JP2009155761A - Reinforcing fiber cord for pneumatic cushion, and pneumatic cushion reinforced with the cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing fiber cord for pneumatic cushion, having high durability in particular, and to provide a pneumatic cushion reinforced with the cords. <P>SOLUTION: The reinforcing fiber cord for pneumatic cushion is such as to be composed of bulk-textured multifilament yarns comprising fibers where 95 mol% or greater of the recurring units consist of polyketone units each represented by formula (1):-CH<SB>2</SB>-CH<SB>2</SB>-CO-; wherein the bulk-textured multifilament yarns are fluid-jet-textured yarns. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a reinforcing fiber cord for an air spring and an air spring reinforced with the cord, and particularly relates to a reinforcing fiber cord for an air spring excellent in durability and an air spring reinforced with the cord.

  The applicant of the present invention previously described in Patent Document 1 that a stretchable composite yarn using a crimped yarn of a fiber composed of polyketone (hereinafter referred to as “polyketone fiber”) is suitable for a toothed belt. However, no particular consideration has been given to improving the durability of the air spring.

JP 2004-250825 A

  An object of the present invention is to provide a reinforcing fiber cord for an air spring, which is particularly excellent in durability, and an air spring reinforced with the cord.

（２）嵩高加工糸の表層部にループ毛羽が形成されていることを特徴とする上記（１）記載の空気バネ用補強繊維コード。
（３）毛羽長０．６ｍｍ以上のループ毛羽の個数が５〜１００個／ｍであることを特徴とする上記（１）又は（２）に記載の空気バネ用補強繊維コード。
（４）上記（１）〜（３）いずれかに記載の空気バネ用補強繊維コードで補強されたことを特徴とする空気バネ。 The inventors of the present invention have reached the present invention as a result of intensive studies to solve the above problems.
That is, the present invention is as follows.
(1) 95 mol% or more of the repeating unit is a reinforcing fiber cord for an air spring composed of a bulky processed yarn of a multifilament yarn of a fiber composed of a polyketone represented by the following formula (1), A reinforcing fiber cord for an air spring, wherein the processed yarn is a fluid injection processed yarn.

(2) The reinforcing fiber cord for an air spring according to the above (1), wherein a loop fluff is formed on a surface layer portion of the bulky processed yarn.
(3) The reinforcing fiber cord for air spring according to (1) or (2) above, wherein the number of loop fluff having a fluff length of 0.6 mm or more is 5 to 100 / m.
(4) An air spring reinforced with the air spring reinforcing fiber cord according to any one of (1) to (3).

  According to the present invention, there are provided a reinforcing fiber cord for an air spring and an air spring reinforced with the cord, which are particularly excellent in durability.

The present invention will be specifically described below.
In the present invention, the air spring includes a bellows shape, a diaphragm shape, and a composite shape, such as an air suspension for a railway vehicle, various industrial devices, automobiles (passenger cars, trucks, buses, etc.), for example, an automobile suspension, a truck It is used for cabin suspensions, seat suspensions, and the like.
As a specific example of the air spring, for a truck, an air chamber is defined by an upper surface plate and a lower surface plate, and a rubber film (rubber bellows) having an upper end and a lower end fixed thereto, respectively. Air is injected from an air intake hole provided in the central portion and set to a predetermined pressure. An example is one in which the internal pressure of the air chamber is increased by raising the piston and acts as an air spring.

Further, there may be mentioned one in which both ends of a cylindrical rubber film are attached between the upper blade and the piston, and an air chamber for supplying and discharging air is provided between these three members. As the cylindrical rubber film, a bellows-like bellows is used, an air supply / discharge hole is formed in a part of the upper blade, and a stopper rubber is provided on the piston side. This stopper rubber supports the load suddenly when the air spring is punctured, and if it is a vehicle, it can run until the air spring is replaced, and the deflection of the air spring is increased as an auxiliary spring for the air spring. Sometimes it functions as a spring while supporting the load.
The reinforcing fiber cord for an air spring of the present invention is used to reinforce a rubber film that constitutes an air chamber of the air spring, and an air spring in which an air chamber is constituted by a rubber film reinforced by the cord. Is to provide.

但し、Ｒは、エチレン以外の炭素数１〜３０の有機基であり、例えば、プロピレン、ブチレン、１−フェニルエチレン等の基であり、Ｒの水素原子の一部または全部が、ハロゲン基、エステル基、アミド基、水酸基、エーテル基で置換されていてもよい。もちろん、Ｒは二種以上であってもよく、例えば、プロピレン基と１−フェニルエチレン基が混在していてもよい。 In the polyketone constituting the polyketone fiber of the present invention, 95 mol% or more, preferably 98 mol% or more, particularly preferably 99.6 mol% or more of the repeating unit is represented by the above formula (1). The polyketone may contain a repeating unit other than the above formula (1), for example, one represented by the following formula (2) within a range of less than 5 mol%.

Where R is an organic group having 1 to 30 carbon atoms other than ethylene, for example, a group such as propylene, butylene, 1-phenylethylene, etc., and a part or all of the hydrogen atoms of R are halogen groups, esters It may be substituted with a group, an amide group, a hydroxyl group or an ether group. Of course, R may be two or more, for example, a propylene group and a 1-phenylethylene group may be mixed.

式中のｔ及びＴは、それぞれヘキサフルオロイソプロパノール（セントラル硝子（株）社製）及び該ヘキサフルオロイソプロパノールに溶解したポリケトンの希釈溶液の２５℃での粘度管の流過時間である。Ｃは、上記希釈溶液の濃度であり、ヘキサフルオロイソプロパノール１００ｍｌ中のポリケトンの質量（ｇ）である。 The intrinsic viscosity [η] of the polyketone is preferably 1 dl / g or more, more preferably 2 dl / g or more, particularly preferably 4 dl / g or more, preferably 20 dl / g or less, more preferably 15 dl / g or less, particularly Preferably it is 10 dl / g or less.
The intrinsic viscosity [η] is a value obtained based on the following definition formula.

In the formula, t and T are the flow times of the viscosity tube at 25 ° C. of hexafluoroisopropanol (manufactured by Central Glass Co., Ltd.) and a dilute solution of polyketone dissolved in the hexafluoroisopropanol, respectively. C is the concentration of the diluted solution, and is the mass (g) of polyketone in 100 ml of hexafluoroisopropanol.

The polyketone may contain additives such as antioxidants, radical inhibitors, other polymers, matting agents, ultraviolet absorbers, flame retardants, and metal soaps as necessary.
The shape of the polyketone fiber may be uniform or thick in the length direction, and the cross-sectional shape of the fiber may be round, triangular, L-shaped, T-shaped, Y-shaped, W-shaped, Yaba-shaped, flat (It has a flatness of about 1.3 to 4, including W type, I type, Boomerang type, wave type, skewer type, eyebrows type, rectangular parallelepiped type),
It may be a polygonal type such as a dogbone type, a multi-leaf type, a hollow type or an irregular type.

Next, as preferable characteristics of the polyketone fiber, the tensile strength is 5 cN / dtex or more, more preferably 10 cN / dtex or more, particularly preferably 15 cN / dtex or more, 30 cN / dtex or less, and the tensile elongation is 3%. Or more, more preferably 3.5% or more, particularly preferably 4% or more, 15% or less, more preferably 10% or less, still more preferably 8% or less, and particularly preferably 6% or less. Is 100 cN / dtex or more, more preferably 200 cN / dtex or more, particularly preferably 300 cN / dtex or more, and 1000 cN / dtex or less.
The yarn form of the polyketone fiber is a multifilament yarn, and the preferable single yarn fineness is preferably in the range of 0.01 to 10 dtex, more preferably 0.1 to 3 dtex, and particularly preferably 0.5 to 3 dtex. The total fineness is in the range of 10 to 3000 dtex, more preferably 30 to 2500 dtex.

The present invention is a reinforcing fiber cord for air spring using a bulky processed yarn of such polyketone fiber multifilament yarn, and this bulky processed yarn is a fluid jetting yarn.
In the present invention, it is preferable that loop fluff is formed on the surface layer portion of the fluid jetting yarn. In particular, the number of loop fluffs having a fluff length of 0.6 mm or more is 5-100. It is preferable that the number is per piece / m, and more preferably in the range of 10-80 pieces / m.
Further, the number of the loop fluffs having a fluff length of 0.35 mm or more is preferably 10 to 1500 / m, particularly preferably 50 to 1300 / m.

  In the present invention, the method for producing the fluid jet yarn is not particularly limited. For example, the polyketone fiber multifilament yarn is oversupplied to a fluid jet nozzle installed between two pairs of nip rollers, and the air is used. By spraying fluid at high speed and ejecting polyketone fiber multifilament yarns to the outside of the nozzle and at the same time rapidly decelerating, it can be produced by a method in which filaments are entangled while forming loop-like fluff. If necessary, two or more of the same or different types of fluid ejection nozzles may be arranged in series, and the fluid ejection processing may be performed twice or more. At that time, the fluid injection processing conditions may be the same or different.

As a typical method for producing the fluid jetting yarn, there are a 1-feed method and a 2-feed method.
In the case of the 1-feed method, a fluid jetting yarn composed of 100% of a polyketone fiber multifilament yarn is obtained.
In the case of the two-feed method, two multifilament yarns are supplied and fluid ejection processing is performed. At least one multifilament yarn may be a polyketone fiber, and the other is a polyketone fiber or a fiber other than a polyketone fiber ( And fibers mixed with the fluid jetting yarn of the present invention described in detail below.

  Whether or not to make a difference between the feed rates of the two multifilament yarns may be appropriately selected according to the required yarn structure of the fluid jetting yarn. If there is no difference in feed rate, the resulting fluid jet yarn will have a structure in which two multifilament yarns are mixed together. The greater the difference in feed rate, the clearer the core structure will be. If necessary, the polyketone fiber multifilament yarn may be disposed in the sheath portion and / or the core portion. At that time, the single fineness and the total fineness of the fibers used may be changed, for example, the single fineness of the fibers arranged in the core may be increased.

As other fluid injection processing conditions, the processing speed is preferably in the range of 50 to 500 m / min, and more preferably in the range of 100 to 400 m / min. The fluid jet pressure is preferably 250 kPa to 1 MPa as a gauge pressure, and particularly preferably 400 kPa to 1 MPa. Furthermore, it is preferable to supply and impart an appropriate amount of water to the fibers during fluid jet processing, since the entanglement between the multifilaments can be made stronger and more uniform. The feed rate is + 1% to + 30% for simultaneous feed, the core yarn is + 1% to + 20%, the sheath yarn is +3 to + 40%, and the feed rate difference is +1 to + 1% to + 30% + 30% is preferable. Furthermore, heat setting may be performed after the fluid jet processing, and the heat setting temperature is preferably 130 to 210 ° C., particularly preferably 150 to 190 ° C. as the heater temperature of the tube heater, and the heat setting time is 0.1. It is preferably -0.5 seconds, particularly preferably in the range of 0.1-0.3 seconds.
Moreover, before supplying to fluid injection processing, you may heat-process a supply thread | yarn in the form of a thread | yarn of cheese or corn (dry heat or wet heat) beforehand as preferable heat processing conditions. 210 degreeC is preferable, More preferably, it is the range of 130-190 degreeC, Time is 0.5 to 3 hours, More preferably, it is the range of 1 to 2.5 hours.

  In the present invention, the fluid jetting yarn of the polyketone fiber multifilament yarn may occupy 50% by mass or more, and the fluid jetting yarn of 100% polyketone fiber multifilament yarn is optimal. If necessary, it may be mixed with fibers other than polyketone fibers, preferably in a range of less than 50% by mass, or may be combined with different thread forms of the same type of fibers. For example, multifilaments of fibers other than polyketone fibers Examples thereof include a fluid injection processed yarn obtained by fluid injection processing using a yarn and two feeds, a combination of a fluid injection processed yarn of polyketone fiber multifilament yarn and a multifilament yarn base yarn of polyketone fiber.

  Examples of fibers other than polyketone fibers include natural fibers such as cotton and wool, cellulose fibers such as rayon fibers and lyocell fibers, polyester fibers, polyamide fibers, aramid fibers (para and meta), polyvinyl alcohol fibers, and total aromas. Various types of known fibers such as polyester fiber, poly (p-phenylenebenzobisoxazole) fiber, ultra-high molecular weight polyolefin fiber, carbon fiber, ceramic fiber, glass fiber, metal fiber, etc. There are bulky processed yarns such as yarns, filaments of staple fibers and crimped yarns, which may be appropriately selected or used in combination as necessary. 3 thread etc.), mixed fibers, covering (single or double), fluid jet machining, etc., may be used for mixing.

In the present invention, such a fluid jetting yarn may be used after additional twisting if necessary, and the twisting coefficient (K) of the additional twist may be selected in the range of 1000 to 10,000. Moreover, it can be made into a double yarn or a triplet by a conventional method, for example, by a lower twist and then an upper twist.
Here, the twist coefficient (K) is a value obtained by the following formula.
Twisting coefficient (K) = number of additional twists × total fineness of fluid jetted yarn (dtex) ^1/2

The reinforcing fiber cord for air spring of the present invention is composed of such a fluid injection processed yarn of polyketone fiber multifilament yarn, but when used as a reinforcing fiber cord for air spring, it may be RFL-treated. .
RFL treatment refers to treatment with a mixed solution containing resorcin, formalin and latex, and the preferred adhesion amount of the RFL resin is in the range of 1 to 10 mass%, particularly preferably 2 to 7 mass% with respect to the fiber. is there.

The preferred molar ratio (F / R) of formalin (F) to resorcin (R) is 1.0 to 2.2, particularly preferably 1.0 to 1.9, and the solid content mass (L) of the total latex. The ratio (RF / L) of total resorcin and formalin (RF) to 5 to 25% by mass, particularly preferably 5 to 17% by mass, and the total amount of sodium hydroxide and ammonium hydroxide and resorcin (R) The molar ratio (NaOH + NH ₄ OH / R) is preferably 0.21 or less.

The latex is preferably a latex corresponding to the rubber composition constituting the rubber film of the air spring. Examples of the rubber composition include natural rubber (NR), styrene butadiene rubber (SBR), butadiene rubber (BR), Chlorosulfonated polyethylene (CSM), chloroprene rubber (CR), ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), butyl rubber (IIR), acrylic rubber (ACM, ANM), ethylene acrylic rubber (AEM), One or two or more blend rubbers such as hydrogenated acrylonitrile rubber (HNBR), acrylonitrile rubber (NBR), and urethane rubber (UR) are used, and latexes corresponding to these rubber compositions can be mentioned.
Prior to the RFL treatment, pretreatment with an epoxy or isocyanate compound may be performed.
As a method of RFL treatment, it may be applied to a fluid injection processed yarn of polyketone fiber multifilament yarn, or, if necessary, RFL treatment may be performed with the fluid injection processed yarn twisted.

The number of twists is preferably 100 to 700 in terms of the twist coefficient (K1), but may be medium to strong twist of about 30,000.
Here, the twist coefficient (K) is a value obtained by the following formula.
T1 = K1 / D ^1/2
T1 = Number of twists (T / m), D = Fine fineness (dtex) of the yarn supplied for RFL
Further, after forming a reinforcing fiber cord for air spring or a fiber cord fabric of air spring, RFL treatment may be performed.

The present invention uses such a fluid jetting yarn as a reinforcing fiber cord for an air spring, and the total fineness of the reinforcing fiber cord for an air spring is preferably 1500 to 5500 dtex for a truck, bus, and railway air spring. In the air spring for use, 300 to 1600 dtex is preferable, and a range of 400 to 1500 dtex is particularly preferable.
The reinforcing fiber cord and the reinforcing fiber cord layer are preferably composed of 100% of the reinforcing fiber cord for an air spring of the present invention. However, if necessary, other reinforcing fiber cords (described above) may be used within a range of less than 50% by mass. May be mixed by aligning, knitting, knitting, knitting, etc., for example, each reinforcing fiber cord to be mixed is twisted, There is a method of twisting these twisted yarns, and the ratio of the twisted number to the twisted number is preferably 0.5 to 1.5, particularly preferably 0.8 to 1.2. Further, in the warp and / or weft of the reinforcing fiber cord layer, one to several yarns may be mixed alternately, or one or two S twist yarns and Z twist yarns of the same reinforcing fiber cord or different reinforcing fiber cords may be alternately used. You may mix.

Usually, the rubber membrane constituting the air chamber of the air spring is a reinforcing fiber cord layer (fiber cord fabric) in which a number of reinforcing fiber cords are inclined with respect to the circumferential direction of the rubber membrane body and arranged in parallel to each other. The two reinforcing fiber cord layers are laminated, and the first and second sheets are arranged so that the reinforcing fiber cord directions are symmetrically inclined in the left-right direction.
Therefore, the reinforcing fiber cords for air springs of the present invention are arranged in parallel at a predetermined angle with respect to one direction. The number of reinforced fiber cords to be driven is preferably 40 to 80/5 cm for air springs for trucks, buses, and railways, and preferably 90 to 150/5 cm for air springs for passenger cars.

Examples of the rubber composition constituting the rubber film include those described above. In particular, for high-temperature vulcanization, ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), butyl rubber (IIR), acrylic rubber (ACM), ethylene acrylic rubber (AEM), hydrogenated acrylonitrile rubber (HNBR) and other heat resistant rubbers are preferred as the main component.
Such rubber compositions include vulcanizing agents (organic peroxides, resins, amines), accelerators (vulcanizing accelerators), reinforcing agents such as carbon and zinc oxide, aromatic oils as plasticizers, An anti-aging agent, a release agent, a dispersant, a curing agent, a tackiness modifier, a bulking agent, a colorant, and the like are added as necessary.

A rubber film can be produced by interposing the reinforcing fiber cord for an air spring of the present invention between unvulcanized rubbers made of such a rubber composition and performing vulcanization molding according to a conventional method.
The thickness of the rubber film is preferably 4 to 7 mm for truck and bus air springs, preferably 5 to 12 mm for railway air springs, and preferably 2 to 3 mm for passenger car air springs.
As a method for producing a rubber film, a braided woven fabric is usually produced using the reinforcing fiber cord for air spring of the present invention and used for warp. As the weft of the weave fabric, the reinforcing fiber cord for air spring of the present invention may be used. However, the fiber mixed with the fluid jetting thread of the present invention, such as nylon fiber, or about 50 to 200% as necessary. High elongation fibers or the like may be used.
The thickness of the reinforcing fiber cord is preferably about 0.5 to 1.2 mm for trucks, buses, and railway air springs, and preferably about 0.2 to 0.4 mm for passenger car air springs.

  Two sheets of the obtained woven fabric (usually RFL-treated woven fabric) are used, and each side is coated with adhesive rubber such as CR type and NR / SBR type. Laminate so that the warp direction is left-right symmetric so as to cross at the crossing angle, and further, cover rubber such as CR or NR / SBR is laminated on both sides of this laminated sheet and heat vulcanized under predetermined conditions To do. The thickness of the adhesive rubber is preferably about 0.25 to 0.35 mm for an air spring for trucks, buses, and railways, preferably about 0.2 to 0.25 mm for an air spring for passenger cars, and the thickness of the cover rubber is In the air spring for trucks, buses and railways, about 2 to 4 mm is preferable, and in the air spring for passenger cars, about 0.6 to 0.8 mm is preferable.

  For example, for the purpose of suppressing a decrease in the tensile strength of the polyketone fiber by receiving strong ultraviolet rays outdoors, for example, an ultraviolet absorbent (for example, benzophenone series, benzotriazole series, hindered amine) in the form of fiber or fluid injection processed yarn or fabric There are one type or a combination of two or more types) and / or ultraviolet screening agents (for example, fine particles of titanium oxide, iron oxide, cerium oxide, etc.), and the average particle size is preferably 0.01 to 0.6 μm. ) Is preferably contained. Examples of the method of inclusion include a method of imparting or coating a resin or a film containing an ultraviolet absorber and / or an ultraviolet shielding agent to a fiber or fluid jetting yarn or woven fabric, and the ultraviolet absorber and / or the ultraviolet shielding agent. The content of is preferably 0.001 to 10% by mass relative to the mass of the resin or film.

The present invention will be described more specifically based on examples, but the present invention is not limited to these examples.
The measurement method and evaluation method in the present invention are as follows.
(1) Tensile strength, tensile elongation, and tensile modulus of fiber Measured according to JIS-L-1013.
Sample length: 20 cm, tensile speed: measured at 20 cm / min, and an average value is obtained when measured 20 times.

(2) Number of loop fluff The number of loop fluff protruding from the yarn surface of the fluid jetting yarn by 0.35 mm or more and 0.6 mm or more was measured using a photoelectric fluff measuring machine (TORAY FRAY COUNTER), and the yarn speed was 10 m / Measured under the conditions of minute and running yarn tension of 0.1 g / d.
(3) Rubber film durability test (for trucks, buses, railways)
It measured based on JIS-D-4101 (rubber bellows test method for air springs).
<Measurement conditions>
Internal pressure (MPa); 0.7
Stroke (mm); ± 80
Speed (rpm); 60
Temperature: normal temperature

(4) Production of rubber films for trucks, buses, and air springs for railroads Combined two fluid jetting yarns obtained in the examples were subjected to 40 twists / 10 cm in the Z direction, and then Three of the obtained lower twisted yarns are combined and subjected to 40 times / 10 cm of upper twist in the S direction to obtain a reinforcing fiber cord. After this reinforcing fiber cord is treated with RFL, it is used as a warp yarn for a weave fabric (55 yarns per 5 cm), and 300 dtex nylon 6 fiber is used as a weft yarn (4 yarns per 5 cm) to produce a weave fabric. .
Using two sheets of the interwoven fabric obtained, both sides are coated with NR / SBR adhesive rubber of 0.3 mm each, and the warp direction of the interwoven fabric is crossed at a predetermined crossing angle so that the warp direction of the interwoven fabric is crossed at a predetermined crossing angle. Laminate symmetrically, and then laminate 2.5 mm NR / SBR cover rubber on both sides of this laminated sheet and vulcanize for 20 minutes at 155 ° C. and 1.5 MPa to form a rubber film. Make it.

[Example 1]
280 dtex / 208f polyketone fiber multifilament yarn (manufactured by Asahi Kasei Fibers Co., Ltd .; trademark Cyvalon; tensile strength 18 cN / dtex, tensile elongation 5%, tensile elastic modulus 350 cN / dtex) 335-II was used to produce a fluid jetting yarn. Specific manufacturing conditions are as follows.
Air nozzle: Hemajet T-321K manufactured by Heberlein
Processing speed: 100 m / min Air pressure: 588 kPa (6.0 kg / cm ² )
Feed rate: + 8%
Water grant: Yes (200cc / min)
The number of the fluffs of the obtained fluid jetting yarn was 100 / m for 0.35 mm or more and 50 / m for 0.6 mm or more.
A reinforcing fiber cord was obtained using the obtained fluid-jet processed yarn, and the result of the durability test of the rubber film using the reinforcing fiber cord was excellent at 2 million times or more.

[Comparative Example 1]
A polyketone fiber multifilament yarn similar to that in Example 1 was false twisted under the following conditions to obtain a 1 heater false twist yarn.
<False twist processing conditions>
False twisting machine; LS-2 (Mitsubishi Heavy Industries, Ltd .; Pin false twisting machine)
False twist number T1; 1500 T / m (false twist coefficient K1; 25100)
False twisting temperature: 220 ° C
Feed rate: + 1%
False twisting speed: 100 m / min Using this false twisted yarn, a reinforcing fiber cord was obtained in the same manner as in Example 1. The result of the durability test of the rubber film using the reinforcing fiber cord was 1.2 million times. It was inferior to 1.

  The present invention provides a reinforcing fiber cord for an air spring, which is particularly excellent in durability, and an air spring reinforced with the cord.

Claims (4)

A reinforcing fiber cord for air spring composed of a bulky processed yarn of a multifilament yarn made of a polyketone composed of polyketone represented by the following formula (1) in which 95% by mole or more of the repeating unit is a fluid. A reinforcing fiber cord for an air spring, characterized by being an injection-processed yarn.

  The reinforcing fiber cord for an air spring according to claim 1, wherein loop fluff is formed on a surface layer portion of the bulky processed yarn.   The reinforcing fiber cord for an air spring according to claim 1 or 2, wherein the number of loop fluff having a fluff length of 0.6 mm or more is 5 to 100 / m.   An air spring reinforced with the reinforcing fiber cord for an air spring according to any one of claims 1 to 3.