JPH0480227A - Curing agent for epoxy resin - Google Patents

Abstract

PURPOSE:To prepare a coating compsn. which cures quickly at a relatively low temp. and gives a coating film improved in resistance to scratch and abrasion by compounding an epoxy resin with a modified amine condensate obtd. by condensing a phenol, a bicycloheptanediaminomethyl, and an aldehyde. CONSTITUTION:A phenol (e.g. phenol), a bicycloheptanediaminomethyl (e.g. 2,5-endo, exo-bicycloheptanediaminomethyl), and an aldehyde (e.g. fromaldehyde) are condensed in a molar ratio of 1: 0.3-3: 0.3-3 at 10-150 deg.C to give a modified amine condensate, which is compounded into an epoxy resin as a curing agent in an amt. contg. an amino active hydrogen of 0.5-1.5 equivalents based on one epoxy equivalent of the resin, giving a coating compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION = Industrial field of application: The present invention relates to a curing agent for epoxy resin, a coating composition containing the same, and a flooring material.

2. Conventional technology: In recent years, Evokin resin has been used in various types including coarse (king type, adhesive side,
It is used in a wide range of applications, including civil engineering and construction, under a variety of curing conditions.
A common method of use is curing at room temperature.

2. Problems to be solved by the invention: Applications such as lining, coating, adhesion, civil engineering and construction; 2. Even in winter, for example, at low temperatures of 0-5°C
There has been an increasing demand for a curing agent for Nibony-2 resin, which cures Kami-Ya-Rikkyumi-2 Evokino resin and provides a cured product with good physical properties.

Evoquino resin can be cured quickly even at low temperatures with a curing agent and L, and modified amines (amine adducts, e.g., amines with green or ether added), amines and and O mixtures are known.

However, epoxy resins cured with these curing agents are very hard and brittle.

For this reason, when used as a flooring material, it has a poor walking feel and is prone to cracking due to impact from falling heavy objects.

In addition, in order to obtain a cured epoxy resin that reacts quickly at low temperatures and is highly flexible, we added polyamide amine, which is known as a flexible curing agent, to the shell.
It has also been proposed to use curing agents containing curing accelerators such as phenols and tertiary amines.

In this case, large amounts of muco and curing accelerator are added to speed up the curing speed at low temperatures, which worsens the water resistance of the cured product and causes coating defects such as pinholes and repellency when applied. easy.

On the other hand, mercaptan-based curing agents are known as curing agents in order to quickly cure epoxy resins at low temperatures and provide cured products with high flexibility. has a bad odor, and the water resistance and chemical resistance of the resulting cured product are significantly inferior to those of modified amine-based curing agents.

Furthermore, a method using a condensate of phenols and diaminochlorohexane or an amine mixture containing the same and aldehydes as a curing agent (Japanese Patent Laid-Open No. 55-27364
) is also known, and can be cured quickly at low temperatures to obtain a cured product with high flexibility. However, when used for painted flooring, the surface of the coating may suffer from wear and scratches caused by walking. Therefore, it is easily damaged and has insufficient cosmetic properties and durability.

Furthermore, a method has been used in which an epoxy resin is modified with an alkanolamine or the like to contain a hydroxyl group in the molecule, and a urethane resin containing an active isocyanate group is used as a crosslinking agent.

However, in this case, the amount of coating per application is 0.5 m.
If the thickness exceeds 1.0 m, bubbles are likely to occur in the coating film, so in order to obtain a coating thickness of 1.0 m or more as a flooring material, it is necessary to repeat the coating several times. becomes difficult.

Means for Solving the Two Problems] In order to solve these problems, the present inventors have made various studies and found that the above problems can be solved by using bicycloheptane diaminomethyl as a curing agent for epoxy resin. We have found a way to solve this problem and have arrived at the present invention.

That is, the present invention provides a curing agent for epoxy resins whose active ingredient is a modified amine condensate obtained by condensing phenols, bicycloheptane diaminomethyl, and aldehydes as main components, and coating compositions and flooring materials containing the same. Regarding.

When the curing agent of the present invention is used in combination with an epoxy resin for paints, especially flooring materials that can be cured at room temperature,
As a matter of fact, it is possible to obtain a composition that cures in a short time even at a low temperature of 0 to 5°C and is resistant to scratches and abrasion on the coating surface.

The 2'L pinoclohebutane diaminomethyl used in the present invention includes, for example, 2,5-endo, exo-bicycloheptanediaminomethyl, 2,6-endo, exo-bicycloheptanediaminomethyl, 2.5-die Mention may be made of xo-bicycloheptane diaminomethyl, 26-diexo-bicycloheptane diaminomethyl, trimethyl and mixtures thereof.

The phenols used in the present invention include, for example, phenol, alkyl groups (methyl, butyl, octyl, nonyl, etc.), aryl groups (phenyl group, etc.), aralkyl groups (benzyl, cumyl group, etc.), halogen groups (chlorine, cumyl, etc.), Examples include substituted phenols substituted with at least one substituent such as bromine atom, etc.).

The phenols may be used as a mixture of two or more of the above compounds. Furthermore, not only -hydric phenols but also polyhydric phenols (resol, catechol, hydroquinone, bisphenol, etc.) can be used.

Among the above phenols, preferred are phenol, alkylphenol (especially ortho-, meta- and para-cresol, octylphenol, nonylphenol).

Examples of the aldehydes used in the present invention include formaldehyde, paraformaldehyde, acetaldehyde, paraldehyde, propionaldehyde, and chloral.

Preferred among these are formaldehyde, paraformaldehyde and acetaldehyde, with formaldehyde being particularly preferred.

Formaldehyde can be used as an aqueous solution or in solution in an organic solvent such as methanol, and this method of use is preferred.

The curing agent of the present invention contains as an active ingredient a condensation product of phenols (A), pinocloheptane diaminomethyl (B), and aldehydes (C). In this case, the molar ratio of A), (B) and (C) is usually (A): (B): (C) = 1:Q, 3-3
-0.3-3, preferably 1:1-3:1-3.

In the above molar ratio, the amount of the aldehyde (C) is sufficient as long as it can bind the piclohebutanediamine methyl (B) and the phenol (A), and the molar ratio of (C) is determined by the amount of the aldehyde (C) used (B). ) or (A) in excess of the molar ratio.

If the amount of (B) is less than 0.3 mol, the viscosity of the condensation product will be very high and the cured epoxy resin will become hard.
This would defeat the purpose of the invention.

If the amount of (B) exceeds 3 moles, the curing rate of the epoxy resin at room temperature and low temperature decreases significantly, and it is not sufficient as a curing agent.

Although the modified amine condensate can be obtained by a one-step reaction operation using all components of bicycloheptane diaminomethyl, it is preferable to obtain it by a two-step reaction operation.

That is, a mixture of phenols and bicycloheptane diaminomethyl is reacted with a carbonyl compound, or phenols and a carbonyl compound are reacted in advance,
A modified amine condensate is obtained by reacting this reaction product with pinoclohebutane diaminomethyl, or by reacting piclohebutanediaminemethyl with a carbonyl compound in advance and reacting this reaction product with a phenol.

At this time, the reaction temperature is 10 to 150°C, preferably 30 to 100°C.

Moreover, in order to complete the reaction, the temperature may be raised after the entire amount is added. After the reaction is completed, the reaction mixture is heated under reduced pressure to remove water and unreacted substances.

Usually, it is preferable that the modified amine condensate is liquid,
If the viscosity of the modified amine condensate is high, the viscosity can be lowered by using alcohols such as benzyl alcohol, nonyl alcohol, cyclohexanol, or plasticizers such as dibutyl phthalate or dibutyl adipate, if necessary. .

If the ratio of these diluents to the modified amine is too large, the physical properties of the cured product may deteriorate.
The ratio is usually 100:1 to 50, preferably 100:5 to 30.

The epoxy resin for curing the curing agent according to the present invention may be any ordinary epoxy resin, such as those described in "Chemistry of Synthetic Resins" (
1975 edition) Written by Tadahiro Miwa, published by Gihodo, No. 371~
Epoxy resins described on page 392 can be used.

Specifically, examples include glycidyl-type epoxy resins (bisphenol-based, polyglycol-based, ester-based, etc.) and non-glycidyl-type epoxy resins (alicyclic-based, etc.). Among them, bisphenol-based epoxy resins are preferred.

The blending ratio of the curing agent of the present invention to the epoxy resin is from 0.5 to 1 epoxy equivalent of the epoxy resin.
A proportion of 1,5 amino active hydrogen equivalents is suitable.

The curing agent of the present invention may be used in combination with other known curing agents if necessary, and in that case, the content of the curing agent of the present invention is usually 20% by weight or more of the total curing agent. be.

Examples of other known curing agents include those obtained by adding a diepoxo compound, acrylonitrile, etc. to polyamide amines and poly-J amines.

Curing agent for epoxy resin according to the present invention? When used as a flooring material, it has functions such as dustproofing, cosmetics, and waterproofing, but pigments and additives may be added as necessary to further enhance these functions and improve durability. It's okay.

Examples of such pigments include extender pigments such as silica powder, calcium carbonate, talc, mica, and clay, and colored pigments such as titanium oxide, Bengara, and Gohard Blue. 10-200 per 100 parts by weight
It is best to use about parts by weight.

Examples of additives include Norica powder such as Aerosil, and linking agents such as Modaflow and Nolcone.
5 to 5 double-view parts are preferred.

Curing agent of the present invention: In winter, for example, even at a low temperature of O to 5'C, it quickly cures the epoxy resin, L
It also has good physical properties, especially when used as a coated flooring material.It has appropriate toughness and hardness, so it feels good when walking on it, and it is a durable coated flooring material that is resistant to scratches on the surface. is obtained.

The curing agent of the present invention is important as a curing agent for paints and epoxy resins for civil engineering and construction when used with epoxy resins, but it can also be used for applications such as adhesives, casting resins, and laminates.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the invention is not limited thereto.

In the following, parts are by weight unless otherwise specified. The test results of Examples and Comparative Examples are summarized in the table.

Furthermore, the outline of the evaluation tests for each performance in Examples and Comparative Examples was as follows.

It was applied to a thickness of 0.1 mm on a glass plate with a length of 30 cm and a width of 2.5 cm, and its surface hardening properties were observed using a dry line recorder at environmental temperatures of 25°C and 0°C. .

Nori Mataki: Thickness 0.3mm, dimensions 50mm x 150mm
The coating was applied with a brush to a coating thickness of 1 mm on a sub-blasted steel plate, and the gloss, unevenness, and turbidity of the coating film after curing were evaluated.

JISK7215 using the above test specimen
The surface hardness was examined using a Shore hardness tester in accordance with ``Plastic durometer hardness test method''.

The surface of the coating film of the above test specimen was scratched with a 10 yen coin to judge the degree of scratching.

Impact resistance: Using a DuPont impact tester, a falling weight of 500 g with a radius of impact of 174 inches was dropped onto the above test specimen from a height of 50 cm to examine its impact resistance.

A hole with a diameter of 1 cm was made in the center of the test specimen, which was coated with a 1 mm thick brush on a slate board with a thickness of 0.8 cm and dimensions of 10 cm x 10 cm, and cured at room temperature for 1 week. The abrasion resistance of the surface of the test specimen was determined by rotating it 500 times under a load of 500g using the abrasion test device (wear wheel C5-17) described in JISAI453 r "Abrasion test method for building materials and building components". The amount of 'IIM was investigated.

The smaller the weight value, the better the wear resistance. It is.

The water absorption rate of the E-shaped objects was measured after being immersed in tap water for about a day.

Example 1 In a four-loop flask equipped with a stirrer, a thermometer, a fractionator with a condenser, and a nitrogen inlet tube, 2 moles (188 g) of phenol, 1 mole (154 g) of 2,5-endo,
Exo-vincloheptane diaminomethyl and 1 mol (
154 g) of 2.6=ene 1' and exo-vinclohedium were charged with butane diaminomethyl, '/H at 50°C,
Phenol to bicycloheptanediaminomethyl? After it was dissolved, 2.2 moles (162.2 g) of 37
% formalin was gradually added dropwise at a temperature below 50°C, and after the addition, the mixture was allowed to react at a temperature of around 50°C for 2 hours, and then raised to 80°C and stirred for 1 hour. The reaction was completed.

After the reaction was completed, dehydration distillation was performed under reduced pressure to obtain 520 g of a modified amine condensate.

156 g of dibutyl phthalate was added to this modified amine condensate.
The viscosity and amine value (KOH amount (mg) per 1 g of sample, converted to 4 m) of the curing agent at 25°C were measured.

In addition, by mixing the epoxy resin and the curing agent, it is possible to improve the openness when dry to the touch, the coating state of the cured product, the surface hardness, the scratch resistance, etc.
Impact resistance, abrasion resistance, and water resistance were investigated and listed in the table.

The epoxy resin used was Epicoat 828 manufactured by Yuka Noel Epoxy.

Example 2 As amines, 1 mol (154 g) of 2,5-endo, exo-vinclohebutanediaminomethyl and 2,5
- 1 mol (154 g) of diexobicyclohebutane diaminomethyl, 2 nonylphenols as phenols
A curing agent was prepared in exactly the same manner as in Example 1, except that mol (440 g) was used, and its performance was evaluated.

Example 3 1 mole (94 g) of phenol and 0.5 mole (40°55 g) of 37% formalin were placed in a four-loaf flask equipped with a stirrer, a thermometer, a fractionator with a condenser, and a nitrogen inlet tube. To this, 2.8 g of triethylamine was added as a catalyst, and the temperature was raised to 100°C while stirring. After raising the temperature, the reflux reaction was carried out for 2 hours while maintaining this temperature, and then 1.5 moles (231 g) of 2.5-
endo, exo-bicycloheptane diaminomethyl 1
After dropping the mixture over a period of time, the mixture was further stirred for 1 hour to complete the reaction.

After the reaction was completed, dehydration distillation was carried out under reduced pressure to obtain 330 g of a modified amine condensate, and 100 g of furfuryl alcohol was added thereto to uniformly dissolve it, which was used as a curing agent.

The performance of the curing agent was investigated in the same manner as in Example 1.

Example 4 As amines, 0.5 mol (77 g) of 2.5-endo, exo-bicycloheptane diaminomethyl, 25-
The procedure was carried out except that 0.5 mol (77 g) of diexobicycloheptane diaminomethyl and 0.5 mol (77 g) of 2,6-endo and exobicycloheptane diaminomethyl were used. A curing agent was prepared in exactly the same manner as in Example 3, and its performance was evaluated.

Comparative Example 1 1 mole (146 g) of triethylenetetramine was charged into a four-bottle flask equipped with a stirrer, a thermometer, a fractionator with a condenser, and a nitrogen inlet tube, and the mixture was heated at 100°C.
．． 0 mol (260 g) of butyl glycidyl ether was gradually added dropwise, and after the addition, the reaction was further carried out at a temperature of about 100° C. for 2 hours to complete the reaction.

After the reaction is complete, add 20 parts of phenol and 1 part of Hensyl alcohol.
Example 1
The performance of the curing agent was investigated in the same manner.

Comparative Example 2 100 parts of Tomide #235-3 (amine value: 340, manufactured by Fuji Kasei Kogyo) was uniformly dissolved and mixed with 20 parts of m-Fresol as a hardening agent, and the performance of the hardening agent was evaluated in the same manner as in Example 1. I looked into it.

Comparative Example 3 As amines, 1,3-diaminonoclohexane was
A curing agent was prepared in exactly the same manner as in Example 1, except that 2 moles (440 g) of nonylphenol was used as the phenol, and its performance was evaluated.

Comparative Example 4 Tris(methylaminomethyl) was added to 100 parts of Thiokol LP-3 (molecular weight approximately 1000; manufactured by Toshi Thiokol Co., Ltd.).
Phenol (DMP-30; manufactured by Kuchimu & Haas Co., Ltd.) 1
Example 1
The performance of the curing agent was investigated in the same manner.

Comparative Example 5 2 moles (760 g) of epoxy resin (Epicote 828; 190 g/equivalent, manufactured by Yuka NEL Epoxy) were placed in a four-bottle flask equipped with a stirrer, a thermometer, a fractionator with a condenser, and a nitrogen inlet tube. ) and 3 moles (312 g) of 2, opentyl glycol, as a catalyst, lithium hydroxide 0.
5 g was charged and reacted for 4 hours at a temperature of +80'C5 to complete the reaction. After the reaction is complete, 1072 ml of toluene is added.
g added as the main material of epoxy resin, Orestar P
49-', 5S (MJ methylolpropane toluene diisonore non-adduct active isonore 2, -t content 1
The reactivity and performance of the cured product were compared with Example 1 and No.
De = tone - ~ ta.

Table 1 shows the blending ratios of the above Examples and Comparative Examples, and Table 222 shows the evaluation results.

〔Effect of the invention〕

It is clear from Table 2 that the curing agent of the present invention can quickly cure the epoxy resin even at low temperatures of 0 to 5''C in winter, and can provide good physical properties.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. A curing agent for epoxy resins containing a modified amine condensate obtained by condensing phenols (A), bicycloheptane diaminomethyl (B) and aldehydes (C) as main components. 2. The condensation ratio of phenols (A), bicycloheptane diaminomethyl (B) and aldehydes (C) is (A):(B):(C)=1:0.3-3: 0.3~3
A curing agent for epoxy resin containing a modified amine condensate. 3. A coating composition comprising the curing agent for epoxy resin according to claim 1 and an epoxy resin. 4. A flooring material obtained by applying the coating composition according to claim 3.