JPH06240136A - Production of tubular molded article and multilayer tubular molded article - Google Patents

Abstract

PURPOSE:To produce a tubular molded article and a multilayer tubular molded article excellent in softness and chemical resistance at high temperature. CONSTITUTION:The tubular molded article is produced by dissolving 20-70wt.% of a polyamide having a reduced viscosity of 1.8-7.0g/dL at 20 deg.C in 98% sulfuric acid solution into a polyester compound consisting of aliphatic dicarboxylic acids mainly comprising adipic acid and aliphatic diols mainly comprising ethylene glycol and/or butylene glycol at a temperature of 150-230 deg.C to make a clear homogeneous solution, subjecting the obtained solution to polycondensation at 200-260 deg.C under reduced pressure to obtain a clear polyesteramide and molding the resin composition composed of 0.1-5.0 pts.wt. of a polycarbodiimide and 100 pts.wt. of this polyesteramide. A multilayer tubular molded article is obtained by forming an inner layer from this resin composition and the outer layer from a thermoplastic polyurethane containing a specific component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an elastomeric tubular molded article and a multilayer tubular molded article which are excellent in flexibility and chemical resistance at high temperature.

[0002]

2. Description of the Related Art Elastomeric tubular moldings typified by hoses and tubes are used in many fields such as daily necessities, automobiles and machines. Among them, they are particularly used for machine equipment, automobiles and the like. The tubular molded body is required to have chemical resistance at high temperatures.

By the way, a tubular molded body made of a thermoplastic elastomer is excellent in heat resistance and is easy to mold, so that its demand is expanding. As such a thermoplastic elastomer, for example, Japanese Examined Patent Publication (Kokoku) No. 62-34264 discloses that an oily rubber suitable for a fuel hose or the like, which is obtained by crosslinking a high molecular weight composition containing alkoxyalkyl acrylate, acrylonitrile and polyester as constituent components. Compositions have been proposed. Further, a resin composition in which a plasticizer is added to a nylon resin, which has been proposed as a known technique, is flexible and has excellent chemical resistance. However, the former oily rubber composition,
The chemical resistance at high temperature is not sufficient, and a crosslinking step is required, which is not preferable in terms of process. Further, the latter resin composition to which a plasticizer is added has a problem that the plasticizer is extracted and cured when used in oil or in a chemical.

On the other hand, a cover boot having a bellows shape, which is formed by molding the same composition as the tubular molded body, is used for the purpose of protecting a driving part such as a suspension, a steering wheel, a driving system, etc. of an automobile or a motorcycle. It is used. For example, constant velocity joint boots, rack and pinion boots, strut suspension boots, and the like. Since mechanical oil such as grease is often used in mechanical parts such as a drive unit in which such a cover boot is used, the hydraulic oil adheres to the inner surface thereof. Therefore, the material of the cover boot is also required to have the chemical resistance at the above-mentioned high temperature.

Therefore, rubber such as chloroprene, which has excellent chemical resistance, has been used as a material for the cover boot. However, since such a rubber is inferior in durability, particularly mechanical strength at high temperature, the above-mentioned thermoplastic elastomer has been used instead of the rubber. Above all, polyester-based elastomers are applied to portions where heat resistance is strongly required. An example of using this thermoplastic elastomer for a cover boot is, for example, JP-A-64-87973. This cover boot has a two-layer structure, a polyester elastomer as a base layer, and a coating layer made of a polyurethane elastomer formed on the surface thereof. In this configuration, the coating layer prevents the hydraulic oil from coming into contact with the base layer, imparts abrasion resistance, and reinforces this portion. However, the above publication does not improve the chemical resistance of the polyester elastomer itself, particularly the chemical resistance at high temperature.

[0006]

As described above, the conventional tubular molded article has a poor chemical resistance at high temperatures, and is insufficient for use in the above-mentioned mechanical equipment and automobiles. was there. Furthermore, in addition to these characteristics, the multi-layer tubular molded body is also required to have abrasion resistance and the like.

The present invention has been made to solve the above problems, and provides a method for producing a tubular molded article and a multilayer tubular molded article which are excellent in flexibility and chemical resistance at high temperature. With the goal.

[0008]

A method for producing a tubular molded article according to the present invention comprises an aliphatic dicarboxylic acid containing adipic acid as a main component and an aliphatic diol containing at least one of ethylene glycol and butylene glycol as a main component. Polyamide having a reduced viscosity of 1.8 to 7.0 at 20 ° C. in a 98% sulfuric acid solution of 1 g / dL is added to the polyester component consisting of 20 to 70 at a temperature of 150 to 230 ° C.
A step of dissolving at a ratio of wt% to obtain a transparent and homogeneous solution; a step of subjecting the solution to a temperature of 200 to 260 ° C. under reduced pressure to carry out a polycondensation reaction to obtain a transparent polyesteramide; The step of blending 0.1 to 5.0 parts by weight of polycarbodiimide with respect to 100 parts by weight to obtain a resin composition and molding the resin composition, thereby achieving the above object.

Further, as another embodiment, an inner layer is formed from the above resin composition, and at least one kind selected from the group consisting of polyadipate, polylactone, polycarbonate and polyol is used as a soft segment, and the soft segment is The number average molecular weight is 400 to 6000, and the content ratio of the soft segment is 40 to 80.
If the outer layer is formed from the elastomer made of thermoplastic polyurethane, which is the weight%, a multilayer tubular molded article can be manufactured.

In the present invention, a cover boot having a serpentine shape on the side surface of the tubular molded body is also included in the tubular molded body.

The present invention will be described in detail below.

First, a method for producing polyesteramide will be described.

The above polyester amide mainly comprises a polyester component composed of an aliphatic dicarboxylic acid and an aliphatic diol, and a polyamide.

The above aliphatic dicarboxylic acid contains adipic acid as a main component, but various dicarboxylic acids may be used within the range not impairing the physical properties of the obtained polyesteramide. For example, oxalic acid, malonic acid, succinic acid, glutaric acid, suberic acid, sebacic acid are preferably used.

The aliphatic diol contains at least one selected from the group consisting of ethylene glycol and butylene glycol as a main component, but the glycols and polyalkylenes shown below are used as long as the physical properties of the resulting polyesteramide are not impaired. Oxides can be used.

Examples of the glycol include propylene glycol, trimethylene glycol, 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-
1,3-diol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol and the like can be mentioned. These may be used alone or in combination of two or more. Examples of the polyalkylene oxide include polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polyhexamethylene oxide and the like. These may be used alone or in combination of two or more. The number average molecular weight of the polyalkylene oxide is preferably 100 to 20,000, more preferably 500 to 5,000.
When the number average molecular weight is less than 100, the obtained polyesteramide has insufficient flexibility, and when the number average molecular weight exceeds 20,000, the obtained polyesteramide has poor physical properties such as thermal stability. .

In addition to the above polyester component, aromatic diol and aromatic dicarboxylic acid may be contained as constituent components.

Examples of the above aromatic diols include 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-hydroxyphenyl)
Cyclohexane, 1,2-bis (4-hydroxyphenoxy) ethane, 1,4-dihydroxynaphthalene, 2,
6-dihydroxynaphthalene and the like can be mentioned.

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

Further, a polyfunctional monomer such as polyol or polycarboxylic acid may be added for the purpose of increasing the molecular weight of the polyesteramide and shortening the polymerization time.

The above-mentioned polyols include glycerin, trimethylolpropane, pentaerythrol, 1,2,
6-hexanetriol, sorbitol, 1,1,4
4-tetrakis hydroxymethyl cyclohexane, tris (2-hydroxyethyl) isocyanurate, dipentaerythritol, etc. are mentioned.

Examples of the polycarboxylic acid include hemimellitic acid, trimellitic acid, trimesic acid, pyromellitic acid, 1,1,2,2-ethanetetracarboxylic acid and the like.

These polyfunctional monomers are preferably used in an amount of 0.25 to 2.5 equivalents per 100 mol of the aliphatic dicarboxylic acid.

In the above polyester component, the molar ratio of the dicarboxylic acid and the diol at the time of charging is preferably 1.2 to 3 mol of the diol to 1 mol of the dicarboxylic acid. When the amount of the diol is less than 1.2 mol, the esterification reaction does not proceed efficiently, and when it exceeds 3 mol, it is disadvantageous in terms of cost.

The above polyamide has an amide bond in the polymer main chain and can be melted by heating. The reduced viscosity of the above polyamide is 2 in a 1% / dL 98% sulfuric acid solution.
It is set to 1.8 to 7.0 at 0 ° C. When the reduced viscosity is less than 1.8, the mechanical strength of the obtained polyesteramide is insufficient, and when it exceeds 7.0, it becomes difficult to produce the polyesteramide. As a preferred polyamide, toluene / isooctane = 1/1 (weight ratio)
The degree of swelling with respect to the mixed solvent of is a weight change rate of 6.0% or less.

Examples of the above polyamide include aliphatic nylon such as 4-nylon, 6-nylon, 6,6-nylon, 11-nylon and 12-nylon; isophthalic acid, terephthalic acid, metaxylylenediamine, 2,2 −
Bis (paraaminocyclohexyl) propane, 4,4 '
-Polycondensation of aromatic, alicyclic, or side chain-substituted aliphatic monomers such as diaminodicyclohexylmethane, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine Examples include polyamides.

To produce the above polyester amide,
By dissolving the polyamide in the polyester component to form a transparent and homogeneous solution, and subjecting this solution to a polycondensation reaction.

The dissolution of the polyamide and polyester components requires a transparent and uniform solution because the reaction does not proceed efficiently when the solution is in a non-uniform state. Therefore, the melting is performed at a temperature of 150 to 230 ° C. If the temperature is lower than 150 ° C, the dissolution becomes difficult, and if the temperature is higher than 230 ° C, decomposition reaction may occur, which is not preferable. Further, the charging ratio of the polyamide is 20 to 70% by weight in the charging components (that is, the total of the polyester component and the polyamide). When the above-mentioned charging ratio is less than 20% by weight, the mechanical strength of the obtained polyesteramide is insufficient, and when the above-mentioned charging amount exceeds 70% by weight, rubber properties and flexibility of the obtained polyesteramide are obtained. Run out.

The polycondensation reaction of the above solution is conducted under reduced pressure for 200
Perform at a reaction temperature of ~ 260 ° C. The reaction temperature is 200 ° C
When it is less than the above range, the reaction rate is low, and when the viscosity is high, stirring becomes difficult, and when the above reaction temperature exceeds 260 ° C., a decomposition reaction occurs, which is not preferable. The degree of reduced pressure in the reaction is preferably 1 mmHg.

In the above polycondensation reaction, a catalyst generally used for producing polyester may be used. As the catalyst, lithium, sodium, potassium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium, manganese, and other metals, Examples thereof include organic metal compounds, organic acid salts, metal alkoxides and metal oxides.

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. The intrinsic viscosity of the obtained polyesteramide is preferably 0.5 or more at 30 ° C. in o-chlorophenol. When it is less than 0.5, the mechanical strength of the obtained polyesteramide may be insufficient.

The polyesteramide obtained by the above polycondensation reaction is then blended with polycarbodiimide to obtain a resin composition.

The above polycarbodiimide is a polycarbodiimide having an average of 2 or more carbodiimides per molecule, and may be aliphatic, alicyclic or aromatic. Examples of the polycarbodiimide include poly (tolylcarbodiimide), poly (4,4′-diphenylmethanecarbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (1,3,5-triisopropyl). Phenylene-2,4
-Carbodiimide) and the like. Two or more of these polycarbodiimides may be used in combination.

The polycarbodiimide is added in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the polyesteramide. When the content of polycarbodiimide is less than 0.1 parts by weight, the strength of the obtained resin composition is lowered, and when it exceeds 5.0 parts by weight, the physical properties of the obtained resin composition are adversely affected. , Especially lack of growth.

In the above formulation, the hindered phenol-based antioxidants and sulfur-based antioxidants shown below may be used.

Examples of the hindered phenolic antioxidant include 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy] -1,1. -Dimethylethyl] 2,4,8,10
-Tetraoxaspiro [5,5] undecane, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate],
1,6-hexanediol-bis [3- (3,5-dibutyl-4-hydroxyphenyl) propionate], tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane, Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide) , 3,5-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,
3,5-Trimethyl-2,4,6-tris- (3,5-
Di-t-butyl-4-hydroxybenzyl) benzene,
Bis (3,5-t-butyl-4-hydroxybenzylphosphonate ethyl) calcium, tris- (3,5-di-
t-Butyl-4-hydroxybenzyl) -isocyanurate, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 2,2-bis [4- (2- ( 3,5-di-t-butyl-4-hydroxyhydrocinnamoyloxy)) ethoxyphenyl] propane, 2,6-di-t-butyl-4-methylphenol and the like.

Examples of the sulfur-based antioxidant include dilaryl-3,3'-thiodipropionate and dimyristyl-
3,3'-thiodipropionate, distearyl-3,
3'-thiodipropionate, pentaerythyryl tetrakis (3-lauryl thiopropionate), ditridecyl-3,3'-thiodipropionate, dioctadecis disulfide, etc. are mentioned.

The above hindered phenolic antioxidant is 0.05 per 100 parts by weight of polyesteramide.
It is preferable to add it in a ratio of ˜1.00 parts by weight. When the content is less than 0.05 parts by weight, the stabilizing effect at the time of compounding cannot be obtained, and when the content is more than 1.00 part by weight, there is a stabilizing effect but the effect. However, there is a concern that the physical properties of the resulting resin composition such as mechanical strength may deteriorate.

The sulfur antioxidant is preferably added in an amount of 0.05 to 1.6 parts by weight with respect to 100 parts by weight of the polyesteramide. When the content is less than 0.05 parts by weight, the stabilizing effect at the time of blending cannot be obtained, and when the content is more than 1.6 parts by weight, there is a stabilizing effect but the effect. There is concern about deterioration of physical properties such as mechanical strength, rather than physical properties.

The weight sum of the hindered phenol antioxidant and the sulfur antioxidant is preferably 2 parts by weight or less with respect to 100 parts by weight of the polyesteramide. When the above-mentioned weight sum exceeds 2 parts by weight, there is a stabilizing effect at the time of blending, but it is not effective, and there is a concern that physical properties such as mechanical strength may deteriorate.

The above blending is carried out by melt-kneading with an extruder, a kneader, a Banbury mixer or the like. The melt-kneading temperature is preferably the lowest temperature at which mixing is possible in order to prevent decomposition of the resin.

The obtained resin composition is then molded to obtain a tubular molded body. A cover boot, which is a tubular molded body having a partially serpentine shape, can also be obtained by molding this resin composition. Examples of the molding method include extrusion molding, injection molding, blow molding and the like, but extrusion molding using an extrusion blow molding machine is particularly preferable.

For the extrusion, single-screw and twin-screw extruders are used. 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. Further, in order to prevent decomposition during molding, it is desirable that the resin composition is sufficiently dried before being subjected to molding. The molding temperature is preferably 160 to 230 ° C. on the hopper side of the barrel, 170 to 255 ° C. on the intermediate portion and the tip portion, and the die temperature is preferably about 160 to 240 ° C., although it depends on the resin composition.

When injection molding is carried out, in order to prevent decomposition reaction during molding, the molding temperature is set so that it does not become too high and the residence time in the cylinder becomes short. The molding temperature depends on the composition of the resin, but is 160 to 230 ° C. on the hopper side of the cylinder, and is 17 at the middle part and the nozzle part.
The temperature is preferably 0 to 255 ° C., and the mold temperature is 10 to 7
The temperature is preferably 0 ° C.

When blow molding is carried out, it is in accordance with extrusion molding and injection molding.

FIG. 1 shows a side view of the cover boot obtained according to the present invention. Although the cover boot 1 has a bellows portion on its side surface portion 2, the side surface portion 2 may be entirely formed with a bellows portion.

Further, in the case of the present invention, it is also possible to produce a multi-layer tubular molding using the above resin composition as the inner layer.
In this case, an elastomer made of thermoplastic polyurethane is used for the outer layer.

The above-mentioned thermoplastic polyurethane has at least one selected from the group consisting of polyadipate, polylactone, polycarbonate and polyol as the soft segment. The hard segment is a polymer chain composed of diisocyanate and short chain glycol. The characteristics of this thermoplastic polyurethane include good flex resistance, abrasion resistance, and flexibility.

To introduce a hard segment into the molecule of the thermoplastic polyurethane, for example, an isocyanate such as 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate or isophorone diisocyanate, ethylene glycol, 1,4-butanediol,
A short chain glycol such as bisphenol A may be used.

The number average molecular weight of the soft segment is
It is 400 to 6000, preferably 800 to 3000. When the number average molecular weight is less than 400, the impact resilience and flexibility of the thermoplastic polyurethane elastomer are insufficient, and when the number average molecular weight is more than 6000, the mechanical strength is insufficient.

The content ratio of the soft segment is 40 to 80% by weight in the thermoplastic polyurethane. When the content is less than 40% by weight, the impact resilience and flexibility of the thermoplastic polyurethane are insufficient, and when the content is more than 80% by weight, the mechanical strength is insufficient.

The above-mentioned multi-layered tubular molded body can be molded by a known method. For example, a method of molding by simultaneously extruding two layers, an inner layer and an outer layer, using two extruders, the inner layer is first formed. A method of extruding and then extruding the outer layer can be mentioned. Moreover, a single-screw and a twin-screw extruder are 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 20-25.
A degree is preferable. Further, in order to prevent decomposition during molding, it is desirable that the resin composition is sufficiently dried before being subjected to molding. The molding temperature at the time of extruding the inner layer made of polyesteramide depends on the resin composition, but is 170 to 240 ° C. on the hopper side of the barrel, and 180 to 2 on the intermediate part and the tip part.
The temperature is preferably 65 ° C., and the die temperature is 170 to 2
About 50 ° C is preferable. The molding temperature at the time of extruding the outer layer made of the thermoplastic polyurethane elastomer depends on the resin composition, but is 150 to 17 on the hopper side of the barrel.
The temperature is preferably 0 ° C., 165 to 195 ° C. in the middle part and the tip part, and the die temperature is preferably about 170 to 210 ° C.

[0053]

EXAMPLES The present invention will be described below based on examples.

(Measurement Method) (i) Polyesteramide [Surface Hardness (Shore D Hardness)] Shore D hardness was measured with a D type durometer according to ASTM D2240.

(Ii) Thermoplastic polyurethane [Surface hardness (Shore A hardness)] Shore A hardness was measured with an A type durometer according to ASTM D2240.

(Iii) Tubular molded article [Oil resistance test] The tubular molded article (hose) was cut into a length of 20 cm, JIS No. 3 oil was filled in the hose, and both sides were sealed with silicone stoppers. It was left still in a gear oven at ℃. After 60 days, it was cooled to room temperature, the oil was extracted, and then the surface state (the state of cracking) when bent at 90 degrees was visually observed.

The cover boots are JIS at 130 ° C. for 60 days
It was dipped in No. 3 oil and then horizontally stretched so that the bellows portion became a flat surface, and the occurrence of cracks was observed using a 10 × magnifying glass.

[Abrasion Resistance Test] (Multilayer tubular molded body only) The obtained hose was cut into a width of 1 cm and a length of 5 cm to prepare a test piece. This test piece is fixed on a test stand, and CS-1
A wear test was performed using 7 wear wheels (load 1 kg) and H-22 wear wheels to measure the weight of the resin scraped off.
The rotation speed of the wear wheel was 60 times / minute, and the test was performed 1000 times.

In the following Examples 1 to 6 and Comparative Examples 1 to 3, single-layer tubular molded products and cover boots were manufactured.

Example 1 Production of Polyesteramide 1460 g (10 mol) of adipic acid, 1490 g (24 mol) of ethylene glycol, and 6-nylon (manufactured by Toyobo Co., Ltd., T842, 1 g / dL in a 98% sulfuric acid solution, Reduced viscosity at 20 ° C. 2.2) 1500 g,
5 g of germanium dioxide as a catalyst and 1,3,5-trimethyl-2,4,6-tris (3,5
4 g of -di-t-butyl-4-hydroxybenzyl) benzene and 4 g of tris (2,4-di-t-butylphenyl) phosphite were added to the reactor, and the reaction system was heated under nitrogen to 200
The esterification reaction was carried out by keeping the temperature at 2 ° C for 2 hours. Then, the temperature of this reaction system was raised to 240 ° C. in 20 minutes, and then 1 m
The polycondensation reaction was carried out for 50 minutes under a reduced pressure below mHg. As a result, a colorless and transparent polyesteramide was obtained.

The polyesteramide thus obtained had an intrinsic viscosity [η] of 0.95 and a Shore D hardness of 41. The tensile breaking strength was 250 kgf / cm ² and the tensile breaking elongation was 1300%.

The intrinsic viscosity [η] was measured at 30 ° C. in an o-chlorophenol solvent using an Ubbelohde viscous tube.
It was measured at. In addition, the tensile breaking strength and tensile breaking elongation were measured by injection molding (injection pressure 1500 kgf / c
m ² , mould temperature 70 ° C., cylinder temperature 200 ° C.), No. 3 dumbbell was prepared, and tensile breaking strength and tensile breaking elongation were measured according to JIS K-6301 at room temperature (23
(° C).

Preparation of Resin Composition Poly (1,3,5-triisopropylphenylene-2,4-carbodiimide) as polycarbodiimide was added to 100 parts by weight of the polyesteramide obtained above.
(Sumitomo Bayer Urethane Co., Ltd., Starbucks P-
100) 2.0 parts by weight, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy] -1 as a hindered phenolic antioxidant , 1-Dimethylethyl] 2,4,8,10
0.2 parts by weight of tetraoxaspiro [5,5] undecane and 0.1% of pentaerystyryl tetrakis (3-laurylthiopropionate) as a sulfur-based antioxidant.
Using a Brabender Plastograph extruder, 32 parts by weight was extruded and compounded at 210 ° C. to obtain a resin composition.

Molding of tubular molded body The resin composition obtained above was extruded by a uniaxial extruder with a hose mold having an inner diameter of 10 mm and an outer diameter of 14 mm to mold a hose. Molding temperature is 225 ° C. for the mold, 205 to 210 ° C. on the hopper side for the barrel part, the middle part and the tip part 22
It was set to 0 to 225 ° C.

The results of the oil resistance test on the obtained tubular molded product are shown in Table 1.

Molding of cover boots The resin composition obtained above was molded into a cover boot as shown in FIG. 1 using a blow molding machine. The molding temperature is
Mold temperature is 225 to 230 ° C, barrel part is 205 to 210 ° C on the hopper side, and 220 to 22 at the middle part and the tip part.
It was set to 5 ° C.

The obtained cover boot is indicated by A in FIG.
Has an outer diameter of 93 mm, B has an outer diameter of 30 mm, the bellows has a maximum peak of 105 mm, a minimum peak of 70 mm, a maximum valley of 72 mm, a minimum valley of 50 mm, and an average wall thickness of 1.3 mm.
Met. The results of the oil resistance test are shown in Table 1.

Example 2 Production of Polyesteramide A polyesteramide was produced in the same manner as in Example 1 except that 2160 g (24 mol) of butylene glycol was used instead of ethylene glycol in Example 1. The Shore D hardness of this polyesteramide is 4
0, the tensile strength at break was 270 kgf / cm ² , and the tensile elongation at break was 1300%.

Preparation of Resin Composition Example 1 was prepared using the polyesteramide obtained above.
A resin composition was prepared in the same manner as in.

Subsequent steps and in the same manner as in Example 1 and, a tubular molded body and a cover boot were manufactured, and the results of the oil resistance test are shown in Table 1.

Example 3 Production of Polyesteramide A polyesteramide was produced in the same manner as in Example 1 except that 2000 g of 6-nylon was used in Example 1. The Shore D hardness of this polyesteramide is 4
It was 3.

In the subsequent steps 1 to 4, tubular molded articles and cover boots were manufactured in the same manner as in Examples 1 and the results of the oil resistance test are shown in Table 1.

Example 4 Production of Polyesteramide Polyesteramide was produced in the same manner as in Example 1 except that 500 g of 6-nylon was used in Example 1. The Shore D hardness of this polyesteramide is 34.
Met.

Subsequent steps (1) to (3) were carried out in the same manner as in Examples 1 to 1 to produce tubular molded articles and cover boots, and the results of the oil resistance test are shown in Table 1.

Example 5 Production of Polyesteramide A polyesteramide was produced in the same manner as in Example 1 except that 2000 g of 6-nylon was used in Example 2. The Shore D hardness of this polyesteramide is 5
It was 1.

In the subsequent steps 1 to 4, tubular molded articles and cover boots were manufactured in the same manner as in Examples 1 to 1, and the results of the oil resistance test are shown in Table 1.

(Example 6) Production of Polyesteramide Except that 1742 g of methyl adipate was used instead of adipic acid in Example 1, 1500 g of 6-nylon was used, and 2.2 g of calcium acetate was newly used.
A polyesteramide was produced in the same manner as in Example 1. The Shore D hardness of this polyesteramide was 47.

In the subsequent steps 1 to 5, tubular molded articles and cover boots were manufactured in the same manner as in Examples 1 to 1, and the results of the oil resistance test are shown in Table 1.

Comparative Example 1 Production of Polyesteramide A polyesteramide was produced in the same manner as in Example 1 except that 6-nylon was not added. The Shore D hardness of this polyesteramide is 23.
Met.

In the subsequent steps 1 to 4, tubular molded articles and cover boots were manufactured in the same manner as in Examples 1 and the results of the oil resistance test are shown in Table 1.

Comparative Example 2 Production of Polyesteramide A polyesteramide was produced in the same manner as in Example 1 except that 6-nylon was changed to 75 g in Example 1. The Shore D hardness of this polyesteramide is 25.
Met.

In the subsequent steps 1 to 4, tubular molded articles and cover boots were produced in the same manner as in Examples 1 to 1, and the results of the oil resistance test are shown in Table 1.

(Comparative Example 3) Production of polyesteramide A polyesteramide was produced in the same manner as in Example 1 except that 6-nylon was 4000 g in Example 1. The Shore D hardness of this polyesteramide is 5
It was 9. This polyesteramide lacked flexibility.

In the subsequent steps 1 to 5, tubular molded articles and cover boots were produced in the same manner as in Examples 1 to 1, and the results of the oil resistance test are shown in Table 1.

[0085]

[Table 1]

Examples 7 to 12 and Comparative Example 4 shown below
In and 5, a multilayer tubular molded body was produced.

Example 7 In this example, the resin composition obtained in Example 1 was used as the inner layer, and the thermoplastic polyurethane obtained in the following steps was used as the outer layer.

Production of Thermoplastic Polyurethane First, 4,4-diphenylmethane diisocyanate (M
DI) 550 g (2.2 mol), polytetramethylene oxide glycol (number average molecular weight 1500) 150
0 g (1 mol) and 1,4-butylene glycol 9
A glass container was charged with 0.12 g (1 mol). Then, the mixture was reacted at 70 ° C. for 3 hours under a nitrogen stream, and then 12
By reacting at 0 ° C. for 10 hours, a white elastic thermoplastic polyurethane was obtained. This thermoplastic polyurethane has a Shore A hardness of 83 and a tensile breaking strength of 400 k.
It was gf / cm ² .

Molding of Multi-Layer Tubular Molded Body First, the inner layer was molded by extruding the above resin composition with a hose mold having an inner diameter of 20 mm and an outer diameter of 22 mm by a uniaxial extruder. The molding temperature was 210 ° C. for the mold and 205 to 210 ° C. for the cylinder part.

Subsequently, the inner layer was passed through a hose mold having an inner diameter of 24 mm and an outer diameter of 26 mm, and the outer layer (thermoplastic polyurethane) obtained above was extruded. Molding temperature is 17
The temperature was 0 to 175 ° C, and the cylinder portion was 165 to 170 ° C. In this way, a multi-layer tubular molded product was obtained in which the inner layer was the resin composition of Example 1 and the outer layer was the above-mentioned thermoplastic polyurethane. When an oil resistance test was conducted on this multi-layer tubular molded product, it was found that there was no cracking and rubber elasticity was retained. The results are shown in Table 2 together with the abrasion resistance test.

Example 8 In this example, the resin composition obtained in Example 1 was used as the inner layer, and the thermoplastic polyurethane obtained in the following step was used as the outer layer.

Production of Thermoplastic Polyurethane A thermoplastic polyurethane was obtained in the same manner as in Example 7 except that polycaprolactone (hydroxyl group at terminal, number average molecular weight 1500) was used in place of polytetramethylene oxide glycol in Example 7. It was The Shore A hardness of this thermoplastic polyurethane is 82, and the tensile breaking strength is 380 k.
It was gf / cm ² .

Molding of multi-layer tubular molding A multi-layer tubular molding was produced in the same manner as in Example 7, in which the inner layer was the resin composition of Example 1 and the outer layer was the above-mentioned thermoplastic polyurethane. An oil resistance test and an abrasion resistance test were performed on this multilayer tubular molded product in the same manner as in Example 7. The results are shown in Table 2.

(Example 9) In this example, the resin composition obtained in Example 1 was used as the inner layer, and the thermoplastic polyurethane obtained in the following steps was used as the outer layer.

Production of thermoplastic polyurethane Polybutylene adipate (having a hydroxyl group at the end, instead of polytetramethylene oxide glycol in Example 7)
A thermoplastic polyurethane was obtained in the same manner as in Example 7 except that the number average molecular weight was 1500). This thermoplastic polyurethane has a Shore A hardness of 83 and a tensile breaking strength of 39.
It was 0 kgf / cm ² .

Molding of multi-layer tubular molding A multi-layer tubular molding was produced in the same manner as in Example 7, in which the inner layer was the resin composition of Example 1 and the outer layer was the above-mentioned thermoplastic polyurethane. An oil resistance test and an abrasion resistance test were performed on this multilayer tubular molded product in the same manner as in Example 7. The results are shown in Table 2.

Example 10 In this example, a multi-layer tubular molding was produced using the resin composition obtained in Example 2 as the inner layer and the thermoplastic polyurethane obtained in Example 7 as the outer layer. . An oil resistance test and an abrasion resistance test were performed on this multilayer tubular molded product in the same manner as in Example 7. The results are shown in Table 2.

Example 11 In this example, a multi-layer tubular molded article was produced using the resin composition obtained in Example 2 as the inner layer and the thermoplastic polyurethane obtained in Example 8 as the outer layer. . An oil resistance test and an abrasion resistance test were performed on this multilayer tubular molded product in the same manner as in Example 7. The results are shown in Table 2.

(Example 12) In this example, a multi-layer tubular molding was produced using the resin composition obtained in Example 2 as the inner layer and the thermoplastic polyurethane obtained in Example 9 as the outer layer. . An oil resistance test and an abrasion resistance test were performed on this multilayer tubular molded product in the same manner as in Example 7. The results are shown in Table 2.

Comparative Example 4 In this comparative example, the resin composition obtained in Example 1 was used as the inner layer, the outer layer was not used, and a mold having an inner diameter of 20 mm and an outer diameter of 24 mm was used to form a tubular molded body. Molded. The molding temperature was 210 ° C. for the mold and 205 to 210 ° C. for the cylinder part. With respect to this tubular molded body, an oil resistance test and an abrasion resistance test were performed in the same manner as in Example 7. The results are shown in Table 2.

(Comparative Example 5) In this comparative example, a tubular molded body was molded in the same manner as in Comparative Example 4 except that the resin composition obtained in Example 2 was used as the inner layer and the outer layer was not used. With respect to this tubular molded body, an oil resistance test and an abrasion resistance test were performed in the same manner as in Example 7. The results are shown in Table 2.

[0102]

[Table 2]

[0103]

As is clear from the above description, in the present invention, a polyesteramide having excellent mechanical strength and transparency can be easily obtained. By molding a resin composition in which polycarbodiimide is blended with such a polyesteramide in a specific ratio, it is possible to easily obtain a tubular molded article having excellent flexibility and chemical resistance at high temperatures. When the resin composition is used as the inner layer and the thermoplastic polyurethane is used as the outer layer, it is possible to obtain a multilayer tubular molded article having excellent wear resistance, flexibility, and chemical resistance at high temperatures.

The tubular molded article and the multilayer tubular molded article obtained by the present invention are suitably used for automobile parts, electric / electronic parts, industrial parts, sports goods, medical goods and the like.

[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 side

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI technical display location C08L 75/04 NFX 8620-4J (72) Inventor Hiroki Kadomachi 1-chome Minami Kasugaoka, Ibaraki City, Osaka Prefecture No. 11-3 (72) Inventor Daishiro Kishimoto 2-24-23 Mishimaoka, Ibaraki-shi, Osaka Sunhits Mishimaoka 306

Claims (2)

[Claims] 1. A polyester component comprising an aliphatic dicarboxylic acid containing adipic acid as a main component and an aliphatic diol containing at least one of ethylene glycol and butylene glycol as a main component, and 1 g / dL of a 98% sulfuric acid solution. Medium, a polyamide having a reduced viscosity at 20 ° C. of 1.8 to 7.0 at a temperature of 150 to 230 ° C. for 20 to 20 ° C.
A step of dissolving at a ratio of 70% by weight to form a transparent and homogeneous solution; a step of subjecting the solution to a temperature of 200 to 260 ° C. under reduced pressure to carry out a polycondensation reaction to obtain a transparent polyesteramide; A method for producing a tubular molded body, comprising the step of blending 0.1 to 5.0 parts by weight of polycarbodiimide with 100 parts by weight of an amide to obtain a resin composition and molding the resin composition. 2. An inner layer is formed from the resin composition according to claim 1, and at least one kind selected from the group consisting of polyadipate, polylactone, polycarbonate and polyol is used as a soft segment, and the number of the soft segment is A method for producing a multi-layer tubular molded article, which comprises forming an outer layer from an elastomer made of thermoplastic polyurethane and having an average molecular weight of 400 to 6000 and a soft segment content of 40 to 80% by weight. .