JPH0453818A - Improved hardener master batch for epoxy resin - Google Patents

Abstract

PURPOSE: To obtain a curing agent masterbatch for a one-component epoxy resin curing composition excellent in storage stability and curing properties by dispersing a fine spherical amine compound/epoxy compound adduct in a liquid epoxy resin, adding a polyfunctional isocyanate compound thereto and subjecting the mixture to heat treatment.

CONSTITUTION: Fine spherical adduct particles to be synthesized from an amine compound and an epoxy compound are dispersed in a liquid epoxy resin and then, 5-100 pts.wt., based on 100 pts.wt. adduct, polyfunctional isocyanate is added thereto and the mixture thus obtained is subjected to heat treatment.

COPYRIGHT: (C)1992,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application J This invention relates to a curing agent masterbatch for epoxy resins. More specifically, it not only has excellent storage stability as a curing agent master bunch and is compatible with epoxy resins, but also has excellent storage stability when mixed with epoxy resins.
The present invention relates to a curing agent masterbatch for epoxy resins that provides a low-viscosity one-component curing composition that has a fast curing speed and excellent storage stability.

[Prior art] Cured epoxy resin has adhesive properties, mechanical properties, thermal properties,
Due to its excellent chemical resistance and electrical properties, it is widely used industrially for paints, adhesives, and as insulating materials for electrical and electronic applications. Epoxy resin formulations used for these purposes are broadly divided into one-component systems and two-component systems.

A two-component system consists of an epoxy resin formulation and a curing agent or combination thereof, which are stored separately.

If necessary, the two are measured and mixed by the user for use, but it is often practically difficult to avoid measurement errors and always obtain a homogeneous cured composition. The reaction between the epoxy resin and the curing agent begins upon mixing. The general form of the epoxy resin curing composition is liquid, and in the case of a composition in this form, the viscosity of the yarn gradually increases after mixing, and it undergoes gelation and hardening. The time until it gels and becomes unusable is called pot life. Pot life is determined by the chemical structure and composition of the epoxy resin and hardener. - For boat fishing, systems with a fast curing speed will have a short pot life.

If a curing agent that focuses on curing speed is used, room temperature or low temperature curing compounding becomes possible, but this inevitably shortens the pot life and requires frequent compounding in small amounts, resulting in a significant drop in work efficiency. It's hard to escape.

On the other hand, in one-component systems, the epoxy resin and curing agent are mixed in advance, so all the problems associated with two-component systems are solved. A curing agent used for this purpose is called a latent curing agent. The simplest one-component system is obtained by blending a high temperature curing agent such as dicyandiamide, phenol novolac, adipic dihydrazide, diallylmelamine, diaminomaleonitrile, BF3-amine complex, amine salt, modified imidazole compound, etc. These high-temperature curing agents have a slow curing rate and the reaction at room temperature does not proceed slowly, so they can be stored stably at room temperature or lower for an apparently long period of time, and they can be stored stably at room temperature or lower temperatures for a certain period of time. Enables one-component formulation that cures with If this is a high-temperature hardening agent that does not dissolve in the epoxy resin at room temperature and is dispersed in the form of particles, the storage stability will be significantly improved. This is obviously because the contact area with the epoxy resin becomes extremely small. Such a dispersion type curing agent can also be said to be a type of latent curing agent.

However, with such latent curing agents, it is impossible to prepare a one-component curing composition having sufficient storage stability. A full-fledged one-component cured composition with sufficiently long storage stability is
In its original state, it essentially does not react with epoxy resin,
Requires the formulation of a full-fledged latent curing agent that is activated by stimulation. Aminimide compounds activated by thermal decomposition, ketimine compounds activated by contact with moisture,
Examples include aromatic diazonium salt compounds, diallyliodonium salt compounds, triallylsulfonium salts, or selenium salt compounds that are activated by light irradiation, and curing agents that are microencapsulated with materials that are destroyed by mechanical pressure or heat.

Of these, the one that is most advanced in practical application is a curing agent in which solid particles of an amine compound/epoxy compound adduct are treated with a polyfunctional isocyanate compound to significantly improve its latent curing properties, and is disclosed in JP-A-64 -70523 and Japanese Patent Application Laid-Open No. 1-113480.

For this type of latent curing agent, which is unavoidably expensive, it is advantageous to use an ionic polymerization type curing agent that can be cured even with a small amount of addition without worrying about the equivalent ratio of addition.From a performance standpoint, metal Anionic polymerization type curing agents (tertiary amine adducts) that are free from corrosion are preferred.Amine compounds/
The epoxy compound adduct is first obtained in the form of a lump by reacting an amine compound with an epoxy resin in a solvent and then removing the solvent from the system. Next, it is crushed and further classified to take out curing agent particles of the desired size. Next, the amine compound/epoxy compound adduct particles are dispersed in a liquid epoxy resin, and the polyfunctional polyisocyanate 7-
The desired latent curing agent is produced as a masterbatch by adding and reacting the above compound. JP-A-1-1
In 13480, the added polyfunctional isocyanate compound is adsorbed onto the amine compound/epoxy compound adduct particles dispersed in the epoxy resin, and reacts with the hydroxyl groups and water contained therein to form polyurethane and polyurethane. It is estimated that they coalesce to form a capsule membrane. This heat-melting film prevents direct contact between the adduct particles and the epoxy resin, thereby imparting latent properties. In addition, the polymer composition of the capsule membrane is controlled by the amount of water contained in the adduct particles. It has been shown that it is possible to produce encapsulated adduct particles that survive mixing processes.

[Problems to be Solved by the Invention] The amine compound/epoxy compound adduct particles used in the production of the conventional curing agent masterbatch described above are formed in a crushed form and have a relatively large average Stokes diameter of 3 μm or more. It is something. Due to this particle shape and relatively large particle size, various undesirable problems arise as a curing agent masterbatch, including:

<Crushed particle shape> Contributes more to viscosity increase than spherical particles. Regarding the hardening agent master haunch, there is a limit to the viscosity that can be handled, so the concentration of the hardening agent must be kept relatively low. Therefore, when preparing a cured epoxy resin composition by blending this curing agent master bunch, there is no problem if the epoxy resin to be cured is the same as the epoxy resin as the dispersion medium of the curing agent master batch.
When different types are used, dilution of the epoxy resin to be cured by the dispersion medium epoxy resin becomes a problem. In addition, when compounding, a high tendency to increase viscosity reduces the degree of freedom in compounding design, which is undesirable and results in large particle sizes> In conventional large amine compound/epoxy compound adduct particles, the amount of polyfunctional isocyanate compound added is Although storage stability certainly improves as . It is impossible to change these contradictory trends independently. For this,
Although the amine compound/epoxy compound adduct particle masterbatch treated with a polyfunctional isocyanate compound has various excellent advantages as a curing agent, it has yet to be fully utilized in the l-component curing composition. not present.

[Means for Solving the Problems] The present inventors have overcome the problems of the multifunctional polyisocyanate compound-treated amine compound/epoxy compound adduct particle masterbatch according to conventional techniques, and have developed a one-component epoxy resin curing composition. Through intensive research, we have developed a curing agent that can fully take advantage of the advantages of: By treating 100 parts by weight of adduct particles with 5 to 100 parts by weight of a polyfunctional polyisocyanate compound, a high-concentration latent curing agent masterbatch with excellent curing reactivity is to be produced. In dispersion cure compositions, small curing agent particle size provides two advantages in curing reactivity.

First, curing reactivity improves simply by reducing the curing agent particle size. This is explained in the literature [Journal of Ap
plied Polymer 5science, 32.
5095 (1986)]. Next, small-sized amine compound/epoxy compound adduct particles with a significant interfacial area are coated with a large amount of polyfunctional isocyanate compound bipolymer layer, which is effective in reducing curing reactivity, without increasing the thickness. treatment with polyfunctional isocyanate compounds becomes possible. It is reported in the literature that this polyfunctional isocyanate compound polymer rapidly decomposes into polyfunctional isocyanate compounds at the curing temperature of the epoxy resin curing composition in the presence of a tertiary amine [Coloring Materials Association Journal, ■, 676 (1980)] As revealed in Figure 1, the polyfunctional isocyanate compounds generated here greatly contribute to the curing of the epoxy resin. Due to these two functions, the curing agent masterbatch of the present invention enables a one-component epoxy resin curing composition with excellent curability while having excellent storage stability.

To give specific examples, Tables 1 and 2 summarize the results of comparative examples and examples. Table 1 shows that 40 parts by weight of spherical 2-methylimidazur (2Mz)/bisphenol A diglyrediether (BADGE) adduct particles with a sum of 0.2μ are dispersed in 100 parts by weight of BADGH.
A curing agent masterbatch produced by treating with different amounts of polyfunctional isocyanate compounds, a curing composition in which this curing agent masterbatch is blended with BADGH to be cured so that its concentration is 15% based on the adduct; The properties of the cured products are shown.

Table 2 describes 2Mz/BADGE adduct particles of 0.52μ.

The period of stable storage during which the viscosity of the cured composition remains within a usable range increases rapidly with increasing throughput of polyfunctional isocyanate compound. On the other hand, gel time, which is a measure of fecalability, exhibits completely different behavior depending on the curing temperature. When baking at temperatures below 110°C, the curability decreases rapidly as the amount of polyfunctional isocyanate compound increases; however, when baking at temperatures above 120°C, the curability decreases rapidly as the amount of polyfunctional isocyanate compound increases. At the same time, the curability tends to decrease somewhat when the amount of treatment is small, but it gradually improves beyond that amount. 0
．． A similar trend is observed for 52 μm adduct particles, but for cured compositions from curing agent masterbatches in the low polyfunctional isocyanate compound throughput region, 120°
No decrease in curing speed is observed in baking at temperatures above C. As described above, the acceleration of the curing reaction during baking at 120° C. or higher becomes more pronounced as the amount of polyfunctional isocyanate compound treated increases, but this effect can only be enjoyed with adduct particles of small particle size. As the particle size increases, the capsule membrane layer becomes too thick, presumably making it impossible for the polyfunctional isocyanate compound generated by thermal decomposition to easily contact the epoxy resin. In the present invention, the particle diameter of the spherical particles is suitably in the range of 0.05 to 3 μm, preferably 0.1 to 1.0 μm.

The present invention will be explained in more detail below. First, the spherical fine amine compound/epoxy compound adduct particles are the key to the present invention, and the manufacturing method thereof is detailed in the applicant's application dated May 28, 1990 entitled "Curing agent for spherical epoxy resin." Disclosed. Simply put,
It is produced by reacting an amine compound and an epoxy compound as raw materials in an organic solvent in which they are dissolved but the resulting adduct is not dissolved, in the presence of a suitable dispersion stabilizer. Here, the amine compound and epoxy compound as raw materials for the adduct are selected in consideration of the properties of the adduct as a curing agent. What is important is the chemical structure that promotes anionic polymerization curing, melting point, excellent compatibility in the molten state with the compounded epoxy resin to be cured, fast curing property, and addition effect (high curing reactivity with small addition amount). The melting point here is defined as the melting start temperature in a normal melting point measuring method.

All types of amine compounds can be used for this purpose, but are subject to restrictions depending on the type of epoxy compound to be combined with them. This is because, in the present invention, it is necessary to avoid polymerization and limit the reaction to addition. In contrast to monofunctional engineered poxy compounds, it is possible to combine all kinds of amine compounds;
Only amine compounds having only one active hydrogen that contributes to the reaction with the epoxy group can be combined with the polyfunctional epoxy compound. In either case, there is no problem at all that a tertiary amino group having no active hydrogen may be included. Rather, its presence is preferable in order to increase the concentration of amino groups that contribute to the curing reaction of the adduct, that is, to enhance the effect of addition as a curing agent. As will be described later, the most common epoxy compound is difunctional bisphenol A diglyndyl ether. Taking this compound as an example, examples of amine compounds suitable for combination with it include 2-methyl imidazole and 2.4-
Imidazole compounds such as dimethylimidazole and their carboxylates, N-methylbiperazine and N-
Piperazine compounds represented by hydroxyethylpiperazine, anabasine compounds represented by anabasine, 3.
Pyrazole compounds represented by 5-dimethylpyrazole, purine compounds represented by tetramethylguanidine and purine, pyrazole compounds represented by pyrazole, 1
．． These include triazole compounds typified by 2,4-triazole. All kinds of epoxy compounds can be used as the other raw material. For example, monofunctional compounds include n-butylglycidyl ether, styrene oxide, phenylglycidyl ether, and bifunctional compounds include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, and phthalate diglycidyl ether. Glycidyl esters, trifunctional compounds include triglycidyl isocyanurate, triglycidyl valaminophenol,
Examples of tetrafunctional compounds include tetraglycidyl metaxylene diamine and tetraglycidyl diaminodiphenylmethane, and compounds with higher functional groups include talesol novolac polyglycidyl ether and phenol novolac polyglycidyl ether. However, the same restrictions as described for amine compounds are imposed depending on the type of amine compound to be combined. In other words, for amine compounds that have only one active hydrogen, combinations of all types of epoxy compounds are possible, but
Only monofunctional epoxy compounds can be combined with amine compounds having two or more active hydrogens.

The epoxy compound is selected in consideration of the melting point of the adduct to be produced and its compatibility in the molten state (with the epoxy resin to be cured). Since the overwhelming amount of the epoxy resin to be cured is bisphenol A diglycidyl ether, this compound, which has excellent compatibility with it and is cost-effective, is suitable as an epoxy compound as a raw material for the adduct. can be commonly used. In epoxy compounds, the concentration of epoxy groups is expressed in epoxy equivalents. The lower the epoxy equivalent, the higher the epoxy group concentration, but a high epoxy group concentration is desirable in order to prevent the tertiary amino group concentration of the adduct from decreasing as much as possible.

The melting point of the amine compound/epoxy compound adduct is determined by the chemical structure of the amine compound and the epoxy resin, as well as the mode of addition, the structure of the adduct, and the addition ratio of the epoxy resin to the amine compound. By appropriately selecting them, it becomes possible to synthesize adducts with a low melting point to a high melting point depending on the purpose. The higher the melting point, the easier it is to handle, but the conversely, the higher the curing reaction initiation temperature of the formulation.

Therefore, from the viewpoint of curability, the melting point is not bad, but when considering ease of handling, especially in summer, a melting point of at least 50°C is required.

It is important to select a solvent that dissolves the amine compound and epoxy compound as raw materials, but does not dissolve the addition product and precipitates it as particles. - When you go fishing on a boat, substances dissolve in solvents whose polarity is close to that of A.

The polarity of a solvent is determined by its solubility parameter (unit: (ca
According to this display method, the general melting range is: epoxy compound 28 to II, amine compound: 8 or more, amine compound/epoxy compound addition amount: 11 to II. It becomes 16.

Therefore, in order to carry out the intended precipitation reaction of the present invention, a solvent with a solubility parameter of 8 to 11 is suitable. Examples of solvents used in carrying out the present invention include methyl isobutyl ketone, methyl isopropyl ketone, , methyl ethyl ketone, acetone, acetic acid, n-butyl acetate, isobutyl acetate, ethyl acetate, methyl acetate, tetrahydrofuran, 1,4-dioxane, cellosolve, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, anisole, toluene, p-xylene, Hensen, chloride Examples include methylene, chloroform, trichloroethylene, chlorohenzene, and pyridine. They can be used alone or in combination of two or more.

Even if the solvent has a solubility parameter outside the range of 8 to 11, it is possible to adjust the solubility parameter to within the specified range by combining two or more kinds of solvents and use them.

However, since the exact solubility parameters of a compatible solvent naturally vary somewhat depending on the chemical structures of the amine compound and the epoxy compound, it is important to select them strictly depending on each individual case.

If the selection is not strict, even if the precipitation reaction proceeds smoothly, the resulting adduct may have a high solubility in the solvent, resulting in a low yield.

A dispersion stabilizer stably disperses adduct particles precipitated in a precipitation reaction in a solvent. If it is not present, the produced adduct particles will solidify during the reaction, making it impossible to obtain the desired spherical particles. As a dispersion stabilizer for this purpose, an amphiphilic polymer compound having high affinity for both the produced adduct and the organic solvent is suitable. In terms of chemical structure, graft copolymers, block copolymers, random copolymers, and other polymers all meet the qualification requirements. Examples of graft copolymers:
Methyl methacrylate graft copolymerized with styrene/
Methacrylic acid copolymer, methyl methacrylate/2-hydroxyethyl methacrylate copolymer, poly 2-hydroxy methacrylate]/-, poly 2,3-dihydroxypropyl methacrylate, polyacrylamide-2-methylpropanesulfonic acid, polyvinyl alcohol, Methyl methacrylate/methacrylic acid copolymer obtained by graft copolymerizing polyvinyl acetate, polymethacrylic acid, polyacrylamide, polyethylene oxide and poly4-vinyruethylpyridium bromide, methyl methacrylate,
Glycidyl methacrylate/styrene copolymer and methyl methacrylate/fluoroalkyl acrylate copolymer, polybutadiene and methyl methacrylate/glycidyl methacrylate copolymer grafted with methacrylic acid, polymethyl methacrylate grafted with N-methylol acrylamide, and 2 -Hydroxyethyl methacrylate copolymer, polymethyl methacrylate graft copolymerized with 12-hydroxystearic acid, ethyl acrylate/methacrylic acid polymer, methyl acrylate/methacrylic acid copolymer and styrene/methacrylic acid copolymer, 2-hydroxy Examples include polymethyl methacrylate, which is a graft copolymer of ethyl methacrylate, and polyvinyl chloride, which is a graft copolymer of ethylene oxide. Examples of Fronck copolymers are: polylauryl methacrylate/polymethacrylic acid block copolymers, polystyrene/polymethacrylic acid block copolymers, polyethylene oxide/polystyrene/polyethylene oxide block copolymers and poly-12-hydroxystearic acid. / polyethylene glycol / polyethylene glycol / 2-hydroxystearic acid, etc.

Examples of random copolymers include: vinyl acetate/vinyl alcohol copolymer, vinyl acetate/N-vinylpyrrolidone copolymer, and N-vinylpyrrolidone/methyl methacrylate. Examples of other polymers include cationized amine-modified polyester.The higher the molecular weight of the dispersion stabilizer, the greater the stabilizing effect, but if the molecular weight is increased beyond the limit, on the contrary, the aggregation effect may be reduced. It gradually becomes stronger, which has the opposite effect. Therefore, the molecular weight of the dispersion stabilizer that meets the purpose of the present invention is 1,0.
00 to 200,000, preferably 2.000 to 1
A range of 00,000 is suitable. As mentioned above, there are many types of dispersion stabilizers, but their effects naturally vary depending on the chemical structure of the amine compound/epoxy compound. In practice, trial-and-error selection is required.

When the selected amine compound and epoxy compound are dissolved in the selected solvent, the selected dispersion stabilizer is further dissolved, and the mixture is heated with stirring, the initially transparent solution becomes opaque as adducts form. become.

As the reaction progresses, the opacity of the thread gradually increases, and the thread takes on a cloudy white appearance characteristic of dispersions. The reaction stops when cooled at a suitable point. Only the particles are filtered from the obtained amine compound/epoxy compound adduct particle dispersion,
By washing off unreacted raw materials adhering to the particles with fresh solvent and drying them, the desired spherical curing agent particles can be obtained. The size of the adduct particles is determined by the type of raw materials, reaction conditions, and type and amount of dispersion stabilizer added. Of these factors, the type of dispersion stabilizer is decisive.

The next biggest influence is the reaction conditions; the lower the raw material concentration, stable dispersion concentration, reaction temperature, and reaction rate, and the faster the stirring speed, the smaller the particles produced when fishing on a boat. The particles used for the purpose of the present invention have a diameter of 0.05 to 3 μm, preferably 0.1 to 1.0 μm.
A range of μm is suitable. Below this range υ, the viscosity of the curing agent master haunch becomes too high in the polyisocyanate treatment, and the dispersion concentration of the adduct particles must be set at a fairly low level. In this case, the concentration of the adduct particles becomes too low, and it loses its practical significance as a curing agent masterbatch. Furthermore, if the particle size increases beyond the specified range, no effect of accelerating the curing reaction will be observed even if treated with a large amount of polyfunctional polyisocyanate compound. Fine particles within the range specified herein are produced by setting the factors governing the precipitation reaction described above to appropriate levels.

What is fundamentally important for a liquid epoxy resin used as a dispersion medium for amine compound/epoxy compound adduct particles in the production of a hardening agent masterbatch is the hydroxyl group it contains and its viscosity. The hydroxyl groups react with the polyisocyanate, increasing the viscosity of the system and, in extreme cases, leading to gelation.

Therefore, liquid epoxy resins used for this purpose are required to contain no hydroxyl groups at all, or to contain extremely low levels of hydroxyl groups.

Further, it is desirable that the viscosity be as low as possible. The lower the viscosity of the dispersion medium, the higher the concentration of the appendage particles can be dispersed. In addition to this basic requirement, the intended use of the compounded epoxy resin and cured formulation should also be considered. This consideration is natural since the epoxy resin as a dispersion medium is also incorporated into the cured structure. For formulations with high heat resistance, a dispersion medium epoxy resin that meets this purpose should be selected, and for formulations with low metal corrosion resistance, a dispersion medium epoxy resin with a low content of decomposable chlorine should be selected.

The curing agent masterbatch is produced by treating appendage particles dispersed in a liquid epoxy resin with a polyfunctional isocyanate compound. Polyfunctional isocyanate compounds used for this purpose include toluene diisocyanate, mononuclear and polynuclear forms of methylene diphenyl diisocyanate, hydrogenated methylene diphenyl diisocyanate, 15-naphthalene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, Hydrogenated xylylene diisocyanate 2
-t, tetramethylxylene diisocyanate, ], 3
．． These include 6-hexamethylene triisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, tris (isocyanate phenyl) thiophosphate, and polyfunctional isocyanate compounds produced by addition reactions between these and other active hydrogen-containing compounds. One type or a combination of two or more types selected from these can be used. The amount added to the adduct particles is in the range of 5 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the adduct. If it is below this range, sufficient storage stability cannot be obtained, and if it exceeds this range, the viscosity during processing reaches a level that makes it difficult to manufacture.

Depending on the purpose of use, it is often desirable to condition the humidity of appendage particles before use. Humidity conditioning is easily accomplished by exposing the appendage particles to high humidity. The appendage particles are then uniformly dispersed in a liquid epoxy resin as a dispersion medium. Since fine particles often form secondary particles, mechanical dispersion treatment is required to disperse them as primary particles. A specific example is kneading using a three-roll mill. Finally, the adduct particle-dispersed epoxy resin is heated and stirred, and when it reaches a predetermined temperature,
Polyfunctional isocyanate at a rate that does not cause excessive temperature rise 1.
-) A hardener master bunch is produced by adding a compound and reacting with the appendage particles. After the addition of the polyfunctional isocyanate compound is complete, it is desirable to continue heating and stirring to reduce its concentration as much as possible, but in practical terms, complete disappearance is not always necessary. As is clear from the comparison of transmission electron micrographs in Figures 1 and 2, as a result of this multifunctional isocyanate treatment, the interface of the appendage particles was
-113480, the formation of a capsule membrane is observed. The encapsulated particles photographed here have a particle size of 2
．． 5 μm 2-methylimidazur/BADGE adduct particles were treated with 20% polymethylene diphenyl diisocyanate relative to the adduct. The sample to be photographed was prepared by blending appendage particles and encapsulated adduct particle masterbatch into a BADGE/polyamide polyamine curing composition, heating and curing it at 50°C for 48 hours, slicing it into flakes with a microtome, and then applying osmic acid. It is created by dyeing it. The present invention will be explained in more detail with reference to Examples below.

Comparative Example 1 A three-bottomed round-bottomed flask with an internal capacity of 5,000 m1 was equipped with a thermometer, a reflux condenser, and a glass half-moon stirrer.
3,400 g of methyl isobutyl ketone ([BK) was charged, and 115 g of 2-methylimidazole (2M
z) (1.3 g equivalent) was added and the temperature was raised to 50 °C to completely dissolve the 0. Then methyl methacrylate was grafted as a dispersion stabilizer.Methyl methacrylate/
25% methyl ethyl ketone/butyl acetate solution of methacrylic acid copolymer dispersion stabilizer (manufactured by Toagosei Co., Ltd., GC-
10) Add 146 g of bisphenol A diglycidyl ether (BADGE) with an epoxy equivalent weight of 186.
(Manufactured by Yuka Shell Co., Ltd., Epicoat 828) 5
500 g (1.34 equivalents) of 0% old BK solution was added.

Adduct raw material concentration: 8°8%, total raw material concentration: 9.7%, addition amount of dispersion stabilizer to appendage raw material 710.0%. The contents were reacted at 50° C. for 24 hours while stirring at a speed of 40 rpm. The initially transparent reaction system gradually became bluish and translucent, but at the end of the reaction it turned milky and opaque.

After reaction for a predetermined period of time, the mixture was cooled to room temperature and left to stand day and night to precipitate the generated particles. The supernatant was decanted and the particles were filtered off and washed thoroughly with MIBK. Further, vacuum drying was carried out at 40"C for 24 hours to obtain 81 g of white colored sleeve particles. The particle size was measured using a laser particle size analyzer manufactured by Ohita Denshi Co., Ltd., LPA.
Measured at 3000/3100.

The average particle diameter was 0.21 μm. According to observation using an electron microscope, the shape of the 2Mz/Epicote 828 adduct particles produced by this precipitation reaction method was spherical. Furthermore, analysis using an infrared spectrophotometer revealed that a portion of the dispersion stabilizer used in the production was fixed on the adduct particles.

The spherical additive particles thus produced have an epoxy equivalent of 17
BADGE containing almost no hydroxyl group (DER332 manufactured by Dow Chemical Company) 100 MI! ! 4 for part
0 parts by weight (40 phr) and completely dispersed through a three-roll mill to form a curing agent masterbatch. This curing agent master bunch was then mixed with an epoxy equivalent of 18
6 BADGE (manufactured by Yuka Shell Co., Ltd., Epicoat 828) so that the concentration of adduct particles was 15% to prepare a cured composition. Furthermore, this cured composition
A cured product was prepared by heat curing at 150°C for 1 hour and then 3 hours at 150°C, and its glass transition temperature (Tg), tensile properties, and water absorption were measured. The measurement method is as follows *Tg: Measurement using a differential thermal analyzer, tensile properties: J
Measurement based on IS K7113, water absorption rate: Diameter 39 steel ■
After immersing a 4s-thick sample in water at 100°C for 6 hours, the weight increase rate was measured. Properties of the curing agent masterbatch, cured composition, and cured product are shown in Table 1 in comparison with Examples 1 to 6.

Comparative Example 2 In the round-bottomed three-bottle flask of the apparatus described in Comparative Example 1, 3, 2
40g of MIBK was charged, 115g of 2Mz was added thereto, and the temperature was raised to 50"C to completely dissolve. Then 219g of Gclo was added, followed by 500g of 50% MIBK solution of Epicoat 828. Adduct raw material Concentration = 9.0%, total raw material concentration: 10.3%, amount of dispersion stabilizer added to appendage raw material: 15.0%.Contents: 4
The reaction was carried out at 50°C for 24 hours while stirring at a speed of 0 rpm, and the average particle size was 0.5 in the same manner as in Comparative Example 1.
107 g of spherical additional grains with a sum of 2 μm were obtained. Next, in the same manner as in Comparative Example 1, a curing agent masterbatch, a cured composition, and a cured product were prepared, and their properties were measured. The results are shown in Table 2 in comparison with Examples 7-9.

Example 1 120 g of the 2-Mz/Epicote 828 adduct particles produced in Comparative Example 1 were left at a temperature of 48 hours to allow the adduct to absorb 5.2% of water. The humidity-adjusted particles were added to DER332 of 3008, briefly phased, and then passed through a three-roll mill to completely disperse. The viscosity of the dispersion at 30°C was 29.100 cps. 350 g of the dispersion was transferred to a reactor equipped with a heatable stirrer and heated to 60° C. with stirring. While maintaining this temperature, 10 g of polyMDI (MR-100 manufactured by Nippon Polyurethane Industries Co., Ltd.) was added over about 1 hour, heated for 2 hours while maintaining the same temperature, and then cooled to prepare a curing agent masterbatch. did.

According to measurements using a Shimadzu FTIR analyzer,
1.8% poly? IDI was left unresponsive.

The viscosity of this curing agent masterbatch at 30°C is 5
It was 9,500 cps. In the same manner as in Comparative Example 1, this masterbatch was blended with Epikote 828 at a concentration of 15% on an adduct basis to obtain a cured composition, and a part of it was used as a sample for measuring the cured physical properties described in Comparative Example 1. It was created. Properties of the curing agent masterbatch, cured composition, and cured product are shown in Table 1 in comparison with Comparative Examples and other Examples.

Example 2 350 g of a 2Mz/Epicote 828 adduct particle dispersion prepared in exactly the same manner as in Example 1 was transferred to a reactor equipped with a heatable stirring device, and heated to 60° C. while stirring. Then, while maintaining this temperature, it was heated for about 1 hour.
0 g of polyMDI was added, heated for 2 hours while maintaining the same temperature, and then cooled to obtain a curing agent masterbatch. This contained 2.3% of unreacted IJMDI. The viscosity of this curing agent masterbatch at 30°C was 112.0OOcps. Next, a cured composition was prepared in the same manner as in Example 1, and a cured body sample was prepared by the method described in Comparative Example 1. Properties of the curing agent masterbatch, cured composition, and cured product are shown in Table 1 in comparison with Comparative Examples and other Examples.

Example 3 350 g of a 2Mz/Epicote 828 adduct particle dispersion prepared in exactly the same manner as in Example 1 was transferred to a reactor equipped with a heatable stirrer and heated to 60° C. while stirring. Then, while maintaining this temperature, for about 1 hour 3
0 g of polyMDI was added, heated for 3 hours while maintaining the same temperature, and then cooled to obtain a curing agent masterbatch. This contained 1.7% unreacted polyMDI.

The viscosity of this curing agent masterbatch at 30°C is 1
It was 94,000 cps. Next, a cured composition was prepared in the same manner as in Example 1, and a cured body sample was prepared by the method described in Comparative Example 1. Properties of the curing agent masterbatch, cured composition, and cured product are shown in Table 1 in comparison with Comparative Examples and other Examples.

Example 4 350 g of a 2Mz/Epicote 828 adduct particle dispersion prepared in exactly the same manner as in Example 1 was transferred to a reactor equipped with a heatable stirrer and heated to 60"C with stirring. This temperature was then maintained. 4 for about an hour while
0 g of polyMDI was added, heated for 3 hours while maintaining the same temperature, and then cooled to obtain a curing agent masterbatch. This contained 2.6% unreacted polyMDI.

The viscosity of this curing agent masterbatch at 30°C is 3
It was 05.000 cps. Next, a cured composition was prepared in the same manner as in Example 1, and a cured body sample was prepared by the method described in Comparative Example 1. Properties of the curing agent masterbatch, cured composition, and cured product are shown in Table 1 in comparison with Comparative Examples and other Examples.

Example 5 350 g of a 2Mz/Epicote 828 adduct particle dispersion prepared in exactly the same manner as in Example 1 was transferred to a reactor equipped with a heatable stirrer and heated to 60"C with stirring. This temperature was then maintained. 5 for about 2 hours while
0 g of polyHD+ was added, heated for 4 hours while maintaining the same temperature, and then cooled to obtain a curing agent masterbatch. This contained 2.8% unreacted polyMDI.

The viscosity of this curing agent masterbatch 7 at 30°C was 450.0OOcps. Next, a cured composition was prepared in the same manner as in Example 1, and a cured body sample was prepared by the method described in Comparative Example 1. Properties of the curing agent masterbatch, cured composition, and cured product are shown in Table 1 in comparison with Comparative Examples and other Examples.

Example 6 1350 g of a 9-particle dispersion of 2Mz/Epicote 828 adduct particles prepared in exactly the same manner as in Example 1 was transferred to a reactor equipped with a heatable stirring device, and heated to 60° C. with stirring. Then, while maintaining this temperature, 100 g of polyMDI was added over a period of approximately 2 hours;
The mixture was heated for a period of time and then cooled to form a curing agent master bunch. This contained 2.9% unreacted polyMDI. Although the same applies to the other examples, it is surprising that in this example in particular, the polyMDI of the same weight as the cured particles was almost completely consumed. Poly? I
Considering that Dl reacts only with the hydroxyl group of the adduct, it is impossible to consume Ill in such a large amount of poly. The addition of water in the particles and consumption due to reaction with the carboxyl groups of the dispersion stabilizer fixed to the particles adds up to an acceptable level of consumption. The viscosity of this curing agent masterbatch at 30°C was 1.400.000 cps. Next, a cured composition was prepared in the same manner as in Example, and a cured body sample was prepared by the method described in Comparative Example 1. Properties of the curing agent masterbatch, cured composition, and cured product are shown in Table 1 in comparison with Comparative Examples and other Examples.

In Table 1, the properties of the hardening agent master haunch, the hardening composition, and the hardened product are poly? It changes with the amount of IDI added. First, regarding the properties of the curing agent masterbatch, polyMD
As the amount of I added increases, the viscosity increases by 1, and its storage stability rapidly increases. In terms of storage stability, PolyMil+
It is desirable to add a large amount of phr, but from the viewpoint of manufacturing, the limit is 100 phr, and if the amount added is higher than this, manufacturing becomes extremely difficult. There are various possible causes for the increase in viscosity due to an increase in the amount of polyMDI added, but the most likely cause is an increase in the dispersion f concentration.

This is due to the polymerization of polyMDI due to the water contained in the dispersion medium, and the other part is due to the increase in the molecular weight of the epoxy resin due to the reaction with a trace amount of hydroxyl groups contained in the dispersion medium epoxy resin, and the polymerization of the epoxy resin by an adduct. This is probably due to the addition of curing that increases viscosity.

The storage stability of the cured composition, like that of the curing agent masterbatch, also improves rapidly with increasing polyMDI loading. However, the behavior of gelation time, which is a measure of curing speed, varies dramatically depending on the curing temperature.

When curing at 120°C or higher, there is a slight tendency for the gelation time to increase up to around 10% PolyM, but as the amount added exceeds this, the gelation time increases as the amount added increases. It gradually decreases over time.

This decreasing tendency becomes more pronounced as the heating temperature increases.

On the other hand, in the curing reaction below 110''C, the gelation time becomes longer as the storage stability improves, that is, the curing reactivity decreases.

The properties of the cured product also change as the amount of polyMDI added increases. First, Tg is a measure of heat resistance, and as the amount of polyMDI added increases, this temperature decreases, albeit slightly. The tensile strength also decreases as the amount of polyMDI added increases, but the elongation increases on the contrary, indicating a tendency for the cured product to gradually become stronger. There is no noticeable change in water absorption, which is a measure of water resistance, as the amount of polyMDI added increases.

Example 7 Comparative example 2 as 2Mz/Ebiko) 82B41 additive particles
An adduct particle dispersion was prepared in exactly the same manner as in Example 1 except that adduct particle dispersion #30°
Its viscosity at C was 17.700 cps. 350 g of it was transferred to a reactor equipped with a heatable stirrer and heated to 60"C with stirring. Then, while maintaining this temperature, 10 g of polyester 1 was added over a period of about 1 hour,
The mixture was heated for 2 hours while maintaining the same temperature, and then cooled to obtain a hardening agent masterbatch.

This contained 2.3% unreacted polyMDI.

The viscosity of this curing agent master bunch at 30°C is 3
It was 7,000 cps. Next, a cured composition was prepared in the same manner as in Example 1, and a cured body sample was prepared by the method described in Comparative Example 1. Table 2 shows various properties of the curing agent masterbatch, cured composition, and cured product in comparison with Comparative Example 2 and other Examples.

Example 8 350 g of an adduct particle dispersion prepared in exactly the same manner as in Example 1 was transferred to a reactor equipped with a heatable stirring device, and heated to 60° C. while stirring. Then, while maintaining this temperature, 20 g of polyMDI was added over about 1 hour, heated for 2 hours while maintaining the same temperature, then cooled and combined with the curing agent masterbatch.

This contains 2.8% unreacted poly? It included IDI.

The viscosity of this hardener master punch at 30"C is 7
It was 2,000 cps. Next, a cured composition was prepared in the same manner as in Example 1, and a cured body sample was prepared by the method described in Comparative Example 1. Table 2 shows various properties of the curing agent masterbatch, cured composition, and cured product in comparison with Comparative Example 2 and other Examples.

Example 9 350 g of an adduct particle dispersion prepared in exactly the same manner as in Example 1 was transferred to a reactor equipped with a stirring device capable of heating air, and heated to 60° C. with stirring. Next, 30 g of polyMDI was added over about 1 hour while maintaining this temperature, heated for 3 hours while maintaining the same temperature, and then cooled to form a curing agent master bunch.

This contained 1.9% unreacted polyMDI.

The viscosity of this curing agent masterbatch at 30°C is 1
32,0OOcps. Next, a cured composition was prepared in the same manner as in Example 1, and a cured body sample was prepared by the method described in Comparative Example 1. Table 2 shows various properties of the curing agent masterbatch, cured composition, and cured product in comparison with Comparative Example 2 and other Examples.

In comparing Tables 1 and 2, the effect of adduct particle size becomes apparent. Although there is no fundamental difference in the effect of polyMDI treatment even if the particles become larger, there are some differences in details. The viscosity will be lower and the latent effect will be greater even when treated with the same amount of polyMDI. On the other hand, there are no major differences in the physical properties of the feces.

Example 10 2.750 g of MIB+ was added to the reactor described in Comparative Example 1.
To this was added 195 g of N-methylpiperazine (
NMPz) (1,94 eq.) was added and the temperature was increased to 60° C. to completely melt. Next, as a dispersion stabilizer, a 30% MIBKi solution of methyl methacrylate/methacrylic acid copolymer obtained by graft copolymerizing methyl methacrylate was used.
After adding 425g of Toagosei Co., Ltd. GC-10M), 50% old BK of Epicote 828? 700g liquid
(1,88 eq.) was added. This was reacted at 60° C. for 14 hours with stirring at 40 rpm, and 174 g of spherical adducts with a particle size of 0.55 μm were obtained using the procedure described in Comparative Example 1.

The adduct particles thus obtained were conditioned to contain 5.4% water, and then subjected to DER under exactly the same conditions as in Example 1.
332 were distributed. The viscosity of the dispersion at 30°C is 1
It was 6.800 cps. 350 g thereof was transferred to a reactor equipped with a heatable stirrer and heated to 60''C with stirring.

Then, while maintaining this temperature, 15 g
of polyMDI was added thereto, heated for 2 hours while maintaining the same temperature, and then cooled to obtain a curing agent masterbatch. This contained 2.7% unreacted polyMDI. The viscosity of this curing agent master bunch at 30°C is 43.
000 cps. Next, a cured composition was prepared in the same manner as in Example 1, and a cured body sample was prepared by the method described in Comparative Example 1. Its properties were as follows.

[Curing agent masterbatch] Viscosity at 30°C: 43,0OOcps, 50
Stable storage period at °C: 22 days [cured composition] Viscosity at 30 °C: 12,100 cps, 50°
Stable storage period at C: 35 days, gel time at 120°C and 288 seconds.

[Properties of cured product] Tg: 138°C1 Tensile strength: 5B6kg/cj
, elongation = 10%, water absorption rate after 6 hours immersion in boiling water: 1.1
%.

100 "C ]10'C 12O ℃ 140 °C Table 1 9.100 6 hours immersion in water) 0.7 0.9 0.9 0.8 1.0 1.1 Table 2 (μm) 0.52 0. 52 30 °C Gelling time (seconds 100 °C 110 °C 12O °C 140 °C 30C immersion for 6 hours) 0.52 (Effect of the invention) Fine spherical amine compound/evoquine compound adduct produced by precipitation reaction The particles are dispersed in an epoxy resin containing almost no hydroxyl groups, with a concentration of 10 to 100
% of a polyfunctional isocyanate compound, a curing agent masterbatch with relatively low viscosity can be produced. This curing agent masterbatch has excellent storage stability and facilitates the formulation of curing compositions. 120° again
It is possible to produce a one-component epoxy resin curing composition with excellent storage stability that accelerates curing in a curing reaction of C or higher. The curing agent masterbatch of the present invention is not only capable of anionic polymerization type curing, but also can be used in combination with other high-temperature curing polyaddition type curing agents, such as dianediamide and acid anhydride, at their curing temperature. It acts effectively as a potential accelerator that effectively reduces

Taking advantage of this property, the fine spherical curing agent particles of the present invention enable the use of one-component epoxy/resin curing compositions in a wide range of fields. Examples include the structural adhesive field; vehicle assembly adhesives, optical machinery assembly adhesives, electronic and electrical equipment assembly adhesives, etc., the paint field, powder coatings, baking paints, etc., the electronic field, Niblint wiring boards, etc. Glass cloth impregnation materials, IC chip encapsulants, conductive paints, solder resists, bonding adhesives, printed circuit board adhesives, conductive adhesives, etc.
Electrical field = electrical insulation materials, coil impregnation materials, hunter case adhesives, tape head adhesives, etc.

[Brief explanation of the drawing]

Figure 1 is an electron micrograph showing the structure of non-encapsulated 2-methylimidazole/bisphenol dicrididyl ether adduct particles, and Figure 2 is a cross-sectional view of the encapsulated 2-methylimidazole/bisphenol dicrididyl ether adduct particles. Transparent i showing the structure! 5 is an electron micrograph. Here, the originally spherical particles have an elliptical shape due to deformation during cutting with a microtome. Funeral map A (4 people included)

Claims (1)

[Claims] 1. After dispersing fine spherical adduct particles synthesized from an amine compound and an epoxy compound in a liquid epoxy resin,
A curing agent masterbatch for epoxy resin obtained by treating 100 parts by weight of the adduct with 5 to 100 parts by weight of a polyfunctional isocyanate compound. 2. The fine spherical amine compound/epoxy compound adduct according to claim 1 is dispersed in a liquid epoxy resin to form an adduct 10.
2. The method for producing a curing agent masterbatch for epoxy resin according to claim 1, wherein 5 to 100 parts by weight of a polyfunctional isocyanate compound is added to 0 parts by weight and heat-treated.