JPS645063B2 - - Google Patents

Description

[Detailed description of the invention]

[] Purpose of the invention The present invention provides (A) high-density polyethylene, (B) chlorinated polyethylene, (C) ethylene-vinyl acetate copolymer, (D)
The present invention relates to a flame-retardant composition comprising a halogen-containing compound and/or (E) antimony oxide and (F) an inorganic substance having a Si-O bond, and provides a composition that has excellent weather resistance and is suitable for injection molding. The purpose is to [] Background of the Invention In recent years, demand for flame-retardant compositions has continued to increase, and performance requirements for flame-retardant compositions have become more severe. For example, when wiring high-voltage power distribution lines to construction sites such as civil engineering and construction, it is conventionally Flame retardancy is V-2 according to UL-94 standard
That was enough. However, recently, highly flame-retardant compositions have been desired because of the frequent occurrence of combustion, melting and dripping, and ignition accidents at the above-mentioned close locations. Therefore, in conventional flame retardant compositions, a large amount of flame retardant is added due to insufficient flame retardancy. Therefore, not only are sufficient mechanical strength and processability not obtained, but large amounts of expensive flame retardants are used.
It's getting expensive. [] Structure of the Invention Based on the above, the present inventors have discovered a material that not only has excellent flame retardancy (V-O according to the UL-94 legal standard) and good weather resistance, but also is suitable for injection molding. As a result of various searches to obtain a composition, (A) the density was 0.930 to 0.980 g/cm ³ and the melting point was
112-140℃ and MI 0.01-100g/
(B) high-density polyethylene having at most 8 carbon atoms per 1000 carbon atoms in the main chain and at most 10 side chains; (B) an amorphous to crystalline chlorine content of 20 to 50
chlorinated polyethylene, (C) the content of vinyl acetate is 1 to 25% by weight;
and ethylene with an MI of 5.0 to 30 g/10 min.
Vinyl acetate copolymer (D) Consists of a halogen-containing compound and/or (E) antimony oxide and (F) an inorganic substance having a Si-O bond, and is combined with high-density polyethylene, chlorinated polyethylene, and ethylene-vinyl acetate copolymer. The content of chlorinated polyethylene in the total is 10~
50% by weight, and the content of high density polyethylene is
20 to 60% by weight, but the content of ethylene-vinyl acetate copolymer is at least 10% by weight, and the proportion of halogen-containing organic substances and antimony oxide relative to 100 parts by weight of these is their total amount. A flame retardant composition containing 5 to 50 parts by weight of inorganic material and 5 to 15 parts by weight of an inorganic substance not only has good flame retardancy and cold resistance, but also has good flame retardancy and cold resistance.
The present invention was achieved by discovering that the composition has excellent weather resistance and is suitable for injection molding. [] Effects of the Invention The composition obtained by the present invention further has the following characteristics (effects). (1) Excellent mechanical strength (e.g. tensile strength, tensile elongation). (2) Excellent workability. (3) Heat resistance is also good. (4) Regarding flame retardancy, it is equivalent to V-O according to UL standards, and is highly flame retardant. (5) It is cold resistant and has excellent resistance to stress and cracks. (6) Due to good moldability, molded products with complex shapes can be manufactured. (7) Due to its excellent weather resistance, cracks hardly occur even when exposed outdoors for long periods of time. The composition obtained by the present invention has the above-mentioned effects and can be used in a wide variety of fields. Typical uses are shown below. (1) Clamp covers for high-voltage or low-voltage wires (2) Detention covers for building obstructions (structures, trees, etc.) (3) Detention covers for communications (4) Cable sheath materials (5) Fire-resistant wire sheath materials for firefighting [] DETAILED DESCRIPTION OF THE INVENTION (A) High-density polyethylene The high-density polyethylene used in the present invention is obtained by homopolymerizing ethylene or copolymerizing ethylene and α-olefin. The density of the high density polyethylene is
0.930~0.980g/ ^cm3 , and 0.930~0.975g/cm3
cm ³ is preferred, and 0.930 to 0.972 g/cm ³ is particularly preferred. The density of this high density polyethylene is
If it is less than 0.930 g/cm ³ , the resulting composition will have low tensile strength. Further, the melting point of this high density polyethylene is 112 to 140°C, preferably 115 to 140°C, and particularly preferably 117 to 140°C. If the melting point of the high-density polyethylene is less than 112°C, the resulting composition will have low mechanical strength (particularly tensile strength). On the other hand, if high-density polyethylene with a melting point exceeding 140° C. is used, the processability of the resulting composition is low, and welds and cracks are likely to occur at the hinge portion. Furthermore, the MI of the high density polyethylene is 0.01 to 100 g/10 min, preferably 0.1 to 50 g/10 min, particularly 5 to 50 g/10 min.
g/10 minutes is preferred. If the MI of the high-density polyethylene is less than 0.01 g/10 minutes, the moldability of the resulting composition will be poor. On the other hand, if it exceeds 100 g/10 minutes, the moldability of the composition is good, but a good product cannot be obtained due to lack of appropriate rigidity. This high density polyethylene essentially has at most 8 carbon atoms and at most 10 side chains (short chain branches) per 1000 main chain carbon atoms. The term "essentially" in the high-density polyethylene of the present invention means that the high-density polyethylene consists of the above-mentioned short chain branches, and also includes those having a very small number of carbon atoms in side chains of 11 or more. α used in the production of the high-density polyethylene
-Olefins generally have at most 12 carbon atoms.
(preferably 8 or less) α-olefins, typical examples of which are propylene, butene-
1, hexene-1, 4-methylpentene-1 and octene-1. The copolymerization proportion of α-olefin in this copolymer is usually at most 5% by weight. (B) Chlorinated polyethylene The chlorinated polyethylene used in the present invention can be obtained by chlorinating polyethylene powder or particles in an aqueous suspension or by chlorinating polyethylene dissolved in an organic solvent. (preferably obtained by chlorination in aqueous suspension). In general, amorphous or crystalline chlorinated polyethylenes having a chlorine content of 20 to 50% by weight are preferred, and amorphous and crystalline chlorinated polyethylenes having a chlorine content of 25 to 45% by weight are particularly preferred. The polyethylene is obtained by homopolymerizing ethylene or copolymerizing ethylene with at most 10% by weight of α-olefin (generally having at most 6 carbon atoms). Its density is generally 0.910-0.970/cm ³ . or,
Its molecular weight is 50,000 to 700,000. The polyethylene used to produce the above-mentioned high-density polyethylene and this chlorinated polyethylene is prepared by copolymerizing ethylene alone, ethylene and propylene, or ethylene and the above-mentioned α-olefin using a so-called Ziegler catalyst or a Phillips catalyst. obtained by Ziegler's catalyst is a transition metal compound (for example, a halogen-containing compound of titanium) or a carrier for the transition metal compound (for example, a magnesium-containing compound, a compound obtained by treating the magnesium-containing compound with an electron-donating organic compound). It is obtained from a so-called carrier-supported solid catalyst component obtained by supporting the catalyst component on a solid catalyst and an organoaluminum compound. Additionally, the Phillips catalyst is a carrier-supported catalyst obtained by supporting an oxide of chromium or molybdenum, or a compound of these oxides and zirconium on a carrier (for example, silica, silica-alumina), or a carrier-supported catalyst. It is obtained from organometallic compounds. The above catalysts are merely typical Ziegler catalysts and Phillips catalysts, and other known catalysts may also be used. The method for producing this copolymer is also a well-known method. (C) Ethylene-vinyl acetate copolymer Furthermore, the ethylene-vinyl acetate copolymer used in the present invention has a vinyl acetate content of 1 to 25% by weight, preferably 2 to 25% by weight, particularly 5 to 25% by weight is preferred.
When an ethylene-vinyl acetate copolymer containing less than 1% by weight of vinyl acetate is used, flexibility and mechanical strength (particularly tensile strength) are poor. On the other hand, if more than 25% by weight of the ethylene-vinyl acetate copolymer is used, the flexibility is good, but on the other hand, the balance of physical properties is lost and the moldability of the resulting composition is reduced. In addition, the MI of this ethylene-vinyl acetate copolymer
is 5.0 to 30 g/10 minutes, preferably 7.0 to 30 g/10 minutes, and particularly preferably 7.0 to 25 g/10 minutes. When an ethylene-vinyl acetate copolymer having an MI of less than 5.0 g/10 minutes is used, the moldability of the resulting composition is poor. On the other hand, MI is 30
When using an ethylene-vinyl acetate copolymer with a molecular weight of more than 10 g/10 minutes, the composition has excellent moldability, but not only does it lack adequate rigidity, but its mechanical strength (particularly tensile strength) decreases. . This ethylene-vinyl acetate copolymer is produced by copolymerizing ethylene and vinyl acetate in the presence of a radical generator (e.g., an organic peroxide, an azo compound) by a solution polymerization method or an emulsion polymerization method. This is what we are getting. (D) Halogen-containing organic compound The halogen-containing organic compound used in the present invention is widely known as a flame retardant. Typical examples include tetrachlorophthalic anhydride, chlorinated paraffin, chlorinated bisphenol A, brominated bisphenol S, chlorinated diphenyl, brominated diphenyl, chlorinated naphthalene, tris (β-chloroethyl) phosphate, and tris (dibromo butyl) phosphate. (E) Antimony oxide Further, the antimony oxide used in the present invention is generally used as a flame retardant aid for the halogen-containing organic compound.
Representative examples include antimony trioxide and antimony pentoxide. These halogen-containing organic compounds and antimony oxide are well known from the above-mentioned "Handbook of Chemicals Compounded with Rubber and Plastics." (F) Inorganic substance with Si-O bond The content of SiO ₂ in the inorganic substance with Si-O bond used in the present invention is usually at least 10
% by weight, preferably 30% by weight or more, especially
50% by weight or more is suitable. Further, the content of H ₂ O is usually 1.0 to 20% by weight, preferably 1.0 to 15% by weight, and particularly preferably 1.5 to 15% by weight. Furthermore, the particle size of the inorganic substance is generally
10 mm to 30 microns, especially
10 millimicrons to 25 microns is preferred;
Particularly suitable are inorganic substances having a particle size of 15 millimicrons to 25 microns. Typical examples of inorganic substances with Si-O bonds include wet white carbon, calcium silicate, colloidal silica, some calcium,
Synthetic silicate white carbon containing oxides of aluminum, sodium, iron, etc., ultrafine magnesium silicate, aluminum silicate (clay), talc, nepheline syenite, mica powder, silica powder, diatomaceous earth, Examples include silica sand. Regarding inorganic substances having these Si-O bonds,
Rubber Digest Co., Ltd., “Handbook of Rubber/Plastic Compounded Chemicals” (Rubber Digest Co., Ltd., Showa
The manufacturing method, physical properties, trade name, etc. are described on pages 221 to 253 (published in 1949) and are well known. (G) Blending ratio (mixing ratio) In producing the flame retardant composition of the present invention,
Content rate (mixing ratio) of chlorinated polyethylene in the total of high-density polyethylene, chlorinated polyethylene, and ethylene-vinyl acetate copolymer
is 10 to 50% by weight, preferably 15 to 50% by weight, particularly preferably 15 to 45% by weight. If the proportion of chlorinated polyethylene in the total amount exceeds 50% by weight, a composition with excellent flame retardancy can be obtained, but good molded products cannot be obtained due to poor moldability and processability. On the other hand, if it is less than 10% by weight, a composition with good flame retardancy cannot be obtained. Further, the content (blending ratio) of the ethylene-vinyl acetate copolymer is at least 10% by weight, preferably 15% by weight or more, and particularly preferably 20 to 45% by weight. If the proportion of the ethylene-vinyl acetate copolymer in the total amount is less than 10% by weight, a composition with excellent flexibility cannot be obtained. On the other hand, if it exceeds 45% by weight, a composition with excellent flexibility can be obtained, but a composition with excellent mechanical strength (particularly tensile strength) cannot be obtained. In addition, the blending ratio of high-density polyethylene is
20 to 60% by weight, preferably 20 to 55% by weight, especially 25 to 55% by weight. If the blending ratio of high-density polyethylene in the total of these is less than 20% by weight, the mechanical strength (especially
A composition with excellent tensile strength) cannot be obtained. On the other hand, if it exceeds 60% by weight, cracks are likely to occur in the weld portion of the molded product. In addition, the halogen-containing organic compound and antimony oxide are blended in a total amount of 5 to 50 parts by weight with respect to 100 parts by weight of the high-density polyethylene, ethylene-vinyl acetate copolymer, and chlorinated polyethylene, and 10 to 50 parts by weight. parts by weight, particularly preferably 10 to 45 parts by weight.
The blending ratio of antimony oxide to the amount of halogen element in 100 parts by weight of a halogen-containing organic compound is generally 100 to 600 parts by weight, and 100 to 400 parts by weight.
Parts by weight are preferred, and 150 to 400 parts by weight are particularly preferred from the viewpoint of flame retardancy and bleedability. The important point of the present invention is that in addition to the usual flame retardant formulation consisting of a normal flame retardant (halogen-containing organic compound and antimony oxide), it has good moldability and high flame retardancy (V- O), by blending 5 to 15 parts by weight of an inorganic substance having a Si-O bond to 100 parts by weight of the total amount of high-density polyethylene, chlorinated polyethylene, and ethylene-vinyl acetate copolymer. It is desirable to blend 7 to 15 parts by weight. In producing the composition of the present invention, high-density polyethylene, chlorinated polyethylene, ethylene-vinyl acetate copolymer, halogen-containing organic compound, antimony oxide, and inorganic substance having Si-O bonds are each used alone. or two or more types may be used in combination. (H) Manufacture of compositions, manufacturing of molded articles, etc. Although the composition of the present invention can be obtained by uniformly blending the above-mentioned substances, there are Additives commonly used in the industry such as fillers, mold release agents, oxygen, ozone and light (ultraviolet) stabilizers, binders, lubricants, and colorants may be added depending on the intended use of the composition. Good too. In addition, sulfur vulcanizing agents, sulfur-releasing compound-based vulcanizing agents, amine-based bulking agents, organic peroxide-based crosslinking agents, and organic peroxide-based crosslinking co-agents commonly used in the rubber industry and resin industry. Additives may be added depending on the intended use of the composition. When producing the composition of the present invention, the blending (mixing) method may be to use a mixer commonly used in the art, such as an open roll, dry blender, Banbury mixer, and kneader. Among these mixing methods, in order to obtain a more uniform composition, two or more of these mixing methods may be applied (for example, after mixing in advance with a dry blender, the mixture may be mixed using an open roll). how to). Also, all ingredients may be mixed at the same time, but
After premixing some of the ingredients, the remaining ingredients may be mixed into the resulting mixture (e.g., high density polyethylene, chlorinated polyethylene, ethylene-vinyl acetate copolymer, halogen-containing organic compound). and antimony oxide are mixed in advance, and then the resulting mixture is mixed with an inorganic substance having a Si-O bond). The composition of the present invention may be molded into a desired shape using molding machines commonly used in the rubber industry, such as extrusion molding machines, injection molding machines, compression molding machines, and calender molding machines. In addition, a method is applied in which chlorinated polyethylene or the above-mentioned composition is added to produce a molded product while vulcanization (crosslinking) is generally performed in the rubber technology field, that is, a method in which vulcanization and molding proceed simultaneously. It may be formed into a desired shape. [] Examples and Comparative Examples The present invention will be explained in more detail below using Examples. In addition, in the examples and comparative examples, the tensile test was measured according to JIS C-3005. Further, the heat resistance test was carried out in accordance with JIS C-3005 after being left in a gear oven set at a temperature of 90°C for 96 hours. Furthermore, for the heating deformation test, after leaving it in a constant temperature premises set at 90 ± 2 degrees Celsius for 1 hour, it was taken out and
A test was conducted to determine whether deformation occurs due to softening or the like. In addition, in the cold resistance test, a sheet (thickness 2.5 mm) manufactured as described below was placed in a constant temperature premises at -20℃.
After leaving it for a while, it was bent 180 degrees and tested to see if any cracks would form. Furthermore, the heat resistance test was measured according to JIS K-6911, Sections 5 and 24, and the flame resistance was measured according to method A. Moreover, flame resistance was measured according to the Underlight Laboratory (UL) 94 method. The ingredients used in the Examples and Comparative Examples had the shapes, physical properties, and manufacturing methods described below. [High acetate polyethylene] As high density polyethylene, the density is 0.955g/
cm ³ [MI 20 g/10 min, hereinafter referred to as “HDPE(a)”] and polyethylene with a density of 0.961 g/cm ³ [MI 7.8 g/10 min, hereinafter referred to as “HDPE(b)”]. was used. [Ethylene-vinyl acetate copolymer] As an ethylene-vinyl acetate copolymer, the density is
Ethylene-vinyl acetate copolymer with a density of 0.932 g/cm ³ [MI 12 g/10 min, vinyl acetate content 15% by weight, hereinafter referred to as "EVA(1)"] and a density of 0.928.
An ethylene-vinyl acetate copolymer (MI 9 g/10 ^min , vinyl acetate content 10% by weight or less, referred to as "EVA(2)") was used. [Chlorinated polyethylene] As chlorinated polyethylene, the density is 0.940g/
cm ³ of polyethylene (average molecular weight approximately 200,000) was chlorinated using an aqueous suspension method, and the chlorine content was 30.3% by weight.
Chlorinated polyethylene [density 1.10 g/cm ³ , Mooney viscosity (ML ₁₊₄ (120°C)) 82.5, amorphous, hereinafter referred to as "CPE(1)"] and polyethylene with a density 0.930 g/cm ³ Chlorinated polyethylene (average molecular weight approximately 150,000) is chlorinated by an aqueous suspension method and has a chlorine content of 30.1% by weight [density 1.13g/cm ³ , Mooney viscosity (ML ₁₊₄ (120℃)) 107.0 , crystalline, hereinafter referred to as "CPE(2)"
was manufactured. [Halogen-containing organic compound and antimony oxide] As a halogen-containing organic compound, the density is 1.66.
g/ ^cm3 of chlorinated paraffin (molecular weight approximately 1060,
(Chlorine content approximately 70% by weight, hereinafter referred to as "Salt Para")
was used. Also, as antimony oxide, the density is
Antimony trioxide (hereinafter referred to as "Sb ₂ O ₃ ") with a concentration of 5.25 g/cm ³ was used. [Inorganic substance with Si-O bond] As an inorganic substance with Si-O bond, ultrafine powdered magnesium silicate (density 2.75 g/cm ³ , specific surface area 20
m ² /g, particle size 0.32-6 microns, SiO ₂ content,
62.5% by weight, MgO content 30.6% by weight, _H2O content
4.99% by weight, hereinafter referred to as "MgO・_SiO2 "), aluminum silicate (density 2.61g/ ^cm3 , particle size 2-5 microns, _SiO2 content _50.6 % by weight, _Al2O3 content
34.8% by weight, _H2O content 1.5% by weight, hereinafter referred to as " _AlO2・_SiO2 "), silica (density 1.95g/
cm ³ , specific surface area 19000 cm ² /g, average particle size 16 millimicrons, SiO ₂ content 86.5% by weight, H ₂ O content 13.0% by weight, hereinafter referred to as "SiO ₂ ") and calcium silicate (density 2.1g). /cm ² , average particle size 40 millimicrons, specific surface area 40m ² /g, SiO ₂ content 72% by weight,
CaO content of 10% by weight and _H2O content of 1.5% by weight (hereinafter referred to as " _CaO.SiO2 ") was used. Examples 1 to 13, Comparative Examples 1 to 10 The above composition components (high density polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene,
Halogen-containing organic compounds, antimony oxide, Si-
Inorganic substances having O bonds) in the amounts shown in Table 1 (all parts by weight) and 5 parts by weight of tribasic lead sulfate as a stabilizer (Comparative Example 1
A composition (mixture) was prepared by melt-kneading (without adding 1) using a kneader at a temperature range of 100 to 130°C. Each mixture obtained
A sheet was created using a mixing roll set at 50°C. Pellets were made using each of the obtained sheet cuts. Each pellet obtained in this way was heated to 130°C in cylinder 1 using an extruder (diameter 50 mm, L/D 26) and cylinder 2.
Pelletizing was carried out under the conditions of a temperature of 145° C., a temperature of cylinder 3 of 150° C., a temperature of the die of 150° C., and a rotation speed of 30 revolutions/minute to prepare pellets. These pellets were molded using an extruder and an injection molding machine (manufactured by Nippon Steel Co., Ltd., 5 ounces, cooling time 30 seconds) at a nozzle heater temperature of 200°C, a temperature of heater 1 of 200°C, a temperature of heater 2 of 170°C, and a temperature of 170°C for heater 2. 3 temperature 160℃
A sheet was created under the following conditions. The sheets thus obtained were prepared for the following physical property tests, and tensile strength, heat resistance tests, heat deformation tests, and cold resistance tests were conducted. Furthermore, the flame resistance test was carried out using a press machine set at a temperature of 150°C using the above pellets produced in an extruder, and hot-pressed for 5 minutes under a pressure of 100 kg/cm ² (gauge pressure). 2.5mm
A sheet was created and tested. The results obtained are shown in Table 2.

【table】

【table】

【table】

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[Table] In Comparative Example 2, injection molding was attempted to create a sheet, but the sheet could not be manufactured. Comparative Examples 11-13 25 parts by weight of PE(a) used in Example 1 and
35 parts by weight of EVA(1) and 40 parts by weight of alumina.
Example 1 Trihydrate (average particle size 10 μm) and 5 parts by weight of tribasic lead sulfate used in Example 1
A composition was produced by melt-kneading using a kneader in the same manner as in (Comparative Example 11). 18 parts by weight of PE(a) used in Comparative Example 11,
24 parts by weight of EVA (1), 40 parts by weight of alumina trihydrate and 5 parts by weight of tribasic lead sulfate, and Example 1
A composition was produced by melt-kneading 18 parts by weight of CPE (1) used in Comparative Example 11 in the same manner as in Comparative Example 11.
12). Furthermore, MgO・SiO ₂ used in Example 1
A composition was produced by melt-kneading in the same manner as in Example 1, except that the blending amount was changed to 40 parts by weight (Comparative Example
13). Sheets were prepared from each of the compositions thus obtained in the same manner as in Example 1, and pellets were produced from each sheet. Each of the obtained pellets was manufactured into pellets using an extruder in the same manner as in Example 1. Each test piece was manufactured from each pellet using an injection molding machine, and subjected to a tensile test, a heat resistance test, a heat deformation test, and a cold resistance test. The results are shown in Table 3. In addition, when we conducted a flame resistance test, all of them were UL-
It was VO according to the 94 method, and nonflammable according to the JIS A method.

[Table] From the results of the above Examples and Comparative Examples, it is clear that the flame retardant composition obtained by the present invention shows good values in the tensile test, heat resistance test, and cold resistance test. Furthermore, it is clear that it has excellent flame retardancy, so it is clear that it is a promising material for high voltage or low piezoelectric covers, cable sheath materials, etc. as mentioned above.

Claims (1)

[Scope of Claims] 1 (A) has a density of 0.930 to 0.980 g/cm ³ , a melting point of 112 to 140°C, a melt index of 0.01 to 100 g/10 min, and a carbon atom in the main chain. The number of carbons per 1000 is at most 8.
High density polyethylene with 10 side chains. (B) amorphous or crystalline chlorinated polyethylene with a chlorine content of 20 to 50% by weight; (C) a vinyl acetate content of 1 to 25% by weight;
and an ethylene-vinyl acetate copolymer having a melt index of 5.0 to 30 g/10 minutes, (D) a halogen-containing organic compound and/or (E) antimony oxide, and (F) an inorganic substance having a Si-O bond. , the content of chlorinated polyethylene in the total of the high-density polyethylene, chlorinated polyethylene and ethylene-vinyl acetate copolymer is 10 to 10.
50% by weight, and the content of high density polyethylene is
20 to 60% by weight, but the content of ethylene-vinyl acetate copolymer is at least 10% by weight, and the total amount of halogen-containing organic substances and antimony oxide is 5 to 50 parts by weight based on 100 parts by weight of these. A flame retardant composition in which the blending ratio of the inorganic substance is 5 to 15 parts by weight.