KR100811194B1 - Method for Preparing a Pulp Having High Content of Inner Gel Extract from Rhodophyta - Google Patents

Abstract

The present invention relates to a method for preparing pulp having a high content of internal gel extract from red algae, and more particularly, after removing impurities of red algae, washing with water and dehydrating the dehydrated red algae with reducing water, basic medicine and reducing agent. After extracting the gel by immersing at a predetermined time and a predetermined temperature in the extraction solvent selected from the group consisting of, the residue is collected and converted into fibers, and then relates to a red algae pulp manufacturing method comprising the step of bleaching the fibers.

According to the present invention, since the gel is extracted using a basic extraction solvent, it is possible to obtain a gel extract having a higher viscosity than when extracted with water, thereby producing a pulp having a high content of the internal gel extract, It is possible to make paper with high transparency and high density with the pulp. In addition, when the reducing agent is used as the extraction solvent, pulp can be produced with a high content of the extraction of gels inside the hemp while maintaining a bright color without burdening bleaching even at high temperatures. It has an effect.

Red algae, pulp, extractant, basic, reducing agent

Description

Method for Preparing a Pulp Having High Content of Inner Gel Extract from Rhodophyta}

1 is a view showing the extraction process of red algae using reduced water and basic chemicals.

2 is a view showing the bleaching process of red algae completed the extraction process.

Figure 3 is a diagram showing the extraction process of red algae using a reducing agent.

The present invention relates to a method for preparing pulp having a high content of internal gel extract from red algae, and more particularly, after removing impurities of red algae, washing with water and dehydrating the dehydrated red algae with reducing water, basic medicine and reducing agent. The present invention relates to a method for producing red algae pulp, which comprises the step of immersing a gel in an extraction solvent selected from the group consisting of: extracting the gel, converting the residue into fibers, and bleaching the fibers.

Generally, fibers obtained by mechanically or chemically treating a plant raw material are called pulp. In fact, in addition to wood, cotton, hemp, flax, jute, german hemp, manila hemp, cedar, bamboo, straw, esparto, bamboo, bagasse, etc., are used as pulp raw materials. However, the requirements to be provided as industrial raw materials should be abundant in quantity, easy to collect, transport and store, inexpensive and excellent in quality.

Wood, which is a major pulp feed material, is mainly composed of cellulose, hemicellulose, and lignin, and these components constitute the cell wall and the intercellular layer and are present in more than 90% of all species. Subcomponents include resins, essential oils, fats and oils, extracts such as tannins and flavonoids, and other inorganic substances. Among them, cellulose is present in the largest amount of organic compounds present in nature, and is the main component of the plant cell wall. Cellulose is a polymeric material that is insoluble in water, dilute acids and alkalis at room temperature. In order to industrially use wood cellulose, it is used as wood sugar by manufacturing paper through hydrolysis, bleaching, refining, etc., or by hydrolyzing wood, and making and using cellulose derivatives through various chemical treatments. Doing. Various operations are performed from the raw material to the pulp, but it can be largely classified into preparation of pulp raw material, pulping, and purification of pulp.

In the process of processing a wood raw material in the state which is easy to pulp, there are operations, such as cutting, peeling, and sorting, and this is performed suitably according to the kind of raw material. The process of obtaining fibers from the raw material after the preparation process is called a pulping process and is the most important process in pulp production. Fibers can be obtained by destroying the composite intercellular layer of wood, which is a pulp material, with a wood mill or by softening it with water vapor and then breaking it using physical force. The pulp obtained by simple mechanical treatment without chemical treatment is called mechanical pulp. Mechanical pulp has high yield and low production cost, but it is not suitable as a raw material of high grade paper because of high lignin content.

Treatment of the pulp feedstock with ligignin chemicals dissolves the complex intercellular layer and dissociates it into fibrous form. Pulp prepared in this way is called chemical pulp. In the manufacture of chemical pulp, not only the lignin in the intercellular layer of the raw material, but also most of the membrane lignin is removed, and at the same time, many hemicelluloses are dissolved and some cellulose is degraded. Chemical pulp has high quality, i.e., high purity of cellulose, but has a disadvantage of low yield and high production cost compared to mechanical pulp. Chemical pulp production methods include sulfurous acid method, soda method and sulfate method. The selection process is a process of washing and screening fibers obtained from the raw material after the pulping process to remove parts and contaminants that are not completely pulped, and then bleaching as necessary. Specific refinement treatments are performed for those requiring high quality, such as rayon pulp.

The above is the description about the general process of manufacturing pulp from wood raw materials. However, as the depletion of wood resources around the world becomes severe, the task of the industry is to produce paper stock pulp while protecting forests and the environment. As a solution to this problem, a technique for producing paper pulp from non-woody plant fiber mainly on first and second year plants has received attention.

Non-woody plants that can be used as a raw material for papermaking include bark, flax, hemp, cotton, manila hemp, rice straw, bagasse and the like. In general, non-woody plants are high in pectin, hemicellulose, minerals, low in lignin, and chemical, semi-chemical, and mechanochemical methods are used when pulping, with very mild conditions compared to wood. Unbleached or bleached pulp can be obtained.

Non-wood pulp has different properties depending on its fiber type, chemical composition, and the type and amount of non-fibrous cells. Therefore, the paper made by non-wood pulp alone or by proper blending with wood pulp can easily control the strength, durability, electrical characteristics, gloss, dimensional stability and printing performance, which can be used for various purposes. Therefore, the use range is also wide. However, the conventional non-wood pulp has to go through a difficult process, and there is a problem that the environment is polluted because toxic chemicals are used even when producing pulp.

Accordingly, the present inventors have introduced a pulp and paper manufacturing method using the red alga in the "pulp and paper made with red algae and the manufacturing method thereof" of the application No. 10-2004-0092297. When pulp and paper are manufactured using red algae, production costs are very low, and the use of chemicals for lignin removal and bleaching is significantly reduced, thereby preventing environmental pollution. However, the present invention uses only extraction solvents of water, ethyl alcohol, methyl alcohol, acetone and ketones, and this alone has limitations in preparing various pulp for the desired purpose.

Therefore, the present inventors have continued to study the pulp manufacturing method, as a result of developing a red algae extraction process for producing pulp, and extracted with a basic extraction solvent, has a higher viscosity than when extracted with water A gel extract can be obtained, and the pulp prepared therefrom has a high internal gel extract content, has high transparency, and is a fiber capable of making a dense paper, thereby completing the present invention.

After all, an object of the present invention is to remove impurities of red algae, and then dehydrate after washing with water, and the dehydrated red algae is immersed in an extraction solvent selected from the group consisting of reduced water, basic chemicals and reducing agents for a predetermined time and for a predetermined time. After the extraction, the residue is collected and converted to fibers, and then to provide a red algae pulp manufacturing method comprising the step of bleaching the fibers.

In order to achieve the above object, the present invention comprises the steps of (a) removing impurities of red algae, washing with water and dehydrating; (b) extracting the gel by immersing the dehydrated red alga in a predetermined time and a predetermined temperature in an extraction solvent selected from the group consisting of reducing water, a basic drug and a reducing agent; (c) collecting the extracted gels and residues and converting them into fibers; And (d) provides a method for producing a pulp having a high internal gel extract content from red algae comprising bleaching the fibers.

In the present invention, the red algae may be any one or more selected from the group consisting of Locust spruce, Dolphin spree, gambling spruce and Noodle sprouts tree, but includes all red algae in which minimal fibers are present. On the other hand, the basic drug may be characterized in that any one or more selected from the group consisting of sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca (OH) ₂ ) and ammonia (NH ₃ ), the reducing agent Is hydrosulfite (Na ₂ O ₄ S ₂ ), sodium thiosulfate (Na ₂ S ₂ O ₃ ), sodium borohydride (NaBH ₄ ), sodium formaldehyde sulfoxylate (NaHSO ₂ · CH ₂ O · 2H ₂ O It may be characterized in that any one or more selected from the group consisting of.

In the present invention, the extraction temperature of step (b) may be characterized in that 60 ~ 200 ℃.

The present invention also provides a method for producing a highly transparent and dense paper, characterized in that the red algae pulp with high internal gel extract content and the red algae pulp with high internal gel extract content are processed.

Hereinafter, the present invention will be described in detail.

1. Raw material of the present invention: red algae

Red algae inhabit relatively deeper water than other algae, and are relatively small in size, with more than 4000 species. Red algae have a wider range of habitat than green algae and brown algae, and grow from shallow depths to deep water rays.

On the other hand, agar is a product that is processed through the process of freezing, thawing, drying by extracting the complex polysaccharide, a cell wall component of red algae with hot water. Red algae, which are widely used as raw materials of agar, include wood starfish, ox radish, buckwheat, stalks, thorn radish, silk grass, scabbard, stone starfish, stone and Jinuaari. Agar is largely composed of agarose and agalopectin 7: 3. These ingredients become the active ingredient of agar. Agarose, a neutral polysaccharide, has a property of increasing gel strength due to its strong gelling property, and agalopectin, an acidic polysaccharide, has a property of improving viscoelasticity instead of weak gel. Representative properties of agar include coagulation, viscoelasticity and water retention. Because agar has the opposite properties of coagulation and viscoelasticity, it can be used as a stabilizer, extender, forming agent, thickening agent, drying inhibitor, or physical property maintaining agent by controlling two physical properties.

In addition, the agar solution shows stronger gelling properties than any other gel forming agent. Agar solution forms a gel at 32 ~ 43 ℃, once formed gel does not melt below 80 ~ 85 ℃, even if repeated gelling and dissolution is characterized by little change in the original gel properties. Transparent gels are easy to color, and the addition of sugar, glucose, glycerin, etc. increases the refractive index and makes it glossy.

The raw material according to the present invention may be any one or more selected from the group consisting of Locust spruce tree, Dolphin spruce tree, gambling tree and Noodle sprout tree, but includes all red algae in which minimal fiber is present. It is also possible to use carrageenan or agar obtained from red algae.

Usually, agar extracted from hot water or stalks has a stronger strength than carrageenan extracted from hot water from Kotoni or Spino Island, and agar components extracted from hot water have a higher strength than agar extracted from hot water. Carrageenan, which is included in red algae such as kotoni and spino island, exhibits the same properties in that it contains fibers that can be made into pulp as compared to gels contained in red algae such as wood starfish and stalks. Therefore, in the present invention, agar components contained in red algae, such as carrageenan, wood starfish and stalks, included in red algae, such as kotoni and spino island, will be collectively referred to as 'gel'.

2. Preparation of Pulp

2-1 Extraction of Red Algae

Red algae such as wood, stone, gambling and noodles are immersed in an aqueous alkali solution such as potassium hydroxide (KOH) for a certain period of time, washed with water and dehydrated. At this time, through the process of immersing the red algae in an aqueous alkali solution for a certain time, the red algae is slightly discolored and impurities are removed. At this time, bleaching red algae helps in the subsequent bleaching process. If you have a lot of calcium carbonate in red algae, dilute hydrochloric acid or acetic acid can be added to dissolve the calcium carbonate.

When the washed and dehydrated red alga is immersed in the extraction solvent of the present invention, the gel contained in the red alga is extracted with the extraction solvent. The extraction solvent for extracting the gel may be used as long as it is a substance capable of dissolving the gel, such as water, an alcohol solvent such as ethyl alcohol or methyl alcohol, and a ketone solvent such as acetone. In the process, reducing water is used or basic chemicals, such as sodium hydroxide, calcium hydroxide, potassium hydroxide, etc. are adjusted to pH 7.5 or more, and the temperature is reacted in a pressure tank at 60 ~ 200 ℃, an effective extraction process proceeds. By using reduced water, basic chemicals, and reducing agents as extraction solvents, gel extracts of higher viscosity can be prepared than when using water, alcohol solvents such as ethyl alcohol or methyl alcohol, ketones such as acetone, and the like.

2-2 Bleaching Process

2, the red algae material subjected to the extraction process of the above 2-1 into ozone (O ₃₎ times (1hr / 1 times) bleaching, and twice at 60 ℃ with ClO ₂ (1.5hr / 1 times), and then bleached, 80 ℃ Bleach with H ₂ O ₂ twice (1hr / 1). After that, the fiber can be manufactured through a fiber classification process.

3. Papermaking Process

In general, "paper" refers to a cellulose fiber in the form of a sheet so that it can be used for printing, writing, packaging, etc., and manufacturing paper suitable for the purpose by various treatments is called "paper". The paper making process, or paper making process, varies slightly depending on the purpose of the paper, which is the final product.

3-1 Confession

If the pulp produced in the pulp mill is made of paper without any processing, the paper is hard to use for general purposes such as weak strength, rough surface and excessive air permeability. This is because the fibers of natural pulp are rigid and have a low surface area, which causes the fibers to hardly bond.

Therefore, the fibers must be mechanically treated in water to make them suitable for papermaking. This process is called beating. Breaking of the fiber is called free beating, and when fibrillation occurs mainly, it is called wet beating. By beating, the fiber outer layer is removed, internal fibrillation occurs, the fiber length is cut, microfibers are formed, and partial dissolution of the chemical composition occurs. The beating makes the fiber flexible and increases the bonds between the fibers, so that as the altitude rises, the paper has a dense structure.

3-2 Sizing

It is a process of imparting resistance to ink or water to paper, and the chemical used at this time is called sizing agent. There are two types of sizing, surface sizing and internal sizing.

3-3 charge

Minerals such as clay or calcium carbonate are incorporated into pulp during papermaking. Increase paper opacity, printability and basis weight.

3-4 Screening and Selection

Before sending the paper to the paper machine, it is a process to remove the contaminants mixed in the paper so that the properties of the paper are made constant.

3-5 grassland

After forming a web on a wire from a pulp, a sizing agent, a filler, various additives, and the like, a paper is pressed, dehydrated, and dried to make paper. According to the method of forming the paper on the wire, the paper machine is divided into a long mesh, a circular mesh, and a twin mesh.

3-6 processing

Processing is a step of performing various processing such as coating, modification, absorption, lamination, etc., using the produced paper as a base paper. In the papermaking method according to the present invention, because the red algae rather than wood pulp is used as a raw material, the beating process is not essential, but it is preferable to go through the beating process when using the aid. If you use high-purity agar products, you do not have to perform confession separately.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

Example 1 Extraction Process Using Reduced Water and Basic Chemicals

By varying the pH of the extraction solution, changes in yield and paper properties were investigated. As described in Figure 1, the extraction solution was used for water, reduced water and sodium hydroxide (NaOH), each raw material was tested by diluting 20 times with water. As a raw material, red algae, Gelidium Chilense , was used. When extracting Gelidium Chilense , a red algae using water, at 130 ° C. for 2 hours, 56% of the gel extracts could be eluted, and 56% of reduced water and 58 at pH 11 of sodium hydroxide solution. % Gel extracts could be eluted respectively. When extracted with reduced water and basic chemicals, it was found that the viscosity of the eluted gel extract was very increased. After the extraction process was completed, a bleaching process as shown in FIG. 3 was performed, and the yield and paper properties at that time are shown in Table 1 and Table 2, respectively. Table 1 shows the yield change according to the extraction conditions, Table 2 shows the change in the characteristics of the paper according to the extraction conditions. When extracted with reduced water or basic chemicals, it had similar whiteness and tensile strength under the same bleaching conditions as the residues remaining after extraction with water, and as shown in Table 1, the total yield of pulp was reduced water or basic than that extracted with water. When extracted using a chemical, but slightly increased, the pulp prepared in this way can be made transparent or translucent paper, unlike the general wood chemical pulp when the paper is made with a considerable amount of gel extract remaining inside The paper was found to be dense.

          Process samples Raw material Extraction process yield O ₃ bleaching ClO ₂ Bleaching H ₂ O ₂ Bleaching Water pH (7.0) 100 44.20 42.17 29.33 13.92 Reducing Water pH (7.8) 100 48.72 45.87 32.22 14.52 NaOH pH (11.3) 100 46.70 44.12 30.99 15.45

Sample Basis weight (g / m ² ) Density (g / ml) Thermal insulation (Km) Elongation (%) Burst Index (Kpa / g / m ² ) Tear index (mNm ² / g) Whiteness (%) Smoothness (sec) Internal theft water 60.38 0.65 4.64 2.21 1.51 3.20 74.03 41.58 11.67 Reduced water 53.17 0.71 4.28 1.66 1.66 2.68 69.04 54.50 7.00 NaOH 65.83 0.69 3.70 1.49 1.74 3.30 68.73 69.28 4.87

Example 2 Extraction Process Using Reducing Agent

Na ₂ S ₂ O ₄ was used as the extraction solution, and the extraction temperature was changed, and the yield change and the paper property change according to the extraction conditions were investigated. As shown in FIG. 2, the extraction temperature was 110 ° C., 130 ° C., and 150 ° C., and the experiment was performed by diluting Na ₂ S ₂ O ₄ with water 20 times. As a raw material, red algae, Gelidium Chilense , was used. After the extraction process was completed, the bleaching process as shown in FIG. 3 was performed. The yield and the properties of the paper at that time are shown in Tables 4 and 5, respectively. Table 5 shows the yield change according to the extraction conditions, Table 6 shows the change in the characteristics of the paper according to the extraction conditions. When extracted with a reducing agent, it had similar whiteness and tensile strength under the same bleaching conditions as the residues remaining after extraction with water. As shown in Table 3, the total yield of pulp was lower than that extracted with water, and the same extraction solvent was used. In this case, the lower the temperature, the lower the content, the higher the extraction yield was found. Therefore, it can be seen that by controlling the concentration and temperature of the reducing agent it can be made a paper of the desired strength and type.

Na ₂ S ₂ O ₄ Raw material Extraction process yield O ₃ bleaching ClO ₂ Bleaching H ₂ O ₂ Bleaching 110 ℃, 1% 100 48.38 40.56 16.48 15.4 110 ℃, 3% 100 45.96 36.38 19.51 13.2 130 ℃, (water) 100 44.20 42.17 29.33 13.9 130 ℃, 1% 100 40.92 27.51 13.88 13.2 130 ℃, 3% 100 40.11 28.53 15.97 12.7 150 ℃, 3% 100 33.86 23.03 13.87 12.8

Sample Basis weight (g / m ² ) Density (g / ml) Thermal insulation (Km) Elongation (%) Burst Index (Kpa / g / m ² ) Tear index (mNm ² / g) Whiteness (%) Smoothness (sec) Internal theft 110 ℃ One% 67.3 0.73 5.43 1.47 2.09 2.97 73.90 61.03 4 3% 67.8 0.73 4.84 1.50 1.88 2.21 77.23 46.78 3 130 ℃ water 60.38 0.65 4.64 2.21 1.51 3.20 74.03 41.58 12 One% 62.33 0.72 6.24 2.71 2.36 3.32 74.95 38.18 14 3% 63.00 0.72 5.53 2.56 1.87 3.28 78.23 52.33 20 150 ℃, 3% 60.67 0.70 3.97 1.72 1.90 2.72 74.73 39.30 8

Example 3 High Density Paper Made of Fiber Extracted with Reducing Agent and Basic Chemicals

An example of making high density paper using fibers extracted with NaOH in Example 1 is shown in Table 5. Considering that the opacity of the general tracing paper is about 30%, it can be seen that a relatively transparent paper can be produced through the above process.

As described above in detail the specific parts of the present invention, for those of ordinary skill in the art, these specific descriptions are only preferred embodiments, which are not intended to limit the scope of the present invention. Will be obvious. Therefore, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Basis weight (g / m ² ) Density (g / ml) Thermal insulation (Km) Opacity (%) Elongation (%) High density paper 1 76.6 1.04 5.32 28.2 1.63 High density paper 2 71.3 0.82 5.92 26.2 1.13 High Density Paper 3 73.6 0.93 5.75 26.9 1.26

According to the method for preparing pulp according to the present invention, the main raw material is to use red algae rather than wood, so that pulp and paper can be produced at low cost, and compared with the process for producing wood pulp for lignin removal and bleaching. The use of chemicals is significantly reduced, reducing the risk of environmental pollution. In addition, since the gel is extracted using a basic extraction solvent, it is possible to obtain a gel extract having a higher viscosity than when extracted with water, thereby preparing a pulp having a high content of the internal gel extract, and the pulp has a high transparency. It has the characteristics that can manufacture a high density paper. In addition, when the reducing agent is used as the extraction solvent, it is possible to produce a pulp according to the desired purpose by adjusting the temperature and concentration of each, there is an advantage that can produce paper with different characteristics.

Claims (8)

Method for producing pulp with high internal gel extract content from red algae comprising the following steps: (a) immersing red alga in an aqueous alkali solution for a certain time, followed by washing with water and dehydrating; (b) extracting the gel by immersing the dehydrated red alga in a predetermined temperature at a predetermined temperature in an extraction solvent selected from the group consisting of reducing water, a basic drug and a reducing agent; (c) collecting the residue from the gel extract extracted in step (b) and converting it to fibers; And (d) bleaching the fibers. The method of claim 1, wherein the red algae is any one or more selected from the group consisting of Locust spruce tree, Dolphin spree, Gambling tree and Noodle sprouts tree. The pulp according to claim 1, wherein the basic medicine is at least one selected from the group consisting of sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca (OH) ₂ ), and ammonia (NH ₃ ). Manufacturing method. The method of claim 1, wherein the reducing agent is hydrosulfite (Na ₂ O ₄ S ₂ ), sodium thiosulfate (Na ₂ S ₂ O ₃ ), sodium borohydride (NaBH ₄ ), sodium formaldehyde sulfoxylate (NaHSO ₂ And at least one selected from the group consisting of CH ₂ O. 2H ₂ O). The method of claim 1, further comprising curing the fiber prior to step (d). The method of claim 1, wherein the extraction temperature of step (b) is pulp manufacturing method, characterized in that 60 ~ 200 ℃. Red algae pulp having a high content of internal gel extract prepared by the method of any one of claims 1 to 6. A process for producing a high transparency and high density paper, characterized in that the processing of red algae pulp with a high content of the internal gel extract of claim 7.

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