JP2023150998A - Non-halogen-based fire retardant resin composition and wiring material - Google Patents

Abstract

To provide a non-halogen-based fire retardant resin composition excellent in mechanical characteristics and capable of forming a molding that develops high fire retardancy without applying excessive load, and a wiring material having a coating layer formed with the composition around an outer peripheral surface of a conductor.SOLUTION: A non-halogen-based fire retardant resin composition that contains, based on 100 pts.mass of a base resin containing 60 to 95 mass% of a specific ethylene-vinyl acetate copolymer having an MFR of 2 to 15 g/10 min and 5 to 40 mass% of an acid-modified polyolefin polymer. 100 to 250 pts.mass of a metal hydrate, 2 to 30 pts.mass of clay ore and quaternary ammonium salt in total, and satisfies the following [A] and [B], and a wiring material having a coat layer formed with the composition on an outer peripheral surface of the conductor. [A] The wiring material having the coat layer with a thickness of 2.1 m must pass the single-line combustion test. [B] The char formation strength after the single-line combustion test must be 10 gf or more, and the average strength must be 5 gf or more.SELECTED DRAWING: None

Description

The present invention relates to a non-halogen flame retardant resin composition and a wiring material using the same.

Wiring materials (insulated wires or cables, (electrical) cords, optical fiber cores, optical fiber cords, optical cables, etc.) are used to transport power and information. In particular, transmission using optical fibers has become mainstream for information transmission because of its large transmission capacity and low transmission loss. Among optical fibers, multicore optical fiber cables (also referred to as optical cables) containing a large number of optical fibers or optical fiber tapes are used for long-distance, large-capacity transmission. For example, data centers that collectively manage information have been built and are in operation in various places, and the amount of information handled there is enormous, so multi-core optical cables are used to transmit information between data centers. Similarly, optical cables are used for information transmission between data servers within a data center.
These wiring materials usually have a coating layer formed of various resin compositions on the outer peripheral surface of the conductor or fiber core to protect the conductor or fiber core and ensure electrical insulation. In addition, in order to prevent the spread of fire in the event of a fire, wiring materials installed inside houses such as data centers, especially optical cables, are made of flame-retardant wiring materials that have a coating layer made of a flame-retardant resin composition. Needed. Furthermore, in the event of a fire, it is recommended to use non-halogen flame retardants, which do not contain halogen-containing flame retardants, and are said to emit low smoke and toxic gases, not only to prevent the spread of fire but also to prevent personal injury. Recommended.

For such a coating layer, a resin composition containing a non-halogen flame retardant, a metal hydrate, and various additives as a flame retardant is being considered. For example, Patent Document 1 describes a non-halogen flame-retardant resin composition in which a metal hydroxide surface-treated with a specific amount of a fatty acid-based treatment agent and a silane coupling agent is added to a polyolefin-based resin. To 100 parts by mass, add 150 to 300 parts by mass of the metal hydroxide, 0.5 to 10 parts by mass of the hindered phenol antioxidant, and 0.2 to 5 parts by mass of the sulfur antioxidant. A non-halogen flame retardant resin composition formed by Further, Patent Document 2 describes, “A resin composition containing a total of 2 to 15 parts by mass of a clay mineral and a quaternary ammonium salt with respect to 100 parts by mass of a base resin, wherein the base resin is an acid-modified polyolefin. A resin composition containing 10 to 30% by mass of a resin and 70 to 90% by mass of a polyolefin resin (X) other than the acid-modified polyolefin resin is described. Further, Patent Document 3 discloses a polymer, a nanoclay, and a secondary filler (selected from the group consisting of aluminum hydroxide, magnesium carbonate, magnesium hydroxide, hydromagnesite, huntite, boehmite, and bauxite), Compositions are described in which a cohesive char is formed during combustion. Furthermore, Patent Document 4 states that ``Ethylene/vinyl acetate has a vinyl acetate content of 27 to 46% by weight and a melt flow rate (JIS K7210-1999, 190°C, 2160g load) of 0.01 to 0.6g/10 min. A flame-retardant resin composition containing 200 to 300 parts by weight of metal hydrate (A) and 5 to 60 parts by weight of zinc borate (B) per 100 parts by weight of the copolymer. has been done.

Japanese Patent Application Publication No. 2006-084524 Japanese Patent Application Publication No. 2020-164695 Special Publication No. 2002-543260 Japanese Patent Application Publication No. 2006-001988

Although it depends on the type of flame retardant, flame retardancy development mechanism, etc., non-halogen flame retardant resin compositions contain a large amount of metal hydrates etc. to achieve a predetermined flame retardancy, as in the above patent document. is expressed. When such a non-halogen flame retardant resin composition is burned, it usually forms a combustion residue called char. However, if the content of metal hydroxide or the like in the resin composition is insufficient, char with a brittle and thin structure is formed during combustion, and combustion progresses, resulting in poor flame retardancy. Therefore, in order to form a char capable of exhibiting a predetermined flame retardancy, a large amount of a char-forming component such as a metal hydroxide is usually contained as described above. Therefore, non-halogen flame-retardant resin compositions have high melt viscosity, making it difficult to manufacture (molding) wiring materials without applying an excessive load (poor moldability), and even if they can be manufactured, they cannot be formed into a predetermined shape or shape. dimensions cannot be achieved. In addition, when a large amount of metal hydroxide is contained as a flame retardant, the mechanical properties, particularly the mechanical strength, of the coating layer formed from the non-halogen flame retardant resin composition decreases, making it impossible to satisfy the required properties of the wiring material. As described above, there is a trade-off relationship between the moldability and mechanical properties of a non-halogen-based flame-retardant resin composition and the flame retardancy of a molded article thereof, and it is desired to achieve both. Moreover, in recent years, wiring materials have been required to have higher flame retardancy than before in order to improve their fire resistance and spread resistance to prevent loss of equipment due to fire and the like.
However, in Patent Documents 1 to 4, no study is conducted from this viewpoint. In particular, although Patent Document 3 mentions char formation, the char strength is merely evaluated by tapping the char after combustion with a spatula. This evaluation is subjective in terms of tapping strength, number of times or location, spatula shape, etc., and it is important to realize high flame retardancy while maintaining moldability and mechanical properties of the non-halogen flame retardant resin composition. Not evaluated in any way.

An object of the present invention is to provide a halogen-free flame-retardant resin composition that can be molded into a molded article that has excellent mechanical properties and exhibits a high degree of flame retardancy without applying an excessive load. Another object of the present invention is to provide a wiring material having a coating layer formed using the non-halogen flame retardant resin composition and exhibiting high flame retardancy and excellent mechanical properties.

The present inventors have conducted extensive studies on non-halogen flame retardant resin compositions and have found that it is not possible to form the composition by simply setting the type (combination) and content of non-halogen flame retardants and metal hydrates such as metal hydroxides. It was concluded that it is not possible to achieve a good balance between physical properties, mechanical properties, and flame retardancy. Therefore, after further investigation, we found that by using a non-halogen flame retardant consisting of clay minerals and quaternary ammonium salts in combination with metal hydrates, ethylene vinyl acetate with a specific melt flow rate (MFR) was used. The idea was that by mixing it with a base resin containing a polymer or the like, it would be possible to achieve both moldability, mechanical properties, and flame retardancy. Based on this idea, as a result of further studies, we found that a metal hydrate, the above-mentioned non-halogen flame retardant, and a base resin of ethylene-vinyl acetate copolymer or ethylene-(meth)alkyl acrylate copolymer and acid By containing modified polyolefin polymers in specific proportions and satisfying [A] (single-strip combustion test) and [B] (strength characteristics of char formed after the one-strip combustion test) described below, high moldability can be achieved. It has also been found that flame retardancy can be improved to a high level while exhibiting excellent mechanical properties. As a result, a halogen-free flame retardant resin composition that exhibits a good balance of high moldability, excellent mechanical properties, and a high degree of flame retardancy can be realized, and a wiring material with excellent mechanical properties and a high degree of flame retardancy can be realized. (covering layer) can be manufactured with high productivity (while achieving high moldability without applying excessive load).
Based on this knowledge, the present inventors have conducted further research and have completed the present invention.

That is, the object of the present invention was achieved by the following means.
<1> Ethylene having a vinyl acetate content or an alkyl (meth)acrylate content of 15 to 60% by mass and a melt flow rate (measurement temperature of 190°C, load of 2.16 kg) of 2 to 15 g/10 min. The metal hydrate is added to 100 parts by mass of a base resin containing 60 to 95 mass% of vinyl acetate copolymer or ethylene-alkyl (meth)acrylate copolymer and 5 to 40 mass% of acid-modified polyolefin polymer. A non-halogen-based flame-retardant resin composition, which contains 100 to 250 parts by mass of clay minerals and 2 to 30 parts by mass of a quaternary ammonium salt in total, and satisfies [A] and [B] below.

[A] A wiring material having an outer diameter of 5 mm and having a coating layer with a thickness of 2.1 mm formed from the above-mentioned non-halogen flame-retardant resin composition on the outer peripheral surface of a copper single-core conductor with an outer diameter of 0.8 mm was prepared. In a single line combustion test specified in IEC60332-1 using wiring materials, there should be no dripping during combustion and self-extinguishing within 60 seconds [B] At the center of the flame contact part of the char formed in the single line combustion test, When a mandrel with an outer diameter of 1.2 mm is advanced to a depth of 1 mm at a speed of 1 mm/min, the char formation strength is 10 gf or more, and the average strength is 5 gf or more.

<2> The non-halogen flame-retardant resin composition according to <1>, which has a melt flow rate (measurement temperature 190° C., load 10 kg) of 0.3 to 2.5 g/10 min or less.
<3> The non-halogen flame-retardant resin composition according to <1> or <2>, wherein the base resin contains 5 to 20% by mass of an α-polyolefin polymer.
<4> The non-halogen flame-retardant resin composition according to <3>, wherein the α-olefin polymer contains at least one of polyethylene and polypropylene.
<5> Any one of <1> to <4>, wherein the acid-modified polyolefin polymer contains at least one of maleic anhydride-modified polyethylene, acrylic acid-modified polyethylene, maleic anhydride-modified polypropylene, and acrylic acid-modified polypropylene. The halogen-free flame-retardant resin composition described in .
<6> A wiring material having a coating layer on the outer peripheral surface of the conductor,
A wiring material, wherein the coating layer is formed of the halogen-free flame-retardant resin composition according to any one of the above items <1> to <5>.
<7> The wiring material according to <6>, wherein the wiring material is an insulated wire or a power cable.
<8> The wiring material according to <6> or <7>, wherein the wiring material is an optical cable.

In this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as lower and upper limits. In addition, in the present invention, when a plurality of numerical ranges are set and explained for the content of a component, physical properties, etc., the upper limit and lower limit that form the numerical range are not limited to a specific combination of upper and lower limits, The upper limit value and lower limit value of each numerical range can be appropriately combined to form a numerical range.

The halogen-free flame-retardant resin composition of the present invention provides a coating that exhibits a high degree of flame retardancy and excellent mechanical properties while achieving high moldability that enables smooth molding without applying excessive load. A layer (molded body) can be formed. Further, the wiring material of the present invention includes a coating layer that exhibits a high degree of flame retardancy and excellent mechanical properties using the above-mentioned non-halogen flame-retardant resin composition.

FIG. 1 is a sectional view showing the structure of one embodiment of the optical cable of the present invention. FIG. 2 is a sectional view showing the structure of another embodiment of the optical cable of the present invention.

[Non-halogen flame retardant resin composition]
The non-halogen flame-retardant resin composition of the present invention has a vinyl acetate content or an alkyl (meth)acrylate content of 15 to 60% by mass, and an MFR (measurement temperature of 190°C, load of 2.16 kg) of 2. Base resin 100 containing 60-95% by mass of ethylene-vinyl acetate copolymer or ethylene-alkyl (meth)acrylate copolymer and 5-40% by mass of acid-modified polyolefin polymer with a rate of ~15g/10min parts by mass, 100 to 250 parts by mass of a metal hydrate, and 2 to 30 parts by mass of a clay mineral and a quaternary ammonium salt (in total). In addition, the halogen-free flame-retardant resin composition of the present invention satisfies the following [A] and [B]. Note that details of [A] and [B] below will be described later.

[A] A wiring material having an outer diameter of 5 mm and having a coating layer with a thickness of 2.1 mm formed of a non-halogen flame-retardant resin composition on the outer peripheral surface of a copper single-core conductor with an outer diameter of 0.8 mm was prepared, and this wiring In the single-line combustion test specified in IEC60332-1 using char, the material must self-extinguish within 60 seconds without dripping during combustion. When a 1.2 mm mandrel is advanced to a depth of 1 mm at a speed of 1 mm/min, the char formation strength is 10 gf or more, and the average strength is 5 gf or more.

By having the above composition and satisfying [A] and [B] above, each of the above components contained in a specific ratio (content) synergistically performs each function, preferably achieving an MFR within the range described below. At the same time, when the non-halogen-based flame-retardant resin composition burns, it forms a strong char, preventing the non-halogen-based flame-retardant resin composition and char from dripping (dripping), and also forming a coating material for wiring materials ( For example, it can also prevent the combustion of conductor insulation materials and fiber core coating materials, thereby preventing further spread of fire (exhibits high flame retardancy). As a result, the halogen-free flame-retardant resin composition exhibits excellent moldability, high flame retardancy, and excellent mechanical properties (particularly high mechanical strength) in a well-balanced manner. In addition, since the non-halogen flame retardant resin composition of the present invention does not contain a halogen flame retardant or a flame retardant aid, it is possible to suppress the generation of smoke and toxic gases derived from these.
Therefore, when the non-halogen flame-retardant resin composition of the present invention is used, it is possible to have a coating layer that exhibits high flame retardancy due to the formation of strong char and excellent mechanical properties (especially high mechanical strength). It is possible to manufacture a wiring material (coating layer) with high productivity (while achieving high moldability that enables smooth molding without applying excessive load). As described above, the halogen-free flame-retardant resin composition of the present invention is suitable as a composition for (extrusion) molding, and is further suitable as a coating layer forming material for wiring materials (extrusion coating layer forming material).

The halogen-free resin composition of the present invention exhibits high moldability, and preferably has an MFR (measurement temperature of 190° C., load of 10 kg) of 0.3 to 2.5 g/10 min, for example. The MFR (measurement temperature: 190°C, load: 10 kg) of the non-halogen resin composition of the present invention is more preferably 0.35 g/10 min or more, and 0.40 g/10 min or more, from the viewpoint of exhibiting even higher moldability. It is more preferable that On the other hand, the upper limit of MFR is more preferably 1.5 g/10 min or less in order to suppress the deterioration of flame retardance (particularly by preventing sag in flame retardancy tests), and to achieve high flame retardancy. It is more preferable that it is 1.0 g/10 min or less in terms of maintainability.
The MFR of a non-halogen resin composition depends on the components contained in the non-halogen resin composition, especially the base resin, the type and content of metal hydrate, and the type and content of lubricant components, clay minerals, and quaternary ammonium salts. etc., it can be adjusted as appropriate. For example, if the content of ethylene-vinyl acetate copolymer or ethylene-alkyl (meth)acrylate copolymer in the base resin is increased, the MFR of these copolymers will be increased, and the copolymer will exhibit even higher MFR. By increasing the content of , the MFR of the halogen-free resin composition can be increased.
In the present invention, the MFR of the copolymer or resin composition is the value measured based on the method specified in Japanese Industrial Standards (JIS) K 7210-1 at a measurement temperature of 190°C and a load of 10 kg or 2.16 kg. do.

Each component and content used in the present invention will be explained below.
<Base resin>
The base resin of the non-halogenated flame-retardant resin composition of the present invention or its molded product is an ethylene-vinyl acetate copolymer or Contains 60 to 95% by mass of an ethylene-alkyl (meth)acrylate copolymer and 5 to 40% by mass of an acid-modified polyolefin polymer.

(Ethylene vinyl acetate copolymer)
The ethylene-vinyl acetate copolymer may be a copolymer of ethylene and vinyl acetate (usually a resin), or may be an alternating copolymer obtained by alternately polymerizing an ethylene component and a vinyl acetate component. , a block copolymer formed by combining a polymer block of an ethylene component and a polymer block of a vinyl acetate component, or a random copolymer in which an ethylene component and a vinyl acetate component are randomly polymerized.

As the ethylene vinyl acetate copolymer, a copolymer having an MFR (measurement temperature: 190° C., weight: 2.16 kg) of 2 to 15 g/10 min according to the above measurement method is used. Thereby, the MFR of the halogen-free flame-retardant resin composition can be adjusted to the above range, contributing to the realization of excellent moldability. The MFR of the ethylene vinyl acetate copolymer is preferably from 3 to 10 g/10 min, more preferably from 4 to 10 g/10 min, from the standpoint of achieving a good balance of moldability, flame retardance, and mechanical properties.
By containing ethylene vinyl acetate copolymer as a base resin in the non-halogenated flame retardant resin composition having the above composition at a specific content described below, the MFR of the composition can be reduced even if it contains metal hydrate. Not only can moldability be improved by increasing the size, but also flame retardancy and mechanical properties can be improved.

The vinyl acetate content (also referred to as VA amount) of the ethylene vinyl acetate copolymer is 15 to 60% by mass in the ethylene vinyl acetate copolymer. When the VA amount is within this range, moldability, flame retardance, and mechanical properties can be improved. The amount of VA is preferably 20 to 35% by mass, more preferably 25 to 30% by mass, from the viewpoint of achieving a high level of moldability, flame retardance, and mechanical properties in a well-balanced manner. The vinyl acetate content in the ethylene vinyl acetate copolymer can be determined in accordance with JIS K 7192.

The number of ethylene vinyl acetate copolymers contained as the base resin may be one, or two or more.
When the non-halogenated flame retardant resin composition (base resin) of the present invention contains two or more types of ethylene vinyl acetate copolymers, all the ethylene vinyl acetate copolymers have an MFR within the above range, or even within the above range. Although it is preferable to satisfy the VA amount, it may contain an ethylene vinyl acetate copolymer that does not satisfy the MFR or VA amount. In this case, it is preferable that the ethylene vinyl acetate copolymer as a whole satisfies the MFR within the above range and further the VA amount within the above range.

The content of the ethylene vinyl acetate copolymer is 60 to 95% by mass in 100% by mass of the base resin, and it is 65% by mass in that it can achieve both flame retardancy and mechanical properties at a high level while maintaining moldability. It is preferably from 90% by mass, more preferably from 75 to 85% by mass.

(Ethylene-(meth)alkyl acrylate copolymer)
The ethylene-alkyl (meth)acrylate copolymer may be a copolymer (usually a resin) of ethylene and alkyl (meth)acrylate ester, and the ethylene component and the alkyl (meth)acrylate component are alternately polymerized. Alternatively, it may be a block copolymer formed by combining a polymer block of an ethylene component and a polymer block of an alkyl (meth)acrylate component, and further, a block copolymer consisting of a polymer block of an ethylene component and a polymer block of an alkyl (meth)acrylate component. A random copolymer in which acid alkyl components are randomly polymerized may also be used.

The alkyl group of the alkyl (meth)acrylate forming the ethylene-alkyl (meth)acrylate copolymer preferably has 1 to 12 carbon atoms. The alkyl (meth)acrylate is not particularly limited, but includes, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, Examples include 2-ethylhexyl (meth)acrylate. Examples of the ethylene-alkyl (meth)acrylate copolymer include ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-butyl acrylate copolymer (EBA). ), with ethylene-ethyl acrylate copolymer being more preferred.

As the ethylene-alkyl (meth)acrylate copolymer, a copolymer having an MFR (measurement temperature: 190° C., weight: 2.16 kg) of 2 to 15 g/10 min according to the above measurement method is used. Thereby, the MFR of the halogen-free flame-retardant resin composition can be adjusted to the above range, contributing to the realization of excellent moldability. The MFR of the ethylene-alkyl (meth)acrylate copolymer is preferably 3 to 10 g/10 min, and 4 to 10 g/10 min, in terms of achieving a good balance of moldability, flame retardance, and mechanical properties. It is more preferable.
By containing an ethylene-alkyl (meth)acrylate copolymer as a base resin in a non-halogen flame-retardant resin composition having the above composition in a specific content described below, even if metal hydrates are contained. The moldability can be improved by increasing the MFR of the composition, and the flame retardance and mechanical properties can also be improved.

The alkyl (meth)acrylate content (also referred to as AM amount, and the ethyl acrylate content is particularly referred to as EA amount) of the ethylene-alkyl (meth)acrylate copolymer is During coalescence, it is 15 to 60% by mass. When the amount of AM is within this range, moldability, flame retardance, and mechanical properties can be improved. The amount of AM is preferably 15 to 35% by mass, more preferably 15 to 30% by mass, from the standpoint of achieving high levels of moldability, flame retardance, and mechanical properties in a well-balanced manner. The alkyl (meth)acrylate content in the ethylene-alkyl (meth)acrylate copolymer can be determined by using an infrared spectrometer and using the ratio of the absorbance due to carbonyl of the acrylic ester moiety to the absorbance due to methylene. can be determined.

The base resin may contain one type of alkyl ethylene (meth)acrylate, or two or more types.
When the halogen-free flame-retardant resin composition (base resin) of the present invention contains two or more types of ethylene-alkyl (meth)acrylate copolymers, all of the ethylene-alkyl (meth)acrylate copolymers are Although it is preferable to satisfy the MFR within the above range and further the AM amount within the above range, it may contain an ethylene-alkyl (meth)acrylate copolymer that does not satisfy the MFR or the AM amount. In this case, it is preferable that the ethylene-alkyl (meth)acrylate copolymer as a whole satisfies the MFR within the above range and further the AM amount within the above range.

The content of the ethylene-alkyl (meth)acrylate copolymer is 60 to 95% by mass in 100% by mass of the base resin, achieving a high level of flame retardancy and mechanical properties while maintaining moldability. The content is preferably 65 to 90% by mass, more preferably 75 to 85% by mass.

(Acid-modified polyolefin polymer)
As the acid-modified polyolefin polymer, a polymer (usually a resin) obtained by modifying the polyolefin polymer described below with an unsaturated carboxylic acid compound (also simply referred to as unsaturated carboxylic acid) or its anhydride can be suitably used. can.
By incorporating an acid-modified polyolefin polymer as a base resin into the non-halogenated flame-retardant resin composition having the above composition, the dispersibility of clay minerals is increased, resulting in excellent moldability and flame retardancy. Mechanical properties, especially mechanical strength, can be strengthened while maintaining properties.

The polyolefin polymer to be acid-modified is not particularly limited as long as it is an α-olefin polymer, and includes, for example, the α-olefin polymer described below, and polyethylene or polypropylene is preferable from the viewpoint of strengthening mechanical properties. The polyolefin polymer forming the acid-modified polyolefin resin may be one type or two or more types.
The unsaturated carboxylic acid (including anhydride) that forms the acid-modified polyolefin resin is not particularly limited, and carboxylic acids having an unsaturated bond that can react with the polyolefin polymer (for example, radical addition reaction) are preferably used. Can be mentioned. This unsaturated carboxylic acid may have one carboxy group or two or more carboxy groups. Preferred unsaturated carboxylic acids include, for example, acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, metal salts or organic salts thereof, and furthermore maleic anhydride and itaconic anhydride. , unsaturated carboxylic acid anhydrides such as fumaric anhydride, and the like. These unsaturated carboxylic acids may be used alone or in combination of two or more.
Acid-modified polyolefin polymers have groups derived from unsaturated carboxylic acids, usually as side chains (pendant chains, graft chains, etc.), by reacting the unsaturated groups of unsaturated carboxylic acids with the above polyolefin polymers. .

From the viewpoint of affinity with clay minerals, the acid-modified polyolefin polymer is preferably at least one of polyethylene and polypropylene modified with maleic anhydride or acrylic acid. That is, the non-halogenated flame retardant resin composition of the present invention contains at least one of maleic anhydride-modified polyethylene, acrylic acid-modified polyethylene, maleic anhydride-modified polypropylene, and acrylic acid-modified polypropylene as the acid-modified polyolefin polymer. is preferred. Among these, maleic anhydride-modified polyethylene is preferred because it has a high effect of improving mechanical properties (mechanical strength).
The amount of modification by unsaturated carboxylic acid in the acid-modified polyolefin polymer is not particularly limited, but is preferably 0.1 to 2.0% by mass, and 0.2 to 1.0% by mass, based on the polyolefin polymer (before modification). 0% by mass is more preferred.

The acid-modified polyolefin polymer may be synthesized as appropriate, or a commercially available product may be used. When synthesizing an acid-modified polyolefin polymer, the polyolefin polymer is usually synthesized by heating and mixing a polyolefin polymer and an unsaturated carboxylic acid in the presence of an organic peroxide at a temperature higher than the decomposition temperature of the organic peroxide. can be obtained by modifying (reacting with an unsaturated carboxylic acid).

The number of acid-modified polyolefin polymers contained as the base resin may be one type, and two or more types may be used.
The content of the acid-modified polyolefin polymer is 5 to 40% by mass in 100% by mass of the base resin, and it is effective in improving mechanical properties, especially mechanical strength, while maintaining moldability and flame retardancy. , is preferably 5 to 35% by mass, more preferably 8 to 30% by mass, even more preferably 10 to 25% by mass, and the upper limit is set to 18% by mass or 12% by mass. You can also. In the present invention, the content of the acid-modified polyolefin polymer can be set high, and the content of the acid-modified polyolefin polymer in this embodiment can be, for example, 20% by mass or more, and 25% by mass or more. It is preferable that

(α-olefin polymer)
The base resin can contain an alpha olefin polymer.
An α-olefin polymer is a polymer (usually a resin) obtained by homopolymerizing or copolymerizing an α-olefin compound having an ethylenically unsaturated bond at the end (usually an alkene having an ethylenically unsaturated bond at the end). There are no particular limitations, and conventionally known polymers can be used as long as they are not acid-modified. In the present invention, "not acid-modified" refers to an embodiment in which the amount of modification of the α-olefin polymer is 0% by mass, as well as an embodiment in which the amount of modification of the α-olefin polymer is 0% by mass, as well as an amount that is distinguishable from the acid-modified polyolefin polymer (for example, the amount of modification is 0.1%). % by mass) is included.
Examples of the α-olefin polymer preferably used in the present invention include resins such as polyethylene, polypropylene, and copolymers having an acid copolymerization component.

The number of α-olefin polymers contained as the base resin may be one, and two or more types may be used.
The total content of α-olefin polymers is preferably 20% by mass or less in 100% by mass of the base resin, and is 5 to 20% by mass in terms of widening the temperature range at which good surface properties of the molded product can be obtained. It is more preferable that the amount is 5 to 15% by mass, and in consideration of the influence on combustion characteristics, it is even more preferable that the amount is 5 to 15% by mass.

- Polyethylene -
Polyethylene (PE) is not particularly limited as long as it is a polymer (usually a resin) whose main component is ethylene. For example, ethylene homopolymers, high-density polyethylene (HDPE), low-density polyethylene (LDPE), ultra-high molecular weight polyethylene (UHMW-PE), linear low-density polyethylene (LLDPE), and very low-density polyethylene (VLDPE) Each resin can be mentioned.
One type of polyethylene may be contained as the base resin, and two or more types may be used.
The content of polyethylene is appropriately determined in consideration of the above-mentioned total content of α-olefin polymers. For example, it is preferably 0 to 15% by mass, more preferably 5 to 15% by mass based on 100% by mass of the base resin, since the extrusion temperature range can be particularly widened without adversely affecting flammability. It is preferably 8 to 10% by mass, and more preferably 8 to 10% by mass.

- Polypropylene -
Polypropylene may be any polymer (usually a resin) containing a propylene component as a main component, and examples thereof include a propylene homopolymer (homopolypropylene), random polypropylene, and block polypropylene. As the polypropylene, random polypropylene is preferable from the viewpoint of extrusion surface properties.
The number of types of polypropylene contained as the base resin may be one, and two or more types may be used.
The content of polypropylene is appropriately determined in consideration of the above-mentioned total content of α-olefin polymers. For example, it is preferably 0 to 15% by mass, more preferably 2 to 12% by mass, based on 100% by mass of the base resin, since the extrusion surface properties can be improved without adversely affecting flammability. , more preferably 3 to 10% by mass.

- Polyolefin copolymer with acid copolymerization component -
The acid copolymerization component constituting the polyolefin copolymer having an acid copolymerization component is incorporated into the main chain, and in this point, it differs from the above-mentioned acid-modified polyolefin polymer. The acid copolymerization component is not particularly limited, but includes carboxylic acid compounds such as (meth)acrylic acid. Examples of the polyolefin copolymer having an acid copolymerization component include ethylene-(meth)acrylic acid copolymer.
The number of polyolefin copolymer resins having an acid copolymerization component contained as the base resin may be one type, and two or more types may be used.
The content of the polyolefin copolymer having an acid copolymerization component is appropriately determined in consideration of the above-mentioned total content of the α-olefin polymer. For example, in 100% by mass of the base resin, it can be 20% by mass or less, and preferably 0 to 10% by mass.

<Metal hydrate>
The non-halogen flame retardant resin composition of the present invention contains a metal hydrate.
As the metal hydrate, those commonly used as fillers in resin compositions can be used without particular limitation.
Examples of such metal hydrates include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whiskers, Examples include metal hydrates such as hydrated aluminum silicate, hydrated magnesium silicate, basic magnesium carbonate, hydrotalcite, talc, and other compounds having hydroxyl groups or water of crystallization. In addition, boron nitride, silica (crystalline silica, amorphous silica, etc.), carbon, zinc oxide, tin oxide, titanium oxide, molybdenum oxide, antimony trioxide, quartz, white carbon, zinc hydroxystannate, zinc stannate, etc. can also be mentioned.

As the metal hydrate, a metal hydrate surface-treated with a silane coupling agent, a fatty acid such as stearic acid, etc. can be used. Examples include Kisuma 5L, Kisuma 5P (all brand names, magnesium hydroxide, manufactured by Kyowa Chemical Industry Co., Ltd., etc.), and BF013S (trade names, magnesium hydroxide, manufactured by Nippon Light Metal Co., Ltd.). The amount of surface treatment of the metal hydrate with a silane coupling agent or the like is not particularly limited, but is preferably, for example, 3% by mass or less.
Metal hydrates are usually contained in the form of powder or particles. The average particle diameter at this time is not particularly limited, but is preferably 0.2 to 10 μm. When the average particle size is within the above range, secondary aggregation can be suppressed. The average particle size is determined by dispersing the inorganic filler in alcohol or water and using an optical particle size measuring device such as a laser diffraction/scattering type particle size distribution measuring device.

Among the metal hydrates mentioned above, metal hydroxides such as aluminum hydroxide and magnesium hydroxide are preferred, and magnesium hydroxide is preferred because it has a high ability to form a shell during combustion and exhibits high flame retardancy. preferable. On the other hand, the present invention achieves high flame retardancy while maintaining moldability and mechanical properties by using a metal hydrate in combination with a flame retardant aid containing a clay mineral and a quaternary ammonium salt, which will be described later, and a specific base resin. Make gender reality possible. Therefore, even if it contains aluminum hydroxide, which has a shell-forming ability inferior to magnesium hydroxide as a metal hydrate, the low shell-forming ability can be reinforced and the desired high flame retardance can be achieved. . That is, according to the present invention, the flame retardance, which tends to deteriorate when aluminum hydroxide having poor shell-forming ability is used, can be improved, and a high flame retardant improvement effect can be exhibited. In this respect, in the present invention, aluminum hydroxide, which is inexpensive and has high versatility, can be preferably used as the metal hydrate.

The halogen-free flame-retardant resin composition of the present invention may contain one or more metal hydrates.
The content of the metal hydrate in the non-halogen flame retardant resin composition is 100 to 250 parts by mass based on 100 parts by mass of the base rubber. Within this range, deterioration in mechanical properties due to the inclusion of metal hydrates can be suppressed. The lower limit of the content is preferably 120% by mass or more, more preferably 140% by mass or more, and 160% by mass in order to achieve high flame retardancy while maintaining mechanical properties and moldability. It is more preferable that it is above. On the other hand, the upper limit is preferably 220% by mass or less, and more preferably 200% by mass or less, from the viewpoint of suppressing the decrease in MFR of the composition and deterioration of moldability.

<Clay minerals and quaternary ammonium salts>
The non-halogen flame retardant resin composition of the present invention contains a clay mineral and a quaternary ammonium salt. The clay mineral and the quaternary ammonium salt coexisting with each other work together with the base resin and the metal hydrate to improve the flame retardancy of the non-halogen flame retardant resin composition. In particular, even if a high content of the above-mentioned ethylene vinyl acetate copolymer or ethylene-alkyl (meth)acrylate copolymer is used as the base resin, the non-halogen flame-retardant resin composition due to the inclusion of these copolymers It is possible to maintain excellent flame retardancy by reinforcing the decrease in flame retardancy (deterioration in shell-forming ability). Furthermore, it becomes possible to improve mechanical properties.
The form in which clay minerals and quaternary ammonium salts are contained or present in the non-halogen flame-retardant resin composition and their molded articles (coating layer) is not particularly limited, and for example, each may be contained or present alone. Examples include a form, a form in which the substance is contained or exists as a mixture or a complex, and a form in which these forms coexist. Here, the mixture or complex refers to one formed of a clay mineral and a quaternary ammonium salt, and may also be formed of a clay mineral and ions constituting the quaternary ammonium salt. Examples of such mixtures and composites include those obtained by treating clay minerals with quaternary ammonium salts under normal conditions. ), RXG7581 (product name, manufactured by BYK, bentonite treated with dialkyl dimethyl ammonium salt (CAS.61789-80-8)), Kunipia F, Kunipia G, Kunipia G4, Kunipia G10 (all product names, (manufactured by Kunimine Kogyo Co., Ltd.), etc.

The clay mineral and quaternary ammonium salt (mixture, composite, etc.) contained in the halogen-free flame-retardant resin composition of the present invention may be one type or two or more types.
The total content of the clay mineral and the quaternary ammonium salt in the non-halogen flame retardant resin composition is 2 to 30 parts by mass based on 100 parts by mass of the base rubber. Thereby, in cooperation with a specific amount of base resin and metal hydrate, a particularly strong char can be formed, and moldability, high flame retardance, and mechanical properties can be achieved. The lower limit of the total content is preferably 8% by mass or more, more preferably 10% by mass or more, in order to achieve a high degree of flame retardancy while maintaining mechanical properties and moldability. More preferably, the content is 12% by mass or more. On the other hand, the upper limit is preferably 20% by mass or less, more preferably 18% by mass or less, from the viewpoint of suppressing deterioration of moldability while maintaining high flame retardancy and excellent mechanical properties. , more preferably 15% by mass or less.
The content ratio of clay mineral and quaternary ammonium salt (clay mineral:quaternary ammonium salt, mass ratio) is not particularly limited, but is preferably 90:10 to 60:40, for example.

(clay mineral)
Clay minerals work together with metal hydrates and the like to contribute to improving the flame retardancy of the halogen-free flame retardant resin composition. As the clay mineral, those commonly used in resin compositions can be used without particular limitation. Clay minerals containing silicate minerals as a main component are preferred, and clay minerals containing silicate minerals having a layered crystal structure are more preferred. When the clay mineral is a layered compound, the layered structure (laminated state) of the clay mineral may be collapsed and the constituent layer may exist alone in the non-halogen flame retardant resin composition and its molded product. Specific examples of clay minerals include kaolin minerals (kaolinite, nacrite, daykite, halloysite), mica clay minerals, smectite (montmorillonite, beidellite, saponite, hectorite, etc.), mixed layer minerals, and the like.
The silicate mineral preferably contains cations, and preferably has cations between layers. Cations typically include metal cations such as Ca ⁺ , Na ⁺ , and K ⁺ .
The clay mineral may be a natural product or a synthetic product by hydrothermal synthesis, melting method, solid phase method, etc. As the clay mineral, it is also possible to use a commercially available substance (for example, a composite) in which a part of the cations of the silicate contained therein are replaced by quaternary ammonium cations derived from a quaternary ammonium salt described below. The clay mineral may be contained in clay. Examples of the clay include acid clay containing a large amount of montmorillonite, bentonite, and kaolin containing a large amount of kaolin mineral, with bentonite being preferred.
The halogen-free flame-retardant resin composition of the present invention may contain one or more clay minerals.
The content of the clay mineral in the halogen-free flame retardant resin composition is appropriately determined in consideration of the above-mentioned total content. For example, the amount may be 1 to 20 parts by mass based on 100 parts by mass of the base rubber.

(Quaternary ammonium salt)
The quaternary ammonium salt serves to enhance the dispersibility of clay minerals in the base resin. From the viewpoint of further improving the dispersibility of the clay mineral, it is preferable to use the clay mineral and the quaternary ammonium salt as a mixture or a composite in which they are mixed in advance.
The quaternary ammonium salt is not particularly limited, and includes, for example, those represented by NR ₄ ⁺ X ⁻ . In the formula, R each independently represents a hydrogen atom, an alkyl group, a hydroxyalkyl group (-R ¹ OH, R ¹ represents an alkylene group), -(R ² O) _n H (R ² represents an alkylene group). and n is an integer from 1 to 20), or an aryl group. However, at least one R among the four R's is an alkyl group, a hydroxyalkyl group, -(R ² O) _n H, or an aryl group, and an alkyl group is preferable. The alkyl group that can be used as R is not particularly limited, but an alkyl group having 1 to 20 carbon atoms is preferable. The alkylene group that can be used as R ¹ or R ² is not particularly limited, but is preferably an ethylene group. Multiple R's in a single molecule may be the same or different. n is preferably an integer of 1 to 20, more preferably an integer of 1 to 10, even more preferably an integer of 1 to 5, and particularly preferably 1. X ⁻ represents a counter ion. X ^- is not particularly limited and various anions are appropriately selected, but halogen ions are preferred, such as Cl ^- , Br ^-, and the like.
The halogen-free flame-retardant resin composition of the present invention may contain one or more quaternary ammonium salts.
The content of the quaternary ammonium salt in the halogen-free flame-retardant resin composition is appropriately determined in consideration of the above-mentioned total content. For example, the amount may be 0.2 to 12 parts by mass based on 100 parts by mass of the base rubber.

<Other polymers>
The non-halogen flame retardant resin composition of the present invention may contain a polymer (resin, elastomer, rubber, etc.) other than the polymer constituting the base resin. Examples include styrene elastomer, acrylic rubber, ethylene propylene rubber, and the like. The content of other polymers is appropriately determined within a range that does not impair the effects of the present invention, and can be, for example, 30% by mass or less based on 100% by mass of the base resin.

<Other additives>
The halogen-free flame-retardant resin composition of the present invention can contain various additives commonly used in resin compositions within a range that does not impair the object of the present invention. Examples of additives include flame retardant aids, antioxidants (antioxidants), lubricants, dispersants, crosslinking agents, crosslinking aids, colorants, and the like.
Each additive that may be contained in the non-halogen flame retardant resin composition may be one type or two or more types.

(Flame retardant aid)
Flame retardant aids include, but are not particularly limited to, triazine derivatives, zinc sulfide, zinc borate, and the like. Triazine derivatives can contribute to the formation of a strong char and further improve flame retardancy. Examples of the triazine derivative include melamine, cyanuric acid, isocyanuric acid, melamine cyanurate, and melamine isocyanurate, with melamine cyanurate and melamine isocyanurate being preferred. As the flame retardant aid, it is preferable to use melamine cyanurate and zinc sulfide in combination.
The (total) content of the flame retardant aid in the non-halogenated flame retardant resin composition is set within a range that does not impair the effects of the present invention, and is, for example, 5 to 100 parts by mass based on 100 parts by mass of the base resin. It can be done. In particular, the content of the triazine derivative can be 5 to 50 parts by weight based on 100 parts by weight of the base resin, and the content of zinc sulfide can be 1 to 10 parts by weight based on 100 parts by weight of the base resin. can. In the present invention, zinc borate may be contained, but it is preferably not contained. Not containing zinc borate includes an embodiment in which the content in the non-halogen flame retardant resin composition is 0 parts by mass based on 100 parts by mass of the base resin, as well as an embodiment in which the content is less than 5 parts by mass. .

(Anti-aging agent)
Antioxidants include, but are not particularly limited to, amine antioxidants, phenol antioxidants, sulfur antioxidants, and the like, with phenol antioxidants being preferred. The content of the anti-aging agent in the non-halogenated flame-retardant resin composition is set within a range that does not impair the effects of the present invention, for example, 0.2 to 10 parts by mass based on 100 parts by mass of the base resin. be able to.

(Lubricant)
Examples of the lubricant include, but are not limited to, silicone compounds, fatty acids, fatty acid metal salts, fatty acid amides, and the like, with silicone compounds being preferred. The content of the lubricant in the non-halogen flame-retardant resin composition is set within a range that does not impair the effects of the present invention, and may be, for example, 0.5 to 10 parts by mass based on 100 parts by mass of the base resin. can.

(dispersant)
By uniformly dispersing the metal hydrate in the non-halogen flame retardant resin composition (base resin), the dispersant can contribute to the formation of a strong char and further improve the flame retardance. Such a dispersant is not particularly limited, and any appropriate dispersant can be used. For example, various compounds such as fatty acid ester, organic modified siloxane, alkyl/ester modified siloxane, hydrophobic nonionic polyester siloxane, etc. fatty acid esters are preferred. Commercially available dispersants include BYK-MAX P4102 (trade name, fatty acid ester, manufactured by BYK) and TEGOMER V-Si 4042 (trade name, organically modified siloxane, manufactured by Evonik) in terms of further improving flame retardancy. ), Tegoprene 6875 (trade name, alkyl/ester modified siloxane, manufactured by Evonik), Tegoma FR100 (trade name, organic modified siloxane, manufactured by Evoik), Tegoprene 5885 (trade name, hydrophobic nonionic polyester siloxane, manufactured by Evonik) company), etc. The content of the dispersant in the non-halogenated flame-retardant resin composition can be, for example, 1 to 10 parts by mass, based on 100 parts by mass of the base resin, from the viewpoint of improving flame retardance, and 1 The amount is preferably 4 parts by mass.

<Crosslinking agent and crosslinking aid>
When the halogen-free flame-retardant resin composition of the present invention is a crosslinkable composition, it may contain an appropriate crosslinking agent and further a crosslinking aid depending on the crosslinking method. The crosslinking method applicable to the halogen-free flame-retardant resin composition of the present invention is not particularly limited, but electron beam crosslinking and chemical crosslinking are preferred. Examples of chemical crosslinking methods include phenol crosslinking, amine crosslinking, silane crosslinking, and peroxide crosslinking. Known crosslinking agents and crosslinking aids used in each crosslinking method can be used without particular restriction.

<Physical properties or characteristics>
The halogen-free flame-retardant resin composition of the present invention may be a crosslinked resin composition or a non-crosslinked resin composition, and is appropriately selected depending on the intended use and required characteristics. When used as a coating material for wiring materials, especially optical cables, it is preferably a non-crosslinked resin composition.
(Moldability)
The halogen-free flame-retardant resin composition of the present invention having the above composition exhibits high moldability, and preferably exhibits the above-mentioned MFR. Therefore, when molding is performed using the non-halogen flame retardant resin composition of the present invention, smooth molding is possible with a load within the allowable range of the molding machine without placing an excessive load on the molding machine. Further, by taking advantage of the high moldability, a molded body (coating layer) can be formed, preferably a molded body having a predetermined shape and size.

(Flame retardance)
The halogen-free flame-retardant resin composition of the present invention and molded articles thereof exhibit high flame retardancy.
- Single line combustion test -
For example, the non-halogen flame retardant resin composition of the present invention (including a molded article) is a layer formed with the non-halogen flame retardant resin composition of the present invention on the outer circumferential surface of a copper single-core conductor having an outer diameter of 0.8 mm. When a wiring material test piece with an outer diameter of 5 mm and a coating layer with a thickness of 2.1 mm was prepared, there was no dripping during combustion in a single line combustion test specified in IEC60332-1 using this wiring material test piece. It exhibits high flame retardancy [A] with an extinguishing time of 60 seconds or less (self-extinguishing within 60 seconds). The halogen-free flame-retardant resin composition of the present invention has even higher flame retardancy in this flame retardancy [A], with a flame extinguishing time of within 30 seconds, further within 20 seconds, and especially within just 15 seconds. Contains forms that can be achieved.

- Char strength -
The halogen-free flame-retardant resin composition of the present invention has a strong char (combustion residue ) can be formed. In other words, char has a formation strength (maximum value) of 10 gf or more when a mandrel with an outer diameter of 1.2 mm is entered perpendicularly to the conductor to a depth of 1 mm at a speed of 1 mm/min into the center of the flame contact area. and exhibits high strength with an average strength of 5 gf or more (char strength [B]). Therefore, even if a wiring material having a coating layer formed from the non-halogenated flame-retardant resin composition of the present invention is burned in a fire or the like, a high-strength char can be formed. Even if the char formed in this way is exposed to flame or heat for a long time, it will not drip or fall off from the insulation material of the conductor or the coating material of the fiber core, and the dripping char will prevent the spread of fire and even the conductor. It also exhibits a barrier effect that prevents the exposure of fibers, etc., and prevents further combustion of the conductor insulation material and the fiber core coating material, etc., and exhibits high flame retardancy.
Here, the forming strength (maximum value) is determined by using an autograph device: AGS-J5KN (manufactured by Shimadzu Corporation) with a mandrel with an outer diameter of 1.2 mm at a speed of 1 mm/min perpendicular to the conductor to a depth of 1 mm. This refers to the highest value of the intensity values measured during entry. In addition, the average strength is the arithmetic average of the strength values measured when a mandrel with an outer diameter of 1.2 mm is advanced perpendicularly to the conductor to a depth of 1 mm at a speed of 1 mm/min using the above autograph device. refers to value.

In the present invention, the forming strength (maximum value) is preferably 20 gf or more, more preferably 25 gf or more, and even more preferably 30 gf or more, since flame retardancy can be further improved. The upper limit of the forming strength (maximum value) is not particularly limited, but 45 gf is practical, and can be set to 40 gf or less, for example.
In the present invention, the average strength is preferably 10 gf or more, more preferably 15 gf or more, and even more preferably 20 gf or more, since flame retardancy can be further improved. The upper limit of the average intensity is not particularly limited, but 35 gf is practical, and can be set to 30 gf or less, for example.

- Sheet flame retardancy -
The halogen-free flame-retardant resin composition of the present invention and its molded product exhibit high flame retardancy in that it self-extinguishes without dripping in the sheet flame retardancy test in Examples described below, and preferably, It is also possible to exhibit even higher flame retardancy, which self-extinguishes within 60 seconds.

(mechanical properties)
The tensile strength achieved by the halogen-free flame-retardant resin composition of the present invention and its molded product varies depending on the application and required properties, so it is not unambiguous, but for example, it is preferably 5 MPa or more, and 8 ~20 MPa is more preferable. The elongation at break is not unambiguous as it varies depending on the application, required characteristics, etc., but for example, it is preferably 150% or more, more preferably 170% or more, and the upper limit is not particularly limited, but about 270% is practical. be. In addition, 100% modulus (sometimes expressed as 100% M) is not unambiguous as it varies depending on the application and required characteristics, but for example, it is preferably 3 MPa or more, and 3 to 10 MPa is more preferable. preferable. The above tensile strength, elongation at break, and 100% modulus are values measured by the measuring method described in the examples below.

<Applications of non-halogen flame retardant resin composition>
Since the halogen-free flame-retardant resin composition of the present invention exhibits the above-mentioned excellent properties, it can be suitably used as a material for forming a wiring material, particularly a coating layer of a wiring material. It can also be applied to general molded products (sealing materials, packing, etc.). As for the molding method at this time, various known molding methods can be applied without particular limitation, but extrusion molding and injection molding are preferable, taking advantage of their excellent moldability.

<Method for preparing the non-halogen flame retardant resin composition of the present invention>
The non-halogen flame-retardant resin composition of the present invention can be prepared by melt-kneading a base resin, a metal hydrate, a clay mineral, a quaternary ammonium salt, and other additives as appropriate.
The kneading method is not particularly limited as long as it is a method normally employed for preparing rubber or resin compositions. For example, mixing can be performed using various mixing devices such as a single-screw kneader, a twin-screw kneader, a roll, a Banbury mixer, and various types of kneaders. Kneading conditions such as kneading temperature and kneading time are not particularly limited, and can be appropriately set within a temperature range equal to or higher than the melting temperature of the base resin. The kneading temperature is preferably, for example, 120 to 220°C. By melt-kneading, an uncrosslinked or non-crosslinked resin composition in which each component is uniformly dispersed (mixed) can be obtained.

In mixing the respective components, during kneading, the above-mentioned respective components can be melted and kneaded at once, or each component can be mixed one after another in an appropriate order. In the present invention, it is preferable that the clay mineral and the quaternary ammonium salt are mixed in advance to form a mixture or a composite, and then kneaded with the above-mentioned components. Commercially available mixtures or composites of quaternary ammonium salts and clay minerals may also be used. It is believed that when such a mixture or composite is kneaded with a base resin, the shearing force during kneading causes the clay minerals to deagglomerate, making it possible to obtain a resin composition in which the clay minerals are more highly dispersed.
According to a preferred preparation method, a clay mineral prepared by pre-mixing a clay mineral and a quaternary ammonium salt (treated (mixed) with a quaternary ammonium salt), a base resin and a metal hydrate are mixed in the above specific ratio. A halogen-free flame retardant resin composition of the present invention is prepared.

[Wiring material]
A wiring material using a tubular molded body formed from the non-halogen flame retardant resin composition of the present invention as a coating layer will be described below.
The wiring material of the present invention has a coating layer (including an insulating layer, a sheath, etc.) formed of the halogen-free flame-retardant resin composition of the present invention on the outer peripheral surface of the conductor. This wiring material has excellent flame retardancy and mechanical properties, as well as excellent wiring properties.
The wiring material of the present invention only needs to have at least one coating layer made of the non-halogen flame-retardant resin composition of the present invention on the outer circumferential surface of the conductor or optical fiber core, and the other structure is the wiring material. The configuration can be similar to the normal configuration of . Examples include an insulated wire having at least one coating layer on the outer circumferential surface of a conductor, a cable in which a sheath as a coating layer is formed on the outer circumferential surface of such an insulated wire or a wire bundle made by bundling a plurality of these insulated wires, etc. . Further, the coating layer made of the halogen-free flame-retardant resin composition of the present invention may be provided directly on the outer peripheral surface of the conductor, or may be provided indirectly through another layer such as an adhesive layer. The coating layer may be a single layer or a multilayer, and in the case of a multilayer, at least one layer may be formed of the halogen-free flame-retardant resin composition of the present invention. Further, the sheath of the cable may be formed from the non-halogen flame retardant resin composition of the present invention.

As the conductor, an appropriate conductor can be used depending on the wiring material. For example, a single wire conductor or a twisted wire conductor (including a twisted wire in which tensile strength fibers are longitudinally spliced or twisted together) can be used as appropriate. For example, a conductor used for an insulated wire or the like may be a bare wire or one coated with tin or enamel. Examples of the metal material forming the conductor include annealed copper, copper alloy, and aluminum. The outer diameter of the conductor, etc. is appropriately determined depending on the application, etc., and can be set in the same manner as ordinary wiring materials used for each application. For example, it can be set to 0.5 to 4.0 mm. Examples of conductors used in optical cables and the like include optical fiber cores of the optical cable 1 described later, and may be single-core or multi-core.
The thickness (thickness) of the coating layer is determined appropriately depending on the application, etc., but it can be set to the same thickness as the normal wiring material used for each application. It is set to about 0.15 to 10 mm.

Examples of the wiring material include insulated wires or cables, (electrical) cords, optical fiber cores, optical fiber cords, and optical cables. These include wiring materials used for internal wiring or external wiring of electric/electronic equipment, wiring materials installed indoors, and wiring materials installed outdoors. The wiring material of the present invention can preferably be used as an insulated wire or cable for a vehicle (automobile, railway vehicle, etc.), a communication wire or cable, a communication optical cable, or a power wire or power cable. In particular, optical cables installed in data centers and the like and used for transmitting large amounts of information are preferable.
Examples of the wiring material of the present invention include an electric wire shown in FIG. 1 of Patent Document 1 in which the insulator 3 of the electric wire is formed of the non-halogen flame-retardant resin composition of the present invention, and a wire shown in FIG. 2 of Patent Document 2. Examples of the cable include a cable in which the insulator 23 and/or the sheath 24 are made of the halogen-free flame-retardant resin composition of the present invention. In addition, the present invention also provides an optical cable in which the coating layer 20 of the optical cable shown in FIG. Examples include optical cables formed from halogen-free flame-retardant resin compositions.

An embodiment in which the wiring material is an optical cable will be described with reference to FIG. 1.
FIG. 1 shows a cross section perpendicular to the longitudinal direction of the optical cable.
The optical cable 1 shown in FIG. 1 includes an optical fiber core 10 and a coating layer (sheath) 20 formed around the optical fiber core 10 (outer peripheral surface) using the non-halogen flame retardant resin composition of the present invention. have
The optical cable 1 is not particularly limited in other forms as long as it has the above configuration, and the number of coating layers 20, the number of optical fiber cores 10, the arrangement of optical fiber cores 10, etc. may be determined as appropriate depending on the application. Can be set. When the coating layer has a multilayer structure, at least one coating layer may be formed of the halogen-free flame-retardant resin composition of the present invention. In this case, other layers, such as the intermediate layer, can be formed from a resin or a composition thereof commonly used for optical cables.
The optical cable 1 has a single optical fiber core 10, and the optical fiber core 10 can be a normal optical fiber without any particular restriction, and may be an optical fiber itself, or an optical fiber core 10. The wire may have a winding of insulating tape or a coating layer on the outer peripheral surface of the wire. When a coating layer or the like is provided on the optical fiber strand, this corresponds to the case where the coating layer has a multilayer structure in the configuration shown in FIG. 1 above. A normal optical fiber can be used as the optical fiber. The optical fiber wire is preferably a wire made of quartz fiber.
The outer diameters of the optical cable 1 and the optical fiber core wire 10 are appropriately set depending on the purpose and the like. The thickness of the coating layer, especially the coating layer 20 formed of the non-halogen flame-retardant resin composition of the present invention, is appropriately set depending on the application etc. The thickness is preferably 0.2 to 5 mm in terms of exhibiting the excellent properties possessed by.

The optical cable 1 may include a tension member (not shown in FIG. 1). As the tension member, any tension member that is normally applied to optical cables can be used without particular limitation. Further, the number and position of the tension members are not particularly limited, and may be set appropriately. For example, the tension members may be arranged so as to cover the outer periphery of the optical fiber, or may be arranged at a distance from the optical fiber. You can leave it there. Further, the optical cable 1 may be a multi-core cable having an optical fiber bundle in which a plurality of optical fibers described below are bundled instead of the optical fiber core 10.

FIG. 2 is a diagram showing a cross section perpendicular to the longitudinal direction of another embodiment of the wiring material (optical cable) of the present invention.
As shown in FIG. 1, the optical cable 2 includes an optical fiber bundle 11, a nonwoven tape 12 wound around the optical fiber bundle 11 (outer peripheral surface), and a nonwoven tape 12 wound around the nonwoven tape 12 (outer peripheral surface). It has a sheath 21 made of the non-halogen flame retardant resin composition of the present invention, and two tension members 13 embedded in the sheath 21 along the optical fiber bundle 11.
The optical cable 2 is not particularly limited in other forms as long as it has the above configuration, including the number of optical fibers constituting the optical fiber bundle 11, the presence or absence of the nonwoven tape 12, and the number and arrangement of the tension members 13. , the number of layers of the sheath 21, etc. can be set as appropriate depending on the application. When the sheath 21 has a multilayer structure, at least one layer of the sheath 21 may be formed of the halogen-free flame-retardant resin composition of the present invention. In this case, other layers, such as the intermediate layer, can be formed from a resin or a composition thereof commonly used for optical cables.
The optical cable 2 has an optical fiber bundle 11, and a normal optical fiber bundle 11 can be used without any particular restriction. The number of optical fibers constituting the optical fiber bundle 11 is usually two or more, but it is set appropriately depending on the performance and application, and in high-performance applications, for example, 288, 864, Furthermore, the number can be set to 1728. The optical fiber bundle 11 may be a bundle of a plurality of optical fibers, and may be a twisted wire or a drawn wire, and may be set as appropriate. On the other hand, the optical fiber bundle 11 can also be a single optical fiber. Each optical fiber core may be an optical fiber itself, or may have an insulating tape winding or a coating layer on the outer peripheral surface of the optical fiber. As the optical fiber strand, a normal one can be used, and for example, a quartz fiber strand is preferable.
A nonwoven tape 12 is wound around the optical fiber bundle 11 to cover the optical fiber bundle 11 all at once. Instead of the nonwoven tape 12, a commonly used material such as an insulating tape may be used as appropriate.
A single-layer sheath 21 is provided around the non-woven fabric tape 12, and two tension members 13 are installed inside the sheath 21 so that the central angle is approximately 180° (facing each other across the optical fiber bundle 11). It is buried. As the tension member 13, any material normally applied to optical cables, such as a filament made of metal, resin, etc., can be used without particular limitation.
The outer diameters of the optical cable 2, the optical fiber core bundle 11, and the tension member 13 are appropriately set depending on the application and the like. The thickness of the sheath 21, especially the sheath 21 formed of the non-halogen flame-retardant resin composition of the present invention, is set appropriately depending on the application. The thickness is preferably 0.2 to 5 mm in terms of exhibiting the excellent characteristics that it has.

<Method for manufacturing wiring materials>
The wiring material of the present invention can be manufactured by an appropriate method, but it can be manufactured by disposing the halogen-free flame-retardant resin composition of the present invention on the outer peripheral surface of a conductor and subjecting it to an appropriate crosslinking reaction treatment. is preferred.

The method of disposing the non-halogen flame retardant resin composition of the present invention on the outer peripheral surface of the conductor, optical fiber core wire, and optical fiber core bundle may be any method that allows the conductor to be coated with the non-halogen flame retardant resin composition. Often, suitable molding methods are applied. For example, the molding method includes extrusion molding using an extruder, injection molding using an injection molding machine, and molding using other molding machines. In the present invention, extrusion molding or injection molding is preferred to take advantage of high moldability, and extrusion molding in which a conductor and a non-halogen flame-retardant resin composition are co-extruded is preferred.
Extrusion molding can be performed using a general-purpose extrusion molding machine. The extrusion temperature is appropriately set according to various conditions such as the melting point and extrusion speed (take-off speed) of the non-halogen flame-retardant resin composition. When the non-halogenated flame retardant resin composition of the present invention is a crosslinkable resin composition, in order to suppress the occurrence of crosslinking reaction, the temperature is lower than the temperature at which the crosslinking reaction occurs (for example, the decomposition temperature of organic peroxide). Set. Such extrusion temperature is preferably set to, for example, the same temperature as the kneading temperature in the method for preparing the halogen-free flame-retardant resin composition of the present invention. Other extrusion molding conditions are set appropriately.
A method for disposing the non-halogen flame retardant resin composition of the present invention on the outer peripheral surface of a conductor (arranging the non-halogen flame retardant resin composition) is a method for disposing the non-halogen flame retardant resin composition of the present invention on the outer peripheral surface of a conductor using an extruder. It can also be carried out as a series of steps (all at once) continuously with the composition preparation method (preparation of a non-halogen flame retardant resin composition in an extruder).

When the halogen-free flame-retardant resin composition of the present invention is a crosslinkable resin composition, the halogen-free flame-retardant resin composition placed on the outer peripheral surface of the conductor is then subjected to a crosslinking reaction treatment. For this crosslinking reaction treatment, methods and conditions commonly applied to each crosslinking method applied to a crosslinkable composition can be applied without particular limitation. For example, in the case of peroxide crosslinking, a conductor on which the halogen-free flame-retardant resin composition of the present invention is disposed on the outer peripheral surface (extrusion molding, extrusion coating) is permeated using a heating device such as a heating furnace or a heating tube. An example is a method of heating to a temperature higher than the temperature at which the oxide decomposes. In the case of an electron beam crosslinking method, for example, a method of irradiating an electron beam at a dose of 1 to 30 Mrad can be mentioned. In the case of silane crosslinking method, it is brought into contact with water.

In this way, by using the non-halogenated flame-retardant resin composition of the present invention, wiring materials having a coating layer with excellent flame retardance and mechanical properties can be produced at high production rates without placing an excessive load on the molding machine. It can be manufactured by

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited thereto.
In Tables 1 to 4 below, the numerical values regarding the blending amount in each example are based on mass unless otherwise specified. Note that a blank column indicates that the blending amount of the corresponding component is 0% by mass or 0 part by mass.

Details of each compound used in Examples and Comparative Examples are shown below.
<Base resin>
(Ethylene vinyl acetate copolymer)
V421: Product name, manufactured by Mitsui Dow Polychemicals, MFR4, VA amount 28% by mass
EV260: Product name, manufactured by Mitsui Dow Polychemicals, MFR6, VA amount 28% by mass
EV450: Product name, manufactured by Mitsui Dow Polychemicals, MFR15, VA amount 25% by mass
EV270: Product name, manufactured by Mitsui Dow Polychemicals, MFR1, VA amount 28% by mass
EV 45LX: Product name, manufactured by Mitsui Dow Polychemicals, MFR2.5, VA amount 46% by mass
V406: Product name, manufactured by Mitsui Dow Polychemicals, MFR20, VA amount 20% by mass
EV150: Product name, manufactured by Mitsui Dow Polychemicals, MFR30, VA amount 33% by mass
Note that MFR is a value measured under conditions of a measurement temperature of 190° C. and a load of 2.16 kg, and the unit is g/10 min. Further, the VA amount is the vinyl acetate content in the ethylene vinyl acetate copolymer, and the unit is mass %.

(Ethylene-ethyl acrylate copolymer)
Rexpar A4200: Product name, manufactured by Nippon Polyethylene Co., Ltd., MFR5, EA amount 20% by mass
Rexpar A4250: Product name, manufactured by Nippon Polyethylene Co., Ltd., MFR5, EA amount 25% by mass
Note that MFR is a value measured under conditions of a measurement temperature of 190° C. and a load of 2.16 kg, and the unit is g/10 min. Further, the EA amount is the ethyl acrylate content in the ethylene-ethyl acrylate copolymer, and the unit is mass %.

(Acid-modified polyolefin polymer)
L6100M: Product name, manufactured by Japan Polyethylene Co., Ltd., maleic acid-modified polyethylene (α-olefin polymer)
LLDPE: Evolu SP0540 (product name), manufactured by Prime Polymer, MFR3.8
LLDPE: Evolu SP2320 (product name), manufactured by Prime Polymer, MFR2
Note that MFR is a value measured under conditions of a measurement temperature of 190° C. and a load of 2.16 kg, and the unit is g/10 min.

<Metal hydrate>
Aluminum hydroxide: BF013S (trade name), average particle size 1 μm, surface treatment agent: fatty acid (stearic acid), Nippon Light Metal Co., Ltd. Aluminum hydroxide: BF013 (trade name), average particle size 1 μm, no surface treatment, Nippon Light Metal Made by company,
<Clay minerals and quaternary ammonium salts>
BYK-MAX CT 4260: Trade name, manufactured by BYK, aluminum silicate treated with ammonium salt (used as a mixture or composite of clay mineral and quaternary ammonium salt as described above).

<Other additives>
(Flame retardant aid)
Melamine cyanurate: MC6000 (trade name), average particle size 5 μm, manufactured by Nissan Chemical Co., Ltd. Zinc sulfide: Sahatris HD-S (trade name), manufactured by Sactkeben (dispersant)
BYK-MAX P4102: Product name, fatty acid ester, TEGOMER (registered trademark) manufactured by BYK V-Si 4042: Product name, organically modified siloxane, manufactured by Evonik (anti-aging agent)
Irganox 1010: Trade name, pentaerythritol tetrakis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), manufactured by BASF Japan (lubricant)
Zinioplast gum: Product name, silicone gum, manufactured by Asahi Kasei Wacker Silicone Co., Ltd. Sakura stearate: Product name, manufactured by NOF Corporation (coloring agent)
Black color batch: PE-M 90086 (KE) 40-2 (AL) Black: Product name, manufactured by Dainichiseika Kogyo Co., Ltd. (calcined kaolin)
Satenton SP-33: Product name, manufactured by BASF Trunks Link 37: Product name, Surface treatment agent: Vinyl silane treatment, manufactured by BASF

[Examples 1 to 23 and Comparative Examples 1 to 12]
(Preparation and molding of non-halogen flame retardant resin composition)
Each component shown in Tables 1 to 4 was put into a 2L intensive mixer (manufactured by Nippon Roll Co., Ltd.), kneading was started at 140 to 150°C, and kneaded for 7 minutes at a rotor rotation speed of 40 to 45 rpm. Subsequently, the mixture was kneaded at 160 to 170°C for 3 minutes and discharged at an internal temperature of 160 to 170°C to prepare non-halogen flame retardant resin compositions.
Next, this non-halogen flame-retardant resin composition was cut into a sheet with a thickness of 2.8 to 3.4 mm using a roll processing machine (8-inch open roll, manufactured by Santetsu Co., Ltd.), and a press-molded mold plate was formed. A sheet-like test piece was obtained as a sheet for a press sheet.
In addition, a portion of the non-halogen flame retardant resin composition was pelletized.

The following tests were conducted on each test piece made from the prepared non-halogen flame retardant resin composition, and the results are shown in Tables 1 to 4.

<Evaluation of moldability>
(Measurement of MFR)
The MFR of the prepared non-halogen flame retardant resin composition was measured based on the method specified in JIS K 7210-1 at a measurement temperature of 190° C. and a load of 10 kg.
The measured MFR values are shown in Tables 1 to 4. When the MFR value falls within the range of the following evaluation criteria "〇", the non-halogen flame retardant resin composition exhibits good flowability and good moldability (passing level of this test). On the other hand, if it falls within the range of the following evaluation criteria "x", the flowability of the halogen-based flame-retardant resin composition will be poor, the load during molding will be high, and the moldability will be poor.

- Evaluation criteria -
〇: 0.3g/10min or more ×: 0.3g/10min or less

(Laboplastomil test)
Kneading/extrusion molding evaluation test device: 250 cc (filling amount: 80%) of the prepared non-halogen flame-retardant resin composition was charged into Labo Plastomill 10C100 (product name, manufactured by Toyo Seiki Co., Ltd.) within 30 seconds, and after 30 seconds Within seconds and 40 seconds after the start of preheating, the test was started at a temperature of 170° C. and a rotation speed of 40 rpm.
Tables 1 to 4 show the results of measuring the maximum torque and steady torque after 4 to 6 minutes during the test. The evaluation was performed by applying the kneading load compared to a standard material with a proven track record and applying it to the evaluation criteria below. ``◎'' and ``〇'' are the passing level of this test, indicating excellent formability.

- Evaluation criteria -
Maximum torque ◎: Torque 100N・m or less (sufficiently low, melt viscosity is also sufficiently low)
〇: Torque exceeding 100 N・m and below 150 N・m (Steady torque is equivalent to proven materials and there is no problem with workability)
×: Torque exceeds 150 N・m (steady torque is high, making extrusion molding difficult)

Steady torque (4-6min)
◎: Torque 80N・m or less (sufficiently low, melt viscosity is also sufficiently low)
〇: Torque exceeding 80 N・m and below 95 N・m (steady torque is equivalent to proven materials and there is no problem with workability)
×: Torque exceeds 95 N・m (steady torque is high, making extrusion molding difficult)

<Mechanical property test>
(Preparation of test piece)
Using an extruder (cylinder diameter 25 mm, L/D = 22) set at a die temperature of 170°C, pellets of the non-halogen flame-retardant resin compositions prepared in each example and comparative example were cut into 1 mm thick and wide pellets. A 25 mm tape sample was extruded. From this tape-shaped sample, a "No. 3 dumbbell test piece" specified in JIS K 6251 (2010) was prepared. However, the thickness shall be 1 mm.
(Measurement of mechanical properties)
Using the prepared test piece, a tensile test was conducted under the following conditions according to the method specified in JIS K 6251, and the tensile strength and elongation at break were measured. The results are shown in Tables 1 to 4.
If the tensile strength falls within the range of the following evaluation criteria "◎", the halogen-free flame retardant resin composition is deemed to exhibit high strength and is considered to be at a passing level in this test. Furthermore, if the elongation at break falls within the range of the following evaluation criteria "◎", the halogen-free flame retardant resin composition is considered to exhibit excellent elongation and is considered to be at a passing level in this test.

- Test condition -
Distance between gauge lines: 20mm
Tensile speed: 200mm/min
Test conditions are based on JIS K 6251.

- Evaluation criteria -
(Tensile strength)
◎: 5MPa or more (passing level of this test)
×: Less than 5 MPa (fail)
(Elongation at break)
◎: 150% or more (passing level for this exam)
×: Less than 150% (fail)

<Flame retardancy>
(Flame retardancy [A]: Single line flame retardancy test (IEC60332-1))
- Preparation of test piece -
Using an extruder (cylinder diameter 25 mm, L/D = 22) set at a die temperature of 170°C, pellets of the non-halogen flame-retardant resin composition prepared in each example and comparative example were extruded into pellets with an outer diameter of 0.8 mm. A wiring material test piece (outer diameter 5.0 mm) having a coating layer on the outer circumferential surface of the conductor was prepared by extrusion coating the outer circumferential surface of a copper single-core conductor to a thickness of 2.1 mm.

- Flammability test -
A mixed gas of butane and air was used as a combustion gas and a flame was applied to a vertically arranged wiring material test piece for 60 seconds using a burner adjusted to an outer flame length of 38 mm, and then the flame was removed. The time from when the flame was removed until the flame was extinguished (burning time) was measured, and the presence or absence of dripping of the coating layer was checked.
Regarding the combustion time, the measured values are shown in Tables 1 to 4. The flame retardance was evaluated by applying the following evaluation criteria regarding the burning time and the presence or absence of dripping. Regarding the burning time, "◎" and "〇" are the passing level of this test, and regarding the presence or absence of dripping, "〇" is the passing level of this test.

- Evaluation criteria -
(burning time)
◎: Within 0 to 20 seconds ○: Over 20 seconds and within 60 seconds ×: Over 60 seconds

(Presence or absence of dripping)
〇: No dripping ×: There is dripping

(Char strength [B]: Char formation strength test)
- Flammability test -
Regarding the wiring material test piece after the above-mentioned flame retardancy [A] single-line flame retardancy test (IEC60332-1) test, a mandrel with an outer diameter of 1.2 mm was placed at the center of the flame contact area of the formed char at a speed of 1 mm/ It was made to penetrate perpendicularly to the conductor to a depth of 1 mm at min.
The load required to enter the mandrel was measured using the device below until reaching a depth of 1 mm, and the maximum load value among the measured load values was taken as the char formation strength (maximum value). . In addition, the average value of the measured load values was measured and calculated, and the obtained value was taken as the average strength of the char. The obtained values are shown in Tables 1 to 4. Flame retardancy was evaluated by applying the following evaluation criteria to the formed strength (maximum value) and average strength.
In this test, if the forming strength (maximum value) and average strength are ``◎'' or ``〇'', the char will be difficult to drip from the conductor during or after combustion, and a high degree of flame retardancy will be exhibited. exam passing level).

- Evaluation criteria -
(Formation strength (maximum value))
◎: 30 gf or more (sufficient char molding strength and no dripping)
〇: 10 gf or more, less than 30 gf (Char forming strength is slightly low, but dripping can be prevented)
×: Less than 10 gf (char formation is weak and collapses with slight vibration)

(average intensity)
◎: 20 gf or more (sufficient char molding strength and no dripping)
〇: 5 gf or more, less than 20 gf (char formation strength is slightly low and dripping can be prevented)
×: Less than 5 gf (char formation is weak and collapses with slight vibration)

(Flame retardancy [C]: sheet flammability test)
- Preparation of test piece -
Pellets of the non-halogen flame retardant resin compositions prepared in each of the Examples and Comparative Examples were molded into a 3 mm thick sheet using a hot press molding machine. A test piece was obtained by cutting out a rectangular test piece having a width of 6 mm, a thickness of 3 mm, and a length of 170 mm from the formed sheet.
- Flame retardancy test -
The prepared test piece was placed vertically, and a burner flame whose outer flame length was adjusted to 20 mm was applied for 60 seconds from the bottom end of the test piece (other than the flame contact time, the test was conducted according to the UL94 combustion test). . Note that propane gas was used as the combustion gas.
In this way, the test piece was brought into contact with the flame for a long period of 60 seconds and burned, and regardless of the time taken to extinguish the flame, it was observed whether the flame extinguished (self-extinguishing), and the combustion state was observed. The presence or absence of dripping and its extent were confirmed. The results were applied to the following evaluation criteria to evaluate whether a high degree of flame retardancy was exhibited.

- Evaluation criteria -
〇: No dripping and self-extinguishing ×: Dripping occurs or the flame does not go out

<Low temperature test>
(Preparation of test piece)
Using an extruder (cylinder diameter 25 mm, L/D = 22) set at a die temperature of 170°C, pellets of the non-halogen flame-retardant resin compositions prepared in each example and comparative example were made into 2 mm thick and wide pellets. A 25 mm tape sample was extruded. A test piece specified in JIS K 7216 (1980) was prepared from this tape-shaped sample. However, the thickness shall be 2 mm.
(Embrittlement test)
A low temperature test was conducted in accordance with JIS K 7216 (1980). Specifically, after each test piece was placed in a test temperature atmosphere of each level for 3 ± 0.1 minutes, a single impact was applied to the test piece with a percussion hammer at a specified test speed to determine whether or not the test piece was broken. I looked into it.
This low-temperature property test varies greatly depending on the installation environment of the wiring material, but since use at extremely low temperatures is not required, this test evaluates the characteristics required of general wiring materials, and is a reference test.

- Evaluation criteria -
〇: Breaking point (test temperature) at which 50% of the test piece breaks is -25°C or lower (pass)
×: Breaking point (test temperature) at which 50% of the test piece breaks exceeds -25°C (fail)

As is clear from the results shown in Tables 1 to 4, 100 to 250 parts by mass of metal hydrate and 2 to 30 parts by mass of clay mineral and quaternary ammonium salt were added to the base resin having a specific composition. Some of the non-halogen-based flame-retardant resin compositions of Comparative Examples 1 to 12 that do not contain the same proportions do not satisfy flame retardancy [A] or [B], and have high moldability, high flame retardancy, and excellent mechanical properties. Unable to discuss characteristics.
In contrast, a base resin containing 60 to 95% by mass of EVA or EEA having a specific amount of VA or EA and a specific MFR and 5 to 40% by mass of an acid-modified polyolefin polymer, and a metal hydrate. 100 to 250 parts by mass, and a total of 2 to 30 parts by mass of clay mineral and quaternary ammonium salt, and the non-halogen of Examples 1 to 23 satisfying flame retardancy [A] and char strength [B] All flame-retardant resin compositions exhibit high degree of flame retardancy while exhibiting high moldability and excellent mechanical properties. From these test results, wiring materials with coating layers formed from the non-halogenated flame-retardant resin compositions of Examples 1 to 23 can be manufactured with high productivity, and have excellent mechanical properties while exhibiting advanced It can be seen that it exhibits flame retardancy.

1, 2 Optical cable 10 Optical fiber core 11 Optical fiber core bundle 12 Nonwoven fabric tape 13 Tension member 20 Covering layer 21 Sheath

Claims (8)

Ethylene vinyl acetate copolymer with a vinyl acetate content or an alkyl (meth)acrylate content of 15 to 60% by mass and a melt flow rate (measurement temperature of 190°C, load of 2.16 kg) of 2 to 15 g/10 min. 100 to 100 parts by mass of a base resin containing 60 to 95% by mass of a polymer or ethylene-alkyl (meth)acrylate copolymer and 5 to 40% by mass of an acid-modified polyolefin polymer, 250 parts by mass, and a total of 2 to 30 parts by mass of clay minerals and quaternary ammonium salts, and satisfies [A] and [B] below.

[A] A wiring material having an outer diameter of 5 mm and having a coating layer with a thickness of 2.1 mm formed from the above-mentioned non-halogen flame-retardant resin composition on the outer peripheral surface of a copper single-core conductor with an outer diameter of 0.8 mm was prepared. In a single line combustion test specified in IEC60332-1 using wiring materials, there should be no dripping during combustion and self-extinguishing within 60 seconds [B] At the center of the flame contact part of the char formed in the single line combustion test, When a mandrel with an outer diameter of 1.2 mm is advanced to a depth of 1 mm at a speed of 1 mm/min, the char formation strength is 10 gf or more, and the average strength is 5 gf or more. The non-halogen flame-retardant resin composition according to claim 1, which has a melt flow rate (measured temperature: 190° C., load: 10 kg) of 0.3 to 2.5 g/10 min or less. The non-halogen flame-retardant resin composition according to claim 1 or 2, wherein the base resin contains 5 to 20% by mass of an α-polyolefin polymer. The non-halogen flame retardant resin composition according to claim 3, wherein the α-olefin polymer contains at least one of polyethylene and polypropylene. The non-halogen according to any one of claims 1 to 4, wherein the acid-modified polyolefin polymer contains at least one of maleic anhydride-modified polyethylene, acrylic acid-modified polyethylene, maleic anhydride-modified polypropylene, and acrylic acid-modified polypropylene. flame-retardant resin composition. A wiring material having a coating layer on the outer peripheral surface of a conductor,
A wiring material, wherein the coating layer is formed of the halogen-free flame-retardant resin composition according to any one of claims 1 to 5. The wiring material according to claim 6, wherein the wiring material is an insulated wire or a power cable. The wiring material according to claim 6 or 7, wherein the wiring material is an optical cable.

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