JP4565828B2 - Flame retardant composition - Google Patents

Description

  The present invention relates to a non-halogen flame retardant composition using a hydrogenated block copolymer. More specifically, the present invention relates to a flame retardant composition comprising a hydrogenated block copolymer having a vinyl aromatic compound content of more than 40% by weight and less than 95% by weight, a modified elastomer and an inorganic filler as main components. About. And since the flame retardant composition of the present invention is excellent in flexibility, tensile strength, etc. and excellent in whitening resistance with scratches, each use in which a soft vinyl chloride resin is used, including a coating material for electric wires, etc. Can be suitably used.

As a covering material for electric wires of home appliance parts, automobile parts, etc., a vinyl chloride resin having excellent flame retardancy is generally used. Soft vinyl chloride resin is flexible and has excellent mechanical properties such as tensile strength and scratch resistance and whitening resistance. However, since a large amount of chlorine is contained in the molecule, there is a concern about the burden on the environment, and an alternative material is demanded.
In recent years, development of non-vinyl chloride resin-based flame retardant materials centered on olefin resins has been promoted, and flame retardant resin compositions in which hydrated metal oxides are blended with olefin resins such as polyethylene (for example, patent documents) 1) has been developed. In addition, a composition in which an inorganic flame retardant is blended with a thermoplastic elastomer and polyolefin (see, for example, Patent Document 2), a flame retardant in which a metal hydrate is blended with an olefin elastomer, modified polystyrene, styrene elastomer, or propylene resin. Resin compositions (see, for example, Patent Document 3) have been developed.

Japanese Patent Laid-Open No. 05-301996 Japanese Patent Publication No. 07-110912 JP 2002-138175 A

An object of the present invention is to provide a flame retardant composition having excellent flame retardancy, flexibility and mechanical properties comparable to a vinyl chloride resin, and whitening resistance with scratch resistance.
The non-vinyl chloride resin-based flame retardant material centered on the olefin resin described above contains a large amount of metal hydrate. Therefore, the composition is poor in flexibility and mechanical properties such as tensile strength, whitening resistance with scratches, and the like are reduced.

Under such circumstances, the present inventors have intensively studied to solve the above problems. As a result, the inventors of the present invention have a composition based on a hydrogenated block copolymer having a vinyl aromatic compound content of more than 40% by weight and less than 95% by weight, a modified elastomer, and an inorganic filler. The present inventors have found that the above problems can be solved, and have completed the present invention based on this finding.
That is, the present invention
1. (A) At least one hydrogenation obtained by hydrogenating a polymer block (A) composed of at least two vinyl aromatic compounds and a non-hydrogenated random copolymer block composed of a conjugated diene compound and a vinyl aromatic compound 20 to 60% by weight of a hydrogenated block copolymer comprising the copolymer block (B) and having the following characteristics (1) to (5):
(1) The content of the vinyl aromatic compound is more than 40% by weight and less than 95% by weight with respect to the weight of the hydrogenated block copolymer,
(2) The content of the polymer block (A) is 5 to 60% by weight based on the weight of the hydrogenated block copolymer,
(3) The weight average molecular weight is 30,000 to 1,000,000,
(4) The hydrogenation rate of the double bond based on the conjugated diene compound is 75% or more,
(5) In the differential scanning calorimetry (DSC) chart obtained for the hydrogenated block copolymer, crystallization due to the at least one hydrogenated copolymer block (B) in the range of -20 to 80 ° C. There are virtually no peaks,
(B) 1-20% by weight of a styrenic modified elastomer in which an atomic group having an acid anhydride group is bonded by graft modification or terminal modification,
(C) 30 to 62% by weight of an inorganic filler comprising a metal hydroxide,
A flame retardant composition comprising:

  However, the “Differential Scanning Calorimetry (DSC) chart” uses a DSC apparatus to increase the temperature from room temperature to 150 ° C. at a temperature increase rate of 30 ° C./min, and then to −100 ° C. at a temperature decrease rate of 10 ° C./min. Is a chart in which the crystallization curve was measured by lowering the temperature to “No substantial crystallization peak due to the hydrogenated copolymer block (B) in the range of −20 to 80 ° C.” In the range, a peak due to crystallization of the hydrogenated copolymer block (B) does not appear, or a peak due to crystallization is observed, but the crystallization peak heat quantity due to the crystallization is less than 3 J / g. It means that there is.

2. (D) 1 to 20 parts by weight of an olefin resin is further blended with respect to 100 parts by weight of the total amount of (a), (b) and (c) . The flame retardant composition according to 1.

Although the flame retardant composition of the present invention is flame retardant, it has excellent mechanical properties such as flexibility, tensile strength, and whitening resistance with scratches. It can be suitably used for each application in which a soft vinyl chloride resin is used.
Hereinafter, the present invention will be described in detail.
The component (a) as the main component of the present invention is a hydrogenated non-hydrogenated copolymer containing a conjugated diene compound and a vinyl aromatic compound (hereinafter often referred to as “base non-hydrogenated copolymer”). This is a hydrogenated block copolymer.
The content of the vinyl aromatic compound in the hydrogenated block copolymer used in the present invention is more than 40% by weight and less than 95% by weight with respect to the hydrogenated copolymer. Since the content of the vinyl aromatic compound is in the above range, it is excellent in flexibility, mechanical properties, and scratch resistance. From the viewpoint of flexibility, the content of the vinyl aromatic compound is preferably more than 40% by weight and 80% by weight or less, more preferably more than 45% by weight and 70% by weight or less, particularly preferably more than 45% by weight and more than 60% by weight. % By weight or less. In particular, when the hydrogenated block copolymer does not have the hydrogenated polymer block (C), the content of the vinyl aromatic compound is preferably more than 40% by weight and 90% by weight or less, more preferably 45% by weight. More than 85% by weight, more preferably more than 50% by weight and 80% by weight or less.

Since the content of the vinyl aromatic compound relative to the hydrogenated copolymer is substantially equal to the content of the vinyl aromatic compound relative to the base non-hydrogenated copolymer, the content of the vinyl aromatic compound relative to the hydrogenated copolymer is Obtained as the content of the base non-hydrogenated copolymer. The content of the vinyl aromatic compound relative to the hydrogenated copolymer is measured using an ultraviolet spectrophotometer using the base non-hydrogenated copolymer as a specimen. In addition, when measuring the content of a vinyl aromatic compound using a hydrogenated copolymer as a specimen, it can be measured using a nuclear magnetic resonance apparatus.
The hydrogenated block copolymer used in the present invention is a hydrogenated polymer block (A) obtained by hydrogenating a polymer block (A) composed of a vinyl aromatic compound and a non-hydrogenated polymer block composed of a conjugated diene compound ( At least one polymer block selected from the group consisting of C) and at least one hydrogenated copolymer obtained by hydrogenating a non-hydrogenated random copolymer block composed of a conjugated diene compound and a vinyl aromatic compound. It is recommended to include the polymer block (B) (however, the vinyl bond amount of the non-hydrogenated polymer block made of a conjugated diene compound is less than 30%).

The polymer block (A) and the hydrogenated polymer block (C) serve as physical cross-linking points and are therefore referred to as “constrained phase”. On the other hand, the hydrogenated copolymer block (B) is referred to as “unconstrained phase”. It is recommended that the hydrogenated block copolymer used in the present invention has two or more polymer blocks that are a constrained phase. Moreover, when it does not have a hydrogenated polymer block (C), it is preferable from the point of mechanical characteristics that a hydrogenated block copolymer has at least two polymer blocks (A). In the case where the hydrogenated block copolymer used in the present invention has two or more polymer blocks that are a constrained phase, a composition having a high tensile elongation at break and a high tensile strength can be obtained.
In the case where the hydrogenated block copolymer used in the present invention does not have the hydrogenated polymer block (C), in the differential scanning calorimetry (DSC) chart obtained for the hydrogenated copolymer, -20 to 80 It is recommended that there is substantially no crystallization peak due to the hydrogenated copolymer block (B) in the range of ° C. Here, “the crystallization peak due to the hydrogenated copolymer block (B) is not substantially present in the range of −20 to 80 ° C.” means that the hydrogenated copolymer block (B) in this temperature range. The peak due to crystallization does not appear or the peak due to crystallization is observed, but the crystallization peak heat due to the crystallization is less than 3 J / g, preferably less than 2 J / g, more preferably 1 J / G, particularly preferably means no crystallization peak heat.

A hydrogenated copolymer having substantially no crystallization peak due to the hydrogenated polymer block (B) in the range of −20 to 80 ° C. in the differential scanning calorimetry (DSC) chart has good flexibility. . A hydrogenated copolymer having substantially no crystallization peak due to the hydrogenated copolymer block (B) in the range of −20 to 80 ° C. as described above is a vinyl bond amount adjusting agent or A non-hydrogenated copolymer obtained by conducting a polymerization reaction under the conditions described later using a regulator as described later for adjusting the random copolymerizability between the conjugated diene and the vinyl aromatic compound Obtained by hydrogenation.
In the case of having a hydrogenated polymer block (C), in the differential scanning calorimetry (DSC) chart, regarding the crystallization peak due to the hydrogenated polymer block (C), the crystallization peak temperature is 30 ° C. or higher, preferably It preferably has a crystallization peak in the temperature range of 45 to 100 ° C, more preferably 50 to 90 ° C. The crystallization peak heat quantity is preferably 3 J / g or more, preferably 6 J / g or more, and more preferably 10 J / g or more.
The crystallization peak temperature and the crystallization peak calorie can be measured using a differential scanning calorimeter.

In the hydrogenated block copolymer used in the present invention, the content of the polymer block (A) is 0 to 60% by weight based on the hydrogenated copolymer. By setting the content of the polymer block (A) in the above range, a composition having excellent flexibility can be obtained. The content of the polymer block (A) is preferably 5 to 60% by weight, more preferably 8 to 50% by weight, further preferably 10 to 40% by weight, and particularly preferably 12 to 35% by weight.
In the hydrogenated block copolymer used in the present invention, the content of the polymer block (A) with respect to the hydrogenated copolymer is substantially equal to the content of the polymer block (A) with respect to the base non-hydrogenated copolymer. Therefore, the content rate of the polymer block (A) with respect to the hydrogenated copolymer is determined as the content rate of the polymer block (A) with respect to the base non-hydrogenated copolymer. Specifically, a method of oxidatively decomposing a base non-hydrogenated copolymer with tertiary butyl hydroperoxide using osmium tetroxide as a catalyst (described in IMKOLTHOFF, et al., J. Polym. Sci. 1,429 (1946)). The weight of the vinyl aromatic polymer block component determined by the method, hereinafter often referred to as the “osmium tetroxide decomposition method” (however, the vinyl aromatic polymer component having an average degree of polymerization of about 30 or less is excluded) Is obtained from the following equation.
Content (% by weight) of vinyl aromatic polymer block (A) = (weight of vinyl aromatic polymer block (A) in base non-hydrogenated copolymer / weight of base non-hydrogenated copolymer) × 100.

The weight average molecular weight of the hydrogenated block copolymer used in the present invention is preferably 30,000 to 1,000,000. When the weight average molecular weight is in the above range, the balance between mechanical strength and moldability is excellent. From the point of balance between mechanical strength and moldability, the weight average molecular weight of the hydrogenated block copolymer used in the present invention is preferably 50,000 to 800,000, more preferably 100,000 to 500,000, particularly preferably. Is 150,000 to 400,000.
In the hydrogenated block copolymer used in the present invention, the molecular weight distribution (Mw / Mn) (ratio of weight average molecular weight (Mw) to number average molecular weight (Mn)) is preferably 10 or less, more preferably 1.01. 8, particularly preferably 1.1-5. When emphasizing molding processability, it is preferably 1.3 to 5, more preferably 1.5 to 5, even more preferably 1.6 to 4.5, and particularly preferably 1.8 to 4.

Since the weight average molecular weight of the hydrogenated block copolymer is almost equal to the weight average molecular weight of the base non-hydrogenated copolymer, the weight average molecular weight of the hydrogenated block copolymer is calculated as the weight average molecular weight of the base non-hydrogenated copolymer. Ask. The weight average molecular weight of the base non-hydrogenated copolymer is determined by gel permeation chromatography (GPC) using a calibration curve obtained for a commercially available standard monodisperse polystyrene having a known molecular weight. The number average molecular weight of the hydrogenated copolymer is determined in the same manner. The molecular weight distribution is obtained by calculation as a ratio of the weight average molecular weight to the number average molecular weight. In addition, when measuring a hydrogenated block copolymer as a test substance, it can obtain | require similarly.
The hydrogenation rate of double bonds based on the conjugated diene compound of the hydrogenated block copolymer used in the present invention is preferably 75 to 100%. The hydrogenation rate is preferably 80 to 100%, more preferably 85 to 100%, and particularly preferably 90 to 100% from the viewpoint of mechanical strength.
The hydrogenation rate of the double bond of the vinyl aromatic compound in the hydrogenated block copolymer is not particularly limited, but the hydrogenation rate is preferably 50% or less, more preferably 30% or less, and particularly preferably 20 % Or less.
The hydrogenation rate in the hydrogenated block copolymer can be measured using a nuclear magnetic resonance apparatus.

The hydrogenated copolymer block (B) in the hydrogenated block copolymer is obtained by hydrogenating a non-hydrogenated random copolymer block composed of a conjugated diene compound and a vinyl aromatic. The microstructure (ratio of cis, trans, vinyl) of the conjugated diene compound in the non-hydrogenated random copolymer can be arbitrarily changed by using a polar compound described later. In the present invention, the vinyl bond content of the conjugated diene monomer unit in the non-hydrogenated random copolymer block comprising a conjugated diene compound and a vinyl aromatic compound is preferably less than 40% {hereinafter, 1, The total amount of 2-vinyl bond and 3,4-vinyl bond (however, when 1,3-butadiene is used as the conjugated diene, 1,2-vinyl bond amount) is simply referred to as vinyl bond amount. }. The hydrogenated polymer block (C) in the hydrogenated block copolymer is obtained by hydrogenating a non-hydrogenated polymer block composed of a conjugated diene compound and having a vinyl bond content of less than 30%. The vinyl bond amount of the non-hydrogenated polymer block is preferably 8 to 25%, more preferably 10 to 25%, and particularly preferably 12 from the viewpoint of the handleability (anti-blocking) of the hydrogenated block copolymer itself. ~ 20%.
The vinyl bond amount is measured using an infrared spectrophotometer using the base non-hydrogenated copolymer as a specimen. In addition, when measuring a hydrogenated block copolymer as a test substance, it can measure using a nuclear magnetic resonance apparatus.

The structure of the hydrogenated block copolymer used in the present invention is not particularly limited, and any structure can be used. One embodiment of the hydrogenated block copolymer includes a hydrogenated copolymer including at least two polymer blocks (A) and at least one hydrogenated copolymer block (B). Examples of such a hydrogenated block copolymer include those having a structure represented by the following formula.
(AB) n + 1, A- (BA) n,
B- (AB) n + 1,
[(AB) n] m-X, [(BA) n-B] m-X,
[(AB) n-A] m-X, [(BA) n + 1] m-X
Further, as another embodiment of the hydrogenated block copolymer used in the present invention, at least one hydrogenated polymer block (C), at least one hydrogenated copolymer block (B), and in some cases Examples of the hydrogenated copolymer include at least one polymer block (A). Examples of such a hydrogenated block copolymer include those having a structure represented by the following formula. It is done.
(C-B) n, C- (B-C) n, B- (C-B) n,
[(C-B) n] m-X, [(BC) n-B] m-X,
[(C-B) n-C] m-X,
C- (BA) n, C- (AB) n,
C- (ABA) n, C- (BABB) n,
AC- (BA) n, AC- (AB) n,
A-C- (B-A) n-B, [(A-B-C) n] m-X,
[A- (BC) n] m-X, [(AB) n-C] m-X,
[(ABA) n-C] m-X,
[(B-A-B) n-C] m-X, [(C-B-A) n] m-X,
[C- (BA) n] m-X,
[C- (ABA) n] m-X,
[C- (BAB) n] m-X

In the above formula, each A independently represents a polymer block composed of a vinyl aromatic compound. Each B represents a hydrogenated copolymer block obtained by hydrogenating a non-hydrogenated random copolymer composed of a conjugated diene compound and a vinyl aromatic compound. Each C independently represents a hydrogenated polymer block obtained by hydrogenating a non-hydrogenated polymer block comprising a conjugated diene compound and having a vinyl bond content of less than 30%. The boundary of each block does not necessarily have to be clearly distinguished. The vinyl aromatic compound in the hydrogenated copolymer block B obtained by hydrogenating the non-hydrogenated random copolymer may be distributed uniformly or in a tapered shape.
Further, the hydrogenated copolymer block B may have a plurality of portions where the vinyl aromatic compound is uniformly distributed and / or portions where the vinyl aromatic compound is distributed in a tapered shape. In the hydrogenated copolymer block B, a plurality of segments having different vinyl aromatic compound contents may be present. Each n is independently an integer of 1 or more, preferably an integer of 1 to 5. Each m is independently an integer of 2 or more, preferably an integer of 2 to 11. Each X independently represents a residue of a coupling agent or a residue of a polyfunctional initiator. As the coupling agent, a bifunctional or higher functional coupling agent described later can be used. As the polyfunctional initiator, a reaction product of diisopropenylbenzene and sec-butyllithium, a reaction product of divinylbenzene, sec-butyllithium and a small amount of 1,3-butadiene, or the like can be used.

The hydrogenated block copolymer used in the present invention may be any mixture having the structure represented by the above formula. The hydrogenated copolymer includes a hydrogenated copolymer having a structure represented by the above formula, a polymer composed of a vinyl aromatic compound, a copolymer having an AB structure, and B-A-B. It may be a mixture with at least one polymer selected from the group consisting of copolymers having a structure.
In the present invention, the conjugated diene used is a diolefin having a pair of conjugated double bonds. Examples of conjugated dienes include 1,3-butadiene, 2-methyl-1,3-butadiene (ie, isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1, Examples include 3-pentadiene and 1,3-hexadiene. Of these, 1,3-butadiene and isoprene are particularly preferred. These may be used alone or in combination of two or more.
Examples of vinyl aromatic compounds include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl- p-aminoethylstyrene may be mentioned. These may be used alone or in combination of two or more.

  As described above, the hydrogenated block copolymer used in the present invention is obtained by hydrogenating a non-hydrogenated copolymer containing a conjugated diene compound and a vinyl aromatic compound. There is no limitation in particular about the manufacturing method of this non-hydrogenated copolymer, A well-known method can be used. For example, it can be produced by anionic living polymerization using a polymerization initiator such as an organic alkali metal compound in a hydrocarbon solvent. Examples of hydrocarbon solvents include aliphatic hydrocarbons such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, and n-octane; alicyclic carbonization such as cyclohexane, cycloheptane, and methylcycloheptane Hydrogen; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene.

Examples of the polymerization initiator include aliphatic hydrocarbon alkali metal compounds, aromatic hydrocarbon alkali metal compounds, and organic aminoalkali metal compounds having anionic polymerization activity with respect to conjugated dienes and vinyl aromatic compounds. Examples of the alkali metal include lithium, sodium, and potassium. Examples of suitable organic alkali metal compounds are aliphatic and aromatic hydrocarbon lithium compounds having 1 to 20 carbon atoms, and compounds containing at least one lithium in one molecule (monolithium compounds, dilithium compounds, trilithium compounds, Lithium compounds, tetralithium compounds, etc.).
Specifically, n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, n-pentyllithium, n-hexyllithium, benzyllithium, phenyllithium, tolyllithium, diisopropenylbenzene and sec- A reaction product of butyllithium, a reaction product of divinylbenzene, sec-butyllithium and a small amount of 1,3-butadiene can be used. Furthermore, organic alkali metal compounds disclosed in US Pat. No. 5,708,092, British Patent 2,241,239, US Pat. No. 5,527,753, etc. are also used. be able to.

In the present invention, when an organic alkali metal compound is used as a polymerization initiator to copolymerize a conjugated diene compound and a vinyl aromatic compound, a vinyl bond (1, 2 vinyl bond or 3, In order to adjust the amount of (4-vinyl bond) and the random copolymerizability between the conjugated diene and the vinyl aromatic compound, a tertiary amine compound or an ether compound can be added as a regulator.
In the present invention, the method of copolymerizing a conjugated diene compound and a vinyl aromatic compound using an organic alkali metal compound as a polymerization initiator may be batch polymerization, continuous polymerization, or a combination thereof. . In particular, continuous polymerization is recommended for adjusting the molecular weight distribution to a preferable range in terms of moldability. The polymerization temperature is usually 0 to 180 ° C, preferably 30 to 150 ° C. The time required for the polymerization varies depending on other conditions, but is usually within 48 hours, preferably 0.1 to 10 hours. The polymerization atmosphere is preferably an inert gas atmosphere such as nitrogen gas. The polymerization pressure is not particularly limited as long as it is within a range sufficient to maintain the monomer and solvent in a liquid phase within the above polymerization temperature range. Furthermore, it is necessary to pay attention so that impurities (water, oxygen, carbon dioxide, etc.) that inactivate the catalyst and the living polymer do not enter the polymerization system.

  In the present invention, a coupling reaction can be performed using a bifunctional or higher functional coupling agent at the time when the polymerization is completed. There are no particular limitations on the bifunctional or higher functional coupling agent, and known coupling agents can be used. Examples of the bifunctional coupling agent include dihalogen compounds such as dimethyldichlorosilane and dimethyldibromosilane; acid esters such as methyl benzoate, ethyl benzoate, phenyl benzoate, and phthalates. Examples of trifunctional or higher polyfunctional coupling agents include trihydric or higher polyalcohols; polyvalent epoxy compounds such as epoxidized soybean oil and diglycidyl bisphenol A; formula R4-n SiXn (where each R is independent) And a halogenated silicon compound such as methylsilyltrichloride, t, wherein each X independently represents a halogen atom, and n represents 3 or 4. -Butylsilyl trichloride, silicon tetrachloride, and bromides thereof; formula R4-n SnXn (where each R independently represents a hydrocarbon group having 1 to 20 carbon atoms, and each X is independently A halogen atom, n represents 3 or 4, and a polyvalent halo such as methyltin trichloride, t-butyltin trichloride, tin tetrachloride, etc. Emission compounds. Moreover, dimethyl carbonate, diethyl carbonate, etc. can also be used as a polyfunctional coupling agent.

By hydrogenating the non-hydrogenated copolymer produced by the above method, the hydrogenated copolymer of the present invention is obtained. There is no limitation in particular in a hydrogenation catalyst, A well-known hydrogenation catalyst can be used. Examples of the hydrogenation catalyst include the following.
(1) A supported heterogeneous hydrogenation catalyst in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth,
(2) a so-called Ziegler-type hydrogenation catalyst using an organic acid salt such as Ni, Co, Fe, Cr or a transition metal salt such as acetylacetone salt together with a reducing agent such as organoaluminum, and (3) Ti, Ru, Rh, Homogeneous hydrogenation catalysts such as so-called organometallic complexes such as organometallic compounds such as Zr.
Specific hydrogenation catalysts include Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841 (corresponding to US Pat. No. 4,501,857), Japanese Patent Publication No. 1- Hydrogenation catalysts described in Japanese Patent No. 37970 (corresponding to US Pat. No. 4,673,714), Japanese Patent Publication No. 1-53851 and Japanese Patent Publication No. 2-9041 can be used. Examples of preferred hydrogenation catalysts include titanocene compounds and mixtures of titanocene compounds and reducible organometallic compounds.

As the titanocene compound, compounds described in JP-A-8-109219 can be used. Specifically, it has at least one ligand having a (substituted) cyclopentadienyl skeleton, indenyl skeleton or fluorenyl skeleton such as biscyclopentadienyl titanium dichloride and monopentamethylcyclopentadienyl titanium trichloride. Compounds. Examples of the reducing organometallic compound include organoalkali metal compounds such as organolithium, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds.
The hydrogenation reaction for producing the hydrogenated block copolymer used in the present invention is usually carried out in a temperature range of 0 to 200 ° C, preferably 30 to 150 ° C. The pressure of hydrogen used for the hydrogenation reaction is usually 0.1 to 15 MPa, preferably 0.2 to 10 MPa, and more preferably 0.3 to 5 MPa. The hydrogenation reaction time is usually 3 minutes to 10 hours, preferably 10 minutes to 5 hours. The hydrogenation reaction can be used in any of batch processes, continuous processes, and combinations thereof.

A hydrogenated block copolymer solution is obtained by the hydrogenation reaction. If necessary, catalyst residues are removed from the hydrogenated copolymer solution, and the hydrogenated copolymer is separated from the solution. An example of a method for separating the solvent is a method in which a polar solvent that is a poor solvent for the hydrogenated copolymer such as acetone or alcohol is added to the reaction solution after hydrogenation to precipitate and recover the polymer; Examples thereof include a method in which the solvent is removed by steam stripping and recovered by stirring in hot water under stirring; and a method in which the solvent is distilled off by directly heating the polymer solution.
In addition, stabilizers, such as various phenol type stabilizers, phosphorus type stabilizers, sulfur type stabilizers, and amine type stabilizers, can be added to the hydrogenated block copolymer used in the present invention.

Component (b) of the present invention is a modified elastomer to which an atomic group having a functional group is bonded.
Elastomers used as bases prior to bonding of functional group-containing atomic groups include conjugated diene copolymers and hydrogenated products thereof, styrene-conjugated diene random copolymers and hydrogenated products thereof, and styrene-conjugated diene block copolymers. Styrene elastomers such as coalesced and hydrogenated products, ethylene-propylene copolymers, ethylene-propylene-butylene copolymers, ethylene-butylene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers, etc. An olefin type elastomer is mentioned. Among these, a styrene elastomer selected from a hydrogenated product of a styrene-butadiene block copolymer, a hydrogenated product of a styrene-isoprene block copolymer, and a hydrogenated product of a styrene-butadiene / isoprene block copolymer is particularly preferable.
The method for modifying the elastomer and the type of the modifier are not particularly limited.
One example thereof is an elastomer graft-modified with a functional group-containing compound such as an α, β-unsaturated carboxylic acid or a derivative thereof, for example, an anhydride, esterified product, amidated product or imidized product thereof. Specific examples of α, β-unsaturated carboxylic acids or derivatives thereof include maleic anhydride, maleic imide, acrylic acid or ester thereof, methacrylic acid or ester thereof, endo-cis-bicyclo [2,2,1]. -5-heptene-2,3-dicarboxylic acid or its anhydride.

The amount of α, β-unsaturated carboxylic acid or its derivative added is usually 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight per 100 parts by weight of the elastomer.
The reaction temperature in the case of graft modification is preferably 100 to 300 ° C, more preferably 120 to 280 ° C. For details of the graft modification method, reference can be made to, for example, JP-A No. 62-79211.
Another example is a terminal-modified elastomer. For example, a modified elastomer can be obtained by reacting a living group terminal of a base copolymer obtained using an organolithium compound as a polymerization catalyst with a functional group-containing compound (hereinafter also referred to as a modifier).

Examples of functional group-containing modifier groups include hydroxyl groups, carbonyl groups, thiocarbonyl groups, acid halide groups, acid anhydride groups, carboxyl groups, thiocarboxylate groups, aldehyde groups, thioaldehyde groups, carboxylate ester groups, amides. Group, sulfonic acid group, sulfonic acid ester group, phosphoric acid group, phosphoric acid ester group, amino group, imino group, cyano group, pyridyl group, quinoline group, epoxy group, thioepoxy group, sulfide group, isocyanate group, isothiocyanate group And those having at least one functional group selected from the group consisting of silicon halide groups, silanol groups, alkoxysilane groups, tin halide groups, alkoxytin groups, phenyltin groups, and the like. Of the above functional groups, a carbonyl group, a carboxyl group, an acid anhydride group, a hydroxyl group, an amino group, an imino group, an isocyanate group, an epoxy group, a silanol group, and an alkoxysilane group are preferable.
As specific examples of the denaturing agent, for example, a terminal denaturing treatment agent described in JP-B-4-39495 (corresponding to US Pat. No. 5,115,035) or JP03 / 02222 (international publication) is used. Can do. Specifically, tetraglycidyl metaxylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, ε-caprolactone, 4-methoxybenzophenone, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxybutyltrimethoxy Examples include silane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N-methylpyrrolidone and the like.

Component (c) of the present invention is an inorganic filler. Examples of the inorganic filler include metal hydroxides, metal carbonates, metal oxides, silica-based inorganic fillers, and the like.
Of these, metal hydroxides are particularly useful in terms of flame retardancy. Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, hydrated aluminum silicate, hydrated magnesium silicate, basic magnesium carbonate, hydrotalcite, calcium hydroxide, barium hydroxide, tin oxide And hydrates of inorganic metal compounds such as borax, among which magnesium hydroxide is preferred. Further, magnesium hydroxide whose surface is treated with a silane coupling agent or a fatty acid may be used. Magnesium hydroxide surface-treated with a coupling agent such as aminosilane or methacryloxysilane in order to enhance dispersibility in the polymer is commercially available. A specific example is Kisuma 5L (manufactured by Kyowa Chemical Industry Co., Ltd.).

Examples of the metal carbonate include calcium carbonate and magnesium carbonate.
Further, the metal oxide is a solid particle whose main component is a chemical unit Mx Oy (M is a metal atom, x and y are each independently an integer of 1 to 6), such as alumina, titanium oxide, Examples include magnesium oxide and zinc oxide.
Further, silica-based inorganic filler is a solid particle composed mainly of structural units of the formula SiO _2, for example, silica, clay, talc, kaolin, mica, wollastonite, montmorillonite, zeolite, inorganic, such as glass fibers Examples include fibrous materials.
In the flame retardant composition according to the present invention, the blending ratio of each component is 20 to 60% by weight of the component (a) hydrogenated block copolymer, 1 to 20% by weight of the component (b) modified elastomer, c) The inorganic filler is 30 to 80% by weight.
When the component (a) is less than 20% by weight, the composition has poor mechanical properties such as flexibility and tensile strength, and when it exceeds 60% by weight, the composition has poor flame retardancy.
In addition, component (b) significantly improves scratch resistance and whitening properties. When the blending amount is less than 1% by weight, the composition is inferior in whitening resistance with scratches, and when it exceeds 20% by weight, the composition is inferior in workability.
When the amount of component (c) is less than 30% by weight, the composition is inferior in flame retardancy, and when it exceeds 80% by weight, the composition is inferior in mechanical properties such as flexibility and tensile strength.

In addition to the flame retardant composition of the present invention, the following component (d) and component (e) can be blended.
Component (d) is an olefin resin. Examples of olefin resins include polypropylene resins such as polypropylene and propylene-ethylene copolymers (random PP, block PP), polyethylene, ethylene containing 50% by weight or more of ethylene and other monomers copolymerizable therewith. Copolymers, for example, ethylene-vinyl acetate copolymers and hydrolysates thereof, and polyethylene resins such as ethylene-acrylic acid ionomers. Among these, polypropylene resins such as homo PP and random PP are preferable.
Component (d) is blended for the purpose of improving the heat distortion resistance of the flame retardant composition. The addition amount is 20 parts by weight or less (with respect to (a) + (b) + (c) = 100 parts by weight), and it is recommended to add in consideration of the target flexibility and heat distortion resistance. . When the amount of the olefin resin exceeds 20 parts by weight, the composition with inferior flexibility is inferior.

In order to improve the processability of the flame retardant composition, a rubber softener (referred to as component (e)) may be blended. As the rubber softener, mineral oil or a liquid or low molecular weight synthetic softener is suitable. Among them, naphthenic and / or paraffinic process oils or extender oils that are generally used for softening rubber, increasing volume, and improving processability are preferable. The mineral oil rubber softener is a mixture of aromatic rings, naphthene rings and paraffin chains. Here, the paraffin chain having 50% or more of carbon atoms in the paraffin chain is called paraffinic, the naphthene ring having 30 to 45% carbon is naphthenic, and the aromatic carbon number is 30%. What exceeds is called aromatic. A synthetic softener may be used in the composition of the present invention, and polybutene, low molecular weight polybutadiene, liquid paraffin, and the like can be used. However, the mineral oil rubber softeners described above are preferred.
The amount of component (e) added is 50 parts by weight or less (based on (a) + (b) + (c) = 100 parts by weight). If it exceeds 50 parts by weight, bleeding out is likely to occur, and the surface of the composition may be sticky.

The flame retardant composition of the present invention may contain other rubbery polymers, thermoplastic resins, additives and the like, if desired.
Examples of rubber-like polymers include styrene-butadiene block copolymers and hydrogenated products thereof, styrene-based elastomers such as styrene-isoprene block copolymers and hydrogenated products thereof (provided that component (a) of the present invention and Olefin-based elastomers such as 1,2-polybutadiene, ethylene-butene rubber, ethylene-octene rubber, ethylene-propylene-diene rubber (EPDM), and butyl rubber.
Examples of thermoplastic resins include block copolymer resins of conjugated dienes and vinyl aromatics and hydrogenated products thereof (but different from the component (a) of the present invention), styrene such as polystyrene and rubber-modified styrene resins. Resin, polyamide resin, polyester resin, polycarbonate resin and the like.

  The additive is not particularly limited as long as it is generally blended with a rubbery polymer or the like. Examples of additives include those described in “Rubber / Plastic Compounding Chemicals” (edited by Rubber Digest Co., Ltd.). Specific examples include pigments such as carbon black and iron oxide; lubricants such as stearic acid, behenic acid, zinc stearate, calcium stearate, magnesium stearate, and ethylene bisstearamide; release agents; organic polysiloxanes and hindered phenols -Based antioxidants, antioxidants such as phosphorus-based heat stabilizers; hindered amine-based light stabilizers; benzotriazole-based UV absorbers; flame retardants; antistatic agents, organic fibers, glass fibers, carbon fibers, metal whiskers, etc. Agents; coloring agents and the like. These additives may be used in combination of two or more.

The method for producing the flame retardant composition of the present invention is not particularly limited, and a known method can be used. For example, a melt kneading method using a general blender such as a Banbury mixer, a single screw extruder, a twin screw extruder, a kneader, or a multi-screw extruder can be used.
When the flame retardant composition of the present invention is used as a molded product, the molding method is extrusion molding, injection molding, hollow molding, pressure molding, vacuum molding, foam molding, multilayer extrusion molding, multilayer injection molding, slash Molding and calendering can be used.
Moreover, the flame retardant composition of the present invention can be used in various applications where flame retardancy is required. For example, it can be suitably used for coating materials such as household electrical appliance parts and automobile parts, coating materials such as power cables, communication cables, and power transmission cables, and building materials.

Hereinafter, the present invention will be specifically described with reference examples, examples and comparative examples, but the present invention is not limited to these examples.
I. Preparation of hydrogenated block copolymer The hydrogenated block copolymer used was obtained by hydrogenating a non-hydrogenated copolymer. This non-hydrogenated copolymer is often referred to as a “base non-hydrogenated copolymer”.
The characteristics of the hydrogenated copolymer were measured by the following method.
I-1) Styrene content The content of styrene with respect to the hydrogenated block copolymer was measured using an ultraviolet spectrophotometer (UV-2450; manufactured by Shimadzu Corporation) using the base non-hydrogenated copolymer as a specimen. The content of styrene with respect to the hydrogenated copolymer was determined as the content of styrene with respect to the base non-hydrogenated copolymer.
In addition, when using a hydrogenated copolymer as a test substance, it measured using the nuclear magnetic resonance apparatus (Germany BRUKER company make, DPX-400).
I-2) Styrene polymer block content The styrene polymer block content of the non-hydrogenated copolymer is described in IMKolthoff, et al., J. MoI. Polym. Sci. 1, 429 (1946) was measured by the osmium tetroxide decomposition method. For the decomposition of the non-hydrogenated block copolymer, a 0.1 g / 125 ml tertiary butanol solution of osmic acid was used.

I-3) Content of hydrogenated copolymer block (B) obtained by hydrogenating non-hydrogenated random copolymer block The content of hydrogenated copolymer block (B) is determined according to non-hydrogenated random copolymer block. It is determined from the amount of butadiene and styrene added when producing the polymer block. The content of the hydrogenated copolymer block (B) with respect to the hydrogenated copolymer is determined as the content of the non-hydrogenated random copolymer block with respect to the base non-hydrogenated copolymer.
I-4) Vinyl Bond Amount The vinyl bond amount of the polymer block in the base non-hydrogenated copolymer was measured using an infrared spectrophotometer (FT / IR-230; manufactured by JASCO Corporation). The vinyl bond amount of the conjugated diene polymer block which is a homopolymer block was calculated by the Morero method. The vinyl bond amount of the conjugated diene / styrene copolymer block, which is a copolymer block, was calculated by the Hampton method.

I-5) Weight average molecular weight and molecular weight distribution Since the weight average molecular weight of the hydrogenated block copolymer is almost equal to the weight average molecular weight of the base non-hydrogenated copolymer, the weight average molecular weight of the hydrogenated copolymer is The weight average molecular weight of the additive copolymer is determined. The weight average molecular weight of the base non-hydrogenated copolymer was measured by GPC (using an apparatus manufactured by Waters, USA). Tetrahydrofuran was used as a solvent, and the temperature was measured at 35 ° C. The weight average molecular weight was calculated | required from the GPC chromatogram using the calibration curve created using the commercially available standard monodisperse polystyrene type gel with known molecular weight.
The number average molecular weight was determined from the GPC chromatogram.
The molecular weight distribution is determined as a ratio of the obtained weight average molecular weight (Mw) to the obtained number average molecular weight (Mn).

I-6) Hydrogenation rate of double bond of conjugated diene compound The hydrogenation rate was measured using a nuclear magnetic resonance apparatus (DPX-400; manufactured by BRUKER, Germany).
I-7) Crystallization peak and crystallization peak calorie The crystallization peak and crystallization peak calorie of the hydrogenated block copolymer were measured using a DSC apparatus (DSC3200S; manufactured by Mac Science, Japan). The temperature was raised from room temperature to 150 ° C. at a rate of temperature rise of 30 ° C./min, and then the temperature was lowered to −100 ° C. at a rate of temperature drop of 10 ° C./min. Further, when there was a crystallization peak, the temperature at which the peak appeared was defined as the crystallization peak temperature, and the crystallization peak calorie was measured.

The hydrogenation catalyst used for the hydrogenation reaction was produced as follows.
Reference Example 1 Preparation of Hydrogenation Catalyst 2 liters of dried and purified cyclohexane was charged into a nitrogen-substituted reaction vessel, and 40 mmol of bis (η 5 -cyclopentadienyl) titanium di- (p-tolyl) and a molecular weight of about 1, 1, 150 g of 1,2-polybutadiene (approximately 85% of 1,2-vinyl bonds) was dissolved, and then a cyclohexane solution containing 60 mmol of n-butyllithium was added and reacted at room temperature for 5 minutes. A hydrogenation catalyst was obtained by adding and stirring 40 mmol of n-butanol.
Reference Example 2 Production of Hydrogenated Block Copolymer Copolymerization was carried out by the following method using a stirrer having an internal volume of 10 liters and a tank reactor with a jacket.
After 10 parts by weight of cyclohexane was charged into the reactor and adjusted to a temperature of 70 ° C., n-butyllithium was 0.072% by weight based on the weight of all monomers (the total amount of butadiene monomer and styrene monomer charged into the reactor), N, N, N ′, N′-tetramethylethylenediamine (hereinafter referred to as TMEDA) is added in an amount of 0.8 mol to 1 mol of n-butyllithium, and then a cyclohexane solution containing 10 parts by weight of styrene as a monomer A concentration of 22% by weight) was added over about 3 minutes, and the reaction was carried out for 30 minutes while adjusting the internal temperature of the reactor to about 70 ° C.

Next, a cyclohexane solution (monomer concentration of 22% by weight) containing 35 parts by weight of butadiene and 45 parts by weight of styrene was continuously fed to the reactor at a constant rate over 60 minutes. During this time, the reactor internal temperature was adjusted to about 70 ° C.
Thereafter, a cyclohexane solution containing 10 parts by weight of styrene as a monomer (monomer concentration: 22% by weight) was added over about 3 minutes, and the reaction was carried out for 30 minutes while adjusting the internal temperature of the reactor to about 70 ° C. Got. The resulting copolymer had a styrene content of 65% by weight, a styrene polymer block content of 20% by weight, and a vinyl content in the butadiene portion of 20%. The copolymer had a weight average molecular weight of 162,000 and a molecular weight distribution of 1.1.
Next, 100 weight ppm of the hydrogenation catalyst as titanium with respect to the weight of the copolymer was added to the obtained copolymer, and a hydrogenation reaction was performed at a hydrogen pressure of 0.7 MPa and a temperature of 65 ° C. After completion of the reaction, methanol is added, and then octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate as a stabilizer is added in an amount of 0.3% by weight based on the weight of the polymer A hydrogenated block copolymer (hereinafter referred to as polymer 1) was obtained. The hydrogenation rate of polymer 1 was 97%. As a result of DSC measurement, there was no crystallization peak.

Reference Example 3: Preparation of hydrogenated block copolymer Copolymerization was carried out in the same manner as in Reference Example 2.
After charging 10 parts by weight of cyclohexane into the reactor and adjusting the temperature to 70 ° C, n-butyllithium is 0.090% by weight with respect to the weight of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor), TMEDA was added in an amount of 0.7 mol with respect to 1 mol of n-butyllithium, and then a cyclohexane solution containing 20 parts by weight of styrene as a monomer (monomer concentration: 22% by weight) was added over about 3 minutes. Was allowed to react for 30 minutes while adjusting to about 70 ° C.
Next, a cyclohexane solution (monomer concentration of 22% by weight) containing 33 parts by weight of butadiene and 47 parts by weight of styrene is continuously fed to the reactor at a constant rate over 60 minutes to obtain a living polymer as a copolymer. It was. During this time, the reactor internal temperature was adjusted to about 70 ° C.
Next, 0.5 mol of the living polymer of the obtained copolymer was reacted with n-butyllithium used as a coupling agent for ethyl benzoate as a coupling agent to obtain a copolymer. The resulting copolymer had a styrene content of 67% by weight, a styrene polymer block content of 20% by weight, and a vinyl content in the butadiene portion of 23%. The copolymer had a weight average molecular weight of 19,000,000 and a molecular weight distribution of 1.4.
Next, a hydrogenation reaction was performed in the same manner as in Reference Example 2 to obtain a hydrogenated block copolymer (hereinafter referred to as “polymer 2”). The hydrogenation rate of polymer 2 was 99%. As a result of DSC measurement, there was no crystallization peak.

II. Preparation of flame retardant composition In Examples 1 to 7 and Comparative Example 1, flame retardant compositions were produced.
(Examples 1-6, Comparative Example 1)
Each composition was mixed with the formulation shown in Table 1, kneaded with a twin-screw extruder (device name; PCM30 <manufactured by Ikekai Tekko Co., Ltd.>), and pelletized to obtain a composition. The extrusion conditions were a cylinder temperature of 230 ° C. and a rotation speed of 300 rpm. The obtained composition was compression molded to prepare a sheet having a thickness of 2 mm, and various measurements were performed using this sheet. The results are shown in Table-1.
The components used are shown below.
(A) Hydrogenated block copolymer Polymers 1 and 2 prepared in Reference Examples 2 and 3 were used.
(B) Modified elastomer / M-SEBS: Tuftec M1943 {Maleic anhydride-modified styrene-ethylene / butylene-styrene copolymer <Asahi Kasei Co., Ltd.>}
(C) Inorganic filler / water mug-1: Kisuma 5A {Stearic acid-treated magnesium hydroxide <Kyowa Chemical Industry Co., Ltd.>}
Water mug-2: Kisuma 5L {Magnesium hydroxide treated with silane coupling agent <Kyowa Chemical Industry Co., Ltd.>}
(D) Olefin resin / PP-1: CJ700 {Homo PP (MFR = 10) <Mitsui Sumitomo Polyolefin Co., Ltd.>
PP-2: PC630A {Random PP (MFR = 7.5) <manufactured by Sun Allomer Co., Ltd.>}
(E) Rubber softener / paraffin oil: Diana Process Oil PW380 {made by Idemitsu Kosan Co., Ltd.}

The physical properties of the flame retardant composition were measured by the following methods.
II-1) Hardness The value after 10 seconds was measured with a durometer type A according to JIS-K-6253.
II-2) Flexibility, Tensile Strength, Elongation Tensile strength, stress at 100% stretching (hereinafter referred to as “100% Mo”), and elongation at break were measured according to JIS-K-6251. The tensile speed was 500 mm / min and the measurement temperature was 23 ° C. 100% Mo is a measure of flexibility. The smaller the 100% Mo, the better the flexibility.
II-3) Whitening resistance with scratch resistance Pencil hardness was measured according to the pencil scratch test of JIS-K-5400. The load was 200 g. It was judged that the higher the hardness, the better the whitening resistance with scratches.
II-4) Flame retardancy A flammability test according to UL94 was performed (test piece thickness; 2 mm). And ranking was performed based on the criteria of UL94.

  The flame retardant composition of the present invention has flame retardancy and is excellent in mechanical properties such as flexibility and tensile strength, and whitening resistance with scratches. Taking advantage of this characteristic, it can be suitably used for various applications where flame retardancy is required and for various applications where a soft vinyl chloride resin is used. Specifically, it can be suitably used as a coating material for electric wires such as home appliance parts and automobile parts, a coating material such as a power cable, a communication cable, and a power transmission cable, a building material, and the like.

Claims (2)

(A) At least one hydrogenation obtained by hydrogenating a polymer block (A) composed of at least two vinyl aromatic compounds and a non-hydrogenated random copolymer block composed of a conjugated diene compound and a vinyl aromatic compound 20 to 60% by weight of a hydrogenated block copolymer comprising the copolymer block (B) and having the following characteristics (1) to (5):
(1) The content of the vinyl aromatic compound is more than 40% by weight and less than 95% by weight with respect to the weight of the hydrogenated block copolymer,
(2) The content of the polymer block (A) is 5 to 60% by weight based on the weight of the hydrogenated block copolymer,
(3) The weight average molecular weight is 30,000 to 1,000,000,
(4) The hydrogenation rate of the double bond based on the conjugated diene compound is 75% or more,
(5) In the differential scanning calorimetry (DSC) chart obtained for the hydrogenated block copolymer, crystallization due to the at least one hydrogenated copolymer block (B) in the range of -20 to 80 ° C. There are virtually no peaks,
(B) 1-20% by weight of a styrenic modified elastomer in which an atomic group having an acid anhydride group is bonded by graft modification or terminal modification,
(C) 30 to 62% by weight of an inorganic filler comprising a metal hydroxide,
A flame retardant composition comprising:
However, the “Differential Scanning Calorimetry (DSC) chart” uses a DSC apparatus to increase the temperature from room temperature to 150 ° C. at a temperature increase rate of 30 ° C./min, and then to −100 ° C. at a temperature decrease rate of 10 ° C./min. Is a chart in which the crystallization curve was measured by lowering the temperature to “No substantial crystallization peak due to the hydrogenated copolymer block (B) in the range of −20 to 80 ° C.” In the range, a peak due to crystallization of the hydrogenated copolymer block (B) does not appear, or a peak due to crystallization is observed, but the crystallization peak heat quantity due to the crystallization is less than 3 J / g. It means that there is. 2. The flame retardancy according to claim 1, wherein 1 to 20 parts by weight of (d) olefin resin is further blended with respect to 100 parts by weight of the total amount of (a), (b) and (c). Composition.