JPS59106932A - Method of rapid bonding of solid substance - Google Patents

Abstract

PURPOSE:To rapidly promote curing after construction, by spreading powdery or granular solid substance on a base plate while adhering an isocyanate type binder thereto to spread and press the same in the presence of water. CONSTITUTION:A binder comprising a prepolymer having an isocyanate group at the terminal end of the molecule thereof, an org. polyisocyanate or a mixture thereof is sufficiently mixed with solid substance. Water is further added to the binder adhered solid substance to perform mixing and the resulting mixture is spreaded on a base plate or the binder adhered solid substance is spreaded on the base plate and, thereafter, water is sprinkled thereover. The mixing ratio of the solid substance and the binder is pref. 99/1-60/40 on a wt. basis and water is generally used in an extremely excessive amount with respect to the isocyanate group in the binder. In the next step, the spreaded solid substance on the base plate is spreaded under pressure by a press, for example, a roll held at a room temp. or heated to about 100 deg.C whereupon the bonded substance is completely cured for several min-3hr and the constructed surface thereof can be directly started for use.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rapidly bonding powdered, granular or mixed solids with a binder in order to obtain elastic or rigid bonds.

Prepolymers and organic polyisocyanates that have an isocyanate group at the end of the molecule react with moisture in the air and become resinous or rubbery. It reacts with the active sites on the surface of a wide range of organic and inorganic solid materials, and forms a strong bond.

1- Therefore, as an example of using this property as a binder, c. Rubber such as tires, cushions, seats, bumpers, crushed polymer molded products made of vinyl chloride, polyurethane, etc., wood chips, cork powder, rice husk, sand. , and other powdered or granular solids, and the resulting elastic or rigid composites are used as paving materials for flooring, tennis courts, stadiums, sidewalks, etc.

A method of adhering the powdered, granular, or mixed solid materials using these isocyanate-based binders involves mixing these solid materials with a binder and adhering the binder as uniformly as possible to the solid material. There is a so-called on-site construction method in which the paving material is spread and pressed onto the ridge or base, or a so-called preforming method in which the paving material is manufactured by placing it in a mold and press-forming it.

In this on-site construction method, it generally takes 12 hours or more for the deposit to harden and become usable, so the construction site must be closed for a certain period of time during construction.

This point is important for the management of sports facilities. Improvements were strongly requested as this was a serious problem.

The present inventors conducted various studies on a method for rapidly progressing the hardening of the construction ridge while maintaining a sufficient pot life of the incyanate binder, and as a result, the present invention was arrived at.

That is, the present invention is as follows.

A binder consisting of a prepolymer, an organic polyincyanate, or a mixture thereof having an incyanate group at the molecular end is attached to a powder or granular solid, spread on a substrate, spread under pressure, and cured in the presence of water. A method for rapidly bonding solid materials, characterized by applying pressure.

The purpose of the present invention can be achieved only by adding water to a powder, granule, or solid mixture thereof to which a binder is attached, and then applying pressure by pressing, for example, at room temperature or with a heated roll. If the adhesive is rolled out using a heated roll without being sprayed, the curing speed will be slow.

The water used in the present invention is generally used in large excess relative to the incyanate groups in the inder.

Water is added before or after the solid material to which the binder is attached is spread on the substrate.

A catalyst can also be added to the water if necessary.

The catalyst used in this case may be any common catalyst for urethane, such as triethylene diamine, bisdimethylaminoethyl ether, dibutyltin dilaurate, and silver octoate.

Further, when using the heating roll mentioned above, it is appropriate that the temperature be up to 110°C; if the temperature is higher than this, there is a risk that the binder will decompose.

When constructing urethane-based paving materials, a temperature of 15°C or higher is usually required, making construction difficult in winter. However, according to the method of the present invention, rapid curing can be performed even at a temperature of 10° C. or lower, for example, 5° C., so a major feature is that construction can be performed even in winter.

The organic polyisocyanates used in the binder of the present invention include 2.4-) lylene diisocyanate, 2.6-) lylene diisocyanate, and 80% of both incyanates.
20 or 65/35 weight ratio mixture, diphenylmethane diisocyanate, so-called liquid diphenylmethane diisocyanate liquefied by various conventionally known methods such as Japanese Patent Publication No. 38-4576, crude product of tolylene diisocyanate, polymethylene polyphenyl polyinsyanate (
(crude product of diphenylmethane diisocyanate) It is one or a mixture of two or more of conventionally known aliphatic isocyanates such as aromatic polyisocyanate, dicyclohexylmethane diinocyanate, and isophorone diisocyanate.

These polyisocyanates can also be used in the production of prepolymers having inocyanate groups at the molecular ends of the present invention.

Polyhydric alcohols, water, ethylene glycol, propylene glycol, glycerin, pentaerythritol, polyols used when producing polyurethane prepolymers by reacting with these polyisocyanates, such as polyacrycerin, trimethylolpropane, and pentaerythritol.
Polyesters such as polyether polyols, polytetramethylene ether glycols, polycaprolactone polyols, and polyethylene adipate obtained by addition polymerization of propylene oxide 5- or propylene oxide and ethylene oxide to polyhydric alcohols such as sorbitol and sucrose. These are polyols, polybutadiene polyols, esters of higher fatty acids containing hydroxyl groups such as castor oil, and polymer polyols obtained by grafting vinyl monomers onto polyether polyols or polyester polyols.

When producing a polyurethane prepolymer having an isocyanate group at the molecular end, the polyincyanate and polyol are mixed at a NC010H equivalent ratio of 1.5-10 and a reaction temperature of 60.
The reaction is carried out at -130°C by a known method. In the reaction, a known catalyst such as dibutyltin dilaurate may be used.

In addition, in order to extend the pot life until the binder is attached to a solid material, spread on a substrate, and rolled out, and to make the work easier, organic acid 2-ide is added to the binder at a concentration of 0.1-10%.
It can also be added in weight percent.

6- If the viscosity of this binder is too high, acetone,
Solvents such as methyl ethyl ketone, ethyl acetate, toluene, etc. can be added, and fillers, colorants, etc. can also be added as necessary.

The mixing ratio of solids and binder is 99/1 to 60/40
A weight ratio of 9515 to 75/25 is particularly recommended.

To apply the present invention, first, a predetermined amount of binder and solid material are thoroughly mixed. If water is added to the solid material to which the binder is attached, the mixture is mixed and spread on the substrate, or the solid material to which the binder is attached is spread on the substrate, for example, by using a mouth-roll.
The deposit is completely cured in several tens of minutes to three hours, and the applied surface can be used immediately. Therefore, according to the method of the present invention, paving work for an athletic facility can be carried out at night, and the paved surface can be used normally from the morning on the next day.

The degree of hardening of a pavement surface is determined by dropping a steel ball from a certain height in accordance with JIS K-6401, and measuring the ratio of the bounce distance to the falling distance (%). If this repulsion ratio reaches 20% or more, the paved surface can be used.

Example 1 An amount of 7 incyanate groups produced from glycol and
．． 2% by weight prepolymer. Mitsui Nisso Urethane Co., Ltd. product) and tire rubber chips having a particle size of 1 to 3 mm were mixed at a weight ratio of 1:4 using a stirrer, and the binder was uniformly adhered to the surface of the chips.

Water in an amount equivalent to 16 times the amount of isocyanate in the binder was added to this deposit, mixed well, and then smoothed onto a flat plate in a room at 30±1° C. and relative humidity of 70±10%.

Next, when this was rolled out using a roll at 30° C., the curing time was 1.5 hours. Further, the curing time was 0.5 hours when the film was rolled out using a heated roll at 100°C. 100℃
The physical properties after curing are 100% modulus 13 kf/am" when rolled with a roll of
Tensile strength 14 kW/crr? , elongation was 130%, and tear strength was 11 kW/cm.

Example 2 The mixture of deposits and water obtained in Example 1 was leveled on a flat plate in a room at 5±1° C. and relative humidity 70±10%.

Next, when this is rolled out with a roll at 5℃, the curing time is 3
It was time. Physical properties after curing are 100% modulus 10
kf/cm'', tensile strength 10 kf/cm-elongation 100%, and tear strength 8 kW/cm.

Comparative Example 1 In Example 1, rolling pressure was applied using a roll heated to 100° C. without adding water, and the curing time was measured and found to be 7 hours. As a result of measuring the physical properties of this paved surface, the tensile strength was 5 kf/cm" and the tear strength was 5 kf/cm", indicating that the strength was insufficient.

Example 3 The same binder and polyurethane elastomer chips as in Example 1 were mixed at a weight ratio of 1:4 using a stirrer for 9 cycles to uniformly adhere the binder to the surface of the chips. This mixture was heated at 23±1℃ and relative humidity 70±10%.
The mixture was leveled to a thickness of 15 mm on a flat plate in a room, and 7.7 equivalents of water was sprinkled thereon. Thereafter, it was rolled out using a roll heated to 100° C., and the curing time was measured to be 3 hours.

Physical properties after curing are 100% modulus 13 kf/cm”
, tensile strength of 19 kf/cm", elongation of 180%, and tear strength of 16 kW/cm.

Claims (1)

[Claims] A binder made of a prepolymer, an organic polyisocyanate, or a mixture thereof having an incyanate group at the molecular end is attached to a powder or granular solid, spread on a substrate, spread under pressure, and cured in the presence of water. A method for rapidly bonding solid materials, characterized by applying pressure.