JPH1067926A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a PBT resin composition having tracking resistance, particularly tracking resistance enough to withstand domestic and foreign domestic voltages, and having good flame retardancy. SOLUTION: (A) Polybutylene terephthalate 29
~ 58% by weight, (B) brominated polyacrylate 6 ~ 14
% By weight, (C) 3 to 7% by weight of sodium antimonate,
(D) 3 to 10% by weight of polyolefin, and (E) 30 to 40% by weight of the total amount of the metal silicate filler and glass fiber, and in the total amount of the metal silicate filler and glass fiber. A resin composition wherein the ratio of the metal silicate filler to 100% by weight is 15 to 65% by weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polybutylene terephthalate resin composition, and more particularly to a polybutylene terephthalate resin composition exhibiting excellent flame retardancy and electrical properties.

[0002]

2. Description of the Related Art Polybutylene terephthalate (hereinafter, referred to as polybutylene terephthalate)
Resin may be referred to as “PBT”), which has excellent heat resistance,
As a resin having mechanical properties, electrical properties, moldability, and chemical resistance, it has been widely used in electric / electronic parts, automobile parts, mechanical parts, and the like.

In recent years, home electric appliances, audio, A
As electrical products such as V equipment are required to be smaller and have higher performance, electrical and electronic components are becoming lighter, thinner and smaller, having higher performance and higher density. It is also necessary to ensure fire safety. Therefore,
For thermoplastic resins used for electric and electronic parts,
Electrical insulation such as higher flame retardancy and tracking resistance,
Further, there is a demand for a material that does not generate substances that impair the performance of electric / electronic parts.

[0004] PBT resin itself is a resin having excellent tracking resistance, but for electric and electronic parts, flame retardant is generally used by using a combination of a bromine flame retardant and an antimony oxide flame retardant auxiliary. Since the tracking resistance is greatly impaired by the addition of a flame retardant and a flame retardant aid, red phosphorus (JP-A-54-8643) is used as the flame retardant.
), Cyanuric acid salts of melamine (Japanese Unexamined Patent Publication No.
No. 112958), and as the flame retardant auxiliary, sodium antimonate having a smaller decrease in tracking resistance is used (Japanese Patent Application Laid-Open Nos. 51-44154 and 51-154).
Many attempts have been made to suppress a decrease in tracking resistance. However, it was difficult to make them highly flame-retardant while maintaining mechanical properties and the like.

A combination of a bromine flame retardant and an antimony oxide flame retardant generates a corrosive compound such as hydrogen bromide from a molten state or a molded product. At times, a phenomenon of corroding metal parts also occurs.

As a means for improving the tracking resistance of a resin, a method of blending a metal silicate filler represented by talc or the like (JP-A-48-66652, 51-46).
344, 51-80351, 52-58752, 51-
127149, 53-94531, etc.) and a method of blending polyolefins (Japanese Patent Application Laid-Open No. 51-11685).
4, JP-A-6-228411, 7-188529, etc.), however, there are problems such as the compounding of the filler lowering the mechanical strength and moldability, and the compounding of the polyolefins impairing the appearance of the molded product. Was.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide tracking resistance, in particular, tracking resistance sufficient to withstand domestic and foreign household voltages, and to provide good tracking resistance. An object of the present invention is to obtain a PBT resin composition having excellent flame retardancy.

[0008]

The present inventors have conducted intensive studies to obtain a PBT resin having both high flame retardancy and excellent tracking resistance, and as a result, a flame retardant and a flame retardant auxiliary agent specific to the PBT resin have been obtained. It has been found that the above-mentioned object is achieved by blending a specific amount of a polyolefin, a metal silicate filler and a glass fiber in a specific ratio.

That is, the present invention relates to (A) 29 to 58% by weight of polybutylene terephthalate, (B) 6 to 14% by weight of brominated polyacrylate, (C) 3 to 7% by weight of sodium antimonate, and (D) polyolefin. 3 to 10% by weight, and (E) a total amount of 30 to 40% by weight of the metal silicate filler (E1) and the glass fiber (E2), and the metal silicate filler (E1) Glass fiber (E
2) weight ratio (E1) :( E2) = 15: 85-6
The resin composition is in the range of 5:35.

The present invention will be described. Component (A) used in the present invention, polybutylene terephthalate (PBT)
Is mainly intended for a polyester whose acid component is terephthalic acid and whose diol component is tetramethylene glycol.

The PBT may be partially substituted with a copolymer component. In that case, it is necessary that terephthalic acid and tetramethylene glycol are present in an amount of 80 mol% or more based on the total acid component and the total glycol component, respectively.

The copolymerizable components include phthalic acid derivatives such as isophthalic acid, phthalic acid, methyl terephthalic acid and methyl isophthalic acid; 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5- Naphthalenedicarboxylic acids such as naphthalenedicarboxylic acid and derivatives thereof; 4,4′-diphenyldicarboxylic acid,
Diphenylcarboxylic acids such as 4′-diphenyldicarboxylic acid and derivatives thereof; 4,4′-diphenoxymethanedicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, 4,4′-diphenylketonedicarboxylic acid,
Aromatic dicarboxylic acids such as 4'-diphenylsulfone dicarboxylic acid and 4,4'-diphenyl ether dicarboxylic acid; aliphatic or alicyclic aliphatic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, cyclohexanedicarboxylic acid Dicarboxylic acid; ethylene glycol, propylene glycol, hexamethylene glycol, octamethylene glycol, neopentyl glycol, diethylene glycol, polyethylene glycol,
Aliphatic diols such as polypropylene glycol; 1,4
Alicyclic diols such as cyclohexanedimethanol; dihydroxybenzenes and derivatives thereof such as hydroquinone and resorcin; aromatic diols such as 4,4'-dihydroxydiphenyl; 2,2-bis (4-hydroxyphenyl) propane; Bisphenol compounds such as 2-bis (4-hydroxyphenyl) sulfone; aromatic diols such as ether diols obtained from bisphenol compounds and glycols such as ethylene glycol;

Also, oxycarboxylic acid components such as oxybenzoic acid, hydroxynaphthoic acid, hydroxydiphenylcarboxylic acid, and ω-hydroxycaproic acid can be copolymerized.

Further, a compound having three or more functional groups, for example, glycerin, pentaerythritol, trimellitic acid, pyromellitic acid and the like may be copolymerized as long as the polyester does not substantially lose moldability.

The limiting viscosity number of PBT used in the present invention can be 0.5 or more when measured at 35 ° C. using o-chlorophenol.
Those having an intrinsic viscosity of ~ 1.2 are preferred. When the intrinsic viscosity is less than 0.6, the mechanical properties of the obtained resin composition are inferior, and when it is more than 1.2, the fluidity of the resin composition during molding is inferior.

The PBT used in the present invention can be produced by a usual method for producing polyester, for example, a melt polycondensation reaction or a method combining this with a solid phase polycondensation reaction. For example, terephthalic acid or an ester-forming derivative thereof (for example, a lower alkyl ester such as dimethyl ester or monomethyl ester) and tetramethylene glycol or an ester-forming derivative thereof are reacted in the presence of a catalyst.
PBT can be produced by a method in which a reaction is carried out by heating and the resulting glycol ester of terephthalic acid is polymerized to a predetermined degree of polymerization in the presence of a catalyst.

The brominated polyacrylate as the component (B) used in the present invention is obtained by polymerizing brominated benzyl acrylate or brominated benzyl methacrylate alone, or by copolymerizing two or more kinds or copolymerizing with other vinyl monomers. It is a polymer obtained by polymerizing. Specific examples of the brominated polyacrylate include polypentabromobenzyl acrylate, polytetrabromobenzyl acrylate, polytribromobenzyl acrylate,
And polypentabromobenzyl methacrylate.

The vinyl monomers copolymerizable with the brominated polyacrylate include acrylic acid esters such as acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate and benzyl acrylate;
Methacrylic acid esters such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and benzyl methacrylate; styrene, acrylonitrile, fumaric acid, unsaturated carboxylic acids such as maleic acid or anhydrides thereof, vinyl acetate, vinyl chloride and the like. . The copolymerization ratio of these is preferably 40 mol% or less.
If the copolymerization ratio exceeds 40 mol%, the efficiency of flame retardation of the PBT resin is reduced, and the mechanical properties are lowered due to excessive blending.

The degree of polymerization of the brominated polyacrylate is not particularly limited, but is preferably from 10 to 10 from the viewpoint of extrudability and fluidity.
500 are preferred.

The compounding amount of the brominated polyacrylate of the component (B) is 6 to 14% by weight based on the whole composition. If the amount is less than 6% by weight, the flame retarding effect of the composition is not sufficient, and if it is more than 14% by weight, the fluidity and mechanical properties of the composition are undesirably reduced.

The component (C) sodium antimonate used in the present invention functions to enhance the flame retardancy of the PBT resin by a synergistic effect with the component (B) brominated polyacrylate, and (NaO) p・ (Sb ₂ O ₅ ) ・
_{qH 2 O (p = 0.1~1,} q = 0~4) is a sodium salt of antimony pentoxide represented by. The particle size is not particularly limited, but is preferably from 0.02 to 5 μm.

The sodium antimonate can be surface-treated with an epoxy compound, a silane compound, an isocyanate compound, a titanate compound or the like, if necessary.

The compounding amount of the antimony-based flame retardant auxiliary of the component (C) is 3 to 7% by weight in the whole composition. If the amount is less than 3% by weight, the effect of improving flame retardancy is small,
On the other hand, if the content is more than 7% by weight, not only is no effect expected to be increased by further compounding, but also the moldability such as mechanical properties and fluidity of the PBT resin is inferior.

When a PBT resin is made flame-retardant, a high-molecular bromine-based flame retardant and an antimony oxide-based flame retardant, which are generally used for making a PBT resin flame-retardant, such as brominated polycarbonate and brominated epoxy, are used. Then, the tracking resistance of the PBT resin generally greatly decreases. However, when the brominated polyacrylate and sodium antimonate are made flame-retardant, this decrease in tracking resistance is significantly suppressed. Attempts to suppress this decrease in tracking resistance using sodium antimonate are disclosed in JP-A-51-44.
154, 51-80351 and the like, but they do not mention the effect of combination with a specific brominated flame retardant.

When the brominated polyacrylate is blended with antimony trioxide, which is a commonly used flame retardant, the reaction between the brominated polyacrylate and PBT is promoted. There is also an advantage that the reaction hardly occurs. Further, the combination of the brominated polyacrylate and sodium antimonate also has the effect of significantly reducing the amount of bromine generated from the brominated flame retardant.

That is, the flame retardancy of the PBT resin by the combination of the brominated polyacrylate and sodium antimonate not only has excellent tracking resistance, but also suppresses the reaction between the brominated polyacrylate and the PBT, and furthermore, the generation of bromine. Many effects that cannot be obtained with other combinations that are less than the above are simultaneously exhibited, and are very useful industrially.

The polyolefin of the component (D) used in the present invention is ethylene, propylene, 1-butene,
Methyl-1-butene, 1-pentene, 4-methyl-1-
One or more polymers of α-olefins such as pentene, 1-hexene and 5-methyl-1-hexene, or a mixture of two or more of these polymers.

The polyolefin may be further copolymerized with other copolymerizable other monomer components. Examples of the copolymerizable component include a diene compound, an α, β-unsaturated carboxylic acid derivative, a styrene compound, and a vinyl acetate derivative. Of these, the α, β-unsaturated compound is preferred because of its compatibility with the PBT resin. Saturated carboxylic acid derivatives are particularly preferred.
Examples of α, β-unsaturated carboxylic acid derivatives include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methylfumaric acid, mesaconic acid, citraconic acid, glutaconic acid, acrylic Methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, Examples include dimethyl itaconate, sodium methacrylate, potassium methacrylate, magnesium methacrylate, zinc acrylate, maleic anhydride, itaconic anhydride, citraconic anhydride, glycidyl acrylate, and glycidyl methacrylate. The range in which these are copolymerized is preferably 40 mol% or less.

The viscosity of the polyolefin of the component (D) used in the present invention is determined by the melt flow rate (MFR, JIS).
K7210, 250 ° C., 2.16 kg) as 1
８０80 g / 10 min can be used.
Those having a viscosity of 〜80 g / 10 minutes are particularly preferred. Those having a melt flow rate of 1 to 80 g / 10 minutes exhibit the effect of improving the tracking resistance of the PBT resin composition.
In the case of g / 10 minutes, the effect is particularly remarkable. If the melt flow rate is less than 1 g / 10 minutes, it is difficult not only to disperse uniformly in the PBT resin, but also
The fluidity of the composition decreases, moldability deteriorates, and 80 g
If it is longer than / 10 minutes, the mechanical properties of the composition will be poor.

The compounding amount of the polyolefin of the component (D) used in the present invention is 3 to 10% by weight in the whole composition.
If the amount is less than 3% by weight, the effect of improving the tracking resistance of the PBT resin composition will not be sufficient, and if it is more than 10 parts by weight, the fluidity of the composition will decrease and the appearance of the molded article will be poor. Will come.

The metal silicate filler (E1) as the component (E) used in the present invention includes talc (magnesium silicate), kaolin (aluminum silicate), wollastonite (calcium silicate) ), Mica (aluminum silicate-potassium salt) and the like.

The glass fiber (E2) as the component (E) used in the present invention is not particularly limited as long as it is generally used for reinforcing a resin. For example, it can be selected from long fiber type (glass roving), short fiber chopped strand, milled fiber and the like.

The glass fiber (E2) is treated with a sizing agent (eg, polyvinyl acetate, polyester sizing agent, etc.), a coupling agent (eg, silane compound, boron compound, titanium compound, etc.), and other surface treatment agents. Is also good.

The fiber length of the glass fiber (E2) is preferably such that the main part in the composition has a length of 0.2 mm or more.

The total amount of the metal silicate filler (E1) and the glass fiber (E2) of the component (E) of the present invention is 30 to 40% by weight in the total composition. When the amount is less than 30% by weight, the effect of improving the tracking resistance of the PBT resin composition is not sufficient.
If it is more than 10% by weight, the fluidity of the composition becomes poor and the moldability is impaired.

The ratio of the metal silicate filler (E1) and the glass fiber (E2) in the component (E) is (E1) :( E2) = 15: 85 to 65:35 by weight.
If the proportion of the metal silicate-based filler (E1) is less than 15, the effect of improving the tracking resistance will be insufficient.
If it exceeds 5, the mechanical properties of the composition and the fluidity during molding are inferior.

In the resin composition of the present invention, if necessary, other compounding agents such as an antioxidant, a stabilizer, a coloring agent, a lubricant, a release agent, an ultraviolet absorber, an antistatic agent, and the like, exhibit their effects. It may be added in an amount.

Further, in order to further enhance the flame retardancy, a compound for suppressing dripping of molten particles during combustion may be added. Known compounds that exhibit such effects include polytetrafluoroethylene and fumed colloidal silica produced by emulsion polymerization. The use of these compounds is also useful from the viewpoint of increasing the tracking resistance of the PBT resin composition because equivalent flame retardancy can be obtained with a smaller amount of the brominated polyacrylate and sodium antimonate.

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

Furthermore, in a small proportion, other thermoplastic resins, such as other polyester resins, polyamide resins, polyphenylene sulfide resins, polyphenylene ether resins, polycarbonate resins, phenoxy resins, polystyrene and copolymers thereof, acrylic resins and acrylic resins System copolymers, polyamide elastomers, polyester elastomers, etc .; thermosetting resins such as phenolic resins, melamine resins, unsaturated polyester resins, silicone resins and the like may be blended.

In the resin composition of the present invention, it is preferable that these components are uniformly dispersed, and any method can be used for the compounding method. For example, all or part of the blended components are heated or extruded into a single-screw, twin-screw extruder or the like, and the molten resin extruded into a wire after being homogenized by melt-kneading is solidified by cooling. Next, there is a method of cutting into a desired length and granulating, but a method using another blender such as a blender, a kneader, a roll and the like 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 for molding thus produced, the resin molded product is usually supplied to a molding machine such as an injection molding machine while keeping it sufficiently dried. Furthermore, it is also possible to dry blend the constituent materials of the composition, directly charge them into a molding machine hopper, and melt-knead them in a molding machine.

Since the resin composition of the present invention has excellent flame retardancy and tracking resistance, it becomes a useful material as a material for electric / electronic parts. In particular, the terminals receiving the supply of voltage from the power supply are exposed in the space outside or inside the electrical appliance,
It can improve the safety of parts that may break the insulation of the product surface where voltage is applied due to the adhesion or adsorption of water, solution, dust, dust, and relays, connectors, transformers, bobbins, switches It can be widely applied to various parts such as breakers, power supply parts, and housings of home appliances, industrial machines and the like that use high voltage inside.

[0044]

The present invention will be described in detail with reference to the following examples. In addition,
Various properties in the examples were measured by the following methods. (1) Deflection temperature under load: Based on ASTM D648. (2) Flammability: Evaluated by a method (UL94) determined by Underwriters Laboratory, USA. (The test piece thickness is 0.
(3) Tracking resistance: IEC standard Publ. 11
2 Conforms to the second edition. (4) Mechanical properties: The tensile test conforms to ASTM D638,
Impact test conforms to ASTM D256 (Izod, notched). (5) Bromine content: A 5.0 g sample was placed in a vial (20 ml) heated to 200 ° C. with a gear aging tester, heated at 300 ° C. × 1 hr, left at room temperature for 1 hr, and then ion-exchanged water (5 ml). In addition, the mixture was stirred for 10 minutes, and the extracted water was quantified for bromine content by ion chromatography. (6) 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 8] (A) An intrinsic viscosity of 0.1 mm, which was dried with hot air at 130 ° C. for 8 hours.
72 PBT resin (manufactured by Teijin Limited), (B) brominated polyacrylate (FR-1025, Dead
Sea Bromin Co., Ltd.), Brominated polycarbonate (Fireguard FG7100, manufactured by Teijin Chemicals Ltd.), Brominated epoxy (Prasam EP100, manufactured by Dainippon Ink Industries, Ltd.), (C) Sodium antimonate (San Epoch NA1030) , Nissan Chemical Co., Ltd.), antimony trioxide (PATOX-C, manufactured by Nippon Seimitsu Co., Ltd.), (D) polypropylene (Nobrene BJ5H-MF, Mitsui Toatsu Chemicals, Inc.), (D) ethylene -Ethyl acrylate copolymer (NUC894, manufactured by Nippon Unicar Co., Ltd.),
(E) talc (PKNN, manufactured by Hayashi Kasei Co., Ltd.) and (E) glass fiber (T-124 (average fiber diameter: 13 μm, 3
mm chopped strand), manufactured by NEC Glass Co., Ltd.)
Was uniformly mixed in advance by a tumbler at the ratios shown in Table 1, and then a cylinder temperature of 260 ° C., a screw rotation speed of 150 rpm, and a discharge rate of 50 kg / hr were applied to a vacuum while using a vented twin-screw extruder having a screw diameter of 44 mm. , And the thread discharged from the die was cooled and cut to obtain molding pellets.

Next, the pellets were used in an injection molding machine having an injection capacity of 5 oz. Under the conditions of a cylinder temperature of 260 ° C., a mold temperature of 90 ° C., an injection pressure of 80 MPa, a cooling time of 12 seconds, and a total molding cycle of 40 seconds. A molded article for measurement was molded. Each characteristic was measured using these molded articles. Tables 1 and 2 show the results.

[0047]

[Table 1]

[0048]

[Table 2]

Although the PBT resin itself exhibits excellent tracking resistance, its mechanical properties such as flame retardancy, heat resistance expressed by deflection temperature under load, and tensile strength are insufficient for use in electronic parts and the like. (Comparative Example 1). However, when a PBT resin is made flame-retardant with brominated polyacrylate and sodium antimonate, and is provided with tracking resistance with polypropylene and ethylene-ethyl acrylate, and talc and glass fiber, a PBT resin composition that balances these properties. Can be obtained (Examples 1 and 2). In general, flame retardation of PBT is often carried out with brominated polycarbonate or brominated epoxy. However, these flame retardants are not preferred because the tracking resistance of the PBT resin composition is greatly reduced (Comparative Examples 2-3). Even if a brominated polyacrylate is used as a flame retardant, if antimony trioxide, which is generally used for a PBT resin, is used as a flame retardant auxiliary, heat resistance is lowered due to promotion of transesterification with a PBT polymer, and The amount of bromine generated from the product also significantly increases (Comparative Example 4). The combination of brominated polyacrylate and sodium antimonate is also an advantageous combination from the viewpoint of the amount of bromine generated (Comparative Examples 2-3 and Example 1).

As described above, the improvement of the tracking resistance is carried out with polyolefin, talc and glass fiber. When the blending amount of the polyolefin is increased, the tracking resistance is increased, but the mechanical properties are deteriorated and the molding property is reduced. This is not preferable because the surface appearance of the product becomes poor (Comparative Example 5). Also, for talc and glass fiber, a composition having a well-balanced property cannot be obtained unless the amount ratio is appropriate. That is, when the amount of talc is small and the amount of glass fiber is large, the tracking resistance is not sufficient, and when the amount of talc is large and the amount of glass fiber is small, the mechanical properties are inferior (Comparative Examples 6 and 7). Further, even when the total amount of both is increased, its fluidity and surface appearance are inferior (Comparative Example 8).

[0051]

According to the present invention, it is possible to obtain a PBT resin composition having tracking resistance to a voltage sufficiently higher than domestic and international household voltages and having good flame retardancy.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location // (C08L 67/02 23:00)

Claims (1)

[Claims] (A) Polybutylene terephthalate 29
~ 58% by weight, (B) brominated polyacrylate 6 ~ 14
% By weight, (C) 3 to 7% by weight of sodium antimonate,
(D) 3 to 10% by weight of a polyolefin, and (E) a total of 30 to 40% by weight of a metal silicate filler (E1) and glass fiber (E2), and a metal silicate filler. The weight ratio between (E1) and glass fiber (E2) is (E1).
1): A resin composition having a range of (E2) = 15: 85 to 65:35.