JPH07278417A - Polyester resin composition and its production - Google Patents

Abstract

PURPOSE:To obtain a polyester resin composition which can give a lightweight molding having good surface appearance and mechanical properties. CONSTITUTION:This resin composition is prepared by mixing 100 pts.wt. resin component comprising 97-20 pts.wt. thermo-plastic polyester resin, 3-80 pts.wt. olefinic copolymer modified with a compound having a C-C double bond and an epoxy group in the molecule and 0-65 pts.wt. olefinic (co)polymer other than the above modified olefinic copolymer with 0.5-20 pts.wt. phenoxy resin and 0-150 pts.wt. filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition containing a polyolefin resin and a method for producing the same, and provides a molding composition which is lightweight and has good surface condition and mechanical properties.

[0002]

2. Description of the Related Art In recent years,
The weight reduction of automobile parts is required to improve fuel efficiency.
Also, in electric / electronic devices, weight reduction of these parts is required for easy handling such as carrying. As one means for reducing the weight, attempts have been made to use materials having a low specific gravity for parts, and thermoplastic polyester is also required to have a low specific gravity without impairing its excellent characteristics. Attempts have been made to reduce the weight by blending a small polyolefin resin with a thermoplastic polyester. However, since the polyester and the polyolefin resin have poor compatibility, even if they are simply melt-kneaded, the dispersibility of both is poor and they exist as large particles,
A resin composition that can be practically used has not been obtained because it is likely to separate on the surface of a molded product and peel off easily, and mechanical properties such as toughness are deteriorated. As a method for improving the compatibility between the polyester and the polyolefin resin, for example, JP-A-61-60
Japanese Patent No. 744 and Japanese Patent Laid-Open No. 61-60746 have been reported. The former is a method of improving compatibility by using a copolymer composed of an epoxy group-containing ethylene or an ethylenically unsaturated compound, and the latter is further using a modified polypropylene. However, even if these methods are used, the compatibility and dispersibility are not always sufficient, and further improvement is desired. The present invention solves the above-mentioned problems in the resin composition of the polyester resin and the polyolefin resin, and provides a molding material which is lightweight and has a good surface condition, and which is excellent in various physical properties such as mechanical properties. The purpose is to

[0003]

Means for Solving the Problems As a result of intensive studies to solve these problems, the present inventors have found that a modified olefin resin modified with a specific epoxy compound during melt-kneading of a thermoplastic polyester resin and a polyolefin resin. By using a copolymer and a phenoxy resin, the compatibility and dispersibility of the thermoplastic polyester resin and the polyolefin resin are improved, and the disadvantages such as peeling of the surface of the molded product are generated without substantially impairing the excellent properties of the polyester resin. It has been found that a polyester resin composition having a good surface condition and mechanical properties of a molded product can be provided without any problem, and the present invention has been completed. That is, the present invention comprises (A) 97 to 20 parts by weight of a thermoplastic polyester resin and (B) 3 to 80 parts by weight of a modified olefin copolymer modified with a compound having a carbon double bond and an epoxy group in the molecule. And (B ') 0.5 to 20 parts by weight of (C) phenoxy resin and (D) filling with respect to 100 parts by weight of a resin component consisting of 0 to 65 parts by weight of an olefin-based polymer or copolymer other than (B) A polyester resin composition characterized by containing 0 to 150 parts by weight of a material, and at least (A),
A method for producing a thermoplastic polyester resin composition, which comprises melt-kneading by heating for 30 seconds or more in the coexistence of components (B) and (C).

Each component of the present invention will be described below.
The thermoplastic polyester resin of component (A) used in the present invention includes terephthalic acid, naphthalenedicarboxylic acid, 4,4-diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, α, β-bis (4-carboxyphenoxy) as a constituent component. Dicarboxylic acids such as ethane, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, dimer acid and their ester derivatives, and ethylene glycol, propylene glycol, butanediol, pentanediol, neopentyl Glycol, hexanediol, octanediol, decanediol, cyclohexadimethanol, hydroquinone, bisphenol A,
A thermoplastic polyester resin obtained from glycols such as 2,2-bis (4′-hydroxyethoxyphenyl) propane, xylene glycol, polyethylene glycol, polytetramethylene glycol, and aliphatic polyester oligomers having hydroxyl groups at both ends. It may be a homopolyester or a copolyester. As a comonomer component for constituting a copolyester, glycolic acid, hydroxy acid, hydroxybenzoic acid, hydroxyphenoxyacetic acid, hydroxycarboxylic acid such as naphthyl glycolic acid, lactone compound such as propiolactone, butyrolactone, caprolactone, and valerolactone. Can also be used, and branched using a polyfunctional ester-forming component such as trimethylolpropane, trimethylolethane, pentaerythritol, trimellitic acid, trimesic acid, and pyromellitic acid as long as the thermoplasticity can be maintained. Alternatively, it may be a polyester having a crosslinked structure. In addition, halogens are added to aromatic nuclei such as dibromoterephthalic acid, tetrabromoterephthalic acid, tetrachloroterephthalic acid, 1,4-dimethyloltetrabromobenzene, tetrabromobisphenol A, ethylene or propylene oxide adduct of tetrabromobisphenol A. Also included are halogen-containing polyester copolymers having a compound as a substituent and using a compound having an ester-forming group. These thermoplastic polyester resins
As the component (A), one type or a mixture of two or more types can be used. Particularly preferred polyester resins are polyethylene terephthalate, polybutylene terephthalate, and polymers and copolymers containing these as main repeating units (for example, 60% by weight or more, preferably 70% by weight or more), which form a copolymer. Particularly preferable examples of the comonomer component include isophthalic acid, bisphenol A, 2,2-bis (β-hydroxyethoxyphenyl) propane, and 2,2-bis (β-hydroxyethoxytetrabromophenyl) propane.

The present invention is characterized in that a modified olefin copolymer modified with a compound having a carbon double bond and an epoxy group in the molecule is added to the polyester resin (A) as the component (B). . Examples of the compound having a carbon double bond and an epoxy group in the molecule (hereinafter abbreviated as bifunctional epoxy compound) include allyl glycidyl ether,
Glycidyl acrylate, glycidyl methacrylate,
Vinyl benzoic acid glycidyl ester, allyl benzoic acid glycidyl ester, N-diallylaminoepoxypropane, cinnamic acid glycidyl ester, cinnamylidene acetic acid glycidyl ester, chalcone glycidyl ether, epoxyhexene, dimer acid glycidyl ester, epoxidized stearyl alcohol and acrylic acid or Examples thereof include esters of methacrylic acid and compounds represented by the following general formula [I].

[0006]

[Chemical 2]

(Wherein R ₁ , R ₂ and R ₃ are hydrogen atoms or alkyl groups) Particularly preferred are compounds represented by the general formula [I]. One example thereof is N- [4- (2,3-epoxypropoxy). ) −
An example is 3,5-dimethylbenzyl] acrylamide. These bifunctional epoxy compounds may be one kind,
Also, two or more kinds can be used in combination. The modified olefin-based copolymer blended as the component (B) is an olefin-based copolymer obtained by copolymerizing the above-mentioned bifunctional epoxy compound in the main chain or side chain. The preparation of such a modified olefin copolymer (B) is not particularly limited, but, for example,
The above 2 with the olefin polymer or monomer
It is obtained by heating and reacting a functional epoxy compound in the presence of a suitable catalyst. Further, the olefin polymer constituting the modified olefin copolymer of the component (B) is specifically high density polyethylene, medium density polyethylene, low density polyethylene, polypropylene, polybutene-1, poly-3 methylbutene-1, Poly-4-methylpentene-1
And ethylene-α-olefin polymers, or copolymers of two or more kinds of ethylene and α-olefins, dienes such as butadiene and isoprene, and particularly preferably polyethylene containing ethylene as a main constituent. , Polypropylene mainly composed of propylene, ethylene-propylene copolymer, or ethylene
Examples include propylene / diene copolymers. The modified olefin-based copolymer (B) can be prepared by subjecting these olefin-based polymers and the above-mentioned difunctional epoxy compound to heat-melt kneading in the presence of a suitable catalyst. Further, it can also be prepared by directly copolymerizing the above-exemplified polyolefin-constituting monomers and a bifunctional epoxy compound. The modified olefin copolymer (B) may be any of a copolymer, a terpolymer and a block copolymer containing a small amount of a cross-linking agent or other modifier, and the molecule is not only linear but also has a branched or cross-linked structure. And the degree of polymerization thereof is not particularly limited, and may be any as long as it is thermoplastic and has melt processability. The ratio of each component constituting the modified olefin-based copolymer (B) is not particularly limited, but the above-mentioned difunctional epoxy compound is added to the above-mentioned olefin-based polymer.
0.5 to 50% by weight, preferably 2 to 40% by weight may be added for modification.

As the resin component in the present invention, a polyolefin resin other than the above-mentioned modified olefin copolymer (B), that is, various polyolefin resins (B 'not modified with the above-mentioned bifunctional epoxy compound). ) May be used in combination with (B). In particular, it is preferable to use a polyolefin resin having a low melt viscosity as the component (B ') together with the component (B) in order to obtain a resin composition having a well-balanced toughness and moldability such as injection molding. Examples of the polyolefin resin (B ′) include ethylene and α-olefin polymers such as polyethylene, polypropylene, polybutene-1, poly-3methylbutene-1, poly-4-methylpentene-1, or two or more kinds. Examples thereof include copolymers with dienes such as ethylene and α-olefin, butadiene and isoprene.

The modified olefin copolymer (B) and
By blending the olefin polymer (B ') other than (B) with the phenoxy resin (C) component described below together with the polyester resin (A), their compatibility and dispersibility are improved, and impact resistance and A polyester resin composition molded article having an excellent surface condition can be obtained, but when an olefin-based copolymer having a low elastic modulus is used, the rigidity may be remarkably lowered, and its use is limited depending on the application, which is not preferable. In many cases. Therefore, it is more preferable to use an olefin resin having a flexural modulus of 5000 kg / cm ² or more, because a polyester resin composition having a good balance of impact resistance, rigidity and surface condition can be obtained.

The blending amounts of the components (A), (B) and (B ') are
[(A) + (B) + (B ')] 100 parts by weight, the component (A) is
The lower limit is at least 20 parts by weight, preferably 30 parts by weight or more, particularly preferably 50 parts by weight or more, and the upper limit is 97 parts by weight, preferably 95 parts by weight, particularly preferably 85 parts by weight. The component (B) has a lower limit of at least 3 parts by weight, preferably 5 parts by weight, particularly preferably 15 parts by weight, and an upper limit of 80 parts by weight, preferably 70 parts by weight,
It is particularly preferably 50 parts by weight. If the (A) component becomes too large and the (B) component becomes too small, the specific gravity of the resin composition becomes large, and conversely, if the (A) component becomes too small and the (B) component becomes too large, the heat distortion temperature will rise. And deterioration of mechanical properties such as toughness are not preferable. The component (B ') is not necessarily required to be blended, but since this component is generally inexpensive,
From the viewpoint of the cost of the composition, it may be preferable to substitute a part of the component (B) and use it in combination, but an increase of the component (B ') causes a problem in compatibility and dispersibility, so that it is 65 parts by weight or less. It is preferably 40 parts by weight or less. 3 in consideration of economical efficiency
-40 parts by weight is preferred.

Next, the resin composition of the present invention is characterized by blending a fexoxy resin as the component (C). Take
(C) component phenoxy resin (A) and (B) component, further
By blending together with the component (B ') and melt-kneading, it has the effect of significantly improving the compatibility and dispersibility with the components (A) and (B) and further the component (B'). Play an important role in achieving the purpose. The phenoxy resin as the component (C) is a polycondensation product of epichlorohydrin and bisphenol A or its induced resistance, and is a substance having a structure represented by the following general formula [II].

[0012]

[Chemical 3]

(In the formula, X _{1 to} X ₈ are hydrogen atoms, C ₁ to C ₄ alkyl groups such as methyl group and ethyl group, and halogen atoms such as chlorine and bromine, and are the same or different. N is 20 or more, preferably 70 or more.) The phenoxy resin (C) suitably used in the present invention is derived from epichlorohydrin and bisphenol A or its brominated bisphenol A, and has the general formula [ II] is a polymer in which n is 70 or more. Such phenoxy resin
(C) can be produced by subjecting bisphenol A or a nuclear substitution product thereof and epichlorohydrin to a condensation reaction in the presence of an alkali typified by caustic soda. This manufacturing method is described, for example, in US Pat. No. 2,602,075 or 305,528. The content of the phenoxy resin as the component (C) is 100 parts by weight in total of the components (A), (B) and (B '), and the lower limit is at least 0.5 parts by weight, preferably 2 parts by weight. And the upper limit is 20 parts by weight, preferably 15 parts by weight or less. If this amount is too small, the effect of improving the compatibility and dispersibility of the resin composition will be insufficient and the effect of improving the toughness will be small, and if it is too large, the chemical resistance and mechanical properties of the composition will be impaired. Not preferable.

Next, the filler of the component (D) used in the present invention is not always an essential component, but a molded product excellent in performance such as mechanical strength, heat resistance, dimensional stability, and electrical properties is required. In order to obtain it, it is preferable to mix. For this purpose, a fibrous, powdery, plate-like, or hollow filler is used depending on the purpose. As the fibrous filler, glass fiber, asbestos fiber, carbon fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber,
Examples thereof include boron fibers, potassium titanate fibers, and inorganic fibrous substances such as metal fibrous substances such as stainless steel, aluminum, titanium, copper, and brass. Among them, typical fibrous substances are glass fiber and carbon fiber. Examples of the granular filler include carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, silicates such as wollastonite, iron oxide, titanium oxide. , Oxides of metals such as alumina, calcium carbonate, magnesium carbonate,
Such as metal carbonates, calcium sulfate, barium sulfate,
Examples of such metal sulfates include silicon carbide, silicon nitride, boron nitride, and various metal powders. Examples of the plate-like filler include mica, glass flakes, various metal foils and the like. Further, examples of the hollow filler include glass balloons and shirasu balloons. These fillers can be used alone or in combination of two or more, and the fibrous filler such as glass fiber and the powdery or plate-like filler are preferably used in combination. The compounding amount of the filler (D) is 150 parts by weight or less, preferably 80 parts by weight or less with respect to 100 parts by weight of the total of the components (A), (B) and (B '). In many cases, the lower limit is preferably 5 parts by weight or more. If the component (D) is too large, the moldability and toughness are impaired, which is not preferable. or,
If it is too small, the heat distortion temperature, rigidity, mechanical properties, etc. tend to deteriorate, which is not preferable for some applications.

In the present invention, antioxidants, heat stabilizers, lubricants, crystal nucleating agents, ultraviolet absorbers, colorants, release agents, and other usual additives are included within the scope of the present invention. Can be blended. Further, a small amount of other thermoplastic resin, for example, a polycarbonate resin, a polyamide resin, a polystyrene resin, a polyvinyl chloride resin or the like can be supplementarily added.

The polyester resin composition of the present invention can be prepared by various known methods.
(A), (B), under the coexistence of the (C) component, further add the (B ') component, and if necessary, also the (D) component, and heat-melt,
It is necessary to perform melt-kneading treatment for 30 seconds or more. Specifically, for example, each component of (A), (B), (C), and further (B ') and / or (D)
The components are also used together and previously mixed uniformly with a mixer such as a tumbler or a Henschel mixer, and then fed to a uniaxial or biaxial extruder or the like and melt-kneaded to produce pellets. The component (D) may be added during or after the melt-kneading process. The kneading temperature is 10 than the melting temperature of the resin components.
℃ to 100 ℃ higher temperature, preferably 10 ℃ to 60 ℃
It is a high temperature. If the temperature is too high, the resin may be decomposed or an abnormal reaction may be caused, which is not preferable. Also, the kneading treatment time varies depending on the treatment temperature and the type and blending amount of each component,
It is at least 30 seconds and 15 minutes, preferably 1 minute and 10 minutes. The thermoplastic polyester resin composition of the present invention is suitable for molding molded articles of various shapes by various molding methods such as injection molding, extrusion molding, blow molding, vacuum molding and compression molding.

[0017]

As is apparent from the above description and examples, the thermoplastic polyester resin composition of the present invention has excellent compatibility and dispersibility of each component, improved mechanical properties, and is lightweight.
It is possible to provide a molded product having a good appearance without causing surface peeling or the like.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Reference Example: Preparation of Modified Olefin Copolymer (B) [AXE Modified Polypropylene (B-1a, B-1b, B-1c)] Polypropylene (PP) (Sumitomo Chemical Co., Ltd. Noblen D
501) 100 parts by weight, 10 parts by weight of N- (4- (2,3-epoxypropoxy) -3,5-dimethylbenzyl) acrylamide (AXE: manufactured by Kaneka Chemical Industry Co., Ltd.) and 2 as a radical initiator 0.15 parts by weight of 5,5-di (t-butylperoxy) hexane was added to PP and premixed with a Henschel mixer for 5 minutes.
The mixture was melt-kneaded with an extruder at ℃ to prepare pellets of AXE-modified polypropylene (B-1a). B-1a has a flexural modulus of 1
It was 2800 kg / cm ² . Pellets were prepared in the same manner when the amount of AXE was 5 parts by weight or 1 part by weight, and these were designated as B-1b and B-1c, respectively. B-1b and B-1c
The elastic modulus of each was 12700 kg / cm ² . [AXE-modified polyethylene (B-2)] AXE-modified polyethylene was prepared in the same manner as in B-1 except that polyethylene (PE) (HiZex 2200J manufactured by Mitsui Petrochemical Co., Ltd.) was used in place of PP of B-1a. (B-2) was produced. B-
The flexural modulus of 2 was 12000 kg / cm ² . [GMA-modified polyethylene (B-3)] GMA-modified polyethylene (B-) was prepared in the same manner as in Reference Example 2 except that AXE of B-2 was replaced with glycidyl methacrylate (GMA).
3) (Bending elastic modulus 11700 kg / cm ² ) was prepared. [AXE-modified ethylene / propylene copolymer (B-4)]
B-1a PP is ethylene / propylene copolymer (EPR)
(EP912P manufactured by Nippon Synthetic Rubber Co., Ltd.)
An AXE-modified ethylene / propylene copolymer (B-4) was produced in the same manner as in B-1a. [AXE modified ethylene / ethyl acrylate copolymer (B-5)] PP of B-1a is ethylene / ethyl acrylate copolymer (EEA) (EEA D manufactured by Nippon Unicar Co., Ltd.)
An AXE-modified ethylene / ethyl acrylate copolymer (B-5) was produced in the same manner as in B-1a except that PDJ-9169) was used.

Examples 1 to 7 and Comparative Examples 1 to 6 (A) Polybutylene terephthalate resin (PBT) (Duranex manufactured by Polyplastics Co., Ltd.) (70 parts by weight) was added to the modified PP (B-1a) prepared as described above. ) And (C) Phenoxy resin (Phenoxy resin manufactured by Union Carbide Co., Ltd.
PKHH) was added in an amount shown in Table 1, and in some cases (B ') polypropylene, and further (D) glass fibers (chopped strands having a diameter of 10 μm and a length of 3 mm) were simultaneously added and premixed for 5 minutes with a Henschel mixer. Cylinder temperature 260
The mixture was melt-kneaded with an extruder at ℃ (residence time about 1.5 minutes) to prepare pellets of the polyester resin composition. Next, the pellets were molded into ASTM test pieces by an injection molding machine under the conditions of a cylinder temperature of 260 ° C. and a mold temperature of 60 ° C., and subjected to a tensile test and an impact test (ASTM D-638 and D-25.
6). Further, using the tensile test piece, a cellophane tape peeling test was performed under certain conditions, and the peeling state of the surface was also evaluated.

For comparison, the same evaluation was carried out for the case where the unmodified PP (B) was not used and only the unmodified PP (B ') was used, and the case where the (C) phenoxy resin was not used.
The results are summarized in Table 1. Examples 8 to 9 and Comparative Examples 7 to 9 Using the above PBT resin (A) and modified PP (B-1a), at the ratios shown in Table 2, pellets were prepared in the same manner as in Examples 1 to 6 described above. Was prepared and evaluated. The specific gravity was also measured.
The results are shown in Table 2. Examples 10 to 15 and Comparative Examples 10 to 15 Using the modified polyolefin resins of B-2 to B-5 as the component (B) of Examples 2 and 7, pellets were prepared in the same manner as in Examples 2 and 7 described above. Was prepared and evaluated. The results are shown in Table 3 and Table 4.
Shown in. Examples 16 and 17 Using B-1b and B-1c instead of B-1a as the component (B) of Example 2, pellets were prepared and evaluated in the same manner as in Example 2. The results are shown in Table 5.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

[0025]

[Table 5]

Claims (9)

[Claims] 1. A thermoplastic polyester resin (A) in an amount of 97 to 20 parts by weight, and (B) a modified olefin-based copolymer modified in a molecule having a carbon double bond and an epoxy group in an amount of 3 to 80 parts by weight. (B ') Based on 100 parts by weight of a resin component consisting of 0 to 65 parts by weight of an olefin-based polymer or copolymer other than (B)
(C) Phenoxy resin 0.5 to 20 parts by weight and (D) Filler 0 to
A polyester resin composition comprising 150 parts by weight. 2. The polyester resin composition according to claim 1, wherein the thermoplastic polyester resin (A) is a polyester polymer or copolymer mainly composed of polybutylene terephthalate or polyethylene terephthalate. 3. The polyester resin composition according to claim 1, wherein the modified olefin copolymer (B) is a modified olefin copolymer modified with a compound represented by the following general formula [I]. [Chemical 1] (However, R ₁ , R ₂ , and R ₃ are hydrogen atoms or alkyl groups) 4. The modified olefin copolymer (B) and the olefin (co) polymer (B ') other than (B) have a flexural modulus of 5000 kg / cm ² or more. Or 1
The polyester resin composition according to the item. 5. A polyolefin (co) polymer other than (B)
The polyester resin composition according to any one of claims 1 to 4, wherein the blending amount of (B ') is 3 to 40 parts by weight. 6. The filler (D) is any one selected from fibrous fillers, powder fillers, plate fillers and hollow fillers.
The polyester resin composition according to claim 1, which is a species or a mixture thereof. 7. The polyester resin composition according to claim 6, wherein the fibrous filler (D) is glass fiber. 8. Among the respective components according to any one of claims 1 to 7, in the presence of at least (A), (B) and (C) components, 30
A method for producing a thermoplastic polyester resin composition, which comprises melt-kneading with heating for at least 2 seconds. 9. Melting under heating for 30 seconds or more in the coexistence of at least the components (A), (B), (B '), and (C) among the components shown in any one of claims 1 to 7. A method for producing a thermoplastic polyester resin composition, which comprises kneading.