JP2018172633A - Resin movable member and structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin movable member excellent in mechanical strength and durability.SOLUTION: A resin movable member of the embodiment is configured so that, when extension operation is performed repeatedly 5 times, a hysteresis loss in first extension operation is ΔE1, a hysteresis loss in second extension operation is ΔE2, a variation ratio of the second hysteresis loss with respect to the first hysteresis loss |ΔE2/ΔE1|×100 is H1(%), and tension strength which is measured according to JIS K6251(2004) is S(MPa), H1 is 25 or less, and H1×S is 125 or more and 400 or less.SELECTED DRAWING: None

Description

  The present invention relates to a resin movable member and a structure.

  So far, movable members constituting movable parts of various instruments and devices have been studied. As this type of technology, for example, the technology described in Patent Document 1 is known. Patent Document 1 describes an outer tube that covers the main body of an endoscope flexible tube. This document describes that hysteresis loss can be reduced by using a thermoplastic elastomer that does not contain an inorganic powder filler in the outer tube (paragraph 0016 of Patent Document 1).

JP 11-86637 A

  However, as a result of studies by the present inventor, it has been found that the tube described in Document 1 has room for improvement in terms of mechanical strength and durability against deformation. In addition, there is room for improvement in mechanical strength and durability even when the tube is applied to movable parts such as medical instruments and devices other than such medical tubes, industrial robots, and electronic devices. It was.

As a result of investigation by the present inventors, the following knowledge was obtained.
In general, the mechanical strength can be increased by adding a reinforcing material such as an inorganic filler to the elastomer, but on the contrary, when the elastomer is deformed during use, the plastic deformation generated therein is large. Thus, the hysteresis loss tends to increase.

In contrast, the present inventor has found that by appropriately controlling the resin structure such as the crosslinking density, the hysteresis loss can be reduced while increasing the mechanical strength.
As a result of further investigation, the tensile strength S is used as an index for evaluating the state of mechanical strength, and the hysteresis loss fluctuation ratio (ΔE2 / ΔE1) in the first and second stretching operations is used as an index for evaluating the state of hysteresis loss. ) And using the product value of the tensile strength S and the hysteresis loss fluctuation ratio (ΔE2 / ΔE1) as an index, it was found that the balance between the mechanical strength and the hysteresis loss can be stably evaluated. .
As a result of further earnest research based on such knowledge, the product of the tensile strength S and the hysteresis loss fluctuation ratio (ΔE2 / ΔE1) is set to a predetermined value or more while controlling the hysteresis loss fluctuation ratio (ΔE2 / ΔE1) to be small. Thus, it was found that a resin movable member having excellent mechanical strength and durability during repeated deformation can be realized, and the present invention has been completed.
Moreover, it turned out that the resin-made movable member obtained based on such a parameter | index is suitable for the use environment used so that it may deform | transform repeatedly following the operation | movement of the movable part of various instruments and apparatuses.

According to the present invention,
The following stretching operation is repeated 5 times, the hysteresis loss at the first stretching operation is ΔE1, the hysteresis loss at the second stretching operation is ΔE2, and the second hysteresis with respect to the first hysteresis loss. The loss ratio | ΔE2 / ΔE1 | × 100 is defined as H1 (%).
When the tensile strength measured in accordance with JIS K6251 (2004) is S (MPa),
A resin movable member is provided in which H1 is 25 or less and H1 × S is 125 or more and 400 or less.
(Extension operation)
The stretching operation is an operation in which the dumbbell test piece is stretched from a displacement amount of 0% to 500% at a room temperature of 25 ° C. and a stretching speed of 1000 mm / min, and then contracted from a displacement amount of 500% to 0% by a removal force. .

Also according to the invention,
A structure including the above-mentioned fat movable member is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the resin-made movable members and structures excellent in mechanical strength and durability are provided.

It is a figure for demonstrating expansion | extension operation.

  The resin movable member of the present embodiment repeats the following extension operation five times, and the hysteresis loss at the first extension operation is ΔE1, and the hysteresis loss at the second extension operation is ΔE2. It is assumed that | ΔE2 / ΔE1 | × 100, which is the fluctuation ratio of the second hysteresis loss to the first hysteresis loss, is H1 (%), and the tensile strength measured in accordance with JIS K6251 (2004) is S (MPa). Then, H1 can be 25 or less, and H1 × S can be 125 or more and 400 or less.

  In the present embodiment, the stretching operation is a room temperature of 25 ° C., a stretching speed of 1000 mm / min, and a dumbbell test piece is stretched from 0% to 500% of displacement, and thereafter, from 500% to 0% of displacement by removing force. The operation can be made to contract. This extension operation may be performed continuously.

  The hysteresis loss can be a difference energy ΔE between the extension energy (mJ) at the time of extension and the deenergizing energy (mJ) at the time of deformation return in one extension operation. These stretching energy and deenergizing energy are indicated by a stress-strain curve obtained by the stretching operation, that is, the vertical axis: the load (N) during the stretching operation, and the horizontal axis: the displacement amount (mm) during the stretching operation. It can be calculated from the area (having energy dimension) obtained by integration from the curve.

The inventor uses the tensile strength S as an index for evaluating the state of mechanical strength, and as an index for evaluating the state of hysteresis loss, the hysteresis loss fluctuation ratio H1 (| ΔE2) in the first and second stretching operations. / ΔE1 | × 100) and using the product value of tensile strength S and hysteresis loss fluctuation ratio H1 as an index, it was found that the balance between mechanical strength and hysteresis loss can be evaluated stably. did.
Further, the present inventor considered that the first hysteresis loss ΔE1 varies depending on the initial state such as hardness, and it is difficult to reduce ΔE1 itself.
Therefore, it was considered that the influence of the difference in the initial state such as hardness can be reduced by dividing the hysteresis loss ΔEN of the predetermined Nth time by the hysteresis loss ΔE1 of the first time in the hysteresis loss fluctuation ratio.
Based on such an idea, while the hysteresis loss fluctuation ratio H1 is set to the upper limit value or less, the product value of the tensile strength S and the hysteresis loss fluctuation ratio H1 is set to the above lower limit value or more, so that the mechanical strength is increased. And it discovered that the resin movable member excellent in durability with respect to a deformation | transformation was realizable, and came to complete this invention.

  Further, in the resin movable member of the present embodiment, the hysteresis loss at the time of the fifth extension operation is ΔE5, and the variation ratio of the fifth hysteresis loss to the first hysteresis loss is | ΔE5 / ΔE1 | × 100. Is H2 (%), H2 is 15 or less, and H2 × S can be 85 or more and 300 or less.

In the hysteresis loss fluctuation ratio H2, by adopting the fifth hysteresis loss ΔE5 as an index, the durability during repeated deformation is stably evaluated in a usage environment where repeated deformation such as expansion and contraction is continuously performed. I understood that I could do it.
Accordingly, by setting the product value of the tensile strength S and the hysteresis loss fluctuation ratio H2 to be equal to or higher than the above lower limit value while setting the hysteresis loss fluctuation ratio H2 to be equal to or less than the above upper limit value, A resin movable member excellent in durability can be realized.

Further, in the resin movable member of the present embodiment, | ΔE5 / ΔE2 | × 100, which is the fluctuation ratio of the fifth hysteresis loss to the second hysteresis loss, can be 80% or less.
By using not the hysteresis loss ΔE1 at the time of the first extension operation but also the hysteresis loss ΔE2 to ΔE5 from the next time excluding the first time as an index, the durability in a usage environment where repeated deformation is continuously performed is stable. It was found that it can be evaluated. Although the detailed mechanism is not clear, it can be considered as follows. In the first stretching operation, the composition in the resin movable member tends to be rearranged by stretching. For this reason, if it is the extension operation after the 2nd time, since the influence of the rearrangement of such a composition can be suppressed, it is thought that the durability at the time of repeated deformation by the composition of the resin movable member can be better evaluated.
And, it is considered that the durability of the resin movable member can be stably evaluated as described above by considering the change rate of hysteresis loss when a plurality of stretching operations are repeated from the second time to the fifth time. .
Therefore, by setting the above | ΔE5 / ΔE2 | × 100 to the lower limit value or less, it is possible to further improve the durability of the resin movable member during repeated deformation.

  According to the present embodiment, it is possible to realize a resin movable member having excellent durability and a structure including the resin movable member. The resin movable member according to the present embodiment is suitable for a use environment in which the resin movable member is used so as to be repeatedly deformed following the movement of a movable part of an instrument or device.

  The resin movable member of the present embodiment is an example of a medical instrument / apparatus application, for example, a medical tube material; a sealing material; a packing material; a connector material; a keypad material; a drive mechanism; Can be configured. For example, by applying the resin movable member of the present embodiment to a medical tube, the medical tube has excellent kink resistance, scratch resistance, insertability, and transparency, and also has excellent resilience. Become. Examples of the medical tube include the following medical catheters, manipulators, leads, and the like.

  The resin movable member of the present embodiment constitutes a part of, for example, a drive mechanism such as a joint; a wiring mechanism such as a wiring cable or a connector; an operation mechanism such as a manipulator; can do.

  The resin movable member of the present embodiment is a stretchable wiring or wiring board used as a wearable device that can be worn on a human body, for example, as an example of an electronic device application; optical fiber, flat cable, wiring structure A part of a cable such as a cable guide; a sensor such as a touch panel, a force sensor, a MEMS, and a seat sensor;

  In addition, the resin movable member of the present embodiment is a living product having flexibility, extensibility, or foldability such as a packaging material such as a gas barrier film; a cooking utensil; a hose; a fixing belt; a switch; a sheet material; Can constitute a part of

  Next, the characteristics of the resin movable member of this embodiment will be described.

  In the resin movable member of the present embodiment, the hysteresis loss at the first extension operation is ΔE1, the hysteresis loss at the second extension operation is ΔE2, and the second hysteresis with respect to the first hysteresis loss. The loss variation ratio | ΔE2 / ΔE1 | × 100 is defined as H1 (%), and the tensile strength measured in accordance with JIS K6251 (2004) is defined as S (MPa). At this time, the upper limit value of H1 is, for example, 25 or less, preferably 24 or less, more preferably 22 or less, and the lower limit value of H1 × S is, for example, 125 or more, preferably 130 or more, more preferably 150 or more. Thereby, the resin-made movable member excellent in mechanical strength and durability against deformation can be realized. On the other hand, the lower limit value of H1 is not particularly limited, but may be, for example, greater than 0 or 1 or more. Further, the upper limit value of H1 × S is not particularly limited, but may be 400 or less, or 300 or less, for example.

  Further, in the resin movable member of the present embodiment, the hysteresis loss at the time of the fifth extension operation is ΔE5, which is a variation ratio of the fifth hysteresis loss to the first hysteresis loss | ΔE5 / ΔE1 | × 100. Is H2 (%). At this time, the upper limit value of H2 is, for example, 15 or less, preferably 14.8 or less, more preferably 14.5 or less, and the lower limit value of H2 × S is, for example, 85 or more. Yes, preferably 88 or more, more preferably 90 or more. Thereby, the resin movable member excellent in mechanical strength and durability against deformation at the time of repeated deformation can be realized. On the other hand, the lower limit value of H2 is not particularly limited, but may be, for example, more than 0 or 1 or more. Further, the upper limit value of H2 × S is not particularly limited, but may be, for example, 300 or less, or 200 or less.

  In the resin movable member of the present embodiment, the upper limit value of | ΔE5 / ΔE2 | × 100, which is the fluctuation ratio of the fifth hysteresis loss to the second hysteresis loss, is, for example, 80% or less, preferably It is 78% or less, more preferably 75% or less. Thereby, the resin movable member excellent in durability at the time of repeated deformation can be realized. On the other hand, the lower limit value of | ΔE5 / ΔE2 | × 100 is not particularly limited, but may be, for example, more than 0% or 1% or more.

The resin movable member of the present embodiment, at room temperature 25 ° C. which is measured according to JIS K6251 (2004), the upper limit of the tensile stress _{M 50} at 50% elongation, for example, may be below 1.5MPa Preferably, it may be 1.3 MPa or less, more preferably 1.0 MPa or less, and even more preferably 0.8 MPa or less. Thereby, since the stress in the initial stage of a deformation | transformation can be made small, the initial movement of operation of an instrument or an apparatus can be made favorable. Further, the lower limit value of the tensile stress M ₅₀ at the time of 50% elongation of the resin movable member is not particularly limited, but may be, for example, 0.05 MPa or more, or 0.1 MPa or more. Thereby, the mechanical strength of the resin movable member can be improved.

According to the resin movable member of the present embodiment, it is possible to reduce the stress M ₅₀ Tensile at 50% elongation. That is, the stress in the low strain region of the resin movable member can be reduced. As a result, it is possible to realize a resin movable member that is easily deformable and can be easily deformed such as bent and stretched.

The resin movable member of the present embodiment, at room temperature 25 ° C. which is measured according to JIS K6251 (2004), the upper limit of the stress _{M 100} Tensile at 100% elongation, for example, be less 3.0MPa The pressure is preferably 2.5 MPa or less, more preferably 2.0 MPa or less, and still more preferably 1.9 MPa or less. Thereby, since the stress in the middle period from the start of deformation to the end of deformation can be reduced, the operation of the instrument or device can be performed smoothly. The lower limit of the stress _{M 100} Tensile at 100% elongation of the resin movable member is not particularly limited, for example, may be 0.1MPa or more, may be more than 0.3 MPa. Thereby, the mechanical strength of the resin movable member can be improved.

The upper limit value of the tensile stress M ₆₀₀ at 600% elongation at room temperature of 25 ° C. measured according to JIS K6251 (2004) of the resin movable member of the present embodiment may be, for example, 7.0 MPa or less. Preferably, it may be 6.5 MPa or less, more preferably 6.0 MPa or less, and even more preferably 5.5 MPa or less. As a result, the stress at the end of the deformation can be reduced, so that it can be deformed smoothly and greatly according to the operation of the instrument or equipment, so that the operability can be improved and applied to a movable part with a large movement. Can do. Further, the lower limit value of the tensile stress M ₆₀₀ when the resin movable member is stretched by 600% is not particularly limited, but may be, for example, 1.5 MPa or more, or 2.0 MPa or more. Thereby, the mechanical strength of the resin movable member can be improved.

Further, according to the resin movable member of the present embodiment, it is possible to reduce the tensile stress _{M 600} at the time of stress _{M 100,} and 600% elongation tensile during stress _M 50, 100% elongation tensile at 50% elongation . That is, in the low-strain region to the high-strain region of the resin movable member, the stress at the initial stage of strain is small, the stress at the middle stage of strain is small, and the stress at the late stage of strain can be reduced. As a result, it is possible to realize a resin movable member that is easily deformable and can be easily deformed such as bent and stretched.

  According to this embodiment, it is possible to realize a resin movable member excellent in deformability and durability, and a structure including the resin movable member.

  The lower limit value of the tensile strength measured according to JIS K6251 (2004) of the resin movable member of the present embodiment is, for example, 7.0 MPa or more, preferably 7.5 MPa or more, and more preferably. Is 8.0 MPa or more. Thereby, the mechanical strength of the resin movable member can be improved. Further, the breaking energy can be increased. For this reason, the resin movable member excellent in durability which can endure repeated deformation | transformation is realizable. On the other hand, the upper limit value of the tensile strength of the resin movable member is not particularly limited, but may be, for example, 15 MPa or less, or 13 MPa or less. Thereby, the operativity of various apparatuses and instruments can be made favorable.

  The lower limit value of the tear strength measured according to JIS K6252 (2001) of the resin movable member of the present embodiment is, for example, 25 N / mm or more, preferably 30 N / mm or more, more preferably. Is 33 N / mm or more, more preferably 35 N / mm or more. Thereby, the scratch resistance and mechanical strength of the resin movable member can be improved. Moreover, the durability at the time of repeated use of the resin movable member can be improved. On the other hand, the upper limit value of the tear strength of the resin movable member is not particularly limited, but may be, for example, 70 N / mm or less, or 60 N / mm or less. Thereby, the various characteristics of the hardened | cured material of the resin movable member of this embodiment can be balanced.

The upper limit value of the durometer hardness A defined in accordance with JIS K6253 (1997) of the resin movable member of the present embodiment may be, for example, 80 or less, 75 or less, or 70 or less. On the other hand, the lower limit value of the durometer hardness A may be, for example, 10 or more, 15 or more, or 20 or more.
In the high hardness type resin movable member, the durometer hardness A may be, for example, 40 or more and 80 or less, preferably 45 or more and 75 or less, and more preferably 50 or more and 70 or less.
In the low hardness type resin movable member, the durometer hardness A may be, for example, 10 or more and less than 40, preferably 15 or more and 39 or less, and more preferably 20 or more and 38 or less. Thereby, the softness | flexibility of the resin movable member can be improved and the resin movable member excellent in the ease of deformation | transformation from which deformation | transformation, such as bending and expansion | extension, becomes easy can be implement | achieved. Thereby, the operativity of various apparatuses and instruments can be made favorable.

  The upper limit value of the elongation at break as measured in accordance with JIS K6251 (2004) of the resin movable member of the present embodiment may be, for example, 1500% or less, preferably 1200% or less, more preferably 1000. % Or less may be sufficient. Thereby, the mechanical strength of the resin movable member at room temperature can be improved. On the other hand, the lower limit value of the elongation at break is, for example, 200% or more, preferably 250% or more, more preferably 300% or more, and further preferably 400% or more. Thereby, the high elasticity and durability of the resin movable member at room temperature can be improved.

  In the present embodiment, for example, the type and amount of each component contained in the resin movable member, the preparation method of the composition for forming the resin movable member, the method of manufacturing the resin movable member, and the like are appropriately selected. Thus, the hysteresis loss change rate, tensile stress, breaking energy, tensile strength, tear strength, and hardness can be controlled. Among these, for example, the type and blending ratio of the resin constituting the resin movable member, the crosslink density and crosslink structure of the resin, etc. are appropriately controlled, and the blending ratio of the inorganic filler and the dispersibility of the inorganic filler are improved. And the like, as an element for bringing the rate of change in hysteresis loss, tensile stress, breaking energy, tensile strength, tear strength, hardness into a desired numerical range, and further, the content of the inorganic filler (resin component 100) The content of the inorganic filler with respect to parts by weight) / hardness, for example, less than 1 can be cited as an element for setting the hysteresis loss change rate in a desired numerical range.

  Hereinafter, the composition of the resin movable member of this embodiment will be described.

  The resin movable member of the present embodiment may be composed of a thermosetting resin or a rubber material. These may be used alone or in combination of two or more.

  The thermoplastic resin is selected from the group consisting of, for example, polyolefin resins, polystyrene resins, polyamide resins, polyacetal resins, saturated polyester resins, polyacrylonitrile resins, vinyl chloride resins, and polyurethane resins. One or more can be included. These may be used alone or in combination of two or more.

  The rubber material may include one or more selected from the group consisting of silicone rubber, fluorine rubber, nitrile rubber, acrylic rubber, styrene rubber, chloroprene rubber, ethylene propylene rubber, and urethane rubber. These may be used alone or in combination of two or more. Among these, acrylic rubber, silicone rubber, or urethane rubber can be used from the viewpoint of balance of characteristics, and silicone rubber can be preferably used.

  In addition, the resin movable member of the present embodiment may be added with any component capable of exhibiting the function of a movable part such as a medical instrument / device, an industrial robot, or an electronic device. For example, from the viewpoint of increasing the mechanical strength, the resin movable member can include an inorganic filler. As the inorganic filler, known materials can be used, and for example, silica particles can be used.

  Hereinafter, a case where a silicone rubber-based curable composition is used as the silicone rubber will be described as an example of the resin movable member of the present embodiment. The resin movable member may be composed of a cured product of a silicone rubber-based curable composition.

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

  The vinyl group-containing organopolysiloxane (A) can 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 a vinyl group, and this vinyl group serves as a crosslinking point during curing.

  The vinyl group content of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited. For example, the vinyl group-containing linear organopolysiloxane preferably has 2 or more vinyl groups in the molecule and 15 mol% or less. More preferably, it is 0.01-12 mol%. Thereby, the quantity of the vinyl group in vinyl group containing linear organopolysiloxane (A1) is optimized, and formation of the network with each component mentioned later can be performed reliably. In this embodiment, “to” means to include numerical values at both ends thereof.

  In addition, in this specification, vinyl group content is the mol% of a vinyl group containing siloxane unit when all the units which comprise a vinyl group containing linear organopolysiloxane (A1) are 100 mol%. . However, one vinyl group is considered for one vinyl group-containing siloxane unit.

  The degree of polymerization of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but for example, it is preferably in the range of about 1000 to 10000, more preferably about 2000 to 5000. In addition, a polymerization degree can be calculated | required as a number average polymerization degree (or number average molecular weight) of polystyrene conversion in GPC (gel permeation chromatography) which used chloroform as a developing solvent, for example.

  Furthermore, 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 polymerization degree and specific gravity within the above ranges, the resulting silicone rubber has heat resistance, flame retardancy, chemical stability, etc. Can be improved.

  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, alkenyl group, aryl group having 1 to 10 carbon atoms, or a hydrocarbon group obtained by combining these. As a C1-C10 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. As a C1-C10 alkenyl group, a vinyl group, an allyl group, a butenyl group etc. are mentioned, for example, Among these, a vinyl group is preferable. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

R ² is a substituted or unsubstituted alkyl group, alkenyl group, aryl group having 1 to 10 carbon atoms, or a hydrocarbon group obtained by combining these. As a C1-C10 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include a vinyl group, an allyl group, and a butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

R ³ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these. As a C1-C8 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group.

Furthermore, examples of the substituent for R ¹ and R ² in formula (1) include a methyl group and a vinyl group. Examples of the substituent for R ³ include a methyl group.

In the formula (1), a plurality of R ¹ are independent from each other and may be different from each other or the same. The same applies to R ² and R ³ .

  Further, m and n are the number of repeating units constituting the vinyl group-containing linear organopolysiloxane (A1) represented by the formula (1), m is an integer of 0 to 2000, and n is 1000 to 10,000. Is an integer. m is preferably 0 to 1000, and n is preferably 2000 to 5000.

  Moreover, as a specific structure of a vinyl group containing linear organopolysiloxane (A1) represented by Formula (1), what is represented, for example by following formula (1-1) is mentioned.

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

  Furthermore, the vinyl group-containing linear organopolysiloxane (A1) contains a first vinyl group having a vinyl group content of 2 or more vinyl groups in the molecule and not more than 0.4 mol%. It contains a linear organopolysiloxane (A1-1) and a second vinyl group-containing linear organopolysiloxane (A1-2) having a vinyl group content of 0.5 to 15 mol%. Preferably there is. As raw rubber, which is a raw material of silicone rubber, a first vinyl group-containing linear organopolysiloxane (A1-1) having a general vinyl group content and a second vinyl group-containing direct polymer having a high vinyl group content By combining with the chain organopolysiloxane (A1-2), 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 the 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 A first vinyl group-containing linear organopolysiloxane (A1-1) having two or more in the molecule and containing 0.4 mol% or less, 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 a unit in which ² is a vinyl group.

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

  Further, when the first vinyl group-containing linear organopolysiloxane (A1-1) and the second vinyl group-containing linear organopolysiloxane (A1-2) are combined and blended, (A1-1) The ratio of (A1-2) to (A1-2) is not particularly limited. For example, the weight ratio of (A1-1) :( A1-2) is preferably 50:50 to 95: 5, and 80:20 to 90: 10 is more preferable.

  Each of 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 include a vinyl group-containing branched organopolysiloxane (A2) having a branched structure.

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

  The straight-chain organohydrogenpolysiloxane (B1) has a straight-chain 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 the vinyl group, the polymer is a polymer that undergoes a hydrosilylation reaction with a vinyl group contained in a component blended in the silicone rubber-based curable composition to crosslink these components.

  The molecular weight of the linear organohydrogenpolysiloxane (B1) is not particularly limited. For example, the weight average molecular weight is preferably 20000 or less, and more preferably 1000 or more and 10,000 or less.

  In addition, the weight average molecular weight of linear organohydrogenpolysiloxane (B1) can be measured by polystyrene conversion in GPC (gel permeation chromatography) which used chloroform as a developing solvent, for example.

  Moreover, it is preferable that the linear organohydrogenpolysiloxane (B1) usually has no vinyl group. Thereby, it can prevent exactly that a crosslinking reaction advances in the molecule | numerator of linear organohydrogenpolysiloxane (B1).

  As the linear organohydrogenpolysiloxane (B1) as described above, for example, those having a structure represented by the following formula (2) are preferably used.

In formula (2), R ⁴ represents 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. As a C1-C10 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. As a C1-C10 alkenyl group, a vinyl group, an allyl group, a butenyl group etc. are mentioned, for example. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

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 a methyl group, an ethyl group, and a propyl group, and among them, a methyl group is preferable. As a C1-C10 alkenyl group, a vinyl group, an allyl group, a butenyl group etc. are mentioned, for example. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

In the formula (2), the plurality of R ⁴ are independent from each other and may be different from each other or the same. The same is true for R ^5. However, at least two of the plurality of R ⁴ and R ⁵ are hydride groups.

R ⁶ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these. As a C1-C8 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group. The plurality of R ⁶ are independent from each other and may be different from each other or the same.

In addition, as a substituent of R < ⁴ >, R < ⁵ >, R < ⁶ > in Formula (2), a methyl group, a vinyl group etc. are mentioned, for example, and a methyl group is preferable from a viewpoint of preventing the crosslinking reaction in a molecule | numerator.

  Further, m and n are the number of repeating units constituting the linear organohydrogenpolysiloxane (B1) represented by the 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 of 2 to 100, and n is an integer of 2 to 100.

  In addition, linear organohydrogenpolysiloxane (B1) may be used individually by 1 type, and may be used in combination of 2 or more type.

  Since the branched organohydrogenpolysiloxane (B2) has a branched structure, it forms a region having a high crosslinking density and is a component that greatly contributes to the formation of a dense structure having a crosslinking density in the system of silicone rubber. Further, similar to the above-mentioned 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 group of the components blended in the rubber-based curable composition to crosslink these components.

  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 has no vinyl group. Thereby, it can prevent exactly that a crosslinking reaction advances in the molecule | numerator of branched organohydrogenpolysiloxane (B2).

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

Average composition formula (c)
(H _a (R ⁷ ) _3-a SiO _1/2 ) _m (SiO _4/2 ) _n
(In the 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 / 2} units)

In the 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 obtained by combining these. As a C1-C10 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

  In the 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.

In the 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. The linear organohydrogenpolysiloxane (B1) differs from the branched organohydrogenpolysiloxane (B2) in that the structure is linear or branched. The number of alkyl groups R to be bonded (R / Si) is 1.8 to 2.1 for linear organohydrogenpolysiloxane (B1), and 0.8 to 1 for branched organohydrogenpolysiloxane (B2). .7 range.

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

  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 obtained by combining these, or a hydrogen atom. As a C1-C8 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group. Examples of the substituent for R ⁷ include a methyl group.

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

  In Formula (3), “—O—Si≡” represents that Si has a branched structure spreading in three dimensions.

  In addition, a branched organohydrogenpolysiloxane (B2) may be used individually by 1 type, and may be used in combination of 2 or more type.

  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, the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolypolyol with respect to 1 mol of the vinyl group in the vinyl group-containing linear organopolysiloxane (A1). The amount of the total amount of hydride groups of siloxane (B2) is preferably 0.5 to 5 mol, and 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 made.

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

  Although it does not specifically limit as a silica particle (C), For example, fumed silica, baked silica, precipitated silica, etc. are used. These may be used alone or in combination of two or more.

Silica particles (C) are, for example, it is preferable that the specific surface area by the BET method, for example, 50 to 400 m ² / g, and more preferably 100 to 400 m ² / g. Moreover, it is preferable that the average primary particle diameter is 1-100 nm, for example, and it is more preferable that it is about 5-20 nm.

  By using the silica particles (C) within the range of the specific surface area and the average particle diameter, it is possible to improve the hardness and mechanical strength of the formed silicone rubber, particularly the tensile strength.

<< Silane coupling agent (D) >>
The silicone rubber-based curable composition of the present embodiment can contain a silane coupling agent (D).
The silane coupling agent (D) can have a hydrolyzable group. The surface modification of the silica particles (C) can be carried out by hydrolyzing the hydrolyzable groups with water to form hydroxyl groups, which undergo a dehydration condensation reaction with the hydroxyl groups on the surface of the silica particles (C).

  Moreover, this silane coupling agent (D) can contain the silane coupling agent which has a hydrophobic group. Thereby, since this hydrophobic group is imparted to the surface of the silica particles (C), the cohesive force of the silica particles (C) is reduced in the silicone rubber-based curable composition and thus in the silicone rubber (hydrogen due to silanol groups). As a result, the dispersibility of the silica particles in the silicone rubber-based curable composition is estimated to be improved. Thereby, the interface of a silica particle and a rubber matrix increases, and the reinforcement effect of a silica particle increases. Furthermore, when the rubber matrix is deformed, it is presumed that the sliding property of the silica particles in the matrix is improved. And the mechanical strength (for example, tensile strength, tear strength, etc.) of the silicone rubber by a silica particle (C) improves by the improvement of the dispersibility of silica particle (C), and the improvement of slipperiness.

  Furthermore, the silane coupling agent (D) can contain a silane coupling agent having a vinyl group. Thereby, a vinyl group is introduce | transduced into the surface of a silica particle (C). Therefore, when the silicone rubber-based curable composition is cured, that is, the vinyl group of the vinyl group-containing organopolysiloxane (A) and the hydride group of the organohydrogenpolysiloxane (B) undergo a hydrosilylation reaction. When the network (crosslinked structure) is formed, the vinyl group of the silica particles (C) is also involved in the hydrosilylation reaction with the hydride group of the organohydrogenpolysiloxane (B). Silica particles (C) are also taken in. Thereby, low hardness and high modulus of the formed silicone rubber can be achieved.

  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.

  As a silane coupling agent (D), what is represented by following formula (4) is mentioned, for example.

_{Y n -Si- (X) 4-} n ··· (4)
In said formula (4), n represents the integer of 1-3. Y represents a functional group of any one having a hydrophobic group, a hydrophilic group or a vinyl group. When n is 1, it is a hydrophobic group, and 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 that is a combination thereof, and examples thereof include a methyl group, an ethyl group, a propyl group, and a phenyl group. A methyl group is preferred.

Examples of the hydrophilic group include a hydroxyl group, a sulfonic acid group, a carboxyl group, and a carbonyl group. Among these, a hydroxyl group is particularly preferable. The hydrophilic group may be included as a functional group, but is preferably not included from the viewpoint of imparting hydrophobicity to the silane coupling agent (D).

Furthermore, examples of the hydrolyzable group include an alkoxy group such as a methoxy group and an ethoxy group, a chloro group, and a silazane group. Among them, a silazane group is preferable because of its high reactivity with the silica particles (C). Incidentally, those having a silazane group as hydrolyzable groups, the characteristics of its structure the formula (4) in the structure of (Y _n -Si-) comes to have two.

  Specific examples of the silane coupling agent (D) represented by the above formula (4) include, for example, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, having a hydrophobic group as a functional group. Alkoxysilanes such as ethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane; methyltrichlorosilane Chlorosilanes such as dimethyldichlorosilane, trimethylchlorosilane, and phenyltrichlorosilane; hexamethyldisilazane, and methacryloxypropyltriethoxysilane having a vinyl group as a functional group. , Alkoxysilanes such as methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane; vinyltrichlorosilane, vinylmethyl Chlorosilanes such as dichlorosilane; divinyltetramethyldisilazane can be mentioned. Among them, considering the above description, hexamethyldisilazane having a hydrophobic group and divinyltetramethyl having a vinyl group are particularly preferable. Disilazane is preferred.

<< Platinum or platinum compound (E) >>
The silicone rubber-based curable composition of the present 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 the platinum or platinum compound (E), known ones can be used, for example, platinum black, platinum supported on silica or carbon black, chloroplatinic acid or an alcohol solution of chloroplatinic acid, chloride Examples thereof include complex salts of platinum acid and olefins, complex salts of chloroplatinic acid and vinyl siloxane, and the like.

  In addition, platinum or a platinum compound (E) may be used individually by 1 type, and may be used in combination of 2 or more type.

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

  Water (F) is a component that functions as a dispersion medium for dispersing each component contained in the silicone rubber-based curable composition and 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 this embodiment may contain a known additive component blended in the silicone rubber-based curable composition in addition to the components (A) to (F). Examples thereof 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 the silicone rubber-based curable composition, the content ratio of each component is not particularly limited, but is set as follows, for example.

  In the present 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 with respect to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A). Or less, more preferably 35 parts by weight or less. Thereby, the balance of tear strength and tensile permanent strain can be achieved. Moreover, although the lower limit of content of a silica particle (C) is not specifically limited with respect to 100 weight part of total amounts of vinyl group containing organopolysiloxane (A), For example, 20 weight part or more may be sufficient.

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

  Specifically, the content of the organohydrogenpolysiloxane (B) is, for example, relative to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A) and 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. There exists a possibility that more effective hardening reaction can be performed because content of (B) exists in the said range.

  The content of platinum or the platinum compound (E) means a catalytic amount and can be appropriately set. Specifically, the vinyl group-containing organopolysiloxane (A), silica particles (C), silane coupling agent ( The amount of platinum group metal in this component is 0.01 to 1000 ppm by weight, and preferably 0.1 to 500 ppm with respect to the total amount of D). By making content of platinum or a platinum compound (E) more than the said lower limit, the silicone rubber composition obtained can fully be hardened. By making content of platinum or a platinum compound (E) below the said upper limit, the cure rate of the silicone rubber composition obtained can be improved.

  Furthermore, when it contains water (F), the content can be set as appropriate. Specifically, for example, 10 to 100 parts by weight with respect to 100 parts by weight of the silane coupling agent (D). Is preferable, and the range of 30 to 70 parts by weight is more preferable. Thereby, reaction with a silane coupling agent (D) and a silica particle (C) can be advanced more reliably.

<Method for producing silicone rubber>
Next, the manufacturing method of the silicone rubber of this embodiment is demonstrated.
As a method for producing the silicone rubber of the present embodiment, a silicone rubber can be obtained by preparing a silicone rubber-based curable composition and curing the silicone rubber-based curable composition.
Details will be described below.

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

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

  The 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). Thereby, the dispersibility of the silica particles (C) in the vinyl group-containing organopolysiloxane (A) is further improved.

  Moreover, when obtaining this kneaded material, you may make it add water (F) to the kneaded material of each component (A), (C), and (D) as needed. Thereby, reaction with a silane coupling agent (D) and a silica particle (C) can be advanced more reliably.

  Furthermore, kneading of the components (A), (C), and (D) is preferably performed through a first step of heating at the first temperature and a second step of heating at the 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) By-products generated by the reaction can be reliably removed from the kneaded product. Thereafter, if necessary, the component (A) may be added to the obtained kneaded product and further kneaded. Thereby, the familiarity of the components of the kneaded product can be improved.

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

  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.

  Furthermore, the time of the first step is preferably, for example, about 0.3 to 1.5 hours, and 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, and more preferably about 1.0 to 2.0 hours.

  By setting the first step and the second step as described above, the effect can be obtained more remarkably.

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

  When kneading each of the components (B) and (E), the kneaded material prepared in advance in the step [1] and the organohydrogenpolysiloxane (B) were prepared in the step [1]. It is preferable to knead the kneaded material and platinum or the platinum compound (E), and then knead each kneaded material. As a result, the components (A) to (E) are surely contained in the silicone rubber-based curable composition without causing a reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B). Can be dispersed.

  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, for example, about 5 minutes to 1 hour, and more preferably about 10 to 40 minutes.

  In the step [1] and the step [2], by setting the temperature within the above range, the progress of the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) is more accurately performed. Can be prevented or suppressed. Moreover, in said process [1] and said process [2], by making kneading time into the said range, each component (A)-(E) can be more reliably disperse | distributed in a silicone rubber-type curable composition. Can do.

  The kneading apparatus used in each of the steps [1] and [2] is not particularly limited, and for example, a kneader, two rolls, a Banbury mixer (continuous kneader), a pressure kneader, or the like can be used.

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

[3] Next, a 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 is, for example, heated (primary curing) at 100 to 250 ° C. for 1 to 30 minutes, and then post-baked (secondary) at 200 ° C. for 1 to 4 hours. Curing).
By passing through the above processes, the silicone rubber of this embodiment is obtained.

  As a result of investigation by the present inventors, the following findings were obtained. It has been found that when the amount of filler in the silicone rubber is reduced, the hardness can be reduced and the tensile stress can be reduced, but on the other hand, the tear strength is lowered and the durability of the silicone rubber is lowered.

  Therefore, as a result of intensive studies, by appropriately selecting a resin composition such as vinyl group-containing organopolysiloxane (A), it is possible to control the uneven distribution of crosslink density and crosslink structure, and to reduce low stress and low hardness in a wide range of strain. It has been found that the tear strength of silicone rubber can be increased while realizing it. It was also found that the tensile strength of silicone rubber can be increased. Although the detailed mechanism is not clear, the combined use of high vinyl group-containing organopolysiloxane and low vinyl group-containing vinyl group-containing organopolysiloxane can control the uneven distribution of the crosslinked structure. It is thought that strength can be increased. Thus, the fracture energy of the silicone rubber can be increased by increasing the tear strength while maintaining other physical properties.

  Further, in this embodiment, for example, by reducing the filler amount, the tensile stress at the initial strain is reduced, while the crosslink density of the resin and the uneven distribution of the crosslinked structure are controlled, thereby the tensile stress at the later strain. Can be reduced.

  In the present embodiment, for example, by appropriately selecting the type and amount of each component contained in the silicone rubber-based curable composition, the method for preparing the silicone rubber-based curable composition, the method for producing the silicone rubber, and the like, It is possible to control the hysteresis loss change rate, tensile stress, breaking energy, tensile strength, tear strength, and hardness. Among these, for example, a combination of a low vinyl group-containing linear organopolysiloxane (A1-1) and a high vinyl group-containing linear organopolysiloxane (A1-2), a vinyl having a vinyl group at the terminal Controlling uneven distribution of resin crosslink density and crosslink structure by using group-containing organopolysiloxane (A), addition timing of vinyl group-containing organopolysiloxane (A), blending ratio of silica particles (C) The reaction between the silane coupling agent (D) and the silica particles (C), such as surface modification with the silane coupling agent (D) of the silica particles (C) and addition of water, proceeds more reliably. Are listed as factors for bringing the rate of change in hysteresis loss, tensile stress, breaking energy, tensile strength, tear strength, and hardness into a desired numerical range. That.

In the present embodiment, the upper limit of the content of silica particles (C) may be, for example, 55 parts by weight or less, preferably 53 parts by weight with respect to 100 parts by weight of the total amount of vinyl group-containing organopolysiloxane (A). It may be less than or equal to parts by weight, more preferably less than or equal to 50 parts by weight. Thereby, the balance of tear strength and tensile permanent strain can be achieved. Further, the lower limit of the content of the silica particles (C) is not particularly limited with respect to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A), but may be, for example, 10 parts by weight or more, and 20 parts by weight. That's all.
Here, with respect to 100 parts by weight of the vinyl group-containing organopolysiloxane (A), the content of the silica particles (C) is X (parts by weight), and the cured product of the silicone-based cured composition is defined in JIS K6253. When the durometer hardness A is Y, the filler amount / hardness is, for example, less than 1, preferably 0.95 or less, more preferably 0.91 or less when expressed by X / Y. It can be. The reason why X (filler amount) / Y (hardness) is less than 1, for example, is not clear, but can be cited as an element for setting the hysteresis loss change rate in a desired numerical range.

  Also, in the resin movable member of the present embodiment, | ΔE5 / ΔE2 | × 100, which is the fluctuation ratio of the fifth hysteresis loss to the second hysteresis loss, is H3 (%). At this time, H3 × (X / Y) may be, for example, 63 or less, preferably 60 or less, and more preferably 58 or less. Thereby, the resin movable member excellent in durability at the time of repeated deformation can be realized. On the other hand, the lower limit value of | ΔE5 / ΔE2 | × 100 is not particularly limited, but may be, for example, 10 or more, or 20 or more.

  As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail with reference to an Example, this invention is not limited to description of these Examples at all.

The raw material components used in Examples and Comparative Examples shown in Table 1 are shown below.
(Vinyl group-containing organopolysiloxane (A))
Low vinyl group-containing linear organopolysiloxane (A1-1a): In-chain vinyl group-containing dimethylpolysiloxane synthesized by Synthesis Scheme 1 (in the structure represented by formula (1-1), only R ² (in-chain) is (Vinyl structure)
Low vinyl group-containing linear organopolysiloxane (A1-1b): terminal vinyl group-containing dimethylpolysiloxane synthesized by Synthesis Scheme 2 (in the structure represented by formula (1-1), only R ¹ (terminal) is a vinyl group Is a structure)
High vinyl group-containing linear organopolysiloxane (A1-2a): vinyl group-containing dimethylpolysiloxane synthesized by Synthesis Scheme 3 (in the structure represented by formula (1-1), R ¹ and R ² are vinyl groups) Construction)

(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), manufactured by Nippon Aerosil Co., Ltd., “AEROSIL 300”

(Silane coupling agent (D))
Silane coupling agent (D-1): Hexamethyldisilazane (HMDZ), manufactured by Gelst, “HEXAMETHY LDISILAZANE (SIH6110.1)”
Silane coupling agent (D-2): Divinyltetramethyldisilazane, manufactured by Gelst, “1,3-DIVINYLTETRAMETHYLDISILAZAN (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 (A1-1a)]
A low vinyl group-containing linear organopolysiloxane (A1-1a) was synthesized according to the following formula (6).
That is, to a 300 mL separable flask having a cooling tube and a stirring blade substituted with Ar gas, 74.7 g (252 mmol) of octamethylcyclotetrasiloxane, 2,4,6,8-tetramethyl 2,4,6,8- 0.086 g (0.25 mmol) of tetravinylcyclotetrasiloxane and 0.1 g of potassium siliconate were added, the temperature was raised, and the mixture was stirred at 120 ° C. for 30 minutes. 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 hexamethyldisiloxane was added, and the mixture was further stirred at 155 ° C. for 4 hours.
Further, after 4 hours, the mixture was diluted with 250 mL of toluene and then washed with water three times. The washed organic layer was washed several times with 1.5 L of methanol, and purified by reprecipitation to 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 (A1-1a) (Mn = 2,5 × 10 ⁵ , Mw = 5,0 × 10 ^5). ). The vinyl group content calculated by H-NMR spectrum measurement was 0.18 mol%.

[Synthesis Scheme 2: Synthesis of low vinyl group-containing linear organopolysiloxane (A1-1b)]
In the synthesis step (A1-1a), 2,4,6,8-tetramethyl 2,4,6,8-tetravinylcyclotetrasiloxane is not used and 1,3-divinyl is used instead of hexamethyldisiloxane. A low vinyl group-containing linear organopolysiloxane according to the following formula (7) in the same manner as in the synthesis step (A1-1a) except that 0.1 g (0.6 mmol) of tetramethyldisiloxane was used. (A1-1b) was obtained. (Mn = 2, 2 × 10 ⁵ , Mw = 4, 8 × 10 ⁵ ). Moreover, vinyl group content computed by H-NMR spectrum measurement was 0.04 mol%.

[Synthesis Scheme 3: Synthesis of High Vinyl Group-Containing Linear Organopolysiloxane (A1-2a)]
In the synthesis step of (A1-1a), 0.86 g (2.5 mmol) of 2,4,6,8-tetramethyl 2,4,6,8-tetravinylcyclotetrasiloxane was used, By using the same procedure as the synthesis step (A1-1a) except that 0.1 g (0.6 mmol) of 1,3-divinyltetramethyldisiloxane was used instead of siloxane, A group-containing linear organopolysiloxane (A1-2a) was synthesized. (Mn = 2, 3 × 10 ⁵ , Mw = 5, 0 × 10 ⁵ ). The vinyl group content calculated by H-NMR spectrum measurement was 0.93 mol%.

(Preparation of silicone rubber-based curable composition)
In Examples and Comparative Examples, silicone rubber-based curable compositions were prepared as follows. First, a mixture of 95% vinyl group-containing organopolysiloxane (A), silane coupling agent (D), and water (F) at a ratio shown in Table 1 was previously kneaded, and then silica particles (C) were mixed into the mixture. Was further kneaded to obtain a kneaded product (silicone rubber compound).
Here, the kneading after the addition of the silica particles (C) includes the first step of kneading for 1 hour under the condition of 60 to 90 ° C. in a nitrogen atmosphere for the coupling reaction, and the removal of the by-product (ammonia). Therefore, the second step of kneading for 2 hours under the condition of 160 to 180 ° C. in a reduced-pressure atmosphere is carried out, and then cooled, and the remaining 5% of the vinyl group-containing organopolysiloxane (A) is added twice. Add in portions and knead for 20 minutes.
Subsequently, to 100 parts by weight of the obtained kneaded material (silicone rubber compound), organohydrogenpolysiloxane (B) and platinum or platinum compound (E) were added at a ratio shown in Table 1, and kneaded with a roll. A silicone rubber-based curable composition was obtained.

  Hereafter, the following evaluation was performed about the obtained silicone rubber-type curable composition of each Example and each comparative example. The evaluation results are shown in Table 1.

(Production of silicone rubber)
The obtained silicone rubber-based curable composition was pressed at 150 ° C. and 10 MPa for 20 minutes to form a sheet and to be primarily cured. Subsequently, it was heated at 200 ° C. for 4 hours and secondarily cured. Thus, a sheet-like silicone rubber (cured product of a silicone rubber-based curable composition) having a predetermined thickness shown in Table 1 was obtained. The following evaluation was performed on the obtained sheet-like silicone rubber. The evaluation results are shown in Table 1. Tensile strength and elongation at break were measured using three samples, and three average values were used as measured values. Moreover, about tear strength, it carried out with five samples and made five average values into the measured value. Furthermore, about hardness, it measured by n = 5 with each sample using 2 samples, and made the average value of 10 measurements into the measured value. The average value is shown in Table 1 for each.

(Measurement method of hysteresis loss)
Hysteresis loss was calculated from the measurement values obtained by the following stretching operation based on the following calculation method.
[Extension operation]
As shown in FIG. 1A, a dumbbell-shaped test piece 10 was produced using the sheet-like silicone rubber obtained by producing the silicone rubber.
Next, as shown in FIG. 1B, in accordance with JIS K6251 (2004), the test piece 10 is stretched at a constant speed (1000 mm / min) from a displacement amount of 0% to 500%, and thereafter The stretching operation of shrinking at a constant speed (1000 mm / min) from the displacement amount of 500% to 0% by the removal force was repeated five times continuously, and the stress applied to the test piece 10 was measured at room temperature of 25 ° C.
This stretching operation test was performed N times (N = 3), and an average value was adopted.
Testing machine: Autograph AG5kNX (manufactured by Shimadzu Corporation, “Model No. AG-5kNX”)
Initial value: 60 mm (distance between chucks), 0% elongation rate elongation: 360 mm (distance between chucks), 500% elongation rate elongation rate: 1000 mm / min Elongation time: 36 seconds / 1 cycle (1 cycle is the initial value → When expanding → initial value)

[Calculation method of hysteresis loss]
Hysteresis loss is the Nth test force-stroke curve obtained from the Nth stretching operation (where test force [N] is the stress when the test piece 10 is pulled, and the stroke [mm ] From the area (having the dimension of energy) obtained by integrating the distance of pulling the test piece 10, the energy EN _UP (mJ) at the time of extension, and the energy EN _DOWN (mJ) at the time of force removal Was calculated, and the hysteresis loss ΔEN (mJ) during the N-th extension operation was defined as | EN _UP −EN _DOWN |. However, N is an integer of 1-5.

  Here, the hysteresis loss during the first extension operation was ΔE1, the hysteresis loss during the second extension operation was ΔE2, and the hysteresis loss during the fifth extension operation was ΔE5. In addition, assuming that | ΔE2 / ΔE1 | × 100, which is the fluctuation ratio of the second hysteresis loss to the first hysteresis loss, is H1 (%), it is the fluctuation ratio of the fifth hysteresis loss to the first hysteresis loss | ΔE5 / ΔE1 | × 100 is H2 (%), and | ΔE5 / ΔE2 | × 100, which is the fluctuation ratio of the fifth hysteresis loss to the second hysteresis loss, is H3 (%).

(Elongation at break)
Using the obtained sheet-like silicone rubber, a dumbbell-shaped No. 3 test piece was prepared according to JIS K6251 (2004), and the elongation at break of the obtained dumbbell-shaped No. 3 test piece at room temperature of 25 ° C. Was measured. The elongation at break was calculated as [movement distance between chucks (mm)] ÷ [distance between initial chucks (60 mm)] × 100. The unit is%.

(Tensile stress)
Using the obtained sheet-like silicone rubber, in accordance with JIS K6251 (2004), a dumbbell-shaped No. 3 test piece was prepared, and the obtained dumbbell-shaped No. 3 test piece at a room temperature of 25 ° C. It was measured stress _{M 100} tensile at 100% elongation. The unit is MPa.

(Tensile strength)
Using the obtained sheet-like silicone rubber, a dumbbell-shaped No. 3 test piece was produced according to JIS K6251 (2004), and the tensile strength of the obtained test piece at room temperature of 25 ° C. was measured. The unit is MPa. This tensile strength is indicated as S (MPa) in the table.

(Tear strength)
Using the obtained sheet-like silicone rubber, a crescent-type test piece was prepared according to JIS K6252 (2001), and the tear strength of the obtained crescent-type test piece at room temperature of 25 ° C. was measured. The unit is N / mm.

(Hardness: Durometer hardness A)
Six sheets of the obtained sheet-like silicone rubber were laminated to prepare a test piece. The type A durometer hardness was measured with respect to the obtained test piece in accordance with JIS K6253 (1997) at a room temperature of 25 ° C.

<Repetitive deformation test>
A cylindrical member having a thickness of 1 mm and an inner diameter of 5 mm, cured at 170 ° C. for 5 minutes and at 200 ° C. for 4 hours, using the silicone rubber-based curable composition obtained in each example and each comparative example. (Tube) was created. A test was conducted in which the obtained cylindrical member was connected to a tube joint (As One Co., Ltd .: quick mold, model number S, connecting tube inner diameter φ3 / 4/5). Desorption of the tubular member to the tube joint was repeated 4 times. After connecting the tube joint and the tubular member for the fifth time, water was allowed to flow through the tubular member, and the presence or absence of water leakage from the connecting portion was confirmed. The case where the tube did not crack at the time of attachment to and removal from the tubular member was rated as ◎, the case where the tube had a crack of 2 mm or less was marked as ◯, and the case where the tube was cracked at 2 mm or more was marked as x. When water flowed after connecting the tubular member of the fifth tube joint, the case where there was no water leakage from the connection part was marked with ○, and the case where water leakage occurred was marked with ×.

  As mentioned above, in the resin-made movable member obtained with the silicone rubber-type curable composition of Examples 1-8, compared with Comparative Examples 1-3, durability is high with mechanical strength also at the time of repeated use. Therefore, it turned out that these balance is excellent. Therefore, it turned out that the resin-made movable member of each Example is suitable as a movable member which comprises the movable part of various instruments and apparatuses.

  As described above, the present invention has been described more specifically based on the embodiments. However, these are exemplifications of the present invention, and various configurations other than the above can be adopted.

10 test pieces

Claims (8)

The following stretching operation is repeated 5 times, the hysteresis loss at the first stretching operation is ΔE1, the hysteresis loss at the second stretching operation is ΔE2, and the second hysteresis with respect to the first hysteresis loss. The loss ratio | ΔE2 / ΔE1 | × 100 is defined as H1 (%).
When the tensile strength measured in accordance with JIS K6251 (2004) is S (MPa),
A resin movable member in which H1 is 25 or less and H1 × S is 125 or more and 400 or less.
(Extension operation)
The stretching operation is an operation in which the dumbbell test piece is stretched from a displacement amount of 0% to 500% at a room temperature of 25 ° C. and a stretching speed of 1000 mm / min, and then contracted from a displacement amount of 500% to 0% by a removal force. . The resin movable member according to claim 1,
When the hysteresis loss at the time of the fifth extension operation is ΔE5, and the variation ratio of the fifth hysteresis loss to the first hysteresis loss | ΔE5 / ΔE1 | × 100 is H2 (%),
A resin movable member having H2 of 15 or less and H2 × S of 85 to 300. The resin movable member according to claim 1 or 2,
A resin movable member in which | ΔE5 / ΔE2 | × 100, which is the fluctuation ratio of the fifth hysteresis loss to the second hysteresis loss, is 80% or less. The resin movable member according to any one of claims 1 to 3,
A resin movable member having a tear strength measured in accordance with JIS K6252 (2001) of 25 N / mm or more. The resin movable member according to any one of claims 1 to 4,
The resin movable member whose durometer hardness A prescribed | regulated based on JISK6253 (1997) is 10-80. The resin movable member according to any one of claims 1 to 5,
A resin movable member having an elongation at break measured in accordance with JIS K6251 (2004) of 200% to 1500%. The resin movable member according to any one of claims 1 to 6,
A resin movable member containing an inorganic filler.   A structure comprising the resin movable member according to any one of claims 1 to 7.

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