KR20180062649A - Method for preparing heat resistance san resin, method for preparing resin composition comprising the same resin and method for preparing molding product - Google Patents

Abstract

The present invention relates to a method of producing a heat resistant SAN-based resin, and methods of producing a resin composition comprising the heat resistant SAN-based resin and an injection molded product comprising the heat resistant SAN-based resin. More specifically, the present invention relates to a method of a high quality heat resistant SAN-based resin with excellent heat resistance, mechanical properties, productivity and other properties at high productivity by adjusting pH values within a specific range, thereby improving polymerization conversion rate and polymerization stability in a process of emulsion polymerizing raw materials including (meth)acrylic acid with excellent heat resistance when producing the SAN-based resin. According to the present invention, the resin composition comprising the heat resistant SAN-based resin produced by the method has an advantage that the resin composition not only is very excellent in heat resistance by having a heat distortion temperature (HDT) of 110°C or higher, but also is excellent in mechanical properties by having a tensile strength of 550 kg/cm^2 or more.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing a heat-resistant SAN resin, a resin composition including the same,

The present invention relates to a method for producing a heat-resistant SAN resin, a resin composition containing the heat-resistant SAN resin, and a method for producing an injection-molded article. More particularly, the present invention relates to a heat- Resistant SAN based resin which is excellent in mechanical properties such as tensile strength and excellent in stability of emulsion polymerization latex and can provide a high-quality heat-resistant SAN-based resin with high productivity. .

As a conventional technique for improving the heat resistance of a styrene-acrylonitrile resin (SAN series resin) or a heat resistant ABS resin composition containing the styrene-acrylonitrile resin (SAN series resin), a method of replacing a part or all of styrene with an alpha-alkylstyrene is generally used .

The heat resistance of the resin or resin composition obtained by this method is determined mainly by the content of alpha-alkylstyrene. The higher the content of alpha-alkylstyrene, the higher the heat resistance. However, the reactivity of alpha-alkylstyrene itself is low, As the content increased, the reactivity with acrylonitrile copolymerized deteriorated, so that the polymerization rate and the polymerization conversion rate were lowered, and the ratio of the unreacted monomers was increased to limit the amount thereof. There is a problem that the heat resistance of the resulting copolymer is difficult to exceed 110 ° C.

Korean Patent No. 10-0788742

In order to solve the problems of the prior art as described above, it is an object of the present invention to provide a method for manufacturing a SAN-based resin capable of producing a SAN-based resin having excellent heat resistance and mechanical properties such as tensile strength with high productivity do.

Further, the present invention provides a technique relating to a heat-resistant SAN resin composition and a method of manufacturing an injection-molded article, including heat-resistant SAN-based resin and greatly improved heat resistance such as heat distortion temperature, mechanical strength such as tensile strength, .

These and other objects of the present invention can be achieved by the present invention described below.

In order to attain the above object, the present invention provides a process for producing a polyurethane foam, which comprises a) 50 to 70 parts by weight of an aromatic vinyl compound, 20 to 35 parts by weight of a vinyl cyan compound and 3 to 15 parts by weight of (meth) acrylic acid, based on 100 parts by weight of the total amount of monomers used A polymerization step for emulsion polymerization; b) adjusting the pH to 2 to 7.5 by adding a pH adjusting agent during the emulsion polymerization; And c) terminating the polymerization reaction at the time when the polymerization conversion rate exceeds 90%. The present invention also provides a method for producing a heat-resistant SAN resin.

The present invention also relates to a process for kneading and extruding 10 to 40% by weight of a heat-resistant SAN resin, 30 to 70% by weight of an aromatic vinyl compound-vinyl cyanide copolymer and 10 to 40% by weight of an ABS resin, The present invention also provides a method for producing a heat-resistant SAN resin composition.

Further, the present invention provides a method for producing an injection molded article, which comprises the step of injecting a heat resistant SAN resin composition according to the above production method.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to produce a SAN resin having a high polymerization conversion, a high glass transition temperature, a high weight average molecular weight, and improved heat resistance by emulsion polymerization including (meth) acrylic acid having a high heat resistance.

Further, there is provided a high-quality heat-resistant resin composition and an injection-molded product excellent in heat resistance such as heat distortion temperature including heat-resistant SAN resin according to the present invention and excellent in mechanical properties such as tensile strength and appearance quality .

The present inventors have found that when an aromatic vinyl compound and a vinyl cyanide compound are polymerized, methacrylic acid having a high heat resistance is controlled to have a pH within a specific range and emulsion polymerization can be carried out to secure polymerization stability, It is confirmed that a heat-resistant SAN resin having a significantly improved transition temperature can be produced, and the present invention has been completed on the basis thereof.

The heat-resistant SAN resin composition of the present invention comprises a) 50 to 70 parts by weight of an aromatic vinyl compound, 20 to 35 parts by weight of a vinyl cyan compound and 3 to 15 parts by weight of (meth) acrylic acid based on 100 parts by weight of the total of monomers used, A polymerization step to polymerize; b) adjusting the pH to 2 to 7.5 by adding a pH adjusting agent during the emulsion polymerization; And c) terminating the polymerization reaction at the time when the polymerization conversion rate exceeds 90%.

In the present invention, the polymerization conversion rate can be calculated by the following formula (1) after measuring the initial weight of the polymerized latex, drying it in a 165 占 폚 hot air drier for 20 minutes, and then measuring the weight of the solid content.

[Equation 1]

Polymerization Conversion (%) = (weight of solid content / initial weight of latex) X 100

Hereinafter, the heat-resistant SAN resin composition of the present invention will be described in detail in each step.

a) emulsion polymerization step

The emulsion polymerization step of the present invention comprises polymerizing 50 to 70 parts by weight of an aromatic vinyl compound, 20 to 35 parts by weight of a vinyl cyan compound and 3 to 15 parts by weight of (meth) acrylic acid based on 100 parts by weight of the total of monomers used, When the monomer components are within the above range, there is an advantage that the polymerization efficiency is excellent and the heat resistance property, mechanical strength and physical property balance are excellent.

In another example, the emulsion polymerization step may be carried out by polymerizing 55 to 70 parts by weight of an aromatic vinyl compound, 20 to 30 parts by weight of a vinyl cyan compound and 5 to 12 parts by weight of (meth) acrylic acid. Within this range, And excellent in physical properties such as heat resistance and mechanical strength.

As another example, it may be preferable to polymerize the emulsion polymerization step comprising 63 to 68 parts by weight of an aromatic vinyl compound, 22 to 27 parts by weight of a vinyl cyan compound and 5 to 10 parts by weight of (meth) acrylic acid, , There is an effect that the polymerization stability is excellent, the heat resistance property is improved, and the mechanical strength is excellent.

As used herein, the term "aromatic vinyl compound" refers to an aromatic vinyl compound, unless otherwise specified, of an alpha-methylstyrene, alpha-ethylstyrene, para-methylstyrene, para-ethylstyrene, ortho-ethylstyrene, 2,4-dimethylstyrene, , And may be optionally used in admixture with styrene, and preferably includes at least one of alpha-methylstyrene or alpha-ethylstyrene.

In the present description, a derivative means a compound in which a hydrogen atom or an atomic group of the original compound is substituted with another atom or atomic group, for example, a compound substituted with a halogen or an alkyl group.

The aromatic vinyl compound is preferably used in an amount of 50 to 70 parts by weight based on 100 parts by weight of the monomers used in the emulsion polymerization. Within this range, the glass transition temperature of the final resin is high and the heat resistance is improved and the polymerization efficiency is excellent .

In the present description, the vinyl cyan compound may be at least one kind selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile and derivatives thereof, unless otherwise specified, and preferably includes acrylonitrile .

The vinyl cyanide compound is preferably used in an amount of 20 to 35 parts by weight based on 100 parts by weight of the total amount of the monomers used in the emulsion polymerization. Within this range, the vinyl cyanide compound has excellent polymerization efficiency and excellent appearance quality But also has an excellent coloring property.

In addition, the vinyl cyanide compound may be added all at the initial stage of polymerization or may be separately added in accordance with the polymerization conversion ratio, and preferably, the vinyl cyanide compound is added in portions. When the vinyl cyanide compound is added in portions, the polymerization efficiency is high and the polymerization efficiency is high, and productivity is improved.

For example, the vinyl cyanide compound may be added in an amount of 10 to 25 parts by weight at the initial stage of the reaction, and the remaining amount may be added at a polymerization conversion of 25 to 45%. In this case, There is an effect that the external appearance characteristics of the display device are improved.

In the present invention, (meth) acrylic acid may be at least one member selected from the group consisting of acrylic acid, methacrylic acid and derivatives thereof, and it may be preferable to include methacrylic acid in order to improve reaction efficiency and heat resistance have.

It is preferable that the (meth) acrylic acid is used in an amount of 3 to 15 parts by weight based on 100 parts by weight of the total amount of the monomers used in the emulsion polymerization. Within this range, the heat resistance of the final resin can be greatly improved .

In the emulsion polymerization step, polymerized water is used as a reaction medium, and the (meth) acrylic acid is characterized in that the hydrophilic property predominates over the aromatic vinyl monomer or the vinyl cyan monomer so that polymerization is carried out in the aqueous phase.

In the present invention, the weight ratio of the polymerization water and the (meth) acrylic acid may be in the range of 6: 1 to 60: 1, more preferably 10: 1 to 20: 1. Within this range, there is an advantage that the stability of the polymerization reaction and the polymerization efficiency are excellent, and the heat resistance property of the final resin is improved.

The polymerization step of the present invention is a step of polymerizing an aromatic vinyl compound, a vinyl cyan compound and a (meth) acrylic acid monomer mixture in the presence of an emulsifier, an initiator and a molecular weight modifier, optionally including an electrolyte and an oxidation- .

In the present invention, the emulsifier is not particularly limited as long as it is an emulsifier commonly used in the technical field to which the present invention belongs, and can be appropriately selected and used. Preferably, the emulsifier has a pH of 1 to 5 At least one selected from the group consisting of sodium laurylsulfonate, sodium alkylbenzenesulfonate, sodium dodecyl allylsulfosuccinate and the like which can have stability within a range of from 1 to 20, and further includes rosin acid salts, fatty acid salts, But it is not limited to these.

The amount of the emulsifier to be used may be 1 to 5 parts by weight or 2 to 3 parts by weight based on 100 parts by weight of the total amount of the monomers. Within the above range, the stability of the latex is excellent and the properties of the injection- There is an advantage in that the appearance quality is excellent.

In the present description, unless otherwise specified, the initiator is selected from the group consisting of cumene hydroperoxide, diisopropylbenzene hydroperoxide, azobisisobutyronitrile, tertiary butyl hydroperoxide, para-methane hydroperoxide and benzoyl peroxide But it is not limited thereto.

The initiator may be used in an amount of 0.01 to 0.5 parts by weight or 0.1 to 0.3 parts by weight based on 100 parts by weight of the total amount of the monomers. This has an excellent effect.

In the present description, unless otherwise specified, the molecular weight modifier may be selected from the group consisting of tertiary dodecylmercaptan, tertiary tetradecylmercaptan, n-tetradecylmercaptan, n-octylmercaptan, sec-octylmercaptan, n- -Decylmercaptan, decylmercaptan, n-dodecylmercaptan and n-octadecylmercaptan, and preferably includes tertiary dodecylmercaptan.

The amount of the molecular weight regulator may be 0.1 to 3 parts by weight or 0.3 to 1 part by weight based on 100 parts by weight of the total amount of the monomers. Within this range, the degree of polymerization is uniform without deteriorating the physical properties of the final resin .

The electrolyte is not otherwise specified in this disclosure _{KCl, NaCl, KHCO 3, NaHCO} 3, K 2 CO 3, Na 2 CO 3, KHSO 3, NaHSO 3, K 4 P 2 O 7, Na 4 P 2 O 7, K ₃ PO ₄ , Na ₃ PO ₄ , K ₂ HPO ₄ and Na ₂ HPO ₄ .

The electrolyte may be used in an amount of 0.01 to 0.5 parts by weight or 0.05 to 0.3 parts by weight based on 100 parts by weight of the total amount of the monomers to be used, and excellent effects such as polymerization stability and polymerization conversion ratio within the above-mentioned range can be obtained.

In the present invention, the oxidation-reduction catalyst may be at least one member selected from the group consisting of sodium pyrophosphate, dextrose, ferrous sulfate, sodium sulfite, sodium formaldehyde sulfoxylate and sodium ethylenediamine tetraacetate, Sodium laurate, dextrose, ferrous sulfate, and the like.

The oxidation-reduction catalyst may be used in an amount of 0.01 to 1 part by weight or 0.1 to 0.5 part by weight based on 100 parts by weight of the total amount of the monomers to be used. In this range, the efficiency of the initiator is increased to improve the reaction rate .

In a concrete example, the polymerization step of the present invention comprises the steps of: a-1) 50 to 70 parts by weight of a total of 100 parts by weight of a monomer to be used, 10 to 20 parts by weight of a vinyl cyan compound, 3 to 15 parts by weight of (meth) acrylic acid, 0.01 to 3 parts by weight of an emulsifier, 0.5 to 5 parts by weight of an emulsifier, 0.01 to 3 parts by weight of a molecular weight modifier, and 0.001 to 0.1 part by weight of an initiator; a-2) 0.05 to 0.5 part by weight of an initiator is added at a polymerization conversion rate of 25 to 45% in the first polymerization step, 10 to 40 parts by weight of polymerization water, 10 to 15 parts by weight of vinyl cyanide and 0.1 to 1 part by weight of an emulsifier And a second polymerization step of emulsion-polymerizing the mixture by continuously feeding the mixture liquid.

As described above, since the first polymerization step of batch-polymerizing a part of the monomers and the second polymerization step of reacting the remaining monomers in an emulsified state continuously are provided, the polymerization efficiency, conversion rate and the like are excellent.

The polymerization step of the present invention may be carried out, for example, at 50 to 90 ° C or at 50 to 80 ° C, and in particular the first polymerization step is carried out at 50 to 65 ° C and the second polymerization step is carried out at 70 to 90 Lt; 0 > C (higher than the temperature of the first polymerization step).

In the above temperature range, for example, the depolymerization of alpha-methylstyrene is inhibited, so that the reaction efficiency is excellent, the polymerization conversion rate is high, the unreacted monomer content is low, and the physical properties and appearance quality of the final injection molded product are excellent .

b) pH adjustment step

In the present invention, in order to improve the heat resistance property, the pH lowered by (meth) acrylic acid and the solubility in the polymerization water as the (meth) acrylic acid grows into a polymer are suppressed and the stability and reaction efficiency of the polymerized latex are suppressed And adjusting pH to a specific range by adding a pH adjusting agent during emulsion polymerization.

In the pH adjustment step of the present invention, the pH is adjusted to 2 to 7.5, 2 to 5 or 2.5 to 4.5 by the addition of a pH adjusting agent during the emulsion polymerization of the monomer. Within this range, polymerization stability is ensured, Can be achieved.

The pH adjusting agent may be added at a polymerization conversion rate of 30 to 90%, 50 to 90%, or 70 to 90%, for example. When the pH adjusting agent is added within the above range, It can be more effective in securing the stability of the latex, which is deteriorated.

The pH adjusting agent may be at least one selected from sodium hydroxide and potassium hydroxide, and the poly (meth) acrylic acid is converted into a poly (meth) acrylic acid sodium salt or a poly (meth) acrylic acid potassium salt by introducing it during emulsion polymerization There is an effect of improving the polymerization stability.

For example, the poly (meth) acrylic acid may be a polymethacrylic acid represented by the following formula (1), and may be converted into a polymethacrylic acid metal salt form as shown in formula (2) by the addition of a pH adjusting agent.

[Chemical Formula 1]

(2)

(Wherein M is sodium or potassium).

As described above, the poly (meth) acrylic acid is converted into the metal salt form by the addition of the pH controlling agent, and the polymerization stability is ensured, so that a high polymerization conversion rate can be achieved and ultimately, the heat resistance properties such as the glass transition temperature of the final resin are improved It is effective.

The pH adjusting agent is preferably added in an amount of 0.1 to 1.5 parts by weight, 0.2 to 1 part by weight or 0.5 to 0.9 part by weight based on 100 parts by weight of the total amount of the monomers, and the effect of stabilizing the polymerized latex within the above range is excellent have.

Wherein the pH controlling step comprises: 0.005 to 0.05 parts by weight or 0.005 to 0.025 parts by weight of initiator based on 100 parts by weight of the total of the monomers; And 0.0001 to 0.05 part by weight or 0.005 to 0.025 part by weight of an oxidation-reduction catalyst, and the polymerization rate is improved by further including the initiator and the oxidation-reduction catalyst within the above range, Polymerization conversion can be achieved, and ultimately, the effect of improving heat resistance such as the glass transition temperature of the resin can be obtained.

c) Polymerization termination step

In the present description, for example, it may be preferable to terminate the polymerization reaction at a polymerization conversion rate of more than 90%, 93 to 99.99%, 95 to 99.99%, or 96 to 99.99%, and within this range, the unreacted monomer content The physical properties and appearance characteristics of the resin are improved and the productivity is high.

The latex obtained after the termination step has an advantage of excellent productivity as the coagulated matter content is 0.9 wt% or less, 0.2 wt% or less, 0.1 wt% or less, or 0.05 wt% or less.

The coagulated matter content of the latex in the present invention can be calculated by the following equation (2).

&Quot; (2) "

Solidification water content (% by weight) = (weight of solidified product in the reaction tank / total monomer weight) X 100

The heat-resistant SAN resin manufacturing method of the present invention may further include a step of aggregating the latex obtained after the ending step and a step of obtaining a powder by dewatering and drying the aggregated slurry to obtain a resin powder.

d) Coagulation step

The flocculation step of the present invention may be carried out by flocculating 0.1 to 3 parts by weight, 1 to 3 parts by weight or 2 to 3 parts by weight of flocculant based on 100 parts by weight of the latex obtained after completion of the polymerization, (fine) content is small and the glass transition temperature of the final resin is high.

The agglomeration is preferably performed at 80 to 140 ° C or 90 to 120 ° C, and the agglomeration is high within the above range, so that the productivity of the resin powder is excellent.

The flocculant may include at least one member selected from the group consisting of magnesium sulfate, calcium chloride and aluminum sulfate, and preferably includes magnesium sulfate.

The poly (meth) acrylic acid metal salt represented by the formula (2) may be combined with the emulsifier added in the polymerization step to form a poly (meth) acrylic acid-emulsifier complex represented by the following formula .

(3)

Wherein M 'is at least one selected from the group consisting of magnesium, calcium and aluminum, X is at least one selected from -COO- or -SOO-, and R is selected from an alkyl group, an alkylbenzene group and an allyl group .)

The poly (meth) acrylic acid-emulsifier conjugate may be bonded to each other by divalent metal ions added at the time of aggregation to form a complex having a high glass transition temperature, thereby contributing to improvement of heat resistance of the final resin.

The agglomeration step may further include an aging step of aging the agglomerated slurry at a temperature of 80 to 140 ° C or 100 to 140 ° C. In this case, the productivity of the resin powder is further improved.

e) Step of obtaining resin powder

In the present invention, the step of obtaining a powder is a step of dehydrating and drying the coagulated slurry to obtain a powdery resin, and the resin powder obtained may have an average particle diameter of 150 to 500 mu m or 200 to 400 mu m, for example.

The resin powder may preferably have a fine particle content of not more than 20% by weight or not more than 15% by weight of fine particles having an average particle size of not more than 75 탆, and the heat resistance of the resin is more excellent within this range.

In the present description, the average particle diameter can be measured by a dynamic light skating method using a Nicomp 380 instrument.

The resin powder may have a weight average molecular weight of 90,000 to 230,000 g / mol or 150,000 to 215,000 g / mol. The resin powder has an excellent heat resistance property within this range.

In the present specification, the weight average molecular weight can be measured by a gel permeation chromatography method.

In addition, the resin powder may have a high heat resistance property at a glass transition temperature of 140 ° C or higher, 140-160 ° C, 144-160 ° C, 150-160 ° C or 155-160 ° C.

Other conditions and additives which are not explicitly described in explaining the heat-resistant SAN resin manufacturing method of the present invention are not particularly limited if they are within the range usually practiced in the technical field of the present invention, It is possible that

The heat-resistant SAN resin prepared according to the heat-resistant SAN resin manufacturing method of the present invention can be prepared from a resin composition by mixing with an ABS resin, and a method of manufacturing the heat-resistant SAN resin composition according to the present invention will be described below .

For example, the manufacturing method of the heat-resistant SAN resin composition may include a step of kneading and extruding 60 to 90% by weight of the heat-resistant SAN resin and 10 to 40% by weight of the ABS resin, and within this range, Properties, mechanical strength, and other physical properties.

As another example, the method for producing the heat-resistant SAN resin composition may include a step of kneading and extruding 70 to 80% by weight of the heat-resistant SAN resin and 20 to 30% by weight of the ABS resin. Within this range, Heat resistance, mechanical strength and other properties.

The method for producing a heat resistant SAN resin composition of the present invention may further comprise an aromatic vinyl compound-vinyl cyanide copolymer (not the same as a heat resistant SAN resin) to improve processing and molding characteristics. For example, A step of kneading and extruding 10 to 40% by weight of a base resin, 30 to 70% by weight of an aromatic vinyl compound-vinyl cyan compound copolymer and 10 to 40% by weight of an ABS resin, Properties, mechanical strength, processability, moldability, and the like.

As another example, a method of producing a heat-resistant SAN resin composition includes kneading and extruding 15 to 40 wt% of a heat-resistant SAN resin, 40 to 60 wt% of an aromatic vinyl compound-vinyl cyanide copolymer and 15 to 35 wt% of an ABS resin And has an advantage of being excellent in mechanical strength such as heat resistance and tensile strength such as thermal deformation temperature of the final product, processability and moldability within this range.

As another example, a method of producing a heat-resistant SAN resin composition includes kneading 20 to 35 wt% of heat-resistant SAN resin, 40 to 55 wt% of aromatic vinyl compound-vinyl cyanide copolymer and 20 to 30 wt% of ABS resin, And there is an effect of excellent processability, moldability and the like, while having excellent physical property balance of the final product within the above-mentioned range.

The kneading and extruding are not particularly limited and the composition can be uniformly dispersed by using a single screw extruder, a twin screw extruder, a Banbury mixer or the like, and the composition can be uniformly kneaded and then extruded into a pellet form .

The kneading and extruding may be carried out at a temperature of 240 to 270 DEG C and 150 to 400 rpm or 250 to 260 DEG C and 200 to 300 rpm, but is not limited thereto.

The heat-resistant SAN resin composition manufactured according to the present invention may be manufactured as an injection-molded article including an injection step, and the injection-molded article has a heat distortion temperature of 110 ° C or higher, 117 ° C or higher, 117 to 125 ° C or 120 excellent in heat resistance to 125 ℃, a tensile strength of example with 530kg / cm ² or more, 530 to 650 kg / cm ^2, 550 to 650 kg / cm ² or to the range of 600 to 650kg / cm ² to be characterized by excellent mechanical strength. .

The injection may be performed at a temperature of, for example, 240 to 270 DEG C and 40 to 120 bar, or 250 to 260 DEG C and 60 to 100 bar, but is not limited thereto.

The heat-resistant SAN-based resin manufacturing method of the present invention and other additives and process conditions which are not explicitly described in explaining the injection molded article can be appropriately selected within the range usually practiced in the technical field to which the present invention belongs, .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

[Example]

Example  One

MAA -AMS-AN resin manufacture

140 parts by weight of ion-exchanged water, 63 parts by weight of alpha-methylstyrene (AMS), 15 parts by weight of acrylonitrile (AN), 10 parts by weight of methacrylic acid (MAA) 0.15 part by weight of tertiary dodecylmercaptan (TDDM) as a molecular weight regulator, 0.05 part by weight of t-butyl hydroperoxide as an initiator, 0.025 part by weight of dextrose as an oxidation-reduction catalyst, 0.05 part by weight of sodium pyrrolephosphate And 0.0005 parts by weight of ferrous sulfate were added all at once and reacted at a reaction temperature of 50 캜 until a polymerization conversion rate of 30 to 40%.

Next, 0.1 part by weight of initiator t-butyl hydroperoxide, 0.05 part by weight of dextrose, 0.1 part by weight of sodium pyrrolephosphate, and 0.001 part by weight of ferrous sulfate were added in one portion, and then 25 parts by weight of ion exchanged water, 12 parts by weight of acrylonitrile , And 0.5 part by weight of sodium dibenzenesulfonate were continuously added to the mixture, and the mixture was heated to 80 캜 and allowed to react.

Subsequently, 0.5 part by weight of sodium hydroxide (NaOH) was added to adjust the pH while maintaining the temperature, and after 20 minutes, 0.01 part by weight of t-butyl hydroperoxide, 0.005 part by weight of dextrose, 0.01 part by weight of sodium pyrrolephosphate And 0.0001 part by weight of ferrous sulfate were added all at once and polymerized until the polymerization conversion rate reached 96%.

2.5 parts by weight of magnesium sulfate was added to 2500 parts by weight of ion exchange water using batch type flocculation equipment, and the stirrer was rotated at 300 rpm. After raising the temperature to 98 DEG C, 1000 parts by weight of latex was added at a constant flow rate to coagulate , The temperature was raised to 120 ° C, aged under a pressure of 2.1 kgf / cm ² , and the temperature was lowered to 50 ° C to recover the slurry.

The recovered slurry was dehydrated using a centrifugal dehydrator with a maximum number of rotations of 1,800 rpm and washed with 3000 parts by weight of ion exchange water. The resin in a wet powder state recovered after dewatering and washing was subjected to removal of moisture for 2 hours by using a fluid bed drier to obtain a resin powder.

The average particle size of the obtained resin powder was 252 탆, and the content of pine (particle size of 75 탆 or less) was confirmed to be 18% by weight.

Example  2 to 10

A resin powder was prepared in the same manner as in Example 1 except that the content and the conditions described in Table 1 were used.

Comparative Example  1 to 5

A resin powder was prepared in the same manner as in Example 1, except that the content and the conditions described in Table 2 were used.

Reference example  One

A resin powder was prepared in the same manner as in Example 1, except that the content and the conditions described in Table 2 were used.

[Test Example 1]

The properties of the resin latex and powder prepared in the above Examples, Comparative Examples and Reference Examples were measured by the following methods, and the results are shown in Tables 1 and 2 below.

1. Evaluation of latex stability: After transferring 300 g of latex to a 600 ml beaker, the latex was mixed at 12,000 rpm using a PRIMX homomixer and the stability was destroyed (the point at which the ampere value of the mixer changed) The time was measured.

2. Glass transition temperature (Tg) of resin powder: Measured using Pyris 6 DSC from Perkin Elmer.

3. Weight average molecular weight (Mw) of resin powder: 1 g of the resin was dissolved in THF and then measured by GPC.

Example Reference Example 1 One 2 3 4 5 6 7 8 9 10 AMS / AN
Weight portion 63/27 63/27 63/27 63/27 63/27 63/27 63/27 63/27 63/27 63/27 63/27 MAA
Weight portion 10 5 10 10 10 10 10 10 10 10 10 TDDM
Weight portion 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.9 0.9 0.45 NaOH
Weight portion 0.5 0.5 0.2 0.8 0.2 0.2 0.5 0.5 0.5 0.5 1.5 Adjusted pH 3.2 4.3 2.4 4.9 2.2 2.3 3.0 3.1 3.0 3.0 7.2 NaOH
Time of input (%) 90 90 90 90 30 60 30 60 60 90 90 Conversion Rate (%) 97.2 96.8 97.5 96.5 96.3 96.8 96.0 96.6 96.4 97.3 94.5 stability
(hr) 3 2.5 One 3.1 2.0 2.6 3.5 3.2 2.4 2.5 2.8 Tg (占 폚) 155.1 144.2 157.2 153.8 153.4 155.2 152.6 153.9 148.1 149.0 151.2 Mw
(g / mol) 209,
103 200,
427 210,
369 195,
552 173,
268 193,
651 171,
179 189,
960 108,
250 115,
169 186,251 Average particle diameter (占 퐉) 252 347 242 255 263 250 291 275 336 331 436 Fine content (% by weight) 18 10 19 18 16 17 15 16 11 11 9

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 AMS / AN weight portion 73/27 73/27 73/27 73/27 63/27 MAA weight part 0 0 0 0 10 TDDM weight part 0.45 0.45 0.45 0.9 0.45 NaOH weight part 0 0.2 0.5 0.5 0 PH at the point of application 8.2 8.1 10.5 10.4 1.8 NaOH input time (%) 90 60 90 90 90 Conversion Rate (%) 97.2 95.9 94.5 94.3 98 Stability (hr) 2 1.9 1.6 One 0.2 Tg (占 폚) 137.2 135.5 133.6 128.1 157.9 Mw (g / mol) 210,209 200,523 195,861 100,150 210,
638 Average particle diameter (占 퐉) 352 375 406 558 508 Fine content (% by weight) 15 13 11 8 7

As shown in Table 1, the heat-resistant SAN resin according to the present invention contains methacrylic acid upon polymerization and has a high polymerization conversion rate of 95% or more as the pH is controlled within a specific range, It has been confirmed that it has high stability compared to the example. In addition, it was confirmed that the glass transition temperature is excellent in heat resistance characteristics, which is 10 ° C or more higher than that of the comparative example.

Also, in Reference Example 1, it was confirmed that the polymerization conversion decreased to 95% or less as the pH adjusting agent was added in excess to increase the pH to 6 or more in the pH adjusting step, and it was not made as a specimen for measuring the physical properties.

Also, referring to Table 2, it was confirmed that the stability of latex was significantly low in Comparative Example 5 in which methacrylic acid was included in the polymerization of the SAN based resin but the addition of the pH controlling agent was omitted. This indicates that the methacrylic acid It can be judged that the solubility in ion exchange water as a reaction medium is lowered and the stability of the latex is lowered.

[Use Examples 1 to 11]

30 parts by weight of heat resistant SAN resin prepared according to Examples 1 to 10 and Comparative Examples 1 to 5, 25 parts by weight of ABS resin (DP271 manufactured by LG Chemical), 45 parts by weight of SAN pellets (100 UH manufactured by LG Chemical) And 1.5 parts by weight of a processing aid were mixed and mixed using a stirrer and extruded at 260 ° C. using a twin-screw extruder to prepare pellets (size 5 mm, weight 2 kg).

The resin composition prepared in the form of pellets was injected at a temperature of 260 DEG C and 100 bar using an LS injection machine to prepare specimens for measurement of physical properties.

[Test Example 2]

The physical properties of the specimens prepared in the above Examples were measured by the following methods, and the results are shown in Table 3 below.

1. Heat distortion temperature (℃)

Measured under a load of 18.6 kg using a heat distortion temperature measuring specimen of 1/4 "wide according to ASTM D648.

2. Tensile strength (kg / cm) ² )

According to ASTM D638, a specimen having a thickness of 1/4 "was pulled at a speed of 40 mm / min and tensile strength was measured.

3. Rockwell Hardness (RH)

The hardness at 60 kfg / cm < ² > under the condition of offset 1.0 standard was measured using a 1/2 "thick specimen according to ASTM D785, ISO 2039. (The measurement equipment was ask-F1000. )

Heat deformation temperature (캜) Tensile strength (kg / cm ² ) Rockwell hardness Use Example 1 (Example 1) 121.7 637 109.5 Use Example 2 (Example 2) 117.3 552 105.9 Use Example 3 (Example 3) 122.5 639 109.6 Use Example 4 (Example 4) 121.1 635 109.3 Use Example 5 (Example 5) 120.3 547 109.0 Use Example 6 (Example 6) 121.1 562 109.3 Use Example 7 (Example 7) 118.7 545 108.7 Use Example 8 (Example 8) 120.5 557 109.1 Use Example 9 (Example 9) 117.1 536 107.6 Use Example 10 (Example 10) 117.9 540 107.9 Use Example 11 (Comparative Example 1) 102.5 510 102.4 Use Example 12 (Comparative Example 2) 101.3 513 101.9 Use Example 13 (Comparative Example 3) 100.9 512 101.3 Use Example 14 (Comparative Example 4) 99.5 506 100.6 Use Example 15 (Comparative Example 5) 122.8 635 109.5

As shown in Table 3, the test pieces (Examples 1 to 10) including the heat-resistant SAN resin prepared according to the present invention had a heat distortion temperature of about 20 ° C or more And it was confirmed that the tensile strength was higher than 100 kg / cm ² and the hardness was more excellent.

Claims (20)

(a) 50 to 70 parts by weight of an aromatic vinyl compound, 20 to 35 parts by weight of a vinyl cyan compound and 3 to 15 parts by weight of (meth) acrylic acid based on 100 parts by weight of the total of monomers to be used; b) adjusting the pH to 2 to 7.5 by adding a pH adjusting agent during the emulsion polymerization; And c) terminating the polymerization reaction at the time when the polymerization conversion rate exceeds 90%.
A method for producing a heat-resistant SAN-based resin. The method according to claim 1,
Wherein the pH adjusting agent is at least one selected from the group consisting of sodium hydroxide and potassium hydroxide
A method for producing a heat-resistant SAN-based resin. The method according to claim 1,
Wherein the pH adjusting agent is added in an amount of 0.1 to 1.5 parts by weight based on 100 parts by weight of the total amount of the monomers.
A method for producing a heat-resistant SAN-based resin. The method according to claim 1,
Wherein the pH adjusting agent is added at a time when the polymerization conversion of the emulsion polymerization is 30 to 90%
A method for producing a heat-resistant SAN-based resin. The method according to claim 1,
Characterized in that a) the polymerization step is carried out at from 50 to 90 < RTI ID = 0.0 >
A method for producing a heat-resistant SAN-based resin. The method according to claim 1,
And b) the pH control step further comprises 0.005 to 0.05 part by weight of the initiator based on 100 parts by weight of the total amount of the monomers and 0.0001 to 0.05 part by weight of the oxidation-reduction catalyst.
A method for producing a heat-resistant SAN-based resin. The method according to claim 1,
Characterized in that the latex obtained after the c) termination step has a coagulation content of 0.9% by weight or less
A method for producing a heat-resistant SAN-based resin. The method according to claim 1,
(C) after the completion of the step (d), 0.1 to 3 parts by weight of a flocculant is added based on 100 parts by weight of the obtained latex to coagulate the flocculant. 9. The method of claim 8,
And d) the agglomeration step is carried out at 80 to 140 ° C.
A method for producing a heat-resistant SAN-based resin. 9. The method of claim 8,
Wherein the flocculant is at least one selected from magnesium sulfate, calcium chloride and aluminum sulfate.
A method for producing a heat-resistant SAN-based resin. 9. The method of claim 8,
And d) after the aggregation step, e) dehydrating and agglomerating the agglomerated slurry to obtain a resin powder.
A method for producing a heat-resistant SAN-based resin. 12. The method of claim 11,
Wherein the resin powder has an average particle diameter of 150 to 500 mu m
A method for producing a heat-resistant SAN-based resin. 12. The method of claim 11,
Wherein the resin powder has a fine content of not more than 20% by weight of an average particle size of 75 탆 or less
A method for producing a heat-resistant SAN-based resin. 12. The method of claim 11,
Wherein the resin powder has a glass transition temperature of 140 ° C or higher
A method for producing a heat-resistant SAN-based resin. The method according to claim 1,
(A) 1) a total of 100 parts by weight of a monomer to be used, 50 to 70 parts by weight of a reference aromatic vinyl compound, 10 to 20 parts by weight of a vinyl cyan compound, 3 to 15 parts by weight of (meth) acrylic acid, To 180 parts by weight of an emulsifier, 0.5 to 5 parts by weight of an emulsifier, 0.01 to 3 parts by weight of a molecular weight modifier, and 0.001 to 0.1 part by weight of an initiator; a-2) 0.05 to 0.5 part by weight of an initiator is added at a polymerization conversion rate of 25 to 45% in the first polymerization step, 10 to 40 parts by weight of polymerization water, 10 to 15 parts by weight of vinyl cyanide and 0.1 to 1 part by weight of an emulsifier And a second polymerization step of emulsion-polymerizing the mixture by continuously feeding the mixture liquid containing
A method for producing a heat-resistant SAN-based resin. 16. The method of claim 15,
Wherein the weight ratio of the polymerized water and the (meth) acrylic acid is in the range of 6: 1 to 60: 1
A method for producing a heat-resistant SAN-based resin. A method of kneading 10 to 40% by weight of a heat-resistant SAN resin, 30 to 70% by weight of an aromatic vinyl compound-vinyl cyan compound copolymer and 10 to 40% by weight of an ABS resin according to the production method of any one of claims 1 to 16 And a step of extruding
A method for producing a heat-resistant SAN-based resin composition. A method for producing a heat-resistant SAN resin composition, comprising the steps of: injecting a heat-resistant SAN resin composition produced according to claim 17
A method of manufacturing an injection molded article. 19. The method of claim 18,
Wherein the injection-molded article has a heat distortion temperature of 110 ° C or higher
A method of manufacturing an injection molded article. 19. The method of claim 18,
Wherein the injection-molded article has a tensile strength of 530 kg / cm ² or more
A method of manufacturing an injection molded article.