JP2016069526A - Adhesive for fiber and rubber, and producing method of adhesive for fiber and rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive for fiber and rubber that adhesiveness with fiber and rubber is good and process passability in production of products such as automobile hose, that is falling of RFL of fiber surface is improved.SOLUTION: An adhesive for fiber and rubber contains resorcin formaldehyde copolymer and rubber latex, and not less than two kinds of resorcin formaldehyde copolymers are added.SELECTED DRAWING: None

Description

  The present invention relates to a fiber / rubber adhesive. More specifically, the present invention relates to an adhesive for fibers and rubbers, which can satisfactorily bond fibers and rubber and improve process passability in manufacturing rubber products such as automobile hoses, that is, resin removal on the fiber surface.

  Fibers have excellent physical properties such as high strength and high elastic modulus, and are conventionally used as reinforcing materials for tire cords, power transmission belts, rubber hoses and the like.

  When using a fiber as a rubber reinforcing material, it is necessary to firmly bond the fiber and the rubber in order to sufficiently exhibit its function. In general, when a fiber and rubber are bonded, an adhesive treatment liquid (hereinafter sometimes abbreviated as RFL) composed of a mixture of resorcin / formaldehyde initial condensate (RF) and rubber latex is applied to the fiber, dried and baked. Then, after obtaining an adhesive-attached fiber, a technique of vulcanizing and bonding the adhesive-attached fiber and rubber is used.

  In recent years, however, polyester fibers and aramid fibers are often used as hoses, and EPDM rubber and butyl rubber are often used as rubbers. These materials, which have low reactivity with adhesives, are high. It is difficult to obtain adhesive strength.

  As a means to improve adhesion, a method of treating fibers with an adhesive mixed with resorcin-formaldehyde initial condensate, melamine resin and other formaldehyde-reactive resin, rubber latex and blocked isocyanate is proposed. (See Patent Document 1). Separately, a method of treating with an adhesive in which three components of parachlorophenol / resorcin / formaldehyde co-condensate, rubber latex, and initial condensate of resorcin / formaldehyde are mixed has been proposed (see Patent Document 2). Furthermore, a method of treating with a mixed adhesive of a sulfomethylated product or a sulfimethylated product of a condensation product of a phenol and an aldehyde having a methylol group, a rubber latex, and an initial condensate of resorcin / formaldehyde has been proposed ( (See Patent Document 3.)

JP 2009-174105 A (Claims) JP 2003-206461 A (Claims) JP 2000-034455 A (Claims)

  However, all of the proposals in the above-mentioned patent documents have the problem that the improvement in adhesiveness is recognized, but it is not sufficient, or the RFL is dropped when the hose is braided and the process passability is poor.

  Accordingly, an object of the present invention is to provide a fiber / rubber adhesive having good adhesion between rubber and fibers and improved process passability, in view of the background of the above-described prior art.

  The present invention is to solve the above-mentioned problems, and employs the following means.

  That is, the fiber / rubber adhesive of the present invention is a resorcin / formaldehyde copolymer and a fiber / rubber adhesive containing a rubber latex, and the resorcin / formaldehyde copolymer comprises two or more resorcin-formaldehyde copolymers. It is an adhesive for fibers and rubber that is made by adding a product.

In the fiber / rubber adhesive of the present invention, the following (1) to (4) are more preferable conditions, and by applying these, further excellent effects can be expected.
(1) The two or more resorcin-formaldehyde copolymers include a combination of resorcin-formaldehyde copolymers and / or resorcin-formaldehyde copolymers having different ripening levels in the same composition.
(2) The two or more types of resorcin / formaldehyde copolymers include resole type resorcin / formaldehyde copolymer and novolac type resorcin / formaldehyde copolymer (3) of the novolac type resorcin / formaldehyde polymer (A) The mass ratio [A / B] to the resole-type resorcin / formaldehyde polymer (B) is A / B = 1/1 to 1/5.
(4) The rubber latex contains 30% by mass or more of chloroprene latex in the solid content of the entire rubber latex.

  The present invention also provides a method for producing a fiber / rubber adhesive in which two or more resorcin / formaldehyde copolymers are added in producing a fiber / rubber adhesive containing a resorcin / formaldehyde copolymer and a rubber latex. is there

  According to the present invention, in the conventional rubber reinforcing fiber, the fiber adhesiveness that could not be achieved so far is good, and the process passes at the time of manufacturing a product such as an automobile hose such as dropping of RFL on the fiber surface. A fiber / rubber adhesive capable of providing a rubber reinforcing fiber that improves the properties is obtained.

FIG. 1 is a schematic diagram showing a friction tester for evaluating the processability of a fiber cord.

  Next, the fiber / rubber adhesive of the present invention will be described in detail.

  The fiber / rubber adhesive of the present invention is an adhesive containing a resorcin / formaldehyde copolymer and a rubber latex, and is obtained by adding two or more resorcin / formaldehyde copolymers as a resorcin / formaldehyde copolymer. It is.

  The resorcin / formaldehyde copolymer is obtained by condensing resorcin and formaldehyde, and the molar ratio (R / F) of resorcin (R) to formaldehyde (F) is R / F = 1 / 0.5 to 1 It is preferably in the range of / 3, more preferably in the range of 1/1 to 1 / 2.5. When the molar ratio of R / F is out of the range of R / F = 1 / 0.5 to 1/3, the adhesiveness may decrease or the process passability may deteriorate.

  The resorcin / formaldehyde copolymer is obtained by condensing resorcin (R) and formaldehyde (F). Examples of the resorcin / formaldehyde copolymer that can be used include resole type resorcin / formaldehyde copolymer and novolac type resorcin / formaldehyde copolymer.

  The resole-type resorcin / formaldehyde copolymer reacts in the range of R / F = 1/1 to 1/3 with an R / F molar ratio of resorcin (R) and formaldehyde (F) in the presence of an alkali catalyst. Resorcin / formaldehyde copolymer. Especially, it is preferable that the molar ratio of R / F is R / F = 1/1 to 1 / 2.5.

  As said alkali catalyst, an alkali metal hydroxide is used suitably, More preferably, sodium hydroxide etc. are mentioned. The concentration of the alkaline catalyst aqueous dispersion is preferably about 1 to 10 molar.

  The resole type resorcin / formaldehyde copolymer is aged to react resorcin (R) with formaldehyde (F) in the presence of an alkali catalyst as described above. It is preferable to make it 0.5 to 6.0 hours below. By using the above-mentioned aging conditions, it is particularly excellent in process passability and adhesiveness, and the viscosity can be easily increased and the adhesive can be easily applied uniformly to the fibers.

  The novolak copolymer reacts with resorcin (R) and formaldehyde (F) in an R / F molar ratio in the range of R / F = 1 / 0.3 to 1/1 under no catalyst or acidic catalyst. Resorcin / formaldehyde copolymer. Among them, a resorcin / formaldehyde copolymer obtained by reacting with an R / F molar ratio in the range of R / F = 1 / 0.7 to 1/1 under an acidic catalyst is preferable. Although there is no restriction | limiting in particular as an acid catalyst, Hydrochloric acid, a sulfuric acid, phosphoric acid, p-toluenesulfonic acid etc. are used suitably. The acid catalyst is preferably in the range of 0.0001 mol to 1 mol with respect to 1 mol of resorcin.

  The novolak-type resorcin / formaldehyde copolymer reacts resorcin (R) with formaldehyde (F) in the presence of no catalyst or acid catalyst as described above, and the aging condition is a condition of 100 to 200 ° C. It is desirable to heat to reflux under normal pressure. The reaction time at that time is preferably 0.1 to 6.0 hours. By using the above-mentioned aging conditions, it is particularly excellent in process passability and adhesiveness, and the adhesive can be easily applied uniformly to the fibers without increasing the viscosity.

  As the novolak-type resorcin / formaldehyde copolymer, it can also be used as a novolak-type resorcin / formaldehyde copolymer polymerized at a ratio of formaldehyde to 1 mol of resorcin less than the preferred range. In that case, after the resorcin / formaldehyde copolymer obtained by polymerization is dissolved in an alkaline catalyst aqueous dispersion, formaldehyde is added, and the molar ratio of resorcin and formaldehyde is adjusted to a preferred range and ripened to achieve a preferred ratio. A copolymer obtained by copolymerization with can be obtained. For example, a compound (for example, trade name “SUMIKANOL” 700 (S) (registered trademark), manufactured by Sumitomo Chemical Co., Ltd.)) which reacts with 1 mol of resorcin at a concentration of 0.7 mol or less is commercially available. When a compound having a small amount of formaldehyde used with respect to such resorcin is desired and the molar ratio of resorcin (R) to formaldehyde (F) is to be within the above preferred range, the above-described novolak copolymer of resorcin and formaldehyde It is a preferred embodiment that formaldehyde is added after the solution is dissolved in an alkaline catalyst aqueous dispersion to adjust the molar ratio of resorcin to formaldehyde.

  In the present invention, two or more kinds of resorcin / formaldehyde copolymers are used, but resorcin / formaldehyde copolymers having the same composition or different ripening levels may be used, or resorcin / formaldehyde copolymers having different compositions. May be used. Further, these combinations may be used. For example, when two or more kinds of resorcin / formaldehyde copolymer include resorcin / formaldehyde copolymer and novolac / resorcin / formaldehyde copolymer, resorcin / formaldehyde copolymer, Examples include a resorcin / formaldehyde copolymer having a different composition such as a copolymerization ratio of formaldehyde, and a resorcin / formaldehyde copolymer having a different maturity even if the composition is the same.

  In particular, when a resole type resorcin / formaldehyde copolymer and a novolac type resorcin / formaldehyde copolymer are included, it is more preferable that a resorcin / formaldehyde copolymer having a different maturity is used even if the composition is the same. More preferably, it contains a formaldehyde copolymer and a novolac-type resorcin / formaldehyde copolymer. Most preferred is a case where a resole type resorcin / formaldehyde copolymer and a novolac type resorcin / formaldehyde copolymer, which are adjusted at different aging times, are included.

  When a resole-type resorcin / formaldehyde copolymer and a novolac-type resorcin / formaldehyde copolymer are used in the present invention, a solid of a novolac-type resorcin / formaldehyde copolymer (A) and a resole-type resorcin / formaldehyde copolymer (B) The mass ratio A / B is preferably in the range of A / B = 1/1 to 1/5. When it is in the above range, particularly excellent adhesive force is obtained, and the process passability is particularly excellent.

  In the present invention, when a combination of resorcin-formaldehyde copolymers having the same composition and different ripening degrees is used, it is preferable to make a difference in the aging time, for example. More preferably, there is a difference in aging time of 2 hours or more between an RF condensate having a high aging degree and an RF condensate having a low aging degree. By making the difference in the aging time longer than 2 hours, the adhesiveness is further improved.

  Further, in the case of combining a resol-type solcin / formaldehyde copolymer and a novolac-type cosolsin / formaldehyde polymer, it is preferable to make a difference in the aging time when ripening each. In particular, it is preferable that the aging time of the resol type solcin / formaldehyde copolymer is shorter because the adhesive force is further improved.

  The rubber latex used in resorcin / formaldehyde / rubber latex is not particularly limited, but examples include natural rubber latex, styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, polybutadiene rubber latex, chloroprene rubber latex, vinylpyridine. -Styrene-butadiene rubber latex, and ethylene-propylene-nonconjugated diene terpolymer rubber latex, among others, chloroprene rubber latex, vinylpyridine-styrene-butadiene rubber latex, polybutadiene rubber latex, styrene-butadiene Rubber latex and the like are preferable. These rubber latexes can be used alone or in combination.

  In this invention, it is a preferable aspect to use 30 mass% or more of chloroprene rubber latex among solid content of the whole latex from a viewpoint of process permeability. As the latex to be combined, styrene-butadiene rubber latex, vinylpyridine-styrene-butadiene rubber latex, polybutadiene rubber latex, ethylene-propylene-nonconjugated diene terpolymer rubber latex and the like are preferable from the viewpoint of improving adhesiveness. Vinyl pyridine-styrene-butadiene rubber latex, polybutadiene rubber latex, styrene-butadiene rubber latex and the like are preferable.

  In these latexes, carboxyl groups may be introduced for improving various properties such as stability. The carboxyl group can be introduced into the rubber latex by copolymerizing an ethylenically unsaturated ester monomer or an ethylenically unsaturated acid anhydride monomer and then hydrolyzing it. In this case, ethylenically unsaturated acid ester monomers and ethylenically unsaturated acid anhydride monomers include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, fumaric acid, maleic acid and butenetricarboxylic acid. Examples include monoesters, diesters and triesters of unsaturated carboxylic acids such as acids, and maleic anhydride, and one or more of these are used.

  Furthermore, the blending ratio of resorcin / formaldehyde / rubber latex resorcin / formaldehyde (RF) and rubber latex (L) is preferably RF / L = 1/3 to 1/15 in terms of solid content. Preferably it is 1/5 to 1/12, and more preferably 1/7 to 1/10. If the RF / L ratio is out of this range, the adhesiveness may decrease or the process passability may deteriorate.

  Moreover, it is preferable that the ripening conditions of RFL are 14 to 35 hours on the conditions of 20-30 degreeC, More preferably, it is 16 to 30 hours. If the aging condition is out of this range, the adhesiveness may be lowered.

  In addition, the adhesive used in the present invention includes an adhesion aid such as isocyanate, blocked polyisocyanate, ethylene urea compound, halogenated phenol derivative, and carbon black, a filler, a crosslinking agent, and the like, from the viewpoint of improving adhesiveness. Vulcanizing agents, vulcanization accelerators, and the like can be mixed. These mixtures are preferably mixed within a range where the total does not exceed 30% by mass with respect to 100% by mass of the total solid content of the adhesive. When the mixing ratio exceeds 30% by mass, the adhesive force may be reduced, the process passability may be deteriorated, or the cord may be hardened.

  The fiber to which the fiber / rubber adhesive obtained in the present invention is applied is not particularly limited, and examples thereof include cotton, rayon, polyester, polyamide, and aramid. When using a fiber having low reactivity with an adhesive such as polyester or aramid, it is desirable to pre-treat. The pretreatment may be an ordinary method, and preferred specific examples include treatment with a polyepoxide compound or a blocked isocyanate compound.

  In order to apply the adhesive used in the present invention to the fibers, any method such as dipping, nozzle spraying, and application with a roller can be employed. For this reason, it can process, for example using a Ritular computer treater or a multi-cylinder type code setter machine.

  In the present invention, the organic fiber cord is impregnated with the adhesive composition and then heat-treated, and the heat treatment temperature at this time is a viewpoint of effectively imparting adhesiveness to the organic fiber cord. From 210 to 265 ° C is preferable, and from 235 to 255 ° C is more preferable.

  Moreover, the adhesion amount of the adhesive composition with respect to the organic fiber cord (increased mass by the adhesive composition based on the mass of the impregnated cord after drying) is 0.5 to 5.0% by mass. preferable.

  Next, the fiber / rubber adhesive of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

  Moreover, the measuring method and evaluation method of each characteristic value in the examples are as follows.

<Evaluation method>
(1) Cords were arranged in parallel on an EPDM rubber sheet (5 mm thickness) having the composition shown in Table 1 (36 driven / 2.54 cm driven) and press vulcanized (150 ° C., 30 minutes) , Rubber and cord surface pressure of 300 N / cm ² ). After being allowed to cool, a peel test was performed in which the cord was peeled from the rubber at a speed of 50 mm / min in an environment of 20 ° C. The force required for peeling at this time was displayed as N / 2.54 cm.

(2) Treatment agent adhesion amount:
It was determined by the mass method of JIS L1017 (2002) 8.15 b).

(3) Process passability:
The fiber cord was run on a friction tester manufactured by Toray Engineering Co., Ltd. shown in FIG. 1, and the adhesion state of the RFL residue to the guides was used as an index. FIG. 1 is a schematic diagram showing a friction tester for evaluating the processability of fiber cords. A fiber cord is taken out from the fiber cord sample 1 for measurement, passed through a nip roller 2 for feeding a yarn, applied with a load 3 and partially wound around the surface of the satin chrome-plated tube 4 to feed the nip roller for feeding the yarn. 5 and the amount of RFL adhering to the nip rollers 2 and 5 for feeding the yarn was measured. An extremely small amount of debris generation was indicated as ◎, a small amount of debris was indicated as ◯, a large amount of debris was indicated as ×, and any case where it was difficult to determine was indicated as △. In the present invention, ◎, ○, and △ are regarded as acceptable passing points of process that can withstand practical use. However, ◎ is practically superior.

Example 1
A resorcin / formaldehyde initial condensate: “SUMIKANOL” 700 (S) (registered trademark) (manufactured by Sumitomo Chemical Co., Ltd., 65% aqueous solution) is added to the aqueous caustic soda solution and sufficiently stirred and dispersed therein. (F) was added so as to have an R / F ratio of 1/2 (molar ratio), mixed uniformly, and aged for 5 hours at a temperature of 25 ° C. (referred to as RF-1 solution). In addition, resorcin (R) is sufficiently stirred and dispersed, to which formaldehyde (F) is added so that the R / F ratio is 1 / 1.5 (molar ratio), and mixed uniformly. Aged at 25 ° C. for 2 hours (referred to as RF-2 solution) Next, a mixture of RF-1 solution and RF-2 solution was mixed with chloroprene rubber latex (“Showprene” (registered trademark) 650 (Showa Denko). (Made by) and vinyl A mixture of pyridine-styrene-butadiene rubber latex (“Nippol” (registered trademark) 2518FS (manufactured by Nippon Zeon Co., Ltd.)) (chloroprene rubber latex / vinylpyridine-styrene-butadiene rubber latex = 50/50 (solid weight ratio) )) Was mixed with the aforementioned resorcin / formaldehyde initial condensate mixture at a solid content ratio (RF / L ratio) of 1/9, sufficiently stirred and aged at a temperature of 25 ° C. for 20 hours. The treatment liquid concentration was 10%.

  On the other hand, one multifilament made of polyester fiber (T707C (1100 dTex) manufactured by Toray Industries, Inc., 10 t / 10 cm) previously provided with a polyepoxide compound (sorbitol polyglycidyl ether) by a method of mixing a polyepoxide compound as a spinning oil agent in a spinning process. A twisted cord was obtained.

  The cord is dipped in the adhesive using a computer treater processor (CA Ritzler Co., Ltd., tire cord processor), and then dried at a temperature of 120 ° C. under a stretch condition of 0% for 2 minutes. Heat treatment was performed at 240 ° C. for 1 minute under a stretch condition of 1%, followed by heat treatment at 240 ° C. for 1 minute while giving 2% relaxation (total stretch ratio—1%). The cord had 2.3% by mass of the solid content of the treatment agent. The cord thus obtained was measured for cord peeling adhesion and process passability as described above. The results are shown in Table 2.

(Examples 2-9)
In Example 1, except that the latex used, the RF species, the aging time, and the RF-1 / RF-2 ratio were changed as shown in Table 2, the treatment was performed under the same conditions as in Example 1, and evaluation was performed in the same manner. did. The evaluation results are also shown in Table 2.

(Comparative Examples 1-2)
In Example 1, except that the used latex, the RF species, and the aging time were changed as shown in Table 2, the treatment was performed under the same conditions as in Example 1, and evaluation was performed in the same manner. The evaluation results are also shown in Table 2. Comparative Examples 1 and 2 are adhesives that did not use two or more different resorcin / formaldehyde copolymers.

The latex used in Examples 1 to 7 and Comparative Examples 1 and 2 is as follows.
CR latex: “Showprene” (registered trademark) CR650: Chloroprene rubber latex (manufactured by Showa Denko KK)
-VP latex: "Nippol" (registered trademark) 2518FS: vinyl pyridine, styrene, butadiene rubber latex (manufactured by Nippon Zeon)
SBR latex: “Nippol” (registered trademark) LX110: Styrene-butadiene rubber latex (manufactured by Nippon Zeon Co., Ltd.)
From the evaluation results shown in Table 2, it can be seen that the fiber / rubber adhesive according to the present invention has good adhesiveness and good process passability.

1: Fiber cord sample for measurement 2: Nip roller for yarn feeding 3: Load 4: Satin chrome plated tube 5: Nip roller for yarn feeding

Claims (6)

Fiber / rubber adhesive containing resorcin / formaldehyde copolymer and rubber latex, which is made by adding two or more resorcin / formaldehyde copolymers to resorcin / formaldehyde copolymer adhesive The two or more kinds of resorcin-formaldehyde copolymers include a combination of resorcin-formaldehyde copolymers and / or resorcin-formaldehyde copolymers having different compositions at the same composition and different maturity levels. Adhesive for fiber and rubber The fiber / rubber adhesive according to claim 1 or 2, wherein the two or more types of resorcin / formaldehyde copolymer include a resole type resorcin / formaldehyde copolymer and a novolac type resorcin / formaldehyde copolymer. The mass ratio [A / B] of the novolac-type resorcin / formaldehyde copolymer (A) to the resole-type resorcin / formaldehyde copolymer (B) is A / B = 1/1 to 1/5. Fiber / rubber adhesives as described The fiber / rubber adhesive according to any one of claims 1 to 4, wherein the rubber latex contains 30% by mass or more of chloroprene latex in the solid content of the entire rubber latex. A method for producing a fiber / rubber adhesive comprising mixing two or more types of resorcin / formaldehyde copolymer when producing a fiber / rubber adhesive containing a resorcin / formaldehyde copolymer and a rubber latex.

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