JPS61194298A - Papermaking filler and neutral papermaking method using the same - 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 The present invention relates to a paper-making filler and a paper-making neutral paper-making method using the same, and more particularly to a filler composition and paper-making method that is inexpensive and exhibits extremely good plastic wire abrasion.

There are two papermaking methods, acidic and neutral, depending on the type of sizing agent used.

These two papermaking methods have advantages and disadvantages in terms of paper quality, which is distinguished by the type of sizing agent, fixing agent, and filler used, but at present most of them are acidic papermaking methods due to total cost and technical issues. Neutral papermaking is only carried out in some areas.

The acidic papermaking method uses rosin as a sizing agent and aluminum sulfate (commonly known as alum or band) as a fixing agent. These rosin and aluminum sulfate are inexpensive, and aluminum sulfate plays a very important role in the papermaking process in a wide range of ways, including not only fixing the rosin size, but also preventing slime generation and pitch adhesion within the papermaking system. This papermaking method is economically and technically advantageous.

In addition, filler is used in this acidic papermaking. Kaolin, talc, clay, titanium dioxide, etc. are used as fillers, and aluminum sulfate also contributes to improving the yield of these fillers. However, these fillers have economic disadvantages; for example, high-quality talc is difficult to obtain domestically, and titanium dioxide has high costs due to its manufacturing process. Furthermore, paper made by acid papermaking has Because it is acidified,
・As humidity increases and the amount of water absorbed by paper increases, hydrogen ions increase, and carbohydrates are subject to oxidation and hydrolysis, and decomposition and denaturation are likely to occur due to the action of other ionic species, resulting in faster paper deterioration. It is considered undesirable to use it for books such as encyclopedias, official document paper, etc. that require storage for many years.

In addition, in the case of acidic paper making, since the paper is usually made at a pH of 4 to 1) H5, corrosion of the paper machine and other metal parts is significant.

On the other hand, for neutral papermaking, alkyl ketene dimer-based sizing agents,
This papermaking method uses neutral sizing agents such as alkyl succinic acid group sizing agents, cationic fixing agents, and emulsifiers, and adjusts the white water system, which is the raw material in the papermaking process, to a pH of 7 or higher, and is also called "alkaline papermaking." .

By the way, calcium carbonate has traditionally been considered to have the same effect as the above-mentioned fillers in terms of improving the whiteness, opacity, smoothness, ink receptivity, writing characteristics, coating permeability, etc. of paper. This is available in large quantities at low cost in Japan, but unfortunately it cannot be used in acidic papermaking because it causes a chemical reaction with aluminum sulfate.However, in neutral papermaking, calcium carbonate can be used. . In fact, India paper, rice paper, back carbon base paper, etc. are made using calcium carbonate as a filler. This neutral paper not only improves paper quality by improving paper whiteness, improving opacity, and preventing deterioration of paper quality, but also allows the same paper quality to be obtained even when the filler is increased by 33 to 5% compared to acid paper. , we can also expect cost benefits from improving paper astronomy. Furthermore, reduction of beating power, improvement of white water reuse rate due to reduction of precipitated salts, reduction of fresh water heating steam amount due to improved white water reuse rate, and precipitated salts! Due to this reduction, we can expect a reduction in energy consumption, such as a reduction in scum adhering to wet parts, and operational benefits. Furthermore, recently, in the field of paper coating, coating colors are becoming more concentrated with the aim of improving the physical properties of coated paper and reducing energy costs, and heavy calcium carbonate with fine particle diameters is being used as a coating material. Kaolin is now being used in combination with kaolin in larger quantities than before, and the waste paper (waste from paper making, finishing operations, etc.) of coated paper coated with large amounts of heavy calcium carbonate is used to make acid paper. When reprocessing with a rosin-aluminum sulfate system, calcium carbonate causes a chemical reaction with the acid in aluminum sulfate, and carbon dioxide gas is generated and released, causing foaming. Calcium sulfate, etc. that are generated may settle and solidify inside tanks and pipes, causing unexpected problems in the liquid transfer process and other operations.

For the reasons mentioned above, it is desired to switch from acidic papermaking to neutral papermaking. However, despite current development research and cost reduction research being carried out on the medium weight sizing agent used in neutral papermaking, it is extremely expensive compared to the rosin-aluminum sulfate system. and
It is the only cost-increasing material in neutral papermaking, which aims to reduce costs, and it will be difficult to transition to neutral papermaking unless the total cost is reduced by using the cheapest filler possible. be. However, when cheap calcium carbonate is used as a filler, the problem of wire wear in the paper machine arises as described below.

In recent years, as paper machines have become larger and faster, wire life has become a particular concern in terms of productivity and workability. Practical use begins,
Nowadays, most large machines are made of plastic wire, and even small to medium-sized machines are now using plastic wire. The reason why plastic wire has become so popular in place of the conventionally used bronze wire is that plastic wire is less prone to wire fatigue and corrosion than bronze wire, is easier to maintain, and is also suitable for acid paper making. The wire abrasion resistance of talc and kaolin, which have been mainly used as fillers, is significantly lower when using plastic wire than when using bronze wire, and the lifespan of plastic wire is about 5% lower than that of bronze wire.
It is said that you can expect up to 10 times more. However, it is a different story when the filler changes from talc, kaolin, etc. to calcium carbonate, and when neutral paper is made using calcium carbonate as a filler in a paper machine that uses plastic wire, the behavior of calcium carbonate against wear of the plastic wire is different from that of talc. When kaolin is used, the abrasion resistance of the plastic wire is higher than that of bronze, so the abrasion of the plastic wire becomes significantly worse, which has a serious negative impact on papermaking efficiency. Wire that is extremely worn must be replaced with new wire, and the paper machine will stop operating during this time.
Its productivity will drop significantly. Generally, the wear of plastic wires due to fillers is greatly influenced by the type of filler used. Further, it is said that it depends on the size and shape of the filler particles, and the wire wear tends to increase as the filler particles become larger and as the particle surface has more knife-like protrusions.

By the way, the calcium carbonate used as a filler for papermaking includes precipitated calcium carbonate, which is chemically produced by introducing carbon dioxide gas into milk of lime, and heavy calcium carbonate, which is produced by mechanically crushing and classifying limestone. There is. In addition, the raw limestone that is the raw material for heavy calcium carbonate is also thick (roughly divided into two types, one of which is chalk, which is produced in large quantities in Europe, and this is caused by thermal metamorphosis due to magmatic activity in the earth). Because it is not subjected to heat, it is very easy to crush, the size of the particles obtained is relatively uniform, and there are almost no knife-like protrusions on the particle surface. Neutral paper making using plastic wire is popular in Europe. This is because chokes are available that have less wear on such plastic wires.

On the other hand, the other type of limestone is commonly known as Marble, which is a hard limestone that has undergone thermal metamorphosis due to magmatic activity, and almost all of the limestone produced in Japan, which is the raw material for heavy calcium carbonate, belongs to this type.

The particles of heavy calcium carbonate produced using this Ma'rble-based raw stone have an irregular shape, and there are many knifests on the surface of the particles, which causes a large amount of abrasion to the plastic wire. It cannot be used as a filler for the neutral papermaking paper used.

Because precipitated calcium carbonate is chemically produced, the particle size is uniform, and there are fewer knifings on the particle surface. Also, the width of the particle size distribution is relatively narrow, so compared to heavy calcium carbonate, there is less wear on plastic wires, making it easier to rice. It is widely used as a filler in paper and India paper, but on the other hand, it has to be expensive due to the manufacturing process, and the yield is low due to the small particle size, and furthermore, it cannot impart sufficient paper strength to paper. It has the disadvantage of
In particular, it is unsuitable as a filler for neutral papermaking, which requires the use of inexpensive fillers, and is recommended as a substitute for expensive titanium oxide.
Alternatively, its use is limited to filler for high value-added paper such as information recording paper.

On the other hand, heavy calcium carbonate is cheaper because it is easier to produce than precipitated calcium carbonate, but since it uses domestically produced marble stones as mentioned above, the particles produced are free. It has a regular shape, and there are many knives on the surface of the particles, and when used as a neutral papermaking filler, the plastic wire in the paper machine will wear out significantly. It is also possible to use small, heavy calcium carbonate as a neutral papermaking filler, but the industrial production of such fine, heavy calcium carbonate is small;
In addition, it is not a good method because it is as expensive as talc or more, and the yield rate in the paper becomes worse as the particles become smaller, and the paper strength also decreases. .

For the reasons mentioned above, there is no heavy calcium carbonate in Japan, which is similar to chalk-based calcium carbonate, which shows the same good plastic wire abrasion as precipitated calcium carbonate, so it is difficult to use neutral paper and plastic wire. Although both have been confirmed to have their own advantages, neutral paper making using plastic wire has not yet been carried out in earnest, and it is inexpensive and has the same or lower wear on plastic wire than chalk. Furthermore, there is a long-awaited development of a method for mass-producing heavy calcium carbonate that has a good yield and does not reduce whiteness or paper strength, and is being researched and considered from various angles.

For example, JP-A No. 56-144296 discloses that heavy calcium carbonate is subjected to a sand mill treatment to grind away the knife edges on the particle surface and make the particle shape rounder, thereby obtaining a papermaking filler with good physical properties. It is stated that. However, in order to obtain such heavy calcium carbonate, it is necessary to sand mill an aqueous dispersion of 30 to 85% heavy calcium carbonate once or multiple times, which is disadvantageous in terms of energy cost. Dispersants used to increase processing efficiency can significantly impair filler retention in the papermaking process.

In view of the above circumstances, the present inventors have conducted extensive research and have now provided a filler for paper manufacturing and a method for making neutral paper, which is less expensive and which surprisingly reduces plastic wire abrasion.

That is, the first aspect of the present invention is to add 0.0% of a granular composition that satisfies the following (a) to (t) to 100 parts by weight of heavy calcium carbonate.
A papermaking filler containing 1 part by weight or more; (a): Zeta potential (suspension concentration in pure water l) (b): A 10% by weight aqueous suspension of the granular composition is subjected to an ultrasonic dispersion machine. After dispersion treatment for 10 minutes, the particle diameter d of the composition measured using a standard sieve of JfS Z8801 was 22 μm.
<d≦150 μm, and (t): The specific surface area S (cd/g) of the granular composition by the BET method is expressed by the following formula (1
); S > 100.000/D -12-(1) D: Average particle diameter of the composition (μm) p: Specific gravity of the composition (However, D in the above formula (1) and ρ are measured by the following method; D: A 10% by weight aqueous suspension of the composition is dispersed for 10 minutes using an ultrasonic disperser, passed through a 125 μm (119 mesh) sieve, and the passed portion is further 100 μm (149
Pass through a mesh) sieve, and then proceed in the same manner to
μff1 (20G mesh) sieve, 45μm (330
Pass through the sieves and separate the unpassed portion on each sieve and the 45 μm sieve passed portion into 5rtf tin, measure the weight of each, and weigh % of total weight for each class. The median particle diameter of each class is set as shown in Table 1 below, and it is determined by the following formula (2): D-Σwi/Σ (wi/di) (
2) ρ: Measured by the specific gravity measuring method described in JIS K, 5101r Pigment Dispersion Method), and the second aspect of the present invention is a neutral papermaking process characterized by using the above-mentioned filler. The content is the method.

In the present invention, when dolomitic limestone or the like containing magnesium carbonate is used, calculations are made assuming that calcium carbonate and magnesium carbonate have the same effect.

In the present invention, the granular composition used by adding it to heavy calcium carbonate is a composition such as a natural product or a synthetic product (hereinafter referred to as this composition) that satisfies both conditions (a) to (ii) as described above. The composition may be arbitrarily selected from the following (abbreviated as composition A), and there are no other particular limitations.

There are still many points that are unclear as to why the wear of the ladle plastic wire is significantly improved by including Composition A in heavy calcium carbonate compared to papermaking using heavy calcium carbonate alone. This is presumably due to the following properties of composition A. That is, (2) Composition A has a negative zeta potential in water.
The granular composition must have a particle diameter of more than 2 μm and no more than 150 μm, and (1) Specific surface area S (cd/g) of composition A determined by the BET method.
is S > 100.000 /D・ρ Average particle size of D-component acid ρ: The composition must belong to the range shown in the specific gravity of the composition, and the particle size must be the same as that of the composition. A single crystal of quartz sand with (1
Since the specific surface area of a composition as shown in Figure 1, which is a schematic diagram of a single crystal of limestone (particles consisting only of particles of Composition A is composed of a large number of fine particles aggregated as shown in the schematic diagrams 2, 3 and 4, the surface of composition A is porous, or composition A is It is estimated that it has a layered structure. This is also clear from the results of microscopic photographs of Composition A used in Example 1.2.3, which will be described later. In addition, schematic diagrams 2 and 3,
It is easily understood that composition A having a shape as shown in FIG. 4 has a higher tendency to partially disintegrate due to external stress than a single crystal material as shown in FIG. 1. That is, when making paper using heavy calcium carbonate alone, as shown in the schematic diagram in Figure 5, heavy calcium carbonate (1) is generally positively charged in water, and generally negatively charged plastic wire (2) is ) and due to the stress generated between the plastic wire (2) and the ceramic part (3) of the paper machine, the heavy calcium carbonate (1)
damages the wire (2), so the wear rate of the plastic wire (2) is significantly reduced. On the contrary,
Composition #Af! In the present invention, which is mixed with ground calcium carbonate, composition A (4), which has a considerably larger particle size than ground calcium carbonate, has a negative potential in water and a positive potential, as shown in the schematic diagram in Figure 6. The heavy calcium carbonate (1) is adsorbed to the electrically charged ceramic part (3) of the paper machine and acts as a holding material for the plastic wire (2), so the heavy calcium carbonate (1) is absorbed between the plastic wire (2) and the ceramic (3). The contact between the heavy calcium carbonate (1) and the wire (2) is reduced, and as a result, the plastic wire (
2) Wear is reduced. Furthermore, due to the stress generated between the plastic wire (2) and the ceramic (3), the composition A (4), which is a wire holding material, is gradually broken and dispersed due to its shape characteristics, and the stress is dispersed. It is thought that the synergistic effect of these two reductions, which often directly damage the wire (2), significantly reduces the wear of the plastic wire.

However, even if the zeta potential is negative, as shown in the schematic diagram FIG.
When using a composition as shown in Fig. 1 of the schematic diagram that does not satisfy ρ, the composition shown in Fig. 1 fulfills the function of the holding material for the plastic wire (2) described above, and for the same reason as shown in Fig. 6 of the schematic diagram. Although the effect of reducing plastic wire wear is partially achieved, the wire holding material itself is a wire (2).
Because the stress generated between the wire and the ceramic part (3) does not easily break and disperse, the holding material itself directly damages the wire surface due to the repulsive force of the stress, and the wire wear reduction effect is significantly reduced. become.

FIG. 8 shows the relationship between the wear measurement time using the Nippon Filcon filler wear tester and the amount of plastic wire wear.

In addition, in the present invention, when a composition having a zeta potential of a stop value is used as a substitute for composition A, the structure shown in schematic diagram 6
In the figure, the composition that is the wire holding material is adsorbed to the plastic wire side, which increases the frequency of contact between the holding material and the plastic wire, which is undesirable as it may damage the wire.

Furthermore, if a composition having a particle size of 22 μm or less is used as a substitute for composition A, the particle size will be close to the coarse particles in heavy calcium carbonate, and the function as a wire holding material will not be fully exerted. 150 μm, it is not effective in reducing plastic wire wear.
When a composition having a larger particle size is used, the smoothness of the surface of the paper is impaired, which may cause trouble in the printing process, etc., which is not preferable.

In the present invention, the amount of composition A added is 0.1 part by weight or more, preferably 1 part by weight, per 100 parts by weight of ground calcium carbonate.
-30 parts by weight, and if it is less than 0.1 part by weight, the object of the present invention cannot be fully achieved.The upper limit is not particularly limited, but from the viewpoint of smoothness, paper strength, etc., about 50 parts by weight is preferable.

As described above, the present invention uses a composition obtained by mixing heavy calcium carbonate and composition A having specific physical properties as a papermaking filler, thereby making it possible to use heavy calcium carbonate alone as a papermaking filler. Compared to using it as
It becomes possible to amazingly reduce plastic wire wear.

In this way, it is possible to use heavy calcium carbonate, which has a one step smaller specific surface area (larger average particle size) than the heavy calcium carbonate that has been considered for use in the past, or in other words, it is cheaper in terms of price. Therefore, it is possible to provide an ideal papermaking filler composition and papermaking method that do not cause a decrease in paper strength or yield.

EXAMPLES Hereinafter, the features and characteristics of the present invention will be specifically explained by showing examples of the present invention together with comparative examples, but it goes without saying that the present invention is not limited to these in any way.

Furthermore, the abrasion resistance of the plastic wire is 0.85Kg.
A plastic paper-making wire (manufactured by Nippon Filcon, O3-H60) with a weight attached thereto was brought into contact with a ceramic roll, and while the roll was rotating at a speed of 283 m/sin, a sample dispersion with a filler concentration of 2 wt% was heated at 14 m/sin.
The amount of abrasion of the papermaking plastic wire was determined by measuring the weight loss of the wire after a certain period of time.

The zeta potential was determined by suspending 2 g of a dry powder sample in ion-exchanged water to prepare a slurry with a suspension concentration of 11,000 pp.
Measurement was performed using AsERZEE Plods 501J. Specific gravity was measured according to JIS K 5101-1978. In addition, a JIS Z 8801-1982 mesh sieve was used to measure the particle size and average particle size of Composition A. Further, composition A used in the present invention was dispersed in water using a tabletop ultrasonic dispersion machine vs-so at a resonance frequency of 35 KHz ±2 KHz.

Example 1 Commercially available bentonite (trade name "Akagi" manufactured by Toyokoro Yoko) powder was suspended in water and stirred at 1100 rpm for 10 minutes to obtain 20 wt.
% of bentonite suspension was prepared, it was allowed to stand for 24 hours to precipitate the coarse particles, and 24 hours after the start of precipitation, the supernatant liquid was removed, and the resulting precipitate was diluted with water to obtain a suspension of 1Qwt% of the precipitate. A suspension was prepared.

After dispersing this sediment suspension for 10 minutes using an ultrasonic dispersion machine, particles coarser than 150 μm were removed using a 100 mesh (150 μm) sieve, and particles coarser than 150 μm were separated using a 580 mesh (22 μm) sieve.
m) Using a sieve, rope particles of 22 μm or less were removed to obtain a composition suspension with a particle diameter d of 22 μm<d≦150 μm.

This composition A was mixed with heavy calcium carbonate (trade name "Super").
3SJ Maruo Calcium Co., Ltd., specific surface area 11,500cj/g by constant pressure aeration method) 4 parts by weight of solid content was added to 100 parts by weight of the papermaking filler composition.
Plastic wire wear was measured using this. The measured values are shown in Table 3.

In addition, the average particle diameter of the composition suspension added to heavy calcium carbonate and used in this example was measured using 119 mesh, 149 mesh, 200 mesh, and 330 mesh sieves, which was 53 μm, JIS K.
The specific gravity ρ measured by the method of No. 5101 was 2.43, and the zeta potential of the powder obtained by drying the suspension of the composition was -20°5 mV. The specific surface area S determined by the device was 6300 cd/g. From this result, S > 100.000/D,
It was confirmed that ρ. Incidentally, electron micrographs of composition A added to heavy calcium carbonate are shown in FIGS. 9 to 14. That is, composition A is shown in FIGS.
It is mainly composed of the three types of particle structures shown in Figures 1 and 13, and Figures 10, 12, and 14 are enlarged micrographs of Figures 9, 11, and 13, respectively. be.

Example 2 Ca (OH)2 aqueous suspension concentration 19%, liquid temperature 30
Carbon dioxide containing gas with a C02 concentration of 25% is added to milk of lime at ℃.
．． A carbonation reaction was carried out by conducting the solution at a flow rate of 3 j / 1 g of Ca (OH) 2 , and at pH 6.8, the conduction of the carbon dioxide-containing gas was stopped to obtain an aqueous suspension of calcium carbonate.

Add the same volume of the milk of lime to this aqueous suspension of calcium carbonate, perform the carbonation reaction again in the same manner, and add the same volume of milk of lime to the aqueous suspension of calcium carbonate obtained by this operation. , carbonation operation was performed a total of 5 times.

After heating the thus obtained calcium carbonate aqueous suspension system to 85°C, a 10% dilution of No. 3 water glass was dropped into the system, and the pH of the system was further adjusted to 8. A carbon dioxide-containing gas is passed through the system to precipitate fine amorphous silica on the calcium carbonate surface, and the calcium carbonate in the system becomes 100%!
When 5i02 reached 17 parts by weight, the No. 3 water glass dilution wave and the conduction of the carbon dioxide-containing gas were stopped.

The silica surface-treated calcium carbonate aqueous suspension thus obtained was dehydrated and dried using a filter press to obtain a white powder. An electron micrograph of this white powder is shown in FIG.

Next, the white powder of silica surface-treated calcium carbonate was suspended in water to prepare a 1 Qwt% aqueous suspension, and after dispersion treatment using an ultrasonic dispersion machine, it was passed through a 100 mesh (150 μm) sieve and a 580 mesh (22 μm) sieve. ) Classification was performed using a sieve to obtain a composition suspension having a particle size d of 22 μm<d≦150 μm.

This composition A was mixed with heavy calcium carbonate "Super-35J1".
A paper-like filler composition was prepared by adding 10 parts by weight as a solid content to 00 parts by weight, and using this, plastic wire abrasion was measured. The measured values are shown in Table 3.

Further, the properties of the composition used by adding it to ground calcium carbonate in this example were measured in the same manner as in Example 1. As a result, the average particle size is 308 m1, and the specific gravity ρ is 2.6.
1. BET method specific surface area S is Ueyama-no 85000c+J/g, zetahy potential is -22.3mV
Met.

Example 3 A chalk mineral specimen sold by Nippon Geikagakusha was crushed and powdered using a crusher, and a 19 wt % aqueous suspension of the powder was prepared, and the same method as in Example 1 was carried out. and the particle diameter d is 2
A composition suspension of 2 μmad≦150 μm was obtained. This electron micrograph is shown in FIG. 16.

This &u product A was added to heavy calcium carbonate ``Super 3SJ''.
After preparing a filler composition for paper making by adding 30 parts by weight as a solid content to 100 parts by weight, plastic wire abrasion was measured. The measured values are shown in Table 3.

Further, the properties of the composition used by adding it to ground calcium carbonate in this example were measured in the same manner as in Example 1. As a result, the average particle diameter was 45 μm, and the specific gravity ρ was 2.5.
8. The BET method specific surface area S was 4200 d/g, and the zeta potential was -8 mV.

Example 4 Talc (trade name D-35, manufactured by Fuji Talc) was suspended in water to prepare a 19 wt% aqueous suspension, and after dispersion treatment using an ultrasonic dispersion machine, the suspension was treated in the same manner as in Example 1. Particle diameter d is 22μ
A composition suspension with m<d≦150 μm was obtained. An electron micrograph of this is shown in FIG. 17, and an enlarged photograph of the same is shown in FIG.

This composition A was mixed with heavy calcium carbonate "Super-3SJ1".
After preparing a filler composition for paper making by adding 4 parts by weight as a solid content to 00 parts by weight, plastic wire abrasion was measured. The measured values are shown in Table 3.

Further, the properties of the composition used by adding it to ground calcium carbonate in this example were measured in the same manner as in Example 1. As a result, the average particle diameter was 68 μm, and the specific gravity ρ was 2.7.
2. BET method specific surface area S is 1400cj/g, zeta
The potential was -15 mV.

Reference Examples 1 to 3 Heavy calcium carbonate “Super 3S” and “
Super #1500J, “Super #2000J (
Both are made by Maruo Calcium, and the specific surface area measured by constant pressure aeration method is 11,500aJ/g, 14,500aJ/g, and 1
930 M/g) was used alone to measure plastic wire wear.

The results are shown in Table 3.

Comparative Example 1 Heavy calcium carbonate with coarse particle size (trade name "R heavy carbon",
Manufactured by Maruo Calcium, specific surface area 1 measured by constant pressure ventilation method
900 cd/g) was suspended in water, 10 wt% water! F
iI4j liquid was prepared, and after dispersion treatment using an ultrasonic dispersion machine, the particle size d was 22μmad≦15 in the same manner as in Example 1.
A composition suspension of 0 μm was obtained.

This electron micrograph is shown in FIG. 19.

This composition was added to heavy calcium carbonate "Super-3SJ10".
After preparing a filler composition for paper making by adding 1 (1 part) as a solid content to 0 part by weight, the wear of the plastic wire was measured. The measured values are shown in Table 3.

Further, in this comparative example, the properties of the composition used by adding it to ground calcium carbonate were measured in the same manner as in Example 1. As a result, the average particle diameter was 82 μm, and the specific gravity ρ was 2.6.
3. The BET method specific surface area S was 450 cffl/g, and the Seeku potential was +41 mV.

Comparative Example 2 A 1Qwt% water suspension was prepared by suspending quartz sand powder (trade name: rKI Clay, manufactured by Yamamori Tsuchimoto Mining Co., Ltd.) in water, and after dispersion treatment using an ultrasonic disperser, Example 1 was prepared. A composition suspension having a particle size d of 22 μm<ds150 μm was obtained in the same manner as above. This electron micrograph is shown in FIG.

This composition was added to heavy calcium carbonate "Super-3SJ10".
After adding 5 parts by weight as solid content to 0 parts by weight to prepare a filler composition for paper manufacturing, the wear of the plastic wire was measured. The measured values are shown in Table 3.

Further, in this comparative example, the properties of the composition used by adding it to ground calcium carbonate were measured in the same manner as in Example 1. As a result, the average particle diameter was 35pm, and the specific gravity ρ was 2o.
55, BE'r method specific surface area S was 590 cd/g, and zeta potential was -28 mV.

Comparative Example 3 A 10 wt % aqueous suspension of talc rD-35J prepared in Example 4 was dispersed using an ultrasonic dispersion machine and then classified using a 580 mesh (22 μm) sieve, and the particle size d was d.
A suspension of the composition having a diameter of 22 μm was obtained. This electron micrograph is shown in FIG. 21.

This composition was prepared using heavy calcium carbonate [Super-3SJ10].
After adding 4 parts by weight as a solid content to 0i parts to prepare a filler composition for paper making, plastic wire abrasion was measured. 'a1 constant values are shown in Table 3.

The properties of the composition used by adding it to heavy calcium carbonate in this comparative example are as follows: average particle size D<22 μm, specific gravity ρ 2.48, and BET method specific surface area S 38000 d/g.
The zeta potential was -34 mV.

Comparative Example 4 In Example 1, the same composition used by adding to heavy calcium carbonate was added to heavy calcium carbonate "Super 3".
SJ100f! After adding 0.01 part by weight as a solid content per part by weight to prepare a paper-making filler composition, the abrasion of the plastic wire was measured.

The measured values are shown in Table 3.

*1 Specific surface area (ca!/g) measured by constant pressure ventilation method *2 Plastic wire wear amount starts to break when weft exceeds 200 mg, so values above 200 mg are not listed *3 Wire cutting time Items that do not break even after 180 minutes from the start of measurement will not be measured.

[Brief explanation of the drawing]

Figures 1 to 4 are all schematic diagrams of particle structures;
Figures 7 to 7 are schematic diagrams showing the mechanism of plastic wire wear, Figure 8 is a graph showing the relationship between measurement time and amount of plastic wire wear, and Figures 9 to 21 are filler compositions. 10, 12, 14, and 18 are micrographs showing the particle structure of objects.
The figures are enlarged photographs of FIG. 9, FIG. 11, FIG. 13, and FIG. 17, respectively. 1... Heavy calcium carbonate 3... Ceramic portion 4... Filler composition A

Claims (1)

[Scope of Claims] 1. A filler for paper manufacturing made by adding 0.1 part by weight or more of a granular composition satisfying the following (a) to (c) to 100 parts by weight of heavy calcium carbonate; (a): Zeta potential (suspension concentration in pure water 1000
ppm, measurement temperature 20°C) has a negative value, (a): A 10% by weight aqueous suspension of the granular composition is dispersed for 10 minutes using an ultrasonic disperser, and then a JIS Z 8801 standard sieve is used. The particle diameter d of the composition measured by
m<d≦150 μm, (c): specific surface area S(c
m^2/g) is in the range shown by the following formula (1); S>100,000/D・ρ-(1) D: Average particle diameter of the composition (μm) ρ: The average particle diameter of the composition (μm) Specific gravity (however, D and ρ in the above formula (1) are measured by the following method; D: 125 μm (119 pass through a sieve of 100 μm (149 mm)
mesh) through a sieve, and then 75% in the same way.
The composition was passed through a μm (200 mesh) sieve and a 45 μm (330 mesh) sieve, and the composition was classified into five classes, the portion that did not pass through each sieve and the portion that passed through the 45 μm sieve.The composition was dried and the weight of each was measured. Determine the weight percent of the total weight for each class, and calculate the median particle diameter for each class using the following method.
Set as shown in the table, and determined by the following formula (2); Table 1 ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ ρ: Based on the specific gravity measurement method described in JIS K 5101 "Pigment dispersion method" 2. A papermaking filler is used, which is obtained by adding 0.1 part by weight or more of a granular composition satisfying the following (a) to (c) to 100 parts by weight of heavy calcium carbonate. Neutral papermaking method; (a): Zeta potential (suspension concentration in pure water 1000
ppm, measurement temperature 20°C) has a negative value, (a): A 10% by weight aqueous suspension of the granular composition is dispersed for 10 minutes using an ultrasonic disperser, and then a JIS Z 8801 standard sieve is used. The particle diameter d of the composition measured by
m<d≦150 μm, (c): specific surface area S(c
m^2/g) is in the range shown by the following formula (1); S>100,000/D・ρ-(1) D: Average particle diameter of the composition (μm) ρ: The average particle diameter of the composition (μm) Specific gravity (however, D and ρ in the above formula (1) are measured by the following method; D: 125 μm (119 pass through a sieve of 100 μm (149 mm)
mesh) through a sieve, and then 75% in the same way.
The composition was passed through a μm (200 mesh) sieve and a 45 μm (330 mesh) sieve, and the composition was classified into five classes, the portion that did not pass through each sieve and the portion that passed through the 45 μm sieve.The composition was dried and the weight of each was measured. Determine the weight percent of the total weight for each class, and calculate the median particle diameter for each class using the following method.
Set up as shown in the table and obtain by the following formula (2); Table 1 ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ D-Σwi/Σ(wi/di)-(2) ρ: JIS K 5101 (measured by the specific gravity measurement method described in "Pigment dispersion method")