JP2992069B2 - Heat resistant ABS resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat-resistant ABS resin composition having improved processability and thermal stability, and more particularly to a maleimide or α-methylstyrene-modified ABS resin. The present invention relates to a heat-resistant ABS resin composition containing an aromatic polyester compound.

[Problems to be solved by conventional technology and invention]

Maleimide or α-methylstyrene-modified ABS resin has excellent heat resistance (heat deformation temperature) characteristics, and because it has an excellent balance of impact resistance and fluidity, the same molding process as ABS resin It has features that are not found in conventional styrene-based resins and engineering plastics, such as its ability to be used in secondary processing, and is expected to be used in a wide range of applications such as automotive parts, electrical industrial parts, and office machines. .

However, although the heat resistance is improved by introducing a maleimide or α-methylstyrene component,
There is a disadvantage that the fluidity in the mold during processing is significantly reduced. For this reason, lubricants such as higher fatty acid metal salts or higher fatty acid amides have been used, but conventionally used lubricants are not only insufficient in their effect, but the surface properties of molded articles are extremely poor, Alternatively, there is a disadvantage that the heat distortion temperature of the resin is lowered, and this is not satisfactory in practical use.

In addition, as the heat resistance of the heat-resistant ABS resin increases, the processing temperature must be 260 ° C or higher, which is higher than that of the conventional ABS resin, and the resin temperature rises inside the processing machine due to the decrease in workability (fluidity). In addition, there is also a disadvantage that the thermal oxidation deterioration of the resin becomes remarkable.

It has also been proposed to add various antioxidants for the purpose of preventing thermal oxidation deterioration of the heat-resistant ABS resin.
3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate (JP-A-62-45643) or 3-tert-butyl-4-hydroxy-5-methylphenylpropionate (JP-A-62-181352 and JP-A-62-220544) or a bis (2,6-di-tert-butyl-4-alkylphenyl) pentaerythritol diphosphite compound Japanese Patent Application Laid-Open No. 63-254157) has been proposed, but the effect of preventing thermal oxidative deterioration is not completely satisfactory because the processability is not improved, and is not practically satisfactory. Was.

JP-A-56-67351 proposes to use an aromatic low-polymerization degree polyester in order to improve the processability of a normal ABS resin. There is no description suggesting that it can be applied to the ABS resin, much less the specific aromatic low polymerization degree polyester of the present invention, which is a terephthalic acid low polymerization degree polyester, lowers the heat distortion temperature of the heat-resistant ABS resin. There is no description suggesting that not only the flowability can be improved without also performing the treatment but also the surface property is remarkably improved.

[Means for solving the problem]

The present inventors have conducted intensive studies in view of the present situation, and found that maleimide-modified or α-methylstyrene-modified ABS
By adding a specific aromatic low-polymerization degree polyester to the resin, not only can the flowability of the heat-resistant ABS resin during processing and molding be remarkably improved, but also the surface properties of the molded product are good, and the heat distortion temperature Was also found to hardly decrease.

In addition, the present inventors significantly improve the processability by adding a phenolic antioxidant together with the aromatic low-polymerization degree polyester, particularly a phenolic antioxidant having a molecular weight of 500 or more to the heat-resistant ABS resin. In addition, it has been found that the stability against thermal oxidation deterioration can be remarkably improved.

That is, the present invention has a softening point relative to 100 parts by weight of an ABS resin modified with maleimide or α-methylstyrene.
It is in the range of 60 to 250 ° C and has a number average molecular weight of 500 to 10
0.01-20 parts by weight of a terephthalic acid-based low-polymerization degree polyester represented by the following general formula (I) and a molecular weight in the range of 000
An object of the present invention is to provide a heat-resistant ABS resin composition containing 0.01 to 5 parts by weight of a phenolic antioxidant of 500 or more.

(Wherein, R ₁ is an alkyl group having 1 to 18 carbon atoms or R ₃ −
CO-O-R ₂ - indicates, R ₂ represents an alkylene group having 2 to 8 carbon atoms, n represents shows 2-50. R ₃ has 1 to 18 carbon atoms
Represents an alkyl group, a phenyl group or an alkylphenyl group. Hereinafter, the present invention having the above gist will be described in more detail.

The heat-resistant ABS resin in the present invention includes a maleimide-modified ABS resin and an α-methylstyrene-modified ABS resin. Examples of the maleimide-modified ABS resin include, for example, an aromatic vinyl monomer, a copolymer of a vinyl cyanide monomer and a maleimide compound such as phenylmaleimide, cyclohexylmaleimide, or methylmaleimide, and the presence of a conjugated diolefin rubber. Below, a resin mixture with a graft copolymer obtained by copolymerizing an aromatic vinyl monomer and a vinyl cyan monomer, a resin mixture obtained by polymerizing a maleimide compound on the graft portion of the graft copolymer, A graft copolymer obtained by copolymerizing an aromatic vinyl monomer, a vinyl cyan monomer and a maleimide compound in the presence of an olefin rubber, and the like.Examples of the α-methylstyrene-modified ABS resin include, for example, ABS obtained by graft polymerization of styrene and acrylonitrile on diene polymer
Resin and α-methylstyrene / acrylonitrile copolymer, α-methylstyrene / acrylonitrile / styrene copolymer, α-methylstyrene / acrylonitrile ・ 2,
5 After grafting styrene and acrylonitrile on a resin mixture of dichlorostyrene copolymer or α-methylstyrene / acrylonitrile / methyl methacrylate copolymer, and diene rubber latex, copolymer obtained by grafting α-methylstyrene and acrylonitrile Polymer, a resin mixture of butadiene / acrylonitrile / styrene copolymer and a resin mixture of α-methylstyrene / acrylonitrile copolymer and the like in which a part of styrene is replaced with α-methylstyrene in an NBR / AS mixture, These are common in that they have a high heat distortion temperature and have a drawback of poor processability (fluidity during processing).

Also, these heat-resistant ABS resin, for example, polycarbonate resin, saturated polyester resin, polyamide resin,
When used in combination with engineering resins such as polyphenylene ether resin and polyacetal resin, one of the drawbacks of these engineering resins is that the notched impact strength is low.

In the terephthalic acid-based low-polymerization degree polyester represented by the general formula (I) used in the present invention, the alkyl group having 1 to 18 carbon atoms represented by R ₁ and R ₃ includes methyl, ethyl, propyl , Butyl, hexyl, octyl,
2-ethylhexyl, nonyl, isononyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and the like, and examples of the alkylene group having 2 to 8 carbon atoms represented by R ₂ include ethylene, 1,2-propylene, 3-propylene, 1,2-butylene, 1,3-butylene, 1,4-butylene, 2,2-dimethyl-1,3-propylene, 3-methyl-1,
Examples thereof include 5-pentylene, 1,6-hexylene, and 1,8-octylene, and examples of the alkylphenyl group represented by R ₃ include tolyl, xylyl, butylphenyl, and tert-butylphenyl.

In the general formula (I), R ₂ represents a group derived from an aliphatic glycol. As the glycol, a mixture of two or more different glycols may be used.

The terephthalic acid-based low-polymerization degree polyester represented by the general formula (I) is, for example, a reactive terephthalic acid derivative such as terephthalic acid or dimethyl terephthalate;
It can be readily prepared by reacting a glycol represented by HO-R ₂ -OH. When the terminal group of the terephthalic acid-based low-polymerization degree polyester thus produced is a hydroxyl group or a carboxyl group, the terminal hydroxyl group is acylated or the terminal carboxyl group is esterified to be blocked. Is done.

Further, the terephthalic acid-based low-polymerization degree polyester represented by the above general formula (I) needs to have a softening point in the range of 60 to 250 ° C, more preferably 100 to 200 ° C, and the softening point is lower than this. In the case of (1), the heat deformation temperature of the resin tends to be lowered, and in the case of more than 3, the insoluble matter may remain during processing. The number average molecular weight is 50
It is appropriately selected from the range of 0 to 10,000, more preferably 1,000 to 5,000. The average molecular weight is determined by the degree of polymerization and the type of raw materials used, but can be arbitrarily determined by adjusting the molar ratio of each component of the raw materials used and the method of condensation.

Hereinafter, specific examples of the terephthalic acid-based low-polymerization degree polyester used in the present invention will be shown.

No.1: Condensate of ethylene glycol / 1,4-butanediol (molar ratio 1: 1) and dimethyl terephthalate (molecular weight of about 300
0, softening point 160-170 ℃) No.2: Condensate of 1,4-butanediol and dimethyl terephthalate (Molecular weight about 1500, softening point 205-215 ° C) No. 3: Condensate of 2,2-dimethyl-1,3-propanediol and dimethyl terephthalate (molecular weight: about 6000, softening point: 70 to 90)
℃) The addition amount of the terephthalic acid-based low-polymerization degree polyester represented by the general formula (I) is 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the heat-resistant ABS resin. If it is less than this range, the desired effect cannot be expected, and if it exceeds this range, no further effect can be expected, and the properties of the heat-resistant ABS resin may be impaired.

Examples of the phenolic antioxidant used in the present invention include, for example, stearyl-β- (3,5-di-tert-butyl-
4-hydroxyphenyl) propionate, 1,6-hexamethylenebis [β- (3,5-ditert-butyl-4-hydroxyphenyl) propionate], 3-thia-1,5-
Pentanebis [β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,2-bis [4-
(2- (β- (3,5-ditert-butyl-4-hydroxyphenyl) propionyloxy) ethyl) phenyl] propane, 3,7-dioxa-1,8-octanebis [β- (3-
Tert-butyl-4-hydroxy-5-methylphenyl) propionate], 3,9-bis [1,1-dimethyl-2- (β
-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy) ethyl-2,4,8,10-tetraoxaspiro [5.5] undecane, pentaerythritol tetrakis [β- (3,5-di Tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (2,6
-Dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-ditert-butyl-4-hydroxybenzyl) isocyanurate, 2
-Octylthio-4,6-di (3,5-ditert-butyl-4-hydroxyphenoxy) -s-triazine, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert. Tributyl-5-methylbenzyl) phenyl] terephthalate, 1,1,3-tris (2-methyl-4-hydroxy-
5-tert-butylphenyl) butane, 1,3,5-tris (3,5
-Di-tert-butyl-4hydroxybenzyl) -2,4,6-trimethylbenzene, 1,2-ethanebis [3,3-bis (4-
Hydroxy-3-tert-butylphenyl) butyrate].

Among these phenolic antioxidants, the molecular weight
Compounds less than 500 tend to foam during molding,
It is preferable to use a compound having a molecular weight of 500 or more, particularly, esters of β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid with monohydric to tetrahydric alcohols and / or 1,3,5 -A tris (alkylated hydroxybenzyl) isocyanurate compound has a very large stabilizing effect on thermal oxidation and is preferred.

The addition amount of these phenolic antioxidants is heat-resistant ABS
The amount is 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the resin.

The processability of the composition of the present invention can be further improved by further adding a metal salt of Group II of the periodic table of higher fatty acids. Group II metal salts of the higher fatty acids include:
For example, calcium, magnesium, strontium, barium salts and zinc salts such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, 12-hydroxystearic acid, ricinoleic acid, behenic acid and montanic acid can be mentioned.

The composition of the present invention may be further added with an organic phosphite-based or organic phosphonite-based antioxidant to improve the oxidation stability. Examples of the organic phosphite-based or organic phosphonite-based antioxidant include trisnonylphenyl phosphite, tris (mono- and di-mixed nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tristearyl phosphite, octyl diphenyl phosphite, tetra (C _{12 to 15} alkyl) bisphenol A · diphosphite, tetra (tridecyl) 4,4'-butylidene bis (2-tert-butyl-5-methylphenol) diphosphite, Hexa (tridecyl) -1,1,3-tris (3-
Tert-butyl-4-hydroxy-6-methylphenyl) butane-triphosphite, distearyl pentaerythritol diphosphite, bis (2,4-ditert-butylphenyl) pentaerythritol diphosphite,
Bis (2,4,6-tritert-butylphenyl) pentaerythritol diphosphite, bis (2,6-ditertbutyl-4-methylphenyl) pentaerythritol diphosphite, 2,2'-methylenebis (4 , 6-ditert-butylphenyl) octyl phosphite and the like.

The composition of the present invention may be further added with a sulfur-based antioxidant to improve its oxidative stability. Examples of the sulfur-based antioxidants include dialkylthiodipropionates such as dilauryl, dimyristyl and distearyl esters of thiodipropionic acid and β-alkyl of polyols such as pentaerythritol tetra (β-dodecylmercaptopropionate). And mercaptopropionates.

The light resistance of the composition of the present invention can be further improved by adding a light stabilizer such as an ultraviolet absorber and a hindered amine compound.

As the light stabilizer, for example, 2-hydroxy-4-
2-hydroxybenzophenones such as methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis (2-hydroxy-4-methoxybenzophenone); 2- (2-hydroxy-5-methylphenyl) benzo Triazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole,
2- (2-hydroxy-3,5-di-tert-butylphenyl)
Benzotriazole, 2- (2-hydroxy-3,5-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzo Triazole, 2-
2- (2-hydroxy-3,5-dicumylphenyl) benzotriazole, 2,2'-methylenebis (4-tert-octyl-6-benzotriazolyl) phenol and the like
Hydroxyphenyl) benzotriazoles; phenyl salicylate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, etc. Substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-β, β-diphenyl acrylate, methyl-2- Cyanoacrylates such as cyano-3-methyl-3- (p-methoxyphenyl) acrylate; 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl- 4-
Piperidyl stearate, 2,2,6,6-tetramethyl-4
-Piperidyl benzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6
-Pentamethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) pentanetetracarboxylate, tetrakis (1,2,2,6,6-
Pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) di (tridecyl) -1,2,3, 4−
Butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2-butyl-2- (3,
5-ditert-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / dibromoethane polycondensate, 1,6-
Bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,6-bis (2,2, Hindered amine compounds such as 6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate.

In addition, if necessary, the composition of the present invention includes a heavy metal deactivator, a nucleating agent, a pigment, a filler, an organotin compound, a plasticizer, an epoxy compound, a foaming agent, an antistatic agent, a flame retardant, and the like. Can be done.

The method of adding each additive component of the present invention to the heat-resistant ABS resin is not particularly limited, and a generally used method can be applied as it is. For example, a method of dry blending an additive powder with a resin powder or a pellet, a method of spraying a solution or a melt of an additive on a resin powder or a pellet, a method of mixing a dispersion of an additive with a resin latex, and then salting out. A method or the like can be used.

〔Example〕

Next, the present invention will be specifically described with reference to examples. However, the invention is not limited by these examples.

Example 1 Styrene 22.5 in the presence of 70 parts by weight of polybutadiene rubber
Parts by weight and a graft polymer obtained by polymerizing 7.5 parts by weight of acrylonitrile and a copolymer of 50% by weight of α-methylstyrene, 35% by weight of methyl methacrylate and 15% by weight of acrylonitrile are mixed at a ratio of 25:75 (weight ratio). Thus, a heat-resistant ABS resin having an α-methylstyrene content of 37.5% by weight was obtained.

To 100 parts by weight of this heat-resistant ABS resin, stearyl-β- (3,
0.2 parts by weight of 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.25 parts by weight of tris (2,4-di-tert-butylphenyl) phosphite, 0.4 parts by weight of magnesium stearate and the sample compounds shown in Table 1 Add and mix well. From this mixture, a cylinder temperature of 260
Pellets were prepared using a twin-screw extruder at 25 ° C. and a rotation speed of 25 rpm, and the surface state was observed.

Using the obtained pellets, a melt indexer (MI, the same applies hereinafter; g / 10 minutes) under the conditions of a load of 2160 g and 265 ° C. and a spiral flow (260 ° C., 6 kg · f / cm ² ) using a melt indexer. cm). Further, the pellet, 260 ° C., injection molded under the conditions of 6kg · f / cm ^2, 1
Create a 27 x 12.7 x 6.4 mm square rod-shaped test piece, and use JIS K-68
The heat distortion temperature (° C.) was measured according to 71.

Furthermore, a test piece was injection-molded after being retained in an injection molding machine for 10 minutes, and a color difference (ΔE) from a non-retained test piece was prepared.
Was measured.

In each of the examples, the terephthalic acid-based low-polymerization degree polyester of the present invention was used as a sample compound, and in the comparative example, dioctyl terephthalate having a structure similar to that of ethylenebisstearic acid amide and terephthalic acid-based low-polymerization degree polyester was used. And molecular weight of about 5,000, softening point 100-1
A condensate of dimethyl isophthalate and 1,4-butanediol at 20 ° C. (comparative polyester) was used.

 Table 1 shows the results.

Example 2 Same α-methylstyrene-modified AB used in Example 1
100 parts by weight of S resin, 0.4 part by weight of magnesium stearate, 3 parts by weight of terephthalic acid-based low-polymerization polyester (No. 1), 0.2 part by weight of bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite and Example 1 was mixed with 0.2 part by weight of a phenolic antioxidant shown in Table-2.
Pellets were prepared in the same manner as described above.

The same test as in Example 1 was performed using the pellets.

 Table 2 shows the results.

Example 3 N-phenylmaleimide-modified ABS resin (heat deformation temperature 130
C) 100 parts by weight, 0.3 parts by weight of stearyl-β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.5 parts by weight of magnesium stearate and the sample compounds shown in Table 3 were mixed. Pellets were prepared using a twin screw extruder at 200 rpm and a cylinder temperature of 250 ° C.

Using these pellets, injection molding machine (cylinder temperature
A test piece having a thickness of 2 mm was prepared at 280 ° C. and 300 ° C. and a nozzle temperature of 300 ° C.), and silver streaks on the surface of the test piece were observed when the sample did not stay at 280 ° C. and after staying at 300 ° C. for 5 minutes.

The generation state of silver streaks is displayed in 10 levels, and indicates 1 (absent) and 10 (large). At the same time, the yellowness of the test piece was measured using a Hunter colorimeter, and the color difference (ΔE) after staying at 300 ° C. for 5 minutes with respect to the non-staying at 280 ° C. was measured.

 Table 3 shows the results.

[Effect of the Invention] When ethylene bisstearic acid amide and dioctyl terephthalate are used, not only greatly reduces the heat distortion temperature of the resin, which is the greatest feature of the heat-resistant ABS resin,
Deterioration of the surface state of the molded article, which is considered to be caused by thermal decomposition or volatilization, is also observed, and further, the hue is significantly deteriorated when left in a high-temperature molten state. When an aromatic polyester using isophthalic acid instead of terephthalic acid is used, not only MI and spiral flow are insufficient but also the hue is remarkably deteriorated.

On the other hand, when the terephthalic acid-based low-polymerization degree polyester of the present invention is used, not only MI and the spiral flow are good, but also the heat deformation temperature hardly decreases, and
It is clear that the hue does not deteriorate much even when left in a high-temperature molten state.

Also, from the results of Example 2, such an excellent effect of the present invention is attributable to the phenolic antioxidant, particularly, the molecular weight of 500
It is also clear that the above is remarkable when the phenolic antioxidants are used in combination.

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C08K 5: 115: 13) (56) References JP-A-61-264036 (JP, A) JP-A-2-24345 (JP, A) JP-A-62-45643 (JP, A) JP-A-62-181352 (JP, A) Kazuo Yugi, “Saturated Polyester Resin Handbook”, First Edition (1989-12-22), Nikkan Kogyo Shimbun p. 486 (58) Field surveyed (Int.Cl. ⁶ , DB name) C08L 55 / 02,67 / 02 C08K 5 / 11,5 / 13

Claims (1)

(57) [Claims] 1. A softening point of 60 to 250 to 100 parts by weight of an ABS resin modified with maleimide or α-methylstyrene.
C. and 0.01 to 20 parts by weight of a terephthalic acid-based low-polymerization degree polyester represented by the following general formula (I) having a number average molecular weight in a range of 500 to 10,000 and a phenolic antioxidant having a molecular weight of 500 or more. A heat-resistant ABS resin composition containing 0.01 to 5 parts by weight of an agent. (Wherein, R ₁ is an alkyl group having 1 to 18 carbon atoms or R ₃ −
CO-O-R ₂ - indicates, R ₂ represents an alkylene group having 2 to 8 carbon atoms, n represents shows 2-50. R ₃ has 1 to 18 carbon atoms
Represents an alkyl group, a phenyl group or an alkylphenyl group. )