JPH06184981A - Very fine lignocellulose fiber and paper product using the same - Google Patents

Abstract

PURPOSE:To improve opacity and rigidity of paper by using specific fine lignocellulose fiber obtained from wood and nonwoody material as raw material of paper. CONSTITUTION:Fine lignocellulose fiber is obtained from wood and nonwoody material as raw matefial of paper, has fiber length to pass through the standard sieve having the eye of a sieve of 106mum, 80-250 Kappa-No prescribed by JIS-Z-8211 and 20-200% water retention value prescribed by J. TAPPI No 26. A paper product comprises the fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fine lignocellulosic fibers obtained from wood and non-wood, and more particularly to a lignocellulosic fiber which improves the opacity, smoothness and stiffness of paper when contained in paper. It relates to cellulose fibers.

[0002]

2. Description of the Related Art Conventionally, as a method for producing lignocellulosic fibers from wood and non-wood, mechanical pulping methods such as GP, RGP and TMP obtained by treating wood and non-wood as materials as grinders or refiners. Alternatively, there is known a chemical mechanical pulping method such as CGP or CTMP obtained by treating wood and non-wood with a chemical (sodium sulfite or sodium hydroxide) and subjecting them to mechanical treatment such as refiner. The wood and non-wood used in these pulping methods are fresh ones in order to facilitate single fiber formation. Also, GP
In case of, log is used, RGP, TMP, CGP, CT
MP is a small piece (thickness of 4 to 10 mm, width of around 25 mm, fiber length of 15
Up to 35 mm).

Generally, the lignocellulosic fibers obtained by the mechanical pulping method and the chemi-mechanical pulping method have many long fibers and binding fibers as compared with ordinary chemical pulp, and have a high opacity and acceptability of printing ink. It is used exclusively for the newspapers and medium-quality paper that are needed. However, it is the fine fiber fraction of the lignocellulosic fibers that contributes to the opacity and the acceptability of the printing ink, and the long fiber fraction hardly contributes.

As described above, most of the above-mentioned lignocellulosic fibers contain long fibers or binding fibers, and if they are put in paper as they are, they have the drawback of deteriorating the smoothness and the surface condition of the paper. Therefore, in practical use, although measures such as making fibers fine by appropriate refiner treatment etc. are taken, quality such as paper strength, opacity, and smoothness is comprehensively made high quality. From the standpoint of maintenance, the actual situation is that only unsatisfactory results have been obtained. Further, generally, as a method of increasing the opacity of paper, there is a method of using an internal filler for papermaking such as talc, clay, calcium carbonate, titanium oxide, etc. Therefore, it is difficult to obtain a bulky and lightweight paper product, and the paper stiffness becomes weak.

[0005]

From the actual situation as described above,
The inventors of the present invention have made earnest studies on a paper raw material for obtaining a product that is excellent in opacity and smoothness and has a strong stiffness as a lightweight paper. As a result, of the lignocellulosic fibers obtained from wood and non-wood, if a specific fiber content is used as a paper material, it is possible to obtain a paper product that maintains high-quality paper quality without degrading the quality as described above. Was found.

[0006]

The present invention provides a fine lignocellulosic fiber obtained from wood and non-wood, comprising:
The length of the fiber is the length of the fiber that passes through a standard sieve having an opening of 106 μm defined by JIS-Z-8801, and the Kappp of the fiber defined by JIS-P-8221.
a-No. is 80 to 250 and J. TAPPI No.26
It is a paper product obtained by blending the fine lignocellulosic fibers and the fine lignocellulosic fibers characterized by having a water retention of 20 to 200%.

[0007]

The wood and non-wood used in the present invention are not particularly limited. For example, mechanical pulp (hereinafter referred to as MP), chemi-mechanical pulp (CM
P), logs and chips used for kraft pulp (KP), chip dust (5) commonly used as fuel
(Passage of chip screen of ˜6 mmφ), sawdust, etc., and reject of MP, CMP's screening process, etc. are exemplified, and wood and non-wood fibers containing lignin may be used. However, it is more economical to use chip dust, sawdust, etc., which are closer to waste, or the reject of the scouring process of MP or CMP, rather than using expensive raw materials used in MP, CMP, KP, and resources. It is also a preferred embodiment from the viewpoint of protection and environmental destruction.

As a method for obtaining fine lignocellulosic fibers from wood and non-wood, a method using a combination of acid hydrolysis and mechanical treatment (milling, crushing, classification, etc.) or mechanical treatment (milling, milling, There is a method only by crushing, classification, etc.). However, since only a mechanical treatment consumes an extremely large amount of electric power, a method using both acid hydrolysis and mechanical treatment is a preferable method from the viewpoint of energy saving.

In the present invention, fine lignocellulosic fibers obtained by the above method (hereinafter referred to as fine fibers)
Among them, as will be described in detail below, the fiber content that simultaneously satisfies the three requirements is specified.

First, the fiber length is JIS-Z-8801.
It has a fiber length that has passed through a standard sieve having an opening of 106 μm as defined in. By the way, opening 106μ
A large amount of bundled fiber pieces remained in the residue of the standard sieve of m, and when used as a paper raw material without classification, the bundled fiber pieces cause the deterioration of the smoothness of the paper surface remarkably. Let On the other hand, there are almost no binding fiber pieces in the fine fibers that have passed through the standard sieve having an opening of 106 μm, and when used as a raw material for paper, the smoothness of the obtained paper surface is higher than that when not used. The decrease in is very small.

Second, the above-mentioned fine fiber Kappa-N.
o (JIS-P-8221) is 80 to 250. Kappa-No here is an index showing the amount of lignin in the fiber, and the higher the value of Kappa-No, the greater the amount of lignin. By the way, when using it as a raw material for paper,
When Kappa-No is less than 80, the effect of improving the opacity of the paper is small, while when it exceeds 250, the hydrolysis of the cellulose component in the fine fibers proceeds excessively, and the strength of the paper decreases, which is not preferable. Therefore, in the present invention, the effect desired by the present invention can be efficiently achieved by using the fiber length of the fine fiber and the Kappa-No specified as described above.

The Kappa-No of the fine fibers can be adjusted by appropriately selecting the treatment conditions in the step of acid hydrolysis or delignification of the fine fibers. For example, when it is desired to increase Kappa-No, the treatment conditions for acid (hydrochloric acid, sulfuric acid, etc.) hydrolysis are strengthened, that is, the acid concentration is increased, the treatment temperature is raised, or the treatment time is lengthened. The objective can be achieved by increasing the hydrolysis degree of hemicellulose or cellulose in non-wood and increasing the elution amount of hemicellulose or cellulose. In this case,
Since there is almost no effect on lignin, the amount of lignin is relatively large, resulting in a high Kappa-No. On the other hand, when it is desired to lower the Kappa-No, it can be adjusted to the required Kappa-No by delignification treatment using cooking or bleaching chemicals used in the production of chemical pulp, and adjusting the conditions as appropriate. . In this case, on the contrary to the above case, there is little influence on hemicellulose and cellulose, and as a result, Kappa-N
o will go down.

Further, as a third, the fine fibers of J.
Water retention specified in TAPPI No. 26 is 20-200
Be in the range of%. The water retention here is an index showing the degree of swelling of fibers, and the larger the value, the greater the degree of swelling of fibers and the worsening the drainage.
On the other hand, when used as a raw material for paper, the strength of paper increases. Incidentally, when it is used as a raw material for paper, if the water retention is less than 20%, the paper strength is greatly reduced. On the other hand, 200
%, The paper strength is not significantly reduced, but there is concern that productivity and dryness may decrease due to a decrease in drainage in the paper making process, and further decrease in dryness in the production process of fine lignocellulosic fibers. There is concern about deterioration of sex, power consumption, and increased steam consumption.

As a method for adjusting the water retention of the fine fibers, the object can be achieved by appropriately selecting the treatment conditions for hydrolysis with an acid. For example, if you want to increase the water retention, acid (hydrochloric acid, sulfuric acid, etc.)
The concentration can be adjusted by reducing the concentration, lowering the treatment temperature, or shortening the treatment time. On the other hand, in the case of lowering the water retention, the object can be achieved by appropriately selecting conditions opposite to the above method. By the way, the water retention of the fraction that passes through the sieve of MP or CMP fiber having an opening of 106 μm or less and stays on the sieve having an opening of 45 μm is 250% or more. Also in this case, the acid hydrolysis conditions as described above may be appropriately used. By selecting, fibers having the required water retention can be obtained.

The whiteness of the fine fibers is not particularly limited and may be appropriately selected according to the target quality. For example, when it is desired to increase the whiteness, it may be bleached with hydrogen peroxide or sodium peroxide known as lignin storage bleaching.

The fine fibers thus obtained are used as pulp fibers for papermaking, for example, 5 to 30% by weight based on the total pulp fibers.
When blended in a range of about the range, an excellent paper product can be provided without deteriorating the paper quality such as opacity, smoothness, or paper stiffness (stiffness) of the obtained paper.

[0017]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in an example show a weight part and weight%, respectively.

Example 1 Hardwood chip dust was treated by passing it through a standard sieve having an opening of 2 mm, and the chip dust remaining on the sieve was subjected to an acid hydrolysis treatment (liquid ratio 1:10, H ₂ SO ₄ concentration: 1 N, temperature: 85). ℃, 2
After that, wash with water, neutralize with sodium hydroxide, and dry. The dried product was pulverized with a Willey mill, and the pulverized product was treated by passing it through a standard sieve of JIS-Z-8801 having an opening of 106 μm to obtain a finely pulverized product that passed through the sieve. Next, 5% hydrogen peroxide, 4% sodium hydroxide, 3% sodium silicate, and 0.05% magnesium sulfate were added to the solid content of the finely ground product to give a finely ground product concentration of 10%.
%, The temperature was 70 ° C., bleaching was performed for 3 hours, bleaching was followed by washing with water to obtain fine lignocellulosic fibers. Kappa-No of this lignocellulosic fiber is JIS-P-8.
211, and the water retention is set to J. TAPPI No.26
Was measured according to, and the obtained results are shown in Table 1.

10 parts of the above fine lignocellulosic fibers and 90 parts of LBKP having a freeness of 500 ml were mixed, and a retention aid (trade name; DC-4 / Missawa Ceramic Chemical Co.) was added to this pulp slurry for absolutely dry pulp. 0.02% is added and the basis weight is 60g using a handmade machine.
A sheet of / m ² was prepared.

Example 2 Sawdust was shaken with a standard sieve having an opening of 1 mm, and the sawdust remaining on the sieve was subjected to acid hydrolysis treatment (liquid ratio 1:10, H ₂ SO ₄ concentration:
(4 N, temperature: 80 ° C., 3 hours), washed with water, neutralized with sodium hydroxide, and dried. The dried product was pulverized with a Willey mill, and the pulverized product was treated by passing it through a standard sieve of JIS-Z-8801 having an opening of 75 μm to obtain a finely pulverized product that passed through the sieve. Next, 5% of hydrogen peroxide, 4% of sodium hydroxide, 3% of sodium silicate, and 0.05% of magnesium sulfate were added to the solid content of this finely ground product,
The finely pulverized product was bleached for 3 hours under the conditions of a concentration of 10% and a temperature of 70 ° C., and after bleaching, it was washed with water to obtain fine lignocellulosic fibers. Kappa-No and water retention of this lignocellulosic fiber were measured in the same manner as in Example 1, and the obtained results are shown in Table 1.

10 parts of this fine lignocellulosic fiber and 90 parts of LBKP having a freeness of 500 ml were mixed, and a retention aid (trade name; DC-4 / Missawa Ceramic Chemical Co.) was added to this pulp slurry for absolutely dry pulp. 0.
Add 02% and use a handmade machine to weigh 60 g / m 2.
Created ² sheets.

Example 3 CGP screen meal was treated with acid hydrolysis (liquid ratio 1: 1).
(0, H ₂ SO ₄ concentration: 0.5 N, temperature: 70 ° C., 2 hours), then washed with water, neutralized with sodium hydroxide, and dried. The dried product was pulverized with a Willey mill, and the pulverized product was treated by being passed through a standard sieve of JIS-Z-8801 having an opening of 45 μm to obtain a finely pulverized product that passed through the sieve. Next, 5% hydrogen peroxide, 4% sodium hydroxide, 3% sodium silicate, and 0.05% magnesium sulfate were added to the solid content of the finely ground product to give a finely ground product concentration of 10%.
%, The temperature was 70 ° C., bleaching was performed for 3 hours, bleaching was followed by washing with water to obtain fine lignocellulosic fibers. The Kappa-No and water retention of this fiber were measured, and the obtained results are shown in Table 1.

10 parts of this fine lignocellulosic fiber was mixed with 90 parts of LBKP having a freeness of 500 ml, and a retention aid (trade name; DC-4 / Misawa Ceramic Chemical Co.) was added to this pulp slurry for absolutely dry pulp. 0.
Add 02% and use a handmade machine to weigh 60 g / m 2.
Created ² sheets.

Example 4 As a pretreatment for bleaching with hydrogen peroxide in Example 1, 3% of sodium chlorite was added to the solid content of the fine fiber pulverized product, and the pH was adjusted to 4 with acetic acid at a temperature of 60. A fine fiber pulverized product (fine lignocellulosic fiber) was obtained in the same manner as in Example 1 except that the treatment was carried out at 0 ° C. for 3 hours and the treatment was followed by washing with water. The Kappa-No and water retention of this fiber were measured, and the obtained results are shown in Table 1. 10 parts of this fine fiber and freeness 5
A mixture of 90 ml of LBKP (00 ml) and a retention aid (trade name; DC-4 / Misawa Ceramic Chemical Co., Ltd.) was added to the obtained pulp slurry in an amount of 0.02% based on the absolutely dry pulp.
A sheet having a basis weight of 60 g / m ² was prepared by using a hand-making machine.

Comparative Example 1 Kappa-was carried out in the same manner as in Example 1 except that a standard sieve of JIS-Z-8801 having a mesh size of 106 μm was used for the treatment, and the pulverized material present on the sieve was used as fine fibers.
No and the degree of water retention were measured to prepare a sheet.

Comparative Example 2 The condition of the acid hydrolysis treatment in Example 2 was H ₂ SO ₄ concentration of 1.
0 N, temperature: 90 ° C. A pulverized product was obtained in the same manner as in Example 2 except that the Kappa was obtained in the same manner as in Example 2.
-No and water retention were measured and a sheet was prepared.

Comparative Example 3 A pulverized product (fine fiber) was obtained in the same manner as in Example 1 except that sulfite pulp having a Kappa-No of 50 was used.
Kappa-No and water retention were measured in the same manner as in Example 1, and 10 parts of the pulverized product and LB having a freeness of 500 ml were measured.
A sheet was prepared in the same manner as in Example 1 except that 90 parts of KP was mixed.

Comparative Example 4 A sheet was prepared in the same manner as in Example 1 except that LBKP having a freeness of 500 ml was used as fine fibers, Kappa-No and water retention were measured in the same manner as in Example 1, and 100 parts of LBKP was used. It was created.

Comparative Example 5 A sheet was prepared in the same manner as in Comparative Example 4 except that talc (paper ash content 10%) was added as a papermaking filler in the preparation of the pulp sheet.

Comparative Example 6 Bleached CTMP (whiteness: 82%) was sieved to JIS.
-Passed through a standard sieve of Z-8801 having an opening of 106 μm,
A fine fiber retained on a standard sieve having an opening of 45 μm was obtained.
About this fiber, Kappa-in the same manner as in Example 1.
No. and water retention were measured, and 10 parts of this fine fiber was mixed with 90 parts of LBKP having a freeness of 500 ml, and otherwise a sheet was prepared in the same manner as in Example 1.

The thus obtained 10 kinds of sheets were subjected to a paper quality test based on the following evaluation method, and the obtained results are shown in Table 1.

[Opacity] Measured according to JIS-P-8138 (%).

[Beck smoothness] It was measured according to JIS-P-8119 (second / 10 cc). The larger the value, the better the smoothness.

[Tear length] Measured according to JIS-P-8113 (Km).

[Stiffness] J. TAPPI-No. Measured according to 40 (mg). The larger the value, the stronger the paper stiffness.

[Water retention] J. It was measured according to TAPPI No. 26 (%).

[Drainage] The dehydration time of the raw material on the wire (150 mesh) at the time of making a sheet having a weight of 60 g / m ² was measured (second). The larger the value, the poorer the drainage.

[0038]

[Table 1]

[0039]

As is clear from the results of Table 1, when the fine lignocellulosic fibers obtained according to the examples of the present invention are used as a raw material for paper, smoothness, opacity, and breaking length (paper strength) ) And paper quality, etc.
We were able to obtain high-quality paper products.

Claims (2)

[Claims] 1. A fine lignocellulosic fiber obtained from wood and non-wood, wherein the length of the fiber is JIS-Z-
The length of a fiber passing through a standard sieve having an opening of 106 μm defined in 8801, and JIS-P-82 of the fiber.
11, Kappa-No. 80 to 250 and J.P. Water retention specified in TAPPI No. 26 is 20-
A fine lignocellulosic fiber characterized by being 200%. 2. A paper product obtained by blending the fine lignocellulosic fibers according to claim 1.