JPS6197499A - Production of paper filler - 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 (Field of Industrial Application) The present invention relates to a method for producing a filler for paper, particularly for newsprint, which has good oil absorption properties and control of resin components in paper, so-called pitch control. This invention relates to a method for producing a paper filler that also has the following features.

(Technical Background) In recent years, printing paper, especially newspapers, have tended to have larger print sizes for easier reading. For this reason, the number of articles that can fit on each page decreases, and the number of pages must be increased, resulting in an increase in weight. One way to deal with this is to reduce costs as much as possible, make the paper thinner, and make the city lighter. However, when paper is thinly printed, it is necessary to avoid bleeding of printing ink and the appearance of characters on the back of the paper as much as possible, and in particular, ink has a quick oil absorption property when printed on high-speed rotary presses. By the way. Bleeding can be prevented and characters can be prevented from appearing on the back of the paper.

To achieve this purpose, it has been proposed to fill paper with fillers, but this is usually done at the papermaking stage, which involves a highly acidic atmosphere and takes a considerable amount of time. It will be done.

(Prior Art) Conventionally, as fillers to be filled into paper, clay, kaolin, waxite, talc, calcium carbonate, etc. have been proposed, and some of them have been put into practical use.

(Problems to be Solved by the Invention) However, most of these fillers do not have pitch control ability, and have insufficient oil absorption ability.
Alternatively, they have the disadvantage that they cannot necessarily withstand the acidic atmosphere during paper making.

Incidentally, although talc has pitch control ability, almost no oil absorption could be expected.

(Means for Solving the Problems) The present invention eliminates the drawbacks of these conventional techniques, has sufficient oil absorption ability, is sufficiently resistant to the acidic atmosphere during paper making, and has resin components present in the pulp ( Zeolite is used as a filler that can effectively act as a so-called pitch control agent that prevents pitch from clumping up and hindering paper-making operations, disperses it uniformly, and actively acts as a binding agent for the pulp. We discovered that silica can be combined with silica, but after further consideration, we selected zeolite with a specific composition as the starting material and treated it with alkali and acid to achieve high oil absorption and good pitch control effects at the same time. It has been found that a filler can be obtained.

Thus, the present invention has the general formula M7 /nO.Al2O3.x
A raw material aluminosilicate consisting of si02 yH7O (wherein is selected from Na, K, and Ca, 2 is 1-10, and Y is 0-20) is treated with alkali and then treated with acid to produce a general Formula M+ /nO・Al2O3@x
si02 @ yH20 (however, the corresponding Na,
K, Ca, 2 is 0.5 to 7, and y is θ to 20). be.

In the present invention, the raw material for aluminum/silicic acid must be of the above general formula. If this general formula is deviated from, a filler having desirable oil absorbency and pitch control action cannot be obtained and is therefore unsuitable.

The raw aluminosilicate is first subjected to alkali treatment, but prior to that, the raw material is pulverized.

This pulverization almost determines the average particle size that becomes the filler, so if it is too large or too small, it is not preferable because it will have a negative effect on oil absorption and pinch control.
Generally, it is appropriate to crush the powder to about 1 to 5 liters. The pulverized raw material is then treated with an alkali to elute a portion of the silica contained in the raw material. The amount of alkali used at this time is suitably about 0.2 to 1 in terms of molar ratio of NazO/5i02 to silica.

If the amount of alkali used is less than the above range, the elution rate of silica will be slow and the elution will be insufficient, while if it exceeds the above range, the pitch control effect may be reduced, which is not preferable. .

During alkali treatment, if the solid content concentration is too high, non-uniform reaction or partial lateralization will occur, while if it is too low, not only will the reactivity be poor, but heat will be consumed unnecessarily. becomes. Therefore, the solid content concentration is 5 to 25% by weight,
Preferably, it is appropriate to employ 10 to 20% by weight. and 4 to 20 at a temperature of 35 to 100°C at normal pressure.
It is carried out over time. At this time, stirring can be carried out if desired. As the alkali, a Y alkali is usually used.

In such a treatment, if the raw material aluminosilicate is an amorphous raw material such as hydroxysodalite, part of the silica content in the raw material is dissolved, and the raw material is treated with K, such as zeolite. Forms a crystalline skeleton, and if the raw material aluminosilicate is a crystalline substance such as zeolite, part of the silica in the raw material is dissolved while retaining most of the crystalline skeleton. urge

The thus treated aluminum/silicate is subjected to the next acid treatment without solid-liquid separation. The acid treatment is carried out in two stages as follows. First, during acid treatment, the solid content concentration is adjusted to 15 to 20% by weight. It is better for the solid content concentration to be as high as possible; however, if it is too concentrated, the dissolved silica content may rapidly or partially gel, leading to the formation of lumps.

Then add mineral acid to adjust the pH of the liquid! Make it about 1.5 to 10.5. The liquid temperature at this time is about 70 to θO<0>C, and is maintained for about 10 minutes. This operation is carried out to gel the dissolved silica component, which results in a bulk specific gravity of 0.2 to 0, which exhibits favorable oil absorption as a paper filler.
．． You can force it to 4.

Next, a mineral acid is added to adjust the pH to 7 to 4.5, thereby sufficiently gelling the silica content.

The liquid temperature and time at this time are not very strict.

The mineral acids used in the present invention are sulfuric acid, hydrochloric acid, and nitric acid, and sulfuric acid is particularly preferred because it facilitates gelation of silica.

The solid content thus obtained, that is, a mixture of crystallized aluminosilicon I'll having a skeleton typified by zeolite and silica, is then dehydrated and washed with water to produce a product.

The proportion of the mixture of crystallized aluminosilicate and silica is 10 to 80% by weight for the former and 90 to 10% by weight for the latter.
Although it is possible to prepare up to a certain extent by this method, as a paper filler, a ratio of about 1:1 provides the best oil absorption and also provides a good pinch control effect.

Furthermore, the aluminosilicate used as a starting material in the present invention may be amorphous, crystalline, natural, or synthetic, but in particular, it is called clinoptilolite (Na2
e K2 5ca) 0* Al7Q3 m10Si
Good results can be expected when using O3.8H70.

Next, the present invention will be explained by examples.

Linoptilolite ore from Niki, Hokkaido (Na2Φ2
．． e Ca) 0 dispute A1703 e 10SiQ2
*8H7Q was ground to an average particle size of 5μ, caustic soda was added so that the molar ratio of Na2Q to 5iQ2 was Na2Q/5iO=0.48, and water was added so that the solid content concentration was 25% by weight. This was maintained at a temperature of 90° C. for 8 hours to cause some of the silica to be eluted. Next, these were prepared so that the solid content concentration was 15% by weight, sulfuric acid was added so that the pH of the liquid was 11.5, and 3 Gg of mirabilite was added to 100 g of clinobutyrite ore.

It was held for about 10 minutes. The liquid temperature at this time was 80°C. Next, sulfuric acid was added so that the pH became 4.5, and after stirring gently for about 5 minutes, the solid content produced was dehydrated using a Puchner furnace and washed with water. did.

The obtained solid content is Na2Q e Al2Q3 m 2 ~
55iQ2 *35.2% by weight of zeolite with an average particle size of 5L having the composition of 5H20, 38.3% by weight of anhydrous silica with an average particle size of 15g and a bulk specific gravity of 0.2, and the remainder is zeolite with an average particle size of 5W. A filler consisting of a regular glassy homogeneity was obtained.

Newspaper pulp 2000 with bone-dry profitability density of 2.5% by weight
g was placed in a disintegrating machine with an internal capacity of 2, and the above-mentioned filler was added thereto in an amount of 2% by weight based on the bone-dry pulp, and the mixture was stirred at 1400 r, p, m for 2 minutes. Next, the concentration is 11.56 in terms of 18 hydrate salt.
g/JL aluminum sulfate aqueous solution was added, and 1
After stirring at 400 r, p, m for 2 minutes, tap water was further added to dilute the pulp to 0.63 weight 2 with 1 degree of bone dry equivalent pulp, and a papermaking raw material was obtained. The papermaking raw material liquid was fractionated using a handmade papermaking test device compliant with JIS P8209, and papermaking was performed according to the following procedure.

After the wet paper was formed on the wire mesh, two sheets of absorbent paper were placed on top of the wet paper, and a coach roll was rolled back and forth five times on top of the wet paper. Next, the wet paper, blotting paper, and coach plate are removed from the wire mesh, and the wet paper adhering to the blotting paper is placed on top of the drying plate previously placed on the press board and the blotting paper placed on top of it. After transferring, a drying plate was placed on top.

Next, after dehydration for 5 minutes at 3.5 kg/cn+ in the first press.

In the second press, peel off the wet blotting paper from the drying plate and put another dry blotting paper on top of the wet paper to give a weight of 3.5 kg/co.
It was dehydrated for 2 minutes at t. After pressing, take out the drying plate with the wet paper on it, stack the two plates with the wet paper on the outside, sandwich them between the drying rings, tighten them, and dry them at room temperature in a blow dryer. and took out the paper.

Obtained handmade paper (diameter 16cm■circular, 200cnl
) was 0.92 g (4El cni/g) in absolute dry mass. Using this paper, the opacity after printing was measured by the following method. In addition, the opacity after printing is the reflectance (R1) of one side of the paper measured with a Hunter reflectance meter. (R2) was measured and determined by the following formula.

Opacity after printing - R7/RI Printing (reflectance of printed surface 12%)
After printing, the opacity was determined.

The opacity after printing was 87.1% when printed on the surface that was in contact with the wire mesh during paper making (hereinafter referred to as the wire surface, and the reflective surface is referred to as the felt surface). In that case, it was 87.0%.

Paper filled with fillers according to the invention showed an increase in opacity after printing of about 5% or more compared to papers similarly made without fillers.

Claims (1)

[Claims] 1. General formula M_2/nO・Al_2O_3・xSiO_
By treating raw material aluminosilicate consisting of 2.yH_2O (where H is selected from Na, K, and Ca, x is 1 to 10, and Y is 0 to 20) with alkali and then with acid, general Formula M_2/nO・Al_2O_3・xSi
O_2・yH_2O (However, M is the corresponding Na, K, C
a, x is 0.5 to 7, and y is 0 to 20). 2. The manufacturing method according to claim (1), wherein the raw material aluminosilicate is clinoptilolite ore. 3. In the alkali treatment, the molar ratio of Na_2O/SiO_2 to the silica in the raw aluminosilicate is 0.2 to 1, and the temperature is 35 to 10% at a solid content concentration of 5 to 25% by weight.
The manufacturing method according to claim (1), which is carried out at 0°C for 4 to 20 hours. 4. Acid treatment is performed at a solid content concentration of 15 to 20% by weight and a temperature of 30 to 100°C by adding mineral acid to pH 11.5 to 10.
5 and hold for 5-20 minutes, then add mineral acid to pH
7 to 4.5. The manufacturing method according to claim (1).