JPS596250A - Resin composition having excellent surface smoothness - Google Patents

Abstract

PURPOSE:To provide a resin compsn. having excellent high-temperature rigidity, improved surface smoothness and adaptability for metallization, by blending inorg. fillers having a specified particle size with a polymer mainly composed of polytetramethylene terephthalate. CONSTITUTION:A resin compsn. having excellent surface smoothness consists of 95-40wt% resin material consisting of a polymer mainly composed of polytetramethylene terephthalate or a mixture thereof with at least one resin selected from AAS resin, ABS resin, AS resin, acrylic resin, rubber-modified acrylic resin, polycarbonate resin and polyester/polyether block copolymer, 1-40wt% fibrous filler having a fiber length of 300mu or below, such as glass fiber, 3- 58wt% inorg. filler having an average particle size D50 of 2-50mu, such as amorphous glass powder, and 1-25wt% inorg. filler having an average particle size D50 of 2mu or below, such as silica powder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition suitable for metallizing processing of molded articles mainly composed of polytetramethylene terephthalate, which has improved surface smoothness and excellent heat resistance. This invention relates to a resin composition suitable for metallizing processing, which has excellent heat resistance and rigidity and improved surface smoothness by blending a polymer mainly composed of methylene terephthalate with an inorganic filler having a specific particle size.

Glass fiber reinforced products of polytetramethylene terephthalate have excellent moldability, mechanical properties, heat resistance, etc., and are widely used as engineering plastics because of their well-balanced performance. The drawback of this glass fiber reinforced product, which is that it tends to warp during molding, has been improved by using a combination of glass fiber and inorganic filler, and by blending pressure with other "combinations", and its uses are further expanding.

Taking advantage of the excellent properties of polytetra-ramethylene terephthalate, especially its heat resistance, studies are underway to apply metallization to reflectors of lighting equipment and the like.

However, after a detailed evaluation and study of the adaptability of reinforced polytetramethylene 1/phthalate resin to reflector materials, etc., it was found that although there were no problems with heat resistance or mechanical properties, 1 was strengthened with a normal reinforcing agent. , the surface smoothness of the molded product is significantly inferior, and if the molded product is subjected to aluminum vapor deposition treatment, for example,
The beautiful mirror surface reflected the light 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 inventors of the present invention aimed to improve the surface smoothness of 9-reinforced polytetramethylene terephthalate. Heat resistance, rigidity, etc. will decrease.

However, it was discovered that by giving the reinforcing filler a specific particle size distribution, it was possible to achieve much better planar smoothness than simply blending a filler with a fine particle size, and to exhibit properties that were well-balanced in terms of heat resistance and rigidity. We have arrived at the present invention.

That is, 1. The gist of the present invention is that a polymer mainly composed of polytetramethylene terephthalate or such a polymer and AAS resin, ABS resin, AS resin,
A resin material made of a mixture with one or more resins selected from acrylic resins, rubber-modified acrylic resins, polycarbonate resins, and polyester-polyether block copolymers. A fibrous filler with an IAJ95 to 40M content and a fiber length of 300μ or less. (B) 1 to 40% by weight, an inorganic filler with an average particle diameter of 2 μ to 50 μ (C) 3 to 58
Weight factor, and average particle size. The present invention provides a resin composition having excellent surface smoothness and comprising 1 to 25% by weight of an inorganic filler (D) having a particle diameter of less than 2μ.

The resin material (A) constituting the composition of the present invention includes a polymer synthesized by a known method from tetramethine/glycol and terephthalic acid or dimethyl terephthalate;
Furthermore, polymers copolymerized with other dicarboxylic acid components and diol components in a range of 15 molar or less, and AAS resins with a weight ratio of 40 or less with these polymers, AB
S resin, AS resin, polycarbonate resin, polyester-polyether block copolymer.

Examples include mixtures with one or more resins selected from acrylic resins and rubber-modified acrylic resins. In particular, in the present invention, polytetramethylene terephthalate homopolymers and mixtures of polytetramethylene terephthalate and resins selected from the above are preferably used. Resin Ih (The ratio of At used in the resin composition is 95~
It is 405 to 40% by weight. If the proportion exceeds 95% by weight, there will be no reinforcing effect, and if the proportion is less than 40% by weight, the heat resistance will decrease.

Resin materials (As At, polytetramethylene terephthalate and AAS resin, ABS resin, AS with a weight ratio of 40 or less
Resin, polycarbonate resin.

When a mixture of a polyester-polyether block copolymer and one or more resins selected from acrylic resins and rubber-modified acrylic resins is used, compared to polytetramethylene terephthalate alone, it is possible to prevent sink marks from forming on molded products ( This makes it easy to obtain a material with high smoothness.

However, if the other resin components in the resin material (Al) exceed 4ON, the heat resistance decreases, which is not preferable.

The fibrous filler (B
JtL'l is called milled fiber, cut fiber, glass powder, etc. and is commercially available. Gypsum whiskers, potassium titanate whiskers,
Delicate metal fibers, processed mineral fibers, etc. are listed, and their fiber lengths are as follows.

The diameter is 300μ or less and the length/diameter ratio is 5 or more.

If the fiber length is long (the reinforcing effect will be high, but the appearance of the molded product will deteriorate, which is undesirable. These fibers may be used alone or in combination, and it is also preferable that the fibers be subjected to various surface treatments. Especially preferably used are glass milled or cut fibers and potassium titanate whiskers.

Such a fibrous filler (Bl) is added in an amount of 1 to 40 weight Jt% of the resin composition. Unfavorable because shape and appearance deteriorate.Especially 3-30'
t% range is preferred).

Furthermore, the average particle size used. is an inorganic filler with a diameter of 2μ or more and 50μ or less (C1 is amorphous glass powder,
One or more types selected from glass peas, crow flakes, talc, clay, kaolin, calcium metasilicate powder, dawsonite, silica powder, quartz powder, mica powder, metal powder, boron nitride powder, etc. be. The amount of inorganic filler (Cl) added is 3 to 58% by weight. If it is less than 3% by weight, the reinforcing effect will not be sufficient both mechanically and thermally, and if it exceeds 58% by weight, it will not be uniformly dispersed. This is not preferred because it is difficult to remove and the appearance deteriorates.

Furthermore, the average particle size used. is less than 2 lt (DJ includes various materials such as glass powder, talc, clay, lithopone, kaolin, calcium carbonate, calcium metasilicate L, silica powder, metal powder, titanium oxide, etc., and has an average particle size of As long as the average particle size is less than 2μ, it may be used alone or in combination of two or more.

If this is satisfied, the filler may have the same components as the filler (CJ). Particularly preferred is one having a particle size of 1 μm or less.

The additive amount of such a filler (DJ) is 1 to 25N. If the filler is less than 1%, the appearance improvement effect is insufficient; on the other hand, even if the addition amount exceeds 25% by weight, the appearance improvement effect is insufficient. This is not preferable because the effect is small and the reinforcing effect is also reduced.The amount of filler+D+ added is preferably in the range of 3% by weight to 20% by weight.

As the fillers fc) and (DJ), fillers that have undergone various surface treatments are also preferably used. For example, fillers that have been treated with a silane coupling agent, a fatty acid treatment, a titanate coupling agent, etc. are used.

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. Treatment 9: For example, plating, metal vapor deposition, sputtering treatment, etc. can give a good metal appearance, making it suitable for use in glue flaps, exterior materials, and housing materials such as automobiles and electrical products that require high heat resistance and mechanical properties. suitable.

Stabilizers such as antioxidants, dyes and pigments, modifiers such as epoxy resins, mold release agents, and even flame retardants can be added to such resin compositions as necessary. In particular, if the flame retardant is volatilized or sublimated at high temperatures, it will damage the appearance of the molded product) Bleed type flame retardants 2 For example, brominated epoxy resin, brominated polycarbonate oligomer, brominated polyester oligomer It is preferable to use polymeric flame retardants such as.

To carry out the present invention, any method well known to those skilled in the art can be applied.2 For example, sufficiently dried pellets of polytetramethylene terephthalate or polytetramethylene terephthalate and other polymers, a fibrous filler and each particle. Examples include a method of mixing fillers of different diameters in a blender and then melt-mixing them through an extruder.

This will be explained in more detail below with reference to Examples.

Examples 1-4. 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, mixed for 5 minutes in a V-type blender, and then mixed for 6 minutes.
The resin composition was melt-extruded using a 5φ single vent extruder at an extrusion temperature of 250° C. and shaped into pellets to obtain a resin composition.

This was done using a multi-machine 5J35B injection molding machine at a temperature of 2.
60℃, mold temperature 100"C"'C: radiation 11J/j
A K-shaped molded product was obtained for various evaluations.

Table 1 shows the results of various evaluations using these molded products.
Shown below.

In the table, the appearance of the molded products was evaluated using a 60x100x3 x 1 molded plate, and those with particularly few sink marks were rated ◎, those with few and good were rated O, and those with noticeable sink marks were rated Δ~×
And so. In addition, surface smoothness was determined visually.

The molded article obtained from the composition of the present invention has no sink marks.

It had excellent appearance and surface smoothness without warping, and showed high heat resistance. - If the fiber length is too long, such as those on the gal axis side 1 and 2, the surface will be extremely rough and the smoothness will be poor, and if it does not contain a fibrous filler and only has a small particle size, as in Comparative Example 3, the surface will be smooth. Although the properties were good, the heat resistance and mechanical properties were poor.

Next, using the compositions obtained in Examples 3 to 4 and Comparative Examples 1 to 3, 12 (1+++ mφ, depth 15 mm) was prepared.

A circular lid with a thickness of 2 mm is heated to a cylinder temperature of 260°C.

Injection molding was carried out at a mold temperature of 100° C., and an acrylic ultraviolet curing paint was sprayed on the inside to a thickness of about 20 μm and cured using a high-speed mercury lamp. This molded product is vapor-deposited with aluminum, coated with an acrylic-urethane clear paint, and baked at 150°C for 30 minutes.The vapor-deposited product obtained from the composition of the present invention exhibits a good mirror surface and has little glue on the molded product. Met.

This is sufficient for use in critical applications of flefter isoluminance and focus.

-10,000 The compositions of Comparative Examples 1 and 2 that were vapor-deposited had sink marks, and the roughness of the surface was even more noticeable due to vapor deposition, resulting in a satin-like appearance, which was completely inferior in appearance.

The vapor-deposited product obtained in Comparative Example 3 also had excellent smoothness as shown in Table 17J1, but it had sink marks and was particularly low in heat resistance, so warpage was observed in which the center of the 120φ bottom part rose after vapor deposition.

Namely, as in the composition of the present invention, 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. 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 Example 5 Polytetramethylene ethylene terephthalate having an intrinsic viscosity [η] of 0.86), ABS resin (graft polymer of acrylonitrile/polybutadiene/styrene with a weight specific strength of 20/30150), diameter approximately 10μ, fiber Summary 250μ glass milled fiber, average particle size. is 30μ glass powder.

Litopone having an average particle size of 0.5 μm, a brominated epoxy resin as a flame retardant, and antimony trioxide having an average particle size of 1 μm were weighed in the proportions shown in Table 2, and mixed for 5 minutes using a ■ type blender. The resin composition of the present invention was obtained in the same manner as in Example 1 using a 65φ mm/glubento extruder.

This is done on each machine 5J35B injection molding machine at a cylinder temperature of 2.
60℃, mold temperature 100℃, 120mxφ, depth 15
A circular lid with a thickness of 2mm+ was molded. This is a sink,
It had a good appearance with no warpage. Aluminum was deposited on the inside of this molded product in exactly the same manner as in Example 3, and
After baking for 0 minutes, the top coated product had no molding warp, had a good mirror surface, and had excellent heat resistance.

Furthermore, 10 burners with a flame length of approximately 2 crrL were installed on 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 exhibits excellent surface smoothness with a good appearance due to the metallization process.

Table 2 31

Claims (1)

[Claims] (1) Polymers mainly composed of polytetramethylene terephthalate or such polymers and AASAs resins, BS resins, As resins, and acrylic resins. A resin material (A) consisting of a mixture with one or more resins selected from rubber-modified acrylic resin, polycarbonate resin, and polyester-polyether block copolymer.
Fibrous filler (B) 1 to 40% by weight with a fiber length of 300μ or less, and 3 to 58% by weight of an inorganic filler (C) with an average particle diameter DI10 of 2μ or more and 50μ or less. and average particle diameter. Inorganic filler (D
) A resin composition containing 1 to 25% by weight and having excellent surface smoothness.