JPH01266299A - Laminated paper for glass - Google Patents

Abstract

PURPOSE:To obtain laminated paper for glass, generating a slight wrinkle in separating laminated glass sheets and making invisible of paper texture in observation of reflection or transmission under fluorescent light, having respectively specific values of areal weight, Beck evenness, fats and oils content, density of laminated paper and pH. CONSTITUTION:A laminated paper for glass suitable for protect of TV cathode ray tube, etc., is obtained by regulating >=65g/m<2> areal weight, <=20sec Beck evenness of the both surfaces of the laminated paper, <=0.3% fats and oils content, <=0.4g/cm<3> density of the laminated paper and 6-7pH.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a glass interleaving paper that is used by being inserted between adjacent laminated glass plates.

[Prior art] The most common glass interleaving paper used in the glass industry has a basis weight of about 35 g/m'', and in the case of interleaving paper used for special quality glass. Some had a basis weight of around 50 g/m2.

There were also cases where sheets with a basis weight of less than 35 g/m2 were obtained and used from sources other than the glass interleaving industry.

Such interleaf paper also contains substances such as resin and fat and sulfur bread crystals, and has a high resin and fat content, for example, exceeding 0.3%. In addition, the surface of the paper is smooth,
For example, the smoothness exceeded 20 seconds. In addition, the density was high, for example, over 0.4 q/am3, and the pH of the interleaving paper was low, for example, less than 6.

[Problems to be Solved by the Invention] However, in such conventional glass interleaving paper, the interleaving paper components contain a large amount of harmful substances such as resin and fat, bread sulfur crystals, and the surface of the interleaving paper is Because the glass was smooth, harmful substances were likely to transfer to the glass surface, creating a papery texture. Also,
Because the paper has a high density, it easily absorbs moisture and wrinkles, and because the pH of the paper is low, chemical reactions tend to occur and form paper plates.

In particular, since the basis weight was small, it was easy to wrinkle.

For this reason, paper texture forms on the glass surface after a normal storage period (about 3 months) under normal storage conditions, and when observed with the naked eye by reflection or transmission under a fluorescent light, the paper texture becomes noticeable. There was a problem.

[Means for Solving the Problems] By the way, there are the following two cases in which the above-mentioned paper texture becomes a problem.

Case 1: The paper surface cannot be removed even by wiping, washing, etc.

Case 2: The above measures are not taken at all, and the existence of visible paper texture is made impossible.

Conventionally, the aim of Case 1 has been to make paper plates easier to remove. In case 2, the problem was not the extremely thin cloudy skin, but rather the appearance of ripples or tiger skin on the paper surface.

The present inventor has found that such a situation is closely related to the formation of wrinkles in the glass interleaving paper, and that the formation of wrinkles is caused in particular by the size of the basis weight, and has accomplished the present invention.

That is, in the present invention, the basis weight is 65 g/m2 or more, the Peck smoothness of the front and back sides of the paper is 20 seconds or less, the resin content is 0.3% or less, the paper density is 0.04 g/cm3 or less,
The interleaving paper has a pH of 6 to 7.

According to the present invention, it is necessary that the basis weight is 65 c]/m2 or more. Materials with a basis weight of 60 g/m2 or less tend to wrinkle, and the shape of the wrinkles becomes sharp. on the other hand,
If the basis weight exceeds, for example, 70 g/m2, wrinkles will not form easily and the shape of the wrinkles will be dull.

Furthermore, according to a whiteness investigation using a projector, in the evaluation of the glass bottom surface, the improvement becomes more remarkable as the basis weight increases. For example, a material with a basis weight of 80 Ω/m2 can stably meet the target quality. On the other hand, in the evaluation of the glass top surface, there is no difference between glass tops with a basis weight of 35 g/m2 to 70 g/m2, but those with a basis weight of 80 CI/m2 consistently meet the target quality.

In addition, when evaluating by reflection or transmission under a fluorescent light, paper texture is not visible at all when the basis weight is 60g/m2 to 80g/m2, but when the basis weight is 35+/m2 to 5Og/m2, the surface of the paper is not visible at all. It looks faint.

In addition, in the evaluation of the ease of removal of paper plates, in the case of glass bottom surfaces, those with a basis weight of 35 g/m2 to 50 g/m2 cannot achieve the target quality, but those with a basis weight of 60 g/m2
2 or more can achieve the target quality.

[Effect] From the above, those with a basis weight of 65 CI/m" or more,
Target quality can be achieved. That is, the paper does not wrinkle easily, the wrinkle shape is dull, and the paper surface is not visible when observed with the naked eye by reflection or transmission under a fluorescent light.

[Examples] Hereinafter, in order to clarify the present invention more specifically, the present invention will be described in detail, but the present invention is not limited in any way by the description of the Examples.

First, a paper wrinkle generation test was conducted.

The test sample had a Peck smoothness of 20 on the front and back sides of the paper.
sec or less, the resin content is 0.3% or less, the paper density is 0.4 g/cm3 or less, the paper pH is 6 to 7, and the basis weight is 35q/m2, 50g/m2, 60g/
Five types of materials were prepared, each of which was changed to m, 70Q/m2, and 80q/m2.

In order to investigate the occurrence of paper wrinkles, a weathering test was conducted under the following conditions. That is, using a weathering tester, dry-wet and wet-dry cycles were applied every 6 hours, every 12 hours, and every 24 hours under the conditions of dry 35 ° C 150% RH, wet 35 ° C, 100% RH 1. Ta.

The results of the above weathering test are shown in Table 1.

As is clear from Table 1, those with a basis weight of 60 g/m2 or less tend to wrinkle easily, and the wrinkles are sharp3.
In addition, those with a basis weight of 70 g/m 2 were less likely to wrinkle, and the shape of the wrinkles was dull.

When the basis weight was 80 g/m2, wrinkles were less likely to form, and the wrinkle shape was also rough.

Next, observation with the naked eye was performed by reflection or transmission under a fluorescent light.

The observation results are shown in Table 2. As is clear from Table 2,
Items with a basis weight of 60CI/m" to 80CJ/m" are
There were no paper plates in sight. On the other hand, the basis weight is 35g/m ~
In the case of 50 g/m2, the paper surface was faintly visible.

Next, the whiteness was evaluated using a projector (750W).

That is, the glass bottom surface and glass top surface of the front, center, and back of the glass laminate were evaluated separately after 15 days, 30 days, and 45 days.

The evaluation results are shown in FIG. 1 (A-E, A''-E-).

In Fig. 1, the mark ・ indicates the glass bottom surface and the glass top surface at the front of the glass laminate, the Δ mark indicates the glass bottom surface and the glass top surface at the center of the glass laminate, and the X mark indicates the glass bottom surface and top surface of the glass laminate. The glass bottom surface and the glass top surface in the inner part are shown, respectively, and the dotted line shows the target value. Also, (A),
(8-) has a basis weight of 35ch/m2, (B), (B
-) has a basis weight of 50c+/m2, (C), (C-)
(D>, (D-) are those whose basis weight is 70 Q/m2, (E), (E-) are those whose basis weight is 80 g/m2. shows.

As is clear from Figure 1, in the evaluation of the glass bottom surface, as the basis weight increases, the improvement in whiteness becomes more noticeable, and when the basis weight reaches 80(]/m2, the target quality is stably achieved. Cleared.

On the other hand, in the evaluation of the glass top surface, the basis weight was 35g/m
There is not much of a difference for products up to ~70g/m2, but those with a basis weight of 80g/m2 consistently meet the target quality.

Next, the ease with which the paper surface could be removed was investigated.

That is, the ease of removing paper plates from five types of samples was investigated on the glass bottom surface and the glass top surface after 15 days, 30 days, and 45 days, respectively.

The survey results are shown in Figure 2 (I-D). Figure 2 (A) is
Figure 2 (B) shows the evaluation of the glass top surface with a basis weight of 60 to 80 g/m2.
The evaluation of g/m2 and 50 g/m2 is shown in Figure 2 (
C) has a basis weight of 60g/m2 to 80g at the glass bottom surface.
Figure 2 (D> shows the evaluation of glass bottom surface weights of 35 g/m2 and 50 g/m2. 3
5Q/m2, the mouth mark has a basis weight of 50 (77m2), the ・ mark indicates a basis weight of 60g/m2, the Δ mark indicates a basis weight of 70
q/m2, and the mark X indicates a basis weight of 80 CJ/m''. In addition, in FIG. 2, the dotted line indicates the target value.

As is clear from Figure 2, when evaluating the glass bottom surface, those with a basis weight of 351/m2.50 (7/m2) slightly exceeded the target quality, and those with a basis weight of 60CJ/m2 were slightly better. Those with a basis weight of 70 g/m 2 or 80 g/m 2 were stable and good.On the other hand, in the evaluation on the glass top surface, all five types were good.

As mentioned above, by integrating the paper wrinkle formation, reflection or transmission evaluation under fluorescent light, whiteness evaluation using a projector (750W), and evaluation of ease of paper texture,
If the basis weight is 65 g/m2 or more, the target quality can be met.

Note that the interleaf paper according to the present invention is not limited to use by being inserted between adjacent laminated glass plates, but is also applicable to TV cathode ray tubes,
It is also effective for protecting metal surfaces, resin plates, etc. Also, p
Since H is 6 to 7, which is higher than that of conventionally used interleaf paper, it contains less sulfur and is effective in preventing blackening of silver paste, for example.

Table 1 Table 2 [Effects of the Invention] As explained above, according to the present invention, wrinkles do not easily appear, the shape of the wrinkles is dull, and when observed with the naked eye under a fluorescent light, the paper I can't see the plate.

[Brief explanation of the drawing]

Figure 1 (A-E, /M-E-) shows the projector (75
0W> graphs showing whiteness evaluation, Figure 2 (A-D
) are graphs showing evaluations of ease of picking up paper plates. Patent applicant: Nippon Sheet Glass Co., Ltd. Representative Patent attorney: Sabetsu Miyauchi

Claims (1)

[Claims] The basis weight is 65 g/m^2 or more, the Peck smoothness of the front and back sides of the interleaf paper is 20 seconds or less, the resin content is 0.3% or less,
The density of the paper is 0.4g/cm^3 or less, and the pH of the paper is 6 to 7.
A glass interleaving paper characterized by being configured so that.