JPH02289393A - Removable, pressure-sensitive, adhesive sheet - Google Patents

Abstract

PURPOSE:To minimize the possibility that a removable, pressure-sensitive, adhe sive sheet may be peeled off unexpectedly, and to stably peel it if necessary by bonding the entire area of a joint edge part more firmly than a non-joint part when the sheet is designed. CONSTITUTION:Ethylene/vinyl acetate-based copolymer emulsion of 100pts.wt. on a dry basis as adhesive and synthetic silica of 150pts.wt. as pigment are mixed to adjust the concentration of a solid component to 45%, thereby obtaining an adhesive component. It is applied to wood free paper to produce a pressure-sensitive adhesive sheet. Through the use of a business form printer, information is printed on the application surface of the pressure-sensitive adhesive sheet by typographic printing, a rectangular part on the information printed with adhesion suppressing ink is printed by flexography, and the sheet is perforated as the illustration shows to fold into two parts. After information is printed on the adhesion suppressing ink layer of the sheet and the original surface by an electrophotographic method, the adhesive surfaces are confronted with each other with the perforation as a symmetric axis, and a metallic pressure roll applies pressure to them, thereby producing the sheet shown by the illustration.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pressure-sensitive adhesive postcard that contains a large amount of information and can protect the confidentiality of information.

[Conventional technology]

In recent years, a type of form paper with an adhesive-containing layer on the sheet is printed on the back side using an electrophotographic printer, etc., and then processed into a postcard by placing the adhesive-containing layers facing each other and joining them under pressure. Demand for pressure-sensitive adhesive sheets is expected. However, although these joint-type postcards are convenient because they can be printed on the front and back sides in one printing, the amount of information recorded on them is no different from that of regular postcards, and the confidentiality of information is different from that of envelopes. There is no such security feature.

Furthermore, there is a type of postcard that conceals information. This was designed so that the joined surface could be re-peeled with a relatively weak force, and that surface could also be used as an information column.Therefore, this type of postcard has the characteristic of being able to increase the amount of information. It also has the potential to be used as a postcard that can protect the confidentiality of information.

However, with the products developed so far, if the adhesiveness of the joint surface is set to be slightly weak, peeling tends to occur during unintended handling, and also, if the adhesiveness of the joint surface is set to be slightly strong. In some cases, even if you try to peel off the sheet to see the information on the bonded surface, it may not be possible to peel it off, or even if you try to peel it off, the sheet may be damaged and the information cannot be confirmed, so it is important to balance both adhesion and peelability. This is difficult and is still at a stage where it is difficult to say that it is sufficient.

[Problem to be solved by the invention]

The present invention does not cause peeling at all when unintended (
Moreover, it is an object of the present invention to provide a removable pressure-sensitive adhesive postcard that exhibits stable removability when necessary.

[Means to solve problems]

The present invention provides a removable pressure-sensitive adhesive postcard designed so that sheets can be joined by stacking and applying pressure, and information on the joint surface can be read again by peeling off the joint surface. This removable pressure-sensitive adhesive postcard is characterized in that the entire edge portion or a portion of the joint portion has a greater peeling force than the non-edge portion.

[Effect]

In designing a removable pressure-sensitive adhesive postcard, the present invention suppresses the risk of unintended peeling by adhering the whole or part of the edge part of the joint more strongly than the non-edge part, and This allows stable peeling to be achieved when needed. Among these, it is most preferable to set the whole or part of the edge portion of the bonded portion to be non-peelable, since there is no risk of unintended peeling.

As a means for forming the postcard of the present invention, for example, means for joining sheets having an adhesive-containing layer region and an adhesion-suppressing material layer region to form a postcard is effective. This can be obtained by providing an adhesion-suppressing ink layer on a portion of the adhesive-containing layer that has recorded or is to be recorded.

Examples of the sheet of the present invention include the sheet shown in FIG. 1. This is done by printing information on the adhesive-containing layer (on the back side if necessary), then printing adhesion-suppressing ink on the area excluding the edges, and then making perforations as shown in the figure. After making the left and right sides face each other with the central perforation as the axis of line symmetry, they are joined together using a pressure roll or the like to form a postcard. (Incidentally, printing of information can be carried out if necessary even after printing the adhesion suppressing ink.) What is shown in FIG. 2 is a side view of the sheet shown in FIG. 1, viewed from the arrow side. FIG. 3 shows a postcard obtained by joining the sheets shown in FIG. 1. Internal information that is joined and cannot be seen in this form can be seen by cutting out the perforations and peeling off the joined sheets.

Furthermore, depending on the type of adhesion-suppressing ink or the amount of ink applied, it is possible to construct the sheet targeted by the present invention by applying the adhesion-suppressing ink only on one side of the sheet with the perforation line as the boundary, as shown in FIG. 4, for example. is also possible.

In addition, the sheet of the present invention includes a sheet printed with adhesion suppressing ink as shown in FIG. 5 so that a portion of the edge exhibits strong adhesive properties, and the sheet shown in FIG. This is the postcard I received.

Furthermore, as a more preferable sheet of the present invention, as shown in FIG. 7, there is a sheet in which cut portions are provided to facilitate peeling, and FIG. 8 shows a sheet obtained by joining these sheets. Show the postcard.

The most common form of the present invention, which also has the advantage that there is no risk of sheets being joined incorrectly, is the above-mentioned form in which the sheets to be joined are connected by perforations, etc. However, in another form of the present invention, the sheets to be joined are made of separate sheets.
The one shown in the figure, or the first one with different sizes of both sheets.
) Examples include those shown in the figure. Note that what is shown in FIGS. 10 and 12 is a postcard obtained by joining the sheets shown in FIG. 9 and FIG. 1).

Examples of the adhesive used to form the adhesive-containing layer of the pressure-sensitive adhesive sheet of the present invention include ethylene vinyl acetate resin, acrylic resin, vinyl chloride resin, vinylidene chloride resin, synthetic rubber resin, natural Examples include rubber-based resins. Among these, those with a glass transition point of 11 are preferably used.
00°C to 30°C, particularly preferably -70°C to -20°C.

Pigments are usually added to the adhesive-containing layer, specifically silica, kaolin, clay, calcium carbonate, aluminum hydroxide, zinc oxide, titanium oxide, melamine resin particles,
Examples include benzoguanamine resin particles and starch particles.

These pigments are generally used in an amount of 10 to 500 parts by weight, preferably 30 to 300 parts by weight, based on the adhesive.

In addition, the adhesive-containing layer may further contain rosin resin and its derivatives, terpene resin, coumaron indene resin,
Xylene resin, alkylphenol resin, Cs, and C
Tackifiers such as 9-series petroleum resins, various paraffins, waxes, fatty acids and their derivatives, high alkaline earth metal soaps, mold release agents such as silicones, adhesive-containing capsules and oil capsules to improve adhesion, Auxiliary agents such as antistatic agents, thickeners, dispersants, preservatives, antioxidants, and antifoaming agents may be added.

As the support for the pressure-sensitive adhesive sheet in the present invention, for example, wood-free paper, synthetic paper, coated paper, laminated paper, metal-deposited paper, etc. can be used.

The amount of adhesive composition applied is usually 4 to 20 g/rr? It can be provided by conventionally known coating and printing methods such as air knife coater, blade coater, bar coater, screen printing, and flexographic printing.

In the present invention, the adhesion suppressing substance layer is usually formed by printing an adhesion suppressing ink on a support or an adhesive-containing layer. Examples of the adhesion suppressing substance used in this ink include polydimethylsiloxane, polyphenyl Silicone resins such as methylsiloxane, perfluoroalkyl phosphate esters, fluorine compounds such as copolymers of (meth)acrylates containing fluoroalkyl groups, copolymers of (meth)acrylates containing long-chain alkyl groups, derivatives of higher fatty acids, Examples include waxes such as polyethylene wax and carnauba wax, as well as polyethylene and polypropylene. Among these components, those that are liquid at room temperature or in a heated state can be used as ink as is, but they are usually dissolved or dispersed in water or a non-aqueous medium, and if necessary, binders, pigments, ultraviolet absorbers, etc. Antioxidants, fluorescent dyes, colored dyes, photoinitiators,
Various auxiliary agents known in the ink field such as wax, dryer, thickener, gelling agent, etc. are added to prepare evaporative drying type, radiation curing type, oxidative polymerization type ink, etc.

As the non-aqueous medium, those known in the printing industry can be used as appropriate, but specific examples include benzene, toluene,
Xylene, cyclohexane, hexane, trichlorethylene, ligroin, methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, methanol, ethanol, n-
Propyl alcohol, isopropyl alcohol, n-butanol, n-hexanol, cyclohexanol, 2
-Ethylhexyl alcohol, polyethylene glycol diacrylate, propylene glycol dimethacrylate, pentaerythritol acrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, hexanediol diacrylate, 1゜2-butanediol diacrylate, epoxy Reaction products of resin and acrylic acid, reaction products of methacrylic acid, pentaerythritol and acrylic acid, condensates of maleic acid, diethylene glycol and acrylic acid, methyl methacrylate, butyl methacrylate, styrene, vegetable oils (linseed oil, sunflower oil) drying oils such as soybean oil, semi-drying oils such as soybean oil, non-drying oils such as castor oil), processed oils (dehydrated castor oil, polymerized oils, maleated oils, vinylated oils, urethanized oils), mineral oils (machine oils, spindle oils) etc.

This ink is printed by a known method such as letterpress, offset, gravure, flexography, or screen printing after or before printing the information.

The amount applied varies depending on the nature of the ink used, but it is usually 0.01 to 10 glr dry weight.
It is d.

Information is printed on the front and/or back side of the sheet, and before and/or after the application of the adhesion inhibitor, and the printing methods used include letterpress, offset, gravure flexo, screen, electrophotography, and thermal transfer methods. .

Once coated and printed, the sheet is further perforated, and if necessary, information is printed on it.The sheet is pressed with a strong pressure of 40 to 500 kg/cd with the coated sides facing each other to form a postcard. is formed.

The sheet used in the present invention is most commonly handled as a roll before being coated with an adhesion inhibitor, or as a Z-folded paper after being coated, and then separated from the perforations after being treated with a pressure sealer. It is used as a postcard.

Examples of the present invention will be described below, but it goes without saying that the present invention is not limited only to these Examples. In the examples, unless otherwise specified, parts are parts by weight and %.
% means weight %.

Example-1 An ethylene/vinyl acetate copolymer emulsion (trade name: Sumikaflex 7 manufactured by Sumitomo Chemical Co., Ltd.) was used as an adhesive.
53 (glass transition point: 15°C) (dry weight) and 150 parts of synthetic silica as a pigment (trade name: Mizukashiru P-832, manufactured by Mizusawa Chemical Industry ■, average particle size 3 μm) were mixed to determine the solid content concentration. was adjusted to 45% to obtain an adhesive composition.

This composition was applied to 80 g/rd high-quality paper so that the dry coating amount was 8 g/rd to obtain a pressure-sensitive adhesive sheet.

Next, using a business form printing machine, information was printed by letterpress printing on the coated surface of the pressure-sensitive adhesive sheet, and then
Asahi Guard A as adhesion control ink in flexo printing
C-53 () (fluorine-based oil resistant agent, manufactured by Asahi Glass Co., Ltd.) was printed on the 12.5 CIIX 17.5 cm rectangular part on the printed information so that the dry weight was 0.2 g 10 f, and the perforation was Insert it as shown in the picture and fold it in half.

Next, after printing information using an electrophotographic method on the adhesion-suppressing ink layer and on the base paper surface of the sheet, the perforations are used as symmetry axes to make the adhesive surfaces face each other, and a metal roll for pressure is applied for 10 minutes.
A pressure of 0 kg/ci was applied to obtain a postcard as shown in FIG.

After the postcard was cut at the perforation, the attached sheets could be easily peeled off and the information on the inside could be read.

Examples 2 to 4 Fluorine-based oil resistant agent A(, -550 (Example 2),
AC-650 (Example 3), AC-710 (Example 4)
) was used, except that a postcard was obtained in the same manner as in Example 1, and the same effect as in Example 1 was obtained.

Comparative Example A postcard was obtained in the same manner as in Example 1 except that no adhesion-suppressing ink was printed, but the joined surface could not be peeled off and information on the inner surface could not be confirmed.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a pressure-sensitive adhesive postcard sheet provided with an adhesion-suppressing ink layer on the entire surface of the adhesive-containing layer except for the edges. Fig. 2 is a side view of the sheet shown in Fig. 1 viewed from the direction of the arrow, and Fig. 3 is a side view of the sheet shown in Fig. 1, with the left and right coated surfaces being pressure-bonded using the perforation as an axis of line symmetry. Figure 1 is a schematic diagram showing a postcard obtained by removing the joints by separating the perforations. Also, the fourth
The figure is a schematic diagram showing a pressure-sensitive adhesive postcard sheet in which an adhesion-suppressing ink layer is provided on the left half of the area excluding the edges on the adhesive-containing layer. FIG. 5 is a schematic diagram showing a pressure-sensitive adhesive postcard sheet in which an adhesion-suppressing ink layer is provided on the left half of the area excluding a part of the edge on the adhesive-containing layer, and FIG. 2 is a schematic diagram showing a postcard obtained by pressure bonding the sheets shown in FIG. The sheet shown in Fig. 7 is obtained by cutting one end of the sheet shown in Fig. 4, and the postcard shown in Fig. 8, which is made by joining these sheets together, is made by cutting away the perforations to create a postcard at the joint. JI separation can be easily performed from the cant part. Furthermore, the sheet shown in FIG. 9 is made up of two separate sheets to be joined, and the sheet on the left is provided with an adhesion-suppressing ink layer on the entire surface except for the edges on the adhesive-containing layer. On the other hand, the sheet on the fabric side consists only of an adhesive-containing layer. FIG. 10 is a schematic diagram showing a postcard obtained by joining the sheets shown in FIG. 9. or,
1) The sheet shown in Figure 1 consists of two sheets of different sizes to be joined, and the sheet on the left is coated with adhesion-suppressing ink on the entire surface except for some of the edges on the adhesive-containing layer. The sheet on the right, on the other hand, consists only of the adhesive-containing layer. Moreover, FIG. 12 is a schematic diagram showing a postcard obtained by joining the sheets shown in FIG. 1). 1... 2... 3... 4... 5... 6... 7... 8... 9. ...Support Adhesive Containing Layer Adhesion Suppressing Ink Coated Surface Edge Area Perforation Line Perforation Line Information Cut Area Adhesion Suppressing Ink Layer

Claims (5)

[Claims] (1) In a removable pressure-sensitive adhesive postcard designed to be able to be joined by stacking sheets and applying pressure, and to be able to read the information on the joined surface again by peeling off the joined surface, 1. A removable pressure-sensitive adhesive postcard, characterized in that the entire edge portion or a portion of the edge portion of the postcard has a greater peeling force than the non-edge portion. (2) The removable pressure-sensitive adhesive postcard according to claim (1), wherein the entire or part of the edge portion of the joint is non-peelable. (3) The removable pressure-sensitive adhesive postcard according to any one of claims (1) and (2), wherein the sheet has an adhesive-containing layer region and an adhesion-inhibiting substance layer region. (4) The removable pressure-sensitive adhesive according to claims (1) to (3), wherein the sheet has an adhesion-suppressing ink layer provided on a portion of the adhesive-containing layer provided on the support. postcard. (5) Claim (1) in which the sheets to be joined are connected to each other
) to (4). The removable pressure-sensitive adhesive postcard described in (4) above.