KR100896105B1 - Flame-retardant resin composition containing silicon dioxide nanoparticles - Google Patents

Abstract

The present invention relates to a flame retardant resin composition containing silicon dioxide nanoparticles. Specifically, the present invention discloses a non-halogen flame retardant resin composition comprising an olefin base resin, an inorganic flame retardant, and silicon dioxide nanoparticles. The flame retardant resin composition of the present invention has an advantageous effect of greatly improving workability and flame retardancy at the same time by the addition of silicon dioxide nanoparticles.

Silicon Dioxide, Nanoparticles, Flame Retardant, Resin Composition

Description

Flame-retardant resin composition containing silicon dioxide nanoparticles {FLAME-RETARDANT RESIN COMPOSITION CONTAINING SILICON DIOXIDE NANOPARTICLES}

The present invention relates to a non-halogen flame retardant resin composition with a nanometer scale silicon dioxide additive. More specifically, the flame retardant resin composition of the present invention is a composition in which a polyolefin-based polymer blend is used as the base resin and an inorganic flame retardant and a nanometer-scale silicon dioxide additive are reinforced therein.

Thermoplastic resins such as polyethylene, which are widely used as insulation materials for wires and heat shrink tubes, are combustible materials, so they easily catch fire and generate smoke containing a large amount of toxic gas when a fire occurs. In order to solve this problem of smoke, a conventional flame retardant insulating material such as polyvinyl chloride (PVC) having a bromine or a chlorine component, which is a halogen group element, is used. However, these halogen-based flame retardant insulation materials may cause safety problems in both manufacturing and use processes, and in particular, since they emit toxic gases such as dioxins during combustion, recently, flame-retardant insulation materials containing halogen elements such as PVC are used for environmental protection. Increasingly, regulations on the use of the

As a result, the industry has studied the possibility of flame retardant for various environmentally friendly materials to date, and the method of using a mixed metal hydroxide inorganic flame retardant as an alternative to the halogenated polymer resin has emerged. However, the polymer resin using the metal hydroxide flame retardant has the advantage that the char formation is smooth and the drip phenomenon that the combustion product melts does not occur, but the thermal stability of the metal hydroxide component is poor at the polymer resin processing temperature. There was a problem that the mechanical properties sharply deteriorated. In addition, when a filler is introduced to prevent a decrease in mechanical properties when using a metal hydroxide, there is a problem in that processability increases due to an increase in the viscosity of the polymer resin including the filler because the filler should be added in an excessive amount.

Therefore, the development of a non-halogen-based flame retardant resin composition having sufficient flame retardancy and not sacrificing mechanical properties such as tensile force is a field that still needs a steady study.

The technical problem of the present invention is to provide a non-halogen-based polymer resin composition having excellent flame retardancy and excellent workability when exposed to fire. An object of the present invention is to make such a non-halogen-based polymer resin composition be used as a material such as an instrument wire, a heat shrink tube, an electric wire insulation material, and a sheath.

As described above, in order to achieve the object of the present invention, in the present application, the base resin, the inorganic flame retardant, and the silicon dioxide having an average particle diameter of several tens to several hundred nanometers (hereinafter referred to as "silicon dioxide nanoparticles") are reduced. It provides a flame retardant resin composition comprising. The flame retardant resin composition of the present invention uses a polymer blend obtained by mixing 1 to 50% by weight of a polarized reactive olefin resin with 50 to 99% by weight of a polyolefin resin as a basic resin,

0 to 200 parts by weight of the inorganic flame retardant based on 100 parts by weight of the base resin blend, and 10 to 80 parts by weight of silicon dioxide nanoparticles.

In the flame retardant resin composition of the present invention, the average diameter of the silicon dioxide nanoparticles is preferably 50 to 200 nanometers.

The flame-retardant polymer resin composition of the present invention containing silicon dioxide nanoparticles improves physical properties such as tensile strength and elongation even when a small amount is used, so that the viscosity of the resin can be maintained well and the processability is excellent. In addition, the addition of silicon dioxide nanoparticles can reduce the amount of metal hydroxide flame retardant required to achieve a certain level of flame retardancy to a significant level than the prior art is an advantageous effect difficult to predict from the conventional theory.

The present invention will be described in more detail with reference to the following Examples. However, it is obvious that the present invention can be modified in various equivalent embodiments in addition to the embodiments according to such embodiments, and thus, the technical scope of the present invention is not limited to the ranges disclosed in the embodiments described below. Embodiment of the present invention is merely an example to help the average skilled person in the art.

The present invention is a flame retardant resin composition comprising a basic resin, an inorganic flame retardant, and silicon dioxide (hereinafter referred to as "silicon dioxide nanoparticles") having an average particle diameter of several tens to several hundreds of nanometers, which is an olefin resin blend.

The basic resin of the present invention is a polymer blend obtained by mixing 1 to 50% by weight of a polarized reactive olefin resin to 50 to 99% by weight of a polyolefin resin. The basic composition of the resin composition of the present invention further includes an inorganic flame retardant in an amount of 50 to 200 parts by weight based on 100 parts by weight of the base resin, and a silicon dioxide nanoparticle in an amount of 10 to 80 parts by weight based on 100 parts by weight of the base resin.

In the basic resin of the present invention, a polyolefin resin is a polymer polymerized from a monomer having an unsaturated double bond. The polyolefin-based resin is not limited to the following exemplary molecules, but block copolymers and randomness of high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, alphaolpephine having 3 to 15 carbon atoms. ) Copolymers, ethylene-vinyl acetate (EVA) copolymers, ethylene-ethyl acrylate copolymers, and ethylene-methyl acrylate copolymers. Examples of alpha-olefin block copolymers or irregular copolymers having 3 to 15 carbon atoms include, but are not limited to the following examples, copolymers of ethylene and 1-octene and copolymers of ethylene and 1-butene. In the case of the ethylene-vinyl acetate (EVA) resin of the polyolefin resin of the present invention, a polymer having a proportion of 10 to 40% by weight of the vinyl acetate monomer at the time of polymerization is suitable.

In the basic resin of the present invention, the polarized reactive olefin resin is a polymer mixture or a graft copolymer molecule thereof including a copolymer in which a polar functional group is introduced in a kraft form. The polarized reactive olefin resin of the present invention is preferably polyethylene, ethylene-vinyl acetate copolymer or ethylene-ethyl acrylate copolymer grafted with maleic anhydride or glycidyl methacrylate. Do. Specifically, a polymer in which maleic anhydride is introduced into the ethylene-vinyl acetate copolymer is more preferable.

In the basic resin of the present invention, the polyolefin-based resin is 50 to 99% by weight, and the polarized reactive olefin resin is 1 to 50% by weight. When the content of the polarized reactive olefin resin in the base resin is less than 1% by weight, it is difficult to improve the mutual affinity between the different resins. When the content is more than 50% by weight, the processability is improved due to the improvement of the mutual affinity. There is a problem of degradation.

As the inorganic flame retardant in the flame retardant resin composition of the present invention, it is preferable to use an antimony-based, metal hydroxide-based or silane-based flame retardant. In the present invention, the inorganic flame retardant is to use 50 to 200 parts by weight based on 100 parts by weight of the base resin. Inorganic flame retardants serve to facilitate the formation of char that forms a solid film upon combustion to improve flame retardancy. Specific examples of the inorganic flame retardant of the present invention include vinyl silane, magnesium hydroxide, and aluminum hydroxide. The magnesium hydroxide and aluminum hydroxide may be those having no surface treatment, or surface treated with fatty acids or aminopolysiloxanes. When the amount of the flame retardant is less than 50 parts by weight, which is the minimum value of the numerical limit regarding the content of the inorganic flame retardant of the present invention, the flame retardant effect described above cannot be obtained, and the extrusion process using the composition even when the amount of use exceeds 200 parts by weight. In addition to poor workability, the cost increases and becomes uneconomical.

In the flame-retardant resin composition of the present invention by adding a silicon dioxide (silicon dioxide nanoparticles) having a particle diameter of several tens to several hundred nanometers as an additive to improve the flame retardancy and processability. In the flame-retardant resin composition of the present invention, the silicon dioxide nanoparticles produce excellent effects even if only 10 to 80 parts by weight of a relatively small amount is added to 100 parts by weight of the base resin. In the resin composition of the present invention, when the silicon dioxide nanoparticles content is less than 10 parts by weight, the effect of improving flame retardant properties and processability is insignificant, and when the content of silicon dioxide nanoparticles is more than 80 parts by weight, disadvantages of deterioration in physical properties and processability There is this.

In the flame-retardant resin composition of the present invention, the silicon dioxide nanoparticles preferably have an average particle diameter of 50 to 200 nanometers, but when the diameter is less than 50 nanometers, problems in manufacturing technology of nanoparticles and an increase in price during product application The disadvantage is that it has an economic problem, and when the diameter exceeds 200 nanometers, there is a disadvantage that the beneficial effect that the nanometer-scale particles can have.

In the flame retardant resin composition of the present invention, the silicon dioxide is preferably non-reinforced silicon dioxide without reinforcing fibers and the like, and amorphous silicon dioxide may be used.

The resin composition of the present invention may further contain other additives in addition to the above components. Other additives include antioxidants, lubricants and processing aids. Specifically, the antioxidant is added to the thioester-based, phenol-based material or a mixture thereof in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the base resin. In addition, the lubricant and the processing aid is used from 0.5 to 10 parts by weight based on 100 parts by weight of the base resin.

As described above, the non-halogen flame-retardant resin composition of the present invention containing silicon dioxide nanoparticles has excellent processability and flame retardancy as compared to the flame-retardant resin composition of the prior art as described in the following examples, and thus, a polymer composition for an instrument line and a heat shrinkable tube, It has physical properties suitable for use in polymer materials such as high flame retardant non-halogen wires and sheaths that require vertical flame retardancy.

<Example>

The present invention will be described in more detail with reference to the following Examples. The average person skilled in the art to which the present invention pertains may change the present invention in various other forms in addition to the embodiments described in the following examples, and the following examples merely illustrate the present invention, and the scope of the technical spirit of the present invention is given below. It is not to be construed as limiting the scope of the examples.

Flame retardant resin compositions of Comparative Examples and Examples were prepared with the compositions shown in Table 1 below. All units in Table 1 are parts by weight, and are calculated based on 100 parts by weight of the base resin used in the resin composition. As the base resin used in the examples, a blend of 20% by weight of ethylene-vinyl acetate copolymer grafted with maleic anhydride was used relative to 80% by weight of ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate polymer of this basic resin was polymerized with the content of vinyl acetate monomer at 28 weight%, and maleic anhydride was grafted in the ratio of 2 weight part with respect to EVA resin.

As an inorganic flame retardant, magnesium hydroxide without surface treatment was used, and silicon dioxide nanoparticles were made of amorphous non-reinforced silicon dioxide having an average particle diameter of 50 to 200 nm. As other additives, a lubricant was used as a hydrocarbon, an antioxidant was a thioester compound, a phenol compound or a mixture thereof, and an acrylate was used as a crosslinking aid.

division Example (parts by weight) Comparative Example (parts by weight) One 2 One 2 Basic resin 100 100 100 100 Inorganic flame retardants 130 130 160 180 Silicon dioxide nanoparticles 30 50 ― ― Other additives Bow One One One One Antioxidant 2 2 2 2 Processing aid 3 3 3 3

As shown in Table 1, the resin composition of the comparative example was prepared to contain more magnesium hydroxide flame retardant than the example composition of the present invention.

Specimens for measuring processability and flame retardancy were prepared from these Examples and Comparative Examples resin compositions. The mixture was kneaded at 130 ° C. for 10 minutes using a roll mill, and then pressed for 20 minutes at 170 ° C. to prepare a specimen.

Machinability Evaluation

Tensile strength and elongation were measured and compared at room temperature for the Comparative Example and Example specimens according to the UL 224 standard.

Flame Retardant Rating

Flame retardant properties were measured using a cone calorimeter. The conical calorimeter measures the combustion characteristics by applying a heat flux of 50 kW / m ² to the specimen at 787 ° C, indicating the size of the flame, the magnetic flux, and the emissions of smoke and toxic gases. The specimen for the conical calorimeter was 100 mm x 100 mm in size and 3 mm thick.

Important evaluation items in flame retardancy evaluation using conical calorimeter are as follows.

Peak Heat Release Rate (PHRR): The maximum value of instantaneous heat generated per surface area of a sample. The smaller the value, the more flame retardant the material. Usually expressed in kW units.

Time to Peak Heat Release Rate (TTPHRR): Time to peak heat release rate, the higher the value, the more flame retardant the material. Usually expressed in units of seconds.

Time to Ignition (TTI): The time it takes for a flame to be observed on or on the surface of a specimen, the higher the value, the more flame retardant the material is. Usually expressed in units of seconds.

In the combustion experiment of the flame retardant resin composition using the inorganic flame retardant, the maximum heat release rate was observed twice, and thus the time at which the maximum heat release rate was reached was recorded separately. The flame retardancy and machinability test results for the specimens are summarized in Table 2.

division Example Comparative example One 2 One 2 Machinability Tensile Strength (kg / mm2) 1.31 1.48 1.010 1.23 Elongation (%) 403 355 310 262 Flame retardant First heat release rate (kW) 125 122 160 155 2nd maximum heat dissipation rate (kW) 85 78 165 163 First heat release rate arrival time (s) 128 131 105 120 Second heat release rate arrival time (s) 670 680 622 635 Ignition time (s) 70 75 58 60

Example specimens of the present invention incorporating silicon dioxide nanoparticles in Table 2 can be seen that there is a marked improvement in the tensile strength and elongation than the comparative example. Moreover, the silicon dioxide nanoparticles of the present invention have been shown to greatly improve the flame retardancy. Comparing the maximum heat release rate of the Examples and Comparative Examples in Table 2, it can be seen that the maximum heat release rate of the example side was significantly reduced, although the comparative sample contains more magnesium hydroxide flame retardant, in particular, 2 Maximum heat release rate was reduced by half. There was also a significant increase in the peak heat release rate and ignition time. On the other hand, although finer, when compared to Example 1 and Example 2, the flame retardant properties of Example 2 to which more silicon dioxide nanoparticles were added were observed to improve more than Example 1.

The resin composition of the present invention not only improved mechanical properties and improved workability, but also greatly improved flame retardancy. Such simultaneous increase in workability and flame retardancy has a large surface area and high hardness of silicon dioxide nanoparticles. It is difficult to explain only the basic physical properties of. Therefore, the simultaneous improvement of the flame retardancy and processability by the silicon dioxide nanoparticles is a new and advantageous effect that is theoretically difficult to predict.

Using the flame retardant resin composition of the present invention from this embodiment it can be confirmed that more excellent workability and flame retardancy than the flame retardant material of the prior art containing the same amount of inorganic flame retardant or a larger amount of inorganic flame retardant.

The terminology used in the description and examples herein is for the purpose of describing the invention in detail to those skilled in the art, and is intended to limit the scope of the invention in any particular sense or in the claims. It was not intended.

Claims (7)

To 100 parts by weight of the base resin mixed with a polyolefin resin and a polarizing reactive olefin resin, 50 to 200 parts by weight of an inorganic flame retardant; And 10 to 80 parts by weight of silicon dioxide, The base resin is a mixture of 50 to 99% by weight polyolefin resin and 1 to 50% by weight polarized reactive olefin resin, The silicon dioxide is flame retardant resin composition, characterized in that the average particle diameter of 50 to 200 nanometers. The method of claim 1, The polyolefin resin may be a high density polyethylene, a medium density polyethylene, a low density polyethylene, a linear low density polyethylene, a polypropylene, a block copolymer of an alpha olefin having 3 to 15 carbon atoms, and a random copolymer of an alpha olefin having 3 to 15 carbon atoms. And an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, and an ethylene-methyl acrylate copolymer, any one or more substances selected from the group consisting of flame retardant resin compositions. The method of claim 2, The alpha olefin is a flame retardant resin composition, characterized in that any one or more materials selected from the group consisting of a copolymer of ethylene and 1-octene and a copolymer of ethylene and 1-butene. The method of claim 1, The polarized olefin resins include polyethylene grafted with maleic anhydride, polyethylene grafted with glycidyl methacrylate, ethylene-vinyl acetate copolymer grafted with maleic anhydride, glycidyl At least one selected from the group consisting of ethylene-vinyl acetate copolymer grafted methacrylate, ethylene-ethylacrylate grafted maleic anhydride and ethylene-ethylacrylate copolymer grafted glycidyl methacrylate Flame retardant resin composition, characterized in that the substance. The method of claim 1, The inorganic flame retardant is a flame retardant resin composition, characterized in that any one or a mixture of two or more selected from vinylsilane, metal hydroxide and antimony flame retardant. The method of claim 2, Flame retardant resin composition, characterized in that the metal hydroxide is aluminum hydroxide or magnesium hydroxide. delete