JPH0420023B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant polyester resin composition reinforced with glass fibers having excellent mechanical properties, thermal properties, moldability, etc. Glass fiber reinforced polyethylene terephthalate resins are widely used as engineering plastics because they have excellent resin properties such as mechanical properties, thermal properties, chemical resistance, and moldability. However, like other synthetic resins, this glass fiber reinforced polyester resin also has the problem of flammability.
The significance of making it flame retardant is great. Glass fiber reinforced products of polyethylene terephthalate usually have a relatively high molding temperature of 250 to 300°C, so the heat resistance of the flame retardant is important. For this reason, there is a need for a flame retardant that hardly decomposes even at high temperatures and that does not color the final molded product or deteriorate the resin properties. Furthermore, glass fiber reinforced polyethylene terephthalate has a high heat distortion temperature and is widely used as a material for products such as electrical parts that are used in high-temperature environments. Therefore, when making such polyester resin glass fiber reinforced materials flame retardant, in addition to initial physical properties such as flame retardance, mechanical strength, and heat resistance, it is necessary to It is important that the flame retardance does not deteriorate due to heat loss of the flame agent, and so-called heat-resistant stability of the molded product is required. Since the flame retardant of the general formula I described later has excellent heat resistance and flame retardancy, the present inventors combined it with antimony trioxide and blended it into a glass fiber reinforced material of polyethylene terephthalate to create a flame retardant material. I tried to improve. However, compositions containing a small amount of the flame retardant of Formula I have improved mechanical properties in addition to improved flame retardancy, resulting in compositions with excellent performance. However, depending on the conditions during the molding process, for example, if the temperature during injection molding is increased or the residence time is lengthened, fluidity may decrease, resulting in poor moldability. There is. As a result of repeated studies in order to improve these drawbacks, the present inventors have found that at least two kinds of flame retardants having a specific structure are blended together with antimony trioxide in a specific amount in a specific range into a polyethylene terephthalate resin containing glass fiber. As a result, it is possible to obtain a flame-retardant polyethylene terephthalate resin composition with excellent mechanical properties and extrusion workability without deteriorating thermal properties and flame retardancy. The present invention was achieved by discovering that the flame retardancy of the resin composition can be further improved by blending the resin composition. The present invention provides polyethylene terephthalate resin,
Glass fiber, general formula (In the formula, X is a hydrogen atom, a chlorine atom, or a bromine atom, m
is a number with an average value of 0 to 11, R ₁ is a glycidyl group, a group

[Formula] represents a hydrocarbon group, a halogenated hydrocarbon group or a group _-COR4 , where _R2
and one of R ₃ is a hydroxyl group, the other is an alkoxy group that may have a halogen atom, a phenoxy group,
Flame retardants with a halogen content of 10% by weight or more represented by an amino group or a carboxy group, R ₄ means a hydrocarbon group or a halogenated hydrocarbon group, hexabrombiphenyl ether (hereinafter abbreviated as HBBE) and It is composed of antimony oxide, and the flame retardant [I] is 1 to 20 parts by weight and HBBE is 2 to 30 parts by weight per 100 parts by weight of polyethylene terephthalate resin, and the weight ratio of the flame retardant [I] and HBBE is [I]/ HBBE is in the range of 0.2<[I]/HBBE≦4, and the total amount of flame retardant [I] and HBBE is 3
This is a flame-retardant polyester resin composition in which 40 parts by weight of antimony trioxide, 2 to 30 parts by weight of antimony trioxide, and 5 to 60 parts by weight of glass fiber based on the total resin composition. In addition to the above-mentioned composition, the present invention further provides a flame retardant composition containing 1 to 40% by weight of an inorganic compound and a total amount of glass fiber and inorganic compound of 60% by weight or less based on the total resin composition. It is a polyester resin composition. The resin composition of the present invention comprises a flame retardant of general formula I and
By using HBBE in combination in the above range, it is possible to obtain a resin composition that exhibits heat resistance and flame retardancy equivalent to that of a resin composition using the flame retardant of formula I, and has an excellent balance of mechanical properties and moldability. This is the resin composition obtained. Furthermore, by incorporating a specific amount of an inorganic compound, the flame retardance of the composition can be further improved, and in particular, the drip prevention effect during combustion can be improved. The polyethylene terephthalate resin used in the present invention is a linear polyester whose main constituent unit is ethylene terephthalate units, or a linear resin obtained by cocondensation polymerization of a small amount of other polyhydric alcohols, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, etc. Polyesters, as well as mixtures of these polyesters or copolyesters with other thermoplastic materials, are used. The intrinsic viscosity [η] of the linear polyester or linear copolyester is preferably in the range of 0.4 to 1.5 at 5° C. in a mixed solvent of equal weights of tetrachloroethane/phenol. The type of glass fiber used in the present invention is not particularly limited, and both roving type and chopped strand type can be used, but chopped strand type is preferred from the viewpoint of productivity. In this case, workability during mixing, wear of the molding machine,
Considering cutting during the molding process, the length is 0.4 to 6.
A glass fiber length of about 0.2 to 3 mm is particularly preferable, and it is sufficient if the length of the glass fiber in the final molded product is about 0.2 to 3 mm. Commercially available glass fibers that have undergone various treatments can be used as they are. The blended amount of glass fiber is polyethylene terephthalate resin, glass fiber,
It accounts for 5 to 60% by weight of the total resin composition consisting of the flame retardant and antimony trioxide. If the amount is less than 5% by weight, the effect of reinforcing the glass fibers will be small, and if the amount is more than 60% by weight, the molding processability from the viewpoint of flowability will deteriorate, which is not preferable. Furthermore, the flame retardant used in the present invention is represented by general formula I, and one important factor is that m in formula I, which represents the average degree of polymerization of the flame retardant, is 11 or less; When a flame retardant with a large molecular weight is blended, it is difficult to uniformly disperse the flame retardant in the resin composition, which is undesirable because it causes deterioration of the resin properties. In addition, if the halogen content of the flame retardant is less than 10% by weight, the amount is too small and it is difficult to obtain sufficient flame retardancy; This is not preferable since it tends to decrease. Flame retardants of formula I include, for example, the following compounds. In addition, the group -Z in the formula is a group means. Further, the other flame retardant must be hexabrom biphenyl ether, and decabrom biphenyl ether of the same type with a different amount of bromine is not preferred. In other words, when a molded article of decabrom biphenyl ether is exposed to high temperatures, decabrom biphenyl ether precipitates on the surface of the molded article, giving the appearance of white powder. In contrast, with hexabrom biphenyl ether, the flame retardant escapes little at high temperatures, and the surface of the molded product does not change. The blending amount of the flame retardant is 1 to 20 parts by weight of the flame retardant of formula I per 100 parts by weight of the polyethylene terephthalate resin.
parts by weight, HBBE is 2 to 30 parts by weight, and the weight ratio of flame retardant [I] to HBBE [I]/HBBE is <0.2
[I]/HBBE≦4, and flame retardant [I]
and HBBE in a total amount of 3 to 40 parts by weight. In addition, when the total amount of flame retardant [I] and HBBE is relatively large within the above range, the above [I]/HBBE
It is preferable to set the ratio to about 0.5 to 3. The amount of antimony trioxide blended is in the range of 2 to 30 parts by weight, preferably 2 to 20 parts by weight, based on 100 parts by weight of the polyethylene terephthalate resin. If the amount of antimony trioxide exceeds 30 parts by weight, the mechanical strength will decrease, which is not preferable. Note that when the amount of flame retardant is relatively small, it is preferable to increase the amount of antimony trioxide blended within the scope of the present invention. Furthermore, when the amount of flame retardant is relatively large, it is preferable to reduce the amount of antimony trioxide blended within the scope of the present invention. Furthermore, in the present invention, the flame retardancy and drip resistance of the composition can be improved by blending an inorganic compound. The inorganic compound is not particularly limited, but silicic acid or silicates are preferred. Specifically, talc, kaolin, walrus night, silica, mica, diatomaceous earth, quartz powder, clay,
Examples include white carbon. Among these, talc has the effect of improving molding processability, and white carbon is particularly preferable since it has a remarkable effect of improving drip resistance. These inorganic compounds can be used alone or in a mixture of two or more. The blending amount thereof is 1 to 40% by weight in the total resin composition. If the amount of the inorganic compound added is less than 1% by weight, the effect of improving drip resistance will be small. Note that the glass fiber and the inorganic compound must be blended in such a way that the total amount is 60% by weight or less in the total resin composition. In preparing the composition of the invention, for example, sufficiently dried polyethylene terephthalate resin chips, glass fibers, a flame retardant of formula I and
HBBE, antimony trioxide, and if desired, an inorganic compound are uniformly mixed in a V-type blender, etc., and then melt-mixed, or the polymer, flame retardant, antimony trioxide, and further inorganic compound are first melt-mixed, and then glass fibers are mixed. may be added. Additives such as stabilizers against light or heat, dyes and pigments, and crystal nucleating agents can be added to the resin composition of the present invention, if necessary. Examples 1 to 6 and Comparative Examples 1 to 4 Thoroughly dried polyethylene terephthalate (abbreviated as PET) with an intrinsic viscosity of 0.72 measured at 25°C in a mixed solvent of equal weights of tetrachloroethane and phenol, sodium benzoate, and the length A chopped strand of 3 mm glass fiber, a flame retardant, antimony trioxide and an inorganic compound were uniformly mixed for 5 minutes in a V-type blender in the proportions shown in the table below. Next, these mixtures were extruded using a 40 mmφ vented extruder at a cylinder temperature of 260 to 280°C to form pellets. These pellets are 5 ounces of 36mmφ
Using a screw-type injection molding machine, cylinder temperature
Injection molded at 280℃, mold temperature 80℃, thickness 3.2mm
A test piece for measuring bending strength and a test piece for measuring flammability with a thickness of 1.5 mm were obtained. The molding cycle is Comparative Example 3.
All times were set to 60 seconds except for 120 seconds. Mechanical properties and flame retardancy were evaluated using these test pieces. Processability was evaluated using the shot shot condition when the molding cycle during injection molding was 120 seconds, which was longer than a typical molding cycle. That is, the initial injection pressure was set to shot shot + 105 Kg/cm ² , and the melt viscosity increased during molding, and the evaluation was made based on the number of shots until it became a shot shot at this pressure. These evaluation results are shown in the table below. Moreover, the bending strength in the table shows the value determined according to ASTM D-638. In addition, flame retardancy was measured according to the Underwriters Laboratories Bulletin 94 (UL-94) flame test, 127 mm x 12.7 mm x 1.5 mm.
The flame test was conducted 10 times on five test pieces. The flame retardant (A) in the table is a compound of the following formula, and (B) is HBBE.
means. Flame retardant (A): As is clear from this result, it is known that it is important to mix the flame retardant (A) and HBBE in a specific ratio from the viewpoint of processability. It is also known that flame retardancy and drip resistance can be improved by further blending an inorganic compound.

【table】

Claims (1)

[Claims] 1. Polyethylene terephthalate resin, glass fiber, general formula (In the formula, X is a hydrogen atom, a chlorine atom, or a bromine atom, m
is a number with an average value of 0 to 11, R ₁ is a glycidyl group, a group [formula], a hydrocarbon group, a halogenated hydrocarbon group, or a group -COR ₄ , where R ₂
and one of R ₃ is a hydroxyl group, the other is an alkoxy group that may have a halogen atom, a phenoxy group,
Flame retardants with a halogen content of 10% by weight or more represented by an amino group or a carboxy group, R ₄ means a hydrocarbon group or a halogenated hydrocarbon group, hexabrombiphenyl ether (hereinafter abbreviated as HBBE) and It is composed of antimony oxide, and the flame retardant [I] is 1 to 20 parts by weight and HBBE is 2 to 30 parts by weight per 100 parts by weight of polyethylene terephthalate resin, and the weight ratio of the flame retardant [I] and HBBE is [I]/ HBBE is in the range of 0.2<[I]/HBBE≦4, and the total amount of flame retardant [I] and HBBE is 3
40 parts by weight, antimony trioxide in an amount of 2 to 30 parts by weight, and glass fiber in an amount of 5 to 60 parts by weight based on the total resin composition. 2 Polyethylene terephthalate resin, glass fiber, inorganic compound, general formula (In the formula, X is a hydrogen atom, a chlorine atom, or a bromine atom, m
is a number with an average value of 0 to 11, R ₁ is a glycidyl group, a group [formula], a hydrocarbon group, a halogenated hydrocarbon group, or a group -COR ₄ , where R ₂
and one of R ₃ is a hydroxyl group, the other is an alkoxy group that may have a halogen atom, a phenoxy group,
Flame retardants with a halogen content of 10% by weight or more represented by an amino group or a carboxy group, R ₄ means a hydrocarbon group or a halogenated hydrocarbon group, hexabrombiphenyl ether (hereinafter abbreviated as HBBE) and It is composed of antimony oxide, and the flame retardant [I] is 1 to 20 parts by weight and HBBE is 2 to 30 parts by weight per 100 parts by weight of polyethylene terephthalate resin, and the weight ratio of the flame retardant [I] and HBBE is [I]/ HBBE is in the range of 0.2<[I]/HBBE≦4, and the total amount of flame retardant [I] and HBBE is 3
~40 parts by weight and antimony trioxide in an amount of 2 to 30 parts by weight, and based on the total resin composition, 5 to 60% by weight of glass fibers and 1 to 40% by weight of inorganic compounds, glass fibers and inorganic compounds. A flame-retardant polyester resin composition containing a total amount of 60% by weight or less.