JP2002363880A - HIGH QUALITY PAPER WITH 100% NON-WOOD PULP (BAGASSE PAPER-a) AND METHOD FOR PRODUCING THE SAME - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper and a method for producing the same for meeting with a need of solving problems in that although a bagasse pulp is produced in a relatively large amount as a non-wood pulp and capable of being supplied in a large amount, the pulp does not have an excellent strength singly, not only the improvement of the strength by beating is not expected but also the tearing strength and water filterability markedly decrease, and the paper making adoptability becomes worse and the obtained paper is a crispy low quality one, and conventionally, a needle tree pulp is used as a filler for producing and supplying a paper suitable for a market, but in consideration of the general earth environment, a need of 100% non-wood pulp is increasing, however, the amount of a non-wood long fiber pulp substituting for the needle tree pulp is extremely small in the south. SOLUTION: This method for producing the paper with the 100% non-wood pulp is to blend a PA method pulp by using waste jute as a raw material with the bagasse pulp for improving various strengths as well as the tearing strength. By blending a straw pulp and cotton pulp as required, it is possible to provide a good quality printing paper having a preferable printing adoptability and touch feeling with the 100% non-wood pulp.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to high quality paper containing only non-wood pulp and a method for producing the same.

[0002]

2. Description of the Related Art As a means of solving the problem of the natural environment, we reflect on the fact that paper, which has been used in large quantities, is made of wood pulp, and manufacture paper with non-wood pulp. The movement to use it has been increasing. And bagasse (pulverized sugar millet), which is easily and massively collected as a raw material, is pulped and mixed into wood pulp in a small amount.
There is a great deal of marketing to the market as non-wood paper. However, recently, some people have requested to use 100% non-wood pulp high quality paper if it is supplied. However, up to now, 100% bagasse pulp paper has been considered too weak for general use. Bagasse has a lower lignin content and a higher content of cellulose and hemicellulose than wood, so that pulping is easy and high-quality pulp is likely to be obtained in high yield. However, drawbacks such as low strength, poor strength, and particularly poor tear strength have been pointed out. Therefore, a large amount of bagasse pulp is usually blended with a small amount of softwood KP (kraft pulp), which has high strength and a large fiber length, as a connecting pulp to make a high-quality paper. At least, there is no choice but to increase the strength of bagasse pulp drastically, or to make the connecting pulp non-wood pulp and to supply it in large quantities. Bagasse pulp has a lower strength compared to the composition of its raw materials because the fibers are subjected to strong mechanical destruction during bagasse making and the fibers are short, preventing chemical damage at high temperatures due to chemicals during cooking. It is thought that it has received. Particularly, the damage by the AP cooking chemical (aqueous solution of sodium hydroxide alone) is severe, and the strength of the obtained pulp is not excellent. These drawbacks are that pulp obtained by cooking with KP cooking liquor (a mixture of sodium hydroxide and sodium sulfide) or PA cooking liquor (adding a cooking aid such as a stabilizer to an alkaline solution of hydrogen peroxide) It can also be understood that various strengths other than the tear strength are greatly improved. In any case, bagasse pulp alone is not strong enough. As the beating process proceeds, the breaking length and specific burst strength increase somewhat, but the freeness decreases, the suitability for papermaking decreases, the tear strength further decreases, and the resulting paper increases in density and becomes crisp and opaque. Has significantly decreased, and high-quality paper such as printing paper and industrial paper such as paperboard have been manufactured by blending 10-20% of KP of softwood. In the south, both timber and non-timber have generally been short in fiber length, and it has been said that long fibers other than hemp are not required. However, hemp is scarce in resources, is very valuable because it is a rope,
Non-wood long fiber pulp such as hemp is blended, and if the beating is advanced to obtain paper with a moderately high density and strength, the fibers are easily twisted, and the fibers stick together. This impairs the aesthetics of sashimi paper and significantly lowers its commercial value. In addition, non-fibrous impurities and dust, such as plant skins, are large in waste hemp, and it is not easy to separate and remove undigested matter and dust removal during pulping by conventional cooking methods. However, there is no report on a successful example of commercial production of high-quality paper such as printing paper, or a new plan, since the paper obtained by blending is very dirty and has a very poor commercial value.

[0003]

The present invention is based on bagasse pulp, which can be produced in large quantities but has low strength,
A high-quality paper made of 100% non-wood pulp with good strength and texture and a method for producing the same are provided.

[0004]

SUMMARY OF THE INVENTION According to the present invention, bagasse produced in large quantities in a sugar factory is produced by a conventional method or, preferably, a PA method.
Many jute and jute-like hemp which were not used in spite of large amounts of foreign substances such as skins and dust, which were difficult to digest, and which were difficult to separate and remove after cooking. By using the wastes and pulping by the PA method and selecting them carefully to obtain connecting pulp, it was possible to ensure the quality and quantity of non-wood connecting pulp. In other words, jute, kenaf, and roselle are different from flax and lami used for expensive clothing and the like, and are large in quantity, such as rice, wheat, soybeans, red beans, and other cereals and miscellaneous goods. Hemp is consumed in large quantities in the packaging of important materials, and is produced and consumed by the United Nations statistics alone at about 2.5 million tons per year. Many hemp dusts are produced during the production of hemp and hemp bags.However, as described above, pulp cannot be easily selected by the conventional method, so it is either filled or discarded or incinerated. Was. Thus, only a part of jute waste was used in the production of raw pulp for lower grade paper and industrial paper. In the present invention, a high-quality 100% non-wood pulp made of pulverized pulverized by the PA method and carefully selected and used as a connecting pulp is used in a relatively large amount as a connecting pulp. Made paper production possible. Furthermore, if desired, straw pulp or cotton pulp may be added in addition to jute pulp to provide a high-quality paper made of 100% non-wood pulp excellent in surface smoothness or texture and a method for producing the same.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Bagasse pulp used as a main raw material is desirably PA pulp. 100% of pulp obtained by any of AP method, KP method and PA method
It can be used as a main raw material for non-wood paper. But KP
Since the bagasse pulp obtained by the method or the PA method has a higher strength than that obtained by the AP method, the amount of tethered pulp added is small. Further, pulping bagasse by the PA method rather than pulping bagasse by the KP method results in unbleached pulp having a K
It is desirable for tackling global environmental issues because it has a whiteness of about bleached pulp of the P method and is easily chlorinated or low chlorinated during bleaching.

The pulping of bagasse by the PA method is carried out by a conventional method. The pulping conditions can be widely varied, but usually, caustic alkali and alkali carbonate are preferably 15 to 30% in terms of Na ₂ O as a total alkali, and the degree of causticization is 65 to 8
5%, ₂ to 5% of hydrogen peroxide as H ₂ O ₂ , 0.05 to 0.2% of anthraquinone, DTP as a chelating agent
A, 0.2-0.5% of 1-hydroxyalkylidene-1,1-phosphonic acid or a salt thereof, and 0.05 of NMP (normal methylpyrrolidone) or the like as a polar organic solvent which is arbitrarily mixed with water. ０．２0.2%, magnesium hydroxide or the like as a magnesium compound and 0.0 as MgO.
5 to 0.2% is used as the cooking liquid. Both liquid-phase cooking and gas-phase cooking are possible, but the gas-phase cooking in the PA method can obtain a very small liquid ratio of 1.5 to 2.2 L / kg without uneven boiling. Energy
Can be extremely reduced, which is preferable in preventing global warming due to carbon dioxide. Cooking is at a maximum temperature of 110 to 130
° C and the holding time is 30 to 120 minutes. The resulting unbleached pulp has an extremely low kappa value of 3 to 7, a very high Hunter whiteness of 45 to 60%, and bleaching by treatment with a Pa chemical (alkali hydrogen peroxide solution) or a Pa chemical with oxygen. A semi-bleached pulp with high whiteness is obtained. Chlorine dioxide bleaching enables chlorine-saving bleaching, and ozone bleaching enables chlorine-free bleaching. Both bleached pulp with a Hunter brightness of 80 to 92% is obtained.

Since a jute having a quality higher than ordinary quality is used for fabrics, ropes and the like, it is desired to use it for many purposes and it is difficult to collect a large amount of resources. In addition, it is much more expensive than wood chips, and the only way to use it as a raw material for pulp was to produce raw pulp for specialty high-grade paper. Conventionally, jute waste pulp has a large amount of dust and has not been used as a raw material for high quality paper. In the present invention, jute-like hemp debris is collected and P
Pulping by method A digests foreign substances such as skins, removes undigested materials and dust that are difficult to separate and remove, and carefully selects and bleaches it to give pulp with strength that can be used in place of bleached KP of softwood. Prepare a tie pulp that can be used for the production of (bagasse paper-a). The optimum conditions for pulping by the PA method are 120 to 1 which are slightly higher than the above-described bagasse cooking temperature.
The temperature is 40 ° C., but the digestion conditions and the bleaching conditions are substantially the same.

[0008] By blending straw pulp and cotton pulp, it has become possible to provide a high-quality printing paper which is 100% non-wood pulp and which has more favorable printability and texture, and a method for producing the same. In particular, the blending of straw pulp contributes to the improvement of printability, and the blending of cotton pulp contributes to the supply of high quality paper such as printing paper and writing paper having a luxurious feel.
Both of them have a small amount of addition, so that pulp by the conventional method may be used, but pulp by the PA method is more preferable from the viewpoint of quality improvement. Cooking conditions by the PA method are as follows:
Bagasse pulping conditions can be applied to straw pulp, and jute pulping conditions can be applied to cotton pulp.

[0009] The papermaking can be mixed with bagasse pulp, which can be supplied in large quantities at a low cost, at a rate as high as possible with 70 to 95%, preferably 85 to 90% (the remainder is jute pulp or cotton pulp and straw pulp). Therefore, if possible, the use of bagasse pulp having a high strength makes it possible to reduce the amount of tethered pulp used.
It is preferable to beat each separately, rather than mixing all the pulp at the same time, in order to obtain a bagasse paper having a low blending ratio of the connecting pulp and a high strength. When beaten by mixing pulp, bagasse tends to cause troubles in the paper making process, such as a decrease in freeness without a significant increase in strength even after strong beating. In any beating, it is desirable to keep the CSF at 350-650 mL, preferably at 450-550 mL. The waste jute is relatively abundant as an unused resource, and the pulp obtained by the PA method suppresses the occurrence of twisting rather than beating the strength and increases the strength to 400 to 600 mL of CSF, preferably 450 to 550 mL of CSF. It is desirable to control the process.

[0010] Straw pulp improves the surface smoothness of the paper and contributes to the improvement of printability. However, suppressing beating to a small extent can prevent a decrease in drainage in the papermaking process, so that CSF400 is used.
It is desirable to manage the process to ~ 600 mL, preferably CSF 450-550 mL.

[0011] Cotton pulp contributes to the improvement of the texture of bagasse paper for printing and is good for giving a high-grade feel. However, if the beating is not advanced, the surface of the paper may be extremely damaged.
50-500 mL, preferably CSF200-300 m
It is desirable to control the process to L.

The blending ratio of pulp obtained from waste jute as a connecting pulp is 5 to 30%, preferably 10 to 20%.
%. Straw pulp used as an auxiliary raw material has a compounding ratio of 3 to 15%, and cotton pulp has a compounding ratio of 5 to 10%.

A sizing agent, a filler and the like are usually added as a papermaking aid. The sizing agent gives the paper moderate water resistance and prevents bleeding.
Since the paper is acidified for sizing, a neutral size is preferable for enabling long-term storage of the document. The neutral sizing agent can be selected from commonly used ones such as alkyl ketene dimer and the like, and a surface size such as CMC or glue size can also be used. Filler is effective to increase the opacity of paper, especially pulp such as bagasse rice straw, which contains a lot of pentosan in the pulp used, is beaten to increase the density of the paper and increase the crispness, decrease the opacity and increase the strikethrough However, according to the present invention, the necessity of beating with the jute pulp does not proceed, so that the necessity of adding a filler is reduced. If added, add 5-40%, preferably 10-25% of China clay, talc, titanium white, etc. as filler.

Papermaking is performed by a yankee machine such as a circular net or a short net for small-scale production of thin materials. Among medium- and heavy-weight multilayer papers, a circular-mesh papermaking machine is used for mass production, and a long-sized paper is used for mass production of ordinary paper. Preference is given to mesh or twin-wire machines. Treatment with a calender or a super-cattender is effective in further smoothing the surface of the paper.

[0015]

According to the present invention, a relatively small amount of auxiliary pulp mainly composed of bagasse pulp can be obtained from unused resources in the south, and high-quality 100% non-wood pulp printing paper can be manufactured.

[0016]

Next, the present invention will be further described with reference to Examples.
The present invention is not limited by this embodiment.

EXAMPLE 1 82% bleached pulp of bagasse by the AP method of bagasse was treated with P
18% bleached pulp from Method A was used. Bagasse pulp is CSF
Beat to 530 mL and add jute pulp to CSF
Was beaten to 480 mL, subjected to neutral sizing by adding -0.3% alkyl ketene dimer combined both added 7% China clay as a filler, bagasse paper basis weight amount 55 g / m ² by Fourdrinier machine The resulting paper was further subjected to a super calendar to obtain high quality paper for printing.

EXAMPLE 2 Pulverized jute P was added to 80% bleached pulp by the bagasse PA method.
10% bleached pulp of Method A, bleached pulp of straw PA method 3
% And cotton linter-pulp 7%. Bagasse pulp is beaten to CSF 500 mL, and jute pulp is beaten to CSF 400 mL, and straw pulp is CS
F. Beat to 500 mL, cotton linter-pulp is CS
It was beaten to F150mL, subjected to neutral sizing by adding 4's alignment alkyl ketene dimer -0.3% after beating, the addition of 7% titanium white as a filler, bagasse US basis weight 45 g / m ² by Tan'ami machine Paper, calendar
To obtain high quality paper for printing.

Claims (4)

[Claims] 1. A pulp made of bagasse (sugar milled pulp) as a main component, and a pulp obtained by a jute waste PA method as an auxiliary material.
And 100% non-wood pulp high-quality paper (bagasse paper-a) characterized by using a papermaking aid as required, and a method for producing the same. 2. A jute waste PA as an auxiliary raw material pulp.
The high-quality paper according to claim 1, wherein straw pulp or cotton pulp is used in addition to the pulp of the method. 3. Straw pulp or cotton linter
3. A high quality paper and a method for producing the high quality paper, wherein the pulp is PA pulp. 4. The high quality paper according to claim 1, wherein a sizing agent and a filler are used as a papermaking auxiliary, and a method for producing the high quality paper.