KR19980061619A - Polytrimethylene Terephthalate Resin Composition - Google Patents

Abstract

The present invention is composed of polytrimethylene terephthalate resin, polytrimethylene terephthalate-sodium salt, inorganic fiber or inorganic filler and polyethylene wax, and the cycle time is shortened in the mold temperature range of 80 to 110 ° C, resulting in high heat resistance, high crystallinity, The present invention relates to a polytrimethylene terephthalate resin composition having excellent moldability and various mechanical properties.

Description

Polytrimethylene Terephthalate Resin Composition

The present invention is composed of polytrimethylene terephthalate resin, polytrimethylene terephthalate-sodium salt, inorganic fiber or inorganic filler and polyethylene wax, and the cycle time is shortened in the mold temperature range of 80 to 110 ° C, resulting in high heat resistance, high crystallinity, The present invention relates to a polytrimethylene terephthalate resin composition having excellent moldability and various mechanical properties.

Polytrimethylene terephthalate (hereinafter referred to as PTT) has excellent mechanical properties, chemical resistance, elasticity, electrical properties, and heat resistance, so it can be used for electric insulation parts, automobile parts, and daily necessities. It is a polymer that is expected to be applied in the field.

However, since PTT resin is not fast enough to crystallize at 80 ~ 110 ℃ of mold temperature during injection molding, it is possible to shorten the molding cycle, improve the surface characteristics of molded products and improve releasability, and make use of the unique characteristics of PTT resin. It is necessary to improve the crystallization rate.

Representative methods for improving the crystallization rate of the existing polyester resin is a method for reducing the crystallization rate using a crystal nucleation agent and a growth agent. For example, US Pat. No. 3,368,975 uses an inorganic filler such as talc, calcium silicate, magnesium oxide, or an organic crystallization accelerator having a polyoxyalkylene chain and an epoxy group to improve the crystallization rate or to unsaturated carboxylate or bisamide type. The method of improving the crystallization rate using a compound, etc. are introduced.

However, this method alone has a disadvantage in that the distribution of additives and the limitations of nuclear growth are deteriorated, resulting in deterioration of mechanical properties and formability and lengthening of molding time.

Accordingly, the present invention provides a new PTT resin which shortens the molding cycle within about 20 seconds in the mold temperature range of 80 to 110 ° C, has not only heat resistance, moldability, and high crystallinity, but also excellent tensile strength, flexural strength, and impact strength. The purpose is to provide a composition.

The present invention is 1 to 10 parts by weight of PTT sodium salt represented by the following structural formula (1) to 30 to 85 parts by weight of polytrimethylene terephthalate resin having an intrinsic viscosity of 0.4 to 1.0, and 1 to 55 parts by weight of inorganic fibers or inorganic fillers. It is a polytrimethylene terephthalate resin composition characterized by containing 1-10 weight part of polyethylene wax of the molecular weight 1,000-5,000.

Wherein n is an integer of 2-50.

Hereinafter, the present invention will be described in detail.

PTT resin composition of the present invention is to improve the processability and mold release property of the PTT resin, the basic component, the PTT-sodium salt used as the first nuclear growth agent and the inorganic fiber or inorganic filler used as the second nuclear growth agent, and injection molding Made of wax.

The PTT resin used in the present invention has an intrinsic viscosity of 0.4 to 1.0, but if the intrinsic viscosity of the PTT resin is less than 0.4, mechanical properties, heat resistance, and releasability deteriorate. In addition, there is a disadvantage that the crystallization rate is slow.

The PTT-sodium salt of Structural Formula (1) used as the first nucleus growth agent in the present invention is a crystallization accelerator, and has the same repeating ester molecular structure as PTT, so it has excellent compatibility with PTT resins and is very good for crystal formation and growth. It is useful and especially the crystal size is not too large and the distribution is uniform, which greatly improves the mechanical and thermal properties of the PTT resin composition.

It is preferable to use the PTT-sodium salt whose molecular weight is 1,000-10,000, and uses 1-10 weight part with respect to 30-85 weight part of PTT resin.

When the amount of PTT-sodium salt is less than 1 part by weight, almost no improvement of physical properties is observed, and when the amount of PTT-sodium salt is more than 10 parts by weight, economic efficiency and workability are deteriorated.

In the present invention, the inorganic fiber or the inorganic filler used as the second nuclear growth agent is used in an amount of 1 to 55 parts by weight based on 30 to 85 parts by weight of the PTT resin. When the amount of the inorganic fiber or the inorganic filler is less than 1 part by weight, there is a problem that the tensile strength, the flexural strength, the impact strength, and the like decrease.

In the present invention, any one or more selected from glass fiber, carbon fiber, boron fiber and poly (paraphenylene sulfide) fiber may be used as the inorganic fiber, and the inorganic filler may be talc, mica, fat sugar, calcium carbonate, kaolin and silica. Any one or more selected from among them may be used.

Polyethylene wax used in the present invention to increase the processability and releasability and to promote crystallization has a molecular weight of 1,000 to 5,000, using 1 to 10 parts by weight based on 30 to 85 parts by weight of the PTT resin, less than 1 part by weight When used, it does not exhibit suitable release property and it is difficult to obtain a crystallization promoting effect, and when it exceeds 10 parts by weight, workability and moldability are deteriorated.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the Examples.

<Examples 1-5>

After drying PTT resin having an intrinsic viscosity of 0.78 for 6 hours at 150 ° C., 3.2 mm glass fiber, an inorganic filler, polyethylene wax having a molecular weight of 2,200, and sodium benzoate 3 parts by weight, and a PTT-sodium salt having a molecular weight of 5,000 were given in Table 1 below. Mix evenly in proportions.

Subsequently, the mixture was melt-kneaded and cooled in a barrel temperature of 255 ° C. and a 46 mm diameter extruder, followed by cooling to prepare pellets. The pellets were hot-air dried at 130 ° C. for 4 hours, followed by cylinder temperature of 255 ° C., mold temperature of 80 ° C., and injection. A standard specimen is prepared by injection molding at a pressure of 150 bar, a cooling time of 10 seconds, and a cycle time of 20 seconds.

<Examples 6-8>

The same procedure as in Examples 1 to 5 was carried out except that a PTT resin having an intrinsic viscosity of 0.88 was used.

(Unit: parts by weight) Example PTT resin Fiberglass Mica Polyethylene wax PTT-Sodium Salt One 67 20 10 One 2 2 67.5 30 - One 1.5 3 62 30.5 4.5 1.5 1.5 4 56.5 30 10 1.5 2 5 52 45 - 2 One 6 77 20 - One 2 7 67 30 - One 2 8 61.5 35 - 2 1.5

<Comparative Examples 1-7>

Except for the type and content of each component as shown in Table 2, it is carried out in the same manner as in Examples 1 to 5.

(Unit: parts by weight) Comparative example PTT resin Fiberglass Talc Mica Polyethylene wax PTT-Sodium Salt One 100 - - - - - 2 80 20 - - - - 3 70 30 - - - - 4 60 30 - 10 - - 5 65 30 5 - - - 6 68 30 - - 2 - 7 67 30 - - - 3

The pellets of the PTT resin compositions prepared according to the above Examples and Comparative Examples were manufactured as specimens of ASTM standards in a 38 mm injection machine having a barrel temperature of 250 ° C. to 270 ° C., and the physical properties thereof were shown in Table 3 below.

division Tensile Strength (㎏ / ㎠) Dysplasia Flexural Strength (㎏ / ㎠) Impact strength (㎏㎝ / ㎠) Heat deflection temperature (℃) Surface condition Example 1 1,400 , 2,000 9 210 , 2 1,700 , 2,300 11 225 , 3 1,600 , 2,200 19.5 230 , 4 1,400 , 2,100 8.5 210 , 5 1,850 , 2,600 13 230 , 6 1,450 , 2,100 9 215 , 7 1,750 , 2,350 11.5 225 , 8 1,650 , 2,200 10 230 , Comparative Example 1 700 × 1,100 4 70 × 2 1,100 × 1,600 6.5 75 × 3 1,400 × 2,000 8 80 × 4 1,200 × 1,600 7 85 × 5 1,300 × 1,700 7 81 × 6 1,500 △ 2,100 9 140 × 7 1,550 △ 2,100 9 180 ,

Tensile strength was measured by ASTM 638, flexural strength was ASTM 790, impact strength was ASTM D 256 (notch), and heat deformation temperature was measured by ASTM D 648 (18.6 ㎏ / ㎠) method. △, the state that does not adhere to the mold but does not adhere automatically by the eject pin, △, the state that is automatically released by the eject pin and exhibits excellent release property as ○, and the surface state is rippled on the surface. The state where the pattern occurs or the inorganic material protrudes is indicated by ×, without the wave pattern, the gloss is excellent, and the surface is smooth.

PTT resin composition according to the present invention is a thermoplastic molding material excellent in processability and formability, and excellent in mechanical, thermal, and electrical properties than PTT resin composition according to the present invention because it is molded at a low cycle temperature at a fast cycle time. Comparable excellent heat resistance can be applied to a variety of applications, such as electronic components, automotive electronic parts, hot air balloon housing.

Claims (4)

30 to 85 parts by weight of polytrimethylene terephthalate resin having an intrinsic viscosity of 0.4 to 1.0, 1 to 10 parts by weight of polytrimethylene terephthalate-sodium salt represented by the following structural formula (1), and inorganic fibers or inorganic fillers 1 to A polytrimethylene terephthalate resin composition comprising 55 parts by weight and 1 to 10 parts by weight of polyethylene wax having a molecular weight of 1,000 to 5,000. Wherein n is an integer of 2-50. The resin composition according to claim 1, wherein the polytrimethylene terephthalate-sodium salt of the structural formula (1) has a molecular weight of 1,000 to 10,000. The resin composition according to claim 1, wherein the inorganic fiber is at least one selected from glass fiber, carbon fiber, boron fiber and poly (paraphenylene sulfide) fiber. The resin composition according to claim 1, wherein the inorganic filler is at least one selected from talc, mica, fat sugar, calcium carbonate, kaolin, and silica.