JP3008459B2 - Polyamide resin composition - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a blooming-free flame retardant polyamide composition containing a flame retardant and a modified polyester elastomer.

The composition has excellent moldability and impact properties, particularly excellent tensile properties, and can be widely and generally used for the production of automobile parts, electric parts, machine parts, and other various molded articles.

(Prior Art) Conventionally, polyamide resins have been widely used in general household goods such as electronic parts and automobile parts because they have excellent properties such as being relatively inexpensive and being easily molded. However, polyamide resins are flammable and burn easily once a fire occurs. Therefore, particularly a cable fire has a great effect on society.

Therefore, recently, in some of the fields of use of these resins, such as electric products, automobile interior products, and textile products, flame retardation is required by law. For example, the flame retardant regulation of MVSS-302 in the automotive industry in the United States is known.

Generally, in order to impart flame retardancy to a polyamide resin,
A flame retardant is added at the time of kneading of the resin, and as the flame retardant, an inorganic compound, an organic phosphorus compound, and the like are known, but in order to exert the flame retardant effect, the compounding amount must be increased. In addition, there are disadvantages in that the physical properties of the resin are deteriorated due to poor dispersion, and that the so-called blooming phenomenon is liable to occur, in which the compounded flame retardant precipitates in a powder form on the resin surface after molding.

It is also known to produce a flame-retardant rubber-reinforced polyamide resin by adding a flame retardant to a rubber-reinforced polyamide resin. The polyamide resin has a disadvantage that the excellent properties inherent in the rubber-reinforced polyamide resin before adding the flame retardant, that is, the tensile strength and elongation properties and the impact properties are reduced by adding the flame retardant. Was.

(Problems to be Solved by the Invention) The present invention provides a flame-retardant polyamide composition having excellent tensile strength and elongation properties and impact properties, which cannot be solved by the methods known in the prior art, and without blooming. It is something to offer.

(Means for Solving the Problems) In order to solve the above problems, the present inventors have aimed at obtaining a composition which is excellent in physical properties such as impact characteristics and heat resistance and does not cause blooming. As a result of diligent research efforts, the present invention has finally been completed. That is, the present invention relates to a modified polyester elastomer obtained by reacting a polyester elastomer with (A) a polyamide resin, (B) a monomer selected from unsaturated carboxylic acids and unsaturated carboxylic acid derivatives, and (C) an organic resin. Halogen compounds, nitrogen-containing compounds and the following general formulas (I) to
The above object is achieved by a polyamide composition containing at least one flame retardant selected from the phosphorus compounds represented by (III).

(Wherein, R ₁ , R ₂ and R ₃ each represent the same or different alkyl, haloalkyl, aryl and haloaryl groups.) The polyamide resin (A) contained in the composition of the present invention includes nylon 6, Nylon 6,6, Nylon 6,9, Nylon 6,10, Nylon 6,12, Nylon 6 / 6,6, Nylon 4,
6. Polyxylylene adipamide, polyhexamethylene terephthalamide, polyphenylene phthalamide, polyxylylene adipamide, polyxylene adipamide / hexamethylene adipamide, polyester amide elastomer, polyether amide elastomer, dimer acid Copolyamide and the like are exemplified. These can be used alone or as a mixture, or a copolymer obtained by using a monomer forming these resins is also used. The melting point of the polyamide resin is preferably 170 ° C. or higher from the viewpoint of heat resistance. Usually, polyamide resin has relative viscosity (JIS K6
(Measured in 90% sulfuric acid according to 810-1970) is preferably 1.8 or more, more preferably 2.0 or more.

Examples of the polyester elastomer used for preparing the modified polyester elastomer contained in the composition of the present invention include a polyester-polyether block copolymer and a polyester-type block copolymer.

The polyester-polyether block copolymer is a block copolymer having the property of a rubber-like elastic body because polyester is a hard segment and polyether is a soft segment, and both are alternately and repeatedly arranged.

The acid and alcohol constituting such a polyester unit are mainly an aromatic dicarboxylic acid and an alkylene glycol having 2 to 15 carbon atoms, respectively. Specific examples of dicarboxylic acids include terephthalic acid, isophthalic acid, ethylenebis (p-oxybenzoic acid), naphthalenedicarboxylic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, and p- (β-hydroxyethoxy). Benzoic acid and the like. Specific examples of glycols include ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediethanol, benzenedimethanol, and benzene. Diethanol and the like. As the above dicarboxylic acid and glycol, the melting point of a polyester having a molecular weight of a fiber forming ability,
Those that are 200 ° C or higher are suitable.

The polyether unit which is a soft segment of the block copolymer is a polyoxyalkylene glycol having an average molecular weight of about 500 to 5,000. This polyoxyalkylene glycol unit has an oxyalkylene group having an alkylene group having 2 to 9 carbon atoms as a monomer unit. Specifically, poly (oxyethylene) glycol,
Preferable examples include poly (oxypropylene) glycol and poly (oxytetramethylene) glycol. The polyether may be a homopolymer, a random copolymer, a block copolymer, or a mixture of two or more polyethers. Further, the polyether may have a small amount of an aliphatic group, an aromatic group, or the like in the molecular chain. Also,
Modified polyethers containing sulfur, nitrogen, phosphorus and the like may be used.

Polyester-polyether block copolymer,
Polyether units are contained in a proportion of 1 to 85% by weight, preferably 5 to 80% by weight, and polyester units in a proportion of 99 to 15% by weight, preferably 95 to 20% by weight.

Examples of the polyester-type block copolymer include those obtained by reacting a crystalline aromatic polyester with a lactone. Examples of the crystalline aromatic polyester include a polymer mainly having an ester bond or an ester bond and an ether bond, having at least one aromatic group as a main repeating unit and having a hydroxyl group at a molecular terminal. . The crystalline aromatic polyester preferably has a melting point of 150 ° C. or higher when a polymer having a high degree of polymerization is formed. When using the polyamide resin composition of the present invention as a molding material,
Polymers having a molecular weight of 5000 or more are preferred, but when used in adhesives and coating agents, polymers having a molecular weight of 5000 or less may be used. Preferred specific examples of the crystalline aromatic polyester are
It can be found in homopolyesters, polyester ethers, copolymerized polyesters, copolymerized polyester ethers and the like. Examples of the homopolyester include polyethylene terephthalate, polytetramethylene terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate, and polyethylene-2,6-naphthalate. Examples of polyester ethers include polyethylene oxybenzoate, poly-p-phenylene bisoxyethoxy terephthalate, and the like. Examples of the copolyester or copolyesterether include polymers mainly having a tetramethylene terephthalate unit or an ethylene terephthalate unit and further having another copolymerization component. Examples of such a copolymer component include a tetramethylene terephthalate unit, an ethylene isophthalate unit, a tetramethylene adipate unit, an ethylene adipate unit, a tetramethylene sebacate unit, an ethylene sebacate unit, a 1,4-cyclohexylene dimethylene terephthalate unit, Tetramethylene-p-
Examples thereof include an oxybenzoate unit and an ethylene-p-oxybenzoate unit. The copolymerized polyester and the copolymerized polyester ether contain 60 mol% of tetramethylene terephthalate unit or ethylene terephthalate unit.
It is preferable to include the above.

As the other lactone constituting the polyester type block copolymer, ε-caprolactone is most preferred, but enantholactone, caprylolactone and the like are also used. Two or more of these lactones may be used.

The polyester type block copolymer is obtained by copolymerizing the above-mentioned crystalline aromatic polyester and lactones in a weight ratio of 97/3 to 5/95. Preferably, the weight ratio is 95/5 to 30/70. At the time of the above copolymerization, a catalyst is added if necessary, and the mixture is heated and mixed to progress the reaction. The polyester elastomer (polyester-polyether block copolymer and / or polyester type block copolymer) thus obtained is used alone,
Alternatively, two or more kinds may be used in combination.

The modifier which is reacted with the polyester elastomer to obtain the modified polyester elastomer is selected from unsaturated carboxylic acids and derivatives thereof. As unsaturated carboxylic acids, acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endo-bicyclo (2,2,1) Hept-5-ene-2,3
-Dicarboxylic acid (nadic acid), methyl-endosis-
Bicyclo (2,2,1) hept-5-ene-2,3-dicarboxylic acid (methylnadic acid) can be exemplified. Examples of the derivative of the unsaturated carboxylic acid include derivatives of the above acids such as acid halides, amides, imides, acid anhydrides and esters. Specific examples include maleenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like. Among these, unsaturated dicarboxylic acids or unsaturated dicarboxylic anhydrides are preferably used. Particularly, maleic acid, nadic acid, or acid anhydrides thereof are preferred.

These modifiers are used in an amount of about 0.01 to about 20% by weight, preferably about 0.02 to about 20% by weight, based on the polyester elastomer.
Used in the range. If it is less than 0.01% by weight, the effect of improving the physical properties of the polyamide resin composition is small. If it exceeds 20% by weight, gelation tends to occur during the graft reaction.

The method of reacting (grafting and copolymerizing) the modifier with the polyester elastomer is not particularly limited, but it is desirable that an undesired component such as gel is not contained in the resulting modified polyester elastomer.
Further, when the fluidity is reduced, the processability is deteriorated, which is not desirable. Specifically, for example, a graft reaction occurs by blending the above-mentioned polyester elastomer, a modifier, and a radical generator and melt-kneading, thereby obtaining a modified polyester elastomer. As the radical generator, known organic peroxides or diazo compounds can be used. Specifically, benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-
Butyl cumyl peroxide, cumene hydroperoxide, azobisisobutyronitrile and the like can be exemplified. The amount of the radical generator used is 0.05% by weight or more, preferably 0.1 to
1.5% by weight.

In the polyamide resin composition of the present invention, the weight ratio (A) / (B) between the polyamide resin (A) and the modified polyester elastomer (B) is preferably from 95/5 to 5/95, Preferably, (A) / (B) is 90/10 to 10/90. The weight ratio of the modified polyester elastomer is
If it is smaller than 95/5, impact resistance, rigidity, etc. are not improved. When the weight ratio of the modified polyester elastomer is more than 5/95, the water resistance and the like are reduced.

Next, the flame retardant (C) blended in the present invention is preferably a compound having excellent heat resistance in consideration of the heat history received during the molding process of the polyamide composition. A compound selected from the group consisting of a compound and a phosphorus compound represented by the aforementioned general formulas (I) to (III).
Although more than one kind of flame retardant is employed, an organic halogen compound is particularly preferred in the present invention.

The organic halogen compound generally refers to a compound that is treated as a halogen-based flame retardant, and is preferably an aromatic halogen compound having excellent heat resistance in consideration of the heat history of the polyamide composition during molding.

Specific examples include halogenated polycarbonates such as decabromodiphenyl ether, brominated polycarbonate obtained from tetrabromobisphenol A and phosgene, tetrabromobisphenol A and bisphenol A
And brominated copolymerized polycarbonate obtained from phosgene, halogenated epoxy compounds such as brominated epoxy compounds obtained from tetrabromobisphenol A and epichlorohydrin, brominated polystyrene, brominated polyphenylene oxide, and the like.

These may be those using only one type, or 2
A combination of two or more species may be used.

The nitrogen-containing compound is at least one nitrogen-containing compound selected from the group consisting of melamine, benzoguanamine, dimethylol urea, cyanuric acid and melamine cyanurate. Among these nitrogen-containing compounds, melamine and melamine cyanurate are preferably used. The nitrogen-containing compound, copper halide and meta-xylylenediamine,
It is more preferable to use a complex with a nitrogen-containing compound such as benzylamine, 2-mercaptobenzothiazole or 2-mercaptobenzimidazole, or a composite heat-resistant agent composed of copper halide and potassium halide.

Specific examples of the compound represented by the general formula (I) as a phosphorus compound include trimethyl phosphate,
Triethyl phosphate, triphenyl phosphate,
Tricresyl phosphate, cresyl diphenyl phosphate, diphenyloctyl phosphate, tributyl phosphate, tris (3-chloroethyl) phosphate, tris (dichloropropyl) phosphate, tris (2,3-dibromopropyl) phosphate, tris (bromochloropropyl) ) Phosphate, tris (2-bromoethyl) phosphate, trioctyl phosphate,
Tributoxyethyl phosphate and the like can be mentioned.

Specific examples of the compound represented by the general formula (II) include:
Examples include trimethyl phosphite, triethyl phosphite, tris (2-chloroethyl) phosphite, and triphenyl phosphite.

Specific examples of the compound represented by the general formula (III) include dimethyl phenylphosphonate, diethyl phenylphosphonate, dibutyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate, bis (hydroxyethyl) benzylphosphonate, bis ( 2
-Bromoethyl) 2-bromoethylphosphonate.

The compounds represented by the general formulas (I) to (III)
Species or two or more species may be used simultaneously.

Further, in the present invention, it is preferable to add a flame retardant aid, and examples of the flame retardant aid include antimony trioxide, magnesium oxide, molybdenum oxide, tin oxide, zirconium oxide, and zinc oxide.

Further, other flame retardants within a range that does not impair the properties of the composition of the present invention, for example, chlorinated paraffin, chlorinated polyethylene,
Perchloropentacyclodecane or the like may be used in combination.

The compounding amount of the flame retardant (C) is 5 to 60% by weight, preferably 1 to 100% by weight of the total of the components (A) to (C).
0 to 50% by weight. If the amount is less than 5% by weight, the flame retardancy cannot be said to be sufficient and there is a disadvantage that it is relatively easy to burn, which is not preferable. On the other hand, if the compounding amount exceeds 60% by weight, the physical properties of the resin are deteriorated due to poor dispersion, and the blooming phenomenon in which the compounded flame retardant precipitates on the resin surface after molding tends to occur, and the Izod impact strength,
It is not preferable because the tensile strength and elongation also decrease.

Next, as a method of producing the composition of the present invention, (A) a polyamide, (B) a modified polyester elastomer and (C) a flame retardant are mixed by a V-type blender, a Hensyl mixer, a super mixer, or the like, and this is directly melt-molded. Alternatively, the mixture may be melt-mixed with an extruder, a kneader, or the like, and then formed into chips and molded.

In the composition of the present invention, if necessary, a curing agent, a coupling agent, an antioxidant, an ultraviolet absorber, a light protectant, a phosphite stabilizer, a peroxide dispersant, a basic auxiliary, Nucleating agent,
It is also possible to add a plasticizer, a lubricant, an antistatic agent, an inorganic filler, a pigment, a dye, carbon black and the like.

(Function) (B) The modified polyester elastomer is obtained by a graft reaction of a polyester elastomer with a modifier selected from unsaturated carboxylic acids and derivatives thereof. It is presumed that the carboxylic acid and its derivative subjected to the above graft reaction partially react with the amino terminal group of the polyamide resin by being mixed under heating. It is presumed that this reaction promotes uniform miscible dispersion of the polyamide resin and the modified polyester elastomer, and thus can add heat resistance while maintaining the excellent properties of the polyamide resin.

In addition, when a flame retardant is added, compatibility between the polar group in the flame retardant and the terminal group of nylon or polyester elastomer is improved, the blooming phenomenon does not occur, and the flame retardancy is also improved. It is considered that almost no reduction in tensile properties and impact properties was observed.

(Examples) The present invention will be specifically described using examples, but the present invention is not limited to these. The flame retardancy, plate-out, blooming and mechanical properties shown in the examples were evaluated by the following measurements.

(1) Flame retardancy A test piece of 5in length, 1 / 2in width, 1 / 32in thickness, 1/16 "1/8" was prepared and UL-94 (Under Writers Laboratories, USA)
Inc.).

(2) Plate-out A disk having a diameter of 100 mm and a thickness of 3.2 mm was continuously shot with a mirror-finished die for 50 shots, and the mold surface and the molded product surface were visually observed.

(3) Blooming A disk with a diameter of 100 mm and a thickness of 3.2 mm is created and is
It was left in a 90% atmosphere for one week, and the surface condition was visually observed.

(4) Mechanical properties The tensile strength is in accordance with ASTM D638, and the Izod impact strength is in accordance with the method specified in ASTM D-256 using a 2.5 × 1/2 × 1/2 inch test piece. Each was measured.

In this embodiment, the polyamide resin has a relative viscosity of 2.53.
Nylon 6 (in 98% sulfuric acid; 1 g / 100 ml, 25 ° C.), nylon 6,6 having a relative viscosity of 2.51, and polymetaxylylene adipamide (MXD-6) having a relative viscosity of 2.10 were used. Vacuum-dried at 16 ° C for 16 hours before use.

Examples of the polyester elastomer include a polyether-polyester elastomer of polytetramethylene glycol and polytetramethylene terephthalate (Perprene P150B manufactured by Toyobo Co., Ltd.), and a polyester-type block copolymer of polycaprolactone and polytetramethylene terephthalate (manufactured by Toyobo Co., Ltd.) Pelprene S-1000) was used.

Table 1 shows the flame retardants and flame retardant auxiliaries used here.

Production Example Preparation of Modified Polyester Elastomer The above or 100 parts by weight, maleic anhydride 0.5 part by weight, and dicumyl peroxide 0.3 part by weight were uniformly mixed by a mixer. This mixture was supplied to a 30 mm twin screw extruder, and a maleic anhydride modification reaction was performed at a cylinder temperature of 200 to 230 ° C. The reaction product thus obtained is
The modified polyester elastomer 'or' was obtained by drying in a vacuum dryer at 80 ° C for 12 hours.

Examples 1 to 16, Comparative Examples 1 to 9 The above polyamide resin, the modified polyester elastomer 'or' obtained in the above production example and the flame retardant
After dry blending at the ratios shown in the table, pellets were produced using a 30 mmφ twin screw extruder. The cylinder temperature at that time is 250 ° C. for nylon 6, 280 ° C. for nylon 6,6, and 260 ° C. for MXD-6. The obtained pellets were vacuum-dried at 70 ° C. for 16 hours, and then each test piece was prepared at the same polymer temperature and mold 70 ° C. as in the twin screw extrusion. The results are shown in Tables 2 and 3.

As is clear from Tables 2 and 3, the compositions of the present invention obtained in Examples 1 to 16 have excellent properties in all of tensile strength and elongation, impact strength, flame retardancy, blooming properties and the like. You can see that In Comparative Examples 1 and 6, the flame retardancy was not improved because the flame retardant was not added.
In Nos. 5 and 7, since the polyester elastomer is not modified, the tensile strength and elongation and the impact strength are low, and the effect of the flame retardant is extremely low such as HB and V-2.

Examples 11 to 16 and Comparative Examples 8 and 9 are cases in which a nitrogen compound was used as a flame retardant.
It is understood that, since unmodified polyester elastomer is used, the tensile strength and elongation, impact strength and flame retardancy are low.

(Effect of the Invention) The composition of the present invention is a flame-retardant polyamide composition which does not cause blooming and has excellent physical properties such as tensile strength and elongation and impact resistance. It can be widely used for all kinds of daily necessities, including components and electronic components, and greatly contributes to the industrial world.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 77/00-77/12 C08L 67/00-67/08 C08K 3/00-13/08 CA (STN )

Claims (1)

(57) [Claims] 1. A modified polyester elastomer obtained by reacting (A) a polyamide resin, (B) a monomer selected from an unsaturated carboxylic acid and an unsaturated carboxylic acid derivative with a polyester elastomer, and (C) an organic compound. Halogen compounds, nitrogen-containing compounds and the following general formulas (I) to
A polyamide resin composition comprising one or more flame retardants selected from the phosphorus compounds represented by (III). (Wherein, R ₁ , R ₂ and R ₃ represent the same or different alkyl, haloalkyl, aryl and haloaryl groups, respectively)