JPH02150446A - Thermoplastic polyester resin composition - Google Patents

Abstract

PURPOSE:To provide the subject composition having excellent low temperature impact resistance, weather resistance, heat resistance, appearance, etc., by compounding a specific amount of a specified polyorganosiloxane-polyalkyl (meth)acrylate complex rubber graft copolymer. CONSTITUTION:(A) 95-50wt.% of a thermoplastic polyester (e.g. polyethylene terephthalate), (B) 5-50wt.% of a complex rubber graft copolymer prepared by graft-copolymerizing one kind or more of vinylic monomers to a complex rubber comprising B1: 10-90wt.% of a polyorganosiloxane rubber component having dimethylsiloxane repeating unit in the main skeleton thereof and B2: 90-10wt.% of a polyalkyl (meth) acrylate rubber having n-butyl acrylate repeating units in the main skeleton thereof in an inseparable, mutually entangled structure and having an average particle size of 0.08-0.6mum and (C) 0-60wt.% of a filler are compounded with each other to provide the subject composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermoplastic polyester resin composition having excellent heat resistance, corrosion resistance, and impact resistance.

[Conventional technology]

Thermoplastic polyesters such as boria-kylene terephthalate are known for their excellent mechanical properties, thermal stability, weather resistance,
! Due to its excellent kneading properties, it is 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. A number of 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 very dire. For example, blending diene rubber reinforced resin with thermoplastic polyester improves impact resistance, but conversely heat stability and weather resistance are significantly reduced. On the other hand, when an acrylic rubber-reinforced resin is blended, there is little deterioration in weather resistance, but there is almost no impact resistance improvement effect at low temperatures. Although olefin copolymers are effective in improving impact resistance, they have problems such as deterioration of other mechanical properties, poor dispersibility, and delamination, making them unusable.

[Problem to be solved by the invention]

The inventors of the present invention have conducted intensive studies on a method for improving r# impact resistance while maintaining the excellent heat resistance stability and weather resistance inherent to thermoplastic polyester. We proposed blending a graft copolymer, which is a highly efficient graft polymerization of polymers, into thermoplastic polyester. This system succeeded in improving impact resistance and weather resistance, but as a result of further research by the present inventors, it was completely unexpected that polyorganosiloxane rubber and alkyl (meth)acrylate rubber We have discovered that the impact resistance and appearance of the kit can be greatly improved by using a new composite rubber-based graft polymer, and have arrived at the present invention.

[Means to solve the problem]

The present invention is a thermoplastic polyester (A) of 95 to 50 MIk.
4. Polyorganosiloxane rubber component 10-90 weight Ik
Yuto polyalkyl (meth)acrylate rubber component 90~
10 weight 4 (total amount of these 100 weight t%) has a structure in which they are intertwined with each other so that they cannot be separated, and the average particle size is n, os ~ α6 μm.
Components (A) to (C) contain 5 to 50% by weight of a composite rubber graft copolymer (B) obtained by graft polymerization of more than one type of vinyl monomer, and 0 to 60% by weight of filler (C). ) is a thermoplastic polyester V resin composition blended so that the total amount is 100% by weight.

The resin composition of the present invention not only has excellent heat stability and impact resistance, especially impact resistance at low temperatures, and weather resistance, but also has greatly improved colorability with colorants, and has improved appearance and gloss. It is possible to obtain excellent molded products.

The thermoplastic polyester (A) used in the present invention mainly includes aromatic a) carbonic acids having 8 to 22 carbon atoms and alkylene glycols, cycloalkylene glycols, or aralkylene glycols having 2 to 22 carbon atoms. and may optionally contain a minor amount of aliphatic dicarboxylic acids such as adipic acid and sepacic acid, and polyethylene glycol, polytetramethylene glycol, etc.
It may contain polyalkylene glycols such as.

@Fc Preferred polyesters include polyethylene terephthalate and polytetramethylene terephthalate.

Mixtures of two or more of these thermoplastic polyesters may also be used.

In the present invention, thermoplastic polyester (
The content of A) is 95 to 50% by weight, and a content outside this range is undesirable because it tends to make it difficult to obtain the resin composition targeted by the present invention.

Furthermore, the composite rubber-based graft copolymer (B) used in the present invention refers to the polyorganocloxane rubber component 1.
0 to 90% by weight and 90 to 10% by weight of the polyalkyl (meth)acrylate rubber component (the total amount of each rubber component is 100% by weight)
Weight 1), both rubber components are intertwined with each other and have a structure that is virtually inseparable, and the average particle size is α08
It is a copolymer in which one or more vinyl monomers are graft-polymerized onto a composite rubber having a diameter of ~16 μm.

The characteristics of the resin composition of the present invention cannot be obtained even if one of a polyorganosiloxane rubber component and a polyalkyl (meth)acrylate rubber component or a simple mixture thereof is used as a rubber source instead of the above composite rubber. First, polyorganosiloxane rubber component and polyalkyl (
Only when the meth)acrylate rubber components are intertwined with each other and integrated into a composite body can a resin composition that provides a molded article with excellent impact resistance and molded surface appearance be obtained.

Furthermore, if the polyorganosiloxane rubber component constituting the composite rubber exceeds 90% by weight, the surface appearance of the molded product from the resulting resin composition will deteriorate, and the polyalkyl (meth)acrylate rubber component will exceed 90% by weight. [If you exceed
The impact resistance of molded articles made from the resulting resin composition deteriorates. Therefore, it is necessary that the two rubber components constituting the composite rubber are both in the range of 10 to 90% by weight (however, the total amount of both rubber components is 100% by weight). A range of % by weight is particularly preferred. It is necessary that the average particle diameter of the composite rubber is in the range of α08 to α6 μm. If the average particle size is less than α, 08 times, the impact resistance of the molded product from the resin composition will deteriorate, and if the average particle size exceeds α6 μm, the molded surface appearance of the molded product from the resin composition will deteriorate. becomes worse. Emulsion polymerization is the most suitable method for producing a composite rubber having such an average particle size. First, a latex of polyorganosiloxane rubber is prepared, and then monomers for synthesis of alkyl V (meth)acrylate rubber are prepared. It is preferable to impregnate the rubber particles of the polyorganosiloxane rubber latex with the synthetic monomer and then polymerize the synthetic monomer.

The polyorganosiloxane rubber components constituting the above composite rubber include the organosiloxane and crosslinking agent (1) shown below.
can be prepared by emulsion polymerization using
Furthermore, a grafting agent (1) can also be used in combination.

The organosiloxane includes various cyclic bodies having 3 or more membered rings, and 3- to 6-membered rings are preferably used. For example, hexamethyl V cyclotrisiloxane, octamethyl V cyclotetrasiloxane, decamethyl cyclopentacloxane, dodecamethyl cyclohexane loxane,
Examples include trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, octapheni/L/V clotetraV-loxane, and these may be used alone or in a mixture of two or more. The amount of these used is 50% by weight or more, preferably 70% by weight of the polyo-V ganosiloxane rubber component! JI or above.

Examples of the crosslinking agent (1) include trifunctional or tetrafunctional silane crosslinking agents, such as trimethoxymethylcrane, triethoxyphenylsilane, tetramethoxysilane, tetramethoxysilane, tetra-n-propoxinelan, and tetrabutoxysilane. etc. are used. Particularly preferred are tetrafunctional crosslinking agents, and among these, the present tetraethoxysilane is particularly preferred. The amount of crosslinking agent used is 0.1 to 30% by weight in the polyorganosiloxane rubber component.

Graft cross agent (11 is the following formula % formula %) (In each formula, R1 is a methyl group, ethyl group, propyl group, or phenyl group, R2 is a hydrogen atom or a methyl group, n is 0.
1 or a2. Indicates the number of pa1-6. ) Compounds that can form a unit represented by the following are used.

(Meth)acryloyloxysiloxane that can form the unit of formula (11) has a high grafting efficiency, so it is possible to form an effective surface graft chain and is advantageous in terms of impact resistance development.

Note that methacryloyloxysiloxane is particularly preferred as a unit capable of forming the unit of formula rl-1). Specific examples of methacryloyloxysiloxane include β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxybrobylmethoxyV dimethylsilane, and γ-methacryloyloxyethyldimethoxymethylsilane.
-Methacryloyloxy V-propyl dimethoxymethyl V-lan, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyl V-oxypropylethoxydiethylsilane, γ-methacryloyloxypropyldiethoxymethane, δ-methacryloyloxybutyljethoxymethylsilane, etc. Can be mentioned. The amount of grafting agent used is 0 to 10 in the polyorganosiloxane rubber component.
The weight is ik%.

The latex of this polyorganosiloxane rubber component can be produced using, for example, the methods described in US Pat. No. 2,891,920 and US Pat. No. 3,294,725. In the practice of the present invention, for example, an organosiloxane and a crosslinking agent (1) and optionally a grafting agent (
The mixed solution of 1) in the presence of a sulfonic acid emulsifier such as alkylbenzene sulfonic acid or alkyl V-phonic acid,
For example, it is preferable to manufacture by a method of shear mixing with water using a homogenizer or the like. Alkylbenzenesulfonic acids are suitable because they act as emulsifiers for organosiloxanes and simultaneously act as K14 initiators. On this occasion,
It is preferable to use an alkylbenzene sulfonic acid metal salt, an alkyl M fonic acid metal salt, etc. in combination, since this is effective in maintaining the polymer stably during graft polymerization.

The polyalkyl (meth)acrylate rubber component constituting the above composite rubber can be synthesized using the alkyl V (meth)acrylate shown below, a crosslinking agent (n), and a grafting agent (n).

Examples of the alkyl V(meth)acrylates include alkyl acrylates and hexyl methacrylates such as t-methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate. Examples include alkyl methacrylates such as 2-ethylhexyl methacrylate, 2-ethylhexyl methacrylate, and n-lauryl methacrylate, with preference given to using Intic n-butyl acrylate.

As the crosslinking agent (■), for example, ethylene glycol-v dimethacryly, propylene glycol dimethacryly, 1,3-butylene glycol dimethacryly, 1.
Examples include 4-butylene glycol dimethacrylate.

Examples of the grafting agent (U) include allyl methacrylate, triallyl cyanurate, and triallyl isocyanurate. Allyl methacrylate can also be used as a crosslinking agent. These crosslinking agents and grafting agents may be used alone or in combination of two or more Fi.

The total amount of these crosslinking agents and grafting agents used is α1 to 20 times the polyalkyl (meth)acrylate rubber component! Excellent.

The polymerization of the polyalkyl (meth)acrylate rubber component is
The above alkyl(meth)acrylate, a crosslinking agent and a grafting agent are added to the latex of the polyorganosiloxane rubber component which has been neutralized by the addition of an aqueous solution of an alkali such as hydroxide, potassium hydroxide or sodium carbonate. is added and impregnated into polyorganosiloxane rubber particles, followed by the action of an ordinary radical polymerization initiator. As the polymerization progresses, a crosslinked network of polyalkyl (meth)acrylate rubber is formed that is intertwined with the crosslinked network of polyorganosiloxane rubber, and the polyorganosiloxane rubber component Topolyalky 7L/(meth) is substantially inseparable.
A composite rubber latex with an acrylate rubber component is obtained. In addition, when carrying out the present invention, as this composite rubber, the main skeleton of the polyorganosiloxane rubber component has repeating units of dimethylsiloxane, and the main skeleton of the polyalkyl (meth)acrylate rubber component has repeating units of n-butyl acrylate. A composite rubber having units is preferably used.

The composite rubber prepared by emulsion polymerization in this way is
It can be graft copolymerized with vinyl V monomers, and because the polyorganosiloxane rubber component and polyalkyl V (meth)acrylate rubber component are tightly intertwined, they cannot be extracted and separated using ordinary organic solvents such as acetone and toluene. .

The gel content measured by extracting this composite rubber with toluene at 90° C. for 12 hours is 80% by weight or more, 11% or more.

Vinyl monomers to be graft-polymerized to this composite rubber include aromatic alkenyl compounds such as styrene, α-methylstyrene, and vinyltoluene: methyl methacrylate;
Methacrylic acid esters such as 2-ethylhexyl methacrylate dimethyl acrylate, ethyl acrylate, and acrylic acid esters such as butyl acrylate: various vinyl monomers such as cyanide vinyl V compounds such as acrylonitrile and methacrylonitrile M; These can be used alone or in combination of two or more.

The ratio of the composite rubber to the vinyl monomer in the composite rubber graft copolymer (B) is preferably 30 to 95 parts by weight of the composite rubber based on the weight of the graft copolymer (B). 40-900-90% by weight yarn monoplane 5
~70% by weight, preferably Fi 10-60% by weight. If the vinyl monomer content is less than 5 parts by weight, the graft copolymer (B) will not be sufficiently dispersed in the resin composition;
If it exceeds 0% by weight, it is not preferable because the impact strength development property decreases.

The composite rubber-based graft copolymer (B) is a composite rubber-based graft copolymer latex obtained by adding the above-mentioned vinyl monomer to a composite rubber latex and polymerizing it in one stage or multiple stages using radical polymerization technology. It can be separated and recovered by pouring it into hot water in which a metal salt such as calcium chloride or magnesium sulfate has been dissolved, followed by salting out and coagulation.

In the present invention, the content of the composite rubber graft copolymer (B) in the entire resin composition is 5 to 50% by weight, and if this content is less than 5 parts by weight, low-temperature impact properties are insufficient. . Moreover, if the copolymer (B) exceeds 50% by weight, the heat resistance of the resin composition will decrease, which is not preferable.

As the filler (a), various types and shapes are used, such as glass fiber, carbon fiber, aramid fiber, metal fiber, asbeth, fibrous fillers such as whiskers, glass peas, glass flakes, and carbonic acid. Natural or synthetic fillers in the form of spherical plates or amorphous granules such as V-sium, talc, mica, aluminium oxide, magnesium hydroxide, boron nitride, beryllium oxide, calcium silicate, clay metal powder, etc. It will be done. These fillers (C) have the effect of reinforcing mechanical properties, particularly rigidity and heat resistance, and are used alone or in combination, and their blending ratio is 0 to 60% by weight in the total resin composition. . Although polyester resins containing reinforcing fillers are well known, 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 heat resistance stability, it is possible to effectively utilize the improvement in heat resistance and rigidity provided by the reinforcing agent.

The resin composition of the present invention may optionally contain dyes, pigments, light or heat stabilizers, brominated epoxy, brominated polycarbonate, known flame retardants such as decabromodiphenyl ether and antimony oxide, crystal nucleating agents, and various modifications. There is no problem even if a release agent such as a wax or a mold release agent is contained.

〔Example〕

The present invention will be explained in more detail below with reference to Examples.

Note that "part" hereinafter means "part by weight".

Reference Example 1 Manufacture of composite rubber-based graft copolymer (s-1'l: 2 parts of tetraethoxysilane, 5 parts of r-methacryloyloxypropyldimethoxymethylsilane α, and 97.5 parts of octamethylcyclotetrasiloxane were mixed, and siloxane Add 100 parts of the mixture to 200 parts of distilled water in which 1 part each of sodium dodecylbenzenesulfonate and dodecylbenzenesulfonic acid was dissolved, and mix with a homomixer for 10,000 r.
After pre-stirring at 300 pm with a homogenizer
An organosiloxane latex was obtained by emulsifying and dispersing it at a pressure of 20 kg/an''.The mixture was transferred to a separable flask equipped with a condenser and stirring blades, and heated at 80°C for 5 hours while stirring and mixing. Leave at 4°C
After 8 hours, the pH of this latex was neutralized to 49 with an aqueous IJ solution to complete the polymerization, yielding polyorganosiloxane rubber latex-1f: 94k.

Polymerization rate of polyorganosiloxane rubber j−j
The average particle size of the polyorganosiloxane rubber was 116 μm.

10% of the above polyorganosiloxane rubber latex-1
Collect 0 part, put it in a separable flask equipped with a stirrer, add 120 parts of distilled water, replace with nitrogen, and heat at 50°C.
A mixture of 37.5 parts of n-butyl acrylate, 2.5 m of allyl methacrylate) and 3 parts of tert-butyl hydroperoxide α was charged and stirred for 30 minutes, and this mixture was mixed into a polyorganosiloxane rubber. infiltrated into particles. Then ferrous sulfate Q, 0003 parts, ethylenediaminetetraacetic acid disodium salt aaa1s, Rongarits)
[Prepare a mixture of 7 parts of Ll and 3 parts of distilled water to make Radical V
Polymerization was started and then kept at an internal temperature of 70° C. for 2 hours to complete 5 polymerizations to obtain a composite rubber latex. A portion of this latex was sampled and the average particle size of the composite rubber was measured and found to be α19 μm. Further, this latex was dried to obtain a solid substance, which was extracted with toluene at 90°C for 12 hours, and the gel content was determined to be 9 [13 times]. This composite rubber latex contains 3 parts of ct-butyl hydroperoxide α, 9 parts of acrylonitrile, and 21 parts of styrene.
The mixed solution of the above mixture was added dropwise at 70°C for 45 minutes, and then maintained at 70°C for 4 hours to complete the graft polymerization to the composite rubber. The polymerization rate of the obtained graft copolymer was 9a6. The obtained graft copolymer latex was coagulated by dropping it into calcium chloride 5-layer J14 hot water, separated, washed, and then dried at 75°C for 16 hours to obtain composite rubber-based graft copolymer 8-1. I got it.

Comparative Reference Example Production of Organosiloxane Graft Copolymer C-1,7-Crylate Graft Copolymer 0-2: The above polyorganosiloxane rubber latex-1 was mixed with 23
Collect 3 parts, put in a separable flask equipped with a stirrer, warm to 70°C and stir, and add 3 parts of ferrous sulfate l1ooo.
1 part of ethylenediaminetetraacetic acid disodium salt cLoo,
A mixture of 17 parts of Rongalit α and 3 parts of distilled water was charged, followed by 3 parts of tart-butyl hydroperoxide α.

A mixed solution of 179 parts of acrylonitrile and 21 parts of styrene was added dropwise over 45 minutes, and then maintained at 70°C for 4 hours to complete graft polymerization.

The polymerization rate of the obtained copolymer was 97.51. By dropping this latex into hot water with a chloride power of V sium and 5 parts by weight, the latex was solidified and separated, washed, and heated to 75°C for 1 hour.
After drying for 6 hours, organosiloxane-based graft copolymer 0-1 was obtained.

In addition, as an acrylate-based graft copolymer, 615 parts of n-butyl acrylate and 2.5 parts of allyl methacrylate were used.
A mixture of 1 part and 3 parts of human tθrt-butyl hydroperoxide α was mixed with 2 parts of sodium dodecylbenzenesulfonate.
The solution was emulsified in 200 parts of nine-distilled water, heated to 50°C after purging with nitrogen, and a redox radical V initiator was added to initiate polymerization. After the polymerization of butyl acrylate was completed, 9 parts of acrylonitrile and 21 parts of styrene were added at 70°C.
A mixed solution consisting of 1 part and 3 parts of tart-butyl hydroperoxide α was added dropwise to carry out graft copolymerization. After polymerization, coagulate and wash.

Drying was performed to obtain graft copolymer C-2.

Examples 1-4. Comparative Examples 1 to 3 Various graft copolymers B obtained in Reference Example 1 and Comparative Reference Examples
-1, C-1 and C-2, intrinsic viscosity [η) -7f1.1
0 polytetramethylene terephthalate in the ratio shown in the Ti111 table was supplied to a 3゜φ vented twin screw extruder, melted and kneaded at a cylinder temperature of 230℃,
It was shaped into a pellet shape. After drying the obtained pellet, injection molding was performed at a cylinder temperature of 230°C and a mold temperature of 60°C to obtain various evaluation test pieces. The results of evaluation using these are also shown in Table 1.

Examples 5-9. Comparative Example 4 Polytetramethylene terephthalate (PTMT) having an intrinsic viscosity [η] of 092, polyethylene terephthalate (PI!!T) having an intrinsic viscosity [η] of 185, and the graft copolymer obtained in Reference Example 1 Coalescence 8-1 was 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 formed into a pellet to obtain a composition. These were heated at 240°C for the P'rMT system, and at PI! The iT series was injection molded at 275°C to obtain test pieces for evaluation. These evaluation results are shown in Table 2.

Table Examples 10-11. Comparative Example 5 Polytetramethylene terephthalate having an intrinsic viscosity (V) of α85, graft copolymer s-1, commercially available chopped strand glass fiber with a fiber length of 3 strands, and wollastonite powder with a fiber length of 32.5 mm were used. They were blended in the proportions shown in Table 3, extruded using 2501111 in the same manner as in Example 1, and shaped into a pellet to obtain a supplemented composition.

Using this, a flat plate of 100x100x3 (mash) was injection molded at a cylinder temperature of 250°C and a mold temperature of 8 (Ic).
A falling weight impact test was conducted. The results are shown in Table 3. The composition of the present invention provides good impact resistance. In addition, in terms of weather resistance, the inherent characteristics and properties of Polyester V may be degraded. b0 Table 5 [Effects of the Invention] The present invention uses thermoplastic polyester, specific polyorganosiloxane-polyalkyl/L/(meth)acrylate composite rubber By blending the graft copolymer in the proportions described above, a resin composition with particularly excellent low-temperature impact resistance, as well as excellent weather resistance and heat resistance, can be obtained, resulting in excellent effects.

Patent applicant: Mitsubishi Rayon Co., Ltd. Agent: Patent Attorney Toshio Yoshizawa

Claims (1)

[Claims] 1. 95 to 50% by weight of thermoplastic polyester (A), 10 to 90% by weight of polyorganosiloxane rubber component, and 90 to 10% by weight of polyalkyl (meth)acrylate rubber component (total amount of these 100% by weight) weight%) have a structure in which they are intertwined with each other so that they cannot be separated, and the average particle size is 0.
．． 5 to 50% by weight of a composite rubber graft copolymer (B) obtained by graft polymerizing one or more vinyl monomers to a composite rubber having a diameter of 08 to 0.6 μm, and a filler (
C) 0 to 60% by weight when the total amount of components (A) to (C) is 1
00% by weight. 2. The composite rubber contains a polyorganosiloxane rubber component obtained by emulsion polymerization using an organosiloxane, a crosslinking agent, and optionally a grafting agent, and an alkyl (meth)acrylate, a crosslinking agent, and a polyorganosiloxane rubber component. The thermoplastic polyester resin composition according to claim 1, comprising a polyalkyl (meth)acrylate rubber component obtained by impregnating a grafting agent and then polymerizing the component. 3. The main skeleton of the polyorganosiloxane rubber component has repeating units of dimethylsiloxane, and the main skeleton of the polyalkyl (meth)acrylate rubber component has repeating units of n-butyl acrylate. Thermoplastic polyester resin composition according to item 2. 4. The thermoplastic polyester resin composition according to claim 1, wherein the composite rubber has a gel content of 80% by weight or more as measured by toluene extraction.