DE2203673A1 - Insulating film laminates - of glass-fibre fleece layers impregnated with modified epoxy resin - Google Patents

Abstract

The laminates are based onlayers of a) glass-fibre fleece impregnated with talc, CaCO3, quartz powder or "Aerosil" as filler and a halogenated epoxy resin prepreg of bisphenol A or B modified with formaldehyde precondensates or polyester resin and contg. accelerators or curing agents. They are gold stampable, non-flammable with good heat-resistance and are used as a base for printed circuits and as insulation tape.

Description

New laminates made of glass fiber reinforced and filled epoxy resin glass fiber fleeces on the basis of modified application compositions is the subject of the present invention are new laminates reinforced with glass fibers of a special kind that at least have a carrier impregnated with a filled synthetic resin.

Laminates in which the substrates are made of paper, textile fabrics, Synthetic fibers or inorganic fiber materials are also known, such as their processing with synthetic resin binders based on phenol-urea-melamine-polyester resins and also epoxy resins.

It is also known to use halogenated epoxy resins with halogen acceptors, such as antimony trioxide to be used to produce non-flammable laminates, or curing of the epoxy resins with elimination of the conventional amine or anhydride hardener with pure and unfilled formaldehyde precondensates, whereby general property improvements take place in the laminates.

The laminates according to the invention contain the following components Carrier materials, fillers and modified synthetic resins.

The carrier materials are special fiberglass fleeces, which are also microlith fiberglass fleeces to be named. These special glass fiber fleeces consist of glass staple fibers of different types Length and from individual fiber elements, whereby the fiber distribution is random and two-dimensional is in the form of a sheet.

In particular, have proven to be special for the purposes of the invention Well proven microlith glass fiber fleece of the type o.R.50 / NG, which is produced by the Schuller / Wertheim company.

The technical processing, the choice of raw materials and the composition these fleeces allow the application masses to be absorbed up to @ times theirs @ own weight.

One advantage is the wide range of variation in the application weights. They can be adjusted depending on quality expectations and economic aspects and move accordingly depending on the area of application of the laminate.

Mixed carrier material ions can also be used according to the invention are made, for example, of up to 60 g of the special glass fiber fleece and up with 40% cellulose.

The known fillers are suitable as fillers in the context of the invention such as talc, calcium carbonate, qua @@ flour, Ärosil and the like. Of these fillers talc is preferred @ t.

The synthetic resins contained in the plastics according to the invention are with accelerate @@ or @ ä @ tern pr @@ o @ lated and halogenated Epoxy resins based on bisphenol A or bisphenol B, which contain modified formaldehyde precondensates or polycster resins are modified.

The modified or modified formaldehyde precondensates are Reaction products from a) formaldehyde, paraformaldehyde or hexamethylenetetramine with b) in turn modified phenols, cresols, xylenols, urea and melamine.

The modifiers are.

for the phenols: simple or mixed phosphoric acid esters of different, optionally halogenated, monohydric or polyhydric phenols and alcohols for the cresole resp.

Xylenols: rosin or ilolzöl or other corresponding compounds, the resin acids with conjugated double bonds contain urea or

Melamine: alkyl or arylguanamines, toluenesulfonamides and the like.

These modifiers can be used during or after the resole condensation be mixed or reacted with the precondensates.

Under unsaturated polyester resins are in the context of the invention Understood coordinated mixtures, generally each one of the following compounds Groups contain: 1. polybasic unsaturated carboxylic acids, such as maleic acid, Fumaric acid, itaconic acid or their anhydrides, optionally also saturated, polybasic ones Acids, such as succinic acid, adipic acid, sebacic acid, phthalic acid, Isophthalic acid and tetrachlorophthalic acid.

2. Unsaturated monohydric or saturated dihydric alcohols such as e.g. allyl alcohol, glycols, e.g.

Ethylene glycol, 1,3-butylene glycol, 1,2-propylene glycol and neopentyl glycol.

3. Unsaturated polymerizable compounds such as e.g.

Styrene, cyclopentadiene, vinyl acetate, cyclohexene, diallyl phthalate or methyl methacrylate.

Polyester resins have proven to be particularly suitable for the invention which are manufactured by the Reichhold-Chemie company and as resin types UP 403 and UP 320 are designated and used with or without curing initiators can be.

The modified or modified formaldehyde precondensates mentioned above and the unsaturated polyester resins are also used as co-solvents in this application for the halogenated epoxy resins.

The laminates according to the invention have compared to those previously used Systems have significant advantages overall.

These advantages lie in a considerable reduction in costs. To the For others, the new laminates will improve the technical handling improved. In particular, the advantages of the new laminates lie in the improvement in quality and in the expansion of their properties, which has been the case with comparable laminates up to now did not exist.

Particularly noteworthy is the excellent cold punchability of the new laminate c-.

The addition of fillers, e.g. talc, reduces costs and also property improving. The lubricant effect also increases the adhesion the tools (press molds, press plates, winding mandrels) are considerably reduced.

Polyester films can be used instead of Tedlnr films as a release agent use, so that there are clear advantages in contrast to unfilled epoxy systems result.

At the same time, the surfaces can be improved as a result.

The superiority of the new systems is particularly evident compared to the epoxy hard paper @ (Hp) laminates that have been used industrially up to now according to DIN 7735 according to types 2361 and 2361.1 as follows: In the area of quality improvement 1. by a 5-fold increase in water resistance, furthermore by a considerable increase in the dielectric strength and improvement of the dielectric Loss factor with appropriate selection of the modification agent, 2. by a Much better punching behavior according to the design of punchability according to DIN 53 48 &, 2.1 cold-stampable sheet material up to 3 mm thick, 2.2 for. Heating temperatures from 50 - 70 ° C punched up to 4.5 mm, 2.3 absolute tolerance the punch cuts, 2.4 excellent contour sharpness of the cut edges and punch holes when punching.

3. By improving the thermal properties, 3.1 distortion and insensitive to shrinkage during temperature treatment, in short-term tests (3 h / 250 ° C): Free of distortion and shrinkage, in the long-term test (> 300 h / 195 ° C): shrinkage value # 0.4%.

3.2 Limit temperature according to VDE o304 - Part 2 - according to the thermal class Fx for long-term use according to wirine class lix for short-term use (but ~ 300 h) (x = without mechanical stress, since softening occurs beforehand).

3.3 due to high flexibility, also according to temperature effects and possible uses as post-forming quality in the area of property expansion, 4. through leakage current, Arc and carbon trace resistant behavior. In addition, the highest in individual cases Requirements for fire resistance and non-flammability met.

Compared to the previously used epoxy hard fabric laminates According to DIN 7735 according to types 2372 and 2372.4, the above also apply mentioned properties, as long as the special glass fiber fleece as a carrier material can be used.

The laminates according to the invention are produced in such a way that the Resin, hardener and filler components involved in the build-up of the coating materials as synthetic resin mixtures or as their pre-adducts in the form of solvent-based Resin-filler suspensions in the impregnation process on web-shaped and endless glass fiber fleeces are applied. Dahei must be dried and under temperature and pressure are hardened.

When compiling the application masses, the weight proportions predominate of halogenated epoxy resins compared to the diluents (modified @ormaldehyde precondensates or Polvester resins), so not only the well-known excellent properties of epoxy resins, but far surpassed them, especially in terms of the water resistance, punchability, dielectric strength and with sufficiently high proportions to Talk @@ also in the temperature resistance and in the shrinkage behavior.

The proportion by weight of the filler in the finished laminates is expediently (e.g. talc) at least 2o% and that of the glass fiber fleece at least lo%, in advance more than 15%, if the highest requirements for non-flammability, tracking resistance, the arc strength and the carbon trace strength are to be met.

If, on the other hand, the proportion of waste predominates, the total level corresponds the values from the insulation behavior are still largely in accordance with DIN-standard application pure epoxy resins.

Quality grades in comparison to the predominance of proportions of However, epoxy resins result mainly in the temperature resistance, in which Punchability and flexibility. The tracking resistance, the non-flammability, the arc resistance and the carbon trace strength impaired.

The filler content (e.g. talc) is at least 20 but at most 50% increase. The proportion of glass fiber fleece was at least 10%.

Examples (with excess epoxy): 1.

From 1 mole of pllenol, 1 mole of formaldehyde and 0.06 mole of diphenyl cresyl phosphate becomes a liquid condensed with ammonia and modified with phosphoric acid ester Phenol-formaldehyde resole produced.

2.

From o.35 mol phenol, o.65 mol m-p-cresol, 1 mol formaldehyde and rosin, Consists of at least 90% abietic acid, which is condensed with ammonia and resin acid modified liquid phenol / cresol-formaldehyde-resol mixture manufactured.

3.

Different xylenol isomers, formaldehyde and Hdzöl become a produced with ammonia condensed and modified with Ilolzöl-Resole.

The water is withdrawn from all combinations from 1 to 3.

4th

From 1 mole of melamine, 2 - 2.5 moles of formaldehyde and o.p. toluenesulfonamide becomes an alcohol-soluble one condensed with ammonia and modified with toluenesulfonamide Made of melamine formaldehyde solid resin.

5.

Unsaturated polyester resin.

Unsaturated polyester resins are known. Can be used z.J3. Polyester resins manufactured by Reichhold-Chemie, for example the type UP 320 or UP 403.

The unsaturated polyester resin is treated with a curing initiator and the resin component from Example 6 mixed.

The resulting reaction products of 1 - 5 are filled with talc.

6th

The production of epoxy resins is well known.

The epoxy resin is halogenated and with a lower proportion on harder or accelerator pre-formulation @ t.

The brominated resins are particularly suitable as halogenated epoxy resins Epoxy resins. In this example a F.poxy resin of the type 0138 / H is used, which is produced by the company Riitaq, Duisburg.

The resin mixtures between 1st and 6th, 2nd and 6th or 3.

and 6th, 4th and 6th, 5th and 6th take place in such a way that the solid resin ratio of the individual combinations at least 20th 80 and at most 40 ; 60 is. The filler content is 20-30% by weight per 100 g of laminate optimal.

Example (with insufficient epoxy content) 7.

A resol is produced as under l .; the mixture with resin 6. takes place in such a way that the solids ratio between the two components is at least 55:45 and a maximum of 70:30. The filler content (e.g. talc) is per 100 g of laminate with 35 - 45% by weight is optimal.

The application weights of the individual mixtures from 1. with 6., 2. with 6th, 3rd with 6th, 4th with 6th, 5th with 6th and 7th with 6th

are diluted with a solvent mixture of acetone / methanol (1: 1). Then microlith glass fiber fleeces of the type O.R.50 / NG impregnated with the filled resin solutions with a basis weight of 50 g / m2 and dried so that a mass application of at least 200 g, but at most 45o g / n2 results.

The individual layers are stacked on top of one another and in a press at 160 - 170 ° C and a pressure of 50 - 100 kg / cm2, each with a thickness of 1.5 mm Pressed plate.

In general, the use of the mixtures mentioned results in the properties presented above.

However, depending on the composition of the recipes, such as through the selection of the modifying agent, the degree of modification of the filler content le etc.

generate certain focal points in the self-image.

These are for the individual mixes: 1 with 6: Water resistance (2 - 5 mg), punchability at 20 ° C: K 1.3 - 1.6 post-forming properties (Processing temperature <100 ° C) 2 with 6: water resistance (2 - 5 mg), dielectric strength = 35 to 40 KV / 1.5 mm, dielectric loss factor tg. @: # 0.01 increased heat resistance (according to Martens) 3 with 6: water resistance (5 - lo m), punchability at 20 ° C: KW 1.5 - 2.0 dielectric strength: 30 - 35 KV / 1.5 mm 4 with 6: increased tracking resistance (KA3c) glow resistance etc., increased heat resistance (according to Martens) and insulation properties Reduced punchability.

5 with 6: Reduced insulation properties, post-forming quality 7 with 6: Insulation properties slightly reduced, on the other hand increased temperature resistance, lowest shrinkage values, high flexibility.

The epoxy laminates according to the invention can e.g.

as a base material for copper (Cu) laminated designs and on both sides, as a base material for multi-conductor systems for the production of printed circuit boards, e.g. for computers, electronic data processing apparatus, as flexible tapes in insulation technology, as a top layer @.

material can be used for the production of mixed laminates, etc.

Claims (15)

P a t e n t a n s p r ü c h e 1. New laminates that use special glass fiber nonwovens as carrier materials, as fillers talc, calcium carbonate, quartz flour or ærosil and as synthetic resins with accelerators or hardeners preformulated and halogenated epoxy resins Bisphenol A or bisphenol B-based, those with modified formaldehyde precondensates or modified polyester resins. 2. Laminates according to claim 1, characterized in that the special glass fiber fleece made of glass staple fibers of different lengths and made of individual fiber elements, whereby the fiber distribution is random and two-dimensional is in the form of a sheet. 3. Laminates according to Claims 1 and 2, characterized in that that the special clas fiber fleeces microlith glass fiber fleeces, especially the Type o.R.50 / NG are. 4. Laminates according to Claims 1-3, characterized in that the filler is talc. 5. Laminates according to Claims 1-4, characterized in that the modified formaldehyde precondensates the reaction products from a) formaldehyde, Paraformaldehyde or hexamethylenetetramine with b) their own modified phenols, Are cresols, xylenols, urea or melamine. 6. Laminates according to claim 5, characterized in that daP, the Phenols with simple or mixed phosphoric acid esters of different, optionally halogenated monohydric or tubular phenols or alcohols are modified. 7. Laminates according to claim 5, characterized in that the Cresols and xylenols with rosin or wood oil or other corresponding compounds, containing resin acids with conjugated double bonds are modified. 8. Laminates according to claim 5, characterized in that the Iarn or melamine with alkyl or aryl guanamines or toluenesulfonamides are modified. 9. Laminates according to Claims 1-4, characterized in that the unsaturated polyester resins from a balanced mixture generally each a compound of the following groups: a) polybasic unsaturated carboxylic acids or their anhydrides or saturated polybasic acids, b) unsaturated monohydric acids or saturated dihydric alcohols c) unsaturated polymerizable compounds from the group consisting of styrene, cyclopentadiene, vinyl acetate, cyclohexene, diallyl phthalate or methyl methacrylate. lo. Laminates according to Claims 1 - 4 and 9, characterized in that that the unsaturated polyester resin is a resin of the type UP 403 or UP 320. 11. Laminates according to claims 1-4 and 9 and lo, characterized in that that one uses the unsaturated polyester resins with curing initiators. 12. Laminate according to claims 1-11, characterized in that that they have a higher carbon weight percentage of halogenated epoxy resins compared to the modified Contain formaldehyde precondensates or polyesters. 13. Laminates according to claims 1-12, characterized in that they contain at least 20 t filler weight percentage. 14. Laminates according to Claims 1 - 13, characterized in that that the proportion of glass fiber fleeces is at least lo%, preferably more than 15% amounts to. 15. Use of the laminates according to claims 1-14 @ as base material for strip conductor systems for the production of printed circuit boards, as flexible strips in insulation technology and as a base material for printed circuits in electrical Devices such as televisions, electronic data processing apparatus for computers and radios.