JP2014201626A - Flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition having high incombustibility while reducing the amount of addition of various kinds of flame retardants without using a halogen compound.SOLUTION: Potassium carbonate and a specific compound are blended into a thermoplastic resin so as to improve incombustibility. That is, a flame-retardant resin composition contains (A) the thermoplastic resin, (B) the potassium carbonate, and (C) metalhydroxide or phosphates. Preferably, the flame-retardant resin composition further contains (D) polyalcohol.

Description

  The present invention relates to a flame retardant resin composition.

Thermoplastic resins such as polyolefin resins are softened by heating, so that various additives can be easily added and molded, and are widely used for general purposes. However, since thermoplastic resins are generally flammable, their use may be limited 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.

  On the other hand, carbonates are known as flame retardants, and lithium carbonate, calcium carbonate, magnesium carbonate and the like are used (Non-Patent Document 1). Moreover, in patent document 1, adding carbonate with carbon to polyolefin resin is described, and various carbonates are illustrated.

JP 2011-195561 A

Flame retardant technology, p. 73 and p. 133, Hitoshi Nishizawa, 2003, Industrial Research Committee Scientific approach to flame retardancy of electronic and electrical equipment materials, p. 358, Kunihiko Takeda, 2004, Technical Information Association

However, halogen-containing compounds tend to be restricted in use as flame retardants due to environmental safety considerations such as generation of toxic gases. The metal hydroxide needs to be added in a large amount in order to exhibit sufficient flame retardancy, and as a result, there is a problem that moldability and strength of the resin are lowered.
In general, carbonates are less flame retardant than hydroxides that easily form hydrates such as aluminum hydroxide and magnesium hydroxide. For example, Non-Patent Document 2 shows that even when 150 parts by weight of calcium carbonate is blended with polypropylene, the oxygen index is not significantly improved. Further, in Patent Document 1, 24 parts by weight of magnesium carbonate used as a flame retardant is added to 100 parts by weight of the resin.

In other words, in order to impart sufficient flame retardancy with carbonates, there is a problem in that it must be blended in a larger amount than metal oxides such as magnesium hydroxide.
The present invention provides a resin composition exhibiting high flame retardancy while reducing the addition amount of various flame retardants without using a halogen compound.

As a result of intensive studies, the present inventors have found that flame retardancy is improved by adding potassium carbonate and a specific compound to a thermoplastic resin, resulting in the present invention.
That is, the gist of the present invention is as follows.
[1] A flame retardant resin composition comprising (A) a thermoplastic resin, (B) potassium carbonate, and (C) a metal hydroxide or a phosphate,
[2] The flame-retardant resin composition according to [1], further comprising (D) a polyhydric alcohol,
[3] The flame retardant resin composition as described in [1] or [2] above, wherein the thermoplastic resin (A) is a polyolefin resin.
[4] Any of the above [1] to [3], wherein (B) potassium carbonate is 0.1 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of (A) thermoplastic resin. 1. The flame retardant resin composition according to 1.

  According to this invention, the thermoplastic resin composition which has a flame retardance higher than before was obtained by making a thermoplastic resin contain a metal hydroxide or phosphates, and potassium carbonate. That is, the desired flame retardancy can be obtained 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 composition having good resin processability. It is possible to provide.

  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 characterized by containing (A) a thermoplastic resin, (B) potassium carbonate, and (C) a metal hydroxide or phosphate.
Hereafter, it explains in full detail for every component requirement.

<(A) Thermoplastic resin>
The (A) thermoplastic resin constituting the flame retardant resin composition of the present invention (hereinafter sometimes referred to as “component (A)”) is not particularly limited as long as it is a thermoplastic synthetic resin. Resin, polyester resin, polyamide resin, acrylic resin, vinyl resin, polycarbonate resin, polyurethane resin, acetal resin, synthetic rubber, and the like. One of these resins may be used alone, or a different resin type or the same type of resin may be used. Two or more types of resin types may be used in combination.
Among the above-mentioned (A) thermoplastic resins, polyolefin resins are preferred because the resin itself has high combustibility and the flame retardancy improving effect of the present invention is remarkable.

<Polyolefin resin>
Examples of the polyolefin resin in the present invention include α-olefins having 2 to 20 carbon atoms such as ethylene and propylene, and cyclic olefins having 3 to 20 carbon atoms (for example, cyclopentene, methylcyclopentene, dimethylcyclopentene, cyclohexene, methylcyclohexene, dimethylcyclohexene, Norbornene and its derivatives, ethylidene and its derivatives), dienes (such as butadiene, isoprene and cyclobutadiene), styrenes (such as styrene, vinyltoluene and α-methylstyrene), vinylcyclohexanes (such as vinylcyclohexane and methylvinyl) Cyclohexane, etc.), vinylcyclopentanes (eg, vinylcyclopentane, methylvinylcyclopentane, etc.), etc., having at least one double bond Homopolymer or copolymer having a hydrocarbon compound as a monomer, preferably a homopolymer or copolymer containing at least one selected from ethylene, propylene, butadiene, and styrene as a monomer It is.

Examples of homopolymers include ethylene homopolymers (low density polyethylene, medium density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, etc.), propylene homopolymer, butene homopolymer, methylbutene homopolymer, methylpentene homopolymer. Examples thereof include a polymer, a butadiene homopolymer, an isoprene homopolymer, a styrene homopolymer, and a vinylcyclohexane homopolymer.
Of these, ethylene homopolymers and propylene homopolymers are preferred in that the effect of imparting flame retardancy is great.

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-hexene, 4-methyl-1-pentene, 1-octene, 1-butene, 1-pentene 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-hexene, 4-methyl-1-pentene, 1-octene, 1-butene. , 1-pentene and the like.
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.
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, and more preferably an ethylene homopolymer, a propylene homopolymer, an ethylene copolymer. And a propylene copolymer. This is because the effect of imparting flame retardancy is great. Among them, ethylene homopolymer, ethylene copolymer, from the meaning that the added value as an industrial product is greatly increased by making the resin, which is highly combustible and does not easily form char when it burns, to increase the added value as an industrial product, Propylene homopolymer is preferred.

The molecular weight of the thermoplastic resin (A) 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.

<(B) Potassium carbonate>
Both (B) potassium carbonate (hereinafter sometimes referred to as “component (B)”) constituting the flame-retardant resin composition of the present invention can be used for both synthetic products and commercial products.
The shape of (B) potassium carbonate used in the present invention is not particularly limited, and both powder and particulates can be used, and particulates are preferably used. A smaller particle size of potassium carbonate is preferable because dispersibility in the resin is further improved. The specific particle size is not particularly limited, but is usually 10 nm or more and 10 μm or less, preferably 5 μm or less in terms of volume average particle size measured by a laser diffraction method / scattering type particle size distribution measuring device, and more preferably Preferably it is 1 micrometer or less.

Although the purity of (B) potassium carbonate used by this invention is not specifically limited, Usually, it is 80% or more, Preferably it is 90% or more, More preferably, it is 95% or more. There is no particular upper limit, and it is usually 100% or less. If the purity is too lower than the lower limit, the amount of potassium carbonate added may increase to improve flame retardancy.
Further, (B) potassium carbonate may be a hydrate or an anhydride, and the number of hydrates is not limited in the hydrate, and commercially available potassium carbonate hydrate or The anhydride can be dried or hydrated to adjust the number of hydration as appropriate.

  The proportion of (B) potassium carbonate 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 0.8 parts per 100 parts by weight of the polyolefin resin. It is 2 parts by weight or more, more preferably 0.3 part by weight or more, and usually 10 parts by weight or less, preferably 8 parts by weight or less, more preferably 5 parts by weight or less. If this ratio is too small than the above lower limit, the flame retardancy of the thermoplastic resin composition may be insufficient, and if it is more than the above upper limit, the moldability of the obtained flame retardant resin composition. May worsen, and the mechanical strength of various molded products may decrease. Further, there is a concern that the auxiliary combustion catalytic effect of potassium carbonate, which will be described later, has priority over the effect of the present invention.

The potassium carbonate (B) used in the present invention may be used as it is or may be subjected to a surface treatment. Specifically, as the surface treatment, the surface may be coated with an organic acid such as stearic acid or palmitic acid as described in JP-A-2005-048034, and described in JP-A-2006-160979. A surface treatment may be performed with various silane coupling agents, titanic acid or the like, and a film derived from the treatment agent may be formed on the surface of the metal compound. Further, fine particles of inorganic oxides such as silica, alumina, and titania may be coated on the surface.

In general, inorganic hydrates such as carbonates are considered to be flame retardant because of the endotherm when crystal water is desorbed and vaporized and the dilution effect of the vaporized water. In other words, since the decomposition temperature of carbonate is higher than the decomposition temperature of resin, flame resistance is not obtained by decomposition of carbonate, but rather the effect of carbonate having crystal water like inorganic hydrate. Conceivable.
However, among the carbonates, potassium carbonate usually does not have much crystal water, so the above-mentioned effect cannot be expected. Furthermore, since potassium carbonate itself is known as an auxiliary catalyst, it is considered that adding potassium carbonate rather promotes combustion. For example, sugar cubes do not burn even when lit, but they can easily burn when ash is added, which is considered to be an auxiliary combustion effect due to potassium carbonate contained in the ash. Similarly, charcoal also exhibits ignitability due to the effect of potassium carbonate, and the fact that the fire rope of the fire gun does not disappear is also regarded as an auxiliary combustion catalytic effect of potassium carbonate.

The reason why the effect of potassium carbonate as an auxiliary combustion catalyst is not clear, but focusing on the phenomenon that charcoal ignitability improves, dehydrogenation of charcoal is promoted by potassium carbonate, and the generated hydrogen gas burns. It is presumed that charcoal is easy to ignite.
However, it discovered that high flame retardance was expressed by using potassium carbonate together with the following (C) component. Although the reason why the flame retardancy is improved by the coexistence of the component (C) of the present invention and potassium carbonate has not yet been clarified, the following mechanism is conceivable.

It is considered that a thermoplastic resin is more likely to undergo a dehydrogenation reaction with potassium carbonate than charcoal. And since thermoplastic resins, especially polyolefin resins, are easily pyrolyzed regardless of the presence of potassium carbonate, the dehydrogenation reaction of the thermoplastic resin promotes the char formation rather than the combustion promoting effect. By doing so, it is presumed that an effect of making it flame-retardant can be obtained.
That is, in the present invention, it is presumed that the char formation effect is further imparted by making the thermoplastic resin coexist with potassium carbonate and the component (C) described below, and that the thermoplastic resin exhibits flame retardancy.

<(C) component>
(C) component which comprises the flame-retardant resin composition of this invention is a metal hydroxide or phosphates.

<Metal hydroxide>
Examples of the metal hydroxide used in the present invention include alkali metals, alkaline earth metals, hydroxides of 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 in terms of imparting flame retardancy, and magnesium hydroxide and aluminum hydroxide are highly effective in imparting flame retardancy and are inexpensive. In some respects, it is more preferable, and magnesium hydroxide is most preferable.
The proportion of the metal hydroxide in the flame retardant resin composition of the present invention is not particularly limited, but is usually 20 parts by weight or more, preferably 30 parts by weight or more, based on 100 parts by weight of the polyolefin resin. The amount is preferably 40 parts by weight or more, usually 300 parts by weight or less, preferably 240 parts by weight or less, more preferably 190 parts by weight or less. If the amount is less than the lower limit, sufficient flame retardancy may not be obtained, and if the amount is more than the upper limit, the processability and strength of the resin may be reduced. There is.

The main reason why metal hydroxide exhibits flame retardancy is considered to be due to combustion suppression by dehydration endothermic effect and dilution effect by water vapor evaporated from metal hydroxide.
In the present invention, the reason why flame retardancy is improved by containing a metal hydroxide together with potassium carbonate is not yet clear, but it is effective even with the addition of a very small amount of potassium carbonate. The effect is considered to be limited, and it is presumed that the co-existence of potassium carbonate promotes the char formation effect, thereby improving the flame retardancy.
By using a metal hydroxide and potassium carbonate in combination, flame retardancy can be improved, so that the amount of metal hydroxide used can be reduced and the strength of the resin composition can be improved.

<Phosphate>
Examples of the phosphates used in the present invention include phosphates, condensed phosphates, phosphites and condensates thereof, hypophosphites, etc., but the stability and availability of compounds, decomposition Phosphate is most preferable in terms of low gas toxicity.
Examples of the condensed phosphate include pyrophosphate and polyphosphate.
Among the phosphates, ammonium salts such as ammonium phosphate, ammonium pyrophosphate, and ammonium polyphosphate, and salts with melamine such as melamine phosphate, melamine pyrophosphate, and melamine polyphosphate are preferable. More preferred is an ammonium salt, and ammonium polyphosphate is more preferred from the standpoint of thermal stability when the phosphates are kneaded into a polyolefin resin or when a flame retardant resin composition is molded.

  The proportion of phosphates in the flame retardant resin composition of the present invention is not particularly limited, but is usually 10 parts by weight or more, preferably 15 parts by weight or more, more preferably 100 parts by weight of polyolefin resin. Is 20 parts by weight or more, usually 160 parts by weight or less, preferably 100 parts by weight or less, more preferably 60 parts by weight or less. When the blending amount is less than the lower limit value, sufficient flame retardancy may not be obtained, and when the blending amount is too much greater than the upper limit value, the resin hardness decreases and the water resistance decreases, There may be an increase in cost.

The main reason why phosphates exhibit flame retardancy is thought to be due to char formation in the solid phase, formation of foamable char, and the like.
In the present invention, the reason why flame retardancy is improved by containing phosphates together with potassium carbonate is not yet clear, but it is presumed that char formation is performed more effectively and flame retardancy is improved. .
By using phosphates and potassium carbonate in combination, flame retardancy can be improved, so the amount of phosphates used can be suppressed and the environmental burden can be reduced.

These (C) components may be used singly or plural kinds of (C) components may be mixed and used in an arbitrary ratio.
The shape of the component (C) used in the present invention is not particularly limited, and any of a particulate form and a powder form can be used, but a particulate form is preferably used.

  The particle size of the component (C) is not particularly limited, but a smaller one is preferable because dispersibility in the resin is further improved. For example, the particle size of the metal hydroxide is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm in terms of a volume average particle size measured by a laser diffraction method / scattering type particle size distribution analyzer. It is as follows. However, this volume average particle diameter is usually 10 nm or more.

  (B) component and (C) component used by this invention can be used by arbitrary mixing ratios, However, Usually, the quantity of (B) potassium carbonate is used less than (C) component. Component (B) is usually 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, usually 20 parts by weight or less, preferably 10 parts by weight per 100 parts by weight of component (C). Less than parts by weight. When it is too smaller than the lower limit, the flame retardancy improving effect may not be sufficiently obtained, and when it is larger than the upper limit, the components (B) and (C) in the resin composition The total amount of (that is, the amount of flame retardant) increases, and the mechanical properties and the like may decrease.

The component (C) used in the present invention may be used as it is or after surface treatment. Specifically, as the surface treatment method, the surface may be coated with an organic acid such as stearic acid or palmitic acid as described in JP-A-2005-048034. The surface treatment may be performed with various silane coupling agents, titanic acid, etc. as described in 1 above, and a film derived from the treatment agent may be formed on the surface of the metal compound. Further, fine particles of inorganic oxides such as silica, alumina, and titania may be coated on the surface.

<(D) Polyhydric alcohol>
The flame retardant resin composition of the present invention may further contain (D) a polyhydric alcohol.
In particular, the (D) polyhydric alcohol is preferably contained in a resin composition containing phosphates as the component (C).
(D) The resin composition containing a polyhydric alcohol is known as a flame retardant exhibiting high flame retardancy, and is called an Intumescent flame retardant. It is considered that a foamed char having a high oxygen blocking effect is generated by a synergistic effect with the component (C), and exhibits a very high flame retardant effect.
However, the Intumescent system is disadvantageous in terms of cost because the polyhydric alcohol added is expensive and the Intumescent flame retardant itself is expensive.
The flame retardant resin composition of the present invention is preferable because addition of potassium carbonate can reduce the amount of (D) polyhydric alcohol added and can constitute a highly flame retardant resin composition.

The reason why flame retardancy is improved by adding potassium carbonate is not clear, but by adding potassium carbonate, char formation by potassium carbonate is further promoted in addition to foamed char that is thought to be generated in the Intumescent system. It is estimated that flame retardancy is improved.
(D) Although the valence of the polyhydric alcohol is not particularly limited, it is usually 3 or more, preferably 4 or more, and the larger the value, the higher the decomposition temperature is. However, it is usually 20 or less in terms of industrial availability. Preferably it is 12 or less, More preferably, it is 8 or less, More preferably, it is 6 or less.
The (D) polyhydric alcohol may be a condensate or a polymer thereof.

  (D) The polyhydric alcohol preferably has a tertiary carbon or a quaternary carbon in its molecule, and more preferably has a quaternary carbon, in that the decomposition temperature becomes high. Specific examples of the compound having a tertiary carbon or quaternary carbon structure include pentaerythritol, dipentaerythritol, tripentaerythritol, tetrapentaerythritol, adamantanetriol, gallic acid, resveratrol, and the like. From the viewpoint of industrial availability, pentaerythritol, dipentaerythritol, and gallic acid are preferable, pentaerythritol and dipentaerythritol are more preferable, and pentaerythritol is most preferable.

The ratio of the (D) polyhydric alcohol in the flame retardant resin composition of the present invention is not particularly limited. However, when the component (C) is a metal hydroxide, the amount is 100 parts by weight of the thermoplastic resin. On the other hand, the total amount with the metal hydroxide is usually 20 parts by weight or more, preferably 30 parts by weight or more, more preferably 40 parts by weight or more, usually 300 parts by weight or less, preferably 240 parts by weight or less, more preferably 190 parts by weight. Less than parts by weight.
When the component (C) is a phosphate, the total amount with the phosphate is usually 10 parts by weight or more, preferably 15 parts by weight or more, more preferably 20 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The amount is usually 150 parts by weight or less, preferably 100 parts by weight or less, and more preferably 60 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.

When the component (C) is a metal hydroxide, the ratio of the (D) polyhydric alcohol to the component (C) is usually 5 parts by weight or more, preferably 7 parts by weight or more with respect to 100 parts by weight of the metal hydroxide. More preferably, it is 9 parts by weight or more, usually 100 parts by weight or less, preferably 70 parts by weight or less, more preferably 50 parts by weight or less.
When component (C) is a phosphate, it is usually 10 parts by weight or more, preferably 20 parts by weight or more, more preferably 40 parts by weight or more, and usually 900 parts by weight or less, based on 100 parts by weight of the phosphates. The amount is preferably 400 parts by weight or less, more preferably 250 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. It is also disadvantageous in terms of cost.

  In the resin composition of the present invention, in addition to the above components (A) to (D), if necessary, (E) other components (hereinafter referred to as “component (E)”) as long as the object of the present invention is not impaired. May be blended). Specifically, flame retardant aids such as inorganic oxides, layered double hydroxides, nitrogen-containing compounds, antioxidants such as phenols, amines, and sulfurs, stabilizers, ultraviolet absorbers, antistatic agents, An appropriate amount of one or more of various additives such as a crosslinking initiator, a lubricant, 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 thermoplastic resins, Preferably it is 20 weight part or more, More preferably, it is 30 weight part or more, Usually, 300 weight part or less , Preferably 220 parts by weight or less, more preferably 150 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.

<Method for producing flame retardant resin composition>
Although the manufacturing method of the flame retardant resin composition of the present invention is not particularly limited, (B) potassium carbonate and (C) component with respect to (A) thermoplastic resin, and (D) many It is preferable to manufacture by kneading arbitrary components such as a monohydric alcohol.
The order of kneading is not particularly limited, and (B) potassium carbonate or (C) component may be kneaded first with respect to (A) thermoplastic resin, as necessary. The component (D) used accordingly may be kneaded first. Alternatively, the component (B) and the component (C) may be kneaded at the same time, and then the component (D) may be kneaded as necessary. The component (B) and the additive (D) may be kneaded first (C 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 can be molded as a resin molded body using various molding means, and the molding method is not particularly limited. Pipe extrusion, film extrusion, sheet extrusion, wire coating Extrusion molding such as fiber, net and transcast molding, calendar molding, injection molding, press molding, extrusion blow or injection blow, injection / extrusion blow, sheet blow, blow molding such as cold parison method, and the like.

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) Thermoplastic resin]
(A) The following were used as the thermoplastic resin.
(A-1) Polyethylene resin: Polyethylene resin “Novatec LL UJ960” (JIS K6922-2 melt flow rate: 5 g / 10 min) manufactured by Nippon Polyethylene Corporation.
(A-2) Polypropylene resin: “NOVATEC PP MA3” manufactured by Nippon Polypro Co., Ltd. (JIS K7210: 1999 Melt flow rate: 11 g / 10 min)
[(B) Potassium carbonate]
(B) As potassium carbonate, potassium carbonate (anhydride) manufactured by Wako Pure Chemical Industries, Ltd. was used.
[Component (C)]
As the metal hydroxide and phosphates of the component (C), the following were used.

(C-1) Magnesium hydroxide: manufactured by Kyowa Chemical Industry Co., Ltd., trade name “Kisuma 5A”
(C-2) Ammonium polyphosphate manufactured by Budenheim, trade name “TERRAJU C
30 "
[(D) Polyhydric alcohol (D) As the polyhydric alcohol, pentaerythritol manufactured by Kanto Chemical Co., Inc. was used.

Moreover, the following were used for each comparative example. (Hereinafter referred to as component (F)).
(F-1) Lithium carbonate: Wako Pure Chemical Industries, Ltd. (F-2) Sodium carbonate: Kanto Chemical Co., Inc. (F-3) Magnesium carbonate: Nacalai Tesque, Inc., basic magnesium carbonate (F-4) Calcium carbonate: Kishida Chemical Co., Ltd. (F-5) Potassium acetate: Kishida Chemical Co., Ltd.

<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 which is a flame retardance specification 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 in contact with flame, and flame retardancy was judged from the results according to the following criteria 1.

<Judgment criteria 1 for combustion test results>
○: Combustion duration is 20 seconds or less.
(Triangle | delta): The combustion continuation time exceeds 20 second, and is 40 second or less.
X: Combustion duration exceeding 40 seconds However, Example 4 and Comparative Example 13 which are flame retardants that are inherently highly flame retardant as Intumescent type
For the test piece, the test piece was flame-contacted twice, and the flame retardancy was judged according to the criteria shown below.

<Judgment criteria 2 for combustion test results>
○: Does not ignite at the first flame contact and extinguishes within 40 seconds at the second flame contact △: Does not ignite at the first flame contact and exceeds 40 seconds at the second flame contact Self-extinguishing within 2 minutes ×: Does not ignite at the time of the first flame contact, and continues to burn for more than 2 minutes at the second flame contact, or burns out

Example 1
50 parts by weight of polyethylene resin (“Novatech LL UJ960” manufactured by Nippon Polyethylene Co., Ltd.), 0.5 parts by weight of potassium carbonate (anhydride), 49.5 parts by weight of magnesium hydroxide “Kisuma 5A” (manufactured by Kyowa Chemical Industry Co., Ltd.) And a kneaded mixture at 180 ° C. and 80 rpm 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)
Add 50 parts by weight of magnesium hydroxide “Kisuma 5A” (manufactured by Kyowa Chemical Industry Co., Ltd.) to 50 parts by weight of polyethylene resin (“Novatech LL UJ960” manufactured by Nippon Polyethylene Co., Ltd.) and use a lab plast mill manufactured by Toyo Seiki The mixture was kneaded at 180 ° C. and 80 rpm 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 Examples 2-7)
In Example 1, instead of potassium carbonate (anhydride), a resin composition was prepared in the same manner as in Example 1 except that 0.5 part by weight of the component (F) shown in Table 1 was added. After preparing a test piece from the obtained resin composition, a combustion test was performed. The results are shown in Table 1.

(Example 2)
In Example 1, a resin composition was prepared and obtained in the same manner as in Example 1 except that 50 parts by weight of polypropylene resin (“Novatech PP MA3” manufactured by Nippon Polypro Co., Ltd.) was used instead of polyethylene resin. After preparing a test piece from the resin composition, a combustion test was performed. The results are shown in Table 2.

(Comparative Example 8)
In Comparative Example 1, a resin composition was prepared and obtained in the same manner as in Comparative Example 1 except that 50 parts by weight of polypropylene resin (“Novatec PP MA3” manufactured by Nippon Polypro Co., Ltd.) was used instead of polyethylene resin. After preparing a test piece from the resin composition, a combustion test was performed. The results are shown in Table 2.

(Example 3)
In Example 1, 65 parts by weight of a polyethylene resin, and 34.5 parts by weight of ammonium polyphosphate (trade name “TERRAJU C30” manufactured by Budenheim Co., Ltd.) instead of magnesium hydroxide were used. After preparing a resin composition and preparing a test piece from the obtained resin composition, a combustion test was conducted. The results are shown in Table 3.

(Comparative Example 9)
In Comparative Example 1, a resin composition was prepared in the same manner as in Comparative Example 1 except that 65 parts by weight of the polyethylene resin and 35 parts by weight of ammonium polyphosphate were used instead of magnesium hydroxide. After making a test piece from the above, a combustion test was conducted. The results are shown in Table 3.
(Comparative Examples 10 and 11)
In Example 3, instead of potassium carbonate (anhydride), a resin composition was prepared in the same manner as in Example 3 except that 0.5 part by weight of the component (F) shown in Table 3 was added. After preparing a test piece from the obtained resin composition, a combustion test was performed. The results are shown in Table 3.

Example 4
70 parts by weight of polyethylene resin (“Novatech LL UJ960” manufactured by Nippon Polyethylene Co., Ltd.), 0.5 parts by weight of potassium carbonate (anhydride), 15 parts by weight of ammonium polyphosphate (trade name “TERRAJU C30” manufactured by Budenheim) It was added at a ratio of 14.5 parts by weight of pentaerythritol and kneaded at 180 ° C. and 80 rpm for 4 minutes using a Toyo Seiki Laboplast Mill 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 4.
(Comparative Example 12)
In Example 4, a resin composition was prepared in the same manner as in Example 4 except that 15 parts by weight of pentaerythritol was used without using potassium carbonate, and a test piece was prepared from the obtained resin composition, followed by a combustion test. Was done. The results are shown in Table 4.

Tables 1 to 4 show the composition ratios of the constituent materials and the combustion test results.
In Table 1, in the comparison between Example 1 and Comparative Example 1, it can be seen that the flame retardancy of a polyethylene resin composition containing magnesium hydroxide, which is conventionally known, is remarkably improved by adding a small amount of potassium carbonate. . Moreover, by comparison with Comparative Examples 2-7, it turns out that combined use of potassium carbonate shows a flame retardance improvement effect specifically among carbonates or potassium salts.

In Table 2, it turns out that the same effect as a polyethylene resin composition is acquired also with a polypropylene resin composition.
In Table 3, it can be seen that even with a combination of phosphates and potassium carbonate, the flame retardancy is remarkably improved by the addition of a small amount of potassium carbonate. From Comparative Examples 10 and 11, it can be seen that this effect is unique to potassium carbonate among carbonates.

In Table 4, it can be seen that potassium carbonate has an effect of improving flame retardancy even with a flame retardant called so-called Intumescent, and (D) polyhydric alcohol can be reduced, thereby reducing the production cost. It can be seen that this is preferable.
As is apparent from the above results, flame retardancy is greatly improved by adding potassium carbonate together with metal hydroxides or phosphates to the thermoplastic resin.

  Since the flame retardancy can be improved by blending a small amount of potassium carbonate with a conventionally used flame retardant, the flame retardant resin composition of the present invention is suitable for use in resins for various applications.

Claims (4)

  A flame retardant resin composition comprising (A) a thermoplastic resin, (B) potassium carbonate, and (C) a metal hydroxide or a phosphate.   The flame retardant resin composition according to claim 1, further comprising (D) a polyhydric alcohol.   The flame retardant resin composition according to claim 1, wherein the thermoplastic resin (A) is a polyolefin resin. The difficulty according to any one of claims 1 to 3, wherein (B) potassium carbonate is 0.1 to 20 parts by weight with respect to 100 parts by weight of (A) thermoplastic resin. A flammable resin composition.