JPS6226648B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flame-retardant epoxy resin composition for substrates suitable for laminates and copper-clad laminates. More specifically, the present invention relates to a novel epoxy resin composition for flame-retardant substrates that has good transparency and maintains excellent heat resistance, electrical properties, and chemical resistance. In recent years, with the development of electrical and electronic equipment, there has been a strong desire for laminates used in these fields to be flame retardant from the viewpoint of safety. On the other hand, in order to streamline the inspection of printed wiring boards, even flame-retardant substrates are required to have the same transparency as flame-retardant substrates. As a means of making such a laminate plate flame retardant,
Generally, a method using a halogenated epoxy resin or a flame retardant such as an organic halogen compound, an organic phosphate compound, or an inorganic compound is used. However, these methods require a large amount of use in order to achieve sufficient flame retardant effect, especially the degree of flame retardation that has been strongly desired in recent years, and meet the UL standard 94V-O, so they are expensive. There are problems such as pinching, deterioration of physical properties such as heat resistance and electrical properties of the laminate, or loss of transparency of the laminate, and further improvements are desired from the viewpoint of cost and performance. ing. In particular, diantimony trioxide, an inorganic flame retardant, exhibits excellent flame retardant effects due to synergistic effects with halogen atoms, and is therefore widely used as a flame retardant for various plastics along with various halogen-containing compounds. When this product is used as a flame retardant for laminates, especially epoxy resin to glass cloth laminates,
The problem arises that the transparency of the laminate is lost, which complicates the product inspection process as described above. In view of the above circumstances, the present inventors conducted research to solve these problems and found that by using a specific diantimony pentoxide as part of the flame retardant, good transparency can be achieved. The present invention was completed based on the discovery that a flame-retardant epoxy resin composition suitable for use in laminates and copper-clad laminates, which maintains excellent heat resistance, electrical properties, and chemical resistance, can be obtained. That is, the present invention provides an epoxy resin composition for producing a laminate or a copper-clad laminate, in which: (a) a non-halogenated epoxy resin having at least two or more epoxy groups in the molecule; (b) at least two or more epoxy groups in the molecule. Halogenated epoxy resin c having an epoxy group with an average particle diameter of 5 to 100 millimicrons and/or composed of secondary aggregates of primary particles with an average particle diameter of 5 to 100 millimicrons and an average particle diameter of 1 to 100 microns The present invention relates to an epoxy resin composition for flame-retardant substrates, characterized in that it contains a diantimony pentoxide curing agent within the range of 1. When the epoxy resin composition of the present invention is used for a laminate based on glass cloth, the laminate obtained has good transparency despite the addition of diantimony pentoxide, an inorganic compound. The laminate does not become opacified as is observed when antimony trioxide is used. Further, the diantimony pentoxide used in the present invention exhibits an excellent flame retardant effect even when added in a small amount due to its synergistic effect with halogen atoms, so that costs can be reduced. For example, as will be made clear in the examples described later, there are advantages such as the ability to greatly reduce the amount of expensive brominated epoxy resin used to achieve flame retardancy of UL94V-O. have. Furthermore, the laminate obtained using the epoxy resin composition of the present invention has little color deterioration at high temperatures and can be used stably for a long period of time. It also maintains excellent soldering heat resistance, electrical properties, and chemical resistance.
Its usefulness as a material for highly reliable printed wiring boards is extremely high. Furthermore, since the antimony pentoxide used in the present invention is ultrafine particles, aggregates of ultrafine particles, or a mixture thereof, it has excellent uniform dispersibility even in the varnish for impregnating the base material. No sexual deterioration was observed at all. The present invention will be explained in more detail below. In carrying out the present invention, at least 2
Examples of non-halogenated epoxy resins having more than one epoxy group include dilycidyl ether type dihydric phenols such as bisphenol A, bisphenol F, resorcinol, hydroquinone, 44'-dihydroxydiphenyl, bisphenol S, and phenols. - Examples include polyglycidyl ether type polyhydric phenols such as formaldehyde resins. Further, examples of the halogenated epoxy resin having at least two or more epoxy groups in the molecule include diglycidyl ether type brominated or chlorinated divalent phenols as exemplified above. Further, as the curing agent, any curing agent can be used as long as it does not impair the purpose of the present invention, and examples thereof include dicyandiamide, acid anhydrides such as phthalic anhydride and hymic anhydride, and various amine compounds. I can do it. Further, a curing accelerator can be used in combination with the epoxy resin composition used in the present invention, if necessary. Examples include tertiary amines such as benzyldimethylamine and triethylamine. Further, as mentioned above, the diantimony pentoxide used in the present invention may be ultrafine particles having an average particle size of 5 to 100 microns, or secondary aggregates of the ultrafine particles having an average particle size of 1 to 100 microns. Any mixture thereof may be used, and any known method for producing diantimony pentoxide may be used as long as the particle size satisfies the above-mentioned requirements. It is difficult to manufacture particles having an average particle diameter of 1 micron or less, and particles having an average particle diameter of 100 microns or more are undesirable because of their poor miscibility with resins. Further, the form in which diantimony pentoxide is used is not particularly limited, and it may be used in a powder state or a colloid state uniformly dispersed in an organic solvent capable of dissolving the epoxy resin used. I can do it. The ratio of the non-halogenated epoxy resin, halogenated epoxy resin, and diantimony pentoxide used in the present invention should be appropriately selected in consideration of the content of the halogenated epoxy resin used and the desired degree of flame retardation. Bye. For example, as will be clarified in the examples below, in order to achieve the highest degree of flame retardancy, UL standard 94V-O, the bromine content of the halogenated epoxy resin must be
When using 18 to 20 wt% of brominated epoxy resin, the ratio of non-halogenated epoxy resin: brominated epoxy resin = 1:1, about 3 parts by weight of diantimony pentoxide to 100 parts by weight of the total epoxy resin. preferable. The amount of the curing agent to be used may be appropriately determined depending on the epoxy equivalent of the epoxy resin used, the amount used, and the type of curing agent used. Furthermore, when creating a varnish for manufacturing laminates using the composition of the present invention, an organic solvent that uniformly dissolves a non-halogenated epoxy resin, a halogenated epoxy resin, and a hardening agent is appropriately selected. After dissolving the above three components in an organic solvent, diantimony pentoxide may be added and uniformly dispersed. In addition, various other additives may be used in combination as long as they do not impair the objectives and effects of the present invention. The present invention will be explained in more detail with reference to Examples below. Example 1 a Preparation of varnish for manufacturing laminates Epicote 1001, a bisphenol A type epoxy resin, was used as a non-halogenated epoxy resin.
(Epoxy equivalent 450-500) 50 parts by weight, brominated bisphenol A as halogenated epoxy resin
Epicoat 1045B-80, a type epoxy resin
(Epoxy equivalent 450-500, bromine content in resin
62.5 parts by weight of methyl ethyl ketone 42.5 parts by weight
4 parts by weight of dicyandiamide as a curing agent, 0.2 parts by weight of benzyldimethylamine as a curing accelerator, and 0.2 parts by weight of benzyldimethylamine as a curing accelerator are added to the solution dissolved in 30 parts by weight of dimethylformamide and mixed well. Next, 3.1 parts by weight of diantimony pentoxide was added and stirred and mixed to uniformly disperse the mixture in the system to prepare a varnish for producing a laminate. The diantimony pentoxide used in this example was in the form of a powder with an average particle size of 38 microns, but this was a secondary aggregate of ultrafine particles with an average particle size of 15 millimeters. Furthermore, the total solid content of the above varnish is 55.8% by weight, the bromine content in the total solid content is 8.85% by weight, the antimony content is 2.18% by weight, and the bromine/antimony ratio is
It is 4.06. b Manufacture of laminate A glass woven fabric having a thickness of 0.18 mm was impregnated with the above varnish and dried to obtain a prepreg with a resin content of 50% by weight. Eight sheets of this prepreg were stacked and press-molded under heating. Molding conditions are press temperature 170
℃, press pressure of 70 Kg/cm ² , and press time of 20 minutes. Next, the obtained laminate was post-cured at 170°C for 60 minutes to obtain a laminate. Separately, a copper-clad laminate with a 35μ thick copper foil was also manufactured. The method and conditions were the same as above. The physical properties, electrical properties, and flame retardance of the laminates were evaluated. The results are shown in Table 1. Example 2 a Preparation of varnish for manufacturing laminates All procedures were carried out except for using diantimony pentoxide in powder form with an average particle diameter of 46 microns, which is a secondary aggregate of ultrafine particles with an average particle diameter of 48 millimicrons. A varnish was prepared in the same manner as in Example 1-a. Therefore, the total solid content in the varnish and the bromine/antimony ratio in the solid content are also the same as in the varnish of Example 1-a. b Production of laminate A laminate was produced using the same method and conditions as in Example 1-b. The results are shown in Table 1. Comparative Example 1 a Preparation of varnish for manufacturing laminates As a typical formulation example for manufacturing flame-retardant laminates that comply with NEMA standard FR-4 or JIS standard GE-3, C.
A varnish was prepared with reference to the formulation example described on page 59 of MC Technical Report No. 17 Printed Wiring Materials and Processing Technology (edited by Torao Higaki, published by CMC Corporation, November 20, 1980). That is, 125 parts by weight of an 80% by weight methyl ethyl ketone solution of the brominated epoxy resin Epicoat 1045-B-80 used in Example 1-a (100 parts by weight as brominated epoxy resin) was diluted with 35 parts by weight of methyl ethyl ketone, and then A solution prepared by dissolving 4 parts by weight of dicyandiamide as a hardening agent and 0.2 parts by weight of benzyldimethylamine as a hardening accelerator in 30 parts by weight of dimethylformamide was added and mixed well to obtain a varnish. The total solids content of this varnish is 53.7% by weight. b Production of laminate A laminate was produced using the same method and conditions as in Example 1-b. The results are shown in Table 1. As is clear from the results in Table 1, in this comparative example, a laminate meeting UL standard 94V-O can be obtained using only an expensive brominated epoxy resin containing 18 to 20% by weight of bromine. On the other hand, in Examples 1 and 2, excellent flame retardant effects were observed even if the amount of brominated epoxy resin used was halved. Furthermore, when comparing the performance of this comparative example other than flame retardance with Examples 1 and 2, the transparency of the laminate was improved in the laminate to which diantimony pentoxide was added, and the transparency of the laminate was improved. It can be seen that diantimony pentoxide is extremely finely and uniformly dispersed. In addition, the bending strength of the laminates in Examples 1 and 2 is improved, and there is no deterioration in electrical properties, soldering heat resistance, boiling water absorption rate, etc., and the laminates to which diantimony pentoxide is added have excellent performance. is clear. Comparative Example 2a Preparation of varnish for manufacturing laminates A varnish was prepared in the same manner as in Example 1-a, except that diantimony trioxide powder with an average particle size of 0.5 microns was used instead of diantimony pentoxide. I went. The total solids content in the varnish is 55.8% by weight, and the bromine/antimony ratio in the solids is 3.67. b Production of laminate A laminate was produced using the same method and conditions as in Example 1-b. The results are shown in Table 1. As is clear from Table 1, the flame retardancy, electrical properties, mechanical properties, soldering heat resistance, boiling water absorption, etc. of the laminates to which antimony trioxide was added were compared with the results of Examples 1 and 2. There is no big difference, but
It can be seen that transparency has deteriorated significantly. In fact, the laminate obtained in this comparative example has a white color and its transparency is significantly impaired, and in this state, the object of the present invention cannot be achieved at all. 【table】

Claims (1)

[Scope of Claims] 1. In an epoxy resin composition for producing a laminate or a copper-clad laminate, a non-halogenated epoxy resin having at least two or more epoxy groups in the molecule, b at least two in the molecule. Halogenated epoxy resin c having an epoxy group of 5 to 100 mm, consisting of a secondary aggregate of primary particles with an average particle size of 5 to 100 millimicrons and/or an average particle diameter of 5 to 100 millimicrons, and an average particle diameter of 1 to 100 millimicrons.
A flame-retardant substrate epoxy resin composition, characterized in that it contains as a component a diantimony pentoxide curing agent within the range of 100 microns.