JP2763853B2 - Bacterial cellulose-containing paper and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to paper containing cellulose (bacterial cellulose) produced by microorganisms and a method for producing the same. More specifically, the present invention relates to a bacterial cellulose-containing paper which has excellent drainage during papermaking and has an increased amount of bacterial cellulose, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, bacterial cellulose has been actively studied as a raw material for paper instead of wood pulp from the viewpoint of forest protection or as an additive for imparting various functions to paper.

[0003] When the bacterial cellulose is contained in the paper, it is characterized by an improvement in the mechanical strength as disclosed in JP-A-62-36467, and by an increase in the mechanical strength as disclosed in JP-A-63-2636.
There are improvements in opacity and strength as disclosed in JP-A-95793, and improvements in the yield and formation of filler and fine fibers as disclosed in JP-A-1-246495. It is greatly expected as an additive that imparts functions.

[0004]

By the way, in a paper made from a pulp slurry containing bacterial cellulose obtained by the prior art including the above-mentioned method, a decrease in drainage and an increase in water retention in the papermaking process are required. As a result, it is difficult to increase the content of bacterial cellulose because of the decrease in squeezing water.

[0005] In order to use bacterial cellulose as a raw material for paper instead of wood pulp, it is necessary to increase the content of bacterial cellulose, thereby improving the problem of reduced drainage and increased water retention due to the content of bacterial cellulose. There is a need.

That is, an object of the present invention is to provide a bacterial cellulose-containing paper having improved drainage in a papermaking process and a method for producing the same.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object. As a result, it has been found that the use of bacterial cellulose obtained by the aeration and stirring cultivation method without disintegration improves the drainage in the papermaking process, and the present invention has been completed.

[0008] That is, the present invention provides a bacterial cellulose-containing paper containing an undisintegrated product of bacterial cellulose obtained by aeration and agitation culture, and a paper stock suspension without disintegration treatment of a bacterial cellulose obtained by an aeration and agitation culture. This is a method for producing bacterial cellulose-containing paper by adding it to a liquid and forming the paper.

The aeration and agitation culture method of the present invention is a culture method in which a gas containing oxygen is aerated in an agitation tank such as a jar fermenter or a tank from the upper surface, the lower surface, or the side surface. A culture method using a stirred tank,
Including shaking culture method, vibration culture method and the like.

[0010] Bacterial cellulose obtained by the stationary culture method is in a gel state, and it is difficult to add it to a stock suspension to make paper.

Observation with a microscope of the undisintegrated bacterial cellulose obtained by the aeration culture method of the present invention reveals that a large number of rugby ball-shaped ones having a major axis of 0.05 to 0.5 mm are contained. is there.

The bacterial cellulose obtained by the aeration stirring culture method of the present invention is pulp, organic synthetic fiber,
It may be cultured together with other fibrous materials such as inorganic synthetic fibers, inorganic fillers, whiskers and the like. The bacterial cellulose may be chemically modified such as methylated or acetylated.

In order to separate bacterial cellulose obtained from the culture solution by aeration and agitation culture, methods such as centrifugation and filtration can be used. The bacterial cellulose obtained by the separated aeration stirring culture method is preferably washed with water or an aqueous solution of an acid, an alkali, a detergent, a bleach or the like.

The amount of the undisintegrated bacterial cellulose obtained by the aeration stirring culture method to the stock suspension can be varied depending on the use of the paper and is not particularly limited. However, due to the properties of the obtained bacterial cellulose-containing paper, the amount of bacterial cellulose non-disintegrated obtained by the aeration and stirring cultivation method for the stock suspension may be 50% or less (on a dry solids weight basis). preferable.

When the undigested bacterial cellulose is used by mixing with pulp fiber, it is preferably added in a step subsequent to the step of beating the pulp.

[0016]

The present invention will be described in more detail with reference to the following Examples, which do not limit the present invention.

[0017] Examples and flask cultures fructose 40 g / L of Comparative Examples 1 and 2 bar click Terrier cellulose, potassium phosphate monobasic 1.0 g /
L) Magnesium sulfate 0.3 g / L, ammonium sulfate 3 g / L) Bacto-peptone 5 g / L) 1.4 ml of lactic acid
/ L, 100 ml of a basic medium having a starting pH of 5.0 was placed in a 750 ml Roux flask and the cellulose-producing acetic acid bacteria Acetobacter sp.
1 ml of cryopreserved bacterial solution of 1 (FERM BP-4545 )
Was inoculated, and statically cultured at 28 ° C. for 3 days in a constant temperature incubator. After the seed culture, the Roux flask was shaken well, and then the contents were filtered with a gauze under aseptic conditions to separate cellulose fragments and cells. Next, 1 at 10,000 rpm
The mixture was centrifuged for 5 minutes to separate the medium component and the cells (+ microcellulose), and the cells (+ microcellulose) were washed with sterile physiological saline once or twice, and centrifugation was repeated.
A required amount of sterile physiological saline was added to the washed cells, and after stirring, this was used as a seed cell solution.

Aeration and agitation culture Next, 7.5 ml of the seed bacterial solution was added to 67.5 m of the above basic medium.
1 was inoculated into a baffle flask having a capacity of 300 ml. Using a shaking incubator, amplitude 2cm, rotation speed 180r
The culture was performed for 4 days while rotating and shaking at 28 ° C. and pm. After the solid components in the flask were washed with water to remove the medium components, the cells were treated in a 1% aqueous NaOH solution at 110 ° C. for 20 minutes to remove the cells, and the cellulose was washed with water until the washing solution became nearly neutral. Bacterial cellulose was obtained. This bacterial cellulose was used as an undissociated product (A) of bacterial cellulose obtained by the aeration stirring culture method.

For use in the comparative example, water was added to the above undisintegrated bacterial cellulose (A) to a concentration of 0.5%.
Then, this suspension was disintegrated with a household mixer for 2 minutes to obtain a disintegrated product (B) of bacterial cellulose obtained by aeration and agitation culture.

Preparation of Bacterial Cellulose-Containing Paper According to JIS-P-8209, a non-disintegrated product of bacterial cellulose (A) obtained by aeration and stirring culture method or a disintegrated product of bacterial cellulose (B) obtained by aeration and stirring culture method. 100 parts of light calcium carbonate and 1 part of positive starch were added to 100 parts of pulp mixed with the disintegrated LBKP at the ratio shown in Table 1, and a paper having a basis weight of 100 g / m ² was formed using a standard handmade sheet machine. did.

Incidentally, in Comparative Example 2, the paper web had high water retention and was sometimes broken when picked up from a wire.

Break length The bacterial cellulose-containing paper prepared by the above method was
It measured based on IS-P-8113.

Freeness test Bacterial cellulose prepared by the above method and JIS-
LBKP disintegrated in accordance with P-8209 was mixed at the ratio shown in Table 1, and in accordance with JIS-P-8121,
The Canadian standard freeness (CSF) was measured and used as an index of drainage during papermaking.

Filler Retention Test Bacterial cellulose prepared by the above method and JIS-
100 parts of light calcium carbonate and 1 part of positive starch were added to 100 parts of pulp in which LBKP disintegrated in accordance with P-8209 was mixed at a ratio shown in Table 1 in terms of solid weight, and this stock was mixed. In accordance with TAPPI standard method T261, the filler yield was determined from the amount passed through the screen.
The filler was quantified at 400 ° C. for 8 hours in accordance with TAPPI standard method T269.

Table 1 shows the measurement results.

[0026]

[Table 1]

[0027]

According to the present invention, the drainage is improved in the papermaking process and the papermaking property is excellent, so that a paper with an increased amount of bacterial cellulose can be obtained.

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Claims (2)

(57) [Claims] 1. A bacterial cellulose-containing paper containing an undisintegrated product of bacterial cellulose obtained by aeration and agitation culture. 2. A method for producing bacterial cellulose-containing paper, comprising adding bacterial cellulose obtained by aeration and agitation culture to a stock suspension without performing defibration treatment and paper-making.