JP2007070764A - Fabric for paper manufacturing use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fabric for paper manufacturing use improved in abrasion resistance. <P>SOLUTION: The fabric has fabric yarns for paper manufacturing use as at least part thereof. In this fabric, the fabric yarns contain a matrix resin ≤500,000 in viscosity-average molecular weight, a high-molecular weight resin ≤500,000 in viscosity-average molecular weight contained in the matrix resin and an ultra-high-molecular weight resin ≥1,000,000 in viscosity-average molecular weight contained in the matrix resin, wherein the total content of the high-molecular weight resin and the ultra-high-molecular weight resin in the whole yarns is ≤30 mass%. In particular, it is preferable that the matrix resin be a reactive matrix resin consisting of at least one of polyamide resin and polyester resin and the high-molecular weight resin and the ultra-high-molecular weight resin be modified each with an unsaturated carboxylic acid-based compound (e.g. maleic anhydride). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a papermaking fabric, and more particularly to a papermaking fabric excellent in abrasion resistance, rigidity and form stability.

The papermaking fabric is formed, for example, in an endless belt shape and is used around a number of rolls. And depending on the apparatus to be used, the back surface (traveling surface) etc. which contacts dehydrating apparatuses, such as a suction box, are remarkably worn. Such wear greatly affects the durability of the papermaking fabric.
Further, in recent years, apparatuses using papermaking fabrics have been increased in speed and size, and the number of times these papermaking fabrics need to be replaced, the time and labor required for the replacement, etc. affect the production efficiency. Is getting bigger. Therefore, the demand for durability, that is, abrasion resistance of the papermaking fabric is increasing.

In order to improve the durability of the papermaking fabric, it is conceivable to increase the diameter of the fibers constituting the fabric. This can reduce damage during the manufacturing process and extend the durability time. However, on the other hand, the structure of the papermaking fabric will change, affecting the quality of the resulting product. That is, for example, when the wire diameter is increased, the thickness of the woven fabric is increased, the water content is increased, and there is a concern about adverse effects in papermaking. Therefore, for example, in a forming wire for papermaking, a change in drainage due to a change in structure occurs, which affects the product quality.
In this way, if you try to obtain durability by increasing the wire diameter, there is a limit to changing the wire diameter in order to bring about a change in product quality, leading to a fundamental solution for durability improvement. Not in.

  From such a viewpoint, conventionally, in order to improve the durability of the papermaking fabric, a papermaking wire (Patent Document 1), which is a rigid plastic yarn containing fine particles of an inorganic substance, and a coating portion comprising a specific polyamide and a silicate layer A monofilament obtained from a polyamide-based resin composition containing a predetermined amount of a layered silicate with respect to a resin containing polyamide (Patent Document 2) partially covering the core with Paper forming foam wire (Patent Document 3) and the like have been developed. However, today, in order to meet the demand for improving the production efficiency by increasing the speed of the paper machine, there is a demand for papermaking fabric yarns and papermaking fabrics that are further superior in abrasion resistance, rigidity, and form stability.

JP-A-62-250292 JP 2000-273722 A JP-A-7-331589

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a papermaking fabric excellent in wear resistance, rigidity and form stability.

The present invention is as follows.
(1) a base resin having a viscosity average molecular weight of 500,000 or less;
A high molecular weight resin having a viscosity average molecular weight of 500,000 or less contained in the matrix resin;
An ultrahigh molecular weight resin having a viscosity average molecular weight of 1 million or more contained in the base material resin,
A papermaking fabric comprising at least a portion of a papermaking fabric yarn having a total content of the high molecular weight resin and the ultrahigh molecular weight resin of 30% by mass or less based on the entire yarn.
(2) The papermaking fabric according to (1), wherein the base resin is at least one of a polyamide resin and a polyester resin.
(3) The papermaking fabric according to (1) or (2), wherein the high molecular weight resin is modified with an unsaturated carboxylic acid compound.
(4) The papermaking fabric according to any one of (1) to (3), wherein the ultrahigh molecular weight resin is modified with an unsaturated carboxylic acid compound.
(5) The above unsaturated carboxylic acid compound is at least one of maleic anhydride, maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic anhydride and itaconic acid, and derivatives thereof (3 ) Or the papermaking fabric according to (4).
(6) The papermaking fabric according to any one of (1) to (5), wherein the high molecular weight resin is a polyolefin.
(7) The papermaking fabric according to any one of (1) to (6), wherein the ultrahigh molecular weight resin is a polyolefin.
(8) The papermaking fabric according to any one of (1) to (7), wherein the papermaking fabric yarn is at least a part of a lowermost layer weft.
(9) The papermaking fabric according to any one of (1) to (8), which is a papermaking forming wire.
(10) The papermaking fabric according to any one of (1) to (9), wherein at least a part of the papermaking fabric yarn is coated with a thermosetting resin.

According to the papermaking fabric of the present invention, wear resistance, rigidity, and form stability are excellent, and excellent wear resistance and a dynamic friction coefficient suppressing effect are obtained, and high durability is obtained. Moreover, a paper product can be obtained without problems such as wire marks. Furthermore, a particularly thin paper fabric can be obtained.
When the base resin is a predetermined resin, excellent strength can be obtained, and a paper fabric having high abrasion resistance can be obtained with a small amount of use.
When the high molecular weight resin is modified with an unsaturated carboxylic acid-based compound, it can have an interaction with the base resin, and particularly excellent wear resistance and dynamic friction coefficient suppression effect can be obtained, resulting in high durability. can get.
When the ultra high molecular weight resin is modified with an unsaturated carboxylic acid compound, it can have an interaction with the matrix resin, and particularly has excellent wear resistance and dynamic friction coefficient suppression effect, and high durability Is obtained.
When the unsaturated carboxylic acid compound is a predetermined compound, particularly strong interaction is obtained, and high wear resistance and a dynamic friction coefficient suppressing effect are obtained.
When the high molecular weight resin is a polyolefin, excellent self-lubricating properties can be obtained, and particularly excellent wear resistance and dynamic friction coefficient suppressing effects can be obtained, and high durability can be obtained.
When the ultrahigh molecular weight resin is a polyolefin, excellent self-lubricating properties can be obtained, and particularly excellent wear resistance and dynamic friction coefficient suppressing effects can be obtained, and high durability can be obtained.
When the papermaking fabric yarn is used for at least a part of the lowermost weft, excellent wear resistance can be obtained and high durability can be obtained.
When the papermaking fabric is a papermaking forming wire, excellent wear resistance is obtained and high durability is obtained. Moreover, a paper product can be obtained without problems such as wire marks. Furthermore, a particularly thin paper forming wire can be obtained.
When at least a part of the papermaking fabric yarn is coated with a thermosetting resin, excellent wear resistance can be obtained and high durability can be obtained. In particular, the weaving state is stabilized.

Hereinafter, the present invention will be described in detail.
The papermaking fabric of the present invention contains a base resin having a viscosity average molecular weight of 500,000 or less, a high molecular weight resin having a viscosity average molecular weight of 500,000 or less contained in the base resin, and a base resin. An ultrahigh molecular weight resin having a viscosity average molecular weight of 1,000,000 or more, and at least a papermaking fabric yarn having a total content of the high molecular weight resin and the ultrahigh molecular weight resin of 30% by mass or less based on the entire yarn It is characterized by providing for a part.

That is, the papermaking fabric of the present invention comprises at least a portion of papermaking fabric yarn.
Further, the papermaking fabric yarn contains a base material resin, an ultra high molecular weight resin contained in the base material resin, and a high molecular weight resin contained in the base material resin.
The above-mentioned “matrix resin” is a resin that serves as a matrix for the ultrahigh molecular weight resin and the high molecular weight resin. The base resin has a viscosity average molecular weight of 500,000 or less (preferably 10,000 to 300,000, more preferably 20,000 to 150,000, usually 10,000 or more). In this range, spinning can be performed without any problem, and sufficient flexibility and strength can be obtained even when the filament is formed into a monofilament having an average diameter of 450 μm or less. For example, a viscosity average molecular weight of 8 to 110,000 is preferable for nylon 6, a viscosity average molecular weight of 3 to 50,000 is preferable for nylon 610, and a viscosity average molecular weight of 2 to 30,000 is preferable for polyethylene terephthalate.

  The kind of the base material resin is not particularly limited. That is, for example, as a base resin, polyamide resin, polyester resin, polyolefin resin, polyphenylene sulfide resin, polysulfone resin, polyethersulfone resin, polyacrylate resin, polyamideimide resin, polyimide resin , Polyvinyl acetate resin, polyurethane resin, polyether ether ketone resin, polyether resin, and polyvinylidene fluoride resin. The polyamide resin includes an aliphatic polyamide resin (such as nylon), an aromatic polyamide resin (such as an aramid resin), and a reinforced polyamide resin including an aromatic unit in a part of the main chain. Further, the polyester resin includes an aliphatic polyester resin, an aromatic polyester resin, and a reinforced polyester resin containing an aromatic unit in a part of the main chain. Of these, polyamide-based resins and / or polyester-based resins are preferable. Only one type of base material resin may be used, or two or more types may be used in combination. In addition, the base material resin may be the same as or different from the high molecular weight resin and / or the ultra high molecular weight resin.

  Examples of the polyamide-based resin include 6 nylon, 66 nylon, 610 nylon, and 612 nylon. These may be used alone, or a copolymer or blend thereof may be used. Furthermore, a copolymer with another monomer, a blend with another resin, or the like can be used for the polyamide resin. For example, a block polyether amide resin obtained by copolymerizing a polyether with the polyamide resin or a blend of the polyamide resin and a block polyether amide resin can be used. Here, as the block polyetheramide resin, specifically, a polyamide having carboxyl groups at both ends obtained by polycondensation of a polyamide-forming monomer and a dicarboxylic acid, a terminal aminopolyoxyalkylene, and an aliphatic group Examples thereof include block polyether amide resins (Japanese Examined Patent Publication No. 63-55535) obtained by polycondensation of diamines selected from diamines, alicyclic diamines, and aromatic diamines.

  The polyester resin is not particularly limited as long as it is a polyester composed of dicarboxylic acid and glycol. For example, examples of the dicarboxylic acid component include terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, and 1,4-cyclohexanedicarboxylic acid. Examples of the glycol component include ethylene glycol, propylene glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol and the like. Specifically, examples of the polyester resin include polyethylene terephthalate (PET), polypropylene terephthalate, polybutylene terephthalate (PBT), and polyethylene naphthalate. These may be used alone, or a copolymer or blend thereof may be used. Furthermore, a polyester resin can be used as a copolymer with another monomer, a blend with another resin, or the like.

In addition, this base resin preferably has a reactive group when the high molecular weight resin and / or ultrahigh molecular weight resin described later is modified with an unsaturated carboxylic acid compound. A reactive group interacts due to modification with an unsaturated carboxylic acid compound (may be a cross-linking between a base resin and a high molecular weight resin, between the base resin and the ultra high molecular weight resin, etc.) Is a group (structure part) that yields Examples of this reactive group include divalent groups such as —NHCO—, —COO—, —SO ₂ —, —CO—, —CONCO—, —NHCO ₂ —, and —OH, —NH ₂ , —NO. ₂ , monovalent groups such as —COOH, —CHO, —OR, —COOR, —CN, and the like. These reactive groups may include only one type or two or more types.

As the base material resin having the reactive group, among the various resins, a polyamide resin, a polyester resin, a polysulfone resin, a polyethersulfone resin, a polyacrylate resin, a polyamideimide resin, a polyimide resin, Examples thereof include polyvinyl acetate resins, polyurethane resins, polyether ether ketone resins, and polyether resins. Further, in addition to the above resins, various resins having a reactive group introduced may be used by modification after polymerization and / or by polymerization using a monomer having a reactive group at the time of polymerization. You can also. Furthermore, examples of the base material resin include a polyvinylidene fluoride resin having a reactive group and a polypropylene resin having a reactive group. These base resin may use only 1 type and may use 2 or more types together.
Of these, polyamide resins and polyester resins are preferred. These are excellent in balance of workability (spinning), strength when thinned (diameter of 450 μm or less, etc.), wear resistance, low dynamic friction and the like.

  The base material resin having the reactive group (hereinafter, also simply referred to as “reactive base material resin”) may be a base material resin in which all of the base material resin contained in the papermaking fabric yarn is used. Only a part of the base resin contained in the papermaking fabric yarn may be a reactive base resin. That is, the base material resin may be composed only of a reactive base material resin, or may be a mixed resin of a reactive base material resin and a non-reactive base material resin.

  The content of the reactive base resin with respect to the entire papermaking fabric yarn (100% by mass) is not particularly limited, but is 70% by mass or more (preferably 70 to 99% by mass, more preferably 80 to 90% by mass). is there. Further, the content of the base material resin (the whole base material resin regardless of the reactivity) with respect to the entire papermaking fabric yarn (100% by mass) is not particularly limited, but is usually 70% by mass or more (preferably 70 to 99% by mass). More preferably, it is 80-90 mass%). Within this range, the textile yarn for papermaking can be stably spun without becoming brittle, and the wear resistance can be effectively improved.

  The “high molecular weight resin” is a resin contained in the base material resin, and usually has a weak interaction with the base material resin. The high molecular weight resin has a viscosity average molecular weight of 500,000 or less (preferably 10,000 to 500,000, more preferably 20,000 to 250,000, usually 50,000 or more). Within this range, the abrasion resistance of the papermaking fabric yarn can be effectively improved. In particular, when an ultra high molecular weight resin and a high molecular weight resin are mixed in advance, the dispersibility between the resins is improved (more uniform dispersion), which is preferable.

  The “ultra high molecular weight resin” is a resin contained in a base resin. However, it may be contained directly in the base material resin, or may be contained indirectly in the base material resin after being contained in the high molecular weight resin. The ultra high molecular weight resin is a resin having a viscosity average molecular weight of 1,000,000 or more. The viscosity average molecular weight of the ultrahigh molecular weight resin is not particularly limited as long as it is 1,000,000 or more, and the viscosity average molecular weight is preferably as large as possible. However, it is preferable to be deformed along with the base resin during spinning. In particular, it is preferable that a spinning step is included during spinning, and the drawing step involves deformation along with the base material resin. Accordingly, the viscosity average molecular weight is preferably 1 million to 6 million, and more preferably 2 million to 4 million. Within this range, the wear resistance and rigidity can be effectively improved while preventing the papermaking fabric from becoming brittle. In general, an ultrahigh molecular weight resin having a viscosity average molecular weight of 1,000,000 or more is measured for molecular weight by a viscosity measurement method.

The ultra high molecular weight resin and the high molecular weight resin may be the same resin or different resins, but are preferably resins having affinity, and moreover, the same kind of resin (for example, In the following examples, it is preferable to use the same resin). Further, each of the ultra high molecular weight resin and the high molecular weight resin may be composed of one kind of resin, or may be composed of two or more kinds of resins.
The types of these ultra high molecular weight resins and resins constituting the high molecular weight resins are not particularly limited. For example, polyolefin resins (polyethylene, polypropylene, etc.), polyamide resins (6 nylon, 66 nylon, 610 nylon, 612 nylon, etc.) Nylon, etc.), polyacetal resins (polyoxymethylene, etc.), polyester resins (polyethylene terephthalate, polybutylene terephthalate, etc.), polyurethane resins and the like. However, the polyamide-based resin and the polyester-based resin include aliphatic resins, aromatic resins, and reinforced resins containing an aromatic unit in a part of the main chain. These ultra high molecular weight resins and resins constituting the high molecular weight resins may be used alone or in combination of two or more.

  Among these ultra high molecular weight resins and resins constituting the high molecular weight resins, polyolefin resins (particularly polyethylene), polyamide resins, polyacetal resins and polyurethane resins are preferable. Polyolefin resins, polyamide resins, and polyacetal resins are excellent in self-lubricating properties, so that the friction coefficient can be reduced, and as a result, excellent wear resistance can be obtained. In addition, polyurethane can obtain particularly excellent wear resistance. Further, polyolefin resins and / or polyamide resins are more preferable, and polyolefin resins are particularly preferable. Furthermore, it is particularly preferred that both the ultra high molecular weight resin and the high molecular weight resin are polyethylene. Polyethylene sufficiently exhibits excellent self-lubricating properties even with a small content, and has excellent impact strength and chemical resistance. Furthermore, since this polyethylene can be spun in the same manner as when polyethylene is not contained, being hardly affected by the blending amount, it is preferable in production. Normally, the base resin and the high molecular weight resin are different from each other (that is, different resins of the various resins, for example).

  Further, in the papermaking fabric of the present invention, the high molecular weight resin and the ultra high molecular weight resin are mixed in advance with the high molecular weight resin and the ultra high molecular weight resin before being mixed with the base material resin ( Further, it is preferably contained as a composite resin (modified as described later). As a result, high wear resistance, rigidity, and form stability can be obtained regardless of the inclusion form of the high molecular weight resin and the ultra high molecular weight resin in the base resin.

Further, the high molecular weight resin can be modified with an unsaturated carboxylic acid compound. Similarly, the ultra high molecular weight resin can be modified with an unsaturated carboxylic acid compound.
The “unsaturated carboxylic acid compound” is a compound having an unsaturated bond (usually an unsaturated bond between carbon atoms) that can be bonded to a polyolefin resin and a carboxylic acid group. The unsaturated bond may have only one, or may have two or more, but usually has only one. Further, the carboxylic acid group may have only one (monovalent carboxylic acid) or two or more (polyvalent carboxylic acid). Examples of the unsaturated carboxylic acid compound include maleic anhydride, maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic anhydride, itaconic acid, crotonic acid, citraconic anhydride, citraconic acid and mesaconic acid. Furthermore, derivatives of each of these unsaturated carboxylic acid compounds (however, unsaturated bonds and carboxylic acid groups remain) can be mentioned. Among these unsaturated carboxylic acid compounds, maleic anhydride, maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic anhydride and itaconic acid are preferred, and maleic anhydride and itaconic anhydride are more preferred. . Only one type of unsaturated carboxylic acid compound may be used, or two or more types may be used in combination.

  The “modification” refers to bonding an unsaturated bond of the unsaturated carboxylic acid compound to a high molecular weight resin or an ultra high molecular weight resin. The amount of modification by the unsaturated carboxylic acid compound is not particularly limited, but it is at least 0.1% by mass or more (more preferably 0.1 to 0.8% by mass) when measured by the FT-IR method. preferable. If it is this range, especially the coupling | bonding of base material resin and high molecular weight resin and the coupling | bonding of base material resin and ultra high molecular weight resin can be ensured.

In the FT-IR method, a high molecular weight resin and an ultra high molecular weight resin (for example, maleated polyethylene) modified with an unsaturated carboxylic acid compound are dissolved in hot xylene, and then reprecipitated in acetone. Then, the acetone mixture containing the precipitate is filtered, and the resulting filtrate (solid) is washed to remove unreacted maleic acid. Then, FT-IR measurement is performed by a transmission method for the high molecular weight resin and the ultrahigh molecular weight resin from which the unreacted maleic acid has been removed. Quantification is carried out from the peak (792 cm ⁻¹ ) of the C═O stretching vibration of the reaction maleic acid in the obtained infrared absorption curve. In particular, when the high molecular weight resin and the ultrahigh molecular weight resin are polyethylene, the peak of C—H bending vibration (1464.1 cm ⁻¹ ) of polyethylene is used in combination.

  When the base resin is a resin having the reactive group, the base resin and the high molecular weight resin are caused by the interaction between the unsaturated carboxylic acid compound modified to the high molecular weight resin and the reactive group. Can be firmly joined. Similarly, the matrix resin and the ultrahigh molecular weight resin can be firmly bonded by the interaction between the unsaturated carboxylic acid compound modified to the ultrahigh molecular weight resin and the reactive group. Therefore, the high molecular weight resin and the ultra high molecular weight resin are subjected only to irradiation, ultraviolet irradiation, oxidation treatment, coupling treatment and the like to improve the affinity between the base resin, the high molecular weight resin and the ultra high molecular weight resin. Furthermore, it can be made to join firmly. This prevents peeling between the base resin, the high molecular weight resin, and the ultra high molecular weight resin even during spinning (particularly when a drawing process is included), and uses non-modified high molecular weight resin and ultra high molecular weight resin. High wear resistance and the like can be obtained as compared with the case of the above. In addition, when both the ultra high molecular weight resin and the high molecular weight resin are modified with an unsaturated carboxylic acid compound, the interaction between the ultra high molecular weight resin and the high molecular weight resin can be obtained, and further excellent Abrasion resistance and a dynamic friction coefficient suppressing effect are obtained, and high durability is obtained. The papermaking fabric yarn of the present invention may be subjected to the above various affinity improving treatments in addition to the above modification.

  Further, the content of the ultra high molecular weight resin and the high molecular weight resin is such that the total content of the ultra high molecular weight resin and the high molecular weight resin is 30% by mass or less (100% by mass) with respect to the entire papermaking fabric yarn (100% by mass) Greater than 0). Within this range, the content can be varied depending on the properties required for the papermaking fabric. The total content is preferably 1 to 30% by mass, more preferably 3 to 28% by mass, more preferably 5 to 25% by mass, particularly preferably 10 to 20% by mass, and most preferably 12 to 18% by mass. is there. If it is this range, it can prevent that the textile fabric for paper manufacture becomes weak, and can improve abrasion resistance and rigidity effectively.

  Furthermore, the content of the high molecular weight resin is 10 to 40% by mass (more preferably 15 to 35% by mass, still more preferably 20%) with respect to the total amount (100% by mass) of the ultra high molecular weight resin and the high molecular weight resin. ˜32 mass%, particularly preferably 25-30 mass%). That is, the content of the ultrahigh molecular weight resin is 60 to 90 mass% (more preferably 65 to 85 mass%, still more preferably) with respect to the total amount (100 mass%) of the ultrahigh molecular weight resin and the high molecular weight resin. 68 to 80% by mass, particularly preferably 70 to 75% by mass). Within this range, the abrasion resistance of the papermaking fabric yarn can be effectively improved. In particular, when an ultra high molecular weight resin and a high molecular weight resin are mixed in advance, the dispersibility between the resins is improved (more uniform dispersion), which is preferable.

The shapes of these ultrahigh molecular weight resins and high molecular weight resins in the papermaking fabric yarn are not particularly limited. That is, for example, it may be contained in a particle shape or in an amorphous shape. When contained in a particle shape, it may be a long particle shape, a spherical shape, or other various shapes, but is usually a long particle shape. Furthermore, the major axis is arranged substantially parallel to the longitudinal direction of the papermaking fabric yarn.
The high molecular weight resin phase and the ultrahigh molecular weight resin phase are preferably smaller than the wire diameter of the papermaking fabric yarn in a cross section perpendicular to the longitudinal direction of the fiber. That is, it is preferable that the matrix resin as a continuous phase is not cut by the ultra high molecular weight resin phase and the high molecular weight resin phase. For example, the size of one phase (ultra high molecular weight resin phase and high molecular weight resin phase) in the papermaking fabric yarn in the cross section is 1 of the wire diameter of the papermaking fabric yarn (minimum diameter if the cross section is not circular). / 5 or less, more preferably 1/35 to 1/5, still more preferably 1/30 to 1/10, and particularly preferably 1/23 to 1/14. . Within this range, even if the surface of the paper fabric yarn is worn during use, each phase (particularly the ultra-high molecular weight resin phase) is exposed on the surface of the paper fabric yarn and maintains high abrasion resistance. Can do. In addition, the said magnitude | size of an ultra high molecular weight resin phase and a high molecular weight resin phase may be the same, and may differ.

  Further, when the ultra high molecular weight resin and the high molecular weight resin are respectively contained in a particle shape, the aspect ratio of each of the particles made of the ultra high molecular weight resin and the particles made of the high molecular weight resin is not particularly limited, but 3 or more (that is, , Meaning that it includes a fibrous material), more preferably 3 to 20, and particularly preferably 5 to 15. Within this range, the wear resistance and rigidity can be effectively improved while preventing the papermaking fabric from becoming brittle. Further, since the contact area with the sliding portion is wide, high wear resistance is obtained. However, it has a major axis in the longitudinal direction of the papermaking fabric yarn. In addition, in the case of having particles made of a composite resin (particles in which the form of a composite resin in which a high molecular weight resin and an ultrahigh molecular weight resin are mixed in advance before mixing with the base material resin is also maintained in the base material resin) The aspect ratio of the composite resin particles is preferably the same as described above.

The relationship among these ultra high molecular weight resins, high molecular weight resins, and matrix resins may be any of the following (1) to (5). That is,
(1) A composite resin 42 in which the ultrahigh molecular weight resin 422 is contained (preferably dispersed) in the high molecular weight resin 421 (for example, can be contained in the form of particles made of the composite resin) is contained in the base resin 41. (See FIG. 2),
(2) A part of the ultrahigh molecular weight resin 422 is contained (preferably dispersed) in the base resin 41 as a composite resin 42 contained (preferably dispersed) in the high molecular weight resin 421. The rest of the high molecular weight resin 422 is contained alone in the base resin 41 (preferably dispersed) (see FIG. 3),
(3) The composite resin 42 contained in the base material resin 41 (preferably dispersed), the ultrahigh molecular weight resin 422 contained alone (preferably dispersed), and the base material alone. A high molecular weight resin 421 contained (preferably dispersed) in the resin 41 (see FIG. 4),
(4) A form in which the ultrahigh molecular weight resin 422 and the high molecular weight resin 421 are independently contained (preferably dispersed) in the base material resin 41 (see FIG. 5),
(5) Various forms other than the above (1) to (4).
Each of FIGS. 2 to 5 is a schematic diagram showing the arrangement of each resin in an easy-to-understand manner. For example, the content ratio of each resin, the dispersed particle diameter of each resin, the dispersed shape of each resin, and the like are accurately shown. It is not a representation.

  The above-mentioned “textile yarn for papermaking” is a weft, a warp or the like constituting the papermaking fabric, and these are assembled (woven) to constitute the papermaking fabric. The form of the papermaking fabric yarn used for this papermaking fabric is not particularly limited. For example, monofilament, multifilament, spun yarn, crimped processing, bulky processing, etc., generally textured yarn, bulky yarn, stretch yarn, Examples thereof include processed yarns that are referred to, and twisted yarns obtained by combining them together. Of these, monofilaments and / or multifilaments are preferred. These papermaking fabric yarns may be used alone or in combination of two or more.

  The wire diameter of the monofilament is not particularly limited, but is usually 100 to 450 μm. This wire diameter can be, for example, 200 to 400 μm, and further can be 300 to 450 μm. Within this range, the entangled portion is transferred to the product and no mark is generated, and the durability time until the fiber is cut can be increased. On the other hand, when the papermaking fabric yarn is used, the wire diameter can be set to 100 to 200 μm, and further to 100 to 180 μm. Thus, even if the wire diameter is made thinner than conventional ones, in order to have high wear resistance, the durability for papermaking fabrics is equal to or exceeding that of conventional products (for example, wire diameter 200 to 300 μm). Obtainable.

  The multifilament is a fiber composed of a plurality of monofilaments. All of the monofilaments constituting the multifilament may be the above-mentioned papermaking fabric yarn, or only a part thereof may be the papermaking fabric yarn. The wire diameter and the number of monofilaments constituting the multifilament are not particularly limited, but the wire diameter is usually 10 to 50 μm, preferably 10 to 40 μm, and the number is usually 700 or less, preferably 200 to 700, more preferably 200 to 500.

  The cross-sectional shape of the papermaking fabric yarn is not particularly limited, and may be circular, elliptical, star-shaped, rectangular, hollow, or the like. Moreover, it is preferable that the papermaking fabric yarn has irregularities on the surface. This unevenness is an unevenness caused by containing the ultra-high molecular weight resin and / or the composite resin, and is usually long and wrinkled. One wrinkle-shaped portion composed of one convex portion is usually 10 μm or longer (more preferably 10 to 50 μm) in length. Moreover, the height is 1 micrometer or more normally (further 1-10 micrometers).

  The method for producing this papermaking fabric yarn is not particularly limited, and may be obtained by any method as long as it has the above-described configuration. In particular, a high molecular weight resin and an ultrahigh molecular weight resin are mixed in advance. It is preferable to obtain a mixed resin, further mix the obtained mixed resin with a base material resin, and spin the obtained mixture. Also, when the high molecular weight resin and the ultra high molecular weight resin are modified with an unsaturated carboxylic acid compound, the high molecular weight resin and the ultra high molecular weight resin are each modified with an unsaturated carboxylic acid compound, and then both resins are mixed. A composite resin may be obtained, or a high molecular weight resin and an ultrahigh molecular weight resin may be mixed and then modified with an unsaturated carboxylic acid compound to obtain a composite resin. In addition, for example, both a high molecular weight resin and an ultrahigh molecular weight resin can be blended into a molten base resin, and a mixture obtained by mixing can be obtained by spinning. The spinning is usually carried out by extruding the heat-melted mixture from the spinneret pores into a fibrous form. In this case, after the extrusion, stretching may be performed or stretching may not be performed, but stretching is particularly preferable.

  The average particle size of the ultrahigh molecular weight resin particles used during production is not particularly limited, but is preferably the same as or larger than the average particle size of the inorganic particles contained in the papermaking material. Examples of the inorganic particles include one or more of calcium carbonate, titanium dioxide, talc, clay, and the like. Since these particle diameters are usually 0.1 to 20 μm, the average particle diameter of the ultrahigh molecular weight resin particles before addition is preferably 20 μm or more, more preferably 20 to 50 μm, and 30 It is especially preferable that it is -40micrometer. Within this range, the above-mentioned fine particle shape can be obtained while preventing the papermaking fabric yarn from being damaged by the inorganic particles, and particularly high durability can be obtained.

  In addition, in the case of having particles composed of the above-described composite resin, it is preferable that the particles are deformed by spinning, and in particular, a spinning process is included during spinning, and it is preferable that the stretching process involves deformation along with the base resin. However, it can be added as substantially spherical particles during production. In this case, the average particle diameter of the particles composed of the composite resin before addition is not particularly limited, but is preferably 70 to 250 μm, more preferably 85 to 250 μm, and particularly preferably 100 to 150 μm. . Within this range, the high molecular weight resin and the ultra high molecular weight resin made of the composite resin can be uniformly dispersed in the base material resin.

  Further, the configuration of the papermaking fabric of the present invention is not particularly limited. That is, for example, a single layer structure or a multilayer structure may be used. Further, in the papermaking fabric of the present invention, the papermaking fabric yarn may be used in any part of the papermaking fabric. In particular, the lowermost layer weft and the lowermost layer warp (the warp yarn is exposed to the back surface). It is preferable to use it as at least a part of the yarn. That is, for example, a part of each of the lowermost layer weft and the lowermost layer warp may be the papermaking fabric yarn, and the remaining yarns may use other fibers. Furthermore, all of the lowermost layer weft and the lowermost layer warp may be used as the papermaking fabric yarn.

  Among these, it is preferable to use as at least a part of the lowermost layer wefts in the papermaking fabric of the present invention. That is, it is more preferable to use it as at least a part of the lowermost layer wefts in a papermaking fabric having a multilayer structure (usually 2 to 3 layers). Further, it is particularly preferable to use one in three or more of the lowermost layer wefts, and it is particularly preferable to use one in two or more in the lowermost layer wefts. The papermaking fabric yarn can also be used for all the lowermost layer wefts. The lowermost layer weft is arranged in a layer in contact with a lot of equipment members (rolls, etc.) in an apparatus using a papermaking fabric (that is, a layer opposite to the uppermost layer on which wet paper etc. is placed). The weft. For example, as shown in FIG. 1, when the papermaking fabric 1 has an uppermost layer weft 21, a lowermost layer weft 22, and a warp 3, it can be used as a part or all of the lowermost layer weft 22. Since the lowermost layer greatly affects the life of the papermaking fabric, it is possible to efficiently extend the life of the entire papermaking fabric by suppressing damage (wear, etc.) of the lowermost papermaking fabric yarn.

  When the papermaking fabric yarn of the present invention is used as a part of the yarns constituting the papermaking fabric, other yarns (wefts and warps) are not particularly limited, and various yarns can be used. That is, for example, polyester monofilaments, polyamide monofilaments such as the above ultra high molecular weight resins and ordinary nylon monofilaments (6 nylon, 66 nylon, 610 nylon, 612 nylon, etc.) that do not contain the above high molecular weight resins. In this case, the warp and the weft may be made of a single material, or may be made of two or more kinds of materials having different materials for each warp or weft. These fibers may use only 1 type and may use 2 or more types together.

  The papermaking fabric of the present invention may be one in which at least a part of the papermaking fabric yarn is coated with a thermosetting resin. That is, it may be a papermaking fabric obtained using a papermaking fabric yarn at least partially coated with a thermosetting resin, or a papermaking fabric obtained using an uncoated papermaking fabric yarn. It may be a paper fabric obtained by coating a thermosetting resin on the paper. The kind of thermosetting resin used for these coatings is not particularly limited, and examples thereof include epoxy resins and phenol resins. These thermosetting resins may use only 1 type and may use 2 or more types together.

  Moreover, when coating the papermaking textile yarn, the method is not specifically limited, For example, it can coat by spraying or apply | coating a solution-form or emulsion-like thermosetting resin with respect to the papermaking textile yarn. Further, when the thermosetting resin is coated on the paper fabric, the method is not particularly limited. For example, a thermosetting resin composed of a liquid thermosetting resin, or a thermosetting resin solution containing a thermosetting resin. A thermosetting resin-containing emulsion containing a dispersed thermosetting resin can be applied to a papermaking fabric (including spraying, brushing, roll coating and impregnation). Furthermore, by spraying or applying a thermosetting resin in the form of a solution or an emulsion onto the surface of the papermaking fabric in which the papermaking fabric yarn is woven as the lowermost layer weft, and then performing natural drying or heat drying with a roll dryer or the like Obtainable.

According to the method of coating the papermaking fabric in which the papermaking fabric yarn is woven, the portion where the warp and the weft contact, such as the knuckle portion, can be coated. For this reason, the warp and the weft are hardened with the resin, and the woven state can be stabilized.
Moreover, since the thermosetting resin used for coating or the liquid containing the thermosetting resin has an excessively high viscosity, it may cause problems such as clogging of the papermaking fabric and dehydrating efficiency. It is preferable to use a liquid having a low viscosity (that is, a liquid having a low content of the thermosetting resin). If necessary, the coating can be performed in multiple steps.

  Examples of the papermaking fabric of the present invention include a papermaking forming wire, a woven fabric, a knitted fabric, a felt fabric, a conveyor belt, a papermaking press felt and a joining press felt, a papermaking dryer canvas, and the like. Among these, the effect of the papermaking fabric can be obtained particularly effectively when used as a papermaking forming wire.

Hereinafter, the papermaking fabric of the present invention will be specifically described with reference to examples.
[1] Production of papermaking fabric (Examples 1 and 2 and Comparative Example 1)
(1-1) Example 1 (papermaking fabric using yarn having a composite resin content of 15% by mass)
A polyethylene resin (molecular weight 70,000) was prepared as the high molecular weight resin, and an ultra high molecular weight polyethylene resin (molecular weight 2 million: manufactured by Mitsui Chemicals, Inc., product name “Miperon XM-220”) was prepared as the ultra high molecular weight resin. These are compounded so that the high molecular weight resin is 70% by mass and the ultra high molecular weight resin is 30% by mass when the total of the non-high molecular weight resin and the high molecular weight resin is 100% by mass. A mixed powder for resin was obtained.

  Further, 1 part by mass of maleic anhydride and 0.1 part by mass of benzoyl peroxide are added to the obtained composite powder for composite resin with respect to 100 parts by mass of composite powder for composite resin, and a biaxial kneader is used. The mixture was kneaded at a temperature of 220 ° C. to obtain an unsaturated carboxylic acid-modified composite resin pellet in which each resin was modified with maleic anhydride. Next, when nylon 6 resin (reactive matrix resin) is used as a base resin and the total of the melted nylon 6 resin and the composite resin is 100% by mass, the nylon 6 resin is 85% by mass and composite The resin is mixed so as to be 15% by mass, kneaded at a temperature of 280 ° C. using a twin-screw kneader, and then spun (including a drawing step) to produce an unsaturated carboxylic acid-modified composite having a wire diameter of 350 μm. A monofilament woven yarn for papermaking (Example 1) in which a resin (containing an ultra high molecular weight resin and a high molecular weight resin) was contained in a reactive matrix resin was produced.

  Polyethylene terephthalate having a wire diameter of 220 μm is used as the warp, polyethylene terephthalate having a wire diameter of 250 μm is used as the uppermost weft, and polyethylene terephthalate having a wire diameter of 350 μm is used as the lowermost weft and the above-mentioned textile yarn for papermaking (Example 1). A paper fabric of Example 1 having a double woven structure was produced using a quantity ratio of However, the number of warps was 100 / 2.54 cm, the number of uppermost wefts was 35 / 2.54 cm, and the number of lowermost wefts was 35 / 2.54 cm.

(1-2) Example 2 (papermaking fabric using yarn having a composite resin content of 5% by mass)
A monofilament papermaking yarn made of nylon containing a composite resin (Example), except that the amount of the unsaturated carboxylic acid-modified composite resin added is 5 parts by mass. 2) was produced.
Thereafter, a papermaking fabric (Example 2) was obtained in the same manner as in (1-1) above.

(1-3) Comparative Example 1 (papermaking fabric using yarn not containing composite resin)
Only the melted nylon 6 resin (not containing the composite resin) was spun (including the stretching step) to produce a monofilament papermaking yarn made of nylon having a wire diameter of 350 μm (Comparative Example 1). Next, in place of the papermaking fabric yarn of Example 1 in (1-1) above, the papermaking fabric (in the same manner as in (1-1) except that the papermaking fabric yarn of Comparative Example 1 was used) Comparative Example 1) was obtained.

[2] Comparative Test (1) Abrasion Resistance Test of Papermaking Textile Threads The papermaking textile yarns used in the production of each of the papermaking textiles of Examples 1-2 and Comparative Example 1 cut to a length of 65 cm were used as test pieces. The number of counts until cutting was measured with an abrasion tester. This abrasion tester includes a drum having abrasive paper (particle size 320) wound on its surface. Also, rotate the drum so that the center of the test piece is slid by the abrasive paper while fixing one end of the test piece and fixing the other end by applying a load of 350 g and sprinkling water of pH 7 to the test piece. It is something to be made. The drum was rotated at a rotation speed of 500 rpm, and the number of counts until the test piece was completely cut (1 count when the drum rotated once) was measured. The results are shown in Table 1.

(2) Abrasion resistance test of paper fabrics Tested in the same manner as in (1) above except that each of the paper fabrics of Examples 1-2 and Comparative Example 1 cut to a width of 2 cm and a length of 65 cm was used as a test piece. The number of counts until the piece was completely cut was measured. The results are also shown in Table 1.

(3) Dynamic Friction Coefficient of Paper Fabric Textile Measuring Device (Kato Tech Co., Ltd., “Friction Sense Tester KES-SE”) for measuring the dynamic friction coefficient of the lowermost layer of each paper fabric of Examples 1-2 and Comparative Example 1. It was measured by. The measurement environment was 20 ° C. and the humidity was 65%.
Further, in the measurement of the dynamic friction coefficient, it is considered that the composite resin is covered with the reactive base material resin in each of the papermaking fabric yarns immediately after spinning obtained in the above [1] (2). For this reason, each test piece has a measured value of “before polishing” with the surface in a woven state as the surface to be measured, and a measurement after “polishing” with the surface after polishing the same surface being 50 μm. Values were measured. The results are also shown in Table 1.

[3] Evaluation From the results in Table 1, the counts at the time of cutting in the abrasion resistance test of the papermaking fabric yarn were compared. As a result, the papermaking fabric yarn of Example 1 was 2.27 times the papermaking fabric yarn of Comparative Example 1. In addition, the papermaking fabric yarn of Example 2 was 1.49 times the papermaking fabric yarn of Comparative Example 2. Similarly, the count at the time of cutting in the abrasion resistance test of the papermaking fabric was compared. As a result, the papermaking fabric of Example 1 was 2.01 times the papermaking fabric of Comparative Example 1. Further, the papermaking fabric of Example 2 was 1.27 times the papermaking fabric of Comparative Example 2. That is, it can be seen that the wear resistance is improved by containing the composite resin.

  Furthermore, in the dynamic friction coefficient measurement, there is no significant difference between Example 1, Example 2 and Comparative Example 1 before polishing. In contrast, after polishing, it can be seen that the measured value of Example 1 is 0.039 smaller than that of Comparative Example 1, and the coefficient of dynamic friction is as small as 25%. Similarly, it can be seen that the measured value of Example 2 is 0.036 smaller than that of Comparative Example 1, and the dynamic friction coefficient is as small as 23%. That is, it can be seen that even when the papermaking fabric yarn containing the composite resin is only used for half of the lowermost layer wefts, a significant improvement in abrasion resistance is observed in the papermaking fabric.

  It should be noted that the present invention is not limited to those shown in the above specific embodiments, and can be variously modified and applied depending on the purpose and application. That is, for example, the material constituting the fabric, the warp and the weft, and the wire diameter can be changed according to the application. Further, the papermaking fabric yarn containing the composite resin may be applied to all the materials constituting the fabric, and only a predetermined amount. That is, it can also be configured to apply every predetermined number.

  The papermaking fabric of the present invention is widely used in the papermaking field. In particular, it is used as a forming wire for papermaking, a woven fabric, a knitted fabric, a felt fabric, a conveyor belt, a press felt for papermaking and a joining press felt, a dryer canvas for papermaking, and the like.

It is a schematic diagram of the longitudinal cross-section of this paper fabric. It is a schematic diagram in a cross section perpendicular | vertical to the longitudinal direction of an example of the textile yarn for papermaking used for this textile fabric for papermaking. It is a schematic diagram in the cross section perpendicular | vertical to the longitudinal direction of the other examples of the papermaking fabric yarn used for this papermaking fabric. It is a schematic diagram in the cross section perpendicular | vertical to the longitudinal direction of the further another example of the papermaking fabric thread | yarn used for this papermaking fabric. It is a schematic diagram in the cross section perpendicular | vertical to the longitudinal direction of the other example of the textile yarn for papermaking used for this textile fabric for papermaking.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Paper fabric, 21; Uppermost layer weft, 22; Bottom layer weft, 3; Warp, 4; Paper fabric yarn, 41; Base material resin, 42; Composite resin, 421; High molecular weight resin, 422; Molecular weight resin.

Claims (10)

A base resin having a viscosity average molecular weight of 500,000 or less;
A high molecular weight resin having a viscosity average molecular weight of 500,000 or less contained in the matrix resin;
An ultrahigh molecular weight resin having a viscosity average molecular weight of 1 million or more contained in the base material resin,
A papermaking fabric comprising at least a portion of a papermaking fabric yarn having a total content of the high molecular weight resin and the ultrahigh molecular weight resin of 30% by mass or less based on the entire yarn.   The papermaking fabric according to claim 1, wherein the base material resin is at least one of a polyamide-based resin and a polyester-based resin.   The papermaking fabric according to claim 1 or 2, wherein the high molecular weight resin is modified with an unsaturated carboxylic acid compound.   The papermaking fabric according to any one of claims 1 to 3, wherein the ultrahigh molecular weight resin is modified with an unsaturated carboxylic acid compound.   The unsaturated carboxylic acid compound is at least one of maleic anhydride, maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic anhydride and itaconic acid, and derivatives thereof. The papermaking fabric as described.   The papermaking fabric according to any one of claims 1 to 5, wherein the high molecular weight resin is a polyolefin.   The papermaking fabric according to any one of claims 1 to 6, wherein the ultrahigh molecular weight resin is a polyolefin.   The papermaking fabric according to any one of claims 1 to 7, wherein the papermaking fabric yarn is at least a part of a lowermost layer weft.   The papermaking fabric according to any one of claims 1 to 8, which is a papermaking forming wire.   The papermaking fabric according to any one of claims 1 to 9, wherein at least a part of the papermaking fabric yarn is coated with a thermosetting resin.

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