JPH07100750B2 - Flame-retardant resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flame-retardant resin composition having excellent flexibility, heat resistance and mechanical strength.

[Prior Art and Problems Thereof] Various methods have been already known as means for improving the flame retardant property of the material used in the field of using an electric insulating material or an outer covering material made of a synthetic resin. There is.

Specifically, when the material used is a polyolefin such as polyethylene or polypropylene, halogen,
It is known to add phosphorus or an inorganic flame retardant.

However, when trying to achieve higher flame retardancy, generally, there is no drastic measure simply by increasing the amount of flame retardant used, and as a result, the flame retardance finally obtained. The resin composition causes a phenomenon that one or more of the properties such as mechanical strength, processability, flexibility, and cold resistance are significantly reduced.

An ethylene-ethyl acrylate copolymer (EEA) produced by the high pressure radical method is known as a synthetic resin capable of increasing the amount of flame retardant used, but this material has high mechanical strength at high temperatures. Not only shows a tendency to decrease, but its mechanical strength at room temperature is not yet sufficient.

This invention solves the problems in the prior art as described above, while maintaining high heat resistance and mechanical strength characteristics,
It is an object of the present invention to provide a flame-retardant resin composition that achieves high flame retardancy.

[Means for Solving the Problems] The present invention has been achieved as a result of various studies for achieving the above-mentioned object.

The structure of the present invention for achieving the above object is represented by the formula CH ₂ —CH ₂ (1) and the formula (However, in the formula, R ¹ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, or 3 to 20 carbon atoms.
Represents an alkenyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. R ² is
Hydrogen atom, alkyl group having 1 to 20 carbon atoms, alkenyl group having 3 to 20 carbon atoms, 3 to 3 carbon atoms
It represents a cycloalkyl group having 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. n is an integer of 0-20. ) And containing 0.001 to 45 mol% of the repeating unit represented by the formula (2), the polymer chain is linear, and the repeating unit represented by the formula (2) is Randomly arranged in the polymer chain, the following formula −0.87b + 120 <Tm <−0.87b + 135 (3) [wherein, b is the mol% of the repeating unit represented by the above formula (2)]
And Tm represents the melting point. ] 100 parts by weight of an ethylene-based copolymer having a melting point of 5,000 or more and a flame-retardant filler 10
It is a flame-retardant resin composition characterized by having about 160 parts by weight.

Here, specific examples of the unsaturated carboxylic acid or its ester which is a raw material used for the production of the ethylene-based copolymer include acrylic acid, methyl acrylate, ethyl acrylate, -n-propyl acrylate, and acrylic acid. Acid-i
-Propyl, acrylic acid-i-butyl, acrylic acid-n
-Hexyl, acrylic acid-n-octyl, acrylic acid-
2-ethylhexyl, benzyl acrylate, acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, -n-propyl methacrylate, methacrylic acid-
i-propyl, methacrylate-i-butyl, methacrylate-n-hexyl, methacrylate-n-octyl, 2-ethylhexyl methacrylate, phenyl methacrylate, ethyl α-chloroacrylate, methyl α-chloroacrylate, Examples thereof include α-phenyl acrylate, ethyl α-phenyl acrylate, 10-undecenoic acid and 10-undecenoic acid ester.

Among these, particularly preferred are lower alkyl acrylates, specifically, methyl acrylate, ethyl acrylate, acrylic acid-n-propyl, acrylic acid-i-propyl, acrylic acid-i-butyl, acrylic acid. -N-hexyl, acrylic acid-n-octyl, acrylic acid-2-ethylhexyl, methacrylic acid, methyl methacrylate, ethyl methacrylate, methacrylate-n-propyl, methacrylate-i-propyl, methacrylate-i
-Butyl, methacrylic acid-n-hexyl, methacrylic acid-n-octyl, 2-ethylhexyl methacrylate and the like.

In addition, in this invention, the ethylene-based copolymer used may contain another monomer unit having 3 or more carbon atoms.

Examples of the other monomer units include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-
Examples thereof include monomer units derived from methylbutene-1,4-methylpentene-1,1-decene and the like.

The ethylene-based copolymer can be produced by various methods, but preferably, the ethylene-based copolymer is produced by using a polymerization catalyst containing a transition metal compound and an organometallic compound as main components in the presence of a Lewis acid. And a random copolymer obtained by copolymerizing the above-mentioned unsaturated carboxylic acid or its ester.

Incidentally, a preferable method for producing an ethylene-based copolymer will be described.

As the Lewis acid, a halogen compound of a metal of Group I to V or Group XIII of the periodic table can be used, but preferably aluminum, boron, zinc, tin,
Magnesium, which is a halide of antimony, specifically, aluminum chloride, ethyl aluminum dichloride, ethyl aluminum sesquichloride, diethyl aluminum chloride, butyl aluminum dichloride, boron trichloride, zinc chloride, tin tetrachloride, alkyl tin halide, Examples thereof include magnesium chloride, antimony trichloride, antimony pentachloride and the like.

Of these, aluminum halide is preferably used, and aluminum trichloride is particularly preferable.

The Lewis acids may be used alone or in combination of two or more.

In this copolymerization reaction, it is preferable to bring the Lewis acid and the unsaturated carboxylic acid into contact with each other before bringing the monomer component into contact with the transition metal compound described later. It is advantageous to contact the Lewis acid with the unsaturated carboxylic acid in advance, because poisoning of the polymerization catalyst component obtained by contacting the transition metal compound and the organometallic compound can be alleviated.

As the transition metal compound, various chromium-containing compounds can be used. Specifically, carboxylate salts of chromium, carboxylate anhydride salts and their esters, ethers, ketone adducts, alkoxy compounds, chelate compounds, A π-substituted product, an aryl compound, a halide and the like can be used.

More specifically, chromium acetate, chromium-2-ethylhexanoate, chromium stearate, chromium benzoate, chromium carboxylic acid salts such as chromium naphthanoate, chromium carboxylate esters, ethers, Ketone adducts, tetramethoxychrome, tetraethoxychrome, tetra-n-butoxychrome, tetra-t-butoxychrome, triethoxychrome monochloride, diethoxydichrome dichloride, and other chromium alkoxy compounds, chromium triacetylacetonate, chromium tris. Chromium chelate compounds such as (2-methyl-1,3-butanedionate), chromium tris (1,3-butanedionate), chromium tris (trifluoroacetylacetonate), chromium tris (hexafluoroacetylacetonate), biscyclo Penta Chromium-π-complexes such as phenyl chrome, bisbenzene chrome, diphenyl benzene chrome, dihexamethyl benzene chrome, chromium aryl compounds such as diphenyl chrome, tetraphenyl tris tetrahydrofuran chrome, chrome trichloride, chrome tribromide, chrome triiodide , And one or more chromium compounds selected from chromium halides such as chromium dichloride and chromium dibromide.

Among the various chromium compounds as described above, those in the form of chromium carboxylate or chromium chelate compound are preferable. In the present invention, the term "carboxylic acid salt of chromium" includes the carboxylic acid-hydrate salt.

Examples of the organometallic compound include compounds derived from groups I to V of the periodic table, specifically, lithium, magnesium, zinc, cadmium, aluminum, boron, gallium, silicon, tin, antimony, bismuth, and the like. More specifically, for example, trimethyl aluminum, triethyl aluminum, triisopropyl aluminum, triisobutyl aluminum, dimethyl aluminum monochloride, diethyl aluminum monochloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, diethyl zinc, tributyl gallium, tetraethyl. Examples thereof include tin, diethyl magnesium and ethyl butyl magnesium.

Among these organometallic compounds, alkyl aluminum halides are particularly preferable.

Incidentally, if necessary, an activator can be used together with the chromium compound, and specifically, for example, a compound of magnesium or manganese, a carboxylate, alkoxide, organic phosphate of these metals, Organic phosphites and halides can be used.

As the solvent used for carrying out the copolymerization, it is possible to use aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons or halogenated hydrocarbons, and specifically, pentane and hexane. , Heptane, octane, decane, dodecane, kerosene, toluene, benzene, cyclohexane, ethylbenzene, chlorobenzene and ethylene dichloride.

The conditions for carrying out the copolymerization reaction are atmospheric pressure to 10
0 kg / cm ² G, preferably atmospheric pressure to 30 kg / cm ² G, −80 to 200
C., preferably in the range of -50 to 80.degree. C., and the conditions are appropriately set from the reaction time of 1 minute to 10 hours.

The ethylene-based copolymer thus obtained has a structure in which the ethylene-based copolymer obtained by the conventional high-pressure radical method does not have a main chain and is composed of all branched branched chains. Is linear, and the ester units are randomly bonded to the ethylene chain, which has a high melting point and a high degree of crystallization, and is generally excellent in heat resistance and mechanical properties.

The ethylene-based copolymer having such a molecular structure is represented by the formula (3) −0.87b + 120 <Tm <−0.87b + 135 (3) (wherein, b is mol% of the repeating unit represented by the formula (2).
And Tm represents the melting point. ) Has a melting point of the relationship shown by and the weight average molecular weight is
It is 5,000 or more, preferably 10,000 or more.

If the melting point of the ethylene-based copolymer deviates from the above range due to the relationship with the copolymer component, the heat resistance will be low and sufficient mechanical strength will not be obtained.

If the weight average molecular weight of the ethylene-based copolymer is less than 5,000, the mechanical strength of the molded product cannot be maintained.

Next, what is important in the present invention is that the flame-retardant resin composition contains the ethylene-based copolymer having the above-mentioned properties and the flame-retardant filler in a specific ratio.

As the flame-retardant filler, a flame-retardant filler can be used, and examples thereof include an inorganic metal compound-based flame retardant. As an inorganic compound flame retardant, aluminum hydroxide, basic magnesium carbonate, dolomite, zirconium hydroxide, calcium hydroxide, barium hydroxide, tin oxide hydrate, zinc metaborate, barium metaborate, tribasic lead sulfate, Examples thereof include antimony oxide, tin oxide, zirconium oxide, molybdenum oxide, magnesium oxide, barium carbonate, calcium carbonate, zinc carbonate, and basic lead sulfite.

In the present invention, when the flame retardant filler is mixed with the ethylene copolymer, the ethylene copolymer 10
The amount of the flame-retardant filler is preferably 10 to 160 parts by weight, especially 70 to 120 parts by weight when the main component is an inorganic metal compound flame retardant, relative to 0 parts by weight.

Outside this amount range, for example, when too little,
The effect of adding the flame-retardant filler is not sufficiently exerted, and on the contrary, when the amount used is too large, the mechanical strength originally possessed as a synthetic resin tends to decrease, which is not preferable.

The flame-retardant filler used here is arbitrarily selected from the above-mentioned various substances according to the purpose.

The flame-retardant filler used here is appropriately selected from various types as described above and used, but at this time, stearic acid, palmitic acid, oleic acid or a metal salt thereof, Wax, organosilane compound,
More preferable results can be obtained by using a material surface-treated with a material selected from organic boron compounds, organic titanate compounds and the like.

The resin composition formed according to the present invention may also use conventionally used inorganic fillers such as talc, clay and silica.

Furthermore, a polyolefin resin may be used in addition to the above resin component.

As the polyolefin resin used at this time,
An ethylene / unsaturated carboxylic acid ester copolymer formed by a method other than the specific method disclosed in the present invention, such as ethylene / vinyl acetate resin, ethylene /
Propylene copolymer, ethylene / butene-1 copolymer,
A copolymer selected from the group of ethylene / octene-1 and the like, or a polymer modified with an unsaturated carboxylic acid or a derivative thereof, or the like can be used.

Further, as other additives, 2,6-di-t-butylparacresol, phenyl-β-naphthylamine, lauryl stearyl thiodipropionate, tridecyl phosphite, N-salicyloyl-N′-aldehyde hydrazine, N, Antioxidants represented by N'-diphenyl oxide, 2-hydroxybenzophenone, phenyl salicylate, 2-hydroxyphenyl benzotriazole, ethyl-2-cyano-3,3'-diphenyl acrylate, nickel dibutyl dicytocarbamate, Other bis (2,2,6,6) known as hindered amines
There are UV absorbers typified by tetramethylpiperidinyl-4) -sebacate, various stabilizers, pigments, crosslinking agents, crosslinking aids, foaming agents, nucleating agents, and the like.

In order to obtain the flame-retardant resin composition of the present invention, the above-mentioned materials are used in combination with a Banbury mixer, a single-screw or twin-screw kneader,
It can be obtained by kneading with a device known as a usual mixing means such as a kneader.

The flame-retardant resin composition thus obtained is then
The film may be extruded into a tube or sheet, or may be extruded using an inflation or T-die method. In addition, hollow molding, injection molding, rotational molding,
It is possible to carry out molding into a required shape by utilizing compression molding, extrusion coating, press molding or the like.

The flame-retardant resin composition according to the present invention which can be molded in such a manner is required to have flexibility and flame retardancy, and includes electric wires, cables, sealing materials, masterbatches, packing, hoses, sheets and films. There are various uses such as.

[Examples] Hereinafter, the configuration and effects of the present invention will be described in detail with reference to specific examples.

The various measurement conditions in the present invention were performed according to the following criteria.

{Unsaturated carboxylic acid ester (UCE) content} Measured by NMR {Weight average molecular weight} Gel permeation chromatography [Waters Co., 150 C, column: TSK-GMH-6], 1,2,4 as solvent Measured at 135 ° C. with trichlorobenzene.

{Mechanical Strength (TS)} According to JIS K7113, a No. 2 dumbbell was prepared from a 1 mm thick press sheet and tested at a pulling speed of 25 mm / min.

{Oxygen index (OI)} Measured in accordance with JIS K7201.

{Load deflection temperature (HDT)} Measured in accordance with JIS K7207. However, the measured stress is 11.
4 kg / cm ² , heating rate is 2 ° C / min, test piece is 1
The dimensions are 1 × 1 × 0.4 cm. ) {Melting point (MP)} Using DSCII type manufactured by Perkin Elmer Co., Ltd., in nitrogen gas 1
After heating at 80 ° C for 3 minutes and heat treatment, cool down to 50 ° C in 5 minutes, and then measure at a heating rate of 10 ° C / min. Shown by peak apex.

{Kneading method} Using a Labo Plastomill manufactured by Toyo Seiki Seisakusho, a predetermined amount of sample was kneaded at 170 ° C and 50 rpm for 8 minutes. At this time, butyl hydroxytoluene (BHT) and calcium stearate were added at 0.1% by weight and 1% by weight, respectively.

{Magnesium hydroxide} A product manufactured by Wako Pure Chemical Industries, Ltd. was used.

Examples 1 to 5 (1) Production of Ethylene Copolymer Toluene as a solvent, unsaturated carboxylic acid ester, and aluminum chloride as a Lewis acid are added to a reaction vessel in which argon is replaced, and the mixture is added at 20 ° C. for 5 minutes. Stir,
These were reacted.

Then, a chromium catalyst component and an organometallic compound, diethylaluminum, were added thereto, hydrogen was introduced, and then ethylene was continuously introduced to carry out a copolymerization reaction of ethylene and an unsaturated carboxylic acid ester.

The amounts of the solvent and the like used here are as shown in Table 1 below.

The product thus obtained was poured into methanol for precipitation, and the solid collected by filtration was deashed and washed with a hydrochloric acid-methanol mixed solution, and then extracted with acetone for 5 hours.

The yield of the copolymer thus obtained as an extraction residue, the content of unsaturated carboxylic acid ester, MI, melting point and the like were measured, and the results are collectively shown in Table 1 below.

This copolymer was analyzed by infrared absorption spectrum analysis and found to be 1720.
Absorption by the carbonyl group derived from the carboxylic acid ester was observed at the cm ^-1 position, and no long-chain alkyl branch was observed by NMR spectrum analysis.

Since the results of these analyzes and the melting points thereof are much lower than those of polyethylene, this copolymer has a linear ethylene polymer chain, and the carboxylic acid ester is randomly bonded to the ethylene polymer chain. It is thought that this disturbs the crystalline state of the ethylene chain portion, thereby lowering the melting point.

(2) Manufacture of flame-retardant resin composition Magnesium hydroxide was added to 100 parts by weight of the ethylene-based copolymer obtained by the above operation in a quantitative relationship shown in Table 2 below to prepare an antioxidant. Butyl hydroxytoluene 0.1% by weight as a lubricant and calcium stearate 0.1% by weight as a lubricant, and 170 ° C. by a Labo Plastomill,
Kneading was carried out for 8 minutes under the condition of 50 rpm.

The oxygen index, which is an index of mechanical strength and flame retardancy of the obtained mixture, was measured, and the results are shown in Table 2.

(Comparative Example 1) When produced by the high pressure radical method, the content of ethyl acrylate was 4.7 mol% and the weight average molecular weight was 73,
Using an ethylene-ethyl acrylate copolymer having a melting point of 500 and a melting point of 96 ° C., the same evaluation as in Example 1 was performed.

The results are shown in Table 2.

[Effects of the Invention] According to the present invention, even if the amount of the flame retardant is increased, flexibility, heat resistance and mechanical strength are not deteriorated and a high degree of flame retardancy is achieved. When the flame-retardant filler as the main component is blended, it is possible to provide a flame-retardant resin composition that does not generate a toxic gas even if it burns. Therefore, the flame-retardant resin composition according to the present invention can be used in various fields requiring flexibility, heat resistance, and high mechanical strength.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-101643 (JP, A) JP 62-10151 (JP, A) JP 60-130633 (JP, A) JP 58- 194938 (JP, A) JP 58-111844 (JP, A) JP 56-136832 (JP, A)

Claims (1)

[Claims] 1. A formula _{- (- CH 2 -CH 2 -} ) - ...... (1) and formula (However, in the formula, R ¹ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, or 3 to 20 carbon atoms.
Represents an alkenyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. R ² is
Hydrogen atom, alkyl group having 1 to 20 carbon atoms, alkenyl group having 3 to 20 carbon atoms, 3 to 3 carbon atoms
It represents a cycloalkyl group having 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. n is an integer of 0-20. ) And containing 0.001 to 45 mol% of the repeating unit represented by the formula (2), the polymer chain is linear, and the repeating unit represented by the formula (2) is Randomly arranged in the polymer chain and represented by the following formula: −0.87b + 120 <Tm <−0.87b + 135 (3) [In the formula, b is mol% of the repeating unit represented by the above formula (2).
And Tm represents the melting point. ] 100 parts by weight of an ethylene-based copolymer having a melting point of 5,000 or more and a flame-retardant filler 10
A flame-retardant resin composition, characterized in that