JP4386645B2 - Aromatic vinyl resin and method for producing the same - Google Patents

Description

【００３５】
【表２】

【００３６】
【発明の効果】
本発明は、芳香族ビニル系単量体と不飽和カルボン酸無水物の組成比、有機過酸化物種類および単量体の消費反応速度に対して有機過酸化物の添加速度を制御することで、高分子量、高透明性、かつ、耐熱性、色相に優れた芳香族ビニル系樹脂を製造することができる。[0001]
[Technical field to which the invention belongs]
The present invention relates to an aromatic vinyl resin excellent in high molecular weight, high transparency, heat resistance, and hue, and a method for producing the same.
The aromatic vinyl-based resin of the present invention can be preferably applied to the fields of automobile parts, electric / electronic parts, household appliance parts, miscellaneous goods and the like.
[0002]
[Prior art]
Conventionally, resins obtained by copolymerizing aromatic vinyl monomers such as styrene and α-methylstyrene and unsaturated carboxylic acid anhydrides such as maleic acid and itaconic acid have good transparency and impart heat resistance. Since it is effective, it is used as a heat-resistance imparting material that improves the heat resistance of AS-based resins, MS resins, and the like (see, for example, Patent Document 1 or 2). However, in the process of polymerizing these, there is a problem that the hue deteriorates due to the influence of oligomers and the like generated at that time depending on the polymerization temperature and the initiator type.
[0003]
[Patent Document 1]
JP 59-18747.
[Patent Document 2]
Japanese Patent Laid-Open No. 62-169842.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to solve these conventional drawbacks and to provide a copolymer excellent in high molecular weight, high transparency and heat resistance, and hue even when a recovered organic solvent is used, and a method for producing the same. .
[0005]
[Means for Solving the Problems]
As a means for solving such problems, as a result of intensive studies, an organic peroxide having a half-life temperature of 90 ° C. to 110 ° C. with respect to an aromatic vinyl monomer and an unsaturated carboxylic acid anhydride is obtained. The inventors have found that an aromatic vinyl resin excellent in high molecular weight, high transparency, heat resistance, and hue can be obtained by polymerization while adding at a specific rate, and have led to the present invention.
[0006]
That is, the present invention is 60 to 95 parts by weight aromatic vinyl monomer and (a), with respect to monomer 100 parts by weight of an unsaturated carboxylic acid anhydride (b) containing 40 to 5 parts by weight, 1 to a method for solution polymerization using 100 parts by weight of ketones and with respect to the monomer 100 parts by weight, peroxyester organic peroxide 10-hour half-life temperature of 90 ° C. to 110 ° C. ( c) a from 0.008 to 0.50 parts by weight, were added at an addition rate of 0.001 to 0.018 parts by weight / hour with respect to the reaction rate 6-10 parts by weight / hour of the monomer, the polymerizing at least 70 parts by weight of the monomer, wherein then continuously introduced into a vented devolatilizing extruder at a cylinder temperature of 200 to 250 ° C., and removing the volatiles in the following vacuum 40kPaA shall be the weight average molecular weight of from 180,000 to 400,000 2 mm thickness measured in accordance with ASTM D-1003 is 88% or higher, Vicat softening temperature is 110 ° C. or higher, and thickness is 2 mm measured in accordance with JIS K-7105. This is a method for producing an aromatic vinyl resin in which the hue (YI) of the part is 4.0 or less .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
Examples of the aromatic vinyl monomer (a) used in the present invention include monomers such as styrene, α-methylstyrene, dimethylstyrene, vinyltoluene, p-methylstyrene, t-butylstyrene, chlorostyrene, and the like. Derivatives are mentioned, and among these, styrene is particularly preferable.
[0008]
Examples of the unsaturated dicarboxylic acid anhydride monomer (b) include unsaturated dicarboxylic acid anhydride monomers such as maleic acid, itaconic acid, citraconic acid, and anicotic acid. Among these, maleic anhydride is particularly preferable. Things are preferred.
[0009]
In the aromatic vinyl resin of the present invention, a monomer copolymerizable with the aromatic vinyl monomer (a) and the unsaturated dicarboxylic acid anhydride monomer (b) is impaired. Copolymerization can be carried out to the extent not present.
As those monomers, vinyl cyanide monomers such as acrylonitrile, methacrylonitrile, fumaronitrile, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylate-2-ethylhexyl, phenyl methacrylate, Methacrylic acid ester monomers such as benzyl methacrylate and isobornyl methacrylate, and acrylic acid ester monomers such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and cyclohexyl acrylate A polymer can be mentioned.
[0010]
In the aromatic vinyl resin of the present invention, the aromatic vinyl monomer (a) is 60 to 95 parts by mass, and the unsaturated dicarboxylic acid anhydride monomer (b) is 5 to 40 parts by mass. Preferably, the aromatic vinyl monomer (a) is 70 to 85 parts by mass, and the unsaturated dicarboxylic anhydride monomer (b) is 15 to 30 parts by mass. Resin. When the content of the aromatic vinyl monomer (a) is less than 60 parts by mass and the amount of the unsaturated dicarboxylic acid anhydride monomer (b) exceeds 40 parts by mass, the heat resistance represented by the Vicat softening temperature is good. However, the total light transmittance is less than 88% and the transparency is lowered. When the content of the aromatic vinyl monomer (a) exceeds 95 parts by mass and the unsaturated dicarboxylic acid anhydride monomer (b) is less than 5 parts by mass, the heat resistance typified by the Vicat softening temperature is high. It becomes less than 110 degreeC.
[0011]
In the present invention, known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization and the like can be applied. Among these, solution polymerization is preferable.
[0012]
The organic peroxide (c) used in the present invention can be water-soluble or oil-soluble, but oil-soluble is particularly preferable. Examples of the organic peroxide (c) include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis ( Peroxyketals such as 4,4-di-t-butylperoxycyclohexyl) propane, 2,2-bis (t-butylperoxy) butane, n-butyl 4,4-bis (t-butylperoxy) valerate, t -Butyl peroxyisopropyl monocarbonate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-butyl peroxybenzoate, t-butyl peroxacetate, etc. Organic peroxides such as peroxyesters can be mentioned. Le systems are preferred.
[0013]
When an organic peroxide having a 10-hour half-life temperature of less than 90 ° C. is used, for example, the polymerization is low temperature and the polymerization is required for a long time, the productivity is significantly reduced and the oligomer is easily generated, so that the hue is deteriorated. . Moreover, since the produced | generated oligomer remains in the collection | recovery organic solvent, it becomes the cause which worsens the hue of resin obtained by superposing | polymerizing after the next time. When an organic peroxide having a 10-hour half-life temperature exceeding 110 ° C. is used, the polymerization does not proceed unless the polymerization temperature is raised, so that a homopolymer of an aromatic vinyl monomer is formed and the transparency is remarkably deteriorated. Further, among organic peroxides having a 10-hour half-life temperature of 90 ° C. to 110 ° C., use of a peroxy ester type is particularly preferable.
[0014]
The organic peroxide (c) used in the polymerization is 0.008 to 0.50 parts by mass, preferably 0.01 to 0.25 parts by mass. When the organic peroxide (c) is less than 0.008 parts by mass with respect to 100 parts by mass of the monomer, the polymerization is remarkably slow, and when it is more than 0.50 parts by mass, the polymer having a weight average molecular weight of 180,000 or more. Cannot be obtained. The organic peroxide (c) can be added all at once at the start of polymerization within a range that does not impair the object of the present invention, and the remainder can be added at a specific addition rate according to the present invention.
[0015]
The consumption reaction rate of the monomer of the present invention is the rate obtained by determining the polymer production amount (part by mass) in the monomer addition time as a ratio in 100 parts by mass of the monomer and dividing by the elapsed time at that time. Point.
[0016]
The addition rate of the organic peroxide (c) used in the polymerization should be 0.001 to 0.018 parts by mass / hour with respect to the consumption reaction rate of 6 to 10 parts by mass / hour of the monomer. is required. The addition rate is preferably 0.001 to 0.016 parts by mass / hour. When the addition rate is less than 0.001 part by mass / hour, a homopolymer of an aromatic vinyl monomer is formed, and the transparency and hue are significantly deteriorated. When the addition rate exceeds 0.018 parts by mass / hour, the weight average molecular weight is less than 180,000, and a high-molecular weight polymer having a good color cannot be obtained.
[0017]
In the polymerization while adding the organic peroxide (c), the monomer used in the present invention, the aromatic vinyl monomer (a) and the unsaturated dicarboxylic acid anhydride monomer (b) are both Alternatively, an appropriate amount or the entire amount of one can be charged at a time in the initial stage of polymerization and the remainder can be added. Here, the whole amount of the aromatic vinyl monomer (a) and optionally an appropriate amount of the unsaturated dicarboxylic acid anhydride (b) are charged all at once in the initial stage of polymerization to obtain the unsaturated dicarboxylic acid anhydride monomer (b). The method of adding the remaining amount is most preferable.
[0018]
The resin recovery method used in the present invention is a method of continuously introducing into a vented devolatilizing extruder after polymerization and obtaining the resin while recovering volatile components. The devolatilizing extruder with a vent mentioned here is an extrusion having a feed port for supplying a mixture of volatile matter after polymerization and a resin (hereinafter referred to as a resin liquid) and one or more exhaust vents in front thereof. Say about the machine. The screw of the devolatilizing extruder may be uniaxial or biaxial, but biaxial is preferred because it is a heat-resistant resin and requires kneading ability. The condition of the devolatilizing extruder is preferably such that the temperature of the resin liquid to be fed is higher than the boiling point of the organic solvent being used. The volatile matter can be easily recovered by rapidly reducing the pressure to a pressure lower than the equilibrium vapor pressure at the temperature of the organic solvent to be used. Also, for example, before feeding to the devolatilizing extruder, the organic solvent to be used is continuously fed into a can maintained at a pressure lower than the equilibrium vapor pressure at the temperature, and the volatile content is removed in advance by a continuous extraction method. It is also possible to recover some of the resin concentration and increase the resin concentration.
[0019]
Cylinder temperature is 200-250 degreeC, Preferably it is 210-240 degreeC. If the temperature exceeds 250 ° C., the resulting resin undergoes a thermal history and the residual maleic anhydride is affected, resulting in a poor hue. If the temperature is less than 200 ° C., the resin is difficult to melt, and a large amount of residual volatile matter remains in the resin, which deteriorates transparency and hue. The degree of vacuum needs to be 40 kPaA (A is an absolute pressure standard) or less, and preferably 20 kPaA or less. If it exceeds 40 kPaA, a large amount of residual volatile matter remains in the resin, and the transparency and hue deteriorate. As a measure of the volatile content to be recovered, it is preferable to adjust the residual volatile content in the obtained resin to 1% or less. Further, it is preferably 6000 ppm or less.
The organic solvent used in the present invention can be used after purifying the volatile matter recovered by a devolatilizing extruder by a known method such as a method by distillation or a method by liquid-liquid separation. The recovered organic solvent can be used by mixing all or part of it with a new one. The purity of the recovered organic solvent is preferably 97% or more, more preferably 98% or more. When the purity of the recovered organic solvent is less than 97%, the transparency and hue of the resin obtained by polymerization are deteriorated and the desired resin cannot be obtained.
[0021]
As the organic solvent used in the present invention, ethers such as tetrahydrofuran, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, dimethylformamide, cyclohexane and the like can be used. Of these, ketones are preferable. In other organic solvents, it is necessary to increase the cylinder temperature and the degree of vacuum at the time of recovery by a devolatilizing extruder, and the hue of the obtained resin may deteriorate. [0022]
As for the organic solvent used for this invention, 1-100 mass parts is preferable with respect to 100 mass parts of monomers. More preferably, 5-67 mass parts is preferable with respect to 100 mass parts of monomers. When the amount of the organic solvent exceeds 100 parts by mass, the weight average molecular weight becomes less than 180,000, and the desired high molecular weight resin cannot be obtained.
[0023]
As for the molecular weight of the present invention, those having a weight average molecular weight of 180,000 to 400,000 are preferably produced.
[0024]
In the polymerization of the present invention, for example, mercaptans such as t-dodecyl mercaptan and n-dodecyl mercaptan, terpinolene, α-methylstyrene dimer, etc. can be used as the chain transfer agent or molecular weight modifier, and are known without any limitation. Can be used.
[0025]
The resin of the present invention can be used alone as a film or a molded product. Furthermore, it can be mixed with other known polymers. It exhibits excellent heat resistance and transparency in injection molding, blow molding, films and sheets.
[0026]
【Example】
The present invention will be specifically described by the following examples and comparative examples, but the present invention is not limited to the following examples.
[0027]
Each physical property in each example and comparative example was measured as follows.
(1) Weight average molecular weight The weight average molecular weight Mw of the aromatic vinyl-type resin obtained by this invention was measured on the following conditions using the size exclusion chromatography apparatus, and is a molecular weight of polystyrene conversion.
Apparatus: “SYSTEM-21” manufactured by Tosoh Corporation
Column; PLgel MIXED-B
Temperature: 40 ° C
Solvent; tetrahydrofuran detection; RI
Concentration: 0.2% by mass
Injection volume: 100 μl
Calibration curve: Standard polystyrene (manufactured by Polymer Laboratories) is used. (2) Total light transmittance Using a Toshiba Machine Co., Ltd. injection molding machine (IS-50EP), a cylinder temperature of 240 ° C., a thickness of 1 mm, 2 mm and 3 mm. Corrugated plates were produced. Using a 2 mm thickness portion of this three-stage plate, measurement was performed using a Nippon Denshoku Industries HAZE meter (NDH-1001DP) in accordance with ASTM D-1003. Here, the center of the 2 mm part was used as the measurement location.
A resin having a total light transmittance of 88% or more is a resin having excellent transparency.
(3) Hue (YI)
With 2mm portion specimens of the (2), Y. in compliance with JIS K-710 5 I. Was measured. Here, the center of the 2 mm part was used as the measurement location.
Y. I. A resin having a value of 4.0 or less was regarded as a resin excellent in hue.
(4) Vicat softening temperature (VSP)
A sample piece of 81.0 mm × 10.0 mm × 4.0 mm was prepared based on ISO-2580-2 and measured according to ISO10350 / ISO306.
(5) Styrene polymerization rate The styrene polymerization rate was determined by measuring and converting residual styrene with the following gas chromatography apparatus.
Equipment: “HP6890” manufactured by Agilent Technology
Column; DB-5 manufactured by J & B
Temperature: 60 ℃ → 200 ℃
Detector; FID
Concentration: about 2.0% by mass
Injection volume: 1 μl
(6) Maleic anhydride polymerization rate The maleic anhydride polymerization rate was determined by measuring and converting residual maleic anhydride with the following liquid chromatography apparatus.
Equipment: “SCL-10AVP” manufactured by Shimadzu Corporation
Column; ODS-A312 manufactured by YMC Corporation
Solvent; water / methanol detection; UV
Concentration: 0.2% by mass
Injection volume: 100 μl
[0028]
[Example 1]
A-1: A 10 liter stainless steel reactor equipped with a stirrer, a heating / cooling device, a thermometer, and a raw material addition device was charged with 90 parts by mass of styrene, maintained at an internal temperature of 112 ° C. in a nitrogen atmosphere, and isobutyl methyl ketone 60 Addition of 0.009 parts by mass / hour of 0.10 parts by mass of peroxyester organic peroxide t-hexylperoxyisopropyl monocarbonate with 10 parts by mass of maleic anhydride and 10 hours half-life temperature of 98.7 ° C. While continuously adding at a rate for 11 hours, polymerization was carried out by heating and stirring. After completion of the addition, stirring was continued for 2 hours to complete the polymerization. Table 1 shows the polymerization rates with time of styrene and maleic anhydride and the consumption reaction rates with time of these monomers. Then, it was charged at 8 L / min into a vented devolatilizing extruder (Ikegai twin-screw extruder PCM-30α modified) at a cylinder temperature of 220 ° C. and a vacuum of 1 KPaA to obtain a polymer A-1. The results are shown in Table 2.
[0029]
[Example 2]
A-2: A 10-liter stainless steel reactor equipped with a stirrer, a heating / cooling device, a thermometer, and a raw material addition device was charged with 0.1 parts by mass of isobutyl methyl ketone and 84 parts by mass of styrene, and the internal temperature was 115 under a nitrogen atmosphere. Maintained at ℃, peroxyester organic peroxide t-hexylperoxyisopropyl monocarbonate 0.15 mass by weight of isobutyl methyl ketone 64.9 mass parts, maleic anhydride 16 mass parts and 10 hours half-life temperature 98.7 ℃ Polymerization was carried out by heating and stirring while continuously adding 11 parts at a rate of 0.014 parts by mass / hour for 11 hours. After completion of the addition, stirring was continued for 2 hours to complete the polymerization. Table 1 shows the polymerization rates with time of styrene and maleic anhydride and the consumption reaction rates with time of these monomers. Then, it was charged at 8 L / min into a vented devolatilizing extruder (Ikegai twin screw extruder PCM-30α modified) at a cylinder temperature of 220 ° C. and a vacuum of 1 KPaA to obtain a polymer A-2. The results are shown in Table 2.
[0030]
[Example 3]
A-3: A 10 liter stainless steel reactor equipped with a stirrer, a heating / cooling device, a thermometer, and a raw material addition device, 0.2 parts by mass of isobutyl methyl ketone, 70 parts by mass of styrene, 3 parts by mass of maleic anhydride, and tarpinolene 0 .018 parts by mass, maintained at an internal temperature of 110 ° C. in a nitrogen atmosphere, 66.8 parts by mass of methyl ethyl ketone, 27 parts by mass of maleic anhydride, and a 10-hour half-life temperature of 101.9 ° C. While continuously adding 0.15 parts by mass of the product t-butyl peroxyacetate at an addition rate of 0.015 parts by mass / hour for 10 hours, the mixture was heated and stirred for polymerization. After completion of the addition, stirring was continued for 2 hours to complete the polymerization. Table 1 shows the polymerization rates with time of styrene and maleic anhydride and the consumption reaction rates with time of these monomers. Thereafter, it was charged at 8 L / min into a vented devolatilizing extruder (Ikegai twin screw extruder PCM-30α modified) at a cylinder temperature of 220 ° C. and a vacuum degree of 1 KPaA to obtain a polymer A-3. The results are shown in Table 2.
[0031]
[Example 4]
A-4: In a 10 liter stainless steel reactor equipped with a stirrer, a heating / cooling device, a thermometer, and a raw material addition device, 0.2 parts by mass of methyl ethyl ketone, 75 parts by mass of styrene, 2 parts by mass of maleic anhydride, α-methylstyrene Peroxyester organic compound charged with 0.010 parts by weight of dimer, maintained at an internal temperature of 110 ° C. in a nitrogen atmosphere, 56.8 parts by weight of methyl ethyl ketone, 23 parts by weight of maleic anhydride, and a 10-hour half-life temperature of 98.7 ° C. While continuously adding 0.10 parts by mass of peroxide t-hexylperoxyisopropyl monocarbonate at an addition rate of 0.009 parts by mass / hour for 11 hours, polymerization was carried out by stirring with heating. After completion of the addition, stirring was continued for 2 hours to complete the polymerization. Table 1 shows the polymerization rates with time of styrene and maleic anhydride and the consumption reaction rates with time of these monomers. Then, it was charged into a vented devolatilizing extruder (Ikegai twin screw extruder PCM-30α modified) at a cylinder temperature of 220 ° C. and a vacuum of 1 KPaA at 8 L / min to obtain a polymer A-4. The results are shown in Table 2.
[0032]
[Comparative Example 1]
B-1: A 10 liter stainless steel reactor equipped with a stirrer, a heating / cooling device, a thermometer, and a raw material addition device was charged with 84 parts by mass of styrene and 0.002 parts by mass of α-methylstyrene dimer, Maintaining the temperature at 115 ° C., 0.54 parts by mass of peroxyester organic peroxide t-hexylperoxyisopropyl monocarbonate having 65 parts by mass of methyl ethyl ketone, 16 parts by mass of maleic anhydride and 10 hours half-life temperature of 98.7 ° C. While continuously adding at an addition rate of 0.054 parts by mass / hour for 10 hours, polymerization was carried out by stirring with heating. After completion of the addition, stirring was continued for 2 hours to complete the polymerization. Table 1 shows the polymerization rates with time of styrene and maleic anhydride and the consumption reaction rates with time of these monomers. Thereafter, it was charged at 8 L / min into a vented devolatilizing extruder (Ikegai twin screw extruder PCM-30α modified) at a cylinder temperature of 220 ° C. and a vacuum of 1 KPaA to obtain a polymer B-1. The results are shown in Table 2.
[0033]
[Comparative Example 2]
B-2: A 10-liter stainless steel reactor equipped with a stirrer, a heating / cooling device, a thermometer, and a raw material addition device was charged with 90 parts by mass of styrene and 0.002 parts by mass of α-methylstyrene dimer, Dialkyl peroxide organic peroxide di-t-butyl peroxide 0.20 part by mass of isobutyl methyl ketone 65 parts by mass, maleic anhydride 10 parts by mass and 10 hour half-life temperature 123.7 ° C. Was continuously stirred for 11 hours at an addition rate of 0.018 parts by mass / hour, followed by polymerization by heating and stirring. After completion of the addition, stirring was continued for 2 hours to complete the polymerization. Table 1 shows the polymerization rates with time of styrene and maleic anhydride and the consumption reaction rates with time of these monomers. Then, it was charged at 8 L / min into a devolatilizing extruder with a vent at a cylinder temperature of 220 ° C. and a vacuum degree of 1 KPaA (Ikegai twin screw extruder PCM-30α modified) to obtain a polymer B-2. The results are shown in Table 2.
[0034]
[Table 1]

[0035]
[Table 2]

[0036]
【The invention's effect】
The present invention controls the addition rate of the organic peroxide with respect to the composition ratio of the aromatic vinyl monomer and the unsaturated carboxylic acid anhydride, the type of organic peroxide, and the consumption reaction rate of the monomer. An aromatic vinyl resin excellent in high molecular weight, high transparency, heat resistance, and hue can be produced.

Claims (1)

Aromatic vinyl monomer (a) 60 to 95 parts by weight, relative to the monomer 100 parts by weight containing 40 to 5 parts by weight unsaturated carboxylic acid anhydride (b), 1 to 100 parts by weight of the ketone a method of solution polymerization using a kind, with respect to the monomer 100 parts by weight, peroxyester organic peroxide 10-hour half-life temperature of 90 ℃ ~110 ℃ (c) 0.008 To 0.50 parts by mass at a rate of addition of 0.001 to 0.018 parts by mass / hour with respect to a consumption reaction rate of 6 to 10 parts by mass / hour of the monomer, 70 parts by weight of the polymerization, then continuously introduced into a vented devolatilizing extruder at a cylinder temperature of 200 to 250 ° C., and, you and removing the volatiles in the following vacuum 40KPaA, weight average molecular weight of from 180,000 to 400,000, ASTM D-1 03 total light transmittance of the thickness of 2mm portion was measured according 88% or higher, Vicat softening temperature of 110 ° C. or higher, and, JIS K-7105 thickness was measured in accordance with of 2mm of the hue ( Y.I.) A process for producing an aromatic vinyl resin having a value of 4.0 or less .