JPS5947492A - Modification of bagasse pulp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND ART The use of corn fiber (bagasse) as a raw material for nof-ruzo has attracted interest for many years.

Bagasse pulp is currently only used to a limited extent in some papermaking processes, but if the original properties of bagasse fiber can be adapted to the requirements of the final product,
Most of the bagasse N paper shields will help satisfy the huge demand.

Various methods have been proposed for this purpose. For example, 2 US patents! No. 41,864.985 teaches a method for producing cellulose in which corn fibers are first treated with a refined sulfuric acid solution and then with an alkaline solution.

U.S. Pat. No. 1,918,250 teaches a method for producing cellulose containing alpha cellulose with a modulus of 95 or higher from corn fibers, according to which the corn corn fibers are Treated with acid at temperatures above 98°C and pressures above atmospheric pressure, washed with water, and then heated to approximately 100°C.
Temperatures above 0.degree. C. are treated with an alkaline solution having a pressure above atmospheric pressure.

U.S. Pat. No. 1,931,575 teaches a method for producing cellulose from corn fibers, according to which corn fibers are treated with acid for 21y and then heated to about 100°C or above. Alkaline treatment is performed at a temperature above 1 degree or more.

US Pat. No. 6,620,911, for example.

The authors teach a method for producing Lg from non-woody lignocellulosic plant materials such as corn bagasse, which involves the steps of wetting the fibers to form an aqueous slurry, shredding the slurry and demyelinating the fibers. A step of separating the pith and fibers by screening, a step of partially dehydrating the separated fibers, a step of macerating the fibers in an alkaline hydric acid solution for a sufficient time to loosen the fibers, and a step of high temperature and high pressure (660 to 580' F (
approx. 165°C to 177°C) and 100 to 150ps1g (
It consists of a series of steps in which the fibers are digested in an alkaline solution at a temperature of about 7-10 g/cm2G).

U.S. Pat. No. 4,250,452 teaches a method for producing gurugu from corn fiber bagasse, which involves a wet brachial process of the raw corn-pressed bagasse, its partially demyelinated the process of storing bagasse in a wet state;
The process of making an aqueous suspension, per 100 parts of alkali metal, magnesium, calcium or aluminum carbonate, sulfite, hydroxide, phosphate, phosphite, chlorate or hypochlorite. The process of wet-shaping by applying water pressure while adding 0.5 to 10 parts of water, and converting the wet-shafted bagasse into a pulp by biochemical treatment with neutral sulfite or thermal-mechanical disintegration. The process consists of a step of mechanically converting the Paga sparg into a 4'-lupe, a washing step, a screening step, and a step of dehydrating the PAG.

However, both the above processing method and other methods are
The relationship between the content of hemicellulose and the bonding strength of the fibers in Pagasuno 9 Lup was not investigated at all.

The suitability of bagasse as a raw material for producing certain paper products such as decorative paper would be greatly increased if a method were available to properly remove the hemicellulose component of the fibers.

(Summary of the Invention) The present invention mainly relates to a method for modifying bagassepar f, which method comprises: (a) using an alkaline treatment liquid having a hydroxyl ion concentration of about 5 to 50 grams per 1];
The process consists of the steps of: slurrying the ketebagasparg at a temperature between 100 DEG C. and 100 DEG C. for a sufficient period of time to dissolve at least some of the hemicellulose component; and (b) separating the pulp from the treatment liquid.

It has been found that the content of hemicellulose in the pulp directly affects the bond strength of the bagasse fibers, which in turn directly affects the properties of products made from the pulp. In particular, it has been found that by appropriately reducing the hemicellulose content of Pagasparzo, the flexibility of the final paper product is improved. Although it has long been known that hemicellulose is soluble in alkaline solutions, the positive effect its removal has on the properties of the final paper product was not understood. For the purposes set forth in the Mizuhiki, the term 'Nonrupu' refers to arm stem bagasse MIM that has been cooked in a full caustic cooking solution and the fibers separated. This cooking process is conventionally known and is generally
A cooking solution having a hydroxyl ion concentration of about 20 to 80 grams per serving is used at about 150 to 200° C. for about 10 to 30 minutes. In this treatment method, the hemicellulose contained therein is insufficiently dissolved because the cooking temperature is too high to dissolve it. On the contrary, a chemical reaction takes place, whereby the hemicellulose component is not hydrolyzed and removed.

The concentration of hydroxyl ions in the treatment method of the present invention is about 5 to 50 grams per part. Increasing the hydroxyl ion concentration increases the removal rate and amount of hemicellulose.

If the concentration is less than 5 grams per 1, it is considered that the concentration is too low to produce any substantial effect, and if the concentration exceeds 50 grams per 1, there is no functional problem. It is considered that 0 is unnecessary. Hydrogen imen is preferably obtained from a sodium hydride solution because it is easily available and inexpensive. However, other alkali hydroxides can also be used. The preferred concentration of sodium hydroxide is 80 grams per hour.

1 As the grade increases, the solubility of hemicellulose decreases, so the effect gradually decreases at temperatures exceeding 60°C.
The treatment temperature can be from 0°C to about 100°C. 1
When the temperature exceeds 00°C, the strength of the treated fiber becomes lower than the allowable value. On the other hand, if the temperature is lower than 20° C., cooling is required, which is not practical from a Western point of view. Therefore, the temperature is about 20~
60°C is advantageous, and tMA II is approximately 30°C.
is preferred.

A further feature of the invention is the method of preparing processed 1 and 9 ruzo. This method comprises: (a) slurrying demyelinated bagasse fibers with an alkaline vaporized M% solution having a hydroxyl ion concentration of about 20 to 80 grams per part at a temperature of about 150°C to 200°C for about 10 to 50 minutes; (b) washing the cooked fibers with water to remove the cooking liquor and M decomposition components; (c) adding about 5 to 5 parts per part of the heat-treated fibers;
slurrying with an alkaline treatment solution having a hydroxyl ion concentration of 0 grams at a Y blackness of about 0° C. to 100° C. over a sufficient period of time to dissolve at least some of the hemicellulose fiber component of the pulp; and (d) treatment. and separating the treated fibers from the liquid.

The present invention will be explained in further detail in I]11 with reference to the drawings.

FIG. 1 represents the general processing steps used to carry out the integrated bagasse fiber processing of the present invention. In total, about 1 ton of non-detectable bagasse solp is produced in the process according to the invention from about 2.3 tons of Pubber fibers. Starting from the preparation of the cooking solution, the black liquor from the water washing process is circulated to the evaporation process and most of the water is removed. The evaporation can be suitably carried out in a conventionally known multi-stage evaporator.6 The resulting residual composition contains the chlorinated material after one reaction and various organic compositions, these compositions being shown in the figure. It burns to generate the heat needed for the evaporation process.

The combustion residue or ash Fi (mainly sodium carbonate and sodium sulfide) reacts with water, calcium chloride, sodium hydroxide and even sodium carbonate to regenerate cooking liquor. Typically, the cooking liquor contains about 100 grams per liter of sodium hydroxide and a significant amount of sodium sulfide as a residue from the kraft pulping process. ~90
It is ℃. The cooking liquor is then stored in a suitable container and subjected to the general use of the cooking liquor of the present invention.

Fresh cooking liquor is introduced into the cooker 1 along with the arm shaft fibers to form a pressurized slurry. ) The raw material fiber is typically corn raw material, which is crushed to remove the liquid 7-yosaccharide-containing components, and then mechanically processed to remove the pulp and fibers, leaving behind the fibers. It has been removed. If the cooking rate is -1, then it will be operated continuously.

A fiber slurry with a cooking weight of 1 contains about 15 to about 60 parts by weight of fiber depending on the strength of the cooking liquor. The residence time is about 5 to 30 minutes, preferably about 20 minutes. The slurry temperature is about 150 to 200°C, preferably about 170°C.

The pressure is about 50 to 150 ps/g (about 5.5 to about 10
．． 5/C1nG). As a result of the cooking process, the bagasse fibers separate from each other and become suitable for use as pulp. After cooking, the resulting pulp is washed with water to remove and collect the spent cooking liquor (thin black liquor) containing dissolved organic matter.

This liquid is returned to the evaporation process to produce a vaporized liquid.

As already mentioned, the thin black liquor contains not only the alkali metals to be recycled, but also various organic compounds extracted from the pulp.

In this stage 1 ago, /4' Lupu Aya Ila had a relatively large amount of (
(approximately 15-20%) hemicellulose, which increases the bonding strength of the fibers. Due to this characteristic,
The final paper product produced from such paper is strong, but also hard.

This is undesirable for many paper products, such as decorative paper, where flexibility is a critical product characteristic. Therefore, it is necessary to appropriately remove hemicellulose and reduce the bond strength to the desired strength.

Therefore, the i4 is also washed with water? The hemicellulose content of the fibers is reduced by slurrying the hemicellulose content of the fibers, thereby reducing the hemicellulose content of the fibers. Controls the strength of the bond.

Preferably, the slurry is formed at an ambient temperature, usually about 30°C. In this case, the fiber concentration is about 1 to 25 i.

Preferably, the processing liquid is the same as the cooking liquid and is supplied from a common source as shown by the dashed line. Instead of this,
As the processing liquid, a liquid other than the cooking liquid may be supplied from another source.

As previously mentioned, the processing solution generally consists of an aqueous alkaline solution of about 5 to about 50 grams of hydroxide ion ltl K per ton. Alkalinity is water 1. Preferably it is provided by the presence of an alkali gold 44 hydroxide such as sodium -44ide, but any other soluble one with hydroxide ions is also suitable.

After this treatment step, the treatment liquid is separated from the treatment/zero and returned to the steam P+4 step. This allows the required amount of fresh cooking liquor to be reduced. process·! The rug is then sent to a conventional bleaching process.

Instead of the above method, if necessary, cook, wash,
The serp may be bleached prior to the above treatment steps. However, this mode of operation is not preferred. That's t
This is because the processing method of the present invention reduces the cost of IS' and white chemical products that are later processed. Therefore, bleaching before alkaline treatment will not take advantage of this advantage.

Figure 2 6r shows the effect of working temperature and hydroxyl ion concentration on the burst strength of treated bagasse fibers.

As shown by the curve, the bursting strength of the fiber 11 decreases as the hydroxyl ion 0 degree increases.

Tomo et al., i7A has relatively little influence as the temperature rises, and actually peaks at about 60°C. Therefore, the concentration of hydroxyl ions is the most important hardness factor to reduce and control the strength of carbon fibers, and this stiffness is inversely related to the softness imparted to the final paper product. have.

Therefore, by reducing the burst strength of the bagasse fibers by the treatment of the invention, the flexibility of the final printed product, such as decorative paper, is increased.

(Description of '4 Example) Example 1: Removal of Hemicellulose To illustrate the effect of the hydroxide ion treatment of the present invention, two oven-dried Nonogas-Yalp specimens were heated at 30°C for 70°C.
Slurried with y/L and 80f//- of NaOH, respectively. The pulp concentration was 3% by weight. The alkaline slurry was stirred for 50 minutes, centrifuged for 50 minutes, and then thoroughly removed from the filtrate. Next, the pulp was washed with water five times. In this case, after each water wash, the Zerp was slurried to a tertiary concentration and then centrifuged. Finally, slurry the washed water with water to a concentration of 6%, and
The concentration was adjusted to 6.5 with Hf502 to neutralize all remaining sodium hydroxide. Next, the amount of hemicellulose in the obtained sample was analyzed. , the results are shown in Table 1.

Table 1 Control material 17.55 70 f/l NaOH treatment 8!9.34809/LNa
OH treatment 4.84 This result is 709/1
Figure 3 illustrates how the hemicellulose content of treated Norg is reduced by the treatment of the present invention at levels of NsOH and 80 f/1 NaOH. As shown therein, the higher the concentration of hydroxyl ions, the more hemicellulose is removed.

Example 2: Handsheet Testing To directly illustrate the effect of the treatment of the present invention on a paper product, a decorative handsheet was prepared using treated i4 gas Zorg and untreated bagasse. They were compared in terms of flexibility, smoothness, and burst strength.

That is, it has a basis weight of about 2 grams [7,8 inches (
A square piece of paper (approximately 20 cm) was prepared. The manufacturing method of handmade paper is the same as that of TAPPI processed paper 200 os-70 and 7205 m-58. However, the handmade paper t; 1. It was pressed between two blocks without pressing between one block and a chrome-clad steel plate. ζ
In addition, each of the handmade papers was steam-dried [7] to quickly produce samples. Next, the flexibility and smoothness of the obtained handmade paper were subjectively tested, and the bursting strength' (f
-rA+ thrifty. Bursting strength i, J:, TAPPl treatment T
220 rn -60 and T 403 t s -6
-3. The customer-like trial of the handmade paper was not conclusive. The reason for this is the basic H of handmade paper (heaviness and correspondingly high rigidity,
This is because it deviates from the range normally encountered in actual decorative paper testing, and therefore the samples cannot be compared. However, the differences in fIA vermilion softness and smoothness, which were evaluated by a highly skilled and experienced Keller who compared the samples with each other, were extremely ↓C4. Table 2 shows the 4 of each group.
Among the four samples, those rated 4 represent the best among the four samples, and those rated 7.1 represent the best among the four samples.
Represents the worst of the four trials.

=, 1i: For softness, lay out handmade paper on a flat surface, spread your fingers f on the handmade paper, and spread your hands with the palms facing down 1: ↑
I made the decision. Then he drew his fingertips and drew the paper into the space of his palm, crumpling it with repeated strokes. In order to evaluate the flexibility of each sample, we simultaneously evaluated the weakness and surface texture of each sample. This review was done relatively.

Relative smoothness was determined by placing handmade paper on a flat surface and lightly rubbing the surface of the paper with your fingertips.

The results of this test are listed in Table 211 and show that the flexibility and smoothness of the final decorative paper product can be improved by using bagasse fibers treated according to the force method of the present invention. It is clear that it is possible to expand

Please note that the above examples are merely illustrative and should not be construed as limiting the scope of the invention as claimed. I have free time≧I want to have free time.

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[Brief explanation of the drawing]

'7f, Figure 1 is a flowchart of the general process steps used to carry out the fiber treatment according to the present invention.
, and FIG. 2 is a graph showing the influence of sharpness and hydroxyl ion concentration on the bursting strength of processed bagasse fibers.

Claims (1)

[Claims] (1) A method for reforming bagasse/9rug, comprising (a)
Approximately 0.0
Canopy from ℃ to 100℃! (b) separating the pulp from the treatment liquid; and (b) separating the pulp from the treatment liquid. Method. (2) The pulp is slurried by the alkaline processing liquid over a period of about 10 seconds to about 60 minutes.
The method according to the above item 1, wherein the method is on standby. (3) The method according to item 2, wherein the /4'rude is slurried for about 20 to about 30 minutes. (4) The method according to item 1, wherein the Y blackness is about 20°C to 60°C. (5) The pulp is bleached! ? The method described in the above item 1, in which the amount is ¥. (6) A above? Lugusurari is about 1 to about 25 re
It is a sign that it contains Wrchi's No4rupu ^
1 (method described in paragraph 2191) (method for modifying bagasse puff 1.)
Approximately 100 grams of hydroxide Sui Liu!・Up to the alkaline processing solution containing *i! Slurry for about 5 minutes to obtain a slurry containing about 10 parts of pulp; Old 1
Zumi no Chon Tatsu fF is characterized by being equipped with an upper pusher that
l) Where! Atte, (8)
) About 2 demyelinated bagasse fibers per 1
, #: J80g ÷ Hydroxyl ion - L'L7) In a potash cooking liquor, heat from about 150°C to about 20°C [1°C] for about 10 to about 30 minutes. . ■ - With culm. (b) washing the steamed M transverse fibers with water to separate the cooking liquor from the components dissolved in Part 1; (c) The digested fibers are slurried with an alkaline treatment solution having a hydroxyl ion concentration of about 5 to 5 grams per part at a temperature of about 0°C to about 100°C for a sufficient period of time to form a slurry of the above-mentioned No. a step of dissolving at least a certain amount of hemicellulose IjR; (d) A method comprising the step of separating the treated fibers from the treatment liquid to obtain treated bagasse pulp with a reduced content of mycellulose. (9) The method according to item 8 above, characterized in that washing water and cooking liquor are circulated and the ash is recovered. 9. The method according to item 8, characterized in that α1 cooking liquor is used as the treatment liquid. (Decorative paper made of bagasse fibers containing less than 111,151 hemicellulose components.) Bagasse fibers produced by the method of item 11 above. 0 Bagasse fibers produced by the method of item 947 above.
Luso. θ→ A bagassino mother produced by the method described in Section 8 above.