JPH0148928B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a urethane-modified epoxy resin curable composition having novel internal flexibility. Conventionally, side-chain type epoxy resins, fatty acids, polymerized fatty acid-modified epoxy resins, long-chain alkylphenol-modified epoxy resins, internally plasticized epoxy resins, etc. have been developed and commercially available in order to impart flexibility to epoxy resins. Each has advantages and disadvantages in terms of performance, and no one has emerged that necessarily satisfies all characteristics. For example, side-chain type epoxy resins generally have slow curing speeds and insufficient water resistance and thermal shock resistance, and glycidyl ester-based polymerizable fatty acids generally have difficulty in alkali resistance, and are often used in materials such as concrete, mortar, and cement. Its use in civil engineering and construction applications where it is immersed in alkaline water is quite limited.
Furthermore, even when other flexibility imparting agents currently on the market satisfy the performance requirements, they are all in need of improvement, as their workability is significantly inferior. However, the present invention provides a urethane-modified epoxy resin curable composition which has a novel internal flexibility that improves the performance of the composition as a flexibility-imparting agent and has excellent workability. The curable composition of the present invention contains, as essential components, an epoxy compound (A) containing on average more than one epoxy group per molecule, a polyether polyol, a polyester polyol, a polyester polyether polyol, and castor oil. and at least one compound (B) selected from the group consisting of alkylene oxide adducts of castor oil in a proportion in which epoxy groups remain. Epoxy group-containing resin (A) obtained by reacting ) with a proportion in which no isocyanate groups remain, or a hydroxyl group-containing compound () obtained by reacting compound (B) with an isocyanate group and a compound (C) containing an isocyanate group in a proportion in which hydroxyl groups remain. An epoxy group-containing resin (2) obtained by reacting an epoxy compound (A) with a proportion of epoxy groups remaining.
(If desired, an isocyanate group-containing compound (C)
) and a curing agent for epoxy resin.
It contains (c). The epoxy compound (A) having more than one epoxy group in an average molecule used to obtain the composition of the present invention is not particularly limited, but for example, polyglycidyl ether of polyphenol, polyglycidyl ether of bisphenol A, etc. Glycidyl ethers, epoxy novolaks, polyglycidyl ethers of polyhydric alcohols, polyglycidyl esters of polycarboxylic acids, etc. can be used, preferably those having a molecular weight of about 300 to 2000 and an epoxy equivalent of about 150 to 1000. As the component (B) used to obtain the composition of the present invention, for example, the following can be used. Polyester (polyether) polyol: Molecular weight generally 100-5000 preferably 500-3000
As the diol component, for example, alkylene glycol such as ethylene glycol, propylene glycol, butylene glycol, or neopentyl glycol, cyclohexanedimethanol, or polyether polyol can be used, and as the dicarboxylic acid component, a dicarboxylic acid having 2 to 18 carbon atoms can be used. Carboxylic acids and their anhydrides such as phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, glutaric acid, chlorendonic acid, tetrachlorophthalic acid or Any of these anhydrides can be used. Lactones such as caprolactone may also be included in the polyester components. Polyether polyol; molecular weight generally 500
The active hydrogen content of the above-mentioned alkylene glycols, amines, carboxylic acids, etc. is preferably about 3000.
It is possible to use a compound obtained by adding ethylene oxide, propylene oxide, tetrahydrofuran, etc. to a compound having at least one of these. Castor oils: Castor oil and its alkylene oxide adducts. The isocyanate group-containing compound (C) used in the present invention includes toluene diisocyanate, 4,
4'-diphenylmethane diisocyanate, 4,
4'-biscyclohexylmethane diisocyanate, crude MDI, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, or a terminal isocyanate group-containing prepolymer obtained from these and an active hydrogen compound can be used. Reaction between epoxy group and hydroxyl group, i.e. (A) and (B) above
Or when reacting (A) with (), tertiary amine etc.
It is sufficient to use 0.2 to 1.0% by weight as a catalyst and react at 100 to 200°C, preferably 120 to 180°C for several hours. Through this reaction, the epoxy group reacts with the hydroxyl group, and further a polymerization reaction between the epoxy groups occurs partially. As a result, a compound containing an ether bond and a secondary hydroxyl group is obtained. Catalysts include benzyldimethylamine, dimethylcyclohexylamine, dimethylethanolamine, triethylamine, tributylamine, trimethylamine, etc., as well as BF ₃ complexes (BF ₃ -monomethylamine, BF ₃ -benzylamine, BF ₃ -piperazine, BF ₃ -aniline). , BF ₃ -methylaniline, etc.), aluminum isopropoxide, etc. can also be used. The reaction between isocyanate groups and hydroxyl groups, that is, the reaction between (C) and () or (C) and (B), may be carried out at 60 to 150°C, preferably 70 to 120°C, for several hours. The curing agent (c) for epoxy resins used in the composition of the present invention may be those commonly used, such as ethylenediamine, diethylenetriamine,
Aliphatic amines such as triethylenetetramine, pentaethylenetetramine, hexamethylenepentamine, m-xylylenediamine, alicyclic amines such as 4,4'-diaminobiscyclohexylmethane, isophoronediamine, hydrogenated xylylenediamine,
Polyamides, amido-amines, amine adducts, aromatic amines such as diaminodiphenylmethane and metaphenylenediamine, aniline-formalin resins, modified aromatic amines, or phthalic anhydride, hexahydrophthalic acid, tetrahydro- Carboxylic acids such as phthalic acid and their anhydrides, the aforementioned BF ₃ complex compounds, dicyandiamide, imidazoles, etc. can be used. The feature of the present invention is that flexibility is imparted between the epoxy resin molecules and urethanization is imparted.The flexibility imparted within the epoxy molecules increases the compatibility with ordinary epoxy resins and does not significantly slow down the curing speed. Flexibility can be imparted, and since the crosslinking rate is also improved, the water resistance of the cured product is also good. On the other hand, the urethanization of the present invention improves adhesion to the base material, and the use of polyester polyols and castor oil as the internal flexibility imparting agent of the present invention reduces alkali resistance and water resistance.
Urethane conversion can be said to be extremely important in terms of improving this point. Further features of the present invention include high impact strength, excellent resistance to temperature changes, and good flexibility at low temperatures. Although the internally flexible urethane-modified epoxy resin of the present invention can be used alone as a resin component,
It may be used in combination with other conventionally known epoxy resins. In addition, the composition of the present invention may also contain other inorganic fillers (calcium carbonate, silica, titanium dioxide, carbon, alumina, talc, clay, etc.) or solvents (toluene, xylene, alcohols) and plasticizers (DBP,
It can also contain phthalate esters such as DOP, furfuryl alcohol, benzyl alcohol, coal tar). In addition, as a curing accelerator, phenol, cresol, nonylphenol, styrenated phenol,
Phenols such as resorcinol, xylenol, and salicylic acid, tertiary amines such as DMP-10 and DMP-30, and aminophenols such as trisdimethylaminomethylphenol can also be blended. Hereinafter, the present invention will be explained in further detail with reference to Examples.
Note that parts in the examples are based on weight. Example 1 200 g of castor oil, 250 g of bisphenol-type epoxy resin (Adeka Resin EP4100 (manufactured by Asahi Denka) with an epoxy equivalent of 191 and a viscosity (25°C) of 100 PS), and 1.5 g of BF ₃ -monoethylamine complex salt as a polymerization addition catalyst.
was added and reacted for 3 hours at 130 to 140°C in a N ₂ gas stream. After the reaction, 4g of activated clay was added to remove the catalyst activity, and the epoxy equivalent was filtered at 100℃.
503, a reaction product () with a viscosity (25°C) of 280 PS was obtained. Furthermore, take 300 g of the obtained reaction product (), add 15 g of TDI, and heat at 90-100 °C in a _N2 stream.
A urethane-forming reaction was carried out for 3 hours to obtain a urethane-modified epoxy resin (A) having internal flexibility. Curable compositions having the compositions shown in Table 1 were prepared and their physical properties were evaluated. The results are shown in Table 1.

[Table] Example 2 250 g of Adekalezin EP-4100, 200 g of polyoxypropylene glycol (molecular weight 400, P-400 (manufactured by Asahi Denka)), and 1.5 g of benzyldimethylamine as a catalyst were added, and the mixture was heated at 140°C in a N ₂ stream. The reaction was carried out for 2 hours. After the reaction, a reaction product (2) was obtained which was endowed with internal flexibility using polyoxypropylene glycol (epoxy equivalent: 406). Furthermore, take 200g of the above reaction product (), add 10g of MDI,
The reaction was carried out at ℃ for about 3 hours in a N ₂ stream to obtain a urethane-modified epoxy resin (B) imparted with internal flexibility using polyoxypropylene glycol. A curable composition having the composition shown in Table 2 was prepared, and its physical properties after curing at room temperature for 7 days were evaluated. The results are shown in Table 2.

[Table] Example 3 1000 g of castor oil, 400 g of polyether polyol with a molecular weight of 400 (P-400 manufactured by Asahi Denka), 174 g of TDI
was added, and the reaction was carried out at 90 to 100°C for 3 hours in a N ₂ stream to obtain a urethane prepolymer having terminal hydroxyl groups. Urethane prepolymer having the above terminal hydroxyl group
Add 250 g of Adekalezin EP-4100, 20 g of diglycidyl ether of hexanediol, and 1.5 g of BF ₃ monoethylamine to 200 g, and heat at 140 °C in a stream _{of N2} .
A time reaction was carried out to obtain a urethane-modified epoxy resin (C) having an epoxy equivalent of 430 and having a urethane bond in the molecule and imparting internal flexibility. Curable compositions having the compositions shown in Table 3 were prepared, and the physical properties after curing for 7 days at room temperature were evaluated. The results are shown in Table 3.

【table】

[Table] Example 4 200 g of Adeka Resin EP-4100, 300 g of polyester polyol [Adekanyu Ace F-7-67 (hydroxyl value 55-59, viscosity (25°C) 12000 cPS, manufactured by Asahi Denka)], aluminum isopropoxy as a polymerization catalyst Add 12g of side catalyst 20% benzene solution,
The reaction was carried out at 180° C. for 3 hours in a N ₂ stream. After completion of the reaction, an internally flexible reaction product (2) was obtained which was a viscous liquid at room temperature and had an epoxy equivalent of 705. Furthermore, 300 g of the above-obtained reaction product () was taken and reacted with isophorone diisocyanate and Adecanyu Ace F-7-67 in a _N2 stream by a known method to obtain a terminal isocyanate precipitate with an NCO content of 4.2%. Add 50g of polymer and heat at 90℃ for 4 hours.
The reaction was carried out in a N ₂ stream for a period of time to obtain a urethane-modified epoxy resin (D) having internal flexibility. Curable compositions having the compositions shown in Table 4 were prepared, and their physical properties after curing at room temperature for 7 days were evaluated. The results are shown in Table 4.

[Comparative example]

60g of polypropylene glycol (Asahi Denka P-2000) with an average molecular weight of 2000 and 21g of TDI at 85%
The polyurethane prepolymer was reacted for 3 hours at °C.
Obtained 81g. 81g of this polyurethane prepolymer
, 2,2-bis-(4-hydroxyphenyl)
Propane diglycidyl ether (epoxy equivalent)
190, OH value 14) Add to 500g and react for 1 hour. The obtained urethane-modified epoxy resin (F) had an epoxy equivalent of 230. Curable compositions having the compositions shown in Table 5 were prepared, and the physical properties after curing for 7 days at room temperature were evaluated. The results are shown in Table 5. In Table 5, it can be seen that Comparative Example Composition 13 has very little internal flexibility, as shown by data such as hardness, tensile strength, elongation, and impact resistance.

【table】

Claims (1)

[Claims] 1 Selected from the group consisting of an epoxy compound (A) having an average of more than one epoxy group in one molecule, polyether polyol, polyester polyol, polyester polyether polyol, castor oil, and alkylene oxide adducts of castor oil An isocyanate group-containing compound (C) is reacted with a compound containing an epoxy group and a hydroxyl group () obtained by reacting at least one compound (B) in a proportion in which epoxy groups remain. an epoxy group-containing resin obtained by
A urethane-modified epoxy resin curable composition having internal flexibility, characterized by containing a curing agent for epoxy resin.