KR100978694B1 - Manufacturing method of the opaque thin paper and the opaque thin paper - Google Patents

Abstract

The present invention relates to a method for producing an opaque low basis weight paper and an opaque low basis weight paper. More specifically, the method for producing an opaque low basis weight paper includes the steps of: a) beating red algae fibers; b) screening and selecting beaten red algae fibers to produce red algae pulp; c) mixing 0.01-10 parts by weight of an additive with 100 parts by weight of the red algae pulp to form a pulp composition; d) pressing the formed pulp composition; e) dehydrating and drying the compressed pulp composition; and a method for producing an opaque low basis weight paper comprising the opaque low basis weight paper.

In addition, since the present invention can produce a low basis weight paper having a basis weight of 100 g / m ² or less using an inorganic filler or using a relatively small amount through a method of preparing an opaque low basis weight paper containing red algae pulp. There is an advantage in that the strength decrease due to the addition of the filler does not occur. In addition, paper using red algae pulp shows higher opacity and higher smoothness than using filler, and shows excellent printing characteristics. In addition, since there are less minerals inside the paper, the bays on the paper have fewer scratches. In addition, the red algae pulp is economical because it can be purchased at a lower cost than wood pulp when mass produced.

 Red algae, paper, opacity, smoothness, tensile strength, red algae pulp, wood pulp

Description

Manufacturing method of the opaque thin paper and the opaque thin paper

The present invention relates to a method for producing opaque low basis weight paper and its opaque low basis weight paper, and more particularly, to use an inorganic filler through a method for manufacturing opaque low basis paper including red algae pulp extracted from red algae The present invention relates to a method for producing an opaque low basis weight paper having a basis weight of 100 g / m ² or less using a relatively very small amount and an opaque low basis weight paper.

In general, red algae contain significant amounts of fiber from which paper can be made. Red algae grow much faster than trees and grow in most of the oceans except polar regions, so you don't have to compete with other pulp that is made from land-based raw materials. Mathematically, if you grow red algae in the size of a Korean peninsula in a subtropical sea where red algae grows well enough, you can get the amount of raw material for all pulp in the world.

In addition, red algae are known to absorb carbon dioxide about 1.5 times better than trees in the same area. Therefore, sufficient global cultivation of red algae can also reduce global warming.

Red algae are red algae that grow in the sea, and belong to the red algae gate and the red algae river. There are about 5,000 to 6000 red algae in the world. Red algae have a red flushing surface on the surface, which surrounds the chlorophyll, which helps to absorb the light needed for photosynthesis. Inside the red algae are paper fibers and water-soluble polysaccharides. Since red algae may or may not have red fiber, the species of red algae should be well selected, and the species containing many of the superior fibers should be selected.

Wood is composed mainly of cellulose, hemicellulose, and lignin, and pulp is produced through the pulping and bleaching processes. Pulping and bleaching is the process of removing lignin from wood. At this time, high temperature, high pressure process is required, and very strong chemicals are used. On the other hand, red algae are free of lignin and consist of red fiber and water-soluble sugars. These sugars do not require chemicals, high temperatures or high pressures, and are mostly extracted at temperatures between 60 and 120 ° C. Extracted sugars are produced in agar.

After sugar extraction, red algae are bleached to produce a pulp with a whiteness similar to that of ordinary wood pulp. In wood, the bleaching process can also be seen as the extraction of lignin, which is usually more powerful than the pulping process. Red algae use less bleach than wood pulp. Making red algae pulp from red algae can significantly reduce the environmental burden because it consumes less chemical and energy than producing pulp from wood. In addition, polysaccharides extracted as a by-product of red algae may be utilized in various fields, including food.

Flush fibers used as pulp are very thin. Thinner fibers increase the surface area of the fibers per unit weight and these fibers are suitable for various filters. In addition, the surface of the paper is very hard and plays a big role in increasing the smoothness. In fact, the smoothness of paper made of redness fibers is usually 2 to 5 times higher than that of paper made of ordinary wood fibers. This smoothness is the most important quality factor in printing.

Another feature of redness fibers is that they do not require the beating process, which must go through when making paper from wood fibers. The beating process refers to the process of tapping or cutting wood fibers with physical force. Wood fibers go through this beating process and are made of high strength paper. Flushing fibers can be used to produce paper with the same strength as wood fibers, even if used as is without beating.

It is common to include fillers and whitening agents in paper to improve the optical properties of wood pulp. Paper with high opacity is particularly preferable for writing paper and high-quality printing paper. In this regard, it is necessary to properly retain the filler in the fiber in order to ensure that the filler remains with the fiber in the paper making process. Commercially, this is generally accomplished by agglomerating fillers and fibers using cationic starch (Polyacrylamide (PAM)) or similar flocculants. However, even with such processing aids, filler losses can be significant, particularly in products with low reference basis weights or high speed papermaking processes. Low retention of fillers can lead to blockage of the papermaking felt, contamination of the white water system and an increase in raw material costs. As such fillers, calcium carbonate, titanium dioxide, talc, clay and other suitable mineral salts have been incorporated into the fibers, but too much of the paper reduces the strength of the paper and makes it difficult to use as recycled paper. If not enough, the problem remains.

Paper is originally porous and has excellent water absorption. It is often required to provide resistance to liquid penetration other than water to the types and uses of paper, starting with ink leakage prevention of printing paper and writing paper. This treatment is called sizing, and there are two methods, an internal additive sizing mixed with a paper material such as pulp and paper sizing, and a surface sizing applied on paper by a size press or calendar.

Among the internal additives, there are rosin-based sizing agents. The components of the rosin are mainly bibitanic acid, and raw materials are rosin obtained from gum rosin or coniferous kraft pulp. Rosin-based sizing agents include a solution-type rosin-based sizing agent (reinforced rosin size) in which alkali is added to solution of maleized rosin or fumarized rosin and an emulsion-type rosin sizing agent dispersed in water using an emulsifier. In addition, the use of aluminum sulfate as an adhesive makes acid paper, but recently, an emulsion type having a size effect in the neutral region has been developed and distributed. Synthetic sizing agent is the price of pine oil of rosin raw material is gradually increasing, the sizing agent was developed from petroleum resin. The synthetic sizing agent is an alkanylated alkenyl anhydrous baksan obtained from naphtha. Compared to the reinforcement rosin sizing agent, it has excellent size effect in the low addition region, and has been applied to a relatively hard internal addition size treatment.

Neutral sizing agents commonly used at present are reactive neutral sizing agents of alkyl ketone dimers (AKDs) and alkyl succinic anhydrides (ASAs). The AKD sizing agent is emulsified with stearic acid from Uji as a raw material and can be stored for several months. However, when the size effect is difficult to control or when the amount is large, the paper is likely to slip.

Intellectual enhancers are divided into surface intelligence enhancers and antistatic strength enhancers according to the method of use. Surface intelligence enhancers are usually applied in size presses, but starch is the most common. Starch is applied to the surface to give printability such as surface strength and smoothness, but starch is water-soluble and may not be sufficient for offset printing with water, and water-resistant chemicals (polyvinyl acetate; PVA, carboxy methyl cellulose; CMC, etc.) In some cases, it may be used. The anti-impingance enhancer is embedded in the pulp composition for the purpose of improving the strength of the paper (promoting hydrogen bonding between the pulp fibers) and improving the fixability of the filler and the fine fibers. Cationized starch is the most common, but polyacrylamide (PAA) is also frequently used. Wet strength enhancers may be added to give special strength to wet paper. Wet strength enhancers include melamine resins, polyethyleneimines, polyamide polyamine resins, and the like.

Other preparations include dispersants, water repellents, retention aids, antidusting agents, pH adjusters, adhesives, pigments or dyes.

The adhesive adheres the additives to each other and at the same time serves to adhere the additives to the paper, which influences the stability and flowability of the collar. The amount of adhesive and the distribution in the coating layer also affect the optical properties and print quality of the paper. Adhesives are divided into natural and synthetic adhesives. Natural adhesives are casein, synthetic adhesives include latex and PVA, but starch and latex are often used in combination.

Retention enhancers are added to improve retention of pulp fibers or fillers on papermaking wire. Also called a flocculant. There is a cationic agent which neutralizes and aggregates negatively charged paper material with positive charge, and a polymer polymer crosslinked and aggregated between particles. Neutral grassland relies on retention improvers because the retention is worse if calcium carbonate is used without alumina sulfate and relatively small particle size.

Dye is added to adjust the color. There are basic dyes, direct dyes, fluorescent dyes, etc., which should be selected in consideration of color and operability. Foaming in the process adversely affects operation and causes further deterioration. For this reason, there are two types of antifoaming agents that destroy bubbles and those that suppress bubbles.

The filler is the most used in the raw material of paper except pulp, and 5 to 35% by weight is contained in the paper. It is common to use 15 to 35% by weight for low basis weight paper. Mineral paper is added to the pulp when papermaking is used, and clay, kaolin, calcium carbonate, etc. are used, and it is called a filler because it is a material filling the gap in the paper. The filler makes the paper white and opaque and improves the printability, dimensional stability and handwriting of the paper. However, there is a disadvantage in that the intelligence is lowered, and the contamination becomes easier due to friction during papermaking.

A basis weight is a unit which means mass with respect to a unit area, and generally low basis weight paper means the paper which has a basis weight of 100 g / m <^2> or less. These low basis weight papers are used in many industries such as newspapers and OA paper. In the case of low basis weight paper, it is inevitable that the lowering of the intellect is inevitable because a relatively large amount of filler must be used for opacity.

 In order to solve the problem of paper made of wood pulp, a technique for producing pulp and paper from green algae fibers (Korean Patent Registration No. 0754890) is known. The technique includes the step of producing a pulp by extracting fibers from red algae, but the invention alone has a difficulty in producing a low basis weight paper with high opacity.

The present invention is to solve the problems of the prior art, to overcome the problems of low basis weight paper without containing calcium carbonate, which is a filler of paper, and to achieve the high opacity, high strength, high smoothness and excellent printability of paper. It is an object of the present invention to provide a low basis weight paper manufacturing method having high opacity.

The object of the present invention is to a) beating algae fibers; b) screening and selecting beaten red algae fibers to produce red algae pulp; c) mixing 0.01-10 parts by weight of an additive with 100 parts by weight of the red algae pulp to form a pulp composition; d) pressing the formed pulp composition; And e) dehydrating and drying the compressed pulp composition. It can be achieved by providing a method for producing an opaque low basis weight paper comprising a.

In addition, the present invention is to solve the problems of the prior art, to overcome the problems of low basis weight paper without containing calcium carbonate as a filler of paper, with high opacity, high strength, high smoothness and excellent printability The purpose is to provide a low basis weight paper having a high opacity of the paper.

The above object of the present invention can be achieved by providing an opaque low basis weight paper having a basis weight of 0.1 to 100 g / m ² produced by the production method.

The present invention provides a method for producing opaque low basis weight paper, the method comprising: a) beating red algae fibers; b) screening and selecting beaten red algae fibers to produce red algae pulp; c) mixing 0.01-10 parts by weight of an additive with 100 parts by weight of the red algae pulp to form a pulp composition; d) pressing the formed pulp composition; And e) dehydrating and drying the compressed pulp composition.

Specifically, the method for producing opaque low basis weight paper according to the present invention consists in extracting red algae fibers contained in red algae from red algae to produce red algae pulp, and producing paper with them. Provided is a method for producing paper exhibiting an improved opacity even when a small amount of inorganic filler such as calcium carbonate is added or not added to the red algae pulp.

The red algae fiber is made to be suitable for papermaking by beating the red algae fiber, and the red algae pulp is prepared by selecting and selecting the red algae fiber in order to make the paper properties constant. The sorted and selected red algae pulp is papermaking and processed to produce red algae paper.

At this time, in order to prepare an opaque low basis weight paper containing red algae fibers, the red algae pulp may be prepared by a method known in the patent application 2005-0096046.

The extract was removed from the red algae at 100 ° C. and 1 g of red algae pulp was added to 1 liter of distilled water, and when boiled for 1 to 2 hours, when the weight loss of the fiber was 0.5 to 10 wt%, the extract was sufficiently removed. can do. That is, red algae pulp having a residual extract of 0.5 to 10% by weight is used.

When the red algae pulp having the above characteristics is added to the paper in an amount such as calcium carbonate, which is commonly used in the manufacture of woodfree paper, opacity comparable to the paper to which the filler is added can be obtained. More red algae pulp can be added to achieve higher opacity. To replace expensive, high quality fillers such as titanium dioxide, more red algae fibers would have to be added than in the case of calcium carbonate fillers.

Selecting and selecting the red algae fibers to produce pulp, and mixing the pulp composition with 0.1 to 10 parts by weight of an additive to 100 parts by weight of the pulp. The additives include one selected from dyes, size agents, retention enhancers, intensifiers, dispersants, water resistant agents, retention enhancers, anti-dusting agents, pH adjusters, adhesives, pigments or dyes.

In addition, the pulp composition further comprises 0.01 to 10 parts by weight of inorganic filler. If necessary, the pulp composition may be prepared by adding an amount smaller than 15 to 35 parts by weight of the inorganic filler generally used.

In addition, the pulp composition further comprises 20 to 400 parts by weight of wood pulp. The pulp composition further comprises 0.01 to 50 parts by weight of an inorganic filler in the pulp composition further comprising wood pulp.

The red algae pulp and wood pulp may be mixed to produce paper. Paper may be prepared by including 20 to 400 parts by weight of wood pulp in the pulp composition. This increases the opacity of the wood pulp without adding filler. The process for producing pulp from wood stock is described below. 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. 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 production of chemical pulp, most of the cell membrane lignin as well as the lignin in the intercellular layer of the raw material are removed, and at the same time, many hemi-celluloses are dissolved and some cellulose is also degraded. Chemical pulp has a high quality, ie, high purity of cellulose, but has low yields and high production costs. Chemical pulp production methods include sulfurous acid method, soda method and sulfate method. The selection process is a process of washing and screening the fibers obtained from the raw material after the pulping process to remove the parts and contaminants that are not completely pulped, and can be bleached if necessary.

The red algae is at least one selected from the group consisting of Locust spruce tree, Dolphin spree, Gambling tree, or Noodle sprout tree. It is also possible to use carrageenan or agar obtained from red algae.

The production method for producing paper exhibiting high opacity by combining the red algae pulp and wood pulp, with or without using significantly less inorganic fillers, is as follows.

1. Raw materials: red algae

Red algae inhabit relatively deeper water than other algae, and are relatively small in size. Red algae that are widely used as raw materials of daikon radish include wormwood, daikon radish, buckwheat, pods, thorny radish, silk grass, edamame, stone fern, stone and Jinuari. Daikon consists of agarose and agaropectin. The neutral polysaccharide agarose (agarose) is a gel (gel) has a strong property to increase the strength, while the acidic polysaccharide agaropectin (agaropectin) is weak gel, but viscoelastic and conservative. Since the radish has coagulation properties and viscoelasticity, which are opposite properties, it can be used as a stabilizer or a physical property maintaining agent by adjusting two physical properties.

In addition, the radish exhibits stronger gelling properties than any other gelling agent. The radish forms a gel at room temperature, and once formed gel is melted at a high temperature, even if the gelation and dissolution are repeated, there is 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.

Here, the red algae fibers are immersed in an acid solution of red algae pH 1-4 for a predetermined 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 washed and dehydrated red algae are extracted through a solvent to extract gels and bleached to prepare pulp. At this time, the extraction solvent may be used water, ethyl alcohol, methyl alcohol, acetone and ketones. Since the melting point of the gel is 50 ~ 70 ℃ the temperature of the extraction solvent is preferably heated to 50 ~ 70 ℃.

Bleaching is carried out through ECF (Element chlorine free) bleaching process using bleaching with ozone and chlorine dioxide, or TCF (Total Chlorine Free) bleaching process using ozone and hydrogen peroxide. Manufacture.

The red algae pulp may include extracting or bleaching red algae fibers included in red algae, and using pulp extracted at 0.5 to 10% by weight when the remaining extract is boiled at atmospheric pressure for 1 to 2 hours with distilled water. The red algae pulp is extracted or bleached and finished with red algae pulp, and the remaining extract uses fiber which is reduced in weight by 0.5 to 10% by weight when boiled at atmospheric pressure for 1 to 2 hours with distilled water. If the residual extract is more than 10% by weight, the opacity is lowered when the pulp is prepared in pulp, so the content of the residual extract is important.

2. Manufacturing method of red algae paper

The preparation of red algae paper comprising the red algae pulp generally produces a paper with high opacity similar to the step of preparing paper. In order to increase the opacity, the use of an inorganic filler generally causes a decrease in strength. However, when the red algae pulp is used, an inorganic filler is not used. Thus, a paper having a high opacity and a low basis weight can be produced.

In general, "paper" refers to a cellulose fiber in a sheet form for use in printing, writing, packaging, and the like, and refers to "paper" for producing paper suitable for a purpose by various treatments. The paper making process, or papermaking process, varies slightly depending on the purpose of the paper, which is the final product.

1) Confession process

If the pulp produced at the pulp mill is made of paper without any processing, the paper is difficult to be used for general purposes, such as weak strength and rough surface, resulting in excessively high air permeability. This is because the fibers of natural pulp are rigid, and the surface area is small, so that the bonding between the fibers does not occur easily.

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 glass beating, and fibrillation is usually called beating. By beating, the fiber outer layer is removed and internal fibrillation takes place, the length of the fiber is cut, microfibers are formed, and partial dissolution of the chemical composition occurs. The beating makes the fibers flexible and increases the bonds between the fibers, so that as the altitude increases, the paper becomes more compact.

In addition, the step of producing red algae paper from the red algae pulp further comprises the step of mixing the wood pulp with the red algae pulp. Mixing the wood pulp to the red algae pulp includes a method of mixing 10 to 90 parts by weight of red algae pulp and 90 to 10 parts by weight of wood pulp. Paper made with a mixing ratio of wood pulp and red algae pulp at 80:20 has a higher opacity and tensile strength and is relatively superior to paper made by mixing the wood pulp and inorganic filler at a ratio of 80:20. There is an advantage that can produce a paper showing the smoothness.

2) Screening and selection process

Before the paper is sent 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) Grassland process

It is a process of making a paper by crimping | bonding, dehydrating, and drying after forming a paper-based paper from the paper mixed with the pulp, a size agent, and various additives. The sizing process is a process of imparting resistance to penetration of ink or water into paper, and the chemicals used are called sizing agents. 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.

The additives include any one or more of dyes, sizing agents, retention enhancers, intensifiers, dispersants, water repellents, retention enhancers, antidusting agents, pH adjusters, adhesives, pigments or dyes.

In addition, when a large amount of inorganic filler is used in order to increase the opacity in manufacturing a low basis weight paper having a basis weight of 100 g / m ² or less, there is a disadvantage that the strength is generally reduced. When the red algae pulp is used, an inorganic filler is not used at all, or only a small amount of the algae pulp has the advantage of producing a low basis weight paper having high opacity and excellent strength.

4) Machining

Processing is a process of performing various processing such as coating and laminating using manufactured paper as a base.

In the papermaking method according to the present invention, since red algae pulp is used as a raw material, the beating process is not essential, but in some cases, there may be a beating process. Steps 2) to 4) may also be selectively performed.

It also includes an opaque low basis weight paper having a basis weight of 0.1 to 100 g / m ² produced by the opaque low basis weight paper manufacturing method of the present invention. The opaque low basis weight paper prepared according to the manufacturing method is excellent in paper, and has an advantage of high opacity and excellent smoothness. It is also economical due to the simplification of the process.

As described above, the method for producing an opaque low basis weight paper comprising red algae pulp according to the present invention does not use an inorganic filler or uses a relatively small amount to produce a low basis weight paper having a basis weight of 100 g / m ² or less. Since it is possible to do this, there is an advantage that the decrease in strength due to the addition of the filling whole does not occur. In addition, paper using red algae pulp shows higher opacity and higher smoothness than using filler, and shows excellent printing characteristics. In addition, since there are less minerals inside the paper, the bay on the paper has the advantage of less scratches.

By using red algae pulp instead of the filler, it is possible to reduce the reduction in paper strength due to the use of the filler even under the same opacity, and to produce an opaque paper using only organic materials that do not contain any inorganic filler. In addition, the increased strength due to the use of red algae pulp leads to a reduction in the basis weight of the paper, thereby reducing the production cost. The addition of red algae pulp increases the smoothness of the paper and improves the printability of the paper. Particularly in the case of low basis weight paper, it is very difficult to hold the filler, but since the use of red algae pulp is excellent, the retention system can be simplified and the cost can be reduced. In addition, the red algae pulp is economical because it can be purchased at a lower cost than wood pulp when mass produced.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

Example  One

As shown in Table 1, 2 parts by weight of starch and 2 parts by weight of alkyl ketone dimer (AKD) were added as additives to 100 parts by weight of red algae pulp (BRAP) to give a basis weight of 45 g / m ² . Paper was prepared.

Example  2

As shown in Table 1, 20 parts by weight of conifer bleached pulp (Sw), 80 parts by weight of red algae pulp (BRAP), 2 parts by weight of starch and 2 parts by weight of alkyl ketone dimer (AKD) as additives 45 g / m ² of paper was prepared.

Example  3

As shown in Table 1, 70 parts by weight of red algae pulp (BRAP) 30 parts by weight of softwood pulp (Sw) softwood, 1 part by weight of starch as an additive and 2 parts by weight of alkyl ketone dimer (AKD) Part was added to prepare a paper having a basis weight of 45 g / m ² .

Example  4

As shown in Table 1, 80 weights of pulp (Hw + Sw) mixed with 500 CSF after mixing coniferous and hardwood pulp (Hw) pulp at 50:50 to 20 parts by weight of red algae pulp (BRAP) In addition, 1 part by weight of starch and 2 parts by weight of AKD (alkyl ketone dimer) were added as c additives to prepare a paper having a basis weight of 45 g / m ² .

Example  5

As shown in Table 1 below, 70 parts by weight of pulp (Hw + Sw) mixed with 500 CSF after mixing coniferous and hardwood pulp at 50:50 to 20 parts by weight of red algae pulp (BRAP), and conifer bleaching pulp (Sw). ) Was added 10 parts by weight, 1 part by weight of starch (Starch) and 2 parts by weight of AKD (alkyl ketone dimer) was added to prepare a basis weight 45g / m ² of paper.

Example  6

As shown in Table 1, 2 parts by weight of starch and 2 parts by weight of alkyl ketone dimer (AKD) were added to 100 parts by weight of red algae pulp (BRAP) to prepare a paper having a basis weight of 80 g / m ² . .

Example  7

As shown in Table 1, 20 parts by weight of conifer bleached pulp (Sw), 80 parts by weight of red algae pulp (BRAP), 2 parts by weight of starch and 2 parts by weight of alkyl ketone dimer (AKD) as additives 80 g / m ² of paper was prepared.

Example  8

As shown in Table 1 below, by adding 30 parts by weight of conifer bleaching pulp (Sw) to 70 parts by weight of red algae pulp (BRAP), 1 part by weight of starch and 2 parts by weight of alkyl ketone dimer (AKD) as an additive A paper having a basis weight of 80 g / m ² was prepared.

Example  9

As shown in Table 1 below, 80 parts by weight of pulp (Hw + Sw) mixed with 500 CSF was mixed with coniferous and hardwood pulp at 50:50 to 20 parts by weight of red algae pulp (BRAP) and starch (c additive). 1 part by weight of Starch) and 2 parts by weight of an alkyl ketone dimer (AKD) were added to prepare a paper having a basis weight of 80 g / m ² .

Example  10

As shown in Table 1 below, 70 parts by weight of pulp (Hw + Sw) mixed with 500 CSF and mixed with coniferous and hardwood pulp at 50:50 to 20 parts by weight of red algae pulp (BRAP), conifer bleached pulp (Sw) ) Was added 10 parts by weight, 1 part by weight of starch (Starch) and 2 parts by weight of AKD (alkyl ketone dimer) was added to prepare a basis weight of 80 g / m ² of paper.

Example  11

As shown in Table 1, 70 parts by weight of red algae pulp, 20 parts by weight of conifer bleaching pulp (Sw), 10 parts by weight of calcium carbonate, 2 parts by weight of starch as an additive, and 2 parts by weight of alkyl ketone dimer (AKD) Part was added to prepare a paper having a basis weight of 80 g / m ² .

Comparative example  One

As shown in Table 1, mixed coniferous and hardwood pulp at 50:50, mixed with 20 parts by weight of calcium carbonate to 80 parts by weight of pulp (Hw + Sw) beaten with 500 CSF, and starch (starch) 2 by weight as an additive. Part and 2 parts by weight of an alkyl ketone dimer (AKD) were added to prepare a paper having a basis weight of 45 g / m ² .

Comparative example  2

As shown in Table 1, after mixing coniferous and hardwood pulp at 50:50, mixed 20 parts by weight of calcium carbonate to 80 parts by weight of pulp (Hw + Sw) beaten with 500 CSF, and 2 parts by weight of starch as an additive. And 2 parts by weight of an alkyl ketone dimer (AKD) were added to prepare a paper having a basis weight of 80 g / m ² .

Each Example and Comparative Example are shown in Table 1 the components and representative basis weight.

division Representative basis weight Ingredients (parts by weight) Example 1

45g / m ² BRAP (100) + Starch (2) + AKD (2) Example 2 BRAP (80) + Sw (20) + Starch (2) + AKD (2) Example 3 BRAP (70) + Sw (30) + Starch (1) + AKD (2) Example 4 BRAP (20) + (HW + Sw) (80) + Starch (1) + AKD (2) Example 5 BRAP (20) + (HW + Sw) (70) + Sw (10) + Starch (1) + AKD (2) Comparative Example 1 (HW + Sw) (80) + CaCO ₃ (20) + Starch (2) + AKD (2) Example 6

80 g / m ²

BRAP (100) + Starch (2) + AKD (2) Example 7 BRAP (80) + Sw (20) + Starch (2) + AKD (2) Example 8 BRAP (70) + Sw (30) + Starch (1) + AKD (2) Example 9 BRAP (20) + (HW + Sw) (80) + Starch (1) + AKD (2) Example 10 BRAP (20) + (HW + Sw) (70) + Sw (10) + Starch (1) + AKD (2) Example 11 BRAP (70) + Sw (20) + CaCO ₃ (10) + Starch (1) + AKD (2) Comparative Example 2 (HW + Sw) (80) + CaCO ₃ (20) + Starch (2) + AKD (2)

Experimental Example

Paper was prepared as in Table 1, and the results are shown in Table 2 below.

division representation
Basis weight Ingredients (parts by weight) Basis weight
(g / m ² ) density
(g / cm ³⁾ Thermal insulation
(km)
Smoothness Whiteness
(ISO) Opacity
(%) obverse The back Example 1






45g / m ²




BRAP (100) + Starch (2) + AKD (2) 44.66 0.56 2.41 57.80 22.68 90.02 91.62 Example 2 BRAP (80) + Sw (20) + Starch (2) + AKD (2) 45.78 0.60 3.20 72.44 26.82 88.54 90.28 Example 3 BRAP (70) + Sw (30) + Starch (1) + AKD (2) 45.80 0.62 3.69 69.00 13.68 89.04 88.49 Example 4 BRAP (20) + (HW + Sw) (80) + Starch (1) + AKD (2) 45.54 0.66 4.61 20.62 4.52 85.59 78.20 Example 5 BRAP (20) + (HW + Sw) (70) + Sw (10) + Starch (1) + AKD (2) 46.85 0.66 4.85 21.48 4.84 84.59 78.05 Comparative Example 1 (HW + Sw) (80) + CaCO3 (20) + Starch (2) + AKD (2) 45.58 0.65 3.22 14.58 3.78 85.10 77.77 Example 6






80 g / m ²










BRAP (100) + Starch (2) + AKD (2) 82.19 0.56 2.59 50.12 20.52 89.83 97.01 Example 7 BRAP (80) + Sw (20) + Starch (2) + AKD (2) 80.75 0.59 3.73 69.74 19.52 88.63 95.95 Example 8 BRAP (70) + Sw (30) + Starch (1) + AKD (2) 82.03 0.63 3.85 60.92 12.32 89.00 95.05 Example 9 BRAP (20) + (HW + Sw) (80) + Starch (1) + AKD (2) 82.37 0.67 4.75 22.22 3.00 84.50 89.61 Example 10 BRAP (20) + (HW + Sw) (70) + Sw (10) + Starch (1) + AKD (2) 83.98 0.70 5.07 16.94 3.00 86.66 89.30 Example 11 BRAP (70) + Sw (20) + CaCO3 (10) + Starch (1) + AKD (2) 82.72 0.62 3.25 55.42 15.30 90.23 96.23 Comparative Example 2 (HW + Sw) (80) + CaCO3 (20) + Starch (2) + AKD (2) 82.49 0.69 3.24 10.64 2.08 84.91 88.64

The physical properties of general paper and the physical properties of Comparative Example 1 and Comparative Example 2 are the same. Example 1, Example 2, and Example 3 without filler at the same representative basis weight of 45 g / m ² showed high opacity when compared to Comparative Example 1. Example 6, Example 7, and Example 8, which did not contain the same representative basis weight filler of 80 g / m ² , exhibited high opacity when compared to Comparative Example 2.

At the same representative basis weight of 45 g / m ² , Example 4 and Example 5, which were mixed with 20 parts by weight of red algae pulp and 80 parts by weight of wood pulp, were also found to have a higher opacity than Comparative Example 1 using a filler. In the same representative basis weight of 80 g / m ^2, the opacity of Example 9 and Example 10, in which 20 parts by weight of red algae pulp was added to 80 parts by weight of wood pulp, was also higher than that of Comparative Example 2 using a filler. In particular, in Example 11 in which 10 parts by weight of a filler was added to 20 parts by weight of red algae pulp, the strength was confirmed to be similar to that of Comparative Example 2, and smoothness, opacity, and whiteness were all excellent. In the case of Example 11, since the density was also significantly lower than that of Comparative Example 2, it was confirmed that the paper was excellent in the sense of thickness.

Red algae pulp was found to have high smoothness and high thermal shortness. Example 1, Example 2, Example 3, Example 8, Example 9, and Example 11 having 70 parts by weight or more of red algae fibers were significantly reduced in density, thereby making it possible to manufacture paper having a good thickness to basis weight.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (8)

a) beating red algae fibers; b) screening, selecting and extracting beaten red algae fibers to produce red algae pulp having a red algae internal gel content of 0.5 to 10 wt%; c) mixing 0.01-10 parts by weight of an additive with 100 parts by weight of the red algae pulp to form a pulp composition; d) pressing the formed pulp composition; And e) dehydrating and drying the compressed pulp composition. The method of claim 1, further comprising 0.01 to 10 parts by weight of an inorganic filler in the pulp composition.  The method of claim 1, wherein the pulp composition further comprises 20 to 400 parts by weight of wood pulp. The method for producing an opaque low basis weight paper according to claim 3, further comprising 0.01 to 50 parts by weight of an inorganic filler. The method of claim 1, wherein the red algae is at least one selected from the group consisting of Locust spruce, Dolphin spree, Gambling spree, and Noodle sprouts. delete The method of claim 1, wherein the additive comprises at least one of a dye, a sizing agent, a retention aid, an intelligence enhancer, a dispersant, a water repellent, a retention enhancer, a dusting agent, a pH adjuster, an adhesive, a pigment, or a dye. Method for producing opaque low basis weight paper. An opaque low basis weight paper having a basis weight of 0.1 to 100 g / m ² produced by the production method according to claim 1.