JPH0387402A - Elastic paving material - Google Patents

Abstract

PURPOSE:To obtain elastic paving material which has large tensile strength, elongation percentage, and tear strength by mixing rubber particles, inorganic minute fibers, and polyor, and adding urethane prepolymer with isocyanate as terminal residue in liquid to harden it. CONSTITUTION:Particulate matter is obtained by mixing 100 weight parts of rubber particles having average particle diameter of 10mm or less, 1 to 20 weight parts of inorganic minute fibers having average diameter of 10mum or less and average aspect ratio of 20 to 100, and 0 to 10 weight parts of polyor having average molecular weight of 500 to 10,000 at a specific ratio. Next, 10 to 45 weight parts of urethane prepolymer with isocyanate as terminal residue in liquid are added to the particulate matter at a specific ratio. Pressure is applied to concrete or asphalt. The particulate matter is spread in sheet, and hardened at room temperature.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is applicable to tennis courts, multiple routes of golf courses, promenades,
This article relates to all-weather elastic paving materials used in athletics stadiums, etc.

[Prior Art] When a liquid isocyanate-terminated urethane prepolymer is added to rubber particles and cured to obtain an elastic paving material, the rubber particles are kneaded with an inorganic filler such as cement or potassium bicarbonate and a polyether polyol. is published in Japanese Unexamined Patent Application Publication No. 1983-
It is described in Publication No. 41501. In addition, polypropylene resin, polybutylene terephthalate resin, and phenol resin have an average diameter of 2 to 6 μm and an average aspect ratio of 40.
It is reported in Industrial Materials Vol. 29, No. 5, that mechanical properties such as tensile strength of resins are improved by adding ~60 inorganic fine short fibers.
0-54 (1981).

However, even if an inorganic filler such as cement and polyether polyol are kneaded, if the amount of liquid isocyanate-terminated urethane prepolymer used is large relative to the rubber particles, the resulting elastic paving material may foam. For this reason, the tensile IJI strength, elongation rate and tear strength are
It cannot be said that it is always sufficient.

[Problem to be solved by the invention]

In order to obtain an elastic paving material with excellent mechanical properties, the inventors of the present invention have conducted intensive studies and found that a mixture of granules obtained by kneading rubber particles and specific inorganic fine short fibers with a small amount of liquid. The present invention has been completed based on the discovery that an elastic paving material obtained from an isocyanate-terminated urethane prepolymer does not foam, has satisfactory mechanical properties, and can withstand long-term use.

[Means to solve problems]

The present invention uses 100 parts by weight of rubber particles with an average particle diameter of 10 μm or less and an average aspect ratio of 20-10 μm or less.
0 inorganic fine short fibers 1 to 20 parts by weight and number average molecular weight 50
A liquid isocyanate-terminated urethane prepolymer (hereinafter referred to as prepolymer) 10 to 45 w1 is added to the granules obtained by kneading 0 to 10 parts by weight of a polyol of 0 to 10,000.
It provides an elastic paving material obtained by adding a certain amount of the compound and curing it.

Rubber particles can be synthesized from natural rubber, styrene/butadiene rubber, acrylonitrile/butadiene rubber, vinylpyridine/butadiene rubber, polybutadiene rubber, polyisoprene rubber, polychloroprene rubber, styrene/isoprene rubber, butyl rubber, ethylene/propylene rubber, polyurethane rubber, etc. It is made by pulverizing rubber or vulcanized products of these rubbers, and may also be made by pulverizing waste tires and the like. The average particle size is 10 mm or less, preferably 1 to 3 mm.

The inorganic fine short fibers are mineral fibers or glass fibers containing silica, aluminum oxide, calcium oxide, magnesium oxide, etc., and have an average diameter of 10 μm or less and an average aspect ratio of 20 to 100. The amount added is 1 to 20 parts by weight, preferably 3 to 8 parts by weight, per 100 parts by weight of the rubber particles.

Polyols include long-chain active hydrogen-containing compounds with a molecular weight of 1000 or more, such as polyether polyols, polyester polyols, polycarbonate polyols, and polymer polyols, and short-chain active hydrogen-containing compounds with a molecular weight of 100 or less, such as diglobylene glycol and butanediol. It is a mixture of , and its number average molecular weight is 500~
It is 1oooo. The amount added is 10 parts by weight or less, preferably 1 to 5 parts by weight, per 100 parts by weight of the rubber particles. Also, it may not be added at all.

The prepolymer is liquid at room temperature obtained by reacting polyol and excess polyisocyanate under normal conditions, for example at 80°C for 3 hours, and has a terminal isocyanate content of 1 to 20% by weight, preferably teeth,
It is 5 to 15% by weight. The amount added is 100 rubber particles.
10 to 45 f [total parts, 20 to 30 parts by weight]
Parts by weight are preferred.

Polyisocyanates include toluene diisocyanate, polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate (hereinafter referred to as MDI), urethane-modified isocyanates and carbodiimide-modified isocyanates made by reacting these isocyanates with long-chain active hydrogen-containing compounds or short-chain active hydrogen-containing compounds. The terminal isocyanate content of the isocyanate is more than 20% by weight, and MDI and urethane-modified MDI are preferable.

Granular materials are usually obtained by kneading rubber particles, inorganic short fibers, and polyol in a mulch machine at room temperature, and other auxiliary agents such as colorants, urethanization catalysts, antioxidants, etc. may also be added. can.

A prepolymer is usually added to the granules using a cement mixer at room temperature, and the mixture is compressed into a sheet on top of concrete or asphalt, etc., and is usually cured at room temperature to obtain an elastic paving material. . To speed up the curing speed, use tools such as heated rollers and presser plates.

[Example] The average particle size obtained by crushing waste tires in an Ishikawa-type pickling machine was
ms+ rubber particles, inorganic short fibers, and polyol,
The parts by weight shown in Table 1 were added while kneading to obtain granules. The prepolymer in the weight parts shown in Table 1 was added to the granules and mixed uniformly with a cement mixer to obtain a mixture. This mixture was poured into a mold and allowed to stand at room temperature for one day to harden to obtain a non-foamed elastic paving material. The density, tensile strength, elongation rate, and tear strength of the obtained elastic pavement materials were examined. The results are shown in Table 1.

As a comparative example, an unfoamed elastic paving material was obtained in the same manner as in the example except that no inorganic fine short fibers were used or cement was used instead of non-11 fine short fibers, and the density and The tensile strength, elongation rate and tear strength were examined. The results are shown in Table 1.

[Effects of the Invention] The elastic pavement material of the present invention does not foam and has high tensile strength, elongation rate, and tear strength.

Therefore, it can be widely used as an all-weather elastic paving material for tennis courts, multi-course golf courses, promenades, track and field stadiums, etc. that can withstand long-term use.

that's all

Claims (1)

[Claims] 1. 100 parts by weight of rubber particles with an average particle diameter of 10 mm or less, 1 to 20 parts by weight of inorganic short fibers with an average diameter of 10 μm or less and an average aspect ratio of 20 to 100, and a number average molecular weight of 500 to 500.
Elastic paving material obtained by adding 10 to 45 parts by weight of liquid isocyanate-terminated urethane prepolymer to granules obtained by kneading 0 to 10 parts by weight of polyol 10,000 and curing the mixture.