KR100876124B1 - Highly extrudable and thermally stable environmently friendly flame retardant resin composition and related electric wires - Google Patents

Abstract

An environmentally friendly flame retardant resin composition, and an electric wire coated with the composition are provided to improve the extrusion processability and heat resistance of an electric wire. A resin composition comprises 100 parts by weight of a resin mixture which comprises 50 ~ 80 wt% of a polypropylene-based resin, 5 ~ 20 wt% of a high molecular weight styrene-based block copolymer resin containing 30 wt% or less of styrene and having a 5% solution viscosity of toluene solvent of 300 mPas or more at 30 deg.C, and 10-30 wt% of a polyolefin-based copolymer resin; and 50-200 parts by weight of a metal hydrate. The resin mixture contains 10-40 wt% of a grafted modified resin of an acid anhydride.

Description

Highly extrudable and thermally stable environmently friendly flame retardant resin composition and related electric wires}

The present invention improves the balance of melt flow and heat resistance with polypropylene resin as the main raw material, so that the appearance of the extrudate is not only smoothly maintained even when extruded at a very high speed in the wire extruder, but also exhibits heat resistance that can withstand high temperatures without crosslinking. At the same time, the present invention relates to an environmentally friendly flame retardant resin composition and an electric wire coated therewith that are excellent in extrusion processability and heat resistance, which generate little smoke during combustion and do not generate harmful halogen gas and environmental hormone substances.

Representative coating materials of conventional automotive wires have been used by cross-linking or non-crosslinking polyvinyl chloride (PVC) resins and polyolefin (PO) resins flame-retardant with halogen-based flame retardants. The problem of environmental pollution and harmfulness of resins and halogen flame retardants has emerged, and the replacement of environmentally friendly non halogen (halogen free or halogen free flame retardant resins) is actively progressing. In addition, much research has been conducted on the development of materials that can be reused by not crosslinking resins as much as possible in terms of recycling resources. Polymer materials most commonly used as coating materials for automobile wires include PVC resins and polyolefin (PO) resins. PVC wires using plasticizers such as diisononyl phthalate (DINP) or diisodecyl phthalate (DIDP) are mainly used in the interior, exterior and rear trunk areas of automobiles where the required heat resistance is not high. Cross-linked PVC (trioctyl trimellitate (TOTM), such as a cross-linked PVC (trimellitate-based plasticizer) having excellent heat resistance characteristics or by irradiating electron beam to the PVC resin Crosslinked PVC (XL-PVC) can be used for higher grades of heat resistance. The former is classified into ISO 6722, the international standard for automobiles, and the former is class 1, with continuous use temperature of 80 ℃, and the latter is class 2, with continuous use temperature of 100 ℃. PVC resin can be used normally up to Class 2 grade. Since engine parts always generate high heat, wires of Class 3 grade (continuous use temperature 120 ℃) or Class 4 grade (continuous use temperature 150 ℃) with more severe heat resistance conditions should be used. Class 3 grades are usually crosslinked PO (XL-PO) resins which are crosslinked by irradiation with electron beams to polyolefin copolymer resins such as polyethylene (PE) resin or ethylene vinylacetate copolymer (EVA) resin. In class 4 and above, fluorine resin and silicon resin with excellent heat resistance are used.

Since these automotive wires require a relatively high degree of flame retardancy, the use of flame retardants is inevitable. PVC resins, fluorine resins and silicone resins are easily flame retardant because the resin itself has a certain degree of flame retardancy, but polyolefin resins have a large amount of flame retardant to increase flame retardancy due to their high combustibility, which causes a lot of deterioration in other properties. To bear the Therefore, the conventional polyolefin-based flame retardant resins for automobile wires have to reinforce physical properties by electron beam crosslinking or the like.

In general, the most effective method for the flame retardant of flammable polymer resin is the addition of halogen flame retardant. Halogen flame retardant has excellent flame retardant efficiency, but recently, it has the disadvantage of generating toxic halogen gas during combustion. Even if the efficiency is low, the method of flame retarding with environmentally friendly non-halogen flame retardant which is relatively less dangerous to the human body is being advanced.

Since the car wire is mounted on the driving car, it receives kinetic energy such as vibration at all times, and sometimes partial friction may occur due to the vibration.When it is mounted on the engine part, it is not only vibrated or friction, but also by the heat energy generated by the engine. It is deteriorated and is exposed to the risk of fire by electric shock. Therefore, automotive wires basically require high mechanical properties, heat resistance, flame retardancy, and abrasion resistance. In addition, wire cable manufacturers have been increasing productivity by making wire extrusion speed as high as possible. Therefore, automotive wire coating materials must satisfy both extrusion properties as well as requirements.

In general, PVC resin for automotive wire is a material having excellent physical properties and wire extrudability except for environmental problems. In particular, automotive wire manufacturers who are familiar with the excellent extrusion processability of PVC resins whose extrusion appearance is maintained even at high wire extrusion speeds are dissatisfied with the low productivity due to the low extrusion speed of materials developed as eco-friendly materials.

Conventional eco-friendly resins are the most common polyolefin resins, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene ( PE resin such as linear low density polyethylene (LLDPE) and very low density polyethylene (VLDPE), homo polypropylene, block copolypropylene, random polypropylene copolymer ( polypropylene (PP) resins such as random copolypropylene, random terpolypropylene, ethylene propylene rubber (EPR), ethylene propylene diene monomer (EPDM), etc. EP rubbers, ethylene vinylacetate (EVA), methyl acrylate copolymer (ethylene m) ethylacrylate (EMA), ethylene ethylacrylate (EEA), ethylene butylacrylate (EBA), ethylene acrylic acid (EAA), and ethylene methyl methacrylate copolymer (ethylene methyl polyolefin copolymer resins such as methacrylic acid (EMMA), and modified polyolefin resins in which the above polyolefin resin is modified with an acid anhydride, and styrene butadiene random copolymer (SBR) and styrene butadiene styrene block Copolymer (styrene butadiene styrene block copolymer; SBS), styrene isoprene styrene block copolymer (SIS), styrene butadiene butylene styrene block copolymer (SBBS), styrene ethylene butylene styrene block copolymer styrenic block copolymers such as styrene block copolymers, SEBS, styrene ethylene propylene block copolymers (SEP) and styrene ethylene propylene styrene block copolymers (SEPS) SBC) resins, and modified styrene block copolymer resins modified with an acid anhydride and the like.

Conventional flame-retardant resin compositions, for example, as described in Japanese Patent Application Laid-Open Nos. 2002-212354, 2002-212378, Korean Patent No. 0589510, 0612405, 0633546, 0830419, etc. Magnesium dihydroxide (MDH) surface-treated or untreated with a surface treatment agent such as fatty acids, metal fatty acids, fatty alcohols, silanes, amines, phenols, and phenols; ), Metal hydrates such as aluminum trihydroxide (ATH), calcium dihydroxide (CDH) and zinc borate (ZB), and melamine cyanate (surface treated or untreated with the above surface treatment agents) Non-halogen-based flame retardants such as phosphorus and nitrogen compounds such as melamine cyanurate (MC), ammonium polyphosphate (APP) and polyamine melamine (melamine polyphosphate (MPP)) are added alone or in combination, and silicone And calcium carbonate, clay, talc, mica, silica, wollastonite, surface-treated or untreated with a flame retardant aid such as red phosphorus and the above surface treatment agents. ), Inorganic fillers such as barium sulfate and zinc oxide, silane or titanium coupling agents (CA), phenolic, hindered phenolic, amine and Stabilizers such as antioxidants such as thio-based antioxidants (AO agents), ultraviolet stabilizers (UV stabilizers) and metal deactivators (MDAs), calcium stearate (Ca-St), Zinc stearate (Zn-St) and magnesium stearate (magnesium stearate); Metal stearic acid such as Mg-St), lubricants such as polyethylene wax (PE wax), polypropylene wax (PP wax) and amide wax, paraffinic oil, aromatic oil, Processing oils such as naphthenic oil and silicone oil, trimethylpropane trimethacrylate (TMPTMA), and triallyl isocyanurate (TAIC) Background Art A flame retardant resin composition based on incorporation of a crosslinking aid of a multifunctional monomer system alone or in combination has been developed.

Inorganic flame retardants such as metal hydrates, which are most commonly used as non-halogen flame retardants, have lower flame retardant efficiency than halogen-based flame retardants such as chlorine and bromine compounds. have. Until economical non-halogen flame retardant with high flame retardant efficiency is developed in the future, various problems such as deterioration of physical properties and wire extrudability due to the high amount of non-halogen flame retardant are present. In order to improve this, even when a large amount of flame retardants are mixed, so-called fillers having low physical properties, such as filler loading, for example, EVA resin having a high content of vinyl acetate (VA), ethyl acrylate (ethylacrylate); EA) EEA resin, VLDPE, EP rubber and styrene block copolymer resin with high content are being applied.In order to reinforce the deteriorated physical properties, various compatibilizers to improve interfacial adhesion between flame retardant and resin are introduced. A method of surface treatment with a coating material having good compatibility with resin on the surface has been applied. In addition, many improvements have been made, including the use of a synergistic effect with flame retardant aids that increase the flame retardant efficiency of flame retardants, thereby reducing the total amount of flame retardant additives.

However, the conventional crosslinked polyolefin flame retardant resin has a limitation in balancing the physical properties and the extrusion processability of the wire at the same time. Since they have been mainly developed for physical properties, they do not give the extrusion processability that satisfies the requirements of wire manufacturers. Among polyolefin resins, EVA resin with high VA content has excellent filler loading property, and it is used as a coating material for automobile wire by incorporating a large amount of flame retardant in combination with PE resin etc., but the melting point of the resin itself is low and the tensile strength is insufficient. In order to compensate for this, it is necessary to go through a crosslinking process such as electron beam irradiation, and in the case of polypropylene resin based, it has excellent heat resistance and shows excellent physical properties without crosslinking process, but PVC has insufficient filler loading property. It is limited to handle the extrusion speed as fast as the resin, and because of the rigid properties of the PP resin itself, there were many problems to be solved in terms of flexibility and wire harness.

However, as a part of the light weight reduction of automobiles to improve fuel efficiency of automobiles, research on thinning and thinning of automotive wires is being actively conducted. As the insulation thickness of the wire becomes thinner, problems such as flexibility of the coating material and wire harness properties are accompanied. Since it is naturally reduced, it is judged that it is possible to apply a rigid polypropylene resin, and there are many advantages in terms of economics if it can be overcome by technically controlling the disadvantages such as extrusion processability.

In general, the smaller the diameter of the wire, the thinner the conductor of the metal material and the thinner the coating thickness of the insulating layer, so the burden on the flexibility and harness of the coating material tends to decrease. Therefore, it is possible to develop a resin composition capable of satisfying flexibility and electric wire harness using polypropylene resin having high hardness as a main raw material, because the insulation thickness of automotive wires is getting thinner with the trend of lighter weight of automobiles.

The present invention has been made to solve the above-mentioned problems of the prior art, and in particular, in replacing conventional cross-linked polyolefin (PO) resin of the PVC for automobile wire and halogen flame retardant with an environmentally friendly resin, While using, the extrusion processability of electric wire shows the same level or higher than the PVC resin for automobile wires, and the heat resistance of the electric wire is also to provide an eco-friendly flame-retardant resin composition having the same or higher physical properties as the crosslinked polyolefin resin for automobile wires. .

In addition, the present invention is an environmentally friendly flame-retardant resin composition that generates less smoke during combustion and does not generate harmful halogen gas and environmental hormone substances, and can replace PVC resins and class 3 grade crosslinked polyolefin resins used in conventional automobile wires. In addition, to provide a variety of wires, such as electric wires for electrical equipment, as well as environmentally friendly flame-retardant resin composition with excellent extrusion properties and heat resistance that can be used alternatively in most fields where environmental destruction and hazards are emerging.

In addition, the present invention is to provide a flame-retardant resin composition that is particularly effective in the wire having an insulation thickness of 0.2 mm or less, high heat resistance at high temperature without crosslinking, as well as reuse of resources.

The present invention outperforms the extrudeability of conventional PVC resins by using a high-molecular weight styrene block copolymer resin, polyolefin copolymer resin and modified resin thereof in a balanced manner while using polypropylene resin as an environmentally friendly resin. The present invention relates to an environment-friendly flame-retardant resin composition having a balance of physical properties and processability, comparable to the excellent heat resistance of a crosslinked polyolefin resin even without crosslinking, and which does not generate toxic halogen gas upon combustion.

The inventors of the present invention attempted to impart eco-friendliness to the electric wires in order to construct a new resin composition in which the properties of the eco-friendly flame retardant resin material and the extrusion processability were not satisfied by the conventional technology, and to improve the physical properties of the electric wires. In order to improve wire extrusion processability.

In other words, in order to provide environmentally friendly wires, the application of halogen-free materials, in particular, polypropylene resin, styrene block copolymer resin and polyolefin copolymer resin, and metal hydrate inorganic flame retardant In addition, the application of additives without harmful heavy metals was considered.

In order to improve the physical properties of wires, long-term heat resistance to heat aging at 150 ° C for 240 hours and short-term high temperature heat resistance to withstand 30 minutes at 200 ° C, improvement of tensile strength and elongation, improvement of wear resistance and flame resistance Etc. Specifically, in order to improve the long-term heat resistance, the optimum stabilizer combination was examined based on polypropylene resin having a high melting temperature, and the short-term high temperature heat resistance was introduced at a high temperature by introducing a high molecular weight styrene-based block copolymer resin. Flow was controlled. In order to improve the tensile strength and abrasion resistance, the introduction of polypropylene resin and high molecular weight styrene-based block copolymer resin having excellent tensile strength and abrasion resistance basically, the optimum resin combination, optimum particle size and ratio in consideration of compatibility Application of inorganic flame retardant having surface area, minimization of inorganic flame retardant content considering tension reduction, introduction of compatibilizer to improve interfacial adhesion between resin and inorganic flame retardant, improvement of dispersibility and optimum compatibility with resin by optimum surface treatment of inorganic flame retardant, water Maximization of compatibility between inorganic flame retardants and resins by lipolysis was considered. In addition, in order to improve the elongation rate, it is optimal considering the introduction and compatibility of styrene-based block copolymer resins and polyolefin copolymer resins, which have a low free elongation rate even when a large amount of free volume is filled in the inorganic material. The combination of resins, the application of inorganic flame retardants with optimum particle size and specific surface area, the content of inorganic flame retardants in consideration of the elongation rate reduction, the dispersibility by the optimum surface treatment of inorganic flame retardants, and the compatibility with resins were examined. In order to improve the flame retardancy, the introduction of non-toxic non-halogen flame retardants, application of inorganic flame retardants having an optimum particle size and specific surface area, improvement of dispersibility by optimum surface treatment of inorganic flame retardants, introduction of flame retardant aids, combination of optimal inorganic flame retardants and flame retardant aids And the like.

In order to improve the extrusion processability of the electric wire, the flowability of the resin composition was improved and the extrusion load was reduced. Specifically, the introduction of a highly flexible polypropylene resin to compensate for the flow deterioration caused by the addition of a large amount of inorganic flame retardant, the reduction of the extrusion load by the surface treatment of the inorganic flame retardant, the minimization of the use of flame retardants, the flow of the resin by the optimal lubricant combination, etc. Properties improvement and extrusion load reduction were examined.

The present invention is a resin mixture composed of a polypropylene resin, a high molecular weight styrene block copolymer resin, a polyolefin copolymer resin,

Among the resin mixtures, a highly flexible polypropylene resin having a melt index of 10 g / 10 minutes or more at a load of 230 ° C. and 2.16 kg is necessarily included, and a modified resin having a form in which an acid anhydride is grafted is necessarily included.

With respect to 100 parts by weight of the resin mixture, it relates to an environmentally friendly flame-retardant resin composition excellent in extrusion processability and heat resistance comprising 50 to 200 parts by weight of metal hydrate.

More specifically, the present invention is 50 to 80% by weight of polypropylene resin, styrene content of 30% by weight or less, high molecular weight styrene-based block copolymer resin 5 ~ 5% solution viscosity of toluene solvent at 30 ° C 5 ~ A resin mixture consisting of 20% by weight, 10-30% by weight of polyolefin copolymer resin,

Among the resin mixtures, 10 to 40% by weight of a highly flexible polypropylene resin having a melt index of 10 g / 10 min or more at a load of 230 ° C. and 2.16 kg, and a modified resin having a form of an acid anhydride is 10 to 40 wt%. % By weight,

With respect to 100 parts by weight of the resin mixture, it relates to an environmentally friendly flame-retardant resin composition excellent in extrusion processability and heat resistance comprising 50 to 200 parts by weight of metal hydrate.

In addition, any one or two or more selected from flame retardant aids, antioxidants, lubricants, compatibilizers, processing oils, inorganic fillers, colorants, and crosslinking aids may be further added to the flame retardant resin composition as necessary.

In other words, the resin composition of the present invention is a polypropylene resin as the main raw material, while the flow rate at high temperature by controlling the flowability at high temperature by adding a high molecular weight styrene-based block copolymer having a very low melt flow property to the wire coated with the resin composition of the present invention Even without crosslinking, no melting or cracking occurs even after heating for 30 minutes at 200 ° C, which is much higher than the crystalline melting temperature of polypropylene under no load, and the polypropylene resin having a very high melt flowability is properly combined. This ensures that the appearance of the extrudate remains smooth even when extruding at a very high speed from a general-purpose wire extruder, while it produces less smoke during combustion and does not generate harmful halogen gas and environmental hormone substances. It is about a flame-retardant resin composition.

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

In the present invention, the polypropylene resin is any one or two selected from homo polypropylene resin, block polypropylene copolymer resin, random polypropylene copolymer resin, random polypropylene terpolymer resin and acid anhydride graft modified resin thereof Blends of the above can be used, the content of which is used in 50 to 80% by weight of the total resin mixture. More preferably, 10 to 40% by weight of the highly flexible polypropylene resin having a melt index of at least 10 g / 10 minutes, more preferably 10 to 120 g / 10 minutes, at a load of 230 ° C. and 2.16 kg in the resin mixture. It includes.

The high-flow polypropylene resin is used to improve the melt flowability of the resin mixture to improve the moldability, when used in less than 10% by weight to compensate for the degradation of extrusion processability due to the large amount of flame retardant fillers Insufficient, when used in excess of 40% by weight, the extrusion processability is better, but the physical properties such as short-term high temperature heat resistance and tensile strength and elongation are significantly increased.

In addition, the polypropylene resin containing the high-flow polypropylene resin is preferably used in 50 to 80% by weight of the total resin mixture, when used less than 50% by weight wear resistance is worse, 80% by weight When used in excess, the elongation rate and the extrudability tend to decrease.

The melt index of the polypropylene resin is about 0.5 to 10 g / 10 minutes for extrusion, about 5 to 40 g / 10 minutes for injection, and the melt index is very large for fiber spinning, ranging from tens to hundreds or more. In addition, the melt index of the modified polypropylene resin modified with acid anhydride or the like is diluted or modified into virgin (polypropylene) polypropylene to be produced as a variety of acid anhydride modified products, the melt index can be used from several to several hundreds .

In the present invention, the high molecular weight styrene-based block copolymer is styrene butadiene styrene resin, styrene isoprene styrene resin, styrene butadiene butylene styrene resin, styrene ethylene butylene styrene resin, styrene ethylene propylene styrene resin and acid anhydride graft modification thereof Any one or two or more blends selected from resins can be used, the content of which is 5 to 20% by weight of the total resin mixture. If less than 5% by weight, the effect of improving short-term high temperature heat resistance is small, and if it exceeds 20% by weight, extrusion processability is drastically reduced.

More preferably, the styrenic block copolymer resin has a styrene content of 30% by weight or less, and at 30 ° C., a 5% solution viscosity of the toluene solvent is preferably 300 mPas or more, more preferably 300 to 1000 mPas.

The molecular structure of the styrenic block copolymer resin is a soft block (or a rubber block such as hard block of styrene, butadiene, ethylene buthylene, and ethylene propylene). (rubber block)], which shows various physical properties depending on the content and type of hard block and soft block. In terms of physical properties, hard blocks contribute to tensile strength and soft blocks contribute to filler loading and elongation. Therefore, the styrene-based block copolymer resin may be classified as a thermoplastic elastomer having a physical property such as a crosslinked rubber at room temperature, but when the heat is applied, the hard block melts and an external force is applied.

As the content of styrene, which is a hard block, increases in tensile strength but decreases in elongation rate due to a decrease in filler loading, it was determined that the styrene content does not exceed 30 wt% in terms of physical properties. .

The melt index of the styrenic block copolymer resin depends on the type of hard block and soft block and the degree of polymerization thereof. The higher the molecular weight, the lower the melt index. In addition, styrene-based block copolymer resins have a small decrease in tensile strength and elongation even at high temperatures, such as crosslinked rubber, and are excellent in wear resistance. High molecular weight styrene-based block copolymer resins exhibit high molecular weight and are unlikely to deform at high temperatures without external force. In other words, by using a high molecular weight styrene-based block copolymer resin in accordance with the above properties by mixing in the above content, it is possible to solve the problem of short-term high temperature heat resistance by not flowing well at high temperature even without crosslinking. If the content of the high molecular weight styrenic block copolymer resin is too high, the melt flowability is too low, making it difficult to process in a general-purpose extruder. In terms of long-term heat resistance, it is more preferable to use SEBS resins and SEPS systems having no double bonds in the molecule.

The high molecular weight styrenic block copolymer resin used in the present invention melts in a polar solvent because its molecular weight is so high that the melt index cannot be measured because no melt flow occurs at 230 ° C. and a load of 2.16 kg. To indicate flowability. It is a high molecular weight of approximately 250,000 to 300,000 by weight average molecular weight, it does not deform well even at high temperatures without applying external force after molding. Such characteristics are very effective in satisfying the short-term high temperature heat resistance of 120 ℃ grade automotive wires, which are class 3 grades, showing the same performance as crosslinked rubber. However, as the molecular weight is high, the extrusion load is so large that it is important to limit the amount of addition.

In the present invention, the polyolefin copolymer resin is ultra low density polyethylene resin (VLDPE), vinyl acetate ethylene copolymer resin (EVA), methyl acrylate copolymer resin (EMA), ethyl acrylate copolymer resin (EEA), butyl acrylic acid Any one or two or more blends selected from ethylene copolymer resins (EBA) and their acid anhydride graft modified resins may be used, the content of which is 10 to 30% by weight of the total resin mixture. If it is less than 10% by weight, the improvement in elongation is limited. If it exceeds 30% by weight, the wear resistance and the decrease in tensile strength are remarkable.

The polyolefin copolymer resin is less abrasion resistance than the styrene block copolymer resin, but is excellent in filler loading property, and is useful when filling a large amount of flame retardant, in particular EVA resin, EMA resin, EEA resin and EBA resin combustion It is known to increase the flame retardancy by contributing to the formation of the char (char), which gives a time barrier effect. In the case of VLDPE resin, there are products using butene, hexene and octene as copolymers. The octene copolymer is excellent in terms of physical properties and butene copolymer in terms of extrusion processability, but the molecular weight and air content are excellent. It is good to select in consideration of the type and content of coalescence. In general, the higher the molecular weight and the higher the content of the copolymer, the better the filler loading property. EVA resin, EMA resin, EEA resin, and EBA resin are vinyl acetate (VA), methyl acrylate (MA), ethyl acrylate (EA) and butyl acrylate (BA), respectively. ) Should be at least 15 wt% or more to express high filler loading. Since VA is weak in heat and poor in heat aging, it is preferable to crosslink to require high heat resistance using EVA resin.

In the present invention, the above-described polypropylene resin, styrene block copolymer resin, polyolefin copolymer resin and acid anhydride graft modified resins may be used in combination, and such modified resins may be 10 to 40 weight of the total resin mixture 100. Use in%. If the content of the modified resin is less than 10% by weight, it is difficult to provide sufficient compatibility with the inorganic material, and thus it is difficult to compensate for the decrease in tensile strength and wear resistance due to the filling of the inorganic material. It is so excessive that tensile strength is very good, but elongation decreases rapidly.

The modified resin is a grafted acid anhydride such as maleic anhydride as a polar group in the polymer main chain, and the grafted acid anhydride acts as a polar group such as an inorganic filler to enhance compatibility between the resin and the inorganic filler. Therefore, the higher the graft rate, the higher the effect can be seen in a small amount, so the amount of modified resin is adjusted according to the content of the inorganic filler and surface treatment.

In the present invention, a modified resin in which maleic anhydride is grafted at 0.1% by weight to 2% by weight is mainly used as the acid anhydride. In the production of modified resin, there is a method of adding acid anhydride in advance during polymer polymerization and grafting at synthesis, and there is a method in which polymer is grafted while adding an acid anhydride and a peroxide initiator in an extruder. The former method is capable of relatively uniform graft, but there is a limit to increasing the graft rate. The latter method may increase the graft rate to some extent, but has a disadvantage in that a gel (gel) that is concurrently grafted is well managed. In addition, these modified resins are often diluted and sold in virgin paper as needed.

In the present invention, the metal hydrate is preferably used alone or in combination with magnesium hydroxide, calcium hydroxide, zinc borate, etc., in which the dehydration temperature is higher than the general extrusion processing temperature of the polypropylene resin, and 50 parts by weight based on 100 parts by weight of the resin mixture. It is preferable to use from 200 parts by weight. When the content of the metal hydrate is less than 50 parts by weight, the flame retardancy is unsatisfactory, and when it exceeds 200 parts by weight, the physical properties and the extrusion processability tend to decrease rapidly.

More preferably, the surface treated with a surface treatment agent having a polar group or the like is preferably used. When using the surface treated without a surface treatment, an appropriate compatibilizer may be added in combination.

In addition, if necessary, any one or a mixture of two or more selected from flame retardant aids, antioxidants, lubricants, compatibilizers, processing oils, inorganic fillers, colorants, and crosslinking aids may be further added to the flame retardant resin composition of the present invention. It is not limited so long as it is conventionally used, the content is also not limited because it can be selectively used in a range that does not impair the physical properties.

The electric wire coated with the flame-retardant resin composition according to the present invention is also included in the scope of the present invention. Such wires can be usefully used as automotive wires.

In order to prepare the flame retardant resin composition of the present invention, a continuous mixer such as a single screw extruder, a twin screw extruder, or the like is continuously manufactured, or a banbury mixer, a kneader, and a kneader. A batch type kneader such as a roll mill can be manufactured in a batch type, and in terms of productivity, it is preferable to use a continuous kneader, but in terms of kneading, a batch kneader is preferable. Batch kneading machine has a relatively low production rate, but the dispersibility of the resin and the inorganic flame retardant is good, even if the content of the inorganic flame retardant is high, there is an advantage of less physical degradation.

Particularly, when the inorganic flame retardant content exceeds about 60%, a batch kneader is advantageous over the continuous kneader. In the case of preparing a resin composition having an inorganic flame retardant content of more than about 60% in a continuous kneader, the inorganic flame retardant may be divided into a hopper, a first side feeder and a second side feeder of an extruder. Although there is a risk of uneven dispersibility, the inorganic flame retardant may be divided into two extrusion operations, but in this case, the productivity is lowered and the physical properties of the resin due to the thermal history are not preferable. The continuous kneader has a higher compression ratio (CR) of the screw and a larger length / diameter (L / D) of the screw, and the co-rotating and reverse rotation (for a twin screw extruder). Counter rotating screw can be used, and if the screw is made up of segments, the kneading block and the conveying block can be arranged properly to achieve the optimal screw configuration (SC). use.

As described above, the resin composition according to the present invention is used by mixing a polypropylene resin, a high molecular weight styrene copolymer resin, a polyolefin copolymer resin and their modified resins at an appropriate ratio, and non-halogen By suitably combining the metal hydrate which is a flame retardant, the extrusion processability of an electric wire is provided more than or equal to the conventional crosslinked polyvinyl chloride (PVC) resin for automobile wires, and the heat resistance is carried out without crosslinking. It provides an effect that can be given more than or equal to the balance.

In addition, the resin composition of the present invention is an environmentally friendly flame-retardant resin composition that generates little smoke during combustion and does not generate harmful halogen gas and environmental hormone substances, and thus, polyvinyl chloride (PVC) resin and crosslinked polyolefin (PO), which are used in conventional automotive wires. ) It can directly replace flame-retardant resins, and it is possible to use it in various fields such as electric wires for electric devices, as well as in most fields where environmental destruction and hazard problems are raised.

The resin composition of the present invention is more effective in wires having an insulation thickness of 0.2 mm or less. In addition, the resin composition of the present invention has high heat resistance at high temperature without crosslinking because polypropylene resin, which is an eco-friendly general-purpose polymer with high melting temperature, is used as a main raw material and the melt flow is controlled by a high molecular weight styrene-based block copolymer resin. Not only is it high, but there are also benefits in terms of resource reuse and economics.

Hereinafter, the present invention will be described by way of example for specific description of the present invention, but the present invention is not limited to the following examples.

The resin compositions of Examples and Comparative Examples of the present invention were prepared in a twin screw extruder, which was a continuous kneader, and the PVC resin composition of Comparative Example 1 was prepared in a single screw extruder. In addition, the resin composition of each example was extruded into an electric wire to evaluate the physical properties and the extrusion processability of the electric wire coating material.

The physical properties of wire covering materials were evaluated in accordance with ES 91110-05, an integrated standard for automotive wires of H, a domestic automobile maker, and ES 91110-05 was tested by KS C 3004 (rubber and plastic insulated wire test method) and KS C 3311 (Automotive). Low voltage wire test method).

Tensile strength is over 1.05kg / ㎠ and elongation is over 150%, according to ES 91110-05 5.1, and heat resistance I (long-term heat resistance) is time to bend after heating at 150 ℃ for 240 hours and bend 1,000V in water. For more than 1 minute, comply with 6.8 of ES 91110-05, and heat resistance II (short-term high temperature heat resistance) is harmful if left unheated for more than 16 hours at room temperature after heating for 30 minutes at 200 ° C and bending 6 times or more on the same bar with the outer diameter of the wire. No cracking occurs in accordance with 6.9 of ES 91110-05, and the flame retardancy test in accordance with 6.11 of ES 91110-05 as a horizontal test, which shall self-extinguish within 15 seconds of combustion. Abrasion resistance was measured according to 6.12 (wear resistance test 1) of ES 91110-05 and 6.13 (wear resistance test 2) of ES 91110-05. Abrasion resistance test1 was made by contacting 150 g wear tape of KS L 6002 (abrasion cloth) to a sample of about 900 mm in length, applying a load of 230 g, and then moving the wear tape at a speed of 1,500 mm / min. The tape length until contact was measured. After measuring one point, move the sample by 25 mm and rotate it clockwise by 90 ° to fix it. Perform the previous test and re-average the measured value below the average value out of the eight measured values as the wear resistance value. Should be at least Abrasion resistance test 2 fixed one end of a sample of about 750 mm in length and applied it with a load of 1,500 g on the other side, and fixed it.The tip was contacted with a metal flanger with a 90 ° V-shaped blade of R 0.125 mm to 510 g ( 5N) was loaded and the metal flanger was reciprocated at a distance of 10 ± 2 mm at a speed of 50 to 60 times / min to measure the number of round trips until the blade contacted the conductor. After measuring one point, move the sample 100mm, rotate it by 90˚, fix it, and perform the previous test.Measure 4 times for one sample, make the minimum value as the wear resistance value, and be at least 100 times.

Extrusion processability measured the maximum extruded flux until the surface felt by hand when the wire was extruded was not rough or no roughness occurred when viewed with a magnifying glass of 10x magnification. Rate this good.

In terms of eco-friendliness, smoke density and halogen content were measured and referenced because they are not specified in the conventional PVC automotive cable standards. Smoke density was measured by a flaming method with a sample thickness of 0.5 mm according to ASTM E662, and halogen content was measured by IEC 754-1.

The PVC resin composition of Comparative Example 1 had a cylinder temperature gradient C1 = 150 ° C, C2 = 160 ° C, C3 = 150 mm in diameter, screw / length L / D (length / diameter) = 30, and CR = 2.9. At the temperature of 170 ° C, C4 = 180 ° C, C5 = 180 ° C, cylinder head temperature = 185 ° C and dice temperature = 185 ° C, with screw rotation speed = 50 rpm (round per minute) The kneaded mixture is cooled by passing it through a cooling water tank, dried with high pressure air, and cut and dried into pellets having a diameter of 2 to 3 mm and a length of 3 to 5 mm in an automatic cutter. Cylinder temperature gradient C1 = 165-175 ° C, C2 = 175-185 ° C, C3 = 185-195 ° C, C4 = 190-200 ° C in a single screw extruder with a diameter of 50 mm, screw thread L / D = 28, CR = 2.6 The cover thickness is 0.2 mm and the outer diameter is 1.2 mm, with the extrusion of screw head rotation speed = 40 to 70 rpm at the cylinder head temperature of 190 ~ 200 ℃ and die temperature of 190 ~ 210 ℃. Was prepared.

The resin compositions of the remaining comparative examples and examples were cylinder temperature gradients C1 = 140 to 170 ° C, C2 = 150 to 190 ° C, C3 = 160 to 210 in a twin screw extruder with a diameter of 40 mm, screwed L / D = 38, CR = 2.8. Cool the molten mixture by kneading under the condition of screw rotation speed = 200 rpm at the temperature of ℃, C4 = 170 ~ 220 ℃, cylinder head temperature = 170 ~ 220 ℃ and die temperature = 170 ~ 215 ℃. After removing the water with high pressure air, cut it into pellets of 2 ~ 3 mm in diameter and 3 ~ 5 mm in length by automatic cutting machine and dried it. Cylinder temperature gradient C1 = 150 ~ in wire extruder same as PVC resin. Screw rotation speed = 40 ~ at a temperature of 190 ° C, C2 = 160 ~ 200 ° C, C3 = 170 ~ 210 ° C, C4 = 180 ~ 230 ° C, cylinder head temperature = 180 ~ 230 ° C and die temperature = 180 ~ 220 ° C Extrusion was carried out under the condition of 70 rpm to prepare a wire having a coating thickness of 0.2 mm and a finished outer diameter of 1.2 mm.

The electric wire coated with the crosslinked polyvinyl chloride (PVC) resin composition of Comparative Example 1 and the crosslinked polyolefin (PO) resin of Comparative Example 2, which required physical property supplementation by crosslinking, was prepared through a crosslinking process by separate electron beam irradiation. . The cross-linking by electron beam irradiation takes a large volume and generates radiation elements when accelerating electrons. Therefore, the extruded wires are placed inside the electron beam irradiator except that the installation cost is high. It can be cross-linked evenly with high speed, so it is very efficient and highly productive process compared to general cross-linking which is difficult to produce and slow in production. The electron beam irradiation determines the irradiation dose, which is the optimal crosslinking start energy, in consideration of the thickness of the coating and the passage speed of the extruded wire passing through the electron beam irradiation apparatus, that is, the residence time of the electron beam. In operating the electron beam irradiator, the voltage determines the thickness of the accelerated electron beam infiltrating the coating material, and the current determines the dose of the exposed electron beam. Therefore, the thicker the coating thickness, the higher the pressurized voltage and the shorter the residence time. Set the higher the current. However, since there are technical limitations in increasing the capacity of the pressurized voltage of the electron beam accelerator, a product with a very high coating thickness does not sufficiently transmit the electron beam through the coating layer. Therefore, irradiation crosslinking by an electron beam is not excessively thick. It is the most efficient to apply to electric wire or appliance wire.

From the material point of view, the polymer material is generally crosslinked and decomposed at the same time when irradiated with electron beams. Most polyolefin resins undergo crosslinking reactions preferentially, but PVC resins and polypropylene resins decompose preferentially. Also, polyfunctional monomers such as TMPTMA and TAIC, which easily crosslink, may be added to facilitate crosslinking even at a low radiation dose. These polyfunctional monomers can reduce energy consumption by significantly reducing the radiation dose when applied to polyolefin resin which can be crosslinked by electron beam irradiation.

The physical properties of Comparative Example 1 and Comparative Example 2 of the present invention were subjected to a cross-linking process by electron beam irradiation, and the irradiation conditions of the electron beam were the electron beam accelerators having a capacity of 1 MeV (mega electron voltage). (mega radiation), and Comparative Example 2 was the irradiation dose of 12 Mrad.

[Comparative Examples 1 to 9, Examples 1 to 6]

The resin compositions and wire properties of the comparative examples and examples are summarized in the following Tables 1, 2, 3, and 4, and the results of the composition and action of each example were evaluated by the resin composition and the wire properties of each example.

As shown below, Table 1 shows the resin composition of the comparative example, Table 2 shows the wire physical properties of the comparative example, the resin composition and wire properties of the specific examples of the present invention are shown in Table 3 and Table 4.

TABLE 1

* 1: suspension polymerization PVC, degree of polymerization = 1,300

* 2: Homo-PP, MI = 1.5 (230 ℃, 2.16kg)

* 3: Impact Co-PP (PP + EPR), MI = 40 (230 ℃, 2.16kg), high fluidity

* 4: MA modified PP, MI = 3 (230 ° C., 2.16 kg), MA = 0.2%

* 5: MA modified PP, MI = 60 (230 ℃, 2.16kg), high fluidity, MA = 0.2%

* 6: High molecular weight SEPS, Styrene = 30%, MI = no flow (230 ℃, 2.16kg), 5% solution viscosity = 300 mPa.s (30 ℃, Toluene)

* 7: SEP, Styrene = 36%, MI = 1.8 (200 ℃, 10kg)

* 8: MA modified SEBS, Styrene = 20%, MI = 2 (230 ℃, 2.16kg), MA = 2%

* 9: High molecular weight MA modified SEPS, Styrene = 30%, MI = no flow (230 ℃, 2.16kg), 5% solution viscosity = 50 mPa.s (30 ℃, Toluene), MA = 0.3%

* 10: EVA, MI = 3.0 (190 ℃, 2.16kg), VA = 25%

* 11: HDPE, MI = 1.0 (190 ℃, 2.16kg)

* 12: EEA, MI = 1.0 (190 ℃, 2.16kg), EA = 15%

* 13: VLDPE, MI = 1 (190 ℃, 2.16kg), octene copolymer

* 14: VLDPE, MI = 0.5 (190 ℃, 2.16kg), octene copolymer

* 15: MA modified LLDPE, MI = 23 (190 ℃, 2.16kg), MA = 2%

* 16: Magnesium hydroxide, average particle size = 1.6 micron, silane coated

* 17: Aluminum trioxide, Average particle size = 1.5 micron, stearic acid coated

* 18: Flame retardant, decabromodiphenyloxide (DBDPO)

* 19: Hydrotalcite stabilizer

* 20: Antioxidant ratio; Iganox 1010 / Iganox168 / MD1024 = 0.7 / 0.7 / 0.6

* 21: Average particle size = 2 micron, stearic acid coated

* 22: Lubrucant ratio; LC Wax 102N (Lion Chemical Co., Ltd.) / Ca-St = 1.0 / 1.0

* 23: Trimethylpropanetrimethacrylate (TMPTMA)

* 24: Trioctyltrimellitate (TOTM)

TABLE 2

The resin composition of Comparative Example 1 of Table 1 is a general composition of a crosslinked polyvinyl chloride (PVC) resin for automobile wires, which is conventionally used. As shown in the electrical properties of Comparative Example 1 of Table 2, the toxic halogen content and the smoke density are Although it is very high and does not satisfy the heat resistance I, it is excellent in flame retardancy and the wire extrusion speed is about 650 meters per minute, which shows very high extrusion processability.

The resin composition of Comparative Example 2 is a general composition of a halogen flame retardant crosslinked polyolefin (PO) resin for automobile wires, which is conventionally used. As shown in the electrical properties of Comparative Example 2 of Table 2, the heat resistance is superior to that of the crosslinked PVC resin. Although the overall satisfaction is satisfied, the extrusion processability is remarkably insufficient at half the level of the crosslinked PVC resin, and the halogen content and the smoke density are very high.

The composition of Comparative Examples 3 to 9 is an eco-friendly material, in which a magnesium hydroxide, which is a non-halogen flame retardant, is added to a polypropylene resin, a styrene block copolymer resin, and a polyolefin copolymer resin, and the halogen content is less than 0.5%. It is far below, and smoke density is below 100. It can be seen that the level satisfactorily satisfies the halogen content of 0.5% or less and the smoke density of 150 or less, which are standards of non-halogen materials for power or communication cables. However, the balance between physical properties and wire extrusion is still insufficient.

In Comparative Example 3, the polypropylene resin having a low melt index was very high (90% by weight), a small amount of high molecular weight styrene block copolymer resin was added in 3% by weight, and the polyolefin resin was 7% by weight. Although it is composed of a large amount, the tensile strength is very high, but the elongation is insufficient, in particular, the extruded flux of the wire is very insufficient compared to the polyvinyl chloride resin, and the short-term high temperature heat resistance is not satisfied. When the content of the polypropylene resin is too high and the content of the styrene block copolymer resin and the polyolefin copolymer resin having good filler loading property is too small, it can be seen that there is insufficient balance of physical properties. In addition, if the content of the high molecular weight styrene block copolymer resin is too small, it can be seen that it is difficult to control the melt flow at high temperature.

In Comparative Example 4, 40 wt% of the polypropylene resin having a high melt index was composed of very low polypropylene resin, 40 wt% of the styrene block copolymer resin and 20 wt% of the EEA resin as the polyolefin copolymer resin. In the case of addition, 25% by weight of the high molecular weight styrenic block copolymer resin is contained in the styrenic block copolymer resin. As the content of the resin with good filler loading is high, the elongation is good, but the wear resistance is insufficient. Short-term high temperature heat resistance is satisfactory due to the high content of high molecular weight styrene block copolymer resin, but the improvement of extrusion flux due to high flow polypropylene resin is also achieved due to the high content of high molecular weight styrene block copolymer resin. Rather finely improved but still insufficient. However, it is understood that the reduction of the combustion time gives the EEA resin the effect of increasing the flame retardancy by promoting the formation of char, which is a combustion product during combustion.

As shown in the test results of Comparative Example 3 and Comparative Example 4, if the content of the polypropylene resin is too high, the tensile strength is good but the elongation is largely reduced. On the contrary, if the content of the polypropylene resin is too small, the elongation is increased but the tensile strength is increased. The loss is large. In addition, if the content of high molecular weight styrene block copolymer resin is too small, it will not satisfy the short term high temperature heat resistance. On the contrary, if the content of high molecular weight styrene block copolymer resin is too high, the short term high temperature heat resistance will be improved, but the extrusion processability will be reduced. You can see the big picture. Therefore, in consideration of the balance with other resins should be configured in an appropriate amount.

Comparative Example 5 is composed of 36 wt% SEP resin and low melt flow polyolefin copolymer resin in a suitable amount of polypropylene resin, and short-term high temperature heat resistance as there is no high molecular weight styrene block copolymer resin. This is unsatisfactory and lacks elongation and extrudability. The decrease in elongation rate is thought to be due to the SEP resin having a high styrene content as a hard block.

Comparative Example 6 is a composition consisting of 5% by weight of polypropylene resin having a high melt index in a polypropylene resin of 70% by weight, excellent physical properties but insufficient extrusion of wire, high molecular weight styrene block air As there is no coalescing resin, short-term high temperature heat resistance is unsatisfactory. Comparative Example 7 is a composition consisting of 70% by weight of the polypropylene resin having a high melt index in the 80% by weight of polypropylene resin, the extrusion processability is very good, but the elongation is insufficient, and also short-term high temperature heat resistance is not satisfied.

As shown in the test results of Comparative Example 6 and Comparative Example 7, polypropylene resin having a high melt index in the polypropylene resin has a very positive effect on the wire flux of the wire. When the content is too small, the improvement of the extrudability is insignificant. If the content is too high, the extrudability is very good, but it is important to combine the proper content because the deterioration of physical properties is rapid. In addition, it can be seen that short-term high temperature heat resistance is not satisfied without high molecular weight styrene-based block copolymer resin.

Comparative Example 8 and Comparative Example 9 are 40 parts by weight and 220 parts by weight of magnesium hydroxide as a flame retardant, respectively. As can be seen from the results of Table 2, when the content of magnesium hydroxide is small, the physical properties and the extrusion flux are improved. Flame retardancy cannot be satisfied and short term high temperature heat resistance is also unsatisfactory. On the contrary, when the content of magnesium hydroxide is excessive, the flow of resin is very low to satisfy the short-term high temperature heat resistance and flame retardancy may lead to PVC resin, but the physical properties as well as the extruded flux and wear resistance are serious.

As described above, the resin compositions of Comparative Examples 2 to 9 had unsatisfactory levels of balance between physical properties and extrudability compared with conventional crosslinked PVC resins and crosslinked polyolefin resins for automotive wires.

Therefore, in the present invention, in order to balance the physical properties such as the extrusion properties of crosslinked polyvinyl chloride (PVC) resin for automobile wires and the heat resistance of the crosslinked polyolefin resin, which was not satisfied by the conventional technology, the examples of Tables 3 and 4 were examined. As shown in Tables 3 and 4, heat resistance is achieved without adjusting crosslinking by adjusting the modified resin modified with high flow polypropylene resin, high molecular weight styrene block copolymer resin and acid anhydride at an appropriate ratio. To satisfy the level of crosslinked polyolefin resin, the extrusion processability could be made comparable to the PVC resin for automobile wires.

TABLE 3

* 1: Homo-PP, MI = 1.5 (230 ℃, 2.16kg)

* 2: Impact Co-PP (PP + EPR), MI = 40 (230 ℃, 2.16kg), high fluidity

* 3: MA modified PP, MI = 3 (230 ° C., 2.16 kg), MA = 0.2%

* 4: MA modified PP, MI = 60 (230 ℃, 2.16kg), high fluidity, MA = 0.2%

* 5: MA modified PP, MI = 120 (230 ℃, 2.16kg), high fluidity, MA = 0.2%

* 6: High molecular weight SEPS, Styrene = 30%, MI = no flow (230 ℃, 2.16kg), 5% solution viscosity = 300 mPa.s (30 ℃, Toluene)

* 7: High molecular weight SEPS, Styrene = 30%, MI = no flow (230 ℃, 2.16kg), 5% solution viscosity = 670 mPa.s (30 ℃, Toluene)

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* 9: High molecular weight MA modified SEPS, Styrene = 30%, MI = no flow (230 ℃, 2.16kg), 5% solution viscosity = 50 mPa.s (30 ℃ Toluene), MA = 0.3%

* 10: VLDPE. MI = 1 (190 ℃, 2.16kg), octene copolyme

* 11: EEA. MI = 1.0 (190 ° C., 2.16 kg), EA = 15%

* 12: Magnesium hydroxide, average particle size = 1.6 micron, silane coated

* 13: Magnesium hydroxide, average particle size = 1.6 micron, not coated

* 14: Melamine Cyanurate, average diameter = 2.0 micron, stearic acid coated

* 15: Dimethyl methylvinyl siloxane> 60%

* 16: Silane coupling agent

* 17: Paraffinic oil

* 18: Antioxidant ratio; Iganox 1010 / Iganox168 / MD1024 = 0.7 / 0.7 / 0.6

* 19: Lubrucant ratio; LC Wax 102N (Lion Chemical Co., Ltd.) / Ca-St = 1.0 / 1.0

TABLE 4

As shown in Table 3 and Table 4, all of the embodiments according to the present invention have the same properties as the extruded wire flux of the wire, which is equal to or higher than that of the conventional crosslinked PVC resin, and satisfies short-term high temperature heat resistance even without crosslinking. It can be seen that the integrated specification of the automobile wire of H company, a domestic automobile maker, is sufficiently satisfied beyond the conventional crosslinked polyolefin (PO) resin.

The eco-friendly resin composition of the embodiment is slightly inferior in flame retardancy compared to PVC resin because the inorganic flame retardant is added to about 100 parts by weight of the resin, but excellent physical properties and extrusion processability, smoke density and halogen content is It is much less than PVC resin for automotive wire. In addition, even without crosslinking, it exhibits the same physical properties as those of the conventional crosslinked polyolefin flame retardant resin, and it is understood that extrusion processability is much superior.

Example 1 is a composition consisting of 70% by weight of polypropylene resin, 15% by weight of high molecular weight styrene-based block copolymer resin and 15% by weight of polyolefin resin, in order to improve extrusion processability in polypropylene resin As a highly flexible polypropylene resin, 30 wt% of a modified polypropylene resin having a melt index of 120 at a load of 2.16 kg at 210 ° C is included. The flame retardant includes 100 parts by weight of magnesium hydroxide surface-treated with a silane coupling agent. This composition shows physical properties and extrusion processability equivalent to or higher than that of the crosslinked PVC resin and the crosslinked polyolefin resin, as can be seen from the wire physical properties of Example 1.

Example 2 is a composition consisting of 75% by weight of polypropylene resin, 10% by weight of high molecular weight styrenic block copolymer resin, and 15% by weight of polyolefin resin, 40 parts by weight of highly modified modified polypropylene resin % Is included. In addition, by increasing the content of the silicone-based flame retardant aid, even if the amount of magnesium hydroxide is slightly reduced, the flame retardancy of the equivalent level is shown. Example 2 shows the effect of improving the extrusion processability as the content of the highly flexible polypropylene resin is high.

Example 3 is a polyolefin resin in the resin configuration of Example 1 as the ELD resin instead of VLDPE resin, it can be seen that the flame retardancy is slightly improved than Example 1. As in Comparative Example 4, it can be seen that EEA resin is more effective in flame retardancy. However, tensile strength and wear resistance tend to decrease slightly.

Example 4 is a composition in which the magnesium hydroxide and the silane coupling agent without surface treatment are added instead of the magnesium hydroxide surface treated with the silane in the structure of Example 1, except that the extrusion processability is slightly reduced. Similar physical properties can be seen.

Example 5 is a composition consisting of 70% by weight of polypropylene resin, 10% by weight of styrene block copolymer resin of high molecular weight, 10% by weight of modified styrene block copolymer resin, and 10% by weight of polyolefin resin. It contains 40% by weight of high-flow polypropylene resin and 40% by weight of modified resin, and reduces the content of magnesium hydroxide without surface treatment to 80 parts by weight, instead of combining melamine cyanate and silicon as a flame retardant adjuvant, As a result of using the ring agent, it was found that the physical properties and the extrusion processability were equal to or higher than those of the crosslinked PVC resin and the crosslinked polyolefin resin.

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In more detail, the composition of the examples is 40 parts by weight to 80% by weight of the polypropylene-based resin of the examples alone or in combination with a homo PP resin, a block PP copolymer resin, a random PP copolymer resin and a modified PP resin. It is better to use wealth.

In the embodiment, as the highly flexible polypropylene resin, the melt index is preferably at least 10 or more at a load of 2.16 kg at 230 ° C., and 10 wt% to 40 wt% based on the total resin total 100 may be used. When the content of the highly flexible polypropylene resin is 10% by weight or less, the effect of improving the extrusion processability is insufficient, and when the content is 40 parts by weight or more, the extrusion processability is better but the physical property decreases significantly.

Examples of the high molecular weight styrenic block copolymer resin include SBS resin, SIS resin, SBBS resin, SEBS resin, SEP resin having a styrene content of 30 wt% or less and a 5% solution viscosity of at least 300 mPas of toluene solvent at 30 ° C. , 5 parts by weight to 20 parts by weight of the SEPS resin and the modified styrene-based block copolymer resin alone or in combination may be used. If the amount of the high molecular weight styrene-based block copolymer resin is 5 parts by weight or less, it is difficult to satisfy the short-term high temperature heat resistance.

In the embodiment, it is preferable to use 10 parts by weight to 30 parts by weight of the polyolefin copolymer resin alone or in combination with VLDPE resin, EVA resin, EMA resin, EEA resin, EBA resin and modified polyolefin copolymer resin. When the content of the polyolefin copolymer is 10 parts by weight or less, it is difficult to prevent the reduction of the elongation rate due to the filling of a large amount of inorganic material, and when the content of the polyolefin copolymer is 30 parts by weight or more, the decrease in tensile strength is large.

In the embodiment, as the modified resin, 10 parts by weight to 40 parts by weight of a modified polypropylene resin modified with an acid anhydride or the like, a modified styrene block copolymer resin, a modified polyolefin copolymer resin, or the like may be used alone or in combination. If the content of the modified resin is 10 parts by weight or less, it is difficult to provide sufficient compatibility with the inorganic material, and it is difficult to compensate for the decrease in the tensile strength due to the filling of the inorganic material.If it exceeds 40 parts by weight, the compatibility with the inorganic material is too excessive and the tensile strength is too high. Is very good, but the elongation decreases rapidly.

As the metal hydrate flame retardant of the embodiment, as known in the prior art, 50 parts by weight to 200 parts by weight of magnesium hydroxide coated with stearic acid or a silane-based surface treatment agent at an average particle diameter of 1 to 5 m and a specific surface area of 2 to 10 m 2 / g. It is good to use. If the content of the metal hydrate flame retardant is 50 parts by weight or less, the flame retardant effect is small, if it is 200 parts by weight or more, the flame retardancy is very good, but the tensile properties and extrusion processability is significantly reduced.

Claims (9)

50 to 80% by weight of polypropylene resin, 30% by weight or less of styrene, 5 to 20% by weight of high molecular weight styrene block copolymer resin having a solution viscosity of 300 mPas or more at 5 ° C of toluene solvent at 30 ° C. Resin mixture consisting of 10 to 30% by weight of a resin mixture, The modified resin in the form of an acid anhydride is grafted to at least one resin selected from polypropylene resin, high molecular weight styrene block copolymer resin, and polyolefin copolymer resin in 100% by weight of the resin mixture. % By weight, At least one selected from polypropylene resin and modified resin of polypropylene resin in 100% by weight of the resin mixture is a highly flexible polypropylene resin having a melt index of 40 g / 10 minutes or more at a load of 2.16 kg at 230 ° C. ~ 40% by weight, Eco-friendly flame-retardant resin composition excellent in extrusion processability and heat resistance containing 50 to 200 parts by weight of metal hydrate with respect to 100 parts by weight of the resin mixture. The method of claim 1, The polypropylene resin is any one or two or more blends selected from homo polypropylene resin, block polypropylene copolymer resin, random polypropylene copolymer resin, random polypropylene terpolymer copolymer resin and acid anhydride graft modified resin thereof Eco-friendly flame retardant resin composition with excellent extrusion processability and heat resistance. The method of claim 1, The high molecular weight styrene-based block copolymer resin is styrene butadiene styrene resin, styrene isoprene styrene resin, styrene butadiene butylene styrene resin, styrene ethylene butylene styrene resin, styrene ethylene propylene styrene resin and acid anhydride graft modified resin Eco-friendly flame retardant resin composition with excellent extrusion processability and heat resistance of any one or two or more blends selected from. The method of claim 1, The polyolefin copolymer resin is selected from ultra low density polyethylene resin, vinyl acetate ethylene copolymer resin, methyl acrylate copolymer resin, ethyl acrylate copolymer resin, butyl acrylate copolymer resin and acid anhydride graft modified resin Eco-friendly flame-retardant resin composition excellent in extrusion processability and heat resistance of any one or two or more blends. The method of claim 1, The modified resin is extrudeable using any one or two resins selected from polypropylene resin, styrene block copolymer resin, and polyolefin copolymer resin, each of which is grafted with 0.1% to 2% by weight of maleic anhydride. Eco-friendly flame retardant resin composition with excellent heat and heat resistance. The method of claim 1, The metal hydrate has an average particle diameter of 1 to 5 ㎛, specific surface area of 2 to 10 m 2 / g, and any one or two or more selected from magnesium hydroxide, calcium hydroxide, zinc borate coated or uncoated with stearic acid or a silane-based surface treatment agent. Eco-friendly flame retardant resin composition with excellent extrusion processability and heat resistance. The method according to any one of claims 1 to 6, The flame-retardant resin composition is an eco-friendly flame-retardant resin composition excellent in extrusion processability and heat resistance further adding any one or two or more mixtures selected from flame retardant aids, antioxidants, lubricants, compatibilizers, processing oils, inorganic fillers, colorants and crosslinking aids. . Wire coated with an environmentally friendly flame-retardant resin composition excellent in extrusion processability and heat resistance according to any one of claims 1 to 6. Wire coated with an environmentally friendly flame-retardant resin composition excellent in extrusion processability and heat resistance according to claim 7.