JP2005120194A - Flame-retardant polymer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a halogen-free flame-retardant polymer composition in which a flame-retardant inorganic compound containing aluminum and having a small particle size is finely dispersed in the polymer. <P>SOLUTION: The flame-retardant polymer composition comprises an acrylic polymer and the flame-retardant inorganic compound containing aluminum and having a number average particle size of ≤500 nm (such as aluminum hydroxide). A preferred content of the above aluminum-containing flame-retardant inorganic compound is 10-400 pts. by mass based on 100 pts. by mass of the whole polymer containing the above acrylic polymer. The acrylic polymer and the aluminum-containing flame-retardant inorganic compound are preferably incorporated as a composite containing these. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a halogen-free flame retardant polymer composition. More specifically, the present invention relates to a flame retardant polymer composition in which a flame retardant inorganic compound having a small particle size is finely dispersed in a polymer.

  An acrylic polymer using a monomer containing an acrylate ester can be formed into a molded product having excellent heat resistance, oil resistance, and the like, and thus is widely used for oil seals and the like. However, when used at high temperatures, it is required to be flame retardant and not to generate toxic gases such as halogen gas during combustion. Therefore, as a flame retardant, a composition containing a non-halogen compound such as a phosphorus compound, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, antimony compound, etc. (Patent Document 1, Patent Document) 2 etc.) is known.

JP-A-6-340856 Japanese Patent Laid-Open No. 8-59869

When using the above hydroxides or the like as a flame retardant, it is necessary to increase the blending amount in order to obtain sufficient flame retardancy, thereby reducing mechanical properties, particularly tensile strength, and flexibility and workability. There is a problem that decreases. In addition, when the above hydroxide is blended, the fact that micron-sized ones are often used is considered to be a factor that the mechanical properties are not sufficient.
In general, in order to maximize the flame retardancy of a molded article, a composition in which a fine flame retardant having a small size is finely dispersed is considered preferable. According to the technique disclosed in the above-mentioned patent document, there is a problem that even if the polymer component and the flame retardant are blended separately, it is difficult to finely disperse the fine flame retardant.
The present invention provides a flame retardant in which a flame retardant inorganic compound containing an aluminum element and having a small particle size is finely dispersed in a polymer in order to obtain a molded body which is halogen-free and excellent in mechanical properties and flame retardancy. An object of the present invention is to provide a conductive polymer composition.

The present invention is shown below.
1. A flame retardant polymer composition comprising an acrylic polymer and an aluminum-containing flame retardant inorganic compound having a number average particle diameter of 500 nm or less.
2. 2. The flame retardant polymer composition according to 1 above, wherein the acrylic polymer has at least one functional group selected from an alkoxyl group, a hydroxyl group, an amino group, an epoxy group, and a carboxyl group.
3. 3. The flame retardant polymer composition according to 1 or 2, wherein the aluminum-containing flame retardant inorganic compound contains aluminum hydroxide.
4). The flame-retardant property according to any one of 1 to 3 above, wherein the content of the aluminum-containing flame-retardant inorganic compound is 10 to 400 parts by mass with respect to 100 parts by mass of the total polymer including the acrylic polymer. Polymer composition.
5). 5. The flame retardant polymer composition according to any one of 1 to 4, wherein the acrylic polymer and the aluminum-containing flame retardant inorganic compound are contained as a composite containing these.
6). The composite includes a step of mixing an aqueous dispersion of the acrylic polymer with a substance capable of forming the aluminum-containing flame retardant inorganic compound to form a mixed solution, a water-soluble inorganic compound and 6. A flame retardant polymer composition as described in 5 above, which is obtained by a method comprising: a step of co-coagulating an acrylic polymer by adding an acid.
7). The composite includes a step of mixing an aqueous dispersion of the acrylic polymer with the aluminum-containing flame retardant inorganic compound having a number average particle size of 500 nm or less to form a mixed solution, and water-soluble in the mixed solution. 6. A flame retardant polymer composition as described in 5 above, which is obtained by a method comprising a step of co-coagulating an acrylic polymer by adding an inorganic compound and / or an acid.
8). 8. The acrylic polymer according to any one of 1 to 7 above, wherein the acrylic polymer is a polymer comprising a monomer containing a compound selected from (meth) acrylic acid alkyl esters and (meth) acrylic acid alkoxyalkyl esters. Flame retardant polymer composition.
9. The flame retardant according to any one of 1 to 8 above, further comprising a compatibilizer selected from wax, fatty acid ester, fatty acid, fatty acid metal salt, hydrogenated oil, alkylamine, silane coupling agent and titanate coupling agent. Polymer composition.

The flame retardant polymer composition of the present invention is excellent in mechanical properties and flame retardancy by containing an acrylic polymer and an aluminum-containing flame retardant inorganic compound having a number average particle diameter of 500 nm or less. A molded product can be obtained. Moreover, since it is halogen-free, no harmful gas is released by combustion.
When the content of the aluminum-containing flame retardant inorganic compound is 10 to 400 parts by mass with respect to 100 parts by mass of the total polymer including the acrylic polymer, a molded article having more excellent flame retardancy Can be obtained.
When the acrylic polymer and the aluminum-containing flame retardant inorganic compound are obtained by a specific method and contained as a composite containing these, the inorganic compound as a flame retardant is finely dispersed in the polymer. Therefore, it is possible to obtain a molded article having excellent mechanical properties and flame retardancy.

The present invention will be described in detail below.
The flame retardant polymer composition of the present invention is characterized by containing an acrylic polymer and an aluminum-containing flame retardant inorganic compound having a number average particle diameter of 500 nm or less.

  The acrylic polymer is particularly a polymer that uses an acrylic acid ester compound and a methacrylic acid ester compound (hereinafter referred to as “(meth) acrylic acid ester”) as monomers. It is not limited. This polymer may be a homopolymer of each compound or a copolymer. In the case of a copolymer, it may be a copolymer of the above compound and one or more other monomers. The ester may have an alkyl group, may have an aromatic ring, an aliphatic ring or an allyl group, or may have other groups.

Examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, ( Isobutyl acrylate, pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, ( Examples thereof include nonyl methacrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, stearyl (meth) acrylate, and the like.
Examples of the (meth) acrylic acid ester having an aromatic ring include phenyl (meth) acrylate and benzyl (meth) acrylate.
Other examples include cyclohexyl (meth) acrylate.

  Moreover, as said (meth) acrylic acid ester, what has functional groups, such as an alkoxyl group, a hydroxyl group, an amino group, an epoxy group, and a carboxyl group, can also be used, It is preferable to use such a compound. A polymer obtained by using a compound having these functional groups as a monomer can further enhance the dispersibility of the aluminum-containing flame-retardant inorganic compound described below in the composition.

Examples of (meth) acrylic acid ester having an alkoxyl group include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxymethyl (meth) acrylate, and (meth) acrylic acid. Examples include ethoxyethyl, ethoxypropyl (meth) acrylate, butoxyethyl (meth) acrylate, and the like.
Examples of the (meth) acrylic acid ester having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) acrylic acid 5- Examples thereof include hydroxyamyl, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, and the like.

Examples of the (meth) acrylic acid ester having an amino group include 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2- (dimethylaminoethoxy) ethyl (meth) acrylate, and the like. It is done.
Examples of the (meth) acrylic acid ester having an epoxy group include glycidyl (meth) acrylate and epoxidized cyclohexyl (meth) acrylate.
The (meth) acrylic acid esters exemplified above can be used singly or in combination of two or more.

  Other monomers in the case of a copolymer include aromatic vinyl compounds, vinyl cyanide compounds, and further vinyl pyridine, N-vinyl pyrrolidone, vinyl acetate, vinyl propionate, vinyl chloride, vinylidene chloride, Vinyl compounds having functional groups such as epoxy groups, hydroxyl groups, carboxyl groups, amino groups, amide groups, and oxazoline groups other than the exemplified (meth) acrylic acid esters can be used. In addition, polyfunctional vinyl compounds, non-conjugated cyclic polyenes, dihydrodicyclopentadienyloxyethyl group-containing esters of unsaturated carboxylic acids, and the like can also be used.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, ethylstyrene, vinyltoluene, vinylxylene, methyl-α-methylstyrene, t-butylstyrene, 1,1- Chlorinated styrene such as diphenylstyrene, N, N-diethyl-p-aminomethylstyrene, N, N-diethyl-p-aminoethylstyrene, vinylnaphthalene, vinylpyridine, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene And brominated styrene, monofluorostyrene and the like. These compounds can be used alone or in combination of two or more.
Examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile, ethacrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile and the like. These compounds can be used alone or in combination of two or more.

  The above-mentioned “polyfunctional vinyl compound” has two or more vinyl groups in one molecule, and is used for introducing a crosslinking point when a copolymer is used. Examples of the polyfunctional vinyl compound include polyfunctional aromatic vinyl compounds such as divinylbenzene and divinyltoluene, and (meth) acrylic acid of polyhydric alcohols such as (poly) ethylene glycol dimethacrylate and trimethylolpropane triacrylate. Examples include esters, diallyl malate, diallyl fumarate, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, vinyl (meth) acrylate, allyl (meth) acrylate, and the like. These compounds can be used alone or in combination of two or more.

The non-conjugated cyclic polyene and the dihydrodicyclopentadienyloxyethyl group-containing ester of the unsaturated carboxylic acid also have the same action.
Examples of the non-conjugated cyclic polyene include 5-ethylidene-2-norbornene, dicyclopentadiene, 5-propylidene-2-norbornene, 5-vinyl-2-norbornene, 2,5-norbornadiene, 1,4-cyclohexadiene, , 4-cyclooctadiene, 1,5-cyclooctadiene, 5-methylene-2-norbornene, 5-vinyl-2-norbornene, 5- (2-propenyl) -2-norbornene, 5- (3-butenyl) 2-norbornene, 5- (1-methyl-2-propenyl) -2-norbornene, 5- (4-pentenyl) -2-norbornene, 5- (1-methyl-3-butenyl) -2-norbornene, 5 -(5-hexenyl) -2-norbornene, 5- (1-methyl-4-pentenyl) -2-norbornene, 5- (2,3- Methyl-3-butenyl) -2-norbornene, 5- (2-ethyl-3-butenyl) -2-norbornene, 5- (6-heptenyl) -2-norbornene, 5- (3-methyl-5-hexenyl) 2-norbornene, 5- (3,4-dimethyl-4-pentenyl) -2-norbornene, 5- (3-ethyl-4-pentenyl), 5- (7-octenyl) -2-norbornene, 5- ( 2-methyl-6-heptenyl) -2-norbornene, 5- (1,2-dimethyl-5-hexyl) -2-norbornene, 5- (5-ethyl-5-hexenyl) -2-norbornene, 5- ( 1,2,3-trimethyl-4-pentenyl) -2-norbornene and the like. These compounds can be used alone or in combination of two or more.

  Examples of the unsaturated carboxylic acid-containing dihydrodicyclopentadienyloxyethyl group-containing ester include (meth) acrylic acid dihydrodicyclopentadienyl, (meth) acrylic acid dihydrodicyclopentadienyloxyethyl, (meth) ) Dihydrodicyclopentadienyloxyoxydiethyl acrylate and the like. Of these, dihydrodicyclopentadienyloxyethyl acrylate is preferred, and an acrylic polymer using this compound is excellent in processability and excellent in the strength of the resulting molded product. Moreover, these compounds can be used individually by 1 type or in combination of 2 or more types.

  The acrylic polymer may be a resin or an elastomer (including rubber) as long as it is obtained by polymerizing the (meth) acrylic acid ester or the like. The polymerization method for obtaining these is not particularly limited.

  In the present invention, a preferred acrylic polymer is a polymer comprising a monomer containing a compound selected from (meth) acrylic acid alkyl esters and (meth) acrylic acid alkoxyalkyl esters. The total amount of monomer units composed of these compounds is preferably 50 to 100% by mass, more preferably 70 to 98% by mass, based on the total amount of monomer units constituting the polymer. Coalescence is preferred. Specifically, ethyl acrylate / butyl acrylate rubber, methyl acrylate, butyl acrylate rubber, ethyl acrylate / butyl acrylate / methoxy ethyl acrylate rubber, 2-ethylhexyl acrylate / butyl acrylate rubber, 2-ethylhexyl methacrylate・ Butyl acrylate rubber, stearyl acrylate, butyl acrylate rubber, dimethylsiloxane, butyl acrylate rubber, ethyl acrylate, dihydrodicyclopentadienyloxyethyl acrylate rubber, etc. are preferred, especially ethyl acrylate, dihydrodicycloacrylate Pentadienyloxyethyl rubber is preferred.

  Such copolymer rubber can be used for bulk polymerization, solution polymerization, suspension polymerization, emulsification of the above monomers in the presence of radical polymerization initiators such as inorganic or organic peroxides, azo compounds, and redox initiators. It can be obtained by a known method such as polymerization. As the polymerization method, emulsion polymerization is preferred.

  Examples of the emulsifier used in the emulsion polymerization include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. A fluorine-based surfactant can also be used. These emulsifiers can be used alone or in combination of two or more. Usually, anionic surfactants are frequently used, sulfates of higher alcohols, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, aliphatic sulfonates such as sodium lauryl sulfate, capric acid, lauric acid, myristic acid, palmitic acid. Examples thereof include higher aliphatic carboxylates (potassium salt, sodium salt, etc.) such as acid, oleic acid and stearic acid, and rosinate.

As radical polymerization initiators, organic peroxides such as benzoyl peroxide, lauroyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, paramentane hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, etc. Things can be used. Further, diazo compounds such as azobisisobutyronitrile, inorganic peroxides such as potassium persulfate, and redox catalysts obtained by combining these peroxides with ferrous sulfate can also be used. These radical polymerization initiators can be used singly or in combination of two or more.
A chain transfer agent can also be used to adjust the molecular weight of the copolymer rubber. As this chain transfer agent, alkyl mercaptans such as tert-dodecyl mercaptan and n-dodecyl mercaptan, carbon tetrachloride, thioglycols, diterpenes, terpinolene, γ-terpinenes and the like can be used.

In the production process of the acrylic copolymer rubber, monomers, emulsifiers, radical polymerization initiators, chain transfer agents, etc., may start polymerization by charging all of these into a reaction vessel at once, It may be added continuously or intermittently when the reaction is continued. This polymerization can be performed at 0 to 100 ° C. using a reactor from which oxygen is removed, and is preferably performed at a polymerization temperature of 0 to 80 ° C. During the reaction, the production conditions such as temperature or stirring can be appropriately changed. The polymerization method may be a continuous method or a batch method.
The polymerization time is usually about 0.01 to 30 hours, and a latex containing a copolymer rubber is obtained after completion of the polymerization. In order to obtain a solid content, the latex is poured into an aqueous solution of a water-soluble inorganic compound such as sodium chloride or calcium chloride, the copolymer rubber is solidified, washed with water, and dried to obtain the desired copolymer rubber. It is done.

The Mooney viscosity [ML _{1 + 4} (100 ° C.)] of the copolymer rubber obtained as described above is preferably 10 to 200, more preferably 20 to 100.

  Next, the aluminum containing flame retardant inorganic compound contained with the acrylic polymer in the flame retardant polymer composition of the present invention will be described. The said aluminum containing flame-retardant inorganic compound is used as a flame retardant, and if it is a compound containing an aluminum element and a number average particle diameter is 500 nm or less, it will not specifically limit. The number average particle diameter is preferably 1 to 500 nm, more preferably 5 to 300 nm, and still more preferably 5 to 200 nm. When this number average particle diameter is too large, the flame retardancy and strength of the resulting molded product tend to decrease.

Examples of the aluminum-containing flame retardant inorganic compound include aluminum hydroxide, aluminum sulfate, and aluminum silicate. Of these, aluminum hydroxide containing crystal water and having the property of starting dehydration decomposition at about 200 ° C. is particularly preferable. In the present invention, the “aluminum hydroxide” is not only represented by Al (OH) ₃ , but also alumina hydrate (Al ₂ O ₃ .H ₂ O, Al ₂ O ₃ .3H ₂ O, etc.) Shall also be included.
Moreover, the said inorganic compound can be used individually by 1 type or in combination of 2 or more types.

  The content of the aluminum-containing flame-retardant inorganic compound contained in the flame-retardant polymer composition of the present invention is preferably 10 to 10 parts by mass when the total of the polymers including the acrylic polymer is 100 parts by mass. 400 parts by mass, more preferably 20 to 200 parts by mass. If the content of the aluminum-containing flame retardant inorganic compound is too small, the resulting molded article tends to be inferior in flame retardancy, while if it is too much, the mechanical strength of the molded article tends to decrease.

The flame retardant polymer composition of the present invention contains an acrylic polymer and an aluminum-containing flame retardant inorganic compound having a number average particle diameter of 500 nm or less, and these components are blended separately. It is difficult to finely disperse an aluminum-containing flame-retardant inorganic compound having a number average particle diameter of 500 nm or less, preferably aluminum hydroxide. The present inventors prepare a composite containing the acrylic polymer and the aluminum-containing flame retardant inorganic compound, and use this to form a flame retardant polymer composition. It was possible to obtain a molded body that was finely dispersed in the coalesced and halogen-free and excellent in flame retardancy.
Examples of the method for preparing the complex include the following methods.
(1) A step of mixing an aqueous dispersion of an acrylic polymer with a substance capable of forming an aluminum-containing flame-retardant inorganic compound (hereinafter also referred to as “inorganic compound-forming substance”) to obtain a mixed liquid (p1). And a step (p2) of adding a water-soluble inorganic compound and / or acid to the mixed solution to co-solidify the acrylic polymer.
(2) A step (q1) of mixing an aqueous dispersion of an acrylic polymer with an aluminum-containing flame-retardant inorganic compound having a number average particle size of 500 nm or less to form a mixed solution, and a water-soluble inorganic in the mixed solution. And a step (q2) of adding a compound and / or an acid to co-solidify the acrylic polymer.

In the method (1), the “aqueous dispersion of acrylic polymer” is a dispersion of the acrylic polymer exemplified above in an aqueous medium. The dispersion medium is usually water, but may be an aqueous medium in which alcohol or the like dissolves in water. The method for dispersing the acrylic polymer exemplified above is not particularly limited.
As the dispersion, a latex obtained by emulsion polymerization is preferable, and as described above, a latex obtained by producing an acrylic copolymer rubber by emulsion polymerization can be used as it is. The above-mentioned acrylic polymer aqueous dispersions may be used alone or in combination of two or more, regardless of the type of acrylic polymer or the type of aqueous dispersion.

  On the other hand, the substance capable of forming an aluminum-containing flame-retardant inorganic compound (inorganic compound-forming substance) is preferably a substance capable of forming aluminum hydroxide or the like. In mixing with the acrylic polymer aqueous dispersion, the inorganic compound-forming substance may be in a solid state, a solution dissolved in a medium, or a dispersion dispersed in a medium. May be.

The substance capable of forming aluminum hydroxide may be either an inorganic substance or an organic substance. As this inorganic substance, (i) sulfate containing aluminum element, sulfite, hyposulfite, nitrate, nitrite, hyponitrite, chlorate, chlorite, hypochlorite, bromate Metal salts such as bromite, hypobromite, phosphate, phosphite, hypophosphite, hydrochloride (chloride, polychloride), (ii) sodium aluminate, etc. Examples include aluminates. These compounds can be used alone or in combination of two or more.
These compounds can be used in the form dissolved or dispersed in water, acid, alkali or the like.

As the organic substance, an organometallic compound containing aluminum element, an organic acid salt, or the like can be used. The organometallic compound is preferably a metal alkoxide containing an aluminum element, and examples include triethoxyaluminum, tripropoxyaluminum, or a compound in which at least one of them is substituted with a hydrolyzable halogen such as chlorine. These compounds can be used alone or in combination of two or more.
These organometallic compounds are usually used in a state dissolved in an organic solvent exemplified by water-soluble alcohols such as ethanol, methanol, and isopropyl alcohol. Accordingly, by adding water to the organometallic compound solution, the organometallic compound is hydrolyzed, and then the hydrolyzate is condensed to obtain a solution containing the inorganic compound forming substance. In the reaction between the organometallic compound and water, an acidic substance or an alkaline substance may be added as necessary in order to accelerate the condensation reaction. These can also be added as an acid or alkali aqueous solution.
Examples of the organic acid salt include acetate, succinate, phthalate, and hexanoate. These compounds can be used alone or in combination of two or more.

The organic substance obtained as described above, or a solution or dispersion containing this organic substance can be used by mixing with a solution or dispersion containing the inorganic substance. At the time of use, you may adjust pH etc. as needed.
Of the above compounds, those that do not dissolve in a medium such as water, acid, alkali, etc. can be used in a state dispersed in these media. In that case, a colloid mill, a homogenizer, or the like can be used.

In the step (p1) of the method (1), the method for mixing the aqueous dispersion of the acrylic polymer and the inorganic compound-forming substance is not particularly limited. The content of the substance is preferably 10 to 400 parts by mass, more preferably 10 to 400 parts by mass, with respect to 100 parts by mass of the acrylic polymer, the amount of inorganic compound to be formed (mainly aluminum hydroxide). It selects so that it may become 20-200 mass parts. In the case of using the inorganic compound-forming substance as a composite containing aluminum hydroxide, a by-product may be contained, so that the use amount may be selected in consideration thereof.
In addition to the aqueous dispersion of the acrylic polymer and the inorganic compound-forming substance, aluminum hydroxide particles or a dispersion thereof may be further used in the mixed liquid stage. In this case, the usage amount of the aqueous dispersion of the acrylic polymer and the inorganic compound-forming substance may be selected in the same manner as described above.
In addition, the mixing method in the said process (p1) is not specifically limited.

  Subsequently, in order to produce | generate a composite_body | complex as a solidified material from the said liquid mixture, it progresses to a process (p2). In this step (p2), a water-soluble inorganic compound and / or an acid is added to the mixed solution to co-coagulate the acrylic polymer, and a coagulated product is applied by applying a method of coagulating a rubber component from a normal latex. Can be formed.

The water-soluble inorganic compound used for co-coagulation is preferably an electrolyte, and examples thereof include (i) sodium chloride, potassium chloride, (ii) salts of polyvalent metals such as calcium, magnesium, zinc, and aluminum. Examples of the latter (ii) include calcium chloride, magnesium chloride, zinc chloride, aluminum chloride, calcium nitrate, magnesium nitrate, zinc nitrate, aluminum nitrate, magnesium sulfate, zinc sulfate, and aluminum sulfate. The compounds exemplified above can be used singly or in combination of two or more. Moreover, these compounds may be used in a solid state or as an aqueous solution.
Examples of acids that can be used for co-coagulation include hydrochloric acid, nitric acid, sulfuric acid, and the like.

  The temperature at the time of co-coagulation in the step (p2), the pH of the mixed solution, etc. are not particularly limited, but in order to reduce inorganic salts remaining in the produced composite, the temperature is 10 ° C. or higher, preferably 10 It is preferable that the temperature is set to -80 ° C, more preferably 10 to 50 ° C, and the mixed solution is controlled within the range of pH 4 to 11, preferably pH 5 to 10. If the temperature during co-solidification is less than 10 ° C., it tends to be industrially unsuitable. On the other hand, if the temperature is too high, the dispersion of the aluminum-containing flame-retardant inorganic compound tends to deteriorate.

After co-coagulation, the electrolyte is usually removed by washing the coagulated product with water, etc., and then moisture is removed by hot air drying, vacuum drying, etc., and drying is performed. From the above, a composite is obtained in which an inorganic compound mainly composed of aluminum hydroxide is uniformly finely dispersed in an acrylic polymer.
The number average particle diameter of the aluminum-containing flame retardant inorganic compound contained in the composite produced by the above method (1) is preferably 1 to 500 nm, more preferably 5 to 300 nm.
Moreover, the number average particle diameter of the composite_body | complex manufactured by the said method (1) is 10 micrometers-20 mm normally, Preferably it is 100 micrometers-10 mm.

Next, the method (2) will be described. As the aqueous dispersion of the acrylic polymer used in the step (q1), the one described in the step (p1) of the method (1) can be applied as it is.
In addition, when using an aluminum-containing flame retardant inorganic compound having a number average particle size of 500 nm or less, for example, aluminum hydroxide, it may be in a solid state or a solution dissolved in a medium, A dispersion dispersed in a medium may be used.

In the step (q1) of the method (2), a method of mixing the aqueous dispersion of the acrylic polymer and the aluminum-containing flame retardant inorganic compound is not particularly limited. The content of the aluminum-containing flame retardant inorganic compound is selected so as to be preferably 10 to 400 parts by mass, more preferably 20 to 200 parts by mass with respect to 100 parts by mass of the acrylic polymer.
In addition, the mixing method in the said process (q1) is not specifically limited, either. However, in order to obtain a more finely dispersed composite, it is preferable to sufficiently stir the mixed solution.

Subsequently, in order to produce | generate a composite_body | complex as a solidified material from the said liquid mixture, it progresses to a process (q2). In this step (q2), a water-soluble inorganic compound and / or acid is added to the mixed solution to co-solidify the acrylic polymer, and the method described in the step (p2) of the method (1) is applied. can do.
The number average particle diameter of the aluminum-containing flame retardant inorganic compound contained in the composite produced by the above method (2) is preferably 1 to 500 nm, more preferably 5 to 300 nm.
Moreover, the number average particle diameter of the composite_body | complex manufactured by the said method (2) is 10 micrometers-20 mm normally, Preferably it is 100 micrometers-10 mm.

  The flame retardant polymer composition of the present invention can be obtained by kneading the composite as it is. In addition, the flame retardant polymer composition of the present invention is kneaded by appropriately combining the composite and a component selected from an acrylic polymer, another polymer, various additives and the like constituting the composite. Can also be obtained.

  Other polymers include ethylene / propylene rubber, ethylene / acrylic rubber, polyethylene, polypropylene, polyamide, polyester, polysulfone, polyethersulfone, polyphenylene sulfide, liquid crystal polymer, polyvinylidene fluoride, styrene / vinylidene acetate copolymer, Examples include acrylonitrile / styrene copolymer and methyl methacrylate / styrene copolymer. These can be used alone or in combination of two or more.

  The amount of the other polymer used is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass with respect to 100 parts by mass of the acrylic polymer.

  Examples of the additives include compatibilizers, antioxidants, anti-aging agents, ultraviolet absorbers, heat stabilizers, plasticizers, lubricants, antibacterial agents, fillers, other flame retardants, weathering agents, colorants (pigments, Dyes) and the like.

  Examples of the compatibilizer include wax, fatty acid ester, fatty acid, fatty acid metal salt, hydrogenated oil, alkylamine, silane coupling agent, titanate coupling agent and the like. These can be used alone or in combination of two or more. The blending amount in the case of using this compatibilizer is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass with respect to a total of 100 parts by mass of the polymer including the acrylic polymer. It is.

  Examples of the antioxidant include hindered amines, hydroquinones, hindered phenols, and sulfur-containing compounds. These can be used alone or in combination of two or more.

  The anti-aging agent includes naphthylamine, diphenylamine, p-phenylenediamine, quinoline, hydroquinone derivatives, monophenol, bis-, tris-, polyphenol, thiobisphenol, hindered phenol, phosphorous acid. Examples include ester compounds. These can be used alone or in combination of two or more.

  Examples of the ultraviolet absorber include benzophenones, benzotriazoles, salicylic acid esters, metal complex salts and the like. These can be used alone or in combination of two or more.

  Examples of the heat stabilizer include aliphatic carboxylates such as salts of sodium, calcium, aluminum, barium, magnesium, manganese, iron, zinc, lead, silver, copper and the like such as lactic acid and hydroxybutyric acid. These can be used alone or in combination of two or more.

  Examples of the plasticizer include aliphatic dibasic acid esters, phthalic acid esters, hydroxy polyvalent carboxylic acid esters, polyester plasticizers, fatty acid esters, and epoxy plasticizers. These can be used alone or in combination of two or more.

  Examples of the lubricant include fatty acid ester, hydrocarbon resin, paraffin, higher fatty acid, oxy fatty acid, fatty acid amide, alkylene bis fatty acid amide, aliphatic ketone, fatty acid lower alcohol ester, fatty acid polyhydric alcohol ester, fatty acid polyglycol ester, aliphatic Examples include alcohol, polyhydric alcohol, polyglycol, polyglycerol, metal soap, and modified silicone. These can be used alone or in combination of two or more.

  As the antibacterial agent, zeolite antibacterial agent, silica gel antibacterial agent, glass antibacterial agent, calcium phosphate antibacterial agent, zirconium phosphate antibacterial agent, silicate antibacterial agent, titanium oxide antibacterial agent, ceramic antibacterial agent , Inorganic antibacterial agents such as whisker antibacterial agents, and formaldehyde releasing agents, halogenated aromatic compounds, rhodopropargyl derivatives, thiocyanato compounds, isothiazolinone derivatives, trihalomethylthio compounds, quaternary ammonium salts, biguanide compounds, aldehydes, phenols Organic antibacterial agents such as benzimidazole derivatives, pyridine oxides, carbanilides, diphenyl ethers, carboxylic acids and organometallic compounds, and natural antibacterial agents can be used.

  The filler may be any of an organic filler, an inorganic filler, and an organic-inorganic composite filler. Glass fiber, carbon fiber, glass bead, carbon black, talc, wollastonite, rock filler, mica, glass flake, Examples include milled fiber, molybdenum disulfide, zinc oxide whisker, and calcium titanate whisker. These can be used alone or in combination of two or more.

  The flame retardant polymer composition of the present invention can be obtained by kneading each component using various extruders, Banbury mixers, kneaders, rolls and the like. When kneading, each component may be kneaded in a lump or may be kneaded by a multistage addition method. Using the composition thus obtained, a molded product having a predetermined shape can be produced by injection molding, extrusion molding, hollow molding, compression molding, sheet extrusion, vacuum molding, foam molding, blow molding or the like. .

  Hereinafter, the present invention will be specifically described with reference to examples. In addition, this invention is not restrict | limited at all by these Examples. Further, “%” and “part” in the examples are based on mass unless otherwise specified.

1. Production of complex 1-1. Preparation of Acrylic Polymer A nitrogen-substituted stainless steel container was charged with 95 parts of ethyl acrylate, 5 parts of dihydrodicyclopentadienyloxyethyl acrylate (DCPOEA), 4 parts of sodium lauryl sulfate, and 200 parts of water. Thereafter, 0.2 part of potassium persulfate was added as a polymerization initiator, and polymerization was started at 50 ° C. When the polymerization conversion reached almost 100%, 0.5 part of N, N-diethylhydroxylamine was added to stop the copolymerization reaction, and latex (A) having a solid content concentration of 21% was obtained. The reaction time was 15 hours.
Next, 1900 parts of a 0.25% aqueous solution of calcium chloride was added to 476 parts of the latex (A) to coagulate the polymer, and the coagulated product was thoroughly washed with water. Thereafter, the obtained solidified product was decanted and dried at about 90 ° C. for 3 hours to obtain a powdery acrylic polymer (ACM-1). The Mooney viscosity ML _{1 + 4} (100 ° C.) of this polymer (ACM-1) was 50 (see Table 1).

1-2. Preparation of composite and preparation and evaluation of composition Example 1
Add 760 parts of 10% sulfuric acid to 5140 parts of 2.4% sodium aluminate aqueous solution (0.9% in terms of Al ₂ O ₃ ), adjust the mixture to pH 7, and contain aluminum hydroxide as the main component. An aluminum-containing slurry solution was obtained. Thereafter, 476 parts of the 21% latex (A) prepared above (100 parts as a solid rubber) was added to the aluminum-containing slurry solution, and mixed using a stirrer to produce a crumb slurry. The crumb slurry was pH 7.5.
Next, the mixed solution is adjusted to pH 7 using 10% sulfuric acid to complete coagulation, and crumb composed of an acrylic polymer having an average diameter of about 0.3 mm and an inorganic compound is produced by co-coagulation. It could be confirmed. All crumbs settled and the supernatant of the liquid was clear.
The obtained crumb was washed with water and then dried at 90 ° C. using a hot air dryer to obtain a composite (I). It was 20 nm when the number average particle diameter of the inorganic compound which comprises this composite_body | complex (I) was measured with the transmission electron microscope (type "H-7500" Hitachi Ltd. make). In addition, the composite (I) is ashed, and from the content of the inorganic compound calculated from the ash and the measurement result of the X-ray microanalyzer (XMA), the composite (I) is converted into the acrylic polymer (ACM- 1) It turned out that 60 parts of aluminum hydroxide and 20 parts of aluminum sulfate are included with respect to 100 parts (refer Table 1).

  180 parts of the composite (I), 10 parts of FEF carbon black (trade name “SEAST SO” manufactured by Tokai Carbon Co., Ltd.), 5 parts of zinc white (trade name “Zinc Oxide” manufactured by Shodo Chemical Industry Co., Ltd.), stearic acid 1 part of Kao (trade name “Lunac S-30”) and 5 parts of silane coupling agent (bis (triethoxysilylpropyl) tetrasulfane, Degussa, trade name “Si69”) (Made by Kobe Steel) Thereafter, the kneaded product was cooled, and further 4 parts of dicumyl peroxide (manufactured by NOF Corporation, trade name “Park Mill D-40”) as a crosslinking agent, and trimethylolpropane trimethacrylate (Seiko Chemical Co., Ltd.) as a crosslinking aid. Made by a 10-inch open roll, made into a molded body using a sheet mold (150 mm × 150 mm × 2 mm), and heated at 170 ° C. by a press molding machine It was press-crosslinked for 20 minutes to obtain a rubber sheet having a thickness of 2 mm.

The rubber sheet was processed and evaluated according to the following items. The results are shown in Table 2.
(1) Tensile breaking strength and tensile breaking elongation Measured according to JIS-K6251.
(2) Hardness As a flexibility index, the hardness was measured according to JIS-K6253.
(3) Flame retardance The oxygen index (LOI) was measured according to JIS-K6269. The unit is%. This oxygen index is the minimum oxygen concentration in the atmosphere required for continuous combustion, i.e., the minimum oxygen concentration expressed as the volume percentage in oxygen necessary for the material to continue to burn under the prescribed test conditions. The larger the value, the better the flame retardancy.
(4) Weather resistance Based on JIS-K6259, the presence or absence of cracks was examined under the conditions of ozone concentration of 500 pphm, 40 ° C., 200 hours, and static 40% elongation. The case where no crack was observed was designated as “NC”.
(5) Oil resistance Based on JIS-K6258, IRM903 test oil (No. 3 oil) was used and the volume change rate ((DELTA) V) by a 100-hour 70 degree immersion test was calculated | required.

Example 2
680 parts of 10% sulfuric acid was added to 5140 parts of 2.4% sodium aluminate aqueous solution, and the mixed solution was adjusted to pH 9 to obtain an aluminum-containing slurry solution containing aluminum hydroxide as a main component. Thereafter, 476 parts of the 21% latex (A) prepared above was added to the aluminum-containing slurry solution and mixed using a stirrer to produce a crumb slurry. The crumb slurry was pH 9.5.
Next, the mixed solution is adjusted to pH 7 by adding 10% sulfuric acid to complete coagulation, and crumb made of an acrylic polymer and an inorganic compound having an average diameter of about 0.4 mm is formed by co-coagulation. Was confirmed. All crumbs settled and the supernatant of the liquid was clear.
The obtained crumb was washed with water and then dried at 90 ° C. using a hot air dryer to obtain a composite (II). This composite (II) was found to contain 68 parts of aluminum hydroxide and 12 parts of aluminum sulfate with respect to 100 parts of the acrylic polymer (ACM-1) (see Table 1).
Each evaluation was performed in the same manner as in Example 1 using the complex (II). The results are also shown in Table 2.

Example 3
840 parts of 10% sulfuric acid was added to 5140 parts of 2.4% sodium aluminate aqueous solution, and the mixture was adjusted to pH 4 to obtain an aluminum-containing slurry solution containing aluminum hydroxide as a main component. Thereafter, 476 parts of the 21% latex (A) prepared above was added to the aluminum-containing slurry solution and mixed using a stirrer to produce a crumb slurry. The crumb slurry was pH 4.5. As a result, it was confirmed that crumbs composed of an acrylic polymer having an average diameter of about 0.3 mm and an inorganic compound were produced by co-solidification. All crumbs settled and the supernatant of the liquid was clear.
The obtained crumb was washed with water and then dried at 90 ° C. using a hot air dryer to obtain a composite (III). This composite (III) was found to contain 48 parts of aluminum hydroxide and 32 parts of aluminum sulfate with respect to 100 parts of the acrylic polymer (ACM-1) (see Table 1).
Each evaluation was performed in the same manner as in Example 1 using the complex (III). The results are also shown in Table 2.

Comparative Example 1
100 parts of the above acrylic polymer (ACM-1), 80 parts of aluminum hydroxide powder (trade name “Hijilite H-42M”), 10 parts of the FEF carbon black, 5 parts of the zinc white, 1 part of the stearic acid, and Each evaluation was performed in the same manner as in Example 1 except that 5 parts of the silane coupling agent was kneaded with a Banbury mixer (manufactured by Kobe Steel). The results are also shown in Table 2.

Comparative Example 2
Each evaluation was performed in the same manner as in Example 1 except that magnesium hydroxide powder (trade name “Kisuma 5B”, manufactured by Kyowa Chemical Co., Ltd., average particle size 0.8 μm) was used instead of the aluminum hydroxide powder. It was. The results are also shown in Table 2.

2. About Evaluation Results From Table 2, Comparative Examples 1 and 2 are examples containing a flame retardant having a large particle size, and although the oil resistance exceeds 18%, the tensile strength is inferior to 3.4 MPa and 3.2 MPa, respectively. . Moreover, the flame retardance was as low as 27% and 28%.
On the other hand, Examples 1-3 showed tensile strength and flame retardance superior to those of Comparative Example 1 in all cases, although the content of aluminum hydroxide contained in each composite did not reach 80 parts. It was. These examples appear to exhibit excellent properties due to the fine dispersion of inorganic compounds as flame retardants.

The flame-retardant polymer composition of the present invention has oil resistance and heat resistance, and can be formed into a molded body excellent in fuel oil resistance and tensile strength. Taking advantage of this effect, an oil cooler hose and an air duct hose , Power steering hoses, control hoses, intercooler hoses, torque converter hoses, oil return hoses, heat-resistant hoses and other hose materials, fuel hose materials, bearing seals, bulk stem seals, various oil seals, O-rings, packing, gaskets, etc. It can be suitably used for sealing materials, various diaphragms, rubber plates, belts, oil level gauges, hose masking, pipe insulating materials and other coating materials, and rolls for copying machines.

Claims (9)

  A flame retardant polymer composition comprising an acrylic polymer and an aluminum-containing flame retardant inorganic compound having a number average particle diameter of 500 nm or less.   The flame-retardant polymer composition according to claim 1, wherein the acrylic polymer has at least one functional group selected from an alkoxyl group, a hydroxyl group, an amino group, an epoxy group, and a carboxyl group.   The flame-retardant polymer composition according to claim 1 or 2, wherein the aluminum-containing flame-retardant inorganic compound contains aluminum hydroxide.   The flame retardant according to any one of claims 1 to 3, wherein the content of the aluminum-containing flame retardant inorganic compound is 10 to 400 parts by mass with respect to 100 parts by mass of the total polymer including the acrylic polymer. Polymer composition.   The flame-retardant polymer composition according to any one of claims 1 to 4, wherein the acrylic polymer and the aluminum-containing flame-retardant inorganic compound are contained as a composite containing them.   The composite includes a step of mixing an aqueous dispersion of the acrylic polymer with a substance capable of forming the aluminum-containing flame retardant inorganic compound to form a mixed solution, a water-soluble inorganic compound and 6. A flame retardant polymer composition according to claim 5, which is obtained by a method comprising: a step of co-coagulating an acrylic polymer by adding an acid.   The composite includes a step of mixing an aqueous dispersion of the acrylic polymer with the aluminum-containing flame retardant inorganic compound having a number average particle size of 500 nm or less to form a mixed solution, and water-soluble in the mixed solution. The flame retardant polymer composition according to claim 5, which is obtained by a method comprising: adding an inorganic compound and / or an acid to co-coagulate the acrylic polymer.   The said acrylic polymer is a polymer formed by using a monomer containing a compound selected from (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. Flame retardant polymer composition. The flame retardant according to any one of claims 1 to 8, further comprising a compatibilizing agent selected from wax, fatty acid ester, fatty acid, fatty acid metal salt, hydrogenated oil, alkylamine, silane coupling agent and titanate coupling agent. Polymer composition.