JP4889626B2 - Polypropylene resin self-extinguishing composition and molded article comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a highly self-extinguishable thermoplastic resin material for molded items that is free from fears of generation of toxic gases on incineration even when a large amount of an inorganic flame-retardant is compounded, has excellent tensile properties and exhibits enhanced whitening resistance against external force as well as good molding properties and the like. <P>SOLUTION: The self-extinguishable polypropylene resin composition for molded items comprises 100 pts.wt. of a propylene-ethylene copolymer component (A) satisfying requirements (i)-(ii) and 50-300 pts.wt. of a metal hydrate component (B). (i) A glass transition peak, observed within the temperature range of -60&deg;C to 20&deg;C in the temperature-loss tangent curve by the solid viscoelasticity measurement, is single and the peak temperature is 0&deg;C or lower. (ii) Specific requirements (ii-A) to (ii-C) (not shown) are satisfied in the TREF elution curve obtained as a plot of an elution amount versus the temperature by the temperature-rising elution fractionation method within the temperature range of -15&deg;C to 140&deg;C using an o-dichlorobenzene solvent. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

The present invention relates to a polypropylene resin self-extinguishing composition and a molded body comprising the same,
Specifically, a self-extinguishing (flame retardant) resin composition having a specific propylene-ethylene copolymer and an inorganic flame retardant as components and excellent in mechanical properties and whitening resistance, and the like are coated. It relates to molded products such as molded products.

Since plastic materials that are heavily used as industrial main materials are generally flammable, there has been a strong demand for flame retardant for safety in the use of molded products.
Among the plastic materials, flame retardants for highly versatile thermoplastic resins (and elastomers) can be classified roughly by adopting techniques based on flame retarding the resin itself or blending flame retardants into the resin. In general, a method using a flame retardant is widely used.

As a flame retardant method, antimony oxide and a halide are conventionally blended into a thermoplastic resin. Such a flame retardant (self-extinguishing) composition is halogenated during combustion. This presents a problem that the hazardous gas is generated and creates a danger.
Formulation of phosphorus organic flame retardants is also known, but such organic flame retardants have a problem that flame retardants bleed out on the surface of the product and flame retardant properties cannot be maintained over the long term. .
In order to avoid such problems, there is no generation of harmful gas at the time of combustion, there is no problem with toxicity as an additive, there is no bleed out of flame retardant, aluminum hydroxide or magnesium hydroxide or these Flame retardant materials using hydrated metal compounds such as blends with magnesium carbonate are regarded as important.

However, in such a flame retardant material, in order to impart sufficient flame retardancy, it is necessary to blend a large amount of hydrated metal compound, resulting in flexibility, abrasion resistance, whitening resistance, There is a disadvantage that the mechanical strength (particularly, tensile strength and elongation) is remarkably lowered.
As a technique for improving such a problem, flame retardancy is achieved by blending an aluminum hydroxide and / or magnesium with an ethylene-unsaturated carboxylic acid copolymer and an epoxy group-containing compound in a thermoplastic resin, Although a composition has been disclosed in which resistance to whitening by external force and improvement in trauma resistance and cold resistance have been disclosed (Patent Document 1), flame retardancy has not yet been satisfied when various properties are improved.
A flame retardant resin composition excellent in moldability was proposed by blending an unsaturated carboxylic acid or its derivative-modified polyethylene, a metal hydrate, and an ethylene-based copolymer with a polypropylene resin (Patent Document). 2) There was a problem of insufficient wear resistance and whitening resistance.
In addition, a flame-retardant and abrasion-resistant resin composition in which a propylene-ethylene block copolymer, a polyolefin-based elastomer, and a metal hydroxide are blended to improve the dispersibility of the flame retardant has also been presented (Patent Literature). 3) Even though the abrasion resistance is improved, the whitening resistance is still insufficient.

Furthermore, as a method of using a specific resin excellent in heat resistance and flexibility, the elution component in the elution curve representing the relationship between the elution temperature and the integrated weight ratio of the elution component by the temperature rising elution fractionation method is specified, A flame retardant soft resin composition comprising 100 parts by weight of a propylene-ethylene block copolymer and 80 to 400 parts by weight of a metal hydroxide, in which a maximum peak temperature indicated by suggested scanning calorimetry is also specified, is disclosed. (Patent Document 4), this resin composition is whitened when an external force is applied, and presents a problem that the appearance is not satisfactory when a molded product is put to practical use.
Polypropylene resins manufactured with metallocene catalysts and specified in the elution curve of MFR or temperature rising elution fractionation method, etc. are blended with a large amount of inorganic flame retardant to give sufficient flame retardancy. However, there is a problem in that whitening occurs due to external force in the molded product, although both the properties and mechanical properties (particularly tensile elongation) are satisfied (Patent Document 5).

JP 63-189462 A (claim 1) JP 7-252388 A (summary) JP 2000-26696 A (summary) Japanese Patent Laid-Open No. 11-60888 (summary) JP 2004-26968 A (summary)

  In view of the current state of the above-mentioned background art in flame retardant of thermoplastic resins, the present invention generates toxic gas during combustion even if a large amount of inorganic flame retardant is blended in order to impart sufficient flame retardancy. Flame retardant (self-extinguishing) with excellent mechanical strength (especially tensile elongation), improved whitening resistance against external forces, and good flexibility and moldability. It is a problem to be solved by the present invention to develop a thermoplastic resin material for molded articles having a high thickness and a self-extinguishing molded article comprising the same.

With the aim of solving the above-mentioned problems of the invention, the present inventors can add a large amount of an inorganic flame retardant, and provide a thermoplastic resin material having excellent performance such as high tensile elongation and whitening resistance. A resin composition machine that combines a large amount of flame retardant with a thermoplastic resin such as polypropylene resin in consideration of the interaction between the resin material and inorganic flame retardant in various resin materials and compositions. The reason why the mechanical strength (especially tensile elongation) is remarkably lowered is that the dispersion of a large amount of flame retardant is difficult to be uniform, and peeling is likely to occur when stress is applied to the interface between the polypropylene resin and the flame retardant. I was able to find out.
By the way, the present inventors have developed a polypropylene resin having both good flexibility and transparency, heat resistance and rigidity, and excellent moldability. Such a specific propylene-ethylene random block copolymer has been developed. The block copolymer is very compatible with each resin component, and if it is used for the above flame retardant resin material, a large amount of inorganic difficulty can be obtained. While the dispersibility of the flame retardant is greatly improved and the stress when strain is applied is reduced, the stress applied to the interface between the polypropylene resin and the flame retardant is suppressed and the mechanical strength (especially tensile elongation) is reduced. It has been found that a significant decrease in the degree of whitening can be prevented, and that the whitening resistance is also improved, and the present invention has been realized.

  Specifically, as an inorganic flame retardant, there is no problem of harmful gas generation and toxicity at the time of combustion, and aluminum hydroxide, magnesium hydroxide, etc. are used in order to exhibit sufficient flame retardancy, ie self-extinguishing (self-extinguishing) Polypropylene, which is a factor for lowering the physical properties of conventional flame retardant compositions, using 50 to 300 parts by weight of metal hydrate component (hereinafter referred to as component (B)) (based on 100 parts by weight of resin material) Temperature-loss tangent (tan δ) obtained by solid viscoelasticity measurement (DMA) in order to improve the dispersibility of the inorganic flame retardant in the resin-based resin composition and to suppress peeling at the interface with the inorganic flame retardant. ) Specified by the peak characteristics in the curve and the elution characteristics in the elution curve by the temperature rising elution fractionation method (TREF), and has excellent flexibility and transparency, heat resistance and rigidity, etc. Propylene - ethylene copolymer component (hereinafter, referred to as component (A).) It is necessary to use.

More specifically, the propylene-ethylene copolymer component (A) used in the present invention is made of ethylene in order to improve the balance of various physical properties such as flexibility and heat resistance while improving the compatibility of the resin component. It is a propylene-ethylene random block copolymer consisting mainly of two components (A1) and (A2) having different contents and crystallinity.
The compatibility of the resin component is specified by the peak characteristics in the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA). For components having different ethylene content and crystallinity, an o-dichlorobenzene solvent is used. By observing two peaks in the TREF elution curve obtained as a plot of elution amount (dwt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. Furthermore, the crystallinity and ethylene content of each are specified by the elution characteristics.

The compatibility of the resin component is a single peak due to the glass transition observed in the temperature range of −60 to 20 ° C. in the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), and It is specified by its peak temperature being 0 ° C. or lower.
In the elution characteristics in the TREF elution curve, a peak T (A1) is observed on the high temperature side of 65 to 95 ° C., and a peak T (A2) is observed on the low temperature side of 45 ° C. or lower, and 2 at the intermediate temperature T (A3). When the components are separated, the low crystalline component (A2) eluted by T (A3) is a propylene / ethylene random copolymer containing 6 to 15 wt% of ethylene, and the ratio of the amount W (A2) is 5 to 5%. The component (A1) having a relatively high crystallinity after removal of the component eluted by T (A3) (after elution) is 70% by weight, and is a propylene / ethylene random copolymer containing 0 to 6% by weight of ethylene. The ratio of the amount W (A1) is specified by 95 to 30 wt%.

These components do not have a phase-separated structure even though they differ in ethylene content and crystallinity, so that peeling at the interface and uneven distribution of inorganic fillers are less likely to cause various problems in flame retardancy. In these components, the low crystalline component (A2) is effective in reducing the tensile elongation at break and suppressing the bending whitening by reducing the stress to the inorganic filler interface when an external force is applied. Is.
Furthermore, the component (A1) having a relatively high crystallinity is characterized by a low crystallinity distribution toward the high crystal side, and since the crystallinity distribution is narrow, it has a more uniform and fine crystal structure, resulting in a tensile elongation at break. Is improved. In the TREF elution curve, the temperature T (A4) at which 99 wt% is eluted is 90 ° C. or less, and the temperature difference ΔT (T (A4) −T (A1)) from the peak T (A1) to T (A4) is It is specified by being 5 ° C or lower.

  Since this propylene-ethylene copolymer component (A) is required to have a narrow composition and crystallinity distribution of each component, it is preferable to use a metallocene catalyst for its production. It consists of two components with greatly different amounts, and when these components are produced separately, there is a possibility of causing problems such as poor dispersion when preparing a composition to which an inorganic filler is added. .

  In the above, the background of the creation of the present invention and the characteristics of the configuration of the invention have been described generally. Therefore, in order to provide an overview of the present invention, the overall configuration of the present invention is described clearly. The basic invention is composed of the following group of invention units, and the one described in [1] is the basic invention, and the following inventions are added to the basic invention or made into an embodiment. . (The entire invention group is collectively referred to as “the present invention”.)

[1] It comprises 100 parts by weight of a propylene-ethylene copolymer component (A) satisfying the following conditions (i) to (ii) and 50 to 300 parts by weight of a metal hydrate component (B). A polypropylene resin composition for self-extinguishing molded articles.
(I) In the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), the peak due to the glass transition observed in the temperature range of −60 to 20 ° C. is a single peak. The temperature is 0 ° C or lower.
(Ii) TREF elution curve obtained as a plot of elution amount (dwt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. Satisfying the following conditions (ii-A) to (ii-C) (ii-A) Two peaks are observed in the elution curve, and the peak T (A1) observed on the high temperature side is 65 to 95 ° C. The peak T (A2) observed on the low temperature side is below 45 ° C. (ii-B) By the temperature T (A3) at the midpoint between both T (A1) and T (A2) peaks The amount W (A2) of the component (A2) to be eluted is 5 to 70 wt%, and the component is a propylene / ethylene random copolymer containing 6 to 15 wt% of ethylene (ii-C) T (A3) Of ingredients that elute in The amount (A1) of the component (A1) eluted after delivery is 95 to 30 wt%, and the component is a propylene / ethylene random copolymer containing 0 to 6 wt% of ethylene. [2] Propylene-ethylene copolymer The polypropylene resin composition for self-extinguishing molded articles according to [1], wherein the polymer component (A) satisfies the following condition (iii).
(Iii) Using a metallocene catalyst, 95 to 30 wt% of a crystalline propylene-ethylene random copolymer component (A1) having an ethylene content of 0 to 6 wt% in the first step, and an ethylene content of 6 to 6 in the second step It is obtained by sequentially polymerizing 15 wt% of a low crystalline propylene-ethylene random copolymer component (A2) in an amount of 5 to 70 wt%. [3] Component (A) satisfies the following condition (iv) A polypropylene resin composition for self-extinguishing molded articles according to [1] or [2], characterized by satisfying the above.
(Iv) TREF elution curve obtained as a plot of elution amount (dwt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. Satisfying the following conditions (iv-A) to (iv-D): (iv-A) Two peaks are observed in the elution curve, and the peak T (A1) observed on the high temperature side is 65 to 88 ° C. The peak T (A2) observed on the low temperature side is at 45 ° C. or lower (iv-B) The temperature T (A4) at which 99 wt% elutes is 90 ° C. or lower, and from the peak T (A1) The temperature difference ΔT (T (A4) −T (A1)) up to T (A4) is 5 ° C. or less (iv−C) The temperature T (T) between the T (A1) and T (A2) peaks. Amount W of component (A2) eluted by A3) 2) is 30 to 70 wt%, and the component is a propylene / ethylene random copolymer containing 8 to 14 wt% of ethylene (iv-D) A component that elutes after elution of a component that elutes by T (A3) The amount W (A1) of (A1) is 70 to 30 wt%, and the component is a propylene / ethylene random copolymer containing 1 to 5 wt% of ethylene. [4] The metal hydrate of component (B) is The polypropylene-based resin composition for self-extinguishing molded articles according to any one of [1] to [3], which is aluminum hydroxide and / or magnesium hydroxide.
[5] A self-extinguishing molded article obtained by molding the polypropylene resin composition for a self-extinguishing molded article according to any one of [1] to [4].
[6] A self-extinguishing molded article, wherein the self-extinguishing molded article in [5] is produced by extrusion molding.
(Although it is “consisting of” in [1], it is natural that other optional components are not excluded.)

  In the flame-retardant thermoplastic resin composition, even if a large amount of an inorganic flame retardant is blended in order to impart sufficient flame retardancy, there is no fear of generation of toxic gas at the time of combustion. Highly flame-retardant (self-extinguishing) thermoplastic resin with mechanical strength (particularly tensile elongation), improved whitening resistance against external forces, and good flexibility and moldability. A material and a self-extinguishing molded body made of the material are realized.

In the following, in order to describe the invention group in the present invention in detail, embodiments of the invention will be described in detail.
1. About flame retardancy Generally, plastic materials, especially thermoplastic resin moldable products are generally flammable, and thus there has been a strong demand for flame retardancy for safety in the use of molded products.
Conventionally, in polypropylene resins, a large amount of inorganic flame retardants must be blended to provide sufficient flame retardancy, and satisfy mechanical properties, particularly tensile elongation properties and flame retardant properties. In other words, it was difficult to set the oxygen index in JIS K7201 to 21 or more. In the present invention, a case where the oxygen index is less than 21 is called flammability, and a case where the oxygen index is 21 or more is called self-extinguishing (self-extinguishing).

The oxygen index (OI) is as follows.
A sheet of 3 mm was prepared by compression (press) molding at a temperature of 180 ° C., and a test piece having a width of 6.5 mm and a length of 150 mm was cut. The obtained test piece was measured for oxygen index according to the method of JIS K-7201.
Using an oxygen measuring device, the oxygen index was determined by measuring the minimum oxygen flow rate required for the test piece to burn continuously for 3 minutes or longer, or to continue burning after the flame was burned to 50 mm or longer. .
OI (%) = {[O ₂ ] / ([O ₂ ] + [N ₂ ])} × 100
[O ₂ ]: Flow rate of oxygen L / min [N ₂ ]: Flow rate of nitrogen L / min

2. About the composition of the resin composition of the present invention (1) Basic structure In the present invention, the polypropylene resin material having excellent flexibility and transparency, heat resistance and rigidity, and excellent moldability Propylene-ethylene random block copolymer is very compatible with each resin component, and if used as a flame retardant resin material, the dispersibility of a large amount of inorganic flame retardant is greatly improved and the strain is reduced. By reducing the stress at the time of application, it is possible to prevent stress from being applied to the interface between the polypropylene resin and the flame retardant, and to prevent a significant decrease in mechanical strength (particularly tensile elongation). Be improved.
The polypropylene resin composition for a self-extinguishing molded body of the present invention comprises a specific propylene-ethylene copolymer component (A) and a metal hydrate component (B) which is an inorganic filler imparting self-extinguishing properties. As required, additional components can be added as long as they do not impair the efficacy (effect) of the present invention. Each component must meet various requirements to solve problems. The detailed description of each component is added below.

(2) Explanation of each component (2-1) Propylene-ethylene copolymer component (A)
In conventional polypropylene resins, ethylene elastomer is blended as a low crystallinity component or a low content containing a large amount of ethylene in order to improve the tensile elongation at break of a relatively high crystallinity component mainly composed of propylene. Techniques for producing crystalline components by sequential polymerization and using so-called block copolymers are widely known to those skilled in the art, but these low crystalline components have low compatibility with components mainly composed of propylene. The phases are separated and each phase is separated into separate phases.
When a large amount of an inorganic filler for imparting self-extinguishing properties is added to the resin having such a structure, uneven distribution of the inorganic filler occurs due to different softening temperatures and compatibility with the filler in each phase. However, since the breakage tends to occur at a portion where the inorganic filler concentration is high, the effect of improving the tensile break elongation cannot be sufficiently exhibited. Further, when an external force is applied, peeling occurs not only between the inorganic filler and the resin but also at the interface of each phase, so that the problem that bending whitening is extremely deteriorated occurs.

The propylene-ethylene copolymer component (A) in the present invention is different from the above-mentioned conventional propylene resin material, and in order to improve the balance of physical properties, the ethylene content and the crystallinity are roughly divided into two components. (A1) It consists of (A2).
(I) Identification by measurement of solid viscoelasticity The propylene-ethylene copolymer component (A) used in the present invention contains a low crystalline component (A2) for improving the tensile elongation (tensile elongation at break). However, it is necessary not to have a phase-separated structure with the relatively high crystallinity component (A1) mainly composed of propylene.

The fact that the phase separation structure is not taken is that in the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), the tan δ curve has a single peak between −60 and 20 ° C. It is specified that the temperature is 0 ° C. or lower. The peak temperature is preferably −5 ° C. or lower, and more preferably −13 ° C. or lower.
This is because, in solid viscoelasticity measurement, the glass transition temperature of propylene-ethylene copolymer resin is usually observed between -60 and 20 ° C. as the peak of the tan δ curve. While only the transition temperature is observed, the phase separation structure is based on showing a plurality of peaks because the glass transition temperature of each phase is observed separately.

[Solid viscoelasticity measurement method]
Here, the solid viscoelasticity measurement is specifically performed by applying a sinusoidal strain of a specific frequency to a strip-shaped sample piece and detecting the generated stress. Here, the frequency is 1 Hz, and the measurement temperature is raised stepwise from −60 ° C. until the sample is melted and cannot be measured. Further, it is recommended that the magnitude of distortion is about 0.1 to 0.5%. From the obtained stress, the storage elastic modulus and the loss elastic modulus are obtained by a known method, and the loss tangent (= loss elastic modulus / storage elastic modulus) defined by the ratio thereof is plotted against the temperature. A sharp peak is shown in the temperature region. In general, the peak of tan δ at 0 ° C. or lower is for observing the glass transition of the amorphous part, and here, this peak temperature is defined as the glass transition temperature Tg (° C.).
In the entire measurement temperature range, another relaxation peak may appear at about 20 to 120 ° C., which is crystal relaxation called α relaxation, which is distinguished from the glass transition that is the subject of the present invention.

(Ii) Identification by temperature rising elution fractionation method (TREF) The low crystalline propylene / ethylene random copolymer component (A2) contained in the propylene-ethylene copolymer component (A) used in the present invention is Since it does not take a separation structure and has a sufficient effect of improving the tensile elongation at break, it is necessary to sufficiently reduce the crystallinity, and the compatibility decreases as the ethylene content increases. Must be kept within a certain range.
The propylene-ethylene random copolymer component (A1) contained in the propylene-ethylene copolymer component (A) used in the present invention has a low crystallinity distribution on the high crystal side. Since the crystallinity distribution is narrow, the tensile elongation at break is improved by taking a more uniform and fine crystal structure.

The crystallinity, crystallinity distribution, and ratio of each of these components are specified by a temperature-temperature elution fractionation method (TREF).
The technique for evaluating the crystallinity distribution of a propylene-ethylene copolymer by TREF is well known to those skilled in the art. For example, detailed measurement methods are shown in the following documents.
G. Glockner, J. et al. Appl. Polym. Sci. : Appl. Po
lym. Symp. 45, 1-24 (1990)
L. Wild, Adv. Polym. Sci. 98, 1-47 (1990)
J. et al. B. P. Soares, A .; E. Hamielec, Polymer; 36,
8, 1639-1654 (1995)
In TREF measurement, the lower the crystallinity, the lower the elution, and the higher the crystallinity, the higher the elution, so it is possible to accurately grasp the distribution of the crystallinity of the polypropylene resin. .
The propylene-ethylene random block copolymer in the present invention has a large difference in crystallinity of each of the components (A1) and (A2), and both components can be accurately separated by TREF.

[TREF measurement method]
In the present invention, the TREF measurement is specifically measured as follows.
A sample is dissolved in o-dichlorobenzene (containing 0.5 mg / mL BHT) at 140 ° C. to prepare a solution. After this is introduced into a TREF column at 140 ° C., it is cooled to 100 ° C. at a temperature decreasing rate of 8 ° C./min, subsequently cooled to −15 ° C. at a temperature decreasing rate of 4 ° C./min, and held for 60 minutes. Thereafter, o-dichlorobenzene (containing 0.5 mg / mL BHT) as a solvent is allowed to flow through the column at a flow rate of 1 mL / min, and components dissolved in o-dichlorobenzene at −15 ° C. in the TREF column. Elution is carried out for 10 minutes, and then the column is linearly heated to 140 ° C. at a heating rate of 100 ° C./hour to obtain an elution curve.

(Ii-A) Identification by Peak Temperature in Elution Curve Since the propylene-ethylene copolymer component (A) used in the present invention is roughly composed of two components and each has different crystallinity, in the TREF elution curve, Two peaks are observed. The fact that two peaks are not observed means that there is only one component, the amount of one is so small that it is not observed, or the crystallinity distribution is so wide that no peak is shown. Therefore, it is necessary that two peaks are observed in the propylene-ethylene copolymer component (A) used in the present invention.
In TREF measurement, the higher the elution temperature, the higher the crystallinity, and the lower the elution temperature, the lower the crystallinity. The propylene-ethylene random copolymer component (A1) contained in the propylene-ethylene copolymer component (A) used in the present invention has a relatively high crystallinity, and if the crystallinity is too low, the moldability deteriorates and the heat resistance increases. Therefore, the crystallinity should not be lowered excessively, and the peak temperature T (A1) needs to be 65 ° C. or higher. On the other hand, if the crystallinity becomes too high, the tensile breaking elongation decreases, so T (A1) needs to be 95 ° C. or lower.
On the other hand, the low crystalline propylene / ethylene random copolymer component (A2) contained in the propylene-ethylene copolymer component (A) used in the present invention has a tensile fracture unless the crystallinity is sufficiently lowered. Since the effect of improving the elongation cannot be exhibited, the peak temperature T (A2) needs to be 45 ° C. or lower.

(Ii-B, C)
The propylene-ethylene random copolymer component (A1) and the low crystallinity propylene / ethylene random copolymer component (A2) contained in the propylene-ethylene copolymer component (A) are TREF. Separation is almost possible at a temperature T (A3) between the peaks of both components observed in the elution curve. Here, T (A3) = [{T (A1) + T (A2)} / 2.
At this time, the component eluted by T (A3) is a low crystalline propylene / ethylene random copolymer component (A2), and the amount W (A2) is 5 to 70 wt%. In accordance with this, the component after elution by T (A3) (after elution) is a propylene / ethylene random copolymer component (A1) having relatively high crystallinity, and its amount W (A1) is 95 to 30 wt%.

W (A2) is a component necessary for improving the tensile elongation at break, and when W (A2) is less than 5 wt%, a sufficient improvement effect cannot be obtained, so W (A2) is at least 5 wt%. In order to exhibit a sufficient improvement effect, it is preferably 30 wt% or more. On the other hand, if there is too much W (A2), that is, if the amount of the component having relatively high crystallinity is too small, problems such as deterioration of moldability and deterioration of heat resistance occur, so W (A2) is 70 wt% or less. It is necessary to be.
The components separated at this time are taken out and analyzed, whereby the ethylene content in each component can be measured. Here, the low crystalline propylene / ethylene random copolymer component (A2) eluting up to T (A3) cannot exhibit the effect of improving the tensile breaking elongation unless the crystallinity is sufficiently lowered. Therefore, the peak temperature T (A2) needs to be 45 ° C. or less. At this time, the crystallinity of the propylene / ethylene random copolymer tends to decrease as the ethylene content increases. % Ethylene must be contained. On the other hand, since the phase separation structure is taken when the ethylene content becomes too large, it is essential to keep it within a range in which phase separation does not occur, and it is necessary to be at most 15 wt%.

On the other hand, the propylene / ethylene random copolymer component (A1) having a relatively high crystallinity after removing the components eluted by T (A3) (after elution) is to maintain moldability and heat resistance. The peak T (A1) needs to be in the range of 65 to 95 ° C., and if the crystallinity of the component (A1) is too high, the compatibility of the resin component is lowered. At this time, the ethylene content is 0 to 6 wt%. It is necessary to be in the range.
Here, if the crystallinity of the component (A1) is high, even if the component (A2) is improved, it is preferable to add as much inorganic filler as possible in order to improve the self-extinguishing property. There may be a shortage of elongation. In order to further improve this, it is preferable that the crystallinity of the component (A1) is also in a specific range.
That is, the crystallinity of the component (A1) itself is lowered within a range in which heat resistance and moldability can be maintained, and by selecting one having a narrow crystallinity distribution, the crystal structure is refined and the tensile elongation at break is improved. For this purpose, the ethylene content in the component (A1) is preferably 1 wt% or more, and the peak temperature T (A1) in the TREF elution curve, which is a measure of crystallinity, is preferably 88 ° C. or less. At this time, even if T (A1) decreases, the crystallinity distribution is widened, and if there are many highly crystalline components, the improvement effect is reduced. Therefore, the temperature T (A4) at which 99 wt% is eluted is 90 ° C. The following is preferable.

[Measurement method of ethylene content]
I. Separation of components (A1) and (A2) Based on T (C) determined by the previous TREF measurement, a T (A3) soluble component (A2) was obtained by a temperature rising column fractionation method using a preparative fractionator. ) And T (A3) insoluble component (A1), and the ethylene content of each component is determined by NMR.
The temperature rising column fractionation method is a measurement method disclosed in, for example, Macromolecules; 21, 314 to 319 (1988).

B. Fractionation conditions A cylindrical column having a diameter of 50 mm and a height of 500 mm is filled with a glass bead carrier (80 to 100 mesh) and maintained at 140 ° C. Next, 200 mL of a sample o-dichlorobenzene (ODCB) solution (10 mg / mL) dissolved at 140 ° C. is introduced into the column. Thereafter, the temperature of the column is cooled to 0 ° C. at a rate of temperature decrease of 10 ° C./hour. After holding at 0 ° C. for 1 hour, the column temperature is heated to T (A3) at a heating rate of 10 ° C./hour and held for 1 hour. The accuracy of column temperature control through a series of operations is ± 1 ° C.
Next, 800 mL of o-dichlorobenzene is allowed to flow at a flow rate of 20 mL / min while maintaining the column temperature at T (A3), thereby eluting and recovering components soluble in T (A3) present in the column.
Next, the column temperature is increased to 140 ° C. at a rate of temperature increase of 10 ° C./min, left at 140 ° C. for 1 hour, and then 800 mL of a 140 ° C. solvent (ODCB) is allowed to flow at a flow rate of 20 mL / min to obtain T (A3 ) To elute and collect insoluble components.
The solution containing the polymer obtained by fractionation is concentrated to 20 mL using an evaporator and then precipitated in 5 times the amount of methanol. The precipitated polymer is collected by filtration and dried overnight in a vacuum dryer.

C. Measurement by NMR The ethylene content of each of the components (A1) and (A2) obtained by the above fractionation is determined by analyzing a ¹³ C-NMR spectrum measured according to the following conditions by the proton complete decoupling method. .
Model: GSX-400 manufactured by JEOL Ltd. or equivalent equipment (carbon nuclear resonance frequency of 100 MHz or more)
Solvent: o-dichlorobenzene: heavy benzene = 4: 1 (volume ratio)
Concentration: 100 mg / mL Temperature: 130 ° C Pulse angle: 90 °
Pulse interval: 15 seconds Integration count: 5,000 times or more

The spectrum may be assigned with reference to, for example, Macromolecules; 17, 1950 (1984). The attribution of spectra measured under the above conditions is as shown in Table A below. Symbols such as S _αα in the table are Carman et al. (
According to the notation of Macromolecules; 10,536 (1977)), P represents a methyl carbon, S represents a methylene carbon, and T represents a methine carbon.

In the following, when “P” is a propylene unit in a copolymer chain and “E” is an ethylene unit, six types of triads of PPP, PPE, EPE, PEP, PEE, and EEE may exist in the chain. . As described in Macromolecules; 15, 1150 (1982) and the like, the concentration of these triads and the peak intensity of the spectrum are linked by the following relational expressions (1) to (6).
[PPP] = k × I (T _ββ ) (1)
[PPE] = k × I (T _βδ ) (2)
[EPE] = k × I (T _δδ ) (3)
[PEP] = k × I (S _ββ ) (4)
[PEE] = k × I (S _βδ ) (5)
[EEE] = k × {I (S _δδ ) / 2 + I (S _γδ ) / 4} (6)
Here, [] indicates the fraction of triads, for example, [PPP] is the fraction of PPP triads in all triads.
Therefore,
[PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 (7)
It is. Further, k is a constant, I indicates the spectral intensity, and for example, I (T _ββ ) means the intensity of the peak at 28.7 ppm attributed to T _ββ .
By using the relational expressions (1) to (7) above, the fraction of each triad is obtained, and the ethylene content is obtained from the following expression.
Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100
Note that the propylene random copolymer of the present invention contains a small amount of propylene heterogeneous bonds (2,1-bonds and / or 1,3-bonds), and thereby the minute amounts described in Table B below. A peak is produced.

In order to obtain an accurate ethylene content, it is necessary to take into account the peaks derived from these heterogeneous bonds, but it is difficult to completely separate and identify the peaks derived from heterogeneous bonds. Therefore, the ethylene content of the present invention is the relational expression (1) to (7) as in the analysis of the copolymer produced with a Ziegler-Natta catalyst that does not substantially contain a heterogeneous bond. It is determined using
Conversion from mol% to wt% of ethylene content is performed using the following formula.
Ethylene content (% by weight) = (28 × X / 100) / {28 × X / 100 + 42 × (1−X / 100)} × 100
Here, X is the ethylene content in mol%.
The ethylene content of the entire block copolymer is the weight of each component calculated from the ethylene contents [E] A, [E] B, and TREF of the components (A) and (B) measured above. It is calculated from the ratios W (A) and W (B) [wt%] by the following formula.
[E] W = [E] A × W (A) / 100 + [E] B × W (B) / 100 (wt%)

(2-2) Metal hydrate component (B)
The metal hydrate component (B) is a component necessary for exerting self-extinguishing properties without causing toxic gas generation and toxicity problems during combustion, and is an inorganic flame retardant aluminum hydroxide that is a metal hydrate. And / or magnesium hydroxide is selected.
From the viewpoint of dispersibility, the average particle size is preferably 0.2 to 4 μm, more preferably 0.5 to 2 μm. Furthermore, a surface treatment may be performed as desired. Examples of the surface treatment agent include stearic acid, a silane coupling agent, a titanate coupling agent, and the like. However, when the surface treatment amount is increased, there is a problem of a decrease in wear resistance. Therefore, the content of the treatment agent is preferably 0.5% by weight or less. Among these, magnesium hydroxide is particularly optimal in terms of practical performance.
Moreover, you may mix | blend red phosphorus, a polyphosphate, a urea compound, silicone oil, silicone powder, etc. with a metal hydrate component (B) as a flame retardant adjuvant as needed.

  At this time, the oxygen index (JIS K7201 3 mm thick sheet) of the self-extinguishing molded body is preferably 21 or more, more preferably 23 or more, and further preferably 25 or more, and has excellent self-extinguishing properties (self-extinguishing). Since it is calculated | required to have, it is necessary for a metal hydrate component (B) to exist in the range of 50-300 weight part with respect to 100 weight part of polypropylene resins, Preferably it is 100-200 weight part. If the metal hydrate component (B) is less than 50% by weight, appropriate flame retardancy cannot be obtained, and if it exceeds 300 parts by weight, the desired tensile elongation at break and improvement in bend whitening can be obtained. Absent.

3. Production method of composition material of the present invention (3-1) Production method of composition In the present invention, the polypropylene resin composition for self-extinguishing molded article is composed of propylene-ethylene copolymer component (A) and metal hydrate. Component (B) is an essential component and, if desired, additional components are blended within a range that does not impair the efficacy of the present invention, and these are produced using a known melt-kneading method such as a twin-screw extruder, roll, or Banbury mixer. be able to.
For example, after mixing each component at room temperature, it may be produced by melt kneading using a biaxial kneading extruder, or a feed hole is provided in the middle of the kneading extruder, from which metal hydrate is added. You may manufacture by feeding and melt-kneading simultaneously.
The self-extinguishing molded body of the present invention is generally a pellet made of the propylene-based resin composition for self-extinguishing molded body obtained above, but in the masterbatch method or the dry blend method, It can be molded in a pellet blend state, or can be molded while continuously weighing and weighing using a gravimetric feeder or the like.

(3-2) Method for Producing Propylene-Ethylene Copolymer Component (A) The propylene-ethylene copolymer component (A) used in the present invention is a propylene / ethylene random copolymer having relatively high crystallinity. As long as the component (A1) and the low crystallinity propylene / ethylene random copolymer component (A2) are mainly composed of two types of propylene / ethylene random copolymers having different crystallinity, the requirements of the present invention are met. Any other manufacturing method may be used.
However, since the component (A1) and the component (A2) are different in crystallinity, the melting temperature is also greatly different. When each component is melted and kneaded separately, the component (A2) melts at an extremely early stage, and then the temperature Since the component (A1) is melted after further rising, the inorganic filler is concentrated in the previously melted component (A2), and dispersion failure tends to occur. Therefore, the component (A1) and the component (A2) are most preferably produced by sequential polymerization.

Ingredient (a1)
(3-2-1) Polymerization Method (i) Sequential Polymerization of Component (A1) and Component (A2) In carrying out the production of component (A1) and component (A2) of the present invention, component (A1) and component ( It is preferable to sequentially polymerize A2).
At this time, since component (A2) is a copolymer having a high ethylene content and easily sticking alone, component (A2) is polymerized after component (A1) is polymerized in order to prevent problems such as adhesion to the reactor. ) Is preferably used.

When performing sequential polymerization, either a batch method or a continuous method can be used, but it is generally desirable to use a continuous method from the viewpoint of productivity.
In the case of a batch method, it is possible to polymerize component (A1) and component (A2) separately using a single reactor by changing the polymerization conditions with time. As long as the efficacy of the present invention is not impaired, a plurality of reactors may be connected in parallel.
In the case of a continuous process, it is necessary to use a production facility in which two or more reactors are connected in series because it is necessary to individually polymerize the component (A1) and the component (A2), but as long as the effectiveness of the present invention is not impaired. A plurality of reactors may be connected in series and / or in parallel for each of the component (A1) and the component (A2).

(Ii) Polymerization process As the polymerization process, any polymerization method such as a slurry method, a bulk method, or a gas phase method can be used. Although supercritical conditions can be used as intermediate conditions between the bulk method and the gas phase method, they are substantially the same as the gas phase method, and are therefore included in the gas phase method without particular distinction.
Here, since the component (A2) having a high ethylene content is easily dissolved in an organic solvent such as hydrocarbon or liquefied propylene, it is desirable to use a gas phase method for the production of the component (A2).
Any process may be used for the production of the crystalline propylene-ethylene random copolymer component (A1), but in the case of producing the component (A1) having relatively low crystallinity, adhesion, etc. In order to avoid this problem, it is desirable to use a vapor phase method.
Therefore, it is most desirable that the component (A1) is first polymerized by the bulk method or the gas phase method and the component (A2) is subsequently polymerized by the gas phase method using the continuous method.

(Iii) Other polymerization conditions The polymerization temperature can be used without any particular problem as long as it is within a commonly used temperature range. Specifically, a range of 0 to 200 ° C, more preferably 40 to 100 ° C can be used.
The polymerization pressure varies depending on the process to be selected, but can be used without any problem as long as it is in a pressure range usually used. Specifically, a range of greater than 0 to 200 MPa, more preferably 0.1 to 50 MPa can be used. In that case, inert gas, such as nitrogen, can also coexist.
In the case where the sequential polymerization of the component (A1) in the first step and the component (A2) in the second step is performed, it is desirable to add a polymerization inhibitor into the system in the second step. When a polymerization inhibitor is added to the reactor in which ethylene-propylene random copolymerization in the second step is performed, product quality such as particle properties (fluidity, etc.) and gel of the obtained powder can be improved. Various technical studies have been made on this method, and examples thereof include Japanese Patent Publication No. 63-54296, Japanese Patent Application Laid-Open No. 7-25960, Japanese Patent Application Laid-Open No. 2003-2939, and the like. It is desirable to apply the method to the present invention.

(3-2-2) Metallocene catalyst Each component must have a narrow crystallinity distribution, that is, a narrow composition distribution. Therefore, in the Ziegler-Natta type catalyst that has been widely used in the production of polypropylene resins in the past, It is difficult to produce a propylene / ethylene random copolymer that satisfies the requirements of the present invention. Therefore, it is most preferable to use a metallocene catalyst for the production.
The type of the metallocene-based catalyst is not particularly limited as long as it can produce a copolymer having the performance of the present invention. However, in order to satisfy the requirements of the present invention, for example, the following components ( It is preferable to use a metallocene catalyst comprising a) and (b) and a component (c) to be used as necessary.
Component (a): At least one metallocene transition metal compound selected from the transition metal compounds represented by the general formula (1) Component (b): At least one selected from the following (b-1) to (b-4) Seed solid
Component (b-1) Particulate carrier carrying an organoaluminum compound (b-2) An ionic compound or Lewis acid capable of reacting with component (a) to convert component (a) to a cation (B-3) Solid acid fine particles (b-4) Ion exchange layered silicate Component (c): Organoaluminum compound

(I) Component (a)
As the component (a), at least one metallocene transition metal compound selected from transition metal compounds represented by the following general formula (1) can be used.
^{_{Q (C 5 H 4-a}} -aR 1) (C 5 H 4-b -bR 2) MeXY (1)
[Wherein Q represents a divalent linking group that bridges two conjugated five-membered ring ligands, Me represents a metal atom selected from titanium, zirconium, and hafnium, and X and Y represent hydrogen atoms. , A halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group or a silicon-containing hydrocarbon group, and X and Y are each independently, that is, the same or different Good. R ¹ and R ² represent hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. . a and b are the number of substituents. ]

Specifically, Q represents a divalent linking group that bridges two conjugated five-membered ring ligands. For example, a divalent hydrocarbon group, a silylene group, an oligosilylene group, or a hydrocarbon group as a substituent. Examples thereof include a silylene group or an oligosilylene group, or a germylene group having a hydrocarbon group as a substituent. Among these, preferred is a silylene group having a divalent hydrocarbon group and a hydrocarbon group as a substituent.
X and Y represent a hydrogen atom, a halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a silicon-containing hydrocarbon group. Among these, hydrogen is preferable , Chlorine, methyl, isobutyl, phenyl, dimethylamide, diethylamide group and the like.
R ¹ and R ² represent hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. . Specific examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a phenyl group, a naphthyl group, a butenyl group, and a butadienyl group. In addition, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing hydrocarbon group, boron-containing hydrocarbon group or phosphorus-containing hydrocarbon group include methoxy group, ethoxy group, phenoxy group, trimethylsilyl group. Typical examples include a group, diethylamino group, diphenylamino group, pyrazolyl group, indolyl group, dimethylphosphino group, diphenylphosphino group, diphenylboron group, dimethoxyboron group and the like. In these, it is preferable that it is a C1-C20 hydrocarbon group, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, and a butyl group.
By the way, adjacent R ¹ and R ² may combine to form a ring, on which a hydrocarbon group, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing You may have a substituent which consists of a hydrocarbon group, a boron containing hydrocarbon group, or a phosphorus containing hydrocarbon group.
Me is a metal atom selected from titanium, zirconium and hafnium, preferably zirconium and hafnium.

  Among the components (a) described above, preferred for the production of the propylene polymer of the present invention is a substituted cyclopentadienyl group crosslinked with a hydrocarbon-substituted silylene group, germylene group or alkylene group. A transition metal compound comprising a ligand having a substituted indenyl group, a substituted fluorenyl group, or a substituted azulenyl group, and particularly preferably a 2,4-position-substitution bridged by a silylene group or a germylene group having a hydrocarbon substituent It is a transition metal compound comprising a ligand having an indenyl group and a 2,4-position substituted azulenyl group.

Non-limiting specific examples include dimethylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, diphenylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, dimethylsilylene bis (2-methyl). Benzoindenyl) zirconium dichloride, dimethylsilylenebis {2-isopropyl-4- (3,5-diisopropylphenyl) indenyl} zirconium dichloride, dimethylsilylenebis (2-propyl-4-phenanthrylindenyl) zirconium dichloride, dimethyl Silylene bis (2-methyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylene bis {2-methyl-4- (4-chlorophenyl) azurenyl} zirconium dichloride, dimethylsilylene bi (2-Ethyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis (2-isopropyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis {2-ethyl-4- (2-fluorobiphenyl) azurenyl} zirconium Dichloride, dimethylsilylenebis {2-ethyl-4- (4-t-butyl-3-chlorophenyl) azurenyl} zirconium dichloride, and the like can be given.
A compound in which the silylene group of these specific examples is replaced with a germylene group and zirconium is replaced with hafnium is also exemplified as a suitable compound.
In addition, since the catalyst component is not an important element of the present invention, it avoids complicated listing and is limited to a representative example, but it is obvious that the effective range of the present invention is not limited by this. It is.

(Ii) Component (b)
As the component (b), at least one solid component selected from the components (b-1) to (b-4) described above is used. Each of these components is a known component, and can be appropriately selected from known technologies and used. Specific examples and manufacturing methods thereof are described in detail in JP-A No. 2002-284808, JP-A No. 2002-53609, JP-A No. 2002-69116, JP-A No. 2003-105015, and the like.
Here, as the particulate carrier used for the component (b-1) and the component (b-2), inorganic oxides such as silica, alumina, magnesia, silica alumina, silica magnesia, magnesium chloride, magnesium oxychloride, chloride Examples thereof include inorganic halides such as aluminum and lanthanum chloride, and porous organic carriers such as polypropylene, polyethylene, polystyrene, styrene divinyl benzene copolymer, and acrylic acid copolymer.

As a non-limiting specific example of the component (b), as the component (b-1), a fine particle carrier on which methylalumoxane, isobutylalumoxane, methylisobutylalumoxane, aluminum butylboronate tetraisobutyl or the like is supported, As component (b-2), triphenylborane, tris (3,5-difluorophenyl) borane, tris (pentafluorophenyl) borane, triphenylcarbonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium Particulate carrier carrying tetrakis (pentafluorophenyl) borate, etc. as component (b-3), alumina, silica alumina, magnesium chloride, etc. as component (b-4), montmorillonite, zakonite, beidellite, non Tronite, Sa Knight, hectorite, stevensite, bentonite, smectite group such as taeniolite, vermiculite, and the like mica group. These may form a mixed layer.
Particularly preferred among the above components (b) is the ion-exchange layered silicate of component (b-4), and more preferred are chemical treatments such as acid treatment, alkali treatment, salt treatment, and organic matter treatment. It is an ion exchange layered silicate applied.

(Iii) Component (c)
Examples of organoaluminum compounds used as component (c) as needed are:
General formula AlR _a X _3-a
(Wherein R is a hydrocarbon group having 1 to 20 carbon atoms, X is hydrogen, halogen, alkoxy group, a is a number of 0 <a ≦ 3), trimethylaluminum, triethylaluminum, tripropylaluminum, Trialkylaluminum such as triisobutylaluminum or halogen- or alkoxy-containing alkylaluminum such as diethylaluminum monochloride, diethylaluminum monomethoxide. In addition, aluminoxanes such as methylaluminoxane can also be used. Of these, trialkylaluminum is particularly preferred.

(Iv) Formation of catalyst Component (a) and component (b) are further brought into contact with component (c) as necessary to form a catalyst. The contact method is not particularly limited, but the contact can be made in the following order. Moreover, this contact may be performed not only at the time of catalyst preparation but also at the time of prepolymerization with olefin or at the time of polymerization of olefin.
1) Contact component (a) and component (b) 2) Add component (c) after contacting component (a) and component (b) 3) Contact component (a) and component (c) 4) Add component (b) after contact 4) Add component (a) after contacting component (b) and component (c) 5) Contact three components simultaneously

The amount of components (a), (b) and (c) used in the present invention is arbitrary. For example, the amount of component (a) used relative to component (b) is preferably in the range of 0.1 μmol to 1,000 μmol, particularly preferably 0.5 μmol to 500 μmol, relative to 1 g of component (b). The amount of component (c) used relative to component (b) is preferably such that the amount of aluminum metal is 0.001 to 100 mmol, particularly preferably 0.005 to 50 mmol, relative to 1 g of component (b). Therefore, the amount of the component (c) relative to the component (a) is preferably in the range of 10 ⁻³ to 10 ⁶ , particularly preferably in the range of 10 ⁻² to 10 ⁵ , in terms of the molar ratio of the metal.

(V) Prepolymerization treatment The catalyst of the present invention is preferably subjected to a prepolymerization treatment comprising preliminarily contacting an olefin and polymerizing a small amount. The olefin to be used is not particularly limited, but ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, styrene and the like can be used. It is possible to use, and it is particularly preferable to use propylene. The olefin can be supplied by any method such as a supply method for maintaining the olefin at a constant speed or in a constant pressure state, a combination thereof, or a stepwise change. The prepolymerization temperature and time are not particularly limited, but are preferably in the range of −20 ° C. to 100 ° C. and 5 minutes to 24 hours, respectively. The prepolymerization amount is preferably 0.01 to 100 parts, more preferably 0.1 to 50 parts, based on the component (b). After completion of the prepolymerization, the catalyst can be used as it is, depending on the usage form of the catalyst. However, if necessary, drying can be performed.
Furthermore, a polymer such as polyethylene, polypropylene, or polystyrene, or an inorganic oxide solid such as silica or titania can be allowed to coexist during or after the contact of the above components.

4). Additional component An additional component can be mix | blended with the polypropylene resin composition for self-extinguishing molded objects of this invention in the range which does not impair the effect of this invention. For example, heat stabilizer, antioxidant, weather stabilizer, ultraviolet absorber, crystal nucleating agent, copper damage inhibitor, antistatic agent, slip agent, anti-blocking agent, antifogging agent, colorant, filler, metal An inert agent, an elastomer, a petroleum resin, an antibacterial agent, an anti-anticide, etc. can be blended.

5. Applications and Forming Method of the Present Invention Examples of applications of the present invention include, for example, the fields of coated extruded products such as wire coating, steel pipe coating, steel wire coating, cable coating, construction / civil engineering industrial materials, home appliance parts, and automobiles. Examples include parts.
The self-extinguishing molded article of the present invention can be preferably produced, for example, by coating extrusion molding and / or profile extrusion molding of a polypropylene resin composition for self-extinguishing molding.
Examples of the coated extrusion-molded body include electric wire coating, steel pipe coating, steel wire coating, and cable coating.

  In order to describe the present invention more specifically, examples and comparative examples will be described below. However, in order to clarify the present invention, preferred examples are described. This demonstrates the significance and rationality of the requirements of the composition of the invention and the superiority of the comparative example over the prior art.

[Measurement method of each data]
1) Melt flow rate (MFR)
According to JIS K7210 A method condition M, it measured on condition of the following.
Test temperature: 230 ° C Nominal load: 2.16kg Die shape: Diameter 2.095mm Length 8.00mm

2) TREF
[Create elution curve]
According to the method described above in paragraph 0026.
[apparatus]
(TREF part)
TREF column: 4.3 mmφ × 150 mm stainless steel column Column packing material: 100 μm Surface inactive glass beads Heating method: Aluminum heat block Cooling method: Peltier element (Peltier element is cooled by water)
Temperature distribution: ± 0.5 ° C
Temperature controller: Chino Corporation Digital Program Controller KP1000 (Valve Oven)
Heating method: Air bath oven Measurement temperature: 140 ° C
Temperature distribution: ± 1 ° C Valve: 6-way valve 4-way valve (Sample injection part)
Injection method: Loop injection method Injection amount: Loop size 0.1ml
Inlet heating method: Aluminum heat block Measurement temperature: 140 ° C
(Detection unit)
Detector: Fixed wavelength infrared detector FOXBORO MIRAN 1A
Detection wavelength: 3.42 μm
High-temperature flow cell: LC-IR micro flow cell Optical path length 1.5mm Window shape 2
φ × 4mm long round Synthetic sapphire window measurement temperature: 140 ℃
(Pump part)
Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co. [Measurement conditions]
Solvent: o-dichlorobenzene (contains 0.5 mg / mL BHT)
Sample concentration: 5 mg / mL Sample injection amount: 0.1 mL Solvent flow rate: 1 mL / min

3) Measurement of solid viscoelasticity A sample cut into a strip of 10 mm width × 18 mm length × 2 mm thickness from a 2 mm thick sheet injection molded under the following conditions was used. The apparatus used was ARES manufactured by Rheometric Scientific. The frequency is 1 Hz. The measurement temperature was raised stepwise from −60 ° C., and the measurement was performed until the sample melted and became impossible to measure. The strain was performed in the range of 0.1 to 0.5%.
[Create specimen]
Standard number: JIS-7152 (ISO294-1)
Molding machine: TU-15 injection molding machine manufactured by Toyo Machine Metal Co., Ltd. Molding machine set temperature: 80, 80, 160, 200, 200, 200 ° C. from below the hopper
Mold temperature: 40 ° C. Injection speed: 200 mm / s (speed in the mold cavity)
Injection pressure: 800 kgf / cm ² Holding pressure: 800 kgf / cm ²
Holding time: 40 seconds Mold shape: Flat plate (thickness 2 mm, width 30 mm, length 90 mm)

4) DSC
Using a Seiko DSC, take 5.0 mg of sample, hold at 200 ° C. for 5 minutes, crystallize to 40 ° C. at a rate of temperature decrease of 10 ° C./min, and further melt at a rate of temperature increase of 10 ° C./min. The melting peak temperature was Tm (unit: ° C.). DHm was determined from the area of the endothermic curve at the time of temperature increase.

5) Oxygen index According to the method described in paragraph 0018.
6) Calculation of ethylene content According to the method described in detail in paragraphs 0031 to 0038.

[Polymerization Production Example A-1]
(Preparation of prepolymerization catalyst)
Silicate chemical treatment: To a glass separable flask with a 10 liter stirring blade, 3.75 liters of distilled water was added slowly followed by 2.5 kg of concentrated sulfuric acid (96%). At 50 ° C., 1 kg of montmorillonite (Menzawa Chemical Co., Ltd. Benclay SL; average particle size = 25 μm, particle size distribution = 10-60 μm) was further dispersed, heated to 90 ° C., and maintained at that temperature for 6.5 hours. After cooling to 50 ° C., the slurry was filtered under reduced pressure to recover the cake. 7 liters of distilled water was added to this cake to reslurry it, and then filtered. This washing operation was performed until the pH of the washing solution (filtrate) exceeded 3.5. The collected cake was dried at 110 ° C. overnight under a nitrogen atmosphere. The weight after drying was 707 g.
Drying of silicate: The previously treated silicate was dried with a kiln dryer. Specifications and drying conditions are as follows.
Rotating cylinder: Cylindrical inner diameter 50 mm Heating zone 550 mm (Electric furnace) Speed with rotating blade: 2 rpm Tilt angle: 20/520 Silicate feed rate: 2.5 g / min Gas flow rate: Nitrogen 96 liters / hour Countercurrent drying Temperature: 200 ° C (powder temperature)
Catalyst preparation: A 16 liter autoclave with stirring and temperature control was thoroughly replaced with nitrogen. 200 g of dry silicate was introduced, 1160 ml of mixed heptane and 840 ml of a heptane solution of triethylaluminum (0.60 M) were added and stirred at room temperature. After 1 hour, the mixture was washed with mixed heptane to prepare 2,000 ml of silicate slurry. Next, 9.6 ml of a heptane solution of triisobutylaluminum (0.71 M / L) was added to the silicate slurry prepared above and reacted at 25 ° C. for 1 hour. In parallel, 270 ml of (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] zirconium and 2,180 mg (0.3 mM) of mixed heptane Then, 33.1 ml of a heptane solution of triisobutylaluminum (0.71 M) was added, and the mixture reacted at room temperature for 1 hour was added to the silicate slurry. After stirring for 1 hour, 5,000 ml was added with mixed heptane. Prepared.
Preliminary polymerization / washing: Subsequently, the temperature in the tank was raised by 40 ° C., and when the temperature was stabilized, propylene was supplied at a rate of 100 g / hour to maintain the temperature. After 4 hours, the supply of propylene was stopped and maintained for another 2 hours.
After completion of the prepolymerization, the remaining monomer was purged, the stirring was stopped and the mixture was allowed to stand for about 10 minutes, and then the supernatant was decanted to 2,400 ml. Subsequently, 9.5 ml of a heptane solution of triisobutylaluminum (0.71 M / L) and 5,600 ml of mixed heptane were further added, stirred for 30 minutes at 40 ° C., allowed to stand for 10 minutes, and then 5,600 ml of the supernatant was removed. It was. This operation was further repeated 3 times. When the component analysis of the final supernatant was performed, the concentration of the organoaluminum component was 1.23 mM mol / L, the Zr concentration was 8.6 × 10 ⁻⁶ g / L, and the abundance in the supernatant with respect to the charged amount Was 0.016%. Subsequently, 170 ml of a heptane solution of triisobutylaluminum (0.71 M / L) was added, followed by drying at 45 ° C. under reduced pressure. A prepolymerized catalyst containing 2.0 g of polypropylene per 1 g of catalyst was obtained.
Using this prepolymerized catalyst, a propylene-ethylene copolymer was produced according to the following procedure.

(polymerization)
In the first step, propylene-ethylene random copolymerization was carried out using a liquid phase polymerization tank with a stirring device having an internal volume of 0.4 m ³ . Liquefied propylene, liquefied ethylene, and triisobutylaluminum were continuously fed at 90 kg / hour, 4.2 kg / hour, and 21.2 g / hour, respectively. The hydrogen supply amount was adjusted so that the MFR in the first step became a target value. Further, the above prepolymerized catalyst was supplied as a catalyst (excluding the weight of the prepolymerized polymer) so as to be 6.9 g / hour. The polymerization tank was cooled so that the polymerization temperature was 45 ° C.
When the propylene-ethylene random copolymer obtained in the first step was analyzed, BD (bulk density) was 0.46 g / cc, MFR was 7.0 g / 10 min, and ethylene content was 3.7 wt%. .

In the second step, propylene-ethylene random copolymerization was carried out using a stirred gas phase polymerization tank having an internal volume of 0.5 m ³ . The slurry containing polymer particles was continuously withdrawn from the liquid phase polymerization tank in the first step, flushed with liquefied propylene, and then pressurized with nitrogen and continuously supplied to the gas phase polymerization tank. The polymerization tank was controlled so that the temperature was 80 ° C. and the total partial pressure of propylene, ethylene and hydrogen was 1.5 MPa. At that time, the concentration of propylene, ethylene and hydrogen in the total partial pressure of propylene, ethylene and hydrogen was controlled to be 66.97 vol%, 32.99 vol% and 420 volppm, respectively. Furthermore, ethanol was supplied to the gas phase polymerization tank as an activity inhibitor. The supply amount of ethanol was set to 0.3 mol / mol with respect to aluminum in TIBA supplied along with the polymer particles supplied to the gas phase polymerization tank.
When the obtained propylene-ethylene copolymer was analyzed, the activity was 8.7 kg / g-catalyst, BD was 0.41 g / cc, MFR was 7.0 g / 10 min, and the ethylene content was 8.7 wt%. Met.

(Measurement)
The obtained propylene-ethylene copolymer (PP-1) was measured for TREF, ethylene content, DSC, GPC, and solid viscoelasticity.
Table 2 shows the data obtained by the measurement.
From the measurement results obtained, it can be said that PP-1 satisfies all the requirements as the propylene-ethylene copolymer component (A).

[Polymerization Production Examples A-2 to 10]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce propylene-ethylene copolymers (PP-2 to 10). The polymerization conditions and polymerization results are shown in Table 1, and various analysis results of the obtained PP-2 to 10 are shown in Table 2.

[Polymerization Production Example A-11]
In Polymerization Production Example A-1, polymerization was carried out in the same manner as in Polymerization Production Example A-1 except that only the first step was carried out without carrying out the second step, and a propylene-ethylene random copolymer (PP -11) was produced. The polymerization conditions and polymerization results are shown in Table 1, and various analysis results of the obtained PP-11 are shown in Table 2.

[Polymerization Production Examples A-12 to 13]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce propylene-ethylene copolymers (PP-12 to 13). The polymerization conditions and polymerization results are shown in Table 1, and various analysis results of the obtained PP-12 to 13 are shown in Table 2.

[Polymerization Production Example A-14]
(Preparation of solid catalyst component) 2,000 milliliters of dehydrated and deoxygenated n-heptane was introduced into a fully nitrogen-substituted flask, and then 2.6 mol of MgCl ₂ and Ti (On-C ₄ H _{9 4} ) 5.2 mol was introduced and reacted at 95 ° C. for 2 hours. After completion of the reaction, the temperature was lowered to 40 ° C., and then 320 ml of methylhydropolysiloxane (20 centistokes) was introduced and reacted for 3 hours. The resulting solid component was washed with n-heptane.
Next, 4,000 milliliters of n-heptane purified in the same manner as described above was introduced into a sufficiently nitrogen-substituted flask, and 1.46 mol of the solid component synthesized above was introduced in terms of Mg atoms. Next, 25 ml of n-heptane was mixed with 2.62 mol of SiCl ₄ , introduced into the flask at 30 ° C. for 30 minutes, and reacted at 70 ° C. for 3 hours. After completion of the reaction, washing with n-heptane was performed. Next, 0.15 mol of phthalic acid chloride was mixed with 25 ml of n-heptane, introduced into the flask at 70 ° C. for 30 minutes, and reacted at 90 ° C. for 1 hour. After completion of the reaction, washing with n-heptane was performed. Next, 11.4 mol of TiCl ₄ was introduced and reacted at 110 ° C. for 3 hours. After completion of the reaction, the solid component (A1) was obtained by washing with n-heptane. The titanium content of this solid component was 2.0 wt%.
Next, the autoclave having an internal volume of 16 liters having a stirring and temperature control device was sufficiently replaced with nitrogen, and 5,000 milliliters of n-heptane purified in the same manner as above was introduced into the solid component (A1 ) Was introduced, and 0.875 mol of SiCl ₄ was introduced and reacted at 90 ° C. for 2 hours. After completion of the reaction, further (CH ₂ ═CH) Si (CH ₃ ) ₃ 0.15 mol, (t-C ₄ H ₉ ) (CH ₃ ) Si (OCH ₃ ) ₂ 0.075 mol and Al (C ₂ H ₅ ) ₃ 0.4 mol was sequentially introduced and contacted at 30 ° C. for 2 hours. After completion of the contact, the solid catalyst component (A) mainly composed of magnesium chloride was obtained by thoroughly washing with n-heptane. The titanium content of this product was 1.8 wt%.
(Preliminary polymerization) An autoclave having an internal volume of 16 liters having a stirring and temperature control device was sufficiently replaced with nitrogen. Here, 100 g of the n-heptane slurry of the solid catalyst component (A) prepared above was introduced as the solid catalyst component (A), and n-heptane was further introduced to adjust the liquid level to 5,000 ml. Next, the temperature in the tank was adjusted to 15 ° C., and 0.1 mol of triethylaluminum / n-heptane solution (10 wt%) was added as Al (C ₂ H ₅ ) ₃ . Thereafter, prepolymerization was performed by supplying propylene at a rate of 50 g / hour for 2 hours. After completion of the prepolymerization, the residual monomer was purged and the solid catalyst was thoroughly washed with n-heptane. After the washing, drying under reduced pressure was performed to obtain a prepolymerized catalyst. The prepolymerized catalyst contained 2.0 g of polypropylene per 1 g of the catalyst.
(Polymerization) Polymerization Production Example A, except that the obtained prepolymerization catalyst was used and triethylaluminum was continuously fed at 10 g / hour instead of triisobutylaluminum, and the polymerization conditions shown in Table 1 were used. Propylene-ethylene copolymer (PP-14) was produced in the same manner as -1. The polymerization results are shown in Table 1, and various analysis results of the obtained PP-14 are shown in Table 2.

[Polymerization Production Example A-15]
In the same manner as in Polymerization Production Example A-14, the polymerization conditions were changed to produce a propylene-ethylene copolymer (PP-15). Table 1 shows polymerization conditions and polymerization results, and Table 2 shows various analysis results of the obtained PP-15.

[Example 1]
(Production of composition)
Compounding: Component (B) magnesium hydroxide (manufactured by Kyowa Chemical Co., Kismar 5A) with respect to 100 parts by weight of the propylene-ethylene copolymer (PP-1) obtained in Production Example A-1 as component (A) 150 parts by weight, and the following ingredients were blended as additives.
Dispersant: 0.3 parts by weight of magnesium stearate (reagent grade 1) Antioxidant 1: Tris (2,4-di-t-butylphenyl) phosphite (Ciba Specials Chemical Co., Ltd., Irgaphos 168) 2 parts by weight Antioxidant 2: Tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4-hydroxyphenyl) propionate] methane (Ciba Specials Chemical Co., Ltd., Irganox 1010) 1 part by weight Antioxidant 3: 0.2 part by weight of dimyristyl thiodipropionate (Sumitomo Chemical Co., Ltd., Sumitizer TPD) These are blended using a super mixer and melted under the following conditions using a twin screw extruder It knead | mixed and the polypropylene-type resin composition pellet was obtained.
Melt kneading:
Equipment: NCM60 manufactured by Kobe Steel, Ltd. Chamber temperature: 200 ° C
Rotor rotation speed: 500 rpm Resin temperature: 200 ° C
Screw speed of extruder: 25rpm
Next, wire coating molding was performed under the following conditions using the obtained polypropylene resin composition.
Wire coating molding:
Equipment: Nippon Steel Works, Ltd .: Electric wire coating machine Cylinder setting temperature: 230 ° C
Core wire: 0.9mmφ annealed copper wire Coating thickness: 0.15mm
Molding speed: 100 m / min Core wire preheating: 120 ° C

[Evaluation]
B) Tensile breaking elongation In the evaluation of the tensile breaking elongation of the wire-coated extrusion-molded body, a coated wire having a length of 150 mm was used, the core wire was pulled out and only the coating layer was taken out and used as a sample. Per minute. The tensile elongation at break is calculated from the following formula based on the rate of change of the distance between the grippers at the breaking point.
Elongation at break = (Distance between grips at break point−100) / 100 × 100 [%]
(B) Bending whitening The state of whitening when a coated electric wire having a length of 150 mm was wound around a metal cylinder having a smooth surface having a diameter of 5 mm was visually evaluated. The evaluation results in the table represent the following states.
○: Little whitening and hardly noticeable
○-: Slight whitening occurs but no problem △: Whitening or slightly conspicuous problem △-: Whitening is noticeable ×: Extremely whitening c) Oxygen index (conforms to JIS K7201)
The composition pellets were press-molded, and a specimen having a shape IV (hot press product; 3 mm thick sheet) of a test piece was prepared and evaluated using a 3 mm thick press sheet.
D) Wire-covering moldability The appearance of the obtained molded product was visually observed and evaluated according to the following criteria.
○: Extrusion appearance is good Δ: Extrusion appearance is slightly poor ×: Extrusion appearance is poor Table 3 shows the blending and various evaluation results.

[Example 2]
Granulation, molding, and evaluation were performed under the same conditions as in Example 1 except that 70 parts by weight of the component (B) magnesium hydroxide (Kyowa Chemical Co., Ltd., Kismer 5A) was used. Table 3 shows the composition and various evaluation results.
[Examples 3 to 8]
The same composition as in Example 1 except that the propylene-ethylene polymer obtained in the production example as shown in Component (A) in Table 3 was used as the component (A) PP-1 in Example 1. Granulation, molding and evaluation were performed under the conditions of Table 3 shows the composition and various evaluation results.

[Comparative Examples 1-8]
Granulation and molding under the same conditions as in Example 1 except that the propylene-ethylene copolymer obtained in the production example as shown in Table 1 was used as the component (A) in Example 1. And evaluated. Table 4 shows the formulation and various evaluation results.
[Comparative Example 9]
Granulation, molding, and evaluation were performed under the same conditions as in Example 1 except that 40 parts by weight of the component (B) magnesium hydroxide (Kyowa Chemical Co., Ltd., Kismer 5A) in Example 1 was used. . Table 4 shows the formulation and various evaluation results.
[Comparative Example 10]
Granulation, molding, and evaluation were performed under the same conditions as in Example 1 except that 400 parts by weight of the component (B) magnesium hydroxide (Kyowa Chemical Co., Ltd., Kismer 5A) in Example 1 was used. . Table 4 shows the formulation and various evaluation results.
[Comparative Example 11]
Using the propylene-ethylene copolymer (PP-11) obtained in Production Example A-11 as the component (A), Tuftec M1943 (manufactured by Asahi Kasei Co., Ltd.) as an incompatible elastomer to improve the tensile elongation at break. Hydrogenated styrene-based thermoplastic elastomer modified type MFR 8 g / 10 min / density 0.90 g / cm ³ , tensile elastic modulus 6.9 MPa) 35 parts by weight and magnesium hydroxide (Kyowa Chemical Co., Ltd., Kismer 5A) 200 parts by weight Except for the above, granulation, molding and evaluation were carried out under the same conditions as in Example 1 except for the above. Table 4 shows the formulation and various evaluation results.

[Consideration of results of Examples and Comparative Examples]
In each of Examples 1 to 8 that satisfy all the requirements of the configuration of the present invention, the oxygen index is 23 for only Example 2 and exhibits good self-extinguishing properties, and the other examples have an oxygen index of 30. There is a very good self-extinguishing property. In each example, the tensile elongation at break was about 400% or more, showing exceptionally excellent tensile characteristics, all whitening resistance was good, and there were very few cracks and whitening when bent, and it was represented by wire coating formability. The moldability is excellent, and the results are good.
On the other hand, Comparative Example 1 does not contain a low-crystalline resin component and the peak temperature of DMA is higher than 0 ° C., so that the tensile properties and whitening resistance are inferior. In Comparative Example 2, the component (A2) Since the ethylene content is too high and there are multiple DMA peaks, the resin components are phase-separated and the whitening resistance is very poor.
In Comparative Example 3, since the elution peak temperature of component (A1) and 99% elution temperature are too high, the whitening resistance is very poor. In Comparative Example 4, the elution peak temperature of component (A2) is too high. The whitening resistance is inferior.
In Comparative Example 5, since the component (A2) has too much ethylene content, the whitening resistance is very inferior. In Comparative Example 6, the amount ratio of the component (A2) is too high, so the molding process is very poor. .
In Comparative Example 7, since the elution peak temperature and 99% elution temperature of the component (A1) are too high, the whitening resistance is inferior. In Comparative Example 8, the elution peak temperature and 99% elution temperature are too high, so that molding is performed. Workability is very poor and inferior in whitening resistance.
In Comparative Example 9, since the blending amount of the inorganic flame retardant is too small, the self-extinguishing property is inferior. In Comparative Example 10, the blending amount of the inorganic flame retardant is too large, so that the tensile characteristics and the whitening resistance are very high. Comparative Example 11 does not contain a low-crystalline resin component, and since the DMA peak temperature is higher than 0 ° C., an incompatible elastomer is added to improve the tensile elongation at break. Even so, the whitening resistance is very poor.
From the control results of the above examples and comparative examples, the self-extinguishing polypropylene resin composition of the present invention is far superior in self-extinguishing properties and performances to conventional materials, and the requirements of the constitution of the present invention Has proved its rationality and significance, and its superiority over the prior art has been clarified.

Claims (6)

It consists of 100 parts by weight of a propylene-ethylene copolymer component (A) satisfying the following conditions (i) to (ii) and 50 to 300 parts by weight of a metal hydrate component (B). Polypropylene-based resin composition for extinct molded articles.
(I) In the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), the peak due to the glass transition observed in the temperature range of −60 to 20 ° C. is a single peak. The temperature is 0 ° C or lower.
(Ii) TREF elution curve obtained as a plot of elution amount (dwt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. Satisfying the following conditions (ii-A) to (ii-C) (ii-A) Two peaks are observed in the elution curve, and the peak T (A1) observed on the high temperature side is 65 to 95 ° C. The peak T (A2) observed on the low temperature side is below 45 ° C. (ii-B) By the temperature T (A3) at the midpoint between both T (A1) and T (A2) peaks The amount W (A2) of the component (A2) to be eluted is 5 to 70 wt%, and the component is a propylene / ethylene random copolymer containing 6 to 15 wt% of ethylene (ii-C) T (A3) Of ingredients that elute in The amount W of the component (A1) eluting after exit (A1) is 95~30wt%, it said component is a propylene-ethylene random copolymer containing 0～6Wt% ethylene The polypropylene resin composition for self-extinguishing molded articles according to claim 1, wherein the propylene-ethylene copolymer component (A) satisfies the following condition (iii).
(Iii) Using a metallocene catalyst, 95 to 30 wt% of a crystalline propylene-ethylene random copolymer component (A1) having an ethylene content of 0 to 6 wt% in the first step, and an ethylene content of 6 to 6 in the second step It is obtained by sequentially polymerizing 15 wt% of low crystalline propylene-ethylene random copolymer component (A2), 5 to 70 wt%. The polypropylene resin composition for a self-extinguishing molded article according to claim 1 or 2, wherein the component (A) satisfies the following condition (iv).
(Iv) TREF elution curve obtained as a plot of elution amount (dwt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. Satisfying the following conditions (iv-A) to (iv-D): (iv-A) Two peaks are observed in the elution curve, and the peak T (A1) observed on the high temperature side is 65 to 88 ° C. The peak T (A2) observed on the low temperature side is at 45 ° C. or lower (iv-B) The temperature T (A4) at which 99 wt% elutes is 90 ° C. or lower, and from the peak T (A1) The temperature difference ΔT (T (A4) −T (A1)) up to T (A4) is 5 ° C. or less (iv−C) The temperature T (T) between the T (A1) and T (A2) peaks. Amount W of component (A2) eluted by A3) 2) is 30 to 70 wt%, and the component is a propylene / ethylene random copolymer containing 8 to 14 wt% of ethylene (iv-D) A component that elutes after elution of a component that elutes by T (A3) The amount W (A1) of (A1) is 70 to 30 wt%, and the component is a propylene / ethylene random copolymer containing 1 to 5 wt% of ethylene. The polypropylene resin for a self-extinguishing molded article according to any one of claims 1 to 3, wherein the metal hydrate of component (B) is aluminum hydroxide and / or magnesium hydroxide. Composition. The self-extinguishing molded object formed by shape | molding the polypropylene resin composition for self-extinguishing moldings in any one of Claims 1-4. The self-extinguishing molded article according to claim 5, wherein the self-extinguishing molded article is produced by extrusion molding.