JP2680099B2 - Method for producing heat-resistant resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition having good moldability and excellent heat resistance and mechanical properties.

[Prior Art] With the recent development of the automobile industry and the electric / electronic industry, the demand for engineering plastics has increased, while the environment in which the equipment incorporating plastics is used has become severe. Therefore, there are new demands for functions and characteristics that conventional resins cannot meet.

On the other hand, aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate are excellent in workability and formability, and have good mechanical properties, electrical properties, chemical resistance, etc. Widely used for parts and electric / electronic parts.

However, even in the field where general-purpose engineered plastics are used in recent years, stricter usage conditions are often imposed than in the past (for example, improvement of impact resistance under high temperature), and improvement and modification thereof are required. .

As a method of modifying two types of polymers having characteristics in moldability and physical properties of molded products so as to make the best use of their respective characteristics,
There is a technology of polymer blend.

Among them, polyphenylene ether, which has excellent heat resistance and hydrolysis resistance but poor moldability, and a machine at high temperature, which has good moldability but uses heat resistant resin. Of aromatic polyesters, which are required to have improved mechanical properties or mechanical properties at low temperatures, have also been proposed by modification by blending.

For example, a vinyl-based polymer having a reactive functional group with a polyester at one or both ends of a styrene main chain as shown in JP-A-62-131015, which is a so-called "macromer", is used. As disclosed in JP-A-63-15841 and JP-A-63-95256, a method of blending a copolymer of vinyl polymer and polyester and polyphenylene ether, and further JP-A-63-20357. A resin composition prepared by blending a copolymer of vinyl polymer and polyester, polyphenylene ether and polyester is shown.

Further, JP-A-63-500387 proposes to simultaneously blend a polyphenylene ether and a polyester with a block copolymer of a polycarbonate and a polystyrene end block and a butadiene mid block.

However, even with this improved technique, the mechanical strength such as moldability and impact resistance is not sufficient. Therefore, as a result of intensive studies in order to sufficiently satisfy the mechanical strength such as moldability and impact resistance, it was found that it is effective to improve the dispersed state of the composition, and the present invention was reached. .

[Object of the Invention] An object of the present invention is a resin composition that utilizes polyphenylene ether and an aromatic polyester copolymer and has uniform dispersibility, and has good moldability, and the molded product has impact resistance. To provide a resin composition having excellent heat resistance and heat resistance.

[Structure of the Invention] The present invention provides (A) a polyphenylene ether-based resin, (B) a polyester composed of an aromatic dicarboxylic acid component and a glycol component, and a derivative of an aromatic vinyl-based polymer, and the aromatic dicarboxylic acid component. 30-70% by weight,
In producing a resin composition composed of three components of a polymerized copolyester and (C) an aromatic polyester,
After thoroughly mixing the two resin components (A) and (B) in a weight ratio (A) / (B) of 85/15 to 15/85, the resin component (C) is added. And then mixing,
It is a method for producing a heat resistant resin composition having a uniform dispersion state.

The "polyphenylene ether resin" (A) used in the present invention generally has a repeating unit represented by the following formula (I), n1 is an integer of 50 or more, and R _{1 to} R ₄ are substituents selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group such as a methyl group and an ethyl group, or a halogenated hydrocarbon group. .

According to the preferred polymer, R ₃ and R ₄ have 1 to 4 carbon atoms.
Alkyl groups, and R ₁ and R ₂ are polymers of hydrogen atoms. As an example of this, poly-2,6-diethyl-1,4-
Examples thereof include phenylene ether, poly-2,6-dipropyl-1,4-phenylene ether, poly-2,6-dimethyl-phenylene ether, and poly-2,6-dimethyl-
Most preferred is phenylene ether.

In addition, the "copolyester" used in the present invention
(B) means to copolymerize an aromatic vinyl polymer (30 to 37% by weight with respect to the aromatic dicarboxylic acid component) in the polycondensation reaction of the aromatic dicarboxylic acid component and the diol component. It is a condensation-reactive polyester copolymer having the polyester block and the aromatic vinyl polymer block obtained as described above as constituent components.

Examples of the "aromatic dicarboxylic acid component" used herein include dicarboxylic acids having a benzene nucleus such as terephthalic acid and isophthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, and naphthalene-2. , 7
-Dicarboxylic acids having a naphthalene nucleus such as dicarboxylic acids or their ester-forming derivatives.
Instead of the aromatic dicarboxylic acid or its ester-forming derivative, 20 mol% or less of the acid component other than the aromatic dicarboxylic acid, for example, adipic acid, sebacic acid or their ester-forming derivatives can also be used.

Examples of the “diol component” include aliphatic glycols such as ethylene glycol, tetramethylene glycol, hexamethylene glycol, diethylene glycol and cyclohexanedimethanol, 1,4-bisoxyethoxybenzene, diols having an aromatic ring such as bisphenol A, or Examples thereof include ester-forming derivatives. Further, terephthalic acid is particularly preferable as the acid component, and ethylene glycol or tetramethylene glycol is particularly preferable as the dimethylene glycol or glycol component.

Examples of the "aromatic vinyl polymer" include polymers obtained from styrene, vinyltoluene, α-methylstyrene, nuclear halogenated styrene, vinylnaphthalene, etc. in the case of the same monomer, and particularly styrene. Are preferred. The "aromatic vinyl polymer" may be a block copolymer obtained by combining the above-mentioned styrene polymer and aliphatic diene polymer.

Examples of the aliphatic diene-based polymer include diene-based polymers such as butadiene and isoprene. In this copolyester, the aromatic vinyl polymer is allowed to coexist in an amount of 30 to 70% by weight based on the aromatic dicarboxylic acid. Need to be polymerized. If the copolymerization ratio is less than 30%, (A)
"Uniform dispersion state" even if the composition ratio of the polyphenylene ether resin and the (B) copolymerized polyester and the composition ratio of the (C) aromatic polyester to be added later are changed over a wide range.
Is not obtained and a composition having sufficient mechanical strength cannot be obtained. The term "uniformly dispersed state" as used herein means that the resin composition after blending is sandwiched by a cover glass for optical microscope observation, and has a thickness (10 to 50) observable with an optical microscope.
(A), (B) and (C) in the sample having a size of 10 μm or more, that is, a state in which a domain of 10 μm or more as shown in the photograph of FIG.
It refers to the state where each component cannot be distinguished as shown in the photograph in the figure.

Further, when an attempt is made to cause a polycondensation reaction of 70% or more of an aromatic vinyl polymer with respect to the aromatic dicarboxylic acid in the presence of the aromatic dicarboxylic acid component and the diol component, the polycondensation reaction does not proceed sufficiently and Polymerized polyester cannot be obtained.

Further, the number average molecular weight of the "aromatic vinyl polymer" here is preferably 600 to 12000 in terms of styrene-equivalent molecular weight of gel permeation chromatography, and 1000 to 6000.
Is particularly preferred. When an aromatic vinyl polymer having a number average molecular weight of 1200 or more is used for the copolyester, the flicker of the aromatic vinyl polymer block is too large for the polyester block. Even if the same weight% of the group dicarboxylic acid component is used, the number average molecular weight of the aromatic vinyl polymer is 12000 or more, compared with the case of using 3000, the frequency of being located in the copolyester is Since it becomes smaller], a uniform dispersed state and preferable mechanical strength cannot be obtained. On the contrary, even when an aromatic vinyl polymer having a small number average molecular weight of less than 600 is used, uniform dispersibility and preferable mechanical strength cannot be obtained, probably because the repeating units of the copolyester are small and fragmented.

The method for producing the copolyester can be carried out by a conventional and well-known polymerization method. That is, an "aromatic vinyl polymer" having a terminal functional group capable of polycondensation reaction is added at an arbitrary stage of esterification or transesterification of an aromatic dicarboxylic acid or its dimethyl ester and a diol to conduct an esterification or transesterification reaction. After completion of step 1, the polycondensation reaction is completed under high vacuum.

In addition, the composition ratio when mixing the resins (A) and (B) must be a weight ratio of (A) / (B) of 85/15 to 15/85, in the range of 60/40 to 40/60. Is particularly preferable.
In the case of (A) / (B)> 85/15, the ratio of the polyphenylene ether resin (A) is too high, so that the aromatic polyester (C) to be added later has a bad influence. The effect does not appear.

When (A) / (B) <15/85, finally, sufficient heat resistance cannot be obtained.

In addition, the "aromatic polyester" used in the present invention
(C) is a polyester having an aromatic group in the main chain of the polymer, and is a polymer or copolymer obtained by a condensation reaction containing an aromatic dicarboxylic acid or its ester-forming derivative and a diol or its ester-forming derivative as main components. It is a polymer.

"Aromatic dicarboxylic acid" and "diol" here
As the component, those similar to the aromatic dicarboxylic acid component and the diol component described in the above "Copolyester" (B) can be used, and preferred examples of the aromatic polyester include polyethylene terephthalate, polybutylene terephthalate and polyhexamethylene. Terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalate and the like, polybutylene terephthalate and polyethylene terephthalate are the most preferable, 1,1,2,2-tetrachloroethane and phenol 2: 3 mixed solvent It is preferable that the intrinsic viscosity determined from the solution viscosity obtained by measuring at 35 ° C. is in the range of 0.5 to 2.0 dl / g.

The "mixing order" of the resins (A), (B) and (C) is such that it is necessary to sufficiently mix the resin (A) and the resin (B) and then add and mix the resin (C). Even when the compositions of (A), (B), and (C) are the same, when they are mixed at the same time, or when the resin (A) and the resin (C) are mixed and then the resin (B) is added and mixed. Does not provide a uniformly dispersed state, and as a result, a resin composition having sufficient mechanical strength cannot be obtained.

Further, as the "mixing" of the resin in the present invention, any method for mixing a usual solid substance, for example, a method using a Banbury mixer, a single screw or twin screw extruder can be applied, and a method using a twin screw extruder is particularly preferable. Hereinafter, a suitable “mixing” method will be described with reference to the drawings. FIG. 1 illustrates a "mixing" process utilizing a twin screw extruder suitable for practicing the present invention. That is, in FIG. 1, the resin (A) and the resin (B) are charged from the supply port 2 of the twin-screw extruder 1, sufficiently mixed in the melt mixing section 3, and then the resin (C) is post-added from the supply port 4. Then, further mixing is performed in the mixing section 5 in the second stage, and the mixture is discharged from the discharge section 6. It is also possible to install a granulator in the discharge part for granulation.

Here, the ratio of the resin (C) in the composition is 10 times or less of the total amount of the resin (A) and the resin (B), that is, the weight ratio is c / (a +
b) <10 (where a, b, and c are the resin (A) in the composition,
The weight is preferably in the range of (B) and (C).
When the resin (C) is added beyond this range, the heat resistance becomes insufficient.

EFFECTS OF THE INVENTION The resin composition produced by the method of the present invention has significantly improved moldability as compared with the case of blending polyphenylene ether alone or polyphenylene ether and aromatic polyester. Compared with the case where the polyester is used alone or the aromatic polyester and the polyphenylene ether are blended, the dispersed state is improved, and the impact resistance, mechanical strength and heat resistance of the molded product are improved.

That is, it is effective as a resin composition having well-balanced heat resistance, moldability, impact resistance, etc., and can be used for automobiles, electric / electronic parts, etc. used under severe conditions.

[Examples] The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples. In the following, all "parts" are based on weight. The heat resistance evaluation method and impact strength were measured by the following devices and methods.

1. Heat drooping Effective length (not including gripping length) 100mm, Thickness 3mm, Width 50mm
Hold the strip-shaped test piece of
After standing for 1 hour in an atmosphere of 0 ° C., the amount (mm) of the tip of a 100 mm long blade hanging from the horizontal position from the supporting position was measured.

2. Impact strength Shown as Izod impact strength (with V notch) of ASTM D256 at room temperature.

Reference Example 1 Dimethyl terephthalate 28 parts, 1,4-butanediol 18
Part, tetrabutoxytitanium 0.02 part as a catalyst and 14 parts of a derivative of a styrene polymer having a polycondensation-reactive hydroxyl group at both ends (number average molecular weight 2,900) are charged into the transesterification tank to complete the transesterification reaction. After that, a polycondensation reaction was subsequently carried out to obtain a polymer having an intrinsic viscosity [η] = 1.2.

Reference Example 2 A copolyester was produced under the same conditions as in Reference Example 1 except that 5.6 parts of the styrene polymer derivative of Reference Example 1 was used.

Reference Example 3 An attempt was made to produce a copolyester in the same manner as in Reference Example 1 except that 21 parts of the styrene polymer derivative of Reference Example 1 was used, but the reaction did not proceed sufficiently, and a polymer was obtained. There wasn't.

Example 1 Using the flow chart shown in FIG. 1, the copolyester prepared in Reference Example 1 from the pellet feeder 8 and having a number average molecular weight of about 10
2,000 poly-2,6-dimethyl-1,4-phenylene ether and 10 kg / h (total 20 kg / h) each from the feed port 2
The mixture was supplied to the axial extruder and thoroughly mixed in the mixing section 3. Furthermore, to the position of the supply port 4 of this mixture, polybutylene terephthalate resin pellets of [η] = 1.20 were supplied from the pet supply device 9 in an amount of 20 kg / h, and after further mixing them in the mixing section 5, the discharging section 6 More discharged.

The thread discharged from the device was cooled and cut to obtain molding pellets. The degassing port 7 can also be used if necessary, but it was not used in this example.

Next, the pellets were dried with hot air at 130 ° C for 5 hours, and then the injection molding machine JSW-N40B II manufactured by Japan Steel Works, Ltd. was used to prepare a test piece for a thermal droop amount test piece and a Izod impact strength (with V notch) test piece. Each mold is installed and the cylinder temperature is 29
Molded under the conditions of 0 ℃, mold temperature 90 ℃, injection pressure 1000Kg / cm ² . Furthermore, the amount of heat droop and the Izod impact strength of each sample were measured.

Comparative Example 1 The procedure of Example 1 was repeated except that the copolyester prepared in Reference Example 2 was used.

Comparative Example 2 Using the flow of FIG. 1, in Example 1, the supply port 4
The poly (butylene terephthalate) resin having [η] = 1.20, which has been further charged, is also supplied to the twin-screw extruder 1 through the supply port 2 at the same time as the copolyester and the polyphenylene ether prepared in Reference Example 1, and the supply port 4 is not used. Other than that, it carried out on the conditions similar to Example 1.

Comparative Example 3 Using the flow of FIG. 1, polyphenylene ether resin and polybutylene terephthalate resin with [η] = 1.20 were supplied from the supply port 2 at a rate of 10 kg / h and 20 kg / h, respectively, and the reference example was supplied from the supply port 4. 10Kg of the copolyester prepared in 1
The same procedure as in Example 1 was carried out except that the material was supplied and used at a ratio of / h.

Comparative Example 4 The procedure of Example 1 was repeated except that the amounts of the copolyester and the polyphenylene ether resin supplied from the supply port 2 were changed to 2 kg / h and 18 kg / h.

Comparative Example 5 The procedure of Example 1 was repeated except that the amounts of the copolyester and the polyphenylene ether resin supplied from the supply port 2 were changed to 18 kg / h and 2 kg / h.

The results of Example 1 and Comparative Examples 1 to 5 described above are summarized in Table 1. Further, optical microscope photographs of the compositions of Example 1 and Comparative Example 2 showing typical dispersion states are shown in FIGS. 2 and 3. It can be clearly seen that FIG. 2 is uniformly dispersed as compared with FIG.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a twin-screw extruder suitable for carrying out the present invention. Further, FIGS. 2 and 3 are optical micrographs showing an example of the present invention and a comparative example, respectively. 1 ... Twin-screw extruder, 2,4 ... Supply port, 3,5 ... Mixing section, 6 ...
Discharge part, 7 ... Degassing port, 8, 9 ... Pellet supply device.

Claims (1)

(57) [Claims] 1. A polyester containing an aromatic dicarboxylic acid component and a glycol component (A) a polyphenylene ether resin, and a derivative of an aromatic vinyl polymer to 30 parts of the aromatic dicarboxylic acid component. ~ 70% by weight,
In producing a resin composition composed of three components of a polymerized copolyester and (C) an aromatic polyester,
After thoroughly mixing the two resin components (A) and (B) in a weight ratio (A) / (B) of 85/15 to 15/85, the resin component (C) is added. And then mixing,
A method for producing a heat resistant resin composition having uniform dispersibility.