JPH11172056A - Flame-retardant polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer composition which has a proper degree of adhesiveness to an optical fiber made of a synthetic resin, is excellent in flame retardancy and processability, gives a covering free from surface roughening even in high-speed covering, and does not suffer whitening on bending. SOLUTION: This composition is obtained by compounding 100 pts.wt. total of polymer components comprising (A) 10-40 pts.wt. ethylene/(meth)acrylic ester copolymer having a (meth)acrylic ester content of 5-30 wt.% and an MFR [melt flow rate (at 190 deg.C under a load of 2,160 g, the same applies hereinafter)] of 1-50 g/10 min, (B) 80-30 pts.wt. copolymer of ethylene with a 5C or higher olefin, made by single site catalytic polymerization and having a density of 0.885-0.915 g/cm<3> and an MFR of 1-20 g/10 min, and (C) 5-50 pts.wt. lowly crystalline ethylene/1-butene copolymer having a density of 0.870-0.890 g/cm<3> and an MFR of 1-20 g/10 min with (D) 150-250 pts.wt. flame retardant comprising a metal hydroxide, and (E) 5-50 pts.wt. red phosphorus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a highly flame-retardant polymer composition having excellent processability and mechanical properties. More specifically, the present invention relates to a flame-retardant polymer composition exhibiting good coating properties on optical fibers made of synthetic resin.

[0002]

2. Description of the Related Art A coating material for an optical fiber made of a synthetic resin such as polymethyl methacrylate is required to be flame-retardant in order to prevent a fire. There is a demand for a polymer for a coating material which is provided with flame retardancy without using a flame retardant containing halogen so as not to generate poisonous gas, and which exhibits appropriate adhesion to a core wire.

In order to meet this demand, the present inventors have already disclosed in Japanese Patent Application Laid-Open No. 7-70382 a highly flame-retardant polymer composition which is suitable as an optical fiber sheath material and which has excellent workability and mechanical properties. I made a proposal. According to the proposal, a specific ethylene / (meth) acrylate copolymer having a low melt flow rate (MFR) and a specific low-crystalline ethylene / higher olefin copolymer are used as a base polymer, and a metal hydroxide is added thereto. A predetermined amount of the flame retardant and red phosphorus was blended. Although this proposal achieved moderate core wire adhesion, excellent workability, and flame retardancy, further improvement in performance was demanded due to a demand for higher speed coating processing. That is, in this proposal, if the aim is to further improve the flame retardancy, the workability may inevitably be sacrificed.

[0004]

Accordingly, the present inventors have conducted extensive studies on polymers and flame retardants to be used with the aim of further improving the performance. As a result, it has been found that a desired performance can be obtained by performing the following formulation. Accordingly, an object of the present invention is to provide a suitable coating to a synthetic resin optical fiber, exhibit excellent flame retardancy and processability, and provide a coating without surface roughness even when high-speed coating is performed. An object of the present invention is to provide a flame-retardant polymer composition which does not cause deterioration in appearance such as whitening even when bent to the extent that performance is not impaired.

[0005]

According to the present invention, a (meth) acrylate content is 5 to 30% by weight, and a melt flow rate (190 ° C., 2160 g load, the same applies hereinafter) is 1 to 5%.
10 to 40 parts by weight of ethylene / (meth) acrylate copolymer (A) having a density of 0.88
5 to 0.915 g / cm ³ , melt flow rate is 1 to
80 to 30 parts by weight of a copolymer (B) of ethylene and a higher olefin having 5 or more carbon atoms produced with a single-site catalyst having a density of 20 g / 10 min and a density of 0.870 to 0.
890 g / cm ³ , melt flow rate 1-20 g /
10 minutes low crystalline ethylene / 1-butene copolymer (C)
It is difficult to mix 150 to 250 parts by weight of a metal hydroxide flame retardant (D) and 5 to 50 parts by weight of red phosphorus (E) with respect to 100 parts by weight of a total of 5 to 50 parts by weight of a polymer component. The present invention relates to a flammable polymer composition.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Ethylene used in the present invention
The (meth) acrylate copolymer (A) has a (meth) acrylate content of 5 to 30% by weight, preferably 10 to 20% by weight, and a melt flow rate of 1 to 50%.
g / 10 minutes, preferably 3 to 30 g / 10 minutes. It is not preferable to use a copolymer (A) having a (meth) acrylate content less than the above range because the adhesiveness to the synthetic resin optical fiber becomes too small, and conversely, a copolymer having a too large content is used. In this case, disadvantages such as an excessive increase in the adhesive strength to the optical fiber or a decrease in the strength of the composition become unfavorable. Further, when the melt flow rate of the copolymer is smaller than the above range,
When the coating process is performed, it becomes difficult to obtain a clean coating of the surface skin, and when a copolymer having a melt viscosity smaller than the above range is used, it is preferable since it adversely affects mechanical strength and flame retardancy. Absent.

Here, the (meth) acrylate means acrylate or methacrylate, and specifically, methyl acrylate, ethyl acrylate, isobutyl acrylate, nbutyl acrylate, Representative examples include methyl methacrylate and isobutyl methacrylate.

The copolymer (B) used in the present invention is a copolymer of ethylene and a higher olefin having 5 or more carbon atoms produced by a single-site catalyst, and has a density of 0.88.
5 to 0.915 g / cm ³ , preferably 0.890 to
0.910 g / cm ³ , melt flow rate is 1 to 20
g / 10 minutes, preferably 2 to 15 g / 10 minutes.

The single-site catalyst is a polymerization catalyst having a single active site, also called a metallocene catalyst or a Kaminsky catalyst, and a typical example is a catalyst system comprising bis (indenyl) zirconium dichlorite and methylaluminoxane. A catalyst comprising a cyclopentadienyl or indenyl coordination transition metal compound and an aluminoxane catalyst, or a catalyst using cyclopentadienyl or indenyl coordination rare earth metal compound or an organometallic compound, and such a catalyst system is It is already widely known.

The higher olefin constituting the copolymer (B) is 1-pentene, 1-hexene, 1-octene, 1-octene,
It has 5 or more carbon atoms, preferably 6 to 10 carbon atoms, such as decene and 4-methyl-1-pentene. The composition of the copolymer varies depending on the type of the higher olefin which is a copolymer component, but 70 to 95% by weight of ethylene, especially 75 to 95% by weight.
It is preferable to use those having a polymerization ratio of 5 to 30% by weight, particularly 10 to 25% by weight, with respect to 90% by weight.

The copolymer of ethylene and higher olefins produced with such a single-site catalyst has the characteristic that the molecular weight distribution and the composition distribution are narrow, and such a copolymer is blended as an essential component. By doing
A flame-retardant composition having relatively large elongation and hardly causing cracking or whitening due to bending or the like can be obtained. When a copolymer of a higher olefin having 4 or less carbon atoms is used here, it becomes difficult to obtain a polymer composition having excellent flame retardancy and processability.

When a copolymer having a density or a melt flow rate smaller than the above range is used, it is difficult to obtain a composition having good processability, and when a copolymer having a density higher than the above range is used. If a large amount of flame retardant is added, the physical properties and processability of the composition will be impaired. On the other hand, if the copolymer (B) has a melt flow rate higher than the above range, the mechanical strength and the flame retardancy of the composition are undesirably impaired.

In the present invention, the copolymer (A) and the copolymer (B) are used as the polymer components constituting the polymer composition.
In addition, the density is 0.870-0.890 g / 10
The low crystalline ethylene / 1-butene copolymer (C) having a melt flow rate of 1 to 20 g / 10 min, preferably 2 to 15 g / 10 min is used. Such a copolymer (C) is obtained by copolymerizing ethylene and 1-butene in the presence of a catalyst comprising a vanadium compound such as vanadium oxytrichloride or vanadium tetrachloride and an organoaluminum compound, or the above-mentioned single-site catalyst. It can be produced by polymerization. Here, low crystallinity means that the crystallinity based on X-ray diffraction is 3 to 20%, preferably 5 to 15%.
Say something about.

The amounts of the copolymers (A), (B) and (C) slightly vary depending on the copolymer composition.
When the total amount is 100 parts by weight, the copolymer (A) is 10 to 40 parts by weight, preferably 15 to 35 parts by weight, and the copolymer (B) is 80 to 30 parts by weight, preferably 70 to 40 parts by weight, the copolymer (C) is 5 to 50 parts by weight, preferably 10 to 40 parts by weight. When the amount of the copolymer (A) is less than the above range, the adhesiveness to the optical fiber is insufficient. On the other hand, when the amount is too large, the flame retardancy is adversely affected or the adhesive force to the optical fiber is strong. Difficulties, such as becoming too much, arise. The copolymer (B) has the flame retardancy of the composition,
The copolymer (C) plays an important role in imparting properties such as workability and mechanical strength, and the copolymer (C) is important in preventing bending whitening. The smoothness will be adversely affected.

Examples of the metal hydroxide flame retardant (D) that can be used in the present invention include magnesium hydroxide, basic magnesium carbonate, hydrotalcite, and aluminum hydroxide. These are fatty acids,
It may be one that has been surface-treated with a fatty acid metal salt, a silane coupling agent, a titanate coupling agent, or the like. Generally, the use of such a surface-treated product is more effective in improving the processability and mechanical properties of the composition.

In the present invention, red phosphorus (E) is used together with the inorganic hydroxide flame retardant (D). As red phosphorus, the particle diameter is 50 μm or less, preferably 1 to 10 μm.
It is preferable to use those having a diameter of m or less and exhibiting a spherical shape. Further, the red phosphorus may be mixed with a material such as aluminum hydroxide. Even when red phosphorus is used as such a composition, it is preferable to use the one having the above-mentioned particle diameter of red phosphorus itself. In other words, when a particle having an excessively large particle size is used, in order to obtain a highly flame-retarded polymer composition, it is necessary to use a large amount of the polymer composition, and if the shape is not adjusted. This is because it becomes difficult to obtain a molded product having excellent surface texture. As such a red phosphorus having a small particle size and suitable for the present invention, for example, Nova Excel F-5 of Rin Kagaku can be exemplified.

The amount of the inorganic hydroxide flame retardant (D) used is 150 to 250 parts, preferably 150 to 200 parts by weight, per 100 parts by weight of the polymer component. If the amount of the flame retardant is too small, sufficient flame retardancy cannot be achieved, and if the amount is too large, a composition having excellent processability cannot be obtained.

The amount of red phosphorus used is 5 to 50 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the polymer component. If the amount of red phosphorus used is too small, the flame retardancy is insufficient, while if the amount is too large, the processability and mechanical properties of the composition are not only poor, but also disadvantageous in cost, which is not preferable.

The polymer composition of the present invention contains (A), (B) and (B) as long as the object of the present invention is not impaired.
In addition to the components (C), (D) and (E), small amounts of other polymers and additives can be blended. For example, antioxidants,
A weather stabilizer, a light stabilizer, an ultraviolet absorber, a pigment, carbon black, calcium oxide, titanium oxide, calcium carbonate, zinc oxide, silicone oil and the like can be blended.

[0020]

Industrial Applicability The flame-retardant polymer composition of the present invention has excellent flame retardancy, mechanical properties, and processability. A coating having properties excellent in whitening resistance can be formed. It has an appropriate adhesive property to optical fibers made of synthetic resin, especially optical fibers made of polymethyl methacrylate, making it an excellent coating material, but has the advantage that it can be easily peeled off when the coating is peeled off at the end processing. I have.

[0021]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. The composition and physical properties of each polymer constituting the polymer compositions of Examples and Comparative Examples are as follows.

Component (A): All ethylene / ethyl acrylate copolymer

[Table 1]

Component (B): All linear ethylene-1
-Methylpentene copolymer

[Table 2]

Component (C) EBR: ethylene / 1-butene copolymer MFR 3.6 g / 10 min, density 885 kg / m ³

(D) Component Magnesium hydroxide: "Kisuma 5" manufactured by Kyowa Chemical Co., Ltd.
B "

Component (E): Red phosphorus-based flame retardant “Novaquer FST-100” manufactured by Rin Kagaku Co., Ltd.
(A mixture of “NOVA EXCEL 120UFA” and aluminum hydroxide, red phosphorus content: 45 to 50%) “NOVAQUEL F5” manufactured by Rin Kagaku Co., Ltd. (a mixture of “NOVA EXCEL F5” and aluminum hydroxide, red phosphorus content) 45-50%)

Other components: carbon black 44B manufactured by Mitsubishi Chemical Corporation

The method for evaluating the physical properties of the obtained polymer composition is as follows. (1) Melt flow rate Temperature 190 ° C, load 216 according to JIS K6760
It was measured at 0 g and used as an index of workability.

(2) Tensile Properties The composition was formed into a 1 mm-thick press sheet by press molding, and was used as a No. 3 test piece of JIS K6301 according to JIS K.
The tensile strength and elongation were measured according to 6760.

(3) Surface Hardness The composition was formed into a 3 mm-thick press sheet by press molding, and the Shore D hardness was measured in accordance with JIS K7215, and the scratch resistance of the surface was determined from the numerical values in the following two stages. Suitable: Hard to scratch (Shore D hardness 44 or more). Bad: Scratch is more likely than the above (Shore D hardness less than 43).

(4) Low-Temperature Brittleness The composition was pressed into a 2 mm-thick press sheet, measured according to JIS K6760, and judged as follows. ：: 50% destruction temperature is -21 ° C or less △: 50% destruction temperature is -15 ° C to -20 ° C ×: 50% destruction temperature is -14 ° C or more

(5) Flame retardancy A strand having an outer diameter of about 2 mm is prepared using a melt indexer for measuring a melt flow rate, and the UL standard VW
-1 Evaluated according to the vertical combustion test.

(6) Adhesion force with optical fiber core wire made of synthetic resin The circumference of Esca Extra (EK-40 1 mm outer diameter) manufactured by Mitsubishi Rayon Co., Ltd. was formed at a molding temperature of 160 ° C. and an outer circumference of 2.2 mm.
Coating the composition so as to observe the peelability of the coating,
The evaluation was as follows. Appropriate: Has moderate adhesion. Excess: The coating cannot be peeled off because the adhesion is too strong. Insufficient: adhesion is too weak.

(7) Surface Smoothness The surface condition of the composition coated on the fiber wire was observed by the above method, and evaluated by the following three grades. ：: The coating surface is smooth and glossy. Δ: The coated surface is tentatively smooth, but has little gloss. X: The coating surface is rough and whitish.

(8) Bending Whitening Resistance The state of the coated surface when the above-mentioned coated fiber wire was spirally wound around a steel wire having a diameter of 3 mm was observed and evaluated as follows. ：: good condition without fine cracks or whitening phenomenon. C: Fine cracks were observed on the surface, but did not lead to whitening. C: Surface cracks are observed and whitening is strongly observed.

Examples 1 to 8 Ethylene / ethyl acrylate copolymer (EEA or EEA) as ethylene / (meth) acrylate copolymer (A) and single-site catalyst as ethylene polymer (B) Using linear polyethylene (LLDPE) produced by the above, low crystalline ethylene / 1-butene copolymer as component (C), magnesium hydroxide as metal hydroxide flame retardant (D), red phosphorus Using a mixture of red phosphorus and aluminum hydroxide (red phosphorus-based flame retardant or) as a flame-retardant auxiliary (E), kneading with a TEX44 twin-screw extruder at the compounding ratio shown in Table 1, and then further rolled to a 6-inch roll It was charged and masticated to produce a fractionated sheet of the flame-retardant polymer composition.

Tables 3 and 4 show the evaluation results of the physical properties of the obtained flame-retardant polymer composition. The flame-retardant polymer composition obtained according to the present invention exhibits the same level of flame-retardancy as compared with conventional flame-retardant compositions, has excellent low-temperature brittleness and surface scratch resistance, has sufficient elongation, and is flexible. The properties were good. In particular, the skin on the resin surface of the fiber coating was good.

[Comparative Examples 1-2] EE was used as the component (A).
EEA with low MFR instead of A or EEA
And LLDPE polymerized by using a conventional Ziegler-Natta catalyst instead of LLDPE as the component (B).
Was used to prepare flame-retardant polymer compositions in the proportions shown in Table 2 in the same manner as in the examples, and the physical properties were evaluated in the same manner as in the examples.
Table 5 shows the results. The surface smoothness and bending whitening resistance were poor, the surface hardness was low, and the scratch resistance was insufficient.

Comparative Example 3 EEA was used as the component (A).
Alternatively, instead of EEA, EEA with low MFR
And a flame-retardant polymer composition was prepared in the same manner as in the examples by using LLDPE polymerized by using a conventional Ziegler-Natta catalyst instead of LLDPE as the component (B), in the same manner as in the examples. Physical properties were evaluated in the same manner as described above. Table 5 shows the results. The surface smoothness and bending whitening resistance were poor.

[Comparative Examples 4 to 8] LLD as the component (B)
A flame-retardant polymer composition was prepared in the same manner as in the examples by using LLDPE polymerized by using a conventional Ziegler-Natta catalyst in place of PE, and the physical properties were evaluated in the same manner as in the examples. The results are shown in Tables 5 to 7. All of them have poor surface smoothness and insufficient surface scratch resistance. In Comparative Examples 4 and 5, the bending whitening resistance was poor. Further, in Comparative Examples 7 and 8, the elongation is insufficient.

Comparative Example 9 A flame-retardant polymer composition was prepared in the same manner as in Comparative Example 8 except that a red phosphorus-based flame retardant was used instead of the red phosphorus-based flame retardant. Physical properties were evaluated in the same manner as in the examples. Table 7 shows the results. The bending whitening resistance was insufficient, and the elongation was poor.

[Comparative Examples 10 to 11] The low-crystalline ethylene / 1-butene copolymer of the component (C) was not blended, and only the polymer components (A) and (B) were used. Flame-retardant polymer compositions were prepared in the same proportions as in the examples, and the physical properties were evaluated in the same manner as in the examples. Table 7 shows the results. The bending whitening resistance and elongation were poor, and in Comparative Example 10, the smoothness was also poor.

Comparative Example 12 The ethylene / higher olefin copolymer produced with the single-site catalyst of the component (B) was not blended, and the polymer component contained 50 parts by weight of the component (A). C) A flame-retardant polymer composition was prepared in the same manner as in the example except that only two components were used, and the physical properties were evaluated in the same manner as in the example. Table 8 shows the results. The adhesion to the core wire is too strong to remove the coating. Also, the surface scratch resistance was insufficient.

Comparative Example 13 The low-crystalline ethylene / 1-butene copolymer of the component (C) was not blended, and the polymer component contained 50 parts by weight of the component (A). A flame-retardant polymer composition was prepared in the same manner as in the examples except that only the components were used, and the physical properties were evaluated in the same manner as in the examples. Table 8 shows the results. Adhesion with core wire is too strong.

[Comparative Example 14] The ethylene / ethyl acrylate copolymer of the component (A) was not blended, and only the polymer components (B) and (C) were used in the proportions shown in Table 2 with only the two components. A flame-retardant polymer composition was prepared in the same manner as in Example 1, and the physical properties were evaluated in the same manner as in Examples. Table 8 shows the results. The adhesion to the core wire was insufficient.

[0046]

[Table 3]

[0047]

[Table 4]

[0048]

[Table 5]

[0049]

[Table 6]

[0050]

[Table 7]

[0051]

[Table 8]

Claims (2)

[Claims] (1) a (meth) acrylate content of 5 to 5
30% by weight, melt flow rate (190 ° C., 2160
g load, the same applies hereinafter) of 1 to 50 g / 10 min.
40 parts by weight, density 0.885 to 0.915 g / cm
^3. 80 to 30 parts by weight of a copolymer (B) of ethylene and a higher olefin having 5 or more carbon atoms produced by a single-site catalyst having a melt flow rate of 1 to 20 g / 10 min, and a density of 0.870 ~0.890g / cm ^3, the total amount 100 parts by weight of the polymer component melt flow rate is from from 1 to 20 g / 10 min of the low crystalline ethylene-butene copolymer (C) 5 to 50 parts by weight On the other hand, 150 to 250 parts by weight of metal hydroxide flame retardant (D) and red phosphorus (E)
A flame-retardant polymer composition comprising 5 to 50 parts by weight. 2. The flame-retardant polymer composition according to claim 1, wherein the red phosphorus (E) is a spherical particle having a particle diameter of 10 μm or less.