JPS5844431B2 - Netsukokaseikokokaibuntoriyousoseibutuno tosouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a coating method for a thermosetting high-solids coating composition that can be sprayed at a coating temperature of about 70°C or lower, and furthermore, a coating method for spraying at a coating temperature of about 70°C or less, and a method for spraying the coating composition during or after coating. The present invention relates to a coating method for a thermosetting high solids coating composition that prevents solvent vapor from dispersing into the atmosphere.

In recent years, as air pollution has become more serious and global resource shortages have become more serious, the paint industry is also under pressure to take measures to address these problems.

Increasing the concentration of the paint (reducing the volatile solvent content) is an extremely effective means of simultaneously solving these two problems.

This is because by increasing the concentration of the paint, the amount of solvent volatilized into the atmosphere during the paint film formation process is significantly reduced, and at the same time, the amount of solvent that is not a component of the final formed paint film is significantly reduced, resulting in resource conservation of paint. Dogs also contribute to this.

As a result of repeated research into methods for increasing the concentration of paint and preventing the release of solvent into the atmosphere, the present inventors applied a high solids content type paint composition as described in the claims above, and further developed By removing the solvent vapor generated during the film formation process using a gas-liquid contact method, the amount of solvent used can be reduced by approximately 1/2 to 1/2 without impairing the performance of currently used thermosetting paints. We have found a more economical treatment method that can reduce the amount of solvent to 7 and prevent the solvent from dispersing into the atmosphere.

In other words, in the case of currently used thermosetting paints, when spraying is applied, in order to achieve a viscosity of 100 to 50 inches, which is suitable for painting, the spraying method is applied to 100 parts by weight of the vehicle solid in the paint. In contrast, in the composition of the present invention, the amount of solvent used is 80 to 20 parts by weight, which is about 1/2 to 1/7.
It is possible to reduce the

Furthermore, by using a coating composition containing a specific solvent composition as in the present invention, there is an effect of extremely reducing the amount of solvent volatilized, particularly in the painting process to the coating film forming process.

This makes the gas-liquid contact process more economical and
In order to drastically reduce the amount of solvent in processes where the exhaust air volume is large (and it is difficult to treat volatile solvents by incineration, adsorption, absorption methods, etc.), the present invention is effective in conjunction with the reduction in the absolute amount of solvent. It makes the effect even bigger.

Generally, the means to increase the concentration of paint is to lower the molecular weight of the resin component of the vehicle used, reduce the amount of aromatic raw materials, and use more aliphatic raw materials in order to weaken the cohesive force and increase the solubility of the resin. It is possible to do so.

However, if the purpose is simply to obtain a vehicle with low viscosity, it can be achieved by lowering the molecular weight by reducing the dibasic acid ratio of the polyester (alkyd) resin currently used for ordinary paints. However, the polyester resin thus obtained has poor curability and cannot exhibit sufficient performance as a thermosetting paint.

As a result of intensive research into polyester resins that have low viscosity and can form good coating films, the inventors of the present invention have found that the dibasic acid ratio is 0.95 to 1.00 for ordinary resins. .5
A polyester resin with an extremely small hydroxyl group content of 0 to 0.65 and an extremely high hydroxyl equivalent of 120 to 250, compared to the 500 to 1,000 hydroxyl equivalent of normal products, is modified with a small amount of diisocyanate compound. It has been found that a modified polyester resin with low viscosity and excellent curability can be obtained by this method.

In other words, such polyester resins with low molecular weight and high hydroxyl group content tend to cause cissing, dents, etc. on the painted surface (and have not been used in the past because it is impossible to obtain a practical paint.

However, noting that this polyester resin has a low viscosity and a fairly high curability, we considered applying it to a paint vehicle that prevents cissing and dents on the painted surface and can be applied at high concentrations.

As a result of extensive research into ways to prevent cissing, dents, etc., we surprisingly found that by modifying the polyester resin with a very small amount of diisocyanate compound, we were able to completely prevent the occurrence of paint film defects such as cissing and denting. It has been found that a vehicle can be obtained which exhibits high curability and provides a coating film that is sufficiently durable for practical use.

Furthermore, it has been found that there is almost no increase in the viscosity of the solution due to modification with this diisocyanate compound, and the solution can be sufficiently used for the purpose of the present invention.

That is, the present invention provides (1) (a) a dicarboxylic acid, a polyhydric alcohol, and, if necessary, a monocarboxylic acid, in which the dicarboxylic acid/polyhydric alcohol (molar ratio) (dibasic acid ratio) is 0. 5
0 to 0.65, a hydroxyl equivalent of 120 to 250, and modified with 2 to 5 parts by weight of an aliphatic or aromatic diisocyanate compound per 100 parts by weight of a polyester resin containing 10 to 25% by weight of phenyl groups. 80 to 60% by weight of a modified polyester resin, and (b) the main component is hexakisalkoxymethylmelamine, in which an average of 2 to 6 of R in the following chemical formula is an alkyl group having 2 to 4 carbon atoms, and the remainder is a methyl group. 20 to 40% by weight of a melamine resin, and if necessary, a melamine modified with an alcohol having 1 to 4 carbon atoms in which bound formaldehyde is 5.5 mol or less per 1 mol of melamine. (d) 0.05 to 1.00 weight part of aliphatic or aromatic sulfonic acid or its amine salt per ioo weight part of the mixture formed by blending the resin in a proportion of 1/2 weight % or less of the above component (b). and (e) the components are simultaneously dissolved in 100 parts by weight of the mixture, and the solubility in water at 20° C. is 0.5% by weight.
or more, and the vapor pressure at 20°C is 90 mmHg or less, and the sum of the partial pressures of each solvent is 35
imHg or less, and if necessary, a thermosetting high solids coating composition containing 80 to 20 parts by weight of a solvent containing 10% by weight or less of a water-insoluble solvent. , a coating method for a thermosetting high-solids coating composition, characterized in that spraying is performed at a coating temperature of about 70°C.

and (2) the thermosetting high solids coating composition is sprayed at a coating temperature of about 70°C or less, and the spraying is performed to remove the vapor of the solvent that evaporated or volatilized during and/or after the coating. This is a coating method for a thermosetting high solids coating composition, which is characterized by recovering the vapor by a liquid contact method and preventing the vapor from dissipating into the atmosphere.

In the present invention, the hydroxyl equivalent means the gr number of the polyester resin per mole of hydroxyl groups, and the phenyl group content means the weight percent of benzene nuclei in the polyester resin.

In the polyester resin of the present invention, the dibasic acid ratio is 0.5
If it is less than 0, the molecular weight is too low and the curability is insufficient, and even if it is modified with a diisocyanate compound, it is difficult to completely eliminate the scratches, scratches, and dents that occur on the coated surface.

On the other hand, if it exceeds 0.65, the viscosity becomes high and the object of the present invention cannot be fully achieved.

Furthermore, if the amount of hydroxyl groups, which are functional groups, is greater than 250 in terms of hydroxyl equivalent, the curability will be poor, and if it is less than 120, coating film defects such as repellency and dents cannot be eliminated.

In addition, in order to impart the necessary hardness to the coating film, 10%
It is necessary to contain ˜25% by weight of phenyl groups.

If the phenyl group content is less than 10%, the resin will be too soft and the coating film will lack hardness.

Moreover, more than 25% is unnecessary and undesirable because it increases the viscosity.

As a method for producing polyester resin, commonly used melt condensation methods, azeotropic condensation methods, etc. can be used.

The reaction temperature is preferably 160 to 240°C.

To modify urethane, add a diisocyanate compound to a polyester resin or a solution of it dissolved in a solvent that does not contain hydroxyl groups to a solid content of 60% by weight or more, and add 50% to 1% solids.
The reaction may be carried out at 20°C for about 1 to 3 hours.

Diisocyanate compounds that can be used include aromatic and aliphatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate.

The amount of modification of diisocyanate compound is polyester resin i
It is preferable that the amount is 2 to 5 parts by weight per part by weight of oo, and if it is less than 2 parts by weight, nicks and dents are likely to occur, and if it is more than 5 parts by weight, the viscosity of the paint will be high and the thermal stability will be reduced. do not have.

The melamine resin (component (b)) used as a curing agent is represented by the general formula above, and this hexakisalkoxymethyl melamine has a significantly lower viscosity than ordinary melamine resins, and is suitable for paints. This is preferable for increasing the concentration.

Hexakismethoxymethyl melamine, which has been well known for a long time, has a large cohesive force when combined with the above modified polyester resin, and it is difficult to use because it tends to cause coating defects such as chips and dents on the painted surface. .

However, it has been found that by substituting a portion of the methoxy groups of the melamine resin with an alcohol having 2 to 4 carbon atoms as in the present invention, this drawback can be compensated for and the viscosity can be lowered.

However, the melamine resin (component (b)) used in this application has low reactivity and requires a curing catalyst, and the conventional alkyd resins have poor stability during heating and can be used in paints with high concentrations. Hot spraying, which is an effective method for coating, cannot be applied, but by using it together with a modified polyester resin such as the one of the present invention, stability during heating is improved, and the curing properties are improved. In order to improve the results, even when a conventionally used melamine resin (component (C)) is used within the scope of the present invention, hot spraying can be carried out sufficiently at a temperature of 70° C. or lower.

In addition, although the melamine resin used in the present invention as component (C) is not necessarily necessary, baking is an effective means especially when it is desired to lower the temperature, and if the amount used is within the scope of the present invention, it will be described. It won't take away from the effects you've achieved.

Sulfonic acid type curing catalysts, which are strong acids, are particularly effective, and in this case, the appropriate amount to be used is 0.05 to 1.00 parts by weight based on 100 parts by weight of the total resin components.

In other words, if the amount is less than 0.05 part, the curability is poor;
．． If the amount exceeds 0.00 parts, the heating stability deteriorates, making it difficult to apply hot spray.

The raw materials used to obtain the polyester resin used in the present invention are the same as those conventionally used.

That is, the dibasic acids include aromatic dicarboxylic acids or their anhydrides, such as phthalic acid, isophthalic acid, terephthalic acid, or their anhydrides; alicyclic dicarboxylic acids or their anhydrides, such as hexahydrophthalic acid, tetrahydrophthalic acid, and tetrachlorophthalic acid. acid, tetrabromophthalic acid, 3.
6-Nindomethylene-△4-tetrahydrophthalic acid, 3
・6-Nindo dichloromethylene Δ4-tetrahydrophthalic acid or its anhydride; Aliphatic dicarboxylic acid or its anhydride such as cono-phosphoric acid, maleic acid, adipic acid,
Examples include azelaic acid, sebacic acid, or anhydride thereof, and these can be used alone or in a mixture.

Examples of polyhydric alcohols include glycerin, trimethylolethane, 1) methyT:I-/l/propane, 1,2,6-hexanediol, pentaerythritol, etc. as 7/L/cols having a valence of 3 or more. Glycols include ethylene glycol, fluoropylene glycol, 1.
2-butanediol, ■2-bentanediol, 3methyl-1,2-butanediol, trimethylene glycol, β-butylene glycol, 2,4-bentanediol, 2,2 dimethyltrimethylene glycol, 2,2 −
Dimethyl-1,3-butanediol, 2,2-dimethyl-1,3-bentanediol, tetramethylene glycol, ■4-bentanediol, 3methyl-4,5-bentanediol, 1,4-hexanediol, 2.5-
Hexanediol, pentamethylene glycol, ■・5
-Hexanediol, hexamethylene glycol, etc. Monoepoxide compounds such as Cardura E can also be used as glycols.

These materials can be used alone or in mixtures.

As a monocarboxylic acid, it is saturated or unsaturated and has 6 or more carbon atoms.
18 fatty acids or their triglycerides, alkyl-substituted benzoic acids such as benzoic acid, methylbenzoic acid, and Pt-butylbenzoic acid can be used.

These materials can be used alone or in mixtures.

Triglycerides such as vegetable oils can also be used as monocarboxylic acids.

All methods conventionally used for producing polyester resins, such as melt condensation methods, azeotropic condensation methods, and combinations thereof, may be employed as appropriate.

The phenyl group is introduced into the polyester resin by using the aforementioned phenyl group-containing dicarboxylic acid and, if necessary, monocarboxylic acid.

Melamine resin modified with a mixed alcohol (fraction (b)) can be easily synthesized by ether-exchanging hexakismethoxymethylmelamine with an alcohol having 2 to 4 carbon atoms at 70° C. or lower in the presence of a strong acid.

The melamine resin (e) fraction contains most of the melamine resins conventionally used.

C2-CtS as aliphatic or aromatic sulfonic acid
C8 to C18 alkylsulfonic acids, benzenesulfonic acids, and organic amine salts thereof can be used.

The solvent (e) mainly consists of a water-soluble solvent, which makes the gas-liquid contact method economically possible in order to prevent the solvent vapor emitted during coating from dissipating into the atmosphere.

In this specification, water-soluble solvents are those having a solubility in water of 0.5% by weight or more at 20°C, and water-insoluble solvents are those having a solubility in water of 0.5% by weight at 20°C.
Refers to something smaller than % by weight.

The solubility of the solvent used in water at 20°C is 0.
less than 5% by weight, and the vapor pressure at 20°C is 90
If it is higher than imHg, the solubility of the solvent in water is low and the vapor pressure is high, so the absorption efficiency into the liquid by the gas-liquid contact method is extremely poor and it is not suitable for effective recovery. and the vapor pressure is 90
If it is larger than miHg, the amount of air discharged from the painting booth during spray painting is usually very low, resulting in poor absorption efficiency of the solvent into the liquid, and this is also not suitable.

Furthermore, the solubility is less than 0.5% by weight and the vapor pressure is 9.
If it is less than 0 miHg, the solubility of the solvent in water is low, and therefore the absorption efficiency is poor and it is not suitable.

Therefore, suitable solvents for use in the present invention have a solubility in water of 0.5% by weight or more at 20°C and a vapor pressure of 90 miHg or less at 20°C.

In the present invention, examples of solvents that are water-soluble and have a vapor pressure of 90 mmHg or less at 20°C include ethanol, n-
7” lopyl alcohol, isopropyl alcohol, n-
7” Alcohols such as methyl alcohol, isobutyl alcohol, secondary butanol, tertiary butanol, n-amyl alcohol, isoamyl alcohol, secondary amyl alcohol, tertiary amyl alcohol, cyclohexanol, ethylene glycol, phlopylene glycol, butylene glycol, etc. Solvents, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, methyl butyl ketone, ethyl butyl ketone, cyclohexanone, isophorone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol mono glycol ether solvents such as butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ether solvents such as dioxane, dimethyl dioxane, ethyl acetate, butyl acetate, isopropyl acetate, isobutyl acetate, secondary butyl acetate, ethylene acetate Ester solvents such as glycol monomethyl ether, ethylene glycol monoethyl acetate, and ethylene monobutyl acetate are suitable.

In order to use the above-mentioned solvents in accordance with the gist of the present invention, a combination in which the sum of the partial pressures of each solvent is 35 mmHg or less is appropriate.

If the sum of the partial pressures is 35 mmHg or more, the absorption efficiency of the liquid in the case of the gas-liquid contact method using a liquid mainly composed of water is usually extremely poor because the amount of air discharged from the paint booth during spray painting is extremely low. becomes.

In addition, if water-insoluble solvents such as doluol, kijirole, and petroleum-based high-boiling aromatics are contained in an amount exceeding 10% by weight, the absorption efficiency of liquid materials mainly composed of water will be significantly reduced. It deviates from the main idea.

In the coating composition of the present invention, like conventional coatings,
It can also be used as a clear paint or colored with appropriate dyes and pigments.

Additionally, additives such as flowability modifiers and color separation inhibitors can be used in the same manner as in conventional paints.

Gas-liquid contact methods that can be used in the present invention include scrubber method,
A spray bath method, a rotating disc method, a multi-stage column method, a bubble stirring method, etc. are suitable.

In either case, water or water combined with an appropriate drug can be used as the liquid material.

Using water as a liquid material is inexpensive and advantageous in terms of post-treatment.

After the solvent vapor has been absorbed by the gas-liquid contact method, the water may be post-treated in a conventional manner and disposed of as waste water.

According to the present invention, since the amount of solvent used is small, it is useful for resource saving, and the amount of solvent volatilized is also significantly smaller than that of the conventional method, so it is extremely effective from the point of view of preventing air pollution.

Furthermore, since a specific solvent composition is used in the present invention, the solvent vapor generated during the blow-blow painting or coating film formation process can be very easily recovered by a gas-liquid contact method, and therefore hardly pollutes the atmosphere. do not have.

The present invention will be explained in more detail with reference to Examples below.

Parts and % in the formulation indicate parts by weight and % by weight.

■ Production example of modified polyester resin A In a reaction vessel equipped with a stirrer, a thermometer, and a water separator, 74 parts of phthalic anhydride (0.50 mol), 107.2 parts of trimethylolpropane (0.80 mol), and Cardura E are added. (5h
50 parts (0.2 mol) (manufactured by Ell Chem) were charged and kept at 180°C for 2 hours while heating and stirring, and then raised to 230°C to proceed with condensation.

When the acid value reaches 7.3, it is cooled and 25 parts of ethylene glycol monoethyl ether acetate is added.

When the temperature of the contents reaches 70°C, 10 parts of hexamethylene diisocyanate is added and kept at 80°C for 2 hours.

Next, 34 parts of n-butanol was added to obtain a modified polyester resin solution having a solid content of 80% and a Gardner-Holtz foam viscosity of V/25°C.

The dibasic acid ratio of this polyester resin was 0.50, the hydroxyl equivalent was 125, and the phenyl group content was 16.8%.

Incyanate modification amount is unmodified polyester resin 10
It is 4.45 parts compared to 0 parts.

Production of Modified Polyester Resin BD Modified polyester resin BD was obtained using the raw materials shown in Table 1.2 using the same reaction vessel and reaction method as in the production example of modified polyester resin A.

Production examples A to B are polyester resins that can be used in the present invention, and the others are comparative examples.

Production example of polyester resin E Into a reaction vessel exactly the same as that used for production of polyester resin, 143.6 parts (0.97 moles) of phthalic anhydride, 134.0 parts (1,00 moles) of trimethylolpropane,
105.0 parts (0.50 mol) of coconut oil fatty acid was charged and condensed in the same manner as polyester resin A until the acid value reached 8.1, and then diluted with 90 parts of xylene to obtain an 80% solution.

The viscosity of this solution was z8.

Polyester resin E is an example of an alkyd resin that is also commonly used today.

■ Production example of melamine resin (component (b)) Production of melamine resin A Cymel #300 (Am
Erican Cyanamid Co e% product xakismethoxymethylmelamine purity 95-97%-
(same below) 390 parts (1 mole), 184 parts of ethanol (
4 mol) and 2.8 parts of 60% nitric acid.

The temperature of the reaction system is gradually increased to 60° C., and at the same time the pressure inside the system is reduced to 50 to 60 mmHg.

60 while removing methanol by-produced during the reaction from the system.
React at ℃ for 5 hours.

After the reaction was completed, the solution was neutralized to pH 8.2 with a 30% aqueous sodium hydroxide solution, and the neutralized solution was heated to its boiling point, and unreacted ethanol was removed under reduced pressure.

The concentrate is filtered to remove neutralizing salts.

The obtained product had a solid content of 9967%, a Gardner-Holtz foam viscosity of O/25°C, and its chemical structure was determined by gas chromatography analysis of a phosphoric acid decomposition product to contain 2 to 3 ethoxy groups per melamine nucleus, and free methylol. A mixed methyl and ethyl alkyl etherified methylol melamine with almost no groups was also observed.

Production of melamine resin B 390 parts (1 mol) of Cymel #300 and 51 parts of n-butanol were placed in the same reaction vessel as in the production of melamine resin A.
8 parts (7 moles) and 4.2 parts of 60% nitric acid were prepared in the same manner, solid content 99.2%, Gardner-Holtz foam viscosity L/25.
Contains 4.1 butoxy groups per melamine nucleus at °C,
Methyl, n-, containing almost no free methylol groups
Butyl mixed alkyl etherified methylolmelamine was obtained.

Production of Melamine Resin C 126 parts (1,00 mol) of melamine, n
- 450 parts of 7" tanol formalin (containing 40% formaldehyde) (6 moles as formaldehyde) are heated under reflux for 1.5 hours (during which time the pH is maintained at 7.8 to 7.5 with caustic soda), and then 500 parts of n-butanol and adjusted the pH to 7.5 with phthalic anhydride.
After 3 hours of dehydration through a water separator, a butanol-water-formaldehyde mixture was poured in until the temperature of the contents rose to 117°C.

Furthermore, the solid content was adjusted to 60% with butanol.

The resulting product had a Gardner-Holtz foam viscosity of 5.1 mol of bound formaldehyde per melamine core at 725°C.

Melamine resins A, . . . B can be used as component (b), and melamine resin C can be used as component (C) in the present invention.

Examples 1 to 5, Comparative Examples 1 to 5 (1) Properties of paint and performance of coating film (a) Examples 1 to 3, Comparative Example 1 Rear paints as shown in Table 3 were prototyped and the properties and properties of the paint were evaluated. We investigated the performance of the coating film.

The object to be coated was a 0.8 mm thick mild steel plate coated with an epoxy primer, and the sample was spray coated and then heated and cured at 160° C. for 20 minutes.

Values within 0 in the table indicate the solid content ratio.

(B) Examples 4 to 5, Comparative Examples 2 to 5 In this example, a test was conducted using a white enamel in which 100 PHR of rutile titanium white was dispersed in vehicle solid 100.

The object to be coated, the coating method, and the curing conditions are the same as in the previous example.

Comparative Example 1 uses a modified polyester resin with a low phenyl group content, and is inferior in coating hardness, solvent resistance, etc.

Comparative Example 2 is a case where the dibasic acid ratio is low, and the coating film hardness and solvent resistance are poor, and coating film defects such as repellency and dents are likely to occur.

Comparative Example 3 uses a conventionally used alkyd resin, which has high viscosity and poor thermal stability of the paint.
Difficult to hot spray.

Comparative Examples 4 and 5 are cases with a small amount of catalyst and a case with a large amount of catalyst, respectively.

*○Gel fraction: The clear paint obtained in the implementation flTh and comparative example was applied to a thickness of 2
The coating was applied onto a glass plate using a 4 mil doctor blade and baked at a predetermined temperature (160° C.) for 20 minutes.

Peel off the cured coating film obtained, put about 0.5f into a cylinder of #5A paper, extract with a Soxhlet extractor using acetone as the extraction solvent for 10 hours, and dry at 60℃ in a vacuum dryer to a constant weight. dried until reached.

The weight of the cured coating film before and after extraction was measured, and the weight was included in the following formula to calculate the solvent-insoluble content (%).

Erichsen test: This test was conducted according to IIS Z-2247, and the higher the test result, the better the flexibility.

O Gloss Value: IIS K-54001670 Gasoline Resistance Futashiki Silver Ganrin After immersion at 20°C for 24 hours, the immersed area of the coated plate was pulled up and immediately evaluated based on the degree of swelling and elution.

(2) Recovery of solvent vapor released during painting by gas-liquid contact method The paints obtained in Examples 4 to 5 and Comparative Examples 2 to 3 are spray-painted, and the solvent vapor released at that time is brought into contact with gas and liquid. The recovery effect of this method was investigated using a scrubber method using only water as a liquid material, as follows.

(b) The paints of Examples 4 and 5 and Comparative Examples 2 and 3 are heated (50°C) so that the solvent can easily evaporate, and the exhaust gas from the spray coating is introduced into the air outlet of the absorption tower of the gas-liquid contact device. Spray paint as shown.

The concentration of solvent vapor released during spraying in the air was adjusted to 1100 pp at the air outlet.

(Air flow rate 1707F+”/accumulated). (B) Water supply to the absorption tower 2
A ton of water is put in and circulated, and the flow meter is used to adjust the amount of circulating water to 700 kg/min.

The air at the folding screen opening of the absorption tower is in accordance with JIS-0095 (waste gas sampling method; absorption liquid: water), and the wastewater at the wastewater opening is sampled in each glass bottle (100 m long).

The concentration of the solvent in the sampled air and wastewater was determined using a gas chromatograph.

As a result, as shown in Table 5, the relationship between the concentration at the folding screen opening and time and the concentration of waste water for the air outlet of 1100 ppm is shown in Table 5. In Example 4, the concentration at the folding screen opening reached 10 ppm (90% absorption rate) takes 15 minutes and 20 ppm (80% absorption rate)
It took 33.6 minutes to reach .

The wastewater concentrations at that time were 465 ppm and 936 ppm, respectively.
It was m.

Similarly, the results of Example 5 and Comparative Examples 2.3 are shown in Table 5.

Comparative Example 2.3 showed almost no absorption effect.

Claims (1)

[Scope of Claims] 1(a) Dicarboxylic acid/polyhydric alcohol (molar ratio) (diabasic acid ratio) is from 0.50 to 0.6
5. A modified polyester resin obtained by modifying with 2 to 5 parts by weight of an aliphatic or aromatic diisocyanate compound per 100 parts by weight of a polyester resin having a hydroxyl equivalent of 120 to 250 and containing 10 to 25% by weight of phenyl groups. 80 to 60% by weight and (b) melamine resin 20 whose main component is hexakisalkoxymethylmelamine, in which in the following chemical formula, an average of 2 to 6 R's are alkyl groups having 2 to 4 carbon atoms, and the remainder are methyl groups. 40% by weight, and further (c) if necessary, a melamine resin modified with an alcohol having 1 to 4 carbon atoms in which bound formaldehyde is 5.5 mol or less per 1 mol of melamine is added to the above component (b). (d) 0.05 to 1.00 parts by weight of an aliphatic or aromatic sulfonic acid or an amine salt thereof, and (e) 100 parts by weight of the mixture in a ratio of 1/2% by weight or less. Each component is dissolved at the same time, and the solubility in water at 20°C is 0.5% by weight based on the weight part.
or more, and the vapor pressure at 20°C is 90 mmHg or less, and the sum of the partial pressures of each solvent is 35
mmHg or less, and further contains 80 to 20 parts by weight of a water-insoluble solvent in an amount of 10% by weight or less. A coating method for a thermosetting high solid content coating composition, characterized in that spraying is carried out at a temperature of about 70°C or less. 2(a) dicarboxylic acid, polyhydric alcohol, and if necessary monocarboxylic acid, the dicarboxylic acid/polyhydric alcohol (mole ratio) (dibasic acid ratio) is 0.50 to 0.6
5. A modified polyester resin obtained by modifying with 2 to 5 parts by weight of an aliphatic or aromatic diisocyanate compound per 100 parts by weight of a polyester resin having a hydroxyl equivalent of 120 to 250 and containing 10 to 25% by weight of phenyl groups. gO ~ 60% by weight and (b) Melamine resin 20 whose main component is hexakisalkoxymethylmelamine, in which an average of 2 to 6 of R in the following chemical formula are alkyl groups having 2 to 4 carbon atoms, and the remainder are methyl groups. (e) If necessary, a melamine resin modified with an alcohol having 1 to 4 carbon atoms in which bound formaldehyde is 5.5 mol or less per 1 mol of melamine is added to the above component (b). 1/
(d) 0.05 to 1.00 parts by weight of an aliphatic or aromatic sulfonic acid or an amine salt thereof, and (e) 100 parts by weight of the above mixture per 100 parts by weight of the mixture in a proportion of 2% by weight or less. , the above-mentioned components are simultaneously dissolved, and the solubility in water at 20°C is 0.5% by weight or more, and the vapor pressure at 20°C is 90 mmHg.
It consists of the following water-soluble solvents, and the solvent composition is such that the sum of the partial pressures of each solvent is 35 mmHg or less, and if necessary, the solvent contains 10% by weight or less of a water-insoluble solvent. A thermosetting high solids coating composition formed by mixing parts by weight is sprayed at a coating temperature of about 70°C or less,
A thermosetting high solids paint characterized in that spraying involves recovering the vapor of the solvent that evaporated or volatilized during and/or after painting by a gas-liquid contact method and preventing the vapor from dissipating into the atmosphere. Method of painting the composition.