KR20100133681A - Cardanol derivatives, preparation method thereof and cardanol polymer prepared therefrom - Google Patents

Abstract

PURPOSE: An acrylic derivative of cardanol is provided to ensure excellent stability compared with conventional cardanol or derivatives thereof, and excellent polymer reactivity and polymerization. CONSTITUTION: A cardanol derivative is represented by chemical formula 2. In chemical formula 2, A is hydrogen or methyl, and R is represented by chemical formula 2-a. The cardanol is obtained from cashew nut shell liquid. A method for preparing the cardanol derivative comprises a step for reacting cardanol with glycidyl (meth)acrylate in the presence of a base catalyst and then purifying the resultant.

Description

Cardanol derivatives, preparation methods thereof and cardanol polymers prepared therefrom {CARDANOL DERIVATIVES, PREPARATION METHOD THEREOF AND CARDANOL POLYMER PREPARED THEREFROM}

 The present invention relates to an acrylic derivative obtained from cardanol, a preparation method thereof and a cardanol polymer polymerized therefrom.

Derivatives derived from cashew nutshell liquid (CNSL), a natural vegetable oil extracted from the cashews of cashews in the rainforest family, are frequently found in epoxy curing agents, phenolic resins, surfactants and emulsion breakers. Has been used. Among these, cardanol extracted from the cashew nut shell liquid is represented by the following Chemical Formula 1:

 As can be seen from the above formula, cardanol is a mixture of phenol derivatives having four kinds of alkyl groups in the meta position, and the compounds having each alkyl group are 3%, 34%, 22% and 41%, respectively, as described above. It is mixed at the ratio of.

However, cardanol itself has a problem that the stability is not great. In addition, phenolic groups present in cardanol are known to corrode skin mucosa, denature proteins and cell prototypes, damage cell membranes of erythrocytes and interfere with the transfer of oxygen to cause cancer. In addition, since the polymerization reactivity is very low, only a polymer having a number average molecular weight of several thousand or less can be obtained even if polymerization and curing are caused by oxidation by maintaining an appropriate temperature and humidity.

Various cardanol derivatives have been studied to solve this problem, and as a result, derivatives capable of forming a coating film having excellent physical properties by adding a curing agent or heating and forming a molding foam having excellent physical properties have been developed.

For example, GB 2,262,525 discloses cardanol ethoxylation with ethylene oxide to form a surface activity that is balanced between the hydrophilic and lipophilic ends of the molecule. In addition, Korean Patent Publication No. 2001-0093814 discloses a method for hydroxyalkylation of cardanol by reacting with a cyclic organic carbonate in the presence of an organic or inorganic catalyst, and Korean Patent Registration No. 10-0829071 discloses a cashew nut extract Discloses a method for preparing an epoxy resin by reacting with a haloalkylene oxide, and Korean Patent Registration No. 10-0775786 discloses that cardanol is alkylated and acylated with dimethyl sulfate or X-Cl to be non-toxic and volatile. A method for producing a solvent free is disclosed.

In recent years, a method for synthesizing cardanyl acrylate by reacting cardanol with acryloyl chloride has been studied by several research groups.

However, these existing cardanol derivatives still need to be improved in terms of thermal stability, polymerization reactivity, workability in forming a film, and toxicity to human skin. In addition, the raw cardanol genie has a disadvantage of darkening due to its unique dark brown color, which does not make the color of the material unique when forming a coating film. In addition, the cardanol polymer polymerized therefrom does not have excellent properties such as mechanical properties and weather resistance.

Accordingly, there is a need for the preparation of new cardanol derivatives and cardanol-based polymers having improved effects.

Accordingly, it is an object of the present invention to provide a novel cardanol derivative, a preparation method thereof, and a cardanol-based polymer that can solve the problems of the conventional cardanol derivatives as described above.

In accordance with the above object, the present invention provides a cardanol derivative represented by the following formula (2):

Wherein A is hydrogen or methyl and R is as follows:

According to another object of the present invention, the present invention provides a method for preparing the cardanol derivative comprising the step of purifying the cardanol and glycidyl (meth) acrylate under a base catalyst.

According to another object, the present invention provides a cardanol-based polymer, the main chain consisting of a repeating unit of the formula (3):

Wherein A is hydrogen or methyl and R is as follows:

Acrylic derivatives of cardanol according to the present invention have excellent stability, excellent polymer reactivity and polymerizability, and bright colors compared to conventional cardanol or derivatives thereof. In addition, the cardanol-based polymer of the present invention is excellent in mechanical properties, weather resistance, antimicrobial properties, etc., can be usefully used in industrial fields such as coatings, adhesives, plastics, rubber, composites, nanomaterials.

Hereinafter, the present invention will be described in detail.

As a 1st subject of this invention, the acryl-type derivative obtained from cardanol is provided.

The cardanol derivative of the present invention uses, as a raw material, the cardanol of the formula (1) extracted from the cashew nut shell liquid, which is a natural vegetable oil extracted from the fruit skin of Kash belonging to the lacquer family inhabiting the rainforest.

The cardanol derivative of the present invention has the structure of Formula 2, and has the name 2-hydroxy-3-cardanylpropyl (meth) acrylate. The cardanol derivative of the present invention is a mixed composition of compounds having four different R groups, similar to the raw cardanol, and the ratio for each R group is the same as the raw cardanol.

Conventional cardanol derivatives have a dark brown color that is unique to raw material cardanol, and thus have a disadvantage of darkening due to the inability to use the material's unique color when forming a coating film, whereas the cardanol derivative of the present invention has a bright color, It can be usefully used in coatings, adhesives, plastics, rubber, composites, nanomaterials, and the like.

In addition, the cardanol derivative of the present invention significantly increased the stability compared to the conventional cardanol or derivatives thereof, and specific comparative data thereof is shown in the following test examples and FIG. 7. In addition, since the toxic phenol group of the conventional cardanol is substituted with another functional group, skin contact salt can be reduced. In addition, since the cardanol derivative of the present invention is excellent in reactivity and photoinitiation, free radical polymerization is possible by an initiator such as azobisisobutyronitrile (AIBN), and a polymer having a number average molecular weight of tens of thousands or more can be obtained.

As a second object of the present invention, there is provided a method for producing the cardanol derivative of the present invention.

The cardanol derivative of the present invention is prepared by reacting a hydroxy functional group of cardanol with glycidyl (meth) acrylate under a base catalyst, followed by purification.

In the reaction step, the base catalyst is potassium hydroxide (KOH), barium hydroxide (Ba (OH) ₂ ), cesium hydroxide (CsOH), sodium hydroxide (NaOH), strontium hydroxide (Sr (OH) ₂ ), calcium hydroxide (Ca ( OH) ₂ ), lithium hydroxide (LiOH) and rubidium hydroxide (RbOH) can be used at least one selected from the group consisting of.

As the molar ratio of the reactants, the glycidyl (meth) acrylate is preferably reacted at a ratio of 0.5 to 4 mol per mol of the raw cardanol, and more preferably 1 to 2 mol. In addition, the base catalyst is preferably added at a rate of 0.5 to 3 mol per mol of cardanol, and more preferably 0.9 to 2 mol.

As reaction conditions, it is preferable that reaction temperature is 0-50 degreeC, and it is more preferable that it is 15-35 degreeC. The reaction time is preferably 10 to 48 hours, more preferably 10 to 24 hours.

In addition, the purification step may be carried out by extraction, distillation under reduced pressure, column chromatography, and the like, most preferably by extraction.

As a third subject of the present invention, a cardanol polymer is provided.

The cardanol polymer of the present invention has a structure in which the main chain consists of repeating units represented by Formula 3, and has a name of poly (2-hydroxy-3-cardanylpropyl (meth) acrylate).

The cardanol polymer of the present invention has a high molecular weight, for example, the number average molecular weight may be 5,000 to 50,000, the weight average molecular weight may be 10,000 to 200,000.

Such a cardanol-based polymer of the present invention may be prepared by polymerizing the cardanol derivative of Formula 2 as a monomer. Specifically, the cardanol derivative of Chemical Formula 2 may be dissolved in a solvent together with a reaction initiator, polymerized at 50 to 150 ° C. for 1 to 3 hours, and then purified. The polymer thus obtained may be formed into a coating film on any substrate by curing at room temperature or by curing with UV.

The cardanol polymer of the present invention has many advantages such as high surface hardness, high thermal stability, and antimicrobial properties, compared to the prior art, and thus is useful in industrial fields such as coatings, adhesives, plastics, rubbers, composites, nanomaterials, and the like. Can be used.

Hereinafter, the present invention will be described in more detail with reference to preferred examples. The following examples are merely to illustrate, but not to limit the invention.

Examples 1 and 2 below describe examples of preparing the cardanol derivatives of the present invention.

The starting materials and respective reagents used in the examples below can be purchased as follows:

Cardanol- Mercury, India (NMR and IR spectra of cardanol are attached to FIGS. 1 and 2);

N, N- dimethylsulfoxide (DMSO)-Junsei, Japan; And

Glycidyl Methacrylate-TCI, Japan.

Example 1 Preparation of Cardanol Derivatives of the Invention (Using KOH Catalysts)

Cardanol (0.02 mol, 6 g) was dissolved in N, N- dimethylsulfoxide (DMSO) and then KOH (0.02 mol, 1.16 g) was added. Glycidyl methacrylate (0.04 mol, 5.7 g) was added thereto and reacted at room temperature and atmospheric pressure for 10 hours.

Then, a few drops of dilute hydrochloric acid was added to terminate the reaction, and DMSO was removed using a vacuum distillation unit. Methylene chloride (MC) and distilled water were added thereto to extract the product, and then the MC layer in which the product was dissolved was separated and a small amount of water remaining in the MC layer was completely removed using MgSO ₄ . The MC was then removed using a vacuum distillation unit to obtain the desired 2-hydroxy-3-cardanylpropyl methacrylate (hereinafter referred to as "HCPM") in a light yellow viscous liquid state (yield: 46%). The NMR and IR measurements of the product were as follows and are shown in FIGS. 3 and 4, respectively:

¹ H NMR (CDCl ₃ , TMS): δ = 0.88 (t, J = 6.78 Hz, 3H, -C H ₃ ), 1.20-1.40 (m, CH ₃ (C H ₂ ) ₁₂ CH _2- ), 1.60 ( m, 2H, CH ₃ (CH ₂ ) ₁₂ C H ₂ CH _2- ), 1.97 (s, 3H, -OC (O) C (C H ₃ ) = CH ₂ ), 2.02 (m, 2H, -CH ₂ CH ₂ C H ₂ CH = CHCH _2- ), 2.57 (t, J = 8.04 Hz, 2H, -OC ₆ H ₄ C H _2- ), 2.75-2.90 (m, -CH ₂ CH = CHC H ₂ CH = CH-), 3.94-4.40 (m, 5H, -OC H ₂ C H (OH) C H ₂ OC (O)-), 5.20-5.50 (m, -CH ₂ C H = C H CH _2- ), 5.62 and 6.26 (s, 2H, -OC (O) C (CH ₃ ) = C H ₂ ), 6.67-6.83 (m, 3H, aromatic), 7.19 (t, J = 7.5 Hz, 1H, aromatic);

^{IR: 1155 cm -1 (C (} Ar) -O stretching vibration (m- alkyl ^{phenol)), 1720 cm -1 (C} = O stretching vibration), 3010 cm ^-1 (CH vibrations of the unsaturated hydrocarbon), 3471 cm ^{- 1} (OH telescopic vibration).

Cardanol is a mixture of compounds having a plurality of double bonds. In Example 1, cardanol is substituted with a phenol group as a starting material. In this case, since the double bond is less reactive than the phenol group, the double bond remains unreacted, which can be confirmed by changing the NMR peak before and after the reaction. That is, as can be seen in Figures 1 and 3, the integral ratio of the hydrogen peak of the vinyl group at 5.20-5.50 ppm is almost the same before and after the reaction. (Cardanol-3.07, HCPM-3.01) That is, it can be seen that the composition ratio before and after the reaction did not change, and as a result, it was found that the product obtained in Example 1 was 2-hydroxy-3-cardanylpropyl methacrylate having the following composition. Can:

Example 2 Preparation of Cardanol Derivatives of the Invention (With NaOH Catalyst)

Cardanol (0.033 mol, 10 g) was dissolved in N, N- dimethylsulfoxide (DMSO) and then NaOH (0.033 mol, 1.32 g) was added. Glycidyl methacrylate (0.066 mol, 9.4 g) was added thereto and reacted at room temperature and atmospheric pressure for 10 hours.

Thereafter, a few drops of diluted hydrochloric acid was added to terminate the reaction, and then DMSO was removed using a vacuum distillation unit. Methylene chloride (MC) and distilled water were added thereto to extract the product, and then the MC layer in which the product was dissolved was separated and a small amount of water remaining in the MC layer was completely removed using MgSO ₄ . Thereafter, MC was removed using a reduced pressure distillation unit to obtain the desired 2-hydroxy-3-cardanylpropyl methacrylate as a light yellow viscous liquid (yield: 50%). NMR and IR analysis of the product were the same as in Example 1.

Example 3 Synthesis of Cardanol-Based Polymer of the Present Invention

The cardanol derivative (HCPM, 5 mmol, 2.22 g) and AIBN (0.22 g) obtained in Example 1 were dissolved in 20 mL of THF. After the condenser was installed, the mixture was reacted at reflux at 100 ° C. for 2 hours. After the reaction, the precipitate was precipitated in a mixed solution of methanol and distilled water. The precipitate was re-dissolved in THF and reprecipitated in methanol or distilled water. As a result, poly (2-hydroxy-3-cardanylpropyl methacrylate) (hereinafter referred to as "P-HCPM") was synthesized, and the number average molecular weight and the weight average molecular weight were 14,000 g / mol, respectively, as a result of GPC measurement. And 82,000 g / mol. NMR and IR spectral results of polymerized P-HCPM are attached to FIGS. 5 and 6.

¹ H NMR (CDCl ₃ , TMS): δ = 0.87 (t, J = 6.96 Hz, 3H, -C H ₃ ), 1.20-1.40 (m, CH ₃ (C H ₂ ) ₁₂ CH _2- ), 1.55 ( m, 2H, CH ₃ (CH ₂ ) ₁₂ C H ₂ CH _2- ), 1.97 (s, 3H, -CH ₂ -C (C H ₃ ) (C = O)-), 2.01 (m, 2H,- CH ₂ CH ₂ C H ₂ CH = CHCH _2- ), 2.52 (t, 2H, -OC ₆ H ₄ C H _2- ), 2.75-2.90 (m, -CH ₂ CH = CHC H ₂ CH = CH-) , 3.94-4.40 (m, 5H, -OC H ₂ C H (OH) C H ₂ OC (O)-), 5.20-5.50 (m, -CH ₂ C H = C H CH _2- ), 6.67-6.83 (m, 3H, aromatic), 7. 13 (t, 1H, aromatic);

^{IR: 1155 cm -1 (C (} Ar) -O stretching vibration (m- alkyl ^{phenol)), 1728 cm -1 (C} = O stretching vibration), 3010 cm ^-1 (CH vibrations of the unsaturated hydrocarbon), 3460 cm ^{- 1} (OH telescopic vibration)

Example 4 Coating Film Formation Using Cardanol-Based Polymer of the Present Invention

The cardanol-based polymer (P-HCPM) synthesized in Example 3 was dissolved in THF to prepare a 1 wt% solution. 2 mL of this solution was dropped on an iron plate (3 cm x 3 cm) and dried for about 30 minutes. The formed coating film was cured at room temperature (curing at room temperature) or cured (UV curing) with UV exposure to form a coating film. The thickness of the formed coating film was 20-25 micrometers.

Test Example

Test Example 1 Measurement of Thermal Stability

The thermal stability of the cardanol derivative (HCPM) of the present invention obtained in Example 1 was evaluated by comparison with raw material cardanol through TGA analysis. A comparative analysis result graph is attached to FIG. 7.

As can be seen in Figure 7, the cardanol derivative of the present invention was measured at 432 ℃ compared to the temperature at which the mass of the original 50% is 288 ℃ in the case of the raw material cardanol. In this way, since it rose by more than 140 ℃ compared to the raw material cardanol, it can be seen that the thermal stability is greatly improved.

Test Example 2 Measurement of Mechanical Properties

Mechanical properties of the coating film obtained in Example 4 were measured by using an ultra-fine hardness meter. At this time, the load (load) was set to 300 mN and measured by applying a force for 20 seconds, the results are shown in Table 1 below.

As shown in Table 1, the coating film prepared by curing the cardanol-based polymer of the present invention at room temperature or UV curing showed high surface strength. This is a coating film (100 N / mm2) that has been cured for 7 days using a cobalt catalyst (100 N / mm2) by Kobayashi Group of Kyoto University, Japan, or a coating film that has been cured for 21 days by applying heat (80 N / mm2). It is much better than the surface strength value. (R. Ikeda, H. Tanaka, H. Uyama, S. Kobayashi, Macromol.Rapid Commun. 2000 , 21 , 496-499; R. Ikeda, H. Tanaka, H. Uyama, S. Kobayashi, Polymer 2002 , 43 , 3475-3481)

In particular, the UV cured coatings showed very high surface strength and the pressed depth was also very thin. That is, the cardanol-based polymer (P-HCPM) of the present invention can be seen that the hardness is improved through UV without toxic organic curing agents or inorganic curing agents such as cobalt naphtanate.

Test Example 3 Measurement of Weatherability

In order to measure the change in gloss in weather resistance, the coating film obtained in Example 4 was subjected to a long time (120 hours) exposure test to UV, and then the change in gloss was measured three times. Gloss was measured with a gloss meter and calculated by measuring light reflected at a 45 degree angle by irradiating the sample with light at a 45 degree angle. The results are summarized briefly in Table 2 below.

As shown in Table 2, the gloss decreases slightly after exposure to UV, but both room temperature curing and UV curing maintain gloss above 80 degrees, and especially UV curing exhibits a gloss near 90 degrees. . Therefore, it can be seen that the cardanol polymer of the present invention has sufficient gloss that can be used commercially.

Test Example 4 Measurement of Antimicrobial Activity

The antimicrobial activity against Pseudomonas aeruginosa of the coating film obtained in Example 4 was measured. First, a certain amount of Pseudomonas aeruginosa was inoculated onto the test piece, the coating film obtained in Example 4 was covered, and then incubated in a 37 ° C. incubator for 24 hours. After incubation, the bacteria remaining on the film and the test piece were washed with a buffer solution, and then inoculated with the solution in agar medium (nutrient agar, NA) and plated. The colonies were counted after 24 hours incubation in a 37 ° C. incubator. In addition, as a control, the number of colonies obtained after culturing in the same manner as above but without covering the coating film was counted. Using these measured values, the bacterial reduction rate was calculated according to the following equation.

The bacterial reduction rate of the room temperature curing and UV curing material of P-HCPM measured by the above method is shown in Table 3 below.

As can be seen in Table 3, the cardanol-based polymer (P-HCPM) of the present invention showed a high antimicrobial activity of 99.9% in both the room temperature curing film and the UV curing coating film.

The embodiments thus far are merely illustrative for the purpose of illustrating the invention, and various modifications and equivalent other embodiments which can be made by those skilled in the art within the scope of the appended claims are as follows. Understand that it can be done.

1 is a ¹ H-NMR spectrum of a raw cardanol.

2 is an IR spectrum of the raw cardanol.

3 is a ¹ H-NMR spectrum of a cardanol derivative synthesized in Example 1. FIG.

4 is an IR spectrum of a cardanol derivative synthesized in Example 1. FIG.

5 is a ¹ H-NMR spectrum of a cardanol polymer polymerized in Example 4. FIG.

FIG. 6 is an IR spectrum of a cardanol polymer polymerized in Example 4. FIG.

7 is a graph comparing the TGA measurement results of the cardanol derivative (HCPM) synthesized in Example 1 with the raw cardanol.

Claims (12)

Cardanol derivatives represented by the following formula (2): [Formula 2]

Wherein A is hydrogen or methyl and R is as follows:

The method of claim 1, Cardanol derivative, characterized in that the cardanol is obtained from cashew nut shell liquid (CNSL). A method for preparing a cardanol derivative according to claim 1 comprising the step of purifying cardanol and glycidyl (meth) acrylate under a base catalyst. The method of claim 3, The base catalyst is potassium hydroxide (KOH), barium hydroxide (Ba (OH) ₂ ), cesium hydroxide (CsOH), sodium hydroxide (NaOH), strontium hydroxide (Sr (OH) ₂ ), calcium hydroxide (Ca (OH) ₂ ) And at least one selected from the group consisting of lithium hydroxide (LiOH) and rubidium hydroxide (RbOH). The method of claim 3, The reaction is carried out at a ratio of 0.5 to 4 mol of the cardanol per mol of the glycidyl (meth) acrylate. The method of claim 3, Wherein said base catalyst is added at a rate of 0.5 to 3 moles per mole of said cardanol. The method of claim 3, The reaction is characterized in that for 10 to 48 hours at a reaction temperature of 0 to 50 ℃. The method of claim 3, Said purifying step is carried out by extraction. Cardanol-based polymer, the main chain is composed of a repeating unit of formula (3)

Wherein A is hydrogen or methyl and R is as follows:

10. The method of claim 9, The polymer is a cardanol-based polymer, characterized in that the number average molecular weight is 5,000 to 50,000. 10. The method of claim 9, The polymer is a cardanol-based polymer, characterized in that prepared by polymerizing a cardanol derivative of the formula (2): [Formula 2]

Wherein A is hydrogen or methyl and R is as follows:

10. The method of claim 9, The polymer is cardanol-based polymer, characterized in that used in the industrial field of coatings, adhesives, plastics, rubber, composites or nanomaterials.

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