JPH0689233B2 - Hydrolysis resistant polyester composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyester composition for molded articles which has excellent hydrolysis resistance.

[Prior Art] Conventionally, as a polyester resin having hydrolysis resistance, a polybutylene terephthalate resin blended with a polypropylene resin excellent in water resistance in the presence of a fibrous inorganic filler (Japanese Patent Laid-Open No. 49-120949). (See Japanese Patent Laid-Open Publication No. 1989), a glass fiber surface-treated with a polyfunctional epoxy compound and a thermoplastic polyester resin added with montan wax (JP-A-55).
-52340 gazette). Polyester mainly composed of dicarboxylic acid excellent in hydrolysis resistance (Japanese Patent Application Laid-Open No. 50-48058)
JP-A-60-112850), a polyester composition in which a specific epoxy compound or an aromatic urethane compound is added to reduce the amount of terminal carboxyl groups (JP-A-60-112850).
57-12054, JP-A-57-36148 and JP-A-51-73050) are known.

[Problems to be Solved by the Invention] However, these conventional polyester compositions have insufficient heat resistance stability at high temperatures, and thus require a new stabilization technique (see JP-A-54-21454). Further, there is a problem that the original mechanical properties, surface appearance, heat resistance, etc. of polyester are impaired as the hydrolysis resistance is improved.

Therefore, an object of the present invention is to provide a polyester composition having significantly improved hydrolysis resistance without impairing the original mechanical properties, surface appearance, heat resistance and the like of polyester.

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, by adding a certain amount of both a polyolefin and a specific monoepoxy compound to a polyester resin, the original polyester The present invention was completed by discovering that hydrolysis resistance was significantly improved without impairing the properties of That is, the present invention is a polyester composition containing 100 parts by weight of polyester, 1 to 20 parts by weight of polyolefin, and 0.1 to 15 parts by weight of a monoepoxy compound represented by the following formula and having a molecular weight of 1000 or less and an epoxy equivalent of 300 or less.

(Wherein R is phthalimide, tetrahydrophthalimide, phenyl, phenoxy, benzoyloxy, cycloalkyl, cycloalkyloxy or cycloalkylcarbonyloxy).

The polyester used in the present invention is obtained by condensing a polybasic acid, particularly a dicarboxylic acid, and a polyhydric alcohol, especially a glycol. Examples of the dicarboxylic acid include phthalic acid (terephthalic acid, isophthalic acid), naphthalenedicarboxylic acid, diphenyldicarboxylic acid, maleic acid, fumaric acid, succinic acid, adipic acid, and the like. Among these, phthalic acid, particularly terephthalic acid Is preferred. As glycol, ethylene glycol, diethylene glycol,
Examples thereof include triethylene glycol, propylene glycol, butylene glycol, and of these, butylene glycol is preferable. In particular, poly (1,4-butylene terephthalate) is a useful resin, but since it is easily hydrolyzed, the effect of the present invention is particularly remarkable in the resin.

The polyolefin referred to in the present invention includes a high-pressure method, a polyethylene polymerized by a medium-pressure method and a low-pressure method, polypropylene,
And other polyolefins: glycidyl methacrylate modified polyolefins and copolymers or graft polymers of olefins with vinyl compounds and / or acrylic compounds.

The polyolefin is 1 to 20 parts by weight, preferably 2 to 15 parts by weight, and particularly 2 to 100 parts by weight of the polyester.
It is added in the range of 7 parts by weight. If the amount is less than 1 part by weight, the effect of the present invention does not occur. If it is more than 20 parts by weight, the initial mechanical properties will change, and new problems such as delamination may occur depending on the type of the polyolefin added.

The epoxy compound is added in an amount of 0.1 to 15 parts by weight, preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the polyester. The epoxy compound has a molecular weight of 1,00.
Those with 0 and epoxy equivalent over 300 are not preferable. A monofunctional epoxy compound having an epoxy equivalent of 100 to 300 is preferable in order to obtain good moldability and surface appearance.

The polyester composition of the present invention comprises at least one compound selected from the group consisting of 0-60 wt% inorganic filler, 7-17 wt% brominated polycarbonate, brominated epoxy compound and brominated polystyrene, and 2 ~ 5% by weight
Further strengthened by adding antimony oxide,
A flame-retardant hydrolysis-resistant polyester composition can be obtained.

The inorganic filler referred to in the present invention includes glass fiber, asbestos,
Mica, clay, talc, etc. are included, and among these, glass fiber is preferable. The amount of the inorganic filler added may be varied in the range of 0 to 60% by weight based on the total weight of the polyester composition depending on the application of the polyester composition.

The brominated polycarbonate in the present invention includes brominated polycarbonate in a broad and general sense, and among them, those having a structure obtained by condensation of bisphenol A and phosgene, particularly those represented by the formula: (In the formula, n = 4 to 100), which is a carbonate oligomer of tetrabromobisphenol A or a bisphenol A / tetrabromobisphenol A carbonate copolymer.

The brominated epoxy compound referred to in the present invention generally includes all that can be added for the purpose of making plastics flame-retardant, and is not limited to a particular one, but is particularly (In the formula, n = 4 to 50).

Brominated polystyrene used in the present invention can be widely used from low molecular weight ones called oligomers to three-dimensional infinite molecular weight ones, and is a polymer obtained by the monomer of the following general formula, The brominated styrene-based monomer may be polymerized, or the styrene-based monomer may be polymerized and then brominated, and one kind or two or more kinds may be used.

(In the formula, R is hydrogen, bromine, lower alkyl, brominated lower alkyl, X _{1 to} X ₅ are any of vinyl, bromine, hydrogen, lower alkyl lower brominated alkyl, and X ₁
At least one of ~ X ₅ is a bromine atom. Specific examples of the constituent monomers include bromostyrene, 2,6-dibromostyrene, 2,4,6-tribromostyrene, α-methyl-bromostyrene, 2,6-dibromo-4-methylstyrene, penta Examples thereof include bromostyrene and 2,6-bromo-1,4-divinylbenzene.

The polyester composition of the present invention may further contain conventional additives such as dyes, pigments, stabilizers and lubricants.

[Examples] Examples of the present invention will be shown below, but the present invention is not limited thereto.

Examples 1-1 to 1-2 and Comparative Examples 1-1 to 1-4 The components shown below were sufficiently mixed in a ratio shown in Table 1 using a super mixer.

Polyester: VALOX (trademark, manufactured by General Electric Company), poly (1,4-butylene terephthalate); intrinsic viscosity 0.4dl /
g or more (mixing ratio of phenol and tetrachloroethane 60:
(Measured in 40 solvents at a temperature of 30 ° C.) Polyolefin: NUC6570 (trademark, manufactured by Nippon Unicar Co., Ltd.); (In the formula, m and n are integers) Polyethylene-ethyl acrylate NUC PES-20 (trademark, manufactured by Nippon Unicar Co., Ltd.); Linear low-density polyethylene epoxy compound represented by the formula CH ₂ —CH ₂ n: Denacol EX-741 (Trademark, manufactured by Nagase Kasei Co., Ltd.); It is represented by.

The obtained mixture was melt-kneaded and extruded at a temperature of about 260 ° C. using a single-screw extruder (65 mm) to produce pellets.

Using a JSW40 injection molding machine, these pellets were cut into strips (3.2 mm x
12 mm x 63 mm) and ASTM No. 5 tensile dumbbell were formed into test pieces.

A test piece was placed and sealed so that the autoclave container containing water was not in direct contact with water. After leaving these containers in an oven at 120 ° C. for 25 hours, 50 hours, and 100 hours, the bending strength, bending elasticity, tensile strength, and tensile elongation of each test piece were measured. In addition, the test piece which did not perform such a humidification heating process was used for the control test. The change in surface appearance was visually determined. The measurement results are as shown in Table 1. Further, the number average molecular weight and the weight average molecular weight of the test pieces of Example 1-1 and Comparative example 1-1 were measured. The measurement results are shown in Table 2.

Examples 2-1 to 2-2 and Comparative Examples 2-1 to 2-3 In the same manner as in Examples 1-1 to 1-2 except that the components shown in Table 3 below were used in the proportions shown in Table 3. The test piece was manufactured and tested. The results are shown in Table 3.

Example 3 and Comparative Example 3 Test pieces were manufactured and tested in the same manner as in Examples 1-1 and 1-2 except that the components shown in Table 4 below were used in the proportions shown in Table 4. The results are shown in Table 4.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area C08L 69:00 63:00 25:18)

Claims (3)

[Claims] 1. A monoepoxy compound having a molecular weight of 1,000 or less and an epoxy equivalent of 300 or less, represented by the following formula: 100 to 100 parts by weight of polyester, 1 to 20 parts by weight of a polyolefin, and 0.1 to 15
Polyester composition containing parts by weight (Wherein R is phthalimide, tetrahydrophthalimide, phenyl, phenoxy, benzoyloxy, cycloalkyl, cycloalkyloxy or cycloalkylcarbonyloxy). 2. The polyester composition according to claim 1, wherein the amount of the polyolefin is 2 to 15 parts by weight and the amount of the epoxy compound is 0.2 to 5 parts by weight. 3. Selected from the group consisting of 0 to 60% by weight of inorganic filler, 7 to 17% by weight of brominated polycarbonate, brominated epoxy compound, and brominated polystyrene, based on the total weight of the polyester composition. A polyester composition according to claim 1 or 2 which comprises at least one compound and 2-5% by weight of antimony oxide.