KR20240072610A - Preparation method of biodegradable highly absorbent material using crustacean shell and use thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing a biodegradable superabsorbent using crustacean shell and its use. The absorbent power of the biodegradable superabsorbent manufactured according to the manufacturing method of the present invention is sufficient to meet the standard value, and as a result of the biodegradation test, it is compared to the conventional one. Since it has a significant biodegradation effect compared to synthetic absorbents, it can be usefully used in sanitary products aimed at absorbing moisture, etc.

Description

Manufacturing method of biodegradable highly absorbent material using crustacean shell and use thereof {Preparation method of biodegradable highly absorbent material using crustacean shell and use thereof}

The present invention relates to a method for producing a biodegradable superabsorbent using crustacean shell and its use.

Superabsorbent polymer (SAP) refers to a cross-linked polymer that can absorb a large amount of liquid, swell to form a hydrogel, and retain the absorbed liquid. Representative types of synthetic polymer absorbers include crosslinked hydroalkyl (meth)acrylic acid, N-vinylpyrrolidone, ethyloxide, acrylamide, (meth)acrylic acid, and poly(vinyl alcohol), and crosslinked poly(acrylic acid) (PAA). ) occupies most of the market.

Products based on polymer absorbers currently sold on the market include a variety of sanitary products such as sanitary pads for women and diapers for infants and adults, most of which use petrochemical-based polymer absorbents that are harmful to the human body. Sanitary products made from the above petrochemical-based polymer absorbent are not biodegradable after use, so they cause various serious environmental and economic problems during landfill or incineration when disposed of. To solve these problems, the development of nature-friendly premium sanitary products is needed. / Although it has been very active both internally and externally, the performance of the product is not only very low in water retention capacity and absorbency under pressure compared to existing chemical products, but also causes heat generation, skin maceration, and itching due to harmful substances.

Meanwhile, chitin is the second most abundant polymer in the natural environment after cellulose, and is composed of N-acetylglucosamine [poly-b-(1-4)-N-acetyl-D-glucosamine] sequentially bound to each other. It is a polymer. It is also the main component of the shells of crustaceans such as crayfish, crabs, and shrimp, the exoskeleton of insects such as scarabs, cicadas, and grasshoppers, the skeleton of molluscs such as squid, and the cell walls of fungi such as molds, yeast, and mushrooms. Chitin is synthesized in various living organisms, so it is considered a biopolymer. It has the chemical property of being insoluble in water, and through a chemical process called deacetylation, it is a water-soluble substance called chitosan that can be applied for various purposes. It is transformed.

Chitin has a structure similar to cellulose in which 2-acetamino-2-deoxy-D-glucose is bonded to β-(1,4), and the hydroxy group at the C-2 position is replaced by an acetamin group, and the C3-OH… The intermolecular bond of C5 and NH… O=C and C6-OH… It is stabilized by intermolecular hydrogen bonds at O=C. Depending on the arrangement of the molecular chain in the crystal structure, there are three stereoisomers: α-, β-, and γ-. α-Chitin is the densest form because two chains are stacked anti-parallel to each other, while β-chitin is a form in which the chains are arranged parallel to each other, with C ₃ -OH ^... O ₅ between the same chains and different Although the -NH and -CO groups between chains form hydrogen bonds, it has a less dense structure than α-chitin. γ-Chitin is arranged with one unit chain facing downward for every two pyranose units. α-Chitin is most widely distributed in nature, and is especially contained in arthropod epidermis. β-Chitin exists in a crystalline hydrate state and is a less stable substance that is loosely arranged to allow water to easily permeate between the chains of the crystal lattice. It is most abundant in the bones of cuttlefish. α-Chitin is present in the cysts of arthropods, mushrooms, and Entamoea , and β-chitin can be obtained from the bones of Loligo . Lastly, γ-chitin is present in the cocoon of beetles and the stomach lining of Loligo . The structure of γ-chitin consists of two antiparallel chains and one parallel chain.

Chitin is used as an ingredient in fertilizers to increase crop yields. Fertilizers containing chitin are organic, have low toxicity, and are known to increase yields. Additionally, it is known that treatment with fertilizers containing chitin increases the activity of soil microorganisms and enzymes, helping with harvesting. Crabs, shrimp, etc. have long been sources of chitin, and chitin obtained from them has long been used as a variety of food additives. Finely powdered chitin is used as a food additive and improves the flavor of foods. In addition, it can be added to food to function as an emulsifier. Chitin is also used in the medical field and is known to reduce cholesterol when consumed in humans. It is also used as a material for suture threads used in surgical procedures. Chitin is known to aid the wound healing process and to be naturally biodegradable.

Meanwhile, as absorber-related technology, a method for manufacturing a natural polymer absorber capable of absorbing moisture is disclosed in Korean Patent Publication No. 2018-0028244, and Korean Patent No. 2052113 discloses a method containing red algae extract and a polymer of water-soluble chitin as active ingredients. Although an absorbent with improved absorbent and antibacterial properties and a method for producing the same have been disclosed, a method for producing a superabsorbent using the marine crustacean of the present invention directly and its use have not yet been disclosed.

The present invention was developed in response to the above-mentioned needs. The present invention provides a method for manufacturing a biodegradable superabsorbent using crustacean shell and its use, and the absorption power of the biodegradable superabsorbent manufactured according to the manufacturing method of the present invention is The present invention was completed by confirming that the level was sufficient to meet the standard and that the biodegradation test results showed a significant biodegradation effect compared to conventional synthetic absorbents.

In order to achieve the above object, the present invention (1) crushes and washes the shells or bones of marine crustaceans to a size of 10 cm or less, adds them to a 2-10% (w/v) sodium hydroxide solution, and then washes them for 80 minutes. Removing proteins remaining in the shell or bones of marine crustaceans by heating at ~100°C for 2 to 10 hours;

(2) The shell or bone of the marine crustacean from which the protein has been removed, obtained in step (1), is immersed in a 0.5 to 10% (v/v) acid solution and applied to the shell or bone of the marine crustacean. Removing calcium carbonate by reacting the contained calcium carbonate;

(3) After step (2), the process of step (2) is continued until the ash content of the shell or bone of the marine crustacean from which the calcium carbonate has been removed after removing the acid solution is 5% or less by weight. Repeating steps;

(4) 100 to 500 parts by weight of water, 50 to 150 parts by weight of a compound containing a phosphate group, and 100 to 300 parts by weight of urea based on 100 parts by weight of shell or bone of marine crustacean obtained in step (3). After adding the compound, reacting at 20-40°C for 3-9 hours, followed by washing and primary drying;

(5) heat-treating the first dried reactant in step (4) at 140-180°C for 10-100 minutes, washing the heat-treated reactant with a sodium hydroxide solution to gel it, and washing it with water to swell it;

(6) Fibrillating the reactant swollen in step (5) using a high-speed grinder, homogenizer, or super mass collidor so that the fibril width of the reactant is 3 nm to 3 ㎛. ;

(7) secondary drying of the fibrillated reactant obtained in step (6) at 30 to 100°C; and

(8) pulverizing the secondary dried reactant in step (7) and powdering it to a diameter of 10 to 3,000 ㎛.

In addition, the present invention provides a sanitary product containing a natural biodegradable superabsorbent material manufactured by the above manufacturing method.

The present invention relates to a method for manufacturing a biodegradable superabsorbent using crustacean shell and its use. The absorbent power of the biodegradable superabsorbent manufactured according to the manufacturing method of the present invention is sufficient to meet the standard value, and as a result of the biodegradation test, it is compared to the conventional one. It has a significant biodegradation effect compared to synthetic absorbents.

Figure 1 is a simple process diagram of the biodegradable absorbent manufactured in the present invention.

The present invention (1) crushes and washes the shells or bones of marine crustaceans to a size of 10 cm or less, adds them to a 2 to 10% (w/v) sodium hydroxide solution, and then boils them for 2 to 10 minutes at 80 to 100°C. removing proteins remaining in the shell or bones of marine crustaceans by heating for a period of time;

(2) The shell or bone of the marine crustacean from which the protein has been removed, obtained in step (1), is immersed in a 0.5 to 10% (v/v) acid solution and applied to the shell or bone of the marine crustacean. Removing calcium carbonate by reacting the contained calcium carbonate;

(3) After step (2), the process of step (2) is continued until the ash content of the shell or bone of the marine crustacean from which the calcium carbonate has been removed after removing the acid solution is 5% or less by weight. Repeating steps;

(4) 100 to 500 parts by weight of water, 50 to 150 parts by weight of a compound containing a phosphate group, and 100 to 300 parts by weight of urea based on 100 parts by weight of shell or bone of marine crustacean obtained in step (3). After adding the compound, reacting at 20-40°C for 3-9 hours, followed by washing and primary drying;

(5) heat-treating the first dried reactant in step (4) at 140-180°C for 10-100 minutes, washing the heat-treated reactant with a sodium hydroxide solution to gel it, and washing it with water to swell it;

(6) Fibrillating the reactant swollen in step (5) using a high-speed grinder, homogenizer, or super mass collidor so that the fibril width of the reactant is 3 nm to 3 ㎛. ;

(7) secondary drying of the fibrillated reactant obtained in step (6) at 30 to 100°C; and

(8) pulverizing the secondary dried reactant in step (7) and powdering it to a diameter of 10 to 3,000 ㎛.

In step (1), the shell or bone of the marine crustacean is preferably the shell of a lobster, red crab, snow crab, king crab or shrimp, or the bone of a cuttlefish, and more preferably the shell of a red crab, but is not limited thereto.

In step (2), the acid solution is preferably one of inorganic acids selected from acetic acid, sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid dissolved in water, more preferably an acetic acid solution, but is not limited thereto. no.

In step (4), the compound containing a phosphate group is preferably one selected from monobasic ammonium phosphate, diammonium phosphate ((NH ₄ ) ₂ HPO ₄ ), and sodium dihydrogen phosphate, but is limited thereto. That is not the case.

In step (4), the urea-based compound is preferably selected from urea, thio urea, and dimethyl urea, but is not limited thereto.

In step (6), before fibrillation, CMC (carboxy methyl cellulose), citric acid, konjac, alginic acid, carrageenan, pentane, cyclopentane, hexane, and cyclohexane. After adding one or more selected from cyclohexane, heptane, cycloheptane, butanol, and isobutanol, the swollen chitin may be fibrillated, but is not limited to this.

Between step (6) and step (7), with respect to 100 parts by weight of fibrillated chitin obtained in step (6), any selected from oxidized starch, cationic starch, phosphate starch, carrageenan, konjac, and alginic acid. It may further include adding one to 1 to 40 parts by weight.

Between step (6) and step (7), epichlorohydrin, glyoxal and maleic acid ( It may further include adding 1 to 10 parts by weight of any one selected from maleic acid.

The primary drying in step (4) or the secondary drying in step (7) is drying by heat treatment; Solvent drying by adding any organic solvent selected from methanol, ethanol, isopropanol, butanol, acetone and toluene; Freeze-drying; and vacuum drying; It can be dried using any one drying method selected from among, but is not limited to.

In addition, the present invention relates to a sanitary product containing a natural biodegradable superabsorbent manufactured by the method for producing the natural biodegradable superabsorbent.

The sanitary product is preferably, but not limited to, any one selected from baby diapers, adult diapers, panty liners, sanitary napkins, and tampons.

Hereinafter, the present invention will be described in more detail using examples. These examples are only for illustrating the present invention in more detail, and it is obvious to those skilled in the art that the scope of the present invention is not limited thereto.

Example 1.

(1) The shell of red crab, a marine crustacean, is crushed into pieces less than 10 cm in size, washed, added to 5% (w/v) sodium hydroxide solution, and heated at 90°C for 3 hours to remove the protein remaining in the shell of red crab. has been removed.

(2) The protein-free red sea crab skin obtained in step (1) was immersed in a 1% (v/v) acetic acid solution to react with the calcium carbonate contained in the red sea crab shell to remove calcium carbonate.

(3) After step (2), the acetic acid solution was discarded, the ash content of the red crab shell from which the calcium carbonate was removed was analyzed, and the process of step (2) was repeated until it was 5% or less by weight.

(4) 100 g of red crab shell obtained in step (3) above was reacted in 250 g of distilled water solution containing 75 g of monobasic ammonium phosphate and 200 g of urea at 25°C for 6 hours, then washed and washed at 30°C. , was first dried.

(5) The dried reactant in step (4) was heat treated at 150°C for 60 minutes, then washed with caustic soda solution to gel, and then washed with water to swell.

(6) Add CMC (carboxymethyl cellulose) to 3% by weight of the reactant swollen in step (5), form fibrils of the reactant using a supermass collider, and the width of the fibrils is 1 on average. It was pulverized and fibrillated to be less than ㎛.

(7) The fibrillated reactant obtained in step (6) was dried a second time at 60°C.

(8) The second-dried fibrillated reactant in step (7) was pulverized and powdered to a diameter of 10 to 1,000 ㎛ to prepare a natural biodegradable superabsorbent.

Example 2.

In step (6) of Example 1, CMC was not added, and the remaining steps were pulverized and fibrillated using a super mass colloider so that the width of the fibrils of the reactants was 200 nm on average. Using the same method as in 1, a powder-type biodegradable superabsorbent with a thickness of 10 to 1,000 ㎛ was prepared.

Example 3.

In step (6) of Example 1, the remaining steps were performed in the same manner as Example 1, except that 3% by weight of citric acid was added instead of CMC to fibrillate. A biodegradable superabsorbent in powder form of 10 to 1,000 ㎛ was produced. was manufactured.

Example 4.

In step (7) of Example 1, 20% by weight of cationic starch (a cationic starch with a degree of substitution of quaternary ammonium of 0.9 as corn starch) was added to the fibrillated reactant obtained in step (6). Afterwards, except for drying at 60°C, the remaining steps were the same as in Example 1 to prepare a 10-1,000㎛ powder-type biodegradable superabsorbent.

Example 5.

In step (6) of Example 1, chitin was pulverized and fibrillated using a super mass colloider without adding CMC so that the width of the chitin was 200 nm on average, and the fibrillated reactant in step (7) Except for drying the fibrils by slowly adding 98% ( v/v ) methanol under a vortex at 500 rotations per minute, the remaining steps were the same as in Example 1 to prepare a biodegradable superabsorbent in powder form of 10 to 1,000 ㎛. was manufactured.

Example 6.

In step (6) of Example 1, the remaining steps were carried out in the same manner as in Example 1, except that 5% by weight of pentane was added instead of CMC to fibrillate. was manufactured.

Comparative Example 1 .

Synthetic superabsorbent polymer (SAP) collected by separating extra-large panty-type diapers from Company Y, which are sold on the market, was used.

Comparative Example 2 .

DS228 X2 synthetic superabsorbent (Danson Technology, China) was purchased and used.

Experimental Example 1. Comparative experiment of absorption capacity

The superabsorbent was placed in a filter cloth, immersed in saline solution for 30 minutes, dehydrated using centrifugal force along with the filter cloth, and then the weight (g) of the superabsorbent was measured.

Saline solution absorption rate of absorbents prepared in Examples 1 to 6 and Comparative Examples 1 and 2 Weight of initial absorber (g) After saline solution absorption
Weight of absorbent (%) Absorption rate of absorber (%) Example 1 1.0 18.4 1,740 Example 2 1.0 20.6 1,960 Example 3 1.0 15.8 1,480 Example 4 1.0 21.2 2,020 Example 5 1.0 17.3 1,630 Example 6 1.0 16.8 1,580 Comparative Example 1 1.0 24.1 2,310 Comparative Example 2 1.0 20.7 1,970

In Table 1, the absorption rate of the absorbent was calculated as (weight of the absorbent after saline solution absorption - weight of the initial absorbent) x 100.

As a result, as shown in Table 1, the absorption rate (%) of the absorbents of Examples 1 to 6 of the present invention was found to be 1,480 to 2,020%, and the commercialized synthetic superabsorbent of Comparative Examples 1 and 2 was 1,970 to 2,020%. It was found to be 2,310%. In general, it is known that there is no problem in using a high absorbent material with an absorption rate (%) of 1,000% or more in the production of products such as commercial diapers. Therefore, although the natural superabsorbent has a slightly lower saline water absorption rate than the synthetic superabsorbent, it can be seen that it is sufficient to be used as an absorbent (Table 1).

In the case of natural superabsorbents, the problem of microplastics can be solved by biodegrading at room temperature, and various chemicals that can be included in synthetic superabsorbents (Ministry of Environment certification standard EL324:2017, Annex D. List of allergens and carcinogens) are essentially included. There is an advantage in that it does not work.

Experimental Example 2. Comparison experiment of change in mass according to biodegradation of absorbents

1 g each of the synthetic superabsorbent (Comparative Example 1) and the biodegradable superabsorbent of the present invention (Example 4) were taken to sufficiently absorb water, placed in an oven at 30°C, and the change in weight due to biodegradation for 30 days was measured. To measure the initial dry weight of the superabsorbent, the superabsorbent was washed using filter paper, dried in an oven at 100°C, and then the mass was measured.

As a result, the moisture content of the synthetic superabsorbent was 9.88%, with a dry weight of 1.021g (day 0), and the moisture content of the biodegradable superabsorbent according to the present invention was 13.6%, with a dry weight of 0.985g. After 7 days, 13 days, 20 days, and 30 days, each superabsorbent was washed with filter paper, dried, and its weight was measured.

The weight measured on days 7 to 30 is the weight of the superabsorbent material that was biodegraded and not biodegraded as low-molecular substances were removed by washing, and is listed in Table 2.

It can be seen that the biodegradable superabsorbent, which is a natural superabsorbent, biodegrades at 30°C and rapidly continues to lose weight, but the weight change of the synthetic superabsorbent hardly occurred other than a weight loss of about 30% in the beginning.

In other words, the saline water absorption rate of the biodegradable superabsorbent of the present invention is slightly low, but it was biodegraded at room temperature and turned yellow after 7 days, and was almost completely decomposed within 3 weeks. In contrast, it was confirmed that the synthetic superabsorbent had little change in shape or mass (Table 2).

Day 0 Day 7 Day 13 Day 20 Day 30 Synthetic superabsorbent, g 1.021 0.784 0.765 0.735 0.731 Synthetic superabsorbent, % 100.0 76.8 74.9 72.0 71.6 Biodegradable superabsorbent, g 0.985 0.538 0.162 0.122 0.062 Biodegradable superabsorbent, % 100.0 54.6 16.4 12.4 6.3

Claims (11)

(1) Crush and wash the shells or bones of marine crustaceans into pieces less than 10 cm in size, add them to 2-10% (w/v) sodium hydroxide solution, and heat at 80-100°C for 2-10 hours. removing proteins remaining in the shell or bones of marine crustaceans;
(2) The shell or bone of the marine crustacean from which the protein has been removed, obtained in step (1), is immersed in a 0.5 to 10% (v/v) acid solution and applied to the shell or bone of the marine crustacean. Removing calcium carbonate by reacting the contained calcium carbonate;
(3) After step (2), the process of step (2) is continued until the ash content of the shell or bone of the marine crustacean from which the calcium carbonate has been removed after removing the acid solution is 5% or less by weight. Repeating steps;
(4) 100 to 500 parts by weight of water, 50 to 150 parts by weight of a compound containing a phosphate group, and 100 to 300 parts by weight of urea based on 100 parts by weight of shell or bone of marine crustacean obtained in step (3). After adding the compound, reacting at 20-40°C for 3-9 hours, followed by washing and primary drying;
(5) heat-treating the first dried reactant in step (4) at 140-180°C for 10-100 minutes, washing the heat-treated reactant with a sodium hydroxide solution to gel it, and washing it with water to swell it;
(6) Fibrillating the reactant swollen in step (5) using a high-speed grinder, homogenizer, or super mass collidor so that the fibril width of the reactant is 3 nm to 3 ㎛. ;
(7) secondary drying of the fibrillated reactant obtained in step (6) at 30 to 100°C; and
(8) pulverizing the secondary dried reactant in step (7) and powdering it to a diameter of 10 to 3,000 ㎛. The method of claim 1, wherein in step (1), the shell or bone of marine crustacean is the shell of lobster, red crab, snow crab, king crab or shrimp, or the bone of cuttlefish. method. The natural biodegradable superabsorbent material according to claim 1, wherein in step (2), the acid solution is one of inorganic acids selected from the group consisting of acetic acid, sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid dissolved in water. Manufacturing method. The method of claim 1, wherein in step (4), the compound containing a phosphate group is any one selected from monobasic ammonium phosphate, dibasic ammonium phosphate ((NH ₄ ) ₂ HPO ₄ ), and sodium dihydrogen phosphate. A method for producing a natural biodegradable superabsorbent material. The method of claim 1, wherein in step (4), the urea-based compound is any one selected from urea, thio urea, and dimethyl urea. The method of claim 1, wherein in step (6), before fibrillation, CMC (carboxy methyl cellulose), citric acid, konjac, alginic acid, carrageenan, pentane, cyclopentane, and hexane. After adding one or more selected from hexane, cyclohexane, heptane, cycloheptane, butanol, and isobutanol, the swollen chitin is fibrillated. Method for producing a natural biodegradable superabsorbent. The method of claim 1, wherein between step (6) and step (7), oxidized starch, cationic starch, phosphate starch, carrageenan, A method for producing a natural biodegradable superabsorbent, further comprising adding 1 to 40 parts by weight of any one selected from konjac and alginic acid. The method of claim 1, between step (6) and step (7), with respect to 100 parts by weight of fibrillated chitin obtained in step (6), epichlorohydrin, glyoxal ( A method for producing a natural biodegradable superabsorbent, further comprising adding 1 to 10 parts by weight of one selected from glyoxal and maleic acid. The method of claim 1, wherein the primary drying in step (4) or the secondary drying in step (7) is drying by heat treatment; Solvent drying by adding any organic solvent selected from methanol, ethanol, isopropanol, butanol, acetone and toluene; Freeze-drying; and vacuum drying; A method for producing a natural biodegradable superabsorbent, characterized in that it is dried by any one selected from among. A sanitary product comprising a natural biodegradable superabsorbent manufactured by the manufacturing method of any one of claims 1 to 9. The sanitary product according to claim 10, wherein the sanitary product is one selected from the group consisting of baby diapers, adult diapers, panty liners, sanitary napkins, and tampons.