CS265381B1 - Adducts, in particular for the curing and modification of epoxy resins - Google Patents

Abstract

The solution falls into the field of synthetic resins and hardeners and can be used in a number of industries in the technological processing of products based on epoxy resins. The problem of preparing addition hardeners with low vapor pressure, low toxicity, excellent compatibility with known types of epoxy resins and very good mechanical properties of go curing is solved. The essence of the solution is an adduct prepared by reacting a mixture of aliphatic and heterocyclic polyamines with aliphatic, cyclanic or aromatic epoxy compounds in a molar ratio of polyamine : epoxide - 1 to 10 : 1. The adducts can be further modified by adding acrylic, maleic or fumaric acid esters, or the properties of the adduct can be adjusted by adding hardening accelerators, substances affecting flow and pouring parameters.

Description

The invention relates to adducts, in particular for curing and modifying epoxy resins having lower toxicity and improved performance properties.

Various types of amine hardeners are used for curing epoxy resins, depending on the desired processing parameters, the target properties of the cured mass and the economic parameters. Commonly used are polyamine adducts with low molecular weight epoxy compounds, in particular mono- and diglycidyl ethers of alcohols, phenols, glycidylamines, glycidylsulfides, and diolium-based ecian epoxy resins. Polyamine adducts with epoxy compounds obtained by epoxidation of unsaturated compounds such as propylene, styrene, cyclohexane, alphaolefins, drying oils and the like are also popular. Depending on the nature of the epoxide and polyamines used, the adducts have a number of favorable and unfavorable properties. Among the advantages are, in particular, a reduction in the vapor pressure, an improvement in the curing process, an increase in the shape stability under heat, an improvement in the resistance to water and certain chemicals, and the like. The main drawbacks are the still high vapor pressure, relatively high content of volatile polyamines, which usually have considerable toxicity, high viscosity, limited compatibility with a number of modified epoxy resins and not always satisfactory parameters after a longer period of time.

265 381 storage. These drawbacks are solved by various routes, in particular by selecting special epoxides, by using other modifiers or equalizers and the like. In general, finding a suitable type of modified hardener of the adduct type makes the problem very difficult and not always objectively solvable.

For many application areas, for example in the construction industry, the use of adducts would be advantageous, but it is often a defect in its higher cost, considerable vapor pressure and not entirely satisfactory rheological and surface properties. A similar situation is in the area of preparation of sealants, adhesives and laminating materials. Therefore, the manufacturers of epoxy materials are very intensively developing new improved hardeners, in particular based on epoxide adducts with polyamides, but the type of universally applicable and suitable adduct for curing epoxy resins has not yet been solved.

In developing new types of epoxy curing agents, we have found that adducts of very good properties having low vapor pressure and good compatibility with most known types of unmodified and modified epoxy resins can be prepared.

The adducts of the invention are obtainable from a mixture of polyamines containing 20 to 90 wt. % aliphatic polyamines of structure h ₂ n-ch ₂ ch ₂ -NHCEgCHg,

1-4

-NH, up to 80 wt. % of heterocyclic polyamines of structure h ₂ nch ₂ ch ₂ nh ·

--CH ₉ CH ₉ N

0-4 \

CH CH _O / 2

2x rn4CH ₂ CH ₂ NH <

ch ₂ oh ₂

0-4

-h with aliphatic, cyclanic or aromatic epoxy compounds having an average molecular weight of 44 to 600, in a polyamine: epoxide molar ratio = 1 to 10: 1.

Of the epoxy compounds, ethylene oxide, propylene oxide, cyclohexene oxide, epoxidated unsaturated terpenes,

265,381, for example limonene oxide, epoxidized alpha-olefins of 0 to 0

Gly ^ θ, glycidethers of aliphatic monoalcohols or polyols, aromatic glycidethers and low molecular weight epian resins based on diane with an average molecular weight of 340 to 600.

In well-founded cases, preferably mixtures of epoxides, technical fractions or distillation slices may also be used. Optionally, the properties of the adducts of the invention can be modified by the addition of acrylic, fumaric, maleic or cinnamic acid esters. If desired, adducts may also be treated by the addition of curing accelerators, rheological and surface conditioning agents, color and odor. Starting mixtures of polyamines can be prepared by simply mixing the components, by thermal or catalytic cyclization, or by alkylation with dichloroethane, or other known methods. The preparation process consists in dropping the epoxide into the present mixture of polyamines with stirring, the temperature of the reaction mixture usually being kept below 100 ° C. After completion of the epoxide feed, the reaction mixture is usually allowed to react for 15 to 60 minutes at 80 to 100 ° C.

The adducts of the invention are liquids having a viscosity of 150 to 150

Λ

150,000 mPa.s / 25 Oas of the most commonly known epoxy resins and modifications are unrestrictedly miscible. A notable advantage is the low vapor pressure, which does not exceed 10 Pa at room temperature, with little or no evolution of toxic vapors over large areas of application (poured floors). Due to the combined structure of the starting polyamines, the epoxy resins cured by the adducts of fir of the invention achieve very good mechanical parameters, the materials are highly tough and well resist aggressive waters and other chemical agents.

Example 1

Into a 500 ml three-necked Ke11er flask equipped with a stirrer, a 1.5 mole blend of polyamines of

10.5 g (0.102 mol) of diethylenetriamine,

32.9 g (0.225 mol) of triethylenetetramine,

265 381

77.0 g (0.407 mol) of tetraethylenepent amine,

127.8 g (0.55 mol) of pentaethylenehexamine,

27.9 g (0.216 mol) of N-aminoethylpiperazine and the mixture was heated to 50 ° C with stirring. While stirring, 114 g (1 mol) of allyl glycideter are added dropwise at such a rate that the reaction temperature does not exceed 80 ° C. After completion of the dropwise addition, the mixture was allowed to react for 30 minutes, 5 g of salicylic acid were added and after homogenization for 10 minutes, the product was cooled and discharged. The product is a liquid having a viscosity of 458 mPa · s / 25 ° C having an amine number of 1025 mg KOH / g and an equivalent weight of 39.91 ·

Example 2

129 g (1 mol) of N-aminoethylpiperazine and 275 g (1 mol) of hexaethyleneheptamine are introduced into the apparatus described in Example 1. At 30-35 ° C, 88 g (2 moles) of ethylene oxide gas are allowed to flow to the bottom of the flask with stirring and cooling at a rate of 50 ml / minute. After completion of the ethylene oxide feed, the reaction mixture was heated to 90 ° C and allowed to react for 15 minutes. The product is a liquid having a viscosity of 607 mPa · s / 25 ° C, an amine number of 1138 mg KOH / g and an equivalent weight of 49.20.

Example 3

Into a 2000 ml flask equipped with a stirrer, a reflux condenser and a thermometer, add 5 moles of a polyamine composition

475 g (2.5 mol) of tetraethylenepentamine

232 g (1 mol) of pentaethylenehexamine,

138 g (0.5 mol) of hexaethyleneheptamine,

301 g (1 mol) of the heterocyclic polyamines described by the formula h ₂ n • ch ₂ ch ₂ nh

3.05 _of ch ₂ ch ₂ ch ₂ n ^of N-CH ₂ CH ₂ NH ₂ /

CH ₂ CH ₂

265 381

The mixture is heated to 60-62 ° C and 182 g (0.50 mole) of a low molecular weight diane epoxy resin having a molecular weight of 364 is added dropwise over 3 hours. After completion of the flask, the reaction mixture is allowed to react for 60 minutes. The product is a liquid having a viscosity of 12,432 mPa · s / 25 ° C having an amine number of 695 mg KOH / g and an equivalent weight of 53.78.

Example 4

3 moles of a mixture of polyamines having the composition: 35.0% diethylenetriamine, 34.4% triethylenetetramine, are introduced into the apparatus,

14.2% N-aminoethylpiperazine and 16.4% bis- (N, N'-aminoethyl) pi perazine. The mixture is heated to 50-52 ° C and 98.1 g (1 mol) of cyclohexene oxide are added dropwise with stirring and cooling for 3 hours. After completion of the dropwise addition, the reaction mixture was allowed to react for 2 hours at 98-100 ° C, then cooled to 40-42 ° C and 15 g of 1,4-butanediol diacrylate were added dropwise over 30 minutes. The product is a viscous liquid having an amine number of 890 mg KOH / g equivalent weight 42.71 and a viscosity of 1890 mPa.s / 25 ° C.

Claims (1)

Adducts, in particular for curing and modifying epoxy resins, obtainable by reaction of a mixture of polyamines consisting of 20 to 90 wt. % aliphatic polyamines of structure h ₂ n-ch ₂ ch ₂ -L-nhch ₂ ch ₂ ' I 1-4 -NH, 10 to 90 wt. % of the heterocyclic polyamines of the structure CH _O CH _O CHoCH ₀ NH - H, Yeah-4 CHgCHg with aliphatic, cyclanic or aromatic epoxy compounds having an average molecular weight of 44 to 600, in a polyamine: epoxide molar ratio = 1 to 10: 1. h ₂ n CH ₂ CH ₂ NH ' 10-4 -CHgCH N N-