JPH0813920B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a thermoplastic resin composition having improved heat resistance and molding heat stability with improved colorability, particularly ethylene-based resin composition.
A graft copolymer resin component obtained by copolymerizing an aromatic vinyl compound and a vinyl cyanide compound in the presence of an α-olefin rubber polymer, a methacrylic acid ester compound, N-cyclohexylmaleimide, and The present invention relates to a thermoplastic resin composition comprising a copolymer resin component obtained by polymerizing a monomer mixture containing a polymerizable vinyl compound, which has improved heat resistance and molding heat stability with improved colorability.

b. Conventional technology Graft obtained by graft-copolymerizing an ethylene-α-olefin rubber polymer such as ethylene-propylene rubber with a monomer mixture containing an aromatic vinyl compound and a vinyl cyanide compound as main components. Copolymer (AES resin),
Alternatively, a copolymer (AS resin) of the graft copolymer (AES resin), an aromatic vinyl compound and a vinyl cyanide compound
A resin composition composed of and (hereinafter simply referred to as a graft copolymer resin) has excellent moldability, molding appearance, impact resistance, heat resistance, mechanical strength, chemical resistance, and the like, and is injection molded and extruded. It is a resin suitable for molding, and since it has no double bond in the main chain of the rubbery polymer, it has a great feature that it is excellent in weather resistance. However, on the other hand, there is a problem that the coloring property is poor.

Therefore, as a method for improving the coloring property of the graft copolymer resin, an invention in which a copolymer containing a methacrylic acid ester compound as a main component is blended with the graft copolymer resin is disclosed in JP-A-57-117557. And Japanese Patent Laid-Open No. 34045/1986. However, such a copolymer containing a methacrylic acid ester compound as a main component has a drawback of low heat resistance. Therefore, since high heat resistance is often an important selection criterion for resins, it is necessary to satisfy both the coloring property and the heat resistance at the same time. Therefore, a copolymer containing the methacrylic acid ester compound as a main component is required. It has become essential to improve the heat resistance.

Conventionally, as a method for improving the heat resistance of the graft copolymer resin, a method has been known in which a part of styrene is replaced with a styrene derivative such as α-methylstyrene or p-methylstyrene to perform copolymerization.

However, in the copolymer containing the methacrylic acid ester compound and the styrene derivative, if the amount of the styrene derivative is increased in order to improve the heat resistance, the molding heat stability is deteriorated, and if the amount of the styrene derivative is decreased, the molding heat stability is decreased. Although the copolymer has good stability, the heat resistance is deteriorated.

c. Problems to be Solved by the Invention As a result of diligent study in view of these points, the present inventors have found that
And (A) a graft copolymer resin component obtained by copolymerizing a monomer mixture containing an aromatic vinyl compound and a vinyl cyanide compound as main components in the presence of the ethylene-α-olefin rubber polymer. (B) a methacrylic acid ester compound and a copolymer resin component obtained by polymerizing a monomer mixture of N-cyclohexylmaleimide and a vinyl compound copolymerizable with them. The present invention has been completed in the light of the fact that the thermoplastic resin composition has good colorability and can improve heat resistance and molding heat stability at the same time.

d. Means for Solving the Problems That is, the present invention provides (A) a total amount of an aromatic vinyl compound and a vinyl cyanide compound of 95 to 65% by weight in the presence of an ethylene-α-olefin rubbery polymer. Graft copolymer resin component obtained by copolymerizing 35% by weight
20% by weight, and (B) methacrylic acid ester compound 30 to 90
From 5 to 80% by weight of a copolymer resin component obtained by polymerizing a monomer mixture consisting of 5% to 50% by weight, N-cyclohexylmaleimide 5 to 50% by weight, and a vinyl compound copolymerizable therewith with 5 to 60% by weight. It is a thermoplastic resin composition.

e. Detailed Description of the Invention Constituent Component (A) Graft Copolymer Resin Component As the graft copolymer resin component used in the present invention, ethylene-propylene copolymer rubber or
In the presence of an ethylene-α-olefin rubbery polymer such as an ethylene-propylene-non-conjugated diene copolymer rubber, a monomer mixture containing an aromatic vinyl compound and a vinyl cyanide compound as main components is copolymerized. A graft copolymer (AES resin) obtained by polymerization or a resin composition comprising the graft copolymer, a copolymer of an aromatic vinyl compound and a vinyl cyanide compound (AS resin) is used.

As the ethylene-α / olefin-based rubber used as the rubbery polymer, it is preferable to use an ethylene-propylene copolymer or an ethylene-propylene non-conjugated diene copolymer, and particularly, the propylene content is
20-55% by weight, Mooney viscosity (ML _{1 + 4} 100 ℃) 15-50,
Those having an iodine value of 0 to 20 are preferable. By using a rubbery polymer in this range, one having more excellent physical properties can be obtained.

The aromatic vinyl compound used as the monomer is styrene, α-methylstyrene, p-methylstyrene and the like, and the vinyl cyanide compound is acrylonitrile, methacrylonitrile and the like. Further, if necessary, a vinyl compound copolymerizable therewith, for example, an alkyl acrylate such as methyl acrylate or methyl methacrylate, an alkyl methacrylate or the like may be used in a slight amount in combination.

As a method for producing the graft copolymer resin component, the AES resin is produced by radical polymerization of the aromatic vinyl compound and vinyl cyanide compound in the presence of the rubbery polymer, or produced by the above method. did. AES
Graft copolymer resin with a mixture of AES resin and AS resin obtained by substituting a part of the resin with AS resin produced by radical polymerization of separately produced aromatic vinyl compound and vinyl cyanide compound It can also be used as a component.

The amount of AS resin that can be substituted as a part of the AES resin is inevitably determined from the amount of rubber in the graft copolymer resin component (A) and the amount of rubbery polymer in the final thermoplastic resin composition. To be done.

The content of the rubbery polymer in the graft copolymer resin component is generally preferably 5 to 65% by weight, particularly 10 to 50% by weight.
It is preferable that The final content of the rubbery polymer in the thermoplastic resin composition is generally 7 to 35% by weight,
In particular, it is preferably 10 to 30% by weight.

The content of the aromatic vinyl compound in the graft copolymer resin component ((A) component excluding the rubbery polymer) is generally 50 to 85% by weight, preferably 55 to 80% by weight. Is good.

Furthermore, the content of the vinyl cyan compound in the graft copolymer resin component is generally 15 to 50% by weight, preferably 20.
~ 45% by weight is good.

The intrinsic viscosity (η) (methyl ethyl ketone, 30 ° C.) of the matrix resin (solvent-soluble component) in the graft copolymer resin component is generally 0.25 to 1, and preferably 0.3 to 0.8.

As the radical polymerization method for producing the AES resin and AS resin, various methods such as emulsion polymerization method, bulk polymerization method, suspension polymerization method and solution polymerization method can be applied.

Further, as a polymerization agent such as a polymerization initiator, a molecular weight modifier, an emulsifier, a dispersion stabilizer and a solvent used in the above-mentioned polymerization method, a generally known polymerization agent can be used.

Specific examples of these polymerization agents include, as a polymerization initiator, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, etc., as a radical polymerization initiator used in a graft reaction in the case of emulsion polymerization. Redox type or persulfate, azobisisobutyronitrile, which is a combination of a representative organic hydroperoxide and a sugar-containing pyrophosphate formulation, a reducing agent represented by a sulfoxylate formulation and the like,
Peroxides such as benzoyl peroxide are used.

In solution, bulk polymerization and suspension polymerization, for example, organic peroxides such as ketone peroxide, dialkyl peroxide, diacyl peroxide, peroxy ester and hydroperoxide are used.

The molecular weight modifier is preferably normal octyl mercaptan, normal dodecyl mercaptan, tershade decyl mercaptan, mercaptans such as mercaptoethanol, terpinolene, dipentene, terpenes consisting of t-terpinene and a small amount of other cyclic terpenes, and chloroform, four. A halogenated hydrocarbon such as carbon chloride can be used.

As the emulsifier, preferably, rosin acid salts such as potassium rosinate and sodium rosinate, sodium oleate, potassium oleate, potassium laurate, sodium laurate, sodium stearate, potassium stearate and the like, potassium salts, sodium lauryl sulfate and the like. Sulfate ester salt of fatty acid alcohol, and alkyl allyl sulfonate such as sodium dodecylbenzene sulfonate.

As the dispersion stabilizer, a combination of tricalcium phosphate and an alkylallyl sulfonate such as sodium dodecylbenzene sulfonate, or polyvinyl alcohol is used.

Examples of the solvent include toluene, ethylenebenzene, methyl ethyl ketone and the like.

The polymerization conditions in the polymerization method are generally 5 to 90 ° C in emulsion polymerization, preferably 50 to 85 ° C, and generally 50 to 180 ° C in other polymerization methods, preferably 80 to 150 ° C.
It can be obtained by carrying out polymerization at a temperature of 1 to 15 hours, preferably 2 to 10 hours.

(B) Copolymer resin component As the copolymer resin component (B) used in combination with the graft copolymer resin component, a methacrylic acid ester compound is 35 to 90% by weight, and N-cyclohexylmaleimide is 5 to 50% by weight. % And copolymerizable therewith, those obtained by polymerizing a monomer consisting of 5 to 60% by weight of a vinyl compound are used, and as the methacrylic acid ester compound used as one component of the monomer, For example, there are methyl methacrylate, ethyl methacrylate, propyl methacrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate and the like. Among these, it is preferable to use methyl methacrylate, and it is recommended to use methyl methacrylate in the copolymer resin component (B).
It should be in the range of 90 to 90% by weight, preferably 40 to 85% by weight. When it is less than this range, the coloring property cannot be improved, and when it is more than this range, the impact resistance becomes poor.

N-cyclohexylmaleimide must be contained in the copolymer resin component in an amount of 5 to 50% by weight, preferably 5 to 40% by weight. If it is less than this range, heat resistance cannot be improved. If it is too much, the impact resistance becomes poor.

In addition, examples of vinyl compounds copolymerizable with these monomers include aromatic vinyl compounds, vinyl cyanide compounds, and acrylic acid ester compounds.

In the copolymerizable vinyl compound, the content of the aromatic vinyl compound is preferably 20 to 80% by weight, more preferably 30 to 70% by weight, and the content of the vinyl cyanide compound is preferably 20 to 80% by weight. %, More preferably 30 to 70% by weight. The presence of the aromatic vinyl compound improves the moldability and color tone, and the presence of the vinyl cyanide compound improves the impact strength.

Styrene is preferred as the aromatic vinyl compound, and acrylonitrile is preferred as the vinyl cyanide compound. It is necessary that the content of these vinyl compounds in the copolymer resin component is 5 to 60% by weight, preferably 10 to 55% by weight. It is difficult to improve sex simultaneously.

As the method for producing the copolymer resin component, a polymerization method similar to the method for producing the graft copolymer resin component, that is, an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, or the like is applied, and any of these methods is applied. May be used.

Further, as a polymerization agent such as a polymerization initiator, a molecular weight modifier, an emulsifier, a dispersion stabilizer and a solvent used in the above-mentioned polymerization method, a generally known polymerization agent can be used.

Specifically, as the polymerization initiator, for producing the thermoplastic resin composition of the present invention, in order to produce the thermoplastic resin composition of the present invention, the graft copolymer resin component (A) and the copolymer resin component ( The blending ratio of B) is 95: 5 to 20:80, preferably 9 by weight.
It should be 0:10 to 30:70, and more preferably 85:15 to 40:60. Therefore, when the amount of the graft copolymer resin component exceeds the above range, the coloring property, which is one of the features of the present invention, is hardly improved. On the other hand, when the content of the graft copolymer resin component is less than this range, the impact resistance becomes low, which is not preferable.

The mixture of the graft copolymer resin component and the copolymer resin component is a reaction mixture after completion of the polymerization, and remains as a solution-solution or a solution-latex, etc., and after mixing the two, the resin composition May be performed, or powder-powder, powder-pellet, after the resin recovery operation
The thermoplastic resin composition of the present invention may be manufactured by mixing both in the form of pellet-pellet or the like.

As a method for kneading the graft copolymer component (A) and the copolymer resin component (B), various extruders, Banbury mixers, kneaders, rolls and the like are used. A preferable kneading method is a method using an extruder.

The mixing temperature is the graft copolymer resin component (A) to be mixed.
And a temperature not lower than the melting point of the copolymer resin component (B) is required, and it is generally preferably 150 to 300 ° C, and particularly preferably 200 to 280 ° C.

When using the thermoplastic resin composition of the present invention, it is possible to use fillers such as glass fiber, carbon fiber, metal fiber, glass beads, arabest, wollastonite, calcium carbonate, talc and barium sulfate, alone or in combination. it can. Among these fillers, glass fibers and carbon fibers preferably have a fiber diameter of 6 to 60 μm and a fiber length of 30 μm or more.

These fillers are preferably contained in an amount of 5 to 15 parts by weight based on 100 parts by weight of the thermoplastic resin composition.

Further, known additives such as flame retardants, antioxidants, plasticizers, colorants and lubricants can be added and used. Preferred flame retardants and antioxidants are phosphorus compounds.

Other polymers, for example, depending on the performance required,
Polyethylene, polypropylene, BR, NBR, SBR, SB
-S block copolymer, hydrogenated SBS, polystyrene, HIPS, AES resin, polysulfone, polyether sulfone, NBS, methyl methacrylate-styrene copolymer,
An S-I-S block copolymer polyimide, PPS, polyetheretherketone, vinylidene fluoride polymer, etc. may be appropriately blended.

The thermoplastic resin composition of the present invention is generally molded into various molded articles by injection molding, sheet extrusion, vacuum molding, profile molding, foam molding or the like.

The various molded articles obtained by the above-mentioned molding method can be used for exterior parts, interior members of automobiles, various parts and housings related to electric / electronic devices by utilizing their excellent properties.

f. Examples Hereinafter, the present invention will be described in more detail with reference to Examples, but these are merely examples and do not limit the content of the present invention.

In the following examples, parts and% indicate parts by weight and% by weight, respectively.

The graft copolymer resin component and the copolymer resin component used in the examples were produced by the following method.

Production of Graft Copolymer Resin Component (A) <AES Resin> Iodine number 15, which was previously made into a uniform solution state, in a stainless steel autoclave with an internal volume of 50 l equipped with a ribbon type stirring blade,
Mooney viscosity 42, 5-ethylidene-2 as diene component
-FPDM containing norbornene (JSR manufactured by Japan Synthetic Rubber Co., Ltd.)
EP22) 35 parts by weight, styrene 45.5 parts by weight, toluene 180 parts by weight, and tertiary dodecyl mercaptan 0.05 parts by weight are charged and heated with stirring, and acrylonitrile is heated at 50 ° C.
19.5 parts by weight, benzoyl peroxide 0.5 parts by weight, dicumyl peroxide 0.1 parts by weight were added, and the temperature was further raised, and after reaching 80 ° C, polymerization was carried out at 100 rpm with stirring while controlling the temperature at 80 ° C constant. Let the reaction take place. 6 after starting the reaction
It took 1 hour from the time point, the temperature was raised to 120 ° C., and the reaction was further continued for 2 hours to complete the reaction. The polymerization rate was 97%.

After cooling to 100 ° C., 0.2 parts by weight of 2,2′-methylene-bis (4-methyl-6-t-butylphenol) was added, and then the reaction mixture was taken out from the autoclave to remove most of the unreacted water by steam distillation. After distilling off the monomer and the solvent and finely pulverizing, the volatile matter was substantially distilled off with a 40 mmφ vent extruder (220 ° C.> 700 mmHg vacuum), and the polymer was recovered as pellets.

<ABS resin> Polybutadiene (JSR BR71 manufactured by Japan Synthetic Rubber Co., Ltd.) is used in place of the ethylene-α-olefin rubber polymer, and ABS resin of polybutadiene: styrene: acrylonitrile = 35: 45.5: 19.5 (weight ratio). Got

<AS resin> Manufacture of copolymer resin component (B) <Polymer No. 1> Methyl methacrylate prepared in advance as a uniform solution in a stainless steel autoclave with an internal volume of 50 l equipped with a ribbon-type stirring blade.
55 parts by weight, N-cyclohexylmaleimide 20 parts by weight, styrene 18 parts by weight, acrylonitrile 7 parts by weight, toluene
30 parts by weight and 0.3 parts by weight of tertiary dodecyl mercaptan were charged, the temperature was raised with stirring, and 0.1 part by weight of dicumyl peroxide was added at 50 ° C. Further raise the temperature to 120
After reaching ℃, stirring rotation speed 1 while controlling at 120 ℃ constant
The reaction was carried out at 00 rpm for 5 hours. The polymerization yield was 90%. The subsequent treatment was performed in the same manner as in the production of the AES resin to obtain a polymer.

<Polymer No. 2> After the inside of the stainless steel reactor with a stirrer was replaced with nitrogen, 200 parts by weight of ion-exchanged water and 2 parts by weight of sodium dodecylbenzenesulfonate were added in a nitrogen stream, and methyl was added while stirring. 75 parts by weight of methacrylate, 10 parts by weight of N-cyclohexylmaleimide, 10 parts by weight of stainless steel, 5 parts by weight of acrylonitrile, 0.2 part by weight of tertiary dodecyl mercaptan, 0.4 part by weight of sodium formaldehyde sulfonate dihydrate, 0.2 part by weight of sodium ethylenediaminetetraacetate, Add 0.005 parts by weight ferrous sulfate and 0.3 parts by weight cumene hydroperoxide. While continuing stirring, the polymerization reaction was carried out at 70 ° C. for 4 hours. The polymerization yield at this time was 96%. After coagulation using an aqueous solution of calcium chloride, dehydration and drying were performed to obtain a polymer.

<Polymer No. 3> A polymer was prepared in the same manner as the above (Polymer No. 2) except that 45 parts by weight of methyl methacrylate, 10 parts by weight of N-cyclohexylmaleimide, 30 parts by weight of styrene and 15 parts by weight of acrylonitrile were used. Obtained.

<Polymer No. 4> A polymer was prepared in the same manner as in (Polymer No. 2) except that 50 parts by weight of methyl methacrylate, 35 parts by weight of N-cyclohexylmaleimide, 10 parts by weight of styrene and 5 parts of acrylonitrile were used. Obtained.

<Polymer No. 5> 55 parts by weight of methyl methacrylate, 20 parts by weight of N-cyclohexylmaleimide, 18 parts by weight of styrene, 7 parts by weight of acronitrile, 30 parts by weight of toluene, and 0.2 parts by weight of tertiary dodecyl mercaptan were charged and heated. A polymer was obtained in the same manner as in the above <Polymer No. 1> except that the temperature was controlled to be constant at 140 ° C after reaching 140 ° C.

<Polymer No. 6> Polymer in the same manner as in <Polymer No. 1> except that 55 parts by weight of methyl methacrylate, 3 parts by weight of N-cyclohexylmaleimide, 13 parts by weight of acrylonitrile, and 29 parts by weight of styrene were used. Got

<Polymer No. 7> In the same manner as in <Polymer No. 2> above except that 25 parts by weight of methyl methacrylate, 20 parts by weight of N-cyclohexylmaleimide, 40 parts by weight of styrene, and 15 parts by weight of acronitrile were used. Got united.

<Polymer No. 8> A polymer was obtained in the same manner as in the above <Polymer No. 2> except that 80 parts by weight of methyl methacrylate and 20 parts by weight of N-cyclohexylmaleimide were used.

<Polymer No. 9> Polymer in the same manner as in <Polymer No. 2> except that 25 parts by weight of methyl methacrylate, 60 parts by weight of N-cyclohexylmaleimide, 10 parts by weight of styrene, and 5 parts by weight of acrylonitrile were used. Got

<Polymer No. 10> 55 parts by weight of methyl methacrylate, α-methylstyrene
A polymer was obtained in the same manner as in the above <Polymer 2> except that 30 parts by weight, 10 parts by weight of styrene and 5 parts by weight of acrylonitrile were used.

<Polymer No. 11> 55 parts by weight of methyl methacrylate, 25 parts by weight of styrene,
<Polymer except for 20 parts by weight of acrylonitrile
A polymer was obtained in the same manner as in No. 2>.

<Polymer No. 12> A polymer was obtained in the same manner as in the above <Polymer No. 1> except that N-phenylmaleimide was used instead of N-cyclohexylmaleimide.

Example AES resin AS resin pellets obtained by the above method and the pellets of copolymer (B) were blended according to the composition shown in Table 1 to obtain 40
The mixture was melt-kneaded with an mmφ extruder (250 ° C.) to obtain a thermoplastic resin composition as shown in Table 1.

Using this thermoplastic resin composition, a 90TON injection molding machine (250
The test piece was molded at (° C.) and its physical properties were measured. Further, the obtained thermoplastic resin composition was blended in the following blending amount, and colored pellets were obtained through an extruder. It was further molded to obtain a color tone evaluation plate. Regarding the coloring property of the black compound, the lightness was measured with a color difference meter, and the Munsell color value (the larger the value, the worse the coloring property). For other color formulations, the saturation was measured visually.

Black resin 100 Carbon black 0.5 Ca stearate 0.3 Red resin 100 Bengala 1.0 Ca stearate Blue 0.5 Resin 100 Ultramarine blue 1.0 Stearate Ca 0.5 For weather resistance, after irradiating with a sunshine weatherometer for 1000 hours, Izod The impact value was measured. The results are shown in Table 1.

The physical properties in Table 1 were measured by the following methods.

MFR: ASTM D-1238 240 ℃ 10kg / cm 2 Izod impact strength: ASTM D-256-56 (cross section 1/4 × 1/2 inch notched) weatherability: sunshine weatherometer conditions black panel temperature 63 ° C. rainfall Cycle 18 minutes / 120 minutes Izod impact strength-ASTM D-256-56 (Cross section 1/8 x 1/2 inch, notch) AS resin: Styrene-acrylonitrile copolymer Mitsui Toatsu LITAC-A 120PC ABS resin : JSR ABS 10 manufactured by Japan Synthetic Rubber Co., Ltd. Molding thermal stability: 3.5 oz injection molding machine 260 ° C. × 15 minutes presence / absence of silver streak on the surface of molded products Thermoplastic resin compositions prepared according to Examples 1 to 6 Then
The same blackness and saturation as those of the ABS resin alone shown in Comparative Example 9 were obtained.

In Comparative Example 1, the heat resistance cannot be improved because the amount of N-cyclohexylmaleimide is small. Comparative Example-
In No. 2, the coloring property was poor because the amount of methyl methacrylate was small, and in Comparative Example-3, impact strength was low because no vinyl monomer other than the methacrylic acid ester compound and N-cyclohexylmaleimide was used. Furthermore, Comparative Example-4
Has a large amount of N-cyclohexylmaleimide and a small amount of methacrylic acid ester compound, and therefore has poor impact strength and colorability. Further, in the thermoplastic resin compositions of Comparative Examples 5 and 6, N
-If cyclohexylmaleimide is not used, the colorability is good, but the heat resistance and molding heat stability are low.

g. Effect of the Invention The thermoplastic resin composition of the present invention is a thermoplastic resin composition having an excellent balance of colorability, heat resistance and molding thermal stability, as has been clarified in the above Examples and the like. The thermoplastic resin composition of the present invention, which is an excellent material, is molded into various molded articles by injection molding, extrusion molding, etc.,
It can be used for exterior and interior members of automobiles, various parts and housings related to electric and electronic devices, and is industrially extremely useful.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A 61-91239 (JP, A) JP-A 61-204255 (JP, A) JP-A 61-101547 (JP, A) JP-A 61- 174248 (JP, A)

Claims (1)

[Claims] 1. A copolymer of an aromatic vinyl compound and a vinyl cyanide compound in a total amount of 95 to 35% by weight in the presence of 5 to 65% by weight of (A) an ethylene-α-olefin rubber polymer. 95 to 20% by weight of the resulting graft copolymer resin component, (B) a methacrylic acid ester compound 30 to 90% by weight, N-
Thermoplastic resin composition comprising 5 to 80% by weight of a copolymer resin component obtained by polymerizing a monomer mixture comprising 5 to 50% by weight of cyclohexylmaleimide and 5 to 60% by weight of a vinyl compound copolymerizable therewith .