KR20240062099A - Copolymer, method thereof and thermoplastic resin composition comprising the copolymer - Google Patents

Abstract

The present invention relates to an acrylic-imide-based copolymer, comprising an alkyl (meth)acrylate-based monomer unit; Aromatic vinyl monomer unit; and an imide-based monomer unit; a copolymer comprising a plurality of copolymer chains and a glass transition temperature of 109° C. to 133° C., wherein the imide-based monomer unit is present in an amount of 20 parts by weight based on 100 parts by weight of the total copolymer. An acrylic-imide-based copolymer is provided, which includes the following, and the residual monomer content in the copolymer is 1.3% by weight or less. The copolymer has an advantage in that it has little compositional variation and can have a glass transition temperature at an appropriate level compared to imide-based monomers, thereby ensuring excellent heat resistance and transparency at the same time.

Description

Copolymer, manufacturing method thereof, and thermoplastic resin composition comprising the copolymer {COPOLYMER, METHOD THEREOF AND THERMOPLASTIC RESIN COMPOSITION COMPRISING THE COPOLYMER}

The present invention relates to an acrylic-imide-based copolymer that has a high glass transition temperature even though the amount of imide-based monomer used is small.

Recently, with the development of optical technology, liquid crystal displays have been required to be thinner, lighter, and larger throughout the display industry, and technologies such as wide viewing angle, high contrast, uniform screen display, and suppression of image change according to viewing angle have emerged as particularly important issues. It is becoming. As a result, the required characteristics of polymer materials used in display manufacturing are becoming more sophisticated.

Accordingly, various display technologies such as plasma displays (PDPs), liquid crystal displays (LCDs), and organic EL displays (LEDs) that replace conventional cathode ray tubes (CRTs) are being proposed and sold. Meanwhile, various polymer films such as polarizing films, polarizer protective films, retardation films, light guide plates, and plastic substrates are used in these display devices, and the required characteristics of these display polymer materials are becoming more sophisticated.

Currently, the most widely used display polymer film is a polarizer protective film, TriAcetyl Cellulose (TAC). When this TAC film is used for a long time in a high temperature or high humidity atmosphere, the degree of polarization decreases, the polarizer and the film separate, or the film is exposed to light. There is a problem that the characteristics are deteriorated. To solve this problem, polymer films based on methyl methacrylate, polystyrene, or polycarbonate have been proposed. These polymer films have the advantage of excellent heat resistance, but in the case of polystyrene or polycarbonate films, because they have an aromatic ring in the polymer, birefringence occurs during orientation, causing problems in optical properties. In the case of methyl methacrylate, polystyrene or polycarbonate films have an aromatic ring in the polymer. Although the retardation value is relatively small compared to polycarbonate, it is not sufficient by itself to be applied to optical materials that require high precision.

In order to overcome the above problems, previous researchers have conducted research on copolymerizing methyl methacrylate with various types of monomers, and among them, copolymerization with styrene and maleic anhydride has been known to be helpful in increasing heat resistance. However, copolymers with maleic anhydride have problems with stability during molding processing and have problems such as decomposition or gel formation due to high molding processing temperatures, which limits their use.

In addition, in the case of the cyclohexyl maleimide, it is a material subject to environmental regulations. In particular, when the resin composition is extruded into a film, the cyclohexyl maleimide remaining in the resin generates a irritating and harmful odor, which reduces production efficiency and reduces the process. There was a problem with instability.

In comparison, when phenylmaleimide is applied, it has the advantage of less irritating odor generated during film extrusion and improved thermal stability. There have been attempts to utilize this, but when phenylmaleimide is used, it has the advantage of reducing reactivity with other monomers. The difference is that there is a significant difference in composition between the copolymer produced at the beginning of the process during the polymerization reaction and the copolymer at the end of the process. Due to this composition imbalance, it is difficult to ensure heat resistance characteristics and there is a problem that transparency is also reduced.

KR 1739621 B1

The present invention aims to provide an acrylic-imide-based copolymer with low compositional variation between copolymer chains, excellent glass transition temperature, and excellent transparency due to low residual monomer content by controlling the reactivity between monomers by adding imide-based monomers during polymerization. do. In addition, the present invention seeks to provide a thermoplastic resin composition that includes the above copolymer and has excellent heat resistance and impact strength, as well as excellent transparency.

In order to solve the above problems, the present invention provides an alkyl (meth)acrylate-based monomer unit; Aromatic vinyl monomer unit; and an imide-based monomer unit; a copolymer comprising a plurality of copolymer chains and a glass transition temperature of 109° C. to 133° C., wherein the imide-based monomer unit is present in an amount of 14 parts by weight based on 100 parts by weight of the total copolymer. It provides an acrylic-imide-based copolymer including the following, and the residual monomer content in the copolymer is 1.3% by weight or less.

In addition, in order to solve the above problem, the present invention includes the step (S1) of initiating polymerization by introducing a reaction solution containing an alkyl (meth)acrylate-based monomer and an aromatic vinyl-based monomer into a reactor; And a step (S2) of polymerizing a monomer solution containing an imide-based monomer while continuously adding it to the reactor, wherein the monomer solution in the (S2) step has a polymerization conversion rate of 50% to 70% after the (S1) step. It provides a method for producing an acrylic-imide-based copolymer, which is continuously added until the % is reached.

Additionally, in order to solve the above problems, the present invention provides a thermoplastic resin composition containing the above-described acrylic-imide-based copolymer.

The reactivity of the acrylic-imide-based copolymer according to the present invention can be controlled by adding an imide-based monomer that has different reactivity from other monomers during polymerization, and thus the composition variation between copolymer chains is small and the acrylic-imide-based copolymer has a high glass transition temperature. A polymer can be provided, and this copolymer has excellent transparency, so when applied to molded products, it can provide a transparent product with high heat resistance and impact strength.

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

Terms or words used in this specification and claims should not be construed as limited to their common or dictionary meanings, and the inventor may appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is.

Terms and measurement methods used in the present invention may be defined as follows unless otherwise defined.

The term 'composition' used in the present invention includes mixtures of materials containing the composition as well as reaction products and decomposition products formed from the materials of the composition.

The term 'monomer unit' used in the present invention may refer to a repeating unit formed when a compound used as a monomer or a compound used as a crosslinking agent participates in a polymerization reaction or crosslinking reaction, a structure resulting therefrom, or the material itself.

The term 'derivative' used in the present invention may refer to a compound having a structure in which one or more of the hydrogen atoms constituting the original compound are replaced by a halogen group, an alkyl group, or a hydroxy group.

In the present invention, 'polymerization conversion rate' refers to the degree to which monomers are polymerized through a polymerization reaction to form a polymer. A portion of the polymer in the reactor is collected during polymerization and the weight of the polymer excluding moisture is calculated through Equation 1 below. After dissolving the sample in tetrahydrofuran (THF) solvent, precipitating it with methanol (MeOH), unreacted monomers were removed, the precipitated suspended solid was dried, the weight of the obtained polymer was measured, and the following equation 2 was obtained: Calculate through

[Equation 1]

(Weight of actual polymer) = (Collected polymer) - (Collected polymer

[Equation 2]

Polymerization conversion rate (%) = [(Weight of polymer obtained by drying) / (Weight of actual polymer)]

Acrylic-imide copolymer and method for producing the same

According to the present invention, the acrylic-imide-based copolymer includes an alkyl (meth)acrylate-based monomer unit; Aromatic vinyl monomer unit; and an imide-based monomer unit; a copolymer comprising a plurality of copolymer chains and a glass transition temperature of 109° C. to 133° C., wherein the imide-based monomer unit is present in an amount of 20 parts by weight based on 100 parts by weight of the total copolymer. It is included as follows, and the residual monomer content in the copolymer is 1.3% by weight or less.

According to one embodiment of the present invention, the copolymer has a glass transition temperature of 109°C to 133°C, preferably 111°C to 128°C, and more preferably 112 to 120°C. The glass transition temperature may be linked to the content of the imide monomer unit, but even if the same content of the imide monomer is applied, there may be a slight change due to the difference in composition between copolymer chains, the composition of other monomers, or the residual monomer content. The copolymer according to the present invention is characterized in that it can achieve a high glass transition temperature even though the content of the imide monomer unit is less than 14 parts by weight.

Copolymers with a glass transition temperature lower than 109°C may have problems with heat resistance due to an imbalance in the monomer composition, and copolymers with a glass transition temperature higher than 133°C may have deteriorated transparency and discoloration. If the composition of the imide-based monomer unit occupies 14 parts by weight or less in total, it may have a glass transition temperature of 133 ℃ or lower, and if it contains 5 parts by weight or more, it may have a glass transition temperature of at least 109 ℃, preferably 113 ℃ or higher. You can.

According to one embodiment of the present invention, the copolymer contains imide-based monomer units in an amount of 20 parts by weight or less based on 100 parts by weight of the copolymer. If the imide-based monomer unit exceeds 20 parts by weight, there is a problem that the color of the copolymer may change and transparency may decrease.

According to one embodiment of the present invention, the residual monomer content in the copolymer may be 1.3 wt% or less, preferably 1.2 wt% or less, and more preferably 1.0 wt% or less. The residual monomer content is measured by gas chromatography, and the content may be high due to differences in reactivity between monomers, and may be high because polymerization does not proceed to the final polymerization conversion rate for other reasons. However, in the case of the present invention, Reactivity was controlled by adding an imide-based monomer during polymerization, and as a result, the polymerization conversion rate could be high while the residual monomer content could be low to 1.3% by weight or less. The residual monomer may be the total residual amount of aromatic vinyl monomer, alkyl (meth)acrylate monomer, and imide monomer used in the copolymerization of the present invention.

According to one embodiment of the present invention, the copolymer includes 40 to 90 parts by weight of the alkyl (meth)acrylate monomer, based on 100 parts by weight of the total copolymer; 5 to 50 parts by weight of aromatic vinyl monomer units; It may contain 1 to 20 parts by weight of imide-based monomer units. If the above range is satisfied, the desired level of glass transition temperature can be achieved, transparency can be achieved at an excellent level, and the compositional deviation between multiple chains can be low, so excellent impact strength and matte characteristics can be obtained at the same time. there is.

Preferably, based on the total 100 parts by weight of the copolymer, 50 to 85 parts by weight, or 60 to 80 parts by weight, of the alkyl (meth)acrylate monomer; 10 to 40 parts by weight, or 10 to 30 parts by weight, of an aromatic vinyl monomer unit; It may include 3 to 15 parts by weight or 4 to 10 parts by weight of imide-based monomer units.

The copolymer may be a random copolymer, and the composition of the alkyl (meth)acrylate-based monomer unit, aromatic vinyl-based monomer unit, and imide-based monomer unit in the copolymer may be uniform. Uniform composition of the monomer units may mean that the ratio of each monomer unit present in the polymer that is polymerized and grown through a polymerization reaction of monomers is maintained uniformly. As a specific example, as polymerization progresses, that is, as polymerization time changes during polymerization, this may mean that when a portion of the polymer in the reactor is sampled, the ratio of each monomer unit forming the polymer is maintained uniformly.

According to one embodiment of the present invention, the alkyl (meth)acrylate-based monomer unit, aromatic vinyl-based monomer unit, and imide-based monomer unit may refer to repeating units formed by each monomer participating in a polymerization reaction. As a specific example, the polymerization reaction may be a radical polymerization reaction, and thus may refer to a repeating unit derived from a carbon-carbon double bond present in each monomer.

According to one embodiment of the present invention, the copolymer may further include vinyl cyanide monomer units. When the vinyl cyanide monomer unit is included, mechanical properties such as excellent impact strength and tensile strength can be stably secured, and flowability is improved, which can also provide process advantages in molding such as injection or extrusion.

According to the present invention, when the alkyl (meth)acrylate monomer unit is 45 parts by weight or more based on 100 parts by weight of the total copolymer, the copolymer satisfies the following equation 1 between the glass transition temperature and the content of the imide monomer unit. is provided.

[Equation 1]

2.0 ≤ [(Tg)-100]/[W _I ] ≤ 4.2

Here, Tg is the unitless number of the glass transition temperature when the unit is ℃, and W _I is the imide monomer unit relative to 100 parts by weight (or weight %) of the total copolymer when the unit is parts by weight (or % by weight). It is an infinite number of contents.

The relationship between the glass transition temperature and the content of imide-based monomer units may mean that the compositional deviation between copolymer chains is small, and if the value is less than 2.0, it means that the composition is highly non-uniform, and exceeds 4.2. If the value appears, it may mean that the glass transition temperature is too high compared to the imide monomer content, which may lower the impact strength. In other words, a copolymer within the above range can ensure excellent transparency and excellent heat resistance and impact strength, and can mean that the residual monomer content is low, preferably 2.0 or more and may be 4.0 or less, and 2.0 or more. It may be 3.7 or less, more preferably 2.0 to 3.6.

Additionally, the above relationship can be satisfied when 45 parts by weight or more of alkyl (meth)acrylate monomer units are contained based on 100 parts by weight of the total copolymer. Generally, the more aromatic vinyl monomer units are included, the higher the glass transition temperature tends to be. Therefore, in order to determine the efficiency of realizing the glass transition temperature by imide monomer, the content of aromatic vinyl monomer units is a major influencing factor. Since it must not be , it needs to be satisfied.

According to one embodiment of the present invention, the copolymer may have a compositional deviation of imide-based monomer units within a plurality of chains of 3.50 or less. This may be a standard deviation value for the composition of the imide-based monomer unit measured by collecting samples four or more times during polymerization using an elemental analysis method. According to the production method according to an embodiment of the present invention, the composition deviation of the imide-based monomer unit may be 3.50 or less, preferably 3.00 or less, more preferably 2.50 or less, and even more preferably 2.00 or less. .

According to the present invention, the method for producing an acrylic-imide-based copolymer includes the step of initiating polymerization by introducing a reaction solution containing an alkyl (meth)acrylate-based monomer and an aromatic vinyl-based monomer into a reactor (S1); And a step (S2) of polymerizing a monomer solution containing an imide-based monomer while continuously adding it to the reactor, wherein the imide-based monomer is added from the step (S1) until the polymerization conversion rate is 50% to 70%. It is applied continuously.

According to one embodiment of the present invention, the (S1) step is a step of initiating polymerization, which may include adding the reaction solution into the reactor and then raising the temperature of the reactor to a predetermined temperature. Even in the step (S1), if the internal temperature of the reactor rises above the predetermined temperature, polymerization proceeds in the presence of a polymerization initiator. According to one embodiment of the present invention, the reaction solution must not contain an imide monomer. There is. If an imide-based monomer is included in the reaction solution and participates in the polymerization from the beginning of the polymerization, an excessive amount of imide-based monomer may be incorporated into the copolymer chain generated at the beginning of the process due to the high reactivity of the imide-based monomer, and an imide-based monomer may be formed at the end of the process. A relatively small amount of imide-based monomers may be incorporated into the copolymer chain, which may cause an imbalance in the composition between chains. As a result, there is a problem of reduced heat resistance, and the physical properties are not uniform for each sample and have deviations. Serious problems may arise.

Accordingly, in the production method according to an embodiment of the present invention, step (S1) may be performed without an imide-based monomer. Additionally, in the step (S1), the internal temperature of the reactor may be raised to about 60°C to 120°C, preferably 70°C to 110°C, more preferably 80°C to 110°C, and even more preferably 85°C to 105°C. It may be that the temperature is raised to . In the process of increasing the internal temperature of the reactor in the step (S1), the time of reaching the initial temperature may be before the polymerization conversion rate is 10%, before 7%, before 5%, or before 3%.

According to one embodiment of the present invention, the reaction solution includes an alkyl (meth)acrylate-based monomer, and the alkyl (meth)acrylate-based monomer is methyl (meth)acrylate, ethyl (meth)acrylate, and propyl. It may be one or more selected from the group consisting of (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, and lauryl (meth)acrylate, and specifically. , the alkyl (meth)acrylate monomer may be one or more selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.

In addition, according to one embodiment of the present invention, the alkyl (meth)acrylate-based monomer is 40 parts by weight to 90 parts by weight, 50 parts by weight to 85 parts by weight, or 60 parts by weight to 60 parts by weight, based on the total monomer input content. It can be added at 80 parts by weight, and within this range, a copolymer can be obtained with a high polymerization conversion rate, and the glass transition temperature can be easily controlled, so it can function to achieve impact strength and excellent transparency.

According to one embodiment of the present invention, the reaction solution includes an aromatic vinyl monomer, and the aromatic vinyl monomer is styrene, α-methylstyrene, α-ethylstyrene, p-methylstyrene, o-methylstyrene, o-t -It may be one or more selected from the group consisting of butylstyrene, bromostyrene, chlorostyrene, trichlorostyrene, and their derivatives, and a specific example may be styrene.

The aromatic vinyl monomer may be added in an amount of 5 to 50 parts by weight, 10 to 40 parts by weight, or 10 to 30 parts by weight, based on 100 parts by weight of the total monomer input, and within this range, a high polymerization conversion rate is achieved. A copolymer can be obtained, and while maintaining the mechanical properties of the copolymer, it can function in controlling the glass transition temperature and has the effect of improving compatibility with thermoplastic resins.

In addition, according to an embodiment of the present invention, the production method may be a suspension polymerization method, wherein the reaction solution contains, in addition to monomers such as alkyl (meth)acrylate monomers and aromatic vinyl monomers, a polymerization initiator, It may further include one or more polymerization additives such as a dispersant, dispersion aid, or molecular weight regulator, and may further include a polymerization solvent.

According to one embodiment of the present invention, the polymerization initiator is used to easily initiate polymerization and is not particularly limited as long as it does not adversely affect polymerization, for example, 2,5-dimethyl-2,5-di(t- Butylperoxy)hexane, di(t-butylperoxy-isopropyl)benzene, t-butyl cumyl peroxide, di-(t-amyl)-peroxide, dicumyl peroxide, butyl 4,4-di(t -Butylperoxy)valerate, t-butylperoxybenzoate, 2,2-di(t-butylperoxy)butane, t-amyl peroxy-benzoate, t-butylperoxy-acetate, t-butyl Peroxy-(2-ethylhexyl)carbonate, t-butylperoxy isopropyl carbonate, t-butyl peroxy-3,5,5-trimethyl-hexanoate, 1,1-di(t-butylperoxy) Cyclohexane, t-amyl peroxyacetate, t-amylperoxy-(2-ethylhexyl)carbonate, 1,1-di(t-butylperoxy)-3,5,5-trimethylcyclohexane, 1,1 -di(t-amylperoxy)cyclohexane, t-butyl-monoperoxy-maleate, 1,1'-azodi(hexahydrobenzonitrile) and 1,1'-azobis(cyclohexane-1- cyclonitrile), and specifically, dicumyl peroxide, 1,1-di(t-butyl peroxy)cyclohexane, and 1,1'-azobis(cyclohexane carbonitrile). ) may be one or more types selected from the group consisting of

In addition, the polymerization initiator may be used in an amount of 0.001 to 0.5 parts by weight, specifically 0.003 to 0.45 parts by weight or 0.06 to 0.25 parts by weight, based on 100 parts by weight of the total amount of monomers used in polymerization. When used within this range, the polymerization reaction can be carried out more easily and the polymerization conversion rate can be increased.

According to one embodiment of the present invention, the dispersant is an additive that allows the suspension to be better dispersed in a solvent in suspension polymerization, for example, water-soluble polyvinyl alcohol, partially saponified polyvinyl alcohol, and polyacrylic acid. , copolymer of vinyl acetate and maleic anhydride, hydroxypropyl methylcellulose, gelatin, calcium phosphate, tricalcium phosphate, hydroxyapatite, sorbitan monolaurate, sorbitan trioleate, polyoxyethylene, sodium lauryl sulfate, It may be one or more selected from the group consisting of sodium dodecylbenzenesulfonate and sodium dioctylsulfosuccinate, and a specific example may be tricalcium phosphate, and may be the same as the dispersant added before the start of polymerization.

The dispersant may be used in an amount of 0.5 to 2.0 parts by weight, 0.5 to 1.5 parts by weight, or 1.0 to 1.5 parts by weight based on 100 parts by weight of the total monomer input, and within this range, the dispersion stability of the monomers in the polymerization system By increasing , a copolymer with more uniform particles can be manufactured.

In addition, according to one embodiment of the present invention, the reaction solution may further include a dispersion aid. As a specific example, the dispersion aid may be polyoxyethylene alkyl ether phosphate or sodium sulfate (Na ₂ SO ₄ ), and more. Specifically, it may be sodium sulfate, in which case it has excellent polymerization stability.

According to one embodiment of the present invention, the molecular weight regulator is, for example, α-methylstyrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, octyl mercaptan, carbon tetrachloride, methylene chloride, methylene bromide, tetrachloride It may be one or more selected from the group consisting of ethyl thiuram disulfide, dipentamethylene thiuram disulfide, and diisopropyl xanthogen disulfide, and a specific example may be t-dodecyl mercaptan.

The molecular weight regulator may be used in an amount of 0.01 to 0.40 parts by weight, 0.05 to 0.30 parts by weight, or 0.10 to 0.25 parts by weight based on 100 parts by weight of the total monomer input, and the copolymer has an appropriate weight average molecular weight within this range. can be manufactured.

According to one embodiment of the present invention, the above production method may be carried out in the presence of a water-soluble solvent as a solvent for polymerization.

According to one embodiment of the present invention, the water-soluble solvent may be ion-exchanged water or deionized water. Meanwhile, according to one embodiment of the present invention, the monomer droplet may contain a water-soluble solvent. In this case, the water-soluble solvent may be ion-exchanged water or deionized water, and the water-soluble solvent introduced before the start of polymerization It may be the same.

According to one embodiment of the present invention, an additional monomer may be further included to prepare a quaternary copolymer, and the additional monomer may be a vinyl cyanide monomer, which is further included in the reaction solution to produce the ( Step S1) may be performed. The vinyl cyanide monomer may be one or more selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, and derivatives thereof, and a specific example may be acrylonitrile.

The vinyl cyanide monomer may be added in an amount of 5 to 70 parts by weight, 10 to 60 parts by weight, 15 to 50 parts by weight, or 15 to 40 parts by weight, based on the total monomer content. Within this range, a copolymer can be obtained with a high polymerization conversion rate, and while maintaining the mechanical properties of the copolymer, it has excellent compatibility with thermoplastic resins.

According to one embodiment of the present invention, the (S2) step is performed immediately after the (S1) step, and the (S2) step is a step of polymerizing a monomer solution containing an imide monomer while continuously introducing it into the reactor, This is the step of continuously adding the monomer solution from the step (S1) until the polymerization conversion rate is 50% to 70%.

According to one embodiment of the present invention, the monomer solution includes an imide-based monomer. Imide-based monomers have high reactivity, so they are easier to be incorporated into the copolymer chain than other monomers such as alkyl (meth)acrylate-based monomers and aromatic vinyl-based monomers. If this is not properly controlled, physical properties may deteriorate due to compositional imbalance between copolymer chains. Problems may arise. Accordingly, the present invention is characterized in that the monomer solution containing the imide-based monomer is not added while the internal temperature of the reactor is raised, but is added during polymerization after increasing the reactivity of other monomers by increasing the temperature.

The imide-based monomer begins to be added immediately after step (S1) and is continuously added until the polymerization conversion rate is 50% to 70%. Here, continuous injection may mean that a certain amount is introduced for a certain period of time at a constant rate, and the monomer solution may be introduced into the reactor at a constant flow rate. Here, there are no limitations to the method as long as the monomer solution can be continuously supplied to the reactor at a constant flow rate (or speed).

According to one embodiment of the present invention, the continuous addition of the monomer solution in the (S2) step begins immediately after the (S1) step and ends when the polymerization conversion rate is 50% to 70%, which is referred to immediately after the (S1) step. This may mean after the internal temperature of the reactor is raised to a predetermined temperature, and in another sense, it may be at a level before the polymerization conversion rate reaches about 10%, as described above, and preferably before it reaches 5%. It may mean a point in time.

In addition, at the end point, if continuous input continues until the polymerization conversion rate exceeds 70%, the imide-based monomers added thereafter may not participate in the polymerization, causing problems of compositional imbalance between chains and an increase in residual monomer content. may occur, and the resulting problem of lowering the glass transition temperature may occur. In addition, if the continuous input is terminated early at a point lower than the polymerization conversion rate of 50%, the problem of composition imbalance between chains may also occur due to excessive mixing of imide-based monomers in the initially prepared copolymer chain. Accordingly, the continuous addition of the monomer solution is preferably terminated when the polymerization conversion rate is 50% to 70%, and preferably may be terminated when the polymerization conversion rate is 55% to 65%.

According to one embodiment of the present invention, the monomer solution includes an imide-based monomer, and the imide-based monomer may be a maleimide-based monomer. As a specific example, the hydrogen bonded to the N atom of the maleimide is substituted with a substituent. It may be a maleimide monomer. As a more specific example, the imide monomer is N-methyl maleimide, N-ethyl maleimide, N-propyl maleimide, N-isopropyl maleimide, N-butyl maleimide, N-isobutyl maleimide, N-t-butyl Maleimide, N-cyclohexyl maleimide, N-chlorophenyl maleimide, N-methylphenyl maleimide, N-bromophenyl maleimide, N-lauryl maleimide, N-hydroxyphenyl maleimide, N-meth Toxyphenyl maleimide, N-carboxyphenyl maleimide, N-nitrophenyl maleimide, N-phenyl maleimide, 2-methyl-N-phenyl maleimide, N-benzyl maleimide, N-naphthyl maleimide and these It may be one or more types selected from the group consisting of derivatives, and a specific example may be N-phenylmaleimide.

The imide-based monomer is 1 part by weight to 20 parts by weight, 3 parts by weight to 15 parts by weight, or 4 parts by weight to 10 parts by weight, based on the total monomer content added during the steps (S1) and (S2). It can be added in parts, and within this range, a copolymer can be obtained with a high polymerization conversion rate, it is possible to produce a copolymer with a uniform composition of monomer units, and the produced copolymer has excellent heat resistance.

In addition, according to one embodiment of the present invention, the monomer solution continuously added to step (S2) may further include one or more polymerization additives among a polymerization initiator, a dispersant, and a molecular weight regulator. If such a polymerization additive is further included, the effect of adding the imide monomer separately after the start of polymerization can be further maximized, and greater benefits can be obtained in controlling monomer reactivity or balancing the composition between chains. .

Meanwhile, according to one embodiment of the present invention, after continuous addition of the monomer solution in step (S2), polymerization is performed through temperature control such as raising the temperature to a predetermined temperature, maintaining the temperature at the predetermined temperature, increasing the temperature back to the predetermined temperature, or lowering the temperature. It can be. In this case, polymerization may be carried out at a temperature range of 50°C to 150°C by raising, lowering, or leaving the temperature still, preferably at a temperature of 60°C to 130°C and more preferably at a temperature of 65°C to 120°C. When polymerization is performed in this temperature range, a high final polymerization conversion rate can be achieved, the composition between copolymer chains can be uniform, and this can be desirable for obtaining a copolymer with a desired level of physical properties.

Thermoplastic resin composition

The resin composition according to the present invention includes the above-described acrylic-imide-based copolymer. The resin composition can be applied by mixing various resins depending on the desired use, for example, acrylonitrile-butadiene-styrene-based resin, acrylonitrile-styrene-acrylate-based resin, and styrene-acrylonitrile-based resin. etc. can be used together, and a resin in which an alkyl (meth)acrylate monomer or a maleimide monomer is copolymerized with the above resin can be used, but is not particularly limited thereto.

In addition, according to one embodiment of the present invention, the resin composition may optionally contain one selected from the group consisting of impact modifiers, lubricants, heat stabilizers, anti-dripping agents, antioxidants, light stabilizers, ultraviolet ray blockers, pigments, and inorganic fillers. It may further include more than one type of additive, and in this case, the additive may be used in an amount of 5.0 parts by weight or less, or 0.1 to 1.0 part by weight, based on 100 parts by weight of the copolymer and thermoplastic resin.

In addition, the specific material of the additive may be used without particular limitation as long as it is used in the resin composition. For example, the anti-dripping agent may include Teflon, polyamide, polysilicon, PTFE (polytetrafluoroethylene), and TFE-HFP ( At least one selected from the group consisting of tetrafluoroethylene-hexafluoropropylene) copolymer may be used, and the inorganic filler may include at least one selected from the group consisting of barium sulfate, barium glass filler, and barium oxide.

molded product

According to the present invention, a molded article containing the above-described resin composition is provided. For example, the molded product can be applied to various industrial fields such as various electrical and electronic products and automobile parts. As a molding method, general molding methods such as extrusion, injection, and casting can be applied. For example, in injection molding, compared to a product intended to provide a matte molded product by corroding the surface of the mold, the molded product according to the present invention has a surface of the mold. There is no need for corrosion treatment, and even without post-treatment on the molded product, it is possible to provide a molded product with a matte yet uniform surface in the injection molded state.

Example

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement it. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

Example 1

150 parts by weight of ion-exchanged water, 75 parts by weight of methyl methacrylate, 20 parts by weight of styrene, 0.06 parts by weight of 1,1-di(t-butylperoxy)cyclohexane as a polymerization initiator, and a weight average molecular weight of approximately 1,850,000 as a dispersant. 0.05 part by weight of g/mol copolymer (copolymerization of acrylic acid and 2-ethylhexyl acrylate), 0.5 part by weight of t-dodecyl mercaptan (TDM) as a molecular weight regulator, and 0.5 part by weight of dispersion aid (Na ₂ SO ₄ ) uniformly A reaction solution was prepared by mixing, which was put into the reactor and the temperature inside the reactor was raised to 100°C to initiate polymerization. From the time the temperature inside the reactor reached 100°C, 5 parts by weight of N-phenyl maleimide was continuously added at a constant rate, maintaining a rate of about 1.67 parts by weight/hr until the polymerization conversion rate was 50%. After terminating the continuous addition of the N-phenyl maleimide, polymerization was performed for an additional 60 minutes while the temperature of the reactor was maintained at 100°C, and the temperature of the reactor was raised to 120°C at a constant rate for 30 minutes and then cooled to 120°C. While maintained, polymerization was further continued for 90 minutes to complete the polymerization. The polymerization slurry upon completion of polymerization was washed with water, dehydrated, and dried to prepare a bead-shaped copolymer.

Here, each part by weight is based on 100 parts by weight of the total monomer input.

Example 2

A crosslinked copolymer was prepared in the same manner as in Example 1, except that 5 parts by weight of N-phenyl maleimide was continuously added at a rate of about 1.25 parts by weight/hr until the polymerization conversion rate was about 70%. .

Example 3

A crosslinked copolymer was prepared in the same manner as in Example 1, except that 5 parts by weight of N-phenyl maleimide was continuously added at a rate of about 2.5 parts by weight/hr until the polymerization conversion rate was about 50%. .

Example 4

76 parts by weight of methyl methacrylate and 16 parts by weight of styrene were added to the reaction solution initially introduced into the reactor, and 8 parts by weight of N-phenyl maleimide were added at a rate of about 2.67 parts by weight/hr until the polymerization conversion rate was about 65%. A crosslinked copolymer was prepared in the same manner as in Example 1, except that it was added continuously.

Example 5

76 parts by weight of methyl methacrylate and 11 parts by weight of styrene were added to the reaction solution initially introduced into the reactor, and 13 parts by weight of N-phenyl maleimide were added at a rate of about 5.20 parts by weight/hr until the polymerization conversion rate was about 65%. A crosslinked copolymer was prepared in the same manner as in Example 1, except that it was added continuously.

Comparative Example 1

A copolymer was prepared in the same manner as in Example 1, except that 100 parts by weight of methyl methacrylate was added as the monomer to the reaction solution, and the monomer solution was not added during polymerization.

Comparative Example 2

A copolymer was prepared in the same manner as in Example 1, except that 75 parts by weight of methyl methacrylate and 25 parts by weight of styrene were added as monomers to the reaction solution, and the monomer solution was not added during polymerization.

Comparative Example 3

75 parts by weight of methyl methacrylate, 20 parts by weight of styrene, and 5 parts by weight of N-phenyl maleimide were added as monomers to the reaction solution, and the monomer solution was added to the reaction solution in the same manner as in Example 1, except that the monomer solution was not added during polymerization. A composite was prepared.

Comparative Example 4

75 parts by weight of methyl methacrylate, 4 parts by weight of styrene, and 21 parts by weight of N-phenyl maleimide were added as monomers to the reaction solution, and the monomer solution was added to the reaction solution in the same manner as in Example 1, except that the monomer solution was not added during polymerization. A composite was prepared.

Comparative Example 5

150 parts by weight of ion-exchanged water, 75 parts by weight of methyl methacrylate, 20 parts by weight of styrene, 0.06 parts by weight of 1,1-di(t-butylperoxy)cyclohexane as a polymerization initiator, and a weight average molecular weight of approximately 1,850,000 as a dispersant. 0.05 part by weight of g/mol copolymer (copolymerization of acrylic acid and 2-ethylhexyl acrylate), 0.5 part by weight of t-dodecyl mercaptan (TDM) as a molecular weight regulator, and 0.5 part by weight of dispersion aid (Na ₂ SO ₄ ) uniformly A reaction solution was prepared by mixing, which was put into the reactor and the temperature inside the reactor was raised to 100°C to initiate polymerization. From the time the temperature inside the reactor reached 100°C, 5 parts by weight of N-phenyl maleimide was continuously added at a constant rate, maintaining a rate of about 1.67 parts by weight/hr until the polymerization conversion rate was 50%. After terminating the continuous addition of the N-phenyl maleimide, polymerization was performed for an additional 60 minutes while the temperature of the reactor was maintained at 100°C, and the temperature of the reactor was raised to 120°C at a constant rate for 30 minutes, and then the polymerization conversion rate was determined. Polymerization was terminated at 90%. The polymerization slurry upon completion of polymerization was washed with water, dehydrated, and dried to prepare a bead-shaped copolymer.

Comparative Example 6

150 parts by weight of ion-exchanged water, 75 parts by weight of methyl methacrylate, 20 parts by weight of styrene, 0.06 parts by weight of 1,1-di(t-butylperoxy)cyclohexane as a polymerization initiator, and a weight average molecular weight of approximately 1,850,000 as a dispersant. 0.05 part by weight of g/mol copolymer (copolymerization of acrylic acid and 2-ethylhexyl acrylate), 0.5 part by weight of t-dodecyl mercaptan (TDM) as a molecular weight regulator, and 0.5 part by weight of dispersion aid (Na ₂ SO ₄ ) uniformly A reaction solution was prepared by mixing, which was put into the reactor and the temperature inside the reactor was raised to 100°C to initiate polymerization. From the time the temperature inside the reactor reached 100°C, 5 parts by weight of N-phenyl maleimide was continuously added at a constant rate, maintaining a rate of about 1.67 parts by weight/hr until the polymerization conversion rate was 50%. After the continuous addition of N-phenyl maleimide was completed, polymerization was continued for an additional 4 hours while the temperature of the reactor was maintained at 100°C, and the polymerization was terminated when the polymerization conversion rate was 90%. The polymerization slurry upon completion of polymerization was washed with water, dehydrated, and dried to prepare a bead-shaped copolymer.

Experimental Example 1

For the copolymers prepared in Examples 1 to 5 and Comparative Examples 1 to 3, the glass transition temperature, residual monomer content, and transparency were measured by the following methods, and the results are listed in Table 1 below.

(1) Glass transition temperature (Tg, ℃): After collecting a 0.01 g sample from the polymer and copolymer, use a differential scanning calorimeter (DSC, METTLER TOLEDO) at room temperature (20℃ to 25℃). After first heating from ℃ to 180℃ to remove foreign substances, cooling to room temperature (20℃ to 25℃), and then heating again to 180℃ for the second time to measure the glass transition temperature.

(2) Composition deviation: Samples are collected from the copolymer at the start of polymerization and when the polymerization conversion rate is about 20%, 40%, 60%, and 80% after the start of polymerization, and then dissolved in tetrahydrofuran (THF). After inducing precipitation of solids by adding methanol, the supernatant was removed from the precipitate, and the content of imide monomer (N-phenyl maleimide) units in the copolymer was determined through Elements Analysis (Flash 2000) under the following measurement conditions. was measured, and the standard deviation was obtained from the measured values.

- N analysis: reactor temperature 900℃, oven temperature 65℃, He carrier gas flow rate 140 mL/min, He reference gas flow rate 100 mL/min, O ₂ flow rate 250 mL/min, O ₂ injection time 5 seconds, Sample delay 12 seconds, total run time 720 seconds

- O analysis: reactor temperature 1060℃, oven temperature 65℃, He carrier gas flow rate 100 mL/min, He reference gas flow rate 100 mL/min, O ₂ flow off, O2 injection time 0 seconds, sample delay 0 seconds, Total run time 500 seconds

(3) Residual monomer content (% by weight): After polymerization, the bead-shaped copolymer was dissolved in chloroform, then methanol was added to precipitate the polymer resin, and some of the supernatant in which the residual monomer was dissolved was taken as a sample, and then used as a sample by Agilent. Using the company's gas chromatography device (Agilent 6890N (GC-FID)), the content of residual monomer was calculated under the following measurement conditions.

- Inlet: 280℃ carrier gas He, split ratio 10:1

- Column: HP-5 capillary column

- Flow rate: 1.4 mL/min

- Oven: Isothermal at 100℃ for 3 minutes, heated to 300℃ at a rate of 10℃/min, isothermal at 300℃ for 5 minutes

- Detector: FID, 250℃

(4) Transparency: The total light transmittance (Tt) of the manufactured copolymer was measured using a Haze Meter, and if the total light transmittance was 90 or more, it was marked as ○, if it was less than 90, it was marked as X.

residual monomer
(weight%) composition deviation Tg
(℃) [(Tg)-100]/[W _I ] Transparency (Tt) Example 1 0.6 0.44 115.7 3.14 ○ Example 2 0.8 0.39 114.5 2.90 ○ Example 3 1.0 0.64 114.8 2.96 ○ Example 4 0.7 0.93 124.6 3.08 ○ Example 5 0.8 1.42 132.1 2.47 ○ Comparative Example 1 0.5 - 105.2 - ○ Comparative Example 2 0.9 - 108.4 - X Comparative Example 3 1.4 4.23 113.2 2.64 X Comparative Example 4 1.8 4.40 137.9 1.90 X Comparative Example 5 8.9 3.6 125.6 5.12 X Comparative Example 6 21.8 4.7 122.1 4.42 X

As can be seen in Table 1, when the method for producing the copolymer according to the present invention was applied, there was almost no compositional deviation, the residual monomer content was low at 1.0% by weight or less, and the glass transition temperature was low compared to the imide monomer content. It was confirmed that it was appropriately shown, had excellent heat resistance, and was excellent in efficiency by realizing the optimal glass transition temperature through the optimal imide monomer, and it was also confirmed that transparency could be secured.

On the other hand, in Comparative Examples 1 and 2, the imide-based monomer was not applied and the residual monomer content was low, but it can be seen that the heat resistance was not secured due to the low glass transition temperature. In addition, Comparative Example 3, in which the imide-based monomer was added but not added during polymerization, had a lower glass transition temperature compared to the examples in which the same amount was added, the residual monomer content exceeded 1.0% by weight, and furthermore, an opaque copolymer was produced. You can check it. In addition, in Comparative Example 4, an attempt was made to increase the glass transition temperature by adding an excessive amount of imide-based monomer, but in this case, a problem with transparency occurred, and it can be confirmed that the deviation between monomer compositions became severe due to non-application of the addition method.

In addition, in Comparative Examples 5 and 6, the [(Tg)-100]/[W _I ] value exceeded 4.2, confirming that problems with transparency occurred and the variation between compositions became severe.

Through this, it can be confirmed that in cases where the production method of the present invention is not used, problems such as worsening compositional deviation or worsening transparency occur even if the glass transition temperature is achieved by increasing the content of the imide monomer.

Claims (9)

Alkyl (meth)acrylate-based monomer unit; Aromatic vinyl monomer unit; and an imide-based monomer unit, comprising a plurality of copolymer chains,
The glass transition temperature is 109°C to 133°C,
The imide-based monomer unit is contained in an amount of 20 parts by weight or less based on 100 parts by weight of the total copolymer,
An acrylic-imide-based copolymer in which the residual monomer content in the copolymer is 1.3% by weight or less. According to paragraph 1,
The copolymer has a glass transition temperature of 111°C to 128°C. According to paragraph 1,
A copolymer wherein the residual monomer content in the copolymer is 1.0% by weight or less. According to paragraph 1,
The copolymer further includes vinyl cyanide monomer units. According to paragraph 1,
For 100 parts by weight of the above copolymer,
40 to 90 parts by weight of the alkyl (meth)acrylate monomer unit;
5 to 50 parts by weight of the aromatic vinyl monomer unit; and
A copolymer comprising 1 to 20 parts by weight of the imide monomer unit. Alkyl (meth)acrylate-based monomer unit; Aromatic vinyl monomer unit; and an imide-based monomer unit, comprising a plurality of copolymer chains,
The copolymer is an acrylic-based copolymer in which the glass transition temperature and the content of the imide monomer unit satisfy the following equation 1 when the alkyl (meth)acrylate monomer unit is 45 parts by weight or more based on 100 parts by weight of the total copolymer. Imide-based copolymer:
[Equation 1]
2.0 ≤[(Tg)-100]/[W _I ] ≤4.2
Here, Tg is the unitless number of the glass transition temperature when the unit is ℃, and W _I is the imide monomer unit for 100 parts by weight (or weight %) of the total copolymer when the unit is parts by weight (or weight %). It is an infinite number of contents. According to clause 6,
A copolymer wherein the composition deviation between the plurality of copolymer chains is 3.50 or less. According to clause 6,
The copolymer has a glass transition temperature of 109°C to 133°C. A thermoplastic resin composition comprising the acrylic-imide-based copolymer of claim 1 or 6 and a thermoplastic resin.