DE2327215C3 - Method of treating a polyester fiber for use as a rubber reinforcing material - Google Patents

Description

1. Treating the polyester fiber in one step (i.e., a single bath process) using a modified »RFL« or a mixture of "RFL" and another adhesive or adhesives [this method was developed by the ICI Co. Ltd. develops and uses an adhesive made from 2,6-bis (2 ', 4'-dihydroxyphenylmeihvl) -4-chlorophenol],

2. Treatment of the polyester fiber in two stages (i. E. A two-bath), the fiber Wonn in spinning or immersion state is pretreated so as to facilitate the binding of "RFL" with the fiber, and it is then "RFL" treated,

3. A method of directly adhering the fiber to a rubber material by use an isocyanate-containing rubber solution

Of the processes listed above, processes 1 and 2 are used on an industrial scale.
However, method 1 does not give a sufficiently high

Liability, and method 2 has the disadvantage.

that the blocked isocyanate, the ethylene urea, the phenyl urethane or the epoxy resin, which in

The invention relates to a method for the pretreatment stage in the form of an organic Treatment of a synthetic polyester fiber to make a solvent solution, an emulsion or a watery is used as a rubber-reinforcing marshy dispersion, a poor stabiliterial to make more suitable. fact in these solutions and the liability between

Synthetic fibers such as f-caprolactam fibers, the fibers thus treated and the rubber regenerated cellulose, polyvinyl alcohol, polyesters 40 materials are insufficient, while on the other hand, etc., the production costs are already relatively high for the reinforcement of rubber.
products including tires, belts and It is now the object of the present invention to

Tubing has been used. The from f-Caprolac- a process for the treatment of synthetic polytam, regenerated cellulose and polyvinyl alcohol ester fibers to create the same for the existing ones Fibers can be made more suitable as a rubber reinforcement by impregnating them with 45 dung a resorcinol-formaldehyde resin-latex adhesive, using the procedure described above Avoids disadvantages of the known method.

This object is achieved with a method of treating a polyester fiber for use as a rubber-reinforcing material, which

1. A method for treating a polyester fiber for use as a rubber reinforcing material, characterized in that the fiber is first in a liquid bath of a reaction product based on allyl (3-hydroxyphenyl) ether, which is obtained by heating a mixture of 1 mole of resorcinol and 0.1 to ί mol of alkali metal hydroxide and addition of an allyl halide in a molar ratio of 0.1 to 1.0 mol per mol of resorcinol has been obtained in an organic solvent, and then immersed in a customary resorcinol-formaldehyde condensate latex solution and is finally dried at a temperature of 150 to 250 ⁰ C, whereby the reaction product of formaldehyde and ammonia are added in aqueous solution additionally.

2. The method according to claim 1, characterized in that the fiber is in a liquid bath of a reaction product based on ailyl (3-hydroxyphenyl | -ether is immersed by heating a mixture of 1 mol of resorcinol and 0.3 to 0.7 mol of alkali metal hydroxide and Addition of an allyl halide in a molar ratio of 0.3 to 0.7 mol per mol of resorcinol in an organic solvent.

which is generally referred to as "RFL" and which is also referred to below under this designation will be made to adhere strongly to the rubber.

On the other hand, polyester fibers do not adhere well to rubber materials, even if they are impregnated with "RFL" are.

It is believed that the inadequacy of the polyesters in this regard is extraordinary poor functionality of the molecular structure of synthetic polyester fibers, d. H. on the rarity of the reactive, functional groups.

is characterized is that the fiber is first placed in a liquid bath of a reaction product on the basis of Allyl (3-hydroxyphenyl) ether, which is obtained by heating a mixture of 1 mol of resorcinol and 0.1 to 1 mol Alkali metal hydroxide and addition of an allyl halide in a molar ratio of 0.1 to 1.0 mole per mole of resorcinol in an organic solvent as well as below

In general, however, it is precisely the synthetic products that have been converted into a common resorcinol-formaldehyde condensate

Polyester fibers see excellent results in comparison with the other fiber materials mentioned above Properties in terms of tensile strength, impact resistance, resistance to elongation, dimensional stability, thermischi; Resistance, water resistance, resistance to chemicals, Weather resistance, etc. For this reason, synthetic polyester fibers have physical egg latex solution is immersed and finally dried at a temperature of 150 to 250 ° C, wherein formaldehyde and ammonia are additionally added in aqueous solution to the reaction product.

The present invention is thus a two-step treatment method. In the first stage, a solution is applied to a polyester fiber, which is a Reaction product au ;; Resorcinol, an allyl halo

23 215

OH

+ XCH ₂ CH = CH ₂ + MOH

OCH ₂ CH = CH ₂

+ MX + H ₂ O

• contains enide and an alkali metal hydroxide. the Polyester fiber is then treated in a second stage by adding a conventional latex condensate »Resorcinol and formaldehyde is applied.

Applying these solutions by immersion © the other conventional means results in a coated one or impregnated fiber.

It has been found that the fibers treated in this way have an extremely high level of adhesion to rubber materials exhibit.

It has proven to be particularly advantageous if, for the formation of the impregnation material, the first In the treatment stage a liquid bath is used, by heating a mixture of 1 mole of resorcinol and0.3 to 0.7 moles of alkali metal hydroxide and addition of an allyl halide in a molar ratio of 0.3 to 0.7 mol per mol of resorcinol in one organic solvent has been obtained.

The reaction product used in the first treatment stage contains allyl- (3-hydroxyphenyl) -fither and derivatives and polymers thereof as the main ingredient.

Formaldehyde and ammonia are then added to the reaction product to reduce the Form treatment solution for the first stage.

The reaction of resorcinol, an allyl halide and an alkali metal hydroxide creates a solution, which is used in the first stage of the present invention, and which as the main ingredient is allyl (3-hydroxyphenyl) ether which has been formed according to the following reaction formula:

wherein X represents a halogen and M represents an alkali metal: From infrared spectral analysis it is found that Ether bonds are present in the reaction product and MX (i.e. KBr or NaBr) through the reaction has been formed, so that the main reaction product as allyl (3-hydroxyphenyl) ethers and derivatives and polymers thereof can be viewed.

The reaction product used as the first-stage treatment liquid of the present invention is made by using a small excess of resorcinol, i. i.e., 1 mole of resorcinol is added to 0.1 to 1.0 mol, preferably 0.3 to 0.7 Μοί, νοη each the allyl halide and the alkali metal hydroxide are used.

The reaction product can easily be obtained by thermal melting of an excess of resorcinol and an alkali metal hydroxide and then gradually adding dropwise a halogenated one Allyls can be produced to the starting reaction.

The reaction product obtained is dissolved in methanol, and the alkali metal halide produced in the 2nd place is removed by filtration. The product is then removed by distilling off the methanol.

perked up.

Alternatively, the reaction can also be carried out in the presence of an organic solvent, such as Methanol, ethanol, n-propanol, isopropanol, acetone, ether or tetrahydrofuran.

The first bath used in the process according to the invention contains the reaction mixture obtained, which in turn contains unreacted resorcinol, Allyl (3-hydroxyphenyl) ethers, their derivatives and polymers. Suitable allyl halides used in the preparation of a mixture or solution can be used for the first treatment bath, include allyl bromide, allyl chloride, allyl iodide, and allyl fluoride. Allyl bromide and allyl chloride preferred. The preferred alkali metal hydroxides are sodium hydroxide and potassium hydroxide.

In order to adapt the above reaction mixture for use in the first stage of the process of the invention, formaldehyde is first added to the reaction product and then aqueous ammonia is added to form an alkaline aqueous solution.

Formaldehyde can be added to the reaction product up to the critical point which the product gels. Experiments showed that the critical amount of formaldehyde is proportional with the Meng ·; of the resorcinol changes in the reaction mixture remains.

The treatment solution described above is applied to the polyester fiber in a conventional manner applied, d. that is, the fiber is immersed in the treatment solution and at a temperature of 150 dried up to 250 C.

This treatment solution has excellent chemical and physical stability, so that it it is possible to preserve the solution over a relatively long period of time. In addition, the treatment solution is easily miscible with water, and therefore it is not necessary to add the solution by using a dispersing agent or an emulsifying agent dilute or use a colloid grinder.

The synthetic polyester fiber treated as described above is then RFL in the second stage treated in a manner similar to that in the first stage.

When the polyester fiber subjected to the above-described two-stage treatment in tight Contact is made with an unvulcanized rubber which contains suitable additives an extremely high degree of adhesion between the fiber and the rubber by thermal vulcanization of the rubber as shown in the examples described below.

The various factors that affect the adhesion of the RFL treated fiber to rubber, include the molar ratio of resorcinol to formaldehyde in the RFL, the reaction conditions for the condensation reaction of resorcinol and formaldehyde, the mixed weight ratio of the resorcinol-formaldehyde condensate and latex, the type of latex used, the aging time of the RFL, the temperature of the RFL treatment and the particular one A gunimi composition to which the fiber is adhered.

The strong adhesion of rubber to fibers, such as i-caprolactam and regenerated cellulose, which by the one-step treatment with RFL will be given, is attributed to the fact that such fibers contain therein functional groups that are responsible for a

such adhesion are effective. On the other hand, polyester fibers do not have such functional or polar groups. The polyester fibers useful for rubber reinforcement have a high degree of crystallinity and orientation so that the resulting polyester fiber, when treated with only RFL alone, will not adhere as tightly to a rubber; like the RFL treated e caprolactam or the regenerated cellulose.

Accordingly, it becomes unexpected and unusual considered that a polyester fiber by a two-stage treatment according to the present Invention can be treated to provide as strong an adhesion to a rubber as the aforementioned fiber types that have been treated with RFL alone is the case.

The present invention is further illustrated by the following examples:

example 1

I. Preparation of the reaction product from resorcinol, an allyl halide and an alkali metal hydroxide

Five different reaction solutions were prepared using those given in Table 1 below Prepared compositions, with AHylbromide fils the allyl halide and potassium hydroxide the Alkali metal hydroxide was used.

Table 1

component

Experiment no.
1 2 3

Resorcinol

AHyl bromide
tcotassium hydroxide

110.0
(1.0)
12.1
(0.1)
5.6
(0.1)

110.0 110.0 110.0
(1.0) (1.0) (1.0)
60.5

36.3
(0.3)
16.8
(0.3)

(0.5)

28.0

(0.5)

84.7
(0.7)
39.2
(0.7)

110.0 (1.0)

108.9 (0.9) 50.4 (0.9) by using e.g. B. allyl chloride than that Ayl halide and sodium hydroxide can be obtained as the alkali metal hydroxide.

2. Preparation of the bath solution for use
in the first impregnation stage

110 g of each of the five different reaction mixtures obtained above (experiments No. 1 to 5), were placed in five different flasks and thermally dissolved at 100 to 120C. Then, formaldehyde was slowly added dropwise with stirring and in those indicated in Table 2 Quantities added to each flask. In no case did the addition of formaldehyde cause the Solution gelled. Then, aqueous ammonia was added to each flask in those shown in Table 2 Quantities added to make five different treatment solutions to obtain.

table

Experiment no. of the reaction product

12 3 4 5

35

The values without brackets are given in weights and the values in brackets in moles.

Resorcinol and potassium hydroxide were melted in a flask at 12O ⁰ C, and to this melt AHylbromid was slowly added dropwise with stirring. The resulting reaction product was dissolved in methanol and filtered to remove potassium bromide, a secondary product, therefrom. Then the methanol was removed by distillation. The resulting products contained a mixture of resorcinol, allyl (3-hydroxyphenyl) ethers and derivatives and polymers of ether in yields of 110 to 145 g. The yield varied with the composition of the reaction. The content of allyl (3-hydroxyphenyl) ether in the product increased as the amount of AHyl bromide and potassium hydroxy reactants increased, that is, when the composition was varied from 1 to 5 as shown in Table 1. Although alyl bromide and potassium hydroxide were used in the experiments given above, formaldehyde could give similar results
(37%), g
Watery
ammonia
(28%), g
Water, g
Test number

43 34 24 14 5

30 30 30 30 30

440 440 440 440 440

10 11 12 13 14

The treatment solutions thus obtained were dark brown in color and had a solid content of 20 to 24% (determined by JIS K 6 387) and a pH of 9.3 to 9.7. To the real one Application, these solutions were diluted with water to provide solutions that were 1 to 5 percent by weight Contained solids.

45

3. Impregnation treatment of synthetic
Polyester fibers

The five treatment solutions prepared as described above were each divided into three portions, and each portion was diluted to a solids concentration of 1.3 and 5 percent by weight, respectively (making a total of 15 test solutions). The polyester fiber that is manufactured by Teijin KK, was immersed a dilute treatment solutions of these in each case, provisionally at 120 ° C for 4 minutes then dried and thermally treated for 2 minutes at 230 C ^c. The fibers that had been treated with the various solutions of the first stage were then immersed in the corresponding solutions (RFL) of the second stage. Each second stage solution had a composition approximately similar to that in Table 3 below. The twice treated fibers were then preliminarily dried at 120 ° C. for 4 minutes and subjected to further heating at 230 ° C. for 2 minutes.

Table 3

Water 472.15 (g)

Sodium hydroxide (10% aqueous

Solution) 11.22

Aqueous ammonia (28%) 30.90

Initial condensate from resor-

cin-formaldehyde (45%) 62.33

Styrene-butadiene latex (40%) 219.17

Vinyl pyridine terpolymer latex. . 175.39 Formaldehyde (37%) 28.90

Test for adhesion to rubber

The five different two-stage treated tire cords obtained in this way became separated into unvulcanized rubber samples of mm length, which have the composition given in Table 4 possessed, embedded. These five rubber compositions were then left for 30 minutes long thermally treated at 148 ° C for the purpose of vulcanization. The vulcanized test samples were subjected to the test for adhesion.

Table 4 Weight scales

Sheet rubber RSS No. 3 100.0

Zinc oxide 5.0

Stearic acid 2.0

(jcuichlstcilc

Oil-gas-soot 30.0

Antioxidant 1.0

Aromatic oil 7.0

Sulfur 2.25

Accelerator 1.0

For comparison, two similar tire cords were treated, the first (test no. 15) becoming one Subjected to one stage treatment using RFL alone and the second (Test No. 16). the treated in the first stage with an epoxy treatment solution similar to that shown in Table 5 had the composition shown (instead of the resorcinol - allyl halide - alkali metal hydroxide bath), was treated with RFL in the second stage. Both samples were tested together with the adhesion test subjected to test samples 10-14.

Table 5

Isooctyl-phenyl-polyethoxy alcohol 0.4 cm ^J Diphenyl blocked with phenol

methane diisocyanate 16.0 g

Dimethylaminoethyl methacrylate

(0.5% aqueous solution) 25.0 cm ³

Diglycidyl ether of glycerol .... 4.8 cm ³

£ 09 622/275

Claims (1)

Patent claims: ■ ο properties that are best suited door the reinforcement of rubber products. Accordingly, there is a need to improve the adhesion of synthetic polyester fibers to rubber products. Various methods have been proposed to prevent the polyester fibers from adhering to them Improve rubber. The following can be mentioned as such: