JP7434879B2 - Elastomer member and method for manufacturing elastomer member - Google Patents

Description

The present invention relates to an elastomer member and a method for manufacturing an elastomer member.

Until now, various developments have been made regarding the use of silicone rubber in sliding members. As this type of technology, for example, the technology described in Patent Document 1 is known. Patent Document 1 describes that the flexible inner portion that slides in the catheter tube is made of silicone rubber (claims 3 and 5).

Special table 2018-501058 publication

However, as a result of studies conducted by the present inventor, it has been found that there is room for improvement in terms of sliding properties and mechanical property fluctuations in the member using the silicone rubber described in Patent Document 1.

Generally speaking, the surface of a silicone rubber layer containing silicone rubber may have tack. One of the reasons for this is thought to be that the raw material components constituting the silicone rubber bleed onto the surface.
A silicone rubber layer with a tacky surface has poor slip properties. For this reason, a measure is usually taken to coat the surface with a silicone-based surface treatment agent (liquid silicone rubber).

However, upon further investigation, the present inventor found that the mechanical properties (rubber properties) of a silicone rubber layer whose surface is coated with a silicone-based surface treatment agent vary.
Based on these findings, we conducted further intensive research and found that by applying appropriate surface treatments such as parylene coating, coupling agent treatment, and surface activation treatment, it was possible to improve slipperiness while minimizing mechanical property fluctuations. The present inventors have discovered that it is possible to realize a silicone rubber layer that is suppressed, and have completed the present invention.

According to the invention,
An elastomeric member comprising a silicone rubber layer,
The surface of the silicone rubber layer is subjected to one or more surface treatments selected from the group consisting of parylene coating treatment, coupling agent treatment, and surface activation treatment,
The tack peak value obtained according to the following procedure is 5.0N or less,
An elastomeric member is provided.
(procedure)
An aluminum probe having a flat surface with an area of 150 mm ² was used as a measurement sample under the conditions of probe moving speed: 2.3 mm/sec, probe crimping strength: 12 N, and crimping time: 6 seconds. The tack peak value on the surface of the elastomer member in the probe tack test when the elastomer member is brought into contact with the surface-treated surface and peeled upward at a probe moving speed of 2.3 mm/sec is 5. The measurement was carried out twice, and the average value of the five measurements was taken as the above tack peak value.

Further, according to the present invention,
a molding process of molding a silicone rubber layer;
a surface treatment step of subjecting the surface of the silicone rubber layer to one or more surface treatments selected from the group consisting of parylene coating treatment, coupling agent treatment, and surface activation treatment;
A method for manufacturing an elastomer member comprising a silicone rubber layer, the method comprising:
The molding step and the surface treatment step are performed in-line.
A method of manufacturing an elastomeric member is provided.

According to the present invention, an elastomer member with excellent slip properties and suppressed variations in mechanical properties, and a method for manufacturing the same are provided.

FIG. 2 is a cross-sectional view showing an example of the configuration of an elastomer member according to the present embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that in all the drawings, similar components are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate. Furthermore, the figure is a schematic diagram and does not correspond to the actual dimensional ratio.

The elastomer member of this embodiment will be outlined.

The elastomer member of this embodiment includes a silicone rubber layer.
In the elastomer member, the surface of the silicone rubber layer is subjected to one or more surface treatments selected from the group consisting of parylene coating treatment, coupling agent treatment, and surface activation treatment.
This elastomer member has a characteristic that the tack peak value obtained according to the following procedure is 5.0 N or less.
(procedure)
An aluminum probe having a flat surface with an area of 150 mm ² was used as a measurement sample under the conditions of probe moving speed: 2.3 mm/sec, probe crimping strength: 12 N, and crimping time: 6 seconds. The tack peak value on the surface of the elastomer member in a probe tack test when the elastomer member is brought into contact with the surface-treated surface and peeled upward at a probe moving speed of 2.3 mm/sec is 5. The measurement was carried out twice, and the average value of the five measurements was taken as the above tack peak value.

According to the findings of the present inventors, large variations occur in the mechanical properties (rubber properties) of a silicone rubber layer whose surface is coated with a silicone-based surface treatment agent, but parylene coating treatment, coupling agent treatment, and It has been discovered that by applying one or more appropriate surface treatments selected from the group consisting of surface activation treatments, it is possible to realize a silicone rubber layer that has improved slipperiness while suppressing fluctuations in mechanical properties. As one specific example, variations in standard deviation of rubber properties such as tensile strength and elongation at break can be suppressed. For this reason, it is possible to relatively reduce variations between lots and variations during repeated manufacturing in terms of rubber properties.

It has been found that the physical properties of the silicone rubber layer are affected by the way in which a coating agent such as a silicone surface treatment agent is applied. Although the detailed mechanism is not clear, it is thought that if there is variation in the thickness or film components of the coating agent layer in the in-plane direction, the variation in the rubber properties of the silicone rubber layer increases.
On the other hand, parylene and a coupling agent chemically bond to the surface, and plasma treatment, which is one type of surface activation treatment, modifies the surface, and then the surface-treated surface is cleaned. Surface treatment layers with small variations in composition and thickness in the in-plane direction are formed, such as single layers such as parylene layers and coupling agent layers (silane layers), and modified layers such as plasma treatment layers near the surface. It is thought that variations in the rubber properties of the silicone rubber layer are suppressed compared to the coating agent.
Furthermore, by the above-mentioned surface treatment, the surface of the silicone rubber layer, which had tack, can be suppressed from tack to a predetermined tack value or less. Therefore, the slipperiness of the silicone rubber layer can be improved.

According to this embodiment, it is possible to realize an elastomer member having a silicone rubber layer that has excellent slip properties and suppresses fluctuations in mechanical properties.

The elastomer member of this embodiment can be used for various purposes, such as medical equipment such as rubber tubes and gaskets, structural members for automobiles and construction, sliding members thereof, or cushioning materials during molding. It can be suitably used as, etc. Further, the form of the elastomer member is not particularly limited, and may have a sheet shape, a cylindrical shape, or a predetermined shape.

FIG. 1 is a cross-sectional view showing an example of the configuration of an elastomer member 100 according to the present embodiment.
The elastomer member 100 has at least a silicone rubber layer 10 and a surface treatment layer 20 provided on the surface of the silicone rubber layer 10. The silicone rubber layer 10 and the surface treatment layer 20 may be chemically bonded to each other.
The silicone rubber layer 10 in the elastomeric member 100 may be provided on a substrate.
The base material is not particularly limited, but may be made of an inorganic material such as metal, an organic material such as resin, or a composite material thereof.

Hereinafter, the structure of the elastomer member of this embodiment will be explained in detail.

The elastomer member has a surface treatment layer.
The surface treatment layer can be formed by subjecting the surface of the silicone rubber layer to one or more surface treatments selected from the group consisting of parylene coating treatment, coupling agent treatment, and plasma treatment.
These may be used alone or in combination of two or more.

(Parylene coat treatment)
The parylene coating process includes a step of depositing parylene on the surface of silicone rubber by a vapor phase deposition method.
By the parylene coating treatment, a parylene layer can be formed on the surface of the silicone rubber layer.

Parylene is the general name applied to the group of unsubstituted and substituted poly-p-xylylenes. The polymer may be a homopolymer or a copolymer, depending on whether it is derived from one particular dimer or a mixture of different dimers.

The substituent can be any organic or inorganic group that can normally be substituted on an aromatic nucleus. Examples of organic substituents are alkyl, aryl, alkenyl, cyano, carboxyl, alkoxy, hydroxyalkyl, and carbalkoxy, and examples of inorganic substituents are hydroxyl, nitro, halogen and amino. Generally, the selected substituents are functionally inert under the reaction conditions. Preferred among the substituents are lower alkyl having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, butyl and hexyl; lower alkyl having 1 or 2 benzene rings, such as phenyl and naphthyl. aryl hydrocarbons and alkylated phenyls and naphthyls having 1 to 10 carbon atoms in the alkyl position; and halogens such as chlorine, bromine, iodine and fluorine.

An example of parylene is not particularly limited and can be appropriately selected depending on the purpose, such as parylene N, parylene C, parylene D, parylene HT, and the like.
Parylene N has a structure represented by the following chemical formula (a), Parylene C has a structure represented by the following chemical formula (b), and Parylene D has a structure represented by the following chemical formula (c). It has a structure that is

The vapor phase deposition method can be performed by a known method. For example, using a parylene vapor deposition apparatus, a predetermined amount of parylene dimer can be sublimed and deposited within the vacuum evaporator of the apparatus.

The thickness of the parylene layer in the film thickness direction is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01 μm to 50 μm, 0.1 μm to 10 μm, and more preferably 1 μm to 5 μm. By setting it to the above lower limit or more, the slipperiness and bleed resistance of the silicone rubber layer can be improved. By setting it below the above upper limit, fluctuations in the mechanical properties of the silicone rubber layer can be suppressed.

(Coupling agent treatment)
The coupling agent treatment includes a step of applying a silane coupling agent to the surface of the silicone rubber.
By the coupling agent treatment, a coupling agent treatment layer, specifically a silane layer, can be formed on the surface of the silicone rubber layer.

Examples of the silane coupling agent include vinyltrimethoxysilane and vinyltriethoxysilane having a vinyl group; 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 3-glycidoxypropylmethyldimethoxysilane having an epoxy group; Silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane; p-styryltrimethoxysilane with styryl group; 3-glycidoxypropyltrimethoxysilane with methacryl group Methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane and 3-methacryloxypropyltriethoxysilane; 3-acryloxypropyltrimethoxysilane having an acrylic group; amino group N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxy Silane, 3-ethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltri Methoxysilane hydrochloride; 3-ureidopropyltriethoxysilane having a ureido group; 3-mercaptopropylmethyldimethoxysilane having a mercapto group; Bis(triethoxysilylpropyl)tetrasulfide having a sulfide group; 3-isocyanate having an isocyanate group Mention may be made of propyltriethoxysilane. These silanes may be used alone or in combination of two or more.

The silane coupling agent may be used after being diluted with a solvent, or may be used without being diluted.
Examples of the solvent include water, alcohol, acetic acid, a mixture of two or more thereof, and organic solvents such as tetrahydrofuran (THF), toluene, and hexane.

The concentration of silane in the diluted solution containing the silane coupling agent is not particularly limited, but is, for example, 5% to 90% by weight, preferably 10 to 50% by weight. By setting it to the above lower limit or more, the slipperiness and bleed resistance of the silicone rubber layer can be improved. By setting it below the above upper limit, fluctuations in the mechanical properties of the silicone rubber layer can be suppressed.

Application of the silane coupling agent is not particularly limited, but in addition to using a brush, spray, or roller, there are also methods such as applying the surface of the silicone rubber layer to a solution of the silane coupling agent, or immersing the entire silicone rubber layer. used.

(Surface activation treatment)
Examples of the surface activation treatment include plasma treatment, corona treatment, and ultraviolet treatment. These may be used alone or in combination of two or more. Among these, plasma treatment is preferred.

Plasma treatment breaks the chemical bonds of molecules on the surface of the silicone rubber layer using ions and electrons released by electric discharge, and depending on the type of silicone rubber, hydrophilic functional groups such as OH (hydroxyl group) and CO (carbonyl group) are removed. )・COOH (carboxyl group), etc.
By plasma treatment, a hydrophilically modified layer can be formed on the surface of the silicone rubber layer.

In plasma processing, the atmosphere, power, and processing time can be appropriately set.

As an example of plasma treatment, oxygen plasma treatment, atmospheric plasma treatment, plasma polymerization treatment, etc. may be used.

Oxygen plasma treatment is a method of plasma treatment in an oxygen-containing gas atmosphere. The treatment may be performed under low pressure by evacuation, or the treatment may be performed under a mixed gas atmosphere containing a rare gas such as argon.
For example, the pressure inside the apparatus may be 1 to 5 Pa, the output may be 50 to 1000 W, and the processing time may be 1 to 15 minutes.

Atmospheric plasma processing is a method of plasma processing in an atmosphere of argon, helium, krypton, neon, xenon, nitrogen, or a mixture of two or more of these rare gases.

Plasma polymerization treatment is a method of plasma treatment in a mixed gas atmosphere of hydrocarbon gas and oxygen-containing gas. The treatment may be carried out under a mixed gas atmosphere of methane and oxygen.

The elastomeric member has a silicone rubber layer.

The upper limit of the tack peak value TP on the surface of the silicone rubber layer is, for example, 6.0N or less, preferably 3.0N or less, and more preferably 1.0N or less. By setting it to 6.0 N or less, the slipperiness can be improved to an extent that causes no practical problems. Further, by setting the value to 1.0 or less, good sliding properties can be achieved even when the contact target is repeatedly contacted and the contact speed is high. On the other hand, the lower limit of the tack peak value TP is not particularly limited, but may be, for example, more than 0N, or more than 0.1N.

The procedure for measuring the tack peak value TP is as follows.
An aluminum probe having a flat surface with an area of 150 mm ² was used as a measurement sample under the conditions of probe moving speed: 2.3 mm/sec, probe crimping strength: 12 N, and crimping time: 6 seconds. The tack peak value on the surface of the silicone rubber layer was measured five times by a probe tack test when the silicone rubber layer was brought into contact with the surface and peeled upward at a probe moving speed of 2.3 mm/sec. The average value of these five measurements is taken as the above-mentioned tack peak value TP.

The lower limit of the tensile strength of the surface-treated silicone rubber layer measured in accordance with JIS K6251 (2004) is, for example, 6.0 MPa or more, preferably 7.0 MPa or more, and more Preferably it is 8.0 MPa or more. Thereby, the mechanical strength of the elastomer member can be improved. Moreover, the breaking energy can be increased. Therefore, it is possible to realize an elastomer member with excellent durability that can withstand repeated deformation. On the other hand, the upper limit of the tensile strength of the silicone rubber layer is not particularly limited, but may be, for example, 15 MPa or less, or 13 MPa or less. Thereby, the operability of the elastomer member can be improved.

The upper limit of durometer hardness A defined in accordance with JIS K6253 (1997) of the surface-treated silicone rubber layer is, for example, 90 or less, preferably 85 or less, and more preferably 80. It is as follows. As a result, it has flexibility as an elastomer member and can improve followability to other members. The lower limit of the durometer hardness A of the silicone rubber layer may be, for example, 30 or more, 40 or more, or 50 or more. Thereby, the mechanical strength of the elastomer member can be increased.

The lower limit of the tear strength of the surface-treated silicone rubber layer measured in accordance with JIS K6252 (2001) is, for example, 25 N/mm or more, preferably 30 N/mm or more, and more Preferably it is 33 N/mm or more, more preferably 35 N/mm or more. Thereby, the scratch resistance and mechanical strength of the elastomer member can be improved. Furthermore, the durability of the elastomer member during repeated use can be improved. On the other hand, the upper limit of the tear strength of the silicone rubber layer is not particularly limited, but may be, for example, 70 N/mm or less, or 60 N/mm or less. This allows the various properties of the silicone rubber layer to be balanced.

The lower limit of the elongation at break of the surface-treated silicone rubber layer measured in accordance with JIS K6251 (2004) is, for example, 200% or more, preferably 300% or more, and more preferably It is 400% or more. Thereby, the elasticity and durability of the elastomer member can be improved. On the other hand, the upper limit of the elongation at break of the silicone rubber layer is not particularly limited, but may be, for example, 1000% or less, 900% or less, or 800% or less. Thereby, the mechanical strength of the elastomer member can be improved.

The upper limit of the tensile stress M ₁₀₀ of the surface-treated silicone rubber layer at 25°C and 100% elongation, measured in accordance with JIS K6251 (2004), is, for example, 8. It may be 0 MPa or less, preferably 6.0 MPa or less, and more preferably 5.0 MPa or less. Thereby, the ease of deformation of the elastomer can be improved. On the other hand, the lower limit of the tensile stress M ₁₀₀ is not particularly limited, but is 1.0 MPa or more, preferably 2.0 MPa or more. Thereby, the mechanical strength of the elastomer can be improved.

The upper limit of the tensile stress M ₃₀₀ of the surface-treated silicone rubber layer at 25° C. and 300% elongation, measured in accordance with JIS K6251 (2004), is, for example, 11. It may be 0 MPa or less, preferably 9.0 MPa or less, and more preferably 8.0 MPa or less. Thereby, the ease of deformation of the elastomer can be improved. On the other hand, the lower limit of the tensile stress M ₃₀₀ is not particularly limited, but is 4.0 MPa or more, preferably 6.0 MPa or more. Thereby, the mechanical strength of the elastomer can be improved.

In this embodiment, for example, the type and amount of each component contained in the silicone rubber layer, the method for preparing the composition for forming the silicone rubber layer, the method for manufacturing the silicone rubber layer, the surface treatment method, etc. are appropriately selected. By doing so, it is possible to control the tack peak value, tensile strength, hardness, tear strength, elongation at break, and tensile stress. Among these, for example, it is necessary to appropriately select one or more surface treatments selected from the group consisting of parylene coating treatment, coupling agent treatment, and plasma treatment, the type and blending ratio of resin constituting the silicone rubber layer, and the resin The above-mentioned tack peak value, tensile strength, hardness, tear strength, elongation at break, etc. can be improved by appropriately controlling the crosslinking density and crosslinking structure of This is mentioned as a factor for adjusting the tensile stress to a desired numerical range.

Next, the composition of the silicone rubber layer according to this embodiment will be explained.

As the elastomer constituting the silicone rubber layer, silicone rubber can be used from the viewpoint of balance of rubber properties, chemical stability, and excellent thermal stability.

The above-mentioned silicone rubber can be composed of a cured product of a silicone rubber-based curable composition.

Further, the elastomer of this embodiment may contain arbitrary components capable of exhibiting various functions. For example, from the viewpoint of increasing mechanical strength, silicone rubber can contain an inorganic filler. As the inorganic filler, known ones can be used, and for example, silica particles can be used.

The silicone rubber curable composition will be explained below.

The silicone rubber-based curable composition of this embodiment can contain a vinyl group-containing organopolysiloxane (A). The vinyl group-containing organopolysiloxane (A) is a polymer that is the main component of the silicone rubber curable composition of this embodiment.

The vinyl group-containing organopolysiloxane (A) may include a vinyl group-containing linear organopolysiloxane (A1) having a linear structure.

The vinyl group-containing linear organopolysiloxane (A1) has a linear structure and contains vinyl groups, and the vinyl groups serve as crosslinking points during curing.

The vinyl group content of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but preferably has two or more vinyl groups in the molecule and is 15 mol% or less. . Thereby, the amount of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1) can be optimized, and a network with each component described below can be reliably formed.
In this specification, "~" indicates that the upper limit value and the lower limit value are included, unless otherwise specified.

In addition, in this specification, the vinyl group content is the mol% of the vinyl group-containing siloxane unit when the total units constituting the vinyl group-containing linear organopolysiloxane (A1) is 100 mol%. . However, it is assumed that there is one vinyl group for one vinyl group-containing siloxane unit.

Further, the degree of polymerization of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is, for example, preferably in the range of about 1,000 to 10,000, more preferably in the range of about 2,000 to 5,000. The degree of polymerization can be determined, for example, as the number average degree of polymerization (or number average molecular weight) in terms of polystyrene in GPC (gel permeation chromatography) using chloroform as a developing solvent.

Further, the specific gravity of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably in the range of about 0.9 to 1.1.

By using a vinyl group-containing linear organopolysiloxane (A1) having a degree of polymerization and specific gravity within the above range, the heat resistance, flame retardance, chemical stability, etc. of the silicone rubber obtained can be improved. It is possible to improve the

The vinyl group-containing linear organopolysiloxane (A1) is particularly preferably one having a structure represented by the following formula (1).

In formula (1), R ¹ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group, butenyl group, and among them, vinyl group is preferred. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

Further, R ² is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group, and butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

Further, R ³ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the aryl group having 1 to 8 carbon atoms include phenyl group.

Further, examples of substituents for R ¹ and R ² in formula (1) include a methyl group and a vinyl group, and examples of substituents for R ³ include a methyl group.

In addition, in Formula (1), a plurality of R ¹ are mutually independent and may be different from each other or may be the same. Furthermore, the same applies to R ² and R ³ .

Further, m and n are the numbers of repeating units constituting the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1), m is an integer of 0 to 2000, and n is 1000 to 10000. is an integer. m is preferably 0 to 1000, and n is preferably 2000 to 5000.

Further, specific structures of the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1) include, for example, those represented by the following formula (1-1).

In formula (1-1), R ¹ and R ² are each independently a methyl group or a vinyl group, and at least one of them is a vinyl group.

The vinyl group-containing linear organopolysiloxane (A1) is a first vinyl group-containing linear organopolysiloxane having two or more vinyl groups in the molecule and having a vinyl group content of 0.4 mol% or less. It may also contain organopolysiloxane (A1-1). The vinyl group content of the first vinyl group-containing linear organopolysiloxane (A1-1) may be 0.1 mol% or less.

Further, the vinyl group-containing linear organopolysiloxane (A1) is a first vinyl group-containing linear organopolysiloxane (A1-1) and a second vinyl group-containing linear organopolysiloxane (A1-1) having a vinyl group content of 0.5 to 15 mol%. It may also contain a vinyl group-containing linear organopolysiloxane (A1-2).

As raw rubber, which is a raw material for silicone rubber, a first vinyl group-containing linear organopolysiloxane (A1-1) and a second vinyl group-containing linear organopolysiloxane (A1-2) having a high vinyl group content are used. ), the vinyl groups can be unevenly distributed, and the crosslink density can be more effectively formed in the crosslinked network of the silicone rubber. As a result, the tear strength of silicone rubber can be increased more effectively.

Specifically, as the vinyl group-containing linear organopolysiloxane (A1), for example, in the above formula (1-1), a unit in which R ¹ is a vinyl group and/or a unit in which R ² is a vinyl group is used. , a first vinyl group-containing linear organopolysiloxane (A1-1) having two or more in the molecule and containing 0.4 mol% or less, and a unit in which R ¹ is a vinyl group and/or R It is preferable to use a second vinyl group-containing linear organopolysiloxane (A1-2) containing 0.5 to 15 mol % of units in which ² is a vinyl group.

Further, the first vinyl group-containing linear organopolysiloxane (A1-1) preferably has a vinyl group content of 0.01 to 0.2 mol%. Further, the second vinyl group-containing linear organopolysiloxane (A1-2) preferably has a vinyl group content of 0.8 to 12 mol%.

Furthermore, when blending the first vinyl group-containing linear organopolysiloxane (A1-1) and the second vinyl group-containing linear organopolysiloxane (A1-2) in combination, (A1-1) The ratio of (A1-2) and (A1-2) is not particularly limited, but for example, the weight ratio of (A1-1):(A1-2) is preferably 50:50 to 95:5, and 80:20 to 90: More preferably, it is 10.

Note that the first and second vinyl group-containing linear organopolysiloxanes (A1-1) and (A1-2) may be used alone or in combination of two or more. good.

The vinyl group-containing organopolysiloxane (A) may also include a vinyl group-containing branched organopolysiloxane (A2) having a branched structure.

<<Organohydrogenpolysiloxane (B)>>
The silicone rubber-based curable composition of this embodiment can contain organohydrogenpolysiloxane (B).
Organohydrogenpolysiloxane (B) is classified into linear organohydrogenpolysiloxane (B1) having a linear structure and branched organohydrogenpolysiloxane (B2) having a branched structure. Either one or both may be included.

The linear organohydrogenpolysiloxane (B1) has a linear structure and a structure in which hydrogen is directly bonded to Si (≡Si-H), and is a vinyl group-containing organopolysiloxane (A). In addition to vinyl groups, it is a polymer that undergoes a hydrosilylation reaction with vinyl groups contained in components blended into a silicone rubber-based curable composition, thereby crosslinking these components.

The molecular weight of the linear organohydrogenpolysiloxane (B1) is not particularly limited, but, for example, the weight average molecular weight is preferably 20,000 or less, more preferably 1,000 or more and 10,000 or less.

The weight average molecular weight of the linear organohydrogenpolysiloxane (B1) can be measured, for example, in terms of polystyrene in GPC (gel permeation chromatography) using chloroform as a developing solvent.

Further, it is generally preferable that the linear organohydrogenpolysiloxane (B1) does not have a vinyl group. Thereby, it is possible to accurately prevent the crosslinking reaction from proceeding within the molecules of the linear organohydrogenpolysiloxane (B1).

As the above linear organohydrogenpolysiloxane (B1), for example, one having a structure represented by the following formula (2) is preferably used.

In formula (2), R ⁴ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a hydrocarbon group combining these, or a hydride group. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group, and butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

Further, R ⁵ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a hydrocarbon group combining these, or a hydride group. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, and propyl group, of which methyl group is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group, and butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

In addition, in formula (2), a plurality of R ⁴ are mutually independent and may be different from each other or may be the same. The same applies to ^R5 . However, at least two or more of the plurality of R ⁴ and R ⁵ are hydride groups.

Further, R ⁶ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the aryl group having 1 to 8 carbon atoms include phenyl group. A plurality of R ⁶ 's are independent from each other and may be different from each other or the same.

In addition, examples of substituents for R ⁴ , R ⁵ , and R ⁶ in formula (2) include a methyl group, a vinyl group, and the like, and a methyl group is preferable from the viewpoint of preventing intramolecular crosslinking reactions.

Furthermore, m and n are the numbers of repeating units constituting the linear organohydrogenpolysiloxane (B1) represented by formula (2), m is an integer of 2 to 150, and n is an integer of 2 to 150. It is. Preferably, m is an integer from 2 to 100, and n is an integer from 2 to 100.

Note that the linear organohydrogenpolysiloxane (B1) may be used alone or in combination of two or more.

Since the branched organohydrogenpolysiloxane (B2) has a branched structure, it forms a region with a high crosslinking density, and is a component that greatly contributes to the formation of a dense and dense crosslinking structure in the silicone rubber system. In addition, like the above linear organohydrogenpolysiloxane (B1), it has a structure in which hydrogen is directly bonded to Si (≡Si-H), and in addition to the vinyl group of the vinyl group-containing organopolysiloxane (A), silicone It is a polymer that undergoes a hydrosilylation reaction with the vinyl groups of the components blended into the rubber-based curable composition and crosslinks these components.

Further, the specific gravity of the branched organohydrogenpolysiloxane (B2) is in the range of 0.9 to 0.95.

Furthermore, it is preferable that the branched organohydrogenpolysiloxane (B2) usually does not have a vinyl group. Thereby, it is possible to accurately prevent the crosslinking reaction from proceeding within the molecules of the branched organohydrogenpolysiloxane (B2).

Further, as the branched organohydrogenpolysiloxane (B2), one represented by the following average composition formula (c) is preferable.

Average composition formula (c)
(H _a (R ⁷ ) _3-a SiO _1/2 ) _m (SiO _4/2 ) _n
(In formula (c), R ⁷ is a monovalent organic group, a is an integer in the range of 1 to 3, m is the number of H _a (R ⁷ ) _3-a SiO _1/2 units, and n is SiO _4/ (It is a number of ₂ units)

In formula (c), R ⁷ is a monovalent organic group, preferably a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

In formula (c), a is the number of hydride groups (hydrogen atoms directly bonded to Si), and is an integer in the range of 1 to 3, preferably 1.

Further, in formula (c), m is the number of H _a (R ⁷ ) _3-a SiO _1/2 units, and n is the number of SiO _4/2 units.

The branched organohydrogenpolysiloxane (B2) has a branched structure. Linear organohydrogenpolysiloxane (B1) and branched organohydrogenpolysiloxane (B2) differ in that their structures are linear or branched. The number of bonded alkyl groups R (R/Si) is 1.8 to 2.1 in linear organohydrogenpolysiloxane (B1) and 0.8 to 1 in branched organohydrogenpolysiloxane (B2). The range is .7.

In addition, since the branched organohydrogenpolysiloxane (B2) has a branched structure, for example, the amount of residue when heated to 1000°C at a temperature increase rate of 10°C/min in a nitrogen atmosphere is 5% or more. becomes. On the other hand, since the linear organohydrogenpolysiloxane (B1) is linear, the amount of residue after heating under the above conditions becomes almost zero.

Further, specific examples of the branched organohydrogenpolysiloxane (B2) include those having a structure represented by the following formula (3).

In formula (3), R ⁷ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, a hydrocarbon group combining these, or a hydrogen atom. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the aryl group having 1 to 8 carbon atoms include phenyl group. Examples of the substituent for R ⁷ include a methyl group and the like.

In addition, in Formula (3), a plurality of R ⁷ are mutually independent and may be different from each other or may be the same.

Furthermore, in formula (3), "-O-Si≡" represents that Si has a branched structure that extends three-dimensionally.

Note that the branched organohydrogenpolysiloxane (B2) may be used alone or in combination of two or more.

Further, in the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2), the amount of hydrogen atoms (hydride groups) directly bonded to Si is not particularly limited. However, in the silicone rubber-based curable composition, for 1 mole of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1), linear organohydrogenpolysiloxane (B1) and branched organohydrogenpolysiloxane The total amount of hydride groups in the siloxane (B2) is preferably 0.5 to 5 mol, more preferably 1 to 3.5 mol. This ensures the formation of a crosslinked network between the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) and the vinyl group-containing linear organopolysiloxane (A1). can be done.

<<Silica particles (C)>>
The silicone rubber-based curable composition of this embodiment can contain silica particles (C).

The silica particles (C) are not particularly limited, but for example, fumed silica, calcined silica, precipitated silica, etc. are used. These may be used alone or in combination of two or more.

The silica particles (C) preferably have a specific surface area of, for example, 50 to 400 m ² /g, more preferably 100 to 400 m ² /g, as determined by the BET method. Further, the average primary particle size is preferably, for example, 1 to 100 nm, more preferably about 5 to 20 nm.

By using silica particles (C) having specific surface areas and average particle diameters within the above ranges, it is possible to improve the hardness and mechanical strength of the silicone rubber formed, especially the tensile strength.

<<Silane coupling agent (D)>>
The silicone rubber-based curable composition of this embodiment can contain a silane coupling agent (D).
The silane coupling agent (D) can have a hydrolyzable group. The hydrolyzable group is hydrolyzed by water to become a hydroxyl group, and this hydroxyl group undergoes a dehydration condensation reaction with the hydroxyl group on the surface of the silica particle (C), whereby the surface of the silica particle (C) can be modified.

Moreover, this silane coupling agent (D) can contain a silane coupling agent having a hydrophobic group. As a result, this hydrophobic group is imparted to the surface of the silica particles (C), so that the cohesive force of the silica particles (C) decreases (hydrogen caused by silanol groups) in the silicone rubber-based curable composition and even in the silicone rubber. It is presumed that the dispersibility of silica particles in the silicone rubber-based curable composition is improved as a result. This increases the interface between the silica particles and the rubber matrix, increasing the reinforcing effect of the silica particles. Furthermore, it is presumed that upon deformation of the rubber matrix, the slipperiness of the silica particles within the matrix improves. By improving the dispersibility and slipperiness of the silica particles (C), the mechanical strength (for example, tensile strength, tear strength, etc.) of the silicone rubber due to the silica particles (C) is improved.

Furthermore, the silane coupling agent (D) can include a silane coupling agent having a vinyl group. As a result, vinyl groups are introduced onto the surface of the silica particles (C). Therefore, during curing of the silicone rubber-based curable composition, the vinyl groups of the vinyl group-containing organopolysiloxane (A) and the hydride groups of the organohydrogenpolysiloxane (B) undergo a hydrosilylation reaction. When a network (crosslinked structure) of these is formed, the vinyl groups of the silica particles (C) also participate in the hydrosilylation reaction with the hydride groups of the organohydrogenpolysiloxane (B), so Silica particles (C) also come to be taken in. This makes it possible to lower the hardness and increase the modulus of the silicone rubber formed.

As the silane coupling agent (D), a silane coupling agent having a hydrophobic group and a silane coupling agent having a vinyl group can be used in combination.

Examples of the silane coupling agent (D) include those represented by the following formula (4).

Y _n -Si-(X) _4-n ...(4)
In the above formula (4), n represents an integer from 1 to 3. Y represents a functional group having a hydrophobic group, a hydrophilic group, or a vinyl group; when n is 1, it is a hydrophobic group; when n is 2 or 3, at least one of them is a hydrophobic group; It is a hydrophobic group. X represents a hydrolyzable group.

The hydrophobic group is an alkyl group having 1 to 6 carbon atoms, an aryl group, or a hydrocarbon group combining these, such as a methyl group, an ethyl group, a propyl group, a phenyl group, among others, Methyl group is preferred.

Further, examples of the hydrophilic group include a hydroxyl group, a sulfonic acid group, a carboxyl group, and a carbonyl group, among which a hydroxyl group is particularly preferred. Note that, although the hydrophilic group may be included as a functional group, it is preferably not included from the viewpoint of imparting hydrophobicity to the silane coupling agent (D).

Furthermore, examples of the hydrolyzable group include a methoxy group, an alkoxy group such as an ethoxy group, a chloro group, and a silazane group, among which a silazane group is preferred because of its high reactivity with the silica particles (C). Note that those having a silazane group as a hydrolyzable group have two structures of (Y _n -Si-) in the above formula (4) due to their structural characteristics.

Specific examples of the silane coupling agent (D) represented by the above formula (4) include those having a hydrophobic group as a functional group, such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, and methyltrimethoxysilane. Alkoxysilanes such as ethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane; methyltrichlorosilane , dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane; hexamethyldisilazane; those having a vinyl group as a functional group include methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxysilane; Alkoxysilanes such as propylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane; chlorosilanes such as vinyltrichlorosilane, vinylmethyldichlorosilane; divinyltetramethyldimethoxysilane; Among these, in view of the above description, it is particularly preferable to use hexamethyldisilazane as a compound having a hydrophobic group, and divinyltetramethyldisilazane as a compound having a vinyl group.

<<Platinum or platinum compound (E)>>
The silicone rubber-based curable composition of this embodiment can contain platinum or a platinum compound (E).
Platinum or a platinum compound (E) is a catalyst component that acts as a catalyst during curing. The amount of platinum or platinum compound (E) added is a catalytic amount.

As platinum or platinum compound (E), known ones can be used, such as platinum black, platinum supported on silica, carbon black, etc., chloroplatinic acid or an alcoholic solution of chloroplatinic acid, chloroplatinic acid, etc. Examples include complex salts of platinic acid and olefins, complex salts of chloroplatinic acid and vinylsiloxane, and the like.

In addition, one type of platinum or platinum compound (E) may be used alone, or two or more types may be used in combination.

<<Water (F)>>
Further, the silicone rubber-based curable composition of the present embodiment may contain water (F) in addition to the above-mentioned components (A) to (E).

Water (F) functions as a dispersion medium for dispersing each component contained in the silicone rubber-based curable composition, and is a component that contributes to the reaction between the silica particles (C) and the silane coupling agent (D). . Therefore, in the silicone rubber, the silica particles (C) and the silane coupling agent (D) can be more reliably connected to each other, and uniform characteristics can be exhibited as a whole.

Furthermore, the silicone rubber-based curable composition of the present embodiment may contain, in addition to the above-mentioned components (A) to (F), known additive components that are blended into silicone rubber-based curable compositions. Examples include diatomaceous earth, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, cerium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, glass wool, and mica. In addition, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, thermal conductivity improvers, and the like can be appropriately blended.

In addition, in the silicone rubber-based curable composition, the content ratio of each component is not particularly limited, but is set as follows, for example.

In this embodiment, the upper limit of the content of the silica particles (C) may be, for example, 60 parts by weight or less, preferably 50 parts by weight, based on 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A). It may be less than 35 parts by weight, more preferably 35 parts by weight or less. This makes it possible to achieve a good balance between tear strength and permanent tensile strain. Further, the lower limit of the content of the silica particles (C) is not particularly limited to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A), but may be, for example, 20 parts by weight or more.

The silane coupling agent (D) is preferably contained in a proportion of, for example, 5 parts by weight or more and 100 parts by weight or less per 100 parts by weight of the vinyl group-containing organopolysiloxane (A). , more preferably in a proportion of 5 parts by weight or more and 40 parts by weight or less.
Thereby, the dispersibility of the silica particles (C) in the silicone rubber-based curable composition can be reliably improved.

Specifically, the content of the organohydrogenpolysiloxane (B) is, for example, based on 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A), the silica particles (C), and the silane coupling agent (D). The content is preferably 0.5 parts by weight or more and 20 parts by weight or less, and more preferably 0.8 parts by weight or more and 15 parts by weight or less. When the content of (B) is within the above range, a more effective curing reaction may be possible.

The content of platinum or platinum compound (E) means a catalytic amount and can be set as appropriate, but specifically, it includes vinyl group-containing organopolysiloxane (A), silica particles (C), silane coupling agent ( The platinum group metal in this component is in an amount of 0.01 to 1000 ppm by weight, preferably 0.1 to 500 ppm, based on the total amount of D). By setting the content of platinum or platinum compound (E) to the above lower limit or more, the obtained silicone rubber composition can be sufficiently cured. By controlling the content of platinum or platinum compound (E) to be below the above upper limit, the curing speed of the resulting silicone rubber composition can be improved.

Furthermore, when containing water (F), its content can be set as appropriate, but specifically, for example, 10 to 100 parts by weight per 100 parts by weight of the silane coupling agent (D). The amount is preferably in the range of 30 to 70 parts by weight, and more preferably 30 to 70 parts by weight. Thereby, the reaction between the silane coupling agent (D) and the silica particles (C) can proceed more reliably.

<Method for manufacturing silicone rubber>
Next, a method for manufacturing silicone rubber according to this embodiment will be explained.
As a method for producing silicone rubber according to the present embodiment, a silicone rubber can be obtained by preparing a curable silicone rubber composition and curing this curable silicone rubber composition.
The details will be explained below.

First, each component of the silicone rubber-based curable composition is uniformly mixed using an arbitrary kneading device to prepare a silicone rubber-based curable composition.

[1] For example, by weighing a predetermined amount of vinyl group-containing organopolysiloxane (A), silica particles (C), and silane coupling agent (D), and then kneading with an arbitrary kneading device, A kneaded product containing these components (A), (C), and (D) is obtained.

Note that this kneaded product is preferably obtained by kneading the vinyl group-containing organopolysiloxane (A) and the silane coupling agent (D) in advance, and then kneading (mixing) the silica particles (C). This further improves the dispersibility of the silica particles (C) in the vinyl group-containing organopolysiloxane (A).

Moreover, when obtaining this kneaded product, water (F) may be added to the kneaded product of each component (A), (C), and (D) as needed. Thereby, the reaction between the silane coupling agent (D) and the silica particles (C) can proceed more reliably.

Furthermore, it is preferable that each component (A), (C), and (D) be kneaded through a first step of heating at a first temperature and a second step of heating at a second temperature. Thereby, in the first step, the surface of the silica particles (C) can be surface-treated with the coupling agent (D), and in the second step, the silica particles (C) and the coupling agent (D) can be treated. By-products generated in the reaction can be reliably removed from the kneaded material. Thereafter, component (A) may be added to the obtained kneaded material and further kneaded, if necessary. Thereby, the familiarity of the components of the kneaded product can be improved.

The first temperature is preferably, for example, about 40 to 120°C, more preferably, for example, about 60 to 90°C. The second temperature is preferably, for example, about 130 to 210°C, more preferably, for example, about 160 to 180°C.

Further, the atmosphere in the first step is preferably an inert atmosphere such as a nitrogen atmosphere, and the atmosphere in the second step is preferably a reduced pressure atmosphere.

Further, the time of the first step is preferably about 0.3 to 1.5 hours, more preferably about 0.5 to 1.2 hours. The time for the second step is, for example, preferably about 0.7 to 3.0 hours, more preferably about 1.0 to 2.0 hours.

By setting the first step and the second step to the above-mentioned conditions, the above-mentioned effect can be obtained more markedly.

[2] Next, predetermined amounts of organohydrogenpolysiloxane (B) and platinum or platinum compound (E) are weighed, and then, using an arbitrary kneading device, the kneaded product prepared in the above step [1] A silicone rubber-based curable composition is obtained by kneading each component (B) and (E). The obtained silicone rubber-based curable composition may be a paste containing a solvent.

In addition, when kneading these components (B) and (E), the kneaded product prepared in advance in the above step [1] and the organohydrogenpolysiloxane (B) prepared in the above step [1] It is preferable to knead the kneaded material and platinum or the platinum compound (E), and then knead each kneaded material. This ensures that each component (A) to (E) is incorporated into the silicone rubber curable composition without proceeding with the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B). can be dispersed into

The temperature at which the components (B) and (E) are kneaded is, for example, preferably about 10 to 70°C, more preferably about 25 to 30°C, as the roll setting temperature.

Furthermore, the kneading time is preferably about 5 minutes to 1 hour, more preferably about 10 to 40 minutes.

In the above step [1] and the above step [2], by setting the temperature within the above range, the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) can proceed more accurately. Can be prevented or suppressed. In addition, in the above step [1] and the above step [2], by keeping the kneading time within the above range, each component (A) to (E) can be more reliably dispersed in the silicone rubber-based curable composition. Can be done.

The kneading device used in each step [1] and [2] is not particularly limited, and for example, a kneader, two rolls, Banbury mixer (continuous kneader), pressure kneader, etc. can be used.

Further, in this step [2], a reaction inhibitor such as 1-ethynylcyclohexanol may be added to the kneaded material. Thereby, even if the temperature of the kneaded material is set to a relatively high temperature, the progress of the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) can be more accurately prevented or suppressed. be able to.

[3] Next, silicone rubber is formed by curing the silicone rubber-based curable composition.

In this embodiment, the curing process of the silicone rubber-based curable resin composition includes, for example, heating at 100 to 250°C for 1 to 30 minutes (primary curing), followed by post-baking at 200°C for 1 to 4 hours (secondary curing). hardening).
The silicone rubber of this embodiment can be obtained through the steps described above.

A method for manufacturing the elastomer member of this embodiment will be described.
An example of a method for manufacturing an elastomer member includes a molding process of molding a silicone rubber layer (cured product of a silicone rubber curable composition) using the above-mentioned silicone rubber curable composition, and , a surface treatment step of performing one or more surface treatments selected from the group consisting of parylene coating treatment, coupling agent treatment, and surface activation treatment.

Although these molding steps and the surface treatment step may be performed separately, they can be performed in-line. Thereby, the elastomer member can be stably manufactured. Moreover, manufacturing efficiency can be improved.

In one example of the manufacturing method, the surface of the silicone rubber layer may be subjected to at least parylene coating treatment. This makes it possible to produce an elastomer member having a parylene layer on a silicone rubber layer.

In another example of the manufacturing method, the surface of the silicone rubber layer may be treated with at least a coupling agent. This makes it possible to produce an elastomer member having a coupling agent layer (silane layer) on the silicone rubber layer.

In another example of the manufacturing method, the surface of the silicone rubber layer may be subjected to at least plasma treatment and coupling agent treatment as surface treatments. This makes it possible to produce an elastomer member having a modified layer and a coupling agent layer (silane layer) on the silicone rubber layer.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and the present invention includes modifications, improvements, etc. within a range that can achieve the purpose of the present invention.
Below, examples of reference forms will be added.
1. An elastomeric member comprising a silicone rubber layer,
The surface of the silicone rubber layer is subjected to one or more surface treatments selected from the group consisting of parylene coating treatment, coupling agent treatment, and surface activation treatment,
The tack peak value obtained according to the following procedure is 5.0N or less,
Elastomer parts.
(procedure)
An aluminum probe having a flat surface with an area of 150 mm ² was used as a measurement sample under the conditions of probe moving speed: 2.3 mm/sec, probe crimping strength: 12 N, and crimping time: 6 seconds. The tack peak value on the surface of the elastomer member in the probe tack test when the elastomer member is brought into contact with the surface-treated surface and peeled upward at a probe moving speed of 2.3 mm/sec is 5. The measurement was carried out twice, and the average value of the five measurements was taken as the above tack peak value.
2. 1. The elastomer member described in
An elastomer member, wherein the surface of the silicone rubber layer is provided with at least a parylene layer formed by parylene coating treatment, and the thickness of the parylene layer is 100 nm or more and 10 μm or less.
3. 1. The elastomer member described in
An elastomer member, wherein the surface of the silicone rubber layer is treated with at least the coupling agent.
4. 1. The elastomer member described in
An elastomer member, wherein the surface of the silicone rubber layer is subjected to at least plasma treatment as the surface activation treatment and coupling agent treatment.
5. 1. ~4. The elastomer member according to any one of
An elastomer member, wherein the silicone rubber layer has a tensile strength of 6.0 MPa or more and 15 MPa or less, as measured in accordance with JIS K6251 (2004).
6. 1. ~5. The elastomer member according to any one of
An elastomer member, wherein the silicone rubber layer has a durometer hardness A of 30 or more and 90 or less, as defined in accordance with JIS K6253 (1997).
7. 1. ~6. The elastomer member according to any one of
An elastomer member, wherein the silicone rubber layer has a tear strength of 25 N/mm or more, as measured in accordance with JIS K6252 (2001).
8. 1. ~7. The elastomer member according to any one of
An elastomer member, wherein the silicone rubber layer has an elongation at break of 200% or more and 1000% or less, as measured in accordance with JIS K6251 (2004).
9. 1. ~8. The elastomer member according to any one of
An elastomer member, wherein the silicone rubber layer contains an inorganic filler.
10. 1. ~9. The elastomer member according to any one of
An elastomer member, wherein the silicone rubber layer is composed of a cured product of a silicone rubber-based curable composition.
11. 10. The elastomer member described in
An elastomer member, wherein the silicone rubber-based curable composition contains a vinyl group-containing organopolysiloxane (A).
12. 11. The elastomer member described in
An elastomer member, wherein the vinyl group-containing organopolysiloxane (A) contains a first vinyl group-containing organopolysiloxane having a vinyl group content of 0.4 mol% or less.
13. 10. ~12. The elastomer member according to any one of
The silicone rubber layer-based curable composition contains silica particles (C),
An elastomer member in which the content of the silica particles (C) is 10 parts by weight or more and 60 parts by weight or less based on 100 parts by weight of the vinyl group-containing organopolysiloxane (A).
14. 1. ~13. The elastomer member according to any one of
Elastomer members used for sliding members.
15. a molding process of molding a silicone rubber layer;
a surface treatment step of subjecting the surface of the silicone rubber layer to one or more surface treatments selected from the group consisting of parylene coating treatment, coupling agent treatment, and surface activation treatment;
A method for manufacturing an elastomer member comprising a silicone rubber layer, the method comprising:
The molding step and the surface treatment step are performed in-line.
A method for manufacturing an elastomer member.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the description of these Examples.

The raw material components are shown below.
(Vinyl group-containing organopolysiloxane (A))
・Low vinyl group-containing linear organopolysiloxane (A1-1): Vinyl group-containing dimethylpolysiloxane synthesized according to Synthesis Scheme 1 (structure represented by formula (1-1), with only R ¹ (terminal) being a vinyl group) structure)
・High vinyl group-containing linear organopolysiloxane (A1-2): vinyl group-containing dimethylpolysiloxane synthesized by synthesis scheme 2 (structure represented by formula (1-1), with R ¹ and R ² being vinyl groups) some structure)

(Organohydrogenpolysiloxane (B))
・Organohydrogenpolysiloxane (B): “TC-25D” manufactured by Momentive
(Silica particles (C))
・Silica particles (C): Silica fine particles (particle size 7 nm, specific surface area 300 m ² /g), “AEROSIL 300” manufactured by Nippon Aerosil Co., Ltd.
(Silane coupling agent (D))
- Silane coupling agent (D-1): Hexamethyldisilazane (HMDZ), manufactured by Gelst, "HEXAMETHYLDISILAZANE (SIH6110.1)"
- Silane coupling agent (D-2): Divinyltetramethyldisilazane, manufactured by Gelst, "1,3-DIVINYLTETRAMETHYLDISILAZANE (SID4612.0)"
(Platinum or platinum compound (E))
・Platinum or platinum compound (E): Platinum compound, manufactured by Momentive, "TC-25A"

(Synthesis of vinyl group-containing organopolysiloxane (A))
[Synthesis scheme 1: Synthesis of low vinyl group-containing linear organopolysiloxane (A1-1)]
A low vinyl group-containing linear organopolysiloxane (A1-1) was synthesized according to the following formula (5).
That is, 74.7 g (252 mmol) of octamethylcyclotetrasiloxane and 0.1 g of potassium siliconate were placed in a 300 mL separable flask equipped with a cooling tube and stirring blade and replaced with Ar gas, and heated to 120° C. for 30 minutes. Stirred. At this time, an increase in viscosity was confirmed.
Thereafter, the temperature was raised to 155°C, and stirring was continued for 3 hours. After 3 hours, 0.1 g (0.6 mmol) of 1,3-divinyltetramethyldisiloxane was added, and the mixture was further stirred at 155° C. for 4 hours.
Furthermore, after 4 hours, the mixture was diluted with 250 mL of toluene and washed three times with water. The organic layer after washing was washed several times with 1.5 L of methanol to purify it by reprecipitation and separate the oligomer and polymer. The obtained polymer was dried under reduced pressure at 60° C. overnight to obtain a low vinyl group-containing linear organopolysiloxane (A1-1) (Mn=2.2×10 ⁵ , Mw=4.8×10 ⁵ ). Furthermore, the vinyl group content calculated by H-NMR spectrum measurement was 0.04 mol%.

[Synthesis scheme 2: Synthesis of high vinyl group-containing linear organopolysiloxane (A1-2)]
In the synthesis step of (A1-1) above, in addition to 74.7 g (252 mmol) of octamethylcyclotetrasiloxane, 0.2 g (252 mmol) of 2,4,6,8-tetramethyl 2,4,6,8-tetravinylcyclotetrasiloxane. By following the same synthesis process as (A1-1) except that 86 g (2.5 mmol) was used, a high vinyl group-containing linear organopolysiloxane (A1- 2) was synthesized. (Mn=2,3×10 ⁵ , Mw=5,0×10 ⁵ ). Furthermore, the vinyl group content calculated by H-NMR spectrum measurement was 0.93 mol%.

(Preparation of silicone rubber-based curable composition)
A silicone rubber-based curable composition was prepared as follows.
First, a mixture of a 95% vinyl group-containing organopolysiloxane (A), a silane coupling agent (D), and water (F) is kneaded in advance in the proportions shown in Table 1, and then silica particles (C) are added to the mixture. was added and further kneaded to obtain a kneaded product (silicone rubber compound).
Here, the kneading after addition of the silica particles (C) includes the first step of kneading for 1 hour at 60 to 90°C under a nitrogen atmosphere for the coupling reaction, and the removal of by-products (ammonia). For this purpose, a second step of kneading for 2 hours at 160 to 180°C under a reduced pressure atmosphere is performed, followed by cooling and adding the remaining 5% vinyl group-containing organopolysiloxane (A) twice. Added in portions and kneaded for 20 minutes.
Subsequently, 4.5 parts by weight of organohydrogenpolysiloxane (B) and 0.5 parts by weight of platinum or platinum compound (E) were added to 100 parts by weight of the obtained kneaded product (silicone rubber compound), and the mixture was kneaded with a roll. A silicone rubber-based curable composition was obtained.

(Preparation of sheet-shaped silicone rubber)
The obtained silicone rubber-based curable composition was pressed at 170° C. and 10 MPa for 10 minutes to form a sheet with a thickness of 1 mm, and was primarily cured. Subsequently, it was heated at 200° C. for 4 hours to perform secondary curing to obtain a sheet-like silicone rubber (cured product of a silicone rubber-based curable composition).

(Production of elastomer member)

[Example 1]
Parylene C was deposited on the surface of a sheet-like silicone rubber (silicone rubber layer) by vapor phase deposition (parylene coating treatment). Parylene was deposited to a thickness of 1 μm.
Through the above steps, an elastomer member A was obtained in which a parylene layer (surface treatment layer) was formed on the silicone rubber layer.

[Example 2]
As a coupling agent, 3-aminopropyltrimethoxysilane (KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd., an amino group-containing silane compound) was used.
A coupling agent was applied to the surface of a sheet-like silicone rubber (silicone rubber layer), annealed at 110° C. for 30 minutes, and washed with ethanol to form a silane layer of 35 μm.
Through the above steps, an elastomer member B in which a silane layer (surface treatment layer) was formed on the silicone rubber layer was obtained.

[Example 3]
Same as Example 2 except that a solution containing 20% by weight of 3-aminopropyltrimethoxysilane prepared by mixing 3-aminopropyltrimethoxysilane with tetrahydrofuran (THF) was used as the coupling agent. Thus, an elastomer member C having a 28 μm thick silane layer formed thereon was obtained.

[Example 4]
The surface of the sheet-like silicone rubber (silicone rubber layer) was subjected to oxygen plasma treatment under the following conditions: oxygen flow rate: 200 sccm, pressure: 3 MPa, high frequency output: 300 W, and treatment time: 2 minutes.
Subsequently, 3-aminopropyltrimethoxysilane was mixed with ethanol as a coupling agent to prepare a solution containing 20% by weight of 3-aminopropyltrimethoxysilane.
The prepared coupling agent was applied onto the surface of the plasma-treated silicone rubber layer, annealed at 110° C. for 30 minutes, and washed with ethanol to form a 5 μm thick silane layer.
Through the above steps, an elastomer member D was obtained in which a plasma-treated layer and a silane layer (surface-treated layer) were formed on the silicone rubber layer.

[Comparative example 1]
As the elastomer member E, the obtained sheet-shaped silicone rubber was used as it was.

[Comparative example 3]
A commercially available silicone surface treatment agent (liquid silicone rubber) was applied to the surface of a sheet of silicone rubber (silicone rubber layer) and dried at 150° C. for 10 minutes to form a 50 μm thick silicone surface treatment agent layer. .
Through the above steps, an elastomer member F was obtained in which a silicone-based surface treatment agent layer (surface treatment layer) was formed on the silicone rubber layer.

The obtained elastomer member was evaluated based on the following evaluation items.

(Tuck peak value)
The tack peak value was measured using a tackiness checker manufactured by Toyo Seiki Co., Ltd. as a measuring device. As the measurement mode, Constant Load was used, in which the probe was pushed in to a set pressure value and control was continued to hold the pressure value until the set time elapsed.
Specifically, an aluminum probe having a flat surface with an area of 150 mm ² was attached to the flat surface of the aluminum probe under the conditions of probe moving speed: 2.3 mm/sec, probe crimping strength: 12 N, and crimping time: 6 seconds. was brought into contact with the surface of the measurement sample (Examples 1 to 4, Comparative Example 2: surface treatment layer of elastomer member, Comparative Example 1: silicone rubber layer of elastomer member) at a probe moving speed of 2.3 mm/sec. The tack peak value on the surface of the silicone rubber layer by a probe tack test when peeled upward was measured five times, and the average value of these five measurements was taken as the above-mentioned tack peak value TP (N).

<Slip property test>
Two elastomer members of each Example and each Comparative Example were prepared, and the two were placed on a flat surface of a test stand in a stacked state. The elastomer members of Examples 1 to 4 and Comparative Example 2 were stacked with the surfaces of the surface treatment layers in contact with each other, and the elastomer member of Comparative Example 1 was stacked with the surfaces of the silicone rubber layers in contact with each other. .
Next, after placing a weight of 200 g, the two elastomer members were slid horizontally with their surfaces in contact with each other, and a rubbing test was conducted between the sheets, based on the evaluation criteria below. evaluated.

A case where strong resistance was felt during rubbing and the silicone rubber layer did not slip was rated as ×, and a case where no resistance was felt during rubbing was rated as ○.

(Hardness: Durometer hardness A)
Six pieces of the obtained elastomer members each having a thickness of about 1 mm were laminated to form a 6 mm test piece. Type A durometer hardness of the obtained test piece was measured in accordance with JIS K6253 (1997). Using two samples, each sample was measured with n=5, and the average value of 10 measurements was taken as the measured value.

(tear strength)
Using the obtained elastomer member having a thickness of about 1 mm, a crescent-shaped test piece was prepared in accordance with JIS K6252 (2001), and the tear strength of the obtained crescent-shaped test piece at 25° C. was measured. The unit is N/mm. The measurement was performed using five samples, and the average value of the five samples was taken as the measured value.

(Tensile strength)
Using the obtained elastomer member with a thickness of about 1 mm, a dumbbell-shaped No. 3 test piece was prepared in accordance with JIS K6251 (2004), and the tensile strength of the obtained test piece at 25° C. was measured. The unit is MPa. Three samples were used, the average value of the three was used as the measured value, and the standard deviation thereof was also calculated.

(Elongation at break)
Using the obtained elastomer member with a thickness of approximately 1 mm, a dumbbell-shaped No. 3 test piece was prepared in accordance with JIS K6251 (2004), and the obtained dumbbell-shaped No. 3 test piece was tested at 25°C. The elongation at break was measured.
The elongation at break was calculated based on the formula: [distance between gauge lines (mm)]÷[distance between gauge lines (20 mm)]×100. The unit is %. Three samples were used, the average value of the three was used as the measured value, and the standard deviation thereof was also calculated.

(Tensile stress)
Using the obtained elastomer member with a thickness of approximately 1 mm, a dumbbell-shaped No. 3 test piece was prepared in accordance with JIS K6251 (2004), and the obtained dumbbell-shaped No. 3 test piece was tested at 25°C. The tensile stress at the time of 100% to 600% elongation was measured. The unit is MPa. Three samples were used, and the average value of the three samples was used as the measured value.

The elastomer members of Examples 1 to 4 have suppressed fluctuations in mechanical properties (rubber properties) compared to Comparative Example 2, and have smaller tack peak values and superior slip properties compared to Comparative Example 1. showed that.
Note that bleeding was suppressed on the surface-treated surfaces of the elastomer members of Examples 1 to 4, indicating that they had resistance to bleeding.
The elastomer members of Examples 1 to 4 can be suitably used for sliding members.

10 Silicone rubber layer 20 Surface treatment layer 100 Elastomer member

Claims (11)

An elastomeric member comprising a silicone rubber layer,
The silicone rubber layer is composed of a cured product of a silicone rubber-based curable composition containing a vinyl group-containing organopolysiloxane (A) and an organohydrogenpolysiloxane (B),
On the surface of the silicone rubber layer,
Is it at least parylene coated ?
has been at least treated with a coupling agent, or
At least plasma treatment and coupling agent treatment as surface activation treatment have been performed ,
The tack peak value on the surface of the silicone rubber layer obtained according to the following procedure is 5.0 N or less,
Elastomer parts.
(procedure)
An aluminum probe having a flat surface with an area of 150 mm ² was used as a measurement sample under the conditions of probe moving speed: 2.3 mm/sec, probe crimping strength: 12 N, and crimping time: 6 seconds. The tack peak value on the surface of the silicone rubber layer by a probe tack test when it is brought into contact with the surface treated surface of the elastomer member and peeled off upward at a probe moving speed of 2.3 mm/sec. Measurement is performed five times, and the average value of the five measured values is taken as the above tack peak value. The elastomeric member according to claim 1,
An elastomer member, wherein a parylene layer formed by the parylene coating treatment is provided on the surface of the silicone rubber layer, and the parylene layer has a thickness of 100 nm or more and 10 μm or less. The elastomer member according to claim 1 or 2 ,
An elastomer member, wherein the silicone rubber layer has a tensile strength of 6.0 MPa or more and 15 MPa or less, as measured in accordance with JIS K6251 (2004). The elastomer member according to any one of claims 1 to 3 ,
An elastomer member, wherein the silicone rubber layer has a durometer hardness A of 30 or more and 90 or less, as defined in accordance with JIS K6253 (1997). The elastomer member according to any one of claims 1 to 4 ,
An elastomer member, wherein the silicone rubber layer has a tear strength of 25 N/mm or more, as measured in accordance with JIS K6252 (2001). The elastomer member according to any one of claims 1 to 5 ,
An elastomer member, wherein the silicone rubber layer has an elongation at break of 200% or more and 1000% or less, as measured in accordance with JIS K6251 (2004). The elastomer member according to any one of claims 1 to 6 ,
An elastomer member, wherein the silicone rubber layer contains an inorganic filler. The elastomer member according to any one of claims 1 to 7 ,
An elastomer member, wherein the vinyl group-containing organopolysiloxane (A) contains a first vinyl group-containing organopolysiloxane having a vinyl group content of 0.4 mol% or less. The elastomer member according to any one of claims 1 to 8 ,
The silicone rubber-based curable composition contains silica particles (C),
An elastomer member, wherein the content of the silica particles (C) is 10 parts by weight or more and 60 parts by weight or less based on 100 parts by weight of the vinyl group - containing organopolysiloxane (A). The elastomer member according to any one of claims 1 to 9 ,
Elastomer members used for sliding members. a molding step of molding a silicone rubber layer constituted by a cured product of a silicone rubber curable composition containing a vinyl group-containing organopolysiloxane (A) and an organohydrogenpolysiloxane (B);
a surface treatment step of performing a surface treatment on the surface of the silicone rubber layer;
A method for manufacturing an elastomer member comprising a silicone rubber layer, the method comprising:
The surface treatment step
At least includes parylene coating treatment, or
comprises at least a coupling agent treatment, or
It includes at least plasma treatment and coupling agent treatment as surface activation treatment,
The molding step and the surface treatment step are performed in-line.
A method for manufacturing an elastomer member.

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