TWI719071B - Sealing member for machine tool - Google Patents

Abstract

The present invention provides an elastomer member suitable for use in machine tools, and a sealing member for machine tools using the elastomer member. The elastomer member is characterized in that it includes a cured product of a thermosetting polyurethane composition, the thermosetting polyurethane composition containing a polyol component, an isocyanate component, and a crosslinking agent, And the polyol component is polyethylene adipate polyol (PEA), the JIS-A hardness is 67° or more, and it is used for working machinery.

Description

Sealing member for machine tool

The present invention relates to an elastomer member and a sealing member for machine tools.

Machine tools such as lathes or machining centers are the most basic mechanical devices commonly used in the manufacturing industry. In these working machines, in order to protect the drive mechanism from cutting chips or coolant (cutting oil), for example, lip seals, slide seals, telescopic seals, and cover seals are used. (cover seal) and other sealing members.

As a sealing member for machine tools, a sealing member including a support member and an elastic member integrated with the support member is known.

It has been proposed that the above-mentioned sealing members use: chloroprene rubber (CR), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (H-NBR), styrene Rubber materials such as styrene butadiene rubber (SBR), ethylene-propylene diene monomer (EPDM), and elastic materials such as polyurethane are used as materials for elastic members (such as Refer to Patent Document 1).

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2014-8575

As described above, the sealing member for machine tools is a member that protects the drive mechanism from the coolant or the like. Therefore, when the sealing member for machine tools is used, the elastic member is exposed to the coolant.

The elastic member exposed to the coolant is slowly swelled by the coolant. As a result, the sealing member for machine tools no longer performs its function and must be replaced. In addition, when the elastic member containing the additive is exposed to the coolant, the additive may be eluted. As a result, the physical properties of the elastic member may change, and the function of the sealing member for machine tools may no longer be performed.

The coolant is roughly classified into water-insoluble cutting oil and water-soluble cutting oil, and the characteristics of the two are different. In contrast, the existing elastic members of seal members for machine tools are only: (a) those that are difficult to swell or dissolve in water-insoluble cutting oil, but are easy to swell or dissolve in water-soluble cutting oil; or (b) are soluble in water It is difficult to swell or dissolve in the cutting oil, but it is easy to swell or dissolve in the insoluble cutting oil. That is, there is no known elastic member that is difficult to swell and dissolve in either of the water-insoluble cutting oil and the water-soluble cutting oil.

The inventors of the present invention conducted intensive research in order to solve the above-mentioned problems, and found that a kind of coolant is difficult to swell or the additives are difficult to dissolve in any of the insoluble cutting oil and the water-soluble cutting oil, and it is suitable for use in the coolant. Flexibility of working machinery Body member, thus completing the present invention.

The elastomer member of the present invention is characterized in that it contains a cured product of a thermosetting polyurethane composition, the thermosetting polyurethane composition containing a polyol component, an isocyanate component, and a crosslinking agent And the polyol component is polyethylene adipate ester polyol (PEA), the Japanese Industrial Standards (JIS)-A hardness is 67° or more, and the elastomer member is used for Working machinery.

Since the elastomer member contains a hardened product of a thermosetting urethane composition having a JIS-A hardness of 67° or more, it is difficult for any coolants, such as water-insoluble cutting oils and water-soluble cutting oils. Swelling and difficult to dissolve.

Therefore, it can be suitably used for machine tools that use coolant.

The sealing member for machine tools of the present invention is a sealing member for machine tools including a support member and an elastic member integrated with the support member. The sealing member for machine tools is characterized in that the elastic member contains the elastic member of the present invention. Elastomer member.

According to the sealing member for machine tools, the elastic member includes the elastomer member of the present invention that is hard to swell and hard to dissolve due to a coolant. Therefore, the sealing member for machine tools is hard to deteriorate even if exposed to a coolant, and can maintain excellent sealing performance over a long period of time.

The elastomer member of the present invention has excellent durability against cutting oil (coolant), regardless of whether it is water-insoluble cutting oil or water-soluble cutting oil.

Since the sealing member for machine tools of the present invention includes the elastomer member of the present invention, it can maintain excellent sealing performance over a long period of time.

10.20: Sealing components for machine tools

11, 21: Supporting components

12, 22, 32: elastic member

12a, 22a: edge

13: Adhesive layer

15: cover member

15a: outer surface of cover member 15

22A: Body part

22B: Lips

100: Telescopic cover

Fig. 1(a) is a plan view showing an example of a sealing member for machine tools according to an embodiment of the present invention, and Fig. 1(b) is a side view of Fig. 1(a).

Fig. 2(a) is a back view showing another example of the sealing member for machine tools according to the embodiment of the present invention, and Fig. 2(b) is a side view of Fig. 2(a).

Fig. 3 is a cross-sectional view schematically showing a part of a telescopic cover to which a sealing member for machine tools according to an embodiment of the present invention is attached.

Fig. 4(a) is a graph showing the immersion time and weight increase rate when the sheet produced in the example is immersed in coolant A (50°C), and Fig. 4(b) is a graph showing when the sheet produced in the comparative example is immersed A graph of the immersion time and weight increase rate when the sheet is immersed in coolant A (50°C).

Fig. 5(a) is a graph showing the immersion time and weight increase rate when the sheet produced in the example is immersed in coolant B (50°C), and Fig. 5(b) is a graph showing when the sheet produced in the comparative example is immersed A graph of the immersion time and weight increase rate when the sheet is immersed in coolant B (50°C).

Fig. 6(a) is a graph showing the immersion time and weight increase rate when the sheet produced in the example is immersed in coolant C (50°C), and Fig. 6(b) is a graph showing when the sheet produced in the comparative example is immersed A graph of the immersion time and weight increase rate when the sheet is immersed in coolant C (50°C).

Fig. 7 is a photograph and a schematic diagram of the state of the edge portion when the sealing member for machine tools using the urethane sheet of Example 2 as the elastic member is used.

8 is a photograph and a schematic diagram of the state of the edge portion when the sealing member for machine tools using the rubber sheet of Comparative Example 1 as the elastic member is used.

Hereinafter, an embodiment of the present invention will be described.

<Elastomer member>

The elastomer member of the embodiment of the present invention includes a cured product of a thermosetting urethane composition.

The thermosetting urethane composition contains a polyol component, an isocyanate component, and a crosslinking agent, and the polyol component is polyethylene adipate polyol (PEA).

Since the elastomer member is a cured product of a thermosetting urethane composition in which the polyol component is PEA, it is difficult to cause swelling or elution caused by a coolant. Therefore, when used in a working machine that uses a coolant, even if it is exposed to the coolant, it can meet its required characteristics over a long period of time.

The PEA preferably has a number average molecular weight of 1,000 to 3,000. The elastomer member using PEA having a number average molecular weight within the above-mentioned range can more reliably prevent the intrusion of cutting powder, coolant, and the like when it comes into contact with the target material.

The number average molecular weight is a polystyrene conversion value measured by gel permeation chromatography (GPC).

The thermosetting urethane composition contains PEA (polyol In addition to component), it also contains an isocyanate component and a crosslinking agent.

The said isocyanate component is not specifically limited, For example, aliphatic isocyanate, alicyclic isocyanate, aromatic isocyanate, etc. are mentioned. Among these isocyanate components, an aromatic isocyanate is preferable in terms of good abrasion resistance.

Examples of the aliphatic isocyanate include: 1,6-hexamethylene diisocyanate (1,6-hexamethylene diisocyanate, HDI), 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Isocyanate, etc. In addition, an isocyanurate body, a biuret body, an adduct body, etc. of hexamethylene diisocyanate or isophorone diisocyanate may also be mentioned.

Examples of the alicyclic isocyanate include: isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, norbornane diisocyanate (norbornane diisocyanate, NBDI) and other alicyclic diisocyanates.

Examples of the aromatic isocyanate include: tolylene diisocyanate (TDI); phenylene diisocyanate; 4,4'-diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, diphenyl A mixture of methylmethane diisocyanate and polymethylene polyphenylene polyisocyanate (hereinafter, these are also collectively referred to as MDI), 1,5-naphthalene diisocyanate (1,5-naphthalene diisocyanate, NDI); xylylene Diisocyanate (xylylene diisocyanate, XDI); carbodiimide modified MDI; urethane modified MDI, etc.

These isocyanate components may be used alone, or two or more of them may be used in combination.

The isocyanate component is preferably MDI or NDI. The reason is, Among the aromatic isocyanates, it exhibits particularly good abrasion resistance.

Examples of the crosslinking agent include: 1,4-butanediol (1,4-butanediol, 1,4-BD), 1,4-bis(β-hydroxyethoxy)benzene (1,4-bis (β-hydroxy ethoxy)benzene, BHEB), ethylene glycol, propylene glycol, hexanediol, diethylene glycol, trimethylol propane (TMP), glycerol, 4,4'-methylene bis( 2-chloroaniline), hydrazine, ethylenediamine, diethylenetriamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodicyclohexylmethane, N,N-bis( 2-hydroxypropyl)aniline, water, etc.

Among these crosslinking agents, 1,4-butanediol, TMP, and BHEB are preferred in terms of easily expressing appropriate rubber hardness and rubber rigidity. In addition, the thermosetting urethane composition containing 1,4-butanediol, TMP, or BHEB has a relatively long pot life, and can also be formed by manual casting.

The crosslinking agent may be used alone, or two or more of them may be used in combination.

The thermosetting urethane composition may further contain, if necessary, reaction aids such as chain extenders, crosslinking accelerators or crosslinking delay agents, hydrolysis inhibitors, reinforcement materials such as inorganic fibers or inorganic fillers, Various additives such as colorants, light stabilizers, heat stabilizers, antioxidants, antifungal agents, flame retardants, fillers (extenders), etc.

The isocyanate group concentration in the thermosetting urethane composition is preferably 5.50% by weight to 10.0% by weight.

If the isocyanate group concentration is less than 5.50% by weight, when the elastomer member is used as an elastic member of a sealing member for machine tools described later, the abrasion resistance of the elastic member may become insufficient. On the other hand, if the isocyanate If the base concentration exceeds 10.0% by weight, the hardened product may become too hard, and the sliding resistance may increase.

The aforementioned isocyanate group concentration (% by weight) refers to the weight ratio of the isocyanate group contained in the total amount of the isocyanate component, the polyol component, and the crosslinking agent.

The JIS-A hardness of the cured product of the thermosetting urethane composition (a value measured with a spring type type A hardness tester in accordance with JIS K 7312) is 67° or more.

When the JIS-A hardness of the hardened product is less than 67°, the hardened product has few crosslinking points, and swelling due to exposure to the coolant cannot be sufficiently avoided.

On the other hand, the upper limit of the JIS-A hardness of the hardened product is not particularly limited, as long as it is appropriately selected in consideration of the use location of the elastomer member.

When the elastic member is used as an elastic member of a sealing member for machine tools described later, the JIS-A hardness of the hardened product is preferably 67° to 90°. If the JIS-A hardness of the hardened product is less than 67°, as described above, there may be cases where it does not exhibit resistance to coolant. On the other hand, if the JIS-A hardness of the cured product exceeds 90°, the stress (crimping force) of the seal portion increases excessively, and as a result, the sliding resistance may increase excessively.

The JIS-A hardness is more preferably 70°~85°.

The elastomer member is obtained by curing the thermosetting urethane composition under a predetermined condition.

The curing conditions of the thermosetting urethane composition are not particularly limited, as long as they are appropriately set according to the composition of the thermosetting urethane composition. can. The curing conditions can generally be heated at 100°C to 160°C for 30 minutes to 90 minutes.

In addition, after the hardening treatment is carried out under the above-mentioned conditions and after demolding from the mold etc., post hardening may be carried out under the conditions of 100°C to 160°C for 3 hours to 48 hours.

The isocyanate component and polyol component contained in the thermosetting urethane composition may be formed by reacting in advance before curing the thermosetting urethane composition under predetermined conditions Prepolymer.

The molding method of the thermosetting urethane composition for obtaining the elastomer member is not particularly limited. Examples of the molding method include atmospheric casting molding, reduced pressure casting molding, centrifugal molding, continuous rotation molding, extrusion molding, injection molding, reaction injection molding (RIM), spin coating, and the like.

Among these methods, centrifugal forming and continuous rotation forming are preferred.

The elastomer member as described above can be suitably used for a working machine using a coolant.

<Sealing components for machine tools>

The elastic member of the embodiment of the present invention can be suitably used as the elastic member in a sealing member for machine tools including a support member and an elastic member integrated with the support member.

Fig. 1(a) is a plan view showing an example of a sealing member for machine tools according to an embodiment of the present invention, and Fig. 1(b) is a side view of Fig. 1(a).

As shown in FIGS. 1( a) and (b ), the sealing member 10 for machine tools includes a supporting member 11 and an elastic member 12.

The supporting member 11 includes a processed metal plate that is bent along the longitudinal direction of a substantially rectangular metal plate.

The elastic member 12 is a plate-shaped member 12 fixed along the longitudinal direction of the support member 11 via an adhesive layer 13. The elastic member 12 includes the elastic member.

The edge portion 12a of the elastic member 12 of the sealing member 10 for machine tools is slidably contacted with the target material, whereby a predetermined part of the machine tool can be reliably sealed.

Generally, in terms of durability or strength, the support member 11 includes a metal material such as steel or aluminum. The supporting member 11 can also be made of ceramic or rigid plastic.

The support member 11 can also be used: steel plate with untreated surface, steel plate with surface treatment such as zinc phosphate treatment, chromate treatment, rust-proof resin treatment, etc., processed by elastic metal plate such as phosphor bronze or spring steel.

In order to improve the compatibility of the support member 11 with the adhesive layer 13, the surface treatment may be performed in advance with a urethane-based primer, a silane-based primer, or the like.

In addition, the surface of the support member 11 (especially the area in contact with the elastic member 12 via the adhesive layer 13) may be roughened. Thereby, the anchoring effect can be used to improve the adhesion between the support member 11 and the adhesive layer 13.

The elastic member 12 includes the elastic member formed in a plate shape. The elastic member 12 is fixed to the supporting member 11 via the adhesive layer 13. The elastomer member is as described above.

The JIS-A hardness of the elastic member 12 is as described above, and is preferably 67° to 90°.

The impact resilience of the elastic member 12 is preferably 10%~50%.

The elastic member 12 is, for example, a member that slides on the contact surface on the machine tool side. In this case, the elastic member 12 is required to have adaptability to follow the unevenness of the surface of the contact surface and the performance of not generating in-position sound (beat noise) when sliding it. These two properties are properties in a trade-off relationship, but the two properties can coexist by setting the impact resilience rate of the elastic member 12 to the above range. The impact rebound rate is more preferably 20%-40%.

The impact rebound rate is a value measured in accordance with JIS K 7312.

The adhesive layer 13 has a function of joining the support member 11 and the elastic member 12. The adhesive layer 13 is not particularly limited as long as it can join the elastic member 12 and the support member 11 with a sufficient adhesive force.

The adhesive layer 13 may be, for example, made of ethylene vinyl acetate (EVA), polyamide, or polyurethane hot melt adhesives or hardening adhesives, etc. Those formed by using double-sided tape, etc.

In terms of excellent bonding strength between the support member 11 and the elastic member 12, the adhesive layer 13 is preferably formed of a urethane-based hot-melt adhesive. The adhesive layer 13 is particularly preferably formed of a moisture-curable urethane-based hot-melt adhesive.

The adhesive layer 13 formed of the moisture-curable urethane-based hot-melt adhesive will not melt or soften even when the sealing member 10 for machine tools reaches a high temperature during use. Can maintain stable adhesion.

The so-called moisture-curing urethane-based hot-melt adhesive is After coating and bonding in a molten state, it reacts with moisture attached to the surface of the elastic member and/or support member or moisture in the environment to gradually undergo crosslinking reaction. It includes urethane Prepolymer.

As a specific example, for example, a urethane prepolymer containing 30% to 50% by weight (for example, a polycarbonate-based urethane prepolymer), and a thermoplastic content of 0% to 70% by weight are included. Moisture-curing urethane-based hot-melt adhesives such as resins and 0% to 50% by weight of adhesion imparting agents.

The urethane prepolymer has two or more isocyanate groups in the molecule and is cured by reacting with moisture in the environment.

As said thermoplastic resin, saturated polyester etc. are mentioned, for example. The thermoplastic resin in the moisture-curing urethane-based hot melt adhesive has the function of increasing the adhesive force by imparting crystallinity, and can be used at a temperature of about 120°C to 140°C The role of the coated plasticizer. The thermoplastic resin can impart excellent low-temperature workability to the moisture-curing urethane-based hot-melt adhesive.

Commercial products can also be used for the moisture-curing urethane-based hot-melt adhesive. The commercially available products include, for example, TiForce H-810, TiForce H-850, TiForce PUR-1S, TiForce H-910, and TiForce H-910. TiForce FH-445, TiForce FH-315SB, TiForce FH-430, TiForce FH-00SB (all manufactured by DIC), RHC-101, 5921 (manufactured by No-tape INDUSTRIAL CO., LTD.), Hibon 4836M, Hibon 4836S, Hibon 4836W (Hitachi Chemical Polymers Co., Ltd.) Manufacturing) and so on.

Among these commercially available products, TiForce H-810 and TiForce H-850 are preferred.

The thickness of the adhesive layer 13 is not particularly limited, but is preferably 50 μm to 500 μm.

In the case where the adhesive layer 13 includes a hot-melt adhesive, the thickness thereof is preferably 50 μm to 200 μm. If it is less than 50 μm, it may not be possible to ensure sufficient adhesive strength. On the other hand, if it exceeds 200 μm, the melting of the hot melt adhesive may require excessive temperature and time.

The sealing member 10 for machine tools can be manufactured by the following method, for example.

(1) After cutting a steel plate or the like as a starting material to a predetermined size, bending processing or the like is performed as necessary to produce the support member 11.

(2) Separately from the production of the support member 11 in (1), a sheet-shaped elastomer member containing a cured product of the thermosetting urethane composition is separately produced. Then, using an ultrasonic cutter or the like, the obtained elastic member is cut into a predetermined size, and the elastic member 12 is produced.

In addition, the forming method of the elastomer member is as described above.

(3) After applying an adhesive to at least one of the supporting member 11 and the elastic member 12 using an applicator or the like, the two are attached at a predetermined position. Then, pressurization and/or maturation are performed as needed.

By passing through the steps, the sealing member 10 for machine tools can be manufactured.

In the sealing member 10 for machine tools shown in Figs. 1(a) and (b), the shape of the elastic member 12 is a plate shape with a rectangular cross section, but it is in the embodiment of the present invention. In the state of the sealing member for machine tools, the shape of the elastic member is not limited to the shape. The shape of the elastic member may be a shape in which the edge portion is C-chamfered or R-chamfered, for example. Furthermore, the said elastic member may have the shape which the cross-sectional shape (shape of the surface perpendicular|vertical to a longitudinal direction) becomes thin continuously or intermittently toward an edge part.

The sealing member for machine tools of the embodiment of the present invention may be a sealing member for machine tools as shown in Figs. 2(a) and (b).

Fig. 2(a) is a back view showing another example of the sealing member for machine tools according to the embodiment of the present invention, and Fig. 2(b) is a side view of Fig. 2(a).

As shown in FIGS. 2( a) and (b ), the sealing member 20 for machine tools includes a support member 21 including a plate-shaped metal plate, and an elastic member 22 integrally formed with the support member 21.

The elastic member 22 includes a main body 22A that is joined to the support member, and a lip 22B that extends from the main body 22A and has an edge portion 22a that contacts the target material.

The elastic member 22 includes the elastic member.

The edge part 22a of the elastic member 22 of the sealing member 20 for machine tools is slidably contacted with the target material, and the predetermined part of a machine tool can be sealed reliably.

As described above, in the sealing member for machine tools according to the embodiment of the present invention, the supporting member and the elastic member may be integrated without passing through the adhesive layer.

In the sealing member 20 for machine tools, the material of the supporting member 21 is the same as that of the supporting member 11 in the sealing member 10 for machine tools, and metal, ceramic, rigid plastic, etc. can be used.

In the sealing member 20 for a machine tool, the elastic member 22 is the above-mentioned elastomer member, and its preferable physical properties are the same as those of the elastic member 12 in the sealing member 10 for a machine tool.

In addition, in the sealing member 20 for machine tools, a primer layer may be interposed between the support member 21 and the elastic member 22. Thereby, the adhesion between the support member 21 and the elastic member 22 can be further improved.

The sealing member 20 for machine tools can be manufactured by arranging the supporting member 21 at a predetermined position in the mold, casting an uncured thermosetting urethane composition, and curing it under predetermined curing conditions.

Here, the curing conditions of the thermosetting urethane composition are as described above.

The shape of the sealing member for machine tools according to the embodiment of the present invention is not limited to the shape shown in Figs. 1(a) and (b) and Figs. 2(a) and (b). The sealing member for machine tools may have the same shape as that of conventional sealing members for machine tools, such as a lip seal, a sliding seal, a telescopic seal, and a cover seal.

The sealing member for machine tools of the embodiment of the present invention can be used in various machine tools such as lathes and cutting machines as a way to protect sliding parts or sliding mechanisms of machine tools from cutting powder or coolant (cutting oil). A sealing member (wiper member) is used. Specifically, it can be used as a sliding seal, a telescopic seal, a cover seal, a lip seal, etc., for example.

Hereinafter, a case where the sealing member for machine tools according to the embodiment of the present invention is used as a telescopic seal will be described as an example of its use. Fig. 3 is a schematic view of a telescopic cover mounted with a sealing member 10 for machine tools according to an embodiment of the present invention (telescopic cover) 100 is a cross-sectional view of a part.

As shown in FIG. 3, the sealing member 10 for machine tools is fixed by screwing the support member 11 (not shown) to the lower surface of the outer front-end part of each cover member 15 which comprises the retractable cover 100. As shown in FIG. At this time, the sealing member 10 for machine tools is installed at a position where the outer surface 15a of the cover member 15 located on the lower side and the end of the elastic member 12 are in sliding contact with each other reliably.

In addition, in the supporting member 11, through holes (not shown) for bolts are formed in advance.

As described above, the telescopic cover 100 with the machine tool sealing member 10 attached to the outer front end of each cover member 15 can prevent the cutting powder and the like existing on the outer side of the telescopic cover 100 from entering the cover when the telescopic cover 100 is expanded and contracted.

Of course, the use of the sealing member for machine tools of the embodiment of the present invention is not limited to the expansion seal.

The elastic member of the embodiment of the present invention can also be used in addition to the elastic member of the sealing member for machine tools. Specifically, it can also be used for, for example, a drive belt provided in a machine tool.

In the working machine, various components are constructed by using a driving belt to drive. Among the transmission belts used in the working machine, there is also a transmission belt that is arranged at a position exposed to the coolant. Such transmission belts may deteriorate (swell or dissolve additives) due to exposure to coolant, or may break depending on the situation. In contrast, if it is a transmission belt using the elastic member, the deterioration caused by the coolant can be suppressed.

[Example]

Hereinafter, the embodiments of the present invention will be further described in detail through examples, but the present invention is not limited to the following examples.

(Example 1)

To 100.00 parts by weight of MDI-PEA prepolymer (manufactured by Sanyo Chemical Co., Ltd., trade name "Sanprene P-6814") heated to 110°C, 5.60 parts by weight of 1,4-BD ( Mitsubishi Chemical Corporation) and 0.76 parts by weight of TMP (Mitsubishi Gas Corporation) were stirred and mixed to prepare a urethane composition. Put the immediately obtained urethane composition into a centrifugal molding machine, cross-link it under the conditions of a mold temperature of 150°C and a cross-linking time of 60 minutes, and mold a cylindrical hardened product with a thickness of 1.5 mm After that, demoulding is carried out. Then, one part of the cylindrical cured product was cut and expanded into a plate shape, and post-crosslinking was carried out in a blower oven at 110°C for 24 hours to obtain a full width made of polyurethane sheet.

Then, the whole sheet was cut into a length of 12 mm × a width of 49 mm to form a long urethane sheet. The JIS-A hardness of the urethane sheet was 70°.

In addition, the JIS-A hardness of the urethane sheet is measured by stacking 10 urethane sheets having a thickness of 1.5 mm in accordance with JIS K 7312.

(Example 2)

Except that the blending amount of 1,4-BD was changed to 6.36 parts by weight and the blending amount of TMP was changed to 0.20 parts by weight, a long urethane sheet was obtained in the same manner as in Example 1. The JIS-A hardness of the urethane sheet was 80°.

(Example 3)

To 100.00 parts by weight of MDI-PEA prepolymer (manufactured by Sanyo Chemical Co., Ltd., trade name "Sanprene P-6814") heated to 110°C, 10.50 parts by weight of BHEB (Mitsubishi Fine Chemicals Co., Ltd.) (Manufactured), and 1.59 parts by weight of 1,4-BD (manufactured by Mitsubishi Chemical Corporation), stirred and mixed to prepare a urethane composition. Put the immediately obtained urethane composition into a centrifugal molding machine, cross-link it under the conditions of a mold temperature of 150°C and a cross-linking time of 60 minutes, and mold a cylindrical hardened product with a thickness of 1.5 mm After that, demoulding is carried out. Then, one part of the cylindrical cured product was cut and expanded into a plate shape, and post-crosslinking was carried out in a blower oven at 110°C for 24 hours to obtain a full width made of polyurethane sheet.

Then, the whole sheet was cut into a length of 12 mm × a width of 49 mm to form a long urethane sheet. The JIS-A hardness of the urethane sheet is 90°.

(Example 4)

100.00 parts by weight of PEA (manufactured by Sumitomo Bayer Polyurethane Company, trade name "Vulkollan 2000MM") and 19.00 parts by weight of NDI (manufactured by Sumitomo Bayer Polyurethane Company, trade name "Desmodur 15" ), the reaction was carried out for 15 minutes while stirring in a vacuum reaction tank at 125°C to obtain a prepolymer. Then, 2.50 parts by weight of 1,4-BD (manufactured by Mitsubishi Chemical Corporation) was added to the obtained prepolymer, stirred and mixed, and then poured into a centrifugal molding machine. The mold temperature was set to 130°C and the crosslinking time was set to 60. It is cross-linked in minutes, and after molding a cylindrical hardened product with a thickness of 1.5 mm, it is demolded. Then, one part of the cylindrical cured product was cut and expanded into a plate shape, and post-crosslinking was carried out in a blower oven at 110°C for 24 hours to obtain a full width made of polyurethane sheet.

Then, the whole sheet was cut into a length of 12 mm × a width of 49 mm to form a long urethane sheet. The JIS-A hardness of the urethane sheet was 80°.

(Example 5)

Except that the blending amount of NDI was changed to 25.00 parts by weight and the blending amount of 1,4-BD was changed to 5.00 parts by weight, a long urethane sheet was obtained in the same manner as in Example 4. The JIS-A hardness of the urethane sheet is 90°.

(Example 6)

Except that the blending amount of NDI was changed to 40.00 parts by weight and the blending amount of 1,4-BD was changed to 11.00 parts by weight, a long urethane sheet was obtained in the same manner as in Example 4. The JIS-A hardness of the urethane sheet was 96°.

(Example 7)

Except that the compounding amount of 1,4-BD was changed to 4.58 parts by weight and the compounding amount of TMP was changed to 1.79 parts by weight, a long urethane sheet was obtained in the same manner as in Example 1. The JIS-A hardness of the urethane sheet was 67°.

Regarding the urethane tablets produced in Example 1 to Example 7, the formulation and the JIS-A hardness are shown in Table 1.

(Comparative example 1)

100.00 parts by weight of NBR (manufactured by ZEON, trade name "Nipol 1031") and 5.00 parts by weight of bis(2-ethylhexyl) phthalate (manufactured by Mitsubishi Chemical Corporation) ), 84.00 parts by weight of carbon black (manufactured by Tokai Carbon, trade name "ISAF"), 5.00 parts by weight of zinc oxide (manufactured by Nippon Chemical Industry Co., Ltd., trade name "zinc oxide"), 5.00 parts by weight Of zinc oxide (manufactured by Inoue Lime Industry Co., Ltd., trade name "META ZL-50"), and 0.40 parts by weight of sulfur (manufactured by Hosui Chemical Industry Co., Ltd., trade name "Oil Sulfur"), using a rubber kneading machine After kneading for about 120 seconds until it reached the limit temperature of 135°C during kneading, the obtained mixture was molded in the following manner, and then cut to obtain a long rubber sheet of the same size as in Example 1. The JIS-A hardness of the rubber sheet is 80°.

As a forming method, the following method is adopted: the kneaded raw rubber is processed into a 1.6mm thick raw rubber sheet using a calendering calender, and the raw rubber sheet is set in a 1.5mm thick × 400mm × 100mm area stamper. , Extrusion cross-linking at 130°C for 30 minutes to obtain a rubber cross-linked sheet.

(Comparative example 2)

100.00 parts by weight of hydrogenated NBR (manufactured by ZEON, trade name "Zetpol 2021"), and 6.00 parts by weight of organic peroxide (manufactured by NOF Corporation, trade name "Parosimone ( Peroxymon F40"), 3.00 parts by weight of trimethylolpropane trimethacrylate (manufactured by Seiko Chemical Co., Ltd., trade name "Hi-Cross (Hi-Cross) M"), and 1.00 parts by weight of zinc stearate ( Kawamura Chemical Industry Co., Ltd., trade name "stearic acid"), 60.00 parts by weight of carbon black (Showa card Produced by Showa Cabot, trade name "IP200"), and 10.00 parts by weight of zinc oxide (manufactured by Nippon Chemical Industry Co., Ltd., trade name "zinc oxide"), are kneaded using a rubber kneader for approximately 120 seconds until After reaching the limit temperature of 135°C at the time of kneading, the obtained mixture was molded in the following manner, and then cut to obtain a long rubber sheet of the same size as in Example 1. The JIS-A hardness of the rubber sheet is 80°.

The forming method adopts the following method: use a calender to process the kneaded raw rubber into a 1.6mm thick raw rubber sheet, and set the raw rubber sheet in a 1.5mm thick×400mm×100mm area stamper, Extrusion crosslinking was performed at 130°C for 30 minutes to obtain a rubber crosslinked sheet.

(Comparative example 3)

100.00 parts by weight of EPDM (manufactured by Mitsui Chemicals, trade name "EPT4045M"), 3.00 parts by weight of diethylene glycol (manufactured by Mitsubishi Chemical Corporation), and 3.00 parts by weight of ethylene glycol (manufactured by Kyoeisha Chemical Co., Ltd.) Light Ether EG"), 5.00 parts by weight of paraffin oil (manufactured by Idemitsu Kosan Co., Ltd., trade name "paraffin oil H"), 50.00 parts by weight of silica (manufactured by Tosoh Corporation, trade name "Nip Nipsil VN3"), 5.00 parts by weight of zinc oxide (manufactured by Nippon Chemical Industry Co., Ltd.), and 5.00 parts by weight of titanium oxide (manufactured by Sakai Chemical Industry Co., Ltd.), are kneaded for approximately 180 seconds with a rubber kneader until After reaching the limit temperature of 155°C during kneading, the obtained mixture was molded in the following manner, and then cut to obtain a long rubber sheet of the same size as in Example 1. The JIS-A hardness of the rubber sheet is 70°.

The forming method adopts the following method: using a calendering machine to process the kneaded raw rubber into a 1.6mm thick raw rubber sheet, and then set the raw rubber sheet in a 1.5mm thick x 600mm x 100mm area stamper, Extrusion crosslinking was performed at 160°C for 30 minutes to obtain a rubber crosslinked sheet.

(Comparative Example 4)

The MDI-PCL-based thermoplastic polyurethane (manufactured by Miractran, Japan, trade name "E595PNAT") was molded by the following method, and then cut to obtain a long strip of the same size as in Example 1. Urethane tablets. The JIS-A hardness of the urethane sheet was 93°.

The molding is performed by extruding a sheet having a thickness of 1.5 mm and a width of 200 mm using an extruder using a T die with an injection width of 200 mm. At this time, the temperature of the mold was set to 190°C.

(Comparative Example 5)

To 100.00 parts by weight of MDI-PTMG prepolymer (manufactured by Tosoh Corporation, trade name "Coronate (Coronate) 4362") heated to 110°C, 4.41 parts by weight of 1,4-BD (Mitsubishi Chemical Corporation), 1.10 parts by weight of TMP (manufactured by Mitsubishi Gas Co., Ltd.) were stirred and mixed to prepare a urethane composition. Put the immediately obtained urethane composition into a centrifugal molding machine, cross-link it under the conditions of a mold temperature of 150°C and a cross-linking time of 60 minutes, and mold a cylindrical hardened product with a thickness of 1.5 mm After that, demoulding is carried out. Then, one part of the cylindrical cured product was cut and expanded into a plate shape, and post-crosslinking was carried out in a blower oven at 110°C for 24 hours to obtain a full width made of polyurethane sheet.

Then, the whole sheet was cut into a length of 12 mm × a width of 49 mm to form a long urethane sheet. The JIS-A hardness of the urethane sheet was 70°.

(Comparative Example 6)

To 100.00 parts by weight of MDI-PCL prepolymer (manufactured by Sanyo Chemical Co., Ltd., trade name "Sanprene P-6903") heated to 110°C, 6.17 parts by weight of 1,4-BD ( Mitsubishi Chemical Corporation) and 1.54 parts by weight of TMP (Mitsubishi Gas Corporation) were stirred and mixed to prepare a urethane composition. Put the immediately obtained urethane composition into a centrifugal molding machine, cross-link it under the conditions of a mold temperature of 150°C and a cross-linking time of 60 minutes, and mold a cylindrical hardened product with a thickness of 1.5 mm After that, demoulding is carried out. Then, one part of the cylindrical cured product was cut and expanded into a plate shape, and post-crosslinking was carried out in a blower oven at 110°C for 24 hours to obtain a full width made of polyurethane sheet.

Then, the whole sheet was cut into a length of 12 mm × a width of 49 mm to form a long urethane sheet. The JIS-A hardness of the urethane sheet was 77°.

(Comparative Example 7)

100.00 parts by weight of DEG-PES (manufactured by Tosoh Corporation, trade name "Nippollan 4706") and 22.20 parts by weight of carbodiimide modified MDI (manufactured by Mitsui Chemicals, trade name "Taco Takenate LSI-14P"), use a stirrer for mixing. Then, 6.70 parts by weight of BHEB (manufactured by Mitsubishi Fine Chemicals Co., Ltd.) and 0.50 parts by weight of TMP (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were added to the obtained mixture, and stirred and mixed to prepare a urethane composition. Then, the obtained urethane composition was put into a centrifugal molding machine, and the It was cross-linked under the conditions of a temperature of 150°C and a cross-linking time of 60 minutes, and after molding a cylindrical hardened product with a thickness of 1.5 mm, it was demolded. Then, one part of the cylindrical cured product was cut and expanded into a plate shape, and post-crosslinking was carried out in a blower oven at 110°C for 24 hours to obtain a full width made of polyurethane sheet.

Then, the whole sheet was cut into a length of 12 mm × a width of 49 mm to form a long urethane sheet. The JIS-A hardness of the urethane sheet was 67°.

(Comparative Example 8)

Except that the blending amount of carbodiimide-modified MDI was changed to 32.20 parts by weight, and the blending amount of BHEB was changed to 13.00 parts by weight, a long urethane was obtained in the same manner as in Comparative Example 7. sheet. The JIS-A hardness of the urethane sheet was 85°.

(Comparative Example 9)

Except that the compounding amount of 1,4-BD was changed to 3.82 parts by weight and the compounding amount of TMP was changed to 2.54 parts by weight, a long urethane sheet was obtained in the same manner as in Example 1. The JIS-A hardness of the urethane sheet was 65°.

Regarding the rubber sheet and the urethane sheet produced in Comparative Example 1 to Comparative Example 9, the formulation and the JIS-A hardness are shown in Table 2.

[Evaluation of Coolant Resistance]

Regarding the sheets (urethane sheet or rubber sheet) produced in the Examples and Comparative Examples, the durability against the coolant was evaluated.

Here, the following three types of coolants were used to evaluate the durability of these coolants.

Coolant A (oil series): Trade name "Daphne Marg Plus MP10" (manufactured by Idemitsu Kosan Co., Ltd.)

Coolant B (water system): 10-fold dilution product of the trade name "Clear Cut R-H-1K" (manufactured by Neos)

Coolant C (aqueous): a 10-fold dilution of the trade name "Neocool Bio-60E" (manufactured by Moresco)

(Evaluation method)

The sheets produced in the examples and comparative examples were immersed in the coolant A to the coolant C for a predetermined time (0 hour, 72 hours, and 520 hours), respectively, and the weight increase rate (%) of the sheet during dipping was calculated.

Here, in the 0-hour immersion, the sheet was immersed in the coolant, and then the sheet was immediately pulled out. In addition, coolant A to coolant C are used as coolants at room temperature and 50°C, respectively. In addition, the weight is measured by pulling the sheet from the coolant, and quickly using a paper towel to wipe the coolant.

The results are shown in Table 3, Table 4, and Figs. 4(a) to 6(b).

Fig. 4(a) and Fig. 4(b) are graphs showing the immersion time and weight increase rate when the sheet is immersed in coolant A (50°C). The evaluation results of Example 1 to Example 7 are shown in FIG. 4(a). Figure 4(b) shows Comparative Example 1 ~ Evaluation result of Comparative Example 9.

Fig. 5(a) and Fig. 5(b) are graphs showing the immersion time and weight increase rate when the sheet is immersed in coolant B (50°C). The evaluation results of Example 1 to Example 7 are shown in FIG. 5(a). The evaluation results of Comparative Example 1 to Comparative Example 9 are shown in FIG. 5(b).

Fig. 6(a) and Fig. 6(b) are graphs showing the immersion time and weight increase rate when the sheet is immersed in coolant C (50°C). The evaluation results of Example 1 to Example 7 are shown in FIG. 6(a). The evaluation results of Comparative Example 1 and Comparative Example 2 are shown in FIG. 6(b).

Then, based on the weight increase rate, the sheets produced in the examples and comparative examples were classified into "good", "swelling", and "dissolution" based on the following criteria. The results are shown in Table 3 and Table 4.

Good: The weight increase rate is -5%~+5%.

Swelling: The weight increase rate is greater than 5%.

Dissolution: The weight reduction rate is greater than 5% (weight increase rate <-5%).

In addition, as an index of the coolant resistance, "weight increase rate (%) in 520h/weight increase rate (%) in 72h" was calculated. The results are shown in Table 3 and Table 4. Based on this index, the coolant resistance of the sheet can also be evaluated. In this index, the closer the calculated value is to 1.0, the better the coolant resistance.

As shown in Table 3, Table 4 and Figure 4(a)~Figure 6(b), the polyol component is polyethylene adipate polyol (PEA) and the JIS-A hardness is 67° or more in Example 1~ The elastomer member of Example 7 has good coolant resistance with respect to any one of the water-insoluble cutting oil and the water-soluble cutting oil. In contrast, the elastomer members (or rubber members) of Comparative Examples 1 to 9 were confirmed to be swollen or eluted by any kind of coolant.

[Actual Evaluation]

The sealing member for machine tools which used the elastomer member (rubber member) of the same composition as the urethane sheet of Example 2 and the rubber sheet of Comparative Example 1, as an elastic member, was produced.

Specifically, regarding the urethane sheet of Example 2, first, the cross-linked sheet was cut to a size of 20 mm×600 mm, and bonded to a metal support having a thickness of 1.2 mm and a length of 900 mm. Then, the end is cut to the necessary length and angle, and the mounting hole is opened to form a sealing member.

On the other hand, regarding the rubber sheet of Comparative Example 1, first, a raw rubber sheet and a metal support were set in a mold (approximately 2mm thickness×32mm width×1200mm length) heated to 150°C in a lip seal shape. Pressurized and heated for 30 minutes to extrude and crosslink to obtain an integrally molded product of rubber and support. Then, the end is cut to the necessary length and angle, and the mounting hole is opened to form a sealing member.

The obtained sealing member for machine tools was installed as a lip seal (tip squeeze amount at the time of installation: 3 mm) on a CNC lathe (manufactured by DMG Mori Seiki Co., Ltd., NLX3000), and operated for 800 hours. Observe work before and after operation The edge of the mechanical seal member. The results are shown in Figs. 7 and 8.

Fig. 7 is a photograph (left side) and a schematic diagram (right side) of the state of the edge portion when the urethane sheet of Example 2 is used as the elastic member 32 as the sealing member for machine tools. The upper part is before operation. The lower part is after operation.

Fig. 8 is a photograph (left side) and a schematic diagram (right side) of the state of the edge portion when the rubber sheet of Comparative Example 1 is used as the elastic member 32 for the sealing member for machine tools. The upper section is before operation, and the lower section is after operation. .

The sealing member for machine tools using the elastomer member having the same composition as the urethane sheet of Example 2 as the elastic member 32 is shown in FIG. 8 and only slightly abraded. In contrast, a sealing member for machine tools using a rubber member having the same composition as the rubber sheet of Comparative Example 1 as the elastic member 32, as shown in FIG. 9, was greatly worn (approximately 1 mm). From these circumstances, it is clear that an elastomer member (elastic member) using PEA as a polyol component has excellent durability.

Claims (1)

A sealing member for a machine tool, comprising a supporting member and an elastic member integrated with the supporting member, wherein the elastic member is exposed to a coolant, and the elastic member includes a thermosetting polyurethane composition The thermosetting polyurethane composition contains a polyol component, an isocyanate component and a crosslinking agent, the polyol component is a polyethylene adipate polyol, and the isocyanate component is Aromatic isocyanate, and the Japanese Industrial Standard-A hardness of the hardened product is 67° or more.

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