JPH0357238B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for producing interleaving paper that is inserted between adjacent glasses when transporting and storing glass such as laminated glass plates. , relates to a method for producing glass interleaving paper using waste paper and groundwood pulp as papermaking raw materials.

According to this type of glass paper manufacturing method that uses waste paper as a manufacturing raw material, the higher the proportion of waste paper used as the paper manufacturing raw material, the lower the raw material cost and manufacturing cost. In order to make the paper thinner while still making it strong, the paper contains about twice as much resin as groundwood pulp. In addition, as the proportion of used paper increases, the resin content of the papermaking raw material increases.

On the other hand, as a result of conducting a test (details will be described later) to examine the correlation between the resin content of glass interleaving paper and performance, the inventor found that (a) the resin content of glass interleaving paper ( If the amount extracted in the ether extraction test (the same applies hereafter) is large,
The moisture absorbency of the interleaving paper deteriorates, and the moisture on the glass surface cannot be reliably absorbed by the interleaving paper, resulting in burnt glass, and the amount of adhesion to the glass surface due to volatilization, elution, and transfer of the resin contained therein decreases. (b) By reducing the resin content of the glass interleaving paper to 0.3% by weight or less, the above-mentioned burning and paper adhesion can be reduced to a range that does not pose a practical problem. We found out that things can be suppressed.

The conventional method for manufacturing glass interleaving paper is to defibrate, decompose, remove resin and foreign matter from the papermaking raw materials mentioned above, and then add an organic sizing agent such as rosin to make paper. In other words, the manufacturing method is the same as for ordinary paper.

Therefore, when using the conventional method, since an organic sizing agent, which is a type of resin, is added, the resin content of the interleaving paper increases due to the addition of this organic sizing agent. 0.3% by weight
In order to produce glass interleaving paper that has excellent performance in preventing glass burns and paper skin adhesion to glass,
In addition to reducing the proportion of waste paper used, the resin and fat removal process for papermaking raw materials is repeated many times, and the resin content is reduced to 0.3 by adding organic size before adding organic size.
The resin content must be reduced to a value that does not exceed the weight percentage, which increases costs and complicates manufacturing operations, and as a result, in practice,
In view of cost and manufacturing, the resin content of glass interleaving paper has to be approximately 0.35 to 1.0% by weight.

In view of the above situation, the present inventor conducted a test and found that if paper is made without adding an organic sizing agent, even if the proportion of used paper is 100% by weight, the resin and fat removal operation is necessary. Even if you do not repeat it many times, you can reduce the resin content of glass paper by 0.3% by weight by performing the resin removal operation twice.
We have found that the following can be done, and the purpose of the present invention is to reduce the resin content based on this knowledge.
The object of the present invention is to provide an inexpensive and easy method for producing glass interleaving paper containing 0.3% by weight or less and excellent performance in preventing glass burning and paper skin adhesion to glass.

The feature of the glass interleaving paper manufacturing method according to the present invention, which was taken to achieve the above object, is that after the papermaking raw material is defibrated, resin-removed, and foreign matter removed, paper is made without adding any organic sizing agent. It is in the point of doing.

Therefore, according to the method of the present invention, the proportion of recycled paper used can be increased, and the degreasing operation for papermaking raw materials can be limited to two or three times at most, thereby reducing costs and simplifying manufacturing operations. , the resin content is
With a content of 0.3% by weight or less, it has been possible to produce glass interleaving paper that has excellent performance in preventing glass burn and glass adhesion to the paper surface.

The tests conducted by the above-mentioned inventor will be described below.

The following three types of interleaf paper, A, B, and C, were used in the test.

Paper A: The ratio of used newspaper with a resin fat content (ether extract content, the same applies hereinafter) of 1.2% by weight and ground wood pulp with a resin fat content of 0.6% by weight, respectively.
Conventional interleaf paper with a resin content of 0.5% by weight is made by adding an organic sizing agent to papermaking raw materials of 60% and 40% by weight after disintegration, removal of resin and fat, and removal of foreign substances. .

B paper: For the same papermaking raw material as the A paper,
An interleaf paper with a resin content of 0.26% by weight produced by the method of the present invention without adding an organic sizing agent after defibration, removal of resin and fat, and removal of foreign substances.

C interleaf paper: After disintegrating, removing resin and fat twice, and removing foreign matter from the above-mentioned papermaking raw materials containing 90% by weight and 10% by weight of used newspaper and ground wood pulp, organic matter is removed. An interleaving paper with a resin content of 0.18% by weight produced by the method of the present invention without adding a sizing agent.

Test method: For each slip sheet of A, B, and C,
Using an accelerated testing machine operated at 60℃ and 98 to 100% RH, we tested the degree of burning of the glass and the cloudiness of the glass, which is an indicator of the adhesion of paper skin to the glass, and after wiping the glass. The degree of opacity was observed every 5 days until the 25th, depending on the presence or absence of clouding. still,
For burnt glass, check both the areas where the interleaving paper is in contact and the areas where it is not.
Regarding opacity, both cases where the surface of the interleaf paper was smooth and rough were investigated.

Test results: The following will be explained based on FIGS. 1 to 3. In addition, each mark of ×, ○, △ in the figure is
A slip paper, B slip paper, and C slip paper are shown.

(1) Burning in the area where the interleaving paper was in contact: As shown in Figure 1 A, in the case of A interleaf paper, the degree of burnt reached the allowable value for practical use from the 10th day onwards. On the other hand, in the case of B interleaf paper indicated by the circle in the figure, the degree of burn increases from the 20th day onwards, but
It remained below the allowable value until the 25th, and in the case of C interleaf paper, no burning occurred until the 25th.

(2) Burning in areas where the interleaving paper did not touch: As shown in Figure 1 (b), burns occur on all three papers A, B, and C, but B and C interleaving papers are more sensitive to A.
The degree of burntness is smaller than that of paper.

(3) Clouding when the paper surface is smooth: As shown in Figure 2 A, on the 10th day, the degree of white turbidity in the case of C interleaving paper increased to the same value as that of A interleaving paper, but in other cases. , B and C both have a lower degree of white turbidity than A paper.

(4) Cloudiness when the paper surface is rough: As shown in Figure 2 B, the degree of white turbidity increases in each of the three interleaving papers as the days pass, but in the case of both B and C interleaving papers. Even after 25 days had passed, the degree of white turbidity did not become greater than the degree of white turbidity on the 5th day in the case of A paper.

(5) Transparency when the paper surface is smooth: As shown in Figure 3 A, both B and C interleaf papers have
The degree of opacity is lower than that of A paper.

(6) Transparency when the paper surface is rough: As shown in Figure 3B, the degree of opacity increases for all three papers as the days pass, but in the case of interleaf paper B and C, the degree of opacity increases after 25 days. Even after the passage of time, the opacity did not exceed the level of opacity on the 5th day in the case of A paper.

Conclusion: The lower the resin content of the interleaving paper, the more effective it is in preventing glass burning and paper surface adhesion to the glass. It has been found that the interleaf paper can be put to practical use in terms of preventing burning and adhesion to the paper surface. In addition, even in the case of papermaking raw materials that use a large proportion of waste paper and have a high resin content, the resin content of interleaf paper can be reduced to 0.3% by weight or less by performing the resin removal operation twice. I understood. In other words, when carrying out the method of the present invention, in the case of papermaking raw materials with a low resin content, the resin operation is performed once, and the resin content is reduced.
It has been found that in the case of papermaking raw materials with a high value of 0.5 or more, it is sufficient to carry out the degreasing operation two or three times.

In carrying out the present invention, it goes without saying that a non-organic sizing agent such as bandate sulfate may be added, and based on the results of numerous tests conducted by the present inventor, It is known that the moisture and water absorbency of interleaf paper can be improved by including a large amount of sulfuric acid compounds.

[Brief explanation of drawings]

Fig. 1 A and B, Fig. 2 A and B, and Fig. 3 A and B are graphs showing the test results.

Claims (1)

[Scope of Claims] 1. A method for producing glass interleaving paper using waste paper or waste paper and ground wood pulp as papermaking raw materials, which comprises: disintegrating the papermaking raw materials, removing resin and fat, and removing foreign substances; A method for producing glass interleaving paper without adding an organic sizing agent. 2. The method for producing interleaving paper for glass according to claim 1, wherein the papermaking raw material contains 50% by weight or more of waste paper. 3. The method for manufacturing glass interleaving paper according to claim 1 or 2, wherein the resin removal is repeated multiple times.