CS275811B6 - Impregnation bath for textile reinforcing materials - Google Patents

Abstract

To ensure good adhesion between reinforcing materials, especially polyamide and polyester and polyvinyl chloride-based mixtures, it is expedient to impregnate textile materials with a suitable impregnation bath. The impregnation baths used are usually based on plastisol and often contain adhesion promoters. The disadvantage of these baths is the relative complexity of their preparation and limited service life. According to the solution, textile reinforcing materials are impregnated with a bath containing at least 5% by weight of dry polyvinyl chloride latex. The bath may further contain up to 20% by weight of resin formed by the reaction of formaldehyde and monofunctional or multifunctional phenols, based on 100% by weight of dry polyvinyl chloride latex.

Description

The invention relates to an impregnation bath for textile reinforcing materials, intended in particular for connection with a mixture based on polyvinyl chloride.

Polyvinyl chloride products, whether conveyor belts, drive belts, hoses or other products, are becoming increasingly popular in various industries, especially in demanding conditions. The properties of these products are significantly improved by reinforcement with textile materials. For example, conveyor belts reinforced with polyamide cords or technical fabric containing polyamide fibers have higher strength and better resistance to impact and damage than conventional belts, have a longer service life and lower costs per tonne of material transported.

The mutual adhesion of the two components is important for the perfect combination of polyamide or polyester fibers with the polyvinyl chloride-based mixture. Technical fabrics used, for example, to reinforce conveyor belts often contain, in addition to polyamide or polyester fibers, a certain percentage of cotton fibers, which, by their rough surface, ensure the mechanical adhesion of the fabric to polyvinyl chloride. For cords or fabrics made only of polyamide or polyester, mechanical adhesion must be replaced by chemical adhesion. There are basically two ways to increase the adhesion of textile reinforcing materials to a polyvinyl chloride-based composition: impregnating the reinforcing materials with adhesion promoters or modifying the polyvinyl chloride composition, or a combination of these methods.

• Modifiers used in polyvinyl chloride blends, such as aromatic polyisocyanates, cyanuric acid derivatives or resorcinol-hexamethylenetetramine combinations, form substances during gelatinization that provide increased adhesion of textiles and polyvinyl chloride. The disadvantage of these systems is in most cases the release of toxic substances and the negative influence of some physical-mechanical properties of the mixture ηε based on polyvinyl chloride.

Impregnation baths for the reinforcing materials of polyvinyl chloride conveyor belts are often formed by sol shells. The composition intended for textile impregnation contains, for example, polyvinyl chloride, dibutyl phthalate, chlorinated paraffin, lead carbonate and fungicides. Adhesion promoters are also used to increase the adhesion between the textile materials and the polyvinyl chloride, for example a 70% solution of a mixture of linear and branched polyester alcohol from a mixture of ethyl acetate and methylene chloride containing a crosslinking agent, which may be isocyanates. The disadvantage of these impregnation baths is the relative complexity of their preparation due to the binding of individual ingredients to the mixtures, the preparation of the mixture itself and the limited life of the paste.

The disadvantage of said impregnation baths is eliminated by the impregnation bath for textile reinforcing materials, in particular polyamide and polyester, intended in particular for reinforcing the polyvinyl chloride-based mixture according to the invention. The essence of the invention lies in the fact that the impregnation bath contains at least 5% by weight. polyvinyl chloride latex solids. The impregnation bath may further contain up to 20 wt. d. resins formed by the reaction of formaldehyde and monofunctional or multifunctional phenols per 100 wt. d. polyvinyl chloride latex solids.

The advantage of the impregnation bath according to the invention is its simple preparation and low cost with very good adhesion values.

The following examples further illustrate the invention.

Example 1 '

Impregnations were prepared from 40% polyvinyl chloride latex by dilution with distilled water. baths of the composition listed in Table 1.

CS 275 811 36

Table 1 impregnation bath 123 45678 polyvinyl chloride latex (hr. D.) 100 87.5 75 60 50 37.5 2 5 12.5 distilled water (wt. D.) - 12.5 25 40 50 62.5 75 87, 5 concentration (%) 40 35 30 24 20 1 5 10 5

Polyamide and polyester cords impregnated with baths of the composition given in Table 1 were used for the preparation of test specimens for measuring adhesion according to ČSN 621462.

50.00 hni. d.

33.85

3.00

3.00

10.00

0.15

The adhesion values (M) measured for the prepared test specimens are given in Table 2. The mixture was further mixed with 6 wt. d. adhesion promoter (Vulcabond VP - 25% solution of isocyanate type polymer dibutyl phthalate). The adhesion values between this mixture and the non-impregnated polyamide cord are given under No. 9 in Table 2.- ’

Table 2 impregnation bath 1 23456789 non-impregnated adhesion cord-polyamide cord (N) 72 72 59 54 47 45 42 31 4ó 20 adhesion-polyester cord (Ji) 41 40 36 32 27 24 20 18 15

The table shows a significant increase in adhesion values when impregnating cords with polyvinyl chloride latex, especially evident in polyamide cord, where the adhesion value increases depending on the concentration of the bath - almost fourfold.

Example 2

A phenol-formaldehyde resin was prepared by condensing phenol and formaldehyde at 100 ° C. Composition of the reaction mixture: solid phenol 3.9 wt. d.

formaldehyde 38.4% 8.1 distilled water 88.0

Next, two impregnation baths containing phenol formaldehyde resin were prepared.

Composition of impregnation baths: bath no. 1 2 phenol formaldehyde resin .47.5 wt. d. 47.5 ta. d vinylpyridine latex, 40% 5.8 - butadiene styrene latex, 20% 46.7. - polyvinyl chloride latex, 40% - 29.1 Distilled water - 23.4

Polyamide and polyester cords impregnated with baths 1 and 2 and polyvinyl chloride paste were used to prepare test specimens for adhesion measurements according to ČSN 62'462, which measures the force required to pull the cord out of the body.

Composition of polyvinyl chloride paste:

CS 275 811 B6 polyvinyl chloride dioctyl phthalate trichlorethylene chloroparaffin micromilled limestone heat stabilizer

50.0 hrs. d.

33.85

3.0

3.0

10.0

0.1 5

The adhesion values measured for the test specimens are given in Table 3.

Table 3 bath ¢. 1 type of cord polyamide polyester adhesion (N) 15 13 polyamide polyester 57 48

Example 3

Resorcinol formaldehyde resin was prepared by condensing resorcinol and formaldehyde at 25 ° C for up to 5 hours.

Composition of the reaction mixture:

resorcinol 1.87 game. d.

formaldehyde, 38.4% and 2.70

NaOH, 10% n1.60 distilled water38.43

Next, two impregnation baths containing resorcinol formaldehyde resin were prepared.

Ingredients: impregnation baths: bath no.

resorcinformaldehyde resin vinylpyridine latex, 40% butadiene styrene latex, 20% natural rubber latex, 62% NH.OH, 2 5% distilled water polyvinyl chloride latex, 40%

To prepare test specimens for measurement

44.6 htn. d. 48.9 hro.d.

25,716.0 5,60,52,1

7.6-49.0 adhesion according to ČSN 621462, polyamide and polyester cords impregnated with baths 3 and 4 and the polyvinyl chloride paste mentioned in Example 2 were used.

The adhesion values measured for the test specimens are given in Table 4.

Table 4 bath No. 3 4 type of cord polyamide polyester polyamide polyester adhesion (N) 76 61 54

Furthermore, adhesion tests were performed according to ČSN 260370 (these are tests in which the cross-component adhesion is measured after detachment of the layers of test specimens).

The results of this test are shown in Table 5 ·

CS 275 811 B6

Table 5 impregnation bath latex PVC latex PVC latex PVC 10 wt. d. resorcinform. dry matter dry matter resin 32% 45% type of cord gray polyamide polyamide polyamide polyamide adhesion (N.mm ^- ^) 0.7 4.0 ¹ , 8 2.8

PATENT CLAIMS

Claims (2)

PATENT CLAIMS Impregnation bath for textile reinforcing materials, in particular polyamide and polyester, for reinforcing mixtures, in particular based on polyvinyl chloride, characterized in that it contains at least 5% by weight. polyvinyl chloride latex solids. 2. The impregnation bath according to claim 1, characterized in that it contains up to 20 wt. d. resins formed by the reaction of formaldehyde and monofunctional or multifunctional phenols per 100 wt. d. polyvinyl chloride latex solids.