TWI478946B - Styrene-α-methyl styrene-vinyl cyanide copolymer and rubber-modified styrenic resin - Google Patents

Description

Styrene-α-methylstyrene-acrylonitrile copolymer and rubber modification Styrene resin

The present invention relates to a rubber-modified styrene-based resin, and more particularly to a styrene-α-methyl group mainly composed of a styrene monomer unit, an α-methylstyrene monomer unit, and an acrylonitrile monomer unit. A styrene-acrylonitrile copolymer.

Styrene-based resins (such as ABS resins) are widely used in electrical, electronic and automotive parts, mainly in terms of process formability, physical properties and mechanical properties, especially the good appearance of molded articles. And gloss is a major feature.

On the other hand, in order to improve the appearance of the gate of the injection molded article, the processing and molding industry is gradually adopting a pin gate to inject molding. This trend also makes the styrene resin have thermal stability requirements. improve. Therefore, how to make the styrene-based resin improve the thermal stability of the resin processing is an extremely problem to be improved in the field.

Further, in general, a content of α-methylstyrene monomer unit in a thermoplastic resin composed of a styrene monomer unit, an α-methylstyrene monomer unit, and an acrylonitrile monomer unit. The higher the value, the effect of raising the softening point. Although the heat resistance property of the thermoplastic resin can be improved, there is a disadvantage that the cost rises.

In view of the above, an object of the present invention is to provide a styrene-α-methylstyrene-acrylonitrile-based copolymer and a rubber-modified styrene-based resin to improve the heat resistance of the resin and the increase in cost.

Therefore, in order to achieve the above object, the styrene-α-methylstyrene-acrylonitrile-based copolymer according to the present invention mainly comprises 48 to 60% by weight of styrene monomer units and 15 to 27% by weight of α-methylbenzene. An ethylene monomer unit; and 25 to 32% by weight of an acrylonitrile monomer unit. Among them, the content of the dimer and the trimer composed of the styrene monomer, the α-methylstyrene monomer or the acrylonitrile monomer is less than 8500 ppm. Wherein the styrene-α-methylstyrene-acrylonitrile copolymer is formed by copolymerization of a styrene monomer, an α-methylstyrene monomer, and an acrylonitrile monomer, wherein styrene-α-methylbenzene The ethylene-acrylonitrile-based copolymer mainly consists of a styrene monomer unit, an α-methylstyrene monomer unit, and an acrylic monomer unit. That is, the styrene monomer unit, the α-methylstyrene monomer unit, and the acrylonitrile monomer unit are respectively referred to after copolymerization of a styrene monomer, an α-methylstyrene monomer, and an acrylonitrile monomer. , a structural unit in a styrene-α-methylstyrene-acrylonitrile-based copolymer.

Further, the present invention further provides a styrene-α-methylstyrene-acrylonitrile copolymer mainly comprising 48 to 60% by weight of a styrene monomer unit and 15 to 27% by weight of an α-methylstyrene monomer unit. And 25~32wt% of acrylonitrile monomer units. Among them, the styrene-α-methylstyrene-acrylonitrile-based copolymer has a weight average molecular weight of less than 50,000 and a molecular weight of less than 25%.

Among them, the above styrene-α-methylstyrene-acrylonitrile copolymerization The acrylonitrile monomer unit is preferably acrylonitrile or α-methacrylonitrile. Further, the styrene-α-methylstyrene-acrylonitrile-based copolymer has a sulfur content of 50 to 300 ppm, preferably 110 to 250 ppm.

Further, the present invention further provides a rubber-modified styrenic resin comprising at least 75 to 80% by weight of a styrene-α-methylstyrene-acrylonitrile copolymer (A1), styrene-α-methylbenzene The ethylene-acrylonitrile-based copolymer (A1) is mainly composed of 48 to 60% by weight of a styrene monomer unit, 15 to 27% by weight of an α-methylstyrene monomer unit, and 25 to 32% by weight of an acrylic monomer unit. a composition in which a content of a dimer and a trimer composed of a styrene monomer, an α-methylstyrene monomer or an acrylonitrile monomer is less than 8500 ppm; and a styrene-acrylonitrile copolymerization of 0 to 5 wt% (A2) comprising 65 to 76% by weight of a styrene monomer unit and 24 to 35% by weight of an acrylic monomer unit, wherein the styrene-α-methylstyrene-acrylonitrile copolymer and styrene are The acrylonitrile-based copolymer constitutes a continuous matrix phase; and 20 to 25 wt% of the rubber particles (B) in which the rubber particles are dispersed phases and dispersed in the continuous matrix phase. Wherein, the rubber particles are preferably selected from the group consisting of at least one polymer of 1,3-butadiene, isoprene or a mixture thereof, and the weight average particle diameter of the rubber particles is preferably 0.22 to 0.6 μm, and the acrylic acid is The monomer unit is preferably acrylonitrile or α-methacrylonitrile.

The effect of the present invention is that a styrene-α-methylstyrene-acrylonitrile-based copolymer and a rubber-modified styrene-based resin can achieve a higher softening point by using less α-methylstyrene monomer unit. In order to reduce costs. In addition, the present invention can further reduce the content of residual dimers and trimers, thereby improving the amount of smoke generated during processing (for example, during injection molding) or mold contamination. In addition, styrene-α-methylstyrene-acrylonitrile The sulphur content of the copolymer is from 50 to 300 ppm, preferably from 110 to 250 ppm, so that the styrene-α-methylstyrene-acrylonitrile copolymer can reach a higher heat resistance temperature (lower thermal weight loss).

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

The styrene-α-methylstyrene-acrylonitrile copolymer of the present invention mainly comprises 48 to 60% by weight of styrene monomer units, 15 to 27% by weight of α-methylstyrene monomer units, and 25 to 32% by weight. The composition of the acrylonitrile monomer unit. Among them, the content of the dimer and the trimer composed of the styrene monomer, the α-methylstyrene monomer or the acrylonitrile monomer is less than 8500 ppm.

Further, the present invention further proposes another styrene-α-methylstyrene-acrylonitrile-based copolymer mainly composed of 48 to 60% by weight of styrene monomer units and 15 to 27% by weight of α-methylstyrene monomer. The unit is composed of 25 to 32% by weight of an acrylonitrile-based monomer unit, wherein the styrene-α-methylstyrene-acrylonitrile-based copolymer has a weight average molecular weight of less than 50,000 and a number of molecules of less than 25%.

When the content of the acrylonitrile-based monomer unit is more than 32% by weight, the styrene-α-methylstyrene-acrylonitrile-based copolymer has a poor hue; and when the content of the acrylonitrile-based monomer unit is less than 25% by weight, The styrene-α-methylstyrene-acrylonitrile copolymer has poor chemical resistance. In addition, when α-methyl When the content of the styrene monomer unit is more than 27% by weight, there is a problem of high cost; if the content of the α-methylstyrene monomer unit is less than 15% by weight, the heat resistance of the thermoplastic resin is lowered.

In addition, the physical property test standards of the examples and comparative examples of the present invention are as follows:

1. Melt Flow Rate (MFR, MI, MVR): Tested at 220 ° C × 10 kg according to JIS K-7210, and expressed in g/10 min.

Second, Izod (IZOD) impact strength: tested according to ASTM D-256, expressed in Kg ‧ cm / cm.

3. Weight-average molecular weight (Mw): a weight average molecular weight obtained by using a commercially available standard styrene calibration curve to obtain a gel with differential tortuosity monitoring and light scattering monitoring. A dialysis chromatograph (Gel Permeation Chromatogrpahy, GPC, supplied by Waters Company) was used.

4. Test method for total content of dimer and trimer of styrene monomer and/or acrylonitrile monomer: 1 g of Examples A1-1 to A1-4 and Comparative Examples A2-1 to A2, respectively. -2 was dissolved in acetone, and the resin composition solution was further analyzed by a gas chromatograph equipped with a flame ionization detector of Hewlett Packard Co., Ltd. No. 7890A.

5. Softening point temperature, refers to Vicat Softening Temperature: Tested in accordance with ASTM D-1525, the unit is expressed in °C.

Sixth, thermal weight loss: using TAQ5000 thermogravimetric analyzer, preparation 5 The weight loss of the sample was measured under a nitrogen atmosphere at 300 ° C for 30 minutes.

7. Sulfur content: Prepare a sample of 10 mg, which is treated with a high temperature furnace (Mitsubishi AQF-100) at 900~1000 °C, and then injected into the 5c.c absorption liquid through a gas absorption unit (Gas Absorption Unit, supplied by Mitsubishi GA-100). The absorption liquid is arranged by taking 1c.c. potassium dihydrogen phosphate (KH ₂ PO ₄ ) and 100 ml of hydrogen peroxide (H ₂ O ₂ ), and quantifying into 1 L with pure water; at this time, the concentration of PO ₄ ^3- is 1 ppm. ) and measured by ion chromatography (DIONEX ICS-1500) with PO ₄ ^3- as internal standard 1 ppm and 1000 ppm sulfate (SO ₄ ^2- ) solution as standard. The standard of different known concentrations [SO ₄ ^2- ] was measured and the corresponding measurement area was measured to develop a [SO ₄ ^2- ] calibration curve. The calibration curve [SO ₄ ^2- ] concentration is calculated as {[sample area] - [background value area]} ^* 5000 / sample weight (in ppm). The sample to be tested is [sample area] and then substituted into the calibration curve to obtain the corresponding [SO ₄ ^2- ], which is then converted to [S]=[SO ₄ ^2- ]/3 (in ppm).

Further, the present invention further provides a rubber-modified styrene-based resin comprising at least 75 to 80% by weight of a styrene-α-methylstyrene-acrylonitrile-based copolymer (A1), wherein styrene-α-methyl The styrene-acrylonitrile copolymer (A1) mainly comprises 48 to 60% by weight of styrene monomer units, 15 to 27% by weight of α-methylstyrene monomer units, and 25 to 32% by weight of acrylonitrile monomer units. a composition in which a dimer and a trimer composed of a styrene monomer, an α-methylstyrene monomer or an acrylonitrile monomer are less than 8500 ppm; and 0 to 5 wt% of a styrene-acrylonitrile copolymer (A2), the styrene-acrylonitrile copolymer (A2) contains 65 to 76% by weight of styrene monomer units and 24 to 35% by weight of acrylonitrile monomer units, of which styrene-α-A The styrene-acrylonitrile copolymer and the styrene-acrylonitrile copolymer constitute a continuous matrix phase; and 20 to 25 wt% of the rubber particles (B), wherein the rubber particles are dispersed phases and dispersed in the continuous matrix phase .

Hereinafter, the styrene-α-methylstyrene-acrylonitrile-based copolymer (A1), the styrene-acrylonitrile-based copolymer (A2), and the rubber particles (B) will be described in detail:

[Styrene-α-methylstyrene-acrylonitrile copolymer (A1)]

The styrene-α-methylstyrene-acrylonitrile-based copolymer (A1) is mainly composed of a styrene monomer, an α-methylstyrene monomer, and an acrylonitrile-based monomer. It is obtained by polymerization.

Preferably, the total amount of the first monomer component consisting of styrene monomer, α-methylstyrene monomer, and acrylonitrile monomer is 100 wt%, and the first monomer component is The content of the styrene monomer may range, for example, from 47% by weight to 59% by weight; more preferably from 48.5% by weight to 53.5% by weight. Further, in the first monomer component, the content of the α-methylstyrene monomer may range, for example, from 14% by weight to 26% by weight; more preferably from 16.5% by weight to 21.5% by weight.

The acrylonitrile-based monomer may be used singly or in combination, and the acrylonitrile-based monomer may include, but not limited to, acrylonitrile or α-methacrylonitrile. Preferably, the acrylonitrile-based monomer can be, for example, acrylonitrile. Preferably, the total content of the acrylonitrile monomer in the first monomer component is calculated by the total amount of the styrene monomer, the α-methylstyrene monomer, and the acrylonitrile monomer being 100 wt%. It may be, for example, 27% by weight to 34% by weight; more preferably 29% by weight to 32% by weight.

In the solution polymerization reaction, a polymerization initiator may be optionally added. The polymerization initiator may, for example, be selected from monofunctional polymerization initiators, polyfunctionality A polymerization initiator, or a combination thereof. The monofunctional polymerization initiator may be used singly or in combination, and the monofunctional polymerization initiator may include, for example, but not limited to, benzoyl peroxide, dicumyl peroxide, T-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxybenzoate (t-butyl) -peroxy benzoate), bis-2-ethylhexyl peroxy dicarbonate, tert-butyl peroxy isopropyl carbonate (BPIC) Cyclohexanone peroxide, 2,2'-azo-bis-isobutyronitrile (AIBN), 1,1'-azobiscyclohexane-1 - 1,1'-azo-biscyclohexane-1-carbonitrile, or 2,2'-azo-bis-2-methylbutyronitrile Wait. Among them, the polymerization initiator may be, for example, benzamidine peroxide or 2,2'-azo-bis-isobutyronitrile.

The polyfunctional polymerization initiator may be used singly or in combination, and the polyfunctional polymerization initiator may include, for example, but not limited to 1,1-bis-tert-butylperoxycyclohexane (1,1-bis-t-). Butyl peroxy cyclohexane (TX-22), 1,1-bis-tert-butylperoxy-3,3,5-trimethylcyclohexane (1,1-bis-t-butylperoxy-3,3,5 -trimethyl cyclohexane, referred to as TX-29A), 2,5-dimethyl-2,5-bis-(2-ethylperoxyhexane)hexane [2,5-dimethyl-2,5-bis-( 2-ethylhexanoxy peroxy)hexane], 4-(tert-butylperoxycarbonyl)-3-hexyl-6-[7-(tert-butylperoxycarbonyl)heptyl]cyclohexane {4-(t-butyl peroxy) Carbonyl)-3-hexyl-6-[7-(t-butyl peroxy carbonyl)heptyl]cyclohexane}, di-t-butyl-diperoxyazelate, 2,5- Dimethyl-2,5-bis(benzoquinone peroxy)hexane, di-tert-butylperoxide-hexahydro- Di-t-butyl peroxy-hexahydro-terephthalate (BPHTH), or 2,2-bis(4,4-di-tert-butylperoxy)cyclohexylpropane [2,2-bis- (4,4-di-t-butyl peroxy)cyclohexyl propane, abbreviated as PX-12].

In the solution polymerization, a chain transfer agent may be optionally added, for example. The chain transfer agent may be used singly or in combination, and the chain transfer agent may include, for example, but not limited to, n-dodecyl mercaptan (NDM), stearyl mercaptan, ortho- T-dodecyl mercaptan (TDM), n-propyl mercaptan, n-octyl mercaptan, tert-octyl mercaptan, tert-mercapto mercaptan, or terpinolene ( Terpinolene) and so on.

Preferably, the operating temperature range of the solution polymerization reaction may be, for example, from 90 ° C to 130 ° C; more preferably, the operating temperature range of the solution polymerization reaction may be, for example, from 100 ° C to 120 ° C.

[Styrene-acrylonitrile copolymer (A2)]

One of the processes for producing the styrene-acrylonitrile-based copolymer (A2) may be composed of a styrene-based monomer (i-1) and an acrylonitrile-based monomer (i-2), and optionally other copolymerizable monomers. The second monomer component of the vinyl monomer (i-3) is obtained by solution polymerization. In addition, styrene-acrylonitrile copolymer (A2) It may also be an ungrafted styrene-acrylonitrile-based copolymer (A2) which is produced when the rubber particles (B) in the emulsion-polymerized rubber graft copolymer are produced.

The styrene monomer (i-1) may be used singly or in combination, and the styrene monomer (i-1) may include, for example, but not limited to, styrene, α-methylstyrene, p-tert-butylstyrene. , p-methylstyrene, o-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, α-methyl-p-methylstyrene, or Bromostyrene and the like. Preferably, the styrenic monomer (i-1) may, for example, be selected from the group consisting of styrene, α-methylstyrene, or a combination thereof. Preferably, the content of the styrenic monomer (i-1) may be, for example, 50% by weight to 90% by weight based on the total amount of (i-1), (i-2), (i-3) of 100% by weight. More preferably, it may be, for example, 55 wt% to 85 wt%; still more preferably, it may be, for example, 58 wt% to 80 wt%.

The acrylonitrile-based monomer (i-2) may be used singly or in combination, and the acrylonitrile-based monomer (i-2) may include, for example, but not limited to, acrylonitrile or α-methacrylonitrile. Preferably, the acrylonitrile-based monomer (i-2) may be, for example, acrylonitrile. Preferably, the content of the acrylic monomer (i-2) may be, for example, 10% by weight to 50% by weight based on the total amount of (i-1), (i-2), (i-3) of 100% by weight. More preferably, it may be, for example, 15% by weight to 45% by weight; still more preferably, it may be, for example, 20% by weight to 42% by weight.

The other copolymerizable vinyl monomer (i-3) may be used singly or in combination, and the other copolymerizable vinyl monomer (i-3) may include, but not limited to, an acrylic monomer or a methacrylic acid. A monomer, an acrylate monomer, a maleimide monomer, a anhydrous maleic acid or a methacrylate monomer. Preferably, the total amount of (i-1), (i-2), (i-3) is 100 wt% The content of the other copolymerizable vinyl monomer (i-3) may be, for example, from 0% by weight to 40% by weight; more preferably, for example, from 1% by weight to 34% by weight; more preferably, for example, for example It is 3 wt% to 30 wt%.

The acrylic monomer may include, for example, but not limited to, acrylic acid or the like. The methacrylic monomer may include, for example, but not limited to, methacrylic acid or the like. The acrylate monomer may include, for example, but not limited to, methyl acrylate, ethyl acrylate, isopropyl acrylate, or butyl acrylate. Preferably, the acrylate monomer may be, for example, butyl acrylate.

The methacrylate monomer may include, but is not limited to, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, hexyl methacrylate, Cyclohexyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate Methacrylate), ethylene dimethacrylate, or neopentyl dimethacrylate. Preferably, the methacrylate monomer may, for example, be selected from methyl methacrylate or butyl methacrylate.

The maleimide-based monomer can be, for example, maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N -Hexylmaleimide, N-octylmaleimide, N-dido-maleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N -2,3-tolyl-maleimide, N-2,4-tolyl-maleimide, N-2,3-ethylphenylmaleimide, N-2,4-ethylbenzene Kamalyzide, N-2,3-butylphenylmaleimide, N-2,4-butylphenylmaleimide, N-2,6-methylphenylmaleimide, N-2,3- Chlorophenylmaleimide, N-2,4-chlorophenylmaleimide, N-2,3-bromophenylmaleimide, N-2,4-bromophenylmale The imine or the like, among which N-phenylmaleimide is most preferred.

The kind of the polymerization initiator and the chain transfer agent are the same as those of the polymerization initiator and the chain transfer agent in the above-mentioned styrene-α-methylstyrene-acrylonitrile-based copolymer (A1), and therefore will not be described again.

Preferably, the operating temperature range of the solution polymerization reaction may be, for example, 70 ° C to 140 ° C; more preferably, the operating temperature range of the solution polymerization reaction may be, for example, 90 ° C to 130 ° C.

[Rubber particles (B)]

The graft copolymer prepared by the rubber particles (B) is obtained, for example, by graft polymerization of 10 to 60 wt% of a functional monomer component in the presence of a rubber emulsion (solid content) of 40 to 90% by weight. . Wherein, the functional monomer component comprises a monomer mixture which can be, for example, 50 to 90% by weight of the styrene monomer, 10 to 50% by weight of the acrylonitrile monomer, and 0 to 40% by weight of the other copolymerizable vinyl monomer. .

Preferably, the functional monomer component may, for example, comprise 58 wt% to 80 wt% of a styrene monomer, 20 wt% to 42 wt% of an acrylic monomer, and 0 wt% to 22 wt% of another copolymerizable single. body.

In the graft polymerization, an additive may be selectively added, and the additive may include, for example, but not limited to, an emulsifier, a polymerization initiator or a chain transfer agent, and the like. After the emulsion polymerization reaction, it can be selectively condensed, dehydrated, Dry and other steps. The obtained emulsion polymer rubber graft copolymer contains rubber particles (B) and a styrene-acrylonitrile copolymer (A2). After the graft polymerization reaction, the content of the styrene-acrylonitrile-based copolymer is in the range of 10% by weight or less based on the total amount of the emulsion-polymerized rubber graft copolymer (I) of 100% by weight.

The rubber emulsion is obtained by an emulsion polymerization method from the rubber component, or further subjected to an agglomerating treatment after the emulsion polymerization reaction, and optionally adding other copolymerizable monomers in the emulsion polymerization reaction. Preferably, the rubber component may, for example, be selected from a diene rubber, a polyacrylate rubber, or a polyoxyalkylene rubber.

The diene rubber may be used singly or in combination, and the diene rubber may include, for example, but not limited to, butadiene rubber, isoprene rubber, chloroprene rubber, ethylene-propylene-diene terpolymer rubber. (ethylene propylene diene terpolymer, abbreviated as EPDM), or styrene-diene rubber or acrylonitrile-diene rubber. Among them, the butadiene rubber may include, for example, but not limited to, a high cis (Hi-Cis) content of butadiene rubber and a low cis (Low-Cis) content of butadiene rubber. The typical weight composition of cis (Cis)/vinyl (Vinyl) in high cis-butadiene rubber is (94~98 wt%) / (1~5 wt%), and the rest of the composition is trans ( Trans) structure, and mooney viscosity is between 20 and 120, and the molecular weight range is preferably from 100,000 to 800,000. The typical weight composition of cis/vinyl in low cis content butadiene rubber ranges from (20 to 40 wt%) / (1 to 20 wt%), the rest is trans structure, and the Mooney viscosity is 20 Between ~120, the molecular weight range is preferably from 100,000 to 800,000. The styrene-diene rubber may, for example, include but is not limited to styrene-butadiene rubber Glue, styrene-isoprene rubber or the like, and the styrene-diene rubber may be, for example, a block copolymer, a random copolymer or a star type. Among them, in the styrene-butadiene rubber, the weight ratio of styrene to butadiene may range, for example, from 5:95 to 80:20, and the molecular weight range is preferably from 50,000 to 600,000. Preferably, the styrene-diene rubber may be, for example, a styrene-butadiene rubber. Other copolymerizable monomers may include, but are not limited to, a styrene monomer, an acrylonitrile monomer, a (meth) acrylate monomer, and the like. The diene rubber emulsion may, for example but not limited to, be a polybutadiene, a butadiene-styrene copolymer, a butadiene-acrylonitrile copolymer, a butadiene-methyl methacrylate copolymer, or an isoprene Meta-diene-butyl acrylate copolymer and the like.

The hypertrophy treatment can be carried out by a general method of freezing fat, mechanical fat or additive hypertrophy. The additive used in the additive hypertrophy method may include, for example but not limited to, (1) an acidic substance: acetic anhydride, hydrogen chloride, sulfuric acid, etc.; (2) a salt-based substance: sodium chloride, potassium chloride, calcium chloride, etc.; A polymer condensate containing a carboxylic acid group: a (meth)acrylic acid-(meth) acrylate copolymer (e.g., methacrylic acid-butyl acrylate copolymer, methacrylic acid-ethyl acrylate copolymer).

For example, the method for producing a diene rubber emulsion can be carried out by emulsion polymerization using a diene monomer (for example, butadiene), or 50 to 100 wt% of a diene monomer and 0 to 50 wt%. A monomer such as styrene and/or acrylonitrile is polymerized by an emulsion polymerization method to obtain a diene rubber emulsion having a weight average particle diameter of 0.05 μm to 0.6 μm. Further, the monomer may be obtained by emulsion polymerization to obtain a small particle size diene rubber emulsion having a weight average particle diameter of 0.05 μm to 0.20 μm, and then subjected to hypertrophy treatment to obtain the aforementioned small particle size diene rubber. The latex emulsion is a large-sized diene rubber emulsion having a weight average particle diameter of 0.22 μm to 0.6 μm. Wherein, if the rubber particles are less than 0.22 μm, the strength of the impact resistance is lowered due to the rubber particles being too small under the weight of the same rubber particles; on the contrary, if the rubber particles are larger than 0.6 μm, the amount of the rubber particles is the same under the weight of the same rubber particles. Decrease, and the strength of impact resistance is reduced.

Styrene-based monomer, acrylonitrile-based monomer, copolymerizable monomer, polymerization initiator, chain transfer agent, and styrene-propylene used in the graft copolymer prepared from the rubber particles (B) The monomers in the nitrile-based copolymer (A2) are exemplified the same, and are not described herein again.

In the process of preparing the rubber-modified styrene-based resin of the present invention, various additives may be added as necessary, and the additive may be selected, for example, from an antioxidant, a plasticizer, a processing aid, a UV stabilizer, an ultraviolet absorber, a filler, and a reinforcement. Agents, colorants, slip agents, charge inhibitors, flame retardants, flame retardant aids, heat stabilizers, couplers, or combinations thereof. The above additives may be respectively polymerized in the polymerization reaction of the above styrene-α-methylstyrene-acrylonitrile copolymer (A1), styrene-acrylonitrile copolymer (A2) or rubber particles (B), after polymerization. Adding before the coagulation, or the above additives may be added during the process of performing the extrusion kneading treatment to prepare the rubber-modified styrene-based resin.

The antioxidant may be used singly or in combination, and the antioxidant may include, for example, but not limited to, a phenolic antioxidant, a thioether antioxidant, or a phosphorus antioxidant. Preferably, the antioxidant is contained in an amount of 2 wt% or less based on 100% by weight of the total amount of the rubber-modified styrene resin. Phenol system The antioxidant may be used singly or in combination, and the phenolic antioxidant may include, for example, but not limited to, octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionate [3] ,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanoic acid octadecyl ester, model: antioxidant IX-1076], triethylene glycol bis[3-(3-tert-butyl-5-methyl-4- Hydroxyphenyl)propionate], tetrakis[Methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 2-tert-butyl-6-(3- tert-Butyl-2-hydroxy-6-methylbenzyl)-4-methylphenyl acrylate, 2,2'-methylene-bis(4-methyl-6-tert-butylphenol) [ 2,2'-methylenebis(4-methyl-6-tert-butylphenol), model: antioxidant 2246], 2,2'-thiobis(4-methyl-6-tert-butylphenol), 2,2' - thio-diethylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], or 2,2'-ethylenediamine-bis[ethyl- 3-(3,5-bis-tert-butyl-4-hydroxyphenyl)propionate].

The thioether-based antioxidants may be used singly or in combination, and the thioether-based antioxidants may, for example, include, but are not limited to, distearyl thiodipropionate, dipalmitosulfur dipropionate, pentaerythritol-tetra-( --dodecyl-thiopropionate, or dioctadecyl sulfide, and the like.

The phosphorus-based antioxidant may be used singly or in combination, and the phosphorus-based antioxidant may be selected from a phosphite-containing phosphorus-based antioxidant or a phosphate-containing phosphorus-based antioxidant. The phosphite-containing phosphorus-based antioxidant may, for example, include, but is not limited to, tris(nonylphenyl) phosphite, dodecyl phosphite, 4,4'-butylene bis(3-methyl-6- Tert-butylphenyl-bistridecylphosphite), tris(2,4-tert-butylphenyl)phosphite, and the like. Phosphate-containing phosphorus-based antioxidants may, for example, include, but are not limited to, tetrakis(2,4-tert-butylphenyl)-4,4'-extended biphenyl Phosphate, or 9,10-dihydro-9-oxy-10-phosphate phenanthrene-10-oxygen and the like.

The slip agent may be used singly or in combination, and the slip agent may include, for example, but not limited to, a metal soap such as calcium stearate, magnesium stearate, lithium stearate, or ethylene bis-stearamide. EBA), methylene distearylamine, decyl palmitate, butyl stearate, palmitate stearate, pentaerythritol tetra-fatty acid ester, polypropionic acid tristearate, n-docosanoic acid, A compound such as stearic acid, a polyethylene wax, a octadecanoic acid wax, a carnuba wax, a petroleum wax or the like. Preferably, the content of the lubricant is in the range of 2% by weight or less based on the total amount of the rubber-modified styrene resin of 100% by weight.

In the process of preparing the rubber-modified styrene-based resin of the present invention, various polymers may be added as necessary, and the polymer may include, for example, but not limited to, polycarbonate, polyamine, polyethylene terephthalate, poly Butylene terephthalate, polyphenylene ether, polyvinyl chloride, polymethyl methacrylate, ethylene-methyl methacrylate copolymer, polypropylene, styrene-butadiene block copolymer, hydrogenation An acrylonitrile-butadiene copolymer, a hydrogenated styrene-butadiene block copolymer, and the like. Preferably, the content of the polymer ranges from 5 wt% to 200 wt%, based on the total amount of the rubber-modified styrene resin of 100% by weight.

The molded article of the rubber-modified styrene-based resin of the present invention is obtained by subjecting the rubber-modified styrene-based resin as described above to a kneading process. The kneading processing and molding process can be carried out in a manner known in the prior art, and therefore will not be described again.

The invention will be further illustrated by the following examples, but it should be understood These examples are for illustrative purposes only and are not to be construed as limiting the invention.

<Example> <Example A1-1>

The raw materials of 21.5 wt% of α-methylstyrene monomer, 48.5 wt% of styrene monomer, and 30 wt% of acrylonitrile monomer were mixed at a rate of 27 kg/hr, and then ethylbenzene was 3.0 kg/hr, 620 ppm. Azobisisobutyronitrile (AIBN), 550 ppm of t-dodecyl mercaptan (TDM), and a recovery liquid formed by condensation of the volatiles removed by the reaction described later are combined as a feed liquid to be supplied to the internal temperature. Maintaining a continuous kettle type reaction tank with a stirrer at a temperature of 130 ° C and a volume of 40 liters, and keeping the proportion of ethylbenzene in the reaction liquid at 16%, while maintaining the conversion rate at 55% (the amount of monomers in the tank is 45%, the amount of polymer is 55%).

When the reaction liquid is removed by a devolatilization apparatus, a pellet of a styrene-α-methylstyrene-acrylonitrile-based copolymer can be obtained. Wherein the styrene-α-methylstyrene-acrylonitrile-based copolymer contains 22.5 wt% of α-methylstyrene monomer units, 49 wt% of styrene monomer units, and 28.5% by weight of acrylonitrile. Monomer unit. On the other hand, the removed volatile component is condensed by a condenser as a recovery liquid, and continuously mixed with the above raw material mixture; this method adjusts the reaction rate by the amount of azobisisobutyronitrile (AIBN), or adjusts A styrene-α-methylstyrene-acrylonitrile copolymer having a melt flow index of 1.8 (A1-1) at a rate of about 27 kg/hr, based on the amount of t-dodecyl mercaptan (TDM) ).

Further, the weight average molecular weight of Example A1-1 was 106,000, and oligomerization was carried out. The content of the Oligomer was 8500 ppm and the softening point was 113.3 °C. The sulfur content was 114 ppm. The thermogravimetric loss at 300 ° C was 5.1%.

<Example A1-2>

Mixing 21.5 wt% of α-methylstyrene monomer, 48.5 wt% of styrene monomer, and 30 wt% of acrylonitrile monomer at a rate of 27 kg/hr, and then adding 3.0 kg/hr and 650 ppm of azobenzene to ethylbenzene. Diisobutyronitrile (AIBN), 650 ppm of t-dodecyl mercaptan (TDM), and the recovered liquid formed by condensation of the volatiles removed by the reaction described later are combined as a feed liquid, and the supply temperature is maintained at A continuous kettle type reaction tank with a stirrer at a temperature of 120 ° C and a volume of 40 liters, and maintaining the proportion of ethylbenzene in the reaction liquid at 16%, while maintaining the polymerization rate at 55% (the amount of monomers in the tank is 45%) The amount of the polymer is 55%).

When the reaction liquid is removed by a devolatilization apparatus, a pellet of a styrene-α-methylstyrene-acrylonitrile-based copolymer can be obtained. Wherein the styrene-α-methylstyrene-acrylonitrile-based copolymer contains 22.5 wt% of α-methylstyrene monomer units, 49 wt% of styrene monomer units, and 28.5% by weight of acrylonitrile. Monomer unit. On the other hand, the removed volatile component is condensed by a condenser as a recovery liquid, and continuously mixed with the above raw material mixture; this method adjusts the reaction rate by the amount of azobisisobutyronitrile (AIBN), or adjusts a quantity of tert-dodecyl mercaptan (TDM), and a styrene-α-methylstyrene-acrylonitrile copolymer having a melt flow index of 1.8 at a rate of about 27 kg/hr (A1-2) ).

Further, in Example A1-2, the weight average molecular weight was 11,000,000, and the polymer having a weight average molecular weight of less than 50,000 was 23.8 wt%, and the oligomer (Oligomer) The content was 6500 ppm and the softening point was 113.7 °C. The sulfur content was 132 ppm. The thermogravimetric loss at 300 ° C was 4.8%.

<Example A1-3>

The raw materials of α-methylstyrene monomer 16.5 wt%, styrene monomer 53.5 wt%, and acrylonitrile monomer 30 wt% were mixed at a rate of 27 kg/hr, and then ethylbenzene 3.0 kg/hr and 710 ppm azo were mixed. Diisobutyronitrile (AIBN), 800 ppm of t-dodecyl mercaptan (TDM), and the recovered liquid formed by condensation of the volatiles removed by the reaction described later are combined as a feed liquid, and the supply temperature is maintained at A continuous kettle type reaction tank with a stirrer at a temperature of 130 ° C and a volume of 40 liters, and maintaining the proportion of ethylbenzene in the reaction liquid at 16%, while maintaining the polymerization rate at 55% (the amount of monomers in the tank is 45%) The amount of the polymer is 55%).

When the reaction liquid is removed by a devolatilization apparatus, a pellet of a styrene-α-methylstyrene-acrylonitrile-based copolymer can be obtained. Wherein the styrene-α-methylstyrene-acrylonitrile-based copolymer contains 17.5 wt% of α-methylstyrene monomer units, 54 wt% of styrene monomer units, and 28.5 wt% of acrylonitrile. Monomer unit. On the other hand, the removed volatile component is condensed by a condenser as a recovery liquid, and continuously mixed with the above raw material mixture; this method adjusts the reaction rate by the amount of azobisisobutyronitrile (AIBN), or adjusts a quantity of t-dodecyl mercaptan (TDM), and a styrene-α-methylstyrene-acrylonitrile copolymer having a melt flow index of 1.8 at a rate of about 27 kg/hr (A1-3) ).

Further, the weight average molecular weight of Example A1-3 was 113,000, the content of the oligomer (Oligomer) was 6000 ppm, and the softening point was 113.5 °C. The sulfur content was 182 ppm. The thermogravimetric loss at 300 ° C was 4.1%.

<Example A1-4>

The raw materials of α-methylstyrene monomer 16.5 wt%, styrene monomer 53.5 wt%, and acrylonitrile monomer 30 wt% were mixed at a rate of 27 kg/hr, and then ethylbenzene 3.0 kg/hr and 770 ppm azo were mixed. Diisobutyronitrile (AIBN), 1000 ppm of t-dodecyl mercaptan (TDM), and the recovered liquid formed by condensation of the volatiles removed by the reaction described later are combined as a feed liquid, and the supply temperature is maintained at A continuous kettle type reaction tank with a stirrer at a temperature of 120 ° C and a volume of 40 liters, and maintaining the proportion of ethylbenzene in the reaction liquid at 16%, while maintaining the polymerization rate at 55% (the amount of monomers in the tank is 45%) The amount of the polymer is 55%).

When the reaction liquid is removed by a devolatilization apparatus, a pellet of a styrene-α-methylstyrene-acrylonitrile-based copolymer can be obtained. Wherein the styrene-α-methylstyrene-acrylonitrile-based copolymer contains 17.5 wt% of α-methylstyrene monomer units, 54.5 wt% of styrene monomer units, and 28.0 wt% of propylene. Nitrile monomer unit. On the other hand, the removed volatile component is condensed by a condenser as a recovery liquid, and continuously mixed with the above raw material mixture; this method adjusts the reaction rate by the amount of azobisisobutyronitrile (AIBN), or adjusts a quantity of tert-dodecyl mercaptan (TDM), and a styrene-α-methylstyrene-acrylonitrile copolymer having a melt flow index of 1.8 at a rate of about 27 kg/hr (A1-4) ).

In addition, the weight average molecular weight of Example A1-4 was 119,000, and the polymer having a weight molecular weight of less than 50,000 was 22.5 wt%, and the oligomer (Oligomer) The content was 4,200 ppm and the softening point was 114 °C. The sulfur content was 211 ppm. The thermogravimetric loss at 300 ° C was 3.6%.

<Comparative Example A2-1>

The raw materials of 68 wt% of styrene monomer and 32 wt% of acrylonitrile monomer were mixed at a rate of 27 kg/hr, and then ethylbenzene 3.0 kg/hr, 150 ppm azobisisobutyronitrile (AIBN), 1500 ppm untwisted-twelfth The alkyl mercaptan (TDM), and the recovered liquid formed by the condensation of the volatiles removed by the reaction described later, are combined as a feed liquid to supply a continuous mixer with an internal temperature of 130 ° C and a volume of 40 liters. The kettle type reaction vessel was maintained at a ratio of 5% in the reaction liquid, and the polymerization rate was maintained at 55% (the amount of the monomer in the tank was 45%, and the amount of the polymer was 55%).

After the reaction liquid is removed by a devolatilization apparatus, the pellets are extruded and granulated to obtain a pellet of a styrene-acrylonitrile-based copolymer. Among them, the particles of the styrene-acrylonitrile-based copolymer contained 72% by weight of styrene monomer units and 28.0% by weight of acrylonitrile monomer units. On the other hand, the removed volatile component is condensed by a condenser as a recovery liquid, and continuously mixed with the above raw material mixture; this method adjusts the reaction rate by the amount of azobisisobutyronitrile (AIBN), or adjusts The amount of t-dodecyl mercaptan (TDM) was used to prepare a styrene-acrylonitrile-based copolymer (A2-1) having a melt flow index of 1.8 at a rate of about 27 kg/hr.

Further, Comparative Example A2-1 had a weight average molecular weight of 147,000, an oligomer (Oligomer) content of 7700 ppm, and a softening point of 110 °C.

<Comparative Example A2-2>

Α-methylstyrene monomer 32wt%, benzene at a rate of 27kg/hr The raw materials of 34 wt% of ethylene monomer and 34 wt% of acrylonitrile monomer were mixed, and then 3.0 kg/hr of ethylbenzene, 520 ppm of azobisisobutyronitrile (AIBN), and 1000 ppm of t-dodecyl mercaptan (TDM) were mixed. And the recovered liquid formed by condensing the volatiles removed by the reaction described later is combined as a feed liquid, and is supplied to a continuous kettle type reaction tank with a stirrer maintained at an internal temperature of 130 ° C and having a volume of 40 liters. The proportion of ethylbenzene in the reaction solution was maintained at 16%, and the polymerization rate was maintained at 55% (the amount of the monomer in the tank was 45%, and the amount of the polymer was 55%).

When the reaction liquid is removed by a devolatilization apparatus, a pellet of a styrene-α-methylstyrene-acrylonitrile-based copolymer can be obtained. Wherein the styrene-α-methylstyrene-acrylonitrile-based copolymer contains 36% by weight of α-methylstyrene monomer units, 36% by weight of styrene monomer units, and 28.0% by weight of acrylonitrile single particles. Body unit. On the other hand, the removed volatile component is condensed by a condenser as a recovery liquid, and continuously mixed with the above raw material mixture; this method adjusts the reaction rate by the amount of azobisisobutyronitrile (AIBN), or adjusts A styrene-α-methylstyrene-acrylonitrile copolymer having a melt flow index of 1.8 (A2-2) at a rate of about 27 kg/hr, based on the amount of t-dodecyl mercaptan (TDM). Comparative example.

Further, Comparative Example A2-2 had a weight average molecular weight of 105,000, a weight molecular weight of less than 50,000, a polymer of 26% by weight, an oligomer (Oligomer) content of 14,000 ppm, and a softening point of 114.1 °C. The sulfur content was 8 ppm. The thermogravimetric loss at 300 ° C was 6.1%.

<Synthesis Example B1>

First, 95.0 parts by weight of 1,3-butadiene, 5.0 parts by weight of acrylonitrile, 15.0 parts by weight of a potassium persulfate 1% solution, 2 parts by weight of potassium oleate, 140.0 parts by weight of distilled water, and t-dodecyl mercaptan were prepared. 0.2 parts by weight.

According to the above formulation, the reaction was carried out at a reaction temperature of 65 ° C for 12 hours to obtain a synthetic rubber latex having a conversion ratio of 94%, a solid content of about 36%, and a weight average particle diameter of 0.1 μm.

Further, a carboxylic acid group-containing polymer flocculant was produced by the following components: 85 parts by weight of n-ethyl acrylate, 15 parts by weight of acrylic acid, 0.3 parts by weight of t-dodecylmercaptan, 2.0 parts by weight of potassium oleate, and 1.0 parts by weight of sodium octylsulfosuccinate, 0.4 parts by weight of cumene hydroperoxide, 0.3 parts by weight of sodium formaldehyde sulfoxylate, and 200 parts by weight of distilled water.

According to the above formula, the reaction was carried out at a reaction temperature of 75 ° C for 5 hours to obtain a carboxylic acid group-containing polymer flocculant having a conversion ratio of 95% and a pH of 6.0.

Next, 3 parts by weight of a carboxylic acid group-containing polymer flocculant (dry weight) is used to ferment 100 parts by weight of the synthetic rubber latex (dry weight), and the obtained enlarged rubber emulsion has a pH of 8.5 and a weight average particle size. The diameter is 0.30 μm.

Finally, the rubberized emulsion of the hypertrophic rubber emulsion was subjected to the following formulation to produce the rubber particles (B) of the present invention: the weight of the hypertrophic rubber latex (dry weight) was 100.0 parts by weight, the styrene was 25.0 parts by weight, and the propylene was used. 8.3 parts by weight of a nitrile, 1.2 parts by weight of potassium oleate, 0.2 parts by weight of t-dodecyl mercaptan, 0.5 parts by weight of cumene hydroperoxide, 3.0 parts by weight of a ferrous sulfate solution (0.2% by weight), and formaldehyde 3.0 parts by weight of sodium hyposulfite solution (10% by weight), 20.0 parts by weight of ethylenediaminetetraacetic acid solution (0.25% by weight), and 200.0 parts by weight of distilled water.

The styrene/acrylonitrile in the above formula is added to the reaction system for polymerization within 5 hours in a continuous manner, and the obtained rubber graft emulsion is coagulated with calcium chloride (CaCl 2 ), dehydrated, and then dried to a moisture content of 2 Below the %, the rubber particles (B) required in the present invention can be obtained. After dissolving <synthesis example B1> by tetrahydrofuran and filtering, methanol was added to the filtrate to precipitate rubber particles (B) and filtered, and the obtained <synthesis example B1> was calculated to contain 7 wt% of styrene-propylene. The nitrile-based copolymer (A2) and 93% by weight of the rubber particles (B) had a weight average particle diameter of the rubber particles of 0.30 μm. Among them, the styrene-acrylonitrile-based copolymer (A2) contains 65 to 76% by weight of a styrene monomer unit and 24 to 35% by weight of an acrylonitrile monomer unit.

<Example C1-1>

76 wt% of the styrene-α-methylstyrene-acrylonitrile-based copolymer (A1) obtained from <Example A1-1> was mixed with <Synthesis Example B1>24 wt%, and 0.7 part by weight of a slip agent was added. And 0.3 part by weight of a mixture containing a phenolic antioxidant and a phosphorus-based antioxidant, and melt-mixed and extruded into a granulated extruder (Werner & Pfleiderer ZSK 35). A rubber-modified styrene-based resin composition (C1-1) having a rubber particle (B) content of 22 by weight was obtained.

Then, after the test piece was shot at 220 ° C in an injection molding machine of the company's factory number SM-90, a molded article of a rubber-modified styrene resin was obtained. The analysis and physical property evaluation results are shown in Table 2. Example C1 The melt flow index (MI) of -1 was 7.9 g/10 min, the Izod impact strength (IZOD) was 22 kg ‧ cm/cm, and the softening point was 113 °C.

<Example C1-2>

76 wt% of the styrene-α-methylstyrene-acrylonitrile-based copolymer (A1) obtained from <Example A1-2> was mixed with <Synthesis Example B1>24 wt%, and 0.7 part by weight of a slip agent was added. And 0.3 part by weight of a mixture containing a phenolic antioxidant and a phosphorus-based antioxidant, and melt-mixed and extruded into a granulated extruder (Werner & Pfleiderer ZSK 35). A rubber-modified styrene-based resin composition (C1-2) having a rubber particle (B) content of 22% by weight was obtained.

Then, after the test piece was shot at 220 ° C in an injection molding machine of the company's factory number SM-90, a molded article of a rubber-modified styrene resin was obtained. The analysis and physical property evaluation results are shown in Table 2. Example C1 The melt flow index (MI) of -2 was 7.9 g/10 min, the Izod impact strength (IZOD) was 22.1 kg ‧ cm/cm, and the softening point was 113.8 °C.

<Example C1-3>

76 wt% of the styrene-α-methylstyrene-acrylonitrile-based copolymer (A1) obtained from <Example A1-3> was mixed with <Synthesis Example B1>24 wt%, and 0.7 part by weight of a slip agent was added. And 0.3 part by weight of a mixture containing a phenolic antioxidant and a phosphorus-based antioxidant, and melt-mixed and extruded into a granulated extruder (Werner & Pfleiderer ZSK 35). A rubber-modified styrene-based resin composition (C1-3) having a rubber particle (B) content of 22% by weight was obtained.

Then, after the test piece was shot at 220 ° C in an injection molding machine of the company's factory number SM-90, a molded article of a rubber-modified styrene resin was obtained. The analysis and physical property evaluation results are shown in Table 2. Example C1 -3 melting The melt flow index (MI) was 6.5 g/10 min, the Izod impact strength (IZOD) was 22.9 Kg ‧ cm/cm, and the softening point was 113.5 °C.

<Example C1-4>

76 wt% of the styrene-α-methylstyrene-acrylonitrile-based copolymer (A1) obtained from <Example A1-4> was mixed with <Synthesis Example B>24 wt%, and 0.7 part by weight of a slip agent was added. And 0.3 part by weight of a mixture containing a phenolic antioxidant and a phosphorus-based antioxidant, and melt-mixed and extruded into a granulated extruder (Werner & Pfleiderer ZSK 35). A rubber-modified styrene-based resin composition (C1-4) having a rubber particle (B) content of 22% by weight was obtained.

Then, after the test piece was shot at 220 ° C in an injection molding machine of the company's factory number SM-90, a molded article of a rubber-modified styrene resin was obtained. The analysis and physical property evaluation results are shown in Table 2. Example C1 The melt flow index (MI) of -4 was 6.8 g/10 min, the Izod impact strength (IZOD) was 24 kg ‧ cm/cm, and the softening point was 114 °C.

<Comparative example z1-1>

76 wt% of the styrene-acrylonitrile copolymer prepared by <Comparative Example A2-1> was mixed with <Synthesis Example B1>24 wt%, 0.7 part by weight of a slip agent was added, and 0.3 part by weight of a phenolic antioxidant and phosphorus were contained. A mixture of antioxidants was melt-mixed and extruded into pellets by a vented extruder (Werner & Pfleiderer ZSK 35). A comparative example of the rubber-modified styrene-based resin composition (z1-1) having a rubber particle (B) content of 22 by weight was obtained.

Next, take the injection molding machine of the company's factory number SM-90. After the test piece was ejected at 220 ° C, a molded article of a rubber-modified styrene-based resin was obtained, and the analysis and physical property evaluation results are shown in Table 2. The melt flow index (MI) of Comparative Example z1-1 was 5.7 g/10 min, Izo The tensile strength (IZOD) was 28 Kg ‧ cm/cm and the softening point was 110 °C.

<Comparative example z1-2>

76 wt% of the styrene-α-methylstyrene-acrylonitrile-based copolymer prepared by <Comparative Example A2-2> was mixed with <Synthesis Example B1>24 wt%, 0.7 parts by weight of a slip agent was added, and 0.3 wt%. The mixture contains a mixture of a phenolic antioxidant and a phosphorus-based antioxidant, and is melt-mixed and extruded into a granule by an extruder equipped with a vent (Werner & Pfleiderer ZSK 35). A comparative example of the rubber-modified styrene-based resin composition (z1-2) having a rubber particle (B) content of 22 by weight was obtained.

Then, after the test piece was shot at 220 ° C by the injection molding machine of the company's factory number SM-90, the molded article of the rubber-modified styrene resin was obtained. The analysis and physical property evaluation results are shown in Table 2, Comparative Example z1. The melt flow index (MI) of -2 was 7.7 g/10 min, the Izod impact strength (IZOD) was 21.7 Kg ‧ cm/cm, and the softening point was 114 °C.

In <Synthesis Example B1>, a part of the styrene-acrylonitrile-based copolymer (A2) was about 7 wt% of <Synthesis Example B1> (that is, rubber particles (B) accounted for 93% of <Synthesis Example B1>). . Among them, the styrene-acrylonitrile-based copolymer (A2) contains 75 wt% of a styrene monomer unit and 25 wt% of an acrylonitrile monomer unit. In other words, when 76% by weight of Examples A1-1 to A1-4 were each mixed with 24% by weight of Synthesis Example B1 to form Examples C1-1 to C1-4, respectively, the styrene-acrylonitrile-based copolymer (A2) About the hair The rubber modified styrene resin was 1.7 wt%.

Referring to Tables 1 and 2, Table 1 is a styrene-α-methylstyrene-acrylonitrile copolymer of the present invention, Examples A1-1 to A1-4 and Comparative Examples A2-1 to A2-2. Comparison Chart. Wherein, the composition of the feed represents a composition weight ratio before the reaction of the first monomer component mainly composed of the acrylonitrile monomer, the styrene monomer, and the α-methylstyrene monomer; the composition of the particles (Pellet) The compositional weight ratio of the acrylonitrile monomer unit, the styrene monomer unit, and the α-methylstyrene monomer unit of the first monomer component after polymerization; A α S physical property indicates each embodiment or each comparison The physical properties of the examples; AN/SM/α MS indicates the wt% of the acrylonitrile monomer unit/styrene monomer unit/methylstyrene monomer unit; EB indicates the proportion of ethylbenzene in the reaction liquid. Maintaining the ratio; Mw represents the average molecular weight of each of the examples or comparative examples; Mw < 50,000 represents the percentage of the molecular weight of less than 50,000 in each of the examples or comparative examples; the oligomer represents styrene monomer, α-methyl a content of a dimer and a trimer composed of a styrene monomer or an acrylonitrile monomer; SP represents a softening point temperature; a sulfur content means that the sulfur content is expressed in ppm in each of the examples or comparative examples; and TGA represents a thermogravi Loss, ie the weight loss of the sample at a constant temperature of 300 ° C for 30 minutes under nitrogen percentage. Table 2 is a comparison table of Examples C1-1 to C1-4 and Comparative Examples z1-1 to z1-2 of the rubber-modified styrene-based resin of the present invention. Here, the ABS composition/physical property indicates the composition/physical property of each of the examples and the comparative examples; BP (B) refers to the ratio used in <Synthesis Example B1>; MI indicates the melt flow index; and IZOD Izod impact strength.

From the comparison of Examples A1-1 to A1-4 with Comparative Examples A2-1 to A2-2, it is understood that the styrene-α-methylstyrene-acrylonitrile-based copolymer of the present invention has less α-methylbenzene. The ethylene monomer unit component (17.5% or 22.5%), but its softening point temperature is close to having a large amount of α-methylstyrene monomer unit component (36%). Further, the styrene-α-methylstyrene-acrylonitrile-based copolymer of the present invention has a sulfur content of 50 to 300 ppm, preferably 110 to 250 ppm, and may be a styrene-α-methylstyrene-acrylonitrile system. The copolymer reached a higher heat resistance temperature (300 ° C thermogravimetric loss was 3.6% to 5.1%, lower than the comparative example). Further, according to the embodiment A1-1 to The result measured by A1-4, if the reaction temperature is lowered to 120 ° C, the softening point temperature will also increase.

In general, in order to increase the heat resistant temperature of the heat resistant resin, that is, the softening point (SP) temperature, it is generally required to increase the amount of the α-methylstyrene monomer unit, and the usual use amount is about 60% by weight of α-methylbenzene. The proportion of ethylene monomer units. As is clear from Comparative Examples z1-1 and z1-2, the softening point temperature at which the α-methylstyrene monomer unit was not added was 110 ° C, and the softening point temperature at which 36 wt% of the α-methylstyrene monomer unit was added was 114 ° C, but its thermal weight loss at 300 ° C reached 6.1%.

In other words, if it is based on the general prior art argument, if the ratio of the α-methylstyrene monomer unit is reduced, the softening point should be lowered. However, the styrene-α-methylstyrene-acrylonitrile-based copolymer of the present invention prepared according to Examples A1-1 to A1-4, although the ratio of the α-methylstyrene monomer units is only 22.5 wt% and 17.5 wt%, and the softening point temperature is between 113.3 and 114 °C. Furthermore, this phenomenon also occurs in the embodiments of C1-1 to C1-4. It can be seen that the styrene-α-methylstyrene-acrylonitrile copolymer and the rubber-modified styrene resin of the present invention reduce the amount of the α-methylstyrene monomer unit, and the softening point thereof is close to or The softening point of the thermoplastic resin equal to the higher amount of the α-methylstyrene monomer unit. In other words, the styrene-α-methylstyrene-acrylonitrile-based copolymer and the rubber-modified styrene-based resin of the present invention have an unexpected effect.

It is speculated that the content of the oligomer (Oligomer) is lowered by reducing the amount of the α-methylstyrene monomer in the first monomer component, which in turn helps The rise in softening point. Here, the oligomer described herein means a dimer and a trimer composed of a styrene monomer, an α-methylstyrene monomer or an acrylonitrile monomer.

Further, the difference between Example A1-1 and A1-2 was the difference in reaction temperature, wherein the reaction temperature of Example A1-1 was 130 ° C; and the reaction temperature of Example A1-2 was 120 °C. As can be seen from the experimental data, the decrease in the reaction temperature reduces the content of the oligomer, and therefore, the decrease in the reaction temperature causes the softening point to rise. This phenomenon also occurred in Examples A1-3 and A1-4. Further, since Examples C1-1 to C1-4 were each composed of Synthesis Examples B1 by Examples A1-1 to A1-4, Example C1 was The softening point of -1 to C1-4 also has an effect of increasing the softening point due to a decrease in the reaction temperature.

The foregoing is illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the appended claims.

Claims (10)

A styrene-α-methylstyrene-acrylonitrile copolymer mainly comprising 48 to 60% by weight of styrene monomer units; 15 to 27% by weight of α-methylstyrene monomer units; and 25 to 32% by weight The composition of the acrylonitrile monomer unit, wherein the content of the dimer and the trimer composed of the styrene monomer, the α-methylstyrene monomer or the acrylonitrile monomer is less than 8500 ppm. The styrene-α-methylstyrene-acrylonitrile-based copolymer according to claim 1, wherein the acrylonitrile-based monomer unit is acrylonitrile or α-methacrylonitrile. The styrene-α-methylstyrene-acrylonitrile copolymer according to claim 1, wherein the styrene-α-methylstyrene-acrylonitrile copolymer has a sulfur content of 110~ 250ppm. A styrene-α-methylstyrene-acrylonitrile copolymer mainly comprising 48 to 60% by weight of styrene monomer units; 15 to 27% by weight of α-methylstyrene monomer units; and 25 to 32% by weight The composition of the acrylonitrile-based monomer unit, wherein the styrene-α-methylstyrene-acrylonitrile-based copolymer has a weight average molecular weight of less than 50,000 and the number of molecules is less than 25%. The styrene-α-methylstyrene-acrylonitrile-based copolymer according to claim 4, wherein the acrylonitrile-based monomer unit is acrylonitrile or α-methacrylonitrile. The styrene-α-methylstyrene-acrylonitrile copolymer according to claim 4, wherein the sulphur content of the styrene-α-methylstyrene-acrylonitrile copolymer is 110~ 250ppm. A rubber modified styrene resin comprising at least 75 to 80% by weight of a styrene-α-methylstyrene-acrylonitrile copolymer, and the styrene-α-methylstyrene-acrylonitrile copolymer is mainly It consists of 48-60wt% styrene monomer unit, 15~27wt% α-methylstyrene monomer unit and 25~32wt% acrylonitrile monomer unit, including styrene monomer and α-甲The content of the dimer and trimer composed of the styrene monomer or the acrylonitrile monomer is less than 8500 ppm; 0 to 5 wt% of the styrene-acrylonitrile copolymer, containing 65 to 76 wt% of the styrene series a unit cell and 24 to 35 wt% of an acrylic monomer unit, wherein the styrene-α-methylstyrene-acrylonitrile copolymer and the styrene-acrylonitrile copolymer form a continuous matrix phase; and 20~ 25 wt% of rubber particles, wherein the rubber particles are in a dispersed phase and dispersed in the continuous matrix phase. The rubber-modified styrene-based resin according to claim 7, wherein the rubber particles are a polymer of 1,3-butadiene, isoprene or a mixture thereof. The rubber-modified styrene-based resin according to claim 7, wherein the rubber particles have a weight average particle diameter of 0.22 to 0.6 μm. The rubber-modified styrene-based resin according to claim 7, wherein the acrylonitrile-based monomer unit is acrylonitrile or α-methacrylonitrile.