JPH0859960A - Epoxy resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject composition useful as a cured material, having low viscosity, excellent workability, flexibility and adhesiveness, comprising an aromatic epoxy resin, a urethane-modified epoxy resin of specific composition and an aliphatic or alicyclic epoxy resin. CONSTITUTION: This resin composition comprises (A) an aromatic epoxy resin composed of (i) a bisphenol A type diglycidyl ether, (ii) a bisphenol F type glycidyl ether or (iii) a mixture of both the components, (B) a urethane-modified epoxy resin obtained by reacting (iv) a hydroxyl group-containing aliphatic or alicyclic epoxy compound with (V) an isocyanate prepolymer consisting of a polyether diol or polyester diol and a polyisocyanate and (C) an aliphatic or alicyclic epoxy resin. The blending ratio of the component A/B/C is preferably (95-10)/(0.25-63)/(4.75-27).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition capable of retaining high workability due to the low viscosity of a compound in the field of paints, civil engineering and adhesion.

[0002]

2. Description of the Related Art Generally, since structures, facilities on land, ocean and harbor are exposed to severe corrosive environment, initial corrosion prevention and maintenance are important issues. In such environments and applications, epoxy resin-based paints and adhesive, pouring, and sealing compounds are often used to protect the concrete and steel materials that are the base materials. Such paints and compounds are required to have anticorrosion properties as well as flexibility and adhesive properties capable of following environmental temperature changes.

Conventionally, in order to exhibit the above-mentioned flexibility and the like, a so-called rubber or acid-modified epoxy resin of bisphenol A type or bisphenol F type is modified with a rubber having a carboxyl group or a monomer acid or a dimer acid. Epoxy resins, bisphenol A type or bisphenol F type epoxy resins modified with urethane prepolymers, so-called urethane-modified aromatic epoxy resins, and the like have been used.

[0004]

However, with these modified epoxy resins, the viscosity of the resin increases significantly as a result of modification, and this limits the design of paints and blends, and sacrifices performance. The current situation is to use diluents and solvents. The acid-modified epoxy resin has a problem in anticorrosion because an ester bond is further generated in the resin skeleton.

The present invention provides an epoxy resin having a low viscosity which improves workability, and flexibility, adhesiveness capable of following environmental changes, and corrosion resistance capable of withstanding severe environments.

[0006]

The present invention provides (A) an aromatic epoxy resin, (B) a hydroxyl group-containing aliphatic epoxy compound or alicyclic epoxy compound (b1), and a polyether diol or a polyester diol. An epoxy resin composition containing a urethane-modified epoxy resin obtained by reacting an isocyanate prepolymer (b2) obtained from a polyisocyanate, and (C) an aliphatic epoxy resin or an alicyclic epoxy resin. Regarding

The aromatic epoxy resin (A) used in the present invention is an aromatic epoxy resin having two or more epoxy groups obtained by epoxidizing a compound having two or more hydroxyl groups in the aromatic ring, for example, bisphenol A. Type diglycidyl ether, bisphenol F type diglycidyl ether, bilphenol S type polyglycidyl ether, mixture of bisphenol A type diglycidyl ether and bisphenol F type diglycidyl ether, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A Examples thereof include novolac type epoxy resins such as novolac type epoxy resins, and aromatic epoxy resins having two epoxy groups are particularly preferable.

The aliphatic epoxy compound (b1) having a hydroxyl group is preferably a compound obtained by reacting an aliphatic polyol with epichlorhydrin and then hydrolyzing the resulting compound, each having a hydroxyl group and a glycidyl group at the terminal. is there. As such an epoxy compound, one having at least one hydroxyl group and at least one glycidyl group at the terminal is used. The epoxy equivalent of such a compound is preferably 80 to 500 g / eq, more preferably 12
It is 0 to 400 g / eq.

As the above-mentioned aliphatic polyol, those having two or more hydroxyl groups, having 2 to 4 hydroxyl groups and having 2 to 12 carbon atoms, particularly 3 to 8 carbon atoms are preferable. For example, ethylene glycol, 1,2-propanediol, 1,
3-propanediol, 1,3-butanediol, 1,
4-butanediol, neopentyl glycol, 1,6
-Hexyl glycol, 2-ethylhexyl glycol, 1,10-decanediol, glycerin, trimethylolpropane, tetrapropanol pentane and the like.

As the alicyclic epoxy compound (b1) containing a hydroxyl group, cyclohexyldiol, a compound obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to the hydroxyl group of cyclohexyldiol, and epichlorohydrin are reacted and hydrolyzed. It is preferable that the resulting polymer has at least one hydroxyl group and at least one glycidyl group in the molecule. The epoxy equivalent of such a monoepoxy compound is preferably 100 to 1000 g.
/ Eq, more preferably 120 to 500 g / eq.

The isocyanate prepolymer (b2) is
It has two isocyanate groups, which is obtained by reacting a polyether diol or polyester diol with a polyisocyanate so that the isocyanate groups are in excess with respect to the hydroxyl groups.

Examples of the polyether diol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polybutylene glycol and polyethylene-propylene glycol. Such a polyether diol preferably has a number average molecular weight of 4
It is 0 to 5000, and more preferably 200 to 3000.

As the polyester diol, ethylene glycol, propylene glycol, butane diol,
With diols such as heptanediol, neopentyl glycol, hexanediol, cyclohexanediol,
Dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, phthalic acid, terephthalic acid, hexahydrophthalic acid, and hexahydroterephthalic acid, or their alkyl esters or acid halides or anhydrides, and an excess amount of hydroxyl groups with respect to the acid groups. It is obtained by reacting so that
Such polyester diol preferably has a number average molecular weight of 150 to 5,000, more preferably 200 to 300.
0.

As the polyisocyanate, hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, xylene diisocyanate,
Cyclohexane diisocyanate, toluidine diisocyanate, 2,4-tolylene diisocyanate, 2,6
-Tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 1,5-naphthylene diisocyanate and the like, and mixtures thereof, particularly xylene diisocyanate and 2,4-tolylene diisocyanate. 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate and 2,6-
A mixture of tolylene diisocyanates, 4,4'-diphenylmethane diisocyanate, is preferred.

The aliphatic epoxy resin (C) is an aliphatic epoxy resin having one or more epoxy groups, preferably two epoxy groups. For example, it is obtained by reacting alkylene diol with epichlorhydrin and hydrolyzing them. And having one or two epoxy groups at the end. Such an epoxy resin may be produced simultaneously with the production of the hydroxyl group-containing aliphatic epoxy compound, or may be produced separately from the hydroxyl group-containing aliphatic epoxy compound, but the hydroxyl group-containing aliphatic epoxy compound is produced. It is preferable to manufacture them at the same time. The epoxy equivalent of such an epoxy resin is preferably 80 to 500 g / eq, more preferably 120 to 400 g / eq.

As the alkylene diol as the raw material of the aliphatic epoxy resin, the same alkylene diol as the raw material of the hydroxyl group-containing aliphatic epoxy resin is used.
As the alicyclic epoxy compound (C), cyclohexyl diol, a compound obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to a hydroxyl group of cyclohexyl diol, and epichlorhydrin are reacted with each other, and obtained by hydrolysis. It has a hydroxyl group and a glycidyl group, respectively. Such monoepoxy compound preferably has an epoxy equivalent of 150 to 500.
0 g / eq, more preferably 200 to 3000 g / eq
Is.

The urethane-modified epoxy resin (B) comprises a hydroxyl group-containing aliphatic monoepoxy compound or a hydroxyl group-containing alicyclic monoepoxy compound (b1), an isocyanate prepolymer (b2), and a hydroxyl group and an isocyanate group. Although it has two epoxy groups obtained by reacting so as to be approximately equivalent, it may contain one having one epoxy group. The epoxy equivalent of the urethane-modified epoxy resin is preferably 350 to 1300 g /
eq, more preferably 500 to 1100 g / eq.

Regarding such urethane-modified resin, when the aliphatic epoxy compound having a hydroxyl group or the alicyclic epoxy compound (b1) having a hydroxyl group is reacted with the isocyanate prepolymer (b2), an aliphatic epoxy resin or It may be obtained by mixing the alicyclic epoxy resin (C) with an aliphatic epoxy compound having a hydroxyl group or an alicyclic epoxy compound having a hydroxyl group (b1) and reacting the mixture with an isocyanate prepolymer (b2).

In the present invention, in order to better achieve the effects of the present invention, the epoxy equivalent when the urethane-modified epoxy resin (B) and the aliphatic epoxy resin or the alicyclic epoxy resin (C) are combined is preferably 150-270g /
eq, more preferably 170 to 250 g / eq, both are preferably contained.

The weight ratio of the aromatic epoxy resin (A), the urethane-modified epoxy resin (B), and the aliphatic epoxy resin or alicyclic epoxy resin (C) in the composition of the present invention is (A) and (B). ) And (C) in total 100, (A) / (B) / (C) is preferably (95-10) /
(0.25 to 63) / (4.75 to 27), more preferably (90 to 50) / (2 to 25) / (8 to 25).

The blend ratio of the urethane-modified epoxy resin (B) and the aliphatic epoxy resin or the alicyclic epoxy resin (C) in the present invention is preferably (B) / (C) = on a weight basis. 50 / 950-700 / 300, more preferably (B) / (C) = 200 / 800-500 /
It is preferably set to 500.

The curing conditions of the epoxy resin composition of the present invention can be both room temperature curing and heat curing, and the cured product performance does not differ significantly depending on the curing conditions. When the composition of the present invention is cured at room temperature, a curing agent is used in combination, but an amine curing agent is preferably used.

Examples of the amine-based curing agent that can be used include polyalkylene polyamine, aminoethylpiperazine, metaxylene diamine, isophorone diamine, polyoxyalkylene diamine, and the like, and reaction products of these amines with monomer acids and dimer acids. Examples thereof include so-called polyamide / polyamidoamine, modified polyamine which is a reaction product with epoxy resin or phenol / formalin.

In the present invention, the compounding amount of the amine-based curing agent is an epoxy resin comprising an aromatic epoxy resin (A), a urethane-modified epoxy resin (B) and an aliphatic epoxy resin or an alicyclic epoxy resin (C). Equivalent ratio of composition / amine curing agent, preferably 1.0 / 0.5 to 1.0 /
1.5, more preferably 1.0 / 0.7 to 1.0 / 1.
The amount is 3.

If desired, reactive diluents, non-reactive diluents, solvents, pigments, additives, extenders and the like can be used in the composition of the present invention.

Since the composition of the present invention has a low viscosity, it has good workability, and has practically useful flexibility, adhesiveness, and
A cured product having corrosion resistance and durability can be provided.
Most suitable as an adhesive and anticorrosion paint for metal, plastic, concrete, etc.

Examples will be shown below.

[0028]

【Example】

[Synthesis Example 1] (Production of epoxy resin) 104 g of 2,2-dimethyl-1,3-propanediol (special grade reagent manufactured by Wako Pure Chemical Industries, Ltd.) in a 4-liter four-necked flask equipped with a slot under a nitrogen stream. The mixture was charged, the temperature of the mixture was started to be stirred, and 0.31 g of boron trifluoride ethyl ether salt was added in two portions at 60 ° C. Flask temperature is 65-
While cooling to 73 ° C, epichlorohydrin 2
13 g was dropped. After completion of dropping, the temperature was maintained at 70 ° C. for 1 hour. 295 g of 30% aqueous sodium hydroxide solution was added dropwise thereto and kept for 3 hours, after which 222 g of toluene and 14 parts of water were added.
7 g was added. Next, the stirring was stopped, the solution was allowed to stand still, and the lower layer was extracted.

The separated upper layer was stirred and heated to 80 ° C., and 3.
90 g of 5% sodium hydroxide aqueous solution, then 50% TE
0.13 g of an aqueous BCL solution was added, and the mixture was kept at 80 ° C. for 3 hours. After the stationary separation, the lower layer was extracted. The separated upper layer was stirred, 161 g of 0.1% sodium dihydrogen phosphate was added, and the mixture was kept at 80 ° C. for 3 hours. After the stationary separation, the lower layer was extracted. After returning to normal pressure and cooling to 100 ° C., the product was filtered and taken out.

The obtained epoxy resin X had an epoxy equivalent of 155 g / eq and a viscosity of 20 cps. The ratio of the hydroxyl group-containing molecule and the hydroxyl group-free molecule in this epoxy resin X was 56/44 (molar ratio).

[Synthesis Example 2] (Production Method of Urethane-Modified Epoxy Resin-Containing Resin) 630 g of the epoxy resin of Synthesis Example 1 was placed in a 1-liter four-necked flask and heated to 60 ° C. under a nitrogen stream. Here, the temperature rise is stopped and an isocyanate prepolymer obtained by reacting 2 mol of toluene diisocyanate with 1 mol of polytetramethylene glycol (a number average molecular weight of 140
0) 70 g was added dropwise over 30 minutes while paying attention to heat generation. After completion of the dropping, the mixture was heated at 80 ° C for 1 hour and 120 ° C for 2 hours to obtain an epoxy equivalent of 172g / eq and a viscosity of 800cp
A urethane-modified epoxy resin-containing resin (B-1) of s was obtained. This urethane-modified epoxy resin-containing resin (B-1)
Contained about 14.5% by weight of urethane-modified epoxy resin and about 85.5% by weight of non-urethanized aliphatic epoxy resin.

[Synthesis Example 3] (Same as above) 490 g of the epoxy resin of Synthesis Example 1 was placed in a 1-liter four-necked flask, and the temperature was raised to 60 ° C. under a nitrogen stream. Here, the temperature rise was stopped and the isocyanate prepolymer 21 of Synthesis Example 2
0 g was added dropwise over 90 minutes while paying attention to heat generation. After completion of the dropping, the mixture was heated at 80 ° C. for 1 hour and 120 ° C. for 2 hours to obtain a urethane-modified epoxy resin-containing resin (B-2) having an epoxy equivalent of 221 g / eq and a viscosity of 2200 cps. The urethane-modified epoxy resin-containing resin (B-2) contained about 43% by weight of the urethane-modified epoxy resin and about 57% by weight of the non-urethane-modified aliphatic epoxy resin.

[Synthesis Example 4] (Same as above) 455 g of the epoxy resin of Synthesis Example 1 was placed in a 1-liter four-necked flask and heated to 60 ° C. under a nitrogen stream. Here, the temperature rise was stopped and the isocyanate prepolymer 24 of Synthesis Example 2
5 g was added dropwise over 120 minutes while paying attention to heat generation. After dropping, heat at 80 ° C for 1 hour and 120 ° C for 2 hours,
Epoxy equivalent 238g / eq, viscosity 10000cps
The urethane-modified epoxy resin-containing resin (B-3) was obtained. This urethane-modified epoxy resin-containing resin (B-3)
Contained about 50.4% by weight of urethane-modified epoxy resin and about 49.6% by weight of non-urethanized aliphatic epoxy resin.

[Examples 1 to 11 and Comparative Examples 1 to 5] Each epoxy component was blended as shown in the table below, and a predetermined amount of talc and silica were added thereto to form a paint by a ball mill. Then, a curing agent component was added thereto as shown in each table, and brush coating was applied to a sandblast plate so that the dry film thickness was about 100 μm, followed by curing at room temperature for 1 week.

[Evaluation Method] Epoxy Equivalent: According to JIS K7236. Viscosity: A glass bottle with a lid for 800 g of a measurement sample was immersed in a constant temperature water bath controlled at 25 ° C for 2 hours, and then measured with a rotary viscometer.

Compatibility: A fixed amount of A component kept at 25 ° C. in a glass bottle with a lid for 200 g was taken and placed in a glass bottle for 3 days.
After stirring for a minute, the compatibility was visually confirmed.

Hardness: JI in the pencil scratch test
Conforms to SK5400 Impact: JIS K540 according to DuPont impact test
Compliant with 0

Cross-cut peeling: JIS K in the cross-cut test
Compliant with 5400 Approximately the center of the test piece is drawn with a cutter knife at a parallel line at an interval of 1 mm at intervals of 1 mm to make 100 square-shaped cuts in 1 cm ² . Stick 18mm wide on this square. After that, hold one end of the attached cellophane tape
Peel off the test piece at once. It is judged by the number of cells (x / 100) remaining on the test piece at that time.

Anticorrosion: Conforms to JIS K5400 (by salt spray) ◎: No abnormality, ○: Blisters are less than 5% of the coated surface, △: 5
20% x: 20% or more of blisters on the coated surface

Durability: Mortar pieces prepared according to JIS R5201 (longitudinal length 40 × 4)
3mm wide and 50m long with diamond cutter
m, deep carve. Pour the coating composition shown in each table into this groove, and
Cure for 7 days under conditions of 0 ± 2 ° C. and 90% humidity. So
Outdoor exposure to the post-injection surface and observation of changes in the injection-hardened part.

⊚: No abnormality ○: Peeling is less than 5% of the mortar adhesive surface Δ: Peeling is 5 to 20% of the mortar adhesive surface ×: Peeling is 20% or more of the mortar adhesive surface

[0042]

(*): Product of Yuka Shell Epoxy Co., Ltd. (*) Other than: Product of Dainippon Ink and Chemicals, Inc. Curing agent EPICLON B-5385: Active hydrogen equivalent 80 g / eq 〃 B-025: Active Hydrogen equivalent 115g / eq

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

Since the composition of the present invention has a low viscosity,
It is possible to provide a cured product having good workability and practically useful flexibility, adhesiveness, corrosion resistance, and durability.

Claims (7)

[Claims] 1. An aromatic epoxy resin (A), an aliphatic epoxy compound (B) having a hydroxyl group or an alicyclic epoxy compound (b1) having a hydroxyl group, and a polyether diol or polyester diol and polyisocyanate. Obtained isocyanate prepolymer (b2)
A urethane-modified epoxy resin obtained by reacting
(C) An epoxy resin composition comprising an aliphatic epoxy resin or an alicyclic epoxy resin. 2. The aromatic epoxy resin (A) is (A1) bisphenol A diglycidyl ether, (A2) bisphenol F diglycidyl ether, or (A3).
The resin composition according to claim 1, which is a mixture of both. 3. The resin composition according to claim 1, wherein the polyether diol is polyalkylene glycol. 4. The epoxy equivalent of the urethane-modified epoxy resin (B) and the aliphatic epoxy resin or the alicyclic epoxy resin (C) is 150 to 270 g / eq. The composition as described. 5. A compounding ratio of the aromatic epoxy resin (A), the urethane-modified epoxy resin (B) and the aliphatic epoxy resin or the alicyclic epoxy resin (C) is (A) on a weight basis.
/(B)/(C)=(95-10)/(0.25-6)
3) / (4.75-27), The resin composition according to claim 1. 6. An aliphatic epoxy in which a mixture of a urethane-modified epoxy resin (B) and an aliphatic epoxy resin or an alicyclic epoxy resin (C) has two or more epoxy groups and has no hydroxyl group. Resin or alicyclic epoxy resin (C) and a mixture of an aliphatic monoepoxy compound or an alicyclic monoepoxy compound (b1) containing a hydroxyl group with an isocyanate prepolymer (b2) in which the hydroxyl group is in excess of the isocyanate group. The composition according to claim 1 or 7, which is obtained by reacting so that 7. An aromatic epoxy resin (A), a urethane-modified epoxy resin (B), an aliphatic epoxy resin or an alicyclic epoxy resin (C), and an amine curing agent (D). A characteristic curable epoxy resin composition.