JPS602177B2 - heat recoverable articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat recovery article that can reliably coat and seal objects made of various metals, plastics, or combinations thereof.

Connections and terminals of power cables, communication cables, steel pipes, steel pipes, etc. require performances such as insulation, water resistance, and sealing properties, so heat-recoverable sleeves with heat-melting adhesive applied to the inner surface, Heat recovery products such as terminal caps are widely used. However, the hot-melt adhesives currently used in heat recovery products are compatible with various materials used for the connections and terminals, such as metals such as iron, copper, lead, aluminum, and stainless steel, as well as polyethylene and polypropylene. It was difficult to adhere all scales to synthetic resins such as polyvinyl chloride and polyester.

Some types adhered to polyethylene and metals, but did not adhere at all 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. For bonding polyolefin resins such as polyethylene and polypropylene to metals such as copper, iron, and aluminum, use ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ionomer resin, ethylene glycidyl methacrylate copolymer, ethylene glycidyl methacrylate-vinyl acetate copolymer, ethylene Ethylene acrylic acid-acrylic ester ternary copolymers obtained by hydrolyzing or thermally decomposing acrylic ester copolymers 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 period adhesion strength and high-temperature peel strength, resulting in displacement of connections 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. For this reason, if the cable is bent or subjected to impact at low temperatures, the bonded portion will crack or peel, making it impractical. However, in reality, various combinations of materials are used for the connections and terminals of power cables and communication cables, and many types of plastics and rubbers, such as polyolefin resins and polyvinyl chloride resins, are used as materials for heat-recoverable products. Therefore, it is extremely inconvenient that the adhesive bodies 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 pipes, etc., has recently changed from extremely low temperatures (about 140 degrees Celsius) to high temperatures (80 degrees Celsius).
Although there has been a demand for heat-recoverable articles coated with hot-melt adhesives that can withstand a wide temperature range (up to 100%), there has been no satisfactory product yet.

In order to solve these problems, a method of mixing the above-mentioned ethylene-based adhesive and the latter polyamide-based adhesive was considered, but the compatibility between the two is poor, and simply mixing the two components is not enough. It was not possible to get glue for the mold.

The present invention provides a heat-recoverable article that can reliably cover and seal objects made of various metals and plastics. A layer is provided by applying a hot-melt adhesive that universally adheres to the substrate and has excellent low-temperature impact resistance. The adhesive according to the present invention is obtained for the first time by mixing a specific ethylene copolymer and a specific polyamide resin in a predetermined ratio, and is a heat-melting type that maintains excellent low-temperature impact resistance and high-temperature adhesion. It is an adhesive.

Specifically, it is a hot-melt adhesive made by mixing ethylene vinyl acetate copolymer with a hydrolysis rate of 50 to 9% by weight and a polyamide resin with an amine value of 3 to 30 in a weight ratio ranging from 90:10 to 60:40. be. Various types of ethylene vinyl acetate copolymer hydrolyzate 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 and the hydrolysis rate is 45% by weight or less. 50 to 9% by weight is good.

This is because if the vinyl acetate content is 45% by weight or more, the post-adhesiveness with polyolefin is poor, and the thermal stability and cold resistance are poor. Further, if the hydrolysis rate is 45% by weight or less, the melting point is low and the mechanical strength at high temperatures is low.If the hydrolysis rate is 95% 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 0.1 to 5. weight% of
Graft polymerization improves adhesion to metals. Examples of ethylene-vinyl acetate copolymers with a hydrolysis rate of 50 to 9% by weight include Dumilan ○-291, D-229, D-159, and D-2 manufactured by Takeda Pharmaceutical Co., Ltd.
51, G-222, G252, G-422, C-219
1, C-2271, C-1591, C-1570, C-
It can be used for 1580, C-1550, C-2280, etc. Furthermore, polyamide resins with an amine value of 3 to 30 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, azelaic acid, and sebacic acid. etc., and further ethylenediamine, hexamethylenediamine, isophore.

The polyamide resin is a polyamide resin reacted with diamine, xylylene diamine, 4-ediaminodicyclohexylmethane, P1P'-methylene dianiline, piperazine, trimethylhexamethylene diamine, alkanolamine, etc.
The obtained polyamide resin has a number average molecular weight of about 1500 to 2.
0000 range, with a ring and ball softening point of about 80℃~2
A value in the range of 0000 is good. In particular, in the present invention, those having an amine value of 3 to 30 are preferable; if the amine value is less than 2.5, the reactivity is poor and the adhesion with metals is poor, and if the amine value is 35 or more, the reactivity is strong and it is susceptible to thermal deterioration. This is because the compatibility with the ethylene-vinyl acetate copolymer is poor, leading to a decrease in adhesive strength. Amine value of the present invention is 3~
30 polyamide resins include Henkel Japan's product name Barsalon 11281300, 113 & 1139,1.
140, 1164, 1165, 1175, etc., and product name Dormide 394, 509, 1310, manufactured by Fuji Chemical Industry ■.
535, 1350, 512.565, 500, 575,
1360, etc. can be used.

Furthermore, the hot-melt adhesive used in the present invention contains a small amount of viscous agent such as terbene resin, terbenphenol resin, phenolic resin, alkylphenol resin, coloring agent, filler, anti-aging agent, etc. It is also possible to add.

In the heat-recoverable article of the present invention, the heat-recoverable rubber or plastic layer is in the shape of a sleeve, cap, tape, etc. It is obtained by crosslinking it by irradiating it with electron beams or adding a chemical crosslinking agent, then expanding or stretching it in a heated state, and cooling it as it is. It has the property of recovering to its shape. The following will explain based on examples.

Example 1 Dumilan D-215 (hydrolysis rate mainly 80%) and Barsalon M. 1140 (amine value ±8) in a weight ratio of 95:5
, 85:1575:25:65:3F was melt mixed at a ratio of 50:50 (roll edge kneading for 15 minutes at 150 qo), and then press-formed at 150 pm to have a skin thickness of 2.0 and a side thickness of 0.5. An adhesive sheet was obtained.

The resulting adhesive sheet was used as a supply for the next performance test. Performance test 1 2. A low-temperature verticalization test was performed on an adhesive sheet having the same thickness as in JIS K-6760 to determine the low-temperature verticalization temperature.

Performance test 22. JIS K-2 thick adhesive sheet
A ring and ball softening point test was conducted using No. 531 to determine the softening point of the adhesive.

Performance test 3 An adhesive sheet of 0.5 ribs is pasted on the inner surface of a heat-recoverable sleeve made of cross-linked polyethylene (inner diameter 600 mm, wall thickness 2.0 ribs), and this is attached to a cable sheath (material It was set on a polyethylene sheath, a vinyl chloride sheath, a lead sheath, an aluminum sheath), and heated and shrunk with a gas burner. After cooling, a notch in the IQ cape was inserted into a heat-recoverable sleeve and the peel strength with each sheath was determined.

As a typical example, aluminum sheath is -40q0,18
000 atmosphere was also tested.

The results of those performance tests are shown in Table 1.

Example 2 Dumilan C-2270 (hydrolysis rate 70%) was used as a hot-melt adhesive to be applied to the inner surface of a heat-recoverable article.
, unsaturated carboxylic acid content 1.5%) and Barsalon M.
1300 (amine value: 10) weight ratio: 95:5, 85
:15, 75:25, 65:35, and 50:50 were melt mixed (roll kneaded at 150 qo for 19 minutes), and then press-formed at 150°C to form a 2.0 leg and 0.5 rib thickness. An adhesive sheet was obtained. The obtained adhesive sheet is Example 1
A performance test similar to that was conducted to evaluate the performance. The results are shown in Table 2. Example 3 Dumilan C-1550 (hydrolysis rate: mainly 55%, unsaturated carboxylic acid content: 2.0%) and Barsalon C-1550 were used as hot-melt adhesives to be applied to the inner surface of heat-recoverable articles. 13 balls (amine value 6) weight ratio: 95:5, 85:15, 75:
25, 65:35, 50:50 ratios (150
The adhesive sheet was then press-formed at 150° C. to obtain an adhesive sheet with a thickness of 2.0 and a thickness of 0.5.

The obtained adhesive sheet 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 Evaflex No. 1 was used as a heat-melting adhesive for a secondary heat-recoverable article. 220 (Mitsui Polychemical Co., Ltd. ethylene vinyl acetate copolymer with a hydrolysis rate of 0%) and Barsalon rudder.
1165 (amine value ±1.5) was melt-mixed (roll foaming at 15 mm for 15 minutes) at a weight ratio of 70:3 to 30:70, and further press-molded at 150°C.2.
An adhesive sheet having a thickness of 0.5 ribs and a thickness of 0.5 ribs was obtained.

The obtained adhesive sheet was subjected to the same performance test as in Example 1 to evaluate its performance. The results are shown in Table 4. Comparative Example 2 Sumilink DR-56S (ethylene-vinyl acetate copolymer manufactured by Sumitomo Chemical Co., Ltd. with a hydrolysis rate of 100%) and Bar Salon Ship. 114
0 (amine value potato 8) in a weight ratio of 70:30, 30:7
Melt mixing at a ratio of 0 (roll kneading for 15 minutes at 150 qo)
2. An adhesive sheet having a thickness of Monosaki and a side thickness of 0.5 was obtained.

The obtained adhesive sheet was subjected to the same performance test as in Example 1 to evaluate its performance. The results are shown in Table 4. Table 1 Table 2 Table 3 Table 4 Tables 1, 2, and 3 show that the ethylene-vinyl acetate copolymer of the present invention has a hydrolysis rate of 50 to 90%, as can be seen from the performance test results. A heat-recoverable article using a hot-melt adhesive made of a polyamide resin having an amine value of 3 to 30 has a low low-temperature warping temperature and has excellent adhesive strength to various adherends.

Among them, ethylene vinyl acetate copolymer with a hydrolysis rate of 50 to 90% and polyamide resin with an amine value of 3 to 30 are used.
Adhesive formulations mixed in weight proportions ranging from 0:10 to 60:40 are particularly good in adhesive properties. 95:
Those with a blending ratio of 50:5 have a slightly higher softening point and require heating the heat-recoverable article to a high temperature and bonding at a high temperature;
It was found that the sample No. 50 had a low-temperature arming temperature of -40° C. or higher, and had poor cold resistance.

Furthermore, as can be seen from the results in Table 4, in the conventional mixture of ethylene vinyl acetate copolymer and polyamide resin,
It was found that it was not practical because it had poor low-temperature curing properties and a high softening point, making it impossible to obtain sufficient adhesive strength with various adherends.

From the above results, it was found that the product is made by mixing an ethylene vinyl acetate copolymer with a hydrolysis rate of 50 to 9% by weight and a polyamide resin with an amine value of 3 to 30 in a weight ratio ranging from 90:10 to 60:40. Heat-melting adhesives have excellent low-temperature properties and adhesive strength at high temperatures, and can universally adhere to various objects. The reversible article is capable of reliably coating and sealing objects made of various materials.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of a heat-recoverable article, in which 1 shows a heat-recoverable tube made of a crosslinked polyolefin resin, and 2 shows a hot-melt adhesive. car diagram

Claims (1)

[Scope of Claims] 1. Ethylene vinyl acetate copolymer having a hydrolysis rate of 50 to 90% by weight and polyamide resin having an amine value of 3 to 30 in a ratio of 90:1 to a necessary portion of at least one side of a heat-recoverable rubber or plastic layer. 1. A heat-recoverable article comprising a layer of a hot-melt adhesive mixed in a weight ratio of 60:40 to 60:40. 2. The heat-recoverable article according to claim 1, wherein the ethylene vinyl acetate copolymer is graft-polymerized with 0.1 to 5.0% by weight of an unsaturated carboxylic acid.