JPH0551025B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a highly heat-resistant thermoplastic resin composition with excellent oil resistance. More specifically, we will discuss the heat resistance, mechanical properties, and
This invention relates to a thermoplastic resin composition that has improved oil resistance (solvent resistance) while taking advantage of its excellent electrical properties and dimensional stability. [Prior Art] In recent years, with the development of the electronics industry, the number of cases in which plastic molded parts such as connectors are attached to printed wiring boards has increased dramatically, and the need for plastics suitable for this type of use has also increased. It's increasing. Plastic parts that are generally used on printed circuit boards require a high degree of dimensional accuracy, electrical properties, and rigidity, as well as heat resistance that can withstand soldering, and resistance to cleaning with Freon, halogen, and other solvents that are required after soldering. Must have solvent resistance. Especially recently, the miniaturization of parts,
In many cases, higher solder heat resistance is required due to demands for higher packaging density and faster processing speed. For example, in conventional soldering, soldering was done on the back side of the printed circuit board where the pins were inserted, and therefore the plastic molded product itself was not directly heated to the soldering temperature, but recently cream solder is used on the board. A so-called reflow soldering method has been proposed, in which the parts are attached in advance, and then the whole part is placed in a high-temperature furnace and the solder is melted and attached. In this case, the plastic molded product itself is also
It will be exposed to temperatures exceeding 260°C for tens of seconds or more, requiring an extremely high degree of heat resistance. Furthermore, in the solvent cleaning process after soldering, cleaning in a high-temperature steam state is becoming mainstream in order to increase cleaning efficiency, and demands regarding solvent resistance are becoming even higher. For these reasons, plastics such as polycarbonate and polybutylene terephthalate, which have traditionally been commonly used for this type of application, cannot meet the requirements, and plastics such as polyphenylene sulfide, polyether sulfone, and polyether ether ketone are being used. Plastic materials are attracting attention as meeting these demands. However, all of these materials are extremely expensive and are said to be difficult to use for general purposes, so there is a need for cheaper and better quality plastic materials. Incidentally, aromatic polyether resins are known as resins with excellent heat resistance. This aromatic polyether resin has excellent mechanical properties, electrical properties, and heat resistance, as well as good dimensional stability, so it is attracting attention as a resin suitable for a wide range of applications. However, its disadvantage is that it has poor solvent resistance, and it also does not have enough heat resistance to be soldered. It is also well known that there are problems with moldability. Various studies have been made to improve these drawbacks of polyether resins. For example, Tokko Akira
No. 45-995 proposes blending polyamide into an aromatic polyether resin in order to improve its moldability. Moreover, aromatic polyether resins and polyamides have very poor compatibility, and molded products obtained by injection molding exhibit a delamination phenomenon and have extremely poor mechanical properties. Tokukai Akira
In addition to the above components, No. 57-36150 contains a copolymer consisting of a styrene compound and an α,β-unsaturated carboxylic acid anhydride, which improves compatibility and provides excellent mechanical properties. It has been shown that it can be used as a molding material with chemical resistance. However, among the polyamides used in JP-A No. 57-36150, nylon has the highest heat resistance.
Even if 66 is selected, it does not have the solder heat resistance to withstand reflow soldering, and cannot be used for the above purpose. Furthermore, JP-A-59-27942 shows that dimensional accuracy, hygroscopicity, etc. can be further improved by using a copolymer obtained from xylylene diamine and aliphatic dicarboxylic acid as the polyamide component. . However, even in this case, it does not have a high degree of heat resistance that can withstand soldering heat resistance. Next, the constituent elements of the present invention will be explained in detail. [Problems to be Solved by the Invention] In view of this situation, the present invention has been made to provide a plastic material having dimensional stability, electrical properties, heat resistance, solvent resistance, etc. that meets the requirements for the above uses. It is something that [Means and effects for solving the problems] According to the present invention, polyphenylene ether 5-
50 parts by weight, non-grafted copolymer containing a styrene compound and an α,β-unsaturated carboxylic acid anhydride or an α,β-unsaturated carboxylic acid as components 3 to 25
Provided is a thermoplastic resin composition having good oil resistance and heat resistance and comprising 35 to 80 parts by weight of a polyamide resin having a crystal melting point in the range of 265 to 320°C. The polyphenylene ether of the present invention has the general formula [] [] (Here, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ are the same or different alkyl groups having 1 to 4 carbon atoms excluding tert-butyl groups, aryl groups, halogens, monovalent groups such as hydrogen, etc.) (R ₅ and R ₆ are not hydrogen at the same time.) is a repeating unit, and the constituent units are [] or [] and []. It refers to a graft copolymer made by graft polymerizing styrene, etc. Typical examples of homopolymers of polyphenylene ether include poly(2,6-dimethyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, and poly(2,6-dimethyl-1,4-phenylene) ether. 2,6-diethyl-1,4-phenylene)ether, poly(2-ethyl-6-npropyl-1,
4-phenylene)ether, poly(2,6-di-
n-propyl-1,4-phenylene) ether, poly(2-methyl-6-n-butyl-1,4-phenylene) ether, poly(2-ethyl-6-isopropyl-1,4-phenylene) ether, poly( 2-methyl-6-chloro-1,4-phenylene)
Ether, poly(2-methyl-6-hydroxyethyl-1,4-phenylene)ether, poly(2-methyl-6-hydroxyethyl-1,4-phenylene)ether,
Examples include homopolymers such as -methyl-6-chloroethyl-1,4-phenylene) ether. Polyphenylene ether copolymer is orthocresol or general formula (Here, R ₃ , R ₄ , R ₅ , and R ₆ are monovalent residues such as an alkyl group having 1 to 4 carbon atoms, an aryl group, a halogen, and hydrogen, excluding a tert-butyl group, and R ₅ , R ₆ is not hydrogen at the same time) 2, 3, 6
- It includes a polyphenylene ether copolymer mainly composed of a polyphenylene ether structure obtained by copolymerizing with an alkyl-substituted phenol such as trimethylphenol. Furthermore, styrene alone or a monomer copolymerizable with styrene may be graft-copolymerized to the above-mentioned polyphenylene ether. The non-grafted copolymer containing a styrene compound and α,β-unsaturated carboxylic acid anhydride or α,β-unsaturated carboxylic acid as components used in the present invention includes a non-rubber reinforced copolymer and Contains impact resistant rubber reinforced copolymers. Generally, the copolymer used in the present invention can be produced by conventional bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization techniques that utilize radical polymerization. Styrene compounds forming the copolymer used in the present invention include styrene, orthomethylstyrene, paramethylstyrene, dimethylstyrene, metaethylstyrene, chlorstyrene, isopropylstyrene, tert-butylstyrene, alphamethylstyrene, and ethylvinyl styrene. Toluene, etc., or mixtures thereof are used. α、β
- The unsaturated carboxylic anhydride may be a monomer that can be copolymerized with a styrene compound, such as maleic anhydride, chloromaleic anhydride, citraconic anhydride, butenylsuccinic anhydride, tetrahydrophthalic anhydride, etc. be. Examples of α,β-unsaturated carboxylic acids include acrylic acid, methacrylic acid, and ethacrylic acid. Furthermore, copolymerizable acrylic esters, methacrylic esters, vinyl cyan compounds, and the like may be used as the third component. The rubber-reinforced copolymers used in the present invention include polybutadiene rubber, styrene-butadiene rubber,
Polymerization of the monomers described above in the presence of a rubbery polymer such as polybutene rubber, hydrogenated styrene-butadiene rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber, polyacrylate rubber, polyisoprene rubber, natural rubber, etc. It can be obtained by letting Examples of suitable copolymers for use in the present invention include:
Styrene-maleic anhydride copolymer, styrene-
Maleic anhydride-methacrylic ester copolymer, styrene-maleic anhydride-acrylic ester copolymer, styrene-acrylic acid copolymer,
These include styrene-methacrylic acid copolymers and rubber-reinforced copolymers thereof. Further, the copolymer used in the present invention contains 60 to 99% by weight of a styrene compound as a component, and the content of α,β-unsaturated dicarboxylic acid anhydride or α,β-unsaturated carboxylic acid is 1 to 40% by weight. % of styrene, or a copolymer containing a styrenic compound and an α,β-unsaturated carboxylic acid anhydride or an α,β-unsaturated carboxylic acid as components in a range of 60 to 96% by weight of styrene. It is a copolymer of a type compound and 2 to 30% by weight of α,β-unsaturated dicarboxylic acid anhydride or α,β-unsaturated carboxylic acid and 2 to 20% by weight of methacrylic ester or acrylic ester. It is preferable. In the case of a rubber-reinforced copolymer, the composition of the resin phase excluding the rubber component is preferably within the above range. Even if the content of the styrene compound is too low, or the content of α,β-unsaturated carboxylic acid anhydride or α,β-unsaturated carboxylic acid is too low or too high, the resin composition Mechanical properties such as impact resistance strength deteriorate, which is undesirable. The polyamide used in the present invention has a crystal melting point of 265℃
The temperature needs to be in the range of ~320°C, preferably polyamide in the range of 270°C to 300°C. If the melting point is 265°C or higher, heat resistance, especially soldering heat resistance, will be insufficient, and if it exceeds 320°C, extrusion processability during composition production will be poor, and the decomposition and deterioration of components will be severe, resulting in poor quality, especially mechanical properties. decreases, which is not desirable. Examples of preferred polyamides include nylon 46 (polyamide from tetramethylene diamine and adipic acid; melting point 293 °C), nylon 44 (polyamide from tetramethylene diamine and succinic acid; melting point 287 °C), nylon 26 (polyamide from ethylene diamine and adipic acid; melting point 287 °C). polyamide; melting point 297°C), p
-Polyamides from phenylene diamine and sebacic acid (melting point 319°C), polyamides from p-cyclohexyldiamine and sebacic acid (melting point 296°C), polyamides from decamethylene diamine and p-phthalic acid (melting point 298°C), etc. Can be mentioned. The molecular weight of polyamide is 5000~50000, preferably 10000~
The range is 40000. A particularly preferred polyamide is nylon 46, which has a melting point of 290 to 295°C and a relatively wide thermoformable temperature range. The above-mentioned polyphenylene ether, a non-grafted copolymer containing a styrene compound and an α,β-unsaturated carboxylic acid anhydride or an α,β-unsaturated carboxylic acid as a component, with a crystal melting point of 265 to 320°C It is necessary to combine polyamides within the following ranges in the following proportions. That is, 5 to 50 parts by weight of polyphenylene ether, 3 to 25 parts by weight of styrene copolymer, 35 to 80 parts by weight of polyamide, and more preferably 10 parts by weight of polyphenylene ether.
35 parts by weight, 5 to 15 parts by weight of the styrene copolymer, and 40 to 70 parts by weight of the polyamide. The reason for limiting the proportion to this range is that if the aromatic polyether resin is less than 5 parts by weight, the dimensional stability, especially the warp of the molded product, will deteriorate, and if it exceeds 50 parts by weight, the solvent resistance and molding fluidity will decrease. The styrene copolymer is necessary to improve the compatibility of the system, and if it is less than 3 parts by weight, the layers tend to peel off, and if it is more than 25 parts by weight, the heat resistance will be impaired. If the amount of polyamide is less than 35 parts by weight, the heat resistance and solvent resistance will be impaired, and if it is more than 80 parts by weight, the electrical properties and dimensional changes due to warpage and moisture absorption of the molded product will become large, which is not preferable. It is particularly preferable for the polyamide component to exist as a continuous layer component in the system from the viewpoint of maintaining heat resistance. Further, in a general embodiment of the present invention, in addition to the above-mentioned resin composition, fibrous reinforcing agents such as glass fiber, carbon fiber, metal fiber, asbestos, clay, silica, talc, calcium carbonate, wolast, etc. It is suitable to add an inorganic filler such as night and use it as a composite material. In particular, composites with glass fibers are suitable for improving heat resistance and mechanical strength, but depending on the purpose, addition of reinforcing agents and fillers is not always essential. the above reinforcing agent,
Fillers can be used alone or in combination,
The blending amount thereof is 5 to 150 parts by weight, preferably 10 to 70 parts by weight, per 100 parts by weight of the above resin composition. Further, other compounding agents can be appropriately added to the resin composition of the present invention. Examples of these are impact strength reinforcing agents, flame retardants, plasticizers, lubricants, colorants, stabilizers, etc. Examples of impact strength reinforcing agents include thermoplastic elastomers, rubber-modified polystyrene resins (HIPS), and BAS resins.
Thermoplastic elastomers are particularly preferred. Examples include styrene-butadiene block copolymers, hydrogenated styrene-butadiene block copolymers, ethylene-propylene elastomers, styrene-grafted ethylene-propylene elastomers, thermoplastic polyester elastomers, etc., in the range of 1 to 20 parts by weight. It can be added as appropriate. As the flame retardant, aromatic halogen compounds, halogenated polystyrene, halogenated polycarbonate, mixtures of these with antimony oxide, elemental red phosphorus, or phosphorus compounds can be used, and two or more of these compounds can be used in combination. Good too. Further, other thermoplastic resins may be added as appropriate within a range that does not impair the purpose of the present invention. Examples thereof include polystyrene, polyethylene, polypropylene, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, etc., and the amount added is about 1 to 20 parts by weight per 100 parts by weight of the composition of the present invention. As a method for obtaining the resin composition of the present invention, a method of melt-mixing using an extruder, roll mixer, Banbury mixer, kneader mixer, etc. can be used. Regarding the order of melt-mixing, all the components may be melt-mixed at the same time, or a method may be used in which two to three types of components are melt-mixed in advance. The most standard mixing method is to use a twin-screw extruder and melt-knead at a temperature of 280°C to 340°C. In addition, during melt mixing, plasticization efficiency is increased,
0.01 to 2 of the composition weight in order to improve molding fluidity.
It is effective to add % by weight of low molecular weight carboxylic acids. As the low molecular weight carboxylic acid, oxalic acid, fumaric acid, maleic acid, benzoic acid, maleic anhydride, adipic acid, etc. can be used. [Example] The present invention will be explained in detail with reference to Examples below.
Nylon 46 used in the examples was synthesized by the following method. Nylon 46 (polytetramethylene adipamide)
Synthesis of based on the amount of adipic acid in an autoclave
Dried 1, containing an excess amount of diamine of 6.5 mol%
A prepolymer was prepared by heating 5 kg of 4-diaminobutane/adipic acid salt at a reaction temperature of 220°C and a reaction time of 3 hours. The obtained prepolymer was cooled after releasing the pressure and then ground to an average particle size of 0.1-0.2 mm. Dissolve 1 g of this prepolymer in 100 g of 98% sulfuric acid,
The relative viscosity (ηr) measured at °C was 1.40, which corresponded to a number average molecular weight of 3400. Next, 4 kg of this prepolymer was transferred to a stainless steel reaction vessel and heated at 260° C. for 5 hours under normal pressure N ₂ gas blowing for post-condensation. As a result, white, granular nylon 46 with an ηr of 4.3 and a number average molecular weight of 32,000 was obtained. The melting point measured by DSC method was 293°C. Examples 1 to 4, Comparative Examples 1 to 5 Poly(2,6-dimethylphenylene-1,4-) having an intrinsic viscosity of 0.62 (25°C, in chloroform)
ether), nylon 46, nylon 66, styrene-maleic anhydride copolymer (maleic anhydride content 10% by weight), styrene-methacrylic acid copolymer (methacrylic acid content 8% by weight), 3 mm long glass fiber The chopped strands were fed into a 30φ twin-screw extruder according to the formulation shown in Table 1, and extruded and kneaded at a temperature of 320° C. and a discharge rate of 5 kg/hr to form pellets. Next, a test piece was prepared using an injection molding machine, and its characteristics were evaluated according to the following test method. Heating deformation temperature: JIS K7207 Tensile strength: JIS K7113 Flexural modulus: ASTM-D790 Izot impact strength: JIS K7110 1/4″ thickness, with notch Warpage rate of molded product: 150 x 150 x 3 mm flat plate diagonal measurement Molding shrinkage rate ;ASTM-D1299 150×150×3mm
Flat plate Moisture absorption test: 60℃, 95%RH, weight change rate in 24 hours From the results shown in Table 1, Examples 1 to 4 are Comparative Example 5
In addition to having better heat resistance than the nylon 66 base, the other properties are also nearly the same balance as Comparative Example 5. On the other hand, Comparative Example 1, which does not have a preferable composition, has poor compatibility and poor impact strength, warping, and hygroscopicity, while Comparative Example 2 has poor warping, hygroscopicity, and
Comparative Example 3 is inferior in heat resistance and solvent resistance, and Comparative Example 4 is inferior in solvent resistance.

[Table] Example 5 Test pieces (100 x 12 x 15 mm) of Examples 1 to 4 and Comparative Example 5 and glass-reinforced polybutylene phthalate resin (Barox 420-
SEO), glass-reinforced polyethylene phthalate resin (Rynite ER530), and polyphenylene sulfide resin (Ryton R-4) test pieces were each immersed in a solder bath at the temperature shown in Table 2 for 10 seconds.
The degree of deformation was determined and the results are shown in Table 2.

[Table] As is clear from Table 2, the test pieces of Examples 1 to 4 have solder heat resistance comparable to that of polyphenylene sulfide resin. Example 6, Comparative Example 6 Poly(2,6-dimethylphenylene-1,4-
ether), nylon 46, nylon 66 (Leona
1300S), styrene-maleic anhydride copolymer (maleic anhydride content 10% by weight), styrene-butadiene hydrogenated block copolymer (Kraton
G1650 Ciel), Pyro 4 as a flame retardant
7.68PB (Nissan Ferro Co., Ltd.) and antimony trioxide were supplied to a 30φ twin-screw extruder according to the formulation shown in Table 3.
Extrusion kneading was carried out at a temperature of 310°C and a discharge rate of 3 kg/hr.
Next, a test piece was prepared using an extrusion molding machine, and the ball pressure temperature (IEC Publication 335-1) was adjusted to
Solvent resistance and flame retardancy (UL-94) were measured, and the results shown in Table 3 were obtained. It can be seen that the examples have better heat resistance than the comparative examples.

[Table] [Effects of the invention] As described above, the thermoplastic resin composition of the present invention has the following properties:
A non-grafted copolymer containing polyphenylene ether, a styrene compound and an α,β-unsaturated carboxylic acid anhydride or an α,β-unsaturated carboxylic acid as a component, with a crystal melting point in the range of 265 to 320°C By adding a specific amount of each of the polyamide resins, it has improved oil resistance while taking advantage of the excellent heat resistance, mechanical properties, electrical properties, and dimensional stability of polyphenylene ether. Its superiority can be demonstrated especially when used in applications that require a high degree of heat resistance, such as reflow soldering, or applications that require solvent resistance to solvents in high-temperature steam conditions. be.

Claims (1)

[Scope of Claims] 1. A non-grafted copolymer containing 5 to 50 parts by weight of polyphenylene ether, a styrene compound and an α,β-unsaturated carboxylic acid anhydride or an α,β-unsaturated carboxylic acid as components. 3 to 25 parts by weight of a polyamide resin with a crystal melting point in the range of 265 to 320°C
A thermoplastic resin composition with good oil resistance and heat resistance consisting of 80 parts by weight. 2 For 100 parts by weight of the above thermoplastic resin composition,
The resin composition according to claim 1, which contains 5 to 150 parts by weight of a reinforcing agent in the form of fibers, flakes, or powder.