JPS612778A - Hot-melt adhesive - Google Patents

Abstract

PURPOSE:The titled adhesive that is obtained mixing an ethylene-vinyl acetate copolymer, a specific polyamide and an epsilon-caprolactone polymer in a specific proportion, thus showing powerful adhesion to metals and plastics, and high operability. CONSTITUTION:The objective adhesive is obtained by using (A) a saponified ethylene-vinyl acetate copolymer with 45wt% vinyl acetate content calculated as ethylene-vinyl copolymer and a saponification degree of 50-90wt%, (B) a polyamide resin having 0.5-15 amine value, preferably softening point of 60-150 deg.C according to the ring and ball method and an average molecular weight of 1,500-20,000 and (C) an epsilon-caprolactone polymer in amounts of 30-70wt% of component A, 10-50wt% of B and 10-50wt% of C.

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]

It is well known to use hot melt adhesives to bond metals and plastic compositions. Hot melt adhesive e.g. heat shrink sleeve,
It is widely known that it can be applied to terminal caps, etc., and used for connection parts and terminal parts of electric cables, communication cables, steel pipes, steel pipes, etc.

However, the currently widely used hot-melt adhesives are made of various materials used for the above-mentioned connections and terminals, such as metals such as iron, copper, lead, aluminum, stainless steel, and steel, as well as polyethylene, polypropylene, and polyvinyl chloride. ,polyester,
It was difficult to adhere all scales to synthetic resins such as chloroprene rubber and ethylene propylene rubber. Some types adhered to polyethylene and metals, but did not adhere at all to polyvinyl chloride or polyester.

On the other hand, p was found to adhere to polyvinyl chloride and polyester, but not to polyethylene or polypropylene at all.

Conventionally, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, etc.
Ethylene acrylic acid-acrylic acid ester ternary obtained by hydrolyzing or thermally decomposing glycidyl meccrylate copolymer, ethylene/glycidyl methacrylate-vinyl acetate terpolymer, ionomer 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. In particular, when bonding to metal sheaths, metal tubes, etc., due to its good thermal conductivity, insufficient heating occurs due to heat dissipation, and due to insufficient adhesive strength, the bonded portion shifts or gas leaks occur 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. For this reason, if the cable was bent or subjected to impact at low temperatures, it would crack or peel at the adhesive, making it impractical. 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 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.

This adhesive is a versatile adhesive that exhibits adhesion to a variety of adherends, but in order to demonstrate its versatility, the adherend must be preheated to near the softening temperature of the adhesive, and heat-shrinkable had to be thoroughly heated. For this reason, simply shrinking the heat-shrinkable article results in poor adhesion to the adherend, poor insulation, gas leakage from the cable, and metal corrosion.

The present invention provides a hot-melt adhesive that can universally bond various metals and plastics without preheating and only by heat shrinkage of heat-recoverable articles, and has excellent bonding workability.

[Summary of the invention]

The present invention is obtained for the first time by mixing an ethylene copolymer, a specific polyamide resin, and a specific ε-caprolactone polymer in a predetermined ratio, and its gist is that an ethylene vinyl acetate copolymer and an amine Value 0.5-1
The hot-melt adhesive is characterized in that it is a mixture of 5 to 30 parts by weight of the polyamide resin No. 5 and a 6-caprolactone polymer.

[Detailed description of the invention]

Various types of ethylene-vinyl acetate copolymers can be obtained depending on the vinyl acetate content and melt index. For example, Sumitomo Chemical Co., Ltd. Chemical Co., Ltd. Product Master Worker/<71/Tux 550,450°420.410.
310,260,250.220.210°150.4
0 etc. can be used. Preferably, the saponified ethylene vinyl acetate copolymer has a vinyl acetate content of 45% by weight or less and a vinyl acetate hydrolysis rate of 50 to 90% by weight. The reason for this is that when the vinyl acetate content is 45% by weight or more, adhesive properties with polyolefin are poor, thermal stability is
This is because it has poor cold resistance. In addition, the hydrolysis rate is 45% by weight.
If the hydrolysis rate is less than 90% 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 properties are poor and the melt viscosity is high. More preferably, after hydrolyzing the ethylene-vinyl acetate copolymer, 0.1 to 5.0% by weight of unsaturated carboxylic acid is graft-polymerized, thereby further improving the adhesion to the metal.

Examples of ethylene-vinyl acetate copolymers with a hydrolysis rate of 50 to 90% by weight include Dumilan D-291, D-229, D-159, and D-251' manufactured by Takeda Pharmaceutical Co., Ltd.
, G-222, G-252, G-422, C-2191
.

C-2271, C-1591, C-1570, C-15
80, C-1550, C-2280 and Toyo Soda ■Product name H-6410, H-6810, Mersen H-682
0, H-6822.

H-6960 etc. can be used.

Furthermore, polyamide resins with an amine value of 0.5 to 15 are polymers made by reacting dibasic acids called dimer acids with diamines, such as adipic acid, azelaic acid, unsaturated fatty acids such as tall oil fatty acids, soybean oil fatty acids, etc. , sepatic acid, etc., and further add ethylenediamine, hexamethylenediamine, influoronediamine, xylenediamine,
4-4'diaminodicyclohexylmethane, P-P
Examples include polyamide resins reacted with methylene dianiline, piperidine, trimethylhexamethylene diamine, alkanolamine, etc.

The obtained polyamide resin has a number average molecular weight of about 1500 to 2.
0000 range, and the ring and ball softening point is approximately 60'G.
A temperature range of -150°C is preferable. In particular, in the present invention, those with an amine value of 0.5 to 15 are preferable, and those with an amine value of 0.
．． If the amine value is less than 4, the reactivity is poor and the adhesion to metals is poor, and if the amine value is 16 or more, the reactivity is strong and it is easily susceptible to thermal deterioration, and furthermore, the compatibility with ethylene vinyl acetate copolymers is poor, resulting in poor adhesion. This is to cause a decline.

The polyamide resin having an amine value of 0.5 to 15 used in the present invention is manufactured by Henkel Japan and has the trade name Persalon 1128°130.
0.1301, 1302, 1138, 1139.114
0゜1165.1175 etc. and product name Tomide 394,509.1'310,535,135 manufactured by Fuji Kasei Kogyo ■
0,512°565.500,575.1360, etc. can be used.

Furthermore, as the ε-caprolactone polymer, the product name Plaxel H-1°) (-4,H-
7, G-701, G-702, G-401, etc., which have a number average molecular weight of several thousand to several thousand and a melting point of 50 to 90°C can be used.

The blending ratio of the three components of the present invention is preferably 30 to 70% by weight of the ethylene vinyl acetate copolymer. If it is less than 30% by weight, it will have poor adhesion with polyolefin resins, and if it is more than 70% by weight, it will not be able to adhere to polyvinyl chloride resin or various metals. This is because the adhesion to the body becomes poor.

In addition, the polyamide resin is preferably 10 to 50% by weight.
If the amount is less than % by weight, adhesion to polyvinyl chloride resin and various metal bodies is poor, and water resistance is poor. This is because if it exceeds 50% by weight, the adhesion to the polyolefin resin will be poor and the low temperature properties will be poor. Furthermore, ε-caprolactone polymer has 10 to 50
This is because if the amount is less than 10% by weight, the adhesion will be poor unless the adherend is preheated, and if it is more than 50% by weight, the low temperature brittleness and low temperature impact properties will be poor.

In this way, the three components are essential conditions, but if the total of the three components is 100 parts by weight, a small amount of thickening agent such as terpene resin, terpene phenol resin, or phenol tree JII is used as a thickening agent.
, alkyl phenolic resins, low-temperature modifiers such as styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, natural rubber, butyl copolymers, coloring agents, fillers, and anti-aging agents. It is also possible to add several parts to several tens of parts of agents, etc.

The following will be explained based on examples.

Example 1 Sumitate HE-10 (manufactured by Sumitomo Chemical Co., Ltd. VA=
20%MI=3009 and polyamide resin (hereinafter referred to as PA
Persalon 1300 (amine value: 0°5, softening point: 95°C) as C-caprolactone polymer (abbreviated as m) and Plaxel H-4 as C-caprolactone polymer were mixed in 70:15:15,6.
0+20:20,50:25:25,40+3030.
A hot-melt adhesive was obtained by melt mixing (mixing in a kneader at 130° C. for 30 minutes) at a weight ratio of 30:40:30 and 30:30:40. Further, the adhesive sheets were press-molded under 100'e to obtain adhesive sheets of 2.0 M thickness and 0.5 mm thickness, which were used as specimens for the next performance test.

Performance Test 1 A low temperature embrittlement test was performed on an adhesive sheet having a thickness of 2.0 M according to ASTM D-746 to determine the low temperature embrittlement temperature.

Performance Test 2 A 2.0 M thick adhesive sheet 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 An adhesive sheet of 0,5 all thickness was inserted between a 2.0 fl thick crosslinked polyethylene sheet (abbreviated as PE in Table 1) and a steel plate, and a polyvinyl chloride sheet CPVC> and a steel plate for 80'. C, press bonded for 3 minutes each at 100°C and 120°C, and after cooling, 180% by ASTM D-908K.
A peel test was conducted.

The bonding temperature of 80 DEG C. to 120 DEG C. is a temperature that can be easily reached by the inner layer adhesive when the heat-recoverable article is heated and shrunk from the outside. The performance test results are shown in Table 1.

Example 2 Dumilan C-2270 (hydrolysis rate: 7096, unsaturated carboxylic acid content: 0.596) as EVA,
PAm as Persalon 1302 (10 in amine value)
, softening point 75°C) and Plaxel H-'I as the ε-caprolactone polymer at 70:15:15,60.
:20:20,50:25:25,40:30:30.
A hot-melt adhesive was obtained by melt mixing (kneader mixing for 30 minutes at 130°C) at a weight ratio of 30+40:jO, 30:30:40.The resulting adhesive was subjected to the same performance test as in Example 1. We conducted a performance evaluation. The results are shown in Table 2.

Example 3 Dumilan C-1550 (hydrolysis rate: 5596, unsaturated carboxylic acid content: 0.5%) as EVA and PA
Persalon 1358 (amine value: 6, softening point: 1)
40″C) and plaque as ε-caprolactone polymer.
bkH-7 70:15:15, 60:20:20゜50:25:25, 40:30:30, 30:40:3
Melt mixed wire (13
0'c kneader cross-talk 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 3.

Comparative Example 1 The conventional hot-melt adhesive used was Evaflex 16220 (EVA manufactured by Mitsui Polychemicals, hydrolysis rate 0%) and Persalon 1165 (Amine Eugenic 8 softening point 165°C) in a ratio of 80:20. 60:40, 40°+60,
The mixture was melt-kneaded at a weight ratio of 20:80 (kneading at 150° C. for 80 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 ethylene vinyl acetate copolymer of the present invention and the amine value 0
．． A hot-melt adhesive prepared by kneading a polyamide resin of No. 5 to 15 and an ε-caprolactone polymer has excellent adhesive strength to various adherends when heated at a low temperature for a short time. In particular, the polyamide resin preferably has a softening point in the range of 60 to 150°C. Also, the above blending ratio is 30-70:10-50:1
It can be seen that a ratio of 0 to 50% by 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 has a high softening point, so it has a high adhesive strength with various adherends when heat bonding is performed at low temperature for a short time. It was found that this method was not practical as it did not provide sufficient results.

〔Effect of the invention〕

Claims (3)

[Claims] (1) 30-70% by weight of ethylene-vinyl acetate copolymer and 10-50% of polyamide resin with an amine value of 0.5-15.
% by weight and ε-caprolactone polymer 10-50% by weight
A hot-melt adhesive characterized by being mixed with. (2) Hydrolysis rate of ethylene vinyl acetate copolymer is 50
The hot-melt adhesive according to claim 1, which is a saponified ethylene vinyl acetate copolymer containing ~90% by weight. (3) The hot-melt adhesive according to claim (1), wherein the polyamide resin has a softening point of 60 to 150°C.