JPH02294347A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in resistance to heat distortion and chemicals, suitable for various kinds of automotive parts, etc., by blending a styrene-based polymer, specific graft copolymer, etc., at specified amounts, respectively. CONSTITUTION:The objective composition can be obtained by blending (A) 40-90wt.% of a styrene-based polymer (e.g. a copolymer from an aromatic vinyl monomer, vinyl cyanide monomer and another vinyl monomer copolymerizable therewith), (B) 5-60wt.% of a graft copolymer prepared by graft polymerization, in the presence of B1: 5-95 pts.wt. of a rubbery polymer, of B2: 95-5 pts.wt. of a vinyl monomer, and (C) 5-55wt.% of a polybutylene terephthalate resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermoplastic resin composition with improved heat deformation resistance and chemical resistance. [Conventional technology] ABS resin, ABSt! Styrenic resins such as heat-resistant ABSFM resins in which part or all of the styrene in the T fat is replaced with α-methylstyrene (hereinafter referred to as [αMSt]) have a good balance of physical properties such as heat deformation resistance, impact resistance, and processability. Because it has relatively good properties, it is used in a wide range of fields such as automobile exterior parts, home appliances, and miscellaneous goods. (Problem to be solved by the invention) However, the conventional styrene resins described above still do not have sufficient heat deformation resistance and are poor in chemical resistance. It is common practice to improve the heat deformation resistance and chemical resistance of styrenic resins by introducing copolymerized monomers.In addition, in recent years, different types of polymers have been blended to achieve synergistic effects. Research on so-called polymer alloys, which exhibit new physical properties through the use of polymer alloys, etc., has been actively conducted, and many of them have been put into practical use. As a result of investigation, styrenic polymer and
We have found that a polymer alloy consisting of a specific graft copolymer and polybutylene terephthalate resin (hereinafter referred to as "rPBT resin") has excellent heat deformation resistance and chemical resistance. The present invention was made based on this knowledge, and its purpose is to provide a thermoplastic resin composition that has excellent heat deformation resistance and chemical resistance. [Means for Solving the Problems] The thermoplastic resin composition according to the present invention for achieving the above object contains 40 to 90% by weight of a styrenic polymer (A) and 5 to 90% by weight of a rubbery polymer (P). 95 to 5 parts by weight of vinyl monomer (Q) in the presence of 95 parts by weight (however, (p) and (Q)
) is a graft copolymer (B) obtained by graft polymerization of 100 parts by weight in total, 5 to 60% by weight, and a polybutylene terephthalate resin (C) of 5 to 55% by weight (however,
The total amount of (A), (B) and (C) is 100% by weight). Examples of the styrenic polymer (A) include PS (polystyrene), H[PS (high impact polystyrene),
AS resin (acrylonitrile-styrene copolymer resin),
Examples include ABS resin (acrylonitrile-butadiene-styrene copolymer resin), AAS resin (acrylonitrile-acrylic acid ester-styrene copolymer resin), and AES resin (acrylonitrile-olefin-styrene copolymer resin), which have a good balance of physical properties. In order to
It is preferable to use resin. The above AS resin contains 40 to 90% by weight of aromatic vinyl monomer, 10 to 40% by weight of vinyl cyanide monomer, and 0 to 30% by weight of other copolymerizable vinyl monomers (these three types The vinyl monomers are obtained by copolymerizing 100% by weight in total. In addition, the above ABS resin is composed of 10 to 40 weight % of vinyl cyanide monomer, 40 to 90 weight % of aromatic vinyl monomer, and other copolymer in the presence of 10 to 80 parts by weight of polybutadiene rubber. It can be obtained by graft copolymerizing 90 to 20 parts by weight of a mixture consisting of 0 to 30% by weight of possible vinyl monomers (the total amount of these three vinyl monomers is 100% by weight). AA above
S resin and AES#A resin each use acrylic rubber and EPDM (a three-component copolymer consisting of ethylene, propylene, and Jen) instead of polyptadiene rubber. Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, and pt-butylstyrene. The preferred blending amount of the aromatic vinyl monomer is 40 to 90
Weight%. If it is less than 40% by weight, processability will decrease, and if it exceeds 90% by weight, chemical resistance and impact resistance will decrease. In addition, when heat deformation resistance is particularly required, it is preferable to use a part or all of α-methylstyrene as the aromatic vinyl monomer. Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, and fumaronitrile. The preferred blending amount of the vinyl cyanide monomer is 10 to 4
It is 0% by weight. If it is less than 10% by weight, chemical resistance and impact resistance will decrease, and if it exceeds 40% by weight, thermal stability during molding will decrease and coloration due to heating will become severe. Other copolymerizable monomers include acrylic acid alkyl ester monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, and octyl acrylate;
Methacrylic acid alkyl ester monomers such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride or their anhydrides, maleimide, methyl maleide, phenyl maleimide, cyclohexyl maleimide ,
Maleimide compounds such as N-alkylmaleimides are exemplified. Among these, 1 to 10 weight of unsaturated carboxylic acids or their anhydrides such as acrylic acid, methacrylic acid, and maleic anhydride, which have the effect of improving compatibility between As resin and PBT resin and improving impact resistance. It is preferable to use approximately %. If 1% by weight is ungrooved, the effect of improving the impact resistance is small. If it exceeds 1% by weight, the impact resistance may actually decrease. The graft copolymer (B) contains a vinyl monomer (Q) that can be graft-polymerized in the presence of a rubbery polymer (P),
Obtained by graft polymerization. The rubbery polymer (P) is not particularly limited, but diene rubbers such as polybutadiene rubber, butadiene-styrene copolymer rubber, acrylonitriloptadiene copolymer rubber, acrylic rubber, EPDM, etc. can be used. In addition, when using a diene rubber, it is preferable that the diene component is 50% by weight or more.

In the present invention, the blending ratio of the rubbery polymer (P) and the vinyl monomer (Q) is 5:95 to 95 by weight.
:5. If it is outside the above range, the impact resistance will decrease. Examples of the graft polymerizable vinyl monomer (Q) include aromatic vinyl monomers, vinyl cyanide monomers, acrylic esters, methacrylic esters, unsaturated carboxylic acids and their anhydrides. , maleimide compounds are exemplified, and specifically, the same compounds as those already mentioned in the explanation of the styrenic polymer (A) can be used. A preferable composition of the graft-polymerizable vinyl monomer (0) includes 20 to 80% by weight of aromatic vinyl monomer, 10 to 40% by weight of vinyl cyanide monomer, and other copolymers. An ABS-based graft copolymer with a possible vinyl monomer content of 0 to 30% by weight, an aromatic vinyl monomer of 10 to 50% by weight, and a methacrylic acid alkyl ester monomer of 50 to 90% by weight. An example thereof is an MBS (alkyl methacrylate-butadiene-styrene) M graft copolymer containing 0 to 30% by weight of other copolymerizable vinyl monomers. The PBT resin (C) is a polycondensate of terephthalic acid and 1,4-butanediol. In addition, isophthalic acid, adipic acid, sebacic acid, etc. may be included as other acid components, provided that the ratio of terephthalic acid in the acid component is 80 mol % or more. In addition, other diol components such as ethylene glycol, brobylene glycol, and 1.6-hexane diol may be included, provided that the ratio of 1.4-butanediol in the diol component is 80 mol% or more. Good too. In the present invention, the blending ratio of the styrenic polymer (A), graft copolymer CB), and PBT resin (C) is 40 to 90% by weight of the styrenic polymer (A), and 40 to 90% by weight of the graft copolymer (C). B) 5-60% by weight, PBT resin (C
) 5 to 55% by weight ((A) (B) (C) is 1 in total
00% by weight]. If the amount of PBTWi fat (C) is less than 5 parts by weight, blending effects regarding processability, chemical resistance, etc. will not be expressed;
If it exceeds 5 parts by weight, the heat deformation resistance, particularly under high loads, will decrease, both of which are unfavorable. The above styrenic polymer (A) and graft copolymer CB
) is preferably produced by emulsion polymerization, but other production methods can also be used. For example, various polymerization methods such as bulk polymerization, suspension polymerization, solution polymerization, and combinations thereof, ie, emulsion suspension polymerization and bulk suspension polymerization, can be used. The above emulsion polymerization may be carried out by any conventionally used method. That is, the various monomers described above may be polymerized in an aqueous solvent in the presence of a radical polymerization initiator. In this case, each monomer may be added after mixing, or each monomer may be added separately, if necessary. Further, when adding the monomer to the reaction system, the entire amount may be charged in advance, or the monomer may be added sequentially.

In particular, when α-methylstyrene is used, if all or part of the α-methylstyrene is added first and the remaining monomer mixture is added sequentially, it is possible to It is possible to produce a combination. Examples of emulsion cuts used in emulsion polymerization include fatty acid soaps such as sodium laurate, sodium oleate, sodium balmitate, and potassium stearate, sodium alkylsulfosuccinate, and sodium alkylbenzenesulfonate. , sodium alkyl sulfate, etc. When copolymerizing acidic monomers such as acrylic acid and methacrylic acid, it is not preferable to use fatty acid soap as an emulsifier. In this case, sodium alkylsulfosuccinate, sodium alkylbenzenesulfonate or sodium alkylsulfate is preferred. Examples of the radical polymerization initiator include water-soluble or oil-soluble peroxides such as potassium persulfate, ammonium persulfate, cumenehydroperoxide, and paramenthanhydroperoxide.

The polymerization degree iPl moderating agent may be appropriately selected from those commonly used in emulsion polymerization.

Conventionally known methods can be used to recover resin powder from latex obtained by emulsion polymerization.
For example, acids such as hydrochloric acid, sulfuric acid, acetic acid, etc. are added to latex, and
After coagulating the latex by adding a water-soluble metal salt such as calcium chloride, magnesium chloride, or magnesium sulfate, it may be dehydrated and dried. The styrenic polymer (A) and the graft copolymer (B) may be coagulated and dehydrated separately, or they may be blended in a latex state and then coagulated and dehydrated at the same time. In addition, as another polymerization method, in the presence of latex polymerized with graft copolymer (B), styrenic polymer (A
) is also possible by a one-step method of polymerizing the monomers that constitute the compound. In the production of the thermoplastic resin composition according to the present invention, the styrenic polymer (A), the graft copolymer (B) and the PB
The blend of T resin (C) is, for example, a styrene polymer (
The blend latex of A) and the graft copolymer (B) is coagulated and dehydrated to obtain a blend (blend), and then this blend and the PBT resin (C) are blended in a blender such as a Henschel mixer. It can be melted and kneaded in an extruder. In addition, when blending the above, if necessary,
Additional functionality may be imparted to the thermoplastic resin composition of the present invention by appropriately adding stabilizers, fillers, fillers, etc. (Examples) The present invention will be described in detail based on Examples below, but the present invention is not limited to the Examples below, and can be practiced with appropriate modifications within the scope of the gist. It is something.

In the following, "parts" represent parts by weight, and "%" represent percentages by weight. ■Production of styrenic polymer (A) A reactor equipped with a nitrogen inlet and a monomer inlet is equipped with a stirrer, a reflux condenser, and a thermometer, and the following substances are charged into the reactor. After raising the temperature to 60°C under a nitrogen stream while stirring with a stirrer, the vinyl monomer shown in Table 1, t-dodecylbutane (hereinafter referred to as
rtDM”. ! A mixture (A-1 to A-6 and a-1) containing cumenehydroperoxide (hereinafter referred to as [CHP]) in the weight parts shown in the same table was continuously heated for 6 hours. It was dripped. After dropping, the temperature is 60°C.
Stirring was continued for another hour to complete the polymerization, producing a styrenic polymer (A).
...-...200 parts Sodium formaldehyde sulfoxylate...0.3
Part ferrous sulfate −・・・−・0.002
5 parts Sodium ethylenediaminetetraacetate...0.01 part Sodium alkylbenzenesulfonate...1.-
However, in Table 1, for A-1, 75 parts of α-methylstyrene (hereinafter referred to as “αMStJ) and 0.4 parts of tDM
The sample was prepared in advance in a reaction vessel. (The following is a blank space) ■Production of graft copolymer (B) The following substances were charged into the same birch reaction vessel as used above, and the materials were heated for 60 minutes under a nitrogen stream while stirring.
After raising the temperature to ℃, the vinyl monomer shown in Table 2, t-
Dodecyl mercabutane (hereinafter referred to as rt DMJ)
A mixture (B-1) containing cumenehyde peroxide (hereinafter referred to as rcHP) in the weight parts shown in the same table.
-8-3) was added dropwise continuously over a period of 5 hours. After the dropwise addition was completed, the temperature was maintained at 60°C and stirring was continued for an additional hour to complete the polymerization, producing a graft copolymer (B). water
・・・・・・・・・ 2
50 parts Sodium formaldehyde sulfoxylate 0.3 parts Ferrous sulfate - 0.002
5 parts Sodium ethylenediaminetetraacetate μm 1 A latex-like product with a gel content of 90% by weight was used. (Hereinafter, blank space) 0.01 part Polyptadiene ・・・・・ Predetermined amount shown in Table 2 Note that as polybutadiene, the average particle size is 0.25 ■ Styrenic polymer (A) and graft copolymer (B) The styrenic polymer (A) produced in the above ① and the graft copolymer (B) produced in the above ② were mixed in a latex state at the predetermined ratio shown in Table 3, and phenol was added to the mixture. A blend of the styrenic polymer (A) and the graft copolymer (B) is obtained by adding a styrene-based antioxidant, followed by coagulation with magnesium, dehydration, washing with water, and drying.
D-1 to D-6) were produced. (Hereinafter, blank spaces) ■ Production of thermoplastic resin (D) Compounds (D-1 to D-6) consisting of the styrenic polymer (A) and graft copolymer (B) produced in (■) above, PBT resin (C) was blended with the predetermined weight ratio shown in Table 4, pelletized using a vented extruder, and a test piece (E-1) of thermoplastic resin CD was prepared using an injection molding machine.
~E-1, e-1 and e-2) were produced. ■Measurement of heat distortion temperature, Izod impact strength, and rupture time For each test piece prepared in ① above, the heat distortion temperature, Izod impact strength, and rupture time, which are indicators of chemical resistance, were measured using the measurement method shown below. The time was measured. <Heat distortion temperature> Based on ASTM D-648, load 4.6 kg/
The heat distortion temperature (°C) was measured for each case of CD and load of 18.6 kg/cj. Measuring method of Izont impact strength> Izont impact strength (kg-c+s/cm) was measured in accordance with ASTM D-256 (with 1/4 inch notch, ambient temperature 23°C). <Chemical resistance> After fixing both ends of the dumbbell and applying stress to the center so that the strain is 1%, dioctyl phthalate (DOP)
) was dropped, the time until the dumbbell broke was measured, and the chemical resistance was evaluated according to the following criteria. ◎: 24 hours or more o: 10 to 24 hours X: Qt time Table 4 shows the above measurement results. (Hereinafter, blank space) As is clear from Table 4, the example samples E-1-E-7 of the thermoplastic resin composition according to the present invention have high heat deformation resistance,
It is clear that this plastic molding material has excellent impact resistance and chemical resistance, and has an excellent balance of physical properties. On the other hand, comparative sample e
-1 and e-2 both had extremely poor Izod impact strength or chemical resistance. In particular, comparative sample e-2 has a heat deformation resistance of 75°C under high load.
This is extremely bad, and poses a practical problem when used as a plastic molding material for automobile parts, etc. (Effects of the Invention) As explained in detail above, when the thermoplastic resin composition according to the present invention is used as a plastic molding material and is molded by various molding methods such as injection molding, extrusion molding, blow molding, and compression molding, various The present invention has excellent effects, such as making it possible to obtain plastic molded products with excellent heat deformation resistance and chemical resistance, which are suitable for use as automobile parts, mechanical parts, electrical/electronic parts, etc.

Claims (1)

[Scope of Claims] 1. 95 to 5 parts by weight of vinyl monomer (Q) in the presence of 40 to 90 parts by weight of styrenic polymer (A) and 5 to 95 parts by weight of rubbery polymer (P) (However, (P) and (Q) are 100 parts by weight in total) 5-60% by weight of graft copolymer (B) obtained by graft polymerization, and 5-55% by weight of polybutylene terephthalate resin (C)
(However, the total amount of (A), (B) and (C) is 100% by weight). 2. The styrenic polymer (A) is composed of an aromatic vinyl monomer, a vinyl cyanide monomer, and a vinyl monomer copolymerizable with these two types of vinyl monomers. The thermoplastic resin composition according to claim 1, which is a copolymer. 3. The styrene polymer (A) contains an aromatic vinyl monomer, a vinyl cyanide monomer, a vinyl monomer having a functional group, and a combination of these three vinyl monomers. The thermoplastic resin composition according to claim 1, which is a copolymer with a polymerizable vinyl monomer. 4. The thermoplastic resin composition according to claim 3, wherein the vinyl monomer having a functional group is methacrylic acid and/or acrylic acid. 5. The thermoplastic resin composition according to any one of claims 2 to 4, wherein the aromatic vinyl monomer is styrene and/or α-methylstyrene.