Barrier red algae fiber, method for producing the same, barrier coating paper containing the same, and barrier sheet

Abstract

The present invention relates to barrier red algae fibers, a method for producing the same, barrier coating paper and barrier sheets containing the same. The barrier coating paper according to the present invention not only has an excellent effect of preventing oxygen permeation and dewatering properties during the coating process compared to conventional wood-derived nanocellulose, but also has biodegradable properties, making it environmentally friendly.

Description

Technical Field

[0001] The present invention relates to barrier red algal fibers, and more particularly, to barrier red algal fibers, a method for producing the same, barrier coating paper containing the same, and barrier sheets.

Background Art

[0002] Ordinary "paper" is composed of woven pulp fibers and has many spaces, so oxygen, water vapor, etc. can easily pass through. That is, it does not have barrier properties that can suppress the permeation of moisture, oxygen, and other substances flowing in from the outside to the inside. Therefore, most of the packaging papers are barrier-coated, and mainly, the method of laminating polyethylene (PE) is most widely used, and latex coating is also considered. These materials are very excellent in terms of imparting moisture resistance, but since they are petrochemical carbon compounds, they are difficult to biodegrade and are not environmentally friendly. Therefore, it is urgently necessary to discover natural new materials that can replace petrochemical raw materials and expand their uses.

[0003] Therefore, many efforts have been made to obtain barrier properties imparted using petrochemical raw materials such as polyethylene from environmentally friendly materials. Cellulose nanofibrils (CNF), which are cellulose, the most representative environmentally friendly material, divided into the nanometer (nm) scale, are considered as a group of candidates to replace petrochemical raw materials and enhance the barrier properties of packaging materials. Cellulose nanofibrils are natural organic polymer substances that can be sustainably produced and are biodegradable. Generally, they have a width of less than 100 nm and a length reaching several micrometers. Such cellulose nanofibrils are known to have a very large aspect ratio, a high specific surface area, and excellent strength properties. In addition, cellulose nanofibrils can be easily manufactured into films by strong hydrogen bonds formed between the nanofibrils when dry. The cellulose nanofibril film can impart strong barrier properties against oxygen and liquids, etc., and is expected to be used as a material for enhancing environmentally friendly barrier properties in the field of packaging paper. However, the nanocellulose used so far is nanocellulose derived from wood, and since its water repellency is not excellent, it is an urgent need to discover a biodegradable barrier material with better water repellency and oxygen permeation prevention properties.

[0004] On the one hand, red algae are seaweeds with a red or purple tint because they contain phycoerythrin and phycocyanin in addition to chlorophyll. They inhabit relatively deeper waters than other algae, are relatively small in size, and are very diverse, with over 4,000 species. Red algae have a wider habitat range than green algae and brown algae, so they grow naturally from shallow water depths to deep water depths where light can reach. Red algae contain many fibers called root-like filaments among seaweeds. These fibers have a diameter of several microns and are almost of a constant size in all red algae. Also, red algae fibers are excellent in whiteness and opacity, and the binding ability between red algae fibers is also excellent. The crystallinity of red algae fibers is similar to that of cellulose fibers. In particular, the thermal properties of bleached red algae fibers are superior to those of cellulose fibers. Examples of red algae include nori, amakusa, obakusa, ushiotsume kusa, ogonori, ibaranori, igisu, amikusa, tambanori, tsukumonori, suginoori, egonori, and mukadenori. The internal gel extract of red algae is all utilized as food additives, health supplements, agar materials, etc.

[0005] Regarding barrier film-related technologies, Korean Patent Application Publication No. 1999-0034085 discloses a method for manufacturing a cellophane substitute film using carrageenan raw polymer and its composition, and Korean Patent No. 1770227 discloses a method for manufacturing a composition for an antifouling and moisture-proof barrier coating and a method for manufacturing an antifouling and moisture-proof barrier film using the same. However, there has been no disclosure so far regarding the barrier coating method using biodegradable seaweed fibers of the present invention, the barrier sheet containing seaweed fibers, and the paper coated with seaweed fibers.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention is derived from the requirements as described above, and an object of the present invention is to provide a barrier red algal fiber having excellent oxygen permeation prevention characteristics and dehydration properties during the coating process, a method for producing the same, a barrier coating paper containing the same, and a barrier sheet.

Means for Solving the Problems

[0008] In order to solve the above-described problems, the present invention provides a barrier red algal fiber containing elliptical red algal fibers having a major axis length of 50 to 500 μm in cross-section.

[0009] According to one aspect of the present invention, the elliptical red algal fiber may have a fiber wall thickness of 50 to 500 nm.

[0010] Further, the elliptical red algal fiber may be contained in an amount of 50% by weight or more of the total weight of the barrier red algal fiber.

[0011] Further, the barrier red algal fiber is formed through red algae, and the red algae may include any one or more of Eucheuma cottonii, Eucheuma spinosum, and Gracilaria.

[0012] Further, the present invention provides a method for producing a barrier red algal fiber, including: (1) adding 1000 to 3000 parts by weight of water to 100 parts by weight of a red algal mixture containing 0.1 to 5.0% by weight of sulfuric acid and 95 to 99.9% by weight of red algae, and then reacting at 60 to 120° C. for 1 to 5 hours to remove carrageenan or agar to obtain a residue of red algae; and (2) adding 400 to 600 parts by weight of water and 0.5 to 5.0 parts by weight of a bleaching substance to 100 parts by weight of the red algal residue obtained in step (1), adjusting the pH to 3 to 5, and then reacting at 60 to 95° C. for 0.5 to 5 hours to bleach and wash the red algal residue to obtain a barrier red algal fiber.

[0013] According to one aspect of the present invention, the bleaching substance may be any one or more of chlorine dioxide, sodium hypochlorite, chlorine, ozone, and oxygen.

[0014] The present invention also provides barrier-coated paper including paper and a barrier coating layer coated on at least a part of the surface of the paper and containing the above-described barrier red algae fibers.

[0015] According to one aspect of the present invention, the barrier coating layer may further contain a polymer, and the barrier coating layer may contain 10 to 99% by weight of the polymer and 1 to 90% by weight of the barrier red algae fibers.

[0016] The polymer may include one or more selected from PVA (Poly vinyl alcohol), starch, nanocellulose, chitin, PLLA (Poly-L-Lactic Acid), sc-PLA (Stereo Complex Polylactic Acid), PHB (Poly-(3-hydroxy buthyrate)), PBS (Poly Butylene Succinate), PCA (Poly caprolactone), and PGA (Poly glycolic acid).

[0017] The basis weight of the barrier coating layer may be 1 to 100 g / m 2 as well.

[0018] The barrier coating layer may further contain any one or more of PAM (Poly amidoamine), a wet paper strength enhancer, and a hydrophobizing agent.

[0019] The wet paper strength enhancer may include any one or more of an epoxy emulsion and epichlorohydrin, and the hydrophobizing agent may include any one or more of AKD (alkyl ketene dimer), ASA (alkenyl succinic acid), and rosin.

[0020] In addition, the present invention provides a barrier sheet containing the above-described barrier red algal fiber.

Effects of the Invention

[0021] The present invention is derived from the above-described requirements. The barrier red algal fiber according to the present invention, its production method, the barrier coating paper and the barrier sheet containing the same have an excellent effect in preventing oxygen permeation and dehydration during the coating process as compared with conventional wood-derived nanocellulose.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement it. The present invention can be embodied in various different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention, parts not related to the description in the drawings are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0024] The barrier red algal fiber according to the present invention is embodied to include elliptical red algal fibers.

[0025] At this time, as shown in FIG. 2, the elliptical red algal fiber has an elliptical shape.

[0026] Also, the length of the major axis of the cross-section of the elliptical red algal fiber is 50 to 500 μm, and preferably, the length of the major axis of the cross-section may be 60 to 450 μm. If the length of the major axis of the cross-section of the elliptical red algal fiber is less than 50 μm, the water removal property during the coating process may decrease. If the length of the major axis of the cross-section of the elliptical red algal fiber exceeds 500 μm, the oxygen permeation prevention property may decrease.

[0027] On the other hand, the term "major axis" used in the present invention refers to the axis having the longest length in the cross-section.

[0028] Also, the thickness of the fiber wall of the elliptical red algal fiber may be 50 to 500 nm, and preferably, the thickness of the fiber wall may be 60 to 450 nm. If the thickness of the fiber wall of the elliptical red algal fiber is less than 50 nm, the water removal property during the coating process may decrease. If the thickness of the fiber wall of the elliptical red algal fiber exceeds 500 nm, the oxygen permeation prevention property may decrease.

[0029] In addition, the elliptical red algal fiber may be contained in an amount of 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more of the total weight of the barrier red algal fiber. If the elliptical red algal fiber is contained in an amount of less than 50% by weight of the total weight of the barrier red algal fiber, the oxygen permeation prevention property and the water removal property during the coating process may be reduced.

[0030] In addition, the barrier red algal fiber according to the present invention comprises: (1) adding 1000 to 3000 parts by weight of water to 100 parts by weight of a red algal mixture containing 0.1 to 5.0% by weight of sulfuric acid and 95 to 99.9% by weight of red algae, and then reacting at 60 to 120°C for 1 to 5 hours to remove carrageenan or agar to obtain a red algal residue;

[0031] (2) adding 400 to 600 parts by weight of water and 0.5 to 5.0 parts by weight of a bleaching substance to 100 parts by weight of the red algal residue obtained in step (1), adjusting the pH to 3 to 5, and then reacting at 60 to 95°C for 0.5 to 5 hours to bleach and wash the red algal residue to obtain a barrier red algal fiber.

[0032] At this time, the red algae preferably includes, but is not limited to, any one or more of Eucheuma cottonii, Eucheuma spinosum, and Gracilaria.

[0033] In addition, the bleaching substance is preferably any one of chlorine dioxide, sodium hypochlorite, chlorine, ozone, and oxygen, more preferably chlorine dioxide or sodium hypochlorite, and even more preferably chlorine dioxide, which may be more advantageous for achieving the object of the present invention.

[0034] Furthermore, the present invention provides barrier-coated paper including paper and a barrier coating layer coated on at least a part of the surface of the paper and containing the above-described barrier red algae fibers.

[0035] At this time, the barrier coating layer can further contain a polymer, and the barrier coating layer can contain 10 to 99% by weight of the polymer and 1 to 90% by weight of the barrier red algae fibers. Satisfaction of the content ranges by the polymer and the barrier red algae fibers can be more advantageous for achieving the object of the present invention.

[0036] The polymer preferably includes, but is not limited to, one or more selected from PVA (Poly vinyl alcohol), starch, nanocellulose, chitin, PLLA (Poly-L-Lactic Acid), sc-PLA (Stereo Complex Polylactic Acid), PHB (Poly-(3-hydroxy buthyrate)), PBS (Poly Butylene Succinate), PCA (Poly caprolactone), and PGA (Poly glycolic acid).

[0037] On the other hand, the barrier coating layer can be formed by mixing the polymer and the barrier red algae fibers and coating the paper surface.

[0038] At this time, before mixing the polymer and the barrier red algae fibers, hydrogen peroxide and the barrier red algae fibers can be mixed to adjust the pH and then heat-treated to perform secondary bleaching.

[0039] At this time, the secondary bleaching can be performed by mixing 0.5 to 5.0% by weight of the hydrogen peroxide and 95 to 99.5% by weight of the barrier red algae fibers, the pH can be adjusted to pH 10 to 13, and the heat treatment can be performed at a temperature of 60 to 95°C for 0.5 to 5 hours.

[0040] On the other hand, the basis weight of the barrier coating layer is 1 to 100 g / m2 It may be.

[0041] In addition, the barrier coating layer may further contain any one or more of PAM (Poly amidoamine), wet paper strength enhancer, and hydrophobizing agent. The wet paper strength enhancer may contain any one or more of epoxy emulsion and epichlorohydrin, and the hydrophobizing agent may contain any one or more of AKD (alkyl ketene dimer), ASA (alkenyl succinic acid), and rosin, but is not limited thereto.

[0042] On the other hand, the present invention provides a barrier sheet containing the above-described barrier red algae fiber.

[0043] The barrier coating layer may be formed of the above-described barrier red algae fiber alone, or may be formed by including a predetermined polymer and the barrier red algae fiber.

[0044] According to an embodiment of the present invention, the barrier sheet may further contain a polymer. At this time, the barrier sheet may contain 10 to 99% by weight of the polymer and 1 to 90% by weight of the above-described barrier red algae fiber. It may be more advantageous for achieving the object of the present invention that the polymer and the barrier red algae fiber satisfy the above content range.

[0045] The polymer preferably contains one or more selected from PVA (Poly vinyl alcohol), starch, nanocellulose, chitin, PLLA (Poly-L-Lactic Acid), sc-PLA (Stereo Complex Polylactic Acid), PHB (Poly-(3-hydroxy buthyrate)), PBS (Poly Butylene Succinate), PCA (Poly caprolactone), and PGA (Poly glycolic acid), but is not limited thereto.

[0046] On the one hand, before mixing the polymer and the barrier red algal fiber, hydrogen peroxide and the barrier red algal fiber can be mixed to adjust the pH, and then heat-treated to perform secondary bleaching.

[0047] At this time, the secondary bleaching can be performed by mixing 0.5 to 5.0% by weight of the hydrogen peroxide and 95 to 99.5% by weight of the barrier red algal fiber. The pH can be adjusted to pH 10 to 13, and the heat treatment can be performed at a temperature of 60 to 95°C for 0.5 to 5 hours.

[0048] On the other hand, the basis weight of the barrier sheet may be 1 to 100 g / m 2 and it may be so.

[0049] In addition, the barrier sheet can further contain any one or more of PAM (Poly amidoamine), wet paper strength enhancer, and hydrophobizing agent. The wet paper strength enhancer can contain any one or more of epoxy emulsion and epichlorohydrin, and the hydrophobizing agent can contain any one or more of AKD (alkyl ketene dimer), ASA (alkenyl succinic acid), and rosin, but is not limited thereto.

[0050] <Mode for Carrying Out the Invention>

[0051] Hereinafter, the present invention will be described in more detail using examples. It is self-evident to those having ordinary knowledge in the technical field that these examples are merely for explaining the present invention more specifically, and the scope of the present invention is not limited thereby.

[0052] <Examples>

[0053] [Example 1-1. Production of Barrier Red Algal Fiber (Eucheuma cottonii Fiber)]

[0054] The Eucheuma cottonii fiber (barrier red algae fiber) was manufactured by the manufacturing method according to the flowchart disclosed in FIG. 1.

[0055] a. 300 g of dry Eucheuma cottonii, which is red algae fiber, was added to 6,000 g of water so that the weight ratio became 20:1 (water: Eucheuma cottonii). After that, 0.3 wt% of sulfuric acid was added based on the weight ratio of Eucheuma cottonii. Then, after raising the temperature for 30 minutes and reacting at 100 °C for 3 hours, the residue remaining after sufficiently extracting carrageenan using a 200-mesh screen was referred to as "Eucheuma cottonii residue (red algae residue)".

[0056] b. After adjusting so that the weight ratio of water: Eucheuma cottonii residue became 5:1, 2 wt% of chlorine dioxide based on the dry weight of Eucheuma cottonii residue was added and the pH was adjusted to 3.5 with acetic acid. Then, it was reacted at 90 °C for 1 hour and 30 minutes to bleach the Eucheuma cottonii residue, and the substance after washing was referred to as "Eucheuma cottonii fiber (barrier red algae fiber)".

[0057] In Example 1, from the XRD results and sugar analysis results of Eucheuma cottonii fiber, it was confirmed that Eucheuma cottonii is composed of cellulose (FIG. 3), and "cellulose fiber" can also be obtained from the solid content remaining after extracting agar from Gracilaria.

[0058] The manufactured barrier red algae fiber contained 80 wt% of elliptical red algae fibers whose major axis length of the cross section satisfied 50 to 500 μm and whose fiber wall thickness satisfied 50 to 500 nm.

[0059] [Example 1-2]

[0060] Manufactured in the same manner as in Example 1-1, but Eucheuma cottonii was changed to Gracilaria to produce barrier red algal fibers. The produced barrier red algal fibers contained 70% by weight of elliptical red algal fibers with the length of the major axis of the cross-section satisfying 50 to 500 μm and the thickness of the fiber wall satisfying 50 to 500 nm.

[0061] [Comparative Example 1-1]

[0062] Manufactured in the same manner as in Example 1-1, but Eucheuma cottonii was changed to Eucheuma spinosum to produce barrier red algal fibers. The produced barrier red algal fibers were cylindrical fibers with the length of the major axis being 500 to 800 μm and the thickness of the fiber being 1,000 to 2,200 nm.

[0063] [Comparative Example 1-2]

[0064] Hardwood bleached pulp was passed through a super masscolloidor 60 times at a concentration of 1.5% to produce nanocellulose. The obtained nanocellulose was cylindrical fibers with the major axis being 8.2 μm and the width of the fiber being 35.2 nm.

[0065] [Production of Barrier Sheets in Production Examples 1-1, 1-2 and Comparative Production Examples 1-1, 1-2]

[0066] Using the fibers produced in Example 1-1, Example 1-2, Comparative Example 1-1 and Comparative Example 1-2, a barrier sheet with a basis weight of 10 g / m 2 per square meter was produced on a cellulose acetate membrane (0.45 μm pore size, HYUNDAI MICRO, Republic of Korea) filter.

[0067] [Experimental Example 1: Analysis of Oxygen Permeability (OP) and Permeability]

[0068] The oxygen permeability of the barrier sheets prepared in Production Examples 1-1 and 1-2 and Comparative Production Examples 1-1 and 1-2 was measured. The measurement method of the oxygen transmission rate was carried out using an ultra-precision oxygen analyzer (OX-TRAN Model 2, MOCON, USA) at 23 degrees Celsius, 1 atmosphere, and 0 relative humidity for 24 hours. In order to correct for the thickness of the barrier sheet, the oxygen permeability was calculated by dividing the oxygen transmission rate by the sheet thickness.

[0069] Also, when manufacturing a barrier sheet with a basis weight of 5 g / m² on a cellulose acetate membrane (0.45 μm pore size, HYUNDAI MICRO, Republic of Korea) filter under the same vacuum pressure, the time required until dehydration no longer progresses was measured to analyze the dehydrability. 2 When manufacturing a barrier sheet with a basis weight of 5 g / m² on a cellulose acetate membrane (0.45 μm pore size, HYUNDAI MICRO, Republic of Korea) filter under the same vacuum pressure, the time required until dehydration no longer progresses was measured to analyze the dehydrability.

[0070] The results are shown in Table 1 below.

[0071]

Table 1

[0072] As shown in Table 1 above, Production Examples 1-1 and 1-2 that satisfy all of the major axis length, fiber wall thickness, and content of the elliptical red algal fibers of the present invention have a significantly lower oxygen permeability compared to Comparative Production Example 1-1 that uses cylindrical fibers exceeding the major axis length and fiber wall thickness range of the cross-section, and it can be confirmed that the dehydration time is significantly shorter compared to Comparative Production Example 1-2 that uses cylindrical fibers and is less than the major axis length and fiber wall thickness range of the cross-section.

[0073] [Production Example 2. Coating 5 g of Eucheuma cottonii fiber on the base paper]

[0074] After mixing 60% by weight of Yukeuma cotton fiber produced in Example 1-1 and 40% by weight of PVA (polyvinyl alcohol), on the coating base paper (coating base paper purchased from M Paper Company in South Korea, with a basis weight of 50 g / m 2 . Hereinafter, on the coating base paper), it was coated using a coating bar so that the weight of the coating layer was 5 g per square meter on a dry weight basis and then dried.

[0075] [Production Example 3. Coating of 10 g of Yukeuma cotton fiber on the coating base paper]

[0076] After mixing 60% by weight of Yukeuma cotton fiber produced in Example 1-1 and 40% by weight of PVA (polyvinyl alcohol), it was coated on the coating base paper using a coating bar so that the weight of the coating layer was 10 g per square meter on a dry weight basis and then dried.

[0077] [Comparative Production Example 2. Production of hardwood bleached pulp barrier sheet 1]

[0078] Hardwood bleached pulp was beaten using a valley beater until it reached 510 ml in the Canadian standard freeness test, and a barrier sheet of 20 g per square meter was produced in the same manner as in Production Example 1-1.

[0079] [Comparative Production Example 3. Production of hardwood bleached pulp barrier sheet 2]

[0080] Hardwood bleached pulp was beaten using a valley beater until it reached 95 ml in the Canadian standard freeness test, and a barrier sheet of 20 g per square meter was produced in the same manner as in Production Example 1-1.

[0081] [Comparative Production Example 4. Production of microfibril and nanocellulose]

[0082] Using the beaten hardwood fibers of Comparative Production Example 3, and additionally beating them 20 times using a super mass colloidor, cellulose microfibrils (CMF) in the form of cylinders with a fibril length of 25.5 μm and an average fibril width of 185 nm were produced.

[0083] Also, using the beaten hardwood fibers of Comparative Production Example 3, and additionally beating them 60 times using a supermasscolloidor, cellulose nano-fibrils (CNF) in the form of cylinders with a fibril length of 7.6 μm and an average fibril width of 45 nm were produced.

[0084] [Manufacturing a barrier sheet of 10 g per square meter using Comparative Production Example 5.CMF]

[0085] A barrier sheet of 10 g per square meter was manufactured on a nanofilter using the CMF produced in Comparative Production Example 4.

[0086] [Manufacturing a barrier sheet of 10 g per square meter using Comparative Production Example 6.CNF]

[0087] A barrier sheet of 10 g per square meter was manufactured on a nanofilter using the CNF produced in Comparative Production Example 4.

[0088] [Comparative Production Example 7. Coating the base paper with 10 g of CMF]

[0089] After mixing 60% by weight of the dried CMF produced in Comparative Production Example 4 and 40% by weight of PVA (polyvinyl alcohol), it was coated on the coating base paper using a coating bar so that the weight of the coating layer was 10 g per square meter on a dry weight basis, and then dried.

[0090] [Comparative Production Example 8. Coating the base paper with 10 g of CNF]

[0091] After mixing 60% by weight of the dried CNF produced in Comparative Production Example 4 and 40% by weight of PVA (polyvinyl alcohol), it was coated on a base paper for coating using a coating bar so that the weight of the coating layer was 10 g per square meter on a dry basis and then dried.

[0092] [Comparative Production Example 9. Production of Film]

[0093] Using an extruder (Multi-Layer T-die Extrusion Film Production Line, Hankook EM, Korea), after heating PLA (stereoisomers of 1.2 - 1.6% D-isomer lactide (PLA-4032D) and an average molecular weight of 220 kDa) under the conditions of 160 - 180°C, a film of 10 g per square meter was produced.

[0094] [Comparative Production Example 10. Base Paper for Coating]

[0095] A base paper for coating of 50 g per square meter was purchased from Company M in the Republic of Korea and used.

[0096] [Experimental Example 2. Analysis of Oxygen Permeability (OP)]

[0097] The components of Production Examples 1-1, 2, 3 and Comparative Production Examples 2 - 10 and their oxygen permeabilities were measured (measured by the oxygen permeability measurement method of Experimental Example 1).

[0098] The results of the oxygen permeability (OP) of the films are disclosed in Table 2. The oxygen permeability of PVDC (polyvinylidene chloride), which is a polymer barrier film with excellent oxygen permeability, is 10 - 300 cm 3 ·μm / m 2 ​When considering the aspect of being a ·day·atm, biodegradable Yukeuma cotton fiber (Production Example 1-1) and CNF (Comparative Production Example 6) were judged to be able to serve as very excellent oxygen gas barriers. In comparison, the barrier sheets of hardwood fibers (Comparative Production Examples 2 and 3) with a large amount of beating and the PLA (Comparative Production Example 9) film had very high oxygen permeability, and it was confirmed that CMF (Comparative Production Example 5) also did not serve as an excellent barrier.

[0099]

Table 2

[0100] In Table 3, when Yukeuma cotton fiber (Production Example 3) and CNF were coated on the coating base paper (Comparative Production Example 8) at 10 g / m 2 per square meter, it was confirmed that they could serve as excellent oxygen barriers similar to the PVDC film. However, when Yukeuma cotton fiber was coated in a small amount, as in Production Example 2, it showed a slightly higher oxygen permeability than PVDC. In comparison, CMF (Comparative Production Example 7) still showed a significantly higher oxygen permeability than PVDC.

[0101] Oxygen permeability after coating on the coating base paper at 50 g per square meter

Table 3

[0102] As described above, it was confirmed that Yukeuma cotton fiber and CNF could serve as excellent oxygen barriers. However, in order to produce CNF, not only must bleached wood pulp be produced first, but also a large amount of energy must be applied to produce nanocellulose. In comparison, Yukeuma cotton fiber has the advantage of requiring less energy because it can be produced with only a simple bleaching treatment process.

[0103] [Experimental Example 3. Analysis of Dehydration]

[0104] In order to apply biodegradable films or coating substances to packaging materials, water must be used as a medium. However, when the dehydration rate of the water used as the medium is delayed, not only does the production speed slow down during film production, but it is also difficult to coat at a high concentration during coating. Therefore, it was confirmed whether the dehydration property is excellent or not.

[0105] The dehydration experiment was carried out on a cellulose acetate membrane (0.45 μm pore size, HYUNDAI MICRO, Republic of Korea) filter with a barrier sheet having a basis weight of 5 g / m 2 When manufacturing a barrier sheet with the same basis weight under the same vacuum pressure, it was measured by the time required until no further dehydration progresses.

[0106] When the results of the analysis of dehydration property were disclosed in Table 4, CMF (Comparative Production Example 5) or CNF (Comparative Production Example 6) has a very slow dehydration rate, so it is very likely that problems will occur in product production unless special equipment is used or a large amount of drying energy is used.

[0107] On the other hand, it was confirmed that eucalyptus cotton fiber has a dehydration property to the extent that hardwood pulp is beaten a lot, so it can be manufactured using a paper machine as it is with high productivity and low drying energy.

[0108] Dehydration Characteristics of Biodegradable Barrier Raw Material Substances

Table 4

[0109] Although one embodiment of the present invention has been described, the idea of the present invention is not limited by the embodiments presented in this specification. Those skilled in the art who understand the idea of the present invention will be able to easily propose other embodiments by adding, changing, deleting, adding, etc. components within the scope of the same idea, and this can also be said to be included within the scope of the idea of the present invention.

Claims

Claim 1 A barrier red algal fiber, comprising an elliptical red algal fiber having a major axis length of the cross-section of 50 to 500 μm. Claim 2 The barrier red algal fiber according to claim 1, wherein the elliptical red algal fiber has a fiber wall thickness of 50 to 500 nm. Claim 3 The barrier red algal fiber according to claim 1, wherein the elliptical red algal fiber is contained in an amount of 50% by weight or more of the total weight of the barrier red algal fiber. Claim 4 The barrier red algal fiber according to claim 1, wherein the barrier red algal fiber is formed through red algae, and the red algae includes any one or more of Eucheuma cottonii, Eucheuma spinosum, and Gracilaria. Claim 5 (1) After adding 1000 to 3000 parts by weight of water to 100 parts by weight of a mixture of 0.1 to 5.0% by weight of sulfuric acid and 95 to 99.9% by weight of red algae, reacting at 60 to 120°C for 1 to 5 hours to remove carrageenan or agar to obtain a residue of red algae remaining, and (2) Adding 400 to 600 parts by weight of water and 0.5 to 5.0 parts by weight of a bleaching substance to 100 parts by weight of the red algal residue obtained in step (1), adjusting the pH to 3 to 5, and then reacting at 60 to 95°C for 0.5 to 5 hours to bleach and wash the red algal residue to obtain a barrier red algal fiber; A method for producing a barrier red algal fiber, characterized by comprising the steps. Claim 6 The method for producing a barrier red algal fiber according to claim 5, wherein the bleaching substance is any one or more of chlorine dioxide, sodium hypochlorite, chlorine, ozone, and oxygen. Claim 7 Paper, and A barrier coating paper, characterized by comprising a barrier coating layer coated on at least a part of the surface of the paper and containing the barrier red algal fiber according to any one of claims 1 to 4. Claim 8 The barrier coating layer further contains a polymer, The barrier coating paper according to claim 7, wherein the barrier coating layer contains 10 to 99% by weight of the polymer and 1 to 90% by weight of the barrier red algal fiber. Claim 9 The polymer described above contains one or more selected from PVA (Poly vinyl alcohol), starch, nanocellulose, chitin, PLLA (Poly-L-Lactic Acid), sc-PLA (Stereo Complex Polylactic Acid), PHB (Poly-(3-hydroxy butyrate)), PBS (Poly Butylene Succinate), PCA (Poly caprolactone), and PGA (Poly glycolic acid). The barrier coating paper according to claim 8 is characterized by this.

10. The barrier coating layer has a basis weight of 1 to 100 g / m ２ The barrier coating paper according to claim 7, characterized in that it is so.

11. The barrier coating layer further contains any one or more of PAM (Poly amidoamine), wet paper strength enhancer, and hydrophobizing agent. The barrier coating paper according to claim 7 is characterized by this.

12. The wet paper strength enhancer contains any one or more of epoxy emulsion and epichlorohydrin, and the hydrophobizing agent contains any one or more of AKD (alkyl ketene dimer), ASA (alkenyl succinic acid), and rosin. The barrier coating paper according to claim 11 is characterized by this.

13. A barrier sheet, characterized by containing the barrier red algae fiber according to any one of claims 1 to 4.

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