JP2012031383A - Silicone resin composition and steering apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problem: though grease is coated as a countermeasure against the noise of the friction parts of a bracket 17, a column tube 12 and a support shaft 38 of a steering apparatus, the grease disappears from the friction faces by scattering or outflow during its use, and further, when backlash among the respective parts increases by wear, plastic deformation or the like of the respective parts, abnormal noise is caused.SOLUTION: The silicone resin composition for coating comprises: silicone oil having a viscosity of ≤3,000 mm/S; and silica of 30 wt.%, and has a friction coefficient of 0.4 to 0.5. The steering apparatus uses components using the same.

Description

  The present invention relates to a silicone resin composition as a coating film and a steering device using a component using the same.

  When fixing the steering column to the vehicle body, the friction between the brackets, column tubes, and spindles, which are component parts, can be tilted smoothly, and between parts due to wear or plastic deformation of parts. Grease is coated as a lubricant to prevent rattling.

  In Patent Document 1, a lubrication and stick-slip resistance is improved by a conventional solid lubricant film, and a low friction coating film is implemented. However, a lubricant grease is used in combination for wear resistance and durability. Has been.

  In Patent Document 2, durability is improved with a high-viscosity lubricant grease as a countermeasure against lubricant, but durability due to leakage due to startability at low temperatures and fluidity of grease at high temperatures. The problem remains.

JP 2009-114527 A JP 2007-238767 A

  Grease is coated as a countermeasure against noise caused by stick-slip generated at the friction part (shaft support) between the tube and tilt support shaft in the bracket of the steering device. However, if the grease disappears from the friction surface due to splashing or spilling while it is being used, and if rattling between parts increases due to wear or plastic deformation of parts, abnormal noise may occur. There is.

  In order to solve the above-described problems, an object of the present invention is to provide a coating film that is less likely to cause wear and less likely to generate abnormal noise and that is excellent in unnecessary durability of grease.

In order to solve the above problems, the gist of the invention described in claim 1 is that it comprises a silicone oil having a viscosity of 3000 mm ² / S or less, 30 wt% silica, a curing catalyst, and a silicone resin.

That is, since it is composed of a silicone oil having a viscosity of 3000 mm ² / S or less, 30 wt% silica, a curing catalyst, and a silicone resin, since it contains a lubricating component, it is difficult to cause wear and the coefficient of friction does not vary.

  The invention described in claim 2 is an organic-inorganic hybrid type silicone resin obtained by hydrolytic polycondensation of trifunctional silanes and having a friction coefficient of 0.4 to 0.5. It is said.

  That is, the silicone resin is an organic-inorganic hybrid silicone resin obtained by hydrolytic polycondensation of trifunctional silanes, and the friction coefficient is kept constant by setting the friction coefficient to 0.4 to 0.5. Can do.

The gist of the invention described in claim 3 is that it contains any one of an organic tin compound, an organic aluminum compound, and an organic titanium compound as a curing catalyst.
That is, by including any of an organic tin compound, an organic aluminum compound, and an organic titanium compound as a curing catalyst, an appropriate cured product having a short processing time can be obtained.

The gist of the invention described in claim 4 is that the silicone resin composition is coated on the friction portion between the bracket, the column tube, and the support shaft, which are steering column components.
That is, by coating the silicone resin composition on the friction parts between the brackets, column tubes, and spindles that are steering column parts, it is possible to prevent the occurrence of abnormal noise by suppressing the relative movement due to vibration and load of each part. .

It is possible to provide a coating film that is less likely to cause wear and less likely to generate abnormal noise and that has excellent durability that does not require grease.
In addition, the steering parts with coating film are effective in preventing the occurrence of stick-slip because they are not affected by the sliding speed and load conditions, and the generation of abnormal noise is avoided without using a special lubricant such as grease. Therefore, it is possible to provide a high-quality steering device with good durability.

It is a mimetic diagram showing a schematic structure of a position adjustment type steering device concerning one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the position-adjustable steering device along the line II-II in FIG. 1. FIG. 3 is a schematic external view of a part of the position-adjustable steering device as viewed from the direction of arrow III in FIG. 2. It is the figure which expanded a part of FIG. It is a figure of the measurement result of the friction coefficient at the time of a load change. It is a figure of the measurement result of the friction coefficient at the time of sliding speed change.

  1: Position-adjustable steering device, 4: Steering shaft (steering shaft), 11: Outer tube, 12: Inner tube, 13: Vehicle body, 17: Column side bracket (inner bracket), 18: Body side bracket (outer) Bracket), 19: locking mechanism, 21: pressing member, 22: operation lever, 23: side plate (side plate of inner bracket), 30: side plate (side plate of outer bracket), 38: support shaft, 49: opening, 54: Press part, X1: axial direction, Y1: circumferential direction (circumferential direction of the inner tube)

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a schematic diagram showing a schematic configuration of a position-adjustable steering apparatus 1 according to an embodiment of the present invention. Referring to FIG. 1, a position-adjustable steering apparatus 1 includes a steering member 2 such as a steering wheel, and a steering mechanism 3 that steers a steered wheel (not shown) in conjunction with the steering of the steering member 2. Yes. As the steering mechanism 3, for example, a rack and pinion mechanism is used.

  The steering member 2 and the steering mechanism 3 are mechanically connected via a steering shaft 4, an intermediate shaft 5, and the like. The rotation of the steering member 2 is transmitted to the steering mechanism 3 via the steering shaft 4 and the intermediate shaft 5. Further, the rotation transmitted to the steering mechanism 3 is converted into an axial movement of a rack shaft (not shown). Thereby, a steered wheel is steered.

  The steering shaft 4 has a cylindrical upper shaft 6 and a lower shaft 7 which are fitted so as to be able to slide relative to each other by, for example, spline fitting or serration fitting. The steering member 2 is connected to the upper end portion of the upper shaft 6. Further, the steering shaft 4 can be expanded and contracted in the axial direction X1. The steering shaft 4 is inserted through the inner periphery of a cylindrical steering column 8 and is rotatably supported by the steering column 8 via a plurality of bearings 9 and 10.

  The steering column 8 has an outer tube 11 as an upper tube fitted so as to be relatively slidable, and an inner tube 12 as a lower tube. The steering column 8 can be expanded and contracted in the axial direction. The outer tube 11 rotatably supports the upper shaft 6 via the bearing 9 and is connected to the upper shaft 6 via the bearing 9 so as to be able to move along the axial direction X1 of the steering shaft 4.

Further, on the outer periphery of the inner tube 12, a lower bracket 16 that is rotatably supported via a tilt support shaft 15 is fixed to a fixed bracket 14 that is fixed to the vehicle body 13.
The steering column 8 and the steering shaft 4 are rotatable about a tilt support shaft 15 as a fulcrum. By using the tilt support shaft 15 as a fulcrum, the height of the steering member 2 can be adjusted by expanding and contracting the steering shaft 4 and the steering column 8 in the axial direction X1 (so-called telescopic adjustment).

  A column side bracket 17 is fixed to the outer tube 11, and the column side bracket 17 and the vehicle body side bracket 18 fixed to the vehicle body 13 are connected by a lock mechanism 19, so that the position of the steering column 8 is the vehicle body. 13 and the position of the steering member 2 is fixed. In this embodiment, the column side bracket 17 functions as an inner bracket, and the vehicle body side bracket 18 functions as an outer bracket.

Further, the lock mechanism 19 includes a pressing member 21 having a cam-like protruding portion 20, and the inner tube 12 is pressed against the outer tube 11 by rotating the pressing member 21 by the operation of the operation lever 22. An inner tube 12 is fixed to the tube 11.
FIG. 2 is a schematic cross-sectional view of the position-adjustable steering apparatus 1 along the line II-II in FIG. FIG. 3 is a schematic external view of a part of the position-adjustable steering apparatus 1 as seen from the direction of arrow III in FIG.

  Referring to FIG. 2, the column side bracket 17 is a groove-shaped member that opens upward, and is symmetric in FIG. That is, the column side bracket 17 includes a pair of side plates 23 that face each other in the left-right direction in FIG. 2 and a connecting plate 24 that connects the lower ends of the pair of side plates. Each side plate 23 and the connecting plate 24 are continuously connected to each other via the lower curved portion 25.

  Referring to FIGS. 2 and 3, each side plate 23 has a substantially rectangular shape as shown in FIG. 3, and a telescopic slot 26 that is elongated in the axial direction X1 is formed at the lower end portion thereof. ing. The steering shaft 4 and the steering column 8 can be expanded and contracted within the range of the axial length of the long hole 26. As shown in FIG. 2, the long holes 26 formed in the side plates 23 face each other.

  Further, as shown in FIG. 2, the upper end portion of each side plate 23 is bent inside the column side bracket 17 to form a bent portion 27. Each side plate 23 includes a bent portion 27 and a main body portion 28. Each side plate 23 has a bent portion 27 fixed to the outer peripheral surface of the outer tube 11. The bent portion 27 and the main portion 28 are continuously connected via the upper curved portion 29. The main body portion 28 is a portion corresponding to between the lower curved portion 25 and the upper curved portion 29. (This is the portion corresponding to the area between the two-dot chain line L1 and the two-dot chain line L2 shown in FIG. 3).

  2 and 3, the vehicle body side bracket 18 is a generally groove-shaped member that opens downward as shown in FIG. 2, and a pair of side plates 30 facing each other in the left-right direction in FIG. The connecting plate 31 includes a connecting plate 31 that connects the upper ends of the pair of side plates 30 and a plate-like mounting stay 32 that is fixed to the upper surface of the connecting plate 31 and extends substantially in the left-right direction. The steering shaft 4, the steering column 8, and the column side bracket 17 are arranged between a pair of side plates 30 of the vehicle body side bracket 18 in FIG. The vehicle body side bracket 18 is fixed to the vehicle body 13 via a pair of attachment bodies 33 connected to the attachment stay 32.

  Each mounting body 33 and the mounting stay 32 are connected by a breakable synthetic resin pin 34 penetrating the mounting stay 32 in the vertical direction, and each mounting body 33 is fixed to the vehicle body 13 by a fixing bolt 35. ing. As shown in FIG. 3, the mounting stay 32 is formed with a pair of notches 36 extending from the end on the steering member 2 side along the axial direction X1. The heads of the pair of fixing bolts 35 are respectively disposed in the corresponding notches 36.

  Further, as shown in FIG. 2, each side plate 30 has an inner side surface 30b facing the outer side surface of the corresponding side plate 23 of the column side bracket 17, and a lower end of the side plate 30 has a longitudinally long tilt. A circular arc-shaped long hole 37 is formed. The arc-shaped long holes 37 formed in the side plates 30 face each other. Further, as shown in FIG. 3, each side plate 30 is disposed such that the arc-shaped long hole 37 intersects the long hole 26 of the side plate 23 corresponding to the side plate 30. As shown in FIG. 2, a coating of a silicone resin composition is formed on the outer peripheral surface of the tilting support shaft 38. A support shaft 38 that is a part of the lock mechanism 19 and is coated with the developed material passes through a pair of telescopic long holes 26 and a pair of tilted arc-shaped long holes 37 in the left-right direction.

  Referring to FIG. 2, the lock mechanism 19 sandwiches the vehicle body side bracket 18 in the left-right direction in FIG. 2 to hold the column side bracket 17 on the vehicle body side bracket 18 and presses the inner tube 12 to The inner tube 12 is fixed to the tube 11, and is fitted on the outer periphery of the support shaft 38, a nut 39 that is screwed to a thread portion formed at one end of the support shaft, and the support shaft 38. A combined annular cam 40 and an annular cam follower 41 and a pressing member 21 for pressing the inner tube 12 are included.

  The cam 40 and the cam follower 41 are disposed on the head 38a side of the support shaft 38, and the end portion 42 of the cam 40 and the end portion 43 of the cam follower 41 on which a plurality of cam protrusions are formed face each other. The pressing member 21 is coupled between the pair of side plates 23 of the column side bracket 17 so as to be able to rotate along with the axially intermediate portion of the shaft portion 38 b of the support shaft 38. An intervening member 44 such as a needle bearing or a washer is interposed between the nut 39 and the pressing member 21.

  The interposition member 44 is in contact with the outer surface 30a of one side plate 30 (the right side plate 30 in FIG. 2) of the vehicle body side bracket 18, and the contact surface 44a of the interposition member 44 in contact with the outer surface 30a is illustrated in FIG. 2 is a substantially vertical annular surface. The contact surface 44a of the interposition member 44 functions as a clamping surface for clamping the vehicle body side bracket 18. The cam 40 is connected to the support shaft 38 so as to be able to rotate together. When the support shaft 38 is rotated about its central axis by the operation of the operation lever 22, the cam 40 is rotated accordingly. The cam 40 is disposed between the other side plate 30 (the left side plate 30 in FIG. 2) of the vehicle body side bracket 18 and the head portion 38 a of the support shaft 38.

  The cam follower 41 is fitted to the outer periphery of the shaft portion 38b of the support shaft 38 so as to be relatively rotatable. The cam follower 41 is restricted from rotating by engaging with a long hole 26 formed in one side plate 23 (the left side plate 23 in FIG. 2) of the column side bracket 17. The cam follower 41 is in contact with the outer side surface 30a of the other side plate 30 of the vehicle body side bracket 18, and the contact surface 41a of the cam follower 41 in contact with the outer side surface 30a is a substantially vertical annular surface in FIG. Yes. The contact surface 41 a of the cam follower 41 functions as a clamping surface for clamping the vehicle body side bracket 18. That is, in the present embodiment, the contact surface 44a of the interposition member 44 and the contact surface 41a of the cam follower 41 function as a pair of sandwiching surfaces that sandwich the vehicle body side bracket 18.

  As shown in FIG. 4, annular grooves 45 and 46 are formed on the inner circumferences of the end portions 42 and 43 of the cam 40 and the cam follower 41 that face each other. The pair of annular grooves 45, 46 communicate with each other, and an annular elastic member 47 is interposed between the pair of annular grooves 45, 46 and the outer periphery of the shaft portion 38 b of the support shaft 38. As the elastic member 47, for example, an O-ring, a rubber tube, a synthetic resin material, or the like can be used.

  The elastic member 47 urges the cam 40 and the cam follower 41 in the axial direction and the radial direction of the support shaft 38 in a state where the cam 40 and the cam follower 41 are not engaged or in a state where the engagement is loosened. Does not vibrate. Thereby, generation | occurrence | production of the noise resulting from the vibration of the cam 40 and the cam follower 41 is prevented. Further, by disposing the elastic member 47 between the pair of annular grooves 45 and 46 and the outer periphery of the shaft portion 38b of the tilt support shaft 38, the engagement between the cam 40 and the cam follower 41 is not hindered. .

  Referring to FIG. 2, the inner tube 12 includes a metal tube 50 made of, for example, a metal, and a resin tube 51 made of, for example, a synthetic resin fitted to the outer periphery of the metal tube 50. A plurality of convex portions 52 are formed in the resin tube 51 at intervals in the circumferential direction. Although not shown, the plurality of convex portions 52 are formed at a plurality of locations spaced in the axial direction of the resin tube 51. The convex portion 52 may be formed on the metal tube 50.

  Further, the pressing member 21 includes a cylindrical portion 48 and a cam-like protruding portion 20 that is formed to project from the intermediate portion in the axial direction of the cylindrical portion 48. The pressing member 21 is, for example, serration-fitted or spline-fitted to the shaft portion 38b of the support shaft 38, whereby the pressing member 21 is connected to the support shaft 38 so as to be able to rotate together. The cam-like protrusion 20 protrudes from a part of the cylindrical portion 48 in the circumferential direction, and the upper end of the cam-like protrusion 20 enters the outer tube 11 through the opening 49 formed in the outer tube 11. ing. The upper end surface of the cam-shaped protrusion 20 is an arc-shaped surface in which the distance from the center of the tubular portion 48 continuously changes in the circumferential direction of the tubular portion 48. (See Figure 1)

  Specifically, a concave portion 53 having a rectangular cross section is formed at the upper end portion of the cam-like projection portion 20, and the left and right sides of the concave portion 53 serve as pressing portions 54. The upper end surface of each pressing portion 54 is an arc-shaped surface corresponding to the shape of the outer peripheral surface of the metal tube 50 with respect to the axial direction of the tubular portion 48, and the metal is changed according to the operation of the operation lever 22. It contacts or leaves the outer peripheral surface of the tube 50.

  When the operating lever 22 is rotated in a predetermined direction, the support shaft 38 and the cam 40 are rotated accordingly, and the cam 40 pushes the cam follower 41 toward the right in FIG. 2 and the cam follower 41 moves to the right. . As a result, the pair of side plates 30 of the vehicle body side bracket 18 are clamped in the left-right direction by the lock mechanism 19. As a result, the vehicle body side bracket 18 is elastically bent so that the distance between the pair of side plates 30 is narrowed. When the amount of bending of the vehicle body side bracket 18 exceeds a predetermined value, the side plates 30 of the vehicle body side bracket 18 are pressed against the corresponding side plates 23 of the column side bracket 17. That is, the pair of side plates 23 of the column side bracket 17 is sandwiched between the pair of side plates 30 of the vehicle body side bracket 18, the column side bracket 17 is held by the vehicle body side bracket 18, and the column side bracket 17 is locked.

  Further, at this time, when the operation lever 22 is rotated in a predetermined direction, the support shaft 38 and the pressing member 21 are rotated accordingly, and a pair of the levers 22 are spaced apart in the circumferential direction Y1 of the inner tube 12. The pressing portions 54 come into contact with the outer peripheral surface of the metal tube 50. When each of the pair of pressing portions 54 comes into contact with the outer peripheral surface of the metal tube 50, each pressing portion 54 presses the inner tube 12, and as a result, the inner tube 12 comes into contact with the outer tube 11. It is like that.

  In the present embodiment, the pressing surface can be increased by pressing the inner tube 12 at a plurality of positions spaced apart in the circumferential direction Y1 of the inner tube 12 by the pair of pressing portions 54 of the pressing member 21. In the state where the tube 12 and the pressing member 21 are in contact with each other, the backlash between the inner tube 12 and the outer tube 11 can be removed, and the support rigidity for the entire steering column 8 can be improved to increase the resonance frequency. Therefore, when the inner tube 12 and the pressing member 21 are in contact with each other, it is possible to prevent the steering column 8 from resonating, for example, during idling.

  Further, by rotating the operation lever 22 in a predetermined direction, the position of the steering column 8 is fixed with respect to the vehicle body 13, and the tilt adjustment and telescopic adjustment are restricted. At this time, the operation force applied to the operation lever 22 functions as a force by which the vehicle body side bracket 18 clamps the column side bracket 17, that is, a holding force of the column side bracket 17 by the vehicle body side bracket 18.

  On the other hand, when the operation lever 22 is rotated in the direction opposite to the predetermined direction with the position of the steering column 8 being fixed with respect to the vehicle body 13, the vehicle body 13 is returned to the original position. The position of the steering column 8 with respect to the lock is released, and the tilt adjustment and telescopic adjustment can be performed. In a state where the column side bracket 17 is sandwiched between the vehicle body side brackets 18, a part of each side plate 30 of the vehicle body side bracket 18 follows the shape of the corresponding side plate 23 of the column side bracket 17. The outer side surface 28a of the main body portion 28 of each side plate 23 and the inner side surface 30b of the side plate 30 of the vehicle body side bracket 18 opposed thereto are in contact with each other.

  On the other hand, when the vehicle body side bracket 18 is tightened by the lock mechanism 19. The pair of side plates 30 are elastically bent so that the interval between them becomes narrow, but since the pair of side plates 23 of the column side bracket 17 is disposed inside the pair of side plates 30, when the amount of bending exceeds a predetermined value. Each of the side plates 23 contacts the pair of side plates 23 of the column side bracket 17, and the shape of the inner side surface 30b follows the shape of the corresponding outer side surface of the side plate 23. Thereby, the inner side surface 30b of each side plate 30 of the vehicle body side bracket 18 and the outer side surface 28a of the main body portion 28 of each side plate 23 of the column side bracket 17 facing each other are in contact with each other (in FIG. Hatched). That is, in this embodiment, a sufficient contact area between the column side bracket 17 and the vehicle body side bracket 18 is ensured.

  As described above, in this embodiment, since a sufficient contact area between the column side bracket 17 and the vehicle body side bracket 18 is ensured, the holding force of the column side bracket 17 by the vehicle body side bracket 18 is sufficiently ensured. The rigidity of the contact portion between the side bracket 17 and the vehicle body side bracket 18 is improved. Thereby, for example, it is possible to prevent the steering column 8 from resonating due to the vibration of the vehicle during idling.

  In the present embodiment, the distance between the outer surfaces 28a of the main body 28 is set to become narrower as it goes downward, so that not only the operating force applied to the operating lever 22 but also the column side The force due to the weight of the bracket 17 and the steering column 8 can be applied as a force by which the vehicle body side bracket 18 clamps the column side 17, that is, a holding force of the column side bracket 17 by the vehicle body side bracket 18.

  Specifically, the pair of side plates 30 of the vehicle body side bracket 18 is changed from the pair of side plates 23 of the column side bracket 17 to the pair of side plates 30 of the vehicle body side bracket 18 by the force due to the weight of the column side bracket 17 and the steering column 8. Thus, the side plate 23 of the column side bracket 17 can be further pressed into contact with the corresponding side plate 30 of the vehicle body side bracket 18 by applying a force that pushes the distance between them.

  Therefore, in the position adjustment type steering apparatus 1 according to this embodiment, the holding force of the column side bracket 17 by the vehicle body side bracket 18 can be improved without increasing the operation force applied to the operation lever 22. Further, in the present embodiment, the difference between the upper side and the lower side of the interval between the outer surfaces 28a, 28a of the main body 28 (the difference between the first interval W1 and the second interval W2) is set to a predetermined value. Therefore, it is possible to prevent an excessive bending stress from being applied to the support shaft 38 and a member such as the interposition member 44 and the cam follower 41 from being loosened.

Hereinafter, the silicone resin composition for coating will be described in detail.
<Composition for lubricating coating>
The composition for lubricating coating of the present invention comprises a modified silicone resin, its curing catalyst, and a reactive silicone oil as essential components. Moreover, a solvent and another component are contained as needed. By appropriately mixing and stirring these components, the lubricating coating composition of the present invention can be prepared.
Hereinafter, each component will be described.

<Modified silicone resin>
There is no restriction | limiting in particular in the modified silicone resin used for this invention, A conventionally well-known thing can be used without a problem. What is necessary is just to select suitably from a viewpoint of required characteristics, such as compatibility with another component, reactivity, heat resistance, pressure | voltage resistance, flexibility, and crack resistance. In the lubricating coating composition of the present invention, an organic-inorganic hybrid polysilsesquioxane resin obtained by hydrolytic polycondensation of trifunctional silanes in the presence of an acrylic silicone resin is used as the modified silicone resin. Is preferred.

  The organic-inorganic hybrid polysilsesquioxane resin suitable as the modified silicone resin is excellent in reactivity and adhesion with the primer (contact surface with the object to be molded) and a primer described later, and is a reactive silicone compounded. It is preferable to have excellent heat resistance, pressure resistance, flexibility and crack resistance that are excellent in compatibility and reactivity with oil and can withstand high temperatures and high pressures.

  In general, when an inorganic silicone resin is synthesized by a sol-gel method, a tetrafunctional silane monomer such as tetraethoxysilane (TEOS) or tetramethoxysilane (TMOS) is used as a raw material. Since the crosslinking density is too high, cracks are likely to occur, and it is relatively difficult to obtain the desired characteristics. Therefore, in the present invention, by using a trifunctional silane monomer and using a resin skeleton that is an acrylic silicone chain, it follows the unevenness of the base, and has a high film thickness of about 500 μm, for example. Even if it exists, it is preferable to use a highly flexible silicone-based hybrid resin that does not crack.

  That is, in order to synthesize an organic-inorganic hybrid type polysilsesquioxane resin, (1) a (meth) acrylic monomer having a hydrolyzable alkoxysilyl group in the side chain in a suitable solvent and a radical polymerizable monomer. (2) A trifunctional silane monomer is hydrolyzed and polycondensed under suitable conditions in the presence of the acrylic silicone resin to be polymerized. Thus, a copolymer hybrid type acrylic-polysilsesquioxane resin having a structure in which an acrylic silicone resin is included in the skeleton and a polysilsesquioxane resin is copolymerized therearound is obtained. Thereby, a resin having the flexibility of acrylic and the heat resistance, crosslinking density and reactivity of polysiloxane can be obtained.

  Specific examples of the (meth) acrylic monomer having a hydrolyzable alkoxysilyl group in the side chain used for the synthesis of the acrylic silicone resin of (1) include γ- (meth) acryloxypropyltrimethoxysilane, γ Examples include-(meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, and the like.

  Further, the radical polymerizable monomer copolymerized with these to form an acrylic silicone resin is not particularly limited as long as it is copolymerizable with the hydrolyzable alkoxysilyl group-containing (meth) acrylic monomer. Rather, for example, (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate and the like having 1 to 18 carbon atoms (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate and the like , Glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, functional group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, vinyl compounds such as styrene, α-methylstyrene, N-vinylpyrrolidone it can.

  Specific examples of the trifunctional silane monomer used in the sol-gel sequencing of (2) include, for example, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, Alkyltrialkoxysilanes such as propyltrimethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, aromatic silanes such as phenyltrimethoxysilane, phenyltriethoxysilane, Examples of the functional group-containing silane monomer include γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxysilane. These may be used alone or in combination of two or more.

  As the organic-inorganic hybrid polysilsesquioxane resin obtained by the sequence of (1) and (2), a commercially available product is available, and the blending ratio of the modified silicone resin in the lubricating coating composition of the present invention As, the range of 10-98 mass% is preferable, the range of 30-80 mass% is more preferable, and the range of 50-70 mass% is further more preferable.

<Curing catalyst>
The curing catalyst suitable for use in the lubricating coating composition of the present invention is not particularly limited as long as it can cure the modified silicone resin used. For example, when the organic-inorganic hybrid polysilsesquioxane resin described above is used as the modified silicone resin, any catalyst capable of curing a moisture curable silicone oligomer can be used as the catalyst capable of curing the resin. There is no particular limitation.

  Specific examples of the curing catalyst include organic tin compounds such as dibutyltin diacetate, dibutyltin dioctylate, dibutyltin dilaurate, aluminum tris (acetylacetone), aluminum tris (acetoacetate ethyl), and aluminum diisopropoxy. (Organic acetoacetate), organic zirconium compounds such as zirconium (acetylacetone), zirconium tris (acetylacetone), zirconium tetrakis (ethylene glycol monomethyl ether), titanium tetrakis (ethylene glycol monomethyl ether), titanium tetrakis ( Ethylene glycol monoethyl ether), titanium tetrakis (ethylene glycol monobutyl ether), etc. Organic metal compounds such as organic titanium compounds; acids such as mineral acids such as hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid; organic acids such as formic acid, acetic acid, oxalic acid and trifluoroacetic acid; ammonia, sodium hydroxide, potassium hydroxide, etc. And inorganic bases, and alkalis such as organic bases such as ethylenediamine and alkanolamine; and amino compounds such as amino-modified silicones, aminosilanes, silazanes, and amines. Of these, organotin compounds, organoaluminum compounds, and organotitanium compounds are preferred.

  The curing catalyst that can be used in the present invention can be obtained as a commercial product. Examples thereof include D-20 (manufactured by Shin-Etsu Chemical Co., Ltd.), DX-9740 (manufactured by Shin-Etsu Chemical Co., Ltd.), DX-175 (manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.

  The blending ratio of these curing catalysts is preferably in the range of 0.1 to 20 parts by mass and more preferably in the range of 0.5 to 10 parts by mass with respect to 100 parts by mass of the modified silicone resin. If the blending ratio is lower than this range, curability will be inferior, and if the blending ratio is increased beyond this range, the so-called pot life (time from exposure to outside air to completion of coating ≒ coating work possible time ) Is shortened, which is not preferable for practical use.

<Reactive silicone oil>
There is no restriction | limiting in particular in the reactive silicone oil in this invention, A conventionally well-known thing can be used without a problem. What is necessary is just to select suitably from a viewpoint of the reactivity with a modified silicone resin, and lubrication function expressiveness.

In the lubricating coating composition of the present invention, it is preferable to use two types of reactive silicone oils in combination. Specifically, a low molecular weight silicone oil having a kinematic viscosity (25 ° C.) of less than 100 mm ² / S (hereinafter sometimes referred to simply as “low molecular weight silicone oil”) and a both terminal silanol type is kneaded. There are two types: high molecular weight silicone oil (hereinafter sometimes simply referred to as “high molecular weight silicone oil”) having a viscosity (25 ° C.) of 2000 mm ² / S or more.

  Silicone oil generally has a low molecular weight and a low viscosity, and a high molecular weight has a high viscosity. Therefore, for the sake of convenience, the two silicone oils are distinguished by being referred to as “low molecular weight” and “high molecular weight”, but they are defined only by kinematic viscosity and cannot be strictly defined by the molecular weight value.

  Low molecular weight silicone oils are excellent in compatibility and reactivity with modified silicone resins, particularly organic-inorganic hybrid polysilsesquioxanes, but are slightly inferior in heat resistance. On the other hand, although high molecular weight silicone oil is slightly inferior in the compatibility and reactivity, it is excellent in heat resistance and pressure resistance. Therefore, by using these two types of reactive silicone oils in combination, a lubricating coating having excellent durability can be obtained even under severe use conditions.

The reactive silicone oil that can be used in the present invention is available as a commercial product. For example, both-end silanol type low molecular weight silicone oil is YF3800 (kinematic viscosity = 80 mm ² /, manufactured by Momentive Performance Materials Japan), Examples of the both-end silanol type high molecular weight silicone oil include YF3057 (kinematic viscosity = 3000 mm ² / manufactured by Momentive Performance Materials Japan). The blending ratio of both silicone oils is preferably in the range of 9: 1 to 1: 9 as “low molecular weight”: “high molecular weight”, and more preferably in the range of 7: 3 to 3: 7. preferable.

  The blending ratio of the total reactive silicone oil in the lubricating coating composition of the present invention is preferably in the range of 0.1 to 20% by mass with respect to the modified silicone resin active ingredient (solid content), and is preferably 0.2 to 10%. The range of mass% is more preferable, and the range of 0.3 to 5 mass% is more preferable. If the amount of reactive silicone oil added is less than 0.1% by mass, it is difficult to obtain a good lubricating effect, and if it exceeds 20% by mass, the amount of unreacted components increases, so-called separation may occur, which is undesirable in production. .

<Solvent>
You may mix | blend a solvent with the composition for coating of this invention. By blending the solvent, the concentration and viscosity (kinematic viscosity) can be appropriately adjusted. The solvent that can be used is not particularly limited as long as it can dissolve or disperse the modified silicone resin, the curing catalyst, and the reactive silicone oil, which are essential constituent components. For example, methanol, ethanol, n-propanol, isopropanol, Alcohol solvents such as n-butanol, isobutanol, s-butanol, t-butanol; petroleum solvents such as mineral spirits; fats such as hexane, heptane, n-octane, i-octane, nonane, decane, undecane, dodecane Aromatic hydrocarbon solvents such as cyclohexane, methylcyclohexane and dimethylcyclohexane; Aromatic hydrocarbon solvents such as benzene, toluene and xylene; Esters such as butyl acetate, ethyl acetate and isobutyl acetate Solvent; Octame Low-polymerization degree (low molecular weight) cyclic methylpolysiloxane (cyclic silicone) such as lucyclotetrasiloxane, and low-polymerization degree linear methylpolysiloxane (linear silicone) such as octamethyltrisiloxane and decamethyltetrasiloxane ) And the like. These solvents may be used alone or in combination of two or more.

<Other ingredients>
Various other conventionally known additives can also be added to the coating composition of the present invention. Additives that can be added are preferably those that do not affect the performance of the formed lubricating film or are light, such as various antifoaming agents, leveling agents, slipping agents, antioxidants, rust inhibitors, etc. Can be mentioned.

  In the present invention, a silicone acrylic primer layer is formed as a base layer on the contact surface with the object to be molded, and a lubricating film containing the coating composition of the present invention laminated thereon is further formed. It is.

  Since the coating composition of the present invention has insufficient wettability and adhesion to materials made of bearing steel and carbon steel, a silicone acrylic primer layer having excellent wettability and adhesion to these metals is used. After forming as a base layer, it is further laminated thereon to form a film made of the coating composition of the present invention.

  The product of the present invention in which a film composed of the coating composition of the present invention is laminated with a silicone acrylic primer layer as an underlayer is excellent in durability such as heat resistance and pressure resistance, and also has flexibility and crack resistance. In addition, it can maintain excellent characteristics, and is extremely useful with excellent productivity and economy.

  The coating film for forming the silicone acrylic primer layer can be formed using any conventionally known primer made of a silicone acrylic resin. The film thickness of the entire film when forming the silicone acrylic primer layer is preferably as thin as possible in view of dimensional accuracy, and if it is too thin, the function as a film cannot be exhibited. Therefore, the silicone acrylic primer layer is preferably in the range of 2 μm to 10 μm, more preferably in the range of 4 μm to 6 μm, while the coating layer by the coating composition of the present invention is 2 μm to 10 μm. The range is preferable, and the range of 4 μm to 6 μm is more preferable. The manufacturing method of the article of the present invention, that is, the film forming method will be described in detail in the next section.

<Film Formation Method and Manufacturing Method>
In the method of forming a film of the present invention, the surface to be coated is coated with a solvent-type silicone acrylic primer, and then coated with the coating composition of the present invention without baking and curing, and then the entire coating film is baked and cured. It is characterized by this.

  The solvent-type silicone acrylic primer that can be used in the present invention is excellent in wettability and adhesion to the surface of the substrate to be coated, and reacts and integrates with the coating composition of the present invention. Are preferred. In particular, a silicone acrylic primer resin composition using a glycidyl group-containing silane compound as a curing agent in an acrylic polymer main component having a tertiary amino group in the side chain as a curing agent has excellent wettability to various metals. The reaction with the coating composition of the invention can be expected, which is very suitable. Commercially available products are available as such silicone acrylic primer resins.

  The coating method for the surface to be coated is not particularly limited, and a known method may be used as appropriate, for example, impregnating a sponge with a coating agent and rubbing the painted surface with the sponge. In addition, the coating method can be selected as appropriate, such as a dipping method, a brush coating method, and a spray coating method.

  After coating the surface to be coated with a solvent-type silicone acrylic primer by these coating methods, the coating composition is coated without baking and curing, and then the entire coating film is baked and cured. One baking is preferable. Thus, by carrying out 2 coat 1 bake, the coating film layer which the primer and the said coating layer were integrated is formed, and it becomes excellent in surface smoothness and becomes a dense lubricating layer.

  The temperature condition for baking and hardening of the entire coating film is preferably in the range of 160 ° C to 220 ° C, and more preferably in the range of 190 ° C to 210 ° C. If the temperature is too low, physical properties will not be exhibited, while if it is too high, thermal degradation and thermal decomposition will occur, which is not preferable.

  Further, the baking hardening time of the entire coating film is preferably in the range of 10 minutes to 60 minutes, and more preferably in the range of 20 minutes to 40 minutes. If the bake hardening time is too short, it is uniform, while if it is too long, a so-called burning phenomenon occurs and the appearance is impaired.

<Example 1, comparative example 1>
According to the composition shown in Table 1 below, a primer, a coating composition of Example 1 and Comparative Example 1 were prepared. Using these materials, a carbon steel substrate is coated with a primer by dipping, and further coated with the coating composition of each example or comparative example, and then thermally cured at 200 ° C. for 30 minutes, so-called 2-coat 1-baking ( In Comparative Example 1, a test plate was obtained through a coating process of 1 coat and 1 bake. Table 1 below summarizes the conditions including the film thickness.

In addition, the detail of the compounding component used for the Example and the comparative example is described below.
<Silicone acrylic primer main agent>
Acrylic resin Acrydic A-9540 having a tertiary amino group in the side chain (manufactured by DIC Corporation, active ingredient = 45%, Gardner foam viscosity (25 ° C.): (XY) -Z2, amine value: 16, solvent: toluene / isobutanol) was diluted with 60 parts of xylene to obtain a silicone acrylic primer main ingredient.

<Silicone acrylic primer curing agent>
Epoxy silane coupling agent-containing silicone acrylic resin curing agent ACRICID A-9585 (manufactured by DIC Corporation, active ingredient = 80%, Gardner foam viscosity (25 ° C.): A5 or less, epoxy equivalent: 530-585, solvent : Xylene) was diluted with 144 parts of xylene to obtain a silicone acrylic primer curing agent.

<Hybrid type polysilsesquioxane resin main agent>
A 1-liter four-necked flask equipped with an N2 introduction tube, a thermometer, a thermometer, and a reflux condenser was charged with 353 parts of methanol and heated to 60 ° C. Separately, 122 parts methyl methacrylate (MMA), 116 parts butyl methacrylate (BMA), 163 parts ethyl acrylate (EA), hydrolyzable alkoxysilyl group-containing methacrylic monomer KBM-503 (manufactured by Shin-Etsu Chemical Co., Ltd.) 94 parts of a mixture of 5.9 parts of an azo polymerization initiator V-65 (Wako Pure Chemical Industries, Ltd., 2,2′-Azobis (2.4-dimethylvalerontrile)) was weighed and taken in a dropping funnel over 3 hours. And dropped into the flask. After the addition, the mixture was further reacted at 60 ° C. for 2 hours, and a solution obtained by diluting V-651.5 parts with 45 parts of methanol was added dropwise, and then the reaction was continued at 60 ° C. for 3 hours to obtain an acrylic silicone resin solution ( Pale yellow transparent viscous liquid, active ingredient = 55%, Gardner foam viscosity (25 ° C.): XY +, Mw = 121000).

  Next, 121 parts of the acrylic silicone resin solution obtained above, 459 parts of methyltrimethoxysilane (MTMS) and 74 parts of phenyltrimethoxysilane (PTMS) were attached to the N2 introduction tube, thermometer, thermometer and reflux condenser. Into a 1-liter four-necked flask, 20 parts of 2 mol / liter dilute hydrochloric acid, 48 parts of distilled water, and 78.7 parts of methanol were added dropwise using a dropping funnel over 30 minutes. Meanwhile, the temperature in the flask was kept at 40 ° C. After further aging at 40 ° C. for 30 minutes, the temperature was raised and the reaction was carried out for 3 hours under reflux. The reflux temperature was 65-68 ° C. Thereafter, the reflux condenser is replaced with a dehydration condenser, heated until the temperature reaches 135 ° C., the solvent in the reaction system is distilled off over 2 hours, then cooled, and the organic-inorganic hybrid polysilsesquioxide is cooled. Sun resin was obtained. Pale yellow transparent viscous liquid, organic / inorganic = 20/80 (mass basis), active ingredient = 100%, Gardner foam viscosity (25 ° C.): W, Mw = 1600.

<Evaluation test>
A friction and wear test was performed on each of the obtained test plates of Examples and Comparative Examples.
Using a Ball-on-Disc type reciprocating friction tester, the evaluation was performed at room temperature under non-lubricating conditions. The disc test piece (25 × 30 mm, thickness 5 mm) was prepared by applying the lubricating coating treatment (primer + lubricating coating composition + dry curing) of each of the examples to the comparative example. A polyacetal resin [polyoxymethylene (POM), diameter d = 3/16 inch≈4.76 mm] was used. These test pieces were subjected to ultrasonic cleaning in acetone for 5 minutes prior to the test, dried, and then subjected to the test. The test conditions were an average linear velocity of 20 mm / S (stroke: 10 mm) and a load of 2N. The test was performed for 1500 seconds, and the friction coefficient when 1500 seconds passed was obtained. The friction and wear test was performed on Example 1 and Comparative Example 1.
The test results are shown in FIG.

  As shown in FIG. 5, in the case of silicone resin and silicone oil, the low frictional behavior of 0.1 or less was shown throughout without being affected by the load, whereas any test load when silica of Example 1 was included. Also showed a stable high coefficient of friction of 0.4 to 0.45.

  FIG. 6 shows the measurement result of the coefficient of friction when the sliding speed is changed. Even if the speed is changed, the friction is not so much changed and high friction is shown. Silica can be added to the silicone resin to adjust the coefficient of friction. At high loads, silicone oil prevents adhesion and friction is stable. Friction is generated by friction between silica and the mating material. And it can be adjusted by the amount.

As shown in FIG. 6, the friction mechanism is generated by the interference between the silica and the counterpart material, and the resistance is proportional to the amount, which has a feature that does not depend on the speed. In general, if a lubricant is present, the viscosity decreases due to frictional heat and the friction torque decreases sharply, resulting in inconveniences such as stick slip. Absent. This has the characteristic that it does not change even if the load is increased.
Further, since it is not affected by the sliding speed, it is effective in preventing the occurrence of stick slip. Therefore, generation of abnormal noise can be prevented without using a special lubricant such as grease.

  In order to prevent stick-slip with a lubricant, it is necessary to make the viscosity extremely high or to add a solid lubricant to the additive, but the outflow of the lubricant becomes a problem and there is a problem in durability. This product is normally fixed to a silicone resin. Under high load and high sliding speed conditions, silicone oil is prevented from welding as a lubricant and controlled to a stable friction to eliminate friction fluctuations and improve operation. There is an effect that can prevent the malfunction. Moreover, it begins to bleed out under a high load and can prevent welding.

The viscosity of the silicone oil is optimally 4000 mm ² / S or less, and if a very high viscosity is used, the fluidity is lowered at a low temperature and the torque becomes high. Therefore, it is necessary to set a viscosity in an appropriate range. By doing so, it can be used with a stable torque in a wide temperature range from low temperature to high temperature, and stick-slip does not occur and abnormal noise can be prevented. Conventionally, the frictional force decreases with respect to speed, and if the frictional force is small when there is no load, there is a problem that the neutral position is unstable and fluctuates due to external vibration or small force. Therefore, even if the load from the outside is small, the friction is large so that neutrality can be maintained stably, and when an impact occurs, it acts as a damper with a large frictional force. Since the friction force does not change, a constant steering can be performed, so that there is a sense of stability and there is no fluctuation in the friction force.

Claims (4)

A silicone resin composition comprising a silicone oil having a viscosity of 3000 mm ² / S or less, 30 wt% silica, a curing catalyst, and a silicone resin. 2. The silicone according to claim 1, wherein the silicone resin is an inorganic-organic hybrid silicone resin obtained by hydrolytic polycondensation of trifunctional silanes, and has a friction coefficient of 0.4 to 0.5. Resin composition. 3. The silicone resin composition according to claim 1, wherein the curing catalyst contains any one of an organotin compound, an organoaluminum compound, and an organotitanium compound. The steering device according to any one of claims 1 to 3, wherein the silicone resin composition is coated on a friction portion between a bracket, a column tube, and a support shaft, which are steering column components.