WO2017095099A1 - Method of manufacturing heat-resistant san resin - Google Patents

Abstract

The present disclosure relates to a method of manufacturing a heat-resistant SAN resin, and has the effects of providing: a method of manufacturing a heat-resistant SAN resin, which has excellent productivity, does not emit bad odors during manufacturing, and improves both heat resistance and fluidity; and to a heat-resistant SAN resin manufactured by the method.

Description

Manufacturing method of heat resistant SAN resin

[Reciprocal citation with application (s)]

This application claims the benefit of priority based on Korean Patent Application No. 10-2015-0172718 filed December 04, 2015 and Korean Patent Application No. 10-2016-0159007 filed November 28, 2016. All content disclosed in the literature is included as part of this specification.

The present disclosure relates to a method for manufacturing a heat resistant SAN resin, and more particularly, to a method for preparing a heat resistant SAN resin having excellent productivity and improved heat resistance and fluidity without generating adverse smell during processing, and a heat resistant SAN resin composition prepared therefrom. It is about.

As a conventional technique for improving the heat resistance of acrylonitrile-butadiene-styrene (hereinafter referred to as ABS) resin, a method of preparing by emulsion polymerization by replacing part or all of styrene with α-methylstyrene is commonly used. . Heat-resistant SAN resin is a resin manufactured on the basis of α-methylstyrene, and has a high glass transition temperature and high molecular weight compared to bulk polymerization, and thus has excellent heat resistance and environmental stress crack resistance (ESCR). In particular, the glass transition temperature is the most important factor for determining the heat resistance characteristics of the heat-resisting resin. The method of increasing the α-methylstyrene content or increasing the molecular weight is used in the case of increasing the α-methylstyrene content. Because of its low reactivity, the proportion of unreacted monomers increases, which leads to a decrease in heat resistance. In addition, a separate device for removing unreacted monomers is required, thereby increasing the cost of the product and lowering productivity. This has the disadvantage of being longer and having a lower conversion rate. In addition, when the molecular weight is increased, there is a problem in that the flowability of the applied product is lowered, which may cause a limited portion to increase the molecular weight, and also to increase the content of the molecular weight regulator to lower the molecular weight to improve the fluidity, the molecular weight is mainly used as a molecular weight regulator. There is a problem that the mercaptans to be used produce a bad smell during processing.

In order to solve this problem, Korean Patent Laid-Open Publication No. 199-0021665 discloses a method for preparing a copolymer of α-alkylstyrene-acrylonitrile by emulsion polymerization in the preparation of a heat resistant SAN copolymer, but this manufacturing method In this case, the polymerization time is longer than 9 hours, there is a disadvantage that the copolymer productivity is lowered.

In addition, Korean Patent Laid-Open Publication No. 1996-0031486 discloses a method for adding an electrolyte when preparing a heat-resistant SAN copolymer having a high content of latex solids and excellent stability by emulsion polymerization, but also has a polymerization time of 6 hours. There was a disadvantage in that it takes a long time and the copolymer productivity is lowered.

In order to solve the problems of the prior art as described above, the present invention provides a method for producing a heat-resistant SAN resin with excellent productivity and improved heat resistance and fluidity without adverse smell during processing and a heat-resistant SAN resin composition prepared therefrom For the purpose of

The above and other objects of the present disclosure can be achieved by the present disclosure described below.

In order to achieve the above object, the present invention is a method for producing a heat-resistant SAN resin by polymerizing the α-methylstyrene monomer and vinyl cyan monomer, (i) the entire amount of the α- methyl styrene monomer and part of the vinyl cyan monomer A first polymerization step of polymerizing in the presence of an oxidation-reduction catalyst and a hydroperoxide-based initiator, wherein the polymerization is carried out at the same time as the start of the polymerization or after another part of the vinyl cyan monomer is continuously added after the start of the polymerization; (ii) a second polymerization step in which the oxidation-reduction catalyst and the hydroperoxide-based initiator are polymerized at the time when the polymerization conversion rate reaches 25 to 40% in the first polymerization step; And (iii) a third polymerization step in which the remaining amount of the vinyl cyan monomer and the pyrolysis initiator are polymerized at the time point when the polymerization conversion rate reaches 80 to 90% in the second polymerization step; Provided is a method for producing a heat-resistant SAN resin that does not generate odor and has both improved heat resistance and fluidity.

The present invention also provides a heat resistant SAN resin composition prepared from the method for producing a heat resistant SAN resin.

As described above, according to the present invention, there is an effect of providing a production method of a heat-resistant SAN resin having excellent productivity and improved heat resistance and fluidity without inverse smell during processing and a heat-resistant SAN resin composition prepared therefrom.

Hereinafter, the present description will be described in detail.

The method for producing a heat-resistant SAN resin of the present disclosure is a method for producing a heat-resistant SAN resin by polymerizing an α-methylstyrene monomer and a vinyl cyan monomer, wherein (i) the entire amount of the α-methyl styrene monomer and a part of the vinyl cyan monomer are oxidized. A first polymerization step of polymerizing in the presence of a reduction catalyst and a hydroperoxide-based initiator, wherein the polymerization is carried out simultaneously with the start of the polymerization or after another part of the vinyl cyan monomer is added continuously; (ii) a second polymerization step in which the oxidation-reduction catalyst and the hydroperoxide-based initiator are polymerized at the time when the polymerization conversion rate reaches 25 to 40% in the first polymerization step; And (iii) a third polymerization step in which the remaining amount of the vinyl cyan monomer and the pyrolysis initiator are polymerized at the time point when the polymerization conversion rate reaches 80 to 90% in the second polymerization step. There is an effect that the heat-resistant SAN resin is excellent in productivity while improving the heat resistance and fluidity without generating a bad smell during processing.

As another example, the method for producing a heat-resistant SAN resin of the present invention is a method for producing a heat-resistant SAN resin by polymerizing the α-methylstyrene monomer and vinyl cyan monomer, (i) the entire amount of the α-methylstyrene monomer and the vinyl cyan 20 to 65% by weight of 100% by weight of the monomer is polymerized in the presence of an oxidation-reduction catalyst and a hydroperoxide-based initiator, and 30 to 80% by weight of 100% by weight of the vinyl cyan monomer at the same time as the polymerization start or after the polymerization is started. A first polymerization step of polymerizing while continuously adding 30% or 79% by weight; (ii) a second polymerization step in which the oxidation-reduction catalyst and the hydroperoxide-based initiator are polymerized at the time when the polymerization conversion rate reaches 25 to 40% in the first polymerization step; And (iii) polymerization at a time point when the polymerization conversion ratio reaches 80 to 90% in the second polymerization step, by adding 0 to 25 wt% or 1 to 25 wt% of the remaining 100 wt% of the vinyl cyan monomer and a pyrolysis initiator. It is characterized in that it comprises a; the third polymerization step to be made, there is an effect of producing a heat-resistant SAN resin having excellent productivity within this range and does not generate a bad smell during processing and improved both heat resistance and fluidity.

As another example, the method for producing a heat-resistant SAN resin of the present invention is a method for producing a heat-resistant SAN resin by polymerizing the α-methylstyrene monomer and vinyl cyan monomer, (i) the entire amount of the α-methylstyrene monomer and the vinyl cyan 30 to 60% by weight or 33 to 40% by weight in 100% by weight of the monomer is polymerized in the presence of an oxidation-reduction catalyst and a hydroperoxide-based initiator, and at the same time as the polymerization start or after the polymerization start, 100 weight of the vinylcyan monomer A first polymerization step of polymerizing while continuously adding 30 to 60 wt% or 50 to 56 wt% in%; (ii) a second polymerization step in which the oxidation-reduction catalyst and the hydroperoxide-based initiator are polymerized at the time when the polymerization conversion rate reaches 25 to 40% in the first polymerization step; And (iii) polymerization of the remaining 5 to 15 wt% or 4 to 17 wt% of the 100 wt% of the vinyl cyan monomer, and a thermal decomposition initiator at a time point when the polymerization conversion rate is 80 to 90% in the second polymerization step. It is characterized in that it comprises a; the third polymerization step to be made, there is an effect of producing a heat-resistant SAN resin having excellent productivity within this range and does not generate a bad smell during processing and improved both heat resistance and fluidity.

The vinyl cyan monomer continuously added in step (i) is, for example, 30 minutes to 5 hours, 1 hour to 4 hours, 2 hours to 3.5 hours, or 2 hours to 3 hours after the initiator is added or after the start of polymerization. It can be continuously injected, there is an effect that the heat-resistant SAN resin is excellent in productivity and improved in both heat resistance and fluidity without generating a bad smell during processing within this range.

As another example, the vinyl cyan monomer continuously added in step (i) may reach 20 to 90%, 40 to 90%, 60 to 90% or 70 to 88% of the polymerization conversion rate after the initiator is added or after the polymerization is started. Until the continuous injection, there is an effect that the heat-resistant SAN resin is excellent in productivity and improved in both heat resistance and fluidity without generating a bad smell during processing within this range.

In the present description, 'after the start of the polymerization' or 'after the initiator is added' means a time interval such that a person skilled in the art can immediately input the start of the polymerization, and, for example, a time point of 1 second to 10 minutes after the start of the polymerization, Or 10 seconds to 5 minutes, or more than 0% to 5% or less, or more than 0% to 3%.

Continuous dosing in the present disclosure is not particularly limited in the case of continuous dosing that is commonly recognized in the art, and for example, materials to be added or drop-by-drop while being continuously connected to each other for a predetermined time. ), It may mean that the droplets are continuously injected for a predetermined time at short intervals.

The production method of the heat-resistant SAN resin is, for example, based on a total of 100 parts by weight of α-methylstyrene monomer and vinyl cyan monomer, (i) 65 to 75 parts by weight of the α-methylstyrene, 5 to 15 parts by weight of vinyl cyan monomer, molecular weight 0.01 to 0.3 parts by weight of the regulator, 0.01 to 1.0 parts by weight of the redox catalyst, 0.001 to 0.2 parts by weight of the hydroperoxide initiator, and 1.5 to 2.0 parts by weight of the emulsifier are added and polymerized at the same time, or simultaneously with the start of the polymerization or the start of the polymerization. Thereafter, a first polymerization step of polymerizing while continuously introducing an emulsion containing 10 to 20 parts by weight of the vinyl cyan monomer, 0.5 to 1.0 parts by weight of an emulsifier, and 0 to 0.2 parts by weight of a molecular weight regulator; (ii) a second polymerization step in which the polymerization is performed by adding 0.01 to 1.0 parts by weight of an oxidation-reduction catalyst and 0.01 to 2 parts by weight of a hydroperoxide-based initiator at a time when the polymerization conversion rate reaches 25 to 40% in the first polymerization step. ; And (iii) polymerizing by adding 0 to 4 parts by weight of vinyl cyan monomer, 0.01 to 0.3 parts by weight of pyrolysis initiator, and 0.1 to 0.5 parts by weight of emulsifier at the point of reaching the polymerization conversion ratio of 80 to 90% in the second polymerization step. It may include a third polymerization step.

For example, in step (i), the redox catalyst may be added at 0.01 to 1.0 part by weight, 0.03 to 0.5 part by weight, or 0.05 to 0.3 part by weight together with the hydroperoxide-based initiator, and at a low temperature within this range. Even if the polymerization is shortened the polymerization reaction time has the effect of generating a high molecular weight. The redox catalyst that can be used may be at least one selected from the group consisting of ferrous sulfate, dextrose, sodium pyrophosphate, sodium sulfite, sodium formaldehyde sulfoxylate, and sodium ethylenediaminetetraacetate. .

The heat resistant SAN resin means a copolymer resin of α-methylstyrene monomer-vinyl cyan compound.

The vinyl cyan monomer may be at least one selected from the group consisting of, for example, acrylonitrile, methacrylonitrile, and ethacrylonitrile.

The vinyl cyan monomer to be collectively introduced into the (i) first polymerization step as an example may be 5 to 15 parts by weight, or 7 to 13 parts by weight, and the initial reaction rate is appropriate in this range to facilitate molecular weight control, and polymerization. As the reaction time is shortened, the glass transition temperature is increased.

The vinyl cyan monomer to be collectively introduced into the (i) first polymerization step as an example may have a weight ratio of α-methylstyrene monomer of 0.05 to 0.15, or 0.1 to 0.13, while the polymerization reaction time is shortened within this range There is an effect of increasing the glass transition temperature.

The redox catalyst may be at least one selected from the group consisting of ferrous sulfate, dextrose, sodium pyrophosphate, sodium sulfite, sodium formaldehyde sulfoxylate, and sodium ethylenediamine tetraacetate.

The oxidation-reduction catalyst added in the first polymerization step (i) may be, for example, 0.01 to 1.0 parts by weight, 0.03 to 0.5 parts by weight, or 0.05 to 0.3 parts by weight, and polymerization is carried out at low temperature within this range. As the reaction time is shortened, high molecular weight is produced.

Specific examples of the redox catalyst (i) introduced in the first polymerization step include dextrose, sodium pyrolate, and ferrous sulfate; Or sodium ethylenediaminetetraacetate, sodium formaldehyde sulfoxylate, and ferrous sulfate; and polymerization at low temperatures within this range has an effect of shortening the polymerization reaction time and producing a high molecular weight.

The oxidation-reduction catalyst added in the second polymerization step (ii) may be, for example, 0.01 to 1.0 parts by weight, 0.03 to 0.5 parts by weight, or 0.05 to 0.3 parts by weight, and polymerization is carried out at low temperature within this range. As the reaction time is shortened, high molecular weight is produced.

The oxidation-reduction catalyst introduced in the second polymerization step (ii) includes, for example, dextrose, sodium pyrrolate, and ferrous sulfate; Or sodium ethylenediaminetetraacetate, sodium formaldehyde sulfoxylate, and ferrous sulfate; and polymerization at low temperatures within this range has an effect of shortening the polymerization reaction time and producing a high molecular weight.

The hydroperoxide-based initiator may be at least one selected from the group consisting of, for example, diisopropylbenzene hydroperoxide, cumene hydroperoxide, and tertiary butylhydroperoxide.

The (i) hydroperoxide-based initiator to be added in the first polymerization step may be 0.001 to 0.2 parts by weight, 0.005 to 0.15 parts by weight, or 0.01 to 0.1 parts by weight, the polymerization conversion rate is increased within this range It works.

The hydroperoxide-based initiator added in the second polymerization step (ii) may be, for example, 0.01 to 2 parts by weight, 0.01 to 1 parts by weight, or 0.02 to 0.5 parts by weight, and the polymerization conversion rate is increased within this range. It works.

The pyrolysis initiator may be at least one selected from the group consisting of, for example, potassium persulfate, ammonium persulfate, sodium persulfate, and potassium persulfate.

The pyrolysis initiator may be included only in the (iii) tertiary polymerization step, for example, and may be 0.01 to 0.3 parts by weight, 0.05 to 0.25 parts by weight, or 0.1 to 0.2 parts by weight, and finally within this range. There is an effect of increasing the polymerization conversion rate.

The molecular weight modifier may be at least one selected from the group consisting of n-dodecyl mercaptan, tertiary dodecyl mercaptan, n-tetradecyl mercaptan and tertiary tetradecyl mercaptan.

(I) The molecular weight modifier that is introduced into the first polymerization step in a batch may be 0.001 to 0.3 parts by weight, 0.1 to 0.25 parts by weight, or 0.1 to 0.2 parts by weight, within this range does not occur inverse odor during processing It has an excellent flowability effect without.

(I) The molecular weight regulator included in the emulsion in the first polymerization step may be, for example, 0 to 0.2 parts by weight, 0.01 to 0.2 parts by weight, or 0.1 to 0.2 parts by weight within this range does not cause inverse odor during processing It has an excellent flowability effect without.

As another example, the molecular weight regulator included in the emulsion in the (i) the first polymerization step may not include a molecular weight regulator, there is an effect that the reverse odor does not occur during processing within this range.

Vinyl cyan included in the emulsion in the (i) the first polymerization step may be 10 to 18 parts by weight or 11 to 15, for example, the initial reaction rate is appropriate within this range is easy to control the molecular weight, polymerization reaction As the time is shortened, the glass transition temperature is increased.

The emulsifier may be, for example, an anionic emulsifier or a neutral polymer emulsifier having an allyl group, a (meth) acryloyl group, or a propenyl group.

(I) The emulsion continuously added from the first polymerization step may be added to the point of reaching a polymerization conversion rate of 25 to 90%, 30 to 90%, 50 to 90%, or 80 to 90%, for example, Within this range, polymerization stability is improved and a high molecular weight heat resistant SAN resin is produced.

(I) The emulsion is continuously added from the first polymerization step is 1 to 20 parts by weight, hr, 2 to 16 parts by weight, or based on the total weight of the vinyl cyan monomer, emulsifier and molecular weight regulator included in the emulsion It can be added at 3 to 5 parts by weight / hr, the polymerization stability is improved within this range and there is an effect that a high molecular weight heat-resistant SAN resin is produced.

The batch injection in (i) the first polymerization step may be carried out at 45 to 55 ° C., for example, and polymerization is efficiently performed even at a low temperature within this range, thereby improving production efficiency.

In the (i) first polymerization step, the emulsion may be continuously added, for example, while maintaining ΔT (set temperature—exothermic temperature) at less than 4 ° C. at 60 to 70 ° C.

In the emulsion polymerization of a general heat-resistant SAN resin, the polymerization is carried out at a reaction temperature, that is, a set temperature of 75 to 85 ° C., but the present invention provides a glass transition while the polymerization time is shortened even if the polymerization is performed at a lower temperature, that is, a set temperature of 65 to 75 ° C. There is an effect of increasing the temperature.

The ΔT (set temperature-exothermic temperature) may be, for example, less than 4 ° C., or less than 2 ° C., and polymerization stability is improved and a high molecular weight heat-resistant SAN resin is produced within this range.

The second polymerization step (ii) can be polymerized at, for example, the reaction temperature of 65 to 75 ℃, there is an effect of improving the polymerization stability within this range.

The (ii) second polymerization may be, for example, a polymerization conversion rate of 25 to 40% or 30 to 35%, and there is an excellent balance of polymerization rate and molecular weight increase within this range.

The (iii) tertiary polymerization may be, for example, a polymerization conversion rate of 80 to 90%, or 85 to 90%, and the glass transition temperature is increased within this range, thereby improving heat resistance.

The water (i) used for batch feeding in the first polymerization step may be, for example, 100 to 500 parts by weight, 100 to 300 parts by weight, or 130 to 250 parts by weight based on 100 parts by weight of the total monomers.

The water included in the emulsion in the first polymerization step (i) may be 50 to 300 parts by weight, 50 to 200 parts by weight, 70 to 150 parts by weight, or 80 to 120 parts by weight based on 100 parts by weight of the total monomer, for example. have.

In the third polymerization step (iii), for example, the reaction may be terminated at a polymerization conversion rate of 97% or more, or 97 to 99%.

After the third polymerization step (iii) may include a step of agglomeration by adding 1 to 3 parts by weight of a coagulant.

An example of a drying step after the aggregation; Or drying and aging step; may further include.

The drying may be carried out by, for example, a hot air fluidized bed dryer.

The drying step; Or drying and aging step; after the completion of the heat-resistant SAN resin may be prepared as a powder of moisture content of 1% by weight or less.

The heat resistant SAN resin may have, for example, a weight average molecular weight of 60,000 to 150,000 g / mol, 70,000 to 130,000, or 80,000 to 120,000 g / mol, and within this range, the glass transition temperature and the heat deformation temperature are increased.

For example, the heat-resistant SAN resin may have a glass transition temperature of 140 ° C. or higher, or 140 to 150 ° C., and has excellent heat resistance within this range.

The heat-resistant SAN resin is, for example, the sum of the vinyl cyanated monomer-vinyl cyanated monomer-α-methylstyrene copolymer and the vinyl cyanated monomer-vinyl cyanated monomer-vinyl cyanated monomer copolymer, analyzed by NMR, in an amount of 10% by weight or less and 8% by weight. It may be 1 to 7% by weight or less, and has excellent heat resistance within this range.

The heat-resistant SAN resin composition of the present disclosure includes, for example, 20 to 30 parts by weight of the heat-resistant SAN resin and 70 to 80 parts by weight of the vinyl cyanide compound-conjugated diene compound-aromatic vinyl compound copolymer resin prepared by the method for producing a heat-resistant SAN resin. can do.

The conjugated diene compound is, for example, one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and isoprene It may be abnormal.

The aromatic vinyl compound may be, for example, one or more selected from the group consisting of styrene, α-methylstyrene, o-ethylstyrene, p-ethylstyrene, and vinyltoluene.

The heat resistant SAN resin composition may include, for example, antibacterial agents, heat stabilizers, antioxidants, mold release agents, light stabilizers, surfactants, coupling agents, plasticizers, admixtures, colorants, stabilizers, lubricants, antistatic agents, colorants, flame retardants, weather agents, ultraviolet absorbers, and the like. It may further comprise one or more selected from the group consisting of sunscreen.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

EXAMPLE

Example 1

150 parts by weight of ion-exchanged water, 73 parts by weight of α-methylstyrene, 9 parts by weight of acrylonitrile, 2.0 parts by weight of potassium stearate, and 0.2 parts by weight of tertiary dodecyl mercaptan were added to a nitrogen-substituted reactor for 30 minutes at 50 ° C. After stirring, the redox catalyst composed of 0.02 parts by weight of t-butyl hydroperoxide, 0.035 parts by weight of dextrose, 0.06 parts by weight of sodium pyrophosphate, and 0.0015 parts by weight of ferrous sulfate was collectively administered, and then the reaction set temperature was 65 ° C. ΔT (set temperature-exothermic temperature) is adjusted to 1 ° C or less, an emulsion comprising 100 parts by weight of ion-exchanged water, 15 parts by weight of acrylonitrile and 1.0 parts by weight of potassium stearate was added through a continuous method for 1.0 hour. Then, additional polymerization was carried out while the temperature was raised to 70 ° C. for 2.5 hours (continuous emulsion input). At this time, 1 hour after the start of the polymerization (polymerization conversion rate: 30%), the oxidation-reduction consisting of 0.04 parts by weight of t-butyl hydroperoxide, 0.035 parts by weight of dextrose, 0.06 parts by weight of sodium pyrolate, and 0.0015 parts by weight of ferrous sulfate. It was administered in batches with the catalyst. At the point where all of the emulsion was added (polymerization conversion rate: 88%), the reaction temperature was increased to 75 ° C. for 30 minutes, and 3 parts by weight of acrylonitrile and 0.15 parts by weight of potassium persulfate were added in a batch to perform polymerization.

Example 2

In Example 1, except that 75 parts by weight of α-methylstyrene and 9 parts by weight of acrylonitrile were added at the start of the polymerization, and the emulsion was made of 13 parts by weight of acrylonitrile in a continuous feeding step in the same manner as in Example 1 above. Was carried out.

Reference Example 1

In Example 1, 73 parts by weight of α-methylstyrene and 15 parts by weight of acrylonitrile were added in a batch at the start of polymerization, and 9 parts by weight of acrylonitrile was added thereto, and the emulsion was continuously added for 1 hour in ΔT ( Except that the set temperature-exothermic temperature) was not adjusted to less than 4 ℃ was carried out in the same manner as in Example 1.

Comparative Example 1

In Example 1, except that the initial polymerization temperature was set at 70 ° C. except that potassium persulfate, which is a pyrolysis initiator other than a hydroperoxide-based initiator, was used as the polymerization initiator and the polymerization reaction time was 1 hour. It carried out by the same method as 1.

Comparative Example 2

In Comparative Example 1, the same procedure as in Comparative Example 1 was carried out except that tertiary mercaptan, which was a molecular weight regulator, was used at 0.6 part by weight.

[Test Example]

The properties of the heat-resistant SAN resin compositions prepared in Examples 1 and 2, Reference Examples, and Comparative Examples 1 and 2 were measured by the following methods, and the results are shown in Table 1 below.

* Polymerization conversion rate (%): 1.5 g of the prepared latex was dried in 150 hot air dryers for 15 minutes and then weighed to obtain a total solids content (TSC), and the polymerization conversion rate was calculated by Equation 1 below.

[Equation 1]

Polymerization Conversion Rate (%) = [{(Added Monomer And Subsidiary Parts By Weight) * Total Solid Content (%)-(Extra Monopart Added By Weight Monomer)} / (Total Monomer Input)] * 100

(In case of section polymerization conversion rate, it reflects the monomer part added up to the section)

* Weight average molecular weight (g / mol): The sample was dissolved in THF (tetrahydrofuran) and measured using GPC.

* Glass transition temperature (° C): measured using DSC Q100 (TA Instruments).

Triad content (% by weight): Bruker AVANCE HD III 700MHz NMR instrument was used and the sample was dissolved in CDCl3 (w / TMS) and the NMR spectrum was measured at room temperature. The measured value was obtained by calibrating TMS to 0 ppm and calculating triad sequence distribution based on the integral value of peaks in the range of 150 to 140 ppm and 125 to 118 ppm, and the vinyl cyanated monomer-vinyl cyanated monomer-α-methylstyrene copolymer. And the content of vinyl cyanated monomer-vinyl cyanated monomer-vinyl cyanated monomer copolymer.

* Odor during processing: The odor generated during extrusion and injection was evaluated by sensory evaluation, and if the odor did not occur, it was evaluated as good.

* Fluidity (g / 10min): Measured for 10 minutes at 220 ℃, 10Kg load in accordance with ASTM D1238.

* Heat deflection temperature (° C): measured according to ASTM D648.

division		Example 1	Example 2	Reference Example 1	Comparative Example 1	Comparative Example 2
First polymerization stage (batch input)	α-methylstyrene	73	75	73	73	73
	Acrylonitrile	9	9	15	9	9
	tDDM	0.2	0.2	0.2	0.2	0.6
	Initiator	Redox catalyst, t-BHP	Redox catalyst, t-BHP	Redox catalyst, t-BHP	Potassium persulfate	Potassium persulfate
	Polymerization temperature	65	65	65	70	70
Second polymerization stage (continuous input)	Acrylonitrile	15	11	9	15	15
	Initiator	Redox catalyst, t-BHP	Redox catalyst, t-BHP	Redox catalyst, t-BHP	Potassium persulfate	Potassium persulfate
	Conversion rate	88	85	86	80	78
	△ T	≤ 2 ℃	≤ 1 ℃	4 ℃	6 ℃	6 ℃
3rd polymerization stage (batch input)	Acrylonitrile	3	2	3	3	3
Final conversion rate		98.5	98.0	98.0	97.0	97.0
Weight average molecular weight		120,000	100 thousand	200,000	180,000	120,000
Glass transition temperature		140	143	137	135	129
Triad		5	4	12	14	14
Odor during processing		Good	Good	Good	Good	Role
liquidity		7.2	7.8	4.5	4.8	7.5
Heat deflection temperature		107	106	103	102	99

* t-BHP: t-butyl hydroperoxide

As shown in Table 1, Examples 1 and 2 according to the present invention did not generate inverse odor during processing, a polymer having a weight average molecular weight of 100,000 g / mol or more was produced, and also a triad content is low glass transition The temperature and the heat deformation temperature were increased, and the heat resistance was excellent, but the fluidity was also good.

On the other hand, in Reference Example 1 in which ΔT (set temperature-exothermic temperature) was not adjusted to less than 4 ° C. during the second polymerization step, the weight average molecular weight was increased, but the glass transition temperature, heat deformation temperature, and fluidity were decreased.

In addition, Comparative Examples 1 and 2, which did not use an oxidation-reduction catalyst, had a very large decrease in the glass transition temperature and the heat deformation temperature, and a sharp increase in the triad content.

Claims (20)

1. In the method of polymerizing an α-methylstyrene monomer and a vinyl cyan monomer to produce a heat resistant SAN resin,

   (i) 20 to 65% by weight of the total amount of the α-methylstyrene monomer and 100% by weight of the vinyl cyan monomer are polymerized in the presence of an oxidation-reduction catalyst and a hydroperoxide-based initiator, simultaneously with or at the beginning of the polymerization. A first polymerization step of polymerizing while continuously introducing 30 to 80 wt% of the vinyl cyan monomer 100 wt%;

   (ii) a second polymerization step in which the oxidation-reduction catalyst and the hydroperoxide-based initiator are polymerized at the time when the polymerization conversion rate reaches 25 to 40% in the first polymerization step; And

   (iii) a third polymerization step of polymerizing by adding a thermal decomposition initiator and 0 to 25% by weight of the remaining 100% by weight of the vinyl cyan monomer at the time when the polymerization conversion rate reaches 80 to 90% in the second polymerization step;

   Method for producing a heat-resistant SAN resin comprising a.
2. The method of claim 1,

   The manufacturing method of the heat-resistant SAN resin,

   Based on 100 parts by weight of a total of α-methylstyrene monomer and vinyl cyan monomer,

   (i) 65 to 75 parts by weight of the α-methylstyrene, 5 to 15 parts by weight of vinyl cyan monomer, 0.01 to 0.3 parts by weight of molecular weight regulator, 0.01 to 1.0 parts by weight of redox catalyst, 0.001 to 0.2 parts by weight of hydroperoxide initiator Parts, and 1.5 to 2.0 parts by weight of an emulsifier are added in a batch and polymerized, with 10-20 parts by weight of a vinyl cyan monomer, 0.5 to 1.0 parts by weight of an emulsifier, and 0 to 0.2 parts by weight of a molecular weight modifier simultaneously with or after the start of the polymerization. A first polymerization step of polymerizing while continuously including an emulsion;

   (ii) a second polymerization step in which the polymerization is performed by adding 0.01 to 1.0 parts by weight of an oxidation-reduction catalyst and 0.01 to 2 parts by weight of a hydroperoxide-based initiator at a time when the polymerization conversion rate reaches 25 to 40% in the first polymerization step. ; And

   (iii) an agent which polymerizes by adding 0 to 4 parts by weight of vinyl cyan monomer, 0.01 to 0.3 parts by weight of pyrolysis initiator, and 0.1 to 0.5 parts by weight of emulsifier at the time when the polymerization conversion rate reaches 80 to 90% in the second polymerization step. Tertiary polymerization step;

   Method for producing a heat-resistant SAN resin comprising a.
3. The method of claim 2,

   The vinyl cyan monomer to be collectively introduced in the (i) the first polymerization step is a weight ratio of the α-methylstyrene monomer is 0.05 to 0.15 method for producing a heat-resistant SAN resin.
4. The method of claim 1,

   The redox catalyst is a heat-resistant SAN resin, characterized in that at least one selected from the group consisting of ferrous sulfate, dextrose, sodium pyrophosphate, sodium sulfite, sodium formaldehyde sulfoxylate, and sodium ethylenediaminetetraacetate. Manufacturing method.
5. The method of claim 1,

   The hydroperoxide-based initiator is diisopropylbenzene hydroperoxide, cumene hydroperoxide, and tertiary butylhydro peroxide, the method for producing a heat-resistant SAN resin, characterized in that at least one selected from the group consisting of.
6. The method of claim 1,

   The pyrolysis initiator is a method for producing a heat-resistant SAN resin, characterized in that at least one selected from the group consisting of potassium persulfate, ammonium persulfate, sodium persulfate, and potassium persulfate.
7. The method of claim 2,

   The method of manufacturing a heat-resistant SAN resin, characterized in that the (i) the emulsion is continuously added from the first polymerization step until the point of reaching a polymerization conversion rate of 20 to 90%.
8. The method of claim 2,

   The heat-resistant SAN resin, characterized in that the (i) the emulsion is continuously added from the first polymerization step is added to 1 to 20 parts by weight / hr based on the total weight of the vinyl cyan monomer, emulsifier and molecular weight regulator included in the emulsion. Manufacturing method.
9. The method of claim 1,

   The vinyl cyan monomer is at least one member selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile.
10. The method of claim 2,

    (I) The method of producing a heat-resistant SAN resin, characterized in that the batch input in the first polymerization step is carried out at 45 to 55 ℃.
11. The method of claim 2,

    (I) The method of producing a heat-resistant SAN resin, characterized in that in the first polymerization step, the emulsion is continuously added while maintaining the ΔT (set temperature-exothermic temperature) below 4 ℃ at 60 to 70 ℃.
12. The method of claim 1,

    The second polymerization step (ii) is a method for producing a heat-resistant SAN resin, characterized in that the reaction temperature is polymerized at 65 to 75 ℃.
13. The method of claim 2,

    The molecular weight modifier is a method for producing a heat-resistant SAN resin, characterized in that at least one selected from the group consisting of n-dodecyl mercaptan, tertiary dodecyl mercaptan, n- tetradecyl mercaptan and tertiary tetradecyl mercaptan.
14. The method of claim 2,

    The emulsifier is an anionic emulsifier or a neutral polymeric emulsifier having an allyl group, a (meth) acryloyl group, or a propenyl group.
15. The method of claim 1,

    And (iii) adding 1 to 3 parts by weight of a flocculant to agglomerate the third polymerization step to agglomerate the heat-resistant SAN resin.
16. The method of claim 15,

    Drying and aging step after the aggregation; Or drying step; a method of producing a heat-resistant SAN resin, characterized in that it further comprises.
17. The method of claim 1,

    The heat-resistant SAN resin is a method for producing a heat-resistant SAN resin, characterized in that the weight average molecular weight of 80,000 to 120,000 g / mol.
18. The method of claim 1,

    The heat-resistant SAN resin is a method of producing a heat-resistant SAN resin, characterized in that the glass transition temperature of 140 ℃ or more.
19. The method of claim 1,

    The heat-resistant SAN resin is a heat-resistant SAN characterized in that the sum of the vinyl cyanated monomer-vinyl cyanated monomer-α-methylstyrene copolymer and the vinyl cyanated monomer-vinyl cyanated monomer-vinyl cyanated monomer copolymer analyzed by NMR is 10% by weight or less. Method for producing a resin.
20. Heat-resistant SAN resin comprising 20 to 30 parts by weight of the heat-resistant SAN resin prepared by the method for producing a heat-resistant SAN resin of claim 1 and 70 to 80 parts by weight of vinyl cyanide compound-conjugated diene compound-aromatic vinyl compound copolymer resin Composition.