KR20040053683A - Innoxious Fire Retardant Resin Composition of Indoor Optical Fiber and Optical Fiber thereof - Google Patents

Abstract

PURPOSE: A nontoxic fire retardant nonhalogen-based resin composition for the coating material of indoor optical cables and its optical cable are provided, to improve flame retardancy and to reduce remarkably the amount of smoke when burned. CONSTITUTION: The composition comprises 100 parts by weight of a base resin which is a mixture of an ethylene copolymer and a polyethylene resin; 50-200 parts by weight of an inorganic flame retardant; 0.5-20 parts by weight of a flame retardancy auxiliary; and 0.1-5 parts by weight of an antioxidizing agent. Preferably the ethylene copolymer is at least one selected from the group consisting of ethylene-vinyl acetate, ethylene-acrylic acid, ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-butyl acrylate and ethylene-α -olefin copolymers; the polyethylene resin is at least one selected from the group consisting of linear low density polyethylene, low density polyethylene, middle density polyethylene and high density polyethylene; and the inorganic flame retardant is at least one selected from the group consisting of aluminium hydroxide, magnesium hydroxide, calcium hydroxide, calcium carbonate and magnesium carbonate.

Description

Non-toxic flame retardant resin composition of indoor optical cable and its optical cable {Innoxious Fire Retardant Resin Composition of Indoor Optical Fiber and Optical Fiber}

The present invention relates to a non-toxic flame retardant resin composition for use in indoor optical cables, and more particularly to a non-halogen-based resin composition having a very low amount of non-toxic smoke generation that can be used as a coating material and coating material for indoor optical cables.

Optical cables can be broadly classified into indoor optical cables and outdoor optical cables. Among these, indoor optical cable has been increasing in demand along with the construction of subscriber networks according to the development of information and communication technology and the construction of business districts and business buildings in large cities.

Since indoor optical cables are used inside buildings, efforts have been made to change the materials and design of optical cables to reduce the incombustibility and smoke generation in order to minimize the loss of lives and property caused by combustion gases in the event of fire. .

In general, indoor optical cables have a structure in which a tight buffer coated optical fiber is coated like a tension member.

Conventionally, PVC resin composition was used as a base resin as a coating material and coating material (hereinafter, "coating coating material") of this indoor optical cable.

As the plasticizer, phthalate plasticizers such as di-2-ethylhexyl phthalate (DOP), dizononyl phthalate (DINP), dizodecyl phthalate (DIDP) and ditridecyl phthalate (DTDP), and di-2-ethylhexyl Fatty acid plasticizers, such as adipate (DOA) and di-2-ethylhexyl azelate, trimerate plasticizers, such as tri-2-ethylhexyl trimellitate (TOTM) and trisoxyl trimellitate, and tetrabromine Bromine plasticizers, such as phthalate ester, and phosphate plasticizers, such as tri-2-ethylhexyl phosphate (TOP) and tricresyl phosphate (TCP), were used alone or in a mixture thereof.

As the stabilizer, tribasic reed sulfate (TLS), dibasic reed phosphite (DLP), or the like alone or a mixture thereof was used.

As the filler, natural calcium carbonate, synthetic calcium carbonate, kaolin, feldspar, and the like alone or in a mixture thereof were used.

As the flame retardant, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium calcium carbonate, magnesium calcium carbonate, magnesium hydroxide and the like were used alone or in a mixture thereof to improve flame retardancy.

As the flame retardant aid, antimony oxide, zinc borate, zinc stannate, or an ammonium flame retardant alone or a compound thereof was used.

When the conventional PVC resin composition is used as a coating coating material, a large amount of dioxins and hydrogen chlorides are generated during combustion, and this gas is known to be highly corrosive and toxic. In addition, the conventional PVC composition generates a large amount of smoke during combustion, which makes it difficult to extinguish the fire.

It was developed to improve the above problems and to use environmentally friendly non-toxic non-halogen polymer composition as optical cable material. As the base resin of the polymer composition, nylon resin or thermoplastic polyester may be used alone, and an ethylen copolymer and polyethylene may be used alone or in a mixture thereof.

The ethylene copolymers include ethylene vinyl acetate (EVA), ethylene acrylic acid (EAA), ethylene methacrylic acid (EMA), ethylene ethyl acrylate (EEA), or ethylene butyrate acrylate copolymer and ethylene alpha olefin copolymer. Either alone or mixtures thereof may be used.

In addition, as the polyethylene, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE) may be used alone or a mixture thereof.

However, the improved composition, that is, the environmentally friendly non-toxic non-halogen polymer composition, is not without problems. That is, when the polymer used as the coating coating material has a property of resisting flow, a coiling effect is generated in which the optical cable does not recover to an unfolded state before being wound after being wound by the bobbin and bent.

In addition, in the case of using thermoplastic polyester or nylon as the coating coating material, the manufacturing cost of the optical cable is increased, and in particular, when nylon is used as the coating material, adhesiveness with the optical fiber core layer becomes strong, thereby causing a problem in escaping it.

In addition, when the coating coating material has high crystallinity because the crystalline polymer such as ethylene copolymer and polyethylene is not properly selected, the mechanical properties such as strength, elasticity, abrasion resistance, and impact resistance may be good. The optical cable reacts sensitively, resulting in a large amount of optical loss variation. In the end, this is a major cause of impairment of the optical fiber transmission capacity.

In addition, mechanical and environmental properties testing of optical cables should meet Bellcore GR 409 specification. One of the mechanical and environmental property tests, the Temperature Cycling Test, involves winding a 1-km-long optical cable into the bobbin and applying a temperature change from 0 ° C to 50 ° C to the optical cable in two or more cycles for a certain period of time. This test measures the amount of change in light loss, which is a measure of the transmission capacity.

However, when the optical cable is manufactured using a conventional non-halogen polymer composition, the compression test, tensile test, torsion test and continuous impact test related to the mechanical properties of the material among the mechanical and environmental property tests according to Bellcore GR 409 standard The problem arises that it is excellent but cannot meet the requirements of the temperature cycling test, which relates to the environmental properties of the material.

The present invention was devised to solve the above problems, and provides a non-toxic flame retardant resin composition that significantly reduces the amount of smoke generated during combustion, and does not emit toxic gases compared to conventional flame retardant resin compositions. have.

In addition, another object of the present invention is to provide a composition which can prevent a change in the optical loss of an optical cable by developing a composition having a small deformation with respect to a temperature change.

In order to achieve the above object, the present invention relates to a non-halogen-based resin composition having a very low amount of non-toxic smoke generation that can be used as a coating coating material for indoor optical cables, and the composition is mixed with an ethylene copolymer and a polyethylene resin. 100 parts by weight of one base resin; 50 to 200 parts by weight of inorganic flame retardant; 0.5 to 20 parts by weight of flame retardant aids; And 0.1 to 5 parts by weight of antioxidant.

The present invention also discloses an indoor optical cable using the above composition as a coating coating material in an indoor optical cable having a structure in which an optical fiber coated with a tight buffer is coated with a tensile material.

Hereinafter, preferred embodiments of the present invention will be described in detail. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the exemplary embodiments described herein are only exemplary embodiments of the present invention and do not represent all of the technical ideas of the present invention, and various equivalents and modifications that may substitute them at the time of the present application may be used. Understand that there may be

In the present invention, a low crystalline non-toxic non-halogen-based polymer composition containing an inorganic flame retardant, a flame retardant aid, an antioxidant, and a processing aid is added to 100 parts by weight of a resin used by mixing an ethylene copolymer and a polyethylene resin as a coating coating material for an indoor optical cable. It starts.

The ethylene copolymers used in the present invention are ethylene vinyl acetate (EVA), ethylene acrylic acid (EAA), ethylene methyl acrylate (EMA), ethylene ethyl acrylate (EEA), ethylene butylacrylate copolymer or ethylene alpha olefin air The coalescing is used alone or mixtures thereof.

The polyethylene resin used in the present invention uses linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE) alone or in a mixture thereof.

In the case of mixing the ethylene copolymer and the polyethylene resin, the ratio of polyethylene should not exceed 20 parts by weight based on 100 parts by weight of the base resin. It is because when 20 weight part or more of polyethylene is used, crystallinity becomes high and the shrinkage rate of a composition increases.

Therefore, it is preferable that the composition of this invention uses 80-95 weight part of ethylene copolymers and 5-20 weight part of polyethylene resins as a base resin.

If the polyethylene resin content is 5 parts by weight or less, the mechanical properties and heat resistance are lowered, which is not preferable. On the other hand, when the polyethylene resin content is 20 parts by weight or more, the crystallinity is too high, leading to an increase in the shrinkage rate, which is also undesirable.

In addition, the ethylene copolymer is preferably used in the range of 30% to 70% of the content of the vinyl material. For example, when ethylene vinyl acetate is used as the ethylene copolymer, when the content of vinyl acetate is 30% or less, the crystallinity is increased, leading to an increase in shrinkage. On the other hand, when the content of the vinyl acetate is 70% or more, the adhesion becomes strong, which causes problems in peeling the coating material from the optical fiber core layer.

Therefore, the ethylene copolymer has low crystallinity only when the content of the vinyl material is in the range of 30% to 70%. Low-density polymers have a structure in which molecules cannot be piled up because of their large molecular chains, branches, and functional groups, and thus have a smaller shrinkage rate than polymers having relatively high crystallinity.

In addition, the inorganic flame retardant used in the present invention alone or these inorganic flame retardants and non-surface treated inorganic flame retardant surface treated with a material such as silicon or stearic acid or patty having a specific surface area (BET) of 5 to 15mm ² / g. It mixes and uses it with 50-200 weight part with respect to 100 weight part of base resin. If it is less than 50 parts by weight may not exhibit a flame retardancy and low smoke effect, and more than 200 parts by weight may cause a problem that the mechanical properties and workability is reduced.

In the present invention, the inorganic flame retardant in the case of metal hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium calcium carbonate, magnesium hydroxide as a basic flame retardant to release the crystallized water during oxidation of the composition to absorb the heat of combustion Because of this self extinguishing.

In addition, in the present invention, as the flame retardant adjuvant, the zinc borate, the zinc sterate, and the silicone rubber alone or a mixture thereof are used in an amount of 0.5 to 20 parts by weight based on 100 parts by weight of the base resin. When the content of the flame retardant aid is 0.5 parts by weight or less, a flame retardant effect cannot be expected, and when it is 20 parts by weight or more, mechanical properties and heat resistance can be reduced.

Optionally, 0.1 to 5 parts by weight of phenolic, amine or thioester alone or a mixture thereof is used as antioxidant in the present invention. When the content of the antioxidant was 0.1 parts by weight or less, the improvement of the heat resistance could not be expected. On the other hand, when the content of the antioxidant was 5 parts by weight or more, the mechanical properties decreased.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example 1

Example 1 10 parts by weight of high-density polyethylene, 90 parts by weight of ethylene vinyl acetate (VA content 43%) base resin, 100 parts by weight of aluminum hydroxide inorganic flame retardant, 1 part by weight of phenolic resin antioxidant, 3 parts by weight of ginko borate as flame retardant aid To prepare a specimen.

The prepared specimens were evaluated for flame retardancy according to the IEC 332-3C flame retardant test (combustion length of 240 cm or less). In addition, tensile strength (0.90 Kg / mm ² or more) and elongation (more than 120%) were evaluated according to ASTM D638.

Temperature Cycling test measured loss change (less than 0.60 dB / Km) after 1st and 2nd cycle in the temperature range according to Bellcore GR 409.

In this test, the loss change was measured while changing the temperature from 0 ° C. to 50 ° C. (1Cycle) at an initial temperature of 20 ° C., and then to 0 ° C. and 50 ° C. (2Cycle).

Test results of the optical cable according to Example 1 are shown in Table 1 below.

Example 2

Instead of 90 parts by weight of ethylene vinyl acetate (VA content 43%), 90 parts by weight of ethylene vinyl acetate (VA content 60%) was carried out in the same manner as in Example 1, the results are shown in Table 1 below.

Example 3

Instead of 100 parts by weight of aluminum hydroxide, it was carried out in the same manner as in Example 2, except that 150 parts by weight of aluminum hydroxide was used, the results are shown in Table 1 below.

Comparative Example 1

In Comparative Example 1, 70 parts by weight of high-density polyethylene, 30 parts by weight of ethylene vinyl acetate (VA content 43%), base resin, 40 parts by weight of aluminum hydroxide, inorganic flame retardant, 1 part by weight of phenolic resin, and 3 parts by weight of flame retardant as a flame retardant It carried out similarly to Example 1 except having produced the test piece. The test results are shown in Table 2 below.

Comparative Example 2

Except for using 100 parts by weight of aluminum hydroxide instead of 40 parts by weight of aluminum hydroxide, it was carried out in the same manner as in Comparative Example 1, the results are shown in Table 2 below.

Comparative Example 3

Comparative Example 3 was carried out in the same manner as in Comparative Example 2, except that 100 parts by weight of ethylene vinyl acetate was used as the base resin, and the results are shown in Table 2 below.

Comparative Example 4

Comparative Example 4 was performed in the same manner as in Comparative Example 2, except that 100 parts by weight of high density polyethylene was used as the base resin, and the results are shown in Table 2 below.

Example 1 Example 2 Example 3 HDPE 10 10 10 EVA (VA 43%) 90 EVA (VA 60%) 90 90 Aluminum hydroxide 100 100 150 Phenolic Resin One One One Jin borate 3 3 3 Test result Light loss change after 1 cycle 0.20 0.15 0.10 Light loss change after 2 cycles 0.40 0.25 0.20 Flame retardant 95 80 65 The tensile strength 1.10 1.02 1.05 Elongation 205 220 200

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 HDPE 70 70 100 EVA (VA 43%) 30 30 EVA (VA 60%) 100 Aluminum hydroxide 40 100 100 100 Phenolic Resin One One One One Jin borate 3 3 3 3 Test result Light loss change after 1 cycle 0.63 0.60 0.25 0.90 Light loss change after 2 cycles 1.25 1.20 0.31 2.45 Flame retardant 270 90 85 80 The tensile strength 2.80 2.10 0.56 0.45 Elongation 127 95 103 54

As can be seen from the comparative examples and examples described above, when the low-integrity non-toxic non-halogen polymer composition was used as the coating coating material, the toxic gas was not discharged for the comparative example, and the change in light loss due to shrinkage was small. have.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

According to this invention, compared with the conventional flame-retardant resin composition, the quantity of the smoke produced at the time of combustion can be reduced significantly. In addition, the composition of the present invention can reduce the human damage generated in the fire does not emit toxic gas.

Claims (10)

100 parts by weight of a base resin in which an ethylene copolymer and a polyethylene resin are mixed; 50 to 200 parts by weight of inorganic flame retardant; 0.5 to 20 parts by weight of flame retardant aids; And 0.1 to 5 parts by weight of antioxidant; Non-toxic flame retardant resin composition containing. The method of claim 1 Non-toxic flame retardant resin composition, characterized in that the polyethylene resin content is 5 to 20 parts by weight based on 100 parts by weight of the base resin. The method of claim 1, The ethylene copolymer is a group consisting of ethylene vinyl acetate (EVA), ethylene acyl acid (EAA), ethylene methyl acrylate (EMA), ethylene ethyl acrylate (EEA), ethylene butyl acrylate copolymer or ethylene alpha olefin copolymer Non-toxic flame retardant resin composition, characterized in that at least one resin selected from. The method of claim 1, The polyethylene resin is a non-toxic flame retardant resin composition, characterized in that at least one resin selected from the group consisting of linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE) or high density polyethylene (HDPE). The method of claim 1, The ethylene copolymer is a non-toxic flame retardant resin composition, characterized in that the content of the vinyl material 30% to 70%. The method of claim 1, The inorganic flame retardant may be an inorganic flame retardant surface-treated with a material such as silicon or stearic acid or a patty having a specific surface area (BET) of 5 to 15 mm ² / g, an inorganic non-surface flame retardant, or a mixture thereof. Non-toxic flame retardant resin composition. The method of claim 1, The inorganic flame retardant is a non-toxic flame retardant resin composition, characterized in that at least one resin selected from the group consisting of aluminum hydroxide, magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium calcium carbonate or magnesium hydroxide. The method of claim 1 The flame retardant adjuvant is non-toxic flame retardant resin composition, characterized in that at least one resin selected from the group consisting of zinc borate, zinc stenate or silicone rubber. The method of claim 1, The antioxidant is a non-toxic flame retardant resin composition, characterized in that at least one resin selected from the group consisting of phenolic, thioester-based, or amine-based. In an indoor optical cable in which an optical fiber coated with a tight buffer is coated with a coating material together with a tensile material, The buffer and the covering material, An optical cable comprising the composition of claim 1.