JPH0529707B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an improvement in the adhesion treatment method between a polyester fiber material and an elastomer composition, especially a rubber composition. The present invention relates to a method for adhering polyester fiber materials using an adhesive with a new composition that enables high-quality products. BACKGROUND OF THE INVENTION As is well known, industrial rubber products such as vehicle and aircraft tires, hoses, conveyor belts, power transmission belts, etc. are designed to increase the tensile strength of these products to reduce the degree of deformation under severe conditions. It is generally reinforced with a fibrous material that serves as a restraint. In recent years, as polyester fibers have been developed, polyester fibers have also come to be used as fiber materials for reinforcing these rubbers, and polyester fibers in particular have high strength and toughness, as well as excellent dimensional stability. It has extremely favorable physical properties as a rubber reinforcing material. However, when using polyester fibers as such reinforcing materials, polyester has a dense fiber structure and few functional groups, so nylon,
There was a problem in that sufficient adhesion could not be obtained only with RFL liquid consisting of resorcinol, formalin, and rubber latex, which is an adhesive capable of adhering fibers such as rayon and rubber compositions well. In order to improve this, (1) a method of applying an adhesive pretreatment agent such as an epoxy resin to the yarn, (2) a method of applying an adhesive pretreatment agent such as an epoxy resin to the yarn, and (2) a method of applying an adhesive pretreatment agent such as an epoxy resin or an isocyanate adhesive,
(3) A two-stage treatment method in which epoxy resin/isocyanate compound/rubber latex is treated in the first stage and then treated with RFL and a polyisocyanate compound (see JP-A-54-77796), etc. Various adhesive processing methods have been proposed. However, method (1) above is very complicated in terms of production control due to dirt on the pretreatment agent applying device, and method (2) above improves initial adhesion strength, but has poor heat-resistant adhesive strength. Furthermore, although the method (3) above can ensure a very high level of initial adhesive strength, the heat-resistant adhesive strength is not sufficient, and there is a lot of rough adhesion of dips to the fabric during processing, which significantly deteriorates the quality of the fabric. There are problems that can lead to damage, and the current situation is that a method that is satisfactory in all respects has not yet been developed. Problems to be Solved by the Invention The present inventors have discovered that when adhesion between a polyester fiber material and a rubber composition is carried out industrially, as described above, conventional adhesives that have high initial and heat-resistant adhesive strength and that are resistant to dip processing. An adhesive treatment method that solves the problem that there is no adhesive treatment method that can improve the quality of dip-processed fabrics, significantly improves the initial and heat-resistant adhesive strength compared to conventional methods, and achieves both high-quality dip-processed fabrics. As a result of intensive study to develop the present invention, the present invention has been completed. Means and Effects for Solving the Problems According to the present invention, when bonding a polyester fiber material with an elastomer composition, the fiber material is impregnated with an aqueous solution containing polyethyleneimine as a first stage treatment, and then A method for adhering polyester fiber materials is provided, which comprises impregnating the material with a solution containing a blocked polyisocyanate compound and resorcinol-formalin-rubber latex (hereinafter referred to as RFL/I solution) and heat-treating the material as the second stage treatment. In the present invention, the polyester fiber material is
A knitted fabric composed of long fibers and/or short fibers containing linear polymeric polyester fibers containing ester bonds in the molecule and highly oriented in the fiber axis direction, such as polyethylene terephthalate fibers and polybutylene terephthalate fibers. , woven fabrics, braids, cords, ropes, or mixtures thereof, and some of them are fiber materials other than polyester fibers, such as polyamide fibers, aramid fibers, rayon fibers, vinylon fibers, etc., which are usually used as rubber reinforcement materials. It may be included. In the method of the present invention, the polyesterimine used as the first-stage treatment liquid has good adhesive properties during low-temperature heat treatment, and even at a low concentration, it has remarkable adhesive properties compared to conventional ones, and other compounds such as epoxy Such characteristics cannot be obtained with resins or polyisocyanate compounds. As the polyethyleneimine, a common compound obtained by polymerizing ethyleneimine may be used, and the degree of polymerization is not particularly limited, but it is preferable to use one having a degree of polymerization of about 200 to 2000, for example. The concentration of the polyethyleneimine aqueous solution is not particularly limited as long as it ensures a good adhesion level, but a concentration of about 0.1 to 2.0% by weight is preferred, for example. Although polyethyleneimine may be used alone in the first stage treatment liquid used in the method of the present invention,
Other agents may be included to increase adhesive strength. Such agents may be those that do not impair the stability or adhesion of the treatment liquid, and are not specified, but include, for example, adhesion activation aids and stabilizers commonly used in rubber latexes, isocyanate compounds, etc. , thickeners, antifoaming agents, dispersants, softeners, etc. may be added. The first-stage treatment liquid can be applied to the polyester fiber material by any method such as dipping, coating, and spraying. The amount of the first-stage treatment liquid deposited on the fiber material to be treated is suitably 1 to 3% by weight based on the amount of the fiber material. The heat treatment after application may be performed subsequent to the drying step, or the drying step may be omitted. Although there is no particular limitation on the temperature of this treatment, for example, the drying treatment may be carried out at a temperature of 100 to 160°C for 1 to 5 minutes, and the heat treatment may be carried out at a temperature of 160 to 200°C for 1 to 3 minutes. In the method of the present invention, used for the second stage treatment liquid.
RFL/I liquid is essential for obtaining initial adhesive strength, heat-resistant adhesive strength, and adhesive stability, and RFL alone or a mixture of RFL and a compound other than the blocked polyisocyanate compound achieves the purpose of the present invention. I can't. Although there is no particular limitation on the solid content of the blocked polyisocyanate compound in the RFL/I liquid used in the method of the present invention, it is generally, for example, 1 to 5% by weight.
The amount is preferably 2 to 3% by weight. Any RFL liquid can be used as long as it is used in normal adhesive formulations, preferably with an R/F ratio of 1/1 to 1/1.
1/2, the RF/L ratio is preferably in the range of 1/5 to 1/10, and the total solids weight % is preferably about 10 to 20%. The blocked polyisocyanate compound used in the process of the invention is an addition compound of a polyisocyanate compound and a blocking agent. As such polyisocyanate, for example, metaphenylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, triphenylmethane triisocyanate, etc. can be used. On the other hand, examples of blocking agents include phenols such as resorcinol, cresol, phenol, and thiophenol; aromatic secondary amines such as diphenylamine and xylidine; imides such as phthalic acid imide; lactams such as caprolactam and parerolactam. ; Tertiary alcohols such as t-butanol and t-pentanol can be used. The second-stage treatment liquid can be applied to the polyester fiber material subjected to the first-stage treatment described above by any method such as dipping, coating, and spraying. There is no particular limit to the amount of the second-stage treatment liquid attached, but it is 2 to 5% by weight of the adhered content to the fiber material.
is appropriate. The heat treatment after applying the second-stage treatment liquid may be a drying step followed by a tension heat treatment, or the drying step may be omitted. Although there is no particular limitation on the treatment temperature, it is appropriate to perform drying at a temperature of 100 to 160°C for 1 to 5 minutes, and heat treatment at a temperature of 200 to 250°C for 1 to 3 minutes, for example. The polyester fiber material thus treated in two stages can be embedded in a rubber composition and vulcanized and bonded in accordance with a conventional method. According to the method of the present invention, following the conventional method, for example (1) epoxy resin or isocyanate compound, RFL
(2) A two-stage treatment method in which epoxy resin, isocyanate compound, and rubber latex are treated in the first stage, followed by treatment with RFL and a polyisocyanate compound. The quality of the processed fabric can be significantly improved by strongly adhering the two. Although the method of the present invention is effective for rubber compositions, elastomers other than rubber, such as polyvinyl chloride, ethylene/vinyl acetate, fluorinated vinyl,
It can be applied to elastomers such as polyolefins. Examples Examples of the present invention will be described below, but it goes without saying that the technical scope of the present invention is not limited to these examples. Example 1 3 parts by weight of polyethyleneimine (Epomin SP-003, manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd.) and 957 parts by weight of water were mixed to prepare a 0.3% by weight first stage treatment liquid.
On the other hand, 14 parts by weight of resolmin and 16 parts by weight of a 37% by weight formalin aqueous solution were mixed, and this was used as a catalyst.
8 parts by weight of a 10% by weight aqueous solution of caustic soda and 464 parts by weight of water were added, and the mixture was aged for 6 hours. The liquid thus obtained was mixed with 438 parts by weight of vinyl pyridine rubber latex and 60 parts by weight of water, and aged for 24 hours to prepare an RFL liquid with a total solid content of about 20% by weight. Adhesive treatment and heat treatment were performed using a computer treater manufactured by Ritzler, USA. 1500d／
2. After impregnating a polyester cord manufactured by Asahi Kasei Industries, Ltd. with a twisted structure of 40 x 40 T/dm with the first stage treatment solution, it was dried at 130°C for 2 minutes, and then dried at 160°C.
The sample was heat-treated for 1 minute. Subsequently, the above prepared
Dispersion of RFL liquid and 25% by weight MDI-caprolactam block (DMS-3, manufactured by Meisei Chemical Industry Co., Ltd.)
2nd stage treatment liquid (RFL/I liquid) mixed with 120 parts by weight and water necessary to make the solid content approximately 20%
After drying at 150℃ for 2 minutes, under 1% tension.
Heat treatment was performed at 245°C for 1 minute. The obtained treated cord was embedded in unvulcanized tire carcass rubber made of a mixture of natural rubber and styrene-butadiene copolymer rubber, and vulcanization was performed at 150°C for 30 minutes to bond the treated cord and rubber. Ta. The adhesive strength was determined by measuring the pull-out force of a 1 cm long embedded rubber cord at room temperature. This is the initial adhesion test. On the other hand, the treated cord was embedded in unvulcanized rubber for a tire carcass, and vulcanized at 180°C for 60 minutes to bond it.
The pull-out force was measured under the same conditions as described above. This is called a heat resistant adhesion test. The results obtained were as shown in Table 1. As is clear from the results in Table 1, according to the adhesive treatment method of the present invention, the initial and heat-resistant adhesive strength was significantly improved, and almost no deposits such as dip residue were observed on the surface of the treated cord. . Comparative Example 1 According to Example 1, a cord treated in the first stage was impregnated with the blocked polyisocyanate compound without adding it to the second stage treatment solution, and then an adhesion test was conducted. The results obtained are shown in Table 1, and
In the adhesive treatment method that does not add blocked polyisocyanate to the stage treatment solution, the initial adhesive strength is 15.5 kg/cm,
The heat-resistant adhesive strength was 6.7 kg/cm, which was much lower than the adhesive strength when treated with the second stage treatment liquid (RFL/I liquid) according to the treatment method of the present invention. Example 2 First-stage treatment solutions with polyethyleneimine polymerization degrees of 300 and 2000 were prepared in the same manner as in Example 1, impregnated into a cord, heat-treated at 180°C for 2 minutes, and then impregnated into the second-stage treatment solution. Then, after drying at 150°C for 2 minutes, heat treatment was performed at 245°C for 1 minute, and an adhesion test of the post-treated cord was conducted. The results obtained are shown in Table 1. As is clear from the results in Table 1, in the adhesive treatment method according to the present invention, the influence of the degree of polymerization of polyethyleneimine used in the first-stage treatment liquid on adhesiveness is particularly problematic within the above degree of polymerization range. Not,
It was found that both initial and heat-resistant adhesive strength showed good results. Example 3 First-stage treatment solutions containing polyethyleneimine aqueous solutions having concentrations of 0.2, 0.5, and 1.0% by weight were prepared in the same manner as in Example 1, and the relationship between the weight concentration% and adhesiveness was investigated. The results obtained are shown in Table 1. As is clear from the results in Table 1, the first sample with various weight concentration percentages of the polyethyleneimine aqueous solution was used.
It has been found that extremely good adhesive strength can be obtained even when the stage treatment liquid is used. Example 4 In the same manner as in Example 1, a crude MDI-caprolactam block and a TDI-prepolymer butanone oxyblock were used in the first stage treatment for the blocked polyisocyanate of the second stage treatment liquid (RFL/I solution). An adhesion test was conducted by impregnating the cord. The results obtained are shown in Table 1. As is clear from the results in Table 1, it was found that excellent adhesiveness could be obtained regardless of the type of blocked polyisocyanate compound. Comparative Example 2 5 parts by weight of epoxy resin, 60 parts by weight of blocked polyisocyanate and 685 parts by weight of water were mixed, and 250 parts by weight of vinyl pyridine rubber latex was mixed thereto to prepare a first stage treatment liquid, and then the treatment solution was prepared. A second stage treatment liquid (RFL/I liquid) similar to that in Example 1 was prepared. After impregnating a polyester cord with the above-mentioned first-stage treatment liquid, it was heat-treated, then impregnated with the second-stage treatment liquid and heat-treated, and then embedded in tire carcass rubber and vulcanized, and the adhesive strength was measured. . The results obtained are shown in Table 1. As is clear from the results in Table 1, good initial adhesion strength is obtained as in the case of using the first-stage treatment liquid according to the present invention, but no improvement in heat-resistant adhesive strength was observed. It was found that there was a lot of dip lees adhering to the cord after treatment, impairing the quality of the processed fabric.

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Claims (1)

[Claims] 1. When adhering a polyester fiber material to an elastomer composition, the fiber material is impregnated with an aqueous solution containing polyethyleneimine as a first step treatment, and then impregnated with a blocked polyisocyanate compound and resorcin formalin as a second step treatment. - Impregnated with a solution containing rubber latex,
A method for adhesion processing of polyester fiber materials, characterized by heat treatment.