JP2003012922A - Impact-resistant polyamide resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impact-resistant polyamide resin molding improved in weatherability. SOLUTION: There is provided a polyamide resin molding formed by molding a resin prepared by reacting an ω-lactam in the presence of an alkali catalyst, a polyfunctional polymerization co-catalyst and a polyoxyalkylenepolyamine, wherein at least one antioxidant having an amino group is further caused to present during the reaction.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyamide resin molded body. More specifically, it relates to an impact-resistant polyamide resin molded product that is improved in terms of weather resistance and releasability.

[0002]

It is known to react a lactam in the presence of a polyether having an amino group in order to improve the impact resistance of a polyamide resin. For example, Japanese Examined Japanese Patent Sho 60-43
No. 369 describes high impact polyamides obtained by polymerizing ω-lactams in the presence of alkali catalysts, polyfunctional catalysts and polyoxyalkylene amines. Further, JP-B-7-96616 describes a polyamide polyether block copolymer obtained by polymerizing a lactam in the presence of a basic catalyst, a polyisocyanate cocatalyst, and a specific amino-terminated polyether. . These polyamide resins show improved impact resistance. However, the molded product of the resin has poor releasability from the mold. Further, the molded product has poor weather resistance, and its mechanical properties are largely deteriorated due to long-term use, especially when used outdoors.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an impact resistant polyamide resin molded article having improved weather resistance. Furthermore, it is an object of the present invention to provide an impact-resistant polyamide resin molded product having improved mold release properties.

[0004]

Means for Solving the Problems As a result of various studies, the present inventors have found that the above object can be achieved by the presence of a specific antioxidant when the lactam is reacted. That is, the present invention relates to a polyamide resin molded product obtained by molding a resin prepared by reacting an ω-lactam in the presence of an alkali catalyst, a polyfunctional polymerization promoter and a polyoxyalkylene polyamine. And a polyamide resin molded body obtained by further containing at least one kind of an antioxidant having an amino group. Preferably, the antioxidant having an amino group is selected from diphenylamine derivatives, and more preferably octylated styrenated diphenylamine. The antioxidant having an amino group is ω-lactam
The amount is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight. Further, the present invention is 0.01% to 100 parts by weight of ω-lactam.
The present invention also relates to each of the above polyamide resin molded products containing 3 parts by weight of carbon black. In each of the above polyamide resin molded bodies, the ω-lactam is preferably ε-caprolactam. In addition, by the monomer casting method, ω
-It is preferable to carry out from the reaction of the lactam to the molding.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide resin of the present invention is characterized by being prepared in the presence of an antioxidant having an amino group. This improves the weather resistance of the obtained molded body. In the present invention, the weather resistance is evaluated by the retention of tensile elongation before and after UV irradiation, and the details will be described later. As the antioxidant having an amino group, known ones can be used. Examples include aromatic amines,
And its derivatives such as diphenylamine derivatives such as alkylated diphenylamine, octylated diphenylamine, octylated styrenated diphenylamine, 4,
4-bis (α, α-dimethylbenzyl) diphenylamine, p- (p-toluenesulfonylamide) diphenylamine, a reaction product of diphenylamine and 2,4,4-trimethylpentene; a phenylenediamine derivative such as N, N
-Diphenyl-p-phenylenediamine, N, N-di-2-
Naphthyl-p-phenylenediamine, N-phenyl-N-
Isopropyl-p-phenylenediamine, N-phenyl-
N- (1,3-dimethylbutyl) -p-phenylenediamine, N-phenyl-N- (3-metalloyloxy-2-hydroxypropyl) -p-phenylenediamine; and N
-Phenyl-1-naphthylamine; so-called hindered amines such as piperidine derivatives; and imidazole derivatives such as 2-mercaptobenzimidazole, 2-mercaptomethylimidazole; and mixtures thereof. Of these, diphenylamine derivatives, particularly octylated styrenated diphenylamine are preferred.

The above amino group-containing antioxidant is 0.01 to 10 parts by weight, preferably 100 parts by weight of ω-lactam.
It is used in 0.1-5 parts by weight, most preferably 0.1-3 parts by weight. If the amount is less than the lower limit, the effect of the antioxidant is not sufficient, while if the amount exceeds the upper limit, discoloration of the resin molded product over time tends to increase.

The ω-lactam used in the molded article of the present invention preferably has 4 to 12 carbon atoms, for example, γ-
Butyrolactam, ε-caprolactam, ω-enanthlactam, ω-caprylolatam, ω-laurolactam,
And mixtures thereof. Among them, ε−
Caprolactam is preferred.

As the alkali catalyst, any known material can be used. Examples include alkali metals,
For example, lithium, sodium, potassium; alkaline earth metals such as magnesium, calcium; and hydrides of these metals such as lithium hydride, sodium hydride, potassium hydride; oxides such as sodium oxide, potassium oxide; hydroxides. , For example sodium hydroxide, potassium hydroxide; carbonates, for example sodium carbonate,
Potassium carbonate; alkylated products such as methyl sodium, ethyl sodium, methyl potassium, ethyl potassium; alkoxides such as sodium methylate, sodium ethylate, potassium methylate, potassium ethylate; Grignard compounds such as methyl magnesium bromide, ethyl magnesium bromide; Reaction products with ω-lactams, such as the sodium and potassium salts of ω-lactam; and mixtures thereof. Sodium hydride is preferably used.

The amount of the alkali catalyst added is usually 0.05 to 10 mol%, more preferably 0.1 to 2 mol%, based on 100 mol% of the sum of the ω-lactam and the catalyst.

As the polyfunctional polymerization promoter, bifunctional or higher functional isocyanates, acyl lactams, carbamide lactams, isocyanurate derivatives, acid halides,
And one or more selected from urea derivatives and the like. Examples include tolylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, m-xylene diisocyanate, 4,4′-diphenylmethane diisocyanate, polyisocyanate,
For example, polymethylene polyphenylene polyisocyanate and carbodiimide-modified diisocyanate, carbamide lactam such as 1,6-hexamethylene biscarbamide caprolactam, and N, N-diphenyl-p-phenylene biscarbamide caprolactam, N-acetyl-ε-caprolactam, triallyl isocyanate. Nurate, acid chloride,
Examples include terephthaloyl chloride, adipoyl chloride and sebacoyl chloride, polyacyl lactams such as adipoyl biscaprolactam and terephthaloyl biscaprolactam, 1,3-diphenylurea, and the like, and mixtures thereof. Preferably, diisocyanates and carbamidolactams are used.

The amount of the polyfunctional cocatalyst added is 0.02 to 100% by mole of the ω-lactam and the polymerization cocatalyst.
It is 4.0 mol%, preferably 0.1 to 2.0 mol%.

In the present invention, examples of the polyoxyalkylene polyamine include polyoxyethylenediamine, polyoxypropylenediamine, polyoxytetramethylenediamine, polyoxyalkylenetriamine and mixtures thereof. Among them, polyoxyalkylene triamine is preferable, for example, Jeffamine T-5000.
(Trademark) (manufactured by Harzmann Corporation) is preferably used.

The amount of polyoxyalkyleneamine used is
It can be appropriately determined depending on the molecular weights of the amine and ω-lactam, but preferably ω-lactam 100.
1 to 50 parts by weight, more preferably 3 to 2 parts by weight
0 parts by weight. If the amount is less than the lower limit value, the impact resistance is not sufficiently improved, and if it exceeds the upper limit value, mechanical properties and the like are impaired, which is not preferable.

The polyamide resin in the present invention is obtained by reacting an ω-lactam in the presence of a polymerization catalyst, a polyfunctional co-catalyst, a polyoxyalkylene amine, and an amino group-containing antioxidant. These components may be mixed and reacted in any order. Further, prior to the reaction of the ω-lactam, the polyoxyalkylene polyamine may be reacted with a part of the polyfunctional co-catalyst to form a prepolymer.
Preferably, a part of the ω-lactam is mixed with the polyoxyalkylene polyamine and the polymerization catalyst, the remaining part of the ω-lactam is mixed with the polymerization cocatalyst and the amino group-containing antioxidant, and each is melted to form a two-part liquid. And the two liquids are mixed and reacted at the time of molding. When carbon black to be described later is mixed, carbon black is dispersed in either or both of the two liquids.

The above reaction is carried out at a temperature above the melting point of the ω-lactam and below the melting point of the polyamide produced. ω
When ε-caprolactam is used as the lactam, the reaction is preferably carried out at 100 ° C to 180 ° C. Also,
The time required for the reaction is appropriately determined depending on the monomer, the catalyst, the size and shape of the molded body, etc.
It is less than or equal to the time, preferably about 10 to 45 minutes. After the reaction, heat treatment may be performed, for example, at 190 ° C. for about 30 minutes.

The obtained polyamide resin can be molded into pellets or chips, which can be injection-molded or extrusion-molded to obtain a molded product. It is preferable to cast the two liquids into a mold and react them by the monomer casting method, because molding of the resin can be performed at once.

Carbon black is preferably added to the molded article of the present invention. Thereby, the mold releasability of the molded body is improved especially in the cast molding method. As carbon black, furnace black, thermal black,
Various materials such as acetylene black and channel black can be used, but furnace black is preferably used. The blending amount of carbon black is preferably 0.01 to 3 parts by weight, and more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the ω-lactam.

Various additives such as pigments, dyes, antibacterial agents, plasticizers, fibers and the like may be further added to the molded article of the present invention within a range not impairing the object of the present invention.

The polyamide resin molded product according to the present invention thus obtained is suitably used as a mechanical part such as a roller, an axle, a bearing, a guide or the like by utilizing its excellent impact resistance and weather resistance.

[0020]

EXAMPLES The present invention will be described below with reference to examples. Evaluation method (1) Izod impact test (with notch) A sample piece was prepared from the center of the molded body, and ASTM D-256
It was measured according to. The sample piece was subjected to an absolute dry treatment (105 ° C., vacuum state for 3 days), held in a constant temperature oven set to each temperature shown in Table 1 for 3 hours or more, and then immediately subjected to an impact test. (2) Weather resistance test A test piece for a tensile test according to ASTM D-638 was prepared from the center of the molded body. Wavelength 256 in UV irradiation box
One side of the test piece was irradiated with ultraviolet rays of nm, the test piece was inverted, and the other surface was irradiated in the same manner. After irradiation for a total of 25 days, the test piece was placed in a constant temperature and humidity room at 23 ° C. and a relative humidity of 25 ± 5% for 3 days, and then subjected to a tensile test according to ASTM D-638. (3) Releasability evaluation The reaction solution was injected into a mold (inner diameter 70 mm x height 100 mm) for 30
After the lapse of minutes, the mold was turned upside down and the time until the molded body came out of the mold due to spontaneous fall was measured. ◎: Within 1 minute ○: Within 20 minutes ×: Over 20 minutes

The antioxidants shown in Tables 1 and 2 are as follows, respectively. 1: Octylated styrenated diphenylamine (ANTAGE OD (trademark), manufactured by Kawaguchi Chemical Industry Co., Ltd.) 2: Reaction product of diphenylamine and 2,4,4-trimethylpentene (IRGANOX 5057 (trademark), Ciba Specialty Chemicals) 3: 1,3-benzenedicarboxamide-N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl (Nyrostab (trademark), manufactured by Qualiant)) 4: 3 , 9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy}
-1,1-Dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane (Adeka Stab AO80 (trademark), manufactured by Asahi Denka Co., Ltd.) 5: ethylenebis (oxyethylene) bis [3- (5
-T-butyl-4-hydroxy-m-tolyl) propionate (IRGANOX 245 (trademark), manufactured by Ciba Specialty Chemicals Co., Ltd.) 6: Pentaerythritol tetrakis [3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate] (IRGANOX 1010 (trademark), manufactured by Ciba Specialty Chemicals Co., Ltd.) 7: 2,2′-methylenebis- (6-t-butyl-4-)
Methylphenol) (SEENOX 224M (trademark), manufactured by Cypro Kasei Co., Ltd.) 8: 1,3,5-trimethyl-2,4,6-tris-
(3,5-di-t-butyl-4-hydrokcibenzyl)
-Benzene (SEENOX 326M (trademark), Cypro Kasei Co., Ltd.)
9: Tetrakis [methylene-3- (dodecylthio) propionate] methane (Adeka Stab AO412S (trademark), manufactured by Asahi Denka Kogyo Co., Ltd.)

Examples 1-5 and Comparative Examples 1-8 50 parts by weight of anhydrous ω-lactam (ε-caprolactam) was placed in a stainless steel beaker and heated to 150 ° C. Polymerization promoters (isophorone diisocyanate) in the amounts shown in Table 1 and the respective antioxidants were added thereto and stirred to form a uniform solution. On the other hand, 50 parts by weight of anhydrous ε-caprolactam was placed in another beaker made of stainless steel, and 0.17 parts by weight of sodium hydride (63% oily) as a polymerization catalyst and polyoxyalkylene polyamine (Jeffer Min T-5000) was added and heated to 150 ° C. Next, after mixing these two liquids so as to be uniform, the mixed liquid was preheated to 160 ° C. in a molding die (inner diameter 70 mm × height 200 mm)
Injected inside. The molded body was taken out 30 minutes after the injection.
Comparative Example 1 does not contain a polyoxyalkylene polyamine and an antioxidant, Comparative Example 2 does not contain an antioxidant, and Comparative Example 3 does not contain a polyoxyalkylene polyamine.
The same procedure as in Examples 1 to 5 was repeated. Table 1 shows the evaluation results of each molded product. In addition, Comparative Examples 5 to 8 could not be evaluated due to poor molding.

[0023]

[Table 1]

Comparative Examples 1 to 8 all lack the requirements of the present invention. Comparative Example 1 lacks polyoxyalkylamine, and therefore has a significantly low Izod impact strength. Comparative Example 2 lacking an antioxidant having an amino group has low retention of both tensile strength and elongation, and Comparative Examples 3 and 4 have significantly low retention of tensile elongation.

Examples 6 to 9 and Comparative Example 9 Carbon black (Ketjen Black EC, manufactured by Lion Corporation) in the amounts shown in Table 2 was added to a mixed solution of anhydrous ε-caprolactam and Jeffamine T-5000. The same procedure as in Example 1 was repeated except that the above was dispersed. here,
In all examples, 0.5 parts by weight of ANTAGE OD was used as the amino group-containing antioxidant. Table 2 shows the evaluation results of each molded product. Comparative Example 9 could not be evaluated due to poor molding.

[0026]

[Table 2]

As can be seen by comparing Comparative Example 1 and Comparative Example 2, if polyoxyalkylene amine is present during the reaction of ω-lactam, the releasability is lowered. However, by incorporating carbon black according to the present invention, releasability is remarkably improved (Examples 6 to 9).

[0028]

The polyamide resin molded product of the present invention exhibits excellent weather resistance. Further, by incorporating carbon black, the releasability is improved.

Continued front page    F-term (reference) 4F071 AA54 AB03 AC11 AC12 AC13                       AE05 AF23 AF53 AF57 AH17                       BA02 BB01 BC07                 4J001 DA01 EA02 EA04 EA06 EA08                       EC05 EC06 EC07 EC77 EE04D                       EE35E EE43E EE44E EE57D                       EE58D EE65D EE72E EE87D                       FA03 FC03 GA12 GB02 GB11                       HA03 JA02 JB13 JB21 JB22                       JB50 JC01                 4J002 CL011 DA037 EJ016 EN016                       EN066 FD076 GM00

Claims (8)

[Claims] 1. A polyamide resin molded article obtained by molding a resin prepared by reacting an ω-lactam in the presence of an alkali catalyst, a polyfunctional polymerization co-catalyst and a polyoxyalkylene polyamine. And a polyamide resin molded body obtained by further containing at least one kind of an antioxidant having an amino group. 2. The polyamide resin molded product according to claim 1, wherein the antioxidant having an amino group is selected from diphenylamine derivatives. 3. The polyamide resin molding according to claim 2, wherein the antioxidant having an amino group is octylated styrenated diphenylamine. 4. From 0.01 to 100 parts by weight of ω-lactam.
The polyamide resin molded product according to any one of claims 1 to 3, wherein 10 parts by weight of an antioxidant having an amino group is present. 5. 0.1 to 5 relative to 100 parts by weight of ω-lactam.
The polyamide resin molded product according to claim 4, wherein an antioxidant having an amino group is present in parts by weight. 6. 0.01 to 100 parts by weight of ω-lactam
The polyamide resin molded product according to any one of claims 1 to 5, which contains 3 parts by weight of carbon black. 7. The polyamide resin molded product according to claim 1, wherein the ω-lactam is ε-caprolactam. 8. The polyamide resin molding according to claim 1, wherein the reaction is carried out by a monomer casting method.