JP4866691B2 - Release agent for oil-in-water silicone emulsion molds - Google Patents

Description

The present invention relates to a mold for the release agent, especially the preferred relative Da Ikast die, to oil-in-water silicone emulsion Mold release agent using branched organomodified silicones.

  Silicone oil is a component that imparts heat resistance to a mold release agent for die casting molds. Among them, alkyl-modified silicones such as alkyl-modified silicones, alkylaralkyl co-modified silicones and alkyl ester co-modified silicones are frequently used in actual work. ing. In these organically modified silicones, the side chain group alkyl group, aralkyl group and ester group not only have lubricity, but also gel on heating on the mold to form a strong release film. Excellent releasability can be obtained.

However, the adhesion under high temperature conditions was not sufficient, and further improvement was necessary. From this point of view, it has been proposed to obtain a release agent with excellent adhesion by using silicone having a hydrolyzable group in the side chain (Patent Document 1). However, in this case, since it has a hydrolyzable group, the stability when used as an aqueous release agent may be inferior.
Japanese Patent Laid-Open No. 9-12886

  Alkyl-modified silicones, aralkylalkyl co-modified silicones, and alkyl ester co-modified silicones are excellent in heat resistance and paintability, but have a disadvantage of poor adhesion because the viscosity is at most about 1,000 Pa · s. there were. These silicones can be produced by subjecting a trimethylsiloxy group-terminated methylhydrosiloxane to an addition reaction with a long chain α-monoolefin or α-methylstyrene in the presence of a hydrosilylation catalyst. In order to increase the viscosity, it is necessary to use a trimethylsiloxy group-terminated methylhydrosiloxane having a high degree of polymerization as a raw material. However, since there is a problem of gelation when the degree of polymerization is high, the degree of polymerization is usually 50 Can only be used to a certain extent.

Accordingly purpose of the present invention has excellent high-temperature adhesion and paintable property, suitable relative die casting mold, to provide an oil-in-water silicone emulsion Mold release agent.

That is, the present invention is an oil-in-water type silicone emulsion mold release agent characterized by containing at least the following (A) to (C).
(A) 100 mass parts of branched organic modified silicone oil having a viscosity at 25 ° C. of 2,000 mPa · s to 100,000 mPa · s and represented by the following average composition formula (1):
Average composition formula (1)
However, R ¹ in the average composition formula (1) is an independent short-chain alkyl group having 1 to 3 carbon atoms, R ² is an independent linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, R ³ is an independent aralkyl group having 7 to 12 carbon atoms, X is a chain or branched divalent hydrocarbon group having 6 to 18 carbon atoms or a divalent cyclic hydrocarbon group having 6 to 18 carbon atoms, Or it is alkylene siloxane of both terminals, a, b, c, and d are each 1 to 100, are integers satisfying 10 ≦ a + b + c + d ≦ 400, and 0.01 ≦ e ≦ 1.
(B) 0.1-50 mass parts of surfactant.
(C) 10 to 2000 parts by mass of water.

The release agent for oil- in- water silicone emulsion molds of the present invention can be produced while maintaining the current cost by using easily available raw materials, and is excellent in high-temperature adhesion and paintability, and is die-cast. It is suitable as a mold release agent.

The branched organically modified silicone oil of the present invention is represented by the following average composition formula (1).

R ¹ is an independent short-chain alkyl group having 1 to 3 carbon atoms, and examples thereof include a methyl group, an ethyl group, and a propyl group. From the viewpoint of industrial availability, a methyl group is preferred.

R ² is an independent chain, branched or cyclic alkyl group having 1 to 18 carbon atoms, such as methyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, decyl group, dodecyl group, tetradecyl group, etc. In particular, a chain, branched or cyclic alkyl group having 6 to 18 carbon atoms is preferable.
R ³ is an independent aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenylethyl group, a phenylpropyl group, and a 2-phenylpropyl group. From an industrial viewpoint, a 2-phenylpropyl group is preferable.

In the branched organic modified silicone oil according to the present invention , from the viewpoint of paintability, 50% or more of all R ² present in one molecule is a chain, branched or cyclic alkyl group having 6 to 18 carbon atoms. Preferably there is.

A, b, c, and d in the average composition formula (1) are each an integer of 1 to 100, and 10 ≦ a + b + c + d ≦ 400.

  X in the formula (1) is a chain or branched divalent hydrocarbon group having 6 to 18 carbon atoms or a divalent cyclic hydrocarbon group having 6 to 18 carbon atoms, or alkylene siloxane at both terminals. , E is 0.01 ≦ e ≦ 1. When e is smaller than 0.01, the degree of branching is small and the viscosity becomes low, which is not preferable. On the other hand, when it is larger than 1, it tends to gel during production, which is not preferable.

Examples of the chain or branched divalent chain hydrocarbon group having 6 to 18 carbon atoms include a hexylene group and an octylene group. The bivalent cyclic hydrocarbon group having 6 to 18 carbon atoms may be monocyclic or polycyclic, and examples thereof include the following polycyclic hydrocarbon groups.

As the both ends alkylene _{siloxane, -C 2 H 4 - (Me} 2 SiO-) m -C 2 H 4 - represented by those in the like. From the viewpoint of easy industrial availability, m is 2 or more, and preferably 100 or less. If it exceeds 100, the reactivity of the corresponding alkenylsiloxane at both terminals becomes low, and the silicone oil may not easily have a branched structure.

In the branched organically modified silicone of the present invention, the content of the organically modified group is preferably 25 to 50 mol%, particularly 30 to 50 mol%, based on the total organic groups bonded to the silicon atom. If the content of the organic modifying group is too small, the paintability may be inferior, and if it is too high, the cost may increase.
In the present invention, the “organic modifying group” is a chain, branched or cyclic hydrocarbon group having 6 to 18 carbon atoms, and specifically includes a hexyl group, an octyl group, a decyl group, a dodecyl group, and the like. Can be mentioned.

  The branched organically modified silicone oil of the present invention can be produced according to a known method as described below. That is, after a monoolefin is added to a chain silicone having 5 or more SiHs in the presence of a hydrosilylation catalyst, a diolefin is added to form a branched structure, and a monoolefin is added to the remaining SiH. By doing so, the branched organically modified silicone oil of the present invention is obtained.

  Examples of the monoolefin include 1-hexene, 1-octene, 1-decene, 1-dodecene, and 1-octadecene. You may use these in mixture of 2 or more types. Examples of the diolefin include 1,5-hexadiene, 1,5-octadiene, and 5-vinyl-2-norbornene. The order in which the monoolefin is added is not particularly limited, and may be reacted separately or simultaneously using a mixture.

  The branched organically modified silicone oil of the present invention has a branched structure with high viscosity in which not only the alkyl group and aralkyl group have lubricity, but also gels when heated on a mold to form a strong release film. Since it is oil, it can be set as the mold release agent excellent in adhesiveness.

  The release agent of the present invention is a branched organic modification of the present invention having a viscosity at 25 ° C. of 2,000 to 100,000 mPa · s using a single cylindrical rotational viscometer according to JIS K7117-1. Contains silicone oil. When the viscosity is less than 2,000 mPa · s, the adhesion to the mold tends to be inferior, and when the viscosity is more than 100,000 mPa · s, it tends to cause stickiness and nozzle clogging.

The release agent for oil-in-water silicone emulsion molds of the present invention contains at least (A) the branched organically modified silicone oil of the present invention, (B) a surfactant, and (C) water.
The surfactant as the component (B) is a surfactant typified by polyoxyethylene linear alkyl ether and / or polyoxyethylene branched alkyl ether.

  As polyoxyethylene linear alkyl ether and / or polyoxyethylene branched alkyl ether, for example, polyoxyethylene (5) isononyl ether (RAA-03001, trade name of Nippon Emulsifier Co., Ltd .; HLB12.2) , Polyoxyethylene (3) decyl ether (Fine Surf D1303, trade name manufactured by Aoki Yushi Kogyo Co., Ltd .; HLB9.0), polyoxyethylene (5) decyl ether (Fine Surf D1305, product manufactured by Aoki Oil & Fat Co., Ltd.) Name: HLB 11.9), polyoxyethylene (10) decyl ether (Finesurf D1310, trade name manufactured by Aoki Yushi Kogyo Co., Ltd .; HLB 14.7), polyoxyethylene (8) isoundecyl ether (Emulgen 1108, Kao) Trade name of HLB13. 5) and the like.

  In the release agent for oil-in-water silicone emulsion molds of the present invention, these surfactants may be used alone or in admixture of two or more. For example, a surfactant having a polyethylene oxide addition mole number of 2 to 10 moles and a surfactant having a polyethylene oxide addition mole number of 10 to 20 moles are mixed to adjust the average HLB to 10 to 15 Can be used.

In this invention, although the compounding quantity of (B) component shall be 0.1-50 mass parts with respect to 100 mass parts of (A) component, it is more preferable that it is 1-20 mass parts. If the blending amount is less than 0.1 parts by mass, the stability of the emulsion and the stability of dilution in water are reduced. Moreover, when it exceeds 50 mass parts, a use may be limited.

The water of component (C) is a dispersion medium, and pure water, ion exchange water, tap water, or the like can be used. In this invention, although the compounding quantity of (C) component shall be 10-2,000 mass parts with respect to 100 mass parts of (A) component, it is more preferable that it is 50-1,000 mass parts. If the blending amount is less than 10 parts by mass, the stability of the emulsion and the dispersion stability to other components may decrease, and if the blending amount exceeds 2,000 parts by mass, the long-term storage stability decreases. There is a case.

  In the oil-in-water type silicone emulsion mold release agent of the present invention, in addition to the components (A) to (C), various additives may be added as long as the properties of the release agent are not impaired. Can do. Examples of such additives include anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants other than the component (B), aqueous polymers, rust inhibitors, and fungicides. , Preservatives, pH adjusters and the like.

  The method for producing the release agent for the oil-in-water silicone emulsion mold of the present invention is not particularly limited, but after mixing the components (A) to (C) and other additives as necessary, A method of stirring at high speed using a mixer or the like and emulsifying is suitably used. In the present invention, the average particle size of the emulsion is usually 0.15 μm or more, and preferably 0.15 to 0.5 μm.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

A hydrosilylated platinum catalyst (platinum amount 0.05 parts by mass) was added to 1,902 parts by mass of trimethylsiloxymethyl hydrogen siloxane at both ends and Me ₃ SiO (HMeSiO) _n SiMe ₃ (n = 48). Then, was added dropwise over α- methylstyrene 700 parts by mass of 1 _hour, 50 moles of _{H 2 C = CH (CH 2} ) 9 CH 3 and _{H 2 C = CH (CH 2} ) 11 CH 3: 50 moles of 2,100 parts by mass of the monoolefin mixture was added dropwise over 2 hours, and 26 parts by mass of 1,5-hexadiene was added dropwise over 6 minutes. Next, 2,259 parts by mass of a 50 mol: 50 mol monoolefin mixture of H ₂ C═CH (CH ₂ ) ₉ CH ₃ and H ₂ C═CH (CH ₂ ) ₁₁ CH ₃ was added dropwise over 1 hour. During this time, the temperature in the reaction system (internal temperature) was maintained at 75 ° C.

Next, the reaction system was heated until the internal temperature reached 110 ° C., and further heated for 1 hour to maintain 110 ° C. to complete the addition reaction, whereby 6,968 parts by mass of branched organically modified siloxane was obtained. . The completion of the addition reaction was confirmed by confirming that the absorption spectrum due to SiH groups in the trimethylsiloxymethylhydrogensiloxane at both ends of the raw material disappeared by FT-IR analysis.
The obtained branched organic modified siloxane was used as silicone oil (1). The viscosity of the silicone oil (1) at 25 ° C. was 3,400 mPa · s.

(Preparation of aqueous release agent)
30 parts by mass of silicone oil (1), 3 parts by mass of a mixture of 10 moles of adduct of ethylene oxide of a straight chain higher alcohol having 10 carbon atoms and 3 moles of adduct so that HLB is 12, and 30 parts by weight of water The mixture was stirred and emulsified using a homomixer to prepare a premixed solution, and water was added to the premixed solution to obtain a total of 100 parts by mass of an aqueous release agent (1).

  The same procedure as in Example 1 was performed except that 38 parts by mass of 5-vinyl-2-norbornene was used instead of 1,5-hexadiene used in Example 1, and 6,900 parts by mass of branched organically modified siloxane was added. This was synthesized and used as silicone oil (2). The viscosity of the silicone oil (2) at 25 ° C. was 2,560 mPa · s. Silicone oil (2) was emulsified in the same manner as in Example 1 to obtain an aqueous release agent (2).

  In place of 1,5-hexadiene used in Example 1, except that 52 parts by mass of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane was used, 7,010 parts by mass of branched organically modified siloxane was produced and used as silicone oil (3). The viscosity of the silicone oil (3) at 25 ° C. was 4,060 mPa · s. Silicone oil (3) was emulsified in the same manner as in Example 1 to obtain an aqueous release agent (3).

[Comparative Example 1]
Without using 1,5-hexadiene was used in Example 1, instead of 50 moles of _{H 2 C = CH (CH 2} ) 9 CH 3 and _{H 2 C = CH (CH 2} ) 11 CH 3: 50 moles of Except having used 2,100 mass parts of monoolefin mixtures, it carried out like Example 1 and obtained the chain organic modified siloxane 7,020 mass parts which does not have a branched structure. The viscosity at 25 ° C. of this product was 860 mPa · s. The obtained compound was emulsified in the same manner as in Example 1 to obtain an aqueous release agent (4).

Table 1 shows the physical properties of the silicone oils (1) to (4) obtained in Examples 1 to 3 and Comparative Example 1.
The viscosity was measured according to JIS K7117-1.

  10 ml of water-based mold release agents (1) to (4) prepared in each Example and Comparative Example diluted 20 times with water were spray-coated on a steel plate heated to 250 ° C. under the same conditions from a distance of 10 cm. The following performance tests were conducted. The results are shown in Table 2.

1. Diffusivity The diffusivity was compared from the extent of spreading in the state where the water-based release agent was applied (horizontal direction × vertical dimension).
2. Uniformity The surface state of the cured film of the aqueous release agent obtained by treatment at 250 ° C./10 minutes was observed.
3. Paintability The water-based release agent film obtained by treatment at 250 ° C. for 10 minutes was compared with the repellent property of the oil-based ink, and evaluated as follows.
○: No ink repellency
Δ: Ink repelling in some areas
X: Ink repelling occurs throughout. Adhesiveness: The amount of the water-based release agent adhering to the steel sheet was measured and compared.

  As is clear from Table 2, the branched organic modified silicone oil of the present invention has a higher viscosity than the chain organic modified silicone oil of the comparative example, and the water of the present invention using the silicone oil of the present invention. It has been demonstrated that the release agent for oil-type silicone emulsion molds is excellent not only in diffusibility and adhesion but also in paintability.

  The branched organically modified silicone oil of the present invention is not only excellent in high temperature adhesion and paintability, but also can be produced at low cost, and is useful as a mold release agent in die casting using a mold.

Claims (5)

A release agent for oil-in-water silicone emulsion molds containing at least the following (A) to (C);
(A) 100 mass parts of branched organic modified silicone oil having a viscosity at 25 ° C. of 2,000 mPa · s to 100,000 mPa · s and represented by the following average composition formula (1):
However, R ¹ in the average composition formula (1) is an independent short-chain alkyl group having 1 to 3 carbon atoms, R ² is an independent linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, R ³ is an independent aralkyl group having 7 to 12 carbon atoms, X is a chain or branched divalent hydrocarbon group having 6 to 18 carbon atoms or a divalent cyclic hydrocarbon group having 6 to 18 carbon atoms, Or a both-end alkylene siloxane, a, b, c and d are each 1 to 100, an integer satisfying 10 ≦ a + b + c + d ≦ 400, and 0.01 ≦ e ≦ 1;
(B) 0.1-50 parts by mass of a surfactant;
(C) 10 to 2000 parts by mass of water. In the average composition formula (1) in 50% or more of branched organic modified silicone oil that exists in one molecule all R ² represented is a chain, branched or cyclic alkyl group having 6 to 18 carbon atoms The release agent for oil-in-water type silicone emulsion molds according to claim 1. Wherein both ends alkylene siloxane represented by X is _{-C 2 H 4 - (Me 2} SiO-) m -C 2 H 4 - is represented by a m = 2 to 100, set forth in claim 1 or 2 Release agent for oil-in-water silicone emulsion molds . 25 to 50 mol% of all organic groups present in one molecule of the branched organically modified silicone oil represented by the average composition formula (1) is a chain, branched or cyclic hydrocarbon having 6 to 18 carbon atoms. The mold release agent for oil-in-water type silicone emulsion molds in any one of Claims 1-3 which is group . The oil-in-water type silicone emulsion mold release according to any one of claims 1 to 4, wherein the component (B) is a polyoxyethylene linear alkyl ether and / or a polyoxyethylene branched alkyl ether. Agent .