JP3601110B2 - Acrylic elastomer vulcanized molded product - Google Patents

Description

以上の各配合成分を、通常の混練方法に従ってオープンロールミルで混練し、得られたアクリル系エラストマー組成物を１８０℃で８分間プレス加硫（一次加硫）した後、１７５℃で４時間オーブン加硫（二次加硫）して、厚さ２ｍｍのアクリルゴムシートを得た。
【００２２】
得られたアクリルゴムシートから１０×２０ｍｍの試験片を切り出し、この試験片をメタノール洗浄した後、２枚のメタノール洗浄金属板（表面を＃１５０サンドペーパーで研磨した２５×２５×０．６ｍｍのＳ−２０Ｃ板）の間に挾み込み、２５％、１５０℃、７０時間の条件下で圧縮した後室温下に２４時間放置し、２枚の金属板をアクリルゴムシートから１００ｍｍ／分の速度で剥がすときの剥離力を固着力として測定した。得られた結果は、次の表１に示される。

【００２３】
実施例２
実施例１において、フッ素化ホスホン酸塩として下記のものを５重量部用いてアクリルゴムシートを作製し、金属板との間の剥離力を測定すると、次の表２に示されるような結果が得られた。

【００２４】
実施例３
実施例１において、下記配合処方Ｂ〜Ｆのアクリル系エラストマー組成物を用いてアクリルゴムシートを作製し、金属板との間の剥離力を測定すると、固着力はいずれも０ ｋｇであった。

【００２５】
注） 老化防止剤ＣＤ：大内新興化学製品ノクラックＣＤ；４，４´−ビス（α，α−ジメ チルベンジル）ジフェニルアミン
加硫剤ＴＣＹ：三協化成製品Ｚｉｓｎｅｔ Ｆ；トリチオール−ｓ−トリアジン
加硫促進剤ＢＺ：大内新興化学製品ノクセラーＢＺ；ジブチルジチオカルバ ミン酸亜鉛
加硫剤ＡＢ：大内新興化学製品バルノックＡＢ；安息香酸アンモニウム
加硫促進剤Ｄ：大内新興化学製品ノクセラーＤ；１，３−ジフェニルグアニジン
共架橋剤ＰＭ：大内新興化学製品バルノックＰＭ；Ｎ，Ｎ´−ｍ−フェニレンビスマレイミド
加硫剤Ｆ４０：日本油脂製品ペロキシモンＦ４０；α，α´−ビス（第３ブチルペルオキシ−ｍ−イソプロピル）ベンゼン
【００２６】
比較例１
実施例１において、フッ素化ホスホン酸塩の代わりに、下記の化合物５重量部を用いてアクリルゴムシートを作製し、金属板との間の剥離力を測定すると、次の表３に示されるような結果が得られた。

【００２７】
比較例２
実施例３の配合処方Ｆにおいて、フッ素化ホスホン酸塩を配合しないものの固着力は１２．０ｋｇであった。[0001]
[Industrial applications]
The present invention relates to a vulcanized acrylic elastomer molded article. More specifically, the present invention relates to a vulcanized acrylic elastomer molded article having an anti-sticking property to metals and the like.
[0002]
[Prior art]
Acrylic elastomers are used as molding materials for sealing rubber such as packings and O-rings, and vulcanized molded products are made of materials that come into direct contact therewith, such as metals such as cast iron, aluminum, SUS and soft iron, and polyamide resins. In some cases, only a phenomenon in which rubber adheres to a resin such as a phenol resin and the sealing performance is deteriorated.
[0003]
Here, the sticking means that the rubber for contact and the contact material are compressed by about 10 to 40%, and the rubber and the contact material react when left in the air or the used oil at a certain temperature for a certain period of time. Although it refers to a state where it does not come off even if it is going to come off, cast iron and soft iron are particularly problematic in the above various contact materials in terms of sticking.
[0004]
Various methods have been proposed to solve the problem of the sticking as described below, but none of them is satisfactory.
(1) A method in which a relatively large amount of a plasticizer, a lubricant, or the like is blended in rubber, and the rubber is bleeded or bloomed, and is not brought into direct contact with a mating material. The blooming alone does not only result in insufficient prevention of sticking, but also greatly reduces the rubber properties.
(2) Method of attaching a solid lubricant or silicone coating agent to rubber In the method of attaching a solid lubricant, a solid lubricant such as graphite or molybdenum disulfide is easily removed, and not only does the performance become unstable, but also in oil or the like. There is a possibility that these solid lubricants are mixed and become foreign matters. Similar problems are seen with silicone coatings.
(3) A method of coating a sealing material as a composition dispersed in a solvent based on a rubber-based binder and a solid lubricant This method generally has poor adhesion to the sealing material and is sufficiently effective in preventing sticking. Has no effect. Also, the processing cost becomes very high.
(4) Method of fluorinating the surface with fluorine gas or the like This method is excellent in terms of sticking resistance, but has disadvantages in terms of processing cost.
(5) Method of curing the surface This method cures the surface by treating it with a polythiol compound, amines, organic peroxides, etc., and is excellent in terms of sticking resistance. There are problems such as cracks.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide an acrylic elastomer vulcanized molded article containing an anti-sticking agent, which has excellent anti-sticking properties and does not substantially reduce rubber physical properties.
[0006]
[Means for Solving the Problems]
The object of the present invention is to provide a fluorinated phosphonic acid represented by the general formula RfRnPO (OH) ₂ in 100 parts by weight of an acrylic elastomer, wherein Rf is a polyfluorocarbon group or a perfluoropolyether group, and R is the number of carbon atoms. 1-6 alkylene group, a phenylene group, a oxyphenylene group or a sulfonamido ethylene radical, n is vulcanized from 0 or an acrylic elastomer composition a salt of 1 which is] and 0.1 to 20 wt parts Achieved by vulcanized molded articles.
[0007]
The fluorinated phosphonate used as an anti-sticking agent in the present invention is applied as an external mold release agent in a molding die when heating or vulcanizing polyurethane prepolymer, acrylic rubber, fluororubber, or the like. Has already been proposed by the applicant.
[0008]
However, when a fluorinated phosphonate is used as an external mold release agent, even if it is a main component, it is not always used alone, but always requires the coexistence of other components. That is, first, a composition in which oil is added to a fluorinated phosphonate has been proposed as a mold release agent (Japanese Patent Publication No. 2-45572). Riding is not uniform, and there is a problem that the oil component usually becomes oil droplets, and the oil component in the form of oil droplets makes the surface of the molded product uneven, and in order to solve such problems, oil or wax is used. At the same time, it has been proposed to add a perfluoroalkyl group-containing (meth) acrylic acid polymer (JP-A-3-48846). In addition, when the composition to which the oil is added is used as a release agent, the surface of the molded product has a slippery and slippery characteristic of silicone oil. It is not easy to fix for post-processing such as removal of the seal and accurate cutting of the seal part, and as a result, the post-processability is significantly impaired. A releasing agent in which a phosphonate and a wax are dissolved or dispersed in an organic medium or an aqueous medium has also been proposed (JP-A-3-78244).
[0009]
Despite these various improvements, the fluorinated phosphonate has to be used as a dispersion system because of its low solubility in solvents having a small polarity, which tends to cause uneven coating. In addition, problems such as poor preservation due to the tendency to form precipitates still remain. Therefore, it has been proposed to use a monoesterified salt of fluorinated phosphonic acid in combination with wax or oil (see JP-A-4-4923). Gazette).
[0010]
When a fluorinated phosphonic acid or a salt of a monoester thereof is used as an external release agent in this way, it is not used alone, but for example, a fluorinated phosphonate alone is used as an external release agent. Although it can be used as an agent, in that case, even though the release effect from the mold is observed, the adhesion to the surface of the vulcanized molded product is small. I can't see it. It is also conceivable to apply the salt of the fluorinated phosphonic acid monoester as an aqueous dispersion or an organic solvent dispersion to the surface of the vulcanized molded product. Cannot be fixed.
[0011]
However, in the present invention, by internally adding a fluorinated phosphonate to an acrylic elastomer, it becomes possible to use it alone, and furthermore, the problem when used as an external mold release agent is solved. In addition to a sufficient mold release effect from the mold, a uniform stable layer of fluorinated phosphonate can be formed on the surface of the vulcanized molded product, and the anti-sticking property is also improved. It was found that.
[0012]
As the acrylic elastomer, generally, (a) an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, (b) an alkoxyalkyl acrylate having an alkoxyalkylene group having 2 to 8 carbon atoms, (c) a general formula CH ₂ ＣＲCRCOO [(CH ₂ ) ₅ COO] nCH ₂ CH ₂ CN (R: hydrogen atom or methyl group, n: an integer of 1 or more and 1 to 5 on average) or (d) a general formula CH ₂ = CR ¹ COO (R ² COO) nR ³ (R ¹ : hydrogen atom or methyl group, R ² : alkylene group having 3 to 20 carbon atoms, R ³ : hydrocarbon group having 1 to 20 carbon atoms or substituted hydrocarbon At least one (co) polymer of a (meth) acrylate represented by the following formula: (n: 1 to 20) is used, and preferably (e) less Both kind of about 10 wt% of crosslinking group-containing monomer, such as: less, preferably a copolymer is used which is copolymerized more than about 5 wt%.
(A) Reactive halogen-containing vinyl monomer (b) Epoxy group-containing vinyl monomer (c) Carboxyl group-containing vinyl monomer (including monoalkyl maleate)
(D) Diene monomer (e) Hydroxyl group-containing vinyl monomer (f) Amide group-containing vinyl monomer In these (co) polymers, some of the components (a) to (c) Specifically, up to about 35% by weight can be substituted with another copolymerizable vinyl monomer and copolymerized.
[0013]
As the acrylic elastomer, the following may be used.
Ethylene-acrylate copolymer elastomer:
This is a copolymer elastomer of about 60 to 20% by weight of ethylene and about 40 to 80% by weight of an alkyl (meth) acrylate containing an alkyl group having 1 to 8 carbon atoms. The contained monomer can be copolymerized at a ratio of about 10% by weight or less.
Ethylene-acrylate-vinyl acetate copolymer elastomer:
This is a copolymer elastomer of about 45 to 5% by weight of ethylene, about 5 to 90% by weight of at least one of the components (a) to (d), and about 45 to 5% by weight of vinyl acetate. The component crosslinkable group-containing monomer can be copolymerized at a ratio of about 10% by weight or less.
Acrylate-unsaturated nitrile-conjugated diene copolymer elastomer and hydrogenated product thereof:
About 5 to 75% by weight of at least one of the components (a) to (d), 60 to 10% by weight of an unsaturated nitrile such as (meth) acrylonitrile, ethacrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile, A copolymer elastomer containing 15 to 85% by weight of a conjugated diene monomer such as 2-chlorobutadiene or 2-methylbutadiene, or a hydrogenated product obtained by hydrogenating unsaturated bonds thereof by about 10 to 100%.
[0014]
Further, these at least one acrylic elastomer may be blended with about 95 parts by weight or less, preferably about 50 parts by weight or less, of 100 parts by weight of the elastomer, for example, natural rubber, SBR, polybutadiene rubber, polyisoprene. It can also be used as a blend in which rubber, butyl rubber, NBR, chloroprene rubber, EPDM, acrylic rubber, fluorine rubber, chlorinated polyethylene rubber, urethane rubber, epichlorohydrin rubber, etc. are substituted.
[0015]
About 0.1 to 20 parts by weight, preferably about 0.5 to 10 parts by weight, of a fluorinated phosphonate per 100 parts by weight of these acrylic elastomers or blends thereof with other elastomers is blended. Is done. If the compounding ratio is less than this, no particular effect of preventing sticking is observed, while if used at a higher ratio, the physical properties of the material are deteriorated, which is not practical.
[0016]
In the fluorinated phosphonic acid represented by the above general formula, the following are used as Rf and R.
Rf: As the polyfluorocarbon group, a perfluoroalkyl group such as C ₆ F ₁₃ , C ₈ F ₁₇ , C ₁₀ F ₂₁ , C ₁₂ F ₂₅ , C ₁₄ F ₂₉ is generally used, and one unsaturated group is used there. Those in which a bond is introduced, those in which a part of a fluorine atom is replaced by a hydrogen atom or a chlorine atom, and the like are also used. Further, the perfluoroalkyl group has a trifluoromethyl group in the side chain
C ₂ F ₅ [CF (CF ₃ ) CF ₂ ] n (CF ₂ CF ₂ ) m-
CF (CF ₃ ) ₂ (CF ₂ CF ₂ ) n-
And so on. These polyfluorocarbon groups have 1 to 32 carbon atoms, preferably 4 to 16 carbon atoms.
The following are used as the perfluoropolyether group, for example.
CF ₃ O (CF ₂ CF ₂ CF ₂ O) n-
C ₂ F ₅ O (CF ₂ CF ₂ CF ₂ O) n-
C ₃ F ₇ O [CF (CF ₃ ) CF ₂ O] n-
F (CF ₂ CF ₂ O) n (CF ₂ O) m-
CF ₃ O (CF ₂ CF ₂ O) n (CF ₂ O) m-
_{CF 3 O (CF 2 CF 2} O) n (CF 2 O) m [CF (CF 3) CF 2 O] k-
_{C 2 F 5 O (CF 2} CF 2 O) n (CF 2 O) m [CF (CF 3) CF 2 O] k-
Here, n, m, and k are integers of 1 or more, preferably 1 to 100.
R: an alkylene group having 1 to 6 carbon atoms such as methylene, ethylene, trimethylene, propylene-CH (CH ₃ ) CH _2- , tetramethylene, hexamethylene or oxyphenylene group or oxyphenylene group
_{-SO 2 NH C 2 H 4 -} , - SO 2 N (CH 3) C 2 H 4 -, - SO 2 N (C 3 H 7) C 2 H 4 - sulfonamide ethylene group [0017], such as
As such a salt of the fluorinated phosphonic acid, a metal salt, an ammonium salt or an amine salt is used. Examples of the metal salt include a Group IA metal salt such as sodium, potassium and lithium; a Group IIA metal salt such as barium, magnesium and calcium; a Group IIB metal salt such as zinc; and a Group IVB metal such as zirconium. And the like. The amine salt is substituted with an alkyl group or cycloalkyl group having about 1 to 10 carbon atoms such as monomethylamine, monoethylamine, monoisopropylamine, dimethylamine, diethylamine, diisopropylamine, di-n-butylamine, dicyclohexylamine, and triethylamine. Mono-substituted amine, di-substituted amine or tri-substituted amine salt, mono-substituted amine substituted with hydroxyalkyl group having about 1 to 10 carbon atoms such as monoethanolamine, diethanolamine, diisopropanolamine, triethanolamine, etc. Salts of amines or tri-substituted amines, salts of aromatic amines such as pyridine and the like are used. These salts can be monosalts represented by the general formula RfRnPO (OH) (OM) or disalts represented by RfRnPO (OM) ₂ (M: metal, ammonium base or amine base).
[0018]
In the acrylic elastomer composition containing the above-mentioned acrylic elastomer or a blend thereof and a fluorinated phosphonate as essential components, various necessary compounding agents including a crosslinking agent (vulcanization aid, reinforcing agent, (Fillers, stabilizers, plasticizers, pigments, etc.) are blended and kneaded with a roll, Banbury mixer, etc., and then vulcanized according to the crosslinking conditions generally applied to commonly used acrylic elastomers or blends thereof. Is Various crosslinking agents are used as described in JP-A-63-218751, depending on the type of the crosslinking group contained in the acrylic elastomer. In addition, peroxide vulcanization is possible regardless of the presence or absence of a crosslinkable group.
[0019]
【The invention's effect】
By blending fluorinated phosphonates with acrylic elastomers or blends thereof and vulcanizing them, if the vulcanized molded products come into direct contact with metal materials or resin molded products, the type of polymer and vulcanization An effective anti-sticking action is exhibited therewith without being affected by the system. Therefore, the vulcanized molded product of the acrylic elastomer of the present invention having such an anti-sticking effect can be effectively used as a sealing material or the like used in a portion which is directly in contact with a metal material or a resin molded product.
[0020]
【Example】
Next, the present invention will be described with reference to examples.
[0021]

The above components are kneaded by an open roll mill according to a usual kneading method, and the obtained acrylic elastomer composition is press-cured (primary vulcanization) at 180 ° C. for 8 minutes, and then oven-cured at 175 ° C. for 4 hours. By vulcanization (secondary vulcanization), an acrylic rubber sheet having a thickness of 2 mm was obtained.
[0022]
A 10 × 20 mm test piece was cut out from the obtained acrylic rubber sheet, and the test piece was washed with methanol. After that, two methanol-washed metal plates (25 × 25 × 0.6 mm of a surface polished with # 150 sandpaper) were used. S-20C plate), compressed under the conditions of 25%, 150 ° C. and 70 hours, allowed to stand at room temperature for 24 hours, and the two metal plates were separated from the acrylic rubber sheet at a speed of 100 mm / min. The peeling force when peeling was measured as the fixing force. The results obtained are shown in Table 1 below.

[0023]
Example 2
In Example 1, an acrylic rubber sheet was prepared using 5 parts by weight of the following as a fluorinated phosphonate, and the peeling force between the sheet and the metal plate was measured. The result as shown in the following Table 2 was obtained. Obtained.

[0024]
Example 3
In Example 1, an acrylic rubber sheet was prepared using the acrylic elastomer composition having the following compounding formulas BF, and the peeling force between the acrylic rubber sheet and the metal plate was measured.

[0025]
Note) Anti-aging agent CD: Ouchi Emerging Chemicals product Nocrack CD; 4,4'-bis (α, α-dimethylbenzyl) diphenylamine vulcanizing agent TCY: Sankyo Kasei product Zisnet F; trithiol-s-triazine vulcanization acceleration Agent BZ: Ouchi Emerging Chemicals Noxeller BZ; Zinc Dibutyldithiocarbamate Vulcanizing Agent AB: Ouchi Emerging Chemicals Balnoc AB; Ammonium Benzoate Vulcanization Accelerator D: Ouchi Emerging Chemicals Noxeller D; 1,3 -Diphenylguanidine co-crosslinking agent PM: Ouchi Emerging Chemicals product Balnock PM; N, N'-m-phenylenebismaleimide vulcanizing agent F40: Nippon Oil & Fats product Peroximon F40; α, α'-bis (tert-butylperoxy-m -Isopropyl) benzene
Comparative Example 1
In Example 1, an acrylic rubber sheet was prepared using 5 parts by weight of the following compound in place of the fluorinated phosphonate, and the peeling force between the acrylic rubber sheet and the metal plate was measured. As shown in Table 3 below, Results were obtained.

[0027]
Comparative Example 2
In Formulation F of Example 3, the fixing power was 12.0 kg without blending the fluorinated phosphonate.

Claims (2)

100 parts by weight of an acrylic elastomer, a fluorinated phosphonic acid represented by the general formula RfRnPO (OH) ₂ [where Rf is a polyfluorocarbon group or a perfluoropolyether group, R is an alkylene group having 1 to 6 carbon atoms, a phenylene group, a oxyphenylene group or a sulfonamido ethylene group, n represents 0 or 1 and is] salt was 0.1 to 20 wt parts blend of acrylic elastomer composition vulcanized molded acrylic elastomer vulcanization Goods. The acrylic elastomer vulcanized molded article according to claim 1, wherein an acrylic elastomer in which up to 95 parts by weight of the acrylic elastomer is replaced by an elastomer blendable with the acrylic elastomer is used.