Surface, blush-resistant, fire-retardant polyolefin resin composition

Abstract: A flame-retardant olefin polymer composition superior in surface whitening preventing property is obtained by blending 100 parts by weight of a resin component consisting principally of: a) 99-60% by weight of a polyolefin resin and b) 1-40% by weight of an olefin polymer modified with an unsaturated carboxylic acid or a derivative thereof: with c) 5-200 parts by weight of a flame retardant: and d) at least one component selected from the group consisting of: 1 ○ a mineral oil, a wax, or a paraffin. 2 ○ a higher fatty acid or an ester, amide or metallic salt thereof, 3 ○ a silicone 4 ○ a partial fatty acid ester of a polyhydric alcohol or aliphatic alcohol-, fatty acid-, aliphatic amino-, fatty acid amide-, alkylphenol- or alkylnaphthol-ethylene oxide adduct, and 5 ○ a fluoric elastomer.

Description: (Industrial Utilization Field) The present invention relates to the use of certain additives to render a flame-retardant olefin polymer composition as defined hereinafter, resistant to surface whitening caused by mechanical flawing. The olefin polymer consists principally of 99-60% by weight of an ethylene (meth) acrylic acid alkyl ester copolymer, an ethylene-vinyl acetate copolymer or an ethylene-α-olefin copolymer having a density of 0.86 to 0.91 g/cm 3 ; and 1-40% by weight of an ethylene (co)polymer having a density of 0.86 to 0,97 g/cm 3 graft-modified with 0.05 to 10 wt% of an unsaturated carboxylic acid or derivative thereof. (Prior Arts) Polyethylenes are general-purpose resins. In view of their superior physical and chemical properties they are in great demand. They are suitable for formation into films, sheets, pipes, containers, etc, by various methods, including extrusion, injection molding and rotational molding. They are applied to a variety of domestic and industrial uses. Since such polyethylenes are easy to burn, various methods have heretofore been proposed for rendering them flame-retardant. Among them, the most general method is to add a flame retardant containing a halogen or phosphorus to the polyethylenes. However, although the addition of a small amount of such flame retardant is effective, there is the drawback that a noxious gas is evolved during combustion. Recently, inorganic flame retardants such as aluminium hydroxide and magnesium hydroxide have been proposed as low-smoking and pollution-free flame retardants which do not evolve a noxious gas during combustion. (Related techniques are disclosed, for example, in Japanese Patent Laid Open Nos. 132254/1976 and 136832/1981). In the conventional commercial polyethylenes, the acceptability of particularly inorganic flame retardants is poor. Further, their flame retarding effect is low. In addition, as the amount of loading is increased, the mechanical strength, flexibility and processability of the polyethylenes deteriorate to an impractical extent. Further, when the conventional polyethylenes containing such inorganic flame retardants are used as electric wires or cable, their surfaces become flawed, causing whitening, during laying or use thereof. (Problems to be Solved by the Invention) According to the present invention, in view of the above-mentioned points, the conventional flame-retardant polyolefin resin compositions are provided with a combination of enhanced mechanical strength, heat resistance, processibility, flame retardance, resistance to whitening and also with an improved acid resistance. The compositions can be applied to a variety of uses, including electric wires, cables, packings, sealing materials, hoses, films, molded products, e.g. injection-molded products, and master batches. (Means for Solving the Problems) The present invention resides in: The use of at least one component (d) selected from: (1) a mineral oil, a wax or a paraffin (2) a higher fatty acid or an ester, amide or metallic salt thereof (3) a silicone (4) an adduct of C 2 - C 4 alkylene oxide and a compound selected from a partial fatty acid ester of a polyhydric alcohol, an aliphatic alcohol, a fatty acid, an aliphatic amine, a fatty acid amide, an alkylphenol and an alkylnaphthol, and (5) a copolymer of vinylidene fluoride with one or more monomers selected from chlorotrifluoroethylene, hexafluoropropylene and tetra fluoroethylene to improve resistance to surface whitening resulting from mechanical flawing of a flame retardant olefin polymer composition comprising: 100 parts by weight of: (a) 99 - 60% by weight of an ethylene (meth) acrylic acid alkyl ester copolymer, an ethylene - vinyl acetate copolymer or an ethylene-α-olefin copolymer having a density of 0.86 to 0.91 g/cm 3 ; and (b) 1 - 40% by weight of an ethylene (co) polymer having a density of 0.86 to 0.97 g/cm 3 graft - modified with 0.05 to 10wt% of an unsaturated carboxylic acid or derivative thereof ; and (c) 5-200 parts by weight of a flame retardant, with the proviso that when the at least one component (d) is (5) it is present in an amount of 0.02 to 3 parts by weight and otherwise it is present in an amount of 0.5 to 20 parts by weight. The mechanical flawing is preferably caused by scratching. As concrete examples of the above copolymers (a) there are mentioned ethylene-ethyl acrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-acrylic acid-ethyl acrylate copolymer, ethylene-vinyl acetate-ethyl acrylate copolymer and ethylene-glycidyl methacrylate-ethyl acrylate copolymer. These copolymers may be used as mixtures. The above copolymers are preferably in the range of 0.1 to 50 g/10 min., preferably 0.3 to 20 g/10 min., in terms of melt flow rate (hereinafter referred to simply as "MFR"). A value of MFR smaller than 0.1 g/10-min. will result in poor processability, and if the value thereof exceeds 50 g/10 min., a deteriorated mechanical strength will result. Thus, these values are not preferred. As the olefin polymer modified with an unsaturated carboxylic acid or a derivative thereof, which is used as component b) in the present Invention, there is used an ethylene (co) polymer having a density of 0.86 to 0.97 g/cm 3 graft-modified with 0.05 to 10 wt% of an unsaturated carboxylic acid or a derivative thereof. The graft modification preferably occurs in the presence of an organic peroxide. As examples of the olefin polymer there are mentioned polyethylene, copolymers of ethylene,with propylene, 1-butene, 4-methyl-1-pentene, 1-hexene or 1-octene; copolymers of ethylene with vinyl esters, unsaturated carboxylic acids, or unsaturated carboxylic esters; and mixtures thereof. Particularly preferred are polyethylenes and ethylene-α-olefin copolymers, e.g. an ethylene-butene-1 copolymer. As examples of the unsaturated carboxylic acid or derivatives thereof used in the modification of the olefin polymer there are mentioned mono- and dibasic acids such as acrylic, methacrylic, maleic and fumaric acid, as well as metallic salts, amides, imides, esters and anhydrides of the unsaturated carboxylic acids just exemplified. Maleic anhydride is the most preferred. According to a preferred method for modifying the olefin polymer with the unsaturated carboxylic acid or derivative thereof, both are heat-reacted in the presence of an organic peroxide. How to perform the above reaction is not specially limited. For example, the reaction may be conducted by melt-mixing the components in the absence of a solvent within an extruder or a kneader such as a Banbury mixer, or it may be conducted by heat-mixing the components in a solvent such as an aromatic hydrocarbon, e.g. benzene, xylene or toluene, or an aliphatic hydrocarbon such as hexane, heptane or octane. Preferably, the reaction is carried out within an extruder as this method is both economic and simple to operate. The unsaturated carboxylic acid or derivative thereof is used in an amount in the range of 0.05 to 10 wt%, preferably 0.1 to 5.0 wt%. If the amount thereof is smaller than 0.05 wt%, the present invention will be less effective and a coupling effect of the resin and the flame retardant will not be exhibited. On the other hand, if the amount exceeds 10 wt%, it is possible that decomposition and crosslinking reaction will take place at the time of modification. Suitable examples of the organic peroxide referred to above include benzoyl peroxide, lauryl peroxide, dicumyl peroxide, t-butyl hydroperoxide, α,α-bis(t-butylperoxydiisopropyl)benzene di-t-butyl peroxide, 2,5-di(t-butylperoxy)hexyne, and azobisisobutyronitrile. The organic peroxide is preferably used in an amount in the range of 0.005 to 2.0, preferably 0.01 to 1.0, part by weight per 100 parts by weight of the olefin polymer. If the amount of the organic peroxide used is less than 0.005 part by weight, there will be no substantial effect of modification. If the organic peroxide is used in an amount exceeding 2 parts by weight, the effect is unlikely to be increased and there is a likelihood of an excessive decomposition or cross-linking reaction. A suitable reaction temperature is determined in consideration of usual temperature conditions such as the deteriorating temperature of the resin and the decomposition temperatures of the unsaturated carboxylic acid and the organic peroxide. Generally, the reaction is carried out at a temperature in the range of 150° to 300°C. In the present invention, the amount of component b) is in the range of 1 to 40 wt%, preferably 10 to 25 wt%, relative to component a). If the amount of component b) is less than 1 wt%, there will be little improvement in tensile strength, and if it exceeds 40 wt%, there will be a marked deterioration of elongation. In the present invention, together with the olefin polymers exemplified above there may be used unmodified olefin polymers and synthetic rubbers, for example, such solid rubbers as polyisobutylene, butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber polybutadiene rubber, chloroprene rubber, urethane rubber and ethylene-vinyl acetate copolymer rubber, or such liquid rubber as liquid polybutadiene rubber, as well as natural rubbers, and mixtures thereof. As the flame retardant used as component c) in the present invention there may be used any of those which are generally considered to be effective. Examples are organic and inorganic flame retardants, such as halogen- and phosphorus-based flame retardants. The following are illustrative of organic flame retardants. As examples of halogen-based flame retardants there are mentioned bromine-based flame retardants such as tetrabromobisphenol (TDA), hexabromobenzene decabromodiphenyl ether, tetrabromoethane (TBE), tetrabromobutane (TBB), and hexabromocyclodecane (HBCD) ; chlorine-based flame retardants such as chlorinated paraffin, chlorinated polyphenyl, chlorinated polyethylene, chlorinated diphenyl, perchloropentacyclodecane, and chlorinated naphthalene; general halogen-based flame retardants such as halogenated diphenyl sulfides; halogenated polystyrenes and derivatives thereof, such as brominated polystyrene and brominated poly-α-methylstyrene; halogenated polycarbonates such as brominated polycarbonate; halogenated polyesters such as polyalkylenetetrabromoterephthalates and brominated terephthalic acid-based polyesters; halogenated epoxy compounds such as halogenated bisphenol type epoxy resins; halogenated polyphenylene oxide compounds such as poly(dibromophenylene oxide); and high molecular type halogen-containing polymers such as cyanuric esters of halogenated bisphenols. As examples of phosphorus-based flame retardants there are mentioned phosphoric esters and halogenated phosphoric esters, such as tricresyl phosphate, tri(β-chloroethyl)phosphate, tri(dibromopropyl)phosphate and 2,3-chloropropyl phosphate, phosphonic acid compounds and phosphinic acid derivatives. Guanidine compounds such as guanidine nitride are also mentioned as examples of employable flame retardants. The organic flame retardants exemplified above may be used alone or in a combination of two or more. The organic flame retardants may be used in an amount in the range of 5 to 50, preferably 7 to 40, parts by weight for 100 parts by weight of the resin components a) and b). If the amount of organic flame retardant(s) used is less than 5 parts by weight, there will not be obtained a satisfactory flame retarding effect, and even in an amount thereof exceeding 50 parts by weight, the flame retarding effect will not be improved, whilst an increase in costs will result. Thus, both such amounts are undesirable. The organic flame retardants exemplified above, especially halogen-based flame retardants, may be used together with flame retarding aids, whereby a synergistic effect can be developed. Typical examples of flame retarding aids include antimony compounds such as antimony trioxide, antimony pentoxide, antimony halides, e.g. antimony trichloride and antimony pentachloride, antimony trisulfide, antimony pentasulfide, antimonic acid soda, antimony tartrate, and metallic antimony. As examples of inorganic flame retardants there are mentioned hydrates of inorganic metallic compounds such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, basic magnesium carbonate, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, hydrate of tin oxide, and borax, as well as zinc borate, zinc metaborate, barium metaborate, zinc carbonate, calcium magnesium carbonate, calcium carbonate, barium carbonate, magnesium oxide, molybdenum oxide, zirconium oxide, tin oxide, and red phosphorus. The inorganic flame retardants exemplified above may be used alone or in a combination of two or more. Above all, at least one metallic compound hydrate selected from the group consisting of aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, basic magnesium carbonate, dolomite and hydrotalcite is preferably employed. Aluminum hydroxide and magnesium hydroxide are particularly preferred because of their superior flame retarding effect and economical advantage. The particle sizes of the inorganic flame retardants differ depending on the kind thereof, but in the case of aluminum hydroxide and magnesium hydroxide, the average particle diameter generally is 20 µm or smaller, preferably 10 µm or smaller. The inorganic flame retardants exemplified above may be used in an amount in the range of 30 to 200, preferably 40 to 150, more preferably 50 to 120, parts by weight for 100 parts by weight of the resin components a) and b). If the amount of inorganic flame retardant (s) used is less than 30 parts by weight, it is necessary to use organic flame retardant(s) together with the inorganic flame retardant(s) because with the use of the latter alone it is difficult to attain a satisfactory flame retarding effect. On the other hand, an amount thereof exceeding 200 parts by weight will result in deteriorated mechanical strength such as deteriorated impact resistance, loss of flexibility and poor low-temperature characteristics. Component (d) which is used as a whitening preventing agent in the present invention is at least one member selected from 1 ○ a mineral oil, a wax or a paraffin, 2 ○ a higher fatty acid or an ester, amide or metallic salt thereof, 3 ○ a silicone, 4 ○ an adduct of C 2 -C 4 alkylene oxide and a compound selected from a partial fatty acid ester of a polyhydric alcohol, an aliphatic alcohol, a fatty acid, an aliphatic amine, a fatty acid amide, an alkylphenol and an alkylnaphthol, and 5 ○ a copolymer of vinylidene fluoride with one or more monomers selected from chlorotrifluoroethylene, hexafluoropropylene and tetrafluorethylene. As examples of the above 1 ○ (a mineral oil, a wax or a paraffin) there are mentioned mineral oils such as process oil, waxes such as microwax and polyethylene wax, and paraffins such as liquid paraffin and natural paraffin. As examples of the above 2 ○ (a higher fatty acid or an ester, amide or metallic salt thereof) there are mentioned higher fatty acids such as erucic acid, oleic acid, stearic acid, palmitic acid, linoleic acid, linolenic acid, sorbitan fatty acid, diglycerol fatty acid, pentaerythritol fatty acid, dipentaerythritol fatty acid, and polyoxyethylene fatty acid; higher fatty acid esters such as butyl stearate, stearic acid monoglyceride, oleic acid monoglyceride, 12-hydroxystearic acid, polyoxyethylene(5)glycerol monostearate, polyoxyethylene(2)glycerol monostearate, and polyoxyethylene(5)monooleate; erucic acid amid, oleic acid amide, stearic acid amide, ethylenehydroxystearamide, methylenebisstearamide, ethylenebisstearamide, and other composite amides. As examples of metallic salts of higher fatty acids there are mentioned magnesium stearate, zinc stearate, calcium stearate, barium stearate and zinc laurylate. As examples of the above 3 ○ (a silicone) there are mentioned silicone oils, silicone oligomers silicone rubbers, and silicone resins. Particularly, silicone oils modified with higher fatty acids are most preferred. As examples of the above 4 ○ (an adduct of C 2 -C 4 alkylene oxide and a compound selected from a partial fatty acid ester of a polyhydric alcohol, an aliphatic alcohol, a fatty acid, an aliphatic amine, a fatty acid amide, an alkylphenol and an alkylnaphthol) there are mentioned condensates of, for example, ethylene oxide and propylene oxide with the above fatty acids, sorbitan fatty acid esters such as sorbitan monostearate and sorbitan monopalmitate, glycerol fatty acid esters, diglycerol fatty acid esters, pentaerythritol fatty acid esters, and fatty acid amides. Suitable addition rates are in the range of 1 to 30 moles in the case of ethylene oxide and 1 to 10 moles in the case of propylene oxide. These may be added each alone or as a mixture, and may be random or block. The above 1 ○ to 4 ○ are particularly effective in preventing surface whitening resulting from mechanical flawing. Above all, higher fatty acid amides such as oleic acid amide and stearic acid amide as well as silicones such as silicone oils modified with higher fatty acids are preferred. Especially, higher fatty acid amides are inexpensive so advantageous from an economic point of view. If the whitening preventing agent is at least one of 1 ○ to 4 ○ it is used in an amount in the range of 0.05 to 20, preferably 0.5 to 5, parts by weight for 100 parts by weight of the resin components. If the amount of these whitening preventing agents is smaller than 0.05 parts by weight, the resistance to surface whitening resulting from mechanical flawing will be unsatisfactory, and if it exceeds 20 parts by weight, not only will there arise the possibility of deterioration in mechanical characteristics such as tensile strength but also the resistance to surface whitening resulting from mechanical flawing will not be improved. Further, a large amount is undesirable from an economic viewpoint. Where at least one component 5 ○ is used it is added in a relatively small amount such that the evolution of a noxious gas occurs only to a negligible extent. 5 ○ is effective in imparting water resistance to the composition, improving the resistance to surface whitening resulting from mechanical flawing, improving the acid resistance of the composition and improving moldability. Further, the problems associated with the formation of eye mucus in operators involved in processing prior art compositions are overcome. The amount of the fluoric elastomer is in the range of 0.02 to 3, more preferably 0.05 to 2, parts by weight relative to the amount of the other components described above. The addition of the component d) not only improves the resistance to surface whitening resulting from mechanical flawing but also is effective in improving the acid resistance of the composition. In the flame-retardant olefine polymer composition containing component (d), as described above, the problems associated with the deterioration of tensile strength which has been a drawback of a conventional flame-retardant compositions containing a large amount of an inorganic flame retardant are overcome and the heat resistance is improved. In addition, the dripping of the composition during combustion is prevented. Thus, a high degree of flame retardance is attained according to the present invention. In particular, when an ethylene (meth)acrylic acid alkyl ester copolymer, such as an ethylene-ethyl acrylate copolymer, or an ethylene-vinyl acetate copolymer is used as component a), the resulting composition is good in its acceptability for inorganic compounds, and it is presumed that a coupling effect of the component a) and e.g. the hydrate of an inorganic compound used as component c) is developed by the addition of an appropriate amount of the modified olefin polymer as component b), thereby permitting the improvement of tensile strength while keeping the deterioration of elongation to a minimum, and that the component d) bleeds out to the surface of the composition to an appropriate extent to form a thin film, thereby improving the resistance to surface whitening resulting from mechanical flawing and improving the acid resistance. The compositions described above may be used in combination with inorganic fillers, whereby not only the proportion of the flame retardant used can be reduced but also other characteristics can be imparted to the composition. Examples of such inorganic fillers include calcium sulfate, calcium silicate, clay, diatomaceous earth, talc, alumina, siliceous sand, glass powder, iron oxide, metal powder, graphite, silicon carbide, silicon nitride, silica, boron nitride, aluminum nitride, carbon black, mica, glass plate, sericite, pyrophyllite, aluminum flake, graphite, Shirasu balloon, metal balloon, glase balloon, pumice, glass fiber, carbon fiber, whisker, metallic fiber, graphite fiber, silicon-carbide fiber, asbestos, and wollastonite. The amount of these inorganic fillers which may be used in the present invention is up to 100 parts by weight for 100 parts by weight of the composition. An amount thereof exceeding 100 parts by weight is not desirable because it will cause deterioration in mechanical characteristics such as impact strength of molded products obtained from the composition. In the case where the foregoing inorganic flame retardants or the inorganic fillers just exemplified above are used, it is desirable to treat their surfaces, for example, coat them with a fatty acid such as stearic, oleic or palmitic acid, or a metallic salt thereof, paraffin, wax, polyethylene wax, or a modified compound thereof, an organosilane, organoborane or organotitanate. The resin components a) and b), flame retardant c), the agent d) used to improve the resistance to surface whitening resulting from mechanical flawing, as well as, if desired, inorganic fillers and additives, are melt-kneaded in a conventional kneading machine such as a Banbury mixer, a pressure kneader, a kneader/extruder, a double-screw extruder, or roll, and thereby pelletized for the supply as moldings or master batch. Alternatively, the resin components may be dry-blended with the flame retardant and other additives. In the compositions there may be incorporated other thermoplastic resins, synthetic and natural rubbers, organic fillers, antioxidants, lubricants, organic and inorganic pigment, as well as other additives such as ultraviolet inhibitors, dispersants, copper deactivators, neutralizers, foaming agents, inhibitors, plasticizers, antifoaming agents, weld strength improvers and nucleating agents. The selection of additives will depend on the intended use of the composition and is made such that the additives do not impair the effect of the present invention. Also, a crosslinking agent (e.g. an organic peroxide, sulfur, a silane crosslinking agent) and a crosslinking aid may be added to the composition for the introduction of a crosslinked structure therein, or ionizable radioactive rays may be radiated to the composition. (Examples) The following examples are given, but the present invention is not limited thereto. [Resins and Materials used] Component a) a-1: Ethylene-ethyl acrylate copolymer (EEA, hereinafter) (EA content = 15 wt%, MFR = 0.75g/10 min, trade name: Nisseki Rexlon A1150, a product of Nippon Petrochemicals Co., Ltd.) a-2: Ethylene-vinyl acetate copolymer (EVA, hereinafter) (MFR = 1.0 g/10 min, trade name: Nisseki Rexlon V260, a product of Nippon Petrochemicals Co., Ltd.) a-3: Ethylene-α-olefin copolymer (PE, hereinafter) (MRF = 1.0 g/10 min. density = 0.900, trade name: Nisseki Softrex D9010) Component b) Maleic acid-modified ethylene-butene-copolymer (MLLDPE, hereinafter) (trade name: Nisseki N Polymer L6100, a product of Nippon Petrochemicals Co., Ltd.) Component c) C-1: Magnesium hydroxide (trade name: Kisuma 5B, a product of Kyowa Kagaku K.K.) c-2: Aluminum hydroxide (trade name: Higilite 42M, a product of Nippon Light Metal Company, Ltd.) Component d) d-1 : Oleic acid amid (OA, hereinafter) (a product of Nippon Seika K.K. d-2: Erucic acid amid (EA, hereinafter) (a product of Nippon Selka K.K.) d-3: Carnauba wax (WAX, hereinafter) (a product of Noda Wax K.K.) d-4: Higher fatty acid-modified silicone oil (MSI, hereinafter) (trade name: TSF410, a product of Toshiba Silicone K.K.) d-5: Dimethylsilicone oil (Si, hereinafter) (trade name: TSF451, a product of Toshiba Silicone K.K.) d-6: Master batch of a propylene hexafluoride-vinylidene fluorlde copolymer dispersed in a linear, low-density polyethylene at a concentration of 1.7%, (F hereinafter) (trade name: PA-1700, a product of Polycol Kogyo K.K.) (Testing Method) (1) Tensile Strength (UTS) and Elongation (%) A No.3 dumbbell specimen from 1 mm thick sheet was measured for tensile strength and elongation at a pulling rate of 200 mm/min using a Tensilon. (2) Oxygen Index (O.I) Measured according to JIS K7201. (3) Test To Measure Resistance To Surface Whitening Resulting From Mechanical Flawing A 30 x 150 mm specimen was prepared from 1 mm thick sheet. A sapphire stylus of R=0.5 mm was placed on the sheet surface and perpendicular thereto. The sheet was then slid at a rate of 2,000 mm/min. The load (g) imposed when the sheet was flawed and became white was taken as the flawed point. (4) Surface Whitening Test (measuring chemically induced surface whitening - acid resistance) A tubular specimen was suspended in a hermetically sealed 10-liter autoclave charged with 400 c.c. of water and containing a gaseous mixture of 99% nitrogen and 1% carbon dioxide. The surface whitening condition of the specimen was observed visually and evaluated after ten days. 1 ... not whitened at all 2 ... shows a sign 3 ... whitened slightly 4 ... whitened 5 ... whitened throughout the whole surface Examples 1 - 20 and Comparative Examples 1 - 4 The components a), b), c), and d) were dry-blended in the proportions described in Table 1, and melt-kneaded by means of a double-screw extruder to obtain pellets. Then, using the pellets, test were conducted. The results of the tests are as shown in Table 1. In the above flame-retardant olefin polymer compositions containing components a), b) and, as component c), aluminum hydroxide and/or magnesium hydroxide, by blending them with component d), i.e. a fatty acid amide, a silicone oil, or a fluoric elastomer, the acceptability for the inorganic flame retardant is improved and the flame retarding effect is enhanced by a coupling effect of the resin components and the inorganic flame retardant, whereby it is made possible to prevent the deterioration of mechanical strength such as tensile strength which has been a drawback of conventional inorganic flame-retardant resin compositions and also possible to improve the heat resistance. Besides, by the use of component d), the whitening preventing performance and the acid resistance can be improved to a remarkable extent, thus meeting the recent needs. Further, since the compositions are superior in electrical characteristics, they can be used as an electrical material such as an electrical insulator or sheath for electric wire or cable, in a crosslinked or uncrosslinked state. Particularly, the compositions are suitable for use in places where a high degree of flame retardance is required. For example, they are suitable for cables in various power generation plants, including atomic energy laboratories wherein the amount of corrosive gas is specified, also for cables in chemical, iron and steel and petroleum plants, as well as fire-proof electric wire and general house wiring. Additionally, the compositions can be applied to molding use for obtaining extruded or injection molded products such as films, sheets and pipes, or can be used as a master batch. They may be utilized as panels, packing materials, electric and electronic parts, automobile parts, furniture and household utensils in the fields of fibers, electric and electronic industries, automobilies, ships, aircraft, construction and civil engineering works.

Claims: The use of at least one component (d) selected from: (1) a mineral oil, a wax or a paraffin (2) a higher fatty acid or an ester, amide or metallic salt thereof (3) a silicone (4) an adduct of C 2 - C 4 alkylene oxide and a compound selected from a partial fatty acid ester of a polyhydric alcohol, an aliphatic alcohol, a fatty acid, an aliphatic amine, a fatty acid amide, an alkylphenol and an alkylnaphthol, and (5) a copolymer of vinylidene fluoride with one or more monomers selected from chlorotrifluoroethylene, hexafluoropropylene and tetra fluoroethylene to improve resistance to surface whitening resulting from mechanical flawing of a flame retardant olefin polymer composition comprising: 100 parts by weight of: (a) 99 - 60% by weight of an ethylene (meth) acrylic acid alkyl ester copolymer, an ethylene - vinyl acetate copolymer or an ethylene-α-olefin copolymer having a density of 0.86 to 0.91 g/cm 3 ; and (b) 1 - 40% by weight of an ethylene (co) polymer having a density of 0.86 to 0.97 g/cm 3 graft - modified with 0.05 to 10wt% of an unsaturated carboxylic acid or derivative thereof; and (c) 5-200 parts by weight of a flame retardant, with the proviso that when the at least one component (d) is (5) it is present in an amount of 0.02 to 3 parts by weight and otherwise it is present in an amount of 0.5 to 20 parts by weight. The use according to Claim 1 wherein resistance to surface whitening resulting from scratching is improved. The use according to Claim 1 or 2 wherein the unsaturated carboxylic acid or derivative thereof is maleic anhydride. The use according to any one of Claims 1 to 3 wherein the flame retardant is a hydrate of an inorganic metallic compound. The use according to Claim 4 wherein the hydrate of an inorganic metallic compound comprises aluminium hydroxide or magnesium hydroxide. The use according to any one of Claims 1 to 5 wherein the at least one component is a copolymer of vinylidene fluoride with one or more monomers selected from chlorotrifluoroethylene, hexafluoropropylene and tetrafluoroethylene.

Inventors: HARASHIGE MASAHIRO, INOUE TAKASHI, KANEKO SATORU, KAWAMURA TSUTOMU, TOKUTAKE ATSUO, YOCHIKAWA TOSHITSUNE, HARASHIGE, MASAHIRO, INOUE, TAKASHI, KANEKO, SATORU, KAWAMURA, TSUTOMU, TOKUTAKE, ATSUO, YOCHIKAWA, TOSHITSUNE
Applicants: NIPPON PETROCHEMICALS CO LTD, NIPPON PETROCHEMICALS CO., LTD.
Application year: 1989
Main classification: C08L23
IPC codes: C08L51, C08L23