JP2874825B2 - Microbial cellulose-containing filler-containing paper and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler-filled paper containing a dispersion of cellulose produced by a microorganism and a method for producing the same. More specifically, the present invention relates to a microbial cellulose-containing filler-containing paper with improved filler yield and a method for producing the same.

[0002]

2. Description of the Related Art Generally, fillers are added to paper used for various applications in order to impart opacity or whiteness. A filler-filled paper is manufactured by adding a filler to the papermaking raw material dispersed in water and then performing papermaking.

[0003] Recently, with the increase in speed of a paper machine or the improvement of quality such as reduction in weight of paper, it has been desired to use more filler more effectively. In particular, there is a high demand for improving the filler yield.

[0004] On the other hand, microbial cellulose dispersions have been included in papermaking raw materials for the purpose of enhancing paper strength, but it is said that inclusion of microbial cellulose dispersions in papermaking raw materials also improves filler yield. . For example, JP-A-1-246495 describes that a filler yield can be improved by adding a microbial cellulose dispersion and a cationic polyelectrolyte to a stock suspension to form a paper. However, since a relatively large amount of microbial cellulose needs to be added to obtain a sufficient filler yield effect, it has been desired to improve the filler yield even when a small amount of microbial cellulose is added.

Accordingly, an object of the present invention is to solve the above problems,
That is, it is an object of the present invention to provide a microbial cellulose-containing filler-filled paper with improved filler yield and a method for producing the same.

[0006]

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 production of filler-filled paper from a raw material of a raw material to which a microbial cellulose dispersion having a specific average FL value and / or a sedimentation compressibility (the definition and the like will be described later) is added improves the yield of the filler. The present invention has been completed.

That is, the present invention relates to a cellulose dispersion obtained by physically treating cellulose produced by a microorganism, wherein the cellulose has an average F value before the dispersion treatment.
Have a greater or the same average FL value than L values, and precipitation
A filled paper containing a microbial cellulose dispersion having a degree of compression lower than 0.2 and a method for producing the same.

[0008] The average FL value in the present invention is a value measured by the method described below, and seems to reflect the size of a clump of microbial cellulose. However, other methods such as an electric resistance method [a measuring method using a Coulter counter (trade name)], a sedimentation method, a density gradient centrifugation method,
It can be measured by light scattering method, ultrasonic scattering method, observation under an optical microscope or an electron microscope, image processing method, sieving method, surface area measuring method, light path shielding method and the like.

[0009] The microbial cellulose-water suspension is converted to Kajaa.
ni fiber length distribution measuring device FS-200 (Kajaani
Oy Electronics Co., Ltd.), and each average FL value is determined as an average value of measured values in a range of 0 to 1.75 mm.

The microbial cellulose before the dispersion treatment exists in a state in which the microfibers are entangled (fiber aggregate), and when this is dispersed, the apparent average FL value changes. Although each average FL value of the microbial cellulose dispersion according to the conventional method is smaller than each average FL value of the microbial cellulose before the dispersion treatment, each average FL value of the microbial cellulose dispersion of the present invention is different from each microbial cellulose before the dispersion treatment. It is characterized by having each average FL value greater than or equal to the average FL value. That is, the microbial cellulose dispersion of the present invention is obtained by a dispersion operation in which the effect of loosening the entanglement of the fibers is greater than the effect of breaking or cutting the fibers or fiber aggregates of the microbial cellulose by the dispersion operation.

[0011] 1.5 to the microbial cellulose before dispersion
Use of a microbial cellulose dispersion having a 1.7-fold number average FL value, a 1.6-2.2-fold length weighted average FL value, and a 1.5-1.9-fold weight weighted average FL value. preferable. When each average FL value is larger than the above-mentioned value, there is a drawback in that the formation of a paper sheet deteriorates and the strength of the sheet decreases.

In the present invention, the particularly preferable average FL value of the microbial cellulose dispersion is 0.28 to less than 0.28.
0.32 mm, and the length-weighted average FL value is 0.55
0.74mm, and the weight-weighted average FL value is 0.84 ~
1.04 mm.

[0013] The present invention also provides a method wherein the sedimentation compressibility is 0.27 to
The invention also relates to a filler-filled paper containing a microbial cellulose dispersion of 0.37 and a method for producing the same.

The degree of sedimentation compression in the present invention is measured by the following method. 0.1% (microbial cellulose dry weight / volume)
Of a microbial cellulose-water suspension of
Weigh out １５15 ml into a centrifugable test tube (inner diameter 14 mm × length 120 mm, volume 15 ml). The test tube is centrifuged at 3000 rpm (about 1700 × G) for 30 minutes to precipitate microbial cellulose. The ratio of the volume (v) occupied by the precipitated microbial cellulose after completion of the centrifugation to the volume (V) of the suspension, that is, v / V, was determined.
Let it be the degree of sedimentation compression.

The microbial cellulose in the present invention can be obtained by static culture, stirring culture, aeration culture, shaking culture or a combination thereof. For example, JP-A-59-
120159, JP-A-61-152296, JP-A-61-212295, JP-A-62-2
No. 65990, JP-A-62-175190,
JP-A-63-202394, JP-A-62-364
No. 67, Japanese Patent Application Laid-Open No. 63-74490,
-500116, JP-T-62-500630, and the like. Microbial cellulose obtained by stirring culture, aeration culture and shaking culture, particularly preferably aeration and stirring culture is preferred.

The microbial cellulose in the present invention may be cultured together with other fibrous materials such as pulp, organic synthetic fibers, inorganic synthetic fibers, inorganic fillers, whiskers and the like. Microbial cellulose may be chemically modified such as methylated or acetylated.

It is considered that the dispersion of microbial cellulose is due to the fact that a mechanical external force generates stress inside the cellulose and deforms and destroys it. The mechanical external force includes tension, bending, compression, torsion, impact, shear, and the like, and generally, compression, impact, and shear are mainly used.

In the dispersion by a mixer, the mechanical external force is mainly composed of an impact force caused by collision of the stirring blade with microbial cellulose and a shear stress generated by a displacement phenomenon caused by a difference in speed of the medium.

In the dispersion by the polytron, the mechanical external force includes a compressive force due to the microbial cellulose being sandwiched between the external teeth and the internal teeth, an impact force due to the collision of the high-speed rotating tooth with the microbial cellulose, and a stationary external tooth. And the shear stress generated in the medium existing in the gap between the internal teeth rotating at high speed.

In the dispersion by the ultrasonic crusher, the mechanical external force is mainly cavitation (cavity phenomenon) continuously generated in the medium due to the oscillation of the ultrasonic oscillating section, and the local shear stress is mainly generated.

As described above, the microbial cellulose dispersion of the present invention can be obtained by a dispersing operation in which the effect of loosening the entanglement between the fibers is greater than the effect of breaking or cutting the fibers or fiber aggregates of the microbial cellulose.

The microbial cellulose dispersion of the present invention can be produced, for example, by the following method. Microbial cellulose obtained by the culture is separated from the culture solution by a centrifugation method, a filtration method, or the like. The separated microbial cellulose is optionally washed.
Washing can be performed with water or an aqueous solution of an acid, an alkali, a neutral detergent, a surfactant, a bleach and the like. Next, water, a solvent and the like are added to adjust the dispersion concentration, and then the suspension is dispersed by applying a physical force. As a device for applying a physical force, any device can be used as long as the above-mentioned average FL value and / or the degree of compression settling of the microbial cellulose can be obtained. For example, a mixer, a homogenizer, a homomixer, a Polytron (trade name), an ultrasonic crusher and the like can be mentioned. These devices may be used in combination. The preferred device is an sonicator. By adjusting the degree of dispersion, the average FL value and / or the degree of sedimentation compression of the microbial cellulose dispersion can be within the above range. Adjustment of the degree of dispersion can be performed, for example, by changing the output of the apparatus or changing the dispersion time.

Dispersion is carried out by dissolving electrolytes such as calcium chloride and sodium chloride, pigments, inorganic compounds such as fine particles of activated carbon, sizing agents, yield improvers, fluorescent agents, and fungicides in water and solvents.
Organic compounds such as an antistatic agent and latex may be mixed in advance.

As the filler in the present invention, light calcium carbonate, heavy calcium carbonate, talc, clay, titanium dioxide, calcium sulfate, barium sulfate, aluminum hydroxide, activated clay, synthetic silicate, kaolin, calcined kaolin, plastic pigment, etc. Is mentioned.

Filler and microbial cellulose dispersion (dry matter,
The same applies hereinafter), the weight ratio is preferably 5 to 100: 1, and more preferably 10 to 50: 1. If the weight ratio of the filler to the microbial cellulose dispersion is less than 5, the filler yield effect becomes saturated, and if it exceeds 100, the improvement in the filler yield becomes small.

The filler content in the paper is preferably from 2 to 50% by weight. If the content is less than 2% by weight, problems such as deterioration of paper habit and decrease in opacity occur, and it becomes difficult to exhibit the advantages associated with the addition of the filler. If it exceeds 50% by weight, problems such as reduction in paper strength occur.

In another embodiment of the present invention, a cationic or amphoteric polymer electrolyte can be further added. The amount of the electrolyte to be added varies depending on the type of the electrolyte to be used, the properties and the amount of the microbial cellulose dispersion and the filler,
10% by weight is suitable.

Preferred cationic polymer electrolytes include, for example, cationic polyacrylamide, cationic starch, cationic guar gum and the like.

Preferred amphoteric polymer electrolytes include, for example, amphoteric polyacrylamide, amphoteric starch, and amphoteric guar gum.

[0030]

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

Examples and Comparative Examples Culture Conditions of Microbial Cellulose Cellulose-producing acetic acid bacteria were cultured using a flask culture method and a jar fermenter culture method.

Microbial cellulose flask culture method Fructose 40 g / L, monopotassium phosphate 1.0 g /
L, magnesium sulfate 0.3 g / L, ammonium sulfate 3 g / L, bacto-peptone 5 g / L, lactic acid 1.4 ml
/ L, 100 ml of a basic medium having an initial pH of 5.0 was placed in a 750 ml Roux flask and the cellulose-producing acetic acid bacteria Acetobacter sp.
1 (FERM P13466) was inoculated with 1 ml of a cryopreserved bacterial solution, 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, at 10,000 rpm, 15
Centrifuge for 1 minute, and media components and cells (+ microcellulose)
Were further 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.

Next, 7.5 ml of the seed bacterial solution was inoculated into a 300 ml baffle flask into which 67.5 ml of the above-mentioned basic medium had been filled. Using a shaking incubator, culture was performed for 4 days while rotating and shaking under the conditions of an amplitude of 2 cm, a rotation speed of 180 rpm, and a temperature of 28 ° C. After the solid matter in the flask was washed with water to remove the medium components, it was added in a 1% aqueous NaOH solution to remove
The cells were treated at 20 ° C. for 20 minutes to remove the cells, and the cellulose was washed with water until the washing solution became nearly neutral to obtain microbial cellulose. This microbial cellulose was used in subsequent experiments such as dispersion.

Microbial cellulose jar fermenter culturing method 750 ml of Ro containing 100 ml of the above basic medium
In a ux flask, a cellulose-producing acetic acid bacterium Acetobacter species BPR2001 (FERM P1346) was added.
Inoculate 1 ml of the cryopreserved bacterial solution of 6), and incubate in a constant temperature incubator.
Static culture was performed at 8 ° C for 3 days. After the stationary culture was completed, the Roux flask was shaken well, and then the contents were subjected to gauze filtration under aseptic conditions to separate the cellulose fragments from the bacterial cells. 7.5 ml of the obtained bacterial solution was inoculated into a 300 ml baffle flask into which 67.5 ml of the above-mentioned basic medium had been placed, and was rotationally shaken using a shaking incubator under the conditions of an amplitude of 2 cm, a rotation speed of 180 rpm, and a temperature of 28 ° C. Seed culture was performed for 3 days.

After completion of the culture, the contents of the flask were used as a seed bacterial solution and used in the following jar fermenter culture.

A small jar fermenter (total volume: 1000 ml) into which 540 ml of a culture medium for jar fermenter culturing described below, which has been sterilized with 60 ml of the above seed cell solution, has been sterilized.
ml) aseptically and inoculated at 30 ° C. for 20 or 30 hours at pH 5.0 with 1N NaOH or 1N H ₂ SO ₄ .
While controlling the stirring speed
At 0 rpm, the dissolved oxygen (DO) is 3.0 to 21.0%
The culture was performed with a jar fermenter while automatically controlling the number of revolutions so as to enter the inside.

For jar fermenter culture, a medium having the following composition was used.

Fructose 40 g / L, KH ₂ PO ₄ 1.0 g / L, MgSO ₄ 0.3 g / L, (NH ₄ ) ₂ SO ₄ 3 g / L, Bacto-Soyton (manufactured by Difco) 5 g / L and beans Concentrated (acid hydrolyzed concentrated solution of soybean protein) 5 g / L Initial pH 5.0 After completion of the culture, the solid matter in the jar fermenter is accumulated, washed with water to remove the medium components, and then in 1% NaOH aqueous solution. The cells were removed at 110 ° C. for 20 minutes. Further, the resulting cellulose was washed with water until the washing liquid became nearly neutral, and then used for subsequent experiments such as dispersion.

Dispersion of Microbial Cellulose Water was added to the washed microbial cellulose obtained by the above flask culture method or jar fermenter culture method to adjust the dispersion concentration to 0.1% (microbial cellulose dry weight / volume). Next, this suspension was dispersed at 25 ° C. for 3 minutes by an ultrasonic crusher. Average FL value of the obtained dispersion (A),
The degree of settling compression was measured.

For comparison, water was added to the washed microbial cellulose obtained by the flask culture method or the jar fermenter culture method to adjust the dispersion concentration to 0.1% (microbial cellulose dry weight / volume). Was dispersed at 25 ° C. for 1 minute by a conventional method (using a mixer). The average FL value and the degree of sedimentation compression of the obtained dispersion (B) were measured.

The above series of operations including the culture step was repeated 10 times. Table 1 shows the measurement results.

[0042]

[Table 1]

The measured values indicate the average of the values measured 10 times, and the values in parentheses indicate the range of the values measured 10 times.

Preparation of Microbial Cellulose-Containing Filler-Incorporated Paper Microbial cellulose dispersion (A) or (B) obtained by the above method, LB disintegrated according to JIS-P-8209
KP, light calcium carbonate and, if necessary, positive starch were added at the ratios shown in Table 2, and a paper having a basis weight of 100 g / m ² was formed using a standard handmade sheet machine.

[0045] The breaking length of the breaking length microbial cellulose content filled paper prepared above was measured according to JIS-P-8113.

Filler Yield Test Microbial cellulose dispersion (A) or (B) prepared by the above-described method, and defibrated according to JIS-P-8209.
BKP, light calcium carbonate and, if necessary, positive starch were mixed at the ratios shown in Table 2, and T
Filler yield was determined from the amount passed through the screen in accordance with APPI standard method T261. The amount of filler is determined by TAP
The incineration was performed at 400 ° C. for 8 hours in accordance with the PI standard method T269.

Table 2 shows the measurement results.

[0048]

[Table 2]

The measured value is the average of the values measured ten times.

[0050]

Industrial Applicability The present invention can provide a microbial cellulose-containing filler-filled paper with improved filler yield and a method for producing the same.

Continuation of the front page (56) References JP-A-7-119068 (JP, A) JP-A-7-118301 (JP, A) JP-A-1-246495 (JP, A) (58) Fields investigated (Int) .Cl. ⁶ , DB name) D21H 11/00-11/22

Claims (10)

(57) [Claims] 1. A microorganism comprising a cellulose dispersion obtained by physically treating cellulose produced, have a greater than or equal average FL value than the average FL value of the cellulose before the dispersion treatment, and Settling compression of 0.2
An internally-filled microbial cellulose-filled paper obtained by papermaking a papermaking raw material containing a larger microbial cellulose dispersion and a filler. 2. A papermaking raw material comprising a cellulose dispersion obtained by physically treating cellulose produced by a microorganism and having a sedimentation compressibility of 0.27 to 0.37 and a filler. A microbial cellulose-containing filler-containing paper, which is formed by papermaking. 3. A cellulose dispersion obtained by physically treating cellulose produced by a microorganism, wherein the number average FL value is 0.28 to 0.32 mm and the length weighted average FL value is 0.2. 55～0.74Mm, and Ri-weighted average FL value 0.84~1.04mm der, and precipitation
An internally-filled microbial cellulose-containing paper obtained by forming a papermaking raw material containing a microbial cellulose dispersion having a degree of decompression of greater than 0.2 and a filler. 4. The weight ratio between the filler and the microbial cellulose is 5 to 5.
The filler-filled paper containing microbial cellulose according to any one of claims 1 to 3, wherein the ratio is 100: 1. 5. The microporous cellulose-containing filler-filled paper according to claim 1, further comprising a cationic or amphoteric polymer electrolyte in the papermaking raw material. 6. microorganism A cellulose dispersion obtained by physically treating cellulose produced, they have a greater than or equal average FL value than the average FL value of the cellulose before the dispersion treatment, and Settling compression of 0.2
A process for producing a paper containing a microbial cellulose-containing filler, which comprises adding a larger microbial cellulose dispersion and a filler to a papermaking raw material to form a paper. 7. A papermaking raw material comprising a cellulose dispersion obtained by physically treating cellulose produced by a microorganism and having a sedimentation compressibility of 0.27 to 0.37 and a filler. A method for producing a microbial cellulose-containing filler-filled paper, which comprises adding and papermaking. 8. A cellulose dispersion obtained by physically treating cellulose produced by a microorganism, wherein the number average FL value is 0.28 to 0.32 mm, and the length weighted average FL value is 0.2. 55～0.74Mm, and Ri-weighted average FL value 0.84~1.04mm der, and precipitation
A method for producing a microbial cellulose-containing filler-inner paper, comprising adding a microbial cellulose dispersion and a filler having a degree of decompression of greater than 0.2 to a papermaking raw material and forming the paper. 9. The weight ratio of the filler to the microbial cellulose is 5 to 9.
The method for producing a microbial cellulose-containing filler-containing paper according to any one of claims 6 to 8, wherein the ratio is 100: 1. 10. The papermaking material according to claim 6, further comprising a cationic or amphoteric polymer electrolyte.
The method for producing a microbial cellulose-containing filler-containing paper according to any one of the above.