JPH07173375A - Flame retardant polyester resin composition for sealing molding - Google Patents

Abstract

PURPOSE:To provide a resin composition capable of metal mold forming at a low temperature without generating a non-filled portion even at a low pressure injection and any distortion and breaking of a wiring wire or a distortion of inner parts, in molding sealing molded parts including a sealed bobbin wired with a winding such as a solenoid and ones in which an inner part is protected by an outer part such as various sensors. CONSTITUTION:This flame retardant polyester resin composition for sealing molding essentially comprises (A) a polyester resin, (B) 10-60wt.% filler, (C) a sodium or potassium salt of an organic polymer having carboxylic groups or a sodium salt of a long chain fatty acid and (D) 5-25wt.% brominated flame retardant. The component (C) contains enough carboxylic groups to give a mixture of (A), (B), (C) and (D) 0.15-0.80 DELTAHH/DELTAHC ratio. The component (D) is contained to give the composition <=150 Pascal.sec melt viscosity at 280 deg.C and 1216sec<-1> shear rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, like a solenoid,
Internal parts such as sealed molded parts enclosing a bobbin that seals the wound bobbin to protect it from external factors or various sensors (intake temperature sensor, wheel speed sensor, etc.) The present invention relates to a flame-retardant polyester resin composition for encapsulation molding, which is used for molding an encapsulation molded part protected from factors.

[0002]

2. Description of the Related Art Conventionally, it has been widely known to use a brominated flame retardant such as brominated polystyrene as a flame retardant for polyester. However, a flame-retardant polyester resin composition containing a conventional brominated polystyrene (weight average molecular weight of 120,000 or more) has a high viscosity, and has low injection when used for molding a sealing molded part containing a bobbin. The pressure causes an unfilled portion, and there is a problem that deformation or cutting of the winding wire or change or destruction of the characteristics of the sensors occurs when using a normal injection pressure.

[0003]

SUMMARY OF THE INVENTION In the present invention, the external factor is a sealed molded part in which a wound bobbin is sealed without disorder of the winding like a soleinod, or internal parts of various sensors. A flame-retardant polyester resin composition for encapsulation molding, which has a low viscosity and has a crystallization rate within a certain range, which is used for molding encapsulation molded parts protected from The purpose is to provide.

[0004]

In order to solve the above-mentioned object, the present invention provides A. Polyester resin, B.I. Filling material 10
.About.60 wt% (where wt% is based on the total composition), C.I. A sodium salt or potassium salt of an organic polymer having a carboxyl group, or a sodium salt or potassium salt of a long-chain fatty acid, D.I. Brominated flame retardant 5
25% by weight, consisting essentially of component C, components A, B,
ΔH _H / ΔH _C of 0.15 to 0.80 for mixture of C and D
Having sufficient carboxyl groups to provide a ratio, Component D has a resin composition melt viscosity of 280 ° C. and a shear rate of 1216 se.
Provided is a flame-retardant polyester resin composition for encapsulation molding, which is contained so as to be 150 Pascal · sec or less in c ⁻¹ .

Examples of the polyester resin A used in the present invention are preferably polyalkylene terephthalates, such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene terephthalate-isophthalate, etc., and particularly preferred. Is polyethylene terephthalate. Polyethylene terephthalate has a volume ratio of 3: 1 methylene chloride to trifluoroacetic acid in a 3: 1 solution.
It is preferred to use those having an intrinsic viscosity at 0 ° C. of at least about 0.4, more preferably those having an intrinsic viscosity of up to about 1.2.

The filler B used in the present invention includes calcium carbonate, barium sulfate, alumina, silica, talc,
Fillers known in the art such as glass fiber, asbestos, rock wool, mica, metal or inorganic compounds, whiskers, synthetic resin fibers and the like can be used. This filler can be added in an amount of 10 to 60% by weight, preferably 15 to 55% by weight, based on the entire composition. If the compounding amount of the filler is less than 10% by weight, the mechanical properties as the encapsulating material will be insufficient, and if it is more than 60% by weight, the impact resistance will be significantly reduced.

Examples of the sodium or potassium salt of the organic polymer having a carboxyl group of the present invention include a copolymer of olefin and acrylic acid or methacrylic acid,
Examples thereof include sodium or potassium salts of a copolymer of an aromatic olefin and maleic anhydride. Preferably, sodium or potassium salts of ethylene / methacrylic acid copolymers (including both totally neutralized salts and partially neutralized salts, eg, at least about 30% neutralized salts), and styrene / Sodium salts of maleic anhydride copolymers (including both totally neutralized salts and partially neutralized salts, eg at least about 30% neutralized salts), etc., with ethylene / It is a sodium salt of a methacrylic acid copolymer. In the above copolymer, the olefin or aromatic olefin portion usually constitutes 50 to 98% by weight, preferably 80 to 98% by weight of the copolymer. Further, the copolymer can be produced by a usual high pressure polymerization technique.

Examples of acids of sodium or potassium salts of long-chain fatty acids include long-chain fatty acids having 7 to 35 carbon atoms such as pelargonic acid, capric acid, undecyl acid, lauric acid, tridecyl acid, myristic acid, Pentadecylic acid, palmitic acid, heptadecyl acid, stearic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, montanic acid; Mention may be made of fats and oils, for example fatty acids from hydrogenated products such as linseed oil, cottonseed oil, rapeseed oil, sesame oil, olive oil and the like.

Other crystal nucleating agents can be used in place of the sodium or potassium salt of the organic polymer having a carboxyl group or the sodium or potassium salt of long-chain fatty acid C contained in the present invention. Examples of other crystal nucleating agents include talc and kaolin. Further, a part or all of the polyester which is the main component of the present invention may be replaced with a polyester having a sodium or potassium terminal. This end-treated polyester is described in U.S. Pat. No. 4,425,470 and can be produced by the method described therein.

The sodium or potassium salt of an organic polymer having a carboxyl group, which is present in the composition of the present invention, is added to the mixture of components A, B and C with a Δ of 0.15 to 0.80.
Used in an amount sufficient to provide an H _H / ΔH _C ratio. Here △ _H H / H _C ratio is representative of the rate of crystallization. That is, the resin composition is molded at a mold temperature of 70 ° C.,
1/1 for 3-point support bending test used in MD790
After making a 6 ″ thick test piece, it was set at 95 ° C. and 1 ° C. on a TA Instruments 900 differential scanning calorimeter (DSC) device.
Heating between 20 ° C. (△ denoted H _H) is recorded. The test piece is then heated to 290 ° C (which is above its melting point) and the melted test piece is cooled at 10 ° C / min. About 200-2
Another exotherm at 20 ° C. (designated ΔH _C ) is the exotherm recorded for solidification of the melted specimen. In △ H _H / △ by H _C ratio too fast less than 0.15, the crystallization speed may damage the windings when used in sealing and molding part of the bobbin containing, 0.80 greater than the low temperature It has been found that the mold forming of can not be performed. The content of the sodium or potassium salt of the organic polymer having a carboxyl group or the sodium or potassium salt of the long-chain fatty acid is preferably 0.2 to 0.7 in the mixture of components A, B and C.
An amount sufficient to provide the H _H / ΔH _C ratio.

The brominated flame retardant D used in the present invention may be any known brominated flame retardant, but 280
The flame retardant must be such that the melt viscosity of the resin composition at 150 ° C. and a shear rate of 1216 sec ⁻¹ is 150 Pascal · sec or less. Specifically, brominated polystyrene or the like having a weight average molecular weight of 1,000 to 18,000 measured by gel permeation chromatography (GPC) using chloroform is mainly used, and a known weight average molecular weight of 130,000 to 180, for example. Brominated polystyrene having a weight average molecular weight of 18,000 to 80,
It is also possible to mix two or more kinds of brominated flame retardants such as 000 brominated polystyrene, brominated phthalate ester, etc., and adjust the melt viscosity of the resin composition to 150 Pascal · sec or less before use. If the melt viscosity is higher than 150 Pascal · sec, an unfilled portion will occur at a low injection pressure, and if normal injection pressure is used, the winding will be disturbed or cut, or internal parts will be deformed. It is preferably 130 Pascal · sec or less. The melt viscosity is a value measured by a capillograph manufactured by Toyo Seiki.

The blending amount of the brominated flame retardant D is 5 to 25% by weight based on the whole composition. If it is less than 5% by weight, the flame retardancy does not become VO (UL94), and if it is more than 25% by weight, the mechanical properties are deteriorated, which is not preferable.
It is preferably 10 to 20% by weight. In addition, in the encapsulation molding polyester resin composition of the present invention, in addition to the above components in an amount that does not impair the properties thereof, a plasticizer, an antioxidant, a dye, a pigment conventionally used in the art. , An additive such as a release agent can be blended.

As the plasticizer which can be used in the present invention, any plasticizer conventionally used in the art can be used, for example, modified polyethylene glycol, phthalic acid ester such as dibutyl phthalate, phthalic acid. Examples thereof include phosphoric acid esters such as dioctyl acid and butylphthalyl butyl glycolate, tricresyl phosphate, long-chain fatty acid esters such as tri-n-butyl citrate, and modified polyethylene glycol is preferable.
The amount of the plasticizer that can be used in the present invention is 0.1 to 10% by weight based on the resin composition, preferably 1
~ 8% by weight.

As the antioxidant which can be used in the present invention, any antioxidant conventionally used in the art can be used, for example, 2,6-di-t-butyl-4.
-Methylphenol (BHT), n-octadecyl-3
-(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) -propionate (Irgoanox1076), 2,
2'-methylenebis- (4-ethyl-6-t-butylphenol) (MBEPT) can be mentioned.

As the mold release agent which can be used in the present invention, any of those conventionally used in the art can be used. For example, waxes having a high melting point, higher long chain fatty acids and salts and esters thereof can be used. Examples thereof include silicone oils, silicone oil, polyvinyl alcohol, low molecular weight polyethylene, and vegetable protein derivatives, and polyethylene wax is preferable. The resin composition of the present invention may contain pigments and dyes that can be conventionally used in the art.

[0016] In [Operation] The present invention, instead of the conventional brominated flame retardants, 280 ° C., a shear rate 1216 sec ^- using brominated flame retardants such as the melt viscosity of the resin composition becomes less 150Pascal · sec at ¹ Therefore, the viscosity of the entire polyester resin can be reduced, and low-pressure injection molding required for the polyester resin for sealing can be realized. Further, by mixing a sodium or potassium salt of an organic polymer having a certain amount of a carboxyl group or a sodium or potassium salt of a long-chain fatty acid, and controlling the crystallization speed, a low temperature gold which does not disturb winding etc. Molding is possible. The method for producing the polyester resin composition of the present invention will be described. A melt kneading method is used to produce the polyester resin composition of the present invention. Each raw material component is supplied to a kneading device such as a commonly used Banbury mixer, extruder, and various kneaders at once or while supplying a filler from a side feeder, and a temperature of 280 ° C to 320 ° C, preferably 290 ° C.
The resin composition can be obtained by melt-kneading at a temperature of from ℃ to 310 ℃. The obtained resin composition was used to form a sealing-formed component including a bobbin wound like a solenoid, using an extruder or an injection molding machine. When an injection molding machine is used, the injection pressure is 400 kg / cm ² or less, preferably 300 kg / cm ² or less.

[0017]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

The following components were used in the following examples and comparative examples. PET: Polyethylene terephthalate having an intrinsic viscosity of about 0.67 to 0.58 (manufactured by DuPont) Brominated flame retardant a: Polytribromostyrene having a weight average molecular weight of 150,000 to 170,000 (Virocheck 68P manufactured by Ferro)
B) Brominated flame retardant b: weight average molecular weight 1,000 to 18,000
0 polytribromostyrene (Verocheck LM manufactured by Ferro) Brominated flame retardant c: Tetrabrom dioctyl phthalate (Vylonyl 45 manufactured by Atochem) Crystal nucleating agent: sodium salt of ethylene / methacrylic acid copolymer (Surrin manufactured by DuPont) ) Plasticizer: Modified polyethylene glycol Table 1 shows the ratio of the components used in Examples 1 and 2 and Comparative Examples 1 and 2 below.

[0019]

[Table 1]

[Example 1] PET, glass, crystal nucleating agent,
Brominated flame retardant a, brominated flame retardant b, brominated flame retardant c, and plasticizer were placed in a tumbler in the proportions shown in Table 1, and 2
After premixing for 0 minutes, twin screw extruder (Toshiba TEM35
Using B), melt kneading was carried out at a temperature of 290 ° C. to obtain a resin composition. The melt viscosity of the obtained resin composition was measured using a capillograph (manufactured by Toyo Seiki). Also, 7
Molded at a mold temperature of 0 ° C. and used as a test piece with a thickness of 1/16 ″ for a three-point support bending test used in ASTM D790. The molded plate is heated and a TA Instruments 900 differential is used. 95 ° C and 12 on a scanning calorimeter (DSC) device
The exotherm (designated ΔH _H /) between 0 ° C. was recorded. The rod is then heated to 290 ° C (which is above the melting point), the melted sample is cooled at 10 ° C / min, then about 200-220 ° C.
The heat generation (expressed as ΔH _C ) was recorded and the ΔH _H / ΔH _C ratio was determined. Furthermore, the obtained resin composition was used to seal the outside by using a wound bobbin as an insert to form a sorenode. Injection pressure 250kg / cm ² and 600kg / c
Molding was performed at m ² , and the deformation of the bobbin, the filling state, and the winding disorder were observed. The results are shown in Table 2.

Example 2 A resin composition was produced according to the method of Example 1 with the composition ratio of Example 2 in Table 1, the melt viscosity and the ΔH _H / ΔH _C ratio were measured, and the obtained resin composition was obtained. Was injection-molded and the deformation of the bobbin, the filling state, and the disorder of the winding were observed. The results are shown in Table 2.

Comparative Example 1 A resin composition was produced according to the method of Example 1 with the component ratios of Comparative Example 1 in Table 1, the melt viscosity and the ΔH _H / ΔH _C ratio were measured, and the obtained resin composition was obtained. Was injection-molded and the deformation of the bobbin, the filling state, and the disorder of the winding were observed. The results are shown in Table 2.

[Comparative Example 2] A resin composition was produced according to the method of Example 1 with the component ratios of Comparative Example 2 in Table 1, the melt viscosity and the ΔH _H / ΔH _C ratio were measured, and the obtained resin composition was obtained. Was subjected to injection molding, and the deformation of the bobbin, the filling state, and the disorder of the winding wire were observed. The results are shown in Table 2.

[0024]

[Table 2]

As shown in Table 2, when the resin compositions of Examples 1 and 2 were used, the winding was not disturbed at all, but when the resin compositions of Comparative Examples 1 and 2 were used. Indicates that the winding is disturbed, and that the resin composition of Comparative Example 2 has a short shot when molded at an injection pressure of 250 kg / cm ² . An injection pressure of 600 kg / cm ² was required to completely fill it.
When filling with an injection pressure of g / cm ^2, the bobbin was deformed and the winding was significantly disturbed.

[0026]

As described above, in the polyester resin composition of the present invention, a bobbin having a low viscosity and a constant crystallization rate, which is wound like a soreinod, is sealed. A flame-retardant polyester resin composition for encapsulation molding, which is used for molding encapsulation molding parts inside a bobbin and encapsulation molding parts in which internal parts such as various sensors are protected from external factors. Therefore, it is possible to perform low-temperature mold molding without producing an unfilled portion even at low injection pressure, and without deforming or cutting the winding wire or deforming internal parts.

Claims (1)

[Claims] 1. A. Polyester resin, B. 10 to 60% by weight of filler (where% by weight is based on the total composition), C.I. A sodium salt or potassium salt of an organic polymer having a carboxyl group or a sodium salt or potassium salt of a long-chain fatty acid, D. Consisting essentially of 5 to 25% by weight of brominated flame retardant, component C being sufficient to give the mixture of components A, B, C and D a carboxyl sufficient to give a ΔH _H / ΔH _C ratio of 0.15 to 0.80. A flame-retardant polyester resin composition for encapsulation molding, characterized in that the component D is contained so that the resin composition has a melt viscosity of 280 ° C. and a shear rate of 1216 sec ⁻¹ of 150 Pascal · sec or less. object.