JP7590225B2 - Adhesive composition, organic fiber cord-rubber composite and tire - Google Patents

Description

The present invention relates to an adhesive composition for organic fiber cords that does not contain resorcin, which reduces the environmental impact and has good adhesion, a method for producing the adhesive composition for organic fiber cords, and organic fiber cords, rubber reinforcing members (organic fiber cord-rubber composites), and tires that use the adhesive composition.

In rubber products such as tires, belts, air springs, and rubber hoses, organic fibers such as polyester fibers are used as reinforcing materials to supplement the strength of the products in the form of filaments, cords, cables, woven cords, canvas, etc.

When the organic fiber is used as the reinforcing material in the form of an organic fiber cord, the organic fiber cord is first treated with an adhesive composition for organic fiber cords. The organic fiber cord treated with the adhesive composition for organic fiber cords is then adhered to a coating rubber composition to form an organic fiber cord-rubber composite. The organic fiber cord-rubber composite thus obtained is used as a reinforcing member for rubber articles such as tires.

Conventionally, RFL (resorcinol, formalin, latex) organic fiber cord adhesives containing resorcinol, formalin, and rubber latex have been used as the adhesive composition for organic fiber cords in order to ensure adhesive strength through heat curing (see Patent Documents 1 to 3).

In order to further improve the adhesive strength, it is also known to use a resorcinol-formaldehyde resin obtained by precondensing resorcinol and formalin (see Patent Documents 4 and 5), or to pretreat organic fiber cords made of polyester fibers or the like with an epoxy resin.

Although resorcinol is an important raw material for forming the cross-linked structure in the resin necessary for adhesive strength, in recent years there has been a demand to reduce its usage from an environmental perspective.

In this context, adhesive compositions for organic fiber cords that do not contain resorcin and are more favorable for the environment and working environment, methods for producing said adhesive compositions, and organic fiber cords, organic fiber cord-rubber composites, and tires that use them have been proposed (Patent Documents 6 and 7). However, these have not been put to practical use due to the slow curing of the adhesive, which results in a large amount of the adhesive adhering to the adhesive drying and curing equipment, resulting in low productivity. Furthermore, there is also the problem that the adhesive itself has a weak adhesive strength.

JP 58-2370 A JP 60-92371 A Japanese Patent Publication No. 60-96674 Japanese Patent Publication No. 63-249784 Patent Publication No. 63-61433 JP 2010-255153 A Patent No. 5990825

The present invention was made in consideration of such circumstances, and aims to provide an adhesive composition for organic fiber cords that does not contain resorcin, which has a low environmental impact and good adhesion, a method for producing the adhesive composition for organic fiber cords, and organic fiber cords, rubber reinforcing members (organic fiber cord-rubber composites), and tires that use the adhesive composition.

In order to solve the above problems, the present inventors conducted various studies on the composition of the adhesive for organic fiber cords. As a result, they discovered that an adhesive composition for organic fiber cords, which is characterized by containing (1) a naphthalene compound having a hydrophilic functional group, and (2) an aldehyde compound, is an adhesive composition for organic fiber cords that has a low environmental impact and good adhesion because it does not contain resorcin, and thus has completed the present invention.

That is, the adhesive composition for organic fiber cords of the present invention comprises:
[Item 1]
The following compound:
(1) a naphthalene compound having a hydrophilic functional group, and (2) an aldehyde compound,
An adhesive composition for organic fiber cords, comprising:
It is.
Such an adhesive composition for organic fiber cords does not contain resorcin and therefore has a low environmental impact and good adhesive properties.

The adhesive composition for organic fiber cords of the present invention further comprises:
[Item 2]
Features:
(A) comprising a first bath processing solution and a second bath processing solution;
(B) the first bath treatment liquid is a composition containing (3) an epoxy compound, and (C) the second bath treatment liquid is a composition containing (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound.
Item 2. The adhesive composition for organic fiber cords according to item 1,
It is preferable that:
Such an adhesive composition for organic fiber cords is an adhesive composition for organic fiber cords having better adhesive properties.

Furthermore, the adhesive composition for organic fiber cords of the present invention has
[Item 3]
Item 1, further comprising (4) a latex;
It is preferable that:
Such an adhesive composition for organic fiber cords provides good bonding by co-vulcanization between the adhesive layer of the adhesive composition for organic fiber cords and the coating rubber composition. In addition, (4) the latex exhibits the advantage of being relatively soft and flexible, and allows the adhesive layer to accompany deformation of the organic fiber cord without splitting.

Furthermore, the adhesive composition for organic fiber cords of the present invention comprises:
[Item 4]
Item 3. The adhesive composition for organic fiber cords according to Item 2, wherein the second bath treatment liquid further contains (4) a latex.
It is preferable that:
Such an adhesive composition for organic fiber cords provides better bonding by co-vulcanization between the adhesive layer of the adhesive composition for organic fiber cords and the coating rubber composition. In addition, (4) the latex exhibits the advantage of being relatively soft and flexible, and allows the adhesive layer to accompany deformation of the organic fiber cord without splitting.

In addition, the adhesive composition for organic fiber cords of the present invention has
[Item 5]
5. The adhesive composition for organic fiber cords according to any one of items 1 to 4, wherein the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having a hydroxyl group;
It is preferable that:
Such an adhesive composition for organic fiber cords has superior adhesive properties.

In addition, the adhesive composition for organic fiber cords of the present invention comprises:
[Item 6]
5. The adhesive composition for organic fiber cords according to any one of items 1 to 4, wherein the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having two or more hydroxyl groups.
It is preferable that:
Such an adhesive composition for organic fiber cords has superior adhesive properties.

In addition, the adhesive composition for organic fiber cords of the present invention further comprises:
[Item 7]
5. The adhesive composition for organic fiber cords according to any one of Items 1 to 4, wherein the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having hydroxyl groups at the 1-position and the 4-position (para-position) of the naphthalene skeleton.
It is preferable that:
Such an adhesive composition for organic fiber cords has superior adhesive properties.

In addition, the adhesive composition for organic fiber cords of the present invention further comprises:
[Item 8]
The adhesive composition for organic fiber cords according to any one of items 1 to 7, further comprising (5) an isocyanate compound;
It is preferable that:
Such an adhesive composition for organic fiber cords has superior adhesive properties.

The adhesive composition for organic fiber cords of the present invention further comprises:
[Item 9]
The adhesive composition for organic fiber cords according to any one of Items 3 to 8, wherein the latex (4) contains at least one selected from the group consisting of natural rubber (NR), polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), halogenated butyl rubber, acrylonitrile-butadiene rubber (NBR), and vinylpyridine-styrene-butadiene copolymer rubber (Vp);
It is preferable that:
Such an adhesive composition for organic fiber cords provides better bonding by co-vulcanization between the adhesive layer of the adhesive composition for organic fiber cords and the coating rubber composition. The latex also exhibits the advantage of being softer and more flexible, allowing the adhesive layer to accompany deformation of the organic fiber cord without splitting.

The method for producing the adhesive composition for organic fiber cords of the present invention includes the steps of:
[Item 10]
The following steps:
(a) (1) a step of dissolving a naphthalene compound having a hydrophilic functional group in a basic solution to obtain a solution a; and (b) a step of dissolving an aldehyde compound in the solution a and aging the solution to obtain a solution b.
A method for producing the adhesive composition for organic fiber cords according to any one of items 1 to 9, comprising:
It is.
The method for producing an adhesive composition for organic fiber cords can stably and efficiently produce the adhesive composition for organic fiber cords according to the present invention by increasing the solubility of (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound.

The organic fiber cord of the present invention is
[Item 11]
An organic fiber cord treated with the adhesive composition for organic fiber cords according to any one of items 1 to 9.
It is.
Such an organic fiber cord is produced using materials and methods that impose little burden on the environment, and is coated with the adhesive composition for organic fiber cords according to any one of items 1 to 9, so that the organic fiber cord has good adhesion to a coating rubber composition.

The organic fiber cord-rubber composite of the present invention is
[Item 12]
Item 12. An organic fiber cord-rubber composite using the organic fiber cord according to item 11.
It is.
Such an organic fiber cord-rubber composite is produced using materials and methods that impart low environmental impact, and is excellent in imparting performance such as strength and durability as a reinforcing member for rubber articles such as tires.

The tire of the present invention is
[Item 13]
Item 13. A tire using the organic fiber cord-rubber composite according to item 12.
It is.
Such a tire is manufactured using materials and methods that impose a low environmental load, and is excellent in performance such as strength and durability as a tire.

The present invention provides an adhesive composition for organic fiber cords that does not contain resorcin, which has a low environmental impact and good adhesion, a method for producing the adhesive composition for organic fiber cords, and organic fiber cords, rubber reinforcing members (organic fiber cord-rubber composites), and tires that use the adhesive composition.

FIG. 1 is a schematic cross-sectional view of an example of an organic fiber cord (adhesive-coated fiber) treated with the adhesive composition for organic fiber cords of the present invention when the adhesive composition for organic fiber cords of the present invention is used in a one-bath treatment system. FIG. 1 is a schematic cross-sectional view of an example of an organic fiber cord (adhesive-coated fiber) treated with the adhesive composition for organic fiber cords of the present invention when the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system.

The following is a detailed description of an embodiment of the present invention. The description is intended to be an example of the present invention and does not limit the present invention in any way.

<% by mass>
In this specification, unless otherwise specified, the mass % representing the content of a component in the adhesive composition for organic fiber cords, the first bath treatment liquid, or the second bath treatment liquid represents the mass % as a ratio of the solid content contained in a dried product of the adhesive composition for organic fiber cords, in a dried product of the first bath treatment liquid, or in a dried product of the second bath treatment liquid, respectively.

<Organic fiber cord>
The organic fiber cord according to the adhesive composition for organic fiber cords of the present invention may be used to supplement the strength of rubber articles such as tires. When using the organic fiber cord as a reinforcing material for rubber articles such as tires, first, organic fibers are twisted to form an organic fiber cord. Next, the organic fiber cord is treated with the adhesive composition for organic fiber cords. Furthermore, the organic fiber cord treated with the adhesive composition for organic fiber cords is adhered to a coating rubber composition to form an organic fiber cord-rubber composite. The organic fiber cord-rubber composite thus obtained is used as a reinforcing member for rubber articles such as tires.

Examples of the material for the organic fiber cord include organic fibers such as polyethylene terephthalate (PET) fibers, polyethylene naphthalate fibers, polyamide fibers such as nylon, polyketone fibers, aromatic polyamide fibers, polyparaphenylene benzobisoxazole fibers, rayon fibers, lyocell fibers, etc. The organic fiber cord may be used in the form of a single fiber filament, or in the form of an assembly of a plurality of single fiber filaments.
The fibers constituting the organic fiber cord are intended to be used as cord reinforcing materials for rubber articles such as tires, belts, air springs, and rubber hoses, and therefore the average diameter of the monofilament is preferably 2 μm or more, and more preferably in the range of 15 μm or more and 50 μm or less.

When the organic fiber cord is intended to be used as a tire cord, for example, the organic fiber cord can be used as a single fiber filament, or can be used in the form of an assembly made by twisting together multiple single fiber filaments of organic fibers.

<Adhesive composition for organic fiber cords>
The adhesive composition for organic fiber cords of the present invention comprises the following compound:
(1) a naphthalene compound having a hydrophilic functional group, and (2) an aldehyde compound,
The present invention is characterized by comprising:

を有する化合物のことを言う。前記ナフタレン化合物は、上記ナフタレン骨格の1位から8位の何れかの位置で、水素以外の置換基を有することがある。前記（１）親水性官能基を有するナフタレン化合物は、上記ナフタレン骨格の1位から8位の何れかの位置で、少なくとも1つの親水性官能基の置換基を有する。 <<(1) Naphthalene Compound Having Hydrophilic Functional Group>>
The naphthalene compound having a hydrophilic functional group in the adhesive composition for organic fiber cords of the present invention is a naphthalene compound having a naphthalene skeleton represented by the following structural formula (I):

The naphthalene compound may have a substituent other than hydrogen at any one of the 1st to 8th positions of the naphthalene skeleton. The (1) naphthalene compound having a hydrophilic functional group has at least one hydrophilic functional group substituent at any one of the 1st to 8th positions of the naphthalene skeleton.

The hydrophilic functional group of the naphthalene compound having a hydrophilic functional group (1) in the adhesive composition for organic fiber cords of the present invention means a functional group that exhibits affinity for water by forming a hydrogen bond with a water molecule (H ₂ O). Examples of the hydrophilic functional group include, but are not limited to, a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfo group (-SO ₃ H), an amino group (-NH ₂ ), etc.

The (1) naphthalene compound having a hydrophilic functional group in the adhesive composition for organic fiber cords of the present invention is preferably a naphthalene compound having a hydroxyl group.
This is because, if the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having a hydroxyl group, the solubility in water/basic solvent is increased, and the ability to prepare a resin is improved.

Moreover, the (1) naphthalene compound having a hydrophilic functional group in the adhesive composition for organic fiber cords of the present invention is preferably a naphthalene compound having two or more hydroxyl groups.
This is because, if the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having two or more hydroxyl groups, the solubility in water/basic solvent is increased, and the ability to prepare a resin is improved.

The (1) naphthalene compound having a hydrophilic functional group in the adhesive composition for organic fiber cords of the present invention is preferably a naphthalene compound having hydroxyl groups at the 1-position and 4-position (para-position) of the naphthalene skeleton.
This is because, if the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having hydroxyl groups at the 1-position and 4-position (para-position) of the naphthalene skeleton, the solubility in water/basic solvent is increased, and the ability to prepare a resin is further improved.

1,7-ジヒドロキシナフタレン

2,7-ジヒドロキシナフタレン

1,4-ジヒドロキシナフタレン-2-スルホン酸アンモニウム

（上記構造式（II）中、Yは下記構造式（III）：

（上記構造式（III）中、R²、R³、R⁴は水素原子である。）、
が含まれる。
これらは、一種を単独で用いても良いし、二種以上を組み合わせて用いても良い。 Examples of the (1) naphthalene compound having a hydrophilic functional group in the adhesive composition for organic fiber cords of the present invention include, but are not limited to,
6-Hydroxy-1-naphthoic acid

1,7-Dihydroxynaphthalene

2,7-Dihydroxynaphthalene

1,4-Dihydroxynaphthalene-2-sulfonic acid ammonium salt

(In the above structural formula (II), Y is represented by the following structural formula (III):

(In the above structural formula (III), R ² , R ³ , and R ⁴ are hydrogen atoms.)
Includes:
These may be used alone or in combination of two or more.

The (1) naphthalene compound having a hydrophilic functional group in the adhesive composition for organic fiber cords of the present invention is preferably 1,4-dihydroxynaphthalene-2-ammonium sulfonate.
The 1,4-dihydroxynaphthalene-2-ammonium sulfonate has particularly excellent solubility in water/basic solvents, and (1) an adhesive composition for organic fiber cords containing 1,4-dihydroxynaphthalene-2-ammonium sulfonate as a naphthalene compound having a hydrophilic functional group has higher adhesive ability.

In addition, 1,4-dihydroxynaphthalene-2-ammonium sulfonate can be synthesized, for example, by a method of performing an addition reaction by mixing with an aqueous solution of hydrogen sulfite, and it is also possible to use a commercially available product such as "Kinopower" manufactured by Kawasaki Kasei Chemical Industries, Ltd.

The content of (1) the naphthalene compound having a hydrophilic functional group in the adhesive composition for organic fiber cords of the present invention is not particularly limited, but in order to ensure better adhesion, the solid content in the dried product of the adhesive composition for organic fiber cords is preferably 3.0% by mass or more, and more preferably 3.5% by mass or more.

The content of (1) the naphthalene compound having a hydrophilic functional group in the adhesive composition for organic fiber cords of the present invention is not particularly limited, but in order to ensure that the naphthalene compound having a hydrophilic functional group (1) is dissolved and to obtain better workability, the content is preferably 13% by mass or less, and more preferably 11% by mass or less, as a ratio of the solid content contained in the dried product of the adhesive composition for organic fiber cords.

When a naphthalene compound having a hydrophilic functional group further carries at least one aldehyde functional group in one molecule, the compound is not considered to be (1) a naphthalene compound having a hydrophilic functional group, but is considered to be included in (2) an aldehyde compound.

<<(2) Aldehyde Compounds>>
The (2) aldehyde compound in the adhesive composition for organic fiber cords of the present invention refers to a compound having at least one aldehyde functional group in one molecule.

The (2) aldehyde compound in the adhesive composition for organic fiber cords of the present invention is not particularly limited, but examples thereof include monoaldehydes such as formaldehyde, acetaldehyde, butylaldehyde, acrolein, propionaldehyde, chloral, butylaldehyde, caproaldehyde, and allylaldehyde, aliphatic dialdehyde compounds such as glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, and adipaldehyde, aldehyde compounds having an aromatic ring such as diformylfuran, terephthalaldehyde, naphthalenedialdehyde, and 2-hydroxy-1-naphthaldehyde, and dialdehyde starch. These aldehyde compounds may be used alone or in combination.

The (2) aldehyde compound in the adhesive composition for organic fiber cords of the present invention is preferably formaldehyde or an aldehyde compound having an aromatic ring.
(2) An adhesive composition for organic fiber cords that contains formaldehyde or an aldehyde compound having an aromatic ring as the aldehyde compound can form a relatively inexpensive resin that has excellent mechanical strength, electrical insulation properties, acid resistance, water resistance, heat resistance, etc.

Here, the aldehyde compound having an aromatic ring is an aromatic aldehyde that contains at least one aromatic ring and carries at least one aldehyde functional group in one molecule.
If an aldehyde having an aromatic ring is used as the aldehyde compound (2) instead of formaldehyde, the adhesive composition for organic fiber cords of the present invention imposes less of a burden on the environment.

The aldehyde compound having an aromatic ring is preferably an aromatic polyaldehyde compound carrying two or more aldehyde functional groups in one molecule. Since the aromatic polyaldehyde compound has two or more aldehyde groups in one molecule, it effectively functions as a crosslinking agent by the aldehyde group. In addition, the aromatic ring is preferably an aromatic ring that directly carries an aldehyde functional group, and the aldehyde functional group may be present at the ortho, meta, or para position on the aromatic ring.

Preferably, the aromatic ring of the aldehyde compound having an aromatic ring is a benzene ring, a furan ring, or a naphthalene ring. More preferably, the polyaldehyde is selected from the group consisting of 1,2-benzenedicarbaldehyde, 1,3-benzenedicarbaldehyde, 1,4-benzenedicarbaldehyde, 2-hydroxybenzene-1,3,5-tricarbaldehyde, diformylfuran, naphthaldehyde, and mixtures of these compounds.

Even more preferably, the aldehyde compound having an aromatic ring is 1,4-benzenedicarbaldehyde (also called terephthalaldehyde) having the following structural formula:

（上記構造式（IV）中、X は O である；R は、-H、-CHO、又はメチロールを示す。）

更により具体的には、上記のフラン環を有するアルデヒド化合物として、例えば、以下の化合物が挙げられる。

Examples of aldehyde compounds having a furan ring include compounds having the following structural formula (IV) (diformylfuran, 5-(hydroxymethyl)furfural, etc.).

(In the above structural formula (IV), X is O; R is -H, -CHO, or methylol.)

More specifically, examples of the aldehyde compound having a furan ring include the following compounds.

These aldehyde compounds having aromatic rings have a smaller environmental impact than formaldehyde and can be used as materials for adhesive compositions for organic fiber cords that have good adhesive properties at a reasonable cost compared to other aldehyde compounds.

The content of the (2) aldehyde compound in the adhesive composition for organic fiber cords of the present invention is not particularly limited, but in order to ensure better adhesion, the content is preferably 1.0% by mass or more, and more preferably 2.5% by mass or more, as a ratio of the solid content in the dried product of the adhesive composition for organic fiber cords.

The content of the (2) aldehyde compound in the adhesive composition for organic fiber cords of the present invention is not particularly limited, but in order to ensure that the (2) aldehyde compound dissolves and to obtain better workability, the content is preferably 10% by mass or less, and more preferably 9.0% by mass or less, as a ratio of the solid content contained in the dried product of the adhesive composition for organic fiber cords.

In the adhesive composition for organic fiber cords of the present invention, the mass ratio of (1) the naphthalene compound having a hydrophilic functional group to (2) the aldehyde compound in the adhesive composition for organic fiber cords (the ratio of the solids contained in the dry matter of the adhesive composition for organic fiber cords) is preferably 0.1 or more and 4.0 or less, and more preferably 0.25 or more and 3.0 or less.
A condensation reaction occurs between (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound, and at a mass ratio within the above range, the resulting resin has more suitable water solubility and adhesiveness.

<<Other chemicals that may be used>>
Other chemicals that may be blended into the adhesive composition for organic fiber cords of the present invention are not particularly limited, and may further include (3) an epoxy compound, (4) a latex, (5) an isocyanate compound, 2,5-di(hydroxymethyl)furan, and/or polyphenols.
When the adhesive composition for organic fiber cords of the present invention contains polyphenols, the total content of the polyphenols and the aldehydes having an aromatic ring in the adhesive composition for organic fiber cords is preferably 5-65% by mass, and more preferably 5-40% by mass, because this ensures better adhesion without impairing workability, including solubility in solvents.
The (3) epoxy compound, (4) latex, and (5) isocyanate compound will be described later.

<First bath processing solution and second bath processing solution>
The adhesive composition for organic fiber cords of the present invention may be used in a one-bath treatment system using only one treatment solution containing (1) a naphthalene compound having a hydrophilic functional group, and (2) an aldehyde compound.
The adhesive composition for organic fiber cords of the present invention may also be used in a two-bath treatment system containing at least two treatment baths, a first bath treatment bath and a second bath treatment bath, by separately preparing a treatment bath containing other compounds.
The adhesive composition for organic fiber cords of the present invention is preferably a one-bath treatment system from the viewpoints of reducing processing costs and enabling use in smaller facilities.
On the other hand, from the viewpoint of further enhancing adhesiveness, the adhesive composition for organic fiber cords of the present invention is preferably a two-bath treatment system.

That is, from the viewpoint of further enhancing adhesiveness, the adhesive composition for organic fiber cords of the present invention has the following features:
Features:
(A) comprising a first bath processing solution and a second bath processing solution;
(B) the first bath treatment liquid is a composition containing (3) an epoxy compound, and (C) the second bath treatment liquid is a composition containing (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound.
An adhesive composition for organic fiber cords,
It is preferable that:

Here, the first bath treatment liquid refers to a treatment liquid used to form an adhesive layer on the outer surface in the outer diameter direction of the organic fiber cord in a process of treating the organic fiber cord with an adhesive composition for organic fiber cords, prior to treatment with the second bath treatment liquid described below.

The second bath treatment liquid, on the other hand, refers to a treatment liquid used in a process of treating an organic fiber cord with an adhesive composition for organic fiber cords, after treatment with the first bath treatment liquid, to form another adhesive layer on the outer surface in the outer diameter direction of the organic fiber cord on which an adhesive layer has been formed by the first bath treatment liquid.

In the process of treating an organic fiber cord with an adhesive composition for organic fiber cords, any treatment may be optionally performed on the organic fiber cord at any time before the organic fiber cord is treated with the first bath treatment liquid, after the organic fiber cord is treated with the first bath treatment liquid and before the organic fiber cord is treated with the second bath treatment liquid, and/or after the organic fiber cord is treated with the second bath treatment liquid.

When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, the preferred content of (1) naphthalene compounds having hydrophilic functional groups, the preferred content of (2) aldehyde compounds, and the preferred mass ratio of (1) naphthalene compounds having hydrophilic functional groups to (2) aldehyde compounds (ratio of solids contained in the dried product of the second bath treatment solution) in the second bath treatment solution of the adhesive composition for organic fiber cords are the same as the preferred content of (1) naphthalene compounds having hydrophilic functional groups, the preferred content of (2) aldehyde compounds, and the preferred mass ratio of (1) naphthalene compounds having hydrophilic functional groups to (2) aldehyde compounds (ratio of solids contained in the dried product of the adhesive composition for organic fiber cords) in the adhesive composition for organic fiber cords of the present invention described above.

<<(3) Epoxy compound>>
When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, the first bath treatment liquid of the adhesive composition for organic fiber cords is preferably a composition containing an epoxy compound (3).

The epoxy compound (3) is a compound having at least one epoxy group in one molecule. The epoxy compound (3) acts as a crosslinking agent for the adhesive composition and has excellent adhesion, heat resistance, durability, strength, flexibility, electrical insulation, etc.

The epoxy compound (3) is not particularly limited, but is preferably a compound having two or more epoxy groups in one molecule, and more preferably a compound having four or more epoxy groups in one molecule. When the epoxy compound has two or more epoxy groups in one molecule, the compound effectively functions as a crosslinking agent due to the epoxy groups, and when the epoxy compound has four or more epoxy groups, crosslinking occurs more densely and greater flexibility is imparted.
The epoxy compound (3) is not particularly limited, but preferably has 10 or less epoxy groups in one molecule, because the crosslinking density is not excessive and toughness is also provided.

The epoxy compound (3) is not particularly limited, but specific examples thereof include reaction products of epichlorohydrin with polyhydric alcohols such as diethylene glycol diglycidyl ether, polyethylene diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythrityl polyglycidyl ether, diglycerol polyglycidyl ether, and sorbitol polyglycidyl ether.
These may be used alone or in combination of two or more.
When these compounds are used as the epoxy compound (3), the adhesive composition for organic fiber cords can have better adhesive properties.

When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, the content of the (3) epoxy compound in the first bath treatment liquid of the adhesive composition for organic fiber cords is not particularly limited, but is preferably in the range of more than 5 mass % and not more than 95 mass %, more preferably in the range of 15 mass % or more and 85 mass % or less, and even more preferably in the range of 15 mass % or more and 50 mass % or less, as a ratio of the solid content contained in the dried matter of the first bath treatment liquid.
If the content is more than 5% by mass, more crosslinking by the epoxy resin is formed in the adhesive layer of the adhesive composition for organic fiber cords, and the cohesive fracture resistance and adhesive strength at high temperatures are improved and more flexibility is imparted, whereas if the content is 95% by mass or less, the resin crosslinking formed in the adhesive layer is sufficient and the adhesive layer also has more toughness.

<(4) Latex>
The adhesive composition for organic fiber cords of the present invention preferably further contains (4) a latex.
When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, the second bath treatment liquid of the adhesive composition for organic fiber cords preferably further contains (4) latex.

The adhesive composition for organic fiber cords of the present invention, or the second bath treatment liquid of the adhesive composition for organic fiber cords, further contains (4) latex, which may provide good bonding by co-vulcanization between the adhesive layer of the adhesive composition for organic fiber cords and the coating rubber composition. In addition, latex has the advantage of being relatively soft and flexible, and allows the organic fiber cord to be deformed without the adhesive layer splitting.

The latex (4) is not particularly limited, and in addition to natural rubber (NR), synthetic rubbers such as polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), halogenated butyl rubber, acrylonitrile-butadiene rubber (NBR), and vinylpyridine-styrene-butadiene copolymer rubber (Vp) can be used. These rubber components may be used alone or in combination of two or more.

The content of (4) the latex in the adhesive composition for organic fiber cords of the present invention is not particularly limited, but from the viewpoint of ensuring better adhesion, the content is preferably 30 mass % or more, and more preferably 50 mass % or more, as a ratio of the solid content contained in the dry product of the adhesive composition for organic fiber cords.
The content of (4) latex in the adhesive composition for organic fiber cords of the present invention is not particularly limited, but in order to ensure that the amounts of resin components and the like contained as components other than the (4) latex in the adhesive composition for organic fiber cords are at least a certain amount relative to one another and thereby to ensure sufficient cohesive fracture resistance of the adhesive layer, the content is preferably 90 mass % or less, and more preferably 85 mass % or less.

<(5) Isocyanate Compound>
The adhesive composition for organic fiber cords of the present invention preferably further contains (5) an isocyanate compound.

This is because the (5) isocyanate compound has the effect of promoting adhesion of the adhesive composition for organic fiber cords of the present invention to a resin material (for example, an organic fiber material) that is an adherend.
In addition, the (5) isocyanate compound can greatly enhance the adhesive properties of the adhesive composition for organic fiber cords of the present invention through a synergistic effect with the (1) naphthalene compound having a hydrophilic functional group, including the formation of a crosslinked structure, and the (2) aldehyde compound.

The (5) isocyanate compound is a compound having at least one isocyanate group in one molecule as a polar functional group. In this specification, the term "isocyanate group" refers to a blocked isocyanate group or an isocyanate group, and includes, in addition to an isocyanate group, a blocked isocyanate group formed by reacting with a blocking agent for an isocyanate group, an isocyanate group that has not reacted with a blocking agent for an isocyanate group, or an isocyanate group formed by dissociation of the blocking agent of a blocked isocyanate group.

The (5) isocyanate compound preferably contains an aromatic ring. This is because the (5) isocyanate compound containing an aromatic ring is more easily dispersed into the gaps between the polymer chains of the resin. Furthermore, the (5) isocyanate compound preferably contains a molecular structure in which aromatics are bonded by an alkylene chain, and more preferably contains a molecular structure in which aromatics are bonded by methylene. Examples of molecular structures in which aromatics are bonded by an alkylene chain include molecular structures found in diphenylmethane diisocyanate, polyphenylene polymethylene polyisocyanate, and condensates of phenols and formaldehyde. Furthermore, the (5) isocyanate compound is preferably polyphenylene polymethylene polyisocyanate having a number average molecular weight of 6,000 or less, and particularly preferably polyphenylene polymethylene polyisocyanate having a number average molecular weight of 4,000 or less.

Examples of the (5) isocyanate compound include a compound containing an aromatic polyisocyanate and a thermally dissociable blocking agent, a water-dispersible compound containing a component in which diphenylmethane diisocyanate or an aromatic polyisocyanate is blocked with a thermally dissociable blocking agent, and an aqueous urethane compound.
These may be used alone or in combination of two or more.

As a compound containing the aromatic polyisocyanate and a thermally dissociable blocking agent, a blocked isocyanate compound containing diphenylmethane diisocyanate and a known isocyanate blocking agent is preferably used. As a water-dispersible compound containing a component in which the diphenylmethane diisocyanate or aromatic polyisocyanate is blocked with a thermally dissociable blocking agent, a reaction product in which diphenylmethane diisocyanate or polyphenylene polymethylene polyisocyanate is blocked with a known blocking agent that blocks isocyanate groups is exemplified. Specifically, commercially available blocked polyisocyanate compounds such as Elastron BN69 and Elastron BN77 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and Meikanate TP-10 (manufactured by Meisei Chemical Industry Co., Ltd.) can be used.

The aqueous urethane compound is obtained by reacting an organic polyisocyanate compound (α) containing a molecular structure in which aromatics are bonded by alkylene chains, preferably a molecular structure in which aromatics are bonded by methylene, a compound (β) having a plurality of active hydrogen groups, and a thermally dissociable blocking agent (γ) for isocyanate groups. In addition, the aqueous urethane compound has a flexible molecular structure, and therefore not only acts as an adhesion improver, but also acts as a flexible crosslinking agent to suppress the fluidization of the adhesive at high temperatures.
In addition, "aqueous" refers to being water-soluble or water-dispersible, and "water-soluble" does not necessarily mean completely water-soluble, but rather means being partially water-soluble or not undergoing phase separation in an aqueous solution of the adhesive composition of the present invention.

（上記構造式（V）中、Aは芳香族類がアルキレン鎖で結合された分子構造を含有する有機ポリイソシアネート化合物（α）の活性水素基が脱離した残基を示し、Yはイソシアネート基に対する熱解離性ブロック化剤（γ）の活性水素基が脱離した残基を示し、Zは化合物（δ）の活性水素基が脱離した残基を示し、Ｘは複数の活性水素基を有する化合物（β）の活性水素基が脱離した残基であり、nは2以上4以下の整数であり、p+mは2以上4以下の整数（m≧0.25）である。）
で表される水性ウレタン化合物が好ましい。 Here, the aqueous urethane compound may be, for example, a compound represented by the following structural formula (V):

(In the above structural formula (V), A represents a residue resulting from the removal of an active hydrogen group from an organic polyisocyanate compound (α) containing a molecular structure in which aromatics are bonded by an alkylene chain, Y represents a residue resulting from the removal of an active hydrogen group from a thermally dissociable blocking agent (γ) for an isocyanate group, Z represents a residue resulting from the removal of an active hydrogen group from a compound (δ), X represents a residue resulting from the removal of an active hydrogen group from a compound (β) having a plurality of active hydrogen groups, n is an integer of 2 or more and 4 or less, and p+m is an integer of 2 or more and 4 or less (m≧0.25).)
Preferred is an aqueous urethane compound represented by the following formula:

Examples of the organic polyisocyanate compound (α) having a molecular structure in which aromatics are bonded by alkylene chains include methylene diphenyl polyisocyanate and polyphenylene polymethylene polyisocyanate.
The compound (β) having a plurality of active hydrogen groups is preferably a compound having 2 to 4 active hydrogen groups and an average molecular weight of 5,000 or less. Examples of such compound (β) include (i) polyhydric alcohols having 2 to 4 hydroxyl groups, (ii) polyamines having 2 to 4 primary and/or secondary amino groups, (iii) amino alcohols having 2 to 4 primary and/or secondary amino groups and hydroxyl groups, (iv) polyester polyols having 2 to 4 hydroxyl groups, (v) polybutadiene polyols having 2 to 4 hydroxyl groups and copolymers thereof with other vinyl monomers, (vi) 2-hydroxybutadiene polyols having 2 to 4 hydroxyl groups and copolymers thereof with other vinyl monomers, (vii) 2-hydroxybutadiene polyols having 2 to 4 hydroxyl groups and copolymers thereof with other vinyl monomers, (viii) 2-hydroxybutadiene polyols having 2 to 4 hydroxyl groups and copolymers thereof with other vinyl monomers, (viiii ... (vii) polychloroprene polyols having from 2 to 4 hydroxyl groups and copolymers thereof with other vinyl monomers, and (vii) polyether polyols having from 2 to 4 hydroxyl groups, such as C2-C4 alkylene oxide polyadducts of polyhydric amines, polyhydric phenols, and amino alcohols, C2-C4 alkylene oxide polyadducts of C3 or higher polyhydric alcohols, C2-C4 alkylene oxide copolymers, and C3-C4 alkylene oxide polymers.
Furthermore, the thermally dissociable blocking agent (γ) for the isocyanate group is a compound capable of liberating an isocyanate group by heat treatment, and examples of such blocking agents include known isocyanate blocking agents.
Furthermore, the compound (δ) is a compound having at least one active hydrogen group and an anionic and/or nonionic hydrophilic group. Examples of the compound having at least one active hydrogen group and an anionic hydrophilic group include aminosulfonic acids such as taurine, N-methyltaurine, N-butyltaurine, sulfanilic acid, and aminocarboxylic acids such as glycine and alanine. On the other hand, examples of the compound having at least one active hydrogen group and a nonionic hydrophilic group include compounds having a hydrophilic polyether chain.

The content of the (5) isocyanate compound in the adhesive composition for organic fiber cords of the present invention is not particularly limited, but is preferably in the range of more than 5% by mass and not more than 95% by mass, more preferably in the range of 15% by mass or more and 85% by mass or less, and even more preferably in the range of 15% by mass or more and 70% by mass or less, as a ratio of the solid content contained in the dry matter of the adhesive composition for organic fiber cords. If it is contained in an amount of more than 5% by mass, the strength and chemical resistance of the adhesive layer by the adhesive composition for organic fiber cords are improved, and the adhesion and adhesion to the substrate are also improved. Also, if it is contained in an amount of 95% by mass or less, the cohesive fracture resistance of the adhesive layer at high temperatures can be sufficiently secured, and the adhesive strength at high temperatures is also sufficient.

When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, the (5) isocyanate compound can be contained in either the first bath treatment liquid or the second treatment liquid, or in both. Since the interaction between the (5) isocyanate compound and the organic fiber cord enhances adhesion, it is preferable to contain the (5) isocyanate compound in the first bath treatment liquid.

When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, and the first bath treatment liquid of the adhesive composition for organic fiber cords contains (5) an isocyanate compound, the content is not particularly limited, but is preferably in the range of more than 5% by mass and not more than 95% by mass, more preferably in the range of 15% by mass or more and 85% by mass or less, and even more preferably in the range of 15% by mass or more and 70% by mass or less, as a ratio of the solid content contained in the dried matter of the first bath treatment liquid. If it is contained in an amount of more than 5% by mass, the strength and chemical resistance of the adhesive layer by the adhesive composition for organic fiber cords are improved, and the adhesion and adhesion to the substrate are also improved. Also, if it is contained in an amount of 95% by mass or less, the cohesive fracture resistance of the adhesive layer at high temperatures can be sufficiently secured, and the adhesive strength at high temperatures is also sufficient.

When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, and the second bath treatment liquid of the adhesive composition for organic fiber cords contains (5) an isocyanate compound, the content is not particularly limited, but is preferably in the range of more than 5% by mass and not more than 95% by mass, more preferably in the range of 15% by mass or more and 85% by mass or less, and even more preferably in the range of 15% by mass or more and 70% by mass or less, as a ratio of the solid content contained in the dry matter of the second bath treatment liquid. If it is contained in an amount of more than 5% by mass, the strength and chemical resistance of the adhesive layer by the adhesive composition for organic fiber cords are improved, and the adhesion and adhesion to the substrate are also improved. Also, if it is contained in an amount of 95% by mass or less, the cohesive fracture resistance of the adhesive layer at high temperatures can be sufficiently secured, and the adhesive strength at high temperatures is also sufficient.

<Method of producing adhesive composition for organic fiber cord>
The method for producing the adhesive composition for organic fiber cords of the present invention is not particularly limited as long as it includes a step of dissolving (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound, and a step of aging the resin. Preferably,
A process for aging a naphthalene-aldehyde resin solution in which a naphthalene compound having a hydrophilic functional group and an aldehyde compound are dissolved in a solvent:
(a) (1) a step of dissolving a naphthalene compound having a hydrophilic functional group in a basic solution to obtain a solution a; and (b) a step of dissolving an aldehyde compound in the solution a and aging the solution to obtain a solution b.
The present invention is characterized by comprising:

Furthermore, when the adhesive composition for organic fiber cords of the present invention further contains (4) latex, the method for producing the adhesive composition for organic fiber cords of the present invention is not particularly limited as long as it includes a step of dissolving (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound and a step of resin aging, and further includes a step of mixing with latex and aging. Preferably,
A process of mixing and aging a naphthalene-aldehyde resin solution obtained by dissolving a naphthalene compound and an aldehyde compound having the following hydrophilic functional group in a solvent with a latex:
(a) (1) a step of dissolving a naphthalene compound having a hydrophilic functional group in a basic solution to obtain a solution a; and (b) a step of dissolving an aldehyde compound in the solution a and aging the solution to obtain a solution b.
(c) adding (4) latex to the solution b and mixing and maturing the solution b;
The present invention is characterized by comprising:

When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, the adhesive composition for organic fiber cords may contain (A) a first bath treatment liquid and a second bath treatment liquid. In this case, the method for producing the adhesive composition for organic fiber cords includes the following steps:
The following steps:
a step of preparing the second bath treatment liquid, the step including a step of aging a naphthalene-aldehyde resin solution in which the naphthalene compound having a hydrophilic functional group and an aldehyde compound are dissolved in a solvent, or a step of mixing and aging a naphthalene-aldehyde resin solution in which the naphthalene compound having a hydrophilic functional group and an aldehyde compound are dissolved in a solvent with a latex; and (d) a step of dissolving an epoxy compound in a solvent.
preparing the first bath treatment solution,
The present invention is characterized by comprising:

The method for producing such an adhesive composition for organic fiber cords can increase the solubility of (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound, and can uniformly disperse the adhesive composition for organic fiber cords of the present invention in a solvent, allowing stable and efficient production.

Conventionally, the components of the adhesive composition for organic fiber cords, (1) naphthalene compounds having hydrophilic functional groups and (2) aldehyde compounds, are difficult to dissolve in water, and simply blending them together results in dispersion in water, making them unusable as components of aqueous adhesive compositions. Therefore, in the manufacturing method for the adhesive composition for organic fiber cords of the present invention, (6) a basic solution is used as a solvent for dissolving (1) naphthalene compounds having hydrophilic functional groups and (2) aldehyde compounds. The basic solution (6) is not particularly limited, but is preferably one or more of basic solutions such as an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, and an aqueous ammonia solution.

In the method for producing the adhesive composition for organic fiber cords of the present invention, a preferred example of the dissolving method is as follows:
(a1) (1) Dissolving a naphthalene compound having a hydrophilic functional group in one or more selected basic solutions, and then diluting the solution with a required amount of water;
(b1) adding (2) an aldehyde compound little by little to a basic aqueous solution in which the naphthalene compound having a hydrophilic functional group is dissolved, and dissolving the (1) naphthalene compound having a hydrophilic functional group and the (2) aldehyde compound while causing a chemical reaction change;
Examples include:

As a result, according to the manufacturing method of the adhesive composition for organic fiber cords of the present invention, (1) the naphthalene compound having a hydrophilic functional group is sufficiently dissolved and becomes uniform in the liquid of the adhesive composition for organic fiber cords, and (2) the aldehyde compound is reliably dissolved. This makes it possible to improve the productivity of the adhesive composition for organic fiber cords of the present invention, which has excellent adhesive properties.

(6) The temperature of the basic solution is preferably 40°C or higher, and more preferably 60°C or higher, from the viewpoint of being able to more reliably dissolve (1) the naphthalene compound having a hydrophilic functional group and (2) the aldehyde compound and to increase productivity.

The pH of the (6) basic solution is preferably 9 or more and 13 or less, more preferably 10 or more and 12 or less, from the viewpoint of being able to more reliably dissolve (1) the naphthalene compound having a hydrophilic functional group and (2) the aldehyde compound and to increase productivity.

In the step (b) of dissolving the (2) aldehyde compound in the solution (a) and maturing the resin to obtain a solution (b), it is preferable to gradually add the (2) aldehyde compound in order to more reliably dissolve the (2) aldehyde compound while suppressing a decrease in productivity.

In the step (b) of dissolving (2) an aldehyde compound in the solution (a) and aging the resin to obtain solution (b), the resin aging is a treatment in which resin components such as (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound are placed at a predetermined temperature for a predetermined time. By carrying out resin aging, the adhesive properties of the adhesive composition for organic fiber cords can be improved. The resin aging can be carried out at any temperature for any time while stirring.

The temperature for the resin maturation (resin maturation temperature) is not particularly limited, but is preferably 20°C or higher, and more preferably 40°C or higher. If it is 20°C or higher, the adhesiveness of the adhesive composition for organic fiber cords is further increased. Furthermore, the resin maturation temperature is not particularly limited, but is preferably 80°C or lower, and more preferably 60°C or lower. If it is 60°C or lower, the increase in viscosity due to evaporation of the solution can be further suppressed.

The resin maturation time (resin maturation time) is not particularly limited, but is preferably 30 minutes or more, and more preferably 1 hour or more. If it is 1 hour or more, the adhesiveness of the adhesive composition for organic fiber cords will be further increased. Furthermore, the resin maturation time is not particularly limited, but is preferably 6 hours or less, and more preferably 4 hours or less. If it is 6 hours or less, it can be assumed that all solutes are dissolved and condensation has progressed.

In the step (c) of adding (4) latex to solution b and mixing and maturing, latex is added to solution b, which is a naphthalene-aldehyde resin solution prepared in advance, and then mixed and maturated (latex maturation).

The latex aging process is a process in which the liquid containing the latex (4) is left at a predetermined temperature for a predetermined time. By carrying out the latex aging process, the latex (4) can be more reliably solidified, and the adhesive composition for organic fiber cords can be made easier to handle and has improved adhesive properties. The latex aging process can be carried out at any temperature and for any time while stirring.

The temperature for maturing the latex (latex maturation temperature) is not particularly limited, but is preferably 20°C or higher and 40°C or lower, and more preferably about 25°C. This is because it is possible to suitably improve the properties of the latex.

The latex maturation time is not particularly limited, but is preferably from 15 minutes to one week, and more preferably from one hour to three days. This is because the properties of the latex can be suitably improved.

When the adhesive composition for organic fiber cords of the present invention further contains (5) an isocyanate compound, in the manufacturing method of the adhesive composition for organic fiber cords of the present invention, after adding latex to the naphthalene-aldehyde resin solution, the isocyanate compound may be added before or after maturing the latex.

The solvent used in the step (d) of dissolving the epoxy compound in a solvent is not particularly limited, and in addition to water, organic solvents such as various alcohols, toluene, xylene, n-hexane, cyclohexane, chloroform, and methyl ethyl ketone can be used.
These solvents may be used alone or in combination of two or more.
Such a solvent is preferably water, since this has a low environmental impact.

<Organic fiber cord treated with adhesive composition for organic fiber cord>
The organic fiber cord of the present invention is an organic fiber cord treated with the adhesive composition for organic fiber cords of the present invention.

Next, the organic fiber cord (adhesive-coated fiber) treated with the adhesive composition for organic fiber cords of the present invention will be described in detail with reference to the drawings.

Figure 1 is a schematic cross-sectional view of an example of an organic fiber cord (adhesive-coated fiber) 1 treated with the adhesive composition for organic fiber cords of the present invention when the adhesive composition for organic fiber cords is used in a one-bath treatment system. In the adhesive-coated fiber 1 shown in Figure 1, the surface of an organic fiber cord 2 is coated with an adhesive layer 3 of the adhesive composition for organic fiber cords of the present invention.

Figure 2 is a schematic cross-sectional view of an example of an organic fiber cord (adhesive-coated fiber) 10 treated with the adhesive composition for organic fiber cords of the present invention when the adhesive composition for organic fiber cords is used in a two-bath treatment system. In the adhesive-coated fiber 10 shown in Figure 2, the surface of an organic fiber cord 2 is coated with an adhesive layer 11 made of a first bath treatment liquid. The outer side in the outer diameter direction is further coated with an adhesive layer 12 made of a second bath treatment liquid.

In the case of an organic fiber cord (adhesive-coated fiber) treated with the adhesive composition for organic fiber cords of the present invention, the mass of the adhesive composition for organic fiber cords used is preferably 0.2% by mass or more and 6.0% by mass or less, expressed as the ratio of the solid content contained in each dry matter to the mass of the organic fiber cord to be adhered.

In the present invention, the method for covering the surface of an organic fiber cord with an adhesive layer of an adhesive composition for organic fiber cords is not particularly limited, but examples thereof include a method of immersing an organic fiber cord in an adhesive composition for organic fiber cords, a method of applying the adhesive composition for organic fiber cords to the surface of an organic fiber cord, and a method of spraying the adhesive composition for organic fiber cords onto an organic fiber cord.

When the adhesive composition for organic fiber cords of the present invention is used in a two-bath treatment system, the organic fiber cord is treated with a first bath treatment liquid and a second bath treatment liquid. In this case, the first bath treatment liquid is first coated on the outer diameter surface of the organic fiber cord using one of the coating methods described above. Then, the second bath treatment liquid is coated on the outer diameter surface of the organic fiber cord coated with an adhesive layer made of the first bath treatment liquid using one of the coating methods described above.

The method of coating the outer diameter surface of an organic fiber cord with an adhesive layer made from a first bath treatment liquid and the method of coating the outer diameter surface of an organic fiber cord coated with an adhesive layer made from the first bath treatment liquid with an adhesive layer made from a second bath treatment liquid may be the same or different.

When the adhesive composition for organic fiber cords used in the treatment of covering the surface of an organic fiber cord with an adhesive layer of the adhesive composition for organic fiber cords has a high viscosity, the adhesive composition for organic fiber cords may not be used as is, but may be used as an adhesive liquid obtained by diluting the adhesive composition for organic fiber cords with a solvent. The adhesive liquid includes a solution in which the components constituting the adhesive composition for organic fiber cords are completely or partially dissolved in a solvent, a dispersion in which the components constituting the adhesive composition for organic fiber cords are distributed in a solvent, etc.

The solvent for diluting the adhesive composition for organic fiber cords is not particularly limited, and in addition to water, various organic solvents such as alcohols, toluene, xylene, n-hexane, cyclohexane, chloroform, and methyl ethyl ketone can be used.
These solvents may be used alone or in combination of two or more.
Such a solvent is preferably water, since this has a low environmental impact.

The uses of the organic fiber cord treated with the adhesive composition for organic fiber cords of the present invention are not particularly limited. However, since the adhesive composition has excellent adhesion to a rubber composition and can impart strength, durability, and the like to the rubber composition, the organic fiber cord may be used as a component of an organic fiber cord-rubber composite, which will be described later.
Furthermore, the organic fiber cord treated with the adhesive composition for organic fiber cords of the present invention may be made into a composite with particles, fibers, cloth, etc. of various materials.

<Organic fiber cord-rubber composite>
The organic fiber cord-rubber composite of the present invention uses an organic fiber cord that has been treated with the adhesive composition for organic fiber cords of the present invention.

The rubber constituting the organic fiber cord-rubber composite of the present invention is preferably a coating rubber composition that coats the organic fiber cord treated with the adhesive composition for organic fiber cords of the present invention. In addition, the coating rubber composition is preferably made by blending a compounding agent that is commonly used in the rubber industry with the rubber component.

Here, the rubber component of the coating rubber composition is not particularly limited, and examples thereof include natural rubber, conjugated diene synthetic rubbers such as polyisoprene rubber (IR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR), as well as ethylene-propylene copolymer rubber (EPM), ethylene-propylene-diene copolymer rubber (EPDM), and polysiloxane rubber. Among these, natural rubber and conjugated diene synthetic rubber are preferred. These rubber components may be used alone or in combination of two or more.

Additionally, compounding agents commonly used in the rubber industry may include vulcanizing agents, fillers such as carbon black, silica, and aluminum hydroxide, vulcanization accelerators, antioxidants, softeners, etc., and can be mixed as appropriate.

The vulcanizing agent includes, but is not limited to, thiralium polysulfide compounds such as tetramethylthiralium disulfide and dipentamethylenethiralium tetrasulfide, 4,4-dithiomorpholine, p-quinone dioxime, p,p'-dibenzoquinone dioxime, cyclic sulfur imide, peroxide, etc. The vulcanizing agent is preferably sulfur because of its high vulcanization efficiency.

The uses of the organic fiber cord-rubber composite of the present invention are not particularly limited, but it may be used as a component for belts, air springs, hoses, etc.

<Tires>
The tire of the present invention uses the organic fiber cord-rubber composite of the present invention.

The tire of the present invention includes components such as a carcass ply, a belt layer, a belt reinforcing layer, and a belt surrounding reinforcing layer such as a flipper, and also includes a tire in which the organic fiber cord-rubber composite of the present invention is used for these components.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

Organic fiber cord-rubber composites were created using various adhesive compositions for organic fiber cords of the present invention that do not contain resorcin in order to reduce the environmental impact, and their adhesive strength, etc. were measured and compared with comparative examples.

<Components of adhesive composition for organic fiber cords>
<<Ingredients, sources, and usage forms>>
The ingredients used to prepare the adhesive compositions for organic fiber cords evaluated and examined, their sources and forms of use are shown in Table 1.

<<Mixing ratio>>
In each of the adhesive compositions for organic fiber cords evaluated, the blending ratio of each of the above-mentioned blended components when the total weight is taken as 100 is as follows (each mass % value is the mass % when each blended component is blended as a liquid or solid in the liquid treatment liquid that is each adhesive composition for organic fiber cords):

When the components are mixed as shown in Table 2, the mass percentage of each component as a ratio of the solid content in the dry matter of each adhesive composition for organic fiber cords is as shown in Table 4 below.

<Preparation of adhesive compositions for organic fiber cords using a single-bath treatment system (Comparative Example 1 and Examples 1 to 4)>
(1) In order to dissolve the naphthalene compound having a hydrophilic functional group, 1 N NaOH, water, and 30% by mass ammonia water (these are (6) basic solutions) were added in this order and dissolved. Then, (2) the aldehyde compound was gradually added in small amounts. The above addition was performed at a temperature of 40°C or higher and 60°C or lower while constantly stirring.
After stirring until (1) the naphthalene compound having a hydrophilic functional group and (2) the aldehyde compound were dissolved, the resin was aged at a resin aging temperature of 25°C for a resin aging time of 3 hours to form a naphthalene-aldehyde resin.
To the naphthalene-aldehyde resin solution that had been subjected to the above-mentioned prescribed resin aging, (4) latex was added while stirring at room temperature (ambient temperature) of 27±1° C., and the adhesive composition was then aged for 24 hours at 27±1° C. Elastron BN77 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added as an isocyanate compound to the aged naphthalene-aldehyde resin solution and latex mixed solution while stirring, to obtain each one-bath treatment solution.

<Preparation of adhesive compositions for organic fiber cords using two-bath treatment system (Examples 5 to 8)>
<<Preparation of the first bath processing solution of the two-bath processing system>>
The first bath treatment solution of the two-bath treatment system was an aqueous solution containing (3) 1 mass % of Denacol EX614B (manufactured by Nagase Chemtec Corporation) as an epoxy compound, and (5) 3 mass % of Elastron BN77 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as an isocyanate compound (Examples 5 to 8). Note that the above values of mass % are the mass % of the ratio when each component is mixed as a liquid or solid in the liquid of the first bath treatment solution.

<<Preparation of second bath processing solution of two-bath processing system>>
(1) In order to dissolve the naphthalene compound having a hydrophilic functional group, 1 N NaOH, water, and 30% by mass ammonia water (these are (6) basic solutions) were added in this order and dissolved. Then, (2) the aldehyde compound was gradually added in small amounts. The above addition was performed at a temperature of 40°C or higher and 60°C or lower while constantly stirring.
After stirring until (1) the naphthalene compound having a hydrophilic functional group and (2) the aldehyde compound were dissolved, the resin was aged at a resin aging temperature of 25°C for a resin aging time of 3 hours to form a naphthalene-aldehyde resin.

(4) Latex was added to the naphthalene-aldehyde resin solution that had been aged to the above-mentioned specified resin temperature while stirring at room temperature (ambient temperature) of 27±1°C, and the adhesive composition was then aged at 27±1°C for 24 hours to obtain each second bath treatment solution.

<Treatment of organic fiber cords with adhesive compositions for organic fiber cords in a single-bath treatment system (Comparative Example 1, Examples 1 to 4)>
After stirring the components in each of the first bath treatment solutions to uniformly disperse them, an organic fiber cord (PET cord for tires) with a cord fineness of 1670 dtex/2, a first twist number of 39 times/10 cm, and a final twist number of 39 times/10 cm was immersed in each of the first bath treatment solutions, and then the solvent in the first bath treatment solution attached to the PET cord for tires was dried, and a bonding treatment was performed by heating to obtain a PET cord for tires that had been bonded with the first bath treatment solution. Here, the drying treatment conditions were a dry temperature of 160°C and a dry time of 60 seconds, and the bonding treatment conditions by heating were a hot temperature of 245°C and a hot time of 120 seconds.

<Treatment of organic fiber cord with adhesive composition for organic fiber cord in two-bath treatment system (Examples 5 to 8)>
<<Treatment of organic fiber cord with first bath treatment solution in a two-bath treatment system>>
After stirring the components in each of the first bath treatment solutions to uniformly disperse them, an organic fiber cord (PET cord for tires) with a cord fineness of 1670 dtex/2, a first twist number of 39 times/10 cm, and a final twist number of 39 times/10 cm was immersed in each of the first bath treatment solutions, and then the solvent in the first bath treatment solution adhering to the PET cord for tires was dried, and a bonding treatment was performed by heating to obtain a PET cord for tires that had been bonded with the first bath treatment solution. Here, the drying treatment conditions were a dry temperature of 160°C and a dry time of 80 seconds, and the bonding treatment conditions by heating were a hot temperature of 205°C and a hot time of 60 seconds.

<<Treatment of organic fiber cord with second bath treatment solution in a two-bath treatment system>>
The PET cord for tires that had been subjected to the adhesion treatment using each of the first bath treatment liquids was immersed in each of the second bath treatment liquids, and then the solvent in the second bath treatment liquid adhering to the PET cord for tires was dried, followed by adhesion treatment by heating to obtain a PET cord for tires having the structure shown in Fig. 1. Here, the drying treatment conditions were a dry temperature of 160°C and a dry time of 80 seconds, and the adhesion treatment conditions by heating were a hot temperature of 245°C and a hot time of 60 seconds.

<Preparation of organic fiber cord-rubber composite>
A tire PET cord that had been subjected to the above-mentioned first bath treatment liquid and second bath treatment liquid adhesion treatment was embedded in an unvulcanized rubber composition containing a rubber component consisting of natural rubber and a styrene-butadiene copolymer, carbon black, and a crosslinking agent, and this was used as a test piece and vulcanized at 160°C for 20 minutes under a pressure of 20 kgf/ ^cm2 . The obtained vulcanizate (tire cord-rubber composite) was cooled to 23°C.

<Evaluation of Adhesive Strength>
The tire cord was excavated from the tire cord-rubber composite, and the resistance when peeling the tire PET cord from the tire cord-rubber composite at a speed of 30 cm/min was measured at room temperature (ambient temperature) of 23±1° C. as the adhesive strength of the adhesive composition for organic fiber cords.

<Evaluation of Adhesion State of Covering Rubber>
The tire PET cord was peeled off from the tire cord-rubber composite, and the state of adhesion of the coating rubber was visually observed, and the result was scored according to Table 3 below.

<Adhesion evaluation results>
The adhesive strength of the adhesive composition for organic fiber cords and the adhesion state of the coating rubber for Comparative Example 1 and Examples 1 to 8 are shown in Table 4 below.

The results in Table 4 show that when the adhesive composition for organic fiber cords according to the present invention, which does not contain resorcin and is more favorable for the environment and working environment, is used in a one-bath processing system (Examples 1 to 4) or a two-bath processing system (Examples 5 to 8), (1) the adhesive composition for organic fiber cords according to the present invention is superior in the evaluation of adhesive strength and adhesion state of the coated rubber compared to the adhesive composition for organic fiber cords (Comparative Example 1) in a one-bath processing system that does not contain a naphthalene compound having a hydrophilic functional group.

From the above, the present invention relates to the "compound:
(1) a naphthalene compound having a hydrophilic functional group, and (2) an aldehyde compound,
"An adhesive composition for organic fiber cords, comprising
It was confirmed that this adhesive composition for organic fiber cords has a low environmental impact because it does not contain resorcinol and also has good adhesive properties.

According to the present invention, there are provided an adhesive composition for organic fiber cords that does not contain resorcin, which has a low environmental impact and good adhesion, a method for producing the adhesive composition for organic fiber cords, and organic fiber cords, rubber reinforcing members (organic fiber cord-rubber composites), and tires that use the adhesive composition. The present invention can be used in industries that manufacture rubber articles such as tires.

1: Organic fiber cord treated with adhesive composition for organic fiber cord (adhesive-coated fiber)
2: Organic fiber cord 3: Adhesive layer of adhesive composition for organic fiber cords 10: Organic fiber cord treated with adhesive composition for organic fiber cords (adhesive-coated fiber)
11: Adhesive layer formed by first bath treatment liquid 12: Adhesive layer formed by second bath treatment liquid

Claims (13)

The following compound:
(1) a naphthalene compound having a hydrophilic functional group, and (2) an aldehyde compound,
An adhesive composition for organic fiber cords, comprising: Features:
(A) comprising a first bath processing solution and a second bath processing solution;
(B) the first bath treatment liquid is a composition containing (3) an epoxy compound, and (C) the second bath treatment liquid is a composition containing (1) a naphthalene compound having a hydrophilic functional group and (2) an aldehyde compound.
The adhesive composition for organic fiber cords according to claim 1 , having The adhesive composition for organic fiber cords according to claim 1, further comprising (4) latex. The adhesive composition for organic fiber cords according to claim 2, further comprising (4) latex in the second bath treatment liquid. The adhesive composition for organic fiber cords according to any one of claims 1 to 4, wherein the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having a hydroxyl group. The adhesive composition for organic fiber cords according to any one of claims 1 to 4, wherein the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having two or more hydroxyl groups. The adhesive composition for organic fiber cords according to any one of claims 1 to 4, wherein the (1) naphthalene compound having a hydrophilic functional group is a naphthalene compound having hydroxyl groups at the 1-position and 4-position (para-position) of the naphthalene skeleton. The adhesive composition for organic fiber cords according to any one of claims 1 to 7, further comprising (5) an isocyanate compound. The adhesive composition for organic fiber cords according to any one of claims 3 to 8, wherein the (4) latex contains at least one selected from the group consisting of natural rubber (NR), polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), halogenated butyl rubber, acrylonitrile-butadiene rubber (NBR), and vinylpyridine-styrene-butadiene copolymer rubber (Vp). The following steps:
(a) (1) a step of dissolving a naphthalene compound having a hydrophilic functional group in a basic solution to obtain a solution a; and (b) a step of dissolving an aldehyde compound in the solution a and aging the solution to obtain a solution b.
A method for producing the adhesive composition for organic fiber cords according to any one of claims 1 to 9, comprising: An organic fiber cord treated with the adhesive composition for organic fiber cords according to any one of claims 1 to 9. An organic fiber cord-rubber composite using the organic fiber cord according to claim 11. A tire using the organic fiber cord-rubber composite according to claim 12.

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