JP2011148960A - Polyester resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition excellent in elongation property, shock resistance and repeated bending property. <P>SOLUTION: The polyester resin composition contains 10 to 100 parts by mass of polyolefin, 5 to 50 parts by mass of a thermoplastic elastomer except for polyester-based and polyolefin-based elastomers, and 1 to 20 parts by mass of an ethylene-glycidyl methacrylate-styrene copolymer with respect to 100 parts by mass of polyester, wherein the 100 parts by mass of the polyester include 10 to 90 parts by mass of an amorphous glycol modified polyester. The polyester resin composition can be suitably used as a damping member. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyester resin composition, and more particularly to a polyester resin composition excellent in extensibility, impact resistance, and repeated flexibility.

  Polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyolefins such as high density polyethylene (HDPE) and low density polyethylene (LDPE), thermoplastic elastomers such as styrene-ethylene-butylene- Polyester-based resin compositions composed of styrene block copolymer (SEBS) and ethylene-glycidyl methacrylate-styrene copolymer have elongation, impact resistance, and repeated flexibility (mechanical durability). ) Is an excellent material.

  In addition to such a polyester resin composition, Patent Document 1 is an example of a technique for improving mechanical properties in a polyester resin composition. According to this, a PET resin product of used waste PET product is added to a polyolefin resin, a block copolymer of a specific vinyl aromatic compound and a conjugated diene compound, an epoxy group-containing olefin copolymer and a vinyl (co) polymer. It is shown that a regenerated PET resin composition exhibiting good mechanical properties can be obtained by blending the graft copolymer of the coalesce at a specific ratio and kneading at a temperature below the melting point of the PET pulverized product. Yes. Patent Document 1 also shows that the above effect can be obtained by using unused PET in addition to discarded PET.

JP 2003-213112 A

  However, since the conventional polyester resin composition uses a crystalline resin such as PET or PBT as a main component as a polyester resin, the conditions during the molding process, for example, the thickness of the molded body is thick, the molded body is large, As the thickness and size of the molded body increases, such as when the cooling rate during molding is slow, the crystallinity inside the molded body is promoted, and the required mechanical properties may not be obtained. Further, the recycled PET resin composition described in Patent Document 1 also has a similar problem because it uses a crystalline resin, and further has a temperature that is not lower than the melting point of the polyolefin resin and lower than the melting point of the PET pulverized product. In addition, there is a problem that it takes time and effort to knead the PET.

  Accordingly, an object of the present invention is to provide a polyester resin composition that solves the above problems and is excellent in extensibility, impact resistance, and repeated flexibility.

As a result of intensive studies to solve the above problems, the present inventors have obtained the following knowledge.
That is, the conventional polyester resin can obtain tensile elongation, impact resistance, and repetitive bending properties that cannot be obtained with individual single substances, but because it has a compounded composition containing polyester, As the sheath size increased, crystallization of polyester was promoted, and the above-mentioned problem occurred. Based on this knowledge, when a part of the polyester is replaced with an amorphous glycol-modified polyester, the crystallization of the polyester can be suppressed, and it does not depend on the thickness or size of the molded body, and is excellent in stretchability and impact resistance. The inventors have found that a polyester resin composition excellent in repeated flexibility can be obtained, and have completed the present invention.

That is, the polyester resin composition of the present invention comprises 10 to 100 parts by mass of polyolefin, 5 to 50 parts by mass of a thermoplastic elastomer other than polyester and polyolefin, and ethylene-glycidyl methacrylate with respect to 100 parts by mass of polyester. A polyester resin composition containing 1 to 20 parts by mass of a styrene copolymer,
In 100 parts by mass of the polyester, 10 to 90 parts by mass are amorphous glycol-modified polyester.

  In the present invention, the amorphous glycol-modified polyester is preferably amorphous glycol-modified polyethylene terephthalate, and more preferably cyclohexanedimethanol-modified polyethylene terephthalate. In the present invention, polyalkylene terephthalate can be suitably used as the polyester.

  The vibration damping member of the present invention is characterized by using the above polyester resin composition.

  According to the present invention, it is possible to provide a polyester resin composition excellent in extensibility, impact resistance, and repeated flexibility. In addition, it is possible to provide a vibration damping member that is excellent in extensibility, impact resistance, and repeatability.

Hereinafter, the polyester resin composition of the present invention will be described in detail.
Preferred examples of the polyester that can be used in the present invention include polyalkylene naphthalates such as polyethylene naphthalate (PEN) and polybutylene naphthalate (PBN), and polyalkylene terephthalates such as PET and PBT. . Particularly preferred is PET. In the present invention, two or more kinds of polyesters can be mixed and used.

  In the polyester resin composition of the present invention, it is important that 10 to 90 parts by mass of the polyester is 100% by mass of amorphous glycol-modified polyester. If the amorphous glycol-modified polyester in 100 parts by mass of the polyester is less than 10 parts by mass, the desired effect of the present invention cannot be obtained. On the other hand, when it exceeds 90 parts by mass, mechanical strength such as bending strength and elastic modulus of the obtained polyester resin composition is lowered. Preferably it is 30-60 mass parts.

The amorphous glycol-modified polyester that can be used in the present invention is preferably amorphous such as neopentyl glycol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, an alkylene oxide adduct of a bisphenol compound, and the like. Mention may be made of polyesters modified with functional glycols. In the present invention, amorphous glycol-modified PET (PETG) can be suitably used as the amorphous glycol-modified polyester, and cyclohexane dimethanol-modified PET is particularly preferred. Usually, PET is obtained by reaction of terephthalic acid (TPA) and ethylene glycol (EG), but PETG is obtained by replacing a certain content of EG with amorphous glycol such as cyclohexanedimethanol (CHDM). Amorphous glycol-modified polyester. Since addition of CHDM or the like can suppress crystallization, impact resistance and transparency can be improved. The following structural formula (I) is an estimated structural formula of CHDM-modified PET.

  The polyolefin that can be used in the present invention is preferably a homopolymer of an α-olefin such as ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-octene. And a copolymer thereof, a polyolefin modified with an unsaturated organic carboxylic acid or a derivative thereof, or a copolymer of these with other copolymerizable unsaturated monomers. Specific examples include polyethylene such as low density polyethylene (LDPE), medium density or high density polyethylene (HDPE), linear low density polyethylene (LLDPE), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer. Resin, polypropylene homopolymer, polypropylene modified with unsaturated organic carboxylic acid such as maleic acid or derivatives thereof, propylene-ethylene block copolymer, random copolymer, propylene-ethylene-butene-1 copolymer And polypropylene resins such as polybutene-1, polypentene-1, and poly-4-methylpentene-1. These may be used alone or in combination of two or more.

  In the present invention, among these, polyethylene resins such as HDPE and LLDPE can be preferably used. The polyethylene resin is not particularly limited, and those having a wide range of molecular weights can be used. From the viewpoint of the extrusion melt viscosity of the polyester resin composition of the present invention, the polyethylene resin is used at 190 ° C. and 21.2 N load specified by JIS-K7210. The melt flow rate (MFR) is preferably 0.01 to 10 g / 10 minutes, more preferably 0.01 to 5 g / 10 minutes. Further, pulverized products such as molded products of the above-mentioned polyethylene resin and molding waste, or repellets obtained by melt-kneading them can also be suitably used. Polyolefin is composed of ethylene-α-olefin copolymer rubber, ethylene-α-olefin-nonconjugated diene compound copolymer rubber (for example, EPDM), ethylene-aromatic monovinyl compound-conjugated diene compound copolymer, etc. Rubbers such as united rubber and hydrogenated products thereof may be included.

  In this invention, it is also important that polyolefin is 10-100 mass parts with respect to 100 mass parts of polyester. If the polyolefin content is less than 10 parts by mass with respect to 100 parts by mass of the polyester, the melt viscosity is low and the draw-down is easy, so that the extrusion moldability is impaired. On the other hand, when the amount is more than 100 parts by mass, mechanical strength such as bending strength and elastic modulus of the resulting polyester resin composition is lowered, which is not preferable. Preferably it is 10-35 mass parts.

  The thermoplastic elastomer that can be used in the present invention is preferably a polystyrene-based thermoplastic elastomer, a polydiene-based thermoplastic elastomer, a polyvinyl chloride-based thermoplastic elastomer, a chlorinated polyethylene-based thermoplastic elastomer, or a polyurethane-based thermoplastic elastomer. , Polyamide-based thermoplastic elastomers, fluororesin-based thermoplastic elastomers, and the like. These thermoplastic elastomers may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the present invention, the thermoplastic elastomer preferably has a block composed of a polymer of at least one vinyl aromatic compound and a block composed of a polymer of at least one conjugated diene, and more preferably a conjugated diene compound. It is a block copolymer in which at least a part of the polymer block is saturated by hydrogenation.

  As the vinyl aromatic compound which is a structural unit of the block copolymer, the aromatic part may be monocyclic or polycyclic, for example, styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 3-methylstyrene. , 4-propyl styrene, 4-cyclohexyl styrene, 4-dodecyl styrene, 2-ethyl-4-benzyl styrene, 4- (phenylbutyl) styrene, etc., among which styrene and / or α-methylstyrene is preferred.

  Examples of the conjugated diene compound that is a constituent unit of the block copolymer include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1 , 3-pentadiene, 1,3-hexadiene and the like, and among them, 1,3-butadiene, isoprene and combinations thereof are preferable. The microstructure in the block can be arbitrarily selected. For example, in the polybutadiene block, the 1,2-vinyl bond content is preferably 20 to 50% by mass, more preferably 25 to 40% by mass.

  The bond form of the vinyl aromatic compound polymer block and the conjugated diene compound polymer block in the block copolymer is not particularly limited, and is a straight chain, branched, radial, or a combination of two or more thereof. Any of the forms may be used, but among these, a linear bond form is preferable. Examples of block copolymers include X (YX) m, (XY) n or Y (XY) p when the vinyl aromatic compound polymer block is represented by X and the conjugated diene compound polymer block is represented by Y. (Where m, n, and p are integers of 1 or more), and a block copolymer having a bonding form. Among them, a block copolymer in which two or more vinyl aromatic compound polymer blocks X are linearly bonded to one or more conjugated diene compound polymer blocks Y, particularly XYX type It is preferable to use the triblock copolymer.

  In the block Y described above, saturation by hydrogenation of the residual unsaturated bond based on the conjugated diene compound is not particularly necessary, but from the viewpoint of thermal stability during heating and melting, heat resistance of the molded product, and prevention of deterioration of weather resistance. , At least a part of which is hydrogenated is preferable. Preferably, 50% or more, preferably 80% or more of the remaining unsaturated bonds are hydrogenated, and a polymer block mainly composed of a conjugated diene compound is morphologically converted to an olefinic compound polymer block. Can do. Specifically, for example, partially hydrogenated styrene-butadiene block copolymer, partially hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-isoprene block copolymer (SEP, styrene-ethylene-propylene block copolymer). Hydrogenated styrene-butadiene-styrene block copolymer (SEBS, styrene-ethylene-butylene-styrene block copolymer), hydrogenated styrene-isoprene-styrene block copolymer (SEPS, styrene-ethylene-propylene-styrene block copolymer) Among them, a linear XY-X-type block copolymer such as SEBS or SEPS is most preferable. Further, even if the residual unsaturated bond based on a vinyl aromatic compound or a conjugated diene compound is a block copolymer modified with a compound having a functional group such as a hydroxyl group, a carboxyl group, an epoxy group, an amino group or a derivative thereof. Good.

  In the block copolymer, the content of the structural unit derived from the vinyl aromatic compound is 10 to 60% by mass (the content of the structural unit derived from the conjugated diene is 90 to 40% by mass) with respect to all the structural units. It is preferably 15 to 40% by mass (85 to 60% by mass). If it deviates from this preferable range, the morphology of the polyester resin composition of the present invention may become unstable and impact resistance may be reduced.

  If the number average molecular weight of the block copolymer is too small, mechanical properties such as strength at break and extensibility of the block copolymer itself are lowered, and when the composition is used as a composition, the strength may be lowered. On the other hand, if the size is too large, the workability is deteriorated and a composition having sufficient performance may not be obtained. Therefore, the number average molecular weight is preferably in the range of 30,000 to 500,000, more preferably 50. , 000-300,000.

  As a production method of these block copolymers, any production method may be used as long as it has the above-mentioned structure, and one kind of the above block copolymer may be used alone. Moreover, you may use it in combination of 2 or more types.

  In the present invention, it is also important that the thermoplastic elastomer other than polyester and polyolefin is 5 to 50 parts by mass with respect to 100 parts by mass of polyester. The thermoplastic elastomer is a component necessary for imparting impact resistance to the polyester resin composition of the present invention, and is preferably 15 to 30 parts by mass. When the thermoplastic elastomer is less than 5 parts by mass, the resulting polyester resin composition has insufficient impact strength. On the other hand, if it exceeds 50 parts by mass, the resulting polyester resin composition will be softened and the mechanical strength and heat resistance will be reduced.

  Furthermore, in the polyester resin composition of the present invention, 1 to 20 parts by mass of ethylene-glycidyl methacrylate-styrene copolymer (EGMA-g-PS) may be contained with respect to 100 parts by mass of polyester. is important. The ethylene-glycidyl methacrylate-styrene copolymer is necessary for thickening the polyester, stabilizing the dispersion of the polyolefin in the polyester, and stabilizing the dispersion of the thermoplastic elastomer in the polyolefin. In order to obtain this effect satisfactorily, the content is preferably 5 to 15 parts by mass.

  In addition, the polyester resin composition of the present invention may have other conventional additives such as pigments, dyes, reinforcing materials (glass fibers, carbon fibers) at the time of polymer mixing depending on the purpose within a range not impairing the physical properties. , Talc, mica, clay mineral, potassium titanate fiber, etc.), filler (carbon black, silica, alumina, titanium oxide, metal powder, wood powder, rice husk, etc.), heat stabilizer, oxidative degradation inhibitor, UV absorber , Lubricants, mold release agents, crystal nucleating agents, plasticizers, flame retardants, antistatic agents, foaming agents, etc. can be blended, and the blending amount is generally used as long as the object of the present invention is not impaired. The amount can be.

  Examples of the method for producing the polyester resin composition of the present invention include a method using a kneader. The kneader is not particularly limited as long as the above components can be kneaded, and an extruder, a Banbury mixer, a roller, a kneader, or the like can be used. Examples of extruders include screw extruders such as single-screw extruders and twin-screw extruders, elastic extruders, hydrodynamic extruders, ram-type continuous extruders, roll-type extruders, gear-type extruders, etc. Among these, a screw extruder, particularly a twin screw extruder is preferable, and a twin screw extruder having one or more vents (deaeration ports) with high deaeration efficiency is more preferable.

  Although the use of the polyester resin composition of the present invention is not particularly limited, it can be suitably used as a vibration damping member because it is excellent in extensibility, impact resistance, and repeated bendability.

Hereinafter, the present invention will be described in more detail with reference to examples.
<Examples 1-9>
The polyester resin composition of the present invention was prepared according to the content of Table 1 below. As PET, TR-8550 manufactured by Teijin Chemicals Ltd., SKY GREEN J2003 manufactured by SK Chemical Co. as PETG, and HI-ZEX 1300J, HI-ZEX 232J, HI- manufactured by Prime Polymer Co., Ltd. as HDPE. ZEX 640UF was used as SEBS, SEPTON 8006 manufactured by Kuraray Co., Ltd., and EGMA-g-PS was manufactured by Nippon Oil & Fats Co., Ltd .: Modiper A4100. These materials were put into a kneading apparatus, melt-kneaded at 250 ° C. to 260 ° C. for 10 minutes, and a sample was obtained by injection molding. A twin screw extruder (Toyo Seiki Lab Plast Mill) was used as a kneading apparatus. The obtained samples were evaluated for elastic modulus, elongation at break, number of bending fatigue breaks and impact resistance according to the following procedures. The obtained results are also shown in Table 1 below.

<Comparative Examples 1-3>
Samples were prepared in the same manner as in Examples 1 to 9 except that PETG was not added, and the elastic modulus, elongation at break, number of bending fatigue breaks and impact resistance were evaluated. The obtained results are also shown in Table 1 below.

<Elastic modulus>
According to JIS K 7161-1994, it measured at the test temperature of 25 degreeC using the JIS dumbbell-shaped multipurpose test piece 1A type test piece (JIS K 7162).

<Elongation at break>
According to JIS K 7161-1994, it measured at the test temperature of 25 degreeC using the JIS dumbbell-shaped multipurpose test piece 1A type test piece (JIS K 7162).

<Number of times until bending fatigue fracture>
Using a JIS1A type dumbbell test piece, the test piece was folded 180 ° at the center in the longitudinal direction and folded in two, and then the bent part was inverted 360 ° and folded back into two. The above operation was repeated to determine the number of times until breakage.

<Impact resistance test>
In accordance with JIS K 7111, the JIS K 7139 multipurpose test piece 1A type was cut to produce a test piece. The test temperature was measured at 25 ° C.

※１：ＰＥＴ１００質量部中のＰＥＴＧの質量部数
※２：ＰＥＴ１００質量部に対する質量部数であり、ＨＤＰＥ欄中のＡ，ＢおよびＣはそれぞれ、ＨＩ−ＺＥＸ １３００Ｊ、ＨＩ−ＺＥＸ ２３２ＪおよびＨＩ−ＺＥＸ ６４０ＵＦを意味する。
※３：Ｎ．Ｂ．は未破断を意味する。

* 1: Number of parts by mass of PETG in 100 parts by mass of PET * 2: Number of parts by mass relative to 100 parts by mass of PET, A, B and C in the HDPE column are HI-ZEX 1300J, HI-ZEX 232J and HI-ZEX 640UF Means.
* 3: N.N. B. Means unbroken.

  From Table 1 above, it can be seen that the polyester resin composition of the present invention is excellent in extensibility, impact resistance and repeated flexibility.

Claims (5)

10-100 parts by mass of polyolefin, 5-50 parts by mass of a thermoplastic elastomer other than polyester and polyolefin, and 1-20 parts by mass of ethylene-glycidyl methacrylate-styrene copolymer with respect to 100 parts by mass of polyester. A polyester resin composition comprising:
10 to 90 parts by mass of amorphous polyester modified with 100 parts by mass of the polyester is a polyester resin composition.   The polyester resin composition according to claim 1, wherein the amorphous glycol-modified polyester is amorphous glycol-modified polyethylene terephthalate.   The polyester resin composition according to claim 2, wherein the amorphous glycol-modified polyester is cyclohexanedimethanol-modified polyethylene terephthalate.   The polyester resin composition according to claim 1, wherein the polyester is polyalkylene terephthalate.   A vibration damping member using the polyester resin composition according to any one of claims 1 to 4.