KR20000047288A - Production process of core shell rubber modified phenol hardening agent with high molecular weight - Google Patents

Abstract

The present invention relates to a method for producing a high molecular weight coarse rubber-modified phenol curing agent, and more particularly, low molecular weight coasel by dispersing and reacting a corel rubber resin with a low molecular weight epoxy compound obtained by reacting a polyhydric phenol with epichlorohydrin. A rubber-modified epoxy resin is prepared, and the low-molecular-weight coasel rubber-modified epoxy resin is reacted with an excess of polyhydric alcohol, and then it has excellent impact resistance even at low temperatures that can be prepared by adding an accelerator. The present invention relates to a method for preparing a high molecular weight coasel rubber-modified phenolic hardener that can be easily produced without undergoing a complicated process of extracting a.

Description

Method for producing high molecular weight coasel rubber-modified phenol hardener.

The present invention relates to a method for producing a high molecular weight coarse rubber-modified phenol curing agent, and more particularly, low molecular weight coasel by dispersing and reacting a corel rubber resin with a low molecular weight epoxy compound obtained by reacting a polyhydric phenol with epichlorohydrin. A rubber-modified epoxy resin is prepared, and the low-molecular-weight coasel rubber-modified epoxy resin is reacted with an excess of polyhydric alcohol, and then it has excellent impact resistance even at low temperatures that can be prepared by adding an accelerator. The present invention relates to a method for preparing a high molecular weight coasel rubber-modified phenolic hardener that can be easily produced without undergoing a complicated process of extracting a.

In the case of the bisphenol-A terminal phenol curing agent, which is a conventional curing agent used as a composition of epoxy powder coating, there is a disadvantage in that impact resistance during thickening or rapid curing is lowered.

In the conventional method for preparing a phenol curing agent, an excess of divalent phenol is reacted with a linear epoxy resin having an equivalent weight of 170 to 210 to prepare a resin having an equivalent weight of terminal hydroxyl group of 200 to 1,000, and then to adjust the curability of the resin. The method of melt-blending the imidazole compound selectively [US Pat. No. 4,767,832] and the polyfunctional epoxy resin were added and reacted by diluting the imidazole compound having a secondary amino group in a solvent at room temperature, and then adding the polyfunctional phenol to the solution. There is a method (US Pat. No. 5,077,355) for preparing a curing agent by adding the solvent and recovering the solvent under reduced pressure.

In the case of the curing agent prepared by the above method, when applied as a thick film type powder coating (for example, a medium anticorrosive powder) or a fast curing type powder coating, there is a problem of a change in the time-dependent change in impact resistance of the coating film or a curing reaction occurs while the paint is stored. .

Accordingly, in the present invention, in order to solve the problems of the prior art, the core cell rubber resin is dispersed and reacted with a low molecular weight epoxy compound obtained by reacting a polyhydric phenol and epichlorohydrin, and an addition reaction is performed using the polyhydric phenol compound in excess. By selectively mixing the accelerator for controlling the reaction rate, the impact resistance is excellent, there is no change in physical properties during storage, and the high molecular weight core cell rubber modification can be easily produced without the complicated process of extracting water or solvent. It aims at manufacturing the phenol hardening agent.

The present invention in the preparation of high molecular weight corel rubber modified phenol hardener,

Preparing a low molecular weight corel rubber-modified epoxy resin by dispersing the corel rubber resin in a mixture of a low molecular weight epoxy compound or a low molecular weight epoxy compound, a noblock epoxy resin and an aliphatic epoxy resin;

After the polyhydric phenol is reacted in excess with the low molecular weight corel rubber-modified epoxy resin, an accelerator is added.

The present invention will be described in detail based on the manufacturing method as follows.

First, a low molecular weight core cell rubber-modified epoxy resin is prepared by dispersing a corel rubber resin into a mixture of a low molecular weight epoxy compound or a low molecular weight epoxy compound, a noblock epoxy resin and an aliphatic epoxy resin.

In the present invention, a bisphenol A type or bisphenol F type epoxy resin can be used as the low molecular weight epoxy compound. In the present invention, a bisphenol A type epoxy resin having a molecular weight of 300 to 2,000 and an epoxy equivalent weight (EEW) of 170 to 300 is used. Preferably, commercially available bisphenol-type epoxy resins used in the present invention include R-8815, R-8816, R-8827, R-8828, R-8829 (KCC), and the like.

As the noblock epoxy resin of the present invention, cresol noblock epoxy resin or phenol noblock epoxy resin having an average number of functional groups of 3 to 7 and an epoxy equivalent of 170 to 300 may be used, and examples of commercially available noblock epoxy resins used in the present invention may be used. There are N-8460, N-8470 (KCC Co., Ltd.), DEN-431, DEN-438, DEN-439, DEN-485 (Dow Resin).

Examples of the aliphatic epoxy resins include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether and triglycidyl tris (2-hydroxyethyl) having an epoxy equivalent of 120 to 400. Isocyanate, glycerol polyglycidyl ether, trimethylolpropanepolyglycidyl ether, neopentylglycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol edicidyl ether, ethylene, polyethylene Those selected from glycol diglycidyl ether, propylene, polypropylene glycol diglycidyl ether and derivatives thereof can be used. Examples of commercially available aliphatic epoxy resins used in the present invention include EX-611, 612, 512, 521, 411, 421, 301, 313, 314, 321, 211, 212, 252, 821, 830, 831, 841, 920 And 921 (Nagase Chemical).

As a starting material of the present invention, it is preferable to use a low molecular weight polyepoxide compound alone or to mix 20% by weight or less of a noblock epoxy resin and an aliphatic epoxy resin. There is a problem that the impact resistance is lowered in the physical properties of the final resin. In the present invention, the dispersion reaction is carried out for 2 to 4 hours at a temperature of 50 ~ 150 ℃, if the reaction temperature and the reaction time is out of the above range is not dispersed properly in the final resin product particles remain in the resin product It is not desirable because of problems.

As the coacell rubber used in the present invention, it is preferable to use a coarse particle having an average diameter of 300 to 20,000 mm 3, and in the present invention, the coacel particles have a graft rubber particle structure and have an average of coasel particles. It is more preferable to use the thing of 900-2000 mm in diameter. The core has elastic properties similar to rubber and is made of conjugated diene rubber, acrylic rubber, silicone rubber or copolymers thereof. In addition, some of the constituents of the cell are non-polar components in which particles in the epoxy resin are grafted to the core, and some are composed of polar components capable of reacting with epoxy groups or phenol groups. The average molecular weight of the cell used in the present invention is generally 10,000 to 250,000, and is composed of a polymer that can be melted well in an epoxy resin, and the main constituents are ethylene unsaturated compounds such as styrene, acrylate, methacrylate, and acryl. Vinyl monomers such as ronitrile, acrylic acid, methacrylic acid, hydroxypropyl acrylate, hydroxyethyl acrylate, glycidyl acrylate and glycidyl methacrylate. In particular, a cell polymer having a reactive group is very easy to disperse with an epoxy resin, and in the present invention, styrene / acrylonitrile / glycidyl methacrylate, styrene / acrylonitrile / acrylic acid, ethyl acrylate / meta Cell polymers such as crylic acid, styrene / methyl methacrylate / methacrylic acid, styrene / methyl methacrylate / glycidyl methacrylate, styrene / acrylonitrile / methyl methacrylate and glycidyl methacrylate Can be used.

Examples of commercially available core cells used in the present invention include polybutyl acrylate core / polymethyl methacrylate cells such as KM-334 and KM-355P (Rom & Has Co., Ltd.), EXL type of Curreha Co., Ltd. MBS (styrene butadiene methyl methacrylate) core cell such as C-type product, and silicone acrylic core cell include S-type product of Misubishi Rayon Co., Ltd., EXL-8866 and EXL-2611 having carboxy polar group And acrylic acryl cores such as EXL-2314 (Cureha Co., Ltd.) having a glycidyl group.

In addition, in the present invention, a core cell having a functional group or a core cell having a structure that can be completely dispersed in a low molecular weight epoxy resin was selected. In this case, when the thickness of the cell is too thick, the core cell is incompletely dispersed and the impact resistance is made. There is a risk of deterioration of the properties, and if the cell is too thin, the core becomes relatively thick, causing a problem that the structure of the core cell is destroyed during dispersion.

In the present invention, the content of the corel is used in an amount of 10 to 70 parts by weight based on 100 parts by weight of the low molecular weight epoxy compound. If the content of the corel is less than 10 parts by weight, the improvement of impact resistance is insignificant and there is no meaning of denaturation. If the content exceeds 70 parts by weight, the content of corel is too high compared to the low molecular weight resin, there is a problem that can not be dispersed. The epoxy equivalent of the low molecular weight corel rubber modified epoxy resin obtained as a result of the said dispersion reaction is 150-450 g / eq.

In this manner, a low molecular weight corel rubber-modified epoxy resin is prepared, and the low molecular weight corel rubber-modified epoxy resin is reacted with an excess amount of polyhydric phenol in an excess amount, and then a promoter is added to the high molecular weight corel rubber. A modified phenol hardener is prepared.

In this case, the low molecular weight corel rubber-modified epoxy resin, noblock epoxy resin and aliphatic epoxy resin are as described above.

The polyhydric phenol used in the present invention has properties suitable for use in powder coating by increasing the molecular weight by addition reaction with a low molecular weight epoxy resin, and in the present invention, 2,2-bis (P-hydride) as the polyhydric phenol compound. Hydroxyphenyl) propane, (2,4-dihydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, 2,2-bis (3-isopropyl-4-hydroxyphenyl) propane, 2,2- Bis (2-isopropyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) ethane, 1,3-bis (3-methyl-4-hydroxyphenyl) propane, bis (4 -Hydroxy-2,6-dimethyl-3-methoxy) phenyl, 2,2-bis (4-hydroxyphenyl) propane, 4,4-dihydroxyphenyl, bis (4-hydroxy-3-chloro Naphthyl) ether, bis (4-hydroxy-3-bromophenyl) ether, 1,1-bis (4-hydroxyphenol) -2-phenylethane and 2,4-bis (P-hydroxyphenyl) 4-methylphene and the like can be used, and in the present invention, 2,2-bis (P-hydroxyphenol) Preference is given to using propane, (2,4-dihydroxyphenol) methane. The polyhydric phenol is preferably used in a molar ratio of 1.0 to 4.0 with respect to a low molecular weight corel rubber-modified epoxy resin. If the content is less than 1.0 molar ratio, the polyhydric phenol becomes a low molecular phenol curing agent, resulting in poor storage properties or too low a curing rate. Fast change is affected over time, and exceeds 4.0 molar ratio, there is a problem that the molecular weight is too high or the hydroxyl equivalent is too high, the reactivity is lowered.

The promoter used in the present invention is a raw material used to control the reaction rate of the powder coating, and in the present invention, imidazoles, phosphines, tertiary amines, quaternary ammonium salts and quaternary phosphonium salts may be used as the promoters. In the present invention, it is preferable that the accelerator is contained in an amount of 1 to 15% by weight in the total phenolic curing agent composition. If the content is less than 1% by weight, the curing property is adversely affected and the content is more than 15% by weight. There is a problem in that the appearance of the coating film drops because the curing speed is too fast.

The reaction is preferably carried out at a temperature of 150 ~ 200 ℃, if the reaction temperature exceeds 200 ℃ there is a problem that the catalytic activity falls at a high temperature, the reaction rate is slow at a temperature below 150 ℃ to remain unreacted material Due to this there is a problem that the physical properties of the final polymer phenol hardener product is lowered. The epoxy equivalent of the polymeric coasel rubber modified phenol hardener obtained as a result of the said reaction is 200-1,000 g / eq, and a softening point is 70-140 degreeC.

As described above, in the present invention, the low molecular weight epoxy resin and the core cell are completely dispersed, and thus, a high molecular weight cored rubber-modified phenol curing agent having excellent impact resistance and heat resistance can be prepared. In particular, the high molecular weight coasel rubber-modified phenolic hardener of the present invention can be used as a raw material for epoxy powder coatings having good mechanical properties and storage properties even at a temperature of 160 to 180 ° C. By using these properties, powders for coil springs of epoxy powder coatings can be used. It can be widely used in the production of paints and thick film type powder coatings (medium-type powder coatings).

Hereinafter, the present invention will be described in detail with reference to the following Examples, which are not intended to limit the scope of the present invention.

Example 1

R-8828 resin (600g, EEW: 185-195 g / eq, KCC) was mixed with a corel (178g, EXL-2611) and dispersed for 2 hours at a temperature of 80 ~ 90 ℃ and then heated to 120 The solution was kept at a temperature of ˜130 ° C. for about 2 hours, and 2,2-bisphenol-A (1170 g) and ethyltriphenylphosphonium bromide (2.9 g, diluted with 50% MeOH) were added to the solution at a temperature of 100 ° C. . After the solution was allowed to react at a temperature of 160 to 170 ° C. for 5 hours, when the melt viscosity of the solution was 3.3 poise (150 ° C.), 2-methylimidazole (44 g) was added thereto, followed by sufficient stirring. A rubber modified phenol hardener was obtained.

Hydroxyl equivalent: 254

Melt Viscosity: 3.4 Poise (150 ℃, Cone & Plate Viscometer)

Softening Point: 88.0 ℃ (mettler, 2 ℃ .min / 90 ℃)

Example 2

R-8828 resin (600g, EEW: 185-195 g / eq, KCC product) was mixed with a corel (140g, KM-334 product), dispersed for 2 hours at a temperature of 80 ~ 90 ℃ and then heated to 120 The solution was kept at a temperature of ˜130 ° C. for about 2 hours, and 2,2-bisphenol-A (747 g) and ethyltriphenylphosphonium bromide (1.9 g, diluted with 50% MeOH) were added to the solution at a temperature of 100 ° C. After reacting for 5 hours at a temperature of 160 to 170 ° C., when the melt viscosity of the solution reaches about 22 poises (150 ° C.), 2-methylimidazole (34 g) is added and sufficiently stirred to coarse rubber-modified phenol. A hardener was obtained.

Hydroxyl equivalent: 410 g / eq

Melt Viscosity: 22.1 Poise (150 ° C, Cone & Plate Viscometer),

Softening Point: 105.0 ℃ (mettler, 2 ℃ .min / 90 ℃)

Example 3

Coacell (140g, EXL) in a resin mixed with R-8828 resin (600g, EEW: 185-195 g / eq, KCC) and aliphatic epoxy resin EX-252 (84g, EEW: 215 g / eq, Nagase Chemical) -2655 product) was added and dispersed and reacted at a temperature of 80 to 90 DEG C. Then, 2,2-bisphenol-A (843 g) and 2-ethyl-4-methylimidazole (0.84 g, 50% MeOH) were added to the solution. Diluted) was added at a temperature of 100 ° C. and reacted for 5 hours at a temperature of 160 to 170 ° C., when the melt viscosity of the solution reached about 8.0 poise (150 ° C.), 2-methylimidazole (46 g) Was added and the mixture was sufficiently stirred to obtain a corel rubber-modified phenol curing agent.

Hydroxyl equivalent: 407

Melt Viscosity: 8.1 Poise (150 ℃, Cone & Plate Viscometer),

Softening Point: 93.0 ℃ (mettler, 2 ℃ .min / 90 ℃)

Comparative Example 1

2,2-bisphenolA (1170g) and ethyltriphenylphosphonium bromide (2.9g, diluted with 50% MeOH) in R-8828 resin (600g, EEW: 185-195g / eq, KCC) At a temperature of 160 to 170 ° C. for 3 hours, and when the melt viscosity of the solution reached about 2.8 poise (150 ° C.), 2-methylimidazole (44 g) was added and stirred sufficiently. A curing agent was prepared.

Hydroxyl equivalent: 211

Melt Viscosity: 2.8poise (150 ℃, Cone & Plate Viscometer)

Softening Point: 82.0 ℃ (mettler, 2 ℃ .min / 70 ℃)

Comparative Example 2

2,2-bisphenol-A (747 g) and ethyltriphenylphosphonium bromide (1.9 g, diluted with 50% MeOH) in R-8828 resin (600 g, EEW: 185-195 g / eq, KCC) At a temperature of 160 to 170 ° C. for 3 hours, and when the melt viscosity of the solution reached about 16.5 poise (150 ° C.), 2-methylimidazole (34 g) was added and stirred sufficiently. A curing agent was prepared.

Hydroxyl equivalent: 407

Melt Viscosity: 16.7 Poises (150 ° C, Cone & Plate Viscometer),

Softening Point: 101.0 ℃ (mettler, 2 ℃ .min / 90 ℃)

Experimental Example

Using the phenol curing agent obtained in Examples 1 to 3 and Comparative Examples 1 to 2 to prepare a paint in the composition ratio shown in Table 1 below, after coating (250 ℃ × 1 hour) to preheated specimens and cured coating film thickness of 400 ± 50 After preparing the coating film specimens having a ㎛, the physical properties of each were measured and shown in Table 2 below.

Classification (% by weight) Paint Example 1 Paint example 2 Paint example 3 Paint example 4 Paint example 5 Nolock Epoxy Resin ¹ 50 50 50 50 50 Polyester resin ² 50 50 50 50 50 Example 1 Curing Agent 15 - - - - Example 2 Curing Agent - 25 - - - Example 3 Curing Agent - - 25 - - Comparative Example 1 Curing Agent - - - 15 - Comparative Example 2 Curing Agent - - - - 25 Improving Flow ³ 1.0 1.0 1.0 1.0 1.0 Curing accelerator ⁴ 0.1 0.1 0.1 0.1 0.1 Benzoin 0.5 0.5 0.5 0.5 0.5 Titanium dioxide 40 40 40 40 40 Corporation 1. N8039 (epoxy equivalent: 810-850): KCC product 2. N8070 (epoxy equivalent: 1700-2100): KCC product 3. PV-5: Wally's Products 4. BTPC (Butyltriphenyl Phosphonium Chloride): manufactured by Kamconsub

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Condition Exterior ○ ○ ○ ○ ○ Visual judgment Flexure ○ ○ ○ ○ ○ 5 ° (-10 ° C) Impact 10J 10J 12J 6J 5J Gardner test Changes over time during storage stability 5% 3% 3% 19% 17% 40 ℃ × 1 week change in hardenability (%) ○: good

As described above, the high molecular weight corel rubber-modified phenolic hardener of the present invention can be used as a raw material for epoxy powder coatings having good mechanical properties and storage properties even at low temperatures, and by using such properties, powder coatings for coil springs and thick-film powder coatings ( Heavy powder coatings).

Claims (11)

In preparing high molecular weight corel rubber-modified phenol curing agent, 10 to 70 parts by weight of corel rubber resin is dispersed and reacted with respect to 100 parts by weight of a mixture of a low molecular weight epoxy compound or a low molecular weight epoxy compound, a noblock epoxy resin and an aliphatic epoxy resin to prepare a low molecular weight corel rubber modified epoxy resin; The addition of the accelerator in the content of 1 to 15% by weight in the total phenol curing agent composition after the addition reaction of the polyhydric phenol in the molar ratio of 1.0 to 4.0 and the low molecular weight corel rubber modified epoxy resin, the equivalent of the hydroxyl group 200 A method for producing a high molecular weight coasel rubber-modified phenol curing agent of ˜1,000 g / eq. The method according to claim 1, wherein the low molecular weight epoxy compound has an epoxy equivalent of 170 to 300 g / eq. The high molecular weight coasel rubber according to claim 1, wherein the noblock type epoxy resin is a cresol noblock type epoxy resin or a phenol noblock type epoxy resin having an epoxy equivalent of 170 to 300 g / eq and an average number of functional groups of 3 to 7. Method for producing a modified phenol hardener. The aliphatic epoxy resin according to claim 1, wherein the aliphatic epoxy resin is sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) iso Cyanurate, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol-A diglycidyl ether, ethylene, A method for producing a high molecular weight coasel rubber-modified phenol curing agent, which is selected from polyethylene glycol diglycidyl ether, propylene, polypropylene glycol diglycidyl ether, and derivatives thereof and has an epoxy equivalent of 120 to 400 g / eq. . The method according to claim 1, wherein the corel rubber resin has an average diameter of 300 to 20,000 mm 3. The method of claim 5, wherein the core portion of the corel rubber resin is a homopolymer or a copolymer of conjugated diene rubber, acrylic rubber, and silicone rubber. . The cell portion of the corel rubber resin is styrene, acrylate, methacrylate, acrylonitrile, acrylic acid, methacrylic acid, hydroxypropyl acrylate, hydroxyethyl acrylate, glycidyl. A method for producing a high molecular weight coasel rubber-modified phenol curing agent, characterized in that it is a homopolymer of acrylate and glycidyl methacrylate or a copolymer thereof. 8. The method for producing a high molecular weight coasel rubber-modified phenol curing agent according to claim 7, wherein the average molecular weight of the polymer constituting the cell portion is 10,000 to 250,000. The method of claim 1, wherein the dispersion reaction is carried out at a temperature of 50 to 150 ℃ for 2 to 4 hours. The method of claim 1, wherein the polyhydric phenol is 2,2-bis (P-hydroxyphenyl) propane, (2,4-dihydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, 2,2- Bis (3-isopropyl-4-hydroxyphenyl) propane, 2,2-bis (2-isopropyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) ethane, 1, 3-bis (3-methyl-4-hydroxyphenyl) propane, bis (4-hydroxy-2,6-dimethyl-3-methoxy) phenyl, 2,2-bis (4-hydroxyphenyl) propane, 4,4-dihydroxyphenyl, bis (4-hydroxy-3-chloronaphthyl) ether, bis (4-hydroxy-3-bromophenyl) ether, 1,1-bis (4-hydroxyphenol ) -2-phenylethane and 2,4-bis (P-hydroxyphenyl) -4-methylphene. A method for producing a high molecular weight coasel rubber-modified phenol curing agent. The method of claim 1, wherein the accelerator is selected from imidazoles, phosphines, tertiary amines, quaternary ammonium salts and quaternary phosphonium salts.