JPH06248166A - Tubular molded object and multilayered tubular molded object - Google Patents

Abstract

PURPOSE:To improve wearing resistance and high-temp. oil resistance by molding a resin composition comprising a specific polyester amide resin and a polycarbodiimide. CONSTITUTION:Polyester-forming monomers comprising an aliphatic dicarboxylic acid represented by formula I (wherein (n) is 0-10), an aliphatic diol, and 0.1-30 mol% at least either of a dihydroxy compound represented by formula II (wherein R<1> and R<2> each is an alkylene, (p) is 3 or 4, and (q) and (r) each is an integer of 0, 1 or larger) and a monohydroxy compound represented by formula III (wherein R<3> is an alkylene, (t) is 2 or 3, and (m) is an integer of 0, 1 or larger) are reacted with 5-60wt.% polyamide having a reduced viscosity of 1.8-7.0 and a degree of swelling in a 1/1 (by weight) solvent mixture of toluene and isooctane (16-day immersion at room temp.) of 5.0 or lower in terms of weight change. Thus, a polyester amide resin is obtained. 0.1-5.0 pts.wt. polycarbodiimide is incorporated into 100 pts.wt. this resin. This resulting mixture is molded into a tube.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an elastomeric tubular molded article formed of a predetermined polyesteramide resin composition and excellent in high temperature oil resistance, and abrasion resistance and high temperature oil resistance obtained by using the composition. TECHNICAL FIELD The present invention relates to a multi-layer tubular molded product having excellent properties.

[0002]

2. Description of the Related Art Elastomeric tubular moldings represented by hoses and tubes are used in many fields such as daily necessities, automobiles and machines. As a kind of such a tubular molded body, a suspension of an automobile or a motorcycle,
2. Description of the Related Art Cover boots having a bellows shape for protecting drive parts such as a steering wheel and a drive system are used. For example, constant velocity joint boots, rack and pinion boots, strut suspension boots, and the like.

Conventionally, rubber such as chloroprene has been used as a material for the tubular molded body such as the cover boot. However, since such a rubber is poor in durability, a thermoplastic elastomer has been used instead of the rubber. As such an oil resistant rubber composition,
For example, Japanese Examined Patent Publication (Kokoku) No. 62-34264 proposes an oil-resistant rubber composition suitable for a fuel hose or the like, which is obtained by crosslinking a high molecular weight composition containing an alkoxyalkyl acrylate, acrylonitrile and polyester as constituent components.
However, the oil resistance at high temperature is not sufficient and a crosslinking step is required, which is not preferable in terms of process. Further, as a known technique, a resin composition has been proposed in which a plasticizer is blended with a nylon resin and which is flexible and has excellent oil resistance, but when used in oil or a chemical, the plasticizer is extracted. There is a problem of hardening. At present, polyester elastomers are generally used in parts where heat resistance is strongly required.

By the way, a hydraulic oil such as grease is often used in order to improve the operability of the tubular molded body, especially in the drive section where the cover boot is used. Therefore, this hydraulic oil adheres to the inner surfaces of these members. Therefore, the tubular molded body, especially the cover boot material, is required to have high temperature oil resistance. An example of using the above thermoplastic elastomer in a cover boot is disclosed in
64-87973 discloses a cover boot in which a base layer is formed using a polyester elastomer, and a coating layer made of a polyurethane elastomer is formed on the surface of the base layer to prevent hydraulic oil from coming into contact with the base layer. There is. However, the above publication does not improve the oil resistance of the polyester elastomer itself.

Further, in Japanese Patent Application No. 4-164784, we have used a flexible, oil-resistant, cover boot, etc.
We have already proposed a tubular molded body with excellent wear resistance.
This tubular molded article is a multilayer tubular molded article having a polyester-based elastomer having a specific polyparaphenylene skeleton as a hard segment and an aliphatic polyester as a soft segment as an inner layer and a polyurethane resin as an outer layer. It is flexible and has excellent oil resistance and abrasion resistance, but its oil resistance at high temperatures is considerably improved, but it is still insufficient.

[0006]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned drawbacks, and uses an elastomer-like tubular molded article which is made of a predetermined material and is excellent in oil resistance at high temperature, as well as wear resistance of the material. Another object of the present invention is to provide a multi-layer tubular molded product having excellent high temperature oil resistance.

[0007]

The present inventors have prepared a polyesteramide resin by introducing a polyamide segment into a polyester by polymerizing a polyamide-forming monomer having the structure shown below and capable of forming a polyester. The inventors have found that the above-mentioned problems can be solved by using a resin composition in which polycarbodiimide is blended, and have completed the present invention.

The tubular molded article of the present invention is a resin containing 100 parts by weight of a polyester amide resin obtained by reacting a polyester-forming monomer with a polyamide, and 0.1 to 5.0 parts by weight of polycarbodiimide. A tubular molded article molded using the composition, wherein the monomer capable of forming a polyester comprises an aliphatic dicarboxylic acid represented by the following general formula [I], an aliphatic diol, and the following general formula [II ] And / or a monohydroxy compound represented by the following general formula [III], and the content of the hydroxy compound in which the dihydroxy compound and the monohydroxy compound are combined forms the polyester. 0.1 to 30 mol% with respect to all possible monomers, and the reduced viscosity of the polyamide is 1.8 to 7.0 ( 98% sulfuric acid solution of g / dL, a 20 ° C.), toluene / isooctane = 1/1
(Weight ratio) The degree of swelling in a mixed solvent (room temperature, 16 days immersion) is 5.0% or less in weight change ratio, and the ratio of the polyamide component in the polyamide resin is 5 to 65% by weight:

[0009]

[Chemical 4]

(In the formula, n represents an integer of 0 to 10)

[0011]

[Chemical 5]

(In the formula, R ¹ and R ² each independently represent an alkylene group, p is 3 or 4, and q and r each independently represent 0 or an integer of 1 or more)

[0013]

[Chemical 6]

(In the formula, R ³ represents an alkylene group, t is 2 or 3, and m represents an integer of 0 or 1 or more).

The multi-layer tubular molded article of the present invention comprises, as a soft segment, an inner layer formed of the above resin composition; and at least one selected from the group consisting of polyadipate, polylactone, polycarbonate and polyol.
The number average molecular weight of the soft segment is 400 to 6000.
And the content ratio of the soft segment is 40 to 8
It has an outer layer formed of an elastomer consisting of thermoplastic polyurethane, which is 0% by weight.

A raw material for the polyesteramide resin contained in the resin composition used for the tubular molded article of the present invention,
Examples of the dicarboxylic acid capable of forming polyester include
For example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid and sebacic acid are preferably used. When a dicarboxylic acid having more than 10 carbon atoms is used,
The physical properties of the molded product using the obtained polyesteramide deteriorate.

Examples of the aliphatic diol include glycol and polyalkylene oxide. Examples of glycols among the above aliphatic diols include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,
Examples include 3-diol, cyclohexane-1,4-diol, and cyclohexane-1,4-dimethanol.

Examples of the polyalkylene oxide of the above aliphatic diols include polyethylene oxide, polypropylene oxide, polytetramethylene oxide,
An example is polyhexamethylene oxide. The number average molecular weight of the polyalkylene oxide is 100 to 20,000.
Is preferable, and more preferably 500 to 5,000. When it is too small, the ability to impart flexibility to the polyesteramide produced is reduced, and when it is too large, physical properties such as thermal stability are reduced.

In the dihydroxy compound represented by the above formula [II], the alkylene groups R ¹ and R ² are preferably ethylene groups or propylene groups, and q and r are preferably 0 or 1. For example, 4,4 ″ -dihydroxy-p-terphenyl represented by the following formula [IV] and 4,4 ″ ′-dihydroxy-p represented by the following formula [V]
-Quarterphenyl and 4,4 '''-di (2-hydroxyethoxy) -p-quarterphenyl represented by the following formula [VI] are preferably used.

[0020]

[Chemical 7]

[0021]

[Chemical 8]

[0022]

[Chemical 9]

The melting point of the above 4,4 ″ -dihydroxy-p-terphenyl [IV] is 260 ° C.
That of -dihydroxy-p-quaterphenyl [V] is 336 ° C, and that of 4,4 '"-di (2-hydroxyethoxy) -p-quaterphenyl [VI] is 4
It is 03 degreeC. For example, 4,4 "'-dihydroxy-
p-Quarterphenyl is a Journal of Chemical Socie
ty, 1379-85 (1940).

The glycols, polyalkylene oxides and dihydroxy compounds [II] may be used alone or in combination of two or more.

Since the dihydroxy compound [II] has high crystallinity and [IV] to [VI] have high melting points as described above, when these dihydroxy compounds [II] are incorporated in the polymer chain, Polymers show unique properties. That is, a strong physical crosslink is formed even when the amount of the dihydroxy compound [II] is small. As a result, it is presumed that a thermoplastic elastomer having excellent heat resistance and mechanical strength can be obtained.

The monohydroxy compound represented by the above general formula [III] is a rigid low molecular weight compound having a paraphenylene skeleton, and its melting point is extremely high, reflecting its characteristic molecular structure. Therefore, when the above-mentioned monohydroxy compound [III] is incorporated into the polymer terminal, very strong physical crosslinking is brought about.

In the monohydroxy compound represented by the above general formula [III], R ³ is preferably an ethylene group or a propylene group, and m is preferably 0 or 1. Examples of the monohydroxy compound include 4-hydroxy-p-terphenyl, 4-hydroxy-p-quaterphenyl, 4- (2-hydroxyethoxy) -p-terphenyl and 4- (2-hydroxyethoxy)-. An example is p-quarterphenyl. The above monohydroxy compounds [III] may be used alone or in combination of two or more.

The polyester-forming monomer containing at least the aliphatic dicarboxylic acid [I], the aliphatic diol, and the dihydroxy compound [II] and / or the monohydroxy compound [III] is further composed of two hydroxyl groups. It may contain at least one kind of a poly-silicone having ## STR3 ##, a lactone and an aromatic hydroxycarboxylic acid.

The above-mentioned polysilicone has two hydroxyl groups. It is preferable that the two hydroxyl groups are located at the ends of the molecule. For example, polydimethylsiloxane, polydiethylsiloxane having one hydroxyl group at each end of the molecule,
Examples include polydiphenylsiloxane. The number average molecular weight of the polysilicone is preferably 100 to 20,000, more preferably 500 to 5,000. When it becomes smaller, the ability to impart flexibility to the formed polyesteramide decreases, and when it becomes larger, it becomes difficult to form polyesteramide.

The lactone ring-opens and reacts with a carboxyl group and a hydroxyl group to add an aliphatic chain and impart flexibility to the polyesteramide. As such a lactone, one having 4 or more carbon atoms in the ring is preferably used, and more preferably a 5-membered to 8-membered ring. For example, ε-caprolactone, δ-valerolactone, γ-
Examples include butyrolactone, enanthlactone, and caprylolactone.

As the aromatic hydroxycarboxylic acid, salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 3-
Bromo-4-hydroxybenzoic acid, 3-methoxy-4-
Hydroxybenzoic acid, 3-methyl-4-hydroxybenzoic acid, 3-phenyl-4-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 4-hydroxy-4′-carboxybiphenyl and the like can be mentioned, preferably, Para-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid and 4-hydroxy-4'-carboxybiphenyl.

Furthermore, in order to improve the mechanical properties of the resulting resin composition, the above polyester amide contains at least one of aromatic diol and aromatic dicarboxylic acid other than dihydroxy compound [II] as a constituent component. It may be contained.

As aromatic diols other than the dihydroxy compound [II], hydroquinone, resorcin, chlorohydroquinone, bromohydroquinone, methylhydroquinone, phenylhydroquinone, methoxyhydroquinone,
Phenoxyhydroquinone, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether,
4,4'-dihydroxydiphenyl sulfide, 4,
4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, bisphenol A, 1,1-di (4-
Examples thereof include hydroxyphenyl) cyclohexane, 1,2-bis (4-hydroxyphenoxy) ethane, 1,4-dihydroxynaphthalene and 2,6-dihydroxynaphthalene.

Examples of the aromatic dicarboxylic acid include metal salts of terephthalic acid, isophthalic acid, 5-sulfoisophthalic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxylic acid. Carboxydiphenyl sulfide, 4,4'-dicarboxydiphenyl sulfone, 3,3'-dicarboxybenzophenone, 4,4'-dicarboxybenzophenone, 1,2
-Bis (4-carboxyphenoxy) ethane, 1,4-
Examples thereof include dicarboxynaphthalene and 2,6-dicarboxynaphthalene.

As the monomer capable of forming a polyester used in the present invention, the above dihydroxy compound [II] is used.
In the case of using an aliphatic diol and an aliphatic dicarboxylic acid, the content of the hydroxy compound [II] is 0.1 to 0.1% based on all monomers capable of forming a polyester.
It is 30 mol%, preferably 2.0 to 10 mol%. When the content of the dihydroxy compound [II] decreases, the oil resistance and heat resistance of the obtained polyesteramide decrease, and when the content of the dihydroxy compound [II] increases, the elastic modulus increases and the flexibility decreases, which is used for an elastomeric tubular molded article. Would be unsuitable for.

When a polymer type diol such as polyalkylene oxide or polysilicone is used as a monomer capable of forming a polyester, its constitutional unit is counted as one monomer. That is, the degree of polymerization is 10
Polyethylene oxide is counted as 10 monomers.

When the above-mentioned monohydroxy compound [III], an aliphatic diol and an aliphatic dicarboxylic acid are contained as monomers capable of forming a polyester, the content of the above-mentioned hydroxy compound [III] can form a polyester. 0.1 to 30 mol% of all monomers,
It is preferably 2.0 to 10 mol%. When the content of the monohydroxy compound [III] is small, the oil resistance and heat resistance of the obtained polyesteramide are deteriorated, and when the content is large, the molecular weight is not sufficiently increased and becomes physically inferior.

When the above-mentioned dihydroxy compound [II], monohydroxy compound [III], aliphatic diol and aliphatic dicarboxylic acid are contained as the monomer capable of forming a polyester, the dihydroxy compound [II] and the monohydroxy compound [ The content of the hydroxy compound including III] is 0.1 to 30 mol% in all monomers capable of forming a polyester, and preferably 2.0 to 10 mol%.
Mol%. When the content of the hydroxy compound is low, the oil resistance and heat resistance of the obtained polyesteramide are lowered, and when it is high, the flexibility is lowered,
A sufficient increase in molecular weight cannot be obtained. In this case, the ratio of the dihydroxy compound [II] and the monohydroxy compound is preferably in the range of 0 <[III] / ([II] + [III]) <2/3.

The molecular weight of the above polyesteramide is preferably 0.8 to 2.0 when expressed by the intrinsic viscosity (in o-chlorophenol, 30 ° C.). If less than 0.8,
High temperature oil resistance is insufficient, and if it exceeds 2.0, molding becomes difficult.

The polyesteramide composed of the above-mentioned constituents can be produced by adding a polyamide during the reaction according to the following generally known polycondensation method for any polyester.

A method of directly reacting a dicarboxylic acid with a diol component (which includes an aliphatic diol, a dihydroxy compound, a polyalkylene oxide, an aromatic hydroxycarboxylic acid, a monohydroxy compound and the like).

A method of reacting a lower ester of dicarboxylic acid and a diol component by transesterification.

A method of reacting a dicarboxylic acid halide and a diol component in a suitable solvent such as pyridine.

A method of reacting a metal alcoholate of a diol component with a halide of a dicarboxylic acid.

A method in which an acetylated diol component and a dicarboxylic acid are reacted using transesterification.

In the polycondensation, a catalyst generally used in producing polyester may be used. As this catalyst, lithium, sodium, potassium, cesium, magnesium, calcium, barium,
Metals such as strontium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium and manganese, organic metal compounds thereof, organic acid salts, metal alkoxides, metal oxides and the like can be mentioned. .

Particularly preferred catalysts are calcium acetate, diacyl stannous tin, tetraacyl stannic tin, dibutyltin oxide, dibutyltin dilaurate, dimethyltin malate,
Examples include tin dioctanoate, tin tetraacetate, triisobutylaluminum, tetrabutyl titanate, germanium dioxide, and antimony trioxide. Two or more kinds of these catalysts may be used in combination.

Further, in order to improve thermal stability during polymerization,
Stabilizers may be used. For example, 1,3,5-trimethyl-2,4,6-tris- (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- [3- (3- t-butyl-4-hydroxy-5-
Besides hindered phenolic antioxidants such as methylphenyl) -propionyloxy] -1,1-dimethylethyl] 2,4,8,10-tetraoxaspiro [5,5] undecane, for example, tris ( 2,4-di-t-butylphenyl) phosphite, trilaurylphosphite, 2-t-butyl-α- (3-t-butyl-4-hydroxyphenyl) -p-cumenylbis (p-nonylphenyl) phosphite Fight, dimyristyl-3,3'-thiopropionate, distearyl-3,3'-thiodipropionate, pentaerythrityl tetrakis (3-laurylthiopropionate), ditridecyl-3,3'-thiodipronate Examples of heat stabilizers such as pionate.

During the reaction, water, alcohol, glycol and the like, which are by-products of the polymerization, are efficiently distilled off,
To obtain a high molecular weight polymer, the reaction system was
It is preferable to reduce the pressure to mmHg or less. The reaction temperature is generally 150 ° C to 350 ° C.

Further, during the polymerization, the dihydroxy compound [II]
It is also possible to regulate the structure of the resulting polyesteramide by changing the addition order of For example,
When a dihydroxy compound and a dicarboxylic acid and other diol components are charged together, a random copolymer is easily obtained, and the dihydroxy compound [I
When I] is charged, a block copolymer can be easily obtained. Further, the polyester amide synthesized in advance is kneaded with the dihydroxy compound [II] or the acetylated product of the dihydroxy compound under reduced pressure heating, and a segment based on the dihydroxy compound [II] is introduced into the molecular chain by deethylene glycol or transesterification reaction. It is also possible.

The polyamide used in the present invention has a amide bond in the polymer main chain and can be melted by heating, and has a reduced viscosity of 1.8 to 7.0 (1 g / d).
L in 98% sulfuric acid at 20 ° C.) and any degree of swelling in a toluene / isooctane = 1/1 (weight ratio) mixed solvent of 5.0% or less by weight change can be used. . For example, 4-nylon, 6-nylon, 6,6
-Nylon, 11-Nylon, 12-Nylon, 6,1
Aliphatic nylon such as 0-nylon and 6,12-nylon, isophthalic acid, terephthalic acid, metaxylylenediamine, 2,2-bis (paraaminocyclohexyl) propane, 4,4′-diaminodicyclohexylmethane,
2,2,4-trimethylhexamethylenediamine, 2,
Examples thereof include polyamides obtained by polycondensing aromatic, alicyclic and side chain-substituted aliphatic monomers such as 4,4-trimethylhexamethylenediamine. If the reduced viscosity is less than 1.8, the strength will be insufficient, and if it is more than 7.0, the compatibility will decrease, such being undesirable.

The proportion of polyamide in the polyesteramide resin obtained by reacting the above-mentioned polyester-forming monomer with polyamide is 5 to 65% by weight. If it is less than 5% by weight, the chemical resistance is not sufficient,
When it is more than 65% by weight, rubbery properties and flexibility are insufficient.

The resin composition used in the present invention contains the above polyesteramide and polycarbodiimide.
By adding polycarbodiimide to the polyesteramide, it is possible to suppress a decrease in the molecular weight of the polyesteramide when used at high temperature. It is presumed that this is because polycarbodiimide reacts with the terminal carboxyl group of polyesteramide to seal it, or by connecting two terminal carboxyl groups to extend the molecular chain, thereby suppressing a decrease in molecular weight. The polycarbodiimide used in the present invention is a polycarbodiimide having an average of 2 or more carbodiimides per molecule. These polycarbodiimides may be aliphatic, alicyclic or aromatic. For example, poly (tolylcarbodiimide), poly (4,4'-diphenylmethanecarbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (1,3,5-triisopropylphenylene-2,4) -Carbodiimide). Two or more polycarbodiimides may be used in combination. The polycarbodiimide is contained in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the polyesteramide resin. If the addition amount is less than 0.1 parts by weight,
The strength of the obtained resin composition is insufficient. On the contrary, if the amount is more than 5.0 parts by weight, the physical properties of the obtained molded article are adversely affected, and the elongation is particularly insufficient.

As a method for molding the composition containing the above polyesteramide and polycarbodiimide to obtain the tubular molded article (including cover boot) of the present invention, molding methods such as extrusion molding, injection molding and blow molding are used. be able to. In particular, an extrusion molding method using an extrusion blow molding machine is suitable.

A single-screw or twin-screw extruder is used for extrusion. Since the temperature control of the barrel is important, an extruder in which the heater is divided into three or more regions is preferable.
More preferably, a cooling system is provided. The L / D ratio (ratio of the effective length of the screw to the outer diameter) of the screw portion of the extruder is preferably about 20 to 25. Furthermore, in order to prevent the decomposition of the resin composition during molding, it is desirable that the resin composition be sufficiently dried before being subjected to molding. The molding temperature depends on the resin composition, but is 170-240 on the hopper side of the barrel.
C., 180 to 265.degree. C. in the middle part and the tip part, and the die temperature is preferably about 170 to 250.degree.

When injection molding is carried out, in order to prevent decomposition reaction during molding, the molding temperature is set so as not to become too high and the residence time in the cylinder becomes short. The molding temperature depends on the composition of the resin, but is 170 to 240 ° C. on the hopper side of the cylinder, and 18 at the middle part and the nozzle part.
The temperature is preferably 0 to 265 ° C., and the mold temperature is 20 to 8
The temperature is preferably 0 ° C. Blow molding conditions are based on extrusion and injection molding.

In this way, a tubular molded body is obtained using the resin composition containing the above polyesteramide resin and polycarbodiimide. Examples of the molded body include a normal cylindrical tube-shaped molded body, a bellows-shaped molded body, and a molded body partially having a bellows-shaped structure. A molded body having a bellows-like structure in part is commonly used as a cover boot. FIG. 1 shows a side view of the cover boot of the present invention.
The cover boot 1 is a molded body having a bellows portion 2 in a part thereof. The cover boot 1 may be entirely formed of the bellows portion 2.

Furthermore, it is possible to produce a multi-layer tubular molded product using the above resin composition as an inner layer. In this case, an elastomer made of thermoplastic polyurethane is used for the outer layer.

The characteristics of the thermoplastic polyurethane elastomer used for the above-mentioned multi-layer tubular molded article are that it has good bending resistance, abrasion resistance and flexibility.

The above-mentioned thermoplastic polyurethane elastomer has a polymer chain composed of diisocyanate and short-chain glycol as a hard segment, and a polymer chain composed of diisocyanate and a long-chain polyol or an aliphatic polyester as a soft segment. .

To introduce the above hard segment into the molecule, for example, diisocyanate such as 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate, ethylene glycol, 1,4-butanediol and bisphenol A are used. Short chain glycols such as

Examples of the aliphatic polyester for introducing the soft segment include polylactone, polyethylene adipate, polybutylene adipate and polycarbonate ester.

The number average molecular weight of the long-chain polyol and the aliphatic polyester is preferably 400 to 6000,
0 to 3000 is particularly preferable. When it is less than 400, the resilience and flexibility of the polyurethane elastomer are insufficient. 6
If it exceeds 000, the mechanical strength becomes insufficient.

The proportion of the soft segment in the polyurethane elastomer is preferably 40 to 80% by weight. Four
If it is less than 0% by weight, impact resilience and flexibility are insufficient. 8
If it exceeds 0% by weight, mechanical strength is insufficient.

A known method can be used as a method for molding the multilayer tubular molded article of the present invention. For example, there is a method of molding a multi-layered tubular molded body composed of a polyester inner layer and a polyurethane outer layer by two-layer coextrusion, or a method of molding a polyester inner layer first and then extruding an outer layer using two extruders.

A single-screw or twin-screw extruder is used for extrusion. Since the temperature control of the barrel is important, an extruder in which the heater is divided into three or more regions is preferable.
More preferably, a cooling system is provided. The L / D ratio of the screw part of the extruder is preferably about 20 to 25. Further, in order to prevent decomposition during molding, it is desirable that the resin composition is sufficiently dried before being subjected to molding. When the inner layer is molded by extrusion and then the outer layer is molded by extrusion, the molding temperature at which the inner layer made of polyesteramide is extruded is 170 to 240 ° C. on the hopper side of the barrel, depending on the resin composition. 180 in the department
˜265 ° C., and die temperature of 170
It is preferably about 250 ° C.

The molding temperature for extruding the polyurethane resin is
150 to 175 ℃ on the hopper side of the barrel, 165 to 195 ℃ at the middle and tip, and the die temperature is 170 to 210 ℃.
A degree is preferable.

[0068]

EXAMPLES The present invention will be described below based on examples. Various physical properties were measured using the following methods.

Intrinsic Viscosity [η] It was measured at 30 ° C. in an o-chlorophenol solvent using an Ubbelohde viscosity tube.

Surface Hardness The surface hardness was measured with a D type or A type durometer according to ASTM D2240.

(Synthesis of Polyesteramide Resin Composition 1) 2925 g (20 mol) of adipic acid, 2980 g (48 mol) of ethylene glycol, 4,4 ″ ′-dihydroxy-p-quaterphenyl (hereinafter referred to as DHQ) 508 g (1 0.5 mol), and 6-nylon (manufactured by Toyobo Co., Ltd., T842, 1 g / dL 98% sulfuric acid solution, reduced viscosity at 20 ° C., 2.2) in a mixture of 3000 g, and 2 g of germanium dioxide as a catalyst, 1,3,5-Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) as a stabilizer
4 g of benzene and 4 g of tris (2,4-di-t-butylphenyl) phosphite were added, and the reaction system was put under nitrogen.
The esterification reaction was carried out by keeping the temperature at 200 ° C. for 3 hours. Next, this reaction system was heated to 300 ° C. in 30 minutes, kept in this state at normal pressure for 10 minutes, and then cooled to 270 ° C.
As a result of carrying out the polycondensation reaction for 1 hour under a reduced pressure of 1 mmHg or less, a pale yellow resin (polyesteramide resin) was obtained. The yield of the obtained resin was 6842 g (ratio of the nylon component in the resin: 43.8% by weight). 2.0 parts by weight of poly (1,3,5-triisopropylphenylene-2,4-carbodiimide) (Sumitomo Bayer Urethane Co., Ltd., Starvacol P-100) as polycarbodiimide at 100 ° C. at 240 ° C. Were mixed and mixed using a twin-screw extruder to obtain a resin composition.

The polyesteramide resin composition thus obtained had an intrinsic viscosity [η] of 1.0 and a Shore D hardness of 51.

(Synthesis of Polyesteramide Resin Composition 2) Polymerization was carried out in the same manner as in Example 1 except that the amount of polyamide was 2000 g. The Shore D hardness of the obtained resin composition was 48.

(Synthesis of Polyesteramide Resin Composition 3) Polymerization was carried out in the same manner as in Example 1 except that 1000 g of polyamide was used in Example 1. The Shore D hardness of the obtained resin composition was 39.

(Synthesis of Polyesteramide Resin Composition 4) Polymerization was carried out in the same manner as in Example 1 except that 4000 g of polyamide was used in Example 1. The Shore D hardness of the obtained resin composition was 56.

(Synthesis of Polyesteramide Resin Composition 5) Same as Example 1 except that 3484 g of dimethyl adipate was used in place of adipic acid, 3000 g of polyamide was used, and 4.4 g of calcium acetate was used. Was polymerized. The Shore D hardness of the obtained resin composition was 52.

(Synthesis of Polyesteramide Resin Composition 6) Polymerization was carried out in the same manner as in Example 1 except that the polyamide was not added in Example 1. The Shore D hardness of the obtained resin composition was 28.

(Synthesis of Polyesteramide Resin Composition 7) Polymerization was carried out in the same manner as in Example 1 except that 150 g of polyamide was used in Example 1. The Shore D hardness of the obtained resin composition was 30.

(Synthesis of Polyesteramide Resin Composition 8) Polymerization was carried out in the same manner as in Example 1 except that the amount of polyamide was 8000 g. The obtained resin composition had a Shore D hardness of 64 and lacked flexibility.

(Synthesis of Polyurethane 1) 4,4-Diphenylmethane diisocyanate (MDI) 550 g (2.
2 mol), polytetramethylene oxide glycol (number average molecular weight 1500) 1500 g (1 mol) and 1,4-butylene glycol 90.12 g (1 mo)
1) was charged into a glass container, reacted at 70 ° C. for 3 hours under a nitrogen stream, and then reacted at 120 ° C. for 10 hours to obtain a white elastic body. Obtained Resin Shore A
The hardness was 83 and the tensile breaking strength was 400 kg / cm ² .

(Synthesis of Polyurethane 2) Polyurethane was obtained in the same manner as in the synthesis of Polyurethane 1, except that polycaprolactone (terminal hydroxyl group, number average molecular weight 1500) was used instead of polytetramethylene oxide glycol. The obtained resin had a Shore A hardness of 82 and a tensile breaking strength of 380 kg / cm ² .

(Synthesis of Polyurethane 3) Polyurethane was obtained in the same manner as in the synthesis of Polyurethane 1, except that polybutylene adipate (terminal hydroxyl group, number average molecular weight 1500) was used instead of polytetramethylene oxide glycol. The Shore A hardness of the obtained resin is 83,
The tensile strength at break was 390 kg / cm ² .

(Example 1) Molding of tubular molding and evaluation of oil resistance test The above polyesteramide resin composition 1 was extruded by a uniaxial extruder using a hose mold having an inner diameter of 10 mm and an outer diameter of 14 mm to mold a hose. did. Mold temperature is 23
The temperature was 5 ° C, the barrel part was 215 to 220 ° C on the hopper side, and the intermediate part and the tip part were 230 to 235 ° C.

As a test for oil resistance, this hose was
Cut to length and fill JIS hose oil inside the hose,
Both sides were sealed with silicone stoppers and placed in a gear oven at 130 ° C. After 60 days, it was cooled to room temperature, the oil was extracted, and then the surface state bent at 90 degrees was visually observed. The results are shown in Table 1.

Molding of Cover Boot and Evaluation of Oil Resistance Test Using the above polyesteramide resin composition 1, a cover boot as shown in FIG. 1 was molded by a blow molding machine. The molding temperature was such that the mold temperature was 235 to 240 ° C, the barrel part was 215 to 220 ° C on the hopper side, and the intermediate part and the tip part were 230 to 235 ° C.

The obtained cover boot is indicated by A in FIG.
Has an outer diameter of 93 mm, an outer diameter of B is 30 mm, a bellows portion has a maximum peak portion of 105 mm, a minimum peak portion of 70 mm, a maximum trough portion of 72 mm, a minimum trough portion of 50 mm, and an average wall thickness of 1.
It was 3 mm.

This cover boot was heated at 130 ° C. for 60 days,
It was immersed in JIS No. 3 oil. After the immersion, the bellows part was stretched horizontally so that it was flat, and the occurrence of cracks was observed using a 10 × magnifying glass. The results are shown in Table 1.

Example 2 Using the polyesteramide resin composition 2, a tubular molded body and a cover boot were molded in the same manner as in Example 1 and the same test was conducted. The results are shown in Table 1.

Example 3 Using the polyesteramide resin composition 3, a tubular molded body and a cover boot were molded in the same manner as in Example 1 and the same test was conducted. The results are shown in Table 1.

(Example 4) Using the polyesteramide resin composition 4, a tubular molded body and a cover boot were molded in the same manner as in Example 1 and the same test was conducted. The results are shown in Table 1.

Example 5 Using the polyesteramide resin composition 5, a tubular molded body and a cover boot were molded in the same manner as in Example 1 and the same test was conducted. The results are shown in Table 1.

Comparative Example 1 Using the polyesteramide resin composition 6, a tubular molded body and a cover boot were molded in the same manner as in Example 1 and the same test was conducted. The results are shown in Table 1.

Comparative Example 2 Using the polyesteramide resin composition 7, a tubular molded body and a cover boot were molded in the same manner as in Example 1 and the same test was conducted. The results are shown in Table 1.

Comparative Example 3 Using the polyesteramide resin composition 8, a tubular molded body and a cover boot were molded in the same manner as in Example 1 and the same test was conducted. The results are shown in Table 1.

[0095]

[Table 1]

* Crack generation after oil resistance test (after 130 ° C., 60 days) Comparative Example 3 lacks flexibility.

(Example 6) Molding of multi-layered tubular molded product The polyesteramide resin composition 1 was extruded by a uniaxial extruder using a hose mold having an inner diameter of 20 mm and an outer diameter of 22 mm to form an inner hose layer. . The molding temperature was 240 ° C. for the mold and 235 to 240 ° C. for the cylinder part. Next, the inner layer was continuously passed through a hose mold having an inner diameter of 24 mm and an outer diameter of 26 mm, and the outer layer of polyurethane 1 was extruded. The molding temperature was 170 to 175 ° C for the mold and 165 to 170 ° C for the cylinder portion. As a result, a multi-layer hose having a polyester inner layer and a polyurethane outer layer was obtained.

Evaluation of Oil Resistance Test The oil resistance test was carried out in the same manner as in Example 1. As a result, there was no crack and rubber elasticity was maintained.

Abrasion resistance test This hose was cut into a width of 1 cm and a length of 5 cm to prepare a test piece. This test piece was fixed to a test stand, and a wear test was conducted using a CS-17 wear wheel (load 1 kg). The rotation speed of the wear wheel was 60 times / minute, and the test was performed 1000 times. The amount of resin scraped off was 0 mg. H-2 on the wear wheel
When 2 was used, the amount of resin scraped off was 15 mmg. The above results are shown in Table 2.

(Examples 7 to 12) With the combinations shown in Table 2,
In the same manner as in Example 6, a multilayer hose having a resin composition inner layer and a polyurethane outer layer was obtained, and the same test as in Example 6 was performed. The results are shown in Table 2.

Comparative Examples 4 to 8 Using the resin compositions shown in Table 2, a hose was obtained by using a mold having an inner diameter of 20 mm and an outer diameter of 24 mm. The molding temperature was 240 ° C. for the mold and 235 to 240 ° C. for the cylinder part. Using the obtained hose,
The same test as in Example 6 was performed. The results are shown in Table 2.

Evaluation of Oil Resistance Test An oil resistance test was conducted in the same manner as in Example 1. The results are shown in Table 2.

Abrasion resistance test An abrasion resistance test was conducted in the same manner as in Example 6. The results are shown in Table 2.

[0104]

[Table 2]

* Oil resistance test, 130 ° C, 60 days

[0106]

EFFECTS OF THE INVENTION According to the present invention, a monomer capable of forming a polyester having a high crystallinity and a high melting point of a segment based on a dihydroxy compound or a monohydroxy compound is introduced in the presence of a polyamide. By using a resin composition containing a polyester amide having a specific polyester segment and a polyamide segment; and polycarbodiimide obtained by the method, an elastomeric tubular molded article having excellent heat resistance and oil resistance, for example, a tubular molded article or You can get cover boots. Furthermore, the multi-layer tubular molded product of the present invention having the above composition as an inner layer and polyurethane as an outer layer is excellent in abrasion resistance, heat resistance and oil resistance.

[Brief description of drawings]

FIG. 1 is a side view of a cover boot obtained by the present invention.

[Explanation of symbols]

 1 cover boot 2 bellows

Continuation of front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location C08L 79:04) (72) Inventor Hiroki Kadomachi 1-11-3 Minamikasugaoka, Ibaraki-shi, Osaka (72) ) Inventor Daishiro Kishimoto 2-24-23 Mishimaoka, Ibaraki City, Osaka Sun Heights Mishimaoka 306

Claims (2)

[Claims] 1. A resin composition containing 100 parts by weight of a polyesteramide resin obtained by reacting a polyester-forming monomer with a polyamide and 0.1 to 5.0 parts by weight of a polycarbodiimide. A tubular molded article, wherein the monomer capable of forming a polyester is an aliphatic dicarboxylic acid represented by the following general formula [I], an aliphatic diol, and a dihydroxy compound represented by the following general formula [II] Compound and / or at least a monohydroxy compound represented by the following general formula [III], and the content of the hydroxy compound in which the dihydroxy compound and the monohydroxy compound are combined is based on all monomers capable of forming the polyester. 0.1 to 30 mol% and the reduced viscosity of the polyamide is 1.8 to 7.0 (1 g / dL
Of 98% sulfuric acid solution at 20 ° C.), the degree of swelling in a mixed solvent of toluene / isooctane = 1/1 (weight ratio) (room temperature, 16 days immersion) is 5.0% or less in weight change rate, The ratio of the polyamide component in the polyamide resin is 5
~ 65% by weight, tubular shaped body: (In the formula, n represents an integer of 0 to 10) (In the formula, R ¹ and R ² each independently represent an alkylene group, p is 3 or 4, and q and r each independently represent 0 or an integer of 1 or more.) (In the formula, R ³ represents an alkylene group, t is 2 or 3, and m represents an integer of 0 or 1 or more). 2. An inner layer formed from the resin composition according to claim 1, and at least one selected from the group consisting of polyadipate, polylactone, polycarbonate and polyol as a soft segment, A multilayer tubular molding having an outer layer formed of an elastomer made of thermoplastic polyurethane, having a number average molecular weight of 400 to 6000 and a content of the soft segment of 40 to 80% by weight.