WO2016105171A1 - Method for preparing diene-based rubber latex and acrylonitrile-butadiene-styrene graft copolymer comprising same - Google Patents

Abstract

The present invention relates to a method for preparing a large-diameter diene-based rubber latex and an acrylonitrile-butadiene-styrene graft copolymer comprising the same. The present invention relates to: a method for preparing a large-diameter diene-based rubber latex with improved impact strength by adjusting, during the preparation of the large-diameter rubber latex, the content and input timing of a cross-linking agent and an emulsifier which has a critical micelle concentration (CMC) of 150 mg/L or less; a large-diameter diene-based rubber latex prepared therefrom; an acrylonitrile-butadiene-styrene graft copolymer comprising the same; and a thermoplastic resin comprising the same.

Description

Method for preparing diene rubber latex and acrylonitrile-butadiene-styrene graft copolymer comprising same

Cross Citation with Related Application (s)

This application claims the benefit of priority based on Korean Patent Application No. 10-2014-0187763 of December 24, 2014 and Korean Patent Application No. 10-2015-0186080 of December 24, 2015. All content disclosed in the literature is included as part of this specification.

Technical Field

The present invention relates to a large diameter diene-based rubber latex production method and an acrylonitrile-butadiene-styrene graft copolymer comprising the same, the crosslinking agent and critical micelle concentration (CMC) in the production of large diameter rubber latex (150) Method for producing a large diameter diene rubber latex with improved impact strength by controlling the content and the timing of the emulsifier of mg / L or less, and the large diameter diene rubber latex prepared therefrom and acrylonitrile-butadiene-styrene It relates to a graft copolymer.

In general, thermoplastic resins have relatively good physical properties such as impact resistance, mechanical strength, moldability, glossiness, etc., and thus are widely used in electrical, electronic parts, office equipment, automobile parts, and the like.

Representative ABS (Acrylonitrile-Butadiene-Styrene, ABS) resin as the thermoplastic resin is an impact modifier, and includes a conjugated diene-based rubber latex represented by polybutadiene having excellent rubber properties as a main component.

The conjugated diene rubber latex may be prepared by emulsion polymerization. Emulsion polymerization is easy to modify the prescription according to the quality level required at the same time, and various matrix resins (PSAN, PC, PBT, PVC, etc.) and additives through the extrusion process using the product produced in the form of powder ( Flame retardant, weathering stabilizer, antistatic agent, antibacterial agent, etc.) and has the advantage of manufacturing a variety of products.

On the other hand, the particle size of the conjugated diene-based rubber latex is closely related to the emulsion polymerization reaction time. For example, in order to manufacture a large-diameter rubber latex having a large particle size, an emulsion polymerization reaction should be performed for 30 hours or more. Therefore, the conventional large-diameter rubber latex manufacturing method has a disadvantage of low productivity.

In order to improve this problem, a method of adding a small amount of an additive such as an emulsifier and a vinyl cyanide monomer, or continuously adding the emulsifier before the start of polymerization has been proposed. However, there is a problem that the effect of shortening the reaction time is insufficient. If the polymerization temperature is increased in order to increase the reaction rate, the rubber latex may have a smaller particle diameter and a larger amount of coagulum, and further increase safety due to an increase in reaction pressure due to excessive reaction heat. Problems arise.

Furthermore, in the production of the thermoplastic resin, when mixing the large diameter rubber latex and the small diameter rubber latex produced by the conventional method, a thermoplastic resin having a relatively high low temperature impact strength and a relatively high surface gloss can be produced. Since the large-diameter rubber latex and the hydrophobic rubber latex are separately prepared and then mixed, the process time is long, the process is complicated, and the cost increases.

Therefore, it is urgent to develop a method for producing a diene rubber latex having a controlled particle size in a short reaction time.

The present invention has been made to solve the problems of the prior art, by adjusting the content and the timing of the addition of the emulsifier having a crosslinking agent and critical micelle concentration (CMC) of 150 mg / L or less, large diameter rubber latex and small An object of the present invention is to provide a method for producing a diene rubber latex having a controlled content ratio of rubber latex.

Another object of the present invention is to provide a diene rubber latex prepared from the above method.

Still another object of the present invention is to provide an acrylonitrile-butadiene-styrene graft copolymer and a thermoplastic resin having improved impact strength, glossiness, and low temperature impact strength by including the diene rubber latex.

In order to solve the above problems, in one embodiment of the present invention

60 to 75 parts by weight of the conjugated diene monomer, 1 to 3 parts by weight of the first emulsifier, 0.2 to 0.4 parts by weight of the polymerization initiator, 0.2 to 3 parts by weight of the electrolyte, 0.1 to 0.5 parts by weight of the molecular weight regulator 65 parts by weight and 100 parts by weight of ion-exchanged water in a reactor and polymerization;

2 steps of collectively adding 10 to 20 parts by weight of the conjugated diene monomer, and 0.1 to 1.0 parts by weight of the second emulsifier at a time when the polymerization conversion rate of the polymerization reaction is 30% to 40%;

3 steps of polymerizing a batch or continuous addition of a residual amount of the conjugated diene monomer and 0 parts by weight to 1 part by weight of the third emulsifier optionally at a polymerization conversion rate of 60% to 70%; And

In the manufacturing method of the diene-based rubber latex comprising; 4 steps of terminating the polymerization by adding a polymerization inhibitor when the polymerization conversion rate of the polymerization reaction is 92% or more,

Diene-based rubber latex comprising the step of additionally adding 0.05 to 0.3 parts by weight of the crosslinking agent at a polymerization conversion rate of 0 to 50% of the polymerization reaction proceeding through the first and second steps It provides a manufacturing method.

In addition, the method adds 0.01 parts by weight to 0.5 parts by weight of a fourth emulsifier having a critical micelle concentration (CMC) of 150 mg / L or less at a polymerization conversion rate of 50% to 85% of the polymerization reaction proceeding through steps 1 and 2. It may further comprise the step of inputting.

In this case, the crosslinking agent may include an acrylate-based crosslinking agent,

The fourth emulsifier may include an emulsifier of CMC 10 mg / L or less or an emulsifier of CMC 10 mg / L to 150 mg / L.

In addition, in one embodiment of the present invention

As a diene rubber latex prepared from the manufacturing method,

The diene rubber latex includes a large diameter diene rubber latex having an average particle diameter of 2,600 mm to 5,000 mm and a small diameter diene rubber latex having an average particle diameter of 20 to 70 nm. The mixing ratio of the latexes provides a diene-based rubber latex of 98% to 99.9% by weight: 0.01% to 2% by weight.

The present invention also provides an acrylonitrile-butadiene-styrene graft copolymer comprising the diene rubber latex.

The present invention also provides a thermoplastic resin comprising the acrylonitrile-butadiene-styrene graft copolymer.

In the method for producing a diene rubber latex according to the present invention, a crosslinking agent is added at a polymerization conversion rate of 0 to 50%, and a critical micelle concentration (CMC) is 150 mg / C at a polymerization conversion rate of 50% to 85%. By carrying out a polymerization reaction in which an emulsifier of less than or equal to L is added, a diene rubber latex including both large-diameter rubber latex and small-diameter rubber latex can be produced.

In addition, by including this, it is possible to secure the surface gloss and low temperature impact strength of the acrylonitrile-butadiene-styrene graft copolymer and the thermoplastic resin.

Accordingly, the process for producing the diene-based rubber latex according to the present invention and the acrylonitrile-butadiene-styrene graft copolymer and the thermoplastic resin comprising the diene-based rubber latex produced therefrom are industries in need thereof, in particular the impact modifier industry. It can be easily applied to.

Hereinafter, the present invention will be described in more detail to aid in understanding the present invention.

The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

In one embodiment of the present invention

60 to 75 parts by weight of the conjugated diene monomer, 1 to 3 parts by weight of the first emulsifier, 0.2 to 0.4 parts by weight of the polymerization initiator, 0.2 to 3 parts by weight of the electrolyte, 0.1 to 0.5 parts by weight of the molecular weight regulator 65 parts by weight and 100 parts by weight of ion-exchanged water in a reactor and polymerization;

2 steps of collectively adding 10 to 20 parts by weight of the conjugated diene monomer, and 0.1 to 1.0 parts by weight of the second emulsifier at a time when the polymerization conversion rate of the polymerization reaction is 30% to 40%;

3 steps of polymerizing a batch or continuous addition of a residual amount of the conjugated diene monomer and 0 parts by weight to 1 part by weight of the third emulsifier optionally at a polymerization conversion rate of 60% to 70%; And

In the manufacturing method of the diene-based rubber latex comprising; 4 steps of terminating the polymerization by adding a polymerization inhibitor when the polymerization conversion rate of the polymerization reaction is 92% or more,

It provides a method for producing a diene rubber latex comprising the step of additionally adding 0.05 parts by weight to 0.3 parts by weight of the crosslinking agent at a time point of 0 to 50% of the polymerization conversion of the polymerization reaction proceeding through the steps 1 and 2.

In addition, the method adds 0.01 parts by weight to 0.5 parts by weight of a fourth emulsifier having a critical micelle concentration (CMC) of 150 mg / L or less at a polymerization conversion rate of 50% to 85% of the polymerization reaction proceeding through steps 1 and 2. It provides a method for producing a diene rubber latex further comprising the step of injecting.

In the first step of the polymerization, in order to start the polymerization by mixing the conjugated diene monomer with the first emulsifier and the molecular weight modifier, 60 parts by weight to 75 parts by weight of the conjugated diene monomer, 1 part by weight to 3 parts by weight of an emulsifier, and a polymerization initiator 0.2 Part by weight to 0.4 parts by weight, electrolyte 0.2 parts by weight to 3 parts by weight, 0.1 parts by weight to 0.5 parts by weight of the molecular weight regulator and 65 parts by weight to 100 parts by weight of ion-exchanged water to the reactor.

In the present invention, the conjugated diene monomer may include a single conjugated diene monomer or a monomer mixture including the conjugated diene monomer as a main component.

In this case, the monomer mixture is 55 to 99.7% by weight of the conjugated diene monomer; 0.1 wt% to 40 wt% of an aromatic vinyl monomer; And vinyl cyanide monomers in an amount of 0.1 wt% to 40 wt%.

The conjugated diene monomer is not particularly limited, but may be, for example, at least one selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, and piperylene. Specifically, it may be 1,3-butadiene.

The aromatic vinyl monomer is not particularly limited, but may be, for example, one or more selected from the group consisting of styrene, α-methyl styrene, α-ethyl styrene, and p-methyl styrene. Specifically, it may be styrene.

The vinyl cyan monomer is not particularly limited, but may be, for example, one or more selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile. Specifically, it may be acrylonitrile.

The polymerization initiator is not particularly limited and may be a conventional one known in the art, but for example, a water-soluble polymerization initiator such as persulfate, a fat-soluble polymerization initiator such as a peroxy compound, or an oxidation-reduction catalyst may be used.

The persulfate may be potassium persulfate, sodium persulfate, ammonium persulfate, and the like, and the fat-soluble polymerization initiator is cumene hydroperoxide, diisopropyl benzene hydroperoxide, azobis isobutylonitrile, tertiary butyl hydroperoxide , Paramentane hydroperoxide, benzoyl peroxide, and the like. In addition, the redox-based catalyst may be sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, dextrose, sodium pyrrolate, sodium sulfite and the like.

The electrolyte is potassium chloride, sodium chloride, potassium bicarbonate, sodium bicarbonate, potassium carbonate, sodium carbonate, potassium sulfate, sodium sulfate, potassium hydrogen sulfite, sodium hydrogen sulfite, potassium pyrophosphate, sodium pyrophosphate, potassium phosphate, sodium phosphate, potassium hydrogen phosphate, phosphoric acid Sodium hydrogen and the like.

The molecular weight modifier is not particularly limited, but for example, mercaptans such as a-methylstyrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, octyl mercaptan, halogenated hydrocarbons such as carbon tetrachloride, methylene chloride and methylene bromide Sulfur-containing compounds such as tetraethyl thiuram disulfide, dipentamethylene thiuram disulfide, diisopropylchianthogen disulfide. Preferably t-dodecyl mercaptan.

In addition, the second step of the polymerization is a step of collectively adding 10 parts by weight to 20 parts by weight of the conjugated diene monomer and 0.1 parts by weight to 1.0 parts by weight of the second emulsifier at the time when the polymerization conversion rate of the first polymerization is 30% to 40%. .

In the polymerization step 3, the polymerization conversion rate of the first polymerization is a step of continuously or continuously adding the residual amount of the conjugated diene monomer and 0 parts by weight to 1 part by weight of the third emulsifier.

In this case, the first to third emulsifiers are independently allyl aryl sulfonate, alkali methyl alkyl sulfate, sulfonated alkyl ester, fatty acid soap, alkali rosin acid salt, sodium lauryl sulfonate, potassium oleate, sodium alkylbenzene sulfonates, polyoxyethylene alkyl phenyl ether (polyoxyethylene alkylphenyl ether), sodium dodecyl allyl sulfosuccinate, C _16-18 alkenyl succinic acid di-potassium salt (C _16-18 alkenyl succinic acid, di-potassium salt), Sodium acrylamide stearate, polyoxyethylene alkylphenyl ether ammonium sulfate, polyoxyethylene alkyl ether ester ammonium salt, and the like can be used alone or in combination, without being particularly limited.

As described above, the production method according to the present invention can easily form a diene rubber latex having an appropriate particle size by dividing the conjugated diene monomer into three stages (batch addition and continuous addition) according to the polymerization conversion time point. have.

Steps 1 to 3 of the polymerization according to the present invention may be performed at different temperature ranges, respectively.

Specifically, the first step may be carried out in a temperature range of 65 ℃ to 70 ℃, the second step may be carried out in a temperature range of 72 ℃ to 75 ℃, the third step is a temperature of 80 ℃ to 85 ℃ It can carry out in a range. That is, according to the present invention, the polymerization may be carried out while gradually increasing the polymerization temperature as the polymerization proceeds.

In particular, the method of the present invention may include the step of additionally adding 0.05 to 0.3 parts by weight of the crosslinking agent at the time of 0% to 50% of the polymerization conversion rate of the primary polymerization reaction.

At this time, the cross-linking agent may include (alkylene glycol) _n diacrylate or (alkylene glycol) _n triacrylate (where n is an integer of 3 to 15). In this case, when n is greater than 15, impact strength is improved, but rubber latex stability is deteriorated. In addition, when the content of the crosslinking agent is less than 0.05 parts by weight, the impact strength increase effect is insignificant or hardly occurs, and when the content of the crosslinking agent exceeds 0.3 parts by weight, rubber latex stability is deteriorated.

Specifically, the crosslinking agent may include (ethylene glycol) ₈ diacrylate, (ethylene glycol) ₁₂ diacrylate, (propylene glycol) ₈ diacrylate, or (propylene glycol) ₁₂ diacrylate.

In particular, in the present invention, the effect of increasing the polymerization rate can be obtained by adding the acrylate crosslinking agent at the initial stage of the polymerization reaction and reacting.

In addition, the method of the present invention is a fourth emulsifier having a critical micelle concentration (CMC) of 150 mg / L or less at a polymerization conversion rate of 50% to 85% of the polymerization reaction proceeds through the steps 1 and 2 It may include the step of additionally 0.01 to 0.5 parts by weight.

Specifically, the fourth emulsifier may include an emulsifier of CMC 10 mg / L or less or CMC 10 to 150 mg / L emulsifier.

More specifically, when the emulsifier of 10 mg / L or less of the CMC, 0.01 parts by weight of the emulsifier of 10 mg / L or less of the CMC at 60 to 85% of the polymerization conversion rate of the polymerization reaction proceeds through the first and second steps To 0.3 part by weight may be added. At this time, the emulsifier of less than 10 mg / L of CMC is a typical example of C _16-18 alkenyl succinic acid di- potassium salt, poly-oxyethylene alkylphenyl ether, polyoxyethylene alkylphenyl ether ammonium salt ), And the like.

In addition, when the fourth emulsifier includes a CMC 10 to 150 mg / L emulsifier, the CMC is 10 to 150 mg at a polymerization conversion rate of 50 to 85% of the polymerization reaction proceeds through the first and second steps 0.05 part by weight to 0.5 part by weight of an emulsifier of / L may be added. At this time, the emulsifier of the CMC 10 to 150 mg / L may be a representative example, such as fatty acid soap or potassium oleate, and among these, potassium oleate.

All of the first to fourth emulsifiers may be the same, or may be different from each other independently. For example, when both the first emulsifier and the fourth emulsifier include potassium oleate, potassium oleate, which is a first emulsifier added at the beginning of the reaction, is added together with an electrolyte to form initial micelles or particles, and during the reaction. The role of the fourth emulsifier is different from that of the latex rubber particles which are added and initially grown to produce small-diameter rubber latex particles.

That is, according to the method of the present invention, a fourth emulsifier is added during the polymerization reaction so that a small diameter rubber latex is produced at the same time as a large diameter rubber latex, thereby maintaining a high surface glossiness while maintaining an equivalent or more in terms of impact strength. It is possible to produce a thermoplastic resin capable of ensuring a low low-temperature impact strength reduction range.

On the other hand, the fourth emulsifier can be added to about 0.01 parts by weight to 0.5 parts by weight, if the content of the fourth emulsifier exceeds 0.5 parts by weight during the entire polymerization reaction to ensure a low temperature impact strength reduction range and high gloss However, the small-diameter generation rate is increased, the average particle diameter size is reduced, the impact strength is reduced compared to the existing ones, and the physical properties are lowered, and the viscosity is increased during the polymerization process, resulting in a decrease in the stability of the reaction. . In addition, if the input content is less than 0.01 parts by weight, the ratio of the resulting small diameter becomes insignificant, or there is a disadvantage that the expression of the effect is difficult to be used to stabilize the existing particle size.

In addition, when the fourth emulsifier is added when the conversion rate at the time of addition is low, for example, when the fourth emulsifier is added at a polymerization conversion rate of 50% or less, the small-diameter rubber latex formation rate is increased, resulting in high glossiness and low low temperature impact strength reduction. It's hard to expect. In addition, when the fourth emulsifier is added when the conversion rate at the time of addition is high, for example, when the fourth emulsifier is added at a polymerization conversion rate of 80% or more, the monomer content not participating in the reaction has a low tendency to show a similar tendency to less emulsifier There is this.

On the other hand, when the fourth emulsifier contains an emulsifier having a high CMC, for example, 150 mg / L or more, it is not easy to simultaneously prepare large-diameter rubber latex and small-diameter rubber latex.

The end of the polymerization step is a step of terminating the polymerization when the polymerization conversion rate is 92% or more in order to obtain a diene rubber latex.

Termination of the polymerization may be carried out using a polymerization inhibitor, the polymerization inhibitor may be used a conventional one known in the art.

The present invention also provides a diene rubber latex prepared from the above production method.

At this time, the diene rubber latex according to an embodiment of the present invention includes a large diameter diene rubber latex having an average particle diameter of 2,600 mm to 5,000 mm and a small diameter diene rubber latex having an average particle diameter of 20 nm to 70 nm, The mixing ratio of the large-diameter rubber latex: small-diameter rubber latex provides a diene-based rubber latex of 98% by weight to 99.9% by weight: 0.01% by weight to 2% by weight.

Here, Å represents a unit of the length used to express the wavelength of electromagnetic radiation, where 1 같다 is equal to 0.1 nm.

In addition, the diene rubber latex may be a gel content of 70% to 84%, the swelling index may be 11 to 25.

In this case, the gel content indicates the degree of crosslinking in the polymer, that is, the degree of crosslinking of the polymer, and the greater the gel content value, the higher the degree of crosslinking of the polymer.

The swelling index indicates the degree of swelling of the polymer by the solvent. The higher the crosslinking degree of the polymer, the lower the swelling index.

As described above, in the method of the present invention, 0.05 to 0.3 parts by weight of the crosslinking agent is additionally added at a time point of 0 to 50% of the polymerization conversion progressed through steps 1 and 2, and the polymerization reaction is performed with an emulsifier having a CMC of 150 mg / L or less. When the polymerization conversion rate of 50% to 85% of about 0.01 parts by weight to 0.5 parts by weight, a change in physical properties can be brought about in the thermoplastic resin. That is, large-diameter rubber latex and small-diameter rubber latex can be produced at the same time, it is possible to suppress the increase of the gel content and decrease of the swelling index while increasing the polymerization conversion rate. As a result, it is possible to produce a thermoplastic resin having improved low temperature impact strength and surface gloss while maintaining the existing impact strength. On the other hand, small-diameter latex can be observed on the rubber latex in TEM analysis photos or particle size measurement equipment, but does not show a difference in the average particle size.

In addition, the present invention provides an acrylonitrile-butadiene-styrene copolymer including the diene rubber latex.

Acrylonitrile-butadiene-styrene copolymer according to an embodiment of the present invention

40 wt% to 70 wt% of the diene rubber latex,

20 wt% to 50 wt% of an aromatic vinyl compound, and

It is characterized in that it comprises 10 to 40% by weight of the vinyl cyan compound.

Specifically, the acrylonitrile-butadiene-styrene copolymer may have a graft rate of 2% 5 to 35%, and a product coagulant content of 0.01% to 0.1%, and more specifically, a graft rate of 33% and 0.05% May have a product coagulant content.

On the other hand, the acrylonitrile-butadiene-styrene copolymer according to the present invention is not particularly limited and can be prepared by conventional methods known in the art, such as aromatic vinyl compound, vinyl cyan compound and It may be prepared by adding an additive such as an emulsifier and then emulsion polymerization and coagulation and washing. At this time, each component may be involved in the reaction through a method of adding to the reactor in a batch, a method of adding continuously or a part of the first addition and the divided input after the start of the polymerization.

In addition, in order to facilitate the emulsion polymerization, additives such as chelating agent, dispersing agent, pH adjusting agent, deoxygenating agent, particle size adjusting agent, anti-aging agent, oxygen scavenger may be further used as necessary. Emulsification polymerization may be carried out typically in a temperature range of 10 ℃ to 90 ℃, preferably a temperature range of 25 ℃ to 75 ℃.

In addition, the agglomeration is to agglomerate the acrylonitrile-butadiene-styrene copolymer latex composition formed after the emulsion polymerization to form an acrylonitrile-butadiene-styrene copolymer latex coagulum, in a conventional method known in the art. It can be carried out by, for example, the composition can be carried out by treating the salt aqueous solution or acid aqueous solution and salt agglomeration or acid agglomeration.

The washing is to remove the impurities (residual emulsifier, flocculant, etc.) from the acrylonitrile-butadiene-styrene copolymer latex coagulum formed through the salt agglomeration or acid agglomeration to obtain an acrylonitrile-butadiene-styrene copolymer. , The coagulum may be added to an aqueous inorganic salt solution, washed, and dried.

At this time, the washing and drying is not particularly limited and may be carried out by a method conventional in the art.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are provided to illustrate the present invention, and the scope of the present invention is not limited only to these examples.

Example

(Example 1)

1) Preparation of diene rubber latex

In a nitrogen-substituted polymerization reactor (autoclave), 65 parts by weight of ion-exchanged water, 70 parts by weight of 1,3-butadiene, 1.5 parts by weight of potassium rosin salt as the first emulsifier, 0.8 parts by weight of potassium oleate salt, potassium carbonate as an electrolyte ( K ₂ CO ₃ ) 0.8 parts by weight, 0.3 parts by weight of tertiary dodecylmercaptan (TDDM) as the molecular weight regulator, 0.3 parts by weight of potassium persulfate (K ₂ S ₂ O ₈ ) as the polymerization initiator and polymerization conversion rate at 70 ℃ 30 After the reaction to% (step 1), 20 parts by weight of 1,3-butadiene was collectively administered, 0.3 parts by weight of potassium rosin salt was added as a second emulsifier, and the reaction was carried out at 75 ° C. to 60% of the polymerization conversion rate (step 2). ). At this time, as shown in Table 1 below, 0.1 parts by weight of a crosslinking agent ((propylene glycol) ₈ diacrylate) was added at the beginning of the polymerization reaction, and potassium oleate having 35 mg / L as the fourth emulsifier was added at a polymerization conversion rate of 60%. Further 0.35 parts by weight was added to participate in the reaction, 15 parts by weight of the remaining 1,3-butadiene was collectively administered, and the reaction was carried out by raising the temperature to 82 ° C (third step). When the polymerization conversion rate of the polymerization reaction was 95% or more, a polymerization inhibitor was added to terminate the polymerization to obtain a diene rubber latex.

2) Preparation of Acrylonitrile-Butadiene-Styrene Copolymer

65 parts by weight of the diene rubber latex prepared in 1) and 100 parts by weight of ion-exchanged water were added to a nitrogen-substituted polymerization reactor, and 10 parts by weight of acrylonitrile, 25 parts by weight of styrene and ion exchanged in a separate mixing device. 20 parts by weight of water, 0.1 parts by weight of t-butyl hydroperoxide, 1.0 part by weight of potassium rosinate, and 0.3 part by weight of tertiary dodecyl mercaptan, 0.054 part by weight of dextrose, 0.004 part by weight of pyrroline sulfate and sulfuric acid 0.002 parts by weight of ferrous iron were continuously added together to the polymerization reactor at 70 ° C. for 3 hours. After the continuous feeding, 0.05 parts by weight of dextrose, 0.03 parts by weight of sodium pyrolate, 0.001 parts by weight of ferrous sulfate, and 0.005 parts by weight of t-butyl hydroperoxide were collectively added to the polymerization reactor and the temperature was raised to 80 ° C. After the temperature was raised over 1 hour, the reaction was terminated. The formed acrylonitrile-butadiene-styrene copolymer latex was coagulated with an aqueous sulfuric acid solution, washed and dried to obtain a powdered acrylonitrile-butadiene-styrene copolymer.

3) Acrylonitrile-butadiene-styrene thermoplastic

After mixing 26% by weight of the acrylonitrile-butadiene-styrene graft copolymer powder and 74% by weight of styrene-acrylonitrile resin (LG SAN 92 HR)), it was pelletized using an extruder and then injected. The test piece of acrylonitrile- butadiene- styrene thermoplastic resin was obtained using the molding machine.

(Example 2)

0.2 weight part of ((propylene glycol) ₈ diacrylate) was used as a crosslinking agent in the preparation of diene rubber latex, and 35 mg / L of potassium oleate was injected into the fourth emulsifier at 58% of the polymerization conversion rate. A diene rubber latex was prepared in the same manner as in Example 1. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Example 3)

Example 1 except that ₁₂ diacrylate (propylene glycol) was added as a crosslinking agent and 35 mg / L of potassium oleate, the fourth emulsifier, was added at a polymerization conversion rate of 62%. The diene rubber latex was prepared by the same method. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Example 4)

In the production of diene rubber latex, (diethylene glycol) ₁₂ diacrylate, which is a crosslinking agent, was added at a polymerization conversion rate of 20% and 35 mg / L potassium oleate at a polymerization conversion rate of 58% was used as a fourth emulsifier. Except for producing a diene rubber latex through the same method as in Example 1. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Example 5)

Diene fourth emulsifier CMC 4.8mg / L of ₁₆ C at the time of manufacturing the rubber latex - and, through the same procedure as in Example 1, except that the added potassium salt (Latemul ASK) 0.05 parts by weight - ₁₈ alkenyl succinic acid di Diene rubber latex was prepared. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Comparative Example 1)

A diene-based rubber latex was prepared in the same manner as in Example 1, except that a crosslinking agent and a fourth emulsifier were not additionally added during the preparation of the diene-based rubber latex. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Comparative Example 2)

A diene rubber latex was prepared in the same manner as in Example 1, except that 0.35 parts by weight of potassium oleate, 35 mg / L, was added as a fourth emulsifier when the diene rubber latex was prepared. It was. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Comparative Example 3)

0.5 parts by weight of (propylene glycol) ₁₂ diacrylate), a crosslinking agent, was added at the beginning of the reaction when the diene rubber latex was prepared, and 0.35 parts by weight of potassium oleate as a fourth emulsifier was added at a polymerization conversion rate of 59%. A diene rubber latex was prepared in the same manner as in Example 1. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Comparative Example 4)

In preparing diene rubber latex, 0.2 parts by weight of ₁₂ diacrylate (propylene glycol) was added as a crosslinking agent at a polymerization conversion time of 60%, and 0.35 parts by weight of potassium oleate as a fourth emulsifier was added at a time of 59% polymerization conversion. Then, a diene rubber latex was prepared in the same manner as in Example 1. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Comparative Example 5)

A diene rubber latex was prepared in the same manner as in Example 3, except that 0.75 parts by weight of potassium oleate, 35 mg / L, was used as a fourth emulsifier in preparing the diene rubber latex. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

(Comparative Example 6)

A diene rubber latex was prepared in the same manner as in Example 3, except that the fourth emulsifier was added at a polymerization conversion rate of 45% when the diene rubber latex was prepared. In addition, acrylonitrile-butadiene-styrene copolymer and thermoplastic resin specimens including the same were obtained.

Experimental Example

 Physical properties such as low temperature impact strength and glossiness of each specimen prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were measured, and the results are shown in Table 1 below.

1) Conversion rate (%): The conversion rate of each diene rubber latex prepared in Examples 1 to 4 and Comparative Examples 1 to 4 was measured.

2) Impact Strength: Each specimen was prepared 1/4 inch thick and measured according to ASTM D256.

3) Low temperature impact strength: The specimen subjected to the extrusion was measured in accordance with ASTM D256 after standing in a low temperature chamber at -20 ℃ for 2 hours.

4) Glossiness: Glossiness was measured at 45 degree angle with Gloss meter according to ASTM D-528. In this case, the greater the gloss value, the better the gloss.

As shown in Table 1, according to the method of the present invention, the crosslinking agent was added at a polymerization conversion rate of 0% to 20%, and the fourth emulsifier was added at a polymerization conversion rate of 50% to 80%. In the case of the resin specimen, it can be seen that the polymerization stability, impact strength, glossiness, and low temperature impact strength were all improved compared to the thermoplastic resin specimen of Comparative Example 1 in which the crosslinking agent and the fourth emulsifier were not added.

On the other hand, in the case of the thermoplastic resin specimens of Comparative Example 2 containing no crosslinking agent and having a fourth emulsifier at a polymerization conversion rate of 62%, the glossiness and low temperature impact strength of the thermoplastic resin specimens of Examples 1 to 5 improved the impact strength. However, it was confirmed that the impact strength was low. In addition, the thermoplastic resin specimen of Comparative Example 3 in which the crosslinking agent was added in excess, the impact strength was higher than that of the thermoplastic resin specimen of Example 1, while the glossiness and the low temperature impact strength were low. In addition, in the case of the thermoplastic resin specimen of Comparative Example 4 having a late crosslinking agent injection time, small-diameter particles were not confirmed, and the impact strength, glossiness, and low temperature impact strength were all lower than those of the thermoplastic resin specimens of Examples 1 to 5. It was.

In addition, in the case of the thermoplastic resin specimen of Comparative Example 5 having a high content of the fourth emulsifier of 0.75 parts by weight, the reaction time was shorter and the gloss was higher than that of the thermoplastic resin specimens of Examples 1 to 5, but the impact strength and the low temperature impact strength were high. Confirmed low. In particular, it can be seen that the content ratio of the large diameter diene rubber latex to the small diameter diene rubber latex included in the thermoplastic resin specimen of Comparative Example 5 is 96%: 4%, and the content ratio of the large diameter diene rubber latex is low.

In addition, in the case of the thermoplastic resin specimen of Comparative Example 6 having a low loading time of the fourth emulsifier of 45%, it can be seen that the impact strength and the low temperature impact strength are significantly lower than those of the thermoplastic resin specimens of Examples 1 to 5.

Claims (26)

1. 60 to 75 parts by weight of the conjugated diene monomer, 1 to 3 parts by weight of the first emulsifier, 0.2 to 0.4 parts by weight of the polymerization initiator, 0.2 to 3 parts by weight of the electrolyte, 0.1 to 0.5 parts by weight of the molecular weight regulator 65 parts by weight and 100 parts by weight of ion-exchanged water in a reactor and polymerization;

   2 steps of collectively adding 10 to 20 parts by weight of the conjugated diene monomer, and 0.1 to 1.0 parts by weight of the second emulsifier at a time when the polymerization conversion rate of the polymerization reaction is 30% to 40%;

   3 steps of polymerizing a batch or continuous addition of a residual amount of the conjugated diene monomer and 0 parts by weight to 1 part by weight of the third emulsifier optionally at a polymerization conversion rate of 60% to 70%; And

   In the manufacturing method of the diene-based rubber latex comprising; 4 steps of terminating the polymerization by adding a polymerization inhibitor when the polymerization conversion rate of the polymerization reaction is 92% or more,

   Method for producing a diene-based rubber latex, characterized in that further comprising the step of adding 0.05 to 0.3 parts by weight of the crosslinking agent at a time point of 0 to 50% of the polymerization conversion of the polymerization proceeding through the steps 1 and 2.
2. The method according to claim 1,

   The method adds 0.01 parts by weight to 0.5 parts by weight of a fourth emulsifier having a critical micelle concentration (CMC) of 150 mg / L or less at a polymerization conversion rate of 50% to 85% when the polymerization proceeds through the first and second polymerization stages. Method for producing a diene rubber latex comprising the step of introducing into.
3. The method according to claim 1,

   The conjugated diene monomer is a method for producing a diene rubber latex, characterized in that the conjugated diene monomer mono-, or a monomer mixture containing the conjugated diene monomer as a main component.
4. The method according to claim 1,

   The monomer mixture is 55 to 99.7% by weight of the conjugated diene monomer;

   0.1 wt% to 40 wt% of an aromatic vinyl monomer; And

   Method for producing a diene rubber latex comprising 0.1 to 40% by weight of vinyl cyanic monomer.
5. The method according to claim 3 or 4,

   The conjugated diene monomer is a 1,3-butadiene, isoprene, chloroprene and piperylene (piperylene) method for producing a diene rubber latex, characterized in that a single or a mixture of two or more.
6. The method according to claim 4,

   The aromatic vinyl monomer is a method for producing a diene rubber latex, characterized in that at least one selected from the group consisting of styrene, α-methyl styrene, α-ethyl styrene and p-methyl styrene.
7. The method according to claim 4,

   The vinyl cyan monomer is a method for producing a diene rubber latex, characterized in that at least one selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile.
8. The method according to claim 1,

   The first, second and third emulsifiers are each independently allyl aryl sulfonate, alkali methyl alkyl sulfates, sulfonated alkyl esters, fatty acid soaps, rosin acid alkali salts, sodium lauryl sulfonate, potassium oleate, Sodium alkylbenzene sulfonate, polyoxyethylene alkylphenyl ether, sodium dodecyl allyl sulfosuccinate, C _16-18 alkenyl succinic acid di-potassium salt, sodium acrylamistearate, polyoxyethylene alkylphenylether ammonium sulfate and A method for producing a diene-based rubber latex, characterized in that a single substance or a mixture of two or more selected from the group consisting of polyoxyethylene alkyl ether ester ammonium salts.
9. The method according to claim 1,

   The first step of the polymerization is a method for producing a diene rubber latex, characterized in that carried out at a temperature range of 65 ℃ to 70 ℃.
10. The method according to claim 1,

    The second step of the polymerization is a method for producing a diene rubber latex, characterized in that carried out at a temperature range of 72 ℃ to 75 ℃.
11. The method according to claim 1,

    The polymerization step 3 is a method for producing a diene rubber latex, characterized in that carried out at a temperature range of 80 ℃ to 85 ℃.
12. The method according to claim 1,

    The crosslinking agent comprises (alkylene glycol) _n diacrylate or (alkylene glycol) _n triacrylate, wherein n is an integer from 3 to 15.
13. The method according to claim 12,

    The crosslinking agent is at least one selected from the group consisting of (ethylene glycol) ₈ diacrylate, (ethylene glycol) ₁₂ diacrylate, (propylene glycol) ₈ diacrylate and (propylene glycol) ₁₂ diacrylate. Method for producing diene rubber latex.
14. The method according to claim 2,

    The fourth emulsifier is a CMC 10 mg / L or less emulsifier or CMC 10 mg / L to 150 mg / L method for producing a diene rubber latex, characterized in that the emulsifier.
15. The method according to claim 14,

    The diene-based emulsifier of CMC 10 mg / L or less is characterized in that the addition of 0.01 to 0.3 parts by weight at a polymerization conversion rate of 60% to 85% of the polymerization reaction proceeds through the first step and the second step of polymerization. Method for producing rubber latex.
16. The method according to claim 14,

    The emulsifier of CMC 10 mg / L or less is a C _16-18 alkenyl succinic acid di-potassium salt, polyoxyethylene alkylphenyl ether or polyoxyethylene alkylphenyl ether ammonium sulfate production method of the diene rubber latex.
17. The method according to claim 14,

    The CMC 10 mg / L to 150 mg / L emulsifier is characterized in that the addition of 0.05 parts by weight to 0.5 parts by weight at 50% to 85% of the polymerization conversion rate of the polymerization reaction proceeds through the first step and the second step of polymerization. Process for producing a diene rubber latex
18. The method according to claim 14,

    The method of producing a diene rubber latex, characterized in that the emulsifier of CMC 10 mg / L to 150 mg / L is fatty acid soap or potassium oleate.
19. The method according to claim 1 or 2,

    The first emulsifier, the second emulsifier, the third emulsifier and the fourth emulsifier are all the same compound, or a method for producing a diene rubber latex, characterized in that different compounds.
20. A diene rubber latex prepared by the manufacturing method of claim 1,

    The diene rubber latex comprises a large diameter diene rubber latex having an average particle diameter of 2,600 mm to 5,000 mm and a small diameter diene rubber latex having an average particle diameter of 20 nm to 70 nm. Diene-based rubber latex, characterized in that the mixing ratio of the latex is 98% to 99.9% by weight: diene-based rubber latex of 0.01% to 2% by weight.
21. The method of claim 20,

    The diene rubber latex is a diene rubber latex, characterized in that the gel content of 70% to 84%.
22. The method of claim 20,

    The diene rubber latex, wherein the swelling index of the diene rubber latex is 11 to 25.
23. An acrylonitrile-butadiene-styrene copolymer comprising the diene rubber latex of claim 20.
24. The method according to claim 23,

    The acrylonitrile-butadiene-styrene copolymer

    40 wt% to 70 wt% of a diene rubber latex according to claim 21,

    20 wt% to 50 wt% of an aromatic vinyl compound, and

    An acrylonitrile-butadiene-styrene copolymer, comprising 10% to 40% by weight of a vinylcyan compound.
25. The method according to claim 23,

    The copolymer is acrylonitrile-butadiene-styrene graft copolymer, characterized in that it has a graft rate of 25% to 35%, and a product coagulant content of 0.01% to 0.1%.
26. A thermoplastic resin comprising the acrylonitrile-butadiene-styrene graft copolymer of claim 23.