WO2007088802A1

WO2007088802A1 - Belt for papermaking machine

Info

Publication number: WO2007088802A1
Application number: PCT/JP2007/051362
Authority: WO
Inventors: Tsutomu Ishii
Original assignee: Ichikawa Co., Ltd.
Priority date: 2006-01-31
Filing date: 2007-01-29
Publication date: 2007-08-09
Also published as: EP1985750A4; US20090038770A1; JP2007204862A; EP1985750A1; CN101374996B; CN101374996A; JP4827542B2; DE602007003195D1; EP1985750B1

Abstract

This invention provides a belt for a papermaking machine that has excellent properties such as excellent crack resistance, abrasion resistance, and hair crack resistance. The belt for a papermaking machine comprises a substrate and an outer peripheral surface stacked on the substrate in its felt side. The outer peripheral surface comprises an intermediate layer in contact with the substrate and an outermost layer located on the outer periphery of the intermediate layer. The intermediate layer is formed of polyurethane cured with dimethylthiotoluenediamine. The outermost layer is formed of cured polyurethane cured with a curing agent other than dimethylthiotoluenediamine, or a heat curing resin selected from epoxy resins and unsaturated polyester resins. A drainage gutter is provided by cutting on the outer peripheral surface. The bottom of the drainage gutter is cut to a position which is deeper than the boundary surface between the intermediate layer and the outermost layer.

Description

Specification

Paper machine belt

Technical field

The present invention relates to a papermaking machine belt (hereinafter sometimes simply referred to as “belt”). More specifically, it is a papermaking machine belt having a multilayer outer peripheral surface and excellent physical properties such as crack resistance, abrasion resistance, and permanent set.

Background art

[0002] In a paper mill, a belt for a paper machine made of a substrate and polyurethane is used in each manufacturing process. In other words, a shrew press belt or a transfer belt is used in the press part of the papermaking process, and a soft force render belt is used in the calendar part.

[0003] These belts are basically composed of a base made of woven fabric or the like and polyurethane laminated on both sides or one side of the base in order to develop the strength of the entire belt. In order to manufacture such a belt, a process in which a liquid urethane prepolymer is applied to a substrate, impregnated, and cured with a curing agent is taken.

[0004] In polyurethane for papermaking machine belts, the force used by various types of polyurethane depending on the use part and application of the papermaking process, etc. High physical properties are required because of the strength and pressure between rolls and between rolls and press shoes. In recent years, the operating environment has become increasingly harsh in recent years due to the increase in the operating speed of paper machines due to the improvement in paper productivity and the high pressure in the press section. Belts used in such high-performance paper machines are required to have a higher level of performance. Generally, a papermaking machine belt is required to have physical properties such as wear resistance, permanent set, crack resistance, and compression fatigue resistance.

[0005] As described above, the belt is formed by laminating polyurethane on both surfaces or one surface of the base. In both surfaces, the outer peripheral surface is in contact with the felt side, and the inner peripheral surface is in contact with a press roll or press shoe. Among them, the outer peripheral surface laminated on the felt side is subjected to severe pressure, and the drainage is usually provided with a drainage groove in order to increase the dewatering efficiency, so the bottom of the drainage groove and its edge force Crap This is easy to generate. Further, there is a problem that the surface of the convex portion located between adjacent drain grooves is easily worn. Therefore, there is a great demand for improvement in crack resistance and wear resistance among polyurethanes constituting the belt, particularly polyurethane used as the outer peripheral surface.

[0006] In the polyurethane production method, a diisocyanate having two isocyanate groups at the terminal and a polyol having a plurality of hydroxyl groups at the terminal are subjected to a polyaddition reaction to first produce a urethane prepolymer having an isocyanate group at the terminal. . The liquid urethane prepolymer obtained by force is low in molecular weight, and is cured by adding a curing agent (chain extender) thereto and heating to obtain a solid high molecular weight polyurethane.

[0007] The selection of the curing agent for the production of high molecular weight polyurethane is important as it greatly affects the properties of polyurethane. Typical examples of curing agents for papermaking polyurethanes are dimethylthiotoluenediamine (DMTDA) and methylenebisorthochloroaline (M BOCA), both of which are frequently used. Among them, MBOCA is excellent in wear resistance, and D MTDA is particularly excellent in crack resistance. Crack resistance is an important property for papermaking belts, and DMTDA is often used for applications where crack resistance is important.

[0008] For example, in Patent Document 1, when DMTDA is used as a polyurethane curing agent for a papermaking machine belt, a papermaking machine belt that balances crack resistance, wear resistance, and permanent distortion resistance is obtained. Is provided.

[0009] However, there is a strong crack as a crack generated in the belt, and in addition to a normal crack due to an external force, there is a small hair-like crack generated on the surface of a convex portion located between adjacent drain grooves, a so-called hair crack. However, there is a defect that hair cracks are easily generated. When this hair crack force is evenly generated on the belt convex surface, the surface roughness increases, and as a result, frictional wear increases. Furthermore, the papermaking belt is usually provided with drainage grooves on the outer peripheral surface to discharge the squeezed water, but there is a phenomenon that the edge of the convex surface located between adjacent drainage grooves may be lost. The phenomenon tends to occur more easily with DMTDA cured products.

[0010] On the other hand, a cured product of MBOCA has a defect that it is excellent in wear resistance and easily generates cracks. Also, as a belt for paper machines, it is usually high to improve wear resistance. The ability to select polyurethane with hardness It was known that cracks were even more likely to occur in DMTDA cured products and MBOCA cured products. In other words, improvement in wear resistance and prevention of cracks are generally contradictory properties, and it was considered difficult to solve both at once.

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-52204

Disclosure of the invention

Problems to be solved by the invention

As a result of studying this point, the inventors of the present invention have found that cracks often occur at the bottom of drainage grooves provided in the polyurethane resin layer on the outer peripheral surface of the polyurethane and the edge force thereof, and Since it is necessary to pay attention to the hair cracking property and wear resistance of the belt convex part surface, the resin layered on the outer periphery (felt side) of the base is composed of two or more layers, and the layer that is in direct contact with the substrate ( A material excellent in crack resistance is laminated on the intermediate layer (hereinafter referred to as an intermediate layer), and a material having good wear resistance and hair crack resistance is laminated on the outer periphery thereof, and the outermost layer on the outer peripheral surface (hereinafter simply referred to as the outermost layer). When the drainage groove is provided on the outer peripheral surface, the drainage groove is cut so that the bottom of the drainage groove is deeper than the boundary surface between the intermediate layer and the outermost layer. It is a crack-resistant material, and the outermost layer is wear-resistant and hair-resistant. It was found that a belt with excellent crack resistance, wear resistance, and hair crack resistance can be obtained.

[0013] Specifically, the intermediate layer is laminated with DMTDA cured polyurethane, and the outermost layer is selected from a curing agent other than DMTDA, for example, polyurethane cured with MBOCA, epoxy resin, unsaturated polyester resin. Laminated thermosetting resin.

That is, the present invention relates to a papermaking machine belt in which the outer peripheral surface is laminated on the felt side of the substrate, and includes an intermediate layer whose outer peripheral surface is in contact with the substrate and an outermost layer located on the outer periphery thereof. The interlayer is a polyurethane cured with dimethylthiotoluenediamine, and the outermost layer is selected from a cured polyurethane cured with a curing agent other than dimethylthiotoluenediamine, or an epoxy resin or an unsaturated polyester resin. The drainage groove is cut on the outer peripheral surface, and the bottom of the drainage groove is cut deeper than the boundary surface between the intermediate layer and the outermost layer. Is a belt for papermaking machines.

The invention's effect [0015] The papermaking machine belt of the present invention has a thermosetting resin selected from a polyurethane hardened with a hardener other than DMTDA, such as MBOCA, an epoxy resin, or an unsaturated polyester resin, as the outermost layer. As a result, the wear resistance and hair crack resistance are excellent. In addition, the drainage groove is cut to a position deeper than the boundary surface between the two layers, and the DMTDA-cured polyurethane in the intermediate layer is exposed at the bottom and the edge of the drainage groove. The convex surface located between the adjacent drainage channels that are difficult to generate is the outermost layer material, so it is possible to prevent the edge from being damaged. In this manner, a papermaking machine belt superior to those conventionally used in all aspects of crack resistance, wear resistance, and hair crack resistance is provided.

BEST MODE FOR CARRYING OUT THE INVENTION

The structure of the papermaking machine belt of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of the belt 1, in which a shoe-side resin layer 3 is laminated on the inner peripheral surface of the substrate 2 and a felt-side resin layer 4 is laminated on the outer peripheral surface.

The felt-side resin layer 4 on the outer peripheral surface is composed of an intermediate layer 5 and an outermost layer 6. The intermediate layer 5 is in contact with the substrate and the outermost layer 6 is laminated on the outer side. The belt is provided with a plurality of drain grooves 7 in the running direction. Since the drainage groove 7 is cut so as to be deeper than the boundary surface 9 between the intermediate layer 5 and the outermost layer 6, the exposed intermediate layer 5 forms the bottom surface 8 of the drainage groove 7 and its edge. Yes.

[0017] The belt outer peripheral surface obtained by such a laminating method and the installation of drainage grooves is composed of an intermediate layer 5 and an outermost layer 6. The outermost layer 6 in contact with the felt side in a papermaking machine has an outer layer other than DMTDA. Polyurethane cured with a curing agent, such as MBOCA cured polyurethane, or thermosetting resin selected from epoxy resin and unsaturated polyester resin. The generation of cracks and edge defects on the surface of the convex part is suppressed. On the other hand, since the drainage groove 7 is cut to a position deeper than the boundary surface 9 between the intermediate layer 5 and the outermost layer 6, the bottom 8 and its edge are DMTDA-cured polyurethane having excellent crack resistance. Hard to occur.

[0018] Of the felt-side resin layer 4 that is the outer periphery of the belt of the present invention, the intermediate layer 5 is provided with DMTDA-cured polyurethane, and the outermost layer 6 is particularly required to have wear resistance and hair crack resistance. Ru . As the material of the outermost layer 6, a thermosetting resin selected from polyurethane cured with a curing agent other than DMTDA, epoxy resin, and unsaturated polyester resin is used.

In the papermaking machine belt, in addition to the felt-side resin layer 4 constituting the outer peripheral surface of the substrate 2, a shoe-side resin layer 3 is also laminated on the normal side of the substrate 2. As the outer side resin layer 3, the thermosetting polyurethane is most often used as in the outer peripheral surface.

[0020] Further, as the substrate, in addition to the force normally used for woven fabrics, those obtained by superimposing the two without being woven, films and knitted fabrics, and those obtained by winding a strip of narrow width in a spiral are used.

[0021] The polyurethane of the intermediate layer reacts with polyol and diisocyanate to form a urethane prepolymer, and then mixed with a curing agent (chain extender), and then applied to a substrate, followed by drying and curing (heating) However, a high molecular weight polyurethane is obtained.

[0022] Polyols that are raw materials for producing urethane prepolymers include, for example, polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly force prolatathone ester, polycarbonate, polyethylene adipate, polybutylene adipate, polyhexene A polyester polyol such as adipate is used.

[0023] The diisocyanate used as a raw material for the urethane prepolymer includes tolylene diisocyanate (TDI), diphenolmethane diisocyanate (MDI), m-xylene diisocyanate, naphthalene diisocyanate, etc., usually polyurethane Any known raw material can be used, but TDI and MDI are particularly preferred. MDI has various isomers, but the 4,4 'isomer is most preferred. A mixture of TDI and MDI can also be used.

[0024] In a reaction for producing a urethane prepolymer from a polyol and a diisocyanate, the mixing ratio of the two is such that the equivalent ratio of isocyanate group ZOH group is 1.3 / 1 to 4/1, preferably 1.4 / 1 to 1.6 / 1. It is preferable that

[0025] The reaction product contains a large amount of unreacted diisocyanate and a solvent, and is removed by distillation. Prepolymers are obtained as distillation residues.

[0026] Dimethylthiotoluenediamine, which is a hardener, has various isomers due to substitution positions of dimethylthio group and amino group, and can be used in the form of a mixture of these isomers. It is available as ETHACURE300 (trade name) manufactured by Albemarle.

[0027] Methylenebisorthochloroaline, a hardener, is available as Iharacamine MT (trade name) manufactured by Ihara Chemical.

[0028] It is desirable that the urethane prepolymer and the curing agent are mixed at a mixing ratio such that the equivalent ratio of the active hydrogen group of the curing agent to the isocyanate group of the urethane prepolymer is 0.9 to 1.10.

[0029] The curing reaction with the curing agent can be performed by a known method. The temperature of the curing reaction is usually 20 to 150 ° C, preferably 90 to 140 ° C, and it is preferable to carry out the reaction for at least 30 minutes.

[0030] The urethane prepolymers generally have a low viscosity, and a high molecular weight polyurethane can be obtained by extending the chain with a curing agent (chain extender). The multilayer polyurethane of the present invention and the substrate 2 In order to manufacture a belt for a papermaking machine comprising, a belt substrate 2 such as a woven fabric is first impregnated with a mixture of a urethane prepolymer and a curing agent for forming the intermediate layer 5, and then dried and cured (may be heated). ) To form an intermediate layer 5, and then the outermost layer 6 also includes a mixture of urethane prepolymer and a curing agent, or a thermosetting resin selected by epoxy resin, unsaturated polyester resin, etc. As shown in Fig. 1, polyurethane layer force is applied to the inner peripheral surface of the base 2 and the outer peripheral surface composed of the intermediate layer 5 and the outermost layer 6 is impregnated and laminated on the opposite side. A belt is obtained.

[0031] When a thermosetting polyurethane is used for the outermost layer 6, the types of the raw material polyol and diisocyanate, their mixing ratio, reaction temperature, etc. are almost the same as those in the intermediate layer 5, but the curing agent A curing agent other than dimethylthiotoluenediamine (DMTDA) is used. Such curing agents include aromatic diamines (methylene bis-orthochloroarine (M BOCA), trimethylene bis bis 4-amino benzoate, 1,2-bis- (2 amide phenol thio) ethane, methylene diamine. Phosphorus salt-sodium complex, trimethylene glycol-di-paraaminobenzoate), aliphatic polyols (1,4-butanediol, trimethylpropane), aromatic polyols (hydride quinone quinone jetolol ether) In particular, MBOCA is preferable from the viewpoint of wear resistance, hair crack resistance, and the like.

[0032] The outermost layer 6 is made of other than polyurethane, such as epoxy resin and unsaturated polyester resin. Thermosetting rosin can also be used. As the epoxy resin, bisphenol A type epoxy resin obtained by condensation of bisphenol A and epichlorohydrin and cured with a curing agent such as aliphatic amine, aromatic amine or acid anhydride is preferred or not. Saturated polyester resin includes an unsaturated dicarboxylic acid, darlicol, an unsaturated polyester obtained by force, and a polymerizable vinyl monomer such as styrene, which is cured with a radical initiator such as an organic peroxide. Saturated polyester resin is preferred. Among the above-described thermosetting resins, epoxy resins are suitable particularly when used for the outermost layer 6 as in the present invention.

[0033] An unsaturated polyester resin that is a thermosetting resin is Adeka Resin EP4100 manufactured by Asahi Denki Co., Ltd.

It is available as (trade name).

[0034] Another thermosetting resin, bisphenol A type epoxy resin, is available as Nippona Pica 4516P (trade name).

A method of laminating polyurethane resin on both surfaces of the substrate 2 is performed by the following steps as shown in FIGS.

[0036] (Process 1)

As shown in FIG. 2, the base 2 is placed between the rolls 20 and 21, and the roll is rotated, while the roll is rotated, the urethane prepolymer that becomes the shear side resin layer 3 on the base 2 and the curing agent dimethylthiotolamine ( DMTDA) is applied to the resin coating nozzle 22 as well, and the shear-side resin layer 3 is dried and cured (may be heated).

[0037] (Process 2)

After drying / curing the shear-side resin layer 3, the front and back of the substrate 2 are reversed, and as shown in FIG. 3, the urethane that forms the intermediate layer 5 on the other surface of the substrate 2 on which the shoe-side resin layer 3 is laminated. A mixture of a prepolymer and a curing agent, DMTDA, is applied and dried and cured (which may be heated) to form the intermediate layer 5. Further, from the upper part of the intermediate layer 5 shown in FIG. 3, a mixture of a urethane prepolymer that is the outermost layer 6 (not shown) and MBOCA, which is a curing agent, is applied and dried (cured) (heated). The felt-side resin layer 4 composed of the intermediate layer 5 and the outermost layer 6 is sequentially formed.

[0038] For the outermost layer 6, a thermosetting resin selected from epoxy resin and unsaturated polyester resin is used. If the product is commercially available as an uncured liquid resin, such as a condensate of bisphenol A and epichlorohydrin, or a mixture of an unsaturated polyester and a polymerizable butyl monomer, a curing agent or radical The outermost layer can be formed by adding an initiator and heating and curing in the same manner as in the curing of the urethane prepolymer.

[0039] After the felt-side resin layer 4 is formed on the outer peripheral surface of the substrate 2, the drainage groove 7 is formed. The drainage groove 7 is formed by cutting in the belt running direction using a rotary blade or the like. In the present invention, it is necessary to expose the DMTDA cured polyurethane as the intermediate layer 5 to form the bottom of the drainage groove 7 and the edge thereof, and as shown in FIG. Cutting is performed so as to be deeper than the boundary surface 9 between the intermediate layer 5 and the outermost layer 6.

[0040] In terms of the relative thickness of each layer on the outer peripheral surface, the intermediate layer 5 is preferably 40 to 90, particularly 50 to 80, with respect to the total thickness 100 of the felt-side resin layer 4, and the outermost layer. 6 is preferably 60 to 10, in particular 50 to 20. If the thickness of the intermediate layer 5 is too large (if the thickness of the outermost layer 6 is too small), the wear of the outermost layer 6 progresses while the belt is in use, and the time when the intermediate layer 5 is exposed to the belt surface comes earlier. Conversely, if the thickness of the middle layer 5 is too small (if the thickness of the outermost layer 6 is too large), the boundary surface 9 between the middle layer 5 and the outermost layer 6 approaches the bottom 8 of the drainage groove 7, so that the bottom 8 and its Unfavorable because cracks near the edge or adjacent groove walls may occur.

[0041] In the present invention, the depth of the drainage groove 7 is 40 to 70, preferably 50 to 60 with respect to the relative ratio 100 as the thickness of the felt-side resin layer 4, and the boundary surface 9 is the drainage groove 7. Drain groove 7 is cut so as to form a part of the wall. The depth to the bottom 8 of the interface force is preferably 10 to 90, particularly 40 to 60 with respect to the depth 100 of the drainage groove 7. If the depth of the drainage groove 7 is deeper than this, it is not preferable because a force crack may occur near the bottom 8 or its edge or adjacent groove wall. On the contrary, if the depth is smaller than this, the dewatering efficiency of the belt is lowered, which is not preferable.

[0042] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In each example and comparative example, the intermediate layer and The urethane prepolymer, the curing agent and the thermosetting resin used as the material of the outermost layer are as follows.

(1) Urethane prepolymer:

Uses "Takenate L2395 (Takeda Pharmaceutical)"

(2) Curing agent DMTDA: Albemarle "ETHACURE300" (80 parts Z20 parts mixture with 3,5-dimethylthio 2,4-toluenediamine Z3,5-dimethylthio 2,6-toluenediamine)

(3) Curing agent MBOCA: "Iharacamine MT" (Methylenebisorthochlorine dilin) manufactured by Ihara Chemical

(4) Thermosetting resin:

Adeka Resin EP4100 "(Asahi Denka Co., Ltd.): Bisphenol A type epoxy resin obtained by condensation of bisphenol A and epichlorohydrin

[0043] [Example 1]

(Lamination of inner surface polyurethane)

DMTDA was prepared as a curing agent, and urethane prepolymer was mixed so that the HZNCO equivalent ratio was 0.97.

(Prebomer application)

As shown in FIG. 2, the base 2 is passed between the rolls 20 and 21, and the inner surface (shew side) of the resin 3 is formed on the base 2 from the resin application nozzle 22 while rotating the roll. Apply a mixture of the urethane prepolymer and the curing agent, and dry and cure the side-side resin 3.

[0044] (Lamination of middle layer polyurethane)

Next, the front and back of the substrate 2 are turned over, and as shown in FIG. 3, a mixture of urethane prepolymer and intermediate hardener DMTDA to be the intermediate layer 5 is applied to the other side of the substrate 2 and dried and cured.

[0045] (Lamination of outermost polyurethane layer)

When the intermediate layer 5 is cured and fluidity is lost, the urethane prepolymer and the MBO CA curing agent are mixed so that the HZNCO equivalent ratio is 0.97, and the mixture is applied to the upper force of the intermediate layer 5 After the outermost layer 6 is formed, it is dried and cured. Thereafter, the reaction was carried out at 100 ° C. for 3 hours by the heat source 23 provided above, whereby the inner peripheral surface polyurethane, the intermediate layer polyurethane, and the outermost layer polyurethane were completely cured. As a result, a belt was obtained in which one layer was laminated on the inner peripheral surface of the substrate 2 and two layers of the intermediate layer 5 and the outermost layer 6 were laminated on the outer peripheral surface. The thickness of each layer on the outer peripheral surface is the thickness of the entire felt-side resin layer 4 2. Omm (100 as a relative ratio), while the intermediate layer 5 is 1.5 mm (75) and the outermost layer 6 is 0.5 mm (25 ).

[0047] After the polyurethane is cured, drainage grooves 7 having a width of 1. Om m and a depth of 1. Omm are formed on the outer peripheral polyurethane surface using a rotary blade. As a result, the layer of DMTD A cured polyurethane as the intermediate layer 5 is exposed and the bottom of the drainage groove is formed.

[0048] [Evaluation of physical properties]

The physical properties of the obtained belt sample were measured. The measuring method of physical properties is as follows.

(1) Crack

Measurement was performed using the apparatus shown in FIG. Both ends of the test piece 31 are clamped by clamp nodes 32 and 32, and the clamp hands 32 and 32 are configured to be able to reciprocate in the left and right directions in conjunction with each other. The tension applied to the specimen 31 is 3 kg / cm, and the reciprocating speed is 40 cm / sec.

In addition, the test piece 31 is sandwiched between the rotary roll 33 and the press shoe 34 so that the outer peripheral surface is in contact with the rotary roll 33, and is moved at 36 kg / cm ² by moving the press shoe in the direction of the rotary roll. Pressed.

With this device, the test piece was repeatedly reciprocated, and the number of times the test piece 31 was reciprocated until a crack occurred at the bottom and its edge was measured. Thereafter, the occurrence of hair cracks was observed on the convex surface located between the drainage grooves on the outer peripheral surface of the test piece.

[0049] (2) Abrasion resistance

The measurement was performed using the apparatus shown in FIG. In FIG. 5, the test piece 31 is attached to the lower part of the press board 35, and the lower surface (surface to be measured) is pressed by the outer peripheral surface coming into contact with the rotary roll 36. A friction piece 57 is provided on the outer periphery of the rotating roll 36, and the contact friction with the rotating roll under pressure is performed for 20 minutes at a pressure of 10 kg / cm, the rotating speed of the rotating roll of 100 m / min, and the test piece after the test. The thickness reduction amount of 31 was measured.

[0050] [Example 2]

In Example 1, MBOCA-cured polyurethane was replaced with Adeka Resin EP4100 (bisphenol A type epoxy resin), which is a thermosetting resin, as the outermost layer resin, as in Example 1. Thus, a belt sample was prepared, and the physical properties of the obtained belt sample were measured. The results are also shown in Table 1.

[0051] [Table 1]

[0052] [Comparative Example 1]

A belt sample was produced in the same manner as in Example 1 except that the outer peripheral surface was a single layer of only DMTDA cured polyurethane used as an intermediate layer in Example 1, and the physical properties of the obtained belt sample were measured. The results are also shown in Table 1.

[0053] [Comparative Example 2]

A belt sample was produced in the same manner as in Example 1 except that the outer peripheral surface was a single layer of only MBOCA cured polyurethane used as the outermost layer in Example 1, and the physical properties of the obtained belt sample were measured. The results are also shown in Table 1.

[0054] As is clear from the results in Table 1, the belt of the present invention in which the outer peripheral surface is made up of an intermediate layer of DMTDA cured polyurethane and an outermost layer of MB OCA cured polyurethane has crack resistance, Abrasion and hair crack resistance are improved in a well-balanced manner.

Compared to this, the belt of Comparative Example 1 in which the outer peripheral surface is a DMTDA-cured polyurethane single layer has good crack resistance, but has insufficient wear resistance and hair crack resistance, while the outer peripheral surface is The belt of Comparative Example 2, which is a single MBOCA-cured polyurethane layer, has good wear resistance and air crack resistance, resulting in poor crack resistance.

Industrial applicability

[0055] According to the present invention, a belt having a single outer layer polyurethane formed on the outer peripheral surface is used. As a belt for papermaking machines with excellent crack resistance, abrasion resistance, hair crack resistance, etc. is provided and durability is increased, product quality and cost reduction are expected by improving productivity in the papermaking process .

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a configuration of a papermaking machine belt of the present invention.

FIG. 2 shows a belt manufacturing process for a papermaking machine according to the present invention.

FIG. 3 shows a process for manufacturing a belt for papermaking machine according to the present invention.

[Figure 4] Crack resistance test equipment.

[Figure 5] Wear resistance test equipment.

Explanation of symbols

[0057] 1 Benoleto

2 Substrate

3 Shear side oil layer

4 Felt-side grease layer

5 Middle layer

6 Outermost layer

7 Drainage channel

8 Drain bottom

9 Interface between intermediate layer and outermost layer

20, 21 rolls

22 Grease application nozzle

23 Heat source

31 specimen

32 Clamp hand

33 Rotating roll

34 Press Shu

35 Press board

36 rotating roll Friction

Claims

The scope of the claims

[1] In a papermaking machine belt in which the outer peripheral surface is laminated on the felt side of the substrate, the outer peripheral surface includes an intermediate layer in contact with the substrate and an outermost layer positioned on the outer periphery, and the intermediate layer is cured with dimethylthiobenzene A cured polyurethane obtained by curing the outermost layer with a curing agent other than dimethylthiotoluenediamine, or a thermosetting resin selected from epoxy resin and unsaturated polyester resin, and A belt for papermaking machines, characterized in that a drainage groove is cut on the outer peripheral surface, and the bottom of the drainage groove is cut to a position deeper than the boundary surface between the intermediate layer and the outermost layer!

[2] The outermost layer is a polyurethane cured with methylenebisorthochloroaline.

The belt for papermaking machines according to 1.

[3] The papermaking machine belt according to [1], wherein the thermosetting resin is a bisphenol A type epoxy resin.