JPH0429699B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester composition having excellent heat resistance, particularly solder resistance, mechanical properties, and kneading and moldability. Polyethylene terephthalate has excellent heat resistance, chemical resistance, mechanical properties, electrical properties, etc., and is useful for fibers,
It is used as a film for many purposes. In recent years, it has attracted attention as an engineering plastic due to its excellent properties, and its usage is increasing. Polyethylene terephthalate has a higher melting point and better heat resistance than polybutylene terephthalate, so attempts have been made to apply it to electrical and electronic parts, but its solder resistance is still insufficient, and its use in these fields is also limited. Therefore, there is a strong desire to improve solder resistance. The present inventors solved the above problems and, as a result of intensive research to develop a polyester composition with excellent kneadability and moldability, as well as excellent heat resistance, particularly solder resistance, and mechanical properties, the composition of the present invention was developed. reached the thing. That is, the present invention is made by blending 5 to 100% by weight of polyphenylene sulfide and 0.1 to 10% by weight of a polyoxyalkylene compound compatible with the polyester to a polyester mainly containing ethylene terephthalate repeating units. It is characterized by Polyphenylene sulfide is known as a resin with excellent heat resistance, flame retardancy, and chemical resistance, and in order to improve the processability of the resin, a composition containing a small proportion of polyester was also published in JP-A-55 −135160
It has already been disclosed in the publication No. Further, a composition in which polyphenylene sulfide is blended with a wholly aromatic polyester is also disclosed in JP-A-53-57255. However, although these compositions improve the desired processability and flow characteristics to some extent, they have the drawback of lacking uniformity in the appearance and mechanical properties of molded products. The present inventors have found that simply blending polyphenylene sulfide with polyester results in poor kneading properties, resulting in strand breakage during extrusion pellet production, resulting in markedly poor operability, and in addition, the resulting molded product has poor homogeneity of physical properties. It was found that the product had drawbacks such as being unsatisfactory. The composition according to the present invention improves the kneading properties of polyester and polyphenylene sulfide by using a specific polyoxyalkylene compound in combination, and also solves defects such as strand breakage, significantly improving workability and improving moldability. Since the uniformity of the mechanical properties and thermal properties of the molded article is improved, it is particularly useful as a molding material for electrical or electronic parts that requires further improved heat resistance and solder resistance. It also has excellent surface properties even when molded at low temperatures, heat resistance, especially solder resistance, morphological stability at high temperatures, and mechanical properties. The polyester used in the present invention is a polyester mainly containing ethylene terephthalate repeating units, and the repeating units are preferably 80 mol% or more, particularly preferably 90 mol% or more. Copolymerizable components that can be copolymerized include:
For example, isophthalic acid, naphthalenedicarboxylic acid,
Acid components such as adipic acid, sebacic acid, diphenyl ether 4,4'-dicarboxylic acid, cyclohexanedicarboxylic acid, propylene glycol, butylene glycol, diethylene glycol, neopentyl glycol, cyclohexanedimethanol, 2,2-bis(4- Examples include glycol components such as (hydroxyphenyl)propane, and oxy acids such as P-oxybenzoic acid and P-hydroxyethoxybenzoic acid. In addition, the polyester was prepared using a mixed solvent of phenol/tetrachloroethane (6/
The intrinsic viscosity determined by measuring a solution (weight ratio) at 30° C. is usually 0.4 or more, preferably 0.5 or more. Further, the polyester may be partially branched within a range that does not impair moldability, or may be a mixed polyester mainly composed of ethylene terephthalate by blending a plurality of polyesters. The polyphenylene sulfide used in the present invention is a resin whose main constituent unit is a repeating unit (-Ph-S), and preferably the constituent unit is a repeating unit (-Ph-S)-.
It is a resin having 90 mol% or more. The molecular weight is usually 1
10,000 or more, and a melting point of about 275 to 290°C is preferable. In addition, in the general formula -Ph-

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] etc., and Q is F, Cl, Br or an alkyl group, a cycloalkyl group,
Aryl group, alkaryl group, ralkyl group, etc., m
represents an integer from 1 to 4. A particularly preferred phenylene sulfide is

[Formula]. Na Oh, as a copolymer unit

【formula】

[Formula] etc. are exemplified. In the present invention, it is important to blend a polyoxyalkylene compound compatible with the polyester in order to improve the kneading properties and extrusion stability of the polyester and polyphenylene sulfide. Compounds that can be used include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyneopentyl glycol,
Polyether glycols with polyoxyalkylene chains such as ethylene oxide/propylene oxide random or block copolymers, polyhydric alcohol alkylene oxide adducts, alkylene oxide adducts of polyhydric carboxylic acids, or their monos or polyethers, mono or Compounds with an anionic group introduced at the end of a polyoxyalkylene chain such as polyesters, phthalate esters of polyether glycol, diglycolic acid esters, polyoxyalkylene phenyl ether sulfonic acid, or their metal salts, Esters made by further esterifying anionic groups with benzyl alcohol, etc., unsaturated alcohol ethers of polyether glycol, polyether compounds with unsaturated groups such as unsaturated acid esters, partially polyalkylene glycols of polymers containing carboxylic acid groups Examples include compounds having a polyoxyalkylene chain and an epoxy group, such as ester, mono- or polyglycidyl ether or mono- or polyglycidyl ester of polyether glycol. The compound preferably has at least one group reactive with polyester. Polyether glycols, such as high molecular weight compounds that improve antistatic properties, which are generally incompatible with polyester, have a poor effect on improving extrusion stability, and are also inconsistent in terms of non-uniformity in moldability and solder resistance. Appropriate. The molecular weight of the polyoxyalkylene compound used in the present invention varies depending on the type, but is usually 5000 or less, preferably 150 to 3000,
Of these, 200 to 1500 is particularly preferred. A particularly preferred polyoxyalkylene compound is a compound having a polyoxyalkylene chain and an epoxy group, or a combination of a compound that forms this compound during kneading or molding. analogy is a general expression However, A: _C1 to _C5 aliphatic hydrocarbon group, hydrogen or glycidyl group R: _C2 to _C5 aliphatic hydrocarbon group n: Polyalkylene glycol glycidyl ether represented by an integer of 2 or more. . Specifically, mono- or diglycidyl ether of polyethylene glycol,
Mono- or diglycidyl ether of polypropylene glycol, mono- or diglycidyl ether of polytetramethylene glycol, mono- or diglycidyl ether of polyneopentyl glycol, mono- or diglycidyl ether of polyethylene glycol/polypropylene glycol copolymer, polyethylene glycol/poly Examples include mono- or diglycidyl ether of tetramethylene glycol copolymer, monoglycidyl ether of methoxypolyethylene glycol, and monoglycidyl ether of ethoxypolyethylene glycol. Other than the general formula, preferred compounds include glycidyl ether of glycerin/alkylene oxide adduct and glycidyl ether of neopentyl glycol alkylene oxide adduct. However, it is not limited to these. The compound is preferably a polyglycidyl compound having an average of 1.2 to 2 epoxy groups in the molecule, and the epoxy value (number of equivalents of oxirane ring present in 100 g of the compound) is particularly preferably about 0.1 to 0.7. In the present invention, the blending ratio of the above components is 5 to 5 to 5 polyphenylene sulfide to polyester.
100% by weight, preferably 8-80% by weight. 5
If it is less than 100% by weight, the effect of improving heat resistance, especially solder resistance, will be insufficient, and if it exceeds 100% by weight, there will be disadvantages such as poor extrusion stability and poor appearance of the molded product.
On the other hand, the blending amount of the polyoxyalkylene compound is 0.1 to 10% by weight, preferably 0.5 to 10% by weight, based on the polyester. If the blending amount is less than 0.1% by weight, the kneading processability of the polyester and polyphenylene sulfide will deteriorate, making it impossible to obtain stable operability, causing strand breakage during extrusion pelletization, and making uniform blending difficult. The heat resistance, especially the solder resistance, of the molded product becomes partially non-uniform, making it difficult to achieve the objective, and it is also difficult to obtain a molded product with excellent surface properties and thermal dimensional stability using a low-temperature mold. If the content exceeds 10% by weight, mechanical properties, thermal stability over time, etc. will deteriorate. If desired, a mold release agent may be used in combination with the composition of the present invention to further improve moldability. Particularly preferred mold release agents include esters of higher fatty acids, metal salts of Group A or Group A of the periodic table of higher fatty acids, metal salts of dimer acids, polyhydric alcohol fatty acid esters such as sodium stearate, calcium stearate, magnesium stearate,
Examples include calcium montanate, montanate ester, and the like. Its blending amount is 10% for polyester.
It is not more than 0.01 to 3% by weight, preferably 0.01 to 3% by weight. Furthermore, if desired, a reinforcing agent may be added to the composition of the present invention to further improve heat resistance, moldability, and mechanical properties. Reinforcing agents that can be used are fibrous,
It is granular or a mixture of both. Examples of fibrous reinforcing agents include glass fiber, shirasu glass fiber,
Examples include inorganic fibers such as alumina fibers, silicon carbide fibers, gypsum fibers, metal fibers, and whiskers, and carbon fibers. In addition, granular reinforcing agents include talc, wollastonite, kaolin, clay,
Silicates such as sericite, mica, bentonite, asbestos, alumina silicate, metal oxides such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, carbonates such as calcium carbonate and magnesium carbonate, calcium sulfate, sulfuric acid Sulfates such as barium, glass beads, boron nitride, silicon carbide, etc.
These may be hollow. The above-mentioned reinforcing agents may be used after being treated with a coupling agent such as a silane type or titanium type, if necessary. The blending amount of these reinforcing agents is 200% by weight or less based on the polyester,
Preferably 5-150% by weight, particularly preferably 10-130%
Weight%. If the blending amount of the reinforcing agent is 200% by weight or more, the extrusion stability becomes insufficient and the surface gloss of the molded product tends to be significantly impaired. Depending on the use and purpose, the composition of the present invention may further contain stabilizers for polyester, such as antioxidants, ultraviolet absorbers, hydrolysis stabilizers, plasticizers, lubricants, sliding properties improvers, blowing agents, etc. Additives such as antistatic agents, antifouling agents, colorants, and flame retardants may also be blended. The polyester composition of the present invention may also optionally contain other thermoplastic resins in amounts and types not departing from the spirit of the present invention, such as polyolefins, polyamides, polyacetals, polycarbonates,
Polysulfone, polyphenylene oxide, etc. may be additionally blended. In addition, resins for improving impact resistance having a glass transition point of 0°C or lower, particularly preferably -20°C or lower, such as polyester elastomer, polyamide elastomer, polycarbonate elastomer, ionic group-containing olefin rubber, epoxy-modified olefin rubber, etc. They can also be blended as appropriate. The composition thus obtained has excellent moldability and surface properties when molded not only in high-temperature molds but also in low-temperature molds, and is a molded product with excellent heat resistance, especially solder resistance, and mechanical properties. Therefore, it is particularly suitable for molding parts to be soldered, such as electrical/electronic parts. Furthermore, compositions containing no reinforcing agent are useful as extrusion molding materials such as fibrous and film materials, blow molding materials, and the like. The method for producing the composition of the present invention is not particularly limited, and any method may be used. For example, the polyester and all other components are mixed in advance and made into a compound using an extruder, or the polyester and all components other than the fiber reinforcement are mixed and fed into an extruder, and the molten material is coated around glass roving, etc. The method includes the so-called wire coating method in which the wire is coated, cooled, and then cut into appropriate lengths, and a method in which a fibrous and/or granular reinforcing agent is added during or after the polymerization of the polyester, and then all other components are mixed therein. Can be mentioned. However, the mixing method and blending timing are not necessarily limited to these. The present invention will be explained below with reference to Examples. In addition,
Parts and percentages in the examples are by weight. Example 1 Polyethylene terephthalate (hereinafter PET intrinsic viscosity 0.60), polyphenylene sulfide (hereinafter referred to as PET intrinsic viscosity 0.60)
PPS manufactured by Phillips Petroleum Corporation, Ryton P
-4) and other various ingredients are dry blended in a tumble blender in the proportions shown in Table 1,
The composition was melted and kneaded using a 30 mmφ twin-screw extruder at a cylinder temperature of 280 to 295°C, and the extruded strands of the composition were pelletized using a strand cutter. Comparing the occurrence of strand breakage during strand collection,
Extrusion stability was evaluated. The obtained compound pellets were dried under reduced pressure at 130℃ for 4 hours, and the pellets obtained using an injection molding machine (model FS-75 manufactured by Nissei Jushi Kogyo Co., Ltd.) were heated at a cylinder temperature of 280-290-295℃ and a mold temperature of 280-290-295℃.
Discs of 100 mm in diameter and 3 mm in thickness and specimens 5 inches long, 1/2 inch wide, and 1/4 inch, 1/8 inch, and 1/16 inch thick were molded at 95°C. The surface characteristics were determined by mold release properties such as mold separation and sprue removal during disk molding, and surface gloss and flow pattern of the disk. Bending strength and heat distortion temperature were evaluated using ASTM D-790 and ASTM D-648 test methods, respectively. Solder resistance was determined by screwing 3mmφ4 types of tapping screws into a 1/16 inch thick test piece by the thickness, immersing only the screw portion in a solder bath set at 300℃ for various times, and then immediately pulling it up and measuring the immersion time so that the screw would not fall out. I found it and measured it. The results are shown in Table 1.

[Table] As is clear from Table 1, the composition of the present invention has good extrusion stability, and molded products with excellent mold releasability and surface properties can be obtained in low-temperature molds of 100°C or less. The molded parts exhibit good mechanical properties, high heat distortion temperatures and excellent solder resistance.
When a polyoxyalkylene compound is not added,
Comparative examples in which the amount is too low not only have unsatisfactory extrusion stability and moldability, but also have low heat distortion temperatures and large variations in solder resistance.
This confirms that PET and PPS lack uniform blendability. Example 2 A test piece was molded in the same manner as in Example 1 with the same composition as Example 1 No. 2 except for changing the type of polyoxyalkylene compound, and the moldability and characteristics of the molded product were evaluated, and the results are shown in Table 2. I got it.

【table】

[Table] As a result, the composition of the present invention containing a polyoxyalkylene compound compatible with PET provided excellent extrusion stability and moldability, and stable and improved solder resistance.

Claims (1)

[Claims] 1 A polyester containing ethylene terephthalate repeating units as a main component, mixed with 5 to 100% by weight of polyphenylene sulfide and 0.1 to 10% by weight of a polyoxyalkylene compound compatible with the polyester. A polyester composition characterized by: 2. The polyester composition according to claim 1, wherein the polyoxyalkylene compound has at least one group reactive with polyester. 3. The polyester composition according to claim 2, wherein the polyoxyalkylene compound is a compound having a polyoxyalkylene chain and an epoxy group.