JPS60104503A - Absorbing structure comprising plant absorbing material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to novel absorbent structures comprising absorbent materials of plant origin.

Disposable absorbent products (eg, disposable diapers, sanitary napkins, etc.) generally contain an absorbent web of wood pulp fibers. Depending on the climate, it takes about 20 to 40 years for a tree to grow to a state where it can be harvested. Therefore, in order to meet the demand for wood pulp fibers for use in absorbent materials, large areas of land are required for growing trees. As another result, even though wood pulp fibers are perhaps the most economical material for disposable absorbent products available today, substantial expenditures are made on harvesting and growing trees. Therefore, there is a continuing need for alternative inexpensive absorbent materials, preferably from renewable sources.

It has now been discovered that a variety of pectin-containing agricultural by-products can be converted into superabsorbent materials suitable for use in disposable absorbent products by a relatively simple and inexpensive process. Typical examples of agricultural by-products suitable as raw materials for the absorbent materials of the present invention are residues from citrus juice processors and sugar beet refineries. Therefore, these materials are available in abundance at low cost.

Agricultural by-products are preferably converted to absorbent materials by methods involving deesterification of pectin methyl esters in the materials, removal of water-soluble organic substances (eg, carbohydrates), or both. Preferred plant-derived materials are prepared by a process that involves hydrolyzing or partially hydrolyzing the pectin methyl esters present in the waste, followed by washing and drying the material. The absorbency of the materials can be further improved by subjecting them to a bleaching process. Such a bleaching process also improves the appearance of the product, thereby making it more acceptable for use in disposable absorbent products. Plant-derived absorbent materials typically have an absorbent capacity that is 2 to 5 times the absorbent capacity of normal wood pulp fiber webs. These materials therefore offer an opportunity to reduce the bulk of absorbent products while maintaining their carrying capacity.

Therefore, the object of the present invention is that, in addition to the usual absorbent materials,
An object of the present invention is to provide an absorbent structure comprising a novel absorbent material of plant origin. Yet another object of the invention is to provide disposable absorbent products, such as disposable diapers and sanitary napkins, comprising the absorbent structure of the invention.

BACKGROUND OF THE INVENTION Agricultural waste suitable as starting material for the manufacture of the absorbent materials of the invention is produced in large quantities. skin (i.e., albedo and flaved).

)] and rags are commonly processed into cattle feed by a process referred to as "lime dehydration". This method involves treating the waste with "lime" (calcium oxide, calcium hydroxide, or even calcium carbonate) to create a mud-like structure.
7I consists of converting from an incompressible state to a water-like compressible state, pressing the converted waste, and drying (e.g., U.S. Pat. No. 2,147,521, U.S. Pat. .215.944 and US Pat. No. 2,362j014).

Relatively small amounts of citrus waste are used as a source of pectin and can be used as thickeners in foods. Food thickeners may also be prepared by grinding citrus peel material and reducing the degree of esterification of the citrus pectin material by enzymatic or chemical treatment. This approach is disclosed in US Pat. No. 3,982,003 and US Pat. No. 4,143,172. Another attempt to convert citrus waste into food additives for human consumption is disclosed in US Pat. No. 4,225,628. According to the method described in this document, citrus peel particles are dehydrated by a method very similar to the lime dehydration method used in cattle feed production. after that,
the substance is mixed with sesame grain flour and ground;
Dry and mill to desired particle size. US Pat. No. 4,379,782 discloses the use of citrus albedo or sugar beet pulp as dietary fiber. The material is extracted with water or isopropanol to remove soluble carbohydrates and color and flavor substances. Despite these attempts to find more advantageous uses for citrus waste, almost all of the citrus waste from juice canneries is
It is still being converted into cattle feed and sold at prices that provide little recovery of processing costs.

Like citrus residues, sugar beet residues (commonly referred to as sugar beet pulp) are commonly converted into cattle feed. As in the case of citrus residues, attempts have been reported to convert sugar beet pulp into food additives suitable for human consumption. An example is JP-A-57-54573. This patent discloses upgrading sugar beet pulp by bleaching the pulp in hypochlorous acid at pH 6.5-7.5, washing with water, and drying.

The material is reported to be able to absorb approximately 90% of its capacity as water.

SUMMARY OF THE INVENTION The present invention provides: (1) by weight of plant-derived absorbent material;
(1) about 15% of a substance selected from the group consisting of: (1) cellulose, hemicellulose, lignin, and mixtures thereof; ~about 80%, (0
) a chloroform-soluble lipid of 0 to about 4 parts, and (d)
An absorbent material of plant origin consisting of θ% to about 35% of non-lipid organic matter extractable in a mixture of chloroform, methanol and water, said mixture having a volume ratio of chloroform to methanol to water of 20+4:1. 1% to about 99%
and (2) absorbent structures comprised of about 1% to about 99% conventional absorbent materials.

The invention further relates to disposable absorbent articles, such as diapers or napkins, comprising the absorbent structure of the invention. Such absorbent products typically include (a liquid-impermeable backing sheet, (11) a hydrophobic topsheet, and (C) an absorbent structure according to the invention, said structure comprising:
(placed between the backing sheet and the top sheet).

3. Detailed Description of the Invention The present invention relates to a novel absorbent structure made of a novel plant-absorbable material and an absorbent product comprising the absorbent structure.

The present invention is based on the discovery that pectin-containing plant materials can be converted into absorbable materials using relatively simple and inexpensive methods. Pectin-containing plant materials which are suitable as starting materials for the production of the absorbent materials of the present invention are low in pectin (all containing about 15%; examples are apple, hong apricot, citrus peel, sugar beet and watermelon peel). be.

For example, zucchini with a pectin content of about 8% is not suitable. Citrus peels and sugar beet pulp, each of which are important agricultural by-products, are available in large quantities at low cost and are preferred starting materials for the manufacture of the absorbent materials of the present invention.

The compositional parameters of the plant starting material and of the plant absorbable material obtained during processing have been determined in the comprehensive analytical protocol given below.

The components of the materials used herein are equivalent to the total amount of polygalacturonic acid.
The weight ratios are as measured by this analytical protocol, except for the "divalent metal equivalent weights" and the "degree of esterification" which are centages). However, data obtained by different analytical methods may differ, which precludes direct comparisons with such data. In particular, the indirectly measured pectin content, cellulose content and hemicellulose content and degree of esterification are parameters that are sensitive to the analytical method used.

In the analytical protocol, the water content of a sample of the material to be analyzed is determined by Karl Fischer titration. The amounts of calcium, magnesium, sodium and potassium are determined by flame atomic absorption spectrometry of these metals after dry ashing. A third sample of material is subjected to water extraction followed by Soxhlet extraction with chloroform for 40 hours. The amount of lipids in the extract is measured by weight (hereinafter referred to as “chloroform-soluble lipids”).
). If the material to be analyzed does not contain components that are both water-soluble and chloroform-soluble,
Water extraction before chloroform extraction can be omitted. Thus, the chloroform extract of the absorbent material derived from citrus peel does not contain water-soluble components, but the absorbent material derived from sugar beet is found to contain water-soluble components in the chloroform extract. It's being served. Therefore, materials derived from citrus peels can be extracted with chloroform without prior water extraction;
An accurate reading of the amount of chloroform soluble lipid is then obtained. On the other hand, sugar beet derived material must be extracted with water before chloroform extraction to obtain accurate measurements of the amount of chloroform soluble lipids.

The fourth sample is extracted with chloroform and then subjected to Soxhlet extraction with chloroform/methanol/water (20/4/1, V/V/V) for 40 hours (the measurement of chloroform-soluble lipids was If done without water extraction, the residue of the test can be used for this chloroform/methanol/water extraction). The amount of extracted material measured by weight is the sum of the amount of water-soluble metal salts and non-lipid organic matter.

Metal cations are measured by flame ionization. The amount of water-soluble metal salt (hereinafter referred to as "water-soluble metal salt") can be varied widely (the molecular weight of the anion used (known from the processing history of the sample; in the case of chlorine bleaching, For example, the amount of non-lipid organic matter (a widely used anion is chloride) is used and then calculated.
The amount of water-soluble metal salts (hereinafter referred to as "non-lipid organic substances") is determined by subtracting the amount of water-soluble metal salts from the total amount of material extracted with the chloroform/methanol/water mixture.

The residue of the chloroform/methanol/water extraction contains cellulose, hemicellulose, lignin, pectin and pectates. The residue is divided into four parts. The first portion is subjected to acid hydrolysis of cellulose and hemicellulose, followed by GC analysis of aldononitrile peracetate derivatives of sugars. A third portion of the residue is analyzed for protein. Protein content is calculated from nitrogen values determined colorimetrically using Nessler's reagent. The third part of the residue was gravimetrically determined by TAPPT.
Analyzed for lignin using T222-os-74. The fourth portion of the residue is analyzed for calcium, magnesium, sodium and potassium by dry ashing and then flame atomic absorption spectroscopy of the metals. The amount of pectin is calculated from the total amount of bound metals (ie metals that cannot be removed by chloroform extraction or chloroform/methanol/water extraction) and methoxy content. From 1 to 41% of the amount of bound calcium and magnesium and pectin in the sample
is calculated as the equivalent coefficient of polygalacturonic acid present as a divalent metal salt. Similarly, the degree of esterification is calculated from the methoxy content and the total amount of pectin in the sample as a function of the equivalents of polygalacturonic acid present as methyl ester.

The analysis protocol is illustrated by the flowchart in FIG. The water content 1 is determined by Karl Huitsunyer titration method. The methoxy content 2 is determined by GO analysis of the free methanol after base hydrolysis. Total metals 3 are measured by flame atomic absorption spectrometry of the metals after dry ashing. Lipid 4 is determined gravimetrically after 40 hours of Soxhlet extraction with chloroform. The residue of the chloroform extraction was then diluted with chloroform/methanol/water (20/4/1, V
/V/Tl) for 40 hours and the other extractable substances 5 are weighed. lignin 6
is determined gravimetrically using the TAPP method T 222-os-74. Protein 7 is calculated from nitrogen values measured colorimetrically using Nessler's reagent. Cellulose and hemicellulose 8 are measured by GO analysis of aldononitrile peracetate derivatives of sugars after acid hydrolysis. Bonding metal 12
is determined by flame atomic absorption spectrometry of the metal after dry ashing. Pectin 9 contains methoxy [
2 and the combined metal 12. From bound calcium 12 and pectin 9, calcium equivalent 111
is calculated. From methoxy-containing jt2 and pectin 9, the degree of esterification is calculated as 10ij, assuming that the polygalacturonic acid present as methyl ester is 1%.

"Pectin" as measured by this method is a substance in a composition that can form methyl esters or bind metals calculated as polygalacturonic acids. The implicit assumptions are that the pectin does not contain any free radicals, that all veritin is galacturonic anhydride, and that there are no insoluble alkaline earth metal salts other than calcium salts. These assumptions have been proven correct within reasonable confidence limits by independent methods.

The sum of cellulose and hemicellulose is taken to be the sum of the neutral sugars remaining in the sample after extraction with chloroform and extraction with a chloroform/methanol/water mixture.

Cellulose can be measured separately as the total amount of glucose. The remainder of the neutral sugars are hemicellulose.

It has been discovered that pectin in the composition plays a critical role in determining the absorbency of the material.

Although the composition varies between and within species, more than 60% of the pectin in plant material is generally present in the form of methyl esters. In the case of orange peel, about 20% is present as calcium salt. The remainder is generally in protonated form or an alkali metal salt, usually a potassium salt. Preferred plant-derived absorbent materials for use in the absorbent structures of the present invention are those in which the pectin has a degree of esterification of less than 45%, more preferably less than 20%.

In order to obtain a degree of esterification of less than 45%, the vegetable starting material must be subjected to a deesterification step.

The deesterification step can be carried out by alkaline treatment at a pH of about 8 to about 13 or by enzymes such as pectin esterases. The enzyme is naturally present in the peel of citrus fruits. Care should be taken that the amount of divalent metal pectate is not increased substantially. In particular, calcium pectate has been found to be detrimental to the absorbability of the material. Furthermore, once formed, calcium pectate cannot be easily converted to other pectic substances, such as alkali metal salts or pectic acid. Generally, the total equivalent weight factor of divalent metals should be less than 50 inches. The i% of calcium is preferably less than 3056. As a practical matter, this means that calcium hydroxide or calcium carbonate cannot be used for alkaline deesterification. However, it is not necessary to use distilled or deionized water. Water hardness is approximately 7 grains/
It has been found that tap water does not significantly reduce the absorbency of the material, provided that no more than a gallon (equivalent to about 120 ppm Oa00B) and excess water is used.

Therefore, as used herein, the term "soft water" refers to hardness less than 7 grains/gay (less than about 120y Oa00g).
means water with

Particularly when citrus waste is used, the plant starting material can contain a complex mixture of lipids and lipid-like substances and other non-polymeric organic substances.

The absorbency of the resulting absorbent material can be significantly increased by removing these organic extractable substances. Organic extractable substances generally include two types of substances: the first type of substances are soluble in chloroform and are mostly identified as non-polar lipids (these substances are referred to herein as "chloroform-soluble lipids"); It is not soluble in chloroform alone, but a mixture of chloroform, methanol and water [Chloroform vs. methanol vs. water - 20! 4 s t (v/v/v
) It has been discovered that it belongs to one of the second class of substances that dissolve in ). This second class of substances consists of non-lipid organic substances and water-soluble metal salts.

For use in the absorbent structures of the present invention, the plant-derived absorbent material should contain no more than about 4%, and preferably less than about 1%, chloroform-soluble lipids. In addition, plant-derived absorbent materials are more abundant than approximately 35% of non-lipid organic substances that can be extracted into the mixture of chloroform, methanol and water (chloroform to methanol to water - 2Ot4s1 (v/v/v)). Preferably, the plant-based absorbent material contains less than 10% of such non-lipid organic matter. The plant-based absorbent material contains about 6% of water-soluble metal salts. It is also preferable to contain less than 1.

Accordingly, the present invention provides (1) about 15% to about 60% pectin (5% of pectin) by weight of the plant-derived absorbent material;
(1) from about 15% to about 80% of a material selected from the group consisting of: (1)) mixtures of cellulose, hemicellulose, lignin, and solella;
(Cl chloroform soluble lipids o1 to about 4 parts, (dl non-lipid organic matter extractable in a mixture of chloroform, methanol and water Oqb to about 35 parts, said mixture having a volume ratio of chloroform to methanol to water of 201411) About 1 to about 991 plant-derived absorbent materials consisting of
1b and (2) relate to absorbent structures comprised from about 1% to about 99% of conventional absorbent materials.

Although the degree of esterification of pectin does not seem to have a major effect on the final absorbent capacity of the absorbent material, a low degree of esterification may result in a better wicking property of the material.
A high wick rate of action is important for rapid uptake of liquid. For use in absorbent products such as disposable diapers, sanitary napkins, etc.
Good wicking properties of absorbent materials are highly desirable. Therefore, the absorbent material preferably has a degree of esterification of about 45
pectin, more preferably less than about 20%.

The second major component of plant-based absorbent materials after pectin is generally a mixture of cellulose, hemicellulose and lignin. The actual composition of this mixture is mostly
It is determined by the choice of raw materials and to some extent by the method. For example, hemicellulose appears to be partially removed during processing. This increases the relative amounts of cellulose and lignin in the mixture. Depending on the raw material source, the amount of lignin can vary slightly. For example, citrus waste has significantly less lignin than sugar beet pulp. Still very good absorbent materials can be prepared from either starting material.

Divalent metal pectates, especially calcium pectate,
It has been found to be much inferior to alkali metal pectates (eg, sodium pectate) in terms of absorption. This is probably due to the fact that divalent metal salts of pectin are "cross-linked", whereby the divalent metal ion serves as a link between two adjacent pectin molecules.

This crosslinking is believed to prevent pectin from swelling, thereby reducing its absorption capacity. Some pectin exists naturally as a calcium salt. Care must be taken not to further increase the amount of calcium pectate. Therefore, during processing, the material should not be exposed to excessive amounts of calcium. The presence of calcium is probably not harmful if it is present in the form of an insoluble mineral salt that cannot interact with the esterified pectin.

One particular embodiment of the invention provides (1) about 60 pectins by weight of the absorbent material derived from citrus peels.
(the pectin has a degree of esterification of less than about 20% and less than about 30 φ of the pectin is in the form of calcium salts), (a mixture of 1:11 cellulose and hemicellulose (J % to about 6 (1, (01) Chloroform soluble lipid θ% to about 1%, ((1) 0 to about 10% of non-lipid organic matter extractable in a mixture of chloroform, methanol and water (the mixture contains chloroform vs. methanol vs. a citrus peel-derived absorbent material comprising from about 1 part to about 99 parts, (e) from about 1 part to about 99 parts water-soluble metal salts, and (2) from about 99 parts to about 99 parts; and (2) a conventional absorbent material. It is an absorbent structure consisting of about 1 inch to about 99 inches.

A second specific embodiment of the invention provides (1) less than about 45% pectin by weight of the sugar beet-derived material; ) and less than about 100% of pectin
(1)) a mixture of cellulose and hemicellulose from about 2096% to about 80%; (C) in the form of a calcium salt;
(d) 0 to about 10% of non-lipid organic matter extractable in a mixture of chloroform, methanol and water, said mixture having a volume ratio of chloroform to methanol to water of 21411; ), (
e) an absorbent structure consisting of about 1 to about 99 parts of a sugar beet-derived absorbent material consisting of 6 to about 6 Oq of a water-soluble metal salt, and (2) about 1 part to about 99 parts of a normal absorbent material. be.

Methods for producing absorbent materials of plant origin The methods required to produce absorbent materials of plant origin from pectin-containing starting materials depend to a large extent on the starting material to be used. The purpose is to remove excess extractable substances and preferably also to reduce the degree of esterification of the pectin of the material.

For example, plant-based absorbent materials are described in U.S. Patent No. 3.98
It can be obtained from citrus peel using the method described in US Pat. No. 2,003. The method described in this document yields a plant-based absorbent material of acceptable quality, especially when the fried material is removed from the orange peel before processing, as described in Example 7 thereof.

However, the method described in said US Pat. No. 3,982,003 does not include a bleaching or washing step. Therefore, the product obtained by the method of this patent is
They do not contain relatively large amounts of chloroform-soluble lipids and tend to be relatively dark in color.

Acceptable plant-based absorbent materials are described in U.S. Patent No. 4.3.
It is also obtained from citrus peel or sugar beet pulp using the method described in US Pat. No. 79,782.

The method described in this document yields absorbent materials of acceptable quality, especially when sugar beet pulp is used as starting material. However, the said U.S. Patent g 4.379
．． The method described in '782 does not involve deesterification. As a result, the material has relatively poor wicking properties.

(a) Pectin-containing plant material with a particle size of approximately 0.05 mm ~
(b) deesterifying the pectin to a degree of esterification of less than about 45 mm; (0) washing the plant material in soft water; and (CI) drying the plant material to a moisture content of less than 15%. Preferred is a method comprising:

The method of carrying out the deesterification is not critical and can be, for example, enzymatic or chemical deesterification.

Chemical deesterification of pectin can be carried out at acidic or alkaline pH. Acidic deesterification is undesirable because it is slow and results in both divalent ion extraction and hemicellulose degradation. Alkaline deesterification is preferred, but care must be taken.

Pectin methyl ester is degraded by a β-dissociation mechanism, therefore pH and temperature should be carefully controlled. Enzymatic deesterification can be performed using the enzyme pectin esterase. This is particularly advantageous when citrus peels are used as starting material since ff[pectin esterase is naturally present in citrus peels. Alternatively, deesterification can be carried out by noking the plant material particles into a solution of alkali metal hydroxide.

The rate of reaction increases with the concentration of hydroxyl ions, so the higher the pH, the faster the reaction will be. Therefore, the pH should be higher than about 8, preferably higher than about 9. Too high pH values tend to result in the removal of hemicellulose and other desirable substances. Therefore, the pH should not exceed about 13 (
Preferably lower than about 12. A degree of esterification of less than 45% is generally achieved after about 2 minutes at pH 9.5 or above. Since the β-dissociation is highly temperature dependent, approximately 25°C
The following temperatures are preferred. Prolonged contact of the plant material with the alkaline hydroxide solution results in a progressively lower degree of esterification of the pectin. It is generally not necessary to continue this deesterification step for longer than about 2 hours. The reason is that there is hardly any additional benefit to be gained by doing so.

Cleaning of the material is very important, as it is necessary to remove alkaline substances and excess soluble substances. Washing can be done using water or using organic solvents. The latter has the advantage that chloroform-soluble lipids that may be present in the material are generally removed to a large extent by organic solvents, such as acetone, but not by washing with water. The washing step may conveniently be carried out as follows. Excess liquid is drained from the reaction mixture of the deesterification step. Sufficient wash liquid (ie, water or organic solvent) is then added to obtain a slurry having a solids content of about 2 inches. The slurry is allowed to equilibrate for approximately 5-15 minutes, and then the wash liquid is drained. This washing step can be repeated. The number of washing steps is determined by the amount of contaminants in the starting material and the desired composition of the final absorbent material. Typically two or three washing steps will be required.

After excess cleaning liquid has been drained off after the final cleaning step,
The liquid content of the residual material is on the order of about 90 parts. this is,
In order to obtain an absorbent material with optimum absorbency, it must be reduced to less than about 20 inches. Organic solvents (e.g.
If acetone, isopropyl alcohol, or methanol) is used in the cleaning step, this solvent
Can be easily removed by evaporation. The material may also be dried by solvent displacement. That is, after a final wash step with water, the material is slurried in an organic solvent, such as acetone or methanol, then the solvent is drained and the excess is evaporated.

For economic reasons, it is not feasible to use any organic solvent in the aqueous solution. In that case the water would have to be removed using normal drying techniques. This can be either freeze drying, vacuum drying or heat drying. Among these three, freeze-drying is
It is the most attractive because it does not cause disruption of the microcapillaries naturally present in the material. Unfortunately, freeze-drying is also the most expensive drying method of these three.

Thermal drying is the most economically attractive drying method available. If the product with 90 g of moisture from the washing process is dried in r, a paperboard-like material that is not very absorbent is obtained. However, it has been discovered that the material can be dried by spraying in a countercurrent of superheated steam or hot air. The inlet temperature and flow rate should be controlled to produce an outlet temperature of about 0°C to about 75°C. this is,
Resulting in a product having a moisture content of less than 15 parts. Although thermally dried materials have good absorption capacity, the absorption rate of such materials tends to be slow. The rate of absorption can be greatly improved by adding surfactants to the slurry in the final washing step. About 1 to about 3 of the amount of slurry
A moderate amount of surfactant is generally sufficient. The type of surfactant is not critical. Examples of suitable surfactants are nonionic surfactants, such as ethoxylated fatty alcohols.

It is highly desirable to include a bleaching step within the process.

Preferably, bleaching is applied using an oxidizing bleach. Preferable 7. Examples of bleaching agents include hydrogen peroxide, perborates,
Hypochlorite, chlorine dioxide and chlorine. Sodium hypochlorite was the preferred bleaching agent. Ru. For optimal properties of the absorbent material, and optimal safety of absorbent products made from it, excess bleach and electrolytes introduced in the bleaching process must be removed.

Therefore, bleaching is best carried out before the washing step.

Colored compounds may be produced during alkaline deesterification, so if alkaline deesterification is used (as opposed to enzymatic deesterification), the bleaching step
It is best carried out after the deesterification process '8. To improve the effectiveness of bleach utilization, it is desirable to include a washing step after the deesterification step and before the bleaching step, especially when citrus peel is the starting material. Therefore, if alkaline deesterification and bleaching is used (7-), the process sequence is as follows: 1(a) Grind the pectin-containing plant material to a particle size of about 0.05 rrm to about 3 mm; b)
Process a The pectin-containing active material particles obtained in (a) are
(C) The product of step (11) is soaked in a solution of alkali metal hydroxide in water for about 2 minutes to about 120 minutes at a temperature of about 9 to about 12 degrees H and a temperature of about 5 degrees Celsius to about 50 degrees Celsius. (d) bleaching the product of step (1) for about 5 minutes to about 60 minutes; (e) washing the product of step (d) in soft water; and (f) step 8 (+3). dry the product.

The effect of bleaching is twofold. It removes coloring substances, thereby greatly improving the appearance of the absorbent material obtained by splashing and making it more suitable for use in consumer products, such as disposable diapers, sanitary napkins, etc. Bleaching also tends to break down chloroform-soluble lipids into water-soluble fragments. Therefore, the bleaching process significantly reduces the amount of chloroform soluble material in the final product.

Removal of chloroform-soluble lipids is particularly important when citrus peel is used as a starting material. Citrus peels contain large amounts of such chloroform-soluble lipids, and if water (as opposed to an organic solvent) is used in the aqueous cleaning step, bleaching reduces the amount of chloroform-soluble lipids to the desired amount. Helpful when decreasing.

Whole citrus peels can be used as a starting material, but the fried parts greatly increase the load of chloroform-soluble lipids and coloring substances. Therefore, it is desirable to remove the fried portion of the skin. The fries are mechanically shaved by machines that are commercially available and designed for this purpose. Such fittings typically leave about 30 parts of fried on the albedo. When these machine-grained hides are subjected to the aforementioned processes (including a bleaching step), an absorbent material is obtained that is slightly less absorbent than the material obtained from the all-albedo starting material (handmade). has been discovered. Whole citrus peels can also be used as a starting material. Highly tolerable absorbent materials can be prepared therefrom despite the expense of multiple uses of bleaching chemicals.

Sugar beets naturally contain only small amounts of chloroform-soluble lipids. Therefore, when processing sugar beet pulp,
If absorbency is the only concern, the bleaching step can be dispensed with. However, upon alkaline deesterification, sugar beet pulp develops a persistent green color, and a bleaching step may be highly desirable or even necessary from an aesthetic standpoint.

Processing of other pectin-containing raw materials will be apparent from the foregoing. If the starting material has a low chloroform-soluble lipid content and contains almost no coloring substances, or if the aesthetics of the absorbent material is relatively unimportant (
For example, when intended for industrial use), the bleaching step can be dispensed with. The choice of deesterification method (enzymatic or alkaline treatment) is largely determined by economic considerations. That is, enzymatic deesterification is relatively slow;
Alkaline processing is faster and better suited for continuous operation of the process. Similarly, the choice of cleaning liquid (water or organic solvent) is determined by economic considerations that would be familiar to those skilled in chemical engineering.

In this specification, "common absorbent materials" are those used or proposed for use in absorbent products, such as disposable diapers, sanitary napkins, disposable towels, toilet paper, toilet tissues, incontinence pads, etc. means absorbent material. Examples are therefore absorbent fibers and water-insoluble hydrogels. Examples of absorbable fibers are vegetable fibers, such as cotton fibers, wood pulp fibers (e.g., kraft pulp fibers, chemical-thermomechanical pulp fibers), and manila, sisal, heniken, cantara, istre, mauritillus, hornium, sansevieria, caroa. , mackerel, broomroot, flax, hemp, ramie, kouma, tonaf, roselle, bonten, coir and kapok fibers. The fibers are probably "absorbent materials of plant origin"
but does not belong to said term as defined herein, but rather "ordinary absorbent material"
It should be noted that this term is encompassed by the following terms. Examples of absorbent fibers also include man-made fibers such as rayon, cellulose acetate, cellulose triacetate, alginate fibers, protein fibers, polyamides, nylon 6.6, nylon 6
, aromatic polyamide, polyester, acrylic fibers, polyethene and polypropene fibers. Many man-made fibers are hydrophobic, but can be made hydrophilic using techniques disclosed in the art. Hydrophobic fibers are described in U.S. Patent No. 3,916,
447, and U.S. Pat. No. 4,100,324.
Hydrophilicity can be achieved by surfactant treatment, as disclosed in the patent specification. Thermoplastic fibers can be further made hydrophilic by coating with hydrophilic substances, such as silica, or by surface grafting with fibrous hydrophilic groups.

As used herein, "hydrogel" refers to an inorganic or organic compound that is capable of absorbing aqueous liquids and retaining them under moderate pressure. For good results, the hydrogel must be water-insoluble.

Examples are inorganic substances such as silica gel and organic compounds,
For example, crosslinked polymers. Crosslinking can be by covalent, ionic, van der Waals, or hydrogen bonding. Examples of polymers include polyacrylamide, polyvinyl alcohol, tyrene-maleic anhydride copolymer, polyvinylpyridine, hydroxypropylcellulose, carboxymethylcellulose, polyvinylmorpholinone, vinylsulfonic acid polymers and copolymers, polyacrylate, Acrylamide, polyvinylpyridine, etc. Other suitable hydrogels are U.S. Pat.
No. 01.236.

Particularly preferred polymers for use in the present invention are hydrolyzed acrylonitrile-grafted starches, acrylic acid-grafted starches, polyacrylates, and isobutylene-grafted starches.
maleic anhydride copolymer, or a mixture thereof.

Methods for making hydrogels are described in U.S. Pat. No. 4.076.663, U.S. Pat. No. 4.286.082, and U.S. Pat.
1.815 Specification, No. 3,670,731 Specification,
Specification No. 3.664.343, No. 3.783.871
and Belgian Patent No. 785,858.

One particular embodiment of the invention is an absorbent structure comprised of plant absorbable materials and conventional absorbent materials. Cellulose fibers, especially wood bulb fibers, are preferred for use in the present invention. In a preferred embodiment, the absorbent structure comprises from about 5 parts to about 80 parts plant absorbent material and from 20% to about 95 parts wood pulp fiber composition.

Plant absorbent materials and conventional absorbent fibers can be combined in a variety of ways to form the absorbent structures of the present invention. For example, % plant absorbable material could be mixed with normal absorbable Nl fibers and the mixture made into a web. Alternatively, particulate plant absorbent material can be incorporated into a web of conventional absorbent fibers in a pattern to create increased absorbent capacity within the absorbent structure. Alternatively, the plant absorbent material can be pressed into a sheet and the sheet then placed against or sandwiched between webs of conventional absorbent fibers. Other implementations will be apparent to those skilled in the art.

The plant-absorbable material as obtained from the method is generally in granular or fibrous form. The material can be formed into sheet form by applying pressure to the wet-formed material and then drying.

Another specific embodiment of the invention is an absorbent material of plant origin,
Absorbent structures consisting of customary absorbent fibers, such as woodknot fibers, and absorbent materials of water-insoluble hydrogels, in particular polyacrylate-grafted starches or slightly crosslinked polyacrylate substances. 40% to about 60% wood pulp fibers, about 20% to about 40% plant-absorbable material, and about 20% to about 25% water-insoluble hydrogel
Absorbent structures comprising the following are preferred.

The absorbent structure may conveniently be manufactured by using conventional equipment designed for air forming of hydrophilic fibrous webs. In such devices, the web is typically formed by entraining hydrophilic fibers into an air stream and depositing the fibers onto a wire mesh screen. The desired mixture of hydrophilic fibers and hydrogel particles can be prepared by metering the desired amount of plant-absorbent material particles or fiber particles into the air stream at a point just upstream of the wire mesh screen. The web formed on the screen is then passed through calender rolls that are set at a nip pressure that produces an absorbent structure of the desired density. This embodiment of the method includes:
only minor modifications of the usual equipment for the production of absorbent structures,
It will therefore be clear that it is necessary to install a metering device for the addition of the plant-absorbable material particles or fibers. In some cases, it may be necessary to use a finer mesh size in place of the standard wire mesh screen on the equipment. This need may arise when relatively small amounts of hydrogel particles are used and/or when the standard screen mesh size is relatively coarse.

In some cases, the construction can be made to a higher density (i.e., about Q, l
g/cms). Densified absorbent structures have good absorbency despite the reduced void volume of such structures. This is due to the wet elasticity exhibited by the material. It recovers virtually all its original capacity once moistened in the densified state and therefore exhibits high absorbency in both the uncompacted and compressed states (clearly lower absorbency and (different from wood pulp fiber web). Therefore, densified structures have highly desirable properties (low bulk, high absorbency) for absorbent products such as disposable diapers, incontinence pads and sanitary napkins.

The densified structure has a density of about 0.2 g/amp'~
about 1 g/Cm3, preferably about 0.3 to about 0.5 g/
It has Qm3.

Alternatively, the absorbent structure may be formed by attaching a web of absorbent fibers to a sheet of plant absorbable material. In some cases, the sheet and/or web are
It can be wrapped within an envelope tissue to increase the lateral strength of the structure.

The base absorbent structure may be formed as follows. Absorbent fibers, such as wood pulp fibers and particles of plant absorbent material are mixed into an aqueous slurry, incorporated with a surfactant, and foamed with air. The foamed slurry is then transferred onto a wire screen and dewatered, preferably by applying a vacuum to the underside of the wire screen. The foamed mat thus obtained is then dried in air. A more detailed description of the foaming process is disclosed in US Pat. No. 3,871,952.

Absorbent structures of the present invention include structures consisting of plant absorbable materials and water-insoluble hydrogels.

Examples include structures consisting of a mixture of hydrogel particles or fibers and particles or fibers of a plant-absorbable material; and laminates consisting of one or more sheets of hydrogel material and one or more sheets of a plant-absorbable material, e.g. a laminate of one sheet of water-insoluble hydrogel material placed against a sheet of bioabsorbable material, or a "sandwich" type laminate consisting of a sheet of water-insoluble hydrogel material placed between two sheets of plant-absorbable material. be. Many variations are possible, as will be apparent to those skilled in the art. A preferred embodiment is an absorbent material comprising a mixture of about 50 to about 95 grams of a plant-absorbable material and about 5 to about 5,096 grams of a water-insoluble hydrogel. It is a structure. Both the hydrogel and the plant-absorbable material are preferably in granular or fibrous form.

The mixture has a density of approximately 1 g/C without significant loss of absorption capacity.
m3 can be densified. Densified structures have better wet and dry strength than non-densified structures. Additionally, densified structures can be used to make low bulk absorbent products such as diapers and sanitary napkins that are highly desirable from a consumption standpoint. Therefore, densified structures having a density of about 0.2 to about 1 g/0 m3 are preferred. More preferred are structures having a density of about 0.3 to about Q, 5 g/ams.

Excellent absorbent structures are also obtained when mixing hydrophilic fibers, particles or fibers of plant absorbent materials, and particles or fibers of water-insoluble hydrogels. The three components can be mixed in any ratio. Preferred are structures comprising from about 30% to about 80% hydrophilic fibers, from about 20% to about 50% plant-absorbable material, and from about 5% to about 50% water-insoluble hydrogel.

Approximately 30 to 70 units of hydrophilic fiber, approximately 20 units of plant-absorbable material
from about 5% to about 40%, and from about 5% to about 2% water-insoluble hydrogel
Structures consisting of 5% are even more preferred.

The performance of these three-component structures reduces the structure to a density of approximately 0.2
to about 1 g/am”, preferably about 0.3 to about 0.6 g/am”
This can be improved by increasing the density to am'.

In order to improve the strength of the absorbent structures of the present invention, the structures have a low i! - (typically about 0.5 chill about 5%) thermoplastic long fibers. Long fibers, as used herein, refer to fibers having a length greater than about 1 inch (about 2.5 cm). Suitable thermoplastics are inexpensive polymers such as polyethylene, polypropylene and polyester. Polyester fibers are preferred because they are more hydrophilic than polyolefin fibers. The use of thermoplastic fibers in absorbent structures for the purpose of modifying the strength of such structures is described in U.S. Pat. No. 4.307.721 and U.S. Pat. and US Pat. No. 4.1 (10,329).

Due to their specific properties, the absorbent structures of the present invention
Highly suitable for use in disposable absorbent products. By "absorbent product" herein is meant a consumable product that is capable of absorbing significant amounts of water and other liquids, such as body fluids. Examples of absorbent products are disposable diapers, sanitary napkins, incontinence pads, paper towels, toilet paper, etc.

The absorbent structures of the present invention are particularly suitable for use in products such as diapers, incontinence pads, and sanitary napkins. It is possible to design absorbent products that are thin and forceful but still have a higher absorbent capacity than sufficient to avoid the embarrassment of breakage.

The flexibility of the structure ensures comfort for the wearer and a good fit of the absorbent product.

Disposable diapers comprising the absorbent structure of the present invention are manufactured using conventional diaper manufacturing techniques, but with the absorbent structure of the present invention replacing the wood pulp fiber web core typically used in conventional diaper pressures. can be manufactured by using Thus, from top to bottom, a disposable diaper consists of a topsheet (a non-woven hydrophobic tissue, e.g. needle punched polyester), an absorbent structure, and a waterproof, adaptive backsheet (e.g. an embossed caliper about z
, 3 mils). In some cases, the absorbent structure can be wrapped within an envelope tissue (wet tough tissue paper). This type of disposable diaper is disclosed in U.S. Patent No. 3,95
No. 2,745, and U.S. Patent No. 3,860,0
Further details are disclosed in the specification of No. 03. The diaper is
Additionally, a second absorbent core can be provided, such as a wood pulp fiber web or a sheet of water-insoluble hydrogel.

The absorbent structure of the present invention is highly absorbent and remains thin and flexible, making it highly suitable for use in sanitary napkins. As in the case of disposable diapers, sanitary napkins that utilize the absorbent structure of the present invention simply include the absorbent structure of the present invention in place of its absorbent core (typically a web of wood pulp fibers). Obtained from ordinary sanitary napkins by using. Such replacement can be on a weight/weight basis resulting in a reduction in capacity and an increase in capacity. Or the replacement can be on a less than equal weight basis, thereby sacrificing a portion of the increase in absorbent capacity in favor of a greater reduction in bulk.

An example of a sanitary napkin consists of a pad of absorbent structure of the invention, a hydrophobic topsheet, and a liquid-impervious bottomsheet. The topsheet and packsheet are placed on opposite sides of the absorbent structure.

In some cases, the absorbent structure is wrapped within an envelope tissue. Suitable materials for the topsheet, bottomsheet and envelope are well known in the art. A more detailed description of sanitary napkins and materials suitable for use therein can be found in US Pat. No. 3,871,378.

Example I Florida Valencia oranges were juiced in an AMO extractor and hand peeled to remove fries and racks. Albedo was ground in a Lil Shell grinder.

Pulverized raw material 23 bond (approximately 10 kg) with 11.96% solids
was slurried in 75 lb/d water (approximately 34 kg) to prepare a 2.8% solids slurry.

The slurry was titrated to pHg, 5 and maintained at this pH for 30 minutes by caustic addition. The titration is I
N hydroxide) IJum 1.251 was heated. the material is,
Dehydrated in a basket centrifuge. It is washed with water 75 Bond (approx. 34 kg) with a spinning motion in a centrifuge and dehydrated again to give a 14.7 Bond 14.7 Bond (6.7 kg) of 10.71% solids resulting from it. , 43 pounds of water (19,51 cg
) to prepare a 2.8% solids slurry. 5.254 ml of sodium hypochlorite solution was added to the slurry and mixed for 15 minutes. The bleached material was dehydrated in a centrifuge. It moves water 75 bonds (approximately 34 kg) while spinning
was washed again and then dehydrated. This is the solid H1
, yielding 12.2 bonds (5,5 kg) of 3% material (
yield 45.7%).

The material was lyophilized to a 10% moisture content. The chemical composition was determined by the analytical method described above.

A, General (groθ8) Chemical composition Ingredients Composition (dry weight) Pectin 44.0 Other polymers 52.7 Chloroform-soluble lipids 0.70 Non-lipid organic substances 2.49 Water-soluble metal salts, 0.13 B , Distribution of pectin components Methyl esters 14.4 Divalent metal salts 29.8 -Valent metal salts 55.8 Absorbent materials derived from citrus peels are made from wood pulp fibers and the ratio of citrus peel material to wood pulp fibers is 1, respectively. :19.
Mixed at 1:9.1:4.1:3 and 1:1. The mixture is webbed in a deckle box. The resulting absorbent structure has excellent absorbency.

Example 2 434 g of pulverized sugar beet cattle feed at 16.38% solids was slurried in 31 ml of water to prepare a 2.1% solids slurry. The slurry is titrated to pH 9.5 and maintained for 30 minutes by caustic addition. Titration is IN
12 ml of sodium hydroxide was required. The material was dehydrated in a basket centrifuge. It is water 50 bonds (22,7k
g) and then dehydrated. 462 g of the resulting 12.03% solids percake was slurried in 31 g of water to prepare a 1.6 g solids slurry. 5
．． 500 ml of 25% hypochlorous acid)
Added to this and mixed for 17 minutes. The bleached material was dehydrated in a centrifuge. It was washed again with 50 bonds (22,7 kg) of water with a spin motion and then dehydrated. This is solid 11.2
% material (78% yield).

The material was dried by lyophilization. Its chemical composition was determined by the method described above.

Component Composition (dry weight) Pectin 15.5 Other polymers 76.1 Chloroform-soluble lipids 0.40 Non-lipid organic substances 6.79 Water-soluble metal salts 1.60 B. Distribution of pectin components Polygalacturon Acid Equivalent Thimethyl Ester 22.9 Divalent Metal Salt 25.4 -Valent Metal Salt 51.7 Sugar beet absorbent materials include Nazaan softwood kraft pulp fibers and Nazaan softwood chemical-thermomechanical pulp (OTM)
P) is mixed with fibers in the following ratios:

BOD Sugar beet absorbent material (wt%) 552530 Kraft pulp fiber (wt%) 90 8 (165400TMP
Fibers (% by weight) 515 10 3 (+) The mixture is made into a web using conventional air forming equipment. The resulting structure has excellent absorbency.

Example 3 A citrus peel absorbent material prepared as described in Example 1 is mixed with Southern softwood kraft bulb fiber in a ratio of 2!
Dry mixed at step 3. A web with dimensions 15 x 25 Bm was created in a batch air forming machine.

The web is produced using a flat hydraulic press with a dry density of 0.3
g/am3 (corresponding to a thickness of 2.6111 m). The absorbent structure has a weight of -1130g and a final tsubo II
1 soo g/m''.

A disposable diaper using the absorbent structure was manufactured as follows.

The absorbent construction has a basis weight of approximately 12 bonds/s, ooo square feet (approximately 20 g/m"), and a dry tensile strength in the machine direction of approximately 7 oog/in (approximately 275 g/m").
/ am ) and a dry tensile strength in the cross-machine direction of about aoog/inch (about 120 g/am).

The wrapped pad is made of 11 inches of embossed polyethylene film having a melt index of about 3 and a density of about 0.92 g/am.
28 am) was glued onto the backsheet. The ends of the pack sheet were folded onto the wrapped pad and bonded with adhesive. Finally, the absorbent pad is made from a topsheet of a material that is hydrophobic but water/urine permeable (a web line from the Kendall Company of Orball, Mass., consisting of non-woven rayon bonded with acrylic latex). wabxine) No,
F 6211”].

Control diapers with the same design have a density of 0.3g/
cm” of absorbent structure with a density of 0.1 g/
am" (basis weight 960 g/m", core weight 36 g).

To test the performance of the diaper, the diaper was worn by a normal infant in a leakage study.

The infants were allowed to play in the nursery school set up at the time of the study. The diaper was left on the infant until leakage occurred. To speed up the test, the diapers were preloaded with a predetermined amount of synthetic urine.

After leakage occurred, the diaper was removed and weighed to determine the amount of liquid absorbed. At the point where the damage occurred,
The load X, defined as fL(g) of absorbed liquid/g of absorbent material, was calculated.

The absorbent capacity of the diaper containing the absorbent structure according to the present invention is that the core weight is 6g less (30g compared to 36g).
) was equal to the ability of the control diaper. Thus, using the absorbent material of the present invention, a significant reduction in the consumption of wood pulp fibers is obtained without sacrificing absorbent performance.

A similar diaper is made using the sugar beet absorbent material of Example 2 in place of the citrus peel absorbent material. Essentially the same results are obtained.

Example 4 A sanitary napkin using the absorbent structure according to the invention is manufactured as follows.

The absorbent structure made as in Example 3 had a confinement pressure of 6. I R8I (approx. 7 x 10”N/
m") to a density of approximately 0-4 g/cm". Web measures 8 inches x 2 inches (approximately 20 cm x 5 am) with tapered ends
is cut into pads. On this pad, 2 x 5 inches
A second pad C (approximately 13 am x 5 am rectangular) is placed. - The combined pad structure is
Embossed Rigid Polyethylene Waterproof Backing Sheet (8" x 2") with Embossed Calipers 2.3 Mil
Approximately 200m x 5cm), tapered key K, pair
C@U-reru. The structure has a density of approximately 0.03 g/cm
” and a caliper of approximately 2.3 mils.
Covered with a top sheet of dollar punched polyester non-woven fabric.

The structure covered in this way has a measurement overlap of 15g/am.
9 of hydrophobic spinbond nonwoven polyester with
inch x 3 inches (approximately 23 cm x 74 am)
@1 is placed on the bottom sheet of the The bottom sheet is pre-folded upwards by hot pressure to bond the stacked sheets together. The resulting absorbent structure is useful as a sanitary napkin and has excellent properties of menstrual fluid absorption and containment.

Example 5 A polyester reinforced absorbent structure was manufactured as follows.

Two grams of 6 denier polyester fiber with a fiber length of about 4 inches (about 1 ocm) was carded and made into a welded web. The web had a basis weight of about 0.5 ounces/square yard (about 19 g/II]2).

6 inches x 10 inches (approximately 15 am x 25 am
) web was placed on a wire screen covered with tissue.

The mixture consists of particles of citrus peel absorbent material (produced as described in Example 1) and particles of acrylic acid grafted starch ["SUNWET" (S) from Sanyo Co., Ltd., Japan.
15 g of this mixture was poured onto a polyester fiber web and forced by lowering the air pressure under the wire screen. The resulting structure was compressed to a density of 0.3 g/am'' in a flat hydraulic press. The final composition was as follows.

Citrus Peel Absorbent Material 12 g 76.4% Acrylic Acid Grafted Starch 3 g 19.1% Polyester Fiber 0.7 g 4.5% Absorbent Structure was used in the manufacture of diapers as described in Example 3 .

Diapers containing these absorbent structures have a density of 0,
1 g/am" and a basis weight of 960 g/m" (weight t36 g), the absorbent capacity was 15% to 22 orders of magnitude higher at the leak point than the control diaper containing a wood valve fibrous web having a basis weight of 960 g/m" (weight t36 g).

This embodiment of the invention thus allows the production of absorbent products with higher absorbent capacity and reduced bulk compared to conventional diapers containing a wood bulb fiber web as the absorbent core.

The absorbent structure was manufactured using a sugar beet absorbent material prepared as described in Example 2 and a 411 mixture of isobutylene and maleic anhydride copolymer (Nigel 201 from Kran, Japan). be done. Substantially similar results are obtained.

Example 6 The sugar beet absorbent material prepared as described in Example 2 was made into a diaper core test pad as follows. 4 inches x
A 4 inch (approximately 10 x 10 am) square tissue is
placed on a flat surface. BAN on the tissue 2.
42 g was uniformly spread. Another 4 inch by 4 inch (approximately 10 x iOam) square of tissue was placed in the seventh. Two such pads were manufactured. The first pad remains uncompressed, while the second pad is placed between flat steel plates in a hydraulic press and has a density o, 3
The absorbency of the compressed pad was essentially equal to that of the uncompressed pad.

Example 7 A sugar beet absorbent material was made as described in Example 2, except that the drying sugar beet absorbent material included solvent replacement with Improper Tool. Sugar beet absorbent material.

Particles of Southern slash pine kraft bulb fiber and polyacrylate grafted starch water-insoluble hydrogel [Sunwet IM 1000° from Sanyo Co., Ltd., Japan] Approximate composition 3 starch 10 t, acrylic acid 22%, sodium acrylate 68 t , methylenebisacrylamide (crosslinking agent) 0.
2%).

The materials include the following amounts (by weight): 50 wood valve fibers
H.32 sugar beet absorbent material was mixed with 18% polyacrylate grafted starch. The mixture was formed into a web with a weight of 0.144 g/m2 by air forming. The web has a density of approximately 0.25 in a hydraulic press.
g/Qm”.The web was then densified to 1
0 x 16 inch (approximately 25 x 40 am) rectangular webs were cut. The core was wrapped and wrapped in wet strength tissue and incorporated into a diaper as described in Example 3.

[Brief explanation of drawings]

FIG. 1 represents a flowchart of an analytical protocol used in characterizing plant-based absorbent materials used within absorbent structures. December 6, 1980 Director General of the Patent Office Manabu Shiga 1 Indication of the case 1982 Patent Application No. 166665 2 Name of the invention Made of plant-absorbable material Absorbent structure 3 Relationship with the case of the person making the amendment Patent applicant The, Brocter, End, Gamble, Company 4 Agent November 7, 1980 (Delivery date November 27, 1981) 6 Subject of amendment The applicant's section of the application, power of attorney, and drawings. 7 Contents of amendment (1) As shown in the attached sheet. (2) Engraving of drawings (no changes in content). (1) -26-

Claims (1)

Claims: 1. (1) By weight of the absorbent material of plant origin: (a) from about 15% to about 60% pectin, less than 50% of which is in the form of divalent metal salts; )) about 1 substance selected from the group consisting of cellulose, hemicellulose, lignin, and mixtures thereof.
(C) 0% to about 4% chloroform soluble lipids; and (d) 0% to about 35% non-lipid organic matter extractable in a mixture of chloroform, methanol and water, said mixture comprising: Volume ratio of chloroform to methanol to water 2 (14
Approximately 1% ~ plant-derived absorbent material consisting of
and (2) from about 14 to about 99% of conventional absorbent material. 2. The absorbent structure of claim 1, wherein the pectin has a degree of esterification of about 1% to about 45. 3. The absorbent structure of claim 1, wherein less than 30% of the pectin is in the form of calcium salts. 4. The absorbent structure of claim 1, wherein the plant-derived absorbent material contains 0% to about 1% chloroform-soluble lipids. 5. Absorbent material of plant origin with 0% non-lipid organic matter extractable in a mixture of chloroform, methanol and water
10. The absorbent structure of claim 1, wherein the absorbent structure contains about 10% and wherein the mixture has a volume ratio of chloroform to methanol to water of 20:411. 6. Plant-derived absorbent material contains water-soluble metal salts from 0% to about 6
Absorbent structure according to claim 1, characterized in that %. ? , (1) By weight of absorbent material of plant origin, (a)
Pectin has a degree of esterification of about 15% to about 60%, and has a degree of esterification of about 1% to about 45%;
(b) a substance selected from the group consisting of cellulose, hemicellulose, likunin, and mixtures thereof;
(C) Chloroform soluble lipids: 04 to about 1%, (d)
0 to about 10 parts of non-lipid organic material extractable in a mixture of chloroform, methanol and water, said mixture having a volume ratio of chloroform to methanol to water of 20:411
(e) a plant-derived absorbent material consisting of a water-soluble metal salt from about 0 parts to about 6 parts, and (2) a conventional absorbent material from about 1 part to about 99 parts. An absorbent structure characterized by: 8. The absorbent structure of claim 7, wherein the plant-derived absorbent material is prepared from citrus peel, sugar beet pulp, apple pulp, or mixtures thereof. 9. (1) By weight of absorbent material derived from citrus peel (
a) Pectin about 30 parts to about 60 parts (the pectin is
(b) a mixture of cellulose and hemicellulose having a degree of esterification of less than about 20% and less than about 30% of the pectin is in the form of a calcium salt;
(C) 0% to about 1% chloroform-soluble lipids (in 0% to about 10% non-lipid organic matter extractable in a mixture of chloroform, methanol and water, said mixture containing chloroform and methanol) (8) a citrus peel-derived absorbent material comprising from about 1 part to about 99 parts of a water-soluble metal salt, and (2) a conventional absorbent material. An absorbent structure characterized by comprising about 1 to about 99 parts. 10. (1) By weight of sugar beet-derived material (a)
pectin from about 15 parts to about 35 parts (the pectin has a degree of esterification of less than about 45 parts and less than about 30 parts of the pectin is in the form of calcium salts); (b) a mixture of cellulose and hemicellulose; (Q) about 0% to about 1% chloroform soluble lipid; (d) 0% to about 10% non-lipid organic matter extractable in a mixture of chloroform, methanol and water; , volume ratio of chloroform to methanol to water 20:4+
1), (θ) a sugar beet-derived absorbent material consisting of a water-soluble metal salt of about 0 to about 6%, about 1 to about 99%;
and (2) an absorbent structure comprising from about 1% to about 99% of conventional absorbent material. 1. The absorbent structure of claim 1, wherein the conventional absorbent material is selected from the group consisting of absorbent fibers, water-insoluble hydrogels, and mixtures thereof. 12. The absorbent structure according to claim 1, wherein the conventional absorbent material is an absorbent fiber. 13. The absorbent structure according to claim 12, wherein the absorbent fiber is a cellulose fiber. 14. The absorbent structure according to claim 13, wherein the cellulose fibers are wood pulp fibers. 15. The absorbent structure of claim 14, comprising from about 5% to about 80 qb of plant absorbable material and from about 20% to about 95% wood pulp fibers. 16, about 40 parts to about 60 parts wood pulp fiber, about 20 parts to about 40 parts plant-absorbable material, and about 15 parts to about 25 parts water-insoluble hydrogel. sexual constructs. 17. Claim 15, which is a web of wood pulp fibers having particulate plant-absorbable material dispersed therein.
Absorbent structures as described in Section. 18. The absorbent structure of claim 15, characterized by a sheet of plant absorbent material and a wood pulp fiber web. 19. The absorbent structure of claim 15, wherein the third component is about 0.5% to about 5% thermoplastic long fibers. 20. The absorbent structure of claim 1, wherein the conventional absorbent material is a water-insoluble hydrogel. 21. The absorbent structure of claim 20, comprising about 50% to about 95% plant-absorbable material and about 5% to about 50% water-insoluble hydrogel. 22. The water-insoluble hydrogel is selected from the group consisting of hydrolyzed acrylonitrile-grafted starches, acrylic acid-grafted starches, polyacrylates, copolymers of isobutylene and maleic anhydride, and mixtures thereof. The absorbent structure according to item 4. 23. Approximately 0.5% or more of thermoplastic long fibers as the third component
21. The absorbent structure of claim 20, characterized in that the absorbent structure has approximately 5 inches. 16. The absorbent structure of claim 15, having a density of about 0.2 to about 1 g/am3. 25. The absorbent structure of claim 20, having a density of about 0.2 to about 1 g/cm. 26. The absorbent structure of claim 20 having a density of about 0.3 to about 0.5 g/cm.
Absorbent structure according to claim 24. 27, having a density of about 0.3 to about 0.5 g/0 m3;
Absorbent structure according to claim 25. 28, (a) Liquid-impermeable backing sheet, (1))
A disposable diaper comprising: a hydrophobic topsheet; and an absorbent structure according to claim 1, said structure being placed between a backing sheet and a topsheet. . 29. The disposable diaper of claim 28, wherein the absorbent structure is wrapped within an envelope tissue. 3O, (a) Liquid-impermeable backing sheet, (1))
Hydrophobic top sheet, and (C) Claim 1
Disposable diaper, characterized in that it comprises the absorbent structure of item 3, wherein the structure is placed between a backing sheet and a topsheet. 31. (a) a liquid-impermeable lining. Tensioned sheet, (1))
a hydrophobic topsheet; and (Q) an absorbent structure according to claim 16, wherein the structure is placed between the backing sheet and the topsheet. , disposable diapers. 32. (a) liquid-impermeable backing sheet; (b)
a hydrophobic topsheet; and (Q) an absorbent structure according to claim 20, wherein the structure is placed between a backing sheet and a topsheet. , disposable diapers. 33. (a) Liquid-impermeable backing sheet, (1))
a hydrophobic topsheet; and (3) an absorbent structure according to claim 5, wherein the structure is placed between a backing sheet and a topsheet. Disposable diaper. 34. (a) Liquid-impermeable lining sheet, (1))
a hydrophobic topsheet; and (Q) an absorbent structure according to claim 26, wherein the structure is located between a backing sheet and a topsheet. , disposable diapers. 35. (a) Liquid-impermeable backing sheet, (1))
a hydrophobic topsheet; and (0) an absorbent structure according to claim 1, wherein the structure is located between a backing sheet and a topsheet. , sanitary napkins.