JPH09251811A - Resin composition for cable sheath or air hose having flexibility and low friction property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable being excellent in flexibility and having low friction property by using a polyvinyl chloride resin or a vinyl chloride copolymer resin in a specific composition ratio as a base resin of a composition composing a cable sheath. SOLUTION: A resin composition for a cable sheath having flexibility and low friction property includes 0.2-3.0 parts by weight of aliphatic amide and 55-90 parts by weight of a liquid plasticizer with respect to 100 parts by weight of any one of a polyvinyl chloride resin, a vinyl chloride-vinyl acetate copolymer resin, an ethylene-vinyl chloride copolymer resin and a tertiary copolper resin of ethylene-vinyl acetate copolymer grafted with vinyl chloride. The resin composition for the cable sheath or an air hose having flexibility and low friction desirably includes 0.2-3.0 parts by weight of erucylamide with respect to 100 parts by weight of a thermoplastic urethane resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a low friction cable having excellent flex resistance. More specifically, the present invention relates to a cable for an FA device such as an industrial robot in which a working unit such as a robot arm is mounted on a mobile device.

The present invention also relates to an air hose for compressed air for driving FA equipment.

[0003]

2. Description of the Related Art In recent years, FA equipment such as industrial robots has been rapidly spread, but in the case where a mobile equipment such as a robot arm for moving an operating portion in parallel is provided, in many cases, cable / hose support guides are provided. The device is used. Between the working part mounted on the mobile device and the fixed end on the drive and supply side, a cable that is deformable following the movement of the working part.
A hose support guide device (hereinafter referred to as a support guide device) is arranged to guide a large number of cables and air hoses.

Here, the cable in the support guide device constantly bends and stretches with the movement of the acting portion and rubs against the surroundings. While the cable is constantly bent and stretched, the outer surface of the cable, the outer surface of the cable and the outer surface of the air hose,
And the outer surface of the cable and the inner surface of the support guide continue to experience friction. As a result, if the cable jacket does not have sufficient bending resistance and surface slipperiness, the cable may be deformed and the coating may be torn due to continuous use for a short time. Finally, the conductor breaks.

As a method of imparting flex resistance to a cable jacket, it is known to use aramid fiber or a fluororesin as a reinforcing material for the cable jacket, as in JP-A-5-325651.

However, it is not preferable to use such an expensive resin for general-purpose industrial equipment because it leads to an increase in cost.

The improvement of only the slipperiness of the surface of the electric wire coating material is disclosed in Japanese Patent Application Laid-Open No. 4-74803, but no improvement or improvement in bending resistance is mentioned or suggested. The invention disclosed in the publication relates to a semi-hard coated electric wire such as a jumper wire made of a semi-hard vinyl chloride resin that originally does not require so much bending resistance, and a cable to be arranged in a support guide device as described above. Is not applicable.

On the other hand, in recent years, various tubes and hoses made of a thermoplastic urethane resin or a cable having a cable jacket made of a thermoplastic urethane resin have been used. This is because it has excellent low-temperature flexibility and oil resistance, and good mechanical properties. However, it is not sufficient for the use which requires the high degree of bending resistance and surface slipperiness as described above.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cable which can solve the above problems and which is excellent in bending resistance and low friction. That is, in an industrial robot or the like equipped with a mobile device, it is to prevent the cable guided in the deformable support guide device from following the movement of the mobile device and causing the deformation and the coating breakage. In particular, it is intended to provide a cable that significantly suppresses the meandering due to the deformation of the cable and the buckling (bending) and the breakage of the coating that occur when a large number of cables and air hoses are arranged in the support guide device.

[0010]

A resin composition for a cable jacket for bending-resistant and low-friction cables according to claim 1, comprising a polyvinyl chloride resin, a vinyl chloride / vinyl acetate copolymer resin,
100 parts by weight of either ethylene / vinyl chloride copolymer resin or terpolymer resin of ethylene / vinyl acetate copolymer grafted with vinyl chloride,
0.2 to 3.0 parts by weight of fatty acid amide, 5 parts of liquid plasticizer
5 to 90 parts by weight are blended.

According to a second aspect of the present invention, there is provided a resin composition for a cable jacket or an air hose having flexural and low friction resistance, wherein 0.2 to 3.0 parts by weight of erucylamide is mixed with 100 parts by weight of a thermoplastic polyurethane resin. It is characterized by being done.

According to a third aspect of the present invention, there is provided a resin composition for a cable jacket or an air hose having a flexural and low friction resistance, wherein the soft segment is a thermoplastic polyurethane resin 10 comprising polytetramethylene glycol or polypropylene glycol.
It is characterized in that 0.2 to 3.0 parts by weight of a primary amide of a fatty acid having 20 to 30 carbon atoms is mixed with 0 part by weight.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The composition according to claim 1 of the present invention uses a polyvinyl chloride resin or a vinyl chloride copolymer resin as a base resin of the composition constituting the cable jacket. This is because the vinyl chloride resin is inexpensive, flame retardant, and easy to process.

As the polyvinyl chloride resin, any ordinary one can be used, and a partially crosslinked one can also be used. Vinyl chloride-based copolymer resins include vinyl chloride
A vinyl acetate copolymer resin, an ethylene / vinyl chloride copolymer resin, or a terpolymer resin obtained by grafting vinyl chloride onto an ethylene / vinyl acetate copolymer is preferably used, but other resins are also possible. is there.

As the fatty acid amide added to the vinyl chloride resin, erucyl amide and oleyl amide are particularly preferable. However, other fatty acid amides such as ethylenebisamide, methylolamide, etc. can also be used.

The amount of the fatty acid amide compounded is 0.2 to 3.0 parts by weight, preferably 0.4 to 2. parts by weight, per 100 parts by weight of the vinyl chloride resin or vinyl chloride copolymer resin.
0 parts by weight. If the content of the fatty acid amide is less than 0.2 parts by weight, the flexural and low friction resistance of the cable jacket is insufficient, and if it exceeds 3.0 parts by weight, the cable jacket is molded from the composition by kneading and extrusion. It is inferior in workability.

As the liquid plasticizer, liquid plasticizers for various vinyl chloride resins such as DOP (dioctyl phthalate), phthalic acid ester type, trimellitic acid ester type, phosphoric acid ester type and fatty acid ester type are used alone. Or they can be used together. Examples of phthalic acid ester-based compounds include dioctyl phthalate, diethylhexyl phthalate, and ditridecyl phthalate, and examples of trimellitic acid-based compounds include trioctyl trimellitate and tri-n-octyl trimellitate. Examples of the fatty acid ester type include dioctyl adipate, dioctyl azelate, dioctyl sebacate and the like. Further, tricresyl phosphate can be used as the phosphoric acid ester-based liquid plasticizer, and a vegetable oil such as soybean oil which is epoxidized and stabilized can also be used.

The amount of the liquid plasticizer added is 55 to 90 parts by weight, preferably 60 to 80 parts by weight, based on 100 parts by weight of the vinyl chloride resin or vinyl chloride copolymer resin. When the amount of the liquid plasticizer is 55 parts by weight or less, sufficient flexibility cannot be obtained. Therefore, even if the amount of the fatty acid amide is sufficient, sufficient flex resistance cannot be obtained. On the other hand, when the amount of the liquid plasticizer exceeds 90 parts by weight, the cable jacket becomes excessively flexible, and the abrasion resistance is particularly deteriorated.

In the composition of claim 1 of the present invention, in addition to the above-mentioned basic components, a filler and a stabilizer, which are generally used for vinyl chloride resins, and a flame retardant, a lubricant and a colorant may be appropriately added. it can. As the filler, for example, calcium carbonate, aluminum hydroxide, aluminum silicate (calcined clay) or the like can be used, and as the stabilizer, for example, lead-based, calcium-zinc-based, tin-based, or the like can be used.

The compositions of claims 2 and 3 of the present invention are compositions for constituting a cable jacket or an air hose, which is a thermoplastic urethane resin to which an appropriate amount of a specific fatty acid amide is added.

The thermoplastic urethane resin is composed of a soft segment derived from a long chain diol component and a hard segment derived from a short chain diol component. Although the whole flows uniformly when heated and melted, after molding, the soft segment is in the rubber state to the softened state, and the hard segment is in the glass state and the physical cross-linking part (the part that has the same effect as vulcanization)
To form

As the thermoplastic urethane resin, the long-chain diol is most commonly polytetramethylene glycol (PTMG) or polypropylene glycol (PPG), and the long-chain diol is polycaprolactone (PPG).
It is also possible to use a polyester diol such as CL) or a polycarbonate polyester (PCP) or a special diol such as polybutadiene diol. The polytetramethylene glycol (PTMG) type is preferable from the viewpoint of balance between physical properties, durability and price.

The fatty acid amide added to the thermoplastic urethane resin is preferably a higher fatty acid amide having 20 to 30 carbon atoms, more preferably such a primary amide of monoene unsaturated fatty acid, and particularly preferably. Elsylamide. As the fatty acid primary amide added to the polytetramethylene glycol (PTMG) type or polypropylene glycol type thermoplastic urethane resin,
It is necessary that the carbon number is 20 to 30 (claim 3).

The amount of the fatty acid amide compounded is 0.2 to 3.0 parts by weight, preferably 0.3 to 2.5 parts by weight, based on 100 parts by weight of the thermoplastic urethane resin. If the content of the fatty acid amide is less than 0.2 parts by weight, the flex resistance and low friction resistance of the cable are insufficient, and if it exceeds 3.0 parts by weight, a cable jacket is formed from the composition during kneading and extrusion. Is inferior in workability.

A cable jacket is molded from the composition according to claim 1, 2 or 3 by extrusion molding or the like.

An air hose for driving FA equipment is molded in the same manner from the thermoplastic urethane resin composition according to the second or third aspect. The air hose is, for example, for guiding compressed air for bending and stretching the robot arm,
It is housed together with a cable in a support guide device as described below, and subjected to the same repeated bending and friction as the cable jacket of the cable. Therefore, in the thermoplastic urethane resin-based composition having pressure resistance, the composition used for the cable jacket can be directly used for the air hose.

The durability performance of the cable relating to the flex resistance and low frictional resistance of the cable jacket was evaluated as follows.

The cable used for the evaluation of durability is shown in FIG.
2 is a twisted pair vinyl insulated vinyl sheath cable (1) including four pairs of conductor wires. 0.2
Two conductors (3) each having a square millimeter cross section are covered with an insulator (4) and twisted together, and four pairs of such wires are bundled into a cylindrical cable. Here, an electromagnetic shielding layer is provided in the cross section of the cable jacket (2).

A durability performance tester and test conditions will be described with reference to FIGS.

As shown in FIG. 2, a movable end (6) is movably arranged along a horizontal rail (5), and a fixed end (7) is arranged on a table surface (9) below the rail (5). ) Is provided. A caterpillar chain type support guide device (8) is arranged between the moving end (6) and the fixed end (7). The support guide device (8) has an elongated substantially U-shape that is laid sideways when the moving end (6) comes directly above the fixed end (7),
With the movement of the moving end (6) to the left and right, it moves like a part of a chain of caterpillars traveling left and right on the table surface (9). Here, TKP0320-2B (curvature radius (R) of the caterpillar curved portion (R) 37 mm) manufactured by Tsubakimoto Chain Co., Ltd. was used as the support guide device.

To such a device, six cables (1)
Attached. In the fixed end (7) and the support guide device (8), the cable (1) is loosely wired in three stages in two stages (FIG. 3), and is clamped only by the jig at the moving end (6). The movement of the cable in the length direction is restricted.

A flex resistance test of the cable was conducted by repeatedly reciprocating the moving end (6) on the rail (5). Here, the moving stroke of the moving end on the rail is 1
The moving speed was set to 00 cm and the moving speed was set to 100 m / min.
As each cable continues to bend and stretch, it continues to rub against the adjacent cables as well as the inner surface of the support and guide device. When the cable is repeatedly bent, a meandering portion is first generated in the cable, and then the cable bends just before the coating breaks. This state was determined to be buckling. The number of times of reciprocation of the moving end before buckling was defined as the number of times of bending resistance, and the measurement was repeated 3 times and expressed in the approximate range of the measured values.

(Examples 1 to 3) Shin-Etsu Chemical Co., Ltd. was used as a base resin for the composition of the cable jacket (2).
Polyvinyl chloride resin TK-2500LS (average degree of polymerization: 2250) manufactured by Japan was used. 60, 80, and 70 parts by weight of DOP were added as liquid plasticizers to 100 parts by weight of the base resin, respectively. As the fatty acid amide, 0.5 part by weight of Armoslip E (registered trademark), which is an erucylamide product manufactured by Lion Akzo, was added. Furthermore, 6 parts by weight of tribasic lead sulfate and 1 part by weight of lead stearate are used as stabilizers, and 5 parts of calcium carbonate are used as fillers.
A composition containing 0 parts by weight was used.

Table 1 shows the results of the durability performance evaluation expressed by the number of times of bending resistance together with a list of compositions. In each of Examples 1 to 3, extremely excellent durability performance of 50,000 to 60,000 was obtained. Further, as shown in the lower end of Table 1, there was no problem in workability when molding the cable jacket.

[0035]

[Table 1] (Examples 4 to 5) In Examples 4 to 5, the amount of the fatty acid amide added was 0.25 part by weight.

In Example 4, the same conditions as in Example 3 were used except that the amount of fatty acid amide added was reduced to 0.25 parts by weight and the amount of calcium carbonate added was increased to 60 parts by weight.

In Example 5, as the fatty acid amide, 0.25 part by weight of Armoslip CP-P (registered trademark), which is an oleylamide product manufactured by Lion Akzo, was used instead of Armoslip E (registered trademark) which was an erucylamide product. Was used, and the same conditions as in Examples 3 to 4 were used except that the amount of calcium carbonate added was 40 parts by weight.

As shown in Table 1, regardless of whether erucylamide or oleylamide is used, when the amount of the fatty acid amide is 0.25 part by weight, the flexing resistance is 30,000 to 40,
000, and a cable having practically sufficient durability was obtained. However, the durability performance of the cable was slightly lower than that of Examples 1 to 3 in which 0.5 part by weight was added.

Example 6 The conditions were exactly the same as in Example 3 except that the addition amount of Armoslip E (erucylamide) was increased to 2.8 parts by weight. As shown in Table 1, the number of times of bending resistance measured was the same as in Example 3 in which 0.5 part by weight was added, and no further effect was observed by increasing the amount added. On the other hand, no problem was found in the workability shown in the lower end of Table 1.

(Comparative Examples 1 to 3) In the composition constituting the cable jacket (2), the other compositions were the same as in Example 3,
The amount of fatty acid amide added was 0, 0.1 and 0.15 parts by weight. Here, only in Comparative Example 2, Armoslip C was used instead of Armoslip E (erucylamide).
PP (oleylamide) was used. Table 2 shows the results. In Comparative Example 1 in which the amount of addition was 0 and Comparative Example 2 in which the amount of addition was 0.15 parts by weight, the number of times of flexing resistance was 20 or less, and also in Comparative Example 3 in which the amount of addition was 0.15 parts by weight, the number of times of flexing resistance was 40 or less. There wasn't. From these results, it is known that when the added amount of the fatty acid amide is 0.15 parts by weight or less, the effect of the addition is hardly seen. In comparison with the results of Examples 4 to 5, it is known that the durability performance of the cable changes dramatically between the addition amounts of 0.15 parts by weight and 0.25 parts by weight.

[0041]

[Table 2] (Comparative Example 4) The conditions were the same as in Examples 3 and 6 except that the amount of the fatty acid amide added was 3.5 parts by weight. The number of times of bending resistance is 50,000 to 6 as in Examples 1 to 3 and 6.
However, the workability in kneading and extrusion is difficult, and it is difficult to industrially mold the cable jacket. That is, even if the amount of the fatty acid amide was increased to about 3.5 parts by weight, the effect of improving the durability performance was not seen and the result was that the workability was impaired.

(Comparative Examples 5 to 6) The amounts of DOP added were 45 parts by weight and 100 parts by weight, and the other compositions were the same as in Examples 1 to 3. As shown in Table 2, the durability performance was insufficient in all cases.

In Comparative Example 5 in which the amount of DOP added is too small, the flexibility of the cable is low, so that the cable is hard to bend and the R of the bend of the cable is increased to expand the curvature of the support guide device (8). Not only does it hinder the movement of the moving end (6), but in actual use conditions,
This causes contact or collision with other members adjacent to the support guide device, causing damage to the member and the support guide device. Therefore, it was determined to be unusable when the swelling of the curved portion of the support guide device (8) was clearly observed. Continue to reciprocate the moving end (6), and
Buckling occurred at 00 to 30,000. It is probable that because the cable had low flexibility and poor flexibility, friction in the support guide device increased, and durability performance was insufficient.

On the contrary, when the amount of DOP added was excessive, the number of times of flexing was 5,000 to 10,000, which was a remarkably low value as compared with the examples. It is probable that the durability performance represented by the number of flexing cycles was insufficient because the cable became excessively flexible and particularly low friction property could not be obtained.

The above results show that the effect of the present invention can be obtained only by the synergistic effect of an appropriate amount of DOP and an appropriate amount of fatty acid amide.

(Examples 7 to 9) A vinyl chloride copolymer resin was used in place of the polyvinyl chloride resin as the base resin of the composition constituting the cable jacket (2). Same as 3. The following three types of resins were used as the vinyl chloride copolymer resin. Ethylene-
Ryuron E-2800 (average degree of polymerization 2750) manufactured by Tosoh Corporation, which is a vinyl chloride copolymer resin, vinyl acetate-
VA-PVC resin, which is a vinyl chloride copolymer resin, manufactured by Chisso Corporation, Nipolit MH (average degree of polymerization: 150
0) and ZEST GR5F (average degree of polymerization 1400) manufactured by Shin-Daiichi Vinyl Co., Ltd., which is a terpolymer resin obtained by grafting vinyl chloride onto an ethylene-vinyl acetate copolymer.

As shown in Table 3, even when these copolymer resins were used, the same results as when the polyvinyl chloride resin was used were obtained.

[0048]

[Table 3] (Examples 10 to 12) As a resin composition that constitutes the cable jacket (2), 0.3 parts by weight of each of the thermoplastic urethane resin Kuramil U-9185 manufactured by Kuraray Co., Ltd. and Armoslip E (registered trademark) is used. , 0.5 parts by weight and 2.5
What added the weight part was used.

Table 4 shows the results of the durability performance evaluation represented by the number of flex resistances. 30,000 to 4 in Example 10
50,000, in Examples 11-12, 50,000
A very excellent durability performance of -60,000 was obtained. Further, as shown in the lower end of Table 4, there was no problem in workability when molding the cable jacket.

[0050]

[Table 4] (Comparative Examples 7 to 8) In Comparative Examples 7 and 8, the addition amount of Armoslip E (registered trademark) was 0 parts by weight and 0.1 parts by weight, respectively.
The same procedure was performed as in Examples 10 to 12 except that the parts by weight were used. It is known that the number of times of flexing is extremely low at 1 to 5, and that the durability performance cannot be obtained when the fatty acid amide is not added or when the addition amount is insufficient even if it is added.

(Comparative Examples 9 to 10) In Comparative Examples 9 and 10, the armoslip E was replaced with the armoslip CP-P.
0.5 part by weight and 1.0 part by weight,
The same as the above. No bleeding of fatty acid amide was observed on the surface of the cables of Comparative Examples 9 and 10.
That is, Armoslip CP-P was included in the resin because the compatibility with the above-mentioned thermoplastic urethane resin was too high, and no exudation to the resin surface was observed.

Both erucylamide (Armoslip E) and oleylamide (Armoslip CP-P) are the primary amides of monoene unsaturated fatty acids and differ only in that they have 22 and 18 carbon atoms, respectively. There is. Therefore, from comparison with Examples 10 to 12, it is known that in this type of fatty acid amide, the performance of imparting flex resistance to the thermoplastic urethane resin changes critically around 20 carbon atoms.

Comparative Example 11 In Comparative Example 11, the addition amount of Armoslip E (registered trademark) was 3.5 parts by weight.
The flexing resistance is 50,000, which is the same as in Examples 11 to 12.
However, the workability in kneading and extrusion is difficult, and it is difficult to industrially mold the cable jacket. That is, the amount of fatty acid amide was 3.
Even if the amount was increased to about 5 parts by weight, the effect of improving the durability performance was not seen and the workability was impaired.

[0054]

[Table 5] (Example 13) A tube was formed from the same composition as in Example 11 with the same diameter and thickness as the cable jacket (2). The thermoplastic urethane resin is used as a pressure resistant hose, and originally has sufficient pressure resistance against compressed air and its reliability. A bending resistance test was conducted in the same manner as in the case of the cable (2) while keeping the inside of the tube at a positive pressure of about 1 atm with compressed air, and the bending resistance was 50,000 times or more. .

[0055]

EFFECTS OF THE INVENTION As a cable jacket, a cable made of a composition obtained by adding a relatively large amount of a liquid plasticizer and a suitable amount of fatty acid amide to a vinyl chloride resin or a copolymer resin of vinyl chloride and vinyl acetate is used. As a result, a low-friction cable having excellent bending resistance is provided. In particular, in an FA device in which an action part such as a robot arm is mounted on a mobile device,
A cable that is connected to the working portion and is disposed in a deformable support guide device following the movement of the working portion provides an inexpensive and long-term continuous use cable.

Similarly, by using a thermoplastic urethane resin composition containing 0.2 to 3.0 parts by weight of a fatty acid amide as a cable jacket, flex resistance and low friction properties are similarly obtained. Give the cable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cable used for evaluating durability performance.

FIG. 2 is a schematic diagram of a durability test apparatus.

FIG. 3 shows the arrangement of cables at the fixed end of the durability test apparatus.

[Explanation of symbols]

 1 twisted pair vinyl insulated vinyl sheath cable 2 cable jacket 3 conductor 4 insulator 6 moving end 7 fixed end 8 support guide device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08L 75/04 NGB C08L 75/04 NGB // H01B 7/18 H01B 7/18 B

Claims (3)

[Claims] 1. A polyvinyl chloride resin, a vinyl chloride / vinyl acetate copolymer resin, an ethylene / vinyl chloride copolymer resin, or a terpolymer resin obtained by grafting vinyl chloride onto an ethylene / vinyl acetate copolymer. Any of resin 1
A resin composition for a flex-resistant low-friction cable jacket, characterized in that 0.2 to 3.0 parts by weight of a fatty acid amide and 55 to 90 parts by weight of a liquid plasticizer are blended with respect to 00 parts by weight. Stuff. 2. A flexure and low friction resistant cable jacket or air hose, characterized by comprising 0.2 to 3.0 parts by weight of erucylamide with respect to 100 parts by weight of a thermoplastic polyurethane resin. Resin composition. 3. A primary amide of a fatty acid having 20 to 30 carbon atoms in an amount of 0.2 to 3. per 100 parts by weight of a thermoplastic polyurethane resin having a soft segment of polytetramethylene glycol or polypropylene glycol.
A resin composition for a cable jacket or an air hose having bending and low friction resistance, which is characterized by containing 0 part by weight.