JP3291276B2 - Polyester polymer alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester polymer alloy having excellent impact resistance, and more particularly, to a high impact resistance and high rigidity applicable to recycled polyester resin and recycled polyolefin resin. The present invention relates to a polyester-based polymer alloy having the same.

[0002]

2. Description of the Related Art Polyethylene terephthalate resin (hereinafter referred to as PET resin) has been widely used in the field of drawing properties such as filaments, films, tapes and bottles because of its high drawing strength. On the other hand, PET
Although the resin has high rigidity, its glass transition temperature is as high as about 81 ° C., which makes it unsuitable for producing molded articles requiring impact resistance. At the time of use, it was mainly limited to use for small molded products.

Recently, the technology of recycling used PET bottles has been advanced, and recycled PET resin has been produced. However, the molecular weight of the PET resin has been reduced in the course of the recycling process, and the mechanical properties have been reduced accordingly. ing. Therefore, if the impact on the physical properties due to the decrease in molecular weight is compensated for, the high rigidity inherent in the PET resin is utilized, and if the impact resistance is further improved, injection molding of the PET resin including recycled products, It is expected that the range of application to the extrusion molding field will expand.

On the other hand, with respect to polyolefin resins, recovery of used polyolefin resins has been studied in many industrial fields including automobile parts, and even in such cases, physical properties similar to recycled PET resins have been reduced. Therefore, if a new utilization measure combining the recycled PET resin and the recycled polyolefin resin is considered, it can greatly contribute from the viewpoint of resource recycling.

[0005]

Accordingly, an object of the present invention is to provide a polymer alloy mainly composed of a polyester resin and having high impact resistance and high rigidity. Another object of the present invention is to provide a polymer alloy applicable to not only an unused resin but also a recycled PET resin or a recycled polyolefin resin.

[0006]

That is, the present invention provides a polyester resin (A) of 30 to 90% by weight, a carboxylic acid-modified ethylene / α-olefin copolymer (B) of 5 to 20% by weight, and a propylene-based polymer. (C) or density 0.9
Less than 20 (g / cm ³ ) ethylene polymer (D) 5
The present invention relates to a polyester-based polymer alloy formed of a resin composition comprising 50% by weight.

Here, the polyester resin is polyethylene terephthalate, the acid-modified ethylene / α-olefin copolymer is an α, β-unsaturated carboxylic acid graft-modified ethylene / α-olefin copolymer, and the propylene polymer is The propylene / ethylene block copolymer and ethylene-based polymer are preferably crystalline or amorphous ethylene / α-olefin copolymers. Such a resin composition has an Izo at −20 ° C.
d Impact strength (with notch) of 40 (J / m) or more is particularly preferable as a polymer alloy.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The polymer alloy according to the present invention is basically composed of a polyester resin, a carboxylic acid-modified ethylene / α-olefin copolymer, and a propylene polymer or an ethylene polymer. Next, the components and the polymer alloy will be described in detail.

Polyester resin (A) The polyester resin that can be used in the present invention is a polycondensate of an aromatic or aliphatic dicarboxylic acid and a diol. They may be selected and produced under ordinary polycondensation conditions, or may be produced by appropriately combining two or more kinds.

The dicarboxylic acids include terephthalic acid, isophthalic acid, adipic acid, sebacic acid, naphthalene-
Examples thereof include 1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, and diphenyl ether-4,4′-dicarboxylic acid.

As the diol, ethylene glycol,
Propylene glycol, 1,4-butylene glycol,
Neopentyl glycol, cyclohexanedimethanol, 2,2-bis (4-hydroxyphenyl) propane and the like can be exemplified. During the polycondensation, a hydroxycarboxylic acid such as p-hydroxybenzoic acid may coexist.

Typical examples of the polyester resin produced from the above dicarboxylic acid and diol include polyethylene terephthalate and polybutylene terephthalate. In addition, the polyester resin may be a recycled product after the molded product is used once, or may be a mixture of an unused product and a recycled product. These polyester resins have an intrinsic viscosity (IV) measured at 25 ° C. in a phenol / tetrachloroethylene = 50/50 (weight ratio) mixed solvent of 0.60 to 0.85 (dl /
g) is suitable for use.

Acid-modified ethylene / α-olefin copolymer
(B) The modified product that can be used in the present invention is an ethylene / α-olefin copolymer containing a carboxylic acid group, and specifically, an α / β-unsaturated carboxylic acid is added to the ethylene / α-olefin copolymer. Examples thereof include a polymer obtained by graft copolymerization of a compound, a polymer obtained by oxidizing an ethylene / α-olefin copolymer to form a carboxylic acid group in the copolymer molecule, and the like. The carboxylic acid-modified ethylene / α-olefin copolymer promotes uniform mixing of the polyester resin and the propylene-based polymer or the ethylene-based polymer, and contributes to the formation of a polymer alloy. In the present invention, the former graft-modified product is particularly suitable for forming a polymer alloy.

The ethylene / α-olefin copolymer has an ethylene content of 60 to 95, preferably 70 to 90.
(Mol%), α-olefin content of 5 to 40, preferably 1
0 to 30 (mol%) random copolymer. As the α-olefin, linear or branched C 3-20
Are preferred, for example, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-
Hexene, 1-octene and 1-decene can be mentioned, and two or more of them may be used in combination. Among these copolymers, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1
-Octene copolymers are preferred. In this copolymer,
A small amount of a diene component may be contained.

The ethylene / α-olefin copolymer has a density of 0.85 to 0.90 (g / c).
m ³ ), 230 ° C., according to ASTM D-1238.
2.Melt flow rate (M
FR) is 0.2 to 20 (g / 10 minutes), and X
It is desirable that the polymer is a low crystalline or amorphous polymer having a crystallinity of 25% or less as measured by a line diffraction method. Such an ethylene / α-olefin copolymer can be produced, for example, by performing copolymerization of ethylene and α-olefin in a solution state in the presence of a Ziegler catalyst or a metallocene catalyst.

As the α, β-unsaturated carboxylic acid to be used as the graft monomer, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, maleic anhydride, anhydride Examples thereof include itaconic acid, citraconic anhydride, and hymic acid anhydride, and acrylic acid, maleic acid, and maleic anhydride are particularly preferable.

The carboxylic acid-modified ethylene / α-olefin copolymer may be composed of only the above-mentioned graft-modified product, or may be a mixture of the graft-modified product and an unmodified ethylene / α-olefin copolymer. It may be.
The content of the α, β-unsaturated carboxylic acid in the graft-modified product or a mixture thereof is 0.01 to 5, preferably 0.05 to 0.05.
３3 (% by weight). When the content of the carboxylic acid is within the above range, the effect of increasing the compatibility between the polyester resin and the propylene-based or ethylene-based resin is high.

The graft copolymer of an α, β-unsaturated carboxylic acid onto an ethylene / α-olefin copolymer is prepared by subjecting the α / β-olefin copolymer to a solution or a melt of the above-mentioned α, β-olefin copolymer. It can be produced by subjecting a β-unsaturated carboxylic acid to a graft polymerization reaction.
At this time, if a radical generator such as a peroxide coexists, the grafting reaction can proceed efficiently.

Propylene polymer (C) Examples of the propylene polymer which can be used include propylene homopolymer, random copolymer of propylene and α-olefin, block copolymer of propylene and α-olefin, or Any of rubber-like copolymers of propylene and α-olefin may be used, and these may be unused polymers or regenerated polymers once used.

The α-olefin to be copolymerized with propylene is the same as that described above except for propylene, which has 2 to 20 carbon atoms.
Can be used. In the case of a random copolymer, the content of α-olefin unit is 0.5 to 5 mol%, and in the case of a block copolymer, the content of α-olefin unit is 0.5 to 5 mol%. It is desirable to contain 20 mol%.
Among these, preferred propylene-based polymers are propylene / ethylene random copolymer, propylene / 1-butene random copolymer, or propylene / ethylene block copolymer, and particularly when a block copolymer is used. High impact resistance improvement effect of polymer alloy.

The melt flow rate (MFR) is A
230 ° C, 2.16k in accordance with STM D-1238
The value measured under a g load is 0.1 to 50, preferably 0.5 to 20 (g / 10 minutes). When a propylene-based polymer in this range is used, the moldability of the polymer alloy is good and its mechanical strength can be increased. Such a propylene-based polymer is obtained by polymerizing propylene by using an olefin stereoregular polymerization catalyst such as a Ziegler-Natta-based catalyst or a metallocene-based catalyst, in the presence of an α-olefin, if necessary. Can be manufactured by

Ethylene Polymer (D) The ethylene polymer which can be used in the present invention belongs to a low density polymer among general ethylene polymers. Specifically, its density is less than 0.920, preferably 0.850
0.970, more preferably 0.870 to 0.910
(G / cm ³ ), and any polymer having an ethylene repeating unit as a main component, such as polyethylene, an ethylene / α-olefin copolymer, and a copolymer of ethylene and a vinyl monomer. Can also be used. When a polymer having a density of less than 0.920 (g / cm ³ ) is used as a component of the polymer alloy, a sufficient effect of improving impact resistance can be obtained. The ethylene-based polymer may be an unused polymer or a regenerated polymer.

As the polyethylene, either high-pressure low-density polyethylene or medium-low pressure low-density polyethylene can be used. In the latter case, the constituent unit usually contains 10 mol% or less of an α-olefin, and therefore partially overlaps with the ethylene / α-olefin copolymer described below.

As the ethylene / α-olefin copolymer, the low-crystalline or amorphous ethylene / α-olefin copolymer used as a raw material in producing the carboxylic acid-modified ethylene / α-olefin copolymer described above is used. In addition to the use of a polymer, an ethylene / α-olefin copolymer having crystallinity and physical properties close to polyethylene is also included. Therefore, the monomer composition of the ethylene / α-olefin copolymer has a wide range of 70 mol% or more of ethylene units and 30 mol% or less of α-olefin units. Here, the α-olefin can be appropriately selected and used from the above-mentioned olefins having 3 to 20 carbon atoms, and in particular, propylene, 1-butene, 1-hexene,
-Octene is preferred.

Examples of usable copolymers of ethylene and vinyl monomer include ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methyl methacrylate copolymer and the like.

As the ethylene-based polymer, the above-mentioned polyethylene or ethylene / α-olefin copolymer is preferable, and particularly, a crystalline ethylene / 1-hexene copolymer, an amorphous ethylene / propylene copolymer, a non-crystalline ethylene / propylene copolymer, Crystalline ethylene / 1-butene copolymer, amorphous ethylene / 1
-Octene copolymers are preferred. When an ethylene-based polymer is added as a component of the polymer alloy, the resin may become white and opaque, but a molded article having good appearance can be produced.

The ethylene / α-olefin copolymer belonging to the range from crystalline to amorphous belonging to the ethylene-based polymer is a Ziegler-based catalyst exemplified by a combination of a vanadium compound or a titanium compound with an organoaluminum compound, It can be produced by using an olefin stereoregular polymerization catalyst such as a metallocene-based catalyst as an example of a combination of a zirconium compound having a cyclopentadienyl ring and an oxyaluminum compound.

The melt flow rate (MFR) is A
Based on STM D-1238, 190 ° C, 2.16k
The value measured under a g load is 0.1 to 20, preferably 0.5 to 10 (g / 10 minutes). When it is within this range, the injection moldability and extrusion moldability of the polymer alloy are improved,
Mechanical strength can be increased.

The mixing ratio of the components constituting the resin composition the resin composition, polyester resin (A) 30 to 90, preferably 45 to 85 wt%, acid-modified ethylene · alpha-olefin copolymer (B) 5
-20, preferably 5-15% by weight, propylene-based polymer (C) or ethylene-based polymer (D) 5-50, preferably 5-40% by weight. Here, the total amount of the three components is 100% by weight. When each component is within this composition range, a molded article having excellent impact resistance and high rigidity can be obtained.

When the propylene polymer (C) is selected in this resin composition, the composition is 30 to 85, preferably 45 to 85% by weight of the polyester resin (A), and the carboxylic acid-modified ethylene α -5 to 20, preferably 5 to 15% by weight of the olefin copolymer (B), and 10 to 50, preferably 10 to 10% of the propylene-based polymer (C).
Desirably, it is in the range of 40% by weight.

When the ethylene polymer (D) is selected in this resin composition, the composition is preferably 60 to 90, preferably 65 to 85, the polyester resin (A).
%, A carboxylic acid-modified ethylene / α-olefin copolymer (B) 5 to 20, preferably 5 to 15% by weight, and an ethylene-based polymer (D) 5 to 30, preferably 5 to 2
It is desirably in the range of 0% by weight.

Various additives can be appropriately added to the resin composition without departing from the object of the present invention. Examples of additives include antioxidants, weather stabilizers,
Examples include an antistatic agent, a pigment, a nucleating agent, a flame retardant, and a filler.

Production of Polymer Alloy The polymer alloy according to the present invention was first dry-blended with the mixing ratio of each component constituting the resin composition using a Henschel mixer, V-blender, ribbon blender, tumbler blender or the like. After that, melt kneading is usually performed using a single screw extruder, a twin screw extruder, a kneader, a Banbury mixer, a mixing roll, or the like, whereby a high-quality alloy body having a uniform composition can be produced.

When mixing the polyester resin, it is desirable that the polyester resin be sufficiently dried beforehand in order to avoid hydrolysis. However, by applying a decompression operation through the vent port of the extruder, the physical properties are reduced. It is also possible to remove water up to the range of water absorption that does not cause water absorption.

Physical properties of polymer alloy This polymer alloy has a high impact strength at low temperatures, but must be used at a temperature of -20 ° C (notched) for use as an injection molded product or an extruded product.
Preferably has a value of 40 (J / m) or more. In addition, this polymer alloy uses a high-rate impact test (HighRate Impact Test), which is a test method without notching.
Test), that is, a test method in which a dart is penetrated through a flat square plate, also has high impact strength.

The polymer alloy preferably has a tensile elongation at break of 100% or more and a flexural modulus of 1100 MPa or more. The polymer alloy having such physical properties is a plastic material having high rigidity, and is suitable as a resin for industrial materials such as automobile interior / exterior parts, transportation goods such as pallets and containers.

[0037]

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

First, the materials used in the examples and comparative examples are as follows. (1) polyester resin: polyethylene terephthalate resin; intrinsic viscosity (IV) = 0.73 (dl / g) (2) carboxylic acid-modified ethylene / α-olefin copolymer: maleic acid graft-modified ethylene / propylene copolymer; Ethylene / propylene copolymer (ethylene content = 80 mol%, crystallinity by X-ray diffraction = 5%, MFR = 0.2
g / 10 min; 230 ° C.) by graft copolymerization of maleic anhydride (maleic acid content = 1.0% by weight).

(3) Ethylene polymer (A): ethylene / propylene copolymer; ethylene content = 80 mol%, density = 0.870 (g / c)
m ³ ), crystallinity by X-ray diffraction = 5%, MFR =
0.4 (g / 10 min) (4) Ethylene polymer (B): ethylene / 1-hexene copolymer; ethylene content = 94 mol%, density = 0.905 (g / c)
m ³ ), MFR = 4 (g / 10 min) (5) Ethylene polymer (C): ethylene / 1-hexene copolymer; ethylene content = 94 mol%, density = 0.920 (g / c)
m ³ ), MFR = 4 (g / 10 min)

(6) Ethylene-based polymer (D): ethylene / 4-methyl-1-pentene copolymer; ethylene content = 96.5 mol%, density = 0.920 (g)
/ Cm ³ ), MFR = 8 (g / 10 min) (7) Ethylene polymer (E): high-density polyethylene; ethylene content = 100 mol%, density = 0.968 (g /
cm ³ ), MFR = 5 (g / 10 min)

(8) Propylene polymer: propylene / ethylene block copolymer; propylene content = 93 mol%, density = 0.91 (g / c)
m ³ ), MFR = 5 (g / 10 min)

Each test was performed by the following method. (1) Izod impact test: Measured with a notch at −20 ° C. in accordance with ASTM D256. Unit: J / m (2) Tensile test: 23 according to ASTM D-638
Measured in ° C. Yield point strength unit: MPa, elongation at break unit:% (3) Bending test: 23 according to ASTM D-790
Measured in ° C. Unit of elastic modulus: MPa

(Examples 1 to 3) A polyester resin, a carboxylic acid-modified ethylene / α-olefin copolymer, and an ethylene polymer (A) or (B) were dry-blended at the ratios shown in Table 1, and then It is supplied to a directional rotary screw twin screw extruder (65 mmφ, L / D = 27, with two vents; PCM-65 manufactured by Ikegai Co., Ltd.), and the resin temperature is 265.
The mixture was kneaded at ℃ to obtain pellets.

The pellets were supplied to an 80-ton injection molding machine (Ti-80G2 manufactured by Toyo Machine Metal Co., Ltd.), and test pieces were prepared under the conditions of a cylinder temperature of 280 ° C. and a mold temperature of 30 ° C. An Izod impact test, a tensile test, and a bending test were performed using the test pieces, and the results are shown in Table 1.

(Comparative Examples 1 to 7) A polyester resin, a carboxylic acid-modified ethylene / α-olefin copolymer, and an ethylene-based polymer (C), (D) or (E) were mixed at the ratio shown in Table 1. Pelletizing was performed in the same manner as in Example 1, and thereafter, test pieces were manufactured by injection molding, and various physical property tests were performed. The measurement results are also shown in Table 1.

The overall evaluation in Table 1 was performed according to the following criteria.・: Izod impact strength of 40 (J / m) or more, elongation at break of 300% or more, and high flexural modulus. Δ ... Izod impact strength is 30 or more and 40 (J /
m) and the flexural modulus is high. X: When the Izod impact strength is less than 30 (J / m) or when granulation is impossible.

[0047]

[Table 1]

From the results shown in Table 1, it is shown that the combination of the three components of the polyester resin, the carboxylic acid-modified ethylene / α-olefin copolymer, and the ethylene polymer is indispensable for the constitution of the polymer alloy. . The ethylene polymer to be used is specified to be a polymer having a density of less than 0.920 (g / cm ³ ), so that the tensile strength and the flexural modulus of the polymer alloy can be maintained at a high level and the resistance can be maintained at a high level. The impact property can be improved.

(Examples 4 to 7) Pellets were obtained in the same manner as in Example 1 except that a propylene polymer was used in place of the ethylene polymer, and the composition of each component was changed at the ratio shown in Table 2. . The resin temperature in the extruder was 275 ° C. Test pieces were prepared from the pellets under the conditions of a cylinder temperature of 280 ° C. and a mold temperature of 30 ° C., and various tests were performed. The results are shown in Table 2.

(Comparative Examples 8 to 9) A polyester resin, a carboxylic acid-modified ethylene / α-olefin copolymer, and a propylene polymer were mixed in the proportions shown in Table 2, and pelletized in the same manner as in Example 4. Test pieces were manufactured by injection molding, and various physical property tests were performed. The measurement results are also shown in Table 2.

[0051]

[Table 2]

From the results shown in Table 2, this polymer alloy was
It is a resin with higher impact resistance than polyester resin, and has higher rigidity than polypropylene.
Further, even when the blending amounts of the polyester resin and the propylene-based resin are changed in a wide range, the polymer alloy can maintain a high level of impact strength, tensile strength and flexural modulus in a well-balanced manner.

[0053]

The polymer alloy according to the present invention has a high impact strength because it is a composition in which a polyester resin, an acid-modified ethylene / α-olefin copolymer and a propylene or ethylene polymer are uniformly mixed. And a molded article having high rigidity can be manufactured. Note that this impact strength shows a high value not only under the condition with notch but also under the condition without notch. This polymer alloy can be applied not only to unused polyester resins but also to recycled polyester resins.

Therefore, the polymer alloy having high mechanical strength is suitable for producing various injection molded products, extruded products, etc., and includes pallets, containers, containers, sheets,
It can be suitably used for industrial materials such as automobile interior and exterior parts.

The calorific value of the polyester resin, which is the main component of the polymer alloy, is about 1% of that of the polyolefin resin.
/ 2, and is hard to damage the incinerator when incinerating used molded products. Therefore, it is also suitable as a container for temporarily storing waste such as sanitary and medical tools before incineration. Can be used for

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Claims (16)

(57) [Claims] 1. A polyester resin (A) of 30 to 90% by weight, a carboxylic acid-modified ethylene / α-olefin copolymer (B) of 5 to 20% by weight, and a propylene-based polymer (C) or a density of 0.920 ( g / cm ³ ) of less than 5 to 50% by weight of the ethylene polymer (D) (where A, B,
Wherein the total amount of C or D is 100% by weight). 2. A method according to claim 1, wherein said resin composition comprises 30 to 85% by weight of a polyester resin (A) and carboxylic acid-modified ethylene / α.
-An olefin copolymer (B) 5 to 20% by weight, and a propylene-based polymer (C) 10 to 50% by weight (where
The polyester polymer alloy according to claim 1, wherein the total amount of A, B, and C is 100% by weight. 3. The resin composition according to claim 1, wherein the polyester resin (A) comprises 60 to 90% by weight of a carboxylic acid-modified ethylene / α.
5 to 20% by weight of an olefin copolymer (B) and 5 to 30% by weight of an ethylene-based polymer (D) (where A,
The polyester-based polymer alloy according to claim 1, wherein the total amount of B and D is 100% by weight. 4. The method according to claim 1, wherein said polyester resin (A) is polyethylene terephthalate.
4. The polyester-based polymer alloy according to any one of items 1 to 3. 5. The polyester-based polymer alloy according to claim 4, wherein said polyethylene terephthalate is a recycled resin. 6. The carboxylic acid-modified ethylene / α-olefin copolymer (B) is an α, β-unsaturated carboxylic acid graft-modified ethylene / α-olefin copolymer. 6. The polyester polymer alloy according to any one of 1 to 5. 7. The carboxylic acid-modified ethylene / α-olefin copolymer (B) contains 0.01 to 5% by weight of α, β-unsaturated carboxylic acid. 7. The polyester polymer alloy according to any one of 1 to 6. 8. The ethylene / α-olefin copolymer is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and has a crystallinity of 25% or less. The polyester-based polymer alloy according to any one of claims 1 to 7. 9. A copolymer wherein the ethylene / α-olefin copolymer is selected from the group consisting of ethylene / propylene copolymer, ethylene / 1-butene copolymer and ethylene / 1-octene copolymer. The polyester polymer alloy according to any one of claims 1 to 8, wherein 10. The polyester polymer alloy according to claim 1, wherein the propylene polymer (C) is a propylene / ethylene block copolymer. 11. The method according to claim 1, wherein the ethylene polymer (D) has a density of 0.850 to 0.915 (g / cm ³ ). Polyester polymer alloy. 12. The polyester according to claim 1, wherein the ethylene polymer (D) is a crystalline or amorphous ethylene / α-olefin copolymer. Based polymer alloy. 13. The polyester polymer alloy according to claim 1, wherein said ethylene polymer (D) is a crystalline ethylene / 1-hexene copolymer. 14. The ethylene polymer (D) is selected from the group consisting of amorphous ethylene / propylene copolymer, ethylene / 1-butene copolymer and ethylene / 1-octene copolymer. The polyester-based polymer alloy according to any one of claims 1 to 13, wherein the polyester-based polymer alloy is at least one copolymer. 15. The polyester polymer alloy according to claim 1, wherein the propylene polymer (C) or the ethylene polymer (D) is a recycled resin. 16. The polyester according to claim 1, which has an Izod impact strength (notched) at −20 ° C. of 40 (J / m) or more. Based polymer alloy.