JP4811531B2 - Refrigerant transfer hose - Google Patents

Description

  The present invention relates to a refrigerant transfer hose.

Since HFC134a currently used as a refrigerant for car air conditioners has a large global warming potential (GWP), HFO1234yf, which has a low global warming potential, is a promising candidate for a new refrigerant. . For example, Patent Document 1 has been proposed as a composition containing a refrigerant such as HFO1234yf and a lubricating oil.
Conventionally, a laminated structure of a resin and rubber having an innermost layer made of a polyamide resin material is generally used for a rubber hose for a car air conditioner in order to suppress permeation of the refrigerant.

JP 2009-74017 A

However, when the present inventor applied a refrigerant composition containing a fluorine-based compound having a double bond such as HFO-1234yf and a lubricating oil to a conventional rubber hose for a car air conditioner, a new refrigerant It was found that the innermost layer of the hose has low deterioration resistance (durability).
Then, an object of this invention is to provide the hose for refrigerant | coolant transfer which is excellent in the deterioration-resistant performance of an innermost layer.

  As a result of diligent research to solve the above problems, the present inventor has found that the innermost layer obtained by using a polyamide resin composition containing a polyamide and an acid acceptor has excellent deterioration resistance, and completed the present invention. I let you.

That is, this invention provides the following 1-12.
1. A refrigerant transfer hose having an innermost layer obtained by using a polyamide resin composition containing 0.5 to 20 parts by mass of an acid acceptor with respect to 100 parts by mass of polyamide.
2. 2. The refrigerant transfer hose according to 1 above, wherein the acid acceptor is at least one selected from the group consisting of hydrotalcite, magnesium oxide and calcium hydroxide.
3. 3. The refrigerant transfer hose according to 1 or 2, wherein the polyamide resin composition further contains a carboxyl group-containing modified polyolefin.
4). The above 1-3, wherein the polyamide is at least one selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 4-6, polyamide 6-6, polyamide 6-10, polyamide 6-12 and polyamide MXD6. The refrigerant transfer hose according to any one of the above.
5). 5. The refrigerant transfer hose as described in 3 or 4 above, wherein the amount ratio (mass ratio) of the polyamide and the carboxyl group-containing modified polyolefin is 90/10 to 50/50.
6). 6. The refrigerant transfer hose according to any one of 1 to 5, which is used for a refrigerant-containing composition containing a fluorine-based compound having a double bond as a refrigerant.
7). The fluorine compound is 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1,2,3, 7. The refrigerant transfer hose according to 6 above, which is at least one fluoropropene selected from the group consisting of 3-tetrafluoropropene and 3,3,3-trifluoropropene.
8). The refrigerant transfer hose according to any one of 1 to 7, wherein the polyamide resin composition further contains an acid sealing agent.
9. 9. The refrigerant transfer hose according to 8, wherein the acid sealing agent is at least one selected from the group consisting of a carbodiimide compound, an epoxy compound, an amine compound, an isocyanate compound, and an alcohol.
10. 10. The refrigerant transfer hose according to 9 above, wherein an epoxy equivalent of the epoxy compound is 140 to 3300 g / equivalent.
11. The refrigerant transfer hose according to any one of 8 to 10, wherein the amount of the acid sealing agent is 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyamide.
12 The refrigerant transfer hose according to any one of 1 to 11, wherein a rubber layer is provided on the innermost layer, a reinforcing layer is provided on the rubber layer, and an outer layer is provided on the reinforcing layer.

  The refrigerant transfer hose of the present invention is excellent in the deterioration resistance performance of the innermost layer.

FIG. 1 is a perspective view schematically showing an example of the refrigerant transfer hose of the present invention by cutting out each layer of the hose.

The present invention will be described in detail below.
The refrigerant transfer hose of the present invention is
It has an innermost layer obtained using a polyamide resin composition containing 0.5 to 20 parts by mass of an acid acceptor with respect to 100 parts by mass of polyamide,
A refrigerant transfer hose used for a refrigerant-containing composition containing a fluorine-based compound having a double bond as a refrigerant.

The refrigerant transfer hose of the present invention has an innermost layer having excellent deterioration resistance.
In the present invention, the deterioration resistance performance of the innermost layer means that the chemical deterioration of the resin due to the attack of a new refrigerant or chemical is suppressed.
Usually, a refrigerant-containing composition containing a refrigerant and lubricating oil is applied to the refrigerant transfer hose, and the refrigerant-containing composition passes through the refrigerant transfer hose. By using the refrigerant transfer hose for a long period of time, a small amount of water may permeate the refrigerant transfer hose and be mixed into the refrigerant-containing composition. Such mixing of water causes deterioration of the refrigerant-containing composition under high temperature use conditions, and an acidic component (for example, a component considered to be hydrofluoric acid) is generated from the refrigerant-containing composition, and the acidic component is transferred to the refrigerant. The present inventor believes that it acts as a catalyst for hydrolyzing the polyamide used in the innermost layer of the hose for use. Polyamide hydrolysis lowers the deterioration resistance of the innermost layer.
In the present invention, the acid acceptor can capture an acidic component. The acid acceptor can capture the acidic component by reacting with the acidic component.
The acid acceptor can suppress hydrolysis of the polyamide by capturing the acidic component. The present inventors consider that the innermost layer is excellent in deterioration resistance due to the suppression of the hydrolysis of the polyamide.

Further, the acid acceptor can capture the carboxylic acid present in the innermost layer and / or the acid generated by the hydrolysis of the lubricant such as the ester oil in the refrigerant-containing composition. The acid acceptor can capture the acid by reacting with the acid.
The acid is not particularly limited as long as it is a compound having at least one acid group (for example, carboxy group). Examples thereof include acids such as carboxylic acid, phosphoric acid and sulfonic acid; partial esters of acids. Partial esters include those having at least one acid group and at least one ester.
Specifically, the acid is generated, for example, by hydrolysis of a lubricant such as carboxylic acid present in the innermost layer or an ester oil contained in a refrigerant-containing composition applied to a refrigerant transfer hose. Examples include acids. Examples of the carboxylic acid present in the innermost layer include a carboxylic acid bonded to the end of the polyamide, and a carboxylic acid generated by hydrolysis of the polyamide under the influence of alteration of the refrigerant-containing composition.
The acid acceptor reacts with a carboxylic acid bonded to the terminal of the polyamide, an acid generated by hydrolysis of the polyamide under the influence of alteration of the refrigerant-containing composition, or an acid generated from the refrigerant-containing composition, It can suppress that a polyamide hydrolyzes. The present inventors consider that the innermost layer is excellent in deterioration resistance due to the suppression of the hydrolysis of the polyamide.
In addition, the said mechanism is a guess of this inventor, and even if a mechanism differs, it is in the scope of the present invention.

An example of a preferred embodiment of the refrigerant transfer hose of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the attached drawings.
FIG. 1 is a perspective view schematically showing an example of the refrigerant transfer hose of the present invention by cutting out each layer of the hose.
In FIG. 1, the refrigerant transfer hose 1 has an inner tube 6, a reinforcing layer 7 and an outer layer 9. The inner tube 6 has an innermost layer 3 and a rubber layer 5. A rubber layer 5 is provided on the innermost layer 3 (inner surface resin layer), a reinforcing layer 7 is provided on the rubber layer 5, and an outer layer 9 is provided on the reinforcing layer 7.

The refrigerant transfer hose of the present invention includes an inner tube, a reinforcing layer, and an outer layer, and the inner tube has one of the preferred embodiments including an innermost layer (inner surface resin layer) and a rubber layer.
The thickness of the innermost layer is preferably 0.05 to 0.3 mm from the viewpoint of being excellent in the deterioration resistance performance of the innermost layer and excellent in flexibility (flexibility of the innermost layer and the entire hose).
The thickness of the rubber layer is preferably 1.0 to 2.0 mm from the viewpoints of excellent fatigue resistance and excellent flexibility (flexibility of the rubber layer and the entire hose).
The thickness of the reinforcing layer is preferably 0.5 to 1.5 mm from the viewpoint of excellent fatigue resistance and excellent flexibility (flexibility of the reinforcing layer and the entire hose).
The thickness of the outer layer is preferably 0.5 to 1.5 mm from the viewpoint of excellent fatigue resistance and excellent flexibility (flexibility of the outer layer and the entire hose).

The innermost layer will be described below.
The innermost layer of the refrigerant transfer hose of the present invention is obtained using a polyamide resin composition containing 0.5 to 20 parts by mass of an acid acceptor with respect to 100 parts by mass of polyamide.

The acid acceptor is not particularly limited. For example, a metal compound, an inorganic microporous crystal, and hydrotalcite are mentioned.
Examples of the metal compound include Group II (Group 2 and Group 12) metal oxides, hydroxides, carbonates, carboxylates, silicates, borates, phosphites; Group III (Group 3 and 13) metal oxides, hydroxides, carboxylates, silicates, sulfates, nitrates, phosphates; Periodic Table Group IV (Groups 4 and 14) metals Examples thereof include oxides, basic carbonates, basic carboxylates, basic phosphites, basic sulfites, and tribasic sulfates.

  Specific examples of the metal compound include, for example, magnesium oxide (MgO, magnesia), calcium hydroxide, magnesium hydroxide, aluminum hydroxide, barium hydroxide, sodium carbonate, magnesium carbonate, barium carbonate, quicklime, slaked lime, calcium carbonate, Calcium silicate, calcium stearate, zinc stearate, zinc oxide, calcium phthalate, calcium phosphite, zinc white, tin oxide, lisage, red lead, lead white, dibasic lead phthalate, dibasic lead carbonate, stearic acid Examples thereof include tin, basic lead phosphite, basic tin phosphite, basic lead sulfite, and tribasic lead sulfate.

From the viewpoint that the acid acceptor is superior in deterioration resistance performance of the innermost layer (specifically, for example, mechanical properties of the innermost layer such as elongation at break are not easily lowered over a long period of time) and excellent in environmental safety. It is preferably at least one selected from the group consisting of hydrotalcite, magnesium oxide and calcium hydroxide.
Also, it is difficult to release halogen once caught, and it is more excellent in deterioration resistance of the innermost layer (specifically, the mechanical properties of the innermost layer such as elongation at break are not easily lowered over a long period of time), and is safe for the environment. Hydrotalcite is more preferable from the viewpoint that the polyamide resin composition is easily gelled and easily forms a film.

Hydrotalcite as an acid acceptor is not particularly limited. The hydrotalcite may be a natural product or a synthetic product. Specifically, for example,
Mg ₃ ZnAl ₂ (OH) ₁₂ CO ₃ .wH ₂ O (w represents a positive real number),
_{Mg x Al y (OH) 2x} + 3y-2 CO 3 · wH 2 O ( where x is 1 to 10, y is 1 to 10, w represents a positive real number.),
_{Mg x Al y (OH) 2x} + 3y-2 CO 3 [ where x is 1-10, y represents 1 to 10. Specifically, for example, Mg _4.3 Al ₂ (OH) _12.6 CO ₃ (trade name DHT-4A-2, manufactured by Kyowa Chemical Industry Co., Ltd.)]
Mg _1-x Al _x O _3.83x (0.2 ≦ x <0.5. Specifically, for example, Mg _0.7 Al _0.3 O _1.15 (trade name KW-2200, manufactured by Kyowa Chemical Industry Co., Ltd.)).

A chemical reaction formula for catching halogen by reacting with hydrotalcite with an acid (for example, one containing halogen. Here, hydrofluoric acid will be described as an example) is shown below.
<Chemical reaction formula 1>
Mg _4.3 Al ₂ (OH) _12.6 CO ₃ + 2HF → Mg _4.3 Al ₂ (OH) _12.6 F ₂ + H ₂ O + CO ₂
<Chemical reaction formula 2>
Mg _0.7 Al _0.3 O _1.15 + 0.3HF + 0.85H ₂ O → Mg _0.7 Al _0.3 (OH) ₂ F _0.3

Halogen caught in the hydrotalcite and contained in the reaction product is not released from the reaction product unless the reaction product is heated to 450 ° C. or higher and decomposed.
The maximum use temperature of the hose for a car air conditioner is about 150 ° C. When the refrigerant transfer hose of the present invention is used for a car air conditioner, there is an advantage that the halogen once caught is not released again. Also from this point, it is preferable to use hydrotalcite as the acid acceptor.

Hydrotalcite among others, excellent by deterioration resistance performance of the innermost layer, a halogen catching capacity higher, those from the viewpoint of not generate water and carbon dioxide after halogen catch, OH amount included in the hydrotalcite is small, Mg _{1 -x} Al _x O _3.83x is preferred, and Mg _0.7 Al _0.3 O _1.15 is more preferred. Hydrotalcite having a small amount of OH in the chemical structure can be produced, for example, by calcining hydrotalcite obtained by synthesis at a higher temperature.

  A commercial item can be used as a hydrotalcite. Examples of commercial products of hydrotalcite include the DHT series (DHT-4A-2, DHT-4C) manufactured by Kyowa Chemical Industry Co., Ltd., the KW series manufactured by the same company (grades in which the DHT series is fired at a higher temperature, DHT, The halogen catching ability tends to be higher than the series, such as KW-2000, KW-2100, KW-2200), and STABIOCE HT series manufactured by Sakai Chemical Industry.

The acid acceptor may be a natural product or a synthetic product. In the case of a synthetic product, examples of its production method include conventionally known methods.
From the viewpoint that the halogen-accepting ability is high, the acid-accepting agent may not be surface-treated with, for example, fatty acids (including higher fatty acids), fatty acid esters, and the like.
The acid acceptors can be used alone or in combination of two or more.

In this invention, the quantity of an acid acceptor is 0.5-20 mass parts with respect to 100 mass parts of polyamides. In such a range, the innermost layer has excellent deterioration resistance, flexibility (low bending rigidity of the hose itself, good handling in the engine room), vibration resistance (vibration from the compressor for refrigerant compression) Is less likely to be transmitted to the car body and is less affected by vibration and noise in the car.)
In addition, the amount of the acid acceptor is 2 to 15 parts by mass with respect to 100 parts by mass of the polyamide from the viewpoint that the deterioration resistance of the innermost layer is superior and the flexibility (the flexibility of the innermost layer and the entire hose) is excellent. It is preferable that it is 3 to 15 parts by mass.

The polyamide will be described below.
In the present invention, the polyamide contained in the polyamide resin composition is not particularly limited.
The polyamide is selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 4-6, polyamide 6-6, polyamide 6-10, polyamide 6-12 and polyamide MXD6 from the viewpoint of excellent refrigerant permeation resistance. At least one is preferred.
Even when the polyamide resin composition contains a polyamide (for example, polyamide 6) that is easily hydrolyzed, the innermost layer of the refrigerant transfer hose of the present invention can exhibit excellent deterioration resistance.
Polyamides can be used alone or in combination of two or more.

In the present invention, the polyamide resin composition may further contain a carboxyl group-containing modified polyolefin. The polyamide resin composition is superior in deterioration resistance performance of the innermost layer, and further contains a carboxyl group-containing modified polyolefin from the viewpoint of flexibility (flexibility of the innermost layer and the entire hose), vibration resistance, and excellent affinity with polyamide. It is preferable to do this.
The carboxyl group-containing modified polyolefin is not particularly limited as long as it is a polyolefin having a carboxyl group. Further, the polyamide contained in the polyamide resin composition is a modified polyamide obtained by blending a polyamide and a carboxyl group-containing modified polyolefin.
The innermost layer (gas barrier layer) only needs to be made of a polyamide resin composition (for example, one of the preferred embodiments containing the above-mentioned modified polyamide), and within the range where the object of the present invention can be achieved. Other components (for example, additives) may be included. Thus, even if it contains other components, it is within the scope of the present invention.

  Examples of the carboxyl group-containing modified polyolefin include a functional group of about 0.1 by graft polymerization of an acid anhydride such as maleic anhydride to a polyolefin obtained by homopolymerizing or copolymerizing an olefin such as ethylene, propylene or butadiene, or a diene monomer. A modified polyolefin introduced at 10 mol% is preferably used.

  The amount ratio of polyamide and carboxyl group-containing modified polyolefin [polyamide / (carboxyl group-containing modified polyolefin), mass ratio] is 90/10 to 50 from the viewpoint of excellent flexibility (flexibility of the innermost layer and the entire hose). / 50 is preferable, and 85/15 to 65/35 is more preferable. When the ratio of the carboxyl group-containing modified polyolefin is 50% by mass or less, the refrigerant permeation resistance is excellent. When the ratio of the carboxyl group-containing modified polyolefin is 10% by mass or more, the flexibility (flexibility of the innermost layer and the entire hose) is excellent.

  Examples of the modified polyamide include a Zytel ST series such as Zytel ST801, Zytel ST811, and Zytel ST811HS manufactured by DuPont, which is considered to be an alloy (blend) of polyamide 6 and maleic anhydride-modified polyolefin.

  The innermost layer (gas barrier layer) can be formed by extruding the modified polyamide into a tubular shape, for example.

  The polyamide resin composition is superior in deterioration resistance performance of the innermost layer (specifically, for example, the mechanical properties of the innermost layer such as elongation at break are difficult to deteriorate), flexibility (the innermost layer and the entire hose) From the viewpoints of excellent flexibility), safety to the environment, hard release of halogens once caught, polyamide resin composition is difficult to gel, and easily forms a film. It is preferable to contain a site.

In the present invention, the polyamide resin composition may further contain an acid sealing agent.
When the polyamide resin composition further contains an acid sealing agent, the innermost layer is more excellent in resistance to deterioration.

In the present invention, the acid sealing agent can seal or capture the acid (hereinafter sometimes referred to as “sealing or the like”). An acid sealing agent seals an acid by reacting with an acid.
The acid is not particularly limited as long as it is a compound having at least one acid group (for example, carboxy group). For example, an acid such as carboxylic acid, phosphoric acid or sulfonic acid; when the acid has two or more acid groups, a partial ester thereof may be mentioned. The partial ester has at least one acid group and at least one ester.
Specific examples of the acid include a carboxylic acid present in the innermost layer and a carboxylic acid generated by hydrolysis of a lubricant such as an ester oil in a refrigerant-containing composition applied to a refrigerant transport hose. Carboxylic acids such as: phosphoric acid produced by hydrolysis of a phosphate ester-based additive contained in a lubricant; sulfonic acid.
Examples of the carboxylic acid present in the innermost layer include a carboxylic acid bonded to the end of the polyamide, and a carboxylic acid generated by hydrolysis of the polyamide under the influence of alteration of the refrigerant-containing composition.
As phosphoric acid, for example, a highly acidic phosphoric acid moiety produced by hydrolysis of an additive such as a triaryl phosphate ester contained in a lubricant such as an ester oil contained in a refrigerant-containing composition Examples include esters.
The acid sealing agent seals the carboxylic acid bonded to the end of the polyamide, and the carboxylic acid generated by hydrolysis of the polyamide under the influence of alteration of the refrigerant-containing composition, the acid generated from the refrigerant-containing composition. By sealing or capturing, the polyamide can be prevented from being hydrolyzed. The present inventors consider that the deterioration resistance of the innermost layer is more excellent by suppressing the hydrolysis of the polyamide.
Moreover, an acid sealing agent can capture | acquire the acidic component which arises from a refrigerant | coolant containing composition besides sealing an acid.
In addition, the said mechanism is a guess of this inventor, and even if a mechanism differs, it is in the scope of the present invention.

The acid sealing agent is not particularly limited as long as it is a compound capable of sealing an acid (including a partial ester). Further, for example, an acid generated from the refrigerant-containing composition can be captured.
Examples of the functional group capable of reacting with an acid included in the acid sealing agent include a carbodiimide group, an epoxy group, an amino group, an isocyanate group, and a hydroxy group.
Examples of the acid sealing agent include carbodiimide compounds, epoxy compounds, amine compounds, isocyanate compounds, and alcohols.
Among these, a carbodiimide compound and an epoxy compound are preferable from the viewpoint of being superior in deterioration resistance performance of the innermost layer.
Moreover, it is preferable that an acid sealing agent is a solid on normal temperature (23 degreeC) conditions from a viewpoint that it is excellent in handling.

From the viewpoint that the acid sealing agent can at least seal the carboxylic acid that the polyamide has, it is possible to at least seal the carboxylic acid (including the partial ester) as one of preferred embodiments. It is done.
In the present invention, an acid sealing agent that seals at least carboxylic acid is referred to as a “carboxylic acid sealing agent”.
Examples of the carboxylic acid sealing agent include carbodiimide compounds, epoxy compounds, amine compounds, isocyanate compounds, and alcohols.
When the acid sealant is a carboxylic acid sealant, the carboxylic acid sealant can seal phosphoric acid, sulfonic acid, and these partial esters in addition to carboxylic acid.
The following description regarding the acid sealant shall be applied to the carboxylic acid sealant.

The carbodiimide compound as the acid sealing agent is not particularly limited as long as it is a compound having a carbodiimide group (—N═C═N—). Examples thereof include polycarbodiimide and monocarbodiimide.
Among these, polycarbodiimide is preferable from the viewpoint of being superior in the deterioration resistance performance of the innermost layer.

  The polycarbodiimide that can be used in the present invention is not particularly limited as long as it has a plurality of carbodiimide groups in a molecular chain (for example, a polymer main chain). The polycarbodiimide can be obtained, for example, by condensing an arbitrary organic diisocyanate, and a known technique can be used for the method. For example, what is obtained by decarbonation gas condensation reaction of organic diisocyanate can be used.

Examples of polycarbodiimides include poly [1,1-dicyclohexylmethane (4,4-diisocyanate)] and a cyclohexylamine urea adduct.
As a commercially available product of polycarbodiimide, for example, “Carbodilite HMV-8CA”, “Carbodilite LA-1” manufactured by Nisshinbo Co., Ltd., which are fine granular polycarbodiimide compounds at room temperature, are easily available and easy to operate. It is mentioned as a preferable aspect in terms of surface.

  The monocarbodiimide that can be used in the present invention is not particularly limited as long as it has one carbodiimide group. Specifically, for example, dimethylcarbodiimide, diethylcarbodiimide, diisopropylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, di-t-butylcarbodiimide, dicyclohexylcarbodiimide, diphenylcarbodiimide, 2,2,6,6-tetra Examples include methyldiphenylcarbodiimide, 2,2,6,6-tetraethyldiphenylcarbodiimide, 2,2,6,6-tetraisopropyldiphenylcarbodiimide, and di-β-naphthylcarbodiimide.

The epoxy compound will be described below.
The epoxy compound as the acid sealing agent is not particularly limited as long as it is a compound having one or more epoxy groups.
Examples of the epoxy compound include an epoxy group-containing (meth) acrylic polymer, an epoxy group-containing polystyrene, a polymer containing an epoxy group such as epoxidized soybean oil; a glycidyl ester (including a polymer and a monomer); glycidyl ether ( Polymer and monomer).

The epoxy equivalent of the epoxy compound is preferably 140 to 3300 g / equivalent from the viewpoint that the deterioration resistance performance of the innermost layer is excellent and the composition hardly causes gelation.
When the epoxy compound is a polymer containing an epoxy group, the epoxy equivalent is preferably 170 to 3300 g / equivalent from the viewpoint that the deterioration resistance performance of the innermost layer is excellent and the composition is hardly gelled.
When the epoxy compound is a monomer containing an epoxy group, the epoxy equivalent is preferably 140 to 400 g / equivalent from the viewpoint that the innermost layer is more excellent in deterioration resistance and the composition hardly causes gelation.

Among these, an epoxy group-containing (meth) acrylic polymer and glycidyl ether (including a polymer and a monomer) are preferable from the viewpoint that the epoxy compound is superior in the deterioration resistance performance of the innermost layer and the composition hardly causes gelation. .
In addition, an epoxy group-containing (meth) acrylic polymer (especially solid at room temperature) is preferred from the viewpoint that the innermost layer is more excellent in resistance to deterioration and the composition hardly causes gelation.

The epoxy group-containing (meth) acrylic polymer will be described below.
The epoxy group-containing (meth) acrylic polymer as the acid sealing agent is not particularly limited as long as the main chain is a (meth) acrylic polymer and has at least one epoxy group.
In the present invention, (meth) acryl means one or both of acrylic and methacrylic.

The (meth) acrylic polymer as the main chain may be either a homopolymer or a copolymer.
Examples of the epoxy group-containing (meth) acrylic polymer include a methyl methacrylate / glycidyl methacrylate copolymer.

  The weight average molecular weight of the epoxy group-containing (meth) acrylic polymer is 5,000 to 300,000 from the viewpoint that the innermost layer is more excellent in resistance to deterioration, the composition is less prone to gelation, and is easy to handle. Is more preferable, and it is more preferable that it is 8,000-250,000.

  Epoxy group-containing (meth) acrylic polymers are, among other things, superior in deterioration resistance performance of the innermost layer, the composition is less susceptible to gelation, and is easy to handle, methyl methacrylate / glycidyl methacrylate copolymer Is preferred.

The glycidyl ether will be described below.
The glycidyl ether as the acid sealing agent is not particularly limited as long as it is a compound having a glycidyloxy group.
Examples of the glycidyl ether include butyl-glycidyl ether, 2-ethylhexyl glycidyl ether, stearyl-glycidyl ether, allyl-glycidyl ether, phenyl-glycidyl ether, butylphenyl-glycidyl ether, butoxy-polyethylene glycol-glycidyl ether, glycidol, glycerin. Epichlorohydrin-0 to 1 mol adduct-polyglycidyl ether, ethylene glycol-epichlorohydrin-0 to 2 mol adduct-polyglycidyl ether, polyethylene glycol-diglycidyl ether, neopentyl glycol-diglycidyl ether, trimethylolpropane -Polyglycidyl ether.

A commercial item can be used as an epoxy compound.
Commercially available epoxy group-containing (meth) acrylic polymers include, for example, Marproof G-0150M (acrylic polymer, powder, weight average molecular weight 8,000 to 10,000, epoxy equivalent 310 g / equivalent, NOF Corporation Manufactured), Marproof G-2050M (acrylic polymer, powder, weight average molecular weight 200,000-250,000, epoxy equivalent 340 g / equivalent, manufactured by NOF Corporation).
Examples of commercially available products of epoxy group-containing polystyrene include Marproof G-1010S (styrene polymer, powder, weight average molecular weight 100,000, epoxy equivalent 1,700 g / equivalent, manufactured by NOF Corporation).
Examples of commercially available products of epoxidized soybean oil include Neusizer 510R (manufactured by NOF Corporation).

An acid sealing agent can be used individually or in combination of 2 types or more, respectively.
The amount of the acid sealing agent is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyamide from the viewpoint that the deterioration resistance performance of the innermost layer is excellent and the composition is less likely to cause gelation. More preferably, it is 0.5-5 mass parts.
When the acid sealing agent is a carbodiimide compound, it is 0.1 to 2 parts by mass with respect to 100 parts by mass of polyamide from the viewpoint that the deterioration resistance of the innermost layer is superior and the composition hardly causes gelation. Is preferable, and it is more preferable that it is 0.3-1 mass part.
When the acid sealing agent is an epoxy compound, it is 0.1 to 10 parts by mass with respect to 100 parts by mass of polyamide from the viewpoint that the deterioration resistance performance of the innermost layer is excellent and the composition hardly causes gelation. Is preferable, and it is more preferable that it is 0.5-5 mass parts.

The total amount of the acid acceptor and the acid sealant is 3 to 20 parts by mass with respect to 100 parts by mass of the polyamide from the viewpoint that the deterioration resistance performance of the innermost layer is superior and the composition hardly causes gelation. Is preferable, and it is more preferable that it is 5-15 mass parts.
The amount ratio between the acid acceptor and the acid sealant is superior to the deterioration resistance performance of the innermost layer, and from the viewpoint that the composition hardly causes gelation, the acid sealant is contained in 100 parts by weight of the acid acceptor. It is preferable that it is 50-150 mass parts, and it is more preferable that it is 70-130 mass parts.

  The polyamide resin composition can contain additives as long as it does not impair the purpose of the present invention. Examples of the additive include a filler, a reinforcing agent, an anti-aging agent, a plasticizer, a pigment (dye), a tackifier, a lubricant, a dispersant, and a processing aid.

The production of the polyamide resin composition is not particularly limited. For example, the method of mixing polyamide and an acid acceptor and the acid sealing agent and / or additive which can be used as needed using a twin-screw kneading extruder is mentioned.
The mixing temperature is preferably 180 to 300 ° C, more preferably 200 to 280 ° C, from the viewpoint of excellent mixing processability.

The Young's modulus of a cured product (for example, a sheet) formed from the polyamide resin composition is preferably 300 MPa or less, and more preferably 270 MPa or less.
Further, the Young's modulus of the cured product after the test of immersing a cured product (for example, a sheet) formed from the polyamide resin composition in a refrigerant-containing composition containing water is preferably 300 MPa or less, and is 270 MPa or less. More preferably. When the Young's modulus of the cured product after the above immersion test is 300 MPa or less, the innermost layer is more excellent in resistance to deterioration and has flexibility (the hose itself has low bending rigidity and good handling in the engine room) and resistance. Excellent vibration characteristics (vibration from the compressor for compressing refrigerant is not easily transmitted to the body of the car and is less affected by vibration and noise in the car). When the Young's modulus of the cured product exceeds 300 MPa, the bending rigidity of the hose itself is increased, the handling performance in the engine room is poor, the vibration of the compressor for refrigerant compression is transmitted to the vehicle body side, and vibration and sound Problems are likely to occur.
In this invention, the Young's modulus of the hardened | cured material after an immersion test can be 300 Mpa or less because the quantity of the acid acceptor with respect to 100 mass parts of polyamides is 0.5-20 mass parts.

  In the present invention, the Young's modulus is a specimen prepared by preparing a sheet under the condition of 230 ° C. using a polyamide resin composition and cutting out a test piece having a width of 5 mm, a length of 80 mm, and a thickness of 0.15 mm from the sheet. Example 1) Next, the autoclave contains 50% by mass of a refrigerant-containing composition [HFO-1234yf (manufactured by Honeywell) as a refrigerant] containing water, and trade name: Atmos GU-10 as a lubricant. Putting 0.1 parts by mass of water to 100 parts by mass of the refrigerant-containing composition containing 50% by mass (manufactured by Nippon Oil Co., Ltd.) and the specimen 1 obtained as described above The immersion test was performed for 168 hours under heating and pressurization (calculated value: 7 MPa) at 150 ° C., and the obtained test specimens (test specimen 1 and specimen 2 in the example) were 50 mm / min. J at tensile speed It is those that have been measured in accordance with S K 7161.

The rubber layer will be described below.
In the present invention, the inner tube can have a rubber layer. When the inner tube has a rubber layer, the rubber layer is adjacent to the innermost layer.

The rubber composition used in the production of the rubber layer will be described below.
In the present invention, the rubber contained in the rubber composition is not particularly limited. Examples of rubber include acrylonitrile butadiene rubber (NBR), natural rubber (NR), butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), polyisoprene rubber (IR), butyl rubber (IIR), and chlorobutyl rubber. (Cl-IIR), bromobutyl rubber (Br-IIR), chloroprene rubber, ethylene-propylene copolymer rubber, styrene-isoprene copolymer rubber, styrene-isoprene-butadiene copolymer rubber, isoprene-butadiene copolymer rubber And chlorosulfonated polyethylene.

The rubber preferably contains butyl rubber (IIR) from the viewpoint of excellent fatigue resistance of the rubber layer and excellent permeation resistance.
The rubbers can be used alone or in combination of two or more.

  In the present invention, the rubber composition can contain additives as long as the purpose of the present invention is not impaired. Examples of additives include vulcanizing agents, vulcanization accelerators, fillers, reinforcing agents, anti-aging agents, vulcanization activators, plasticizers, pigments (dyes), tackifiers, lubricants, dispersants, and processing agents. Auxiliaries are mentioned.

  In the present invention, the rubber composition is not particularly limited for its production. For example, a method of mixing (kneading) rubber and an additive that can be used as necessary using an open roll, a kneader, an extruder, a universal stirrer, and a batch kneader.

The reinforcing layer will be described below.
Since the refrigerant transfer hose of the present invention has a reinforcing layer, it can maintain strength and is excellent in pressure resistance and metal fitting tightening fixing force.

The material of the reinforcing layer that the refrigerant transfer hose of the present invention can have is not particularly limited.
Examples of the material used for the reinforcing layer include polyester fiber, polyamide fiber, aramid fiber, vinylon fiber, rayon fiber, PBO (polyparaphenylene benzobisoxazole) fiber, polyketone fiber, polyarylate fiber, and polyketone fiber. Examples of such fiber materials include metal materials such as hard steel wires (for example, brass-plated wires, galvanized wires, etc.).

Of these, polyester fibers are preferred from the viewpoint of excellent fatigue resistance of the reinforcing layer and excellent cost performance with respect to predetermined required performance.
The reinforcing layer is not particularly limited with respect to its shape. For example, the thing of a blade shape and a spiral shape is mentioned.
The material of the reinforcing layer can be used alone or in combination of two or more.

The outer layer will be described below.
Since the refrigerant transfer hose of the present invention has the outer layer, the reinforcing layer can be protected and the moisture penetration resistance from the outside is excellent.

One preferred embodiment is that the outer layer that the refrigerant transfer hose of the present invention can have is a rubber layer.
The material of the outer layer that the refrigerant transfer hose of the present invention can have is not particularly limited. Examples of the material used for the outer layer include those similar to the rubber composition used for the rubber layer in the present invention, and other rubber compositions.
From the viewpoint of superior weather resistance, it is preferable to include an ethylene-propylene copolymer rubber, and from the viewpoint of excellent permeation resistance, it is preferable to include butyl rubber (IIR).

  The production of the refrigerant transfer hose of the present invention is not particularly limited. For example, a method of laminating an innermost layer, a rubber layer, a reinforcing layer and an outer layer in this order on a mandrel, and then vulcanizing and adhering these layers can be mentioned. Further, an adhesion treatment (for example, application of an adhesive, surface treatment to the innermost layer) can be performed between the innermost layer and the rubber layer. An adhesion treatment (for example, application of an adhesive) can be performed between the rubber layer and the reinforcing layer. When the outer layer is a rubber layer similar to the rubber layer of the inner tube, an adhesion treatment (for example, application of an adhesive) can be performed between the reinforcing layer and the outer layer.

In the present invention, the temperature of the polyamide resin composition when extruding the innermost layer is preferably 230 to 250 ° C. from the viewpoint of excellent workability.
The temperature during vulcanization is preferably 130 to 180 ° C. from the viewpoint of excellent rubber quality and economy.
The vulcanization time is preferably 30 to 120 minutes from the viewpoint of excellent rubber quality and economy.
Examples of the vulcanization method include press vulcanization, steam vulcanization, oven vulcanization (hot air vulcanization), and hot water vulcanization.

The refrigerant-containing composition that can be used for the refrigerant transfer hose of the present invention is not particularly limited. For example, the composition containing a refrigerant | coolant like a fluorine-type compound and a lubricant is mentioned.
Examples of the refrigerant contained in the refrigerant-containing composition include a fluorine-containing compound having a double bond; and saturated hydrofluorocarbons such as HFC-134a (structural formula: CF ₃ -CFH ₂ ).
Examples of the fluorine compound having a double bond include 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene. _{(formula: CF 3 -CF = CH 2,} HFO-1234yf), 1,2,3,3- tetrafluoropropene include fluoropropene such as 3,3,3-trifluoropropene.

  The innermost layer of the refrigerant transfer hose of the present invention is excellent in deterioration resistance against fluorine compounds having a double bond such as fluoropropene (particularly, a new refrigerant such as HFO-1234yf). Further, the deterioration resistance performance of the innermost layer is improved, so that the innermost layer is hardly broken when the refrigerant transfer hose is subjected to deformation or vibration, and the dynamic fatigue performance of the innermost layer is improved.

  The lubricating oil contained in the refrigerant-containing composition is not particularly limited. For example, a conventionally well-known thing is mentioned.

  The refrigerant transfer hose of the present invention is a hose that can be used to transfer a refrigerant, and can be applied to a fluid transport hose such as an air conditioner hose (for example, a car air conditioner). Moreover, the refrigerant | coolant transfer hose of this invention can be used for the hose for warm water (for temperature control apparatuses) other than the hose for an air conditioner.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
<Evaluation>
Using the test specimen obtained as described below, the immersion test and the tensile test are conducted by the following method, and the test specimen after the tensile strength (T _B ), elongation (E _B ), and immersion test of the test specimen is obtained. The state of was evaluated. The results are shown in Table 1.
1. Preparation of Specimen 1 A polyamide resin composition obtained as described below was prepared using an electrothermal press at 230 ° C., and the sheet was 5 mm wide, 80 mm long, and 0.15 mm thick. The test piece was cut out, and this was designated as test specimen 1.

2. Immersion test (deterioration acceleration test)
The autoclave contains a water-containing refrigerant-containing composition [HFO-1234yf (manufactured by Honeywell) as a refrigerant, 50% by mass, and a lubricant product name: Atmos GU-10 (manufactured by Nippon Oil Corporation), 50% by mass. And 0.1 parts by weight of water to 100 parts by weight of the refrigerant-containing composition] and the test body 1 obtained as described above were added, and heated and pressurized at 150 ° C. (calculated values) The immersion test was conducted for 168 hours under the condition of 7 MPa).
After the immersion test, the test body 1 is lifted from the refrigerant-containing composition containing water, and the test body obtained after the immersion test is taken as the test body 2.

3. Tensile test The tensile test was performed according to JIS K 7161, and the tensile strength (T _B ) and elongation (E _B ) at 23 ° C. were measured for the specimen 1 and specimen 2 obtained as described above. The tensile speed was 50 mm / min.

4). Evaluation of the state of the test body before and after the immersion test The test body 1 and the test body 2 obtained as described above were bent, and the state of the test body before and after the immersion test was evaluated.

5. Young's modulus (tensile modulus)
With respect to the specimen 2 obtained as described above, Young's modulus was measured according to JIS K 7161 at a tensile speed of 50 mm / min.

<Manufacture of polyamide resin composition>
Using each component shown in Table 1 in the amount (parts by mass) shown in the same table, these components were uniformly mixed using a biaxial kneading extruder to produce a polyamide resin composition.

Each component shown in Table 1 is as follows.
Polyamide (1): Blend of polyamide 6 and carboxyl group-containing modified polyolefin [trade name Zytel ST811HS, manufactured by DuPont]
Polyamide (2): Polyamide 11 (trade name RILSAN BESNO TL manufactured by ARKEMA Inc.)
Acid acceptor 1: Calcium hydroxide (slaked lime), manufactured by Iriko Lime Industry Co., Ltd. Acid acceptor 2: Magnesium oxide (Kyowa Mag 150), manufactured by Kyowa Chemical Industry Co., Ltd. Acid acceptor 3: Hydrotalcite (KW) -2200, manufactured by Kyowa Chemical Industry Co., Ltd.)
Acid acceptor 4: Hydrotalcite (DHT-4A-2, manufactured by Kyowa Chemical Industry Co., Ltd.)
Acid sealant 1: Methyl methacrylate / Glycidyl methacrylate copolymer (trade name Marproof G-2050M, weight average molecular weight 200,000-250,000, epoxy equivalent 340 g / equivalent, manufactured by NOF Corporation)

As is clear from the results shown in Table 1, Comparative Example 1 containing no acid acceptor became brittle after the immersion test and was inferior in deterioration resistance of the innermost layer. In Comparative Example 2 in which the amount of the acid acceptor was less than 0.5 parts by mass with respect to 100 parts by mass of polyamide, cracking occurred when bent after the immersion test, and the deterioration resistance of the innermost layer was poor. In Comparative Example 3 in which the amount of the acid acceptor exceeds 20 parts by mass with respect to 100 parts by mass of the polyamide, the cured product of the polyamide resin composition after the immersion test became too hard and the deterioration resistance of the innermost layer was inferior.
On the other hand, in Examples 1 to 11, the decrease in tensile strength (T _B ) and elongation (E _B ) of the test specimen is suppressed, and there is no cracking even after bending after the immersion test. Excellent resistance to deterioration as the innermost layer. After the immersion test, the decrease in tensile strength (T _B ) and elongation (E _B ) of the specimen was suppressed, and the specimens of Examples 1 to 11 (innermost layer) were not cracked even when bent. Indicates excellent deterioration resistance.
In Examples 1 to 11, the Young's modulus after the immersion test is in an appropriate range, the specimen is not too hard, and is excellent in flexibility (the flexibility of the innermost layer and the entire hose).
Further, in Example 8 containing an acid acceptor (hydrotalcite) having a smaller amount of OH than Example 10, the decrease in tensile strength (T _B ) and elongation (E _B ) of the test specimen was further suppressed. From this, it can be seen that hydrotalcite as the acid acceptor has a small amount of OH, and Mg _1-x Al _x O _3.83x is superior in the _{deterioration resistance} performance of the innermost layer.

[Example 12] <Manufacture of hose 1>
Using a resin extruder on the surface of a thermoplastic resin mandrel having an outer diameter of 11 mm, the innermost layer was extruded to a thickness of 0.15 mm with the polyamide resin composition of Example 1 (extrusion temperature 240 ° C.), and the surface was thick. A tube rubber layer with a thickness of 1.2 mm (butyl rubber composition A shown below) is extruded to form two reinforcing layers in which PET (polyethylene terephthalate) fibers having a total yarn amount of 80,000 dtex are alternately wound in a spiral shape. Then, a 1.0 mm thick cover rubber layer (the same composition as the butyl rubber-based composition A was used) was extruded on the surface to form an extruded outer layer. The pentene resin is extruded into an outer skin, and the resulting tubular laminate is vulcanized for 100 minutes at 160 ° C. Then, the outer sheath and mandrel are removed from the tubular laminate to produce a hose. It was.
The refrigerant transfer hose of Example 12 has the innermost layer of Example 1 that is excellent in deterioration resistance as described above.

  Butyl rubber composition A (both tube rubber and cover rubber): 100 parts by weight of butyl rubber, 80 parts by weight of carbon black (HAF), 3 parts by weight of stearic acid, 10 parts by weight of paraffin oil, 2 parts by weight of zinc oxide, and brominated alkylphenol A composition containing 8 parts by mass of formaldehyde resin.

[Example 13] <Manufacture of hose 2>
A hose 2 was produced by carrying out an experiment in the same manner as in Example 12 except that the polyamide resin composition of Example 1 was replaced with the polyamide resin composition of Example 7.
The refrigerant transfer hose of Example 13 has the innermost layer of Example 1 that is excellent in deterioration resistance as described above.

1 Refrigerant transfer hose 3 Innermost layer 5 Rubber layer 6 Inner tube 7 Reinforcement layer 9 Outer layer

Claims (13)

It has an innermost layer obtained using a polyamide resin composition containing 0.5 to 20 parts by mass of an acid acceptor with respect to 100 parts by mass of polyamide,
A refrigerant transfer hose used for a refrigerant-containing composition containing a fluorine-based compound having a double bond as a refrigerant.   The refrigerant transfer hose according to claim 1, wherein the acid acceptor is at least one selected from the group consisting of a metal compound, an inorganic microporous crystal, and hydrotalcite. The metal compound is
Periodic Table Group 2 and Group 12 metal oxides, hydroxides, carbonates, carboxylates, silicates, borates, phosphites,
Periodic Table Group 3 and Group 13 metal oxides, hydroxides, carboxylates, silicates, sulfates, nitrates, phosphates, and Periodic Table Group 4 and Group 14 metal oxides, basic The refrigerant transfer hose according to claim 2, which is at least one selected from the group consisting of carbonates, basic carboxylates, basic phosphites, basic sulfites, and tribasic sulfates.   The metal compound is magnesium oxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, barium hydroxide, sodium carbonate, magnesium carbonate, barium carbonate, quicklime, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, oxidation Zinc, calcium phthalate, calcium phosphite, tin oxide, lisage, red lead, dibasic lead phthalate, dibasic lead carbonate, tin stearate, basic lead phosphite, basic tin phosphite, basic The refrigerant transfer hose according to claim 2 or 3, which is at least one selected from the group consisting of lead sulfite and tribasic lead sulfate.   The refrigerant transfer hose according to claim 1, wherein the polyamide resin composition further contains a carboxyl group-containing modified polyolefin.   The polyamide is at least one selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 4-6, polyamide 6-6, polyamide 6-10, polyamide 6-12 and polyamide MXD6. The refrigerant transfer hose according to claim 5.   The fluorine compound is 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1,2,3, The hose for refrigerant transfer according to any one of claims 1 to 6, which is at least one fluoropropene selected from the group consisting of 3-tetrafluoropropene and 3,3,3-trifluoropropene.   The refrigerant transfer hose according to claim 1, wherein the polyamide resin composition further contains an acid sealing agent.   The refrigerant transfer hose according to claim 8, wherein the acid sealing agent is at least one selected from the group consisting of a carbodiimide compound, an epoxy compound, an amine compound, an isocyanate compound, and an alcohol.   The refrigerant transfer hose according to claim 9, wherein an epoxy equivalent of the epoxy compound is 140 to 3300 g / equivalent.   11. The refrigerant transfer hose according to claim 8, wherein an amount of the acid sealing agent is 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyamide.   The refrigerant transfer hose according to claim 1, wherein a rubber layer is provided on the innermost layer, a reinforcing layer is provided on the rubber layer, and an outer layer is provided on the reinforcing layer. The Young's modulus of the cured product after a test for immersing the cured product formed from the polyamide resin composition in the refrigerant-containing composition further containing water is 300 MPa or less. The refrigerant transfer hose as described.