JP2941159B2 - Reinforced polyamide resin composition and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has excellent mechanical strength, toughness and heat resistance comprising a polyamide and a specific fluoromica-based mineral.
The present invention also relates to a reinforced polyamide resin composition having small mechanical strength and dimensional change due to water absorption , and a method for producing the same.

[0002]

2. Description of the Related Art Resin compositions in which polyamide is reinforced with a fibrous material such as glass fiber or carbon fiber or an inorganic filler such as calcium carbonate are widely known. However, these reinforcing materials have poor affinity with polyamide, and although the mechanical strength and heat resistance of the reinforced polyamide are improved, the toughness is reduced,
In addition, the resin composition reinforced with fibrous material has a problem that the warpage of the molded article is increased. In addition, the resin compositions reinforced with these inorganic fillers have the problem that the mechanical strength and heat resistance do not improve unless the fillers are blended in large amounts.

As an attempt to improve the disadvantages of the reinforced polyamide, a resin composition comprising a polyamide and a clay mineral represented by montmorillonite has been proposed.
The purpose of this method is to produce a finely and uniformly dispersed composite by infiltrating a polyamide chain between layers of a clay mineral.
No. 57, JP-A-1-301750, JP-A-2
JP-A-866628 and JP-A-3-7729 disclose a resin composition comprising polyamide and montmorillonite, and a method for producing the same.

However, when montmorillonite is used for such a purpose, as described in the above-mentioned publications, polyamide or a monomer for forming polyamide is used.
Before blending the montmorillonite with the swelling agent, a treatment for increasing the interlayer distance of the montmorillonite by contacting it with a swelling agent such as an amino acid was essential. Therefore, in the industry, such processing is unnecessary,
There has been a strong demand for inorganic fillers that can overcome the disadvantages of conventional reinforced polyamide resins.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and has excellent mechanical strength, toughness and heat resistance without warpage of a molded product, and has a high mechanical strength due to water absorption.
It is an object of the present invention to provide a reinforced polyamide resin composition having a small degree or dimensional change , and an excellent production method which does not require a step of previously contacting an inorganic filler to be mixed with polyamide with a swelling agent.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve such problems, and as a result, a reinforced polyamide resin composition comprising a polyamide and a specific fluoromica-based mineral has been improved. The inventors have found that the present invention has high performance and that the object of the present invention can be more effectively solved by using a specific manufacturing method, and has reached the present invention.

That is, the gist of the present invention is as follows. 1. The monomer is polymerized in a state where 0.2 to 20 parts by weight of a swellable fluoromica-based mineral represented by the following formula (1) is present based on the amount of the monomer forming 100 parts by weight of polycaproamide (nylon 6). A reinforced polyamide resin composition obtained by the above method, having a tensile strength value of 470 kg / cm ² or more based on ASTM D638 after water absorption treatment (24 hours under conditions of 60 ° C. and 95% RH). Reinforced polyamide resin composition. α (MF) · β (aMgF ₂ · bMgO) · γSiO ₂ (1) (where M represents sodium or lithium, α,
β, γ, a and b each represent a coefficient, and 0.1 ≦ α ≦
2, 2 ≦ β ≦ 3.5, 3 ≦ γ ≦ 4, 0 ≦ a ≦ 1, 0 ≦ b
≦ 1, a + b = 1. ) 2. Polyhexamethylene adipamide (nylon 66),
100 parts by weight of a polyamide selected from polytetramethylene adipamide (nylon 46) and polydodecanamide (nylon 12) and 0.2 to 20 parts by weight of a swellable fluoromica-based mineral represented by the formula (1) And a water-absorbing treatment (60 ° C., 95% R
A reinforced polyamide resin composition having a tensile strength value of 470 kg / cm ² or more based on ASTM D638 after 24 hours under H conditions). 3. A method for producing a reinforced polyamide resin composition, characterized in that a monomer is polymerized in a state where 0.2 to 20 parts by weight of a swellable fluoromica-based mineral is present relative to the amount of a monomer forming 100 parts by weight of a polyamide.

The polyamide used in the present invention means a polymer having an amide bond formed from an amino acid, a lactam or a diamine and a dicarboxylic acid. The following are examples of monomers for forming such a polyamide. Examples of amino acids include 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid.

As lactams, ε-caprolactam, ω
-Laurolactam and the like. Diamines include tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,2
4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 2,4-dimethyloctamethylenediamine, meta-xylylenediamine,
Para-xylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-
3,5,5-trimethylcyclohexane, 3,8-bis (aminomethyl) tricyclodecane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis ( 4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine and the like.

The dicarboxylic acids include adipic acid, suberic acid, azelaic acid, sebacic acid, dodecane diacid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid,
-Chloroterephthalic acid, 2-methylterephthalic acid, 5-
Examples include methyl isophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, and diglycolic acid.

Preferred polyamides for use in the present invention include polycaproamide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), and polyhexamethylene sebacamide. (Nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecamethylene adipamide (nylon 116), polyundecaneamide (nylon 11), polydodecaneamide (nylon 12), polytrimethylhexamethylene terephthalamide ( Nylon TMHT), polyhexamethylene isophthalamide (nylon 6I), polyhexamethylene terephthal / isophthalamide (nylon 6T / 6I), polybis (4-aminocyclohexyl) methane dodecamide,
(Nylon PACM12), polybis (3-methyl-4)
-Aminocyclohexyl) methandodecamide (nylon dimethyl PACM12), polymethaxylylene adipamide (nylon MXD6), polyundecamethylene terephthalamide (nylon 11T), polyundecamethylene hexahydroterephthalamide (nylon 11T
(H)) and their copolymerized polyamides and mixed polyamides. Among them, nylon 6 is particularly preferable.
Nylon 46, Nylon 66, Nylon 11, Nylon 12, and their copolyamides and mixed polyamides.

The polyamide used here is usually produced by a known melt polymerization method or further by a solid phase polymerization method. Although the relative viscosity of the polyamide used in the present invention is not particularly limited, phenol / tetrachloroethane = 60/40 (weight ratio) is used as a solvent and the temperature is 2
The relative viscosity obtained at 5 ° C. and the concentration of 1 g / dl was 1.5
To 5.0. When the relative viscosity is less than 1.5, the mechanical performance of the resin composition decreases, which is not preferable. Conversely, if it exceeds 5.0, the moldability of the resin composition rapidly decreases, which is not preferable.

The swellable fluoromica-based mineral used in the present invention is obtained by heat-treating talc and a mixture of sodium and / or lithium silicofluoride or fluoride. The specific method is described in JP-A-2-149415.
There is a method disclosed in Japanese Patent Publication No. That is, this method uses talc as a starting material, and intercalates sodium ions and / or lithium ions into the starting material to obtain a swellable fluoromica-based mineral. In this method, a fluoromica-based mineral can be obtained by mixing talc with a silicofluoride and / or a fluoride, and subjecting the mixture to a heat treatment at about 700 to 1200 ° C. for a short time in a porcelain crucible. The swellable fluoromica-based mineral used in the present invention is particularly preferably produced by this method.

In order to obtain a swellable fluoromica-based mineral, it is necessary that the metal constituting the silicofluoride or the fluoride is sodium or lithium among alkali metals. These alkali metals may be used alone or in combination. Of the alkali metals, potassium is not preferable because a swellable fluoromica-based mineral cannot be obtained.However, it is used in combination with sodium or lithium and used for the purpose of adjusting the swellability in a limited amount. Is also possible. The amount of silicofluoride and / or fluoride mixed with talc is 10% of the whole mixture.
If the amount is out of this range, the rate of generation of the swellable fluoromica-based mineral decreases.

The swellable fluoromica-based mineral produced by the above method has a general formula represented by the following formula (1). α (MF) · β (aMgF ₂ · bMgO) · γSiO ₂ (1) (where M represents sodium or lithium, α,
β, γ, a and b each represent a coefficient, and 0.1 ≦ α ≦
2, 2 ≦ β ≦ 3.5, 3 ≦ γ ≦ 4, 0 ≦ a ≦ 1, 0 ≦ b
≦ 1, a + b = 1. )

In the present invention, the term "swelling property" means that a fluoromica-based mineral absorbs polar molecules or cations such as amino acids, nylon salts and water molecules between layers, thereby increasing the interlayer distance or further swelling. This is the characteristic of becoming ultrafine particles. The fluoromica-based mineral represented by the formula (1) exhibits such a swelling property. The preferred size of the swellable fluoromica-based mineral used in the present invention is 10 μm or less on one side,
The thickness is 0.1 μm or less. The swellable fluoromica-based mineral used in the present invention has a layer thickness in the C-axis direction of 9 to 20 ° as measured by an X-ray powder method.

In the step of producing the swellable fluoromica-based mineral used in the present invention, a small amount of alumina (Al ₂ O ₃ ) may be added to adjust the swellability of the generated swellable fluoromica-based mineral. is there.

The amount of the swellable fluoromica-based mineral is 100 to 100 parts by weight of the polyamide or 0.2 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on the amount of the monomer forming the polyamide. The mechanical strength is less than 0.2 parts by weight for the purpose of the present invention, heat resistance can not be obtained the effect of improving the dimensional stability, since the decrease in toughness is increased when it exceeds 20 parts by weight is not preferable.

As a method for producing the reinforced polyamide resin composition of the present invention, there is a method in which a polyamide and a swellable fluoromica-based mineral are melt-kneaded using a general extruder. It is preferable to use a twin-screw extruder for bettering. In this case, the swellable fluoromica-based mineral used in the present invention does not need to be subjected to a swelling treatment in advance like montmorillonite, and can be directly blended and melt-kneaded.

The most preferred method for producing the reinforced polyamide resin composition of the present invention is to strengthen the polymer by polymerizing a monomer in the presence of a predetermined amount of a swellable fluoromica-based mineral with respect to the monomer forming the polyamide. This is a method for obtaining a polyamide resin composition. In this case, the swellable fluoromica-based mineral is sufficiently finely dispersed in the polyamide, and the effect of the present invention appears most remarkably. Also in this case, the swellable fluoromica-based mineral used in the present invention does not need to be subjected to a swelling treatment in advance, and may be mixed with a monomer in a predetermined amount and polymerized as it is.

The reinforced polyamide resin composition of the present invention contains a pigment, a heat stabilizer, an antioxidant, a weathering agent, a flame retardant, a plasticizer, a release agent, other reinforcing materials, etc. as long as the properties are not significantly impaired. It is also possible to add. As the heat stabilizer and the antioxidant, for example, hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides, and mixtures thereof can be used. In particular, copper compounds and halides of alkali metals are most effective. These additives such as heat stabilizers, antioxidants, and weathering agents are generally added during melt-kneading or polymerization. Examples of the reinforcing material include clay, talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide,
Calcium silicate, asbestos, sodium aluminate, calcium aluminate, sodium aluminosilicate,
Magnesium silicate, glass balloon, carbon black, zinc oxide, antimony trioxide, zeolite, hide
Rotarsite , metal fibers, metal whiskers , ceramic whiskers, potassium titanate, titanium borate, graphite, glass fibers, carbon fibers, and the like.

Further, if necessary, another polymer can be added to the resin composition of the present invention. Such polymers include polybutadiene, butadiene-styrene copolymer, acrylic rubber, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, natural rubber, chlorinated butyl rubber, elastomers such as chlorinated polyethylene, and These acid-modified products such as maleic anhydride, styrene-maleic anhydride copolymer, styrene-phenylmaleimide copolymer, polyethylene, polypropylene, butadiene-acrylonitrile copolymer, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, Polyacetal, polyvinylidene fluoride, polysulfone, polyphenylene sulfide,
Examples include polyether sulfone, phenoxy resin, polyphenylene ether, polymethyl methacrylate, polyether ketone, polyarylate, polycarbonate, and polytetrafluoroethylene.

The resin composition of the present invention can be used to form a desired molded article by a usual molding method. For example, a thin film can be formed by a hot melt molding method such as injection molding, extrusion molding, blow molding, or sinter molding, or a casting method from an organic solvent solution. The resin composition of the present invention has remarkably improved mechanical strength, heat resistance and dimensional stability as compared with the case of using polyamide alone, and has small mechanical strength and dimensional change due to water absorption. The resin composition of the present invention has excellent performance,
It is used for mechanical parts and housings such as switches and connectors in the field of electrical and electronic equipment, underbonnet parts and exterior parts in the field of automobiles, optical parts such as outer panel parts and reflectors, and gears and bearing retainers in the field of machinery.

[0024]

EXAMPLES The present invention will be described more specifically with reference to the following examples. In addition, the raw materials and measuring methods used in the evaluation of the examples and comparative examples are as follows. (1) Raw materials Fluorine-mica-based mineral Based on talc ground to a mean particle size of 2 μm with a ball mill, silicate, fluoride or alumina having an average particle size of 2 μm as shown in Table 1 is 20% by weight of the total amount. The mixture was placed in a porcelain crucible, and kept at 800 ° C. for 1 hour in an electric furnace to synthesize M-1 to M-7 fluoromica-based minerals. As a result of measuring the generated fluoromica-based mineral by the X-ray powder method, the peak corresponding to the thickness of 9.2% in the C-axis direction of the raw material talc disappeared for M-1 to M-6, and the swellable fluoromica-based mineral was removed. 12 to 16 showing generation of
A peak corresponding to Å was observed.

[0025]

[Table 1]

[0026] 2. Clay mineral and inorganic filler used in Comparative Examples Montmorillonite (Nippon Talc) Kaolin (Shiraishi Kogyo)

(2) Measurement method Tensile strength and elongation at break Measurement was performed based on ASTM D638. 2. Izod impact test Based on ASTM D256, a 3.2 mm thick test piece was used. 3. Heat Deformation Temperature (HDT) This was performed based on ASTM D648. Load is 18.6
The tests were performed at kg / cm ² and 4.5 kg / cm ² . 4. Moisture Absorption Treatment The test piece was treated at 60 ° C. and 95% RH for 24 hours. 5. Dimensional change Using a square test piece having a thickness of 2 mm and a side of 50 mm, the thickness and vertical and horizontal dimensional changes were measured, and the average value was taken as the dimensional change. 6. The water absorption was determined from the weight change after the moisture absorption treatment using the same test piece as described above.

Examples 1 to 5 10 kg of ε-caprolactam, 2 kg of water and M
-1, M-2 and M-3 were mixed with each other in the amounts listed in Table 2 with respect to ε-caprolactam.
In a 1 l reaction vessel, ε-caprolactam was polymerized in the presence of a swellable fluoromica-based mineral to obtain a reinforced nylon 6 resin composition. The polymerization reaction was performed as follows. That was heated with stirring to 250 ° C., while gradually releasing the water vapor to be boosted from 4 kg / cm ² to a pressure of 15 kg / cm ^2. Thereafter, the pressure was released to a pressure of ² kg / cm ² , and polymerization was carried out at 260 ° C. for 3 hours. At the end of the polymerization, the reinforced nylon 6 resin composition was discharged from the reactor and cut into pellets. The obtained pellets of the reinforced nylon 6 resin composition were treated with hot water at 95 ° C., scoured, dried, and provided for forming test pieces. The test piece was molded using an injection molding machine at a cylinder temperature of 260 ° C and a mold temperature of 8
Performed at 0 ° C. Various performance evaluations were performed using the obtained test pieces. The results are shown in Table 2.

[0029]

[Table 2]

Examples 6 to 10 For 10 kg of nylon 66 salt, 3 kg of water and M-
1, M-2 and M-3 were blended in the amounts listed in Table 3 with respect to Nylon 66 salt, respectively, and placed in a reaction vessel having a content of 30 liters. 66 salt was polymerized to obtain a reinforced nylon 66 resin composition. The polymerization reaction was performed as follows. That is, while stirring at 230 ° C., heating was performed until the internal pressure reached 18 kg / cm ² . After reaching the pressure, the pressure was maintained by heating while gradually releasing water vapor. When the temperature reached 280 ° C., the pressure was released to normal pressure, and the polymerization was further performed for 2 hours. When the polymerization was completed, the reinforced nylon 66 resin composition was discharged and cut into pellets. The pellets were dried and used for forming test pieces. The test piece was molded using an injection molding machine at a cylinder temperature of 290 ° C and a mold temperature of 80.
C. was performed. Various performance evaluations were performed using the obtained test pieces. The results are shown in Table 3.

[0031]

[Table 3]

Examples 11 to 13 M-4, M-5 instead of M-1, M-2 and M-3
Example 1 except that M-6 and M-6 were used in the amounts listed in Table 4.
5 to obtain a nylon 6 reinforced resin composition. Test pieces were molded in the same manner as in Examples 1 to 5, and various performance evaluations were performed using the obtained test pieces. The results are shown in Table 4.

[0033]

[Table 4]

Examples 14 to 16 Instead of M-1, M-2 and M-3, M-4, M-5
Example 6 except that M-6 and M-6 were used in the amounts listed in Table 5.
To obtain a nylon 66 reinforced resin composition. Test pieces were molded in the same manner as in Examples 6 to 11, and various performance evaluations were performed using the obtained test pieces. The results are shown in Table 5.

[0035]

[Table 5]

Example 17 10 kg of 12-aminododecanoic acid was mixed with 2 kg of water and M-1 in the amount shown in Table 6 with respect to 12-aminododecanoic acid. In a can, 12-aminododecanoic acid was polymerized in the presence of a swellable fluoromica-based mineral to obtain a reinforced nylon 12 resin composition. The polymerization reaction was performed as follows. That is, 180
While stirring at ℃, internal pressure is 3kg / cm ² to 20kg
/ Cm ² . After reaching the pressure, the temperature was gradually increased to 240 ° C., and while gradually releasing water vapor, the pressure was reduced finally, and polymerization was further performed for 2 hours. When the polymerization was completed, the reinforced nylon 12 resin composition was discharged and cut into pellets. The pellets were dried and used for forming test pieces. The molding of the test piece was performed using an injection molding machine at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C. Various performance evaluations were performed using the obtained test pieces. The results are shown in Table 6.

[0037]

[Table 6]

Comparative Examples 1 to 4 In the same manner as in Examples 1 to 5, except that M-1, montmorillonite and kaolin were used in place of M-1, M-2 and M-3 in the amounts shown in Table 7. A nylon 6 reinforced resin composition was obtained. A test piece was molded in the same manner as in Examples 1 to 5,
Various performance evaluations were performed using the obtained test pieces. The results are shown in Table 7.

[0039]

[Table 7]

Comparative Examples 5 to 8 In the same manner as in Examples 6 to 10 except that M-7, montmorillonite and kaolin were used in place of M-1, M-2 and M-3 in the amounts shown in Table 8. A nylon 66 reinforced resin composition was obtained. Various performance evaluations were performed using the obtained test pieces. Table 8 shows the results.

[0041]

[Table 8]

Comparative Example 9 Nylon 12 was obtained by polymerizing 12-aminododecanoic acid in the same manner as in Example 17 except that no swellable fluoromica-based mineral was used. Thereafter, the performance was evaluated in the same manner as in Example 17, and the results are shown in Table 6.

[0043]

According to the present invention, mechanical strength, heat resistance,
In addition, the dimensional stability is remarkably improved as compared with the polyamide alone, and a reinforced polyamide resin composition having a small impact on toughness and excellent impact strength can be obtained. Also suck
Reinforced polyamide with small mechanical strength and dimensional change due to water
A resin composition is obtained . Furthermore, if the fluorine mica-based mineral of the present invention is used, without performing the swelling treatment required when using a conventional clay mineral represented by montmorillonite, a method of blending this with a polyamide and melt-kneading it, or By directly blending with a monomer component for forming a polymer and polymerizing the same, a reinforced polyamide resin composition having excellent performance can be obtained.

Continuation of front page (56) References JP-A-6-80820 (JP, A) JP-A-62-74957 (JP, A) JP-A-55-38865 (JP, A) JP-A-51-109998 (JP, A) (A) JP-A-6-228435 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 77/00-77/12 C08G 69/00-69/50 C08K 3/34 -3/36

Claims (7)

(57) [Claims] 1. Polycaproamide (nylon 6) 100
Expressed by the following formula (1) with respect to the amount of monomer forming part by weight.
0.2 to 20 parts by weight of swellable fluoromica-based mineral
Reinforced polymer obtained by polymerizing monomers
A water-absorbing treatment (60 ° C., 95% R
A reinforced polyamide resin composition having a tensile strength value based on ASTM D638 of 470 kg / cm ² or more after 24 hours under H conditions). α (MF) · β (aMgF ₂ · bMgO) · γSiO ₂ (1) (where M represents sodium or lithium, α,
β, γ, a and b each represent a coefficient, and 0.1 ≦ α ≦
2, 2 ≦ β ≦ 3.5, 3 ≦ γ ≦ 4, 0 ≦ a ≦ 1, 0 ≦ b
≦ 1, a + b = 1. ) 2. The strengthening according to claim 1, wherein the swellable fluoromica-based mineral is obtained by heating a mixture of talc and sodium and / or lithium silicofluoride or fluoride. Polyamide resin composition. 3. The swellable fluoromica-based mineral is talc 90.
3. The reinforced polyamide resin according to claim 2, wherein the mixture is obtained by heating a mixture of about 65% by weight and 10% to 35% by weight of a mixture of sodium and / or lithium silicofluoride or fluoride. Composition. 4. Polyhexamethylene adipamide (Niro
66) 100 parts by weight and swelling represented by the formula (1)
Consisting of 0.2 to 20 parts by weight of a fluorinated mica-based mineral
A polyamide resin composition, which is subjected to a water absorption treatment (60 ° C., 9
ASTM D638 after 24 hours under conditions of 5% RH)
The tensile strength value based on 470 kg / cm ² or more
And a reinforced polyamide resin composition. 5. Polytetramethylene adipamide (Niro
46) 100 parts by weight and swelling represented by the above formula (1)
Consisting of 0.2 to 20 parts by weight of a fluorinated mica-based mineral
A polyamide resin composition, which is subjected to a water absorption treatment (60 ° C., 9
ASTM D638 after 24 hours under conditions of 5% RH)
The tensile strength value based on 470 kg / cm ² or more
And a reinforced polyamide resin composition. 6. Polydodecaneamide (nylon 12) 1
00 parts by weight and a swellable fluorine cloud represented by the above formula (1)
Reinforced polyamide consisting of 0.2 to 20 parts by weight of base mineral
A resin composition comprising a water-absorbing treatment (60 ° C., 95% RH)
After 24 hours under conditions) according to ASTM D638
Characterized in that the tensile strength value is 470 kg / cm ² or more
Reinforced polyamide resin composition. 7. Mono to form 100 parts by weight of polyamide
0.2-20 swellable fluoromica-based minerals
It features the polymerization of monomers in the presence of parts by weight.
A method for producing a reinforced polyamide resin composition .