JPH06271749A - Flame-retardant polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject compsn. which has a high m.p. and excellent flame retardancy, melt stability, and moldability by compounding a modified polycyclohexylenedimethylene terephthalate resin with a halogenated bisimide and an inorg. flame retardant aid. CONSTITUTION:This resin compsn. is obtd. by compounding 100 pts.wt. modified polycyclohexylenedimethylene terephthalate resin obtd. by copolymerizing an arom. dicarboxylic acid, an aliph. dihydroxy compd. component contg. at least 60mol% 1, 4-cyclohexanedimethanol, and a minor amt. of an ester-forming diol compd. of formula I (wherein A is a divalent org. group having at least one arom. ring; and R is a divalent org. group such as a 2-8C aliph. hydrocarbon group) with 1-50 pts.wt. halogenated bisimide of formula II (wherein R1 is a divalent org. group; and R2 and R3 are each a divalent org. group provided at least one of them has at least one halogen atom) and 0. 1-20 pts.wt. inorg. flame retardant aid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant polyester resin composition. More specifically, it is a composition having excellent flame retardancy, high melting point, improved thermal stability during melting, and excellent moldability (shortening of molding cycle), which is suitable for various electric parts and electronic parts. A resin composition to be used is provided.

[0002]

2. Description of the Related Art Crystalline thermoplastic polyester resins such as polyalkylene terephthalate resins have excellent mechanical properties, electrical properties, and other physical and chemical properties, and are It is used as a plastic in a wide range of applications such as automobiles and electric / electronic devices. Conventionally, generally for electric parts and the like, flame retardant-imparting polyester resin compositions have been used mainly for organic halogen-based flame retardants or further flame retardant aids for applications requiring flame retardancy. There is. However, as the applications are expanded and diversified, more advanced performance, peculiarity, or higher quality is often required. Among them, polycyclohexylene dimethylene terephthalate resin (PCT resin), which has cyclohexanedimethanol as a diol component, has a high melting point and can withstand solder reflow sufficiently. I am collecting. However, PCT
The resin has a drawback that it has poor thermal stability when melted and is difficult to process, and the flame stability treatment further deteriorates the thermal stability. The present inventors have found that it is effective to modify the diol component with a specific one in order to improve the thermal stability, and applied for a patent (Japanese Patent Application Laid-Open No. 4-261).
No. 423). However, such a diol-modified polycyclohexylene dimethylene terephthalate has a drawback that the crystallization rate is slower than that of polybutylene terephthalate and the molding cycle becomes long. As described above, it has been earnestly desired to develop a polyester resin composition having a high melting point, excellent flame retardancy and melt stability, and improved moldability.

[0003]

Means for Solving the Problems As a result of intensive studies by the present inventors in order to solve the above problems, a specific flame retardant and a specific diol-modified polycyclohexylene dimethylene terephthalate (modified PCT resin) were selected. It has been found that a resin composition having excellent flame retardancy and thermal stability and improved moldability can be obtained by combination, and the present invention has been completed. In this case, it was confirmed that the thermal deformation temperature was further improved by promoting the crystallization.
That is, the present invention provides (A) an aromatic dicarboxylic acid or an ester-forming derivative thereof.
An ester-forming diol compound (c) represented by the following general formula (I) containing (a) and an aliphatic dihydroxy compound (b) having 60% by mole or more of 1,4-cyclohexanedimethanol as main components. 100 parts by weight of modified polycyclohexylene dimethylene terephthalate resin obtained by copolymerizing HO-ROAOR-OH (I) (wherein A represents a divalent organic radical containing at least one aromatic ring) Represents a divalent organic radical selected from an aliphatic hydrocarbon group having 2 to 8 carbon atoms and a polyoxyalkylene group.) (B) 1 to 50 parts by weight of a halogenated bisimide represented by the following general formula (II)

[0004]

[Chemical 2]

(However, R ₁ represents a divalent organic group, and R ₂ and
At least one of R _3's represents a divalent organic group having at least one halogen atom. (C) A flame-retardant polyester resin composition containing 0.1 to 20 parts by weight of an inorganic flame-retardant aid, and a molded article obtained by molding the same.

The constituent components of the flame-retardant polyester resin composition of the present invention will be described in detail below step by step. First, the basic skeleton of the (A) modified polycyclohexylene dimethylene terephthalate resin (modified PCT resin) used in the present invention comprises an aromatic dicarboxylic acid or its ester-forming derivative (a) and 60 mol% or more of 1,4 It is obtained by polycondensation with an aliphatic dihydroxy compound (b) which is cyclohexanedimethanol as a main component. Examples of the aromatic dicarboxylic acid or its ester-forming derivative (a) used here include terephthalic acid, isophthalic acid,
Known aromatic dicarboxylic acids such as naphthalenedicarboxylic acid and diphenyldicarboxylic acid, and ester-forming derivatives thereof, for example, dialkyl esters, diphenyl esters or other diacylated products of the above dicarboxylic acids, and one kind or a mixture of two or more kinds. Can be used. Next, the aliphatic dihydroxy compound (b) which is the other component for constituting the basic skeleton of the modified PCT resin of the present invention
Is mainly composed of 1,4-cyclohexanedimethanol, and the proportion thereof is 60 mol% or more in the component (b). If the proportion of 1,4-cyclohexanedimethanol is lower than this range, it is difficult to obtain a polyester resin having high heat resistance. Preferably, 1,4-occupying the component (b)
The proportion of cyclohexanedimethanol is 70 mol% or more. As such 1,4-cyclohexanedimethanol, cis-type and trans-type stereoisomers are known due to the structure of the cyclohexane ring. In the present invention, any of them may be used, and a mixture thereof may be used, but in view of the heat resistance performance of the obtained polyester resin, the preferable ratio of cis isomer / trans isomer is The ratio is 40/60 to 0/100, particularly preferably 35/65 to 5/95. Examples of aliphatic dihydroxy compounds other than 1,4-cyclohexanedimethanol include aliphatic dihydroxy compounds such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, hexanediol, cyclohexanediol, diethylene glycol and triethylene glycol. These are compounds and substitution products thereof, and one kind or a mixture of two or more kinds can be used. Further, these other trifunctional monomers, that is, trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, trimethylolpropane and the like may be used in a small amount in combination to form a polyester having a branched or crosslinked structure.

Another essential constituent unit constituting the modified PCT resin used in the present invention is an ester-forming diol compound (c) represented by the following general formula (I). In the present invention,
It is preferable to use a polyester obtained by copolymerizing the component (c) so that the introduction ratio thereof with respect to the aromatic dicarboxylic acid group is 0.1 to 30 mol%. HO-ROAOR-OH (I) (In the formula, A represents a divalent organic radical containing at least one aromatic ring. R is selected from an aliphatic hydrocarbon group having 2 to 8 carbon atoms and a polyoxyalkylene group. The divalent organic radical represented by A is, for example, an arylene group or a substituted arylene group.
Examples thereof include a phenylene group, a naphthylene group, a diphenylene group, and a group represented by the following formula (III).

[0008]

[Chemical 3]

(Wherein Q is an oxy group, a sulfonyl group, a carbonyl group, a methylene group, a dichloromethylene group, an ethylidene group, a butylidene group, a 2,2-propylidene group, a 1,1-
A phenethylidene group, a phenylenebis (2,2-propylidene) group and the like are shown, L is an alkyl group having 1 to 4 carbon atoms or halogen, and m and n are integers of 0 to 4, respectively. ) Preferably, a 2,2-bis (4-phenylene) propane group, 4,4'-
A biphenylene group, a phenylene group, an oxy 4,4'-diphenylene group and a naphthylene group. In the general formula (I),
The divalent organic radical represented by R is, for example, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, neopentylene group, hexylene group, polyoxyethylene group, polyoxypropylene group, polyoxyisopropylene group. Groups and the like. Of these, an ethylene group and an isopropylene group are preferable. A particularly preferable compound as the structural unit (I) is 2,2-bis [4-
(2-hydroxyethoxy) -phenylene] propane, 2,2-bis [4- (2-hydroxy-1-methylethoxy) -phenylene] propane and 4,4'-bis (2-hydroxyethoxy) biphenyl are listed. To be The rate of introduction of these ester-forming diol compounds (c) is preferably 0.1 to 30 mol%, more preferably 0.5 to 20 mol%, and particularly preferably, expressed in terms of mole fraction with respect to the aromatic dicarboxylic acid component. 2.0 to 15 mol%. The above value is 0.
If it is less than 1 mol%, the effect of the present invention is hardly exhibited. Further, when it exceeds 30 mol%, the melting point, the degree of crystallinity or the like remarkably changes as compared with the original polyester, and the heat resistance which is the greatest feature of such a resin may be greatly impaired. Is not fully exerted.

These modified PCT resins can be produced using conventional polyester production methods. That is,
By heating each monomer to about 150 to 280 ℃ in the presence of a catalyst to carry out esterification or transesterification, etc., and then carrying out polycondensation while distilling off excess monomer or eliminated components under reduced pressure, the copolymerization A coalescence is obtained. At this time, as a catalyst to be used, tetraalkoxy titanium such as tetrabutoxy titanium, titanium oxalate metal salt such as potassium titanium oxalate, tin compound such as dibutyltin oxide or dibutyltin laurate, zinc acetate, lead acetate, manganese acetate, Alternatively, known catalysts that are generally useful for the polycondensation reaction of polyester, such as metal acetates such as calcium acetate and antimony compounds such as antimony trioxide, may be used alone or in combination of two or more kinds. In order to increase the molecular weight of the polymer (including oligomer) obtained by melt polymerization or solution polymerization in the present invention, the polymer is treated in vacuum or in an inert gas at a high temperature within a range where particles do not fuse for a required time. What is called solid phase polymerization may be performed. The molecular weight is preferably 0.6 to 1.8 as an intrinsic viscosity, and particularly preferably 0.7 to 1.5.

Next, in the present invention, the halogenated bisimide as the component (B) to be blended with the modified PCT resin (A) is a compound represented by the following general formula (II).

[0012]

[Chemical 4]

R ₁ is a divalent organic group, generally an alkylene group or an arylene group, and particularly preferably a lower alkylene group. For example, methylene, ethylene, 1,4-butylene, 1,6-hexamethylene, phenylene, 4,4'-methylenediphenylene, 4,4'-oxydiphenylene, xylylene, tetrachloroxylylene, tetrabromoxylylene. Etc. are exemplified, and among them, ethylene, butylene and hexamethylene groups are preferable. Also, R ₂
And R ₃ is at least one, preferably both are a divalent organic group having one or more halogens, preferably a halogenated aromatic divalent group, and a divalent group having 1 to 4 halogens. The phenylene group of is general. The halogen is preferably bromine, particularly preferably 4-
It is a bromophenylene group. Examples of the bisimide represented by the formula (II) as the component (B) include the following. N, N '
-(P and m-phenylene) -bis [3,4,5,6-tetra-chlorophthalimide], N, N '-(p and m-phenylene) -bis [3,4,5,6-tetra- Bromophthalimide], N, N '-(methylene-di-p-phenylene) -bis [3,4,5,6-tetrachlorophthalimide], N, N'-(methylene-di-p-phenylene) -bis [3,4,5,6-tetrabromophthalimide], N, N '-(oxy-di-p-phenylene) -bis [3,4,5,6-tetrachlorophthalimide], N, N'-( Oxy-di-p-phenylene) -bis [3,4,5,6-tetrabromophthalimide], N, N '-(p
And m-phenylene) -bischloroendimide, * N,
N '-(p and m-tetrachloroxylylene) -bis-
[3,4,5,6-Tetrachlorophthalimide], * N, N'-
(P and m-tetrachloroxylylene) -bis- [3.4
5-6-Tetrabromophthalimide], * N, N '-(p and m-tetrachloroxylylene) -bischloroendimide, N, N'-(1.2-ethylene) -bischloroendimide, N , N '-(1.2-Ethylene) -bis [3,4,5,6-tetrabromophthalimide], N, N'-bis (1,2,3,4,5-pentabromobenzyl) -pyro Meritimide, N, N'-bis (2,4,6-tribromophenyl) pyromellitimide. * In these, the tetrahaloxylylene group is 1
It is a 2,4,5-tetrahaloxylylene and a 1,3,4,5-tetrahaloxylylene group. Among them, preferred compounds include lower alkylenebistetrabromophthalimide, particularly N, N '.
-Ethylene bis tetrabromophthalimide. The blending amount of the component (B) is 1 to 50 parts by weight, preferably 1 to 25 parts by weight, more preferably 2 to 15 parts by weight, based on the modified PCT resin of the component (A). If it is too large, mechanical, physical properties, thermal stability, etc. are impaired and the appearance of the resin is impaired, such being undesirable. If it is too small, not only the flame retardancy becomes insufficient, but also the high cycle moldability is not sufficiently exerted.

Next, as the inorganic flame retardant aid (C) used in the present invention, antimony trioxide, antimony tetroxide, antimony pentoxide, antimony halide, sodium antimonate, aluminum hydroxide, magnesium hydroxide, Examples thereof include tin dioxide, zirconium oxide, zinc metaborate, barium borate, molybdenum oxide and the like. The amount of the flame retardant aid is 0.1 to 20 with respect to 100 parts by weight of the modified PCT resin (A).
Parts by weight, preferably 1 to 10 parts by weight. If the amount is less than 0.1 parts by weight, the flame retardancy of the composition will be poor, and if it exceeds 20 parts by weight, the strength of the composition will be reduced, and thus both are not preferable. Also, depending on the application, the composition may be required to have V-0 in the flame retardant category of UL standard 94, in which case asbestos or fluororesin (for example, polytetrafluoroethylene) or the like should be used in combination with the flame retardant. It is more preferable to use.

Next, in the present invention, the inorganic filler (D) is not an essential component, but a molded article excellent in performance such as mechanical strength, heat resistance, dimensional stability (deformation resistance, warpage), and electrical properties. In order to obtain the above, it is preferable to mix them, and a fibrous, powdery or plate-like filler is used for this purpose. Examples of the fibrous filler include glass fiber, carbon fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, stainless steel, aluminum, titanium, copper and brass. Inorganic fibrous substances such as metal fibrous substances.
A particularly representative fibrous filler is glass fiber or carbon fiber. High melting point organic fibrous substances such as polyamide and acrylic resin can also be used. On the other hand, powdered and granular fillers include silicates such as carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth and wollastonite, and oxidation. Iron, titanium oxide, zinc oxide, metal oxides such as alumina, calcium carbonate, metal carbonates such as magnesium carbonate, calcium sulfate, metal sulfates such as barium sulfate, other silicon carbide, silicon nitride, boron nitride, Examples include various metal powders. Further, as the plate-like filler, mica, glass flakes,
Examples include various metal foils. These inorganic fillers can be used alone or in combination of two or more. Fibrous filler,
Particularly, the combined use of the glass fiber and the granular and / or plate-like filler is a preferable combination particularly in terms of having both mechanical strength, dimensional accuracy, electrical properties and the like. When using these fillers, it is desirable to use a sizing agent or a surface treatment agent if necessary. If this example is shown, an epoxy compound,
It is a functional compound such as an isocyanate compound, a silane compound, and a titanate compound. These compounds may be subjected to a surface treatment or a converging treatment in advance, or may be added at the same time when the material is prepared. In the present invention, the amount of the inorganic filler compounded is 3 to 150 parts by weight, preferably 5 to 100 parts by weight, based on 100 parts by weight of the modified PCT resin (A). If the content of the inorganic filler exceeds 150 parts by weight, the molding process becomes difficult and the mechanical strength of the molded product becomes problematic. The amount of the functional surface-treating agent used in combination is 0 to 10% by weight, preferably 0.05
~ 5% by weight.

In the resin composition of the present invention, it is possible to supplementarily use a small amount of other thermoplastic resin within the range not impairing the purpose. As the other thermoplastic resin used here, any one may be used as long as it is a thermoplastic resin stable even at a high temperature even if it coexists with the modified PCT resin as described above. For example, polyamide, polystyrene, polycarbonate, polyurethane, polyethylene terephthalate,
It is also possible to blend polybutylene terephthalate, polyphenylene oxide, polyphenylene sulfide, polybutadiene, butyl rubber, a copolymer mainly containing polyacrylate (including a multi-layer graft copolymer) in an arbitrary ratio according to the purpose. In order to impart desired properties to the composition of the present invention according to its purpose, known substances generally added to thermoplastic resins and thermosetting resins, that is, antioxidants, heat stabilizers, ultraviolet absorbers, etc. It is also possible to add stabilizers, antistatic agents, colorants such as dyes and pigments, lubricants, plasticizers and crystallization accelerators, crystal nucleating agents and the like.

The composition of the present invention can be easily prepared by known equipment and methods generally used as conventional methods for preparing resin compositions. For example, i) after mixing the components, kneading and extruding with an extruder to prepare pellets,
After that, ii) once preparing pellets having different compositions, mixing a predetermined amount of the pellets, and subjecting to molding to obtain a molded article of the target composition after molding, iii) 1 or 2 of each component in a molding machine Any method such as a method of directly charging the above can be used. In addition, mixing a part of the resin component in the form of fine powder with the other components and adding it is a preferable method for uniformly blending these components.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
The measuring methods for evaluation of physical properties shown in the following examples are as follows. Tensile Strength and Elongation Tensile strength and elongation were measured according to ASTM D-638. Flammability test (UL-94) Subject 94 from Underwriters Laboratories
In accordance with the method of (UL94), five test pieces (thickness: 1/32 inch) were used to test the flame retardancy and the dropping characteristics when the resin burns. Limit molding cycle Molded product with a cylindrical bottom under the following conditions (outer diameter 40 mmφ, height 40 m
m, average wall thickness 5 mm) was molded, and the required time (seconds) at the limit of the molding cycle for obtaining a molded product with good appearance without deformation of the molded product was determined. The lower the number,
It shows that it has excellent high cycle moldability. Molding conditions Cylinder temperature: 300 ° C Ejection pressure: 1400kg / cm ² Mold temperature: 140 ° C Molding cycle: Injection holding pressure time was kept constant and cooling time was calculated. Deflection Temperature Under Load The deflection temperature under load was measured according to ASTM D-648. Measurement load: 18.6 kgf / cm ² retention MI 140 ° C., blow-dried pellets for 3 hours were filled in a melt indexer at 300 ° C., retained for 5 minutes and 20 minutes, and then MI was measured.

Production Example 1 (Production of modified PCT A-1) 100 mol of dimethyl terephthalate, 1,4-cyclohexanedimethanol (cis isomer / trans isomer = 25/7)
5) 120 mol and 8 mol of an ethylene oxide 2 mol adduct of bisphenol A were polymerized in the coexistence of 0.036 mol of tetrabutoxytitanium (catalyst) to obtain a modified polycyclohexylene dimethylene terephthalate. Further, this was subjected to solid phase polymerization at 250 ° C. under a vacuum of −76 cmHg. The intrinsic viscosity of the obtained polymer (A-1) is 1.0
Met. Production Example 2 (Production of modified PCT A-2) 100 mol of dimethyl terephthalate, 120 mol of 1,4-cyclohexanedimethanol, a comonomer represented by the following formula.
10 mol was polymerized in the same manner as modified PCT A-1 to obtain modified polycyclohexylene dimethylene terephthalate. The intrinsic viscosity of the obtained polymer (A-2) was 1.0.

[0020]

[Chemical 5]

Production Example 3 (Production of PCT A'-1) Polycyclohexylene dimethylene terephthalate was prepared under the same conditions as in Production Example 1 except that 2 mol of ethylene oxide adduct of bisphenol A was not added.

Examples 1 to 2 Ethylenebistetrabromophthalimide and antimony trioxide were added to the modified polycyclohexylene dimethylene terephthalate (A-1) prepared as described above in the composition shown in Table 1 and a Henschel mixer was used. After mixing with each other, the mixture was melt-kneaded at 300 ° C. in an extruder to prepare a pelletized composition. Then, a tensile test piece was molded from the pellets using an injection molding machine at a cylinder temperature of 300 ° C. and a mold temperature of 140 ° C., and the above evaluation was performed. The results are shown in Table 1.

Comparative Examples 1 and 2 In Example 1, modified PCT (A-1) was replaced with PCT.
A polyester composition was obtained in the same manner as in Example 1 except that (A'-1) was used. Similarly, a test piece was prepared from this composition and evaluated. The results are shown in Table 2.

Examples 3-5 Modified PCTs (A-1, A- produced as described above)
2) ethylene bis tetrabromophthalimide and an inorganic flame retardant aid, and optionally glass fiber with the composition shown in Table 1,
A polyester composition was obtained in the same manner as in Example 1. Similarly, a test piece was prepared from this composition and evaluated. The results are shown in Table 1.

Comparative Examples 3 to 5 As shown in Table 2, various polycyclohexylene dimethylene terephthalates were added with decabromodiphenyl ether or another flame retardant and a flame retardant auxiliary, and optionally glass fiber in combination. Compositions were prepared and evaluated as in Example 1. The results are shown in Table 2.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

As described above, the flame-retardant polyester resin composition of the present invention uses, as a base polyester, a modified polycyclohexylene dimethylene terephthalate obtained by copolymerizing a small amount of a specific comonomer component. High cycle molding is possible by using together with a flame retardant, and the deflection temperature under load is improved.
It is preferably used for electronic parts (connectors, switches, relays, etc.).

Claims (5)

[Claims] 1. An aromatic dicarboxylic acid or an ester-forming derivative thereof (a), and an aliphatic dihydroxy compound (b) in which 60 mol% or more is 1,4-cyclohexanedimethanol.
Modified polycyclohexylene dimethylene terephthalate resin obtained by copolymerizing an ester-forming diol compound (c) represented by the following general formula (I)
00 parts by weight of HO-ROAOR-OH (I) (In the formula, A represents a divalent organic radical containing at least one aromatic ring. R represents an aliphatic hydrocarbon group having 2 to 8 carbon atoms and a polyoxy group. A divalent organic radical selected from alkylene groups is shown.) (B) 1-50 parts by weight of a halogenated bisimide represented by the following general formula (II) and (However, R ₁ represents a divalent organic group, and at least one of R ₂ and R ₃ represents a divalent organic group having at least one halogen atom.) (C) Inorganic flame retardant aid A flame-retardant polyester resin composition containing 0.1 to 20 parts by weight. 2. The divalent organic radical A of the compound (C) represented by the general formula (I) is a 2,2-bis (4-phenylene) propane group, a phenylene group or an oxy 4,4'-diphenylene group. A flame-retardant polyester resin composition according to claim 1, which is a group or a naphthylene group, and R 1 is an ethylene group or an isopropylene group. 3. The flame-retardant polyester resin composition according to claim 1, wherein the halogenated bisimide as the component (B) is alkylenebistetrabromophthalimide. 4. A flame-retardant polyester resin composition comprising the composition according to claim 1 and 3 to 150 parts by weight of (D) an inorganic filler. 5. A molded article for electric or electronic parts, which is obtained by molding the composition according to any one of claims 1 to 4.