JPH11116684A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition which is excellent in solvent resistance and chemical resistance, has low moisture permeability, has low surface energy, and gives a cured product having excellent releasability and water repellency. Get. SOLUTION: (A) a fluorine-containing amide compound of the formula (1), (B) a perfluoroalkyl ether group in a molecule,
A curable composition comprising a fluorine-containing organohydrogensiloxane having a perfluoroalkyl group or a perfluoroalkylene group and a hydrosilyl group, and (C) a platinum group metal-based catalyst. Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable composition which is easily cured by being left or heated at room temperature, and which gives a cured product which is excellent in heat resistance, solvent resistance and chemical resistance and also has excellent low temperature properties. Composition.

[0002]

2. Description of the Related Art
It has been desired to develop a rubber material which is excellent in heat resistance, chemical resistance, solvent resistance and low-temperature characteristics, and has low moisture permeability and can be liquefied.
However, conventional fluororubber is inferior in low-temperature characteristics and cannot be liquefied, and silicone rubber is a material having poor chemical resistance and solvent resistance. In addition, fluorosilicone rubber developed as a rubber material that combines the performance of both,
The chemical resistance and the solvent resistance to polar solvents were insufficient.

Further, a rubber material having the above characteristics has been proposed as a "curable composition" in Japanese Patent Application Laid-Open No. Hei 8-199070, but recently it has been further desired to maintain rubber elasticity at low temperatures. As a result, applications in which this composition is not sufficient are increasing.

[0004] Under these circumstances, it has been desired to develop a curable composition which is excellent in heat resistance, solvent resistance and chemical resistance, and which gives a cured product having particularly excellent low-temperature properties.

[0005]

Means for Solving the Problems and Embodiments of the Invention The present inventors have conducted intensive studies to meet the above-mentioned demands, and as a result, (A) a fluorine-containing amide compound represented by the following general formula (1) (B) ) Fluorine-containing organohydrogen having one or more monovalent or divalent perfluoroalkyl ether group, monovalent perfluoroalkyl group or divalent perfluoroalkylene group in one molecule and having two or more hydrosilyl groups Siloxane: An amount in which the amount of SiH groups is 0.5 to 5 mol per 1 mol of the aliphatic unsaturated group contained in the composition. (C) A curable composition containing a catalytic amount of a platinum group metal-based catalyst. However, they have been found that they are easily cured when left or heated at room temperature, and give cured products excellent in heat resistance, solvent resistance, chemical resistance and low-temperature properties.

[0006]

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That is, the present inventor has found that the structural units of the divalent perfluoropolyether Rf contained in the fluorinated amide compound of the above general formula (1) are represented by the above general formulas (4a) to (4
When a polymer having a unit represented by c), particularly a unit having a side chain of a perfluoroalkyl group having 3 or more carbon atoms of (4c), a low-temperature property of a curable composition to be obtained can be extremely effectively improved. And completed the present invention.

Accordingly, the present invention relates to (A) a fluorine-containing amide compound represented by the above general formula (1), and (B) one or more monovalent or divalent perfluoroalkyl ether groups or monovalent perfluoroalkyl ether groups per molecule. Fluorine-containing organohydrogensiloxane having a fluoroalkyl group or a divalent perfluoroalkylene group and having two or more hydrosilyl groups: The content of the SiH group is 0.1 to 1 mol of the aliphatic unsaturated group contained in the composition. Provided is a curable composition containing a catalytic amount of a platinum group metal-based catalyst in an amount of 5 to 5 mol (C).

Now, the present invention will be described in further detail. The first component (A) of the curable composition of the present invention is a fluorine-containing amide compound represented by the following general formula (1).

[0010]

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In the above formula (1), R ¹ is a substituted or unsubstituted monovalent hydrocarbon group, preferably having 1 to 12 carbon atoms, especially 1 to 1 carbon atoms.
And alkyl groups such as methyl group, ethyl group, propyl group, and isopropyl group; cycloalkyl groups such as cyclohexyl group; alkenyl groups such as vinyl group and allyl group; and aryl groups such as phenyl group and tolyl group. Or a group in which a hydrogen atom of these groups is partially substituted with a halogen atom or the like, specifically, a 3,3,3-trifluoropropyl group, 6,6,6,5,5,4,4, And a fluorine-substituted alkyl group such as a 3,3-nonafluorohexyl group.

R ² is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. The substituted or unsubstituted monovalent hydrocarbon group preferably has 1 to 12 carbon atoms, especially 1 to 12 carbon atoms.
Those having an alkyl group such as a methyl group, an ethyl group, a propyl group or an isopropyl group; a cycloalkyl group such as a cyclohexyl group; an alkenyl group such as a vinyl group or an allyl group; an aryl group such as a phenyl group or a tolyl group; Alternatively, a group in which a hydrogen atom of these groups is partially substituted with a halogen atom or the like, specifically, 3,3,3-trifluoropropyl, 6,6,6,5,5,4,4,3,3 Examples thereof include a fluorine-substituted alkyl group such as a 3-nonafluorohexyl group.

Q is the following general formula (2) or (3)
Is a group represented by

[0014]

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In the above formula (2), R ³ is a substituted or unsubstituted divalent hydrocarbon which may be mediated by one or more of oxygen, nitrogen and silicon atoms in the carbon-carbon bond. Groups, preferably having 1 to 12 carbon atoms, especially 3 to 10 carbon atoms
belongs to. Examples of the above-mentioned substituted or unsubstituted divalent hydrocarbon group not via an atom include an alkylene group such as a butylene group and a hexamethylene group; a cycloalkylene group such as a cyclohexylene group; an arylene group such as a phenylene group and a tolylene group; And a group in which a hydrogen atom of the group is partially substituted with a halogen atom or the like. Further, as a group containing one or more of an oxygen atom, a nitrogen atom and a silicon atom in the bond, the oxygen atom is -O-, the nitrogen atom is -NR'- (R 'is a hydrogen atom or carbon atom). Number 1
8, especially 1 to 6 alkyl or aryl groups. )
The silicon atom is preferably interposed as the following group.

[0016]

Embedded image (In the formula, R ″ is an alkyl group or an aryl group having 1 to 8 carbon atoms, R ″ ′ is an alkylene group or an arylene group having 1 to 6 carbon atoms, and n is 0 to 10, particularly 0 to 5 It is an integer.) Examples of such an R ³ group include the following groups.

[0017]

Embedded image (Me represents a methyl group.)

In the above formula (3), R ⁴ and R ⁵ are each a substituted or unsubstituted divalent hydrocarbon group, preferably having 1 to 8 carbon atoms, and specifically include an ethylene group and a propylene group. , Butylene, hexamethylene, and other alkylene groups, cyclohexylene and other cycloalkylene groups, and groups in which the hydrogen atoms of these groups have been partially substituted with halogen atoms.

Specific examples of the Q group represented by the formula (2) or (3) include the following groups, which are representative examples, and are not limited thereto. Absent. In the following formula, a methyl group is abbreviated as Me, and a phenyl group is abbreviated as Ph.

[0020]

Embedded image (Rf ′ is the same as Rf described later, or represents a divalent perfluoroalkylene group or a divalent perfluoroalkyl ether group having 2 to 10 carbon atoms.)

[0021]

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In the above formula (1), Rf is the following formula (4)
It is a divalent perfluoropolyether group having the structural units represented by a) to (4c) as essential structural units.

[0023]

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In the structural unit represented by the above formula (4), X is a perfluoroalkyl group having 3 or more carbon atoms, preferably 3 to 8, and b is an integer of 2 to 6.

In this case, the unit of (4a) is 1 in the molecule.
-300, especially 1-200, the unit of (4b) is 1-
It may have 5, especially 1 or 2, and preferably has 1 to 50, particularly 1 to 25 units of (4c).

Specific examples of such a divalent perfluoropolyether group include the following compounds.

[0027]

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The fluorine-containing amide compound of the present invention is obtained, for example, by reacting a compound having an acid fluoride group at both terminals represented by the following general formula (5) and an amine represented by the following general formula (6) with an acid acceptor such as triethylamine. It can be synthesized by reacting in the presence of an agent.

FCO-Rf-COF (5) (Rf is the same as described above.)

[0030]

Embedded image (R ¹ and R ² are the same as above.)

The compound obtained by extending the chain length of the Rf group is obtained by combining a compound having an acid fluoride group at both terminals of the above formula (5) with a compound represented by the following formula (7) in the presence of an acid acceptor. And further reacting with a secondary amine of the formula (6).

HQH (7) (Q is the same as described above.)

In the above reaction, the charged amount of the compound of the formula (5) and the compound of the formula (7) must be larger than the charged amount of the compound of the formula (5) in terms of mol. By increasing the ratio of (5) to (7) (5) / (7),
A polymer having a relatively small molecular weight can be synthesized, and (5) /
If the value of (7) approaches 1, a polymer having a large molecular weight can be synthesized.

The reaction is carried out at a temperature of from 20 to 100 ° C., in particular from 20 to 100 ° C.
It is preferable to carry out at 50 ° C.

In the fluorine-containing amide compound of the formula (1), the fluorine-containing organosilicon compound containing silicon in the R ³ group is represented by the following general formula (5) synthesized by the reaction of (5) and (6). It can be synthesized by reacting a compound having vinyl groups at both ends represented by 8) with a compound represented by the following general formula (9) in the presence of an addition reaction catalyst.

[0036]

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In the above reaction, the charged amount of the formulas (8) and (9) must be larger than the charged amount of the formula (8) in terms of mol, but the value is 2 at the maximum. is there. That is, 1 <molar amount of formula (8) / molar amount of formula (9) ≦ 2. Note that the ratio of (8) and (9),
When (8) / (9) is increased, a polymer having a relatively small molecular weight is synthesized. However, when the value of (8) / (9) is close to 1, a polymer having a large molecular weight can be synthesized.

Further, as the addition reaction catalyst, V.V.
Group II elements or compounds thereof, for example, chloroplatinic acid, alcohol-modified chloroplatinic acid (see U.S. Pat. No. 3,220,972), and complexes of chloroplatinic acid with olefins (U.S. Pat. Nos. 3,159,601, 3,159,662 and 3,775,452) ), Platinum black or palladium supported on a carrier such as alumina, silica, carbon, etc., rhodium-olefin complex, chlorotris (triphenylphosphine) rhodium (Wilkinson catalyst), and the like. It is preferably dissolved in a solvent of a solvent, ketone, ether or hydrocarbon. The amount of the catalyst used can be a usual amount.

This reaction is carried out at 50 to 150 ° C., preferably at 8 ° C.
What is necessary is just to carry out at 0-120 degreeC.

The fluorine-containing amide compound (A) can be used in the present invention from a low-viscosity polymer of several tens of cSt (25 ° C.) to a solid rubber-like polymer. From the viewpoint of ease of handling, for example, a raw rubber-like polymer is used for hot vulcanized rubber, and 100 to 100,000 is used for liquid rubber.
Polymers of the order of cSt (25 ° C.) are suitable. If the viscosity is too low, the obtained cured product may have low elongation as an elastomer, and may not have balanced physical properties.

The fluorine-containing organohydrogensiloxane (B) as the second component constituting the composition of the present invention functions as a cross-linking agent and a chain extender, and one or more components per molecule. It has a monovalent or divalent perfluoroalkyl ether group, a monovalent perfluoroalkyl group or a divalent perfluoroalkylene group, and has two or more hydrosilyl groups (SiH groups). These groups preferably have 1 to 50, particularly 1 to 25 carbon atoms.

Examples of the fluorine-containing organohydrogensiloxane of the component (B) include the following. These compounds may be used alone or in combination.

[0043]

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[0044]

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The cross-linking agent as the second component is preferably one that is compatible with the first component in order to obtain a uniform cured product.

The amount of the component (B) relative to the component (A) is 0.1 to 5 parts by weight based on 100 parts by weight of the first component.
0 parts by weight, in particular 1 to 10 parts by weight, but in practice, 1 mole of an aliphatic unsaturated hydrocarbon group such as a vinyl group, an allyl group or a cycloalkenyl group contained in the whole composition. 0.5 to 5 mol, especially 1 to 2 mol
A molar supply is preferred. SiH group supply amount is 0.5
If the amount is less than 5 moles, the degree of crosslinking may be insufficient. If the amount is more than 5 moles, the chain length is prioritized and curing is insufficient, foaming, heat resistance, compression set properties, etc. are deteriorated. In some cases.

The platinum group metal-based catalyst as the component (C) constituting the composition of the present invention functions as a catalyst for promoting the addition reaction (hydrosilylation) between the components (A) and (B). . In this case, as the platinum group metal-based catalyst,
In general, since a compound of a noble metal is expensive, a platinum compound which is relatively easily available, for example, chloroplatinic acid or a complex of chloroplatinic acid with an olefin such as ethylene, a complex of an alcohol or vinylsiloxane, platinum / silica, alumina Alternatively, a solid catalyst such as carbon can be used, but in order to obtain a more uniform cured product, a solution obtained by dissolving chloroplatinic acid or a complex in an appropriate solvent is used after being compatible with the first component. Is good. In the present invention, for example, rhodium, ruthenium, iridium, palladium compounds and the like can be used as an addition reaction catalyst other than the above platinum compound. Specifically, RhCl (PPh ₃ ) ₃ , RhCl (CO) (PP
_{h 3) 2, RhCl (C} 2 H 4) 2, Ru 3 (CO) 12, Ir
Cl (CO) (PPh ₃ ) ₂ and Pd (PPh ₃ ) ₄ are exemplified.

The amount of use of these catalysts is not particularly limited, but may be expensive, so that the amount of the metal such as platinum can be generally 1 to 1000 ppm, particularly about 10 to 500 ppm.

In putting the composition of the present invention into practical use, various additives may be further added as necessary. Specifically, CH ₂ = added for the purpose of controlling the curing rate of the composition
CH (R) SiO units (wherein, R is a is same groups as the R ²⁾ polysiloxanes containing (JP-B 48-1094
No. 7) and an acetylene compound (US Pat. No. 34).
No. 45420 and Japanese Patent Publication No. 54-3774).
Heavy metal ionic compounds (see US Pat. No. 3,532,649).

When these additives are added,
Also, a hydrogen atom (S) directly bonded to a silicon atom per mole of an aliphatic unsaturated hydrocarbon group of the total amount of alkenyl groups and ethynyl groups directly bonded to silicon atoms in the entire composition (S
(iH group) is preferably in the range of 0.5 to 5 mol.

Further, the composition of the present invention may have a reduced thermal shrinkage during curing, a reduced thermal expansion coefficient of an elastic body obtained by curing, a thermal stability, weather resistance, chemical resistance, flame retardancy or the like. Fillers may be added for the purpose of improving mechanical strength or reducing gas permeability, such as fumed silica, quartz powder, glass fiber, carbon, iron oxide, titanium oxide, cerium oxide, and other metals. Oxides, calcium carbonate, metal carbonates such as magnesium carbonate and the like,
It is also possible to add suitable pigments, dyes or antioxidants to this, if necessary. In addition, the addition amount of these optional components can be a usual amount as long as the effect of the present invention is not hindered.

The composition of the present invention can be cured at room temperature depending on the type of the functional group of the component (A) and the type of the catalyst of the component (C), but it is heated to 100 to 150 ° C. for several minutes to several hours. It is also possible to cure in a short time.

In practical use of the composition of the present invention, use,
Depending on the purpose, the composition may be dissolved in a desired concentration in a suitable fluorinated solvent, for example, meta-xylene hexafluoride or florinate, and used.

[0054]

The curable composition of the present invention is excellent in low-temperature properties, high in fluorine content, excellent in solvent resistance and chemical resistance, low in moisture permeability and low in surface energy. It has excellent release properties and water repellency, and rubber materials for automobiles, tent film materials, sealants, molded parts, extruded parts, coating materials, coating materials, copier roll materials, electric moisture-proof coating materials, sensors that require oil resistance are required. It can be used effectively for potting materials and the like.

[0055]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Example 1 A polymer represented by the following formula (10) (viscosity: 5900 cs, weight average molecular weight: 1700)
0, vinyl group amount 0.012 mol / 100 g) 100 m parts by weight treated with dimethylsiloxy group, specific surface area 200 m
20 parts by weight of ² / g fumed silica were added, mixed, heat-treated, and then mixed on a three-roll mill.
3.29 parts by weight of the fluorinated cyclic hydrogen siloxane represented by 1) and chloroplatinic acid were converted to CH ₂ ＣＨCHSiMe ₂ OSiMe ₂
0.2 parts by weight of a toluene solution of a catalyst modified with CH = CH ₂ (platinum concentration: 1.0% by weight) and 0.4 parts by weight of a 50% toluene solution of ethynylcyclohexanol were added and mixed. Created.

[0057]

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The obtained composition I was defoamed under reduced pressure,
Put it in a rectangular frame of thickness m, bleed it again,
Press hardening was performed at 150 ° C. for 10 minutes at g / cm ² . The test piece was cut out from the cured sample, and the physical properties were measured according to JIS K6301, and the following results were obtained. Hardness (JIS-A *) 57 Elongation (%) 290 Tensile strength (kgf / cm ² ) 70 (* Note: Measured using an A-type spring hardness tester specified in JIS K6301, and so on.) Next, using this test piece, heat resistance, chemical resistance, solvent swellability, low-temperature characteristics, and moisture permeability were measured by the following methods, and the results shown in Tables 1 to 5 were obtained.

Comparative Example A polymer represented by the following formula (12) (having a viscosity of 5000) was used instead of the polymer represented by the formula (10).
cs, weight average molecular weight 15,300, vinyl group content 0.01
Composition II was prepared in the same manner as in Example 1 except that 3 mol / 100 g) and 3.66 parts by weight of the fluorinated cyclic hydrogen siloxane used in Example 1.

[0060]

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A cured sheet was prepared from the composition II under the same conditions as in Example 1. Cut out the test piece and use JIS K6
As a result of measuring physical properties according to No. 301, the following results were obtained. Hardness (JIS-A *) 54 Elongation (%) 310 Tensile strength (kgf / cm ² ) 71 Next, when the low-temperature characteristics were measured using this test piece, the results shown in Table 4 were obtained.

[0062]

[Table 1]

[0063]

[Table 2]

[0064]

[Table 3]

[0065]

[Table 4]

[0066]

[Table 5]

Example 2 The formula (1) used in Example 1 was used.
Polymer represented by the following formula (13) (viscosity 21,000 cs, weight average molecular weight 170
A composition was prepared in the same manner as in Example 1 except that 100 parts by weight of the vinyl group was used and 3.29 parts by weight of the fluorinated cyclic hydrogen siloxane used in Example 1 was used. Then, a cured sheet was prepared.

[0068]

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A test piece was cut out, and its physical properties were measured in accordance with JIS K6301, and the following results were obtained. Hardness (JIS-A) 60 Elongation (%) 250 Tensile strength (kgf / cm ² ) 73

Example 3 The formula (1) used in Example 1 was used.
Polymer represented by the following formula (14) (viscosity: 136000 cs, weight average molecular weight: 23)
300, vinyl group content 0.008 mol / 100g) 100
A composition was prepared in the same manner as in Example 1 except that 2.3 parts by weight of the fluorine-containing cyclic hydrogen siloxane used in Example 1 was used, and a cured sheet was prepared.

[0071]

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The test piece was cut out, and the physical properties were measured according to JIS K6301, and the following results were obtained. Hardness (JIS-A) 47 Elongation (%) 390 Tensile strength (kgf / cm ² ) 59

Example 4 The formula (1) used in Example 1 was used.
Polymer represented by the following formula (15) (viscosity 87000 cs, weight average molecular weight 279) instead of the polymer 0)
A composition was prepared in the same manner as in Example 1 except that 100 parts by weight of the fluorinated cyclic hydrogen siloxane used in Example 1 was used, and 100 parts by weight of the vinyl group (0.007 mol / 100 g) were used. Then, a cured sheet was prepared.

[0074]

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A test piece was cut out, and the physical properties were measured according to JIS K6301, and the following results were obtained. Hardness (Jls-A) 54 Elongation (%) 390 Tensile strength (kgf / cm ² ) 49

Example 5 The formula (1) used in Example 1
A composition was prepared in the same manner as in Example 1 except that 3.29 parts by weight of a hydrogen siloxane represented by the following formula (16) was used instead of the fluorinated cyclic hydrogen siloxane of 1), to prepare a cured sheet.

[0077]

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A test piece was cut out, and its physical properties were measured in accordance with JIS K6301, and the following results were obtained. Hardness (JIS-A) 52 Elongation (%) 310 Tensile strength (kgf / cm ² ) 73

Claims (1)

[Claims] (A) A fluorine-containing amide compound represented by the following general formula (1): (B) a fluorine-containing compound having one or more monovalent or divalent perfluoroalkyl ether group, monovalent perfluoroalkyl group or divalent perfluoroalkylene group in one molecule and having two or more hydrosilyl groups; Organohydrogensiloxane: an amount of 0.5 to 5 moles of SiH groups per mole of aliphatic unsaturated groups contained in the composition. (C) A catalyst amount containing a platinum group metal-based catalyst. Characteristic curable composition.