JP2000345128A - Hot-melt adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hot-melt adhesive composition showing extremely excellent adhesion performances of so-called hardly bondable materials such as polyolefin materials, for example, polypropylene and polyethylene which have been difficult to bond, since extension in the application range of hot-melt adhesives and a hot-melt adhesive showing excellent adhesion performances have been required. SOLUTION: This hot-melt adhesive composition comprises 5-50 wt.% of (a) an ethylene-vinyl acetate copolymer, 5-50 wt.% of (b) a saponified substance of ethylene-vinyl acetate copolymer, 5-50 wt.% of (c) an ethylene-acrylic acid ester copolymer, 5-40 wt.% of (d) a tackifier resin and <=8 wt.% of (e) an amide wax.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt adhesive composition which exhibits good adhesive performance even if a surface treatment is not performed on a difficult-to-bond material such as a polyolefin material.

[0002]

2. Description of the Related Art A hot-melt adhesive is an adhesive made of a thermoplastic resin which melts when heated, is applied to the surface of an adherend, and then exhibits an adhesive function when cooled. Excellent economy. As a general method of applying a hot melt adhesive, a method of applying a molten adhesive by applying pressure by a pump to elute from a nozzle, a method of applying a molten adhesive by a roll coater, and the like are used.

[0003] The adherends to be bonded are metal, resin, rubber,
There are a wide variety of paper and wood. The environment in which the bonded products are used ranges from a mild indoor environment to a high-temperature, high-humidity outdoor environment.

[0004]

In recent years, as the application range of hot-melt adhesives has been expanded, hot-melt adhesives exhibiting good adhesion performance to so-called difficult-to-bond materials such as polyolefin materials, such as polypropylene and polyethylene, which have conventionally been difficult to bond. Agents are desired.

[0005]

Means for Solving the Problems The present inventors searched for various modifiers and found that ethylene-vinyl acetate copolymer (a), saponified ethylene-vinyl acetate copolymer (b), ethylene-acrylic acid By properly blending the ethyl ester copolymer (c), the tackifier resin (d) and the amide wax (e), it becomes possible to bond difficult-to-bond materials such as polyolefin materials without any surface treatment. Heading, the present invention has been completed.

That is, in the present invention, 5 to 50% by weight of ethylene-vinyl acetate copolymer (a), 5 to 50% by weight of saponified ethylene-vinyl acetate copolymer (b), A hot melt adhesive composition comprising 5 to 50% by weight of a polymer (c), 5 to 40% by weight of a tackifier resin (d), and 8% by weight or less of an amide wax (e). .

Hereinafter, the present invention will be described in more detail.
The amount of the ethylene-vinyl acetate copolymer (a) used in the present invention is preferably 5 to 50% by weight, and 10 to 4% by weight.
0% by weight is a more preferable range. 5% by weight
If it is less than 5, adhesion performance to polyolefin is reduced, and 5
If it exceeds 0% by weight, the heat resistance as an adhesive decreases.

As the ethylene-vinyl acetate copolymer (a) used in the present invention, a commercially available ethylene-vinyl acetate copolymer is preferably used, but the one having a vinyl acetate content of 10% by weight or more is preferable, Are more preferred. Specific examples include, for example, Evatate and Sumitate manufactured by Sumitomo Chemical Co., Ltd., Ultracene manufactured by Tosoh Corporation, Evaflex manufactured by Mitsui Dupont Chemical Company, and the like.

The amount of the saponified ethylene-vinyl acetate copolymer (b) used in the present invention is preferably 5 to 50% by weight, more preferably 10 to 40% by weight. When the amount is less than 5% by weight, the heat resistance as an adhesive decreases, and when the amount exceeds 50% by weight, the bonding performance to polyolefin decreases.

The saponified ethylene-vinyl acetate copolymer (b) used in the present invention is obtained by saponifying a generally commercially available ethylene-vinyl acetate copolymer by a known method. The saponification rate and MFR (melt fluidity) are not particularly limited, but the saponification rate is 20 to 90%, and the MFR is 0.1 to 500.
g / 10 minutes (190 ° C.) is preferably used. Specific examples include Technolink manufactured by Taoka Chemical Industry Co., Ltd., Mersen manufactured by Tosoh Corporation, and Dumilan manufactured by Takeda Pharmaceutical Company Limited.

The preferred amount of the ethylene-acrylic acid ethyl ester copolymer (c) used in the present invention is 5 to 50% by weight, more preferably 10 to 40% by weight. Less than 5% by weight and 50% by weight
If it exceeds, the adhesive performance to polyolefin will be reduced.

The ethylene-acrylic acid ethyl ester copolymer (c) used in the present invention is generally commercially available and has an acrylic ester content of 5 to 40% by weight, preferably 15 to 30% by weight. Are preferably used. Specific examples include, for example, Evaflex-EEA manufactured by Mitsui Dupont Chemical Co., Ltd., NUC manufactured by Nippon Unica, and the like.

The amount of the tackifying resin (d) used in the present invention is preferably 5 to 40% by weight, more preferably 10 to 30% by weight.
Is a more preferable range. If the amount is less than 5% by weight, the melt viscosity of the composition becomes high, and the coating workability deteriorates. On the other hand, if it exceeds 40% by weight, the heat resistance as an adhesive decreases.

The tackifying resin (d) used in the present invention
Is generally commercially available, and includes rosin-based, terpene-based or olefin-based resins. Examples of the rosin-based tackifying resin used include gum rosin, wood rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, dimerized rosin, and rosin phenol resin. Terpene-based tackifying resins include terpene resins, copolymers of terpene and styrene, terpene and α
-Methyl styrene, terpene and phenol, and their water additives. Specific examples include YS resin PX and YS resin manufactured by Yasuhara Chemical.
Resin PXN, YS Resin TO, Clearon P, YS Resin A and YS Resin A, Marcalez T, Marcalez R, Marcalez M, and Marcalez H by Maruzen Petrochemical Co., Ltd .; No. Examples of the olefin-based tackifier resin include Ubetac manufactured by Ube Industries, and polybutene manufactured by Nippon Petrochemical Co., Ltd. The tackifier resin used in the present invention may be used alone, or two or more kinds having different types and softening points may be used in combination.

The amide wax (e) used in the present invention is usually used as a release agent or a lubricant, and is not an essential component in the hot melt adhesive composition of the present invention. e) In the hot melt adhesive composition of the present invention, the effect of improving the adhesive strength was recognized. The preferred compounding amount of the amide wax (e) is 0.3 to 8.0% by weight, and the more preferred range is 0.5 to 5.0% by weight. If the amount is too small, the effect of improving the adhesive strength is small, while if it is added in an amount of 8% by weight or more, no further improvement in the adhesive strength is observed. Amide waxes having 16 or less carbon atoms or 22 or more carbon atoms have a small effect of improving the adhesive strength.

The amide wax (e) used in the present invention is generally commercially available and includes stearic acid amide, oleic acid amide, erucic acid amide,
And behenic acid amide. As a specific example,
Examples include Neutron, Neutron BNT, Neutron SNT, and Neutron PNT manufactured by Nippon Seika.

In the hot melt adhesive composition of the present invention, if necessary, other thermoplastic resins, rubbers, adhesives,
A plasticizer, a filler, a lubricant, an antiblocking agent, an antioxidant, an anti-coloring agent and the like can be appropriately compounded.

[0018] Those which can be suitably blended in the present invention include:
For example, ethylene-acrylic acid copolymers such as ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, styrene-based thermoplastic elastomer, polyvinyl chloride (PVC), polyamide (nylon 6, etc.), polyester, Rubber (SBR, NR, IR, IIR, etc.),
Polyvinyl acetate, polyvinyl alcohol (PVA), polyester, polycarbonate, polyvinyl ether,
Examples include polyurethane and amorphous polyalpha-olefin.

As the equipment for producing the hot melt adhesive, any equipment having a function of heating, stirring or kneading may be used, and equipment conventionally used for the production of hot melt adhesives can be used. Such manufacturing facilities include:
For example, a single-screw or twin-screw extruder, a ribbon mixer, a kneader, a Banbury kneader and the like can be mentioned. Melt kneading must be performed under conditions that do not cause gelation of the compound, and varies depending on the kneading machine.
Kneading at 30 ° C. for 30 seconds to 60 minutes is preferred.

[0020]

The hot-melt adhesive composition of the present invention comprises:
It shows extremely good adhesion performance without performing surface treatment on so-called poor adhesion materials such as polyolefin.

[0021]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Saponified ethylene-vinyl acetate copolymer (Technolink R-400 manufactured by Taoka Chemical Co., Ltd.) 24.5% by weight, ethylene-vinyl acetate copolymer (Evaflex EV45X manufactured by Du Pont-Mitsui Chemicals) 5% by weight of ethylene-acrylic acid ethyl ester copolymer (NUC-6 manufactured by Nippon Unica)
070) 24.5% by weight, terpene-based tackifying resin (YS resin TO-105 manufactured by Yasuhara Chemical Co., Ltd.) 24.5% by weight, amide wax (Nippon Seika Co., Ltd. BNT-22H)
2% by weight was melt-kneaded using a twin-screw kneader to obtain a hot melt adhesive composition. This was formed into a film having a thickness of about 300 μ at a temperature of 150 ° C. using a press forming machine.

Using the obtained film, a polypropylene having a width of 25 mm, a length of 100 mm and a thickness of 2 mm (hereinafter referred to as P
P) or polyethylene (hereinafter abbreviated as PE) test piece (manufactured by Nippon Test Panel Co.) with a width of 25 mm and a length of 150
mm, a 0.3 mm thick aluminum test piece (manufactured by Nippon Test Panel Co., Ltd.) with a pressing pressure of about 0.3 kg / cm ² , a temperature of 110 ° C.
Bonding was performed for 15 minutes.

The normal 180-degree peel strength (tensile speed: 50 mm / min, 25 ° C.) of the adhesive test piece was measured.
It described in.

In addition, PP sheets having a thickness of 300 μm were adhered to each other under the same conditions, and the T-peel strength (tensile speed: 50 mm / min, 25 ° C.) of the adhesive test piece was measured. The results are shown in Table 1.

Examples 2 to 4 The hot melt adhesive compositions having the compositions shown in Table 1 were used in Example 1.
Then, an adhesive film was prepared in the same manner as in Example 1 using a press molding machine. Using these films, the adhesion between PP and PE and aluminum and the adhesion between PP were evaluated, and the results are shown in Table 1.

Comparative Examples 1 to 5 A hot melt adhesive composition was prepared in which one component in Example 1 was not blended and the remainder was blended in an equal ratio (Comparative Examples 1 to 5).
3) Using the hot melt adhesive composition (Comparative Examples 4 and 5) in which one component of Example 1 was excessively mixed, three kinds of adhesive test pieces were prepared in the same manner as in Example 1, and the adhesion was performed. Sex evaluation was performed.

Table 1

Table 2

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J040 BA052 BA062 BA202 DA051 DA061 DA132 DA151 DA152 DB042 DB082 DE031 DE032 DF041 DF042 DN032 DN072 EL012 GA05 HC10 JA08 JB01 KA26 LA06 MA11

Claims (6)

[Claims] 1. An ethylene-vinyl acetate copolymer (a) containing 5
50 to 50% by weight, saponified ethylene-vinyl acetate copolymer (b) 5 to 50% by weight, ethylene-ethyl acrylate copolymer (c) 5 to 50% by weight, tackifying resin (d) 5 to 40% by weight and amide wax (e)
Is 8% by weight or less. 2. The hot melt adhesive composition according to claim 1, wherein the ethylene-vinyl acetate copolymer (a) has a vinyl acetate content of 10% by weight or more. 3. The saponified ethylene-vinyl acetate copolymer (b) has a saponification ratio of 20% to 90%.
The hot melt adhesive composition according to any one of the above. 4. The ethylene-acrylic acid ethyl ester copolymer (c) has an acrylic acid ethyl ester content of 5% by weight.
The hot melt adhesive composition according to any one of claims 1 to 3, wherein the content is from about 40% by weight to about 40% by weight. 5. The hot melt adhesive composition according to claim 1, wherein the tackifying resin (d) is a rosin-based or terpene-based resin. 6. The amide wax (e) having 17 to 2 carbon atoms.
The hot melt adhesive composition according to any one of claims 1 to 4, wherein the composition is one aliphatic amide.