JP2003055577A - Modified inorganic filler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded product of a fluorine-containing elastomer capable of withstanding the use at a high temperature of >=230 deg.C. SOLUTION: A modified inorganic filler is an inorganic filler (except a carbon filler) having <=0.5 μm primary average particle diameter and is obtained by subjecting the inorganic filler to a treatment for reducing the surface activity thereof. A fluorine-containing elastomer composition for crosslinking comprises the fluorine-containing elastomer having crosslinkable groups and a crosslinking agent and/or a crosslinking promoter.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a good sealing property and 23 while maintaining processability (rubber kneading property) and crosslinkability.
The present invention relates to a fluorine-containing elastomer composition for crosslinking that gives a fluorine-containing elastomer molded product that can withstand use at a high temperature exceeding 0 ° C., and a modified inorganic filler used therein.

[0002]

2. Description of the Related Art In the field of semiconductor manufacturing, it is one of the most important problems to avoid mixing of foreign matter in the form of fine particles called particles in the manufacturing process. This problem is also required for sealing materials such as O-rings used for sealing semiconductor manufacturing equipment. Therefore, when using ultrafine particles (primary average particle diameter 0.005 to 0.05 μm) as the filler compounded in the elastomer molded product that constitutes the sealing material, even if a treatment such as plasma irradiation is used, the filler can be removed from the outside. Even if it scatters on the surface of the semiconductor, it will be smaller than the distance between lines (usually 0.2 μm or more) of the fine pattern formed on the semiconductor and will not cause a connection by filling the space between lines. .

Further, in the field of semiconductor manufacturing equipment, plasma resistance (a property that weight reduction and generation of particles are small under a plasma irradiation environment) is favorable, so that aluminum oxide filler or dioxide is used rather than carbon black which is commonly used. Titanium fillers have begun to be used (for example, WO01 / 32782 pamphlet).

Apart from the above points, recently, processing equipment at a high temperature of 230 to 300 ° C. has been required for an apparatus used for semiconductor manufacturing. As an elastomer molded article that gives such heat resistance at high temperatures, a crosslinking elastomer composition containing an inorganic filler such as a metal oxide treated with a silane-based compound has been proposed (JP 2000-
290454). However, this publication makes no mention of the importance of the inorganic filler and its use.

Further, Japanese Patent Publication No. 2000-502122 proposes a composition containing titanium dioxide as a filler, but there is no description about the particle size of the filler used.

Further, WO 01/32782 pamphlet describes fine particles (primary average particle size 0.005 to 0.
Although a cross-linking elastomer composition containing an inorganic filler (about 05 μm) is described, the properties at 230 ° C. or higher have not been evaluated.

Generally, in a cross-linking elastomer composition, the smaller the particle size of the inorganic filler to be blended, the stronger the surface activity thereof, and the deterioration of the elastomer when used at high temperature. Therefore, WO01 /
In the elastomer composition for cross-linking described in the No. 32782 pamphlet, the elastomer begins to deteriorate in a high temperature environment of 230 ° C. or higher, the compression set increases, and the sealing ability decreases (Comparative Examples 1 and 2 described later).
reference).

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to an inorganic filler (excluding carbon filler) which can withstand use in a high temperature environment of 230 ° C. or higher and does not cause particles, and a crosslinking elastomer composition containing the same. And an elastomer molded article.

[0009]

The present invention provides an inorganic filler (excluding carbon filler) having a primary average particle diameter of 0.5 μm or less, further 0.05 μm or less,
The present invention relates to a modified inorganic filler that has been treated to reduce its surface activity.

Examples of the surface activity reduction treatment include fluorination treatment in which an inorganic filler is brought into contact with a fluorine compound.

As the inorganic filler as a raw material, inorganic fillers other than carbon black, particularly metal oxide fillers, and aluminum oxide fillers are suitable.

Among the modified inorganic fillers, in oxygen plasma irradiation and NF ₃ plasma irradiation carried out under the following condition (1), the weight reduction or increase before and after each plasma irradiation is 1% or less, particularly 0.1%. Those below and below 20%, especially below 2%, more preferably below 1% are preferable. Flow rate: 16 sccm Pressure: 20 mTorr RF power: 800 W Irradiation time: 30 minutes Frequency: 13.56 MHz

The modified inorganic filler of the present invention is particularly useful when incorporated into an elastomer composition for crosslinking, particularly an elastomer composition for producing a sealing material for semiconductor manufacturing equipment.

The present invention also provides a fluorine-containing elastomer composition for crosslinking, which comprises the modified inorganic filler, a fluorine-containing elastomer having a crosslinkable group (hereinafter referred to as "crosslinkable elastomer"), and a crosslinking agent and / or a crosslinking accelerator. Regarding

The crosslinkable fluorine-containing elastomer is preferably a perfluoroelastomer having a crosslinkable group, and the crosslinkable group of the fluorine-containing elastomer having a crosslinkable group is preferably a CN group or a COOH group.

The cross-linking agent is represented by the formula (1):

[0017]

[Chemical 11]

(Wherein R ¹ is --SO _2- , --O--, --C
(= O)-,

[0019]

[Chemical 12]

The alkylidene group having 1 to 10 carbon atoms, a perfluoroalkylidene group or a single bond having 1 to 10 carbon atoms; X ¹ is _{-OH, -NH 2, -SH, -NHR} (R is 1 to 6 carbon atoms An optionally substituted linear or branched alkyl group) or -NHAr (Ar is an optionally substituted phenyl group or naphthyl group)), a compound represented by the formula (2):

[0021]

[Chemical 13]

(In the formula, R ² is a linear or branched alkylidene group which may be substituted, an arylene group which may be substituted,

[0023]

[Chemical 14]

(R ³ is --SO _2- , --O--, --C (= O)
-,

[0025]

[Chemical 15]

Or a compound represented by the formula (3):

[0027]

[Chemical 16]

[Wherein, m is an integer of 1 to 10], a compound of the formula (4):

[0029]

[Chemical 17]

(Wherein, X ² is the same or different and both are H or NH ₂ ; p is an integer of 1 to 10), and / or formula (5):

[0031]

[Chemical 18]

(Wherein, X ³ is the same or different, both are H or NH ₂ ; Y is the same or different, both are H or OH) Since it has excellent properties, it can be preferably used.

In particular, in the above formula (1), R ¹ is

[0034]

[Chemical 19]

And X ¹ is

[0036]

[Chemical 20]

A crosslinker that is is preferred.

An organic tin compound is preferably used as the crosslinking accelerator.

The present invention further relates to a crosslinked fluorine-containing elastomer molded article obtained by crosslinking the above fluorine-containing crosslinkable elastomer composition, particularly a molded article used for sealing a semiconductor manufacturing apparatus.

Furthermore, the present invention also relates to a semiconductor manufacturing apparatus in which the molded product is incorporated.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION The modified inorganic filler of the present invention has a primary average particle diameter of 0.5 μm or less, particularly 0.05 μm (5
The surface activity of the fine particle inorganic filler having a particle size of 0 nm or less is reduced. For molded articles such as sealing materials used in semiconductor manufacturing equipment, smaller ones are preferable from the viewpoint of particle reduction. The lower limit of the particle size is not particularly limited, but 0.005 μm (5n
m) or more.

Examples of the inorganic filler as a raw material include various inorganic fillers except carbon black. Since carbon black has a large weight loss with respect to O ₂ plasma and NF ₃ plasma, its use should be avoided in the field of plasma irradiation treatment, especially in the field of semiconductor manufacturing.

The following fillers may be mentioned as specific examples, but the fillers are not limited to these.

Metal oxide filler: titanium dioxide, silicon oxide, aluminum oxide, zinc oxide, etc. Sulfate filler: barium sulfate, aluminum sulfate, etc. Carbonate filler: barium carbonate, etc. Metal hydroxide filler: aluminum hydroxide, etc.

Of these, metal oxide fillers, particularly aluminum oxide, are preferable for use as a sealing material for semiconductor manufacturing equipment, in particular, because they have excellent resistance to high-density plasma irradiation.

Since these inorganic fillers are fine particles, their surface activity is higher than that of large particles. Examples of the surface activity that can be a problem include various catalytic activities and adsorption activities.

In the present invention, by reducing these surface activities, it is possible to suppress deterioration of the elastomer or the like as a matrix even when used at a high temperature of 230 ° C. or higher. Examples of the treatment for reducing the surface activity (the treatment for reducing the surface activity) include a method of bringing the fluorine compound into contact with the inorganic fine particle filler to perform the fluorination treatment.

The mechanism by which the surface activity of the filler is reduced when the inorganic fine particle filler is brought into contact with the fluorine compound is not clear, but because the fluorine compound fluorinates active sites on the filler surface, or the fluorine compound is thermally decomposed. It is presumed that the generated carbon is adsorbed on the active sites.

The conditions for this fluorination treatment may be appropriately selected depending on the type of fluorine compound used and the target inorganic filler. Further, the degree of fluorination may be determined in consideration of the type of the inorganic filler, the purpose of use, the processability of the elastomer composition, and the like, and the surface activity of the inorganic fine particle filler does not matter at a high temperature of 230 ° C. or higher. .
At a minimum, the surface active points of the inorganic fine particle filler may be blocked by fluorination, and the content of fluorine atoms in the modified inorganic filler after the fluorination treatment may be below the measurement limit. The effect of the fluorination treatment is that a molded product molded from the crosslinking air storm composition described below is 230
When exposed to a high temperature of 0 ° C. or higher, it can be clearly determined because deterioration does not occur as compared with the inorganic fine particle filler that is not fluorinated.

In some cases, even if the fluorination proceeds too much, another problem may occur. For example, in the case of an aluminum oxide filler, it should be noted that crosslinking may be hindered if fluorination proceeds too much.

The fluorine compound used may be an inorganic fluorine compound or an organic fluorine compound.

Examples of the inorganic fluorine compound include fluorine gas, hydrogen fluoride, sulfur fluoride (eg, sulfur tetrafluoride, sulfur hexafluoride, etc.), sulfuryl fluoride, thionyl fluoride, ammonium fluoride (eg, acidic fluoride). Ammonium fluoride, neutral ammonium fluoride, etc.).

Examples of the organic fluorine compound include fluorinated hydrocarbons, nitrogen-containing or oxygen-containing fluorinated hydrocarbons and the like.

The fluorinated hydrocarbon is, for example, a saturated or unsaturated hydrocarbon having 8 or less carbon atoms, preferably 4 or less carbon atoms, in which one or more hydrogen atoms are substituted with fluorine atoms. can give. Specific examples include, for example, CF ₄ , CHF ₃ , CF ₃ CF ₃ , CHF ₂ C.
Fluoroalkanes such as F ₃ and CHF ₂ CHF ₂ ; CF ₂
= CF ₂ (tetrafluoroethylene), CF ₃ CF = CF
Examples include fluoroalkanes such as ₂ (hexafluoropropylene). Among these, perfluoroalkanes such as CF ₄ and perfluoroalkenes such as hexafluoropropane (HFP) are preferable because the reaction easily occurs.

Examples of the nitrogen-containing or oxygen-containing fluorinated hydrocarbon include those represented by the formula (1): C _n F _a H _b X (1) (wherein, X is an oxygen atom or a nitrogen atom, n is 1 to 8, particularly An integer of 1 to 4, a is an integer of 1 to 2n + m, and b is 0 to 2
Examples thereof include compounds represented by n + m-1 (provided that m is 2 when X is an oxygen atom, and 3 when X is a nitrogen atom). Specific examples include hexafluoroacetone, hexafluoro-1,2-epoxyethane, decafluoroether, tri (trifluoromethyl) amine, tetrafluoroethylmethyl ether, and the like.

Although not limited thereto, a treatment method for obtaining a fluorinated aluminum oxide filler which is particularly preferable for use as a sealing material for semiconductor manufacturing equipment will be illustrated.

When hydrogen fluoride or ammonium fluoride is used as the fluorine compound, the aluminum oxide fine particles may be brought into contact with the fluorine compound at 20 to 450 ° C.

When sulfur fluoride, furfuryl fluoride or thionyl fluoride is used as the fluorine compound, a contact temperature of 300 to 500 ° C. is adopted.

When an organic fluorine compound such as HFP is used, the temperature is 100 to 600 ° C., preferably 150 to 450.
It may be brought into contact with the aluminum oxide fine particles at ℃.

Other surface activity reducing treatment methods include, for example, a method of bringing an inorganic filler into contact with a hydrocarbon compound at a temperature of 150 to 600 ° C., a method of surface treating the inorganic filler with a silane coupling agent or the like. . However, the method of surface treatment with a silane coupling agent is used in the field of semiconductor manufacturing equipment that requires a high degree of cleanliness, because outgas generated from the silane coupling agent is generated when used at high temperatures or in a plasma irradiation atmosphere. Is not suitable for use.

As described above, the modified inorganic filler of the present invention thus obtained has a small weight change due to oxygen plasma irradiation and NF ₃ plasma irradiation, and is excellent in plasma resistance.

The present invention also relates to the modified inorganic filler of the present invention.
The present invention relates to a cross-linking elastomer composition comprising (A), a cross-linkable fluorine-containing elastomer (B), a cross-linking agent (C) and / or a cross-linking accelerator (D).

The compounding amount of the modified inorganic filler (A) is 1 with respect to 100 parts by weight of the crosslinkable fluorine-containing elastomer (B).
˜150 parts by weight, preferably 1 to 50 parts by weight. If the amount is too small, the effect of adding the inorganic filler is not exerted, and if the amount is too large, the sealing property of the molded product deteriorates and the hardness also increases.

Examples of the crosslinkable group of the fluorine-containing elastomer (B) include a carboxyl (COOH) group, an alkoxycarbonyl (COOR) group, a nitrile (CN) group, an iodine atom or a bromine atom. A COOH group, a COOR group or a CN group capable of taking a hydrogen atom is preferable, and particularly a COO that gives a crosslinked structure excellent in heat resistance.
H or CN groups are preferred.

Specific examples of the fluorine-containing elastomer include
Formula ^{(I): X 1 - [} A- (Y) p] q -X 2 (I) or formula ^{(II): X 1 - [} A- (Y 1) p] q - [B- (Y 2) _r ] _s -X ² (II) (In the formula, X ¹ and X ² can be arbitrarily changed by changing an initiator or a chain transfer agent at the time of polymerization, or by modifying an end group. Although they are not the same, they are, for example, the same or different and each is a carboxyl group, an alkoxycarbonyl group, a nitrile group, an iodine atom, a bromine atom, or a sulfonic acid group.
Y, Y ¹ and Y ² are the same or different and each is a divalent organic group having a carboxyl group, an alkoxycarbonyl group or a nitrile group in the side chain, A is an elastomeric fluorine-containing polymer chain segment (hereinafter referred to as “elastomer Segment A "), B is a non-elastomeric fluoropolymer chain segment (hereinafter referred to as" non-elastomeric segment B "), p is an integer of 0 to 50, and q is 1 to 5.
Is an integer of 0 to 10 and s is an integer of 1 to 3, provided that any one of X ¹ , X ² , Y, Y ¹ or Y ² is a nitrile group, a carboxyl group or an alkoxycarbonyl group. And Y, Y ¹ and Y ² may be randomly contained in the segment of A or B) and has a carboxyl group, a nitrile group and / or an alkoxycarbonyl group as a crosslinking site at the end of the main chain and A crosslinkable fluorine-containing elastomer having a branched chain is preferred.

Examples of the elastomeric segment A include those represented by the formula (III):

[0067]

[Chemical 21]

(In the formula, m / n = 95 to 50/5 to 50
(Mol%) and R _f is a binary copolymer rubber represented by a fluoropolyoxyalkyl group having 1 to 20 carbon atoms or a perfluoroalkyl group having 1 to 8 carbon atoms, or a compound represented by the formula (I
V):

[0069]

[Chemical formula 22]

(In the formula, 1 / m / n = 95 to 35/0 to 3
Perfluoroelastomer such as terpolymer rubber represented by 0/5 to 35 (mol%), R _f is a fluoropolyoxyalkyl group having 1 to 20 carbon atoms or a perfluoroalkyl group having 1 to 8 carbon atoms) Segment or expression (V):

[0071]

[Chemical formula 23]

(In the formula, m / n = 85-60 / 15-40
(Mol%)), a binary copolymer rubber represented by the formula (VI):

[0073]

[Chemical formula 24]

(Wherein 1 / m / n = 85-20 / 0-4
0/15 to 40 (mol%)), a terpolymer rubber represented by the formula (VII):

[0075]

[Chemical 25]

(In the formula, 1 / m / n = 95 to 45 / 0-1
0/5 to 45 (mol%), Z ¹ , Z ² and Z ³ are each independently a fluorine atom or a hydrogen atom, and R _f is a carbon atom of 1
~ 20 fluoropolyoxyalkyl groups or 1 carbon atoms
~ 8 perfluoroalkyl group) terpolymer rubber, or

[0077]

[Chemical formula 26]

(L / m / n = 1-80 / 0-80 / 10
˜50 (mol%), R _f is the same as above), and the like.

Further, as Y, Y ¹ and Y ² for introducing a cross-linking point into the branched chain, for example,

[0080]

[Chemical 27]

Examples thereof include nitrile group-containing monomers, carboxyl group-containing monomers, alkoxycarbonyl group-containing monomers and the like. Usually, nitrile group-containing monomers and carboxyl group-containing monomers are preferable. Is.

As the non-elastomeric segment B,
Basically, it is not limited as long as it contains a fluorine atom and does not have the above-mentioned elastomeric property. It is a property to be obtained by block-copolymerizing the non-elastomeric segment B.
It may be selected according to the function. Among them, a crystalline polymer chain segment having a crystalline melting point of 150 ° C. or higher is preferable in order to impart mechanical properties.

Among the monomers which can form the non-elastomeric segment B, the fluorine-containing monomer is, for example, TF.
E, chlorotrifluoroethylene (CTFE), perfluoro (alkyl vinyl ether) (PAVE), hexafluoropropylene (HFP), CF ₂ ═CF (C
F ₂ ) _p X (p is an integer of 1 to 10, X is F or Cl),
Perhaloolefins such as perfluoro-2-butene; vinylidene fluoride, vinyl fluoride, trifluoroethylene,

[0084]

[Chemical 28]

(X ⁵ and X ⁶ are H or F, q is 1 to 1
One integer or two or more kinds of partially fluorinated olefins such as CH ₂ ═C (CF ₃ ) _{2 and the} like. Further, a monomer copolymerizable with these, for example, ethylene,
One or more of propylene, vinyl chloride, vinyl ethers, carboxylic acid vinyl esters, and acrylics can be used as a copolymerization component.

Of these, from the viewpoint of chemical resistance and heat resistance, the monomer used as the main component is a fluorine-containing olefin alone or a combination of fluorine-containing olefins, a combination of ethylene and TFE, a combination of ethylene and CTFE. Particularly preferred are perhaloolefins alone or combinations of perhaloolefins.

Specifically, (1) VdF / TFE (0-100 / 100-0), especially VdF / TFE (70-99 / 30-1), PTFE
Or PVdF; (2) ethylene / TFE / HFP (6 to 60/40 to 8)
1/1 to 30), 3,3,3-trifluoropropylene-1,2-trifluoromethyl-3,3,3-trifluoropropylene-1 / PAVE (40 to 60/60 to 4)
0); (3) TFE / CF ₂ = CF-R _f ³ (composition range showing non-elastomeric property, that is, CF ₂ = CF-R _f ³ is 15).
Mol% or less. R _f ³ is a linear or branched fluoro- or perfluoroalkyl group which may have one or more ether type oxygen atoms, or a fluoro- or perfluorooxyalkyl group. ); (4) VdF / TFE / CTFE (50-99 / 30-
0/20 to 1); (5) VdF / TFE / HFP (60 to 99/30 to 0)
/ 10 to 1); (6) Ethylene / TFE (30 to 60/70 to 40); (7) Polychlorotrifluoroethylene (PCTF
E); (8) Ethylene / CTFE (30-60 / 70-40)
And so on. In the parentheses, mol% is shown. Among them, PTFE is especially preferable from the viewpoint of chemical resistance and heat resistance.
And _{TFE / CF 2 = CF-R} f 3 (R f 3 is as defined above) nonelastomeric copolymer is preferred.

As the monomer capable of forming the non-elastomeric segment B, 5 mol% or less, preferably 2 mol% or less, of the unit Y ² which gives the above-mentioned curing site for various crosslinking may be introduced. .

The block copolymerization of the non-elastomeric segment B can be carried out, for example, by emulsion-polymerizing the elastomeric segment A and then changing the monomer for the non-elastomeric segment B.

The average molecular weight of the non-elastomeric segment B can be adjusted within a wide range of 1,000 to 1,200,000, preferably 3,000 to 400,000.

Further, by making 90 mol% or more, especially 95 mol% or more of the constitutional units of the elastomeric segment A a perhaloolefin unit, it is possible to surely block-copolymerize the non-elastomeric segment B with the elastomeric segment A, Moreover, the molecular weight (degree of polymerization) of the non-elastomeric segment B can be increased.

The terminal groups X ¹ and X ² of the elastomer are not particularly limited as described above, but are preferably a carboxyl group, an alkoxycarbonyl group or a nitrile group. As a method for introducing a carboxyl group into the terminal group, Examples include the acid treatment method described below.

The fluorine-containing elastomer can be produced by a polymerization method such as an emulsion polymerization method, a suspension polymerization method or a solution polymerization method.

The polymerization initiator is preferably a carboxyl group or a group capable of forming a carboxyl group (eg, acid fluoride, acid chloride, CF ₂ OH, all of which generate a carboxyl group in the presence of water) at the end of the elastomer. Those that can be present in are used. Specific examples include ammonium persulfate (APS) and potassium persulfate (KPS).

A chain transfer agent usually used for adjusting the molecular weight may be used, but it is preferably not used as much as possible because the proportion of the group capable of forming a carboxyl group introduced at the terminal decreases. However, the chain transfer agent is not limited to this as long as the group can exist at the terminal of the elastomer. If no chain transfer agent is used, the molecular weight is such that the polymerization is carried out at low pressure, eg below 2 MPa · G, preferably 1M.
It may be adjusted by carrying out at Pa · G or less. Other polymerization conditions are not particularly limited, but in order to obtain a polymerization product having a carboxyl group at the terminal and / or the branched chain without undergoing the acid treatment described below, the pH of the polymerization system is set to a strong acid of 3 or less. Preferably.

Although some of the thus obtained polymerization products do not contain a free carboxyl group depending on the polymerization conditions, they can be converted into a free carboxyl group by the following acid treatment. .

The fluorine-containing elastomer used in the present invention is
By subjecting the polymerization product to an acid treatment, it is preferable to convert a group such as a metal salt or an ammonium salt of a carboxylic acid present in the polymerization product into a carboxyl group. As the acid treatment method, for example, washing with hydrochloric acid, sulfuric acid, nitric acid or the like, or a method of adjusting the pH of the mixture system after the polymerization reaction to 3 or less with these acids is suitable.

This acid treatment is preferably applied as a coagulation means when the polymerization product is isolated from the polymerization reaction mixture by coagulation, from the viewpoint of simplifying the process. Alternatively, the polymerization mixture may be treated with an acid and then the polymerization product may be isolated by a means such as freeze-drying. Furthermore, a method such as coagulation by ultrasonic waves or coagulation by mechanical force can be adopted.

It is also possible to introduce a carboxyl group by oxidizing a fluorine-containing elastomer containing iodine or bromine with fuming sulfuric acid.

When the crosslinkable group introduced into the fluorine-containing elastomer (B) is a COOH group or a CN group, the amount of the crosslinkable group is 0.1 mol% or more from the viewpoint of making the crosslink density proper,
Preferably 0.3-5 mol%, more preferably 0.3
~ 3 mol%.

The fluorine-containing elastomer of the present invention can be crosslinked by a crosslinking method that does not use a crosslinking agent, for example, a high energy ray irradiation method such as an electron beam irradiation method, a radiation irradiation method, or an ultraviolet irradiation method. From the viewpoint of improving the heat resistance of the product, a crosslinking agent capable of reacting with a crosslinking group such as a CN group or a COOH group is added.

COOH group or CN group, and further COO
Specific cross-linking agents capable of reacting with the R group include those represented by formulas (1) to
The cross-linking agent described above as (5) is preferred.

Specific examples of the crosslinking agent of the formula (1) include, for example, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (general name: bis (aminophenol) AF), 2,2. -Bis (3-amino-4-mercaptophenyl) hexafluoropropane, tetraaminobenzene, bis-3,4-diaminophenylmethane, bis-3,4-diaminophenyl ether, 2,2
-Bis (3,4-diaminophenyl) hexafluoropropane, 2,2-bis [3-amino-4 (N-methylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4 (N -Phenylamino) phenyl]
Hexafluoropropane 2,2-bis [3-amino-4
Examples thereof include (N-methylamino) phenyl] hexafluoropropane and 2,2-bis [3-amino-4 (N-phenylamino) phenyl] hexafluoropropane.

Specific examples of the crosslinking agent of the formula (2) include, for example, 2,2-bis [N- (2-aminophenyl)-(3
-Aminophenyl)] hexafluoropropane, 2,2
-Bis [N- (2-aminophenyl)-(4-aminophenyl)] hexafluoropropane and the like.

Specific examples of the cross-linking agent of the formula (3) are, for example,

[0106]

[Chemical 29]

And the like.

Specific examples of the cross-linking agent of the formula (4) include perfluoroadipic acid bisamidrazone, perfluorosuberic acid bisamidrazone and the like.

Specific examples of the cross-linking agent of the formula (5) are, for example,

[0110]

[Chemical 30]

And the like.

Of these, the crosslinking agents of the formulas (1) and (2), especially 2,2-bis [3-amino-4 (N-phenylamino) from the viewpoint of improving the heat resistance and chemical resistance of the molded article. ) Phenyl] hexafluoropropane, 2,2-bis [N- (2-aminophenyl)-(3-aminophenyl)] hexafluoropropane, 2,2-bis [N-
(2-Aminophenyl)-(4-aminophenyl)] hexafluoropropane is preferred.

The compounding amount of the crosslinking agent (C) is preferably 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the elastomer.

If necessary, instead of the cross-linking agent (C),
Alternatively, a crosslinking accelerator (D) may be added. Examples of the crosslinking accelerator (D) include organotin compounds and 15
Examples thereof include organic and / or inorganic ammonium salts that generate ammonia gas at 0 to 200 ° C., and organic tin compounds are particularly preferable in terms of providing a crosslinked structure having heat resistance.

The amount of the crosslinking accelerator compounded is preferably 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the elastomer.

In addition to the above, a triazine cross-linking system using triallyl isocyanurates, a peroxide cross-linking system, a polyol cross-linking system and the like can be adopted as the cross-linking system. Among them, fluorinated triallyl isocyanurate (US Pat. No. 4,320,216, etc.) obtained by substituting hydrogen atoms in the three allyl groups of triallyl isocyanurate with fluorine atoms is preferable from the viewpoint of giving a molded article excellent in heat resistance.

In the composition of the present invention, if necessary, usual additives which are compounded in the fluorine-containing elastomer composition for crosslinking, such as fillers, processing aids, plasticizers, colorants and the like can be compounded. One or more conventional crosslinking agents or crosslinking accelerators different from the above may be blended. Further, known fluororubbers may be mixed as long as the effects of the present invention are not impaired.

The composition of the present invention can be prepared by mixing the above components using a usual rubber processing machine such as an open roll, a Banbury mixer or a kneader. In addition, it can be prepared by a method using a closed mixer or a method of co-coagulating from emulsion mixing.

A method for obtaining a preform from the above composition may be a conventional method, such as a method of heating and compressing with a mold, a method of pressing into a heated mold, a method of extruding with an extruder, or the like. Can be done. In the case of an extruded product such as a hose or an electric wire, the shape can be maintained even after the extruding, and therefore the extruded preform can be used as it is without using a crosslinking agent. Of course, it is also possible to use a preformed body that has been subjected to heat crosslinking with steam or the like using a crosslinking agent. When it is difficult to maintain the shape of a molded product such as an O-ring in a non-crosslinked state even after the mold is released, it can be carried out by using a preformed product which is pre-crosslinked with a crosslinking agent.

The present invention also relates to the crosslinked product (molded article) thus obtained.

The molded article of the present invention has high mechanical strength and heat resistance. Surprisingly, the compression set, which is a standard for evaluating the sealing property, which is indispensable as a sealing material, is surprisingly small even at a high temperature of 230 ° C. or higher.

The molded article of the present invention can be obtained, for example, from WO99 / 4.
Treatment is carried out according to a special cleaning method described in the No. 9997 pamphlet, that is, a method of cleaning with ultrapure water, a method of cleaning with a liquid clean organic compound or inorganic aqueous solution at a cleaning temperature, a method of dry etching cleaning, and a method of extraction cleaning. As a result, it is possible to obtain a molded article for a semiconductor manufacturing apparatus which is extremely highly cleaned and has a small amount of outgas and excellent plasma resistance.

For example, after the above cleaning, 2 under a nitrogen gas stream.
Molded product heated at 00 ° C for 24 hours (O-ring: AS
-568A-214) can be adjusted to have a weight change of 5% or less, preferably 3% or less when irradiated with oxygen (O ₂ ) plasma and NF ₃ plasma under the irradiation condition (1).

Furthermore, the O-ring after the oxygen plasma irradiation was measured under the following condition (2) (AS-AS (AS
-568A-214) It is possible to provide a clean molded product in which the number of generated particles per particle is 50 × 10 ¹⁴ or less, preferably 30 × 10 ¹⁴ or less.

(Condition (2)) A test O-ring (AS-) obtained by irradiating oxygen plasma under the above irradiation condition (1).
568A-214) in ultrapure water and ultrasonic waves at 25 ° C. for 1 hour to release particles into ultrapure water.
The number of particles (particles) having a particle size of 0.2 μm or more released in this ultrapure water is examined by a fine particle measuring method.

The crosslinkable elastomer composition of the present invention is a molded article for a semiconductor manufacturing apparatus, particularly a seal for sealing a semiconductor manufacturing apparatus which requires a high degree of cleanliness, especially a semiconductor manufacturing apparatus which is subjected to high-density plasma irradiation. It can be preferably used for the production of wood. Examples of the sealing material include O-rings, square rings, gaskets, packings, oil seals, bearing seals and lip seals.

In addition, it can be used as various elastomer products used in semiconductor manufacturing equipment, such as diaphragms, tubes, hoses, and various rubber rolls.
It can also be used as a coating material and a lining material.

The semiconductor manufacturing apparatus referred to in the present invention is not limited to an apparatus for manufacturing a semiconductor in particular, but a wide range of apparatuses such as an apparatus for manufacturing a liquid crystal panel or a plasma panel are required to have a high degree of cleanliness. It includes all manufacturing equipment used in the semiconductor field.

Specifically, the following semiconductor manufacturing apparatus is exemplified.

(1) Etching device Dry etching equipment Plasma etching equipment Reactive ion etching equipment Reactive ion beam etching system Sputter etching equipment Ion beam etching equipment Wet etching equipment Ashing device

(2) Cleaning device Dry etching cleaning device UV / O ₃ cleaning device Ion beam cleaning device Laser beam cleaning device Plasma cleaning device Gas etching cleaning device Extraction cleaning device Soxhlet extraction cleaning device High temperature high pressure extraction cleaning device Microwave extraction cleaning device Supercritical extraction cleaning equipment

(3) Exposure device Stepper Coater / developer

(4) Polishing device CMP equipment

(5) Film forming apparatus CVD equipment Sputtering equipment

(6) Diffusion / ion implantation device Oxidation diffusion device Ion implanter

[0136]

EXAMPLES Next, the present invention will be described with reference to Examples.
The invention is not limited to only such embodiments.

Production Example 1 (Production of Fluorine-Containing Elastomer Containing CN Group) In a stainless steel autoclave having an internal volume of 6 liters and having no ignition source, 2 liters of pure water and an emulsifier were used.

[0138]

[Chemical 31]

20 g and 0.18 g of disodium hydrogen phosphate dodecahydrate as a pH adjuster were charged, the system was sufficiently replaced with nitrogen gas and deaerated, and then the temperature was raised to 50 ° C. while stirring at 600 rpm. And tetrafluoroethylene (T
FE) and perfluoro (methyl vinyl ether) (PM
A mixed gas of VE) (TFE / PMVE = 25/75 molar ratio) was charged so that the internal pressure was 0.78 MPa · G. Then, ammonium persulfate (APS) 527m
20 ml of an aqueous solution having a concentration of g / ml was pressed under nitrogen pressure to start the reaction.

The internal pressure was 0.69 MPa as the polymerization proceeded.
・ At the time of descending to G, CF ₂ = CFOCF ₂ CF (C
F ₃₎ were OCF ₂ CF ₂ CN with (CNVE) 4.6 g was injected by nitrogen pressure. Then, 9.4 g of TFE and 10.6 g of PMVE were each injected under its own pressure so that the pressure became 0.78 MPa · G. Thereafter, as the reaction progressed, TFE and PMVE were similarly pressed in to give 0.69 to 0.7.
While increasing and decreasing the pressure between 8 MPa and G, the total amount of TFE and PMVE is 140 g, 260 g,
CN at the time of 380g and 500g respectively
4.6 g of VE was injected with nitrogen pressure.

20 hours after the initiation of the polymerization reaction, when the total amount of TFE and PMVE charged reached 600 g, the autoclave was cooled to release the unreacted monomer and to disperse the aqueous solution having a solid content concentration of 21.2% by weight. 2650 g of bodies were obtained.

2400 g of this aqueous dispersion was mixed with 72% of water.
It was diluted with 00 g and slowly added to 5600 g of a 3.5 wt% hydrochloric acid aqueous solution with stirring. After the mixture was stirred for 5 minutes, the coagulated product was filtered off, and the obtained polymer was poured into 4 kg of HCFC-141b and stirred for 5 minutes.
I separated it again. Thereafter, the operations of washing with HCFC-141b and filtration were repeated 4 times, and then vacuum dried at 60 ° C. for 72 hours to obtain 500 g of a CN group-containing fluorine-containing elastomer coagulation product.

As a result of ¹⁹ F-NMR analysis, the monomer unit composition of this elastomer was TFE / PMVE / CNVE.
(Mixture of isomers) = 59.2 / 40.0 / 0.8 mol%
Met.

Example 1 (Production of fluorinated aluminum oxide filler) Aluminum oxide filler (A manufactured by Sumitomo Chemical Co., Ltd.)
KP-G008, specific surface area: 80 m ² / g, primary average particle diameter: 0.02 μm, crystal form: θ-type monoclinic system) 60 g was placed in a 1-liter four-necked flask and stirred with polytetrafluoroethylene. While stirring with a blade, nitrogen gas was caused to flow at 250 ° C. for 1 hour at a flow rate of 20 ml / min to create a nitrogen atmosphere. Then, the gas was changed to hexafluoropropylene, and the mixture was flowed at 250 ° C. at a flow rate of 20 ml / min to be brought into contact with the aluminum oxide filler. After 15 minutes, the gas was returned to nitrogen gas and the temperature was lowered to room temperature to produce a fluorinated aluminum oxide filler (Al-1).

Example 2 (Production of Fluorinated Aluminum Oxide Filler) The fluorinated aluminum oxide filler (in the same manner as in Example 1) except that the contact time between hexafluoropropylene and the aluminum oxide filler was 7 hours ( Al
-2) was produced.

Example 3 (fluorinated titanium dioxide)
Manufacture of filler) Titanium dioxide filler (P2 manufactured by Nippon Aerosil Co., Ltd.)
5, specific surface area: 50m ²/ G, primary average particle diameter: 0.0
21 μm) 60 g in a 1-liter four-necked flask
Do not stir with a stirring blade made of polytetrafluoroethylene.
And nitrogen gas at 20 ml / min for 1 hour at 250 ° C.
A nitrogen atmosphere was created by flowing at a flow rate. Hexafu gas
Change to Luoropropylene, 20ml / mi at 250 ℃
flow at a flow rate of n to contact the aluminum oxide filler
It was After 7 hours, the gas was returned to nitrogen gas and the temperature was lowered to room temperature.
Aluminum oxide filler that has been fluorinated by heating
(Al-1) was produced.

Examples 4 to 5 and Comparative Example 1 CN having a carboxyl group at the terminal obtained in Production Example 1
Group-Containing Fluorine-Containing Elastomer and the Journal of
Vo on Polymer Chemistry, Polymer Chemistry
1,2-bis [3-amino- which is a cross-linking agent synthesized by the method described on page 20, 2381 to 2393 (1982).
4- (N-phenylamino) phenyl) hexafluoropropane and fluorinated aluminum oxide filler (Al-1 and Al-2) or untreated aluminum oxide filler (AKP-G008) shown in Table 1 as a filler.
Were mixed in a weight ratio of 100 / 4.25 / 15 and kneaded with an open roll to prepare a crosslinkable fluororubber composition.

This fluororubber composition was pressed at 180 ° C. under the conditions shown in Table 1 for crosslinking, and then subjected to oven crosslinking at 290 ° C. for 18 hours in an oven.
2 mm thick cross-linked product and O-ring (AS-568A
The test sample of -214) was prepared. The crosslinkability, normal state physical properties and compression set of this crosslinked product were measured.
The results are shown in Table 1.

(Crosslinkability) About each crosslinking composition JSR
Vulcanization curve was obtained at the temperature shown in Table 1 by using the type Curastometer II, and the minimum viscosity (νmin), the maximum viscosity (νmax), the induction time (T ₁₀ ) and the optimum vulcanization time (T ₉₀ ) were determined. Ask,

(Normal state physical properties) 100% modulus, tensile strength, tensile elongation and hardness (Shore) in a normal state (25 ° C) of a crosslinked product having a thickness of 2 mm according to JIS K6301.
A hardness) is measured.

(Compression set) 230 of O-ring (AS-568A-214) according to JIS K6301
The compression set after 70 hours at ° C, 275 ° C and 300 ° C is measured.

[0152]

[Table 1]

Example 6 and Comparative Example 2 CN having a carboxyl group at the terminal obtained in Production Example 1
Group-Containing Fluorine-Containing Elastomer and the Journal of
Vo on Polymer Chemistry, Polymer Chemistry
1,2-bis [3-amino- which is a cross-linking agent synthesized by the method described on page 20, 2381 to 2393 (1982).
A weight ratio of 4- (N-phenylamino) phenyl) hexafluoropropane to the fluorinated titanium dioxide filler (Ti-1) or untreated titanium dioxide filler (P25) shown in Table 2 as a filler was 100 / 4.05. / 30
And mixed with an open roll to prepare a crosslinkable fluororubber composition.

This fluororubber composition was pressed at 180 ° C. under the conditions shown in Table 2 to effect crosslinking, and then subjected to oven crosslinking at 290 ° C. for 18 hours in an oven.
2 mm thick cross-linked product and O-ring (AS-568A
The test sample of -214) was prepared. The crosslinkability, normal state physical properties and compression set of this crosslinked product were measured in the same manner as in Example 4. The results are shown in Table 2.

[0155]

[Table 2]

Example 7 (Measurement of Weight Change of Filler Before and After Plasma Irradiation) The fluorinated aluminum oxide filler (Al-2) produced in Examples 1-2, untreated aluminum oxide filler (AKP-G008) and Untreated aluminum oxide filler (Adoma Fine AO-802 made by Tatsumori Co., Ltd.)
Specific surface area: 6 to 8 m ² / g, average particle diameter: 0.7 μm,
Crystal type: α type) was placed in an aluminum container and irradiated with plasma (oxygen plasma and N 2) under the following conditions.
F ₃ plasma) and the weight change before and after irradiation was examined.
The results are shown in Table 3.

Irradiation conditions Working gas: O ₂ , NF ₃ gas flow rate: 16 sccm RF output: 800 W Pressure: 20 mTorr Irradiation time: 30 minutes Frequency: 13.56 MHz

Irradiation Operation In order to stabilize the atmosphere in the chamber of the plasma irradiation apparatus, an actual gas blank discharge is performed for 5 minutes as a chamber pretreatment. Next, an aluminum container containing the sample is placed at the center of the RF electrode, and plasma is irradiated under the above conditions.

Weight Measurement An electronic analysis balance 2006MPE (trade name) manufactured by Sertorious GMBH is used to measure up to 0.01 mg, and the digits of 0.01 mg are rounded off.

[0160]

[Table 3]

From these results, it can be seen that the shielding effect against both oxygen (O ₂ ) and NF ₃ plasmas, which is a characteristic of the aluminum oxide filler, can be maintained even after the fluorination treatment.

Comparative Example 3 An untreated aluminum oxide filler (A
O-802) was used and O was carried out in the same manner as in Example 4.
-A ring was made.

Example 8 (Change in Weight of O-Ring in Plasma Irradiation Test) The O-ring manufactured in Example 5 (using fluorinated aluminum oxide Al-2) had a sufficiently large amount of H ₂ SO ₄ / H _2.
It was washed in an O ₂ (6/4 weight ratio) mixture at 100 ° C. for 15 minutes with stirring, and then with 5% HF at 25 ° C. for 15 minutes.
The sample was washed for 1 minute and boiled with pure water at 100 ° C. for 2 hours, and then dried at 200 ° C. for 24 hours in a nitrogen gas stream to prepare a test sample.

This test sample was irradiated with plasma under the same irradiation conditions as in Example 7, and the weight change before and after irradiation was examined.

For comparison, the O- prepared in Comparative Example 1 (using untreated aluminum oxide AKP-G008) and Comparative Example 3 (using untreated aluminum oxide AO-802).
With respect to the test sample in which the ring was washed and dried in the same manner as above, the weight change before and after the plasma irradiation was examined. The results are shown in Table 4.

[0166]

[Table 4]

Example 9 (Number of Particles Generated After Plasma Irradiation Test of O-Ring) Each test sample irradiated with plasma in Example 8 was put into ultrapure water and subjected to ultrasonic waves at 25 ° C. for 1 hour. The particles were released in ultrapure water. The number of particles (particles) having a particle size of 0.2 μm or more released in this ultrapure water was examined by the fine particle measuring method shown below. The results are shown in Table 5. The number of particles in Table 5 is the number of particles per O-ring.

(Particle measuring method) Light was applied to ultrapure water containing particles that had flown into the sensor section, and the amount of transmitted light or scattered light was measured by a submerged particle counter (KL-22 manufactured by Lion Co., Ltd.). Is a method of electrically measuring.

[0169]

[Table 5]

[0170]

According to the present invention, it is possible to provide a fluorine-containing elastomer molded product that can withstand use at a high temperature of 230 ° C. or higher.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08J 5/00 CEW C08J 5/00 CEW 4J002 C08K 5/00 C08K 5/00 4J037 9/04 9/04 C08L 101/04 C08L 101/04 C09C 1/00 C09C 1/00 1/40 1/40 3/08 3/08 C09K 3/10 C09K 3/10 M (72) Inventor Takafumi Yamagai Nishiichitsuya, Settsu City, Osaka Prefecture No. 1 Daikin Industry Co., Ltd. in Yodogawa Works (72) Inventor Hirofumi Nishibayashi No. 1 Nishiichitsuya, Settsu-shi, Osaka Prefecture No. 1 Daikin Industry Co., Ltd. in Yodogawa Works (72) Katsuhiko Higashino No. 1 Nishiichitsuya, Settsu-shi, Osaka Prefecture No. 1 Daikin Industry Co., Ltd. Yodogawa Works (72) Inventor Go Noguchi 1-1, Nishiichitsuya, Settsu City, Osaka Prefecture Daikin Industry Co., Ltd. Yodogawa Works (72) Inventor Mitsuru Kishine 1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industrial Co., Ltd. Yodogawa Seisakusho F-term (reference) 4F071 AA10 AA26 AA26X AA27 AA27X AA75 AB18 AC12 AE02 AE17 AG05 AG16 AH12 4G042 DA03 DB33 DC03 DD03 DC03 DD03 DE12 4G047 CA01 CB04 CB08 CC03 CD04 4G076 AA02 AB02 AB11 BF06 CA02 CA26 DA02 4H017 AA03 AA24 AB12 AC03 AD01 AE00 AE05 4J002 BD121 BD151 BP031 DE006 DE146 A05 A05 A08 A08A08A08A08A08A05A158A02 EE28 EE44 FF21

Claims (16)

[Claims] 1. An inorganic filler having a primary average particle diameter of 0.5 μm or less (excluding carbon filler),
A modified inorganic filler that has been treated to reduce its surface activity. 2. The modified inorganic filler according to claim 1, wherein the surface activity reducing treatment is a treatment of bringing the inorganic filler into contact with a fluorine compound. 3. The fluorinated filler according to claim 1, wherein the inorganic filler is a metal oxide filler. 4. The fluorinated filler according to claim 3, wherein the metal oxide filler is an aluminum oxide filler. 5. The primary average particle diameter of the inorganic filler is 0.0
It is 5 micrometers or less, The modified inorganic filler in any one of Claims 1-4. 6. The oxygen plasma irradiation and NF ₃ plasma irradiation carried out under the following condition (1), the weight reduction or increase before and after the respective plasma irradiation is 1% or less and 20% or less. The modified inorganic filler according to any one of claims. Flow rate: 16 sccm Pressure: 20 mTorr RF power: 800 W Irradiation time: 30 minutes Frequency: 13.56 MHz 7. The modified inorganic filler according to any one of claims 1 to 6, which is blended with a crosslinking elastomer composition. 8. A cross-linking fluorine-containing elastomer composition comprising the modified inorganic filler according to any one of claims 1 to 7, a cross-linkable group-containing fluorine-containing elastomer, and a cross-linking agent and / or a cross-linking accelerator. 9. The composition according to claim 8, wherein the fluorine-containing elastomer having a crosslinkable group is a perfluoroelastomer having a crosslinkable group. 10. The crosslinkable group of the fluorine-containing elastomer having a crosslinkable group is a CN group or a COOH group.
Or the composition according to 9 above. 11. The cross-linking agent has the formula (1): (In the formula, R ¹ is —SO ₂ —, —O—, —C (═O) —, Alkylidene group having 1 to 10 carbon atoms, a perfluoroalkylidene group or a single bond having 1 to 10 carbon atoms; X ¹ is -O
_{H, -NH 2, -SH, -NHR} (R is a substituted alkyl group which may linear or branched and have 1 to 6 carbon atoms) optionally substituted or -NHAr (Ar phenyl Group or naphthyl group)), a compound represented by the formula (2): (In the formula, R ² is an optionally substituted linear or branched alkylidene group, an optionally substituted arylene group, and (R ³ is —SO ₂ —, —O—, —C (═O) —, Or a compound represented by the formula (3): (In the formula, m is an integer of 1 to 10), a compound represented by the formula (4): (Wherein, X ² is the same or different and both are H or NH ₂ ; p is an integer of 1 to 10), and / or the compound represented by the formula (5): (Wherein X ³ is the same or different, both are H or NH ₂ ; Y is the same or different, both are H or O
The composition according to any one of claims 8 to 10, which is a compound represented by H). 12. The crosslinking agent is R in the formula (1).
¹ is [Chemical 9] And X ¹ is The composition according to claim 11, which is a crosslinking agent that is 13. The composition according to claim 8, wherein the crosslinking accelerator is an organotin compound. 14. A crosslinked fluorine-containing elastomer molded article obtained by crosslinking the fluorine-containing elastomer composition for crosslinking according to any one of claims 8 to 13. 15. The molded product according to claim 14, which is used for sealing a semiconductor manufacturing apparatus. 16. A semiconductor manufacturing apparatus incorporating the molded product according to claim 15.