JPS59189149A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide the titled resin compsn. having excellent mechanical properties and moldability, by mixing an alkylstyrene/acrylonitrile copolymer with a graft copolymer obtd. by reacting specified vinyl monomers with a rubbery polymer in a specified ratio. CONSTITUTION:A graft copolymer obtd. by polymerizing 80-20pts.wt. monomer mixture consisting of 45-95wt% arom. vinyl monomer and/or alkyl methacrylate, 5-45wt% vinyl cyanide monomer and 0-20wt% other vinyl monomer in the presence of 20-80pts.wt. rubbery polymer such as polybutadiene rubber, is used. 50-95pts.wt. copolymer obtd. by suspension polymerizing 10-45wt% p- alkylstyrene of the formula (wherein R1, R2, R3 are each H, methyl), 10-45wt% acrylonitrile and 0-10wt% other monomer, is mixed with 50-5pts.wt. said graft polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized by heat resistance and impact strength represented by heat deformation temperature t.
This relates to a thermoplastic d1 fat composition that is well-balanced in mechanical properties, melt flowability, moldability, and productivity.

Diene rubber? Graft copolymers obtained by combining vinyl monomers such as styrene, acrylonitrile, and methyl methacrylate in the presence of rubber-like polymers are widely used as so-called ABS resins and MABSfi resins. Since then, much research has been conducted on improving the manufacturing method and quality of omelette. In improving the quality of these graft copolymers, improving heat resistance has become a particularly important issue, and a typical method for achieving this is to replace part or all of the styrene with α-methylstyrene. The specific method of substitution is as follows: (1) A method of graft polymerizing a diene-based rubbery polymer, α-methylstyrene, and methyl methacrylate under suspension conditions (Japanese Patent Publication No. 57
-697, Japanese Patent Publication No. 39-20511) and (2) diene-based rubbery polymer e, a graft copolymer obtained by graft polymerizing styrene and acrylonitrile, and acrylonitrile and a predominant amount of a-methylstyrene. Method of mixing copolymers obtained by emulsion polymerization (Tokukosho, 55
-18194), etc. have been proposed. However, in method (1), the graft polymerization takes an extremely long time due to the difficulty of polymerization of α-methylstyrene, and in method (2), emulsion polymerization is essential, so the polymer recovery step is difficult. There is a problem in that it is complicated and it is difficult to avoid the contamination of impurities. In addition, in the case of α-methyl styrene-based resins, as the α-methylstyrene content is increased and the heat distortion temperature is raised, the bath melt fluidity deteriorates significantly. The problem is that it is difficult. That is, the method of improving heat resistance using α-methylstyrene has problems in productivity and moldability, and is not yet satisfactory.

On the other hand, para-tert-butylstyrene (hereinafter referred to as p-7-butylstyrene) and dimethylstyrene (p-7-butylstyrene)
-Methylstyrene) Natoko's representative Salelhaler alkylstyrene has good polymerizability and the resulting polymer has a high heat distortion temperature, so heat-resistant resins using these para-alkylstyrene polymers have been proposed. (U.S. Pat. No. 2,725.261 and ACS P
olymer PreprjntS.

Volume 26, No. 2, Page 96, published September 1982)
The resins of T et al. have the disadvantage of low strength,
Not very practical. Therefore, in the presence of 2 to 283 ijt% of a diene rubber-like polymer, e
A resin has been proposed in which 60 to 80% by weight of an aromatic vinyl compound and 12 to 30% by weight of acrylonidolyl are polymerized, the essential components of which are tert, -alkyl resin (U.S. Patent No. 3. 426,103 specification)
However, in this method, it is essential to carry out the grafting in the presence of a rubbery polymer, and in order to develop impact properties, strict regulation of the polymerization conditions is required, which reduces productivity. It has the disadvantage of being inferior. Also, t-butylstyrene,
In the presence of 10 to 70 parts by weight of a rubbery polymer, a monomer mixture of 90 to 25 parts by weight of t-butylstyrene, acrylonitrile, and methyl methacrylate.
A resin composition in which a graft copolymer obtained by polymerizing part by weight is mixed has also been proposed (Japanese Patent Publication No. 5.5-4780). l/ Due to the fact that it is contained as all essential components, there are disadvantages such as not only insufficient heat distortion temperature but also poor melt flowability.

Therefore, the inventors of the present invention aimed to develop a thermoplastic resin composition with a well-balanced thermal deformation temperature, impact stress, melt flowability, and productivity.As a result of intensive studies, we found that para-alkyl styrene and acrylonitrile are highly balanced. By mixing in a specific ratio a copolymer obtained by turbid polymerization and a graft copolymer obtained by graft polymerizing a specific vinyl monomer (mixture) to a rubbery polymer, the above purpose can be achieved efficiently. We have discovered that this goal can be achieved and have achieved this goal with the present invention.

That is, the present invention provides (A) para-alkyl Jv: 7-tyrene 5 represented by the general formula % (in the formula, R, , R2 and R3 represent hydrogen or a methyl group).
Monomer mixture consisting of 5-901 [Horuchi, Aryllonitrile 10-4511] and other vinyl monomers copolymerizable with these monomers 0-10% by weight 50 to 95 overlapping parts of a copolymer obtained by suspension polymerization and (B) (a) Rubber-like polymer 2
In the presence of 80 parts by weight? (b) Aromatic vinyl monomer and/or ester alkyl ester monomer 45 to 95 weight percent anionized vinyl monomer 5
Monomer mixture 8 consisting of ~45 parts by weight and 0 to 20 parts by weight of other vinyl light years copolymerizable with these monomers.
Graft copolymer obtained by polymerizing 0 to 20 parts by weight
5 parts by weight of the thermoplastic resin composition is provided.

α-methylstyrene/acrylic I7 nitrile copolymer, α
- In α-methylstyrene copolymers 3 such as methylstyrene/styrene/acrylonitrile copolymers,
Increasing the α-methylstyrene content significantly deteriorates melt fluidity, making it difficult to achieve a good balance between heat distortion temperature and melt fluidity. A copolymer consisting of alkyl styrene and acrylonitrile exhibits good melt fluidity despite having a high heat distortion temperature.In addition, in general, in the production of vinyl polymers, suspension polymerization method is different from emulsion polymerization method. Compared to this, productivity is superior in that the polymer can be easily recovered, but suspension polymerization has a problem in that the polymerization rate is extremely slow due to the difficulty of polymerization of d-methylstyrene-based copolymer α-methylnutyrene. In contrast, copolymerization of para-alkylstyrene and acrylonitrile is easier (the copolymerization rate is increased, and the productivity is improved). The polymer has an excellent affinity with the above-mentioned graft copolymer, and it is difficult to mix the two.
As a result, a thermoplastic resin composition with excellent thermal deformation/temperature, impact strength, and melt fluidity can be obtained.

The copolymer (A) of the present invention is 55 to 90% by weight of barium alkylstyrene, specifically 65 to 85% by weight,
Weight rylonitrile 10-45 weight, Tokushiko 15-3
5% by weight, 0 to 1% by weight of other vinyl monomers copolymerizable with these monomers, and < r = o to 5% by weight.
It is obtained by polymerization using water as a medium.

The para-alkyl styrene used in the copolymer (A) is a para-alkyl compound represented by the general formula % (3 (wherein, R, R2 and R3 represent hydrogen or a methyl group)). It is a styrene derivative.Specifically, p-methylstyrene, p-
-ethylstyrene, p-improhylstyrene, p-t
p-methylstyrene and p-t-butyfurestyrene are preferably used. A small proportion of these copolymerizable vinyl monomers may be copolymerized.There is no limit to the percentage of these copolymerizable vinyl monomers, but specific examples include styrene, a -Methylstyrene e is a representative example of aromatic vinyl monomers, methacrylate (IJ/l' methyl acid, acrylic acid, acrylic acid, acrylic acid) and vf (meth).
Acrylic acid monomers and the like can be used. Also,
A small amount of an isomer substituted at the ortho or meta position of para-alkylstyrene may be included as long as the effects of the present invention are not impaired.

In the copolymer of the present invention (/I), if the copolymerized amount of para-alkyl styrene is less than 55%, the heat deformation temperature of the resin composition will be insufficient, and the If this occurs, sufficient impact strength cannot be obtained, which is undesirable.

Furthermore, if the copolymerized amount of acrylonitrile is less than 10% by weight, the resistance to cracking will be insufficient, and if it exceeds 45% by weight, the thermal stability of the resin composition will be poor, resulting in discoloration during molding or poor melt flowability. This is not preferable because it lowers the temperature. If the copolymerization amount of other vinyl spinning wheel rods exceeds 10 flat strips, the heat distortion temperature and melt fluidity will be low, which will impair the effects of the present invention, which is not preferable.

Suspension polymerization is essential for the polymerization method of copolymer (A).

In bath liquid polymerization, the recovery of the solvent is complicated, and in emulsion polymerization, the recovery operation of the polymer is complicated, impurities such as emulsifiers tend to remain in the polymer, and a high heat distortion temperature cannot be achieved. The method of suspension polymerization of copolymer (A) is not particularly limited and can be carried out by any commonly known method. For example, azo-based initiators such as azobinisobutyanide and azobiscyclohexane) and radicals such as per-benzobenzo(X)V and per-L'+2-4i-based initiators such as lauroyl peroquinide. Polymerization is carried out by using a generation initiator and using water as a medium in the presence of an inorganic or organic suspending agent under intense pressure.

The monomer mixture may be charged in its entirety at the initial stage of polymerization, or a part of the monomer may be charged in advance and the remaining amount may be added continuously or intermittently afterwards. It is also possible to employ a so-called bulk-suspension polymerization method in which the initial stage of the polymerization is started with bulk polymerization of a monomer mixture, and midway through the polymerization, transition is made to suspension polymerization to complete the polymerization.

What is the graft copolymer (B) used in the present invention? (a) In the presence of 20 to 80 parts by weight of a rubbery polymer and 60 to 70 parts by weight of (1)) Aromatic vinyl monomer body and/or
or methano IJ) L/acid alkyl ester light year body 45-95 weight, Tokueko 55-90 weight, weighted vinyl light year body 5-45 weight, Tokue 10-35
A monomer mixture containing 0 to 20% by weight, especially 0 to 10 parts by weight of N and other vinyl monomers copolymerizable with these monomers, particularly 80 to 2 parts by weight, especially ? 70~60
The rubber-like polymers include diene rubbers such as polygetadiene rubber (P'BD), polyurethane rubber/styrene copolymer rubber (SBR), and polyacrylic. Acrylic rubber such as butyl chloride, ethylene-propylene-nonconjugated diene rubber (EPDM)
) etc. are used. In addition to styrene, three aromatic vinyl monomers include p-methylstyrene, p-t-, and f-f.
Nuclear 4 such as Ivy, tyrene, argyl styrene, d
-Methylstyrene etc. are used. Examples of alkyl methacrylates that can be used include methanoIJ/methyl phosphate, ethyl methacrylate, and the like. Acrylonitrile and methacrylonitrile are used as vinyl cyanide monomers. There are no particular restrictions on the vinyl monomers that can be copolymerized with these monomers, but
For example, acrylic/L7, methyl acrylate, maleic anhydride, maleimide, N-phenylmaleimide, etc. can be used.

If the proportion of the rubbery polymer (a) used in the graft copolymer (B) is less than 20 parts by weight or more than 80 parts by weight, it is not preferable because high impact strength cannot be obtained. Monomer mixture (b) which is a graft component, where aromatic vinyl monomer and/or methano') ld
l When the proportion of alkyl ester monomer is less than 45% by weight or more than 95% by weight, or the proportion of vinyl cyanide monomer exceeds 45% by weight or 5% by weight
If it is less than that, the resin composition obtained will be inferior in impact strength, heat distortion temperature, and/or thermal stability, which is not preferable. Furthermore, if the proportion of other vinyl monomers exceeds 20 parts by weight, impact strength, heat distortion temperature, melt fluidity, etc. will be poor, and the effects of the present invention will be impaired, which is not preferable.

The method for producing the graft copolymer (B) is not particularly limited; polymerization can be carried out by commonly known methods such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, emulsion-suspension polymerization, and bulk polymerization.
Suspension polymerization etc. are used. Polymerization initiator ekomo#! ff
Although there is no particular limitation, organic or inorganic peroxide-based radical generation initiators are usually used. Any method can be used to charge the monomer mixture into the polymerization system, and the initial total amount? It is also not possible to use a method of charging the monomers all at once, a method of adding them continuously during polymerization, or a method of controlling the composition of the resulting graft copolymer by changing the composition of the monomer mixture during the polymerization. It is also possible to use a chain transfer agent in combination, if necessary.

In the thermoplastic resin composition e of the present invention, a copolymer (A
) and the graft copolymer (B) at a mixing ratio of the copolymer (
Graft copolymer (B) is added to 50 to 95 parts by weight of A).
) is 50 to 5jXn=parts. Mixing ratios other than this are not preferred because it is difficult to obtain a resin composition with well-balanced heat distortion temperature, impact strength, and melt fluidity.

In the production of the thermoplastic resin composition of the present invention, there are no particular restrictions on the method of mixing the copolymer (A) and the graft copolymer (B), but they are usually melted using an extruder or kneader. mixed.

The thermoplastic resin composition of the present invention may further include other polymers such as styrene-acrylonitrile copolymer, styrene-methyl methacrylate-acrylonitrile copolymer,
Styrene-d-methylstyrene-acrylonitrile copolymer, α-methy)V-styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene-
N-phenylmaleimide copolymer, α-methylnuthylene-acryloni) IJ-N-phenylmaleimide copolymer, polyamide, polyethylene terephthalate, polyethylene terephthalate, polycarbonate, etc. can be mixed with other thermoplastic resins to achieve desired performance characteristics. This can be adjusted. Further, during or after kneading, various stabilizers, lubricants, additives, flame retardants, colorants, glass and metal fibers, reinforcing agents, fillers, etc. can be mixed.

Hereinafter, the present invention will be explained in more detail using Reference Examples, Examples, and Comparative Examples. In addition, in the following, parts and ratios represent parts by weight and i% by weight, respectively. The heat distortion temperature was measured according to ASTM D-648-56, and the Izot impact strength was measured according to ASTM D-256-56A method. The melt viscosity was measured at a resin temperature of 240° C. using a Koka type flow tester. The final polymerization rate was determined by collecting a portion of the copolymer beads or latex after completion of polymerization, and quantifying unreacted monomer using gas chromatography.

Reference Example 1 Production of Copolymer (A) Copolymers A-1 to A-9, A-12 and A-16 Table 13 100 parts of a monomer mixture having the composition shown above was mixed with 200 parts of pure water, 0.2 parts of acrylamide-methyl methacrylate copolymer (suspending agent) and 0.5 parts of sodium phosphate
The mixture was poured into an aqueous solution consisting of 50% of water at high speed (pressing W) to strain the suspension, and the temperature was gradually raised from 70°C to 90"C over 240 minutes, then 105°C over 10 minutes. After that, the suspension polymerization was completed by holding at that temperature for 60 minutes.After the polymerization was completed, it was cooled, washed with water, filtered, and dried to obtain granular copolymers A-1 to A-9, A-12, and A-1
I got 6.

The monomer mixture is usually charged all at once at the beginning, but in A-1, the initial t: p-t-butylrenuti V
30 parts of acrylonitrile, 30 parts of acrylonitrile and test-
Add 0.1 part of dodenlumel butane, 60 minutes, 7
5th minute, 90th minute, 105th minute t = p - t - petit l
10 parts of Restylane was added to each.

In A-6f, the initial amount is 30 parts of acrylonitrile,
After charging 25 parts of p-methylstyrene and 0.1 part of tert,-dodecylmerkaketane, 15 parts each of p-methylstyrene were charged at the 60th, 80th, and 100th minutes.

Copolymer A-10: Polymerization Fi t = 180 parts of pure water, 5.0 parts of potassium oleate.
0 part glucose 0.5 part, sodium pyrophosphate 0.5 part and ferrous sulfate 0.005 part were charged, and after nitrogen substitution, the temperature was 70°C.
I heated it up and fired it. Then, an aqueous solution prepared by dissolving 0.5 parts of cumene hydroperoxide and 2.0 parts of potassium oleate in 20 parts of empty pure water was added at a constant rate over 12 hours to one of the feed ports. In parallel with this, a monomer mixture consisting of 60 parts of η-methylstyrene, 25 parts of acrylonitrile, 5 parts of styrene, and tert,-dodecylmercaptan was charged at a constant rate for 8 hours from a separate charging port, and then acrylonitrile A monomer mixture consisting of 5 parts of Jv and 5 parts of styrene was charged at constant speed over 8 hours, and then a monomer mixture consisting of 25 parts of acrylonitrile and 5 parts of styrene was charged at constant speed over 1 hour. ! The i1 total reaction conditions were such that the temperature was maintained at 70°C for 10 hours from the start of polymerization, and then the temperature was raised to 90°C and maintained for 2 hours.

The obtained copolymer latex was coagulated using magnesium sulfate, washed with water, filtered and dried to produce copolymer A-10 in the form of a white powder.

Copolymer A-11: tert. - Dodecyl mercaptan preparation o.
Copolymer A-11 was produced in the same manner as Copolymer A-10 except that the s part was changed.

After the polymerization of each copolymer was completed, a portion of each polymer or latex was sampled and the amount of unreacted monomer was determined by gas chromatography to determine the final polymerization rate. The measurement results are shown in Table 1.

Reference Example 2 (Production of Graft Copolymers) Using the rubbery polymer and monomer mixture shown in Table 2, graft copolymers B-1 to B-8 were produced in the following manner.

Copolymers B-1 to B-5: Nitrogen-substituted polymerization tank e, 120 parts of pure water, glucose, 0.5 part of sodium pyrophosphate, ferrous sulfate [], 5 parts of OG, and the specified amounts shown in Table 2. of Polybutadiene Deluxe was added and thoroughly stirred. Next, while controlling the temperature inside the tank to 60°C, the monomer mixture shown in Table 2 was charged at a constant rate from one charging port over a period of 5 hours. At the same time, add 60 parts of pure water and sodium laurate (emulsifier) from another port.
2.5 parts and cumene hydrope! A water bath consisting of 0.2 parts of Leokind was carried out over 6 hours at a constant speed for 7 nights. After the addition is complete, raise the temperature to 75°C. Polymerization was carried out for one hour. After the polymerization is completed, it is coagulated with magnesium arsenate, washed, dehydrated, and dried to obtain powdery graft copolymers B-1 to B-5, respectively.
was manufactured.

Copolymers B-6 and B-7 = 300 parts of nitrogen-substituted polymerized f4e pure water, 0.6 part of acrylamide-methyl methacrylate copolymer (suspending agent) and 0.7 part of sodium phosphate, Stir thoroughly to dissolve. Next, a predetermined amount of ethylene-propylene-nonconjugated diene copolymer rubber (Mitsui EpT4070 manufactured by Mitsui Petrochemical Industries tLle) shown in Table 2Q and a monomer mixture were mixed with 0.5 parts of benzoyl peroxide and 100 parts of toluene. e
The dissolved solution was poured into a suspension at high speed and then strained to form a suspension (1e), followed by polymerization at 80'C for 10 hours and then at 100C for 2 hours. After the polymerization was completed, toluene and unreacted monomers were removed by steam distillation, followed by washing with water, filtration, and drying to produce granular graft copolymers B-6 and B-7.

Copolymer B-8 A polymerization tank purged with nitrogen was prepared using ethylene-propylene-nonconjugated diene copolymer rubber (Mitsui EpT
407.0 ) and the monomer mixture to benzoyl peroxide 0
．． 5 parts and 120 parts of benzene, n-power 1 fufu 12
0 parts of the mixture was added, thoroughly dissolved, and polymerized at 80°C for 5 hours and at 100°C for 1 hour. After the polymerization was completed, the hot medium and unreacted monomers were removed by steam distillation to produce graft copolymer B-8.

Table 2 *1) PBD Polybutadiene latex (parts are solid content equivalent) EPDM Ethyl V-propylene-non-conjugated diene copolymer rubber (Mitsui Petrochemicals, Rumor, Mitsui EpT4070) $2) S T Styrene PTB Sp-t -Guchi IV Styrene FMS p-Methylstyrene Examples and Comparative Examples Copolymers A-1 to A-13 produced in Reference Example 1 and graft copolymers B-1 to B-8 produced in Reference Example 2 are shown below. 31
The stabilizer and 1,''()'J phenyl phosphite 0.! t
After adding 0.3 part of (butylphenol)provimenate, the mixture was melt-kneaded in an extruder and pelletized.

Next, each pellet was injection molded to form each test piece, and the physical properties were measured. The measurement results are shown in Table 3f.

(Blank below) As is clear from the results in Table 3, the resin composition of the present invention [material (C
-1-C-15) Thermal distortion temperature 1f, mj, impact strength and melt fluidity are all excellent.

On the other hand, resin compositions (C-16, C-
17) has a low heat distortion temperature. Furthermore, monomer mixtures containing α-methylstyrene have a slow polymerization rate in suspension polymerization;
Since the polymerization rate does not increase (A-9 in Table 1), it is necessary to perform emulsion polymerization. However, resin compositions ('C-'18, C-19) made using α-methylstyrene-based copolymers (A-10, A-11) obtained by emulsion polymerization have a high heat distortion temperature. , poor in either melt fluidity or impact strength. Furthermore, copolymers (A
) obtained using compositions (C-20, C-21, C-
No. 22) has a low heat distortion temperature or poor melt flowability, and cannot obtain a palanne with good physical properties.

Moreover, when the blending ratio of copolymer (A) and graft copolymer (B) is outside the scope of the present invention (C-26, C-24
) is inferior in any or all of heat distortion temperature, impact strength, and melt fluidity, making it impossible to obtain a preferred resin composition.

That is, the thermoplastic resin composition of the present invention has a well-balanced heat resistance as represented by heat distortion temperature, mechanical properties as represented by impact strength, and moldability as represented by melt flowability. Since it has good productivity, it is expected that it will be applied to various fields in the future by taking advantage of these characteristics.

Patent applicant: Toshi Co., Ltd. −3(

Claims (1)

[Scope of Claims] (A) Variable alkyl styrene 55-9 represented by the general formula (wherein R, , R2 and R3 represent hydrogen or a methyl group)
0% by weight, 10-45% by weight of acrylonitrile and other vinyl monomers copolymerizable with these monomers O-1
(1) in the presence of 50 to 95 parts by weight of a copolymer obtained by suspension polymerization of a monomer body temperature metal material consisting of 0% by weight and 20 to 80 parts by weight of (B) (a) rubbery polymer. Aromatic vinyl monomer and/or Mekkuri I/Il? , A/I
-/Kill Esthe I type monomer 45 to 95% by weight, vinyl cyanide single piece 5 to 45% by weight, and other vinyl monomers copolymerizable with these monomers 0 to 20% by weight A thermoplastic resin composition prepared by mixing 50 to 5 parts by weight of a graft copolymer obtained by polymerizing 80 to 20 parts by weight of a monomer mixture consisting of: