JPS60264228A - Heat-recoverable article - Google Patents

Abstract

PURPOSE:To make the titled article maintain excellent low-temperature impact resistance and high-temperature adhesion properties, by a method wherein a specific ethylene copolymer and specific polyamide resin are mixed at a predetermined ratio with each other and a reacion inhibitor of acid and amine are loaded as a heat-meltable adhesive to be applied to a heat-recoverable article. CONSTITUTION:An ethylene-vinyl acetate copolymer whose hydrolytic factor is 50-90wt% and polyamide resin whose amin valence is 0.5-3.0 are mixed on a necessary part of at least one side of a heat-recoverable rubber or plastic layer so that a mixture ratio falls within a range of 90:10 or 60:40 by a weight proportion. In addition to the above, the above is made into a heat-meltable adhesive by loading and mixing first class or second class fatty or aromatic amine group at a rate of 0.1-5.0pt.wt. 100pt.wt. As this layer is provided, and article, which is superior in conservation stability, is obtained without generating an aging variation under a high-temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 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.

[Background of the invention]

Heat-recoverable sleeves with heat-melting adhesive coated on the inner surface are used for the connections and terminals of power cables, communication cables, steel pipes, and steel pipes, etc., which require properties such as insulation, water resistance, and sealing properties. , heat-recoverable articles such as terminal caps are widely used.

However, the hot-melt adhesives currently used for heat-recoverable articles are compatible with various materials used for the above-mentioned connections and terminals, such as metals such as iron, copper, lead, aluminum, and stainless steel, polyethylene, polypropylene, etc. 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 adhesion between polyolefin resins such as polyethylene and polypropylene and metals such as copper, iron and aluminum, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ionomer resin, ethylene glycidyl methacrylate copolymer, ethylene glycidyl methacrylate-hinyl acetate ternary copolymer are used. , ethylene acrylic acid-acrylic ester ternary copolymers obtained by hydrolyzing or thermally decomposing ethylene 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 shear adhesive 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, it will crack or peel at the bonded part, making it impractical. However, in reality, various combinations of materials are used for the connections and terminals of power cables and communication cables, and heat-recoverable products are made of many types of plastic or rubber, such as polyolefin resin and polyvinyl chloride resin. Therefore, 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 pipes, etc., has recently changed from extremely low temperatures (about -40°C) to high temperatures (80°C).
Although there has been a demand for heat-recoverable articles coated with hot-melt adhesives that can withstand a wide temperature range up to 1000 degrees, there has not yet been a satisfactory product. In order to solve these problems, a hot-melt adhesive made by blending the above-mentioned ethylene-based adhesive and the latter polyamide-based adhesive was developed in JP-A-56.
-122880. This adhesive is a universal adhesive that exhibits adhesion to various adherends, but in order to exhibit its versatility, it was necessary to mix a specific ethylene resin and a specific polyamide resin.

As ethylene resin, hydrolysis rate is 50 to 90% by weight
An ethylene vinyl acetate copolymer having 0.1 to 5.0% by weight of unsaturated carboxylic acid is preferably graft-polymerized, and the polyamide resin has an amine value of 0.5.
~80 polyamide resins were preferred.

However, such hot-melt adhesives have -OH, -COOH, and -NHg groups, so when heated for a long time, these two react, raising the adhesive's softening point and viscosity. It was discovered that there was insufficient adhesive strength.

For this reason, it was found that when used at high temperatures, it gradually reacts and changes over time, and also has poor storage stability even at low temperatures.

[Summary of the invention]

The present invention can be applied to technical colleges without deteriorating the all-purpose adhesive properties. Heat 5- which does not change over time at room temperature and has excellent storage stability. A heat recoverable article coated with a melt adhesive is provided.

The adhesive according to the present invention is produced by mixing a specific ethylene copolymer and a specific polyamide resin in a predetermined ratio, and adding a reaction inhibitor that prevents the reaction between acid and amine.
This is the first hot-melt adhesive to be developed that maintains excellent low-temperature impact resistance and high-temperature adhesion. Specifically, ethylene vinyl acetate copolymer with a hydrolysis rate of 50 to 90% by weight and polyamide resin with an amine value of 8 to 80 are mixed in a ratio of 90:10 to 6.
It is a hot-melt adhesive made by mixing the two in a weight ratio of 0:40 and adding and mixing a -class or secondary aliphatic or aromatic amine.

[Detailed description of the invention]

As a hydrolyzate of ethylene vinyl acetate copolymer,
Various products 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 50 to 90% by weight. This is because if the vinyl acetate content is 45% by weight or more, the adhesion to polyolefin is poor, and the thermal stability and cold resistance are poor. Furthermore, if the thermal decomposition rate is less than 45% by weight, the melting point is low and the mechanical strength at high temperatures is low.
This is because if the content exceeds % by weight, low-temperature impact properties are poor and melt viscosity is high. More preferably, 0.1 to 5.0% by weight of unsaturated carboxylic acid is graft-polymerized after hydrolyzing the ethylene vinyl acetate copolymer, 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, D manufactured by Takeda Pharmaceutical Industries, Ltd.
-251°G-222, G-252, G-422, C-
2191, C-2271, C-1591, C-1570
, C-1580, C-1550, C-2280, etc. and Toyo Soda) Product name Mersen H-64, 10, H-681
0, H-6820, H-6822°H-6960, etc. can be used.

Furthermore, polyamide resins with an amine value of 0.5 to 30 are made by reacting dibasic acids called dimer acids with diamines, such as adipic acid, azelaic acid, and unsaturated fatty acids such as tall oil fatty acids and soybean oil fatty acids. Acid, heptapathic acid, etc. are added, and further ethylenediamine, hexamethylenediamine, influoronediamine, xylylenediamine, 4. -4'-diaminodicyclohexylmethane,
It is a polyamide resin made by reacting P-P'-methylene dianiline, piperazine, trimethylhexamethylene diamine, alkanolamine, etc. The obtained polyamide resin preferably has a number average molecular weight in the range of about 1,500 to 20,000 and a ring and ball softening point in the range of about 80°C to 200°C. In particular, in the present invention, those with an amine value of 0.5 to 80 are preferable; if the amine value is less than 0.5, 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 thermal deterioration occurs. This is because it is easily susceptible to adhesion and has poor compatibility with ethylene-vinyl acetate copolymers (resulting in a decrease in adhesive strength).

Examples of the -class or secondary aliphatic or aromatic amines used in the present invention include diethylenetriamine, triethylenetetramine, diethylaminoprobylamine, diamine diphenyl sulfone, N-di-l-lodgephenylamine, N-di- Examples include trosophenyl p-naphthylamine, sulfonamide derivatives, and the like. By adding 0.1 to 5.0 parts by weight of these amines, the reaction between the acid groups in the EVA resin and the amide groups in the polyamide is prevented,
Prevents increases in softening point and viscosity, ensuring long-term stability of adhesive strength. If the amount of the amine added is less than 0.1 parts by weight, the effect will not be sufficient, while if it is more than 5.0 parts by weight, the hot-melt adhesive will become embrittled at low temperature and the adhesive strength will decrease, which is not preferable.

The polyamide resin having an amine value of 0.5 to 30 of the present invention is manufactured by Henkel Japan and has a trade name of 1128゜13.
00, 1138. 1139. 1140. 1,1
64. 1165°1175, etc., product name Dormide 394, manufactured by Fuji Kasei Kogyo ■. 509.1310,535,
1850,512,565,500゜575.1360
．． etc. can be used.

Furthermore, the hot-melt adhesive used in the present invention includes rubber components such as styrene-butadiene block copolymer, styrene-isoprene block copolymer, natural rubber, butyl rubber, and a thickening agent as one of the few low-temperature modifiers. ! : It is also possible to add terpene resins, terpene phenol resins, phenol resins, alkylphenol resins, colorants, fillers, anti-aging agents, etc.

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 O-215 (hydrolysis rate: 80%) and Persalon A1140 (amine value: 8) were used as a hot-melt adhesive to be applied to the inner surface of a heat-recoverable article, and triethylenetetramine was used as an amine. The weight ratio is 90:10
:0.5.70:80:1.0.50 :50:3.0
Melt mixing (roll kneading for 15-10 minutes at 150'C) was carried out at a ratio of 2.0 m.
Adhesive sheets of yn thickness and 0.5 mm thickness were obtained. The obtained adhesive sheet was used as a sample for the next performance test.

Performance Test 1 A low temperature embrittlement test was conducted on a 2.0u thick adhesive sheet according to JIS K-6760 to determine the low temperature embrittlement temperature.

Performance test 2゜2, OvL thick adhesive sheet at 150℃ for 1 hour, 3 hours,
After heating for 5 hours and 10 hours, JISK-2581
A ring and ball softening point test was conducted to determine the softening point of the adhesive.

Performance test 8゜2, Oax thick adhesive sheet at 150℃ for 1 hour, 3 hours,
Heated for 5 hours, 10 hours, then JISK-6760
Melt index test was conducted by
The viscosity at 0°C was determined.

Performance test material: Adhesive sheet with a thickness of 0.5 mm was heated at 80℃ for 5 days, 10 days, and 20 days.
After storage for 30 days, the sleeve was pasted onto the inner surface of a heat-recoverable sleeve made of cross-linked polyethylene (inner diameter: 60mm wall thickness: 2.0μ), and this was attached to a cable sheath (made of vinyl chloride sheath, lead sheath) with an outer diameter of 45mm. ), heat-shrink it with a gas burner, and after cooling, wrap it in a heat-recoverable sleeve.
A notch with a width of 0 m was made to measure the peel strength with each sheath.

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

Example 2: Dumilan C-22'IO (hydrolysis rate: 70%, unsaturated carboxylic acid content: 1.5%) and Persalon Kiaoo as heat-melting adhesives applied to the inner surface of heat-recoverable articles
(amine value: 10), and using N-nitrosodiphenylamine as an amine, the weight ratio of each was 90%.
:10:0.5. '70:30:1.0,50:50:
Melt mixing (roll mixing at 150°C for 15 minutes) was performed at a ratio of 3.0, and press molding was performed at 150°C.2. Ou
Thickness and 0. ! An adhesive sheet having a thickness of M171L 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 2.

Example 3: Dumilan C-1550 (hydrolysis rate: 55%, unsaturated carboxylic acid content: 2.0%) and Persalon group 1358 (
amine value (kg) and metaphenylenediamine as the amine, in a weight ratio of 90:10:0, respectively.
．． 5. Perform melt mixing (roll mixing at 150°C for 15 minutes) at a ratio of 7010:1.0, 50:50:3.0, and press molding at 150°C.2. An adhesive sheet with a thickness of On and a 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 3.

Comparative Example 1 As a conventional heat-melting adhesive for heat-recoverable articles, Example 1
Using the EVA and polyamide resin used in 2., melt mixing (roll mixing at 150°C for 15 minutes) was performed in the same ratio without adding a reaction inhibitor, and press molding was performed at 150°C. An adhesive sheet having a thickness of O#IjlL and a thickness of 0.5 mm was obtained. The obtained adhesive sheet was used as Example 113-Comparative Example 2 as a heat-melting adhesive for conventional heat-recoverable articles.
Using the EVA resin and polyamide resin used in
2. Roll cross-circuiting) was carried out for 5 minutes, and further press molding was performed at 150°C. Adhesive sheets with OB thickness and 0.5B thickness were 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 5.

14- As can be seen from the performance test results in Tables 1, 2, and 8, the ethylene vinyl acetate copolymer of the present invention has a hydrolysis rate of 50 to 90% and the polyamide resin has an amine value of 0.5 to 80. Furthermore, heat-recoverable articles using hot-melt adhesives using primary or secondary aliphatic or aromatic amines have a low low-temperature embrittlement temperature and have excellent adhesive strength to various adherends. Among them, an ethylene vinyl acetate copolymer having a hydrolysis rate of 50 to 90% and a polyamide resin having an amine value of 8 to 30 are mixed in a weight ratio of 90:10 to 60:40, and further amines are mixed in a weight ratio of 0.1 to 5. Adhesive formulations added in a proportion of .0 parts by weight are particularly good in terms of adhesive properties.

On the other hand, as can be seen from the results in Tables 4 and 5, conventional mixtures of ethylene vinyl acetate copolymer and polyamide resin lack adhesive thermal stability and have poor storage stability. Adhesion strength decreases rapidly for various types of adhesion,
It turned out to be impractical.

〔Effect of the invention〕

20- From the above results, an ethylene vinyl acetate copolymer with a hydrolysis rate of 50 to 90% by weight and a polyamide resin with an amine value of 3 to 30 are mixed in a weight ratio of 90:10 to 60:40, and Hot-melt adhesives containing 0.1 to 5.0 parts by weight of -class or secondary aliphatic or aromatic amines have excellent low-temperature embrittlement resistance and stable adhesive strength when held at high temperatures. Since it has excellent universal adhesion to various adherends, the heat-recoverable article of the present invention coated with the adhesive can reliably cover and seal objects made of various materials. It is.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an example of a heat-recoverable article, in which (1) is a heat-recoverable tube made of crosslinked polyolefin resin, (2)
indicates a hot melt adhesive. 21-Mine One-time Procedure Amendment Written on July 4th, 1981, Case Description 1982 Patent Application No. 121063λ Name of Invention Heat Recoverable Article 3, Person Making the Amendment Relationship with the Case Patent Applicant Address: 5-15 Kitahama, Higashi-ku, Osaka Name (213)
) President Tetsu Kawakami Department 4, Sumitomo Electric Industries, Ltd. Address: Inside Sumitomo Electric Industries, Ltd., 1-1-3 Shimaya, Konohana-ku, Osaka (Telephone: Osaka 4F31-1031) 6. Patents pending in the specification subject to amendment Claims column and Detailed Description of the Invention column 7, Contents of amendment (0) Claims in the specification should be corrected as shown in the attached sheet. Insert the following sentence after "." [Furthermore, if metal and plastic are bonded together and then used under water, the adhesive strength at the interface will gradually decrease. (3) Page 5, line 20 of the specification, ``Excellent storage stability'' was changed to ``Excellent storage stability and excellent adhesive strength in water.''
Correct. (4) On page 9, line 4 of the specification, "adhesive strength" is corrected to "adhesive strength in water." (5) After "Excellent" on page 20, line 13 of the specification, [further, a test similar to that of the example was conducted by immersion in 80°C warm water,
As a result of measuring changes in adhesive strength over time, it was found that there was only a slight decrease in adhesive strength even after 2 to 30 days, indicating that the adhesive strength was excellent in water. ” Insert the text. 3- Claims [(1) The required portion of at least one side of the heat-recoverable rubber or plastic layer has a hydrolysis rate of 50 to 90%
Ethylene vinyl acetate copolymer and amine value of 0.5~
Mixing ratio of 30 to polyamide resin is 00:1 by weight
Furthermore, primary or secondary aliphatic or aromatic amines are added in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the total amount of the ethylene vinyl acetate copolymer and polyamide. 1. A heat-recoverable article characterized in that it is provided with scraps of a hot-melt adhesive mixed in a proportion. (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. ” 153-

Claims (2)

[Claims] (1) A necessary portion of at least one side of the heat-recoverable rubber or plastic layer is coated with an ethylene vinyl acetate copolymer having a hydrolysis rate of 50 to 90% by weight and an amine value of 0.5 to 3.
．． The mixing ratio with polyamide resin of 0 is 90:1 by weight.
Furthermore, a primary or secondary aliphatic or aromatic amine [-0.1 to 5.0 parts by weight based on the total amount of the ethylene vinyl acetate copolymer and polyamide ioo parts by weight] 1. A heat-recoverable article comprising a layer of hot-melt adhesive mixed in the same proportions. (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.