JPH069931A - Self-adhesive polystyrene tape - Google Patents

Abstract

PURPOSE:To obtain the title tape which is excellent in releasability of the self-adhesive side from the back side of the tape and does not require release paper to be stuck to the back side. CONSTITUTION:The tape comprises a polystyrene sheet substrate, a self-adhesive layer formed on one side of the substrate, and a release layer which does not adhere to the self-adhesive layer and is formed on the other side by applying an org.-solvent soln. of a reactive resin which cures at 20-120 deg.C. Before applying the soln., a primer layer is formed on the same side of the substrate by applying a coating material or ink contg. a vehicle mainly comprising an acrylic resin, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polystyrene pressure-sensitive adhesive tape, more specifically, a release paper is not attached, and
The present invention relates to a polystyrene pressure-sensitive adhesive tape having good peelability between the pressure-sensitive adhesive surface of the pressure-sensitive adhesive tape and the back surface of the tape substrate.

[0002]

2. Description of the Related Art Conventionally, various types of adhesive tapes for packaging have been put to practical use. For example, paper, woven cloth, polypropylene-based sheet, polyvinyl chloride sheet or the like as a tape substrate having an adhesive on one side and a release layer not adhered to the adhesive on the other side, or weak strength As the plastic film base material, a release paper or the like is used.

[0003]

In recent years, such paper,
BACKGROUND OF THE INVENTION Adhesive tapes such as cloth or plastic are often used for fixing styrofoam packaging containers, for example, styrofoam packaging cases such as fish containers, electrical product packaging containers, and automobile parts packing cases. On the other hand, recently, due to the problem of energy saving, there has been an increasing tendency to recover used polystyrene foam and packing materials to regenerate polystyrene pellets. However, the Styrofoam material to which the adhesive tape such as paper, cloth or polypropylene is adhered is mixed with the adhesive tape as a foreign substance when it is melt-reproduced as it is.Therefore, the adhesive tape must be peeled off before it is regenerated. It took a lot of effort and it didn't pay off. Therefore, development of an adhesive tape based on a polystyrene sheet has been attempted. However, in the case of a polystyrene adhesive tape using a polystyrene sheet base material, the tape is liable to break during use unless the back surface is peeled off, so the release paper has to be used as a backup. However, in the adhesive tape that backs up the release paper, a large amount of the release paper remains after the use of the adhesive tape, and the processing of the release paper is very troublesome at the packing site where a large amount of the adhesive tape is used. For this reason, attempts have been made to develop a polystyrene adhesive tape that does not use release paper as a backup (for example, JP-A-50-26840 and JP-A-3-1316).
77 publication). On the other hand, the applicant has already applied for a patent for a polystyrene adhesive tape that does not use release paper. For polystyrene adhesive tape that does not use release paper, it is necessary to apply a treatment with a backside release agent to the polystyrene surface.
Silicon-based resin is generally used as a release agent for this purpose. In this way, in the polystyrene adhesive tape that has been subjected to the back surface treatment with the silicon-based resin, the one using the organic solvent-based acrylic adhesive that does not erode, nitrate, or swell the polystyrene sheet base material is sufficiently smooth to peel off the back surface. This was not done, and there was a problem in terms of workability. As a result of intensive studies to eliminate the above defects, the present inventors have found that when forming a release layer on the surface of a polystyrene sheet, a primer layer is provided on the surface of the polystyrene sheet in advance, and a release layer is further provided thereon. As a result, they have found that the back surface of the tape can be peeled off very easily, and completed the present invention.

[0004]

That is, the present invention provides a polystyrene pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on one surface of a polystyrene-based sheet substrate and a release layer that does not adhere to the pressure-sensitive adhesive layer on the other surface. In the above, a primer layer is provided between the polystyrene-based sheet base material and the release layer, and an organic solvent solution of a reactive resin that cures at 20 to 120 ° C. is used as the release layer-forming coating agent. And a polystyrene adhesive tape. Hereinafter, the present invention will be described in more detail. Examples of the polystyrene-based sheet base material used in the present invention include an unfoamed polystyrene sheet, a foamed polystyrene sheet, and a multilayer polystyrene sheet composed of an unfoamed polystyrene sheet and a foamed polystyrene sheet. The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer in the present invention may be any as long as it is usually used when manufacturing a pressure-sensitive adhesive tape, for example, acrylic pressure-sensitive adhesive, polyurethane pressure-sensitive adhesive, natural rubber or Examples thereof include synthetic rubber adhesives.

Next, in the present invention, a primer layer is provided on the surface of the polystyrene type sheet substrate before forming the release layer. The primer layer may be, for example, an acrylic resin, a polyurethane resin, a polyamide resin or a polyester resin. resin,
It is formed by a paint or ink containing a vinyl chloride-vinyl acetate copolymer resin, a cellulose resin or the like as a vehicle constituent material. When preparing the above paint or ink, it is preferable to use a solvent that does not dissolve or swell the styrene sheet substrate. For that purpose, alcoholic solvents such as methanol, ethanol, isopropanol and butanol are mainly used, and ethyl acetate, butyl acetate,
A mixed solvent obtained by mixing organic solvents such as acetone, cyclohexanone, toluene, xylene, and normal propyl acetate is used.

The reactive resin used as the release layer-forming coating agent in the present invention which cures at 20 to 120 ° C. is, for example, polyurethane resin, polyurea resin, polyurethane polyurea resin, acrylic resin, silicone resin, olefin. And acrylic monomers, partial saponification products of polyvinyl acetate, saponification products of copolymers of vinyl acetate and other monomers, epoxy resins, polyamide resins, polyester resins, cellulosic resins, etc. Reactive resins can also be used. Preferred as the organic solvent used for dissolving or dispersing the above-mentioned reactive resin are methyl ethyl ketone and methyl-n.
-Propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, butyl acetate, etc., and also acetone, cyclohexane, tetrahydrofuran, dioxane, methanol, ethanol, isopropyl alcohol, butanol. , Toluene, xylene, dimethylformamide, dimethylsulfoxide, perchlorethylene,
Trichloroethylene, methyl cellosolve, butyl cellosolve, cellosolve acetate and the like can also be used. Of course, the above organic solvents can be used as a mixed organic solvent.

In the present invention, in order to prevent the primer layer and the polystyrene-based sheet substrate from being dissolved or deteriorated by the above organic solvent, a volatile organic solvent among the above organic solvents is mainly used. Is preferred. The reactive resin in the organic solvent has a solid content of 10 to 6
It is prepared to be 0% by weight. The release layer-forming coating agent can be used as it is, and various known additives such as coloring agents, crosslinking agents, stabilizers, and fillers can be optionally added.

[0008]

The polystyrene-based pressure-sensitive adhesive tape of the present invention is provided on the primer layer because a primer layer that does not deteriorate the polystyrene-based sheet substrate is provided between the polystyrene-based sheet substrate and the release layer. The releasing layer that is formed is hardly adsorbed in the polystyrene-based sheet base material and can maintain a sufficient peeling force.

[0009]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. Example 1 175 L 4 of a coating agent for forming a primer layer having the following composition on one surface of an unexpanded polystyrene sheet having a thickness of 40 μm
Coating is performed using a 0 μ gravure roll plate and dried at 50 ° C. for 5 seconds to form a primer layer. [Coating agent composition for forming primer layer] Acrylic resin (trade name; Acryloid B-66, product of Rohm & Haas) 15 parts by weight Cellulose resin (trade name: CAB-381, product of Eastman Kodak Company) 2 parts by weight Isopropyl alcohol 45 parts by weight Ethyl acetate 12 parts by weight Normal propyl acetate 26 parts by weight Next, a silicone resin (trade name; K) on the primer layer.
S-841, product of Shin-Etsu Chemical Co., Ltd.) 175 L 40, a coating agent for forming a release layer consisting of 30 parts by weight, platinum catalyst 2.5 parts by weight and methyl ethyl ketone 67.5 parts by weight.
coated with μ gravure roll plate, 110
The coating film is cured at 15 ° C. for 15 seconds to form a release layer. Then, an acrylic resin pressure-sensitive adhesive (trade name; E-3303S manufactured by Soken Chemical Co., Ltd.) was applied to the other surface of the unfoamed polystyrene sheet by a roll coater so that the coating film after drying was 35 g / m ^2, and 50 After drying at ℃ for 15 seconds, it was wound and slit into a width of 50 mm to obtain a polystyrene adhesive tape. The physical properties of the obtained tape are shown in Table 1.

Example 2 A coating agent for forming a primer layer having the following composition was formed on one surface of an unfoamed polystyrene sheet having a thickness of 40 μm by using 175 L 4.
Coating is performed using a 0 μ gravure roll plate and dried at 50 ° C. for 5 seconds to form a primer layer. [Coating agent composition for forming primer layer] 15 parts by weight of acrylic resin (trade name; product of Acryloid F-10, Rohm & Haas) Cellulosic resin (trade name: product of CAB-381, Eastman Kodak) 2 parts by weight Isopropyl alcohol 45 parts by weight Ethyl acetate 12 parts by weight n-Butanol 26 parts by weight Next, a release layer-forming coating agent having the following composition was coated on the primer layer using a 135 L 60 μ gravure roll plate, Immediately place in a dryer at 80 ° C for 10 seconds to evaporate the solvent and add 40 more
The coating is allowed to stand for 24 hours in a dryer at 0 ° C. to cure the coating film and form a release layer. Acrylic polyol resin 100 parts by weight Amide wax 2.5 parts by weight Silicone oil 3.0 parts by weight Isocyanate curing agent 5 parts by weight Ethyl acetate 370 parts by weight Next, an acrylic resin adhesive on the other surface of the unfoamed polystyrene sheet (Trade name: E-3303S manufactured by Soken Kagaku Co., Ltd.) is 35 g / m ² after drying with a roll coater.
It was coated so that it would be, dried at 50 ° C. for 15 seconds, and then wound up and slit into a width of 50 mm to obtain a polystyrene adhesive tape. The physical properties of the obtained tape are shown in Table 1.

Example 3 A foamed polystyrene sheet (trade name; product of Rabek Sekisui Plastics Co., Ltd.) was coated with a coating agent for forming a primer layer having the following composition using a 175 L 40 μ gravure roll plate at 50 ° C. Dry for 5 seconds to form a primer layer. [Coating agent composition for forming primer layer] Acrylic resin (trade name; Acryloid B-66, product of Rohm & Haas) 15 parts by weight Cellulose resin (trade name: CAB-381, product of Eastman Kodak Company) 2 parts by weight Isopropyl alcohol 45 parts by weight Ethyl acetate 12 parts by weight Normal propyl acetate 26 parts by weight Next, a silicone resin (trade name; K) on the primer layer.
S-841, product of Shin-Etsu Chemical Co., Ltd.) 175 L 40, a coating agent for forming a release layer consisting of 30 parts by weight, platinum catalyst 2.5 parts by weight and methyl ethyl ketone 67.5 parts by weight.
coated with μ gravure roll plate, 110
The coating film is cured at 15 ° C. for 15 seconds to form a release layer. Then, an acrylic resin pressure-sensitive adhesive (trade name; E-3303S manufactured by Soken Chemical Co., Ltd.) was applied to the other surface of the expanded polystyrene sheet by a roll coater so that the coating film after drying was 35 g / m ^2, and the temperature was 50 ° C. After being dried for 15 seconds, it was wound and slit into a width of 50 mm to obtain a polystyrene adhesive tape. The physical properties of the obtained tape are shown in Table 1.

Comparative Example 1 A silicone resin (trade name: KS-841, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to one side of an unfoamed polystyrene sheet having a thickness of 40 μm.
A release layer-forming coating agent consisting of 30 parts by weight, platinum catalyst 2.5 parts by weight, and methyl ethyl ketone 67.5 parts by weight was coated with a 175 L 40 μ gravure roll plate, and the coating film was cured at 110 ° C. for 15 seconds and released. Form a mold layer. Next, an acrylic resin adhesive (trade name: E-3303S manufactured by Soken Chemical Co., Ltd.) was dried on the other surface of the unfoamed polystyrene by a roll coater to give a coating film of 35 g / m 2.
Apply so that it becomes ² , dry at 50 ° C for 15 seconds, and wind.
This was slit into a width of 50 mm to obtain a polystyrene adhesive tape. The physical properties of the obtained tape are shown in Table 1.

Comparative Example 2 A silicone resin (trade name: KS-841, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to one surface of an unfoamed polystyrene sheet having a thickness of 40 μm.
A release layer-forming coating agent consisting of 30 parts by weight, platinum catalyst 2.5 parts by weight, and methyl ethyl ketone 67.5 parts by weight was coated with a 175 L 40 μ gravure roll plate, and the coating film was cured at 110 ° C. for 15 seconds and released. Form a mold layer. Then, a vinyl chloride-vinyl acetate copolymer-based adhesive (trade name: SE
-3010 Showa High Polymer Co., Ltd.) is applied with a roll coater so that the coating film after drying will be 35 g / m ^2, and the temperature is 1 at 50 ° C.
After drying for 5 seconds, it was wound and slit into a width of 50 mm to obtain a polystyrene adhesive tape. The physical properties of the obtained tape are shown in Table 1.

The test methods used in the examples and comparative examples are as follows. Test method for peeling from the back Two pieces of each tape-shaped test piece are cut into 30 mm widths, and the two layers are attached to the test plate with the adhesive side facing down, and a rubber roller of 2 kg from the top of the test piece is about 300 mm. /
Reciprocate once at a speed of a minute to crimp. 20 to 30 minutes after crimping, the free part of the test piece is folded back 180 degrees, and after peeling off about 25 mm, the test piece is sandwiched by the upper chuck and the test plate is sandwiched by the lower chuck and the speed is 300 ± 30 mm / min. Peel off (based on JIS Z-0237).
Test Method of Adhesive Strength The adhesive surface / release layer surface was peeled off, the adhesive surface was attached to the styrene sheet surface, and the adhesive strength of the adhesive surface / styrene sheet surface was measured by the same method as in the back peel test.

[0015]

[Table 1]

[0016]

EFFECTS OF THE INVENTION The polystyrene pressure-sensitive adhesive tape of the present invention is not provided with a release layer directly on the surface of a polystyrene sheet substrate, but in particular, a primer layer is provided on the surface of the polystyrene sheet substrate, and a release layer is provided on that surface. It has much better releasability and superior workability than the polystyrene adhesive tape that has been directly subjected to the back surface peeling treatment. Further, the polystyrene pressure-sensitive adhesive tape of the present invention is unnecessary even if the tape is not peeled off when the tape base material itself is composed of polystyrene resin, when the tape is used by being attached to a foam polystyrene packing material, a fish box, or the like. It is particularly effective as a packing material made of expanded polystyrene and an adhesive tape for fish boxes, etc., because the packing material etc. that have become crushed can be crushed and recovered as recycled polystyrene resin.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoji Oku 1153-26 Komabe, Sowa-machi, Sarushima-gun, Ibaraki Prefecture (72) Inventor Masayuki Takahashi 3-7-12 Toyohashi, Kasukabe City, Saitama Prefecture (72) Inventor Nakano 2-28-18 Sagamidai, Sagamihara City, Kanagawa Prefecture (72) Inventor Katsumaro Takeshima 483-28, Toyoshiki, Kashiwa City, Chiba Prefecture

Claims (5)

[Claims] 1. A polystyrene pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on one surface of a polystyrene-based sheet base material, and a release layer not adhering to the pressure-sensitive adhesive layer on the other surface, which is separated from the polystyrene-based sheet base material. A primer layer is provided between the mold layers,
Further, as a coating agent for forming the release layer, 20 to 12
A polystyrene pressure-sensitive adhesive tape characterized by using an organic solvent solution of a reactive resin, which cures at 0 ° C. 2. The polystyrene pressure-sensitive adhesive tape according to claim 1, wherein the primer layer is formed by a paint or ink containing an acrylic resin as a constituent material of the vehicle. 3. The reactive resin is a polyurethane resin, polyurea resin, polyurethane polyurea resin, polyester resin, acrylic polyol resin, epoxy resin, polyamide resin, silicone resin, copolymer of olefin and acrylic monomer, polyvinyl acetate. 2. The polystyrene pressure-sensitive adhesive tape according to claim 1, which is one kind or two or more kinds selected from the group of partial saponification products, saponification products of copolymers of vinyl acetate and other monomers, and cellulosic resins. 4. The polystyrene pressure-sensitive adhesive tape according to claim 1, wherein the polystyrene-based sheet substrate is an unfoamed polystyrene sheet, a foamed polystyrene sheet, or a laminated sheet of an unfoamed polystyrene sheet and a foamed polystyrene sheet. 5. The expansion ratio of expanded polystyrene is 1.1 to 2.
The polystyrene pressure-sensitive adhesive tape according to claim 4, which is 0.