JP4619634B2 - Sliding material and manufacturing method of sliding material - Google Patents

Description

【００５３】
こうして実施例１〜３および比較例１，２でそれぞれ得られた硬化物を、１３０℃のオーブン中で１時間加熱・放置した後、外観を目視で観察したところ、実施例１〜３で得られた硬化物の表面には、ワックスのブリードが見られた。そして、手で触ったところ、潤滑性を有することが確かめられた。これに対して、比較例１および２で得られた硬化物の表面にはなんら変化がなく、潤滑性が認められなかった。
【００５４】
【発明の効果】
以上の記載から明らかなように、本発明によれば、基材への密着性が良好で形状変化に対する追随性が高く、所望の際に摩擦等により生じる熱により、しゅう動面に潤滑性の高い流体層を形成し、良好な潤滑性およびしゅう動性を発揮するしゅう動材を得ることができる。
【図面の簡単な説明】
【図１】本発明の一実施形態であるしゅう動材の構造を示す断面図。
【図２】実施形態のしゅう動材に圧力やせん断力が加えられた状態を示す断面図。
【図３】実施形態のしゅう動材にさらに圧力やせん断力が加えられたときの変化を示す拡大断面図。
【符号の説明】
１……しゅう動材、２……液状ゴムの硬化物、３……ワックス粒子、４……基材、６………流体潤滑層、７………ワックス粒子が抜け出た孔、８………破砕されたゴム粒状物[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sliding material and a manufacturing method of the sliding material, and more particularly, a sliding material that exhibits lubricity and sliding property by heating such as frictional heat under predetermined conditions when desired, and the like. The present invention relates to a method for manufacturing a sliding material.
[0002]
[Prior art]
Generally, the sliding surface of an object undergoes surface deformation, fusion or wear due to frictional heat. Therefore, in order to protect the sliding surface, a lubricating component such as oil or grease is applied. However, since these lubricating components are fluids, stickiness and dirt are generated due to outflow.
[0003]
In the field of metal processing, a lubricating coating film in which a lubricating component is held in a binder layer is formed on a sliding surface. However, in this method, since the coating film thickness is thin, the amount of the lubricating component held is small, and the lubricity may be insufficient.
[0004]
In addition, a proposal has been made to form a sliding layer that is thicker than the coating film by incorporating a lubricating component into the coating layer made of a molding resin. However, in this proposal, since the resin as the base component has rigidity, the followability to the substrate is poor and the adhesion to the shape is not sufficient.
[0005]
In order to improve the followability to the base material and the adaptability of the shape, a sliding material in which a lubricating component is blended with various rubber materials has been proposed. However, such a rubber-based sliding material has an advantage that it is rich in resilience and has good sealing properties, but has a disadvantage of high frictional resistance. Further, when a solid lubricant is blended as a lubricating component, the lubricity is not sufficient, and when a large amount is blended to improve the lubricity, there is a problem that the physical properties of rubber are remarkably lowered. A method of chemically treating the surface of the rubber layer to improve the sliding property is also conceivable. However, this method cannot obtain a sufficient effect because the modified layer is thin and easily worn.
[0006]
Further, as a rubber material for sealing metal / rubber surfaces of pneumatic equipment and hydraulic equipment, a sliding material is proposed in which a lubricating layer is formed on the surface of the base rubber layer and an inner layer containing a bleed lubricant is provided. Yes. (For example, see Patent Document 1)
[0007]
[Patent Document 1]
JP 2000-240805 A (second page)
[0008]
[Problems to be solved by the invention]
However, the sliding material described in Patent Document 1 has a problem in that it is difficult to adjust the bleed amount, and sufficient lubricity and sliding properties cannot be exhibited when desired.
[0009]
An object of the present invention is to provide a sliding material that eliminates the difficulty of the frictional resistance of a rubber material and that can exhibit sufficient lubricity and exhibit sliding properties when desired.
[0010]
[Means for Solving the Problems]
The sliding material of the present invention includes an alkyl-modified polyorganosiloxane, candelilla wax, carnauba wax, rice wax, wax, jojoba oil, beeswax, lanolin, montan wax in a cured product of an addition reaction curable liquid silicone rubber. And derivatives thereof, ozokerite, ceresin, paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, petrolactam, Fischer Tropu wax, hydrogenated castor oil and derivatives thereof, hydrogenated soybean oil, hydrogenated rapeseed oil, hydrogenated palm oil , 12-hydroxy stearate, stearic acid amide, phthalic anhydride imide is selected from stearic acid esters consist wax having the liquid silicone rubber and compatibility and melting point of the reactive without 50 to 140 ° C., 0.5 to 40 solid particles having a particle size of m are contained in a proportion of 5 to 70 parts by weight with respect to 100 parts by weight of the cured product, and the wax is melted by frictional heat generated on the sliding surface. It is configured to bleed on the surface of the cured product.
[0012]
The sliding material manufacturing method of the present invention is the above-described sliding material manufacturing method, in which the solid particles of the wax (B) are added to the (A) addition reaction curable liquid silicone rubber. Adding and mixing at a temperature below the melting point, applying the rubber composition obtained by the mixing to the sliding surface at a temperature below the melting point of the wax, and heating the coating layer of the rubber composition And applying the rubber composition so that the base rubber is sufficiently cured before the wax in the rubber composition melts and bleeds to the surface. The layer is heated .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0015]
The rubber composition for a sliding material according to the first embodiment of the present invention comprises (A) a curable liquid rubber, (B) a melting point not lower than room temperature, and compatibility and reactivity with the liquid rubber. It is made up of non-wax particles dispersed.
[0016]
The curable liquid base rubber of the component (A) used in the present invention may be any material as long as it is liquid at room temperature and cured by heating or at room temperature to form a cured product having rubber-like elasticity. The type of curing is not particularly limited, but it is desirable to use an addition reaction curing type or condensation reaction curing type liquid silicone rubber (polyorganosiloxane).
[0017]
Examples of the addition reaction curable polyorganosiloxane include (a) a polyorganosiloxane containing an alkenyl group, (b) a polyorganohydrogensiloxane containing a hydrogen atom bonded to a silicon atom, and (c) a reinforcing silica. A liquid silicone rubber composition containing powder and (d) cured with a platinum-based catalyst can be used.
[0018]
The composition will be described in more detail. In the alkenyl group-containing polyorganosiloxane (a), examples of the alkenyl group include a vinyl group, an allyl group, and a propenyl group. Examples of organic groups other than alkenyl groups include alkyl groups such as methyl, ethyl and propyl; aryl groups such as phenyl and tolyl groups; 3,3,3-trifluoropropyl groups and 3-chloro. Examples thereof include substituted alkyl groups such as propyl group.
[0019]
The molecular structure of component (a) may be either linear or branched. The molecular weight is not particularly limited, but a linear diorganopolysiloxane having a viscosity at 25 ° C. of 100 to 5,000,000 mPa · s (cP) is preferable.
[0020]
The polyorganohydrogensiloxane of component (b) is a component for crosslinking the component (a). As an organic group other than a hydrogen atom bonded to a silicon atom, an alkyl group such as a methyl group, an ethyl group, or a propyl group; an aryl group such as a phenyl group or a tolyl group; 3, 3, 3-trifluoropropyl group, 3 -It can have a substituted alkyl group such as a chloropropyl group. The molecular structure of the component (b) may be any of linear, branched linear, cyclic, and network.
[0021]
The blending amount of component (b) is such that the molar ratio of silicon atom-bonded hydrogen atoms in this component to silicon atom-bonded alkenyl groups in component (a) is (0.5: 1) to (20: 1). And preferably in the range of (1: 1) to (5: 1). When this molar ratio is less than 0.5, good curability cannot be obtained, and good mechanical strength cannot be obtained. On the other hand, when the molar ratio is larger than 20, the heat resistance is remarkably deteriorated.
[0022]
Examples of the reinforcing silica powder as component (c) include fumed silica, wet silica, fused silica and the like, and one or more of them may be used in combination. The compounding quantity of a silica powder shall be 1.0-200 weight part with respect to 100 weight part of (a) component, More preferably, you may be 3.0-50 weight part. When the amount of silica powder is less than 1.0 part by weight, the resulting cured product has insufficient mechanical strength, and when it exceeds 200 parts by weight, mixing becomes difficult.
[0023]
The platinum-based catalyst of component (d) is a catalyst for curing the polyorganosiloxane composition comprising the components (a) to (c). For example, platinum fine powder, platinum black, chloroplatinic acid, tetrachloride Examples include platinum, an olefin complex of chloroplatinic acid, an alcohol solution of chloroplatinic acid, a complex compound of chloroplatinic acid and alkenylsiloxane, a rhodium compound, and a palladium compound.
[0024]
The addition amount of the platinum-based catalyst is preferably 0.1 to 1,000 ppm by weight as platinum-based metal with respect to the polyorganosiloxane of component (a). A particularly preferred range is 1 to 500 ppm. When the addition amount of the platinum-based catalyst is less than 0.1 ppm, the addition reaction does not proceed sufficiently, and when it exceeds 1000 ppm, further progress of the reaction is not recognized, which is uneconomical.
[0025]
The condensation reaction curable polyorganosiloxane includes (e) a polyorganosiloxane having a hydroxyl group at both ends, or a polyorganosiloxane having a hydrolyzable silyl group, (f) a crosslinking agent, and (g) a reinforcing property. A liquid silicone rubber composition containing silica powder and cured by (h) a curing catalyst can be used.
[0026]
In the polyorganosiloxane of component (e), examples of the hydrolyzable organic group bonded to the silicon atom include alkoxy groups such as methoxy group, ethoxy group, propoxy group, and butoxy group; 2-methoxyethoxy group, 2-ethoxy Examples include substituted alkoxy groups such as ethoxy groups; enoxy groups such as isopropenoxy groups. Examples of groups other than hydrolyzable groups include alkyl groups such as methyl group, ethyl group, and propyl group; aryl groups such as phenyl group and tolyl group; 3, 3, 3-trifluoropropyl group, 3- Examples thereof include substituted alkyl groups such as chloropropyl group.
[0027]
(F) As a crosslinking agent, tetramethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, tetrapropoxysilane, Alkoxy group-containing compounds such as tetraisopropoxysilane and partial hydrolysis condensates thereof; tetrakis (2-ethoxyethoxy) silane, methyltris (2-methoxyethoxy) silane, vinyl (2-ethoxyethoxy) silane, phenyltris ( Substituted alkoxy group-containing compounds such as 2-methoxyethoxy) silane and partial hydrolysis condensates thereof; methyltriisopropenoxysilane, vinyltriisopropenoxysilane, phenyltriisopropene Kishishiran, dimethyl isopropenoxysilane silane, such as an enoxy group-containing compounds such as methyl vinyl di- isopropenoxysilane silane and their partially hydrolyzed condensates are exemplified.
[0028]
Examples of the reinforcing silica powder as the component (g) include the same silica powder used in the addition reaction curable polyorganosiloxane.
[0029]
(H) Component curing catalysts include iron octoate, cobalt octoate, manganese octoate, tin naphthate, tin oleate and carboxylic acid metal salts; dimethyltin diolate, dimethyltin dilaurate, dibutyltin diacetate, dibutyltin oleate, diphenyltin Organotin compounds such as diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis (triethoxysiloxy) tin, dioctyltin dilaurate; tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, 1,3-propoxytitanium bis (ethylacetylacetate) ) Alkoxy titanium such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum Examples include organic aluminum compounds such as umethyl acetoacetate and triethoxyaluminum; organic zirconium compounds such as zirconium tetraacetylacetonate, tetraisopropoxyzirconium tetrabutoxyzirconium, tributoxyzirconium acetylacetonate, and tributoxyzirconium stearate. 0030]
As the curable liquid base rubber of component (A), in addition to the above addition reaction curable liquid silicone rubber and condensation reaction curable liquid silicone rubber, alkenyl group-containing polyorganosiloxane and reinforcing silica powder Benzoylperoxide, 2,4-dichlorobenzoylperoxide, dicumylperoxide, cumyl-t-butylperoxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, di- It is also possible to use an organic peroxide curable silicone rubber composition that is cured with an organic peroxide such as t-butylperoxide to form a silicone rubber.
[0031]
The component (B) wax particles used in the present invention are characteristic of the rubber composition for sliding materials of the present invention, and have a melting point of normal temperature or higher, more preferably 50 to 140 ° C. And a wax that is not compatible or reactive with the component (A).
[0032]
As such a wax, for example, an alkyl-modified polyorganosiloxane having a melting point in the above-described range or a plant-based, animal-based, or mineral-based wax described below can be used. In the present invention, the term “wax” indicates not only a narrowly defined wax of fatty acid and mono- or divalent higher alcohol ester, but also a liquid having a relatively low viscosity that is solid at room temperature and melts by heating. A liquid lubricant.
[0033]
As waxes that can be used, candelilla wax, carnauba wax, rice wax, beeswax, jojoba oil, beeswax animal wax, lanolin, montan wax mineral mineral wax, ozokerite, ceresin, Petroleum wax, paracrystalline wax, microcrystalline wax, petrolactam, and synthetic wax include synthetic hydrocarbon-based Fischer-Tropsch wax, polyethylene wax, modified wax, montan wax derivative, paraffin wax derivative, microcrystalline wax derivative , Polyethylene wax derivatives, hydrogenated wax hydrogenated castor oil, hydrogenated soybean oil, hydrogenated rapeseed oil, hydrogenated palm oil, and hydrogenated castor oil derivatives, fatty acid-based 12- Loki system Alin acid, stearic acid amide, may be mentioned phthalic anhydride imide, stearic acid esters and the like.
[0034]
The particle size of such wax particles is preferably 0.5 to 40 mm, more preferably 5 to 20 mm. When the particle size is less than 0.5 mm, not only is it difficult to produce industrially and the cost is high, but also the cured product cannot exhibit a sufficient sliding effect. On the other hand, when the particle size of the wax particles exceeds 40 mm, the mechanical strength (rubber physical properties) of the composition and the cured product is remarkably lowered, which is not preferable. Further, the maximum particle size is 100% or less of the coating thickness obtained by applying the composition. When the maximum particle size exceeds 100% of the coating thickness, the appearance of the coating is deteriorated.
[0035]
As a method of obtaining wax particles having such a particle size, for example, a method in which a wax melted by heating is put in a desired mold, and a wax heated / melted in a cooled fluid There are a method of forming by dropping and dispersing while stirring and further adjusting the particle size with a dispersing machine such as a sand mill, or a method of further crushing or pulverizing a wax-shaped product to a desired particle size.
[0036]
The blending amount of the wax particles as the component (B) is 5 to 70 parts by weight, more preferably 30 to 50 parts with respect to 100 parts by weight of the liquid polyorganosiloxane of the component (A). If the blending amount of the wax particles is less than 5 parts by weight, the cured product cannot sufficiently function as a sliding material. On the other hand, when the amount is more than 70 parts by weight, the effect of imparting slidability to the blending amount is small, and on the contrary, the mechanical properties and heat resistance of the cured product are greatly deteriorated.
[0037]
The rubber composition for a sliding material of the present invention can be obtained by adding the component (B) to the component (A) and stirring and mixing. At this time, in order to prevent melting of the wax which is the component (B), it is added and mixed at a temperature below the melting point of the wax. Moreover, in the composition obtained, (B) wax particles do not necessarily have to be uniformly dispersed in (A) liquid polyorganosiloxane, so mixing of (A) component and (B) component is uniform. There is no need to do it.
[0038]
A non-bleeding solid lubricant can be added to the sliding rubber composition of the present invention. As the solid lubricant, for example, graphite powder, PTFE powder, molybdenum disulfide powder, silicone resin powder and the like can be used.
[0039]
Furthermore, hardened rubber particles having a higher hardness than the hardened liquid silicone rubber can be used. Examples of such rubber particles include vulcanized natural rubber, styrene / butadiene rubber (SBR), styrene / isoprene rubber, acrylonitrile / butadiene rubber (NR, NBR), polybutadiene rubber, polyisoprene rubber, polychloroprene rubber, and polyisobutylene rubber. , Butyl rubber, Halogenated butyl rubber, Cyclized rubber, Alphine rubber, Ethylene / vinyl acetate copolymer rubber (EVA), Vinyl chloride / Acrylic copolymer rubber, Chlorinated polyethylene, Chlorosulfonated polyethylene, Ethylene / propylene rubber (EPR) ), Ethylene / propylene / diene copolymer rubber (EPDM), EPT rubber, polyurethane rubber and various modified products thereof, for example, polymethylmethacrylate graft copolymer and the like can also be used.
[0040]
Furthermore, as other components, inorganic fillers such as titanium oxide, iron oxide, calcium carbonate and magnesium carbonate; pigments such as carbon black and bengara; heat resistance improvers, reaction control agents, mold release agents, plasticizers, Sensitizers, polymerization inhibitors, adhesion improvers and the like can be blended.
[0041]
Next, the sliding material which is the 2nd Embodiment of this invention is demonstrated.
[0042]
In FIG. 1, reference numeral 1 indicates a sliding material. This sliding material 1 is made of a wax having a melting point not lower than room temperature and not compatible with or reactive with the liquid rubber in a cured liquid rubber 2. It has a structure in which the particles 3 are dispersed. As the liquid rubber and wax particles, the same materials as those described in the embodiment of the rubber composition for a sliding material can be used. In addition, the code | symbol 4 shows the base material with which the sliding material 1 is attached, 5 shows a primer layer. As the primer, for example, room temperature curable liquid silicone rubber can be used. In the sliding material of the embodiment, a thin layer that can be easily broken may be provided on the sliding surface of the liquid rubber cured product 2. This thin layer is easily broken when pressure or shearing force is applied to the sliding material, and is formed so as not to prevent the wax from bleeding from the inside of the cured rubber.
[0043]
In order to produce this sliding material, the above-mentioned rubber composition for sliding material is potted or coated on a required portion (sliding surface) of the base material 4 through the primer layer 5, and this potting or The coated layer is heated to cure. In the heat-curing process, the wax particles in the potted or coated rubber composition are melted and the base rubber is sufficiently cured before the molten material bleeds and oozes out on the rubber surface. In addition, it is desirable to adjust conditions such as the heating rate.
[0044]
When pressure or shear force is applied to the sliding material of the present invention, frictional heat is generated on the surface (sliding surface) to which pressure or shear force is applied, and the wax melted by the heat is as shown in FIG. The fluid lubrication layer 6 that bleeds on the surface of the cured liquid rubber 2 and has excellent lubricity is formed. As a result, good lubricity and sliding properties can be exhibited. In the figure, reference numeral 7 denotes a hole through which the wax particles have escaped.
[0045]
Further, when a large or long-term pressure or shear force is applied, as shown in FIG. 3, the liquid rubber cured product 2 is crushed by the holes 7 from which the wax particles are removed as a trigger. The periphery of the crushed rubber particles 8 is covered with the fluid lubrication layer 6. The granular material (diameter 2 mm or more) covered with the fluid lubrication layer 6 is easy to roll and exhibits good lubricity in the rolling state.
[0046]
The sliding material of the present invention has good adhesion to the base material and high followability to shape change, and forms a fluid layer with high lubricity on the sliding surface by heat generated by friction when desired, Good lubricity and sliding performance. Therefore, the application is not particularly limited, and it can be widely used in various applications that require sliding properties.
[0047]
Next, examples of the present invention will be described.
[0048]
Example 1
Addition reaction curable liquid silicone rubber LSR2640 (trade name of GE Toshiba Silicone Co., Ltd.) and 100 parts by weight of an alkyl-modified polyorganosiloxane SF1642 (manufactured by GE Toshiba Silicone Co., Ltd .; melting point of about 70 ° C.) 30 parts by weight of a particle size of 5 mm) was added and dispersed by stirring and mixing at room temperature. The viscosity of this composition was 6,400,000 mPa · s at 25 ° C. The SF1642 particles need not have the same particle diameter, and the dispersion of the SF1642 particles in the liquid silicone rubber may be inhomogeneous.
[0049]
Next, the curable polyorganosiloxane composition thus obtained was applied on the template with a spatula so as to have a thickness of 2 cm, and then heated at a temperature of 130 ° C. for 1 hour to cure the liquid silicone rubber. I let you.
[0050]
Examples 2 and 3
A curable polyorganosiloxane composition was prepared in the same manner as in Example 1 except that wax particles having the melting points and particle sizes shown in Table 1 were blended in the composition shown in the same table, and this composition was used. A cured product was produced in the same manner as in Example 1. Note that paraffin wax-155 and HI-Mic-1090 shown in Table 1 are trade names of Nippon Seiwa Co., Ltd.
[0051]
Moreover, as Comparative Example 1, 30 parts by weight of silicone oil TSF4421 (trade name of GE Toshiba Silicone Co., Ltd.) having a melting point of room temperature or lower was added to 100 parts by weight of LSR2640, and the resulting mixture was heated and kneaded. A cured product was produced using the polyorganosiloxane composition. Furthermore, as Comparative Example 2, 30 parts by weight of SF1642 was heated and kneaded with 100 parts by weight of LSR2640, and a cured product was produced using the polyorganosiloxane composition thus obtained.
[0052]
[Table 1]

[0053]
The cured products obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were heated and left in an oven at 130 ° C. for 1 hour, and then visually observed for appearance. Wax bleed was observed on the surface of the cured product. And when it touched with the hand, it was confirmed that it has lubricity. On the other hand, there was no change on the surface of the cured products obtained in Comparative Examples 1 and 2, and no lubricity was observed.
[0054]
【The invention's effect】
As is clear from the above description , according to the present invention, the adhesion to the base material is good and the followability to the shape change is high, and the sliding surface is lubricated by heat generated by friction or the like when desired. A sliding material that forms a high fluid layer and exhibits good lubricity and sliding properties can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a structure of a sliding material according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a state in which pressure or shear force is applied to the sliding material of the embodiment.
FIG. 3 is an enlarged cross-sectional view showing changes when pressure or shear force is further applied to the sliding material of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sliding material, 2 ... Hardened | cured material of liquid rubber, 3 ... Wax particle, 4 ... Base material, 6 ......... Fluid lubrication layer, 7 ...... The hole from which the wax particle escaped, 8 ... ... crushed rubber granules

Claims (2)

In the cured product of addition reaction curable liquid silicone rubber, alkyl-modified polyorganosiloxane, candelilla wax, carnauba wax, rice wax, wax, jojoba oil, beeswax, lanolin, montan wax and derivatives thereof, ozokerite, ceresin, Paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, petrolactam, Fischer-Tropsch wax, hydrogenated castor oil and derivatives thereof, hydrogenated soybean oil, hydrogenated rapeseed oil, hydrogenated palm oil , 12-hydroxystearic acid, stearamide, anhydrous phthalic acid imide, selected from stearic acid esters consist wax having the liquid silicone rubber and compatibility and melting point of 50 to 140 ° C. without reactive solid with a particle size of 0.5~40mm Child, are contained is distributed at a ratio of 5 to 70 parts by weight based on the cured product 100 parts by weight,
A sliding material characterized in that the wax is melted by frictional heat generated on the sliding surface and bleeds onto the surface of the cured product. It is a manufacturing method of the sliding material of Claim 1,
In the (A) addition reaction curable liquid silicone rubber, the solid particles of the (B) wax are added and mixed at a temperature not higher than the melting point of the wax; and
Applying the rubber composition obtained by the mixing to the sliding surface at a temperature not higher than the melting point of the wax;
A step of heating and curing the coating layer of the rubber composition;
In the heating and curing step, the coating layer of the rubber composition is heated so that the base rubber is sufficiently cured before the wax in the rubber composition melts and bleeds to the surface. A manufacturing method of sliding material.

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