JPH0224355A - Fiber-reinforced polymer composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excelling in heat resistance, chemical resistance, antifreeze resistance and moldability and improved in, especially, impact resistance and modulus by mixing a polyamide resin and a polyolefin as the principal components with a glass fiber and a specified nucleator. CONSTITUTION:30-90wt.%, based on the resin component, polyamide resin (e.g., nylon 66) is mixed with 10-70wt.% total of a polyolefin 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 of 10-1000. 100 pts.wt. resulting mixture is mixed with 5-50 pts.wt. glass fiber an 0.03 pts.wt. at least one nucleator selected from among a metal salt of an aromatic carboxylic acid (e.g., sodium benzoate), a metal salt of an alkyl-substituted aromatic carboxylic acid (e.g., aluminum p-tert-butylmonohydroxybenzoate), and dibenzylidenesorbitol.

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, which has particularly excellent heat resistance, chemical resistance, antifreeze resistance, moldability, etc. In particular, the present invention relates to a fiber-reinforced polymer composition mainly composed of polyamide resin and polyolefin, which has significantly improved impact resistance and elastic modulus.

[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, polyamide resin, polyolefin and glass #a
Various fiber-based compositions have been proposed.

Japanese Patent Publication No. 61-26939 contains modified polymers obtained by graft copolymerizing polyamide resin (a) and polypropylene resin with ethylenically unsaturated carboxylic acid or its anhydride) and a fibrous reinforcing agent (c), (a) Ingredients and (
c) Component weight ratio (a):ra)=70:30-95
Discloses a radiator tank characterized in that it is formed from a composition comprising: 5 and component (c) in a ratio of 40 to 200 parts by weight based on a total of 100 parts by weight of component (a) and component (A). are doing.

In addition, JP-A-62-241940 discloses [A) olefin polymer: 30 to 95% by weight, [8) polyamide: 5 to 95% by weight]
70% by weight, [C] [^) + (BE = 100 parts by weight, glass fiber in which acrylic resin is used as a sizing agent: 5 to 200 parts by weight) for forming an automobile radiator tank. 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 impact resistance and modulus.

[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 added a specific nucleating agent. The inventors discovered that a fiber-reinforced polymer composition with significantly improved impact resistance and elastic modulus can be obtained, 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 (3) a total of 10 to 70% by weight of a polyolefin and an unsaturated carboxylic acid-modified polyolefin, based on the resin component, Further, (c) 5 to 50 parts by weight of glass fibers, and (d) 0.00% of at least one nucleating agent selected from the group consisting of the following (a), (b), and (c), with the total amount being 100 parts by weight. 03 to 3 parts by weight.

(a) Metal salts of aromatic carboxylic acids, (b) Metal salts of alkyl group-substituted derivatives of aromatic carboxylic acids, (c) Dibenzylidene sorbitol.

The present invention will be explained in detail below.

The polyamide resin used in the present invention includes hexamethylene diamine, decamethylene diamine, dodecamethylene diamine, 2.2.4- or 2.4.4-)limethylhexamethylene diamine, 1.3- or 1.4-)
- aliphatic, cycloaliphatic or aromatic diamines such as bis(aminomethyl)cyclohexane, bis(p-aminocyclohexylmethane), n- or p-xylylene diamine and adipic acid, sheric acid, sebacic acid, Polyamide resin produced from aliphatic, alicyclic or aromatic dicarboxylic acids such as cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, 6-aminocaproic acid, 11
- polyamide resins made from aminocarboxylic acids such as aminoundecanoic acid, 12-aminododecanoic acid, ε
- Polyamide resins produced from lactams such as caprolactam and ω-dodecalactam, copolyamide resins consisting of these components, or mixtures of these polyamide resins. Specifically, nylon 6,
Nylon 66, Nylon 610, Nylon 91, Nylon 6/66, Nylon 66/610. Nylon 6/1
1st prize is mentioned.

Among these, nylon 6 has good rigidity and heat resistance.
and nylon 66 are preferred.

Although the molecular weight is not particularly limited, the relative viscosity η, (J
A polyamide resin having an IS (measured in 6810.98% sulfuric acid) of 1.0 or more is used, and among them, a polyamide resin of 2.0 or more is preferable because it has excellent mechanical strength.

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

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 or acid anhydride for modification) and catalyst are put into an extruder or twin-screw kneader, etc.
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, a conventional radical polymerization catalyst can be used as a catalyst, such as benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide. , peroxybenzoic acid, peroxyacetic acid, tertiary-butyl peroxypivalate, and diazo compounds such as azobisisobutyroniol (IJ). The amount of the catalyst added is about 1 to 10.0 parts by weight per 100 parts by weight of the unsaturated carboxylic acid for modification or its anhydride.

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
Weight at 0-70% 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 55 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 order to improve impact resistance and elastic modulus, the fiber-reinforced polymer composition of the present invention has at least one selected from the group consisting of (a), (b) and (c) below, based on 100 parts by weight of the entire composition. Contains 0.03 to 3 parts by weight of one nucleating agent.

(a) Metal salts of aromatic carboxylic acids, (b) Metal salts of alkyl group-substituted derivatives of aromatic carboxylic acids, (c) Dibenzylidene sorbitol.

If the content of the nucleating agent is less than 0.03 parts by weight, the above effects will be lost, and if it exceeds 3 parts by weight, no further effects will be seen and this will only lead to an increase in cost. The preferred content is 0.05 to 1 part by weight.

Specific examples of the compounds (a) and (b) above include:
Sodium benzoate, P-tert-butyl aluminum benzoate, titanium P-tert-butyl benzoate, chromium P-tert-butyl benzoate, aluminum monophenylacetate, aluminum-P-tert-butyl monohydroxybenzoic acid, etc. can be mentioned.

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. When the polyamide resin forms a continuous matrix phase, or when the average diameter of the polyolefin domains is less than 0.5 μm, the heat deformation resistance of the composition is extremely low. In other words, the polyamide resin forms a continuous matrix phase, which makes the polyamide resin the backbone of the resin, and by making the domain diameter of the polyolefin 0.5 μm or more and not making it compatibilized with the polyamide resin more than necessary, it has high heat resistance. is retained. Furthermore, if the average diameter of the polyolefin domains exceeds 5 μm, the mechanical properties of the composition such as tensile strength, flexural modulus, and impact strength will be significantly insufficient.

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)
A first hopper 1 having a length/diameter (L/D) ratio of 25 or more, and (b) (i) handling the resin component.
(ii) a die 2 for extruding the obtained fiber-reinforced polymer composition; and (iii) glass fibers provided at a position of L/D 15 to 20 toward the downstream side from the first hopper 1. (iv) a vacuum vent section 4 provided between the second hopper 3 and the die 2; (V) the first hopper 1 and the second hopper. (vi) at least two sets of first kneading zones 5.5' provided between the second hopper 3 and the vacuum vent section 4; (c) a temperature of L/D 3.5 to 7.5 on the upstream side from the second hopper 3;
0 to 320 °C, (d) other parts to 26
(e) The temperature of the resin at the exit of the die is set to 260 to 290°C.

If the L/D ratio of the twin-screw extruder is less than 25, sufficient kneading cannot be achieved.The preferred L/D ratio is 25 to 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. Distance L/D between both
If it 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, it will be easy to vent.

At least one set of the first kneading zones 5,5'...and the second kneading zones 6 are provided. Each kneading zone is preferably a combination of four or more kneading disks having L/D of about 1/4 to 1/8 (L/D 1 to 4). If the kneading zone 5,5'... is absent or does not have a sufficient length, the resin components will not be sufficiently mixed, 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/D2 to 60 positions on the downstream side of the second hopper 3, and the total length is L/D1.
It is about 4.

Also, L/D 3.5 to 7.
If the temperature at the part 5 is not 290 to 320°C, there is a possibility that the mixing of glass fibers may be similarly inhibited or surging may occur. However, if the temperature is too high, the resin will deteriorate and the desired performance will not be obtained.

For other parts, the temperature is 260 to 290°C. Further, the resin temperature at the exit of the die is preferably 260 to 290°C.

The first hopper (main hopper) of the above twin screw extruder
Input the resin component from 1, and the surface-treated glass fiber from the second hopper 3.
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, the effect of the nucleating agent greatly improves the impact resistance and elastic modulus of the composition. This is because by adding the above nucleating agent, the spherical crystals of the polyamide resin and polyolefin become finer, improving the affinity between crystal particles and between the resin component and glass fibers, and increasing the degree of crystallinity. This is thought to be due to the

〔Example〕

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

Examples 1 to 6, Comparative Examples 1 to 3 Nylon, polypropylene, modified polypropylene, and a nucleating agent were tri-blended in the blending ratios shown in Table 1 using a high-speed mixer, and the mixture was tri-blended using a 45φmm twin-screw extruder as shown in Figure 1. Injected from hopper. In addition, chopped strands of glass fiber (average diameter 13 μm 1
(average length 3 mm) was introduced from the middle of the twin-screw extruder to 28
The mixture was kneaded at 0°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) MFR=275℃ according to JIS K7210
, measured under a load of 2160 g.

(2) Heat deformation temperature = When the temperature is raised at a constant rate (2°C/min), a 110 mm x 45 x 12.7 mm test piece (simple sliver) is subjected to a constant load (18.6 kg / crl) and a predetermined amount (0 , 25 aun) was measured according to JIS K7207.

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

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

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

(d) 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 ( %).

In addition, in (3) to (5), 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.

:(1) The contents of nylon, polypropylene and modified polypropylene are weight % based on the resin content, and the contents of glass fiber and nucleating agent are weight % based on the entire composition.

(2) Amiran CM3001NKorshak manufactured by Toshi ■
-2amyat 1ona's method (do-renden method) (che
m, Abs, 40.4665. '46. Same as above 4
2.6152. The terminal amine 7 group measured in '4B) is 0
．． 034 m equivalent was 7 g.

(3) Manufactured by Toshin Petrochemical ■ J-215 (4) Maleic anhydride (5) Manufactured by Asahi Fiberglass ■ MAO3FT-2 (d
) Sodium benzoate (7) Aluminum-P-tert-butyl-monohydroxybenzoic acid (8) Dibenzylidene sorbitol, high-density polyethylene (Toshin Petrochemical J-631)
A fiber-reinforced polymer composition was produced in the same manner as above, except that 1) and the above-mentioned polyethylene modified with the carboxylic acid shown in Table 2 were used as the modified polyethylene.

This was subjected to the same tests as in Examples 1 to 3. Second result
Shown in the table.

Examples 7 to 9 In Examples 1 to 3, instead of polypropylene Note): (
1), (2), (4) to (8) Same as Table 1 (3) J-6311 manufactured by Toshin Petrochemical ■ High-density polyethylene As is clear from the above, the m-fiber reinforced polymer composition of the present invention It not only contains unsaturated carboxylic acid-modified polyolefin that helps make polyamide resin and polyolefin compatible, but also contains the nucleating agent mentioned above, which improves mechanical strength, heat resistance, moldability, antifreeze resistance, etc. In addition to being excellent, impact resistance and elastic modulus are significantly improved.

〔Effect of the invention〕

As detailed above, the fiber-reinforced polymer composition of the present invention not only has excellent chemical resistance, heat resistance, and moldability, but also has significantly improved impact resistance and elastic modulus due to the nucleating agent. ing. 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 DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating an example of equipment that can be used to produce the IIl fiber-reinforced polymer composition of the present invention. 1... ・ ・ ・ ・First hopper 2... ・
・・・・・・ ・・ ・Dice 3・・・・・・・・
...Second hopper 4...
・Vent 5.5′ ・・First kneading zone 6... Second kneading zone Applicant Tonen Petrochemical Co., Ltd. Nippondenso Co., Ltd.

Claims (1)

[Claims] (a) Polyamide resin 30 to 90 based on the resin component
and (b) a total of 10 to 70% by weight of polyolefin and unsaturated carboxylic acid-modified polyolefin, further assuming that the total is 100 parts by weight (c) glass fiber 5
~50 parts by weight, and (d) the following (a), (b) and (c)
at least one nucleating agent selected from the group consisting of 0.0
3 to 3 parts by weight. (a) Metal salts of aromatic carboxylic acids, (b) Metal salts of alkyl group-substituted derivatives of aromatic carboxylic acids, (c) Dibenzylidene sorbitol.