JP2014136381A - Release agent for rubber or resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release agent for a rubber or resin molding which maintains releasability from a mold for the long term, and a mold surface treatment method for a rubber or resin molding using the agent, and a mold for a rubber or resin molding.SOLUTION: This invention relates to a release agent for a rubber or resin molding including a fluorine-containing silane compound having hydrolyzability.

Description

The present invention relates to a release agent for rubber or resin molding, a rubber or resin molding die surface treatment method using the same, and a rubber or resin molding die.

In general, a mold release agent is applied to the surface of a mold for molding such as rubber or resin to prevent the product from being difficult to peel off from the mold after molding. For example, a mold release agent containing silicone oil, etc. Is used (see Patent Document 1).

However, when a conventional mold release agent is used, as the number of times of molding increases, the release agent on the surface decreases, so that the release action is lowered and there is a problem in its durability (durability). .

JP-A-8-99322

The present invention solves the above-mentioned problems and provides a mold release agent for rubber or resin molding that can be released from the mold for a long time, a rubber or resin mold surface treatment method using the same, and rubber or resin. An object is to provide a mold for molding.

The present invention relates to a rubber or resin molding release agent containing a hydrolyzable fluorine-containing silane compound. Here, the hydrolyzable fluorine-containing silane compound preferably has a perfluoroether structure.

The present invention relates to a rubber or resin mold surface treatment method in which the rubber or resin molding mold release agent is treated on a mold surface, hydrolysis occurs on the mold surface, and a chemical bond is generated.

The present invention also relates to a rubber or resin molding die whose surface is treated with the rubber or resin molding release agent.

According to the present invention, since it is a rubber or resin molding release agent containing a hydrolyzable fluorine-containing silane compound, the release property from the mold can be maintained for a long time.

The release agent for molding rubber or resin of the present invention contains a hydrolyzable fluorine-containing silane compound. The conventional mold release agent does not form a chemical bond with the mold surface, and the mold release agent can be removed by repeated molding, so there is a problem in durability (long-term durability of the mold release action). On the other hand, when the release agent containing the hydrolyzable fluorine-containing silane compound is treated on the surface of the molding die, hydrolysis occurs on the surface of the die, and a chemical bond is formed with the surface. Therefore, since the mold release agent is fixed to the mold surface, the reduction of the mold release agent during rubber or resin molding (rubber vulcanization, thermoplastic elastomer injection, etc.) is suppressed, and the mold surface is removed. It is possible to maintain a releasing action for preventing the adhesion of rubber and resin for a long time.

Examples of the hydrolyzable fluorine-containing silane compound in the present invention include fluorine-containing silane compounds having a hydrolyzable group. The fluorine-containing silane compound is preferably a silane compound having a perfluoroether structure, and specific examples include a silane compound having a hydrolyzable group and a perfluoropolyether group (in one molecule). Here, as a hydrolyzable group, the below-mentioned hydrolyzable group represented by a methoxy group, an ethoxy group, etc., and as a perfluoroether group, a divalent having a below-mentioned linear perfluoropolyalkylene ether structure. And the like. The fluorine-containing silane compound preferably has a fluoroalkyl group such as a perfluoroalkyl group.

As said fluorine-containing silane compound, the silane compound represented by following formula (1), (2) can be used conveniently.

（式（１）中、Ｒｆ^１は、パーフルオロアルキル基を表す。Ｚは、フッ素又はトリフルオロメチル基を表す。ａ、ｂ、ｃ、ｄ、ｅは、同一若しくは異なって０又は１以上の整数を表し、ａ＋ｂ＋ｃ＋ｄ＋ｅは、１以上であり、ａ、ｂ、ｃ、ｄ、ｅで括られた各繰り返し単位の存在順序は、式中で限定されない。Ｙは、水素又は炭素数１〜４のアルキル基を表す。Ｘ^１は、水素、臭素又はヨウ素を表す。Ｒ^１は、水酸基又は加水分解可能な置換基を表す。Ｒ^２は、水素又は１価の炭化水素基を表す。ｌは、０、１又は２を表す。ｍは１、２又は３を表す。ｎは、１以上の整数を表す。）

(In formula (1), Rf ¹ represents a perfluoroalkyl group. Z represents fluorine or a trifluoromethyl group. A, b, c, d, and e are the same or different and are 0 or 1 or more. Represents an integer, a + b + c + d + e is 1 or more, and the existence order of each repeating unit enclosed by a, b, c, d, e is not limited in the formula, Y is hydrogen or having 1 to 4 carbon atoms Represents an alkyl group, X ¹ represents hydrogen, bromine or iodine, R ¹ represents a hydroxyl group or a hydrolyzable substituent, R ² represents hydrogen or a monovalent hydrocarbon group, and l represents 0 represents 0, 1 or 2. m represents 1, 2 or 3. n represents an integer of 1 or more.)

（式（２）中、Ｒｆ^２は、−（Ｃ_ｋＦ_２ｋ）Ｏ−（ｋは１〜６の整数）で表される単位を含み、分岐を有しない直鎖状のパーフルオロポリアルキレンエーテル構造を有する２価の基を表す。Ｒ^３は、同一若しくは異なって炭素原子数１〜８の１価炭化水素基を表す。Ｘ^２は、同一若しくは異なって加水分解性基又はハロゲン原子を表す。ｓは、同一若しくは異なって０〜２の整数を表す。ｔは、同一若しくは異なって１〜５の整数を表す。ｈ、ｉは、同一若しくは異なって２又は３を表す。

(In the formula (2), Rf ² is a linear perfluoropolyalkylene ether containing a unit represented by — (C _k F _2k ) O— (k is an integer of 1 to 6) and having no branch. R ³ represents the same or different monovalent hydrocarbon group having 1 to 8 carbon atoms, and X ² represents the same or different hydrolyzable group or halogen atom. S is the same or different and represents an integer of 0 to 2. t is the same or different and represents an integer of 1 to 5. h and i are the same or different and represent 2 or 3.

Here, Rf ¹ in the formula (1) is not particularly limited as long as it is a perfluoroalkyl group constituting a general organic-containing fluoropolymer, and for example, a linear or branched group having 1 to 16 carbon atoms. Things. Of these, CF _3- , C ₂ F _5- , and C ₃ F ₇ -are preferable.

A, b, c, d and e in the formula (1) represent the number of repeating units of the perfluoropolyether chain constituting the main skeleton of the fluorine-containing silane compound, and each independently preferably 0 to 200; ~ 50 is more preferred. Further, a + b + c + d + e (total of a to e) is preferably 1 to 100. The order of existence of each repeating unit enclosed by a, b, c, d, and e is described in this order in formula (1), but the order of binding of these repeating units is in this order. The order is not limited and any order may be used.

Examples of the alkyl group having 1 to 4 carbon atoms represented by Y in the formula (1) include a methyl group, an ethyl group, a propyl group, and a butyl group, and may be linear or branched. When X ¹ is bromine or iodine, the fluorine-containing silane compound is likely to generate a chemical bond.

The hydrolyzable substituent represented by R ¹ in the formula (1) is not particularly limited, but halogen, —OR ¹¹ , —OCOR ¹¹ , —OC (R ¹¹ ) ═C (R ¹² ) ₂ , —ON═C _{^{(R 11) 2, -ON =}} CR 13 , and the like are preferable. Here, R ¹¹ is an aliphatic hydrocarbon group or an aromatic hydrocarbon group, R ¹² is hydrogen or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and R ¹³ is a divalent aliphatic carbon group having 3 to 6 carbon atoms. Represents a hydrogen group. More preferably, _chlorine, -OCH 3, is _-OC 2 _{H 5.} The monovalent hydrocarbon group represented by R ² is not particularly limited, but is preferably a methyl group, an ethyl group, a propyl group, a butyl group or the like, and may be linear or branched.

In the formula (1), l represents the number of carbon atoms of an alkylene group present between carbon constituting the perfluoropolyether chain and silicon bonded thereto, and is preferably 0. m represents the number of bonds of the substituent R ¹ bonded to silicon, and R ² is bonded to the portion of the silicon to which R ¹ is not bonded. Although the upper limit of n is not specifically limited, Preferably it is an integer of 1-10.

On the other hand, the group represented by Rf ² in the formula (2) is not particularly limited, but when s is 0 each, the end of the Rf ² group bonded to the oxygen atom in the formula (2) may not be an oxygen atom. preferable. As the k in Rf ^2, 1 to 4 integer are preferred. As the group represented by Rf ² , specifically, —CF ₂ CF ₂ O (CF ₂ CF ₂ CF ₂ O) _j CF ₂ CF ₂ — (wherein j is 1 or more, preferably 1 to 50 , More preferably an integer of 10 to 40), —CF ₂ (OC ₂ F ₄ ) _p — (OCF ₂ ) _q — (wherein p and q are each 1 or more, preferably 1 to 50, More preferably, it is an integer of 10 to 40, and the sum of p + q is an integer of 10 to 100, preferably 20 to 90, more preferably 40 to 80, and (OC ₂ F ₄ ) of the repeating unit in the formula and (OCF ₂ ) is random).

R ^{3 in the} formula (2) is preferably a monovalent hydrocarbon group of 1 to 3, such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, etc. Alkyl group; cycloalkyl group such as cyclopentyl group and cyclohexyl group; aryl group such as phenyl group, tolyl group and xylyl group; aralkyl group such as benzyl group and phenethyl group; vinyl group, aryl group, butenyl group, pentenyl group, hexenyl And an alkenyl group such as a group. Of these, a methyl group is preferable.

Examples of the hydrolyzable group represented by X ² in the formula (2) include alkoxy groups such as methoxy group, ethoxy group, propoxy group and butoxy group; alkoxyalkoxy groups such as methoxymethoxy group, methoxyethoxy group and ethoxyethoxy group; Alkenyloxy groups such as allyloxy group and isopropenoxy; acyloxy groups such as acetoxy group, propionyloxy group, butylcarbonyloxy group and benzoyloxy group; dimethyl ketoxime group, methyl ethyl ketoxime group, diethyl ketoxime group, cyclopentoxime group, Ketoxime groups such as cyclohexanoxime group; N-methylamino group, N-ethylamino group, N-propylamino group, N-butylamino group, N, N-dimethylamino group, N, N-diethylamino group, N- An amino group such as a cyclohexylamino group; N -Amido groups such as -methylacetamide group, N-ethylacetamide group, N-methylbenzamide group; and aminooxy groups such as N, N-dimethylaminooxy group and N, N-diethylaminooxy group. Further, examples of the halogen atom represented by X ^2, a chlorine atom, a bromine atom, and an iodine atom. Of these, a methoxy group, an ethoxy group, an isopropenoxy group, and a chlorine atom are preferable.

In formula (2), s is preferably 1, and t is preferably 3. h and i are preferably 3 from the viewpoint of hydrolyzability.

The average molecular weight of the fluorine-containing silane compound is preferably in the range of 1000 to 10,000 from the viewpoint of sustaining the mold release action. In addition, an average molecular weight can be measured by standard polystyrene conversion using a gel permeation chromatograph (GPC).

As a commercial item of the said fluorine-containing silane compound, OPTOOL DSX (made by Daikin Industries, Ltd.), KY-130 (made by Shin-Etsu Chemical Co., Ltd.), etc. are mentioned.

The mold release agent for rubber or resin molding of the present invention is used as a mold release agent on the mold surface when molding rubber or resin with a mold. Examples of the rubber and resin include vulcanized rubber, A thermoplastic elastomer etc. are mentioned. As the vulcanized rubber and thermoplastic elastomer, those having a carbon atom adjacent to the double bond (a carbon atom at the allylic position) are preferably used.

Examples of rubbers used for vulcanized rubber include diene rubbers such as styrene butadiene rubber, butadiene rubber, isoprene rubber, natural rubber, and deproteinized natural rubber, and butyl rubber and halogenated butyl rubber containing isoprene units as a degree of unsaturation. Is mentioned.

Vulcanization of vulcanized rubber includes sulfur vulcanization and peroxide vulcanization. In sulfur vulcanization, compounding agents such as commonly used vulcanization accelerators, zinc oxide, fillers, and silane coupling agents may be added. As the filler, carbon black, silica, clay, talc, calcium carbonate and the like can be suitably used.

The rubber vulcanization conditions may be appropriately set, and the lower limit of the rubber vulcanization temperature is preferably 140 ° C. or higher, more preferably 170 ° C. or higher, still more preferably 175 ° C. or higher, and the upper limit is 190 ° C. or lower. It is preferable that

As the thermoplastic elastomer, for example, a polymer compound having a rubber elasticity at normal temperature (thermoplastic elastomer (TPE) such as a styrene-butadiene styrene copolymer) by a collection of plastic components (hard segments) serving as a crosslinking point Etc .; a high molecular compound having rubber elasticity in which a thermoplastic component and a rubber component are mixed and dynamically crosslinked by a crosslinking agent (including a styrene block copolymer or an olefin resin and a crosslinked rubber component) And thermoplastic elastomers (TPV) such as polymer alloys).

Other suitable thermoplastic elastomers include nylon, polyester, urethane, polypropylene, and their dynamically crosslinked thermoplastic elastomers. In the case of a dynamically crosslinked thermoplastic elastomer, a material obtained by dynamically crosslinking a halogenated butyl rubber in a thermoplastic elastomer is preferable. In this case, the thermoplastic elastomer is preferably nylon, urethane, polypropylene, SIBS (styrene-isobutylene-styrene block copolymer) or the like.

The rubber or resin molding mold release agent described above can impart the durability of the mold release action by treating the rubber or resin molding mold surface, and the rubber or resin mold surface of the present invention. The treatment method is a method of treating such a rubber or resin molding mold release agent on the surface of a rubber or resin molding die. Among these, a rubber or resin mold surface treatment method in which the above-described rubber or resin molding release agent is treated on the mold surface, hydrolysis occurs on the mold surface, and a chemical bond is generated is preferable.

As a method of treating the mold release agent for rubber or resin molding, a method of bringing the mold release agent into contact with the surface of the mold for rubber or resin can be applied, for example, a coating method by coating, spraying, dipping or the like. . The treatment method is preferably a method of drying after coating with the release agent and causing hydrolysis by moisture in the air. Thereby, since a chemical bond is generated and fixed between the mold release agent and the mold surface, the mold release effect can be maintained for a long period of time. What is necessary is just to set drying temperature suitably, such as the temperature which a chemical bond produces | generates.

In addition, you may process the mold release agent for rubber | gum or resin molding directly on the surface of a metal mold | die, and you may implement in the produced process metal mold | die, or rubber | gum or resin on the surface of metal plates, such as a stainless steel plate Molding may be performed by treating the mold release agent and placing the resulting treated plate in a mold. In other words, the rubber or resin molding release agent may be applied directly to the mold or may be applied to a metal plate or the like used indirectly in the mold.

In the treatment, the concentration of the release agent for rubber or resin molding may be appropriately adjusted from the viewpoint of applicability and the like.

By using the rubber or resin molding release agent or the mold surface treatment method described above, a mold (mold surface) treated with the mold release agent can be obtained. Since such a mold is coated with the above-mentioned mold release agent, the mold release action has excellent durability and durability.

The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

Example 1
Natural rubber, silica, and a silane coupling agent were kneaded with a Banbury mixer, and then other compounding agents were kneaded with an open roll to prepare a compounded rubber.
After washing the surface of the SUS plate with methanol, a release agent (Optotool DSX manufactured by Daikin Industries, Ltd.) is applied to the surface, dried at room temperature for 1 day, and caused to hydrolyze by moisture in the air to react and fix. I let you. Place this surface-treated SUS plate on a PET film with a PET film laid on it, set the compounded rubber on it, place the PET film on it, and cover the mold with a top cover at 170 ° C. For 10 minutes.

In addition, the composition of the vulcanized rubber used (an example of a composition that easily adheres to the mold and is difficult to release) is as follows, and the materials are shown below.
(Combination)
Natural rubber 100 parts by mass, silica 60 parts by mass, silane coupling agent 6 parts by mass, stearic acid 2 parts by mass, zinc oxide 3 parts by mass, powdered sulfur 2 parts by mass, vulcanization accelerator CZ 1.5 parts by mass, vulcanization acceleration Agent D 0.5 parts by mass, zinc acrylate 10.0 parts by mass (material used)
NR: RSS # 3
Silica: ULTRASIL VN3 manufactured by Degussa
Silane coupling agent: Si266 manufactured by Degussa
Stearic acid: Stearic acid “椿” manufactured by NOF Corporation
Zinc oxide: Zinc Hua 1 powder sulfur manufactured by Mitsui Mining & Smelting Co., Ltd. Powder sulfur: Powder sulfur manufactured by Tsurumi Chemical Co., Ltd. (oil content 5%)
Vulcanization accelerator CZ: Noxeller CZ manufactured by Ouchi Shinsei Chemical Co., Ltd.
Vulcanization accelerator D: Soxinol D manufactured by Sumitomo Chemical Co., Ltd.
Zinc acrylate: Sunseller SR made by Sanshin Chemical Co., Ltd.

(Comparative Example 1)
The rubber was vulcanized in the same manner as in Example 1 except that the surface of the SUS plate was washed with methanol and no surface treatment was performed.

When each rubber was taken out from the mold after vulcanization, the SUS plate could be easily peeled off from the rubber in Example 1, whereas in Comparative Example 1, the rubber could not be peeled off from the SUS plate. It was.

Further, even when the surface-treated SUS plate produced in Example 1 was used and vulcanized 10 times with the same composition, the ease of peeling of the rubber after vulcanization did not change.

Claims (4)

A release agent for molding rubber or resin containing a hydrolyzable fluorine-containing silane compound. The rubber or resin mold release agent according to claim 1, wherein the hydrolyzable fluorine-containing silane compound has a perfluoroether structure. A rubber or resin mold surface treatment method in which the rubber or resin molding mold release agent according to claim 1 or 2 is treated on a mold surface, hydrolysis occurs on the mold surface, and a chemical bond is generated. A rubber or resin molding die having a surface treated with the rubber or resin molding release agent according to claim 1 or 2.