JP4700779B2 - Flame retardant resin composition - Google Patents

Description

【００２８】
２．重合体組成物の物性測定方法
（１）酸素指数：ＪＩＳ Ｋ７２０１に準拠
難燃性の指標として評価
（２）シェル形成：酸素指数測定時のサンプルの燃焼状況を目視で観察し、下記の判定基準で評価を行った。
○：シェルを形成し、シェル自体が強固なもの
×：溶融しながら流れ落ちるもの（ドリップするもの）
（３）引張特性：ＪＩＳ Ｋ６７６０に準拠
試験片：ＪＩＳ Ｋ６３０１ ３号ダンベル １ｍｍ厚
（４）メルトフローレート（ＭＦＲ）：ＪＩＳ Ｋ６７６０に準拠
樹脂温度１９０℃、荷重２１６０ｇ
（５）外観：成形性の指標としてＭＦＲ測定時のストランドの状態を目視で観察し、下記の判定基準で評価を行った。
○:ストランドの肌がスムーズ
×：ストランドの肌がガタガタ
（６）Ｘ値＝ａＡ／（ａＡ＋ｃＢ）
Ｙ値＝（ｂＡ＋ｄＢ）／１００
Ａ：オレフィン・不飽和カルボン酸アルキルエステル共重合体使用量（重量部）
ａ：上記共重合体中の不飽和カルボン酸アルキルエステル含量（モル％）
ｂ：上記共重合体中の他の極性モノマー含量(モル％)
Ｂ：エチレン・酢酸ビニル共重合体使用量（重量部）
ｃ：上記共重合体中の酢酸ビニル含量（モル％）
ｄ：上記共重合体中の他の極性モノマー含量（モル％）
【００２９】
［実施例１，３，４，参考例２，５］表２に示すような配合割合の原料樹脂１００重量部に、水酸化マグネシウム（Mg(OH)₂、協和化学工業株式会社製）１００重量部（参考例２のみ５０重量部）及び酸化防止剤（商品名：イルガノックス１０１０ チバスペシャルティ・ケミカルズ株式会社製）０．２重量部を配合し、小型加圧ニーダーで加熱混練後、６インチロールに投入し、ロール混練を行うことにより樹脂組成物を調製した。ロール混練後、分出しシートを作製した後、プレス成形により厚さ１ｍｍ及び３ｍｍのシートを作製し、引張特性、難燃性（酸素指数、シェル形成）、成形性の評価を実施した。結果を表２に示す。
【００３０】
【表２】

＊：伸びが大きく、測定不能
【００３１】
表２の結果から明らかなように、実施例１，３，４により得られた本発明の難燃性樹脂組成物は、従来のポリオレフィン系樹脂では到底達成できなかった難燃性（酸素指数、シェル形成性）、機械物性（強度、伸び）、成形性（ＭＦＲ、ストランド外観）が良好な組成物であった。
【００３２】
［比較例１］
樹脂成分としてＥＴ−１のみを使用した以外は実施例１と同様に試料の調製及び物性評価を実施した。表２に示すように酸素指数値が低かった。
【００３３】
［比較例２］
樹脂成分としてＶＡ−３のみを使用した以外は実施例５と同様に試料の調製と物性評価を実施した。表２に示すように、充分な難燃性（酸素指数、シェル形成）が得られなかった。
【００３４】
［比較例３］
実施例５と対比するためＥＴ−３の代わりに不飽和カルボン酸アルキルエステルを含有しない共重合体ＧＡ−１を使用した以外は実施例５と同様に試料の調製と物性評価を実施した。表２に示すように、ＧＡ−１の配合では難燃性（酸素指数、シェル形成）において実施例５のような優れた結果は得られなかった。
【００３５】
［比較例４］
樹脂成分としてＥＴ−４のみを使用した以外は実施例１と同様に試料の調製と物性評価を実施した。表２に示すように、比較的良好な難燃性が得られたが、樹脂強度が極めて低く実用的でない。
【００３６】
【発明の効果】
本発明によれば、加工性、機械的強度、難燃性に優れ、燃焼時のシェル形成性に優れた安価な樹脂組成物を提供することができる。本発明の難燃性樹脂組成物はこのような特性を生かして、押出成形、射出成形、圧縮成形、中空成形、発泡成形等の各種成形方法により種々の形状の成形品にして利用することができる。また電子線照射による架橋などの加工を行うこともできる。例えば、人工芝、マット、止水シート、トンネルシート、ルーフィング等の土木分野、ホース、チューブ等のパイプ用途、パッキン、制振シートなどの家電用途、カーペットの裏打ち材、ドアパネル防水シート、泥よけ、モール等の自動車用途、家具、壁紙、床材、発泡シート等の建材用途、通信ケーブル、電力ケーブル、収縮チューブ等のケーブル用途などの各分野で使用することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flame retardant resin composition having excellent moldability and mechanical strength, and excellent shell forming properties and flame retardancy during combustion.
[0002]
[Prior art]
Olefin polymers are widely used as electrical insulating materials because they are generally excellent in electrical characteristics, mechanical properties, processability, and the like. Particularly for applications such as electric wires and cables, ethylene / unsaturated ester random copolymers are widely used because of a good balance of strength, low temperature characteristics, scratch resistance, hardness and the like.
[0003]
Since such an ethylene copolymer is flammable, it needs to be flame retardant depending on the application, and for that reason, it has been dealt with in the past by blending a halogen-based flame retardant. However, such a compound has a problem of generating a harmful gas during combustion, and therefore, in recent years, a formulation in which a metal hydroxide flame retardant such as non-halogenated magnesium hydroxide or aluminum hydroxide is blended is adopted. It has become. However, metal hydroxide flame retardants cannot exert a sufficient flame retardant effect unless they are incorporated in a considerably large amount, and often sacrifice the processability, scratch resistance, and other mechanical properties of ethylene copolymers. There was something to do.
[0004]
For example, a flame retardant resin composition based on an ethylene / unsaturated carboxylic acid ester copolymer typified by an ethylene / ethyl acrylate copolymer has the advantage of excellent shell formation during combustion, The flame retardancy and toughness of the base polymer are low, making it difficult to blend a large amount of flame retardant. That is, if the blending amount of the flame retardant is small, a sufficient flame retardant effect cannot be exerted, and if the blending amount of the flame retardant is increased, the workability is deteriorated and the mechanical strength is reduced, so the applicable range. Was restricted.
[0005]
The ethylene / vinyl acetate copolymer has the most excellent toughness among the ethylene copolymers, and has a filler loading property and flexibility capable of blending a large amount of flame retardant. Although it is an inexpensive and attractive material compared to unsaturated carboxylic acid ester copolymers, the flame retardant resin composition based on it is not sufficiently flame retardant, and a shell is formed especially during combustion. There was a major drawback that it was difficult to drip and the range of application was similarly limited.
[0006]
[Problems to be solved by the invention]
Therefore, the present inventor has studied to improve the shell-forming property at the time of combustion in a metal hydroxide flame retardant blending system of the copolymer in order to make use of the excellent properties of the ethylene / vinyl acetate copolymer. . As a result, the ethylene / vinyl acetate copolymer has excellent characteristics by blending ethylene / unsaturated carboxylic acid alkyl ester copolymer in a specific ratio or introducing a specific polar group. It has been found that flame retardancy and shell formation during combustion can be improved while maintaining the above properties, and proposed in Japanese Patent Application No. 11-293648.
[0007]
As a result of further investigations thereafter, ethylene-vinyl acetate copolymers were blended with ethylene-free olefin / unsaturated carboxylic acid alkyl ester copolymers containing other polar monomers as copolymerization components, or other polarities. By combining an ethylene / vinyl acetate copolymer copolymerized with a monomer and an olefin / unsaturated carboxylic acid alkyl ester copolymer, it has excellent processability, toughness, flame retardancy, and shell formation during combustion. The present inventors have found that a flame retardant resin composition can be obtained, and have reached the present invention.
[0008]
[Means for Solving the Problems]
That is, the present invention relates to an olefin / unsaturated carboxylic acid alkyl ester having an unsaturated carboxylic acid alkyl ester content of a mol% , which is selected from ethylene / ethyl acrylate binary copolymer and ethylene / methyl acrylate binary copolymer. copolymer a parts by weight and an ethylene / vinyl acetate / carbon monoxide terpolymer, selected from ethylene / vinyl acetate / glycidyl methacrylate terpolymer, a vinyl acetate content of c mol%, of other It consists of ethylene / vinyl acetate copolymer B parts by weight of polar monomer content of d mol%, (A) / (B) = 90/10 to 95/5, a = 2 to 40 (mol%), c = 10 (mol%) or less, not more than d = 20 (mol%), to produce a aA / (aA + cB) = 0.05~0.97, raw material resin satisfying the dB /100=0.1～20, the original Metal hydroxide flame retardant blended system of ethylene / unsaturated ester random copolymer comprising blending 25 to 250 parts by weight of metal hydroxide as flame retardant inorganic compound per 100 parts by weight of resin The present invention relates to a method for improving shell formability during combustion.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The olefin / unsaturated carboxylic acid alkyl ester copolymer used in the present invention comprises a binary copolymer comprising an olefin and an unsaturated carboxylic acid alkyl ester, or an olefin, an unsaturated carboxylic acid alkyl ester, and another polar monomer. If the ethylene / vinyl acetate copolymer to be blended together is a multi-component copolymer as described later, both can be used, but the ethylene / vinyl acetate copolymer is binary. In the case of a copolymer, a multi-component copolymer, particularly a multi-component copolymer of olefins other than ethylene is used.
[0010]
Examples of the olefin in the copolymer include aliphatic monoolefins such as ethylene, propylene, 1-butene, 1-hexene and 4-methyl-1-pentene, aliphatic diolefins such as butadiene and isoprene, styrene, α- An aromatic olefin such as methylstyrene can be used.
[0011]
As the unsaturated carboxylic acid alkyl ester constituting the copolymer, an alkyl ester having 1 to 12 carbon atoms, particularly about 1 to 8 carbon atoms of unsaturated carboxylic acid such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, etc. It is preferred to use. More specifically, examples include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, dimethyl maleate, diethyl maleate, and the like. Can do.
[0012]
Other polar monomers that can constitute the copolymer are monomers other than vinyl acetate and unsaturated carboxylic acid alkyl esters that wait for polar groups containing elements such as O, N, S, and P. Unsaturated carboxylic acid esters other than unsaturated carboxylic acid alkyl esters, for example, glycidyl acrylate, glycidyl methacrylate, etc., unsaturated dicarboxylic acid half esters, such as monomethyl maleate, monoethyl maleate, etc., dicarboxylic anhydrides, Examples thereof include maleic anhydride and other carbon monoxide, acrylonitrile, sulfur dioxide and the like.
[0013]
When the olefin / unsaturated carboxylic acid alkyl ester copolymer is a binary copolymer of an olefin and an unsaturated carboxylic acid alkyl ester, it is preferably an ethylene copolymer, for example, an unsaturated carboxylic acid alkyl ester content. 1 to 50 mol%, particularly 2 to 40 mol% of ethylene / unsaturated carboxylic acid alkyl ester is preferably used.
[0014]
A preferred example of the olefin / unsaturated carboxylic acid alkyl ester copolymer is a copolymer of ethylene including an olefin, an unsaturated carboxylic acid alkyl ester, and another polar monomer. Copolymers having an acid alkyl ester content of 1 to 50 mol%, particularly 2 to 40 mol%, and other polar monomers of 20 mol% or less, particularly 15 mol% or less are preferably used.
[0015]
The binary or multi-component copolymer of ethylene can be obtained, for example, by radical copolymerization under high temperature and high pressure.
[0016]
Other preferred examples of the multi-component copolymer include a copolymer obtained by copolymerizing a diene, an unsaturated carboxylic acid alkyl ester, and another polar monomer such as acrylonitrile. In such a copolymer, for example, the unsaturated carboxylic acid alkyl ester content is in the range of 1 to 80 mol%, particularly 2 to 60 mol%, and the content of other polar monomers is 1 to 95 mol%, particularly 10 It is preferable to be in the range of ˜90 mol%. In addition, in the presence of ethylene / unsaturated carboxylic acid alkyl ester copolymer or ethylene / unsaturated carboxylic acid alkyl ester / maleic acid copolymer, other polar monomers such as acrylonitrile and aromatic olefins such as styrene The graft copolymer which copolymerized these etc. can be mentioned.
[0017]
As such an olefin / unsaturated carboxylic acid alkyl ester copolymer, one having an MFR of 0.1 to 150 g / 10 min, preferably 0.5 to 100 g / 10 min at 190 ° C. and 2160 g load is used. It is good.
[0018]
The ethylene-vinyl acetate copolymer used in the present invention is a binary copolymer composed of ethylene and vinyl acetate or a multi-component copolymer composed of ethylene, vinyl acetate and other polar monomers, and is blended together. When the olefin / unsaturated carboxylic acid alkyl ester copolymer is a multi-component copolymer, any can be used, but when the olefin / unsaturated carboxylic acid alkyl ester copolymer is a binary copolymer, the multi-component copolymer can be used. Only copolymers are used.
[0019]
In the case where the ethylene / vinyl acetate copolymer is a multi-component copolymer, other polar monomers include monomers other than vinyl acetate and unsaturated carboxylic acid alkyl esters, and elements such as O, N, S, and P. Having a polar group containing, for example, glycidyl acrylate, glycidyl methacrylate, etc., unsaturated dicarboxylic acid half esters, such as monomethyl maleate, monoethyl maleate, etc., dicarboxylic acid anhydrides, such as maleic anhydride, Other examples include carbon monoxide, vinyl alcohol, acrylonitrile, sulfur dioxide and the like. In such an ethylene copolymer, the ethylene content is 30 mol% or more, particularly 60% or more, the vinyl acetate content is 20 mol% or less, particularly 10 mol% or less, and the other polar monomer content is 70 mol% or less, especially Those of 20 mol% or less are preferred. As such an ethylene copolymer, it is preferable to use one having an MFR of 0.1 to 150 g / 10 min, particularly 0.2 to 100 g / 10 min at 190 ° C. and a load of 2160 g.
[0020]
In the copolymer component in the flame retardant resin composition of the present invention, the unsaturated carboxylic acid alkyl ester content of the olefin / unsaturated carboxylic acid alkyl ester copolymer is a mol%, the other polar monomer content is b mol%, When the blending amount is A parts by weight, the vinyl acetate content of the ethylene-vinyl acetate copolymer is c mol%, the other polar monomer content is d mol%, and the blending amount is B parts by weight, (A) / (B) = 5/95 to 95/5, where aA / (aA + cB) = 0.01 to 0.99, preferably 0.05 to 0.95, (bA + dB) / 100 = 0. It is in the range of 01 to 49, preferably 0.1 to 20 (provided that either one of b and d may be 0 as described above). That is, if these values are too small, the flame retardancy is poor, and the shell formation during combustion is not good. On the other hand, if these values are too large, the resin strength becomes weak or the moldability deteriorates.
[0021]
Examples of the flame retardant inorganic compound blended in the copolymer component comprising an olefin / unsaturated carboxylic acid alkyl ester copolymer and an ethylene / vinyl acetate copolymer include magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, Examples include fillers and reinforcing materials such as metal hydroxides such as hydrotalcite, silicate metal salts, borate metal salts, silica, alumina, calcium carbonate, talc, clay, zeolite, carbon black, and glass fiber. it can. When sufficient flame retardancy is required, it is preferable to use a metal hydroxide or a mixed inorganic compound that occupies at least 50% by weight of the metal hydroxide.
[0022]
Considering the miscibility of the inorganic compound and the appearance of the molded product obtained from the flame retardant resin composition, an inorganic compound having an average particle size of 0.05 to 20 μm, particularly about 0.1 to 5 μm is used. Is desirable. For the same reason, the surface of the inorganic compound is surface-treated with fatty acid, fatty acid amide, fatty acid salt, fatty acid ester, aliphatic alcohol, silane coupling agent, titanium coupling agent, silicon oil, phosphate ester, etc. Is preferably used.
[0023]
The compounding amount of the flame retardant inorganic compound is 25 to 250 parts by weight with respect to 100 parts by weight of the total amount of copolymer components composed of an olefin / unsaturated carboxylic acid alkyl ester copolymer and an ethylene / vinyl acetate copolymer, Preferably it is 50-200 weight part, More preferably, it is the range of 70-150 weight part. When the blending amount of the flame retardant inorganic compound is too small, it is difficult to impart sufficient flame retardancy, and when the blending amount is excessive, it is difficult to obtain a composition with good processability.
[0024]
The flame retardant resin composition of the present invention can be blended with other polymers as long as the object of the present invention is not impaired. Further, if necessary, a phosphorus-based flame retardant can be used in combination, or other various additives can be blended. Examples of such additives include antioxidants, light stabilizers, UV absorbers, flame retardant aids, pigments, dyes, lubricants, antiblocking agents, foaming agents, foaming aids, crosslinking agents, crosslinking aids, etc. Can be illustrated.
[0025]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In addition, the physical property test method of the raw material resin used in the Example and the comparative example and the obtained resin composition is shown below.
[0026]
1. Raw material resin of olefin / unsaturated carboxylic acid alkyl ester (ET-1 to ET-4), ethylene / vinyl acetate copolymer (VA-1 to VA-3) and other resin (GA-1) used as raw material resin Abbreviations, their compositions and MFR are shown in Table 1.
[0027]
[Table 1]

[0028]
2. Method of measuring physical properties of polymer composition (1) Oxygen index: evaluated as an index of flame retardancy in accordance with JIS K7201 (2) Shell formation: visually observing the combustion state of the sample at the time of measuring the oxygen index, and the following criteria Was evaluated.
○: A shell is formed, and the shell itself is strong. X: A shell that flows down while melting (drip)
(3) Tensile properties: JIS K6760 compliant Test piece: JIS K6301 No. 3 dumbbell 1 mm thickness (4) Melt flow rate (MFR): JIS K6760 compliant Resin temperature 190 ° C., load 2160 g
(5) Appearance: As an index of formability, the strand state during MFR measurement was visually observed and evaluated according to the following criteria.
○: The strand skin is smooth ×: The strand skin is rattling (6) X value = aA / (aA + cB)
Y value = (bA + dB) / 100
A: Amount of olefin / unsaturated carboxylic acid alkyl ester copolymer used (parts by weight)
a: Unsaturated carboxylic acid alkyl ester content (mol%) in the copolymer
b: Content of other polar monomer in the above copolymer (mol%)
B: Use amount of ethylene / vinyl acetate copolymer (parts by weight)
c: Vinyl acetate content (mol%) in the above copolymer
d: Content of other polar monomer in the copolymer (mol%)
[0029]
[Examples 1 , 3, 4, Reference Example 2, 5] 100 parts by weight of magnesium hydroxide (Mg (OH) ₂ , manufactured by Kyowa Chemical Industry Co., Ltd.) is added to 100 parts by weight of a raw material resin having a blending ratio as shown in Table 2. 6 parts by weight (50 parts by weight only for Reference Example 2) and 0.2 parts by weight of antioxidant (trade name: Irganox 1010, manufactured by Ciba Specialty Chemicals Co., Ltd.) The resin composition was prepared by carrying out roll kneading. After roll kneading, a dispensing sheet was prepared, and then 1 mm and 3 mm thick sheets were prepared by press molding, and evaluation of tensile properties, flame retardancy (oxygen index, shell formation), and formability was performed. The results are shown in Table 2.
[0030]
[Table 2]

*: The elongation is large and measurement is impossible. [0031]
As is apparent from the results in Table 2, the flame-retardant resin composition of the present invention obtained in Examples 1, 3, and 4 has flame retardancy (oxygen index, which cannot be achieved with conventional polyolefin resins at all). The composition was excellent in shell-forming properties, mechanical properties (strength, elongation), and moldability (MFR, strand appearance).
[0032]
[Comparative Example 1]
Sample preparation and physical property evaluation were carried out in the same manner as in Example 1 except that only ET-1 was used as the resin component. As shown in Table 2, the oxygen index value was low.
[0033]
[Comparative Example 2]
Sample preparation and physical property evaluation were performed in the same manner as in Example 5 except that only VA-3 was used as the resin component. As shown in Table 2, sufficient flame retardancy (oxygen index, shell formation) was not obtained.
[0034]
[Comparative Example 3]
For comparison with Example 5, sample preparation and physical property evaluation were carried out in the same manner as in Example 5 except that copolymer GA-1 containing no unsaturated carboxylic acid alkyl ester was used instead of ET-3. As shown in Table 2, excellent results as in Example 5 were not obtained in the flame retardancy (oxygen index, shell formation) with GA-1.
[0035]
[Comparative Example 4]
Sample preparation and physical property evaluation were carried out in the same manner as in Example 1 except that only ET-4 was used as the resin component. As shown in Table 2, relatively good flame retardancy was obtained, but the resin strength was extremely low and not practical.
[0036]
【The invention's effect】
According to the present invention, it is possible to provide an inexpensive resin composition that is excellent in processability, mechanical strength, and flame retardancy, and excellent in shell formation during combustion. The flame retardant resin composition of the present invention can be used to form molded products of various shapes by various molding methods such as extrusion molding, injection molding, compression molding, hollow molding, foam molding, etc., taking advantage of such characteristics. it can. Moreover, processing, such as bridge | crosslinking by electron beam irradiation, can also be performed. For example, artificial turf, mats, waterproof sheets, tunnel sheets, roofing and other civil engineering fields, hoses, pipes such as tubes, packing, vibration control sheets and other household appliances, carpet backing, door panel tarpaulins, mudguards It can be used in various fields such as automotive applications such as malls, building materials such as furniture, wallpaper, flooring, and foam sheets, and cable applications such as communication cables, power cables, and shrinkable tubes.

Claims (1)

Ethylene / ethyl acrylate binary copolymer, ethylene / are selected from methyl acrylate binary copolymer, olefin-unsaturated carboxylic acid alkyl ester copolymer A weight of the unsaturated carboxylic acid alkyl ester content of a mole% parts, and an ethylene / vinyl acetate / carbon monoxide terpolymer, selected from ethylene / vinyl acetate / glycidyl methacrylate terpolymer, a vinyl acetate content of c mol%, other polar monomer content d Comprising parts by weight of ethylene / vinyl acetate copolymer B of mol%, (A) / (B) = 90/10 to 95/5, a = 2 to 40 (mol%), c = 10 (mol%) or less , d = 20 (mol%) or less, aA / (aA + cB) = 0.05~0.97, to produce a raw material resin satisfying the dB /100=0.1~20, the raw material resin 100 parts by weight Or a metal hydroxide as a flame retardant inorganic compound in a proportion of 25 to 250 parts by weight, at the time of combustion in an ethylene / unsaturated ester random copolymer metal hydroxide flame retardant blending system Method for improving shell formation.