KR20090054628A - Methacrylate-styrene-perfluoroacrylate terpolymer having high contact angle and method of preparing the same - Google Patents

Abstract

A methacrylate-styrene-perfluoroacrylate terpolymer is provided to improve surface contamination while maintaining transparency and to solve problems on degradation of transparency and coating defective, low reusability and use of an organic agent for coating. A methacrylate-styrene-perfluoroacrylate terpolymer comprises methacrylate component 60-97 weight%, and styrene compound component and perfluorinated acrylate component 3-40 weight%. The styrene compound component and perfluorinated acrylate component has a weight ratio of 55/45 - 60/40. A method for the methacrylate-styrene-perfluoroacrylate terpolymer comprises the steps of: injecting an initiator and a molecular weight modifier in a monomer mixture of methacrylate monomer, styrene monomer and perfluorinated acrylate; and perfluorinated acrylate the monomer mixture in aqueous dispersion and polymerizing them at 70-120 °C for 2-8 hours.

Description

Methacrylate-Styrene-Perfluoroacrylate Terpolymer Having High Contact Angle and Method of Preparing the Same}

Field of invention

The present invention relates to a methacrylate-styrene-based compound-perfluorinated acrylate terpolymer having a high contact angle characteristic and a method for producing the same. More specifically, the present invention relates to a methacrylate-styrene compound-perfluorinated acrylate terpolymer obtained by introducing perfluoro acrylate to improve surface contamination.

Background of the Invention

In general, methacryl-based resins have excellent scratch resistance due to sufficient stiffness, high transmittance and excellent stiffness, and have been applied in various fields due to these characteristics. Injection products of methacrylic resins are used for taillights, instrument panel covers, eyeglass lenses, etc. of automobiles, and extruded products are used for signboards and various sheet products.

On the other hand, methacryl-based resins have excellent scratch resistance due to their excellent stiffness, but have the disadvantage of deteriorating rubbing characteristics such as soft scratches and fine scratches caused by repeated rubbing of towels, and surface adhesion of static electricity and contaminants. Surface contamination by is easy to occur.

In order to solve the above problems, conventionally, a technology for expressing antistatic properties by introducing an antistatic agent has been developed. However, when an excessive amount of the antistatic agent is used, there is a problem in that the transparency is lowered and staining due to the antistatic agent protruding to the surface occurs.

Accordingly, when using methacryl-based resin, in order to improve the surface contamination, it is usually used to coat the surface. However, due to the addition of the coating process, there is a hassle of increasing the processing steps, a problem caused by the organic solvent in the coating process, and also the occurrence of defects uneven coating during coating and difficult to recycle after the coating process Has problems such as;

Efforts have been made to improve surface contamination by copolymerizing the perfluorine compound used in the coating in the preparation of methacrylate resins. However, there has been a problem in that the perfluorinated compound having a relatively long CF chain length is not easily copolymerized and has a fatal disadvantage that the transparency of the methacrylate resin is poor.

In order to solve the above problems, the present inventors introduced styrene-based compounds and perfluorinated acrylates during the methacrylate polymerization, thereby reducing the surface energy of the methacryl-based resin while maintaining transparency of the methacryl-based resin, thereby greatly reducing surface contamination. An improved methacrylate-styrene compound-perfluorinated acrylate terpolymer and a method of preparing the same have been developed.

An object of the present invention is to provide a methacrylate-styrene-based perfluoro acrylate terpolymer with improved surface contamination while maintaining the refractive index of the methacryl resin, that is, transparency.

Another object of the present invention is to provide a methacrylate-styrene compound-perfluoro acrylate terpolymer having excellent surface contamination by increasing the contact angle with respect to both water and oil.

Another object of the present invention is a methacrylate-styrene-based compound-perfluorine, which is free from problems of transparency and surface coating due to the use of an antistatic agent, i.e., poor coating, low recyclability, and a problem with an organic agent for coating. It is to provide an acrylate terpolymer.

Still another object of the present invention is to provide a methacryl resin having improved surface contamination and no decrease in transparency even by a general injection molding process.

Still another object of the present invention is to provide a method for preparing the methacrylate-styrene-based perfluoro acrylate terpolymer by dispersion polymerization.

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

Summary of the Invention

The present invention provides a methacrylate-styrene-based compound-perfluoro acrylate terpolymer. The methacrylate-styrene compound-perfluoro acrylate terpolymer is 60 to 97% by weight of the methacrylate component; And 3 to 40% by weight of the styrene-based compound component and the perfluorinated acrylate component, and the styrene-based compound component and the perfluorinated acrylate component are characterized by a weight ratio of 55/45 to 60/40.

The present invention provides a methacryl resin prepared by a general injection molding method using the copolymer. The methacryl resin has an increase in contact angle with respect to both water and oil, thereby improving surface contamination.

The invention also provides a process for the preparation of methacrylate-styrene-based compound-perfluoro acrylate terpolymers. The method includes preparing a monomer mixture by introducing an initiator and a molecular weight regulator into a monomer mixture obtained by mixing a methacrylate monomer, a styrene monomer and a perfluorinated acrylate monomer; And the monomer mixture is added to an aqueous dispersion and consists of a step of dispersion polymerization for 2 to 8 hours at 70 to 120 ℃.

Detailed Description of the Invention

The methacrylate-styrene compound-perfluoro acrylate terpolymer of the present invention comprises 60 to 97% by weight of the methacrylate component and 3 to 40% by weight of the styrene-based compound component and the perfluorine acrylate component. The system compound component and the perfluorine acrylate component is characterized in that the weight ratio of 55/45 to 60/40.

As the methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and the like may be used, and these may be applied alone or in mixture. The use of double methyl methacrylate is most preferred in terms of refractive index.

The perfluorinated acrylate has a different polymerization method according to the length of the main CF chain, and the effect of lowering the surface energy varies depending on the length of the main CF chain. As the main CF chain length increases, the effect of lowering the surface energy when the same content is added increases, but the colorability is lowered, thereby causing a problem in that a pearl-shaped pattern is generated.

In the present invention, a perfluorinated acrylate monomer having a main CF chain length of 4 to 8 is used. When the main CF chain length uses perfluorinated acrylate in the above range, the surface energy can be lowered without deterioration of colorability.

As the perfluorine acrylate, perfluorobutylethyl methacrylate, perfluoropentylethyl methacrylate, perfluorohexylethyl methacrylate, perfluoroheptylethyl methacrylate, perfluorooctylethyl methacrylate Rates and the like can be used, and they can be applied alone or in mixture.

Preferably perfluorooctylethylmethacylate (hereinafter referred to as perfluoromonomer) having a main CF average chain length of 8.

Since the refractive index of perfluorinated acrylate is very low and there is a limit of use due to the difference in refractive index with the existing polymethyl methacrylate resin when copolymerizing with polymethyl methacrylate, the refractive index with polymethyl methacrylate which is widely used In the same manner, ternary copolymerization with a styrene monomer having a relatively high refractive index is performed.

Styrene, α-methyl styrene, α-ethyl styrene, o-t-butyl styrene and the like may be used as the styrene-based compound, these may be applied alone or in a mixture. Double styrene may be most preferably applied.

In the present invention, by lowering the surface energy of the methacryl resin by using the styrene-based compound and perfluorinated acrylate, the surface contamination property is improved and the refractive index of the methacryl resin can be maintained without using an antistatic agent and a surface coating.

The methacrylate component in the methacrylate-styrene compound-perfluoro acrylate terpolymer of the present invention is preferably 60 to 97% by weight. If the methacrylate component is less than 60% by weight, it is difficult to form a single phase with the perfluorinated acrylate and the styrene-based compound, a homopolymer of perfluorinated acrylate is formed during polymerization, and the transparency is lowered, and the pearl may be affected by the difference in refractive index. Blur of the pattern may occur. On the other hand, if the content of more than 97% by weight of the perfluorinated acrylate is extremely small, the perfluorine groups oriented to the surface is very small, the effect of lowering the surface energy is insufficient.

It is preferable that the styrene-based compound component and the perfluorinated acrylate component have a weight ratio of 55/45 to 60/40 to control the refractive index. More preferably, ratio 57 / 43-58 / 42 of a styrene type compound and a perfluoro acrylate is preferable for expressing transparency. If it is out of the above ratio, a fourth other monomer is required to make the same refractive index with the polymethacrylate.

The methacrylate-styrene compound-perfluoro acrylate terpolymer of the present invention can be polymerized by bulk polymerization, dispersion polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like. Preferably, in order to secure transparency in the methacryl resin, dispersion polymerization is performed by adjusting the composition of the perfluorinated acrylate and the styrene monomer so that the refractive index can be adjusted within ± 0.005 based on the refractive index of 1.49 of the polymethyl methacrylate resin. .

In one embodiment of the present invention, a monomer mixture is prepared by introducing an initiator and a molecular weight regulator into a monomer mixture in which a methacrylate monomer, a styrene monomer and a perfluoro acrylate monomer are mixed; And the monomer mixture is added to an aqueous dispersion and consists of a step of dispersion polymerization for 2 to 8 hours at 70 to 120 ℃.

It is preferable that the said initiator uses a peroxide type fat-soluble initiator. For example, octanoyl peroxide, decanyl peroxide, lauroyl peroxide, benzoyl peroxide, monochlorobenzoyl peroxide, dichlorobenzoyl peroxide, p-methylbenzoyl peroxide, tert-butyl perbenzoate, azobisiso Butyronitrile, azobis- (2,4-dimethyl) -valeronitrile, etc. are mentioned. The initiator is preferably used in 0.3 parts by weight to 1 part by weight based on 100 parts by weight of the monomer mixture. When the content of the initiator is 0.3 parts by weight or less, the reactivity is very slow due to the polymerization inhibitor and impurities remaining in the monomer, and when the content is 1.0 parts by weight or more, the reactivity is very good, but deterioration of physical properties due to heat removal problems and a decrease in molecular weight occurs.

The molecular weight modifier is CH ₃ ((CH ₂ ) _n SH form such as n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tertiary dodecyl mercaptan, isopropyl mercaptan, n-amyl mercaptan It is preferably selected from the group consisting of halogen compounds such as alkylmercaptan and carbon tetrachloride, and aromatic compounds of alpha methylstyrene dimer and alpha ethylstyrene dimer Although the amount of the molecular weight modifier varies depending on the type, the monomer mixture 100 It is preferably 0.02 to 10 parts by weight with respect to parts by weight, if it is used at 0.01 parts by weight or less, the heat resistance is poor due to the thermal decomposition phenomenon, and when it is 10 parts by weight or more, the molecular weight of the polymer is too low and the mechanical properties are very poor.

The dispersant may be inorganic or organic, which is a conventional dispersant. However, in the case of the inorganic dispersant, an organic dispersant is preferable to an inorganic dispersant because an inorganic dispersant requires a step of removing the dispersant and affects physical properties such as transparency due to the remaining inorganic dispersant. More preferred are acrylate copolymers. In the present invention, a copolymer of acrylate acrylic acid or acrylate methacrylic acid can be applied as a dispersant. The copolymer dispersant should have an acrylic acid or methacrylic acid content of at least 30 parts by weight of the polymer. They are also preferably in the form of salts of sodium, potassium or ammonium. This is a characteristic required to maintain proper solubility between water as a dispersion medium and the monomer suspended. The dispersant is appropriately 0.002 to 0.2 parts by weight based on 100 parts by weight of the monomer mixture, the specific content is slightly different depending on the component and molecular weight of the dispersant.

In addition, a small amount of electrolyte is used to improve stability. The electrolyte used is to control the solubility characteristics of disodium hydrogen phosphate, sodium dihydrogen phosphate, or potassium or sodium carbamate, water-soluble polymers or monomers, which are phosphate or sulfuric acid buffer salts for pH control. Sodium sulfate may also be added.

The dispersion polymerization of the present invention is carried out according to a conventional dispersion polymerization method. For example, the polymerization is completed by reacting for about 2 to 8 hours at a polymerization temperature of 70 to 120 ° C. in the presence of a chain transfer agent and an initiator.

After the polymerization is completed, it is possible to obtain a polymer in the form of beads through cooling, washing, dehydration, drying process.

The present invention can provide a methacryl resin by injection molding the methacrylate-styrene compound-perfluoro acrylate terpolymer in a conventional manner. The methacryl resin has an increase in contact angle with respect to both water and oil, thereby improving surface contamination.

The invention will be further illustrated by the following examples, which are intended to illustrate the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Example 1

70 parts by weight of methyl methacrylate, 17.36 parts by weight of styrene monomer, 12.64 parts by weight of perfluoromonomer, 0.3 parts by weight of lauroyl peroxide, and 0.5 parts by weight of normal-octylmercaptan were mixed well so that the monomer mixture was completely uniform. 200 parts by weight of ion-exchanged water, 0.3 parts by weight of an organic dispersant (methacrylate methacrylate copolymer) and 2.0 parts by weight of potassium carbamate were dissolved in a glass reactor equipped with a stirrer. The monomer mixture liquid uniformly mixed was put into the glass reactor, and the reactor was sealed. The reactor was stirred at 300 rpm using a mechanical stirrer, and the inside of the reactor was purged with nitrogen. The reactor temperature was polymerized at 75 ° C. for 4 hours, and then heated to 95 ° C. for 1 hour. After the polymerization was completed, the polymer was filtered through a 200 mesh filter to obtain a polymer through washing, dehydration and drying. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

Example 2

The polymerization product was obtained in the same manner as in Example 1 except that the monomer mixture composition was changed to 80 parts by weight of methyl methacrylate, 11.57 parts by weight of styrene monomer, and 8.43 parts by weight of perfluoromonomer. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

Example 3

The polymerization product was obtained in the same manner as in Example 1 except that the monomer mixture composition was changed to 90 parts by weight of methyl methacrylate, 5.79 parts by weight of styrene monomer, and 4.21 parts by weight of perfluoromonomer. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

Example 4

Polymerization was obtained in the same manner as in Example 1 except that the monomer mixture composition was changed to 95 parts by weight of methyl methacrylate, 2.89 parts by weight of styrene monomer, and 2.11 parts by weight of perfluorinated monomer. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

Example 5

Polymerization was obtained in the same manner as in Example 1 except that the monomer mixture composition was changed to 97 parts by weight of methyl methacrylate, 1.736 parts by weight of styrene monomer and 1.264 parts by weight of perfluorinated monomer. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

Comparative Example 1

Polymerization was obtained in the same manner as in Example 1 except that the monomer mixture composition was changed to 100 parts by weight of methyl methacrylate. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

Comparative Example 2

The polymerization product was obtained in the same manner as in Example 1 except that the monomer mixture composition was changed to 50 parts by weight of methyl methacrylate, 28.93 parts by weight of styrene monomer, and 21.07 parts by weight of perfluorinated monomer. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

Comparative Example 3

Polymerization was obtained in the same manner as in Example 1 except that the monomer mixture composition was changed to 70 parts by weight of methyl methacrylate and 30 parts by weight of styrene monomer. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

Comparative Example 4

Polymerization was obtained in the same manner as in Example 1 except that the monomer mixture composition was changed to 70 parts by weight of methyl methacrylate and 30 parts by weight of perfluoromonomer. The prepared polymer was evaluated for physicochemical properties through a conventional extrusion process.

After confirming that the prepared polymers of Examples and Comparative Examples of the water content is 0.5% or less, a physical specimen was prepared using an extrusion and injection machine at 230 ° C. extrusion temperature.

The physical properties of the prepared specimens are shown in Table 1 by the following evaluation method.

(1) Molecular weight: Measured using GPC (Gel Permeation Chromatography).

(2) Transparency: Measured by a color computer measuring instrument manufactured by SUGAINSTRUMENT, Japan, and the results are expressed as total light transmittance and HAZE.

Total light transmittance (%) = (sample transmitted light) / (sample irradiation light) × 100

HAZE (%) = (dispersed transmitted light) / (total light transmittance) x 100

(3) YI (Yellow Index): Measured by a spectrophotometer in accordance with the standard of ASTM D-1925.

(4) Surface energy: The contact angles of water and hexadecane were measured by a Phoenix 300 instrument from SEO of Korea.

(5) Appearance of resin surface: According to visual observation, transparency, pinhole, pearl, and flow mark degree were designated as ◎ excellent ＞ ○ good ＞ △ deteriorated ＞ ▲ bad.

As shown in Table 1, Examples 1 to 5 have the same or similar level of transparency as that of the polymethyl methacrylate resin of Comparative Example 1, and observed that the contact angle between water and oil (hexadecane) is high.

As in Comparative Example 4, in the case of the perfluorinated monomer and the methacrylate binary copolymer, contact angles with water and oil may be high, but a decrease in transparency may occur, and Comparative Example 3 with no perfluorinated monomer may be used. When the contact angle with respect to oil is not improved and the methyl methacrylate content is as low as 50 parts by weight as in Comparative Example 2, the perfluoromonomer was not uniform in the monomer mixture composition, so that the transparency and the surface appearance were also decreased.

The present invention improves the surface contamination property while maintaining the refractive index of the methacryl resin, that is, transparency, and various problems due to the decrease in transparency due to the use of an antistatic agent and the surface coating, that is, poor coating, low recyclability, and problems with the coating organic agent. It has the effect of the invention which provides the backless methacrylate-styrene type compound-perfluoro acrylate terpolymer, and its manufacturing method.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (12)

60 to 97 weight percent of methacrylate component; And 3 to 40% by weight of a styrene-based compound component and a perfluorinated acrylate component, wherein the styrene-based compound component and a perfluoro acrylate component are in a weight ratio of 55/45 to 60/40. Styrene-based compound-perfluorine acrylate terpolymer. The methacrylate-styrene compound-perfluoro acrylate terpolymer according to claim 1, wherein the styrene-based compound component and the perfluorine acrylate component are in a weight ratio of 57/43 to 58/42. The methacrylate-styrene compound-perfluoro acrylate terpolymer according to claim 1, wherein the perfluorinated acrylate has a CF chain length of 4 or more and 8 or less. The method of claim 1, wherein the methacrylate is selected from the group consisting of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and mixtures thereof; The styrene-based compound is a methacrylate-styrene-based perfluoro acrylate terpolymer, characterized in that selected from the group consisting of styrene, α-methyl styrene, α-ethyl styrene, ot-butyl styrene and mixtures thereof . An initiator and a molecular weight regulator are added to the monomer mixture which mixed the methacrylate monomer, the styrene-type monomer, and the perfluoro acrylate monomer, and the monomer mixture liquid was prepared; And Dispersing and polymerizing the monomer mixture into an aqueous dispersion for 2 to 8 hours at 70 to 120 ° C; Method for producing a methacrylate-styrene-based compound-perfluoro acrylate terpolymer, characterized in that consisting of a step. According to claim 5, wherein the content of the methacrylate monomer is 60 to 97 parts by weight based on 100 parts by weight of the monomer mixture, the weight ratio of the styrene monomer and the perfluorinated acrylate monomer is 55 / 45-60 / 40 A method for producing a methacrylate-styrene compound-perfluorine acrylate terpolymer. The method for producing a methacrylate-styrene compound-perfluoro acrylate terpolymer according to claim 6, wherein the weight ratio of the styrene monomer and the perfluorinated acrylate monomer is 57 / 43-58 / 42. The method of claim 5, wherein the initiator is a peroxide-based oil-soluble initiator, and 0.3 to 1 part by weight based on 100 parts by weight of the monomer mixture. . The method of claim 8, wherein the peroxide-based fat-soluble initiator is octanoyl peroxide, decanyl peroxide, lauroyl peroxide, benzoyl peroxide, monochlorobenzoyl peroxide, dichlorobenzoyl peroxide, paramethylbenzoyl peroxide, Methacrylate-styrene-based compounds selected from the group consisting of tertiarybutyl perbenzoate, azobisisobutyronitrile, azobis (2,4-dimethyl) -valeronitrile and mixtures thereof Method for preparing bovine acrylate terpolymer. The method of claim 5, wherein the molecular weight regulator is 0.02 to 10 parts by weight based on 100 parts by weight of the monomer mixture, n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tertiary dodecyl mercaptan, isopropyl Methacrylate-styrene-based perfluoro acrylate terpolymers selected from the group consisting of mercaptans, n-amyl mercaptans, carbon tetrachloride, alpha methylstyrene dimers, alpha ethylstyrene dimers and mixtures thereof Process for the preparation of coalescing. The method of claim 5, wherein the dispersing agent is an acrylic acid acrylate copolymer, the methacrylate-styrene compound-perfluoro acrylate terpolymers, characterized in that 0.002 to 0.2 parts by weight based on 100 parts by weight of the monomer mixture. Way. The methacryl resin manufactured by extrusion-molding the copolymer of any one of Claims 1-4.