JPH0198664A - Polyamide composition - Google Patents

Abstract

PURPOSE:To obtain the title nonblooming composition excellent in impact resistance, flame retardancy and moldability, by mixing a polyamide with a specified modified block (graft) copolymer and at least one flame retardant selected from among an organohalogen compound, a nitrogen compound and a phosphorus compound. CONSTITUTION:A hydrogenated block copolymer (a) is obtained by hydrogenating a block copolymer obtained by block-copolymerizing 5-60wt.% vinylaromatic compound such as styrene with 95-40wt.% conjugated diene compound such as butadiene to a degree of unsaturation <=20%. Component (a) is optionally graft-polymerized with a radical-degradable polymer such as PP or butyl rubber to obtain a block graft copolymer (a'). Component (a) or (a') is modified with a modifier containing a functional group which can bond to or react with component A to obtain a modified block (graft) copolymer (B). A polyamide (A) is mixed with component B, and a flame retardant (C) selected from among an organohalogen compound, a nitrogen compound and a phosphorus compound of any one of formula I-II [wherein R1-3 are each a (halo)alkyl or the like].

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to non-blooming, flame-retardant polyamide compositions containing a flame retardant and a modified block-graft copolymer.

The composition has excellent moldability and impact properties, particularly low-temperature impact properties, and can be widely used in the production of small automatic parts, electrical parts, mechanical parts, and various other molded products.

(Prior Art) Polyamide resins have been widely used in general household goods including electronic parts and small automatic parts because they have excellent properties such as being relatively inexpensive and easy to mold. However, polyamide resin is easily flammable, and once a fire occurs, it burns and disappears easily. Therefore, cable fires can have a particularly large impact on society.
I can do it.

Recently, therefore, flame retardation has been required by law in some of the fields in which these resins are used, such as electrical appliances, auto RLJ interior parts, and textile products. For example, the MVSS-302 flame retardant regulations for automobiles in the United States are known.

Generally, in order to impart flame retardancy to polyamide resin, a flame retardant is added when the resin is kneaded.

Flame retardants include inorganic compounds and organic phosphorus compounds, and in order to exhibit the flame retardant effect, it is necessary to increase the amount of the compound.As a result, the physical properties of the resin may deteriorate due to poor dispersion, and the compound may . ]-There was a drawback that the so-called blooming phenomenon, in which the flame retardant precipitated in powder form on the resin surface after molding, was likely to occur.

It is also known that a rubber-reinforced polyamide resin with excellent flame retardancy can be produced by adding a flame retardant to a rubber-reinforced polyamide resin. In polyamide resins, the rubber-reinforced polyamide resins before adding flame retardants have excellent properties, namely impact properties, especially at low temperatures. There was a drawback that the 1i impact properties were reduced by adding a flame retardant.

(Problems to be Solved by the Invention) The present invention provides a flame-retardant polyamide composition that has excellent impact properties, particularly low-temperature impact properties, and is free from blooming, which could not be solved by the methods known in the prior art. This is what I am trying to do.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present inventors aimed to obtain a composition that has excellent physical properties such as impact properties and heat resistance, and does not cause blooming. As a result of intensive research efforts, we have finally completed the present invention. That is, the present invention provides a hydrogenated block copolymer of (A) polyamide, (B) a copolymer consisting of a vinyl aromatic compound polymer block and a conjugated diene compound polymer block, or the block copolymer is hydrogenated. A block/graft copolymer in which the trunk portion and the graft portion are radically collapsible polymers is combined with the above IA) polyamide or phase 1i.
A modified block copolymer and/or a modified block graft copolymer to which molecular units containing functional molecules exhibiting an action are bonded, and (0) an organic halogen compound, a nitrogen-containing compound, and the following general formulas (I) to (III). This is a polyamide composition characterized by containing one or more flame retardants selected from the phosphorus compounds shown below.

(However, in the formula, R', R" and R" each represent the same or different alkyl, haloalkyl, aryl and haloaryl groups.) The polyamide used in the present invention is polycondensation of diamine and dicarboxylic acid, ω
- Obtained by self-condensation of amino acids, ring-opening polymerization of lactams, and has sufficient molecules 1k to produce molded articles. Specifically, polyhexamethylene adipamide,
Polyhexamethylene adipamide, polyhexamethylene apamide, polyhexamethylene dodecanoamide, polybis(4-aminocyclohexyl)methandodecanoamide,
polycaprolactam, polylauritulactam, poly-
Examples include 11-aminoundecanoic acid, metaxylylene adipamide, and copolymers thereof.

In the present invention, the block copolymer is obtained by hydrogenating a block copolymer consisting of a polymer block mainly composed of a vinyl aromatic compound polymer and a conjugated diene compound. Examples of the vinyl aromatic compound constituting the block copolymer before hydrogenation include styrene, α-methylstyrene, vinyltoluene, etc. Among them, styrene is particularly preferred. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, and the like, with butadiene and isoprene being particularly preferred. Furthermore, when hydrogenating a conjugated diene compound, the degree of unsaturation is 20% or less, preferably 1.
It is 0% or less. The copolymerization ratio of the vinyl aromatic compound and the conjugated diene compound before hydrogenation is 5795 to 60/40, and a weight ratio of 10/90 to 30/70 is particularly preferable.

Next, the radically collapsible polymer that becomes the graft part of the block graft copolymer with the block copolymer as the bone part is defined as
It is a polymer in which the disintegration reaction (molecular cleavage) takes precedence over the 111 bonding reaction and crosslinking reaction, resulting in a lower molecular weight.Specifically, polyisobutylene, polypropylene, polyα-methylstyrene, polymethacrylate, Polymethacrylamide, polyvinylidene chloride, cellulose, cellulose derivatives, polytetrafluoroethylene,
Examples include homopolymers such as polytrifluorochloroethylene, butyl rubber obtained by copolymerizing polyisobutylene with 1 to 3% imbutylene, and copolymers such as a copolymer of ethylene and propylene. Among these, butyl rubber is used in the present invention. is preferred.

In addition, the mixing ratio of the block copolymer and the radically decomposable polymer is preferably 20:1 to 1:2.

In the present invention, the block copolymer or block fist graft copolymer is modified by bonding a molecular unit containing a functional group that binds or interacts with the polyamide (hereinafter referred to as a modifier). Specifically, it is the tlt position of a molecule containing a carboxylic acid group, a sulfonic acid group, an amino group, or a derivative group thereof, and is modified by, for example, addition reaction with an unsaturated carboxylic acid or a derivative thereof. Examples of unsaturated carboxylic acids or derivatives thereof include maleic acid, acrylic acid, methacrylic acid, α-ethyl acrylic acid, fumaric acid, itaconic acid,
Citraconic acid, crotonic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, endo-cis-bicyclo(2
, 2, 1) unsaturated dicarboxylic acids such as -5-hebutene-2,3-dicarboxylic acid, and derivatives thereof such as acid halides, amides, imides, acid anhydrides, and esters.

The modifier is blended in an amount of 0.02% or more, preferably 0.1 to 2% by weight, based on the total amount of the block copolymer and radically decomposable polymer.

In the present invention, the modified block/graft copolymer can be obtained by melt-kneading the block copolymer, the radically decomposable polymer, and the modifier, or by melt-kneading the mixture together with a radical generator. It will be done. In addition, examples of the radical generator include known organic peroxides, diazo compounds, etc. Specific examples include benzoyl peroxide, dicumyl peroxide,
Examples include di-t-butyl peroxide, t-butylcumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, and azobisisobutyronitrile. The use fit of the radical generator is 0.01% by weight or more 1-1 preferably 0.03% based on the total amount of the block copolymer and the radically decomposable polymer
It is ~5%.

In the composition of the present invention, the content of the +[31 modified block copolymer and/or modified block/graft copolymer is 3 to 40% by weight, preferably 6 to 20% by weight. If the combination of 1[31] is less than 3%, it is not preferable because the impact properties, especially low-temperature impact properties, as expected from [1] cannot be obtained. On the other hand, if the blending amount exceeds 40% by weight and 6t%, the heat resistance
This is not preferable because the flame retardancy will be significantly lowered.

Next, the ta flame retardant blended in the present invention is determined by considering the thermal history received during the molding process of the polyamide composition.
Compounds with excellent heat resistance are preferred, and in the present invention, organic halogen compounds, nitrogen-containing compounds, and compounds of the general formulas (I) to
One or more flame retardants selected from the phosphorus compounds represented by (III) are employed, and organic halogen compounds are particularly preferred in the present invention.

The organic halogen compound refers to a compound that is generally treated as a halogen flame retardant, but in consideration of the heat history received during the molding process of the polyamide composition, aromatic halogen compounds with excellent heat resistance are preferred.

Specific examples include decabromodiphenyl ether, tetrabromobisphenol A and phosgene, and the resulting brominated polycarbonates, halogenated polycarbonates,
Brominated copolymerized polycarbonate obtained from tetrabromobisphenol A, bisphenol A and phosgene, halogenated epoxy compounds such as brominated epoxy compounds obtained from tetrabrobithroenol A and epichlorohydrin, brominated polystyrene, brominated polyphenylene oxide etc. can be mentioned.

Only one type of these may be used, or two or more types may be used in combination.

The nitrogen-containing compound is one or more nitrogen-containing compounds 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 is a complex of copper halide and a nitrogen-containing compound such as metaxylylene diamine, benzylamine, 2-mercaptobenzothiazole or 2-mercaptobenzimidazole, or a complex of copper halide and potassium halide. It is more preferable to use a heat resistant agent together.

Further, as a phosphorus compound, specific examples of the compound represented by the above general formula (I)- include trimethyl phosphate,
triethyl phosphate, triphenyl phosphate,
Tricresyl phosphate, talesyl diphenyl phosphate, diphenyloctyl phosphate, tributyl phosphate, tris(3-chloroethyl) phosphate, tris(dichloropropyl) phosphate, tris(2,3-dibromopropyl) phosphate, tris(
Examples thereof include bromochloropropyl phosphate, tris(2-bromoethyl) phosphate, trioctyl phosphate, and tributoxyethyl phosphate.

- Specific examples of the compound represented by general formula (II) include trimethyl phosphite, triethyl phosphite,
Examples include 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 and the like.

The compounds represented by formulas (I) to (III) above may be used alone or in combination of two or more.

Furthermore, 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, zinc oxide, and the like.

Further, other flame retardants such as hachlorinated paraffin, chlorinated polyethylene, perchloropentacyclodecane, etc. may be used in combination as long as the properties are not impaired.

The blending amount of the above (O flame retardant) is 5 to 60%, preferably 1% based on the total of the components (8) to (O)
It is 0 to 50% by weight. If the blending amount is 5% by weight at rice temperature,
It is undesirable because it has the disadvantage of being relatively flammable, with insufficient flame retardancy. On the other hand, if the blending ratio exceeds 60% by weight, the physical properties of the resin will be low due to poor dispersion, and the blooming phenomenon in which the blended flame retardant will precipitate in the form of powder on the resin surface after molding will occur. This is not preferable because the impact strength also decreases.

Next, as a method for producing the composition of the present invention, (A) polyamide, (B) modified block copolymer and/or modified block/graft copolymer particles and (0 flame retardant) are mixed in a V-type blender, The mixture may be mixed using a sill mixer, a super mixer, etc., and then directly melt-molded, or alternatively, the mixture may be melt-mixed using an extruder, kneader, etc., and then formed into chips, which may then be molded.

The composition of the present invention may contain mold release agents, coupling agents, antioxidants, ultraviolet absorbers, photoprotectants, phosphite stabilizers, peroxide dispersants, basic adjuvants, as required. , nucleating agents, plasticizers, lubricants, antistatic agents, inorganic fillers, pigments, dyes,
It is also possible to blend carbon black or the like.

(Function) The effect of the present invention was demonstrated by using polyamide (nylon 6 as Al, styrene/ethylene butylene/styrene block copolymer (hereinafter referred to as 5EBS) as a block copolymer, and maleic anhydride as a modifier. The following describes the case where flame retardants are added to the flame retardant.

For example, if brominated polystyrene is used as a flame retardant and antimony dioxide is used as a flame retardant aid, the brominated polystyrene and the S phase in 5EBS are compatible (they are compatible with each other, so additions within the scope of the claims are not required. In addition, antimony trioxide has a synergistic effect with the halogen in the flame retardant.Because of this compatibility, there is almost no decrease in impact strength. It is generally believed that this improves flame retardancy.

Although the explanation has been made regarding brominated polystyrene, other flame retardants within the scope of the claims may also be affected by compatibility due to the reaction between the polar group in the flame retardant and the terminal group of nylon, etc.
``Flame retardancy'' is recognized.

(Example) The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto. Incidentally, flame retardancy, plate-out, blooming and mechanical properties shown in Examples were evaluated by the following measurement methods.

(1) Flame retardant Length 51n1 Width 1/2in, Thickness 1/321n.

1/(B"l/8" test piece was prepared and UL-94(
US Under Wrestling Laborator
It was measured according to the method of the standard defined by ies Inc.

■ Plate out diameter 100m5, thickness 3.2 dragon disk with mirror mold 5
Observation of the mold surface and molded product surface after 0 consecutive shots.

■Blooming A disk with a diameter of 100 mm and a thickness of 3.2 mm was prepared and left in an atmosphere of 90% at 40°C for one week, and the surface condition was observed.

(4) Mechanical properties Tensile strength is in accordance with ASTM D638, and eye shift impact strength is 2.5X1/2X1/21n
Each measurement was performed using a ch test piece according to the method defined by ASTM D-256.

Reference Example 1 Styrene O olefin copolymer (Krayton G1650: manufactured by Showa Shell Chemical Co., Ltd.) as a block copolymer 10
0 parts by weight, butyl rubber (Kalar EX5-283
Nihardman Co., Ltd.), maleic anhydride, and dicumyl peroxide in the amounts shown in Table 1 were mixed together and triblended, followed by a melt-kneading reaction using a 40 mm single-screw extruder with a cylinder temperature of 220°C. Each sample was synthesized to obtain modified block/graft copolymers A-D.

Copolymers A-C obtained in Reference Example 1 in Table 1 and flame retardants, flame retardant aids alkali and nylon 6 (relative viscosity 2.40) shown in Table 2 are added in columns 3 to 5, respectively. Mix the amounts shown in the table,
30mm cylinder temperature set at 240~260℃
The mixture was melt-kneaded using a twin-screw extruder at a residence time of 1+J for 2 minutes and pelletized. The obtained pellet was dried in a vacuum dryer at 100°C for 16 hours, and then an ASTM test piece was prepared using a polymer temperature of 270°C and a mold of 76°C. The results are shown in the third
Also listed in Table 5.

As is clear from Table 2 and Tables 3 to 5 below, the compositions of the present invention obtained in Examples 1 to 14 have excellent impact strength (23°C to 30°C), flame retardancy, blooming property, and tensile strength. It can be seen that it has excellent characteristics in all respects. Also, Comparative Example 1.4.
No. 7 does not have flame retardancy compared to No. 4 because it does not contain a flame retardant.

In Comparative Examples 2 to 5 and 6 and 8, the styrene olefin-based R combination was not modified, so the impact strength was low, and the effect of the flame retardant was also extremely low compared to HBlV-2.

Examples 12 to 17 and Comparative Examples 9 to 12 are cases where a nitrogen compound is used as a flame retardant.
°I get it. Comparative Example 9 does not contain a third component such as the 1-1 flame retardant using a modified styrene-olefin copolymer, so the isot impact strength shows an extremely high value. It has low flame retardant effect and low tensile strength.

Comparative Examples 10 to 12 use unmodified styrene-olefin copolymers, so... It has low irradiation strength and low flame retardancy.

(Effects of the Invention) According to the present invention, a flame-retardant polyamide composition that does not cause blooming and has excellent physical properties such as impact resistance can be obtained.

In addition, the polyamide composition of the present invention can be widely used in general household goods including automatic parts and electronic parts like ordinary thermoplastic resins, and is suitable for use in the industrial world.

Claims (2)

[Claims] (1) A block copolymer obtained by hydrogenating a copolymer consisting of (A) polyamide, (B) a vinyl aromatic compound polymer block and a conjugated diene compound polymer block, or the block copolymer as a trunk portion. A modified block copolymer and/or a block graft copolymer in which the graft portion is a radically collapsible polymer, and a molecular unit containing a functional group that binds to or interacts with the polyamide (A). Containing a modified block/graft copolymer, and (C) one or more flame retardants selected from organic halogen compounds, nitrogen-containing compounds, and phosphorus compounds represented by the following general formulas (I) to (III). Characteristic polyamide composition. ▲There are mathematical formulas, chemical formulas, tables, etc.▼………………(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼……………………(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼………… ...(III) (However, in the formula, R_1, R_2 and R_3 each represent the same or different alkyl, haloalkyl, aryl and haloaryl groups.) (2) The polyamide composition according to claim (1), wherein the nitrogen-containing compound (C) is one or more selected from the group consisting of melamine, benzoguanamine, dimethylolurea, cyanuric acid, and melamine cyanurate.