KR20010111162A - Polyester of the improved UV-cut-off property for extrusion blow mold - Google Patents

Abstract

The present invention relates to a polyester copolymer for extrusion blow molding, which is within 92 mol parts of dimethyl terephthalate, 1 to 97 mol parts of naphthalenedicarboxylate, 3 to 30 mol parts of dimethyl isophthalate, 96 to 100 mol parts of ethylene glycol and multifunctional branching. It consists of 0.01 ~ 4 mole parts of agent, which shows high melt viscosity without solid phase polymerization and is non-crystalline so that crystallization does not occur during processing, and it can block not only ultraviolet wavelength 280 ~ 320nm but also ultraviolet wavelength 320 ~ 380nm. It can be applied as a structure.

Description

Polyester of the improved UV-cut-off property for extrusion blow mold}

The present invention relates to a polyester resin for extrusion blow molding, and more particularly, to a polyester copolymer having high melt viscosity and non-crystalline, without crystallization during processing, and excellent UV blocking ability without solid phase polymerization. will be.

In general, polyester resins are excellent in mechanical and chemical properties, and are widely used in fibers, bottles, engineering plastics, films, sheets, and the like.

In particular, polyester resins having excellent melt strength are extrusion-blow molds which are directly blown without the process of making preforms, unlike conventional reform blow molding after making preforms. Is possible.

The extrusion blow molding process has advantages in that it is possible to manufacture various types of molded products, compared to the injection blow molding process, but inevitably, a large amount of residual melt is generated, and the hardness is low, so that the impact strength is weak when used as a molded product such as a bottle. It has a disadvantage.

Therefore, the extrusion blow molding polyester must not only have a high melt strength, but also must compensate for impact resistance through modification of a suitable resin.

In order to increase the melt strength of the polyester, a method of simply increasing the intrinsic viscosity of the polymer to 1.05 or more through a solid phase polymerization reaction has been used, but this does not represent a sufficient melt strength to enable the extrusion blow molding as well as the cost burden in the manufacturing process. There was a lot of difficulties in practical use because it was not possible.

In addition, a method of using a branching agent is widely known to prepare a polyester having high melt strength. For example, polyhydric acid or polyhydric alcohol having three or more functional groups is used to induce crosslinking in a molecular structure. A method is mentioned. According to this method, the melt strength of the polymer can be easily increased to the extent that extrusion blow molding is possible, but it is difficult to control the degree of polymerization because the gelation potential is high not only in the polycondensation reaction but also in the solid phase polymerization reaction step. In addition, this method requires polyester solid-state polymerization for most of the extrusion blow molding, even if it is not gelated in the polycondensation reaction. It can cause fatal damage such as fish eye, and sometimes it can't even melt.

This means that the degree of polymerization rises above the critical gel point set forth by P.J. Flory through the solid phase polymerization reaction.

Therefore, the extrusion blow molding polyester is required to exhibit a high melt viscosity and to be amorphous even without performing solid phase polymerization, and is required to be UV-blocking in consideration of being applied to outdoor structures and the like.

In order to satisfy this problem, various studies have been carried out. For example, US Pat. No. 5,229,432 describes the production of polyethylene terephthalate having a high melt viscosity by applying a polyfunctional monomer as a branching agent during the production of polyethylene terephthalate. It was.

However, the resin obtained here has a disadvantage in that extrusion blow molding is very difficult due to the high crystallization rate, and there is a disadvantage in that UV blocking ability is insufficient.

In US Pat. No. 5,523,382, diethylene glycol is applied to manufacture polyester for extrusion blow molding. However, in this case, the molecular weight does not increase sufficiently, there is a disadvantage in that the solid phase polymerization, and also the UV blocking ability was insufficient.

Accordingly, it is an object of the present invention to provide a polyester copolymer that exhibits high melt viscosity, is amorphous, and has excellent UV blocking ability even without performing solid phase polymerization.

The polyester copolymer of the present invention for achieving the above object is within 92 mol parts of dimethyl terephthalate or terephthalic acid, 1 to 97 mol parts of naphthalenedicarboxylate, 3 to 30 mol parts of dimethyl isophthalate or isophthalic acid, 96 to 100 ethylene glycol The molar part and the multifunctional branching agent are characterized by consisting of 0.01 to 4 mole parts.

The present invention will be described in more detail as follows.

The present invention relates to a polyester copolymer having rheological properties suitable for extrusion blow molding.

In preparing the polyester copolymer of the present invention, dimethyl terephthalate is preferably added within 92 mol parts, and naphthalenedicarboxylate is preferably added in 1 to 97 mol parts. If the added amount of naphthalenedicarboxylate is less than 1 mole part, the blocking force in the ultraviolet wavelength range of 320 to 380 nm is significantly reduced.

The multifunctional branching agent added in the present invention is glycerol, trimethylolpropane, pentaerythritol, 1,2,6-hexanetriol, sorbitan, 1,1,4,4-tetrakishydroxymethylcyclohexane, Polyhydric alcohols such as tris (2-hydroxyethyl) isocyanorate, dipentaerythritol or alkylene oxide addition reactants; Hemimelic acid, hemimelic anhydride, trimellitic anhydride, trimesic acid, pyromellitic acid, pyromellitic anhydride, 1,1,2,2-ethanetetracarboxylic acid, 1,1,2-ethanetricar It can use selecting from polyhydric acid, such as an acid, 1,3,5-pentane tricarboxylic acid or 1,2,3,4-cyclopentane tetracarboxylic acid.

It is preferable that the addition amount of such a polyfunctional branching agent is 0.01-4 mol part, Preferably it adds so that it may be 0.05-2 mol part. If the addition amount of the multifunctional branching agent is less than 0.01 mole parts, it is difficult to realize high viscosity, if more than 4 mole parts there is a disadvantage that a large amount of cosmetic melt occurs.

The resin thus obtained can effectively block not only the ultraviolet wavelength range of 280 to 320 nm but also the wavelength of 320 nm to 380 nm of ultraviolet rays, and is suitable for use in cosmetic containers and outdoor structures, and is transparent and rheologically easy for extrusion blow molding and processing. The parison obtained at the time of manufacture has excellent shape stability and wide range of processing temperature, so it can be manufactured in various sizes and thicknesses.

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

Example 1

80 mol parts of dimethyl terephthalate, 5 mol parts of naphthalenedicarboxylate, 15 mol parts of dimethyl isophthalate, 200 mol parts of ethylene glycol, and 0.4 mol part of trimethylolpropane were added to a container, 500 ppm of magnesium acetate was added thereto, and methanol was gradually heated to 230 ° C. Removed. After adding 450 ppm of phosphoric acid, 300 ppm of antimony oxide was added and vacuum was applied while raising the temperature to 280 ° C.

The composition of the polymer thus obtained was 80 mol parts of dimethyl terephthalate, 5 mol parts of naphthalenedicarboxylate, 15 mol parts of dimethylisophthalate, 99.4 mol parts of ethylene glycol, and 0.4 mol parts of trimethylolpropane.

Example 2

20 mol parts of dimethyl terephthalate, 70 mol parts of naphthalenedicarboxylate, 10 mol parts of dimethyl isophthalate, 200 mol parts of ethylene glycol and 0.4 mol part of trimethylolpropane were added to a container, 500 ppm of magnesium acetate was added thereto, and methanol was gradually heated to 230 ° C. Was removed. After adding 450 ppm of phosphoric acid, 300 ppm of antimony oxide was added thereto, and a vacuum was applied while raising the temperature to 280 ° C.

The composition of the polymer thus obtained was 20 mol parts of dimethyl terephthalate, 70 mol parts of naphthalenedicarboxylate, 10 mol parts of dimethyl isophthalate, 99.4 mol parts of ethylene glycol, and 0.4 mol parts of trimethylolpropane.

Example 3

30 mol parts of dimethyl terephthalate, 50 mol parts of naphthalenedicarboxylate, 20 mol parts of dimethyl isophthalate, 200 mol parts of ethylene glycol, and 0.4 mol part of trimethylolpropane were added to the container, 500 ppm of magnesium acetate was added, and methanol was gradually heated to 230 ° C. Was removed. After adding 450 ppm of phosphoric acid, 300 ppm of antimony oxide was added thereto, and a vacuum was applied while raising the temperature to 280 ° C.

The composition of the polymer thus obtained is 30 mol parts of dimethyl terephthalate, 50 mol parts of naphthalenedicarboxylate, 20 mol parts of dimethylisophthalate, 99.4 mol parts of ethylene glycol, and 0.3 mol parts of pentaerythritol.

Example 4

80 mole parts of terephthalic acid, 5 mole parts of naphthalenedicarboxylate, 14.1 mole parts of isophthalic acid, 100 mole parts of ethylene glycol, and 0.6 mole parts of trimellitic anhydride were put into a vessel and vacuum was applied while raising the temperature to 280 ° C.

Comparative example

80 mol part of dimethyl terephthalate, 20 mol part of dimethyl isophthalate, and 200 mol part of ethylene glycol were put into a container, 500 ppm of magnesium acetate was added, and methanol was removed, heating up gradually to 230 degreeC. After adding 450 ppm of phosphoric acid, 300 ppm of antimony oxide was added and vacuum was applied while raising the temperature to 280 ° C.

The composition of the obtained polymer was 80 mol parts of dimethyl terephthalate, 20 mol parts of dimethyl isophthalate, and 100 mol parts of ethylene glycol.

Experimental Example

For the polyester resins obtained according to Examples 1 to 4 and Comparative Examples, UV blocking properties, crystallization formation, and melt viscosity were measured, and the results are shown in Table 1 below.

Here, the blocking property at the ultraviolet wavelength of 280 ~ 380nm was measured by UV spectrophotometer after preparing the sample into a sheet, and the formation of crystallization was observed by heating the differential scanning calorimeter (DSC) to 10 ℃ per minute and the presence of the melting temperature It was. And melt viscosity was measured by capillary rheometer (share rate 10sec <^-1> , temperature 210 degreeC).

Example 1 Example 2 Example 3 Example 4 Comparative example UV protection Great Great Great Great Bad Melt Viscosity (Pas) 6 × 10 ⁴ 7 × 10 ⁴ 8 × 10 ⁴ 7 × 10 ⁴ 1 × 10 ³ Melting Point Presence (Crystalline) none none none none has exist

From the results of Table 1, it can be seen that the polyester resin according to the present invention is excellent in UV protection, high melt viscosity and amorphous.

As described in detail above, the polyester copolymer comprising naphthalenedicarboxylate, a polyfunctional branching agent and ethylene glycol according to the present invention exhibits high melt viscosity without solid phase polymerization and is amorphous and therefore crystallized during processing. It can block not only the ultraviolet wavelength 280 ~ 320nm region but also the ultraviolet wavelength 320 ~ 380nm can be applied to cosmetic containers and outdoor structures.

Claims (5)

Extrusion injection molding consisting of dimethyl terephthalate or terephthalic acid within 92 mol parts, 1 to 97 mol parts naphthalenedicarboxylate, 3 to 30 mol parts dimethyl isophthalate or isophthalic acid, 96 to 100 mol parts ethylene glycol and 0.01 to 4 mol parts polyfunctional branching agent Polyester copolymer. The multifunctional branching agent of claim 1, wherein the multifunctional branching agent is glycerol, trimethylolpropane, pentaerythritol, 1,2,6-hexanetriol, sorbitan, 1,1,4,4-tetrakishydroxymethylcyclohexane , Tris (2-hydroxyethyl) isocyanorate, dipentaerythritol, alkylene oxide addition reactant, hemimelic acid, hemimelic anhydride, trimellitic anhydride, trimesic acid, pyromellitic acid, pyromelli Ticic anhydride, 1,1,2,2-ethanetetracarboxylic acid, 1,1,2-ethanetricarboxylic acid, 1,3,5-pentanetricarboxylic acid and 1,2,3,4-cyclo An extrusion blow molding polyester copolymer, characterized in that at least one member selected from the group consisting of pentane tetracarboxylic acid. The polyester copolymer for extrusion blow molding according to claim 1, wherein the melt viscosity is 5 × 10 ³ to 9 × 10 ⁵ Pa · s at a shear rate of 10 sec ⁻¹ and a temperature of 210 ° C. The polyester copolymer for extrusion blow molding according to claim 1, wherein a melting point is not observed by a differential scanning calorimeter. The polyester copolymer for extrusion blow molding according to claim 1, wherein the polyester copolymer for extrusion blow molding can block up to an ultraviolet wavelength region of 280 to 380 nm.