JP2022178845A - Manufacturing method for rubber composite - Google Patents

Abstract

To provide a manufacturing method for a rubber composite where a first member of silicone rubber and a second member of non-silicone rubber are rigidly compounded.SOLUTION: In a manufacturing method for a rubber composite where a first member of silicone rubber and a second member of non-silicone rubber are compounded, a non-crosslinked product of silicone rubber is crosslinked at a first crosslinking condition of a prescribed temperature and a prescribed time to form the first member. Surface treatment by which a polar functional group is added to a composition planned surface between the first member and the second member is conducted. A non-crosslinked product of non-silicone rubber is given to the composition planned surface subjected to the surface treatment, and the non-crosslinked product of non-silicone rubber is crosslinked at a second crosslinking condition of a prescribed temperature and a prescribed time to form the second member, then the second member is compounded with the first member.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a method for producing a rubber composite.

There are various composites in which a plurality of members made of different materials are combined. For example, Patent Literature 1 discloses a sealing material in which a rubber O-ring and a resin backup ring are combined. Patent Document 2 discloses a gasket in which a rubber member and a metal member are laminated and combined with an adhesive. Patent Document 3 discloses a composite material laminate obtained by joining a first composite material obtained by curing a first prepreg laminate containing a silicone rubber base material and a second composite material obtained by curing a second prepreg laminate. It is

JP 2020-180697 A JP 2018-176435 A WO2021/010028

An object of the present invention is to provide a method for producing a rubber composite in which a first member made of silicone rubber and a second member made of non-silicone rubber are firmly combined.

The present invention relates to a method for producing a rubber composite in which a first member of silicone rubber and a second member of non-silicone rubber are combined, wherein the uncrosslinked product of silicone rubber is heated to a first temperature for a predetermined time at a predetermined temperature. The first member is formed by cross-linking under cross-linking conditions, the surface of the first member to be combined with the second member is subjected to surface treatment for imparting a polar functional group, and the first member is subjected to the surface treatment. The uncrosslinked material of the non-silicone rubber is applied to the composite surface, and the uncrosslinked material of the non-silicone rubber is crosslinked under a second crosslinking condition of a predetermined temperature and a predetermined time to form the second member. and the second member is combined with the first member.

According to the present invention, the first member and the second member are strengthened by performing a surface treatment for imparting a polar functional group to the surface of the silicone rubber first member to be combined with the non-silicone rubber second member. can be combined into

FIG. 2 is a plan view of a rubber composite sealing material manufactured by the method according to the embodiment. FIG. 1B is a cross-sectional view taken along line IB-IB in FIG. 1A; FIG. 4 is a first explanatory view of the method for manufacturing the sealing material according to the embodiment; FIG. 3B is a second explanatory view of the method for manufacturing the sealing material according to the embodiment; FIG. 11 is a third explanatory view of the method for manufacturing the sealing material according to the embodiment; FIG. 10 is a fourth explanatory diagram of the method for manufacturing the sealing material according to the embodiment;

Hereinafter, embodiments will be described in detail.

FIGS. 1A and 1B show a rubber composite sealing material 10 manufactured by a method according to an embodiment. This sealing material 10 is a so-called O-ring that is assembled in, for example, a semiconductor manufacturing apparatus and used in a low-temperature atmosphere.

The sealing material 10 includes a first member 11 on the inner peripheral side and a second member 12 on the outer peripheral side. The first member 11 is formed to have a cross-sectional shape in which a large-diameter semicircle on the inner peripheral side and a small-diameter semicircle on the outer peripheral side are concentrically coupled. The second member 12 is formed in a semicircular arc cross-sectional shape that is open on the inner peripheral side. The outer diameter of the arc of the second member 12 is the same as the large diameter semicircle on the inner peripheral side of the first member 11, and the inner diameter of the arc is almost the same as the small diameter semicircle on the outer peripheral side of the first member 11. are identical. In the sealing material 10, a protrusion extending in the circumferential direction of a small-diameter semicircle in cross section on the outer peripheral side of the first member fits into a groove extending in the circumferential direction of the small-diameter semicircle on the inner peripheral side of the second member 12. Together, the first member 11 and the second member 12 are adhered and combined.

The first member 11 is made of silicone rubber. Polymer components of silicone rubber include, for example, vinylmethylsilicone (VMQ) and phenylmethylsilicone (PMQ). The polymer component of the silicone rubber is preferably phenylmethylsilicone (PMQ) from the viewpoint of excellent low temperature resistance.

The TR10 of the silicone rubber forming the first member 11 is preferably −60° C. or lower from the viewpoint of excellent low temperature resistance. This TR10 is measured based on JIS K6261:2006. The rubber hardness of the silicone rubber forming the first member 11 measured with a type A durometer at a standard test temperature is, for example, 50 or more and 80 or less. This rubber hardness is measured based on JIS K6253-3:2012. The 100% stress at the standard test temperature of the silicone rubber forming the first member 11 is, for example, 1.0 MPa or more. This 100% stress is measured based on JIS K6251:2010.

The second member 12 is made of non-silicone rubber. Examples of non-silicone rubber polymer components include fluororubbers and ethylene propylene rubbers. Examples of fluororubbers include copolymers of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) (binary FKM), vinylidene fluoride (VDF), hexafluoropropylene (HFP) and tetrafluoroethylene (TFE). ) and the like (ternary FKM). The polymer component of the non-silicone rubber forming the second member 12 is preferably fluororubber, more preferably binary FKM, from the viewpoint of excellent sealing properties.

The non-silicone rubber forming the second member 12 preferably has a gas permeability coefficient at standard temperature of 3.0×10 ⁻¹² mol·m/(m ² ·s·Pa) or less, more preferably 1.0. ×10 ⁻¹² mol·m/(m ² ·s·Pa) or less. This gas permeability coefficient is measured based on JIS K6275-1:2009. The gas permeability coefficient at standard temperature of the non-silicone rubber forming the second member 12 is lower than the gas permeability coefficient at standard temperature of the silicone rubber forming the first member 11 from the viewpoint of excellent sealing performance. preferable.

The hardness of the non-silicone rubber forming the second member 12 at a standard test temperature measured with a type A durometer is, for example, 60 or more and 80 or less. The 100% stress at the standard test temperature of the non-silicone rubber forming the second member 12 is, for example, 3.0 MPa or more.

In the method of manufacturing the sealing material 10 (rubber composite) having the above configuration according to the embodiment, first, the first member 11 is formed. Specifically, for example, as shown in FIG. 2A, a cavity _C1 having the shape of the first member 11 formed in the first mold 21 is filled with an uncrosslinked material _R1 of silicone rubber, and then the mold is clamped. By press molding, the uncrosslinked product _R1 of silicone rubber is subjected to a predetermined temperature (e.g. 160 ° C to 170 ° C), a predetermined pressure (e.g. 8.0 MPa to 12.0 MPa), and a predetermined time (e.g. 5 minutes to 15 minutes) to form the first member 11 by cross-linking under the first cross-linking conditions.

The uncrosslinked product _R1 of silicone rubber preferably contains a cross-linking agent from the viewpoint of firmly combining the first member 11 and the second member 12 as described later. From the same point of view, the cross-linking agent is preferably a peroxide such as 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane. In the case of peroxide, the content of the cross-linking agent in the uncrosslinked product _R1 of silicone rubber is, for example, 0.5 parts by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the polymer component.

The uncrosslinked silicone rubber R ₁ preferably contains silica from the viewpoint of firmly combining the first member 11 and the second member 12 . Silica includes dry process silica and wet process silica. Silica is preferably dry silica from the same viewpoint. From the same viewpoint, the content of silica in the uncrosslinked product _R1 of silicone rubber is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 7 parts by mass with respect to 100 parts by mass of the polymer component. More preferably, it is 10 parts by mass or more, and from the viewpoint of storage stability, it is preferably 20 parts by mass or less, and more preferably less than 15 parts by mass.

From the viewpoint of firmly combining the first member 11 and the second member 12, the first cross-linking conditions for forming the first member 11 are conditions under which the uncrosslinked product _R1 of silicone rubber is semi-vulcanized. preferable. Specifically, the first cross-linking conditions are based on the curest test ("JIS K6300-2: 2001 Part 2: Determination of vulcanization properties by vibration type vulcanization tester" for uncrosslinked silicone rubber R ₁ ). ) above tC(10) and below tC(50).

Next, the first member 11 is removed from the first mold, and as shown in FIG. 2B, the surface 11a to be combined with the second member 12 is subjected to surface treatment for imparting polar functional groups.

Examples of the surface treatment for imparting polar functional groups include plasma treatment, flame treatment, corona discharge treatment, ozone spraying treatment, ultraviolet irradiation treatment, coating treatment, and silane coupling agent treatment. Plasma treatment among these is preferable for the surface treatment. Polar functional groups imparted by surface treatment typically include hydroxyl groups (OH groups) and carboxy groups (COOH groups).

From the viewpoint of firmly combining the first member 11 and the second member 12, the first member 11 is subjected to a temperature higher than the temperature condition of the first crosslinking condition (for example, 190 ° C. to 210 ° C.) before the surface treatment. Moreover, it is preferable not to perform the heat treatment for a longer time (for example, 3 to 5 hours) than the time condition, that is, the secondary cross-linking treatment.

Subsequently, the second member 12 is formed and combined with the first member 11 . Specifically, for example, as shown in FIG. 2C, the first member 11 having a surface-treated composite surface _11a is preset in a cavity C2 in the shape of the seal 10 formed in the second mold 22. At the same time, after filling the remaining space with the non-silicone rubber uncrosslinked material _R2 so as to hit the combined surface 11a of the first member 11, the mold is clamped and press-molded to remove the non-silicone rubber uncrosslinked material. The crosslinked product _R2 is crosslinked under the second crosslinking conditions of a predetermined temperature (eg, 160° C. to 170° C.), a predetermined pressure (eg, 8.0 MPa to 12.0 MPa), and a predetermined time (eg, 5 minutes to 15 minutes). A second member 12 is formed and the second member 12 is combined with the first member 11 .

From the viewpoint of firmly combining the first member 11 and the second member 12, the uncrosslinked non-silicone rubber _R2 preferably contains a cross-linking agent. From the same point of view, the cross-linking agent is preferably a peroxide such as 2,5-dimethyl-2,5-di(tert-butyloxy)hexane. When both the uncrosslinked material _R1 of the silicone rubber forming the first member 11 and the uncrosslinked material _R2 of the non-silicone rubber forming the second member 12 contain a crosslinking agent, from the same point of view, they are preferably the same. In the case of peroxide, the content of the cross-linking agent in the non-silicone rubber uncrosslinked product _R2 is, for example, 0.5 parts by mass or more and 1.5 parts by mass or less with respect to 100 parts by mass of the polymer component.

Before applying the non-cross-linked non-silicone rubber to the pre-composite surface 11a of the first member 11 which has undergone the surface treatment, as shown in FIG. 2D, an adhesive 13 is applied. It is preferably applied and dried. Examples of the adhesive 13 include commercially available rubber adhesives such as Chemlock series manufactured by Lord Corporation.

Then, the composite of the first member 11 and the second member 12 is removed from the second mold 22, placed in an oven or the like, and heated to a temperature higher than the temperature conditions of the first and second crosslinking conditions (for example, 190°C to 190°C). 210° C.) for a longer period of time (for example, 3 to 5 hours), that is, a secondary cross-linking treatment, to obtain the sealing material 10 .

According to the method of manufacturing the sealing material 10 according to the above embodiment, the surface 11a of the first member 11 made of silicone rubber to be combined with the second member 12 made of non-silicone rubber is subjected to surface treatment for imparting polar functional groups. Thereby, the first member 11 and the second member 12 can be strongly combined.

(Preparation of rubber material)
Polymer component phenylmethyl silicone (KE-186-U, manufactured by Shin-Etsu Silicone Co., Ltd.) and 2 parts by mass of a cross-linking agent (C-8 manufactured by Shin-Etsu Silicone Co., Ltd., peroxide 2,5) per 100 parts by mass of this polymer component. -Dimethyl 2,5-bis(t-butylperoxy)hexane containing about 25% by mass)) was prepared.

The TR10 of this PMQ uncrosslinked product measured according to JIS K6261:2006 was −80° C. or lower. In addition, a curest test was performed under measurement temperature conditions of 155° C. and 165° C., and tC(10), tC(50), and t(90) were measured. Table 1 shows the results.

An uncrosslinked product of binary FKM containing a binary FKM polymer component and 2 parts by mass of a peroxide of a cross-linking agent per 100 parts by mass of the polymer component (hereinafter referred to as "uncrosslinked FKM product").

(Test evaluation 1)
The uncrosslinked PMQ material was crosslinked by press molding under the first crosslinking conditions of 165° C. temperature, 10.0 MPa pressure, and 10 minutes time to form a sheet-like crosslinked PMQ material. The resulting sheet-like PMQ crosslinked product was placed in a gear oven and subjected to secondary crosslinking treatment at 200° C. for 4 hours.

The surface of the PMQ crosslinked product was wiped with alcohol and set in a chamber of a plasma generator (plasma etcher CPE-400, manufactured by Kai Semiconductor Co., Ltd.). While reducing the pressure in the chamber to 100 Pa and flowing oxygen into the chamber at 100 secm, plasma was generated at a power of 500 W to subject the surface of the sheet-like PMQ crosslinked material to plasma treatment for 10 minutes. It was confirmed that mainly hydroxyl groups were added to the surface of the PMQ crosslinked product subjected to the plasma treatment.

A sheet-like FKM uncrosslinked material is laminated on the plasma-treated surface of the PMQ crosslinked material, and it is crosslinked by press molding under the second crosslinking conditions of a temperature of 160 ° C., a pressure of 10.0 MPa, and a time of 10 minutes. to form FKM cross-links and complex with PMQ cross-links. After that, it was placed in a gear oven and subjected to secondary cross-linking treatment at 200° C. for 4 hours to prepare a plate-shaped test piece for peel test with a width of 25 mm. This test piece for peel test was designated as Example 1.1.

5 parts by mass, 7 parts by mass, 10 parts by mass, 15 parts by mass, and 20 parts by mass of dry silica (Aerosil 200, manufactured by Nippon Aerosil Co., Ltd.) was added to the PMQ uncrosslinked material with respect to 100 parts by mass of the polymer component. A test piece for a peeling test having the same configuration as that of Examples 1 and 1 except for the above was produced, and designated as Examples 1 and 2 to Examples 1 and 6, respectively. Also, a test piece for a peel test having the same configuration as that of Example 1.1 except that the PMQ crosslinked product was not subjected to plasma treatment was produced and designated as Comparative Example 1.

For each of Examples 1.1 to 1.6 and Comparative Example 1, a T-shaped peel test was performed at a peel speed of 100 mm/min based on JIS K6256:2013, and the maximum peel force and average peel force were measured. At the same time, the peeled state after peeling was visually confirmed. Table 2 shows the results.

According to Table 2, Examples 1 and 1 in which plasma treatment was performed have higher maximum peel strength and average peel strength than Comparative Example 1 in which plasma treatment is not performed, and the PMQ crosslinked product and the FKM crosslinked product are stronger. It turns out that it is complex.

Examples 1/2 to 1/6, in which the PMQ uncrosslinked product contains dry-process silica, have higher maximum peel strength and average peel strength than Example 1-1, which does not contain dry-process silica. , it can be seen that the PMQ cross-linked product and the FKM cross-linked product are strongly combined.

Comparing Examples 1 and 2 to Examples 1 and 6 in which the dry process silica content was varied, it was found that the maximum peel strength and the average peel strength tended to increase as the dry process silica content increased. However, regarding the storage stability of the PMQ uncrosslinked product, in Examples 1 and 2 and Examples 1 and 3, as in Example 1 and 1, no deterioration in adhesive performance was observed even after a storage period of 6 months. However, deterioration in adhesion performance was observed after storage for one month in Examples 1 and 4, storage for seven days in Examples 1 and 5, and storage for four days in Example 4.

(Test evaluation 2)
Example 1.1 to Example 1.6 and Comparative Example 1 except that an adhesive (manufactured by Chemlock 608 Road Co., Ltd.) was applied to the surface of the PMQ crosslinked product subjected to plasma treatment and allowed to air dry for 10 minutes. Test pieces for the peel test having the same configuration were produced, and designated as Examples 2.1 to 2.6 and Comparative Example 2, respectively.

For each of Examples 2.1 to 2.6 and Comparative Example 2, a T-shaped peel test similar to Test Evaluation 1 was performed to measure the maximum peel force and average peel force, and the peel state after peeling. was visually confirmed. Table 3 shows the results.

According to Table 3, Examples 2.1 to 2.6 using an adhesive and Comparative Example 2 correspond to Examples 1.1 to 1 not using the adhesive shown in Table 2.・Examples 2 and 3 to Examples in which the maximum peel force and average peel force are significantly higher than those of 6 and Comparative Example 1, and the content of dry process silica is 7 parts by mass or more with respect to 100 parts by mass of the polymer component In 2.6, it can be seen that the form of peeling is rubber breakage due to the synergistic effect, and the PMQ cross-linked product and the FKM cross-linked product are more firmly combined. Other tendencies are the same as test evaluation 1.

(Test evaluation 3)
A peel test test piece having the same structure as that of Examples 1 and 3 was prepared except that the sheet-shaped PMQ crosslinked material before the plasma treatment was not subjected to the secondary cross-linking treatment.

For Example 3, the same T-peel test as in Test Evaluation 1 was performed to measure the maximum peel force and average peel force, and the peeled state after peeling was visually confirmed. Table 4 shows the results.

According to Table 4, Example 3, in which the PMQ crosslinked product before plasma treatment was not subjected to secondary cross-linking treatment, had higher maximum peel strength and average peel strength than Examples 1 and 3 in which it was performed, and In terms of the form of peeling, while interfacial peeling was observed in Examples 1 and 3, it was rubber rupture, indicating that the PMQ cross-linked product and the FKM cross-linked product are firmly combined.

(Test evaluation 4)
A test piece for peel test having the same configuration as in Example 3 was prepared except that the temperature condition in the first crosslinking condition during the formation of the PMQ crosslinked product was 155 ° C. and the time condition was 15 minutes.・It was set to 1. A test piece for a peel test having the same configuration as in Example 4.1 except that the time condition in the first crosslinking condition during the formation of the PMQ crosslinked product was set to 3.5 minutes was prepared, and it was used in Example 4.2. and

Here, according to Table 1, in both Example 3 and Example 4.1, the time condition under the first crosslinking condition is longer than tC(90). On the other hand, in Examples 4 and 2, the time condition in the first cross-linking condition is tC(10) or more and tC(50) or less. That is, the first cross-linking conditions of Examples 4 and 2 are the conditions under which the PMQ uncross-linked product is semi-vulcanized.

For each of Examples 4.1 and 4.2, a T-shaped peel test was performed in the same manner as in Test Evaluation 1, the maximum peel force and average peel force were measured, and the peel state after peeling was visually confirmed. did. Table 5 shows the results.

According to Table 5, Example 4-2, in which a semi-vulcanized PMQ cross-linked product was formed, had a higher maximum peel force and average peel strength than Example 4-1, in which a fully cross-linked PMQ cross-linked product was formed. The force is remarkably high, and it can be seen that the PMQ cross-linked product and the FKM cross-linked product are strongly combined.

INDUSTRIAL APPLICABILITY The present invention is useful in the technical field of methods for producing rubber composites.

10 sealing material (rubber composite)
11 First member 111 Composite surface 12 Second member 13 Adhesive 21 First mold 22 Second mold C ₁ , C ₂ Cavity R ₁ Uncrosslinked silicone rubber R ₂ Uncrosslinked non-silicone rubber

Claims (13)

A method for producing a rubber composite in which a first member of silicone rubber and a second member of non-silicone rubber are combined,
forming the first member by cross-linking the uncross-linked material of the silicone rubber under first cross-linking conditions of a predetermined temperature and a predetermined time;
performing a surface treatment for imparting a polar functional group to the surface of the first member to be combined with the second member;
The uncrosslinked material of the non-silicone rubber is applied to the surface-treated composite surface of the first member, and the uncrosslinked material of the non-silicone rubber is subjected to second crosslinking conditions at a predetermined temperature and for a predetermined time. A method for producing a rubber composite, comprising cross-linking with to form the second member, and combining the second member with the first member. In the method for producing a rubber composite according to claim 1,
A method for producing a rubber composite, wherein the surface treatment is plasma treatment. In the method for producing a rubber composite according to claim 1 or 2,
A method for producing a rubber composite, in which an adhesive is attached to the surface of the first member to be composited, which has undergone the surface treatment, before the uncrosslinked non-silicone rubber is applied. In the method for producing a rubber composite according to any one of claims 1 to 3,
A method for producing a rubber composite, wherein TR10 of the silicone rubber is −60° C. or lower. In the method for producing a rubber composite according to any one of claims 1 to 4,
A method for producing a rubber composite, wherein the uncrosslinked silicone rubber contains a crosslinking agent. In the method for producing a rubber composite according to claim 5,
A method for producing a rubber composite, wherein the cross-linking agent contained in the uncross-linked silicone rubber is a peroxide. In the method for producing a rubber composite according to any one of claims 1 to 6,
A method for producing a rubber composite, wherein the uncrosslinked silicone rubber contains silica. In the method for producing a rubber composite according to claim 7,
A method for producing a rubber composite, wherein the silica content in the uncrosslinked silicone rubber is 20 parts by mass or less per 100 parts by mass of the polymer component. In the method for producing a rubber composite according to any one of claims 1 to 8,
The method for producing a rubber composite, wherein the first crosslinking condition is a condition of tC(10) or more and tC(50) or less in a curest test of the uncrosslinked silicone rubber. In the method for producing a rubber composite according to any one of claims 1 to 9,
The method for producing a rubber composite, wherein the first member is not subjected to heat treatment at a temperature higher than the temperature condition of the first crosslinking condition and for a longer time than the time condition before the surface treatment. In the method for producing a rubber composite according to any one of claims 1 to 10,
A method for producing a rubber composite, wherein the gas permeability coefficient of the non-silicone rubber at standard temperature is lower than the gas permeability coefficient of the silicone rubber at standard temperature. In the method for producing a rubber composite according to any one of claims 1 to 11,
A method for producing a rubber composite, wherein the non-silicone rubber is a fluororubber. In the method for producing a rubber composite according to any one of claims 1 to 11,
A method for producing a rubber composite, wherein the rubber composite is a sealing material.

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