JPH0233067B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a resin composition that is suitable for metallizing processing of molded products mainly composed of polytetramethylene terephthalate, which has improved surface smoothness and excellent heat resistance, and more specifically, a resin composition that is suitable for metallizing processing of molded products mainly composed of polytetramethylene terephthalate. A resin suitable for metallizing processing that has excellent heat resistance and rigidity and improved surface smoothness by blending a resin material made of a mixture of agglomerate and a specific resin with an inorganic filler having a specific particle size. Regarding the composition. Glass fiber reinforced products of polytetramethylene terephthalate have excellent moldability, mechanical properties, heat resistance, etc., and are well-balanced in performance.
It is widely used as an engineering plastic. The drawback of this glass fiber reinforced material, which is that it tends to warp when molded, has been improved by using glass fibers in combination with inorganic fillers, and by blending it with other polymers, and its uses are further expanding. Taking advantage of the excellent properties of polytetramethylene terephthalate, especially its heat resistance, studies are being conducted to apply metallization to reflectors of lighting equipment and the like. However, after a detailed evaluation and study of the suitability of reinforced polytetramethylene terephthalate resin for reflector materials, etc., it was found that although there were no problems with heat resistance or mechanical properties, materials reinforced with ordinary reinforcing agents,
The surface smoothness of the molded product was extremely poor, and when the molded product was subjected to, for example, aluminum vapor deposition, a clean mirror surface could not be obtained and light would be reflected diffusely. Therefore, conventional reinforced polytetramethylene terephthalate cannot be used in applications such as reflectors that require surface smoothness and heat resistance. In view of the current situation, the present inventor conducted intensive studies to improve the surface smoothness of reinforced polytetramethylene terephthalate, and found that using a mixture of polytetramethylene terephthalate and a specific resin compared to polytetramethylene terephthalate alone. It has been found that molded products are less likely to have sink marks and that a material with high smoothness can be obtained. Regarding reinforcing fillers, the smaller the particle size, the better the surface smoothness tends to be, but on the other hand, heat resistance, rigidity, etc. decrease. However, by making the reinforcing filler have a specific particle size distribution, it is possible to achieve far superior planar smoothness and well-balanced properties in terms of heat resistance and rigidity compared to simply blending a filler with a fine particle size. They discovered this and arrived at the present invention. That is, the gist of the present invention is to combine polymers mainly composed of polytetramethylene terephthalate with AAS resins, ABS resins, AS resins, acrylic resins, rubber-modified acrylic resins, polycarbonate resins, and polyester-polyether block copolymers. Resin material (A) consisting of a mixture with one or more resins selected from coalescence, 95 to 40% by weight, fiber length
Fibrous filler (B) 1 to 40% by weight of 300μ or less, inorganic filler (C) 3 to 40% with average particle diameter D ₅₀ of 2μ or more and 50μ or less
58% by weight, and 1 to 25% by weight of an inorganic filler (D) having an average particle diameter _D50 of less than 2μ, and has excellent surface smoothness. The resin material (A) constituting the composition of the present invention is a polymer synthesized by a known method from tetramethylene glycol and terephthalic acid or dimethyl terephthalate, and further contains other dicarboxylic acid components in an amount of 15 mol% or less. Polymer copolymerized with diol component and 40% by weight or less AAS resin,
Examples include mixtures with one or more resins selected from ABS resins, AS resins, polycarbonate resins, polyester-polyether block copolymers, acrylic resins, and rubber-modified acrylic resins. The proportion of the resin material (A) used is in the range of 95 to 40% by weight in the resin composition. Its usage rate is 95
If it exceeds 40% by weight, there is no reinforcing effect, and if it exceeds 40% by weight.
If it is less than that, heat resistance will decrease. Polytetramethylene terephthalate, which is the resin material (A), and 40% by weight or less of AAS resin, ABS resin,
A mixture of AS resin, polycarbonate resin, polyester-polyether block copolymer, and one or more resins selected from acrylic resins and rubber-modified acrylic resins causes more sink marks on molded products than polytetramethylene terephthalate alone. This is less likely to occur and a material with high smoothness can be obtained. However, other resin components in the resin material (A) are 40%
Exceeding this percentage by weight is not preferable because heat resistance decreases. In the present invention, the fibrous filler (B) with a fiber length of 300μ or less includes glass fibers commercially available called milled fibers, cut fibers, glass powders, etc., carbon fibers such as pitch type, asbestos, acicular metasilicic acid, etc. Examples include calcium (wollastonite fiber), gypsum whiskers, potassium titanate whiskers, metal fibers, processed mineral fibers, etc., and the fiber length is 300μ or less and the length/diameter ratio is 5 or more. As the fiber length becomes longer, the reinforcing effect becomes higher, but the appearance of the molded product deteriorates, which is not preferable. These fibers may be used alone or in combination, and fibers subjected to various surface treatments are also preferably used. Particularly preferably used are glass middles or cut fibers and potassium titanate whiskers. The amount of the fibrous filler (B) added is 1 to 40% by weight of the resin composition. Addition amount is 1% by weight
If it is less than 40% by weight, the reinforcing effect will be small, and if it exceeds 40% by weight, moldability and appearance will deteriorate, which is not preferable.
Particularly preferred is a range of 3 to 30% by weight. Furthermore, the average particle diameter D ₅₀ used is 2μ or more and 50μ
The following inorganic fillers (C) include amorphous glass powder, glass beads, glass flakes, talc, clay, kaolin, calcium metasilicate powder, dawsonite, silica powder, quartz powder, mica powder, metal powder, and boron nitride. 1 selected from powder etc.
A species or two or more species. The amount of the inorganic filler (C) added is 3 to 58% by weight. If it is less than 3% by weight, sufficient mechanical and thermal reinforcing effects will not be exhibited, and if it exceeds 58% by weight, it will be difficult to uniformly disperse it and the appearance will deteriorate, which is not preferable. Furthermore, the inorganic filler (D) with an average particle diameter D ₅₀ of less than 2 μm includes glass powder, talc,
clay, lithopone, kaolin, calcium carbonate,
Calcium metasilicate powder, silica powder, metal powder, titanium oxide, etc. are listed, and as long as the average particle diameter D ₅₀ is less than 2μ, they may be used alone or in combination _of two or more. It may be the same component as the filler (C) as long as it satisfies the requirements. Especially 1μ
The following particle diameters are preferred. The amount of the filler (D) added is 1 to 25% by weight.
It is. If the amount is less than 1% by weight, the effect of improving appearance is insufficient, and if the amount added exceeds 25% by weight, the effect of improving appearance is small and the reinforcing effect is also reduced, which is not preferable. The amount of filler (D) added is particularly preferably in the range of 3% by weight to 20% by weight. As the fillers (C) and (D), fillers that have been subjected to various surface treatments are also preferably used. Examples include fillers treated with silane coupling agents, fatty acid treatment, titanate coupling agents, etc. The resin composition of the present invention has excellent heat resistance, and the filler has a preferable particle size distribution, so the resulting molded product has an excellent appearance, especially surface smoothness, despite being a fiber-reinforced resin, and has metallization on the surface. Reflectors, exterior materials, and housing materials for automobiles, electrical products, etc. that require high heat resistance and mechanical properties, with a good metal appearance obtained through treatments such as plating, metal vapor deposition, and sputtering. suitable for Such resin compositions may contain stabilizers such as antioxidants, modifiers such as dyes and pigments, and epoxy resins, as necessary.
A mold release agent, a flame retardant, and the like can be added. In particular, if the flame retardant evaporates or sublimates at high temperatures, it will damage the appearance of the molded product, so non-bleed type flame retardants, such as brominated epoxy resin,
It is preferable to use polymeric flame retardants such as brominated polycarbonate oligomers and brominated polyester oligomers. To carry out the present invention, any method well known to those skilled in the art can be applied, for example, sufficiently dried pellets of polytetramethylene terephthalate, other polymers, fibrous fillers and fillers of various particle sizes can be used. Examples include a method of mixing in a blender and then melt-mixing through an extruder. This will be explained in more detail below with reference to Examples. Examples 1 to 8, Comparative Examples 1 to 3 Polytetramethylene terephthalate having an intrinsic viscosity [η] of 0.93, other resins, and fillers were weighed in the proportions shown in Table 1, and mixed for 5 minutes in a V-type blender. The resin composition was melt-extruded using a 65φ single vent extruder at an extrusion temperature of 250°C and shaped into pellets to obtain a resin composition. This was injection molded using a famous SJ35B injection molding machine at a cylinder temperature of 260°C and a mold temperature of 100°C to obtain molded products for various evaluations. Table 1 shows the results of various evaluations performed using these molded products. In the table, the appearance of the molded product was evaluated using a 60 x 100 x 3 mm ^t -molded plate, and those with particularly few sink marks are rated ◎, those with few sink marks are rated ○, and those with noticeable sink marks are rated △ to ×. did. In addition, surface smoothness was determined visually. The molded article obtained from the composition of the present invention has sink marks,
It had excellent appearance and surface smoothness without warping, and showed high heat resistance. On the other hand, when the fiber length is too long as in Comparative Examples 1 and 2, the surface is extremely rough and the smoothness is poor, and when there is no fibrous filler and only small particle diameter as in Comparative Example 3, the surface smoothness is poor. Although it was good, its heat resistance and mechanical properties were poor. Next, using the compositions obtained in Examples 3 to 4 and Comparative Examples 1 to 3, a tube was prepared with a diameter of 120 mm, a depth of 15 mm, and a thickness of 2 mm.
The cylinder temperature is 260℃ and the mold temperature is 100℃.
It was injection molded at ℃, and an acrylic ultraviolet curing paint was sprayed on the inside to a thickness of about 20μ and cured using a high-pressure mercury lamp. This molded product was vapor-deposited with aluminum and coated with acrylic-urethane clear paint at 150°C x 30°C.
I baked it for a minute and used it as a top coat. The vapor-deposited product obtained from the composition of the present invention exhibited a good mirror surface, and the molded product had little warpage. This is sufficient for the important application of reflector isoluminance and its focus. On the other hand, the compositions of Comparative Examples 1 and 2 that were vapor-deposited had sink marks, and the surface roughness was even more noticeable due to vapor deposition, resulting in a satin-like appearance and a completely inferior appearance. Furthermore, although the vapor-deposited product obtained from Comparative Example 3 had excellent surface smoothness, it had sink marks and, in particular, had low heat resistance, so warpage was observed in the center of the 120φ lower part after vapor deposition. In other words, a molded article with excellent appearance and heat resistance can be obtained even if metallizing is performed only when a filler with a specific fiber length and particle size is blended, as in the composition of the present invention. However, the object of the present invention cannot be achieved using only a fibrous filler or only a filler with a fine particle size.

【table】

[Table] Example 5 Polytetramethylene terephthalate with an intrinsic viscosity [η] of 0.86, ABS resin (acrylonitrile/
Polybutadiene/styrene weight ratio is 20/30/50
graft polymer), diameter approximately 10μ, fiber length approximately
250μ glass milled fiber, average particle size D ₅₀
Glass powder with a particle diameter of 30 μ, Ritobon with an average particle size _D50 of 0.5 μ, and brominated epoxy resin as a flame retardant and antimony trioxide with an average particle size of 1 μ are weighed in the proportions shown in Table 2, and mixed for 5 minutes in a V-type blender. did. This was carried out in exactly the same manner as in Example 1 using a 65φ single vent extruder to obtain a resin composition of the present invention. This was made using the famous SJ35B injection molding machine at a cylinder temperature of 260°C and a mold temperature of 100°C, with a diameter of 120 mm and a depth of 15 mm.
A circular lid with a thickness of 2 mm was molded. It had a good appearance with no sink marks or warpage. Aluminum vapor deposition was performed on the inside of this molded product in exactly the same manner as in Example 3,
The top coat that was baked at 150°C for 30 minutes showed a good mirror surface without molding warpage, and had excellent heat resistance. Furthermore, 10 burners with a flame length of about 2 cm were attached to this molded product.
There was a flame in seconds, and when the burner was removed, the fire extinguished in 3 seconds and was self-extinguishing. The molded article obtained from the composition of the present invention has high heat resistance and also exhibits excellent surface smoothness with a good appearance due to metallization processing.

【table】

Claims (1)

[Claims] 1 A polymer mainly composed of polytetramethylene terephthalate and one or more resins selected from AAS resin, ABS resin, AS resin, acrylic resin, rubber-modified acrylic resin, polycarbonate resin, and polyester-polyether block copolymer. A resin material consisting of a mixture of (A) 95 to 40% by weight, a fibrous filler with a fiber length of 300μ or less (B) 1 to 40% by weight,
Inorganic filler (C) with average particle diameter (D) 50 of 2μ or more and 50μ or less
A resin composition having excellent surface smoothness, comprising 3 to 58% by weight of an inorganic filler (D) and 1 to 25% by weight of an inorganic filler (D) having an average particle diameter (D) of less than 2μ.