KR102484826B1 - Fiber reinforced resin composition having excellent internal tearing strength and low-temperature resistance - Google Patents

Abstract

The present invention relates to a fiber-reinforced resin composition having excellent tear strength and cold resistance. Specifically, the present invention relates to a fiber-reinforced resin composition capable of maintaining cold resistance, laying ability, etc., which are in a conflicting relationship with each other, even though mechanical properties such as tensile strength, tear strength, and modulus are improved.

Description

Fiber reinforced resin composition having excellent internal tearing strength and low-temperature resistance}

The present invention relates to a fiber-reinforced resin composition having excellent tear strength and cold resistance. Specifically, the present invention relates to a fiber-reinforced resin composition capable of maintaining cold resistance, laying ability, etc., which are in a conflicting relationship with each other, even though mechanical properties such as tensile strength, tear strength, and modulus are improved.

The resin composition constituting the sheath layer of cables such as mining cables and moving cables used under harsh environments, automobile tubes, and tires must have excellent mechanical properties such as tensile strength, tear strength, and modulus, and also High cold resistance and laying ability, which are in a trade-off with this, must also be excellent, and in particular, when used in special environments such as polar regions, cold resistance of -50 ° C or less is required.

A conventional resin composition used for the above purpose further includes silica to improve mechanical properties such as high tensile strength, tear hardness, and modulus, while further including a plasticizer to improve high cold resistance. However, since the mechanical properties and the cold resistance are in conflict with each other, it has been difficult to set an appropriate composition ratio of silica, plasticizer, and the like.

Specifically, when the content of silica included to improve the mechanical properties is increased, flexibility, cold resistance, etc. of the resin composition may be significantly reduced, whereas when the content of the plasticizer included to improve the cold resistance is increased The mechanical properties of the resin composition tend to deteriorate.

In addition, the conventional resin composition has mechanical properties and cold resistance at the same time by including chlorinated polyethylene (CPE), chloroprene rubber (CR), polyolefin elastomer (POE), etc. as a base resin constituting the blended mixture. However, there is a limit in that the heat resistance, oil resistance, compatibility, and abrasion resistance of the resin composition are lowered.

1 and 2 schematically show cross-section and longitudinal-section structures of a cable for a conventional mine, respectively.

As shown in FIGS. 1 and 2, in the conventional mine cable 100, one or more cores 10 made of a conductor 11 and an insulator 12 surrounding it are wrapped by a bedding 20, and a metal braided layer (30) and the sheath layer (40) are sequentially arranged.

Here, in order to compensate for insufficient mechanical properties of the resin composition constituting the sheath layer 40, the metal braided layer 30 disposed between the bedding 20 and the sheath layer 40 is The adhesive force between the sheath layer 40 is lowered so that the bedding 20 and the sheath layer 40 can be separated when the cable 100 is twisted, and the bedding 20 and the sheath layer 40 can be separated. Since each has to be extruded, there is a problem in complicating the manufacturing process of the cable 100 and increasing the manufacturing cost of the cable 100.

Therefore, despite the improvement in mechanical properties such as tensile strength, tear strength, and modulus, there is an urgent need for a sheath layer of a cable or a resin composition for bedding that can maintain cold resistance and laying performance, which are in a conflicting relationship therewith, without deterioration. It is becoming.

An object of the present invention is to provide a fiber-reinforced resin composition having excellent mechanical properties such as tensile strength, tear strength, and modulus.

In addition, an object of the present invention is to provide a fiber-reinforced resin composition excellent in cold resistance, laying ability, etc., which is in a conflicting relationship with the mechanical properties.

In order to solve the above problems, the present invention,

A fiber-reinforced resin composition comprising a base resin and synthetic fibers, wherein the base resin includes chlorinated polyethylene (CPE), chloroprene rubber (CR), or a combination thereof, and the synthetic fibers are aramid fibers having a length of 3 mm or less It provides a fiber-reinforced resin composition comprising.

Here, the content of the aramid fibers provides a fiber-reinforced resin composition, characterized in that 1 to 20 parts by weight based on 100 parts by weight of the base resin.

In addition, it provides a fiber-reinforced resin composition, characterized in that the diameter of the aramid fibers is 10 to 100 ㎛.

And, it provides a fiber-reinforced resin composition, characterized in that the chlorine (Cl) content of the chlorinated polyethylene (CPE) is 30 to 40% by weight.

Here, the chlorinated polyethylene (CPE) provides a fiber-reinforced resin composition, characterized in that the Mooney viscosity at 121 ° C. is 60 to 120 MU.

In addition, the base resin further comprises a polyolefin elastomer (POE), based on 100 parts by weight of the base resin, the content of the polyolefin elastomer (POE) is 0 to 50 parts by weight, characterized in that, a fiber-reinforced resin composition to provide.

And, it provides a fiber-reinforced resin composition comprising at least one additive selected from the group consisting of a stabilizer, a filler, a plasticizer, a crosslinking agent, a flame retardant, an antioxidant and a processing aid.

Here, the filler provides a fiber-reinforced resin composition, characterized in that it comprises 0 to 50 parts by weight of silica based on 100 parts by weight of the base resin.

On the other hand, one or more cores including a conductor and an insulator surrounding the conductor, a bedding entirely surrounding the core, and a sheath layer surrounding the bedding, wherein the bedding, the sheath layer, or both of claims 1 or 2 A cable formed from the fiber-reinforced resin composition of claim is provided.

The fiber-reinforced resin composition according to the present invention has an excellent effect of simultaneously improving mechanical properties such as tensile strength, tear strength, modulus, and the like, and cold resistance and laying ability, which are in conflict with each other, by a specific base resin, additives, and specific synthetic fibers. indicate

1 schematically illustrates the cross-sectional structure of a conventional mining cable.
2 schematically illustrates a longitudinal cross-sectional structure of a conventional mining cable.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content will be thorough and complete, and the spirit of the present invention will be sufficiently conveyed to those skilled in the art. Like reference numbers indicate like elements throughout the specification.

The present invention relates to a fiber-reinforced resin composition having excellent mechanical properties such as tensile strength, tear strength, and modulus, as well as excellent cold resistance and laying properties, which are in conflict therewith.

The fiber-reinforced resin composition according to the present invention may include a base resin, aramid fibers and other additives.

The base resin may include chlorinated polyethylene (CPE) and/or chloroprene rubber (CR), and may further include polyolefin elastomer (POE). Here, the chlorinated polyethylene (CPE) may be prepared by chlorination of polyethylene (PE).

Since the chlorinated polyethylene (CPE) is softer than polyethylene itself when the chlorine (Cl) content is less than 30% by weight and exhibits a rubbery state, the chlorine (Cl) content is 30% by weight or more, e.g. For example, it may be 30 to 40% by weight.

In addition, the chlorinated polyethylene (CPE) may have a Mooney viscosity of 60 to 120 MU at 121 ° C. When the Mooney viscosity of the chlorinated polyethylene (CPE) is less than 60, mechanical properties of the resin composition may be insufficient, whereas when it is greater than 120, flexibility, cold resistance, etc. of the resin composition may be greatly reduced.

The chloroprene rubber (CR) is a homopolymer of chloroprene and has a glass transition temperature (Tg) of about -50°C. In particular, since most of the main chains of the chloroprene rubber (CR) have a complete trans-1,4 structure, crystallization by elongation is possible due to high structural regularity, and thus unreinforced vulcanizates exhibit high tensile strength like natural rubber.

In addition, chlorine (Cl) atoms included in the chain of the chloroprene rubber (CR) reduce the reactivity of the double bond to oxidation initiators such as oxygen or ozone, thereby imparting polarity to the rubber, thereby increasing swelling resistance to hydrocarbons and at the same time providing oil resistance , also imparts flame retardancy.

In addition, the chloroprene rubber (CR) has excellent weather resistance, heat resistance, and combustion resistance compared to general-purpose rubber, excellent adhesion to polar materials such as metal, and very low gas permeability such as water vapor or air.

The chlorinated polyethylene (CPE) and the chloroprene rubber (CR) serve to improve flexibility, cold resistance, and spreading properties without deteriorating the mechanical properties of the resin composition. In addition, the base resin may further include polyolefin elastomer (POE).

The polyolefin elastomer (POE) serves to further improve the cold resistance and spreadability of the resin composition and at the same time improve the compatibility of additives with respect to the base resin.

For example, based on 100 parts by weight of the base resin, the content of the chlorinated polyethylene (CPE), the chloroprene rubber (CR), or a blending resin thereof is 50 to 100 parts by weight, and the content of the polyolefin elastomer (POE) may be 0 to 50 parts by weight.

The synthetic fibers function to improve mechanical properties, particularly tear strength, while maintaining cold resistance and laying properties of the resin composition without deterioration. The synthetic fibers may include, for example, synthetic polymer fibers, preferably polyamide fibers, such as aramid fibers.

Here, the aramid fibers may have a length of 3 mm or less, for example, 1 to 2 mm, and a diameter of 10 to 100 μm. When the length of the aramid fibers exceeds 3 mm, the dispersibility of the aramid fibers in the base resin is lowered and cohesive with each other in the base resin, so that the mechanical properties of the resin composition cannot be improved and the surface of a molded article formed from the resin composition is not improved. properties and other physical properties.

The amount of the synthetic fiber may be 1 to 20 parts by weight based on 100 parts by weight of the base resin. When the content of the synthetic fibers is less than 1 part by weight, mechanical properties, particularly tear strength, of the resin composition may be deteriorated, whereas when the content is greater than 20 parts by weight, cold resistance and laying properties of the resin composition may be deteriorated.

The other additives may include a stabilizer, a filler, a plasticizer, a crosslinking agent, a flame retardant, an antioxidant, a processing aid, and the like, depending on the use of the resin composition. The stabilizer is an additive that acts to stabilize the chlorinated polyethylene (CPE), which is relatively unstable to light and heat, and may be, for example, magnesium oxide (MgO). The content of the stabilizer may be 5 to 10 parts by weight based on 100 parts by weight of the base resin.

The filler is an additive that serves to improve mechanical properties of the resin composition, and may include, for example, carbon black, silica, and the like. In particular, the silica may have a large surface area, and the surface area of the silica may be, for example, 140 qm/g or more, preferably 160 qm/g or more.

The content of the filler may be 0 to 50 parts by weight based on 100 parts by weight of the base resin. When the content of the filler is greater than 50 parts by weight, cold resistance and spreadability of the resin composition may be greatly reduced. In particular, the content of the silica as the filler may be 20 to 35 parts by weight based on 100 parts by weight of the base resin.

The plasticizer is an additive that acts to improve the flexibility, cold resistance, spreadability, etc. of the resin composition, for example, dioctyl sebacate (DOS), dioctyl adipate (DOA), diisodecyl phthalate (DIDP) , trioctyl trimellitate (TOTM), a flame retardant plasticizer, and the like, and may be included in 15 to 30 parts by weight based on 100 parts by weight of the base resin.

When the content of the plasticizer is less than 15 parts by weight, cold resistance and laying properties of the resin composition may be deteriorated, whereas when it is greater than 30 parts by weight, mechanical properties of the resin composition may be deteriorated.

The crosslinking agent is an additive for crosslinking the base resin, and may include, for example, an organic peroxide such as dicumyl peroxide. The content of the crosslinking agent may be 5 to 15 parts by weight based on 100 parts by weight of the base resin. If the content of the crosslinking agent is less than 5 parts by weight, the degree of crosslinking of the base resin is insufficient, and mechanical properties of the resin composition may be deteriorated, whereas if it is greater than 15 parts by weight, scorch due to premature crosslinking during extrusion molding of the resin composition ( scorch) may occur.

The flame retardant is an additive that additionally imparts flame retardancy to the resin composition, and may include, for example, an antimony-based flame retardant or a bromine-based flame retardant. The amount of the flame retardant may be 1 to 10 parts by weight based on 100 parts by weight of the base resin. When the content of the flame retardant exceeds 10 parts by weight, extrudability and other physical properties of the resin composition may be deteriorated.

The antioxidant is an additive that acts to suppress deterioration of the resin composition due to oxidation, and may include, for example, an amine-based antioxidant, a phenol-based antioxidant, or a quinoline-based antioxidant. The amount of the antioxidant may be 1 to 5 parts by weight based on 100 parts by weight of the base resin.

The processing aid is an additive that serves to improve moldability of the resin composition and compatibility between the base resin and the additive, and may include, for example, a zinc-based lubricant or wax. The amount of the processing aid may be 0.5 to 3 parts by weight based on 100 parts by weight of the base resin.

The fiber-reinforced resin composition according to the present invention has improved mechanical properties such as tensile strength, tear strength, modulus, etc. while maintaining the cold resistance and laying properties without deterioration by the specific combination of the base resin, synthetic fibers and other additives. It can be.

The present invention also relates to a cable comprising a bedding and/or sheath layer formed from the fiber-reinforced resin composition. Specifically, the cable according to the present invention includes one or more cores including a conductor made of a conductive material such as metal such as copper or aluminum and an insulator surrounding the conductor providing a current flow path, a bedding surrounding the core, and the bedding. A covering sheath layer may be included, and the bedding and/or the sheath layer may be formed from the fiber-reinforced resin composition described above.

[Example]

1. Manufacturing example

After preparing the resin composition according to each of the examples and comparative examples with the components and contents shown in Table 1 below, specimens such as dog-bone type and trouzer type were prepared. Specifically, the resin composition according to each of the Examples and Comparative Examples was kneaded until the temperature of the composition reached 100 ° C. after kneading the components except for the crosslinking agent in a kneader mixer at 30 rpm until the temperature of the composition reached 100 ° C. After cooling at 3 to 5 rpm to 85 to 90 ° C., a crosslinking agent was introduced, kneaded at 10 rpm, and kneaded at 60 to 80 ° C. for about 20 minutes using a Two roll mill (roll spacing 1 to 2 mm). The units of the content shown in Table 1 below are parts by weight.

Example comparative example One 2 3 4 5 6 One 2 CPE1 75 75 75 100 100 100 75 100 CPE2 25 25 25 25 stabilizer 10 10 10 10 10 10 10 10 antioxidant 1 One One One One One One One One antioxidant 2 One One One One One One One One antioxidant 3 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 flame retardant 5 5 5 5 5 5 5 5 filler 1 10 10 10 10 10 10 10 10 filler 2 25 25 25 30 30 30 25 25 processing aid 1 0.5 0.5 0.5 0.5 0.5 processing aid 2 2 2 2 plasticizer 19 19 19 25 25 25 19 19 cross-linking agent 13 13 13 12 12 12 13 13 synthetic fiber One 2 5 One 2 5

- CPE1: chlorinated polyethylene (Cl: 35%, viscosity: 70±5 MU)

- CPE2: chlorinated polyethylene (Cl: 35%, viscosity: 95-110 MU)

- Stabilizer : Magnesium Oxide

- Antioxidant 1: Amine-based antioxidant

- Antioxidant 2: Phenol-based antioxidant

- Antioxidant 3: 2,2,4-trimethyl-1,2-dihydroquinoline

- Filler 1: Carbon Black

- Filler 2: Silica

- Processing aid 1: Zinc-based lubricant

- Processing aid 2: Wax

- Plasticizer: Dioctyl Sebacate

- Crosslinking agent: Dicumyl peroxide

- Synthetic fiber: aramid fiber

2. Property evaluation

(1) Evaluation of tensile strength, 200% modulus and elongation

Using a UTM (Universal Test Machine) device, the dog-bone specimen prepared after crosslinking each of Examples and Comparative Examples was mounted between clamps, and then the tensile strength when the specimen broke was measured, and at an elongation of 200% The load was measured to measure the 200% modulus, and the elongation was measured by measuring the ratio at break.

(2) Evaluation of tear strength

Tear strength was measured as the maximum load per unit thickness of the specimen when the Trouzer-shaped specimen prepared after crosslinking Examples and Comparative Examples was pulled and torn with one end clamped at the top of the UTM clamp and the other end clamped at the bottom of the clamp. .

(3) Evaluation of cold resistance

Five rod-shaped specimens of a certain length/thickness prepared after crosslinking Examples and Comparative Examples were left at -40 ° C, -45 ° C, or -50 ° C for 10 minutes, and then subjected to blow to crack, break, or cut specimens. Cold resistance was evaluated by measuring the number.

The evaluation results of the physical properties are shown in Table 2 below.

unit Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 The tensile strength kgf/mm2 1.60 1.75 1.52 1.93 1.95 1.84 1.73 2.10 200% modulus 0.33 0.40 0.46 0.33 0.41 0.46 - - elongation rate % 646.2 624.1 622.6 646.1 590.3 591.4 611.3 593.0 tear strength N/mm 10.9 10.9 12.8 10.8 12.8 14.3 8.5 10.5
cold resistance -40℃
Count
0/0/5 0/0/5 0/0/5 1/0/0 5/0/0 5/0/0 0/0/5 1/0/0 -45℃ - - - 4/0/0 5/0/0 4/1/0 - 3/0/0 -50℃ - - - 0/0/5 0/0/5 0/0/5 - 0/1/4

- Cold resistance: number of cracks/number of breaks/number of cuts in the specimen

As shown in Table 2, it was confirmed that the fiber-reinforced resin composition according to the present invention has excellent mechanical properties and, in particular, excellent tear strength while maintaining cold resistance without deterioration.

On the other hand, since Comparative Examples 1 and 2 did not contain synthetic fibers, it was confirmed that mechanical properties, particularly tear strength, were greatly reduced.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims described below. You will be able to. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, all of them should be considered to be included in the technical scope of the present invention.

10: core 20: bedding
30: metal braid layer 40: sheath layer

Claims (9)

A fiber-reinforced resin composition comprising a base resin and synthetic fibers dispersed in the base resin,
The base resin includes chlorinated polyethylene (CPE),
The synthetic fibers include aramid fibers having a length of 3 mm or less,
The chlorinated polyethylene (CPE) has a Mooney viscosity of 60 to 120 MU at 121 ° C,
The content of the aramid fiber is characterized in that 1 to 20 parts by weight based on 100 parts by weight of the base resin, fiber-reinforced resin composition. delete According to claim 1,
The fiber-reinforced resin composition, characterized in that the diameter of the aramid fibers is 10 to 100 ㎛. According to claim 1,
A fiber-reinforced resin composition, characterized in that the chlorine (Cl) content of the chlorinated polyethylene (CPE) is 30 to 40% by weight. delete According to claim 1,
The base resin further comprises a polyolefin elastomer (POE),
Based on 100 parts by weight of the base resin, the content of the polyolefin elastomer (POE) is characterized in that 0 to 50 parts by weight, the fiber-reinforced resin composition. According to claim 1,
A fiber-reinforced resin composition comprising at least one additive selected from the group consisting of stabilizers, fillers, plasticizers, crosslinkers, flame retardants, antioxidants and processing aids. According to claim 7,
The filler is a fiber-reinforced resin composition, characterized in that it comprises 0 to 50 parts by weight of silica based on 100 parts by weight of the base resin. At least one core comprising a conductor and an insulator surrounding the conductor;
Bedding that entirely surrounds the core, and
Including a sheath layer surrounding the bedding,
A cable wherein the bedding, the sheath layer, or both are formed from the fiber-reinforced resin composition of claim 1.

Images