JPS63457B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of manufacturing a synthetic resin multilayer sliding material suitable for use in bearings, sliding plates, retainers, etc. Hitherto, as a means of improving the wear resistance and load resistance of thermoplastic synthetic resin sliding members, multi-layer sliding members have been known in which a thin layer of thermoplastic synthetic resin is applied to a metal backing. ing. In sliding members with such a multi-layer structure, even if the synthetic resin is relatively soft, if it is applied as a thin layer on a backing metal such as steel, the resin itself may bend or sag. As a result, the wear resistance and load resistance of the sliding member are improved. Furthermore, since the resin layer is thin, the frictional heat generated on the sliding surface is easily transmitted to the back metal, and is dissipated from the sliding member, thereby suppressing the temperature rise, further promoting the above-mentioned performance improvement. In addition, since it is resistant to expansion and contraction of the resin or deformation over time, the dimensional stability of the sliding member is significantly improved. In this way, synthetic resin sliding members with a multi-layer structure can greatly improve the drawbacks of synthetic resin while taking advantage of its properties, but even so, under severe friction conditions, the resin layer melts and flows on the sliding surface. There are still problems such as peeling off from the backing metal. Such problems can no longer be solved simply by using multiple layers of synthetic resin. As a result of intensive research into these problems, the inventors of the present invention made use of the frictional and abrasion properties of synthetic resins, and at the same time improved their resistance to heat and improved their adhesion to backing metals such as steel. As a multi-layer sliding member that can be effectively used under the sun, we have developed the patent application No. 54-45427 ``Synthetic resin multi-layer sliding member''. This product consists of a composition consisting of 4 to 25% by weight of thermosetting polyimide resin, 5 to 15% by weight of tetrafluoroethylene resin (PTFE), 2 to 15% by weight of lubricating oil, and the balance thermoplastic resin. Regarding the synthetic resin multilayer sliding material formed by integrally depositing the resin composition, several effective methods have been disclosed as means for depositing the resin composition on the metal backing. That is, a pretreated backing metal is heated, a powder of the resin composition is sprinkled onto it and melted on the backing metal, and the molten layer is pressed by a pressure plate or by a pressing operation. This is a method in which the desired multi-layer sliding member is obtained by holding it for a predetermined period of time without applying it, and then cooling it. The second method, which is relatively suitable for mass production, uses a continuous strip that has been coiled into a hoop material and has been pretreated as a backing metal, and this is attached to a crosshead that is attached to an extrusion molding machine. In this method, the resin composition is supplied to a die, melted, and extruded from a nozzle, so that the resin is continuously and integrally adhered to the surface of the backing metal. The third method, like the second method, uses a continuous strip that is coiled and provided as a hoop material as a backing metal and is pretreated in the same way. The strip is fed at a predetermined speed with or without heating, and the resin composition powder is sprinkled onto the backing metal to melt it, and the adhered layer of the resin is formed under roll pressure. The method is to let it form. Here, pretreatment refers to metal plating in advance on the back metal surface, or a sintered metal porous layer provided thereon without metal plating, or roughening of the surface as appropriate by shotplast or acid treatment. Alternatively, the surface treated in this way is cleaned and then a synthetic resin primer is baked on. As a result of further research and development, the present inventors found that there is no problem when adopting the second and third methods using the composition related to the above-mentioned Japanese Patent Application No. 45427-1982. It has been found that, in the first method, problems often occur, especially when obtaining a flexible layer sliding material without applying a pressing operation to the composition resin layer. In other words, when trying to efficiently obtain a multilayer sliding material on a mass production scale, it is impossible to rapidly raise the temperature of the backing metal or the atmosphere unless a pressing operation is performed, and the heating and holding time required for adhesion is difficult. It is difficult to shorten the length, and the fluidity of the molten resin is poor. If you ignore these points and proceed with the adhesion process, the resin compositions will not be fused together uniformly, and the adhesion layer will not only become very rough, but also the bond between the adhesion layer and the underlying metal will become uneven. Adhesion also decreases. Therefore, the present inventors have attempted to efficiently obtain a desired multilayer sliding material on a mass production scale without having as much adverse effect on various properties as a sliding material and without applying any pressing operation to the molten resin layer. As a result of intensive research on this method, it was discovered that this can be achieved by reducing the blending amounts of both the thermosetting polyimide resin component and the PTFE component without changing the blending amount of the lubricant component. That is, 76 to 96% by weight of thermoplastic synthetic resin powder selected from polyacetal resin, polyamide resin, polycarbonate resin, polyolefin resin, polyethylene terephthalate resin, and polybutylene terephthalate resin, and 1.5 to less than 4% of thermosetting polyimide resin powder. % by weight, 0.5 to less than 5% by weight of tetrafluoroethylene resin powder, and 2 to 15% by weight of a lubricant, and these are mixed uniformly to obtain a synthetic resin composition having powder fluidity, and then the synthesis The resin composition was uniformly dispersed and supplied onto the metal backing metal and melted on the backing metal, thereby making it possible to integrally form a resin layer made of the composition on the backing metal. This invention is particularly suitable when using a metal backing metal with a synthetic resin primer baked on as a pretreatment, and moreover, it can be efficiently replicated without pressing the molten resin layer when forming the resin composition. A layered sliding material can be obtained. The polyimide resin used in this invention is a polymerization product obtained by addition-polymerizing Bismaleimide A with an addition reaction product B of isocyanuric acid and butyl glycidyl ether, such as Imidalloy, a trade name manufactured by Toshiba Chemical Corporation, or Maleimide A
and alkylene diamide B, such as a thermosetting polyimide resin such as Kinel (trade name, manufactured by Rhone-Poulenc). These polyimide resins generally have features such as good heat resistance, excellent adhesion and very little decrease in adhesive strength even at high temperatures, excellent dimensional stability, and good friction and wear properties. It is something. The amount of polyimide resin component in the composition is
The amount is preferably 1.5 to 4% by weight, and an uncured powder that passes through approximately 200 meshes is used. The polyimide resin component has the effect of increasing the hardness of the composition, improving the adhesive strength to the backing metal, and suppressing the fluidity of the applied resin composition, thereby preventing peeling and settling of the resin layer. It also contributes to improving wear resistance and load carrying capacity. Note that this polyimide resin is cured (addition polymerization)
In the process of drying, moisture and other volatile substances are not generated, and since this material itself has extremely low hygroscopicity, there is no risk of creating bubbles or cracks in the resin layer formed. In this invention, if the amount is less than 1.5% by weight, almost no effect can be expected, and if it is more than 4% by weight, the fusion of the formed resin layer becomes uneven and rough, which not only impairs toughness. It impairs adhesion workability. PTFE is blended in the form of fine powder in an amount of 0.5 to 5% by weight. If it is more than 5% by weight, the fusion of the resin layer becomes uneven and rough, similar to the polyimide resin component, which not only impairs the toughness of the resin layer but also impairs the workability of adhesion. If it is less than 0.5% by weight, the synergistic effect with the lubricating oil component to impart self-lubricating properties cannot be expected. Lubricants include mineral oils such as engine oil, animal and vegetable oils such as whale oil and castor oil, and synthetic lubricants such as silicone oil, which are liquid at room temperature, petroleum waxes such as paraffin, and animal and vegetable waxes such as higher fatty acids and their esters. and soap, which are solid at room temperature but become liquid at temperatures up to the resin layer forming temperature of the composition. The blending amount is preferably 2 to 15% by weight, particularly 5 to 10% by weight. These lubricants provide the composition with excellent self-lubricating properties and contribute to lowering the coefficient of friction, especially at relatively high sliding speeds. Therefore, the generation of frictional heat is reduced, and as a side effect, wear resistance and load resistance are improved. When the amount is less than 2% by weight, almost no effect is observed, and as the amount is increased, the lubricating effect increases, but on the other hand, it not only reduces the mechanical strength but also reduces the adhesion of the resin layer. Since it also has a negative effect on adhesion strength, the upper limit was set at 15% by weight. In addition to the above-mentioned lubricants, powders of graphite, molybdenum disulfide, lead oxide, boron nitride, and other soft metals, which are conventionally generally used as solid lubricants, can also be blended as needed. The thermoplastic synthetic resin used in this invention can be normally molded at the curing temperature of polyimide resin, that is, the temperature at which addition polymerization proceeds smoothly, from 200 to 280°C, and the resin itself has good properties. It is necessary to have friction and wear characteristics and considerable mechanical strength. Thermoplastic synthetic resins having such features include those listed in Table 1. The synthetic resin composition used in this invention is a powdered polyimide resin initial polymer (for example,
The cure time on the hot plate is 40 to 60 seconds),
It is obtained by stirring and mixing predetermined amounts of PTFE powder, thermoplastic synthetic resin powder, and lubricant at room temperature or in a slightly warmed state.

【table】

[Table] Stirring and mixing means using a high speed mixer, such as a Henschel mixer, are effective for obtaining the composition of the present invention. It is necessary that the obtained composition has powder fluidity. The back metal used in this invention is preferably a general structural rolled steel plate, but depending on the intended use, other rolled steel plates or metal plates other than steel (aluminum,
Copper and their alloys) can also be used. Various pretreatments are performed on the surface of the backing metal, but in the present invention, it is desirable to use the area where the synthetic resin primer has been baked as the adhesion surface, as described above. The types of primers include synthetic resins such as phenol-modified alkyd resins, polyamideimide resins, epoxy resins, furan resins, polyester resins, and polyurethane resins, and for coating resin layers mainly composed of polyolefins, especially tetraisopropyl titanate. The thickness of these primer layers is approximately 0.005 to 0.030 mm (5 microns to
30 microns) is desirable. A powdered resin composition is supplied onto the backing metal that has been pretreated in this way, and is fused at a temperature of 200 to 280°C. At this time, when forming a relatively thick resin adhesion layer, if necessary, the powdered resin composition layer supplied by a bar or roll may be lightened to flatten the surface layer (although pressure may be applied). (no operation required) can be taken. Further, the back metal may be heated to a predetermined temperature in advance before supplying the resin composition, or may be heated after the composition is supplied and sprayed. In either case, it is desirable that the resin be fused by heat transfer from the backing metal.For example, if the ambient temperature is too high, there are no conditions where the supplied and dispersed composition powder starts to melt from its surface layer. Undesirable. The time required for fusion bonding is as shown in Table 2, illustrating the case where the thickness of the resin layer is 0.5 mm.

[Table] The thickness of the resin layer deposited according to the present invention is approximately 0.1 to 2.5 mm, and if it is thinner than 0.1 mm, pinholes will occur frequently, which is not good. If the thickness is 2.5 mm or more, not only will the time required for fusion be excessive, but the homogeneity of the adhered layer will be impaired, and there will also be problems such as cracking in the adhered layer. In addition, if the composition contains a large amount of lubricant components, for example, if 10% by weight or more of engine oil is blended and there is concern about the adhesion of the adhered layer, only the thermoplastic synthetic resin that makes up the main component of the composition may be used. By applying a thin layer of the composition to a pretreated back metal, and then spraying and applying the composition thereon, the adhesive property can be ensured and the adhesive strength can be increased. Examples will be described below. Example Cure time on a hot plate at 200℃ is 40 to 60
2% by weight of polyimide resin powder (manufactured by Toshiba Chemical Co., Ltd., trade name Imidalloy), 1% by weight of PTFE powder (PTFE Fine Powder, made by Mitsui Fluorochemicals Co., Ltd.), engine oil equivalent to SAE No. 30 (trade name Swamatsu, made by Maruzen Oil Co., Ltd.) HD) 6% by weight, molybdenum disulfide powder 1% by weight, and the remainder polyamide resin (Nylon 12 manufactured by Daicel, trade name Diamid)
Each powder component was stirred and mixed using a high-speed mixer to obtain a powdered resin composition. Next, after shot blasting (full coverage state) a general structural rolled steel plate, it is washed and degreased with a solvent, and then a phenol-modified alkyd resin primer is applied to the surface, and the thickness is 0.03 to 0.05 mm at a temperature of 250 to 300°C. Baked to a thickness of . The above-mentioned powdered resin composition was sprayed onto the pretreated back metal, and heated at 215 to 230°C while keeping the thickness of the supplied powder constant and the surface flattened.
The mixture was held in an electric furnace at a temperature of 80 seconds and then cooled to obtain a multilayer sliding material having a resin adhesion layer with a thickness of 0.3 to 0.4 mm. Example In the example, powdered nylon 6 was used instead of nylon 12, held in an electric furnace at a temperature of 220 to 240°C for 80 seconds, and then cooled to form a resin adhesion layer with a thickness of 0.3 to 0.4 mm. A multilayer sliding material having the following properties was obtained. Regarding the multi-layered fatty moving material obtained in this way,
A peel test was conducted in accordance with JIS K6744, and a compression shear test was conducted in accordance with JIS K6804.
Kg/20mm, values of 230-260Kg/ ^cm2 were obtained. These values are for 12 nylon and 6 nylon alone, i.e. 15~16Kg/20mm, 270~300
Even when compared to Kg/ ^cm2 , the decrease is only about 15-20%, and it has extremely high strength for a resin composition containing 6% by weight of lubricating oil.
There is no problem in practical use. Bearing performance such as friction coefficient and wear amount was measured using a Suzuki thrust tester at a sliding speed of 33.3 m/min.
As a result of a 10-hour test at a load of 30Kg/cm ² and an ambient temperature of 60℃ without lubrication, the coefficient of friction was 0.06 to 0.10, and the amount of wear was 0.01.
It was less than mm. Compared to the values for 12 nylon and 6 nylon alone, the friction coefficient is 1/6 to 1/2, and the amount of wear is so high that it is difficult to compare numerical values (numerical values).
(less than 1/100) performance has improved. As explained above, the method for manufacturing a synthetic resin multilayer sliding material according to the present invention can efficiently provide an extremely excellent sliding material.

Claims (1)

[Claims] 1 76 to 96% by weight of thermoplastic synthetic resin powder selected from polyacetal resin, polyamide resin, polycarbonate resin, polyolefin resin, polyethylene terephthalate resin, and polybutylene terephthalate resin, and 1.5 to less than 4% by weight of thermosetting polyimide resin powder %, 0.5% to less than 5% by weight of tetrafluoroethylene resin powder, and 2 to 15% by weight of a lubricant, and these are mixed uniformly to obtain a synthetic resin composition having powder fluidity, and then the synthetic resin A synthetic resin multi-layer sliding device characterized in that a composition is uniformly dispersed and supplied onto a metal backing metal, melting it on the backing metal, and integrally forming a resin layer made of the composition on the backing metal. Method of manufacturing wood.