JPH057421B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel thermoplastic polyester resin composition containing a thermoplastic polyester and a polyorganosiloxane graft copolymer. Thermoplastic polyesters, such as polyalkylene terephthalate, have excellent mechanical properties, heat resistance stability, weather resistance, electrical insulation properties, etc., and are therefore used in a wide range of fields such as electrical and electronic parts and automobile parts. However, its use is severely limited due to its low impact resistance, especially notched impact strength. Various methods have been proposed to improve the impact resistance of thermoplastic polyester, and although these methods have had some success in improving impact resistance, they have not been fully used because they sacrifice other properties. The current situation is that there is no such thing. For example, impact resistance can be improved by blending diene rubber reinforced resin with thermoplastic polyester, but
On the contrary, heat stability and weather resistance are significantly reduced. On the other hand, when acrylic rubber reinforced resin is blended,
Although there is little decrease in weather resistance, there is almost no impact resistance improvement effect at low temperatures. Olefin copolymers are also effective in improving impact resistance, but they have problems such as deterioration of other mechanical properties, poor dispersibility, and delamination, making them unusable. The inventors of the present invention have conducted intensive studies on methods for improving impact resistance while maintaining the excellent heat stability, weather resistance, etc. originally inherent in thermoplastic polyester. It becomes possible to graft polymerize with
It has been discovered that by blending this graft copolymer with a thermoplastic polyester, it is possible to significantly improve impact resistance, and to obtain a product with excellent heat stability and weather resistance, and has thus arrived at the present invention. The present invention consists of a thermoplastic polyester (A) of 80 to 10% by weight and a swelling degree of 3.0 to 3.0 when measured in a toluene solvent.
15.0 and is obtained by graft polymerizing 95 to 10% by weight of one or more vinyl monomers to 5 to 90% by weight of polyorganosiloxane rubber containing a graft cross-agent. Copolymer (B) 20-90% by weight and filler (C) 0
It is a thermoplastic polyester resin composition characterized by containing ~60% by weight. The composition of the present invention has excellent heat stability, impact resistance, and weather resistance, and can be obtained from hard to soft by changing the blending ratio of component (A) and component (B). Impact resistance can also be freely designed. The thermoplastic polyester (A) used in the present invention is mainly composed of an aromatic dicarboxylic acid having 8 to 22 carbon atoms and an alkylene glycol, cycloalkylene glycol, or aralkylene glycol having 2 to 22 carbon atoms. It may contain a lesser amount of aliphatic carboxylic acids such as adipic acid and sebacic acid, and may also contain polyalkylene glycols such as polyethylene glycol and polytetramethylene glycol. Particularly preferred polyesters include polyethylene terephthalate and polytetramethylene terephthalate. Mixtures of two or more of these thermoplastic polyesters may also be used. The polyorganosiloxane graft copolymer (B) used in the present invention is a graft copolymer consisting of 5 to 90% by weight of polyorganosiloxane rubber and 95 to 10% by weight of one or more vinyl monomers. It is a combination. The polyorganosiloxane component contains at least 50% by weight, especially 70% by weight or more of siloxane units represented by the following formula R ³ SiO () (wherein R ³ represents a methyl group, an ethyl group, a propyl group or a phenyl group). It is preferable that there be. As a graft cross-agent, the general formula (CH ₂ = CH) SiR ¹ _o O _(3-o)/2 () or HS(-CH ₂ )- _p SiR ¹ _o O _(3-o)/2 () (In the formula, R ¹ is a methyl group, Ethyl group, propyl group or phenyl group, R ² is a hydrogen atom or methyl group,
Compounds having a unit represented by n is 0, 1 or 2, and p is a number from 1 to 6 are used. (Meth)acryloxysiloxanes and mercaptosiloxanes of formulas () and () are preferred from the viewpoint of grafting efficiency. The amount of the grafting agent added is 0.01 to 50% by weight in the polyorganosiloxane rubber, preferably 0.1 to 20% by weight.
Weight%. The polymerization of this polyorganosiloxane is carried out by the method described in U.S. Pat. Preferably, it is produced by a method of shear mixing with water. Alkylbenzenesulfonic acid is suitable because it acts as an emulsifier for polyorganosiloxane and also serves as a polymerization initiator. At this time, it is preferable to use an alkylbenzenesulfonic acid metal salt in combination, since this is effective in maintaining the stability of the polymer during graft polymerization. Examples of organosiloxane include hexamethyltricyclosiloxane, octamethyltetracyclosiloxane, decamethylpentacyclosiloxane, dodecamethylhexacyclosiloxane,
trimethyltriphenyltricyclosiloxane,
Tetramethyltetraphenyltetracyclosiloxane, octaphenyltetracyclosiloxane, etc. are used. As the crosslinking agent, trifunctional or tetrafunctional siloxane crosslinking agents such as trimethoxymethylsilane, triethoxyphenylsilane, methyl orthosilicate, ethyl orthosilicate, butyl orthosilicate, etc. are used. The amount of the crosslinking agent used is 0.1 to 40% by weight in the polyorganosiloxane rubber, and the amount used is determined by the degree of swelling of the polyorganosiloxane (when the polyorganosiloxane is saturated in a toluene solvent at 25°C, the amount absorbed by the polyorganosiloxane (weight ratio of toluene) is 3.0
It is necessary to adjust it so that it is in the range of ~15.0. If the swelling degree is less than 3.0, the amount of crosslinking agent becomes too large and rubber elasticity cannot be obtained. Also, the degree of swelling
If it exceeds 15.0, it will not be possible to maintain the rubber form. The degree of swelling is measured as follows. The prepared polyorganosiloxane latex was
A siloxane polymer is obtained by adding the emulsion into ~5 times the amount of isopropyl alcohol with stirring, breaking the emulsion, and coagulating it. The polymer thus obtained was washed with water and then dried under reduced pressure at 80°C for 10 hours. After drying, approximately 1 g of the polymer is accurately weighed, immersed in approximately 30 g of toluene, and left at 25° C. for 10 hours. Toluene is added to the polymer to swell it. Next, the remaining toluene is separated and removed by decantation, weighed accurately, and then dried under reduced pressure at 80° C. for 16 hours, the absorbed toluene is removed by evaporation, and weighed accurately again. The swelling degree is calculated by the following formula. Swelling degree = (swollen polymer weight) - (dry polymer weight) / (dry polymer weight) As the vinyl monomer to be graft-polymerized to this polyorganosiloxane rubber, styrene, α
-Methylstyrene, methylmethacrylate, 2-
Ethylhexyl methacrylate, ethyl acrylate, butyl acrylate, acrylonitrile,
Methacrylonitrile, ethylene, propylene, butadiene, isoprene, chloroprene, vinyl acetate, vinyl chloride, vinylidene chloride, allyl methacrylate, triallylisocyanurate, ethylene dimethacrylate, methacrylic acid ester, acrylic acid ester, conjugated diolefin, etc., and two of these. Mixtures of more than one species are used. The ratio of vinyl monomer to polyorganosiloxane rubber is 5 to 90%.
The vinyl monomer content is 95 to 10% by weight. If the polyorganosiloxane component is less than 5% by weight, the effect of improving the impact resistance of the composition will not be sufficient, and if it is more than 90% by weight, the grafting effect will not be exhibited. A polyorganosiloxane-based graft copolymer is obtained by polymerizing a vinyl monomer in a polyorganosiloxane rubber latex obtained by a conventional emulsion polymerization method in one or multiple steps using radical polymerization technology. . The composition of the present invention includes, for example, 80 to 10 parts by weight of the thermoplastic polyester (A), 20 to 90 parts by weight of the polyorganosiloxane graft copolymer (B), and a filler.
(C) It is obtained by blending each component in a proportion of 0 to 60 parts by weight so that the total amount of each component is 100 parts by weight.
It is preferable to melt and mix this mixture and then shape it into pellets. Fillers (C) can be in various shapes, such as glass fibers, carbon fibers, aramid fibers, metal fibers, asbestos, fibrous fillers such as whiskers, glass beads, glass flakes, calcium carbonate, and talc. , mica, aluminum oxide, magnesium hydroxide, boron nitride, beryllium oxide, calcium silicate, clay, metal powder, and other natural or synthetic fillers in the form of spherical, plate-like, or amorphous powder particles. These fillers (C) have the effect of reinforcing mechanical properties, particularly rigidity and heat resistance, and are used alone or in combination. Polyester resins containing reinforcing fillers are well known, but the addition of fillers often results in a reduction in impact resistance. Since the reinforced resin composition of the present invention exhibits good impact resistance and thermal stability,
Improved heat resistance due to reinforcing agents can be effectively utilized. The composition of the present invention may optionally contain dyes and pigments, light or heat stabilizers, brominated epoxy, brominated polycarbonate, decabromodiphenyl ether,
It may contain known flame retardants such as antimony oxide, crystal nucleating agents, various modifiers, mold release agents such as wax, and the like. Reference Example 1 Production of polyorganosiloxane latex: 3.0 parts by weight of ethyloxosilicate, 1.0 parts by weight of γ-methacryloxypropyldimethoxymethylsilane
Parts by weight and octamethyltetracyclosiloxane
96.0 parts by weight were mixed to obtain 100 parts by weight of mixed siloxane. 100 parts of siloxane mixed with 300 parts by weight of distilled water in which 1.0 parts by weight of dodecylbenzenesulfonic acid was dissolved.
After adding parts by weight and pre-stirring at 10,000 rpm with a homogenizer, 300Kg/
Emulsification and even dispersion can be achieved by passing it twice at a pressure of cm ² .
A polyorganosiloxane latex was obtained. This liquid mixture was transferred to a separable flask equipped with a condenser and a stirring blade, heated at 85°C for 4 hours while stirring and mixing, and then cooled at 5°C for 24 hours. The pH of this latex is then adjusted with an aqueous sodium hydroxide solution.
was neutralized to 7.2 to complete the polymerization. The polymerization rate of the obtained polyorganosiloxane was 91.2%, the solid content concentration was 22.74% by weight, the degree of swelling was 7.4, and the particle size of the polyorganosiloxane was 0.150μ. Reference Example 2 Production of polyorganosiloxane latex: 3.0 parts by weight of ethyl orthosilicate, 2.0 parts by weight of γ-mercaptopropyldimethoxymethylsilane and 95 parts by weight of octamethyltetracyclosiloxane were mixed to obtain 100 parts by weight of mixed cyclohexane. The following emulsification, dispersion, and polymerization were carried out in the same manner as in Reference Example 1, and the mixture was neutralized to pH 6.8 with an aqueous sodium hydroxide solution. The polymerization rate of the obtained polyorganosiloxane was 90.8%, the solid content concentration was 22.64% by weight, the degree of swelling was 6.9, and the particle size of the polyorganosiloxane was 0.156μ. Reference Example 3 Production of polyorganosiloxane latex: 3.0 parts by weight of ethyl orthosilicate, 2.0 parts by weight of tetravinyltetramethyltetracyclosiloxane, and 95 parts by weight of octamethyltetracyclosiloxane.
Parts by weight were mixed to obtain 100 parts by weight of mixed siloxane. The following emulsification, dispersion and polymerization were carried out in the same manner as in Reference Example 1 and neutralized to pH 7.0 with an aqueous sodium hydroxide solution. The polymerization rate of the obtained polyorganosiloxane was 91.6%, the solid content concentration was 22.8% by weight, and the degree of swelling was 7.3.
and the particle size of polyorganosiloxane is
It was 0.152μ. Reference example 4 Polyorganosiloxane-based graft copolymer S
-1 Production: 263.9 parts by weight of the latex obtained in Reference Example 1 (solid content concentration 22.74% by weight) was placed in a separable flask, the atmosphere was replaced with nitrogen, the temperature was raised to 70°C, and 10 parts by weight of acrylonitrile and styrene were added. 30 parts by weight and t
- A monomer mixture consisting of 0.08 parts by weight of butyl hydroperoxide was charged and stirred for 30 minutes. In addition, 0.12 parts by weight of Rongarit, 0.0002 parts of ferrous sulfate
Parts by weight, ethylenediaminetetraacetic acid disodium salt
Radical polymerization was started by adding an aqueous solution of 0.0006 parts by weight and 10 parts by weight of water, and after the exotherm of polymerization disappeared, the reaction temperature was maintained for 2 hours to complete the polymerization. The resulting graft copolymer had a polymerization rate of 97%, a grafting rate of 48%, and a grafting efficiency of 72%. The obtained latex was mixed with 5 ml of calcium chloride dihydrate.
The polymer was coagulated and separated by dropping it into hot water in which parts by weight were dissolved, and dried to remove moisture to obtain dry powder S-1. Reference example 5 Polyorganosiloxane-based graft copolymer S
-2, Production of S-3 and S-4: 263.9 parts by weight of the latexes obtained in Reference Examples 1, 2 and 3 (solid content concentration 22.74% by weight),
265.0 parts by weight (solid content concentration 22.64% by weight) and 262.7 parts by weight (solid content concentration 22.84% by weight) were placed in a separable flask, and after purging with nitrogen, the temperature was raised to 70°C. Additionally, 0.12 parts by weight of Longatto, ferrous sulfate
An aqueous solution containing 0.0002 parts by weight, 0.0006 parts by weight of ethylenediaminetetraacetic acid disodium salt, and 10 parts by weight of water was added. Furthermore, a monomer mixture consisting of 10 parts by weight of acrylonitrile, 30 parts by weight of styrene, and 0.08 parts by weight of t-butyl hydroperoxide was added dropwise over 60 minutes, and polymerization was allowed to proceed while being charged. After the dropwise addition was completed, the reaction temperature was maintained for 2 hours to complete the polymerization. The polymerization rates of the obtained graft copolymers were 96.8%, 98.2%, and 96.3%, respectively, the grafting rates were 36%, 21%, and 11%, and the grafting efficiency was 54%.
They were 31.5% and 16.5%. The obtained latex was coagulated and dried in the same manner as in Reference Example 4, and dried powder S-
2, S-3 and S-4 were obtained. Examples 1 to 4 Polytetramethylene terephthalate and polyorganosiloxane graft copolymer S-1 having an intrinsic viscosity [η] of 1.05 were mixed in the proportions shown in Table 1, and the cylinder temperature was adjusted using a 40φ single vent extruder.
The resin compositions were melt-mixed at 220 to 250°C and shaped into pellets to obtain a resin composition. After drying these pellets, injection molding was performed at a cylinder temperature of 245°C and a mold temperature of 60°C to obtain various test pieces for evaluation. The evaluation results are shown in Table 1. Moreover, the composition of the comparative example was also molded and evaluated under the same conditions as the example. In the composition of Comparative Example 2, the weight ratio of acrylonitrile/polybutadiene/styrene was 10/instead of copolymer S-1.
This was obtained in the same manner as in the example except that a 60/30 ABS graft copolymer was used. As is clear from Table 1, the molded articles obtained from the compositions of the present invention have excellent impact resistance and thermal stability.

[Table] Examples 5 to 11 Polytetramethylene terephthalate (PTMT) with intrinsic viscosity [η] of 0.92, intrinsic viscosity [η] of 0.85
Polyethylene terephthalate (PET) and polyorganosiloxane graft copolymer S-
2, S-3, and S-4 are blended in the proportions shown in Table 2, melt-mixed through an extruder in the same manner as in Example 1 at a cylinder temperature of 250°C or 275°C, and shaped into pellets to obtain a composition. I got it. These are 240 for PTMT series.
℃, and the PET type was injection molded at 275℃ to obtain molded pieces for evaluation. These evaluation results are shown in Table 2.

【table】

[Table] Example 12 Polytetramethylene terephthalate with an intrinsic viscosity [η] of 0.85, polyorganosiloxane graft copolymer S-2, commercially available chopped strand glass fiber with a fiber length of 3 mm, and 325 mesh pass wolast Night powder was blended in the proportions shown in Table 3, extruded at 250°C in the same manner as in Example 1, and shaped into pellets to obtain a reinforced composition. Using this, a flat plate of 100 x 100 x 3 (mm) was injection molded at a cylinder temperature of 250°C and a mold temperature of 80°C.
A falling weight impact test was conducted. The results are shown in Table 3. The composition of the present invention provides good impact resistance. Also, in terms of weather resistance, the inherent properties of polyester are not degraded.

【table】

Claims (1)

[Claims] 1. Thermoplastic polyester (A) 80 to 10% by weight, with a degree of swelling measured in a toluene solvent of 3.0 to 15.0,
A polyorganosiloxane-based graft copolymer obtained by graft polymerizing 95-10% by weight of one or more vinyl monomers to 5-90% by weight of a polyorganosiloxane rubber containing a graft cross-agent ( A thermoplastic polyester resin composition containing 20 to 90% by weight of B) and 0 to 60% by weight of a filler (C). 2 Graft crossover agent has general formula or HS( _-CH2 ) _{-pSiR1oO ( 3-o)/2} (in the formula, ^R1 is a methyl group, ethyl group, propyl ^group , or phenyl group, ^R2 is a hydrogen atom or a methyl group,
The composition according to claim 1, which is an organosiloxane graft cross-agent having a unit represented by the following formula: n is 0, 1 or 2, p is a number from 1 to 6.