JP2000034455A - Adhesive composition, rubber reinforcing organic fiber and pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an adhesive composition capable of well bonding a polyester material and the like to a rubber and excellent in heat-resisting adhesion, to provide method for preparing the same, and to obtain a rubber reinforcing organic fibers using the adhesive composition and a pneumatic tire using cords composed of the rubber reinforcing organic fibers as the reinforcing material of tires. SOLUTION: Adhesive composition comprises (A) a phenolic condensation product which is a sulfomethylated product or sulfimethylated product of a condensation product of a phenol having a methylol group with an aldehyde or an aldehyde donor; (B) a rubber latex; and (C) a resorcinol-formaldehyde condensation product at a weight ratio of solids content of component (A) to component (B) plus component (C) within the range of 5/100-85/100 and, at the same time, at a weight ratio of solids content of component (C) to component (B) within the range of 5/100-30/100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition and the like, and more particularly, to an adhesive composition capable of satisfactorily bonding a polyester material or the like to rubber, a method for producing the same, and the adhesive composition. The present invention relates to a rubber reinforcing organic fiber using the same, and a pneumatic tire using a cord made of the rubber reinforcing organic fiber as a tire reinforcing material.

[0002]

2. Description of the Related Art In general, a polyester material, which is a linear polymer having an ester bond in a main chain, represented by polyethylene terephthalate, is one of general-purpose polymer materials having high initial elastic modulus and excellent Reinforcement of rubber articles such as tires, belts, air springs, rubber hoses, etc. in the form of filaments, cords, cables, cord fabrics, canvas, etc. because they have dimensional stability when heated and are also excellent in cost. It is extremely useful as a material.

However, when a polyester material is used as a reinforcing material for these rubber articles, the polyester material has a dense molecular structure and a small number of functional groups. It is usually difficult to use a so-called RFL solution (a composition comprising a resorcinol-formaldehyde condensate obtained by a resolation reaction and a rubber latex) for adhering a material such as nylon or rayon to rubber. However, the polyester material and the like could hardly be bonded to rubber.

[0004] For this reason, in the past, for example, the surface of a polyester cord was treated with an alkali or an amine, and the surface was treated with -O.
H, -COOH, a method of increasing the active group such as -NH ₂ (e.g., JP-B 46-41087 Patent JP) and an isocyanate compound, hydrogen bonding ability to a polyester cord surface by an epoxy compound or primary linkable functional groups A method of introducing a compound having the following formula, followed by treatment with an adhesive solution, and an adhesive composition (for example, JP-B-46-41).
No. 087) have been proposed. However, the former alkali-amine treatment has a problem of deteriorating the strength of the polyester cord. In the latter treatment with an isocyanate compound or epoxy compound, it has been pointed out that these compounds are scattered in the air during bonding, smoke generated during heat treatment, and harmful to the human body due to steam, and the like. This is also undesirable.

[0005] Further, the adhesive composition for polyester includes:
Numerous adhesive compositions have been proposed in which a condensate of a phenol and an aldehyde (phenol / aldehyde condensate) that imparts adhesion / tackiness to the RFL solution is added as an adhesion promoter. Since this adhesive composition can be bonded and processed in a one-part form, it is excellent in energy and cost.

As a resin for imparting adhesion / tackiness to be added to these one-part adhesive compositions, many phenol-aldehyde condensates obtained by a novolak reaction have been proposed. -Condensates of chlorophenol and formaldehyde (U.S. Pat. No. 4,376,854), formaldehyde co-condensates of m-cresol and m-aminophenol (JP-A-8-26421),
Resorcin-formaldehyde condensate obtained by a novolak reaction (Republished patent WO 97/13818)
No. 4), Alkylace, a polyhydric phenol mixture obtained by dry distillation of an Estonian oil shale (US Pat.
No. 76,854), p-cresol / formaldehyde condensate (U.S. Pat.No.4,376,854), 3,5-xylenol / formaldehyde condensate (U.S. Pat.No.4,376,854), m-methoxyphenol / formaldehyde condensate (U.S. Pat. No. 4,376,854), 5-methylresorcinol-formaldehyde condensate, and the like have been proposed.

The polyester adhesive composition obtained by mixing the phenol / aldehyde condensate-based adhesion / tackiness-imparting resin obtained by the novolak reaction and the RFL liquid is a phenol / aldehyde compound obtained by the novolak reaction.
In general, a method is used in which an aldehyde condensate-based adhesion / tackifying resin is dispersed or dissolved in water and then added to an RFL solution. The reason for this is that the RFL liquid is a system in which rubber latex or the like is dispersed in water.

Further, as the above-mentioned adhesive / tackifying resin, R
The phenol / aldehyde condensate added to the FL solution is
It is desirable to have a property of being soluble in water in all ranges from acidic to alkaline conditions for the following reasons (1) and (2).

(1) First, phenols that do not dissolve in water
In the case of an aldehyde condensate, a method of dispersing the resin with a surfactant or the like is known, but since the resin for imparting adhesion / tackiness is not uniformly dispersed at the molecular level in the adhesive composition, sufficient adhesion / tackiness is obtained. It is difficult to obtain the effect of imparting such a property, and it is not preferable for stable and sufficient performance of rubber articles such as tires and belts that require heat-resistant adhesion. Also, the addition of a surfactant is not preferable because it generally tends to lower the adhesive strength, particularly the heat-resistant adhesive strength.

(2) In the case of dissolving a phenol / aldehyde condensate in water, generally, an alkali such as ammonia or sodium hydroxide is added.
The reason for this is that phenols such as phenol / aldehyde condensates have low water solubility in a neutral pH range. The RFL solution is obtained with a basic pH of 8.0 or more so that the resorcinol-formaldehyde condensation reaction during aging is sufficiently performed. When a phenol such as a phenol / aldehyde condensate is added to the RFL solution, the phenol / aldehyde condensate is acidic when dissolved in water, but increases in pH when mixed with the RFL solution. When the pH is in the neutral range, precipitation occurs in the case of a phenol / aldehyde condensate having no self-solubility. Therefore, in order to prevent this precipitation, at present, an alkali is previously added to the phenol / aldehyde condensate.

However, the addition of alkali to the adhesive composition has a problem that the adhesive strength is reduced. For example, RF
It is known that increasing the amount of alkali in the adhesive composition composed of L causes a decrease in adhesion (Journal of the Adhesion Society of Japan, Vol. 8 No. 1 (1972)). The reason is that in the vulcanization step for bonding and forming a rubber article, sulfur migrates from the rubber to the adhesive composition and undergoes a cross-linking reaction with the rubber latex component, but when the alkali of the adhesive composition increases, vulcanization occurs. This is because the sulfuric acid reaction is accelerated, and the adhesive layer is over-vulcanized under heating for a long time, so that the adhesive strength is reduced (see WO97 / WO97 / 93).
13818).

Furthermore, the water solubility of the phenol / aldehyde condensate differs depending on the water solubility of the phenol raw material to be condensed and the degree of condensation of the phenol / aldehyde condensate. For example, a phenol / aldehyde condensate having a structure in which one OH group is present on the phenol ring in the molecule.
-A formaldehyde co-condensate of cresol and m-aminophenol (JP-A-8-269421) in which 4 to 7 phenols are co-condensed with formaldehyde is a formaldehyde co-condensate of m-cresol and m-aminophenol. 100 g of dry weight of condensate and 40 of water
6 g of sodium hydroxide is required for 0 g (precipitation of an insoluble component occurred at a solution pH of 10.3). Among the phenol-aldehyde condensates, the phenols in the molecule have two OH groups and 2 to 5 phenols are condensed with formaldehyde. Object (the above-mentioned WO97
/ 13818), at a molecular weight at which an adhesion / tackiness-imparting effect can be obtained, at least 0.1 g of sodium hydroxide per 100 g of dry weight of resorcinol-formaldehyde condensate and 400 g of water (insoluble precipitates are formed at a solution pH of 5.3). Was)
is necessary.

Accordingly, phenols having a water solubility equal to or lower than that of resorcinol, such as phenol, alkylphenol, m-methoxyphenol, halophenol, aminophenol, nitrophenol, resorcinol and alkylresorcinol, are used as raw materials for the phenol / aldehyde condensate. When used, the phenol / aldehyde condensate precipitates at any pH in the range of pH 5.3 to pH 10, since the water solubility is lower than that of the resorcin-formaldehyde condensate. For this reason,
Alkali addition was required. In addition, even after mixing with RFL, the pH of the adhesive composition solution was adjusted to pH 5.0 to pH 5.0.
If it is 8.0, these phenols / aldehyde condensates are precipitated, and there is a problem that the adhesive composition is gelled.

Due to the reasons (1) and (2), the phenol / aldehyde condensate used as the adhesion / tackifying resin has a pH in the range of acidic to alkaline conditions with respect to water.
It is preferable that the adhesive has a self-dissolving property, and it is required to suppress a decrease in heat-resistant adhesive strength. To develop an adhesive composition suitable for a polyester material for rubber reinforcement is an important technical problem at present. .

In the method of sulfomethylating a phenol / aldehyde condensate, a water-soluble inorganic sulfurous acid is added to a resole-type phenol resin and reacted to introduce a sulfomethyl group, thereby improving the solubility of the compound. Condensates have been provided which maintain water solubility in the pH range of 1 to 10.5 in the presence of some hydrophilic organic solvents such as alcohols (US Pat. No. 2,537,798). Further, a co-condensate of a monohydric phenol-aldehyde condensate having a methylol group and a polyhydric phenol and / or a polyhydric phenol-aldehyde initial condensate has a sulfomethyl group (Japanese Patent Application Laid-Open No. 7-53652) or a sulfimethyl group (Japanese Unexamined Patent Publication No. 9-12658), a phenol-based condensate having increased water solubility even on the acidic side is provided. In the techniques described in these publications, a catalyst is added to a sulfomethylated or sulfimethylated phenol / aldehyde condensate, and an adhesive is formed by reaction curing. In this reaction curing, a sulfomethyl group or a sulfimethyl group delays curing. It is reported that various effects can be obtained.

However, according to these reports, sulfomethylated or sulfimethylated phenol / aldehyde condensates are phenol / aldehyde with improved water solubility.
When mixed with an RFL solution as an adhesion / tackiness-imparting resin to become an aldehyde condensate, the effect of improving the heat-resistant adhesion by reducing the amount of alkali added has not been specifically studied. is there.

Therefore, as described above, in a one-part adhesive composition suitable for a polyester material for reinforcing rubber, a phenol / aldehyde condensate for imparting adhesion / tackiness precipitates at around pH neutral. Easily, and to prevent this precipitation, when an alkali is added to the adhesive composition, the adhesive strength,
In particular, there is a problem that the heat-resistant adhesive strength is reduced, and an organic fiber for reinforcing rubber using an adhesive composition whose heat-resistant adhesive strength is reduced, and further, the organic fiber for reinforcing rubber is used as a tire reinforcing material. The pneumatic tire has a problem that it becomes insufficient in durability and the like.

[0018]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is intended to solve the above-mentioned problem. The present invention also provides an adhesive composition excellent in the above, a method for producing the same, a rubber reinforcing organic fiber using the adhesive composition, and a pneumatic tire using a cord made of the rubber reinforcing organic fiber as a tire reinforcing material. The purpose is to do.

[0019]

The inventor of the present invention has conducted various studies on the deterioration of the adhesion between a reinforcing material and its coating rubber composition (hereinafter referred to as rubber to be adhered) due to thermal stimulation. When a specific phenol-aldehyde condensate containing a sulfomethyl group or a sulfimethyl group which is self-dissolving in water in a neutral pH range of 4.5 to pH 8.0 is used as the adhesion / tackiness imparting agent contained together with the RFL solution, Conventionally, since the alkali added to prevent precipitation near neutrality can be removed, the adhesive composition of the above object capable of suppressing a decrease in heat-resistant adhesive strength, a production method thereof, an organic fiber for rubber reinforcement, and a pneumatic composition The tire was successfully obtained, and the present invention was completed.

That is, the present invention resides in the following (1) to (11). (1) A phenolic condensate comprising a sulfomethylated product or a sulfimethylated product of a condensate of a phenol having a methylol group with an aldehyde or an aldehyde donor (A)
And a rubber latex (B) and a resorcinol-formaldehyde condensate (C), and the ratio of the A component / (B component + C component) is in the range of 5/100 to 85/100 in terms of solid content weight ratio. An adhesive composition wherein the ratio of component C / component B is in the range of 5/100 to 30/100 in terms of solid content weight ratio. (2) The pH condition for dissolving 100 g by dry weight of the phenolic condensate (A) in 400 g of water is p
The adhesive composition according to the above (1), which is soluble in water in the range of H4.5 to 8.0. (3) The adhesive composition according to the above (1) or (2), wherein the pH is adjusted with sodium hydroxide. (4) The above (1) to (3) wherein the pH is in the range of 5.0 to 8.0.
The adhesive composition according to any one of the above. (5) The resorcinol-formaldehyde condensate (C)
Is the adhesive composition according to any one of the above (1) to (4), which is obtained by performing a condensation reaction under the mixing of rubber latex. (6) The phenolic condensate (A) is obtained by a condensation reaction under the mixing of the rubber latex.
The adhesive composition according to any one of (1) to (5). (7) The phenol for obtaining the phenol condensate (A) is at least one selected from phenol, alkylphenol, m-methoxyphenol, halophenol, aminophenol, nitrophenol, resorcin, and alkylresorcin. The adhesive composition according to any one of the above (1) to (6). (8) An organic fiber for rubber reinforcement, which has been subjected to an adhesive treatment with the adhesive composition according to any one of the above (1) to (7). (9) A pneumatic tire using the cord comprising the organic fiber for rubber reinforcement described in (8) above as a reinforcing material for a pneumatic tire. (10) The method for producing an adhesive composition according to any one of (1) to (7) above, wherein the phenolic condensate (A) is a condensation reaction or a cocondensation reaction of a phenol with an aldehyde. A method for producing an adhesive composition, comprising adding and reacting a sulfomethylating agent and / or a sulfimethylating agent before, during, or after the reaction. (11) The resorcinol-formaldehyde condensate (C) is
The method for producing an adhesive composition according to claim 10, which is obtained by performing a condensation reaction under the mixing of rubber latex.

[0021]

Embodiments of the present invention will be described below in detail. The adhesive composition of the present invention comprises a phenolic condensate (A), which is a sulfomethylated or sulfimethylated condensate of a phenol having a methylol group and an aldehyde or an aldehyde donor; a rubber latex (B); Formaldehyde condensate (C)
Wherein the ratio of component A / (component B + component C) is in the range of 5/100 to 85/100 in terms of solids weight ratio, and the ratio of component C / component B is the weight of solids. 5/100 in ratio
3030/100. The adhesive composition is prepared by using the rubber latex (B)
And the raw material of the resorcinol-formaldehyde condensate (C) mixed by a specific method or the like, and aged to obtain an RF
It can be obtained by mixing the above-mentioned sulfomethylated or sulfimethylated phenol / aldehyde condensate (A) with the L liquid as an adhesion / tackifier.

The phenols used in the adhesive composition of the present invention include, for example, phenol, o-cresol, m
-Cresol, p-cresol, ethylphenol, i
alkylphenols such as so-propylphenol, xylenol, 3,5-xylenol, butylphenol, t-butylphenol, nonylphenol, o-fluorophenol, m-fluorophenol, p-fluorophenol, o-chlorophenol, m-chlorophenol, p -Chlorophenol, o-bromophenol, m-bromophenol, p-bromophenol, o
Halophenols such as iodophenol, m-iodophenol and p-iodophenol, aminophenols such as o-aminophenol, m-aminophenol and p-aminophenol, o-nitrophenol, m-nitrophenol and p-nitro Phenol, nitrophenol such as 2,4-dinitrophenol, m-methoxyphenol, resorcinol, 5-methylresorcinol, 5-ethylresorcinol, 5-propylresorcinol, 5-n-butylresorcinol, 4,5-dimethylresorcinol, , 5-dimethylresorcinol, 4,5-diethylresorcinol, 2,5
-Diethylresorcin, 4,5-dipropylresorcin, 2,5-dipropylresorcin, 4-methyl-5-
Ethyl resorcinol, 2-methyl-5-ethyl resorcinol, 2-methyl-5-propyl resorcinol, 2,4,5
Raw materials containing a large amount of alkyl resorcinol, such as alkyl resorcinol such as -trimethyl resorcinol and 2,4,5-triethyl resorcinol, and alkylase of polyhydric phenol mixture obtained by dry distillation of Estonia oil shale. Preferred are the above various resorcinols having high water solubility.

In the adhesive composition of the present invention, the aldehyde and / or aldehyde donor used for producing the phenol / aldehyde condensate includes, for example, formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxyaldehyde, and the like. Methylene, chloral, hexamethylenetetramine, furfural, glyoxal, n-butyraldehyde, caproaldehyde, allylaldehyde, benzaldehyde, crotonaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde and the like. These can be used alone or as a mixture of two or more. Preferably, it is formaldehyde or hexamethylenetetramine.

The sulfomethylating agent used in the adhesive composition of the present invention includes, for example, sulfurous acid, bisulfite or metabisulfite and an alkali metal or a quaternary amine or quaternary ammonium such as trimethylamine or benzyltrimethylammonium. And water-soluble sulfites, and hydroxyalkane sulfonates such as hydroxymethane sulfonate. Preferably, it is sodium sulfite.

Examples of the sulfimethylating agent used in the adhesive composition of the present invention include alkali metal sulfoxylates of aliphatic and aromatic aldehydes such as formaldehyde sodium sulfoxylate (Rongalit) and benzaldehyde sodium xylate. Examples thereof include alkali metal and alkaline earth metal hydrosulfites such as sodium hydrosulfite and magnesium hydrosulfite, alkyl sulfoxylates such as sodium ethyl sulfoxylate, and hydroxyalkane sulfinates. Preferably, it is Rongalit.

In the adhesive composition of the present invention, the phenolic condensate (A) comprising a sulfomethylated product or a sulfimethylated product of a phenol / aldehyde condensate having a methylol group is used as the phenolic condensate described above. In producing a phenol / aldehyde condensate by condensing an aldehyde and / or an aldehyde donor with the sulfomethylating agent and / or during or after the condensation reaction or the cocondensation reaction,
Alternatively, it can be obtained by adding and reacting a sulfimethylating agent.

In the production of the phenolic condensate (A), a solvent, a complexing agent and other components are added, if necessary, to 1 mol of phenols and 1 to 2 mol of aldehyde and / or aldehyde donor. The mixture is reacted by heating at １００100 ° C. for 2 to 20 hours to obtain a phenol / aldehyde condensate having a methylol group. At this time, the aldehyde and / or the aldehyde donor may be added in its entirety at the start of the reaction,
It may be added in portions or dropped continuously. The condensation reaction,
The catalyst and pH conditions differ depending on the phenol to be condensed. That is, when the reaction is carried out under alkaline pH conditions, an alkali compound is used. For example, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide, sodium carbonate, lime, sodium sulfite, potassium sulfite, lithium sulfite, acetic acid Alkali metals such as sodium and sodium phosphate, hydroxides such as alkaline earth metals, oxides, carbonates, acetates, salts such as phosphates, ammonia, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanol Amines such as amine, hexamethylenetetramine, pyridine and the like are used. The amount of the alkali compound to be added is usually 6% or less based on the weight of the phenol. Also, to adjust to neutral or acidic,
For example, hydrochloric acid, boric acid, oxalic acid, acetic acid, lactic acid, butyric acid, paratoluenesulfonic acid, phenolsulfonic acid, benzenesulfonic acid, naphthalene-α-sulfonic acid, naphthalene-
Inorganic or organic acids such as β-sulfonic acid or esters of organic acids such as dimethyl oxalate, acid anhydrides such as maleic anhydride, and acidic compounds such as ammonium salts such as ammonium chloride, ammonium sulfate, ammonium nitrate and ammonium oxalate. Is used.

In the above-mentioned sulfomethylation or sulfimethylation, in the condensation of a phenol with an aldehyde and / or an aldehyde donor, the above-mentioned sulfomethylating agent is added before, during or after the reaction to cause a heating reaction. In this manner, a part of the methylol group of the phenol / aldehyde condensate reacts with the sulfomethylating agent or the sulfimethylating agent to form a sulfomethyl group or a sulfimethyl group, and the phenolic condensate (A) of the present invention is formed. Manufactured.

The amount of the sulfomethylating agent or sulfimethylating agent to be added is usually 0.001 to 0.8 mol per 1 mol of the monohydric phenol, but is preferably 0.01 to 0.8 mol.
It is about 1 to 0.8 mol. The reason for this is that if the addition amount is less than 0.001 mol, the effect of improving phenol / aldehyde condensate by sulfomethylation or sulfimethylation cannot be obtained, and if it exceeds 0.8 mol, sulfomethylation or sulfimethylation occurs. This is because the phenol / aldehyde condensate is too acidic, and when mixed with the RFL solution, the solution may gel due to pH shock.

Examples of the rubber latex (B) used in the adhesive composition of the present invention include vinyl pyridine-styrene-conjugated diene compound latex and modified latex such as carboxy-modified thereof, styrene-butadiene latex and modified latex thereof, Natural rubber latex, acrylate copolymer latex, butyl rubber latex, chloroprene latex, and the like can be used alone or in combination of two or more. Preferably, a monomer mixture composed of 5 to 60% by weight of butadiene, 5 to 15% by weight of vinylpyridine and 35 to 80% by weight of styrene, and 45 to 75% of butadiene.
% By weight, 5 to 20% by weight of vinylpyridine and styrene 1
A vinylpyridine-butadiene-based copolymer latex (hereinafter referred to as nVp latex) having copolymers having different composition ratios in the same particle obtained by subjecting a monomer mixture composed of 0 to 40% by weight to a division polymerization. (Abbreviated) (JP-A-9-111213).

The resorcinol-formaldehyde condensate (C) used in the adhesive composition of the present invention is obtained by reacting resorcinol and formalin or a relatively low molecular weight resorcinol-formaldehyde condensate with formaldehyde by a so-called resole reaction. It is a reaction product obtained. This condensate (C) may contain a phenol derivative other than resorcin as a third component. Preferably, it is a condensate of resorcinol and formaldehyde.

The adhesive composition of the present invention comprises an RFL obtained by mixing the rubber latex (B) and the raw materials of the resorcinol-formaldehyde condensate (C), followed by aging.
It is obtained by mixing the above-mentioned sulfomethylated or sulfimethylated phenol / aldehyde condensate (A) with an adhesive / tackifier. The sulfomethylated or sulfimethylated phenol-aldehyde condensate (A) can be mixed with the RFL solution by minimizing the amount of alkali added, preferably without adding alkali.

The resorcinol-formaldehyde condensate (C) obtained by the above resolving is preferably obtained by reacting with the rubber latex (B) under mixing.
This is because the rubbery tackiness of the adhesive composition can be reduced, and the occurrence of scale and gum up in the adhesion treatment step can be suppressed.

As a method of reacting the resorcin-formaldehyde condensate (C) obtained by the above resolving with mixing with a rubber latex (B), for example, a method of reacting a resorcin-formaldehyde condensate in an alkaline liquid is used. A method of mixing a raw material (resorcin, a relatively low molecular weight resorcin-formaldehyde condensate, formalin) with a latex, and a raw material of a resorcin-formaldehyde condensate under alkaline liquor without mixing with the latex at the start of the reaction To start the resolelation reaction, and a method in which a reaction intermediate having a low degree of condensation is mixed with latex as much as possible in the initial stage of the reaction to continue the reaction. Preferably, it is desirable to mix with the rubber latex before the condensation reaction of the resole-type resorcin-formaldehyde condensate is completed. This determination method, during the resolelation reaction, with the formation of methylol group of the reaction intermediate,
As the pH temporarily decreases, the methylol group is consumed as the condensation reaction proceeds, the pH rises again, and the pH is almost constant when the reaction is completed.The pH change can be determined as an index. The addition was performed using the pH change as an index.

The sulfomethylated or sulfimethylated phenol / aldehyde condensate (A) is
After dissolving in water, it is mixed with an aged RFL solution (the determination method is as described above). The reason for this is that RF
When the phenol-based condensate (A) is mixed with the liquid L, the resorcin-formaldehyde condensate (C), which has not yet been aged, reacts with the phenol-based condensate (A), and the phenol-based condensate (A) is reacted. This is because the adhesion promotion effect as an adhesion / tackifier cannot be obtained because the molecular weight is too high.

Here, in the adhesive composition of the present invention,
The reason that the rubber latex (B) and the resorcinol-formaldehyde condensate (C) have a C component / B component ratio of 5/100 to 30/100 in terms of solid content weight ratio is as follows.
If the amount of the resorcinol-formaldehyde condensate (C) is less than 5 parts by weight per 100 parts by weight, the RFL liquid has a high rubbery tackiness and is not preferable because scale is generated in the adhesion treatment step, and more than 30 parts by weight. When the adhesive composition becomes too hard, the adhesive composition becomes brittle against mechanical input after bonding, and the adhesive strength is easily reduced, which is not preferable. Preferably, the ratio of the component C / component B is 15
/ 100 to 25/100.

Further, in the adhesive composition of the present invention, RFL (component B) comprising a phenolic condensate (A) of an adhesive / tackifier, a rubber latex (B) and a resorcinol-formaldehyde condensate (C) + C component) and the ratio of A component / (B component + C component) is 5/1 in terms of solid content weight ratio.
The reason for being within the range of 00 to 85/100 is that if the phenolic condensate (A) is less than 5 parts by weight per 100 parts by weight of RFL (component B + C), the effect of imparting adhesion / tackiness is small, If the amount exceeds 85 parts by weight, the rubber latex component of the adhesive becomes too small, so that vulcanization crosslinking between the adhered rubber and the rubber latex decreases, and the adhesive strength decreases, which is not preferable. Preferably, the ratio of component A / (component B + component C) is 25/100 to 60/1 in terms of solid content weight ratio.
00 is within the range.

As a result of various studies on the phenol condensate (A), among the phenol / aldehyde condensates, the phenol in the molecule has a structure having two hydroxyl groups, and the phenol is formed by two phenols by formaldehyde.
A resorcin-formaldehyde condensate having a relatively good water solubility condensed from 5 to 5 (Example 3 of the above-mentioned WO97 / 13818), wherein sodium hydroxide is at least 0.1 g per 100 g of dry weight of resorcin-formaldehyde condensate and 400 g of water. g (precipitation of insolubles at solution pH 5.3)
However, this is dissolved in water until the sulfomethylated or sulfimethylated resorcin-formaldehyde condensate reaches pH 4.5 to pH 10.
Particularly, phenols and / or aldehydes comprising one or more of phenol, alkylphenol, m-methoxyphenol, halophenol, aminophenol, nitrophenol, resorcinol, and alkylresorcinol having lower water solubility than resorcinol are provided. The phenol / aldehyde condensate obtained by condensing the product is difficult to dissolve in water at pH 5.0 to pH 8.0, and it is preferable because the effect of improving sulfomethylation or sulfimethylation to improve water solubility is remarkably obtained. .

The phenol condensate (A) is
100 g of the dry weight of the phenolic condensate (A)
The pH condition for dissolving in 0 g is pH 4.5-8.
0, preferably in a condition range of pH 5.0 to 8.0. The reason for setting the pH to 4.5 to 8.0 is that
As described above, neutral and low water-soluble phenols and phenol / formaldehyde condensates are generally mixed with acidic phenols / formaldehyde condensates at a pH of 8.
This is because, when mixed with an RFL solution of 0 to 10.0, it precipitates neutrally, and when an alkali is used to prevent this precipitation, the heat-resistant adhesive strength decreases. The pH is measured by a method in which 400 g of water is mixed with 100 g of the dry weight of the phenolic condensate (A), and the pH is changed by changing the amount of sodium hydroxide (caustic soda) to be added. You.

The adhesive composition of the present invention comprises a phenolic condensate (A), a rubber latex (B) and a resorcinol-formaldehyde condensate (C). It is preferable that the pH is in the range of 5.0 to 8.0. The reason for this is that the p of the adhesive composition liquid
When H is less than 5.0, the electric repulsion between the dispersed particles dispersed in the adhesive liquid is too small, and the particles are likely to aggregate. The reason why the pH is preferably 8.0 or less is that the RFL solution condenses the resorcinol-formaldehyde condensate (C), so that it is usually alkaline when the pH exceeds 8.0, but when the pH is increased by adding an alkali compound, As described above, this is because the heat-resistant adhesive strength decreases. Therefore, a preferable method for preparing the adhesive composition liquid is to adjust the pH 4.5 to the RFL liquid to pH 4.5 or more.
A phenol-based condensate (A) of 8.0 is mixed to prepare an adhesive composition liquid having a pH of 5.0 to 8.0. At this time, the amount of alkali added is small, and the lower the pH, the better.

The adhesive composition of the present invention constituted as described above is prepared by mixing the rubber latex (B) and the raw materials of the resorcinol-formaldehyde condensate (C) together with an RFL solution obtained by aging. By containing the above-mentioned phenol-aldehyde condensate (A) containing a sulfomethyl group or a sulfimethyl group which is self-dissolving in water in a neutral pH range of 4.5 to 8.0 to the contained adhesion / tackiness imparting agent, Conventionally, since alkali added to prevent precipitation near neutrality can be removed, a decrease in heat-resistant adhesive strength can be suppressed, and this adhesive composition is used for tires, conveyor belts, belts, hoses, air springs. Etc. can be applied to all rubber products.

The form of the rubber reinforcing material (organic fiber for reinforcing rubber) to be bonded and processed with the above-mentioned adhesive composition in the present invention is not particularly limited, and may be any of a cord, a film, a short fiber and a nonwoven fabric. Hereinafter, a cord will be described as an example of the form of the reinforcing material. By bonding the adhesive composition of the present invention having the above structure to a polyester cord and performing an appropriate heat treatment, an adhesive-treated polyester cord [reinforcing material (organic fiber cord for rubber reinforcement) can be produced. By embedding and vulcanizing the cord thus obtained in unvulcanized rubber, the cord and the rubber can be firmly bonded.

Examples of the method of attaching the adhesive composition to the cord include a method of dipping the cord in the adhesive composition, a method of applying the adhesive composition with a brush, and a method of spraying the adhesive composition. However, an appropriate method can be selected as necessary. As the heat treatment performed after the drying, the glass transition temperature of the polymer of the cord or more, preferably the melting temperature of the polymer [−70 ° C.] or more, [melting temperature minus 20 ° C.]
It is preferred to apply at a temperature of less than. The reason for this is that if the temperature is lower than the glass transition temperature of the polymer, the molecular mobility of the polymer is poor, and the adhesive / tackifying resin of the adhesive composition cannot sufficiently interact with the polymer. This is because the bonding strength between the object and the cord cannot be obtained. Further, at a temperature exceeding the [melting temperature minus 20 ° C.] of the polymer, the rubber latex in the fiber material and the adhesive composition tends to deteriorate.

The adhesive composition of the present invention, in particular, can bond a polyester fiber material or the like to rubber satisfactorily, and this bonding effect is excellent as never before. In general, polyester is a polymer having an ester bond in the main chain, and more specifically, 80% or more of the bonding mode of the repeating unit in the main chain is of the ester bonding mode. Examples of the target polyester include, for example, ethylene glycol, propylene glycol, butylene glycol, methoxy polyethylene glycol, glycols such as pentaerythritol, and terephthalic acid, isophthalic acid, and esterification reaction of dicarboxylic acids such as dimethyl form thereof, Alternatively, a polyester obtained by condensing through a transesterification reaction may be mentioned, and the most typical polyester is polyethylene terephthalate (PET). As the polyester material that can be used in the present invention, for example, any form such as a cord, a cable, a filament, a filament chip, a cord fabric, and a canvas may be used. In addition, electron beam, microwave,
A pre-processed material such as corona discharge or plasma treatment may be used.

The adhesive composition of the present invention can be used in addition to the above-mentioned various polyester fiber materials and the like, as well as aliphatic polyamides such as rayon, vinylon, 6-nylon, 6,6-nylon and 4,6-nylon. It can be used for all materials represented by fibers, aromatic polyamide fibers represented by paraphenylene terephthalamide, carbon fibers and glass fibers.

Further, an epoxy compound or an isocyanate compound is used for polyester fiber, aromatic polyamide fiber,
The adhesive composition of the present invention also applies to the fiber-polymerization / spinning process represented by carbon fiber or the like, or to a post-processed fiber or a fiber material pre-processed by electron beam, microwave, plasma treatment, etc. Can be applied. code,
Any of a cable, a filament, a filament chip, a cord fabric, a canvas and the like may be used.

As described above, the form of the organic fiber for reinforcing rubber used as a reinforcing material for the rubber bonded and processed with the adhesive composition in the present invention is not particularly limited, and may be a cord, a cable, a film, a filament, or a filament. Any of a chip, a nonwoven fabric, a cord fabric, a canvas and the like may be used. Also, the obtained rubber reinforcing organic fiber has excellent heat-resistant adhesive strength,
When applied to rubber products such as pneumatic tires, conveyor belts, belts, hoses, etc., durability can be improved.

The pneumatic tire of the present invention is characterized in that a cord made of a rubber reinforcing organic fiber which has been subjected to an adhesive treatment with the above-mentioned adhesive composition is used as a reinforcing material of the pneumatic tire. Generally, a pneumatic tire includes a tread portion, a pair of side portions connected on both sides of the tread portion, and a pair of bead portions formed on an inner periphery of the side portion, respectively. And a carcass ply surrounding the carcass ply and a belt layer buried inside the tread portion and reinforced.

In the pneumatic tire of the present invention, a cord made of an organic fiber for reinforcing rubber which has been subjected to an adhesive treatment with the above-mentioned adhesive composition is used as a reinforcing material for the pneumatic tire, for example, a carcass ply cord, a belt cord and the like. Things. The pneumatic tire of the present invention is manufactured by a conventional method, and is different from the conventional pneumatic tire in that the carcass ply cord, the belt cord, and the like having the above-described structure are used as the reinforcing material. is there. In the pneumatic tire of the present invention, since a carcass ply cord, a belt cord, or the like having excellent heat-resistant adhesive strength is used as a reinforcing material, the durability can be further improved.

[0050]

Next, the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to the following examples. The solid content concentration in Examples and the like is determined by JI
The measurement was performed in accordance with the measurement of the non-volatile content of the adhesive in the method for measuring “other adhesives” specified in SK6833.

[Examples 1 and 2, Comparative Examples 1 and 2] (1) Preparation of Rubber Latex (B) The rubber latex used in Examples 1 and 2 and Comparative Examples 1 and 2 was obtained from WO 97/13818. Examples 1-4
The “nVp latex” used in No. 2 was used. (2) Preparation of composition (RFL solution) comprising rubber latex (B) and resorcinol-formaldehyde condensate (C), and a resorcinol-formaldehyde condensate having the composition shown below with the nVp latex obtained in (1) above A liquid obtained by mixing the raw materials of C) is mixed with the composition shown below, and the mixture is mixed at 25 ° C.
For 24 hours, and a composition comprising a rubber latex (B) and a resorcinol-formaldehyde condensate (C) (R
FL solution).

[Composition of resorcinol-formaldehyde condensate (C)] Water 520.6 parts by weight Resorcinol 14.5 parts by weight Formaldehyde (37%) 18.5 parts by weight Sodium hydroxide (10%) 1.6 parts by weight nVp Latex (40%) 435.9 parts by weight * Solid content in parentheses

(3) Preparation of phenolic condensate (A) The phenolic condensate (A) of Examples 1-2 and Comparative Examples 1-2 was prepared by measuring the solid content after condensation by the following method. If necessary, water was added to adjust the solid concentration to 50%. The pH was measured by mixing 400 g of water with 100 g of the dry weight of the phenolic condensate (A).
Further, it was measured by a method of changing the pH conditions by changing the amount of sodium hydroxide (caustic soda) to be added. (i) Example 1 A reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel was charged with 100 parts by weight of resorcin, 16.3 parts by weight of water, and 0.16 parts by weight of paratoluenesulfonic acid.
After dissolving at room temperature, 97.7 parts by weight of a 37% formalin solution was added dropwise over 0.5 hours while stirring at 110 ° C.
After stirring was continued for another 5.0 hours, sodium sulfite was added.
3 parts by weight were added, and the mixture was reacted at 90 ° C. for 2 hours with stirring to obtain a sulfomethylated phenolic condensate (A) of Example 1. Table 1 shows the pH range in which water is dissolved in water, which is measured by a method in which 400 g of water is mixed with 100 g of the dry weight of the condensate and the pH is changed by changing the amount of caustic soda to be added.

(Ii) Comparative Example 1 In a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel, 100 parts by weight of resorcinol, 16.3 parts by weight of water, and 0.16 parts by weight of paratoluenesulfonic acid. Preparation,
After dissolution at room temperature, 94.5 parts by weight of a 37% formalin solution was added dropwise with stirring at 110 ° C. over 0.5 hours,
After further stirring for 6.0 hours, the reaction was allowed to proceed at 90 ° C. for 2 hours with stirring without adding sodium sulfite to obtain a phenolic condensate (A) of Comparative Example 1. Table 1 shows the pH range in which water is dissolved in water, which is measured by a method in which 400 g of water is mixed with 100 g of the dry weight of the condensate and the pH is changed by changing the amount of caustic soda to be added.

(Iii) Example 2 100 parts by weight of m-cresol, 50 parts by weight of water, and 0.23 parts by weight of calcium hydroxide were charged into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel. , 60 ° C
97.7 parts by weight of a 37% formalin solution were added dropwise over 0.5 hours while stirring with, and the mixture was further stirred for 4.5 hours to carry out a resolation reaction, and then 106.5 parts by weight of m-aminophenol. After stirring at 100 ° C. for 2.0 hours, 6.3 parts by weight of Rongalite was added, and the mixture was reacted at 90 ° C. for 5 hours with stirring to obtain the sulfimethylated phenol condensate (A) of Example 2. Obtained. Table 1 shows the pH range in which water is dissolved in water, which is measured by a method in which 400 g of water is mixed with 100 g of the dry weight of the condensate and the pH is changed by changing the amount of caustic soda to be added.

(Iv) Comparative Example 2 In a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel, 100 parts by weight of resorcinol, 16.3 parts by weight of water, and 0.2 parts by weight of paratoluenesulfonic acid. After charging and dissolving at room temperature, 97.7 parts by weight of a 37% formalin solution was added dropwise over 0.5 hours while stirring at 110 ° C., and stirring was further continued for 2.0 hours, and then Rongalite was not added. The mixture was reacted at 90 ° C. for 5 hours with stirring to obtain a sulfimethylated phenol condensate (A) of Comparative Example 2. Table 1 shows the pH range in which water is dissolved in water, which is measured by a method in which 400 g of water is mixed with 100 g of the dry weight of the condensate and the pH is changed by changing the amount of caustic soda to be added.

(4) Preparation of Adhesive Composition The phenolic condensate (A) obtained in (i) to (iv) of (3) is dissolved in water or aqueous sodium hydroxide according to Table 1 below to promote adhesion. The solution was used. 76.9 parts by weight of the RFL liquid obtained in the above (2) was mixed with 23.1 parts by weight of the adhesion promoter liquid to obtain an adhesive composition. The pH of this adhesive was measured and is shown in Table 1.

(5) Preparation of Adhesive Composition-Treated Cord As a polyester material, a polyethylene terephthalate tire cord having a twist structure of 1500 d / 2, a number of twists of 40 times / 10 cm, and a number of lower twists of 40 times / 10 cm was used. ), And then immersed in the adhesive composition obtained at
After drying for 2 minutes, treatment was performed for 2 minutes in an atmosphere maintained at 240 ° C.

(6-1) Vulcanization I The adhesive composition treatment cord obtained in the above (5) was embedded in an unvulcanized rubber composition having the following composition, and was cured at 170 ° C. × 3.
Vulcanization was carried out under a pressure of 20 kg / cm2 for 0 minutes. [Blending composition] Natural rubber 80 parts by weight Styrene-butadiene copolymer rubber 20 parts by weight Carbon black 40 parts by weight Stearic acid 2 parts by weight Petroleum softener 10 parts by weight Baintal 4 parts by weight Zinc white 5 parts by weight N-phenyl-β- Naphthylamine 1.5 parts by weight 2-benzothiazyl disulfide 0.75 parts by weight Diphenylguanidine 0.75 parts by weight Sulfur 2.5 parts by weight

(6-2) Measurement of initial adhesive strength A cord was dug up from the vulcanizate obtained in (6-1) above,
The resistance at the time of peeling the cord from the vulcanizate at a speed of cm / min was measured, and this was defined as the initial adhesive strength. The results are shown in Table 1 below.

(7-1) Vulcanization II The adhesive composition treatment cord obtained in the above (5) was embedded in the unvulcanized rubber composition having the above-mentioned composition, and was heated at 190 ° C. for 30 minutes.
Vulcanization was performed under a pressure of 0 kg / cm2. (7-2) Measurement of heat-resistant adhesive strength A cord is excavated from the vulcanizate obtained in (7-1) above, and the cord is peeled off from the vulcanizate at a speed of 30 cm / min in the same manner as described above. The drag was measured and this was defined as the heat-resistant adhesive strength.
The results are shown in Table 1 below.

(8) Tire Durability A radial tire for passenger cars having a size of 185/70 R14 was manufactured using the treatment cord obtained in (5) above and one layer as a carcass ply. For the manufactured tire, a rim is assembled by the method of 5.3.1 of JIS D 4230, and the test apparatus of 5.3.2 is used. Also, continuously, the load was increased by 5% every 24 hours, the total mileage until the tire was broken was measured, and the result when the adhesive composition of Comparative Example 1 was used was set to 100 and indicated as an index. Is shown in Table 1 below, and was taken as tire durability.

[0063]

[Table 1]

As is evident from the results in Table 1, Examples 1 and 2 according to the present invention were compared with Comparative Examples 1 and 2, which were out of the scope of the present invention, in terms of initial adhesive strength, heat-resistant adhesive strength, and tire. (High speed) It turned out that it was excellent in durability.

[0065]

The present invention (claims 1 to 7, 10 and 11)
According to the method, when the phenol / aldehyde condensate (A) which is hardly water-soluble is converted into a sulfomethylated product or a sulfimethylated product, the phenol / aldehyde condensate can be dissolved in water at pH 4.5 to pH 10, and thus an alkali addition for dissolving the phenol / aldehyde condensate is performed. In order to reduce the amount of phenols and aldehyde condensates,
Since it can be as low as 5.0 to 8.0, cross-linking and curing of the adhesive layer during the vulcanization step and adhesion deterioration during continuous use at high temperatures are reduced, and the adhesive strength, particularly the heat-resistant adhesive strength, is reduced. An excellent adhesive composition and a method for producing the same are provided. Further, according to the invention of claim 8, since the rubber reinforcing organic fiber is subjected to an adhesive treatment with an adhesive composition having excellent adhesive strength, especially heat resistant adhesive strength, the rubber reinforcing organic fiber excellent in durability is obtained. Is provided. Further, according to the invention of claim 9, a cord comprising a rubber reinforcing organic fiber which has been subjected to an adhesive treatment with an adhesive composition having excellent adhesive strength, especially heat resistant adhesive strength, is used as a reinforcing material for a pneumatic tire. Therefore, a pneumatic tire having excellent durability is provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4J002 AC01X AC02X AC08X AC09X AC10X AC11X BB18X BG04X CC063 CC07W DE056 FD206 GJ01 GN01 HA07 4J040 CA011 CA012 CA031 CA032 CA081 CA082 CA141 CA142 DA141 DA142 DF041 HA02 EB04 EB041 LA08 MA01 MA05 MA10 MA12 MB02 NA16 QA01

Claims (11)

[Claims] 1. A phenolic condensate (A) comprising a sulfomethylated product or a sulfimethylated product of a condensate of a phenol having a methylol group and an aldehyde or an aldehyde donor, a rubber latex (B) and a resorcinol.
Containing the formaldehyde condensate (C), wherein the ratio of the component A / (component B + component C) is 5/100 to
An adhesive composition characterized by being in the range of 85/100, and wherein the ratio of the component C / B is in the range of 5/100 to 30/100 in terms of solids weight ratio. 2. The phenol-based condensate (A) has a pH for dissolving 100 g in dry weight of 400 g of water.
The adhesive composition according to claim 1, wherein the composition is soluble in water within a pH range of 4.5 to 8.0. 3. The adhesive composition according to claim 1, wherein the pH is adjusted with sodium hydroxide. 4. The adhesive composition according to claim 1, wherein the pH is in the range of 5.0 to 8.0. 5. The adhesive composition according to claim 1, wherein the resorcinol-formaldehyde condensate (C) is obtained by performing a condensation reaction while mixing rubber latex. 6. The adhesive composition according to claim 1, wherein the phenolic condensate (A) is obtained by performing a condensation reaction under the mixing of the rubber latex. 7. The phenol for obtaining the phenol condensate (A) is at least one selected from phenol, alkylphenol, m-methoxyphenol, halophenol, aminophenol, nitrophenol, resorcin, and alkylresorcin. Claim 1
7. The adhesive composition according to any one of items 6 to 6. 8. An organic fiber for reinforcing rubber, which has been subjected to an adhesive treatment with the adhesive composition according to claim 1. Description: 9. A pneumatic tire using the cord made of the rubber reinforcing organic fiber according to claim 8 as a reinforcing material for a pneumatic tire. 10. The method for producing an adhesive composition according to claim 1, wherein the phenolic condensate (A) is obtained by a condensation reaction or a cocondensation reaction between a phenol and an aldehyde. A method for producing an adhesive composition, comprising adding and reacting a sulfomethylating agent and / or a sulfimethylating agent before, during, or after the reaction. 11. The method for producing an adhesive composition according to claim 10, wherein the resorcinol-formaldehyde condensate (C) is obtained by performing a condensation reaction while mixing rubber latex.