JPS636109B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester composition that has excellent mechanical properties and a high heat deformation temperature, and can provide lightweight molded products without warping. Polyalkylene terephthalate, a type of engineering resin, is used in a variety of applications due to its excellent mechanical properties and other properties, and its demand will continue to grow in the future in fields such as automobile parts and electrical parts. It is predicted that In order to further improve the mechanical properties of this polyalkylene terephthalate, it has been known to incorporate an inorganic filler such as glass fiber. However, molded articles made of polyester compositions containing directional fillers such as glass fibers have a problem in that they may warp significantly depending on their shape. Plate-shaped mica, talc, and needle-shaped wollastenite are known as fillers that do not cause warping, but these fillers have considerable three-dimensional orientation. Improvements in warpage are still not sufficient, and in order to suppress warpage, it is necessary to add a large amount of filler, which has the disadvantage that the molded product becomes quite heavy. On the other hand, Shirasu Balloon (Japanese Unexamined Patent Application Publications No. 121851/1985 and No. 136057/1983) is known as a filler for polyalkylene terephthalate that can reduce the weight of molded products. Although it has the advantage of not having three-dimensional orientation, due to the low strength of the filler itself, a considerable amount breaks down during melt mixing with polyalkylene terephthalate, making it impossible to obtain the desired mechanical properties. However, there is a problem in that the sled improvement and weight reduction effects cannot be fully demonstrated. Therefore, the present inventors conducted intensive studies with the aim of obtaining polyalkylene terephthalate that has excellent mechanical properties and can be used to form lightweight molded products without warping. The present invention was achieved by discovering that particularly excellent effects can be obtained by blending inorganic hollow spheres and glass fibers together. That is, the present invention provides a polyester composition comprising 3 to 200 parts by weight of fly ash micro hollow spheres to 100 parts by weight of polyalkylene terephthalate, and 3 to 200 parts by weight of fly ash micro hollow spheres to 100 parts by weight of polyalkylene terephthalate and glass fibers. The object of the present invention is to provide a polyester composition containing 1 to 50 parts by weight. The polyalkylene terephthalate used in the present invention is a polymer or copolymer obtained by a condensation reaction containing terephthalic acid (or its ester-forming derivative) and diol (or its ester-forming derivative) as main components. . Note that 40 mol% or less of the acid component is dicarboxylic acids other than terephthalic acid, such as isophthalic acid, phthalic acid, methyl terephthalic acid, methyl isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1.5 - Aromatic dicarboxylic acids such as naphthalene dicarboxylic acid, bis(p-carboxyphenyl)methane, anthracene dicarboxylic acid, and 4,4'-diphenyl ether dicarboxylic acid; fats such as adipic acid, sebacic acid, azelaic acid, and succinic acid; It may be substituted with alicyclic dicarboxylic acids such as group dicarboxylic acids, 1,3-cyclohexanedicarboxylic acids, and 1,4-cyclohexanedicarboxylic acids. The diol component forming polyalkylene terephthalate has the general formula HO(CH ₂ ) _o OH (n=2-12)
It can be one kind or a mixture of two or more kinds. Typical diols represented by the above general formula include ethylene glycol, propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. In addition, some of the diol components are neopentyl glycol,
Other aliphatic diols such as 1,3-butanediol, alicyclic diols such as 1,4-cyclohexanedimethanol, dihydroxybenzenes such as hydroquinone and resorcinol, 2,2-bis(4
Other types of diols may be substituted, such as bisphenols such as -hydroxyphenyl)-propane and 2,2-bis(4-hydroxyphenyl)-sulfone. In addition, polyalkylene terephthalate has ε-
A small amount of oxycarboxylic acid such as oxycaproic acid, hydroxybenzoic acid, and hydroxyethoxybenzoic acid may be copolymerized. Furthermore, if it is 1.0 mol% or less in the above polyalkylene terephthalate, tricalivallylic acid,
Even if branched components with ester-forming ability such as trifunctional or tetrafunctional polycarboxylic acids such as trimesic acid and trimellitic acid, trifunctional or tetrafunctional alcohols such as glycerin, trimethylolpropane, and pentaerythritol are copolymerized, good. Specific examples of polyalkylene terephthalate include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polydecamethylene terephthalate, and the like. Among these polyalkylene terephthalates, particularly preferred is polybutylene terephthalate, which has a fast crystallization rate. In addition, these polyalkylene terephthalates can be prepared by adding a 0.5% orthochlorophenol solution to 25°C.
It is preferable that the relative viscosity when measured is in the range of 1.3 to 1.8. If the relative viscosity of the polyalkylene terephthalate is less than 1.3, sufficient mechanical properties cannot be obtained, and if it is 1.8 or more, the destruction of the micro hollow spheres progresses, which is not preferable. The fly ash micro hollow spheres used in the present invention are inorganic hollow spheres isolated from fly ash residue produced during coal combustion, and contain SiO ₂ 55-61
%, _{Al2O3 26-30} %, alkaline component 0.5-4.0%,
It has a chemical composition of 10% or less Fe ₂ O ₃ .
Fly ash micro hollow bodies are usually available with a particle size of 1 to 500μ, but in general, as the particle size increases, it tends to break when mixed with polyalkylene terephthalate.
Those with a diameter of 300μ or less, particularly 150μ or less are preferably used. The blending amount of these fly ash micro hollow spheres is 3 to 200 parts by weight, preferably 5 to 100 parts by weight, per 100 parts by weight of polyalkylene terephthalate; if it is less than 3 parts by weight, the effect of improving mechanical properties will not be sufficient; If it exceeds 200 parts by weight, the mechanical properties will deteriorate, which is not preferable. A composition in which polyalkylene terephthalate is blended with fly-assembly microscopic hollow spheres can provide a molded product that has improved warpage and is lightweight, and its mechanical properties are also improved. When used in combination, a synergistic improvement in mechanical properties and heat distortion temperature can be obtained, which is more synergistic than the effect expected when glass fiber and fly ash microhollow relief bodies are blended alone. The glass fibers used in the present invention may generally be commercially available ones, and the fiber length is not particularly limited, but preferably 1 to 15 mm. Further, the glass fiber may be treated with a vinyl compound, an epoxy compound, or the like. The amount of glass fiber blended is based on 100 parts by weight of polyalkylene terephthalate.
1 to 50 parts by weight, preferably 3 to 30 parts by weight,
If it is less than 1 part by weight, the synergistic effect of improving the mechanical properties and heat distortion temperature of the polyalkylene terephthalate will be small, and if it is more than 50 parts by weight, the effect of improving warpage by adding the fly ash micro hollow bodies will be reduced, which is not preferable. The method of blending the composition of the present invention is not particularly limited, but preferably a method of adding and mixing fly ash micro hollow spheres or glass fibers to polyalkylene terephthalate in a molten state, and a method of adding and mixing polyalkylene terephthalate and fly ash micro hollow spheres. Examples include a method in which the sphere or the sphere and the glass fiber are mixed in advance and then further melted and mixed. The fly ash micro hollow spheres can also be used after being treated with a coupling agent such as silane or titanium. The composition of the present invention may further contain various other additives within a range that does not impair the purpose of the present invention. These other additives include reinforcing agents, fillers, nucleating agents such as asbestos fibers, rock wool, calcium carbonate, silica sand, bentonite, kaolin, talc, clay, wollastenite, barium sulfate, glass beads, mica, etc. Antioxidants, ultraviolet absorbers, heat stabilizers, lubricants, mold release agents, colorants including dyes and pigments, flame retardants (halogen-based, phosphorus-based, etc.), flame retardant aids (antimony typified by antimony trioxide) compounds, zirconium oxide, molybdenum oxide, etc.), blowing agents, crosslinking agents (for example, polyvalent epoxy compounds, isocyanate compounds, acid anhydrides, etc.). Other synthetic resins (e.g. polyester, polyamide, polycarbonate, polystyrene, polyethylene, polypropylene, acrylic resin, ethylene/vinyl acetate copolymer, ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/
One or more types of glycidyl methacrylate copolymer, ethylene/propylene copolymer, polybutadiene, phenolic resin, silicone resin, etc.) may be blended within the range that does not impair the object of the present invention. The composition of the present invention can be molded very easily in a conventional manner using a general thermoplastic resin molding machine. Further, the composition of the present invention can be widely used in various applications such as components of precision machines and interior and exterior parts of automobiles by taking advantage of its characteristics. The present invention will be specifically explained below with reference to Examples. Example 1 Polybutylene terephthalate with relative viscosity of 1.48
Add the filler shown in Table 1 to 100 parts by weight,
The mixture was melt-mixed and pelletized using a vented 40 mmφ screw extruder set at 250°C. The obtained pellets were molded using a screw-in-line 5-ounce injection molding machine at a molding temperature of 250°C, a mold temperature of 80°C,
The molding cycle was 15 seconds for injection and 20 seconds for cooling to obtain a square plate with a thickness of 1 mm, a length of 80 mm, and a width of 80 mm, and an ASTM bending test piece with a thickness of 1/4 inch. Table 1 also shows the characteristics evaluation results for these test pieces. In addition, the warping test is performed by placing the above square plate on a surface plate and fixing one vertex of the four corners on the surface plate, and measuring the vertical lift distance of the vertex from the surface plate in the diagonal direction. This was done by measuring the The smaller the lifting distance, the smaller the warpage of the molded product, and the smaller the warpage when molded products of various shapes are molded. In addition, using the above ASTM bending test piece,
A bending test was conducted in accordance with ASTM D790 to determine bending strength and bending modulus. The heat distortion temperature was measured using a bending test piece under a load of 18.56 kg/cm ² . Specific gravity was measured according to ASTM D792.

[Table] From the results in Table 1, it can be seen that when fly ash micro hollow spheres are added (Nos. 1 to 3), there is no warping compared to when other fillers are added (Nos. 7 to 11).
A polyester composition with excellent mechanical properties and lightweight can be obtained, and when fly ash micro hollow spheres and glass fiber are used together (No. 4 to 6)
It is clear that the mechanical properties and heat distortion temperature are synergistically improved, and a lightweight polyester composition without warpage can be obtained.

Claims (1)

[Claims] 1. A polyester composition comprising 100 parts by weight of polyalkylene terephthalate and 3 to 200 parts by weight of fly ash microscopic hollow spheres. 2. A polyester composition comprising 100 parts by weight of polyalkylene terephthalate mixed with 3 to 200 parts by weight of fly ash microscopic hollow spheres and 1 to 50 parts by weight of glass fiber.