JP3611385B2 - Resin composition for paint - Google Patents

Description

【００２０】
【表２】

【００２１】
比較例１
実施例１の前半において、３ＡＰＯＬとＤＢＡを同時に一括して加えて１段階で反応させる以外、同様な操作を行なった。
すなわち、実施例１に用いたものと同じフラスコに、ビスフェノールＡ−ジグリシジルエーテル系エポキシ樹脂（エポキシ当量１０００ｇ／ｅｑ ）１０００部を仕込み、トルエン ６００部及びシクロヘキサノン ４００部を加え溶解させる。次に、トルエンにて還流脱水後、窒素雰囲気下、３ＡＰＯＬ ３０部とＤＢＡ ５２部を加え １００℃にて反応させ、４時間後と５時間後にそれぞれ反応溶液をサンプリングし、その粘度が一定になったことを確認した後、室温まで冷却し、ＩＰＡ １０４部及びＭＥＫ ２１０部を加えて希釈し、固形分 ４５％及び粘度 ２２ ｐｏｉｓｅ の樹脂溶液を得た。この樹脂溶液中、第二級アミンと第三級アミンの存在の有無をフーリエ変換式赤外線分光機にて確認し、それらの結果を表５に示す。
更に、実施例１の後半において、この樹脂溶液を用いる以外は全く同様に操作し、塗料、更には試験板を得た。この試験板の塗膜物性を実施例１の後半に記載の方法により評価し、それらの結果を表７に示す。
【００２２】
比較例２
実施例１の前半において、３ＡＰＯＬとＤＢＡを逆の順序で加えて２段階で反応させる以外、同様な操作を行なった。
すなわち、実施例１に用いたものと同じフラスコに、ビスフェノールＡ−ジグリシジルエーテル系エポキシ樹脂（エポキシ当量 １０００ ｇ／ｅｑ ）１０００部を仕込み、トルエン ６００部及びシクロヘキサノン ４００部を加え溶解させる。次に、トルエンにて還流脱水後、窒素雰囲気下、ＤＢＡ ５２部を加え １００℃で反応させ（一段目反応）、４時間後と５時間後にそれぞれ反応溶液をサンプリングし、その粘度が一定になったことを確認した後、６０℃まで冷却後、３ＡＰＯＬ ３０部を加え、再び １００℃にて反応させ（二段目反応）、４時間後と５時間後にそれぞれ反応溶液をサンプリングし、その粘度が一定になったことを確認した後、室温まで冷却し、ＩＰＡ １０４部及びＭＥＫ ２１０部を加えて希釈し、固形分 ４５％及び粘度 ２１ ｐｏｉｓｅ の樹脂溶液を得た。この樹脂溶液中、第二級アミンと第三級アミンの存在の有無をフーリエ変換式赤外線分光機にて確認し、それらの結果を表５に示す。
更に、実施例１の後半において、この樹脂溶液を用いる以外は全く同様に操作し、塗料、更には試験板を得た。この試験板の塗膜物性を実施例１の後半に記載の方法により評価し、それらの結果を表７に示す。
【００２３】
【表３】

【００２４】
【表４】

【００２５】
【表５】

【００２６】
【表６】

【００２７】
【表７】

【００２８】
【表８】

【００２９】
【発明の効果】
本発明によれば、得られる樹脂組成物を用いた一液性常温乾燥型塗料は、変性剤となる多官能アルカノールアミンと第二級アルキルアミンの性能を引き出し、とりわけ密着性と耐水性にバランスが取れた良好な物である。[0001]
BACKGROUND OF THE INVENTION
In the present invention, in modifying a raw material resin for paint using an epoxy resin, by introducing a polyfunctional alkanolamine and a secondary alkylamine as a modifier into a suitable part of the molecular chain in the epoxy resin, The present invention relates to a one-component room-temperature drying paint resin composition for improving water resistance and adhesion, and the resin composition is useful for building material primers, automobile parts and the like.
[0002]
[Prior art]
Conventionally, epoxy resins obtained by the reaction of a compound having a phenolic hydroxyl group and epichlorohydrin have a reactive epoxy group, and therefore are crosslinked and polymerized with amine, polyamide, dibasic acid, etc. Widely used for resins and the like.
By the way, in general, the properties of a polymer are greatly influenced by the molecular weight, molecular weight distribution, steric structure, type of functional groups at side chains and terminals, and the like. For example, as disclosed in Eiichi Kobayashi et al., 40th Annual Meeting of the Society of Polymer Science, Lecture Number III-4-19 (1991), it consists of benzenedithiol and divinylbenzene and has almost the same chain distribution. In the polymers having the thermal properties, those whose molecular ends are —SH or —CH═CH ₂ and those end-capped with thiophenol and styrene are quite different.
[0003]
Epoxy resins have also been modified in performance by introducing various functional groups. As a means for introducing the functional group, a polyfunctional alkanolamine or a secondary alkylamine is often used.
Specifically, in order to form hydrogen bonds with hydroxyl groups and water molecules on the surface of the metal material, and to improve the adhesion of the coating film, a primary hydroxyl group not found in bisphenol A type epoxy resin is introduced by alkanolamine, In addition, in order to improve the water resistance, it has been attempted to introduce an alkyl group with an alkylamine or to use an alkanolamine and an alkylamine in combination so as to have both adhesion and water resistance.
However, the coating film obtained in any case has a sufficient balance between adhesion and water resistance, such as improved adhesion but insufficient water resistance and poor adhesion after water resistance test. It was very difficult to take, and I had to sacrifice one or the other.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide an epoxy resin for a one-component room-temperature drying paint that has both adhesiveness and water resistance in the obtained coating film.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that polyfunctional alkanolamine (B), secondary alkylamine (C), and further, the reaction of polyfunctional alkanolamine (B) with an epoxy group. We focused on the reactivity of the secondary amine produced by the reaction to the epoxy group.
That is, in modifying the epoxy resin, when the polyfunctional alkanolamine (B) and the secondary alkylamine (C) are reacted simultaneously with the epoxy resin as in the prior art, the polyfunctional alkanolamine (B) is bonded to the epoxy group. Next, the secondary alkylamine formed by reacting the polyfunctional alkanolamine (B) and the secondary alkylamine (C) with the epoxy group reacts with the epoxy group remaining in the system. . And it becomes the epoxy resin modified product which superposition | polymerization complete | finishes by the secondary alkanolamine terminal produced | generated by reacting a polyfunctional alkanolamine (B) and secondary alkylamine (C) with an epoxy group.
For this reason, in this modified epoxy resin, the molecular end group that greatly affects the properties of the polymer is the reaction of the skeleton derived from the secondary alkylamine (C) or the epoxy group and the polyfunctional alkanolamine (B). It is the produced | generated secondary alkanolamine, This secondary alkanolamine impairs the water resistance of an epoxy resin.
[0006]
Therefore, when the epoxy resin (A) is modified with the polyfunctional alkanolamine (B) and the secondary alkylamine (C), first, the epoxy resin (A) is modified only with the polyfunctional alkanolamine (B), Next, by modifying the epoxy group remaining in the system with a secondary alkylamine (C), the resulting epoxy resin modified product has its molecular terminal completely derived from the secondary alkylamine (C). The present inventors have found the fact that only the substituents of
[0007]
That is, the present invention provides a resin composition comprising an epoxy resin (A) having an epoxy equivalent of 300 to 3000 g / eq, a polyfunctional alkanolamine (B) and a secondary alkylamine (C). Component A and Component B are reacted with each other in a range of 0.2 to 0.9 equivalent ratio of active hydrogen in Component B to the group (first stage reaction), Component C is added and reacted so that the active hydrogen in C is in the range of 0.1 to 0.8 equivalent ratio and the total of active hydrogen in component B and component C is 1.0 equivalent ratio (two-stage A one-component room-temperature drying paint resin composition characterized in that the epoxy resin (A) is bisphenol A-diglycidyl ether or bisphenol F-diglycidyl ether. What to do is there.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the epoxy resin (A) means bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether, novolac glycidyl ether, hexahydrophthalic acid glycidyl ester, dimer acid glycidyl ester, tetraglycidylaminodiphenylmethane, 3,4 -Epoxy-6-methylcyclohexyl methyl carboxylate, triglycidyl isocyanurate, 3,4-epoxycyclohexyl methyl carboxylate, polypropylene diglycidyl ether, polybutadiene or polysulfide modified at both ends diglycidyl ether, etc. Bisphenol A-diglycidyl ether and bisphenol F-diglycidyl ether are preferred. These may be used alone or in combination of two or more.
The epoxy equivalent is preferably in the range of 300 to 3000 g / eq. When this epoxy equivalent is less than 300 g / eq, the corrosion resistance of the resulting coating film is deteriorated, and when it exceeds 3000 g / eq, the viscosity increases as the molecular weight increases, making handling difficult.
[0009]
In the present invention, the polyfunctional alkanolamine (B) is an amine having two or more active hydrogens in one molecule. Specific examples include 3-aminopropanol, isopropanolamine, monopropanolamine, monobutanolamine, monoethanolamine and the like. The secondary alkylamine (C) in the present invention is an amine having one active hydrogen per molecule and the other substituted with an alkyl group. Specific examples include diethylamine, dibutylamine, diisobutylamine, di-sec-butylamine, N-ethyl-1,2-dimethylpropylamine, N-methylhexylamine and the like.
[0010]
When producing the resin composition in the present invention, the epoxy resin (A) and the polyfunctional alkanolamine (B), and further the secondary alkylamine (C) are blended at a specific equivalent ratio in two stages. It is essential to react. That is, first, the epoxy group in the epoxy resin (A) and the active hydrogen in the polyfunctional alkanolamine (B) are reacted so that the epoxy group remains (first-stage reaction). The active hydrogen in the secondary alkylamine (C) is reacted (second stage reaction).
At that time, the compounding amount of each component is 0.2 to 0.9 equivalent of active hydrogen in polyfunctional alkanolamine (B) with respect to 1.0 equivalent of epoxy group in epoxy resin (A) in the first stage reaction. In the second stage reaction, the active hydrogen in the secondary alkylamine (C) is in the range of 0.1 to 0.8 equivalents relative to 1.0 equivalent of the epoxy group in the epoxy resin (A). In the two-stage reaction, the total of active hydrogen in the polyfunctional alkanolamine (B) and secondary alkylamine (C) with respect to the epoxy group in the epoxy resin (A),
That is, {(total of active hydrogen in component B and component C) / (epoxy group in component A)} (equivalent ratio) is 1.0.
[0011]
However, in the first stage reaction, when the active hydrogen in component B is less than 0.2 equivalent ratio to the epoxy group in component A, the final molecular weight of the composition is low, and the adhesion of the resulting coating film is poor, If the ratio exceeds 0.9 equivalent ratio, the adhesion is improved, but the final molecular weight is increased and the handling of the paint is deteriorated, the amount of component C added is reduced, and the water resistance is not improved. In the second stage reaction, when the active hydrogen in the component C is less than 0.1 equivalent ratio with respect to the epoxy group in the component A, the adhesion of the resulting coating is improved but the water resistance is not improved. If it exceeds 0.8 equivalent ratio, the adhesion is poor. Furthermore, in these two-step reactions, when the total of active hydrogen in component B and component C is less than 1.0 equivalent ratio with respect to the epoxy group in component A, the epoxy group that is a reactive substituent remains, The composition is inferior in stability over time, and if it exceeds 1.0 equivalent ratio, residual amine which is a low molecular weight substance is present and the physical properties of the coating film are deteriorated.
[0012]
In the present invention, when the resin composition (resin solution) is produced by the two-stage reaction as described above, in the first stage, the epoxy resin (A) is dissolved in a solvent, and the polyfunctional alkanolamine (B ) In an atmosphere of nitrogen at 70 to 150 ° C. for 4 to 10 hours to polymerize, and diluted with a solvent to a viscosity of about 5 to 70 poise to obtain a resin solution. In the second stage, the secondary alkylamine (C) is added to this, and the reaction is carried out under the same conditions as in the first stage, and diluted with a solvent to obtain the desired resin solution. In this case, examples of the solvent include toluene, xylene, cyclohexanone, methyl ethyl ketone, isopropyl alcohol, n-butyl alcohol, propylene glycol monomethyl ether acetate and the like.
[0013]
In the present invention, a one-component room-temperature drying paint is produced by a known method, that is, adding a rust preventive pigment, an extender pigment, a leveling agent and various additives to the above resin solution, a disper, a sand mill, What is necessary is just to knead and disperse | distribute using a ball mill etc.
In addition, as a coating method, the paint obtained as described above is applied directly or after pre-painting treatment by a general method such as brush coating, spray coating, and various coater coatings. Applicable materials include various metal materials such as cold rolled steel sheet, galvanized steel sheet, alloyed galvanized steel sheet, chrome plated steel sheet, aluminum plated steel sheet, tin plated steel sheet, lead plated steel sheet, nickel plated steel sheet, aluminum plate, titanium Examples include plates, stainless steel plates; plastics materials; inorganic materials.
[0014]
【Example】
Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. In the following, “part” and “%” are based on weight. In addition, hereinafter, the polyfunctional alkanolamine (B), secondary alkylamine (C), and some of the solvents used are indicated by the following abbreviations.
3APOL: 3-aminopropanol, MEA: monoethanolamine; DBA: dibutylamine; IPA: isopropyl alcohol, MEK: methyl ethyl ketone: PMA: propylene glycol monomethyl ether acetate.
Furthermore, in Tables 1 to 4, the type of epoxy resin (A) is indicated by the following abbreviation.
BP-A: bisphenol A-diglycidyl ether type epoxy resin BP-F: bisphenol F-diglycidyl ether type epoxy resin
Example 1
A glass four-necked flask (with a stirrer, thermometer, external heater, condenser, condenser and nitrogen inlet tube) was charged with 1000 parts of bisphenol A-diglycidyl ether epoxy resin (epoxy equivalent 1000 g / eq), toluene. Add 600 parts and 400 parts cyclohexanone and dissolve. Next, after refluxing dehydration with toluene, under nitrogen atmosphere, 23 parts of 3APOL (active hydrogen equivalent 37.5 g / eq) was added and reacted at 100 ° C. (first stage reaction). After 4 hours and 5 hours, respectively. The solution was sampled, and after confirming that the viscosity became constant, it was cooled to 60 ° C. To this solution, 52 parts of DBA (active hydrogen equivalent: 129 g / eq) was added and reacted again at 100 ° C. (second stage reaction). The reaction solution was sampled after 4 hours and 5 hours, respectively, and the viscosity was kept constant. After confirming that it was cooled, it was cooled to room temperature and diluted by adding 141 parts of IPA and 282 parts of MEK to obtain a resin solution having a solid content of 45% and a viscosity of 23 poise.
The presence or absence of secondary amine and tertiary amine in this resin solution was confirmed with a Fourier transform infrared spectrometer, and the results are shown in Table 5. At this time, the absorption peak at a wave number of 1200 cm ⁻¹ indicates the presence of a secondary amine, and the shift of the peak to a lower wave number indicates the presence of a tertiary amine.
[0016]
Further, 200 parts of this resin solution, 80 parts of titanium oxide (R920: trade name, manufactured by DuPont) and 10 parts of aluminum phosphomolybdate (manufactured by Kikuchi Dye Industry Co., Ltd.) and a solvent (toluene: cyclohexanone: MEK: IPA) = 50: 10: 20: 20 weight ratio) 60 parts were blended and kneaded and dispersed using a sand mill to obtain a paint. At this time, the ratio of the total pigment and the solid content in the resin solution is 1.0 / 1.0 weight ratio, the ratio of titanium oxide and aluminum phosphomolybdate is 80/10 weight ratio, The amount is adjusted so that the viscosity of the resulting paint is 90-110 seconds (Ford Cup # 4).
[0017]
This paint is applied to a zinc phosphate-treated steel plate (150 mm × 70 mm × 0.8 mm thickness) by air spray, and the film thickness is adjusted to 20 μm. After painting, the steel plate is left at 20 ° C. for 7 days, dried and used as a test plate. The coating film physical properties of this test plate were evaluated by the following methods, and the results are shown in Table 6.
-Adhesiveness: According to the cross cut test of JIS-K-5400 (1990.8.5.2), the remaining number from the cross cut 100 was determined.
-Water resistance: Cover the back and side of the test plate with polyester tape and immerse it in pure water at 40 ° C for 5 days. Then, the blister generation | occurrence | production state of a coating-film surface is observed visually, and water resistance is evaluated in five steps.
◎ ・ ・ No abnormality, ○ ・ ・ 1-5 pieces, △ ・ ・ 5-10 pieces, XX ・ ・ 10-20 pieces XX ・ ・ Full surface blister ・ Adhesion after immersion in water: Test plate evaluated for water resistance Within 30 minutes, JIS-K-5400
According to the cross cut test of (1990.8.5.2), the remaining number from the cross cut 100 was determined.
[0018]
Examples 2-7 and Comparative Examples 3-8
In Example 1, the same operation was carried out except that the types and amounts of the respective components were changed as shown in Tables 1 to 4, and a resin solution, a paint, and a test plate were obtained.
The presence or absence of secondary amine and tertiary amine in this resin solution was confirmed with a Fourier transform infrared spectrometer, and the results are shown in Table 5.
The coating film physical properties of this test plate were evaluated by the method described in the latter half of Example 1, and the results are shown in Tables 6-8.
[0019]
[Table 1]

[0020]
[Table 2]

[0021]
Comparative Example 1
In the first half of Example 1, the same operation was performed except that 3APOL and DBA were added simultaneously and reacted in one step.
That is, in the same flask as used in Example 1, 1000 parts of bisphenol A-diglycidyl ether-based epoxy resin (epoxy equivalent 1000 g / eq) is charged, and 600 parts of toluene and 400 parts of cyclohexanone are added and dissolved. Next, after reflux dehydration with toluene, under nitrogen atmosphere, 3 parts of APOL 30 parts and 52 parts of DBA were added and reacted at 100 ° C., and the reaction solution was sampled after 4 hours and 5 hours, respectively, and the viscosity became constant. After confirming this, the mixture was cooled to room temperature and diluted by adding 104 parts of IPA and 210 parts of MEK to obtain a resin solution having a solid content of 45% and a viscosity of 22 poise. The presence or absence of secondary amine and tertiary amine in this resin solution was confirmed with a Fourier transform infrared spectrometer, and the results are shown in Table 5.
Furthermore, in the latter half of Example 1, the same operation was carried out except that this resin solution was used, and paints and further test plates were obtained. The coating film properties of this test plate were evaluated by the method described in the latter half of Example 1, and the results are shown in Table 7.
[0022]
Comparative Example 2
In the first half of Example 1, the same operation was performed except that 3APOL and DBA were added in the reverse order and reacted in two stages.
That is, 1000 parts of bisphenol A-diglycidyl ether epoxy resin (epoxy equivalent 1000 g / eq) is charged into the same flask used in Example 1, and 600 parts of toluene and 400 parts of cyclohexanone are added and dissolved. Next, after refluxing dehydration with toluene, 52 parts of DBA was added in a nitrogen atmosphere and reacted at 100 ° C. (first stage reaction). After 4 hours and 5 hours, the reaction solution was sampled, and the viscosity became constant. After confirming that, 30 parts of 3APOL was added after cooling to 60 ° C., and reacted again at 100 ° C. (second stage reaction). The reaction solution was sampled after 4 hours and 5 hours, respectively. After confirming that the temperature became constant, the mixture was cooled to room temperature and diluted by adding 104 parts of IPA and 210 parts of MEK to obtain a resin solution having a solid content of 45% and a viscosity of 21 poise. The presence or absence of secondary amine and tertiary amine in this resin solution was confirmed with a Fourier transform infrared spectrometer, and the results are shown in Table 5.
Furthermore, in the latter half of Example 1, the same operation was carried out except that this resin solution was used, and paints and further test plates were obtained. The coating film properties of this test plate were evaluated by the method described in the latter half of Example 1, and the results are shown in Table 7.
[0023]
[Table 3]

[0024]
[Table 4]

[0025]
[Table 5]

[0026]
[Table 6]

[0027]
[Table 7]

[0028]
[Table 8]

[0029]
【The invention's effect】
According to the present invention, the one-component room-temperature drying paint using the resulting resin composition draws out the performance of polyfunctional alkanolamine and secondary alkylamine as modifiers, and in particular, balances adhesion and water resistance. It is a good product that can be removed.

Claims (2)

In a resin composition comprising an epoxy resin (A) having an epoxy equivalent of 300 to 3000 g / eq, a polyfunctional alkanolamine (B) and a secondary alkylamine (C), first, in the component B with respect to the epoxy group in the component A In the range of 0.2 to 0.9 equivalent ratio of active hydrogen, component A and component B are reacted (first stage reaction). Next, the active hydrogen in component C is reacted with the epoxy group in component A. The reaction is performed by adding Component C so that the total of active hydrogen in Component B and Component C is in the range of 0.1 to 0.8 equivalent ratio, and the equivalent ratio is 1.0 (second stage reaction). A one-component room-temperature drying paint resin composition. 2. The one-component room-temperature drying paint resin composition according to claim 1, wherein the epoxy resin (A) is bisphenol A-diglycidyl ether or bisphenol F-diglycidyl ether.