KR100933182B1 - Manufacturing Method of Embossed Silicone Rubber Sheet - Google Patents

Abstract

The present invention relates to a method for producing an embossed silicone rubber sheet, and by using a solid silicone resin composition to flow down in the direction of gravity, a sheet having an emboss can be produced while using a straight die.

Description

MANUFACTURING METHOD OF EMBO TYPE SILICONE RUBBER SHEET}

The present invention relates to a method for producing a silicone rubber sheet having an embossed surface.

Silicone rubber sheet for sealing and cushion buffer in the space panel mounted on the outside of the display case such as LCD, PDP, LED, etc. needs to be manufactured in emboss type for excellent adhesion. There was a need for an eco-friendly manufacturing method that does not generate by-products such as gas.

The present invention is to provide a method for producing a silicone rubber sheet in which the emboss is formed on the surface using a die-shaped die using a solid silicone resin composition of a specific plasticity range.

In another aspect, the present invention is to provide a method for producing a silicon rubber sheet formed with embossing without the generation of chlorine gas using a platinum-based catalyst.

In addition, the present invention is to provide a silicone rubber sheet that can act as a sealing (sealing) and cushioning cushion in the spacer panel, etc. mounted on the outside of the display case such as LCD, PDP, LED.

The present invention for achieving the object as described above can be produced in two aspects.

First, the manufacturing method of the first aspect

a) kneading a solid silicone resin composition comprising an organopolysiloxane and a filler, a silicone oil, a crosslinking agent, and a platinum catalyst to prepare a solid composition having a plasticity of 150 to 250;

b) inserting the solid composition into a melt extruder to melt and extrude into a sheet shape;

c) naturally falling the extruded sheet in a vertical direction by gravity;

d) curing the sheet falling naturally through a vertical current collector;

e) winding the cured sheet;

It includes.

Another aspect of the manufacturing method

a) kneading a solid silicone resin composition comprising an organopolysiloxane and a filler, a silicone oil, a crosslinking agent, and a platinum catalyst to prepare a solid composition having a plasticity of 150 to 250;

b) inserting the solid composition into a melt extruder to melt and extrude into a sheet shape;

c) naturally falling the extruded sheet in a vertical direction by gravity;

d) first curing the sheet falling naturally through a vertical current collector;

e) passing the first cured sheet and passing it through a horizontal curator to cure the second cured sheet;

f) winding the cured sheet;

It includes.

Referring to the manufacturing method of the present invention in more detail with reference to the drawings, as shown in Figure 1, after passing through the melt extruder 10 extruded in the form of a sheet, immediately falling in the vertical direction in the direction of gravity without the guidance of rollers, etc. Do it. At this time, the silicone rubber flowing down vertically due to the good flow of the rubber, the speed of the upper and lower parts of the rubber that is vertically lowered due to the acceleration of gravity changes, thereby forming emboss on the surface. In order to cure the sheet is formed so as to pass through the vertical vulcanizer 20 to cure, the thus prepared embossed silicone rubber sheet is wound and stored in a roll form in the winder (40). Here, the vertical vulcanizer is a device that hardens the silicone rubber by applying heat, and means a case in which the sheet is transferred in the vertical direction.

In addition, as shown in Figure 2, the silicone rubber sheet passing through the vertical vulcanizer 20 is passed through the horizontal vulcanizer 30 installed in the horizontal direction again by secondary vulcanization, so that physical properties such as hardness, tension, embossing, etc. More uniform silicone rubber sheets can be produced. The embossed silicone rubber sheet thus prepared is wound and stored in roll form in the winder 40. Here, the horizontal vulcanizer is a device that hardens the silicone rubber by applying heat of a lower temperature than the vertical vulcanizer, and means a case of transferring in the horizontal direction.

Next, the manufacturing method of this invention is demonstrated more concretely.

First, a solid silicone resin composition comprising an organopolysiloxane and a filler, a silicone oil, a crosslinking agent, and a platinum catalyst is kneaded to prepare a solid composition having a plasticity of 150 to 250. In this case, the kneading temperature is preferably 70 to 170 ° C., since the kneading temperature can be uniformly prepared. In the present invention, the plasticity of the solid composition is 150 to 250, more preferably only if it is included in the range of 180 to 200 can produce a silicone rubber sheet having an embossed surface formed in the object of the present invention.

The solid silicone resin composition for achieving the plasticity range is 55 to 85% by weight of organopolysiloxane having a weight average molecular weight of 200,000 to 450,000, 10 to 40% by weight of filler, 0.01 to 5% by weight of silicone oil, and 0.1 to 5% of crosslinking agent. 5 wt%, and 0.1-5 wt% of a platinum catalyst. In addition, if necessary, the solid silicone resin composition may further include a release agent of 0.01 to 5% by weight, thereby improving mold release properties.

In the present invention, the organopolysiloxane is polymethylvinylsiloxane, methylvinylsiloxane-dimethylsiloxane copolymer, dimethylvinylsiloxy-terminated dimethylsiloxane, dimethylvinyl siloxy-terminated dimethyl siloxane, dimethylvinyl siloxy-terminated dimethylsiloxane-methylphenyl Siloxane copolymers, trimethylsiloxy-terminated dimethylsiloxane-methylvinylsiloxane copolymers, trimethylsiloxy-terminated dimethylsiloxane-methylphenyl siloxane-methylvinylsiloxane copolymers, and the like. It is preferable to use a molecular weight range of 200,000 to 450,000 weight average molecular weight, it is not preferable when using a polymer having less than 200,000 or more than 450,000 because it is outside the range of hardness and plasticity of the produced silicone resin.

More preferably, the organopolysiloxane may be prepared by mixing polymethylvinylsiloxane having a weight average molecular weight of 400,000 to 450,000 and polymethylvinylsiloxane having a weight average molecular weight of 200,000 to 400,000 at a weight ratio of 1: 1.5 to 3. It is advantageous to achieve the range of degrees and it is possible to produce sheets with excellent hardness.

In the present invention, the filler is used to control the viscosity of the composition and increase the mechanical strength of the final cured product. Such fillers may include fumed silica, wet silica, precipitated silica, titanium dioxide, talc, and the like. More preferably, fumed silica or wet silica having a specific surface area of 100 to 300 m 2 / g is used. The filler may be used without pretreatment, or pretreated with an organosilane compound such as hexamethyldisilazane, trimethylchlorosilane, dimethyldichlorosilane, cyclic dimethylsiloxane oligomer or hydroxyl terminated dimethylpolysiloxane. . The content of the filler is used in 10 to 40% by weight of the total solid composition content. When the amount is less than 10% by weight, the physical properties of the rubber (tensile, elongation, tear) are much lower, and when 40% by weight is used, the hardness and plasticity of the composition are high.

In the present invention, the silicone oil is used to facilitate the mixing of the solid polymethylvinylsiloxane and the filler and to be coated with silica. Any silicone process oil and organosilazane having an OH group at the terminal may be used without limitation. Specifically, for example, methyl hydroxide siloxane, vinyl methyl hydroxide siloxane, hexamethyldisilazane, 1,4-divinyl tetramethyldisilazane and the like can be used. The content is preferably used in 0.01 to 5% by weight of the total solid composition content. When the amount is less than 0.01% by weight, the effect is insignificant, and when it exceeds 5% by weight, the rubber properties are inferior and the surface becomes sticky, which is not preferable.

In the present invention, the crosslinking agent is used as a crosslinking agent of polymethylvinylsiloxane, and an organohydrogen polysiloxane containing two or more silicon-bonded hydrogen atoms in each molecule is preferable. Examples include methylhydrogenpolysiloxane, methylhydrogen polysiloxane, trimethylsiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymer, dimethylhydrogensiloxy-terminated dimethyl siloxane-methylhydrogensiloxane copolymer, dimethylsiloxane-methyl Hydrogensiloxane cyclic copolymers, and the like. The content is preferably used in 0.1 to 5% by weight of the total solid composition content. If the amount is less than 0.1% by weight, the effect is insignificant, and if it exceeds 5% by weight, the rubber properties are inferior and it is not preferable because it hinders curing when exaggerated.

In the present invention, the platinum-based catalyst is used to achieve the addition reaction of silicon, but the type is not limited. Specifically, particulate platinum, chloroplatinic acid, alcohol modified compounds of chloroplatinic acid, chloroplatinic acid and olefins Complexes, complexes of chloroplatinic acid and dialkyl tetramethyldisiloxane, and those supported on a carrier such as alumina, silica and carbon black can be used. Examples of such platinum-based catalysts include Pt_A from HRS, T25A from Momentive Performance Materials (MPM), C-25A from Shinnets, etc., which are dispersed in polyalkylalkenylsiloxane with a content of platinum (pt) of less than 1%. The content of the platinum-based catalyst is preferably used in the range of 0.1 to 5% by weight of the total solid composition content. If the amount is less than 0.1% by weight, the effect is insignificant, and if it is used more than 5% by weight, the curing rate is too fast, which is not preferable.

In the present invention, the release agent may further include 0.01 to 5% by weight of a release agent, it is preferable to use magnesium oxide (MgO) as the release agent is not limited to this, if the release agent commonly used in the art can be used without limitation.

The solid composition obtained by melting and kneading the solid composition described above is introduced into a melt extruder and melt-extruded to prepare a sheet. At this time, the extrusion die formed at the end of the extruder is used that is formed in a straight (private). According to the present invention, even when extruded using the die-shaped die, the solid composition is mixed and used in a specific plasticity range, and fine and non-uniform embosses are formed on the surface by vertically falling in the middle age direction. The shape of this emboss is shown in FIG. 3. 3 is a close-up image of the surface of the embossed silicone rubber sheet prepared according to the manufacturing method of the present invention using a camera, it was found that fine and non-uniform emboss was formed. The present invention is more preferable to serve as a sealing and cushioning cushion in the spacer panel and the like mounted on the outside of the display case because the friction resistance is formed compared to the sheet is not embossed by such embossing.

After passing through the die-shaped die, the first vertical passivator is passed in order to cure the sheet flowing down in the middle direction. At this time, the vertical vulcanizer is to cure the sheet conveyed in the vertical direction, the emboss is formed on the surface only to pass in the vertical direction, that is, gravity direction. At this time, the conditions are cured by adjusting the atmosphere inside the vertical vulcanizer is about 200 ~ 700 ℃, the speed of the sheet passing through the vertical vulcanizer is 1 ~ 20m / min. When the condition is satisfied, the emboss is formed, and thus a sheet having physical properties such as tensile, elongation, and tear may be manufactured.

It is also possible to wind the sheet cured through the vertical vulcanizer directly in the take-up roller to commercialize it.However, after passing through the first vertical vulcanizer, it passes through the horizontal vulcanizer for the second time, thereby improving physical properties such as hardness, tension and embossing. It can be stabilized more. The internal temperature of the horizontal current collector is preferably adjusted to an atmosphere of 70 ~ 200 ℃, the speed of the sheet passing through the horizontal current collector is to be 1 ~ 20m / min.

The present invention is 55 to 85% by weight of organopolysiloxane having a weight average molecular weight of 200,000 to 450,000, 10 to 40% by weight of filler, 0.01 to 5% by weight of silicone oil, 0.1 to 5% by weight of crosslinking agent, 0.1 to 5% by weight of platinum catalyst It is possible to provide an embossed silicone rubber sheet having an emboss formed on the surface by melting and extruding the solid composition having a degree of plasticity including 180 to 200 to flow in the gravity direction. The adhesive tape may be adhered to one surface of the embossed silicone rubber sheet according to the present invention to facilitate adhesion to another substrate surface. That is, the double-sided adhesive tape is used as the adhesive tape, and one side has adhesiveness with the silicone resin, and the other side has a double-sided adhesive tape having excellent adhesiveness with other substrates.

The embossed silicone rubber sheet according to the present invention is a low hardness sheet that exhibits adhesiveness enough to be used for sealing display materials, a dry surface, excellent restoring force, matteness, and random embossing, so that chlorine gas does not come out during combustion. Has characteristics.

When manufacturing using a solid composition of the range satisfying the plasticity according to the present invention it is possible to produce a silicone rubber sheet having a fine and non-uniform emboss is formed on the surface using a die-shaped die.

In addition, the embossed silicone rubber sheet according to the present invention has excellent adhesion, when used for sealing display materials, has a dry surface, excellent resilience, low gloss, random embossing, low hardness sheets, and chlorine gas during combustion. Has the property of not coming out.

Hereinafter, the present invention will be described by way of example for specific description of the present invention, but the present invention is not limited to the following examples.

Hereinafter, the physical property measuring method used in the embodiment of the present invention is as follows.

1) Plasticity: For measuring the viscosity of a solid polymer, the Williams plasticity number measured by the American Society for Testing and Materials (ASTM) Test Method 926 was measured. The invention is defined as the value measured at thickness x 100 of a cylindrical test specimen having a capacity of 2 cm 3 and a height of about 10 mm after application to a compressive load of 49 N at 25 ° C. for 3 minutes.

2) Hardness was measured using a Hardness tester by the ASTM D 2240 measuring method. The unit is degrees.

3) Tensile was measured using an Instron apparatus by ASTM D 412 measuring method. The unit is kgf / cm ² .

4) Elongation was measured using an Instron device by the ASTM D 412 measurement method. The unit is%.

5) Tear was measured using an Instron device by ASTM D 624 (B) measurement method. The unit is kgf / cm.

6) Chlorine gas emissions were measured using ICP-MS (Inductively Coupled Plasma Atomic Emission Spectroscopy) by inductive plasma analysis measurement method. The unit is ppm.

Example 1

Polymethylvinylsiloxane (30% by weight of HRN (H) of HRS having a molecular weight of 410,000 to 450,000g / mol, 30% by weight of molecular weight of 260,000 to 350,000g / mol and HRN (S) of HRS) in a blender 75% by weight, 20% by weight of wet silica (Z-142 from Rhodia with specific surface area of 200 m2 / g), methyl hydroxide siloxane oil (JY-113-3 by QIDONG XIN JIAYUAN CHEMICAL) 1.5 By weight, 0.5 wt% platinum-based catalyst (Pt_A HRS Co., Ltd.), 3 wt% crosslinking agent (CL_A HRS Co.) was added to melt-kneaded at 90 ~ 170 ℃ to prepare a uniformly mixed solid silicone composition. The plasticity of the composition was measured and found to be 180.

The solid silicone composition thus prepared was put into a hopper of a melt extruder (Twin Extruder, 75 mm, L / D 48), melted at 25 ° C., extruded through a die-shaped die, and then produced into a sheet. To fall in the direction of gravity was to form a fine embossed surface.

At the bottom of the sheet falling down was cured by passing through a vertical vulcanizer (length of the vertical vulcanizer 1m), wherein the temperature inside the vertical vulcanizer was 300 ℃, the speed of the sheet falling vertically was 3m / min.

The sheet cured through the vertical vulcanizer was wound around the take-up roller and stored.

The results of measuring the physical properties of the thus prepared sheet are shown in Table 1 below.

Example 2

Manufactured in the same manner as in Example 1, the sheet passed through the vertical vulcanizer was passed again through a horizontal vulcanizer (length of the evaluator 3 m, temperature 150 ℃, speed is 3 m / min) to stabilize the physical properties and then take up roller Winded up and stored. The results of measuring the physical properties of the thus prepared sheet are shown in Table 1 below.

Example 3

Polymethylvinylsiloxane (30% by weight of HRN (H) manufactured by HRS having a molecular weight of 410,000 to 450,000 g / mol, and 45% of HRN (S) by HRS made of 260,000 to 350,000g / mol) by a blender 75% by weight, 20% by weight of dry silica (M-5 having a specific surface area of 200 m 2 / g), and 1.4% by weight of methyl hydroxide siloxane oil (JY-113-3 from QIDONG XIN JIAYUAN CHEMICAL) , 0.5 wt% of a platinum-based catalyst (Pt_A from HRS) and 3 wt% of a crosslinking agent (CL_A from HRS) were added, and then 0.1 wt% of a release agent (magnesium oxide) was further added, and the type of silica was changed to the same method as in Example 1. It was prepared by. The plasticity of the composition was measured and found to be 190. The results of measuring the physical properties of the thus prepared sheet are shown in Table 1 below.

Example 4

Polymethylvinylsiloxane (30 weight% of HRN (H) of HRS with a molecular weight of 410,000 to 450,000 g / mol, and 50 weight of HRN (S) of HRS with a molecular weight of 260,000 to 350,000 g / mol) in a blender (Banvari mixer) 80% by weight, 15% by weight of dry silica (M-5 having a specific surface area of 200 m 2 / g), 1.4% by weight of methyl hydroxide siloxane oil (JY-113-3 from QIDONG XIN JIAYUAN CHEMICAL) , 0.5 wt% of a platinum-based catalyst (Pt_A from HRS) and 3 wt% of a crosslinking agent (CL_A from HRS) were added, and then 0.1 wt% of a release agent (magnesium oxide) was further added, and the type of silica was changed to the same method as in Example 1. It was prepared by. It was 150 as a result of measuring the plasticity of the said composition. The results of measuring the physical properties of the thus prepared sheet are shown in Table 1 below.

Example 5

Polymethylvinylsiloxane (32 weight% HRN (H) of HRS company having a molecular weight of 410,000 to 450,000 g / mol, and HRN (S) 38 weight of HRS company of 260,000 to 350,000 g / mol of a molecular weight in a blender (Banvari mixer) 70% by weight), 25% by weight of dry silica (M-5 with specific surface area of 200 m 2 / g), 1.4% by weight of methyl hydroxide siloxane oil (JY-113-3 from QIDONG XIN JIAYUAN CHEMICAL) , 0.5 wt% of a platinum-based catalyst (Pt_A from HRS) and 3 wt% of a crosslinking agent (CL_A from HRS) were added, and then 0.1 wt% of a release agent (magnesium oxide) was further added, and the type of silica was changed to the same method as in Example 1. It was prepared by. The plasticity of the composition was measured and found to be 250. The results of measuring the physical properties of the thus prepared sheet are shown in Table 1 below.

Comparative Example 1

40% by weight of polymethylvinylsiloxane (R-751 of Bluestar having a molecular weight of 260,000 to 360,000 g / mol) and 58% by weight of silica (C-5 having a specific surface area of 5 m 2 / g) in a blender 0.5 wt% platinum-based catalyst (Pt_A) and 1.5 wt% crosslinking agent (CL_A) were prepared in the same manner. The plasticity of the composition was measured and found to be 250.

Comparative Example 2

30 weight of polymethylvinylsiloxane (HRN (S) of HRS company having a molecular weight of 260,000-350,000 g / mol) and dry silica (M-5 with specific surface area of 200 m2 / g) in a blender %, 3% by weight of methyl hydroxide siloxane oil (JY-113-3 from QIDONG XIN JIAYUAN CHEMICAL), 1% 2,4-di-chloro Benzoyl Peroxide catalyst instead of platinum catalyst Prepared. It was 300 as a result of measuring the plasticity of the said composition.

TABLE 1

As shown in the above table, it can be seen that the tension and tear are further improved when the horizontal vulcanization is added after the vertical vulcanization.

In addition, as shown in the comparative example, it can be seen that the embossing is not formed when the plasticity range of the composition is outside the scope of the present invention.

In addition, the product using the platinum catalyst has good overall physical properties, and because it contains chlorine when using a general extruded peroxide catalyst, the chlorine removal process is required, but the product using the platinum catalyst has an advantage that such a process is unnecessary.

1 shows one aspect of the manufacturing process according to the present invention.

Figure 2 shows another embodiment of the manufacturing process according to the present invention.

3 is a photograph showing the surface embossing of the sheet according to the present invention.

Description of the main parts of the drawing-

10: Extruder 20: Vertical Curing Machine

30: horizontal current collector 40: winding roller

Claims (13)

a) kneading a solid silicone resin composition comprising an organopolysiloxane and a filler, a silicone oil, a crosslinking agent, and a platinum catalyst to prepare a solid composition having a plasticity of 150 to 250; b) extruding the solid composition in a sheet shape by melting in a melt extruder; c) naturally falling the extruded sheet in a vertical direction by gravity; d) curing the sheet falling naturally through a vertical current collector; e) winding the cured sheet; Method of manufacturing an embossed silicone rubber sheet comprising a. a) kneading a solid silicone resin composition comprising an organopolysiloxane and a filler, a silicone oil, a crosslinking agent, and a platinum catalyst to prepare a solid composition having a plasticity of 150 to 250; b) extruding the solid composition in a sheet shape by melting in a melt extruder; c) naturally falling the extruded sheet in a vertical direction by gravity; d) first curing the sheet falling naturally through a vertical current collector; e) passing the first cured sheet and passing it through a horizontal vulcanizer for secondary curing; f) winding the cured sheet; Method of manufacturing an embossed silicone rubber sheet comprising a. The method according to claim 1 or 2, The solid silicone resin composition has a weight average molecular weight of 200,000 to 450,000 organopolysiloxane 55 to 85% by weight, filler 10 to 40% by weight, silicone oil 0.01 to 5% by weight, crosslinking agent 0.1 to 5% by weight, platinum catalyst Method for producing an embossed silicone rubber sheet containing 0.1 to 5% by weight. The method of claim 3, wherein The solid silicone resin composition is a method for producing an embossed silicone rubber sheet containing 0.01 to 5% by weight of a release agent. The method of claim 3, wherein The organopolysiloxane is a polymethylvinylsiloxane having a weight average molecular weight of 400,000 to 450,000: polymethylvinylsiloxane having a weight average molecular weight of 200,000 to 400,000 in a 1: 1 to 1.5 to 3 weight ratio method for producing an embossed silicone rubber sheet. The method of claim 4, wherein The plasticity of the said solid silicone resin composition is 180-200, The manufacturing method of the embossed silicone rubber sheet. The method according to claim 1 or 2, Method of manufacturing an embossed silicone rubber sheet to adjust the internal temperature of the vertical current collector to 200 ~ 700 ℃ atmosphere. The method of claim 2, Method of manufacturing the embossed silicone rubber sheet to adjust the internal temperature of the horizontal current collector to 70 ~ 200 ℃ atmosphere. The method according to claim 1 or 2, The speed of the sheet passing through the vertical or horizontal vulcanizer is a method of producing an embossed silicone rubber sheet 1 ~ 20m / min. 55 to 85 wt% of organopolysiloxane having a weight average molecular weight of 200,000 to 450,000, 10 to 40 wt% of filler, 0.01 to 5 wt% of silicone oil, 0.1 to 5 wt% of crosslinking agent, and 0.1 to 5 wt% of platinum catalyst An embossed silicone rubber sheet having embossed on its surface by melt extrusion of a solid silicone resin composition having a plasticity of 150 to 250 and vulcanization while naturally falling in the gravity direction. The method of claim 10, An embossed silicone rubber sheet having a plasticity of the solid silicone resin composition is 180 to 200. The method according to claim 10 or 11, wherein An embossed silicone rubber sheet having an adhesive tape adhered to one surface of the embossed silicone rubber sheet to improve adhesion to other substrate surfaces. The method of claim 12, The embossed silicone rubber sheet is an embossed silicone rubber sheet used for sealing display materials.

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