JPH02135214A - Latent curing agent for epoxy resin - Google Patents

Abstract

PURPOSE:To obtain the curing agent which has excellent storage stability at room temperature, and gives an easy-to-handle composition of a lowered curing temperature, when being added to an epoxy resin by using a high polymer containing specific five-kinds of recurring units in a specific proportion. CONSTITUTION:Preferably, a monomer giving the recurring unit of formula I (R1, R2 are H, alkyl) and another monomer giving the recurring unit of formula IV (R9, R10 are H, alkyl) are copolymerized, and the resultant copolymer is allowed to react with an amine compound giving the recurring unit of formula II (R3, R4 are H, alkyl; R5 is alkylene; Y is organic group containing secondary and/or tertiary nitrogen), another amine compound giving the recurring unit of formula III (R6, R7, R8 are H, alkyl; alpha>=0, beta>=1 and alpha+beta=5) and the third amine compound giving the recurring unit of formula V (R11, R12 are H, alkyl) to give the objective curing agent which is composed of 50 to 90 mole% of the recurring units of formula I, 0.1 to 50mole% of the recurring units of formula II, 1 to 50 mole% of the recurring units of formula III, 0 to 50mole% of the recurring units of formula IV and 0 to 50mole% of the recurring units of formula V.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a latent curing agent for epoxy resins, and an epoxy resin composition comprising the latent curing agent and an epoxy resin. More specifically, it has excellent storage stability at room temperature when mixed with epoxy resin.

The present invention also relates to a latent curing agent that rapidly cures when heated to provide a cured product with excellent heat resistance and toughness, and a composition comprising the latent curing agent. Furthermore, the present invention relates to an industrially advantageous production method for the curing agent [Conventional technique WI] Epoxy resin has excellent curing properties, and the obtained cured product has excellent adhesive properties, 9 mechanical properties, and chemical resistance. Due to its excellent electrical properties and other properties, it is used in a wide range of industrial fields.

However, when using epoxy resin, it is necessary to combine the two components of epoxy resin and curing agent, but since the combination starts to harden within a short time at room temperature, its use In this case, it is necessary to frequently perform a complicated mixing operation, or it is necessary to store the mixture at a low temperature, which is troublesome in practical use.

Recognizing that this shortcoming greatly limits the uses of epoxy resin, we have set the goal of solving this shortcoming by creating a material that can be mixed with epoxy resin and has excellent storage stability at room temperature, and that can be heated. Attempts have been made to develop curing agents that cure quickly.
Such hardening agents.

It is known as a latent curing agent, and some are already in practical use.

Typical latent curing agents include, for example, dianediamide, organic acid hydrazide, and Lewis acid-amine complex (Kakiuchi Hirone, "New Epoxy Resin", Shokodo (1985)). However, although dianediamide and organic acid hydrazide have excellent storage stability, they have the disadvantage of a high practical curing temperature.

Lewis acid-amine complexes have the disadvantage of high hygroscopicity (poor storage stability).Additionally, these curing agents are low-molecular substances and have relatively high toxicity. As a hardening agent, adducts formed by reacting a compound having a tertiary amino group with an evoquino compound are also known.
No. 61-148228, No. 61-171722
No., U.S. Patent No. 3.756.984, 4. 06
6, No. 625, 4. 268. Although the technology is disclosed in No. 656 and the like, since cured products cured using these curing agents generally have poor heat resistance, they were often used in combination with other curing agents. Furthermore, these compounds are compounds in which a tertiary amino group that functions as an anionic polymerization type curing catalyst for Epoquinolet Mi is added to the end of a linear epoxy resin, but the catalytic ability or curing speed of the latent curing agent is If the amount of curing agent added is constant, it will depend on the molecular weight of the curing agent. Therefore 1
For example, when the curing agent improves or modifies the properties of the cured product, the curing rate and the physical properties of the cured product simultaneously depend on the amount of the curing agent added, which may cause problems.

Acid anhydrides or polyphenol compounds are known to act as curing agents for epoxy resins in the presence or absence of Lewis bases (see "New Ebokino 1 Uji", supra).
? ! 1. For example, a copolymer of styrene and maleic anhydride has a maleic anhydride residue that has the ability to harden an epoxy resin as described above, and the copolymer itself has a high heat resistance. It is known that a cured product made of the copolymer and an epoxy resin has a glass transition temperature and has excellent heat resistance (for example, Japanese Patent Application Laid-Open No. 1983-1999)
No. 64259), and an example is known in which a copolymer of styrene and N-(4-hydroxyphenyl)maleimide is used as a curing agent for epoxy resin (US Pat. No. 4).
．． 623.578), but these copolymers have a slow curing rate in the absence of Lewis bases (practical hardening charcoal does not function as a curing agent, and In the presence of epoxy resins, it has poor storage stability and does not show a residence (1゜[Problem to be Solved by the Invention 3] As mentioned above, there are several known latent curing agents for epoxy resins; All of these had poor functionality as a curing agent, or did not improve the physical properties of the cured product.

The inventor's intention is to provide a curing agent for Evokin Ws resin that has a property and improves the physical properties, particularly heat resistance, of the cured product, and a method for producing the curing agent. Furthermore, there is another intention of the inventor.

The second aspect is to provide an epoxy resin composition containing the curing agent.

General formula [1] General formula [I [] [Means for solving the problem] First, the present invention has a general formula [!] in one molecule. ] 50-90 mol% of the repeating unit represented by the general formula [11], 1-50 mol% of the repeating unit represented by the general formula [1], 1-50 mol% of the repeating unit represented by the general formula [I[1] 50 mol%.

0 to 50 moles of repeating units represented by the general formula [rV] 6r
and a latent curing agent for epoxy resins comprising a polymeric substance having 0 to 50 mol% of repeating units represented by the general formula [V].

General formula [■ General formula [IV] (R8) α (OH) β - Formula [v] General formula [■ General formula [■] (Just LRl, R2, R3, R4, R6,, R7゜R8
, R9, RIO, R11, R12 and R13 are hydrogen atoms, alkyl groups, cycloalkyl groups or aryl groups, and R5 is an alkylene group.

It is an alkylene group bonded to a cycloalkylene group, a phenylene group, or -R14 (wherein LRl4 represents a 10-, cycloalkylene N, aloyher, and enylene group), and Y represents an organic group containing secondary and/or tertiary nitrogen. , α is an integer greater than or equal to θ, β is an integer greater than or equal to 1, and α+β
= 5) Specific examples of organic groups represented by Y include general formula [% formula %] general formula [■] general formula [IX] d (However, R15 and R16 are hydrogen atoms, alkyl groups,
Fuchloroalkyl group. It represents an aryl group or an alkylene group, but both R15 and R16 must not be hydrogen atoms, H represents a hydrogen atom, A represents an alkyl group, cycloalkyl group, or aryl group, and X represents an oxygen atom or - N- (where RI7 is an alkyl group, cycloalkyl group or aryl group), a, b,
c, d.

C and f are integers of 0 or 1 or more, and a+b
=4. c+d=3. eXf≠0. ) In the latent curing agent molecule, - formula [! ] or the repeating unit of the general formula [V] is a unit that is not directly related to the warming reaction of the epoxy resin, and the repeating unit of the general formula [m] or the general formula [
The repeating unit IV] is a unit containing a phenol group or an acid anhydride group that functions as a polyaddition curing agent for epoxy resins. - The secondary or tertiary nitrogen contained in the repeating unit of formula [[1] functions as an anionic polymerization type curing agent for the epoxy resin, and at the same time polymerization proceeds between the phenol group or acid anhydride group and the epoxy group. Functions as a promoter of addition reactions.

The method for producing a latent curing agent for Evoquin resin of the present invention includes 10 repeating units represented by the general formula [1] in 0 molecules.
~50 mol% of polymeric substances.

It is characterized by reacting with an amine compound giving the formula [V].

The production of polymeric substances by reacting with each amine compound in Uni is 1, for example, by polymerization with the general formula [! ] can be produced by lanocal copolymerization of a monomer (monomer [l]) that provides a repeating unit of general formula [IV] and a monomer [■]) that provides a repeating unit of general formula [IV] .

Monomer [! ] Specific examples include ethylene, propyleno, 1-butene, inbutylene, nocropentene,
olefins such as hexane, vinyl chloride, and halogenolefins such as hynylidene chloride.

Fatty acid vinyl esters such as vinyl acetate, styrene.

Stereno compounds and vinyl ethers such as a-methylstyrene, vinyltoluene, and t-butylstyrene.

Co-Ir such as butadieno, isoprene, chloroprene, etc.
k diene, methyl acrylate, ethyl acrylate
Butyl acrylate-1, hequinol acrylate.

Ncrohequin acrylate 1, Denru acrylate,
Octadecylacryle-1, Hydroquine ethyl methacrylate, Metquin ethyl acrylate.

Acrylic acid esters such as grittle acrylate.

Methyl methacrylate, ethyl methacrylate.

Butyl methacrylate, hequinyl methacrylate.

/Chlohexyl methacrylate-1・, octadenyl methacrylate-1・, hydroquine ethyl methacrylate-1・
.

Metquinethyl methacrylate-1, methacrylic acid esters such as glycidyl methacrylate, acrylonitrile
1. Re J and meta re re
Nitriles such as ronitrile, acrylamides, vinyl ketones such as methyl vinyl keto/, phenyl vinyl ketone, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and itaconic acid, etc. Alternatively, they can be used in combination.

A specific example of monomer [IV] is maleic anhydride.

Examples include methyllyleic anhydride, 1,2-dimethylmaleic anhydride, ethylmaleic anhydride, phenylmaleic anhydride, and the like.

There is no particular restriction on the method of copolymerizing monomer [I] and monomer [■] (although any known method of radical copolymerization can be applied).

When producing the latent curing agent of the present invention, monomer [I]
A copolymer of the monomer [rV] and the monomer [rV] is reacted with an amine compound to imidize the acid anhydride residue.

The imidization reaction between a polymeric substance having an acid anhydride residue in its polymer chain and an amine compound is well known.

For example, Special Publication No. 61-26936 or Special Publication No. 62-
According to the method disclosed in No. 8456, a polymer substance and an amine compound are reacted to produce a latent curing agent having an imide group. Examples of amine compounds used when introducing repeating units are: ) ethylaminoethylamine, ethylaminoethylamine, diethylaminoethylamine. Methylaminopropylamine, dimethylaminopropylamine, diethylaminopropylamino, dibutylaminopropylamine, dimethylaminoethquinpropylamine, laurylaminopropylamine, jetanolaminopropylamine, N-aminoethylpiperino7. N-aminoethyl-4-pipecholine, N-aminoethyl-4-pipecholine
Chi rumorho ri no.

N-aminopropyl-2-pipecoline, N-aminopropylmorpholine, 4-puminoterpiverinone,
1-amino-4-methylbiperazine, N-aminopropylpiperazine, 2-aminopyridine.

3-aminobilinone, 4-aminobilidin, 2-picolilamino,
3-picolylamine, 4-picolylamine
, l -amino ethyl i midazole.

-aminopropylimidazole, 1-aminopropylimidazole, etc. Examples of amino compounds used when introducing the repeating unit of the general formula [1111 in the imidization reaction are as follows:
O-Ami) Phenol, M-Ami
Examples include nophenol and p-aminophenol.

Moreover, as an amino compound giving formula [V],
Methylamine, ethylamine, butylamine.

Hequinylamine, octylamine, decylamine.

There are alkylaminos such as dodenylamino and octadecylamine, and aromatic amines such as anilino, toluidine, naphthylamine, chlorophenylamino, dichlorophenylamino, bromophenylamine, and nobromophenylamine, and it is also possible to use ammonia.

The amount of the amine compound used is determined by the general formula [1'1. [11]
.

[111], [IV] and [V] are arbitrary within the numerical range of the repeating unit.

The imidization reaction can be carried out arbitrarily, and the desired imide compound is synthesized by reacting a polymeric substance containing an acid anhydride group with the above-mentioned amine compound in the presence or absence of a solvent. I can do two things. However, if a melt kneader such as a screenie extruder or a co-kneader Banbury mixer is used as a reactor and the imidization reaction is carried out in the molten state, the reaction can be carried out in 4 steps without using a solvent, so one reactor is required. It is industrially advantageous in that it requires little care and consumes less energy.In particular, if a co-kneader or screw extruder is used as the melt-kneader, it is easy to control the distillation time or reaction temperature. and
Moreover, since devolatilization is easy, unreacted amine, which causes a decrease in storage stability, can be efficiently removed, which is advantageous.

There are no particular restrictions on the screw extruder used for the imidization reaction, and any single-screw extruder or multi-screw extruder can be used, but a twin-screw extruder that rotates in the same direction or in different directions is particularly suitable for excellent extrusion operability. It is preferable that the extruder has an opening (ventro) for devolatilization (1) Usually, the pressure of the ventro is reduced by a vacuum pump. In particular, low-boiling point amine compounds are fed into the extruder from the (-drome).
When filling, it can be press-fitted with a metering pump.
The feeder does not necessarily need to be installed at the base of the screw; it can be installed in the middle of the barrel by supplying the polymeric substance from the base of the screw. It is possible. Also, when feeding raw materials from the same feeder,
Two or more types of raw materials can be mixed in advance using a mixer, etc.

The operating conditions of the melt kneader are arbitrary, but the degree of layering in one reaction is 10.
It is preferable to control the temperature within the range of 0 to 400°C, preferably 200 to 350°C.The reaction time is preferably 20 minutes or less.In addition, in order to prevent oxidative deterioration of the three reactants, the inside of the apparatus is heated with nitrogen, It may be replaced with an inert gas such as argon.

The imidization reaction does not require a particular catalyst, but if one is used, trimethylamine or triethylamine is used.

Tributylamine, N,N-dinothylaniline.

Tertiary amines such as N,N-dinothylaniline are preferred.

The imidization reaction can be carried out in a solution state using 9 reaction vessels. 1. There is no particular restriction on the reaction method, but to give a specific example, a polymeric substance containing an acid anhydride residue and the above-mentioned amine are used. The compound is dissolved in a solvent and the reaction layer degree is 50 to 250°.
React at C for 2 to 20 hours. A catalyst is not necessarily required, but both can be done using the above-mentioned tertiary amine catalyst.9
Reaction solvents include ketones such as amine, notyl ethyl ketone, methyl imbutyl ketone, and cyclohexanone;
Tetrahydrofuran, ethers such as 1,4-nooxano, and aromatic hydrocarbons such as toluene and chlorine.

Dimethylformamide, dimethyl sulfoxide.

Examples include N-methyl-2-pyrrolidone.

During the imidization reaction, an amine compound (for example, methylaminopropylamine) giving the formula [■], -
An amino compound (e.g., p-aminophenol) giving the formula [ml] and an amine compound (e.g., aniline) giving the formula [V, ] are simultaneously introduced into a raw polymer material having an acid anhydride group for imidization. Although it is possible to carry out the reaction, for example, it is also possible to add dimethelaminopropyleamine to react, and then add p-aminophenol and aniline to complete the reaction.
Ru.

Instead of monomer [IV], maleic acid, methylmaleic acid, 1.2-methylmaleic acid, etelmaleic acid,
Propyl maleic acid, phenyl maleic acid, aconitic acid, fumaric acid, methyl fumar@, I, 2-
(b) tylfumaric acid, ethyl fumaric acid.

A polymer material obtained by copolymerizing unsaturated dicarboxylic acids such as propyl fumaric acid, phenyl 7maru fIJi, and itaconic acid with a monomer [summer] is imidized with the above-mentioned amine compound to achieve the desired latent curing. It is also possible to synthesize agents.

Furthermore, as an alternative method, the latent curing agent for epoxy resins of the present invention can also be produced by copolymerizing each monomer.

That is, in addition to monomer [1] and monomer [fV].

− Monomer giving the repeating unit of the formula [■] (monomer [■]
), - by radical copolymerization of a monomer (monomer [I]) that provides a repeating unit of formula [I11] and - a monomer (monomer [V]) that provides a repeating unit of formula CVI There are two methods for producing the curing agent.

A specific example of the monomer [11] is N-(N.

N-nottylaminoethyl)maleimide, N-(N,
N-noethylaminoethyl)maleimide, N(N,N
-dimethylaminopropyl)maleimide, N-piperidinoethermaleimide, N-(4-piperidylethyl)
maleimi l'+ N-hiko11/L.

There are maleimides and the like, and these can be used alone or in combination.

Specific examples of the 111L-mer [11+1 include N-(4-hydroquinphenyl)maleimide and N-(2-hydroquinphenyl)maleimide.

Monomer [A specific example of V is maleimide.

N-methylmaleimide, N-ethylmaleimide.

N-butylmaleimide, N-hexylmaleimide.

N-noclohexynormaleimide, N-f”silmaley
Mid, N-) Eniruma Shiimi
N-tolylmaleimide, N-(chlorophenyl)maleimide.

N-(bromophenyl)maleimide, N-(dibromophenyl)maleimide, etc.

There are no particular restrictions on the method of copolymerizing the monomers [11, [■], [1111, [rV], and [V].

Any known method of lanocal copolymerization can be applied.

The latent curing agent of the present invention has the general formula [! ] 50 to 90 mol% of the repeating unit represented by the general formula [[1], and 0.0% of the repeating unit represented by the general formula [[1]]. 1 to 50 mol%, and 1 to 50 mol% of repeating units represented by the general formula CI[I].

0 to 50 mol% of repeating units represented by general formula [IV] and 0 to 50 mol% of repeating units represented by general formula [V]
is a polymeric substance having a general formula [i] in which the repeating unit of the general formula [i is less than 50 mol%.

Alternatively, if the sum of the repeating units of the general formula [■, [1+1], [IV] and [V] exceeds 50 mol%, it is practically preferable because the copolymer cannot be produced by an industrially possible method. In addition, the repeating unit of the general formula [I] exceeds 90 mol%, or the repeating unit of the general formula [1]
1] repeating unit is 0. If the content is less than 1 mol%, the curing speed of the composition will be slow when mixed with the polymeric epoxy resin. Not suitable due to poor storage stability.
Furthermore, if the repeating unit of general formula [I11] is less than 1 mol%, the cured product obtained by curing the composition will have insufficient heat resistance, and if it exceeds 50 mol%, the strength of the cured product will be insufficient. In addition, if the repeating unit of the general formula [1] is less than 50 mol%, or if the repeating unit of the general formula [V] and [V] exceeds 50 mol%, the strength of the cured product may deteriorate. It is preferable that the latent curing agent of the present invention, which is insufficient, has a glass transition temperature in the range of 50 to 250°C, preferably 70 to 200°C.If the glass transition temperature is less than 50°C, it is obtained by mixing with an epoxy resin. The storage stability of the composition is low, and the curing speed of the composition is slow when the temperature exceeds 250°C. Furthermore, the latent curing agent has a molecular weight of 400 to 200.0.
00. If the molecular weight is less than 400, the storage stability of the composition obtained by mixing with 1ft of epoxy tHl will be low, and if it exceeds 200,000, the composition will have poor storage stability. The curing speed is slow.The molecular weight referred to here is the weight average molecular weight based on polystyrene determined by the Gelvermien Sun Chromatograph (- method).

The latent curing agent of the present invention is mixed with an epoxy resin to provide an epoxy resin composition having latent properties, but the epoxy resin used is not particularly limited.

Known liquid or solid epoxy resins are optionally used. Examples of suitably used epoxy resins include glycidyl ether type epoxy resins such as bisphenol A diglycidyl ether type, novolac glycidyl ether We, glycidyl ether type epoxy resins such as hexahydrophthalic acid glycidyl ester, dimer acid glycidyl ester, glycidylamine type epoxy resins such as triglycidyl isocyanate and tetraglycidyldiaminodiphenylmethane; linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil;
Examples include ring group epoxy resins such as 3.4-epoxy-6-methylchlorohexylmethylcarpoxylate.

In the composition of the latent curing agent and epoxy resin of the present invention, the mixing ratio of the two is such that the molar concentration of the phenolic hydroxyl group in the curing agent is [OH], and the molar concentration of the phenolic hydroxyl group in the curing agent is [OH], The molar concentration is [N].

and the molar concentration of evoquine groups in the epoxy resin [E]
Here, it is preferable to adjust so that [OH/[E] is within the range of 0.01 to 2 and [N/[E] is within the range of 0.01 to 0.5.

If [OH] / [E] is less than 0.01, the effect of improving the heat resistance of the cured product will be insufficient, and if it exceeds 2, the crosslinking density will decrease, which is undesirable.

If [N]/[E] is less than 0.01, the curing rate of the composition will be insufficient, and if it exceeds 0.5, the storage stability of the composition will decrease, which is undesirable. In addition to the latent curing agent and epoxy resin of the present invention, the composition can contain other known curing agents, such as acid anhydrides, dinoandiamide,
Diaminomaleonitrile, imidazole compounds, dibasic acid dihydrazides, polyamine salts, guanamines.

Melamines, polyphenols, etc.

Furthermore, the epoxy resin composition of the present invention may contain known additives for epoxy resins, such as flexible plugging agents.

Impact modifiers, fillers, diluents, thixotropic agents, pigments, solvents, antifoaming agents, leveling agents.

It may contain a tackifier or the like.

[Function] The epoxy resin composition containing the curing agent of the present invention is easy to handle due to the excellent latent nature of the curing agent, and has a fast curing speed (and the cured product has excellent heat resistance, so
It is suitably used for adhesives, FRP, electrical and electronic device parts such as electronic device sealing materials, and various industrial parts.

[Example] The present invention will be explained in more detail with reference to Examples below.
All weights and percentages used in Examples and Comparative Examples are based on weight.

The methods for measuring various properties are as follows.

Molecular weight of other agents: Using a tetrahydrofuran solution as a sample, the weight average molecular weight based on polystyrene was determined by gel permeacyl chromatography.

Glass transition temperature of curing agent: Determined by differential scanning calorimetry using DSC-200 manufactured by Shichiiko Electronics Co., Ltd.

Pot life: A mixture of an epoxy resin and a curing agent was placed in a glass container, left in a constant temperature bath at 40° C., and the time until gelatinization was measured.

Curing time: Thermoehimica Acta
, 38(+980)+21131 R, L
According to the method of Miller et al., a mixture of an epoxy resin and a curing agent was charged into a DSC apparatus maintained at 160°C or 200°C, and the time for completion of the second heat generation was measured.

Glass transition temperature of cured product: A mixture of an epoxy resin and a curing agent was cast at 160°C or 200°C for 6 hours. The returned Tess piece was measured using a DSC-200.

Moreover, the origin of the sample used is as follows.

SMA Lennon: ^RCO Chemical Comp
A copolymer of styrene and maleinoic anhydride manufactured by nny Ltd. The copolymerization ratio of styrene and maleinoic anhydride is as follows.

5NIAIooO: l: 5MA2000 = 2: 5MA3000 = 3: 1 Bisphenol A type Evoquin resin: Epicote 828, manufactured by Yuka Nonyl Epoxy Co., Ltd. Evokin equivalent: 184~
194° Talesol novolak epoxy resin: Sumie Pokino ESCN-+95X Evoquin equivalent, manufactured by Sumitomo Chemical Co., Ltd. 190-205° Phenol novolac resin: Norunol BRG-556, manufactured by Showa Kobunshi Co., Ltd., phenol equivalent 103 Example 1. Comparative Example 1 30 parts of 5MA100O was charged into an autoclave, and 70 parts of chlorhexane was dissolved under pressure while flowing nitrogen gas, and then dissolved in an amount equivalent to 5.7 mol % based on the anhydrous maleic acid residue of 5MA100O. of N,N-dimethylaminopropylamine was added, the can was sealed, and the reaction was allowed to proceed at 140° C. for 6 hours with stirring. After cooling, the reaction solution was yellow and transparent.

Then, 8 for the maleic anhydride residue of 5MA100O
An amount of p-aminophenol corresponding to 9.3 mol% was added, and the reaction was further continued at 140°C for 12 hours. The reaction liquid after cooling was brown and transparent.

When the unreacted amount of the raw material amine contained in the reaction solution was quantified by gas chromatography, tr was quantitatively determined (the midization reaction was proceeding).

The polymer was recovered by pouring the reaction solution into 30 times the volume of ether, and vacuum-dried at 80°C to return a yellow powder.

The crushed powder was further finely ground in a mortar and sifted through a 200-mesh sieve to obtain a sample of what had passed through the mephium crystals (sample No. 13°). We conducted experiments and synthesized various curing agents (sample Nos. 2 to 11).The returned curing agent powder and bisphenol A type epoxy resin were mixed so that [OH] / [E] = 1. It was subjected to a hardening test.

Table 1 summarizes the synthesis conditions for the curing agent, and Table 2 summarizes the properties and performance of the curing agent.

It can be seen from Example 1 and Comparative Example 1 that the curing agent of the present invention provides a thermosetting resin composition having latent properties when mixed with an epoxy resin. Furthermore, it can be seen that the latent curing agent has a fast curing rate under curing conditions, and the cured product has excellent heat resistance.

Example 2 While flowing nitrogen gas into an autoclave, 65 parts of styrene and 50 parts of chlorohexanone were charged.

Raise the temperature to 83℃ while stirring.After the contents reach 83℃, #! Water maleic acid 35 parts, benzoyl peroxide 0. A solution of 1 part and t-dodecylmercaptan dissolved in degassed Nclohexanone 1509 was continuously added to the system over 8 hours.

Two hours after the start of continuous addition, the temperature of the contents was raised to 103°C, and after the continuous addition was completed, the temperature was raised to 115"C to complete polymerization.

The amount of [-dodecyl mercaptan added was 2 parts.

It was set as 4B or 6 parts.

The polymerization rate measured by gas chromatography was 95% for styrene and 99% for maleic anhydride.

The polymerization solution was cooled to room temperature and added with an amount of N corresponding to 154% based on the maleic anhydride residues of the polymer.

N-methylaminopropylamine, and 80%
of p-aminophenol was added, and the mixture was reacted at 140°C for 18 hours. After the reaction solution was cooled, it was pressurized into 30 times the amount of methanol to recover the polymer.

It was vacuum dried at 80°C. The crushed powder was ground in a mortar and sifted through a 200 mesh sieve, and the material that passed through the mesh crystals was used as a sample.

The obtained curing agent and bisphenol A type epoxy resin were mixed to give [OH]/[Econi 1, and the curing characteristics were evaluated. The results are summarized in Table 3.

As is clear from Table 3, the obtained mixture of curing agent and epoxy resin is a latent thermosetting resin composition.

Example 3. Comparative example 2 The reaction was carried out using a screw extruder.

The screw extruder used has a ventro.

It is a co-rotating two-wheel extruder, and the ratio of the effective length of the screw to the outer diameter, so-called L/D, is 25.

The hopper mouth is located at the base of the screw, and raw materials are fed into the hopper mouth by a screw-type quantitative feeder. The raw materials used were premixed in advance using a Hennel mixer.

Ventro is one, vacuum pump -600- intestinal Hg
The pressure is reduced to

Reaction coal making was carried out at 280° C., and the 4th distillation time was 2 minutes.

The output from the extruder is finely ground in a mortar.

The material was sieved through a 200-mesh sieve, and the material that passed through the mesh was used as a sample.

The obtained curing agent was mixed with a bisphenol A epoxy resin and subjected to various evaluations in the same manner as in Example 1.

The reaction conditions are summarized in Table 4, and the characteristics evaluation results of the curing agent are summarized in Table 5.

Suff 13, - The curing agent produced by reacting in an extruder has excellent storage stability and curing properties, similar to the curing agent produced in a 2-reaction can, and is also known to have excellent properties of the cured product. I understand. Furthermore, compared to the reaction using a single reaction vessel, the reaction time using a screw extruder is short (the single reaction operation is simple, and there is no need to separately process the product, which has industrial advantages. Example 4 Comparative Example 3 The curing agent produced in Example 3 was mixed with cresol novolac epoxy resin and the properties of the curing agent were evaluated. 7J
! If so, use a kneader and set the mixing temperature to 90 °C.
did.

For comparison, cresol novolac epoxy resin, phenolic novolac resin and 2,4.6-)11s(N,N
-dimethylaminomethyl)phenol [OR3/
[E] =0. 9. [N]
/ [E] = 0.06 ratio was prepared using a kneader, and the properties were evaluated. The results are summarized in Table 6. 1. The curing agent of the present invention has latent properties, and the heat resistance of the cured product is low. It can be seen that a curable composition with rich properties can be obtained.

[Effects of the Invention] As explained above, the curing agent of the present invention is a latent curing agent that has significantly improved storage stability, which was a drawback of conventional curing agents for Evoquin resin. Furthermore, the latent curing agent of the present invention overcomes the drawbacks of conventional latent curing agents, such as high curing temperature and low heat resistance of the cured product. Therefore, the composition comprising the latent curing agent and EBOKI/LTI resin of the present invention eliminates the complexity of handling, which was a drawback of conventional EBOKI resin, and can produce a cured product with high heat resistance at a low curing temperature. able to give

Claims (1)

[Claims] 1. 50 repeating units represented by the general formula [I] in the molecule
~90 mol%, repeating unit represented by general formula [II] 0.
1 to 50 mol%, 1 to 50 mol% of repeating units represented by general formula [III], 0 repeating units of general formula [IV]
A latent curing agent for epoxy resins comprising a polymeric substance having ~50 mol% and 0~50 mol% of repeating units represented by the general formula [V]. General formula [I] General formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc.▼ General formula [III] General formula [IV] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc.▼ General formula [V] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R1, R2, R3, R4, R6, R7, R8,
R9, R10, R11, R12 and R13 are a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and R5 is an alkylene group, a cycloalkylene group, a phenylene group or -R14- (however, R14 is -O-,
cycloalkylene group or phenylene group), Y represents an organic group containing secondary and/or tertiary nitrogen, α is an integer of 0 or more, β is an integer of 1 or more, and α+β =5. ) 2. 50 repeating units represented by the general formula [I] in the molecule
~90 mol% and 1 repeating unit represented by general formula [IV]
A polymer substance having 0 to 50 mol% is reacted to form the general formula [
Latent curing for epoxy resin according to claim 1, characterized in that the latent curing for epoxy resins is made to react with an amine compound giving general formula [II], an amine compound giving general formula [III], and, if necessary, an amine compound giving general formula [V]. Method for manufacturing the agent. 3. A latent epoxy resin composition comprising an epoxy resin and the latent curing agent according to claim 1.