JPS6353225B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic polyester resin composition with improved mechanical properties including impact resistance and heat resistance. Thermoplastic polyester, especially polybutylene terephthalate (hereinafter abbreviated as PBT), has well-balanced physical properties and excellent moldability, and is widely used in mechanical parts, electronic/electrical parts, automobile parts, and other fields. It's being used. However, although PBT has excellent properties, it also has the major drawback of low notch impact strength.
In other words, PBT shows good impact strength without a notch, but when a notch is added, the impact strength decreases significantly, and in practical terms, consideration must be given to eliminating sharp edges in molded product design. However, this means that the molded product is scratched and is more likely to be damaged if an impact is applied to it, which is an obstacle to expanding its use. In the past, various methods have been studied to improve the notched impact strength of PBT. 51-25261), a method of blending polyether ester block copolymers (Japanese Patent Application Laid-open No. 1983
-48059), a method of blending an acrylic multiphase composite copolymer (JP-A-52-150466), a method of blending an α,β-unsaturated carboxylic acid graft-modified ethylene copolymer (JP-A-55- 21430), but the impact resistance improvement effect is insufficient, or while the impact resistance has been improved, mechanical properties such as tensile strength and bending strength, heat resistance stability,
Other useful properties such as weather resistance and moldability are significantly reduced, and the balance of the excellent properties of PBT is lost, resulting in unsatisfactory results. In particular, regarding the behavior during heating and melting, the melt stability during heating is poor and the change in melt viscosity is large, so if it stays in the molding machine for a slightly longer period of time, fluidity may decrease in some cases, resulting in shortening. In severe cases, molding defects such as gelation may occur, and in some cases, resin decomposition is accelerated and fluidity increases, resulting in molding defects such as increased burrs from the mold. In some cases, it was even observed that the impact resistance of the molded product decreased and it became brittle. The present inventors have previously developed a thermoplastic polyester composition with excellent impact resistance and thermal melt stability, containing 0.01 to 10% by weight of an unsaturated carboxylic acid (anhydride).
Ethylene graft-polymerized with α of 3 to 6 carbon atoms
- We proposed a thermoplastic polyester resin composition made by blending and melt-mixing a copolymer with olefin and a polyepoxy compound containing two or more epoxy groups. When performing a peel test by attaching cellophane tape to a molded product and peeling it off vigorously, it was observed that some of the resin on the surface of the molded product peeled off, so we decided to further improve the peel resistance. As a result of extensive research, we have arrived at the present invention. That is, the present invention provides (A) thermoplastic polyester resin
Copolymer of ethylene and α-olefin having 3 to 6 carbon atoms graft-polymerized with 95 to 50 parts by weight and 0.01 to 10% by weight of (B) an unsaturated carboxylic acid or its anhydride 5
~50 parts by weight, (C) 2 to 50 parts by weight of polyamide resin, and
(D) A thermoplastic polyester resin composition consisting of a polyepoxy compound, which is obtained by adding 0.1 to 10 parts by weight of (A) to a total of 100 parts by weight of (A), (B), and (C) and melt-mixing them. It provides: Here, the thermoplastic polyester resin
(A) means terephthalic acid or its esters;
Ethylene glycol, prolene glycol, butadiol, pentanediol, neopentyl glycol, hexanediol, octanediol,
Decanediol, cyclohexanedimethanol,
It is a polyester obtained from glycols such as hydroquinone, bisphenol A, 2,2-bis(4-hydroxyethoxyphenyl)propane, 1,4-dimethyloltetrabromobenzene, or TBA-EO, and is usually has an intrinsic viscosity [η] measured at 30°C in a mixed solvent of phenol and tetrachloroethane in a weight ratio of 6:4.
A range of 0.3 to 1.5 dl/g is used. In addition, less than 40 mol% of the total acid components are composed of isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, diphenyl ether dicarboxylic acid, α,β-bis(4-
carboxyphenoxy)ethane, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid,
other dicarboxylic acids such as cyclohexanedicarboxylic acid or dimer acid, or glycolic acid,
Hydroxycarboxylic acids such as hydroxybutyric acid, hydroxycaproic acid, hydroxybenzoic acid, hydroxyphenyl acetic acid or naphthyl glycolic acid may be substituted, while up to 40 mol% of the total glycol component may be replaced by polyethylene glycol or polytetramethylene. It may be replaced with polyalkylene ether glycols such as ether glycol or aliphatic polyester oligomers having hydroxyl groups at both ends. In addition, a lactone compound such as propiolactone, butyrolactone, valerolactone, or caprolactone or a polymer thereof may be contained as a comonomer component in an amount of 40 mol% or less in the total monomer component, or within a range that can maintain thermoplasticity. It may also contain polyfunctional ester-forming components such as trimethylolpropane, trimethylolethane, glycerin, pentaerythritol; trimellitic acid, trimesic acid, pyromellitic acid, and the like. Also, low molecular weight polyalkylene terephthalate with a hydroxyl group at the end ([η] = 0.1 to 0.5 dl/g)
Also included in the present invention are polyester polyurethanes obtained by increasing the molecular weight with polyfunctional isocyanates. Among these thermoplastic polyesters, especially
Desired effects are exhibited in PBT and polyethylene terephthalate. Component (B) used in the present invention is used as an impact modifier (hereinafter referred to as unsaturated acid grafted ethylene copolymer), and contains 0.01 to 10% by weight of unsaturated carboxylic acid or its anhydride. It is a copolymer of graft-polymerized ethylene and α-olefin having 3 to 6 carbon atoms. Copolymers of ethylene and 3 to 6 carbon atoms (hereinafter simply referred to as ethylene copolymers) used as the backbone polymer include propylene, butene-1, isobutene-1, pentene-1,
A copolymer with an α-olefin having 3 to 6 carbon atoms such as 4-methylpentene-1 or hexene-1, or a copolymer with one or more other copolymerizable monomers. Ethylene/propylene copolymer, ethylene/butene-1 copolymer,
Ethylene/4-methylpentene-1 copolymer, ethylene/hexene-1 copolymer, ethylene/propylene/butene-1 copolymer, ethylene/propylene/4-methylpentene-1 copolymer, ethylene/propylene /hexene-1 copolymer, ethylene/propylene/ethylidene norbornene copolymer, ethylene/propylene/dicyclopentadiene copolymer, ethylene/butene-1/ethylidene norbornene copolymer, ethylene/butene-1
Examples include 1/dicyclopentadiene copolymer. In addition, examples of unsaturated carboxylic acids or anhydrides thereof to be graft-polymerized to these ethylene copolymers include maleic acid, fumaric acid, itaconic acid, methylmaleic acid, and 3,6-endomethylene-delta-4-tetrahydrophthal. Acid, acrylic acid, methacrylic acid, crotonic acid, citraconic acid, maleic anhydride, itaconic anhydride, methylmaleic anhydride, 3,6-endomethylene-delta-4-tetrahydrophthalic anhydride, 2-methyl-3, 6-
Endomethylene-delta-4-tetrahydrophthalic anhydride, 3-methyl-4-cyclohexene-
Examples include 1,2-dicarboxylic acid anhydride. Further, derivatives of these acids such as esters, amides, imides, and nitriles may be used together with these unsaturated carboxylic acids or their anhydrides. The polymerization reaction of grafting an unsaturated carboxylic acid or its anhydride onto the main ethylene copolymer can be carried out in a molten state, a suspended state, a slurry state, or a molten state by known means. For example, unsaturated carboxylic acid (anhydride) and organic peroxide are added to a solution of an ethylene copolymer dissolved in a solvent such as toluene or hexane, and graft polymerization is carried out under heating and stirring, followed by removal of the solvent or removal of the nonsolvent. Alternatively, a mixture of the ethylene copolymer, unsaturated carboxylic acid (anhydride), and organic peroxide is heated and melt-kneaded using an extruder, kneader, etc. A method of performing graft polymerization is used below. The amount of unsaturated carboxylic acid or its anhydride to be graft-polymerized is 0.01 to ethylene copolymer.
~10% by weight, preferably 0.1 to 7% by weight. If this amount is less than 0.01% by weight, the effect of improving the impact on the thermoplastic polyester will be small, and if it is too large, the thermoplastic polyester resin composition may be colored. , the change in melt viscosity in the molten state becomes large, which is undesirable. The amount of the unsaturated acid-grafted ethylene copolymer (B) is 5 to 50 parts by weight, preferably 10 to 50 parts by weight, based on the total of 100 parts by weight of the thermoplastic polyester resin (A), polyamide resin (C), and (B). If it is less than 5 parts by weight, there is almost no effect of improving impact resistance, while if it is more than 50 parts by weight, the excellent properties of the thermoplastic polyester resin will not be exhibited, and it is no longer the object of the present invention. It cannot be called an engineering plastic. Resin containing amide group used in the present invention (C)
are obtained by ring-opening lactam polymers, polycondensates of diamines and dibasic acids, self-polycondensates of ω-amino acids, or copolymerization thereof, and specifically include polycapramide, polyundecamide, polylauramide, and hexamethylene adipamide,
All known polyamide resins include polyhexamethylene sebaamide, polyhexamethylene lauramide, polyxylylene adipamide, polyamides made of terephthalic acid and/or isophthalic acid and trimethylhexamethylene diamine or xylylene diamine, or copolymers thereof. It will be done. In addition, the polyamide resin used in the present invention includes
Contains linking groups such as ester groups, ether groups, urethane groups, imide groups, urea groups, carbonate groups, ketone groups, acid anhydride groups, and sulfone groups in addition to amide groups, and is suitable for random copolymerization, block copolymerization, and grafting with amide components. They may be copolymerized or reticulated to the extent that thermoplasticity is not lost, and include polyetheramide, polyesteramide, polyamideimide, ionomer-modified polyamide, methoxymethylated polyamide, and the like. The blending amount of the polyamide resin (C) is 2 to 50 parts by weight, preferably 5 parts by weight, based on the total of 100 parts by weight of the thermoplastic polyester resin (A), the unsaturated acid-grafted ethylene copolymer (B), and the component (C). ~50 parts by weight, and if it is less than 2 parts by weight, there is almost no effect of improving peeling resistance;
If it exceeds 50 parts by weight, the excellent properties of the thermoplastic polyester resin will not be exhibited, which is undesirable. In addition, the blending amount of thermoplastic polyester resin (A) is (A)
95 to 50 parts by weight out of a total of 100 parts by weight of (B) and (C). Polyepoxy compound containing two or more epoxy groups added as an essential component in the present invention
(D) increases the melt stability of this composition and has a synergistic effect on improving mechanical strength including impact resistance and bending strength, and suitable polyepoxy compounds include bisphenol. A diglycidyl ether, nidroquinone diglycidyl ether, resorcinol diglycidyl ether,
4,4'-biphenyl diglycidyl ether, 4,
4′-diphenylsulfone diglycidyl ether,
Triglycidyl ether of trihydroxyphenylpropane, tetraglycidyl ether of tetrahydroxyphenylethane, polyglycidyl ether of Novolak, diethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, cyclooctadiene-(1, 5)-diepoxide, dicyclopentadiene diepoxide, bicycloheptadiene diepoxide, 1,2,5,
Examples include 6-diepoxycyclododecane-9 and epoxidized soybean oil. Also included are oligomeric polyepoxy compounds obtained by addition polymerizing the above polyepoxy compounds and polyphenols or polyols. The amount of polyepoxy compound (D) is the same as resin components (A) and (B).
and (C) in an amount of 0.1 to 10 parts by weight, preferably 1 to 8 parts by weight, and if it is less than 0.1 part by weight, there is almost no improvement effect; No improvement in the improvement effect is observed, and on the contrary, mechanical properties and melt fluidity may deteriorate, which is not preferable. The composition of the present invention includes glass fibers, potassium titanate fibers, metal fibers, ceramic fibers; calcium carbonate, calcium silicate, magnesium silicate,
Calcium sulfate, barium sulfate, iron oxide, graphite,
Including reinforcing fillers such as carbon black, mica, asbestos, ceramics, metal frames, glass beads or glass powder, crystal nucleating agents, pigments, dyes, plasticizers, mold release agents, lubricants, heat stabilizers, and antioxidants. A UV absorber, a blowing agent, a flame retardant, a coupling agent, etc. may be used in combination. Thus, the composition of the present invention can be prepared, for example, by uniformly mixing all the above-mentioned components in advance, and then supplying the mixture to a single-screw or multi-screw extruder.
Melted at 300℃, kneaded, then cooled,
Prepared as pellets. The thermoplastic polyester resin composition of the present invention has significantly improved notched impact strength, stable melt viscosity, excellent moldability, and increased peeling resistance on the surface of molded products.
In addition, due to its well-balanced physical properties, it is extremely useful industrially, and in addition to traditional uses such as electrical and electronic parts, mechanical parts, automobile parts, and building material parts, it can also be used as tool storage boxes, power tool jackets, Fields that require high toughness such as sporting goods, bearings, and Kia, large molded products such as office machine housings and automobile bumpers, and equipment used in cold regions.
It can also be used in fields such as textiles, films, and adhesives. Next, the present invention will be specifically explained using Reference Examples, Examples, and Comparative Examples. In the following, "parts" and "%" are used unless otherwise specified. All “weight parts”
and "% by weight" shall be meant. Reference Example 1 Ethylene-butene-1 copolymer (manufactured by Mitsui Petrochemical Industries, Ltd., trade name Tafmer A-4085) 100 parts, 1,
3-bis(t-butylperoxyisopropyl)
After mixing 0.1 part of benzene (manufactured by Kayaku Nury Co., Ltd., trade name Percadox 14-40) and 0.5 part of maleic anhydride in a Henschel mixer, a screw with a diameter of 50
mmφ, 230℃ using a fully intermeshing type twin screw extruder
The mixture was melt-polymerized and pelletized to obtain a maleic anhydride-grafted ethylene/butene-1 copolymer (a). A portion of this pellet was pulverized, and unreacted maleic anhydride was extracted with acetone using a Soxhlet extractor. The copolymer from which unreacted substances were removed was dissolved in cyclohexane, and the acid value was measured by titration with a 1/10N alcoholic KOH solution.The acid value was 5.2.
It was found that 0.45% maleic anhydride was grafted in terms of maleic anhydride. Reference Example 2 100 parts of ethylene-butene-1 copolymer (trade name: TAFMER A-4085) was dissolved in 400 parts of toluene at 80° C. with stirring, and then 5 parts of maleic anhydride was added and dissolved. Next, after raising the temperature of the contents to 110°C,
Tertiary butyl peroxybenzoate (NOF
A solution of 0.15 parts of Perbutyl Z (manufactured by Co., Ltd.)/20 parts of toluene was added dropwise over 1 hour, and polymerization was carried out at 110°C for 10 hours. After diluting the obtained graft polymer solution with toluene to a concentration of 5%, the same amount or more was heated at 45-55℃.
Graft polymer (b) was precipitated by adding it little by little to methanol, followed by washing and drying. Acid value measurement revealed that 4.7% maleic anhydride was grafted. Example 1 75 parts of PBT with intrinsic viscosity [η] 1.0, 15 parts of maleic anhydride-grafted ethylene-butene-1 copolymer (a) obtained in Reference Example 1, trade name Grilon ELY-60
(manufactured by EMS-Chemie, polyether polyamide elastomer) 10 parts, trade name Epiclon 3050 (manufactured by Dainippon Ink & Chemicals Co., Ltd., bisphenol A type diepoxy compound) 2 parts, and trade name Irganox 1010 (manufactured by Ciba-Geigy) After uniformly mixing 0.2 parts of antioxidant) in advance, this mixture was passed through a 40mmφ single-screw extruder equipped with a Dalmage type screw.
The mixture was kneaded at 240°C, cooled and shredded to obtain resin pellets. Next, using an injection molding machine, a test piece for measuring physical properties was formed from this pellet, and the notched Izo impact strength (test piece thickness: 3 mm) at room temperature (23°C) and -40°C was determined according to ASTMD-256. ASTMD
-7900, bending strength and bending strength ratio were measured. In the peel test, a cellophane tape with a width of 18 mm and a length of 3 cm was firmly pasted on the surface of the injection molded sheet, and after being vigorously peeled off, the adhesive surface of the cellophane tape was observed. If the resin adhered to the adhesive surface,
If it did not adhere, it was judged as 〇. The results are summarized in Table 1. Comparative Example 1 A composition was prepared in the same manner as in Example 1 except that the diepoxy compound was removed, molded, and evaluated. The composition of Comparative Example 1 had lower impact resistance and bending strength than the composition of Example 1. The results are shown in Table 1. Comparative Example 2 The same composition as in Example 1 was prepared except that the maleic anhydride grafted ethylene/butene-1 copolymer (a) was removed and the amount of the brand name Grilon ELY-60 was increased to 25 parts. It was prepared, molded, and evaluated. The composition of Comparative Example 2 had significantly lower impact resistance than the composition of Example 1. The results are shown in Table 1. Comparative Example 3 In the formulation of Example 1, the brand name Grillon
The same composition was prepared, molded, and evaluated in the same manner except that ELY-60 was removed and the maleic anhydride grafted ethylene/butene-1 copolymer (a) was increased to 25 parts. Although the composition of Comparative Example 3 was comparable to Example 1 in terms of physical properties, a portion of the resin adhered to the cellophane tape side in a peel test, and its peel resistance was poor. The results are shown in Table 1. Example 2 70 parts of PBT with an inherent viscosity [η] of 1.0, 20 parts of the maleic anhydride-grafted ethylene-butene-1 copolymer (a) obtained in Reference Example 1, and nylon-6 (manufactured by Toyobo Co., Ltd.,
A composition consisting of 10 parts of T-803), 2 parts of Epicron 3050 (trade name), and 0.2 parts of Irganox 1010 (trade name) was prepared, molded, and evaluated in the same manner as in Example 1. The results are shown in Table 1. Example 3 In Example 2, 60 parts of PBT, nylon-6
It was molded and evaluated in the same manner except that the quantity ratio was changed to 20 parts. Example 4 Molding and evaluation were carried out in the same manner as in Example 2, except that 10 parts of nylon-66 (manufactured by Toray Industries, Inc., CM-3001N) was used instead of nylon-6. The results are shown in Table 1. Example 5 Molding and evaluation were carried out in the same manner as in Example 2, except that 10 parts of the graft copolymer (b) obtained in Reference Example 2 was used instead of the graft copolymer (a). The results are shown in Table 1.

[Table] (Note) * Virtually no breakage

Claims (1)

[Claims] 1 (A) 95 to 50 parts by weight of thermoplastic polyester resin,
(B) Ethylene graft-polymerized with 0.01-10% by weight of unsaturated carboxylic acid or its anhydride and carbon number 3-6
5 to 50 parts by weight of a copolymer with α-olefin, (C)
Consisting of 2 to 50 parts by weight of a polyamide resin and (D) a polyepoxy compound, 0.1 to 10 parts by weight of (D) is added to a total of 100 parts by weight of (A), (B), and (C), and melt-mixed. A thermoplastic polyester resin composition.