JPH051302B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a polyester resin composition that has excellent mechanical properties, particularly impact resistance at low temperatures, and provides molded products with good appearance. <Prior Art> Aromatic polyesters represented by polyethylene terephthalate and polybutylene terephthalate are used in a wide range of fields such as electrical and electronic equipment parts and automobile parts due to their excellent properties. However, aromatic polyesters have poor impact resistance, particularly notched impact strength, and many methods for improving this have been proposed. Among them, α, β is used for the copolymer of ethylene and α-olefin shown in Japanese Patent Publication No. 57-54058.
- A method of melt-mixing a modified ethylene polymer obtained by grafting an unsaturated carboxylic acid or its acid derivative is relatively superior. <Problems to be solved by the invention> However, although these methods do show a comparative effect of improving impact resistance near room temperature, for example, at -30℃
There was a problem in that the impact resistance was significantly reduced in a low temperature atmosphere, and the appearance of the molded product was also poor. <Means and effects for solving the problems> Therefore, the present inventors conducted intensive studies to improve the above-mentioned problems of impact resistance at low temperatures and appearance of molded products. The above objective is achieved by incorporating a modified olefinic polymer obtained by grafting an unsaturated carboxylic acid or its derivative into a hydrogenated polymer of diene or a hydrogenated copolymer of a conjugated diene and an aromatic vinyl hydrocarbon. The present inventors have discovered that the same effects as those described above can be obtained in addition to improved rigidity when this composition contains an inorganic filler, and have thus arrived at the present invention. That is, the present invention provides 100 parts by weight of aromatic polyester, 0.01 to 10% by weight of unsaturated carboxylic acid or Relating to a polyester resin composition containing 1 to 100 parts by weight of a modified olefin polymer obtained by grafting a derivative thereof, and a polyester resin composition containing 1 to 150 parts by weight of an inorganic filler to this composition. It is something. The aromatic polyester used in the present invention is a polyester having an aromatic ring in the chain unit of the polymer, and whose main components are an aromatic dicarboxylic acid (or its ester-forming derivative) and a diol (or its ester-forming derivative). It is a polymer or copolymer obtained by a condensation reaction. The aromatic dicarboxylic acids mentioned here include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5
-Naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 3,3'-
biphenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid, 4,4'-diphenyl isopropylidene dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, 2,5-anthracenedicarboxylic acid, 2,6-anthracenedicarboxylic acid, 4,4'-p-terphenylenedicarboxylic acid, 2, 5-pyridinedicarboxylic acid, etc.
Terephthalic acid can be preferably used. Two or more of these aromatic dicarboxylic acids may be used in combination. If the amount is small, one or more aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid may be used in combination with these aromatic dicarboxylic acids. can. In addition, as diol components, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol,
Preferred examples include aliphatic diols such as diethylene glycol and triethylene glycol, alicyclic diols such as 1,4-cyclohexanedimethanol, and mixtures thereof. In addition, in small amounts, long-chain diols with a molecular weight of 400 to 6000, such as polyethylene glycol and poly-
One or more types of 1,3-propylene glycol, polytetramethylene glycol, etc. may be copolymerized. Specific preferred aromatic polyesters include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polyethylene-1,2-bis(phenoxy)ethane-4,4' - dicarboxylate, and copolymerized polyesters such as polyethylene isophthalate/terephthalate, polybutylene terephthalate/isophthalate, polybutylene terephthalate/decane dicarboxylate, and the like. Among these, polybutylene terephthalate, which has well-balanced mechanical properties, moldability, etc., can be particularly preferably used. The aromatic polyester used in the present invention is
It is preferable that the relative viscosity of a 0.5% o-chlorophenol solution measured at 25° C. is 1.15 to 2.0, particularly 1.3 to 1.85. If the relative viscosity of the aromatic polyester is less than 1.15, it will be difficult to obtain sufficient mechanical strength, and
If it exceeds 2.0, it is difficult to obtain a molded product with good gloss. Next, the modified olefin-based copolymer used in the present invention refers to a hydrogenated polymer of conjugated diene or a hydrogenated copolymer of conjugated diene and aromatic vinyl hydrocarbon, and 0.01 to 10% by weight of unsaturated carbon atoms. It is obtained by grafting an acid or its derivative. Hydrogenated polymers of conjugated dienes are polymers derived from one or more conjugated diene monomers, i.e., homopolymers of a single conjugated diene, such as 1,3-butadiene, or two or more conjugated dienes, e.g. 1,3-butadiene, isoprene (2-methyl-
1,3-butadiene), 2,3-dimethyl-1,
3-butadiene, 1,3-butadiene and 1,
A copolymer of 3-pentadiene in which at least 80% of the unsaturation content has been reduced by hydrogenation. Furthermore, hydrogenated copolymers of conjugated dienes and aromatic vinyl hydrocarbons are block copolymers or random copolymers with varying ratios of conjugated dienes and aromatic vinyl hydrocarbons, in which at least 80% of the unsaturated content is water. Refers to things that have been reduced by adding. in this case,
A block copolymer of a conjugated diene and an aromatic vinyl hydrocarbon is preferably used. Note that the double bond of the aromatic nucleus is excluded from the unsaturated bonds that are reduced by hydrogenation. Conjugated dienes used as raw materials for hydrogenated polymers and hydrogenated copolymers include 1,3-butadiene,
Isoprene (2,3-dimethyl-1,3-butadiene), 1,3-pentadiene, etc., and 1,
3-Butadiene and isoprene are preferably used. Aromatic vinyl hydrocarbons used as raw materials for hydrogenated copolymers include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene,
Examples include 1,3-dimethylstyrene and vinylnaphthalene, and styrene is preferably used. Preferred specific examples of the hydrogenated polymers and hydrogenated copolymers are hydrogenated polybutadiene, styrene/butadiene/styrene triblock hydrogenated copolymers,
Hydrogenated styrene/isoprene/styrene triblock copolymers are used, and styrene/butadiene/styrene triblock hydrogenated copolymers are more preferably used from the viewpoint of heat resistance. The above-mentioned hydrogenated copolymer of conjugated diene and hydrogenated copolymer of conjugated diene and aromatic vinyl hydrocarbon are grafted to produce a modified conjugated diene hydrogenated polymer and a modified conjugated diene/aromatic vinyl hydrocarbon hydrogenated copolymer. The unsaturated carboxylic acid from which the polymer is obtained is preferably acrylic acid, methacrylic acid, ethacrylic acid,
These include crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and butenedicarboxylic acid. Examples of derivatives thereof include alkyl esters, glycidyl esters, acid anhydrides, and imides. Among these, glycidyl esters, acid anhydrides, and imides are preferred. Preferred specific examples of unsaturated carboxylic acids or derivatives thereof include maleic acid, fumaric acid, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, diglycidyl itaconate, diglycidyl citraconate, and diglycidyl butene dicarboxylate. , butene dicarboxylic acid monoglycidyl ester, maleic anhydride, itaconic anhydride, citraconic anhydride, maleic acid imide, itaconic acid imide, citraconic acid imide, etc. In particular, glycidyl methacrylate, maleic anhydride, itaconic anhydride, maleic acid Acid imides can be preferably used. Two or more of these unsaturated epoxy monomers may be used in combination. The grafting reaction amount of unsaturated epoxy monomer is
It is necessary that the amount is 0.01 to 10% by weight, preferably 0.05 to 5% by weight. If the graft reaction amount of the unsaturated epoxy monomer is less than 0.01% by weight, the impact resistance will not be improved sufficiently, and if it exceeds 10% by weight, the heat resistance of the aromatic polyester will be impaired, etc. It is also not preferable. Note that the graft reaction here means that an unsaturated carboxylic acid or a derivative thereof is chemically bonded to an unmodified conjugated diene hydrogenated polymer or a conjugated diene/aromatic hydrocarbon hydrogenated copolymer. A modified hydrogenated polymer or a modified hydrogenated copolymer can be easily produced by adding an unsaturated carboxylic acid or its derivative to a hydrogenated polymer or hydrogenated copolymer and melt-kneading the mixture at 150 to 300°C. can be manufactured. As an apparatus for melt mixing, a screw extruder, a Banbury mixer, etc. can be used. This graft reaction is thought to proceed through a so-called "ene" reaction between the unsaturated bonds remaining in the hydrogenated polymer or copolymer and the unsaturated carboxylic acid or its derivative. Therefore, when using a hydrogenated polymer or hydrogenated copolymer obtained by hydrogenation at a high hydrogenation rate, it is necessary to mix the organic peroxide with the hydrogenated polymer or hydrogenated copolymer during melt mixing. The graft reaction can be efficiently caused by using 0.001 to 0.1%. Such organic peroxides preferably have a molecular weight of 200 or more. Specifically, tert-butylcumyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-
di(tert-butylperoxy)hexane, 2,5
-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, α,α'-di(tert-butylperoxy)diisopropylbenzene, and the like. The amount of the modified conjugated diene hydrogenated polymer or modified conjugated diene/aromatic vinyl hydrocarbon hydrogenated copolymer obtained by the graft reaction is 1 to 100 parts by weight, preferably 1 to 100 parts by weight, based on 100 parts by weight of the aromatic polyester. It is 3 to 60 parts by weight. If the amount added is less than 1 part by weight, the effect of improving impact resistance is small, and if it exceeds 100 parts by weight, the mechanical properties of the aromatic polyester tend to be impaired. Rigidity can be increased by further adding an inorganic filler to the composition of the present invention. Generally, when an inorganic filler is added, the impact resistance decreases greatly, but the composition of the present invention is characterized in that this decrease is small. Inorganic fillers that can be used in the present invention include fibrous fillers, granular fillers, and mixtures thereof. Examples of the fibrous reinforcing agent include inorganic fibers such as glass fibers, glass fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, metal fibers (eg, stainless steel fibers), and carbon fibers. In addition, examples of granular reinforcing agents include wollastenite, sericite, kaolin, mica, clay, pentonite,
Asbestos, talc, silicates such as alumina silicate, metal oxides such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, carbonates such as calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, etc. Examples include sulfates, glass beads, boron nitride, silicon carbide, Saroyan, etc., which may be hollow (e.g., hollow glass fibers, glass microballoons, glass balloons,
carbon balloons, etc.). Among these, glass fibers are preferred, and chopped strand or roving type glass fibers with a diameter of 5 to 15μ for ordinary reinforced resins are used, but they are easy to handle, give surface gloss to molded products, etc. 3-6 from the point of
A chopped strand with a length of mm is preferably used. In addition to inorganic fillers, those treated with ordinary coupling agents such as silane and titanium fillers are preferably used, and glass fibers and the like may also be treated with ordinary coupling agents such as epoxy resins and vinyl acetate. The amount of the inorganic filler added is 1 to 150 parts by weight, preferably 3 to 80 parts by weight, per 100 parts by weight of the aromatic polyester. The composition of the present invention may contain conventional additives such as antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, mold release agents, colorants including dyes and pigments, and nucleating agents to the extent that the purpose of the present invention is not impaired. One or more additives can be added. It is also possible to add small amounts of other thermoplastic resins. The method for producing the composition of the present invention is not particularly limited, but may include aromatic polyester, modified conjugated diene hydrogenated polymer, modified conjugated diene/aromatic vinyl hydrocarbon hydrogenated copolymer, and other materials as necessary. A method in which the additives are melt-kneaded using an extruder is preferred. The polyester resin composition produced according to the present invention can be easily molded by conventional methods such as injection molding and extrusion molding, and the molded product obtained exhibits excellent performance. <Example> The effects of the present invention will be explained in further detail with reference to Examples below. Reference Example 1 (Production of modified conjugated diene hydrogenated polymer) Maleic anhydride 4 was added to 100 parts by weight of a polybutadiene polymer with a residual unsaturation degree of 10% obtained by reducing the unsaturated bonds of polybutadiene by 90% hydrogenation.
Parts by weight were placed in a Henschel mixer through which nitrogen was passed, and stirred for 6 minutes to form a homogeneous mixture. This mixture was extruded using a 40mmφ extruder equipped with a dalmage-type screw at the tip of L/D28 at a screw rotation speed of 80 rpm and a cylinder temperature of 230°C to form pellets (A) of modified conjugated diene hydrogenated polymer. Obtained. After pulverizing the pellets, unreacted maleic anhydride was extracted with acetone using a Soxhlet extractor for 20 hours. After drying the pellets, a press film was made and the infrared absorption spectrum was measured.
Maleic anhydride was determined. As a result, it was found that 2.3% by weight of maleic anhydride had undergone a graft reaction. Reference Example 2 (Production of modified conjugated diene/aromatic vinyl hydrocarbon hydrogenated copolymer) A styrene/butadiene/styrene block copolymer with a butadiene to styrene ratio of 70:30 was produced.
4 parts by weight of maleic anhydride and 2,5-dimethyl-100 parts by weight of a styrene-butadiene/styrene triblock copolymer with a residual unsaturation of 2% obtained by hydrogenation reduction to about 98%.
2,5-di(tert-butylperoxy)hexane
0.025 parts by weight was pelletized in the same manner as in Reference Example 1 (C). Furthermore, when the amount of grafted maleic anhydride was quantified, it was found that 2.1% by weight of maleic anhydride had undergone the graft reaction. Reference Example 3 (Production of modified conjugated diene hydrogenated polymer and modified conjugated diene/aromatic vinyl hydrocarbon copolymer) Various unmodified conjugated diene hydrogenated polymers shown in Table 1 were produced in the same manner as Reference Example 1 or 2. A grafting reaction of various unsaturated carboxylic acid derivatives is performed on the unmodified conjugated diene/aromatic vinyl hydrocarbon hydrogenated copolymer to form a modified conjugated diene hydrogenated polymer and a modified conjugated diene/aromatic vinyl hydrocarbon. Hydrogenated copolymers (B, D, and E) were obtained. The results are shown in Table 1.

[Table] Examples 1 to 5, Comparative Examples 1 to 4 Polybutylene terephthalate with a relative viscosity of 1.75
To 100 parts by weight, the modified conjugated diene hydrogenated polymer or the modified conjugated diene/aromatic vinyl hydrocarbon hydrogenated copolymer produced in the above reference example was dry blended in the proportions shown in Table 2, and further using a 40 mmφ extruder. hand
The mixture was melted and kneaded at 250°C to form pellets. The pellets were dried with hot air at 130°C for 5 hours, then molded using a 5-ounce screw in-line injection molding machine set at 250°C, and subjected to ASTM No. 1 dumbbell and 1/4 inch wide Izot impact tests. I created a piece. The appearance of these test pieces was observed, and a tensile test and a notched isot impact test were conducted in an atmosphere of 23°C, and a notched isot impact test was conducted in an atmosphere of -40°C. The test results are shown in Table 2. The abbreviations for the modified conjugated diene hydrogenated polymer and the modified conjugated diene/aromatic vinyl hydrocarbon hydrogenated copolymer in the table correspond to those in Table 1.

[Table] As is clear from the results in Table 2, a modified conjugated diene partially hydrogenated polymer grafted with an unsaturated carboxylic acid or its derivative and a modified conjugated diene/aromatic vinyl hydrocarbon partially hydrogenated copolymer were melt-mixed. It can be seen that the polyester resin composition of the present invention produced in this manner provides molded articles with excellent impact resistance and appearance at low temperatures. Examples 6 and 7, Comparative Examples 5 and 6 Polybutylene terephthalate with a relative viscosity of 1.48
To 100 parts by weight, 40 parts by weight of glass fiber (3 mm long chopped strand) and 20 parts by weight of modified conjugated diene/aromatic vinyl hydrocarbon hydrogenated copolymers C and D produced in Reference Examples 2 and 3 were added. The composition was tested in the same manner as in Example 1 at 23°C and -40°C.
The notched Izot impact value at °C was determined. The results are shown in Table 3. For comparison, Table 3 also shows an example in which the modified conjugated diene hydrogenated polymer was not added (Comparative Example 5) and an example in which an unmodified substance of C was used (Comparative Example 6).

[Table] ○: Good, ×: Bad As is clear from the results in Table 3, even when an inorganic filler is used, it can be obtained by melt-mixing a modified conjugated diene (/aromatic vinyl hydrocarbon) hydrogenated polymer. It can be seen that the polyester resin composition of the present invention has excellent impact resistance at low temperatures and excellent appearance of molded products. <Effects of the Present Invention> Molded articles made from the polyester resin composition of the present invention have excellent impact resistance at low temperatures and good appearance.

Claims (1)

[Scope of Claims] 100 parts by weight of aromatic polyester, 0.01 to 10% by weight of unsaturated carbon based on hydrogenated polymer of conjugated diene or hydrogenated copolymer of conjugated diene and aromatic vinyl hydrocarbon. A polyester resin composition containing 1 to 100 parts by weight of a modified olefin polymer obtained by grafting an acid or a derivative thereof. 2. The polyester resin composition according to claim 1, which contains 1 to 150 parts by weight of an inorganic filler per 100 polymerized parts of the aromatic polyester.