JPS60158876A - Ski sole - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION - The present invention relates to a ski sole that is glued to the underside of a ski to provide a sliding surface.

Materials used for ski running surfaces include high-density polyethylene (HD p BC) and ultra-high molecular weight high-density polyethylene ( UHpE,) is used. Among these, HDpE has good processability and is excellent in economy, but it is inferior in slipperiness and wear resistance, and is not necessarily a satisfactory material.

On the other hand, UHPE has extremely excellent properties in terms of slipperiness and abrasion resistance, making it the most suitable material for ski soles in that respect. It is difficult to form a sheet suitable for the
Process into 3mm sheets. Therefore, increases in sheet costs due to these processing costs and processing losses are unavoidable.
Furthermore, there are various problems such as warpage of the sheet due to processing strain, dimensional accuracy such as cutting marks, and dispersibility of various additives added to enhance the properties as a ski sole.

The present invention is advantageous in that silane-modified polyethylene can be processed in the same way as ordinary polyolefin, and has excellent slipperiness and abrasion resistance comparable to U and HPE due to water crosslinking after molding. Excellent sex,
Moreover, the present invention provides a ski sole that is homogeneous and has good dimensional stability.

That is, in the present invention, the density is 0.930~o, c+ a 5
g A sheet made of silane-modified polyethylene obtained by graft polymerizing 1 to 15% by weight of JO of an ethylenically unsaturated silane compound to 7 cm3 of polyethylene is water-crosslinked in the presence of a silanol condensation catalyst to give a gel fraction of 30 to 9.
This is a ski sole characterized by being bound at 0% by weight.

The polyethylene used in the present invention has a density of 0.940 to 0.95'5 g/'3, but it may be a copolymer of ethylene and α-olefin or a blend thereof. Mixtures can also be used.

Silane-modified polyethylene is obtained by graft polymerizing an ethylenically unsaturated silane compound to these polyethylenes in the presence of a radical generator.

The ethylenically unsaturated silane compound used has the general formula
R81 Y3-□ (where R is an ethylenically unsaturated hydrocarbon or oxyhydrocarbon group, zo is an aliphatic saturated hydrocarbon group, Y is a hydrolyzable organic group, and n is 0.1 or 2 ) is a silane compound represented by Specifically, R is vinyl, allyl, isopropenyl, butenyl, cyclohexenyl, γ-(meth)acryloyloxypropyl 2, etc., ν is methyl, ethyl, propyl, decyl, phenyl, and Y is methoxy, ethoxy, formyloxy. , acetoxy, propionyloxy, alkyl- to aryl-amino, and preferably a trialkylsilane in which R is vinyl or γ-(meth)acryloyloxypropyl.

As the radical generator, any compound that can generate free radical sites in the polyethylene under the graft reaction conditions and has a sufficiently short half-life at the graft reaction temperature can be used. These radical generators are described in Japanese Patent Publication No. 481,711, and representative radical generators include organic peroxides such as dicumyl peroxide, t-butylberoxyoctate, and benzoyl peroxide, and azoisoiso Examples include azo compounds such as butyronitrile and methyl azoisobutyrate.

In the grafting reaction of the ethylenically unsaturated silane compound to polyethylene, the silane compound is added in an amount of 0.01 to 15 parts by weight, preferably O
About 0.05 to 10 parts by weight and 0.05 to 10 parts by weight of the radical generator.
About 0.01 to 5 parts by weight, preferably about 0.01 to 2 parts by weight, are added and kneaded at a temperature at which the radical generator used is decomposed, generally about 150 to 200°C. Mixing can be carried out using a known method such as an extruder or a Banbury mixer.

Before being water-crosslinked, the silane-modified polyethylene is molded to a thickness suitable for ski soles. At this time, fillers such as carbon black, graphite, and phite, and lubricants such as silicone oil and fluorocarbon resin may be added for the purpose of improving the slipperiness and abrasion resistance of the product. Although these additives may be kneaded directly into the silane-modified polyethylene, good dispersion can be obtained by preferably blending them in the form of a masterbatch.

The silane-modified polyethylene formed into a sheet is
- water crosslinking in the presence of a condensation catalyst. The Silabaal condensation catalyst W used here is a compound used as a catalyst to promote dehydration condensation between silanols of silicone. Such silyl condensation catalysts generally include metal carboxylates such as tin, zinc, iron, lead, and cobalt;
Examples include organic bases, inorganic acids, and organic acids, such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, stannous acetate, stannous caprylate, lead naphthenate, and caprylic acid. Examples include carboxylic acid salts such as zinc and cobalt naphthenate, organic bases such as ethylamine, dibutylamine, hexylamine, and pyridine, inorganic acids such as sulfuric acid and hydrochloric acid, and organic acids such as toluenesulfonic acid, acetic acid, stearic acid, and maleic acid. be able to.

The amount of the silanol condensation catalyst used is approximately 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the silane-modified polyethylene of the present invention.

For example, the following method can be used to make the silanol condensation catalyst exist.

(1) A method of preparing a masterbatch containing a silanol condensation catalyst using a non-silane-modified composition, tri-blending it with silane-modified polyethylene before forming a sheet, and forming it into a sheet of a desired thickness as described above.

(2) A method in which a sheet containing no silanol catalyst is immersed in an aqueous solution or emulsion of a silanol catalyst.

In sheets into which silanol condensation catalysts have been introduced using these methods, water crosslinking will proceed due to moisture in the atmosphere even if the sheets are left in the atmosphere, but generally the sheets are kept at room temperature to 200℃.
It may be brought into contact with water (liquid or vapor) at a temperature of about 10°C, usually room temperature to 106°C, for about 10 seconds to about 1 week, usually about 1 minute to about 1 day.

In the present invention, it is preferable that the silane-modified polyethylene is crosslinked by the method described above to have a gel fraction of 40% or more, particularly preferably in the range of 50 to 75%. Figure 1 shows the relationship between the wear coefficient and gel fraction of organosilane-modified polyethylene after water crosslinking.For comparison, UHPK,
An example of measurement of wear coefficients for HD'PK and r, :opm is shown.

The resulting crosslinked sheet is adhered to a ski board as a ski sole. Adhesion may be done after water-crosslinking the silane-modified polyethylene sheet, but from the point of view of the shape memory properties of the crosslinked sheet, it is advisable to adhere it to the ski before water-crosslinking, and then soak it together with the ski in hot water or heat. It is advantageous to carry out the water crosslinking with water vapor. The ski to which the ski sole has been bonded is finished by removing the excess ski sole.

Various methods can be used to bond the ski sole of the present invention to the ski board. Generally, an epoxy adhesive is used, but any bonding method may be used as long as it provides sufficient bonding strength depending on the material of the ski. For example, a peroxide-based crosslinking agent solution is applied to the surface of an uncrosslinked or uncrosslinked ski sole sheet or the adhesive surface of a ski.
7. It is possible to press the two together and cure and bond them by heating.

Additionally, hot melt adhesives can also be used. Especially adhesive thermoplastics, such as polyethylene or ethylene.
Adhesive resins obtained by modifying vinyl acetate copolymer resins with unsaturated carboxylic acids such as maleic anhydride and acrylic acid or their derivatives, ethylene-acrylic acid copolymers, ionomers, etc. are used when forming the silane-modified polyolefin sheet of the present invention. It can be formed into a sheet having an adhesive resin layer by coextrusion, which further simplifies the process of adhering to skis and improves productivity.

The ski sole of the present invention has good workability, and a smooth sliding surface can be manufactured with high precision by extrusion molding or the like, and productivity is extremely high. In addition, fillers such as carbon and graphite and lubricants such as silicone oil and fluororesin can be easily incorporated into the silane-modified product before water crosslinking, and these additives can be well dispersed.

The ski sole of the present invention can be easily adhered to a ski board, and in particular, by coextrusion with an adhesive resin, a ski sole with an adhesive layer can be made all at once, which simplifies the adhesive application process. . The cross-linked product obtained by water cross-linking has shape memory properties, so ski soles that are bonded to skis before cross-linking and then water-cross-linked retain the shape memory properties that match the warp of the skis. There is no peeling force caused by strain caused by changes in humidity, etc., and changes in shape caused by external stress are easily restored by heating. On the other hand, the ski sole of the present invention has good sliding properties and abrasion resistance of Ul (PE).
This is the same as or better than that, and combined with excellent surface smoothness, it is possible to provide skis with an excellent sliding surface.

The various measurement methods used in the following examples are as follows.

(1) Gel fraction A crosslinked polyethylene sample is extracted using a Soxhlet type extractor using xylene as a solvent at boiling point humidity for 10 hours, and the weight of the extracted residue is expressed as a percentage according to the following formula.

(2) Taper wear amount It is expressed as the mass of the test piece detached from the wear test conducted under the following conditions in accordance with J Engineering S K'7204.

Wear wheel: H-22 Load: 1 kg Number of tests: 1000 times (3) Wear coefficient (as shown in Figure 1) Using a Toyo Seiki bearing friction tester, the surface pressure p, (9 on J2)
/ cJ) 'X circumferential speed V (32,7m/m1n)
=71,9 (kg/crl-m/min)
It is expressed as the amount of wear per unit load and unit traveling distance against the mating chrome-plated steel under the following conditions.

(4) Coefficient of friction The friction coefficient was measured in accordance with ASTM D1B94-73 using polyester (pET) as the mating material.

(5) Peel strength J-S based on IC685, 4, 2! 5 mm width,
T-peel strength was measured at a tensile speed of 50 mm/min.

Example 1 1.5% by weight of vinyltrimethoxysilane and 0.03% by weight of dicumyl peroxide were blended with HDPK having a density of c+ and 952, and grafted by kneading and extrusion at 120'c to obtain a silane-modified product. Ta. To 100 parts by weight of the obtained silane-modified product, 5 parts by weight of a masterbatch containing 1% ditoshinrutin silaurylate in HDPK was added, and a die molding machine was used using a full-flight screw with a diameter of 40 mm and L/D = 24. resin humidity 190-220' (
: Width 200 mm.

A sheet with a thickness of 10 mm was molded. This sheet has a width of 9
It was cut into 2 m long pieces and subjected to silane crosslinking treatment in a steam bath at 90°C for 10 hours. The gel fraction of the obtained crosslinked sheet was 65%.

The various performances of this sheet (sample A) were measured using UH of the same size.
PK (Sample B) and HD, pm (Sample C
). As shown in Table 1.

Dimensional stability (mm/mm) 1,5/2000 10/
2000 4/2000 taper wear amount (mg) 33
40 80 Coefficient of friction 0.180.21 0.41 Example 2 15 parts by weight of graphite and 5 parts by weight of dibutyltin silaurylate masterbatch were blended with 100 parts by weight of the silane modified product obtained in Example 1, and adhesive Using Modic 1300K (ethylene/vinyl acetate copolymer modified with 0.3% by weight of maleic anhydride) manufactured by Mitsubishi Yuka Co., Ltd. as a plastic resin, a 1 m silane modified layer was formed using a two-layer extrusion molding machine.
A sheet having a total thickness of 1.2 mm, consisting of 0.2 mm thick layer, 0.2 mm thick layer, and 0.2 mm thick layer was coextruded. This sheet was crosslinked in a steam bath at 60°C for 24 hours.

Sample D was prepared by hot-pressing the modic layer at 160° C. for 2 minutes at a pressure of 20 kg/C- to an aluminum ski whose surface had been roughened by sand-plasting. Sample A and TJHPE (sample B) of Example 1 were similarly heat-pressed and bonded to aluminum skis, and these were designated as sample A' and sample W, respectively. The adhesive strength of each sample was determined as T-peel strength (kg/25 mm) Sample D using coextruded sheet is 21k
g, whereas sample A' weighed 9 kg and sample B weighed 10 kg.

Example 6 The coextruded sheet of Example 2 was heat-pressed in the same manner without water-crosslinking, and the pressed product was water-crosslinked in the same manner as in Example 2.
The peel strength was 9 out of 40.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the gel fraction and the wear coefficient of the water-crosslinked product of the present invention. Patent applicant: Mitsubishi Yuka Co., Ltd. Agent: Katsura Atsuta, patent attorney

Claims (2)

[Claims] (1) A sheet made of silane-modified polyethylene obtained by graft-polymerizing 0.01 to 15% of an urban unsaturated 5-silane compound to polyethylene with a density of 0.930+-0,965 g/cm. A ski sole characterized in that it is water-crosslinked in the presence of a silanol condensation catalyst to have a gel fraction of 30 to 90% by weight. (2) The sheet made of silane-modified polyethylene is a composite sheet coextruded with an adhesive thermoplastic resin,
A ski sole according to claim (1).