CN1221629A

CN1221629A - Absorbent article comprising porous absorbent polymeric macrostrutures

Info

Publication number: CN1221629A
Application number: CN 98105853
Authority: CN
Inventors: D·C·罗; F·H·拉尔曼; C·J·堡格
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1990-04-02
Filing date: 1998-03-25
Publication date: 1999-07-07

Abstract

Absorbent polymeric macrostructures that are porous and comprise an interparticle crosslinked aggregate having a circumscribed dry volume greater than about 10.0 mm3. The interparticle crosslinked aggregate comprises a multiplicity of precursor particles of substantially water-insoluble, absorbent, hydrogel-forming, polymer material; and an interparticle crosslinking agent reacted with the polymer material of the precursor particles to form crosslink bonds between the precursor particles. Because of the particulate nature of the precursor particles, the macrostructure has pores between adjacent precursor particles. The pores are interconnected by intercommunicating channels such that the macrostructure is liquid permeable.

Description

Comprise porous, absorbability arranged, the absorbing products of polymeric gross structure thing

The present invention is that application number is 91102721.1, the applying date is on April 2nd, 1991, denomination of invention is divided an application for the application for a patent for invention of " make porous, the method for absorbability, polymeric gross structure thing is arranged ".

The present invention relates to absorbefacient polymerization and constitute thing, this works and liquid just expand during such as water or the contact of health ginseng fluid and absorb these liquid.More particularly, the present invention relates to polymer such as the gross structure of slabbing, thin film or strip.Such polymerization gross structure thing is porous, so that can be permeated by liquid.These porous, absorbefacient polymeric gross structure thing can independently use, also can be made into such as diaper, and the adult bed pad of urinary incontinence, sanitary towels etc. are assimilate similarly.The present invention also relates to make the method for this porous, absorbefacient, polymeric gross structure thing.

Granular, absorbefacient paradigmatic structure thing can absorb a large amount of liquid, as water and health transudate etc.And under moderate degree of pressure, can also retain such absorption liquid.Particularly useful when utilizing this absorbability of paradigmatic structure thing to manufacture assimilate as diaper and so on.For example, 3,699, No. 103 patents of the U.S. that propose by Harper etc. on June 13rd, 1972 and 3,670, No. 731 patents of the U.S. of announcing on June 20th, 1972 of proposing by Hamann etc.The application of in assimilate graininess, absorbefacient, paradigmatic structure thing (being also referred to as hydrogel, superabsorbers, or water sucting glue material) is all disclosed.

But, traditional graininess, absorbability, the paradigmatic structure thing has such shortcoming, and promptly it can not be fixed these granules between processing and/or operating period or freely move.In the course of processing, particulate moving may be caused the loss in the loading and unloading in the production process, especially when using this kind grain structure thing to become particulate admix heterogeneous.Yet more serious problem appears at when these granular materials between the phase of expansion or during the change after expanding.Such mobility makes because intergranular capillary tube or fluid transfer deficient in stability and to causing high resistance by the material flowing liquid.This phenomenon is commonly referred to a kind of form of " gel caking " exactly.

For overcome under the operating position with the particulate shortcoming that moves on the relevant performance, a kind of trial is in assimilate granular absorbefacient paradigmatic structure thing to be made multiwalled thin layer (lamellated absorber).Because the granule between each thin layer encapsulates, granule mobility total in absorbing component has reduced.But when contact liq, the granule of coating interior moves freely each other, and causes the destruction of the logical fluid passage of capillary between any particle that has earlier.

Another is for the immobilized particles shape, the reward examination scheme of absorbability paradigmatic structure thing be add a large amount of liquid polyols as binding agent granule is combined or becomes a substrate.An embodiment of this technology is disclosed in United States Patent (USP) 4,410 by Hamann in October 18 nineteen eighty-three, in 571.And this method is just in time before expanding and in expanding, limited particulate moving to a certain extent, make these granules in fact become disconnected from each other and be presented on, cause the destruction of the logical fluid passage of any original capillary between the granule once more on the excessive liquid of this paradigmatic structure thing.

The another kind trial that overcomes this problem is by making a kind of polymer solution extrusion molding of linearity.Make crosslinked polymer to form a kind of super-absorbert thin film then.The example of this technology is equaled to be disclosed on August 29th, 1989 in 4,861, No. 539 patents of the U.S. by inferior orchid.Though these super-absorbert thin film may absorb a large amount of liquid, limited the liquid transfer performance and be easy to produce the gel caking owing to they lack the internal capillaries passage.

Therefore, the present invention attempts by providing a kind of porous, absorbefacient, and polymeric gross structure thing solves above-mentioned problem.

An object of the present invention is to provide absorbefacient polymer gross structure thing (an absor-bent polymeric macrostructure), this works is porous.

Another object of the present invention is to provide the gross structure thing of absorbefacient polymer, also keeps intact and fluid transfer even if it is under the excessive liquid immersion.

Another purpose of the present invention provides absorbefacient polymeric gross structure thing, and its particle and hole also keep their mutual geometry and spatial relationships even be under the excess liq immersion.

A further object of the present invention provides absorbefacient polymerization gross structure thing, and its impregnability to liquid when expanding strengthens.

The present invention also has another purpose to provide the method for making such absorbability paradigmatic structure thing.

Another purpose that the present invention has again provides a kind of improved absorbent products that embodies absorbability polymerization gross structure thing of the present invention particularly, absorbent member, and absorbent commodity (for example diaper or sanitary towel).

The invention provides a kind of absorbefacient polymerization gross structure thing, this works is porous.This is porous, and is absorbefacient, polymerization gross structure thing comprise one between particle crosslinked agglomerate, this agglomerate is had an appointment greater than 10.0mm ³Limited dry volume.The cross-linked cohesion body of intergranular comprises a large amount of, and is water-fast in fact, absorbefacient, the formation hydrogel, the precursor particle of polymeric material (precursor particle, precursor granules); React between different precursor particles, to form the intergranular cross-linking agent of cross-bond with the polymeric material of precursor particle with a kind of.Because the granular nature of precursor particle, the gross structure thing has hole between adjacent precursor particle.These holes are interconnection by interconnective passage, but make that this gross structure thing is liquid body infiltration (transmission channel that capillary is promptly arranged).

Because formed intergranular cross-bond has formed intergranular cross-linked cohesion body between the precursor particle, makes the gross structure thing have globality on the good structure, thereby has improved the ratio of catching and distributing of liquid, has reduced gelatinous caking simultaneously.Have been found that when the gross structure thing contacts with liquid even under moderate limited pressure, the gross structure thing is generally isotropic expansion, this Liquid Absorption gone in the precursor particle, and with this Liquid Absorption in hole.Even isotropic expansion of gross structure thing makes precursor particle and hole thereof in the geometry and the spatial relationship that also keep after the expansion between them.Thereby this gross structure thing is " liquid stable " each other.Here, the precursor particle is cracking mutually not, has reduced the incidence rate of gel caking thus, and makes that capillary channel obtains keeping and enlarging after expanding, thereby the gross structure thing may be obtained and transmit the liquid load of coming one after the other, even if it is also passable to have excessive liquid.

The present invention also relates to by porous of the present invention, absorbefacient paradigmatic structure thing is formed, excellent absorption product, absorption component and absorbing articles.The gross structure thing is by catching liquid rapidly, effectively distributes and stores such liquid and strengthened the liquid handling performance of this product, so that obtain and liquid load that transmission is come one after the other, and makes gel caking and gel in this product move minimizing.

The present invention also relates to make this porous, absorbefacient, the method for polymerization gross structure thing.This gross structure thing is by a kind of intergranular cross-linked material is applied on the precursor particle, in fact make the precursor particle be combined into an agglomerate, and make the polymeric material reaction of intergranular cross-linked material and precursor particle so that form crosslinking chemical bond between each precursor particle.In a most preferred embodiment, this gross structure thing be by the precursor particle that will combine the granule press molding to produce a kind of desired shape, size, and/or the gross structure thing of density.The precursor particle constituent element of this gross structure also can be surface-crosslinked.

The conclusion that particularly points out description with claim and clear and definite the present invention is made qualification before, by the explanation of doing below in conjunction with accompanying drawing, can make better understanding to the present invention.Wherein:

Fig. 1 is one and amplifies nearly 40 times micro-photograph, represent porous of the present invention, absorbefacient polymer gross structure (observing from become 15 ° with level) perspective edge view.

Fig. 2 is the part at gross structure shown in Figure 1, has amplified 120 times the micro-photograph of top view approximately.

Fig. 3 is one and amplifies nearly 30 times micro-photograph, represent corner's (from horizontal plane angle at 45 observation) perspective view of gross structure shown in Figure 1.

Fig. 4 is a kind of porous that has adopted super absorption fiber in the gross structure thing, absorbability, the part top view of the example of the gross structure of polymer, amplified nearly 20 times micro-photograph.

Fig. 5 is the top view of the gross structure part of Fig. 4, has amplified nearly 50 times micro-photograph.

Fig. 6 is a part of top view of the gross structure of Fig. 4, has amplified nearly 75 times micro-photograph.

Fig. 7 is be embedded with polyester fiber in gross structure another kind of porous, the part of absorbefacient polymer gross structure example (from 45 with level) perspective, amplified nearly 100 times micro-photograph.

Fig. 8 is the perspective view of disposable diaper embodiment of the present invention, here, demonstrate the absorbent cores (example of absorption component of the present invention) of diaper pad and the part cover plate is cut off for clearer, it is porous that the absorption component in the diaper pad comprises the present invention, absorbefacient, polymer gross structure thing.

Fig. 9 is a diaper absorbent cores shown in Figure 8, along the sectional drawing of Fig. 8 section line 9-9 intercepting.

Figure 10 is the perspective view of disposable diaper example of the present invention,, in order more clearly to express another kind of absorbent cores embodiment, coping plate is cut off a part here.

Below the present invention is done detailed explanation.

Porous of the present invention, the gross structure thing of absorbable polymer is to absorb big quantity of fluid, for example water or/and body excretes liquid the formation thing of (for example urine or menstruation), and it can retain these liquid under moderate degree of pressure.Specifically, porous of the present invention, what absorbability, the gross structure thing of polymer will be whole, isotropicly promptly absorb liquid and expand.

As convention, gross structure thing one speech refers to a kind of product, and this product has the 10.0mm of being about at least when dry in fact ³Defined volume (being limited dry volume), be preferably and have 100mm at least ³, best have 500mm at least ³Typically, gross structure thing of the present invention will have much larger than 500mm ³Limited dry volume.In most preferred embodiment of the present invention, this gross structure thing has about 1000mm ³To about 100,000mm ³Limited dry volume.

And gross structure thing of the present invention can have different shape and size, and this gross structure thing typically can be made into lamellar, film like, and bulk, spherical, fibrous, the member of thread or other shape.This gross structure thing has thickness or the diameter that is about between the 0.25mm to 10.0mm usually.In order in absorbent products, to use, preferably the gross structure thing is made sheet form.Traditionally, " lamellar " refers to and has thickness greater than 250 microns gross structure thing.Sheet material preferably will have the thickness that is about 0.5mm to 3mm, typically is about 1mm.

Gross structure thing of the present invention is made of the polymeric material that can absorb big quantity of fluid.(this polymeric material is commonly referred to hydrogel, hydrocolloid, or superabsorbent material).This gross structure thing preferably comprises unhydrolyzed in fact, absorption, the gelationus polymeric material of water-setting.Concrete polymeric material is discussed when narrating the relevant polymeric material that forms the precursor particle in the back.

As shown in figures 1 and 3, porous of the present invention, absorbability, polymerization gross structure thing comprises the granule that a kind of intergranular is crosslinked.Crosslinked of this intergranular is with two or more.Be typically in the present invention 10 or more a plurality of original independently precursor particle link together and the loose structure that forms.With the intergranular cross-linking agent precursor particle is linked together, keeping on the precursor particle physics under the bonded situation, the additional conditions that the polymeric material that utilizing is enough to make intergranular cross-linking agent and precursor particle reacts make between the precursor particle that constitutes granule and form cross-bond.

As shown in Figure 1, the crosslinked granule of intergranular is to be formed by a large amount of precursor particles.Owing to consider the size of the precursor particle that will select for use here, crosslinked of typical intergranular is by 10 or more a plurality of, be preferably by 50 or more a plurality of precursor particle constitute.Precursor particle composition of the present invention is from unitary form.The precursor particle may comprise granule, and is pulverous, globular, lepidiod, fibrous, granule or become blocky.Thereby the precursor particle can have shape arbitrarily, for example cube; Class is shaft-like; Polyhedral; Globular; Circular; Corneous; Irregular; (for example certain the grinding or the powdery product of powder grade) of the asymmetric shape of arbitrary dimension or have big greatest dimension/smallest dimension ratio, as needle-like, flakey, or fiber is thread, or the like.As shown in Figure 1 to Figure 3, the precursor particle is preferably with the powdered form granule or the scale fine separation powder-form of the meta-rule shape of arbitrary dimension.

Though the precursor particle can have the size of wide variation,, concrete particle size distribution and various sizes are selected.From purpose of the present invention in fact, the particle size of precursor particle has been done qualification, (for example with the ratio that makes it not have the big greatest dimension/smallest dimension as fiber, granular, flakey, or Powdered), the size of its precursor particle is to be determined by the width of mesh screening of sieve.For example, the precursor particle that the standard that has 600 microns mesh of staying is sieved for No. 30 is considered to have the particle size greater than 600 microns, by being arranged, No. 30 of 600 microns mesh sieves stay precursor particle in No. 35 sieves of 500 microns mesh, be considered to have the particle size between 500 and 600 microns, particle size less than 500 microns then should be arranged by the precursor particle that No. 35 of 500 microns mesh sieves are arranged.In most preferred embodiment of the present invention, the overall dimension scope of precursor particle is between 1 micron to 2000 microns, preferably between 20 microns to 1000 microns.

And from purpose of the present invention, the quality average particle size particle size of precursor particle (mass average particle size) quantitatively is important to the characteristics and the character of formed gross structure thing really.A kind of quality average particle size particle size of precursor particle of given sample just is decided to be the average particle size particle size based on the sample of quality.The method of determining a kind of quality average particle size particle size of sample is illustrated in the test method part in the back.The quality average-size of precursor particle is about 20 microns to 1500 microns usually, preferably 50 microns to 1000 microns.In embodiments of the present invention, the precursor particle has the quality average particle size particle size less than 1000 microns, is more preferably less than 600 microns, and best is less than 500 microns.In specific embodiments of the invention, the quality average-size of precursor particle is quite little (being that the precursor particle is meticulous).In certain embodiments, the quality average-size of precursor particle is more preferably less than 180 microns approximately less than 300 microns.In a typical embodiment,, have at least 95% granule to have particle size between 150 microns and 300 microns by weighing as can be known of precursor particle.In another embodiment, the weight by the precursor particle is calculated to rare 95% particle size that has between 90 microns and 180 microns.Narrow precursor particle size distribution is good, because when density increases, compares with the wide precursor particle size distribution with equal mass average particle size particle size, has the more gross structure of high-voidage owing to their higher void ratios have produced.

Material with big greatest dimension/smallest dimension ratio, for example the particle size of fiber is determined by their full-size usually.For example, if absorbefacient, polymer fiber (the promptly super fiber that absorbs) is used for then determining " particle size " with the length of fiber among the gross structure thing of the present invention.(fiber number that also can fiber and/or diameter explanation) in exemplary embodiments of the present invention, fiber has the length greater than 5mm, preferably between 10mm and 100mm, preferably between 10mm and 50mm.

In fact the precursor particle comprises water-fast, absorbefacient, the formation hydrogel, polymeric material.Be suitable as the particulate polymeric material of precursor here and comprise those, unsaturation, the material that acidiferous monomer is prepared by polymerisable.Such monomer comprises the unsaturation acid and the acid anhydride of the olefinic that contains the two keys of at least one carbon carbon olefin.Especially these monomers can be selected the unsaturation carboxylic acid and the anhydride of olefinic for use, alkene unsaturation sulfonic acid and their mixture.

Also available some non-acidic monomers prepares the precursor particle.Such non-acidic monomers may comprise, for example, contains the dispersible ester of water-soluble or water of acid monomer and does not comprise carboxyl or sulfonic monomer.Optionally non-acidic monomers may comprise the monomer that contains following functional group form: carboxylic acid or sulphonic acid ester, hydroxyl groups, acyl ammonia group, amine groups, itrile group and quaternary ammonium salt group.These non-acidic monomers are materials that people are familiar with, and are at large described by the utmost point, as the U.S. Pat of being delivered by Masuda etc. on February 28th, 1,978 4, the U.S. Pat 4,062 that November 13, Westerman delivered in 076,663 and 1977 year, 817, can be used as reference.

Alkene unsaturation carboxylic acid and carboxylic acid anhydrides monomer comprise the various acrylic acid by acrylic acid representative itself, methacrylate, ethylacrylic acid (ethacrylica acid), α-Lv Bingxisuan (alpha-chloroacrylica acid), alpha-cyanoacrylate, Beta-methyl acrylic acid (.beta.-methylacrylic acid), atropic acid, β-acryloxy propionic (beta-acryloxy propionic acid), sorbic acid (sorbicacid), α-chloro sorbic acid, angelic acid (angelic-acid), cinnamic acid, P-chloro cinnamic acid, β-steryl acrylic acid (beta-sterylacrylic acid), methylene succinic acid, citraconic acid (citraconic-acid), mesaconic acid, glutaconate, equisetic acid, maleic acid, fumaric acid, three carboxyl ethylene and maleic anhydrides.

Alkene unsaturation sulfonic acid monomer comprises aliphatic series or aromatic ethenyl sulfonic acid, for example vinyl sulfonic acid, allyl sulphonic acid, vinyl toluene sulfonic acid and styrene sulfonic acid, propylene and pib sulfonic acid, for example sulfoethyl acrylic acid, sulfoethyl methacrylate, sulfo-propyl group acrylic acid, sulfo-propyl group methacrylate, 2-hydroxyl-3-acryloxy propane sulfonic acid, 2-hydroxyl-3-isobutene. acyl-oxygen base propane sulfonic acid and 2-acrylamido-2-methyl propane sulfonic acid.

Be used for preferred polymer materials of the present invention and have a carboxyl.These polymer comprise hydrolysis starch-acrylonitrile graft copolymer, the neutral starch-acrylonitrile graft copolymer of part; Starch-acrylate graft copolymer; The neutral starch-acrylate graft copolymer of part; Saponified vinyl acetate-acrylate copolymer; The acrylonitrile of hydrolysis or acrylamide copolymer; Arbitrary product that slight network cross-linked is arranged of aforementioned copolymer, the neutral polyacrylic acid of part, the neutral polyacrylic slight crosslinked product that has of part.These polymer can be used independently, also can be with two or a plurality of monomer, and the form of mixtures of chemical compound is used or the like.These examples of material are disclosed in U.S. Pat 3,661,875; US4,076,663; US4,093,776; US4 is in 666,983 and US4,734,478.

As the best polymeric material of precursor particle is the polyacrylic acid that neutralized of part and the cross-linking products that slight network is arranged of their starch derivatives.Best is, the precursor particle includes from 50 to 95%, and the best is 75%, the neutral polyacrylic acid (being the sodium acrylate/acrylic acid polymer) that slight network cross-linked is arranged.

As mentioned above, preferable precursor particle be subjected to slight network cross-linked polymeric material.Network cross-linked causes the precursor particle in fact to be water can not be molten, and partly relevant to the characteristic of the absorbability of decision precursor particle and formed gross structure and extractible polymer content.Done detailed explanation in the U.S. Pat 4,076,663 that crosslinked method of polymer network and typical network cross-linked agent are mentioned in front.

Monomeric precursor particle can be produced with any traditional method.The method of typically producing monomer precursor particle had description in following data, these data are: by Kerryn A.Brancdt, Steven A.Goldman, disclosed again with ThomasA.Inglin on April 19th, 1988, be entitled as " be used for the aquogel type of absorbent structures polymer architecture " United States Patent (USP) Re32,649; TsuneoTsubakimoto, Tadao Shimomura, with Yosio Irie, deliver on November 25th, 1986 in the United States Patent (USP) 4666983 of on May 19 disclosed being entitled as in 1987 " absorbent article " and same authors, the U.S. 4 that is entitled as " the continuous production method of cross linked polymer ", 625, No. 001 patents.These patents here are suitable as a reference.

The better method that forms the precursor particle is to adopt the polymerization that comprises watery solution or other solution.United States Patent (USP) Re32 as mentioned above, described in 649, watery solution polymerization process comprises with a kind of watery reactant mixture and carries out polymerization to form the precursor particle.Be enough to produce by watery reactant mixture is applied that water can not be molten in fact in mixture, the polymerization condition of slight network cross-linked polymeric material is ground formed mass polymerization material or broken to form one precursor particle thus.

More precisely, the polymerization of producing the watery solution of single precursor particle comprises the preparation of watery reactant mixture, carries out polymerization to form suitable precursor particle in mixture.A composition of this reactant mixture is the monomer material that contains acid groups, and it will form " the main chain composition " of the precursor particle of desire production.Reactant mixture comprises 100 parts monomer material by weight substantially.Another composition of watery reactant mixture comprises a kind of network cross-linked agent.Be used to form the U.S. Re32 that Brandt that the network cross-linked agent of precursor particle mentions etc. is delivered in the above, No. 649 patents; 4,666, No. 983 patents of the U.S. that Tsubakimoto etc. deliver; 4,625, No. 001 patent of the U.S. of delivering with Tsubakimoto etc. all has more detailed description.By monomer mol percentage total in the watery mixture, the network cross-linked agent is presented in the watery reactant mixture (in other words with the quantity of 0.001 mol percentage to 5 mol percentage usually, weight in monomer material is 100 parts, and the network cross-linked agent is 0.01 to 20 part by weight).

A kind of composition of optional watery reactant mixture comprises a kind of radical initiator, this initiator comprises peroxide, for example, sodium peroxide, potassium peroxide, and Ammonium persulfate., the peroxide decoyl, benzoyl peroxide, hydrogen peroxide, cumene hydroperoxide (Cumene hydroperoxides), the tert-butyl group two is crossed phthalic acid ester (tertiary butyldiperphthalate), uncle's fourth perbenzoate (tertiary butylperbenzoate), peracetic acid sodium salt (Sodium Peracetate), percarbonic acid sodium salt (Sodium percarbonate) etc.The optional composition of other of watery reactant mixture comprises various unsaturated in fact nonacid monomers that close altogether that contain the ester of monomeric acidic functionality, or other contain non-carboxyl or sulfonic acid functional group close monomer etc. altogether.

Watery reactant mixture applied is enough to make it to produce that in fact water can not be molten, absorbefacient, goes through in three patents that the gelatinous polymerizing condition that the polymeric material of slight network cross-linked is arranged, these polymerizing conditions were mentioned in the above.Polymerizing condition is usually directed to heating (hot activation technology), to reach 0-100 ℃ of polymerization temperature, preferably from 5-40 ℃.The condition that keeps watery reactant mixture to play polyreaction also may comprise, for example: a reactant mixture or its part are applied polymerization activation irradiation, this irradiation can adopt any habitual form, as radioactive, electronics, ultraviolet light or electromagnetic radiation, they are all optional to be used for carrying out polymerization and to activate irradiation.

Preferably make the acidic functionality neutralization of formed polymeric material in watery reactant mixture.Neutralization reaction can be carried out with the method for any routine, should make by reaction to be used for forming polymeric material, contains at least 25 mol percentages of the monomeric sum of acidic-group, is more preferably at least 50 mol percentages and is subjected to.Salifiable cation neutralization.As mentioning,, comparatively detailed discussion was arranged in 649 in the above by United States Patent (USP) Re32 that the people delivered such as Brandt.Such salt-forming cation comprises: as, alkali metal, the ammonium of ammonium and replacement, and amine etc.

Producing the precursor particle with watery solution polymerization process is preferably, but also can adopt the heterogeneous polymerization treatment technology, carries out polymerization such as the method for inverted emulsion polymerization or reverse suspension polymerization.In inverted emulsion polymerization or reverse suspension polymerization, above-mentioned watery reactant mixture is suspended in a kind of water with the form of microdroplet can not be molten mixed, and inert organic solvents is for example in the substrate of cyclohexane extraction.This precursor particle is spherical in shape usually.Reverse suspension polymerization equals the United States Patent (USP) 4,340,706 delivered July 20 nineteen eighty-two at obaysashi; Flesher equals in the United States Patent (USP) 4,735,987 that the United States Patent (USP) 4506052 delivered on March 19th, 1985 and Morita equal to deliver on November 5th, 1988 detailed explanation was arranged all, can be used as reference.

In a preferred embodiment of the invention, be used for forming that the precursor particle of crosslinked of intergranular comes down to do.Here, " dried in fact " its implication is that the precursor particle has certain liquid content, contains water or other solution usually, but this content by the precursor particle weight less than 50%, less than 20% relatively good, preferably less than 10%.Usually, the liquid content of precursor particle by the precursor particle weight in the 0.01%-5% scope.The precursor particle of list-body can for example be dried with heating with the method for any routine.In addition, when adopting watery reactant mixture to form the precursor particle, can from reactant mixture, water be removed with Azotropic distillation method.Also can be handled the watery reactant mixture that contains polymer with make dehydrant as methanol.Also can combine use to above-mentioned two kinds of drying meanss.Then, will carry out fragmentation or grinding through the blocks of polymeric material of dehydration, and come down to do with formation, water is undissolved, the precursor particle of absorbefacient gel polymeric material.

The present invention selects for use those to have the precursor particle of high absorbent capacity.So, high absorbability is also arranged by the formed gross structure thing of these precursor particles." absorbability " refers to a kind of given polymeric material and absorbs the ability that is in contact with it liquid.Absorbability has very big variation with the mode that character and it of absorption liquid contacts with polymeric material.From purpose of the present invention, according to experimental technique cited below, absorbability is defined as, be unit with the artificial urine gram number of every gram polymeric material, the amount (artificial urine defines and sees below) of any given artificial urine that polymeric material absorbs.The defined precursor particle of the present invention is that every gram polymeric material has 20 grams at least, and the precursor particle of the artificial urine absorbability of 25 grams is preferably arranged.Here used typical precursor particle polymeric material has the absorbability that every gram polymeric material absorbs 40 grams-70 gram urine.With the gross structure thing that the precursor particle with such high absorbent capacity is made, particularly suitable is at absorbent article, in absorption component and the assimilate.Because the gross structure thing of the combination that is made of this precursor particle according to definition regulation, can hold a large amount of discharge liquid (as urine) amount satisfactorily.

Can do the surface to single precursor particle and handle, for example: Alexander etc. disclose the have poly-quaternary amine precursor particle surface processing method of (poly-quaternary amine) in the United States Patent (USP) of delivering on April 25th, 1,989 4,824,901.If carry out surface treatment, just can make the precursor particle surface crosslinked better, as: the United States Patent (USP) that is entitled as " absorbing particles " 4,666,983 that Tsubakimoto etc. were delivered on May 19th, 1987; The United States Patent (USP) of delivering to be entitled as " water absorbent " with on March 29th, 1,988 4,738,478 all can be used as reference.At United States Patent (USP) 4,666, mention in 983, surface crosslinking agent can be applied on the precursor particle, and make polymeric material reaction on surface crosslinking agent and the precursor particle surface, thereby make individual precursor particle surface crosslinked.

The same polymeric material that does not need to make all precursor particles of crosslinked of intergranular all to have identical performance constitutes.For example: some precursor particle can be made of starch-acrylate graft copolymer (Starch-acrylic acid graft copolymer), and other precursor particles can the polymeric material of the local neutral polyacrylic acid product of network cross-linked constitutes by having a little.And the precursor particle of the one-tenth granule that intergranular is crosslinked is in shape, absorbability, or its what its performance in office, and characteristic aspect can be different.In a preferred embodiment of the invention, the polymeric material that the precursor particle contains is made of the local neutral polyacrylic acid product with slight network cross-linked, and each precursor particle has the performance in week mutually.

Intergranular of the present invention is crosslinked granule also to contain a kind of intergranular cross-linking agent, it is applied on the precursor particle, and with the polymeric material reaction of precursor particle, make the combination that keeps between the precursor particle physically simultaneously.Above-mentioned reaction makes between the precursor particle and forms cross-bond, and this cross-bond is present in (promptly between different precursor particles) between particle.Scope of the present invention needn't be bound by theory or restriction, can believe, the reaction of intergranular cross-linking agent and precursor particle polymeric material will form the cross-bond (being the intergranular cross-bond) between the polymeric bonds of different precursor particles.For the selected polymer of this paper, very clear, the intergranular cross-linking agent will make between the carboxyl of original self-existent precursor particle and form cross-bond.Put into practice as can be known from theoretical and the present invention, intergranular cross-bond and the carboxyl effect of polymeric material will form the covalent crosslink between the different precursor particle polymeric chains.Usually, by cross-linking agent functional group and the effect of polymeric material carboxyl, form ester, amide (imines) or urethane group, its result will cause the covalent chemical cross-bond to form.In the embodiment that selects for use, can think that it is the chemical bond that forms ester.Therefore, Xuan Ding intergranular cross-linking agent be those can with carboxyl reaction in the selected polymer to form the preparation of ester.

The useful intergranular cross-linking agent of the present invention is those preparations that can react with the polymeric material of the precursor particle that is used for forming crosslinked of intergranular.Suitable intergranular cross-linking agent can comprise many different preparations, for example: the chemical compound with at least two polymerizable double bonds; The chemical compound that has the functional group that a polymerizable double bond and at least one and polymeric material react at least; Have two chemical compounds with the functional group of polymeric material reaction at least; Or polyvalent metallic compound.United States Patent (USP) 4,076,663 and Re32 that the used cross-linking agent of the present invention was mentioned in front, existing detailed narration in 649.Can be used as reference.The intergranular cross-linking agent also can comprise with the reaction of the polymeric material of precursor particle to form the monomer (mentioning) of polymerization crosslinking key as the front.

Appear on the material of precursor particle or in the material under the situation of (being the polymerization linkwork) at carboxyl, the intergranular cross-linking agent of selecting for use should be each can with the molecule of carboxyl reaction in have the liquid of two functional groups at least.Selectable intergranular cross-linking agent comprises polyhydric alcohol, for example: ethylene glycol, two ethylene glycol, triethylene glycol, TEG, Polyethylene Glycol, glycerol (1,2, the 3-glycerol), polyglycerol, propylene glycol, 1, the 2-propylene glycol, 1, ammediol, the trihydroxy methyl propanol, diethanolamine, triethanolamine, polypropylene oxide oxygen ethylene-oxypropylene block copolymer, fatty acid esters of sorbitan, polyoxyethylene sorbitan fatty acid ester, tetramethylolmethane, and sorbitol, the poly epihydric alcohol ether compound, for example: Ethylene glycol diglycidyl ether, polyethyleneglycol diglycidylether, the glycerol polyglycidyl ether, two glycerol polyglycidyl ethers, many glycerol polyglycidyl ether, the sorbitol polyglycidyl ether, the tetramethylolmethane polyglycidyl ether, and propylene glycol diglycidylether; The polyaziridine chemical compound, for example: 2, the two methylol butanols-3 of 2-(3-(different-aziridine) propionic ester], 1,6-hexamethyl toluene diethylidene urea and diphenyl-methane-two-4,4 ＇-N, N ＇-diethylidene urea; Halogenated epoxide, for example: chloropropylene oxide and Alpha-Methyl fluorinated alcohols; The polyaldehyde chemical compound, for example: glutaraldehyde and Biformyl; Polyamine compounds, for example: ethylenediamine, diethylenetriamines, trien, tetren, penten, and polyethylene imine based; Polyisocyanate compounds, for example: 2, two isocyanates of 4-toluene and the two isocyanates of hexa-methylene.

Can adopt by a kind of intergranular cross-linking agent of selecting in the above-mentioned group, or two or more mutual in fact nullvalent intergranular cross-linking agent.Here the used special-purpose intergranular cross-linking agent that contains the carboxyl polymeric material that has is: ethylene glycol, glycerol, trimethylolpropane, 1,2-propylene glycol and 1, ammediol.

The deal of the intergranular cross-linking agent that uses among the present invention is the weight by per 100 parts of precursor particles, and it is within 0.01 part to 30 parts scope, and is better between 0.5 part to 10 parts, preferably between 1 part to 5 parts.

Other material or preparation also can be used for producing crosslinked of intergranular among the present invention, or are promoting and helping to play promoter effect in intergranular cross-linking agent and the reaction of precursor particle polymeric material, or use with the intergranular cross-linking agent as associated complex.For example, water can use together with the intergranular cross-linking agent.Water have promote the intergranular cross-linking agent formerly the plasmid sub-surface evenly spread, and make the intergranular cross-linking agent infiltrate the function in precursor particle surface district.Strengthen combination physically between the precursor particle in the granule before water also can promote to react, make driedly, the crosslinked granule of expansible intergranular has integrity.Among the present invention, be 100 parts with the weight of precursor particle, used water is less than 20 parts (0-20 parts) by weight, between 0.01-20 part better, preferably between 0.1-10 part.In fact, the consumption of water is to become with the kind of polymeric material and the particle size of precursor particle.

Organic solvent also can use together with the intergranular cross-linking agent.Organic solvent is to be used for impelling the even diffusion on the plasmid sub-surface formerly of intergranular cross-linking agent.Organic solvent is preferably used hydrophilic.Being used for hydrophilic organic solvent of the present invention comprises: lower alcohol, for example: methanol, ethanol, n-propanol, isopropyl alcohol, n-butanols, isobutanol, the second month in a season-butanols and t-butanols, ketone, for example: acetone, methyl ethyl ketone, methyl iso-butyl ketone (MIBK); Esters, for example: dioxane, oxolane and ether; Amide, N for example, dinethylformamide and N, N-diethylformamide; And sulfoxide, for example: dimethyl sulfoxide.The deal of used hydrophilic solvent is: by the precursor particle weight is 100 parts, can be less than 60 parts (0-60 parts), gets between 0.01-60 part better, preferably gets between 1-20 part.The actual amount of used hydrophilic organic solvent will change with the kind of polymeric material and the granular size of precursor particle.

The intergranular cross-linking agent also can mix use with water and one or more hydrophilic organic solvents.Find adopt water/intergranular cross-linking agent solution can make cross-linking agent have the maximum osmosis that enters precursor particle surface district, and hydrophilic organic solvent/intergranular cross-linking agent to have minimum crosslinked osmosis.But in order to control the amount that the intergranular cross-linking agent infiltrates precursor particle surface district, it is suitable that above-mentioned three kinds of preparations are mixed use.Have found that water is high more to the ratio of organic solvent, the infiltration of cross-linking agent is just strong more, the just just reduction more of absorbability of big more resulting macrostructure thing of the liquid stability of gross structure thing under pressure.Typically, the ratio of water and hydrophilic organic solvent should be in 10: 1 to 1: 10 scope in solution.Weight in the precursor particle is 100 parts, and the deal of use hydrophilic organic solvent/water/intergranular cross-linking agent solution should be less than 60 parts (between 0-60 parts), with better between 0.01-60 part, preferably between 1-20 part.

Other optional composition also can mix use with the solution that contains the intergranular cross-linking agent.For example: can add initiator, catalyst, nonacid comonomer.Some materials that share are at United States Patent (USP) Re.32, narrate in 649.

Produce the porous that contains crosslinked of intergranular, the method for absorbefacient polymerization gross structure thing may further comprise the steps: the precursor particle that preparation this paper had stated; Part to the precursor particle applies the intergranular cross-linking agent; Make the precursor particle physically in conjunction with to form granule; Make a shaping; And the intergranular cross-linking agent and the polymeric material of the precursor particle of granule are reacted, the combination on the maintenance precursor particle physics is with the cross-bond between the polymerization linkwork that forms different precursor particles.

The intergranular cross-linking agent is applied on the precursor particle.Can adopt anyly liquid can be applied to the technology and equipment that material gets on the intergranular cross-linking agent is applied on the precursor particle, comprise: be coated with, spread, spray, drip, spray, condense or the intergranular cross-linking agent is immersed on the precursor particle.Here the meaning of " be applied to above " speech is, make on the zone of part surface at least of the precursor particle that is tied to have the intergranular cross-linking agent.Therefore, the intergranular cross-linking agent can be applied on the part of precursor particle, or on all precursor particles, promptly only on the part surface of part or all of precursor particle, or on the whole surface of part or all of precursor particle.Preferably the intergranular cross-linking agent is coated onto on most precursor particles, preferably on the whole surface of whole precursor particles, renders a service intensity and density so that strengthen the bonding of intergranular cross-bond between the precursor particle.

In a preferred embodiment of the invention, after being added to the intergranular cross-linking agent on the precursor particle, to make intergranular cross-linking agent and precursor mix particles by various stirring techniques, to guarantee that the precursor particle all is coated with the intergranular cross-linking agent, then the bonding of cross-bond is renderd a service between the precursor particle, and intensity and density can be strengthened.Mixing can be used various technology and equipments, as finishing with known various agitators or kneader.

Before being applied to the intergranular cross-linking agent on the precursor particle; during this time or afterwards; to make earlier and be combined together to form a granulous gross structure of group on the precursor particle physics; use " combination physically " vocabulary to be shown here and indicate the precursor particle as putting together with any different mode and the component units of spatial relationship; and keep contacting with each other, to form single conjugate (granule or gross structure thing).

A kind of bonding agent is applied on the precursor particle, and the precursor particle is contacted physically in that part of surface that scribbles bonding agent at least, and the precursor particle is combined better.Preferably when the precursor particle is put together,, and bonding agent is sticked together the polymeric material of precursor particle by the effect of surface tension of liquid and/or because superficial expansion causes the winding of polymeric chain.The used bonding agent of the present invention comprises: hydrophilic organic solvent, and specifically low-molecular-weight alcohols, for example: methanol, ethanol, isopropyl alcohol; Water; The mixture of hydrophilic organic solvent and water; Aforementioned some intergranular cross-linking agent; Volatile hydrophobic organic compound, as: hexane, octane, benzene or toluene; Or their mixture.Bonding agent is water, methanol, isopropyl alcohol, ethanol, intergranular cross-linking agent such as glycerol preferably, or their mixture.Typical bonding agent comprises a kind of mixture of intergranular cross-linking agent, and the step that applies the intergranular cross-linking agent can be carried out synchronously with the step that applies bonding agent.

Can adopt anyly to be used for that liquid is coated onto the technology and equipment that material gets on bonding agent is added to the precursor particle, for example with being coated with, spreading, spraying, dripping, spraying, condensing or bonding agent being dipped on the precursor particle.Bonding agent to be applied on each the part surface at least of at least one precursor particle that need to connect.To will be coated onto great majority, on the whole surface of preferably all precursor particles in conjunction with profit.Usually adopt any stirring technique and mixing plant to make bonding agent and precursor mix particles, be coated with bonding agent fully to guarantee the precursor particle.

After plasmid was coated bonding agent in the ban, just can in all sorts of ways made it to touch physically together, for example: can only with bonding agent particle be kept in touch together.In addition, also available gravity guarantees the contact between the precursor particle, granule can also be placed on one and have in certain volumetrical container to guarantee the contact between the precursor particle.

In addition, the constraint of precursor particle by physically can be made it combining of nature, so that they contact with each other, for example: the precursor particle can be close to and be filled in the container that fixed volume arranged, and make the precursor particle contact with each other physically.In addition, can be in conjunction with method above-mentioned with gravity from physically connecting plasmid at first.Also can make the combination physically of precursor particle do, or they be sticked together by means of binding agent (for example a kind of close-burning material that can be water-soluble) by electrostatic attraction.Also the precursor particle can be attached on the substrate, the precursor particle be contacted with each other with substrate.

Constitute among the embodiment of gross structure thing of the present invention at another, the granule of precursor particle is pressed various geometric spaces relations be shaped, and compacting, to form a kind of definite shape that has, size, and/or the granule of density.Can make a shaping with any traditional forming technique, selected manufacturing process comprises die casting, die casting, appearance operation.Die casting and die casting technology normally import the precursor particle and give in the molding chamber, and granule is exerted pressure, and make granule consistent with the die cavity shape.Here used concrete die casting technology comprises extrusion die casting, cast, extrusion molding or lamination, for example, a large amount of precursor particles can be added in the container of a mold cavity with fixed volume, and granule extruding made it to have the shape consistent with die cavity, so that formed gross structure thing has the shape that is limited by the die cavity shape.Forming technique comprises carries out various operations limiting its shape to granule, and/or size, and/or density.Available herein concrete forming technique is: rolling, forging and pressing, extruding, spinning, and operations such as coating or punching press, for example the granule compound of precursor particle and intergranular cross-linking agent can form flaky aggregation by a pair roller.In addition, a compound is pushed by orifice plate, to form a kind of have shape and the corresponding aggregation of orifice plate.Also have, the granule compound can be watered on a surface aggregation that has necessarily required shape or configuration of surface with formation.These technology can be combined respectively or all, to form the aggregation of setting.Any suitable equipment of the prior art all can be used to carry out above-mentioned operation, these operations can heat in a part material or equipment and/or refrigerative situation under finish.

In a preferred embodiment of the invention, with the precursor particle, the intergranular cross-linking agent, the granule compound of water and certain hydrophilic organic solvent adds in the feed hopper of a traditional extrusion equipment.The example of extrusion equipment is mentioned in Figure 12-14 of the 331st page of " polymeric material principle " second edition that McGraw-Hill books company 1982 publishes, can be used as reference.With granule compound extruding,, deliver to again in a pair of roll that is driven with fixing (but variable) slit, so that granule is squeezed into lamellar by the orifice plate of extruder.Then, again this thin slice is processed into certain-length, makes and have the gross structure thing that necessarily requires size, shape and/or density.

When applying the intergranular cross-linking agent or afterwards, the precursor particle combines the formation granule physically, then granule is shaped, the intergranular cross-linking agent just reacts with the polymeric material of the precursor particle of granule, keeping on the precursor particle physics under the bonded situation, forming the crosslinked bonding between the precursor particle and form the crosslinked aggregation gross structure thing of intergranular.

Must the reaction between intergranular cross-linking agent and the polymeric material be activated,, form the crosslinked aggregation of intergranular to realize the crosslinked bonding action between the different precursor particles fully.Though, can use irradiation (for example, ultraviolet rays, gamma-ray irradiation) or activate cross-linking reaction, the most handy hot activation (heating) cross-linking reaction by a kind of catalyst as catalyzer contact agent and activator.Promote reaction in the time of heat activation and remove any volatile matter that exists in the compound.This reaction condition generally includes bonded precursor particle and intergranular cross-linking agent heating certain hour, and keeps uniform temperature.The step of heating can adopt various equipment, carries out as baking oven or dehydrator.

Usually, in order to finish cross-linking reaction, be heated to the temperature more than 90 ℃ and keep sufficient heat time heating time, this will be effective to reaction.Concerning the polymeric material of each concrete intergranular cross-linking agent of group and precursor particle, if heating-up temperature is too low or the time is too short, then reaction is not fully carried out, cause interparticle crosslinked bonding less or a little less than, thereby the permeability of liquid reduces when making the gross structure thing expand.If temperature is too high, then may reduce the absorbability of precursor particle, or the network cross-linked of these precursor particles, may be reduced to according to concrete polymeric material and make the gross structure thing can not absorb a large amount of liquid.In addition, if time and temperature are incorrect, the grade extracted that generates aggregation is improved, thereby the probability that forms the gel caking increase.Therefore, reaction is carried out in 120 ℃ of-300 ℃ of scopes usually, and is better between 100 ℃-250 ℃.Finish the time of reaction, do not having under the situation of catalyst normally 5 minutes to 6 hours, better with 10 minutes to 4 hours.

For preferable precursor particle polymeric material, the neutral polyacrylic product that slight network cross-linked is arranged of part, with preferable intergranular cross-linking agent, for example glycerol or trimethylolpropane, this reaction condition is respectively: temperature is from 170 ℃-220 ℃, heated 3 hours to 30 minutes, preferably temperature is between 190 °-210 ℃, and the response time is 75 minutes to 45 minutes.Whether the actual temperature and time that adopts will adopt catalyst to help reaction with the used intergranular cross-linking agent of the polymeric material of concrete precursor particle, and the thickness of gross structure thing or diameter and change.

Can add initiator and/or catalyst cross-linking reaction, and reduce the amount that the precursor particle is linked up desired response time and/or reaction temperature and/or used intergranular cross-linking agent with promotion intergranular cross-linking agent.But reaction is not have to carry out under the situation of catalyst usually.

During reactions steps is carried out, need keep the combination physically of precursor particle, so that form enough intergranular cross-bonds.If during reactions steps is carried out, the precursor particle is subjected to being enough to make it isolating power or stress, then just may not form cross-bond (intergranular cross-bond) between the precursor particle.During reaction, the power or the stress that significantly make separate particles be guaranteed not introduce, the combination physically of precursor particle need be kept really.

As a kind of optional and step is preferably forming porous, in the method for absorbefacient polymerization gross structure thing, do the surface to component-precursor particle of gross structure thing and handle.For example April in 1989 Alexander on the 25th etc. at United States Patent (USP) 4,824, the surface treatment method of the polymer particles that polymerization one tetravalence amine is arranged is disclosed in 901.In a typical method, to make near the polymeric material that is present in the precursor particle surface surface-crosslinked at least.These methods are disclosed in the United States Patent (USP) 4,666,983 that Tsubakimoto on the 19th May in 1987 etc. are entitled as " absorbing particles "; With on March 29th, 1988 same author being entitled as in " water absorbent " United States Patent (USP) 4,734,478, can be used as reference.Owing to utilized surface-crosslinked step, make when preventing to expand, to cause having obtained improvement aspect the gross structure composition deformation among the present invention.Best, make the intergranular cross-linking agent that puts on the precursor particle also serve as surface crosslinking agent, the surface is also crosslinked simultaneously so that gross structure forms.

As previously discussed, the method step of producing the gross structure thing does not need to be undertaken by any order specified, and each step also can be carried out simultaneously.

In next preferred embodiment, applying the intergranular cross-linking agent carries out simultaneously with making on the precursor particle physics bonded process, compound is shaped, and formation has certain shape and needed density, then is the polymeric material reaction of intergranular cross-linking agent and precursor particle.After finishing above step, at once or after the granule aggregation is parked a period of time, form the gross structure thing simultaneously and make works surface-crosslinked.Specifically, the precursor particle is added in the container, and with the intergranular cross-linking agent that is sprayed on the precursor particle, water and hydrophilic organic solvent mix, and form an aggregation.The intergranular cross-linking agent, water and hydrophilic organic solvent are as the bonding agent of precursor particle.The intergranular cross-linking agent also serves as surface crosslinking agent.Then, adopt above-mentioned extruding and rolling technology to make granule (promptly bonded precursor particle and watery mixture) form tablet with certain density.Afterwards, make intergranular cross-linking agent and polymeric material reaction,, thereby form the gross structure that intergranular is cross-linked into granule, and make the surface of the precursor particle of formed gross structure become surface-crosslinked simultaneously with the cross-bond between the formation precursor particle by heating.

In some cases, formed gross structure thing may be had a few hard and crisp.For this reason, can obtain rubber-like gross structure thing with several method.For example: after finishing the intergranular cross-linking reaction, certain plasticizer can be added in the gross structure thing, suitable manufacturing methods has: water, high-molecular weight hydrophilic organic solvent (as, glycerol, 1, ammediol, or ethylene glycol), or polymer fluid (as, polyvinyl alcohol or Polyethylene Glycol), or their mixture.Available various method is added plasticizer in the gross structure thing to, for example adopt spray, to smear, spray, soak, pour into solution first-class at the gross structure thing.In addition, if water during as plasticizer, can add by the environment (being that relative humidity is higher than 70%) that the gross structure thing is placed high humility.Plasticizer also can add in the compound before the reaction that contains polymerisable monomer, and then reaction again makes monomer form the polymeric cross-bond of intergranular.In this case, plasticizer is just penetrated in the intergranular cross-bond structure during cross-linking reaction.Plasticizer dosage is to decide with the concrete plasticizer that is adopted in the solution.In general, per by weight 100 gram precursor particles can contain 0.01 part to 100 parts plasticizer.

As Figure 1-3, formed gross structure thing has hole (part of deceiving in the micro-photograph) between adjacent precursor particle.Hole is to make liquid by the small gap between the adjacent precursor particle that enters into gross structure thing inside.So can form hole in the gross structure thing is because the precursor particle " does not connect airtight " or be together adjacent fully, can not eliminate hole even press.(the piling up efficient less than 1 of precursor particle) hole is littler and form many interparticle capillary tubies of precursor that are in than the precursor particle of forming usually, and it is with the inside of liquid transfer to the gross structure thing.

Hole is being connected to each other mutually by the passage that is interconnected between the hole, these passages make the liquid that touches the gross structure thing be transferred to the other parts of gross structure thing by capillary force (for example forming capillary channel), make it absorb the whole volume that can use the gross structure thing aspect the liquid.And when works expanded, hole made liquid go by the precursor particle layer of gross structure logistics to the initial point that contacts away from liquid with the passage that is interconnected.Therefore, because the existence of the hole and the passage that is interconnected can think that the gross structure thing can permeation liquid.

For a kind of given precursor particle size distribution, the numerical value of hollow sectors (total measurement (volume) that promptly comprises hole and passage) is very little.Usually, the distribution of sizes of precursor particle is narrow more, and the ratio in cavity is just high more, therefore, in order to form high hollow sectors under the situation that increases density, need make the precursor particle have the particle size distribution that is rather narrow.

Another feature of gross structure thing of the present invention is, the expansion of gross structure thing is isotropic usually, even be subjected under the moderate pressure effect, liquid storage on the gross structure thing and with it contact all is like this.At this, isotropism expands and is meant that when humidity, the expansion of gross structure thing is always identical in all directions.It is a key character of gross structure thing that isotropism expands, because both made when expanding, keeps relative geometry and spatial relationship between precursor particle and the hole.Therefore, in use, capillary channel had both made and had not amplified also can keep intact (when in fact expanding, it is big that hole and precursor particle become).Therefore, the gross structure thing can permeate and/or carry and surpass liquid itself that can bear, and does not form the gel caking.

There are indications,, in the gross structure thing cross-bond that forms is made the stable factor of fluid in the gross structure thing (being liquid) just originally independently between the precursor particle.Here " fluid stable " speech refers to the gross structure thing that contains the intergranular cross-linking agent when contacting with aqueous humour or expanding (have and/or do not have stress), in fact remain intact harmless (that is, the precursor particle of most independent elements keeps still linking together).Though the meaning of fluid stability is, most precursor particles will remain attached to together, and preferably all precursor particles that are used for constituting the gross structure thing will remain attached to together.But if when having other granule to be agglomerated on this gross structure thing by water subsequently, then some precursor particle can be separated from the gross structure thing, and this also should be fine.

Liquid stabilising is a key character of gross structure thing of the present invention, because it makes the relative structure that all keeps it under the state that aggregation is or expansible, it makes composition-precursor particle remain unchanged.To some final products, for example absorption component or assimilate, liquid stabilising is useful to reducing gel caking aspect, because liquid stabilising also keeps cohesion when even the precursor particle is contacted with liquid, and make people utilize in granule originally independently subparticle, introduce cohesion caking composition and increased the Liquid Absorption rate of final gross structure thing.

The liquid stabilising of aggregation gross structure thing can be measured with a few step programs.Observe the initial dynamic response of aggregation granule gross structure when contacting, observe the equilibrium state of granule gross structure thing after the complete expansion then with aqueous humour.Based on these data with the method for determining liquid stabilising in the back the test method part described.

In the use, attached on the gross structure thing or the liquid that is in contact with it is permeated by the precursor particle or be transferred to the other parts of gross structure thing by micropore, liquid is subjected to other precursor particle penetration or is transferred on other absorbing component that is adjacent by the gross structure thing there.

Fig. 4-6 represents an alternative embodiment of the invention, and wherein, the precursor particle has different shapes and component, and the precursor particle is made up of erose granule and fiber (for example super fiber that absorbs).In the embodiment of Fig. 4-6, the absorption fiber that fiber can adopt the ArCo company by German Wilmington to obtain.Fig. 4 represents a kind of total shape of gross structure thing.As shown in Figure 4, fiber has formed an a kind of structure of an essay, wherein forms less hole between granule, and forms bigger hole around fiber.Fig. 5 has represented the shape and the size of hole in more detail, and granule and fiber intergranular are crosslinked among the figure.Fig. 6 is illustrated in the gross structure thing, owing to the combination that has increased fiber and granule/fiber has formed big hole and passage.

The super mixed number magnitude relation that absorbs fiber and microparticle can have wide variation, for example can form to have only the super gross structure thing that absorbs fiber, and this makes formed gross structure thing have the non-outward appearance of spinning fibrous web-like.In the embodiment shown in Fig. 4-6,, contain the super absorption fiber of 0.1%-50%, and it is more suitable to contain 0.5%-10% in the gross weight of precursor particle.

When super absorption fiber contains some precursor particle, when fiber and other precursor mix particles are got up, fiber and other precursor particle are mixed fully so that fiber interweaves between many different precursor particles.

Fig. 7 represents another embodiment of gross structure thing of the present invention.Wherein, stiffener, for example fiber (fibrous or fibrous material) is embedded in the gross structure thing.Stiffener can increase through the intensity of expansible gross structure thing (for example integrity of structure).In certain embodiments, fortifying fibre also provides and liquid can be transferred to very soon the same member and/or the additional absorbent material of other similar wick that partly goes of gross structure thing.Reinforcement preferably constitutes (being also referred to as fortifying fibre) by various fibers, though other material, for example: filamentous, parcel, net, the non-net that spins, the woven design net, moire cotton fabrics etc. can be used from their enhancing characteristic.Fig. 7 represents an embodiment, and wherein polyester fiber interweaves in whole gross structure thing, and specifically, polyester fiber is included within the passage that interconnects, and this provides the integrity of structure after enhanced the expansion for the gross structure thing.

Various forms of fibrous materials all can be used as the stiffener of gross structure thing of the present invention.Any type of fibrous material that is suitable for use as in the tradition absorption product also is applicable to and is used in the gross structure of the present invention.These fibrous materials for example comprise cellulose fibre, the cellulose fibre of modification, artificial silk, polypropylene, polyester fiber such as polyethyleneterephthalate (DACRON), hydrophilic nylon (HydroFil) or the like.Except oneself discussed, other can be used for fibrous material of the present invention has, and the hydrophobic fiber of hydrophiling was for example handled through surfactant, or the thermoplastic fibres derivant of crossing with silica-treated, and for example, from various polyolefin, as polyethylene or polypropylene, polyacrylic acid, polyamide, polystyrene, the derivant of polyurethanes etc.In fact, the hydrophobic fiber of hydrophiling itself does not have good absorbability, therefore do not provide the net of enough absorbing powers, thereby do not utilized by traditional absorbent structures, but because it has good wick-like performance, make it be suitable for being adopted again by gross structure thing of the present invention, this is because in gross structure thing of the present invention, its gross structure has high Liquid Absorption rate and does not have the performance of gel caking, the wick-like performance of this fiber is compared with the absorbability of fibrous material itself, if not even more important, also be no less important.Synthetic fibers usually are chosen as the fiber composition of gross structure thing of the present invention, and majority is selected polyolefine fiber for use, and best is polyester fiber.

Other cellulosic fibre material that can be used for some gross structure thing is at the cellulose fibre through strengthening chemically.The cellulose fibre of strengthening on the better chemical is to become thick, and strand twiddles, the cellulose fibre of winding, and these fibers can be produced by the internal crosslinking cellulose fibre with cross-linking agent.To thick, strand is twisted with the fingers, twine, equaled to be entitled as the United States Patent (USP) 4 of " own characteristic being arranged; cross filament and manufacture method thereof " in the present invention by Dean December in 1989 9 days as the various cellulose fibres of hydrophilic fiber material, 888, open in 093, and the United States Patent (USP) 4 that was entitled as " making the method for the cross filament that self-characteristic is arranged that reduces residual matter and the fiber of production thereof " in December, 1989 such as Herron on the 26th, 889,595, be entitled as the United States Patent (USP) 4 of " manufacturing have the method for cross filament of own characteristic and the fiber of production " thereof on the 26th by in December, 1989 such as Schoggen, 889,596; The United States Patent (USP) 4 that was entitled as " method that manufacturing contains the wet interposed structure thing of unique fortifying fibre " by Bourbon etc. at December in 1989 on the 26th, 889,597 and Moore equal to be entitled as February 6 nineteen ninety the United States Patent (USP) 4 of " twisted weave chemistry reinforcing fibre and absorbent structures and method for making thereof ", in 898,647 literary compositions such as grade detailed description was arranged all.At this, can be with for referencial use.

Though, here use " hydrophilic " speech explanation be placed in the cellulose surface of liquid wets or the fiber of fiber surface situation (for example: whether water or aqueous liquid promptly spread out at fiber surface, and no matter fiber whether in fact permeation liquid or form gel).But, be the definition of using about the hydrophobicity (with moist) of related liquid and solid contact angle and surface tension aspect about the moist technical stipulation of material.To this, at Robert, Gould compiles, and has detailed discussion in the american chemical society publication thing that is entitled as " contact angle, wettability and viscosity " of distribution in 1964.The contact angle that " fiber or fiber surface are by the degree of liquid wets " speech had both referred to work as between liquid and fiber or surface is spent less than 90, also refers to cause situation about scattering by fiber surface naturally easily when liquid.Situation under normally these two conditions coexist.

Can be by fiber being imported the solution that has the intergranular cross-linking agent, by with give the precursor mix particles that scribbles the intergranular cross-linking agent earlier, or fiber is added in the gross structure thing by fibrous material being joined intergranular cross-linking agent/methods such as precursor particles mixture, in a preferential embodiment, fibrous material is rubbed with the hands gentle in intergranular cross-linking agent/precursor particles mixture, fibrous material is mixed fully, so that fibrous material spreads in the whole gross structure thing equably with solution.In addition, fiber preferably adds before the polymeric material reaction of intergranular cross-linking agent and precursor particle.

With the relative quantity of the fibrous material of precursor mix particles very big variation can be arranged.In the precursor particle weight is 100 parts, add the scope of fibrous material and can select part from 0.01-5, and serve as better with 0.5 to 2 part.

Porous, absorbefacient polymerization gross structure thing can on purpose be used for many occasions, and for example: the gross structure thing can be used for packing container; Drug release device; The wound clean device; Burning processing device ion interchange unit material; Construction material; Agricultural or gardening material are for example cultivated sheet or water one keeps material; And industrial goods; Sludge or oily dehydrant; Prevent the dewfall material; Drying and humidity control material etc.

Porous of the present invention, an absorbability polymerization gross structure thing and a carrier combine use, and be used for carrier of the present invention and comprise absorbing material, as: cellulose fibre.Carrier also can be the known carrier of any prior art, for example: non-net, the yarn net of spinning, foamed materials, polyacrylic fibre, polymer mesh thing with holes, synthetic fibers, thin metal layer, lactoprene etc.The gross structure thing can combine with carrier directly or indirectly, also can pass through combination physically or chemically, for example: paste, or chemical action adheres to the gross structure thing on the carrier.

Because porous of the present invention, the absorbent properties of the uniqueness that absorbability polymerization gross structure thing has, so it is specially adapted to make absorbent article, the absorbent cores of disposable absorbent article especially." absorbent article " is meant the goods that absorb and hold discharge liquor of body herein, refer specifically to those against or near wearing the health that carries the person places, be used for absorbing and hold the goods of the various juices that eject by health.And " disposable " absorbent article be meant those goods that just abandon after just once using (for example: novel absorbent articles with regard to its generally do not plan rinsing or preserve after the goods that reuse, though some material in the absorbent article or all still can circulate repeats or pieces together use).Fig. 8 represents a kind of embodiment of disposable absorbent article, as diaper 20.Here, " diaper " refers to its following overcover that carries of wearing of adult of baby or gatism.But self-evident, the present invention also can be used for manufacturing other absorbent article, for example: the panties that incontinent is used, urine pad, training trousers, diaper insert, sanitary towel, napkin, facial tissue or the like.Fig. 8 is the not perspective view of the diaper 20 of contraction state (having removed the rubber strap of all caused contractions etc. among the figure) that is in of the present invention, has removed part-structure among the figure so that can more clearly illustrate the structure of diaper 20.Diaper 20 shown in Figure 8 preferably includes: 38, one liquid-tight egative films 40 of top flat that can see through liquid, and egative film 40 sticks together with top flat 38, and absorbent cores 42 places between top flat 38 and the egative film 40; Rubber elastic cord 44; Paster shape securing member 46.Top flat 38, egative film 40, absorbent cores 42 and elastic brace web 44 can be assembled into a kind of shape of knowing, as: Kenneth B Buell on January 14th, 1975 be entitled as " the contractile side used of disposable diaper " and United States Patent (USP) 3, the diaper shape of explanation can be used as reference in 860,003.Also have a kind of shape of diaper to be disclosed in the United States Patent (USP) 4 that is entitled as " disposable absorbent article that has rubber leakage-proof part on chip " by Mohammed I Aziz and Ted L Blaney on February 28th, 1989,808,178, and in JIUYUE in 1987 22 days by Michael I Lawson in the United States Patent (USP) 4 that is entitled as " absorbent article that French cuff is arranged ", 695,278, be entitled as on March 28th, 1989 with John HForeman " absorbent article of encapsulation bag arranged " United States Patent (USP) 4,816, in 025, the content of these patents all can be in order to reference.

In an embodiment of diaper shown in Figure 8 20, top flat 38 and egative film 40 extend together, and identical length and wide is arranged, and its size is bigger than absorbent cores 42.Top flat 38 is superimposed and be seamed on the egative film 40 and form the periphery of diaper 20, defines the neighboring or the edge of diaper 20 by the periphery, and the periphery comprises edge, termination 32 and longitudinal edge 30.

Top flat (or deserving to be called cover plate) the 38th, fit, soft feeling is arranged, wearer's skin is not had zest, and top flat 38 is to see through liquid, allow liquid can promptly see through its thickness.Suitable top flat 38 can select for use very widely material to make, as use porous foam plastics, netted foam plastics, porous plastic sheeting, natural fiber (for example wood fiber and cotton fiber), the blended product of staple fibre (for example polyester or polypropylene fibre) or artificial and natural fiber etc.Top flat is preferably made of hydrophobic material, so that the skin of wearer is kept apart the liquid in the absorbent cores 42.

Top flat 38 preferably adopts 1.5 The long filament polypropylene fibre, for example adopt Wilmington, the Hercules-151 type polypropylene that the Harcules company of Delawrare provides.Refer to the sort of length at least at the fiber of 15.9mm (0.62 inch) by custom " filament fiber ".

Can make top flat 38 in many ways, for example with weaving, non-woven fabrics, knitting or other similar method.Top flat 38 is knitting preferably, and manufactures with the hot sticky method that technical staff in the textile technology is familiar with.The preferably every weight per square meter 18-25 of top flat gram is being at least every centimetre 400 gram along the machining direction dry tensile strength, and wet tensile, is every centimetre at least 55 at machining direction sidewards and restrains.

Egative film 40 is liquid-tight, and the most handy thin plastic foil is manufactured, and also can adopt other liquid-tight flexible material certainly.The thing that egative film 40 need prevent in the absorbent cores 42 institute's liquid of absorbing and holding and oozes out and get wet and contact with diaper 20, sheet for example, vest etc.Egative film 40 best thickness are the polyethylene film of 0.012mm (0.5 mil) to 0.05lcm (2.0 mil).Certainly the not saturating material of other liquid also can be used." softness " speech is next to the shin after referring to and putting on traditionally.

A kind of suitable polyethylene film is made by Monsanto chemical company, and has the commodity that trade mark is Film No8O20.Egative film 40 preferably is printed and/or removes gloss, to make it the outward appearance that it has cloth.And egative film 40 can be so that the aqueous vapor evaporation of overflowing from absorbent cores 42, but still can prevent that infiltration is by egative film 40.

The size of egative film 40 is decided by the size of absorbent cores 42 and correct diaper design size.In one embodiment.Egative film 40 has a kind of shape as the distortion hourglass, along the periphery extension of diaper 20, exceeds the distance of absorbent cores 42 about 1.3 centimetres to 2.5 centimetres (about 0.5-1.0 inches).

Top flat 38 and egative film 40 can link together in any suitable manner.Herein " connection " be meant top flat 38 directly be fixed to egative film 40, make top flat 38 directly link egative film 40 and be shaped, and by top flat 38 is fixed to an intermediate member, and intermediate member is fixed to egative film 40 successively, make top flat 38 non-directly with egative film 40 shape that is formed by connecting.In an embodiment who selects for use, top flat 38 and egative film 40 are peripheral with junctional complex (figure does not show) along diaper, for example: viscose glue or any junctional complex that other is known directly are fixed up them mutually, for example: a kind of even successive adhesive-layer, the adhesive-layer of discontinuous point configuration, sticking tablet that is separated into line or point etc. can be used for top flat 38 is fixed on the egative film 40.

The low back zone that paster shape securing member 46 is placed on diaper 20 usually remains on the wearer parts that link closely on one's body to provide a kind of with diaper.Paster shape securing member 46 can be any form of knowing, as: on November 19th, 1974 Kenneth B.Buell in United States Patent (USP) 3,848, disclosed restraint zone can be used as reference in 594.This securing member 46 or other diaper secure component be arranged on usually diaper 20 near corner.

Degree of tightness part 44 is arranged on the lateral edges place of diaper 20, and preferably edge 30 is provided with along the longitudinal, makes degree of tightness part 44 go to hold and keeps diaper 20 to abut the shank of wearer.In addition, degree of tightness part 44 also can be near two ora terminalis 32 places of diaper 20, can be used as belt this moment rather than as the cuff of thigh.For example a kind of suitable belt has been disclosed in David J.Kievit and Thomas F.Osterhage was entitled as in the United States Patent (USP) 4,515,595 of " disposable diaper that can tighten up elastic waist belt is arranged " on May 7th, 1985, can be used as reference.Make the method and apparatus of disposable diaper in addition, be disclosed in Keonneth B.Buell on March 28th, 1978 U.S.'s patent 4,081,301, can be used as reference with the collapsible elastic component of degree of tightness.

Degree of tightness part 44 is that elasticity is fixed on the diaper 20 with a kind of normal free shape collapsiblely, and degree of tightness part 44 shrinks effectively or tightens firmly diaper 20.Degree of tightness part 44 can be fixed into the contractile user mode of a kind of rubber-like with two kinds of methods at least, for example: degree of tightness part 44 can stretch under 20 one-tenth non-shrinking situations of diaper and be fixing, in addition, diaper 20 can shrink, for example by pleating,, degree of tightness part 44 is fixedly attached on the diaper 20 and being under the condition of non-lax or non-tensioning.

In the embodiment shown in fig. 8, degree of tightness part 44 extends along the length direction of diaper 20.In addition, degree of tightness part 44 can extend to the whole length of diaper 20, or anyly is suitable for providing an elastic lineal measure that tightens.The length of degree of tightness part 44 is decided by the design of diaper.

Degree of tightness part 44 desirable various forms, for example: the width of degree of tightness part 44 can change to 25 millimeters (10 inches) or more from 0.25 millimeter (0.01 inch); Degree of tightness part 44 can be made of the rubber material of sub-thread, also can comprise parallel or nonparallel multiply rubber material, and perhaps degree of tightness part 44 can be rectangular, or curved shape.Degree of tightness part 44 can be fixed on the diaper, for example with one of several methods of knowing: can use various bonding way, use ultrasonic bonding, be hot-pressed onto on the diaper 20, on the diaper 20 that also can stick with glue simply.

The absorbent cores of diaper 20 places between top flat 38 and the egative film 40.Absorbent cores 42 can make full range of sizes and shape (for example: strip, hourglass shape, asymmetric shape or the like), and constitute by various materials.But total absorptive capacity of absorbent cores 42 should satisfy the liquid load amount of desired absorbent article of design or diaper.In addition, the size of absorbent cores 42 and capacity can change to adapt to from the baby to the required scope of adult's wearer.Absorbent cores 42 comprises porous of the present invention, absorbability polymerization gross structure thing.

Adopt orthogonal absorbent cores among a kind of embodiment that selects diaper 20 for use.As shown in Figure 9, absorbent cores 42 preferably includes an absorption component 48, and this member 48 comprises seals net 50, and is enclosed in the porous in the net 50, absorbability polymerization gross structure thing 52.Gross structure thing 52 is encapsulated in to be sealed in the net 50, so that the probability that the precursor particle moves by top flat reduces to minimum, net 50 forms the acquisition of the additional transfer layer of liquid of one deck with increase liquid between top flat 38 and gross structure thing 52, and minimizing rehumidifies.As shown in Figure 9, one deck is sealed net and get up to form the ground floor 54 and the second layer 56 around works 52 foldings.The object of any routine of edge 58 usefulness of net 50, for example the binding agent edgewise seals pouch of (as shown in the figure) formation.Banding can be used ultrasonic seal, or heat/pressure is bonding.Net 50 can constitute with many kinds of materials, comprises non-woven design net, papery net, or the net of absorbing material such as napkin.Seal net 50 and preferably comprise a kind of net similar non-cloth shape net used with constituting top flat 38.Non-woven design net is preferably hydrophilic so that make the liquid can be promptly by sealing net 50.The lamellated absorption component of similar one-tenth (lamination) is at Timothy A.Kramer GeraldA.Young and Ronald W.Kock, and being entitled as on March 25th, 1986 in the United States Patent (USP) 4,578,068 of " absorbent layer stack structure " had explanation, can be for reference.

In addition, absorbent cores 42 of the present invention can be by single-piece or many s' porous of the present invention, and absorbefacient polymerization gross structure thing is formed, and can comprise the multilamellar conjugate of gross structure thing; Perhaps any other comprises the shape of one or more gross structure things of the present invention.

Figure 10 represents another embodiment of diaper 120, this diaper comprises a kind of double-deck absorbent cores 142, absorbent cores 142 be by one deck change shape hourglass shape absorbing component 60 and with its adjacent porous, (being that absorbing sheet 62 is between absorbing component 60 and egative film 40) that the absorbing sheet 62 of absorbability polymerization gross structure thing constitutes.

Absorbing component 60 is used for collecting fast and temporary transient Sheng body discharge liquor, and by the wick object liquid is transferred to absorbing component 60 from first contact point, and is transferred to gross structure thing absorbing sheet 62.Absorbing component 60 preferably includes the net or the cover plate of one deck fibrous material.Various fibrous materials all can be used for absorbing component 60, and for example the fibrous material of discussing with the front generally can adopt cellulose fibre, but suitable especially with wood pulp cellulose.Absorbing component 60 also can comprise a certain amount of granular, the absorbable polymer composition.Absorbing component 60 can comprise the component of polymer up to 50% by weight.In most preferred embodiment, absorbing component 60 contains the granular absorbing polymer composition of about 8% (wt) of 0-.In another preferred embodiment, absorbing component 60 comprises the chemical enhanced cellulose fibre that discussed the front.The exemplary embodiments of the used absorbing component 60 of the present invention is at Paul T.Weisman, DaWn I.Houghton and Dale A.Gellert are entitled as " with the absorbent article of double-deck core " United States Patent (USP) 4,673, in 402 (on June 16th, 1987), be entitled as " having the high density absorbing component that low-density and low basis weight are blocked the district " United States Patent (USP) 4 with Miguel Alemany and Charles J.Berg, in 834,735 (on Mays 30th, 1989) description was arranged, can be used as reference.Absorbing component 60 has the low section liquid zone of average main component weight ratio liquid storage area of liquid storage area and average density and unit are, makes that cutting a liquid zone can effectively and promptly intercept the liquid that gives off, and this is very important.

Absorbing component 60 can be any desired shape, for example: orthogonal, avette, ellipse garden shape, asymmetry or hourglass shape.The shape of absorbing component 60 can be consistent with total shape of formation diaper 120.In the embodiment shown in fig. 10, absorbing component is a hourglass shape.

Gross structure absorbing sheet 62 of the present invention need not have the size identical with absorbing component 60, and in fact, it may have the area more either large or small than the top surface area of absorbing component 60, as shown in figure 10, gross structure absorbing sheet 62 is littler than absorbing component 60, but the 0.10-1.0 topside area doubly that is about absorbing component 60 is arranged.The topside area of gross structure absorbing sheet 62 is that the 0.10-0.75 of absorbing component 60 topside areas is doubly better, and preferably 0.1-0.5 doubly.In another embodiment, absorbing component 60 is littler than gross structure absorbing sheet 62, and 0.25-1.0 topside area is doubly arranged.Better from the topside area of 0.3-0.95 gross structure absorbing sheet 62 doubly.In this embodiment, absorbing component 60 contains chemical enhanced cellulose fibre.

In diaper, preferably make gross structure absorbing sheet 62 and egative film 40 and/or absorption component 60 have fixed relative position relation.Especially, structure absorbing sheet 62 is always located towards the front of diaper, so that the position that makes structure absorbing sheet 62 be in the most effective section liquid and hold relief liquor.

In a further advantageous embodiment, multi-disc gross structure absorbing sheet, preferably 2-6 rectangular or sheet replaces the monolithic absorbing sheet 62 shown in Figure 10.And can be with additional absorbed layer, absorbing component, or other structural member is put into absorbent cores 142, for example: an additional absorption part can be placed between structure absorbing sheet 62 and the egative film 40, for absorbent cores 142 and/or one deck absorbing component provide storage liquid capacity, liquid is distributed to the other parts of absorbent cores 142 by absorbing sheet 62 or to structure absorbing sheet 62.Also the position change of structure absorbing sheet 62 is in above the absorbing component 60 it, and is positioned between top flat 38 and the absorbing component 60.

During use, by location, below, wearer back low back zone, the key position of holding diaper 20 places between the thigh of wearer, so that make the front positioning and fixing of Attacking Midfielder's zone through wearer with diaper 20.Paster shape securing member 46 preferably is fixed on the outer surface of diaper 20 then.During use, have porous of the present invention, absorbability, the diaper of polymerization gross structure thing or other absorbent article, because works has high imbibition ability, thus can distribute faster and effectively and store liquid, thus keep dry.

Synthetic urine

What adopt in the test method of the present invention is special-purpose synthetic urine, and synthetic urine is commonly referred to " Jayco Synurine " can be from Pennsylvania, and the Jayco pharmaceuticals company of CampHill obtains.The composition of synthetic urine is the KCl of 2.0 grams per liters; 2.0 the Na of grams per liter ₂SO ₄0.85 (the NH of grams per liter ₄) H ₂PO ₄0.15 (the NH of grams per liter ₄) ₂HPO ₄0.19 the CaCl of grams per liter ₂MgC1 with 0.23 grams per liter ₂All chemical substances all are the pure grades of reagent.The pH value of synthetic urine is within the 6.0-6.4 scope.

The absorbability of test method A. precursor particle

Polymer composition is placed within one " tea bag ", immerses certain hour in the excessive artificial urine, then through the centrifugal treating certain hour.Deduct recently definite absorbability of initial weight (clean liquid acquisition amount) and initial weight with the final weight of polymer composition after centrifugal treating.

Following step is carried out under the relative humidity standard conditions of 23 ℃ (73) and 50%.With the punch die of a 6cm * 12cm, cut out the material of tea bag, doubling along its length also forms the square tea bag of a 6cm * 6cm along the both sides sealing with T type sealing machine.Used tea bag material is 1234 grades of heat seal mateirals, can obtain from the C.H.Dexter branch of the Dexter company of U.S. Windsor LocksConnecticut, or uses materials similar.Adorn fine particle if desired, should use the tea bag material of low-porosity.The polymer synthetic that weighs up 0.200 ± 0.005 gram with pan paper is put into tea bag, seals the opening of tea bag then.The tea bag of a sky is lived as comparison along closedtop.Nearly 300 milliliters artificial urine is poured in one 1000 milliliters the beaker, empty tea bag is soaked in the artificial urine, tea bag (sample tea bag) horizontal of polymer synthetic will be included, material is evenly distributed in the whole tea bag, this tea bag is placed on artificial urine surface, make tea bag bubble wet, be no more than one minute approximately, immerse fully then and soaked 60 minutes.When first group of sample immerses about 2 minutes, will be blank by first group and second group of tea bag of the method preparation that the sample tea bag is same by first group same method immersion and soaked 60 minutes.To each group tea bag sample,, tea bag is taken out from synthetic urine rapidly after the time at above-mentioned dip with clip, then sample is made centrifugal treating by following process.Adopt in test Pittsburgh, the DeluxDynac II centrifugal device or the analog of the Fisher 05-100-26 type that the Fisher company of PA obtains.Centrifuge should be equipped with direct-reading tachometer and electronic brake.Centrifuge also is equipped with a garden cylindricality interpolation cylinder, it has nearly 2.5 inches (6.35 centimetres) height, the cylinder outer wall of external diameter 8.435 inches (21.425 centimetres), internal diameter is 7.935 inches (20.155 centimetres), around outer wall, there are 9 rows that the hole, garden of the equidistant layout of nearly 106 3/32 inch (0.238 centimetre) diameter is respectively arranged,, there is the garden shape osculum of 6 1/4 inch (0.635 centimetre) diameter at the end of cylinder, these holes are disposed at equal distance around edge, the end, and the distance at cylinder outer wall inner surface and osculum center is 1/2 inch (1.27 centimetres).Cylinder is fixed in the centrifuge, so that rotate and braking with centrifuge.The sample tea bag is fixed in the centrifugal basket, makes the folding end of tea bag be in centrifuge sense of rotation holding capacity.Blank tea bag is placed on the corresponding both sides of sample sack.Second group of sample tea bag must with first group of opposite placement of sample tea bag; And second group of blank tea bag need with first group blank tea bag is opposite places, with the equilibrium centrifugation machine.Centrifuge is started, and carry out the transition to the stabilized (steady-state) speed of 1500rpm rapidly, intervalometer is transferred to 3 minutes.After 3 minutes, centrifuge is turned off, and braking.The first sample tea bag and the first blank tea bag are taken out and weigh respectively.The second sample tea bag and the second blank tea bag are repeated above-mentioned steps.Absorbability (ac) to sample is calculated as follows:

Ac=(the blank tea bag weight after the sample tea bag weight after the centrifugal treating deducts processing deducts dried polymer composition weight again) is divided by (weight of the polymer composition of doing).Here, the value of absorbability is the average absorption ability of two samples.

B. liquid stabilising

The purpose of this method is to determine that granule is exposed to the stability on the synthetic urine.

Sample gross structure thing is put in the tray, excessive synthetic urine is added on this works, the expansion of observation structure thing is up to its balance.In the observation process, the works that can see granule splits from main, and scutellate granule is from main floating opening, or separates and floating from main with granule, only expands in the X-Y plane of bidimensional.If granule has a large amount of component particles of splitting, think that then the gross structure thing is unsettled.Also should expand and observe the isotropism of this works.If after test procedure, granule keeps relative stability, and keeps the relative geometry position and the spatial relationship of precursor particle and hole, can think that then this works is stable.Preferably, can not detect after their expand the gross structure thing of liquid stabilising and split partly.C. precursor particle size and quality average particle size particle size

Based on 10 particle size distribution that restrain the percetage by weight of overall precursor particle samples is that sample is with 19 size ranges by one, and it is definite that the bushing screen of No. 400 sieves (38 microns) carries out sub-sieve from No. 20 sieves of standard (850 microns) to standard.These standard screens can obtain from the Gilson company of ohio.Worthington.Because device therefor can not once hold 19 sieves, so the triple-lap sieve is once carrying out in this step, first stacked package draws together 20 ^#, 25 ^#, 30 ^#, 35 ^#, 40 ^#, 45 ^#, and 50 ^#Sieve adds screen tray; Second stacked package draws together 60 ^#, 70 ^#, 80 ^#, 100 ^#120 ^#With 140 ^#Sieve adds screen tray; Triple-lap comprises 170 ^#, 200 ^#, 230 ^#, 270 ^#, 325 ^#With 400 ^#Sieve adds screen tray.Then, the precursor particle of staying in each sieve is weighed to determine the particle size distribution of percent by weight.

The first folded sieve is installed on the vibrator, and the sample of 10.0 gram plus-minuss, 0.00 gram is placed on 20 ^#On the sieve.The vibrator of selecting for use is the vibrator of 3 inches sieves of vibration of Model-SS-5 type, can be from ohio, and the Gilson company of Worthington obtains.To be similar to 2100 vibrations of per minute 3 minutes, (on the instrument calibration dish " 6 ") removed screen tray then with bushing screen, and should the placement of cover group weigh so that wait a moment on one side.To stay on sample collection to a ground paper on the screen tray with a soft brush.Second bushing screen is installed on the vibrating grid, and the sample on the ground paper is put into 60 ^#On the sieve, under 2100 vibrations of per minute,, the sample collection on the screen tray to ground paper, should be folded sieve and set aside the second folded sieve vibration 3 minutes.Again the triple-lap sieve is installed on the vibrating grid, and the sample on the ground paper is put into 170 ^#In the sieve, to triple-lap sieve vibration 3 minutes, the sample in soft brush each being sieved was delivered on the ground paper through weighing under nearly 2100 vibrations of per minute.Weigh up the weight of sample with three balances of standard, and the example weight of each sieve is noted.After triple-lap sieve was all vibrated, each sieve and the sample stayed on the screen tray are repeated above-mentioned weighing step.Sample with two other 10 grams repeats the method.Determine to be of a size of the percetage by weight that basic average particle size distributes with the average of three example weights with each sieve to every kind of sieve.The quality average particle size particle size of the overall sample of 10 grams is calculated as follows:

maps = \frac{Σ (Di \times Mi)}{ΣMi}

Wherein, maps represents the quality average particle size particle size; Particulate weight on the sieve that Mi represents to determine; Di represents the " dimensional parameters for the sieve of determining." the dimensional parameters Di of a sieve is defined as the size (micron) of more higher leveled sieve.For example: a standard 50 ^#Sieve has 355 microns dimensional parameters, 45 of it and standard ^#The mesh size unanimity of sieve (higher one-level).The quality average particle size particle size here is the meansigma methods of three sample quality average particle size particle size.

Precursor particle embodiment

10 liters of both arms rustless steels of a double-cylinder type are rubbed gentle machine with the hands the degree of depth of opening and the 240mm of 220mm * 240mm, and has two (∑s) (Sigma) rotation diameter 120mm fin of type, covers with a cap seal.Prepare a kind of water-containing monomer solution that is made of the monomer of 37% weight, monomer is made up of 75% molar sodium acrylate and 25% molar acrylic acid.Become monomer solution put into to rub with the hands in the cylinder of gentle machine in the water of 5500 grams, this cylinder with nitrogen purge to dispose the air that retains.Then, two ∑ type fins are adjusted to the speed of 46rpm rotate, the cover cylinder then heats with 35 ℃ water channel.Adding the sodium peroxydisulfate of 2.8 grams and the L-ascorbic acid of 0.14 gram is polymerization initiator.After initiator added about 4 minutes, polymerization began.After adding initiator 15 minutes greatly, response system inside reach and 82 spend (℃) maximum temperature.Under not stopping to stir continuously, the hydrogel aggregation is formed the granule of 5mm size.Began back 60 minutes in polymerization, lid is removed from rubbing gentle machine with the hands, and will be taken out in the material slave.

Become aquogel polymer to be layered on 50 in the water of gained ^#On the wire netting of size, with 150 ℃ hot-air dries 90 minutes, with a capitate destroyer with the drying particulate fragmentation, and with standard 20 ^#Sieve (850 microns) sieves, and obtains by 20 ^#The granule of sieve.These particulate quality average particle sizes are 405 microns.

Embodiment 1

To put in the kitchen type agitator of 5 quarts of standards by precursor particle 350.0 grams that front precursor particle embodiment makes, the particle size that the precursor particle is had can make it pass through 60 of standard ^#Sieve (250 microns) and stay 100 of standard ^#On the sieve (150 microns).Each restrains glycerol (glycerol) by 7.0 system, the solution of 35.0 gram methanol and 7.0 gram water.(Yonkers, the common sprayer that NY) provides is sprayed on solution above the precursor particle, so that the precursor particle is coated this solution with a Precision Valve company.One side is being driven agitator, and one side is sprayed onto solution on the precursor particle.In initial 15 seconds of spraying, agitator is transferred in minimum running speed, and after 15 seconds, agitator at full throttle turns round.The whole range request that sprayed was sprayed onto whole solution capacity on the precursor particle with 3 minutes.Reuse agitator is at full throttle stirred the mixture so that all precursor particles to be entirely solution drenched.Then, formed compound is put in the hopper of foregoing extruder/compactor.The propeller of extruder has 8 inches (20.3 centimetres) long, and 5 rubbing boards are arranged, and each 1.5 inches (3.8 centimetres) are long.1.75 inches of the external diameters of extruder propeller (4.45 centimetres), the gap of propeller and cylinder cover are 0.20 inch (0.51 centimetre).Start this device, make the speed running of propeller with 47rpm.Mixture is squeezed between the compacting roll with fixing (but can change) gap.The pressure roller diameter is 8.975 inches (22.8 centimetres), and is driven with 5.4rpm speed.Gap between the pressure roller be 0.015 inch (0.38mm) then, formed lamellar aggregation is divided into the long section of approximate 12-15 inch (30-40 centimetre), with the aggregation sheet that forms with heating in the baker of 210 ℃ air blast convection current 45 minutes, so that the polymer of precursor particle and glycerol (glycerol) react.Its thickness of final sheet (using kind of calliper) is 0.031 inch (0.8 millimeter) and about 1.95 inches of width (4.95 centimetres).

Embodiment 2

Preparation contains 0.5 gram glycerol, and 0.5 gram water and 3.0 restrains the solution of isopropyl alcohols, this solution is added to by the front prepare on the 25 gram precursor particles of being produced among the embodiment of precursor particle.The particle size that the precursor particle has makes that it can be by 40 of standard ^#Sieve (425 microns) and partly stay 50 of standard ^#In the sieve (300 microns).Compound mixes fully with an agitator scraping blade, makes all precursor particles all coat above-mentioned solution.Mixture is divided into approximately uniform a few part, half of mixture is layered on the SUPERSTONE baking potlery tile sheet equably, this potlery tile sheet can have been bought from the Sassafras Enterprises company of ILEvanston.Mixture is pressed on the potlery tile sheet gently, 0.16 gram KODEL polyester fiber is dispersed on the formed mixture equably.It is 1.25 inches (3.2 centimetres) that this polyester fiber is cut into length, harden, 15.0

Fiber.Be layered on above the fiber equably half part in addition of this mixture and compacting a little.Then, with the total thing with the rod roll extrusion of wooden garden into about 0.06 inch (1.5 millimeters) thickness.On the thin slice of roll extrusion, put a slice MYLAR (mylar) in order to avoid mixture adheres on the nip roll.Then, with this thin slice doubling and repeat rolling.This doubling/roll extrusion (gentle rub with the hands) step will carry out twice, afterwards this thin slice is placed on that 200 ℃ of heating reach 45 minutes in the baking oven of circulation air blast, makes the polymeric material reaction of glycerol and precursor particle.The thickness of the gross structure thing of Sheng Chenging (using the slide calliper rule amount) is about 0.6 inch (1.5 millimeters) at last.

Embodiment 3

Preparation restrains glycerol by 1.6, and the solution that 3.2 gram water and 12.8 gram isopropyl alcohols are formed is added to solution on the 80 gram precursor particles of making by top precursor particle embodiment, and the granular size distribution of sizes that this precursor particle is had is that 8% of its weight passes through 20 ^#Sieve (850 microns), and it remains in 30 ^#On the standard screen (600 microns); 15% of its weight passes through 30 ^#(600 microns) standard screen, and it remains in 40 ^#On (425 microns) sieve; 22% of its weight passes through 40 ^#The standard screen of (4.25 microns), and it remains in 50 ^#On (300 microns) sieve; 36% of its weight passes through 50 ^#The standard screen of (300 microns), and 19% (weight) is by 100 ^#(150 microns) standard screen.Above-mentioned substance is coated above-mentioned solution with a poking bar stirring up to all precursor particles.Formed mixture pine loose ground is layered on the potlery tile sheet of a SUPERSTONE baking usefulness.And be rolled into the thin slice of (1.5 millimeters) thickness that has 0.06 inch with waddy.Adhere on the rod to prevent mixture being subjected to put a slice MYLAR (mylar) on the thin slice of roll extrusion.Then, thin slice is placed high wind circulation baking oven, with 200 ℃ of heating 45 minutes, make the polymeric material effect of glycerol and precursor particle, the thickness of resulting gross structure thing (using the slide calliper rule amount) is about 0.06 inch (1.5 millimeters).

Embodiment 4

Prepare a kind of by 0.342 gram glycerol, the solution that 0.136 gram water and 1.713 gram methanol are formed.In addition, get the precursor mix particles of a certain sizes of the FIBERSORB fiber that can buy from ArCO company of 0.512 gram and 13.364 grams, the granule of this precursor particle all passes through standard 100 ^#Sieve (150 microns) is produced according to aforementioned embodiment, forms the precursor particles mixture through mixing.Above-mentioned fiber can be cut into the length between about 0.5 inch (1.25 centimetres) to 2.5 inches (6.35 centimetres).Above-mentioned solution is added on the precursor particle, and stirs, to form a kind of accumulative mixture with poking bar.Formed aggregate mixture is spread on the PYREX heat resistant glass culture dish of 6 inches (15 centimetres), and be compacted to about 0.15 inch (3.8 millimeters) thickness with little scraper.Then, this sheet is placed 200 ℃ of heating of powerful air circulation baking oven 40 minutes, glycerol and precursor particulate polymer (FFIBERSORB and two kinds of polymer of precursor particle of being produced by precursor particle embodiment) are reacted.The gross structure thing that is generated has by quite little irregularly shaped particles, and the synthetic nutty structure of fiber that gets up with this granule intermingling.

Embodiment 5

Preparation is by 0.023 gram glycerol, and 0.014 gram water and 0.580 restrains the solution that methanol is formed.This solution is joined 0.880 gram can be from the fibrous precursor particle of the FIBERSORB that ArCO company has bought, and this fiber is cut into the have 0.5 inch length range of (1.25 centimetres) to 2.5 inches (6.35 centimetres).Solution and precursor particle are stirred with poking bar, it is mixed fully form a kind of aggregate mixture.With formed granule polymer dispersed on the PYREX heat resistant glass culture dish of 6 inches (15 centimetres), and be compacted into the thin slice that thickness is 0.007 inch (0.178 millimeter) with little scraper, then, this thin slice is placed strong air circulation oven, 200 ℃ of heating 30 minutes, so that the reaction of the polymeric material of glycerol and precursor particle.Formed gross structure thing contains the poly-fine crosslinked aggregation in inside of a kind of and non-woven design net analog structure.

After embodiments of the invention being made description and explanation, clearly, for those those skilled in the art, may make various change and the restrictions that do not deviate from the present invention's spirit and scope, to this, variation within the scope of the present invention that all are such and restriction are all in the dependent claims topped.

Claims

1. absorbing products that comprises substrate and the porous that makes as follows, absorbability, polymeric gross structure thing, described works with comprise have by the crosslinked granule of the intergranular of the interconnection hole of the passage that is interconnecting so that this works be fluid permeable be feature; Said method comprising the steps of:

(a) provide that a large amount of water in fact can not be molten, absorbefacient, form precursor particle hydrogel, polymeric material;

(b) the intergranular cross-linking agent is added on the described precursor particle, described intergranular cross-linking agent is to react with the polymeric material of described precursor particle;

(c) make combine on the described precursor particle physics with form a kind of have by the interconnective hole of passage that is interconnected the granule;

(d) keeping under the bonded situation of described precursor particle physics, making the polymeric material reaction of the precursor particle of described intergranular cross-linking agent and described granule, forming crosslinked gross structure thing of a kind of intergranular to form the cross-bond between the described precursor particle.

2. by the absorbing products of claim 1, wherein said method also comprises the surface-crosslinked step of gross structure thing.

3. by the absorbing products of claim 1, wherein said method also comprises before that in step (d) diplomatic corps's particle shape becomes the forming step of suitable shape, size and/or density.

4. by the absorbing products of claim 1, the step of wherein said method (d) comprises heating.

5. by the absorbing products of claim 1, wherein said method also comprises adds reinforcing fibre in the precursor particle step.

6. by the absorbing products of claim 1, wherein said intergranular cross-linking agent comprises the monomer of the energy polymerization formation interparticle polymerization crosslinking key of described precursor.

7. by the absorbing products of claim 6, the step of wherein said method (d) comprises carries out irradiation and the step of polymerization reaction to described monomer.

8. by the absorbing products of claim 1, wherein said precursor particle has the quality average particle size less than about 500 microns.

9. by the absorbing products of claim 1, wherein said precursor particle has the quality average particle size less than about 300 microns.

10. by the absorbing products of claim 1, wherein said precursor particle comprises fiber.

11. an absorbing products, it comprises the permeable top flat of liquid; The liquid-tight egative film that connects together with described top flat; And being in absorbent cores between described top flat and the egative film, wherein said absorbent cores comprises the gross structure thing described in the claim 1.

12. by the absorbing products of claim 11, wherein said absorbent cores also comprises the big envelope net of packing described gross structure thing.

13. by the absorbing products of claim 12, wherein said big envelope net comprises a kind of net of non-weaving cloth of the hydrophilic staple fibre along its periphery sealing.

14. by the absorbing products of claim 11, wherein said absorbent cores also comprises the absorption component that is between described top flat and the described works.

15. by the absorbing products of claim 11, wherein said gross structure thing also comprises the reinforcing fibre that is embedded in this works.

16. an absorbing products that comprises substrate and the porous that makes as follows, absorbability, polymeric gross structure thing, described works with comprise have by the crosslinked granule of the intergranular of the interconnection hole of the passage that is interconnecting so that this works be fluid permeable be feature; Said method comprising the steps of:

(a) provide a large amount of insoluble in water in fact, absorbefacient, form precursor particle hydrogel, polymeric material, that do, the polymeric material of described precursor particle is selected from the starch-acrylonitrile graft copolymer through hydrolysis; Neutral starch-the acrylonitrile graft copolymer of part; Starch-acrylate graft copolymer; The neutral starch-acrylate graft copolymer of part; Saponified vinyl acetate-acrylate copolymer; The acrylonitrile of hydrolysis or acrylamide copolymer; The product that slight network cross-linked is arranged of above-mentioned any copolymer; The neutral polyacrylic acid of part; Or the neutral polyacrylic product that slight network cross-linked is arranged of part;

(b) the intergranular cross-linking agent is added on the described precursor particle, described intergranular cross-linking agent is selected from polyol compound, poly epihydric alcohol ether compound, polyfunctional aziridines chemical compound, multi-functional amine compounds and polyfunctional isocyanate's chemical compound;

(c) make on the described precursor particle physics in conjunction with to form a kind of granule with the hole that couples together by the passage that interconnects;

(d) diplomatic corps's particle shape becomes desired shape, size and/or density;

(e) under bonded situation on the maintenance precursor particle physics, to described intergranular cross-linking agent and described heating, so that the described polymeric material reaction of described intergranular cross-linking agent and described granule precursor particle, form the cross-bond between the described precursor particle and form the gross structure thing of crosslinked of intergranular.

17. by the absorbing products of claim 16, wherein said method also is included in before the polymeric material reaction that makes described intergranular cross-linking agent and precursor particle, adds fiber in the described precursor particle step.

18. by the absorbing products of claim 16, wherein said method also comprises the step that makes works surface-crosslinked.

19. by the absorbing products of claim 16, wherein said precursor particle comprises fiber.

20. by the absorbing products of claim 16, wherein said intergranular cross-linking agent is to mix with water, organic solvent or their mixture.

21. by the absorbing products of claim 20, the step of wherein said method (d) comprises the molding granule.

22. by the absorbing products of claim 20, the step of wherein said method (d) comprises makes a shaping.

23. by the absorbing products of claim 22, the step of wherein said method (d) comprises extrudes described, and follows the roll extrusion granule to form thin slice.

24. absorbing products by claim 16, wherein said intergranular cross-linking agent is from trimethylolpropane, ethylene glycol, 1,2-propylene glycol, 1, select in the thing group that ammediol or glycerol are formed, and described polymeric material is made up of the neutral polyacrylic product by slight network cross-linked of part basically.

25. by the absorbing products of claim 24, the step of wherein said method (e) is carried out the time between 3 hours and 30 minutes in 170-220 ℃ of temperature range.

26. by the absorbing products of claim 25, wherein said intergranular cross-linking agent is to mix with water, organic solvent or their mixture.

27. by the absorbing products of claim 26, the step of wherein said method (d) comprises extrudes granule, then granule is carried out roll extrusion and makes step in blocks.

28. by the absorbing products of claim 27, the step of wherein said method (b) comprises described intergranular cross-linking agent is sprayed on the described precursor particle.

29. by the absorbing products of claim 27, the quality average particle size particle size of wherein said precursor particle is less than about 300 microns.

30. by the absorbing products of claim 29, wherein about at least 95% described precursor particle by weight has the size between the 150-300 micron.

31. by the absorbing products of claim 27, the quality average particle size particle size of wherein said precursor particle is less than about 180 microns; And about 95% precursor particle at least by weight has the particle size between 90 microns to 180 microns.

32. by claim 24,29,30 or 31 absorbing products, wherein said method also comprises the crosslinked step of precursor particle surface that makes described works of carrying out simultaneously with step (e).

33. by claim 19,24,26 or 29 absorbing products, wherein said method also is included in before the polymeric material that makes described precursor particle and the reaction of described intergranular cross-linking agent the step of reinforcing fibre being added in the described precursor particle.