JPH04153212A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To prepare the title compsn. giving a cured article excellent in heat resistance, humidity resistance, and dielectric properties by compounding an epoxy resin obtd. by reacting an adduct of a phenol with a butadiene (co)polymer with epichlorohydrin into the compsn. CONSTITUTION:The title compsn. contains, as its resin component, an epoxy resin obtd. by reacting an adduct of a phenol with a butadiene (co)polymer (pref. 100g of the adduct contains 0.1-1mol of phenolic hydroxyl groups) with epichlorohydrin, has a low viscosity and hence good handleability, gives a cured article excellent in heat resistance, humidity resistance, and dielectric properties, and is useful in many applications, e.g. for a molding material, an adhesive, and a coating material.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to novel epoxy resin compositions that can be used in a wide variety of applications.

BACKGROUND OF THE INVENTION Epoxy resins are used in a wide range of fields because of their good heat resistance, electrical properties, and moisture resistance. General-purpose epoxy resins are liquid or solid ones obtained by reacting bisphenol A with epichlorohydrin. There are also polyfunctional epoxy resins obtained by reacting novolac resins with epichlorohydrin.

In order to improve the properties of these epoxy resins and improve their dielectric properties, heat resistance, and moisture resistance, we added phenol-added butadiene (co)polymer to the bisphenol A epoxy resin and novolak epoxy resin. A composition containing
Publication No. 6).

Problems to be Solved by the Invention The technology disclosed in the above-mentioned publication is said to have improved dielectric properties, heat resistance, and moisture resistance, but these property improvements are due to the addition of phenols to butadiene (co)polymer. This is achieved by using a combination as a curing agent for an epoxy resin and incorporating a butadiene skeleton into the cured epoxy resin.

Therefore, the amount of phenol-added butadiene (co)polymer to be used is limited to an amount whose OH equivalent is commensurate with the epoxy equivalent of the epoxy resin to be blended, and it cannot be used in large quantities. It seems that it is still insufficient. Furthermore, since the phenol-added butadiene (co)polymer has a high viscosity, it does not have good workability when used.

The problem to be solved by the present invention is to take this further and create an epoxy resin composition that can be expected to have improved heat resistance, dielectric properties, and moisture resistance by incorporating a large amount of butadiene skeleton into the epoxy resin. The goal is to provide the following.

Another objective is to lower the viscosity and improve workability.

Means for Solving the Problems The epoxy resin composition according to the present invention is characterized in that it contains, as an epoxy resin component, an epoxy resin obtained by reacting a phenol-added butadiene (co)polymer with epichlorohydrin.

Function The epoxy resin composition according to the present invention is not used as a curing agent for epoxy resin as in the prior art, but is used as the epoxy resin itself, so there is a high degree of freedom in selecting the curing agent. A large amount can be incorporated into the cured product.

In addition, when the phenol-added butadiene (co)polymer is reacted with epichlorohydrin, the softening point of the resin is lowered by 30 to 60"C, and the viscosity of the resin solution is lowered, so it can be used at high concentrations. , improves workability.

Example Next, embodiments according to the present invention will be described.

Phenol-added butadiene (co)polymer used as a raw material for epoxy resin is produced by reacting a homopolymer of butadiene or a copolymer of butadiene with a vinyl monomer such as styrene or a diolefin such as isoprene with phenol. can be obtained. The catalyst is sulfuric acid, perchloric acid,
Aluminum chloride, boron trifluoride, boron trifluoride
These include ether complexes, boron trifluoride/phenol complexes, etc. The phenols may be monohydric phenols, polyhydric phenols, or alkyl-substituted phenols.

It is desirable to adjust the amount of phenols added so that the number of hydroxyl groups in 100 g of the produced adduct is 0.1 to 1 mole.If the amount of phenols added is small, the crosslinking density of the cured epoxy resin will decrease. If the amount is too small, the desired heat resistance cannot be sufficiently obtained, and if it is too large, the fluidity of the epoxy resin composition will be reduced.

The reaction between the phenol-added butadiene (co)polymer and epichlorohydrin is carried out in the presence of an alkali.The reaction conditions are the same as in the production of ordinary epoxy resins.
There is no particular restriction.

Add 0.7 to 10 moles of epichlorohydrin per hydroxyl group of the phenol-added butadiene (co)polymer, and heat at 20 to 120°C in the presence of sodium hydroxide.
A method such as carrying out an epoxidation reaction can be adopted. By adjusting the excess of epichlorohydrin to hydroxyl groups, the molecular weight of the product can be adjusted.

This epoxy resin can be blended as one of the epoxy resin components, but its curing agent is one that is commonly used.For example, aliphatic amines such as diethylenetriamine, triethylenetetramine, metaphenylenediamine, etc. , aromatic amines such as diaminodiphenylmethane, polyamides and modified products thereof, acid anhydrides such as maleic anhydride, phthalic anhydride, and pyromellitic anhydride, phenol novolac resin, cresol novolac resin, bisphenol A novolac resin, etc. , dicyandiamide, imidazole, BP, -amine complex, guanadine derivative, and the like.

As a curing accelerator, dimethylbenzylamine, tertiary amines, imidazoles, and various metal compounds can be blended. In addition, flame retardants, fillers,
Add colorants, etc.

This will be explained in detail below.

Synthesis Example 1 Polybutadiene (number average molecular weight: 1000°1.2 bonds: 58%) 100g phenol
250g of 37 boron fluoride/phenol complex 3.4g was charged into a flask equipped with a reflux condenser and a stirrer, and reacted at 80°C for 3 hours.

Xylene 300g Calcium hydroxide 8.6g Water
0.9 g was added, stirred at 90°C for 20 minutes, and then filtered.

Unreacted phenol, xylene, etc. were removed from the filtrate under reduced pressure to obtain a phenol-added butadiene polymer (C).

Next, 315 g of polymer (C) was added to 43 g of epichlorohydrin.
After dissolving in 0g, 440g of 20% aqueous sodium hydroxide solution was added dropwise over 5 hours while stirring at 80°C.
The reaction was further continued for 1 hour.

The aqueous layer was removed from the reaction solution, excess epichlorohydrin was distilled and recovered, and the resulting reaction product was dissolved in 400 g of toluene and washed with 130 g of water. After that, oil and water are separated, water is removed from the oil layer by azeotropic distillation, and then filtered.
Furthermore, toluene was removed to obtain an epoxidized phenol-added butadiene polymer (A) (epoxy equivalent: 375)
.

Synthesis Example 2 An epoxidized cresol-added butadiene polymer (B) was obtained in the same manner as Synthesis Example 1 except that the phenol added to polybutadiene was changed to cresol (epoxy equivalent: 390).

Examples 1 to 3, Conventional Examples 1 to 3 The above polymers (A) to (C) were mixed with bisphenol type epoxy resin (resin (1), epoxy equivalent: 510), phenol novolak type epoxy resin (4!! fat (2 ), epoxy equivalent: 178) Brominated bisphenol type epoxy resin (#/I fat (3), epoxy equivalent: 400. Bromine content:
48%) and the composition shown in Table 1.

Each composition was heated at 100°C for 2 hours - 160'C for 2 hours - 18
Table 1 also shows the characteristics test results of the specimens cured by a heating process of 0''C2 hours.

Margin below Table 1 Resin composition (parts by weight) In Table 1.

Curing agent Nidicyandiamide Curing accelerator = 2-ethyl 4-methylimidazole Water absorption.

dielectric constant.

Dielectric loss tangent: Measured according to JIS-C-6481 Tg (glass transition) temperature: Measured with a thermomechanical analyzer Effect of the invention As is clear from Table 1, the epoxy resin composition according to the present invention has high heat resistance. , provides a cured product with excellent dielectric properties and moisture resistance. It is extremely useful in a wide range of applications such as molding, adhesives, and paints. In addition, since the viscosity is low, it is easy to handle.

Claims (1)

[Claims] (1) An epoxy resin composition comprising, as an epoxy resin component, an epoxy resin obtained by reacting a phenol-added butadiene (co)polymer with epichlorohydrin.