JP2003041100A - Polyester resin composition and extruded hollow product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a extruded hollow product easily on a large scale especially by using a regenerated polyester resin as a raw material. SOLUTION: Troubles of clogging of a slit 16 for vacuum suctioning in a vacuum former 7 during hollow extrusion molding is solved by adding a thickening agent having a melt flow rate(MFR) of <=20 g/10 min according to the condition 4 in Table 1 of JISK7210, a molecular weight-increasing agent having a functional group reactive with the polyester resin, and polycarbonate and/or an acrylonitrile-ethylene-styrene resin to the polyester resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester resin composition and a hollow profile extrusion molded article using the polyester resin composition as a material.

[0002]

2. Description of the Related Art Polyester resin is used in large quantities as a material for, for example, PET bottles, and therefore a large amount of waste polyester resin is also generated. It is considered that the above waste polyester resin material is pulverized, melted and pelletized and used again as a material for various molded products as a recycled polyester resin. However, the polyester resin is deteriorated by heating during the regeneration treatment, the molded product obtained from the recycled polyester resin is inferior in impact resistance, and it is almost impossible to regenerate it into a molded product having a commercial value. For this reason, it has been conventionally practiced to add a modifier such as a synthetic rubber or an elastomer to the recycled polyester resin to improve the impact resistance.

[0003]

However, even if the above-mentioned modifier is added to the recycled polyester resin, it is difficult to sufficiently restore the impact resistance. In particular, when a hollow profile extrusion molded product such as a square pipe is produced by using a recycled polyester resin as a material, the resin extruded from the die of the extruder is shaped through a vacuum former and is cooled and solidified. When the resin is passed through a vacuum former, a serious problem occurs that the resin is clogged in the vacuum suction slit of the vacuum former.

[0004]

In order to solve the above-mentioned problems, the present invention uses a polyester resin having a melt flow rate (MFR) of 20 g according to JIS K7210 Table 1, Condition 4.
Provided is a polyester resin composition to which a thickener for 10 minutes or less, a polymerizing agent having a functional group capable of reacting with the polyester resin, and a polycarbonate and / or an acrylonitrile / ethylene / styrene resin are added. It is a thing. The present invention is particularly useful for recycled polyester resin, and the thickener and the polymerizing agent, or the thickener and the polymerizing agent, and the polycarbonate and / or acrylonitrile-ethylene-styrene resin are previously prepared. It is preferable to mix and add to the polyester resin as a polyester resin modifier. Further, the present invention provides a hollow profile extrusion-molded article produced by profile-molding the above polyester resin composition. The present invention is described in detail below.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION [Polyester Resin A] The polyester resin of the present invention is a resin obtained by an esterification reaction of a divalent or higher polyhydric alcohol and a divalent or higher carboxylic acid, for example polyethylene terephthalate ( P
ET), polybutylene terephthalate and the like. The present invention is particularly useful for recycled polyester resins.

[Thickener] In the present invention, particularly for recycled polyester resin having a low molecular weight due to the regeneration treatment and thus a low melt viscosity, the melt viscosity is increased and melted from the die of the extruder. It is desirable to add a thickening agent in order to prevent a drawdown phenomenon in which the product sags under its own weight. A resin or an elastomer having a high melt viscosity is selected as such a thickener. Examples of the thickener include polyethylene, polypropylene, ethylene-ethyl acrylate copolymer (EE
A) or other polyolefin resin or elastomer, styrene-butadiene-styrene block copolymer (SB
S), a styrene-based elastomer such as styrene-ethylene-butadiene block copolymer (SEBS), or a polymer alloy of the above polyolefin-based resin and the above styrene-based elastomer and / or synthetic rubber.
Examples of the synthetic rubber include acrylic rubber, butyl rubber, ethylene-propylene rubber (EPR, EPDM),
Silicon rubber, urethane rubber, fluoride rubber, polysulfide rubber, graft rubber, butadiene rubber, isoprene rubber, chloroprene rubber, polyisobutylene rubber, polybutene rubber, isobutene-isoprene rubber, acrylate-butadiene rubber, styrene-butadiene rubber (SB
R), acrylonitrile-butadiene rubber (NBR),
Pyridine-butadiene rubber, styrene-isoprene rubber, acrylonitrile-chloroprene rubber, styrene-
There are chloroprene rubber, etc. As a thickener having a high thickening effect, there is a polymer alloy of polypropylene and the above synthetic rubber. Further, as the above synthetic rubber, EPR, EPDM or SBR having good compatibility with polypropylene is desirable. Further, when the above polymer alloy is used as a thickening agent in a recycled polyester resin, the resin does not cause yellowing or blocking when preliminarily dried after extrusion and water cooling.

The melt flow rate (MF) of the above thickener
R) is JIS K7210 Table 1 Condition 4 (Test temperature 190
0.5 to 20 g / 10 minutes, preferably 0.5 to 1 by a measuring method based on the test load of 21.18 (N).
It is 0 g / 10 minutes, more preferably 0.5 to 5 g / 10 minutes. The above-mentioned thickener is usually added in an amount of 3 parts by weight or more based on 100 parts by weight of the polyester resin, preferably 3-100 parts by weight.
Parts by weight are added. When the addition amount of the above thickener is less than 3 parts by weight, the thickening effect is not remarkable. Further, the thickening effect of the above-mentioned thickening agent does not change much even if it is added in excess of 100 parts by weight with respect to 100 parts by weight of the polyester resin, and it tends to be saturated. The amount of 100 parts by weight or less is sufficient, and when the addition amount of the thickening agent exceeds 100 parts by weight, the compatibility between the polyester resin and the thickening agent is not so good and phase separation may occur. However, it is not preferable that the addition amount of the thickening agent is more than 100 parts by weight, since this will impair the appearance of the molded product.
Further, when the polyester resin is a recycled polyester resin such as recycled PET, it is not preferable that the amount of the thickening agent added is large from the viewpoint of recycling that resources are effectively used. In the present invention, the thickener not only increases the melt viscosity of the polyester resin, but also improves heat resistance, impact resistance, dimensional stability, rigidity and the like.

[Polymerizing agent] By increasing the molecular weight of the polyester resin whose molecular weight has been lowered by the regeneration treatment, the melt viscosity is increased, and the mechanical strength (rigidity, impact resistance, etc.) of the molded product to be molded. It is desirable to add a polymerizing agent in order to impart. The polymerizing agent also functions as a compatibilizing agent for the thickening agent added to the polyester resin. As the polymerizing agent used in the present invention, a resin or elastomer having a functional group capable of reacting with a polyester resin is used. Examples of the functional group that reacts with the polyester resin include an epoxy group, a carboxyl group, and an isocyanate group, and the epoxy group is preferable from the viewpoint of having high reactivity with the polyester resin. Examples of the resin or elastomer having such a functional group include ethylene-glycidyl methacrylate (GMA) copolymers, ethylene-acrylic acid copolymers, ethylene-vinyl isocyanate copolymers and other ethylene-based copolymers, and the above ethylene-based copolymers. Polystyrene-grafted ethylene-based copolymer obtained by graft copolymerizing styrene with a polymer, epoxy group-containing SBS, epoxy group-containing SEBS, epoxy group-containing EEA, carboxyl group-containing SBS, carboxyl group-containing SEBS, carboxyl group-containing EEA, etc. . Further, it is desirable that the difference in the solubility parameter between the polymerizing agent and the thickener is within 1.

It is desirable to select a polymerizing agent having the same skeleton as the thickening agent used. For example, the thickener may be polyethylene, EEA, EPR or EP.
In the case of an olefin-based thickener such as DM, an olefin-based polymerizing agent such as an ethylene-glycidyl methacrylate copolymer, an ethylene-acrylic acid copolymer, an ethylene-vinyl isocyanate copolymer, etc. as a polymerizing agent. When SBS or SEBS is selected as the thickener, SBS or SEBS polymerizing agents such as epoxy group-containing SBS or SEBS, carboxyl group-containing SBS or SEBS are selected. The above-mentioned polymerizing agent is usually 0.3 to 1 with respect to 100 parts by weight of the polyester resin.
00 parts by weight, preferably 1.0 to 20 parts by weight.
If the addition amount of the above-mentioned polymerizing agent is less than 0.3 parts by weight, the polymerizing effect and the compatibilizing effect with the thickening agent are not sufficiently exhibited, and even if it is added in excess of 100 parts by weight, the effect is not exhibited. It saturates without any noticeable change.

The mixing ratio of the thickening agent and the polymerizing agent mixed in the polyester resin is usually 1: 1 to 1
A 0: 1 weight ratio is desirable. That is, even if the addition amount of the polymerizing agent is less than that of the thickener,
If it is / 10 or more, the polymerizing effect is sufficiently exhibited,
When added in excess of the thickener, the polymer effect saturates and extrusion moldability is impaired.

[Polyester Resin Modifier] The polyester resin modifier may be prepared by mixing the thickener and the polymerizing agent. In this case, the mixing ratio of the thickener and the polymerizing agent is usually preferably 1: 1 to 10: 1 by weight. The modifier is usually added in an amount of about 10 to 20% by weight with respect to the polyester resin.

[Polycarbonate and / or Acrylonitrile / Ethylene / Styrene Resin] In the present invention, in addition to the above polyester resin modifier, polycarbonate (PC) and / or acrylonitrile / ethylene / styrene resin is further added.
Styrene resin (AES) is added. The PC and / or AES is usually added in an amount of 5 to 20 parts by weight based on 100 parts by weight of the polyester resin containing the modifier. If the amount of PC and / or AES added is less than 5 parts by weight, the effect of addition will not be noticeable, and even if it is added in excess of 20 parts by weight, the effect of addition will not be further improved, and there is a problem of compatibility. The physical properties and surface properties of the polyester resin molded product may be adversely affected.

[Other Components] In the present invention, in order to further improve the heat resistance, impact resistance, dimensional stability, rigidity and the like of the polyester resin, for example, styrene-isoprene rubber (SIR), styrene-ethylene copolymer Coalesced, poly (α
-Methylstyrene) -polybutadiene-poly (α-methylstyrene) copolymer (α-MeS-B-α-Me)
S), poly (α-methylstyrene) -polyisoprene-
Poly (α-methylstyrene), butadiene-styrene copolymer (BS), ethylene-propylene-ethylidene copolymer, ethylene-vinyl acetate copolymer, ethylene-butene-1 copolymer, ethylene-propylene-ethylden Norbornene copolymer, ethylene-propylene-dicyclopentadiene copolymer, ethylene-propylene-1,
4 hexadiene copolymer, ethylene-butene-1-ethylidene norbornene copolymer, ethylene-butene-1-
Dicyclopentadiene copolymer, ethylene-butene-1
Resins or elastomers such as -1,4 hexadiene copolymer, acrylonitrile-chloroprene copolymer (NCR), styrene-chloroprene copolymer (SCR), calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, calcium sulfite, phosphoric acid Calcium, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, magnesium oxide, titanium oxide, iron oxide, zinc oxide, alumina, silica, diatomaceous earth, dolomite, gypsum,
Talc, clay, asbestos, mica, glass fiber, calcium silicate, bentonite, white carbon, carbon black, iron powder, aluminum powder, stone powder, blast furnace slag, fly ash, cement, filler such as zirconia powder, flame retardant, oxidation An anti-aging agent, an anti-aging agent, an ultraviolet absorber, an antistatic agent, a crystallization accelerator, a foaming agent, a coloring agent such as a dye or a pigment may be added.

[Blend of Polyester Resin with Thickening Agent and Polymerizing Agent] The blending method of the above components is preferably dry blending. Particularly, the mixture of the thickening agent and the polymerizing agent is pelletized to form a modifier. A molding material prepared by mixing a pulverized product of a polyester resin, particularly a flaky pulverized product with the modifier in the form of pellets, further mixing PC and / or AES, and pelletizing the mixture as it is or further. Is desirable.

[Hollow Profile Extrusion Molding] FIGS. 1 and 2 show an apparatus used for the hollow profile extrusion molding of the present invention. The above molding material is introduced into the cylinder (3) of the extruder (1) from the hopper (2) of the extruder (1),
It is heated and softened in (3) and extruded into a die (6) by a screw (5) which is driven and rotated by a motor (4). The softening material of the molding material is molded into a hollow irregular shape by the die (6) and introduced into the vacuum former (7).

In the vacuum former (7), as shown in FIG. 2, a cooling water passage (10) is provided between the outer cylinder (8) and the inner cylinder (9), and the cooling water passage (10) is further provided. ) To the cooling water inlet (1
1, 12) and cooling water discharge ports (13, 14) are provided, a vacuum suction port (15) connected to a vacuum pump is provided near the inlet, and the inner cylinder (9) has the vacuum suction port. A vacuum suction slit (16) communicating with the mouth (15) is provided.

The softening material M of the molding material molded in the hollow irregular shape by the die (6) is the inner cylinder of the vacuum former (7).
It is introduced into (9), exerts a vacuum suction force from the vacuum suction port (15) through the vacuum suction slit (16), is closely shaped on the inner peripheral wall of the inner cylinder (9), is shaped and is cooled and solidified. It On this occasion,
The above-mentioned modifier and PC and / or
Alternatively, since AES is added, the material does not easily clog the vacuum suction slit (16).

The softening material for the molding material is thus processed into a die.
After being molded into a hollow irregular shape by (6), it is shaped by a vacuum former (7), then introduced into a cooling water tank (17) and cooled to form a molded product M ′. Examples of the present invention will be described below.

[Example] A modifier 1 is prepared by mixing 20% by weight of epoxidized SBS (polymerizing agent) and 80% by weight of low-density polyethylene (thickener).

Polymerization agent 2 obtained by graft-copolymerizing styrene with an ethylene-glycidyl methacrylate copolymer 2
A modifier 2 is prepared by mixing 0% by weight and 80% by weight of a polymer alloy (thickener) of polypropylene and EPDM.

Waste PET bottles are pulverized and washed into flakes, and 85 parts by weight of the pulverized product (PET) and 15 parts by weight of the above-mentioned modifier 1 or modifier 2 are dry-blended, and the mixture is melt-kneaded and extruded by heating with an extruder. , A mixture of talc and PC or AES as shown in Table 1 in a recycled polyester resin pelletized by a pelletizer, or without mixing, hollow hollow extruded product samples shown in FIG. 3 by the apparatus shown in FIGS. 1 and 2. S was created. Each sample was examined for dimensional stability and whether or not the vacuum suction slit (16) of the vacuum former (7) was clogged. The results are shown in Table 2.
Shown in.

[0022]

[Table 1]

[0023]

[Table 2] Dimensional stability: It is judged that it is preferable that the portion a in FIG. 3 is closer to 8 mm.

From Table 2, it is clear that addition of PC or AES improves clogging as well as dimensional stability.

[0025]

According to the present invention, the clogging of the vacuum suction slit of the vacuum former in the case of hollow profile extrusion molding of polyester resin, particularly recycled polyester resin is eliminated, and the mass continuous molding process can be carried out without any trouble. I can. INDUSTRIAL APPLICABILITY The hollow profile extrusion-molded product of the present invention is useful, for example, as a trough having a quadrangular cross section, a slats having a horizontally long quadrangular cross section, a unit material for a bath, and the like.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention.

FIG. 1 is an explanatory view of a hollow profile extrusion molding device.

FIG. 2 is an explanatory sectional view of a vacuum former portion.

FIG. 3 is an explanatory cross-sectional view of a test sample.

[Explanation of symbols]

1 extruder 6 dies 7 Vacuum former 15 Vacuum suction port 16 Vacuum suction slit 17 Cooling water tank M molding material softening M'molded product

[Procedure amendment]

[Submission date] November 30, 2001 (2001.11.
30)

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

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Claims (5)

[Claims] 1. A polyester resin having a melt flow rate (MFR) of 20 g according to JIS K7210 Table 1, condition 4.
/ 10 minutes or less of a thickening agent, a polymerizing agent having a functional group capable of reacting with the polyester resin, and a polycarbonate and / or acrylonitrile-ethylene-styrene resin are added. Composition 2. The polyester resin composition according to claim 1, wherein the thickener and the polymerizing agent are mixed in advance and added to the polyester resin as a polyester resin modifier. 3. The thickening agent, the polymerizing agent and the polycarbonate and / or acrylonitrile / ethylene / styrene resin are premixed and added to the polyester resin as a polyester resin modifier.
The polyester resin composition described in 1. 4. The polyester resin composition according to claim 1, wherein the polyester resin is a regenerated polyester resin. 5. A hollow profile extrusion-molded product produced by profile-molding the polyester resin composition according to claim 1.