JPH08253738A - Reactive self-adhesive tape and reactive self-adhesive sheet - Google Patents

Abstract

PURPOSE: To obtain a reactive self-adhesive tape or sheet which does not exhibit degradation in self-adhesiveness in sticking even after a long storage and which, when stuck to an adherend, cures by the reaction with water in air or of the adherend, exhibiting a good heat resistance. CONSTITUTION: This reactive self-adhesive tape or sheet is obtd. by forming an isocyanato-terminated reactive hot-melt self-adhesive compsn. into a thin film and winding the thin film together with a plastic film having a water content of 0.1% or lower around a core or by laminating the thin film to the plastic film and sealing the resulting laminate with a moistureproof packaging material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a reactive adhesive tape and a reactive adhesive which have good adhesive properties such that they can be easily adhered to each other only by pressure bonding at the time of laminating, and they cure after adhering and exhibit good heat resistance. The present invention relates to an adhesive sheet.

[0002]

2. Description of the Related Art Adhesive tapes and sheets having good adhesiveness, which can be easily adhered only by pressure bonding at the time of laminating, are widely used, but it is desired to keep the adhesiveness for a long time under high temperature conditions after laminating. In this case, means for using a pressure-sensitive adhesive that exhibits heat resistance by reacting with moisture in the air, moisture of an adherend, etc., has been developed.

[0003]

However, in such an adhesive tape and an adhesive sheet, when the adhesive tape and the adhesive sheet are used after being stored for a long time in an unused state, the adhesive gradually reacts and cures during storage. However, there are drawbacks such that the adhesiveness is lowered during the laminating, and it becomes difficult to simply attach the laminating materials only by pressure bonding. The present invention does not reduce the adhesiveness during bonding even when stored for a long period of time, and after bonding, it is reactive with moisture in the air and moisture of the adherend and exhibits good heat resistance. It is intended to provide an adhesive tape and a reactive adhesive sheet.

[0004]

The reactive pressure-sensitive adhesive tape and the reactive pressure-sensitive adhesive sheet of the present invention achieve such an object, and are a thin film of a reactive pressure-sensitive hot melt composition having an isocyanate group at the molecular end. Formed into a sheet shape, and a water content of 0.
Wound on a core of 1% or less and sealed with a moisture-proof packaging material, and a reactive adhesive hot-melt composition having an isocyanate group at the molecular end is formed into a thin film and has a water content of 0.1% or less. It is characterized in that it is laminated with the plastic film of and is sealed with a moisture-proof packaging material.

The reactive adhesive hot melt composition having an isocyanate group at the molecular end used in the present invention is a kneaded product of a base resin, a tackifying resin and a polyol having a hydroxyl group at the molecular end, and a hydroxyl group of the polyol. On the other hand, it is obtained by adding an excess polyisocyanate compound having a polyisocyanate group and carrying out an addition reaction. It is also possible to add a part of the kneaded product after the addition reaction of the polyisocyanate compound. As an example of the method for producing a hot melt composition, a base resin, a tackifying resin, and a polyol having a hydroxyl group at the molecular end are used together with a softening agent such as an aromatic process oil.
After kneading at 0 to 200 ° C. for about 90 minutes with a kneader until uniform, the kneaded product is put into a reaction kettle, and the diisocyanate compound is added at 80 to 120 ° C. to react under a nitrogen gas atmosphere.

The base resin used here is, for example, isoprene-styrene block copolymer (SI).
S), butadiene-styrene block copolymer (SB
S) and its hydrogenated polymers (SEBS / SEP
S), ethylene-vinyl acetate copolymer (EVA), ethylene acrylate copolymer (EEA), atactic polypropylene, thermoplastic linear polyester, etc., but isoprene-styrene block copolymer is particularly preferable in terms of adhesiveness. A polymer (SIS) is preferable, and a hydrogenated polymer (SEPS) of a butadiene-styrene block copolymer is preferable in terms of heat resistance.

Examples of the tackifying resin include terpene resins (terpene resin, terpene phenol resin, aromatic modified terpene resin, hydrogenated products thereof, etc.), petroleum resin (C ₅ aliphatic, C ₉ aromatic). Group, C ₉ aliphatic, hydrogenated products thereof, rosin ester resins (rosin ester, hydrogenated rosin ester, etc.), coumarone indene resin, styrene resin and the like can be used.

As the polyol, one or more compounds having good compatibility with the base resin and the tackifying resin and having a hydroxyl group at the terminal are used.
Examples of these polyols include terminal hydroxyl group-type hydrocarbon compounds such as polybutadiene or polyisoprene modified with terminal hydroxyl groups, hydrogenated polybutadiene, hydrogenated polyisoprene, polyester polyols obtained by condensing dicarboxylic acid and diol, and polyethylene glycol. Polyether glycols such as polypropylene glycol and polytetramethylene glycol.

Further, as the isocyanate compound to be reacted with the above-mentioned polyol, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,
Diisocyanates such as 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and xylylene diisocyanate, polyisocyanates such as triphenylmethane triisocyanate and polymethylene polyphenyl isocyanate, or isocyanate compounds thereof and trimethylolpropane, penta One or more adducts obtained by condensation with a polyhydric alcohol such as erythritol are used.

In the reactive adhesive hot melt composition of the present invention, the softening agent (aromatic process) used in the conventional hot melt adhesive is used within the range in which the object of the present invention can be achieved. Oils, liquid paraffin, etc., waxes (low molecular weight polyethylene, polymer waxes, etc.), and others (inorganic fillers, colorants, antiaging agents, etc.) can also be added.

When a polyisocyanate compound having an excess polyisocyanate group with respect to the hydroxyl groups of a polyol is added to a kneaded product of a base resin, a tackifying resin, and a polyol having a hydroxyl group at the molecular end, to carry out an addition reaction. The polyol having hydroxyl groups at both ends and the excess diisocyanate compound undergo an addition reaction, whereby a urethane prepolymer having isocyanate groups at both ends is obtained. In this case, the content of the isocyanate group in the urethane prepolymer is 1.5% by weight to 4.0.
% Is preferable, and when it is less than 1.5% by weight, the viscosity tends to increase as the molecular weight of the prepolymer increases, and when it exceeds 4.0% by weight, free isocyanate increases. However, the performance tends to decrease due to the inclusion of bubbles during curing, and the viscosity tends to decrease.

The reactive adhesive hot melt composition having an isocyanate group at the molecular end is melted in an applicator or the like at 100 to 120 ° C., then discharged by a T-die or the like to form a thin film and having a water content of 0. It is wound around a core having a water content of 0.1% or less with a plastic film (separator) of 1% or less, or laminated with a plastic film (separator) having a water content of 0.1% or less. The thickness of the thin film of the hot melt composition is preferably adjusted within the range of 50 μm to 5 mm. When used for adhesion to a rough surface, 100 μm or more is preferable.

When the thin film of the reactive adhesive hot melt composition is soft, it may be directly coated on a plastic film having a water content of 0.1% or less, and a water content of 0.
It may be impregnated with a nonwoven fabric having a water content of 1% or less and then wound around a core with a plastic film having a water content of 0.1% or less, or laminated with a plastic film having a water content of 0.1% or less. As the above-mentioned plastic film, a water content of 0.1% or less, preferably 0.05% or less is used, but it is desirable that a release treatment such as coating with a silicone-based release agent is performed. Examples of the plastic film having a water content of 0.1% or less include polyolefins such as polyethylene, polypropylene and polymethylpentene, halogen-substituted polyolefins such as polyvinylidene fluoride and polyfluorethylene, and polypropylene having a water content of 0.05% or less. Is preferred.

The obtained reactive adhesive tape and reactive adhesive sheet are sealed and stored in a moisture-proof packaging material. An aluminum bag having an inner surface coated with polyethylene is preferable in order to block moisture from the outside in consideration of stability during storage. It may be packaged using a sealable metal container.

[0015]

The reactive pressure-sensitive adhesive tape and the reactive pressure-sensitive adhesive sheet according to the present invention have good adhesiveness when they are laminated, so that they can be simply laminated together by pressure bonding like ordinary pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets. Moreover, after bonding, it reacts with the moisture in the air or the moisture in the adherend over time to improve the cohesive force, and the heat resistance and creep properties are improved like a heat resistant adhesive to show durability. Become. Then, by using a plastic film having a water content of 0.1% or less as a separator of the reactive adhesive tape and the reactive adhesive sheet, and further sealing in a moisture-proof packaging material, it is possible to suppress an increase in molecular weight due to a curing reaction during storage. Therefore, it is possible to maintain good adhesiveness during lamination for a long period of time.

[0016]

【Example】

Production Example 1 of Reactive Adhesive Hot Melt Composition (Composition 1) 100 parts by weight of isoprene-styrene block copolymer (Quintac 3435 manufactured by Zeon Corporation) and terpene resin (TO-105 manufactured by Yasuhara Chemical Co., Ltd.) After putting 135 parts by weight into a horizontal kneader and kneading at 180 ° C. for 60 minutes, 75 parts by weight of a terminal hydroxyl group type polybutadiene (R-45HT manufactured by Idemitsu Chemical Co., Ltd.) and an aromatic process oil (NS-made by Idemitsu Chemical Co., Ltd. 20 parts by weight of 100) were added and the mixture was kneaded for 30 minutes until it became uniform. 100 parts by weight of the obtained kneaded product is put in a reaction kettle and heated to 120 ° C.
16% by weight of diphenylmethane diisocyanate was added and reacted in a dry nitrogen gas atmosphere for 1 hour to obtain an isocyanate content of 3.5% by weight at 120 ° C.
A reactive adhesive hot melt composition having a melt viscosity of 7,000 cps (using a Brookfield type viscometer) was prepared.

Production Example 2 of Reactive Adhesive Hot Melt Composition (Composition 2) The same procedure as in Production Example 1 was repeated except that the amount of diphenylmethane diisocyanate added was 11 parts by weight, and the isocyanate content was 2.3 parts by weight. %, Melt viscosity at 120 ° C 19000 cps (using Brookfield viscometer)
Was produced.

Example 1 The above reactive adhesive hot melt composition (composition 1) was placed in an applicator at 130 ° C., heated and melted, and then discharged from a T die to form a thin film. Water content 0.
A polypropylene non-woven fabric having a basis weight of 15 g / m ² and a width of 100 mm and dried to 1% by weight [Permie manufactured by Unitika Ltd.] is coated so as to have a thickness of 300 μm, and a water content of 0.
Polypropylene film of 01% by weight or less [TOCELLO
SPOP-B1 manufactured by Co., Ltd., thickness 60 μm, width 100 mm] was wound around a polypropylene core having a water content of 0.1% by weight or less 30 times to prepare a reactive adhesive tape. As the moisture-proof packaging material, an aluminum bag laminated with polyethylene film was used. A reactive adhesive tape was put in the packaging material, the air in the packaging material was replaced with nitrogen, and then the packaging material was sealed. The results of measuring the performance of the obtained reactive adhesive tape after storing it for 6 months are shown in Table 1.

Example 2 A polypropylene film having a water content of 0.01% or less (P
A reactive adhesive tape was obtained in the same manner as in Example 1 except that a polymethylpentene film (PMP) having a water content of 0.01% or less was used instead of P). The results of measuring the performance after storage for 6 months in the same manner as in Example 1 are shown in Table 1.

Example 3 Reactivity as in Example 1 except that the reactive adhesive hot melt composition (composition 1) was used in place of the reactive adhesive hot melt composition (composition 1). An adhesive tape was obtained. The results of measuring the performance after storage for 6 months in the same manner as in Example 1 are shown in Table 1.

COMPARATIVE EXAMPLE 1 A polypropylene film having a water content of 0.01% or less (P
A reactive adhesive tape was obtained in the same manner as in Example 1 except that a polycarbonate film (PC) having a water content of 0.35% was used instead of P). The results of measuring the performance after storage for 6 months in the same manner as in Example 1 are shown in Table 1.

Comparative Example 2 A reactive adhesive hot melt composition (composition 2) was used in place of the reactive adhesive hot melt composition (composition 1), and a polypropylene film (water content 0.01% or less) was used. A reactive adhesive tape was obtained in the same manner as in Example 1 except that a polycarbonate film (PC) having a water content of 0.35% was used instead of PP). The results of measuring the performance after storage for 6 months in the same manner as in Example 1 are shown in Table 1.

[0023]

[Table 1]

The physical properties of the reactive adhesive tape were measured by the following methods. (1). Loop tack Reactive adhesive tape adhesive (hot melt composition) 2
After pressing to a thickness of 00 μm, it was adhered to kraft paper of 70 μm and cut into a width of 25 mm and a length of 300 mm to prepare a sample, which was set in a tensile tester in a loop shape with this adhesive surface as the outside. Immediately after bringing the loop-shaped adhesive surface of the sample into contact with the glass plate, pull it at a speed of 200 mm / min to separate them, and apply the load (Kg / 25 mm) when the adhesive surface of the sample and the glass plate are separated. The loop tack value was used. (2). Initial tensile shear strength The adhesive (hot melt composition) of the reactive adhesive tape was peeled off, pressed to a thickness of 200 μm, cut into a width of 25 mm, and the adhesive was sandwiched between two plywood boards. Immediately after pressing the plywood, both plywoods were pulled apart with a Tensilon tensile tester at a speed of 10 mm / min to measure the initial tensile shear strength.

(3). Tensile shear strength after curing for one week (2) Two plywoods laminated with each other at 20 ° C. in a thermo-hygrostat at 60% RH were left to cure for 1 week, and then ( The tensile shear strength was measured in the same manner as in 2). (4). Using the same sample as the temperature rising softening point (3) after curing for 1 week, 50g, 100g, 2
Suspending various loads of 00g and 300g separately, 2 ℃ /
The temperature was raised at a speed of min, and the temperature at the time of the drop was measured for each load. (5). Water content Measured according to ASTM D 570-63.

As is clear from Table 1, the reactive adhesive tapes of the comparative examples show a marked decrease in the adhesiveness during lamination after being stored for 6 months, whereas the reactive adhesive tapes of the present example. It can be seen that, even after being stored for 6 months, good adhesiveness at the time of laminating is maintained. Also, it can be seen that the reactive pressure-sensitive adhesive tape of the present example shows good heat resistance even after being stored for 6 months, reacting with moisture in the air with the passage of time after bonding to improve cohesive force.

[0027]

As is apparent from the above description, the reactive pressure-sensitive adhesive tape and the reactive pressure-sensitive adhesive sheet of the present invention have good pressure-sensitive adhesiveness even when they are laminated after being stored for a long period of 6 months or more. , With time, it reacts with the moisture in the air or the moisture of the adherend to improve the cohesive force and exhibits heat resistance close to that of a cross-linking reaction type adhesive,
Like ordinary pressure-sensitive adhesive tapes or pressure-sensitive adhesive sheets, it is possible to simply attach them simply by pressure bonding, and the heat resistance and creep properties are improved over time to near the level of heat-resistant adhesives, showing durability. Therefore, the reactive pressure-sensitive adhesive tape and the reactive pressure-sensitive adhesive sheet of the present invention are suitable for various applications related to automobiles, electric machines, construction, civil engineering, construction equipment, and woodworking, and particularly for sites where heat resistance is required. Since the reactive adhesive tape and reactive adhesive sheet are in the form of adhesive tape and adhesive sheet, they do not require special equipment and equipment for bonding, so they can be processed anywhere such as on-site construction and environmentally friendly. Also has the advantage of not being affected by pollution.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shiro Asai 1-4 Asanai, Ogaki-shi, Gifu Inside Tilement Technology Development Center Co., Ltd. (72) Hidenori Kato 1-4-4 Asani, Ogaki, Gifu Stock Company Tilement Technology Development Center

Claims (2)

[Claims] 1. A reactive adhesive hot melt composition having an isocyanate group at the molecular end is formed into a thin film and wound around a winding core having a water content of 0.1% or less together with a plastic film having a water content of 0.1% or less. A reactive adhesive tape characterized by being sealed with a moisture-proof packaging material. 2. A reactive adhesive hot melt composition having an isocyanate group at the molecular end is formed into a thin film and laminated with a plastic film having a water content of 0.1% or less,
A reactive pressure-sensitive adhesive sheet characterized by being sealed with a moisture-proof packaging material.