JP3244181U - laminate - Google Patents

Abstract

The present invention provides a laminate having excellent sliding properties and wear resistance. [Solution] A laminate 10 includes a base material layer 2 and a sliding layer 1 which is directly or indirectly laminated on a part or all of the surface of the base material layer and whose main component is a crosslinked fluororesin. , the base material layer is composed of fluororesin-impregnated glass cloth. The sliding layer has a plurality of grooves 3 on the outer surface 9, the average width of the plurality of grooves is 100 μm or more and 1000 μm or less, the average depth is 30 μm or more and 500 μm or less, and the average interval is 250 μm or more and 3000 μm or less, and the plurality of grooves are Some or all of the grooves are independent grooves, and the plurality of grooves extend in intersecting directions and are arranged in a grid pattern as a whole. [Selection diagram] Figure 3

Description

The present disclosure relates to a laminate.

Fluororesins have excellent heat resistance, chemical resistance, and weather resistance, as well as low adhesion and friction coefficients, and excellent sliding properties. Therefore, fluororesins are considered to be useful as coatings for various base materials and as sliding members. In conventional technology, heat-resistant resins such as modified polytetrafluoroethylene resins obtained by irradiation with ionizing radiation are used to provide sliding members with high heat-resistant stability that can withstand long-term use. A sliding member made of a non-porous sheet has been proposed (see Patent Document 1).

Japanese Patent Application Publication No. 2004-206105

The laminate of the present disclosure includes a base material layer, and a sliding layer that is directly or indirectly laminated on a part or all of the surface of the base layer and has a crosslinked fluororesin as a main component, The material layer is composed of fluororesin-impregnated glass cloth.

FIG. 1 is a schematic cross-sectional view showing a laminate according to an embodiment of the present disclosure. 2 is a schematic partially enlarged plan view of the laminate shown in FIG. 1. FIG. FIG. 3 is a cross-sectional view of the laminate shown in FIG. 2 taken along line AA. FIG. 4 is a schematic partially enlarged sectional view showing a state in which a lubricant is applied to the outer surface of the laminate shown in FIG. FIG. 5 is a schematic cross-sectional view showing a laminate according to another embodiment of the present disclosure. FIG. 6 is a schematic plan view showing a modification of the sliding layer. FIG. 7 is a schematic plan view showing another modification of the sliding layer.

[Problem that the idea aims to solve]
Fluororesin has a low coefficient of friction and is slippery, but also prone to wear. Therefore, when a fluororesin is used for a sliding member, durability tends to be insufficient.

From this point of view, crosslinking the fluororesin may be considered in order to improve the durability of the fluororesin.

Furthermore, depending on the application, it may be possible to improve the slipperiness by applying a lubricant such as oil or grease to the surface of the layer containing the fluororesin. However, when the surface of a fluororesin is flat, the lubricant tends to move, and it is difficult to keep the lubricant on the surface for a long period of time.

The present disclosure was made based on such circumstances, and an object of the present disclosure is to provide a laminate having excellent sliding properties and wear resistance.

[Effects of this disclosure]
The laminate of the present disclosure has excellent sliding properties and wear resistance.

[Description of embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described.

The laminate of the present disclosure includes:
(1) A base material layer, and a sliding layer laminated directly or indirectly on a part or all of the surface of the base material layer and mainly composed of a crosslinked fluororesin, and the base material layer is made of fluorine. Constructed from resin-impregnated glass cloth.

The laminate includes a sliding layer mainly composed of a fluororesin, and since the fluororesin is crosslinked, it has excellent wear resistance. Further, in the laminate, the sliding layer has slipperiness due to the non-adhesive property of the fluororesin. Furthermore, since the base material layer is made of fluororesin-impregnated glass cloth, it has excellent heat resistance and tensile strength. Therefore, the laminate has excellent sliding properties and wear resistance.

(2) In (1) above, it may further include an adhesive layer directly laminated between the surface of the base layer and the surface of the sliding layer. By further comprising an adhesive layer directly laminated between the surface of the base material layer and the surface of the sliding layer, the laminate can further improve the adhesiveness between the base material layer and the sliding layer. .

(3) In (1) or (2) above, the sliding layer has a plurality of grooves on the outer surface, the average width of the plurality of grooves is 100 μm or more and 1000 μm or less, and the average depth is 30 μm or more and 500 μm or less, The average interval is 250 μm or more and 3000 μm or less, some or all of the plurality of grooves are independent grooves, and the plurality of grooves extend in intersecting directions and are arranged in a grid pattern as a whole. You can leave it there. By having the plurality of grooves on the outer surface of the sliding layer, the contact area of the sliding layer with the member to be slid can be reduced. When the average width, average depth, and average interval of the plurality of grooves are within the above ranges, the contact area of the sliding layer with the member to be slid can be further reduced. In addition, when the laminate is used with a lubricant applied to the outer surface of the sliding layer, the average width and average depth of the plurality of grooves are within the above range, so that the plurality of grooves are lubricated. It is easy to retain the agent, which can further improve sliding properties.
Furthermore, since some or all of the plurality of grooves are independent grooves, the lubricant can easily stay in the independent grooves, thereby improving sliding properties. Moreover, according to this configuration, it is possible to suppress a decrease in the wear resistance of the sliding layer due to the plurality of grooves. The plurality of grooves extend in intersecting directions and are arranged in a lattice shape as a whole, so that the plurality of grooves extending in the direction along the sliding direction cause the sliding layer to slide on the member. The contact area can be easily and reliably reduced. Furthermore, when applying a lubricant to the outer surface of the sliding layer, the lubricant tends to stay in the plurality of grooves that intersect at a relatively large angle with respect to the sliding direction. Thereby, slidability can be improved.

(4) In (1) or (2) above, the sliding layer has a plurality of recesses having the same shape in plan view on the outer surface, and the plurality of recesses are arranged in plural rows on the outer surface and in each row. They are arranged at equal intervals, and the average maximum diameter in the column direction of the plurality of recesses in plan view is 100 μm or more and 1000 μm or less, and the average interval in the column direction of the plurality of recesses in plan view is 250 μm or more and 3000 μm or less. The average depth of the plurality of recesses may be 30 μm or more and 500 μm or less. The sliding layer has a plurality of recesses having the same shape in a plan view on the outer surface, and the plurality of recesses are arranged on the outer surface in a plurality of rows at equal intervals in each row, and the plurality of recesses are arranged on the outer surface at equal intervals in each row. When the average maximum diameter in the row direction in a plan view, the average interval in the row direction in a plan view of the plurality of recesses, and the average depth of the plurality of recesses are within the above ranges, the member to be slid by the sliding layer Since it is possible to reduce the contact area with the lubricant and to make it easier for the lubricant to stay in the plurality of recesses, sliding properties can be further improved.

(5) In any one of (1) to (4) above, the average thickness of the base material layer may be 50 μm or more and 150 μm or less. When the average thickness of the base layer is 50 μm or more and 150 μm or less, the strength of the base layer can be improved and it can be prevented from becoming unnecessarily thick.

(6) In any one of (1) to (5) above, the average thickness of the sliding layer may be 30 μm or more and 1000 μm or less. When the average thickness of the sliding layer is 30 μm or more and 1000 μm or less, the strength of the sliding layer can be improved and it can be prevented from becoming unnecessarily thick.

(7) In any one of (1) to (6) above, the structure of the glass cloth in the fluororesin-impregnated glass cloth may be a plain weave. Since the structure of the glass cloth in the fluororesin-impregnated glass cloth is plain weave, the base material layer can be made thin. "Plain weave" is a basic textile structure in which the warp and weft threads alternate up and down.

(8) In any one of (1) to (7) above, the resin impregnated into the fluororesin-impregnated glass cloth is polytetrafluoroethylene, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/ It may be a hexafluoropropylene copolymer, a tetrafluoroethylene-ethylene copolymer, or a combination thereof. The resin impregnated into the fluororesin-impregnated glass cloth is polytetrafluoroethylene, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, or A combination of these can improve the durability and heat resistance of the base layer.

(9) In any one of (1) to (8) above, the sliding layer comprises crosslinked polytetrafluoroethylene, crosslinked tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, or crosslinked tetrafluoroethylene/hexafluoropropylene copolymer. The main component may be a polymer, a crosslinked tetrafluoroethylene-ethylene copolymer, or a combination thereof. The sliding layer may be crosslinked polytetrafluoroethylene, crosslinked tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, crosslinked tetrafluoroethylene/hexafluoropropylene copolymer, crosslinked tetrafluoroethylene-ethylene copolymer, or a combination thereof. By using as a main component, the wear resistance and heat resistance of the sliding layer can be further improved.

(10) In any one of (2) above or (3) to (9) that cites (2) above, the adhesive layer is a tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene/hexafluoropropylene copolymer. The main component may be a copolymer, a tetrafluoroethylene-ethylene copolymer, or a combination thereof. The adhesive layer mainly contains a tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene/hexafluoropropylene copolymer, a tetrafluoroethylene-ethylene copolymer, or a combination thereof. better adhesion and heat resistance.

In the present disclosure, the term "main component" refers to the component with the highest content, for example, 60% by mass or more. "Groove" refers to a long depression. "Average groove width" means the average value of the values obtained by removing the largest five widths and the smallest five widths from among the widths of the opening portions of the grooves at arbitrary 20 points. "Average depth of a groove" means the average value of the values obtained by excluding the largest five depths and the smallest five depths among arbitrary 20 points of the groove. "Average interval between grooves" means the average value of the values obtained by excluding the largest five intervals and the smallest five interval intervals among arbitrary intervals of 20 points in the opening portions of adjacent grooves. In addition, the "average maximum diameter in the row direction of a plurality of recesses in plan view" refers to the maximum diameters of any 20 recesses in the row direction in plan view, excluding the largest five and the smallest five. means the average value of the measured values. "Average depth of a plurality of recesses" means the average value of the depths of 20 arbitrary recesses, excluding the largest five and the smallest five. "Average spacing in the column direction of a plurality of recesses in a plan view" means excluding the largest five and the smallest five of the 20 adjacent spacings in the same column in a plan view of a plurality of recesses. means the average value of the measured values.

[Details of embodiments of the present disclosure]
Hereinafter, embodiments of the laminate according to the present disclosure will be described in detail with reference to the drawings.

[First embodiment]
The laminate includes a base material layer, and a sliding layer that is directly or indirectly laminated on a part or all of the surface of the base material layer and that has a crosslinked fluororesin as a main component. The laminate is used as a sliding member. Specifically, the laminate includes, for example, a heating roller and an inner periphery of a heat resistant film in a fixing roller having a cylindrical heat resistant film that is in circumferential contact with the outer peripheral surface of the heating roller and slides in the circumferential direction of the heating roller. It can be used as a member constituting a surface or a sliding member used without lubrication. When the laminate is used, for example, in the fixing roller, it is used with a lubricant such as grease applied to the outer surface of the sliding layer. On the other hand, when the laminate is used as a sliding member that is used without lubrication, it is used without any lubricant applied to the outer surface of the sliding layer. In this way, the laminate may be used with a lubricant applied to the outer surface of the sliding layer, or may be used without a lubricant applied.

FIG. 1 shows a laminate according to an embodiment of the present disclosure. The laminate 10 shown in FIG. 1 is formed into a sheet shape as a whole. The laminate 10 includes a base layer 2 and sliding layers 1 laminated on both sides of the base layer 2. The laminate 10 is a three-layer body having a base material layer 2 and two sliding layers 1. In FIG. 1, the laminate 10 is a flat laminate, but the laminate is not limited to the shape shown in FIG. It may be arranged. Moreover, the sliding layer may be laminated on a part of the surface of the base layer. For example, the sliding layer may be laminated on one side of the base material layer, or the sliding layer may be laminated on a part of the surface of the base material layer.

In the laminate 10, since the sliding layer 1 mainly contains a crosslinked fluororesin, it has excellent wear resistance. Further, the laminate 10 has excellent sliding properties because the sliding layer 1 has slipperiness due to the non-adhesive property of the fluororesin.

Furthermore, when used with a lubricant applied to the outer surface of the sliding layer 1, the lubricant is difficult to remain on the outer surface, since the sliding layer whose main component is generally a fluororesin has excellent slipperiness. . On the other hand, in the laminate 10, radicals are generated when the fluororesin is crosslinked by irradiation with ionizing radiation, which will be described later. Therefore, the laminate 10 has good lubricant compatibility due to the radicals. Therefore, the laminate 10 can suppress the coefficient of friction between the sliding layer 1 and the member to be slid relatively low, and can sufficiently improve sliding properties.

(Sliding layer)
The sliding layer 1 has crosslinked fluororesin as its main component, so that it can improve wear resistance while maintaining the non-adhesive properties of the fluororesin.

Examples of the fluororesin in the crosslinked fluororesin include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polyvinylidene fluoroethylene. (PVDF), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinyl fluoride (PVF), fluoroolefin-vinyl ether copolymer Polymers, vinylidene fluoride-tetrafluoroethylene copolymer, and vinylidene fluoride-hexafluoropropylene copolymer are mentioned. The above-mentioned fluororesin may be PTFE, PFA, FEP, and ETFE from the viewpoint of further improving wear resistance and heat resistance, and among these, PFA and PTFE are preferable, and have the highest mechanical strength, chemical resistance, and heat resistance. PTFE is more preferable from the viewpoint of further improving properties. The above-mentioned fluororesins can be used alone or in combination of two or more types, but PTFE may be used alone in order to form the sliding layer 1 having high wear resistance.

Note that the fluororesin may contain polymerized units derived from other copolymerizable monomers within a range that does not impair the effects of the present disclosure. For example, PTFE may contain polymerized units of perfluoro(alkyl vinyl ether), hexafluoropropylene, (perfluoroalkyl)ethylene, and chlorotrifluoroethylene. The upper limit of the content of polymerized units derived from the other copolymerizable monomers is, for example, 3 mol % with respect to all polymerized units constituting the fluororesin.

The lower limit of the crosslinked fluororesin content in the sliding layer 1 may be 60% by mass, 80% by mass, 85% by mass, or 98% by mass. In particular, it is preferable that the content is 100% by mass. When the content of the fluororesin is 60% by mass or more, properties such as abrasion resistance and heat resistance can be sufficiently improved.

The sliding layer 1 may contain other optional components. Examples of this optional component include solid lubricants and reinforcing materials. When the sliding layer 1 contains a solid lubricant, a reinforcing material, etc., sliding properties can be further improved. Examples of the solid lubricant include molybdenum disulfide. Examples of the reinforcing material include glass fillers such as glass fibers and spherical glass, carbon fibers, inorganic fillers such as calcium carbonate, talc, silica, alumina, and aluminum hydroxide.

The upper limit of the crystal melting point temperature of the crosslinked fluororesin in the sliding layer 1 varies depending on the type of fluororesin, but for example, in the case of PTFE, it may be 325 ° C. or 320 ° C. The temperature may be 310°C. The crystal melting point temperature decreases with the degree of crosslinking of the crosslinked fluororesin. Therefore, when the crystal melting point temperature is below the upper limit, it is possible to suppress a decrease in wear resistance due to insufficient degree of crosslinking. Note that the lower limit of the crystal melting point temperature of the crosslinked fluororesin is, for example, 290°C. When the crystal melting point temperature is equal to or higher than the lower limit, it is possible to suppress a decrease in wear resistance due to a decrease in heat resistance or the like. Note that the "crystalline melting point" refers to the peak melting point temperature measured by a differential scanning calorimeter (DSC) in accordance with JIS-K7121:2012 "Method for Measuring Transition Temperature of Plastics."

The upper limit of the dynamic friction coefficient of the outer surface of the sliding layer 1 may be 0.09 or 0.08. When the dynamic friction coefficient is 0.09 or less, the sliding properties of the laminate 10 can be improved. The lower limit of the coefficient of dynamic friction on the outer surface of the sliding layer 1 is not particularly limited, and may be zero.

Furthermore, as shown in FIGS. 2 and 3, the sliding layer 1 may have a plurality of grooves 3 on the outer surface 9. Since the sliding layer 1 has a plurality of grooves 3 on the outer surface 9, the contact area of the sliding layer 1 with the member to be slid can be reduced. The shape of each groove 3 is not particularly limited, and may be linear or wavy, for example. Further, the arrangement of the plurality of grooves 3 is not particularly limited, and may be arranged in a stripe shape, for example. However, the plurality of grooves 3 may be arranged in a grid pattern as a whole. In the laminate 10, the plurality of grooves 3 are arranged in a lattice pattern as a whole, so that the plurality of grooves 3 extending in the direction along the sliding direction prevent the sliding layer 1 from interfering with the sliding target member. The contact area can be more easily and reliably reduced. Furthermore, by arranging the plurality of grooves 3 in a grid pattern as a whole, when applying lubricant to the outer surface 9 of the sliding layer 1, the lubricant can be applied to a relatively large area in the sliding direction. It is easy to retain it in the plurality of grooves 3 that intersect at an angle. Therefore, the laminate 10 tends to have improved sliding properties. Note that the term "lattice shape" includes a shape in which the linear portions constituting the lattice are divided at one or more places.

When the plurality of grooves 3 are arranged in a lattice shape as a whole, the overall shape of the plurality of grooves 3 may be a square lattice shape. Further, in this case, a plurality of grooves 3 extending in one direction may be arranged parallel to the sliding direction. That is, if the laminate 10 is cylindrical, a plurality of grooves 3 extending in one direction may be arranged in the circumferential direction. According to this configuration, the laminate 10 can easily and reliably reduce the contact area of the sliding layer 1 with the member to be slid by the plurality of grooves 3 arranged parallel to the sliding direction, and The lubricant can easily stay in the plurality of grooves 3 arranged perpendicular to the moving direction.

The average width (w) of the plurality of grooves 3 may be 100 μm or more and 1000 μm or less. When the laminate 10 is used with a lubricant applied to the outer surface of the sliding layer 1, the lower limit of the average width (w) of the plurality of grooves 3 may be 120 μm, or 150 μm. Good too. On the other hand, when the laminate 10 is used with a lubricant applied, the upper limit of the average width (w) may be 350 μm or 250 μm. When the average width (w) is 100 μm or more, the lubricant can be sufficiently retained in each groove 3. On the other hand, when the average width (w) is 1000 μm or less, the effect of improving lubricant retention is promoted, and the wear resistance of the sliding layer 1 can be improved.

The lower limit of the average depth (d) of the plurality of grooves 3 may be 30 μm, 50 μm, or 80 μm. On the other hand, the upper limit of the average depth (d) of the plurality of grooves 3 can be appropriately designed according to the size and shape of the mesh network, which will be described later, and may be 500 μm or 400 μm. , 300 μm. When the average depth (d) is equal to or greater than the lower limit, for example, when the laminate 10 is used with a lubricant applied thereto, it becomes easy to sufficiently retain the lubricant in each groove 3. On the other hand, when the average depth (d) is equal to or less than the upper limit, the wear resistance of the sliding layer 1 can be sufficiently maintained.

The depth of each groove 3 may be substantially uniform, but may be non-uniform. For example, the depth of the bottom of each groove 3 may gradually increase from both ends in the width direction toward the center. The laminate can maintain sufficiently high slidability even when the depths of the grooves 3 are uneven. On the other hand, in the laminate 10, since the depths of the grooves 3 are nonuniform, it is possible to suppress a decrease in the strength of the sliding layer 1 caused by the plurality of grooves 3.

The lower limit of the average interval (r) between the plurality of grooves 3 may be 250 μm, 300 μm, or 400 μm. On the other hand, the upper limit of the average interval (r) between the plurality of grooves 3 may be 3000 μm, 2000 μm, or 1000 μm. When the average interval (r) is 250 μm or more, the width of the protrusions formed between adjacent grooves 3 of the sliding layer 1 is sufficient, and damage to the protrusions due to sliding can be suppressed. On the other hand, since the above-mentioned average interval (r) is 3000 μm or less, the contact area between the sliding layer 1 and the member to be slid can be made sufficiently small, and the laminate 10 can be used with a lubricant applied. In this case, the lubricant can be sufficiently retained on the outer surface of the sliding layer 1.

In addition, in the laminate 10, since the sliding layer 1 has a crosslinked fluororesin as a main component, the surface pressure of the convex portions on the outer surface 9 of the sliding layer 1 may increase; A slight amount of fluororesin powder is generated due to slight abrasion, which actually tends to improve sliding properties.

In particular, it is preferable that the average width (w), average depth (d), and average interval (r) of the plurality of grooves 3 are all within the above ranges. In the laminate 10, the average width (w), average depth (d), and average interval (r) of the plurality of grooves 3 are all within the above ranges, thereby facilitating the sliding properties of the sliding layer 1. And it can definitely be improved.

The lower limit of the average pitch (p) between adjacent grooves 3 may be 400 μm, 500 μm, or 600 μm. On the other hand, the upper limit of the average pitch (p) may be 5900 μm, 2500 μm, or 1500 μm. When the average pitch (p) is 400 μm or more, the width of the convex portions formed between adjacent grooves 3 of the sliding layer 1 is sufficient, and damage to the convex portions due to sliding can be suppressed. On the other hand, since the average pitch (p) is 5900 μm or less, the contact area between the sliding layer 1 and the member to be slid can be made sufficiently small, and the laminate 10 can be used with a lubricant applied. In this case, the lubricant can be sufficiently retained on the outer surface of the sliding layer 1. Note that the "average pitch" refers to the average distance between the center axes of adjacent grooves 3.

Some or all of the plurality of grooves 3 may be independent grooves. According to this configuration, the lubricant can easily be retained in the independent groove, thereby easily improving sliding properties. Moreover, according to this configuration, a decrease in the strength of the sliding layer 1 due to the plurality of grooves 3 can be suppressed.

The lower limit of the ratio of the number of independent grooves to the total number of grooves 3 formed on the outer surface 9 of the sliding layer 1 may be 50%, 70%, or 90%. Good too. When the ratio is equal to or higher than the lower limit, the lubricant retention effect can be easily and reliably increased.

Furthermore, when the plurality of grooves 3 are arranged in a grid pattern as a whole, a plurality of independent grooves may be formed so that the grooves 3 extending in intersecting directions are not connected to each other. If the grooves 3 extending in intersecting directions are connected to each other, an excessive amount of lubricant will remain in this connected portion, and the lubricant will be likely to be unevenly distributed in this connected portion. On the other hand, when the grooves 3 extending in the intersecting directions are not connected, the lubricant can be distributed ubiquitously on the outer surface 9 of the sliding layer 1, thereby easily improving the overall sliding properties. can be increased.

As shown in FIG. 4, the outer surface 9 of the portion of the sliding layer 1 surrounded by the plurality of grooves 3 may be formed into a dome shape. By forming the outer surface 9 of the sliding layer 1 into a dome shape, the contact area of the sliding layer 1 with the member to be slid can be further reduced. Moreover, according to this configuration, as shown in FIG. 4, it is easy to spread the lubricant X over the curved surface portion of the dome-shaped portion 4, so that the effect of improving the slidability by the lubricant X can be easily enhanced. The expression "the outer surface 9 is dome-shaped" means that the outer surface 9 as a whole is curved outwardly in a cross section in the thickness direction, and includes a shape in which a portion of the outer surface 9 has irregularities.

The lower limit of the average thickness of the sliding layer 1 may be 30 μm or 100 μm. On the other hand, the upper limit of the average thickness of the sliding layer 1 may be 1000 μm or 800 μm. When the average thickness is 30 μm or more, the strength of the sliding layer 1 can be improved and the depth of the plurality of grooves 3 can be made sufficiently deep. On the other hand, when the average thickness is 1000 μm or less, it is possible to prevent the thickness from becoming unnecessarily thick. Note that the "average thickness of the sliding layer" refers to the average value of the thickness at arbitrary ten points where the grooves 3 are not formed.

(Base material layer)
The base material layer 2 is composed of fluororesin-impregnated glass cloth. "Fluororesin-impregnated glass cloth" is a glass cloth that is a bundle of glass fibers woven from glass yarns oriented in two orthogonal directions, and is impregnated with a resin material.

The lower limit of the average thickness of the base layer 2 may be 50 μm or 70 μm. By having the average thickness of 50 μm or more, the strength of the base layer 2 can be improved, and the shape of the base layer 2 can be easily maintained. On the other hand, the upper limit of the average thickness of the base material layer 2 may be 150 μm or 120 μm. By having the average thickness of 150 μm or less, it is possible to prevent the thickness from becoming unnecessarily thick.

As the weaving method of the glass cloth, known weaving methods such as plain weave, twill weave, and satin weave can be applied, but from the viewpoint of making the base layer 2 thinner, plain weave may be used.

The upper limit of the density of the glass fibers of the glass cloth may be 5 g/m ³ or 3 g/m ³ . On the other hand, the lower limit of the density may be 1 g/m ³ or 2 g/m ³ . Here, the "density of glass cloth" is a value measured in accordance with JIS-R3420 (2013).

The upper limit of the tensile strength of the glass fibers of the glass cloth may be 10 GPa or 5 GPa. On the other hand, the lower limit of the tensile strength may be 1 GPa or 2 GPa. Here, the "tensile strength of glass fiber" is a value measured in accordance with JIS-R3420 (2013).

The upper limit of the tensile modulus of the glass fibers of the glass cloth may be 200 GPa or 100 GPa. On the other hand, the lower limit of the tensile modulus may be 10 GPa or 50 GPa. Here, the "tensile modulus" is a complex modulus representing the relationship between tensile stress and strain, and is a value measured by a tensile tester.

The upper limit of the maximum elongation rate of the glass fibers of the glass cloth may be 20% or 10%. On the other hand, the lower limit of the maximum elongation rate may be 1% or 3%. Here, the "maximum elongation rate" is a value calculated based on the elongation of the glass fiber at tensile break.

The upper limit of the softening point of the glass fibers of the glass cloth may be 1200°C or 1000°C. On the other hand, the lower limit of the softening point may be 700°C or 800°C. The above softening point means a softening point measured by the ring and ball method specified in JIS-K-7234 (1986). Here, the "softening point of glass fiber" is a value measured in accordance with JIS-R3420 (2013).

The resin impregnated into the fluororesin-impregnated glass cloth is polytetrafluoroethylene, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, or A combination of these may also be used. The resin impregnated into the fluororesin-impregnated glass cloth is polytetrafluoroethylene, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, or By using a combination of these, the durability and heat resistance of the base material layer 2 can be improved.

(Method for manufacturing a laminate according to the first embodiment)
Next, a method for manufacturing the laminate will be described. The method for manufacturing the laminate includes, for example, a step of irradiating a sheet body mainly composed of a fluororesin with ionizing radiation at a temperature higher than the crystal melting point of the fluororesin in a low oxygen atmosphere, and a step of irradiating both sides of the base material layer. and a step of laminating the sheet bodies. Furthermore, the method for manufacturing the laminate may include a step of forming a plurality of grooves on the outer surface of the sheet body after the irradiation step. Note that the step of laminating the sheet bodies may be performed before the irradiation step, between the irradiation step and the groove forming step, or after the groove forming step. It's okay.
In the following manufacturing process, a procedure for performing a step of laminating the sheet bodies after the irradiation step will be described.

<Irradiation process>
In the irradiation step, the fluororesin contained in the sheet body is crosslinked. This improves the mechanical properties, abrasion resistance, adhesion to the base layer 2, etc. of the sheet body.

In the irradiation step, the sheet body is heated to a temperature higher than the crystalline melting point of the fluororesin. The specific heating temperature in the irradiation step is, for example, 270°C or higher when the fluororesin is FEP (crystalline melting point temperature: 270°C), and is 270°C or higher when the fluororesin is PTFE (crystalline melting point temperature: 327°C). If the fluororesin is PFA (crystal melting point temperature: 304 °C or higher and 310 °C or lower), the temperature is 310 °C or higher; if the fluororesin is ETFE (crystal melting point temperature: 270 °C) In this case, the temperature is 270°C or higher. The lower limit of the heating temperature may be 5° C. higher than the crystal melting point temperature. On the other hand, the upper limit of the heating temperature may be 50° C. higher than the crystal melting point temperature, or 20° C. higher than the crystal melting point temperature. By irradiating with ionizing radiation under the above conditions, crosslinking between molecules can be promoted while suppressing cleavage of the main chain of the fluororesin. Furthermore, the formation of chemical bonds between the fluororesin and the base material layer 2 can be promoted.

The upper limit of the oxygen concentration in the irradiation step may be 100 ppm, 10 ppm, or 5 ppm. When the oxygen concentration is below the upper limit, decomposition of the fluororesin and oxidation of the base layer 2 can be suppressed.

Examples of the ionizing radiation include gamma rays, electron beams, X-rays, neutron beams, and high-energy ion beams. Further, the lower limit of the irradiation dose of ionizing radiation may be 10 kGy, 70 kGy, or 200 kGy. On the other hand, the upper limit of the irradiation dose may be 2000 kGy, 1200 kGy, or 400 kGy. When the irradiation dose is equal to or higher than the lower limit, the crosslinking reaction of the fluororesin can proceed sufficiently. On the other hand, when the above-mentioned irradiation dose is below the above-mentioned upper limit, scission of the main chain of the fluororesin can be suppressed.

<Process of laminating sheet bodies>
In the step of laminating the sheet bodies, after the sheet body mainly composed of fluororesin is crosslinked by the irradiation step, the sheet bodies are laminated on both sides of the base material layer. The method for laminating the sheet body on the base material layer is not particularly limited, and includes, for example, a method of thermocompression bonding the sheet body and the base material layer.

Before the step of laminating the sheet bodies, a surface treatment may be performed on the surface of the base material layer on which the sheet bodies are laminated. Examples of the surface treatment include roughening by plasma treatment, sandblasting treatment, etching treatment, electrolytic polishing treatment, and the like.

The method for manufacturing the fluororesin-impregnated glass cloth, which is the base material layer, includes, for example, a step of impregnating the inside of the glass cloth with a composition containing a fluororesin as a main component, and a step of heating the impregnated composition. Be prepared.

In the above impregnating step, methods for impregnating the inside of the glass cloth with a composition containing a fluororesin as a main component include, for example, applying the above composition to the surface of the glass cloth, and immersing the glass cloth in the above composition. Examples include methods.

In the heating step, the impregnated composition is heated. The heating step corresponds to a baking step in which the impregnated composition dries and hardens. The lower limit of the temperature in the heating step is preferably 150°C, more preferably 200°C. On the other hand, the upper limit of the temperature in the heating step is preferably 600°C, more preferably 500°C.

<Process of forming grooves>
In the step of forming the grooves, a plurality of grooves are formed on the outer surface of the sheet body. Through this process of forming grooves, the sheet body becomes a sliding layer having a plurality of grooves on the outer surface. The method for forming the plurality of grooves on the outer surface of the sheet body is not particularly limited, but may be a hot press method. Specifically, in the step of forming the grooves, the outside of the sheet body is heated to a temperature higher than the glass transition temperature of the fluororesin, preferably the sheet body is heated to a temperature higher than the glass transition temperature of the fluororesin. A mold or mesh net having an inverted groove shape on the surface is pressed. In the step of forming the grooves, the shape of the outer surface of the resulting sliding layer can be adjusted by adjusting the surface shapes of the mold and the mesh net. In the step of forming the grooves, the average width, average depth, and average pitch between adjacent grooves of the plurality of grooves may be adjusted within the above-mentioned ranges. The pressing temperature in the step of forming the grooves may be, for example, 200° C. or more and 300° C. or less, although it depends on the glass transition temperature of the fluororesin. The pressing time in the step of forming the grooves can be, for example, 10 minutes or more and 60 minutes or less. The press pressure in the step of forming the grooves can be, for example, 10 kg/cm ² or more and 30 kg/cm ² or less.

Further, in the step of forming the grooves, the average width of the plurality of grooves may be 100 μm or more and 1000 μm or less, the average depth may be 30 μm or more and 500 μm or less, and the average interval may be 250 μm or more and 3000 μm or less. Furthermore, some or all of the plurality of grooves may be independent grooves, and the plurality of grooves may be arranged so as to extend in intersecting directions and form a lattice shape as a whole.

The laminate of the first embodiment has excellent sliding properties and wear resistance.

[Second embodiment]
The laminate according to the second embodiment further includes an adhesive layer directly laminated between the surface of the base layer of the laminate according to the first embodiment and the surface of the sliding layer.

FIG. 5 is a schematic cross-sectional view showing a laminate 20 according to the second embodiment. The laminate 20 in FIG. 5 includes a base layer 2, an adhesive layer 5 laminated on both sides of the base layer 2, and a sliding layer 1 laminated on the surface of the adhesive layer 5. The laminate 20 is a five-layer body including a base material layer 2, two sliding layers 1, and two adhesive layers 5. Note that the base material layer 2 and the sliding layer 1 are the same as those in the first embodiment, so the same numbers are given and explanations are omitted.

(Adhesive layer)
The main component of the adhesive layer 5 is the same fluororesin as the material forming the sliding layer 1 described above. Examples of the fluororesin include tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene/hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-ethylene copolymer (ETFE). . Since the adhesive layer 5 mainly contains a tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene/hexafluoropropylene copolymer, a tetrafluoroethylene-ethylene copolymer, or a combination thereof, The adhesion and heat resistance of layer 5 can be improved.

The lower limit of the content of the fluororesin in the adhesive layer 5 may be 60% by mass, 80% by mass, 90% by mass, or 100% by mass.

The lower limit of the average thickness of the adhesive layer 5 may be 0.1 μm or 1 μm. On the other hand, the upper limit of the average thickness of the adhesive layer 5 may be 20 μm or 10 μm. When the average thickness of the adhesive layer 5 is 0.1 μm or more, the adhesive strength between the base layer 2 and the sliding layer 1 via the adhesive layer 5 can be sufficiently improved. On the other hand, since the average thickness of the adhesive layer 5 is 20 μm or less, it is possible to prevent the dimensions of the laminate 20 from becoming unnecessarily large.

(Method for manufacturing a laminate according to the second embodiment)
The method for manufacturing a laminate according to the second embodiment includes, for example, a step of laminating an adhesive layer on both sides of a base material layer, and a step of laminating adhesive layers on both sides of a base material layer, and applying a fluororesin-based sheet body to a temperature higher than the crystal melting point of the fluororesin at a low temperature. The method includes a step of irradiating ionizing radiation in an oxygen atmosphere, and a step of laminating the sheet body on the surface of the adhesive layer. Furthermore, the method for manufacturing the laminate may include a step of forming a plurality of grooves on the outer surface of the sheet body after the irradiation step. There is no special step of laminating adhesive layers on both sides of the base material layer, and the lamination of the sheet body mainly composed of fluororesin and the lamination of the adhesive layer may be performed simultaneously. Further, the laminating step may be performed before the irradiating step, between the irradiating step and the groove forming step, or after the groove forming step. .

<Process of laminating adhesive layer>
In the step of laminating adhesive layers, adhesive layers are laminated on both sides of the base material layer. The method of laminating the adhesive layer is not particularly limited, and the adhesive layer can be laminated by applying a composition for adhesive layer containing a fluororesin as a main component to both surfaces of the base layer using a well-known coating method.

<Process of laminating sheet bodies>
In the step of laminating the sheet bodies, the sheet bodies serving as the sliding layer are laminated on the surface of the adhesive layer. The method for laminating the sheet body on the surface of the adhesive layer is not particularly limited, and includes, for example, a method of thermocompression bonding the sheet body and the adhesive layer. Note that before the step of laminating the sheet bodies that will become the sliding layer, the adhesive surface of the sheet body to the adhesive layer is roughened by, for example, plasma treatment, sandblasting treatment, etching treatment, electrolytic polishing treatment, etc. Good too.

<Irradiation process>
In the irradiation step, the fluororesin contained in the sheet body is crosslinked. The irradiation step is the same as the irradiation step described in the method for manufacturing a laminate according to the first embodiment, so a description thereof will be omitted.

<Process of forming grooves>
In the step of forming the grooves, a plurality of grooves are formed on the outer surface of the sheet body. The process of forming the grooves is the same as the process of forming the grooves described in the method for manufacturing the laminate according to the first embodiment, so the description thereof will be omitted.

The laminate of the second embodiment has excellent sliding properties and abrasion resistance, and can further improve the adhesiveness between the base layer and the sliding layer.

[Other embodiments]
The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the configuration of the above-described embodiments, but is indicated by the claims for utility model registration, and includes all changes within the meaning and scope equivalent to the claims for utility model registration. It is intended that

In the above embodiment, the sliding layer has a plurality of grooves extending in a direction crossing the outer surface and arranged in a grid pattern as a whole, but the shape of the outer surface of the sliding layer is not limited to this. For example, the sliding layer may have a plurality of recesses having the same shape in plan view on the outer surface, and the plurality of recesses may be arranged on the outer surface in a plurality of rows at equal intervals in each row. The sliding layer has a plurality of recesses having the same shape in plan view on the outer surface, and the plurality of recesses are arranged on the outer surface in a plurality of rows and at equal intervals in each row. Since the contact area with the member to be slid can be reduced, and the lubricant can be easily retained in the plurality of recesses, the slidability can be further improved.

The shape of the plurality of recesses formed on the outer surface of the sliding layer is not particularly limited, and may be, for example, a square, a rectangle, a parallelogram (diamond), a trapezoid, a polygon (triangle, hexagon, etc.), or a circle. , may be an ellipse.

The average maximum diameter in the row direction of the plurality of recesses in plan view is 100 μm or more and 1000 μm or less, the average interval in the row direction of the plurality of recesses in plan view is 250 μm or more and 3000 μm or less, and the average depth of the plurality of recesses is The length may be 30 μm or more and 500 μm or less. The average maximum diameter of the plurality of recesses in the row direction in plan view, the average interval of the plurality of recesses in the row direction in plan view, and the average depth of the plurality of recesses are within the above ranges, so that the sliding layer Since the contact area with the member to be slid can be made smaller and the lubricant can be more easily retained in the plurality of recesses, the slidability can be further improved.

The lower limit of the average interval in the row direction perpendicular to the column direction in a plan view of the plurality of recesses may be 50 μm or 100 μm. The upper limit of the average interval in the row direction of the plurality of recesses in plan view may be 1000 μm or 500 μm. When the average interval in the row direction of the plurality of recesses in plan view is within the above range, the surface pressure applied to the outer surface of the sliding layer can be maintained uniformly. "Average spacing in the row direction of recesses in a plan view" is the value obtained by excluding the largest five and the smallest five of the 20 adjacent spacings in the same row in a plan view of a plurality of recesses. means the average value of

FIG. 6 is a schematic plan view showing a modification of the sliding layer. As shown in FIG. 6, the outer surface 15 of the sliding layer 11 has a plurality of diamond-shaped recesses 13 formed in a plan view. The plurality of rhombic recesses 13 are arranged in a plurality of rows on the outer surface 15 at equal intervals in each row.

FIG. 7 is a schematic plan view showing another modification of the sliding layer. As shown in FIG. 7, the outer surface 18 of the sliding layer 16 has a honeycomb structure in which a plurality of regular hexagonal recesses 17 are formed in a plan view. The plurality of regular hexagonal recesses 17 are arranged in a plurality of rows on the outer surface 18 at equal intervals in each row.

The plurality of recesses having the same shape in plan view on the outer surface of the sliding layer are formed by heating the sheet body mainly composed of the fluororesin and then applying pressure to the outer surface of the sheet body with a mold. be able to.

The laminate may be a multilayer body that further includes layers other than the sliding layer and the base material layer, as long as the sliding layer forms the outermost layer.

Hereinafter, the present disclosure will be explained in more detail with reference to Examples, but the present disclosure is not limited to these Examples.

<Laminated body No. 1~No. 7＞
[Preparation of base material layer]
A plain-woven fluororesin-impregnated glass cloth having an average thickness of 80 μm and serving as a base material layer was prepared according to the following procedure. The above-mentioned fluororesin-impregnated glass cloth was prepared by dipping a plain-woven glass cloth with an average thickness of 55 μm, a mass of 47 g/m ² , a vertical number of 60 pieces/25 mm, and a horizontal number of 46 pieces/25 mm into a fluororesin dispersion, and then pulling it up and drying it. It was manufactured by repeating sintering many times.

[Preparation of sliding layer]
A cross-linked fluororesin sheet serving as a sliding layer was prepared in the following manner.
First, a crosslinked fluororesin sheet shown in Table 1 made of a fluororesin and having an average thickness of 100 μm was obtained. Next, this fluororesin sheet was heated to 340°C in a low-oxygen atmosphere with an oxygen concentration of 5 ppm or less in a continuous heating irradiation furnace, and irradiated with an electron beam using an electron beam accelerator manufactured by NHV Corporation. . The irradiation conditions were an acceleration voltage of 500 kV and an irradiation dose of 300 kGy. As a result, a crosslinked fluororesin sheet for a sliding layer having an average thickness of 100 μm was obtained.

[Preparation of laminate]
The obtained No. 1~No. No. 7 was coated on both sides of the base material layer made of fluororesin-impregnated glass cloth. 1~No. The crosslinked fluororesin sheets of No. 7 were laminated by thermocompression bonding under the conditions of a roll temperature of 350° C. and a nip pressure of 0.5 MPa. Also, No. 2 and no. Regarding No. 5, an adhesive layer having an average thickness of 25 μm and made of PFA shown in Table 1 was placed between the surface of the base material layer made of fluororesin-impregnated glass cloth and the surface of the crosslinked fluororesin sheet. Then, the base material layer, the adhesive layer, and the crosslinked fluorine sheet were simultaneously thermocompression bonded under the conditions of a roll temperature of 350° C. and a nip pressure of 0.5 MPa, thereby laminating five layers at the same time.

[evaluation]
The obtained No. 1~No. Regarding the laminate No. 7, the critical PV and interfacial peel force were evaluated. No. 1~No. Table 1 shows the evaluation results for the laminate No. 7.

(Limit PV)
The limit PV was measured according to the following procedure, and No. 1~No. The wear resistance of the laminate No. 7 was evaluated.
The conditions were that low viscosity oil was applied, the pressure was kept at a constant value of 0.2 MPa, and the speed was increased.
(Measuring method)
Measurements were made in accordance with JIS-K7218:1986 method A (ring-on-disk thrust friction test) under the following conditions.
Ring-shaped mating material: S45C
Ring dimensions: outer diameter 25.6mm, inner diameter 20mm
Ring-shaped counterpart material arithmetic mean roughness Ra: 0.28μm
Test equipment: “EFM-III 1010” manufactured by A&D Co., Ltd.
Pressure: 0.2MPa (constant)
Speed: 10m/min, 15m/min, 24m/min, 38m/min, 62m/min, 96m/min

(Interfacial peeling force)
The interfacial peel force was measured according to the following procedure, and No. 1~No. The adhesion between the base layer and the sliding layer in the laminate No. 7 was evaluated.
The interfacial peel force was measured in accordance with JIS-K6854-2 (180 degree peel test) under the following conditions.
Test equipment: “UTC-5T” manufactured by A&D Co., Ltd.
Test environment: 23℃±2℃, 50%RH±10%RH
Test piece shape: width 25mm

As shown in Table 1, the No. ．． 1~No. The laminate No. 7 had good limit PV value and interfacial peeling force.

<Sliding sheet No. 8~No. 12>
No. The grooves shown in FIG. 3 were formed on the outer surface of the sliding sheet No. 1 using meshes of the sizes shown in Table 2.

[evaluation]
The obtained No. 8~No. The coefficient of dynamic friction was evaluated for 12 sliding sheets. No. 8~No. Table 2 shows the evaluation results for the 12 sliding sheets.

(dynamic friction coefficient)
The coefficient of dynamic friction was measured by the reaction torque generated in the cylinder, which is the ring-shaped counterpart material, in the measurement of the limit PV described above. The dynamic friction coefficient was an average value at speeds of 50 mm/min to 750 mm/min.

As shown in Table 2, No. 2 has a plurality of grooves on the outer surface. 8~No. The sliding sheet No. 12 had a small coefficient of dynamic friction, and good results were obtained.

As described above, the laminate of the present disclosure has excellent sliding properties and wear resistance, so it can be suitably used for bearings, engine piston skirts, pump sliding parts, sliding packings, sliding plates for OA equipment, etc. .

1, 11, 16 Sliding layer 2 Base layer 3 Groove 4 Dome-shaped portion 5 Adhesive layer 9, 15, 18 Outer surface of sliding layer 10, 20 Laminated body 13, 17 Recess X Lubricant w Width d Depth r interval p pitch

Claims (10)

a base material layer;
a sliding layer that is directly or indirectly laminated on a part or all of the surface of the base layer and that has a crosslinked fluororesin as a main component;
A laminate in which the base layer is made of fluororesin-impregnated glass cloth. The laminate according to claim 1, further comprising an adhesive layer laminated directly between the surface of the base layer and the surface of the sliding layer. The sliding layer has a plurality of grooves on the outer surface,
The average width of the plurality of grooves is 100 μm or more and 1000 μm or less, the average depth is 30 μm or more and 500 μm or less, and the average interval is 250 μm or more and 3000 μm or less,
Claim 1 or Claim 2, wherein some or all of the plurality of grooves are independent grooves, and the plurality of grooves extend in intersecting directions and are arranged in a grid pattern as a whole. The described laminate. The sliding layer has a plurality of recesses having the same shape in plan view on the outer surface,
The plurality of recesses are arranged on the outer surface in a plurality of rows and at equal intervals in each row,
The average maximum diameter of the plurality of recesses in the column direction in plan view is 100 μm or more and 1000 μm or less,
The average interval in the column direction of the plurality of recesses in plan view is 250 μm or more and 3000 μm or less,
The laminate according to claim 1 or 2, wherein the average depth of the plurality of recesses is 30 μm or more and 500 μm or less. The laminate according to claim 1 or 2, wherein the average thickness of the base material layer is 50 μm or more and 150 μm or less. The laminate according to claim 1 or 2, wherein the average thickness of the sliding layer is 30 μm or more and 1000 μm or less. The laminate according to claim 1 or 2, wherein the fluororesin-impregnated glass cloth has a plain weave structure. The resin impregnated into the fluororesin-impregnated glass cloth is polytetrafluoroethylene, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, or The laminate according to claim 1 or 2, which is a combination of these. The sliding layer may be crosslinked polytetrafluoroethylene, crosslinked tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, crosslinked tetrafluoroethylene/hexafluoropropylene copolymer, crosslinked tetrafluoroethylene-ethylene copolymer, or a combination thereof. The laminate according to claim 1 or 2, comprising as a main component. 3. The adhesive layer according to claim 2, wherein the adhesive layer mainly contains a tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene/hexafluoropropylene copolymer, a tetrafluoroethylene-ethylene copolymer, or a combination thereof. laminate.

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