KR102216742B1 - Low friction polymerizable composition - Google Patents

Abstract

The present invention relates to a polymerizable composition showing high heat resistance and excellent processability, and remarkably improved low friction properties and excellent abrasion resistance, and a prepolymer thereof. The low-friction polymerizable composition of the present invention and its prepolymer can be used as a material for high-speed rotating parts.

Description

Low friction polymerizable composition {LOW FRICTION POLYMERIZABLE COMPOSITION}

The present invention relates to a polymerizable composition having low friction characteristics and excellent heat resistance and a prepolymer thereof.

Engineering plastics are high-performance plastics that can replace metals, and have excellent strength, elasticity, and heat resistance, and are widely used as various industrial materials such as automobile parts, mechanical parts, and electric and electronic parts. In particular, because engineering plastics have self-lubricating properties, they are attracting attention as a lightweight material for high-speed rotating parts to replace metal.

Since the high-speed rotating part is placed in an environment where high rotation and pressure are generated, it must have high heat resistance so that it is not deformed or fused by frictional heat. In addition, in order to reduce energy loss due to friction, it is required to have excellent friction characteristics.

Accordingly, high heat-resistant super engineering plastics such as PEEK (Polyether ether ketone), PAI (Polyamide imide), PI (Polyimide), etc., which have high heat resistance and low friction characteristics, are mainly used as materials for the high-speed rotating parts. However, PEEK has relatively low heat resistance and is still inappropriate as a component exposed to ultra-high pressure and high-speed environments, and PAI and PI are limited in application to parts due to low processability, productivity, and high price.

Therefore, it is necessary to develop a material having high heat resistance and low friction characteristics and excellent workability so as to be used for high-speed rotating parts.

U.S. Patent 4,408,035 U.S. Patent No. 5,003,039 U.S. Patent No. 5,003,078 U.S. Patent No. 5,004,801 U.S. Patent No. 5,132,396 U.S. Patent No. 5,139,054 U.S. Patent No. 5,208,318 U.S. Patent No. 5,237,045 U.S. Patent No. 5,292,854 U.S. Patent No. 5,350,828

The present invention is to provide a low-friction polymerizable composition having high heat resistance and excellent processability while exhibiting low friction characteristics.

In addition, the present invention is to provide a prepolymer which is a reactant of such a low friction polymerizable composition.

In order to solve the above problems, the present invention,

Phthalonitrile compounds;

Hardener; And

It provides a low-friction phthalonitrile resin composite containing; a filler including expanded graphite and a fluororesin.

Hereinafter, the term "low friction polymerizable composition" used in the present invention refers to a composition capable of producing a phthalonitrile resin by polymerizing a phthalonitrile compound with a curing agent included while exhibiting low friction characteristics.

These phthalonitrile resins include one or more phthalonitrile substituents in the molecule, exhibiting an appropriate processing temperature and a wide process window, and excellent thermal properties. That is, the phthalonitrile resin has high heat resistance and at the same time has excellent processability, so that mixing with other additives is easy, so that a composite having excellent physical properties can be easily prepared.

Accordingly, the polymerizable composition of the present invention comprises a phthalonitrile compound capable of producing a phthalonitrile resin having high heat resistance and excellent processability, a curing agent thereof, a filler having a specific composition and content capable of improving low friction properties, and It is a composition that realizes low friction characteristics by mixing, and using such a composition, a material for high-speed rotating parts having durability and reliability can be manufactured even in an ultra-high pressure and ultra-high speed environment.

Hereinafter, the present invention will be described in more detail.

Low friction polymerizable composition

The low-friction polymerizable composition according to the present invention includes a phthalonitrile compound;

Hardener; And

It includes; a filler including expanded graphite and a fluororesin.

The kind of phthalonitrile compound that can be used in the polymerizable composition is not particularly limited, but, for example, a phthalonitrile structure capable of forming a phthalonitrile resin through reaction with a curing agent with the phthalonitrile compound A compound containing about 2 or more, 2 to 20, 2 to 16, 2 to 12, 2 to 8, or 2 to 4 may be used. There are various compounds known to be suitable for the formation of the phthalonitrile resin, and all of the known compounds as described above may be used in the present application. Examples of compounds in one example are U.S. Patent No. 4,408,035, U.S. Patent No. 5,003,039, U.S. Patent No. 5,003,078, U.S. Patent No. 5,004,801, U.S. Pat. , U.S. Patent No. 5,237,045, U.S. Patent No. 5,292,854, or U.S. Patent No. 5,350,828 may be exemplified, and various compounds known in the art may be included in the examples. .

Meanwhile, the low-friction polymerizable composition includes a curing agent capable of curing the phthalonitrile compound in a ratio of 0.02 mol to 1.5 mol based on 1 mol of the phthalonitrile compound. When the curing agent is used in an amount of less than 0.02 moles relative to 1 mole of the phthalonitrile compound, the phthalonitrile compound tends to be insufficiently cured due to insufficient curing, and the curing agent exceeds 1.5 moles relative to 1 mole of the phthalonitrile compound When used as, there is a problem that the process window of the polymerizable composition is narrowed.

The curing agent capable of curing the phthalonitrile compound is not particularly limited as long as it can react with the phthalonitrile compound to form a phthalonitrile resin. For example, the curing agent is an amine compound, a hydroxyl At least one selected from the group consisting of clock compounds, imide compounds, inorganic acid compounds, and organic acid compounds may be used. The amine-based compound, hydroxy-based compound, and imide-based compound each mean a compound containing at least one amino group, a hydroxy group, and an imide group in a molecule.

Specifically, for example, the curing agent may be an imide-based compound represented by the following Formula 1:

[Formula 1]

In Formula 1,

M is a tetravalent radical derived from an aliphatic, alicyclic or aromatic compound,

X ₁ and X ₂ are each independently an alkylene group, an alkylidene group, or a divalent radical derived from an aromatic compound,

n is a number of 1 or more.

Since the imide-based compound represented by Formula 1 contains an imide structure in the molecule, it exhibits excellent heat resistance and is included in excess in the polymerizable composition, or has an adverse effect on physical properties even when the polymerizable composition is processed or cured at a high temperature. It is possible to prepare a polymerizable composition that does not produce defects such as possible voids.

In Formula 1, M may be a tetravalent radical derived from an aliphatic, alicyclic, or aromatic compound. In this case, the radical formed by the removal of 4 hydrogen atoms in a molecule from the aliphatic, alicyclic or aromatic compound is each of the formula 1 It may have a structure connected to the carbon atom of the carbonyl group.

As the aliphatic compound in the above, linear or branched alkanes, alkenes, or alkynes may be exemplified. As the aliphatic compound, alkanes, alkenes, or alkynes having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms may be used. The alkanes, alkenes, or alkynes may be optionally substituted by one or more substituents.

As the alicyclic compound in the above, a hydrocarbon compound including a non-aromatic ring structure having 3 to 20 carbon atoms, 3 to 16 carbon atoms, 3 to 12 carbon atoms, 3 to 8 carbon atoms, or 3 to 4 carbon atoms may be exemplified. These alicyclic hydrocarbon compounds may contain at least one hetero atom such as oxygen or nitrogen as a ring constituent atom, and may optionally be substituted with one or more substituents if necessary.

In addition, as the aromatic compound in the above, benzene, a compound containing benzene, or any one of the above derivatives may be exemplified. In the above, the benzene-containing compound may refer to a compound having a structure in which two or more benzene rings are condensed while sharing one or two carbon atoms, or are directly connected or connected by an appropriate linker. have. As a linker applied to linking two benzene rings in the above, an alkylene group, an alkylidene group, -O-, -S-, -C(=O)-, -S(=O)-, -S( =O) ₂ -, -C(=O)-OL ₁ -OC(=O)-, -L ₂ -C(=O)-OL ₃ -, -L ₄ -OC(=O)-L _5- , Or -L ₆ -Ar ₁ -L ₇ -Ar ₂ -L ₈ -and the like may be exemplified. In the above, L ₁ to L ₈ are each independently a single bond, -O-, an alkylene group, or an alkylidene group, and Ar ₁ and Ar ₂ may each independently be an arylene group. The aromatic compound may contain, for example, 6 to 30, 6 to 28, 6 to 27, 6 to 25, 6 to 20 or 6 to 12 carbon atoms. And, if necessary, may be substituted by one or more substituents. In the above, the number of carbon atoms in the aromatic compound is the number including carbon atoms present in the linker when the compound includes the linker described above.

Specifically, for example, in Formula 1, M may be a tetravalent radical derived from an alkane, an alkene, or an alkyne, or may be a tetravalent radical derived from a compound represented by any one of the following Formulas 2 to 7.

[Formula 2]

In Formula 2, R ₁ to R ₆ are each independently hydrogen, an alkyl group, an alkoxy group, or an aryl group.

[Formula 3]

In Formula 3, R ₁ to R ₈ are each independently hydrogen, an alkyl group, an alkoxy group, or an aryl group.

[Formula 4]

In Chemical Formula 4,

R ₁ to R ₁₀ are each independently hydrogen, an alkyl group, an alkoxy group, or an aryl group,

X is a single bond, an alkylene group, an alkylidene group, -O-, -S-, -C(=O)-, -S(=O)-, -S(=O) ₂ -, -C(=O )-OL ₁ -OC(=O)-, -L ₂ -C(=O)-OL ₃ -, -L ₄ -OC(=O)-L ₅ -, or -L ₆ -Ar ₁ -L ₇ -Ar ₂ -L ₈ -, wherein L ₁ to L ₈ are each independently a single bond, -O-, an alkylene group, or an alkylidene group, and Ar ₁ and Ar ₂ are each independently an arylene group.

In this case, in the present specification, a single bond refers to a case where an atom does not exist in the portion. Accordingly, when X is a single bond in Chemical Formula 4, it means that no atoms exist in the portion represented by X, and in this case, the benzene rings on both sides of X may be directly connected to form a biphenyl structure.

In Formula 4, in the X -C(=O)-OL ₁ -OC(=O)-, -L ₂ -C(=O)-OL ₃ -, or -L ₄ -OC(=O)- In L ₅ -, L ₁ to L ₅ may each independently be an alkylene group or an alkylidene group having 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, and the alkylene group or the alkylidene group is substituted or unsubstituted Can be. In addition, in X of Formula 4-L ₆ -Ar ₁ -L ₇ -Ar ₂ -L ₈ -, in the above, L ₆ and L ₈ may be -O-, and L ₇ may be. It may be an alkylene group or an alkylidene group having 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, and the alkylene group or alkylidene group may be substituted or unsubstituted. Meanwhile, in the above, Ar ₁ and Ar ₂ may be a phenylene group, and in this case, L ₆ and L8 may be connected to the ortho, meta or para positions of the phenylene, respectively, based on L ₇ .

[Formula 5]

In Chemical Formula 5,

R ₁ to R ₄ are each independently hydrogen, an alkyl group, or an alkoxy group, but two of R ₁ to R ₄ may be connected to each other to form an alkylene group,

A is an alkylene group or an alkenylene group, but the alkylene group or alkenylene group of A may contain one or more oxygen atoms as a hetero atom.

[Formula 6]

In Formula 6, R ₁ to R ₄ are each independently hydrogen, an alkyl group, or an alkoxy group, and A is an alkylene group.

[Formula 7]

In Formula 7, R ₁ to R ₁₀ are each independently hydrogen, an alkyl group, or an alkoxy group.

The tetravalent radical derived from the compound represented by Formulas 2 to 7 is formed by directly leaving R ₁ to R _{10 as} a substituent of Formulas 2 to 7 or an alkyl group which is a substituent that may be present in R ₁ to R ₁₀ , A hydrogen atom belonging to an alkoxy group, an aryl group, an alkylene group, or an alkenylene group may be removed and formed.

For example, when the tetravalent radical is derived from a compound of Formula 3, one or more, 2 or more, 3 or more, or 4 of R ₁ to R ₆ of Formula 3 form a radical, or the R ₁ The radical may be formed by removing the hydrogen atom of the alkyl group, alkoxy group, or aryl group present in to R ₆ . Forming a radical in the above may mean that the moiety is connected to the carbon atom of the carbonyl group of Formula 1 as described above.

In addition, when the tetravalent radical is derived from a compound of Formula 4, R ₁ to R ₁₀ in Formula 4 are each independently hydrogen, an alkyl group, an alkoxy group, or an aryl group, but one or more, two or more, three More than or four may form a radical linked to Formula 1. Each of which does not form a radical may be hydrogen, an alkyl group or an alkoxy group, or may be a hydrogen or an alkyl group. In one example, in Formula 4, any two of R ₇ to R ₉ and any two of R ₂ to R ₄ may form the radical, and the other substituents are each independently hydrogen, an alkyl group, an alkoxy group, or an aryl group, It may be hydrogen, an alkyl group or an alkoxy group, or may be a hydrogen or an alkyl group.

More specifically, for example, the compound represented by Formula 2 may be benzene or 1,2,4,5-tetraalkylbenzene, but is not limited thereto.

In addition, the compound represented by Formula 4 may be biphenyl, or may be a compound represented by any one of the following Formulas A to F, but is not limited thereto:

[Formula A]

[Formula B]

[Formula C]

[Formula D]

[Formula E]

[Formula F]

.

.

In addition, the compound represented by Formula 5 is a cycloalkane having 4 to 8 carbon atoms such as cyclohexane, a cycloalkene having 4 to 8 carbon atoms such as cyclohexene which may be substituted with one or more alkyl groups, or one of the following formulas G to I It may be a compound represented by any one of the formulas, but is not limited thereto:

[Formula G]

[Formula H]

[Formula I]

In addition, the compound represented by Formula 6 may be a compound represented by the following Formula J, or in which at least one of the hydrogens of the compound represented by the following Formula J is substituted with an alkyl group, but is not limited thereto:

[Formula J]

In Formula 1, X ₁ and X ₂ may each independently be a divalent radical derived from an aromatic compound. For example, X ₁ and X ₂ may each independently be a divalent radical derived from an aromatic compound having 6 to 40 carbon atoms. At this time, the divalent radical derived from the aromatic compound may be a divalent radical derived from the aromatic compound described above.

Specifically, for example, X ₁ and X ₂ may each independently be a divalent radical derived from a compound represented by any one of the following Formulas 8 to 10.

[Formula 8]

In Formula 8, R ₁₁ to R ₁₆ are each independently hydrogen, an alkyl group, an alkoxy group, an aryl group, a hydroxy group, or a carboxyl group.

[Formula 9]

In Formula 9,

R ₁₁ to R ₂₀ are each independently hydrogen, an alkyl group, an alkoxy group, an aryl group, a hydroxy group, or a carboxyl group,

X'is a single bond, an alkylene group, an alkylidene group, -O-, -S-, -C(=O)-, -NR ₂₁ -, -S(=O)-, -S(=O) _2- , -L ₉ -Ar ₃ -L ₁₀ -or -L ₁₁ -Ar ₄ -L ₁₂ -Ar ₅ -L ₁₃ -, wherein R ₂₁ is hydrogen, an alkyl group, an alkoxy group, or an aryl group, and L ₉ to L ₁₃ is each independently a single bond, -O-, an alkylene group, or an alkylidene group, and Ar ₃ to Ar ₅ are each independently an arylene group.

[Formula 10]

In Formula 10, R ₁₁ to R ₂₀ are each independently hydrogen, an alkyl group, an alkoxy group, an aryl group, a hydroxy group, or a carboxyl group.

The divalent radical derived from the compound represented by Chemical Formulas 8 to 10 is formed by directly leaving R ₁₁ to R _{20 as} a substituent of Chemical Formulas 8 to 10, or an alkyl group which is a substituent that may be present in R ₁₁ to R ₂₀ , A hydrogen atom belonging to an alkoxy group, an aryl group, an alkylene group, or an alkenylene group may be removed and formed.

For example, if the divalent radical is derived from the compound represented by Formula 8, for example, phenylene, the substitution position of the amine group based on the site connected to N in X ₁ of Formula 1 is ortho ( Ortho), meta (meta) or para (para) position may be, and the substitution position of the amine group based on the site connected to N in X ₂ of Formula 1 is also ortho, meta, or para. (para) may be a position.

In addition, when the divalent radical is derived from the compound represented by Formula ₉ , any one of R ₇ to R ₉ of Formula 9 and any of R ₂ to R ₄ of Formula 9 are connected to the nitrogen atom of Formula 1 Can form radicals. The substituents other than the substituent forming the radical may each independently be hydrogen, an alkyl group, an alkoxy group or an aryl group, a hydrogen, an alkyl group or an alkoxy group, or a hydrogen or an alkyl group.

More specifically, for example, the compound represented by Formula 8 may include benzene, which may be substituted with at least one hydroxy group or carboxyl group, but is not limited thereto.

In addition, the compound represented by Formula 9 is biphenyl which may be substituted with at least one hydroxy group or carboxyl group, a compound which may be substituted with at least one hydroxy group or carboxyl group as represented by any one of Formulas A to F, or the following A compound represented by Formula K or M and which may be substituted with at least one hydroxy group or carboxyl group may be exemplified, but is not limited thereto.

[Formula K]

[Formula L]

[Formula M]

In addition, the compound represented by Formula 10 may be a compound represented by Formula N below or in which at least one of the hydrogens of the compound represented by Formula N is substituted with a hydroxy group or a carboxyl group, but is not limited thereto. :

[Formula N]

In the present specification, the alkyl group may be an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms unless otherwise specified. The alkyl group may be straight chain, branched chain, or cyclic, and may be substituted by one or more substituents if necessary.

In the present specification, the alkoxy group may be an alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms unless otherwise specified. The alkoxy group may be linear, branched, or cyclic, and may be substituted by one or more substituents if necessary.

In the present specification, the aryl group may mean a monovalent residue derived from the above-described aromatic compound, unless otherwise specified.

In the present specification, the alkylene group or the alkylidene group is an alkylene group or an alkylidene group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms unless otherwise specified. It can mean. The alkylene group or the alkylidene group may be linear, branched, or cyclic. In addition, the alkylene group or the alkylidene group may be optionally substituted with one or more substituents.

In the present application, as a substituent that may be optionally substituted with an aliphatic compound, alicyclic compound, aromatic compound, alkyl group, alkoxy group, aryl group, alkylene group, or alkylidene group, halogen, glycidyl group such as chlorine or fluorine , An epoxy group such as an epoxy alkyl group, a glycidoxyalkyl group or an alicyclic epoxy group, an acryloyl group, a methacryloyl group, an isocyanate group, a thiol group, an alkyl group, an alkoxy group, or an aryl group, etc., but are limited thereto. no.

In addition, in Formula 1, n refers to the number of imide repeating units, and 2 to 200, 2 to 150, 2 to 100, 2 to 90, 2 to 80, 2 to 70, 2 to 60, 2 to 50 , 2 to 40, 2 to 30, may be a number within the range of 20, or 2 to 10.

In this case, when n is 2 or more in Formula 1, that is, when the compound of Formula 1 is a polyimide compound, it may be more advantageous in terms of heat resistance and strength. Therefore, in the case of a material for high-speed rotating parts including a phthalonitrile resin cured using a polyimide compound, it has higher heat resistance, so that deformation and fusion of the phthalonitrile resin can be prevented under high-speed and high-pressure conditions, and higher strength. Because of this, it can show low wear and high durability.

Meanwhile, the compound represented by Formula 1 may be synthesized according to a known synthesis method of an organic compound, and a specific method thereof is not particularly limited. For example, the compound represented by Formula 1 can be formed by a dehydration condensation reaction of a dianhydride compound and a diamine compound.

In addition, the compound represented by Formula 1 has a high boiling point, and thus does not volatilize or decompose at high temperature, and thus, while maintaining the curability of the polymerizable composition stably, it may adversely affect physical properties during processing or curing at high temperature. It does not form a void. Accordingly, in one example, the compound may have a decomposition temperature of 300°C or higher, 350°C or higher, 400°C or higher, or 500°C or higher. In this case, the decomposition temperature may mean a temperature at which the decomposition rate of the compound represented by Formula 1 is maintained in a range of 10% or less, 5% or less, or 1% or less. In the above, the upper limit of the decomposition temperature is not particularly limited, but may be, for example, about 1,000° C. or less.

In addition, the compound represented by Formula 1 is a process window of the reactive or polymerizable composition itself, that is, the polymerizable composition or a prepolymer formed therefrom by selection of M of the core or X ₁ or X _{2 as} a linker. Since the difference between the melting temperature and the curing temperature of can be easily controlled, it can act as a curing agent for various physical properties depending on the application.

On the other hand, the low-friction polymerizable composition includes a filler including expanded graphite and a fluororesin to reduce erosion on the opposite surface in an ultra-high pressure and ultra-high speed environment and increase abrasion resistance to impart low friction properties.

If a fluororesin is used alone as a filler in a mixture of a phthalonitrile compound and a curing agent, the mixture and the fluororesin do not mix well due to the difference in polarity, and thus low friction properties cannot be secured. However, when expanded graphite is included together with the fluororesin, the viscosity of the mixture of the phthalonitrile compound and the curing agent increases due to the low density of the expanded graphite, thereby allowing the fluororesin to be homogeneously mixed with the mixture. In addition, the thus prepared composition exhibits low friction characteristics and wear resistance, and is suitable for use in high-speed rotating parts such as bushings, thrust washers, bearings, O-ring parts, or sealing.

In order to secure the above-described effect, the expanded graphite used in the present invention preferably has a density of 1.5 g/cm 3 　 or less, or 0.8 g/cm 3 　 or less. The lower limit of the density of the expanded graphite is not limited, but may be, for example, 0.001 g/cm 3 　 or more, or 0.01 g/cm 3 　 or more. If the density of the expanded graphite exceeds 1.5 g/cm 3 　, the effect of increasing the viscosity of the mixture of the phthalonitrile compound and the curing agent cannot be increased, and thus the fluororesin cannot be evenly dispersed in the composition. Therefore, it is desirable to satisfy the above range.

Although not intended to be limiting, the BET specific surface area of the expanded graphite is 5 m ² /g or more, 6 m ² /g, or 8 m ² /g or more, and 100 m ² /g or less, 75 m ² /g or less, or It is preferable to be 50 m ² /g or less in terms of securing hardness and friction characteristics.

The fluororesin that can be used in the present invention is not particularly limited, and a fluororesin commonly used for friction materials may be used. Specifically, the fluororesin includes polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, and tetrafluoroethylene. At least one selected from the group consisting of fluoroethylene-fluoroalkylvinylether-fluoroolefin copolymer, ethylene-trichlorofluoroethylene copolymer, and polyvinylidene fluoride may be used. According to an embodiment of the present invention, polytetrafluoroethylene may be used as the fluororesin.

The average particle diameter of the fluororesin is not particularly limited, but may be, for example, 100 μm or less, 50 μm or less, or 10 μm or less. The lower limit of the average particle diameter of the fluororesin is not limited, but may be, for example, 0.001 μm or more, or 0.005 μm or more, or 0.01 μm or more. If the average particle diameter of the fluororesin is larger than 100 μm, it is difficult to secure low friction characteristics, so it is preferable to satisfy the above range.

In addition, in the present invention, the expanded graphite and the fluororesin are preferably included in a weight ratio of 1:10 to 10:1, or a weight ratio of 5:1 to 1:5. If the weight ratio of the expanded graphite and the fluororesin is less than 1:10, the viscosity of the composition cannot be sufficiently increased, so it is difficult for the fluororesin to be uniformly dispersed in the composition, and if it exceeds 10:1, the low-friction property of the composition is insufficient. Since there is a problem to be used, it is appropriately adjusted within the above range.

On the other hand, the low-friction polymerizable composition of the present invention may contain only the expanded graphite and fluorine resin as a filler, but may further include an inorganic filler or an organic filler commonly used within a range that does not impair the effect of the present invention. I can. For example, general graphite may be further included as a filler other than the expanded graphite and fluororesin.

The content of these inorganic or organic fillers is not particularly limited, but it is preferable to use in a range of less than 50% by weight based on the total 100% by weight of the filler contained in the low friction polymerizable composition in terms of securing low friction properties, and 30% by weight. It is more preferable to use less than %.

Examples of the inorganic or organic filler include glass fiber, molybdenum disulfide, antimony trisulfide, antimony trioxide, barium sulfate, calcium hydroxide, calcium carbonate, magnesium oxide, zinc oxide, titanium oxide, silicon nitride, calcium fluoride, silica, alumina, iron oxide. , Chromium oxide, zirconium oxide, boron nitride, tungsten sulfide, carbon nanotubes, carbon fibers, graphite, and one or more selected from the group consisting of graphene, but are not limited thereto.

In the present invention, the filler containing expanded graphite and fluororesin is 1% by weight or more, 5% by weight or more, or 10% by weight or more, 50% by weight or less, or 45% by weight or less based on 100% by weight of the low friction polymerizable composition. , Or 30% by weight or less. If the content of the filler is less than 1% by weight based on 100% by weight of the low-friction polymerizable composition, the effect of reducing the coefficient of friction cannot be sufficiently secured, so severe friction and vibration due to this may occur when rotating at high speed and high pressure. . In addition, when the filler is used in an amount of more than 50% by weight, sufficient strength cannot be secured, and thus it may be destroyed in high-speed and high-pressure conditions or by impact.

In order to confirm whether the above-described polymerizable composition exhibits low friction characteristics, the coefficient of friction and wear-rate may be measured according to ASTM D3702 standard. In particular, as can be seen in the examples to be described later, the polymerizable composition exhibits a low coefficient of friction and abrasion rate due to low friction characteristics even under high pressure and high rotational speed conditions for various types of friction target materials. You can see that it can be applied.

At this time, the ASTM D3702 standard is for measuring the friction coefficient and the wear rate of the thrust washer specimen in order to check whether it is suitable for use as a self-lubricating material, and ASTM D3702 standard using a friction coefficient measuring device as shown in FIG. It is possible to measure the coefficient of friction and wear rate according to.

Specifically, the method of obtaining the coefficient of friction and the wear rate according to ASTM D3702 standard is as follows:

1) The polymerizable composition is cured to prepare a test specimen having the size and thickness specified in ASTM D3702 standard.

2) Install the prepared specimen in the upper specimen holder of the friction coefficient measuring device.

3) Install the friction material in the stationary specimen holder of the friction coefficient measuring machine (in the case of Fig. 1, a steel washer is installed as the friction material).

4) Friction coefficient By setting a specific pressure (P) and rotational speed (V) on the measuring instrument, the friction coefficient ( f ) under the desired PV Value (multiplied by pressure and speed) condition can be obtained by Equation 1 below.

[Equation 1]

In Equation 1 above,

T is the torque applied to the specimen (Nm), r is the radius of the specimen (mm), and W is the perpendicular force (kg).

In addition, the wear rate, the experiment before / after the following standard by measuring the change in mass divided by density, to obtain a wear volume through this, the second reduced thickness obtained on the basis of reduced thickness obtained by dividing the calculated volume change in the width of the rings (10 ^-10 m/s).

In addition, the above-described low-friction polymerizable composition may have a processing temperature in the range of 150°C to 350°C. In this case, the processing temperature means a temperature at which the polymerizable composition is present in a processable state. This processing temperature may be, for example, a melting temperature (Tm) or a glass transition temperature (Tg). In this case, the absolute value of the process window of the polymerizable composition, that is, the difference between the processing temperature (Tp) and the curing temperature (Tc) of the phthalonitrile compound and the curing agent (Tc-Tp) is 30°C or higher, 50°C It may be greater than or equal to or greater than 100°C. In one example, the curing temperature Tc may be higher than the processing temperature Tp. Such a range may be advantageous in securing suitable processability in the process of manufacturing a material for high-speed rotating parts, for example, using a polymerizable composition. Although the upper limit of the process window is not particularly limited, for example, the absolute value of the difference (Tc-Tp) between the processing temperature Tp and the curing temperature Tc may be 400°C or less or 300°C or less.

Low friction prepolymer

On the other hand, the present invention provides a low friction prepolymer (prepolymer) that is a reactant of the low friction polymerizable composition described above.

Here, the prepolymer state is a state in which the reaction between the phthalonitrile compound and the curing agent in the polymerizable composition to some extent (for example, a state in which the so-called A or B stage polymerization has occurred), or a completely polymerized state It may mean a state that does not reach a state, but exhibits appropriate fluidity and can be processed.

In addition, the prepolymer state corresponds to a state in which polymerization of the polymerizable composition has progressed to some extent, and the melt viscosity measured at a temperature within the range of about 150°C to 250°C is 10 Pas to 100,000 Pas, 10 Pas to 10,000 Pas, or may mean a state in the range of 10 Pas to 5,000 Pas. Accordingly, the prepolymer, like the polymerizable composition, can exhibit excellent curability, a low melting temperature, and a wide process window.

For example, the processing temperature of the prepolymer may be in the range of 150 ℃ to 350 ℃. In this case, the processing temperature means a temperature at which the prepolymer is present in a processable state. This processing temperature may be, for example, a melting temperature (Tm) or a glass transition temperature (Tg). In this case, the absolute value of the difference (Tc-Tp) between the process window of the prepolymer, that is, the processing temperature Tp and the curing temperature Tc of the prepolymer may be 30°C or more, 50°C or more, or 100°C or more. In one example, the curing temperature Tc may be higher than the processing temperature Tp. Such a range may be advantageous in securing an appropriate processability in the process of manufacturing a material for a high-speed rotating part to be described later using, for example, a prepolymer. Although the upper limit of the process window is not particularly limited, for example, the absolute value of the difference (Tc-Tp) between the processing temperature Tp and the curing temperature Tc may be 400°C or less or 300°C or less.

The low-friction polymerizable composition or prepolymer of the present invention described above not only has high heat resistance and excellent processability, but also has excellent low-friction characteristics, and has durability and reliability even in an ultra-high pressure and ultra-high speed environment. Therefore, the low friction polymerizable composition or prepolymer of the present invention can be used as a material for high-speed rotating parts.

The low friction polymerizable composition of the present invention exhibits high heat resistance and excellent processability, and has remarkably improved low friction properties and excellent wear resistance. Therefore, the low-friction polymerizable composition of the present invention can be used as a material for high-speed rotating parts.

1 is an exploded perspective view of a friction coefficient measuring device for measuring the friction coefficient according to ASTM D3702 standard.

Hereinafter, preferred embodiments are presented to aid the understanding of the present invention, but the following examples are only illustrative of the present invention, and it is obvious to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention. It is natural that changes and modifications fall within the scope of the appended claims.

^One H-NMR (Nuclear Magnetic Resonance) analysis

The NMR analysis of the compound prepared below was performed according to the manufacturer's manual using Agilent's 500 MHz NMR equipment. A sample for NMR measurement was prepared by dissolving the compound in dimethyl sulfoxide (DMSO)-d6.

Preparation Example 1. Synthesis of phthalonitrile compound (PN1)

Compound (PN1) of the following formula 11 was synthesized in the following manner. 32.1 g and 120 g of DMF (Dimethyl Formamide) of the following Chemical Formula 12 were added to a 3-neck round bottom flask (RBF), followed by stirring at room temperature to dissolve. Then, 55.4 g of the compound of the following formula 13 was added, and 60 g of DMF was added, followed by stirring to dissolve. Then, 66.3 g of potassium carbonate and 50 g of DMF were added together, and the temperature was raised to 85° C. while stirring. After reacting in the above state for about 5 hours, it was cooled to room temperature. The cooled reaction solution was poured into an aqueous solution of hydrochloric acid having a concentration of 0.2N to neutralize and precipitate, filtered, and washed with water. Thereafter, the filtered reaction product was dried in a vacuum oven at 100° C. for 1 day, and after removing water and residual solvent, a compound of Formula 11 (PN1) was obtained in a yield of about 88% by weight.

[Formula 11]

[Formula 12]

[Formula 13]

Preparation Example 2. Synthesis of curing agent compound (CA1)

The compound of formula 14 (CA1) was synthesized by dehydration condensation of diamine and dianhydride. 24 g of 4,4'-oxydianiline and 40 g of NMP (N-methyl-pyrrolidone) were added to a 3-neck round bottom flask (RBF) and dissolved by stirring at room temperature. . The above was cooled with a water bath, and 8.7 g of the compound represented by the following formula (15) was gradually divided in 3 times and added together with 40 g of NMP. When all the added compounds were dissolved, 16 g of toluene was added to the reaction for azeotrope. A Dean-Stark device and a reflux capacitor were installed, and toluene was added to the Dean-Stark device to fill. 4.2 mL of pyridine was added as a dehydration condensation catalyst, the temperature was raised to 170° C., and stirred for 3 hours. The water generated while the imide ring was formed was further stirred for 2 hours while removing it with a Dean Stark device, and residual toluene and pyridine were removed. The reaction product was cooled to room temperature, precipitated in methanol, and recovered. The recovered precipitate was extracted with methanol to remove residual reactants, and dried in a vacuum oven to obtain a compound of Formula 14 (CA1) in a yield of about 85% by weight.

[Formula 14]

[Formula 15]

Example 1

100 parts by weight of the compound (PN1) of Preparation Example 1, about 0.18 moles of the compound (CA1) of Preparation Example 2 relative to 1 mole of the compound (PN1), expanded graphite (density 0.2 g/cm 3, BET specific surface area 22 m ² / g) 17.6 parts by weight and 17.6 parts by weight of polytetrafluoroethylene (PTFE, average particle diameter 4 μm) were added and then mixed well to prepare a polymerizable composition.

Comparative Example 1

The 450FC30 product of Victrex's low friction grade was commercially obtained and used. The 450FC30 product contains 10% by weight of graphite, 10% by weight of Teflon particles, and 10% by weight of carbon fiber (14.3 parts by weight of graphite, 14.3 parts by weight of Teflon particles and 14.3 parts by weight of carbon fiber based on 100 parts by weight of PEEK resin) in PEEK resin. It is known.

Comparative Example 2

Vespel-SP21, a low-friction grade from DuPont, was commercially obtained and used. Vespel-SP21 is known to contain 15% by weight of graphite (17.6 parts by weight of graphite based on 100 parts by weight of PI resin) in polyimide resin.

Comparative Example 3

100 parts by weight of the compound (PN1) of Preparation Example 1, about 0.18 moles of the compound (CA1) of Preparation Example 2 and 1 mole of the compound (PN1) and expanded graphite (density 0.1 g/cm 3, BET specific surface area 22 m ² / g) 17.6 parts by weight were added and mixed well to prepare a polymerizable composition.

Comparative Example 4

After adding 100 parts by weight of the compound (PN1) of Preparation Example 1, about 0.18 moles of the compound (CA1) of Preparation Example 2 and 17.6 parts by weight of general graphite (density 5 g/cm 3) relative to 1 mole of the compound (PN1) By mixing to prepare a polymerizable composition.

Comparative Example 4

100 parts by weight of the compound (PN1) of Preparation Example 1, about 0.18 moles of the compound (CA1) of Preparation Example 2 relative to 1 mole of the compound (PN1), 17.6 parts by weight of general graphite (density 5 g/cm 3) and polytetrafluoro After adding 11.1 parts by weight of ethylene (PTFE), it was mixed well to prepare a polymerizable composition.

Experimental Example 1-Evaluation of coefficient of friction and wear rate for carbon steel as counterpart

The polymerizable composition prepared in Examples 1 to 5 was melted at 240°C and stirred for 5 minutes to prepare a prepolymer, and then the prepared prepolymer was put in a mold and melted, and then the temperature was raised from 200°C to 300°C for 2 hours. During hardening, it was prepared as a specimen according to ASTM D3702 standard. In addition, the products of Comparative Examples 1 and 2 were cut to prepare a specimen according to ASTM D3702 standard.

At this time, S45C was prepared as the counterpart carbon steel. S45C refers to a carbon steel material for mechanical structures, which is a steel material containing 0.45% carbon according to JIS G4053 standards.

According to the ASTM D3702 standard described above, the friction coefficient and the wear rate of the prepared Example and Comparative Example specimens were measured using a friction coefficient measuring device (manufactured by Phoenix Corporation). Specific measurement conditions are as follows. The results are shown in Table 1 below.

-PV Value 1: 2.3 MPam/s (Pressure (P): 1.63 MPa (16 bar, 220 N), Rotation speed (V): 1.41 m/s (1000 rpm))

-PV Value 2: 4.6 MPam/s (Pressure (P): 1.63 MPa (16 bar, 220 N), Rotation speed (V): 2.82 m/s (2000 rpm))

-Time: 1200 s

-Unlubricated operation

Furtherance PV Value 1 condition Under PV Value 2 condition
Whether thermal deformation Resin type Filler Coefficient of friction Wear rate
(10 ^-10 m/s) Example 1 Phthalonitrile Expanded graphite + PTFE 0.114 132 No thermal deformation Comparative Example 1 PEEK Graphite + Teflon + Carbon Fiber 0.18 76 Heat deformation Comparative Example 2 PI black smoke 0.3 - Impossible to measure due to vibration Comparative Example 3 Phthalonitrile Expanded graphite 0.22 80 No thermal deformation Comparative Example 4 Phthalonitrile black smoke 0.18 193 Not measured Comparative Example 5 Phthalonitrile Graphite+PTFE 0.28 151 Not measured

Referring to Table 1, it can be seen that the specimen of Example 1 contains expanded graphite and PTFE as fillers, and exhibits a lower coefficient of friction than a commercially available low-friction resin. In addition, since the specimen of Example 1 did not undergo thermal deformation under the condition of PV value 2, it can be confirmed that it is superior to the commercially available low-friction resin in terms of heat resistance.

It was found that this effect can be obtained only when expanded graphite and fluororesin are used as fillers at the same time. Looking at Comparative Examples 3 to 5, when only expanded graphite is used, the wear rate is excellent, but the friction characteristics are remarkably deteriorated, and when general graphite other than the expanded graphite is mixed with a fluororesin, both the friction characteristics and the wear rate are decreased. I can confirm.

As described above, since the coefficient of friction of the specimen of Example 1 was lower than that of Comparative Examples 1 to 5, it was found that heat generation due to friction was less. When the change of the friction material was observed after the friction coefficient and the wear rate measurement test, there was almost no change in the material to be rubbed after the test of the specimen in Example 1, but thermal oxidation occurred when the material to be rubbed after the experiment of Comparative Examples 1 to 5 was observed. I could see traces of deformation.

Claims (15)

Phthalonitrile compounds;
Hardener; And
Containing, a low-friction polymerizable composition; a filler including expanded graphite and a fluororesin.
The method of claim 1,
The content of the filler is 1 to 50% by weight based on 100% by weight of the composition, low friction polymerizable composition.
The method of claim 1,
The expanded graphite has a density of 1.5 g/cm 3 or less, a low friction polymerizable composition.
The method of claim 1,
The expanded graphite has a BET specific surface area of 5 to 100 m ² /g, a low friction polymerizable composition.
The method of claim 1,
The fluororesin is polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene- A low-friction polymerizable composition, which is at least one selected from the group consisting of fluoroalkylvinylether-fluoroolefin copolymer, ethylene-trichlorofluoroethylene copolymer, and polyvinylidene fluoride.
The method of claim 1,
The filler comprises expanded graphite and a fluororesin in a weight ratio of 1:10 to 10:1, a low-friction polymerizable composition.
The method of claim 1,
The curing agent is at least one selected from the group consisting of an amine compound, a hydroxy compound, an imide compound, an inorganic acid compound and an organic acid compound, a low friction polymerizable composition.
The method of claim 7,
The curing agent is an imide-based compound represented by the following formula (1), a low-friction polymerizable composition:
[Formula 1]

In Formula 1,
M is a tetravalent radical derived from an aliphatic, alicyclic or aromatic compound,
X ₁ and X ₂ are each independently an alkylene group, an alkylidene group, or a divalent radical derived from an aromatic compound,
n is a number of 1 or more.
The method of claim 8,
In Formula 1,
M is a tetravalent radical derived from an alkane, alkene, or alkyne, or a tetravalent radical derived from a compound represented by any one of the following formulas 2 to 7
[Formula 2]

In Chemical Formula 2,
R ₁ to R ₆ are each independently hydrogen, an alkyl group, an alkoxy group, or an aryl group,
[Formula 3]

In Chemical Formula 3,
R ₁ to R ₈ are each independently hydrogen, an alkyl group, an alkoxy group, or an aryl group,
[Formula 4]

In Chemical Formula 4,
R ₁ to R ₁₀ are each independently hydrogen, an alkyl group, an alkoxy group, or an aryl group,
X is a single bond, an alkylene group, an alkylidene group, -O-, -S-, -C(=O)-, -S(=O)-, -S(=O) ₂ -, -C(=O )-OL ₁ -OC(=O)-, -L ₂ -C(=O)-OL ₃ -, -L ₄ -OC(=O)-L ₅ -, or -L ₆ -Ar ₁ -L ₇ -Ar ₂ -L ₈ -, wherein L ₁ to L ₈ are each independently a single bond, -O-, an alkylene group, or an alkylidene group, and Ar ₁ and Ar ₂ are each independently an arylene group,
[Formula 5]

In Chemical Formula 5,
R ₁ to R ₄ are each independently hydrogen, an alkyl group, or an alkoxy group, but two of R ₁ to R ₄ may be connected to each other to form an alkylene group,
A is an alkylene group or alkenylene group, but the alkylene group or alkenylene group of A may contain one or more oxygen atoms as a hetero atom,
[Formula 6]

In Formula 6,
R ₁ to R ₄ are each independently hydrogen, an alkyl group, or an alkoxy group,
A is an alkylene group,
[Formula 7]

In Chemical Formula 7,
Each of R ₁ to R ₁₀ is independently hydrogen, an alkyl group, or an alkoxy group.
The method of claim 8,
In Formula 1,
X ₁ and X ₂ are each independently a divalent radical derived from an aromatic compound having 6 to 40 carbon atoms, a low-friction polymerizable composition.
The method of claim 10,
In Formula 1,
X ₁ and X ₂ are each independently, a divalent radical derived from a compound represented by any one of the following Formulas 8 to 10, a low-friction polymerizable composition:
[Formula 8]

In Chemical Formula 8,
R ₁₁ to R ₁₆ are each independently hydrogen, an alkyl group, an alkoxy group, an aryl group, a hydroxy group, or a carboxyl group,
[Formula 9]

In Formula 9,
R ₁₁ to R ₂₀ are each independently hydrogen, an alkyl group, an alkoxy group, an aryl group, a hydroxy group, or a carboxyl group,
X'is a single bond, an alkylene group, an alkylidene group, -O-, -S-, -C(=O)-, -NR ₂₁ -, -S(=O)-, -S(=O) _2- , -L ₉ -Ar ₃ -L ₁₀ -or -L ₁₁ -Ar ₄ -L ₁₂ -Ar ₅ -L ₁₃ -, wherein R ₂₁ is hydrogen, an alkyl group, an alkoxy group, or an aryl group, and L ₉ to L ₁₃ is each independently a single bond, -O-, an alkylene group, or an alkylidene group, Ar ₃ to Ar ₅ are each independently an arylene group,
[Formula 10]

In Chemical Formula 10,
R ₁₁ to R ₂₀ are each independently hydrogen, an alkyl group, an alkoxy group, an aryl group, a hydroxy group, or a carboxyl group.
The method of claim 8,
In Formula 1,
n is a number in the range of 2 to 200, the low friction polymerizable composition.
The method of claim 8,
The compound represented by Formula 1 has a decomposition temperature of 300°C or higher, a low-friction polymerizable composition.
A prepolymer which is a reactant of the low friction polymerizable composition of claim 1.
A high-speed rotating part manufactured by using the low friction polymerizable composition of claim 1 or the prepolymer of claim 14.

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