JPH10265746A - Pressure-sensitive adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a problem of rewinding of tape by slight shock of drop of tape roll, etc., in winding of a pressure-sensitive tacky tape around a material to be bonded due to high molecular weight of a natural rubber latex in the concentration-sensitive tacky tape comprising a polyvinyl-based film or sheet as a substrate produced by using a rubber-based emulsion type pressure sensitive adhesive composition consisting essentially of a natural rubber latex. SOLUTION: A rubber-based emulsion type pressure-sensitive adhesive composition comprising 100 pts.wt. (solid content) of the total of a natural rubber latex, a synthetic rubber latex and an ethylene/vinyl acetate/acrylic acid ester copolymer emulsion and 20-150 pts.wt. (solid content) of a tackiness providing resin emulsion as essential components is prepared. The total of the natural rubber latex and the synthetic rubber latex is 99-50 pts.wt. (solid content) in 100 pts.wt. (solid content) and the amount of the ethylene/vinyl acetate/acrylic acid ester copolymer emulsion is 1-50 pts.wt. (solid content) in 100 pts.wt. (solid content). A flexible polyvinyl chloride-based film or sheet is coated with the composition and dried.

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 tape obtained by applying a rubber emulsion type pressure-sensitive adhesive composition to a polyvinyl chloride film or sheet, particularly at a low temperature (for example, less than ± 0 ° C.). The present invention relates to a pressure-sensitive adhesive tape having remarkably improved impact rewinding resistance (no rewinding).

[0002]

2. Description of the Related Art Conventionally, pressure-sensitive adhesive tapes using a polyvinyl chloride film or sheet as a support have been produced by applying an organic solvent-based adhesive composition to the film or sheet and drying the film. Improvements are being sought because of the undesirable requirements of working environment pollution, air pollution, fire and explosion due to system diffusion. Particularly, instead of the organic solvent-based pressure-sensitive adhesive composition, a rubber-based emulsion-type pressure-sensitive pressure-sensitive adhesive composition is developed by mixing a natural rubber latex or a synthetic rubber latex with a tackifying resin, an antioxidant, or the like that has been emulsified. Have been.

However, for example, a pressure-sensitive adhesive tape made of a rubber-based emulsion-type pressure-sensitive adhesive composition mainly composed of natural rubber latex and having a support of a polyvinyl chloride film or sheet has a molecular weight of natural rubber latex. Since the tape is high, when wound on an adherend in a low temperature, the tape is rewound by a slight impact such as dropping the tape roll, and there is a problem that the adhesion to the adherend and the workability of winding are significantly reduced. Was.

[0004]

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a system comprising natural rubber latex and synthetic rubber latex and a tackifier resin emulsion has been developed. By laminating a rubber-based emulsion-type pressure-sensitive adhesive composition to which an acrylic ester copolymer emulsion has been added to a polyvinyl chloride resin layer as a support of the pressure-sensitive adhesive tape, the impact unwinding resistance at low temperatures is remarkably improved. It has been found that it can be improved (cannot be rewound), and the above problem has been solved.

[0005]

That is, the pressure-sensitive adhesive tape according to the present invention has a total of 100 parts by weight (solid content) of natural rubber latex, synthetic rubber latex and ethylene / vinyl acetate / acrylate copolymer emulsion.
And 20 to 150 parts by weight (solid content) of a tackifying resin emulsion as an essential component, and the total of the natural rubber latex and the synthetic rubber latex is 99 to 50 parts by weight (solid content) of the above 100 parts by weight (solid content). A rubber-based emulsion type pressure-sensitive adhesive composition comprising 1 to 50 parts by weight (solid content) of the above-mentioned ethylene / vinyl acetate / acrylic acid ester copolymer emulsion in 100 parts by weight (solid content) is flexible. This is a pressure-sensitive adhesive tape characterized by being applied to a polyvinyl chloride film or sheet having a property and dried.

The rubber-based emulsion-type pressure-sensitive adhesive composition contains natural rubber latex, synthetic rubber latex, ethylene / vinyl acetate / acrylate copolymer emulsion and tackifier resin emulsion as essential components. The ratio of each component is 100 parts by weight (solid content) of natural rubber latex, synthetic rubber latex and ethylene / vinyl acetate / acrylate copolymerized emulsion in terms of solid content, and 20 to 150 parts by weight of tackifying resin emulsion ( Solid component) as an essential component, and a total of 100 parts by weight (solid component) of natural rubber latex, synthetic rubber latex and ethylene / vinyl acetate / acrylic acid ester copolymer emulsion is 99 to 90% of the total of the above natural rubber latex and synthetic rubber latex. 5
0 parts by weight (solid content) and 1 to 50 parts by weight (solid content) of the ethylene / vinyl acetate / acrylate copolymer emulsion.

[0007] The reason why both the natural rubber latex and the synthetic rubber latex are blended in the rubber-based emulsion type pressure-sensitive adhesive composition is to balance the cohesive force and the adhesive force of the adhesive and to exert both. The mixing ratio varies depending on the material. As the synthetic rubber latex, styrene / butadiene copolymer rubber latex,
Chloroprene rubber latex, acrylonitrile / butadiene copolymer rubber latex, and the like.

[0008] The ethylene / vinyl acetate / acrylic ester copolymer emulsion is an acrylic ester 10
It is preferable to copolymerize 1 to 30 parts by weight of ethylene (solid content) and 1 to 40 parts by weight of vinyl acetate (solid content) with respect to 0 part by weight (solid content). The plasticizer resistance is poor, and if it is more than 30 parts by weight (solid content), the unwinding resistance at low temperatures and the feeling of hand adhesion are undesirably reduced. When vinyl acetate is less than 1 part by weight (solid content), heat resistance is poor, and when it is more than 40 parts by weight (solid content), impact unwinding properties at low temperatures and hand adhesion are undesirably reduced.

The acrylate ester has 1 to 8 carbon atoms such as methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate and cyclohexyl acrylate. Is preferably used and has 9 carbon atoms.
If the number is more than one, the polymer is too soft and the cohesive force of the rubber-based emulsion-type pressure-sensitive adhesive composition is lowered, which is not preferable. It is needless to say that a meta type, a normal type and the like can be appropriately adopted as the type of the acrylate.

As a method for copolymerizing ethylene and vinyl acetate with an acrylic ester, for example, an acrylic ester and vinyl acetate are emulsified in the presence of water and an emulsifier,
Further, there is a method of copolymerizing ethylene under high pressure.

The method for obtaining the tackifier resin emulsion used in the present invention includes rosin, modified rosin, polyterpene resin, aliphatic hydrocarbon resin, aromatic petroleum resin, phenolic resin, styrene resin, cumarone indene There is a method of obtaining a tackifier resin such as a system resin by sufficiently stirring the resin in the presence of, for example, a surfactant and water.

The rubber-based emulsion-type pressure-sensitive adhesive composition having the above essential components may contain additives such as an antioxidant, a filler, a pigment and the like as long as the essence of the composition is maintained.

As a specific example of the polyvinyl chloride synthetic resin film or sheet as the support used in the present invention, a plasticizer (for example, dioctyl phthalate or dibutyl phthalate) contains about 10 to 60 parts by weight (solids). Component) added polyvinyl chloride resin, polyvinyl chloride / vinyl acetate copolymer, polyvinyl chloride / chlorinated polyethylene, polyvinyl chloride / MBS (methyl methyl methacrylate / butadiene / styrene) resin, polyvinyl chloride・
There are NBR (nitrile rubber / acrylonitrile-butadiene copolymer) type and the like. In such a synthetic resin, additives such as an antioxidant, a filler, and a pigment can be added within a range that does not destroy the essence of the composition. . The use of the pressure-sensitive adhesive tape is not particularly limited, but includes, for example, for cans, electric insulation, bundling, and the like.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a rubber-based emulsion type pressure-sensitive adhesive composition which is applied to a flexible polyvinyl chloride film or sheet and dried on a pressure-sensitive adhesive tape is provided by a natural rubber latex. A total of 100 parts by weight (solid content) of synthetic rubber latex and ethylene-vinyl acetate-acrylate copolymer emulsion,
20 to 150 parts by weight (solid content) of the tackifier resin emulsion is an essential component, and the total of the natural rubber latex and the synthetic rubber latex is 99 to 50 parts by weight (solid content);
The ethylene / vinyl acetate / acrylic acid ester copolymer emulsion is formed at 1 to 50 parts by weight (solid content), thereby significantly improving the impact unwinding property at a low temperature (less than ± 0 ° C.) (rewinding). So that it disappears).

A typical method for producing a pressure-sensitive adhesive tape according to the present invention is as follows.

Method for producing ethylene / vinyl acetate / acrylic ester copolymer emulsion 100 parts by weight (solid content) of isobutyl (meth) acrylate, 20 parts by weight (solid content) of vinyl acetate, polyethylene glycol nonylphate in a stirrer 1 part by weight (solid content) of enyl ether and 175 parts by weight of water are added, the temperature is maintained at 30 ° C., and the atmosphere is replaced with nitrogen and stirred. Further, 4 parts by weight (solid content) of ethylene is added under pressure to obtain a copolymer emulsion.

Method for Producing Tackifying Resin Emulsion A polyterpene resin is previously dissolved by mixing 100 parts by weight (solid content) of a polyterpene resin, 2 parts by weight (solid content) of an antioxidant, and 40 parts by weight of toluene. Next, 5 parts by weight of polyethylene glycol nonylphenyl ether was added to 100 parts by weight (solid content) of the polyterpene resin, and the mixture was stirred, and 107 parts by weight of water and 1 part by weight of 25% ammonia water were gradually added thereto. Thereafter, the mixture is mixed with an emulsifier to obtain a tackifier resin emulsion. Further, the mixture is heated and stirred to recover toluene to make the amount of toluene 1 part by weight or less.

Method for producing rubber-based emulsion type pressure-sensitive adhesive composition 47 parts by weight of natural rubber latex (solid content), styrene.
With respect to 100 parts by weight (solid content) of a mixture of 47 parts by weight of butadiene copolymer latex (solid content) and 6 parts by weight of ethylene / vinyl acetate / isobutyl (meth) acrylate copolymerized emulsion (solid content) ,
100 parts by weight (solid content) of the tackifier resin emulsion prepared above is mixed, and an appropriate amount of a water-soluble cellulose ether is added as a thickener to obtain a rubber-based emulsion type pressure-sensitive adhesive composition.

Method for Producing Pressure-Sensitive Adhesive Tape An undercoating treatment is applied to a polyvinyl chloride resin film having a thickness of 0.16 mm to which 50 parts by weight (solid content) of dioctyl phthalate is added, and the treated surface of the film is dried. The rubber-based emulsion-type pressure-sensitive adhesive composition produced above was applied so that the coating amount was 22 to 28 g / m ^2, and 1
After drying at 20 ° C. for 3 minutes and winding it up on a paper tube, the pressure-sensitive adhesive tape of the present invention can be obtained.

[0020]

EXAMPLES Examples of the present invention will be described below in detail using comparative examples based on Table 1 which discloses the compounding ratio. Table 1 shows parts by weight of the solid content ratio of the rubber-based emulsion type pressure-sensitive adhesive compositions of the examples and comparative examples, and the impact rewinding resistance, adhesive strength and hand adhesion in these examples and comparative examples. It has been disclosed.

As shown in FIG. 1, the shock rewinding resistance is as follows: a tape reel 3 is slightly rewound by attaching a pressure-sensitive adhesive tape H left for 2 hours in a measurement room at -10.degree. Adhesively fix to the load W placed on the table 4, and then momentarily rotate the receiving table 4 in the direction of the arrow in the figure to measure how much the pressure-sensitive adhesive tape H is rewound by the impact. (Unit: mm). The adhesive strength (unit: N / 10 mm) is the adhesive strength to the stainless steel plate.
It is based on ISC 2336. In addition, when the adhesive surface of the pressure-sensitive adhesive tape was pressed with the belly of a finger, the feeling of hand adhesion was evaluated as ○;
And

[0022]

[Table 1]

The pressure-sensitive adhesive tape of the first embodiment is manufactured by the manufacturing method described in the above embodiment of the present invention.

The pressure-sensitive adhesive tape of the second embodiment is the same as that of the first embodiment.
Ethylene 8 parts by weight (solids) and vinyl acetate 16 parts by weight (solids) are based on 00 parts by weight (solids), and the main composition of the rubber-based emulsion-type pressure-sensitive adhesive composition is 40 parts by weight of natural rubber latex ( (Solid content), 40 parts by weight of styrene / butadiene copolymer rubber latex (solid content), and 20 parts by weight of ethylene / vinyl acetate / (meth) acrylic acid / isobutyl copolymerized emulsion (solid content).

The pressure-sensitive adhesive tape of the third embodiment is the same as the (meth) acrylic ester copolymer isobutyl 1
With respect to 00 parts by weight (solid content), ethylene is 12 parts by weight (solid content) and vinyl acetate is 12 parts by weight (solid content), and the main composition of the rubber emulsion type pressure-sensitive adhesive composition is 35 parts by weight of natural rubber latex ( (Solid content), 35 parts by weight of styrene / butadiene copolymer rubber latex (solid content), and 30 parts by weight of ethylene / vinyl acetate / (meth) acrylic acid / isobutyl copolymer emulsion (solid content).

The pressure-sensitive adhesive tape of the fourth embodiment is different from the isobutyl (meth) acrylate of the first embodiment in that (meth)
A mixture of acrylic acid and 2-ethylhexyl.

The pressure-sensitive adhesive tape of the fifth embodiment is different from the isobutyl (meth) acrylate of the first embodiment in that (meth)
It contains acrylic acid and tertiary butyl.

The pressure-sensitive adhesive tape of the first comparative example has a natural rubber latex and a synthetic rubber latex ratio of 50 parts by weight (solid content) in each of the first example, and an ethylene / vinyl acetate / acrylate copolymer emulsion. It was not blended.

The pressure-sensitive adhesive tape of the second comparative example has a natural rubber latex and a synthetic rubber latex ratio of 20 parts by weight (solid content) in each of the first examples, and an ethylene / vinyl acetate / acrylic ester copolymer emulsion. 6
0 parts by weight (solid content) is blended.

The pressure-sensitive adhesive tape of the third comparative example contains 10 parts by weight (solid content) of the tackifier resin emulsion of the first example.
The pressure-sensitive adhesive tape of the fourth comparative example is obtained by adding 170 parts by weight (solid content) of the tackifier resin emulsion of the first example.

As can be seen from the examples and comparative examples disclosed in Table 1, when the proportion of the ethylene / vinyl acetate / acrylic acid ester copolymer emulsion is low, all the tapes are rewound in the impact unwinding test. Poor results were obtained (see Comparative Example 1). Further, when the ratio was high, the impact rewinding resistance was reduced to some extent, and the adhesiveness and hand adhesiveness were poor (see Comparative Example 2). The adhesive strength is 1.0N / 10mm
The above are preferred values. When the amount of the tackifier resin emulsion was small, the three measurement results were poor (see Comparative Example 3), and when the amount was large, the impact rewinding resistance and hand tackiness were poor (see Comparative Example 4).

[0032]

The present invention relates to a pressure-sensitive adhesive tape,
A rubber-based emulsion-type pressure-sensitive adhesive composition which is applied to a flexible polyvinyl chloride-based film or sheet and dried, is combined with a natural rubber latex, a synthetic rubber latex and an ethylene / vinyl acetate / acrylate copolymer emulsion in a total of 100 parts by weight. (Solid content) and 20 to 150 parts by weight (solid content) of a tackifier resin emulsion are essential components. The total of the natural rubber latex and the synthetic rubber latex is 99 to 50 parts by weight (solid content),
A vinyl acetate / acrylate copolymer emulsion is formed in 1 to 50 parts by weight (solid content), thereby significantly improving the impact unwinding property at low temperatures (less than ± 0 ° C) (to prevent unwinding). )did.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a measuring machine for measuring the impact rewinding resistance of a pressure-sensitive adhesive tape in Examples and Comparative Examples of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 support 2 horizontal rod 3 tape reel 4 cradle H pressure-sensitive adhesive tape

Claims (1)

[Claims] 1. A total of 100 parts by weight (solid content) of a natural rubber latex, a synthetic rubber latex, and an ethylene / vinyl acetate / acrylate copolymer emulsion, and 20 to 150 parts by weight (solid content) of a tackifier resin emulsion.
The essential rubber latex and the synthetic rubber latex are combined in an amount of 99 to 50 parts by weight (solid content) of the above 100 parts by weight (solid content), and the ethylene / vinyl acetate / acrylic acid ester copolymer emulsion is mixed with the above 10% by weight.
A rubber-based emulsion type pressure-sensitive adhesive composition in an amount of 1 to 50 parts by weight (solid content) of 0 parts by weight (solid content) is applied to a flexible polyvinyl chloride film or sheet and dried. A pressure-sensitive adhesive tape characterized by the following: