer of below is extracted fluid out and fluid is dispensed into the storage layer from acquisition layer rapidly.

Acquisition layer of the present invention generally comprises the cellulose fibre of the present invention of about 90～about 100wt%, is 100% in the gross weight of Distribution Layer.The density of acquisition layer is roughly at about 0.04～about 0.07g/cm ³In the scope. Absorbent core

Cellulose fibre of the present invention can be incorporated into absorbent core (be also referred to as and store layer).Absorbent core can comprise the material of any absorption liquid known in the art.Suitable material includes but not limited to, the fibrofelt or the web of fiber that are made of defiber, loose, fluffing and/or hydrophilic cellulose fibre or fiber of the present invention; Superabsorbent polymer (SAP) particulate, particle, sheet or fiber (particulate of gathering); And any combination of above-mentioned substance.Usually, the SAP particulate can absorb a lot of liquid doubly of their weight, and enlarges markedly the absorptive capacity of absorbent core but do not increase the volume of described layer basically.

Term " superabsorbent polymer particulate " or " SAP particulate " intention comprise the superabsorbent polymer of any granular form, comprise the particulate of irregular particle, spherical particle (bead), powder, sheet, artificial fibre and other elongation.SAP represents crosslinked and makes its water-fast basically normally water miscible polymer, can absorb at least ten times of its own wt, preferred fifteenfold at least saline usually.The SAP particulate can be arbitrary dimension or shape.A lot of examples of super strength water absorbent and preparation method thereof are found in, for example, and United States Patent(USP) Nos. 4,102,340; 4,467,012; 4,950,264; 5,147,343; 5,328,935; 5,338,766; 5,372,766; 5,849,816; 5,859,077 and Re.32,649.Suitable SAP particulate example includes but not limited to, starch graft copolymer, for example starch-acrylate graft copolymers of hydrolysis; Cross-linked carboxymethyl cellulose and derivative thereof; And the hydrophilic polyacrylic ester of modification, saponification acrylate-ethylenic copolymer for example, the cross linked polyacrylate of neutralization, and crosslinked polyacrylate.

Preferably, the SAP particulate forms aquogel when absorption fluids.More preferably, the SAP particulate has high gel volume or high-gel strength (modulus of shearing by aquogel is measured).What such SAP particulate generally contained lower content can be by contacting the polymer (so-called extractable) that is extracted with synthetic urine.An example of this class SAP particulate is the starch graft polyacrylate aquogel, can be used as IM1000 ^From Hoechst-Celanese of Portsmouth, VA obtains.Other example that contains the aquogel of SAP particulate includes but not limited to that the Sanyo KaseiKogyo Kabushiki of Japan is with trade mark SANWET ^TMThose that sell; The Sumitomo KagakuKabushiki Haishi of Japan is with trade mark SUMIKA GEL ^TMThose that sell; With Stockhausen ofGaryville, LA is with trade mark FAVOR ^TMThose that sell; And BASF of Aberdeen, MS is with trade mark ASAP ^TMThose that sell.

By an embodiment preferred, described absorbent core comprises: (a) SAP particulate, and (b) loose fiber, matrix fiber, fiber of the present invention or its any combination.Above-mentioned fiber provides structural intergrity and provides passage for fluid flows through absorbent core.

By another embodiment, described absorbent core comprises the SAP particulate of about 30～about 70wt% and the cellulose fibre of the present invention of about 70～about 30wt%, is 100% in the gross weight of absorbent core.Usually, the weight density of absorbent core is about 0.15～about 0.25g/cm ³

By another embodiment, described absorbent core comprises the fiber of SAP particulate and reversible crosslink of the present invention.By an embodiment preferred, the fiber of described reversible crosslink is crosslinked with oxalic acid, sodium chloroacetate or its mixture.Usually, described absorbent core comprises the fiber of the reversible crosslink of the present invention of the SAP particulate of about 30～about 70wt% and about 70～about 30wt%, is 100% in the gross weight of absorbent core.By another embodiment preferred, described acquisition layer and/or Distribution Layer and absorbent core comprise with the crosslinked fiber of oxalic acid.

Absorbing structure of the present invention can be incorporated into disposable and the non-once absorbent article, for example, and paper handkerchief, adult incontinent pads and women sanitary articles.Described absorbent article can comprise, be positioned at the permeability for liquids top layer of acquisition layer and/or Distribution Layer top, its effect is to allow fluid to flow to acquisition layer and/or Distribution Layer, and liquid impermeability tergite, its effect is to hold fluid and prevent it from flowing through absorbent article and flow on the clothes of wearer of absorbent article.

By an embodiment, absorbing structure of the present invention is incorporated into the disposable infant diaper, and the latter generally includes: Attacking Midfielder's zone, low back zone and the crotch between them.The structure of described diaper generally comprises: permeability for liquids top layer, liquid impermeability tergite, absorbing structure, elastic component and fixing clasp.Representational disposable diaper DESIGN SKETCH is found in for example United States Patent(USP) Nos. 4,935,022 and 5,149,335.

By another embodiment, absorbing structure of the present invention is incorporated into the feminien hygiene pad, for example, U.S. Patent No. 5,961, that describes in 505 is the sort of.

Following embodiment for example understands the present invention rather than limits it.Unless otherwise indicated, all umber and percentages all provide with weight.The whole crosslinking agents, crosslinking accelerator and other chemical reagent that are used for these embodiment all can derive from Aldrich Chemical Company ofMilwaukee, WI. The mensuration of capillary and desorption pressures and saturated capacity

Capillary absorption and desorption pressure all is by " the capillary absorption equilibrium in the fibrous matter ", A.A.Burgeni and C.Kapur, and the textile research magazine, the method for describing in 37:356～366 (1967) is measured.This method is described in detail as follows:

Become diameter to be about the disk of 55～60mm 0.75g individuation fiber process.Sample is placed the thick sintering Pyrex glass of 150ml funnel, and (Corning No.36060 can derive from VWR of Suwanee, sintered sheets place GA).Be enough to provide the suitable weight of 0.22psi pressure, diameter and sample diameter to be placed on the sample with one.Funnel bottom is connected on the diameter crossover sub decrescence, and with an about R-3603 Tygon of 2 feet long ^One of pipe is connected on the crossover sub, and the other end is connected to the fluid reservoir that is placed on the electronic scale that can be weighed to 0.01g.Described pipe is connected the bottom of described reservoir side.Fill 0.9% saline solution in the fluid reservoir.The height of saline solution is about more than 1 inch in the pipe junction in the fluid reservoir.In pipe, inject salt solution, inject salt solution in the funnel below the sintering place yet, make the sintering place, but top, sintering place does not have salt solution by the salt water-soaked.Salt water column from reservoir to sintering is continuous, and post is interior without any air.

It is as follows to absorb circulation.Above the saline water level in reservoir certain altitude for example 20,30 or 80cm begin, make absorption of sample salt solution to balance or stable state.Stable state is defined as, and in one fen clock time, the variation of the salt solution weight that shows on the electronic scale of reservoir below is not more than 0.04g.When reaching stable state, sample is reduced the water level of salt solution in the more close reservoir of 5cm and remain there up to reaching balance.Sample is reduced 5cm again and repeats aforesaid operations.In sample is in reservoir during the water level equal height balance of salt solution, the inverse operation by aforesaid operations promptly moves up by sample is increased progressively with 5cm, makes sample experience desorption cycle.

Salt solution weight when identical with the water level of salt solution in the reservoir in the sample is the saturated capacity of sample.Determine in (absorptions) downwards circulation the analog value (intermediate value desorption pressures) of 50% o'clock sample in the saturated capacity height above the saline water level (with the cm report) (intermediate value absorption pressure) and (desorb) curve that makes progress in reservoir by interpolation method.Salt solution gram number with every gram sample in table has been reported the saturated capacity value.

Embodiment 1～8

Embodiment 1～8 in the table 1 is prepared as follows.

With beating degree is that the not refined fiber cellulose fiber of 740ml CSF (can be used as Foley Fluff ^TMFiber derives from Buckeye Technologies Inc.of Memphis, TN) slurrying in water, and be refined to suitable beating degree with the Valley beater at normal temperatures and pressures.Fiber is centrifugal, hand, air-dry again to 60% solids.By spraying fiber with having the aqueous citric acid solution that is enough to fibre sheet is diluted to the concentration of 40% solid content, and with citric acid (dried fiber base) cross filament of debita spissitudo.Then, shake up to 60% solid content fiber is air-dry, be dried to constant weight, and under temperature shown in the table 1, heat 30 minutes again.

Measure water retention value, saturated capacity, capillary absorption pressure and the capillary desorption pressures of the cellulose fibre that solidifies.The water retention value of the cellulose fibre that solidifies is by TAPPI Useful Methods, the time-and-motion study of describing among the UM 256.Capillary absorption and desorption pressure is measured by aforementioned operation.

Show the result in the table 1.

The comparative example 9

The not refined fiber cellulose fiber that is 740ml CSF 100 ℃ of following dry beating degrees (can be used as Foley Fluff ^TMFiber derives from Buckeye Technologies Inc.of Memphis, TN).Press water retention value, saturated capacity, capillary absorption pressure and capillary desorption pressures that the method for describing among the embodiment 1 is measured the cellulose fibre that solidifies.

Show the result in the following table 1.

The comparative example 10

Spraying beating degree with the water of capacity is that the not refined fiber cellulose fiber of 740ml CSF (can be used as Foley Fluff ^TMFiber derives from Buckeye Technologies Inc.) and produce 40% solid content.Fiber is air-dry to 60% solid content, and machinery is loose, and is dried to constant weight under 150 ℃.Then, under uniform temp, fiber was heated 30 minutes again.Press water retention value, saturated capacity, capillary absorption pressure and capillary desorption pressures that the method for describing among the embodiment 1 is measured the cellulose fibre that solidifies.

Show the result in the table 1.

The comparative example 11

With beating degree is that the not refined fiber cellulose fiber of 740ml CSF (can be used as Foley Fluff ^TMFiber derives from Buckeye Technologies Inc.) slurrying in water, be refined to the beating degree of about 500ml CSF with the Valley beater.Fiber is centrifugal, and hand is air-dryly shaken up to 60% solid content, and is dried to constant weight under 150 ℃.Then, under 150 ℃, fiber was heated 30 minutes again.Press water retention value, saturated capacity, capillary absorption pressure and capillary desorption pressures that the method for describing among the embodiment 1 is measured the cellulose fibre that solidifies.

Show the result in the table 1.

The comparative example 12

With beating degree is that the not refined fiber cellulose fiber of 740ml CSF (can be used as Foley Fluff ^TMFiber derives from Buckeye Technologies Inc.) slurrying in water, be refined to the beating degree of about 500ml CSF with the Valley beater.Fiber is centrifugal, hand, air-dry to 60% solids.When handling fiber, spray cellulose fibre to 40% solid content with the aqueous sulfuric acid of pH3, so that the identical pH that the pH that regulates fiber-aqueous mixtures observes in the embodiment 1 with aqueous citric acid solution.Shake up to 60% solid content fiber is air-dry, and under 150 ℃, be dried to constant weight.Then, under 150 ℃, fiber was heated 30 minutes again.Press water retention value, saturated capacity, capillary absorption pressure and capillary desorption pressures that the method for describing among the embodiment 1 is measured the cellulose fibre that solidifies.

Show the result in the table 1.

The comparative example 13

By spraying fiber and make fibre sheet become 40% solid content, be that the not refined fiber cellulose fiber of 740ml CSF (can be used as Foley Fluff with the crosslinked beating degree of 5% citric acid (dried fiber base) with having enough dilution aqueous citric acid solution ^TMFiber derives from BuckeyeTechnologies Inc.).Fibre sheet is air-dry to 60% solid content, and machinery is loose, is dried to constant weight under 150 ℃.Then, under 150 ℃, fibre sheet was heated 30 minutes again.Press water retention value, saturated capacity, capillary absorption pressure and capillary desorption pressures that the method for describing among the embodiment 1 is measured the cellulose fibre that solidifies.

Show the result in the table 1.

The comparative example 14

Repeat the operation of description among the comparative example 13, different is that it is crosslinked to replace 5% citric acid to carry out with 10% citric acid.

Show the result in the table 1.

Table 1

Embodiment	Beating degree (ml CSF)	Crosslinked (% citric acid) (dried fiber base)	Solidification temperature (℃)	?WRV(％)	Saturated capacity (g/g)	50% o'clock absorption pressure (cm) in saturated capacity	50% o'clock desorption pressures (cm) in saturated capacity
								Embodiment 1	?500	?5	?150	?44.8	?8.2	?3.9	?13.4
Embodiment 2	?500	?10	?150	?38.1	?8.7	?4.4	?13.5
								Embodiment 3	?300	?5	?150	?42.7	?8.2	?5.3	?14.7
Embodiment 4	?300	?10	?150	?41.5	?8.6	?5.1	?14.9
								Embodiment 5	?500	?5	?175	?36.7	?8.5	?4.4	?14.0
Embodiment 6	?500	?10	?175	?29.5	?8.3	?3.1	?11.9
								Embodiment 7	?300	?5	?175	?33.4	?7.9	?4.2	?15.0
Embodiment 8	?300	?10	?175	?29.9	?7.5	?3.0	?13.3
								The comparative example 9	?740	?-	?100	?83.0	?9.3	?12.3	?30.5
The comparative example 10	?740	?-	?150	?73.6	?11.0	?12.0	?27.4
								The comparative example 11	?500	?-	?150	?92.1	?8.2	?8.1	?20.7
The comparative example 12	?500	?-	?150	?78.6	?8.3	?5.3	?16.3
								The comparative example 13	?740	?5	?150	?43.3	?12.3	?-	?17.9
The comparative example 14	?740	?10	?150	?38.4	?12.1	?6.7	?18.4

Shown in the result in the table 1, refining and crosslinked fiber shows than similarly making with extra care and crosslinked lower WRVs and the desorption pressures of fiber.

Embodiment 15 Refining

Preparation contains the never dry Foley Fluff that crosses of 2.75～3.25wt% ^TMThe water slurry of fiber (can derive from Buckeye Technologies Inc.).At normal temperatures and pressures, " this water slurry of pump pumping passes through refiner to use BauerModel No.444,24.The Bauer refiner plate is No.A24313.

Refiner is operated under the flow rate of slurry of 178 amperes electric current and 255 gallon per minute.These conditions produce the load of 30～60 horsepower-hours/over dry short ton fiber.The fiber of producing has the beating degree of 680ml CSF. Demineralization

Refining paper pulp is pumped in the auxiliary kerve with 2.75～3.25% denseness.In agitating pulp, add sulfuric acid until the nominal pH that reaches 2.0.Stir after at least 10 minutes, make aqueous slurry flow through sieve of the auxiliary end and reach minimum 3 hours with dehydration.Then, with the denseness of the softening water diluted slurry to 2.0% of sodium with regulate pH to 4.5～5.0. Compressing tablet

The paper pulp compressing tablet is to derive from Sandy Hill Corporation of Hudson Falls, carrying out in the paper machine of NY.Deckle (cardboard is wide) maximum is 36 inches.2% paper pulp pumping is entered the plain boiled water cellar for storing things by paper stock case and proportional valve and with the flow velocity of control.Temperature to 130 in the directly logical steam raising cellar for storing things～150 is with the denseness of interior slurry to 1.0～1.25% in plain boiled water dilution cellar for storing things.

Then, slurry feed is gone into the head box of paper machine, and transfer on the Fordrinier mobile silk partly of paper machine.Carry out natural drainage and vacuum aided draining, up to the profiled sheeting of discharging about 32% denseness from couch press.Form behind the plate but before couch press, with the fabric width of two jet water courses wet plate unhairing limit to 24 inch.Then, make fiberboard, further remove water here and make denseization of plate by two wet press with about 32% denseness.After coming out from second wet press, fiberboard enters first dryer section with about 48% denseness.In first dryer section, described pulp board passes through 13 about 300～325 rotary steam generator.Described pulp board subsequently in second dryer section by eight rotary steam generators, and moisture content is 4～8% when coming out from drying machine.Fiberboard coiled fabric width is about 23 inches volume.The basis weight of this coiled material is about 0.126 pounds per square foot, and density is about 0.60g/cm ³ Rip cutting

Above-mentioned paper pulp is rolled up again around to new core, and the volume of rip cutting Cheng Gengxiao, 10 inches of every volumes are wide. Chemistry spreads

10 inches wide paper pulp volume is unclamped, and lentamente by a puddling press.The aqueous solution of the roll gap of puddling press is exuberant citric acid and inferior sodium phosphate.Inferior sodium phosphate has alleviated paper pulp blackening at high temperature.The citric acid in exuberant roll gap and the weight concentration of inferior sodium phosphate are about 14% and 7% respectively.By the puddling press, described pulp board has absorbed the aqueous solution of capacity and has reached about 40% moisture content. Pulpboard is pulverized and is loose

After the puddling press, fiberboard is torn into less fragment by shredder, prebreaker and picker.Then, with the paper pulp of pulverizing be blown into Sunds Defibrator Model 3784RO Fluffer (can derive from Sunds Defibrator, AB of Sundsvall, inlet Sweden), roll gap is set in 5.5mm.This defibrator with fiber dregs of rice combs loose composition from fiber.High velocity air with about 380 hot-airs scans out RO Fluffer with the fiber dregs of rice of evacuating. Drying and curing

To quicken from the thermal current that RO Fluffer carries the fiber of evacuation to come out to evaporate the water all or almost all in the fiber herein with air blast by a flash dryer.The dry fiber dregs of rice are fallen on the mechanical input tape, form the bed of low-density high level expansion on conveyer belt.Then, fiber is imported Proctor﹠amp; Schwartz K16476 tunnel dryer (can derive from Proctor﹠amp; Schwartz, Inc.of Horsham, PA).By a series of thermal cycle air flows, the fibre bed of evacuation is heated cooling then earlier by three chambers in the drier.In chamber 1, bed tempertaure reaches 325～330 °F.In chamber 2, bed tempertaure is elevated to 385～390 °F.In chamber 3, bed tempertaure is reduced to 355～360 °F.Total time in tunnel dryer is about 11.5 minutes. Packing

The cross filament that comes out from the exit of tunnel dryer leaves conveyer belt and enters 3445 type baling presses and (can derive from American Baler Company of Bellevue, OH), at this this material is pressed into heavily about 70～80 pounds bag.

Embodiment 16

Prepared the sample in the table 2 as follows.

With beating degree is that the not refined fiber cellulose fiber of 740ml CSF (can be used as Foley Fluff ^TMFiber derives from Buckeye Technologies Inc.of Memphis, TN) slurrying in water, and at normal temperatures and pressures, and with Bauer Model No.444,24 " the pump pumping is refined to suitable beating degree by refiner.Randomly, wash fiber (pickling) to remove mineral matter with dilute sulfuric acid.With refining fiber compressing tablet and drying.

Get a fibre sheet and immerse the tray that fills crosslinking agent and oxalic acid solution.Then this fibre sheet is overturn, and immerse the solution of second part of crosslinking agent and oxalic acid.Total solution contains 10% crosslinking agent (dried fiber base) and 5% oxalic acid (dried fiber base).These solution have is enough to make this piece fibre sheet to be the dilution factor of 40% solid content.Place the Polythene Bag of sealing to preserve 1 hour this fibre sheet.Shake up to 60% solid content fiber is air-dry, be dried to constant weight, again 175 ℃ of heating 30 minutes down.

Measure water retention value, saturated capacity, capillary absorption pressure and the capillary desorption pressures of the cellulose fibre that solidifies.The water retention value of the cellulose fibre that solidifies is by TAPPI UsefulMethods, the time-and-motion study of describing among the UM 256.Capillary absorption and desorption pressure is measured by preceding method.

Show the result in the table 2.

Table 2

Sample	Crosslinking agent	Beating degree (ml CSF)	Pickling	??WRV ??(％)	Saturated capacity (g/g)	50% o'clock absorption pressure (cm) of saturated capacity	50% o'clock desorption pressures (cm) of saturated capacity	Carboxyl (meq/kgm)
									??a	Succinic acid	??740	????No	??31.5	????13.9	?6.8	??14.7	????343.1
??b	Succinic acid	??570	????No	??36.3	????13.5	?7.2	??17.3	????294.1
									??c	Succinic acid	??570	????Yes	??36.0	????13.7	?7.2	??16.1	????303.9
??d	Adipic acid	??740	????No	??36.0	????13.5	?7.4	??16.4	????228.6
									??e	Adipic acid	??570	????No	??39.1	????12.6	?7.0	??16.4	????190.6
??f	Adipic acid	??570	????Yes	??40.0	????13.1	?7.8	??18.3	????179.3
									??g	Pimelic acid	??740	????No	??35.4	????14.7	?6.4	??17.5	????231.4
??h	Pimelic acid	??570	????No	??39.4	????13.9	?6.9	??17.7	????209.0
									??i	Pimelic acid	??570	????Yes	??37.9	????12.2	?7.3	??17.3	????200.0
??j	Malonic acid	??740	????No	??32.8	????16.1	?7.2	??18.9	????75.6
									??k	Malonic acid	??570	????No	??36.5	????11.6	?6.1	??16.8	????78.2
??l	Malonic acid	??570	????Yes	??37.7	????12.7	?7.1	??15.8	????85.5

Embodiment 17

Prepare the sample in the table 3 as follows.

With beating degree is that the not refined fiber cellulose fiber of 740ml CSF (can be used as Foley Fluff ^TMFiber derives from Buckeye Technologies Inc.of Memphis, TN) slurrying in water, and at normal temperatures and pressures, and with Bauer Model No.444,24 " the pump pumping is refined to suitable beating degree by refiner.With refining fiber compressing tablet and dry.Be wet lap as fruit fiber, then that they are centrifugal.

Get in the tray that fibre sheet immerses the solution that fills crosslinking agent, inferior sodium phosphate and optional oxalic acid.The fibre sheet that overturns then, and immerse again in the solution of second part of crosslinking agent, inferior sodium phosphate and optional oxalic acid.Total solution contains 10% crosslinking agent (dried fiber base), 5% inferior sodium phosphate (dried fiber base) and optional 1% oxalic acid (dried fiber base).These solution have is enough to make this fibre sheet to be the dilution factor of 40% solid content.Place the Polythene Bag of sealing to preserve 1 hour this piece fibre sheet.Shake up to 60% solid content fiber is air-dry, be dried to constant weight, and under 175 ℃, heat 30 minutes again.

Measure water retention value, saturated capacity, capillary absorption pressure and the capillary desorption pressures of the cellulose fibre that solidifies.The water retention value of the cellulose fibre that solidifies is by TAPPI UsefulMethods, the time-and-motion study of describing among the UM 256.Capillary absorption and desorption pressure is measured by the aforementioned operation method.

Show the result in the table 3.

Table 3

Sample	Crosslinking agent	The concentration of oxalic acid (%w/w)	Beating degree (ml CSF)	??WRV ??(％)	Saturated capacity (g/g)	50% o'clock absorption pressure (cm) of saturated capacity	50% o'clock desorption pressures (cm) of saturated capacity	Carboxyl (meq/kgm)
									????a	Oxalic acid	??-	????740	??48.3	????12.0	????6.2	????18.9	???292.5
????b	Maleic acid	??-	????740	??33.8	????15.3	????4.7	????16.4	???529.5
									????c	Succinic acid	??-	????740	??38.2	????14.0	????5.3	????16.7	???414.8
????d	Adipic acid	??-	????740	??45.7	????13.4	????5.7	????17.2	???343.9
									????e	Succinic acid	??1	????740	??37.8	????14.5	????4.6	????14.9	???432.2
????f	Adipic acid	??1	????740	??45.3	????13.0	????6.1	????17.8	???356.3
									????g	Citric acid	??-	????740	??33.1	????15.6	????4.4	????15.2	???442.0
????h	Oxalic acid	??-	????680	??47.3	????10.5	????6.5	????18.4	???287.7
									????i	Maleic acid	??-	????680	??34.2	????14.4	????4.2	????15.0	???530.2
????j	Succinic acid	??-	????680	??38.0	????12.8	????5.8	????16.6	???436.8
									????k	Adipic acid	??-	????680	??49.6	????11.8	????5.4	????15.6	???351.3
????l	Succinic acid	??1	????680	??37.0	????14.0	????4.4	????14.3	???424.6
									????m	Adipic acid	??1	????680	??45.8	????12.3	????6.3	????17.7	???358.5
????n	Citric acid	??-	????680	??31.3	????15.8	????3.7	????13.5	???450.3
									????o	Oxalic acid	??-	570 (wet laps)	??59.9	????3.2	????5.2	????12.7	???432.0
????p	Maleic acid	??-	570 (wet laps)	??41.6	????5.1	????3.8	????7.7	???474.0
									????q	Succinic acid	??-	570 (wet laps)	??34.8	????8.8	????3.2	????8.3	???466.1
????r	Adipic acid	??-	570 (wet laps)	??50.1	????9.0	????3.4	????8.7	???487.5
									????s	Succinic acid	??1	570 (wet laps)	??36.1	????8.8	????3.3	????8.7	???415.4
????t	Adipic acid	??1	570 (wet laps)	??44.2	????8.6	????3.3	????8.9	???422.1
									????u	Citric acid	??-	570 (wet laps)	??35.0	????9.7	????3.3	????9.2	???468.6
????v	Oxalic acid	??-	????570	??49.6	????11.7	????5.3	????15.8	???405.8
									????w	Maleic acid	??-	????570	??41.5	????12.4	????5.9	????16.7	???450.7
????x	Succinic acid	??-	????570	??37.2	????13.4	????4.8	????15.1	???510.1
									????y	Adipic acid	??-	????570	??44.9	????11.3	????5.3	????16.0	???328.0
????z	Succinic acid	??1	????570	??40.7	????12.0	????5.4	????16.2	???455.5
									????aa	Adipic acid	??1	????570	??48.6	????11.4	????5.9	????16.7	???371.0
????bb	Citric acid	??-	????570	??39.9	????13.7	????3.8	????12.9	???481.1

Embodiment 18

Prepare the sample in the table 4 as follows.

Crosslinking agent and crosslinking accelerator by amount shown in the general are dissolved in the 22.5g distilled water crosslinking agent that marks in the preparation table 4 and the storing solution of crosslinking accelerator.

Handle sample as follows with an amount of solution: with the storing solution that contains crosslinking agent and crosslinking accelerator in right amount handle 15g (butt) compressing tablet, beating degree is that the not refined fiber cellulose fiber of 740ml CSF (can be used as Foley Fluff ^TMFiber derives from Buckeye TechnologiesInc.of Memphis, TN) sample.This processing is reduced to 40% with the fiber solid content of mixture.At room temperature fiber is placed in the container of sealing to reach 60 minutes, air-dry then to 60% solid content.The mechanical separation fiber makes its individuation, shakes up in the experiment loosening apparatus, and be dried to constant weight in 175 ℃ forced air drying box.Under uniform temp, fiber was solidified 30 minutes.

Prepare as follows in the same old way: the not refined cellulose fiberboard that water is dried with, beating degree is 740ml CSF (can be used as Foley Fluff ^TMFiber derives from BuckeyeTechnologies Inc.of Memphis, TN) is diluted to 40% solid content.Regulate the pH to 3 of mixture with sulfuric acid.The pH that is coated with the storing solution that imposes on fiber in said procedure is generally 3.At room temperature mixture is placed subsequently in the container of sealing to reach 60 minutes, air-dry then to 60% solid content.The mechanical separation fiber makes its individuation, shakes up in the experiment loosening apparatus, and be dried to constant weight in 175 ℃ forced air drying box.Under uniform temp, fiber was heated 30 minutes again.

Obtain from Pampers ^Disposable diaper (can derive from Proctor and Gamble ofCincinnati, the fiber of collection-Distribution Layer OH) and as second in the same old way.

Measure water retention value, saturated capacity, capillary absorption pressure and the capillary desorption pressures of above-mentioned fiber.The water retention value of cellulose fibre is by TAPPI Useful Methods, the time-and-motion study of describing among the UM 256.Capillary absorption and desorption pressure and saturated capacity are measured by the aforementioned operation method.

Show the result in the table 4.

Table 4

Sample	Crosslinking agent	The amount of crosslinking agent (g) in the storing solution	Crosslinking accelerator	The amount of crosslinking accelerator (g) in the storing solution	??WRV ??(％)	Saturated capacity (g/g)	50% o'clock absorption pressure (cm) of saturated capacity	50% o'clock desorption pressures (cm) of saturated capacity
									????a	Do not have (contrast)	??-	Do not have	???-	??59.4	??13.6	??10.7	??24.6
????b	????Pampers (contrast)	??-	????-	???-	??44.9	??6.7	??4.4	??18.2
									????c	Sodium chloroacetate	??0.75	Do not have	???-	??49.8	??12.7	??9.5	??22.2
????d	Sodium chloroacetate	??1.5	Do not have	???-	??44.6	??11.1	??8.2	??18.5
									????e	Oxalic acid	??0.15	Do not have	???-	??47.2	??12.9	??9.1	??23.6
????f	Oxalic acid	??0.75	Do not have	???-	??42.9	??13.6	??8.6	??21.5
									????g	Oxalic acid	??1.5	Do not have	???-	??38.5	??15.3	??7.6	??17.8
????h	Succinic acid	??1.5	Do not have	???-	??39.8	??14.2	??7.5	??20.4
									????i	Succinic acid	??1.5	Oxalic acid	???0.15	??33.8	??14.3	??7.7	??16.6
????j	Succinic acid	??1.5	Oxalic acid	???0.75	??31.5	??13.9	??6.8	??14.7
									????k	Adipic acid	??1.5	Do not have	???-	??50.5	??14.1	??8.0	??22.3
????l	Adipic acid	??1.5	Oxalic acid	???0.15	??38.9	??13.7	??8.6	??19.8
									????m	Adipic acid	??1.5	Oxalic acid	???0.75	??36.0	??13.5	??7.4	??16.4
????n	Malonic acid	??1.5	Do not have	???-	??39.5	??13.5	??7.8	??22.8
									????o	Malonic acid	??1.5	Oxalic acid	???0.75	??32.8	??16.1	??7.2	??18.9
????p	Glutaric acid	??1.5	Do not have	???-	??37.1	??15.2	??7.5	??23.4
									????q	Glutaric acid	??1.5	Oxalic acid	???0.75	??33.0	??15.9	??7.3	??21.9
????r	Pimelic acid	??1.5	Do not have	???-	??42.7	??14.8	??7.4	??23.1
									????s	Pimelic acid	??1.5	Oxalic acid	???0.75	??35.4	??14.7	??6.4	??17.5
????t	Suberic acid	??1.5	Do not have	???-	??56.0	??13.7	??8.3	??25.7
									????u	Suberic acid	??1.5	Oxalic acid	???0.75	??41.0	??14.2	??7.2	??21.4
????v	Phthalic acid	??1.5	Do not have	???-	??55.4	??13.9	??8.4	??26.3
									????w	Phthalic acid	??1.5	Oxalic acid	???0.75	??42.5	??13.0	??9.0	??24.6
????x	Tetrahydrophthalic acid	??1.5	Do not have	???-	??53.4	??12.6	??8.4	??22.5
									????y	Tetrahydrophthalic acid	??1.5	Oxalic acid	???0.75	??39.4	??13.3	??7.4	??19.9
????z	Fumaric acid	??1.5	Do not have	???-	??44.5	??13.9	??9.1	??24.1
									????aa	Fumaric acid	??1.5	Oxalic acid	???0.75	??41.5	??12.7	??8.4	??19.2
????bb	Glycollic acid	??1.5	Do not have	???-	??47.8	??13.3	??8.7	??22.0
									????cc	Glycollic acid	??1.5	Oxalic acid	???0.75	??39.6	??14.0	??7.3	??17.4
????dd	Tartaric acid	??1.5	Do not have	???-	??34.3	??13.7	??7.3	??18.5
									????ee	Tartaric acid	??1.5	Oxalic acid	???0.75	??32.2	??13.1	??7.3	??18.3
????ff	Malic acid	??1.5	Do not have	???-	??31.6	??14.5	??6.9	??19.0
									????gg	Malic acid	??1.5	Oxalic acid	???0.75	??30.1	??14.0	??6.6	??18.7
????hh	Glucosaccharic acid	??1.5	Do not have	???-	??49.6	??13.4	??9.4	??22.8
									????ii	Glucosaccharic acid	??1.5	Oxalic acid	???0.75	??41.1	??11.4	??8.2	??19.4
????jj	Glactaric acid	??1.5	Do not have	???-	??55.9	??12.4	??9.9	??19.0
									????kk	Glactaric acid	??1.5	Oxalic acid	???0.75	??40.3	??11.9	??8.4	??17.1
????ll	Aspartic acid	??1.5	Do not have	???-	??55.2	??13.9	??9.5	??26.6
									????mm	Aspartic acid	??1.5	Oxalic acid	???0.75	??37.5	??14.6	??6.5	??16.5
????nn	Glutamic acid	??1.5	Do not have	???-	??52.8	??13.8	??7.8	??25.1
									????oo	Glutamic acid	??1.5	Oxalic acid	???0.75	??37.4	??14.2	??7.0	??17.3
????pp	????EDTA	??1.5	Do not have	???-	??50.7	??12.1	??8.6	??21.9
									????qq	????EDTA	??1.5	Oxalic acid	???0.75	??39.7	??12.1	??8.0	??18.4

Embodiment 19

By the method for describing among the embodiment 18, prepare the sample of cross filament with the 1.5g sodium chloroacetate.Replace second sample of sodium chloroacetate preparation with 1.5g oxalic acid.

For relatively,, prepare the sample of cross filament with the storing solution that contains the 10wt% citric acid by the method for describing among the embodiment 18.

Make these sample experience capillary absorption-desorption cycle for the first time by aforementioned program.Then, by the identical operations method, make these sample experience capillary absorption-desorption cycle for the second time.The observed absorption and desorption pressure of twice circulation is shown in the following table 5.

With uncrosslinked Foley Fluff ^TMFiber repeats this test.

Table 5

	Crosslinking agent
					Do not have	Oxalic acid	Sodium chloroacetate	Citric acid
	Circulation for the first time
Saturated capacity (g/g)						????13.6	????15.3	????12.2	????18.5
	At 50% o'clock absorption pressure (cm) of saturated capacity 50% o'clock desorption pressures (cm) in saturated capacity	????10.7	????7.6	????10.5	????7.0
????24.6						????17.8	????18.2	????13.5
		Circulation for the second time
Saturated capacity (g/g) is at 50% o'clock absorption pressure (cm) of saturated capacity, 50% o'clock desorption pressures (cm) in saturated capacity	????11.8						????13.1	????9.6	????16.5
		????＞30	????＞30	????＞30	????15.3
	????25.8					????29.3	????24.7	????18.4

Embodiment 20

The sample of describing among the preparation embodiment 19 also makes it experience capillary absorption-desorption cycle twice.With these samples dried overnight in 105 ℃ forced air drying box.Perhaps, sample is dried to constant weight under 105 ℃, and under 175 ℃, heats 30 minutes (curing) again.The saturated capacity of working sample and absorption and desorption pressure.

Show the result in the table 6.

Table 6

	Crosslinking agent
					Do not have	Oxalic acid	Sodium chloroacetate	Citric acid
	Dry down at 105 ℃
Saturated capacity (g/g) is at 50% o'clock absorption pressure (cm) of saturated capacity, 50% o'clock desorption pressures (cm) in saturated capacity						????12.8	????12.3	????10.3	????17.1
	????12.2	????8.6	????11.5	????7.1
					????24.7	????18.1	????19.8	????14.3
	Solidify down at 175 ℃
Saturated capacity (g/g) is at 50% o'clock absorption pressure (cm) of saturated capacity, 50% o'clock desorption pressures (cm) in saturated capacity						????11.3	????11.2	????9.5	????14.4
	????13.0	????6.8	????12.6	????7.2
					????24.6	????18.1	????19.6	????13.7

Embodiment 21 Chemistry spreads

By mixing the aqueous solution that 151 pounds of 10wt% oxalic acid solutions, 15 pounds of 50wt% ortho phosphorous acid sodium solutions and 1 pound of water prepare oxalic acid and inferior sodium phosphate.

Foley Fluff with 10 inches wide ^TMFiber roll (can derive from BuckeyeTechnologies Inc.) is unclamped, and lentamente by a puddling press.The aqueous solution of the roll gap of puddling press is exuberant oxalic acid and inferior sodium phosphate.Inferior sodium phosphate has alleviated the blackening at high temperature of the fiber dregs of rice.By the puddling press, fiberboard absorbs the aqueous solution of capacity and reaches about 47% moisture content, is 100% in dried total weight of fiber.The plate of handling also contains the inferior sodium phosphate of oxalic acid and the 5wt% of the 10wt% that has an appointment, is 100% in dried total weight of fiber. Fiberboard is pulverized and is shaken up

After the puddling press, fiberboard is torn into less fragment by shredder, prebreaker and picker.Then, with the paper pulp of pulverizing be blown into Sunds Defibrator Model 3784RO Fluffer (can derive from Sunds Defibrator, AB of Sundsvall, inlet Sweden), roll gap is set in 5.5mm.This defibrator with fiber dregs of rice combs loose composition from fiber.High velocity air with about 380 hot-airs scans out RO Fluffer with the fiber dregs of rice of shaking up. Drying and curing

The thermal current that will come out from the fiber that RO Fluffer conveying is shaken up with air blast quickens to evaporate the whole water in the fiber herein by a flash dryer.The dry fiber dregs of rice are fallen on the mechanical input tape, form the bed of low-density high level expansion on conveyer belt.Then, fiber is imported Proctor﹠amp; Schwartz K16476 tunnel dryer (can derive from Proctor﹠amp; Schwartz, Inc.of Horsham, PA).By a series of thermal cycle air flows, the fibre bed of shaking up is heated by three chambers in the drier.In chamber 1, bed tempertaure reaches 330～340 °F.In chamber 2, bed tempertaure is elevated to 375～385 °F.In chamber 3, bed tempertaure is reduced to 355～360 °F.Behind three thermals treatment zone, fibre bed does not heat in addition by a last heat-insulating room.Total time in tunnel dryer is about 11.5 minutes. Packing

The cross filament that comes out from the exit of tunnel dryer leaves conveyer belt and enters 3445 type baling presses and (can derive from American Baler Company of Bellevue, OH), at this this material is pressed into heavily about 85～100 pounds big bag.

All documents of this paper citation are all incorporated into for referencial use.As for the contradiction that may exist between this specification and the list of references, be as the criterion with language disclosed herein.

Claims (138)

1. the cellulose fibre that has the 15cm that in capillary absorption-desorption cycle, measures or littler intermediate value desorption pressures.

2. the cellulose fibre of claim 1, wherein, this cellulose fibre has 14cm or littler intermediate value desorption pressures.

3. the cellulose fibre of claim 1, wherein, this cellulose fibre has 13cm or littler intermediate value desorption pressures.

4. the cellulose fibre of claim 1, wherein, this cellulose fibre has 12cm or littler intermediate value desorption pressures.

5. each cellulose fibre in the claim 1～4, wherein, this cellulose fibre has 45% or littler water retention value.

6. each cellulose fibre in the claim 1～4, wherein, this cellulose fibre has 38% or littler water retention value.

7. each cellulose fibre in the claim 1～4, wherein, this cellulose fibre has 30% or littler water retention value.

8. each cellulose fibre in the claim 1～7, wherein, this cellulose fibre is crosslinked.

9. contain collection and Distribution Layer that right requires each cellulose fibre in 1～8.

10. contain the acquisition layer that right requires each cellulose fibre in 1～8.

11. contain the Distribution Layer that right requires each cellulose fibre in 1～8.

12. an absorbing structure, it comprises:

(a) top layer comprises the cellulose fibre with the 15cm that measures or littler intermediate value desorption pressures in capillary absorption-desorption cycle; And

(b) comprise the bottom of SAP particulate, this second layer is communicated with the ground floor fluid.

13. the absorbing structure of claim 12, wherein, described cellulose fibre has 14cm or littler intermediate value desorption pressures.

14. the absorbing structure of claim 13, wherein, described cellulose fibre has 13cm or littler intermediate value desorption pressures.

15. the absorbing structure of claim 14, wherein, described cellulose fibre has 12cm or littler intermediate value desorption pressures.

16. each absorbing structure in the claim 12～15, wherein, described cellulose fibre has 45% or littler water retention value.

17. each absorbing structure in the claim 12～15, wherein, described cellulose fibre has 38% or littler water retention value.

18. each absorbing structure in the claim 12～15, wherein, described cellulose fibre has 30% or littler water retention value.

19. an absorbing structure, it comprises in the claim 1～8 each cellulose fibre.

20. an absorbing structure, it comprises the collection and the Distribution Layer of claim 9.

21. an absorbing structure, it comprises the acquisition layer of claim 10.

22. an absorbing structure, it comprises the Distribution Layer of claim 11.

23. a method for preparing cellulose fibre, it comprises the steps:

(a) cellulose fibre is refined to the beating degree of about 300～about 700ml CSF; With

(b) crosslinked described refining cellulose fibre.

24. the method for claim 23, wherein, the refining cellulose fibre of quilt is wet lap in the step (a).

25. the method for claim 23, wherein, step (a) comprises the beating degree that cellulose fibre is refined to about 500～about 700ml CSF.

26. the method for claim 25, wherein, step (a) comprises the beating degree that cellulose fibre is refined to about 650～about 700ml CSF.

27. the method for claim 23, wherein, step (b) comprising:

(i) refining cellulose fibre is mixed with crosslinking agent; With

The (ii) cellulose fibre in the curing mixture.

28. the method for claim 23, wherein, step (b) comprising:

(i) refining cellulose fibre is mixed with crosslinking agent;

Cellulose fibre in the mixture is evacuated; And

The (iii) cellulose fibre in the curing mixture.

29. the method for claim 28, wherein, step (b) (iii) comprises dry described cellulose fibre and solidifies this dry cellulose fibre.

30. the method for claim 28, wherein, curing is to carry out under about 150 ℃～about 175 ℃ temperature.

31. cellulose fibre by each method preparation in the claim 23～29.

32. a method for preparing absorbing structure, it comprises:

(a) prepare cellulose fibre by each method in the claim 23～29; And

(b) above-mentioned cellulose fibre is incorporated into absorbing structure.

33. cellulose fibre, crosslinked with at least a crosslinking agent that is selected from saturated dicarboxylic acid, aromatic dicarboxylate, cycloalkyl dicarboxylic acids, difunctionality monocarboxylic acid and the amine carboxylic acid, and have the 25cm that in capillary absorption-desorption cycle, measures or littler intermediate value desorption pressures.

34. the cellulose fibre of claim 33, wherein, described saturated dicarboxylic acid has 2～8 carbon atoms.

35. the cellulose fibre of claim 34, wherein, described saturated dicarboxylic acid has 2～6 carbon atoms.

36. the cellulose fibre of claim 35, wherein, described saturated dicarboxylic acid has 2～4 carbon atoms.

37. the cellulose fibre of claim 34, wherein, described saturated dicarboxylic acid is selected from: any combination of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and above-mentioned any carboxylic acid.

38. the cellulose fibre of claim 33, wherein, described saturated dicarboxylic acid is the saturated hydroxy carboxylic acid.

39. the cellulose fibre of claim 38, wherein, described saturated hydroxy carboxylic acid has 2～8 carbon atoms.

40. the cellulose fibre of claim 39, wherein, described hydroxyl saturated dicarboxylic acid is selected from: any combination of glycolic acid, tartaric acid, malic acid, glucosaccharic acid, glactaric acid and above-mentioned any carboxylic acid.

41. the cellulose fibre of claim 33, wherein, described aromatic dicarboxylate has following formula: Wherein, R ¹, R ², R ³And R ⁴Be hydrogen, hydroxyl, C independently ₁～C ₄Alkoxyl, C ₁～C ₄Alkyl, amino, halogen atom or nitro.

42. the cellulose fibre of claim 41, wherein, described aromatic dicarboxylate is a phthalic acid.

43. the cellulose fibre of claim 33, wherein, described cycloalkyl dicarboxylic acids has following formula: Wherein,

R ⁶, R ⁷, R ¹⁰And R ¹¹Be hydrogen independently, hydroxyl, halogen atom, C ₁～C ₄Alkoxyl, C ₁～C ₄Alkyl, amino, or nitro; With

R ⁸And R ⁹Be hydrogen independently, halogen atom, C ₁～C ₄Alkoxyl or C ₁～C ₄Alkyl.

44. the cellulose fibre of claim 43, wherein, described cycloalkyl dicarboxylic acids is 1,2,5, the 6-tetrahydrophthalic acid.

45. the cellulose fibre of claim 33, wherein, described difunctionality monocarboxylic acid is selected from: the acid derivative of the salt of halogenated acetic acids, monobasic hydroxy-acid, monobasic hydroxy-acid, and any combination of any above-mentioned substance.

46. the cellulose fibre of claim 45, wherein, the salt of described halogenated acetic acids is sodium chloroacetate.

47. the cellulose fibre of claim 33, wherein, described amine carboxylic acid is an amino acid.

48. the cellulose fibre of claim 47, wherein, described amino acid has following formula:

H ₂N-CH ₂-R ¹²-C (O) OH wherein, R ¹²Be singly-bound, C ₁～C ₁₂Alkyl is perhaps by carboxyl, hydroxyl, C ₁～C ₄Alkoxyl, C ₁～C ₄The C of the one or more replacements in alkyl, amino and the nitro ₁～C ₁₂Alkyl.

49. the cellulose fibre of claim 47, wherein, described amino acid has following formula:

Wherein, R ⁵Be linear or the C of branching ₁～C ₈Alkyl.

50. the cellulose fibre of claim 49, wherein, R ⁵Be C ₂～C ₄Alkyl.

51. the cellulose fibre of claim 47, wherein, described amino acid is selected from aspartic acid, glutamic acid, and any combination of above-mentioned any material.

52. the cellulose fibre of claim 33, wherein, described amine carboxylic acid is an ethylene nitrilo-tetraacethyl.

53. each cellulose fibre in the claim 33～52, wherein, this cellulose fibre is crosslinked in order to the crosslinking agent of about 5～about 21mol% of cellulose glucoside molal quantity meter.

54. each cellulose fibre in the claim 33～53, wherein, this cellulose fibre is crosslinked in the presence of crosslinking accelerator.

55. the cellulose fibre of claim 54, wherein, described crosslinking accelerator is different with crosslinking agent.

56. the cellulose fibre of claim 54 or 55, wherein, described crosslinking accelerator is an oxalic acid.

57. each cellulose fibre in the claim 54～56, wherein, this cellulose fibre is crosslinked in the presence of the crosslinking accelerator in about 1.8～about 9mol% of cellulose glucoside molal quantity.

58. each cellulose fibre in the claim 54～57, wherein, this cellulose fibre is crosslinked in order to crosslinking agent and the crosslinking accelerator of about 0.5～about 40mol% of cellulose glucoside molal quantity meter.

59. each cellulose fibre in the claim 54～58, wherein, this cellulose fibre is crosslinked in order to crosslinking agent and the crosslinking accelerator of about 1～about 30mol% of cellulose glucoside molal quantity meter.

60. each cellulose fibre in the claim 33～59, wherein, this cellulose fibre is derived from wood pulp.

61. each cellulose fibre in the claim 33～60, wherein, this cellulose fibre is made with extra care before crosslinked.

62. the cellulose fibre of claim 61, wherein, this cellulose fibre is refined to the beating degree of about 300～about 700ml CSF before crosslinked.

63. the cellulose fibre of claim 62, wherein, this cellulose fibre is refined to the beating degree of about 500～about 700ml CSF before crosslinked.

64. the cellulose fibre of claim 63, wherein, this cellulose fibre is refined to the beating degree of about 650～about 700ml CSF before crosslinked.

65. each cellulose fibre in the claim 33～64, wherein, this cellulose fibre solidifies under about 105 ℃～about 225 ℃ temperature.

66. the cellulose fibre of claim 65, wherein, this cellulose fibre solidifies under about 150 ℃～about 190 ℃ temperature.

67. the cellulose fibre of claim 66, wherein, this cellulose fibre solidifies under about 160 ℃～about 175 ℃ temperature.

68. each cellulose fibre in the claim 33～67, wherein, this cellulose fibre is to be cured in the presence of reductant.

69. the cellulose fibre of claim 68, wherein, described reductant is a hypophosphite.

70. the cellulose fibre of claim 69, wherein, described reductant is an inferior sodium phosphate.

71. each cellulose fibre in the claim 33～70, wherein, the water retention value of this cellulose fibre is 50% or littler.

72. the cellulose fibre of claim 71, wherein, the water retention value of this cellulose fibre is 45% or littler.

73. the cellulose fibre of claim 72, wherein, the water retention value of this cellulose fibre is 38% or littler.

74. the cellulose fibre of claim 73, wherein, the water retention value of this cellulose fibre is 30% or littler.

75. each cellulose fibre in the claim 33～74, wherein, the intermediate value desorption pressures of this cellulose fibre of measuring in capillary absorption-desorption cycle is 20cm or littler.

76. the cellulose fibre of claim 75, wherein, the intermediate value desorption pressures of this cellulose fibre of measuring in capillary absorption-desorption cycle is 18cm or littler.

77. the cellulose fibre of claim 76, wherein, the intermediate value desorption pressures of this cellulose fibre of measuring in capillary absorption-desorption cycle is 15cm or littler.

78. each cellulose fibre in the claim 33～77, wherein, described crosslinked be reversible substantially.

79. each cellulose fibre in the claim 33～78, wherein, described crosslinking agent is an oxalic acid, and crosslinked be reversible substantially.

80. by each cellulose fibre in the claim 33～79 is separated crosslinked prepare separate cross-linked cellulose fibres.

81. claim 80 separate cross-linked cellulose fibres, wherein, described crosslinking agent contains 4 or carbon atom still less.

82. claim 81 separate cross-linked cellulose fibres, wherein, described crosslinking agent is an oxalic acid.

83. claim 81 separate cross-linked cellulose fibres, wherein, described crosslinking agent is a sodium chloroacetate.

84. in the claim 80～83 each separate cross-linked cellulose fibres, wherein, separate cross-linking step and comprise cellulose fibre is immersed in the water.

85. claim 84 separate cross-linked cellulose fibres, wherein, separate cross-linking step and comprise cellulose fibre is immersed in the water about 0.5～about 4 hours.

86. sheet material of separating cross-linked cellulose fibres that comprises in the claim 80～85 each.

87. absorbing structure that comprises each fiber in the claim 33～79.

88. a method for preparing cross-linked cellulose fibres, it comprises with at least a saturated dicarboxylic acid, aromatic dicarboxylate, cycloalkyl dicarboxylic acids, difunctionality monocarboxylic acid or amine carboxylic acid carries out the intrafiber crosslink connection with cellulose fibre.

89. the method for claim 88, wherein, described saturated dicarboxylic acid has 2～8 carbon atoms.

90. the method for claim 89, wherein, described saturated dicarboxylic acid has 2～6 carbon atoms.

91. the method for claim 90, wherein, described saturated dicarboxylic acid has 2～4 carbon atoms.

92. the method for claim 89, wherein, described saturated dicarboxylic acid is selected from any combination of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and above-mentioned any carboxylic acid.

93. the method for claim 88, wherein, described saturated dicarboxylic acid is the saturated hydroxy carboxylic acid.

94. the method for claim 93, wherein, described saturated hydroxy carboxylic acid has 2～8 carbon atoms.

95. the method for claim 94, wherein, described C ₂～C ₈The hydroxyl saturated dicarboxylic acid is selected from any combination of glycolic acid, tartaric acid, malic acid, glucosaccharic acid, glactaric acid and above-mentioned any carboxylic acid.

96. the method for claim 88, wherein, described aromatic dicarboxylate has following formula: Wherein, R ¹, R ², R ³And R ⁴Be hydrogen, hydroxyl, C independently ₁～C ₄Alkoxyl, C ₁～C ₄Alkyl, amino, halogen atom or nitro.

97. the method for claim 96, wherein, described aromatic dicarboxylate is a phthalic acid.

98. the method for claim 88, wherein, described cycloalkyl dicarboxylic acids has following formula: Wherein,

R ⁶, R ⁷, R ¹⁰And R ¹¹Be hydrogen independently, hydroxyl, halogen atom, C ₁～C ₄Alkoxyl, C ₁～C ₄Alkyl, amino, or nitro; With

R ⁸And R ⁹Be hydrogen independently, halogen atom, C ₁～C ₄Alkoxyl or C ₁～C ₄Alkyl.

99. the method for claim 98, wherein, described cycloalkyl dicarboxylic acids is 1,2,5, the 6-tetrahydrophthalic acid.

100. the method for claim 88, wherein, described difunctionality monocarboxylic acid is selected from: the acid derivative of the salt of halogenated acetic acids, monobasic hydroxy-acid, monobasic hydroxy-acid, and any combination of any above-mentioned substance.

101. the method for claim 100, wherein, the salt of described halogenated acetic acids is sodium chloroacetate.

102. the method for claim 88, wherein, described amine carboxylic acid is an amino acid.

103. the method for claim 102, wherein, described amino acid has following formula:

H ₂N-CH ₂-R ¹²-C (O) OH wherein, R ¹²Be singly-bound, C ₁～C ₁₂Alkyl is perhaps by carboxyl, hydroxyl, C ₁～C ₄Alkoxyl, C ₁～C ₄The C of the one or more replacements in alkyl, amino and the nitro ₁～C ₁₂Alkyl.

104. the method for claim 102, wherein, described amino acid has following formula: Wherein, R ⁵Be linear or the C of branching ₁～C ₈Alkyl.

105. the method for claim 104, wherein, R ⁵Be C ₂～C ₄Alkyl.

106. the method for claim 102, wherein, described amino acid is selected from aspartic acid, glutamic acid, and any combination of above-mentioned any material.

107. the method for claim 88, wherein, described amine carboxylic acid is an ethylene nitrilo-tetraacethyl.

108. each method in the claim 88～107, wherein, the mole percent of the crosslinking agent that calculates based on cellulose glucoside molal quantity is about 5～about 21mol%.

109. each method in the claim 88～108, wherein, cross-linking step is to carry out in the presence of crosslinking accelerator.

110. the method for claim 109, wherein, described crosslinking agent is different from crosslinking accelerator.

111. the method for claim 109 or 110, wherein, described crosslinking accelerator is an oxalic acid.

112. each method in the claim 109～111, wherein, the mole percent of the crosslinking accelerator that calculates based on cellulose glucoside molal quantity is about 1.8～about 9mol%.

113. each method in the claim 109～112 wherein, is about 0.05～about 40 based on the crosslinking agent of cellulose glucoside molal quantity calculating and the mole percent of crosslinking accelerator.

114. each method in the claim 109～113 wherein, is about 1～about 30 based on the crosslinking agent of cellulose glucoside molal quantity calculating and the mole percent of crosslinking accelerator.

115. each method in the claim 88～114, wherein, cross-linking step comprises:

(i) cellulose fibre is mixed with crosslinking agent; And

The (ii) cellulose fibre in the curing mixture.

116. each method in the claim 88～115, wherein, cross-linking step comprises:

(i) cellulose fibre is mixed with crosslinking agent;

Cellulose fibre in the mixture is evacuated; And

The (iii) cellulose fibre in the curing mixture.

117. the method for claim 116, wherein, step (iii) comprises the dry cellulose fibre of dry described cellulose fiber peacekeeping curing.

118. each method in the claim 115～117, wherein, curing is to carry out under about 150 ℃～about 175 ℃ temperature.

119. each cellulose fibre in the claim 88～118, wherein, described fiber is crosslinked in the presence of reductant.

120. the cellulose fibre of claim 119, wherein, described reductant is a hypophosphite.

121. the cellulose fibre of claim 120, wherein, described reductant is an inferior sodium phosphate.

122. each method in the claim 88～121, wherein, described cellulose fibre is made with extra care before cross-linking step.

123. the method for claim 122, wherein, described cellulose fibre is refined to the beating degree of about 500～about 700ml CSF.

124. the method for claim 123, wherein, described cellulose fibre is refined to the beating degree of about 650～about 700ml CSF.

125. cellulose fibre by each method preparation in the claim 88～124.

126. one kind prepares the method for separating cross filament, it comprises the steps: with at least a saturated dicarboxylic acid, aromatic dicarboxylate, cycloalkyl dicarboxylic acids, difunctionality monocarboxylic acid or amine carboxylic acid cellulose fibre to be carried out the intrafiber crosslink connection; With separate this cross-linked cellulosic crosslinked.

127. the method for claim 126, wherein, described crosslinking agent contains 4 or carbon atom still less.

128. the method for claim 127, wherein, described crosslinking agent is an oxalic acid.

129. the method for claim 127, wherein, described crosslinking agent is a sodium chloroacetate.

130. each method in the claim 126～129 wherein, is separated cross-linking step and is comprised cross-linked cellulosic is immersed in the water.

131. the method for claim 130 wherein, is separated cross-linking step and is comprised cross-linked cellulosic is immersed in the water about 0.5～about 4 hours.

132. a method for preparing the sheet material of separating cross-linked cellulose fibres, it comprises the following steps: to separate cross-linked cellulose fibres and this is separated cross-linked cellulose fibres by each method preparation in the claim 126～131 to be processed into sheet material.

133. a method for preparing cross-linked cellulose fibres, it comprises the following steps:

(a) separate cross-linked cellulose fibres by each method preparation in the claim 126～131; And

(b) crosslinked above-mentioned cellulose fibre.

134. a method for preparing absorbing structure, it comprises:

(a) prepare cellulose fibre by each method in claim 88～124 and 133; And

(b) above-mentioned cellulose fibre is incorporated into absorbing structure.

135. an absorbent core, it comprises the cellulose fibre of superabsorbent polymer particulate and reversible crosslink.

136. the absorbent core of claim 135, wherein, the cellulose fibre of described reversible crosslink is crosslinked with oxalic acid, sodium chloroacetate or its mixture.

137. the absorbent core of claim 136, wherein, the cellulose fibre of described reversible crosslink is crosslinked with oxalic acid.

138. each absorbent core in the claim 135～137, wherein, this absorbent core comprises the fiber of the reversible crosslink of the high-absorbable particulate of about 30～about 70wt% and about 70～about 30wt%, is 100% in the gross weight of absorbent core.