JPH03167257A - Production of highly heat-resistant, glass fiber-reinforced polyamide composition - Google Patents

Abstract

PURPOSE:To achieve the optimization of product properties by mixing a glass fiber into a mixture comprising a polyamide resin and an ABS resin and molding the resulting mixture on a screw-type injection molding machine equipped with a mixing and dispersing mechanism. CONSTITUTION:100 pts.wt. mixture comprising 30-70 pts.wt. polyamide resin and 70-30 pts.wt. rubber-reinforced styrenic graft copolymer (e.g. ABS resin) is mixed with 20-100 pts.wt. glass fiber. The resulting mixture is molded on a screw-type injection molding machine equipped with a mixing and dispersing mechanism (in accordance with Japanese Patent Publication No.56(1981)-47847) to give a glass fiber-reinforced polyamide-ABS alloy with a high heat distortion temp.

Description

[Detailed description of the invention] <<a>>. FIELD OF INDUSTRIAL APPLICATION This invention relates to improved glass fiber reinforced polyamide compositions. aFL< presents a method for improving the physical properties of glass fiber relaxed polyamide. Mountain". BACKGROUND OF THE INVENTION Polyamide resins have excellent properties such as mechanical strength, rigidity, and chemical resistance, so they are used as engineering plastics in various mechanical parts. However, the disadvantages of polyamide resins include high impact resistance, especially notch sensitivity, and high water absorption, which not only degrades the dimensional stability of shaped products, but also significantly reduces mechanical properties, especially flexural modulus, when water is absorbed. This can be mentioned. As a means to improve this drawback, a so-called polymer alloy method in which 11 types of polymer materials are blended has been proposed. Among these, an alloy of boria ξ-d and acrylonitrile-styrene-butadiene copolymer resin (hereinafter referred to as ABS) is known. However, since polyamide and ABS generally have poor compatibility, they have the disadvantage that when molded products are made, mechanical properties may not be as expected or the layer peeling phenomenon may occur. Therefore, conventional technological improvements have focused on improving the compatibility of both resins and improving mechanical strength, especially impact resistance. for example,
In JP-A No. 58-93745, A of a general ternary combination (acrylonitrile, styrene, butadiene) is used for polyamide.
The expected impact resistance was improved by blending BS with modified ABS, which was copolymerized by adding 0.5 to 15% of unsaturated carbonamide, and melt-kneading it using a twin-screw extruder. No. 777,211, in order to improve the impact strength of a combination of polyamide resin and ABS, an ethylene-alkyl acrylate rubber containing an acid such as maleic anhydride is used as a third component, and anhydrous It is an essential condition that a styrene copolymer containing an acid such as maleic acid, such as a styrene-methyl methacrylate-maleic anhydride terpolymer, be blended as the fourth component. Moreover, in JP-A-64-66255, polyamide and AB
In order to improve the compatibility of S, we created a four-component system of ABS and As (styrene-acrylonitrile copolymer), which have functional groups derived from carboxylic acid, and a maleated ethylene propylene copolymer, and used this as a biaxial It presents a method for making an aggressive composition by melt-mixing using an extruder.

In addition, in JP-A-1-156355, Polya main do 20-8
100 parts by weight of a mixture of 0 parts by weight and 20 to 80 parts by weight of ABS, etc.
In a composition containing 5 to 100 parts by weight of an inorganic filler per part by weight, the presence of an N-substituted maleimide styrene copolymer and AS or MS (styrene-methyl methacrylate copolymer) is an essential condition, We propose melt-mixing this using a single-screw extruder, twin-screw extruder, Banbury mixer, etc. In this way, in the prior art, boria mite' and ABS
Emphasis is placed on improving the dispersion state of ABS and the adhesion between the substrate and the dispersed phase, and for this purpose, methods include copolymerizing other components into the ABS component, or blending third and fourth polymer components. I rely on it. Each of these is claimed to have an effect, and the overall effect of improving impact resistance is emphasized, but on the other hand, the third and fourth precepts of adding them are due to the price of raw materials and small-scale production. It is inevitable that costs will rise.
Furthermore, as for the performance sacrificed due to this combination, since conventional technology uses acid modification or amide modification of ABS, it is clear that Ild wettability is inevitably lower than that of original ABS, and polyamide alloy The problem is that the physical properties of polyamide, which is one of the major purposes for making it, do not improve as much as expected when it absorbs water. Furthermore, as for compounding conditions, a general-purpose single-screw extruder, a twin-screw extruder, etc. are only suggested, and no special effects of compounding conditions are mentioned. Furthermore, in the prior art, optimization of physical properties for reinforcing material formulation has not been considered. In other words, most conventional techniques only state that glass fibers, inorganic fillers, etc. can be added to the composition, but do not mention the benefits and disadvantages of the proposed combination when such reinforcing materials and inorganic fillers are added. It has not been done. In other words, the conventional polyamide-ABS alloy technology, especially when viewed as a glass fiber reinforced material, does not provide optimal performance, and there is also the problem of increased costs, so improvements in these areas are strongly desired. It was rare.

{C}. Problems to be Solved by the Invention The inventors of the present invention have identified the problems that the invention seeks to solve in the prior art. As a result of intensive study on optimization through the formulation, formulation technology, and formulation process of the glass-grade fiber formulation of polyamide/ABS alloy, we have determined the optimum physical properties of the product as detailed below. They found a means to not only achieve this, but also prevent an increase in material costs, and have completed the present invention.

1d). Means to solve problems The present invention will be explained in detail below.

In conventional technology, polyamide and ABS have poor compatibility;
It was a general knowledge that strength, appearance, etc. would not be satisfied unless some kind of chemical modification was performed. As a result of intensive research into this problem, the inventors of the present invention discovered that general polyamide and ABS can be sufficiently mixed and dispersed under specific melt-mixing conditions detailed below. Glass fiber reinforced polyamide-A that could not be achieved
Succeeded in demonstrating the physical characteristics of BS alloy,
I completely abandoned this invention. The polyamide referred to in this list is a polymer with an amide bond in the main chain, and is a linear polymer obtained by polycondensation of diamine and dibasic acid, ring-opening polymerization of lactam, polycondensation of aminocarboxylic acid, etc. It is. Examples of polyamides include polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 610), polycaprolactam (nylon 6), polyundecanoamide (nylon 11), polylauryllactam (nylon 12) etc. The formulations of the invention include copolymers such as nylon 6.
-66, and also mixtures of polyamides, such as mixtures of nylon 66 and nylon 6. The polyamide of the present invention is
Preferred is polycabrolactam (nylon 6). ABS referred to here is a material made by graft polymerizing styrene and acrylonitrile monomers to a rubber-based polymer, and the rubber-based polymer is mainly polyptadiene.
Styrene-butadiene rubber is also used. Generally, the rubber component in the melon mixture is 10~40 parts by weight, and the styrene is 50~40 parts by weight.
80 parts by weight, and 20 to 50 parts by weight of acrylic nitrile. Emulsion polymerization is the most commonly used method for producing ABS, and it is produced by adding both styrene and acrylonitrile monomers to polybutadiene latex and polymerizing them. Therefore, ungrafted styrene-acrylonitrile copolymer naturally coexists in the product. However, the method for producing ABS is not limited to this, and may also be produced by bulk polymerization, suspended 7Q polymerization, etc. The ABS used in the present invention does not contain a quaternary component in an amount that substantially alters its chemical, mechanical, or thermal properties. The present invention uses 30 to 70 parts by weight of Boreami ■H fat, AB34
M fat 30~? (Achieved by mixing 20 to 100 parts by weight of glass fiber with 100 parts by weight of a mixture of resin pellets or powder consisting of 1 part and molding the mixture using an injection molding machine equipped with the following mixing mechanism. The structure of the screw-type injection machine equipped with a mixing mechanism used here is as follows.In other words, the screw has a plasticizing/kneading section that is formed in multiple flights following the feed section. There is a gap between the cough cylinder and the inner wall of the cylinder that is large enough to create shear, and the cough cylinder has a plurality of four parts that are continuous in the axial direction. This mechanism is disclosed in Japanese Patent Publication No. 56-47847.This mechanism also functions to disperse and mix chopped glass fiber strands in a molten resin.

The reason why this mechanism is particularly effective for mixing the alloys is not clear, but it is presumed as follows. In other words, the action of a screw used in a general extruder or injection machine mainly applies pressure to the resin and causes it to flow spirally within the flight, thereby plasticizing and mixing it. The mechanism used in the present invention plasticizes and mixes and disperses different components by applying shearing force to the resin at the top of the flight and the inner wall of the cylinder, and the resulting molten resin mass is transferred between the screw and the recess on the inner surface of the cylinder. By repeatedly switching back and forth between the two, the distribution state is made uniform. This action causes the ABS melt to be torn apart and dispersed into fine particles in the polyamide matrix. Therefore, unlike the conventional technology, AB
S is well dispersed in the polyamide matrix.

The present invention presents a method to enable glass fiber reinforced boria-based ABS alloys to exhibit the best physical properties. The present inventors discovered that the glass woven fiber-reinforced polyamide ABS alloy produced using unmodified ABS as described above is similar to that of acid-modified ABS.
This invention has been perfected by discovering that it not only has superior mechanical performance, but also provides superior performance, especially at heat distortion temperatures, compared to conventional technology using The reason for this is not clear, but it is presumed as follows. That is, the polyamide resin has good adhesion to the glass fiber, and the surface of the glass fiber is completely covered with the polyamide resin.

In alloys containing unmodified ABS, the ABS is finely dispersed in the polyamide matrix, and it is thought that the polyamide contacts the glass fibers preferentially. In this state of polyamide-ABS alloy, ABS, which has weaker adhesion to glass fibers than polyamide, does not inhibit the adhesion of polyamide to glass fibers, and the heat distortion temperature is lower than when polyamide alone is reinforced. It's small. On the other hand, if acid-modified ABS is used, the adhesion of ABS to glass fibers improves, which inhibits the adhesion of polyamide to glass fibers. When ABS is in close contact with glass fibers, the heat distortion temperature of the assembly is affected by ABS, and it can be estimated that it is significantly lower than that of a reinforced product made of polyamide alone. This fact can be clearly explained by the example below. The glass fiber-reinforced polyamide alloy of the present invention is prepared using inorganic fillers such as mica, talc, calcium carbonate, wollastonite, silica, glass beads, ceramic beads, gold fi powder, etc., carbon fiber, and aluminum alloy according to known techniques. Reinforcing materials such as fibers, coloring agents, etc. may be added. The glass fiber reinforced boria textured alloy according to the present invention can be clearly understood from the following examples.

《e》. Function The present invention is achieved by injection molding a mixture of polyamide, ABS, and chopped strand glass plow fibers using an injection molding machine equipped with a kneading mechanism described in Japanese Patent Publication No. 56-47847, which could not be achieved with the prior art. This made it possible to produce a glass fiber reinforced polyamide ABS alloy with physical properties, particularly high heat distortion temperatures, that were previously unavailable. (O. Example (1) Reference example! (Production of modified ABS) AB S 4
A {fat (Daicel Chemical Industries f1!!! Sepian V300
Powder) 1500g, maleic anhydride (Mitsubishi Kasei Kyu) 15g, 2000rrJ! Mix in a Spartanori User (manufactured by Fuji Powder), add 6 g of Rifutinol Peroxide (manufactured by Nippon Oil & Fats Corporation) in a dither,
Add a solution diluted with 15 g of toluene, and boil for 500 r.
/m for 3 minutes.

This mixture was mixed using a 35 mmφ continuous M kneading extruder manufactured by KCK at a cylinder temperature of 250°C and a screw rotation speed of 6.
Or/m, extrusion rate 10kg/hrs, strands were cooled with water, pelletized, maleic anhydride modified ABS
(hereinafter referred to as M-ABS) was created. (2) Reference example 2 (manufacture of polyamide/ABS polymer alloy) Polyamide (nylon 6 10l IFB manufactured by Ube Industries)
, ABS (above), and M-ABS were blended in predetermined amounts as shown in Table 1, and a 35-shaft Φ continuous M kneading extruder made by nKCK was used at a cylinder temperature of 250°C, a screw speed of 6 Or/m, and an extrusion amount. The strands were extruded at 10kg/hr, cooled with water, and then pelletized to produce a polyamide/ABS alloy. The produced polycarbonate/ABS alloy was manufactured using an NS75 injection molding machine made by Niigata Tekko 91, and was manufactured using ASTMD.
638 and D750 test pieces were prepared. The results of measuring the physical properties of this test piece are shown in Table 1. As is clear from the results, when M-ABS was blended, the Izoft impact value was particularly improved, and the effect of the modified ABS prepared in the reference example was recognized.

(3) Manufacturing Examples 1 to 3 of glass fiber-reinforced boria pattern/ABS alloy, polyamide pellets (nylon 6 101 1FB manufactured by Ube Industries ■) with the weights listed in Table 2,
ABS (Sevian v30 made by Daicel Chemical Industries (I1J)
0 PELEFT), glass fiber (Nittobo Qli!13PE
-454) in a drum blender and
Using an injection molding machine (Sumitomo Heavy Industries nsi!!i00T) equipped with a kneading mechanism described in -47847, the mixture is fed from the supply feeder in conjunction with the rotation of the main screw, and the ASTM D63B and D7
A test piece specified in No. 50 was molded. The molding conditions were a cylinder temperature of 260°C and a screw rotation speed of 100 r/m. (The resin content and glass fibers were well dispersed in the test specimens with no damage, and no defects were observed in appearance. Comparative Examples 1 to 3,
In the same manner as Examples 1 to 3, however, maleic anhydride-modified ABS (M-ABS) prepared in the reference example was used instead of ABS.
) was used for molding. In the obtained test piece, both the resin content and the glass fiber were well dispersed, and no defects were observed in appearance. Table 2 shows the results of physical property measurements of Examples 1 to 3 and Comparative Examples 1 to 3. As a result, the examples containing unmodified ABS were superior in terms of Izont impact value and heat distortion temperature. (gl, Effects of the Invention The present invention has developed a manufacturing method for producing a glass fiber-reinforced polyamide-ABS alloy with high mechanical strength and heat distortion temperature.
This is an industrially useful invention in the sense that it eliminates the need for the use of BS or the addition of a third component, thereby contributing not only to improving physical properties but also to reducing manufacturing costs. Table 1 Table 2 (1) Table 2 (2)

Claims (2)

[Claims] (1) Mixture 10 of 30 to 70 parts by weight of polyamide resin and 30 to 70 parts by weight of rubber-reinforced styrene graft copolymer
A glass fiber-reinforced product characterized by mixing 20 to 100 parts by weight of glass fiber to 0 parts by weight and producing a molded product using a screw injection molding machine equipped with a mixing and dispersing mechanism described in Japanese Patent Publication No. 56-47847. A method for producing a polyamide composition. (2) The method for producing a glass fiber-reinforced polyamide composition according to claim (1), wherein the rubber-reinforced styrenic graft copolymer is an ABS resin.