FI64066B - FLUSSMEDELFORMKROPPAR - Google Patents

Description

1- ..__- I r-,,.,. WHERE IS A PUBLICATION, A ^ „^ (11utläggnjngsskrift 64 0 66 c (45); 'U Lc-r :: li', y 10 10 1733 ^ T ^ (51) Kv.lk. | lnt.CI? B 23 K 35 / 36 FINLAND —FINLAND (21) P »tenttlh * kemui - Pitenttnsöknlng 783 ^ 80 (22) Hakemlspilvä— Ansökningidag 1 ^ .11.78 (23) Alkupllva — Giltlghetsdag 1 ^ .11.78 (41) Has become public - Blivlt offentllg 20.07.79

Patents Board of Patents (44) Date of publication of the notice

Patent and registration authorities Ansökan utlagd och utl.skrlften publlcerad 50.0b.o3 (32) (33) (31) Pyydetty etuoikeus — Begird prlorltet 19-01.78

Federal Republic of Germany-Förbundsrepubliken

Tyskland (DE) P 2802187.6 (71) Degussa Aktiengesellschaft, Weissfrauenstrasse 9, 6000 Frankfurt 1,

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (72) Wolfgang Hasenpusch, Hanau, Karl-Friedrich Zimmermann, Heusenstamm,

Albert Heilmann, Alzenau, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (7 * 0 Oy Kolster Ab (51 *) Flux pieces - Flussmedelformkroppar

The invention relates to high-strength flux bodies which are in the form of coatings on individual pieces or welding materials and which contain a flux mixture and binders and which are particularly advantageous in terms of their non-fracture, flexibility, odor stress and moisture repellency.

Fluxes are used to promote the soldering and welding process. Fluxes are then used as powders, suspensions or solder pastes. In many cases, the combined use of flux and solder in the form of coated or fully coated stampings or wires has also proven advantageous.

In general, however, fluxes adhere only extremely poorly to metal solder bodies, even when the metal surface is roughened. Besides, even with extreme care, transport damage occurs in the package, causing large parts of the flux to come off.

The use of flux bodies, flux-coated stampings or moldings fails because the flux does not adhere well to the solder metal and the ductility of the flux body is deficient.

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Although the production of flux-coated solder bodies and flux-made parts is known (e.g. DE-OS 24 28 808), the lack of adhesion and formability limits the wider use. In this case, an organic or inorganic binder is added to the flux. Due to the high demands placed on the flux coating and body, only a binder can be used that both improves adhesion and allows the coated solder bodies to bend at least 90 ° due to high formability, but does not cause soot residue or otherwise negatively affect flux fusion. Odor stress as the flux melts is also undesirable. Thus, celluloses, polymethacrylates (DE-OS 2 336 442) and polyvinyl resins (CH-PS 588 325) also do not achieve high quality standards due to their carbon black and odor stress.

It was also not possible to substantially limit the embrittlement of the flux from the metal substrate by adding inorganic and / or metallic fibers (DE-OS 25 29 190).

DE-A-19 34 122 discloses solder pastes which contain polyoxyalkylene compounds having a boiling point of 260-540 ° and a molecular weight of 200-400 as binders. Such compounds cause sooting during soldering and are therefore not suitable for use in flux materials.

FI deposit application 782 823 describes thermoplastic plastics in general, formaldehyde plastics, natural resins and synthetic resins in particular, GB halogen-containing organic polymers are mentioned in GB patent publication 1 072 615. These compounds also have the disadvantage that they cause sooting during soldering and thus interfere with soldering.

Thus, it was an object of the present invention to provide a flux in the form of coatings on bodies or soldering or welding materials of various shapes, containing a flux mixture and a binder having good adhesion to metal substrates, good fracture toughness and flexibility, and no soot or odor stress. is moisture resistant.

According to the invention, this object is solved by adding ethylene-propylene copolymer polymer having a molecular weight of 50,000 to 500,000 as a binder to the flux mixture. The flux mixture .

The flux bodies according to the invention are preferably prepared by thoroughly mixing the flux components and the binder and shaping the mixture into a homogeneous paste in the mold into pieces or coatings. Preferably, the binder is swollen in an organic solvent. Many organic solvents are suitable as a swelling agent for ethylene-propylene copolymers. In practice, however, petrol fractions with a boiling range of 100 ° C on both sides, especially between 80-200 ° C, have been found to be particularly good.

All the ingredients that ultimately form a highly viscous paste are best mixed thoroughly in a blender.

The flux bodies of the invention containing ethylene propylene copolymers as a binder have been found to wett solder well and have been found to have good formability. Moreover, their thermal decomposition does not cause decomposition residues or lead to odor stresses.

Polyethylene or other aliphatic, long-chain compounds (stearin, waxes, fatty acids) are converted into carbonaceous cleavage products under the intense action of a soldering flame, which eventually remain as soot residues in the flux melt.

Polypropylene, on the other hand, burns steadily in itself. However, when exposed to intense heat under anaerobic conditions, sooting is observed.

Only the copolymerization of ethylene and propylene combines the advantageous properties in the desired way: formability and thermal decomposition without soot residue. Thermal decomposition, in which no soot decomposition products are formed, can be explained by the formation of small decomposition products which disappear as a gaseous material before being exposed to heat.

In addition to pure ethylene propylene copolymers, polyethylene propylene binders with aliphatic side chains are also useful. Copolymers of ethylene and / or propylene oxide derivatives have also proved to be good. Less suitable are aromatic moieties or other unsaturated components in the polymer.

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The proportion of binder in the dry mixture, based on the ethylene-propylene copolymers, can be from 0.5 to 30% by weight. The odor of the decomposition products is paraffinic and thus does not disturb.

The following examples illustrate some of the uses of the flux bodies of the invention.

Example 1

A mixture of 60% potassium pentaborate, 35% potassium tetrafluoroborate and 5% potassium hydrogen fluoride was mixed with 2% ethylene propylene copolymer in gasoline as a swollen gel. The viscosity required for further processing is adjusted by adding more solvent. This mixture is formed into pieces in a mold in the usual manner or coated with brazing rods or other soldering pieces in an electro-press.

The flux coatings or layers adhere so tightly to their metallic substrates that such solder pieces can be cut without the flux layer coming off. Even narrow spirals can be bent from such flux-coated rods. This flowability of the flow layer allows even simple editing. Soldering avoids the interfering odor stresses that occur in similar soldering processes when cellulose or acrylates are used as binders.

In addition, the flux bodies are moisture-repellent.

Example 2

To a flow mixture of 65% potassium pentaborate and 35% potassium tetraborate, 5% ethylene propylene copolymer polymer is added and the mixture is always heated according to thermoplasticity, mixed without solvent in a heated mixer, and the homogeneous paste is shaped into pieces or coated.

When the mixed air solvent is run, products with similar properties to the solvent are obtained. However, the working time is considerably reduced because it takes several hours for the solvent residues to evaporate.

Example 3

A mixture of brazing powder and flux consisting of 65% potassium tetraborate and 35% potassium tetrafluoroborate in a ratio of 3: 1 is homogenized with 3% ethylene-propylene poly

Claims (5)

5,64066 merisate and 2% ethylene oxide propylene oxide polymer polymer thermoplastically or with 1% ethylene propylene polymer polymer and 1% ethylene oxide propylene oxide polymer as a gel emulsion in gasoline, and the mixture is formed into bars or other pieces. This method, in which the flux and the solder are simultaneously fed to the soldering point, has the particular advantage that these pieces can be used in soldering machines, because they can be wound in half due to their elasticity. A flux consisting of a flux mixture and binders in the form of bodies or as a coating for soldering or welding materials, characterized in that it contains copolymers of ethylene and propylene having a molecular weight of 50,000 to 500,000 as binders. Flux according to Claim 1, characterized in that the components of the copolymers are propylene and / or ethylene derivatives. Flux according to Claim 1 or 2, characterized in that it contains oxide derivatives. Flux according to one of Claims 1 to 3, characterized in that the ethylene-propylene copolymers have a dry matter content of 0.5 to 30%. Flux according to one of Claims 1 to 4, characterized in that the ethylene-propylene copolymers contain branched components.