JPH0358382B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic polyester resin composition comprising a thermoplastic polyester, polyphenylene sulfide (hereinafter abbreviated as PPS) and a novolak type epoxy resin. Thermoplastic polyesters for molding, such as polybutylene terephthalate (hereinafter abbreviated as PBT), have excellent heat resistance, chemical resistance, and electrical properties, and are used in various applications as engineering plastics. However, such polyesters are easily hydrolyzed and cannot be used for parts that come into contact with hot water or steam. In addition, thermoplastic polyester has a low heat distortion temperature when used alone, and only reaches a high heat distortion temperature when reinforced with a reinforcing agent such as glass fiber, but its long-term heat resistance is not sufficient and even when a reinforcing agent is used, it cannot be molded. It has disadvantages such as warping of the product and a decrease in the molding fluidity of the composition, resulting in a rough appearance of the molded product. Therefore, a method of blending PPS is known as one of the methods for improving the above-mentioned drawbacks. However, most of these compositions have insufficient compatibility, resulting in problems such as no improvement in hydrolysis resistance, a significant decrease in mechanical strength, and deterioration in the appearance of molded products. It was found that it was difficult to say that the original purpose of the blend was achieved. As a result of extensive studies, the present inventors have found that a composition consisting of thermoplastic polyester, PPS, and novolac type epoxy resin has excellent mechanical strength and compatibility, and has significantly improved hydrolysis resistance and heat resistance of thermoplastic polyester. We have discovered a highly practical thermoplastic polyester resin composition that has improved melt flow stability and bleed resistance at high temperatures, and has arrived at the present invention. That is, the present invention provides (A) thermoplastic polyester 99-
60 parts by weight, (B) 1 to 40 parts by weight of PPS, and (C) 0.1 to 20 parts by weight of novolac type epoxy resin (total of (A) and (B)
100 parts by weight). Here, thermoplastic polyesters include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, α,
β-bis(4-carboxyphenoxy)ethane,
Dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, and dimer acid, or their ester-forming derivatives, and ethylene glycol, propylene glycol, butanediol, pentanediol, neopentyl glycol, Hexanediol, octanediol, decanediol, cyclohexanedimethanol, hydroquinone, bisphenol A, 2,2-bis(4-hydroxyethoxyphenyl)propane,
It is a polyester obtained from glycols such as xylylene glycol, polyethylene ether glycol, polytetramethylene ether glycol, and aliphatic polyester oligomers with hydroxyl groups at both ends. in a mixed solvent with a weight ratio of
Intrinsic viscosity [η] measured at 30℃ is 0.3 to 1.5 dl/g
A range of materials is used. In addition, comonomer components include hydroxycarboxylic acids such as glycolic acid, hydroxybutyric acid, hydroxybenzoic acid, hydroxyphenylacetic acid, and naphthylglycolic acid, lactone compounds such as propiolactone, butyrolactone, valerolactone, and caprolactone, or thermoplastic properties. It may contain polyfunctional ester-forming components such as trimethylolpropane, trimethylolethane, glycerin, pentaerythritol, trimellitic acid, trimesic acid, and pyromellitic acid to the extent possible. Also, dibromoterephthalic acid, tetrabromoterephthalic acid, tetrabromophthalic acid, dichloroterephthalic acid, tetrachloroterephthalic acid, 1,4
- An aromatic nucleus such as dimethyloltetrabromobenzene, tetrabromobisphenol A, or an ethylene oxide adduct of tetrabromobisphenol A has a halogen compound such as chlorine or bromine as a substituent, and an ester-forming group. Also included is a thermoplastic polyester resin copolymerized with a halogen compound. Particularly preferred thermoplastic polyesters include:
PBT, polyhexamethylene terephthalate, poly(ethylene butylene terephthalate), poly(cyclohexane dimethylene terephthalate), poly(butylene tetramethylene ether terephthalate), 2,2-bis(β-hydroxyethoxytetrabromophenyl)propane Examples include polymerized polybutylene terephthalate. The PPS used in the present invention has the general formula

It is preferable that the composition contains 70 mol% or more of the structural unit represented by the formula; if the amount is less than 70 mol%, it is difficult to obtain the present composition with excellent properties. The polymerization method for this polymer includes a method of polymerizing p-dichlorobenzene in the presence of sulfur and soda carbonate;
Methods include polymerization in the presence of sodium sulfide or sodium bisulfide and sodium hydroxide or hydrogen sulfide and sodium hydroxide in a polar solvent, self-condensation of p-chlorothiophenol, etc. N-methylpyrrolidone, dimethylacetamide, etc. A suitable method is to react sodium sulfide with p-dichlorobenzene in an amide solvent such as sulfolane or a sulfone solvent such as sulfolane. At this time, in order to adjust the degree of polymerization, it is a preferable method to add an alkali metal salt of carboxylic acid or sulfonic acid, or to add alkali hydroxide. If it is less than 30 mol% as a copolymer component, a meta bond (

[Formula]), ortho bond (

[Formula]), ether bond (

[Formula]), sulfone bond (

[Formula]), biphenyl Join (

[Formula]), substituted Fe Nilsulfide bond (

[Formula] Here, R represents an alkyl group, a nitro group, a phenyl group, an alkoxy group, a carboxylic acid group, or a metal base of a carboxylic acid), a trifunctional bond (

[Formula]) may be contained as long as it does not significantly affect the crystallinity of the polymer, but preferably the copolymerization component is 10 mol% or less. In particular, when trifunctional or more functional phenyl, biphenyl naphthyl sulfide bonds, etc. are selected for copolymerization, the amount is preferably 3 mol % or less, more preferably 1 mol % or less. Such PPS can be produced by common manufacturing methods, such as (1) reaction of a halogen-substituted aromatic compound with an alkali sulfide (see U.S. Pat. No. 2,513,188, Japanese Patent Publication No. 44-27671 and Japanese Patent Publication No. 45-3368); 2) Condensation reaction of thiophenols in the coexistence of an alkali catalyst or copper salt (US Patent No. 3274165, British Patent No.
1160660), (3) Condensation reaction of aromatic compounds with sulfur chloride in the presence of a Lewis acid catalyst (Special Publication No. 1160660)
-27255, Belgian Patent No. 29437), etc., and can be arbitrarily selected depending on the purpose. In order to make the compatibility of the resin compositions easier, which is the main objective of the present invention, it is preferable that the resins to be mixed have similar viscosities and have a small amount of crosslinked structure. PPS is currently available on the market as Ryton PPS from Phillips Petroleum. Ryton PPS has V-1, P-2, P-3, P-4, R- depending on its crosslinking density and viscosity.
There are 6 grades. With conventional technology, Ryton V-1 has a low degree of crosslinking, but its viscosity is too low, and Ryton R-6 and P-4 have a high viscosity, but their degree of crosslinking is too high, and they do not have good compatibility with thermoplastic polyester. I couldn't get it. In the present invention, the epoxy resin is effective in increasing the molecular weight of PPS and is thought to react with polyester, so PPS with a low degree of coloring is preferable because it omits the oxidative crosslinking process, which could not be used conventionally due to its low viscosity. Can be used for The degree of crosslinking of PPS can be expressed by the relationship between the melt viscosity of the polymer and the non-Newtonian coefficient (N), and generally the larger N is, the higher the degree of crosslinking is. In other words, the PPS used in the present invention plots the respective logarithms of the shear rate and shear stress obtained during viscosity measurement, and
When the slope of the tangent at a point of 300° C. and a shear rate of 200 (1/sec) is defined as a non-Newtonian coefficient N, it is particularly preferable that N is between 0.8 and 1.33+0.000047×(melt viscosity). Furthermore, in the present invention, high molecular weight PPS with a low degree of crosslinking, which is known from JP-A-50-84698 and JP-A-51-144495, can also be suitably used. Novolac type epoxy resin, which is an essential component for improving the compatibility between PPS and thermoplastic polyester, contains two or more epoxy groups and is obtained by reacting novolak type phenolic resin with epichlorohydrin. There are no particular restrictions on the phenols that are the raw materials for the novolac type phenolic resin, but examples include phenol, o-cresol, m-cresol, p-cresol, bisphenol A, resorcinol, p-tert-butylphenol, bisphenol F, and bisphenol. Phenol S and mixtures thereof are particularly preferably used. Furthermore, an epoxidized product of poly-p-vinylphenol can also be used in the same manner as the novolak type epoxy resin. In the present invention, epoxy resins other than novolak type epoxy resins can also be used in combination within the range that does not deviate from the effects of the present invention. Typical other epoxy resins include glycidyl ethers such as diglycidyl ether of bisphenol A, diglycidyl ether of halogenated bisphenol butanediol instead of bisphenol A, and glycidyl esters such as phthalate glycidyl ester. ,
Non-glycidyl epoxy resins such as glycidylamine-based glycidyl epoxy resins such as N-siglycidylaniline, linear-based glycidyl epoxy resins such as epoxidized polyolefins, and epoxidized soybean oil, and cyclic-based non-glycidyl epoxy resins such as vinyl cyclohexene dioxide and dicyclopentadiene dioxide. is exemplified. The novolak type epoxy resin may be added at the same time as the other raw materials (PPS and thermoplastic polyester) constituting the composition of the present invention, but the epoxy resin and PPS or thermoplastic polyester may be added in advance. Considering the possibility of reaction between the novolak type epoxy resin and PPS and/or thermoplastic polyester, it is preferable to knead and then further mix and knead thermoplastic polyester or PPS. Alternatively, the novolac type epoxy resin may be added after previously kneading PPS and thermoplastic polyester. The mixing ratio of thermoplastic polyester and PPS is 99 to 60 parts by weight of thermoplastic polyester to 1 part by weight of PPS.
~40 parts by weight, preferably 5 to 40 parts by weight of PPS to 95 to 60 parts by weight of thermoplastic polyester. In addition, the amount of epoxy resin added is 0.1 to 20 parts by weight per 100 parts by weight of PPS and thermoplastic polyester.
parts by weight, preferably 1 to 10 parts by weight. If the amount is less than 0.1 part by weight, the effect will be small;
If the amount exceeds 1 part by weight, mechanical strength and thermal properties may be lost, and depending on the novolak type epoxy resin added, bleeding may occur on the surface of the molded product or the melt flowability of the composition may be significantly reduced, which is not preferable. In addition to the above-mentioned components, the following reinforcing fillers can be added to the composition of the present invention. Such reinforcing fillers include fibrous reinforcing agents such as glass fiber, carbon fiber, potassium titanate, asbestos, silicon carbide, ceramic fiber, metal fiber, and silicon nitride; barium sulfate, calcium sulfate, kaolin, clay, and pyrofluorite. , pentonite, sericite, zeolite, mica, mica, nephelinsinite, talc, attalpargite, wollastonite, processed mineral fiber (PMF), ferrite, calcium silicate, calcium carbonate, magnesium carbonate, dolomite , ammonium trioxide, zinc oxide, titanium oxide,
Magnesium oxide, iron oxide, molybdenum disulfide,
graphite, gypsum, glass beads, glass balloons,
Examples include inorganic reinforcing fillers such as quartz and quartz glass, and organic reinforcing fillers such as aramid fibers.
The amount of these fillers added is usually 1 to 300 parts by weight, preferably 5 to 200 parts by weight, per 100 parts by weight of the resin component (the total of PPS, thermoplastic polyester, and novolak type epoxy resin). If the amount added exceeds 300 parts by weight, there are problems such as poor melt flowability of the composition and impaired appearance of the molded product. The composition of the present invention may be mixed with the following thermoplastic resins without departing from the purpose of the present invention. The thermoplastic resins include vinyl monomers such as ethylene, propylene, butylene, pentene, butadiene, isoprene, chloroprene, styrene, α-methylstyrene, vinyl acetate, vinyl chloride, acrylic esters, methacrylic esters, and (meth)acrylonitrile. homopolymers or copolymers of polymers, polyurethane polymers, polyamide polymers, polyester elastomers, polycarbonates, polyacetals, polysulfones, polyarylsulfones, polyethersulfones, polyarylates, polyphenylene oxides, polyesters, Examples include homopolymers, copolymers, block and graft polymers of ether ether ketone, polyimide, polyamideimide, silicone resin, phenoxy resin, fluororesin, polyaryl ether and the like. In addition, a small amount of a mold release agent, a coupling agent, a coloring agent, a lubricant, a heat-resistant stabilizer, a weather-resistant stabilizer, a foaming agent, a flame retardant, a flame retardant aid such as antimony trioxide, etc. may be added. In the present invention, the composition of the invention can be prepared by various known methods. For example, there is a method in which the raw materials are uniformly mixed in advance in a mixer such as a tumbler or a Henschel mixer, and then fed into a single-screw or twin-screw extruder for melt-kneading and then prepared as pellets. EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples. Examples 1 to 5, Comparative Examples 1 to 4 With the formulation shown in Table 1, PPS and epoxy resin were mixed in advance using a 30 m/m twin screw extruder.
Each pellet was obtained by kneading at 280°C. Next, the pellets, PBT, and glass fibers were mixed according to the composition shown in Table 1, and kneaded at 280 DEG C. using a 40 m/m single screw extruder to obtain each pellet. The pellets were molded using a 3-ounce injection molding machine (cylinder temperature: 270°C, mold temperature: 80°C), test pieces were prepared, and the bending strength and heat distortion temperature were measured. Furthermore, hydrolysis resistance, molded product appearance, and melt flow stability were evaluated based on the following test methods. The results are summarized in Table-1. (Appearance condition of molded product) Γ Compatibility evaluation; Visual judgment ○...Excellent compatibility, good appearance ×...Poor compatibility, pearly luster, poor appearance Γ Smoothness evaluation; Visual judgment ○...Excellent gloss , Good appearance ×...Glass fibers are heavily lifted, surface condition is poor Γ Bleedability evaluation: The molded product was placed in the dryer at 150℃/
Visually judge the appearance of the molded product after leaving it for 2 hours. ○... No change in appearance due to bleed ×... Bleeding causes clouding on the surface of the molded product, significantly impairing its appearance (hydrolysis resistance: pressurized steam (PCT) test) Test piece for measuring bending strength was heated to 123°C. After being left in pressurized steam for 30 hours, the retention of bending strength is measured. (Melt flow stability) In order to evaluate the melt flow stability of pellets, a melt indexer was used to evaluate the melt flow stability of pellets at 265°C/6 minutes and 265 °C
The MI value (g/10 minutes) after holding at ℃/15 minutes was measured.

[Table] As is clear from the results shown in Table 1, the composition obtained by the present invention has high mechanical strength, excellent compatibility, and excellent PBT hydrolysis resistance and heat resistance. It was confirmed that the composition has improved melt flow stability and bleed resistance at high temperatures, and provides a smooth molded product appearance even under normal molding conditions, making it even more practical as a molding material.

Claims (1)

[Claims] 1 (A) 99 to 60 parts by weight of thermoplastic polyester, (B) 1 to 40 parts by weight of polyphenylene sulfide, and (C) 0.1 to 20 parts by weight of novolac type epoxy resin ((A) and
(B) based on a total of 100 parts by weight).