JPS5926594A - Paper sizing method - 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 sizing process, and more particularly to a sizing process for calcium carbonate filled paper.

In conventional paper scissors, the fiber aqueous suspension is
The resin is usually precipitated by a precipitating agent and supplemented with a lotone-based resin cysong agent.

The most widespread and commonly used precipitating agent is aluminum sulfate, which is added to an aqueous suspension of fibers in the form of an aqueous solution.

It is also known that, depending on the end use of the paper, the fiber suspension can be supplemented with suitable inert fillers to impart specific properties to the paper.

Precipitation with aluminum sulfate is performed at acidic pH, especially 4.5.
Since it occurs at pu to 6, there is no problem if the acidic environment has no effect on the filling side or if the filler does not interfere with the behavior of the precipitant. A typical example in such a situation is kaolin, which must be particularly pure. This is because impurities such as calcium carbonate react with aluminum sulfate to form calcium sulfate, thereby stopping some of the desired action of the precipitant and releasing carbon dioxide, which is present in the fiber suspension. and become trapped in the resulting paper, resulting in obvious problems and drawbacks.

These problems and drawbacks are greatest when the filler is actually calcium carbonate. In fact, if aluminum sulfate has to be used as a precipitant, a reaction between aluminum sulfate and calcium carbonate will first occur until the calcium carbonate is completely exhausted and the filler disappears. . Only by adding more aluminum sulfate at that point would it be possible to effect precipitation of the sizing agent.

In addition to the problems and disadvantages already mentioned, in moderate amounts, especially calcium sulfate formation also occurs, which is associated with further contamination problems and hence cleaning of the process effluent.

On the other hand, it is not possible to use aluminum sulfate at neutral or alkaline pH using the rosemium-based scissors used to date. This is because no precipitation occurs due to the lack of charge neutralization of the cyson agent dispersed in the tag fraction.

Finally, there is the problem of recirculating so-called coated breaks, which are filled with calcium carbonate into the paper manufacturing process, into the paper manufacturing process. do.

For these reasons, prior to the present invention, paper cysong agents in the presence of calcium carbonate as a filler, synthetic cysong agents that do not cause the above-mentioned technical problems (for example, Aquabell (Aqu) manufactured and sold by Percules, etc.
however, the use of these sizing agents has been associated with excessively high costs.

The improvement of paper scissors by avoiding the use of aluminum sulfate is also proposed in Canadian %♂1 No. 759.363, which states that for this purpose, the following general formula % (where X is a partial anion, for example chlorine, and n is 1
20.1 to 4 to 10, m is smaller than 3n, and the ratio At/X is 1.5 to 6, especially 2 to 4.
It is foreseen that the use of basic aluminum alloys with

However, the fillers used in the above specification and examples are not actually listed.

Regarding the operating pH, Specification 1 above indicates a general range of 5 to 8, preferably 5.5 to 7.0.

However, when referring to pH in the Examples, it has a maximum value of 68 (Example 3).

It is therefore clear that the problem of fillers, in particular the use of calcium carbonate, is not taken into account in this method.

Published French patent application No. 2,418,297 proposes that by improving the properties of the paper thus obtained,
The problem of reducing the content of suspended solids in the effluent resulting from paper cysong operations is explicitly addressed.

For this, as a precipitant, the formula % formula % (where M can be aluminum, is 30% to 75316).

The presence in the abovementioned salts of polyvalent anions, for example anions of mineral acids such as sulfuric acid, is particularly preferred.

As a result, this process requires
No consideration is given to the type of filler, although the possible fillers, i.e. kaolin, calcium carbonate, talc, etc., are indicated in mb le ) without establishing any distinction between them. it is obvious.

Finally, in order to complete the above technical situation, in recent years aluminum polychloride (aluminum polychloride) and aluminum polyhydroxychloride (aluminum
ium poly)r, hydroxychloride
) has been suggested and experimented with success.

Aluminum polychloride and aluminum polyhydroxychloride polymers are defined as, for example, in the case of polyhydroxychloride: is an integer varying between 5 and 15).

However, theoretically, when aluminum polyhydroxychloride is hydrolyzed, it gives rise to a slightly acidic environment, which on the one hand justifies the functioning of a substitute for aluminum sulfate, and on the other hand, such an assumption does not support carbonate It should be pointed out that in the case of calcium and similar fillers this would lead to the exclusion of their use.

The use of aluminum polyhydroxychloride as a precipitant allows, on the one hand, the precipitation of resin cysong agents pasting rosin at neutral to alkaline p II values, and, on the other hand, the precipitation of calcium carbonate or similar substances. It has now surprisingly been discovered that it is possible to perform scissors of filled paper, and
This is the subject of the invention.

Accordingly, the present invention includes adding a precipitant to an aqueous suspension of fibers containing a rosin-based resin sizing agent;
In the paper cysong process of the type in which calcium carbonate or similar substances are used as paper filler, aluminum polyhydroxychloride with the formula % () (where 0.85≦Z<6) and the formula Provided is a method for producing pulp mold using a compound made from aluminum polychloride having the formula %(), where 0≦y≦ω.

As already mentioned, the method according to the invention allows unexpected and unforeseen force results to be achieved. This is because by using a conventional sizing agent in place of a high quality sizing agent, this sizing operation falls within conventional techniques that have been used satisfactorily for a long time. Because it will be. By way of illustration and not limitation, the results achieved by the invention will now be described by way of example.

Example 1 This example 1j uses kaolin as a filler.
A white paper (wh, i
te paper) is disclosed. Paper pulp is bleached cellulose (9
0%) and waste paper pulp (Io%).

In Table 1 below, the results and conditions under which the experiments were conducted are reported. In the table, alum or aluminum sulfate is designated by A and 7"of" Co., Ltd. (Pτ
odeco Spa) Pro Deflock Sub (P
A commercially available type of aluminum polyhydroxychloride under the name RODEFLOC5AB)19 is B
It is shown by.

EXAMPLE 2 This example describes an exercise book with a weight of 65 f/ffl filled with 59% calcium carbonate and 75% Kaori.
These percentages refer to dry paper.

The paper pulp forming the fiber suspension had the following composition.

Bleached cellulose 50% semi-chemical Gurup 205)/6 wood pulp
10%.

Waste Paper Nozorg 20% The results of the Cysong test are reported in Table 2 below.

Example 3 This example describes the use of paper so useful as a support for coated paper.
y/cr! Regarding the production of r.

The nokulp that forms the fiber suspension breaks down the following composition: Bleached cellulose 33 Bleached wood nokulp t) 296' coated waste paper
d brokes) 45'l; Covered waste paper is 2o
Note that it contains, on average, ao9i calcium carbonate.

- - ∆ Insect-sized rock - - Precipitation of the resin cysong agent is carried out from the surface of the tip.
It can clearly be seen that H is determined after reaching neutrality.

Whereas paper cannot be sieved with ordinary precipitants,
is satisfactorily sized using the method of the invention.

Similar results are obtained by repeating the experiment using aluminum polychloride.

Patent applicant: Prodeco Soceta Bel Accioni

Claims (1)

[Claims] ■. A type of paper in which a precipitant is added to an aqueous suspension of fibers containing a resin cysong agent based on Rosone, and calcium carbonate or a similar substance is further used as a paper filler. In the Sai-Song method, aluminum polyhydroxychloride with the formula % (% formula %) (wherein 0.85≦Z<6) and A 1. If act, y (n) (0 in the formula
≦y≦ω) is used as a precipitant, and the precipitation is carried out at a neutral to alkaline pH. 2. The method according to claim 1, wherein the precipitation is carried out at pH 7.