JPH09143367A - Production of reinforced polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a reinforced polyamide resin compsn. excellent in mechanical strengths, toughness, heat resistance, and dimensional stability by polymerizing a monomer component for forming a polyamide in the presence of a specific mineral and a Lewis base. SOLUTION: This compsn. is produced by polymerizing a monomer component in an amt. for forming 100 pts.wt. polyamide (nylon 6 or its copolymer) in the presence of 0.01-100 pts.wt. swellable fluoromica mineral and a Lewis base in an amt. of 0.001-5mol% based on the monomer component. Pref. the Lewis base is a compd. having at least one atom selected from among N, P, O, and S atoms having an unshared electron pair. Pref. the mineral is one obtd. by heating a mixture of talc and sodium or lithium fluoride or silicofluoride.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reinforced polyamide resin composition comprising a polyamide (nylon 6 or a copolymer thereof) and a swelling fluoromica-based mineral and having excellent mechanical strength, toughness, heat resistance and dimensional stability. It relates to a method of manufacturing a product.

[0002]

2. Description of the Related Art A resin composition in which polyamide is reinforced with fibrous material such as glass fiber or carbon fiber and inorganic filler such as calcium carbonate is widely known. However, these reinforcing materials have a poor affinity with polyamide, and although the mechanical strength and heat resistance of the reinforced polyamide are improved, the toughness is reduced, and in the resin composition reinforced with fibrous material, the warpage of the molded product is There is a problem of getting bigger. Moreover, the resin composition reinforced with these inorganic fillers has a problem that the mechanical strength and heat resistance cannot be improved unless a large amount of the filler is blended.

As an attempt to improve the drawbacks of such a reinforced polyamide, a resin composition comprising a polyamide and a clay mineral represented by montmorillonite has been proposed.
For example, JP-A-62-74957, JP-A-63-230760, JP-A-1-301750, JP-A-2-86628 and JP-A-3-7729 disclose resin compositions comprising polyamide and montmorillonite. Is disclosed.

This resin composition is intended to form a composite in which polyamide chains are finely and uniformly dispersed by infiltrating polyamide chains between layers of clay minerals. When montmorillonite is used for such a purpose, each of the above publications is used. As described in, prior to blending the montmorillonite with the polyamide or the monomer forming the polyamide, it was essential to treat the montmorillonite with the swelling agent such as an amino acid to increase the interlayer distance of the montmorillonite. . Therefore, there has been a strong demand in the art for an inorganic filler that does not require such treatment and can solve the drawbacks of conventional polyamide resins.

As an attempt to solve such a problem,
The present inventors previously proposed a method for producing a reinforced polyamide resin composition by adding a swelling fluoromica-based mineral to a polyamide-forming monomer and polymerizing the same (JP-A-6-24).
8176 publication). According to this method, unlike the case of using a conventional clay mineral typified by montmorillonite, it is possible to obtain a resin composition excellent in mechanical strength, toughness, heat resistance and dimensional stability without performing a swelling treatment. I was able to.

However, in order to obtain a resin composition having excellent performance, it is necessary to employ a high-pressure polymerization method in which polymerization is carried out at a pressure of 10 kg / cm ² or more, and a special polymerization apparatus is required. there were.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a method for producing a reinforced polyamide resin composition by adding a swelling fluoromica-based mineral to a monomer forming a polyamide (nylon 6 or a copolymer thereof) and polymerizing the monomer. In order to provide a reinforced polyamide resin composition excellent in mechanical strength, toughness, heat resistance and dimensional stability without using a high pressure polymerization method.

[0008]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and its gist is polyamide (nylon 6
Or its copolymer) 0.01 to 100 parts by weight of a swelling fluoromica-based mineral with respect to the amount of a monomer forming 100 parts by weight, and a Lewis base against
A method for producing a reinforced polyamide resin composition, which comprises polymerizing a monomer in the presence of 0.001 to 5 mol%.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The polyamide targeted by the present invention is nylon 6 or a copolymer thereof, and the monomer forming nylon 6 is ε-caprolactam and / or 6-aminocaproic acid.

The copolymerizable monomer includes various aminocarboxylic acids or lactams and nylon salts, specifically, 11-aminoundecanoic acid, 12-aminododecanoic acid,
Para-aminomethylbenzoic acid, ω-laurolactam, nylon 46 salt, nylon 66 salt, nylon 610 salt, nylon 6T
Examples thereof include salts, nylon 6I salts, and salts of metaxylylenediamine and adipic acid.

In the present invention, when nylon 6 or its copolymer is produced, a swellable fluoromica-based mineral is added to the monomer for polymerization.

The swelling fluoromica mineral used in the present invention is represented by the following formula. αMF · β (aMgF ₂ · bMgO) · γSiO ₂ (where M represents sodium or lithium, α, β,
γ, a and b represent coefficients, respectively, 0.1 ≦ α ≦ 2, 2 ≦ β
≦ 3.5, 3 ≦ γ ≦ 4, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, a + b
= 1. )

As a method for producing such a fluoromica-based mineral, there is a method in which talc is used as a starting material and alkali ions are intercalated into the starting material to obtain a fluoromica-based mineral. In this method, talc is mixed with alkali silicofluoride or alkali fluoride, and 700
Fluorine mica-based minerals can be obtained by heat treatment at ~ 1200 ° C for a short time. The swellable fluoromica-based mineral used in the present invention is particularly preferably produced by this method.

The amount of alkali silicofluoride or alkali fluoride to be mixed with talc is preferably 10 to 35% by weight of the mixture. If it is out of this range, the production rate of swelling fluoromica-based minerals descend.

To obtain a swellable fluoromica-based mineral,
The alkali silicofluoride or alkali metal of the alkali fluoride must be sodium or lithium.

These alkali metals may be used alone or in combination. Of the alkali metals, potassium is not preferred because it does not give a swelling fluoromica-based mineral, but it may be used in combination with sodium or lithium, and may be used for the purpose of adjusting the swelling property in a limited amount. It is possible.

Further, in the step of producing the swellable fluoromica-based mineral, it is possible to mix a small amount of alumina to control the swelling property of the swellable fluoromica-based mineral produced.

The term "swelling property" as used in the present invention means that fluoromica absorbs polar molecules or cations such as aminocarboxylic acid, nylon salt, and water between layers to increase the interlayer distance, or further swelling and cleavage. This means the property of forming ultrafine particles, and the fluoromica-based mineral represented by the above formula exhibits such swelling property.

The swelling fluoromica mineral has a side of 10 μm.
Hereinafter, the thickness is 0.1 μm or less, and c measured by X-ray powder method
A layer thickness in the axial direction of 9 to 20Å is preferable.

The swellable fluoromica-based mineral is used in an amount of 0.01 to 100 parts by weight, preferably 0.1 to 20 parts by weight, and most preferably 1 to 10 parts by weight, based on 100 parts by weight of the polyamide produced. It is compounded at the time of polymerization. If the amount is too small, the effect of improving mechanical strength, heat resistance and dimensional stability is not sufficiently exhibited, and if it is too large, the toughness is greatly reduced.

With respect to the monomers forming the polyamide,
By polymerizing the monomer in the presence of a predetermined amount of the swellable fluoromica mineral, the swellable fluoromica mineral is sufficiently finely dispersed in the polyamide to obtain a polyamide resin composition having excellent mechanical properties and the like. .

The Lewis base used in the present invention is a compound containing in the molecule one or more atoms selected from N, P, O and S atoms having an unshared electron pair.

Specific examples thereof include dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, isopropylamine, allylamine, n-butylamine, sec-
Butylamine, tert-butylamine, ethylenediamine, diethylenetriamine, triethylenetetramine,
Tetramethylenediamine, hexamethylenediamine, dodecanemethylenediamine, aniline, benzylamine,
Toluidine, amines such as α-naphthylamine, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, tert-butyl alcohol, ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, 2,3-dimercapto-
Alcohols such as 1-propanol, phenol, hydroquinone, catechol, phenolic compounds such as cresol, phosphine, trimethylphosphine, triethylphosphine, triphenylphosphine, phosphine such as dimethylphenylphosphine, ethanethiol, thiophenol, ethanedithiol, Thiols such as 1,3-dithiane may be mentioned.

The Lewis base is added in an amount of 0.001 to 5 mol%, preferably 0.
05-1.0 mol% is good. If it is less than 0.001 mol%, the effect is small, and if it exceeds 5 mol%, a polymer having a high degree of polymerization cannot be obtained.

To carry out the method of the present invention, a swelling fluoromica-based mineral, a Lewis base and pure water (polymerization initiator) are added in a predetermined amount to a monomer forming a polyamide to carry out ordinary polymerization of nylon 6. Polymerization may be carried out under similar conditions. The swelling fluoromica-based mineral does not need to be subjected to the swelling treatment in advance, and may be added to the monomer as it is. The pressure during polymerization does not have to be high, and the pressure during suppression is 5 kg / c.
m ^{2 is} enough.

The polymerization must be carried out until a resin having a high degree of polymerization is obtained, 96% sulfuric acid is used as a solvent, and the temperature is 25 ° C.
It is preferable to obtain a relative viscosity in the range of 1.5 to 5.0 obtained under the condition of a concentration of 1.0 g / dl. When the relative viscosity is less than 1.5, the mechanical performance of the resin composition deteriorates, and when the relative viscosity exceeds 5.0, the moldability of the resin composition rapidly decreases, which is not preferable. After the melt polymerization, solid phase polymerization may be carried out if necessary.

To the reinforced polyamide resin composition, a pigment, a heat stabilizer, an antioxidant, a weather resistance agent, a flame retardant, a plasticizer, a release agent, a toughening agent, etc. should be added as long as the characteristics are not significantly impaired. Is also possible.

As the heat stabilizer and antioxidant, for example, hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides or mixtures thereof can be used.
In particular, copper compounds and halides of alkali metals are most effective.

Examples of the reinforcing agent include clay, talc,
Calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, asbestos, sodium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcide , Metal fibers, metal whiskers, ceramic whiskers, potassium titanate whiskers, boron nitride, graphite, glass fibers, carbon fibers and the like.

These additives are added at the time of polymerization or when the obtained resin composition is melt-kneaded or melt-formed.

The resin composition obtained by the method of the present invention can be used as a mixture with another polymer. Specific examples of such a polymer include polyamides other than nylon 6 or its copolymers, such as polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene se Bacamide (nylon
610), polyhexamethylene dodecamide (nylon 61
2) Polyundecamethylene adipamide (nylon 11
6), polyundecane amide (nylon 11), polydodecane amide (nylon 12), polytrimethylhexamethylene terephthalamide nylon TMHT), polyhexamethylene isophthalamide (nylon 6I), polyhexamethylene terephthal / isophthalamide (nylon 6T / 6
I), polybis (1-aminocyclohexyl) methandodecamide (nylon PACM12), polybis (3-methyl-
4-Aminocyclohexyl) methandodecamide (nylon dimethyl PACM12), polymetaxylylene adipamide (nylon MXD6), polyundecamethylene terephthalamide (nylon 11T), polyundecamethylene hexahydroterephthalamide (nylon 11T (H) ) Etc.,
In addition, elastomers such as polybutadiene, butadiene-styrene copolymer, acrylic rubber, ethylene-propylene copolymer, ethylene-propylene-butadiene copolymer, natural rubber, chlorinated butyl rubber, chlorinated polyethylene, and maleic anhydride thereof. Acid-modified products with acids, styrene-maleic anhydride copolymer, styrene-
Phenylmaleimide copolymer, polyethylene, polypropylene, butadiene-acrylonitrile copolymer, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyvinylidene fluoride, polysulfone, polyphenylene sulfide, polyether sulfone, phenoxy resin, polyphenylene ether, poly Methyl methacrylate, polyether ketone, polycarbonate, polytetrafluoroethylene, etc. are available.

The resin composition obtained by the method of the present invention can be made into a desired molded article by a usual molding method.
For example, a method of forming a molded article by a hot melt molding method such as injection molding, extrusion molding, blow molding, and sintering molding, or a casting method from an organic solvent solution can be adopted.

The resin composition obtained by the method of the present invention is remarkably improved in mechanical strength, heat resistance and dimensional stability as compared with the case of using polyamide alone, and has little change in mechanical properties and dimensions due to water absorption. . Due to its excellent performance, this resin composition is used for mechanical parts and housings such as switches and connectors in the field of electric and electronic equipment, underbonnet parts and exterior parts in the field of automobiles, optical parts such as outer plate parts or reflectors, or machinery. Used as a gear and bearing retainer in the field.

[0035]

Next, the present invention will be described more specifically with reference to examples. The raw materials and measuring methods used in Examples and Comparative Examples are as follows. 1. Raw material (1) Swelling fluoromica mineral Mineralized talc crushed with a ball mill to an average particle size of 2 μm, so that the silica fluoride shown in Table 1 with an average particle size of 2 μm accounts for 15% by weight of the total amount. , Put it in a magnetic crucible and hold it in an electric furnace at 800 ° C for 1 hour.
M-1 and M-2 fluoromica-based minerals were synthesized. As a result of measuring the generated fluoromica-based mineral by an X-ray powder method, the peak corresponding to the thickness of the raw material talc in the c-axis direction of 9.2 Å disappeared, and the peak corresponding to 12 to 16 Å indicating the formation of swellable fluoromica-based mineral Was recognized.

[0036]

[Table 1]

(2) Lewis base (all manufactured by Nacalai Tesque, special grade) Hexamethylenediamine (HMDA) Aniline Ethylene glycol (EG) Ethandithiol (EDTO) 2. Measurement method (1) Tensile strength and breaking elongation Measured based on ASTM D638. (2) Izod impact strength Based on ASTM D256, it measured using the test piece of thickness 3.2mm. (3) based on the heat distortion temperature (HDT) ASTM D648, load 18.6 kg / cm ² and 4.5 kg / cm ²
Was measured. (4) Dimensional change Using a square test piece with a thickness of 2 mm and a width of 50 mm, measure the dimensional change in the thickness direction, vertical direction and horizontal direction by water absorption treatment,
The average value was taken as the dimensional change. (5) Water absorption rate Using the same test piece as above, it was determined from the weight change after water absorption treatment. The water absorption treatment was performed by treating the test piece for 24 hours under the conditions of 60 ° C. and 95% RH.

Examples 1 to 5 1 kg of water and M-1 per 10 kg of ε-caprolactam
(Or M-2) and Lewis base were blended in the amounts shown in Table 2, put in a reactor having an internal volume of 30 liters, heated to 260 ° C with stirring, and pressurized to a pressure of 5 kg / cm ^2. did. Then, the pressure was released to normal pressure, and polymerization was carried out at 260 ° C. for 3 hours. At the time of completion of the polymerization, the reaction product was discharged in the form of a strand, cooled, solidified, and cut into pellets made of a reinforced nylon 6 resin composition. The resulting pellets were treated with hot water at 95 ° C. to scour and dry. The pellets were supplied to an injection molding machine and injection-molded at a cylinder temperature of 260 ° C. and a mold temperature of 70 ° C. to form a test piece. Table 2 shows the results of performance evaluation of the obtained test pieces.

[0039]

[Table 2]

[0040] was not added Comparative Example 1-4 Lewis base, except that the pressure during the polymerization was polymerized by changing from 5 kg / cm ² as shown in Table 3 to 15 kg / cm ² in the same manner as in Example 1 reinforced Pellets of the nylon 6 resin composition were obtained. A test piece was molded in the same manner as in Example 1, and the results of performance evaluation performed using the obtained test piece are shown in Table 3.

[0041]

[Table 3]

Comparative Example 5 ε-caprolactam was polymerized in the same manner as in Example 1 except that the amount of Lewis base added was changed to 10 mol%. It was not possible to obtain a high molecular weight reinforced nylon 6 resin composition that could be used for molding because the amount of the Lewis base was large.

According to the present invention, in a method for producing a reinforced polyamide resin composition by adding a swelling fluoromica mineral to a monomer for molding a polyamide (nylon 6 or a copolymer thereof) and polymerizing it, It is possible to obtain a reinforced polyamide resin composition having excellent mechanical strength, toughness, heat resistance, and dimensional stability without using a high-pressure polymerization method.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Izumi Yoshida 23 Uji Kozakura, Uji-city, Kyoto Pref.

Claims (4)

[Claims] 1. Lewis acid is added to 0.01 to 100 parts by weight of a swellable fluoromica-based mineral and 100 to parts by weight of a polyamide (nylon 6 or a copolymer thereof) and a monomer to form a polyamide. A method for producing a reinforced polyamide resin composition, which comprises polymerizing a monomer in the presence of 0.001 to 5 mol% of a base. 2. The compound in which the Lewis base contains at least one atom selected from N, P, O, and S atoms having an unshared electron pair in the molecule.
A method for producing the reinforced polyamide resin composition described. 3. The swellable fluoromica mineral is obtained by heating a mixture of talc and sodium and / or lithium silicofluoride or fluoride.
A method for producing the reinforced polyamide resin composition described. 4. The swellable fluoromica-based mineral is talc 90-
The method for producing a reinforced polyamide resin composition according to claim 3, which is obtained by heating a mixture of 65% by weight and sodium and / or lithium silicofluoride or 10 to 35% by weight of a fluoride.