KR100811183B1 - Method for Preparing a Pulp Having Low Content of Inner Gel Extract from Rhodophyta - Google Patents

Abstract

The present invention relates to a method for preparing pulp having a low content of internal gel extract from red algae, and more specifically, to remove red impurities and then washing with water to dehydrate the dehydrated red algae consisting of oxidized water, acidic chemicals and oxidizing agents. A pulp having a low content of internal gel extract from red algae comprising the step of extracting the gel by immersing in one or more extracting solvents selected from the group at a predetermined time and at a predetermined temperature, collecting the residues and converting the fibers into fibers, and then bleaching the fibers. It relates to a method of manufacturing.

In addition, according to the present invention, since the gel is extracted using an acidic extraction solvent, it is possible to obtain a gel extract having a lower viscosity than when extracted with water, thereby producing a pulp having a low content of the internal gel extract. The pulp is high in opacity and excellent in fusion.

Red algae, pulp, extractant, acid

Description

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

1 is a diagram showing the extraction process of red algae using oxidation water and acidic chemicals.

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

The present invention relates to a method for preparing pulp having a low content of internal gel extract from red algae, and more particularly, to remove red algae impurities, and then to wash and dehydrate the red algae, oxidizing water, acidic chemicals and oxidizing agents. After extracting the gel by immersing in any one or more extraction solvent selected from the group consisting of a predetermined time, the residue is collected and converted into fibers, and then produced pulp with low internal gel extract content from red algae comprising bleaching the fibers. It is about how to.

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 a wood sugar by producing paper through hydrolyzing, bleaching, and refining processes, 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 talignin 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 and bagasse. 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 the 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, can be used for various purposes, Therefore, the range of use is also wide. However, the conventional non-wood pulp had 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 the development of the extraction process of red algae for producing pulp, the extraction using an acidic extraction solvent, the viscosity is lower than the extraction using water The gel extract can be obtained, and the pulp prepared therefrom has a low content of the internal gel extract, thus making it possible to make a paper having high opacity and excellent bonding property, thereby completing the present invention.

After all, an object of the present invention is to remove the impurities of red algae, and then dehydrated after washing with water, and the gel is extracted by immersing the dehydrated red algae in an extraction solvent selected from the group consisting of oxidized water, an acidic chemical and an oxidizing agent at a predetermined time and a predetermined temperature. Thereafter, the residue is collected and converted into fibers, and then, a method for producing pulp having a low internal gel extract content from red algae comprising bleaching the fibers.

In order to achieve the above object, the present invention comprises the steps of (a) immersing red algae in an alkaline aqueous solution for a predetermined time, followed by washing with water and dehydrating; (b) extracting the gel by immersing the dehydrated red algae in an extraction solvent selected from the group consisting of oxidized water, an acidic drug and an oxidizing agent at a predetermined time and at a predetermined temperature; (c) separating the extracted gel and collecting the residue into a fiber; And (d) provides a method for producing a pulp with low 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 tree, Dolphin spree, Gambling beetle and Noodle sprouts tree, but includes all red algae in which minimal fibers are present. On the other hand, the acidic drug is characterized in that any one or more selected from the group consisting of hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ COOH) and carbonic acid (H ₂ CO ₃ ). The oxidizing agent may be hydrogen peroxide (H ₂ O ₂ ), permanganic acid (HMnO ₄ ), sodium percarbonate (2Na ₂ CO ₃ 3H ₂ O ₂ ), sodium perborate (NaBO ₃ 4H ₂ O), potassium permanganate ( KMnO ₄ ) and potassium dichromate (K ₂ Cr ₂ O ₇ ) It may be characterized in that any one or more selected from the group consisting of.

In the present invention, it may be characterized in that it further comprises the step of curing the fiber before the step (d), the extraction temperature of the step (b) may be characterized in that the 60 ~ 200 ℃. .

The present invention also provides a high opacity and excellent paper manufacturing method characterized in that the red algae pulp having a low content of the inner gel extract prepared by the method and the red algae pulp having a low content of the inner gel extract.

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, 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. Since agar has the opposite properties of coagulation and viscoelasticity, it can be used as a stabilizer, extender, forming agent, thickening agent, anti-drying agent, and 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.

The raw material according to the present invention 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, and also carrageenan obtained from red algae It is also possible to use agar or the like.

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 belonging to wood, stone, gambling and noodle plants are immersed in an aqueous alkali solution such as potassium hydroxide (KOH) for a certain 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.

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, and in particular, extraction of the red algae of the present invention. In the process, using an oxidized water or acidic chemicals, such as hydrochloric acid, sulfuric acid and so on adjusted to pH 6.5 or less, and the temperature is reacted in a pressure tank at 60 ℃ ~ 200 ℃, an effective extraction process proceeds. Oxidized water, acidic chemicals, and oxidizing agents can be used as extraction solvents to produce gel extracts of lower viscosity than water, alcohols 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 twice with H ₂ O ₂ (1hr / 1). After that, the fiber can be produced 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 a size 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 Oxidized Water and Acidic 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 water, oxidized water and hydrochloric acid (HCl), each raw material was tested by diluting 20 times with water. As a raw material, a red algae jellydium ( Gelidium Chilense ) was used. When extracting Gelidium Chilense as red algae using water for 2 hours at 130 ° C, 56% of the gel extract was eluted, 62% for oxidized water and 72% for pH 2.5 in hydrochloric acid. Gel extracts were able to elute, respectively. When extracted using oxidized water and acidic chemicals, it was found that the viscosity of the eluted gel extract was very low, and the viscosity of the gel extract was significantly lowered as the pH was significantly lowered. After the extraction process was completed, a bleaching process as shown in FIG. 2 was carried out. The yield and the properties of the paper were 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 oxidized water or acidic chemicals, compared to the residues remaining after extraction with water, they had higher whiteness and higher tensile strength under the same bleaching conditions, and as shown in Table 1, the total yield of pulp was When extracted with oxidized water or acidic chemicals rather than extracted with water, the pulp prepared in this way is less opaque than ordinary wood chemical pulp when paper is made because there is almost no gel extract remaining inside. It was found that high intensity was expressed.

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 Oxidation water 59.67 0.71 5.96 2.61 2.22 2.68 81.15 29.83 11.33 HCl 60.67 0.70 5.72 2.12 1.70 3.30 80.23 81.63 6.33

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 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 an acidic extraction solvent, it is possible to obtain a gel extract having a lower viscosity than that extracted with water, thereby producing a pulp having a low content of the internal gel extract, and the pulp Opacity is high and the paper is excellent.

Claims (8)

Method for preparing pulp with low internal gel extract content from red algae comprising the following steps: (a) immersing red algae in an alkaline aqueous solution for a predetermined time, followed by washing with water and dehydrating; (b) extracting the gel by immersing the dehydrated red alga in an extraction solvent selected from the group consisting of oxidized water and an acidic drug at a predetermined temperature for a predetermined time; (c) separating the extracted gel and collecting the residue into a fiber; 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 method of claim 1, wherein the acidic drug is selected from the group consisting of hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ COOH) and carbonic acid (H ₂ CO ₃ ) It is any one or more of the pulp production method. delete 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 production method, characterized in that 60 ~ 200 ℃. Red algae pulp having a low content of internal gel extract prepared by the method of any one of claims 1 to 3, 5 or 6. A process for producing paper having high opacity and excellent bonding, characterized by processing red algae pulp having a low content of the internal gel extract of claim 7.

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