JP2014177593A - Flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve further the flame retardance of a flame-retardant resin composition using borax.SOLUTION: A flame-retardant resin composition comprises (A) a polyolefin resin, (B) a borate hydrate and at least one selected from (C-1) a copper salt of an acid having a pKa of 1-10 to water or a copper oxide, (C-2) a bismuth salt or a bismuth oxide and (C-3) a tellurate, a telluride or a tellurium oxide.

Description

  The present invention relates to a flame retardant resin composition.

Polyolefin resins are used in a wide range of fields, but since the resins themselves are flammable, their use may be restricted depending on the application, and various flame retardant treatments are being studied.
As a general flame retardant treatment, for example, a method of adding a halogen-containing compound or a method of adding a metal hydroxide is known. The halogen-containing compound is used for environmental safety such as generation of toxic gas. The metal hydroxide is required to be added in a large amount in order to exhibit sufficient flame retardancy, and as a result, the moldability and strength of the resin are reduced. There is.

Borates have long been known as additives that impart flame retardancy to materials, and zinc borate and the like are generally used as flame retardants for resins (Non-patent Document 1). However, a large amount of these flame retardants needs to be added in order to exhibit sufficient flame retardancy like metal hydroxides.
Further, sodium tetraborate hydrate known as borax is a colorless or white inorganic salt, and is known to be useful as a flame retardant for wood and paper. The use of this borax as a resin flame retardant has also been studied (for example, Patent Document 1).

  In order to add an additive such as a flame retardant to the resin, a method of adding the additive at a temperature equal to or higher than the melting point of the resin and melt-kneading is generally employed. Since borax has water of hydration, when it is added to the resin melt at a high temperature, water evaporates and vaporizes, and bubbles are generated in the resulting resin material. In Patent Document 2, by adding borax having a specific number of hydrates, it can be added to a molten thermoplastic resin without foaming, enabling industrial production. Further, addition of various inorganic oxides and inorganic metal salts as an inorganic filler to the composition has been studied and imparted flame retardancy.

  On the other hand, it is well known to those skilled in the art that metals such as copper, cobalt, manganese and iron deteriorate the synthetic resin, so-called "copper damage", and especially the addition of copper should be avoided. It has been considered (Non-Patent Document 2).

Japanese Patent Laid-Open No. 51-045145 JP 2011-162783 A

Flame retardant technology, p.60, etc., Hitoshi Nishizawa, 2003, Industrial Research Committee Air conditioning and sanitary engineering, 80 (1), p.69, Yoshito Otake, 2006

Although the technique described in Patent Document 2 exhibits flame retardancy, further improvement is demanded as flame retardancy in light of recent flame retardance standards (for example, UL-94). Further improvements in mechanical strength and moldability are also demanded.
An object of the present invention is to provide a method for further improving the flame retardancy of a flame retardant resin composition using a borate hydrate such as borax.

Patent Document 2 discloses that flame retardancy is improved by adding boric acid hydrate to a thermoplastic resin containing an inorganic filler. That is, it is considered that borate hydrate forms an oxygen barrier film effective for improving flame retardancy by vitrification in the vicinity of the combustion temperature of the thermoplastic resin and ceramicizing with an inorganic filler.
As a result of examining the resin composition presented in Patent Document 2 in more detail in order to achieve higher flame retardancy, the present inventors have found that once ignition occurs depending on the composition conditions, It has been found that combustion may be promoted instead of being reduced. Specifically, when the resin composition is in contact with flame, the borate hydrate and the inorganic filler are converted into ceramics and once self-extinguish, but after the crystallization water of the borate or inorganic filler is desorbed and diffused It becomes presumed that there is a case where the hole becomes a minute hole, and when the flame is contacted again, it functions as a so-called “candle core effect” and combustion may be promoted.

As a result of diligent research on this phenomenon, the present inventors have improved the flame retardancy by adding a specific compound to a flame retardant resin composition containing borate hydrate in a polyolefin resin. The present invention has been completed.
That is, the gist of the present invention is as follows.
[1] A flame retardant resin composition comprising (A) a polyolefin resin, (B) a borate hydrate, and at least one selected from the following (C-1) to (C-3): object,
(C-1) Acid and copper salt having a pKa of 1 to 10 in water, or copper oxide (C-2) bismuth salt, or bismuth oxide (C-3) tellurate, telluride or tellurium oxidation object
[2] The flame retardant resin composition according to the above [1], further comprising (D) an additive,
[3] The flame-retardant resin according to [2], wherein the additive (D) is any one of an inorganic hydroxide, a layered double hydroxide, or an inorganic carbonate other than copper carbonate and bismuth carbonate. Composition,
[4] The above [1] to [3], wherein the copper salt in (C-1) is any one of a carboxylate, an acetylacetonato complex, a phosphate, and a carbonate. The flame retardant resin composition according to any one of the above,
[5] The flame retardant composition according to any one of the above [1] to [4], wherein the borate hydrate (B) is an alkali metal borate hydrate. ,
[6] The flame retardancy according to any one of [1] to [5], wherein the borate hydrate (B) has a hydration number of 0.6 to 3.0. Resin composition,
[7] The above [1], wherein the content of (C-1) to (C-3) with respect to 100 parts by weight of the (A) polyolefin resin is 0.1 parts by weight or more and 10 parts by weight or less. The flame retardant resin composition according to any one of to [6],
[8] The flame retardant resin composition according to any one of [1] to [7], wherein the (A) polyolefin resin is an ethylene homopolymer and / or an ethylene copolymer. , Exist.

  According to this invention, the polyolefin resin composition which has a flame retardance higher than before was obtained by adding the said specific compound containing bismuth or tellurium. That is, a desired flame retardancy can be obtained even in a blend with less flame retardant than conventional, thereby suppressing a decrease in resin physical properties due to the addition of the flame retardant, and as a result, a flame retardant resin having good resin processability It is possible to provide a composition.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is limited to these contents. Instead, various modifications can be made within the scope of the gist.

<Flame-retardant resin composition>
As described above, the flame-retardant resin composition of the present invention is at least one selected from (A) a polyolefin resin, (B) a borate hydrate, and (C-1) to (C-3) below. It is characterized by including.
(C-1) Acid and copper salt having a pKa of 1 to 10 in water, or copper oxide (C-2) bismuth salt, or bismuth oxide (C-3) tellurate, telluride or tellurium oxidation object
Hereafter, it explains in full detail for every component requirement. Hereinafter, components selected from (C-1) to (C-3) may be collectively referred to as “component (C)”.

<(A) polyolefin resin>
The (A) polyolefin resin constituting the flame retardant resin composition of the present invention (hereinafter sometimes referred to as “component (A)”) is, for example, an α-olefin having 3 to 20 carbon atoms such as ethylene and propylene, Cyclic olefins having 3 to 20 carbon atoms (for example, cyclopentene, methylcyclopentene, dimethylcyclopentene, cyclohexene, methylcyclohexene, dimethylcyclohexene, norbornene and derivatives thereof, ethylidene and derivatives thereof), dienes (butadiene, isoprene, cyclobutadiene, etc.), Styrenes (for example, styrene, vinyltoluene, α-methylstyrene, etc.), cyclohexanes (for example, vinylcyclohexane, methylvinylcyclohexane, etc.), cyclopentanes (for example, vinylcyclopentane, methylvinylcyclo) A homopolymer or copolymer comprising a compound composed of carbon and hydrogen such as pentane and having at least one double bond, preferably ethylene, propylene, butadiene, and styrene It is a homopolymer or a copolymer containing at least one selected from

Examples of homopolymers include ethylene homopolymers (low density polyethylene, medium density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, etc.), propylene homopolymers (isotactic polypropylene, syndiotactic polypropylene, atactic polymer). Polypropylene, such as tic polypropylene and stereoblock polypropylene), polybutene, polymethylbutene, polymethylpentene, polybutadiene, polyisoprene, polystyrene, polyvinylcyclohexane, and the like.
Among these, an ethylene homopolymer and a propylene homopolymer are preferable, and an ethylene homopolymer is more preferable in that the effect of imparting flame retardancy is large.

Examples of the copolymer include an ethylene copolymer, a propylene copolymer, a butadiene copolymer, and a styrene copolymer.
Examples of the ethylene copolymer include a copolymer of ethylene and an α-olefin other than ethylene (hereinafter, ethylene-α-olefin copolymer); an ethylene-vinyl acetate copolymer; an ethylene-ethyl acrylate copolymer, An ethylene- (meth) acrylic acid ester copolymer such as an ethylene-butyl acrylate copolymer can be mentioned (here, (meth) acrylic acid means acrylic acid and methacrylic acid).

The α-olefin used in the ethylene-α-olefin copolymer is preferably an α-olefin having 3 to 20 carbon atoms. Specific examples include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and the like.
As the ethylene copolymer, an ethylene-α-olefin copolymer is preferable in that the effect of imparting flame retardancy is large, and an ethylene-propylene copolymer, an ethylene-1-butene copolymer, and ethylene-1-hexene are preferable. A copolymer is more preferable in terms of economy.

Examples of the propylene copolymer include a copolymer of propylene and an α-olefin other than propylene (hereinafter, propylene-α-olefin copolymer). Here, as the α-olefin, ethylene and an α-olefin having 4 to 20 carbon atoms are preferable, and specifically, ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene. , 1-octene and the like.
As the propylene copolymer, a propylene-α-olefin copolymer is preferable in that the effect of imparting flame retardancy is large.

Examples of the butadiene copolymer include acrylonitrile-butadiene copolymer.
Examples of the styrene copolymer include styrene-methyl methacrylate copolymer, styrene-acrylic acid copolymer, styrene-maleic anhydride copolymer, styrene-acrylonitrile copolymer, and styrene-butadiene-styrene block copolymer. Styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, ABS resin (polybutadiene or styrene-butadiene copolymer grafted with styrene and acrylonitrile, or styrene-acrylonitrile copolymer) Acrylonitrile-butadiene copolymer blend), AAS resin (acrylic rubber grafted with styrene and acrylonitrile), MBS resin (polybutadiene or styrene-butadiene copolymer Things down and methyl methacrylate was graft-copolymerized), and the like.
As the styrene copolymer, an ABS resin is preferable in that the effect of imparting flame retardancy is large.

The molecular weight of the polyolefin resin in the present invention is not particularly limited, but in terms of the balance between moldability and mechanical properties, the weight average molecular weight is usually 10,000 or more, and 2
It is more preferably at least 10,000, particularly preferably at least 40,000. For the same reason, the weight average molecular weight is usually 1,000,000 or less, preferably 700,000 or less,
Particularly preferred is 500,000 or less.

These polyolefin resins may be used alone or in combination of two or more.
The polyolefin resin is preferably an ethylene homopolymer, a propylene homopolymer, an ethylene copolymer, a propylene copolymer, or a styrene copolymer. Among these, an ethylene homopolymer, a propylene homopolymer, an ethylene copolymer, A propylene copolymer is more preferable in that the effect of imparting flame retardancy is large.

  Among these, ethylene homopolymer and / or ethylene copolymer is used in the sense that the value added as an industrial product is greatly increased by making the resin, which is highly flammable and does not easily form char when it burns, into a flame retardant. A coalescence is further preferred, and an ethylene homopolymer is most preferred.

<(B) Borate hydrate>
The (B) borate hydrate (hereinafter sometimes referred to as “component (B)”) constituting the flame retardant resin composition of the present invention is not particularly limited, and examples thereof include alkali metals and alkalis. Examples include earth metals, elements of Groups 4, 12, and 13 of the periodic table and ammonium borate hydrate.

Specifically, alkali metal salts such as lithium borate, sodium borate, potassium borate, cesium borate, alkaline earth metal salts such as magnesium borate, calcium borate, barium borate, zirconium borate, boron Examples thereof include zinc acid, aluminum borate, and ammonium borate.
Among them, alkali metal borate hydrate and alkaline earth metal borate hydrate are preferable, alkali metal borate hydrate is more preferable, and among alkali metal borate hydrates, sodium borate hydrate and Potassium borate hydrate is more preferred, and sodium borate hydrate is most preferred. This is because it is highly versatile and advantageous in terms of cost.

Moreover, among the alkaline earth metal borate hydrates, magnesium borate hydrate and borocalcium hydrate are more preferable, and magnesium borate hydrate is more preferable. This is because it is highly versatile and advantageous in terms of cost.
Sodium borate hydrate includes sodium tetraborate hydrate (Na ₂ B ₄ O ₇ · nH ₂ O), sodium octaborate hydrate (Na ₂ B ₈ O ₁₃ · nH ₂ O), excess Examples thereof include sodium borate (NaBO ₃ .nH ₂ O), and sodium tetraborate hydrate is more preferable.

Examples of potassium borate hydrate include potassium tetraborate hydrate (K ₂ B ₄ O ₇ .nH ₂ O).
The hydrate number (number of hydrates) n of the borate hydrate in the present invention is not particularly limited, but is usually 0.6 or more, preferably 0.7 or more, more preferably 0.8. Or more, more preferably 0.9 or more, and most preferably 1.0 or more. Moreover, it is 3.0 or less normally, Preferably it is 2.5 or less, More preferably, it is 2.0 or less.
When the amount is less than the lower limit value, the flame retardancy is not sufficiently exhibited. When the amount is more than the upper limit value, foaming may occur during mixing with the resin.
The number of hydrates of borate hydrate can be adjusted and used as appropriate by drying or hydrating commercially available borate hydrate or anhydride.

  The shape of the (B) borate hydrate used in the present invention is not particularly limited, but a particulate form is preferably used. The particle size is not particularly limited, but a smaller particle size is preferable because the dispersibility in the (A) polyolefin resin is further improved. For example, the particle size of (B) borate hydrate is preferably 10 μm or less, more preferably 5 μm or less in terms of volume average particle size measured by a laser diffraction method / scattering particle size distribution analyzer. Preferably it is 1 micrometer or less. However, this volume average particle diameter is usually 10 nm or more.

  The proportion of the (B) borate hydrate in the flame retardant resin composition of the present invention is not particularly limited, but is usually 1 part by weight or more, preferably 5 parts per 100 parts by weight of the polyolefin resin. It is at least 10 parts by weight, more preferably at most 100 parts by weight, preferably at most 80 parts by weight, more preferably at most 40 parts by weight. If this ratio is less than the above lower limit, the flame retardancy of the thermoplastic resin composition may be insufficient, and if it exceeds the upper limit, the moldability of the resulting flame retardant resin composition may be deteriorated, Furthermore, the mechanical strength of various molded products may be reduced.

<(C) component>
The component (C) constituting the flame retardant resin composition of the present invention is at least one selected from the following (C-1) to (C-3).
(C-1) Acid and copper salt having a pKa of 1 to 10 in water, or copper oxide (C-2) bismuth salt, or bismuth oxide (C-3) tellurate, telluride or tellurium oxidation object

<(C-1) Acid and Copper Salt or Copper Oxide with a pKa of 1 to 10 for Water>
In the (C-1) water used in the present invention, an acid and copper salt having a pKa of 1 or more and 10 or less, or a copper oxide (hereinafter sometimes referred to as “(C-1) component”), the acid and Examples of the copper salt include inorganic salts of copper, organic acid salts, and organic complexes of copper. The valence of copper may be either monovalent or divalent, but divalent salts are generally preferred from the standpoint of availability.

As the inorganic salt of copper, the pKa (pKa (H ₂ O)) with respect to water of the inorganic acid constituting the salt may be 1 or more and 10 or less. Specifically, copper (II) phosphate, copper phosphite (II), copper (II) chromate, copper (II) chromite, copper (I) thiocyanate, basic copper carbonate (II), etc., among which copper (II) phosphate and basic copper carbonate (II) is preferable in terms of availability and disposal.

  The acid salt of copper is not particularly limited as long as the pKa of the organic acid constituting the salt is 1 or more and 10 or less, but is usually a carboxylate. Specifically, copper (II) formate, copper (I) acetate, copper (II) acetate, copper (II) propionate, copper (II) butyrate, copper (II) stearate, copper (II) palmitate, oxalate Saturated fatty acid salts such as copper (II) succinate, copper (II) succinate, copper (II) fumarate, copper (II) citrate, copper (II) lactate; copper oleate (II), copper linoleate (II) ) And the like; and aromatic carboxylates such as copper (II) phthalate and copper (II) benzoate; Of these, copper (II) oxalate, copper (II) citrate, and copper (II) acetate are preferred in terms of industrial availability.

Examples of the organic complex of copper include an acetylacetonato copper (II) complex.
Examples of the copper oxide include copper (I) oxide and copper (II) oxide.
Of these copper salts, carboxylates, acetylacetonato complexes, phosphates, or carbonates are preferred in terms of industrial availability and cost.
These may be used alone or in combination of two or more.

<(C-2) Bismuth salt or bismuth oxide>
In the (C-2) bismuth salt or bismuth oxide (hereinafter sometimes referred to as “component (C-2)”) used in the present invention, examples of the bismuth salt include inorganic bismuth salts and organic bismuth salts. .
Specific examples of the inorganic bismuth salt include basic bismuth (III) carbonate, bismuth titanate (III), and bismuth (III) phosphate.

Organic bismuth salts include bismuth acetate (III), bismuth citrate (III), bismuth salts of carboxylic acids such as bismuth (III) neodecanoate, bismuth (III) hyposalicylate, and bismuth (gallium) gallate. And bismuth salts of aromatic carboxylic acids.
Examples of the bismuth oxide include bismuth oxide (III), bismuth carbonate oxide (III), and bismuth acetate acetate (III).

Of these, basic bismuth carbonate (III), bismuth phosphate (III), and bismuth oxide (III) are preferred in terms of industrial availability and handling, and bismuth phosphate (III), bismuth oxide ( III) is more preferred.
These may be used alone or in combination of two or more.

<(C-3) Tellurate, Telluride or Tellurium Oxide>
In the (C-3) tellurate, telluride or tellurium oxide (hereinafter sometimes referred to as "(C-3) component") used in the present invention, the tellurate (VI) metal salt is used as the tellurate. And tellurium (IV) acid metal salts.
Specifically, tellurium salts include tellurium (VI) metal salts such as sodium tellurium (VI) and potassium tellurium (VI); sodium tellurite (IV) and potassium tellurite (IV). And tellurium (IV) acid metal salts.
Examples of the telluride include zinc telluride, zirconium telluride, niobium telluride, antimony telluride, and bismuth (III) telluride.
Examples of the tellurium oxide include tellurium oxide (IV) (tellurium dioxide).
Among these, tellurium oxide (IV) and telluric acid (VI) metal salts are preferable, and tellurium oxide (IV) is more preferable in terms of industrial availability.
These may be used alone or in combination of two or more.

  Although the shape of the said (C) component used in this invention is not specifically limited, Preferably a particulate form is used. The particle size is not particularly limited, but a smaller particle size is preferable because the dispersibility in the (A) polyolefin resin is further improved. For example, the particle size of component (C) is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less in terms of volume average particle size measured with a laser diffraction method / scattering type particle size distribution analyzer. It is. However, this volume average particle diameter is usually 10 nm or more.

  The proportion of the component (C) in the flame retardant resin composition of the present invention is not particularly limited, but is usually 0.1 parts by weight or more, preferably 0.2 parts per 100 parts by weight of the polyolefin resin. Part by weight or more, more preferably 0.3 part by weight or more, and usually 10 parts by weight or less, preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and most preferably 2 parts by weight or less. If the blending amount is less than the lower limit, the effect of suppressing thermal decomposition may not be obtained. If the blending amount is more than the upper limit, thermal decomposition is suppressed, The durability of the resulting composition may be reduced.

  The proportion of the component (C) in the flame retardant resin composition is not particularly limited, but is usually 0.1 parts by weight or more, preferably 11 parts per 100 parts by weight of borate hydrate. Part by weight or more, usually 100 parts by weight or less, preferably 50 parts by weight or less, more preferably 20 parts by weight or less. If the blending amount is less than the lower limit, the effect of suppressing thermal decomposition may not be obtained. If the blending amount is more than the upper limit, thermal decomposition is suppressed, The durability of the resulting composition may be reduced.

The component (C) used in the present invention may be used as it is or may be subjected to a surface treatment. Specifically, as the surface treatment, a method of performing a surface treatment with an organic acid such as stearic acid or palmitic acid as described in JP-A-2005-048034 or a method described in JP-A-2006-160799 A film derived from the surface treatment agent may be formed on the surface of the metal compound by a method such as surface treatment with various silane coupling agents or titanic acid. Further, fine particles of inorganic oxides such as silica, alumina, and titania may be coated on the surface.

<(D) Additive>
If necessary, the resin composition of the present invention may further contain (D) additive (hereinafter sometimes referred to as (D) component). As the component (D), it is preferable to add various inorganic fillers because flame retardancy can be further improved. Inorganic fillers include inorganic hydroxides, layered double hydroxides, inorganic carbonates (other than copper carbonate and bismuth carbonate), inorganic oxides (other than copper oxide, bismuth oxide and tellurium oxide), molybdates, and 1 type or 2 types or more of inorganic compounds chosen from tungstate are mentioned, and any one of inorganic hydroxide, layered double hydroxide, or inorganic carbonate (other than copper carbonate and bismuth carbonate) is a small amount. Addition is preferable because the flame retardant effect is exhibited.

Examples of the inorganic hydroxide include hydroxides of alkali metals, alkaline earth metals, Group 4, Group 6, Group 12, and Group 13 elements of the periodic table.
Specific examples include lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide, zirconium hydroxide, molybdenum hydroxide, zinc hydroxide, and aluminum hydroxide.

  Among these, magnesium hydroxide, calcium hydroxide, zirconium hydroxide, zinc hydroxide, and aluminum hydroxide are preferable, and magnesium hydroxide and aluminum hydroxide are more preferable.

The layered double hydroxide is a conventionally known layered double hydroxide, which is generally represented by the following general formula, a hydroxide octahedral base layer similar to brucite, and an anion And an intermediate layer composed of interlayer water is alternately laminated.
[M ²⁺ _1-x M ³⁺ _x (OH ⁻ ) ₂ ] [A ⁿ⁻ _{x / n} · yH ₂ O]
Here, M ²⁺ is a divalent metal ion such as Mg, Mn, Fe, Co, Ni, Cu, or Zn, and M ³⁺ is a trivalent metal ion such as Al, Cr, Fe, Co, or In, and is a basic skeleton. A regular octahedral layer of hydroxide has a positive charge as a result of substituting some of the divalent metal ions with trivalent metal ions. Keep. Anion ^{A n-} is an intermediate layer _{^{Cl -, NO 3 -, CO}} 3 2-, COO - is an n-valent anion, such as, it can be replaced depending on the type. The most commonly used layered double hydroxide is hydrotalcite, and its structure is that part of Mg ²⁺ is replaced by Al ³⁺ and CO ₃ ²⁻ is present between the layers. Is a feature.

The layered double hydroxide may be either a synthetic product or a natural product. Specific examples thereof include hydrotalcite, hydrocalumite, and pyroolite. Among the layered double hydroxides, hydrotalcite is particularly preferable.
Examples of inorganic carbonates include carbonates of alkali metals, alkaline earth metals, Group 4 and Group 12 elements of the periodic table.

Specific examples include lithium carbonate, sodium carbonate, cesium carbonate, basic magnesium carbonate, calcium carbonate, basic calcium carbonate, barium carbonate, zirconium carbonate, basic zinc carbonate and the like.
Of these, basic magnesium carbonate, calcium carbonate, basic calcium carbonate, zirconium carbonate, and basic zinc carbonate are preferable, and basic magnesium carbonate is more preferable.

  Examples of the inorganic oxide include oxides of alkali metals, alkaline earth metals, Group 4, Group 6, Group 12, Group 13, Group 14 elements of the periodic table, and composite oxides thereof. It is done. Examples of the alkali metal oxide include sodium oxide, potassium oxide, cesium oxide and the like. Examples of the alkaline earth metal oxide include magnesium oxide, calcium oxide, and barium oxide.

Examples of the oxides of the elements of Groups 4, 6, 12, 13, and 14 of the periodic table include titanium oxide, zirconium oxide, molybdenum oxide, tungsten oxide, zinc oxide, boron oxide, and aluminum oxide. , Silicon oxide, tin oxide and the like.
Among these, preferable inorganic oxides are selected from sodium oxide, potassium oxide, magnesium oxide, calcium oxide, titanium oxide, zirconium oxide, molybdenum oxide, zinc oxide, boron oxide, aluminum oxide, silicon oxide, and these oxides. And a more preferable inorganic oxide is magnesium oxide, calcium oxide, titanium oxide, zirconium oxide, aluminum oxide, silicon oxide, and one selected from these oxides. A composite oxide containing the above oxide, and more preferable inorganic oxide is a composite oxide containing magnesium oxide, aluminum oxide, silicon oxide, and one or more oxides selected from these oxides, Most preferred is silicon oxide.

Examples of the molybdate include potassium molybdate, sodium molybdate, calcium molybdate, and ammonium molybdate. Among these, sodium molybdate and ammonium molybdate are preferable, and ammonium molybdate is more preferable.
Examples of ammonium molybdate include ammonium heptamolybdate (common name: ammonium molybdate) (NH ₄ ) ₆ Mo ₇ O ₂₄ · 4H ₂ O and ammonium octamolybdate (NH ₄ ) ₄ Mo ₈ O ₂₆ . Ammonium octamolybdate is preferred.

  Examples of the tungstate include potassium tungstate, sodium tungstate, calcium tungstate, ammonium metatungstate, ammonium paratungstate, and among them, sodium tungstate, ammonium metatungstate, and ammonium paratungstate are preferable. More preferred is ammonium paratungstate.

  The ratio of the additive (D) in the flame retardant resin composition of the present invention is not particularly limited, but is usually 10 parts by weight or more, preferably 20 parts by weight or more with respect to 100 parts by weight of the polyolefin resin. More preferably, it is 30 parts by weight or more, usually 200 parts by weight or less, preferably 120 parts by weight or less, more preferably 80 parts by weight or less. If this ratio is less than the above lower limit, the flame retardancy of the thermoplastic resin composition may be insufficient, and if it exceeds the upper limit, the moldability of the resulting flame retardant resin composition may be deteriorated, Furthermore, the mechanical strength of various molded products may be reduced.

The shape of the component (D) used in the present invention is not particularly limited, but the same shape as the components (B) and (C) described above can be used.
Moreover, the said (D) additive may be used as it is like (C) component, and may be used after surface treatment.

<(E) Other ingredients>
In the flame-retardant resin composition of the present invention, in addition to the above components (A) to (D), if necessary, (E) other components (hereinafter referred to as “(E)” as long as the object of the present invention is not impaired. You may mix | blend an "component."). Specifically, flame retardant aids such as nitrogen-containing compounds and polyhydric alcohols, phenolic, amine-based, sulfur-based antioxidants, stabilizers, ultraviolet absorbers, antistatic agents, crosslinking initiators, lubricants, An appropriate amount of one or more of various additives such as a softener, a filler and a colorant may be contained.

The content ratio of each component in the flame-retardant resin composition of the present invention is not particularly limited as long as it is a content ratio within the range that exhibits the effects of the present invention, but (B) component, (C) component, (D) Component, (E) As a total of component, (A) It is normally 10 weight part or more with respect to 100 weight part of polyolefin resin, Preferably it is 20 weight part or more, More preferably, it is 30 weight part or more, Usually 300 weight part or less, Preferably it is 220 weight part or less, More preferably, it is 150 weight part or less.
If this ratio is less than the above lower limit, the flame retardancy of the thermoplastic resin composition may be insufficient, and if it exceeds the upper limit, the moldability of the resulting flame retardant resin composition may be deteriorated, Furthermore, the mechanical strength of various molded products may be reduced.

<Method for producing flame retardant resin composition>
Although the manufacturing method of the flame-retardant resin composition of this invention is not specifically limited, (B) borate hydrate and (C) component with respect to (A) polyolefin resin, as needed ( It is preferable to knead and manufacture the component D).
The order of kneading is not particularly limited. For (A) polyolefin resin, (B) borate hydrate may be kneaded first, or (C) component may be kneaded first, You may knead | mix previously (D) component used as needed. Alternatively, (B) borate hydrate and component (C) may be kneaded at the same time, and then component (D) may be kneaded as necessary. (B) borate hydrate and (D) additive may be added. The component (C) may be kneaded after being previously kneaded, or the component (B), the component (C) and the component (D) may be kneaded at the same time.
Any of the constituent components may be kneaded in a lump or may be divided and kneaded.

In the present invention, the method of kneading each constituent material of the flame retardant resin composition is not particularly limited, and any known method can be used.
For example, there is a method in which each constituent material is added and kneaded in a state where the thermoplastic resin is heated and melted. In this case, if necessary, each constituent material may be added after being heated in advance.
The kneading apparatus used for kneading is not particularly limited as long as the object of the present invention can be achieved, and a general kneading apparatus such as a single screw extruder, a twin screw extruder, a Banbury mixer, a kneader, or a roll is used. be able to.

<Resin molding>
The flame-retardant resin composition of the present invention is formed by molding the above-mentioned flame-retardant resin composition of the present invention, and the molding method is not particularly limited, and includes pipe extrusion, film extrusion, sheet extrusion, Examples include extrusion molding such as wire coating, fiber, net, and transcast molding, calendar molding, injection molding, press molding, extrusion blow and injection blow, injection / extrusion blow, sheet blow, and blow molding such as cold parison method.
The resin molded body of the present invention is suitable for various applications because it exhibits extremely good flame retardancy and can be added to any color as required.

Examples of the application include electric wire coating, automobile members, electronic devices / home appliances, packaging materials / containers, building materials, machine parts, daily necessities, agricultural materials, and the like.
For example, insulated wires, electronic device wiring wires, automotive wires, device wires, power cords, outdoor power distribution insulated wires, power cables, control cables, communication cables, instrumentation cables, signals It can be expected to be used as a covering material for various electric wires and cables such as industrial cables, moving cables, and marine cables, household wiring, and wire harnesses for automobiles.

As automobile members, for example, it can be expected to be used as members such as instrument panels, bumpers, fuel tanks, tires, wiper blades, tire chains, lamps (housing, lenses, covers), and outer plates.
As electronic devices and household electrical appliances, for example, it can be expected to be used as structural parts such as housings, substrates, chassis and panels, and mechanical parts such as gears and pulleys.

As a packaging material / container, use as a container, a crate, a large container, etc. can be expected.
As building materials, it can be expected to be used as, for example, tents, artificial grass, wallpaper, curtains, curtain rails, soundproofing and heat insulating materials.
As mechanical parts, utilization as gears, wheels, bearings and the like can be expected, for example.
Daily commodities include, for example, furniture such as storage furniture, shelves, tables, chairs, household items such as buckets, scoops, chairs, step stools, kitchenware such as cutting boards, trays, and containers, bathrooms such as washbasins, chairs, and slippers. Goods, bags, shoes, etc.

EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not restrict | limited by a following example, unless the summary is exceeded.
The materials used in the following Examples and Comparative Examples and the heat resistance test methods of the obtained resin compositions are as follows.

<Material>
[(A) Polyolefin resin]
(A) As the polyolefin resin, a polyethylene resin “Novatech LL UJ960” (JIS K6922-2 melt flow rate: 5 g / 10 min) manufactured by Nippon Polyethylene Co., Ltd. was used.

[(B) borate compound]
(B) As the borate compound, the following compounds were used.
1070.4 g of sodium tetraborate decahydrate made by Wako Pure Chemical Industries, Ltd. was put in a stainless steel tray dish and dried at 200 ° C. for 1 hour in a constant temperature dryer (TABAI gear oven, GPHH-200). 645.45 g of sodium tetraborate n hydrate was obtained. The amount of hydrate after drying determined from the weight loss was n = 1.6. This dried borate hydrate was used after pulverizing with a ball mill.

[Component (C)]
As the component (C), various copper salts, copper oxides, bismuth compounds, and tellurium oxides listed in Table 1 were added.
[(D) Additive]
(D) As an additive, magnesium hydroxide “Kisuma 5A” manufactured by Kyowa Chemical Industry Co., Ltd. was used.

<Creation of specimen>
The obtained resin composition was molded into a plate of 125 mm × 13 mm × 3 mm at 180 ° C. by hot pressing to obtain a test piece.
<Combustion test>
About the obtained test piece, the flame retardance test based on the conditions of the 20 mm vertical combustion test prescribed | regulated to UL-94 was implemented.

Specifically, the test piece (molded body) was set up vertically and subjected to indirect flame at the lower end with a methane gas burner for 10 seconds. At that time, a burner conforming to ASTM D5025 was used, methane gas was supplied to the burner at 105 ml / min, and the burner was adjusted to a blue flame having a height of 20 mm ± 1 mm. The time from the start of flame contact to self-extinguishing (extinguishing before the test piece burns out) or the test piece burns out and the combustion is completed is defined as the combustion duration time.
Each test piece was subjected to flame contact twice, and flame retardancy was judged from the results according to the following criteria.

<Judgment criteria for combustion test results>
(Double-circle): The combustion continuation time at the time of the 1st flame contact and the 2nd flame contact both is 20 seconds or less.
○: Combustion duration at the time of the first flame contact is 20 seconds or less, and at the time of the second flame contact, the test piece is extinguished without sliding off or burning out, and the combustion duration time is within 2 minutes.
(Triangle | delta): The combustion continuation time at the time of the 1st flame contact is 20 second or less, Comprising: At the time of the 2nd flame contact, it corresponds to either of the following a) -c).
a) A sample piece slides down.
b) Burned out.
c) Combustion duration exceeds 2 minutes.
X: One corresponding to one of the following a) to c) at the time of the first flame contact.
a) A sample piece slides down.
b) Burned out.
c) Combustion duration exceeds 20 seconds.

Example 1
100 parts by weight of polyethylene resin (“Novatech LL UJ960” manufactured by Nippon Polyethylene Co., Ltd.), 20 parts by weight of sodium tetraborate (n = 1.6), magnesium hydroxide “Kisuma 5A” (manufactured by Kyowa Chemical Industry Co., Ltd.) 79 In addition to 1 part by weight of copper oxalate (II) 0.5 hydrate (manufactured by Wako Pure Chemical Industries, Ltd.), 180 ° C., 80 revolutions / minute using a Toyo Seiki Lab Plast Mill And kneaded for 4 minutes to obtain a resin composition. The obtained resin composition was molded into a plate of 125 mm × 13 mm × 3 mm at 180 ° C. by hot pressing to obtain a test piece. The combustion test was performed using the obtained test piece. The results are shown in Table 1.

(Comparative Example 1)
100 parts by weight of polyethylene resin (“Novatech LL UJ960” manufactured by Nippon Polyethylene Co., Ltd.), 20 parts by weight of sodium tetraborate (n = 1.6), and magnesium hydroxide “Kisuma 5A” (manufactured by Kyowa Chemical Industry Co., Ltd.) 80 In addition, the resin composition was obtained by kneading at 180 ° C. and 80 rpm for 4 minutes using a Laboplast mill manufactured by Toyo Seiki. The obtained resin composition was molded into a plate of 125 mm × 13 mm × 3 mm at 180 ° C. by hot pressing to obtain a test piece. The combustion test was performed using the obtained test piece. The results are shown in Table 1.
In addition, the resin composition shown in Comparative Example 1 is the same as the resin composition described in Japanese Patent Application Laid-Open No. 2011-162783 and Example 14.

(Comparative Examples 2 and 3)
In place of the copper (II) oxalate 0.5 hydrate which is the component (C) of Example 1, oxalic acid (manufactured by Nacalai Tesque) or “flame stub NOR116FF” which is a hindered amine additive (BASF) Except that 1 part by weight was added, a resin composition was prepared in the same manner as in Example 1, and a combustion test was performed after preparing a test piece. The results are shown in Table 1.

(Examples 2-9, Comparative Examples 4-14)
Resin composition as in Example 1 except that 1 part by weight of component (C) listed in Table 1 was added instead of component (C) copper oxalate (II) 0.5 hydrate. The product was prepared, the obtained resin composition was prepared, and after making a test piece, a combustion test was conducted. The results are shown in Table 1.

As is clear from the results shown in Table 1, the flame retardancy is greatly improved by blending (B) borate hydrate and any of the components (C-1) to (C-3) into the polyolefin resin. It can be seen that
In the present invention, it has not yet been clarified why the flame retardancy is improved by adding a small amount of a specific copper salt, copper oxide, bismuth compound or tellurium compound, but it is estimated as follows. Is done.

  Japanese Patent Application Laid-Open No. 2011-162783 proposes a resin composition containing a thermoplastic resin, a borate compound, and an inorganic filler. As a mechanism for improving the flame retardancy of this resin composition, borate hydrate is vitrified in the vicinity of the combustion temperature of the thermoplastic resin, and is effective for improving the flame retardancy by being ceramicized with an inorganic filler. This is probably because an oxygen blocking film is formed.

The resin composition of the above prior art has a very high self-extinguishing property at the time of the first flame contact in the combustion test in UL-94 and is difficult to ignite even at the second time of the flame contact.
However, as a result of the inventors' investigation, it has been found that once ignition occurs at the time of the second flame contact, the flame does not shrink with time, and combustion may be accelerated.
As described in the examples of Table 1, by adding the components (C-1) to (C-3), it was found that combustion was not promoted even in the second flame contact with UL-94. It was.

If copper, bismuth, or tellurium that is not zero-valent is present, a dehydrogenation reaction proceeds when the resin is thermally decomposed, thereby carbonizing the resin. It is considered that a good oxygen-blocking film that does not exhibit the “candle core effect” can be formed by the carbide (char) plugging the minute holes described above.
Although it is already known that char formation is effective for flame retardancy, it is necessary to add a char forming agent or the like to cover the combustion surface of the resin with char. However, in the present invention, only a small hole in the ceramicized borate glass film is plugged to form a good oxygen barrier film, so a small amount of char forming agent is sufficient. Moreover, since copper, bismuth, and tellurium are themselves oxidation catalysts, the dehydrogenation reaction (char-forming reaction) is considered to proceed catalytically. It is thought.

  In addition, strong acid salts of copper, such as copper nitrate, have a superior thermal decomposition reaction than char, so charring is not sufficient, and as a result, suppression of combustion promotion due to the "candle core effect" is suppressed. Is not considered possible.

  According to the present invention, it is possible to obtain a polyolefin resin composition having higher flame retardancy than conventional, even in light of recent flame retardancy standards (for example, UL-94), and it is difficult to have good resin processability. It is possible to provide a flammable resin composition.

Claims (8)

A flame retardant resin composition comprising (A) a polyolefin resin, (B) a borate hydrate, and at least one selected from the following (C-1) to (C-3).
(C-1) Acid and copper salt having a pKa of 1 to 10 in water, or copper oxide (C-2) bismuth salt, or bismuth oxide (C-3) tellurate, telluride or tellurium oxidation object   The flame retardant resin composition according to claim 1, further comprising (D) an additive.   The flame retardant resin composition according to claim 2, wherein the additive (D) is any one of an inorganic hydroxide, a layered double hydroxide, or an inorganic carbonate other than copper carbonate and bismuth carbonate.   The copper salt in (C-1) is any one of carboxylate, acetylacetonato complex, phosphate, or carbonate, according to any one of claims 1 to 3. The flame-retardant resin composition as described.   The flame retardant composition according to any one of claims 1 to 4, wherein the borate hydrate (B) is an alkali metal borate hydrate.   The flame retardant resin composition according to any one of claims 1 to 5, wherein the hydrate number of the (B) borate hydrate is 0.6 or more and 3.0 or less.   The content of (C-1) to (C-3) with respect to 100 parts by weight of the (A) polyolefin resin is 0.1 parts by weight or more and 10 parts by weight or less. The flame-retardant resin composition according to claim 1.   The flame retardant resin composition according to any one of claims 1 to 7, wherein the (A) polyolefin resin is an ethylene homopolymer and / or an ethylene copolymer.