JPS59179611A - Rubber-modified styrene/acrylonitrile copolymer resin composition - Google Patents

Abstract

PURPOSE:The titled copolymer resin composition improved in gloss and impact resistance, comprising a specified composition obtained by copolymerizing a styrene monomer with an acrylonitrile monomer in the presence of a rubbery polymer. CONSTITUTION:A rubbery modified styrene/acrylonitrile copolymer resin composition obtained by copolymerizing 65-92pts.wt. styrene monomer with 8- 35pts.wt. acrylonitrile monomer in the presence of 1-20pts.wt. rubbery polymer by a continuous bulk or solution polymerization process or a bulk-suspension two-stage polymerization process, wherein (i) the mixed solution index is determined in a toluene/methyl ethyl ketone (7/3) solvent is 6-14, (ii) the average particle diameter of the rubbery polymer particles in the composition is 0.5- 1.5mu, (iii) the relation-ship of inequalities I holds when the rubber-modified styrene/acrylonitrile copolymer resin is dissolved in a methyl ethyl ketone/methanol (7/3) solvent, and (iv) the solution viscosity of the rubbery polymer is 20-50cSt.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a styrene-acrylonitrile copolymer resin composition whose impact properties are improved by a rubbery polymer.

More specifically, in the presence of a rubbery polymer, a monomer of styrene and a chemical compound of Akuinu Rironi+-IJ are copolymerized by a continuous bulk polymerization method, a solution polymerization method, or a bulk suspension method (G13 method). The present invention relates to a resin composition with improved shine and impact properties.

Conventionally, three-way copolymer resins consisting of rubber-like polymers and styrene/acrylonitrile polymers have been widely used as base materials for various mechanical parts and electrical products as resins with excellent impact strength and mechanical strength. . Such terpolymer resins have conventionally been mainly produced by emulsion polymerization. On the other hand, the continuous bulk or solution polymerization method or the bulk-suspension polymerization method has production advantages such as lower cost, simpler steps, and easier wastewater treatment than the emulsion polymerization method. -On the other hand, there were problems with the quality of the product as an industrial product, such as the resin's low light intensity and insufficient impact resistance.

The present inventors have conducted extensive studies in view of the importance of such problems, and have found that using a specific rubbery polymer, having a specific rubbery polymer particle size and a specific mixed solution index, and further using a specific monomer. It was discovered that the gloss and impact resistance were significantly improved in the composition described above, and the performance balance was comparable to that of emulsion polymerization.
We have arrived at the present invention.

That is, in the present invention, in the presence of 1 to 20 parts by weight of a rubbery polymer,
A rubber-modified soubrene obtained by copolymerizing 65 to 92 parts by weight of a styrene monomer and 8 to 65 parts by weight of an acrylonitrile monomer by a continuous bulk or solution polymerization method or a two-stage bulk-suspension polymerization method. - In the acrylonitrile copolymer resin composition, (1) the mixing ratio of toluene and methyl ethyl ketone is 7/
(2) the average particle diameter of the rubbery polymer particles in the composition is 0.
．． (6) when the rubber-modified styrene/acrylonitrile copolymer resin is dissolved in a 7/filtration mixed solution of methyl ethyl ketone and methanol, the acrylonitrile in the polymer portion that is soluble in the mixed solution) IJ series monomer weight composition (WSA
) and the styrenic monomer weight composition (Wss), and the styrene monomer weight composition (Wss), and the acrylonitrile of the polymer part other than the rubber-like polymer that is undesirable and mellow in the mixed solution.
) and styrenic monomer weight (WDS) is expressed by the following formula (
1) and (1) 1.2) Xs/
XD) 0.9 (4) The layer liquid viscosity of the rubbery polymer is 2
This is a rubber-modified styrene/acrylonitrile based co-11 resin composition characterized by having a molecular weight of 0 to 50 centistokes.

As the continuous bulk or solution polymerization method and the bulk-suspension two-stage polymerization method in the present invention, known methods or combinations thereof are used and are not particularly limited. ! L polymerization method is preferably used. Regarding the bulk polymerization method, for example, a rubbery polymer is dissolved in one monomer, and the rubbery polymer is dissolved in a single column bath solution with or without addition of a molecular weight regulator, a polymerization initiator, etc. is continuously fed into a stirred reactor and prepolymerized in one or more stirred reactors until 10-60% of the monomer is converted to polymer, while at the same time converting the rubbery polymer. Convert to the form of dispersed particles. Next, main polymerization is further continued in one or more reactors, and after converting 50 to 99% of the total amount of monomers subjected to polymerization into a polymer, this polymerization liquid is transferred to a devolatilization tank. A part of the oligomer is removed to remove the unreacted monomer odor, and a granular resin composition is obtained through a granulation process. In addition, in the example of continuous solution polymerization, in one or more of the rubber dissolving step and the reaction step described in ``2'', -C, ethylbenzene, toluene,
A solvent such as methyl ethyl ketone is supplied and most of it is recovered together with the monomer in the devolatilization step. In both bulk and solution polymerization methods, molecular weight regulators, polymerization initiators, etc. are supplied at arbitrary locations, but the monomers are supplied at an addition rate of 0 to 50%. It is preferable that

In addition, the monomers are added in increasing amounts at any step to continue the polymerization.

In addition, to give an example of the bulk-suspension two-stage polymerization method, a rubber-like polymer is dissolved in a styrene monomer, and an acrylonitrile monomer, in some cases a molecular weight regulator, and a polymerizable After adding an initiator etc., prepolymerization is performed in the first stage of bulk polymerization under stirring until 10 to 40 monomers are converted into polymer, and the rubbery polymer is converted into dispersed particles. . Separately, prepare an aqueous phase to which a suspension stabilizer has been added, add the above bulk polymerization solution to form a suspension, and then continue main polymerization to achieve a conversion rate of 60 to 100% into a single liquid polymer. .

Thereafter, depending on the safety, after the polymerization is completed, a devolatilization operation or a heat treatment is performed to adjust the residual volatile content of the resin or the degree of crosslinking of the rubbery polymer. Further, granular resin is obtained through dehydration, drying, and granulation steps by conventional methods. At any point in this process, in monomer compositions of the invention, the mixing solution index ranges from 6 to 14 times, preferably from 65 to 16 times, more preferably from 65 to 11 times. The object of the present invention cannot be achieved even if this value is less than 6 or exceeds 14. The mixing and G liquid indexes in the present invention are:
Approximately 10 grams of the sample was poured into 30 i + g of a mixture of toluene and methyl ethyl ketone at a ratio of 7/6, and then centrifuged, and the soluble components in the mixture were removed by the decanting method, and the insoluble components swollen in the mixture were immediately removed. The weight (ws) of the component is measured, and then the vaginal component is dried under vacuum [Ton].The weight (Wd) of the insoluble component obtained by drying is measured, and ws/wd
The mixed solution index, which is expressed as 8 times the value of , is the amount of rubbery polymer during polymerization, the amount of molecular weight regulator, the amount of solvent,
It is adjusted by adjusting the amount and type of polymerization initiator, residence time in the post-polymerization devolatilization step and granulation step, treatment temperature, etc., and those skilled in the art can adjust it to a predetermined value by trial and error method. be able to. It is not clear why the gloss and impact resistance performance of compositions within the range of the mixed solution index referred to in the present invention improves, but since the resin performance changes extremely sharply with respect to the mixed bath index, such an index It is considered to be an index that reflects the properties of rubber-like polymer particles in rubber-modified styrene/acrylonitrile copolymer resin compositions obtained by copolymerization by continuous bulk or solution polymerization methods or bulk-suspension two-stage polymerization methods. It will be done.

In the measurement of the mixed solution index referred to in the present invention, when toluene is used instead of the mixed liquid referred to in the present invention, no suggestion regarding performance improvement can be obtained.

In the present invention, the average particle diameter of the rubbery polymer particles is 0.4
It is in the range of 5 to 1.511μ, preferably 06 to 1μ, more preferably 06 to 11μ. Even if this value is less than 0.6μ, or exceeds 1.5μ, the effects of the present invention cannot be obtained. In the present invention, the average particle diameter of the rubbery polymer particles is measured as follows.

That is, the particle diameter of 50 to 2.00 rubber-like polymer particles was measured in an electron micrograph taken using a thin section method and averaged according to the following equation.

Average particle diameter - Σ1D2/Σ7. ．． D (However, n is the number of rubbery polymer particles with a particle size.) The average particle size of the rubbery polymer is determined by the conditions of the prepolymerization step in the resin manufacturing process, for example, the rubbery polymer particles in the prepolymerization step. It can be adjusted by adjusting the amount of polymer used, the amount of monomer used, the amount of molecular weight regulator, the amount and type of polymerization initiator, the conversion rate of monomer to polymer, the polymerization temperature, the polymerization rate, etc. Those skilled in the art can adjust the average particle diameter to a desired value by a trial and error method.

In the present invention, when the rubber-modified styrene/acrylonitrile copolymer resin composition is dissolved in a 7/6 mixed solution of methyl ethyl ketone and methanol, the acrylonitrile monomer weight of the polymer portion that is soluble in the mixed bath solution composition(
WSA ) and styrenic monomer weight composition (Wss ),
and insoluble acrylonitrile in the polymer portion other than the rubbery polymer) IJ-based monomer weight composition (~■T)A)
The relationship between styrenic monomer weight composition (Wl)S ) satisfies the following formula (1), preferably the following formula <n>.

(1) t2 > Xs/XD λ0.9
(101, (15ΣXs/x+)) 0.95WSA-IVj)A, WDS, etc. in the above equation are measured as follows.

That is, approximately 1 g of the resin was left in a 7/3 mixed solution of methyl ethyl ketone and methanol at 30 m, e to achieve partial dissolution, and then centrifuged to remove the polymer portion that was soluble in the mixed solution. and the insoluble polymer portion are separated by decanting. Next, the solvent is removed from both sections by vacuum drying, and the weight composition of the acrylonitrile monomer constituting the polymer of each section is determined based on the elemental analysis value of N element of the dried product.

Further, the weight composition of the styrene monomer constituting the polymer of each part can be determined, for example, by balancing the weight values of the raw material, the produced polymer, and the soluble part and insoluble part of the mixture. The XS/XDO value is the concentration ratio (a) of styrene monomer and acrylonitrile monomer in the polymerization mixture.
, and the concentration ratio (b) of styrene monomer and acrylonitrile monomer in the conversion range of 40 to 99%, i.e. (a) / (b), the polymerization temperature in both conversion ranges. , the amount of solvent and the operation of the devolatilization step, etc., and those skilled in the art can obtain the desired value by trial and error method. In addition, the conversion rate of monomer to polymer is 50 to 90.
%, preferably 50-80%, more preferably 55-7
Preferably, a method is used in which a side line is placed in a range of zero and a devolatilization operation is performed.

The rubbery polymer referred to in the present invention may be any polymer that exhibits rubbery properties at room temperature, such as polybutadienes, styrene-butadiene copolymers, styrene-butadiene block copolymers, and ethylene-propylene. One or more types of copolymers such as ethylene-propylene 00 pre-L/N copolymers, butadiene-acrylonitrile copolymers, acrylic acid ether copolymers, silicone rubbers, etc. are used.

Among these rubber-like polymers, there are 100% polyester.

The solution viscosity of the rubbery polymer used in the present invention is particularly preferred.

20-50 cst, preferably 30-50 cstσ
) range. Therefore, even if it is less than 20 cst, it is still 5[
Even if it exceeds 1C, ST, the performance of impact resistance and gloss is not good. In such a rubber-like polymer, the micro (4) structure is not particularly limited, but when the total butadiene component constituting the comb-like polymer is taken as 100 parts, 1,4
20 to 40 parts of synu-linked frigiene component, again 91 parts
2 parts or less are preferably used, and 25 parts or less of the 1,2 vinyl-bonded bookdiene component is more preferably used.

The rubber-modified styrene-acrylonitrile copolymer resin composition of the present invention is not particularly limited, and preferably contains 2 to 25% by weight of a rubbery polymer. It is contained in a range of 4 to 18% by weight.

The styrenic monomers used in the production of the rubber-modified styrene-acrylonitrile copolymer resin composition of the present invention include 0, for example, styrene, α-methylstyrene, o, m,
Vinyl-substituted or nuclear-substituted alkylstyrenes such as p, methylstyrene, ethylstyrenes, isopropylstyrenes, and phthylstyrenes, α, o, m, and vinyl-substituted or nuclear-substituted alkylstyrenes such as p-bromostyrene and chlorostyrenes]・More than one species such as rhodanized styrenes and halogenated alkylstyrenes are used. Among these, styrene and paramethylstyrene are preferably used.

Further, as the acrylonitrile monomer, for example, one or more of acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, etc. can be used, and acrylonitrile and methacrylonitrile are preferably used.

The composition of the styrene monomer and acrylonitrile monomer in the polymer' portion is as follows:
Usually 65 to 92 parts by weight of styrenic monomer, preferably 7
A range of 0 to so 1 illi parts is used. Furthermore, one or more of methyl methacrylate, maleic anhydride, and the like may be added as a constituent of the polymer in an amount not exceeding 20 parts by weight.

Organic peracids may be used in preparing the compositions of the invention. As such an organic peroxide, a known organic peroxide can be used. Among them, the 10-hour half-life temperature is 50
-140°0 is preferable, 60-130°C
Those in the following are more preferably used. In addition, in the production of the composition of the present invention, known molecular weight regulators used in the production of styrenic polymers are similarly used, such as t-dodecylmercaptan, n-dodecylmercaptan, alpha-methylstyrene dimer, etc. Preferably used.

The rubber-modified styrene-acrylonitrile copolymer resin composition obtained in the present invention can be used alone, but it can also be used in combination with other resins, such as polycarbonate, styrene-acrylonitrile copolymer resin, and styrene-maleic anhydride. It may be used in combination with a copolymer resin or the like. Also,
It is preferable to use one or more of stabilizers against heat, light, and oxygen, flame tightening agents, plasticizers, colorants, lubricants, antistatic agents, etc., added to the composition of the present invention.

The composition of the present invention comprises rubber-modified styrene obtained by continuous bulk or solution polymerization or bulk-suspension two-stage polymerization.
This acrylonitrile-based copolymer resin composition has extremely high gloss and impact resistance, a result that could not be expected from conventional technology, and has extremely high industrial utility value. The invention will be further explained by examples.

Example 1a, Production method 75 parts by weight of styrene, 25 parts by weight of acrylonitrile, rubbery polymer (manufactured by Ube Industries, Ltd., trade name: Ubepol 13)
HB-bath liquid viscosity (41 cst) 7 parts by weight, t-dodecyl mercaptan 0.2 parts by weight, organic peroxide (t-
Butylperoxy 2-ethylhexanony)) 0.05
A raw material solution consisting of parts by weight was prepared. Polymerization was carried out in a stirrer reactor until the conversion of monomers to polymer reached 22%. Then, 0.05 parts by weight of 1-butylperoxy 2-ethylhexanoate was added, and 2 parts by weight of acrylonitrile, 200 parts by weight of water, and suspension stabilizer 02 Jushuto were added to the mixture, and suspension polymerization was carried out with stirring. When the conversion rate of monomer to polymer reached 72%, the polymerization was terminated and the remaining extenders were removed by steam distillation. A rubber-modified styrene/acrylonitrile-modified resin was then obtained through an extrusion process.

b5 Analysis and Performance Evaluation The results of the analysis and performance evaluation of the obtained rubber-modified styrene/acrylonitrile modified resin are shown in Table 1. Performance evaluation was performed using the following method.

Impact resistance: Evaluated by measuring falling weight impact strength.

Heavy metal objects are dropped at increasing heights,
The height at which cracks occur in the test piece was determined, and the impact resistance was expressed as the product of the height and the weight of the heavy object.

Gloss: Measured according to JIS K-8741.

Fluidity: In injection molding, evaluation was made based on the oil pressure of the molding machine (short shot oil pressure) required for the lowest injection pressure that does not cause short shots. In Table 1, the differences are listed in square values based on the reference example.

(If it is negative, the oil pressure is lower than the reference example, and it is evaluated as a material with good fluidity during molding.) Heat resistance: AS
The Vicat softening point was measured according to TM-D1525.

Example 2 75.5 parts by weight of styrene, 245 parts of acrylonitrile, 5 parts by weight of ethylbenzene, 7 state metropolitan areas (
Manufactured by Ube Industries, Ltd., Part name: Ube Ball 1ROUB, Fj Liquid viscosity: 41 cst) Organic peroxide (1,1-bis(t)
A raw material solution consisting of 5 parts by weight of -butylperoxy), 3.5-)limethylcyclohexane), and 2 parts by weight of (-dodecylmercaptan) was polymerized in a 6-stage stirred polymerization tank reactor. The raw material solution was continuously supplied from the first stage tank.The stirring number of the first stage tank was 200 rpm.The polymerization solution was supplied from the sixth stage tank at 2
A series of stages each led to a devolatilization tank consisting of a preheater and a vacuum chamber. The amount of monomer at the inlet of the first stage devolatilization tank was 35 parts by weight, and the total amount of monomer converted to polymer was 65 parts by weight. The remaining amount of monomer at the outlet of the first stage devolatilization tank is 10 parts by weight, and the monomer is passed through a flow area with an average residence time of 45 minutes at a temperature of 90 to 1400C, and then transferred to the second devolatilization tank. The remaining monomers and solvent were removed substantially completely to obtain a polymer at 275°C, which was then subjected to a granulation process to form rubber-modified styrene.
Acrylonitrile) IJ-based copolymerized 1-fat silk composition was obtained.

The analytical evaluation results are shown in Table 1.

Example 5 and Comparative Example 12 Experiments were conducted with I- in the same manner as in Example 2, except that the rotation speed of the first stage stirring tank was changed. A rubber-modified styrene/acrylonitrile copolymer resin composition was obtained.

The analysis and evaluation results are shown in Table 1.

Reference Example Table 1 shows the evaluation results of a commercially available rubber-modified styrene/acrylonitrile copolymer resin composition obtained by emulsion polymerization.

Comparative Example 3 Same as Example 2 except that the amount of acrylonitrile supplied to the first stage stirring tank was 12 parts by weight, and 125 parts by weight of acrylonitrile was supplied to the second stage stirring tank. I experimented with it.

The results are shown in Table 1.

Comparative Example 4 Same as Example 2 except that the amount of styrene supplied to the first stage stirring tank was 60 parts by weight, and 155 parts by weight of styrene was supplied to the second stage stirring tank. experimented on. The results are shown in Table 1.

Example 56 and Comparative Example 56.7 In Example 2, the remaining amount of monomer at the outlet of the first stage devolatilization tank and the distribution area to the second stage devolatilization tank The experiment was carried out in the same manner as in Example 2, except that the temperature and the operating temperature of the second stage devolatilization tank were sequentially changed.The results are shown in Table 1.

Example 7 In Example 1, as the rubbery polymer, Asahi Kasei Co., Ltd.
Product name Asaprene 700A (solution viscosity 45 cst
), and the experiment was conducted in the same manner as in Example 2, except that the rotation speed of the first stage stirring tank was changed.

The results are shown in Table 1.

Comparative Example 8 In Example 2, Diene 65 (trade name, manufactured by Asahi Kasei Co., Ltd.) (solution viscosity 89 cst) was used as the rubbery polymer.
The experiment was carried out in the same manner as in Example 2, except that the rotation speed of the first stage stirring tank was changed. The results are shown in Table 1.

2882 Iijima-cho, Totsuka-ku, Yokohama 0 shots Akira Hisashi Aihara Hadano type Bodhi 332 0 shots by Haruo Inoue 4-10-8 Kuki, Zushi City

Claims (1)

[Scope of Claims] (1) In the presence of 1 to 20 parts by weight of a rubbery polymer, 65 to 92 parts by weight of a styrenic monomer is produced by a continuous bulk or solution polymerization method or a two-stage bulk-suspension polymerization method. In a rubber-modified styrene/acrylonitrile copolymer resin composition obtained by copolymerizing 8 to 65 parts by weight of an acrylonitrile monomer, 1) the mixing ratio of toluene and methyl ethyl ketone is 715;
The mixed solution index in a mixed solvent is 6 to 14 times, and 2) the average particle diameter of the rubbery polymer particles in the composition is 0.5
6) When the rubber-modified styrene/acrylonitrile copolymer resin is dissolved in a 7/6 mixed solution of methyl ethyl ketone and methanol, the acrylonitrile monomer in the polymer portion that is soluble in the mixed F3M is Weight composition (WSA), styrenic monomer weight composition (WSS), and acrylonitrile monomer polymerization composition (1'l'DA) of the polymer portion insoluble in the mixed solution and other than the rubbery polymer. ) and styrene monomer weight composition (WDS) is expressed by the following formula (1)
and (1) 1.2Σ Xs/ xl) ) o, q
4) A rubber-modified styrene/acrylonitrile copolymer resin composition, wherein the rubbery polymer has a solution viscosity of 20 to 50 centistokes. (2) The composition according to claim 1, which is obtained by continuous bulk or solution polymerization. (5) The following formula (
11) The composition according to claim 1, which satisfies 11). (it) 1.051 X8/XD l O,95
(4) The composition according to claim 1 or 3, wherein the continuous block ←←4 is obtained by using a multi-stage stirred tank array reactor in a solution polymerization method.