JP2001288360A - Polyamide resin composition and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition in which a phyllosilicate is dispersed in a polyamide resin in a molecular level, in which a specific compound is further chemically bound in the dispersion, and which has excellent strength, rigidity, melt stability and dyeability, and to provide a method for producing the same. SOLUTION: This polyamide resin composition characterized by comprising 100 pts.wt. of a polyamide resin and 0.5 to 50 pts.wt. of a phyllosilicate dispersed in the polyamide in a molecular level and further containing a specific compound in a chemically bound state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyamide resin composition which is excellent in heat resistance, strength and rigidity, has good stability during melt molding, and hardly causes color unevenness during dyeing, and a method for producing the same.

[0002]

2. Description of the Related Art A polyamide resin composition having improved heat resistance, strength / rigidity, and gas barrier properties in which a silicate layer of a layered silicate is uniformly dispersed in a polyamide resin has been known for a long time. JP-A-62-74975 discloses a polyamide resin composition comprising a polyamide resin and montmorillonite, and JP-A-6-248176 discloses a polyamide resin composition comprising a polyamide resin and a swellable fluoromica-based mineral. Proposed.

[0003] These resin compositions are used for various injection molded articles, films, fibers and the like, utilizing the above-mentioned excellent properties. In such use, it is necessary to heat and re-melt the resin composition obtained in the form of pellets or the like to mold it into a desired shape. There is a problem that oligomers are regenerated and mixed as foreign matter into the resin composition to cause deterioration in physical properties, or adhere to molds and nozzles to contaminate them, thereby lowering operability during production. Further, at the time of remelting, for example, at the time of injection molding, there is a problem that the viscosity of the polyamide resin is increased in the cylinder, which causes molding defects such as warpage of the molded product.

Furthermore, these conventional resin compositions are not suitable for dyeing the surface of a molded article or the like into a desired color tone because of the low color transfer of the dye to the surface resin portion of the molded article. The entire surface of the resin molding does not stain uniformly,
There was a problem that so-called uneven dyeing easily occurred.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and is excellent in heat resistance and strength / rigidity, and at the same time, produces less monomers and oligomers at the time of melt molding and stabilizes the viscosity. It is intended to provide a polyamide resin composition which is produced and is less likely to cause color unevenness during dyeing, and a method for producing the same.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, during the polymerization, a layered silicate and a specific compound were blended into a monomer material to obtain a specific chemical structure. It has been found that this object can be achieved by imparting the following, and the present invention has been achieved.

That is, the gist of the present invention is as follows. (1) A resin composition comprising 100 parts by mass of a polyamide resin and 0.5 to 50 parts by mass of a layered silicate dispersed at a molecular level in the polyamide resin contains at least one compound represented by the following formulas 1 to 5: Is present in a chemically bonded state.

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Embedded image (2) With respect to the amount of the monomer forming 100 parts by mass of the polyamide resin, the monomer is polymerized in a state where 0.5 to 50 parts by mass of the layered silicate and at least one compound represented by the above formulas 1 to 5 are present The method for producing the polyamide resin composition according to the above (1).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

In the resin composition of the present invention, it is necessary that the layered silicate is dispersed at a molecular level in the polyamide resin. Here, “dispersed at the molecular level” means a state in which the layered silicates maintain an interlayer distance of 20 ° or more on average when dispersed in the polyamide resin matrix. Here, the interlayer distance refers to the distance between the centers of gravity of the flat layers of the layered silicate layer, and the dispersed state means that each layered silicate layer has an average overlap of 5 layers. A state in which at least 50% or more of the following multilayers are dispersed in parallel or randomly, or in a state where both parallel and random are mixed, without forming a lump. Specifically, it can be confirmed from the absence of a layered silicate lump by transmission electron micrograph photography observation.

The polyamide resin of the present invention needs to have at least one of the compounds represented by the above formulas 1 to 5 in a chemically bonded state. The compound represented by is preferable because the properties can be effectively improved.

The state in which the compound represented by the above formula 1 is chemically bonded is specifically defined by the following formula 6

Embedded image At the terminal of the polymer chain.

The state in which the compound represented by the above formula 2 is chemically bonded is, specifically, an imino bond represented by the following formula 7 and / or an amide bond represented by the following formula 8: It has one in the polymer chain or at the terminal.

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The state in which the compound represented by the above formula 3 is chemically bonded is, specifically, an amine group represented by the following formula 9 and / or a diamine group represented by the following formula 10: It has one in the polymer chain or at the terminal.

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The state where the compound represented by the above formula 4 is chemically bonded is specifically defined by the following formula 11

Embedded image At the terminal of the polymer chain.

The state in which the compound represented by the above formula 5 is chemically bonded is specifically defined by the following formula 12

Embedded image In the polymer chain.

The polyamide resin of the present invention is formed from an aminocarboxylic acid, a lactam or a diamine and a dicarboxylic acid (including a salt comprising a pair thereof).
It means a polymer having an amide bond in the main chain. Specifically, polycaproamide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodeca Amide (nylon 612), polyundecamethylene adipamide (nylon 116), polyundecane amide (nylon 1
1), polydodecaneamide (nylon 12), polytrimethylhexamethylene terephthalamide (nylon TMH
T), polyhexamethylene isophthalamide (nylon 6
I), polyhexamethylene terephthal / isophthalamide (nylon 6T / 6I), polybis (4-aminocyclohexyl) methandodecamide (nylon PACM12), polybis (3-methyl-4-aminocyclohexyl) methandodecamide (nylon dimethyl PACM12) ), Polymethaxylylene adipamide (nylon MXD6), polynonamethylene terephthalamide (nylon 9T), polyundecamethylene terephthalamide (nylon 11T), polyundecamethylene hexahydroterephthalamide [nylon 11T (H)]
Alternatively, these are polyamides or mixed polyamides, preferably nylon 6 or nylon 66 or a copolymerized polyamide thereof, more preferably nylon 6 or a copolymerized polyamide thereof.

The relative viscosity of the above polyamide resin is a value determined in 96 mass% sulfuric acid at a temperature of 25 ° C. and a concentration of 1 g / dl.
Those in the range of 1.5 to 5.0 are preferable, and those in the range of 2.0 to 4.0 are more preferable. Those having a relative viscosity of less than 1.5 have poor mechanical strength when formed into a molded product. On the other hand, when the relative viscosity exceeds 5.0, the moldability is significantly reduced.

The layered silicate in the present invention has a structure comprising a negatively charged layer mainly composed of silicate and a positive charge (ion) interposed between the layers.

Preferred examples of such a layered silicate include:
Smectites (eg, montmorillonite, beidellite, saponite, hectorite, sauconite), vermiculites (eg, vermiculite), mica (eg, fluoromica, muscovite, paragonite, phlogopite, biotite, lepidrite), brittle mica (E.g., margarite, clintite, anandite), chlorite (e.g., dombasite, sudoite, couquaite, clinochlore, chamosite, nimmite), and the like, with fluorine mica or montmorillonite being more preferred.
Among fluorine mica, swellable fluorine mica is particularly preferred in terms of whiteness.

These layered silicates may be produced naturally or artificially synthesized or modified. They may be treated with an organic substance such as an onium salt.However, the swellable fluoromica described below has excellent dispersibility when added during polymerization in the presence of a polyamide monomer. It can be used well without the treatment of organic substances.

Among the above layered silicates, the swellable fluoromica is represented by the following formula and can be easily synthesized. α (MF) · β (aMgF ₂ · bMgO) · γSiO ₂ (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. Note that this formula shows an ideal composition ratio, and does not need to exactly match.

As a method for producing such swellable fluorine mica, for example, silicon oxide, magnesium oxide and various fluorides are mixed, and the mixture is heated in an electric furnace or a gas furnace at a temperature of 1400 to 1500 ° C. There is a so-called melting method of completely melting and growing fluorine mica in a reaction vessel during the cooling process.

Further, there is a method of using talc as a starting material and intercalating an alkali metal ion into the starting material to obtain swellable fluoromica (Japanese Patent Laid-Open No. 2-149415). In this method, talc is mixed with an alkali silicate or an alkali fluoride, and is mixed in a magnetic crucible for about 700 to 12 hours.
Heat treatment at 00 ° C. for a short time makes it possible to obtain swellable fluoromica.

At this time, the amount of alkali silicate or alkali fluoride to be mixed with talc is 10 to 35% of the whole mixture.
It is preferable to be within the range of mass%, and if it is out of this range, the yield of swellable fluoromica decreases, which is not preferable.

The swellable fluorine mica can be controlled in particle size by means such as pulverization or classification, or removal of coarse particles. Preferred average particle size range is 0.5-2
0 μm, and particularly preferably 1 to 10 μm. Further, purification by removing non-swelling trace components can be performed by a water treatment.

Among the above-mentioned layered silicates, montmorillonite is represented by the following formula and can be obtained by purifying a naturally occurring product. Na _x Si ₄ (Al _2−x Mg _x ) O ₁₀ (OH) ₂ .nH ₂ O (where x is 0.25 to 0.60 and n is an integer of 0 or more). Groups represent an ideal composition ratio and do not need to be exactly the same. In particular, as described below, ion-exchangeable cations other than sodium may be present as impurities, and this case can also be used in the present invention. Montmorillonite also includes the same type ion substitutes of magnesia montmorillonite, iron montmorillonite, and iron magnesia montmorillonite represented by the following formula group, and these may be used. Na _x Si ₄ (Al _1.67-x Mg _{0.5 + x} ) O ₁₀ (OH) ₂ .n
H ₂ O Na _x Si ₄ (Fe (III) _2-x Mg _x ) O ₁₀ (OH) ₂ .nH
₂ O Na _x Si ₄ (Fe (III) _1.67-x Mg _{0.5 + x} ) O ₁₀ (OH)
₂ · nH ₂ O (where x is 0.25 to 0.60, and n is an integer of 0 or more.)

In general, montmorillonite may have ion-exchangeable cations such as calcium between its layers in addition to sodium. However, ion-exchange treatment or the like replaces ion-exchangeable cations other than sodium existing between the layers with sodium. You may. Purification for removing non-swelling components can also be performed by water treatment.

Next, a method for producing the polyamide resin composition of the present invention will be described. That is, in the method of the present invention, it is necessary to polymerize the starting monomer in the presence of the layered silicate and at least one compound represented by the above formulas 1 to 5. At this time, the compounding amount of the layered silicate is 0.5 to 100 parts by mass of the monomer forming the polyamide resin.
It is necessary to use 50 parts by mass, and preferably 1 to 15 parts by mass, more preferably 1.5 to 5 parts by mass in order not to impair the toughness of the polyamide resin. If the amount is less than 0.5 parts by mass, the reinforcing effect of the layered silicate on the polyamide resin is small, and sufficient heat resistance, strength and rigidity cannot be obtained. On the other hand, if the amount exceeds 50 parts by mass, the polymerization of the polyamide resin tends to be difficult, which is not preferable.

Preferred examples of the compound represented by the above formula 1 include 4-amino-2,2,6,6-tetramethylpiperidine and 4-butylamino-2,2,6,6-tetramethylpiperidine And the like. The compounding amount of these compounds is preferably 0.2 to 10 mmol, more preferably 0.5 to 5 mmol, per 1 mol of the monomer forming the polyamide resin. If the amount is less than 0.2 mmol, satisfactory thermal stabilization cannot be obtained, and if it exceeds 10 mmol, the molar balance between the amino group and the carboxyl group of the raw material is lost, so the degree of polymerization of the polyamide resin is reduced. It tends to decrease.

Specific examples of the compound represented by the above formula 2 include 2,2,6,6-tetramethylpiperidone, N-methyl-2,2,
Examples thereof include 6,6-tetramethylpiperidone and N-benzyl-2,2,6,6-tetramethylpiperidone, among which 2,2,6,6-tetramethylpiperidone is preferable. The compounding amount of these compounds is preferably 1 to 20 mmol, more preferably 2 to 10 mmol, per 1 mol of the monomer forming the polyamide resin. If the compounding amount is less than 1 mmol, satisfactory thermal stabilization cannot be obtained. Conversely, if the compounding amount exceeds 20 mmol, the molar balance between the amino group and the carboxyl group of the raw material is lost, so that the degree of polymerization of the polyamide resin is reduced. It tends to decrease.

Preferred specific examples of the compound represented by the above formula 3 include N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and the like. The compounding amount of these compounds is preferably 0.1 to 5 mmol, more preferably 0.2 to 3 mmol, per 1 mol of the monomer forming the polyamide resin. If the amount is less than 0.1 mmol, satisfactory thermal stabilization cannot be obtained, while if it exceeds 5 mmol, the molar balance between the amino group and the carboxyl group of the raw material is lost, so that the degree of polymerization of the polyamide resin is reduced. It tends to decrease.

The compound represented by the above formula (4) refers to a compound in which a nitrogen atom of a pyridine ring is located at the 1-position and is located at any position other than the 1-position, preferably at any of the 3- or 4-position.
Or a structure having one carboxyl group across a linear alkylene group having 1 to 4 carbon atoms, and a hydrogen atom, a 1 to 1 carbon atom at the other position of the pyridine ring. It has 4 linear or branched alkyl groups or a benzyl group. Specifically, isonicotinic acid (4-pyridinemonocarboxylic acid), nicotinic acid (3-pyridinemonocarboxylic acid), 3-pyridylacetic acid,
Pyridyl acetic acid and the like can be mentioned, among which isonicotinic acid is preferable. The compounding amount of these compounds is preferably 1 to 20 mmol, more preferably 2 to 10 mmol, per 1 mol of the monomer forming the polyamide resin. If the compounding amount is less than 1 mmol, satisfactory thermal stabilization cannot be obtained. Conversely, if the compounding amount exceeds 20 mmol, the molar balance between the amino group and the carboxyl group of the raw material is lost, so that the degree of polymerization of the polyamide resin is reduced. It tends to decrease.

The compound represented by the above formula 5 is defined as two positions at any position other than the 1-position with the nitrogen atom of the pyridine ring as the 1-position, preferably at any position other than the 1-position which is not adjacent to each other. A structure having two carboxyl groups, one at each of two positions, and a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a benzyl group at another position of the pyridine ring. belongs to. In particular,
Dinicotinic acid (3,5-pyridinedicarboxylic acid), lutidic acid (2,4-pyridinedicarboxylic acid), isosincomomeronic acid (2,5-pyridinedicarboxylic acid), 2,6-dimethyl-3,5-pyridinedicarboxylic acid Acid, 4-methyldipicolinic acid (4-methyl
-2,6-pyridinedicarboxylic acid). The compounding amount of these compounds is preferably 0.5 to 10 mmol, more preferably 1 to 5 mmol, per 1 mol of the monomer forming the polyamide resin. If the amount is less than 0.5 mmol, satisfactory thermal stabilization cannot be obtained, and if the amount exceeds 10 mmol, the molar balance between the amino group and the carboxyl group of the raw material is lost, so the degree of polymerization of the polyamide resin is reduced. It tends to decrease.

The compounds represented by the formulas 1 to 5 may be used in combination of two or more. In this case, the compounding amount may be compounded in a range of a preferable compounding amount of each compound, but it is preferable that the total of compounding amounts of each compound does not exceed 30 mmol per 1 mol of a monomer forming the polyamide resin, More preferably, it is 0.5 to 20 mmol. If the amount exceeds 30 mmol, the molar balance between the amino group and the carboxyl group of the raw material is lost, and the degree of polymerization of the polyamide resin tends to decrease.

Among the compounds represented by the above formulas 1 to 5, especially the compounds represented by the formulas 1 to 3, the effect of improving the weather resistance of the polyamide resin, that is, the change in color tone when used outdoors for a long period of time. Excellent resistance improvement effect.

The compounds represented by the formulas 1 to 5 can also be used in combination with at least one conventional chain control agent. Specific examples of the chain controller include monocarboxylic acids such as acetic acid, benzoic acid, and propionic acid; dicarboxylic acids such as adipic acid, terephthalic acid, and isophthalic acid; ethylamine, n-propylamine, isopropylamine, and n-butylamine. Monoamine, tetramethylenediamine, hexamethylenediamine, m-xylylenediamine, p-xylylenediamine and the like. The type of chain control agent, its combination and the amount used are determined by the content of amino terminal groups and the melt stability desired as the final product.

In the present invention, in order to introduce the compounds represented by the formulas 1 to 5 into the polyamide resin composition in a chemically bonded state, the compound and the layered silicate are required. It is necessary to polymerize the monomers forming the polyamide in the presence of As a method for polymerizing the monomer, a known method can be adopted. Among them, a melt polycondensation method is preferable regardless of a batch type or a continuous type. Specifically, necessary raw materials are charged into an autoclave, and in the presence of an initiator such as water, a temperature of 240 to 300 ° C. and a pressure of 2 to 3 are used.
It may be performed at 0 kg / cm ² for 1 to 15 hours. By adopting such temperature, pressure, and time conditions, the chemical structure represented by Formulas 6 to 12 can be introduced into the polyamide resin composition without performing any other special treatment. Disperse in polyamide resin at molecular level. Depending on the polymerization conditions selected, some of the compounds of the formulas 1 to 5 may remain in the polyamide resin composition in an unreacted state, but the residual amount is usually a trace amount, and the residue is It does not hinder the effects of the present invention. When nylon 6 is used as the matrix, it is preferable to polymerize at a temperature of 250 to 280 ° C., a pressure of 5 to 20 kg / cm ² , and a time of 3 to 5 hours. In order to remove the polyamide monomer remaining in the polyamide resin composition after polymerization, a scouring step using hot water is preferably performed. In this case, the treatment is preferably performed in hot water at 90 to 100 ° C. for 5 hours or more.
Through the scouring step, even if trace amounts of the compounds of formulas 1 to 5 remain in the polyamide resin composition after polymerization, they are extracted and removed, and as a result, the residual amount can be further reduced.

Further, a step of mixing the layered silicate and the monomer in a dispersion medium such as water, methanol, ethanol or ethylene glycol may be provided. By this step, dispersion of the layered silicate in the monomer can be promoted. The temperature condition may be room temperature or, if necessary, higher than room temperature and lower than the boiling point of the dispersion medium. In the mixing, a means for increasing the stirring efficiency, a homomixer, an ultrasonic disperser, a high-pressure disperser, or the like may be used. In these steps, all or part of the amount of the compound represented by Formulas 1 to 5 may be added.

The polyamide resin composition of the present invention contains a heat stabilizer, an antioxidant, a reinforcing material, a pigment, a deterioration inhibitor, a weathering agent, a flame retardant, a plasticizer, a release agent, as long as the properties are not significantly impaired. Molding agents, lubricants and the like may be added, and these are added at the time of polymerization or at the time of melt-kneading or melt-molding the obtained polyamide resin composition.

Examples of the heat stabilizer, antioxidant, and deterioration inhibitor include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, halides of alkali metals, and mixtures thereof.

As a reinforcing material, for example, clay, talc,
Calcium carbonate, zinc carbonate, wollastonite, silica,
Alumina, magnesium oxide, calcium silicate, sodium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, zinc oxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate whisker, boron nitride , Graphite, fiberglass,
And carbon fiber.

Further, a small amount of another thermoplastic polymer may be mixed in the polyamide resin composition as long as the effects of the present invention are not impaired. It is added during melt molding. Such thermoplastic polymers include, for example, nylon 46, nylon 66, nylon 610, nylon 61
2, nylon 116, nylon 11, nylon 12, nylon T
MHT, nylon 6I, nylon 6T / 6I, nylon PACM12,
Nylon dimethyl PACM12, nylon MXD6, nylon 9T,
Nylon 11T, Nylon 11T (H), etc. In addition, polybutadiene, butadiene / styrene copolymer,
Elastomers such as acrylic rubber, ethylene / propylene copolymer, ethylene / propylene / diene copolymer, natural rubber, chlorinated butyl rubber, chlorinated polyethylene, or acid-modified products of these with maleic anhydride, styrene / maleic anhydride copolymer Polymer, styrene / phenylmaleimide copolymer, polyethylene, polypropylene, butadiene / acrylonitrile copolymer, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate,
Examples include polyacetal, polyvinylidene fluoride, polysulfone, polyphenylene sulfide, polyether sulfone, phenoxy resin, polyphenylene ether, polymethyl methacrylate, polyether ketone, polycarbonate, polytetrafluoroethylene, and polyarylate. These thermoplastic polymers may be layered silicates dispersed at the molecular level and reinforced.

The polyamide resin composition of the present invention can be formed into a desired molded article by a usual molding method. For example, various molded articles can be formed by a hot melt molding method such as injection molding, extrusion molding, and blow molding. In these cases, the effects of the present invention reduce the regeneration of monomers and oligomers at the time of melt molding. The problem of adhesion and soiling, which reduces operability during production, has been solved, and stable quality and operability can be obtained.

Since the molded article obtained by using the polyamide resin composition of the present invention is less likely to cause color unevenness during dyeing, the molded article is particularly suitable for various uses in which the surface is colored. I have.

The above-mentioned molded articles are used for clothing such as fasteners and buttons, office equipment parts such as chairs and desks, OA such as personal computers, printers, vacuum cleaners, washing machines, electric pots and the like.
It can be suitably used for applications such as exterior parts of equipment and home appliances, toys such as plastic model (registered trademark), hairbrushes, eyeglass frames, daily necessities such as accessories, and in particular, compounds of formulas 1 to 3. The polyamide resin composition used is preferably used outdoors, such as artificial grass, various display plates, or wheels, light covers, door mirror stays, etc. can do. However, the uses of the above-mentioned molded articles are not limited to these, and use the excellent mechanical strength, elastic modulus, heat resistance, dyeability, weather resistance, etc., which are the characteristics of the polyamide resin composition of the present invention. Can be widely used in fields where

The polyamide resin composition of the present invention
The filament can be melt-spun into a filament by an ordinary method. Further, the polyamide resin composition of the present invention can be formed into a film or a sheet by a tubular method, a T-die method, a solution casting method or the like. Also in these cases, the effects of the present invention can reduce the regeneration of monomers and oligomers at the time of spinning or at the time of film formation, and can improve operation stability. The obtained film has excellent elongation properties and gas barrier properties, and thus can be suitably used as a packaging film.

[0047]

Next, the present invention will be described more specifically with reference to examples. In addition, the measuring method of the raw material and physical property test used in the Examples and Comparative Examples is as follows. 1. Raw material Layered silicate: Swellable synthetic fluoromica ME-100 (average particle size: 6 μm) manufactured by Corp Chemical Co., Ltd. Montmorillonite Kunipia-F (average particle size: 1 μm) manufactured by Kunimine Industries Co., Ltd. 4-amino-2,2,6,6 -Tetramethylpiperidine: manufactured by Huls 4-butylamino-2,2,6,6-tetramethylpiperidine: manufactured by Huls 2,2,6,6-tetramethylpiperidone monohydrate: manufactured by Tokyo Chemical Industry N , N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine: Huls Inc. Isonicotinic acid: Tokyo Chemical Co., Ltd. Dinicotinic acid: Tokyo Chemical Co., Ltd.

2. Measurement method (a) Relative viscosity 96% sulfuric acid is used as a solvent to prepare a concentration of 1 g / dl,
It measured at 25 degreeC using the Ubbelohde viscometer. (b) Viscosity stability during melting The polyamide resin composition pellets were placed in a glass tube at 0.01 To.
After melting at 250 ° C. for 5 hours or less, relative viscosity before and after that was measured by the method described in (a), and the amount of change was used as an index of viscosity stability during melting. (c) Amino end group concentration 0.5 g of polyamide resin composition pellets and m-cresol
20 ml was placed in a flask, dissolved at 60 ° C., cooled to room temperature, and titrated with a 0.1N aqueous solution of p-toluenesulfonic acid. (D) carboxyl end group concentration 0.2 g of pellets of polyamide resin composition and 10 ml of benzyl alcohol were placed in a flask, and dissolved at room temperature.
Was determined by titration with a potassium hydroxide-benzyl alcohol solution. (e) Monomer production amount Pellets of polyamide resin composition, 0.01 Torr or less, 25
After melting at 0 ° C. for 5 hours, the mixture was freeze-ground in liquid nitrogen.
Next, 0.5 g of the ground material was dispersed in 10 ml of distilled water,
After extraction with hot water at 5 ° C. for 5 hours, the amount of monomer in the extract was quantified using a high-performance liquid chromatograph (600E, manufactured by Waters Corporation) using the filtrate filtered with a filter having a pore size of 0.45 μm as a measurement material. The high-performance liquid chromatograph measurement was performed under the following conditions. Column: C18 (Waters Inc., length 250 mm, inner diameter
Eluent: methanol / water = 35/65 (volume ratio) Flow rate: 0.7 ml / min Column temperature: room temperature Detector: UV210 nm (f) Dispersibility of layered silicate in polyamide resin composition For bending measurement A sample cut into small pieces from the test piece was embedded in epoxy resin, cut into ultrathin sections with a diamond knife, and photographed with a transmission electron microscope (JEM-200CX, JEOL, acceleration voltage 100 kV). From the micrograph observation, the dispersibility was evaluated by obtaining the approximate size of the silicate layer of the layered silicate dispersed in the polyamide matrix. (g) Dyeing property Dyeing with three primary colors (red, blue, yellow) acid dye,
The degree of staining was visually observed and evaluated. Suminol Milling Red RS manufactured by Sumitomo Chemical Co., Ltd. as the red dye, Nylosan Blue N-GFL manufactured by SANDOZ as the blue dye, Nylosan Yellow N-3RL manufactured by SANDOZ as the yellow dye. % Dye solution (4
8% by weight of acetic acid adjusted to 0.3 ml / liter to adjust the acidity of the dyeing liquor) to perform a dyeing test at a temperature of 80 to 90 ° C. The evaluation was performed based on the number of pieces. (h) Tensile strength of test piece Measured based on ASTM D-638. (i) Flexural modulus of test specimen Measured based on ASTM D-790. (j) Deflection temperature under load of test piece Measured under a load of 1.86 MPa based on ASTM D-648. (k) Weather resistance Based on JIS-K7350-4, using a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd., WEL-SUN-HC type), a black panel temperature of 63 ° C, irradiation for 2 hours and a 18 minute rain cycle Under the conditions, the weather resistance acceleration test was repeated for 2000 hours, and the difference from the color tone measured before the test was evaluated using the color difference value ΔE as an index. The color difference value ΔE was measured using a spectroscopic color difference meter (SZ- # 90, manufactured by Nippon Denshoku Industries Co., Ltd.). The smaller the value, the better the weather resistance.

Example 1 10 kg of ε-caprolactam, swellable synthetic fluoromica (ME-10)
0) 0.4 kg, water 1 kg and 4-amino-2,2,6,6-tetramethylpiperidine 0.028 kg (per mol of ε-caprolactam)
This corresponds to 2.0 mmol. ) Was placed in a reaction vessel having a content of 30 liters, and the pressure was increased to 15 kg / cm ² with stirring. And while gradually releasing the water vapor, the pressure is 15 kg / cm ² ,
After polymerization at a temperature of 260 ° C. for 2 hours, the pressure was released to normal pressure over 1 hour. Thereafter, the mixture was allowed to stand at 260 ° C. for 2 hours under normal pressure, then discharged in a strand form, cooled, solidified, and cut to obtain pellets of the polyamide resin composition. Next, the pellets were scoured with hot water at 95 ° C. for 8 hours, and this operation was repeated twice, followed by vacuum drying to obtain dried pellets of the polyamide resin composition.
Next, the dried pellets are injected into an injection molding machine (TOSHIBA, IS80G
Injection molding was performed with a cylinder temperature of 260 ° C, a mold temperature of 70 ° C, an injection time of 12 seconds, and a cooling time of 12 seconds.
Various test pieces of mm were prepared.

Example 2 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, 0.0176 kg of 4-butylamino-2,2,6,6-tetramethylpiperidine (ε-caprolactam 1 0.94 per mole
Millimoles. ) Was carried out in the same manner as in Example 1 except for using), and scouring, drying, and injection molding were performed to obtain dried pellets and test pieces of the polyamide resin composition.

Example 3 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, 0.038 kg of 2,2,6,6-tetramethylpiperidone (ε
It corresponds to 2.8 mmol per mol of caprolactam. ) Was carried out in the same manner as in Example 1 except for using), and scouring, drying, and injection molding were performed to obtain dried pellets and test pieces of the polyamide resin composition.

Example 4 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexa A polyamide resin composition was obtained by performing polymerization, scouring, drying and injection molding in the same manner as in Example 1 except that 0.0176 kg of methylenediamine (equivalent to 0.51 mmol per mol of ε-caprolactam) was used. Of dried pellets and test pieces were obtained.

Example 5 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, 0.039 kg of isonicotinic acid (equivalent to 3.6 mmol per mol of ε-caprolactam) was used. Except for the above, polymerization was performed in the same manner as in Example 1, and scouring, drying, and injection molding were performed to obtain dried pellets and test pieces of the polyamide resin composition.

Example 6 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, 0.054 kg of dinicotinic acid (ε-caprolactam 1
This corresponds to 3.6 mmol per mol. ) Was carried out in the same manner as in Example 1 except for using), and scouring, drying, and injection molding were performed to obtain dried pellets and test pieces of the polyamide resin composition. Various physical property tests were performed using pellets and test pieces of the polyamide resin composition obtained in Examples 1 to 6. Table 1 shows the obtained results.

[0055]

[Table 1]

Example 7 The raw materials were charged as follows: 10 kg of ε-caprolactam, 1.0 kg of swellable synthetic fluoromica (ME-100), 1 kg of water, and N, N'-bis (2,2,6,
6-tetramethyl-4-piperidyl) hexamethylenediamine
Except that 0.0176 kg (equivalent to 0.51 mmol per mol of ε-caprolactam) was used, polymerization was carried out in the same manner as in Example 1, and scouring, drying and injection molding were performed to dry the polyamide resin composition. Pellets and test pieces were obtained.

Example 8 Polymerization was carried out in the same manner as in Example 1 except that the amount of the swellable synthetic fluoromica (ME-100) was changed to 0.1 kg, and scouring, drying,
Dry pellets and test pieces of the polyamide resin composition were obtained by injection molding.

Example 9 The raw materials were charged as follows: 10 kg of ε-caprolactam, 1.0 kg of swellable synthetic fluoromica (ME-100), 1 kg of water and N, N'-bis (2,2,6,
6-tetramethyl-4-piperidyl) hexamethylenediamine
Except that the amount was 0.349 kg (equivalent to 10.0 mmol per mol of ε-caprolactam), polymerization was carried out in the same manner as in Example 1, followed by refining, drying and injection molding to obtain dried pellets of the polyamide resin composition. And a test piece were obtained. Various physical property tests were performed using pellets and test pieces of the polyamide resin compositions obtained in Examples 7 to 9. Table 2 shows the obtained results.

[0059]

[Table 2]

Example 10 10 kg of ε-caprolactam, 0.4 kg of montmorillonite (Kunipia F), 1 kg of water and 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine (2.0 mmol per mol of ε-caprolactam) Was placed in a reaction vessel having a content of 30 liters, and the pressure was increased to 15 kg / cm ² with stirring. And while gradually releasing the water vapor, the pressure is 15 kg / cm ² ,
After polymerization at a temperature of 260 ° C. for 2 hours, the pressure was released to normal pressure over 1 hour. Thereafter, the mixture was allowed to stand at 260 ° C. for 2 hours under normal pressure, then discharged in a strand form, cooled, solidified, and cut to obtain pellets of the polyamide resin composition. Next, the pellets were scoured with hot water at 95 ° C. for 8 hours, and this operation was repeated twice, followed by vacuum drying to obtain dried pellets of the polyamide resin composition.
Next, the dried pellets are injected into an injection molding machine (TOSHIBA, IS80G
Injection molding was performed with a cylinder temperature of 260 ° C, a mold temperature of 70 ° C, an injection time of 12 seconds, and a cooling time of 12 seconds.
Various test pieces of mm were prepared.

Example 11 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, 0.0176 kg of 4-butylamino-2,2,6,6-tetramethylpiperidine (ε-caprolactam 1 0.94 per mole
Millimoles. ) Was carried out in the same manner as in Example 10 except for using), and scouring, drying, and injection molding were performed to obtain dried pellets and test pieces of the polyamide resin composition.

Example 12 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, 0.038 kg of 2,2,6,6-tetramethylpiperidone (ε
It corresponds to 2.8 mmol per mol of caprolactam. ), Except that polymerization was carried out in the same manner as in Example 10.
By performing scouring, drying and injection molding, a dried pellet and a test piece of the polyamide resin composition were obtained.

Example 13 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexa Polymerization was carried out in the same manner as in Example 10 except that 0.0176 kg of methylenediamine (equivalent to 0.51 mmol per 1 mol of ε-caprolactam) was used.
Dry pellets and test pieces of the polyamide resin composition were obtained by injection molding.

Example 14 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, 0.039 kg of isonicotinic acid (equivalent to 3.6 mmol per mol of ε-caprolactam) was used. Except for the above, polymerization was performed in the same manner as in Example 10, and scouring, drying, and injection molding were performed to obtain dried pellets and test pieces of the polyamide resin composition.

Example 15 Instead of 0.028 kg of 4-amino-2,2,6,6-tetramethylpiperidine, 0.054 kg of dinicotinic acid (ε-caprolactam 1
This corresponds to 3.6 mmol per mol. ) Was carried out in the same manner as in Example 10 except for using), and scouring, drying, and injection molding were performed to obtain dried pellets and test pieces of the polyamide resin composition. Various physical property tests were performed using pellets and test pieces of the polyamide resin compositions obtained in Examples 10 to 15. Table 3 shows the obtained results.

[0066]

[Table 3]

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1, except that the raw materials were changed to 10 kg of ε-caprolactam, 0.4 kg of swellable synthetic fluoromica (ME-100) and 1 kg of water. Dry pellets and test pieces of the polyamide resin composition were obtained by injection molding.

Comparative Example 2 Polymerization was carried out in the same manner as in Comparative Example 1 except that 0.4 kg of swellable synthetic fluoromica (ME-100) was changed to 0.4 kg of montmorillonite (Kunipia F), and scouring, drying and injection molding were carried out. Thus, a dried pellet and a test piece of the polyamide resin composition were obtained.

Comparative Example 3 Polymerization was carried out in the same manner as in Comparative Example 1, except that the amount of the swellable synthetic fluoromica (ME-100) was changed to 1.0 kg.
Dry pellets and test pieces of the polyamide resin composition were obtained by injection molding.

Comparative Example 4 A swellable synthetic fluoromica (ME-100) was not charged.
Polymerization was performed in the same manner as in Comparative Example 1, and scouring, drying, and injection molding were performed to obtain dried pellets and test pieces of the polyamide resin composition. Various physical property tests were performed using pellets and test pieces of the polyamide resin compositions obtained in Comparative Examples 1 to 4. Table 4 shows the obtained results.

[0071]

[Table 4]

Comparative Example 5 Polymerization was carried out in the same manner as in Example 1 except that the amount of the swellable synthetic fluoromica (ME-100) was changed to 6.0 kg, but the viscosity was too high in the reaction vessel. , It was impossible to dispense from the reactor.

From the results in Tables 1 to 3, the following is clear. Each of the polyamide resin compositions obtained in Examples 1 to 14 is excellent in heat resistance, strength and rigidity, has high melt stability, and has no uneven dyeing. The polyamide resin composition obtained in Example 15 had excellent heat resistance, strength, and rigidity, high melt stability, and no uneven dyeing, but increased in viscosity as compared with Examples 1 to 14. It was difficult.
In addition, it was found that the polyamide resins obtained in Examples 1 to 4 and 10 to 13 were also excellent in weather resistance.

On the other hand, the polyamide resin compositions obtained in Comparative Examples 1 to 3 are inferior in melt stability and dyeability because they do not contain any of the compounds represented by Formulas 1 to 5. . The polyamide composition obtained in Comparative Example 4 is inferior in melt stability, heat resistance, strength, and rigidity because it does not contain any of the layered silicate and the compounds represented by Formulas 1 to 5. In Comparative Example 5, since the amount of the layered silicate was excessive, there was a problem that the production became difficult.

[0075]

According to the present invention, there is provided a polyamide resin composition which is excellent in heat resistance, strength and rigidity, has good operation stability, and hardly causes color unevenness during dyeing, and a process for producing the same.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuyuki Wakamura 31-3 Uji Hinojiri, Uji-shi, Kyoto Unitika Inside the Uji Plastics Factory F-term (reference) 4J001 DA01 DB01 DB02 DC12 DC13 DC14 DC24 DD20 EA06 EB08 EB09 EB25 EB36 EB37 EC07 EC08 EC09 EC16 EC27 EC29 EC47 EE18E EE65A EE65C FA03 FB03 FC03 FD01 HA01 HA02 HA04 JA01 JB02 4J002 CL011 CL031 CL051 DJ006 FA016 FD016

Claims (2)

[Claims] 1. A polyamide resin having 100 parts by mass and a layered silicate dispersed in the polyamide resin at a molecular level of 0.5 to 5 parts by mass.
A polyamide resin composition characterized in that at least one of the compounds represented by the following formulas (1) to (5) is present in a chemically bonded state in a resin composition comprising 0 parts by mass. Embedded image Embedded image Embedded image Embedded image Embedded image 2. A monomer in a state where 0.5 to 50 parts by mass of a layered silicate and at least one of the compounds represented by the above formulas 1 to 5 are present based on the amount of the monomer forming 100 parts by mass of the polyamide resin. 2. The method for producing the polyamide resin composition according to claim 1, which is polymerized.