JPS582313A - Production of heat-resistant and impact-resistant resin - Google Patents

Abstract

PURPOSE:In the presence of a diene rubber polymer, the bulk-suspension polymerization is carried out as a vinyl aromatic monomer, an unsaturated dicarboxylic anhydride and other vinyl monomers are added in a specific way to produce the titled resin by no use of an organic solvent. CONSTITUTION:When a monomer mixture composed of (A) 40-95wt% vinyl aromatic monomer such as styrene or alpha-methylstyrene, (B) 0.5-30wt% unsaturated dicarboxylic anhydride such as maleic anhydride and (C) 3-30wt% copolymerizable vinyl monomer such as acrylonitrile, methacrylonitrile or methyl methacrylate is subjected to graft polymerization in the presence of 1-25pts.wt. per 100pts. of the above monomer mixture, of a diene rubber polymer such as styrene-butadiene copolymer rubber, component A and/or component B dissolved in component (C) are added during the bulk polymerization at a slower rate than the consumption of components A and C to effect the complete polymerization of component B, then the suspension polymerization follows until the polymerization is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a heat-resistant and impact-resistant resin. Specifically, a vinyl aromatic monomer and an unsaturated dicarboxylic anhydride are prepared in the presence of a diene-based rubbery polymer.

The present invention also relates to a method for producing a resin having high heat resistance and impact resistance by copolymerizing a copolymerizable vinyl monomer by a bulk-suspension polymerization method.

More specifically, when copolymerizing a vinyl aromatic monomer, an unsaturated dicarboxylic acid anhydride, and a copolymerizable vinyl monomer in the presence of a diene-based rubbery polymer under bulk polymerization conditions, the vinyl aromatic monomer The unsaturated dicarboxylic anhydride dissolved in the monomer and/or the copolymerizable vinyl monomer is added continuously or intermittently during the completion of the bulk polymerization, and the unsaturated dicarboxylic anhydride is substantially added during the bulk polymerization. The present invention relates to a method for producing a copolymer having high heat resistance and impact resistance, which is characterized by completely polymerizing the polymer and then continuing the polymerization under suspension polymerization conditions to substantially complete the polymerization.

Copolymers consisting of styrene and maleic anhydride are well known and have been applied in many fields. As is well known, a feature of the above copolymer is that styrene and maleic anhydride tend to form alternating copolymers in a radical copolymerization reaction, and this alternating copolymer is converted into styrene monomer. Insoluble. Furthermore, maleic anhydride has the property of being easily hydrolyzed during polymerization in the presence of water, such as suspension polymerization or emulsion polymerization. Therefore, many efforts have been made and various methods have been proposed in order to avoid these problems and produce the desired copolymer when producing a styrene-maleic anhydride copolymer. Also, styrene
Although maleic anhydride copolymers are known to have excellent heat resistance, attempts have been made to produce copolymers by adding rubbery polymers to further improve impact resistance. However, the presence of the rubber component increases the viscosity of the reaction system, and in the styrene-acrylonitrile-maleic anhydride copolymerization reaction system, in addition to the above-mentioned copolymerization reaction characteristics, it also increases the possibility of crosslinking reaction. I have to consider it. As a method for producing the styrene-maleic anhydride copolymer containing the rubber component, a solution polymerization method is often employed in the presence of a solvent. However, since these polymerization methods use organic solvents, large-scale recovery equipment is required, which is disadvantageous as an industrial production method. Avoiding the formation of alternating copolymers by allowing a copolymerizable vinyl monomer to coexist in the polymerization stage of the first bulk polymerization process in a suspension polymerization method, and dissolving the produced copolymer into unreacted monomers. In order to improve the properties of the copolymer and to homogenize the composition of the resulting copolymer, a mixture consisting of an unsaturated dicarboxylic anhydride, a vinyl aromatic monomer, and a copolymerizable vinyl monomer was added in portions. The present invention was completed by substantially completely polymerizing the unsaturated dicarboxylic acid anhydride at the end of the polymerization. Furthermore, by incorporating a copolymerizable vinyl monomer into a graft copolymer consisting of a vinyl aromatic monomer, an unsaturated dicarboxylic acid anhydride, and a rubbery polymer, the heat distortion temperature and impact strength of the resulting resin are improved. was found to improve.

That is, in the bulk polymerization stage, an unsaturated dicarboxylic acid anhydride is added and copolymerized together with a vinyl aromatic monomer and/or a copolymerizable vinyl monomer under certain conditions, thereby forming a copolymer. By controlling the state in which unsaturated cicarusic acid anhydride is incorporated into the polymer, and in the process in which the rubbery polymer, which is the continuous phase at the start of polymerization, undergoes phase inversion as the polymerization progresses, the above-mentioned specific addition effect is grafted. It affects the reactivity and structure of the rubbery polymer dispersed phase formed, and the interaction with the continuously formed copolymer under bulk polymerization conditions and also with the continuously formed copolymer during the suspension polymerization process. Unexpected heat resistance.

The present invention was completed by discovering that a resin with excellent impact resistance and moldability can be obtained.

That is, the present invention contains 40 to 95% by weight of vinyl aromatic monomer,
A monomer mixture of 0.5 to 30% by weight of an unsaturated dicarboxylic anhydride and 3 to 30% by weight of a copolymerizable vinyl monomer,
When performing graft polymerization in the presence of 1 to 25 parts by weight of the diene rubbery polymer based on 100 parts by weight of the monomer mixture, dissolved in the vinyl aromatic monomer and/or copolymerizable vinyl monomer. The unsaturated dicarboxylic anhydride is added continuously or intermittently during the termination of the bulk polymerization at a rate slower than the consumption rate of the vinyl aromatic monomer and the copolymerizable vinyl monomer, and A method for producing a heat-resistant and impact-resistant resin, which is characterized by substantially completely polymerizing a saturated dicarboxylic acid anhydride, and then continuing the polymerization under suspension polymerization conditions to substantially complete the polymerization. In carrying out the invention, continuous or intermittent addition of the unsaturated dicarboxylic acid anhydride is essential, but a portion may be added initially at the start of bulk polymerization.

The initial addition amount can be 0 to 40% by weight of the monomer charged. If it exceeds 40% by weight, a heterogeneous copolymer with a high anhydride concentration will be produced, which is not preferable.

The amount of vinyl aromatic monomer and/or copolymerizable vinyl monomer used for dissolution may be at least the amount capable of dissolving the unsaturated dicarboxylic anhydride, but the amount of Appropriate.

Including unsaturated dicarboxylic anhydride added at the rate of consumption of vinyl aromatic monomer and copolymerizable vinyl monomer,
It refers to the rate expressed as the sum of the consumption of vinyl aromatic monomer and copolymerizable vinyl monomer during polymerization to form a copolymer. More specifically, unsaturated dicarboxylic acid anhydrides, vinyl aromatic monomers, and/or copolymerizable vinyl monomers are added continuously or intermittently, including mixed monomers added initially. The amount of vinyl aromatic monomer and copolymerizable vinyl monomer consumed per unit time when the copolymerization reaction and grafting reaction to the diene rubbery polymer proceed to form the graft copolymer. refers to the total amount of In the presence of a diene rubbery polymer such as polybutadiene, an unsaturated dicarboxylic anhydride is added to a polymerization system containing a vinyl aromatic monomer and a copolymerizable vinyl monomer as main components. When copolymerization is carried out by continuous dropwise addition at a rate slower than the consumption rate of the copolymerizable vinyl monomer, the content of unsaturated dicarboxylic anhydride in the graft copolymer is equal to the amount of unsaturated dicarboxylic anhydride added. Depends on speed. Furthermore, by coexisting a copolymerizable vinyl monomer, alternating copolymerization of the vinyl aromatic monomer and unsaturated dicarboxylic acid anhydride can be avoided, and the copolymerization of the produced copolymer to the unreacted monomer can be avoided. Improves solubility and enables homogeneous polymerization.

In the present invention, it is necessary to substantially completely bring the unsaturated dicarboxylic anhydride into one trough during bulk polymerization. At this time, if the amount of unsaturated dicarboxylic anhydride added is large, the polymerization rate of the bulk polymerization system will decrease. Therefore, the viscosity at the time of transfer to the suspension polymerization system in the latter stage also becomes high. In such cases, it is preferable to add a relatively low molecular weight plasticizer, stabilizer, etc. as a viscosity modifier, and also add vinyl aromatic monomer and/or copolymerizable vinyl even after the bulk polymerization is completed. It is also effective to add a monomer and measure the viscosity reduction.

Examples of the components constituting the heat-resistant and impact-resistant resin of the present invention are as follows. Examples of diene-based rubbery polymers include polybutadiene, polyisoprene, butadiene and/or isoprene and styrene, α-methylstyrene, (meth)acrylic acid, (meth)acrylonitrile, (
Substantially any rubbery conjugated diene polymer can be used, such as a copolymer with meth)acrylic acid ester, but any styrene-butadiene block copolymer is also suitable.

The amount used is 1 to 25% by weight, preferably 5 to 20% by weight, based on the total amount of monomers. Examples of vinyl aromatic monomers include styrene, α-methylstyrene, (o, p
-1 styrene, vinyl tolu=9-161 ene, and other styrenes, vinyl pyridine, and the like are used. The amount used is 40 to 95% by weight, preferably 50 to 85% by weight.0 As the copolymerizable vinyl monomer, vinyl cyan monomer,
Methacrylic acid ester monomers are particularly preferably used. As the vinyl cyanide monomer, for example, acrylonitrile, methacrylonitrile, chloroacrylonitrile, etc. can be used. As the methacrylic acid ester monomer, methyl methacrylate, ethyl methacrylate, and methacrylic dispersion alkyl ester can be used.The amount of the copolymerizable vinyl monomer used is 3 to 30% by weight, preferably 5 to 20% by weight. be. If the amount is too small, homogeneous polymerization, heat resistance, etc. will be inhibited, and if it is too large, the resin will be significantly colored, so it is preferable.

As the unsaturated dicarboxylic acid hydride, for example, anhydrous maleic acid, ita anhydride, conic acid, citraconic anhydride, 1oxymaleic anhydride, ethoxymaleic anhydride, etc. can be used. Usage amount, Ho, 5-30% by weight, preferably 2-2
Five-layered view, typed.

10- If it is too small, high heat resistance cannot be expected, and if it is too large, the viscosity will increase too much in the previous bulk polymerization stage, which is not preferable.

In the present invention, polymerization can proceed by thermal polymerization without necessarily using a polymerization initiator in bulk polymerization, but polymerization initiators such as organic peroxides and azobis compounds may be used. In order to substantially complete the polymerization, it is preferable to use the above polymerization initiator. It is also possible to use chain transfer and post-addition methods commonly used to adjust the molecular weight of polymers to improve moldability. The prepolymer obtained by bulk polymerization is added to a suspension system containing a suspension stabilizer under stirring and suspended. The suspension stabilizer used is not particularly limited, but may include polyvinyl alcohol, polyvinyl alcohol, So-called protective colloids such as hydroxyethyl cellulose and sodium polyacrylate, or inorganic substances that are poorly soluble in surface water such as calcium phosphate, are used in combination with various soaps, etc., if necessary. The amount of suspension stabilizer is determined based on the viscosity or polymerization rate of the prepolymer, but it is 0.1 to 5
．． The content is preferably 0% by weight, preferably 1 to 0.5 to 3.0% by weight. The amount of water used in the suspension polymerization process is 0.5 to 5 times the weight of all the monomers charged, but considering the removal of polymerization heat and production efficiency, it is preferably 1 to 3 times. The polymerization temperature in the invention is usually 60 to 100°C in the first stage bulk polymerization.
, preferably 70 to 90°C, and in the latter stage suspension polymerization, 60 to 140°C, preferably Vi 70 to 120°C gives good results. The polymerization conversion rate at the end of bulk polymerization varies depending on the amount of unsaturated dicarboxylic acid anhydride added and the amount of rubber, but at least it exceeds the phase conversion between the rubber phase and the resin phase, and the conversion rate is 6. It is preferably 10 to 40% by weight.

The present invention will be specifically explained using Examples, but the present invention is not limited to these.

Example 1 11 - Styrene 2000 in an autoclave equipped with a stirrer, a thermometer, a temperature regulator, a dropping funnel, a reflux condenser and a nitrogen gas inlet
F Acrylonitrile
500 dibenzoyl peroxide
5.5 dicumyl peroxide
2.5t-dodecyl mercaptan
14 was charged and sufficiently dissolved, the pressure was released, and the inside of the autoclave was replaced with nitrogen. -1 maleic anhydride 100
f acrylonitrile 2
After adjusting the mixed solution of 00 and charging it into the dropping funnel, the temperature inside the polymerization tank was kept at 72°C and while stirring,
The above maleic anhydride-acrylonitrile solution was added continuously from the dropping funnel at a rate of 150 f/hr over a period of 2 hours. After the addition was completed, bulk polymerization was continued for 1 hour. Bulk Polymerization 15-12- At the end of the reaction, the reaction solution was a viscous and homogeneous liquid, and the polymerization rate was 25% by weight. Further, maleic anhydride was contained in the produced polymer in an amount of 100% by weight of the amount added during bulk polymerization.

Next, 2700 ml of water was added to this polymerization system.
A prepared suspension consisting of the following was added under stirring to suspend the prevoy-q- produced in the bulk polymerization step. followed by 1
After suspension polymerization was carried out under stirring at a temperature of 20° C. for 3.5 hours, the polymer beads were separated from the slurry, washed with water, and dried. The obtained nonapolymer contains 5.5% maleic anhydride.
If it contains 5% by weight, its heat distortion temperature is 95℃,
The Izot impact strength was 5.1 wheels.

Example 2 Styrene was initially placed in the same autoclave as Example 1.
1500 f acrylonitrile 4
0Of maleic anhydride 5
0 styrene-casiene copolymer rubber (same as Example 1)
130 dibenzoyl peroxide
5.0 Dikun Ruber Oxide
2. After charging Ot-dodecylmercaptan 12 and sufficiently dissolving it, the inside of the autoclave was purged with nitrogen. Next, the temperature inside the polymerization tank was maintained at 72°C, and polymerization was started while stirring. Meanwhile, 250 ml of maleic anhydride was added separately.
f acrylonitrile 2
Adjust the mixed solution of 50% and charge it into the dropping funnel to start polymerization.
．． After 5 hours, it was continuously added at a rate of 20097 hours over 2.5 hours. After the addition was completed, bulk polymerization was continued for 1 hour. The reaction solution at the end of the bulk polymerization was a viscous and homogeneous liquid, and the polymerization rate was 47% by weight. Further, maleic anhydride was contained in the produced polymer in an amount of 99.6% by weight of the amount added during bulk polymerization. Next, this anti-15
After adding styrene 150F to the solution and sufficiently dissolving it, suspension polymerization was carried out in the same manner as in Example 1. The resulting polymer contained 12.5% by weight of maleic anhydride, had a heat distortion temperature of 110°C, and an Izot impact strength of 2.4 kg·on/cm 2 .

Example 3 In the same autoclave as Example 1, Suti V7 1500
f Methyl methacrylate
500 maleic anhydride
250 dibenzoyl peroxide (same as Example 1)
5.0 dicumyl peroxide
2. After charging Ot-togesylmercaptan 12 and sufficiently dissolving it, the inside of the autoclave was purged with nitrogen. Next, the temperature inside the polymerization tank was maintained at 72° C., and polymerization was started while stirring. On the other hand, separately 7v diacid anhydride 100
A mixed solution of 200v of 16-methyl methacrylate was prepared and charged into a dropping funnel, and added continuously at a rate of fi 150f/hour over 2 hours starting 0.5 hours after the start of polymerization. After the addition was completed, the bulk polymerization was continued for 1 hour.The reaction solution at the end of the bulk polymerization was a homogeneous viscous liquid, and the polymerization rate was 34% by weight.0Also, maleic anhydride was added to the produced polymer. 10 of the amount added during bulk polymerization.
It contained 0% by weight. Next, styrene 150f was added to this reaction solution and sufficiently dissolved, and then suspension polymerization was carried out in the same manner as in Example 1. The resulting polymer contained 5.5% by weight of maleic anhydride, had a heat distortion temperature of 102°C, and an Izot impact strength of 5.5-7.

Example 4 In Example 1, polybutadiene rubber (a chemical-free product, Jinxun N'!) was used instead of the styrene-butadiene copolymer rubber.
-35AS) was charged, and bulk-suspension polymerization was carried out using the same equipment and the same operating conditions as in Example 1. The reaction solution at the end of the bulk polymerization was a homogeneous viscous liquid, and the polymerization rate was 26.5% by weight. The nonapolymer thus produced contained 3.6% by weight of maleic anhydride, had a heat distortion temperature of 97 DEG C., and an Izod impact strength of 6.3 kf-an/cm.

Comparative Example 1 Styrene 650 was placed in a 2t glass flask equipped with a stirrer, thermometer, temperature controller, reflux condenser, and nitrogen gas inlet.
2 Acrylonitrile 2
30 anhydrous maleic ml
12G styrene-butadiene copolymer rubber (Example 1
) 100 dibenzoyl peroxide
2 dicumyl peroxide
After charging 0.8t-dodecylmercaptan 5 and sufficiently dissolving it, the inside of the flask was purged with nitrogen.

Then, bulk polymerization was started while stirring and maintaining the temperature inside the polymerization tank at 72°C.

Approximately 1 hour after the start of polymerization, the viscosity inside the υ system began to rise rapidly.
After 2 hours, a blocky polymer was produced in the reaction solution, so the polymerization reaction was stopped. Incidentally, when the reaction liquids were sampled at the first hour and the second hour and analyzed, it was found that maleic anhydride was contained in the polymer in an amount of 27% by weight and 24% by weight, respectively.

Comparative Example 2 A 2-ton device that was the same as the device used in Comparative Example 1 but further equipped with a dropping funnel.
Styrene in a glass flask 5
20r acrylonitrile
160 dilauryl peroxide (LPO)
3t-dodecrumel butane
3 was charged, and after dissolution, the inside of the flask was purged with nitrogen.

On the other hand, anhydrous malein@
25t styrene
A mixture of 95% and 95% was prepared and charged into a dropping funnel. Then, while maintaining the temperature inside the polymerization tank at 70 DEG C. and stirring, the above maleic anhydride-styrene solution was continuously added from the dropping funnel at a rate of 80 f/hr over 1 DEG 5 hours. After the addition was completed, bulk polymerization was continued for 1 hour. Next, Supertight 10 (13 chemical products) was added to this polymerization system.
70t Monogen LH (NOF product) 0.
1 water 70
The prepared suspension consisting of 0 was added and suspended under stirring. Subsequently, suspension polymerization was carried out at 70°C for 4 hours and at 80°C for 2 hours, and the same post-treatment as in the example was carried out. The heat distortion temperature of the obtained polymer was 85°C, and the Izot impact strength was 1.
．． It was 1st group, QJQn2.

In addition, the impact strength with isotto notch (thickness 7 inches) and heat distortion temperature are A8TM D-256 and D-, respectively.
648.

Applicant's agent Kaoru Furutani

Claims (1)

[Scope of Claims] 1. Monomers consisting of 40 to 95% by weight of vinyl aromatic monomer, 0.5 to 50% by weight of unsaturated dicarboxylic acid anhydride, and 3 to 50% by weight of copolymerizable vinyl monomer. The mixture is prepared by adding 1 to 10 parts by weight of the diene rubbery polymer to 100 parts by weight of the core monomer mixture.
During the graft polymerization in the presence of 25 parts by weight, the unsaturated dicarboxylic acid anhydride dissolved in the vinyl aromatic monomer and/or the copolymerizable vinyl monomer is added continuously or intermittently to the vinyl aromatic monomer and/or the copolymerizable vinyl monomer. and during the termination of the bulk polymerization at a rate slower than the consumption rate of the monomer and copolymerizable vinyl monomer, and substantially completely polymerizes the unsaturated dicarboxylic acid anhydride during the bulk polymerization, and then under suspension polymerization conditions. 1. A method for producing a heat-resistant and impact-resistant resin, which comprises continuing polymerization until the polymerization is substantially completed. 2. Claim 1 in which the copolymerizable vinyl monomer is a vinyl cyan monomer or a methacrylic acid ester monomer
The method described in section.