KR20230067771A - Industrial cable with high heat resistance and high flexibility and no blooming - Google Patents

Abstract

The present invention relates to 100 parts by weight of a base resin composed of 30 to 40% by weight of an ethylene propylene diene monomer (EPDM) to which no crosslinking agent is added, 30 to 50% by weight of an ethylene vinyl acetate resin, and 20 to 40% by weight of a polyolefin elastomer: flame retardant It relates to an industrial cable comprising 50 to 78 parts by weight, 1 to 5 parts by weight of a crosslinking agent and 1 to 5 parts by weight of an antioxidant, and the industrial cable according to the present invention is flexible including high flexibility at room temperature and high flexibility at low temperature. It has excellent heat resistance and high flame retardance that can withstand high temperatures, and can prevent problems with quality degradation by preventing blooming and bleeding phenomena that tend to occur on the surface due to chronic problems of products containing irradiation crosslinking agents.

Description

Industrial cable with high heat resistance and high flexibility and no blooming

The present invention relates to an industrial cable that has high heat resistance and high flexibility and does not generate a blooming phenomenon. It is about an industrial cable that can be secured and used for various purposes.

In the automobile industry, the weight of vehicles is continuously increasing due to the strengthening of safety regulations and the increase in convenience specifications, and accordingly, the weight of electric parts is required. When the high-voltage cable of an eco-friendly vehicle is added, the weight of the electric wire is further increased, so the performance improvement and weight reduction of the automotive cable are further demanded. In addition, various functions such as flexibility, heat resistance, insulation, and flame retardancy are required as well as light weight.

Existing thermoplastic elastomer (TPE) materials have excellent flexibility, but have a disadvantage in that flame retardancy and heat resistance are not high. Among them, ethylene-propylene rubber (Ethylene Propylene Diene terpolymer, hereinafter referred to as '') was used as the main base resin.

The EPDM is a polymeric material that has a certain amount of unsaturated diene units and is composed of ethylene and propylene as repeating units and has no polar group, so it has excellent insulation performance and exhibits excellent oxidation resistance and ozone resistance. EPDM rubber is cost-effective compared to many other elastomers, can contain high concentrations of fillers and oils, and has excellent physical properties. For this reason, EPDM can have heat resistance, flexibility, and flame retardancy by blending other elastomers or additives.

Looking at the prior art of using such an EPDM rubber in a cable, in Korean Patent Registration 10-0635586, 40 parts by weight to 80 parts by weight of an ethylene vinyl acetate copolymer (EVA) and 10 parts by weight to 50 parts by weight of an ethylene propylene diene (EPDM) copolymer 30 parts by weight to 170 parts by weight of a flame retardant based on 100 parts by weight of a base resin composed of a mixture of 5 parts by weight to 20 parts by weight of part and modified ethylene vinyl acetate (EVA), and the ethylene vinyl acetate copolymer contains 10 parts by weight of vinyl acetate % to 40% by weight, the ethylene propylene diene copolymer has 40% to 85% by weight of ethylene and 0.5% to 7.5% by weight of diene, and the modified ethylene vinyl acetate copolymer has vinyl acetate 10% to 30% by weight and a flame retardant and internal cut-through resin composition characterized in that a polar group is introduced at the terminal group.

In addition, Korean Patent No. 10-1918755 contains EPDM (Ethylene Propylene Diene Monomer) 30~80phr without crosslinking agent, PO (Polyolefine) resin 10~50phr, silicone rubber 5~40phr, flame retardant 20~30phr, crosslinking accelerator 5~10phr , 1 to 5 phr cross-linking aid, 5 to 15 phr antioxidant, and 0.25 to 5 phr lubricant. ~65, hardness shore A of 59 to 90, TR-10 of -10 to -12, among those satisfying the requirements, alone or in combination of two, the PO resin is a partially crosslinked modified PO and EPR (Ethylene-Propylene Rubber) are mixed, and the flame retardant is a mixture of Al(OH)3 and Mg(OH)2 alone or two among those whose surface is coated with silane, or a Br-based An irradiation crosslinking EPDM composition characterized as a flame retardant is presented.

In the case of electric wires using existing EPDM rubber, chemical crosslinking was often used, which caused methane gas to be generated, which had an adverse effect on the environment. , the problem of quality degradation due to cross-linking by-products could also be solved.

However, as in the above patent, when blending TPE material with elastomer and additives, the solid or liquid additives have limited solubility in the polymer matrix depending on the surrounding environment (temperature and humidity, etc.) or when irradiated crosslinking agents are included. As a phenomenon caused by the migration of the surface, a blooming phenomenon in which the compounding agent permeates the rubber surface and draws a flower-shaped pattern; Alternatively, there is a problem in which a bleeding phenomenon occurs due to material separation of some additives that float to the top. Some Blooming and Bleeding phenomena occur on purpose to protect rubber in foreign countries in special cases, but usually the aesthetics are not good and there is a high possibility of quality degradation, so development to prevent them is necessary.

In addition, the existing 125℃ heat resistance grade lacks heat resistance, so it is necessary to have characteristics higher than 150℃ grade and to secure heat resistance of -40℃ to 150℃ for use in extremely cold regions. In particular, cables located in the engine part of automobiles are exposed to adverse physical or chemical conditions such as high temperature, oil, vibration, and confined spaces, so high heat resistance and high flexibility are required, but the development of wires that meet these requirements is still insufficient. am.

In addition, fire retardancy and smoke density tests are required due to the risk of human life and property damage due to fire, and it is necessary to develop a wire having high retardance as well as securing heat resistance for these tests.

Korean Registered Patent 10-0635586 Korean Registered Patent No. 10-1918755

Accordingly, an object of the present invention is to provide an industrial cable having high heat resistance, high ductility, and high ductility that can be used throughout the industry as well as automobiles and does not cause blooming or bleeding.

The industrial cable according to the present invention contains 100 parts by weight of a base resin composed of 30 to 40% by weight of an ethylene propylene diene monomer (EPDM) to which no crosslinking agent is added, 30 to 50% by weight of an ethylene vinyl acetate resin, and 20 to 40% by weight of a polyolefin elastomer Regarding: 50 to 78 parts by weight of a flame retardant, 1 to 5 parts by weight of a crosslinking agent, and 1 to 5 parts by weight of an antioxidant.

According to one embodiment of the present invention, the ethylene propylene diene monomer (EPDM) to which the crosslinking agent is not added preferably has a Mooney Viscosity value of 60 to 80.

According to one embodiment of the present invention, the content of vinyl acetate in the ethylene vinyl acetate resin is preferably 40 to 70% by weight.

In addition, the flame retardant of the present invention is selected from silane-coated aluminum hydroxide (Al(OH) ₃ , S-ATH) or silane-coated magnesium hydroxide (Mg(OH) ₃ , S-MDH) It may be used alone or in combination.

According to one embodiment of the present invention, the crosslinking agent is triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), trimethylolpropane trimethacrylate (Trimethylolpropane Trimethacrylate, TMPTMA) , and trimethylolpropane triacrylate (Trimethylolpropane Triacrylate, TMPTA).

The industrial cable according to the present invention has excellent flexibility including high flexibility at room temperature and low temperature, high heat resistance and high retardance that can withstand high temperatures, and is easy to occur on the surface due to chronic problems of products containing irradiated crosslinking agents. Blooming and bleeding can be prevented to prevent problems with quality deterioration.

Therefore, since the industrial cable according to the present invention is exposed to adverse physical or chemical conditions such as high temperature, oil, vibration, and confined space, it is used not only for cables for automobile engines requiring high heat resistance and high flexibility, but also for agricultural tools and charging cables. It can be used for various purposes such as , high voltage cable, and battery cable.

Hereinafter, the present invention will be described in more detail.

Terms used in this specification are used to describe specific embodiments and are not intended to limit the present invention.

As used herein, the singular form may include the plural form unless the context clearly indicates otherwise. Also, when used herein, "comprise" and/or "comprising" specifies the presence of the recited shapes, numbers, steps, operations, elements, elements, and/or groups thereof. and does not exclude the presence or addition of one or more other shapes, numbers, operations, elements, elements and/or groups.

The present invention relates to an industrial cable that has high heat resistance, high flexibility, and high ductility and does not cause blooming, and contains 30 to 40% by weight of ethylene propylene diene monomer (EPDM) without a crosslinking agent and 30 to 50% ethylene vinyl acetate resin. It is characterized in that it comprises 50 to 78 parts by weight of a flame retardant, 1 to 5 parts by weight of a crosslinking agent, and 1 to 5 parts by weight of an antioxidant based on 100 parts by weight of a base resin composed of 20 to 40% by weight and 20 to 40% by weight of a polyolefin elastomer.

The base resin according to the present invention is preferably composed of 30 to 40% by weight of ethylene propylene diene monomer (EPDM), 30 to 50% by weight of ethylene vinyl acetate resin, and 20 to 40% by weight of polyolefin elastomer.

The ethylene propylene diene monomer (EPDM) is not added with a crosslinking agent, is well suited for extrusion characteristics, and preferably has a Mooney Viscosity range of 60 to 80 in consideration of other physical characteristics.

The ethylene propylene diene monomer is preferably included in an amount of 30 to 40% by weight in the total base resin, and when the content is less than 30% by weight, the hardness increases and flexibility is reduced, and when the content exceeds 40% by weight, extrusion processability is increased. It is not good, and it is not desirable because there is a problem that can affect the occurrence of blooming.

In addition, the ethylene vinyl acetate resin included in the base resin is that the content of vinyl acetate in the resin is 40 to 70% by weight, and when the content of vinyl acetate is less than 40% by weight, the hardness increases and the flexibility decreases, and also 70% If it is exceeded, physical and electrical properties (volume resistance) are deteriorated and the appearance state is not smooth, which is undesirable.

The ethylene vinyl acetate resin is preferably included in an amount of 30 to 50% by weight in the total base resin, and if it is less than 30% by weight, the exterior surface is not smooth, and if it exceeds 50% by weight, physical and electrical properties are deteriorated. It is not desirable to have

The base resin of the present invention contains 20 to 40% by weight of polyolefin elastomer, and when it is less than 20% by weight of the total base resin, physical properties are lower, and when it exceeds 40% by weight, there are problems in heat resistance and extrusion processability, which is preferable. can't

The industrial cable according to the present invention includes 50 to 78 parts by weight of a flame retardant, 1 to 5 parts by weight of a crosslinking agent, and 1 to 5 parts by weight of an antioxidant based on 100 parts by weight of the base resin.

The flame retardant may be used alone or in combination with silane-coated aluminum hydroxide (Al(OH) ₃ , S-ATH) and silane-coated magnesium hydroxide (Mg(OH) ₃ , S-MDH). It may be included in 50 to 78 parts by weight based on 100 parts by weight of the base resin. When the flame retardant content is included in 50 to 78 parts by weight based on 100 parts by weight of the base resin, it is preferable in terms of securing flame retardancy and maintaining physical properties. However, in the case of using a fatty acid magnesium flame retardant as the flame retardant, blooming phenomenon may occur in the immersion test, so care needs to be taken.

The crosslinking agent according to the present invention is triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), trimethylolpropane trimethacrylate (TMPTMA), and trimethylolpropane At least one selected from trimethylolpropane triacrylate (TMPTA) may be used, and triallyl isocyanurate (TAIC) may be most preferably used. In the case of the crosslinking agent, as a multifunctional monomer, in the crosslinking process using an electron beam, the crosslinking reaction can proceed even at a low electron beam intensity, so it can be preferably used. The crosslinking agent is preferably included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the base resin for proper crosslinking.

In addition, the antioxidant is one or more selected from phenol-based, phosphorus-based, amine-based, and triazole-based, and is preferably included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the base resin for proper antioxidant function.

It is apparent to those skilled in the art that the industrial cable according to the present invention may additionally include conventional additives such as crosslinking accelerators and lubricants included in conventional cable compositions in addition to the components listed above, as necessary.

The manufacturing process of the industrial cable according to the present invention is described as follows.

First, preparing a composition containing each of the components listed above and primary kneading by a kneading machine, extruding the primary kneaded composition with an extruder and then cutting to prepare a raw material in the form of a pellet, It can be produced by extruding a raw material in the form of pellets into a cable having an arbitrary set length using an extruder, and crosslinking the cable with an electron beam accelerator.

Hereinafter, preferred embodiments of the present invention will be described in detail. The following examples are only for illustrating the present invention, and the scope of the present invention should not be construed as being limited by these examples. In addition, in the following examples, specific compounds were exemplified, but it is obvious to those skilled in the art that equivalent or similar effects can be exerted even when equivalents thereof are used.

Examples 1 to 2 and Comparative Examples 1 to 5

Components according to each composition according to the following Table 1 were put into a kneader and first kneaded to prepare a uniformly mixed mixture. The firstly kneaded mixture was put into an extruder and extruded, and then the cooled extrudate was cut into a predetermined size to make a raw material in the form of a pellet. The raw material in the form of pellets was extruded into a cable having an arbitrary set length using an extruder for electric wires. Finally, each cable was cross-linked with an electron beam accelerator to obtain a final predetermined cable.

Content (parts by weight) comparative example Example One 2 3 4 5 One 2 Base resin EPDM ⁽¹⁾ 80 60 30 30 30 30 30 EVA
(VA content 10-30% by weight) - 20 45 - - - - EVA
(VA content 40-70% by weight) - - - 45 - 45 45 EVA
(VA content exceeds 70 weight) - - - - 45 - - POE 15 20 25 25 25 25 25 silicone rubber 5 - - - - - - flame retardant S-ATH ⁽²⁾ - 50 75 50 75 50 75 S-MDH ⁽³⁾ 30 - - - - 25 - Fatty Acid Coated MDH - 30 - 25 - - - additive Antioxidants ⁽⁴⁾ 2 2 2 2 2 2 2 Irradiation crosslinking agent ⁽⁵⁾ 2 2 2 2 2 2 2 (main)
(1) EPDM: A crosslinking agent with a Mooney viscosity of 60 is not added.
(2)S-ATH: aluminum hydroxide whose surface is coated with silane
(3) S-MDH: Magnesium hydroxide with silane coating on the surface
(4) Antioxidant: phenolic
(5) Irradiated crosslinking agent: triallyl isocyanurate (TAIC)

Experimental example

The physical properties of each cable manufactured according to the above Examples and Comparative Examples were measured as follows, and the results are shown in Table 2 below.

1. General conditions

1.1 Standard laboratory conditions are temperature 23 ± 2 ℃, relative humidity 50 ± 5%.

1.2 The test piece is used after 48 hours of manufacture and left for more than 24 hours in the laboratory standard condition.

2. Specific Gravity

Follow the method specified in ISO 1183, Method A, 23℃.

3. Room temperature properties

Tensile strength and elongation are tested according to the method of IEC 60811-501.

4. Hardness

Follow the method specified in ISO 868. Room temperature flexibility can be judged.

5. Heat resistance properties (tensile and elongation after aging)

Room temperature tensile strength and elongation are measured according to IEC 60811-501. Tensile strength and elongation after the test are measured under aging conditions of 150℃*168HR, 175℃*240HR, and 180℃*168HR to determine tensile and elongation residual rates, cracks, etc.

6. Oil resistance test (tensile and elongation after oil resistance)

Tensile strength and elongation are measured after immersion at 50℃ for 10 hours with No. 1 lubricating oil specified in KS M 2121 and oil specified in KS M 2613.

7. MI (Melt flow index): Extrusion processability

Measure the value representing the amount of extrusion (unit of weight/unit of time) given a pressure of 10Kg at 170°C.

8. Oxygen Index (LOI)

Follow the method specified in ISO 4589-2. (The test piece uses a heated compression sheet.)

9. Flame retardant

9-1. Flame retardancy (material, compound)

According to KS M ISO 4589-2, the shape of the test piece (length 80 ~ 150mm, width 6.5mm, thickness 3mm) is manufactured and tested.

9-2. Flame retardant (cable)

(1) Take a sample of 300mm length and support it horizontally in the flame retardant tester.

The front end of the reducing salt adjusted to the length of the oxidation salt of the flame is about 130mm and the length of the reducing salt is about 35mm is applied from the bottom of the center of the sample for 10 seconds, then the flame is removed and the burning time of the sample is measured.

(2) The sample consists of 3.5m cable test pieces, and the number of test pieces should be suitable for the volume of 1.5L/m of non-metallic material.

Each test piece is mounted in the test facility of IEC 60332-3-10 and the flame is applied for 20 minutes.

The maximum degree of carbonization rate measured in the sample should not exceed 2.5m in height from the bottom corner.

10. Combustibility

Follow the method specified in MS300-08 (Standard Test Method - Combustibility of Interior Materials). (The test piece uses a heated compression sheet.)

11. Heat Deformation Test

After heating the test piece to 120 ° C with a heating strain tester, measure the thickness of the test piece after applying a load of 9.8 N for 1 hour.

Heating strain: D = (t1 - t2) / t1 X 100, t1: thickness before heating (mm), t2: thickness after heating (mm)

12. Cold resistance test

Cold resistance tester: It consists of test piece tongs and a striking mechanism, and the striking mechanism rotates at a constant linear speed of 1.97m/s to strike the test piece.

Test method: Put the test piece in the tongs under the measured temperature condition, leave it for 3 minutes, then hit it, and all 3 pieces must not be destroyed. Low-temperature flexibility can be judged by the measured value of cold resistance.

13. Volume Resistance

After heating the test piece in a chamber at 30 ° C for 1 hour, a direct current of 500 V is applied for 1 minute to measure the volume resistance.

14. Smoke density test

The smoke density test follows the ASTM E662-21 test.

(1) Workplaces with high risk of human life and property damage require 200DS or less, and industrial and business workplaces require 450DS or less.

15. Flexibility (flexibility) test (Cable)

The bending (flexibility) test follows the IEC-60227-2 test.

(1) After 15,000 times and 30,000 times of bending, there should be no current cut off or short circuit between conductors, and it should pass the withstand voltage test.

16. Blooming test

Conforms to the bleaching test according to ES91900-00.

(1) Immersion test: After immersing in distilled water at 80℃ for 7 days, check whether whitening occurs

(2) Wet test: After leaving it for 30 days in an environment of 80℃ and 95% humidity, check whether whitening occurs

(3) Dry test: After leaving for 30 days in an environment of 80℃ and humidity of 10% or less, check whether whitening occurs

Properties comparative example Example One 2 3 4 One 2 2 Specific Gravity (g/cm) 1.09 1.25 1.25 5 1.24 1.25 1.24 Room temperature tensile strength (kgf/㎠) 1.97 1.82 1.16 1.02 1.32 1.4 1.35 Room temperature elongation (%) 650 340 343 476 391 292 350 Hardness (Shore A) 61 70 80 70 70 70 70 Tensile residual after aging (%)
(175℃ x 240HR) 83 106 85 79 40 80 80 Kidney residual rate after aging (%)
(175℃ x 240HR) 84 96 65 60 50 68 75 Tensile residual rate after oil proofing (%)
(50℃ x 10HR) 95 88 90 89 97 94 96 Kidney residual rate after lactation (%)
(50℃ x 10HR) 88 85 91 89 85 87 88 MI (170℃, 10KG) (g/10min) 0.5 0.7 2.3 2.3 2.3 2.3 3.1 LOI (%) 24 26 25 25 26 26 27 flame retardancy test
(Extinguishing within 10 seconds) FAIL PASS PASS PASS PASS PASS PASS Combustibility test (self-extinguishing) PASS PASS PASS PASS PASS PASS PASS Heat deformation test (%)
(120℃, 1HR, 9.8N) 5 5 7 6 5 5 5 Cold resistance test (℃) -60 -50 -60 -60 -60 -60 -60 Volume Resistance (Ω x Cm) 5 x 10 ¹⁵ 2 x 10 ¹⁵ 5 x 10 ¹⁴ 9 x 10 ¹⁵ 1 x 10 ¹² 7.8 x 10 ¹⁵ 3 x 10 ¹⁵ Smoke Density Test (DS Max) 85 75 70 75 71 72 70 Flexibility (bending) test
(withstand voltage test) PASS PASS FAIL PASS PASS PASS PASS Appearance condition Good Good Good Good error Good Good Blooming
test
(whether it occurs) left at room temperature O X X X X X X deflation
(80℃ x 30 days) △ X X X X X X Wet (80℃, humidity 95% x 30 days) O X X X X X X Immersion (80 ℃,
Tap water immersion x 7 days) O O X O X X X

Referring to the results of Table 2, Experimental Example 1 is a cable manufactured with the composition according to Patent Document 1, and has excellent flexibility and high heat resistance, but poor flame retardancy, and M.I. As the value is 0.5, it can be seen that the extrusion processability is not good and the blooming phenomenon occurs (○).

In addition, in the case of Comparative Example 2 using a combination of EVA and POE instead of reducing the EPDM content by changing the combination of the base resin and using fatty acid-coated MDH in addition to S-ATH according to the present invention as a flame retardant, M.I. Although the extrusion processability was improved with a value of 0.7, whitening was observed in the blooming immersion test.

In the case of Comparative Example 3, as in the present invention, the composition was changed so that EPDM, EVA (VA content of 10 to 30% by weight), and POE were all included as the base resin, and the flame retardant also fell within the scope of the present invention, so that the blooming phenomenon did not occur. and M.I. Although the value was 2.3, the extrusion processability was good, but the hardness increased and the flexibility was poor when the EVA VA content (10 to 30% by weight) was lower than that of Examples 1 and 2 (40 to 70% by weight).

In the case of Comparative Example 4, as in Examples 1 and 2, extrusion processability and flexibility were good by changing the combination of the base resin, but blooming occurred in the immersion test as a result of using MDH coated with fatty acids by changing the combination of flame retardants.

In the case of Comparative Example 5, as in the present invention, the base resin includes all of EPDM, EVA (VA content of 70 to 80%), and POE, and the flame retardant is also changed to fall within the scope of the present invention, so that the blooming phenomenon does not occur. , M.I. Although the value was 2.3, the extrusion processability was good, but the EVA VA content (more than 70% by weight) was higher than Examples 1 and 2 (40 to 70% by weight), so the appearance was poor, and the electrical properties (volume resistance), heat resistance It can be seen that it is not good in

From the above results, it was possible to solve the workability or blooming phenomenon depending on the composition of the base resin or the combination of flame retardants used in cable manufacturing. It was confirmed that the workability is good and there is no blooming, and the blooming phenomenon can be suppressed when the content of vinyl acetate in the ethylene vinyl acetate resin is used at 40 to 70% by weight.

Claims (5)

With respect to 100 parts by weight of a base resin composed of 30 to 40% by weight of ethylene propylene diene monomer (EPDM) to which no crosslinking agent is added, 30 to 50% by weight of ethylene vinyl acetate resin, and 20 to 40% by weight of polyolefin elastomer:
50 to 78 parts by weight of a flame retardant;
1 to 5 parts by weight of a crosslinking agent and
An industrial cable comprising 1 to 5 parts by weight of an antioxidant.
According to claim 1,
An ethylene propylene diene monomer (EPDM) to which the crosslinking agent is not added has an industrial cable having a Mooney Viscosity value of 60 to 80.
According to claim 1,
The ethylene vinyl acetate resin is an industrial cable in which the content of vinyl acetate in the resin is 40 to 70% by weight.
According to claim 1,
The flame retardant is selected from silane-coated aluminum hydroxide (Al(OH) ₃ , S-ATH) and silane-coated magnesium hydroxide (Mg(OH) ₃ , S-MDH) alone or in combination. Industrial cable that is to do.
According to claim 1,
The crosslinking agent is triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), trimethylolpropane trimethacrylate (TMPTMA), and trimethylolpropane triacrylate ( At least one industrial cable selected from Trimethylolpropane Triacrylate, TMPTA).