JP2000254925A - Mandrel and production of high pressure rubber hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mandrel comprising a flexible polyester elastomer excellent in heat resistance, water resistance, heat-ageing resistance, chemical resistance and heat cycle properties and a method for producing a rubber hose using the mandrel. SOLUTION: A mandrel is formed of a thermoplastic polyester elastomer with a crystalline m.p. y( deg.C) satisfying formula y>=200+0.5x [wherein x is a numerial value being the substantial hard segment content (wt.%) of the thermoplastic polyester elastomer], a Vicat softening temp. z( deg.C) satisfying formula z>=50+1.5x and a tensile elongation of 100% or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mandrel for producing a rubber hose, in which the flexibility, durability and heat aging resistance of the mandrel are remarkably improved, and a method for producing a rubber hose using this mandrel.

[0002]

2. Description of the Related Art A high-pressure rubber hose is a flexible hose having high pressure resistance used for a hydraulic system for controlling a robot, a civil engineering / construction machine, an automobile, and the like.
An inner rubber layer that is in direct contact with the liquid to be transported and has durability against the liquid, and an expansion of the inner rubber layer provided on the outside thereof and caused by a pressure applied to the liquid to be transported,
It has a structure with a layer having a reinforcing fiber material to prevent deformation and destruction, and an outer layer to protect them, and further provided with a wire material layer such as a coil-shaped reinforcing wire and other rubber layers as necessary. It is a hose.

Conventionally, rubber hoses such as the above-mentioned high-pressure rubber hoses are formed by covering a raw material of a layer constituting the rubber hose with a mandrel as a core material and removing the mandrel from the hose after vulcanization. In this case, the mandrel is required to have good flexibility in handling such as winding work around a drum in the manufacture of a hose because it is a long product, and heat resistance for vulcanizing a rubber hose. Further, since the mandrel is used repeatedly, it is particularly required that the dimensional change and the heat aging property (heat cycle property) be good.

Conventionally, thermoplastic resins such as polyester elastomers and polyamide elastomers have been used for such flexible mandrels. However, these thermoplastic resins satisfy short-term heat resistance and flexibility, but when used repeatedly at high temperatures, dimensional changes due to the heat cycle may occur significantly, and in the worst case, In addition, there has been a problem that heat deterioration or hydrolysis occurs and the ink cannot be used.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a mandrel having the same flexibility as conventional high-pressure rubber hoses, and having excellent heat resistance, water resistance, heat aging resistance, chemical resistance and heat cycle properties, and the use of this mandrel. It is intended to provide a method for producing a rubber hose.

[0006]

Means for Solving the Problems The present inventors have found that the above problems can be solved by using a specific hard segment and a plurality of specific soft segments in a polyester elastomer, and have accomplished the present invention. It has arrived.

The mandrel of the present invention has a crystal melting point y (° C.)
Satisfies the formula (1), the Vicat softening temperature z (° C.) satisfies the formula (2), and the tensile elongation is 100% or more. It is assumed that. (1) y ≧ 200 + 0.5x (2) z ≧ 50 + 1.5x Here, x is a numerical value representing the substantial hard segment content in the thermoplastic polyester elastomer by weight%.

[0008] In addition, y is a heating rate of 20 ° C. /
Is the crystal melting point (° C.) measured in minutes, and z is ASTM
Vicat softening temperature (° C) measured based on D1525
It is. The tensile elongation (%) is a value measured based on JIS K6251.

However, the mandrel formed of the polyester elastomer is flexible and has the same properties as conventional rubber hoses, and has excellent heat resistance, water resistance, heat aging resistance, chemical resistance, and heat cycle properties.

% By weight of the content of the hard segment
The relationship between the indicated numerical value x and the crystal melting point y (° C.) is preferably
More preferably, y ≧ 200 + 0.55x, and particularly preferably, y ≧ 200 + 0.6x. The relationship between x and the Vicat softening temperature z (° C.) is more preferably z ≧ 50 + 1.7x, and particularly preferably z ≧ 70 +.
1.7x.

When y and z do not satisfy the above formulas (1) and (2), the heat resistance is not sufficient, and the difference in characteristics from the conventional resin mandrel is not clear.

The upper limits of y and z are the crystal melting point and the Vicat softening temperature of the high polymer formed only of the ester unit (1) constituting the hard segment. The elongation of the polyester elastomer is 100% or more. Preferably, y is 300 or less and z is preferably 250 or less.

The Vicat softening temperature is measured by melt-molding a sample to prepare a measurement sample having a predetermined shape, depending on the shape of the sample.

In the above-mentioned mandrel, it is preferable that the range of x in the thermoplastic polyester elastomer constituting the mandrel is 30 to 95.

The substantial hard segment of the thermoplastic polyester elastomer used in the mandrel of the present invention is preferably composed of a repeating unit represented by the following formula (5).

[0016]

Embedded image In the above mandrel, the constituent units other than the substantial hard segments of the thermoplastic polyester elastomer constituting the mandrel are (Chem. 6) to (Chem. 8), and the reduced viscosity is 0.5 to 4.0. It is preferably 0.

[0017]

Embedded image

Embedded image

Embedded image In the formulas (Chem. 5) to (Chem. 8), R is an aromatic group having 6 to 18 carbon atoms, G is a polyoxyalkylene group having a molecular weight of 400 to 6000, D is a residue of hydrogenated dimer diol and / or a derivative thereof. , R 'represents an alkylene group having 1 to 25 carbon atoms.
A, b, and c each represent the weight percent of each repeating unit in the whole polymer, d represents the mole percent in the whole polymer, a = 30 to 95 wt%, d = 0 to 20 mol%, b /
b + c is 0.01 to 0.99. Note that a is the value of x in Equation (1) for the preferred example of the structure of the hard segment.

Adv. Chem. . Ser. , 176,
129 (1979). According to this publication, it is described that in a polyester elastomer composed of only polycyclohexane dimethylene terephthalate and polytetramethylene glycol, when polycyclohexane dimethylene terephthalate is contained in an amount of 50% by weight or more, phase separation occurs, and no elastic performance as an elastomer is exhibited. However, surprisingly, in the present invention, by changing the soft segment from polyalkylene glycol alone to a combined system of polyalkylene glycol and hydrogenated dimer diol and / or a derivative thereof, the amount of hard segment can be increased to 50% by weight or more. It has been found by the present inventor and others that sufficient elasticity is exhibited. The reason for this is not clear, but hydrogenated dimer diol having a cyclohexane skeleton and / or
Alternatively, since the derivative functions as a compatibilizing agent for polycyclohexane dimethylene terephthalate and polyalkylene glycol, it is presumed that the compatibility between both is improved.

The method for producing a rubber hose of the present invention, in particular, a high-pressure rubber hose, is a method for coating and molding at least a raw material for forming an inner rubber layer and a raw material for forming a reinforcing fiber material layer on a mandrel surface, followed by heat vulcanization. A mandrel according to any one of claims 1 to 4 is used as a mandrel.

It is preferable to provide an outer layer which is a rubber layer for preventing corrosion and wear of the reinforcing fiber material layer, a wire layer such as a coil-shaped reinforcing wire, and other rubber layers, if necessary. It is an aspect.

Heat resistance, water resistance, heat aging resistance, chemical resistance,
As a result of using a mandrel with excellent heat cycle properties,
It is possible to manufacture rubber hoses at low cost.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In the thermoplastic polyester elastomer constituting the mandrel of the present invention, the above-mentioned y, z
The acid component constituting the repeating unit represented by the above general formulas (Chemical Formula 5) to (Chemical Formula 8) in order to satisfy the condition of (A) is mainly composed of an aromatic dicarboxylic acid, and specifically, terephthalic acid, It is preferable to use one or a combination of two or more selected from naphthalenedicarboxylic acid, diphenyldicarboxylic acid, isophthalic acid, and 5-sodium sulfoisophthalic acid, and it is particularly preferable to use one or both of terephthalic acid and naphthalenedicarboxylic acid. .

The aromatic dicarboxylic acid is preferably at least 70 mol%, more preferably at least 80 mol% of the total acid components. As other acid components, alicyclic dicarboxylic acids and aliphatic dicarboxylic acids can be used. Specific examples of the alicyclic dicarboxylic acids include cyclohexanedicarboxylic acid,
And tetrahydrophthalic anhydride. Further, specific examples of the aliphatic dicarboxylic acid include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecane diacid, dimer acid, hydrogenated dimer acid and the like. These alicyclic dicarboxylic acids and aliphatic dicarboxylic acids are used within a range that does not significantly lower the melting point of the thermoplastic polyester elastomer resin, and the amount thereof is preferably less than 30 mol%, more preferably 20 mol% of the total acid components.
Is less than.

The glycol component constituting the repeating unit represented by the general formula (Formula 5) (hereinafter referred to as ester unit (1)) is 1,4-cyclohexanedimethanol. 1,4-cyclohexanedimethanol has two types of isomers, a cis form and a trans form, and it is preferable that the ratio of the trans form is large.

The total content of the ester unit (1) in all the polymers is a (% by weight), and a is 30 to 95% by weight, preferably 40 to 90% by weight, particularly 50 to 85% by weight. It is desirable. If it exceeds 95% by weight, the flexibility is reduced and the elastic performance of the mandrel cannot be sufficiently obtained. On the other hand, if it is less than 30% by weight, the melting point decreases and the heat resistance of the mandrel becomes insufficient, which is not preferable.

The glycol component constituting the repeating unit represented by the above general formula (Chemical formula 6) (hereinafter referred to as ester unit (2)) is not particularly limited. For example, polyoxyethylene glycol, polyoxypropylene glycol or both terminals thereof It is desirable to use a polyoxyalkylene glycol such as an ethylene oxide adduct, polyoxytetramethylene glycol, or an ethylene oxide adduct at both ends thereof. The molecular weight of the polyoxyalkylene glycol is preferably from 400 to 6000, more preferably from 800 to 3,000, and particularly preferably from 1,000 to 2,000.

If the molecular weight of the glycol component constituting the ester unit (2) is less than 400, the elasticity is insufficient, and if the weight ratio of the glycol component in the polyester elastomer resin is the same, the case where the molecular weight is 400 or more is obtained. Since the molar ratio becomes higher, as a result, the molar ratio of the hard segment decreases, the blockability decreases, and the hard segment of the elastomer is not long enough to show crystallinity, so that the melting point and the Vicat softening temperature of the polymer are increased. descend. When the molecular weight exceeds 6,000, phase separation is liable to occur, and during polymerization, the compatibility with other copolymerization components is reduced and copolymerization becomes difficult, which also impairs the elastic performance of the thermoplastic elastomer constituting the mandrel. It is not preferable because it may cause a sufficient effect.

The hydrogenated dimer diol which is a glycol component constituting the repeating unit (hereinafter referred to as an ester unit (3)) represented by the general formula (Formula 7) is, for example, an unsaturated fatty acid (having 15 to 21 carbon atoms). A compound containing a compound represented by the following general formula (5) obtained by hydrogenating dimer acid which is a dimer as a main component (50% by weight or more), or a compound represented by the following general formula (Chemical formula 9) and It is a mixture with the compound represented by the general formula (Formula 10).
However, it is not limited to this.

[0029]

Embedded image (In the above formula, R ¹ , R ² , R ³ , and R ⁴ are substantially free from unsaturated groups and are substantially linear, and among them, R ¹ ,
R ² is an alkyl group, R ³ and R ⁴ are alkylene groups,
The total number of carbon atoms of R ^{1 to} R ⁴ is 22 to 34. )

Embedded image (In the above formula, R ⁵ , R ⁶ , R ⁷ , and R ⁸ are substantially free from unsaturated groups and are substantially linear, and among them, R ⁵ ,
R ⁶ is an alkyl group, R ⁷ and R ⁸ are alkylene groups,
The total number of carbon atoms of R ⁵ to R ⁸ is 25 to 37. The hydrogenated dimer diol derivative is a diol compound substantially derived from the hydrogenated dimer diol, and specific examples thereof include an ethylene oxide and / or propylene oxide adduct of the hydrogenated dimer diol.
The addition of the oxide compound may be at both ends or only one end of the hydrogenated dimer diol. The number of moles of the oxide compound to be added is preferably equimolar to 20 times the number of moles of the hydrogenated dimer diol.

As the glycol component constituting the repeating unit (hereinafter referred to as ester unit (4)) represented by the above general formula (Chem. 8), an alkylene glycol having 1 to 25 carbon atoms can be used. For example, ethylene glycol, diethylene glycol, propylene glycol,
1,3-butanediol, 1,4-butanediol,
1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, dimethylol heptane, dimethylol pentane, tricyclodecane dimethanol, bisphenol X (X is A, S, F) And ethylene oxide addition derivatives thereof. These glycols are used in an appropriate combination depending on the balance of various properties, but an ester unit (1) composed of cyclohexanedimethanol and an aromatic carboxylic acid is used.
It is premised that the crystallinity of the glycol is not hindered. Therefore, the copolymerization amount of these glycols is 20
Desirably, it is at most mol%.

The proportion of the ester unit (2) and the ester unit (3) is not particularly limited because it is used in an appropriate combination according to various balances, but the weight sum of the ester unit (2) and the ester unit (3) is not limited. The ratio of the ester unit (2) is preferably 0.01 to 0.99, more preferably 0.05 to 0.95, and particularly preferably 0.1 to 0.9. If it is less than 0.01, the elastic performance as an elastomer will be lacking, and if it is more than 0.99, compatibility with the hard segment will be lacking, and the elastic performance as a mandrel will be lacking.

In the thermoplastic polyester elastomer constituting the mandrel of the present invention, a tri- or higher functional polycarboxylic acid or polyol component may be used in a small amount. Specifically, examples of the polycarboxylic acid include trimellitic anhydride, benzophenonetetracarboxylic acid, and pyromellitic anhydride, and examples of the polyol component include trimethylolpropane, glycerin, and pentaerythritol. It can be used in the range of mol% or less.

Next, as a method for obtaining the thermoplastic polyester elastomer used for the mandrel of the present invention, any known method can be adopted. For example, any of a melt polymerization method, a solution polymerization method, a solid phase polymerization method and the like can be appropriately used. In the case of a melt polymerization method, a transesterification method or a direct polymerization method may be used. In order to improve the viscosity of the resin,
Performing solid phase polymerization after melt polymerization is, of course, a desirable embodiment.

In the above-mentioned polymerization method, as the catalyst used for the polymerization reaction, known catalysts can be used without any particular limitation, but antimony catalysts, germanium catalysts and titanium catalysts are preferred. Particularly preferred titanium catalysts include tetraalkyl titanates such as tetrabutyl titanate and tetramethyl titanate. It is also preferable to use a metal oxalate such as potassium titanium oxalate. Examples of other catalysts include tin compounds such as dibutyltin oxide and dibutyltin dilaurate, and lead compounds such as lead acetate.

The obtained polyester elastomer includes known antioxidants such as hindered phenol, sulfur, phosphorus, and amine, hindered amine, triazole, benzophenone, benzoate, nickel, salicylic acid and the like. Light stabilizers, antistatic agents, lubricants,
Molecular weight regulators such as peroxides, compounds having reactive groups such as epoxy compounds, isocyanate compounds, carbodiimide compounds, metal deactivators, organic and inorganic nucleating agents, neutralizing agents, antacids, Bactericides, optical brighteners, inorganic fibrous substances such as glass fiber, carbon fiber, silica fiber, alumina fiber, carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, kaolin, talc, clay, Granular filling of diatomaceous earth, silicates such as wollastonite, oxides of metals such as iron oxide, titanium oxide, zinc oxide and alumina, carbonates of metals such as calcium carbonate and barium carbonate, and various other metal powders Additives such as fillers, mica, glass flakes, plate-like fillers such as various metal powders, flame retardants, flame retardant aids, and organic and inorganic pigments Rukoto can.

These additives can be compounded using a kneader such as a heating roll, an extruder or a Banbury mixer. Further, it can be added and mixed into the oligomer before the transesterification reaction or before the polycondensation reaction when producing the thermoplastic polyester elastomer resin composition.

The reduced viscosity of the thermoplastic polyester elastomer used in the present invention is preferably 0.5 to 4.0,
More preferably, it is 0.5 to 3.0. The reduced viscosity is 0.
If it is less than 5, mechanical properties are inferior, and if it exceeds 4.0, moldability is inferior.

Although the lower limit of the melting point of the thermoplastic polyester elastomer composition of the present invention is not particularly limited, it is generally preferably 150 ° C. or higher. 200 ° C. or higher is preferred for applications requiring heat resistance, but 230 ° C. or higher is particularly preferred for applications requiring heat resistance.

The mandrel of the present invention has no particular problem even if it is composed of a single layer or two or more layers.
The polyester elastomer composition described above may be used for either the inner tube or the outer tube. As a combination of resin materials used for the inner tube and the outer tube, polyolefin resin,
Any combination of a polyvinyl chloride resin, a polyamide resin, a polyester resin, a thermoplastic elastomer resin or the like and the polyester elastomer described above can be arbitrarily selected. The polyester elastomers having different hardnesses of the present invention may be used as the inner tube and the outer tube. To improve the adhesion between these inner and outer tubes, alloy materials, isocyanates,
There is no problem even if an adhesive such as a phenol resin, an epoxy resin, or a urethane is used.

In the mandrel of the present invention, the presence or absence of the reinforcing material is not particularly limited. The reinforcing agent may be formed in a blade shape or a spiral shape, and the material used may be a thread or a wire. Examples of the reinforcing yarn include yarns made of vinylon fiber, rayon fiber, polyester fiber, nylon fiber, aromatic polyamide fiber, and the like. Examples of the reinforcing wire include a hard steel wire, and more specifically, a steel wire plated with brass, zinc, or the like for rust prevention and imparting adhesiveness. It is a preferable embodiment to use an adhesive for these reinforcing materials for the purpose of improving the adhesiveness with the above-mentioned resins, and as the adhesive to be used, isocyanate-based, phenolic-based, epoxy-based, and urethane-based adhesives are used. And the like.

The method for producing a rubber hose of the present invention is carried out by a known method using the mandrel according to claims 1 to 4. The following method is exemplified as a specific manufacturing method.

The unvulcanized rubber composition as the inner rubber layer forming material kneaded with a predetermined composition is supplied to an extruder preferably having a crosshead, and the crosshead is provided with the present invention at right angles to the extrusion direction. The mandrel is supplied, and the unvulcanized rubber composition is moved around the mandrel to a predetermined thickness while moving the mandrel.
Coat evenly. The steel fiber is then wound around the unvulcanized rubber layer in two layers, preferably crossing each other, and the outer layer forming rubber material is preferably coated with a separate extruder. Thereafter, a vulcanization reaction is carried out by an appropriate heating device such as a continuous oven and a vulcanization can to produce a rubber hose.

[0043]

The present invention will be specifically described below with reference to examples. In these examples, each evaluation item was measured and evaluated according to the following method. The weight% of polycyclohexane dimethylene terephthalate, polytetramethylene glycol and the like in the obtained polymer is a value measured by proton NMR.

Reduced viscosity: 25 g of 0.05 g of polymer
1 of a mixed solvent (phenol / tetrachloroethane = 60)
/ 40 (wt / wt)) and measured at 30 ° C using an Ostwald viscometer. Crystal melting point: 20 ° C. heating rate from room temperature using DSC
/ Min. -Flexural modulus: Measured according to ASTM D790. -Tensile strength and tensile elongation: Measured according to JIS K6251. Vicat softening temperature: Measured according to ASTM D1525.

Flexibility: The force (k) required to bend a φ9 mm mandrel to a bending radius (4D) four times its diameter D
gf). -Durability: Using the mandrels obtained in Production Examples 1 and 2, a steel wire braid (2 W / B), a 200 m long hose was formed, and after vulcanization, a mandrel blow test was performed as follows, and this mandrel was used 10 times. The variation of the diameter when used continuously and repeatedly was measured, and the evaluation results were indicated as follows. Mandrel diameter fluctuation None… ○ (Diameter change ± 0.12mm or less) Available… × (Diameter change ± 0.12mm or more) ・ Heat aging resistance: Heat treatment of 200mm length mandrel by gear type aging tester at 150 ℃ for 30 days Aging test. Thereafter, the above-described flexibility test was performed, and the presence or absence of cracks and breaks was observed.

(Synthesis Example 1 of Polyester Elastomer) 460 parts by weight of dimethyl terephthalate, 460 parts by weight of cyclohexanedimethanol, 50 parts by weight of hydrogenated dimer diol (HP1000, manufactured by Toagosei Co., Ltd.), 300 parts by weight of polytetramethylene glycol (molecular weight: 1000) , GA
2 parts by weight of -80 (manufactured by Sumitomo Chemical Co., Ltd.) and 0.9 parts by weight of tetrabutyl titanate are charged into a synthesis can equipped with a stirrer, and the temperature is raised from room temperature to 260 ° C. over 2 hours. The mixture was heated for an hour to perform a transesterification reaction. Next, the inside of the can was gradually reduced in pressure and the temperature was raised, and the initial polycondensation reaction was performed at 275 ° C. and 1 torr or less over 45 minutes. Further, a polymerization reaction was carried out at 275 ° C. and 1 torr or less for 4 hours. After the completion of the polymerization reaction, the polymer was taken out in the form of pellets to obtain polymer A. The reduced viscosity of the obtained polymer A was 1.04, and the weight% of the polycyclohexane dimethylene terephthalate component, the polytetramethylene glycol component and the hydrogenated dimer diol component in the polymer was
Was 65%, 30%, and 5%, respectively.

(Synthesis Example 2 of Polyester Elastomer) 530 parts by weight of dimethyl terephthalate, 750 parts by weight of cyclohexanedimethanol, 50 parts by weight of hydrogenated dimer diol (HP1000, manufactured by Toagosei Co., Ltd.), 200 parts by weight of polytetramethylene glycol (molecular weight: 1000) , GA
2 parts by weight of -80 (manufactured by Sumitomo Chemical Co., Ltd.) and 0.9 parts by weight of tetrabutyl titanate are charged into a synthesis can equipped with a stirrer, and the temperature is raised from room temperature to 260 ° C. over 2 hours, and then at 260 ° C. for 1 hour. The mixture was heated to perform a transesterification reaction. Next, the inside of the can was gradually reduced in pressure and the temperature was raised, and the initial polycondensation reaction was performed at 275 ° C. and 1 torr or less over 45 minutes. Further, the polymerization reaction was carried out at 275 ° C. and 1 torr or less for 4 hours, and the polymer was taken out in the form of pellets to obtain polymer B. The reduced viscosity of the obtained polymer B is 1.1.
0, and the weight% of the polycyclohexane dimethylene terephthalate component, the polytetramethylene glycol component and the hydrogenated dimer diol component in the polymer is 75% each.
%, 20% and 5%.

(Synthesis Example 3 of Polyester Elastomer) 590 parts by weight of dimethylnaphthalate, 400 parts by weight of 1,4-butanediol, 350 parts by weight of polytetramethylene glycol (molecular weight 1000), 2 parts by weight of GA-80 (manufactured by Sumitomo Chemical Co., Ltd.) And 0.9 parts by weight of tetrabutyl titanate, and the temperature was raised from room temperature to 220 ° C. over 2 hours, followed by heating at 220 ° C. for 1 hour to perform a transesterification reaction. Next, the pressure inside the can was gradually reduced and the temperature was increased.
The initial polycondensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Further, the polymerization reaction was carried out at 250 ° C. and 1 torr or less for 3 hours, and the polymer was taken out in the form of a pellet to obtain Polymer C. The reduced viscosity of the obtained polymer C was 1.78, and the weight percentages of the polybutylene naphthalate component and the polytetramethylene glycol component in the polymer were 65% and 35%, respectively.

Polyester Synthesis Example 4 570 parts by weight of dimethyl terephthalate, 580 parts by weight of 1,4-butanediol, 350 parts by weight of polytetramethylene glycol (molecular weight: 1000), 2 parts by weight of GA-80 (manufactured by Sumitomo Chemical Co., Ltd.), tetrabutyl Titanate 0.9
A part by weight was charged, the temperature was raised from room temperature to 200 ° C. over 2 hours, and then the mixture was heated at 200 ° C. for 1 hour to perform a transesterification reaction. Next, the pressure inside the can was gradually reduced and the temperature was raised, and the initial polycondensation reaction was performed at 245 ° C. and 1 torr or less over 45 minutes. Further, the polymerization reaction was carried out at 245 ° C. and 1 torr or less for 3 hours, and the polymer was taken out in the form of pellets to obtain polymer D. The reduced viscosity of the obtained polymer D was 1.94, and the weight percentages of the polybutylene terephthalate component and the polytetramethylene glycol component in the polymer were 65% and 35%, respectively.

(Examples 1 and 2, Comparative Examples 1 and 2) Polymers A to 4 obtained in polyester elastomer synthesis examples 1 to 4
D 0.5 parts by weight of pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] to 100 parts by weight of each
0.3 parts by weight of pentaerythritol tetrakis- (3-laurylthiopropionate), 0.5 parts by weight of 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) benzotriazole, and bisphenol A 0.5 parts by weight and 0.3 parts by weight of triphenylphosphine were blended, taken out into pellets using an extruder, and dried with a hot air drier to a moisture content of 0.1% or less.

Using the polyester elastomer obtained above, a mandrel having a diameter of 9 mm was molded by a single screw extruder and evaluated.

X in Table 1 is a numerical value indicating the weight% of the substantial hard segment of the polyester elastomer.

[0053]

[Table 1]

According to the results shown in Table 1, the crystal melting point y and the Vicat softening temperature z are set so as to satisfy the conditions of the formulas (1) and (2), that is, the crystal melting point is higher than that of the conventional polyester elastomer having a mandrel. It is apparent that the durability and the heat aging resistance can be improved while maintaining the flexibility by increasing the temperature by about 60 ° C. and the Vicat softening temperature by about 50 ° C.

As a result, by using the mandrel of the present invention, the life of the mandrel in the production of a rubber hose is lengthened, and effects such as a reduction in production cost and a reduction in waste are obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08G 63/672 C08G 63/672 4J029 C08J 5/00 CFD C08J 5/00 CFD C08L 67/02 C08L 67/02 // B29K 21:00 105: 24 B29L 23:00 C08L 67:02 (72) Inventor Nobuhiro Ide 2-1-1 Katada, Otsu-shi, Shiga Prefecture Toyobo Accounting Research Institute (72) Inventor Seiji Nakayama Shiga 2-1-1 Katata, Otsu-shi, Toyo F-term in Toyobo Co., Ltd. Research Laboratory (Reference) 4F071 AA47 AF21Y AF43Y AH19 BB06 BC06 4F202 AA45 AD16 AG08 AJ03 AJ09 CA27 CB02 CK81 CM26 4F203 AA45 AD16 AG08 AJ03 AJ09 DA01 DB01 DB11 4F213 AA45 AD16 AG08 AJ03 AJ09 WA06 WA39 WA87 WB02 4J002 CF041 CF101 4J029 AA03 AB01 AC02 AC03 AE01 BA01 BD02 BD07A BF25 CB 05A CB06A CB10A CC05A CH02 DB02 JE182 KB02

Claims (5)

[Claims] 1. A heat treatment wherein the crystal melting point y (° C.) satisfies the formula (1), the Vicat softening temperature z (° C.) satisfies the formula (2), and the tensile elongation is 100% or more. Mandrel made of plastic polyester elastomer. (1) y ≧ 200 + 0.5x (2) z ≧ 50 + 1.5x (where x is a numerical value representing the substantial hard segment content in the thermoplastic polyester elastomer by weight%) 2. The mandrel according to claim 1, wherein said x of said thermoplastic polyester elastomer ranges from 30 to 95. 3. The mandrel according to claim 1, wherein the substantial hard segment of the thermoplastic polyester elastomer comprises a repeating unit represented by the following chemical formula (1). Embedded image (In the formula, R represents an aromatic group having 6 to 18 carbon atoms.) 4. A structural unit other than the substantial hard segment of the thermoplastic polyester elastomer is represented by the following chemical formulas (2) to (4), and has a reduced viscosity of 0.5 to 4.0.
4. The mandrel according to claim 3, wherein Embedded image Embedded image Embedded image (In the formula, R ′ represents an alkylene group having 1 to 25 carbon atoms, G represents a polyoxyalkylene group having a molecular weight of 400 to 6000, D represents a hydrogenated dimer diol and / or a derivative thereof. A, b, c Represents the weight% occupied by each repeating unit in the whole polymer, d represents the mole% in the whole polymer, a = 30 to 95% by weight, d = 0 to 20% by mole, b
/B+c=0.01 to 0.99. ) 5. A method for producing a rubber hose, wherein a mandrel surface is coated and molded with at least a raw material for forming an inner rubber layer and a raw material for forming a reinforcing fiber material layer, and the mixture is heated and vulcanized.
A method for producing a high-pressure rubber hose, comprising using the mandrel according to any one of the above.