JPH0867857A - Pressure-sensitive adhesive sheet for adherend made of abs resin - Google Patents

Abstract

PURPOSE: To obtain a recyclable pressure-sensitive adhesive sheet by forming an ABS resin into a film, using the resultant substrate film having a thickness within a specific range and further forming a release sheet, a pressure-sensitive adhesive layer and the substrate film in this order. CONSTITUTION: This recyclable pressure-sensitive adhesive sheet is obtained by forming layers of a release sheet 1, a pressure-sensitive adhesive layer 2 and a substrate film 3 prepared from an ABS resin in this order and applying the resultant layers to an adherend made of the ABS resin in a state integral with the adherend. The substrate film 3 has 15-150μm thickness. A color pigment is contained in an amount of 2-60 pts.wt. based on 100 pts.wt. substrate film 3 and preferably colored. The substrate film 3 is preferably transparent and a colored layer 7 having masking properties is preferably formed on the whole outer surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive sheet for an adherend made of acrylonitrile butadiene styrene resin (hereinafter referred to as ABS resin).

[0002]

2. Description of the Related Art A pressure-sensitive adhesive sheet having a printed layer formed on one surface of a substrate made of paper or a resin film and a pressure-sensitive adhesive layer formed on the other surface is coated with a pressure-sensitive adhesive sheet after peeled from a release sheet. It is attached to a kimono and used as a price tag, label, sticker, etc.

Paper is widely used as a base material in this type of pressure-sensitive adhesive sheet because it is inexpensive, but a resin film is often used as the base material. As far as the pressure-sensitive adhesive sheet is concerned, the resin film is generally made of a resin such as polyester resin, vinyl chloride resin, polypropylene resin or the like and formed into a film of about 20 to 125 μm.

Polyester resin is mainly used because it is possible to obtain a thin and tough film or a thick and elastic film, and vinyl chloride resin is inexpensive and has a plasticizer, an additive and a stable property. It is used because it can form a soft to hard film by selecting the type and amount of the agent.

[0005]

By the way, ABS resin has excellent impact resistance, electrical properties, chemical resistance, and oil resistance, and also has excellent processing characteristics, such as injection molding, extrusion molding, and vacuum molding. Any molding method such as molding can be adopted, and the molded product has excellent properties such as dimensional stability, creep resistance, and stress cracking resistance. Therefore, ABS resin is molded by injection molding in electrical parts such as electric appliances, refrigerators, vacuum cleaners, vehicle parts such as instrument panels, door panels and armrests, and in the fields of stationery, household goods, sports goods, etc. It is applied as a plate or sheet extruded into a product or plate.

On the other hand, recycling of plastic products has been strongly desired under the environmental problems that have become serious in recent years. ABS resin is the most suitable plastic for this recycling.

However, when a pressure-sensitive adhesive sheet having the above-mentioned resin, for example, a polyester resin as a base film, is attached to a product or part made of ABS resin, the product or part made of ABS resin is recycled at the time of recycling. In order to separate the pressure-sensitive adhesive sheet, it is necessary to peel it off manually. With this, the efficiency of recycling is extremely deteriorated.

[0008] Therefore, the main problem of the present invention is AB
An object of the present invention is to provide a pressure-sensitive adhesive sheet that can be recycled together with an adherend made of S resin.

[0009]

[Means for Solving the Problems] The above problem is a pressure-sensitive adhesive sheet having a release sheet, a pressure-sensitive adhesive layer, and a base film in this order, wherein the base film is made of acrylonitrile butadiene styrene resin. The thickness of the base film is 15 to 150 μm.
m, which is attached to an ABS resin adherend and
This can be solved by being recyclable together with the S resin adherend.

In this case, in consideration of printability, a coloring pigment may be contained in the base film, or when the base film is transparent, a colored layer having a hiding property may be formed on the entire outer surface thereof. it can.

Here, the term "recycling" means that when the pressure-sensitive adhesive sheet, especially the equipment to which the adhesive label is attached, becomes old and is discarded, the ABS resin portion to which the adhesive label is attached is collected and reused again. The main purpose is to supply the ABS resin part together with the adhesive label to the molding machine to make it a new device product part.

[0012]

In the past, there was no idea to recycle the pressure-sensitive adhesive sheet together with the adherend. In the present invention, the adherend is AB
Targets are made of S resin. ABS resin is a recyclable plastic. In the present invention, ABS resin is used as the base material of the pressure-sensitive adhesive sheet. As a result, the pressure-sensitive adhesive sheet can be recycled with the pressure-sensitive adhesive sheet adhered to the adherend without any foreign matter mixed in or substantially without any trouble.

Although the ABS resin is excellent in moldability as described above, there is no idea that it is used as a base material of a pressure-sensitive adhesive sheet for printing, as compared with polyester and the like. Slightly for painting on ABS resin molded products,
There is an example in which a sheet having a thickness of 0.2 to 0.4 mm is used as a curved surface thermal transfer sheet.

However, the present inventors can obtain an ABS film having a thickness of 15 to 150 μm by adopting the calendering method, the casting method or the T-die method, and the pressure-sensitive adhesive sheet using this as a base material. (1) printability (any printing method such as screen printing, sticker printing, offset printing can be applied,
There is no cissing, chattering, blanking, see-through, curl, or shrinkage caused by printing ink. Adhesion (no cracking or peeling),
(5) Adhesive force, (6) Holding force, (7) Ball tack,
It was found that (8) labelability (good handleability, no wrinkles, no tears) and (9) excellent weather resistance.

A pressure-sensitive adhesive sheet for printing having a concealing property can be prepared as follows. When the base film contains 2 to 60 parts by weight of a pigment as a coloring material, the hiding property of the film can be obtained. As the pigment, a desired color can be obtained by kneading a general coloring pigment into the film material in addition to titanium white which is a white pigment and carbon black which is a black pigment. When the substrate film is transparent, a printing ink is printed on the entire surface or a colored layer is coated on the entire surface to provide a colored layer having a concealing property.

[0016]

The present invention will be described in more detail below. In the present invention, the adherend is a product or part made of ABS resin. As the base material, a film of ABS resin having a thickness of 15 to 150 μm, particularly 35 to 80 μm is preferably used. When the thickness is thin, the sticking workability is deteriorated and it is difficult to obtain a film having a uniform thickness.
On the other hand, if it is thick, it becomes easy to peel off and the conformability to the adherend becomes poor.

The base film having a thickness of 15 to 150 μm can be manufactured by the T-die extrusion method, the calender method or the casting method. In this case, in the T-die extrusion method and the calender method, after selecting physical properties such as hardness, tensile strength and elongation of the target product film, a composition having fluidity suitable for film processing within a range where the physical properties are obtained. Is selected. When the T-die extrusion method or the calender method is used, the film thickness is preferably 40 to 150 μm. Among these methods, the casting method is costly, but is suitable for obtaining a thin film having a thickness of 15 to 50 μm, and it is easy to control the thickness, flexibility, hardness, etc., and the T die extrusion method is used. Excellent in processability during film forming compared to the calendar method. However, the calender method is most suitable for obtaining a slightly thick film.

A pressure sensitive adhesive is applied to the base film. In this case, it is preferable to apply the pressure-sensitive adhesive to a release sheet, for example, release paper having a release treatment such as silicone, and to bond the release sheet, for example, release paper, to the base film, rather than directly applying the pressure-sensitive adhesive.

As the pressure sensitive adhesive used in the present invention, it is desirable to use an acrylic or rubber adhesive. As the acrylic pressure-sensitive adhesive, it is possible to use an acrylic acid ester having an acrylic group having 4 to 12 carbon atoms, acrylic acid, methacrylic acid-based adhesive, or the like. As the rubber pressure-sensitive adhesive, natural rubber, isoprene rubber, styrene / butadiene rubber, styrene / butadiene block copolymer, styrene / isoprene block copolymer system or the like can be used.

In particular, since the pressure-sensitive adhesive sheet of the present invention is optimally used as a label by punching after printing, in consideration of punching characteristics for labeling, a rubber-based pressure-sensitive adhesive is used. The acrylic adhesive is most suitable depending on the agent.

The preferred thickness of the pressure sensitive adhesive is from 10 to 10.
It is 50 μm, more preferably 20 to 35 μm. 35
If it is less than μm, there is almost no problem in terms of recyclability.

As this acrylic pressure-sensitive adhesive, use should be made of an acrylic pressure-sensitive adhesive mainly containing an alkyl acrylate having 4 to 12 carbon atoms and 5 to 40 parts by weight of a tackifier added thereto. You can Among the tackifiers, a styrenated hydrocarbon resin and a styrenated terpene resin having a composition similar to ABS are preferable.

As for the rubber-based pressure-sensitive adhesive, a styrene-butadiene-styrene copolymer or a styrene-isoprene-styrene copolymer is preferably used as a main component, and a tackifier is a styrenated hydrocarbon resin, Styrenated terpene resins and the like are preferred.

A vapor-deposited layer of aluminum or the like can be provided on both sides or one side of the base film. A printing layer such as characters, marks, and patterns is formed on the base film by a usual printing method such as screen printing, gravure printing, offset printing, and sticker printing. The vehicle of the printing ink forming the printing layer is preferably a non-curable type. Since the pigment in the printing ink is also contained in the adherend, the type of pigment does not affect recyclability. In order to protect this printed layer, a transparent or translucent laminating material having a transparent or translucent adhesive layer may be provided. In this case, the laminate material is made of ABS resin like the base film, and the rubber-based or acrylic pressure-sensitive adhesive composition is used like the pressure-sensitive adhesive for the base film.

[0025]

The present invention will be described in more detail by way of examples with reference to the drawings.

FIG. 1 shows a pressure-sensitive adhesive sheet SA according to the present invention.
It is sectional drawing which shows the 1st example of. The pressure-sensitive adhesive layer 2 is formed on the release-treated surface of the release paper 1, and AB is further formed on the pressure-sensitive adhesive layer 2.
A colored substrate film 3 made of S resin is provided. On the upper side of the base film 3, a printed layer 4 representing a design or the like is formed.

FIG. 2 shows a pressure-sensitive adhesive sheet SB of the second example, in which the printing layer 4 is covered with a transparent pressure-sensitive adhesive layer 5 and a laminate material 6 made of a transparent ABS resin.

In these examples, the base film 3 can be colored by adding 2 to 60 parts by weight of a coloring pigment to 100 parts by weight of the base film material.

Further, FIG. 3 shows a third pressure-sensitive adhesive sheet S.
FIG. 3C shows the transparent base film 3, on which the concealing colored layer 7 is formed.

(Experimental Example) The effect of the present invention will be described in more detail with reference to an experimental example. In this experiment, ABS is used as a comparative example.
The physical properties of the resin molded product was measured, and this was used as a blank value.On the other hand, the physical property value when the label of each Example was attached to this molded product was examined, and this physical property value was compared with the blank value,
It is determined whether or not recyclable.

(Comparative Example) "GR-1" manufactured by Denki Kagaku Kogyo Co., Ltd.
1 kg of "500 (pellet)" was prepared and molded into a shape of dumbbell, bar, plate or the like with an injection molding machine, and then the physical properties were measured based on the following test methods.

JIS K 7110 (Izod impact strength) JIS K 7112 (specific gravity) JIS K 7113 (tensile strength) JIS K 7202 (Rockwell hardness) JIS K 7203 (bending strength) JIS K 7203 (bending elastic modulus) JIS K 7207 (Weighted Deflection Temperature) JIS K 7210 (Melt Flow Rate) Further, the appearance of the molded product was observed to examine whether or not there is an appearance abnormality such as streaks, unevenness, and scratched skin.

(Example 1) "ABS10" manufactured by Japan Synthetic Rubber Co., Ltd. 70 parts "ABS38" manufactured by Japan Synthetic Rubber Co., Ltd. 30 parts Titanium White 20 parts (as a colorant) "Irganox 1010" manufactured by Ciba Geigy Co., Ltd. 0.5
Parts (as antioxidants and stabilizers) calcium stearate 0.5 parts epoxidized soybean oil 0.5 parts A 100 μm thick A of the above composition by calendering
It was a BS film.

Next, an acrylic pressure-sensitive adhesive was applied to the release paper so as to have a thickness of 25 μm after drying, and the release paper was attached to the above film. Further, a polycarbonate ink and an ABS ink were screen-printed on the film surface, dried and punched into a size of 15 cm × 15 cm to prepare a sample. There were no problems during printing, drying and blanking, and the physical properties of the pressure-sensitive adhesive label were good as shown in Table 1 below.

[0035]

[Table 1]

1 g of this label sample excluding release paper
It was weighed out, crushed into pieces of about 2 mm square, and then mixed with 1 kg of a product name "GR-1500" manufactured by Denki Kagaku Kogyo Co., Ltd. Sample preparation and physical property measurement were performed in the same manner as in the comparative example.

Incidentally, 1 g of this label sample has a specific gravity
It is a label piece with a size of 1.053 and a thickness of 135μ and a size of about 7 cm x 10 cm. ABS 1 kg has a specific gravity of 1.046, and if the thickness of the molded product is 2 mm, it is about 70 cm x 70 cm. It can be said that the size of the label attached to the product is standard (general).

(Example 2) The sample prepared in Example 1 was weighed in an amount of 7 g excluding the release paper, crushed into pieces of about 2 mm square, and mixed with 1 kg of the product name "GR-1500" manufactured by Denki Kagaku Kogyo Co., Ltd. did. Sample preparation and physical property measurement were performed in the same manner as in the comparative example. Table 2 shows the results.

Incidentally, 1 g of this label sample has a specific gravity
Since it is a label piece with a size of 1.053 and a thickness of 135μ and a size of about 25 cm x 20 cm, ABS 1 kg has a specific gravity of 1.046, and if the thickness of the molded product is 2 mm, it is about 70 cm x 70 cm. It can be said that this is the largest label to be attached to an item.

[0040]

[Table 2]

From the above evaluation results, it was found that the ABS molded product to which the product of the present invention was adhered was almost the same as the blank value and did not affect the physical properties, and therefore could be sufficiently used for recycling.

[0042]

As described above, according to the present invention, the ABS
It is possible to suitably obtain a pressure-sensitive adhesive sheet that can be recycled together with an adherend made of a resin, particularly an adhesive label.

[Brief description of drawings]

FIG. 1 is a sectional view of a first example of a pressure-sensitive adhesive sheet according to the present invention.

FIG. 2 is a sectional view of the second example.

FIG. 3 is a sectional view of the third example.

[Explanation of symbols]

1 ... Release paper, 2, ... Pressure-sensitive adhesive layer, 3, ... Base film, 4 ... Printing layer, 5 ... Transparent adhesive layer, 6 ... Laminating material, 7 ... Colored layer.

Front Page Continuation (72) Inventor Tatsuo Takeuchi 3-7-4 Higashiikebukuro, Toshima-ku, Tokyo Stock Company Kuramoto Sangyo

Claims (3)

[Claims] 1. A pressure-sensitive adhesive sheet having a release sheet, a pressure-sensitive adhesive layer, and a base film in this order, wherein the base film is a film of acrylonitrile butadiene styrene resin, and the base The film has a thickness of 15 to 150 μm, and can be attached to an ABS resin adherend and recycled together with the ABS resin adherend. Pressure-bonded sheet. 2. The ABS resin pressure-sensitive adhesive sheet for an adherend according to claim 1, wherein the coloring pigment is contained in an amount of 2 to 60 parts by weight based on 100 parts by weight of the base film. 3. The ABS according to claim 1, wherein the base film is transparent and a colored layer having a hiding property is formed on the entire outer surface of the base film.
Pressure-sensitive adhesive sheet for resin adherends.