JPS5853916A - Thermosetting epoxide resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curing method and a cured product obtained by this method.

Epoxide resins, i.e. more than 1 on average per molecule,
It is known that materials containing 2-epoxide groups can be cured by reaction with a wide variety of materials to form crosslinked, infusible, insoluble products with valuable industrial properties.

U.S. Pat. No. 5,386,956 discloses a compound having the following formula: R1 represents a methyl group or a hydroxyethyl group, n represents an integer from 2 to 5, and X represents 1Oc) (
, , -Cll, -H, -CHs or one NO,
The curing of epoxide resins with urea represented by the group ) is disclosed.

The patent also discloses that the curing effect of these agents can be enhanced by adding dicyandiamide, stearic acid hydrazide, adipic acid dihydrazide, succinimide or cyanoacetamide to the curable composition.

According to the patent, the use of such urea overcomes the disadvantages associated with prior art curable epoxide resin compositions, namely, the use of curing agents such as dicyandiamide requires relatively high temperatures and relatively long curing times. 1, while in other cases the use of reactive curing agents or curing accelerators overcomes the disadvantage that they can cause premature curing at room temperature, ie they are not sufficiently latent.

U.S. Patent No. 5,660,516 VC describes 1-cyano-
3-(lower alkyl)-guanidine also has the formula ■ or 1
It is disclosed that the curing of epoxide resins by bisurea of v.

Urea of the above formula, especially N-(4-chlorophenyl)-N
', N'-dimethylurea and 2,4-bis(N.

N-dimethylureido) toluene is not only used commercially by itself to cure epoxide resins, but also as a curing accelerator for epoxide resins containing dicyandiamide.

However, due to the increasingly stringent requirements for curable compositions to have a long shelf life at room temperature but to cure rapidly at moderately high temperatures (e.g. 100°C), the above-mentioned urea replacement is It's in demand now.

The inventors have now discovered that certain phenolic ureas substantially meet these more stringent requirements.

Accordingly, the present invention provides a thermosetting composition comprising: (al and (bl): (al) epoxide resin; It represents a cycloalkyl, alkenyl, cycloalkenyl, or haalalkyl group, and these groups may be substituted with a chlorine atom (preferably a chlorine atom), a hydroxyl group, or a cyano group, provided that R2 is or a hydrogen atom. It can also represent
Further, R2 and R8 together with the bonded nitrogen atom represent a heterocycle containing 5 to 5 carbon atoms and optionally one oxygen atom in the ring, and R4 is -NHt, NO2, C6, Dr or an argyl group having 1 to 10 carbon atoms, 2, and p does not represent 0, 1 or 2].

Further provided is a method of curing an epoxide resin comprising heating the thermosetting composition of the invention, and a cured epoxide resin obtained by this method.

N-(2-hydroxyphenyl)-N,N'-dimethylurea and other ureas of formula V are substituted by N-(4-chlorophenyl)-N',N'-dimethylurea and
, N-dimethylureido) l-luene is that the former has the advantage over more common compounds such as 2,2-bis(4-(glycidyloxy)phenyl)propane and baboon(4-(diglycidylamino)phenylmethane) It melts in the epoxide resins used in
℃ for 3 to 4 weeks without gelation and at room temperature (20° to 25℃)
) to produce a stable solution with a shelf life of more than 6 months. In the case of the two aforementioned ureas previously used for this purpose, it was necessary to heat the epoxide resin to 100° to 120°C to form a solution, and such heating prematurely degraded the mixture. Easy to gel.

In formula V, each of R2 and R3 is preferably a C1 -C alkyl group, a C2 -C4 alkyl group,
hydroxyalkyl group, C3-C7 cycloalkyl group, C2-C4 alkenyl group,
Or it represents an aralkyl group having 7 to 9 carbon atoms.

Particular examples of suitable groups R2 and R3 are methyl, ethyl, n
- furovyl, tert-butyl, cyclohexyl, 4-methylcyclohexyl, allyl, 2-hydroxyethyl, and benzyl groups. % is preferred for R2 and R3
are each a methyl group or compounds in which R2 is a methyl group and R3 is a 2-hydroxyethyl group: these compounds are particularly effective promoters for dicyandiamide. When R2 and R3 together with the tynn atom to which they are attached represent a heterocycle, the heterocycle may be, for example, a piperidino, morpholino or pyrrolidino ring. That is, R2 and R3 together with the chlorine atom represent a group represented by the following formula (2) (-).

Compounds other than those in which each of R2 and R3 is a group other than a methyl group, and R2 is a methyl group and R3 is a 2-hydroxyethyl group have low reactivity with epoxide resins and are therefore, for example, very It is useful as a thermosetting agent in the production of cast articles where rapid onset of curing action (and generation of significant heat of reaction) can be detrimental.

Preferably, p is 0. or 1 and R4 is -No
t, -C1 or -Br, or p is 2 and R4 is a methyl group.

Particularly preferred compounds of formula V include N-(2-hydroxyphenyl)-N',N'-dimethylurea, N-(2-hydroxy4-nitrophenyl)-N',N'-dimethylurea, N -(4-chloro-2-hydroxyphenyl)-
N', N'-dimethylurea, N-(5-chloro-2-hydroxyphenyl) -N', N'-dimethylurea,
N-(2-hydroxy-5-nitrophenyl)-N',
N'-dimethylurea, N-(3,5-dimethel-2-hydroxyphenyl)-N', N'-dimethylurea, N-
(2-hydroxyphenyl)-N'-methyl-N'-(
2-hydroxyethyl)urea, Oyohi N-(4-chloro-2-hydroxyphenyl)-N'-methyl-N'-
(2-hydroxyethyl)urea.

The composition may include a thermosetting amount of the component (bl), i.e., the formula
Urea is the only hardening agent. In such cases, 3 to 25 parts per 00 parts by weight of epoxide resin (alt.
Parts by weight will be used, preferably 5 to 20 parts by weight.

Hydroxyphenylurea (bl is a generally known type of compound, and in formula (■), R4 is -CH3 or -No,
, p is 0, 1 or 2, and R2 and R3 each represent an aliphatic group of 1 to 4 carbon atoms (although one may be a hydrogen atom), as described in U.S. Pat. No. 2,795,6.
No. 10 as a fungicide, protozocide and algaecide. They are prepared according to the method described in the above-mentioned US patent by converting benzaxaxacylinone of the formula:
and in X, R2, R3, R4 and p have the meanings given above), such as methylamine, dimethylamine, diethylamine,
N-methylbenzylamine, piperidine, morpholine,
It can be produced by heating with pyrrolidine, diallylamine, N-methylcyclohexylamine, and N-methylethanolamine. The benzoxacillinones can, in turn, be obtained in known manner by heating suitably substituted 0-amine phenols with urea or by nitration, chlorination or bromination of the benzoxacylinones themselves.

However, if it is desired to use a compound of formula V in which R' is an amino group, this is better prepared by preparing the corresponding nitro-substituted benzoxacylinone and reducing it.

The inventors have further discovered that dicyandiamide, melamine, carboxylic acid hydrazides, and certain other compounds promote thermal curing of epoxide resins with ureas of formula V
-1.

Accordingly, there is also provided by the present invention a thermosetting composition containing the following components (cl): (cl component (divided based on the weight of BL)) - with a small amount by weight of dicyandiamide, carboxylic acid hydrazide, succinimide, cyanoacetamide, 1-cyano-
A thermal curing accelerator selected from 6-(lower alkyl)guanidine (the lower alkyl group containing up to 3 carbon atoms), imidazole, and salts of carboxylic acids and tertiary amines. Ingredients (bl and (c) Vi - together with ingredient (a)
2, typically both contain 5 to 25 parts by weight per 100 parts by weight of epoxide resin (a).

The inventors have now discovered that urea of Formula V facilitates the thermal curing of epoxide resins with dicyandiamide, melamine, carboxylic acid hydrazides, and certain other compounds.

Accordingly, there is provided by the present invention a thermosetting composition further comprising the following components (dl): (d) dicyandiamide, melamine, carboxylic acid hydrazide, succinimide, in a major amount calculated based on the weight of component element bj; Cyanoacetamide, 1-cyano-
A thermosetting agent for epoxide resins selected from 3-(lower alkyl)guanidine (the lower alkyl group containing up to 5 carbon atoms), imidazole and salts of carboxylic acids and tertiary amines. The component (dl and (bl) are together the component (
The thermosetting amount for a) is 7 and typically both are 5 to 2 parts per 100 parts by weight of epoxide resin (B).
Contains 5 parts by weight.

Epoxide resins that can be used in these compositions preferably have the formula
I: (In the above formula, each of RS and R7 represents a hydrogen atom and R6 represents a hydrogen atom or a methyl group, or R6 and R7 together represent a -CH, -CH, - group) . and R6 represents a hydrogen atom).

Examples of such resins include polyglycidyl obtained by reacting a compound containing two or more carboxylic acid groups per molecule with epichlorohydrin, glycerol dichlorohydrin, or β-methylepichlorohydrin in the presence of an alkali. and poly(β-methylglycidyl) esters. Such polyglycidyl esters are aliphatic polycarboxylic acids such as oxalic acid,
Succinic acid, curtaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, or dimerized or trimerized lylunic acid; cycloaliphatic polycarboxylic acids, such as tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid acids, hexahydrophthalic acid, and 4-methylhexahydrophthalic acid; and aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid.

Another example is to react a compound containing at least two free alcoholic hydroxyl groups and/or phenolic hydroxyl groups per molecule with a suitable epichlorohydrin under alkaline conditions or in the presence of an acidic catalyst. ,
Polyglycidyl and poly(Cβ-methylglycidyl)ether obtained by subsequent treatment with an alkali. These ethers are acyclic alcohols, e.g.
Ethylene glycol, diethylene glycol and higher poly(oxyethylene) glycol, propane-1,2
-Diols, poly(mequinpropylene) glycol, dipan-1,5-diol, butane-1,4-diol, poly(oxytetramethylene) glycol, pentane-1,5-diol, hexane-1,6- diol, hexane-2,4,6-)triol, chrycerol,
1,1.1-) I7 Methylolpropane, pentaerythritol, nrubitol and polyepichlorohydrin; cycloaliphatic alcohols, e.g. -hydroxycyclohexyl)propane and 1,1-bis(hydroxymethyl)cyclohex-5-ene; and alcohols with aromatic nuclei, such as t,N,N-bis(2-hydroxyethyl)aniline and p,p'- Bis(2-hydroxyethylamino)
Can be produced from diphenylmethane. or they are mononuclear phenols such as resorcinol and hydroquinone; and polynuclear phenols such as bis(4-hydroxyphenyl)methane, 4,4'-dihydroxydiphenyl, bis(4-hydroxyphenyl)sulfone, 1,1,
2.2-tetrakisC4-hydroxyphenyl)ethane, 2.2-bisC4-hydroxyphenyl)propane, 2.2-bis(5,5-)bromo-4-hydroxyphenyl)furopane, and formaldehyde, acetaldehyde, Aldehydes such as chloral and furfuraldehyde, as well as phenols themselves and phenols whose rings are substituted with chlorine atoms or alkyl groups each containing 9 carbon atoms, such as 4-chlorophenol, 2-methylphenol and 4- Preparation 1-1 is obtained from a novolak formed from a phenol, such as tert-butylphenol.

Poly(N-glycidyl) compounds include, for example, epichlorohydrin and amines containing at least two amino-hydrogen atoms, such as aniline, n-butylamine, bisC4-
compounds obtained by dehydrochlorination of the reaction products with triglycidyl isocyanurate and cyclic alkylene ureas,
Examples include ethylene urea and 1<3>-propylene urea, and N,N'-diglycidyl derivatives of hydantoins such as 5,5-dimethylhydantoin.

An example of a poly(S-glycidyl) compound is ethane-1,2
- dithiols and di-S-glycidyl derivatives of dithiols such as bis(4-mercaptomethylphenyl) ether.

An example of an epoxide resin having a group 2M in which R5 and R7 are combined to represent a -CH2-CH2- group is bis(2,
3-epoxycyclobentyl) ether, 2,6-nipoxycyclopentyl glycidyl ether and 1,2-
Bis(2,3-epoxycyclobentylmexy)ethane.

Epoxide resins having 1,2-epoxide groups attached to different types of heteroatoms may be used, for example N,N,0-triglycidyl derivatives of 4-aminephenol,
Glycidyl ether-glycidyl ester of salicylic acid, N-glycidyl-N'-(2-glycidyloxypropyl)-5°5-dimethylhydantoin, and 2-cricidylmexyl-1,3-bis(515-dimethyl-1
-glycidylhydantoin-3-yl)propane.

Mixtures of epoxide resins can be used if desired.

Preferred epoxide resins are polyglycidyl ethers, polyglycidyl esters, N,N'-diglycidylhydantoins and poly(N-glycidyl) derivatives of aromatic amines. A particular preferred resin is 2,2-bis(4-
formed from hydroxyphenyl)propane, bisC4-hydroxyphenyl)methane or formaldehyde and phenol or a phenol whose ring is substituted with one chlorine atom or one alkyl hydrocarbon group containing from 1 to 9 carbon atoms, and at least 0.5 equivalents of 1/kg
, 2-epoxide content of novolacs; bis(4-(diglycidylamino)phenyl)methane, and p-(diglycidylamino)phenylglycidyl ether.

When the accelerator (cl or main hardener fdl) is a carboxylic acid hydrazide, it is preferably stearic acid hydrazide, oxalic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide or inphthalic acid dihydrazide.

Accelerator (cl) or main curing agent (di is 1-cyano-6-
(lower alkyl)guanidine, it is 6
-methyl, 3,3-dimethyl or 3,3-diethyl compounds are preferred.

When the accelerator (c) or the main curing agent (a) is an imidazole, it is preferably 1-phenylimidazole, N-methylimidazole or 2-ethyl-4-methylimidazole.

If the accelerator (c) or the main curing agent (dl) is a salt of a carboxylic acid and a tertiary amine, it is a salt of a hydroxycarboxylic acid such as lactic acid or salicylic acid.
) Lis(dimethylaminomethyl) is a salt with a Mannich base such as phenol.

(e) Usually, the accelerator (c) is urea (b) 1 per 1001 parts
12 present in proportions of 0 to 50 parts by weight, and urea (b
) is a curing agent (d), an accelerator and 1. If used in a commercially available manner, it would be present in a proportion of not more than 25 parts by weight per 100 parts by weight of component (d).

The novel compositions furthermore contain suitable plasticizers, such as dibutyl phthalate and dioctyl phthalate; inert diluents, such as tar and bitumen; and so-called reactive diluents, in particular monoeboxides, such as n-butyl glycidyl ether, iso-octyl glycidyl needle, May include phenyl glycidyl ether, cresyl glycidyl ether, glycidyl esters of mixed tertiary aliphatic monocarboxylic acids, glycidyl acrylate, and glycidyl methacrylate. They are additives such as fillers; reinforcing materials; polymeric reinforcing agents such as polyether sulfones, phenoxy resins and butadiene-acrylonitrile rubber; coloring substances, flow control agents,
May include flame retardants and mold release agents.

4 Suitable extenders, fillers and reinforcing materials are, for example, glass fibers, carbon fibers, fibers of aromatic polyamides, barocini, mica, quartz powder, calcium carbonate, cellulose, kaolin, wollastonite, colloidal materials with a large specific surface area. silica, powdered poly(vinyl chloride), and powdered polyolefin hydrocarbons such as polyethylene and polypropylene.

The curable compositions of the invention can be used in combination with laminating resins, impregnating and casting resins, powder coatings, molding compositions, putty and sealing compounds, casting encapsulation and insulation compounds for the electrical industry. It can be used in particular as a primer for adhesives and adhesives.

The composition of the invention can be prepared at temperatures between 100°C and 180°C, especially at 10°C.
It is difficult to harden it by heating it to temperatures between 0℃ and 130℃. Typically, 30 to 120 minutes of heating is sufficient to achieve cure.

The following examples illustrate the invention.

1 part I is 1 part I by weight.

5 Used in these examples 1. The urea is as follows: 1. Prepared by: Tilurea benzoxacylinone (2ooy) was stirred with 33% dimethylamine solution in construction alcohol at 50° C. for 48 hours. The alcohol and unchanged dimethylamine were distilled off under reduced pressure at temperatures below 60°C and the product was dissolved in inpropanol and light petroleum ether (
It was recrystallized from a 1:1 volume ratio mixture with boiling point = 60° to 80°C). Part 1 is the Kofler bench.
Measured on bench) 1. and melted at 148°C (decomposition), fr.

Benzoxacillinone (25t) was added portionwise to concentrated nitric acid (N2O-) heated to 50°C at a rate such that the temperature was maintained at about 50°C. After the addition is complete, heat the mixture to 50°C.
Stir for 20 minutes at 7 and then pour into water (1 t). Separation i* The 6-nitrobenz di-oxacillinone was removed, washed with water and then dried at 100° C. under reduced pressure. Its melting point was 248°C.

The nitro congener 2 of
671 to convert to urea.

Urea (1,67 mol) and 2-amino-4-chlorophenol (nomole) were mixed together at 180°C under nitrogen for 2 hours.
heated for an hour. The melt is then cooled to 100°C, 1. N
-Hc-120a ml was thoroughly processed, 5-chlorobenzoxacylinone was distilled off, washed with water, and dried under reduced pressure (15IIJ) at 100°C.1. Ta. Its melting point after recrystallization from water was 185°C. By heating this benzoxazolinon (2639) with alcoholic dimethylamine as described above,
It was converted to the desired urea. The urea is made of iso7popanol and pumice ether (boiling point 60°-80°C).
After recrystallization from a 1=1 volume ratio mixture of
It had a temperature of 2°C.

j:i is obtained by fusing 2-amino-4-nitrophenol with urea in a manner similar to that for the 5-chloro-2-hydroxyphenyl congener to obtain 5-nitropenzocazolinone (melting point, Recrystallization of f & 215° C.) was formed 15 and then prepared by heating with alcoholic dimethylamine as described above 7 without forming diagonal crystals.

It is prepared from 2-amino-4,6-dimethylphenol, urea and dimethylamine in the same manner as for the 5-chloro-2-hydroxyphenyl analog.1. the law of nature.

The intermediate benzoxasilinone was not recrystallized. The urea is recrystallized from an alcohol reaction medium at 140°C (decomposition).
It had a melting point of

Benzoxacillinone was converted to the 6-chloro derivative by chlorination in acetic acid, which was then treated with dimethyl in technical alcohol as described above [7]. The melting point of the urea was 178°C (decomposed).

N-(2-Hydroxyphenyl)-N,N-diethylureabenzoxacylinone (1 mol) was prepared with 2 mol of diethylamine (dissolved in technical alcohol) at 50°C for 4 hours.
Stirred for 8 hours, then alcohol and excess diethylamine were distilled off under reduced pressure below 60°C. The residue was taken up in acetone and the desired product was precipitated by adding water, then disturbed and dried under reduced pressure at 80°C.

Stirring benzoxacillinone (1 mol) with 2 mol of piperidine dissolved in methanol at 50° C. for 48 hours.1. Ta. After evaporating and cooling some of the melted sister,
Although the product was copper mine, the grain was used directly.

N-(2-hydroxyphenyl)-N-methyl 11 Benzoxacillinone (1 mol) was dissolved in methylamine (25
The desired urea crystallizes on cooling; It has a melting point of 160°C (decomposition).

Benzoxacylinone (202y) and N-methylethanolamine (133f) were stirred and heated to 75°C.
Heat for 6 hours at 17, then cool to 65 °C (-1 and methanol (5 oi) was added. The mixture was cooled to ambient temperature at 1
．． At L7, diethyl ether (7504) was added. The precipitate was removed and recrystallized from methanol to yield the desired urea with a melting point of 128° C. (decomposed).

Urea 6-chloropenzoxazolinone (20F) and N-methylethanolamine (17,7F) in methanol (40+117) were stirred and then heated to 65°C for 6 hours. The mixture was cooled to ambient temperature, removed, and the residue was washed with diethyl ether to 178°C (decomposition).
The desired urea was formed and melted at .

Benzoxacillinone (4sr) was dissolved in chloroform (400rnt) at 50°C and bromine (26,6
3y) was added dropwise. The mixture was left at room temperature for 16 hours and 6-prompenzoxazolinone (melting point 172°C)
crystals) were taken away.

31" 6-prombenzoxazolinone (351y) 38 tidimethylamine in total methanol 60° with 55 g
Stir at C for 21 hours [7 hours]. Cool the mixture and drink 1. , washing the precipitate with cold methanol yields the desired urea (I
Z9f), melting point 178°C (min M) produced 1. Ta.

I epoxide resin 1y has a 1.2-epoxide content of 5.16% and a viscosity at 21°C of 2.
4.5 pas.

Epoxide resin 11N refers to bis(4-(cydaricidylamino)phenyl)methane containing 1.2-epoxide per kilogram of aO.

Accelerating effects are indicated by a reduction in the time for the composition to gel before curing, as is conventional in the art. Unless otherwise stated, genotoxicity was measured by placing the mixture approximately α12 on a metal block heated to the indicated temperature and observing the time required for gelation to occur [7].

2 Example 1 This example H1N-(2-hydroxyphenyl)-N,N-
Figure 2 shows the curing effect on Epoxide Resin I as indicated by gelation time (in minutes unless otherwise stated) at various concentrations and at various temperatures when dimethyl urea is added by roll mixing at room temperature.

Example 2 N-(2-hydroxyphenyl)-N,N-dimethylurea was added in various proportions to epoxide resin (1) heated to 70-80°C. It melted easily. Gel time at various mixture temperatures (minutes unless otherwise stated)
is as follows: 13 The knee that was there is Tess) l- represents that there was no.

In an illustrative example, a composition of the invention is heat cured and used to form an adhesive joint.

1.63. Thick and %2L 73Alclad #
Degrease the aluminum alloy sheet obtained under the indication of
British Ministry of Abigny John
Aircraft Process Svesification (B
ritish Ministry of Aviati
on4 Aircraft Process 5specific
ation) Pickle according to the specifications of DTD-9t5B,
Washed under running water and dried (#Alclad#
is a registered trademark. ) 100 parts of epoxide resin, N, (
A mixture consisting of 2.5 parts of 2-hydroxyphenyl) (passed 200 meshes, British Standard 410) and 0.5 parts of a commercially available chickentrope agent containing asbestos was prepared by three-roll mixing and in one stack. Fitting 2.54
cm Xl, 27 crn, the mixture was cured by heating to 120° C. for 1 hour.

The shear force of the bond was 25 MpB.

Example 4 The following mixture was prepared using a three-roll mixer. Numbers represent parts: 5 The proportions of each urea were chosen to correspond to an equal amount of dimethylamine. This is because (although the application of the present invention does not depend on the truth of this idea), the urea used in the composition of the present invention 6 is decomposed by heating to form dimethylamine (both R1' and R8 are methyl). group) or the corresponding secondary amine (when both R9 and B, s are not methyl groups)2, which is believed to act as a softener by reacting with the epoxide resin. It is.

The gelation times of these mixtures at various temperatures are as follows (times are in minutes unless otherwise specified): Knees were not tested.

It can be seen that the compositions of the invention (mixtures A-F) gel more rapidly at 120°C than the conventional compositions (mixtures G and H), but have a desirable long shelf life at room temperature. .

Example 5 In this example, the thermal deformation point of a cured epoxide resin composition obtained using urea of formula Compare with Nosone. 〃Martens value #
The terms D, 1. N, represents the value obtained by the modified method of the method 7, here (D, 1.N.

Specimen size specified by law: 1'20 fin x 15m 5 x 10
Compare with [,te] small sample, i.e. 76×19+1a
Using a sample of X3.2 yua and (1), 1. Compare with 4900Kpa specified in N. [7] 1225Kpa
The maximum fiber stress of was used. The results obtained by which modification method are D, 1. N, which is only an approximation of the result obtained with the method, provides the results obtained when compared with each other. “
A solution containing N-(2-hydroxyphenyl)-N',N' dimethylurea (1r) in epoxide resin 1102 was prepared by heating to 60°C, and the sample was cast onto a 100. and then heated to 150° C. for 1 hour to cure.

The marten value l of the cured sample was 110°C.

For comparison, N-(4-chlorophenyl)-N'-N'-
The procedure was repeated using dimethylurea 11 [7], but it was necessary to heat the mixture to 100° C. to dissolve the urea. The cured sample was somewhat kneeling and its l-marten value was 89°C.

The examples in the Examples illustrate the acceleration by dicyandiamide of the curing of epoxide resins by urea of formula (1).

The following composition was prepared by mixing on a three roll mill. Numbers represent parts. It can be seen that the addition of dicyandiamide reduces the gelation time without reducing the shelf life.

*Example 7 of a product using commercially available asbestos as the base material 7 This example illustrates the acceleration of curing of an epoxide resin by dicyandiamide with urea represented by formula V7 and shows that the urea is as effective as conventional urea. shows.

The following compositions were prepared on a three-roll mill, where the numbers represent parts: 9 It can be seen that the composition of the present invention gelled more rapidly than the conventional one (M, 0.P).

Example 8 1100 parts of epoxide resin, N-(2
A composition prepared by mixing 16 parts of -hydroxyphenyl)-N',N'-pentamethylene urea and 5 parts of the thixotropic agent used in Example 6 gelled at 120 DEG C. in 68 minutes.

Example 9 Prepared as in Example 8, but with N-(2-1 4[)hydroxyphenyl)-N',N'-dimethylurea 14
．． An aliquot of the composition containing 4 parts did not gel after heating at 90° C. for 2 hours, whereas another aliquot heated to 120° C. gelled in 67 minutes.

Example 10 An aliquot of a composition prepared as in Example 8 but containing N-(2-hydroxyphenyl),/-methyl [12 parts') did not gel after heating to 120° C. for 31 hours. However, another aliquot heated to 170°C gelled in 16 minutes [7].

Example 11 1100 parts of epoxide resin, N-(2
-Hydroxyphenyl)-N'-methyl-N'-(2-
A composition prepared by mixing 25 parts of hydroxyethyl) urea and 5 parts of the thixotropic agent used in Example 6 gelled in 152 minutes at 120°C.
It had a shelf life of 21 days at 40°C.

Example 12 The ureas used in Example 11 were converted to N-(4-chloro2-2-hydroxyphenyl)-N'-methyl-N' (
Example 11 was repeated, substituting 25 parts of 2-hydroxyethyl)urea. After 24 minutes at 120°C, the mixture
After 110 minutes at 100°C, gelation occurred. That is 4
It had a shelf life of 40 days at 0°C.

Example 13 The urea used in Example 11 was converted to N-(4-bromo-2-hydroxyphenyl)-N',N'-dimethylurea18.
Example 11 was repeated substituting 5 parts. The mixture is 1
Gelation occurred after 15 minutes at 20°C and 66 minutes at 100°C. It had a shelf life of 40 days at 40°C.

Example 14 Epoxide resin 1 (100 parts), N-
(2-Hydroxyphenyl)-N', N'-dimethyl amount of accelerator was mixed. Gelation time: 1. Heating to 120°C in an oil bath. The onset of gelation was determined by placing 1 volume of the sample in a test tube 3 and manually measuring the onset of gelation. Details of accelerators and gelling times are shown in the table below.

/14

Claims (8)

[Claims] (1) (al epoxide resin, and (bl) an effective amount of the following formula V: (wherein R' and R3 each represent an alkyl, cycloalkyl, alkenyl, cycloalkenyl, or aralkyl group; It may be substituted with a halogen atom, a hydroxyl group or a hasyanic group, provided that R2 can also represent a hydrogen atom, or R2 and R3 together with the nitrogen atom to which they are bonded have 5 to 5 Represents a heterocycle containing a carbon atom and optionally one oxygen atom in the ring, R4 represents -NH2, -Not, -Cl, -Br or an alkyl group having 1 to 10 carbon atoms12, and p represents 0.1 or 2) A thermosetting composition containing urea represented by: (2) Each of R2 and R3 is an alkyl group having 1 carbon atom, a hydroxyalkyl group having 2 to 4 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, or a cycloalkyl group having 2 to 4 carbon atoms. A composition according to claim 1, which represents an alkenyl group or an aralkyl group having 7 to 9 carbon atoms. (3) The composition according to claim 1, wherein each of R2 and R3 represents a methyl group, or R2 represents a methyl group and R3 represents a 2-hydroxyethyl group. (4) Does p represent 0 or 5? ke p represents 1 and R4 is -NO? , -CA or -Br,
Alternatively, the composition according to claim 1, wherein p represents 2 and R4 represents a methyl group. (5) The urea represented by formula V is N-(2-hydroxyphenyl)-N',N'-dimethylurea, N-(2-hydroxy-4-nitrophenyl)-N',N'-dimethylurea , N-(4-chloro-2-hydroxyphenyl)-
N', N'-dimethylurea, N-(5-10-2-hydroquinophenyl)-N', N'-dimethylurea, N
-(2-hydroxy-5-nitrophenyl) -N',
N'-dimethyl urea, N-(5,5-dimethyl-2
-hydroxyphenylj-N', N'-dimethylurea,
N-(2-hydroxyphenyl)-N'-methyl-N'
-(2-hydroxyethyl)urea-cross-N-(4-chloro-2-hydroxyphenyl) -N'-methyl-N'-
The composition according to claim 1, which is (2-hydroxyethyl)urea. The composition according to claim 1, in which component (6) (relative to al [7] contains urea represented by formula V of the thermosetting agent □). (7) fcl Calculated based on the weight of urea in formula V [7
small amounts by weight of dicyandiamide, carboxylic acid hydrazide, succinimide, cyanoacetamide, 1-
cyano-3-(lower alkyl)guanidine (the lower alkyl group contains 3 carbon atoms), imidazole,
and a heat cure accelerator selected from salts of carboxylic acids and tertiary amines, wherein components (b) and (cl) together constitute the heat cure amount relative to component (a). The composition according to item 1. (8) fdl The majority of dicyandiamide, carboxylic acid hydrazide, calculated based on the weight of urea of formula V,
Succinimide, cyanoacetamide, 1-cyano-3
-(lower alkyl)guanidine (the lower alkyl group is 1
3 carbon atoms), imidazole and a salt of a carboxylic acid with a tertiary amine; The composition according to claim 1, which constitutes a cured amount.