RU2329277C1 - Method of solidifying single-component foamed polyurethanes for prolonged storage - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention pertains to the method of speeding up solidification of single-component foamed polyurethanes for prolonged storage, used when extruding onto a surface. The proposed method involves putting ethyleneglycol into a container containing foamed polyurethane ready for use, in ratio of 35-50 ml for 750-1000 ml of the foamed polyurethane in the container. The mixture is stirred for several times and then sprayed on to a prepared surface.

EFFECT: given method provides for speeding up solidification of single-component foamed polyurethanes, foamed polyurethanes, solidified using the proposed method, are used on adhesive surfaces.

2 cl, 1 ex

Description

The invention relates to methods for curing synthetic polyurethane foams of quick hardening, used for filling joints, voids, gluing, fixing various materials during the installation of window and door frames, repairing bathtubs and other bulky products made of metal, porcelain, plastic, etc.

A known method of curing one-component polyurethane foams with long-term storage, in which hardening is carried out by extrusion on the surface intended for its application and in which the components are a mixture of polyester or polyether diol with dimethanylmethanediisocyanine (See, for example, RF patent No. 2229482, IPC 7 C08G 18/10 "Flexible porous material, composition and method of its production", publ. 27.05.04, BI No. 15).

The disadvantage of this method is that the curing of the foam occurs with the access of air and moisture, which is not always possible under the conditions of using the foam as an adhesive material. In addition, curing of the foam occurs quickly and therefore, for example, it is impossible to use the product by direct extrusion for repairing bathtubs, since it takes some time, measured 15-20 minutes, to adhere acrylic liners.

There is also known a method of curing single-component polyurethane foams with long-term storage, in which hardening is carried out by extrusion onto a surface intended for its application and in which either polymethylene polyphenylene polyisocyanate or toluene diisocyanate, or a complex of polyether diol ethylene or ethylene glycol glycol, or ethylene glycol mixtures thereof with dibasic acids, phthalic, adipic or mixtures thereof. (See, for example, RF patent No. 2021294, IPC 5 C08G 18/16, publ. 15.10.94, in BI No. 19).

The proposed method allows you to slightly increase (up to 8 min) the curing time of the material.

The closest and adopted as a prototype is a method for producing a molded polyurethane foam, the main part of which is a prepolymer with terminal isocyanate groups, the content of NCO in which is from about 5 to 35 wt.% With terminal isocyanate groups, including the interaction of the isocyanate component, including the interaction of the isocyanate prepolymer with one or more isocyanate reactive component (s), while the isocyanate reactive component can be used and ethylene glycols. (See, for example, RF patent No. 21787890, IPC 7 C08G 18/10, "Molded polyurethane foam with improved physical properties" publ. 27.05.01, in BI No. 15).

However, as in the previously described methods, the curing of the foam occurs too quickly. In addition, air thickening and moisture are necessary for thickening the foam, and the volume of hardened material increases by 15-20%, which is unacceptable in some installation works.

Currently, one-component long-term storage polyurethane foams have been widely used by some MAKROFLEX, MASTERTEX, OLIMP and others.

The use of polyurethane foams of these firms allows the extrusion of relatively quickly to obtain insulation products directly in the repair process of household products, for example, when sealing joints, sealing windows, etc. (See instructions for use).

Known polyurethane foams are not without drawbacks. After extrusion, the foams also harden only in contact with air and in the presence of moisture. Moreover, the time of complete solidification is 24 hours, which in some cases is unacceptable in order to perform the required technological operations for the installation of glued products. And finally, when hardening, the volume of the obtained material also increases by 15-20%, which complicates the process of bonding various products, for example bath inserts.

Modern technology for the repair of sanitary products such as bathtubs, shower trays and other similar devices involves the use of adhesive compositions as a bonding adhesive layer. The practice of sealing and lining the liners for baths includes the operation of pressing the liner to the bearing surface due to water pressure. (See, for example, RF patent No. 2160668, IPC 7 В29С 73/04, published on 12/20/2000, in B.I. No. 35, or RF patent №2103174, 6 В29С 73/04 published. 01/27/98 in B.I. No. 3). In this case, the filling and holding times for the curing of the adhesive composition is desirable to withstand equal to 15-20 minutes With shorter curing times, the liner will rise unevenly, and alteration of the work performed is no longer possible. If known polyurethane foams are used as an adhesive composition, excessive bulging and limited air access to the adhesive layer also leads to marriage.

The aim of the invention is to provide acceleration of the curing of one-component polyurethane foams in accordance with the required technological process, in which the increase in the volume of the obtained products is minimized, and the curing time is 15-20 minutes after spraying, suitable for mounting glued surfaces, for example when repairing bathtubs or similar products .

Additionally, the task of rejecting polyurethane foam products without air access is being solved.

In the proposed method for the curing of one-component polyurethane foams of long-term storage, which consists in applying polyurethane foam to the surface by extrusion, according to the invention, ethylene glycol GOST 10164-75 of the classification “ChDA” is introduced into a cylinder containing ready-to-use polyurethane foam in the ratio of 35-50 ml of ethylene glycol per 750- 1000 ml of polyurethane foam in the bottle. This process is carried out without violating the sealing of the container by pressing its valve while introducing ethylene glycol. Then the mixture is shaken several times and then sprayed onto a surface previously prepared for this.

In a technical solution, a mixture of one-component long-term storage polyurethane foam with ethylene glycol in a ratio of 35-50 ml of ethylene glycol per 750-1000 ml of polyurethane foam in the cylinder is used to glue bath liners and pallets and other plumbing devices.

The proposed method for curing polyurethane foams is practically universal and can be used for all of these long-storage single-component polyurethane foams, the bulk of which is a prepolymer with terminal isocyanate groups, the content of NCO in which is from about 5 to 35 wt.% With terminal isocyanate groups. In this case, the time to complete solidification is 15-20 minutes, and the freezing process itself can occur with minimal access of air and moisture. The quality of the coating and the strength of the finished material is significantly increased, and the cost of work is significantly reduced.

Application example.

Ethylene glycol GOST 10164-75, classification “PSA”, is filled into a medical syringe without a needle with a volume of 35-50 ml. Then, the syringe opening is articulated with the cylinder head with one-component foam from MAKROFLEX MASTERTEX OLIMP et al., With a volume of 750-1000 ml, and ethylene glycol is injected into the cylinder. This process is carried out without violating the sealing of the container by pressing its valve while introducing ethylene glycol. After vigorous shaking, the mixture is ready for use. The mixture with the introduced hardener should be used within 15-20 minutes.

Claims (2)

1. A method of accelerating the curing of one-component polyurethane foams for long-term storage when it is used to extrude foam onto the surface, which consists in introducing ethylene glycol in a ratio of 35-50 ml per 750-1000 ml of the polyurethane foam in the cylinder into a container containing ready-to-use polyurethane foam, then the mixture is shaken several times and then sprayed on a surface previously prepared for this. 2. The method according to claim 1, which consists in the fact that a mixture of one-component long-term storage polyurethane foam with ethylene glycol in a ratio of 35-50 ml of ethylene glycol per 750-1000 ml of polyurethane foam is used for bonding liners for bathtubs and pallets and other plumbing products.