FI57889C - SAOSOM SLIPSTEN ANVAENDBAR ARTICLE ON THE FRAMEWORK OF RESOURCES - Google Patents

Description

γβΊ / «« advertisement publication c7öq0 year · w <") utlAggninosskrift 57889 C Fatent issued 10 11 1900

Patent raeddelat '(51) Ky.ik? /Im.a.3 B 24 D 3/02 FINLAND — FINLAND (21) HtmaMm ^ -r ******** 953/72 (22) Hakwnitpllvi — AnaekiiliitMhg 06.0 ¼.72 (23) ΑΝαιρΗνΙ — GUtlghradag 06.04.72 (41) Tulkit JulkMcsI - Bllvlt effwcllg 07.10.72

Patent and Registration Office (44) Date of issue and date of issue.

Patent · OCh registerstyrelsen AnaMctn uthtgd och utl. «Krif» n pubUcarad 31.07.80 (32) (33) (31) Requested atuolkaot — Baftrd prtorltat 06.OU.7i USA (US) 131650 True-Styrkt (71) E.I. du Pont de Nemours and Company, Wilmington, Delaware, USA (72) Dieter Klaus Bruschek, Bellach, Switzerland-Switzerland (CH),

This invention relates to a product for use as an abrasive stone and to a method for producing such a product. The present invention relates to a product for use as an abrasive stone and to a method for producing such a product. In particular, the invention relates to a product for use as an abrasive stone, comprising a) an organic resin-bonded phase having from 100 to about 30% by volume of? a substantially linear polyimide polymeric material based on the molding material in said resin-bonded phase and in addition up to about 70 by volume of J? a metal based on the casting material in the resin-bonded phase, wherein the resin-bonded phase also contains non-castable, abrasive particles, and b) a metal-bonded phase having 100 to about 70 volumes /? a metal based on the casting material in said resin-bonded phase and further up to about 30% by volume of a substantially linear polyimide polymer material based on the casting material in said metal-bonded phase.

Wearing structures, such as abrasive stones, the edge part of which is a polyimide polymer material which is glued to the metal core part, are known. A significant problem with these structures is that there is no simple and effective method of attaching the edge portion to the core portion. If, for example, the edge-core connection is weak, the edge part will come off during use. A considerable amount of work has been done to provide abrasive stone structures with an edge portion firmly attached to the 57889 core portion. For example, U.S. Patent No. 3 U70 0Ϊ + 7 discloses an improved resin-bonded abrasive stone in which an edge portion containing a self-adhesive is adhesively attached to the core portion such that the former applies a compressive force to the latter, thereby preventing the lateral portion of the edge portion from compressing. and radial detachment from the heart of the grindstone. Such studies are expensive and not always successful in all cases. It is therefore a main object of the present invention to provide shaped structures, such as abrasive articles, which are free from the above-mentioned drawbacks.

The product of this invention is characterized in that it is prepared by co-casting a resin-bonded and a metal-bonded phase.

According to the present invention there is also a process for the factory production of shaped structures, such as abrasive stones or hardstones with abrasives, comprising an organic resin-bonded phase and a metal-bonded phase, comprising co-casting said organic resin-bonded phase from a castable resin mixture to form a resin. a phase of 100 to about 30% by volume of fused substantially linear polyimide polymer powder and complementary up to about 70% by volume of castable metal powder with a metal-bonded phase of the casting alloy to form a metal-bonded phase between 100% and about 70% by volume Up to 30% by volume of a substantially linear fusible polyimide polymer powder, applying heat and pressure to co-molding compounds there.

The nature and advantages of the present invention will become more apparent from the following description and several drawings taken in conjunction with the accompanying drawings, in which like reference numerals refer to like parts throughout the figure and Figure 1 is a cross-sectional view of a shaped structure including a circular grindstone made by the method of the present invention. is a cross-sectional view of another application of a round grindstone, Figures 3, U and 5 are graphical representations of the physical properties of hot-pressed discs when pressed from mixtures of polyimide resin and copper-metal powder.

The co-cast product of the present invention is uniform in structure and contains at least two distinct homogeneous phases. The second phase is dominated by an organic resin-bonded phase and the second phase is dominated by a metal-bonded phase. Both phases may, if desired, contain moldable and non-moldable additives. An example of a co-cast product according to the invention is the grindstone according to Figure 1. The profile structure shown in Figure 1 to illustrate the invention relates to an abrasive grindstone comprising a core portion 10 made of a metal material and an edge portion 11 of an organic polymeric material and a suitable abrasive material. The core portion 10 is usually provided with a central opening 12 useful for mounting the grindstone on a suitable support. . Figure 2 shows an abrasive stone similar to that shown in Figure 1 except that the abrasive-containing part 13 is placed on the surface 14 of the core 10.

The organic resin-bonded phase in the co-cast product of the invention, i.e. e.g. the edge portion 11 of the grindstone, as shown in Figure 1, comprises from 100 to about 30% by volume of a substantially linear molded polyimide polymer material and complementarily up to about 70% by volume of molded metal powder. The above cast percentages by volume are based on the casting material in the organic resin-bonded phase, in the absence of non-castable additives, such as abrasive particles. The organic resin-bonded phase preferably further contains abrasive particles, such as, for example, diamond or coated diamond particles or silicon carbide. The organic resin-bonded phase may contain up to about 40% by volume of additives, such as diamond abrasive particles. Coated diamond means diamonds with an electrolytically or chemically deposited thin layer of nickel or copper or silver, etc.

The polyimide polymer material of the organic resin-bonded phase is characterized by the following periodically reversible structural formula: 0 0 fl tf - ^^ N-R '- (1)

C

M It 0 o rt rt 57889 4 wherein R is a tetravalent aromatic radical containing at least one ring of six carbon atoms characterized by benzenoid unsaturation, the four carbonyl groups of said periodically recoverable moiety being attached to separate carbon atoms attached in pairs to each carbonyl group of each pair in said H radical; and wherein R 'is a divalent aromatic radical.

Polyimides are prepared by the reaction of at least one organic diamine, the diamine having the structural formula: H2N-R'-RH2 (2) wherein R 'is as defined above and two amino groups of said diamine are each attached to separate carbon atoms of said aromatic radical, with at least one tetracarboxylic acid dianhydride, the latter having structure formula: <x>

C C

Where R is as defined above, in an organic solvent the solvent is inert to the reactants, preferably under anhydrous conditions with a reaction time and a temperature below 175 ° C such that sufficient time is formed to form polyamic acid which is then converted to the above polyimide by suitable methods such as heat. ). Suitable polyimides for the process of this invention are those based on e.g. pyromellitin dianhydride and 4 ', 4'-oxydianiline or based on 3', 3 ', 4', 4'-benzophenone tetracarboxylic dianhydride and 4 ', 4'-oxydianiline or metaphenylenediamine. Suitable polyimides are described in more detail in U.S. Pat. 3,179 »631 and- 3» 249 »588. The above polyimides can be utilized either alone or in mixtures in said resin-bonded phase.

The metal-bonded phase of the co-cast product of the invention, i.e., e.g., the grindstone core portion 10 of Figure 1, comprises about 70-100 volume percent cast metal powder and complementary up to about 30 volume percent 57889 percent cast filler, such as a cast polyimide polymeric material. The metal powder is preferably present in the metal cast phase in an amount of about 80-100% by volume. The metal powder for the core portion 10 is preferably one having a melting point at least 100 ° C above the casting temperature used. Suitable examples of metal powders in the metal cast phase are copper, aluminum, brass or bronze. Suitable non-castable additives can be used for the metal casting phase.

The additives can be incorporated into the organic resin-bound phase, i.e. e.g. the edge part 11, or into the metal-bound phase, i.e. e.g. the core part 10, if so desired. In some cases, for example, it may be desirable to add additives to the edge portion 11 to adjust its properties. The castable metallic additive may be added to the castable organic resin-bonded edge portion 11 phase and the castable resin additive may be added to the castable core-metal phase of the core portion 10. In this regard, an essential feature of the present invention is the finding that the co-casting of the molded organic resin bonded phase and the cast metal bonded phase must be performed under conditions where the organic resin bonded phase comprises 100 to about 30 volume percent polyimide polymeric material and the metal bonded phase comprises about 70 to 100 volume percent metal. The organic resin-bonded phase preferably contains an abrasive material such that it comprises from 100 to about 50% by volume of polyimide. Figures 3 and 4 illustrate the basis of the above essential feature of the invention. Figure 3 is a graphical representation of tensile strength and is shown as an ordinate and volume percent is shown as an abscissa, and the data are obtained by analyzing a disc-shaped structure prepared by hot pressing at 450 ° C a . Figure 3 shows that the properties of the cast mixture of polyimide resin and copper metal change at point B, indicating that a continuous organic resin-bonded phase exists between points A and B in Figure 3 and that a continuous metal phase exists between points B and C in Figure 3. The tensile breaking strength of the continuous organic resin-bonded phase increases linearly from 100% by volume of resin to about 30% by volume of resin, where there is a bend and a change in the nature of the curve. The bend indicates that the metal-bonded phase becomes Continuous at point B in Figure 3. Continuous metal-bonded! the tensile breaking strength of the phase increases linearly and as shown, but at a much higher rate between about point B of metal containing 70% by volume and point C of metal containing 100% by volume. Figures 4 6 57889 and 5 show substantially similar results for elongation at break and bending strength of the disc structure. Substantially the same results as shown in Figures 5 to 4 and 5 have been obtained for hot-pressed polyimide polymer material and aluminum powder discs.

A striking feature of the present invention is in co-casting, in which a metal phase is cast to form a core 10 and an organic resin phase, e.g., to form an edge portion 11. This is preferably done by first filling a suitable mold with a core element with a castable resin mixture such as polyimide powder containing the desired additives such as diamond abrasive particles. The mixture of castable polyimide powder and diamonds is partially combined in casting and the core element of the mold is then removed. The core cavity of the mold is then filled with a castable mixture of metal powder and using the desired additives, whereby these are partially combined. Another method is to mold the metallic powder in a separate operation step, and the preforming or preform thus formed is then placed in the core cavity of the mold. The mold and its contents are then heated to about 100-300 ° C in a vacuum oven for 15 minutes. - 5 hours. The heated mold is then pressurized and heated to about 350-500 ° C. A pressure of about 280-3500 kp / Czn is applied to the mold for a period of time sufficient to seal the preform and cause fusion to both the resin and the metal powder, i.e., 20-30 minutes. The mold is then cooled while being kept under pressure and after cooling the grindstone is removed from the mold. The abrasive stone is then finished by a conventional method, e.g. by coating, drilling a central mounting hole and balancing.

Any suitable casting technique can be used for the co-casting structures of this invention. Satisfactory results have been obtained using a compression mold, and in particular compression molds that utilize pistons on opposite sides (ram).

The principles of the present invention and its use will now be explained in the following examples, which are merely illustrative and are not intended to limit the scope of the invention, as many modifications in both technique and operation will be apparent to those skilled in the art.

Example 1

A mixture of 2.40 g of poly-N, N '- (4', 4-oxydiphenylene) -pyromellimide, 13.64 g of dendritic copper powder and 10.13 g of nickel-plated diamonds containing approximately 56% by weight of nickel (based on coated diamonds), obtained by dry mixing, was flattened into a cavity formed by a cylindrical mold with an inner diameter of I50 mm, a cylindrical core with an outer diameter of 13.75 mm, and two mold rings. The powder was pre-compacted using a pressure of 210 kp / cm. The casting core was removed and the cavity was filled with dendritic copper powder pre-compacted at 350 kp / cm to form a preformed edge portion and a core portion. The mold and its contents were heated in a vacuum oven at 150 ° C for about 4 hours. The hot mold was placed under pressure on a plate heated to 450 ° C and heated under contact pressure to 445 ° C. A pressure of 1050 kp / cm was applied to the mold for 20 minutes at a temperature of 445-450 ° C. After cooling to 250 ° C under pressure, the cast abrasive stone was taken out. The finishing steps, which included smoothing, drilling and balancing the central mounting hole, formed an abrasive stone with a diamond concentration of 100 (diamond concentration of 100 means that the stone has 72 carats of diamonds per 16,387 cubic centimeters (emis). The edge of the cast abrasive stone (organic resin bonded phase) 35% by volume of polyimide, 30% by volume of dendritic copper, and 37% by volume of nickel-plated diamonds (25% by volume of diamond and 12% by volume of nickel). .

The grindstone was used to grind cemented tungsten carbide until the edge portion was worn without detecting cracks or detachment of the edge portion from the core portion.

Example 2 A 50 mm diameter D1A1 (American Standards Association) grindstone was prepared with an edge portion (resin phase) of poly-N, N '- (4f4'-oxide-phenylene) pyromellitimide and SiC, and a core portion (metal phase) of aluminum and poly-N , N '- (4', 4-oxydiphenylene) pyromellitimide, having the following composition:

Edge (resin-bound phase)

Polyimide - 26% by volume Copper - 49 - "-

SiC - 25 - "-

Molded material - 34% by volume polyimide and 66% by volume copper.

Core part (metal bonded phase)

Aluminum - 70% by volume Polyimide - 30% by volume.

8 57889

The resin and the alloys were co-cast at a temperature of 450 ° C and a pressure of 875 kp / cm by the method of Example 1 to produce a grindstone.

Example 3

An 8.9 nm »diameter strip was prepared having poly-Ν, Ν '(4,4'-oxydiphenylene) pyromel-lithimide and SiC and a support (metal-bonded phase) as an abrasive layer (resin-bonded phase) having the following composition :

Abrasive layer (resin bonded phase)

Polyimide - 25 »1 volume percent

Copper - 20.5

SiC - 24.4 - "-

Cast material - 35 »3% by volume polyimide and 66.7% by volume copper.

Support layer (metal bonded phase)

Copper - 100% vol o 2

The strip was cast at 450 ° C and using a pressure of 1750 kp / cm modified by the method of Example 1 to prepare an abrasive layer preform by compacting the abrasive mixture and then adding a copper powder layer thereto and compacting the copper powder layer on the abrasive layer. The extrudate was co-cast at the above temperature and pressure. Hard zinc structures can be cut from the strip casting described above.

Example 4

A 100 mm diameter D6A2 (American Standards Association) abrasive stone of the type similar to Figure 2 was prepared and has the following composition by the method of Example 2 (using the polyimide of Example 2): Edge portion (resin bonded phase)

Polyimide - 39% by volume Copper - 36% by volume SiC - 25% by volume

Molded material - 52% by volume polyimide and 48% by volume copper.

Core part (metal bonded phase)

Copper - 100% by volume.

The resin and metal alloys were co-cast at a temperature of 450 ° C and a pressure of about 1750 kp / 2 cm to form an abrasive stone.

Example 5

A 150 mm diameter DiAl abrasive stone was prepared having the following composition when prepared according to Example 2 (using the polyimide of Example 2): 57889

Edge (resin-bound phase)

Polyimide - 63% by volume Diamonds - 25% by volume Nickel - 12% by volume

Material to be cast for diamond coating - 100% by volume of polyimide.

Core part (metal bonded phase)

Copper - 100% by volume

The resin and metal alloys were co-cast at 450 ° C and ca.

O

1876 kp / cm for the production of grinding stone.

Example 7

A 150 mm diameter DiAl abrasive stone was prepared having the following composition when prepared according to Example 2 (using the polyimide of Example 2):

Edge (resin-bound phase)

Polyimide - 33% by volume Copper - 30 - "-

SiC - 37

Cast material - 52% by volume and 48% by volume of copper.

Core part (metal bonded phase)

Aluminum - 100% by volume.

The resin and metal alloys were co-cast at a temperature of 450 ° C and a pressure of about 1090 kp / cm to produce an abrasive stone.

Example 8

3,150 mm diameter D1A1 abrasive stones having the following composition were prepared by the method of Example 2 (using the polyimide of Example 2)}, the composition of the edge portion of each stone being identical but the composition of the core portion being different:

Edge (resin-bound phase)

Polyimide - 35% by volume Copper - 30 SiC - 37

Molded material - 52% by volume polyimide and 48% by volume copper.

Core part (metal bonded phase)

stone number

1 28% by volume Cu and 72% by volume AI

2 37% by volume Cu and 63% by volume Al

3 50% by volume Cu and 50% by volume AI.

10 5 7 8 8 9

The resin alloys were co-cast at 450 ° C and using a pressure of about 1092 kp / cm to form an abrasive stone.

Example 9 a) An 88.9 mm diameter strip comprising the following composition was prepared by pre-pressing and co-casting a semicircular block of cast resin alloy with a similar block of semicircular cast metal compact.

Resin-bound phase

Polyimide - 33% by volume Copper - 30 - ”-

SiC - 37 - "-

Molded material - 52% by volume polyimide and 48% by volume copper.

Metal bonded phase

Copper - 100% by volume.

The strip was pre-pressed at 210 kp / cm 2 and co-cast at 450 ° C and using a pressure of about 2100 kp / cm. The bond between the resin-bonded phase and the metal-bonded phase was subjected to shear stress and the bond strength was found to average 459.5 kp / cm.

b) Very thin strips were machined from the interface between the resin-bonded phase and the metal-bonded phase from the strip structure described in (a). The strips were subjected to tensile analysis according to ASTM-D-1708 and the average tensile strength of the interface was found to be 374 x 5 kp / cm 2.

Claims (5)

11 57889 A grindstone product »comprising a) an organic hexached phase having from 100 to about 30 volumes of a substantially linear polyimide polymer material based on the molding material in said resin bonded phase and further up to about 70 volumes by volume of the metal based on the resin bonded phase. the phase also includes non-castable, abrasive particles, and h) a metal-bonded phase having from 100 to about 70 volumes of # metal based on the casting material in said resin-bonded phase and further up to about 30% by volume of substantially linear polyimide polymer material based on said metal-bonded phase; material, characterized in that the product is produced by co-casting a resin-bonded and a metal-bonded phase. A method of making a shaped structure for use as an abrasive stone according to claim 1 by combining a) an organic resin-bonded phase comprising a castable resin mixture of 100 to about 30 volumes of a substantially linear, fusible polyimide polymer powder based on said resin-bonded phase. 70 vol. # Of castable metal powder based on the casting material in the resin-bonded phase, wherein the resin-bonded phase also contains abrasive particles, and h) a metal-bonded phase comprising a castable alloy of 100 to about 70 by volume of # castable metal powder based on said metal-bonded phase. and in addition not more than about 30% by volume of a substantially linear, fusible polyimide polymer powder, based on the metal-bonded phase casting material, characterized in that said the organic resin-bonded phase and the metal-bonded phase are cast together by applying heat and pressure simultaneously to said castable mixtures. A method according to claim 2, characterized in that said co-casting comprises pre-sealing both the cast resin mixture and the cast metal alloy to form a pre-compression and that said pre-compression is then heated to a temperature of about 350 to about 500 ° C and then pressurized. about 280 to about 3,500 kp / cm, the treatment lasting sufficient time to cause both the molded resin mixture and the alloy to coalesce, and then the shaped structure thus formed is cooled. A method according to claim 3, characterized in that said cast resin mixture is first pre-compressed, after which the cast metal alloy is pre-compressed in contact with said pre-compressed cast resin mixture. Method according to one of Claims 2 to h, characterized in that the co-casting comprises filling a mold with a cylindrical core part with a substantially linear polyimide polymer and abrasive particles, sealing the polyimide polymer and abrasive particles, removing the cylindrical core part, removing the cylindrical core part, and compacting the cast alloy, heating the mold to a temperature of about 350 to about 500 ° C, followed by applying pressure to the mold at a pressure between about 280 and about 3,500 kp / cm, and cooling the mold. 57889