JPS6357458B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention particularly relates to a highly inorganic-filled polyolefin resin composition that has excellent tensile elongation properties. As is well known, polyolefin resins have excellent various properties and are therefore used in large quantities for a wide range of applications. In recent years, attempts have been made to fill this polyolefin resin with various inorganic substances for the purpose of making it non-polluting, flame retardant, and conserving resources. For example, taking aluminum hydroxide as an example, by filling the hydrate, water of crystallization is removed from the hydrate at a specific high temperature, thereby improving the flame retardancy of the composition and self-extinguishing. It is cheaper than flame retardant compositions made by adding so-called halogen flame retardants, does not generate toxic gas when burned, increases safety for various equipment and the human body, and does not deteriorate various electrical properties. It has excellent features and has high expectations. However, it is not always easy to highly fill a polyolefin resin with various inorganic substances because of the poor dispersibility and compatibility of the inorganic substances in the resin. Even if it is possible to blend and fill the resin with more than 100 phr of inorganic material by using special kneading equipment, the resulting composition has various physical properties such as a significant decrease in tensile elongation at break. It has been extremely difficult to obtain a composition that has practical performance without a significant decrease in . As a means to improve these drawbacks, the use of so-called coupling agents has generally been proposed to modify the surface of inorganic substances. Silane-based coupling agents and titanate-based coupling agents are well-known as such coupling agents, but although the former can treat the surface of silicate-based inorganic substances, it has no reactivity with other inorganic substances, and furthermore, this The results of the inventor's study revealed that there is no effect of improving the tensile elongation at break by increasing the rigidity of the composition. Furthermore, although the latter may have the effect of increasing elongation at break, it is very expensive. In addition, as a known document, for example, Japanese Patent Publication No. 101049/1984 is recognized, but even in this case, although it is recognized that the impact strength of the composition obtained is improved, the effect of improving extensibility is not expected. It is something that cannot be done. The present inventors have arrived at the present invention as a result of extensive research into methods for improving the tensile properties, particularly the elongation at break properties, of inorganic-rich polyolefin resin compositions. That is, the present invention provides a polyolefin resin composition containing a large amount of inorganic compound powder, which further contains at least one divalent phenol selected from the group of catechol, resorcinol, and hydroquinone derivatives having a saturated or unsaturated hydrocarbon group. This is an inorganic-highly filled polyolefin composition having particularly improved tensile elongation properties, characterized in that the compound is contained in a proportion of 3 to 20 parts by weight per 100 parts by weight of the inorganic compound powder in the composition. A feature of the present invention is that at least one divalent phenol compound selected from the group of catechol, resorcinol, and hydroquinone derivatives having a saturated or unsaturated hydrocarbon group is used as an additive. Although the mechanism of action of the divalent phenol compound in the composition of the present invention is not yet clear, by adding it to a polyolefin resin composition containing a large amount of inorganic powder, the OH group in the divalent phenol compound can be It is presumed that while hydrogen bonds are formed with the surface of the inorganic compound, the hydrocarbon groups in the compound maintain affinity with the polyolefin resin, acting as a kind of coupling agent or inorganic surface treatment agent. As a result, the tensile properties of a composition containing an inorganic powder are greatly improved, and in particular, it is characterized by a remarkable effect of increasing the breaking strength (tensile strength) as well as improving the elongation at break. Examples of the derivatives of catechol, resorcinol, and hydroquinone having a saturated or unsaturated hydrocarbon group in the present invention include the following. Examples of catechols include p-tert-butylcatechol, urushiol, latcol, thithiol, and "Ureshisol" (product of Saito Co., Ltd.). Examples of resorcin compounds include 4-n-hexylresorcin and 4-tert-octylresorcin. In addition, as a hydroquinone compound, 2,5-
Di-tert-butylhydroquinone, 2,5-di-
tert-amylhydroquinone, etc. The present invention is limited to these divalent phenols having a saturated or unsaturated hydrocarbon group because the desired effect can be obtained. Monovalent phenols and benzene-based compounds are excluded from the present invention because they do not exhibit the desired effect as shown in the comparative example below, although the reason is unknown. If the amount of the divalent phenol compound used in the present invention is less than 3 parts by weight per 100 parts by weight of the inorganic powder in the composition, the desired effect will be insufficient;
If the amount exceeds 3 parts by weight, the inherent properties of the polymer will be impaired, so a range of 3 to 20 parts by weight is preferred. Moreover, there is no problem in using two or more of the above divalent phenols in combination. The polyolefin resin in the present invention includes, for example, low-density, medium-density and high-density polyethylene,
Homopolymers of olefins such as polypropylene and polybutene-1; ethylene including ethylene-vinyl acetate copolymers, ethylene-vinyl acetate-vinyl chloride copolymers, ethylene-ethyl acrylate copolymers, and ethylene-propylene copolymers -Ethylene copolymers such as α-olefin copolymers; ethylene-propylene rubber, ethylene-
It is an olefin-based elastomer such as a propylene-diene-based compound. These resins and elastomers can be used as a mixture of two or more, or as a mixture of these resins and elastomers with other resins and elastomers. Among them,
Since the effects of the present invention are exhibited when an ethylene-vinyl acetate copolymer and a blend polymer system thereof are used, it is preferable to use an ethylene-vinyl acetate copolymer. As the inorganic compound in the present invention, aluminum hydroxide, zinc borate, magnesium hydroxide, calcium hydroxide, etc. are preferably used. These inorganic compounds usually have an average particle size of 0.01~
It is used in powder form of 30μ, preferably 0.05 to 10μ. The amount added is 30 to 300 parts by weight, preferably 50 to 200 parts by weight, per 100 parts by weight of the polyolefin resin. The composition of the present invention generally includes various additives that can be added to the resin, such as a crosslinking agent such as dicumyl peroxide, a crosslinking aid such as trimethylolpropane-trimethacrylate, a blowing agent such as azodicarbonamide, and a Flame retardants such as bromodiphenyl oxide, flame retardant aids such as antimony trioxide, lubricants such as zinc stearate, 4,4'-thiobis(6-
Anti-aging agents such as tert-butyl-3-methylphenol), 3-(N-salicyloyl)amino-1,
Metal deterioration inhibitors such as 2,4-triazole, carbon black, coloring agents, etc. can be added as necessary. It is also possible to crosslink the composition of the present invention by irradiation with electron beams, gamma rays, ultraviolet rays, etc. The composition of the present invention is used after being kneaded and molded using a two-roll mill, a Banbury machine, an extruder, an injection molding machine, or the like. The divalent phenol compound is usually added during the usual kneading process, but there are also cases where it is pretreated by blending and stirring only with the inorganic powder. The composition of the present invention is a highly inorganic-filled material that retains the tensile properties inherent to polyolefin resin, so it can be used as a coating material for various electric wires and cables, pipes, sheets, etc.
It is used in a wide variety of applications, including various molded products such as films, and foamed products. The performance of the composition of the present invention is shown below in Examples. Examples 1 to 10 Comparative Examples 1 to 5 Commercially available ethylene-vinyl acetate copolymer (Mitsui Polychemical Co., Ltd. product Evaflex EV)
360; Vinyl acetate content 25%, density 0.95g/cm ³ ,
MI2) To 100 parts by weight, 100 parts by weight of commercially available aluminum hydroxide powder (Higilite H-42M, manufactured by Showa Denko K.K.) and predetermined amounts of various surface treatment additives were added, and Brabender Plasticorder was added. After kneading the mixture, it was formed into a sheet with a thickness of 1 mm using a hot press, a No. 3 dumbbell test piece was prepared according to JIS C-3005, and the tensile properties were evaluated using a Tensilon type tensile tester. These results are summarized in Table 1.

[Table] Comparative Example 1 is a comparative example in which no surface treatment additive was used.
Examples 1 and 2 are cases in which 4-n-Hexyl resorcinol (reagent grade) is added, and show that the tensile strength is significantly improved. Examples 3 and 4 are P-tert-Butyl Catechol (reagent grade), and similarly to the above, the tensile strength is significantly improved. Examples 5 and 6 use "Ursisol N-244" (product of Saito Co., Ltd.), which is commercially available as synthetic urushiol, and Examples 7 and 8 use "urushiol" obtained from natural sumac. This is an example.
Examples 9 and 10 are 2,5-di-tert-
Butyl hydroquinone and 4-tert-Octyl
This is the result when resorcinol was added. These Examples show a significant improvement in tensile strength compared to the Comparative Examples. Examples 11-12 Comparative Example 6 In this example, the composition and the results obtained are as shown in Table 2 when the amount of aluminum hydroxide powder added in Example 1 was 150 phr. In Examples 11 and 12, the above-mentioned "Ursizol" and 4-n-Hexylresorcinol were added, respectively, but the elongation and tensile strength were significantly improved compared to Comparative Example 6, which did not use any additives.

[Table] Example 13 Comparative Examples 7 to 9 Water was added to 100 parts by weight of ethylene-vinyl acetate copolymer (Mitsui Polychemical Co., Ltd. product, Evaflex ⁴⁶⁰ ) with a vinyl acetate content of 19% and a density of 0.94 g/cm3. 100 parts by weight of aluminum oxide powder and various processing additives were blended in predetermined proportions and evaluated in the same manner as in Example 1. The results obtained are shown in Table 3.

【table】

[Table] Example 13 shows 4-n-Hexyl according to the present invention.
This is an example in which resorcinol 3phr was added, and it shows large elongation and high tensile strength. On the other hand, Comparative Example 7 is an example in which no additive is used, and Comparative Examples 8 and 9 are examples in which titanate-based coupling agents (Kenrich
This is a comparative example in which petrochemical product Ken-React TTS) and zinc stearate (reagent grade) were added. It can be seen that all of these are inferior to Ohiba in terms of tensile strength. Examples 14 and 15 Comparative Example 10 Medium density polyethylene with density 0.922g/cm ³ MI0.7 (Mitsui Petrochemical Industries Co., Ltd. product, Neozex
2006H) 100 parts by weight, 80 parts by weight of aluminum hydroxide powder and processing additives were blended at a predetermined ratio and evaluated in the same manner as in Example 1. The results obtained are shown in Table 4.

[Table] Examples 14 and 15 are 4-n-Hexyl resorcinol
This is an example of the present invention in which 3 phr and 5 phr were added,
It is shown that the elongation and tensile strength greatly improve with the amount of additive added. On the other hand, Comparative Example 10 is an example in which no additives are used. In this case, it can be seen that both elongation and tensile strength are inferior to the width. As is clear from the above examples, the composition of the present invention has excellent physical properties despite being highly loaded with inorganic substances, and its practical value is extremely large.

Claims (1)

[Claims] 1. 30 to 300 parts by weight of at least one inorganic compound powder selected from the group of aluminum hydroxide, zinc borate, magnesium hydroxide, and calcium hydroxide per 100 parts by weight of the polyolefin resin; Catechol, resorcinol, and hydroquinone having a saturated or unsaturated hydrocarbon group based on 100 parts by weight of the inorganic compound in the composition, which contains an anti-aging agent and various other additives as necessary. 1. An inorganic-filled polyolefin resin composition comprising 3 to 20 parts by weight of at least one divalent phenol compound selected from the group of derivatives. 2. The inorganic-filled polyolefin resin composition according to claim 1, wherein the polyolefin resin is an ethylene-vinyl acetate copolymer.