JPH02251552A - Flame-retardant resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of intumescence, carbonization and formation of heat-insulating layer in combustion and suitable as a protective layer for flammable materials by blending a halogen-containing or halogen-incorporated polymer with a flame-retardant consisting of zinc borate whose surface is covered with antimony, etc. CONSTITUTION:With 100 pts.wt. halogen-containing polymer (e.g. polyvinyl chloride) or halogen-incorporated polymer, 1 to 50 pts.wt. flame-retardant consisting of zinc borate whose surface is covered with an antimony or molybdenum oxide (e.g. antimony trioxide or molybdenum trioxide) is blended. The above-mentioned metallic oxide is surface treated with a fatty acid, a metallic salt of a fatty acid, a silane compound or a titanate compound as necessary.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a flame-retardant material that is extremely effective in forming a protective layer for combustible materials because it foams and carbonizes during combustion to form a strong heat insulating layer. This invention relates to a resin composition.

[Prior Art] In recent years, there has been an increasing demand for flame retardant rubber and plastic materials. Halogen-containing polymers such as polyvinyl chloride and chloroprene rubber, which have halogen elements in their molecules, are flame retardant in themselves, and are materials that are well-balanced in terms of processability, economy, and many other aspects. It has been widely used since. In addition, polymers that do not have halogen in the molecule, such as polyethylene, polypropylene, ethylene-propylene rubber, styrene-butadiene rubber, etc.
Halogen-added polymers containing organic halogen compounds containing chlorine, bromine, etc. are also often used.

However, in the current situation where application fields are expanding and flame retardant requirements are becoming more and more severe, we are not relying solely on the flame retardant effect of halogen elements, but are actively using flame retardants and flame retardant aids. Measures are being taken to utilize this material to impart a high degree of flame retardancy. Typical examples thereof are metal oxides such as antimony oxide and zinc compounds, and so-called metal hydroxides having water of crystallization in their molecules have also been put into practical use.

Adding flame retardants or flame retardant aids to polymers to improve their flame retardancy may conversely lead to a decrease in the inherent properties of the polymer, such as electrical properties, mechanical properties, and moldability. These are in a mutually contradictory relationship.

For this reason, for example, when contradictory properties such as flame retardance and electrical properties are required, as in the field of electric wires and cables, the inner layer is made of a combustible material with excellent electrical properties, and the inner layer is made of a combustible material with excellent electrical properties. Measures are taken such as providing the outer layer with a material with excellent flammability.

When using a combination of different materials in this way, the outer layer material must have flame retardancy as well as the ability to prevent heat and flame from propagating to the inner layer, and when burned, it foams and expands to form a strong carbonized layer. This is an essential condition.

Zinc borate catalytically promotes the dehalogenation reaction of halogen-containing polymers and halogen-added polymers, which not only improves flame retardancy but also promotes the generation of hydrogen halide gas and carbonization, resulting in strong foaming carbonization. It contributes to the formation of layers, and has high expectations as a flame retardant.

[Problems to be Solved by the Invention] However, from the opposite perspective, this effect of zinc borate impairs the thermal stability of resin compositions and products. Therefore, there is a problem that dehalogenation reaction, that is, decomposition reaction of the polymer easily occurs due to the heat during kneading and molding, making it impossible to carry out stable production activities. Further, dehalogenation reactions easily occur due to the heat generated during the actual use of the product, resulting in problems such as discoloration and deterioration of properties due to deterioration.

On the other hand, powders of inorganic compounds such as zinc borate are prone to secondary agglomeration (when added to polymers, they cause poor dispersion, impairing product properties and appearance, and the presence of coarse particles reduces electrical properties. cause.

The present invention has been made based on the above, and is capable of improving the thermal stability of resin compositions containing halogen-containing polymers or halogen-added polymers while maintaining the inherent flame retardant effect of zinc borate. The object of the present invention is to provide a flammable resin composition.

[Means for Solving the Problems] The flame-retardant resin composition of the present invention includes a halogen-containing polymer or a halogen-added polymer mixed with a flame retardant in which the surface of zinc borate is coated with antimony or molybdenum metal oxide. It is characterized by the fact that

In the present invention, halogen-containing polymers include those containing halogen elements such as chlorine, bromine, and fluorine in the polymer molecule, such as polyvinyl chloride, chlorinated polyethylene,
Chlorosulfonated polyethylene, chloroprene, graft copolymers of vinyl chloride and ethylene-vinyl acetate, ethylene-ethyl acrylate, chlorinated polyethylene, polyurethane, etc., copolymers of vinyl chloride and ethylene, propylene, vinyl acetate, etc. is a halogen-containing polymer and polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-
It may also be a blend with ethyl acrylate copolymer or the like.

Examples of halogen-added polymers include organic halogen compounds in halogen-free polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and styrene-butadiene copolymer. Examples include those with added . Examples of organic halogen compounds include chlorinated paraffin, chlorinated polyethylene, perchloropentacyclodecane, dimethanocyclooctadecachlorododehydrodibenzene, dodecachlorododecahydrodibenzocyclooctene, tris(chloroethyl)phosphate, tris (2-chloropropyl) phosphate, tris(2,3-dichloropropyl) phosphate, tetrabromoethane, decabromo diphthalic acid, tetrabromo phthalic anhydride, tetrabromo bisphenol A,
Examples include dibromoethyl dibromosif, tris(2,3-bromopropyl) phosphate, tris(bromochloropropyl) phosphate, and these may be added alone or in combination of two or more.

The flame retardant used in the present invention is zinc borate whose surface is coated with antimony or molybdenum metal oxide, which suppresses the promotion of dehalogenation reactions in halogen-containing polymers and halogen-added polymers, and Decomposition due to heat during kneading and molding of the composition, and thermal discoloration and deterioration during product use are suppressed.

Zinc borate is not particularly limited, but it is preferable to use one having an average particle diameter of 10 μm or less, particularly 0.5 to 6 μm, from the viewpoint of product appearance, mechanical properties, etc. In addition, as the particle size decreases, the specific surface area increases (and the contact ratio with halogen increases, thereby improving reaction efficiency and exhibiting excellent flame retardancy and foaming carbonization properties).

Examples of antimony or molybdenum metal oxides that coat the surface of zinc borate include antimony trioxide, antimony pentoxide, and molybdenum trioxide.

Examples of a method for coating the surface of zinc borate with these metal oxides include a method in which both are placed in a super mixer, Henschel mixer, tube mill, etc. and mixed under grinding conditions. When mixed under grinding conditions,
The metal oxide is milled with zinc borate particles, and the milling results in coating the zinc borate with fine particles of metal oxide.

When coating zinc borate with a metal oxide, the weight ratio [%] of both metal oxide/zinc borate is 1-40/9.
It is preferable to use a range of 9 to 60, and the lead compound content is too small. If it is too much, the effect of improving thermal stability tends to be small, and if it is too much, the formation of the foamed carbonized layer tends to be insufficient.

In the present invention, the metal oxide may be surface-treated with a fatty acid, a fatty acid metal salt, a silane compound, or a titanate compound, thereby preventing poor dispersion due to secondary aggregation of the flame retardant. Is possible.

Examples of fatty acids include stearic acid, capric acid, lauric acid, oleic acid, linoleic acid, lylunic acid, etc.
Furthermore, fatty acid amides such as lauric acid amide, stearic acid amide, and oleic acid amide, palmityl alcohol,
Also included are fatty acid alcohols such as stearyl achlor.

Examples of fatty acid metal salts include sodium stearate, potassium stearate, magnesium stearate, aluminum stearate, barium stearate, lead stearate, dibasic lead stearate, barium ricinoleate, calcium ricinoleate, potassium oleate, and laurel. Examples include calcium phosphate.

Examples of silane compounds include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(β-methoxyethoxy)silane, phenyltrimethoxysilane, γ-
Methacryloxypropyltrimethoxysilane, β-(3
, 4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane,
γ-Mercaptopropyltrimethoxysilane, γ-(2
Examples include -aminoethyl)aminoethyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like.

Titanate compounds include isopropyl tri(dioctyl phosphate) titanate, isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, tetraisopropyl bis(dioctyl phosphite) titanate, his(dioctyl pyrophosphate) oxyacetate titanate, bis(dioctyl pyrophosphate) phosphate) ethylene titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl) bis(di-tridecyl) phosphite titanate, and the like.

The flame retardant of the present invention exhibits excellent flame retardant effects when used alone or in combination with other flame retardants in halogen-containing polymers or halogen-added polymers. Other flame retardants used in combination include antimony compounds, aluminum hydroxide, magnesium hydroxide, chlorine compounds, bromine compounds, and the like.

The blending amount of the flame retardant of the present invention in the halogen-containing polymer or halogen-added polymer is preferably in the range of 1 to 50 parts by weight per 100 parts by weight of the polymer, and if it is less than 1 part by weight, the flame retardant effect is insufficient. If the amount exceeds 50 parts by weight, mechanical strength and thermal stability tend to decrease.

In addition to the above ingredients, the present invention uses plasticizers such as phthalate esters and trimellitate esters, stabilizers such as lead-based, tin-based, barium-zinc-based, phosphite-based, and epoxy-based stabilizers, fatty acid-based, methacrylic-based, and acrylic. A lubricant, an antioxidant, an antistatic agent, an anti-termite agent, an anti-mold agent, an anti-corrosion agent, a processing aid, an ultraviolet absorber, a coloring agent, etc. may be added. Further, a crosslinking agent or a crosslinking aid may be added to impart crosslinkability.

[Examples of the Invention] Flame retardants No. 1 to No. 5 were prepared by coating zinc borate having an average particle size of 2.0 μm with the materials shown in Table 1.

(The following is a blank space) Table 1 A resin composition having the following components was prepared using the flame retardants shown in Nos., 1-No., and 5 in Table 1.

0 Polyvinyl chloride (average degree of polymerization 1500) 100 parts by weight 0 Dioctyl phthalate 50 parts by weight 0 Tripartite lead phthalate 7 parts by weight 0 Lead stearate 1 part by weight 0 Flame retardant No.
1-No. 5 40 parts by weight Table 2 shows the results of evaluating various properties of this resin composition. In addition, the evaluation was performed based on the following.

Thermal stability: Press molded into a 2mm sheet and length 100
mm.

A test piece with a width of 20 mm was prepared, and this was coated with fluororesin (
PTFE) on a board, B specified in JIS K7212.
It was placed in a gear oven based on a mold and heated at 200° C. for 30 and 60 minutes, and then the occurrence of carbonization and decomposition was observed and evaluated.

Initial tensile properties: Measured according to JIS K6723.

Heat aging resistance = Tensile properties after heating at 100°C for 120 hours were measured, and the residual rate was determined by comparing with the initial value.

Tensile properties were measured after being immersed in oil at 0° C. for 4 hours, and the residual ratio was determined by comparing with the initial value.

Brittleness temperature: Measured based on JIS K6723.

Oxygen index: Measured based on JIS K7201.

(Space below) Table 2 [Effects of the Invention] As explained above, according to the present invention, while maintaining the flame retardancy and foaming carbonization properties inherent to zinc borate, halogen-containing polymer or halogen-added polymer It becomes possible to improve the thermal stability of flame-retardant resin compositions consisting of

Claims (1)

[Claims] 1) A flame-retardant resin composition comprising a halogen-containing polymer or a halogen-added polymer mixed with a flame retardant in which the surface of zinc borate is coated with antimony or molybdenum metal oxide. thing. 2) In a halogen-containing polymer or a halogen-added polymer, the surface of zinc borate is coated with antimony or molybdenum metal oxide, and the metal oxide is surface-treated with a fatty acid, a fatty acid metal salt, a silane compound, or a titanate compound. A flame-retardant resin composition characterized by containing a flame retardant.