JP3020708B2 - Polyethylene terephthalate resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyethylene terephthalate resin composition. More specifically,
Excellent flame retardancy and well-balanced performance, excellent moldability, especially excellent fluidity, thermal stability during molding, that is, little decomposition and volatile gas during molding, and heat treatment of molded products at high temperature for a long time Gas burning of molded products, deformation of surface appearance,
The present invention relates to a polyethylene terephthalate resin composition which can be molded without discoloration and has excellent mechanical strength.

[0002]

2. Description of the Related Art Conventionally, polyethylene terephthalate has been widely used for mechanical parts, electric and electronic parts, etc. by utilizing its excellent characteristics.

[0003] On the other hand, materials for use in mechanical and electric / electronic parts are required to have high flame retardancy in addition to mechanical strength. Characteristics that do not bleed out on the product surface are required. In recent years, materials for electric and electronic applications such as connectors and transformers have been required to have moldability, particularly high fluidity, as molded products have become smaller, thinner and more complicated.

[0004] Examples of flame retardants for polyethylene terephthalate that have been developed include halogenated polycarbonates (JP-A-48-52834) and halogenated epoxy resins (JP-B-53-18068). These flame retardants contribute to the flame retardancy of the polyethylene terephthalate resin composition and do not cause bleed-out.

[0005] However, these flame retardants increase the melt viscosity of the polyethylene terephthalate resin composition and cause a decrease in the fluidity of the melt.

As a non-bleed type flame retardant, brominated polystyrene, especially tribromopolystyrene (JP-B-57-39264) can be mentioned. This flame retardant provides a polyethylene terephthalate resin composition which has a small amount of decomposition volatile gas during molding and is excellent in mechanical strength.

However, this flame retardant also increases the melt viscosity of the polyethylene terephthalate resin composition, and is particularly unsuitable as a material that requires high fluidity as a melt when molding connectors and transformers. It is.

[0008]

As described above, there is a demand for a technique which satisfies not only flame retardancy and non-bleeding property but also improvement in thermal stability, suppression of decomposition and volatile gas, and high fluidity at the same time and at a high level. It is rare.

An object of the present invention is to provide such a technique.

[0010]

The present invention provides:
(A) polyethylene terephthalate 20 to 80% by weight
(In the whole composition), (B) 0 to 60% by weight of the inorganic filler (in the whole composition), (C) a mixture 2 of dibromopolystyrene and tribromopolystyrene having a mixing ratio of 1: 9 to 9: 1. It is a polyethylene terephthalate resin composition containing 0.025 to 25% by weight (in the whole composition) and 2.0 to 15% by weight (in the whole composition) of (D) an antimony-based flame retardant aid.

Hereinafter, the components of the polyethylene terephthalate resin composition of the present invention will be described in detail.

First, (A) polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) used in the present invention comprises, for example, a dicarboxylic acid composed of at least 90 mol% of terephthalic acid or an ester-forming derivative component thereof, A polymer obtained by subjecting at least 90 mol% of a glycol component which is ethylene glycol to an esterification reaction or a transesterification reaction, followed by a polycondensation reaction.

Preferred examples of the ester-forming derivative of dicarboxylic acid include dialkyl esters and diaryl esters of terephthalic acid. Examples of the dicarboxylic acid that can be used together with terephthalic acid in the range of 10 mol% or less as a dicarboxylic acid component include phthalic acid,
Isophthalic acid, adipic acid, sebacic acid, naphthalene
Examples thereof include 1,4- or 2,6-dicarboxylic acid and diphenylether-4,4'-dicarboxylic acid.

Glycols which can be used together in a range of not more than 10 mol% with respect to ethylene glycol as a glycol component include propylene glycol, butylene glycol, neopentyl glycol, cyclohexanedimethanol, 2,2-bis (4- Glycols such as (hydroxyphenyl) propane can be mentioned. Other components that can be used when obtaining polyethylene terephthalate include oxyacids such as p-hydroxybenzoic acid and p-hydroxyethoxybenzoic acid.

The degree of polymerization of the polyethylene terephthalate used in the present invention is not particularly limited, but the intrinsic viscosity (at 35 ° C. in orthochlorophenol) is 0.4 to 0.4.
1.0 is preferred.

In the polyethylene terephthalate resin composition of the present invention, the polyethylene terephthalate accounts for 20 to 80% by weight of the total composition. If the amount of polyethylene terephthalate is less than 20% by weight, molding processability becomes difficult, while if it exceeds 80% by weight, there is a problem in mechanical strength of the molded article.

Next, in the present invention, the inorganic filler (B) is preferably blended in order to obtain a molded article having excellent properties such as mechanical strength, heat resistance and dimensional stability.

(B) As the inorganic filler, glass fiber,
Fibrous fillers such as graphite fiber, aramid fiber, silica fiber, and alumina fiber; powdered and granular fillers such as carbon black, silica, whiskers, glass beads, calcium silicate, kaolin, wollastonite, mica, and glass flakes And the like can be used.

These inorganic fillers can be used alone or in combination of two or more.

In using these inorganic fillers,
If necessary, it is desirable to use a sizing agent or a surface treatment agent in combination. This example is a functional compound such as an epoxy compound, an isocyanate compound, a silane compound and a titanate compound.

These compounds may be used by previously subjecting an inorganic filler to a surface treatment or a convergence treatment, or may be added simultaneously with the preparation of the material.

In the present invention, the amount of the inorganic filler (B) is from 0 to 60% by weight, preferably from 5 to 50% by weight. If the amount of the inorganic filler exceeds 60% by weight, molding becomes difficult, and there is a problem in the mechanical strength of the molded product. The amount of the functional surface treating agent used in combination is 1 to 10% by weight, preferably 0.1 to 10% by weight, based on the inorganic filler.
0.5 to 5% by weight.

Next, the dibromopolystyrene and tribromopolystyrene of the component (C) used in the present invention function as a flame retardant.

(C) The mixing ratio of the mixture of dibromopolystyrene and tribromopolystyrene is as follows: dibromopolystyrene: tribromopolystyrene = 1: 9 to 9:
1, preferably from 2: 8 to 8: 2. If the dibromopolystyrene ratio is less than 1, the melt viscosity of the obtained composition increases, and the fluidity decreases. Further, when the ratio of dibromopolystyrene exceeds 9, the mechanical strength decreases, which is not preferable. The total amount of dibromopolystyrene and tribromopolystyrene is from 2.0 to 25% by weight, preferably from 5.0 to 20% by weight, based on the total composition. If the amount is less than 1% by weight, the resulting molded article will not have a flame-retardant effect.

Further, the antimony-based flame retardant of component (D) used in the present invention, as the flame retardant of two kinds of brominated polystyrenes having different chemical compositions (C), further improves the flame retardant effect. To mix.

Examples of the (D) an antimony-based flame retardant aid, antimony trioxide, antimony tetroxide, antimony pentoxide, the general formula _{(NaQ) p · Sb 2 O} 5 · QH 2 O (p 0.4~0 And Q is water of crystallization,
And a sodium salt of antimony pentoxide, and sodium antimonate, among which sodium antimonate is most preferable.

(D) The compounding amount of the antimony-based flame retardant is 2.0 to 15% by weight in the total composition, preferably 3.
0 to 10% by weight. If the compounding amount is less than 1% by weight, the flame retardancy becomes insufficient, and if it is 15% by weight or more, the decomposition of the resin and the compounding agent is promoted and the mechanical strength is reduced.

The polyethylene terephthalate resin composition of the present invention is further provided with known additives, for example, a lubricant other than the above-mentioned components, a nucleating agent, a release agent, an antistatic agent, in order to impart desired properties according to the purpose. Of course, it is also possible to incorporate a surfactant, a plasticizer, a coloring agent, a heat stabilizer, an ultraviolet stabilizer and the like.

The polyethylene terephthalate resin composition of the present invention can be easily prepared by known equipment and methods generally used as a conventional resin composition preparation method. For example, after mixing the respective components, kneading and extruding with an extruder to prepare pellets, and then molding, a method of once preparing pellets having a different composition, mixing a predetermined amount of the pellets, subjecting the mixture to molding, and then performing molding. Any method can be used, such as a method of obtaining a molded article of the composition, a method of directly charging one or more of each component to a molding machine, and the like. Mixing and adding a part of the resin component as a fine powder with other components is a preferable method for uniformly blending these components.

[0030]

EXAMPLES The present invention will be described more specifically with reference to the following examples.

Polyethylene terephthalate (hereinafter, PE)
T), glass fiber, dibromopoly
With styrene, brominated polycarbonate, brominated epoxy
The following were used. (A) Component - Dimethyl terephthalate and ethylene glycol
Using titanium tetrabutoxide as catalyst
After transesterification by heating, the temperature was raised under reduced pressure to remove potassium iodide.
Polyethylene terephthalate obtained by adding
(Intrinsic viscosity measured at 35 ° C in orthochlorophenol
Is 0.7) (B) Component : chopped stra with a glass fiber diameter of 10.5 µm and a cut length of 3 mm
And Polydibromostyrene (C) component manufactured by NEC Corporation ( dibromopolystyrene in the table )
Denoted) PDBS-80: in US GLC Ltd., polytribromostyrene (Table, tribromo Police Ji
Ren and notation) Pyro check 68PB: Nissan Ferro Organic Chemical Co., Ltd., brominated polycarbonate FG7200: manufactured by Teijin Kasei Co., Ltd., brominated epoxy F2300H: Israel Dead Sea Bromine Company
Ltd. The measurement of the characteristic evaluation shown in the embodiment are as follows.

Physical property measurement method Tensile test According to ASTM D 638, Izod impact strength According to ASTM D 256.

Residue test in molding machine (thermal stability) A sample is retained in a cylinder of a molding machine at a cylinder temperature of 280 ° C for 30 minutes, then molded, and the tensile strength of a molded test piece is measured to determine thermal stability and deterioration. Was used as a guide to evaluate the degree of

Flammability test (UL-94) Subject 9 of Underwriters Laboratories
5 (UL-94), 5 test pieces (thickness:
(1/32 inch).

Method of Measuring Fluidity Molding was carried out using a rod flow length measuring test mold (cavity: width 10 mm × thickness 0.7 mm) under the following conditions, and flow was determined from the flow length (molded product length). The sex was evaluated. # Molding conditions: Cylinder temperature: 280 ° C Injection pressure: 100 kg / cm ² Mold temperature: 80 ° C

Inspection of appearance of molded article A disk (100 mm diameter, 3 mm thickness) was molded, and the presence or absence and degree of abnormal spots were visually observed, and judged according to the following ranks. # Spots: ○: None △: Slightly present ×: Many present

Evaluation of bromine generation A cylindrical glass container is placed in the flow path of the heated air at 300 ° C., and the resin is sealed therein and immersed in an oil bath at 300 ° C. Guides the circulating air into pure water and converts the generated bromine into HB
Collect for 1 hour as r. This aqueous solution was analyzed by ion chromatography for HBr generation weight ppm relative to the encapsulated resin.
Was measured.

Method for Measuring Melt Viscosity The melt viscosity was evaluated by using a Shimadzu Flow Tester Model CFT-500A manufactured by Shimadzu Corporation under the following conditions. # Measurement conditions: Cylinder temperature: 270 ° C Preheating time: 5 min Extrusion load: 100 kgf Die: 1 mm in diameter, 10 mm in length

[0039]

Examples 1 to 13 and Comparative Examples 1 to 30 Intrinsic viscosity (35
The components shown in Table 1 were added to polyethylene terephthalate (0.7 ° C., in orthochlorophenol) at 0.7 in the amount shown in Table 1 and mixed, and then a pellet composition was prepared using an extruder. Next, various test pieces were prepared by using the pellets or by injection molding from the pellets, and the above evaluation was performed. The results are shown in Tables 1 to 5.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

[Table 4]

[0044]

[Table 5]

[0045]

The polyethylene terephthalate resin composition of the present invention has the following properties which are effectively improved and has a well-balanced function. Low generation of decomposition volatile gas due to excellent thermal stability. High fluidity. There is little thermal deterioration of the molded product and little decrease in strength. No occurrence of unusual spots on the molded product is observed. Excellent mechanical properties such as tensile properties and Izod impact strength.

Continuation of front page (56) References JP-A-3-139555 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 67 / 02,25 / 18 C08K 3 / 00,3 /twenty two

Claims (1)

(57) [Claims] (1) polyethylene terephthalate (A)
80% by weight (in the whole composition), (B) inorganic filler 0 to 60
% By weight (in all compositions), (C) a mixing ratio of 1: 9 to 9: 1
2.0 to 25% by weight (in the whole composition) of a mixture of dibromopolystyrene and tribromopolystyrene, and (D) 2.0 to 15% by weight (in the whole composition) of an antimony-based flame retardant auxiliary. Polyethylene terephthalate resin composition.