KR20070040553A - Method for preparing pulp using rhodophyta having thin cortex - Google Patents

Abstract

The present invention relates to a pulp manufacturing method using a thin skinned red algae, and more specifically, a thin skinned red algae is immersed in an acidic solution for a predetermined time, washed with water and then dehydrated, and the dehydrated red algae is bleached in multiple stages. After the treatment, the bleached red algae are collected and fiberized to produce a red algae pulp.

According to the pulp manufacturing method using the red algae of the present invention, it is possible to produce pulp with high whiteness only by bleaching process, without going through a separate extraction process, and the chemicals used during the bleaching process are also compared to the conventionally used chemicals. It has the advantage of being environmentally friendly.

Red algae, pulp, bleach

Description

Method for preparing pulp using thin red algae {Method for Preparing Pulp Using Rhodophyta Having Thin Cortex}

1 is a diagram showing the bleaching pulp process of red algae.

The present invention relates to a pulp manufacturing method using a thin skinned red algae, and more specifically, a thin skinned red algae is immersed in an acidic solution for a predetermined time, washed with water and then dehydrated, and the dehydrated red algae is bleached in multiple stages. After the treatment, the present invention relates to a method for producing red algae pulp, which collects and bleaches the bleached red algae.

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, gingko, straw, esparto, bamboo and bagasse are used as pulp feedstocks. 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 a high yield and low production cost, but it is not suitable as a raw material of high grade paper because of its high content of lignin.

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 fibers mainly on first and second year plants has attracted 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 invention has been described only for the method of preparing pulp through the extraction process of water, ethyl alcohol, methyl alcohol, acetone and ketones, and the bleaching process has not been described in detail. There was a limit to increasing the whiteness of paper.

Accordingly, the present inventors have continued research on the pulp manufacturing method, and as a result, developed a bleaching process of red algae for producing pulp, and only the bleaching process of the present invention does not need to go through a separate extraction process, high whiteness It was found that pulp can be prepared and the present invention was completed.

After all, an object of the present invention is to immerse a thin shelled red algae in an acidic solution for a predetermined time, and then dehydrate after washing with water, and bleaching the dehydrated red algae in multiple stages, and then collecting and bleaching the bleached red algae. To provide a method for producing red algae pulp.

In order to achieve the above object, the present invention comprises the steps of (a) immersing a thin shelled algae in an acidic solution for a predetermined time, followed by washing with water and dehydrating; (b) bleaching the dehydrated red algae in multiple stages; (C) it provides a method for producing pulp using a thin skinned red algae comprising the step of collecting the fiber bleached red algae and pulping.

In the present invention, the thin skin red algae may be characterized by being a kind of urticaria , Gelidium Chilense , Gelidium Elegans , and Gelidium Japonicum . It may be characterized in that it further comprises the step of curing the fiber before step (c), wherein the multi-stage bleaching process of step (b) is i) O ₃ (ozone) bleaching; ii) Element Chlorine Free (ECF) or Total Chlorine Free (TCF) bleaching; And iii) H ₂ O ₂ (hydrogen peroxide) bleaching step, and may further comprise adding a reducing agent in step iii).

In the present invention, O ₃ (ozone) bleaching of step i) may be repeated until the whiteness of red algae is 50 or more, and ECF (Element Chlorine Free) or TCF of step ii) (Total Chlorine Free) Bleaching may be repeated until the whiteness of the red algae is more than 60, the iii) H ₂ O ₂ (hydrogen peroxide) bleaching is repeated until the whiteness of the red algae is 70 or more It can be characterized by performing.

The present invention also provides a red algae pulp produced by the above method and a process for producing paper, characterized in that the red algae pulp is 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, which is a cell wall component of red algae with hot water. Red algae are widely used as raw materials of agar, such as wood starfish, ox radish, buckwheat, braid, thorny radish, silk grass, edamame, stone fern, stone and jinari. 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 ℃, it is characterized by little change in the original gel properties even after repeated gelling and dissolution. Transparent gels are easy to color, and the addition of sugar, glucose, glycerin, etc. increases the refractive index and makes it glossy.

As a raw material according to the present invention, the red algae may be any one or more selected from the group consisting of Locust spruce tree, Dolphin spree, gambling tree, and Noodle sprout tree, but includes all red algae in which minimal fiber exists.

Usually, agar extracted from hot water from wormwood or stalks has a stronger strength than carrageenan extracted from hot water from Kotoni or Spino island, and agar components extracted from hot water from stalks are superior to 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 from pulp as compared to the gel component of 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 Bleaching Process of Red Algae

Red algae, which can be pulped only by the bleaching process, are soft as the outer shell of red algae and are excellent in oxidation reaction and acid reaction. It was immersed in an acid solution of pH 2-3 for a certain time, washed with water and then dehydrated. At this time, through the process of immersing the red algae in an acidic aqueous solution for a predetermined time, impurities are removed, the skin of the red algae is softened.

The acid-treated red algae is subjected to bleaching in multiple stages. First, bleaching treatment is performed using ozone. After ozone treatment, the dissolved gel extracts are compressed and removed by pressurization at a pressure of 2-10 kg / cm ² , and the ozone treatment is repeated. Ozone treatment is repeated until the color of red alga is over 50 based on whiteness.

After ozone treatment, go through ECF (Element Chlorine Free) process that bleaches with chlorine dioxide, or repeat TBC (Total Chlorine Free) bleaching process by further strengthening ozone bleaching process until whiteness is over 60 do.

As a final step of the bleaching process, bleaching with hydrogen peroxide is carried out. When bleaching with hydrogen peroxide, a reducing agent may be added to prepare pulp with a whiteness of 70 or more.

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 increases, the paper becomes more compact.

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  : Preparation of red algae pulp produced only by bleaching process

The outer skin was soft, and the type of shellfish was excellent in oxidation reaction and acid reaction. Representatively, wood starfish was immersed in pH 2.5 hydrochloric acid solution for about 1 hour, washed with water, and dehydrated. The acid-treated urticaria was first bleached with ozone, then bleached with chlorine dioxide, and finally bleached with hydrogen peroxide to raise the whiteness to 80 or more. A small amount of hydrosulfite (Na ₂ O ₄ S ₂ ), a reducing agent, was added to bleach hydrogen peroxide to prevent further whiteness and discoloration of red algae pulp.

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.

According to the method for producing pulp using thin skinned red algae according to the present invention, the main raw material uses red algae rather than wood, so that pulp and paper can be produced at a low cost, and compared with the process of producing wood pulp. The use of chemicals for lignin removal and bleaching is significantly reduced, making it environmentally friendly. In addition, there is an advantage that the pulp can be produced with a high degree of whiteness only by the bleaching process without a separate extraction process.

Claims (10)

Method for preparing pulp using thin skinned red algae comprising the following steps: (a) immersing thin skin red algae in an acidic solution for a period of time, followed by washing with water and dehydrating; (b) bleaching the dehydrated red algae in multiple stages; (C) collecting and bleaching the bleached red algae pulp. According to claim 1, wherein the thin skinned red algae is one of Gelidium Chilense ( Gelidium Chilense ), Gelidium Elegans ( Gelidium Elegans ), Gelidium Japonicum characterized in that any one Method for producing pulp. The method of claim 1, further comprising the step of curing the fibers before step (d). The method of claim 1, wherein the multi-stage bleaching process of step (b) comprises the following bleaching processes: i) O ₃ (ozone) bleaching; ii) Element Chlorine Free (ECF) or Total Chlorine Free (TCF) bleaching; And iii) H ₂ O ₂ (hydrogen peroxide) bleaching. 5. The method of claim 4, wherein a further reducing agent is added in step iii). 5. The method of claim 4, wherein the bleaching of O ₃ (ozone) in step i) is repeated until the whiteness of the red alga is 50 or more. 5. The method of claim 4, wherein bleaching the ECF (Element Chlorine Free) or TCF (Total Chlorine Free) of step ii) is repeated until the whiteness of the red alga is 60 or more. 5. The method of claim 4, wherein the iii) H ₂ O ₂ (hydrogen peroxide) bleaching is repeated until the whiteness of the red alga is 70 or more. A pulp produced by the method of any one of claims 1 to 8. A pulp of claim 9 is processed, wherein the paper is produced.

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