JPS6366345B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant resin composition, and more particularly to a flame-retardant polyester resin composition with excellent thermal stability. Thermoplastic polyesters, represented by polyethylene terephthalate and polybutylene terephthalate, have excellent chemical and mechanical properties and are widely used in fibers, films, plastics, etc., but in recent years, they have been used particularly in injection molding machines in the plastics field. It has come to be used in large quantities, being molded into electrical equipment parts, automobile interior and exterior parts, and other molded products. On the other hand, the physical properties of thermoplastic polyester can be further improved by adding various additives such as fibrous reinforcing materials such as glass fibers and carbon fibers, and functional agents such as inorganic fillers. Expanded as above. However, the shapes required for these molded products have recently become more complex, thinner, and smaller than ever before, reflecting social needs such as higher functionality, lighter weight, and resource conservation. . Therefore, it has become essential for thermoplastic polyester as a molding material to have excellent fluidity within a mold during molding. It has been known that the melt fluidity of thermoplastic polyester greatly depends on its molecular weight, and that the lower the molecular weight, the higher the fluidity. Therefore, thermoplastic polyesters with excellent fluidity and low molecular weight can be used as molding materials, but on the other hand, thermoplastic polyesters also have a high mechanical strength, especially the so-called toughness such as tensile elongation and bending deflection. It is known that the lower the molecular weight of polyester, the lower the toughness and strength. This means that if a thermoplastic polyester with a small molecular weight is used to improve the fluidity of a molding material, only a molded product with low toughness and strength will inevitably be obtained, and in particular, it is difficult to improve fluidity in order to make the molded product thinner. In cases where it is required, the reduction in strength due to the thinning of the wall and the reduction in strength due to the reduction in molecular weight often combine to make it unsuitable for actual use. In order to improve the strength of molded products, for example, thermoplastic polyester α-olefin and α,β-unsaturated carboxylic acid salts (Japanese Patent Publication No. 45-26225), copolymers of acrylic acid esters and ethylene ( JP-B No. 45-38908), polyacrylic aliphatic ester (JP-B No. 45-38909), or butyl rubber (JP-B No. 46-5224). Kimiaki
Methods by adding a compound such as those disclosed in Japanese Patent Publication No. 48-6175, Japanese Patent Publication No. 13860/1982, and Japanese Patent Publication No. 2193/1982) are known. However, all of these methods impair the fluidity of thermoplastic polyester.
Application to thin-walled moldings is accompanied by substantial restrictions. From this point of view, the inventors of the present invention have conducted extensive studies with the intention of improving the fluidity during molding, without impairing the toughness and strength of the molded product, and as a result of their intensive studies, the inventors have found that specific polycaprolactone can be added to thermoplastic polyester. It has been found that the above object can be achieved by blending a derivative. On the other hand, thermoplastic polyester is inherently thermoplastic, and once ignited, it does not extinguish even if the fire source is removed and burns gradually, so its application is limited.
Especially in the field of electrical and communication equipment, it has become a fatal flaw from a fire safety standpoint. For this reason, many attempts have been made to make thermoplastic polyester flame retardant. As one of the countermeasures,
It is known that an organic halogen compound as a flame retardant and antimony trioxide as a flame retardant aid are used in combination, and this has been put to practical use. However, when this flame retardant measure is applied to the thermoplastic polyester composition containing the polycaprolactone derivative, the thermal stability of the thermoplastic polyester composition during melt casting is impaired, and the properties of the resulting molded article are impaired. In particular, a decrease in mechanical strength is observed, and a new problem arises in that stable molding is difficult. The reason why the thermal stability of the above composition decreases during melt molding is unclear, but it is generally known that antimony trioxide acts as an excellent transesterification catalyst for thermoplastic polyester. Taking this into consideration, it is assumed that during melt molding, the polycaprolactone derivative and the thermoplastic polyester undergo a transesterification reaction due to the action of antimony trioxide, resulting in a significant reduction in molecular weight. As a result of intensive studies aimed at solving these problems, the inventors of the present invention found that when sodium antimonate is used in a thermoplastic polyester composition containing a polycaprolactone derivative and an organic halogen compound, the thermal stability of the composition is impaired. The present invention has been achieved based on the findings that the flame retardant effect is excellent even when the flame retardant effect is low. That is, the present invention provides (A) thermoplastic polyester
Per 100 parts by weight, (B) 0 to 200 parts by weight of filler, (C) 0.1 to 30 parts by weight of end-blocked polycaprolactone, (D)
This invention relates to a flame-retardant resin composition characterized in that it contains 0.1 to 20 parts by weight of sodium antimonate as an antimony element and 0.1 to 30 parts by weight of (E) an organic bromine compound as a bromine element. The thermoplastic polyester of component (A) used in the present invention is obtained by using terephthalic acid or its ester-forming derivative as the acid component and using a glycol having 2 to 10 carbon atoms or its ester-forming derivative as the glycol component. The main targets are linear saturated polyesters, such as polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate (polybutylene terephthalate), polyhexamethylene terephthalate, polycyclohexane 1,4-dimethylol terephthalate, polyneopentyl terephthalate, etc. Among these, polyethylene terephthalate and polybutylene terephthalate are particularly preferred. These thermoplastic polyesters can be used alone or in combination
It may be used as a mixed system of more than one species. Other polyesters may also be used, such as those in which part of the terephthalic acid component or the glycol component having 2 to 10 carbon atoms is replaced with another copolymer component as the acid component. Such copolymerization components include, for example, isophthalic acid and phthalic acid; halogen-substituted phthalic acids such as tetrabromophthalic acid and tetrabromoterephthalic acid; alkyl-substituted phthalic acids such as methylterephthalic acid and methylisophthalic acid;
- Naphthalene dicarboxylic acids such as naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, and 1,5-naphthalene dicarboxylic acid; diphenyl dicarboxylic acids such as 4,4'-diphenyl dicarboxylic acid and 3,4'-diphenyl dicarboxylic acid; Acids; 4,
Aromatic dicarboxylic acids such as 4'-diphenoxyethane dicarboxylic acid; aliphatic or alicyclic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, decadicarboxylic acid, cyclohexane dicarboxylic acid, etc.; trimethylene glycol ,
Aliphatic diols such as tetramethylene glycol, hexamethylene glycol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, etc.; dihydroxybenzenes such as hydroquinone, resorcinol, etc.; 2.
2-bis(4-hydroxyphenyl)propane,
Bisphenols such as bis(4-hydroxyphenyl) sulfone; aromatic diols such as ether diols obtained from bisphenols and glycols such as ethylene glycol; polyoxyethylene glycol, polyoxypropylene glycol, Examples include polyoxyalkylene glycols such as oxytetramethylene glycol; oxycarboxylic acids such as ε-oxycaproic acid, hydroxybenzoic acid, hydroxyethoxybenzoic acid, and the like. One or more of these copolymerization components can be used, and the proportion thereof is 20 mol% or less, especially 10 mol% or less, based on the total dicarboxylic acid (half of the amount of oxycarboxylic acid is calculated as carboxylic acid). It is preferable. Furthermore, these thermoplastic polyesters contain branching components such as tricarballylic acid, trimellisic acid,
An acid capable of forming a trifunctional ester such as trimellitic acid or a tetrafunctional ester such as pyromellitic acid, and/or glycerin, trimethylolpropane,
An alcohol capable of forming a trifunctional or tetrafunctional ester such as pentaerythritol may be copolymerized in an amount of 1.0 mol% or less, preferably 0.5 mol% or less, more preferably 0.3 mol% or less. The intrinsic viscosity of the thermoplastic polyester used here, especially polyethylene terephthalate, is preferably 0.35 or more, more preferably 0.45 or more, particularly 0.50 or more, when measured at 35° C. using an orthochlorophenol solvent. The above-mentioned thermoplastic polyester can be produced by a conventional production method, such as a melt polymerization reaction or a method combining this with a solid phase polymerization reaction. The filler of component (B) used in the present invention includes fibrous materials such as glass fiber, asbestos, carbon fiber, aromatic polyamide fiber, potassium titanate fiber, steel fiber, ceramic fiber, boron whisker fiber, etc., asbestos, Such as mica, silica, talc, calcium carbonate, glass beads, glass flakes, clay, wollastonite, etc.
Examples include powder, granular, or plate-like inorganic fillers. These fillers are usually blended as reinforcing materials, surface modifiers, or to modify electrical, thermal, and other properties. Among these fillers, especially when glass fiber is used, mechanical strength It exhibits a number of features such as greatly improved heat resistance and reduced mold shrinkage. There are no particular limitations on the glass fiber as long as it can generally be used for reinforcing resins. For example, it can be selected from long fiber type (glass roving), short fiber type chopped strand, milled fiber, etc. Further, the glass fibers may be treated with a sizing agent (eg, polyvinyl acetate, polyester sizing agent, etc.), a coupling agent (eg, silane compound, borane compound, etc.), or other surface treatment agent. Furthermore, it may be coated with a resin such as a thermoplastic resin or a thermosetting resin. usually,
The long fiber type glass fiber is used by cutting it into a desired length before or after blending with the resin, and this mode of use is also included in the present invention. The end-blocked polycaprolactone used in the present invention as component (C) has a number average molecular weight of 600 or more and 20,000 or more.
It means a polycaprolactone in which at least 50% of all end groups are terminated (hereinafter simply referred to as end-capped polycaprolactone). When this end-blocked polycaprolactone is blended in an appropriate amount with a thermoplastic polyester, it can improve the molding fluidity and also exhibit the effect of greatly improving the so-called toughness and strength of the molded product, such as tensile elongation and bending flexibility. End-blocked polycaprolactone is a polycaprolactone having a free carboxyl group and/or hydroxyl group at the end obtained by ring-opening polymerization of ε-caprolactone by a known method, and a monovalent compound that reacts with the carboxyl group or hydroxyl group. It can be produced by reacting with. Examples of the polymerization initiator used in the ring-opening polymerization of ε-caprolactone include n-hexyl alcohol,
Monohydric alcohols such as n-hebutyl alcohol, n-octyl alcohol, n-nonyl alcohol, lauryl alcohol, myristyl alcohol; e.g. ethylene glycol, propylene glycol, ethyl ethylene glycol, 2-methyl-1,2-propanediol, pinacol , β−
Glycols such as butylene glycol, diethylene glycol, tetramethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol; trihydric alcohols such as glycerin, 1,2,3-butanetriol, 1,2,3-pentanetriol, etc. e.g. elythrits,
Tetrahydric alcohols such as pentaerythritol; monohydric carboxylic acids such as benzoic acid, p-methylbenzoic acid, lauric acid, myridic acid; such as isophthalic acid, phthalic acid, terephthalic acid, 2,6-
Dicarboxylic acids such as naphthalene dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, decadicarboxylic acid, and cyclohexyne dicarboxylic acid; for example, tricarballylic acid, trimellisic acid ,
Trivalent carboxylic acids such as trimellitic acid; Tetravalent carboxylic acids such as pyromellitic acid; For example, ε-
Examples include oxycarboxylic acids such as oxycarboxylic acid and hydroxyethoxybenzoic acid. Furthermore, using these polymerization initiators, ε
- As a catalyst for accelerating the reaction during ring-opening polymerization of caprolactone, it is preferable to use a known ring-opening catalyst such as a tin-based catalyst such as tetraoctyltin diphenyltin dilaurate or a titanium-based catalyst such as tetrabutyl titanate. The type of terminal group in the polycaprolactone obtained in this way varies depending on the type of polymerization initiator used; hydroxyl group for alcohols, carboxyl group for carboxylic acids, hydroxyl group and carboxyl group for oxycarboxylic acids and water. Both become terminal groups. Among these, those using glycols as a polymerization initiator are preferred. These polycaprolactones must have at least 50%, preferably 70% or more of their total end groups blocked. Ideally, all terminal groups of polycaprolactone are capped, and this is particularly preferred. For this blocking, any monovalent compound can be used as long as it eliminates the activity of the terminal carboxyl group or terminal hydroxyl group of polycaprolactone. For example, ester bonds, ether bonds, urethane bonds, amide bonds, etc. are used for blocking, but blocking by ester bonds is preferred. Compounds used for blocking with ester bonds include, for example, monovalent carboxylic acids or ester-forming derivatives thereof when the terminal group is a hydroxyl group,
When the terminal group is a carboxyl group, monohydric alcohols or ester-forming derivatives thereof can be used. Examples of the monovalent carboxylic acids or their ester-forming derivatives include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, lauric acid, myristic acid,
Examples include carboxylic acids such as benzoic acid, toluic acid, dimethylbenzoic acid, ethylbenzoic acid, cumic acid, and 2,3,4,5-tetramethylbenzoic acid, and their acid anhydrides and acid halides. Examples of ester derivatives of carboxylic acids include phenyl acetate, ethyl caproate, methyl benzoate, and ethyl toluate. Examples of monohydric alcohols or ester-forming derivatives thereof include methyl alcohol, ethyl alcohol, n-
propyl alcohol, isopropyl alcohol,
isobutyl alcohol, n-amyl alcohol,
Examples include alcohols such as lauryl alcohol, halocarbonate esters and carboxylic acid esters thereof, and the like. A known esterification reaction can be used to obtain terminal-capped polycaprolactone by reacting polycaprolactone with monohydric alcohols or their ester-forming derivatives, or monovalent carboxylic acids or their ester-forming derivatives. can be easily obtained. Particularly preferred end-capped polycaprolactones have the general formula [R ¹² CO(-O(-CH ₂ )- ₅ CO)- _o O]- _n R ¹¹ [-
CO(−O(−CH ₂ )− ₅ CO)− _o ′OR ¹³ ] _n ′ [wherein R ¹¹ is an (m+m′)-valent organic group,
R ¹² and R ¹³ are each a monovalent organic group, n and n' are each a number of 2 or more, m and m' are each a number of 0 to 4, and (m+m') is 1 or more. ] It is polycaprolactone represented by In the general formula, when R ¹¹ is glycol,
m' becomes 0, m becomes 2, and R ¹² CO- represents the residue of the monovalent carboxylic acid used for blocking. Also
When R ¹¹ is a dicarboxylic acid, m is 0,
m' becomes 2, and -OR ¹² represents the residue of the monohydric alcohol used for blocking. Furthermore, when R ¹¹ is an oxycarboxylic acid, m and m' become 1,
R ¹² CO− is the residue of the monovalent carboxylic acid used for capping,
-OR ¹³ represents the residue of the monohydric alcohol used for blocking. By blending the end-capped polycaprolactone obtained in this way with thermoplastic polyester, it is possible to significantly improve molding fluidity and toughness, but the manifestation of these effects depends on the molecular weight of the end-capped polycaprolactone. When the number average molecular weight is larger than 20,000, it has no or almost no effect on improving toughness and strength, and when it is smaller than 600, the volatility is large. In addition, the thermal stability decreases, which is not practical. Therefore, in the present invention, the end-blocked polycaprolactone has a number average molecular weight of 600.
More than 20,000, preferably more than 700 and less than 10,000,
More preferably 700 or more and 5000 or less, still more preferably 700 or more and 2000 or less. In the present invention, the amount of terminal-blocked polycaprolactone (C) component added is 0.1 to 30 parts by weight per 100 parts by weight of thermoplastic polyester. If this amount is less than 0.1 part by weight, the effect of the addition will not be sufficient, and if it is more than 30 parts by weight, the effect will be saturated. This is undesirable as it causes loss of quality. A more preferable addition amount is 1 to
15 parts by weight. In the present invention, sodium antimonate used as component (D) has the effect of acting as a flame retardant auxiliary agent that promotes the flame retardancy of the organic bromine compound as component (E), which will be described later. The amount of sodium antimonate added is 0.1 to 20 parts by weight, preferably 1 to 15 parts by weight, as the amount of antimony element in sodium antimonate per 100 parts by weight of thermoplastic polyester. If this amount is less than 0.1 part by weight, the effect as a flame retardant aid will not be sufficiently expressed. Further, if the amount is more than 20 parts by weight, the flame retardant effect is saturated and not only does the effect not increase as compared to adding 20 parts by weight, but also the properties of the resulting resin composition deteriorate, which is not preferable. The organic bromine compound used as component (E) in the present invention has a chlorine atom or a bromine atom in its molecule and acts as a flame retardant for thermoplastic polyester. Compounds included. Such compounds include, for example, hexabromobenzene, pentabromotoluene, pentabromophenol, hexabromobiphenyl, decabromobiphenyl, tetrabromobutane, hexabromocyclododecane, decabromodiphenyl ether, octabromodiphenyl ether, hexabromobiphenyl, Bromodiphenyl ether, ethylene bis(tetrabromophthalimide), low molecular weight organic bromine compounds such as tetrabromobisphenol-A, brominated polycarbonates (e.g. brominated bisphenol-A),
Polycarbonate oligomers produced using A as a raw material), brominated epoxy compounds (for example, diepoxy compounds produced by the reaction of brominated bisphenol-A and epichlorohydrin, or obtained by the reaction of brominated phenols with epichlorohydrin) monoepoxy compounds), brominated polystyrene, poly(dibromophenylene oxide)
Examples include polymers and oligomers such as, and mixtures thereof. The amount of these organic bromine compounds added is 0.1 as the amount of bromine element per 100 parts by weight of thermoplastic polyester.
~30 parts by weight, preferably 1 to 15 parts by weight.
If the amount added is less than 0.1 part by weight, the flame retardance will not be sufficient, and if it exceeds 30 parts by weight, the physical properties of the composition will deteriorate significantly. Any compounding method can be used to obtain the flame retardant resin composition of the present invention. Generally, it is preferable to disperse these ingredients more uniformly, and there are various methods for homogenizing them by mixing all or some of them simultaneously or separately in a mixer such as a blender, kneader, roll, extruder, etc. A method can be used in which a portion of the components are mixed simultaneously or separately using, for example, a blender, kneader, roll, extruder, etc., and then the remaining components are mixed using these mixers or extruders to homogenize. The most common method is to homogenize a pre-dry blended composition by melt-kneading it in a heated extruder, extrude it into wires, and then cut it into desired lengths and granulate it. . The composition thus prepared is usually sufficiently dried and kept in a dry state before being charged into a hopper of a molding machine and subjected to molding. Other methods include, for example, a method in which other components are added or mixed during the production of the thermoplastic polyester, before the polycondensation, after the polycondensation, or during the polycondensation. In particular, when glass fiber is used as a filler, it should be melt-kneaded together with other components in an extruder in order to prevent its crushing as much as possible during kneading and to improve workability during composition production. For example, glass fiber-free polyester resin granules made in an extruder may be mixed with a predetermined amount of glass chopped strands or a pre-prepared glass fiber-rich thermoplastic resin. The resulting composition can also be charged into a molding machine hopper and subjected to molding. The flame-retardant resin composition of the present invention may further contain various additives for the purpose of improving other properties. For example, inorganic substances as nucleating agents that promote crystallization during molding and improve the molding cycle, such as alkaline earth metal carbonates (e.g. calcium carbonate, magnesium carbonate, etc.), sulfates (e.g. calcium sulfate, etc.), oxidized Metal oxides such as titanium, aluminum oxide, zinc oxide etc., talc, graphite, aluminum silicates, clays, metal salts of organic acids (e.g. stearates, benzoates,
salicylates, tartrates, montanates, terephthalates, etc.), alkaline earth metals or titanium,
Metal glycolates of germanium, antimony, tungsten, and manganese; α-olefin and α,
An ionic copolymer consisting of a β-unsaturated carboxylic acid salt can be added in an expressed amount. Further, flame retardants other than organic bromine compounds, such as red phosphorus and phosphorus compounds such as phosphonic acid amide, can also be added. Furthermore, for the purpose of improving heat resistance, antioxidants such as hindered phenol compounds and sulfur compounds, or heat stabilizers such as phosphorus compounds may be added. As the phosphorus compound added for this purpose, compounds represented by the following general formulas (i) and (ii) are particularly desirable.

【formula】

[Formula] [However, in the formula, X, Y and Z are hydrogen atoms, -
OR (where R is a hydrogen atom or a monovalent hydrocarbon group) or a monovalent hydrocarbon group. ] The monovalent hydrocarbon group in the above formula has 12 carbon atoms.
The following alkyl groups, aralkyl groups, aryl groups, etc. are preferred. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, cyclohexyl, octyl, decyl, etc., and examples of the aryl group include phenyl, naphthyl, methylphenyl, phenylphenyl, brominated phenyl, etc. Furthermore, benzyl is exemplified as aralkyl. Specific examples of phosphorus compounds include phosphoric acid, trimethyl phosphate, methyl diethyl phosphate, triethyl phosphate, triisopropyl phosphate, tributyl phosphate, triphenyl phosphate, and other phosphoric acid esters; phosphorous acid, phosphorous acid Phosphite esters such as trimethyl, triethyl phosphite, and triphenyl phosphite; phosphoric acid, phenylphosphonic acid,
Examples include phosufonic acids such as phenyl phenylphosphonate and derivatives thereof; phosufonic acids such as phosphinic acid, phenylphosphinic acid, and dimethylphosphinic acid and derivatives thereof. Among these, particularly desirable are ()phosphorous acid esters such as trimethyl phosphate and triphenyl ()phosphorous acid. These phosphorus compounds can be used alone or in combination of two or more. Furthermore, various epoxy compounds may be added for the purpose of improving melt viscosity stability and hydrolyzability. Examples of epoxy compounds include bisphenol A type epoxy compounds obtained by reacting bisphenol A and epichlorohydrin, aliphatic glycidyl ethers obtained by reacting various glycols or glycerol with epichlorohydrin, and novolac type epoxy compounds obtained from novolac resins and epichlorohydrin. Preferable epoxy compounds are alicyclic compound-type epoxy compounds obtained from compounds and alicyclic compounds, and particularly preferable epoxy compounds include bisphenol A-type epoxy compounds, diglycidyl ethers of low molecular weight polyethylene glycol, and diglycidyl esters of aromatic dicarboxylic acids. etc. Examples of other additives include ultraviolet absorbers, colorants, lubricants, antistatic agents, and foaming agents. Also, in small proportions, other thermoplastic resins such as sterol resins, acrylic resins, polyethylene, polypropylene, fluorine resins, polyamide resins, polycarbonate resins, polysulfones, etc.; thermosetting resins such as phenolic resins, melamine resins, unsaturated polyester resins , silicone resins, etc.; and soft thermoplastic resins such as ethylene-vinyl acetate copolymers, polyester elastomers, etc. may also be added. The flame-retardant resin composition of the present invention can be easily molded by a conventional method using a general thermoplastic resin molding machine. Hereinafter, the present invention will be explained in detail with reference to Examples. In addition, the intrinsic viscosity of the thermoplastic polyester described in the examples is a value measured at 35° C. in an orthochlorophenol solution. Furthermore, parts refer to parts by weight. Various properties in the examples were measured by the following methods. (1) Static strength: Tensile test... Based on ASTMD-638. Impact strength: Compliant with ASTMD-256. (Thickness: 1/8" without notch) (2) Flammability: Conforms to American Underwriters Laboratories standard Subject 94 (UL-94). Test piece: 5" long x 1/2' wide x 1 thick /16" was molded by injection molding. Examples 1 to 4 and Comparative Examples 1 to 8 Glass fibers with a fiber length of 3 mm were added to polyethylene terephthalate with an intrinsic viscosity of 0.71, which had been dried at 140°C for 5 hours. Puto Strand (Nittobo Co., Ltd. brand 3PF−)
231), talc as a crystal nucleating agent, decabromodiphenyl ether as a flame retardant (Mitsui Toatsu Planeron),
DB-100), end-capped polycaprolactone as a plasticizer, triphenyl phosphate as a stabilizer, and sodium antimonate or antimony trioxide in the proportions shown in Table 1.
The mixture was mixed uniformly using a mold blender. The resulting mixture was melt-mixed in a 65 mm diameter single screw extruder at a barrel temperature of 270°C, and the thread discharged from the die was cooled and cut to obtain pellets for molding. Next, after drying the pellets with hot air at 140°C for 5 hours, a test piece mold for measuring physical properties was attached to a 5-ounce injection molding machine, and the cylinder temperature was set at 260°C.
Mold temperature 70℃, injection pressure 800Kg/cm ² , cooling time 20
The test pieces were molded under molding conditions of 35 seconds and a total cycle time of 35 seconds. The properties of the molded article thus obtained are shown in Table-1. The end-blocked polycaprolactone used here was a mixture of 100 parts of commercially available polycaprolactone whose end group is a hydroxyl group (Daicel Corporation: trade name Plaxel #212, number average molecular weight 1200), 80 parts of methyl benzoate, and tributyl titanate. 0.002 part was added, heated to 190 to 210°C, and allowed to react with stirring for 10 hours while removing methanol distilled from the reaction, and then further removing excess methyl benzoate under reduced pressure. Obtained. The hydroxyl value of this end-blocked polycaprolactone was 1.7 as measured in accordance with JIS-K-1557.

[Table] Example 5 and Comparative Example 9 The compositions of Example 4 and Comparative Example 4 were used except that the molding was performed at a cylinder temperature of 280°C.
Molded under exactly the same conditions as Example 4 and Comparative Example 4,
The properties of the molded product were measured. The results are shown in Table-2.

[Table] From this result, although the molded product properties of Example 5 are slightly lower than those of Example 4, Comparative Example 9
When compared with Comparative Example 4, it can be seen that the limiting viscosity and the static strength significantly decreased. This shows that antimony trioxide has a very negative effect on the thermal stability of polyethylene terephthalate. Furthermore, the flame retardance of Comparative Example 9 was V- due to the molten resin dripping during the combustion test and igniting the cotton. Example 6 and Comparative Example 10 Molding pellets were obtained in the same manner as in Example 1,
After drying this pellet at 140℃ for 5 hours,
Using a nozzle with a diameter of 1 mm and a length of 10 mm in a Koka type flow tester (manufactured by Shimadzu Corporation), the melt viscosity was determined after residence at 280°C for 5 minutes, 10 minutes, and 15 minutes. The results are shown in Table 3.

[Table] Looking at the melt viscosity due to retention according to Example 6 and Comparative Example 10, Sb ₂ O ₃ has a large viscosity decrease, but sodium antimonate has a small viscosity decrease,
It was found that the melt thermal stability was improved.

Claims (1)

[Scope of Claims] 1 (A) per 100 parts by weight of thermoplastic polyester, (B) 0 to 200 parts by weight of filler, (C) 0.1 to 30 parts by weight of end-blocked polycaprolactone, (D) Sodium antimonate. 0.1 to 20 parts by weight as antiomone element amount, and 0.1 to 30 parts as bromine element amount of (E) organic bromine compound
A flame-retardant resin composition containing parts by weight. 2. The flame-retardant resin composition according to claim 1, wherein the thermoplastic polyester is polyethylene terephthalate. 3 End-capped polycaprolactone has the general formula [R ¹² CO(-O(-CH ₂ )- ₅ CO)- _o O]- _n R ¹¹ -[
−CO(−CO(−O(−CH ₂ )− ₅ CO)− _o ′OR ¹³ ] _n ′ [However, in the formula, R ¹¹ is an (m+m′)-valent organic group,
R ¹² and R ¹³ are each a monovalent organic group, n and n' are each a number of 2 or more, m and m' are each a number of 0 to 4, and (m+m') is 1 or more. ] The flame-retardant resin composition according to claim 1, which is an end-capped polycaprolactone represented by the following formula and having a number average molecular weight of 600 or more and 20,000 or less.