JP3431944B2 - Flame retardant polyolefin resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant polyolefin resin composition which has excellent flame-retardant performance and does not generate corrosive gas during combustion. is there. [0002] A large number of plastic materials which are required to be flame-retardant, such as insulating materials for electric wires and cables, enclosures for electric and electronic equipment, materials for railway vehicles, automobiles, and materials for construction. However, the required flame retardant performance is also increasing. Conventionally, as a technique for imparting flame retardancy to these plastic materials, a method of blending a halogen-based flame retardant has been mainly used. As another method, a method of blending a hydrated metal compound such as magnesium hydroxide or aluminum hydroxide is known. However, those containing a halogen-based flame retardant are problematic in that they emit a large amount of smoke during combustion and generate corrosive gases such as hydrogen halide. That is, a resin composition containing a halogen-based flame retardant, damage to equipment and devices caused by corrosive gas generated during combustion,
People evacuating in the event of a fire may lose their way out due to smoke. In recent years, hydrated metal compounds such as magnesium hydroxide and aluminum hydroxide have been used as substitutes for halogen-based flame retardants in recent years, because smoke emission as described above is suppressed and corrosive gas is not generated by itself. Increasing. However, since these hydrated metal compounds require a large amount of compounding to sufficiently impart flame retardancy, the mechanical properties of the resin composition are significantly reduced, and the specific gravity of the resin composition is increased. One of the features of polymer materials is that they are light and strong.However, hydrated metal compounds greatly impair such features, making it a state that cannot be said to be a satisfactory flame retardant method. Met. [0004] In recent years, attempts have been made to blend red phosphorus. However, since the flame retardancy obtained by blending red phosphorus alone is insufficient, red phosphorus and Attempts have been made to mix them together with a hydrated metal compound, and to mix heat-expandable graphite with red phosphorus and a hydrated metal compound for the purpose of further imparting flame retardancy. However, in the conventional technology, the blending of a hydrated metal compound is indispensable for flame retardancy by a non-halogen system, and the mechanical properties of the resin composition are reduced and the specific gravity of the resin composition is increased. It is. [0005] Under such circumstances, the present inventors have developed a polyolefin-based resin composition.
And heating expandable graphite having a waxy and specific particle shape particular expandable, issued Mii to exert a significant flame retardant effect by blending a phosphorus compound, the present invention described in the scope of the appended claims Reached. The polyolefin resin used in the present invention includes olefin monomers such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, polybutene-1, polyisobutylene and poly-4-methyl-1-pentene. Homopolymers, ethylene-acrylic acid, ethylene-ethyl acrylate, ethylene-methyl acrylate, ethylene-acrylamide, ethylene-methacrylic acid, ethylene-methyl methacrylate, ethylene-glycidyl methacrylate, ethylene-maleic anhydride, And ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-propylene-
Examples thereof include a diene compound copolymer, a copolymer containing an olefin monomer such as an ionomer resin, or a mixture of two or more of these. The phosphorus compounds used in the present invention are exemplified below. The term “phosphoric acid” as used herein includes all of phosphoric acid, phosphorous acid and hypophosphorous acid. Examples of the phosphorus compound used in the present invention include triphenyl phosphate, octyl diphenyl phosphate, trioctyl phosphate, tricresyl phosphate, phosphate esters such as dibutyl hydrogen diene phosphate, and sodium phosphate, potassium phosphate, magnesium phosphate, calcium phosphate, Metal salts of phosphoric acid such as zinc phosphate and aluminum phosphate, and hydrates of those metal salts, ammonium phosphate, ammonium polyphosphate, phosphates of ethylenediamine, salts of phosphoric acid such as diethylenetriamine phosphate and salts of ammonia or amines, and Examples thereof include condensates thereof, guanidine phosphate, phosphine and phosphine oxide, melamine-modified ammonium polyphosphate, and a mixture of two or more of these phosphorus compounds. In the case of a phosphoric acid ester, a salt of phosphoric acid and ammonia or an amine, or a condensate thereof, the amount of the phosphorus compound is preferably 1 to 30 parts by weight based on 100 parts by weight of the polyolefin resin.
If the amount is less than 1 part by weight, the flame retarding effect is insufficient, and if it exceeds 30 parts by weight, the hygroscopicity of the resin composition becomes high. When the phosphorus compound is a metal phosphate and / or a hydrate of the metal salt, the amount of the phosphorus compound is preferably 1 to 150 parts by weight based on 100 parts by weight of the polyolefin resin. 1
If the amount is less than part by weight, the flame retarding effect is insufficient, and if it exceeds 150 parts by weight, the mechanical properties of the resin composition are greatly impaired. Further, among the phosphorus compounds, those having a melting point equal to or higher than the resin kneading temperature preferably have a particle diameter of 2 μm or less in view of the dispersibility in the resin and the effect on the mechanical properties of the resin composition. Further, it is preferable to use one that has been surface-treated with a silane coupling agent, a titanate coupling agent, a fatty acid, or the like. [0009] The heat-expandable graphite used in the present invention has an expandability of 100 times or more in the C-axis direction (direction perpendicular to the cleavage plane of graphite) when rapidly heated (800 to 1000 ° C). is necessary. This is because those having no expansion property of 100 times or more have much lower flame retardancy than those having expansion properties of 100 times or more. The expandability in the present invention means the difference between the specific volume (ml / g) after heating and the specific volume at room temperature. A method for measuring the swelling property will be specifically described. In a quartz beaker heated to 1000 ° C. in advance in an electric furnace, 2 g of the heat-expandable graphite is charged, and quickly added to 10 g.
A quartz beaker is placed in an electric furnace heated to 00 ° C. for 10 seconds, taken out of the furnace, and allowed to cool to room temperature. Thereafter, the weight of the expanded graphite (100 ml) was weighed, the loose apparent specific gravity (g / ml) was measured, and the specific volume was set to 1 / the loose apparent specific gravity. Next, the specific volume of the heat-expandable graphite at room temperature, which was not heated, was determined by the same method, and the expandability was determined as the specific volume after heating minus the specific volume at room temperature. When the heat-expandable graphite before and after expansion was observed with an electron microscope, it hardly expanded in the A-axis direction and the B-axis direction, and expansion was observed only in the C-axis direction. The difference from the specific volume at room temperature was defined as the expandability in the C-axis direction. 80% mesh size 80% by classification
It is necessary to be at least 80% and at most 99%. 80% mesh 80%
If it is less than 100%, the flame retardancy is insufficient, and if it exceeds 99%, the shape retention performance of the resin composition when exposed to a flame tends to slightly decrease, which is not preferred. Preferred examples of the heat-expandable graphite include those obtained by oxidizing flaky graphite. Preferred examples of the oxidation treatment include:
There are oxidation treatments such as electrolytic oxidation in sulfuric acid, and mixed acid of phosphoric acid and nitric acid, sulfuric acid and nitric acid, and perchloric acid. The compounding amount of the heat-expandable graphite must be 1 to 30 parts by weight based on 100 parts by weight of the polyolefin. If the amount is less than 1 part by weight, the flame retarding effect is insufficient, and if it exceeds 30 parts by weight, the mechanical properties of the resin composition are greatly impaired. Other flame retardants can be used in combination with the resin composition of the present invention as long as the effects of the present invention are not impaired. In addition, various additives such as an inorganic filler, a colorant, an antioxidant, and the like can be added as needed. EXAMPLES Hereinafter, the effects of the present invention will be clarified by showing specific examples, but the present invention is not limited to these examples. [0012] Example 1, 2 ethylene - vinyl acetate copolymer (manufactured by Tosoh Corporation: Ultrathene 630) in 100 parts by weight, triphenylphosphine
(Manufactured by Akzo Japan K.K .: TPP) and heat-expandable graphite (Chuo Kasei K.K .: 80 mesh on 96)
%, Expandability at 1000 ° C .: 210 times) in the amounts shown in Table 1, respectively, and a flame-retardant resin composition was prepared by an extruder. The obtained resin composition was injection molded to prepare a test piece. Mechanical properties were evaluated based on tensile breaking strength and elongation according to JIS K 7113 test method. Moreover, the combustion test evaluated the oxygen index based on the JIS K7201 test method, and the UL-94 combustion test. Table 1 shows the results. Examples 3 and 4 Ethylene-vinyl acetate copolymer 100 used in Example 1
In parts by weight, ammonium polyphosphate (Rin Chemical Industry Co., Ltd.)
(PA-6) and the heat-expandable graphite used in Example 1 were mixed in the amounts shown in Table 1 , respectively, and a flame-retardant resin composition was prepared with an extruder. The flame retardancy of the obtained resin composition was evaluated in the same manner as in Example 1. Table 1 shows the results. Examples 5 and 6 Ethylene-vinyl acetate copolymer 100 used in Example 1
In parts by weight, guanidine phosphate (manufactured by Sanwa Chemical Co., Ltd.):
Apinon-301) and the heat-expandable graphite used in Example 1 were mixed in the amounts shown in Table 1 , respectively, and a flame-retardant resin composition was prepared using an extruder. The flame retardancy of the obtained resin composition was evaluated in the same manner as in Example 1. Table of results
It is shown in FIG. Comparative Example 1 The mechanical properties and flame retardancy of the ethylene-vinyl acetate copolymer used in Example 1 were evaluated in the same manner as in Example 1. Table 2 shows the results. Comparative Example 2 Ethylene-vinyl acetate copolymer 100 used in Example 1
By weight, 15 parts by weight of heat-expandable graphite were blended to prepare a resin composition. The mechanical properties and flame retardancy of the obtained resin composition were evaluated in the same manner as in Example 1. Table 2 shows the results. Comparative Example 3 Ethylene-vinyl acetate copolymer 100 used in Example 1
Parts by weight of magnesium hydroxide (Kyowa Chemical Industry
100 parts by weight of Kisuma 5A (produced by K.K.) and 15 parts by weight of the heat-expandable graphite used in Example 1 were blended to prepare a resin composition. The mechanical properties and flame retardancy of the obtained resin composition were evaluated in the same manner as in Example 1. Table 2 shows the results. Comparative Example 4 Ethylene-vinyl acetate copolymer 100 used in Example 1
The resin composition was prepared by blending 10 parts by weight of the triphenyl phosphate used in Example 1 with respect to parts by weight. The flame retardancy of the obtained resin composition was evaluated in the same manner as in Example 1. Table 3 shows the results. Comparative Example 5 Ethylene-vinyl acetate copolymer 100 used in Example 1
20 parts by weight of the ammonium polyphosphate used in Example 3 was blended with respect to parts by weight to prepare a resin composition. The flame retardancy of the obtained resin composition was evaluated in the same manner as in Example 1. Table 3 shows the results. Comparative Example 6 Ethylene-vinyl acetate copolymer 100 used in Example 1
The guanidine phosphate 20 used in Example 5 was used with respect to parts by weight.
By weight, the resin composition was prepared. The flame retardancy of the obtained resin composition was evaluated in the same manner as in Example 1. Table 3 shows the results. Comparative Example 7 As the heat-expandable graphite, 80 mesh-on content: 70
%, Expandability at 1000 ° C 180 times (Chuo Kasei Co., Ltd.)
The resin composition was prepared in the same manner as in Example 2 except that the resin composition was used, and the flame retardancy was evaluated. Table 3 shows the results. Comparative Example 8 As heat-expandable graphite, 80 mesh-on content: 97
%, Swelling 70 times at 1000 ° C (manufactured by Chuo Chemical Co., Ltd.)
A resin composition was prepared in the same manner as in Example 2 except that the resin composition was used, and the flame retardancy was evaluated. Table 3 shows the results. Comparative Example 9 As heat-expandable graphite, 80 mesh-on content: 70
%, Expandability at 1000 ° C 180 times (Chuo Kasei Co., Ltd.)
The resin composition was prepared in the same manner as in Example 4 except that the resin composition was used, and the flame retardancy was evaluated. Table 3 shows the results. Comparative Example 10 As heat-expandable graphite, 80 mesh-on content: 97
%, Swelling 70 times at 1000 ° C (manufactured by Chuo Kasei Co., Ltd.)
A resin composition was prepared in the same manner as in Example 4 except that the resin composition was used, and the flame retardancy was evaluated. Table 3 shows the results. Comparative Example 11 The heat-expandable graphite was 80 mesh-on content of 70
%, Expandability at 1000 ° C 180 times (Chuo Kasei Co., Ltd.)
The resin composition was adjusted in the same manner as in Example 5 except that the resin composition was used, and the flame retardancy was evaluated. Table 3 shows the results. Comparative Example 12 As heat-expandable graphite, 80 mesh-on content: 97
%, Swelling 70 times at 1000 ° C (manufactured by Chuo Kasei Co., Ltd.)
A resin composition was prepared in the same manner as in Example 5 except that the resin composition was used, and the flame retardancy was evaluated. Table 3 shows the results. [Table 1] [Table 2] [Table 3] As shown in Table 1, the flame retardant E of the present invention was used.
The VA composition exhibited extremely excellent flame retardancy in a UL-94 combustion test, and showed a small increase in specific gravity as compared with the EVA of Comparative Example 1 in Table 3, indicating that the physical properties of the EVA were not significantly reduced. On the other hand, as shown in Comparative Example 2 of Table 2, that using a pressurized heat expandable graphite comparable amount alone, UL-
It turns out that sufficient flame retardancy cannot be obtained in the 94 combustion test . Although the specific Comparative Examples 3 shows the test results of the resin composition using magnesium hydroxide, although sufficient flame retardancy is achieved, greatly increase the specific gravity, EVA also to decrease the elongation
It can be seen that the characteristic is greatly impaired. Also,
As shown in Comparative Examples 4 to 6 in Table 3 , those using the phosphorus compound alone did not have sufficient flame retardancy, and furthermore,
Comparative Examples 7 to 12 show the results of using heat-expandable graphite having an 80 mesh-on content of less than 80% and heat-expandable graphite having an expandability of less than 100 times. Is not achieved. Examples 7 to 12 Low-density polyethylene (manufactured by Tosoh Corporation: Petrocene 20)
3) 100 parts by weight of the phosphorus compound used in Examples 1 to 6
An extruder was prepared by blending the heat-expandable graphite in the amount shown in Table 4.
Thus, a flame-retardant resin composition was prepared. Obtained resin set
The flame retardancy of the product was evaluated in the same manner as in Example 1. result
Are shown in Table 4. Comparative Example 13 The mechanical properties and flame retardancy of the low-density polyethylene used in Example 7 were evaluated in the same manner as in Example 1. Table 5 shows the results. Comparative Example 14 A resin composition was prepared by blending 100 parts by weight of the low-density polyethylene used in Example 7 and 15 parts by weight of heat-expandable graphite. The mechanical properties and flame retardancy of the obtained resin composition were evaluated in the same manner as in Example 1. Table 5 shows the results. Comparative Example 15 100 parts by weight of the magnesium hydroxide used in Comparative Example 3 was added to 100 parts by weight of the low-density polyethylene used in Example 7 . A resin composition was prepared by blending 15 parts by weight of the heat-expandable graphite used in Example 1. The mechanical properties and flame retardancy of the obtained resin composition were evaluated in the same manner as in Example 1. Table 5 shows the results. Comparative Examples 16 to 24 The low-density polyethylene used in Example 7 was used as the polyolefin, and the phosphorus compound and the heat-expandable graphite were blended alone, or the phosphorus compound and the heat-expandability having a low content of 80 mesh-on. The flame retardancy of a resin composition containing graphite and a phosphorus compound and a resin composition containing heat-expandable graphite having low expandability at 1000 ° C. were evaluated. Table 6 shows the results. [Table 4] [Table 5] [Table 6] As shown in Table 4 , the flame retardant L of the present invention
It can be seen that the DPE composition has a small increase in specific gravity and exhibits extremely excellent flame retardancy, as in the case of EVA. Further, as shown in the results of Tables 5 and 6 , it is impossible to obtain a resin composition satisfying both flame retardancy and low specific gravity unless the resin composition of the present invention is used. It turns out that it is possible. Examples 13 to 18 Polypropylene (J7030B, manufactured by Tosoh Corporation) 10
0 parts by weight of the phosphorus compound used in Examples 1 to 6 and heat expansion
Of the graphite in the amount shown in Table 7 and extruder
A flame-retardant resin composition was prepared. Difficulties of the obtained resin composition
Flammability was evaluated in the same manner as in Example 1. Table 7 shows the results
Show. Comparative Example 25 The mechanical properties and flame retardancy of the polypropylene used in Example 13 were evaluated in the same manner as in Example 1. Table 8 shows the results. Comparative Example 26 A resin composition was prepared by blending 100 parts by weight of the polypropylene used in Example 13 and 21 parts by weight of heat-expandable graphite. The mechanical properties and flame retardancy of the obtained resin composition were evaluated in the same manner as in Example 1. Table 8 shows the results. Comparative Example 27 100 parts by weight of the polypropylene used in Example 13 and 100 parts by weight of the magnesium hydroxide used in Comparative Example 3 15 parts by weight of the heat-expandable graphite used in 1 were blended to prepare a resin composition. The mechanical properties and flame retardancy of the obtained resin composition were evaluated in the same manner as in Example 1. Table 8 shows the results. Comparative Examples 28 to 36 The polypropylene used in Example 13 was used as the polyolefin, and the phosphorus compound and the heat-expandable graphite were blended alone, or the heating was performed when the phosphorus compound and the 80 mesh-on content were less than 80%. The flame retardancy of a resin composition containing expandable graphite and a resin composition containing a phosphorus compound and heat-expandable graphite having an expandability of less than 100 times was evaluated. Table 9 shows the results. [Table 7] [Table 8] [Table 9] As shown in Table 7 , the flame retardant P of the present invention
It can be seen that the P resin composition has a small increase in specific gravity and exhibits extremely excellent flame retardancy, as in the case of EVA.
Further, as shown in the results of Tables 8 and 9 , it is impossible to obtain a resin composition that satisfies both flame retardancy and low specific gravity without using the resin composition of the present invention. You can see that. As described above, the flame-retardant resin composition of the present invention exhibits excellent flame-retardant properties while maintaining mechanical properties, is light in weight, and contains no halogen. No corrosive gas is generated at the time, the amount of smoke generated during combustion is suppressed,
Extremely safe.

Continuation of the front page (72) Inventor Shunichi Endo 1063-91, Tanukiana, Oaza, Ina-cho, Tsukuba-gun, Ibaraki Prefecture (72) Inventor Genichiro Ochiai 3-41-8, Ekita, Adachi-ku, Tokyo (56) References JP-A-3 JP-A-41161 (JP, A) JP-A-55-5979 (JP, A) JP-A-58-67737 (JP, A) JP-A-60-101129 (JP, A) Augmented new edition 62-69 (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 23/00-23/36 C08K 3/00-13 / 08

Claims (1)

(57) [Claims 1] The swelling property of 100 parts by weight of polyolefin when rapidly heated (800 to 1000 ° C.) is 100 times or more in the C-axis direction, and depends on the classification. 80
The heat-expandable graphite having a mesh-on of 80% or more is 1 to
A flame-retardant polyolefin resin composition comprising 30 parts by weight and a phosphorus compound.