JP2000044781A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin compsn. which is excellent in flame retardance and electric insulation properties represented by tracking resistance by compounding (A) an arom. polyester, (B) red phosphorus and/or an org. phosphorus compd., and (C) calcium borate in a specified ratio. SOLUTION: One hundred pts.wt. ingredient A is compounded with 1-20 pts.wt. (in terms of phosphorus) ingredient B and 2-50 pts.wt. ingredient C. Ingredient A is a polyester formed from an arom. dicarboxylic acid and an aliph. diol and pref. has an intrinsic viscosity of 0.6-1.2, examples being polytetramethylene terephthalate and polytetramethylene 2,6- naphthalenedicarboxylate. Red phosphorus, having a higher heat resistance, or a phosphoric ester having an arom. ring is pref. as ingredient B. Red phosphorus is used pref. in the form of a powder (an average particle size of 5-40 μm) coated with a curable resin. An example of ingredient C is 2CaO.3B2O3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin composition,
More specifically, it relates to an aromatic polyester resin composition having excellent flame retardancy and electrical insulation.

[0002]

2. Description of the Related Art Engineering plastics are used in various applications due to their excellent mechanical properties, heat resistance and moldability, and their use in automotive parts, mechanical parts and electric and electronic parts is expanding.

[0003] In the field of electric and electronic parts, while parts are becoming lighter and thinner and smaller and higher in performance, safety in use, productivity, utilization of recycled resources, and the like are required. Its applications are expanding mainly on aromatic polyester resins, which are excellent in properties, moldability and chemical resistance, and are relatively easy to be flame retarded.

When an aromatic polyester resin is used for electric and electronic parts, it is often flame-retarded by an organic halogen compound, and the safety of the product against fire is enhanced. However, the tracking resistance, which is one measure of the electrical insulation, is notably reduced due to the flame retardation caused by the organic halogenated compound, although the aromatic polyester resin itself has good properties. However, there is a problem that the risk of fire from another aspect increases.

[0005] Therefore, there is a strong demand for an aromatic polyester resin having both electric resistance and flame retardancy and tracking resistance.

[0006] Regarding flame retardancy, see Japanese Patent Laid-Open No. 6-145504.
In Japanese Patent Application Laid-Open Publication No. H11-163, there is disclosed a technique in which red phosphorus and a zinc compound such as zinc borate are blended with a polyamide resin. Both the aromatic polyester resin and the polyamide resin are engineering plastics, but the polyamide resin inherently has excellent tracking resistance, but has large changes in electrical and mechanical properties due to moisture absorption.

Further, it is known that the interaction between a phosphorus atom and a nitrogen atom in the polymer skeleton of the polyamide resin enhances the flame-retardant effect of the polyamide resin, and is disclosed in JP-A-6-145504. Incorporation of phosphorus compounds has also been widely practiced.

However, since the aromatic polyester resin does not have the interaction as in the case of the polyamide resin, it is generally difficult to make it flame-retardant as compared with the polyamide resin. It is necessary to mix many phosphorus compounds. However, a large amount of the phosphorus compound added to the polyester resin causes not only a decrease in tracking resistance but also a decrease in mechanical properties and moldability.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a polyester resin composition having excellent flame retardancy and electrical insulation. In particular, it is an object of the present invention to provide a flame-retardant polyester resin composition which can be suitably used in electric / electronic component applications, has no change in properties due to moisture absorption, and has high electrical insulation properties represented by tracking resistance.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to obtain a polyester resin composition having excellent flame retardancy and electrical insulation properties. As a result, the aromatic polyester was identified as red phosphorus and / or a phosphorus compound. It has been found that a composition containing a specific amount of the metal compound of the present invention solves the above-mentioned problems, and has reached the present invention.

That is, the present invention provides (A) 100 parts by weight of an aromatic polyester, (B) 1 to 20 parts by weight of a red phosphorus and / or an organic phosphorus compound as a phosphorus atom content,
And (C) a resin composition comprising 2 to 50 parts by weight of calcium borate.

Hereinafter, the present invention will be described in detail. The aromatic polyester (A) used in the present invention is a polyester containing an aromatic dicarboxylic acid as a dicarboxylic acid component and an aliphatic diol as a diol component.

Terephthalic acid as a dicarboxylic acid component;
Isophthalic acid, phthalic acid; phthalic acid derivatives such as methyl terephthalic acid and methyl isophthalic acid; 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid,
Examples thereof include naphthalenedicarboxylic acids such as 5-naphthalenedicarboxylic acid and derivatives thereof.

Examples of the diol component include aliphatic diols such as ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, and neopentyl glycol.

As the aromatic polyester (A), polytetramethylene terephthalate and polyethylene-2,
6-Naphthalenedicarboxylate is preferred because of its excellent heat resistance, chemical resistance, and moldability.

The aromatic polyester (A) is substituted with, for example, 40 mol% or less, preferably 30 mol% or less, more preferably 20 mol% or less of a copolymer component based on all dicarboxylic acid components or all diol components. It may be something.

As the copolymerization component, of the above-mentioned dicarboxylic acids and diols, components other than the components used as the main components can be used. Further, as the dicarboxylic acid component, isophthalic acid, phthalic acid, methyl terephthalic acid; phthalic acid derivatives such as methyl isophthalic acid;
Naphthalenedicarboxylic acids such as -naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid and derivatives thereof;
Diphenylcarboxylic acids such as 4,4'-diphenyldicarboxylic acid and 3,4'-diphenyldicarboxylic acid and derivatives thereof; 4,4'-diphenoxymethanedicarboxylic acid;
Aromatic dicarboxylic acids such as 4,4'-diphenoxyethane dicarboxylic acid; aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid and decane dicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid. Examples of the diol component include 1,4
Alicyclic diols such as cyclohexanedimethanol; dihydroxybenzenes and derivatives thereof such as hydroquinone and resorcin; bisphenols such as 2,2-bis (4-hydroxyphenyl) propane and 2,2-bis (4-hydroxyphenyl) sulfone Compounds: Examples include aromatic diols such as ether diols obtained from bisphenol compounds and glycols such as ethylene glycol. In addition, oxycarboxylic acid can be copolymerized, and examples of oxycarboxylic acid include ε-oxycaproic acid, hydroxybenzoic acid, and hydroxyethoxybenzoic acid.

A branched component may be copolymerized in the aromatic polyester (A). As a branching component, for example, an acid having a trifunctional or tetrafunctional ester forming ability such as tricarballylic acid, trimesic acid, and trimellitic acid; a trifunctional or tetrafunctional ester forming ability such as glycerin, trimethylolpropane, and pentaerythritol Can be exemplified. When the branched component is copolymerized, the copolymerization amount is 1.0 mol% of the total dicarboxylic acid component.
Or less, preferably 0.5 mol% or less, more preferably 0.30 mol% or less.

The aromatic polyester (A) may be used in combination of two or more kinds.

The aromatic polyester (A) has an intrinsic viscosity of 0.5 or more when measured at 35 ° C. using o-chlorophenol, and has an intrinsic viscosity of 0.6 to 1.2. Those are preferred in terms of balance between mechanical properties and moldability.

The aromatic polyester used in the present invention can be produced by a usual production method, for example, a melt polycondensation reaction or a method combining this with a solid phase polycondensation reaction.

The method for producing polytetramethylene terephthalate will be described as an example. Terephthalic acid or an ester-forming derivative thereof (eg, a lower alkyl ester such as dimethyl ester or monomethyl ester) and tetramethylene glycol or an ester-forming derivative thereof Is subjected to a heat reaction in the presence of a catalyst to obtain a glycol ester of terephthalic acid, and polytetramethylene terephthalate can be produced by a method of subjecting this to a predetermined polymerization degree in the presence of the catalyst.

In the present invention, red phosphorus and / or
Alternatively, an organic phosphorus compound is used as a compound for flame retardation. Since the processing temperature of the aromatic polyester is relatively high, as the component (B), red phosphorus having higher heat resistance or a phosphate compound containing an aromatic ring is preferable, and red phosphorus having no bleed-out in the composition. Is particularly preferred.

When red phosphorus is used as the component (B), red phosphorus alone is liable to ignite or generate phosphine due to high temperature or mechanical shock, and is used in the form of a powder coated with a curable resin. Is preferred. The curable resin used for coating red phosphorus is preferably at least one of a phenol resin, an epoxy resin, an unsaturated polyester resin, a melamine resin, a urea resin, an aniline resin, and a silicone resin.

The red phosphorus coated with the curable resin includes:
Further, in the curable resin used for the coating, aluminum hydroxide, magnesium hydroxide, zinc hydroxide, and at least one inorganic compound selected from the group consisting of hydroxides of titanium may be dispersedly contained, Further, at least one kind of film selected from aluminum hydroxide, magnesium hydroxide, zinc hydroxide, and a hydroxide of titanium may be further provided in contact with red phosphorus under the film of the curable resin. .

The red phosphorus powder coated with the curable resin is
Preferably 5 to 40 μm, more preferably 25 to 35 μm
The average particle size in the range of m.

Powdered red phosphorus coated with a curable resin is significantly improved in handling and safety as compared with red phosphorus alone. However, when used, thermoplastic resin is used to further improve safety. It is preferably used as master pellets which have been previously melt-kneaded.

As the thermoplastic resin in this case, for example, polyethylene, polypropylene, EPDM, ethylene-
Ethyl acrylate, ethylene-methyl acrylate,
Examples include polyester, polyamide, and polycarbonate. Usually, an aromatic polyester used as the component (A) is desirable.

The compounding amount of the red phosphorus and / or organic phosphorus compound as the component (B) is 1 to 20 parts by weight as a phosphorus atom content per 100 parts by weight of the aromatic polyester (A). If the amount is less than 1 part by weight, the obtained flame retardant effect is small, and if it is more than 20 parts by weight, the mechanical properties of the resin composition are inferior.

The component (C) of the present invention is calcium borate, for example, 2CaO.3B ₂ O ₃ . Also, the calcium borate may be those water molecules hydrated, calcium borate pentahydrate _{(2CaO · 3B 2 O 3 ·} 5H 2 O)
Etc. are exemplified.

Flame retardancy can be imparted to the aromatic polyester by blending it with a red phosphorus and / or organic phosphorus compound. By further blending calcium borate, the flame retardant effect can be further enhanced. Not only can it be achieved, but also the tracking resistance can be improved, and the effect is a synergistic effect that cannot be expected from the effect when each component is blended alone.

The amount of the calcium borate of the component (C) is
It is 2 to 50 parts by weight per 100 parts by weight of the aromatic polyester. If the amount is less than 2 parts by weight, the synergistic effect in flame retardancy and tracking resistance obtained is small, and if it is more than 50 parts by weight, the mechanical properties of the resin composition are inferior.

In the present invention, it is preferable to add an inorganic filler (D). The inorganic filler (D) is used as a total amount of the component (C) and the component (D), and the total amount of the inorganic filler is 25 to 60.
% By weight, preferably 30 to 55% by weight,
The flame retarding efficiency by the components (B) and (C) is enhanced and effective. If the total amount of the components (C) and (D) is less than 25% by weight, the effect is not sufficiently exhibited.
Exceeding the weight percent is not preferred because the mechanical properties and fluidity of the composition are inferior.

As the inorganic filler of the component (D) in the present invention, fibrous, whisker-like, granular, plate-like and amorphous fillers can be used.
Carbon fiber, steel fiber, asbestos, ceramic fiber, potassium titanate whisker, boron whisker,
Reinforcing materials such as aluminum borate; silicate-based fillers such as kaolin, clay, wollastonite, talc, mica; magnesium hydroxide, cobalt hydroxide, calcium carbonate;
Metal compounds other than calcium borate such as barium sulfate; fillers such as silica, alumina, glass beads, and glass flakes can be exemplified. Among these, a fibrous inorganic filler capable of obtaining a reinforcing effect in mechanical properties is preferable, and glass fiber is particularly preferable. These inorganic fillers may be used in combination of two or more.

The resin composition of the present invention has an electric insulating property,
As relative tracking index (CTI) of IEC standard,
It can have a tracking resistance of 500 V or more, has excellent flame retardancy, and has a flame retardancy of 25 or more in oxygen index. The resin composition of the present invention can have both such tracking resistance and flame retardancy at the same time.

To the resin composition of the present invention, if necessary, a compounding agent such as a stabilizer, a coloring agent, a lubricant, an ultraviolet absorber, an antistatic agent and a pigment may be added in an effective amount.

Other flame retardants may be added. Examples of the flame retardants include brominated polystyrene, brominated polyphenylene ether, brominated bisphenol A type epoxy resin, brominated acrylic resin, and brominated bisphenol-A-.
Examples include diglycidyl ethers and oligomers thereof, polycarbonate oligomers produced from brominated bisphenol-A, brominated biphenyl ethers, brominated diphthalimide compounds, and halogen-containing compounds such as dimers of chlorinated hexapentadiene. it can.

A flame retardant aid may be added. Examples of the flame retardant aid include antimony compounds such as antimony trioxide and sodium antimonate; metal oxides such as iron oxide; and triazine compounds such as melamine cyanurate. Examples can be given. The flame retardant and the flame retardant auxiliary may be used alone or in combination.

When the flame retardant and the flame retardant auxiliary are blended, the amount of the flame retardant and the flame retardant auxiliary should be in a range that can suppress the decrease in the tracking resistance.

Further, in order to further enhance the effect of the flame retardant,
You may mix | blend the compound which suppresses the dripping of the molten particle at the time of combustion. As such a compound, polytetrafluoroethylene, fumed colloidal silica, and the like produced by emulsion polymerization are known.

Further, for the purpose of improving heat resistance, an antioxidant such as a hindered phenol compound, an aromatic amine compound, an organic phosphorus compound and a sulfur compound or a heat stabilizer can be added.

Various epoxy compounds, oxazoline compounds and the like may be added for the purpose of improving melt viscosity stability and hydrolysis resistance. As the epoxy compound, for example, bisphenol-A type epoxy compound obtained by reacting bisphenol-A with epichlorohydrin, aliphatic glycidyl ether obtained from the reaction of various glycols and glycerol with epichlorohydrin, novolak type epoxy compound, aromatic or Aliphatic carboxylic acid type epoxy compounds and alicyclic compound type epoxy compounds are preferred. As the oxazoline compound, aromatic or aliphatic bisoxazolines, particularly 2,2′-bis (2-oxazoline) and 2,2′-m-phenylenebis (2-oxazoline) are preferred.

Other thermoplastic resins and thermosetting resins can be blended as long as the features of the present invention are not lost. As a thermoplastic resin, for example, aliphatic polyester resin, polyamide resin, polyphenylene sulfide resin, polyphenylene ether resin, polycarbonate resin, phenoxy resin, polyethylene and its copolymer, polypropylene and its copolymer, polystyrene and its copolymer, acrylic Examples thereof include resins, fluororesins, acrylic copolymers, polyamide elastomers, and polyester elastomers. Examples of the thermosetting resin include a phenol resin, a melamine resin, an unsaturated polyester resin, and a silicone resin.

In the resin composition of the present invention, it is preferable that these components are uniformly dispersed. Any method can be used as a compounding method. For example, all or a part of the compounded components are supplied to a heated single-screw, twin-screw extruder or the like in a lump or in a divided manner, homogenized by melt kneading, extruded into a wire shape, and the extruded molten resin is cooled and solidified. Then, a method of cutting into a desired length and granulating can be used. A method using another blender such as a blender, a kneader, and a roll may be used. In addition, a method of sequentially adding the components by using these in combination or repeating a plurality of times can be used.

In order to obtain a resin molded product from the resin composition thus obtained, the resin composition is usually supplied to a molding machine such as an injection molding machine while keeping the resin composition in a sufficiently dried state. Further, it is also possible to dry blend the constituent materials of the resin composition, directly charge them into a hopper of a molding machine and melt-knead them in a molding machine.

[0046]

The present invention will be described below in detail with reference to examples. In addition, the measurement of various characteristics in an Example was based on the following method. (1) Mechanical properties: Tensile test conforms to ASTM D638,
Bending test conforms to ASTM D790. (2) Deflection temperature under load (DTUL): ASTM D64
8 compliant. (3) Oxygen index: based on JIS K7201. (4) Tracking resistance: IEC standard Publ. 11
2 According to the second edition, the relative tracking index (CT
Measure I). (5) Intrinsic viscosity number: Measured at 35 ° C. with an Ostwald viscometer using o-chlorophenol as a solvent.

[Examples 1 and 2 and Comparative Examples 1 to 5] 13
Polytetramethylene terephthalate (PBT) resin having an intrinsic viscosity of 0.88 (manufactured by Teijin Limited) dried with hot air at 0 ° C. for 8 hours, glass fiber (fiber diameter 13 μm, length 3 mm)
Chopped strands, manufactured by Nippon Electric Glass Co., Ltd.), red phosphorus powder (Nova Excel 140, manufactured by Rin Kagaku Kogyo Co., Ltd.) surface-coated with a phenol resin and aluminum hydroxide, calcium borate pentahydrate ( 2CaO.3
_{B 2 O 3 · 5H 2 O} : UB powder at a ratio shown KINSEI MATEC Co., Ltd. Ltd.) Table 1, uniformly after mixing, using a vented twin-screw extruder having a screw径各44mm in advance tumbler Cylinder temperature 2 while pulling vacuum
50 ° C, screw rotation speed 120 rpm, discharge amount 50k
The mixture was melt-kneaded at g / hr, and the thread discharged from the die was cooled and cut to obtain molding pellets.

Next, each of the pellets was measured in an injection molding machine having an injection capacity of 5 oz under the conditions of a cylinder temperature of 250 ° C., a mold temperature of 80 ° C., an injection pressure of 80 MPa, a cooling time of 12 seconds and a total molding cycle of 40 seconds. Molded articles were formed.

Each characteristic was measured using these molded articles. Table 1 shows the results. However, in Table 1, each composition is expressed in terms of parts by weight, and the ratio to the total amount of the composition is also indicated in parentheses in units of weight%.

[0050]

[Table 1]

As can be seen from the results in Table 1, when the PBT resin was made flame-retardant with red phosphorus, its tracking resistance did not show a high value (Comparative Examples 2 to 4). Further, only by adding calcium borate to the PBT resin, sufficient flame retardancy was not exhibited (Comparative Example 5). However, when red phosphorus and calcium borate are used in combination in a PBT resin, flame retardancy and tracking resistance are improved due to a synergistic effect that cannot be estimated from the compounding effects of each, and heat resistance (DTUL) and mechanical properties are improved. A composition having excellent properties was obtained (Examples 1 and 2).

[0052]

According to the present invention, it is possible to obtain a resin composition having excellent electrical insulation properties represented by flame retardancy and tracking resistance. The resin composition of the present invention can be suitably used for electric / electronic parts.

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Claims (7)

[Claims] (A) 100 parts by weight of an aromatic polyester, (B) 1 to 20 parts by weight of a phosphorus atom and / or an organic phosphorus compound as a phosphorus atom content, and (C) 2 to 50 parts by weight of calcium borate. Resin composition. 2. (A) 100 parts by weight of an aromatic polyester, (B) 1 to 20 parts by weight of a red phosphorus and / or an organic phosphorus compound as a phosphorus atom content, (C) 2 to 50 parts by weight of calcium borate, and (D) A resin composition comprising an inorganic filler, wherein the total of the components (C) and (D) is 25 to 60% by weight of the total amount of the composition. 3. The resin composition according to claim 1, wherein the component (A) is polytetramethylene terephthalate. 4. The composition according to claim 1, wherein the component (A) is polytetramethylene-2,
3. The resin composition according to claim 1, which is 6-naphthalenedicarboxylate. 5. The resin composition according to claim 1, wherein the component (B) is powdery red phosphorus coated with a curable resin. 6. The resin composition according to claim 1, wherein the component (C) is a hydrate of calcium borate. 7. The component (D) is a fibrous inorganic filler.
The resin composition according to claim 1.