Urethane molded body and sealing member for machine tool

Abstract

The present invention provides a urethane molded body that is less susceptible to degradation by amine compounds, and a sealing member for machine tools that includes an elastic member made of such a urethane molded body. [Solution] A urethane molded article containing polyurethane and ZSM-5 type zeolite. A sealing member for a machine tool having an elastic member and a support member, wherein the elastic member is made of a cured product of a thermosetting urethane composition, and the thermosetting urethane composition contains a polyol component, an isocyanate component, a crosslinking agent, and ZSM-5 type zeolite.

Description

【Technical Field】 【0001】 The present invention relates to a urethane molded body and a sealing member for a machine tool. 【Background Art】 【0002】 Machine tools such as lathes and machining centers are the most basic mechanical devices widely used in the manufacturing industry. For these machine tools, various sealing members, such as lip seals, slide seals, telescopic seals, cover seals, etc., are used to protect drive mechanisms and the like from chips and cutting oil agents (including coolants). 【0003】 As a sealing member for a machine tool, for example, a sealing member provided with a support member and an elastic member is known. As such a sealing member, one provided with an elastic member made of urethane elastomer is known (see, for example, Patent Document 1). 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 International Publication No. 2017 / 110275 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 As described above, the sealing member for a machine tool is a member for protecting the drive mechanism from the cutting oil agent, and during use, the elastic member is exposed to the cutting oil agent. The elastic member exposed to the cutting oil agent may deteriorate prematurely depending on the type of the cutting oil agent. 【Means for Solving the Problems】 【0006】 The inventors investigated the aforementioned premature degradation and found that elastic members made of urethane elastomer are prone to degradation when exposed to cutting fluids containing high concentrations of amine compounds. Furthermore, the inventors conducted further investigations and found that urethane molded articles of a specific composition are less prone to degradation even when in contact with amine compounds, thus completing the present invention. 【0007】 (1) The urethane molded article of the present invention contains polyurethane and ZSM-5 type zeolite. Degradation of urethane molded articles by amine compounds is thought to occur when the amine compounds attack and decompose the urethane bonds. The above-mentioned urethane molded article contains ZSM-5 type zeolite, which can capture amine compounds. Therefore, the above-mentioned urethane molded article is less susceptible to degradation even when in contact with amine compounds. 【0008】 (2) In the urethane molded article described in (1) above, the preferred average particle size of the ZSM-5 type zeolite is 80 nm or more and 700 nm or less. (3) In the urethane molded article of (1) or (2) above, the preferred ZSM-5 type zeolite is the Ca ion type. (4) In any of the urethane molded articles described in (1) to (3) above, the preferred content of the ZSM-5 type zeolite is 0.4% by mass or more and 2.1% by mass or less relative to the polyurethane. 【0009】 (5) The machine tool sealing member of the present invention is a machine tool sealing member having an elastic member and a support member, The above elastic member is made from a cured product of a thermosetting urethane composition. The above thermosetting urethane composition contains a polyol component, an isocyanate component, a crosslinking agent, and a ZSM-5 type zeolite. Because the elastic component of this machine tool seal is made from a cured product of a thermosetting urethane composition containing ZSM-5 type zeolite, it is less prone to deterioration even when exposed to cutting fluids containing amine compounds. 【0010】 (6) In the machine tool sealing member described in (5) above, the preferred average particle size of the ZSM-5 type zeolite is 80 nm or more and 700 nm or less. (7) In the machine tool sealing member described in (5) or (6) above, the preferred ZSM-5 type zeolite is the Ca ion type. (8) In any of the machine tool sealing members described in (5) to (7) above, the preferred content of the ZSM-5 type zeolite is 0.4% by mass or more and 2.1% by mass or less, relative to the total amount of the polyol component, the isocyanate component, and the crosslinking agent. 【0011】 (9) In the sealing member for machine tools described in (5) above, a preferred sealing member for machine tools is: The above ZSM-5 type zeolite is of the Ca ion type, The average particle size of the above ZSM-5 type zeolite is 90 nm or more and 120 nm or less, and The content of the above ZSM-5 type zeolite is 0.8% by mass or more and 1.2% by mass or less, relative to the total amount of the above polyol component, the above isocyanate component, and the above crosslinking agent. [Effects of the Invention] 【0012】 The urethane molded article of the present invention is less susceptible to degradation by amine compounds. The machine tool sealing member of the present invention has an elastic member made of the above-mentioned urethane molded body, and is less prone to deterioration even when exposed to cutting fluids contained in amine compounds. [Brief explanation of the drawing] 【0013】 [Figure 1A] This is a perspective view showing an example of a sealing member for a machine tool according to an embodiment of the present invention. [Figure 1B] Figure 1A is a side view of the machine tool sealing member shown. [Figure 2] Figure 1A is a cross-sectional view showing the machine tool sealing member attached to a machine tool. [Figure 3A]It is a perspective view showing another example of the seal member for a machine tool according to an embodiment of the present invention. [Figure 3B] It is a side view of the seal member for a machine tool shown in FIG. 3A. [Figure 4] It is a cross-sectional view showing a state where the seal member for a machine tool shown in FIG. 3A is attached to the machine tool. [Figure 5] It is a perspective view showing still another example of the seal member for a machine tool according to an embodiment of the present invention. [Figure 6] It is a graph showing the ratio of the change amount of the elongation at break (EB) due to immersion in a cutting oil agent. [Figure 7A] It is a photograph of a test piece cut out from the urethane sheet A of Test Example 1 after being immersed in a cutting oil agent for 120 hours. [Figure 7B] It is a photograph of a test piece cut out from the urethane sheet A of Test Example 1 after being immersed in a cutting oil agent for 150 hours. [Figure 8A] It is a photograph of a test piece cut out from the urethane sheet B of Test Example 2 after being immersed in a cutting oil agent for 120 hours. [Figure 8B] It is a photograph of a test piece cut out from the urethane sheet B of Test Example 2 after being immersed in a cutting oil agent for 150 hours. [Figure 9A] It is a photograph of a test piece cut out from the urethane sheet C of Test Example 3 after being immersed in a cutting oil agent for 120 hours. [Figure 9B] It is a photograph of a test piece cut out from the urethane sheet C of Test Example 3 after being immersed in a cutting oil agent for 150 hours. [Figure 10] It is a photograph of a test piece cut out from the urethane sheet D of Test Example 4 after being immersed in a cutting oil agent for 150 hours. [Figure 11A] It is a photograph of a test piece cut out from the urethane sheet E of Test Example 5 after being immersed in a cutting oil agent for 120 hours. [Figure 11B] It is a photograph of a test piece cut out from the urethane sheet E of Test Example 5 after being immersed in a cutting oil agent for 150 hours. 【MODE FOR CARRYING OUT THE INVENTION】 【0014】 Embodiments of the present invention will be described below. A sealing member for a machine tool according to an embodiment of the present invention comprises an elastic member and a support member, wherein the elastic member is made of a urethane molded body according to an embodiment of the present invention. Therefore, this specification will first describe the sealing member for machine tools with reference to the drawings. Next, it will describe the urethane molded body that constitutes the elastic member. 【0015】 (First Embodiment) As shown in Figures 1A and 1B, the machine tool sealing member 10 of the first embodiment comprises a support member 11 and an elastic member 21. The elastic member 21 is a flat, plate-shaped member with elasticity. The elastic member 21 is made of a urethane molded body. This urethane molded body is a cured product of a thermosetting urethane composition. 【0016】 The support member 11 has the role of attaching the elastic member 21 to the machine tool. The support member 11 is an L-shaped member in side view, and has a flat plate-shaped support portion 12 having a support surface 11a facing the front surface 21a of the elastic member 21, and a flat plate-shaped protective portion 13 erected on the side of the support portion 12 opposite to the support surface 11a. The support surface 11a of the support member 11 is joined to the front surface 21a of the elastic member 21 via an adhesive layer 31. 【0017】 As shown in Figure 2, the machine tool sealing member 10 is attached to the mounting portion 35 provided on the machine tool. The elastic member 21 is a flat plate-shaped member in its natural state before being attached to the machine tool. The elastic member 21 consists of a fixing portion 22 that is sandwiched between the mounting portion 35 and the support surface 11a of the support member 11 when the machine tool sealing member 10 is attached to the machine tool, and a lip portion 23 that is not sandwiched between the mounting portion 35 and the support surface 11a. The lip portion 23 includes an edge portion 24 and is bendable. Therefore, the distance L2 from the side surface 21c on the edge portion 24 side to the opposite side surface of the elastic member 21 is longer than the distance L1 in the same direction of the support surface 11a of the support member 11. Furthermore, the machine tool sealing member 10 is provided with a plurality of bolt holes 32 for attaching the machine tool sealing member 10 to the machine tool. The bolt holes 32 are provided so as to penetrate the support member 11 and the elastic member 21. 【0018】 As described above, the support member 11 is equipped with a protective portion 13. Therefore, the machine tool sealing member 10 can protect the front surface 21a of the elastic member 21 from chips during use. As a result, damage to the elastic member 21 due to impact with chips during use can be suppressed. As the support member 11 comprising the support portion 12 and the protective portion 13, for example, a bent metal plate can be used. In the support member 11, the bending angle θ1 of the protective portion 13 with respect to the support portion 12 is not particularly limited, but is usually around 80° to 150°. 【0019】 The machine tool sealing member 10 is used by being attached to the machine tool in a predetermined orientation. As shown in Figure 2, the machine tool sealing member 10 is attached to the machine tool mounting portion 35 using a bolt 33 and a nut 34 such that the elastic member 21 is sandwiched between the machine tool mounting portion 35 and the support member 11. At this time, the machine tool sealing member 10 is attached to the machine tool such that the lip portion 23 of the elastic member 21 is curved toward the opposite side of the mounting portion 35 of the machine tool, and the edge portion 24 of the elastic member 21 is in contact with the sliding surface 36 of the machine tool. The machine tool sealing member 10, which is attached to a machine tool, has an elastic member 21 with an edge portion 24 that slides on the sliding surface 36 of the machine tool, preventing cutting fluid and chips from entering the drive mechanism of the machine tool, etc. 【0020】 The machine tool sealing member 10 has the above-described configuration, and the entire lip portion 23 can deform little by little, so the contact pressure between the edge portion 24 and the sliding surface 36 does not change easily during use (when it is in sliding contact with the sliding surface 36 of the machine tool). Therefore, the edge portion 24 is less prone to wear. Accordingly, the machine tool sealing member 10 can maintain good sealing performance over a long period of time. 【0021】 Let me explain this a little further. The sliding surface 36 of a machine tool typically has undulations (irregularities). Therefore, the distance from the mounting portion 35 of the machine tool (for example, the bolt hole 35a for fixing the machine tool seal member 10) to the sliding surface 36 is not constant. When the edge portion 24 of the machine tool seal member 10 slides on the sliding surface 36, the contact pressure of the edge portion 24 usually changes in accordance with the change in the distance from the mounting portion 35 of the machine tool to the sliding surface 36. On the other hand, when the machine tool sealing member 10 has an elastic member 21 that slides on the sliding surface 36, the entire lip portion 23 of the elastic member 21 deforms little by little (the curvature of the entire lip portion changes), thereby absorbing the undulation of the sliding surface 36 and suppressing fluctuations in the contact pressure between the edge portion 24 and the sliding surface 36. 【0022】 The machine tool sealing member 10 has an edge portion 24 on one side sandwiched between the back surface 21b and the side surface 21c of the elastic member 21. When the lip portion 23 of the elastic member 21 is curved and the edge portion 24 is brought into contact with the sliding surface 36 of the machine tool, the portion of the back surface 21b of the elastic member 21 near the edge portion 24 also comes into contact with the sliding surface 36. In other words, the machine tool sealing member 10 has surface contact between the elastic member 21 (lip portion 23) and the sliding surface 36 of the machine tool. Therefore, the machine tool sealing member 10 has superior sealing performance compared to the case where the two are in line contact. 【0023】 (Second Embodiment) Figure 3A is a perspective view showing a machine tool sealing member according to the second embodiment. Figure 3B is a side view of Figure 3A. In Figures 3A and 3B, the same reference numerals are used for components that are the same as those in the machine tool sealing member of the first embodiment. 【0024】 The machine tool sealing member 20 according to the second embodiment, as shown in Figures 3A and 3B, is further provided with a bending assist member 41 on the back surface 21b side of the elastic member 21, in addition to the machine tool sealing member 10 of the first embodiment. The bending support member 41 has a flat main body portion 42 and a flat support portion 43. The support portion 43 extends diagonally from the lower end of the main body portion 42 toward the curved side (support member 11 side) of the elastic member 21 (lip portion 23). The support portion may also be curved. 【0025】 The main body portion 42 of the bending assist member 41 is joined to a part of the back surface 21b of the elastic member 21 via an adhesive layer 38. As the bending auxiliary member 41 comprising a main body portion 42 and an auxiliary portion 43, for example, a bent metal plate can be used. In the bending auxiliary member 41, the bending angle θ2 of the auxiliary portion 43 relative to the main body portion 42 is not particularly limited, but is usually between 15° and 60°. 【0026】 The elastic member 21 that constitutes the machine tool sealing member 20 is a flat plate-shaped member in its natural state before being joined to the main body 42 of the bending assist member 41. Upon joining with the bending assist member 41, the elastic member 21 maintains a curved state, and in this state becomes the elastic member that constitutes the machine tool sealing member 20. 【0027】 As shown in Figure 4, the machine tool sealing member 20 is attached to the machine tool using bolts 33 and nuts 34 such that the bending assist member 41, the elastic member 21, and the support member 11 are positioned in that order from the mounting portion 35 side of the machine tool. The machine tool sealing member 20 is equipped with a bending assist member 41, making it suitable for mounting to a machine tool without incorrect mounting orientation. In the machine tool sealing member 20, the curvature of the lip portion 23 of the elastic member 21 is supported by the curvature assist member 41. Therefore, the machine tool sealing member is less likely to bend over (inverted lip portion 23 of the elastic member 21) during use. However, the front surface 43a of the assist member 43 and the back surface 21b of the elastic member 21 do not necessarily have to be in contact during use. 【0028】 The machine tool sealing member 20 is more suitable for preventing cutting fluid from entering between the elastic member 21 and the bending assist member 41 (main body portion 42) because the elastic member 21 and the bending assist member 41 (main body portion 42) are joined via an adhesive layer 38. 【0029】 (Third embodiment) Figure 5 is a perspective view showing a sealing member for a machine tool according to the third embodiment. In Figure 5, the same reference numerals are used for the same components as those in the sealing member for a machine tool of the first embodiment. 【0030】 The machine tool sealing member 30 according to the third embodiment has a different shape for the support member 51 compared to the machine tool sealing members 10 and 20 of the first and second embodiments. The support member 51 is a flat plate-shaped member and does not have a protective part. It consists only of the support part 52. Such a support member 51 can also be used as a support member for a machine tool sealing member according to an embodiment of the present invention. 【0031】 (Other embodiments of sealing members for machine tools) In the machine tool sealing members according to the first to third embodiments, the support member and the elastic member, and the elastic member and the bending assist member are joined via an adhesive layer. However, in the machine tool sealing members according to the embodiments of the present invention, the support member and the elastic member, and the elastic member and the bending assist member do not necessarily need to be joined via an adhesive layer; they may simply be physically in close contact. In this case, the support member, the elastic member, and the bending assist member can each be replaced separately. 【0032】 In the machine tool sealing member according to the embodiment of the present invention, the machine tool sealing member of the second embodiment may include a flat plate-shaped support member as a support member, similar to the support member of the machine tool sealing member of the third embodiment. 【0033】 In the sealing member for a machine tool according to an embodiment of the present invention, the flat elastic member is not limited to a perfect rectangular parallelepiped, but may have a shape such as a chamfered edge or a rounded edge. Furthermore, the elastic member may have a cross-sectional shape (shape of the plane perpendicular to the longitudinal direction) that tapers continuously or intermittently towards the edge (thickness decreases). 【0034】 Next, the constituent components of the above-mentioned sealing member for machine tools will be described. (Support member) The above-mentioned support member is a component for attaching the above-mentioned elastic member to a machine tool. The material of the support member described above is generally suitable to be a metal material such as steel or aluminum, in terms of durability and strength. However, the material of the support member may also be ceramic or rigid plastic. Furthermore, the materials used for the support members may include untreated steel plates, steel plates with surface treatments such as zinc phosphate treatment, chromate treatment, or rust-preventive resin treatment, or elastic metal plates such as phosphor bronze or spring steel. The support member may be surface-treated with a primer to improve its compatibility with the adhesive layer interposed between it and the surface of the elastic member. Furthermore, the surface of the support member (particularly the area in contact with the elastic member via the adhesive layer) may be roughened to improve adhesion through an anchoring effect. 【0035】 (Elastic member) The above-mentioned elastic member is a member that slides against the sliding surface of the machine tool. The edge portion of the elastic member contacts the sliding surface of the machine tool. The elastic member described above is made of a urethane molded body according to an embodiment of the present invention. The above-mentioned urethane molded article is a cured product of a predetermined thermosetting urethane composition. The above-mentioned thermosetting urethane composition is a composition that hardens upon heating. The above thermosetting urethane composition contains a polyol component, an isocyanate component, a crosslinking agent, and a ZSM-5 type zeolite. The crosslinking agent also includes a chain extender. 【0036】 The polyol component mentioned above is not particularly limited and includes, for example, polyester polyols, polyether polyols, polycaprolactone polyols, and the like. The polyol described above preferably has a number-average molecular weight of 1000 to 3000. This is because it is more suitable for preventing the intrusion of chips, cutting fluids, and the like. The above number-average molecular weight is a measurement value converted to polystyrene equivalent, obtained by GPC (gel permeation chromatography). 【0037】 Examples of the above-mentioned polyester polyols include those obtained by reacting a dicarboxylic acid and a glycol according to a conventional method. Examples of the dicarboxylic acids mentioned above include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid; aliphatic dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid; oxycarboxylic acids such as oxybenzoic acid; and ester-forming derivatives thereof. Among these, adipic acid is preferred due to its good abrasion resistance. 【0038】 Examples of the glycols mentioned above include aliphatic glycols such as ethylene glycol, 1,4-butanediol, diethylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, and triethylene glycol; alicyclic glycols such as 1,4-cyclohexanedimethanol; aromatic diols such as p-xylenediol; and polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Aliphatic glycols are preferred among the glycols, and ethylene glycol and 1,4-butanediol are more preferred. Polyester polyols, which are reaction products of dicarboxylic acids and glycols, have a linear structure, but they may also be branched polyesters using ester-forming components with a valent or higher ester ratio. 【0039】 Examples of the polyether polyols mentioned above include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polyalkylene glycols such as copolymers thereof. Among these, polytetramethylene glycol is preferred due to its good abrasion resistance. Examples of the polycaprolactone polyols mentioned above include those obtained by ring-opening addition of ε-caprolactone using a low molecular weight glycol as an initiator in the presence of a catalyst. 【0040】 The above polyol components may be used individually or in combination of two or more. Polyester polyols are preferred as the polyol component. In this case, the polyurethane has ester bonds. Ester bonds can be decomposed by attack with amine compounds. Polyurethanes having ester bonds are prone to degradation upon contact with amine compounds. On the other hand, polyurethane containing ester bonds is less susceptible to degradation of the ester bonds by amine compounds when it is present in coexistence with ZSM-5 type zeolite. Therefore, the elastic member in which the polyol component is polyester polyol is more suitable for enjoying the degradation-suppressing effect of containing ZSM-5 type zeolite. 【0041】 The above isocyanate component is not particularly limited and examples include aliphatic isocyanates, alicyclic isocyanates, aromatic isocyanates, etc. Among these, aromatic isocyanates are preferred because they provide good wear resistance to the elastic member. Examples of the above-mentioned aliphatic isocyanates include 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Other examples include modified isocyanurate, biuret, and adduct compounds of hexamethylene diisocyanate and isophorone diisocyanate. Examples of the above-mentioned alicyclic isocyanates include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, norbornane diisocyanate (NBDI), and other alicyclic diisocyanates. 【0042】 Examples of the above aromatic isocyanates include tolylene diisocyanate (TDI), phenylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, and mixtures of diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate (XDI), and the like. In this specification, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, and mixtures of diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate are collectively referred to as MDI. Examples of the above aromatic isocyanates include carbodiimide-modified MDI and urethane-modified MDI. The above isocyanate components may be used individually or in combination of two or more. 【0043】 TDI and MDI are preferred as the above isocyanate components, because they exhibit particularly good abrasion resistance among aromatic isocyanates. As the above-mentioned MDI, pure MDI (4,4'-diphenylmethane diisocyanate) and polymeric MDI (a mixture of 4,4'-diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate) are preferred. 【0044】 Examples of the above-mentioned crosslinking agents (including chain extenders) include 1,4-butanediol (1,4-BD), 1,4-bis(β-hydroxyethoxy)benzene (BHEB), ethylene glycol, propylene glycol, hexanediol, diethylene glycol, trimethylolpropane (TMP), glycerin, 4,4'-methylenebis(2-chloroaniline), hydrazine, ethylenediamine, diethylenetriamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodicyclohexylmethane, N,N-bis(2-hydroxypropyl)aniline, water, and the like. Among these, 1,4-butanediol, TMP, and BHEB are preferred because they easily produce appropriate rubber hardness and rigidity. Furthermore, thermosetting urethane compositions containing 1,4-butanediol, TMP, and BHEB have a relatively long pot life and can be molded even by hand casting. The above crosslinking agent may be used alone or in combination of two or more types. 【0045】 The ZSM-5 type zeolite described above plays a role in capturing amine compounds contained in cutting fluids. By capturing amine compounds, the ZSM-5 type zeolite can suppress contact between the amine compounds and polyurethane, thereby suppressing the attack of amine compounds on urethane bonds. 【0046】 As the above-mentioned ZSM-5 type zeolite, a ZSM-5 type zeolite with a small particle size is preferred. The average particle size of the above ZSM-5 type zeolite is preferably between 80 nm and 700 nm. This is because it allows for the capture performance of amine compounds with a small amount of material. It also does not impair the physical properties or moldability of the elastic material. In the above ZSM-5 type zeolite, a more preferable average particle size is 80 nm to 350 nm, an even more preferable average particle size is 85 nm to 240 nm, and a particularly preferable average particle size is 90 nm to 120 nm. 【0047】 The average particle size of the above ZSM-5 type zeolite is the D50 (median diameter) measured by laser diffraction using a laser diffraction particle size distribution analyzer (e.g., Shimadzu Corporation, SALD-7000) after dispersing the zeolite in water (concentration of 0.01% by mass or less). 【0048】 Examples of the above-mentioned ZSM-5 type zeolite include Ca ion type ZSM-5 zeolite, which uses Ca ions as countercations, and Na ion type ZSM-5 zeolite, which uses Na ions as countercations. Among these, Ca ion type ZSM-5 zeolite is preferred because it is less likely to generate air during the molding process and has good moldability. 【0049】 Commercially available products can also be used as the ZSM-5 type zeolite mentioned above. Examples of such commercially available products include nano-sized zeolite (product name, Zeol) manufactured by Nakamura Choko Co., Ltd. 【0050】 In the above-mentioned elastic member, the content of the ZSM-5 type zeolite relative to the total amount of the polyol component, the isocyanate component, and the crosslinking agent (amount of polyurethane) is preferably 0.4% by mass or more and 2.1% by mass or less. If the content of the above-mentioned ZSM-5 type zeolite is less than 0.4% by mass, degradation due to contact with amine compounds may not be sufficiently suppressed. On the other hand, if the content of the above-mentioned ZSM-5 type zeolite exceeds 2.1% by mass, it becomes difficult to uniformly disperse the ZSM-5 type zeolite, and moldability may be poor, such as the occurrence of large shrinkage marks in the molded product. A more preferable content of the ZSM-5 type zeolite relative to the total amount of the polyol component, the isocyanate component, and the crosslinking agent (amount of polyurethane) is 0.75% by mass or more and 1.15% by mass or less. 【0051】 The above-mentioned elastic member may contain inorganic particles. In this case, the inorganic particles may be included in the above-mentioned thermosetting urethane composition. Examples of the inorganic particles mentioned above include inorganic oxide particles consisting of inorganic oxides such as cerium oxide, zirconium oxide, zinc oxide, aluminum oxide, iron oxide, and silica; metal powders consisting of metals such as copper, nickel, iron, and aluminum; and inorganic balloons such as glass balloons and fly ash balloons. The inorganic particles described above may be of one type only, or two or more types may be used in combination. Elastic members containing these inorganic particles can have their sliding resistance reduced. Furthermore, the hardness of the elastic member can be adjusted by incorporating these inorganic particles. 【0052】 In embodiments of the present invention, inorganic balloons refer to particles made of inorganic materials that have a hollow structure. Inorganic oxide particles refer to particles made of metal oxides such as cerium oxide, metalloid oxides such as silicon oxide, or composites thereof. When the inorganic oxide particles have a hollow structure, they are distinguished from inorganic oxide particles as inorganic balloons. 【0053】 The inorganic particles may be unevenly distributed within the elastic member. Specifically, it is preferable that they are unevenly distributed so that they are densely packed on the back side of the elastic member. In this case, it is suitable for reducing the sliding resistance of the elastic member while maintaining the overall elastic performance of the elastic member. When reducing the sliding resistance of an elastic member, cerium oxide particles are preferred among the inorganic particles mentioned above because they are compatible with polyurethane, have excellent chemical stability, and are suitable for reducing sliding resistance. The amount of inorganic particles can be appropriately selected depending on the type of inorganic particles. For example, it is preferable that the amount of inorganic particles be 1 part by mass or more and 5 parts by mass or less per 100 parts by mass of the total amount of the polyol component, the isocyanate component, and the crosslinking agent. 【0054】 The above thermosetting urethane composition may also contain other reaction aids such as antioxidants, hydrolysis inhibitors, crosslinking accelerators and crosslinking retarders, colorants, light stabilizers, heat stabilizers, fungicides, flame retardants, fillers, carbon black, abrasives, etc. 【0055】 The isocyanate group concentration in the above thermosetting urethane composition is preferably 5.50% by mass or more and 10.0% by mass or less. If the isocyanate group concentration is less than 5.50% by mass, the wear resistance of the elastic member may be insufficient. On the other hand, if the isocyanate group concentration exceeds 10.0% by mass, the cured product may become too hard, resulting in increased sliding resistance of the elastic member. The above isocyanate group concentration (mass%) refers to the mass ratio of isocyanate groups contained in the total amount of isocyanate components, polyol components, and crosslinking agents in a thermosetting urethane composition in an uncrosslinked state. 【0056】 The above-mentioned elastic member can be manufactured by curing the above-mentioned thermosetting urethane composition and then cutting it to predetermined dimensions using an ultrasonic cutter or the like. The curing conditions for the above-mentioned thermosetting urethane composition are not particularly limited and can be set appropriately according to the composition of the thermosetting urethane composition, but typically conditions of heating at 100 to 160°C for 30 to 90 minutes can be adopted. Alternatively, after performing the curing treatment under the above conditions and demolding from the mold, post-curing may be performed, for example, at 100-160°C for 3-48 hours. 【0057】 Furthermore, the isocyanate and polyol components contained in the above thermosetting urethane composition may be reacted in advance to form a urethane prepolymer before curing the thermosetting urethane composition under predetermined conditions. That is, the above thermosetting urethane composition may contain a urethane prepolymer which is a reaction product of the isocyanate and polyol components, a crosslinking agent, and ZSM-5 type zeolite. 【0058】 The method for molding the above thermosetting urethane composition into a predetermined shape is not particularly limited and includes, for example, atmospheric pressure casting, reduced pressure casting, centrifugal molding, continuous rotational molding, extrusion molding, injection molding, reaction injection molding (RIM), spin coating, and the like. Among these, centrifugal molding and continuous rotational molding are preferred. 【0059】 The hardness (JIS-A hardness) of the above-mentioned elastic member is preferably between 55° and 90°. If the hardness of the elastic member described above is less than 55°, it may deform significantly when sliding on the sliding surface of a machine tool, making it impossible to reliably prevent the intrusion of chips and other debris. On the other hand, if the hardness of the elastic member exceeds 90°, it may be too hard and break during sliding. A more preferable hardness for the elastic member is between 60° and 75°. The above JIS-A hardness values ​​are measured using a spring-type A hardness tester in accordance with JIS K 7312:1996. 【0060】 The rebound elasticity of the above-mentioned elastic member is preferably 10% to 50%. By setting the rebound elasticity of the above-mentioned elastic member within the above-mentioned range, it becomes easier to follow the undulation of the sliding surface, making it suitable for ensuring good sealing performance. In addition, when the rebound elasticity of the above-mentioned elastic member is within the above-mentioned range, it becomes easier to suppress the generation of abnormal noise (chatter noise) during sliding. A more preferable rebound elasticity is 20% to 40%. The rebound elasticity values ​​mentioned above were measured in accordance with JIS K 7312:1996. 【0061】 Since elastic members with this configuration are less prone to deterioration even when exposed to cutting fluids contained in amine compounds, machine tool sealing members equipped with the above-mentioned elastic members can maintain excellent sealing performance over a long period of time. 【0062】 (Bending support member) The material of the above-mentioned bending assist member may be the same as that of the above-mentioned support member. The above-mentioned bending assist member may be surface-treated with a primer to improve its compatibility with the adhesive layer interposed between it and the back surface of the elastic member. Furthermore, the surface of the bending auxiliary member (particularly the area in contact with the elastic member via the adhesive layer) may be roughened to improve adhesion through an anchoring effect. 【0063】 (adhesive layer) The adhesive layer for fixing the elastic member and the support member, and the adhesive layer for fixing the elastic member and the bending assist member are not particularly limited and may be appropriately selected considering the material of each member. Examples of the adhesive layer include those formed from EVA-based, polyamide-based, or polyurethane-based hot-melt adhesives, or curing-type adhesives. Alternatively, the adhesive layer may also consist of double-sided tape. The adhesive layer that joins the elastic member and the support member, and the adhesive layer that joins the elastic member and the bending assist member, may be made of the same material or they may be made of different materials. The thickness of the adhesive layer is not particularly limited, but is preferably 50 μm or more and 500 μm or less. 【0064】 The machine tool sealing member 10 can be manufactured, for example, by the following method. (1) Using steel plates or the like as starting materials, cut them to a predetermined size, and then process them by bending and flexing as necessary to produce the support member 11. (2) In addition to the production of the support member described in (1) above, an elastic member 21 of a predetermined size made of a cured product of a thermosetting urethane composition is produced by the method described above. (3) Apply adhesive to the support member 11 and / or elastic member 21 using an applicator or the like, and bond the two together in the predetermined position, then apply pressure and / or cure as necessary. By going through these processes, the machine tool sealing member 10 can be manufactured. When manufacturing the machine tool sealing member 20, a bending assist member may be provided and attached to the predetermined position. 【0065】 The machine tool sealing member according to an embodiment of the present invention can be used as a sealing member (also called a wiper) to protect sliding parts and sliding mechanisms of various machine tools such as lathes and machining centers from chips, cutting fluids, etc. Specifically, it can be used as, for example, a slide seal, a telescopic seal, a cover seal, a lip seal, etc. 【0066】 In this case, the cutting fluid used is preferably one that contains an amine compound. This is because it is a cutting fluid that allows the effects of the machine tool sealing member according to the embodiment of the present invention to be easily exhibited. In this case, the amine compound contained may be a primary amine, a secondary amine, or a tertiary amine. The above amine compound is added to the cutting fluid, for example, as a preservative or antifungal additive. The above cutting fluid may be either a water-insoluble cutting fluid or a water-soluble cutting fluid. Furthermore, the above cutting fluid may be synthetic. 【0067】 [Example Test] The following describes tests that evaluated the effects of the urethane molded article according to the embodiment of the present invention. Here, a urethane sheet was prepared from the cured product of a thermosetting urethane composition. The obtained urethane sheet was then evaluated. 【0068】 (raw materials) <Urethane prepolymer> ·MDI-PEA prepolymer (manufactured by Sumitomo Chemical Covestro Japan, SBU-0680, NCO = 6.2 mass%) 【0069】 <Crosslinking agent> ·1,4-BD (1,4-butanediol, manufactured by Mitsubishi Chemical Corporation) ·TMP (trimethylolpropane, manufactured by Mitsubishi Gas Chemical Company) As the crosslinking agent, a mixture of 1,4-BD and TMP at a mass ratio of 1,4-BD:TMP = 97:3 was used. 【0070】 <ZSM-5 type zeolite> · Manufactured by Nakamura Carbide Co., Ltd., Nano-sized zeolite zeol (Na 100nm) · Manufactured by Nakamura Carbide Co., Ltd., Nano-sized zeolite zeol (Ca 500nm) · Manufactured by Nakamura Carbide Co., Ltd., Nano-sized zeolite zeol (Ca 100nm) 【0071】 <Others> · Abrasive: Cerico CH-601, manufactured by Taiyo Kogyo Co., Ltd. 【0072】 (Test Example 1) (1) Adjust the temperature of each of the crosslinking agent, ZSM-5 type zeolite (nano-sized zeolite zeol (Ca 100nm)), and abrasive to 70°C. (2) Weigh the crosslinking agent (1,4-BD and TMP) and ZSM-5 type zeolite into a 500 cc polyethylene bottle so as to achieve a predetermined mixing ratio. The mixing ratio (mass ratio) of the crosslinking agent and ZSM-5 type zeolite is shown in Table 1. (3) Stir the crosslinking agent and ZSM-5 type zeolite thoroughly with a homogenizer. Then, defoam. 【0073】 (4) Seal the polyethylene bottle and shake it by hand. Then, weigh the mixture of the crosslinking agent and ZSM-5 type zeolite and keep it at 70°C. (5) While stirring the urethane prepolymer with an agitator, pre-measured abrasive material was added to the urethane prepolymer and dispersed. Then, a mixture of a crosslinking agent and ZSM-5 type zeolite was added and stirred to prepare a thermosetting urethane composition. The isocyanate group concentration (mass%) of the obtained thermosetting urethane composition before crosslinking was 5.83% by mass. 【0074】 (6) Next, the obtained urethane composition was placed in a centrifugal molding machine and crosslinked under the conditions of a mold temperature of 150°C, a rotation speed of 900 rpm, and a crosslinking time of 60 minutes to form a cylindrical cured product with a thickness of 1.6 mm, and then demolded. After that, one part of the cylindrical cured product was cut and unfolded into a plate shape, and post-crosslinking was performed in a blow-air oven under the conditions of 110°C for 24 hours to produce a urethane sheet A made of cured thermosetting urethane composition. 【0075】 (Test Example 2) Urethane sheet B was prepared in the same manner as in Test Example 1, except that the type of ZSM-5 zeolite (see Table 1) was changed. 【0076】 (Test Example 3) Urethane sheet C was prepared in the same manner as in Test Example 2, except that the mixing ratio of ZSM-5 type zeolite (see Table 1) was changed. 【0077】 (Test Example 4) Urethane sheet D was prepared in the same manner as in Test Example 1, except that the type of ZSM-5 zeolite (see Table 1) was changed and no abrasive was added. 【0078】 (Test Example 5) Urethane sheet E was prepared in the same manner as in Test Example 1, except that ZSM-5 type zeolite was not incorporated. 【0079】 [evaluation] Here, we first (1) evaluated the appearance of the urethane sheet, then cut out test pieces from the urethane sheet, and (2) evaluated their mechanical strength and (3) evaluated their durability against cutting fluids. In the evaluation described in (3) above, a water-soluble cutting fluid containing a total of approximately 20% by mass of primary and secondary amine compounds was used as the cutting fluid. 【0080】 (1) Appearance evaluation: The appearance of the fabricated urethane sheets A to E was visually inspected to evaluate the presence or absence of foaming (air) and shrinkage. The results are shown in Table 1. 【0081】 (2) Evaluation of mechanical strength Test pieces in the shape of dumbbells (Type 3, compliant with JIS K6251:2023) were cut from each of the urethane sheets A through E. Using this test piece, the elongation at break (EB) was measured according to the method compliant with JIS K7312:1996. The tensile speed during measurement was 500 mm / min. The results are shown in Table 1. 【0082】 (3) Durability evaluation against cutting fluids <Durability Rating A> Test pieces in the shape of dumbbells (Type 3, compliant with JIS K6251:2017) were cut from each of the urethane sheets A through E. The obtained test pieces were immersed in cutting fluid (liquid temperature: 50°C), and after 150 hours from the start of immersion, they were removed from the cutting fluid and the elongation at break (EB) was measured in the same manner as in (2) above. Subsequently, the ratio of the change in elongation at break (EB) due to immersion to the elongation at break (EB) before immersion (EB change rate) was calculated. The calculation results are shown in Figure 6. In this evaluation, a smaller absolute value of the percentage change indicates better durability against cutting fluids. 【0083】 <Durability Rating B> Each of the dumbbell-shaped test pieces, cut from urethane sheets A through E, was immersed in cutting fluid heated to 50°C. For each test piece, after 120 hours and 150 hours from the start of immersion, the test piece was removed from the cutting fluid, and one chuck portion (the wider part) was bent 180°. The presence or absence of cracks was then visually inspected in this state. For test pieces cut from urethane sheet D, only a visual inspection was performed after 150 hours. The results are shown in Figures 7A, 7B, 8A, 8B, 9A, 9B, 10, 11A, and 11B. 【0084】 Figure 7A is a photograph of a test piece cut from urethane sheet A in Test Example 1 after being immersed in cutting fluid for 120 hours. Figure 7B is a photograph of a test piece cut from urethane sheet A in Test Example 1 after being immersed in cutting fluid for 150 hours. 【0085】 Figure 8A is a photograph of a test piece cut from urethane sheet B in Test Example 2 after being immersed in cutting fluid for 120 hours. Figure 8B is a photograph of a test piece cut from urethane sheet B in Test Example 2 after being immersed in cutting fluid for 150 hours. 【0086】 Figure 9A is a photograph of a test piece cut from urethane sheet C in Test Example 3 after being immersed in cutting fluid for 120 hours. Figure 9B is a photograph of a test piece cut from urethane sheet C in Test Example 3 after being immersed in cutting fluid for 150 hours. 【0087】 Figure 10 shows a photograph of a test piece cut from urethane sheet D in Test Example 4 after being immersed in cutting fluid for 150 hours. Note that the black circles on the surface of the test piece shown in Figure 10 were drawn with an oil-based marker. 【0088】 Figure 11A is a photograph of a test piece cut from urethane sheet E in Test Example 5 after being immersed in cutting fluid for 120 hours. Figure 11B is a photograph of a test piece cut from urethane sheet E in Test Example 5 after being immersed in cutting fluid for 150 hours. 【0089】 [Table 1] 【0090】 Based on the results of (1) to (3) above, the urethane molded article having the composition of Test Example 1 is considered to be extremely suitable as an elastic component for a machine tool sealing member. Although some shrinkage was observed in the urethane molded article with the composition of Test Example 3, good performance can be expected when used as an elastic component in a machine tool sealing member. Furthermore, a urethane molded body having the composition of Test Example 2 can also be used as an elastic component in a machine tool sealing member. 【0091】 The urethane molded article with the composition of Test Example 4 is prone to generating air during molding, making it difficult to ensure its performance as an elastic component for machine tool sealing members. The urethane molded article with the composition of Test Example 5 does not contain ZCM-5, and therefore is considered to have poor durability against cutting fluids containing amine compounds. 【0092】 (Other urethane molded products) The urethane molded articles described so far are cured products of a thermosetting urethane composition containing ZSM-5 type zeolite. In other words, the polyurethane constituting the urethane molded article is polyurethane formed through a thermosetting treatment. On the other hand, the polyurethane constituting the urethane molded article according to the embodiment of the present invention may be thermoplastic polyurethane. In this case, the urethane molded article contains thermoplastic polyurethane and ZSM-5 type zeolite. This urethane molded article is also less susceptible to degradation by amine compounds. The thermoplastic polyurethane mentioned above may be polycarbonate-based polyurethane or polyether-based polyurethane, but polyester-based polyurethane is preferred. [Explanation of Symbols] 【0093】 10, 20, 30 Sealing components for machine tools 11, 51 Support members 11a Support surface 12, 52 Support part 13 Protection part 21 Elastic members 21a Front side 22 Fixed part 23 Lip section 24 Edge section 31, 38 Adhesive layer 32 bolt holes 35 Mounting part 36 Sliding surface 41 Curving assist member 42 Main body 43 Auxiliary part

Claims

[Claim 1] A urethane molded article containing polyurethane and ZSM-5 type zeolite. [Claim 2] The urethane molded article according to claim 1, wherein the average particle size of the ZSM-5 type zeolite is 80 nm or more and 700 nm or less. [Claim 3] The urethane molded article according to claim 1 or 2, wherein the ZSM-5 type zeolite is of the Ca ion type. [Claim 4] The urethane molded article according to claim 1 or 2, wherein the content of the ZSM-5 type zeolite is 0.4% by mass or more and 2.1% by mass or less relative to the polyurethane. [Claim 5] A sealing member for a machine tool having an elastic member and a support member, The elastic member is made of a cured product of a thermosetting urethane composition. The thermosetting urethane composition contains a polyol component, an isocyanate component, a crosslinking agent, and a ZSM-5 type zeolite. Sealing components for machine tools. [Claim 6] The sealing member for a machine tool according to claim 5, wherein the average particle size of the ZSM-5 type zeolite is 80 nm or more and 700 nm or less. [Claim 7] The machine tool sealing member according to claim 5 or 6, wherein the ZSM-5 type zeolite is of the Ca ion type. [Claim 8] The content of the ZSM-5 type zeolite is 0.4% by mass or more and 2.1% by mass or less with respect to the total amount of the polyol component, the isocyanate component, and the crosslinking agent, as described in claim 5 or 6 for a machine tool sealing member. [Claim 9] The aforementioned ZSM-5 type zeolite is of the Ca ion type, The average particle size of the ZSM-5 type zeolite is between 90 nm and 120 nm. The content of the ZSM-5 type zeolite is 0.8% by mass or more and 1.2% by mass or less, relative to the total amount of the polyol component, the isocyanate component, and the crosslinking agent. The machine tool sealing member according to claim 5.

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