JP2003261675A - Polyamide resin composition and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin composition which has the same surface appearance and toughness as with a non-reinforced polyamide and, simultaneously, excels in strength and rigidity, and its production method. <P>SOLUTION: The polyamide resin composition can be obtained by heating (A) a polyamide-forming monomer, (B) water, (C) an aluminum source, (D) a silica source, and (E) a basic metallic compound under pressurizing conditions to advance the polymerization of a polyamide and the hydrothermal synthesis reaction of an aluminum silicate compound in one and the same reaction vessel, and has the alumina silicate compound which is present in a dispersed state in the polyamide resin. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyamide resin composition and a method for producing the same. More specifically, it relates to a polyamide resin composition having the same surface appearance and toughness as non-reinforced polyamide, and excellent strength and rigidity, and a method for producing the same.

[0002]

2. Description of the Related Art Techniques for blending fibrous reinforcements such as glass fibers and mineral reinforcements such as calcium carbonate and talc are widely used to improve heat resistance and dimensional stability of polyamides such as nylon 6 and nylon 66. Are known. However, in the polyamide resin containing these reinforcing materials, since the reinforcing material dispersed in the polyamide resin is raised on the surface of the molded product and the light rays are diffusely reflected, it is inevitable that the appearance of the molded product is usually deteriorated. Further, the affinity between the polyamide and the reinforcing agent is low, and it is unavoidable that the toughness characteristic of the polyamide is significantly impaired.

Attempts have been made to use an aluminum compound or a silica compound as a reinforcing material. In this composition as well, although strength and rigidity can be improved as in a composition to which other reinforcing agents are added, it is reinforced with a polyamide. Since it has a low affinity with the agent, it has a drawback that the toughness is greatly reduced.
In order to strengthen the resin without affecting the appearance of the molded product and minimizing the deterioration of toughness, it is expected that the affinity between the polyamide and the reinforcing agent is increased.

Japanese Patent Application Laid-Open No. 11-199771 discloses a composition in which a polyamide raw material and an apatite raw material are blended and the polymerization of the polyamide and the synthesis of the apatite are carried out at the same time, whereby the interface of the apatite particles produced is in good contact with the polyamide. Disclosed is a reinforced polyamide composition which is obtained and in which deterioration in toughness is suppressed. However, in this composition, the particle size and shape of the apatite are not constant, and the effect of reinforcing the strength and rigidity of the polyamide composition is small. Therefore, it has been expected to develop a polyamide resin composition containing an inorganic filler which has a high affinity with polyamide and improves strength and rigidity.

[0005]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above problems of the prior art and to provide a reinforced polyamide resin composition excellent in strength, rigidity and toughness.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, obtain a polyamide resin composition by simultaneously advancing polyamide polymerization and hydrothermal synthesis of an alumina silicate compound. The inventors have found that the above-mentioned problems can be solved by this, and have reached the present invention.

That is, the present invention provides (1) (A) a polyamide-forming monomer, (B) water, (C) an aluminum source,
A polyamide resin composition obtained by heating (D) a silica source and (E) a basic metal compound under pressure conditions to allow a polymerization reaction of a polyamide and a hydrothermal synthesis reaction of an alumina silicate compound to proceed in the same reaction vessel. .

(2) The polyamide resin composition as described in 1 above, wherein the aluminum source (C) is aluminum hydroxide and / or aluminum oxide.

(3) The polyamide resin composition as described in 1 or 2 above, wherein the silica source (D) is silica sol and / or solid silica.

(4) The polyamide resin composition according to any one of 1 to 3 above, wherein (E) the basic metal compound is a hydroxide and / or oxide of an alkali metal element or an alkaline earth metal element. object.

(5) (A) a polyamide-forming monomer,
(B) water, (C) aluminum source, (D) silica source,
(E) A method for producing a polyamide resin composition, which comprises heating a basic metal compound under a pressure condition to allow a polymerization reaction of a polyamide and a hydrothermal synthesis reaction of an alumina silicate compound to proceed in the same reaction vessel. Is a thing that provides.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide-forming monomer (A) used in the present invention is a compound capable of producing a polyamide by polymerization, such as an amino acid, a lactam or a diamine and a dicarboxylic acid. Typical examples thereof include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and para-aminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, tetramethylenediamine and hexamethylenediamine. , 2-methylpentamethylenediamine, undecamethylenediamine, dodecamethylenediamine, (2,
2,4- or 2,4,4-) trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylylenediamine, paraxylylenediamine, 1,3-
Bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane,
Bis (4-aminocyclohexyl) methane, bis (3-
Methyl-4-aminocyclohexyl) methane, 2,2-
Aliphatic, alicyclic and aromatic diamines such as bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine and aminoethylpiperazine, and adipic acid, speric acid, azelaic acid, sebacic acid, dodecanedioic acid, Aliphatic, alicyclic, aromatic such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodiumsulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid Family dicarboxylic acids. It is also possible to use a known end-capping agent such as monocarboxylic acid or monoamine. In the present invention, the polyamide homopolymers or copolymers derived from these raw materials can be used alone or in the form of a mixture.

Of these polyamide-forming monomers,
ε-caprolactam, ω-laurolactam, 12-aminododecanoic acid, salts of tetramethylenediamine and adipic acid, salts of hexamethylenediamine and adipic acid, salts of hexamethylenediamine and sebacic acid, salts of hexamethylenediamine and terephthalic acid. It is preferable to use a salt of hexamethylenediamine and isophthalic acid, or a mixture containing them as a main component, ε-caprolactam, ω-laurolactam, a salt of hexamethylenediamine and adipic acid, a salt of hexamethylenediamine and sebacic acid, It is more preferable to use a salt of hexamethylenediamine and terephthalic acid, a salt of hexamethylenediamine and isophthalic acid, or a mixture containing these as the main components, such as ε-caprolactam, a salt of hexamethylenediamine and adipic acid, a salt of hexamethylenediamine and sebacine. acid Most preferred is the use of a salt or a mixture containing these as a main component.

The water (B) is an essential component for the hydrothermal synthesis of the alumina silicate compound and the formation of a finely dispersed state, which is a feature of the present invention, and ion exchange water or distilled water is usually used.

The aluminum source (C) is not particularly limited as long as it is a compound of aluminum, but aluminum hydroxide or aluminum oxide is preferably used.

The (D) silica source is not particularly limited as long as it is a compound of silicon, but silica sol or solid silica is preferably used.

The basic metal compound (E) is not particularly limited as long as it is a compound which shows basicity when dissolved in water and contains a metal element, but it is a hydroxide of an alkali metal element or an alkaline earth metal element. Objects and oxides are preferably used. Typical examples thereof include lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, lithium oxide, sodium oxide, potassium oxide, magnesium oxide, calcium oxide, barium oxide. .

The polyamide resin composition of the present invention comprises (A)
Polyamide-forming monomer, (B) water, (C) aluminum source, (D) silica source, and (E) basic metal compound are heated under pressure conditions to polymerize polyamide and hydrothermally synthesize alumina silicate compound. It can be produced by allowing the reaction to proceed in the same reaction vessel. As a result, a composition in which an alumina silicate compound is uniformly dispersed in a polyamide resin and which has an excellent affinity with polyamide, which cannot be achieved by the conventional technique, is achieved. Further, since the aluminum source, silica source and basic metal compound used as raw materials change in shape and size due to hydrothermal synthesis and are dispersed in the final polyamide resin composition, a fine particle size is not necessarily obtained at the raw material stage. It is not necessary to use the one that was set.

These raw materials are placed in a reaction vessel used for usual pressure polymerization of polyamide and heated under pressure.
Known additives to be added during the polymerization of polyamide, a polymerization catalyst typified by a phosphoric acid compound, an antioxidant, a dyeability improving agent, an inorganic additive such as titanium oxide or talc are features of the present invention. It can be used freely as long as it does not hinder the structure formation of the alumina silicate compound.

At the stage of starting the pressure polymerization reaction, it is preferable that the charged raw material is in the state of a uniform solution or slurry. For this reason, it is preferable that the raw material is heated in a conditioning tank separate from the polymerization reaction vessel, stirred by a homogenizer or irradiated with ultrasonic waves, and then transferred to the polymerization reaction vessel.

The composition of the charge is such that (A) polyamide-forming monomer is 100 parts by weight, and (B) water is 5 to 30 parts.
0 parts by weight, preferably 10 to 200 parts by weight, more preferably 20 to 100 parts by weight, and the (C) aluminum source is 0.
005 to 20 parts by weight, preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, and the (D) silica source is 0.005 to 20 parts by weight, preferably 0.01 to 1 part by weight.
0 parts by weight, more preferably 0.05 to 5 parts by weight (E) 0.001 to 10 parts by weight of the basic metal compound, preferably 0.005 to 5 parts by weight, more preferably 0.01 to 3 parts by weight. Is.

In the reaction, the pressure in the reaction vessel is kept constant by heating the charged composition and discharging water vapor from the reaction vessel so that the pressure becomes 1.5 to 3 MPa, preferably 1.7 to 2.0 MPa. After the step of keeping at, the steam is further released from the system to gradually reduce the pressure, and the maximum attainable temperature is 220 to 330 ° C, preferably 250 to 30 ° C.
The heating temperature is adjusted to be 0 ° C. Further, for the purpose of adjusting the polymerization degree of polyamide as necessary, 220 to
It is also possible to add a step of circulating an inert gas such as nitrogen under normal pressure or reducing the pressure while maintaining the temperature at 330 ° C., preferably 250 to 300 ° C. The above polymerization reaction may be carried out in a single reaction vessel or may be carried out by connecting a plurality of reaction vessels.

Finally, the polyamide resin composition is discharged from the reaction vessel. At this time, the shape of the polyamide resin composition is not particularly limited, but it is usually pelletized by a known pelletizing device such as a strand cutter so that the subsequent processing is convenient.

The polyamide resin composition thus obtained may be used to extract unreacted monomers and low-polymerization products with a solvent such as hot water, or to reduce the unreacted monomers and the like by reducing the pressure in the molten state. For post-treatment such as removal of molecular weight substances, and to further increase the degree of polymerization of polyamide,
It is also possible to use an apparatus for increasing the degree of polymerization in a molten state called solid phase polymerization or a finisher.

The polyamide resin composition of the present invention is characterized in that an alumina silicate compound is dispersed in the polyamide resin. Here, the alumina silicate compound may be a compound composed of an aluminum atom, a silicon atom, an oxygen atom and a metal atom. Of these, zeolite is preferred.

For the synthesis of alumina silicate, generally, for example, a hydrothermal method is used in which aluminum oxide, silica sol, sodium hydroxide, etc. are heated at about 200 ° C. under a high temperature and high pressure of 15 atm. The synthesis conditions and the polymerization conditions of the polyamide are very similar, and under the conditions of polymerizing the polyamide, the alumina silicate can be simultaneously synthesized.

In the present invention, a preferred example of the polyamide resin obtained as a result of the polymerization of the polyamide-forming monomer is a polyamide resin having a melting point of 200 ° C. or higher. By using such a polyamide, it is possible to obtain a molded product having excellent heat resistance and strength. Specific examples include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 6)
6), polycaproamide / polyhexamethylene adipamide copolymer (nylon 6/66), polytetramethylene adipamide (nylon 46), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon) 612), polyhexamethylene terephthalamide / polycaproamide copolymer (nylon 6
T / 6), polyhexamethylene terephthalamide / polydodecane amide copolymer (nylon 6T / 12), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polyhexamethylene adipamide / poly Hexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene adipamide / polyhexamethylene isophthalamide / polycaproamide copolymer (nylon 66
/ 6I / 6), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6T / 6
I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T
/ 6I), polyhexamethylene terephthalamide / poly (2-methylpentamethylene) terephthalamide copolymer (nylon 6T / M5T), polyhexamethylene terephthalamide / polyhexamethylene sebacamide / polycaproamide copolymer (nylon 6T / 610) /
6), polyhexamethylene terephthalamide / polydodecane amide / polyhexamethylene adipamide copolymer (nylon 6T / 12/66), polyhexamethylene terephthalamide / polydodecane amide / polyhexamethylene isophthalamide copolymer (nylon 6T / 12
/ 6I), polyxylylene adipamide (nylon XD
6) and mixtures or copolymers thereof.

Particularly preferred are nylon 6, nylon 66, nylon 6/66 copolymer, nylon 610 and nylon 66 / 6I / 6 copolymer,
And nylon 6T / 66 copolymer, nylon 6T
/ 6I copolymer, nylon 6T / 6 copolymer, nylon 6T / 12 copolymer, nylon 6T / 12/66
It is at least one polyamide selected from copolymers and copolymers having hexamethyleterephthalamide units such as nylon 6T / 12 / 6I copolymer. It is also practically preferable to use these polyamide resins as a mixture depending on the required properties such as moldability, heat resistance, toughness and surface property.

The degree of polymerization of the polyamide resin is not particularly limited as long as it can be subjected to ordinary molding processing, but as a relative viscosity measured at 25 ° C. in a 98% concentrated sulfuric acid solution of 1% by weight of the polyamide resin, it is 2 Those in the range of to 4 are preferable.

The terminal amine of the polyamide resin used in the present invention
There is no particular limitation on the concentration of the radical, but 2 × 10^-Five~ 15x
10^-FiveIt is preferably mol / g, more preferably
Is 3 × 10^-Five~ 12 × 10^-Five, Mol / g, especially preferred
Kuha 5 × 10^-Five~ 10 x 10 ^-FiveIt is mol / g.

In the polyamide resin composition of the present invention, other components such as an antioxidant and a heat stabilizer (hindered phenol type, hydroquinone type, phosphite type and substitution products thereof) are used as long as the effects of the present invention are not impaired. Etc.), weathering agents (resorcinol-based, salicylate-based, benzotriazole-based, benzophenone-based, hindered amine-based, etc.),
Release agents and lubricants (montanic acid and its metal salts, their esters, their half esters, stearyl alcohol, stearamide, various bisamides, bisurea, polyethylene wax, etc.), pigments (cadmium sulfide, phthalocyanine, metallic pigments, etc.), dyes ( Nigrosine, etc.), crystal nucleating agent (talc, kaolin, clay, etc.), plasticizer (octyl p-oxybenzoate, N-butylbenzenesulfonamide, etc.), antistatic agent (alkylsulfate type anionic antistatic agent, quaternary) Ammonium salt-type cationic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, betaine amphoteric antistatic agents, etc., flame retardants (red phosphorus, melamine cyanurate, ammonium polyphosphate, bromine) Polystyrene, brominated P
PO, brominated PC, brominated epoxy resin or a combination of these brominated flame retardants and antimony trioxide), inorganic filler, other polymers (polyester, polycarbonate, polyphenylene ether, polyphenylene sulfide, polyether sulfone, ABS resin, S
AN resin, polystyrene, acrylic resin, polyethylene, polypropylene, SBS, SEBS, various elastomers, etc.) can be added.

The thermoplastic resin composition of the present invention is extruded,
A molded product can be easily obtained by a usual processing method such as injection molding. The obtained molded product has the same surface appearance and tensile elongation as non-reinforced polyamide resin, and is excellent in dimensional stability and rigidity, and is suitable for various engineering parts and structural materials.

[0033]

The present invention will be described in detail below with reference to examples, but the gist of the present invention is not limited to the following examples.

Evaluation Items and Measuring Method Filler Component: Wide-angle X-ray diffraction measurement was performed on the molded piece used in the tensile test, and the filler was identified from the diffraction peak pattern.

Ash content of filler: 10 g of the polyamide resin composition was ashed in an electric furnace at 600 ° C. for 5 hours, and the weight of the inorganic ash was measured and quantified.

Tensile test: Measured according to ASTM D638. The test piece used was ASTM 1 with a thickness of 1/8 inch.
No. test piece. The measurement was carried out at 23 ° C.

Bending test: Measured according to ASTM D790. The test pieces used were 1/2 inch x 5 inch x 1 /
It is a 4-inch rod-shaped test piece. The measurement was performed at 23 ° C and 90 ° C.

Surface appearance: 80 × 80 × 3 (mm) mirror-polished square plate was injection-molded, and the sharpness of the reflection image of the fluorescent lamp was visually observed on the surface of the obtained square plate and evaluated as follows. . ⊚: Glossy, the reflected image of the fluorescent lamp is clearly observed. ◯: Although glossy, the reflection image of the fluorescent lamp is slightly unclearly observed. Δ: A little gloss, but no reflection image of a fluorescent lamp can be observed. X: There is no gloss and no reflection image of the fluorescent lamp can be observed.

Example 1 An equimolar salt of hexamethylenediamine and adipic acid (AH
Salt) 100 parts by weight, ion-exchanged water 70 parts by weight, aluminum hydroxide (reagent first grade) 0.6 parts by weight, 30 wt% silica sol ("LUDOX HS-30" manufactured by DuPont) 2.
0 parts by weight and 0.1 parts by weight of sodium hydroxide (first grade reagent) are heated to 80 ° C. in a control tank and stirred with a homogenizer,
After making it into a uniform slurry, it was charged into an autoclave. The heater temperature was set to 295 ° C. and heating was performed, and when the internal pressure of the can reached 1.7 MPa, the internal pressure was kept constant. After holding for 2 hours in this state, gradually return to normal pressure over 1 hour,
Further, the polymerization was completed by reacting at 280 ° C. for 5 minutes under a reduced pressure of −160 mmHg.

The polyamide resin composition after polymerization was discharged from an autoclave in a gut form and pelletized. The obtained pellets were dried and then molded with an injection molding machine having a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C., and evaluated. Other evaluation results are shown in Table 1.

Example 2 Polymerization, molding and evaluation were carried out in the same manner as in Example 1 except that sodium hydroxide was changed to calcium oxide. The results are shown in Table 1.
Shown in.

Example 3 Polymerization, molding and evaluation were carried out in the same manner as in Example 1 except that the addition amounts of aluminum hydroxide, 30 wt% silica sol and sodium hydroxide were changed. The results are shown in Table 1.

Example 4 Polymerization, molding and evaluation were carried out in the same manner as in Example 2 except that the addition amounts of aluminum hydroxide, 30 wt% silica sol and calcium oxide were changed. The results are shown in Table 1.

Example 5 Polymerization, molding and evaluation were carried out in the same manner as in Example 1 except that aluminum hydroxide was changed to aluminum oxide. The results are shown in Table 1.

Example 6 Polymerization, molding and evaluation were carried out in the same manner as in Example 1 except that 30 wt% silica sol was changed to 0.6 part by weight of solid silica. The results are shown in Table 1.

Comparative Example 1 1.2 parts by weight of aluminum hydroxide as a raw material for the filler,
Polymerization, molding and evaluation were carried out in the same manner as in Example 1 except that 4.0 parts by weight of 30 wt% silica sol was used. The results are shown in Table 1.
Shown in.

Comparative Example 2 Polymerization, molding and evaluation were carried out in the same manner as in Example 1 except that 2.6 parts by weight of calcium monohydrogen phosphate was used as the raw material of the filler. The results are shown in Table 1.

Comparative Example 3 Polymerization, molding and evaluation were carried out in the same manner as in Example 1 except that 2.6 parts by weight of Na alumina silicate was used as the raw material of the filler. The results are shown in Table 1.

Comparative Example 4 Polymerization, molding and evaluation were carried out in the same manner as in Example 1 except that no filler was added. The results are shown in Table 1.

[0050]

[Table 1]

[0051]

INDUSTRIAL APPLICABILITY The polyamide resin composition of the present invention can be obtained by simultaneously advancing the polymerization of polyamide and the hydrothermal synthesis of an alumina silicate compound, and has the same surface appearance and tensile elongation as those of non-reinforced polyamide resin. While doing
Excellent tensile strength and flexural modulus. Therefore, it can be widely used as a material for which surface appearance and toughness are required and strength and rigidity are required, for example, materials for automobile parts, building materials, furniture parts, and electrical parts.

Continued front page    F-term (reference) 4J001 DA01 DB01 DB02 DC11 DC12                       DC14 DD13 EA02 EA06 EA08                       EA13 EA14 EA15 EB02 EB03                       EB06 EB08 EB09 EB16 EB26                       EB28 EB33 EB34 EB36 EB37                       EB45 EC02 EC03 EC07 EC08                       EC09 EC13 EC14 EC16 EC27                       EC28 EC29 EC43 EC44 EC47                       EC48 EE01E EE02E EE08E                       EE09E EE16D EE18E EE25E                       EE27E EE28E EE30E EE35E                       EE36E EE43E EE53E EE58E                       EE64E EE72E EE74E GA12                       GA15 GB01 GB02 GB03 GB16                       GD01 GD02 HA01 JA01 JA05                       JA07 JB02 JB14 JB23 JB27                 4J002 CL011 CL021 CL031 CL051                       DE058 DE078 DE088 DE146                       DJ017 GL00 GN00

Claims (5)

[Claims] 1. A polyamide-forming monomer (A), (B)
Water, (C) aluminum source, (D) silica source, and (E) basic metal compound are heated under pressure conditions, and the polymerization reaction of the polyamide and the hydrothermal synthesis reaction of the alumina silicate compound proceed in the same reaction vessel. A polyamide resin composition thus obtained. 2. The polyamide resin composition according to claim 1, wherein the aluminum source (C) is aluminum hydroxide and / or aluminum oxide. 3. The silica source (D) is silica sol and / or solid silica, wherein
The polyamide resin composition described. 4. The polyamide resin composition according to claim 1, wherein (E) the basic metal compound is a hydroxide and / or oxide of an alkali metal element or an alkaline earth metal element. object. 5. (A) Polyamide-forming monomer, (B)
Water, (C) aluminum source, (D) silica source, and (E) basic metal compound are heated under pressure conditions, and the polymerization reaction of the polyamide and the hydrothermal synthesis reaction of the alumina silicate compound proceed in the same reaction vessel. A method for producing a polyamide resin composition, comprising: