JP4686156B2 - Whitening-resistant flame-retardant resin composition, extruded product thereof, and electric wire / cable having a coating layer obtained by extrusion molding - Google Patents

Description

  The present invention relates to a whitening-resistant flame-retardant resin composition having excellent whitening resistance, an extruded product thereof, and an electric wire / cable having a coating layer obtained by extrusion-molding it.

  Conventionally, as flame retardants for resins and rubbers, halogen-containing compounds and those using a combination of these with phosphorus-containing compounds have been used. Many uses of magnesium oxide have been proposed (for example, see Patent Documents 1 to 4).

However, if the magnesium hydroxide is not compounded in a relatively large amount, flame retardancy cannot be obtained, and the compatibility between the resin such as olefin resin and rubber and magnesium hydroxide is poor, and the resulting flame retardant resin composition There is also a problem with dispersibility of magnesium hydroxide in water and water resistance, and there is a problem that magnesium hydroxide turns white into basic magnesium carbonate when it reacts with water and carbon dioxide in the air.
This phenomenon of white alteration is recognized by visual observation of the appearance, and can be evaluated as an increase in the mass of the resin composition due to the production of magnesium carbonate and the like. However, if there is no increase in mass, there is almost no whitening, but there is no primary relationship between the degree of whitening of the appearance and the increase in mass. Can be large. And when this whitening occurs and this is used as a coating layer of an electric wire / cable, etc. as an extrusion-molded product, there is a problem that especially the whitening of the external appearance cannot be wiped off and the product value is significantly reduced.

For this reason, in Patent Document 1, the surface of magnesium hydroxide is surface-treated with either a fatty acid, a fatty acid metal salt, a titanate coupling agent or a silane coupling agent, and magnesium hydroxide having a specific particle diameter is blended. A flame retardant electrical insulating composition is proposed, and the effect of improving compatibility is described.
Patent Documents 2 and 3 use natural minerals mainly composed of magnesium hydroxide as magnesium hydroxide, and are selected from fatty acids, fatty acid metal salts, silane coupling agents, and titanate coupling agents. In addition, about 0.5 to 5% by weight of a surface treatment agent containing at least one kind as a main component is added to a plastic or rubber, and is added to plastic or rubber to provide flame resistance as well as acid resistance and moisture absorption. A composition is described which suppresses the above.
Furthermore, Patent Document 4 describes a flame retardant olefin resin composition comprising an olefin resin and a natural mineral mainly composed of magnesium hydroxide having a specific particle size parameter, ensuring acid resistance, It is described that an extruded product having a surface smoothness can be obtained.
Further, Japanese Patent Application No. 2003-285529 filed by the present applicant describes surface-treated magnesium hydroxide surface-treated with a polyhydric alcohol higher fatty acid ester as a surface treating agent, and a flame retardant comprising this and a resin or rubber. The flame retardant resin composition has mechanical properties, water resistance and carbon dioxide whitening resistance, and the balance of these can be adjusted.

  However, the whitening of the appearance and the increase in mass due to the reaction with carbon dioxide gas / water are caused by any of the above-mentioned techniques. In particular, when the whitening of the appearance occurs, the commercial value is lost. There has been a demand for the development of a flame retardant resin composition having a stronger (whitening resistance).

Japanese Patent Laid-Open No. 60-100302 JP-A-5-17692 JP 7-161230 A JP 2002-363349 A

  The object of the present invention is to provide surface-treated hydroxylation of a resin or rubber and a higher fatty acid ester of a polyhydric alcohol, which already has an excellent whitening resistance at a practical level and is capable of adjusting the balance between this and mechanical properties. In the flame-retardant resin composition containing magnesium, the whitening resistance further comprising whitening of the external appearance (hereinafter referred to as whitening of the external appearance) and mass increase (hereinafter referred to as whitening of the carbon dioxide gas) is comprehensively achieved. An object of the present invention is to provide a whitening-resistant flame-retardant resin composition having enhanced appearance whitening property, an extruded product thereof, and an electric wire / cable having a coating layer obtained by extrusion molding thereof.

In order to solve the above-mentioned problems, the present inventors have studied various additives for enhancing whitening resistance, particularly appearance whitening resistance. As a result, the surface-treated water of a resin or rubber and a higher fatty acid ester of a polyhydric alcohol is used. In the flame-retardant resin composition containing magnesium oxide, one or more whitening assistants selected from the group consisting of vegetable oil, higher fatty acid and higher fatty acid metal salt , soybean oil, stearic acid, and sodium stearate In addition to the fact that the whitening resistance already having practical value has been strengthened, and in particular, the whitening resistance to appearance has been strengthened, the contained surface-treated magnesium hydroxide is a resin. Or, it has excellent compatibility and dispersibility with rubber, the mechanical properties of the obtained flame-retardant resin composition are excellent, and the extrusion moldability is secured, so that the object of the present invention can be achieved. It was heading. The present invention has been completed based on these findings.

That is, according to the first invention of the present invention, a resin composition comprising a resin or rubber, and a surface-treated magnesium hydroxide of a polyhydric alcohol higher fatty acid ester, further comprising soybean oil, stearic acid, and sodium stearate. 1 or more types of whitening-resistant adjuvant chosen from the group which consists of, The compounding ratio of a resin composition is the surface treatment magnesium hydroxide of polyhydric alcohol higher fatty acid ester with respect to 100 mass parts of resin or rubber | gum. A whitening-resistant flame-retardant resin composition is provided, which is 50 to 250 parts by mass and 0.05 to 3 parts by mass of a whitening assistant.

According to the second invention of the present invention, in the first invention, the polyhydric alcohol higher fatty acid ester is a glycerol-stearic acid ester having an esterification rate of 40 to 90%. A whitening flame retardant resin composition is provided.
Furthermore, according to the third invention of the present invention, there is provided a whitening-resistant flame-retardant resin composition characterized in that, in the first or second invention, the resin or rubber is an ethylene-based resin.

On the other hand, according to the fourth invention of the present invention, there is provided an extrusion molded product obtained by extrusion molding the whitening-resistant flame-retardant resin composition according to any one of the first to third inventions. Is done.
Moreover, according to 5th invention of this invention, the electric wire and cable which have a coating layer obtained by extrusion-molding the whitening-resistant flame-retardant resin composition which concerns on any 1st- 3rd invention are provided. Is done.

As described above, the present invention is a resin composition comprising a resin or rubber and a polyhydric alcohol higher fatty acid ester surface-treated magnesium hydroxide, and is further selected from the group consisting of soybean oil, stearic acid, and sodium stearate. A whitening-resistant flame-retardant resin composition containing a specific amount of one or more whitening-resistant assistants, an extruded product thereof, and an electric wire / cable having a coating layer obtained by extrusion-molding the composition. Surface treatment magnesium hydroxide of higher fatty acid ester has excellent compatibility with resin or rubber and higher fatty acid ester of polyhydric alcohol, and also has excellent dispersibility, resulting in flame retardant resin composition in addition to being excellent mechanical properties of the object, the extrusion moldability while maintaining, already whitening resistance comprehensive with practical value, among them resistance to outer appearance whitening resistance, soybean oil, Stearate, and by blending one or more whitening aid selected from the group consisting of sodium stearate, it has been intensified.
Note that this soybean oil, stearic acid, and mechanism of action against whitening resistance of one or more whitening aid selected from the group consisting of sodium stearate is not explicitly elucidated, soybean oil, stearic According to the present invention, one or more whitening assistants selected from the group consisting of an acid and sodium stearate are provided by the action of covering an incomplete part of the surface treatment of magnesium hydroxide. Et al.

  Hereinafter, the whitening-resistant flame-retardant resin composition of the present invention, an extruded product thereof, and an electric wire / cable having a coating layer obtained by extrusion molding thereof will be described in detail for each item.

1. Resin or Rubber Examples of the resin used in the present invention include thermoplastic resins such as polyolefin resin, methacrylic resin, acrylic resin, vinyl acetate resin, and saturated polyester resin.
In these, the olefin resin which has only nonpolarity or weak polarity can be used conveniently.

Examples of the olefin resins include ethylene resins and propylene resins. In the present invention, ethylene resins that have been proven as insulating coating layers for electric wires and cables can be used as particularly suitable resins.
Examples of the ethylene resin include high-pressure polyethylene, ethylene-α-olefin (carbon number 2 to 12) copolymer, ethylene-α, β-unsaturated carboxylic acid alkyl ester copolymer, and ethylene-carboxylic acid vinyl ester copolymer. Specifically, high pressure method low density polyethylene, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-butyl methacrylate copolymer Examples thereof include a copolymer, an ethylene-vinyl acetate copolymer, an ethylene-butene-1 copolymer, an ethylene-hexene-1 copolymer, and an ethylene-octene-1 copolymer.

In the present invention, an ethylene-ethyl acrylate copolymer or ethylene-, which is itself compatible with magnesium hydroxide, has a melt mass flow rate of 0.05 to 50 g / 10 min and a comonomer content of 5 to 40% by mass. A vinyl acetate copolymer and a linear low density ethylene-α-olefin copolymer having a melt mass flow rate of 0.05 to 50 g / 10 min and a density of 0.86 to 0.92 g / cm ³ are preferably used. Can be used.

  Specific examples of the propylene-based resin include a propylene homopolymer, an ethylene-propylene copolymer, and an ethylene-propylene-butene-1 terpolymer.

As rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, acrylic rubber, styrene-ethylene-propylene-styrene block copolymer, styrene-ethylene-butadiene-styrene block copolymer, styrene-ethylene-styrene block copolymer Examples include coalescence.
In addition, resin or rubber | gum can be used 1 type or in combination of 2 or more types.

2. Surface-treated magnesium hydroxide of polyhydric alcohol higher fatty acid ester (hereinafter also simply referred to as surface-treated magnesium hydroxide)
Examples of the polyhydric alcohol constituting the polyhydric alcohol higher fatty acid ester used as the surface treating agent for the surface-treated magnesium hydroxide used in the present invention include trimethylolethane, glycerin, trimethylolpropane, erythritol, pentaerythritol and the like. Can be mentioned. Among the polyhydric alcohols, glycerin is preferably used.

  The higher fatty acid constituting the polyhydric alcohol higher fatty acid ester used as the surface treatment agent for the surface-treated magnesium hydroxide used in the present invention includes stearic acid, oleic acid, palmitic acid, linoleic acid, lauric acid, Examples include caprylic acid, behenic acid, and montanic acid. Among the higher fatty acids, stearic acid is preferably used.

The esterification rate of the polyhydric alcohol higher fatty acid ester means the percentage of the group that has been esterified among a plurality of hydroxyl groups of the polyhydric alcohol. For example, the esterification rate of glycerin-monostearic acid ester is 33.3%.
The esterification rate of the polyhydric alcohol higher fatty acid ester used in the present invention is desirably 40 to 90%, and preferably 50 to 85%.
When the esterification rate is around 50%, the mechanical properties, particularly the tensile fracture stress, of the resin composition containing the surface-treated magnesium hydroxide is improved. Further, when the esterification rate increases, a slight decrease in mechanical properties is recognized, but this is not a problem in practical use.
On the other hand, as the esterification rate increases, the whitening resistance of the resin composition containing the surface-treated magnesium hydroxide increases.
Thus, in the present invention, by adjusting the esterification rate, it is possible to impart desired mechanical properties and whitening resistance to the resin composition containing the surface-treated magnesium hydroxide.

The surface treatment amount with respect to magnesium hydroxide of the polyhydric alcohol higher fatty acid ester which is a surface treatment agent for surface-treated magnesium hydroxide is desirably 0.5 to 5.0% by mass, preferably 1.0 to 4.0% by mass. %, More preferably 1.5 to 3.5% by mass.
When the surface treatment amount is less than 0.5% by mass, it becomes difficult to cover the entire surface of the magnesium hydroxide, and both the mechanical properties and the whitening resistance of the resin composition containing the surface treatment magnesium hydroxide are lowered. On the other hand, if this exceeds 5.0% by mass, the effect of magnesium hydroxide as a flame retardant is reduced, and particularly when a polyhydric alcohol higher fatty acid ester having an esterification rate of less than 40% is used, the surface coating The resin composition containing the surface-treated magnesium hydroxide begins to be inferior in whitening resistance, although it is superior to the case where it is not.

  In the present invention, two or more polyhydric alcohol higher fatty acid esters can be used as the surface treatment agent, and in addition to one ester of polyhydric alcohol and one higher fatty acid, Esters of polyhydric alcohols and one or more higher fatty acids can also be used as the polyhydric alcohol higher fatty acid esters.

  As magnesium hydroxide used in the present invention, natural ore mainly composed of magnesium hydroxide produced by pulverizing synthetic magnesium hydroxide produced from seawater or the like and natural brucite ore (hereinafter referred to as natural product) Any of these may also be suitably used, and the average particle size is preferably 40 μm or less, particularly preferably 0.2 to 6 μm, in view of dispersibility and flame retardancy.

  From the viewpoint of whitening resistance, natural magnesium hydroxide is preferred. Naturally produced magnesium hydroxide is pulverized to adjust the average particle size. In this case, if it is ground to the synthetic magnesium hydroxide level, it is thought to be due to the destruction of the crystal system, but the whitening resistance becomes poor, so when using natural magnesium hydroxide, the average particle size It is more desirable that the ratio of 4 μm or more is 50% or less (number basis) and the average particle size is 1.5 μm to 6 μm.

The surface-treated magnesium hydroxide of the present invention may be surface-treated by a known surface treatment method and is not particularly limited.
For example, in the case of synthetic magnesium hydroxide produced from sea water, magnesium hydroxide crystallizes in an aqueous solution. Therefore, a desired amount of a polyhydric alcohol higher fatty acid ester is added to this aqueous solution, and a solvent such as alcohol if necessary. It is possible to produce a surface-treated magnesium hydroxide that is surface-treated with a polyhydric alcohol higher fatty acid ester after being diluted and blended, and dried after precipitation.
Synthetic magnesium hydroxide and natural magnesium hydroxide can be produced by employing a slurry method in which, for example, an organic solvent liquid of a polyhydric alcohol higher fatty acid ester is added and mixed.

Furthermore, in addition to the so-called wet method described above, surface treatment can also be performed by a dry method described below.
Already, a desired amount of a higher fatty acid ester of polyhydric alcohol is added to synthetic magnesium hydroxide or natural magnesium hydroxide having an average particle size according to the purpose of use and heated to a temperature above which it melts, for example, 100 to 120 ° C. While stirring and mixing. In this case, a known mixer such as a continuous mixer, a Banbury mixer, a kneader, a super mixer, or a ball mill may be used.
In addition, since natural magnesium hydroxide is used after being pulverized, coarsely pulverized natural magnesium hydroxide and a desired amount of a higher fatty acid ester of a polyhydric alcohol are put into a ball mill or other pulverizer, and if necessary, a large amount is externally added. The surface treatment may be performed simultaneously with pulverization while heating to a temperature at which the higher alcohol higher fatty acid ester dissolves.

3. Whitening Auxiliary Auxiliary whitening assistant used in the present invention, which is one or more vegetable oils selected from the group consisting of soybean oil, stearic acid, and sodium stearate , higher fatty acids or higher fatty acid metal salts , is described below. To do.

Examples of vegetable oils include soybean oil, linseed oil, cottonseed oil, rapeseed oil, pepper seed oil, cocoon seed oil, nasturtium seed oil, castor oil, and the like . In the present invention, soybean oil is used.

Examples of higher fatty acids include saturated fatty acids having 15 or more carbon atoms and unsaturated fatty acids. Specific examples of saturated fatty acids include palmitic acid, stearic acid, behenic acid, and the like. Examples thereof include oleic acid, erucic acid, ricillic acid, linolenic acid, linoleic acid and the like . In the present invention , stearic acid is used among these.

Examples of the higher fatty acid metal salt include sodium salts, calcium salts, magnesium salts, zinc salts, potassium salts, barium salts, aluminum salts, lithium salts and the like of the above higher fatty acids. Among these , in the present invention, among these, Sodium stearate is used.

Further, soybean oil, stearic acid, and sodium stearate, which are whitening assistants in the present invention, include soybean oil, stearic acid, and modified products of sodium stearate. Including chemicals.

In the present invention, the blending amount of one or more whitening assistants selected from the group consisting of soybean oil, stearic acid, and sodium stearate is 0.05 to 3 mass with respect to 100 parts by mass of the resin or rubber. Part, preferably 0.08 to 1.5 parts by weight, more preferably 0.3 to 1 part by weight.
If the blending amount is less than 0.05 parts by mass, the whitening resistance enhancement effect is insufficient, while if it exceeds 3 parts by mass, the whitening resistance is effective, but the heat resistance of the resin composition is reduced. If further using soybean oil, since this is blooming occurs come oozing to the surface, undesirable.
Note that one or more whitening assistants selected from the group consisting of soybean oil, stearic acid, and sodium stearate can be used alone or in combination of two or more.

4). Whitening-resistant flame-retardant resin composition The whitening-resistant flame-retardant resin composition of the present invention comprises a predetermined amount of resin or rubber, surface-treated magnesium hydroxide, soybean oil, stearic acid, and sodium stearate , respectively. One or more whitening assistants selected from the above, and other appropriate amounts of other compounds (stabilizer, antioxidant, ultraviolet absorber, light stabilizer, antistatic agent, nucleating agent, lubricant, Processability improver, filler, dispersant, copper damage inhibitor, neutralizer, foaming agent, anti-bubble agent, colorant, carbon black, carbon black masterbatch, and other flame retardants) For example, it can be produced by uniformly melt-kneading using a kneader, a Banbury mixer, a continuous mixer, a roll mill or an extruder.
The produced flame-retardant resin composition of the present invention is then preferably granulated into pellets having a particle size of about 2 to 7 mm and used for molding.

In the whitening-resistant flame-retardant resin composition of the present invention, the amount of the surface-treated magnesium hydroxide is 50 to 250 parts by mass, preferably 60 to 200 parts by mass with respect to 100 parts by mass of the resin or rubber. More preferably, it is 75 to 180 parts by mass.
If the blending amount is less than 50 parts by mass, the flame retardancy becomes insufficient. On the other hand, if it exceeds 250 parts by mass, the mechanical properties and extrusion processability are deteriorated, which is not desirable.

5. Extruded product The extruded product of the present invention is obtained by extruding the above whitening-resistant flame-retardant resin composition by using a known method using an extruder and heating and melting the composition. Can be manufactured.
When the extruded product is an electric wire / cable coating layer, it can be produced by similarly extruding and coating the core wire of the electric wire / cable as an insulating layer or a sheath layer by a known method.

  EXAMPLES Next, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples. In addition, preparation of the sample used in this specification and its evaluation are based on the following, respectively, except the method described individually.

[Sample preparation]
A predetermined amount of resin or rubber, surface-treated magnesium hydroxide, whitening-resistant auxiliary agent, and if necessary, other appropriate amount of other compounds are charged into a Banbury mixer and melt-kneaded at 200 ° C. for 10 minutes to obtain a resin composition. From this, a pellet having an average particle diameter of about 4 mm was obtained, and this was preheated to 160 ° C. for 5 minutes, 150 kgf pressurized for 3 minutes, and finally cooled to 23 ° C. while maintaining the pressure to 1 mm thick. A sheet was obtained and used as a sample.

[Evaluation]
I. Whitening resistance The obtained sample (sheet) was punched out into a 3 cm × 5 cm rectangle with a dumbbell, and a test piece was prepared in which a hole having a diameter of about 5 mm was formed at the center of one side of the short side and suspended.
Using the obtained test piece, a carbon dioxide gas exposure test described below was performed to evaluate whitening resistance.

Carbon dioxide exposure test:
The test piece was hung in an atmosphere of room temperature (25 ° C.) and a relative humidity of 90% and a predetermined carbon dioxide concentration, and the test piece was taken out every predetermined time and evaluated.

I-1. Appearance whitening resistance Appearance whitening resistance was evaluated by the carbon dioxide gas exposure test described above, and the surface of the test piece after a predetermined period of time was visually evaluated based on the following eight levels.
Standard 0: No surface whitening is observed.
Standard 1: Faint surface whitening is observed.
Standard 2: Some whitening of the surface is observed.
Standard 3: Some whitening of the surface is observed.
Standard 4: Some whitening of the surface is observed.
Criterion 5: Many surface whitenings are observed.
Criterion 6: A considerable amount of surface whitening is observed.
Criterion 7: Remarkably whitening of the surface is observed on the entire surface.

I-2. Carbon dioxide gas whitening resistance Before starting the test, measure the mass of the test piece, conduct the carbon dioxide exposure test, take out the test piece after a predetermined time, and dry it at 80 ° C for 12 hours under reduced pressure of 1.3 kPa or less. After cooling, the mass was measured, divided by the initial mass, and expressed as a percentage. The larger this value, the worse the carbon dioxide whitening resistance.
Note that, as described above, the appearance whitening resistance and the carbon dioxide gas whitening resistance do not necessarily match.

II. Mechanical properties II-1. Tensile Fracture Stress Tensile fracture stress test was performed on a test piece punched with a No. 3 dumbbell specified in 4.1 of JIS K6251 in accordance with JIS C3005. Three test pieces were measured and evaluated by average value.

II-2. Tensile Fracture Strain A tensile fracture strain test was performed in accordance with JIS C3005 using a test piece similar to the tensile fracture stress test. Three test pieces were measured and evaluated by average value.

[Comparative Example 1, Examples 1-6]
Using carbon black (Vulcan 9A-32, manufactured by Cabot) and ethylene-butene-1 copolymer (melt mass flow rate 1 g / 10 min, density 0.918 g / cm ³ , GMM-1810, manufactured by Nihon Unicar) A carbon black masterbatch containing 36% by mass of carbon black was prepared by melt-kneading at 200 ° C. for 10 minutes and granulating to an average particle diameter of 4 mm.
The ethylene-butene-1 copolymer and the carbon black masterbatch prepared above were blended so that 4.6 parts by mass of carbon black per 100 parts by mass of resin (ethylene-butene-1 copolymer) was blended. Mixed.
Surface treatment magnesium hydroxide per 100 parts by mass of the above resin [2.7% by mass of glycerin-stearate with an average esterification rate of 50%, natural magnesium hydroxide (Magsee's W, manufactured by Kamishima Chemical Co., Ltd.) by the dry method. Processed] 100 parts by mass and tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane as an antioxidant blended to be 1 part by mass Then, the resin composition of Comparative Example 1 was obtained, and a sample was prepared therefrom.

Furthermore, as whitening assistant, soybean oil, stearic acid (NAA-180, manufactured by NOF Corporation), sodium stearate (non-Sal SN-1, manufactured by NOF Corporation), 0.4 parts by mass and 0.6 parts by mass, respectively. Samples made of the resin compositions of Examples 1 to 6 were prepared in the same manner as in Comparative Example 1 except that they were additionally blended.
The composition of each resin composition is shown in Table 1.
The obtained samples were evaluated for whitening resistance and mechanical properties, and the results are shown in Table 1.
Regarding the mechanical properties, any of the resin compositions of Comparative Example 1 and Examples 1 to 6 were equivalent and suitable.
In the whitening resistance test, in any case after 7 days and 14 days after the exposure carbon dioxide concentration of 100% in the carbonic acid exposure test, in the appearance whitening resistance evaluated visually, those of Examples 1 to 6 It was clearly superior to Comparative Example 1. Moreover, also about the carbon dioxide-whitening resistance evaluated by the mass increase rate, the thing of Examples 1-6 was superior to the comparative example 1, and the clear difference was recognized.
The carbon dioxide exposure test for Comparative Example 1, Examples 2, 4, and 6 was also performed for the exposure carbon dioxide concentrations of 40% and 10%, and the whitening start time when whitening was visually recognized as the standard 1 for the first time. Was measured.

Since the reaction rate is calculated by an exponential function, in order to estimate the whitening start time in the atmosphere where the carbon dioxide concentration is 0.03%, the logarithmic graph paper consisting of the carbon dioxide concentration axis and the whitening start time axis is used. The obtained numerical values were plotted, and the whitening start time in the atmosphere was estimated and compared.
FIG. 1 shows logarithmic graphs of Comparative Example 1 and Examples 2, 4 and 6. The whitening start times of Comparative Example 1, Examples 2, 4 and 6 are 229 hours, 1011 hours and 905 hours, respectively. In Example 2, the whitening start time is 4.4 times that of Comparative Example 1, 4.0 times in Example 4, and 4.1 times in Example 6, and the whitening resistance of the present invention is obtained. It was confirmed that the flame retardant resin composition has excellent whitening resistance overall, and in particular, the whitening resistance to appearance is enhanced.

[Comparative Examples 2 to 4, Examples 7 to 9]
The resin compositions of Comparative Examples 2 to 4 and Examples 7 to 9 were used in the same manner as in Examples 1, 3 and 5 except that the blending amount of the whitening assistant was changed to 5 parts by weight and 1.8 parts by weight. Each sample was prepared.
The composition of each resin composition is shown in Table 2.
The obtained samples were evaluated for whitening resistance and mechanical properties, and the results are shown in Table 2.
About the mechanical characteristics, any resin composition of Comparative Examples 2-4 and Examples 7-9 was equivalent and suitable.
In the whitening resistance test, Comparative Examples 2 to 4 and Example 7 in the appearance whitening resistance visually evaluated in 7 days and 14 days after the exposure carbon dioxide concentration of 100% in the carbonic acid exposure test. Although those of ˜9 were equivalent, blooming was observed in Comparative Example 2, and although not shown in the table, those of Comparative Examples 2-4 were more heat resistant than those of Examples 7-9. Decreased. Furthermore, the carbon dioxide whitening resistance evaluated by the mass increase rate was as excellent as in Examples 7 to 9, but the effect of carbon dioxide whitening resistance was almost the same as in Examples 7 to 9 and the effect. Was determined to be saturated.

[Comparative Example 5, Example 10]
Samples were prepared by obtaining the resin compositions of Comparative Examples 5 and 10, respectively, in the same manner as Comparative Examples 1 and 2, except that the amount of the surface-treated magnesium hydroxide was 150 parts by mass.
The composition of the obtained resin composition and the evaluation results thereof are shown in Table 3. Regarding the mechanical properties, the resin composition of Example 10 was equivalent to that of Comparative Example 5 and was suitable. However, the appearance whitening resistance evaluated visually was that of Example 10 was clearly superior to that of Comparative Example 5. In addition, the carbon dioxide gas whitening resistance evaluated by the mass increase rate is also superior, and a clear difference is recognized, which has an overall excellent whitening resistance, in particular, the appearance whitening resistance is enhanced. It was recognized that

[Comparative Example 6, Example 11]
Carbon black (Vulcan 9A-32, manufactured by Cabot Corporation) and ethylene-ethyl acrylate copolymer (melt mass flow rate 0.5 g / 10 min, ethyl acrylate content 23 mass%, NUC-831, manufactured by Nihon Unicar) The resulting mixture was melt-kneaded at 200 ° C. for 10 minutes, granulated, and a carbon black masterbatch containing 36% by mass of carbon black was prepared.
The obtained carbon master batch, the ethylene-ethyl acrylate copolymer, surface-treated magnesium hydroxide (2.7% by mass of glycerin-stearate having an average esterification rate of 50%, natural magnesium hydroxide (Magsees W 100 parts by weight of tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] as an antioxidant. Using methane, in Example 11, further using soybean oil, the resin compositions of Comparative Example 6 and Example 11 were obtained, respectively, and samples were prepared.

The composition of each resin composition is shown in Table 4. Further, with respect to the obtained samples, the whitening resistance and mechanical properties were evaluated, and the results are shown in Table 4.
As for mechanical properties, the resin compositions of Comparative Example 6 and Example 11 were both equivalent and suitable.
Further, the obtained sample was evaluated for whitening resistance, and the results are shown in Table 4.
In the whitening resistance test, the appearance whitening resistance visually evaluated in either case after 7 days or 14 days after the exposure carbon dioxide concentration of 100% in the carbon dioxide exposure test was compared with that of Example 11. It was superior to Example 6. Moreover, it was recognized that the carbon dioxide gas whitening resistance evaluated by the mass increase rate was also superior and had comprehensively excellent whitening resistance, and in particular, the appearance whitening resistance was enhanced.

The whitening-resistant flame-retardant resin composition of the present invention is excellent in compatibility with the surface-treated magnesium hydroxide used in the resin or rubber, and already has whitening resistance. Furthermore, soybean oil, stearic acid, And one or more whitening-resistant assistants selected from the group consisting of sodium stearate, so that the appearance whitening resistance and carbon dioxide whitening resistance are maintained while maintaining suitable mechanical properties. The whitening property is comprehensively excellent, and in particular, the appearance whitening resistance is enhanced. In addition, since the extrudability is ensured, it can be effectively used as an extrudate such as a flame retardant cover, pipe, sheet, film, electric wire / cable coating layer, and the like.

The figure which plotted and estimated the whitening start time in the atmosphere of the whitening-resistant flame-retardant resin composition of the present invention (Examples 2, 4 and 6 and Comparative Example 1) on the carbon dioxide concentration axis and the whitening start time axis It is.

Claims (5)

In a resin composition comprising a resin or rubber, and a surface-treated magnesium hydroxide of a polyhydric alcohol higher fatty acid ester,
Furthermore, it comprises one or more whitening assistants selected from the group consisting of soybean oil, stearic acid, and sodium stearate, and the blending ratio of the resin composition is 100 parts by mass of the resin or rubber. A whitening-resistant flame-retardant resin composition comprising 50 to 250 parts by mass of surface-treated magnesium hydroxide of a polyhydric alcohol higher fatty acid ester and 0.05 to 3 parts by mass of a whitening-resistant auxiliary. 2. The whitening-resistant flame-retardant resin composition according to claim 1 , wherein the polyhydric alcohol higher fatty acid ester is a glycerin-stearic acid ester having an esterification rate of 40 to 90%. The whitening-resistant flame-retardant resin composition according to claim 1 or 2 , wherein the resin or rubber is an ethylene resin. An extrusion-molded product obtained by extrusion-molding the whitening-resistant flame-retardant resin composition according to any one of claims 1 to 3 . Claim 1 wires and cables having a coating layer obtained by extruding the whitening resistance flame retardant resin composition according to any one of 3.

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