JPS5968385A - Hot-melt adhesive - Google Patents

Abstract

PURPOSE:A hot-melt adhesive firmly adherent to metal and plastic, and excellent in low-temp. fragility and high-temp. ahesion, which comprises an ethylene/ vinyl acetate copolymer, a polyamide resin and a specified block copolymer. CONSTITUTION:50-90wt% ethylene/vinyl acetate copolymer of hydrolysis rate of 50-90wt% and vinyl acetate content >=45wt% to which 0.1-50wt% unsaturated carboxylic acid is graft polymerized, 5-30wt% polyamide resin of amine value of 0.5-1.5, number average MW of 1,500-20,000, and ring and ball softening pt. of 80-180 deg.C, and 5-30wt% styrene/butadiene/styrene or styrene isoprene/styrene block copolymer of styrene content <=30wt% are mixed and, if necessary, a viscosity bodying agent such as a terpene resin, colorant, filler, antioxidant, etc. are added.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a hot-melt adhesive composition that has been improved to have strong adhesion to both metals and plastics.

[Background of the invention]

Hot-melt adhesives, so-called hot-melt adhesives, are well known for bonding metals and plastic compositions. It is widely known that hot melt adhesives are applied to, for example, heat-shrinkable sleeves, terminal caps, etc., and used for connection parts and terminal parts of electric cables, copper pipes, steel pipes, etc.

However, the hot-melt adhesives currently in use include various materials used for connections and terminals, such as evaporated iron, copper,
It has been difficult to adhere to all metals such as lead, aluminum, stainless steel, and steel, and synthetic resins such as polyethylene, polypropylene, polyvinyl chloride, polyester, chloroprene rubber, and ethylene propylene rubber. Some types of adhesive adhere to polyethylene and metals, but none adhere to polyvinyl chloride or polyester.

On the contrary, it adhered to polyvinyl chloride and polyester, but did not adhere at all to polyethylene and polypropylene.

Conventionally, ethylene-acetate-vinyl copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl acrylate copolymer, etc.
Ethylene acrylic acid-acrylic acid ester ternary obtained by hydrolyzing or thermally decomposing glycidyl meccrylate copolymer, ethylene/glycidyl methacrylate-vinyl acetate terpolymer, ioolemer resin, and ethylene acrylic ester copolymer. Copolymers and the like are known. However, these adhesives had insufficient adhesion to lead-sheathed cables, polyvinyl chloride-sheathed cables, and the like. Furthermore, although these ethylene adhesives have excellent low-temperature impact resistance, they have low high-temperature shear adhesive strength and high-temperature peel strength, resulting in displacement of bonded parts and gas leaks during actual use.

On the other hand, polyamide resins, saturated polyester resins, and the like are known for adhering polyvinyl chloride or polyester resins to metals such as copper, lead, and aluminum.

However, these did not adhere to polyethylene sheathed cables and also had very poor low temperature impact properties. If the cable was bent or subjected to impact at this low temperature, the adhesive would crack or peel, making it impossible to put it into practical use. However, in reality, the connection parts and terminal parts of power cables and communication cables are made of a combination of various materials, so it is extremely inconvenient that the adherends that can be bonded are limited as described above.

In addition, the environment in which electric wires and cables are used, as well as steel pipes and tubes, is changing from extremely low temperatures (-50"C) to high temperatures (90-C).
There was a need for a hot-melt adhesive that could withstand a wide temperature range of up to 1000 yen (2000 yen), but to date, there was no satisfactory material.

In order to solve these problems, a hot-melt adhesive made by blending the above-mentioned ethylene adhesive and the latter polyamide adhesive is disclosed in JP-A-56-122880.

Although this adhesive is a versatile adhesive that exhibits adhesion to various adherends, it has not been able to simultaneously satisfy both low-temperature and high-temperature properties.

The present invention provides a hot-melt adhesive that universally adheres to various metals and plastics and has better low-temperature brittleness and high-temperature adhesion than conventional adhesives.

[Summary of the invention]

The present invention was first obtained by mixing a specific ethylene copolymer, a specific polyamide resin, and a specific rubber in a predetermined ratio. Ethylene vinyl acetate copolymer and amine fiT[io, 5-15 polyamide resin 5-30
parts by weight, and styrene with a styrene content of 30% by weight or less.
The hot-melt adhesive is characterized by being mixed with 5 to 30% by weight of a block copolymer of Pukugen-styrene or styrene-isoprene-styrene.

[Detailed description of the invention]

Various types of hydrolyzate of the ethylene vinyl acetate copolymer can be obtained depending on the vinyl acetate content, melt index, and hydrolysis rate, but preferably the vinyl acetate content is 45% by weight or less, Hydrolysis rate is 5
0 to 90% by weight is preferable. The reason for this is that when the vinyl acetate content is 45% by weight or more, adhesive properties with polyolefins are poor, and heat stability and cold resistance are poor. Further, if the hydrolysis rate is less than 45% by weight, the melting point is low and the mechanical strength at high temperatures is low. If the hydrolysis rate is 90% by weight or more, the low-temperature impact resistance is poor and the melt viscosity is high. More preferably, after hydrolyzing the ethylene vinyl acetate copolymer, an unsaturated carboxylic acid of 01 to 5. o@p,i:
Oo Graft polymerization improves adhesion to metals.

Examples of ethylene-vinyl acetate copolymers with a hydrolysis rate of 50 to 90% by weight include, for example, Dumilan D-291, D-229, D-159, D-25 manufactured by Takeshi Pharmaceutical Co., Ltd.
,1,G-222,G-252,G-4,22,C-2
191°C-2271, C-1591, C-1570,
C-1580, C-1550, C-2280, etc. can be used.

Furthermore, polyamide resins with an amine ratio of 0.5 to 15 are polymers made by reacting dibasic acids called dimer acids with diamines, such as unsaturated fatty acids such as tall oil fatty acids and soybean oil fatty acids, adipic acid, and azelaic acid. Acid, heptapathic acid, etc. are added, and further ethylenediamine, hexamethylenediamine, influoronediamine, xylenediamine, 4-4'diaminodicyclohexylmethane, P-P
Examples include polyamide resins made by reacting methylene dianiline, piperidine, trimedelhexamethylene diamine, alkanolamine, etc. The obtained polyamide resin has a number average molecular weight of about 1500 to 2.
0000 range, ring and ball softening point is approximately 80°C ~
A temperature range of 180°C is good. Particularly preferred for the present invention are those with an amine value of 0.5 to 15. If the amine value is less than 0.4, the reactivity is poor and the adhesion to metals is poor, and if the amine value is 16 or more, the reactivity is poor. This is because it is highly susceptible to thermal deterioration, and furthermore, it has poor compatibility with the ethylene-vinyl acetate copolymer, leading to a decrease in adhesive strength.

The polyamide resin having an amine value of 0.5 to 15 of the present invention is manufactured by Henkel Nippon 0@ under the trade name Persalon 1128°13.
00.1138,1,139.1140.1165.1
175 etc. and Fuji Kasei Kogyo 0@ product name Tomide 394
゜509.1310,535,1350,512,56
5,500°575.1360 etc. can be used.

Further, as a block copolymer consisting of styrene/butadiene/styrene or styrene/inbrene/styrene with a styrene content of 30% by weight or less, Shell Kagaku fE's part name: CARIFLEX TR-1101 is used.

TR1102, TR-1184, TR-1107, TR
-1112°, Asahi Kasei's mounting products names Fuprene A, Tsuruprene T-1/II, Asabrene T i/3], and Tsuruprene T-475 can be used. In particular, block copolymers with a styrene content of 35% by weight or more are hard at low temperatures and do not exhibit rubber elasticity, and are not suitable as low-temperature modifiers for hot-melt adhesives. The block copolymer with a styrene content of 30% by weight or less is dispersed as fine rubber particles in the mixed resin of the ethylene vinyl acetate copolymer and polyamide resin, and exhibits a seabird structure, resulting in low-temperature brittleness and low-temperature impact. It has significantly improved properties such as adhesiveness and low-temperature adhesion, and exhibits properties that cannot be obtained with Ike's rubber or Ike's component systems.

The blending ratio of the three components of the present invention is preferably 50 to 90% by weight of the ethylene-vinyl acetate copolymer, and if it is less than 45% by weight, it will have poor adhesion with polyolefin resins, and if it is more than 90% by weight, it will not adhere to polyvinyl chloride resin or various metals. This is because the adhesion to the body becomes poor. Further, the content of the polyamide resin is preferably 5 to 30% by weight, and if it is less than 3% by weight, the adhesiveness to polyvinyl chloride resin and various metal bodies is poor, and the water resistance is poor. 35
This is because if the weight A% or higher, the adhesion to the polyolefin resin is poor and the low-temperature properties are poor. In addition, block copolymer 5
The content is preferably 30% by weight or less, and if it is less than 3% by weight, low temperature brittleness and low temperature impact properties will be poor, and if it is more than 35% by weight, the adhesion to various metal bodies will be poor.

In this way, the three components are essential conditions, but the total of the three components is a small amount of thickening agent such as terpene resin, terpene phenol resin, phenol resin, alkyl phenol resin, coloring agent, filler, etc. per 100 parts by weight. It is also possible to add several tens of parts of an anti-aging agent or the like from the base.

The following will be explained based on examples.

Example 1 Ethylene vinyl acetate copolymer (hereinafter abbreviated as EVA)
As Dumilan D-215 (hydrolysis rate -80%) and polyamide resin (hereinafter abbreviated as PAm) Toshite Persalon 1140 (amine 11Tli 80%, softening point 14.0
"C) and styrene, butadine, styrene (hereinafter SBS)
90:5:5.80:1 (1
: l (1,7U:15:15.6U:20:20,
The mixture was melt-kneaded at a weight ratio of 50:30:20.50:20:30 (kneader kneading at 150'c for 30 minutes) to obtain a hot-melt adhesive. Further press molding under 150'c 2.
Adhesive sheets of 0 thickness and 0.5 thickness were used as samples for the following performance test.

Performance test F.

2. OfIIM thickness adhesive sheet ASTM D-74-f
3, a low temperature embrittlement test was conducted to determine the low temperature embrittlement temperature.

Performance Test 2. An adhesive sheet having a thickness of 2.5 mm was subjected to a ring and ball softening point test according to ASTM E-28 to determine the softening point of the adhesive.

Performance test 3 Q. 5mm thick adhesive sheet 2. Sandwiched between a cross-linked polyethylene sheet (abbreviated as PE in Table 1) and a polyvinyl chloride sheet (PVC) with a thickness of 0m, m, and a copper plate (Cu), steel plate (Fe), and aluminum plate (A1) I50 ”C] Press bonded for 0 minutes, and after cooling, ASi-
A 180° peel test was conducted using MD-903. As a typical example, the adhesion between cross-linked polyethylene and a steel plate was tested in a -5°C1+90' atmosphere.The performance test results are shown in Table 1.

Example 2 Dumilan C-2270 (hydrolysis rate: 7
0%, unsaturated carboxylic acid content 0.5%) and Persalon 1165 (amine value 1.5, softening point 1) as PAm.
60℃) Tostyrene, Isoprene, Styrene (hereinafter SI
Califlex TR-1101 (abbreviated as S)
Styrene content 14%) and 9o:5:5.80:1
0:10.70:15:15.60:20:20.50
:30:20,50:20:30 weight ratio (
A hot-melt adhesive was obtained by kneading in a kneader at 150"C for 8 minutes.The obtained adhesive was subjected to the same performance test as in Example 1 to evaluate its performance. The results are shown in Table 2. Indicated.

Example 3 Dumilan C-1550 (hydrolysis rate -5) as EVA
5%, unsaturated carboxylic acid content 0.5%) and PAm-C Persalon 1358 (amine value -6, softening point 1.
1.0) and Turprene T-411 styrene content 30 as SBS) at 90:5:5, 80:10:10.
．． 7 (1: 1, “T: I 5, fio:
20:20.50:30:20.50: :g
o : : (melt kneading at a ratio of il'i- of 0 (150'
The mixture was kneaded in a C kneader for 130 minutes to obtain a hot-melt adhesive. The obtained adhesive was subjected to the same performance test as in Example 1 to evaluate its performance.

The results are shown in Table 3.

Comparative Example 1 The conventional hot-melt adhesives used were Evaflex, 162zo (EVA manufactured by Mitsui Polychemical Co., Ltd. with a hydrolysis rate of 0%) and Diamid T-45o (Nylon I2 copolymer manufactured by Daicel Chemical Industries, Ltd.). ) and Tuffden 200OR
(Styrene-butadiene comb manufactured by Asahi Kasei, styrene content 25%) 80:10:10.60:20:2
Melt kneading at a weight ratio of 0.4.0:30:30 (
The mixture was kneaded in a 150'C kneader for 30 minutes to obtain a hot-melt adhesive. The obtained adhesive was subjected to the same performance test as in Example 1 to evaluate its performance. The results are shown in Table 4. As can be seen from the performance test results in Tables 1, 2, and 3, the hydrolysis rate of the present invention was 50%. A flock copolymer consisting of ~90% ethylene vinyl acetate copolymer, a polyamide resin with an amine value of 05 to 15, and styrene/bookadiene/styrene or styrene/isoprene/styrene with a styrene content of 30% or less in total. The kneaded hot-melt adhesive has a low low-temperature embrittlement temperature and has excellent adhesive strength to various adherends from low to high temperatures. In particular, the ethylene-vinyl acetate copolymer may be graft-polymerized with 0.1 to 5.0% by weight of unsaturated carboxylic acid, and the polyamide resin preferably has a softening point in the range of 80 to 180°C. It is also found that the above blending ratio of 50 to 9 (] : 55 to 3,055,330 weight) is excellent.

On the other hand, as can be seen from the results in Table 4, the conventional kneaded product of ethylene vinyl acetate copolymer and polyamide resin Jlft Tostyrene Bucdiene rubber has poor low temperature embrittlement.
It was found that due to the high soft 1 hit point, sufficient adhesion strength with various adherends could not be obtained, making it impractical.

The hot-melt adhesive of the present invention can universally adhere to various types of 1yνγ, and has a high adhesive strength at high temperatures with 1v of low-temperature brittleness. This is excellent and proves the (1α) of the present invention.

Claims (1)

[Scope of Claims] (F,) Ethylene-vinyl acetate copolymer with a hydrolysis rate of 50-90% by weight and an amine value of 0.5% by weight.
5 to 30% by weight of the polyamide resin No. 15 and 5 to 30% by weight of a block copolymer consisting of styrene/butadiene/styrene or styrene/isoprene/styrene with a styrene content of 30% by weight or less. A hot-melt adhesive with special features. (2) The hot-melt adhesive according to claim (1), wherein the ethylene vinyl acetate copolymer is graft-polymerized with 0.1 to 5.0% by weight of unsaturated carboxylic acid. . (3) The hot-melt adhesive according to claim (1), wherein the polyamide resin has a softening point of 80 to 180°C.