JPS59149970A - Pressure-sensitive adhesive paper - Google Patents

Abstract

PURPOSE:To obtain a pressure-sensitive adhesive paper having excellent adaptability to electrostatic duplication, magnetic duplication, etc., by adjusting the ratio of elongation or shrinkage factor of the cover paper to the release paper of said adhesive paper to a value within the specified range. CONSTITUTION:A pressure-sensitive paper in which the ratio of elongation and/ or shrinkage factor of the cover paper to the release paper is 0.7-1.0:1.0. By making the degree of shrinkage of the release paper 30% at maximum larger than that of the cover paper in the shrinkage balance between the cover paper and the release paper in this pressure-sensitive adhesive paper, curling after copying can be reduced. Further, by making the degree of shrinkage of paper per se 0.90% or below, pref. 0.80% or below in a crossiwise direction (in the direction perpendicular to the flow of paper making during manufacturing), an increase in curling due to changes in environment can be inhibited. Substrates used for the cover paper and the release paper of the pressure-sensitive adhesive paper can be chosen among those satisfying the condition of the degree of shrinkage of 0.90% or below, taking the shrinkage balance between the cover paper and the release paper into consideration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to adhesive paper used for static copying, magnetic copying, general office use, etc.

Top paper 1 as shown in FIG. Conventional adhesive paper consists of a pressure-sensitive adhesive 2 and a release paper having a release surface.

(1) High-quality paper is used for the top paper and glassine paper is used for the release paper base.

(2) Both the upper paper and the release paper base material are made of high-quality paper.

etc.

However, in the former case, the release paper shows greater elongation than the top paper in a high humidity environment and thickens (curls) on the top paper side, and in a low humidity environment the release paper shows greater shrinkage than the top paper and Ogi (
The paper curls, and when an image is formed using a 4i copying machine, the feeding characteristics and transfer characteristics are unstable, resulting in continuous feeding and transfer failures.

In the latter case, the expansion/contraction rate of the top paper and release paper is equal or the top paper is larger (top paper expansion/contraction rate/release paper expansion/contraction rate = 1.0 or more), or the paper compression ratio of the top paper and release paper is Since the ratio is large at around 1.2%, when both sides are exposed to high humidity and low humidity environments F, it will not curl as much as the adhesive paper of the former combination of glassine paper, but in a laminated state. If only one side is exposed, the curl will increase due to the expansion and contraction of the exposed side, and when fixing with a heat fixing roll, the upper paper side on which the image is placed is heated by the heat roll, so the upper paper side will shrink. It becomes thick (curl) that occurs during fixing (hereinafter referred to as post-copy curl).

), which causes poor feeding in a copying machine. Therefore, an object of the present invention is to provide adhesive paper that has excellent copying suitability for static copying, magnetic copying, and isopressure copying. There is a particular thing.

The inventors of the present invention have solved the drawbacks of the conventional adhesive paper (as a result of repeated studies, the amount of change in curl can be controlled by selecting the paper compression ratio of the top paper and release paper and the balance thereof). With this discovery, the present invention was completed.

In other words, one aspect of the present invention is to use a combination of adhesive paper in which there is no difference in paper compression ratio between the top paper and release paper, or where the top paper has a small expansion/contraction ratio, and the paper compression ratio of the top paper and release paper itself is small. From Dokoto K, Copyright Don.

It provides adhesive paper that is especially suitable for feeding.

To explain in more detail, 1 the present invention is characterized in that the elongation rate and/or shrinkage weight ratio of the top paper and release paper is 0.7 to 1.0.
: 1.0, and the elongation rate and/or shrinkage rate of the release paper is 0.90% or less.

The method for measuring paper compression ratio in the present invention is to cycle humidity (R, H,) under low load conditions from 65 inches to 90 degrees to 65%.
The expansion/contraction ratio when changed as →20% →65% is calculated from the following formula. In this case, sample 7' was pre-humidified for 24 hours at 20°C and 65% R, H, ill.
No. 747) and the above cycle.

Elongation rate = E1 + E2 (chi) Shrinkage rate = 51 + 52 (%) E1 = Elongation rate from 65%R, H, to 90cm R,H' (E2 = 20%R,H, to 65%R, Elongation rate (%) of H, s1 = c + o% R, H, to 65 inches, shrinkage rate (%) of R, H, s2 = 65% R, H, to 20% R, H,
Shrinkage rate (In the adhesive paper of the present invention, the expansion/contraction balance between the top paper and the release paper, the release paper is up to 30 times thicker than the paper) (
By doing so, curling after copying is reduced, and the paper compression ratio itself is 0.90% or less, preferably 0.80% or less in the lateral and direction (P direction perpendicular to the paper flow during # making). F is used to suppress the increase in curl caused by environmental changes.

The top paper and release paper base material used in the adhesive paper of the present invention are selected from those that satisfy the above-mentioned paper compression ratio of 0.90% or less, taking into consideration the expansion/contraction balance of the top paper and release paper. You can choose.

In addition, the same kind of paper is used as the top paper and release paper base material,
If the paper compression ratio when the release paper base material is subjected to the release treatment is greater than the paper compression ratio of the release paper base material alone, such a combination can also be selected.

In addition, for paper with a stretch rate of 0.90% or less, select paper with a small stretch rate such as single gloss paper from commercially available paper (Japanese Patent Laid-Open No. 55
-129475) Containing a water-resistant synthetic resin in one paper (Japanese Patent Application Laid-open No. 129474/1983).

Adjustment of pulp composition and beating conditions, adjustment of filler composition, and fiber orientation according to papermaking conditions.

By adjusting the density etc.! ! ! can do. These papers can be used as is for the top paper for labels. Further, by using these papers as a base material and subjecting them to release treatment, they can be used as release papers.

Will it be implemented next? A detailed explanation of the present invention will be given with reference to +1 and comparative examples.
Freeness 2 of hardwood kraft pulp (LBKP)
It was beaten to 50m1 (NBKP/LBKP = 20/80), and talc (10% based on the pulp), sizing agent, and sulfuric acid band were added to make it 1 tsubo - 4451/r.
r? Label base paper was made, and a small amount of polyvinyl alcohol (PVA) 0.4 F/- containing a conductive agent was coated to obtain a label paper.

Tsuboku 50f/W in the same way as label paper? A base paper for release paper is made, and P'VA O, 8t/n? Further, addition reaction type silicone 9.8 f/l♂ was applied using a gravure coater and dried by heating at a temperature of 150°C to obtain a release paper.

An adhesive paper was obtained using the above label paper and release paper, and using -r acrylic adhesive as an adhesive.

Table 1 shows the expansion/contraction ratio of the top paper and release paper, curling properties in low humidity and high humidity environments, and copy test results using an electrostatic copying machine.
Shown below. Example 2 NBKP (!: Freeness 370 ml of LBKP
(NBKP/LBKP=10/90), and add urea resin to the pulp in an amount of 2.2% by weight to 50t/rf? Paper is made from paper, and the label paper is made into paper (
)Ta.

Freeness 320 ml of NBKP and LBKP (NB
Beat to KP /LBKP= 10/90) and stitch 1 tsubo 5
Paper of 2.3 f/- was made, and a base paper for release paper was obtained by applying 0.9 weights of Evokiku-based polyamide side fat to the pulp. PVA0.5 f/rr for this? Apply.

Furthermore, a release paper was obtained by applying 0.8 t/'- of condensation reaction type silicone.

The adhesive paper was tested in the same manner as in Example 1, and the results are shown in Table 11.

Example 3 Shin-etsu pulp-made single gloss craft (basis weight 52.3 f/n?
) PVA is applied at 0.5t/- on the glossy surface, and addition reaction silicone is applied at 0.79/lr? A release paper was obtained by coating.

Use the top label paper from Example 2 and the release paper above.

Adhesive paper was obtained using an acrylic pressure-sensitive adhesive as the adhesive. This adhesive paper was tested in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 The top paper was India Paper Honshu Paper's Corona S (94 tsubo
79/n? ) was used as a release paper, and PVA was added to &maglasine paper manufactured by Honshu Paper Industries (basis weight 649/n?) as a release paper.
．． 4M/m' coated, and further 0.4M/m' of condensation reaction type silicone.
8f/lt? The one obtained by coating was used.

An adhesive paper was obtained using the above label paper, a release paper, and an acrylic pressure-sensitive adhesive as an adhesive.

Table 1 shows the results of testing this adhesive paper in the same manner as in Example 1.
As shown in Comparative Example 2, the label top paper and 1 were formed paper made by Oji backing paper (basis weight 5
2.3t/rr? ) was used as the release paper, and the release paper was a foam paper made by Shikoku Paper Industries (Tsubo 52.3F/lr?) with PVA applied 1. Of/- coating and further addition reaction type silicone at 0.
89/- was used.

An acrylic pressure-sensitive adhesive was used as the above-mentioned label top paper, release paper, and adhesive to obtain adhesive paper. The results of testing this adhesive paper in the same manner as in Example 1 are shown in Table 1. From the results in Table 1, the adhesive papers according to the present invention (Examples 1 to 3) had good curling properties and feeding properties in electrostatic copying machines. It is clear that these are superior to the conventional ones (Comparative Examples 1 and 2) in terms of.

[Brief explanation of drawings]

The drawing is a sectional view showing the structure of adhesive paper. Code in the figure:

Claims (1)

[Claims] l) The paper is characterized in that the ratio of elongation and/or shrinkage of the top paper and the release paper is 0.7 to 1.0: 1.0. wood adhesive paper. 2) The adhesive paper according to claim 1, wherein the release paper has an elongation rate and/or a shrinkage rate of 0.90% or less.