JP2001261945A - Polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic polyester resin composition having an impact strength improved by a smaller amount of a rubber component without damaging the excellent characteristics such as rigidity and heat resistance originally possessed by the thermoplastic polyester. SOLUTION: This polyester resin composition contains (B) a silicone-based graft copolymer having 0.3-1.0 μm average particle diameter dispersed in (A) a thermoplastic polyester resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyester resin composition having excellent impact resistance.

[0002]

2. Description of the Related Art Thermoplastic polyesters represented by polybutylene terephthalate and polyethylene terephthalate have excellent workability, mechanical properties, and other physical and chemical properties, and are therefore used in automobile parts, electric and electronic equipment parts. Are widely used in the field of precision instrument parts, but their impact strength is low, so that their improvement is desired.
There are many proposals for improving the impact strength of a thermoplastic polyester resin.
The method of blending a silicone / acrylic composite rubber grafted with a vinyl monomer having an epoxy group described in No. 41113 is a relatively excellent method.

[0003] However, this method has a drawback in that when a rubber is added in an amount necessary to obtain a high impact strength, excellent properties such as rigidity and heat resistance inherent in thermoplastic polyester are impaired.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to improve the impact strength with a smaller amount of a rubber component in order to maintain excellent properties such as rigidity and heat resistance inherent in thermoplastic polyester. is there.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the impact strength can be improved by optimizing the dispersion size of rubber and / or crystallization of the thermoplastic polyester resin. And improved the impact strength with a small amount of the rubber component, leading to the present invention.

The gist of the present invention is a polyester resin composition in which a silicone-based graft copolymer (B) having an average particle size of 0.3 to 1.0 μm is dispersed in a thermoplastic polyester resin (A). Further, there is provided a polyester resin composition comprising at least a thermoplastic polyester resin (A) and a silicone-based graft copolymer (B), wherein the crystalline lamella of the thermoplastic polyester resin (A) is oriented. Further, a fluoropolymer-containing mixed powder comprising a fluoropolymer (C) and an organic polymer is blended with a resin composition comprising a thermoplastic polyester resin (A) and a silicone-based graft copolymer (B). And a method for producing a polyester resin composition, which comprises a step of melt-mixing.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermoplastic polyester resin (A) used in the present invention includes terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, diphenylether dicarboxylic acid, α, β One or more dicarboxylic acids such as bis- (4-carboxyphenoxy) ethane, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, and dimer acid, and ester-forming derivatives thereof; And ethylene glycol, propylene glycol, butanediol, pentanediol, neopentyl glycol, hexanediol, octanediol, decanediol, cyclohexanedimethanol, hydroquinone, bisphenol A, 2,2-bis (4'- (Doxyethoxyphenyl) propane, xylene glycol, polyethylene ether glycol, polytetramethylene ether glycol, glycols selected from one or more of aliphatic polyester oligomers having both ends hydroxyl groups by polycondensation reaction It is a polyester resin obtained and may be either a homopolyester or a copolyester. Other than the above, as comonomer components for composing the copolyester, glycolic acid, hydroxy acid, hydroxybenzoic acid, hydroxyphenylacetic acid, hydroxycarboxylic acid such as naphthyl glycolic acid, propiolactone, butyrolactone, caprolactone, valerolactone Such a lactone compound can also be used, and a polyfunctional ester such as trimethylolpropane, trimethylolethane, pentaerythritol, trimellitic acid, trimesic acid, or pyromellitic acid can be formed as long as thermoplasticity can be maintained. A polyester having a branched or crosslinked structure using components may be used. Also, aromatic nuclei such as dibromoterephthalic acid, tetrabromoterephthalic acid, tetrachloroterephthalic acid, 1,4-dimethyloltetrabromobenzene, tetrabromobisphenol A, and ethylene or propion oxide adducts of tetrabromobisphenol A are halogenated. A polyester copolymer having a halogen using a compound having a compound as a substituent and having an ester-forming group is also included. Further, a polyester elastomer constituting a block copolymer of a high melting point hard segment and a low melting point soft segment can also be used. Examples of the polyester elastomer include a block copolymer of a hard segment mainly composed of an alkylene terephthalate unit and a soft segment composed of an aliphatic polyester or polyether. These thermoplastic polyester resins can be used alone or as a mixture of two or more as the component (A).

[0008] Particularly preferred thermoplastic polyester resins are polybutylene terephthalate, polyethylene terephthalate and copolymers having these as main repeating units, and the comonomer components forming the copolymer are particularly preferably isophthalic acid and bisphenol. A, 2,2-bis (β-hydroxyethoxyphenyl)
And propane and 2,2-bis (β-hydroxyethoxytetrabromophenyl) propane.

The silicone graft copolymer (B) used in the present invention is a copolymer obtained by graft-polymerizing at least one vinyl monomer onto a rubber-like polymer containing an organic silicone polymer. It is.

Examples of the rubbery polymer containing an organosilicone polymer include a polymer containing an organosiloxane unit, a copolymer containing an organosiloxane unit, and a silicone / acrylic material containing an organopolysiloxane and a polyalkyl (meth) acrylate. Composite rubber and the like can be mentioned. Among these, silicone / acryl composite rubber is preferred. As a form of composite rubber,
It can be in a form in which both components are mixed and dispersed almost uniformly, a form in which acrylic rubber is dispersed in silicone in a salami structure, a form in which silicone and acrylic rubber are layered, and a mixture of these forms. It may be. Examples of the alkyl (meth) acrylate used for the composite rubber include methyl acrylate, ethyl acrylate,
n-propyl acrylate, n-butyl acrylate,
Examples thereof include alkyl acrylates such as 2-ethylhexyl acrylate; alkyl methacrylates such as hexyl methacrylate, 2-ethylhexyl methacrylate, and n-lauryl methacrylate, and use of n-butyl acrylate is particularly preferable. The rubbery polymer referred to here is a polymer that is rubbery at room temperature, and preferably has a glass transition temperature of −20 ° C. or less. These rubbery polymers are produced by emulsion polymerization, solution polymerization, suspension polymerization, bulk polymerization and the like. The particle size and gel content of the rubbery polymer in the case of production by emulsion polymerization are not particularly limited, but preferably have an average particle size of 0.01 to 1 μm and a gel content of 0 to 95%.

Examples of the vinyl monomers graft-polymerized to a rubber-like polymer containing a silicone polymer include methacrylates such as methyl methacrylate and 2-ethylhexyl methacrylate; and acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate. Aromatic alkenyl compounds such as styrene, halogen-substituted styrene, α-methylstyrene and vinyltoluene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; and glycidyl methacrylate and glycidyl as vinyl monomers containing an epoxy group. Acrylate, vinyl glycidyl ether, allyl glycidyl ether, glycidyl ether of hydroxyalkyl (meth) acrylate, polyalkylene glycol (meth) acrylate Glycidyl ethers of, may be exemplified glycidyl itaconate. Among these, an epoxy group-containing vinyl monomer is preferable, and glycidyl methacrylate is particularly preferable. These may be used alone or in combination of two or more.

In the present invention, the average particle diameter of the silicone graft copolymer (B) in the resin composition is 0.3.
To 1.0 μm, and preferably 0.3 to 0.7 μm. When the average particle size is less than 0.3 μm, or
If it exceeds 0 μm, sufficient impact strength cannot be obtained.

The average particle size of the silicone graft copolymer (B) is, for example, about 80 n with a microtome after immersing the resin composition in an aqueous solution of ruthenium tetroxide, washing with water and drying.
By cutting out an ultrathin section having a thickness of m, evaluation can be performed with a transmission electron microscope (TEM). That is, the area of each particle of the silicone-based graft copolymer (B), which is observed as being dispersed in the obtained TEM image, is measured, and this is converted into the diameter of a circle having the same area, and the diameter of the dispersed particle is measured. An average particle size is determined.

As described above, the average particle size of the silicone-based graft copolymer (B) represents the dispersion size of the silicone-based graft copolymer (B) in the thermoplastic polyester resin (A). . Therefore, when the particles are dispersed as primary particles, the average particle diameter of the primary particles is obtained. When the fine primary particles are aggregated to form the secondary particles, the average value of the secondary particle diameter is obtained.

In the present invention, the silicone-based graft copolymer (B) is preferably used in an amount of 1 to 20% by mass in the resin composition. When added in an amount exceeding 20% by mass, excellent properties such as rigidity and heat resistance inherent in the thermoplastic polyester are liable to be impaired, and it is suitable for the purpose of the present invention to improve the impact strength with a small amount of rubber component. Hateful. If the addition amount is less than 1% by mass, the impact strength tends to be insufficiently improved.

In order to disperse the silicone-based graft copolymer (B) in the resin composition with the above-mentioned average particle size, for example, a master batch containing the silicone-based graft copolymer (B) at a high concentration is used. It is possible to use a method of forming and diluting this with a thermoplastic polyester resin and molding, or a method of changing kneading conditions at the time of melt molding. The thermoplastic resin used in the masterbatch is not particularly limited, and any thermoplastic resin that can be used in the resin composition of the present invention, such as a polyolefin resin, a polystyrene resin, a polyester resin, a polyamide resin, a polycarbonate resin, and an ABS resin. Can be used.
On the other hand, for kneading at the time of melt molding, a usual kneader such as a roll, a Banbury mixer, a single screw extruder, or a twin screw extruder can be used. Graft copolymer (B)
Can be dispersed with the above-mentioned average particle size.

Furthermore, the silicone graft copolymer (B) can be dispersed with the above-mentioned average particle size by adding a fibril-like fluoropolymer (C) as shown below at the time of molding.

In the present invention, fibrils mean fine fibrils. Therefore, the present invention is not limited to the fine fibers forming the fibers, but includes those present in the polymer material as aggregated or dispersed. Usually, the diameter of the fibrils is preferably 100 nm or less,
Some fibrils having a diameter exceeding 100 nm may exist, but it is preferable that the number of fibrils is one or less per 50 fibrils. More preferably 50 nm or less, and 5
It is preferable that the number exceeding 0 nm is one or less per ten fibrils.

For such a fibril-like fluoropolymer (C), first, a fluoropolymer-containing mixed powder composed of fluoropolymer particles and an organic polymer is prepared. It is obtained by adding it to a product. At this time, in the fluoropolymer-containing mixed powder, it is preferable that the fluoropolymer is dispersed as finely as possible as fine particles as possible. It is preferable to produce the aqueous dispersion of fluorine-based polymer particles having a diameter of 0.05 to 1.0 μm by the following methods (a) to (c). (A) A method of mixing an aqueous dispersion of a fluorine-based polymer particle and an aqueous dispersion of an organic-based polymer particle to form a powder by coagulation or spray drying. (B) A method of polymerizing a monomer constituting an organic polymer in the presence of an aqueous dispersion of fluorine-based polymer particles and then pulverizing the polymer by coagulation or spray drying. (C) Emulsion polymerization of a monomer having an ethylenically unsaturated bond in a dispersion obtained by mixing an aqueous dispersion of fluoropolymer particles and an aqueous dispersion of organic polymer particles, followed by coagulation or spray drying. How to embody.

The coagulation can be carried out by a conventional method such as putting the aqueous dispersion into hot water in which a metal salt such as calcium chloride or magnesium sulfate is dissolved and salting out.

The term "fluoropolymer" as used in the present invention refers to fluororubber and fluororesin containing fluorine in the molecule.
The fluoropolymer used in the present invention is not particularly limited as long as it can be in the form of fibrils, and polytetrafluoroethylene, polychlorotrifluoroethylene,
Examples include polyvinyl fluoride, vinylidene fluoride resin, hexafluoropropylene-tetrafluoroethylene copolymer, chlorotrifluoroethylene-vinylidene fluoride copolymer, and among others, polytetrafluoroethylene is preferably mentioned. it can.

The aqueous dispersion of polytetrafluoroethylene particles having a particle diameter of, for example, 0.05 to 1.0 μm, which is used to obtain a mixed powder containing a fluorine-containing polymer, is prepared by emulsion polymerization using a fluorine-containing surfactant. Obtained by polymerizing a monomer. At the time of emulsion polymerization of polytetrafluoroethylene particles, as long as the properties of polytetrafluoroethylene are not impaired, hexafluoropropylene, chlorotrifluoroethylene, fluoroalkylethylene, perfluoroalkylvinylether and other fluorinated olefins as copolymerization components And a fluorine-containing alkyl (meth) acrylate such as perfluoroalkyl (meth) acrylate. The content of the copolymer component is 10% by mass based on tetrafluoroethylene.
The following is preferred.

Commercially available raw materials for the polytetrafluoroethylene particle dispersion include Fluon AD-1 and AD-936 manufactured by Asahi Glass Fluoropolymer; Polyflon D-1 and D-2 manufactured by Daikin Industries; and DuPont Mitsui Fluorochemicals. Teflon 30J manufactured by the company can be cited as a representative example.

The organic polymer constituting the fluorine-containing polymer-containing mixed powder is not particularly limited, but preferably has a high affinity with the thermoplastic polyester resin from the viewpoint of dispersibility. .

Specific examples of the monomer for forming the organic polymer include styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene, t-butylstyrene, o-ethylstyrene, and p-methylstyrene. Aromatic vinyl monomers such as chlorostyrene, o-chlorostyrene, 2,4-dichlorostyrene, p-methoxystyrene, o-methoxystyrene, 2,4-dimethylstyrene; methyl acrylate, methyl methacrylate, acrylic Ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate,
2-ethylhexyl acrylate, methacrylic acid-2-
(Meth) acrylic ester monomers such as ethylhexyl, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate; acrylonitrile, methacrylonitrile Vinyl cyanide monomers such as maleic anhydride; α, β-unsaturated carboxylic acids such as maleic anhydride; maleimide monomers such as N-phenylmaleimide, N-methylmaleimide, N-cyclohexylmaleimide; glycidyl methacrylate Epoxy group-containing monomers such as vinyl methyl ether and vinyl ethyl ether; vinyl ether monomers such as vinyl acetate and vinyl butyrate; ethylene and propylene;
Olefin monomers such as isobutylene; diene monomers such as butadiene, isoprene, and dimethylbutadiene; These monomers can be used alone or in combination of two or more.

Among these monomers, from the viewpoint of affinity with the thermoplastic polyester resin, preferred are aromatic vinyl monomers, (meth) acrylate monomers, and vinyl cyanide monomers. 1 selected from the group consisting of multimers
Monomers containing at least 30% by mass of at least one kind of monomer can be mentioned. Particularly preferred are styrene,
Examples include a monomer containing 30% by mass or more of one or more monomers selected from the group consisting of methyl methacrylate and acrylonitrile. The content ratio of the fluoropolymer in the fluoropolymer-containing mixed powder used in the present invention is preferably 0.1 to 90% by mass.

Since ordinary polytetrafluoroethylene fine powder forms aggregates of 100 μm or more in the step of recovering as a powder from the state of a particle dispersion, it is difficult to uniformly disperse it in a thermoplastic resin. is there. In contrast, the fluoropolymer-containing mixed powder used in the present invention has a fluoropolymer content of 0.05 to 1.0 μm.
m, and the organic polymer acts as a dispersing aid, so that the dispersibility in a thermoplastic resin is extremely excellent. As a result, in the polyester resin composition of the present invention, in order for the fluoropolymer to efficiently fibrillate in the polyester resin, the dispersion size of the silicone graft copolymer changes, and the effect of improving impact strength is expressed,
It also has excellent surface properties.

Further, the fibril-like fluorine-based polymer acts as a nucleating material for crystallization during melt molding, and has an effect of promoting crystallization of the polyester resin. At this time, since the fibril-like fluoropolymer is oriented in the flow direction of the resin, the polyester resin is oriented and crystallized. Normally, polyester resin can be easily oriented and crystallized by elongation stress in extrusion molding or blow molding, but higher-order structures such as spherulites are formed in molding methods that do not easily apply elongation stress such as injection molding or thermoforming. You. Such a high-order structure impairs the development of impact strength, and it is preferable not to form a high-order structure in the resin composition. In the composition of the present invention, since the fluorine-based polymer is easily fibrillated and oriented by a slight shear stress or an extensional stress, it is possible to orient the crystal of the polyester resin, to suppress the formation of a higher-order structure and to obtain an impact strength. Express the improvement effect.

The reason that the fluoropolymer acting as a nucleating material for crystallization is preferably in the form of fibrils is because the polyester resin is crystallized from the surface of the fluoropolymer, so that it is difficult for crystals to grow three-dimensionally. It is thought that it is. Further, it is preferable that the fibrils of the fluoropolymer be as thin as possible and have a large number. It is considered that by increasing the number of fibrils, the gap between adjacent fibrils becomes narrower, and three-dimensional crystal growth of the polyester resin can be suppressed.

The crystal orientation of the polyester resin can be determined by, for example, immersing the composition in an aqueous solution of ruthenium tetroxide, washing with water, drying, and cutting out an ultra-thin section with a thickness of about 80 nm with a microtome. (TEM)
Can be observed. In the TEM image, the state where crystal lamellas are arranged can be observed.
The orientation state can be clarified by performing a two-dimensional Fourier analysis on the M image. The two-dimensional Fourier analysis of the TEM image can be performed, for example, by reading a TEM photograph with a scanner, converting the image into an electronic image, and using commercially available image analysis software. In the case where the crystal lamella of the polyester resin is oriented, the Fourier analysis image is observed only in a specific direction as shown in FIG. 3, whereas the case where the crystal lamella is not oriented or forms a spherulite. In the case, the Fourier analysis image is shown in FIG.
Since it does not show anisotropy in a ring shape like
The orientation of the crystal lamella can be determined.

In the present invention, the fluoropolymer (C)
Is preferably used in the range of 0.001 to 20% by mass in the resin composition. If it is added in an amount exceeding 20% by mass, the fluidity at the time of melting is significantly reduced. If the amount is less than 0.001% by mass, the effect of the addition of the fluorine-based polymer is hardly exhibited.

The resin composition of the present invention contains pigments, dyes, glass fibers, metal fibers, and the like as long as the intended purpose is not impaired.
Reinforcing agents and fillers such as metal flakes and carbon fiber, 2,6
Phenolic antioxidants such as di-butyl-4-methylphenol, 4,4'-butylidene-bis (3-methyl-6-t-butylphenol), tris (mixed, mono and dinyphenyl) phosphite, diphenyl Phosphite-based antioxidants such as isodecyl phosphite; sulfur-based antioxidants such as dilauryl thiodipropionate, dimyristyl thiodipropionate diasterial thiodipropionate; 2-hydroxy-
Benzotriazole-based ultraviolet absorbers such as 4-octoxybenzophenone and 2- (2-hydroxy-5-methylphenyl) benzotriazole;
6) light stabilizers such as -tetramethyl-4-piperidinyl), antistatic agents such as hydroxylalkylamine and sulfonate, lubricants such as ethylenebisstearylamide and metal soap, and tetrabromophenol A, decabromophenol oxide By blending various additives such as a flame retardant such as a TBA epoxy oligomer, a TBA polycarbonate oligomer, and antimony trioxide, the physical properties and characteristics can be adjusted to more desirable properties.

Further, the polyester resin composition of the present invention may contain, if necessary, a polyphenylene ether resin, a polyamide resin, a polycarbonate resin, a vinyl polymer such as polymethyl methacrylate (PMMA), a vinyl chloride resin, an ABS resin, a styrene resin. Resins, polyolefin resins such as polyethylene and polypropylene, and ethylene / propylene copolymer, ethylene / butene-1 copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 5-ethylidene-2-norbornene copolymer Coalescence, ethylene / propylene / 1,4-
By appropriately blending an olefin-based rubber such as a hexadiene copolymer, an ethylene / vinyl acetate copolymer, or an ethylene / butyl acrylate copolymer, the physical properties and properties can be further adjusted.

The polyester resin composition of the present invention is prepared by mixing a predetermined amount of each of the above-mentioned essential components and optional components as required, and using a usual kneading machine such as a roll, a Banbury mixer, a single-screw extruder, or a twin-screw extruder. , But it is usually preferable to form a pellet. Alternatively, a masterbatch containing a high concentration of the fluorine-containing polymer-containing mixed powder may be prepared, and the masterbatch may be diluted with a thermoplastic resin containing a thermoplastic resin polyester or the like to obtain the polyester resin composition of the present invention. The thermoplastic resin used in the masterbatch is not particularly limited, and any thermoplastic resin that can be used in the resin composition of the present invention, such as a polyolefin resin, a polystyrene resin, a polyester resin, a polyamide resin, a polycarbonate resin, and an ABS resin. Can be used.

The thus obtained polyester resin composition of the present invention has high rigidity and impact strength in various molding methods, and also has excellent surface properties of a molded product because there is no macroaggregate of a fluoropolymer. .

The method for processing the polyester resin composition of the present invention is not particularly limited, and examples thereof include injection molding, calender molding, blow molding, extrusion molding, thermoforming, foam molding, and melt spinning.

Useful molded articles obtained by using the polyester resin composition of the present invention are not particularly limited, and include injection molded articles, sheets, films, hollow molded articles, pipes, square bars, and the like.
Examples include irregularly shaped articles, thermoformed articles, foams, and fibers.

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these.

[0039]

EXAMPLES In each description, "parts" indicates parts by mass, and "%" indicates mass%.
And physical properties are measured by the following methods. (1) Solid concentration: determined by drying the particle dispersion at 170 ° C. for 30 minutes. (2) Particle size distribution, weight average particle size: A particle dispersion diluted with water was used as a sample solution and subjected to dynamic light scattering (ELS800, manufactured by Otsuka Electronics Co., Ltd., temperature 25 ° C., scattering angle 90 °). It was measured. (3) Zeta potential: Measured by electrophoresis (ELS800, manufactured by Otsuka Electronics Co., Ltd., temperature: 25 ° C., scattering angle: 10 °) using a sample solution prepared by diluting the particle dispersion with a 0.01 mol / l NaCl aqueous solution. did. (4) Izod impact strength: using a test piece obtained by injection molding, according to ASTM D256, a thickness of 3.2 mm,
Measured at 23 ° C. with notch. (5) Average particle size of silicone graft copolymer: A test piece obtained by injection molding was exposed, immersed in a 0.5% ruthenium tetroxide aqueous solution at room temperature overnight, and then a microtome equipped with a diamond knife. , An ultra-thin section having a thickness of about 80 nm was cut out and observed with a TEM. 10,000
The double-printed photograph was read by a scanner to obtain an electronic image, the area of each dispersed particle was determined using general-purpose image analysis software, and this was converted to the diameter of a circle having the same area to obtain the dispersion size. Here, measurement was carried out on 100 or more particles, and the average value was determined to be the average particle size. (6) Orientation state of crystal lamella of polyester resin: A test piece obtained by injection molding was exposed, immersed in a 0.5% ruthenium tetroxide aqueous solution at room temperature overnight, and then subjected to a microtome equipped with a diamond knife. An ultra-thin section having a thickness of 80 nm was cut out and observed with a TEM. 60000
The double-printed photograph was read by a scanner to obtain an electronic image, and two-dimensional Fourier analysis was performed using general-purpose image analysis software to determine the orientation as follows. ：: With orientation ×: Without orientation (7) Appearance: The surface appearance of the injection-molded test piece was visually observed and judged according to the following criteria. ：: No bumps on the surface ×: There bumps on the surface Commercially available thermoplastic polyester resins (A-1 and 2) and the substances shown in Reference Examples were used. Thermoplastic polyester resin (A-1): Polybutylene terephthalate resin (Toughpet PBTN1000, trade name, manufactured by Mitsubishi Rayon Co., Ltd.) Thermoplastic polyester resin (A-2): Polyethylene terephthalate resin (Dianite PA210, trade name,
Reference Example 1 <Production of Silicone Graft Copolymer (B-1)> 0.5 part of γ-methacryloyloxypropyldimethoxymethylsilane and 99.5 parts of octamethylcyclotetrasiloxane were mixed. Thus, 100 parts of a siloxane mixture was obtained. To this, 300 parts of distilled water in which 1 part of sodium dodecylbenzenesulfonate was dissolved was added, and the mixture was stirred with a homomixer at 10,000 rpm for 2 minutes, and then passed twice through a homogenizer at a pressure of 30 MPa to obtain a stable premixed organosiloxane latex. Obtained. On the other hand, 10 parts of dodecylbenzenesulfonic acid and 90 parts of distilled water were charged into a separable flask equipped with a condenser and a stirring blade, and 10%
Of dodecylbenzenesulfonic acid was prepared. While the aqueous solution was heated to 85 ° C., the premixed organosiloxane latex was added dropwise over 2 hours, and after the addition was completed, the temperature was maintained for 3 hours and then cooled. The reaction was then kept at room temperature for 12 hours and neutralized with aqueous sodium hydroxide.

The thus obtained latex L-1
Was dried at 170 ° C. for 30 minutes to obtain a solid content.
18.1%. The number average particle size of the latex was 32 nm.

55.2 parts of the silicone latex L-1 was collected, placed in a separable flask equipped with a stirrer, 144.8 parts of distilled water was added, and the mixture was purged with nitrogen.
The temperature was raised to 0 ° C., and a mixed solution of 74.8 parts of n-butyl acrylate, 0.2 parts of allyl methacrylate and 0.3 parts of tert-butyl hydroperoxide was added. Then, a mixed solution of 0.001 part of ferrous sulfate, 0.003 part of disodium ethylenediaminetetraacetate, 0.2 part of Rongalit and 10 parts of distilled water was added to start radical polymerization. After holding for a time, a silicone / acrylic composite rubber latex (S-1) was obtained.

A mixture of 10 parts of methyl methacrylate and 0.05 part of tert-butyl hydroperoxide was added dropwise to this S-1 over a period of 15 minutes. The mixture was maintained at an internal temperature of 60 ° C. for 1 hour, and then 5 parts of glycidyl methacrylate and tert. A mixture of 0.025 parts of -butyl hydroperoxide was added dropwise over 8 minutes, and the mixture was maintained at an internal temperature of 60 ° C. for 2 hours to complete the graft polymerization onto the composite rubber, thereby obtaining a silicone-based graft copolymer (B-1). Latex was obtained. The number average particle diameter of B-1 latex was 71 nm.

B-1 latex was added to a 5% aqueous solution of calcium chloride at 40 ° C. so that the mass ratio of the latex to the aqueous solution was 1: 2, and then the temperature was raised to 90 ° C. to coagulate the water. After repeating the washing with, the solid content was separated and dried at 80 ° C. for 24 hours to obtain a dry powder of B-1.

Reference Example 2 <Production of Silicone Graft Copolymer (B-2)> S-1 obtained in Reference Example 1 was replaced with methyl methacrylate 10
And a mixture of 0.05 parts of tert-butyl hydroperoxide was added dropwise over 15 minutes, and the mixture was maintained at an internal temperature of 60 ° C. for 1 hour to obtain a latex of a silicone-based graft copolymer (B-2). Number average particle diameter of B-2 latex is 70 n
m.

B-2 latex was added to a 5% aqueous solution of calcium chloride at 40 ° C. so that the mass ratio of the latex to the aqueous solution was 1: 2, and then the temperature was raised to 90 ° C. to coagulate the water. After the washing was repeated, the solid content was separated and dried at 80 ° C. for 24 hours to obtain a dry powder of B-2.

Reference Example 3 <Production of Fluoropolymer-Containing Mixed Powder (C-1)> A mixture of 70 parts of dodecyl methacrylate and 30 parts of methyl methacrylate was added to 2,2'-azobis (2,4-dimethylvaleronitrile). 0.1 parts were dissolved. 2.0 parts of sodium dodecylbenzenesulfonate and 3 parts of distilled water
Add 00 parts of the mixed solution, and mix
After stirring for 4 minutes at rpm, 30MP was added to the homogenizer.
2 times at the pressure of a, stable dodecyl methacrylate /
A methyl methacrylate preliminary dispersion was obtained. This was charged into a separable flask equipped with a stirring blade, a condenser, a thermocouple, and a nitrogen inlet, the internal temperature was raised to 80 ° C. under a nitrogen stream, and the mixture was stirred for 3 hours to undergo radical polymerization, and dodecyl methacrylate / methyl A methacrylate copolymer particle dispersion (P-1) was obtained.

The solid content concentration of P-1 was 25.1%, the particle size distribution showed a single peak, and the weight average particle size was 190.
nm, and the surface potential was -39 mV.

On the other hand, as a polytetrafluoroethylene-based particle dispersion, Fluon AD manufactured by Asahi Glass Fluoropolymers Co., Ltd.
936 (trade name) was used. AD936 has a solids concentration of 63.0% and polytetrafluoroethylene 100%.
5 parts by weight of polyoxyethylene alkylphenyl ether. The particle size distribution of AD936 showed a single peak, the weight average particle size was 290 nm, and the surface potential was -20 mV.

To 833 parts of AD936, 1167 parts of distilled water was added to obtain a polytetrafluoroethylene particle dispersion (F-1) having a solid concentration of 26.2%. F-1 is 25%
Of polytetrafluoroethylene particles and 1.2% of polyoxyethylene nonylphenyl ether.

F-1 was mixed with 80 parts (polytetrafluoroethylene 20 parts) and 239.0 parts P-1 (dodecyl methacrylate / methyl methacrylate copolymer 60 parts) with a stirring blade, a condenser, a thermocouple, and nitrogen introduction. The mixture was charged into a separable flask equipped with a mouth and a dropping funnel, and stirred at room temperature for 1 hour under a nitrogen stream. Thereafter, the temperature in the system was raised to 80 ° C., and a mixed solution of 0.001 part of iron (II) sulfate, 0.003 part of disodium ethylenediaminetetraacetate, 0.24 part of Rongalite salt, and 10 parts of distilled water was added. A mixture of 20 parts of methyl methacrylate and 0.1 part of tertiary butyl peroxide was added dropwise over 30 minutes, and after completion of the addition, the internal temperature was maintained at 80 ° C. for 1 hour to complete the radical polymerization. No solid matter was separated through a series of operations, and a uniform particle dispersion was obtained. The solid content concentration of the particle dispersion was 28.6%, the particle size distribution was relatively broad, and the weight average particle size was 220 nm.

349.7 parts of this particle dispersion was poured into 600 parts of 75 ° C. hot water containing 5 parts of calcium chloride to separate a solid, which was filtered and dried to obtain a fluoropolymer-containing mixed powder (C- 1) 98 parts were obtained.

The dried C-1 was shaped into strips at 220 ° C. by a press molding machine, and ultrathin sections were observed with a microtome without staining using a transmission electron microscope.
Although polytetrafluoroethylene was observed as a dark area, no aggregate exceeding 10 μm was observed.

Reference Example 4 <Production of master batch (M-1) of silicone-based graft copolymer> A-1 and 50 parts of the silicone-based graft copolymer (B-1) obtained in Reference Example were blended. After hand blending, using a single screw extruder, the mixture was melt-kneaded at a barrel temperature of 240 ° C. and a screw rotation speed of 60 rpm, and was shaped into pellets. The silicone-based graft copolymer master batch (M-1) ) Got.

Examples 1-4, Comparative Examples 1-7 Thermoplastic polyester resin (A-1, 2), silicone-based graft copolymer (B-1, 2) or masterbatch (M-1), and fluorine The polymer-containing mixed powder (C-1) was blended at the ratio shown in Table 1 and a twin-screw extruder (W
The pellets were extruded with a screw rotation speed of 200 rpm by ERNER & PFLEIDERER (ZSK30). Next, a test piece for measuring various physical properties was prepared by an injection molding machine, and the impact strength, the average particle size of the silicone-based graft copolymer, the crystal lamellar orientation of the polyester resin,
The appearance was evaluated. Table 1 shows the results.

For comparison, a sample to which polytetrafluoroethylene fine powder (CD123, trade name, manufactured by Asahi ICI) was added was similarly evaluated. Table 1 shows the results.

The cylinder temperature of the extruder and the injection molding machine is 240 ° C. for PBT and 280 ° C. for PET.
The mold temperature was 80 ° C. for PBT and 120 ° C. for PET.

For comparison, a master batch (M-1) of a silicone-based graft copolymer was blended with the thermoplastic polyester resin (A-1) and pelletized at a screw rotation speed of 100 rpm by a twin-screw extruder. Was prepared by injection molding and similarly evaluated. The results are shown in Table 1 (Comparative Example 7).

[0058]

[Table 1]

[0059]

According to the present invention, it is possible to provide a molded article of a thermoplastic polyester resin which exhibits a high impact strength by adding a small amount of rubber and has excellent surface properties of the molded article.

[Brief description of the drawings]

FIG. 1 is a photograph substituted for a drawing of a molded product obtained from a polyester resin composition of the present invention, which is obtained by a transmission electron micrograph, in which a dispersed phase that looks white is a silicone-based graft copolymer.

FIG. 2 is a drawing substitute photograph of a molded product obtained from the polyester resin composition of the prior art (Comparative Example 2) by a transmission electron micrograph, in which the dispersed phase that looks white is a silicone-based graft copolymer.

FIG. 3 is a drawing substitute photograph by a Fourier transform image obtained from a transmission electron micrograph of a molded product obtained from the polyester resin composition of the present invention.

FIG. 4 is a drawing substitute photograph obtained by a Fourier transform image obtained from a transmission electron micrograph of a molded product obtained from a polyester resin composition according to a conventional technique.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 27:12) C08L 27:12) F-term (Reference) 4J002 BC02Z BD12Y BD13Y BD14Y BD15Y BG06Z BG10Z BN17X CF001 CF031 CF061 CF071 CF121 FA04Y FA04Z GM00 GN00 GQ00

Claims (6)

[Claims] 1. A polyester resin composition comprising a thermoplastic polyester resin (A) and a silicone-based graft copolymer (B) having an average particle size of 0.3 to 1.0 μm dispersed therein. 2. A polyester resin in which a silicone-based graft copolymer (B) having an average particle size of 0.3 to 1.0 μm and a fibril-like fluoropolymer (C) are dispersed in a thermoplastic polyester resin (A). Composition. 3. A polyester resin composition comprising at least a thermoplastic polyester resin (A) and a silicone-based graft copolymer (B), wherein the crystalline lamella of the thermoplastic polyester resin (A) is oriented. . 4. A thermoplastic polyester resin (A) in which a silicone-based graft copolymer (B) and a fibril-like fluoropolymer (C) are dispersed, and the crystalline lamella of the thermoplastic polyester resin (A) is oriented. And a polyester resin composition. 5. The method according to claim 1, wherein the thermoplastic polyester resin (A) is polybutylene terephthalate, and the silicone-based graft copolymer (B) contains an epoxy group. Polyester resin composition. 6. A fluoropolymer-containing mixed powder comprising a fluoropolymer (C) and an organic polymer in a resin composition comprising a thermoplastic polyester resin (A) and a silicone-based graft copolymer (B). And a process for melt-mixing the polyester resin composition.