JPH11301149A - Pressure sensitive pseudo adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a pressure sensitive adhesive force by dispersing a water- soluble resin emulsion having a weight ratio of a specific range in an acrylic ester having a glass transition point of a specific range and a glass transition point in case of mixing with a water-soluble resin emulsion of other specific range in a pressure sensitive adhesive layer. SOLUTION: A water-soluble resin emulsion of 50 to 500 pts.wt. is dispersed in 100 pts.wt. of an acrylic ester having a glass transition point of -90 to 50 deg.C and a glass transition point in the case of mixing with the emulsion of -80 to 20 deg.C in a pressure sensitive adhesive 3. Thus, when a protective colloidal water-soluble resin emulsion is dispersed in the acrylic resin ester, a water-soluble resin is moved to a surface of a coating layer to match an evaporation of a moisture or the like in a drying step at the time of coating. Then, since a layer containing much water-soluble resin component is formed on the surface of the coating layer of the adhesive 3, occurrence of a blocking or the like can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a delivery slip, a confidential postcard,
The present invention relates to an inexpensive, removable pressure-sensitive pseudo-adhesive sheet that can be used for address labels and the like and that can clearly read printed or printed information.

[0002]

2. Description of the Related Art Conventionally, a general delivery slip has a configuration in which a plurality of delivery sections including at least a delivery section and a receiving section are overlapped and stapled, and delivery information is written in a higher-order slip. Then, a copy structure is provided so that the lower-order slip can be copied and entered.

As an information transmitting means having such delivery information, a device using a pressure-sensitive pseudo-adhesive sheet, which is exemplified in Japanese Patent Application No. 8-326355, has been invented and actively used.

[0004] A pressure-sensitive pseudo-adhesive sheet has a so-called non-peelable pressure-sensitive adhesive base such as natural rubber or synthetic rubber and an adhesive force of the pressure-sensitive adhesive base on at least a part of one side of a base sheet. A layer of a pressure-sensitive adhesive composed of a fine particle filler that suppresses odor is provided, and generally has a function of temporarily adhering but easily peeling off when necessary.

The pressure-sensitive adhesive deteriorates with time (hereinafter referred to as aging phenomenon) as represented by yellowing, a decrease in adhesive strength, and curing. Natural rubber, in particular, has a performance change due to the aging phenomenon. Remarkable. Generally, the aging phenomenon of the pressure-sensitive adhesive is mainly caused by oxidation due to contact with atmospheric oxygen and absorption of ultraviolet rays. In addition, the fine particle filler is usually compounded in the pressure-sensitive adhesive layer, but there is a problem that the bonding strength is not stable depending on the amount of the fine particle filler and the dispersion state. Further, the mechanical stability at the time of adjusting the pressure-sensitive adhesive is poor, and there is also a problem in suitability for application to the base sheet. Therefore, conventionally, in a pressure-sensitive pseudo-adhesive sheet, an antioxidant and an ultraviolet absorption inhibitor for preventing oxidation of the pressure-sensitive adhesive are added to the pressure-sensitive adhesive layer.

Further, a tackifier, a surfactant, a thickener, a defoaming agent, a release agent, and the like are added to the same pressure-sensitive adhesive layer in order to improve the applicability of the pressure-sensitive adhesive. There is a disadvantage that the production cost is increased and the advantage of using inexpensive materials is lost.

In recent years, with the rapid increase in demand for communication means requiring such delivery information, it has been required to print information on a high-efficiency and high-quality pressure-sensitive pseudo-adhesive sheet. The method of printing information on the pressure-sensitive pseudo-adhesive sheet has been shifting from printing with an impact printer, which was conventionally used in combination with a computer, to printing using an electrophotographic method or an inkjet recording method with a computer, and toner retransfer. In addition, problems such as ink bleeding have occurred.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a stable pressure-sensitive adhesive force, suppress the stickiness of the pressure-sensitive adhesive applied layer, prevent blocking during processing, and improve printability. It is an object of the present invention to provide a pressure-sensitive pseudo-adhesive sheet having excellent pressure-sensitive pseudo-adhesive performance that is excellent in removability and can be selected from any material to be bonded.

[0009]

The inventors of the present invention have conducted intensive studies and as a result, the above-mentioned objects have been achieved in that the pressure-sensitive adhesive layer comprises at least an acrylic ester (A) and a water-soluble resin emulsion (B). A layer containing an acrylic resin emulsion pressure-sensitive adhesive base as a main component and a fine particle filler as a basic component, and a glass transition point of an acrylate ester in a range of -90 to 50 ° C, and water solubility. The glass transition point when mixed with the resin emulsion is in the range of −80 to 20 ° C., and a mixture in which 5 to 500 parts by weight of a water-soluble resin emulsion is dispersed with respect to 100 parts by weight of an acrylate ester.

More preferably, the pressure-sensitive adhesive layer of the pressure-sensitive pseudo-adhesive sheet and the adhesive sheet are superimposed and re-peelable and pseudo-adhered to each other at a T-peel strength of 20 ° C.
According to the measurement based on JIS K6833 in an environment of 5% RH, it was found that a pressure-sensitive pseudo-adhesive sheet having a peel strength of 10 g / 25 mm or more can be achieved.

In the present invention, an acrylic resin emulsion containing an acrylic acid ester and a water-soluble resin emulsion as main components is used as a pressure-sensitive adhesive base because a water-soluble resin emulsion formed into a protective colloid is dispersed in an acrylic resin ester. By causing the water-soluble resin to move to the surface of the coating layer in accordance with the evaporation of moisture and the like in the drying step during coating on the surface of the coating layer of the pressure-sensitive adhesive,
Since the layer containing a large amount of the water-soluble resin component is formed on the surface of the applied layer of the pressure-sensitive adhesive, the pressure-sensitive pseudo-adhesive sheet coated with the pressure-sensitive adhesive of the present invention prevents the occurrence of blocking or the like, or This is because the function of preventing the pressure-sensitive adhesive from sticking to the surface of the coating layer is exhibited.

In the present invention, a pseudo-adhesive which can be re-peeled by adding a fine particle filler to a pressure-sensitive adhesive base comprising an acrylic resin emulsion containing an acrylic acid ester and a water-soluble resin emulsion as main components. Performance can be more effectively expressed.

The mechanism is to use an acrylic resin in an emulsion state on the surface of the fine-particle filler by using the fine-particle filler, and in the drying step,
By developing a configuration in which the pressure-sensitive adhesive component is exposed on the surface of the fine-particle filler, and applying a pressure-sensitive adhesive containing the fine-particle filler with the adhesive component exposed on the surface, the surface of the coating layer becomes finer. Irregularities due to the particle filler are formed, the irregularities shift when a predetermined pressure is applied, the surface of the pressure-sensitive adhesive layer becomes flat, and the bonding surface changes from point bonding due to unevenness to surface bonding and it can be re-peeled Glue.

Although the pseudo-adhesion mechanism in this case is not clear, self-diffusion of the polymer resin, dipole force, hydrogen bonding,
Alternatively, it is considered to be due to an adhesion mechanism such as entanglement between the physical polymer resin and the substrate surface.

The fine particle filler used in the present invention is preferably hydrophilic and has an average particle diameter in the range of 1 to 20 μm. When the average particle size is less than 1 μm, the fine particle filler tends to fall off from the pressure-sensitive adhesive applied layer, and when the average particle size is 20 μm or more, the protrusions of the pressure-sensitive adhesive applied surface become remarkable and sufficient feeling is obtained. There is a possibility that adverse effects such as a lack of pressure bonding force may be caused.

The average particle size of the fine particle filler is generally represented by the average value of the size of one particle. For example, fine particles such as silica form a group and form one particle. When the particles behave like particles, the particle population (2
(Next particle).

The compounding ratio of the water-soluble resin emulsion dispersed in the acrylate used in the present invention is preferably such that the water-soluble resin emulsion is dispersed in an amount of 5 to 500 parts by weight per 100 parts by weight of the acrylate. . If the compounding ratio is less than 5 parts by weight or 500 parts by weight or more, there is a possibility of causing problems such as occurrence of blocking or insufficient expression of adhesive strength. More preferably, a water-soluble resin emulsion is dispersed in an amount of 5 to 200 parts by weight with respect to 100 parts by weight of an acrylate ester.

Therefore, in the present invention, at least 5
It is preferred that about 500 parts by weight of the water-soluble resin emulsion is dispersed in the acrylate. More preferably, the glass transition point is −
The glass transition point when the acrylate in the range of 90 to 50 ° C. is mixed with the water-soluble resin emulsion is −
It is preferably in the range of 80 to 20 ° C.

The mixing ratio of the pressure-sensitive adhesive and the fine particle filler used in the present invention is as follows.
It is preferable that the fine particle filler is contained in an amount of 5 to 200 parts by weight based on 0 parts by weight. If the compounding ratio is less than 5 parts by weight, the printing or printing suitability is insufficient, or if it is 200 parts by weight or more, the fine particle filler is easily peeled from the applied layer of the pressure-sensitive adhesive or has a sufficient adhesive force. May not be exhibited.

Therefore, in the present invention, at least 5
It is preferred to use the fine particle filler in the pressure-sensitive adhesive in an amount of up to 200 parts by weight.

The fine particle fillers used in the pressure-sensitive adhesive of the present invention include silica, charcoal, kaolin, clay, talc, aluminum hydroxide, titanium oxide, zinc oxide, activated clay, starch particles, cellulose particles, and styrene. It can be appropriately selected and used from inorganic or organic known fine particle fillers such as resin particles, acrylic resin particles, urea resin particles, microcapsules, oil capsules, polyethylene, and vinyl chloride. I can do it. These fine particle fillers may be used alone or in combination of two or more.

When two or more kinds are used in combination, irregularities due to the fine particle filler on the pressure-sensitive adhesive applied surface can be made discontinuous, and the pressure-sensitive adhesive property can be easily adjusted.

In the present invention, it is preferable that a hydrophilic, more preferably non-thermoplastic, fine particle filler is contained in the acrylic resin emulsion.

The water-soluble resin emulsion to be dispersed in the acrylate used in the acrylic resin emulsion of the present invention includes polyvinyl alcohol, carboxymethyl cellulose, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, ethylene-maleic anhydride copolymer, It can be appropriately selected from known water-soluble polymers such as a styrene-maleic anhydride copolymer, a methyl vinyl ether-maleic anhydride copolymer, and an isobutylene-maleic anhydride copolymer.

These resins may be used alone or
More than one type may be used in combination. By using two or more types of water-soluble resins, it becomes easy to adjust the glass transition point in the range of −80 to 20 ° C. when the acrylate and the water-soluble resin emulsion are mixed.

In the present invention, UV resistance, printability,
It is most preferable to use a styrene-maleic anhydride copolymer excellent in blocking resistance and the like for stabilizing quality.

If necessary, the pressure-sensitive adhesive may further include a surfactant, an antifoaming agent, a thickener, a water-proofing agent, a dispersant, an ultraviolet absorber, an antioxidant, an antistatic agent, and an ink fixing agent. Auxiliary agents such as a dye fixing agent, a fluorescent dye, a colored dye, a lubricant, a deodorant, a deodorant, and an antibacterial agent can also be added.

The pressure-sensitive adhesive property of the pressure-sensitive adhesive layer in the present invention is such that the T-peel strength of the boundary surface where the pressure-sensitive adhesive layer and the sheet to be bonded are superimposed and re-peelable is 300.
mm / min, JIS under the environment of 20 ° C and 65% RH
When measured based on K6833, the peel strength is preferably 10 g / 25 mm or more, particularly preferably 20 to 120 g / 25 mm. When the T-type peel strength is 10 g / 25 mm or less, spontaneous peeling may occur and 120 g / 25 mm In the above case, the printed or printed information may be damaged at the time of re-peeling, or peeling may not be possible.

It is difficult to adjust the re-stripping strength only by the mixing ratio of the water-soluble resin emulsion dispersed in the acrylate, the mixing ratio of the fine particles, and the addition of the auxiliary. The combination ratio of the water-soluble resin emulsion to be dispersed, the combination ratio of the fine particles, and the addition of an auxiliary are combined, and the glass transition point when the water-soluble resin emulsion is dispersed in the acrylate is in the range of -80 to 30 ° C. It becomes easy by adjusting to. By the way, when the glass transition point is out of this range, the stability with time is inferior, and the stress absorption under pressure is greatly reduced, so that it may be difficult to achieve both peelability and adhesiveness.

As the base material used in the present invention, for example, high quality paper, medium quality paper, recycled paper, art paper, coated paper, lightly coated paper, synthetic paper, film, laminated paper, metallized paper and the like are used. I can do it.

In the present invention, the pressure-sensitive adhesive is applied to the substrate by using a conventionally known coating machine or printing machine such as a blade coater, an air knife coater, a bar coater, a roll coater, a gravure printing machine or a screen printing machine. Can be used.

In the present invention, the amount of the pressure-sensitive adhesive to be applied to the substrate is usually preferably about ² to ²⁰ g / m ^{2 in} order to develop an appropriate adhesive force.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The pressure-sensitive adhesive of the present invention is obtained by mixing an acrylic resin emulsion pressure-sensitive adhesive base containing an acrylate ester and a water-soluble resin emulsion as main components, and preferably fine particles, and mixing the mixture. It is possible to easily adjust the adhesive strength by mixing and containing an auxiliary as a basic component and adjusting the glass transition point when the water-soluble resin emulsion is dispersed in the acrylate ester in the range of -80 to 30 ° C. it can.

After the pressure-sensitive adhesive of the present invention is applied to a predetermined portion of the base material and dried, the portion where the pressure-sensitive adhesive is applied and the portion to be bonded are opposed to each other, and a predetermined pressure is applied to the pseudo-adhesive. Can be glued. Further, since the surface of the coating layer of the pressure-sensitive pseudo-adhesive has good information recording suitability such as printing and printing, it becomes a pressure-sensitive pseudo-adhesive sheet on which information can be recorded.

[0035]

The pressure-sensitive pseudo-adhesive sheet of the present invention has a stable adhesive force and suppresses the stickiness of the surface of the adhesive layer, so that it does not cause blocking or the like, and has excellent printability. Since the material to be bonded is not selected, the range of selection of the material to be bonded is increased and the range of application is expanded. Further, the pressure-sensitive pseudo-adhesive sheet of the present invention is a heat-sensitive paper,
Inkjet paper, thermal transfer paper, no-carbon paper,
It can be used as coated paper, high-quality paper, or the like, or can be combined with these papers, or can be coated with an adhesive or the like on the back surface, and can be used in combination with various base materials.

[0036]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Unless otherwise specified, “parts” and “%” described below mean “parts by weight” and “% by weight”, respectively.

Embodiment 1 100 parts (dry weight) of an acrylate ester (glass transition point is −50 ° C.) as an adhesive base and 50 parts (dry weight) of a styrene-maleic anhydride copolymer were mixed, and the glass transition point was adjusted to 10 ° C. It was adjusted.
Synthetic silica having an average particle diameter of 7 μm (Carplex 80
D: Shionogi & Co., Ltd.) to obtain the desired pressure-sensitive adhesive. Next, this pressure-sensitive adhesive composition was
It was applied to 27.9 g / m ² high-quality paper so that the application amount was 10 g / m ² (dry weight) to obtain a pressure-sensitive pseudo-adhesive sheet. Using this sheet, the evaluation results of adhesive strength, printability, non-impact printing suitability (hereinafter referred to as NIP suitability), and blocking property are shown in Table 1 below.
Shown in

Adhesive force: After the sample was left in an environment of 20 ° C. and 50% RH for 12 hours or more, a mail sealer (MS) was used.
-9100: manufactured by Dai Nippon Printing Co., Ltd.) and pressure-bonded with a roll gap of 14 (140 μm).
A mold release test was performed based on JIS K6833.

UV deterioration test: The sample was forcibly irradiated with ultraviolet light for a predetermined time using a UV irradiator, and was irradiated at 20 ° C. and 50% R.
After being left in an environment of H for 12 hours or more, evaluation was performed in the same manner as in the case of the adhesive strength.

Printing suitability test: Using an offset printing machine, ink bleeding and image reproducibility when printed on the adhesive layer of the pseudo-adhesive sheet were visually observed and evaluated.・ Those with good image reproducibility → ○ ・ Those with poor image reproducibility → ×

Non-impact printing suitability test:
Using a non-impact printer (F-6762D: manufactured by Fujitsu Ltd.), the transferability of the image and the like were visually observed and evaluated.・ Those with good image reproducibility and running performance without blurring etc. →
○ ・ Image reproducibility is not a problem, but runnability is poor → △ ・ Image reproducibility and runnability are poor, and faintness and dirt are generated → ×

Blocking evaluation test: Evaluation was made by stacking 50 samples, applying a predetermined load in an environment of 20 ° C. and 65% RH, leaving them standing, and removing them by hand 24 hours later.・ No blocking etc. → ○ ・ Some blocking occurs but can be easily removed by hand → △ ・ Blocking → ×

Embodiment 2 FIG. 100 parts (dry weight) of an acrylate ester (glass transition point is -50 ° C.) as an adhesive base and 100 parts (dry weight) of a styrene-maleic anhydride copolymer were mixed, and the glass transition point was -30 ° C. Was adjusted. 50 parts of synthetic silica having an average particle diameter of 7 μm (Carplex 80D: manufactured by Shionogi & Co., Ltd.) are mixed,
The desired pressure-sensitive pseudo-adhesive was obtained. The obtained pressure-sensitive adhesive was applied to high quality paper in exactly the same manner as in Example 1 to obtain a pressure-sensitive pseudo-adhesive sheet. For the obtained sheet, the adhesive strength,
Table 1 shows the results of evaluating printability, NIP suitability, and blocking properties.

Embodiment 3 FIG. As an adhesive base, 100 parts (dry weight) of an acrylate ester (glass transition point is −50 ° C.) and 100 parts (dry weight) of an ethylene-maleic anhydride copolymer are mixed, and the glass transition point is −30 ° C. Was adjusted. 40 parts of synthetic silica having an average particle diameter of 7 μm (Carplex 80D: manufactured by Shionogi & Co., Ltd.) are mixed,
The desired pressure-sensitive pseudo-adhesive was obtained. The obtained pressure-sensitive adhesive was applied to high quality paper in exactly the same manner as in Example 1 to obtain a pressure-sensitive pseudo-adhesive sheet. For the obtained sheet, the adhesive strength,
Table 1 shows the results of evaluating printability, NIP suitability, and blocking properties.

Embodiment 4 FIG. As an adhesive base, 100 parts (dry weight) of an acrylate ester (glass transition point is −50 ° C.) and 43 parts of vinyl acetate are mixed to obtain a glass transition point of −
The temperature was adjusted to 35 ° C. Forty parts of synthetic silica (Carplex 80D: manufactured by Shionogi & Co., Ltd.) having an average particle diameter of 7 μm were mixed to obtain a target pressure-sensitive pseudo-adhesive. The obtained pressure-sensitive adhesive was applied to high quality paper in exactly the same manner as in Example 1 to obtain a pressure-sensitive pseudo-adhesive sheet. Table 1 shows the results of evaluating the adhesive strength, printability, NIP suitability, and blocking property of the obtained sheet.

Comparative Example 1 100 parts (dry weight) of an acrylate (glass transition point is −50 ° C.) as an adhesive base and 300 parts (dry weight) of a styrene-maleic anhydride copolymer were mixed, and the glass transition point was adjusted to 60 ° C. It was adjusted. Synthetic silica having an average particle diameter of 7 μm (Carplex 8
OD: 40 parts by Shionogi & Co., Ltd.) to obtain a target pressure-sensitive pseudo-adhesive. The obtained pressure-sensitive adhesive was applied to high quality paper in exactly the same manner as in Example 1 to obtain a pressure-sensitive pseudo-adhesive sheet. With respect to the obtained sheet, the results of evaluating the adhesive strength, printability, NIP suitability, and blocking property are as shown in Table 1.

Comparative Example 2 Synthetic silica (Carplex 80D: Shionogi Pharmaceutical Co., Ltd.) having an average particle size of 7 μm without adding a water-soluble resin emulsion to 100 parts (dry weight) of an acrylate ester (glass transition point is −50 ° C.) as an adhesive base Was mixed with each other to obtain a target pressure-sensitive pseudo-adhesive having a glass transition point of −50 ° C. The resulting pressure-sensitive adhesive was applied to high quality paper in exactly the same manner as in Example 1,
A pseudo pressure-sensitive adhesive sheet was obtained. About the obtained sheet,
Table 1 shows the results of evaluating the adhesive strength, printability, NIP suitability, and blocking property.

Comparative Example 3 As an adhesive base, 100 parts (dry weight) of styrene-maleic anhydride copolymer are mixed with 100 parts (dry weight) of an acrylate ester (glass transition point is −50 ° C.), and a fine particle filler is added. Thus, a desired pressure-sensitive pseudo-adhesive having a desired glass transition point of −50 ° C. was obtained. The obtained pressure-sensitive adhesive composition was applied to high-quality paper in exactly the same manner as in Example 1 to obtain a pseudo pressure-sensitive adhesive sheet. About the obtained sheet, adhesive strength, printability, NIP suitability,
Table 1 shows the results of evaluating the blocking property.

Comparative Example 4 As an adhesive base, styrene-
Aside from replacing 100 parts (dry weight) of the maleic anhydride copolymer with 100 parts (dry weight) of modified natural rubber latex,
A pressure-sensitive adhesive composition was obtained in the same manner as in Example 2. The obtained pressure-sensitive adhesive composition was applied to high-quality paper in exactly the same manner as in Example 1 to obtain a pseudo pressure-sensitive adhesive sheet. Table 1 shows the results of evaluating the adhesive strength, printability, NIP suitability, and blocking property of the obtained sheet.

[0050]

[Table 1]

[0051]

[Brief description of the drawings]

FIG. 1 is a perspective view of a delivery slip according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA ′ of FIG. 1.

[Explanation of symbols]

1 Delivery slip, 2 base materials, 3 pseudo adhesive, 4 delivery section, 5 receiving section, 6 perforations, 7 pressure sensitive pseudo adhesive sheet

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 31, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive, removable pressure-sensitive pseudo-adhesive sheet which can be used for delivery slips, confidential postcards, address labels, etc., and which can clearly read printed or printed information. It is.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009]

The inventors of the present invention have conducted intensive studies and as a result, the above-mentioned objects have been achieved in that the pressure-sensitive adhesive layer comprises at least an acrylic ester (A) and a water-soluble resin emulsion (B). A layer containing an acrylic resin emulsion pressure-sensitive adhesive base as a main component and a fine particle filler as a basic component, and a glass transition point of an acrylate ester in a range of -90 to 50 ° C, and water solubility. glass transition temperature when mixed with the resin emulsion is in the range of -80~20 ℃, characterized in that it is a mixture of a water-soluble resin emulsion is from 5 to 500 parts by weight dispersion with respect to 100 parts by weight of acrylic acid ester Reached by pressure sensitive pseudo adhesive sheet
I found that I can do it .

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

More preferably, the pressure-sensitive adhesive layer of the pressure-sensitive pseudo-adhesive sheet and the adhesive sheet are superimposed and re-peelable and pseudo-adhered to each other at a T-peel strength of 20 ° C.
In measurement based on JISK6833 under an environment of 5% RH, Ru peel strength der above 10 g / 25 mm.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The pressure-sensitive adhesive of the present invention is obtained by mixing an acrylic resin emulsion pressure-sensitive adhesive base containing an acrylate ester and a water-soluble resin emulsion as main components, and preferably fine particles, and mixing the mixture. mixture is contained aid as a basic component, to adjust easily adhesive strength by the Turkish adjusting the glass transition point at the time of dispersing the water-soluble resin emulsion acrylic acid ester in the range of -80～30 ° C. Can be.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

Adhesive force: After the sample was left in an environment of 20 ° C. and 50% RH for 12 hours or more, a mail sealer (MS) was used.
- 9100: Dai Nippon Printing Co., Ltd.) was used to pressure bonding with a roll gap 14 (140 .mu.m), five minutes later T
A mold release test was performed based on JIS K6833.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction contents]

[0050]

[Table 1] ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 26, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Simulated pressure-sensitive adhesive sheet

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive, removable pressure-sensitive pseudo-adhesive sheet which can be used for delivery slips, confidential postcards, address labels, etc., and which can clearly read printed or printed information. It is.

[0002]

2. Description of the Related Art Conventionally, a general delivery slip has a configuration in which a plurality of delivery sections including at least a delivery section and a receiving section are overlapped and stapled, and delivery information is written in a higher-order slip. Then, a copy structure is provided so that the lower-order slip can be copied and entered.

As an information transmitting means having such delivery information, a device using a pressure-sensitive pseudo-adhesive sheet, which is exemplified in Japanese Patent Application No. 8-326355, has been invented and actively used.

[0004] A pressure-sensitive pseudo-adhesive sheet has a so-called non-peelable pressure-sensitive adhesive base such as natural rubber or synthetic rubber and an adhesive force of the pressure-sensitive adhesive base on at least a part of one side of a base sheet. A layer of a pressure-sensitive adhesive composed of a fine particle filler that suppresses odor is provided, and generally has a function of temporarily adhering but easily peeling off when necessary.

The pressure-sensitive adhesive deteriorates with time (hereinafter referred to as aging phenomenon) as represented by yellowing, a decrease in adhesive strength, and curing. Natural rubber, in particular, has a performance change due to the aging phenomenon. Remarkable. Generally, the aging phenomenon of the pressure-sensitive adhesive is mainly caused by oxidation due to contact with atmospheric oxygen and absorption of ultraviolet rays. In addition, the fine particle filler is usually compounded in the pressure-sensitive adhesive layer, but there is a problem that the bonding strength is not stable depending on the amount of the fine particle filler and the dispersion state. Further, the mechanical stability at the time of adjusting the pressure-sensitive adhesive is poor, and there is also a problem in suitability for application to the base sheet. Therefore, conventionally, in a pressure-sensitive pseudo-adhesive sheet, an antioxidant and an ultraviolet absorption inhibitor for preventing oxidation of the pressure-sensitive adhesive are added to the pressure-sensitive adhesive layer.

Further, a tackifier, a surfactant, a thickener, a defoaming agent, a release agent, and the like are added to the same pressure-sensitive adhesive layer in order to improve the applicability of the pressure-sensitive adhesive. There is a disadvantage that the production cost is increased and the advantage of using inexpensive materials is lost.

In recent years, with the rapid increase in demand for communication means requiring such delivery information, it has been required to print information on a high-efficiency and high-quality pressure-sensitive pseudo-adhesive sheet. The method of printing information on the pressure-sensitive pseudo-adhesive sheet has been shifting from printing with an impact printer, which was conventionally used in combination with a computer, to printing using an electrophotographic method or an inkjet recording method with a computer, and toner retransfer. In addition, problems such as ink bleeding have occurred.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a stable pressure-sensitive adhesive force, suppress the stickiness of the pressure-sensitive adhesive applied layer, prevent blocking during processing, and improve printability. It is an object of the present invention to provide a pressure-sensitive pseudo-adhesive sheet having excellent pressure-sensitive pseudo-adhesive performance that is excellent in removability and can be selected from any material to be bonded.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above-mentioned objects are to provide a pressure-sensitive adhesive layer capable of printing or printing information on at least one surface of a support. In the provided pressure-sensitive pseudo-adhesive sheet, the pressure-sensitive adhesive layer includes an acrylic emulsion pressure-sensitive adhesive base containing at least an acrylate (A) and a water-soluble resin emulsion (B) as main components; And the glass transition point of the acrylic acid ester is in the range of −90 to 50 ° C., and the glass transition point when mixed with the water-soluble resin emulsion is −80 to
It is in the range of 20 ° C., and the water-soluble resin emulsion exceeds 50 parts by weight per 100 parts by weight of the acrylate ester.
0 parts by weight or less, the pressure-sensitive adhesive layer of the pressure-sensitive pseudo-adhesive sheet and the adhesive sheet are superimposed and re-peelable and pseudo-adhered at the boundary surface at a T-type peel strength of 20 ° C.
In a measurement based on JIS K6833 in an environment of 65% RH, it was found that the pressure-sensitive pseudo-adhesive sheet was characterized by having a peel strength of 10 g / 25 mm or more.

In the present invention, an acrylic emulsion containing an acrylate ester and a water-soluble resin emulsion as main components is used as a pressure-sensitive adhesive base because a water-soluble resin emulsion formed into a protective colloid is dispersed in an acrylic resin ester. By causing the water-soluble resin to move to the surface of the coating layer in accordance with the evaporation of moisture and the like in the drying step during coating, the water-soluble resin component contains a large amount of the water-soluble resin component. The pressure-sensitive adhesive sheet coated with the pressure-sensitive adhesive of the present invention can prevent blocking or the like from occurring, or the pressure-sensitive adhesive This is for exhibiting the function of preventing the surface from being sticky.

In the present invention, a pseudo-adhesive which can be re-peeled by adding a fine particle filler to a pressure-sensitive adhesive base comprising an acrylic emulsion containing an acrylic ester and a water-soluble resin emulsion as main components. Performance can be more effectively expressed.

[0012] The mechanism is to use an acrylic resin in an emulsion state on the surface of the fine particle filler by using the fine particle filler, and in the drying step,
By developing a configuration in which the pressure-sensitive adhesive component is exposed on the surface of the fine-particle filler, and applying a pressure-sensitive adhesive containing the fine-particle filler with the adhesive component exposed on the surface, the surface of the coating layer becomes finer. Irregularities due to the particle filler are formed, the irregularities shift when a predetermined pressure is applied, the surface of the pressure-sensitive adhesive layer becomes flat, and the bonding surface changes from point bonding due to unevenness to surface bonding and it can be re-peeled Glue.

Although the pseudo-adhesion mechanism in this case is not clear, self-diffusion of polymer resin, dipole force, hydrogen bonding,
Alternatively, it is considered to be due to an adhesion mechanism such as entanglement between the physical polymer resin and the substrate surface.

The fine particle filler used in the present invention is preferably hydrophilic and has an average particle diameter in the range of 1 to 20 μm. When the average particle size is less than 1 μm, the fine particle filler tends to fall off from the pressure-sensitive adhesive applied layer, and when the average particle size is 20 μm or more, the protrusions of the pressure-sensitive adhesive applied surface become remarkable and sufficient feeling is obtained. There is a possibility that adverse effects such as a lack of pressure bonding force may be caused.

The average particle size of the fine particle filler is generally represented by an average value of the size of one particle. For example, fine particles such as silica form a group, and When the particles behave like particles, the particle population (2
(Next particle).

The compounding ratio of the water-soluble resin emulsion to be dispersed in the acrylate used in the present invention is preferably such that 5-500 parts by weight of the water-soluble resin emulsion is dispersed with respect to 100 parts by weight of the acrylate. . If the compounding ratio is less than 5 parts by weight or 500 parts by weight or more, there is a possibility of causing problems such as occurrence of blocking or insufficient expression of adhesive strength. More preferably, a water-soluble resin emulsion is dispersed in an amount of 5 to 200 parts by weight with respect to 100 parts by weight of an acrylate ester.

Therefore, in the present invention, at least 5
It is preferred that about 500 parts by weight of the water-soluble resin emulsion is dispersed in the acrylate. More preferably, the glass transition point is −
The glass transition point when the acrylate in the range of 90 to 50 ° C. is mixed with the water-soluble resin emulsion is −
It is preferably in the range of 80 to 20 ° C.

The mixing ratio of the pressure-sensitive adhesive and the fine particle filler used in the present invention is 100
It is preferable that the fine particle filler is contained in an amount of 5 to 200 parts by weight based on parts by weight. If the compounding ratio is less than 5 parts by weight, printing or printability is insufficient, or 2
When the amount is more than 00 parts by weight, there is a possibility that the fine particle filler may be easily peeled off from the applied layer of the pressure-sensitive adhesive, or may cause adverse effects such as insufficient adhesive strength.

Therefore, in the present invention, at least 5
It is preferred to use the fine particle filler in the pressure-sensitive adhesive in an amount of up to 200 parts by weight.

The fine particle filler used in the pressure-sensitive adhesive of the present invention includes silica, charcoal, kaolin, clay, talc, aluminum hydroxide, titanium oxide, zinc oxide, activated clay, starch particles, cellulose particles, styrene. It can be appropriately selected and used from inorganic or organic known fine particle fillers such as resin particles, acrylic resin particles, urea resin particles, microcapsules, oil capsules, polyethylene, and vinyl chloride. I can do it. These fine particle fillers may be used alone or in combination of two or more.

When two or more kinds are used in combination, irregularities due to the fine particle filler on the pressure-sensitive adhesive applied surface can be made discontinuous, and the pressure-sensitive adhesive property can be easily adjusted.

In the present invention, it is preferred that a hydrophilic, more preferably non-thermoplastic, fine particle filler is contained in the acrylic emulsion.

The water-soluble resin emulsion to be dispersed in the acrylate used in the acrylic emulsion of the present invention includes polyvinyl alcohol, carboxymethyl cellulose, polyvinyl pyrrolidone, polyacrylic acid,
From among known water-soluble polymers such as polyacrylamide, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, etc. Can be appropriately selected and used.

These resins may be used alone or
More than one type may be used in combination. By using two or more types of water-soluble resins, it becomes easy to adjust the glass transition point in the range of −80 to 20 ° C. when the acrylate and the water-soluble resin emulsion are mixed.

In the present invention, UV resistance, printability,
It is most preferable to use a styrene-maleic anhydride copolymer excellent in blocking resistance and the like for stabilizing quality.

The pressure-sensitive adhesive may further include a surfactant, an antifoaming agent, a thickener, a water-proofing agent, a dispersant, an ultraviolet absorber, an antioxidant, an antistatic agent, and an ink fixing agent, if necessary. Auxiliary agents such as a dye fixing agent, a fluorescent dye, a colored dye, a lubricant, a deodorant, a deodorant, and an antibacterial agent can also be added.

The pressure-sensitive adhesive property of the pressure-sensitive adhesive layer according to the present invention is such that the T-peel strength at the boundary where the pressure-sensitive adhesive layer and the sheet to be bonded are superimposed and re-peelable is 300.
mm / min, JIS under the environment of 20 ° C and 65% RH
When measured based on K6833, the peel strength is preferably 10 g / 25 mm or more, particularly preferably 20 to 120 g / 25 mm. When the T-type peel strength is 10 g / 25 mm or less, spontaneous peeling may occur and 120 g / 25 mm In the above case, the printed or printed information may be damaged at the time of re-peeling, or peeling may not be possible.

It is difficult to adjust the re-peeling strength only by the mixing ratio of the water-soluble resin emulsion to be dispersed in the acrylate, the mixing ratio of the fine particles, and the addition of the auxiliary. The combination ratio of the water-soluble resin emulsion to be dispersed, the combination ratio of the fine particles, and the addition of an auxiliary are combined, and the glass transition point when the water-soluble resin emulsion is dispersed in the acrylate is in the range of -80 to 30 ° C. It becomes easy by adjusting to. By the way, when the glass transition point is out of this range, the stability with time is inferior, and the stress absorption under pressure is greatly reduced, so that it may be difficult to achieve both peelability and adhesiveness.

As the base material used in the present invention, for example, high quality paper, medium quality paper, recycled paper, art paper, coated paper, lightly coated paper, synthetic paper, film, laminated paper, metallized paper and the like are used. I can do it.

In the present invention, the pressure-sensitive adhesive is applied to the substrate by using a conventionally known coating machine or printing machine such as a blade coater, an air knife coater, a bar coater, a roll coater, a gravure printing machine or a screen printing machine. Can be used.

In the present invention, the amount of the pressure-sensitive adhesive to be applied to the substrate is usually preferably about ² to ²⁰ g / m ^{2 in} order to develop an appropriate adhesive force.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION The pressure-sensitive adhesive of the present invention is obtained by mixing an acrylic emulsion pressure-sensitive adhesive base containing an acrylic ester and a water-soluble resin emulsion as main components, and preferably fine particles, and mixing the mixture. Adhesive force can be easily adjusted by adjusting the glass transition point when the water-soluble resin emulsion is dispersed in the acrylate ester in the range of −80 to 30 ° C. by mixing and containing an auxiliary as a basic component. .

After the pressure-sensitive adhesive of the present invention is applied to a predetermined portion of the base material and dried, the portion to which the pressure-sensitive adhesive is applied and the portion to be bonded are opposed to each other, and a predetermined pressure is applied to the pseudo-adhesive. Can be glued. Further, since the surface of the coating layer of the pressure-sensitive pseudo-adhesive has good information recording suitability such as printing and printing, it becomes a pressure-sensitive pseudo-adhesive sheet on which information can be recorded.

[0034]

The pressure-sensitive pseudo-adhesive sheet of the present invention has a stable adhesive force and suppresses the stickiness of the surface of the adhesive layer, so that it does not cause blocking or the like, and has excellent printability. Since the material to be bonded is not selected, the range of selection of the material to be bonded is increased and the range of application is expanded. Furthermore, the pressure-sensitive pseudo-adhesive sheet of the present invention is a thermal paper,
Inkjet paper, thermal transfer paper, no-carbon paper,
It can be used as coated paper, high-quality paper, or the like, or can be combined with these papers, or can be coated with an adhesive or the like on the back surface, and can be used in combination with various base materials.

[0035]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Unless otherwise specified, “parts” and “%” described below mean “parts by weight” and “% by weight”, respectively.

Embodiment 1 100 parts (dry weight) of an acrylate ester (glass transition point is -50 ° C.) as an adhesive base and 100 parts (dry weight) of a styrene-maleic anhydride copolymer were mixed, and the glass transition point was -30 ° C. Was adjusted. 50 parts of synthetic silica having an average particle diameter of 7 μm (Carplex 80D: manufactured by Shionogi & Co., Ltd.) are mixed,
The desired pressure-sensitive pseudo-adhesive was obtained.

Next, this pressure-sensitive adhesive composition was prepared using 127.
9 g / m ² of high-quality paper was applied so that the application amount was 10 g / m ² (dry weight) to obtain a pressure-sensitive pseudo-adhesive sheet.
Using this sheet, adhesive strength, printability,
Table 1 shows the results of evaluating non-impact printing suitability (hereinafter referred to as NIP suitability) and blocking property.

Adhesive force: After the sample was left in an environment of 20 ° C. and 50% RH for 12 hours or more, a mail sealer (MS) was used.
-9100: manufactured by Dai Nippon Printing Co., Ltd.) under pressure with a roll gap of 14 (140 μm).
A mold release test was performed based on JIS K6833.

UV deterioration test: The sample was forcibly irradiated with ultraviolet light for a predetermined time using a UV irradiator, and was irradiated at 20 ° C. and 50% R.
After being left in an environment of H for 12 hours or more, evaluation was performed in the same manner as in the case of the adhesive strength.

Printing suitability test: Using an offset printing machine, ink bleeding and image reproducibility when printed on the adhesive layer of the pseudo-adhesive sheet were visually observed and evaluated.・ Those with good image reproducibility → ○ ・ Those with poor image reproducibility → ×

Non-impact printing suitability test:
Using a non-impact printer (F-6762D: manufactured by Fujitsu Ltd.), the transferability of the image and the like were visually observed and evaluated.・ Those with good image reproducibility and running performance without blurring etc. →
○ ・ Image reproducibility is not a problem, but runnability is poor → △ ・ Image reproducibility and runnability are poor, and faintness and dirt are generated → ×

Blocking evaluation test: Evaluation was made by stacking 50 samples, applying a predetermined load in an environment of 20 ° C. and 65% RH, leaving them standing, and removing them by hand 24 hours later.・ No blocking etc. → ○ ・ Some blocking occurs but can be easily removed by hand → △ ・ Blocking → ×

Embodiment 2 FIG. As an adhesive base, 100 parts (dry weight) of an acrylate ester (glass transition point is −50 ° C.) and 100 parts (dry weight) of an ethylene-maleic anhydride copolymer are mixed, and the glass transition point is −30 ° C. Was adjusted. 40 parts of synthetic silica having an average particle diameter of 7 μm (Carplex 80D: manufactured by Shionogi & Co., Ltd.) are mixed,
The desired pressure-sensitive pseudo-adhesive was obtained. The obtained pressure-sensitive adhesive was applied to high quality paper in exactly the same manner as in Example 1 to obtain a pressure-sensitive pseudo-adhesive sheet. For the obtained sheet, the adhesive strength,
Table 1 shows the results of evaluating printability, NIP suitability, and blocking properties.

Comparative Example 1 100 parts (dry weight) of an acrylate (glass transition point is −50 ° C.) as an adhesive base and 300 parts (dry weight) of a styrene-maleic anhydride copolymer were mixed, and the glass transition point was adjusted to 60 ° C. It was adjusted. Synthetic silica having an average particle diameter of 7 μm (Carplex 8
OD: 40 parts by Shionogi & Co., Ltd.) to obtain a target pressure-sensitive pseudo-adhesive. The obtained pressure-sensitive adhesive was applied to high quality paper in exactly the same manner as in Example 1 to obtain a pressure-sensitive pseudo-adhesive sheet. With respect to the obtained sheet, the results of evaluating the adhesive strength, printability, NIP suitability, and blocking property are as shown in Table 1.

Comparative Example 2 Synthetic silica (Carplex 80D: Shionogi Pharmaceutical Co., Ltd.) having an average particle size of 7 μm without adding a water-soluble resin emulsion to 100 parts (dry weight) of an acrylate ester (glass transition point is −50 ° C.) as an adhesive base Was mixed with each other to obtain a target pressure-sensitive pseudo-adhesive having a glass transition point of −50 ° C. The resulting pressure-sensitive adhesive was applied to high quality paper in exactly the same manner as in Example 1,
A pseudo pressure-sensitive adhesive sheet was obtained. About the obtained sheet,
Table 1 shows the results of evaluating the adhesive strength, printability, NIP suitability, and blocking property.

Comparative Example 3 As an adhesive base, 100 parts (dry weight) of styrene-maleic anhydride copolymer are mixed with 100 parts (dry weight) of an acrylate ester (glass transition point is −50 ° C.), and a fine particle filler is added. Thus, a desired pressure-sensitive pseudo-adhesive having a desired glass transition point of −50 ° C. was obtained. The obtained pressure-sensitive adhesive composition was applied to high-quality paper in exactly the same manner as in Example 1 to obtain a pseudo pressure-sensitive adhesive sheet. About the obtained sheet, adhesive strength, printability, NIP suitability,
Table 1 shows the results of evaluating the blocking property.

Comparative Example 4 As an adhesive base, styrene-
Aside from replacing 100 parts (dry weight) of the maleic anhydride copolymer with 100 parts (dry weight) of modified natural rubber latex,
A pressure-sensitive adhesive composition was obtained in the same manner as in Example 2. The obtained pressure-sensitive adhesive composition was applied to high-quality paper in exactly the same manner as in Example 1 to obtain a pseudo pressure-sensitive adhesive sheet. Table 1 shows the results of evaluating the adhesive strength, printability, NIP suitability, and blocking property of the obtained sheet.

[0048]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a perspective view of a delivery slip according to one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA ′ of FIG.

[Description of Signs] 1 Delivery slip, 2 base material, 3 pseudo adhesive, 4 delivery section, 5 receiving section, 6 perforations, 7 pressure sensitive pseudo adhesive sheet.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Takechi 5-1 Kamiyacho, Iyo Mishima City, Ehime Prefecture Daio Paper Co., Ltd.

Claims (2)

[Claims] 1. A pressure-sensitive pseudo-adhesive sheet provided with a pressure-sensitive adhesive layer on which information can be printed or printed on at least one surface of a support, wherein the pressure-sensitive adhesive layer has at least an acrylic ester (A). And a layer containing an acrylic resin emulsion pressure-sensitive adhesive base containing a water-soluble resin emulsion (B) as a main component and a fine particle filler as a basic component. It is in the range of 50 ° C., the glass transition point when mixed with the water-soluble resin emulsion is in the range of −80 to 20 ° C., and the water-soluble resin emulsion is dispersed in an amount of 5 to 500 parts by weight per 100 parts by weight of the acrylate ester. A pressure-sensitive pseudo-adhesive sheet comprising: 2. An environment in which the pressure-sensitive adhesive layer of the pressure-sensitive pseudo-adhesive sheet and the adhesive sheet are superimposed and re-peelable and pseudo-adhered to each other have a T-peel strength of 20 ° C. and 65% RH. 10 g / 25 as measured according to JIS K6833.
The pressure-sensitive pseudo-adhesive sheet according to claim 1, having a peel strength of not less than mm.