JPH0615913B2 - Resin hose - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin hose, and more specifically, in a resin hose having a nylon tube, an organic fiber reinforced layer, and a thermoplastic resin cover, the adhesive interface of the nylon tube is To After treatment with an organic active halogen compound having (wherein X represents halogen), polytetramethylene glycol and 4,
A one-pack moisture-curable adhesive consisting of a urethane polymer having an isocyanate group / hydroxyl group equivalent ratio in a specific range obtained by reacting an isocyanate compound containing 4'-diphenylmethane diisocyanate as a main component, or this urethane prepolymer The present invention relates to a resin hose obtained by applying a one-component moisture-curable adhesive composed of a urethane prepolymer modified with a short-chain diol and adhering the nylon tube and the organic fiber reinforcing layer.

[Prior Art] A method for adhering a nylon tube made of 6-nylon or 6,6-nylon to an organic fiber reinforcing layer in a resin hose is to plasticize the surface of the nylon tube with a nylon solvent such as resorcin, formic acid, phenol, or methanol. To obtain structural adhesion by embedding an organic fiber reinforced layer, or when the nylon tube is especially 11-nylon, 12-nylon, etc., with a resin such as polyurethane that can easily obtain adhesiveness with a polar solvent. There is a method of performing co-extrusion and fusing with each other, while structurally adhering the polyurethane and the organic fiber reinforcing layer (Japanese Patent Publication No. 54-10367), and the like.

However, in the method using a nylon solvent such as resorcin, since the nylon solvent remains in the tube, the heat resistance is lowered, and 100 ° C is the limit of use. Further, since the nylon solvent is a powerful drug, it has a drawback that it is not easy to handle. On the other hand, in the method using polyurethane, the resin having poor heat resistance forms the surface layer of the tube, so the heat resistance is lowered, and 100 ° C is the limit particularly in terms of fitting of the metal fittings.

[Problems to be Solved by the Invention] An object of the present invention is to provide a resin hose in which a nylon tube and an organic fiber reinforcing layer have high adhesive strength and which is excellent in heat resistance.

[Means for Solving the Problems] As a result of earnest studies in accordance with this object, the present inventor has reacted polytetramethylene glycol having a specific molecular weight with an isocyanate compound containing 4,4′-diphenylmethane diisocyanate compound as a main component. One-component moisture-curable adhesive composed of a urethane polymer having an isocyanate group / hydroxyl group equivalent ratio within a specific range, or one-component moisture composed of a urethane prepolymer obtained by modifying this urethane prepolymer with a short-chain diol. By adhering the nylon tube and the organic fiber reinforced layer with a curable adhesive, it was found that the resin hose has high adhesiveness and the resin hose is also excellent in heat resistance.

By using this one-component moisture-curable adhesive (hereinafter simply referred to as adhesive), a nylon tube made of 6-nylon, 6,6-nylon or a copolymerized nylon thereof and an organic fiber reinforcement made of polyester fiber, etc. The layers can be adhered without heating. However, even if the above adhesive was used, the adhesion between the nylon tube made of 10-nylon, 11-nylon and 12-nylon and the organic fiber reinforcing layer was still insufficient.

As a result of further study, the present inventor treated 10-nylon, 11-nylon, 12-nylon by treating the adhesive interface of a nylon tube such as 10-nylon with an organic active halogen compound and then applying the above adhesive. The present inventors have found that the nylon tube and the organic fiber reinforcing layer adhere to each other with high adhesive strength, and have reached the present invention.

That is, the present invention provides a resin hose having a nylon tube, an organic fiber reinforced layer, and a thermoplastic resin cover, in which the adhesive interface of the nylon tube is in the molecule. After being treated with an organic active halogen compound having (wherein X represents halogen), polytetramethylene glycol having an average molecular weight of 700 to 1800 and an isocyanate compound having 4,4'-diphenylmethane diisocyanate as a main component are equivalent to isocyanate groups / hydroxyl groups. One-part moisture-curable adhesive composed of urethane prepolymer obtained by reacting so that the ratio becomes 1.3 to 2.0, or the urethane prepolymer having a short chain diol / polytetramethylene glycol molar ratio of 0.5 or less. A one-part moisture-curable adhesive composed of a urethane prepolymer modified with a short-chain diol so that the nylon tube and the organic fiber reinforcing layer are bonded to each other is a resin hose.

The nylon tube used in the present invention is not particularly limited, and examples thereof include 6-nylon, 6,6-nylon or copolymers thereof, or 10-nylon, 11-nylon, 12-nylon, etc., which will be described later. In addition, for nylon tubes such as 10-nylon, 11-nylon, and 12-nylon, it is not possible to obtain sufficient adhesive strength with the organic fiber reinforcing layer only by applying an adhesive, so treat the adhesive interface with an organic halogen compound. is necessary. As the organic fiber reinforcing layer, a braided polyester fiber or the like is used.

In the present invention, the adhesive interface of the nylon tube is Treat with an organohalogen compound having a bond. Examples of the organic halogen compound used here include halogenated succinimides such as N-bromosuccinimide, isocyanuric acid halides such as trichloroisocyanuric acid and dichloroisocyanuric acid, and halogenated hydantoin such as dichlorodimethylhydantoin. Among these, trichloroisocyanuric acid is preferable.

In such an organic halogen compound, it is preferable that the concentration of the organic halogen compound is set to 2 to 10% by using an appropriate soluble solvent such as methyl ethyl ketone or ethyl acetate as the organic solvent.

In the present invention, the nylon tube is treated with the organic active halogen compound at the adhesive interface and then coated with the adhesive.

The adhesive used here is a urethane polymer having an equivalent ratio of isocyanate group / hydroxyl group obtained by reacting polytetramethylene glycol with an isocyanate compound having 4,4′-diphenylmethane diisocyanate as a main component in a specific range, or This urethane prepolymer is composed of a urethane prepolymer modified with a short chain diol.

Polytetramethylene glycol (PTMG) is used as the polyol forming the urethane polymer. Among the polyols, PTMG moth has the best adhesion to the nylon tube to which it is bonded. In the present invention, a product obtained by modifying the end portion of PTMG with propylene oxide or the like can also be used. The average molecular weight of PTMG is
It is in the range of 700 to 1800, preferably 800 to 1700, and the adhesive using PTMG in this range has an adhesive force of 5 μl / in or more when nylon is adhered at room temperature. PT
If the average molecular weight of MG is less than 700 or more than 1800, the adhesive strength will decrease. The average molecular weight of this PTMG is a value calculated from the hydroxyl value.

On the other hand, as the isocyanate compound forming the urethane prepolymer, an isocyanate compound containing 4,4'-diphenylmethane diisocyanate as a main component is used.

There are various compounds containing an isocyanate group (-NCO), but among them, aliphatic isocyanate compounds are not suitable for moisture-curable adhesives because they react slowly with moisture in the atmosphere, and from the viewpoint of heat resistance. Even if you look at it, it is not enough. On the other hand, as the aromatic isocyanate compound, tolylene diisocyanate (TDI), bitolylene diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), 4,4′-diphenylmethane diisocyanate (MDI) and the like are used. Although it is widely used, TDI has a slow reaction with moisture in the atmosphere like aliphatic isocyanate compounds, is not suitable for moisture-curing adhesives, and NDI and TODI are expensive, so they are practical. Not. NDI lacks storage stability when used as an adhesive and is not practical.

Therefore, the adhesive used in the present invention has good reactivity with moisture in the atmosphere and good compatibility with the nylon tube. An isocyanate compound containing 4,4'-diphenylmethane diisocyanate as a main component (hereinafter referred to as MDI) is used. The MDI may be pure MDI having a high purity of about 100%, or a modified MDI partially decarboxylated and condensed, for example, Isonate 143 manufactured by Kasei Upjohn.
L or crude MDI represented by the following scientific formula However, hydrogenated MDI is not preferable in terms of health and safety.

In the present invention, the urethane polymer adhesive is prepared by substituting a part of MDI with TDI, TODI, NDI or an aliphatic isocyanate compound in order to adjust the curing rate, viscosity, cohesive force, physical properties, adhesiveness and the like. It is also possible to use.

The adhesive used in the present invention has a urethane prepolymer obtained by reacting PTMG and MDI with an isocyanate group / hydroxyl group equivalent ratio of 1.3 to 2.0, preferably 1.4 to
It is 1.9.

The urethane prepolymer obtained by reacting a polyol and an isocyanate compound usually has an isocyanate group /
It is obtained by reacting so that the equivalent ratio of hydroxyl groups is 1.9 to 2.5.

The moisture-curable adhesive has a curing mechanism in which a urea bond is formed by a reaction between moisture in the atmosphere and an isocyanate group to generate carbon dioxide gas. When a large amount of carbon dioxide is generated, or when carbon dioxide is generated rapidly, the escape of gas is delayed,
Air bubbles remain in the adhesive layer and sufficient adhesive force cannot be obtained. As a method of eliminating the bubbles, there are a method of reducing the isocyanate group in the prepolymer, that is, a method of reducing the gas generation amount, and a method of reducing the free MDI, that is, a method of reducing the sudden gas generation amount. In addition, addition of a carbon dioxide absorbent, a filler, a plasticizer, a solvent, etc. is also an effective method. Moisture-curing urethane prepolymer is free MDI
It is desirable that the amount be 1% or less based on the total amount of MDI. One method for reducing the amount of free MDI is to reduce the equivalent ratio of isocyanate group / hydroxyl group.
Further, the method of reducing the equivalent ratio is effective for reducing the active isocyanate groups. Therefore, in the present invention, the upper limit of the equivalence ratio is 2.0, preferably 1.9.

Further, if this equivalent ratio is made too small, the molecular weight of the urethane prepolymer becomes unnecessarily large, and an increase in viscosity cannot be avoided, making it difficult to handle as an adhesive, and reducing the active isocyanate groups and increasing the viscosity. As a result, the wettability with polyamide resin and the like deteriorates, and sufficient adhesive force cannot be obtained. Also, since the amount of free isocyanate groups is reduced, the amount of urea bonds generated during the curing reaction is reduced. Comparing the urethane bond and the urea bond, the urea bond contributes to the heat resistance, so that the decrease in the amount of the urea bond means the decrease in the heat resistance. Therefore, in the present invention, the lower limit of the equivalence ratio is 1.3, preferably 1.4.

In the adhesive used in the present invention, by further modifying the urethane prepolymer obtained as described above with a short-chain diol, a reaction as shown by the following formula proceeds and the adhesive force to the resin is improved. be able to.

_{OCN-R 1 -NCO + HO-} B-OH + OCN-R 2 -NCO → OCN-R 1 (In the above formula, HO-B-OH is a short chain diol, O
CH-R ₁ -NCO and OCH-R ₂ -NCO represent the above-mentioned urethane prepolymers respectively.) When this reaction formula is in progress, if free MDI is present, the short-chain diol reacts preferentially, The presence of short chain diols will also have the function of removing free MDI.

In carrying out this modification, the molar ratio of PTMG and short chain diol is important. That is, the presence of a short-chain diol was found to have an effect of improving the adhesive strength, and when the short-chain diol was increased, the adhesive strength was decreased.
As the MG molar ratio approaches 0.5, it does not change from the adhesive strength before modification. In the relationship between the two, the molecular weight of the prepolymer begins to increase as the molar ratio becomes sufficiently large and becomes a polymer in the vicinity of 1.0, so that the moisture curing function is lost.

Therefore, when modifying with a short chain diol, the molar ratio of short chain diol / PTMG is 0.5 or less, preferably 0.4 or less.

The short-chain diol used here is a diol having a molecular weight of at least about 400 such as ethylene glycol, 1,4-butanediol, diethylene glycol, beta-hydroxyethyl benzoate, and beta-hydroxyethyl terephthalate, and their modified products or mixtures. May be Among these short chain diols
Most preferred is 1,4-butanediol.

The adhesive used in the present invention thus obtained is a solvent that does not react with an isocyanate group, for example, a solvent such as methyl ethyl ketone (MEK), toluene, ethyl acetate, cellosolve acetate, thinner or hexane for degreasing and viscosity adjustment. It is desirable to use after diluting. Further, if desired, it is optional to add various additives.

As described above, in the resin hose of the present invention, the nylon tube and the organic fiber reinforcing layer made of polyester fiber or the like are bonded with high adhesive strength, and the obtained resin hose is excellent in heat resistance.

[Examples] Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples.

Examples 1 and 2 100 kg (76.9 mol) of PTMG (trade name PTG-300, manufactured by Nippon Polyurethane Industry Co., Ltd.) having an average molecular weight of 1300 was placed in a reaction kettle, and the temperature was adjusted to 50 ° C., and then 34.6 kg of pure MDI was added.
A rapid exothermic reaction was passed for 1 hour, and after the reaction was stopped, the reaction was further performed at 80 ° C. for 5 hours to obtain a urethane prepolymer.

10% by weight of dry methyl ethyl ketone was added to the urethane prepolymer thus obtained, and the mixture was stirred and uniformly mixed to obtain a one-component moisture-curable adhesive.

3% concentration of trichloroisocyanuric acid diluted with ethyl acetate was applied to the adhesive interface of each of the nylon tube made of 6 / 6,6 copolymer nylon and the tube made of 11-nylon with a brush, and the temperature was kept at 20 ° C for about 5 minutes. Then, it was naturally dried at 65% relative humidity to obtain a trichloroisocyanuric acid-treated nylon tube.

The above adhesive was applied to the outer circumference of the trichloroisocyanuric acid-treated nylon tube with a brush, and an organic fiber reinforcing layer braided with polyester fibers was placed and lightly pressed.

A peeling test was performed to evaluate the adhesive strength between the nylon tube and the organic fiber reinforcing layer. Peeling test is 20 ℃, 65%
After leaving it to stand for 7 days under the condition of relative humidity, the test was carried out at a tensile speed of 50 mm / min and a temperature of 20 ° C. The results are shown in Table 1.

After adhering the organic fiber reinforced layer to the nylon tube in this way, a urethane adhesive is further applied to the outer periphery of the organic fiber reinforced layer, a polyester thermoplastic resin cover is adhered, and a resin hose as shown in FIG. 1 is attached. Obtained.

In FIG. 1, 1 is a nylon tube, 2 is a one-component moisture-curable adhesive layer, 3 is an organic fiber reinforcing layer, 4 is a urethane adhesive layer, and 5 is a thermoplastic resin cover.

A high temperature impulse test was conducted on the resin hose thus obtained. The test was carried out in accordance with JIS B 83428.4, under the conditions of pressure 200 kgf / cm ² square wave, oil temperature 120 ° C., mounting U-shape, R = 50 mm. The results are shown in Table 1.

Comparative Example 1 A nylon tube made of 6 / 6,6 copolymerized nylon was plasticized at the adhesive interface with a nylon solvent, and an organic supplementary fiber strong layer was attached. A peeling test was conducted in the same manner as in Example 1 in order to evaluate the adhesive strength between the nylon tube and the organic reinforcing machine fiber layer. The results are shown in Table 1.

After the organic fiber reinforced layer was attached to the nylon tube in this way, a urethane adhesive was further applied to the outer periphery of the organic fiber reinforced layer, and a polyester thermoplastic resin cover was attached to obtain a resin hose.

A high temperature impulse test of this resin hose was conducted according to Example 1, and the results are shown in Table 1.

Comparative Example 2 An adhesive interface of a nylon tube obtained by coextruding 11-nylon and polyurethane was plasticized with a urethane solvent to bond an organic reinforcing fiber layer. A peeling test was conducted in the same manner as in Example 1 in order to evaluate the adhesive strength between the nylon tube and the organic reinforcing fiber layer. The results are shown in Table 1.

After adhering the organic fiber reinforcing layer to the nylon tube in this manner, a urethane adhesive was further applied to the outer periphery of the organic fiber reinforcing layer, and a polyester thermoplastic resin cover was adhered to obtain a resin hose.

A high temperature impulse test of this resin hose was conducted according to Example 1, and the results are shown in Table 1.

As shown in Table 1, the resin hoses of Examples 1 and 2 in which a nylon tube was treated with an organic active halogen compound and then a one-pack moisture-curing adhesive was applied to adhere to the organic fiber reinforcing layer were Compared to the resin hoses of Comparative Examples 1 and 2 used, the nylon tube and the organic fiber reinforced layer have excellent adhesiveness, and moreover have excellent heat resistance as a resin hose.

[Effects of the Invention] As described above, the resin hose of the present invention in which the nylon tube is treated with the organic active halogen compound, and then the one-part moisture-curing adhesive is applied to adhere to the organic fiber reinforcing layer,
Nylon tube and organic fiber reinforced layer can be bonded with high adhesive strength without being deformed by heat in a temperature range of about 80 ° C that does not give residual strain to the tube from low temperature,
In addition, since it has high heat resistance, it is particularly easy to mount metal fittings.
It can be used at high temperature of 10-120 ℃.

Therefore, the resin hose of the present invention can be used in various fields requiring heat resistance.

[Brief description of drawings]

 FIG. 1 is a schematic view showing the structure of the resin hose of the present invention. 1: Nylon tube, 2: One-component moisture-curable adhesive layer, 3: Organic fiber reinforcing layer, 4: Urethane adhesive layer, 5: Thermoplastic resin cover.

Claims (1)

[Claims] 1. A resin hose having a nylon tube, an organic fiber reinforced layer, and a thermoplastic resin cover, wherein the adhesive interface of the nylon tube is in the molecule. After being treated with an organic active halogen compound having (X represents halogen), polytetramethylene glycol having an average molecular weight of 700 to 1800 and an isocyanate compound containing 4,4'-diphenylmethane diisocyanate as a main component are converted into isocyanate groups / hydroxyl groups. A one-pack moisture-curable adhesive composed of a urethane prepolymer obtained by reacting so that the equivalent ratio becomes 1.3 to 2.0, or the urethane prepolymer has a short-chain diol / polytetramethylene glycol molar ratio of 0.5. A resin hose characterized by applying a one-part moisture-curable adhesive consisting of a urethane prepolymer modified with a short-chain diol as described below to bond the nylon tube and the organic fiber reinforcing layer.