JPH0229019B2 - NETSUKASOSEIJUSHITASOKANJOTAI - Google Patents

Description

[Detailed description of the invention]

The present invention particularly relates to a thermoplastic resin multilayer tubular body having excellent flexibility and impact resistance at low temperatures. The tubular body made of thermoplastic resin must not rust;
It has the advantages of being lightweight, having excellent chemical properties, and being easy to process, and includes pipes, tubes, and hoses whose tubes are coated with metal fibers, synthetic fibers, rubber, etc. It is widely used for transporting various liquids, gases, and solids such as water, oil, gasoline, air, and powder and granules. Among these, tubular bodies made of polyamide resin have excellent mechanical strength, chemical properties such as chemical resistance, and gas barrier properties, but their major drawback is that they are insufficiently flexible. This can be mentioned. As means for improving the flexibility of polyamide resin tubular bodies, attempts have been made to include a method of adding a plasticizer to the material resin, and a method of molding the tubular body into a bellows shape. However, even if a plasticizer is added, the flexibility of the tubular body is often not always sufficient depending on the application, and the plasticizer may elute, especially in applications where it is used in contact with a solvent. There is a problem. Moreover, even if a certain degree of flexibility improvement can be expected by adding a plasticizer, the impact resistance of the tubular body, especially at low temperatures, will be reduced, which will inevitably limit its use. In addition, tubular bodies made of polyamide resin called bellows tubes and corrugated tubes are complicated to mold.
In addition, the pipe resistance is large, so it is not suitable for transporting liquids or solids. Therefore, the present inventors have improved the above-mentioned drawbacks to satisfy the mechanical strength, chemical properties, etc., and in some cases, the gas barrier properties, as well as to improve the flexibility and impact resistance at low temperatures. As a result of studies aimed at obtaining a balanced polyamide resin tubular body, it was discovered that a multilayer tubular body made of a polyamide resin and a specific resin meets the above objective. That is, the present invention comprises () a polyamide resin, () 90 to 20% by weight of polyamide units represented by the following formula (1) and/or (2), and a polyester represented by the following formula (3) and/or (4). unit 10
The present invention provides a thermoplastic resin multilayer tubular body characterized by a laminated structure with a polyesteramide resin comprising ~80% by weight. (Here, k is 10 or 11, m and n are each 6~
Must be an integer of 12 and satisfy m+n≧15. P is 3~
is an integer of 11, R ₁ is an aliphatic or alicyclic divalent group having 2 to 8 carbon atoms, and R ₂ is an aliphatic or alicyclic divalent group having 6 carbon atoms.
~12 aliphatic or aromatic divalent groups. ) Polyamide resins used in the present invention include nylon 11, nylon 12, nylon 610, nylon
612, nylon 6, and nylon 66, or copolymerized polyamide resins of these with each other, and these polyamide resins are combined with at least one of other resins such as modified polyolefin resins, polyether ester amide resins, and polyester amide resins. Blends of small proportions of seeds can also be used. Among these, polyamide resins with a relatively low amide group concentration such as nylon 11 and nylon 12, and blends of these with the other resins mentioned above, are particularly effective in terms of flexibility, low-temperature impact resistance, etc. Furthermore, nylon 6, nylon 66, or a copolymerized polyamide resin thereof is particularly effective in terms of resistance to freon gas permeation. In addition to plasticizers, these polyamide resins also contain various lubricants such as stearic acid, stearic acid metal salts, ethylene bis stearyl amide, methylene bis stearyl amide, talc, silicates, titanium oxide, nucleating agents, heat resistant agents, Various additives such as weathering agents, ultraviolet absorbers, flame retardants, anti-wear agents, and reinforcing agents can be mixed and used. The polyamide unit, which is one of the constituent components of the polyesteramide resin () used in the present invention, is a lactam or amino acid having 11 or 12 carbon atoms represented by the above formula (1), or a carbon atom represented by the above formula (2). Straight chain aliphatic diamine with 6 to 12 atoms and 6 carbon atoms
It is derived from raw materials such as equimolar salts with ~12 linear aliphatic dicarboxylic acids (however, m+n≧15), and typical examples of raw materials include laurolactam, 11-aminoundecanoic acid, 12-aminoundecanoic acid, etc. -Aminododecanoic acid, hexamethylenediamine azelate, hexamethylenediamine sebacate, hexamethylenediamine dodecanedioate, undecamethylenediamine sebacate, undecamethylenediamine dodecanedioate, etc. These can be used alone or in the form of a mixture of two or more. The polyester unit, which is another component of the polyesteramide resin, is a lactone having 4 to 12 carbon atoms represented by the above formula (3), or the above (4).
It is derived from an aliphatic or alicyclic diol having 2 to 8 carbon atoms and an aliphatic or aromatic dicarboxylic acid having 6 to 12 carbon atoms, and typical raw materials include butyrolactone, Lactones such as caprolactone, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, cyclohexanedimethanol, etc. diols, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, phthalic acid, isophthalic acid,
Dicarboxylic acids such as terephthalic acid can be mentioned. Among the polyester units, aliphatic units are preferred from the viewpoint of flexibility as those derived from dicarboxylic acids. The appropriate composition ratio of the polyamide unit and polyester unit is 90 to 20% by weight to 10 to 80% by weight,
As long as it is within this range, the raw material composition and copolymerization amount may be appropriately selected depending on the purpose of use. If the composition ratio of polyamide units exceeds 90% by weight, flexibility will not be sufficient, and if the composition ratio of polyester units exceeds 80% by weight, practical heat resistance cannot be maintained in the case of aliphatic polyester. Aromatic polyesters are not preferred because they lack flexibility. An example of a method for producing such a polyesteramide resin is to prepare a bulk mixture of polyamide-forming components and polyester-forming components in the presence of a conventional esterification catalyst such as a tetraalkyl titanate or a titanium oxalate metal salt to give a 150-260% An example of this method is to carry out a heating reaction at a temperature of 10°C, followed by heating polycondensation at 200 to 270°C under a reduced pressure of 10 mmHg or less, preferably 1 mmHg or less, but the production method is not limited to this. It is also possible to employ a method in which one of the polyester prepolymers is subjected to condensation polymerization in the presence of the other prepolymer, or a method in which both prepolymers are condensed and polymerized together. The degree of polymerization of polyesteramide resin is not particularly limited, but it is generally 0.5 in orthochlorophenol.
Weight%, relative viscosity measured at 25°C is 1.3
~3.0 is preferably used. Various polymer blends and various additives similar to those for the polyamide resin can be applied to this polyesteramide resin as well. The layer structure of the polyamide resin and polyesteramide resin in the multilayer tubular body of the present invention has various required properties depending on the application, so it can be freely selected.
For example, in the case of two layers, one resin may serve as either the inner layer or the outer layer of the tubular body, and in the case of three layers, either resin can be selected as the intermediate layer. Regarding the number of laminated layers, it is two or more layers, and of course four or more layers may be used. Furthermore, the thickness structure of the laminated layers can be varied depending on the required characteristics such as flexibility, impact resistance, mechanical strength, economic efficiency, etc. Generally, the thickness of one resin layer is 5% to 95% of the total thickness.
%, preferably in the range of 10 to 90%. However, if the polyamide resin layer is 5% or less (the polyesteramide resin layer is 95% or more), the mechanical properties, chemical resistance, and
This is not preferable because it worsens the situation. On the other hand, if the polyamide resin layer accounts for 95% or more (the polyesteramide resin layer accounts for 5% or less), the effect of improving flexibility is hardly exhibited, which is undesirable. The multilayer tubular body of the present invention can be produced by a common coextrusion method, for example, in the case of a two-layer tubular body, the two resin layers are separately fed to two extruders, and the two molten resins are separated separately. After supplying pressure into a common die and forming each flow into an annular flow,
They are merged in a die to form a two-layer tubular body, then co-extruded outside the die and shaped to the desired dimensions using a normal sizing method and cooling method. For the body, 3
Make three layers using the above method using a stand extruder, or
Alternatively, using two extruders, the resin forming the outer layer and inner layer is extruded in one flow from the extruder, and then the ring is divided into two in the die, with the inner flow controlling the inner layer and the outer flow controlling the outer layer. After forming, a flow of molten resin from another extruder is also fed in an annular manner between the inner and outer annular molten resin divided into two parts in the die, and the three parts are joined in an annular shape. A typical method is co-extrusion to the die side, sizing and cooling using the usual method. In this case, the inside of the extruder and die plasticizes and extrudes the resin, so it is necessary to maintain a temperature higher than the melting temperature of the resin.Especially in the die where flows from separate extruders join, the melting temperature is generally high. The temperature is maintained to match the resin. Note that the method for manufacturing the multilayer tubular body of the present invention is not limited to the coextrusion method; instead, a single-layer tubular body made of one resin is made in advance, and this tubular body is coated with the other resin to form a multilayer tubular body. It may be a method of making the body. The thus obtained multilayer tubular body of the present invention has excellent mechanical properties such as strength, chemical properties such as chemical resistance, and has significantly improved flexibility and impact resistance at low temperatures, making it suitable for various uses. Expected to be applied. The present invention will be explained in further detail by giving examples below. Examples 1 to 8, Comparative Examples 1 to 2 Two extruders were used, and one extruder was charged with nylon 11 [Toray Industries, Inc., Rilsan BESNO TL].
It was extruded at 210-220°C and formed into an annular flow in a die at 210°C. In addition, one extruder has dodecane amide units and butylene dodecanedioate units (abbreviation: nylon 12/PBD) or undecane amide units and butylene dodecanedioate units (abbreviation: nylon 12/PBD).
11/PBD) weight ratio is 80:20% or
A 60:40% polyester amide with the composition shown in Table 1 is introduced, extruded at 170 to 180°C, introduced to the outside of the nylon 11 in the die described above, and then formed into an annular flow by merging the outer and inner annular flows. I let it happen. This combined product is then extruded through a die and cooled while being sized in a vacuum tank to form a two-layer tubular body with an outer diameter of 8 mm, an inner diameter of 6 mm, and a thickness ratio of outer layer and inner layer of 90:10% or 30:70%. Molded. On the other hand, as comparative examples, unplasticized nylon 11 (Rilsan BESNO TL) single layer and plasticized nylon 11 (Rilsan BESNO P40 TL) were used.
A single-layer tubular body having an outer diameter of 8 mm and an inner diameter of 6 mm was molded. Table 1 shows the results of evaluating the physical properties of these various tubular bodies. The flexibility of the tube was measured by measuring the load required when bending both ends of a tubular body cut to a length of 20 cm to the minimum bending radius and converting it into stress, which was used as a measure of flexibility. The impact strength was measured by placing 10 tubular bodies cut into 8cm lengths on a flat surface in an atmosphere of -40℃, and measuring 5.53Kg・m.
The number of broken pieces when a weight with an energy of

【table】

[Table] Tensile strength is measured at a strain rate of 20 mm/min, a temperature of 2 ± 1°C, and a humidity of 65 ± 5 for a tubular body cut into 15 cm lengths.
A tensile test was conducted under conditions of % to determine the tensile strength at break. As is clear from Table 1, the tubular body of the present invention has mechanical properties such as strength within a range that does not pose any practical problems, and is an excellent tube that has both flexibility and impact resistance at low temperatures. . Examples 9-12 Same as Examples 1-8, using two extruders,
In one extruder, the same nylon as in Examples 1 to 4 was used.
12/PBD with a composition ratio of 80/20% or 60/40%
of polyesteramide, extruded at 170 to 180°C to form a circular flow in a die at 210°C, and nylon 11 (Toray Industries, Inc., Rilsan BESNO TL) was added to one extruder. Extrusion is carried out at 210-220℃, the flow is divided into two annular shapes and guided to flow outside and inside the polyester amide in the aforementioned die, and then the outside, middle and inside flows are merged to create an annular shape from the three layers. The flow is extruded to the die side and sizing cooling is performed.The outer diameter is 8 mm, the inner diameter is 6 mm, and the thickness ratio of the outer layer, middle layer, and inner layer is 10:80:10% or 30:40:30.
A three-layered tubular body was molded so that the amount of The evaluation results are shown in Table 2.

[Table] As is clear from Table 2, the three-layer tubular body of the present invention has mechanical strength and mechanical properties within a range that poses no practical problems, and is an excellent tube that has both flexibility and impact resistance at low temperatures. be. Example 12, Comparative Example 3 In the same manner as Examples 1 to 8, nylon 6 (CM1041 manufactured by Toray Industries, Inc.) was charged into one extruder, and the
Extrusion was carried out at 260°C, and in another extruder, nylon 12/PBD with a composition ratio of 60 to 40% polyester amide was charged, as in Examples 2 and 4, and extruded at 170 to 180°C, with nylon 6 forming the inner layer. A two-layer tube was obtained, constituting the outer layer of polyesteramide. The outer diameter of this tube was 8 mm, the inner diameter was 6 mm, and the thickness ratio of the outer layer to the inner layer was 85%:15%. on the other hand,
As a comparative example, a tubular body made of a single layer of nylon 6 (CM1041) with an outer diameter of 8 mm and an inner diameter of 6 mm was molded. This evaluation result and the aforementioned Comparative Example 2 are shown in Table 3. In Teub's Freon 12 gas permeation test, one Freon 12 gas was placed inside a tubular body cut into 30cm lengths.
0.6±0.1 gr/cm ³ was sealed and left in an air thermostat at 100° C. for 96 hours, weight change was measured, and permeation amount (gr/m/72 hr) was calculated.

[Table] As is clear from Table 3, the tubular body of the present invention has both flexibility and impact resistance at low temperatures, and is also excellent in Freon 12 gas permeability.

Claims (1)

[Scope of Claims] 1. A polyamide resin and () 90 to 20% by weight of polyamide units represented by the following formula (1) and/or (2), and a polyamide unit represented by the following formula (3) and/or (4). A thermoplastic resin multilayer tubular body characterized by a laminated structure with a polyesteramide resin comprising 10 to 80% by weight of polyester units. (Here, k is 10 or 11, m and n are each 6~
Must be an integer of 12 and satisfy m+n≧15. P is 3~
is an integer of 11, R ₁ is an aliphatic or alicyclic divalent group having 2 to 8 carbon atoms, and R ₂ is an aliphatic or alicyclic divalent group having 6 carbon atoms.
~12 aliphatic or aromatic divalent groups. )