JPH05163399A - Flexible resin composition - Google Patents

Abstract

PURPOSE:To improve flexibility, etc., by compounding chlorinated polyethylene, a specific hydrogenation product of a styrene-isoprene block copolymer, a low- density PE, a powdered PE, an org. unsatd. silane, and a free-radical generator. CONSTITUTION:100 pts.wt. polymer component comprising 10-50wt.% chlorinated PE, 15-65wt.% hydrogenation product of a styrene-isoprene block copolymer having a styrene content of 10-35wt.%, 10-60wt.% low-density PE, and 1-7wt.% powdered PE is compounded with 1-5 pts.wt. org. unsatd. silane of the formula: RR'SiY2 (wherein R is a monovalent, olefinically unsatd. hydrocarbn group; Y is a hydrolyzable group; and R' is Y or a monovalent hydrocarbon group except an aliph. unsaid. hydrocarbon group) and 0.1-1 pt.wt. free-radical generator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the use of conventional rubber products such as coatings for electric wires and cables, hoses and sheets, etc., in which the deterioration of mechanical properties and electrical properties due to oil adhesion and immersion is remarkably suppressed. The present invention relates to a flexible resin composition intended to be applied to the conventional fields.

[0002]

2. Description of the Related Art Conventionally, as a simple method for crosslinking polyolefin such as polyethylene or ethylene propylene rubber, after graft-reacting an organic unsaturated silane with the polyolefin in the presence of a free radical generator, silane-grafting is carried out. A so-called silane cross-linking method is generally known in which this silane graftmer is brought into contact with water to crosslink in the presence of a silanol condensation catalyst. For example, JP-B-48-1711 and JP-A-57-49109 are available. Although a polyolefin-based rubber insulated wire having rubber elasticity can be manufactured by this method, the fact is that it is difficult to put into practical use due to the following problems. That is, generally the polyolefin having rubber elasticity has a low softening temperature of around 40 ° C., and the pellets of the polyolefin cause blocking at the throat portion of the extruder hopper during storage or during extrusion,
Pellets adhered to the screw feed section of the extruder, and the amount of extrusion varied or the amount of extrusion gradually decreased, which hindered stabilization and greatly hindered its practical application.

As another method, a polyolefin-based rubber insulated wire can be manufactured by passing a vulcanization process of rubber. However, the mechanical strength is low and the vulcanization process increases the manufacturing speed of the cable. Financial problems are inevitable. That is, since there is a disadvantage that external force is applied to the coating layer in the take-up machine or the winding drum immediately after extrusion coating to cause permanent deformation of the coating layer, it is necessary to take sufficient cooling process and vulcanization process. Therefore, it is necessary to slow down the cable manufacturing line speed and to remarkably lengthen the cooling water tank, which inevitably causes economic problems. In order to solve such a problem, as seen in JP-A-3-56517,
A system using an ethylene-propylene-diene terpolymer and an ethylene-methyl methacrylate copolymer as a base resin was invented, and a resin composition having good processability and good rubber elasticity was provided. However, these resin compositions are remarkably deteriorated in oil resistance, that is, in mechanical properties after being immersed in oils, and thus their applications are limited to places where oils may not be attached.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves these problems and remarkably suppresses deterioration of mechanical properties and electrical properties due to adhesion of oils, immersion, and rubber-like flexibility. It is intended to provide a resin composition having the above.

[0005]

The present invention provides the following (a) to
A composition comprising the component (f), wherein the component (a) is 10-50.
10% by weight, (b) 15 to 65% by weight, (c) 10 to 60% by weight, and (d) 1 to 7% by weight.
1 to 5 parts by weight of (e) and 0.1 parts of (f) with respect to 0 parts by weight
It is a flexible resin composition characterized by containing 1 to 1 part by weight. (a) Chlorinated polyethylene. (b) A hydrogenated derivative of a styrene-isoprene-block copolymer having a styrene content of 10 to 35 wt%. (c) Low density polyethylene. (d) Powdered polyethylene. (e) Organic unsaturated silane. (f) Free radical generator.

The component (a) of the present invention is added for the purpose of improving the oil resistance of the resin composition. The amount of these added is 10 to 50% by weight of the base polymer, preferably 15 to
40% by weight. If it is 10% by weight or less, it is difficult to obtain the desired effect of improving oil resistance, and if it is 50% by weight or more, flexibility,
It is not practical because it causes deterioration of heat resistance and mechanical properties.

The component (b) of the present invention is added for the purpose of maintaining the flexibility of the resin composition, suppressing the decrease in the graft ratio of silane and improving the crosslinking ratio. The addition amount of these is 15 to 65% by weight of the base polymer, preferably 30
~ 50% by weight. If it is less than 15% by weight, flexibility and cross-linking rate are lowered, and if it is more than 65% by weight, workability becomes poor and the product becomes expensive, which is not practical.

The component (c) of the present invention is added for the purpose of maintaining mechanical properties. Since the components (a) and (b) are more expensive than the component (c), 10 to 50% by weight of the component (a), (b)
Increasing the amount of component (c) within the range of 15 to 65% by weight improves mechanical properties and is economically advantageous.

The component (d) of the present invention is for impregnating the organic unsaturated silane, which is a liquid substance, and uniformly dispersing it when the reaction is carried out by adding an appropriate amount of the organic unsaturated silane and the free radical generator. is there. When the component (d) is not used, the liquid substance is only attached to the pellet surface.
During extrusion, it cannot be dispersed evenly because it adheres to the wall surface inside the hopper or hangs down at the hopper mouth.

The component (e) of the present invention is to be grafted to the base resin so as to serve as a cross-linking point between the base resins. The organic unsaturated silane used in the present invention has a general formula RR'SiY ₂ (R is a monovalent olefin unsaturated hydrocarbon group, Y is a hydrolyzable organic group, and R'is an aliphatic unsaturated hydrocarbon. Other than monovalent hydrocarbon groups or compounds represented by Y) are used. It is desirable to use an organic unsaturated silane in which R'is the same as Y and is represented by the general formula RSiY ₃ , and examples thereof include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, allyltrimethoxysilane, and allyltriethoxy. Examples include silane. The addition amount of these is 1 to 5 parts by weight, preferably 2.5 to 3.5 parts by weight. If the amount is less than 1 part by weight, sufficient grafting does not occur, and if the amount is more than 5 parts by weight, molding defects occur and it is not economical.

The component (f) of the present invention acts as an initiator of the silane graft reaction. As the free radical generator used in the present invention, various organic peroxides having a strong polymerization initiation action are used. The addition amount of these is 0.1 to 1 part by weight, preferably 0.1 to 0.3 part by weight. When the amount is less than 0.1 part by weight, the silane graft reaction does not proceed sufficiently, and when the amount is more than 1 part by weight, the extrusion processability is deteriorated and the molding surface is deteriorated.

As the other additive, the flexible composition of the present invention may optionally contain a commonly used additive such as an antioxidant, a neutralizer, an ultraviolet absorber, an antistatic agent, a pigment, a dispersant and a lubricant. , Thickeners, foaming agents, metal deterioration preventing agents, antifungal agents, flow regulators, etc., flame retardants of phosphorus and phosphine derivatives, other inorganic fillers, crosslinking agents, crosslinking aids, etc.
Alternatively, other synthetic resin may be contained.

[0013]

EXAMPLES Examples and comparative examples will be described below.
According to the blending ratios shown in Tables 1 and 2, first, the base polymer was kneaded and granulated using a pressure kneader. This mixture was mixed with an organic unsaturated silane and a free radical generator, kneaded with a single screw extruder at an extrusion temperature of 120 to 180 ° C., and strand cut to granulate to obtain a silane graftmer. The resulting silane grafter and catalyst masterbatch (100 parts by weight of low-density polyethylene, 1 part by weight of dibutyltin dilaurate and an antioxidant kneaded into pellets) were mixed at a ratio of 19: 1, The mixture was kneaded using a single-screw extruder, extruded into a tape having a thickness of 1 mm and a width of 100 mm, and then immersed in warm water for crosslinking treatment. Various test pieces for measurement were prepared using this tape-shaped sample. Using this test piece, tensile test, heat aging test,
An oil resistance test was conducted. A 6 mm thick press sheet was prepared using the tape-shaped sample after extrusion, and the hardness of the composition was measured using this press sheet. In addition, the extrusion processability during extrusion was evaluated.

[0014]

[Table 1]

[0015]

[Table 2]

1: Daiso chlorinated polyethylene 2: Showa Denko chlorinated polyethylene 3: Kuraray styrene-isoprene-block copolymer hydrogenated derivative 4: Showa Denko Sholex (low density polyethylene) 5: Nippon Synthetic Rubber ethylene-propylene-diene ternary copolymer 6: Sumitomo Chemical Co., Ltd. ethylene-methyl methacrylate copolymer 7: Sumitomo Seika powder polyethylene 8: Shin-Etsu Chemical vinyltrimethoxysilane 9: Nippon Oil & Fat Dicumyl Peroxide 10: Kyowa Mug # 150 manufactured by Kyowa Kagaku 11: Stearic acid 12: Pigment Black: VALCAN 9A-32 3.0 parts by weight 13: According to JIS K6760. 14: According to JIS K6760. Residual rate of tensile strength after 136 ° C for 168 hours. 15: According to JIS K6760. JIS 2 oil 70 ° C, weight change rate after immersion for 22 hours 16: According to JIS K6301. 17: 50mmφ single-screw extruder 120-150-170-180-170 ℃ L / D: 20 Compression ratio 3.5 Tape die thickness 1mm Evaluation Excellent>Good>Acceptable> Impossible, in order of acceptable level. ..

As can be seen from the table, the materials shown in Examples 1 to 6 maintain flexibility, exhibit better oil resistance by using chlorinated polyethylene in combination with the base resin, and have excellent mechanical properties. Shows properties and processability. On the other hand, Comparative Example 1 using a conventional ethylene-propylene-diene terpolymer has poor oil resistance, and Comparative Example 2 containing a large amount of chlorinated polyethylene has reduced tensile strength, heat resistance and flexibility. And the workability is poor. The oil resistance was inferior in Comparative Example 3 in which chlorinated polyethylene was not added. Further, in Comparative Example 4 in which the amount of the hydrogenated derivative of the styrene-propylene-block copolymer added was large, the processability was poor. In Comparative Example 5 in which the amount of the organic unsaturated silane added was large, the tensile strength was low and the heat resistance was poor. Comparative Example 6 in which the addition amount of the free radical generator is large has poor processability.

[0018]

Industrial Applicability According to the present invention, it is possible to obtain a resin composition which remarkably suppresses the deterioration of mechanical properties and electrical properties due to the adhesion and immersion of oils and which has rubber-like flexibility.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H01B 3/44 Z 9059-5G

Claims (1)

[Claims] 1. A composition comprising the following components (a) to (f), wherein (a) is 10 to 50% by weight and (b) is 15 to 65:
% By weight, 10 to 60% by weight of (c) and 1 to 7% by weight of (d)
1 part of (e) per 100 parts by weight of the base polymer consisting of
To 5 parts by weight and 0.1 to 1 part by weight of (f) are contained in the flexible resin composition. (a) Chlorinated polyethylene. (b) A hydrogenated derivative of a styrene-isoprene-block copolymer having a styrene content of 10 to 35 wt%. (c) Low density polyethylene. (d) Powdered polyethylene. (e) Organic unsaturated silane. (f) Free radical generator.