KR102465200B1 - Method for preparing graft copolymer and method for preparing thermoplastic resin composition containing thereof - Google Patents

Abstract

The present disclosure relates to a method for producing a graft copolymer and a method for producing a thermoplastic resin composition comprising the same, and more particularly, to a method for producing a graft copolymer and a method for producing a thermoplastic resin composition comprising the same. It relates to a method for preparing a graft copolymer, in which a thiol compound having a specific structure is added in the polymerization step, and a method for preparing a thermoplastic resin composition comprising the same.
According to the present disclosure, the graft copolymer prepared by using a polymer coagulant and a specific thiol compound together has a synergistic effect of improving both impact strength and fluidity.

Description

Method for producing a graft copolymer and a method for producing a thermoplastic resin composition comprising the same

The present invention relates to a method for producing a graft copolymer and a method for producing a thermoplastic resin composition comprising the same, and more particularly, to a conjugated diene enlarged with a polymer coagulant by introducing an aromatic vinyl monomer and a vinyl cyan monomer to graft polymerization. It relates to a method for producing a graft copolymer having a synergistic effect of improving both impact strength and fluidity by adding a specific compound in the step, and a method for producing a thermoplastic resin composition comprising the same.

The ABS-based copolymer, represented by the acrylonitrile-butadiene-styrene copolymer, has good physical properties such as impact resistance, mechanical strength, moldability, and glossiness, so it is widely used in various fields such as electric parts, electronic parts, office equipment, and automobile parts. is being used sparingly.

This ABS-based copolymer is usually prepared by preparing butadiene rubber latex, and then graft polymerization of styrene and acrylonitrile thereto. At this time, physical properties such as impact resistance, mechanical strength, and gloss of the graft copolymer are greatly affected by the average particle diameter, particle size distribution, dispersion state, and coagulant content of the rubber latex.

In particular, the core technology of the high-impact ABS copolymer is the average particle diameter of polybutadiene latex (PBL) of the core, and the appropriate particle diameter of the rubber latex required for this is about 3,000 to 3,500 Å. . In general, PBL is produced by emulsion polymerization, which is advantageous for particle size control, and the large-diameter PBL as described above can be prepared by, for example, emulsion polymerization of small-diameter (about 1,000 to 1,500 Å) PBL, and then enlarging it, and emulsification. Direct preparation via polymerization is also possible.

Large-diameter PBL produced directly through emulsion polymerization has advantages in terms of impact resistance due to a narrow particle size distribution and low coagulant content, but the average particle diameter of rubber latex is closely related to the emulsion polymerization time, and in order to obtain a large-diameter PBL There was a problem that the process efficiency was low because a reaction of 30 hours or more was required.

Accordingly, a method of reducing the reaction time by adding an additive such as vinyl cyan monomer or continuously adding an emulsifier during emulsion polymerization has been proposed, but the effect is insignificant and when the polymerization reaction temperature is increased to increase the reaction rate, the latex particle size This resulted in another problem, such as a small size and an increase in the coagulant content.

On the other hand, the method of producing small-diameter PBL by enlarging it can shorten the reaction time by half, which is advantageous in terms of productivity, but usually uses an acid as a coagulant (particle thickening agent). There was a problem in that this is difficult, pH control is required, and a large amount of coagulate is generated.

In this regard, a method of enlarging small-diameter PBL using a polymer coagulant (agglomerated latex) has been proposed. The polymer coagulant has improved impact strength compared to acetic acid, but the PSD (Particle Size Distribution) is broad and fluidity is lowered, thereby lowering processability. There is a need for a technology that can solve this problem.

Korean Patent No. 384375

In order to solve the problems of the prior art as described above, the present substrate is a polymer flocculant and the following Chemical Formula 1

[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms) Using the compound represented by the method for producing a graft copolymer with excellent productivity and excellent impact resistance and fluidity while ensuring the stability of the latex intended to provide

In addition, an object of the present disclosure is to provide a method for preparing a thermoplastic resin composition having excellent impact resistance and fluidity, including the graft copolymer according to the above method.

In addition, the base material is a large-diameter rubber core; And a graft copolymer comprising a shell graft-polymerized by including an aromatic vinyl monomer and a vinyl cyan monomer in the core, wherein the large-diameter rubber core contains a polymer coagulant in a conjugated diene rubber, and the graft copolymer is Formula 1

[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms) A vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer comprising 2000 to 5500 ppm of the compound represented by intended to provide

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

In order to achieve the above object, the present substrate comprises the steps of preparing an enlarged conjugated diene rubber latex by adding a polymer coagulant to the conjugated diene rubber latex having an average particle diameter of 500 to 1,500 Å; and adding an aromatic vinyl monomer and a vinyl cyan monomer to the enlarged conjugated diene rubber latex and performing graft polymerization to prepare a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer; Polymerization is the following formula 1

[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms).

In addition, the present substrate includes the steps of preparing an enlarged conjugated diene rubber latex by adding a polymer coagulant to the conjugated diene rubber latex having an average particle diameter of 500 to 1,500 Å; adding an aromatic vinyl monomer and a vinyl cyan monomer to the enlarged conjugated diene rubber latex and performing graft polymerization to prepare a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer; and injecting the prepared graft copolymer and the aromatic vinyl compound-vinyl cyan compound copolymer into an extruder, melt-kneading, and then extruding;

[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms) It provides a method for producing a thermoplastic resin composition comprising a compound represented by.

According to the present description, a graft copolymer prepared by graft polymerization of a conjugated diene rubber latex enlarged with a polymer coagulant with an aromatic vinyl monomer and a vinyl cyan monomer in the presence of a compound having a specific structure has reduced molecular weight distribution and excellent graft rate. It has a synergistic effect of simultaneously improving fluidity and impact resistance.

The present inventors have found that the graft copolymer obtained by enlarging small-diameter conjugated diene rubber latex with a polymer coagulant and then graft polymerization with aromatic vinyl monomer and vinyl cyan monomer has excellent impact strength, but has a broad PSD (Particle Size Distribution) and thus has poor fluidity. As a result of continuous efforts to solve the low problems, when a thiol compound of a specific structure is added in the step of graft polymerization by adding aromatic vinyl monomer and vinyl cyan monomer to the conjugated diene rubber latex enlarged with a polymer coagulant, impact strength and fluidity are improved. All improved effects were confirmed, and based on this, the present invention was completed by further concentrating on research.

The manufacturing method of the graft copolymer and the manufacturing method of the thermoplastic resin composition according to the present disclosure will be described in detail separately as follows.

graft Method for preparing copolymer

The manufacturing method of the graft copolymer of the present disclosure includes the steps of preparing an enlarged conjugated diene rubber latex by adding a polymer coagulant to a conjugated diene rubber latex having an average particle diameter of 500 to 1,500 Å (hereinafter referred to as 'small-diameter rubber latex') ; and adding an aromatic vinyl monomer and a vinyl cyan monomer to the enlarged conjugated diene rubber latex and performing graft polymerization to prepare a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer; Polymerization is the following formula 1

[Formula 1]

(The R ₁ to R ₇ are each independently an alkyl group having 1 to 5 carbon atoms).

When the small-diameter rubber latex is enlarged with a polymer coagulant, a unique micro-agglomerated rubber structure is formed in the rubber latex, and the effect of improving the impact strength of the graft copolymer including the micro-agglomerated rubber is expressed.

The polymer coagulant may be added, for example, in an amount of 0.5 to 5 parts by weight, 1 to 4.5 parts by weight, 2 to 3.5 parts by weight, or 2 to 3 parts by weight, based on 100 parts by weight of the conjugated diene rubber latex (based on solid content), in this range The stability of the latex is excellent and has the effect of reducing the formation of clots.

The polymer coagulant may have, for example, an average particle diameter of 800 to 1500 Å, 900 to 1300 Å, or 900 to 1100 Å, and has excellent latex stability and thickening effect within this range.

In the present disclosure, the average particle diameter may be measured using an intensity Gaussian distribution (Nicomp 380) by a dynamic laser light scattering method.

The polymer coagulant may be, for example, a polymer coagulant polymerized including an unsaturated acid compound, and specifically may be a polymer coagulant polymerized including an unsaturated acid compound and a monomer copolymerizable therewith. great.

The unsaturated acid compound may be, for example, at least one selected from the group consisting of (meth)acrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, citraconic acid, and anhydrides thereof, and preferably includes (meth)acrylic acid. and, more preferably, it contains methacrylic acid, and in this case, the aggregation effect is excellent and the formation of coagulation is reduced, thereby contributing to the improvement of productivity.

The monomer copolymerizable with the unsaturated acid compound may be, for example, at least one selected from the group consisting of (meth)acrylic acid alkyl esters, aromatic vinyl compounds, and vinyl cyan compounds, in which case latex stability is excellent and coagulation is reduced It works.

The (meth)acrylic acid alkyl ester monomer may be, for example, a (meth)acrylic acid alkyl ester having 1 to 10 carbon atoms in the alkyl group, and specific examples include methyl (meth)acrylate, ethyl (meth)acrylate, (meth)acrylic acid propyl, ( It may be at least one selected from the group consisting of meth) acrylate n-butyl, (meth) acrylate isobutyl, (meth) acrylate tert-butyl, and (meth) acrylate 2-ethylhexyl, preferably ethyl acrylate, n-acrylic acid butyl, or a mixture thereof.

In the present description, (meth)acrylic acid alkyl ester includes both methacrylic acid alkyl ester and acrylic acid alkyl ester.

The aromatic vinyl monomer is, for example, styrene, α-methyl styrene, ο-methyl styrene, ρ-methyl styrene, m-methyl styrene, ethyl styrene, isobutyl styrene, t-butyl styrene, ο-brobo styrene, ρ-bro It may be at least one selected from the group consisting of parent styrene, m-bromo styrene, ο-chloro styrene, ρ-chloro styrene, m-chloro styrene, vinyltoluene, vinylxylene, fluorostyrene, and vinylnaphthalene.

The vinyl cyan compound may be, for example, acrylonitrile, methacrylonitrile, or a mixture thereof.

As another example, the polymer coagulant may be, for example, a polymer coagulant having a core-shell structure, and in this case, the effect of enlarging the small-diameter rubber latex is excellent, the stability of the enlarged rubber latex is excellent, and the formation of coagulation is reduced. It has a significant effect on improving productivity.

The core-shell structure polymer coagulant is, for example, 30 to 55% by weight of the core and 45 to 70% by weight of the shell, 35 to 50% by weight of the core and 50 to 65% by weight of the shell, or 40 to 50% by weight of the core and 50 to 50% by weight of the shell. It may be 60% by weight, and the hypertrophy rubber latex has excellent stability and reduced coagulation within this range, and when it is used in preparing a graft copolymer, mechanical properties such as impact strength and the like are excellent.

The core-shell structure polymer coagulant may include, for example, a core polymerized including 25 to 55% by weight of (meth)acrylic acid alkyl ester and 0 to 5% by weight of an unsaturated acid compound; and a shell enclosing the core, polymerized including 35 to 60% by weight of (meth)acrylic acid alkyl ester and 5 to 15% by weight of an unsaturated acid compound; may include, and to enlarge small-diameter rubber latex within this range Although the effect is excellent, the stability of the enlarged rubber latex is excellent, and the formation of coagulation is reduced, which contributes to the improvement of productivity.

The polymer coagulant of the core-shell structure includes, as another example, a core polymerized including 30 to 50% by weight of (meth)acrylic acid alkyl ester and 0 to 5% by weight of an unsaturated acid compound; and a polymerized shell surrounding the core, including 40 to 55 wt% of (meth)acrylic acid alkyl ester and 5 to 10 wt% of an unsaturated acid compound; Although the effect is excellent, the stability of the enlarged rubber latex is excellent, and the formation of coagulation is reduced, which contributes to the improvement of productivity.

The unsaturated acid compound used in the core of the polymer coagulant may be, for example, 0.1 to 5% by weight or 0.1 to 4% by weight.

The polymer coagulant may be polymerized by including, for example, 0.05 to 1 part by weight or 0.1 to 0.5 parts by weight of an initiator, and has an effect of improving polymerization efficiency within this range.

The initiator may be, for example, at least one selected from the group consisting of ammonium persulfate, sodium persulfate, potassium persulfate and butyl hydroperoxide, and in this case, there is an effect of improving polymerization efficiency.

The polymer coagulant may be polymerized by adding 0.1 to 2 parts by weight, 0.5 to 1.5 parts by weight, or 0.5 to 1 parts by weight of the emulsifier, for example.

The emulsifier is, for example, an alkyl sulfosuccinate metal salt and derivatives thereof having 12 to 18 carbon atoms, an alkyl sulfate ester and derivatives thereof having 12 to 20 carbon atoms, an alkyl sulfonic acid metal salt having 12 to 20 carbon atoms and derivatives thereof. may be more than one species.

The metal salt of alkyl sulfosuccinate having 12 to 18 carbon atoms or a derivative thereof is, for example, dicyclohexyl sulfosuccinate, dihexyl sulfosuccinate, di-2-ethyl hexyl sulfosuccinate sodium salt, di-2- It may be at least one selected from the group consisting of ethylhexyl sulfosuccinate potassium salt, dioctyl sulfosuccinate sodium salt and dioctyl sulfosuccinate potassium salt.

The alkyl sulfuric acid ester or derivative thereof having 12 to 20 carbon atoms, the metal salt of alkyl sulfonic acid having 12 to 20 carbon atoms or a derivative thereof is, for example, sodium lauryl sulfate, sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium octadecyl sulfate, sodium It may be at least one selected from the group consisting of oleic sulfate, potassium dodecyl sulfate, and potassium octadecyl sulfate.

In the step of preparing the enlarged conjugated diene rubber latex, for example, the temperature of the conjugated diene rubber latex having an average particle diameter of 500 to 1,500 Å is raised to 45 to 55 ℃ or 47 to 52 ℃, and then the polymer coagulant is added for 20 to 40 minutes. Alternatively, it can be stirred for 25 to 35 minutes, and within this range, the small-diameter rubber latex is uniformly enlarged and the latex stability is excellent.

The small-diameter rubber latex may have, for example, an average particle diameter of 500 to 1,500 Å, 700 to 1,200 Å, or 900 to 1,100 Å, and within this range, it can be enlarged with a large-diameter latex within a short time, so there is an advantage of excellent productivity.

The small-diameter rubber latex is, for example, 85 to 95 parts by weight of a total of 100 parts by weight of the conjugated diene monomer, 1 to 4 parts by weight of an emulsifier, 0.1 to 0.6 parts by weight of a polymerization initiator, 0.1 to 1 parts by weight of an electrolyte, 0.1 to 0.5 parts by weight of a molecular weight regulator Polymerizing at 50 to 60 ℃ by adding 70 to 130 parts by weight of ion-exchanged water in a batch; adding 0.05 to 1.2 parts by weight of an initiator at a polymerization conversion rate of 30 to 40%, and raising the temperature to 65 to 75° C. to perform polymerization; polymerizing by adding 5 to 15 parts by weight of a conjugated diene monomer at a polymerization conversion rate of 60 to 70%; and terminating the polymerization at a polymerization conversion rate of 93 to 98%; in this case, there is an effect of stably producing a small diameter rubber latex within a short time.

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

The emulsifier used in preparing the small-diameter rubber latex may be, for example, at least one selected from the group consisting of allyl aryl sulfonate, alkali methyl alkyl sulfonate, sulfonated alkyl ester, fatty acid soap and rosin acid alkali salt, In this case, the stability of the polymerization reaction is excellent, and rubber latex having a desired particle size can be prepared.

The electrolyte used in preparing the small-diameter rubber latex is, for example, KCl, NaCl, KHCO ₃ , NaHCO ₃ , K ₂ CO ₃ , Na ₂ CO ₃ , KHSO ₃ , K ₂ SO ₄ , NaHSO ₃ , K ₂ P ₂ O ₇ , Na ₂ P ₂ O ₇ , K ₃ PO ₄ , Na ₃ PO ₄ and K ₂ HPO ₄ may be at least one selected from the group consisting of, in this case, the stability of the latex is excellent.

The molecular weight control agent used in preparing the small-diameter rubber latex may be, for example, at least one selected from the group consisting of t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan and carbon tetrachloride, preferably t -Dodecyl mercaptan.

The initiator used in the preparation of the small-diameter rubber latex is, for example, cumene hydroperoxide, diisopropyl benzene hydroperoxide, azobis isobutylnitrile, tertiary butyl hydroperoxide, para-methane hydroperoxide, benzoyl peroxide, etc. of fat-soluble persulfate; peroxy monomers; and a redox-based polymerization initiator combining a reducing agent and an oxidizing agent.

The enlarged conjugated diene rubber latex may have, for example, an average particle diameter of 2,500 to 4,000 Å, 2,500 to 3,500 Å, 2,500 to 3,300 Å, or 2,900 to 3,300 Å, including the prepared latex within this range. When the copolymer is prepared, the impact strength of the prepared copolymer is excellent.

In the step of preparing a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer by adding an aromatic vinyl monomer and a vinyl cyan monomer to the enlarged conjugated diene rubber latex and performing graft polymerization, the graft polymerization is performed by the following formula One

[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms). All of them have excellent impact properties.

The R ₁ to R ₇ may be, for example, an alkyl group having 1 to 3 carbon atoms or an alkyl group having 1 to 2 carbon atoms. there is

As a specific example, the compound represented by Formula 1 may be 2,2,4,6,6-pentamethylheptane-4-thiol, and in this case, the molecular weight distribution is lowered and the grafting efficiency is excellent, thereby providing fluidity and impact strength. All of them work great.

The compound represented by Formula 1 is, for example, 0.25 to 0.55 parts by weight, 0.3 to 0.5 parts by weight, or 0.3 to 0.45 parts by weight based on 100 parts by weight of the total of the enlarged conjugated diene rubber latex, aromatic vinyl monomer and vinyl cyan monomer. In this range, the molecular weight distribution of the graft copolymer is reduced, thereby improving fluidity.

100 parts by weight of the total of the enlarged conjugated diene rubber latex, the aromatic vinyl monomer and the vinyl cyan monomer, for example, 50 to 70 parts by weight of the enlarged conjugated diene rubber latex, 20 to 40 parts by weight of the aromatic vinyl monomer, and 1 to 20 parts by weight of the vinyl cyan monomer parts by weight; or 55 to 65 parts by weight of the enlarged conjugated diene rubber latex, 25 to 35 parts by weight of an aromatic vinyl monomer, and 5 to 15 parts by weight of a vinyl cyan monomer; It works.

The compound represented by Chemical Formula 1 may be mixed with the aromatic vinyl monomer and the vinyl cyan monomer, for example, and added to the enlarged conjugated diene rubber latex, in which case the graft polymerization reaction proceeds uniformly.

The compound represented by Formula 1 serves as an example of a molecular weight regulator, and a separate molecular weight regulator may not be added during the graft polymerization reaction.

The aromatic vinyl compound may be, for example, at least one selected from the group consisting of styrene, α-methyl styrene, vinyltoluene, and chlorostyrene, and the vinyl cyan compound is, for example, acrylonitrile, methacrylonitrile, or a mixture thereof. can

The graft copolymer may have, for example, a molecular weight distribution (MWD) of 2.0 to 2.6, 2.1 to 2.5, 2.2 to 2.5, or 2.2 to 2.4, within this range, fluidity is improved and processability is excellent. there is

In the present description, the molecular weight distribution may be calculated as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn).

In the present description, the number average molecular weight (Mn) and the weight average molecular weight (Mw) are measured using tetrahydrofuran (THF) as a solvent at a temperature of 40° C. through gel chromatography (GPC) filled with porous silica as a column packing material, respectively. It can be obtained by measuring the relative value with respect to a standard PS (Standard polystyrene) sample.

The graft copolymer may have, for example, a graft rate of 30 to 42%, 33 to 40%, or 35 to 40%, and has excellent impact strength within this range.

In the present description, the graft rate is obtained by coagulating, washing and drying the graft polymer latex to obtain a powder form, put 2 g of this powder in 300 ml of acetone, stirred for 24 hours, and then separated the solution using an ultracentrifuge and separated acetone solution was dropped into methanol to obtain the ungrafted portion. It is dried and weighed, and then calculated according to Equation 1 below.

[Equation 1]

Graft rate (%) = Weight of grafted monomer (g) / Weight of rubber (g) x 100

During the graft polymerization, 0.01 to 1 part by weight of an initiator may be added as an example, and within the above range, the stability of the polymerization reaction is excellent and the polymerization efficiency is improved.

The initiator may include, for example, oil-soluble persulfates such as cumene hydroperoxide, diisopropyl benzenehydroperoxide, azobis isobutylnitrile, tert-butyl hydroperoxide, para-methane hydroperoxide, and benzoyl peroxide; peroxy monomers; and a redox-based polymerization initiator combining a reducing agent and an oxidizing agent.

In the polymerization of the graft copolymer, for example, it may be carried out by further including an oxidation-reduction-based catalyst. The oxidation-reduction catalyst is not limited as long as it is a type commonly used in preparing the graft copolymer, and may be selected and used as needed.

The step of preparing the graft copolymer may include, for example, agglomeration, aging, dehydration and drying of the latex prepared after the graft polymerization, and the graft copolymer prepared including the above step is in powder form. can be provided as The coagulation, aging, dehydration and drying steps are not particularly limited if the methods are generally used in the art.

The agglomeration step in the method for preparing the graft copolymer may include, for example, an acid coagulant such as sulfuric acid, phosphoric acid, hydrochloric acid, or the like, or a salt coagulant such as magnesium sulfate, aluminum sulfate, calcium chloride, and the like, alone or mixed.

Other reaction conditions such as reaction time, reaction temperature, pressure, time of input of reactants, etc. in the method for preparing the graft copolymer other than the above-described description are not particularly limited as long as they are within the range commonly used in the art to which the present invention belongs, and necessary It can be appropriately selected and implemented according to the

Method for producing a thermoplastic resin composition

인 공액디엔 고무 라텍스에 고분자 응집제를 투입하여 비대화된 공액디엔 고무 라텍스를 제조하는 단계; 상기 비대화된 공액디엔 고무 라텍스에 방향족 비닐 단량체 및 비닐시안 단량체를 투입하고 그라프트 중합시켜 비닐시안 화합물-공액디엔 화합물-방향족 비닐 화합물 그라프트 공중합체를 제조하는 단계; 및 제조된 그라프트 공중합체 및 방향족 비닐 화합물-비닐시안 화합물 공중합체를 압출기에 투입하고 융융혼련한 후 압출하는 단계;를 포함하되, 상기 그라프트 중합은 하기 화학식 1The method for producing the thermoplastic resin composition of the present invention has an average particle diameter of 500 to 1,500

preparing an enlarged conjugated diene rubber latex by adding a polymer coagulant to the artificial conjugated diene rubber latex; adding an aromatic vinyl monomer and a vinyl cyan monomer to the enlarged conjugated diene rubber latex and performing graft polymerization to prepare a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer; and adding the prepared graft copolymer and the aromatic vinyl compound-vinyl cyan compound copolymer to an extruder, melt-kneading, and then extruding;

[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms), and in this case, both impact strength and fluidity of the produced thermoplastic resin composition are improved. .

The aromatic vinyl compound-vinyl cyan compound copolymer may be, for example, a copolymer of an aromatic vinyl compound such as styrene or α-methylstyrene and a vinyl cyan compound such as acrylonitrile or methacrylonitrile.

The aromatic vinyl compound-vinyl cyan compound copolymer may have, for example, a weight average molecular weight of 100,000 to 200,000 g/mol, 110,000 to 170,000 g/mol, or 130,000 to 150,000 g/mol, and has excellent impact strength within this range. It works.

In this description, the weight average molecular weight is relative to a standard PS (Standard polystyrene) sample using tetrahydrofuran (THF) as a solvent at a temperature of 40° C. through gel chromatography (GPC) filled with porous silica as a column packing material. can be obtained by measuring

The aromatic vinyl compound-vinyl cyan compound copolymer may include, for example, 60 to 95% by weight, 65 to 90% by weight, or 70 to 85% by weight of an aromatic vinyl compound; And 5 to 40% by weight of the vinyl cyanide compound, 10 to 35% by weight, or 15 to 30% by weight; may be a copolymer polymerized including.

The melt-kneading may be carried out, for example, at 200 to 280°C, or 220 to 260°C.

The melt-kneading may be performed using, for example, a Banbari mixer, a single screw extruder, a twin screw extruder, a kneader reactor, and the like, and is not particularly limited.

In the melt-kneading, one or more additives selected from the group consisting of colorants, heat stabilizers, light stabilizers, reinforcing agents, fillers, flame retardants, lubricants, plasticizers, antistatic agents and processing aids may be optionally added as needed.

In the method for producing the thermoplastic resin composition, content overlapping with the step of preparing the above-described graft copolymer was omitted.

The thermoplastic resin composition has an Izod impact strength (thickness 1/4") of 26 kgf · cm/cm or more, or 26 to 30 kgf · cm/cm measured according to ASTM D256, for example, and has an impact strength within the above range It is excellent and can be applied to various products.

The thermoplastic resin composition may have, for example, a flow index (220°C, 10 kg) measured according to ASTM D1238 of 18 g/10 min or more, 18 to 25 g/10 min, or 18.8 to 20 g/10 min, and this It has an effect of easy processing due to excellent fluidity within the range.

The present invention may include, for example, a method for manufacturing an injection-molded article comprising the method for manufacturing a thermoplastic resin composition according to the present disclosure.

The method of manufacturing the injection-molded article may include, for example, injection-molding the thermoplastic resin composition according to the present disclosure using an injection machine.

The injection-molded article may be, for example, an electric part, an electronic part, an office device, or an automobile part.

The vinyl cyanide compound-conjugated diene compound-aromatic vinyl compound graft copolymer of the present disclosure includes a large-diameter rubber core; And a graft copolymer comprising a shell graft-polymerized by including an aromatic vinyl monomer and a vinyl cyan monomer in the core, wherein the large-diameter rubber core contains a polymer coagulant in a conjugated diene rubber, and the graft copolymer is Formula 1

[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms) It is characterized in that it contains the compound represented by 2000 to 5500 ppm, and in this case, the impact strength and fluidity are excellent.

The graft copolymer may include, for example, the compound represented by Formula 1 in an amount of 2500 to 5000 ppm, 3000 to 4800 ppm, or 3200 to 4500 ppm, within this range, both impact strength and fluidity have excellent effects. have.

The content of the compound represented by Formula 1 in the graft copolymer may be obtained from the following formula after measuring the content of element S using ion chromatography (IC-AQP).

[Equation 2]

Content (ppm) of formula 1 = [(S element content of final graft copolymer - element S content of small-diameter rubber latex)] X (molecular weight of formula 1)/(molar mass of element S)

Hereinafter, preferred examples are presented to help the understanding of the present description, but the following examples are merely illustrative of the present description, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present description, It goes without saying that such variations and modifications fall within the scope of the appended claims.

[Example]

<Preparation Example 1: Preparation of polymer flocculant>

208 parts by weight of distilled water and 0.75 parts by weight of an emulsifier (dioctyl sulfosuccinate sodium, DOSS) were added to the reactor and stirred while the temperature was raised to 80° C., and then 0.2 parts by weight of an initiator (potassium persulfate, KPS) and butyl acrylate (BA ) 50 parts by weight was added and reacted for 90 minutes. After that, 41 parts by weight of butyl acrylate and 9 parts by weight of methacrylic acid (MAA) were added and reacted, and finally, a core-shell structure polymer coagulant having an average particle diameter of 1,000 Å (weight ratio of core to shell 50:50, core was 50 parts by weight of BA, including 41 parts by weight of BA and 9 parts by weight of MAA) were obtained.

<Preparation Example 2: Preparation of small-diameter rubber latex>

75 parts by weight of ion-exchanged water in a nitrogen-substituted polymerization reactor, 90 parts by weight of 1,3-butadiene as a monomer, 3 parts by weight of a dimer acid potassium salt (Cas No.67701-19-3) as an emulsifier, potassium carbonate ( K2CO3) 0.1 parts by weight, tertiary dodecyl mercaptan (TDDM) 0.1 parts by weight as a molecular weight regulator, 0.15 parts by weight of tertiary butyl hydroperoxide as an initiator, 0.06 parts by weight dextrose, 0.005 parts by weight of sodium pyrrole phosphate and ferrous sulfate 0.0025 parts by weight was added in a batch, and polymerization was initiated at 55°C. After adding 0.3 wt% of potassium persulfate at a polymerization conversion rate of 30 to 40%, the temperature was raised to 72° C. for polymerization reaction, and then 10 parts by weight of 1,3-butadiene was added at a polymerization conversion rate of 60 to 70%, followed by a polymerization conversion rate of 95 % to complete the reaction. At this time, the average particle diameter of the small-diameter rubber latex was 1,000 Å.

<Preparation Example 3: Large-diameter rubber latex production by thickening with a polymer coagulant>

After stirring 100 parts by weight (based on solid content) of the small-diameter rubber latex (average particle diameter of 1,000 Å) prepared in Preparation Example 2 to 50° C. in a reactor, the core-shell structure polymer coagulant prepared in Preparation Example 1 was added to 2.2 After adding parts by weight, the mixture was enlarged by stirring for 30 minutes. At this time, the enlarged rubber latex had an average particle diameter of 2930 Å and PSD was 0.65.

<Preparation Example 4: Large-diameter rubber latex production by thickening with a polymer coagulant>

After stirring 100 parts by weight (based on solid content) of the small-diameter rubber latex (average particle diameter of 1,000 Å) prepared in Preparation Example 2 in a reactor while raising the temperature to 50° C., the core-shell structure polymer coagulant prepared in Preparation Example 1 was 1.1 After adding parts by weight, the mixture was enlarged by stirring for 30 minutes. At this time, the enlarged rubber latex had an average particle diameter of 2,540 Å, and PSD was 0.68.

<Preparation Example 5: Preparation of large-diameter rubber latex by enlarging with a polymer coagulant>

After stirring 100 parts by weight (based on solid content) of the small-diameter rubber latex (average particle diameter of 1,000 Å) prepared in Preparation Example 2 in a reactor while raising the temperature to 50° C., the core-shell structure polymer coagulant prepared in Preparation Example 1 was added to 3.3 After adding parts by weight, the mixture was enlarged by stirring for 30 minutes. At this time, the enlarged rubber latex had an average particle diameter of 3,110 Å, and PSD was 0.60.

<Preparation Example 6: Large-diameter rubber latex production by thickening with a polymer coagulant>

After stirring 100 parts by weight (based on solid content) of the small-diameter rubber latex (average particle diameter of 1,000 Å) prepared in Preparation Example 2 in a reactor while raising the temperature to 50° C., the core-shell structure polymer coagulant prepared in Preparation Example 1 was added to 4.4 After adding parts by weight, the mixture was enlarged by stirring for 30 minutes. At this time, the enlarged rubber latex had an average particle diameter of 3,300 Å, and PSD was 0.56.

<Preparation Example 7: Large-diameter rubber latex production by hypertrophy with acetic acid>

After stirring 100 parts by weight (based on solid content) of the small-diameter rubber latex (average particle diameter of 1,000 Å) prepared in Preparation Example 2 in a reactor while raising the temperature to 40° C., 0.1 parts by weight of a stabilizing emulsifier and 2.83 parts by weight of acetic acid were added, followed by stirring for 10 minutes. and enlarged, at this time, the enlarged rubber latex had an average particle diameter of 3080 Å, and PSD was 0.37.

<Preparation of graft copolymer and thermoplastic resin composition>

Example One

28.8 parts by weight of styrene, 11.2 parts by weight of acrylonitrile and 2,2,4,6,6-pentamethylheptane-4-thiol (PMH) in 60 parts by weight (based on solid content) of the enlarged rubber latex prepared in Preparation Example 3 0.34 parts by weight were mixed, continuously added for 3 hours, and graft polymerization was performed to obtain an ABS graft copolymer latex. 1.2 parts by weight of an emulsion (average particle diameter of 0.9 μm) obtained by mixing the obtained ABS graft copolymer latex with Wingstay-L (Raton Korea) and IR107 (Raton Korea) in a weight ratio of 0.8:0.2 as an antioxidant, and then 84 After the temperature was raised to °C, 3.0 parts by weight of magnesium sulfate (MgSO ₄ ) was added and agglomerated. Thereafter, the temperature was raised to 94° C. over 10 minutes, and after dehydration in a dehydrator, a powder was obtained after drying in an oven.

Then, 25% by weight of the ABS graft copolymer powder and 75% by weight of the acrylonitrile-styrene copolymer were added to a mixer and mixed, and then pelletized using a twin-screw extruder, and then a specimen for measuring physical properties using an injection machine was produced. The acrylonitrile-styrene copolymer has a weight average molecular weight of 140,000 g/mol, and is a copolymer comprising 24% by weight of acrylonitrile and 76% by weight of styrene.

Example 2

Example 1 was carried out in the same manner as in Example 1, except that 0.42 parts by weight of 2,2,4,6,6-pentamethylheptane-4-thiol was used.

Example 3

Example 1 was carried out in the same manner as in Example 1, except that 0.50 parts by weight of 2,2,4,6,6-pentamethylheptane-4-thiol was used.

Example 4

Example 1 was carried out in the same manner as in Example 1, except that the enlarged rubber latex prepared in Preparation Example 4 was used instead of the enlarged rubber latex prepared in Preparation Example 3.

Example 5

Example 1 was carried out in the same manner as in Example 1, except that the hypertrophic rubber latex prepared in Preparation Example 5 was used instead of the enlarged rubber latex prepared in Preparation Example 3.

Example 6

Example 1 was carried out in the same manner as in Example 1, except that the enlarged rubber latex prepared in Preparation Example 6 was used instead of the enlarged rubber latex prepared in Preparation Example 3.

comparative example One

In Example 1, in the same manner as in Example 1, except that 0.34 parts by weight of t-dodecyl mercaptan (TDDM) was used as a molecular weight regulator instead of 2,2,4,6,6-pentamethylheptane-4-thiol. carried out.

comparative example 2

Example 1 was carried out in the same manner as in Example 1, except that 0.50 parts by weight of t-dodecyl mercaptan was used instead of 2,2,4,6,6-pentamethylheptane-4-thiol.

comparative example 3

Example 1 was carried out in the same manner as in Example 1, except that 0.34 parts by weight of t-dodecyl mercaptan was used in the enlarged rubber latex prepared in Preparation Example 7 instead of the enlarged rubber latex prepared in Preparation Example 3 .

comparative example 4

Except that 0.42 parts by weight of 2,2,4,6,6-pentamethylheptane-4-thiol was used in the enlarged rubber latex prepared in Preparation Example 7 instead of the enlarged rubber latex prepared in Preparation Example 3 in Example 1 and carried out in the same manner as in Example 1.

Reference example One

Example 1 was carried out in the same manner as in Example 1, except that 0.10 parts by weight of 2,2,4,6,6-pentamethylheptane-4-thiol was used.

Reference example 2

Example 1 was carried out in the same manner as in Example 1, except that 0.65 parts by weight of 2,2,4,6,6-pentamethylheptane-4-thiol was used.

[Test Example]

The properties of the specimens prepared in Examples 1 to 6, Comparative Examples 1 to 4, and Reference Examples 1 to 2 were measured by the following method, and the results are shown in Tables 1 and 2 below.

How to measure

) 측정: 입도분석기(particle size analyzer: NICOMP 380)로 측정하였다.* Average particle diameter (

) Measurement: It was measured with a particle size analyzer (NICOMP 380).

* PSD (Particle Size Distribution): It was measured with a particle size analyzer (NICOMP 380).

* Number average molecular weight (Mn; g/mol): Relative to standard PS (Standard polystyrene) sample using THF as a solvent at a temperature of 40 ° C through gel chromatography (GPC) filled with porous silica as a column packing material The values were measured.

* Weight average molecular weight (Mw; g/mol): Relative to standard PS (Standard polystyrene) samples using THF as a solvent at a temperature of 40 ° C through gel chromatography (GPC) filled with porous silica as a column packing material The values were measured.

* Molecular Weight Distribution (MWD): It was calculated as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn).

* Graft rate (GR; %): The graft polymer latex is coagulated, washed and dried to obtain a powder form, and 2 g of this powder is added to 300 ml of acetone and stirred for 24 hours, and then the solution is separated using an ultracentrifuge and separated. The acetone solution is dropped into methanol to obtain an ungrafted portion. It was dried and weighed, and then calculated according to the following formula.

[Equation 1]

Graft rate (%) = Weight of grafted monomer (g) / Weight of rubber (g) x 100

* Izod impact strength (kgf·cm/cm): It was measured according to ASTM D256 with a specimen thickness of 1/4″.

* Flow index (MI; g/10 min): Measured according to ASTM D1238 under the condition of 220 °C/10 kg.

* PMH content (ppm) in the graft resin: The content of S element was measured using Ion Chromatography (ICAQP) analysis, and then obtained through the following formula.

[Equation 2]

PHM content (ppm) = [(S element content of final graft copolymer - S element content of small-diameter rubber latex)] X (molecular weight of PHM)/(molar mass of element S)

In Equation 2, the molecular weight of the PHM was 202.40 g/mol, and the molar mass of the S element was 32.07 g/mol.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 large diameter
rubber
latex type Preparation 3 Preparation 3 Preparation 3 Preparation 4 Preparation 5 Preparation 6 polymer
flocculant
(parts by weight) 2.2 2.2 2.2 1.1 3.3 4.4 average particle diameter
(Å) 2930 2930 2930 2540 3110 3300 PSD 0.65 0.65 0.65 0.68 0.60 0.56 ABS
graft
copolymer PMH
(parts by weight) 0.34 0.42 0.50 0.42 0.42 0.42 Mn(×10 ⁵ ) 3.60 3.42 3.08 3.38 3.44 3.40 Mw(×10 ⁵ ) 8.01 8.10 7.25 8.00 7.88 8.09 MWD 2.25 2.37 2.41 2.36 2.29 2.38 PSD 0.64 0.65 0.65 0.69 0.61 0.56 GR (%) 39.7 36.1 33.6 35.7 36.0 36.5 PMH content
(ppm) 3220 4010 4760 3980 4010 3930 thermoplastic
Suzy
composition impact strength 27.4 29.0 26.0 28.8 29.2 29.0 MI 19.1 19.4 19.3 20.0 18.9 18.8

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Reference Example 1 Reference Example 2 large diameter
rubber
latex type Preparation 3 Preparation 3 Preparation 7 Preparation 7 Preparation 3 Preparation 3 polymer
flocculant
(parts by weight) 2.2 2.2 - - 2.2 2.2 acetic acid
(parts by weight) - - 1.7 1.7 - - average particle diameter
(Å) 2930 2930 3080 3080 2950 2950 PSD 0.65 0.65 0.37 0.37 0.64 0.64 ABS
graft
copolymer PMH
(parts by weight) - - - 0.42 0.1 0.65 TDDM
(parts by weight) 0.34 0.50 0.34 - - - Mn(×10 ⁴ ) 3.84 3.60 3.60 3.52 4.98 2.78 Mw(×10 ⁴ ) 10.9 10.3 10.5 8.08 12.60 7.22 MWD 2.84 2.91 2.90 2.31 2.54 2.60 PSD 0.63 0.64 0.38 0.40 0.66 0.69 GR (%) 46.8 45.4 31.4 33.2 55.2 30.7 PMH content
(ppm) - - - 3500 430 5400 thermoplastic
Suzy
composition impact strength 25.3 19.5 20.9 20.5 24.5 23.5 MI 17.1 19.0 20.8 22.1 14.9 23.3

As shown in Tables 1 and 2, Examples 1 to 6 containing the polymer coagulant according to the present invention and 2,2,4,6,6-pentamethylheptane-4-thiol are prepared graft copolymers The MWD is low and the graft rate is within 30 to 42%, and the thermoplastic resin composition including the same has an excellent synergistic effect in both impact strength and fluidity.

On the other hand, Comparative Examples 1 and 2 containing the polymer coagulant and t-dodecyl mercaptan had a high MWD of the graft copolymer and a graft rate exceeding 42%, and the thermoplastic resin composition including the same had both impact strength and fluidity. was lowered

In addition, Comparative Examples 3 and 4 including acetic acid have narrow PSD and have excellent fluidity, but unlike rubber latex in which a polymer coagulant is added, a unique micro-agglomerated rubber structure is not formed in the rubber latex coagulated with acetic acid. As a result, the impact strength was lowered.

In addition, in Reference Example 1 containing 0.1 parts by weight of 2,2,4,6,6-pentamethylheptane-4-thiol in the polymer coagulant, the weight average molecular weight and graft rate were very high compared to Examples 1 to 6, and fluidity was lowered. Reference Example 2 containing 0.65 parts by weight of 2,2,4,6,6-pentamethylheptane-4-thiol as a polymer coagulant had a very low weight average molecular weight and reduced impact strength compared to Examples 1 to 6.

Claims (15)

preparing an enlarged conjugated diene rubber latex by adding a polymer coagulant to the conjugated diene rubber latex having an average particle diameter of 500 to 1,500 Å; and
Including an aromatic vinyl monomer and a vinyl cyan monomer in the enlarged conjugated diene rubber latex and graft polymerization to prepare a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer;
The graft polymerization is represented by the following Chemical Formula 1
[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms) 0.25 to 0.45 parts by weight based on 100 parts by weight of the total of the enlarged conjugated diene rubber latex, aromatic vinyl monomer and vinyl cyan monomer put in,
The compound represented by Formula 1 is mixed with the aromatic vinyl monomer and the vinyl cyan monomer and added to the enlarged conjugated diene rubber latex,
The graft copolymer is characterized in that the molecular weight distribution is 2.1 to 2.5
Method for producing a graft copolymer.
According to claim 1,
The polymer coagulant is added in an amount of 0.5 to 5 parts by weight based on 100 parts by weight (based on solid content) of the conjugated diene rubber latex.
Method for producing a graft copolymer.
According to claim 1,
The polymer coagulant is characterized in that the average particle diameter is 800 to 1500 Å.
Method for producing a graft copolymer.
According to claim 1,
The polymer coagulant is a polymer coagulant polymerized including an unsaturated acid compound
Method for producing a graft copolymer.
According to claim 1,
The polymer flocculant is a core-shell structure polymer flocculant
Method for producing a graft copolymer.
6. The method of claim 5,
The core-shell structure polymer coagulant comprises 30 to 55% by weight of the core and 45 to 70% by weight of the shell.
Method for producing a graft copolymer.
6. The method of claim 5,
The polymer coagulant comprises: a core polymerized including 25 to 55 wt% of a (meth)acrylic acid alkyl ester and 0 to 5 wt% of an unsaturated acid compound; and a shell wrapped around the core and polymerized including 35 to 60% by weight of (meth)acrylic acid alkyl ester and 5 to 15% by weight of an unsaturated acid compound.
Method for producing a graft copolymer.
According to claim 1,
In the step of preparing the enlarged conjugated diene rubber latex, the temperature of the conjugated diene rubber latex having an average particle diameter of 500 to 1,500 Å is raised to 45 to 55 ° C.
Method for producing a graft copolymer.
According to claim 1,
The enlarged conjugated diene rubber latex is characterized in that the average particle diameter is 2500 to 4000 Å.
Method for producing a graft copolymer.
delete delete delete According to claim 1,
The graft copolymer is characterized in that the graft rate is 30 to 42%
Method for producing a graft copolymer.
Average particle diameter 500 to 1,500

preparing an enlarged conjugated diene rubber latex by adding a polymer coagulant to the artificial conjugated diene rubber latex;
adding an aromatic vinyl monomer and a vinyl cyan monomer to the enlarged conjugated diene rubber latex and performing graft polymerization to prepare a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer; and
Putting the prepared vinyl cyan compound-conjugated diene compound-aromatic vinyl compound graft copolymer and aromatic vinyl compound-vinyl cyan compound copolymer into an extruder, melt-kneading, and then extruding;
The graft polymerization is represented by the following Chemical Formula 1
[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms) 0.25 to 0.45 parts by weight based on 100 parts by weight of the total of the enlarged conjugated diene rubber latex, aromatic vinyl monomer and vinyl cyan monomer including,
The compound represented by Formula 1 is mixed with the aromatic vinyl monomer and the vinyl cyan monomer and added to the enlarged conjugated diene rubber latex,
The graft copolymer is characterized in that the molecular weight distribution is 2.1 to 2.5
A method for producing a thermoplastic resin composition.
large diameter rubber core; And a graft copolymer comprising a shell graft-polymerized including an aromatic vinyl monomer and a vinyl cyan monomer in the core,
The large-diameter rubber core contains a polymer coagulant in a conjugated diene rubber,
The graft copolymer is prepared by the following Chemical Formula 1
[Formula 1]

(The R ₁ to R ₇ are independently an alkyl group having 1 to 5 carbon atoms) containing the compound represented by 2000 to 5500 ppm,
The graft copolymer is a vinyl cyanide compound-conjugated diene compound-aromatic vinyl compound graft copolymer, characterized in that the molecular weight distribution is 2.1 to 2.5.