JPS60223822A - Production of filled polyamide - Google Patents

Abstract

PURPOSE:To disperse a filler uniformly, by adding a specified polymer to one of the following components in the production of a polyamide from a component containing an omega-lactam and an alkaline catalyst and a component containing an omega-lactam and a promotor. CONSTITUTION:A filled polyamide is produced by mixing and polymerizing (A) a component comprising an omega-lactam (e.g., epsilon-caprolactam) and an alkali catalyst (e.g., sodium methylate) with (B) a component comprising an omega-lactam and a promotor (e.g., phenyl isocyanate) and (C) a filler (e.g., glass fiber). By adding a polymer being soluble in a molten omega-lactam, having an average MW >=100,000 and selected from polyethylene oxide and polyvinylpyrrolidone to at least one of components A and B, the flotation or settlement of the filler can be prevented and a polyamide in which the filler is uniformly dispersed can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for preventing sedimentation or flotation of fillers contained in component (A) consisting of an ω-lactam and an alkali catalyst and/or component (B) consisting of an ω-lactam and a co-catalyst. is,
The present invention relates to a method for producing polyamide in which filler is uniformly dispersed.

A method of polymerizing an ω-lactam by the action of an alkaline catalyst and a cocatalyst, the so-called alkaline polymerization method, is known. The polyamide obtained by this method has high tensile strength, bending strength,
It has excellent mechanical properties such as initial elastic modulus, and is used as mechanical parts such as bearings, bushes, gears, and rolls. However, depending on the application, further improvements in rigidity, dimensional stability, heat resistance, and abrasion resistance are required. To improve these properties, fillers such as glass fiber, milled glass, glass powder, wollastonite, potassium titanate fiber, carbon fiber, calcium carbonate, molybdenum disulfide, graphite, and Teflon powder are incorporated. This is well known.

However, in the alkaline polymerization method, the specific gravity of the monomer in the molten state and the true specific gravity of the filler differ, so the filler whose true specific gravity is larger than the monomer in the molten state settles, and the filler whose true specific gravity is smaller than the monomer in the molten state floats. , it is very difficult to uniformly disperse these fillers. In addition, since molding of omega-lactam using the alkaline polymerization method is usually carried out in a mold while the mold is still, the filler in the resulting polymer floats or settles, resulting in uneven dispersion of the filler. It is known that there are problems such as

Many methods have been proposed to solve the above problems.

For example, a method is known in which the polymerization rate is extremely increased to quickly increase the viscosity of the polymerization system to prevent the filler from floating or settling. This method has the disadvantage that bubbles and cracks are likely to occur in the molded product obtained.

Another method is known in which the filler is uniformly dispersed by using a dispersant, but this method has disadvantages such as the dispersant slowing down the polymerization rate and reducing the polymerization rate and properties of the polyamide. There is.

JP-A-49-86499 describes poly-ε- in which molybdenum disulfide is uniformly dispersed by dispersing molybdenum disulfide in the presence of polyamide that is soluble in ε-caprolactam and has a thickening effect. A method for producing caprolactam is described. This method is industrially disadvantageous because it takes time to melt the polyamide into ε-caprolactam.

Japanese Patent Publication No. 52-15640 describes a method in which ε-caprolactam is polymerized in the presence of 5 to 10% by weight of ω-laurolactam, and fillers are dispersed in the polymer. In this method, when the amount of filler added increases, it becomes difficult to uniformly disperse the filler.

The present invention does not have such drawbacks, and the component (A) and the component (B
) There is provided a method for producing polyamide in which the filler is uniformly dispersed without sedimentation or floating of the filler in the polyamide.

The present invention provides a component (A) consisting of an ω-lactam and an alkali catalyst, and a component (B) consisting of an ω-lactam and a cocatalyst.
When producing polyamide by mixing component (A) with
and component (B), a polymer selected from polyethylene oxide and polyvinylpyrrolidone, which has an average molecular weight of 100,000 or more and is soluble in molten ω-lactam, is blended. This is a method for producing filler-containing polyamide.

According to the present invention, due to the thickening effect of polyethylene oxide or polyvinylpyrrolidone dissolved in component (A) and/or component (B), sedimentation or floating of the filler is prevented, and component (A) and component By mixing and polymerizing (B), a polyamide in which filled particles are uniformly dispersed can be obtained.

Specific examples of ω-lactams used in the present invention include γ
-butyrolactam, δ-halerolactam, ε-caprolactam, ω-enanthracum, ω-capryllactam, ω-undecanolactam, ω=laurolactam, C-
Alkyl-substituted -ε-caprolactam is mentioned. These ω-lactams may be used alone or in combination of two or more. Among them, ε-caprolactam, ω
-laurolactam and mixtures of ε-caprolactam and ω-laurolactam are preferred.

As the alkali catalyst, all compounds used in known alkaline polymerization methods of ω-lactams can be used. Specific examples thereof include alkali metals, alkaline earth metals, their hydrides, oxides, hydroxides, carbonates, alkoxides, Grignard reagents, and reaction products of the above metal compounds and ω-lactams, such as Examples include sodium salt, potassium salt, and bromomagnesium salt of ε-caprolactam. The amount of alkaline catalyst used is ω
- from 0.05 to 10 mol%, especially 0.2, based on the lactam
It is preferable that it is 5 mol%.

As for the co-catalyst, any known co-catalyst for alkaline polymerization can be used. Specific examples include phenyl isocyanate, cyclohexyl isocyanate, naphthyl isocyanate, toluene diisocyanate, 4.4-
Isocyanates such as diphenylmethane isocyanate-1., hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, xylylene diisocyanate, diisocyanate-1. in the carbodiimide group;
Carbamide caprolactams such as hexamethylene-1,6-piscarhamidocatellolactam, N,N-diphenyl-p-phenylenebiscarbamide lactam: acid chlorides such as benzoyl chloride, terephthaloyl chloride, sebacoyl chloride acyl lactams such as acetylcaprolactam, benzoyl biscaprolactam, adipoyl biscaprolactam, terephthaloyl biscaprolactam, and isofucloyl biscaprolactam. The promoter may be used alone or in combination of two or more. Among the co-catalysts, isocyanes-1, carbamide lactams and acyllactams are preferably used. The amount of co-catalyst used is 0.05 to 10 mol%, especially 0.2 to 5 mol% based on the ω-lactam.
Preferably it is mol%.

Specific examples of fillers used in the present invention include glass fiber, milled glass, glass powder, wollastonite,
Examples include potassium ditanate fiber, carbon fiber, calcium carbonate, molybdenum disulfide, graphite, and Teflon powder. Among these fillers, fibrous fillers, particularly milled glass having an aspect ratio of 10 to 50, are preferably used. The amount of filler used varies depending on the type, shape, etc. of the filler, but it is preferably 1 to 50% by weight, particularly 5 to 30% by weight, based on the total amount of component (A) and component (B). .

In the present invention, one of component (A) and/or component (B) is a polymer selected from polyethylene oxide and polyvinylpyrrolidone, which has an average molecular weight of 10,000 or more and is soluble in molten ω-lactam. is blended. If the average molecular weight of the polymer is smaller than the above lower limit, the thickening effect will be small and it will not be possible to obtain a polyamide in which the filler is uniformly dispersed. Among polymers, polyvinylborolidone is soluble in molten ω-lactam regardless of its average molecular weight, but polyerylene oxide has an excessively high average molecular weight (if the average molecular weight is too high, it will not dissolve in molten ω-lactam, so the average molecular weight It is necessary to use a polymer with a molecular weight of about 3 million or less.The amount of polymer used varies depending on the type of filler and the amount added, but it is 0.2 to 10% by weight based on each component containing fillers. In particular, it is preferably 0.5 to 6% by weight.If the amount of the polymer used is less than the above lower limit, the thickening effect will be small;
The filler contained in component (A) and/or component (B) tends to settle or float, making it impossible to obtain a polyamide in which the filler is uniformly dispersed. If the amount of filler used is larger than the above upper limit, the physical properties of the resulting polyamide will deteriorate. In addition, when the amount of filler used is 20% by weight or more, it is preferable to mix the filler and the polymer with both component (A) and component (B).

It is desirable that each raw material used in the present invention be sufficiently hydrophilically dried before use.

The alkaline polymerization of ω-lactam in the present invention can be carried out by mixing component (A) and component (B) according to a known method.

The polymerization temperature is higher than the melting point of the ω-lactam to be polymerized,
And the temperature is below the melting point of the polyamide to be produced. Polymerization time is usually 2 hours or less. Component <A) and component (B)
The mixing ratio by weight is 10;l to 1:lOl, especially 5
:1-1:5 is preferable.

In the present invention, additives that do not substantially inhibit the polymerization reaction, such as plasticizers, blowing agents, dyes, pigments, antioxidants, ultraviolet absorbers, mold release agents, and impact modifiers, are added in advance to the component (A).
) and/or component (B).

The present invention is useful as a method for directly producing molded products such as round rods, plates, pipes, home appliance parts, and automobile parts from ω-lactam by a casting method or a reaction injection molding method.

Next, Examples and Comparative Examples will be shown. In Examples and Comparative Examples, the sedimentation time is determined by heating component (A) or component (B) containing filler to 120°C, placing it in a test tube with a diameter of 30M to a height of 10am, and stirring thoroughly. 120℃
This is the time it takes for the top 1 m (1 m) to become transparent.The content of filler in the molded product is determined by placing the sample in a crucible and burning it, then baking it in an electric furnace to make it constant. It was measured.

Example 1 (1) Preparation of component (A) 1130 g of substantially anhydrous ε-caprolactam was placed in a flask and melted at 120°C. 47 g of dried polyvinylpyrrolidone (manufactured by Tokyo Kasei Co., Ltd., K2O, average molecular weight 360,000) was added to this flask and melted with stirring. 10.8 g of sodium methylate powder was added to this solution and the prepared methanol was removed under reduced pressure. Furthermore, as a filler, dried milled glass [manufactured by Unitika UMG Co., Ltd., short fiber B5-25T]
392 g was added and maintained at 120° C. with stirring.

(2) 1130 g of steel-made substantially anhydrous ε-caprolactam of component (B) was placed in a flask and melted at 120°C. In this flask, dried polyvinylpyrrolidone [manufactured by Tokyo Kasei Co., Ltd., K2O,
49 g of average molecular weight 360,000 was added and melted with stirring. Add hexamethylene diisocyanate 42 to this solution.
g and further dried milled glass as a filler [
Add 407 g of Short Fiber ES-25'r, manufactured by Unitika U.M. Glass Co., Ltd., and mix for 12 hours while stirring.
It was kept at 0°C.

Samples were taken from each of component (A) and component (B), and the settling time was measured. The results are shown in Table 1.

(3) Polymerization 500 g of each of the above components (A) and (B) were placed in a separable flask, stirred and mixed, and the mixture was immediately
WI & 30 C111 preheated to 0℃, width 2ctn,
The mixture was placed in a mold having a cavity 30 cm deep, and the mold was held in an oil bath at 160°C for about 15 minutes. When the content of the filler in each corner and center of the obtained molded article was measured, it was found to be 24.7 to 25.2% by weight, indicating that it was uniformly dispersed.

Table 1 18 minutes 8 18 minutes 30 seconds Comparative example 1 (1> Preparation of component (A) 1130 g of substantially anhydrous ε-caprolactam was placed in a flask and melted at 120°C. 10.8 g of sodium methylate powder was added to the flask and the prepared methanol was removed under reduced pressure.

Furthermore, as a filler, dried milled glass [manufactured by Unitika U.M. Glass Co., Ltd., short fiber B5-25] was used as a filler.
7] 378 g was added and maintained at 120° C. with stirring.

(2) Preparation of component (B) 1130 g of substantially anhydrous ε-caprolactam was placed in a flask and melted at 120°C. 42 g of hexamethylene diisocyanate was added to this flask, and dried milled glass [Unitika UEM Glass] was added as a filler.
Co., Ltd., short fiber ES 725T] 391
g was added and maintained at 120° C. with stirring.

Samples were taken from each of component (A) and component (B), and the settling time was measured. The results are shown in Table 2.

(3) Polymerization A molded article was prepared from the above components (A) and (B) in the same manner as in Example 1.

The filler content in each corner and center of the obtained molded article was 20.3 to 30.5% by weight, and the filler was non-uniformly dispersed.

Table 2 "[]--j Lamp 1 A 2 minutes 25 seconds B 2 minutes 20 seconds Example 2 (1) Preparation of component (A) In place of polyvinylpyrrolidone, dry polyethylene oxide [manufactured by Steel Chemical Co., Ltd.] , PE0-1, average molecular weight 150,000 to 400,000] Component (A) was prepared in the same manner as in Example 1 except that 47 g was used.

(2) Preparation of component (B) The procedure was the same as in Example 1, except that 49 g of dried polyethylene oxide (manufactured by Tetsutsu Kagaku Co., Ltd., PEO-1, average molecular weight 150,000 to 400,000) was used instead of polyvinylpyrrolidone. Component (B) was prepared.

Samples were taken from each of component (A) and component (B), and the settling time was measured. The results are shown in Table 3.

(3) M synthesis A molded article was prepared from the above components (A) and (B) in the same manner as in Example 1.

The filler content in each corner and center of the obtained molded article was 24.5 to 25.3% by weight, and the filler was uniformly dispersed.

Table 3 "[" 2 - Shen Feng Piegan - A 21 minutes B 21 minutes 40 seconds Patent applicant Ube Industries Co., Ltd. procedural amendment June 1982 ttLl Commissioner of the Japan Patent Office 1. Patent application for indication of the case 1982 -78388 No. 2, Name of the invention: Process for manufacturing filler-containing polyamide 3, Relationship with the person making the amendment: Patent applicant Postal code: 755 1-12-32 Nishihonmachi, Ube City, Yamaguchi Prefecture None. Spontaneous correction.

5. i' of the invention subject to amendment? Detailed Explanation 1 6. Contents of Amendment 111 On page 6, line 12, the description of ``14,4-dipheninylmethane'' is corrected to ``r4.4-Schiff, L-nylmethane.''

(2) Page 6, No. The description of r, N, N-j in line 18 is corrected to 1"N, N'-J.

(3) The description of "Scarhamidolactam" on page 6, line 19 is corrected to [Scarbamide caprolactam J].

(4) Delete the statement "1 or more" on page 8, line 6.

(5) [Create] on page 11, line 6 and page 13, line 4. The description of j is amended to "partially reside."

that's all

Claims (1)

[Claims] Component (A) consisting of an ω-lactam and an alkali catalyst;
When producing a polyamide by mixing component (B) consisting of an ω-lactam and a co-catalyst, component (A) and component (
Production of a filler-containing polyamide characterized in that at least one of B) contains a polymer selected from polyethylene oxide and polyvinylpyrrolidone having an average molecular weight of 100,000 or more and soluble in molten ω-lactam. Method.