JP2020070326A - Uncrosslinked fluororubber composition and rubber product produced using the same - Google Patents

Abstract

To provide an uncrosslinked fluororubber composition excellent in crush resistance, and a rubber product produced using the fluororubber composition.SOLUTION: The uncrosslinked fluororubber composition of the present disclosure contains a fluororubber as a rubber component and contains a phenolic resin. The rubber product of the present disclosure is formed of a rubber composition constituted by crosslinking the rubber component in the uncrosslinked fluororubber composition of the present disclosure. The rubber product may be a seal material.SELECTED DRAWING: None

Description

  The present disclosure relates to an uncrosslinked fluororubber composition and a rubber product produced using the same.

  Fluorine rubber, which has excellent chemical resistance and heat resistance, is used as a material for a sealing material in semiconductor manufacturing equipment (for example, Patent Document 1).

JP, 2005-127358, A

  A sealing material such as an O-ring that is attached to a semiconductor manufacturing apparatus may be largely compressed, and the sealing material may be crushed. In such a case, the apparatus must be stopped and the sealing material must be replaced, and there are problems such as damage to the apparatus and cleaning required.

  From this, an object of the technique of the present disclosure is to provide an uncrosslinked fluororubber composition excellent in crush resistance and a rubber product manufactured using the uncrosslinked fluororubber composition.

  The uncrosslinked fluororubber composition of the present disclosure contains fluororubber as a rubber component and also contains a phenol resin.

  The rubber product of the present disclosure is formed of a rubber composition in which the rubber component in the uncrosslinked fluororubber composition of the present disclosure is crosslinked. The rubber product may be a sealing material.

  By using the uncrosslinked fluororubber composition and the rubber product of the present disclosure, excellent crush resistance can be realized.

  Hereinafter, embodiments of the present disclosure will be described.

  The uncrosslinked fluororubber composition according to the embodiment contains fluororubber as a rubber component and a phenol resin, and may further contain a crosslinking agent and a crosslinking aid. The uncrosslinked fluororubber composition according to the embodiment is suitably used for manufacturing a rubber product, for example, a sealing material such as an O-ring used in a semiconductor processing apparatus that uses plasma such as a semiconductor etching apparatus or a plasma CVD apparatus. Be done.

  According to the uncrosslinked fluororubber composition according to the embodiment, by containing the phenolic resin, a fluororubber molded article (rubber product) having excellent crush resistance is obtained when it is crosslinked and molded.

  Examples of the fluororubber include a copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) (binary FKM), vinylidene fluoride (VDF), hexafluoropropylene (HFP) and tetrafluoroethylene ( TFE) copolymer (ternary FKM), tetrafluoroethylene (TFE) and propylene (Pr) copolymer (FEP), vinylidene fluoride (VDF), propylene (Pr) and tetrafluoroethylene ( TFE) copolymer, ethylene (E) and tetrafluoroethylene (TFE) copolymer (ETFE), ethylene (E) and tetrafluoroethylene (TFE) and perfluoromethyl vinyl ether (PMVE) Polymers, vinylidene fluoride (VDF) and tetrafluoroe Copolymer of ren (TFE) and perfluoromethyl vinyl ether (PMVE), Copolymer of vinylidene fluoride (VDF) and perfluoromethyl vinyl ether (PMVE), Tetrafluoroethylene (TFE) and perfluoroalkyl ether ( PFAE) copolymers and the like. It is preferable to use one or more of these. From the viewpoint of obtaining excellent physical properties, it is preferable to use a binary fluororubber.

  Examples of the phenol resin contained in the uncrosslinked fluororubber composition of the embodiment include novolac type phenol resin and resol type phenol resin.

  The content of the phenol resin is preferably 1 part by mass or more, more preferably 5 parts by mass or more, with respect to 100 parts by mass of the rubber component of the uncrosslinked fluororubber composition, from the viewpoint of obtaining excellent physical properties, and 50 It is good to set it as a mass part or less, more preferably 20 mass parts or less.

  The phenol resin is preferably a phenol resin which has been reacted. In other words, it is preferable to use a phenol resin in which the functional group does not substantially remain and the reaction is difficult.

  From the viewpoint of facilitating kneading with the rubber component, the phenol resin is preferably in powder form. The average particle size of the powdery phenol resin is preferably 2 μm or more, more preferably 5 μm or more, and preferably 30 μm or less, more preferably 20 μm or less.

  Next, an organic peroxide or a polyol can be used as the crosslinking agent. In the uncrosslinked fluororubber composition of the present embodiment, it is desirable to use an organic peroxide from the viewpoint of obtaining desired physical properties.

  The organic peroxide is a thermal cross-linking agent that cross-links the rubber component when heated to a predetermined temperature. Examples of the organic peroxide include 1,1-bis (t-butylperoxy) -3,5,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide and di-t-. Butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, α, α-bis (t-butylperoxy) -p-diisopropylbenzene, 2,5-dimethyl-2,5-di (t-butylperoxide) (Oxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne-3, benzoyl peroxide, t-butylperoxybenzene, t-butylperoxymaleic acid, t-butylper Examples thereof include oxyisopropyl carbonate and t-butyl peroxybenzoate. As the organic peroxide, it is preferable to use one or more of these, and from the viewpoint of obtaining excellent physical properties, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane is used. It is more preferable to use.

  Bisphenols are preferable as the polyol crosslinking agent. Specifically, for example, 2,2-bis (4-hydroxyphenyl) propane [bisphenol A], 2,2-bis (4-hydroxyphenyl) perfluoropropane [bisphenol AF], bis (4-hydroxyphenyl) Polyhydroxy aromatics such as sulfone [bisphenol S], bisphenol A-bis (diphenyl phosphate), 4,4′-dihydroxydiphenyl, 4,4′-dihydroxydiphenylmethane, and 2,2-bis (4-hydroxyphenyl) butane Compounds. From the viewpoint of obtaining excellent physical properties, the polyol is preferably bisphenol A, bisphenol AF, or the like. These may be in the form of alkali metal salts or alkaline earth metal salts.

  From the viewpoint of obtaining excellent physical properties, the content (A) of the cross-linking agent is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and 5 parts by mass with respect to 100 parts by mass of the rubber component. Hereafter, it is more preferable that the amount is 3 parts by mass or less.

  The cross-linking aid is a compound that is bonded so as to intervene between the molecules of the rubber component when the rubber component is cross-linked by the cross-linking agent. Examples of the cross-linking aid include triallyl cyanurate, trimethallyl isocyanurate, triallyl isocyanurate, triacryl formal, triallyl trimellitate, N, N′-m-phenylene bismaleimide, dipropargyl terephthalate, diallyl. Phthalate, tetraallyl terephthalate amide, triallyl phosphate, bismaleimide, fluorinated triallyl isocyanurate (1,3,5-tris (2,3,3-trifluoro-2-propenyl) -1,3,5-triazine -2,4,6-trione), tris (diallylamine) -S-triazine, triallyl phosphite, N, N-diallylacrylamide, 1,6-divinyldodecafluorohexane, hexaallylphosphoramide, N, N, N ', N'-tetraallyl lid Amide, N, N, N ', N'-tetraallyl malonamide, trivinyl isocyanurate, 2,4,6-trivinylmethyltrisiloxane, tri (5-norbornene-2-methylene) cyanurate, triallyl phosphite Etc. As the crosslinking aid, it is preferable to use one or more of these, and it is more preferable to use triallyl isocyanurate from the viewpoint of obtaining excellent physical properties.

  The content (B) of the crosslinking aid is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and 10 parts by mass or less with respect to 100 parts by mass of the rubber component from the viewpoint of obtaining excellent physical properties. , And more preferably 6 parts by mass or less.

  The content (B) of the crosslinking aid is preferably higher than the content (A) of the crosslinking agent from the viewpoint of obtaining excellent physical properties. The ratio (B / A) of the content (B) of the crosslinking aid to the content (A) of the crosslinking agent is preferably 1. from the viewpoint of allowing the crosslinking aid to react without excess and deficiency and obtaining excellent physical properties. It is preferably 0 or more, more preferably 2.0 or more, and preferably 4.0 or less, more preferably 3.0 or less.

  Further, the uncrosslinked fluororubber composition of the embodiment may contain silica. By containing silica, when crosslinked and molded, a fluororubber molded product having further excellent crush resistance is obtained. The silica is preferably synthetic amorphous silica such as dry silica or wet silica, more preferably dry silica such as hydrophilic dry silica or hydrophobic dry silica, and even more preferably hydrophobic dry silica.

  Further, the content of silica is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and more preferably 5 parts by mass with respect to 100 parts by mass of the rubber component, from the viewpoint of obtaining excellent physical properties including crush resistance. Is 30 parts by mass or less, more preferably 20 parts by mass or less.

  The silica may be surface-treated. For example, it may be surface-treated with a silane coupling agent to introduce a methyl group, a dimethyl group, a trimethyl group or the like.

  Further, it is desirable that the silica be in powder form. Further, the average particle size is preferably 5 μm or more, more preferably 10 μm or more, and preferably 50 μm or less, more preferably 30 μm or less.

  The uncrosslinked rubber composition according to the embodiment may further contain a hydrogen site protective agent. The hydrogen site protective agent is a compound that is bonded to a carbon radical generated by cleavage of the carbon-hydrogen bond of the rubber component when irradiated with radiation during the production of a rubber product.

  The hydrogen site protecting agent is a compound having a perfluoro skeleton having an alkenyl group bonded to the carbon radical of the rubber component in the molecule, and / or a siloxane skeleton having an alkenyl group bonded to the carbon radical of the rubber component in the molecule. It is preferable to include the compound of Examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group and a heptenyl group. Of these, the vinyl group is preferable as the alkenyl group.

  Examples of the compound having a perfluoro skeleton having an alkenyl group in the molecule include a compound having a perfluoropolyether structure and a compound having a perfluoroalkylene structure. Examples of the siloxane skeleton compound having an alkenyl group in the molecule include a polymer of methylvinylsiloxane, a polymer of dimethylsiloxane, a copolymer of dimethylsiloxane and methylvinylsiloxane, dimethylsiloxane, methylvinylsiloxane and methylphenyl. Examples thereof include copolymers with siloxane. In addition, an organopolysiloxane containing an alkenyl group in the molecule, which is a liquid silicone rubber of addition polymerization, may be mentioned. As the hydrogen site protecting agent, it is preferable to use one or more of these.

  The content of the hydrogen site protective agent is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and preferably 20 parts by mass with respect to 100 parts by mass of the rubber component, from the viewpoint of enhancing plasma resistance. Below, it is more preferably 15 parts by mass or less.

  Furthermore, the uncrosslinked rubber composition according to the embodiment may contain a reinforcing material such as carbon black, a plasticizer, a processing aid, a vulcanization accelerator, an antioxidant, etc. depending on the rubber product to be manufactured. .. However, when used in the production of a rubber product in which the generation of particles in a plasma atmosphere poses a problem, the content of carbon black is preferably 5 parts by mass with respect to 100 parts by mass of hydrogen-containing fluororubber. The amount is below, more preferably 3 parts by mass or less, and most preferably 0 part by mass.

  The uncrosslinked rubber composition according to the embodiment can be prepared using an open type rubber kneader such as an open roll or a closed type rubber kneader such as a kneader. Among these, particularly in an open type rubber kneader such as an open roll, excellent kneadability can be obtained.

  Next, a method for manufacturing a rubber product using the uncrosslinked rubber composition according to the embodiment will be described.

  In the method for manufacturing a rubber product, first, a predetermined amount of the uncrosslinked rubber composition according to the embodiment is filled in a cavity of a preheated mold, and then the mold is clamped, and in that state, a predetermined molding temperature and a predetermined molding temperature are set. Hold for a predetermined molding time at the molding pressure. At this time, the uncrosslinked rubber composition according to the embodiment is molded into the shape of the cavity, and the rubber component is crosslinked by the crosslinking agent to lose plasticity. This molding may be press molding or injection molding. The molding temperature is, for example, 150 ° C. or higher and 180 ° C. or lower. The molding pressure is, for example, 0.1 MPa or more and 25 MPa or less. The molding time is, for example, 3 minutes or more and 20 minutes or less. A rubber product can be obtained by opening the mold, taking out the molded product from the inside, and cooling it. The molded product taken out from the mold may be further subjected to heat treatment at a heating temperature of 150 ° C. or higher and 250 ° C. or lower and a heating time of 2 hours or longer and 6 hours or shorter.

(Kneading of uncrosslinked rubber composition and preparation of crosslinked rubber sheet)
In each of the following Examples 1 to 7 and Comparative Example 1, an uncrosslinked rubber composition was kneaded and a crosslinked rubber sheet was prepared using the same. Each configuration is also shown in Table 1.

<Example 1>
Using an 8-inch open roll, a binary fluororubber of a rubber component, to 100 parts by mass of this rubber component, 1.5 parts by mass of an organic peroxide as a cross-linking agent, 4 parts by mass of a crosslinking aid, powder Was added and kneaded to prepare an uncrosslinked rubber composition.

  Subsequently, this uncrosslinked rubber composition was press-molded at a molding temperature of 165 ° C., a molding pressure of 5 MPa, and a molding time of 15 minutes, and then heat-treated at a heating temperature of 200 ° C. and a heating time of 4 hours to obtain the sheet-shaped product of Example 1. A rubber composition of was obtained.

<Example 2>
When compared with Example 1, a sheet-shaped rubber composition of Example 2 was obtained in the same manner except that the phenol resin was 5 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 3>
When comparing Example 1, a sheet-shaped rubber composition of Example 3 was obtained in the same manner except that the phenol resin was 18 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 4>
A sheet-like rubber composition of Example 4 was obtained in the same manner as in Example 1 except that 10 parts by mass of silica was further added to 100 parts by mass of the rubber component and kneaded.

<Example 5>
When compared with Example 4, a sheet-shaped rubber composition of Example 5 was obtained in the same manner except that the phenol resin was 15 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 6>
When compared with Example 4, a sheet-shaped rubber composition of Example 6 was obtained in the same manner except that the phenol resin was 15 parts by mass and the silica was 15 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 7>
When compared with Example 4, a sheet-shaped rubber composition of Example 7 was obtained in the same manner as in Example 7, except that 10 parts by mass of hydrogen site protective agent was further added to 100 parts by mass of the rubber component and kneaded. ..

<Comparative Example 1>
When compared with Example 1, a sheet-shaped rubber composition of Comparative Example 1 was obtained in the same manner except that the phenol resin was not added.

(Test method)
<Tensile properties>
With respect to the crosslinked rubber sheets prepared in Examples 1 to 7 and Comparative Example 1, a tensile test was performed based on JISK6251 to measure tensile strength (Tb) and elongation at break (Eb).
<Crush resistance performance>
With respect to the crosslinked rubber sheets prepared in Examples 1 to 7 and Comparative Example 1, the crush resistance performance was measured using the apparatus and method used for determining compression set (JISK6262: 2013).

A test piece was prepared from each crosslinked rubber sheet and heat-treated at 150 ° C. for 24 hours. Then, in the apparatus and method for the room temperature test of JISK6262: 2013, the test piece is inserted between the compression plates and the holder is tightened to gradually increase the compression rate. Table 1 shows the compressibility when crushing occurs as pressure crushing performance. The larger this value is, the better the crush resistance performance is. Table 1 shows ◯ when the crush resistance was 50% or more (that is, the compression rate when crush occurred was 50% or more), and × when it was less than 50%. There is.
<Radical resistance>
The crosslinked rubber sheet of Example 7 containing the hydrogen site protective agent was exposed to radicals at an elongation rate of 10%, and the weight loss and the occurrence of cracks were examined. Further, with respect to the crosslinked rubber sheet of Comparative Example 1, the occurrence of cracks was similarly examined.

(Test results)
The test results are also shown in Table 1.

  The crush resistance is 43% in Comparative Example 1 in which the rubber composition does not contain the phenol resin and silica, whereas it is 50% or more in Examples 1 to 7. More specifically, it is 55%, 52% and 61% with respect to Examples 1, 2 and 3 in which 10 parts by mass, 5 parts by mass and 18 parts by mass of the phenolic resin were sequentially mixed with 100 parts by mass of the rubber component. Therefore, the higher the content of the phenol resin, the higher the crush resistance performance. In addition, with respect to Examples 4, 5 and 6 in which silica was further contained together with the phenol resin, the crush resistance performance was 70%, 71% and 75%, respectively, which was further improved. In Example 7, which is a mixture of Example 4 and further containing a hydrogen site protective agent, the crush resistance performance is 71%, which is almost the same as in Example 4.

  It was also confirmed that the radical resistance performance can be improved also in the rubber composition of the present disclosure containing a phenol resin and silica by adding a hydrogen site protective agent.

  The tensile strength (Tb) of Examples 1 to 3 containing the phenol resin is about the same as that of Comparative Example 1. In Examples 4 to 7 in which silica was contained together with the phenol resin, the value was about 20 to 30% larger than that in Comparative Example.

  The elongation (Eb) in each of the examples is smaller than that of the comparative example. In particular, the elongation tends to decrease as the total amount of the phenol resin, silica, and hydrogen site protective agent compounded increases.

  Although such tendencies are observed in the tensile strength and the elongation, it is within the practical range in any of Examples 1 to 7.

  The technique of the present disclosure is useful in the technical field of uncrosslinked fluororubber compositions and rubber products produced using the same.

Claims (12)

  An uncrosslinked fluororubber composition comprising a fluororesin as a rubber component and a phenol resin. In claim 1,
The uncrosslinked fluororubber composition is characterized in that the compounding amount of the phenol resin with respect to 100 parts by mass of the rubber component is 5 parts by mass or more and 20 parts by mass or less. In claim 1 or 2,
An uncrosslinked fluororubber composition further comprising 5 parts by mass or more and 20 parts by mass or less of silica based on 100 parts by mass of the rubber component. In claim 3,
The silica is a powder having an average particle size of 10 μm or more and 30 μm or less, which is an uncrosslinked fluororubber composition. In Claim 3 or 4,
The silica is a surface-treated uncrosslinked fluororubber composition. In any one of Claims 1-5,
The uncrosslinked fluororubber composition, wherein the phenolic resin is a phenolic resin that has completed the reaction. In any one of Claims 1-6,
The uncrosslinked fluororubber composition, wherein the phenolic resin is in powder form. In claim 7,
An uncrosslinked fluororubber composition, wherein the phenol resin has an average particle size of 5 μm or more and 20 μm or less. In any one of Claims 1-8,
An uncrosslinked fluororubber composition, further comprising a hydrogen site protective agent. In claim 9,
The uncrosslinked fluororubber composition, wherein the blending amount of the hydrogen site protective agent with respect to 100 parts by mass of the rubber component is 5 parts by mass or more and 15 parts by mass or less.   A rubber product formed by a rubber composition in which the rubber component in the uncrosslinked fluororubber composition according to any one of claims 1 to 10 is crosslinked. In claim 11,
A rubber product, wherein the rubber product is a sealing material.