JPH0224357A - Fiber-reinforced polymer composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in chemical resistance, impact resistance, antifreeze resistance and moldability and improved in, especially, heat resistance and creep resistance by mixing a specified polyamide resin and a polyolefin as the principal components with a glass fiber. CONSTITUTION:30-90wt.%, based on the resin component, at most 85 pts.wt., per 100 pts.wt. total polyamide resin, polyamide resin which is nylon 66 and, optionally, nylon 66 and nylon 6 is mixed with 10-70wt.% total of a polyolefin (e.g., PP) and an unsaturated carboxylic acid (e.g., maleic anhydride) or, desirably, a modified polyolefin (e.g., modified PP) which can give a molar ratio of the terminal amine of the polyamide resin to the carboxyl groups of 10-1000. 100 pts.wt. resulting mixture is mixed with 5-50 pts.wt. glass fiber.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fiber-reinforced polymer composition containing polyamide resin and polyolefin as main components, and in particular has excellent chemical resistance, impact resistance, antifreeze resistance, moldability, etc. The present invention relates to a fiber-reinforced polymer composition mainly composed of a polyamide resin and a polyolefin, which has excellent heat resistance and significantly improved creep resistance.

[Conventional technology]

Polyamide resin is lightweight, impact resistant, heat resistant,
It has excellent chemical resistance, making it suitable for various containers.

On the other hand, containers such as automobile radiator tanks have come to be made of plastic to reduce weight. Nylon 6 and nylon 6 have particularly excellent strength and heat resistance.
6 with glass fiber added is often used.

However, although polyamide resin reinforced with glass fiber or the like has excellent heat resistance, mechanical strength, and long-term durability, it has problems in that it is inferior in water resistance, moldability, chemical resistance, and antifreeze resistance.

Therefore, various compositions based on polyamide resin, polyolefin, and glass fiber have been proposed.

Japanese Patent Publication No. 61-26939 discloses a modified polymer obtained by graft copolymerizing polyamide resin (a) and polypropylene resin with ethylenically unsaturated carboxylic acid or its anhydride
b) and a fibrous reinforcing agent (c), containing component (a) and (
The weight ratio of the components b) is (a): (b) ~70:
30-95: 5, and component (c) is component (a) and (
Discloses a radiator tank characterized in that it is formed from a composition containing component b) in a proportion of 40 to 200 parts by weight based on a total of 100 parts by weight.

In addition, JP-A No. 62-241940 discloses that [^] Olefin polymer: 30 to 95% by weight, [B] Polyamide = 5 to 95% by weight.
For forming an automobile radiator tank, characterized by comprising: 5 to 200 parts by weight of glass fiber in which an acrylic resin is used as a sizing agent to 70% by weight, [[ ] [8 + CB] = 100 parts by weight A plastic composition is disclosed.

[Problem that the invention seeks to solve]

However, although conventional compositions have improved the compatibility between polyamide resin and polyolefin, the adhesion between glass fibers and matrix resin, etc., they do not necessarily meet the strict conditions required for radiator tanks, etc. It wasn't.

It is therefore an object of the present invention to provide fiber-reinforced polymer compositions with significantly improved heat resistance and creep resistance.

[Means for solving problems]

In view of the above problems, as a result of intensive research, the present inventors added a predetermined amount of unsaturated carboxylic acid-modified polyolefin to a composition consisting of polyamide resin, polyolefin, and glass fiber, and by using nylon 46 as the polyamide resin. discovered that the heat resistance, mechanical properties, and creep resistance of the composition were significantly improved, and came up with the present invention.

That is, the fiber-reinforced polymer composition of the present invention contains (a) 30 to 90% by weight of a polyamide resin, and (b) a total of 10 to 70% by weight of a polyolefin and an unsaturated carboxylic acid-modified polyolefin, based on the resin component, Furthermore, it contains 5 to 50 parts by weight of (c) glass fiber, with the total amount being 100 parts by weight, and is characterized in that the polyamide resin is nylon 46.

Furthermore, 85 parts by weight or less of the nylon 46 may be replaced with nylon 66 and/or nylon 6.

The present invention will be explained in detail below.

The polyamide resin used in the present invention is nylon 46
It is. Nylon 46 is a polyamide commonly obtained from diaminobutane and adipic acid.

It has a repeating unit in which (cH2)4 is bonded via an amide bond. In the present invention, only nylon 46 can be used as the polyamide resin, but if necessary, a part of it may be replaced with nylon 66, nylon 6, or both. When containing nylon 66 and/or nylon 6, the proportion is 100% of the entire polyamide resin.
The proportion is 85 parts by weight or less. When the proportion of the nylon 66 and/or nylon 6 exceeds 85 parts by weight, heat resistance, mechanical properties, and creep resistance deteriorate.

The preferred proportion of nylon 66 and/or nylon 60 is 50 parts by weight or less.

Note that the ratio of the nylon 66 and nylon 6 can be freely selected.

In addition, the polyolefin used in the present invention includes homopolymers of α-olefins such as ethylene, propylene, butene-L-pentene-1, hexene-1,4-methylpentene-1, ethylene and propylene, or other α-olefins. - copolymers with olefins, copolymers of two or more of these α-olefins, and the like. Among these, polyethylene and polypropylene such as low density polyethylene, linear low density polyethylene, medium density polyethylene, and high density polyethylene are preferred. Polypropylene is not limited to a homopolymer, and random or block copolymers with other α-olefins containing a propylene component of 50 mol% or more, preferably 80 mol% or more can also be used. Comonomers copolymerized with propylene include ethylene and other α-olefins, with ethylene being particularly preferred. Therefore, the term "polypropylene" used herein is not limited to homopolymers of propylene, but should be understood to include copolymers as well.

The modified polyolefin used in the present invention is a polyolefin modified with an unsaturated carboxylic acid or its anhydride. Examples of unsaturated carboxylic acids or their anhydrides include monocarboxylic acids such as acrylic acid and methacrylic acid, dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, and dicarboxylic acid anhydrides such as maleic anhydride and itaconic anhydride. dicarboxylic acids and their anhydrides are particularly preferred.

In addition, as polyolefins modified with unsaturated carboxylic acids or their anhydrides, α
-It includes not only homopolymers of olefins but also copolymers with other α-olefins.

The content of unsaturated carboxylic acid or its anhydride in the modified polyolefin is such that the molar ratio of amine/carboxylic acid is 10 to 10.
The content is preferably within the range of 0.00, specifically preferably 0.01 to 15% by weight. If the amount of modification is less than 0.01% by weight, the addition of the modified polyolefin will not have a sufficient effect on improving the compatibility between the polyamide resin and the polyolefin, and if it exceeds 15% by weight, the compatibility with the polyolefin will decrease.

The modified polyolefin can be produced by either a solution method or a melt-kneading method. In the case of the melt-kneading method, the polyolefin, unsaturated carboxylic acid for modification (or acid anhydride), and catalyst are charged into an extruder or twin-screw kneader, and the
The mixture is heated to a temperature of 0° C. and kneaded while melting. In the case of a solution method, the starting material is dissolved in an organic solvent such as xylene, and the solution is stirred at a temperature of 80 to 140°C. In either case, ordinary radical polymerization catalysts can be used as catalysts, such as benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide, Peroxides such as peroxybenzoic acid, peroxyacetic acid, and tert-butyl peroxypivalate, and diazo compounds such as azobisisobutyronitrile are preferred. The amount of catalyst added is approximately 1 to 100 parts by weight per 100 parts by weight of the unsaturated carboxylic acid or anhydride thereof for modification.

In the fiber reinforced polymer composition of the present invention, the content of polyamide resin is 30 to 90% by weight based on the resin component.
So, the content of polyolefin + modified polyolefin is 1
It is 0 to 70% by weight. If the polyamide resin content is less than 30% by weight, the heat resistance and mechanical strength will be insufficient;
If it exceeds % by weight, moldability and antifreeze resistance will be insufficient and the cost will be high. The preferred range is 50 to 70% by weight of polyamide resin and 30 to 50% by weight of polyolefin+modified polyolefin.

Preferably, the amount of modified polyolefin and its amount of carboxylic acid groups is correlated to the amount of terminal amine in the polyamide resin. This is because the modified polyolefin-polyamide graft copolymer produced by reacting the carboxylic acid in the modified polyolefin with the terminal amine of the polyamide during melt blending is thought to act as a compatibilizer between the polyolefin and polyamide. This is because it is presumed that the amount of copolymer produced is related to the molar ratio of carboxylic acid group/polyamide terminal amine. Therefore, it is preferable to adjust the content of the modified polyolefin so that the ratio of the number of moles of the terminal amine to the number of moles of the carboxylic acid group in the modified polyolefin is 10 to 1000. If the amine/carboxylic acid molar ratio is less than 10, compatibilization will proceed too much, and the properties of the polyamide resin and polyolefin will average out, resulting in a decrease in heat resistance. Also, the molar ratio of amine/carboxylic acid is 1
If it exceeds 000, the compatibilizing effect of the modified polyolefin will be insufficient, and the resulting composition will have low mechanical strength. A more preferred molar ratio is 20-200.

The content of glass fiber is 5 to 50 parts by weight based on 100 parts by weight of the entire composition. If the amount of glass fiber is less than 5 parts by weight, the heat resistance and mechanical strength of the composition will be insufficient, and if it exceeds 50 parts by weight, the moldability will decrease, making it difficult to manufacture molded products, and the mechanical strength will decrease. On the contrary, it decreases. The preferred glass fiber content is 15 to 40 parts by weight.

Note that the glass fibers are chopped strands, rovings, etc., and preferably have a fiber diameter of 5 to 15 μm.

In the fiber-reinforced polymer composition of the present invention, it is preferable that the polyamide resin forms a continuous matrix phase and the polyolefin has a morphology that forms a domain phase with an average diameter of 0.5 to 5 μm. By having such a morphology, the mechanical properties of the composition such as tensile strength, flexural modulus, and impact strength are significantly improved.

The fiber-reinforced polymer composition of the present invention may also contain other additives for the purpose of modification, such as inorganic fillers, heat stabilizers, antioxidants, light stabilizers, flame retardants, plasticizers, and antistatic agents. , a mold release agent, a foaming agent, a nucleating agent, etc. can be added.

The composition of the present invention can be obtained by kneading in a heated molten state using an extruder such as a single-screw extruder or a twin-screw extruder, but it is preferably produced using a twin-screw extruder having the following structure. .

As schematically shown in FIG. 1, the twin screw extruder for producing the fiber reinforced polymer composition of the present invention is (a)
The length/diameter (L/D) ratio is 25 or more, and (b) (i) a first hopper 1 for charging the resin component, and (ii) a first hopper 1 for extruding the obtained fiber-reinforced polymer composition. a die 2; (iii) a second hopper 3 provided downstream from the first hopper 1 at a position of L/D 15 to 20 into which glass fibers are input; and (iv) the second hopper. (V) at least two sets of first kneading zones provided between the first hopper 1 and the second hopper 3; 5.5'... and (vi) at least one set of second kneading zones 6 provided between the second hopper 3 and the vacuum vent section 4, (c) A temperature of L/D 3.5 to 7.5 is set at 320°C on the upstream side from the second hopper 3.
~340 ℃, (6) other parts 300 ~
(e) The temperature of the resin at the exit of the die is set to 300-320°C.

If the L/D ratio of the twin-screw extruder is less than 25, sufficient kneading cannot be achieved. A preferred L/D ratio is 25-35.

The first hopper (main hopper) 1, the second hopper 3, the vacuum vent section 4, and the die 2 may each have a known structure.

The distance between second hopper 3 and die 2 is L/D5~20
However, if L/D is less than 5, kneading of the resin component and glass fibers will be insufficient, and if L/D exceeds 20, there is a greater possibility that the resin component will deteriorate.

The distance between the second hopper 3 and the vacuum vent part 4 is L/D
It is preferable to set it to 3-10. If the distance L/D between the two is less than 3, the binding agent for the glass fibers will not be melted and the venting effect will be small, and if it exceeds 10, venting will tend to occur.

At least one set of first kneading zones 5,5'... and second kneading zones 6 are provided. Each kneading zone is preferably a combination of four or more kneading disks (L/D 1 to 4) having L/D of about 1/4 to 1/8. If the kneading zone 5,5'... is absent or does not have a sufficient length, the kneading of the resin component will be insufficient and the plasticization will not be sufficient.

Kneading zone 6 due to insufficient kneading disks
If the length of the resin is shorter than L/DI, the cooling of the resin due to the addition of glass fibers will proceed, which will hinder the mixing of glass fibers and cause surging (pulsating flow), which will hinder production.

Generally, the tip of the first kneading zone 5.5' is located downstream of the first hopper 1 at L/D5-20, and the total length is about L/D2-8. Further, the tip of the second kneading zone 6 is located at L/D 2 to 6 on the downstream side of the second hopper 3, and the total length is L/D.
It is about 1 to 4.

Also, L/D 3.5 to 7.
If the temperature at the part 5 is not 320 to 340°C, there is a possibility that mixing of glass fibers may be similarly inhibited or surging may occur. However, if the temperature is too high, the resin will deteriorate, making it impossible to obtain the desired performance.

For other parts, the temperature is 300 to 320°C. Further, the resin temperature at the exit of the die is preferably 300 to 320°C.

The first hopper (main hopper) of the above twin screw extruder
1 and the second hopper 3.
100 to 300
The resin component and glass fibers are kneaded while rotating the two screws at a speed of rpm. The composition obtained by kneading can be easily pelletized by known methods.

The glass fiber-reinforced polymer composition of the present invention produced using the above twin-screw extruder can be molded into a desired shape by a normal injection molding method.

[For production]

Although the compatibility between polyamide resin and polyolefin is poor,
By interposing the unsaturated carboxylic acid-modified polyolefin, the two are made compatible. The reason for this is thought to be that the terminal amine of the polyamide resin reacts with the carboxylic acid group in the modified polyolefin to produce a polyamide-modified polyolefin copolymer.

Furthermore, it is made of nylon 46, and if necessary, nylon 6
By using a polyamide resin containing nylon 6 and/or nylon 6, heat resistance, mechanical properties and creep resistance are significantly improved. This is thought to be due to the addition of nylon 46, which has high crystallinity, high heat distortion temperature, and excellent creep resistance, to the components of the polymer composition.

〔Example〕

The present invention will be explained in further detail by the following examples.

Examples 1 to 5, Comparative Examples 1 to 3 Nylon 46, nylon 66,
Nylon 6, polypropylene, and modified polypropylene were tri-blended using a high-speed mixer, and the 45φ shown in Figure 1 was prepared.
It was charged from the main hopper of a twin screw extruder for carp. In addition, chopped strands of 11 glass fibers (average diameter: 13 μm, average length: 3 mm) were introduced into the twin-screw extruder at the mixing ratio shown in Table 1 and kneaded at 300° C. to obtain composition pellets.

After drying the obtained composition pellets in a drying oven, test pieces were prepared by injection molding, and the following tests were conducted.

(1) Heat deformation temperature = When the temperature is raised at a constant rate (2°C/min), a test piece (simple burr) of 110 s
! ) JIS K? Measured by 207.

(2) Tensile strength: Measured according to JIS K7113 at 23°C and 140°C.

(3) Flexural modulus = Measured according to JIS K7203 at 23°C and 140°C.

(4) Izot impact strength: Measured according to JIS K7110 at 23°C and -40°C.

(5) Antifreeze resistance = After immersing in a 50% aqueous solution of commercially available long-life automotive coolant at 140°C for 200 hours, the tensile strength in the water-absorbed state was measured, and the tensile strength retention rate when the original tensile strength was set as 100 ( %).

Note that in (2) to (4), measurements were performed under dry conditions and water absorption conditions, respectively. The drying condition means that the product immediately after injection molding is placed in a desiccator and kept at 23° C. for 75 hours, and the water absorption condition means that the injection molded product is immersed in water at 100° C. for 24 hours.

The results are shown in Table 1.

Note): (1) Nylon 46, nylon 66, nylon 6
The content of polypropylene and modified polypropylene is weight % based on the resin content, and the content of glass fiber is weight % based on the entire composition.

(2) Made by Unitika ■ Unitika Nylon 46Korsh
ak-Zamyat 1ona's method (Do-Ren-tyoho) (c
hem, Abs, 40.4665. '46. Same as above 42.6152. The terminal amine group measured in '48) was 0.026 m equivalent, 7 g.

(3) Orsha to Amiran CM3001N manufactured by Toshi ■
k-Zamyationa method (same method as (2))
The terminal amine 7 group measured in 1 was 0.034 m equivalent and 7 g.

(4) Unitika tJ@! ! A1030BRT or
The terminal amino group measured by the method of Shak-Zamyat 1ona (same method as (2)) is 0.042 equivalent/
It was g.

(5) J-215 manufactured by Toshin Petrochemical ■ (6) Maleic anhydride (7) M^03FT-2 manufactured by Asahi Fiberglass ■ Examples 6-7 In Examples 1-2, high-density polyethylene was used instead of polypropylene. A fiber-reinforced polymer composition was produced in the same manner except that the above-mentioned polyethylene was modified with the carboxylic acid shown in Table 2 as the modified polyethylene. This was subjected to the same tests as in Examples 1 and 2. The results are shown in Table 2.

Note): (1), (2), (3), (4), (6), (7
) Same as Table 1 (5) J-6311 High-density polyethylene manufactured by Toshin Petrochemical ■ As is clear from the above, the fiber-reinforced polymer composition of the present invention contains unsaturated carboxylic acid that helps make the polyamide resin and polyolefin compatible. In addition to containing modified polyolefin, by using nylon 46 and, if necessary, nylon 66 and/or nylon 6 as the polyamide resin, it has excellent mechanical strength, molded bottom, antifreeze resistance, etc., and heat resistance. Its properties and creep resistance have been significantly improved.

〔Effect of the invention〕

As detailed above, the fiber-reinforced polymer composition of the present invention not only has excellent mechanical strength such as tensile strength and impact resistance, but also has excellent heat resistance, moldability, antifreeze resistance, and creep resistance. It's also excellent. Furthermore, since the water absorption rate is reduced, there is little deterioration in the properties under water absorption conditions. Furthermore, it has the advantage of reduced costs due to the relatively large amount of polyolefin it contains.

Such a composition of the present invention is particularly suitable for use in engine peripheral parts such as automobile radiator tanks, electrical equipment parts such as bobbins, and the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating an example of equipment that can be used to produce the fiber-reinforced polymer composition of the present invention. 1... ・... ・First hopper 2...
・・・ ・・・・・・ ・・・Dice 3・・・・・・・・・
...Second hopper 4...
...Bent 5.5' ...First kneading zone 6... -Second kneading zone exit
Applicant Tonen Petrochemical Co., Ltd. Nippondenso Co., Ltd.

Claims (2)

[Claims] (1) Based on resin components (a) Polyamide resin 30
90% by weight, (b) polyolefin and unsaturated carboxylic acid-modified polyolefin 10 to 70% by weight, and (c) glass fiber 5
50 parts by weight of a fiber-reinforced polymer composition, wherein the polyamide resin is nylon 46. (2) The fiber reinforced polymer composition according to claim 1, wherein the polyamide resin further contains nylon 66 and/or nylon 6 in a proportion of 85 parts by weight or less based on 100 parts by weight of the polyamide resin. A fiber-reinforced polymer composition.