JPH10237298A - Chip comprising polyamide resin composition and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain chips which comprise a resin composition wherein a polyamide resin and a laminar silicate are uniformly dispersed in a molecular level and which will not rise to the surface of hot water when scoured by hot water, by using a resin composition consisting of a polyamide resin and a laminar silicate and having a specified bulk specific gravity. SOLUTION: This resin composition consists of 100 pts.wt. polyamide resin and 2-50 pts.wt. laminar silicate and has a bulk specific gravity of 0.6 to 1.5 when formed into a cylinder with a diameter of 2mm and a length of 2mm. In this composition, the laminar silicate is dispersed in the polyamide resin matrix in a state wherein the laminate are kept at an interlaminar distance of at least 20Åon average from one another, separate laminate of the silicate or multi-layered materials each comprising at most 5 laminate on average are present together in parallel or at random, and at least 50% of the silicate is dispersed without forming a mass. The polyamide resin is formed from a monomer such as an aminocarboxylic acid. The laminar silicate comprises a swelling fluoromica mineral.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip made of a resin composition in which a polyamide resin and a layered silicate are uniformly dispersed at a molecular level. TECHNICAL FIELD The present invention relates to a chip made of a polyamide resin composition which does not float on a chip and a method for producing the chip.

[0002]

2. Description of the Related Art Hitherto, 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 have been 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, and the resin composition reinforced with fibrous material causes warpage of the molded product. There was a problem of becoming larger. In addition, the resin composition reinforced with the above-mentioned inorganic filler has a problem that the mechanical strength and heat resistance are not improved unless a large amount of the filler is blended.

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 (JP-A-62-74957, JP-A-63-95757). No. 230766,
JP-A-2-102261, JP-A-3-7729).

The above resin composition attempts to form a composite in which the clay mineral is uniformly dispersed at the molecular level by infiltrating a polyamide chain between layers of the clay mineral. For such a purpose, montmorillonite is used. When using montmorillonite as described in each of the above publications, before mixing montmorillonite with a polyamide or a monomer forming a polyamide, the montmorillonite is brought into contact with a swelling agent such as an aminocarboxylic acid to thereby form an interlayer distance of montmorillonite. The treatment for expanding was indispensable. Accordingly, there is a strong need in the art for an inorganic filler that does not require such treatment and can eliminate the disadvantages of conventional reinforced polyamides.

[0005] As an attempt to solve such a problem,
The present inventors have proposed that a polyamide composite having excellent mechanical strength and heat resistance can be obtained by adding a specific swellable fluoromica-based mineral to a monomer that forms a polyamide and polymerizing the same. (JP-A-6-248176).
However, when a chip made of this composite is produced on an industrial scale, a considerable amount of bubbles generated during polymerization are caught in the chip, so that when scouring with hot water, the chip becomes hot water. There was a problem of rising.

Accordingly, the present inventors have determined that a specific amount of a layered silicate, based on the amount of a monomer forming a polyamide resin,
A method for producing a reinforced polyamide with less air bubble entrapment in a chip by polymerizing a monomer in the presence of water and a molecular weight regulator capable of reacting with a carboxyl group or an amino group was previously proposed (Japanese Patent Application No. Hei 10-284,197). 7-266732
issue). However, in this method, the relative viscosity of the resin composition is
If it exceeds 2.5, there is a problem that bubbles generated during the polymerization are not sufficiently removed, and a part of the chips floats in hot water when scouring with hot water.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a chip comprising a resin composition in which a polyamide resin and a layered silicate are uniformly dispersed at a molecular level. An object of the present invention is to provide a chip made of a polyamide resin composition that does not float on hot water and a method for producing the same.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have reached the present invention.

That is, the gist of the present invention is as follows. (1) Layered silicate 2 to 100 parts by weight of polyamide resin
A chip made of a resin composition containing 50 parts by weight, and having a bulk specific gravity of 2 mm in diameter and 2 mm in length when formed into a cylindrical shape.
A chip made of a polyamide resin composition having a ratio of 0.6 to 1.5. (2) A state in which 2 to 50 parts by weight of a layered silicate and 0.001 to 10 parts by weight of a molecular weight regulator capable of reacting with a carboxyl group or an amino group are present based on the amount of a monomer forming 100 parts by weight of a polyamide resin. After polymerizing the monomer under pressure in the above, once returned to normal pressure, deaerated with nitrogen pressure of ² to 30 kg / cm2, then dispensed into strands, cooled, solidified, polyamide, characterized by cutting A method for producing a chip comprising a resin composition.

[0010]

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

The chip of the present invention is made of a resin composition in which 2 to 50 parts by weight of a layered silicate is blended with 100 parts by weight of a polyamide resin, and has a cylindrical shape having a diameter of 2 mm and a length of 2 mm. The bulk specific gravity at that time needs to be 0.6 to 1.5. When the bulk specific gravity is less than 0.6, the chips float on hot water when scouring with hot water is performed. On the other hand, if the bulk specific gravity exceeds 1.5, it is theoretically difficult to produce.

In the above polyamide resin composition, the layered silicate is uniformly dispersed at the molecular level in the polyamide resin. Here, “dispersing uniformly at the molecular level” means that when the layered silicate is dispersed in the polyamide resin matrix, each layer is maintained at an average interlayer distance of 20 ° or more. Furthermore, the interlayer distance refers to the distance between the centers of gravity of the phyllosilicate slabs, and the "uniformly dispersed" means that the phyllosilicates are layered in parallel with each other or with an average overlap of 5 layers or less. Alternatively, it refers to a state in which 50% or more, preferably 70% or more, of them are dispersed without forming a lump in a state where both random and parallel and random are mixed. Specifically, wide-angle X-ray diffraction measurement is performed on the chip of the polyamide resin composition, which can be confirmed by the disappearance of the peak due to the thickness direction of the layered silicate.

The polyamide resin in the present invention means a polymer having an amide bond formed from a monomer such as aminocarboxylic acid, lactam, or diamine and dicarboxylic acid (including salts thereof).

Examples of the above monomers include aminocarboxylic acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid, and lactams such as ε-caprolactam and ω -Laurolactam and the like.

As the diamine, tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4- / 2,4,4-
Trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 2,4-dimethyloctamethylenediamine, metaxylylenediamine, paraxylylenediamine, 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 ,
There are 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine, and the like. Examples of dicarboxylic acids are adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, terephthalic acid, Examples include isophthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, and diglycolic acid. Further, these diamines and dicarboxylic acids can be used as salts.

Preferred examples of the polyamide resin 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), polyundecamide (nylon 1
1), polydodecamide (nylon 12), polytrimethylhexamethylene terephthalamide (nylon TMHT), polyhexamethylene isophthalamide (nylon 6I), polyhexamethylene terephthal / isophthalamide (nylon 6T / 6I), polybis (1-aminocyclohexyl) )
Methanododecamide (nylon PACM12), polybis (3-
Methyl-4-aminocyclohexyl) methanetocamit (nylon dimethyl PACM12),
Polymethaxylylene adipamide (nylon MXD6), polyundecamethylene terephthalamide (nylon 11T),
Polyundecamethylene hexahydroterephthalamide (nylon 11T (H)) and their copolymerized polyamides, mixed polyamides and the like. Among them, particularly preferred are nylon 6, nylon 46, nylon 66, nylon 11, nylon 12, copolymerized polyamides thereof, and mixed polyamides.

The relative viscosity of the above polyamide resin is preferably in the range of 2.5 to 5.0 as determined by using 96% concentrated sulfuric acid as a solvent at a temperature of 25 ° C. and a concentration of 1 g / dl.

Further, it is preferable that the terminal group of the polyamide resin is blocked with a molecular weight regulator capable of reacting with a carboxyl group or an amino group.

Specific examples of the molecular weight regulator include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, pivalic acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid and myristic acid. , Palmitic acid, stearic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, benzoic acid, methylbenzoic acid, butylbenzoic acid, diethylamine, propylamine, butylamine, hexylamine, diisopropylamine, ethylenediamine, hexamethylenediamine, aniline , Methylaniline, butylaniline and the like, but aniline, benzoic acid, adipic acid, acetic acid, hexylamine,
Hexamethylenediamine is preferred, and aniline, benzoic acid, adipic acid, and hexylamine are particularly preferred. These molecular weight regulators can be used alone or in combination of two or more.

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:
Smectite group (for example, montmorillonite, beidellite, saponite, hectorite, sauconite), vermiculite group (for example, vermiculite), mica group (for example, fluoromica, muscovite, paragonite phlogopite, biotite, lepidolite), brittle mica ( For example, there are margarite, clintite, anandite), chlorite (for example, dombasite, sudoite, coucheite, clinochlore, chamosite, nimmite) and the like.

These layered silicates may be naturally occurring, artificially synthesized or modified, or treated with an organic substance such as an onium salt. Is also good.

Among the above-mentioned layered silicates, swellable fluoromica-based minerals are most preferred in terms of whiteness, which 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. )

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

There is also a method in which talc is used as a starting material, and alkali metal ions are intercalated into the starting material to obtain a swellable fluoromica-based mineral (Japanese Patent Laid-Open No. 2-1494).
No. 15). In this method, talc is mixed with an alkali silicate or an alkali fluoride, and is mixed in a magnetic crucible for about 7 minutes.
By performing a short heat treatment at 00 to 1200 ° C., a swellable fluoromica-based mineral can be obtained.

At this time, the amount of the alkali silicate or the alkali fluoride mixed with the talc is 10 to 35% of the whole mixture.
It is preferable to be within the range of weight%, and if it is out of this range, the production yield of the swellable fluoromica-based mineral is undesirably reduced.

In order to obtain the swellable fluoromica-based mineral, it is necessary that the alkali metal of the alkali silicate or the alkali fluoride is sodium or lithium. These alkali metals may be used alone or in combination. In addition, in the case of potassium among alkali metals, a swellable fluoromica-based mineral cannot be obtained, but it can be used in combination with sodium or lithium, and in a limited amount, for the purpose of adjusting the swellability. It is.

Further, in the step of producing the swellable fluoromica-based mineral, it is also possible to adjust the swellability of the resulting swellable fluoromica-based mineral by adding a small amount of alumina.

The amount of the layered silicate in the polyamide resin composition is required to be 2 to 50 parts by weight based on the amount of the monomer forming 100 parts by weight of the polyamide resin.
More preferably, it is 2 to 10 parts by weight. When the compounding amount is less than 2 parts by weight, even without using a molecular weight regulator, a chip made of a polyamide resin composition that does not float in hot water when scouring with hot water can be obtained. However, the effect of improving mechanical strength and heat resistance is small.
On the other hand, if the amount is more than 50 parts by weight, the toughness of a molded article is greatly reduced, which is not preferable.

Next, a method for producing a chip comprising the polyamide resin composition of the present invention will be described.

That is, in the method of the present invention, first, 2 to 50 parts by weight of a layered silicate and a molecular weight controlling agent capable of reacting with a carboxyl group or an amino group with respect to the monomer amount forming 100 parts by weight of the polyamide resin. Agent 0.001-10
The monomer is polymerized under pressure in the presence of parts by weight. At this time, the polymerization is conducted at a temperature of 240 to 300 ° C and a pressure of 2 to 30 kg / c
It is preferable to perform the treatment appropriately in the range of m ² for 1 to 5 hours.

Next, while maintaining the above temperature, the pressure is once returned to normal pressure, and then deaeration is performed at a nitrogen pressure of ² to 30 kg / cm ² . At this time, the time required for degassing is preferably in the range of 5 minutes to 3 hours.

Then, the resin composition obtained through the above-mentioned polymerization and degassing steps is discharged into a strand, cooled, solidified, and cut into chips. Particularly, in the case of a chip made of a nylon 6 resin composition, 90 to 1
It is practically necessary to perform scouring in hot water at 00 ° C. for 5 to 10 hours.

The chip thus obtained is usually
2-5 mm in diameter and 2-6 mm in length,
Bulk specific gravity of 0.6mm when formed into a cylinder 2mm in diameter and 2mm in length
It is in the range of ~ 1.5. The relative viscosity was determined by using 96% concentrated sulfuric acid as a solvent at a temperature of 25 ° C. and a concentration of 1 g / g.
The value obtained under the condition of dl is in the range of 2.5 to 5.0.

In the polyamide resin composition of the present invention, pigments, heat stabilizers,
Antioxidants, weathering agents, flame retardants, plasticizers, release agents, reinforcing agents, and the like may be added.

As the heat stabilizer and the antioxidant, for example, hindered phenols, phosphides, hindered amines, sulfur compounds, copper compounds, alkali metal halides, and mixtures thereof can be used.

Examples of the reinforcing agent include clay, talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, sodium aluminosilicate, and the like.
Magnesium silicate, glass balloon, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate whisker, boron nitride, graphite, glass fiber, carbon fiber, etc. .

These additives are added at the time of polymerization or at the time of melt-kneading or melt-molding the obtained resin composition.

Further, the polyamide resin composition of the present invention may be used as a mixture with another polymer. Examples of such a polymer include elastomers such as polybutadiene, butadiene / styrene copolymer, acrylic rubber, ethylene / propylene copolymer, ethylene / propylene / diene copolymer, natural rubber, chlorinated butyl rubber, and chlorinated polyethylene. And an acid-modified product thereof such as maleic anhydride, a styrene / maleic anhydride copolymer, a styrene / phenylmaleimide copolymer, polyethylene, polypropylene, butadiene / acrylonitrile copolymer,
Polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyvinylidene fluoride, polysulfone, polyphenylene sulfide, polyether sulfone, phenoxy resin, polyphenylene ether, polymethyl methacrylate, polyether ketone, polycarbonate, polytetrafluoroethylene, polyarylate, etc. There is.

The chip of the present invention can be formed into a target molded product by a usual molding method. For example, a method of forming a thin film by a hot melt molding method such as injection molding, extrusion molding, blow molding, or sintering or a casting method from an organic solvent solution can be adopted.

The molded article obtained by using the chip made of the polyamide resin composition of the present invention has remarkably improved mechanical strength, heat resistance and dimensional stability as compared with the case of using the polyamide resin alone, Little change in physical properties and dimensions. Due to their excellent performance, these molded products are mechanical parts and housings such as switches and connectors in the field of electric and electronic equipment, underbonnet parts and exterior parts in the automotive field, optical parts such as outer panel parts and reflectors, etc. Alternatively, it is used as a gear or a bearing retainer in the mechanical field.

[0042]

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 materials (1) Swellable fluoromica mineral Mineral talc ground by a ball mill to have an average particle diameter of 4 μm was mixed with sodium silicate having the same average particle diameter of 4 μm so that the total amount would be 15% by weight. This was put in a magnetic crucible and reacted in an electric furnace at 850 ° C. for 1 hour to synthesize. The powder was subjected to wide-angle X-ray diffraction measurement. As a result, the thickness of the raw material talc in the c-axis direction was 9.2.
The peak corresponding to Å disappeared, and a peak corresponding to 12 to 16 示 す indicating the formation of a swellable fluoromica-based mineral was observed.

2. Measurement method (a) Tensile strength, tensile elastic modulus and elongation at break were measured based on ASTM D-638. (b) Flexural strength and flexural modulus Measured based on ASTM D-790. (c) Izod impact strength A 3.2 mm thick test piece was measured with a notch of a predetermined depth based on ASTM D-256. (d) Heat deformation temperature Measured under a load of 18.6 kg / cm ² based on ASTM D-648. (e) Bulk specific gravity A cylindrical chip with a diameter of 2 mm and a length of 2 mm is manufactured and JIS K
Measured based on -6722.

Example 1 10 kg of ε-caprolactam, swellable fluoromica mineral 500
g, 25 g of benzoic acid as a molecular weight regulator and 1 kg of water were placed in a reaction vessel having a content of 30 liters, heated to 260 ° C. while stirring, and the pressure was increased to 15 kg / cm ² . Then, while gradually releasing the water vapor, keep the pressure at 15 kg / cm ² and the temperature at 260 ° C.
After polymerization for 1 hour, the pressure was released to normal pressure over 1 hour,
Degassing was performed at a temperature of 0 ° C. under a nitrogen pressure of 7 kg / cm ² for 1 hour. When the polymerization and degassing were completed, the above reaction product was discharged in a strand, cooled, solidified, and cut to obtain a chip made of a nylon 6 resin composition. Next, this chip was scoured with hot water at 95 ° C. for 8 hours. As a result, nothing was found in the hot water, and the chip was dried under vacuum to obtain a chip for molding. Next, using a twin-screw extruder (PCM-45 type, manufactured by Ikegai Tekko Co., Ltd.), the chip was injection-molded at a cylinder temperature of 260 ° C., a mold temperature of 70 ° C., an injection time of 6 seconds, and a cooling time of 6 seconds. A test piece having a thickness of 3.2 mm was prepared and subjected to a physical property test.

Examples 2 to 4 Nylon 6 resin composition chips were obtained in the same manner as in Example 1 except that the molecular weight regulator shown in Table 1 was used instead of benzoic acid. Using these chips, test pieces having a thickness of 3.2 mm were prepared in the same manner as in Example 1 and subjected to physical property tests.

The results in Examples 1 to 4 are summarized in Table 1. In Table 1, when chips were scoured with hot water at 95 ° C. for 8 hours, chips that did not float on the hot water and settled completely were represented by ○.

[0047]

[Table 1]

Example 5 10 kg of nylon 66 salt and 3 kg of water were placed in a 30 liter reactor and heated to 280 ° C. while stirring, and the pressure was increased to 18 kg / cm ² . And while gradually releasing the water vapor, the pressure
Polymerization was carried out for 2 hours while keeping the temperature at 18 kg / cm ² and the temperature at 280 ° C., and the pressure was released to normal pressure over 1 hour. Immediately after the pressure became normal, 500 g of a swellable fluoromica-based mineral and 25 g of benzoic acid were added. The relative viscosity of the polyamide resin composition discharged immediately after the pressure reached normal pressure was 1.6. Thereafter, polymerization was further carried out for 2 hours at a normal pressure and a temperature of 280 ° C., followed by degassing for 1 hour at a temperature of 260 ° C. under a nitrogen pressure of 7 kg / cm ² . When the polymerization and degassing were completed, the above reaction product was discharged in a strand, cooled, solidified, and cut to obtain a chip made of a nylon 66 resin composition. Next, the chip is heated to 95 ° C.
After scouring with hot water for 8 hours, nothing floating in the hot water was recognized, and the chips were dried under vacuum to form chips.
Next, this chip was inserted into a twin-screw extruder (PCM-45, manufactured by Ikegai Iron Works).
Injection molding was performed using a mold at a cylinder temperature of 290 ° C, a mold temperature of 70 ° C, an injection time of 6 seconds, and a cooling time of 6 seconds.
mm test pieces were prepared and subjected to physical property tests.

Example 6 ω-laurolactam 10 kg, swellable fluoromica mineral 500
g, 25 g of benzoic acid and 1 kg of water were placed in a 30 liter reactor, heated to 240 ° C. while stirring, and the pressure was increased to 20 kg / cm ² . Then, while gradually releasing the water vapor, polymerization was carried out for 2 hours while maintaining the pressure at 20 kg / cm ² and the temperature at 240 ° C.
After releasing the pressure to normal pressure over a period of time, the mixture was degassed for 1 hour under a nitrogen pressure of 7 kg / cm ² while maintaining the temperature at 240 ° C. When the polymerization and degassing were completed, the above reaction product was discharged into a strand, cooled, solidified, and cut to obtain a chip made of a nylon 12 resin composition. Next, this chip was scoured with hot water at 95 ° C. for 8 hours. As a result, nothing was found in the hot water, and the chip was dried under vacuum to obtain a chip for molding. Next, this chip was inserted into a twin-screw extruder (PCM-45, manufactured by Ikegai Iron Works).
Injection molding was performed using a mold at a cylinder temperature of 250 ° C, a mold temperature of 50 ° C, an injection time of 6 seconds, and a cooling time of 6 seconds.
mm test pieces were prepared and subjected to physical property tests.

Comparative Example 1 Nylon 6 was prepared in the same manner as in Example 1 except that benzoic acid was not added.
A chip made of the resin composition was obtained. This chip was scoured with hot water at 95 ° C. for 8 hours. As a result, although some of the chips floated in the hot water, they were vacuum-dried to obtain chips for molding. Next, using this chip, a test piece having a thickness of 3.2 mm was prepared in the same manner as in Example 1 and subjected to a physical property test.

Comparative Example 2 A nylon 6 resin composition was prepared in the same manner as in Example 1 except that 100 g of a swellable fluoromica-based mineral was used and degassing was not performed for 1 hour under a nitrogen pressure of 7 kg / cm ^2. A chip consisting of a product was obtained. When this chip was scoured with hot water at 95 ° C. for 8 hours, nothing was found in the hot water, and it was vacuum-dried to obtain a chip for molding. Next, using this chip,
A test piece having a thickness of 3.2 mm was prepared in the same manner as in Example 1, and subjected to a physical property test. As a result, improvement in mechanical strength and heat resistance was not sufficient.

Table 2 summarizes the results of Examples 5 to 6 and Comparative Examples 1 and 2. In Table 2, 95 ° C
When the chips were scoured with hot water for 8 hours, the chips that did not float in the hot water and settled completely were represented by ○, and the chips that partially floated in the hot water were represented by ×.

[0053]

[Table 2]

The results of wide-angle X-ray diffraction measurement of the chips in Examples 1 to 6 and Comparative Examples 1 and 2 were as follows.
In each case, the peak (12 to 16 mm) in the thickness direction of the swellable fluoromica-based mineral completely disappeared, and nylon 6
It was found that the swellable fluoromica-based mineral was uniformly dispersed at the molecular level in the resin, nylon 66 resin and nylon 12 resin matrices.

[0055]

According to the present invention, a polyamide resin composition in which a polyamide resin and a layered silicate are uniformly dispersed at a molecular level and a chip does not float in hot water when scouring with hot water is performed. Can be obtained.

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

Claims (5)

[Claims] 1. A chip made of a resin composition in which 2 to 50 parts by weight of a layered silicate is blended with respect to 100 parts by weight of a polyamide resin, and has a bulk specific gravity in the form of a cylinder having a diameter of 2 mm and a length of 2 mm. Which is 0.6 to 1.5. 2. A chip comprising the polyamide resin composition according to claim 1, wherein the layered silicate is a swellable fluoromica-based mineral. 3. A chip comprising the polyamide resin composition according to claim 1, wherein the relative viscosity of the resin composition is 2.5 to 5.0. 4. A chip comprising the polyamide resin composition according to claim 1, wherein the polyamide resin is end-blocked with a molecular weight regulator capable of reacting with a carboxyl group or an amino group. 5. A molecular weight regulator capable of reacting 2 to 50 parts by weight of a layered silicate with a carboxyl group or an amino group based on the amount of a monomer forming 100 parts by weight of a polyamide resin.
After polymerizing the monomer under pressure in the presence of 0.001 to 10 parts by weight, once returning to normal pressure, degassing is performed under nitrogen pressure of ² to 30 kg / cm2, then discharged in a strand form, cooled, A method for producing a chip comprising a polyamide resin composition, comprising cutting after solidification.