JPH044923B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a mold release agent. More specifically, the present invention relates to a mold release agent that has excellent mold release properties and solubility. general formula (Here, R _f is a C ₁ to _{C 20} polyfluoroalkyl group, and R' is a lower alkylene group.) Phosphonic acid or its acid salt and wax or oil with a melting point of 100°C or less are essential ingredients. A mold release agent containing the following was previously proposed by the present applicant (Japanese Patent Application Laid-open No. 180597/1983,
(Patent Application No. 57-177330 and No. 58-41891). Although such mold release agents sufficiently exhibit the desired effect in terms of mold release properties, they have the following problems because phosphonic acid or its acid salt has low solubility in solvents with low polarity. There is. (a) Because it must be used as a distributed system,
It tends to cause uneven coating when applied to molds, etc.(b) In order to prevent the deterioration of mold releasability due to these causes, the amount of coating at one time is inevitably large, resulting in high costs.(c) Precipitation occurs. The solution to these problems is to monoesterify the phosphonic acid represented by the above formula [] or its acid salt with a hydrocarbon group such as an alkyl group, an aryl group, or an aralkyl group. The present inventors have found that this can be effectively achieved by. Therefore, the present invention relates to a mold release agent, which has the general formula (wherein R _f and R' are as defined above, and R is a hydrocarbon group) or a salt thereof and the melting point
Contains wax or oil at a temperature of 100℃ or less. The phosphonic acid monoester or its salt represented by the above general formula [] is synthesized through the following steps. (X: halogen atom) Examples of R _f −R′−X used: C ₆ F ₁₃ C ₂ H ₄ I, C ₈ F ₁₇ C ₂ H ₄ I, C ₁₀ F ₂₁ C ₃ C ₆ I,
_C12F25CH2Cl , preferably _C8F17C2H4I Examples _{of P} ( _{OR ) 3} used: P( _OCH3 ) ₃ , P( _{OC2H5 ) 3} , _P ( _{OC3H 7} ) ₃ ,

[Formula], P(OC ₄ H ₉ ) ₃ , preferably

【formula】

(3) If desired, neutralize with an appropriate base to form a salt. Salt formations include, for example, sodium hydroxide, ammonium hydroxide, zinc sulfate, zinc acetate, zinc oxide,
Using triethylamine, triethanolamine, tris(2-hydroxyethyl)amine, etc.
Usually, titration is carried out with the above-mentioned salt-forming reactant while checking the equivalence point with pH to obtain an acidic mono- to trivalent metal salt, amine salt or ammonium salt. The phosphonic acid monoester (salt) synthesized in this way has a weight ratio of about 0.05 to
A mold release agent is prepared by blending wax or oil with a melting point of 100°C or less in a proportion of 10, preferably about 0.2 to 5. Examples of waxes or oils with a melting point of 100°C or lower include vegetable wax, animal wax, petroleum wax, silicone oil, fluorine oil, mineral oil, vegetable oil, animal oil, synthetic oil, and phosphate ester oil. Silicone oils, typified by siloxanes, are preferably used. The mold release agent is prepared by dissolving the phosphonic acid monoester or its salt and the wax or oil in an organic solvent. Examples of organic solvents include alcohols such as methanol, ethanol, n-propanol, and isopropanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, dioxane, and tetrahydrofuran; ethyl acetate;
Esters such as butyl acetate, polyhydric alcohol derivatives such as methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, carbon tetrachloride, methylene chloride, ethylene chloride,
At least one type of halogenated hydrocarbon such as trichlorethylene, perchlorethylene, trichloroethane, trichlorofluoromethane, tetrachlorodifluoroethane, trichlorotrifluoroethane, etc. is used, or these organic solvents are used in combination with water. There is also. The most preferred solvent system is a mixed solvent of isopropanol and trichlorotrifluoroethane (Freon 113). Even if the phosphonic acid monoester or its salt is dissolved in these organic solvent systems at a concentration of about 0.1% by weight or less, when it is applied to the object to be released from the mold, it will not be effective for mold release. Demonstrate performance. That is, since the mold release agent according to the present invention uses a phosphonic acid monoester or a salt thereof that exhibits extremely good solubility in organic solvents, even if the concentration of the phosphonic acid monoester or its salt is 0.1% by weight or less, the phosphonic acid or When the acid salt is used, it is possible to easily obtain excellent mold release properties that could not be easily achieved even with a mold release agent prepared at a concentration of 0.5% by weight. Furthermore, because of its good solubility, the mold release agent of the present invention easily forms a homogeneous system, so it does not form precipitates unlike conventional mold release agents, and has good storage stability. be. The mold release agent can be applied to the mold by any commonly used method, such as dipping, spraying, brushing, aerosol spraying, or coating with an impregnated cloth. Examples of molding materials molded using a mold coated with a mold release agent include resins such as polyurethane, polycarbonate, epoxy resin, phenol resin, polyimide resin, and vinyl chloride resin, natural rubber, chloroprene rubber, and fluorine rubber. Rubbers such as Next, the present invention will be explained with reference to examples. Example Synthesis of phosphonic acid monoisopropyl ester zinc salt Dissolve 10 parts by weight of phosphonic acid monoisopropyl ester in 10 to 20 parts by weight of isopropanol, and add 100 to 300 parts by weight of a water-isopropanol (10:1) mixed solvent while stirring well. Add part to it. Add a 10-50% aqueous sodium hydroxide solution dropwise to the resulting colloidal solution while stirring well.
Neutralizes pH from 2-3 to 7. This neutralization results in
A colloidal solution is turning into a true solution. To this, 6
An aqueous solution in which part by weight of zinc sulfate heptahydrate is completely dissolved in 50 to 100 parts by weight of water is added dropwise with thorough stirring to make the pH acidic again to 3 to 4, and the resulting precipitate is diluted with trichlorotrifluorochloride. Extracted with ethane. Preparation of mold release agent and evaluation of mold release properties Phosphonic acid monoisopropyl ester acid zinc salt synthesized as above and silicone oil (Shin-Etsu Chemical KF96-350 CS or X-
62-853) was dissolved in a Freon 113-isopropanol mixed solvent to prepare a mold release agent. This mold release agent is applied to the molding surface of a steel split mold in which bellows-shaped grooves are carved, and two of these split molds are used to form a cylindrical body having a bellows-shaped outer peripheral surface. After forming, preheat the mold to 70-80℃. Separately, add polyurethane prepolymer (100 parts by weight of aliphatic polyester with a molecular weight of about 10,000 and 30 parts by weight of diphenylmethane diisocyanate).
66g of foaming agent (prepared by mixing at 130℃, reacting, and then holding at 120℃) and 1g of blowing agent (prepared from 100 parts by weight of distilled water, 50 parts by weight of silicone foam stabilizer, and 3 parts by weight of catalyst) were quickly mixed. The mixture is stirred, poured into the mold, covered with a lid, and fixed with a clamp. After heating this at 100° C. for 10 minutes, the lid was removed and the mold was forcibly separated from each split mold to release the molded product, and the following five items were observed. Note that such operations are counted as one shot, and up to 10 shots (however, No. 8 and No. 8 in the table below)
12 (up to 3 shots) was repeated. (Evaluation of mold releasability) A: The molded product can be easily removed from the mold. B: The molded product has cracks or missing parts, and these remain attached to the mold (presence or absence of scum). Molding surface of the mold Remove debris such as burrs from the molded product that adheres to other parts (mainly the gaps between the split molds) using compressed air (2 to 3 kg/cm ³ ) ejected from a nozzle with a diameter of 5 mm. Judge based on how the residue is removed.A: There is no residue or it is easy to remove.B: It can be removed, but there are some areas that are difficult to remove with just compressed air.C: There are some areas that cannot be removed without rubbing by hand.D: There are quite a few areas that cannot be removed without rubbing with hands E: Cannot be removed even with hand rubbing (stains on the molded surface) A: Mirror-like after 5 shots or more B: Mirror-like after 4 shots C: Slightly cloudy from the first shot D: Gradually becomes whiter from the first shot E: Becomes whiter from the first shot (catalyst on the surface of the molded product) A: Feels dry with no stickiness B: There is no sticky feeling, but it feels damp. C: There is a slight sticky feeling. D: There is a very sticky feeling. E: There is a very sticky feeling, and it feels damp (visual appearance of the surface of the molded product). A: Quite a bit sticky. Smooth and glossy B: Smooth but not glossy C: Slightly uneven D: Considerably uneven E: Considerably uneven with defects such as cracks Composition of the mold release agent and evaluation results of its mold release properties are shown in the following table. Note that Nos. 1 to 7 are examples using phosphonic acid monoisopropyl ester acid zinc salt and silicone oil, and Nos. 8 to 7 are examples using phosphonic acid monoisopropyl ester acid zinc salt and silicone oil.
No. 11 is a comparative example using the corresponding acidic zinc salt of phosphonic acid and silicone oil, Nos. 12 to 13 are comparative examples using only silicone oil without using phosphonic acid (monoester) salt, and No. .14 is a comparative example in which only phosphonic acid zinc salt was used without using silicone oil.

【table】

Claims (1)

[Claims] 1. General formula (wherein, Rf is a _C1 - _C20 polyfluoroalkyl group, R' is a lower alkylene group, and R is a hydrocarbon group) or a salt thereof and a melting point of 100 ℃
A mold release agent containing the following wax or oil. 2. The mold release agent according to claim 1, wherein the oil is silicone oil.