JPS5824444B2 - Manufacturing method for finely colored hardened resin with excellent solvent resistance and heat resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a finely colored resin having excellent solvent resistance and heat resistance.

Specifically, it is a suspension of a finely colored cured resin obtained by curing a dye-dyed soluble fusible resin derived from benzoguanamine, paratoluenesulfonamide and formaldehyde in the presence of a curing catalyst while maintaining an emulsified state. This invention relates to a method for producing a finely colored cured resin with excellent solvent resistance and heat resistance, which involves separating and drying the cured resin from a material.

Various resin fine powders colored with dyes are used as pigments.

A wide variety of dyes are used, including basic dyes, acidic dyes, and oil-soluble dyes, but fluorescent dyes are often used in order to apply the brightness of dyes to pigments.

Furthermore, resins are broadly classified into thermoplastic resins such as polyvinyl chloride, polyamide, and paratoluenesulfonamide/formaldehyde resins, and thermosetting resins such as amine resins.

The various physical properties of finely colored resin, including its sharpness, are determined by the combination of dye and resin, but the dye dyeing mechanism for resin is complex, and it is difficult to predict the optimal combination. .

It is believed that in order for a dye to develop a clear color in a resin, it is necessary for the dye to be uniformly dissolved in the resin.

Particularly in the case of fluorescent dyes, if the fluorescent dyes are associated in the resin or if the fluorescent dyes are localized in specific parts of the resin, the color development of the fluorescent dyes will be significantly impaired; It is known that light resistance also decreases.

This is a so-called concentration quenching phenomenon that occurs when a large amount of fluorescent dye is added to a medium such as a resin.

Therefore, if a thermoplastic resin with high dye solubility is used, the color development of the dye will be relatively good and fine powder can be easily obtained by crushing, but on the other hand, it will have good solvent resistance and heat resistance. You can't get anything.

On the other hand, if a thermosetting resin is used, it has excellent solvent resistance and heat resistance, but on the other hand, the solubility of the dye after the thermosetting process is low, and the thermosetting resin has a low solubility of the dye after the thermosetting process. Because the solubility decreases, the color development of the dye is often impaired (and it is extremely difficult to pulverize it into a fine powder).

The present inventors added a curing catalyst to an emulsion of benzoguanamine-based soluble and fusible resin colored with a dye, and proceeded with the curing reaction while maintaining the emulsified state to bring the resin into an insoluble and infusible state. We discovered a method for producing finely colored cured resin by separating and drying the cured resin from a suspension of finely colored cured resin, and filed a patent application earlier.

Although the finely colored cured resin obtained by the method described above by the present inventors is made of a thermosetting resin, it has a very high level of color that is not seen in other thermosetting resins, even when a relatively large amount of dye is used. Although it exhibits vivid color development, it has been difficult to increase the amount of fluorescent dye used in the resin, particularly when using a fluorescent dye, due to the occurrence of concentration quenching phenomenon.

In addition, it takes a long time to synthesize the benzoguanamine-based soluble fusible resin to obtain a sufficiently fine (and stable) emulsion, and it is also possible to accelerate the resin formation reaction by using an acid catalyst. However, it has been extremely difficult to control the resin formation reaction rate.

The inventors of the present invention have overcome the above-mentioned difficulties, maintained the excellent characteristics of benzoguanamine-based resins such as solvent resistance and heat resistance, made finely colored cured resins more vividly colored, and further improved the resinization reaction time. As a result of research on methods for shortening, the application of soluble fusible resins derived from benzoguanamine, para-toluenesulfonamide and formaldehyde has provided better sharpness to finely pigmented cured resins, and also soluble soluble resins. This book discovered that it is possible to promote and easily control the resinization reaction of a fusible resin, and further, when using a fluorescent dye, it is possible to increase the amount of fluorescent dye used in the resin, thereby imparting better light resistance. It is a completed invention.

The present invention involves reacting a mixture of 99 to 65 parts by weight of benzoguanamine and 1 to 35 parts by weight of paratoluenesulfonamide with formaldehyde in an aqueous medium at a ratio of 1.2 to 3.5 mol per 1 mol of the mixture. After dyeing the resulting soluble resin with a dye and emulsifying it with a protective colloid, a curing catalyst is added to proceed with the curing reaction while maintaining the emulsified state, bringing the resin to an insoluble and infusible state. This method is characterized by separating and drying the cured resin from a suspension of finely colored cured resin.

The soluble resin in the present invention has been made hydrophobic and is in a state similar to a water-in-oil emulsion.
It is a resin that is soluble in organic solvents such as dioxane and methanol, but substantially insoluble in water.

Conventionally, attempts have been made to obtain finely colored resins using cocondensates of halatoluenesulfonamide/formaldehyde resins and thermosetting amino resins, but these conventionally known finely colored resins have poor solvent resistance and heat resistance. In order to impart this, it is necessary to increase the proportion of the thermosetting amine resin, and as a result, it is extremely difficult to pulverize the resin by pulverization, making it difficult to obtain a sufficiently fine, finely colored resin.

Therefore, in order to facilitate pulverization by pulverization, it is currently necessary to sacrifice solvent resistance and heat resistance.

The present invention overcomes the above problems at once by using an emulsion of a soluble resin derived from benzoguanamine, paratoluenesulfonamide, and formaldehyde, and provides a microstructure with balanced physical properties. It provides a colored cured resin.

That is, the finely colored cured resin obtained by the present invention exhibits more vivid coloring without impairing the excellent characteristics of benzoguanamine resins such as solvent resistance and heat resistance, and particularly when fluorescent dye is used, It becomes possible to increase the amount of fluorescent dye used in the resin without causing the concentration quenching phenomenon, and the light resistance is also significantly improved.

The excellent properties such as solvent resistance and heat resistance developed by the present invention are unique to thermosetting resins such as benzoguanamine formaldehyde resin.

In addition, when a fluorescent dye is used, the excellent clarity of fluorescence and light resistance of the fluorescent pigment obtained by the present invention are due to the extremely stable retention of the fluorescent dye in the paratoluenesulfonamide/formaldehyde resin as a solid solution. Based on the properties obtained, the soluble fusible resin of the present invention maintains the fluorescent dye uniformly in the cured resin without reducing the ability to dissolve the fluorescent dye even after becoming insoluble. It is something that is expressed for the sake of.

The soluble fusible resin in the present invention is prepared according to a conventionally known method, for example, 1 mol of formaldehyde,
2 to 3.5 mol, pH 4 to 10, reaction temperature 50 to 100
It can be easily obtained by reacting at ℃ conditions.

In this case, the resin formation reaction proceeds more quickly than when p-toluenesulfonamide is not used, making it possible to shorten the resin formation reaction time.

In general, acid catalysts are effective in promoting the resinization reaction of benzoguanamine-based resins, but in that case, it is very difficult to control the resinization reaction.
Application of soluble and fusible resins derived from para-toluenesulfonamide and formaldehyde facilitates smooth promotion of the resinization reaction.

In the present invention, the blending ratio of benzoguanamine and paratoluenesulfonamide is 99 to 99%.
A range of 65 parts by weight and 1 to 35 parts by weight of para-toluenesulfonamide is effective, and as the proportion of para-toluenesulfonamide increases, the resin formation reaction time is shortened, especially when a fluorescent dye is used. The sharpness and light resistance of the fluorescent light of the finely colored cured resin will improve.

However, if the amount increases too much beyond this range, physical properties such as solvent resistance and heat resistance will be impaired, so care must be taken.

Furthermore, when the blending ratio of para-toluenesulfonamide is 1 part by weight or less, the effect of co-condensation of benzoguanamine, para-toluenesulfonamide and formaldehyde is extremely small, and soluble and fusible products without the use of para-toluenesulfonamide are produced. The resin becomes substantially the same as the resin.

In particular, a co-condensate of formaldehyde and a mixture consisting of 85 to 7 parts by weight of benzoguanamine and 15 to 30 parts by weight of paratoluenesulfonamide is preferred as it effectively exhibits the effects of the present invention.

In addition, the acetone miscibility calculated by the following formula is 150 to 35
Soluble fusible resins in the 0% range are preferred to obtain fine (and stable) emulsions in subsequent steps.

If the acetone miscibility exceeds 350%, the affinity with water is too strong, and when it is added to an aqueous protective colloid solution under stirring to emulsify it, it becomes plasticized and weakened by the water, causing problems in the stability of the emulsion. If it is less than 150%, the viscosity of the soluble and fusible resin is high, making emulsification difficult and coarse particles likely to occur.

(In the formula, W is the amount of water required to cause the solution to become cloudy by adding water dropwise to a solution of 2 g of soluble resin dissolved in 5 g of acetone while maintaining the temperature at 25 ° C. 2).

) Various methods can be used to dye the soluble resin with a dye and emulsify it with a protective colloid.

For example, a method in which a dye is added to a soluble fusible resin, stirred to dye the resin, and then poured into an aqueous protective colloid solution under stirring to obtain an emulsion; A method of dyeing at the same time as obtaining an emulsion of the resin by adding it to an aqueous solution of a protective colloid under stirring; A method in which a soluble fusible resin is added to obtain an emulsion of the resin and dyeing is carried out at the same time, and a soluble fusible resin is added to an aqueous protective colloid solution under stirring to prepare an emulsion in advance. Next, a method of dyeing by adding a water-soluble dye to the emulsion and stirring sufficiently can be mentioned.

The suspension of finely colored hardened resin in the present invention is obtained by dyeing a soluble fusible resin with a dye according to any of the methods described above and emulsifying it using a protective colloid, and then adding a hardening catalyst to the emulsion and emulsifying it. It is obtained by proceeding with the curing reaction while maintaining the resin state to bring the resin to an insoluble and infusible state.

At this time, if necessary, the specific surface area measured by the BET method with respect to 100 parts by weight (solid content) of the emulsion before hardening is in the range of 50 m'/2 to 400 m''/?
Ultrafine particulate silica 1 to 1 with a particle size of 0.05 microns or less
It can be added in proportions ranging from 5 parts by weight.

Examples of the protective colloid used in the present invention include polyvinyl alcohol, polyvinylpyrrolidone, alkali metal salts of polyacrylic acid, and alkali metal salts of styrene-maleic acid copolymer, among which polyvinyl alcohol is particularly preferred.

The amount of protective colloid used is 1 to 30 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the soluble resin.

The curing catalyst used in the present invention includes those used as curing catalysts for amino resins, such as mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; carboxylic acids such as benzoic acid, phthalic acid, and acetic acid; benzenesulfonic acid, and baratoluene. It can be appropriately selected from the group consisting of sulfonic acids such as sulfonic acid and dotecylbenzenesulfonic acid.

These curing catalysts are added in a proportion ranging from 0.01 to 5 parts by weight per 100 parts by weight (in terms of solid content) of the emulsion of the soluble and fusible resin.

The pH of the emulsion during the curing reaction is preferably in the range of 2.0 to 5.5.

After the curing reaction is completed, the insoluble and infusible cured resin is separated from the aqueous medium and dried to obtain a finely colored cured resin.

The finely colored resin obtained by the method of the present invention has excellent solvent resistance, heat resistance, etc., and especially when a fluorescent dye is used to color the soluble fusible resin, despite the increase in the amount of fluorescent dye, It fully demonstrates the original clarity of fluorescent dyes, and also has excellent light resistance, so it can be effectively used in a very wide range of fields.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 120'i? of benzoguanamine was added to a fourth flask equipped with a stirrer, reflux condenser, and thermometer. (0.64 mol), paratoluenesulfonamide 30f (0.17 mol), 37% concentration formaldehyde aqueous solution 1181 (146 mol) and 10% concentration sodium carbonate aqueous solution 0.47
? were charged and reacted for 2 hours at a temperature of 94 to 95° C. with stirring to obtain a soluble and fusible resin of benzoguanamine, paratoluenesulfonamide and formaldehyde.

"Kuraray Bobal 205" (Holyvinyl alcohol manufactured by Kuraray Co., Ltd., degree of saponification 87-89 mol%, degree of polymerization 5
00) 6.0P water 600'f! The above-mentioned soluble resin was added to the aqueous solution obtained by dissolving the resin and emulsified with vigorous stirring using a homomixer.

60-Damine FB” (basic dye manufactured by BASF) in the emulsion
4.5P was added and stirred at room temperature for 30 minutes for staining.

Next, 40 g of IN-sulfuric acid was added, and the mixture was heated at 40°C, 50°C, and 60°C.
℃, 70℃, 80℃, and 90℃ for 2 hours with stirring to cure the resin in an emulsified state to obtain a suspension of an insoluble and infusible cured resin dyed with a dye. .

The cured resin was separated from the suspension and dried at 100°C.
After heat treatment at .degree. C. for 3 hours, the mixture was lightly crushed in a mortar to obtain a cured resin fine powder that emitted very clear reddish-purple fluorescence.

Example 2 In the same flask as used in Example 1 were added benzoguanamine 105P (0.56 mol), paratoluenesulfonamide 4Fl (0.26 mol), 112 g (1.38 mol) of formaldehyde aqueous solution with a concentration of 37% and concentration 10
An aqueous solution of 0.459% sodium carbonate was added, and the mixture was reacted for 40 minutes at a temperature of 94 to 95°C while stirring.

Then add ``Kayaset Flavin FN'' (oil-soluble dye manufactured by Nippon Kayaku Co., Ltd.) 7.El and keep at 94-95℃ for 30 minutes.
After stirring for a minute, the dye was dissolved in the soluble resin and dyed.

The dyed soluble resin was added to an aqueous solution obtained by dissolving ``Kuraray Boval 205''6.1'' in 600 g of water and emulsified with vigorous stirring using a homomixer.

After cooling the emulsion to 30°C, 40 g of IN-sulfuric acid was added, and the mixture was heated at 40°C, 50°C, 60°C, 70°C, 80°C, and 90°C.
The mixture was heated and stirred at each temperature for 2 hours in order, and cured in an emulsified state to obtain a suspension of an insoluble and infusible cured resin dyed with a dye.

The cured resin was separated from the suspension and dried at 100°C.
After heat treatment at ℃ for 3 hours, the mixture was crushed in a mortar to obtain a cured resin fine powder that emitted a very clear yellow fluorescence.

Example 3 In the same flask as used in Example 1, benzoguanamine 135P (0,72 mol), paratoluenesulfonamide 15S' (0,09 mol), formaldehyde aqueous solution 1241 (1,53 mol) with a concentration of 37% and Concentration 1
0% carbonic acid) I) Prepare 5 oy of rum aqueous solution,
The mixture was reacted for 3 hours and 10 minutes at a temperature of 94 to 95° C. with stirring to obtain a soluble and fusible resin.

°゛Kuraray Bhopal 205'' 6.0?Water 600
? The above-mentioned soluble resin was added to the aqueous solution obtained by dissolving the resin and emulsified with vigorous stirring using a homomixer.

Add "Rhodamine FB" 4.5P to the emulsion and stir at room temperature for 30 minutes, then add IN-sulfuric acid 401 and stir at room temperature for 30 minutes.
℃, 50℃, 60℃, 70℃, 80℃, and 90℃ for 2 hours with stirring to cure the resin in an emulsified state. A cloudy substance was obtained.

The cured resin was separated from the suspension and dried at 100°C.
After heat treatment at .degree. C. for 3 hours, the mixture was lightly crushed in a mortar to obtain a cured resin fine powder that emitted very clear reddish-purple fluorescence.

Example 4 In the same flask as used in Example 1, benzoguanamine 148S' (0,79 mol), para-toluenesulfonamide 2f (0,01 mol), formaldehyde aqueous solution 129P (1,59 mol) with a concentration of 37% and concentration 10
% carbonic acid) IJum aqueous solution 0.52? were charged and reacted for 4 hours and 40 minutes at a temperature of 94 to 95°C while stirring to obtain a soluble fusible resin.

To an aqueous solution obtained by dissolving Kuraray Boval 205''6.01 in 600 g of water, the above-mentioned soluble resin was added and emulsified while stirring vigorously using a homomixer.

Add 4.5P of "Rhodamine FB" to the emulsion, stir at room temperature for 30 minutes, then add 40% IN-sulfuric acid,
℃, 50℃, 60℃, 70℃, 80℃, and 90℃ for 2 hours with stirring to cure the resin in an emulsified state. A cloudy substance was obtained.

The cured resin was separated from the suspension and dried at 100°C.
After heat treatment at ℃ for 3 hours, the mixture was lightly crushed in a mortar to obtain a fine cured resin powder that emitted clear reddish-purple fluorescence.

Comparative Example l In the same flask as used in Example 1, benzoguanamine 150S' (0.8 mol), formaldehyde aqueous solution 130f (1.6 mol) with a concentration of 37% and a concentration of 10%
0.529 of an aqueous solution of sodium carbonate was added, and the reaction was carried out at a temperature of 94 to 95° C. for 5 hours with stirring to obtain a soluble and fusible resin for comparison.

゛'Kurare Bobal 205"6.01 water 600'y'
A soluble and fusible resin for comparison was added to the aqueous solution obtained by dissolving the resin and emulsified with vigorous stirring using a homomixer.

Add ゛°Rhodamine FB'''4゜52 to the emulsion and add 30
Stir for 4 minutes at room temperature, then add 40 g of IN-sulfuric acid,
The resin was cured in an emulsified state by heating and stirring at each temperature of 0°C, 50°C, 60°C, 70°C, 80°C, and 90°C for 2 hours, and the comparative insoluble and infusible resin dyed with dye was prepared. A suspension was obtained.

Comparative resin was separated from the suspension and dried at 100°C.
After heat treatment at .degree. C. for 3 hours, the mixture was lightly crushed in a mortar to obtain comparative fine cured resin powder that emitted clear reddish-purple fluorescence.

However, the comparative fine resin powder obtained in this manner was slightly inferior in the sharpness of the reddish-purple fluorescence compared to that of Example 1.

Comparative Example 2 In the same flask as used in Example 1, benzoguanamine 12Of (0.64 mol) and melamine 30P (0.2
4 mol), formaldehyde aqueous solution 161 with a concentration of 37%
7P (2.0 mol) and 10% sodium carbonate aqueous solution 0-65P were prepared and heated to 94-95℃ while stirring.
The reaction was carried out at a temperature of 3 hours and 30 minutes to obtain a soluble resin for comparison.

A soluble and fusible resin for comparison was added to an aqueous solution obtained by dissolving 6 Kuraray Poval 205''6-01 in 600 g of water and emulsified it while stirring vigorously using a homomixer.

Rhodamine FB"4.52 was added to the emulsion and stirred at room temperature for 30 minutes, then IN-sulfuric acid 402 was added and heated at 40°C.
, 50° C., 60° C., 70° C., 80° C., and 90° C. by heating and stirring for 2 hours at a time to harden the resin in an emulsified state to obtain a suspension of comparative insoluble and infusible resin dyed with a dye. Obtained.

Comparative resin was separated from the suspension and dried at 150°C.
After heat treatment at .degree. C. for 3 hours, the mixture was lightly crushed in a mortar to obtain comparative fine cured resin powder that emitted clear reddish-purple fluorescence.

However, the comparative fine resin powder obtained in this manner had inferior reddish-purple fluorescence in sharpness compared to that of Example 1.

Comparative Example 3 In the same flask as used in Example 1, benzoguanamine 90P (0.48 mol), halatoluenesulfonamide 60F ((135 mol), and formaldehyde aqueous solution with a concentration of 37% 106.21 (1.31 mol) were added. Then, an aqueous sodium carbonate solution having a concentration of 10% (0.42%) was charged, and the mixture was allowed to react at a temperature of 94 to 95° C. for 20 minutes with stirring to obtain a soluble and fusible resin for comparison.

A soluble resin for comparison was added to an aqueous solution obtained by dissolving Kuraray Boval 205''6.02 in 600 g of water and emulsified while stirring vigorously using a homomixer.

Rhodamine FB"4.52 was added to the emulsion and stirred at room temperature for 30 minutes, then IN-sulfuric acid 401 was added and the mixture was heated at 40°C.
, 50°C, 60°C, 70°C, 80°C, and 90°C with heating and stirring for 2 hours each to cure the resin in an emulsified state, and then create a suspension of cured resin dyed with a dye for comparison. I got something.

Comparative resin was separated from the suspension and dried at 100°C.
After heat treatment at 0.degree. C. for 3 hours, the mixture was lightly crushed in a mortar to obtain a comparative fine resin powder that emitted very clear reddish-purple fluorescence.

However, the comparative resin fine powder obtained in this way had inferior heat resistance compared to that of Example 1, and fusion of the resin was observed after heat treatment at 150°C, and it also had inferior solvent resistance, such as acetone, etc. Ketones: Dissolution of the resin was observed in esters such as ethyl acetate.

Example 5 The solvent resistance of the fine resin powders obtained in Examples 1 to 4 and Comparative Examples 1 to 3 was tested by the following method.

The results were as shown in Table 1.

Test method> A liquid obtained by dispersing fine resin powder in methyl ethyl ketone is observed using a microscope (magnification: 400 times).

When a fine resin powder with poor solvent resistance is dispersed in methyl ethyl ketone, its surface is affected by the methyl ethyl ketone and becomes sticky, and a phenomenon in which the fine powder aggregates and becomes coarse is observed.

Example 6 The light resistance of the finely colored cured resins obtained in Examples 1 to 4 and Comparative Examples 1 to 3 was tested by the following method.

The results were as shown in Table 2.

Test method> 1% of finely colored cured resin is mixed into polypropylene (Mitsui Petrochemical Co., Ltd. product "J~600") and a colored plate with a thickness of 3 mm is prepared by injection molding.

The obtained colored blade was placed in a xenon weather meter (“WE-6X-HC” manufactured by Suga Test Instruments Co., Ltd.) for 2 hours.
After exposure for 4 hours, 8 hours, and 8 hours, the degree of discoloration of the colored plate was measured with the naked eye.

Example 7 Acetone miscibility 2 in Examples 1 to 4 and Comparative Example 1
The time required to prepare a 50% soluble fusible resin was as shown in Table 3.

As is clear from Table 3, according to the present invention, the desired soluble and fusible resin can be prepared in a short time.

Claims (1)

[Claims] 1 A mixture consisting of 99 to 65 parts by weight of benzoguanamine and 1 to 35 parts by weight of paratoluenesulfonamide and formaldehyde in a ratio of 1.2 to 3 parts by weight per 1 mole of the mixture.
．． The soluble resin obtained by reacting in an aqueous medium at a ratio of 5 moles is dyed with a dye and emulsified using a protective colloid, and then a curing catalyst is added and the curing reaction is carried out while maintaining the emulsified state. A method for producing a finely colored cured resin having excellent solvent resistance and heat resistance, which comprises advancing the resin to an insoluble and infusible state, and separating and drying the cured resin from a suspension of the resulting finely colored cured resin.