JPH07324162A - Polyamide resin composition and molded product thereof - Google Patents

Abstract

PURPOSE:To obtain a polyamide resin composition useful in the production of a molded product having low modulus and being excellent in heat resistance, chemical resistance, moldability, mold release, etc. CONSTITUTION:This composition is one comprising a polyamide resin and a thermoplastic polyurethane resin, wherein the polyamide resin forms a continuous phase, the thermoplastic polyurethane resin forms a disperse phase, and the tensile modulus of this composition is 7000kg/cm<2>.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyamide resin composition and molded articles such as tanks and tubes molded therefrom. More specifically, it is useful for the production of molded products that have excellent gasoline resistance, oil resistance, low elastic modulus, and excellent heat resistance, chemical resistance, moldability (release properties), which are the characteristics of polyamide resins. It is a good thing, a gasoline tube,
Widely used for hoses, packing, cams, gears, etc.

[0002]

2. Description of the Related Art In recent years, research on polymer blends has progressed, and various multi-component resin compositions having high impact resistance have been developed. Generally, a polyamide resin mixed with an olefin-based polymer or a styrene-based polymer is known as high-impact nylon or low-water-absorption nylon, and examples thereof include nylon / polypropylene and nylon / AB.
S, nylon / polypropylene rubber, etc.

In order to reduce the elasticity of polyamide resin, polyamide (NT6, NT1) is used for the hard segment.
2, aromatic polyamide), polytetramethylene ether glycol (PTMG), polypropylene glycol (PPG) as a soft segment, and polyamide elastomer and polyamide urethane copolymer obtained by block copolymerizing an aliphatic polyester diol are known. It is possible to reduce the elastic modulus, but heat resistance, oil resistance and gasoline vapor resistance are not necessarily satisfactory. On the other hand, although it has been proposed to blend thermoplastic polyurethane with polyamide, it is necessary to blend a large amount of thermoplastic polyurethane for lowering the elasticity, in which case the thermoplastic polyurethane serves as a matrix, There is a problem in that the gasoline vapor resistance, oil resistance, hydrolysis resistance, moldability (mold release property), which are the drawbacks of resins, are extremely reduced.

[0004]

Therefore, the present invention has an object to disperse a large amount of thermoplastic polyurethane in a polyamide resin composition in a continuous phase which is a polyamide resin, and the polyamide resin is always continuous. When in phase, the conventional problems can be solved, and a composition having a low elastic modulus and excellent heat resistance, oil resistance, heat resistance, chemical resistance, and moldability (release property) can be obtained. Of.

[0005]

Means for Solving the Problems
To solve the problem, that is, to use a large amount of thermoplastic polyurethane
Even when blended with a Liamide resin, these polymers are
The results of diligent studies to obtain a composition that is in a dispersed phase
As a result, the present invention was finally completed. That is, the present invention
Is a polyamide resin (A) and a thermoplastic polyurethane
A composition containing a resin (B), comprising the polyamide
Resin (A) is the continuous phase, thermoplastic polyurethane resin
(B) forms a dispersed phase, and the tensile modulus of the composition is 7,
000 kg / cm ²Polya characterized in that
Mid resin composition and polyamide resin (A) and heat resistant
A composition containing a plastic polyurethane resin (B)
The polyamide resin (A) forms a continuous phase,
Polyurethane resin (B) forms a dispersed phase and has the following formula
Polyamide resin composition characterized by satisfying (1)
It is a thing.

[0006]

[Chemical 2] [Wherein MFR (A) is the MFR value of the polyamide resin (A) at the processing temperature during processing, MFR (B) is the MFR value of the thermoplastic polyurethane resin (B) at the processing temperature during processing, φ _A represents the weight% of the polyamide resin (A) with respect to the total of the polyamide resin (A) and the thermoplastic polyurethane resin (B)]

The polyamide resin which is the component (A) in the present invention includes a semi-crystalline resin and an amorphous resin, and it is possible to use what is generally called a nylon resin. The polyamide resin is produced by condensing a saturated dicarboxylic acid having 4 to 12 carbon atoms and a diamine having 4 to 14 carbon atoms in an equimolar amount, and an excess of the diamine or dicarboxylic acid is used so that the end of the polyamide is more than a carboxyl group. The amine groups may be in excess and vice versa. Specifically, polyhexamethylene adipamide (6,6 nylon), polymethaxylylene adipamide (MXD-6 nylon), polyhexamethylene aceramide (6,9 nylon) and polyhexamethylene dodecanoamide ( 6,12 nylon), a polyamide produced by ring opening of a lactam, that is, polycaprolactam (6 nylon), polylaurinlactam (12 nylon), poly-
Includes 11-amino-undecanoic acid (11 nylon), bis (p-aminocyclohexyl) methanddecanoamide. Further, in the present invention, a copolymer of two or more of the above polymers may be used. Alternatively, it may be a blend of two or more blends of the above polymers, but is not limited thereto.

In the present invention, a polyamide resin having a melting point of 210 ° C. or lower is preferable, and
Copolymerized polyamide resins based on nylon, 6,6 nylon are particularly desirable. As such polyamide resin, 6 / 6,6 copolymer nylon, 6/12 copolymer nylon, 6,6 / 12 copolymer nylon, 6 / MXD-6 copolymer nylon, 6,6 / MXD-6 copolymer Nylon etc. are illustrated. The reason why the melting point of the polyamide resin is 210 ° C. or less is that when the polyamide resin is used as a continuous phase (matrix) and the thermoplastic polyurethane resin is used as a dispersed phase (domain) for polymer alloying, the melt viscosity of the polyurethane is changed to the polyamide resin. Compared to polyamide resin, the dependence of melt viscosity on processing temperature is much more likely to change, but it is necessary to make it as high as possible, so when making a difference in melt viscosity between them (increasing the melt viscosity of polyurethane) The processing temperature should be as low as possible. The processing temperature of polyurethane resin is 210
If the temperature is above or above ℃, the decomposition will occur rapidly, and the melt viscosity will be extremely reduced, and the polyurethane resin will become a matrix, making it difficult to obtain the desired resin properties (gasoline vapor permeability resistance, heat resistance, etc.). is there.

Next, the thermoplastic polyurethane resin which is the component (B) used in the present invention is a polymer having a polyurethane bond formed by a polyaddition reaction of an organic isocyanate and an active hydrogen compound, and a diisocyanate and a polyol are used as raw materials. Further, it is a block copolymer synthesized by a chain extender, and by combination, polymers having various properties can be obtained. The structure of the thermoplastic polyurethane resin is composed of a soft segment composed of a polymeric glycol having an average molecular weight of 300 to 6,000, a monomolecular chain extender constituting a hard segment, and a diisocyanate having a carbon number of 4 to 21, depending on the type of the soft segment polyol. It can be roughly classified into polyester type, polyether type and polycarbonate type, and in the present invention, polyester type and polycarbonate type are preferable.

As the polyester type, there are aliphatic saturated dicarboxylic acids having 4 to 21 carbon atoms as an acid component, such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, etc. The group dicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid, and adipic acid is commonly used. As the diol component, an aliphatic or alicyclic compound having 2 to 21 carbon atoms, such as ethylene glycol,
There are propylene glycol, trimethylene glycol, butane diol, methyl pentane diol, pentane diol, hexane diol, heptane diol, octane diol, nonane diol, decane diol, dodecane diol, etc. Butane diol is commonly used. . There are such ester-based polymers such as polyethylene adipate, polybutylene adipate, polymethylpentane adipate, polynonane adipate, polynonane isophthalate and copolymers thereof,
Generally, polybutylene adipate is often used. Other polyester-based materials include lactone-based materials such as polycaprolactone and polycarbonic acid-based materials. As the polyether type, polytetramethylene ether glycol and the like are often used. As the chain extender, an aliphatic or alicyclic compound diol having 2 to 21 carbon atoms is used, and butanediol is generally often used.

Hardness of thermoplastic polyurethane (Shore A)
There is about 60 to 100, but since the composition of the present invention is intended to lower the elastic modulus, the hardness of the thermoplastic polyurethane resin used is preferably lower, preferably 90A or less. Is better to use. Further, it is preferable that the melt viscosity of the thermoplastic polyurethane is high (the MFR value is low), because when the polyamide resin and the thermoplastic polyurethane are alloyed with a polymer blend to form the polyamide resin into a matrix, the melt viscosity of the thermoplastic polyurethane resin is high. Is because it is advantageous that the melt viscosity is higher than the melt viscosity of the polyamide resin. As a method of increasing the melt viscosity of the thermoplastic polyurethane, a method of increasing the molecular weight or a method of partially crosslinking can be adopted.

Since the thermoplastic polyurethane resin has a good compatibility with the polyamide resin, it is not necessary to modify the compatibilizing agent or the thermoplastic polyurethane resin, but in the case where the compatibility needs to be improved, a known method, for example, The thermoplastic polyurethane may be acid-modified with an unsaturated dicarboxylic acid represented by maleic anhydride or an anhydride thereof to be used.

In the present invention, it is preferable that the components (A) and (B) satisfy the following formula (1).

[Chemical 3]

[Wherein MFR (A) is the MFR value of the component (A) of the processing temperature during processing, and MFR (B) is
The MFR value of the (B) component of the processing temperature during processing is φ
_A represents the weight% of the component (A) with respect to the total weight of the components (A) and (B)] Here, the MFR value is a value measured according to the regulations of JIS K 7210 under the following conditions. . Load: 2160 g Measurement temperature: Processing temperature of the resin composition, that is, a temperature 10 to 15 ° C. higher than the melting point of the component (A). In the present invention, the weight ratio of the component (A) and the component (B) and the MFR value are represented by the above formula. If it is adjusted so as to satisfy (1), even if the weight ratio of the component (B) in the composition is large, the polyamide is always in the continuous phase, so that excellent gasoline resistance and oil resistance can be obtained. It is possible to provide a flexible molded product while keeping it.

The polyamide resin composition of the present invention contains a reinforcing agent, a crystal nucleating agent, a releasing agent, a flame retardant, a light or heat stabilizer, a plasticizer, an antistatic agent, and a coloring agent according to various uses and purposes. Etc. can be added. Examples of the reinforcing agent include fibrous reinforcing agent and filler-like reinforcing agent.The fibrous reinforcing agent includes carbon fiber and glass fiber, and the filler-like reinforcing agent includes talc, mica, wollastonite, calcium carbonate and various whiskers. , Silica, kaolin, montmorillonite, clay and the like, but are not limited thereto. The addition amount of the reinforcing agent is about 50 parts by weight based on 100 parts by weight of the total amount of the polyamide resin and the thermoplastic polyurethane resin.
Up to parts by weight can be added.

Examples of crystal nucleating agents include, but are not limited to, talc, clay, calcium carbide, sodium phenylphosphinate, alumina, and finely ground polytetrafluoroethylene. The crystal nucleating agent can be added up to about 3 parts by weight based on 100 parts by weight of the total amount of the polyamide resin and the thermoplastic polyurethane resin.

As the release agent, a metal salt of stearic acid,
Metal salt of montanic acid wax, stearyl alcohol,
Examples include, but are not limited to, silicone oil. The release agent can be added up to about 2 parts by weight based on 100 parts by weight of the total amount of the polyamide resin and the thermoplastic polyurethane resin.

As the flame retardant, halogen type flame retardants, non-halogen type flame retardants and the like can be used without particular limitation. Of these, a mixture of a halogen-based flame retardant and antimony trioxide is preferable. Examples of the halogen-based flame retardant include brominated polystyrene, polybromodiphenyl ether, and polymeric brominated epoxy resin, and examples of the non-halogen flame retardant include melamine cyanurate and red phosphorus. The flame retardant can be added up to about 35 parts by weight based on 100 parts by weight of the total amount of the polyamide resin and the thermoplastic polyurethane resin.

As the light or heat stabilizer, carbon black, a mixture of copper halide and potassium halide,
Examples thereof include hindered phenol-based stabilizers, phosphorus-based stabilizers, benzotriazole-based stabilizers, benzophenone-based stabilizers, and mixtures thereof, but are not limited thereto. The amount of light or heat stabilizer added is 100 total of polyamide resin and thermoplastic polyurethane resin.
Up to about 4 parts by weight can be added to the parts by weight.

As the plasticizer, dioctyl phthalate, benzyl phthalate, butylbenzyl phthalate, hydrocarbon oil, Nn-butylbenzenesulfonic acid amide, o-tolueneethylsulfonamide, p-tolueneethynesulfonamide, etc. However, the present invention is not limited to these. The plasticizer can be added up to about 40 parts by weight based on 100 parts by weight of the total amount of the polyamide resin and the thermoplastic polyurethane resin.

The method for obtaining the polyamide resin composition of the present invention is not particularly limited, that is, a conventional mixing device such as a roller kneader, a Banbury mixer, a single-screw or multi-screw extruder or the like is used. It may be kneaded and molded at a temperature higher than the melting point of (A) by about 5 ° C. or more.

As described above, the composition of the present invention having such a constitution can be obtained by a conventional molding method such as injection molding or extrusion molding, in which a tank such as a gasoline tank or an oil tank which is particularly required to have gasoline resistance and oil resistance. It is preferably molded as a tube, such as gasoline tubes,
Used. Further, it is also suitably used for applications in which water absorption dimension change is a problem among parts used for home appliances, sundries, automobiles, and the like. Further, it is also suitably used for ski boots, wheel caps, bumpers, emblems and the like, which require good decorative properties such as painting. There is no particular limitation on the method for producing these molded products, and they are molded by a method known per se.

[0023]

EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

The various physical properties and test results listed in the examples were measured as follows. -MFR value: According to JIS K7210 (measurement conditions:
Load 2160g). -Hardness (Shore A): According to ASTM D-2240. -Tensile elastic modulus: according to ASTM D-638. -Matrix determination, dispersed phase particle size: JIS No. 3 tensile dumbbell cross-sectional morphology in RuO4. Judgment was performed using a transmission electron microscope (× 10,000) by PTA staining ultrathin section method.

Gasoline vapor permeation resistance: (A) Method for preparing test piece (thin film) Synergy SF type hydraulic press (manufactured by Shinto Metal Industry Co., Ltd.)
The temperature is set to 15 ° C. higher than the melting point of the polyamide resin constituting the composition to be tested. Pellets or molded articles of the composition to be tested are placed in a mold having a thickness of 0.2 mm, which is sandwiched with Teflon sheets and sandwiched with iron plates. This is put into the above press machine (pressure is not applied) and held for 1 minute, and pressure is gradually applied while bleeding air to 100 Kg / cm ² . After maintaining the pressed state for about 10 seconds, the pressure is removed to obtain a thin film (test piece) having a thickness of 0.2 mm. (B) Gasoline vapor resistance (g · mm / m ² · day · a
tm) Put about 2/3 of the internal volume of gasoline in a brass container, seal with a test piece, and fix with a screw. This was left in an oven controlled at 40 ± 1 ° C. for 4 days, after which the reduced gasoline weight was measured, and the gasoline vapor permeability was calculated by the formula (2).

[Chemical 4] [In Formula (2), D is gasoline vapor resistance (permeation coefficient).
, T is the film thickness (mm) of the test piece, Q is the reduction amount of gasoline weight (g / day), and S is the area of the test piece in contact with gasoline vapor (m ² ). Note that t is measured using a caliper to two decimal places. Q is decimal point 3
Measured to the digit. ]

Hydrolysis resistance: JIS No. 3 tensile dumbbell is dipped in warm water at 95 ° C. for 60 days and then vacuum-dried at 80 ° C. for 2 days to remove the water absorption in the tensile dumbbell. The rate (%) was evaluated. ◯: Retention rate 50% or more ×: Retention rate less than 50% Releasability: The following injection molding machine was used to evaluate the ease of mold release of the molded product. Molding machine used = Nissei Plastic Industry FS-75 type, injection time = 10 sec, cooling time = change, cylinder setting temperature = 1 from the melting point of the polyamide resin
0 ° C higher temperature Mold temperature = room temperature, molded product shape = flat plate (10
0mm x 100mm x 2mm Side guard) Judgment of releasability ○ mark: Continuous molding is possible without any problems within 10 seconds of cooling time x mark: Pinched molded product deformed due to defective release within 10 seconds of cooling time It is impossible to perform continuous molding due to the possibility of mold release.

Examples 1 to 20 and Comparative Examples 1 to 15 Polyamide resins [component (A)] shown in Tables 1 to 5;
The thermoplastic polyurethane [(B) component)] is shown in Table 1 to Table 4.
Each were mixed in a weight ratio shown in, using 30 mm ² screw extruder (Ikegai Tekko), Examples 1 to 8 and Comparative Examples 1 to 10
Then, at a temperature 10 ° C. higher than the melting point (190 ° C.) of the component (A), in Tables 9 in Examples 9 to 12 and Comparative Examples 11 to 13.
At the temperature shown in Examples 13 to 16 and Comparative Example 1
Nos. 4 and 15 were kneaded and processed at 200 ° C., respectively. The screw rotation speed was 80 rpm. However, in Examples 17 to 20, compositions were obtained in the same manner as in Example 5.
Each of the obtained compositions was discharged from an extruder, cooled in a water tank, cut with a cutter, vacuum-dried at 80 ° C. × 16HR, molded into 2 mm × 2 mm pellets, and the physical properties of each pellet were measured. . The results are shown in Tables 1 to 5.

[0028]

[Table 1]

[0029]

[Table 2] In Table 2, PA: 6 / 6,6 copolymer nylon, melting point 190 ° C. TPU: (T-1080): polyester type caprotype thermoplastic polyurethane (Dani Nippon Ink Co., Ltd., Pantex T-1080) surface hardness 80A , MFR = 1
1 g / 10 min (200 ° C.) (E-580F): polyester type caprotype thermoplastic polyurethane (Takeda Badesh Co., Ltd., Elastollan E580F) surface hardness 80A, MFR = 3.1 g / 1
0 minutes (200 ℃)

[0030]

[Table 3] In Table 3, Ny6,6: 6,6 nylon Toyobo Co., Ltd.
T-662 MXD-6: Polymeta-xylylene adipamide Toyobo Co., Ltd. T-600 Ny-6: 6 Nylon Toyobo Co., Ltd.
Manufactured by T-802 Ny6 / 6,6 copolymer: 6 nylon / 6,6 nylon (80/20 weight ratio) copolymer Ny6 / 12 copolymer: 6 nylon / 12 nylon (7
5/25 weight ratio) Ny12: 12 Nylon Daicel Huls Co., Ltd. L
-1801 T-1080: Pantex T-1 of Dainippon Ink and Chemicals, Inc.
080 (Polyester type caprotype surface hardness 80
A) E-580F: Takeda Badesh Elastollan E5
80F (Polyester type capro type surface hardness 80
A)

[0031]

[Table 4]

[0032]

[Table 5]

[0033]

As is clear from Tables 1 to 5, the composition of the present invention in which the polyamide resin forms the continuous phase has good gasoline permeation resistance and releasability. In order to make the polyamide resin a continuous phase, the amount of each compound, MFR
There are various factors such as the ratio and the type of resin, and it can be seen that the surface hardness of the thermoplastic polyurethane has an effect on lowering the tensile modulus. The composition of the present invention having such a constitution has a low elastic modulus and has excellent gasoline vapor permeation resistance, and therefore, for example, when it is used as a gasoline hose, it does not require a special coupler at its joint. There are various advantages such as joining, which greatly contributes to the industrial world.

Claims (5)

[Claims] 1. A composition containing a polyamide resin (A) and a thermoplastic polyurethane resin (B), wherein the polyamide resin (A) forms a continuous phase and the thermoplastic polyurethane resin (B) forms a dispersed phase. A polyamide resin composition, wherein the tensile modulus of the composition is 7,000 kg / cm ² or less. 2. A composition containing a polyamide resin (A) and a thermoplastic polyurethane resin (B), wherein the polyamide resin (A) forms a continuous phase and the thermoplastic polyurethane resin (B) forms a dispersed phase. And a polyamide resin composition satisfying the following formula (1). [Chemical 1] [Wherein MFR (A) is the MFR value of the polyamide resin (A) at the processing temperature during processing, MFR (B) is the MFR value of the thermoplastic polyurethane resin (B) at the processing temperature during processing, φ _A represents the weight% of the polyamide resin (A) with respect to the total of the polyamide resin (A) and the thermoplastic polyurethane resin (B)] 3. The total amount of the polyamide resin (A) and the thermoplastic polyurethane resin (B) is 100 parts by weight, and the content of the polyamide resin is 60 to 20 parts by weight, and the content of the thermoplastic polyurethane is 40 to 80 parts by weight. The polyamide resin composition according to claim 1, which is 4. The polyamide resin composition according to claim 1, wherein the melting point of the polyamide resin is 210 ° C. or lower. 5. A molded product molded from the polyamide resin composition according to claim 1.