JPH0116865B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a polyester resin composition, and particularly to a polyester resin composition that provides molded articles having extremely high impact resistance, appropriate flexural modulus, and excellent appearance and color tone. [Prior Art] A method of improving impact resistance by blending an ethylene-α olefin copolymer grafted with α,β-unsaturated carboxylic acid with polyester is known. [Problems to be Solved by the Invention] Industrial resins are required to have improved impact resistance compared to the conventional resins mentioned above. [Means for Solving the Problems] The structure of the present invention for solving the above problems is a thermoplastic polyester resin composition in which 100 parts by weight of polyester is blended with 1 to 120 parts by weight of a modified ethylene-α olefin copolymer. It is a thing. However, the above-mentioned modified ethylene-α olefin copolymer may contain an α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound of formula (), or this and an α,β-unsaturated carboxylic acid, its anhydride, or its ester. , grafted ethylene-α
It is an olefin copolymer. (Here, n represents an integer of 1 to 4, m represents an integer of 1 to 10, R ¹ and R ² represent a hydrogen atom or an alkyl group, and R ³ represents a hydrogen atom, an alkyl group, or a carboxyl group.) Below, To explain in detail, the thermoplastic polyester used in the present invention is a polyalkylene terephthalate obtained by a polycondensation reaction of terephthalic acid, isophthalic acid, or its dialkyl ester with fatty acid glycols, or a copolymer mainly composed of the polyalkylene terephthalate. Typical examples include polyethylene terephthalate and polybutylene terephthalate. The aliphatic glycols include ethylene glycol, 1,4-butadiol, ethylene glycol adduct of tetrabromobisphenol A,
Examples include propylene glycol, tetramethylene glycol, hexamethylene glycol, etc. Along with these aliphatic glycols, other diols or polyhydric alcohols, such as cyclohexanediol, cyclohexanediol, etc. Methanol, xylene glycol, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromphenyl)propane, 2,
A mixture of 2-bis(4-hydroxyethoxyphenyl)propane, 2,2-bis(4-hydroxyethoxy-3,5-dibromphenyl)propane, glycerin, pentaerythritol, etc. may be used. In addition, based on terephthalic acid or its dialkyl ester, other dibasic acids, polybasic acids or their alkyl esters, such as phthalic acid, isophthalic acid, naphthalene dicarboxylic acid, in an amount of not more than 30% by weight based on terephthalic acid or its dialkyl ester. , diphenyldicarboxylic acid, adipic acid, sebacic acid, trimesic acid, trimellitic acid, alkyl esters thereof, etc. may be used in combination. Modified ethylene-α-olefin copolymer is a copolymer of ethylene and α-olefin having 3 or more carbon atoms (hereinafter referred to as unmodified ethylene-α-olefin copolymer), and α, β- An unsaturated carboxylic acid group-containing tetrahydrofuran compound or the α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound and an α,β-unsaturated carboxylic acid, its anhydride, or its ester to an unmodified ethylene-α-olefin copolymer. It was obtained by grafting. The unmodified ethylene-α-olefin copolymer, which is a raw material for the above-mentioned modified ethylene-α-olefin copolymer, contains, for example, vanadium compounds such as vanadium oxytrichloride and vanadium tetrachloride and organic aluminum compounds among Ziegler-Natsuta catalysts. 50 mol% or more of ethylene, preferably 80 to 95
Examples include copolymerization of α-olefin having 3 or more carbon atoms in an amount of 50 mol% or less, preferably 20 to 5 mol%. Examples of α-olefins having 3 or more carbon atoms include propylene, 1-butene, 1-hexane, and 1-decene.
Examples include 1,4-methylbutene-1,4-methylpentene-1, and propylene or butene-1 is preferred. Suitable unmodified ethylene-α-olefin copolymers include a series of resins commercially available from Mitsui Petrochemical Industries, Ltd. under the trademark Tafmer, such as Tafmer A4085, A4090, A20090,
Tafmer A series (ethylene-butene-
1 copolymer), Tafmer P0280, P0480, P0680,
Examples include Tafmer P series (ethylene-propylene copolymer) such as P0880. The α,β-unsaturated carboxylic acid of the α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound of formula () to be grafted onto this is acrylic acid,
Methacrylic acid, ethacrylic acid, maleic acid, and fumaric acid can be mentioned, and among these, acrylic acid or methacrylic acid is preferred. n is 1
An integer of ˜4, preferably 1-2. m is 1~
An integer of 10, preferably 2-6. The grafting amount of α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound is unmodified ethylene-α
The amount is 0.01 to 2.0% by weight, preferably 0.02 to 1.8% by weight, based on the olefin copolymer. If the amount is too small, there will be no effect, and if it is too large, it will become a source of gas generation.
Silver appears on the surface. Furthermore, in some cases, an α,β-unsaturated carboxylic acid, an anhydride thereof, or an ester thereof to be grafted onto the unmodified ethylene-α olefin copolymer together with the α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound of formula (). can include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, or anhydrides or esters of these acids. Among these, maleic anhydride is particularly preferred. The amount of α,β-unsaturated carboxylic acid or its anhydride or its ester to be grafted onto the unmodified ethylene-α-olefin copolymer is 0.05 to 5% by weight based on the unmodified ethylene-α-olefin copolymer.
It is. In addition to the α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound, when α,β-unsaturated carboxylic acid, its anhydride, or its ester is used in combination, IZOD impact value, tensile elongation, etc. The physical properties of are improved. However, if the amount is too large, it may cause coloring when added to the polyester resin, which is not preferable. preferably 0.07
-3% by weight. The grafting reaction is carried out by adding an α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound to the ethylene-α-olefin copolymer or this and α,
A β-unsaturated carboxylic acid, its anhydride, or its ester is added and melt-kneaded, usually at 150 to 300°C. The method for grafting two types of compounds may be a sequential method in which one is first grafted and then the other is grafted. A screw type extruder is often used for this melt-kneading. Of course, in order to efficiently cause the grafting reaction, α,α′-bis-t-butylperoxy-p
- An organic peroxide such as diisopropylbenzene may be used in an amount of about 0.001 to 0.05% by weight based on the unmodified ethylene-α-olefin copolymer. The modified ethylene-α-olefin copolymer used in the present invention has a crystallinity (measured by X-ray method according to the description in Journal of Polymer Science, Vol. 1955, pages 17 to 26) of 75% or less, It is preferably 1 to 35%, and the melt index (MI, 190% according to ASTM D1238 57T)
(measured at °C, unit g/10 min) is preferably from 0.01 to 50, preferably from 0.02 to 30. To prepare a modified ethylene-α-olefin copolymer with such a crystallinity and melt index, an unmodified ethylene-α-olefin copolymer having a crystallinity and melt index within the above range is used. do it. The above-mentioned additives can be blended into the polyester at any stage up to just before molding the final molded product by various means. The simplest method is to dry blend the polyester and additives, but this dry blend may also be melt-mixed and extruded to form pellets. Also,
A master pellet containing a predetermined amount or more of the additive may be prepared, and this may be blended with polyester pellets for dilution. To obtain the final molded product, the blend or pellets described above may be fed to various types of machines such as injection, extrusion, blowing, and compression, and molded according to conventional methods. Addition of substances can also be carried out in a molding machine. The blending amount of the modified ethylene-α-olefin copolymer is 1 to 120 parts by weight per 100 parts by weight of the polyester. If it is less than 1 part by weight, the improvement effect will not be sufficient, and if it exceeds 120 parts by weight, heat resistance will deteriorate. Preferably it is 5 to 100 parts by weight. The compositions of the present invention also include reinforcing agents such as glass fibers and carbon fibers, clay, silica, alumina,
fillers such as silica alumina, glass beads, asbestos, graphite, plaster, dyes/pigments, stabilizers,
Well-known additives such as antistatic agents may be used in combination. [Example] Hereinafter, the present invention will be specifically explained with reference to Examples. In addition, the amounts of ingredients in the examples "%" and "parts"
are all based on weight. [Production of modified ethylene-α-olefin copolymer] Example 1

[Table] After blending the raw materials with the above composition, they were extruded into pellets at 200°C using a 30φ twin-screw extruder (manufactured by Nakatani Kikai). The crystallinity of the resulting ethylene-butene-1 copolymer grafted with a tetrahydrofuran compound containing an α,β-unsaturated carboxylic acid group was 20% and an MI of 2.0. After pulverizing a portion of this pellet and extracting unreacted materials with acetone, the amount of the grafted α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound was determined by IR method to be 0.5% of the ethylene-butene-1 copolymer. It was in weight%. Example 2 Tetrahydrofurfuryl methacrylate grafted ethylene-butene in the same manner as in Example 1 except that 1 part of the α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound was replaced with 1 part of tetrahydrofurfuryl methacrylate. 1 copolymer was obtained. The amount of grafted tetrahydrofurfuryl methacrylate was 0.2% by weight, the crystallinity was 20%, and the MI was 1.9. Example 3 A maleic anhydride grafted ethylene-butene-1 copolymer was obtained in the same manner as in Example 2 except that 1 part of tetrahydrofurfuryl methacrylate was replaced with 0.5 part of maleic anhydride. (The amount of grafted maleic anhydride is 0.4%, the crystallinity is 20%,
It was MI1.9. ) This maleic anhydride grafted ethylene-butene-1 copolymer 100 parts α,α'-bis-t-butylperoxy-p-diisopropylbenzene (dissolved in a small amount of acetone) 0.05 part Same as used in Example 1 1 part of α,β unsaturated group-containing tetrahydrofuran compound The raw material having this composition was extruded and pelletized in the same manner as in Example 1. Ethylene grafted with these two types of functional groups.
The crystallinity of the butene-1 copolymer is 20%, MI1.8,
Maleic anhydride amount: 0.37%, α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound amount: 0.48%
(Respectively for ethylene-butene-1 copolymer)
It was hot. Examples 1 to 2 and comparative examples Polybutylene terephthalate ([η] = 1.1) 100
After blending 20 parts of various modified ethylene-α olefin copolymers shown in Table 1 below, the resin temperature was adjusted using a 3.6-ounce injection molding machine (Toshiba Machine IS75PN).
Test pieces for measuring physical properties were made at 260℃ and mold temperature of 80℃. The physical properties of the test piece were as shown in Table 2.

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【table】

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〔Effect of the invention〕

As explained above, although the polyester resin composition of the present invention has significantly improved impact resistance and tensile elongation compared to conventional resins, other mechanical properties are equivalent to or slightly improved compared to conventional resins. It has the excellent property of being

Claims (1)

[Scope of Claims] 1 100 parts by weight of polyester and 0.01 to 2.0% by weight of an α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound represented by the following formula () are grafted to the ethylene-α-olefin copolymer. A polyester resin composition comprising 1 to 120 parts by weight of a modified ethylene-α-olefin copolymer. (Here, n represents an integer of 1 to 4, m represents an integer of 1 to 10. ^{R 1} and R ² are hydrogen atoms or alkyl groups,
R ³ represents a hydrogen atom, an alkyl group or a carboxylic acid group. ) 2 100 parts by weight of polyester, 0.01 to 2.0% by weight of an α,β-unsaturated carboxylic acid group-containing tetrahydrofuran compound represented by the following formula () based on the ethylene-α-olefin copolymer, and α,β-unsaturated A polyester resin composition comprising 1 to 120 parts by weight of a modified ethylene-α-olefin copolymer grafted with 0.05 to 5% by weight of a carboxylic acid, its anhydride, or its ester. (Here, n represents an integer of 1 to 4, m represents an integer of 1 to 10. ^{R 1} and R ² are hydrogen atoms or alkyl groups,
R ³ represents a hydrogen atom, an alkyl group or a carboxylic acid group. )