JP2006083322A - Crosslinked thermoplastic flame-retardant resin composition, method for producing the same and its molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crosslinked thermoplastic flame-retardant resin composition having suppressed deterioration in crosslinking with an organic peroxide, efficiently developing a physical property improving effect by crosslinking, remarkably reducing the adhesion to a kneader to improve the productivity, giving a molded article having suppressed stickiness, having excellent acid resistance, high flame-retardance and high rated temperature and suitable as a coating material for a halogen-free electric wire and provide its production method and molded article. <P>SOLUTION: The crosslinked thermoplastic flame-retardant resin composition is produced by melting and kneading (A) 100 pts. mass of a thermoplastic resin composition composed of 5-95 mass% crystalline polyolefin having a peak top melting point of 120-150°C at the highest temperature side of a DSC melting curve and 95-5 mass% at least one kind of resin such as a resin containing hydrophilic functional group, an ethylene-α-olefin copolymer and a hydrogenated block copolymer, (B) 10-300 pts.mass of aluminum hydroxide and (C) 0.001-2 pts.mass of an organic peroxide having a 1-min half-life temperature of ≤165°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a crosslinked thermoplastic flame retardant resin composition, a method for producing the same, and a molded article thereof, and particularly relates to a crosslinked thermoplastic flame retardant resin composition having excellent manufacturability and acid resistance, a method for producing the same, and a molded article thereof.

  In recent years, a crosslinked product of a thermoplastic resin has been used as a product obtained by improving the oil resistance and heat resistance of a conventional thermoplastic resin that has not been crosslinked. Among these, thermoplastic elastomers are soft materials that exhibit rubber elasticity without the need for a vulcanization process, and can be applied to various molding processes similar to thermoplastic resins, and can be recycled. It is widely used in the fields of home appliance parts, electric wire coverings, medical parts, footwear, sundries, etc.

Among thermoplastic elastomers, olefin-based thermoplastic elastomers that represent olefin-based copolymers, styrene-butadiene block copolymers (SBS) and styrene-isoprene blocks, which are block copolymers of aromatic vinyl compounds-conjugated diene compounds Polystyrene thermoplastic elastomers such as copolymers (SIS) are rich in flexibility, have good rubber elasticity at room temperature, and thermoplastic elastomer compositions obtained from these have excellent processability, and Widely used as a substitute for vulcanized rubber.
In addition, an elastomer composition obtained by hydrogenating an intramolecular double bond of a block copolymer of styrene and a conjugated diene in the styrenic thermoplastic elastomer is an elastomer having improved heat aging resistance (thermal stability) and weather resistance. More widely used.

However, thermoplastic elastomer compositions using these hydrogenated block copolymers still have rubber-like properties such as oil resistance, heat / pressure deformation rate (compression permanent strain, heat deformation rate) and rubber elasticity at high temperatures. In order to improve this point, a crosslinked product obtained by crosslinking a composition containing a hydrogenated derivative of the block copolymer has been proposed (see, for example, Patent Documents 1 to 5). .
However, the hydrogenated block copolymer cross-linking composition disclosed in the above publication increases the temperature exceeding 165 ° C. due to the decomposition temperature of the peroxide during melt kneading. Degradation of the agent and filler also occurs remarkably, this counteracts the effect of cross-linking, the effect of improving oil resistance and heat resistance is insufficient, the surface of the molded product is sticky, the productivity of the composition and There are problems in processability such as extrusion moldability, injection moldability, and blow moldability. The olefin thermoplastic elastomer has the same problem as the styrene thermoplastic elastomer.

Furthermore, as a thermoplastic resin composition used for applications such as coating materials for electric wires and cables that are required to be flame retardant, and building materials such as wallpaper, polyvinyl chloride resin (PVC) compositions and halogens can be used. Resin compositions containing flame retardants have been mainly used, but in recent years, flame retardant resin compositions containing no halogen have attracted attention due to the growing discussion of environmental problems.
In order to impart flame retardancy to these halogen-free resin compositions, a method in which the resin composition is dynamically crosslinked in the presence of an organic peroxide, in particular, a resin composition containing a flame retardant is treated with an organic peroxide. A method of dynamically crosslinking in the presence of an oxide has been developed. For example, a method of crosslinking a polypropylene / hydrogenated styrene / conjugated diene block copolymer composition with an organic peroxide (see, for example, Patent Document 6), a polyethylene / hydrogenated styrene / conjugated diene block copolymer composition, A method of crosslinking with an organic peroxide (for example, see Patent Document 7), a polyethylene / polypropylene / ethylene / vinyl acetate copolymer or a hydrogenated styrene / conjugated diene block copolymer composition is crosslinked with an organic peroxide. A method (for example, see Patent Document 8), a method of crosslinking a hydrogenated styrene / conjugated diene block copolymer / softener / flame retardant / peroxide-crosslinked polyolefin / peroxide-decomposable polyolefin composition with an organic peroxide. (For example, refer to Patent Document 9).

  However, the dynamic cross-linking tends to be higher than the set temperature due to the rapid reaction caused by radicals generated by the organic peroxide and the shear heat generation in the kneader that performs the dynamic cross-linking, and the resin temperature becomes high. As a result, there is a problem that the resin, the additive, and the filler are easily deteriorated. In addition, when there are many resins that are cross-linked by organic peroxides, poor winding around the kneading roll occurs during kneading, and further, resins that decompose by organic peroxides, ethylene / vinyl acetate copolymers, ethylene / (meth) When there are many adhesive resins such as acrylate copolymers, acid-modified polyolefins, and ionomers, there has been a problem of reduced productivity due to poor discharge (metal peelability) from the kneader of the crosslinked resin.

Magnesium hydroxide has been used from the viewpoint of heat resistance in such dynamically crosslinked flame retardant resin compositions, particularly those having high flame retardancy. Aluminum hydroxide could not be used industrially because it may be decomposed and foamed at the time of molding a compound or product. In other words, products using aluminum hydroxide have low flame retardancy and are limited to those with a low rated temperature (70 ° C. at the highest). On the other hand, non-halo electric wires have begun to spread rapidly in recent years, and at the same time, long-term reliability has been pointed out assuming a poor use environment. The trouble that is often pointed out is acid resistance. Magnesium hydroxide is also present in the air very stably, but it is weak but is an alkaline substance, so that it decomposes rapidly in the presence of water and carbon dioxide. Further, even concrete containing a weak alkali calcium silicate as a main component is deteriorated in the presence of water and carbon dioxide, which is a social problem, which is a risk that cannot be ignored.
JP 59-6236 A JP-A 63-57662 Japanese Patent Publication No. 3-49927 Japanese Patent Publication No. 3-11291 Japanese Patent Publication No. 6-13628 JP 58-98347 A JP 59-105040 A JP 63-172753 A Japanese Patent Laid-Open No. 11-256004

  In view of the above problems, the present invention can suppress deterioration of resins, additives, and fillers at the time of crosslinking with an organic peroxide, and can effectively bring out (i) physical property improvement effects by crosslinking. , (Ii) can improve productivity by reducing the adhesion to the kneader, (iii) has the advantages of suppressing the stickiness of the surface of the molded product, has excellent acid resistance, and flame retardant An object of the present invention is to provide a crosslinked thermoplastic flame retardant resin composition that is suitable as a covering material for non-halo electric wires having a high rated temperature and a high rated temperature, a production method thereof, and a molded body thereof.

  As a result of intensive studies to achieve the above object, the present inventor has melt-kneaded a thermoplastic resin composition using a specific crystalline polyolefin, aluminum hydroxide, and a specific organic peroxide. It is possible to obtain a partially crosslinked resin composition at low temperature, and it is excellent in low cost and environmental resistance with improved productivity due to deterioration of resin, additives and fillers during manufacture of the resin composition and reduction in adhesion to the kneader. The present inventors have found that a dynamically crosslinked thermoplastic flame retardant resin composition can be obtained.

That is, according to the first invention of the present invention, (A) at least one resin selected from the following (A-1) 5 to 95% by mass and the following (A-2) to (A-6): 100 parts by mass of a thermoplastic resin composition comprising 95 to 5% by mass,
(B) A crosslinked thermoplastic flame retardant resin obtained by melt-kneading 10 to 300 parts by mass of aluminum hydroxide and (C) 0.001 to 2 parts by mass of an organic peroxide having a 1 minute half-life temperature of 165 ° C. or less. A composition is provided.
(A-1) Crystalline polyolefin having a peak top melting point on the highest temperature side of the DSC melting curve of 120 to 150 ° C. (A-2) Thermoplastic resin having a hydrophilic functional group (A-3) Ethylene and α- Olefin copolymer (A-4) At least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound. Hydrogenated block copolymer (A-5) obtained by hydrogenation of a block copolymer comprising: a hydrogenated copolymer (A-) mainly comprising a random structure of an aromatic vinyl compound and a conjugated diene compound 6) Non-halogen non-crosslinked rubber

That is, according to the second invention of the present invention, in the first invention, the crosslinked thermoplasticity characterized by satisfying the following physical properties (i) to (v) measured according to JIS K 6723: A flame retardant resin composition is provided.
(I) Maximum tensile stress is 8 MPa or more (ii) Maximum tensile elongation is 200% or more (iii) Maximum tensile stress residual ratio after heat treatment is 80% or more (iv) Maximum tensile elongation residual ratio after heat treatment is 80% (V) Heat deformation rate is 40% or less

  Moreover, according to 3rd invention of this invention, (A) 10-300 mass parts and (C) 0.001-2 mass parts are mix | blended with respect to 100 mass parts of thermoplastic resin compositions, There is provided a method for producing a crosslinked thermoplastic flame retardant resin composition of the first or second invention, characterized by melt-kneading at 165 ° C. or lower.

  Moreover, according to 4th invention of this invention, the molded object which consists of a crosslinked thermoplastic flame-retardant resin composition of 1st or 2nd invention is provided.

  The crosslinked thermoplastic flame retardant resin composition of the present invention is a crosslinked thermoplastic flame retardant resin composition that is excellent in acid resistance, has high flame retardancy, and can be used for coating electric wires with a high rated temperature. Excellent formability and workability of blow moldability.

The crosslinked thermoplastic flame retardant resin composition, production method, and use constituting the present invention will be described in detail below.
1. Component (A) Thermoplastic Resin Composition of Crosslinked Thermoplastic Flame Retardant Resin Composition (A) The thermoplastic resin composition used in the crosslinked thermoplastic flame retardant resin composition of the present invention is the following (A-1): It is a resin composition of crystalline polyolefin and at least one kind of resin selected from the following (A-2) to (A-6).

(A-1) Crystalline polyolefin (A-1) The crystalline polyolefin used in the present invention has a peak top melting point on the highest temperature side of the DSC melting curve of 120 to 150 ° C, preferably 125 to 150 ° C. Preferably it is a crystalline polyolefin of 130-140 degreeC. The peak at the highest temperature side is usually the largest peak at the same time, but when the highest peak is present on the lower temperature side, the peak top temperature is also 120 ° C. or higher, more preferably 125 ° C. or higher. Is preferably 130 ° C. or higher. That is, it is preferable that the peak on the highest temperature side is at 150 ° C. or lower and the largest peak is at 120 ° C. or higher.
By setting the temperature of the peak top melting point on the highest temperature side of the DSC melting curve within the above range, a crosslinked thermoplastic resin composition excellent in heat resistance without causing decomposition of aluminum hydroxide, for example, a rated 90 ° C. type A crosslinked thermoplastic resin composition that can be used as a wire covering material is obtained. When the peak top melting point on the highest temperature side of the DSC melting curve is less than 120 ° C., the heat deformation resistance and the stress crack resistance are insufficient. On the other hand, if it exceeds 150 ° C., aluminum hydroxide cannot be used.
Here, the peak top melting point on the highest temperature side of the DSC melting curve is 0 ° C. at a temperature decreasing rate of 10 ° C./min after holding the measurement sample at 230 ° C. for 5 minutes using a differential scanning calorimeter (DSC). It is a value obtained from the peak top position on the highest temperature side in the melting curve drawn when the temperature is further lowered to 230 ° C. and further maintained at 0 ° C. for 5 minutes and then heated to 230 ° C. at a rate of 10 ° C./min. .

Examples of the crystalline polyolefin that satisfies such conditions include polypropylene resins and polyethylene resins.
Examples of the polypropylene-based resin include crystalline propylene homopolymers (stereoregularity controlled) and crystalline propylene / α-olefin copolymers. As crystalline propylene / α-olefin copolymers, A propylene random copolymer of propylene and a small amount of an α-olefin such as ethylene, 1-butene and the like can be mentioned. Examples of the polyethylene resin include low density polyethylene, linear low density polyethylene, and high density polyethylene, and linear low density polyethylene polymerized with a metallocene catalyst is preferable. Among these, a polypropylene resin is particularly preferable because it easily maintains thermoplasticity.

Moreover, MFR (230 degreeC, 21.18N load) of the said polypropylene resin becomes like this. Preferably it is 0.5-50 g / 10min, More preferably, it is 1-30 g / 10min. Furthermore, MFR (190 degreeC, 21.18N load) of a polyethylene-type resin becomes like this. Preferably it is 0.5-50 g / 10min, More preferably, it is 1-30 g / 10min. In any resin, if the MFR is less than the lower limit, the moldability tends to be insufficient, and if the MFR exceeds the upper limit, the heat deformation resistance and the stress crack resistance tend to be insufficient.
Here, MFR is a value measured according to JIS K 7210.

(A-2) Thermoplastic resin having a hydrophilic functional group (A-2) The thermoplastic resin having a hydrophilic functional group used in the present invention is composed of an α-olefin, carbon, hydrogen, and oxygen atoms. And a copolymer with a monomer containing a hydrophilic functional group, a polyethylene resin, a resin obtained by modifying a polypropylene resin with a monomer containing a hydrophilic functional group, and the like. In the copolymer resin, the content of the monomer containing a hydrophilic functional group is preferably 5 mol% or more, more preferably 10 mol% or more.
Specific preferred resins include ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene- (meth) acrylic acid copolymer, maleic anhydride-modified polyethylene resin, maleic anhydride Examples thereof include modified polypropylene resins.
In the above ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, and ethylene- (meth) acrylic acid ester copolymer, the MFR (190 ° C., 21.18 N load) is 10 g. / 10 minutes or less is preferable, more preferably 5 g / 10 minutes or less, and still more preferably 0.1 to 2 g / 10 minutes. If the MFR is too high, it will be difficult to maintain the tensile strength and tensile elongation, and if it is less than 0.1 g / 10 min, the moldability of the thermoplastic resin composition may be insufficient.
Here, MFR is a value measured according to JIS K 6924-2.

  Here, examples of the (meth) acrylic acid ester in the ethylene- (meth) acrylic acid ester copolymer include alcohols having 1 to 8 carbon atoms and (meth) acrylic acid esters. Examples include methyl (meth) acrylate, ethyl (meth) acrylate, (n-butyl) (meth) acrylate, t-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

The ethylene-vinyl acetate copolymer, the ethylene- (meth) acrylic acid copolymer, and the ethylene- (meth) acrylic acid ester copolymer have a COOR type functional group contained in (i) desorbed during thermal decomposition. A carbonic acid reaction occurs and CO ₂ is produced as it is. In other words, non-flammable gas is generated without releasing combustion energy. (Ii) Since it is hydrophilic, the interfacial strength of the inorganic flame retardant with aluminum hydroxide is high, and even if a large amount of inorganic flame retardant is added, the degree of physical property deterioration is reduced. Small (iii) Non-halogen flame retardant in that the comonomer copolymerized with ethylene is bulky, so that the acceptability of inorganic flame retardant is high, and the degree of physical deterioration is small even when a large amount of inorganic flame retardant is added. It is a resin that is advantageous as a base material of the conductive resin composition. Further, the present invention is characterized in that a crosslinked resin composition is produced by melt kneading at a low temperature, and there is a disadvantage that productivity is lowered due to the expression of adhesiveness during production of the composition by using these resins. Can be suppressed.

(A-3) Copolymer of ethylene and α-olefin (A-3) The copolymer of ethylene and α-olefin used in the present invention is mainly a low crystallinity copolymer, ethylene propylene. Examples include copolymers, ethylene / 1-butene copolymers, ethylene / propylene / non-conjugated diene copolymers, ethylene / 1-hexene copolymers, ethylene / 1-octene copolymers, and the like.

(A-4) A block copolymer comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound. Hydrogenated block copolymer obtained by hydrogenation of polymer (A-4) used in the present invention is mainly composed of an aromatic vinyl compound as an aromatic vinyl compound-conjugated diene block copolymer. A hydrogenated product of a block copolymer comprising at least one polymer block A and at least one polymer block B mainly composed of a conjugated diene compound. For example, a hydrogenated aromatic vinyl compound-conjugated diene compound block copolymer having a structure such as A-B, A-B-A, B-A-B-A, or A-B-A-B-A. Can be mentioned.

The polymer block A mainly composed of an aromatic vinyl compound is preferably composed only of an aromatic vinyl compound, or an aromatic vinyl compound of 50% by mass or more, preferably 70% by mass or more, and an optional component such as a conjugated diene compound. And a copolymer block.
The polymer block B mainly composed of a conjugated diene compound is preferably composed of only a conjugated diene compound, or an optional component such as a conjugated diene compound of 50% by mass or more, preferably 70% by mass or more and an aromatic vinyl compound. The copolymer block.
In addition, the said block copolymer contains 5-60 mass% of aromatic vinyl compounds, for example, Preferably it contains 20-50 mass%.

  Further, in the polymer block A mainly composed of these aromatic vinyl compounds and the polymer block B mainly composed of conjugated diene compounds, the distribution of units derived from the conjugated diene compound or aromatic vinyl compound in the molecular chain is random, It may be tapered (in which the monomer component increases or decreases along the molecular chain), partially in a block form, or any combination thereof. When there are two or more polymer blocks A mainly composed of aromatic vinyl compounds or polymer blocks B mainly composed of conjugated diene compounds, each polymer block has a different structure even if each has the same structure. There may be.

  As the aromatic vinyl compound constituting the block copolymer, for example, one or more kinds can be selected from styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, etc. preferable. In addition, as the conjugated diene compound, for example, one or two or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., among which butadiene, isoprene and These combinations are preferred.

  Specific examples of the hydrogenated block copolymer include styrene-ethylene / butene / styrene copolymer (SEBS), styrene / ethylene / propylene / styrene copolymer (SEPS), and styrene / ethylene / ethylene / propylene / styrene. Examples thereof include a copolymer (SEEPS), a partially hydrogenated styrene-butadiene-styrene copolymer (SBBS), and a styrene-ethylene / butylene-ethylene copolymer (SEBC).

  The hydrogenated block copolymer is a hydrogenated block copolymer comprising a polymer block A mainly composed of an aromatic vinyl compound and a polymer block B mainly composed of a conjugated diene compound. A hydrogenated block copolymer obtained by addition may be one in which the molar ratio between the number of ethylene unit structures generated by hydrogenation and the number of linear α-olefin unit structures is 2 or less. In this case, the content of the aromatic vinyl compound is 50% by mass or less, preferably 5 to 35% by mass. If it exceeds 50% by mass, the feel of the molded product obtained becomes hard and does not meet the object of the present invention.

(A-5) Hydrogenated product of copolymer mainly composed of random structure of aromatic vinyl compound and conjugated diene compound (A-5) used in the present invention is random of conjugated diene compound and aromatic vinyl compound A copolymer having a number average molecular weight of preferably 5,000 to 1,000,000, more preferably 10,000 to 350,000, and a polydispersity (Mw / Mn) value of 10 The following is preferable.
Here, content of an aromatic vinyl compound is 50 mass% or less, Preferably, it is 5-35 mass%. If it exceeds 50% by mass, the feel of the molded product obtained becomes hard and does not meet the object of the present invention.

Examples of the aromatic vinyl compound include styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-diethyl-p-aminoethylstyrene, vinyltoluene. , P-tertiary butyl styrene, etc. can be selected from one or more types, among which styrene is preferred.
Further, as the conjugated diene compound, for example, one or two or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., among which butadiene, isoprene and These combinations are preferred.
The copolymer is preferably one in which at least 90% of the aliphatic double bonds based on the conjugated diene compound are hydrogenated.
Specific examples of the (hydrogenated) styrene / butadiene random copolymer include hydrogenated SBR (Jay Earl Dynalon 1320P).

(A-6) Non-halogen-based uncrosslinked rubber As (A-6) used in the present invention, room temperature solid polybutadiene is exemplified, and preferably, syndiotactic 1,2-polybutadiene is exemplified.

  In the thermoplastic resin composition (A) of the present invention, the composition ratio of (A-1) crystalline polyolefin and at least one resin selected from (A-2) to (A-6) is (A -1) is preferably 5 to 95% by mass, more preferably 7 to 90% by mass, particularly preferably 10 to 80% by mass, and at least one selected from (A-2) to (A-6) The type of resin is preferably 95 to 5% by mass, more preferably 93 to 10% by mass, and particularly preferably 90 to 20% by mass. When the blending amount of (A-1) is less than the lower limit, the heat deformation resistance and the stress crack resistance are insufficient, and when it exceeds the upper limit, the tensile elongation is lowered.

(B) Aluminum hydroxide In the crosslinked thermoplastic flame-retardant resin composition of the present invention, (B) aluminum hydroxide is used as a flame retardant. Aluminum hydroxide treated with various coupling agents (silane, titanium, etc.) and various surface treatment agents (fatty acids, fatty acid metal salts, etc.) may be used.
Moreover, you may perform the process by various coupling agents and surface treating agents simultaneously with manufacture of a crosslinked thermoplastic flame-retardant resin composition.
The compounding quantity of aluminum hydroxide is 10-300 mass parts with respect to 100 mass parts of (A) thermoplastic resin composition, Preferably it is 50-275 mass parts. When the blending amount is less than 10 parts by mass, the flame retardancy is not expressed, and when it exceeds 300 parts by mass, the mechanical properties are lowered and the moldability is deteriorated.

(C) Organic peroxide (C) The organic peroxide used in the crosslinked thermoplastic flame retardant resin composition of the present invention is an organic peroxide having a 1-minute half-life temperature of 165 ° C or lower. Generates radicals at a low temperature and reacts the radicals in a chain to dynamically crosslink the thermoplastic resin, thereby improving the flame retardancy, oil resistance, and heat resistance.
An organic peroxide having a lower one-minute half-life temperature can perform dynamic crosslinking at a lower kneading temperature. However, if it is too low, it is more difficult to handle as a dangerous substance stipulated in the Fire Service Law, and a lower temperature. Then, since the viscosity of the resin is too high, shear heat generation becomes large, and therefore, an organic peroxide having a 1-minute half-life temperature of 160 ° C. or lower is preferable, and an organic peroxide having a temperature of 140 to 155 ° C. is particularly preferable.

  Specific examples of the organic peroxide having a 1 minute half-life temperature of 165 ° C. or lower include, for example, 1,1-Bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane (1 minute half-life temperature 147.1 ° C.). ), 1,1-Bis (t-butylperoxy) -3,3,5-trimethylcyclohexane (1-minute half-life temperature 149.0 ° C.), Benzoyl peroxide + Benzoyl m-methylbenzoyl peroxide + m-lol1 + m-lol 1 + m-deperiod 1 + m-lol ° C), t-Hexyl peroxidebenzoate (1 minute half-life temperature 160.3 ° C), 1,1-Bis (t-butyl peroxy) 2-methylcyclohexane (1 minute half-life temperature) 142.1 ° C.), 1,1-Bis (t-hexyl peroxide) cyclohexane (1 minute half-life temperature 149.2 ° C.), 1,1-Bis (t-butyl peroxy) cyclohexane (1 minute half-life temperature 153. 8 ° C), 2,2-Bis (4,4-di-butyl peroxycyclohexyl) propane (1-minute half-life temperature 153.8 ° C.), 1,1-Bis (t-butyl peroxy) cyclodecane (1-minute half-life) Temperature 152.9 ° C.), t-Hexyl peroxide isocarboxylic monocarbonate (1 minute half-life temperature 155.0 ° C.), succinic peroxide (1 minute half-life temperature 131.8 ° C.), 1-Cyclohexyl-1-methylethyl peroxy 2-ethylhexanoate (1 min half-life temperature 137.7 ° C.), t-Hexyl peroxy 2-ethylhexanoate (1 min half-life temperature 132.6 ° C.), t-Butyl peroxy 2-ethyl hexanoate (1 min half-life temperature 134. 0 ° C.), m-Toluoyl and benzoyl peroxide (1 minute half-life temperature 131.1 ° C.), t-Butyl peroxy isobutylate (1 minute half-life temperature 136.1 ° C.), t-Butyl peroxide laurate (1 minute half-life temperature) 159.4 ° C.), 2,5-Dimethyl-2,5-di (m-toluyl peroxy) hexane (1 minute half-life temperature 156.0 ° C.), t-Butyl peroxide isopr pyl monocarbonate (1 min half-life temperature 158.8 ° C), t-Butyl peroxy 2-ethylmonocarboxyate (1 min half-life temperature 161.4 ° C), 2,5-Di-methyl-2,5-di (benzoyl peroxy) ) Hexane (1 minute half-life temperature 158.2 ° C), t-Butyl peroxyacetate (1 minute half-life temperature 159.9 ° C), 2,2-Bis (t-butyl peroxy) butane (1 minute half-life temperature 159) Among them, those having a 1 minute half-life temperature of 140 to 155 ° C. are particularly preferable.

  Examples of product names using the above compounds are Perhexa TMH (1 minute half-life temperature 147.1 ° C), Perhexa 3M (1 minute half-life temperature 149.0 ° C), Nyper BMT (1 minute) Half-life temperature 131.1 ° C), Perhexyl Z (1 minute half-life temperature 160.3 ° C), Perhexa MC (1 minute half-life temperature 142.1 ° C), Perhexa HC (1 minute half-life temperature 149.2 ° C) Perhexa C (1 minute half-life temperature 153.8 ° C.), Pertetra A (1 minute half-life temperature 153.8 ° C.), Perhexa CD (1 minute half-life temperature 152.9 ° C.), Perhexyl I (1 minute half-life) 155.0 ° C.), Perhexyl I (C) (1 minute half-life temperature 155.0 ° C.), Parroyl SA (1 minute half-life temperature 131.8 ° C.), Percyclo 0 (1 minute half-life temperature 137.7 ° C.) ) Hexyl 0 (1 minute half-life temperature 132.6 ° C), Perbutyl 0 (1 minute half-life temperature 134.0 ° C), Nyper BMT (1 minute half-life temperature 131.1 ° C), Perbutyl IB (1 minute half-life temperature 136.1 ° C), Perbutyl L (1 minute half-life temperature 159.4 ° C), Perhexa 25MT (1 minute half-life temperature 156.0 ° C), Perbutyl I (1 minute half-life temperature 158.8 ° C), Perbutyl E (1 minute half-life temperature 161.4 ° C), Perhexa 25Z (1 minute half-life temperature 158.2 ° C), Perbutyl A (1 minute half-life temperature 159.9 ° C), Perhexa 22 (1 minute half-life temperature 159. 9 ° C.). Kayaku Akzo Co., Ltd. also has an equivalent product.

  The compounding quantity of an organic peroxide is 0.001-2 mass parts with respect to 100 mass parts of (A) thermoplastic resin compositions, Preferably it is 0.005-1 mass parts. If the blending amount is less than 0.001 part by mass, the crosslinking cannot be sufficiently achieved, and if it exceeds 2 parts by mass, the crosslinking proceeds too much and the thermoplasticity is lost.

(D) Crosslinking aid (D) A crosslinking aid can be used for the crosslinked thermoplastic flame-retardant resin composition of the present invention, if necessary. The crosslinking aid can be blended in the dynamic crosslinking, whereby a uniform and efficient crosslinking reaction can be performed.
Examples of the crosslinking assistant include triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate having 9 to 14 repeating units of ethylene glycol, Multifunctional methacrylate compounds such as trimethylolpropane trimethacrylate, allyl methacrylate, 2-methyl-1,8-octanediol dimethacrylate, 1,9-nonanediol dimethacrylate, polyethylene glycol diacrylate, 1,6-hexanediol Multifunctional acrylates such as diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate Things, may be mentioned polyfunctional vinyl compounds such as vinyl butyrate or vinyl stearate. You may use these individually or in combination of 2 or more types. Of the above-mentioned crosslinking aids, polyfunctional acrylate compounds or polyfunctional methacrylate compounds are preferred, and triethylene glycol dimethacrylate and tetraethylene glycol dimethacrylate are particularly preferred. These compounds are easy to handle, have an organic peroxide solubilizing action, and act as a dispersion aid for the organic peroxide, so that the crosslinking can be made uniform and effective.

  When blending, the blending amount of the crosslinking aid is preferably 0.001 to 4 parts by mass, more preferably 0.005 to 4 parts by mass with respect to 100 parts by mass of the (A) thermoplastic resin composition. . Below the lower limit, the crosslinking reaction is not sufficient. On the other hand, when the upper limit is exceeded, the crosslinking proceeds too much, and the dispersion of the crosslinked product becomes worse. Further, the blending amount of the crosslinking aid is preferably 1.5 to 4 times the blending amount of the organic peroxide.

(E) Non-aromatic rubber softener In the crosslinked thermoplastic flame retardant resin composition of the present invention, (E) a non-aromatic rubber softener can be used as necessary. Examples of component (E) include non-aromatic mineral oils or liquid or low molecular weight synthetic softeners. The mineral oil softener used for rubber is a mixture of the aromatic ring, naphthene ring, and paraffin chain, and the paraffin chain carbon number accounts for 50% or more of the total carbon number. A naphthene ring having 30 to 40% carbon atoms is distinguished by being called a naphthene type, and those having 30% or more aromatic carbon number being called aromatic.

  The mineral oil rubber softeners used as non-aromatic rubber softeners in the present invention are classified into paraffinic and naphthenic ones. Aromatic softeners are not preferred because their use makes thermoplastic resins soluble, inhibits the crosslinking reaction, and cannot improve the physical properties of the resulting composition. As the non-aromatic rubber softener of the present invention, paraffin-based ones are preferable, and paraffin-based ones having less aromatic ring components are particularly suitable.

  These non-aromatic rubber softeners have a dynamic viscosity at 37.8 ° C. of 20 to 50,000 cSt, preferably 20 to 1,000 cSt, and a dynamic viscosity at 100 ° C. of 5 to 1,500 cSt. Preferably, it is 5 to 100 cSt, the pour point is -10 to -25 ° C, and the flash point (COC) is 170 to 350 ° C. Furthermore, a thing with a weight average molecular weight of 100-2,000 is preferable.

  The blending amount of the non-aromatic rubber softener is preferably limited to a range that does not cause bleed-out to the surface of the molded product, and is determined in consideration of miscibility (holding ability) with the thermoplastic resin component. Particularly preferred.

(F) Other components In the composition of the present invention, various antioxidants such as phosphorus-based, phenol-based, sulfur-based, anti-aging agent, light, etc., as long as the object of the present invention is not impaired. Various weathering agents such as stabilizers, UV absorbers, copper damage prevention agents, modified silicone oils, silicone oils, waxes, acid amides, fatty acids, fatty acid metal salts, various lubricants, aromatic phosphate metal salts, gelols, etc. Various nucleating agents, various plasticizers such as glycerin fatty acid ester, aromatic paraffin oil, phthalic acid, ester, various fillers such as magnesium oxide, zinc oxide, calcium carbonate, talc, various colorants, etc. Additives and the like can be used. In order to prevent troubles such as bleeding out on the surface of the molded product, those having high compatibility with the crosslinked thermoplastic resin composition of the present invention are preferred.

2. Production of Crosslinked Thermoplastic Flame Retardant Resin Composition The crosslinked thermoplastic flame retardant resin composition of the present invention is obtained by adding (C) an organic peroxide to (A) the thermoplastic resin composition, (B) aluminum hydroxide, Alternatively, it can be obtained by adding the above-mentioned optional components, if necessary, dry blending at room temperature, heat melting and kneading with a kneader to perform dynamic crosslinking.
The melt kneading temperature is preferably at least 1 minute half-life temperature of the peroxide, preferably 1 minute half-life temperature + 5 ° C. or more in order to completely terminate the crosslinking reaction (completely decompose the peroxide), And it is preferable to complete | finish at the resin temperature of 165 degrees C or less. If the temperature of the melt kneading exceeds 165 ° C., the resin, additives and fillers are liable to deteriorate, and if there are many resins that are cross-linked by the organic peroxide, there is a poor winding around the kneading roll during kneading. In the case where the amount of the resin and / or the adhesive resin that is decomposed by the organic peroxide is large, the productivity tends to be lowered due to poor dischargeability (metal peelability) from the kneading machine of the crosslinked resin.
Furthermore, it is necessary to produce it below the decomposition temperature of aluminum hydroxide.

  The method of melt kneading is not particularly limited, and generally known methods can be used. For example, a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, or various kneaders can be used. For example, the above operation can be continuously performed by using a suitable L / D twin screw extruder, Banbury mixer, pressure kneader, or the like. In consideration of blending a large amount of aluminum hydroxide, various kneaders such as a Banbury mixer and a pressure kneader are preferable.

3. Crosslinked thermoplastic flame retardant resin composition The crosslinked thermoplastic flame retardant resin composition of the present invention is a composition that suppresses deterioration of resin, additives, and fillers during crosslinking with organic peroxides. The improvement effect can be pulled out efficiently, the adhesion to the kneader can be reduced, the productivity can be improved, and the stickiness of the surface of the molded product can be suppressed. In addition to this effect, it is excellent in processability such as extrusion moldability, injection moldability, and blow moldability.
Moreover, since the crosslinked thermoplastic flame retardant resin composition of the present invention has excellent heat resistance and excellent flame retardancy, it is suitable for electric wires, power cords, sensor cables, acoustic cords, etc. that require flexibility and acid resistance. It can be used for coating materials, building materials such as wallpaper. In particular, it can be used as a wire covering material, particularly a high rated temperature type material (for example, 90 ° C. rated).
In particular, the crosslinked thermoplastic flame retardant resin composition of the present invention preferably satisfies the following physical properties (i) to (v) measured in accordance with JIS K 6723, and is difficult to crosslink for a rated 90 ° C. heat-resistant electric wire. It can be preferably used as a fuel resin composition.
(I) Tensile maximum stress is 8 MPa or more, preferably 10 MPa or more (ii) Tensile maximum elongation is 200% or more, preferably 350% or more (iii) Tensile maximum stress residual rate is 80% or more (iv) Tensile maximum elongation residual rate 80% or more (v) Heat deformation rate 40% or less

  The present invention will be specifically described by the following examples and comparative examples, but the present invention is not limited to these examples. In addition, the measuring method and sample of the physical property used by this invention are shown below.

1. Physical property measurement method and manufacturability evaluation method (1) Specific gravity: Measured according to JIS K 7112.
(2) Hardness: In accordance with JIS K 7215, a 6.3 mm thick press sheet was used as the test piece.
(3) MFR: Measured according to JIS K7210.
(4) Maximum tensile stress, maximum tensile elongation, and stress at 100% elongation: In accordance with JIS K 6723, a 1 mm thick press sheet was punched into a No. 2 dumbbell-type test piece and used. The tensile speed was 200 mm / min (room temperature).
(5) Tensile maximum stress residual rate and tensile maximum residual elongation rate after heat treatment: In accordance with JIS K 6723, a 1 mm thick press sheet was punched into a No. 2 dumbbell-type test piece and used. After heat treatment at 120 ° C. for 96 hours, a tensile test was performed at a tensile speed of 200 mm / min.
(6) Heat deformation: In accordance with JIS K 6723, measurement was performed by treating for a specified time at a constant temperature of 120 ° C. and a load of 1000 g.
(7) Chemical resistance (hydrochloric acid aqueous solution): In the oil resistance test of ASTM D471, all oils were measured under the same conditions except that the oil was changed to a 1 mol /% hydrochloric acid aqueous solution and the immersion conditions were room temperature x 14 days.
(8) Chemical resistance (sulfuric acid aqueous solution): In the oil resistance test of ASTM D471, all oils were measured under the same conditions except that the oil was changed to a 1 mol /% sulfuric acid aqueous solution and the immersion conditions were room temperature × 14 days.
(9) Chemical resistance (sodium hydroxide aqueous solution): The same except that the oil was changed to a 0.7 mol /% sodium hydroxide aqueous solution in the oil resistance test of ASTM D471 and the immersion conditions were changed to room temperature × 14 days. Measured under conditions.
(10) Sweating phenomenon: Put a chemical in a 500 cc beaker to a depth of 5 mm, place a 2 mm thick press sheet on it, cover it, observe the appearance after 24 hours at room temperature, and evaluate it according to the following criteria: . As chemicals, a bond for woodworking (commercial product of acetic acid emulsion system: product of Konishi Co., Ltd.) and a 1 mass% acetic acid aqueous solution were used.
None: No sweating phenomenon is observed.
X: A little sweating phenomenon is recognized.
XX: A sweating phenomenon is observed on the entire press sheet.
(11) Physical properties of extruded 40φ sheet: The resin temperature was set to C1 / C2 / C3 / A / D = 140/160/170/170/170 ° C., and the appearance of the extruded sheet was observed when the sheet was extruded at 30 rpm. Judgment was based on the following criteria.
Good: Surface is smooth (in most cases, glossy), edge of sheet end comes out, no foaming, no defects such as poor melting, no gel ×: Good condition not satisfied (12) Manufacturability: Melting The manufacturability of the composition during kneading was evaluated as follows. Here, the kneading temperature is the resin temperature at discharge.
(I) Discharge: The situation in the discharge process from the pressure kneader was evaluated according to the following criteria.
Good: No trouble Bad: The kneaded material does not stick to the kneading blades and the kneading tank wall and does not discharge (ii) Kneaded material properties during discharging Properties: The resin composition at the time of discharging was visually evaluated according to the following criteria.
Good: Sticky feeling and no adhesion to the kneading blade and kneading tank Viscosity: Adhesion to the kneading blade and kneading tank Looseness: No feeling of stickiness and its state (iii) Roll workability: Kneading to the roll The adhesion state of the object was visually judged according to the following criteria.
Good: The kneaded material does not stick to the roll surface (a state having an appropriate viscosity).
Peeling failure: The kneaded product is too viscous and sticks to the roll surface, and the work cannot be wound. Wrapping failure: The kneaded product does not wind around the roll and cannot work (iv). The obtained resin composition was granulated by a hot cut method using a twin screw extruder manufactured by Nakatani, and the pelletized state was evaluated according to the following criteria.
Good: Can be pelletized as usual Cannot be manufactured: Pellets and pellets are re-fused to agglomerate

2. Samples used in Examples and Comparative Examples (A) Thermoplastic resin compositions (A-1) Crystalline polyolefin (i) Linear low density polyethylene (MeLLDPE) using metallocene catalyst: SP2520 (Mitsui Sumitomo Polyolefin) density 928 Kg / m ³ , MFR 4 g / 10 min, peak top melting point 121 ° C. on the highest temperature side of the DSC melting curve
(Ii) Polypropylene random copolymer (R-PP): FW3E (manufactured by Nippon Polypro) MFR 7 g / 10 min, peak top melting point 140 ° C. on the highest temperature side of the DSC melting curve
(Iii) (Comparative) Polypropylene homopolymer (H-PP): EA9 (manufactured by Nippon Polypro Co., Ltd.) MFR 0.5 g / 10 min, peak top melting point 163 ° C. on the highest temperature side of the DSC melting curve
(A-2) Hydrophilic functional group-containing thermoplastic resin (i) Ethylene-vinyl acetate copolymer (EVA-1): V-220 (manufactured by Ube Industries) MFR 2.0 g / 10 min, VA content 20% by mass
(Ii) Ethylene-vinyl acetate copolymer (EVA-2): EV170 (Mitsui / DuPont Polychemical) MFR 1.0 g / 10 min, VA content 33% by mass
(Iii) Ethylene-vinyl acetate copolymer (EVA-3): Ultrasen YX21K (manufactured by Tosoh Corporation) MFR 0.4 g / 10 min, VA content 42% by mass
(Iv) Maleic anhydride-modified polyethylene (MAH-PE): Admer XE070 (Mitsui Chemicals)
(A-3) Ethylene / α-olefin copolymer (i) Ethylene / hexene-1 copolymer (C ₆ MeLL-1): KF360 (manufactured by Nippon Polyethylene) Density 898 Kg / m ³ , MFR 3.5 g / 10 Minute (ii) Ethylene / hexene-1 copolymer (C ₆ MeLL-2): KS240 (manufactured by Nippon Polyethylene) Density 880 kg / m ³ , MFR 2.2 g / 10 min (A-5) Conjugated with aromatic vinyl compound Random copolymer hydrogenated diene compound (i) SBR hydrogenated (HSBR): Dynalon 1320P (manufactured by JSR)
(B) Aluminum hydroxide (i) Aluminum hydroxide (Al (OH) ₃ ): Heidi Land H-42M (manufactured by Showa Denko KK)
(2) (Comparative) Magnesium hydroxide (Mg (OH) ₂ ): Kisuma 5L (manufactured by Kyowa Chemical Industry Co., Ltd.)
(C) Organic peroxide (i) Peroxid-1: Perhexa TMH (1,1-Bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, manufactured by NOF Corporation), 1 minute half-life temperature 147 ° C.
(Ii) Peroxid-2: Perhexa C-40 (1,1-Bis (t-butyl peroxy) cyclohexane), manufactured by Nippon Oil & Fats Co., Ltd., 1 minute half-life temperature 154 ° C., diluted silicon dioxide powder (active ingredient concentration) 40% by mass)
(Iii) (Comparative) Peroxid-3: Perhexa 25B (2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, manufactured by NOF Corporation), 1 minute half-life temperature 179 ° C.
(D) Crosslinking aid (i) Ester-based crosslinking aid: NK ester IND (manufactured by Shin-Nakamura Chemical Co., Ltd.)
(F) Silane coupling agent: SZ6030 (manufactured by Toray Dow Corning Silicone)

(Example 1, Comparative Examples 1-3)
Each component of the amount shown in Table 1 and heavy metal deactivator, oleic acid amide, metal soap, antioxidant, light stabilizer and the like are blended in a predetermined amount, and all components are dry blended at room temperature. Using a pressure kneader, melt-kneading was carried out to perform dynamic cross-linking, and discharging was performed to obtain a cross-linked thermoplastic resin composition. The melt kneading temperature is shown in Table 1 as the target resin temperature at discharge of perhexa TMH of 1 minute half-life of 147 ° C. + 5 ° C. + 165 ° C., and the measured value as the measured resin temperature at discharge.
Next, using a two-screw extruder manufactured by Nakatani, hot-cut granulation is performed at a die temperature corresponding to the resin temperature during discharge, and the resulting pellets are formed into a sheet with a roll, and further hot pressed. Test pieces were prepared and used for each test. The evaluation results are shown in Table 1.

(Examples 2 and 3)
Each test was performed in the same manner as in Example 1 except that the amounts of each component shown in Table 2 were used. The melt kneading temperature was targeted at a decomposition temperature of perhexa C of 154 ° C. + 5 ° C. to 165 ° C. The evaluation results are shown in Table 2.

(Examples 4-7, Comparative Examples 4-7)
Each test was performed in the same manner as in Example 1 except that the components shown in Tables 3 and 4 were used. The melt kneading temperature was targeted at a decomposition temperature of perhexa C of 154 ° C. + 5 ° C. to 165 ° C. The evaluation results are shown in Tables 3 and 4.

As is clear from Tables 1 to 4, Examples 1 to 7 are crosslinked thermoplastic flame retardant resin compositions of the present invention and exhibit excellent productivity and physical properties.
On the other hand, Comparative Example 1 is a case where a large amount of organic peroxide is used, and it is not wound around a roll and is difficult to manufacture industrially.
Comparative Example 2 is a case where an organic peroxide having a 1-minute half-life temperature exceeding 165 ° C. has very large problems in any of the steps of kneading, rolls, and granulation, and is substantially impossible to produce. is there.
Comparative Example 3 is a case where no organic peroxide is blended, and is difficult to produce industrially.
In Comparative Example 4, magnesium hydroxide was used instead of aluminum hydroxide, and the obtained crosslinked thermoplastic flame retardant resin composition was inferior in acid resistance.
Comparative Example 5 is a case where the peak top melting point on the highest temperature side of the DSC melting curve of (A-1) crystalline polyolefin exceeds 150 ° C. When a high melting point resin was used, it was not sufficiently kneaded at a low temperature, and a part of aluminum hydroxide foamed at a well kneaded temperature, and a resin composition could not be obtained.
Comparative Example 6 is a case where (A-1) crystalline polyolefin is not used, and tends to be inferior in heat deformation resistance. Cross-linking also progressed easily, and the appearance of the extruded sheet was poor.
Comparative Example 7 is a case where the resins (A-2) to (A-6) are not used, and tensile elongation is difficult to occur with only the crystalline polyolefin.

  The cross-linked thermoplastic flame retardant resin composition of the present invention is a cross-linked thermoplastic resin composition having excellent acid resistance, high flame retardancy, and high rated temperature. Processing of extrusion moldability, injection moldability, and blow moldability It can be suitably used as a coating material for non-halo electric wires.

Claims (4)

(A) A thermoplastic resin composition comprising 5 to 95% by mass of the following (A-1) and 95 to 5% by mass of at least one resin selected from the following (A-2) to (A-6). 100 parts by mass,
(B) A crosslinked thermoplastic flame retardant resin obtained by melt-kneading 10 to 300 parts by mass of aluminum hydroxide and (C) 0.001 to 2 parts by mass of an organic peroxide having a 1 minute half-life temperature of 165 ° C. or less. Composition.
(A-1) Crystalline polyolefin having a peak top melting point on the highest temperature side of the DSC melting curve of 120 to 150 ° C. (A-2) Thermoplastic resin having a hydrophilic functional group (A-3) Ethylene and α- Olefin copolymer (A-4) At least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound. Hydrogenated block copolymer (A-5) obtained by hydrogenation of a block copolymer comprising: a hydrogenated copolymer (A-) mainly comprising a random structure of an aromatic vinyl compound and a conjugated diene compound 6) Non-halogen non-crosslinked rubber The crosslinked thermoplastic flame retardant resin composition according to claim 1, which satisfies the following physical properties (i) to (v) measured according to JIS K 6723.
(I) Maximum tensile stress is 8 MPa or more (ii) Maximum tensile elongation is 200% or more (iii) Maximum tensile stress residual ratio after heat treatment is 80% or more (iv) Maximum tensile elongation residual ratio after heat treatment is 80% (V) Heat deformation rate is 40% or less   (A) 10 to 300 parts by mass of (B) and 0.001 to 2 parts by mass of (C) are blended with 100 parts by mass of the thermoplastic resin composition, and melt-kneaded at 165 ° C. or less. Item 3. A method for producing a crosslinked thermoplastic flame retardant resin composition according to Item 1 or 2.   A molded article comprising the crosslinked thermoplastic flame retardant resin composition according to claim 1.