JP2988684B2 - Thermoplastic polyester resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermoplastic polyester resin having improved impact resistance. More specifically, the present invention relates to a thermoplastic polyester resin composition having excellent impact resistance, comprising a thermoplastic polyester resin and a polyorganosiloxane-based rubber and a specific organic silane compound, and, if necessary, a reinforcing filler.

(Prior art)

Thermoplastic polyesters, for example, polyalkylene terephthalate, have excellent mechanical properties, heat resistance, weather resistance, electrical insulation, etc.
It is used in a wide range of fields such as automobile parts. However, their low impact resistance, especially the notched impact strength, has severely limited their applications. Various methods for improving the impact resistance of this thermoplastic polyester have been proposed, and they have been somewhat successful in improving the impact resistance, but at the same time sacrificing other properties, which are practically sufficient. Not satisfactory. For example, by adding a diene rubber reinforced resin to a thermoplastic polyester, impact resistance is improved, but heat resistance and weather resistance are significantly reduced. On the other hand, when an acrylic rubber reinforced resin is blended, the effect of improving the impact resistance at low temperatures is almost negligible, though the decrease in weather resistance is small. Although the addition of an olefin copolymer is effective in improving impact resistance, it has other problems such as lowering of other mechanical properties, poor dispersibility, and delamination, making it unusable.

[Problems to be solved by the invention]

The present inventors have studied the method of improving the impact resistance while maintaining the original excellent heat resistance stability, weather resistance, etc. of the thermoplastic polyester, and as a result, it has a polyorganosiloxane rubber and a specific functional group. The inventor has found that by blending an organic silane compound with a thermoplastic polyester resin, the impact resistance is remarkably improved, and a resin composition having excellent heat resistance and mechanical strength is obtained.

[Means for solving the problem]

The present invention relates to a polyorganosiloxane rubber having (A) a thermoplastic polyester resin of 99 to 60 parts by weight, (B) an average particle diameter of 0.05 to 0.5 μm, and a swelling degree of 3 to 50 measured in a toluene solvent. 1 to 40 parts by weight, (C) 0.01 to 10 parts by weight of an organic silane compound having at least one functional group selected from an epoxy group, an isocyanate group and an amino group (the sum of (A) and (B) A thermoplastic polyester resin composition comprising: (D) 0 to 300 parts by weight of a reinforcing filler (based on a total of 100 parts by weight of the above (A) and (B)). Things.

The thermoplastic polyester (A) used in the present invention mainly comprises 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. May contain an inferior amount of an aliphatic dicarboxylic acid, for example, adipic acid or sebacic acid, or may contain an inferior amount of a polyalkylene glycol such as polyethylene glycol or polytetramethylene glycol. Particularly preferred polyesters include polyethylene terephthalate, polybutylene terephthalate (polytetramethylene terephthalate), polycyclohexylene dimethylene terephthalate, and cyclohexylene dimethylene terephthalate as main constituent units, and a copolymer component comprising ethylene glycol or isophthalic acid. Polymers.

The polyorganosiloxane rubber used in the present invention has an average particle diameter of 0.05 to 0.5 μm, a swelling degree measured in a toluene solvent of 3 to 50, and is a rubber obtained by copolymerizing an organosiloxane and a crosslinking agent. .

Examples of the organosiloxane constituting the polyorganosiloxane rubber include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, and tetramethyltetraphenyl. Cyclotetrasiloxane, octaphenylcyclotetrasiloxane and the like can be mentioned, and these can be used alone or in combination of two or more. Among the polyorganosiloxane rubbers obtained using these organosiloxanes, those containing polydimethylsiloxane as a main component are preferable. The amount of organosiloxane used is 50% by weight in the polyorganosiloxane rubber.
Or more, preferably 70% by weight or more.

As a crosslinking agent used for preparing the polyorganosiloxane rubber, a trifunctional or tetrafunctional siloxane crosslinking agent such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane Are used. The amount of the cross-linking agent used is 0.2 to 30% by weight based on the weight of the obtained polyorganosiloxane-based rubber, and the amount used is the degree of swelling of the polyorganosiloxane-based rubber (when the polyorganosiloxane-based rubber is dissolved in a toluene solvent). When saturated at 25 ° C., the weight is preferably adjusted so that the weight ratio of toluene absorbed by the polyorganosiloxane rubber is in the range of 3 to 50. If the degree of swelling is less than 3, the amount of the cross-linking agent becomes too large and rubber elasticity tends to be hardly obtained. If the degree of swelling exceeds 50, the rubber form tends to be difficult to maintain, and thus sufficient impact resistance is obtained. It is difficult to impart properties.

The measurement of the degree of swelling is performed as follows. That is,
The polyorganosiloxane rubber latex obtained by polymerization is added to about 3 to 5 times the amount of isopropyl alcohol with stirring, and the emulsion is broken and solidified to obtain a siloxane polymer. After the obtained polymer is washed with water, it is dried under reduced pressure at 80 ° C. for 10 hours. After drying, about 1 g of the polymer is precisely weighed, immersed in about 60 g of toluene, and left at 25 ° C. for 100 hours to swell. Next, the remaining toluene is separated and removed by decantation, precisely weighed, and then dried under reduced pressure at 80 ° C. for 16 hours to remove the absorbed toluene by evaporation and weigh again. The degree of swelling is calculated by the following equation.

For the polymerization of the polyorganosiloxane rubber, the methods described in U.S. Pat. Nos. 2,891,920 and 3,247,725 can be used. A preferred example of a method for preparing a polyorganosiloxane rubber is a method in which a mixed solution of an organosiloxane and a crosslinking agent is shear-mixed with water in the presence of an emulsifier such as alkylbenzenesulfonic acid or alkylsulfonic acid. Alkylbenzene sulfonic acid is suitable because it acts as an emulsifier for the organosiloxane and also serves as a polymerization initiator. At this time, the combined use of a metal salt of an alkyl benzene sulfonic acid, a metal salt of an alkyl sulfonic acid, or the like is effective in stably maintaining the latex.

The average particle size of the polyorganosiloxane rubber is 0.1μ
If it is smaller than m or larger than 0.5 μm, sufficient impact resistance may not be exhibited. The average particle size of the polyorganosiloxane-based rubber was measured by a quasi-elastic light scattering method (MALVERN / SYSTEM4600, measuring temperature 25 ° C,
Using a scattering angle of 90 °), a sample solution is prepared by diluting rubber latex with water.

The mixing ratio of the thermoplastic polyester resin and the polyorganosiloxane rubber is 99 to 60 parts by weight of the thermoplastic polyester and 1 to 40 parts by weight of the polyorganosiloxane rubber based on 100 parts by weight of the total of both. If the amount of the polyorganosiloxane-based rubber is too small, the effect of improving the impact resistance is small, and if it is too large, the moldability deteriorates.

The organic silane compound having a specific functional group used in the present invention has at least one RO- (R = R) at a silicon atom having at least one functional group selected from an epoxy group, an isocyanate group and an amino group. (Alkyl group) or a compound to which chlorine is bonded. Specific examples of such organosilane compounds include β
-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane , N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-isocyanopropyltrimethoxysilane, γ-isocyano Propylmethyldimethoxysilane, γ-isocyanopropyltriethoxysilane, γ-isocyanopropylmethyltriethoxysilane and the like.

The amount of the organic silane compound is 0.01 to 10 parts by weight based on 100 parts by weight of the total of the thermoplastic polyester resin and the polyorganosiloxane rubber. If the amount of the organic silane compound is less than 0.01 part by weight, the development of impact strength is not sufficient, and if it exceeds 10 parts by weight, the fluidity during molding is adversely affected.

In the composition of the present invention, the reinforcing filler optionally used includes various reinforcing fillers such as glass fiber, carbon fiber, aramid fiber, metal fiber, asbestos, and whisker. Agents, glass beads, glass flakes, calcium carbonate, talc, mica, aluminum oxide, magnesium hydroxide, boron nitride, beryllium oxide, calcium silicate, clay, metal powder, etc. Natural or synthetic fillers can be mentioned. These are used alone or in combination of two or more.

These fillers have the effect of reinforcing mechanical properties, especially rigidity and heat resistance. Polyester resins containing reinforcing fillers are well known, but the addition of fillers often results in reduced impact resistance. Since the reinforced resin composition of the present invention exhibits good impact resistance and heat resistance stability, the improvement in heat resistance by the reinforcing agent can be effectively utilized. The amount of the reinforcing filler is preferably 300 parts by weight or less based on 100 parts by weight of the total amount of the thermoplastic polyester resin and the polyorganosiloxane rubber.

The composition of the present invention may further comprise, if necessary, a dye or pigment, a stabilizer against light or heat, a known flame retardant such as brominated epoxy, brominated polycarbonate, decabromodiphenyl ether, antimony oxide, a crystal nucleating agent, and various modifications. And a release agent such as a wax and a wax.

In preparing the polyester resin composition of the present invention,
The respective components may be mixed by a known method, and the resin composition can be formed into an arbitrary molded product by a known extrusion method, a molding method, or the like.

〔Example〕

 Hereinafter, the present invention will be described specifically with reference to examples.

The glass fiber used as a filler in the following Examples and Comparative Examples is ESC 03T-828 manufactured by Nippon Glass Co., Ltd.

In each of the reference examples, examples, and comparative examples, “parts” means parts by weight.

Izod impact strength was measured under the following four conditions.

(A) Room temperature impact test Measured at 23 ° C. according to the method of ASTM-D256 (with 1/8 ″ notch).

(B) Low-temperature impact test ASTM-D256 method at -30 ° C (with 1/8 "notch)
It measured according to.

(C) Heat resistance deterioration test In accordance with ASTM D573-32, the molded test piece was heated and held at 120 ° C. for 100 hours with a gear heating tester, and then measured (1/1).
8 "/ with notch).

(D) Weather resistance test Sunshine Long-life Wet Meter
ather Meter; manufactured by Suga Test Instruments Co., Ltd., WEL
-SUN-HC type, black panel temperature 83 ° C, with rainfall), irradiation test of molded test pieces for 300 hours, ASTM-D25
Measured according to 6 (with 1/8 "notch).

Reference Example 1 Production of polyorganosiloxane-based graft copolymer (S-1) 2 parts of tetraethoxysilane and 98 parts of octamethylcyclotetrasiloxane were mixed to obtain 100 parts of a siloxane mixture. 100 parts of the above mixed siloxane was added to 200 parts of distilled water in which 1 part of sodium dodecylbenzenesulfonate and 1 part of dodecylbenzenesulfonic acid were respectively dissolved, and the mixture was preliminarily stirred at 10,000 rpm with a homomixer, and then under a pressure of 200 kg / cm ^2. The mixture was emulsified and dispersed by passing it through a homogenizer three times to obtain an organosiloxane latex. This mixed solution was transferred to a separable flask equipped with a condenser and a stirring blade and heated at 80 ° C. for 6 hours while stirring and mixing.
It was left to cool at 20 ° C. for 20 hours. Next, the pH of this latex was neutralized to 6.9 with an aqueous sodium hydroxide solution to complete the polymerization. The polymerization rate of the obtained polyorganosiloxane rubber was 91.2%, the degree of swelling was 23, and the particle diameter of the polyorganosiloxane rubber was 0.24 μm.

Reference Example 2 Polyorganosiloxane rubber (S-2)
Production of (S-11) A polyorganosiloxane rubber was prepared under the same conditions as in Reference Example 1 except for the conditions shown in Table 1. Table 1 shows the results.

Reference Example 3 Polybutadiene-based graft copolymer (S-1
2) Manufacture of polybutadiene graft copolymer (S-
12) was prepared as follows.

5 In a reaction vessel equipped with a stirrer, add a polybutadiene latex (111A manufactured by Nippon Zeon, polymer content: 50% by weight, average particle size: 0.5%).
3μ) 140 parts, water 70 parts, potassium oleate 2 parts, ferrous sulfate
0.005 parts, sodium pyrophosphate 0.02 parts, dextrose 0.0
3 parts were charged, and a mixture of 21 parts of styrene, 9 parts of acrylonitrile and 0.02 part of cumene hydroperoxide was added dropwise over 2 hours in a water bath at 80 ° C. under stirring in a nitrogen atmosphere, and further stirred at 80 ° C. for 2 hours after completion of the dropwise addition. To complete the polymerization.
To the obtained latex, 1 part of 2,2'-methylenebis (4-methyl-6-t.butylphenol) was added, and the mixture was poured into 500 parts of a 5% aqueous magnesium sulfate solution with stirring to cause coagulation. After being separated and washed, it was dried at 80 ° C. for 10 hours to obtain a dry powder of a polybutadiene-based graft copolymer (S-12).

Reference Example 4 Production of polybutyl acrylate graft copolymer (S-13) For comparison, polybutyl acrylate graft copolymer (S-13) was produced as follows.

5 In a reaction vessel equipped with a stirrer, 140 parts of water, 1 part of sodium dodecylbenzenesulfonate, 0.005 part of ferrous sulfate, 0.015 part of sodium ethylenediaminetetraacetate, 0.05 part of Rongalit
3 parts were charged, and a mixture of 68 parts of butyl acrylate, 2 parts of allyl methacrylate, and 0.1 part of cumene hydroperoxide was added dropwise over 2 hours in a water bath at 80 ° C. with stirring in a nitrogen atmosphere. Thereafter, stirring was continued at 80 ° C. for 1 hour, and styrene 21
Parts, acrylonitrile 9 parts, cumene hydroperoxide
0.05 parts of the mixture were added dropwise over 2 hours. Then 80 ℃
For 1 hour to complete the polymerization. The obtained latex was poured into 500 parts of a 1% aqueous solution of calcium chloride with stirring, coagulated, and the precipitated solid was separated and washed, and dried at 80 ° C. for 10 hours to obtain a polybutyl acrylate graft copolymer ( S-13) was obtained.

Examples 1-3 Melt polymerization of dimethyl terephthalate and 1,4-cyclohexane dimethanol with tetrabutoxy titanate as a catalyst was used to pulverize polycyclohexylene dimethylene terephthalate with [η] = 0.8, and the average particle diameter was 100.
μm. 300 parts of this polyester was charged into 500 parts of a polyorganosiloxane rubber latex (S-1) with stirring to prepare a dispersion. Thereafter, the mixture is coagulated by dropping into 600 parts of a 1% by weight aqueous solution of calcium chloride, separated and washed, dried at 80 ° C. for 10 hours to remove water, and polycyclohexene in which polyorganosiloxane rubber is dispersed is dispersed. A range methylene terephthalate resin composition was obtained.

The above polycyclohexylene dimethylene terephthalate resin composition in which a polyorganosiloxane rubber is dispersed.
To 50 parts, 1 part of a functional group-containing organosilane compound shown in Table 2 was blended with a Henschel mixer, and 50 parts of the same polycyclohexylene dimethylene terephthalate resin ([η] = 0.8) was blended. The mixture was extruded at 300 ° C. using a screw extruder and pelletized. The amount of the polyorganosiloxane rubber in the resin composition constituting the pellet was 20 parts.

The pellets are heated at a cylinder temperature of 300 ° C and a mold temperature of 80 ° C.
To obtain an Izod test piece. Table 2 shows the results of evaluation of the impact strength using this test piece.

Examples 4 to 9 Using the polycyclohexylene dimethylene terephthalate resin in which the polyorganosiloxane-based rubber obtained in Reference Example 1 was dispersed, using the composition shown in Table 2, compounded, extruded, and injected in the same manner as in Example 1. Molding was performed to obtain an Izod test piece. The results of evaluating the impact strength using this test piece are also shown in Table-
It is shown in FIG.

Comparative Examples 1 to 10 For comparison, blending, extrusion, and injection molding were performed in the same manner as in Example 1 with the compositions shown in Table 2, and various test pieces were obtained. The evaluation results are shown in Table 2.

Comparative Example 11 Extrusion was carried out under the same conditions as in Example 1 except that the amount of the organosilane compound was changed to 20 parts.

Examples 10 to 19 The polyorganosiloxane-based rubber obtained in Reference Example 2 was blended in the same manner as in Example 1 with the composition shown in Table 3 and evaluated. Table 3 shows the results.

Examples 20 to 23, Comparative Examples 12 to 15 Instead of polycyclohexylene dimethylene terephthalate resin, polyethylene terephthalate resin (PET)
([Η] = 0.7) and polytetramethylene terephthalate resin (PBT) ([η] = 0.8) were blended, extruded, and injection-molded in the same manner as in Example 1 with the composition shown in Table-4.
Izod specimens were obtained. However, when polytetramethylene terephthalate resin (PBT) was used, the temperature of the injection molding cylinder was set to 250 ° C.

Table 4 shows the results of evaluating the test pieces. For comparison, the results of extruding and molding with the composition shown in Table 4 and conducting an Izod test are also shown in Table 4.

[Effect of the Invention] The thermoplastic polyester resin composition of the present invention has improved impact resistance, and retains good heat resistance, mechanical strength, moldability, fluidity, and the like inherent to the polyester resin. .

Continuation of the front page (56) References JP-A-62-91560 (JP, A) JP-A-64-62349 (JP, A) JP-A-59-149951 (JP, A) JP-A-54-135835 (JP) (A) JP-A-3-74453 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 67/00-67/08 CA (STN) REGISTRY (STN)

Claims (5)

(57) [Claims] 1. A polyorganosiloxane-based resin having (A) 99 to 60 parts by weight of a thermoplastic polyester resin, (B) having an average particle diameter of 0.05 to 0.5 μm and a swelling degree of 3 to 50 measured in a toluene solvent. 1 to 40 parts by weight of rubber, (C) 0.01 to 10 parts by weight of an organic silane compound having at least one functional group selected from an epoxy group, an isocyanate group and an amino group (the above (A) and (B) (D based on the total amount of 100 parts by weight), (D) 0 to 300 parts by weight of the reinforcing filler (the above (A) and (B)
(Based on a total amount of 100 parts by weight). 2. The thermoplastic polyester resin composition according to claim 1, wherein the thermoplastic polyester resin (A) is polyethylene terephthalate or polybutylene terephthalate. 3. The thermoplastic polyester resin composition according to claim 1, wherein the main constituent unit of the thermoplastic polyester resin (A) is cyclohexylene dimethylene terephthalate. 4. The method according to claim 1, wherein the organosilane compound (C) is β- (3,4-
Epoxycyclohexyl) ethyltrimethoxysilane,
γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β
(Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ -Isocyanopropyltrimethoxysilane, γ-isocyanopropylmethyldimethoxysilane,
γ-isocyanopropyltriethoxysilane, or γ
The polyester resin composition according to claim 1, which is -isocyanopropylmethyltriethoxysilane. 5. The polyester resin composition according to claim 1, wherein the polyorganosiloxane rubber (B) contains polydimethylsiloxane as a main component.