JP2012030367A - Winding liner for unvulcanized rubber strip-shaped member and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a winding liner for an unvulcanized rubber strip-shaped member, which has sufficient releasability and durability, and to provide a suitable production method of the winding liner.SOLUTION: The winding liner 7 for the unvulcanized rubber strip-shaped member includes a layer of a silicone-modified thermoplastic polyurethane elastomer which is laminated on at least one surface of a strip-shaped base cloth to coat the cloth. The production method of the winding liner 7 for the unvulcanized rubber strip-shaped member comprises: laminating a silicone-modified thermoplastic polyurethane elastomer 6 on at least one surface of the strip-like base cloth 5 to coat the cloth at 160-250°C by use of a T-die extruder 2.

Description

  The present invention relates to a winding liner used when winding a belt-shaped unvulcanized rubber member and a method for manufacturing the winding liner.

In the tire manufacturing process, in order to store the unvulcanized rubber member, the belt-shaped unvulcanized rubber member supplied from an extruder or the like is wound and stored.
In this case, since the unvulcanized rubber member has adhesiveness, if it is wound as it is, the wound unvulcanized rubber member may adhere to each other, and the unvulcanized rubber member may be deformed during unwinding. . Therefore, a method is employed in which a winding liner is interposed between unvulcanized rubber members to prevent adhesion between the unvulcanized rubber members.

  The take-up liner used in this way is important for the peelability from the unvulcanized raw rubber member. Conventionally, as such a winding liner, a base fabric made of a synthetic fiber such as polyester has been mainly used. However, a synthetic fiber such as polyester is not necessarily sufficiently peelable from an unvulcanized rubber member. In order to improve the peelability, various ideas have been applied.

  For example, Patent Document 1 discloses a winding liner in which spacers that are taller than an unvulcanized rubber member placed in the length direction are provided on both sides of a non-extensible belt-like body. When this winding liner is interposed in the belt-shaped unvulcanized raw rubber member, the gap between the tall spacer provided in the winding liner and the belt-shaped unvulcanized raw rubber member causes the winding liner to The peelability from the unvulcanized raw rubber member can be kept good.

  On the other hand, in order to improve the releasability of the liner, Patent Document 2 discloses a winding liner in which an elastomer layer such as silicone rubber, nitrile rubber, or urethane rubber is formed on a base fabric made of synthetic fiber, or an elastomer layer. There is disclosed a winding liner provided with a surface layer made of silicone rubber or fluorine rubber which is further excellent in releasability.

  Among the above-mentioned winding liners, the winding liner having a polyurethane elastomer layer on one or both sides of the base fabric and further coated with silicone rubber on the surface layer has moderate flexibility and easy peelability of the unvulcanized raw rubber member. It is widely used because it has

JP 2004-34671 A JP-A-1-297239

However, when the unvulcanized rubber member is wound up with the winding liner provided with tall spacers on both sides of the belt-shaped member disclosed in Patent Document 1, the height of the spacer is increased. Therefore, the winding outside diameter of the unvulcanized rubber member wound up and stored is increased, and the thickness of the unvulcanized rubber member is particularly thin. This is a problem when the number of windings is large.
In addition, since the winding liner requires particularly complicated processing, mass production is difficult and cost tends to increase.

Further, the winding liner disclosed in Patent Document 2 has a problem that the surface layer made of silicone rubber has poor durability.
That is, when the surface layer of the silicone rubber is thick, it may be keratinized and fall off, and this is mixed into the unvulcanized raw rubber member, resulting in a problem of deterioration in quality. In particular, it is necessary to eliminate as much as possible the contamination of foreign materials in raw unvulcanized raw rubber members used for automobile tires and the like for safety. On the other hand, if the thickness of the silicone rubber of the surface layer is made thin (usually about 3 to 5 μm) in order to avoid the silicone rubber peeling and mixing, the peeling of the surface layer due to repeated use disappears, and the width is 1 m and the length. There has been a problem that frequent replacement of the winding liner as long as 160 m occurs.

  Under such circumstances, an object of the present invention is to provide a winding liner for an unvulcanized rubber band member having sufficient peelability and durability, and a suitable method for producing the winding liner.

  As a result of intensive studies to solve the above problems, the present inventor has found that the following inventions meet the above object, and have reached the present invention.

That is, the present invention relates to the following inventions.
<1> A take-up liner for an unvulcanized rubber belt-like member having a layer in which a silicone-modified thermoplastic polyurethane elastomer is laminated and coated on at least one surface of a belt-like base fabric.
<2> The winding liner according to <1>, wherein the belt-like base fabric is made of polyester.
<3> The winding liner according to <1> or <2>, wherein the thickness (one side) of the laminate coat layer is 50 to 200 μm.
<4> A method for producing a take-up liner for an unvulcanized rubber band member, in which a silicone-modified thermoplastic polyurethane elastomer is laminated and coated on at least one surface of a band base fabric at 160 to 250 ° C. by a T-die extruder.
<5> The method for producing a winding liner according to <4>, wherein the silicone-modified thermoplastic polyurethane elastomer has a hardness (JIS A) of 65 to 95.
<6> The method for producing a winding liner according to <4> or <5>, wherein the belt-like base fabric is made of polyester.
<7> The method for producing a winding liner according to any one of <4> to <6>, wherein the thickness of the laminate coat layer is 50 to 200 μm.

  The take-up liner of the present invention has a layer in which a silicone-modified thermoplastic polyurethane elastomer is laminated and coated on a base fabric, and has a strong and flexible polyurethane, and a peelable silicone polymer has a bond. However, since it is dispersed, it has sufficient peelability and durability. Furthermore, according to the method for producing a winding liner of the present invention, since the silicone-modified thermoplastic polyurethane elastomer is laminated by a T-die extruder, the liner can be produced with high productivity. Moreover, since it is a manufacturing method which does not use a solvent (it is solvent-free), there is little environmental impact.

It is the schematic which shows the manufacturing flow of the winding liner of this invention.

Hereinafter, the present invention will be specifically described.
First, the present invention relates to a winding liner for an unvulcanized rubber band member having a layer in which a silicone-modified thermoplastic polyurethane elastomer is laminated and coated on at least one surface of a band base fabric.

Here, the take-up liner means that when the belt-like member is wound and stored in a roll shape, the front and back surfaces of the belt-like member adhere to each other so that the front and back surfaces of the belt-like member are not in direct contact with each other. It is a sheet that is superposed on the belt-like member so as not to be damaged.
The take-up liner of the present invention is used for winding a non-vulcanized rubber member such as a tire, for example, a belt-like member continuously formed of an unvulcanized rubber sheet having adhesive properties such as an inner liner and a coated cord. used. The width and length of the liner are appropriately determined depending on the apparatus, place, etc. used, but those having a width of 5 cm to 1 m and a length of 5 m to 200 m are usually used.

  In the present invention, as the belt-like base fabric, a fiber fabric such as nylon, polyester, vinylon, polypropylene or the like is used. Among them, a polyester base fabric is preferably used. The base fabric may be woven with carbon fibers for imparting an antistatic effect or aramid fibers for imparting strength. The width and length of the base fabric are appropriately selected according to the specifications of the liner as the final product. The thickness of the base fabric is usually 0.1 mm to 1 mm.

The silicone-modified thermoplastic polyurethane elastomer used in the present invention has a polyurethane segment and a silicone polymer segment as a molecular structure.
Examples of such elastomers include a method of copolymerizing diorganopolysiloxane having alcoholic hydroxyl groups bonded to both ends with a diisocyanate compound as a diol component, or grafting with a diorganopolysiloxane containing two alcoholic hydroxyl groups at one end. It can be produced by a method, a method of kneading and extruding a mixture of an organopolysiloxane whose end is blocked with an isocyanate group and a diisocyanate using a continuous extruder.

  The silicone-modified thermoplastic polyurethane elastomer is required to have excellent wear resistance from the performance as a winding liner, and is required to have an appropriate hardness. Therefore, the silicone-modified thermoplastic polyurethane elastomer used in the present invention has an abrasion resistance (JIS K-7311) of preferably 450 mg or less, more preferably 100 mg or less, and particularly preferably 80 mg or less. Further, the hardness (JIS A; JIS K-7311) is preferably 65 to 95, and particularly preferably 70 to 85.

  Moreover, since the silicone-modified thermoplastic polyurethane elastomer used in the present invention is laminated and coated directly on the base fabric by a T-die extruder, the melt viscosity is 5000 to 30000 poise, preferably 5000 to 30000 poise. .

  Specific examples of the silicone-modified thermoplastic polyurethane elastomer used in the present invention include Rezamin PS series (manufactured by Dainichi Seika Kogyo Co., Ltd.).

  Further, the silicone-modified thermoplastic polyurethane elastomer of the present invention may further be appropriately added with a material for preventing deterioration such as an antioxidant or an ultraviolet absorber, an antistatic material, or a pigment or dye for coloring.

The winding liner of the present invention has a layer in which the silicone-modified thermoplastic polyurethane elastomer is laminated and coated on at least one side (one side or both sides) of the belt-like base fabric.
Since the silicone-modified thermoplastic polyurethane elastomer layer is composed of a relatively strong and flexible polyurethane and a peelable silicone polymer, it has sufficient peelability and wear resistance. The thickness of the laminate coat layer is independently 50 μm to 200 μm, preferably 75 μm to 180 μm on one side.

Next, with reference to FIG. 1, a method for producing a wind-up liner for an unvulcanized rubber band member in which a silicone-modified thermoplastic polyurethane elastomer according to another embodiment of the present invention is laminated and coated on at least one surface of a band base fabric by a T-die extruder will be described. Briefly described.
A silicone-modified thermoplastic polyurethane elastomer is melt-kneaded in the extruder 1 and extruded from the T-die 2. The temperature of the T-die extruder is controlled at a resin temperature of 160 to 250 ° C, preferably 180 to 240 ° C. If the temperature is lower than 160 ° C., there is a possibility that a problem may occur in the extrusion performance due to insufficient melting of the resin. On the other hand, if it exceeds 250 ° C., the raw material silicone-modified thermoplastic polyurethane elastomer may be deteriorated or decomposed. In addition, the said weathering agent, a pigment, etc. can be suitably added to a silicone modified thermoplastic polyurethane elastomer in the range which does not impair the objective of this invention.
The extruded silicone-modified thermoplastic polyurethane elastomer 6 is laminated on a separately supplied belt-like base fabric 5 to form a sheet-like liner 7. When the silicone-modified thermoplastic polyurethane elastomer is coated on both sides, the liner 7 with the coated surface on the back side is set in place of the belt-like base fabric 5, and the lamination process is performed in the same manner as described above. The liner thus obtained finally becomes a product in a form wound in a roll.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.

Example 1
As a silicone-modified thermoplastic polyurethane elastomer, "Rezamin PS-62470" (manufactured by Dainichi Seika Kogyo Co., Ltd .: silicone content; 16%, hardness 69) is a T-die extruder (manufactured by Johoku Seisakusho Co., Ltd.) in which the cylinder temperature is set in advance. (Model number: 1432, cylinder diameter: 115 mm, screw length / diameter ratio (L / D): 29)), the elastomer was heated and melted in the extruder, and the resin temperature was set to 240 ° C. The sheet was extruded from the lip portion into a sheet shape with a T-die, and laminated to a separately supplied 1100 mm width and 600 μm thickness polyester sheet. Then, the laminated sheet of Example 1 was obtained by making it pinch and contact with the cooling surface of a cooling roll, and cooling to 15 degreeC. The thickness of the silicone-modified thermoplastic polyurethane elastomer layer in the obtained sheet was about 100 μm.

(Comparative Example 1)
Using the same equipment as in Example 1, a thermoplastic polyurethane resin was laminated in place of the silicone-modified thermoplastic polyurethane elastomer to obtain a laminate sheet of Comparative Example 1. The thickness of the thermoplastic polyurethane resin layer in the obtained sheet was about 90 μm.

(Comparative Example 2)
The surface of the laminate sheet of Comparative Example 1 was further coated with a silicone resin to obtain a laminate sheet of Comparative Example 2. The total thickness of the thermoplastic polyurethane resin layer and the silicone resin layer in the obtained sheet was about 100 μm, and the silicone resin layer was about 10 μm.

(Comparative Example 3)
Comparative example in which silicone rubber was formed on the polyester sheet by sufficiently applying the coating liquid obtained by adding a curing agent to liquid silicone to the polyester sheet used in Example 1 and then curing the liquid silicone. 3 sheets were obtained.

  The obtained sheets of Example 1 and Comparative Examples 1 to 3 were subjected to a peel test and an abrasion resistance test in order to evaluate the usefulness of the unvulcanized rubber strip member as a winding liner.

"Peel test"
About the sheet | seat of Example 1 and Comparative Examples 1-3, the peeling test with respect to unvulcanized isoprene rubber was done. As a test method, each laminate sheet was cut to prepare a sample of 100 mm × 100 mm, the sample was placed on an isoprene rubber sheet, left to stand for 4 days under a load of 20 kg, and then peeled off. The force required to measure was measured.
The results are shown in Table 1. The force (peeling force) required to peel from the isoprene rubber sheet the laminate sheet of Comparative Example 1 having a thermoplastic polyurethane resin not containing a silicone component as the surface layer is defined as 100, and the peeling force of the other sheets is Shown as a relative value.

  From Table 1, the laminate sheet of Example 1 having a silicone-modified thermoplastic polyurethane elastomer as a surface layer clearly has less peeling force than the laminate sheet of Comparative Example 1 having a thermoplastic polyurethane resin as a surface layer, and the silicone resin is the surface. It was almost the same as the laminate sheet of Comparative Example 2 as a layer and the sheet having a silicone rubber as a surface layer.

"Abrasion resistance test"
An abrasion resistance test was performed on the sheets of Example 1 and Comparative Example 3.

Abrasion test: Conforms to JIS-K7311. (Test conditions: Wear wheel H-22, 1000 rotation wear)

As a result of conducting an abrasion test on the laminate sheet of Example 1, the amount of abrasion was 433 mg, and it was visually confirmed that the laminate layer remained.
As a result of performing the above-mentioned peel test using the laminate sheet after the wear test, it was possible to maintain a peel force comparable to that before the wear test.
On the other hand, as a result of conducting an abrasion test on the sheet of Comparative Example 3, the silicone rubber layer on the surface was worn out and peeled off, and measurement was impossible. Moreover, the thermoplastic polyurethane resin layer which is a base layer was confirmed visually. As a result of performing the above-mentioned peel test using the laminate sheet after the wear test, the peel force was clearly increased as compared with that before the wear test.

  The take-up liner of the present invention has a layer in which a silicone-modified thermoplastic polyurethane elastomer is laminated on a base fabric, and a strong and flexible polyurethane and a peelable silicone polymer are bonded and dispersed. Therefore, it has sufficient peelability and durability. For this reason, it is expected to be used in a line for producing unvulcanized rubber such as automobile tires.

DESCRIPTION OF SYMBOLS 1 Extruder 2 T die 3 Press roll 4 Cooling roll 5 Base material 6 Silicone modified thermoplastic polyurethane elastomer 7 Winding liner

Claims (7)

  A winding liner for an unvulcanized rubber belt-shaped member, comprising a layer having a silicone-modified thermoplastic polyurethane elastomer laminated and coated on at least one surface of the belt-shaped base fabric.   The winding liner according to claim 1, wherein the belt-like base fabric is made of polyester.   The winding liner according to claim 1 or 2, wherein the thickness (one side) of the laminate coat layer is 50 to 200 µm.   A method for producing a wind-up liner for an unvulcanized rubber belt-shaped member, wherein a silicone-modified thermoplastic polyurethane elastomer is laminated on at least one surface of a belt-shaped base fabric by a T-die extruder at 160 to 250 ° C.   The method for producing a winding liner according to claim 4, wherein the silicone-modified thermoplastic polyurethane elastomer has a hardness (JIS A) of 65 to 95.   The method for manufacturing a winding liner according to claim 4 or 5, wherein the belt-like base fabric is made of polyester.   The method for producing a take-up liner according to any one of claims 4 to 6, wherein the thickness (one side) of the laminate coat layer is 50 to 200 µm.

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