Release agent for vulcanized rubber, aqueous dilution of release agent for vulcanized rubber, and method for manufacturing vulcanized rubber

Abstract

To provide mold-releasing agents for vulcanized rubbers having excellent inserting property, mold releasability, and washability all.SOLUTION: Mold-releasing agents for vulcanized rubbers of the present invention include the following component (A) and (B): (A) adducts which comprise polyoxyalkylene adducts of amine having weight-average molecular weights of under 5,000; and (B) polyoxyalkylene adducts of alcohol.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a mold release agent for vulcanized rubber, a water-diluted solution of the mold release agent for vulcanized rubber, vulcanized rubber, and a method for producing vulcanized rubber. [Background technology]

[0002] Vulcanized rubber molded products, such as rubber hoses, are widely used in the automotive and other sectors. In the manufacture of these vulcanized rubber molded products, for example, unvulcanized rubber is inserted into a mold such as a mandrel molded into a predetermined shape, vulcanized, and then the vulcanized rubber molded product is pulled out of the mold.

[0003] A mold release agent for vulcanized rubber is used to facilitate the insertion and removal of unvulcanized rubber from the mold. For example, Patent Document 1 proposes a compound obtained by randomly copolymerizing ethylene oxide and propylene oxide (average number of added moles 30 to 180) with an aliphatic alcohol having 3 to 10 carbon atoms as a mold release agent that simultaneously satisfies insertability, pullability and cleanability during molding, and also has excellent dimensional stability of rubber products (Claim 1, paragraph 0025, etc. of the same document). Patent Document 2 also proposes a mandrel mold release agent for hose manufacturing, which is a polyoxyethylene polyoxypropylene block copolymer with a molecular weight of 2000 to 4000, in which the proportion of oxyethylene groups in the total molecule is less than 20 to 40% (Claim 1, paragraph 0015, etc. of the same document). Furthermore, Patent Document 3 proposes the use of an AO (alkylene oxide) adduct of a diamine. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-114472 [Patent Document 2] Japanese Patent Publication No. 2004-306409 [Patent Document 3] Japanese Patent Application Publication No. 7-292236 [Overview of the Initiative]

Problems to be Solved by the Invention

[0005] For the mold release agent for vulcanized rubber, the ease of inserting unvulcanized rubber into a mold (e.g., a mold such as a mandrel) (insertability), the ease of separating the vulcanized rubber molded product from the mold (mold release property), and the ease of removing the mold release agent adhering to the surface of the separated vulcanized rubber molded product (cleanability) are required.

[0006] The mold release agents for vulcanized rubber described in Patent Documents 1 to 3 exhibit performance by blending a polymer activator obtained by adding an alkylene oxide to polyhydric alcohols. However, since the polymer activator becomes a highly viscous substance at high concentrations, it is difficult to clean and may damage the appearance of the vulcanized rubber. On the other hand, if the blending amount of polyhydric alcohols is suppressed to ensure cleanability, the mold release property may be impaired due to a decrease in the amount adhering to the vulcanized rubber. Therefore, there is a need for a mold release agent for vulcanized rubber that exhibits high adhesion prevention performance and slipperiness in vulcanized rubber while having high cleanability and not damaging the product appearance.

[0007] Therefore, an object of the present invention is to provide a mold release agent for vulcanized rubber, an aqueous dilution of the mold release agent for vulcanized rubber, vulcanized rubber, and a method for producing vulcanized rubber that are all excellent in insertability, mold release property, and cleanability.

Means for Solving the Problems

[0008] In order to achieve the above object, the mold release agent for vulcanized rubber of the present invention is characterized by containing the following components (A) and (B). (A) An adduct of an amine with polyoxyalkylene, having a weight average molecular weight of less than 5000 (B) An adduct of an alcohol with polyoxyalkylene

[0009] The aqueous dilution of the mold release agent for vulcanized rubber of the present invention is an aqueous dilution of the mold release agent for vulcanized rubber of the present invention diluted with water.

[0010] The first vulcanized rubber of the present invention is characterized by being obtained by applying the release agent for vulcanized rubber of the present invention or a water-diluted solution of the release agent for vulcanized rubber of the present invention to the interface between the unvulcanized rubber and the mold, and then vulcanizing it.

[0011] The second vulcanized rubber of the present invention is characterized in that the components (A) and (B) of the release agent for vulcanized rubber of the present invention are attached to its surface.

[0012] The method for producing vulcanized rubber according to the present invention is characterized by including a vulcanization step in which the unvulcanized rubber is vulcanized while the release agent for vulcanized rubber according to the present invention or a diluted aqueous solution of the release agent for vulcanized rubber according to the present invention is attached to the interface between the unvulcanized rubber and the mold. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a mold release agent for vulcanized rubber that is excellent in terms of insertability, release properties, and washability, a water-diluted solution of the mold release agent for vulcanized rubber, vulcanized rubber, and a method for producing vulcanized rubber. [Modes for carrying out the invention]

[0014] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following description.

[0015] [1. Release agent for vulcanized rubber] The mold release agent for vulcanized rubber of the present invention is characterized by containing the following components (A) and (B), as described above. (A) A polyoxyalkylene adduct of an amine having a weight-average molecular weight of less than 5000. (B) Polyoxyalkylene adducts of alcohols

[0016] [1-1. Polyoxyalkylene adducts] As described above, components (A) and (B) of the mold release agent for vulcanized rubber of the present invention are polyoxyalkylene adducts. In the present invention, the polyoxyalkylene of the polyoxyalkylene adduct is not particularly limited, but for example, the polyoxyalkylene may be a polymer of oxyalkylene groups having 2 to 4 carbon atoms. Furthermore, the polyoxyalkylene may or may not contain oxyethylene groups, or for example, oxypropylene groups. In the present invention, the polyoxyalkylene may be a polymer of only one type of oxyalkylene group, or a copolymer of multiple types of oxyalkylene groups. Furthermore, in the present invention, chain-like groups such as alkyl groups and alkylene groups may be linear or branched unless otherwise specified. Furthermore, in the present invention, if the polymer (for example, polyoxyalkylene) is a copolymer, it may be a block copolymer or a random copolymer unless otherwise specified.

[0017] In the present invention, the oxyethylene group (hereinafter sometimes referred to as "EO") is an atomic group represented by the following chemical formula (1). [ka]

[0018] In the present invention, the oxypropylene group (hereinafter sometimes referred to as "PO") is an atomic group represented by the following chemical formula (2). [ka]

[0019] In the components (A) and (B) of the vulcanizing rubber release agent of the present invention, the polyoxyalkylene may consist of only EO or only PO, but from the viewpoint of achieving both release properties and washability of the vulcanizing rubber release agent, it is preferable to include both EO and PO, and more preferably to consist of only EO and PO. In the polyoxyalkylene, the number of EO is preferably 20% or more, 30% or more, or 40% or more of the total number of oxyalkylene groups from the viewpoint of washability of the vulcanizing rubber release agent. Also, from the viewpoint of release properties (lubricity) of the vulcanizing rubber release agent, the number of EO is preferably 80% or less, 70% or less, or 60% or less of the total number of oxyalkylene groups. In the polyoxyalkylene, the number of PO is preferably 20% or more, 30% or more, or 40% or more of the total number of oxyalkylene groups from the viewpoint of release properties (lubricity) of the vulcanizing rubber release agent. Furthermore, from the viewpoint of the cleanability of the mold release agent for vulcanized rubber, the number of PO groups is preferably 80% or less, 70% or less, or 60% or less of the total number of oxyalkylene groups.

[0020] In the mold release agent for vulcanized rubber of the present invention, the mass ratio ((A) / (B)) obtained by dividing the mass of component (A) by the mass of component (B) is not particularly limited, but is preferably 0.05 to 30. From the viewpoint of washability, it is preferable that the mass ratio (A) / (B) is not too small. From the viewpoint of release properties, it is preferable that the mass ratio (A) / (B) is not too large. The mass ratio (A) / (B) may be, for example, 0.05 or more, 0.1 or more, or 0.2 or more, and may be, for example, 15 or less, 10 or less, or 5 or less.

[0021] [1-2. Polyoxyalkylene adducts of amines (A)] The component (A) (polyoxyalkylene adduct of amine) in the mold release agent for vulcanized rubber of the present invention is not particularly limited, but may be, for example, a polyoxyalkylene derivative represented by the following chemical formula (I).

[0022] [ka]

[0023] In the aforementioned chemical formula (I), each R is an arbitrary atom or group of atoms, for example, a hydrogen atom, an alkyl group (for example, an alkyl group having 1 to 18 carbon atoms), or a group represented by the following chemical formula (I-2), and may be the same or different, provided that at least one R is a group represented by the following chemical formula (I-2).

[0024] [ka]

[0025] In the above chemical formula (I-2), R 41 is an alkylene group (for example, an alkylene group with 2 to 4 carbon atoms), and n 41 R is a positive integer representing the degree of polymerization, and each R 41 They may be the same or different. In the above chemical formula (I), -R 41 The polymerization unit (oxyalkylene) represented by -O- can be, for example, EO, PO, or EO and PO. Also, the degree of polymerization n 41 For example, it can be 1 or more, or 100 or less.

[0026] Furthermore, the polyoxyalkylene adduct of the amine may be, for example, a polyoxyalkylene adduct of a polyamine (diamine, triamine, etc.). The polyoxyalkylene adduct of the diamine may be, for example, a polyoxyalkylene derivative represented by the following chemical formula (II).

[0027] [ka]

[0028] In the above chemical formula (II), R 50is an alkylene group (e.g., an alkyl group having 1 to 18 carbon atoms), each R is an arbitrary atom or atomic group, for example, a hydrogen atom, an alkyl group (e.g., an alkyl group having 1 to 18 carbon atoms), represented by the following chemical formula: (II-2), and they may be the same or different as long as at least one R is a group represented by the following chemical formula: (II-2).

[0029]

Chemical formula

[0030] In the above chemical formula (II-2), R 51 is an alkylene group (e.g., an alkylene group having 2 to 4 carbon atoms), n 51 is a positive integer representing the degree of polymerization, and each R 51 may be the same or different. In the above chemical formula (I), the polymerization unit (oxyalkylene) represented by -R 51 -O- may be, for example, EO, PO, or both EO and PO. Also, the degree of polymerization n 51 may be, for example, 1 or more and 100 or less.

[0031] The polyoxyalkylene derivative represented by the above chemical formula (II) may be, for example, a polyoxyalkylene derivative represented by the following chemical formula: (II-3).

Chemical formula

[0032] In the above chemical formula (II-3), A is 2 to 6, and a1, b1, c1, d1, m1, a2, b2, c2, d2, m2, a3, b3, c3, d3, m3, a4, b4, c4, d4, m4 are each a positive integer.

[0033] In the mold release agent for vulcanized rubber of the present invention, only one kind of the polyoxyalkylene adduct of the amine as the component (A) may be used, or a plurality of kinds may be used in combination.

[0034] In the mold release agent for vulcanized rubber of the present invention, the amine polyoxyalkylene adduct, which is component (A), may be, for example, an ethylenediamine polyoxyalkylene adduct.

[0035] In the mold release agent for vulcanized rubber of the present invention, the polyoxyalkylene adduct of amine, which is component (A), has a weight-average molecular weight of less than 5000, as described above. If the weight-average molecular weight of component (A) is 5000 or more, there is a problem that the cleanability of the mold release agent will decrease, so it is necessary that the weight-average molecular weight of component (A) be less than 5000. The weight-average molecular weight of component (A) may be, for example, 4500 or less, 4000 or less, or 3500 or less. The lower limit of the weight-average molecular weight of component (A) is not particularly limited, but may be, for example, 500 or more, 1000 or more, 1500 or more, or 2000 or more. From the viewpoint of mold release properties, it is preferable that the weight-average molecular weight of component (A) is not too small.

[0036] In the vulcanizing rubber release agent of the present invention, the content of the amine polyoxyalkylene adduct, which is component (A), is not particularly limited, but may be, for example, 0.5 to 95% by mass relative to the total mass of components other than water in the vulcanizing rubber release agent. The content of component (A) may be, for example, 93% by mass or less, 90% by mass or less, 88% by mass or less, or 85% by mass or less relative to the total mass of components other than water in the vulcanizing rubber release agent, and may be, for example, 1.0% by mass or more, 5.0% by mass or more, 10.0% by mass or more, or 20.0% by mass or more. From the viewpoint of washability, it is preferable that the content of component (A) is not too low. From the viewpoint of release properties, it is preferable that the content of component (A) is not too high.

[0037] In the vulcanizing rubber release agent of the present invention, the content of the amine polyoxyalkylene adduct, which is component (A), is not particularly limited, but may be, for example, 0.5 to 80% by mass with respect to the total mass of the vulcanizing rubber release agent. The content of component (A) may be, for example, 70% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less with respect to the total mass of the vulcanizing rubber release agent, and may be, for example, 1.0% by mass or more, 2.0% by mass or more, 3.0% by mass or more, or 5.0% by mass or more.

[0038] In this invention, the method for measuring the weight-average molecular weight of a substance is not particularly limited, but is not limited to the above-mentioned component (A). For example, the weight-average molecular weight can be measured by GPC (gel permeation chromatography) under the following analytical conditions. (Analysis conditions) Equipment: Waters e2695 Detector: Differential refractive index detector, Waters 2414 Columns: Three Waters HSPgel MB-H, RT2.0, and RT4.0 columns were connected in series. Solvent: tetrahydrofuran Flow rate: 0.3mL / min Temperature: 40℃

[0039] In the oxyalkylene adduct of the amine that is component (A), the oxyalkylene group may, for example, contain an oxyethylene group as described above. In that case, the content of the oxyethylene group is not particularly limited, but for example, with the total mass of the oxyalkylene group being 100% by mass, it is preferable that the content of the oxyethylene group in the oxyalkylene is 5 to 50% by mass. The content of the oxyethylene group in the oxyalkylene in component (A) may be, for example, 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, or 25% by mass or less, with the total mass of the oxyalkylene group being 100% by mass, and may be, for example, 8% by mass or more, 10% by mass or more, 12% by mass or more, or 15% by mass or more. From the viewpoint of washability, it is preferable that the content of the oxyethylene group is not too low. From the viewpoint of release properties, it is preferable that the content of the oxyethylene group is not too high.

[0040] [1-3. Polyoxyalkylene adducts of alcohols (B)] The component (B) (polyoxyalkylene adduct of alcohol) in the mold release agent for vulcanized rubber of the present invention is not particularly limited, but may be, for example, a polyoxyalkylene adduct of a monohydric alcohol (monool) or a polyoxyalkylene adduct of a polyhydric alcohol (e.g., diol, triol, etc.). Examples of the monohydric alcohol (monool) include methanol, ethanol, propanol, butanol, 2-ethylhexanol, nonanol, lauryl alcohol, and tridecanol. Examples of the polyhydric alcohol include ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, and sorbitol.

[0041] The polyoxyalkylene adduct of the monohydric alcohol (monool) may be, for example, a polyoxyalkylene derivative represented by the following chemical formula (III).

[0042] [ka]

[0043] In the above chemical formula (III), R 1 R is an alkyl group (for example, an alkyl group with 1 to 18 carbon atoms), 11 is an alkylene group (for example, an alkylene group with 2 to 4 carbon atoms), and n 11 R is a positive integer representing the degree of polymerization, and each R 11 They may be the same or different. In the above chemical formula (III), -R 11 The polymerization unit (oxyalkylene) represented by -O- can be, for example, EO, PO, or EO and PO. Also, the degree of polymerization n 11 For example, it can be 1 or more, or 500 or less.

[0044] Among the polyhydric alcohols, the polyoxyalkylene adduct of a dihydric alcohol (diol) may be, for example, a polyoxyalkylene derivative represented by the following chemical formula (IV).

[0045] [ka]

[0046] In the above chemical formula (IV), R 2 R is an alkylene group (for example, an alkyl group having 1 to 4 carbon atoms), 21 is an alkylene group (for example, an alkylene group with 2 to 4 carbon atoms), and n 21 R is a positive integer representing the degree of polymerization, and each R 21 They can be the same or different. 22 is an alkylene group (for example, an alkylene group with 2 to 4 carbon atoms), and n 22 R is a positive integer representing the degree of polymerization, and each R 22 They may be the same or different. In the above chemical formula (IV), -R 21 -O- and OR 22 The polymerization units (oxyalkylenes) represented by - may be, for example, EO, PO, or EO and PO. Also, the degree of polymerization n 21 and n 22Each of these can be, for example, 1 or more, or 400 or less.

[0047] Among the polyhydric alcohols, the polyoxyalkylene adduct of a trihydric alcohol (triol) may be, for example, a polyoxyalkylene derivative represented by the following chemical formula (V).

[0048] [ka]

[0049] In the above chemical formula (V), R 3 R is a saturated hydrocarbon group (for example, a saturated hydrocarbon group with 1 to 4 carbon atoms), 31 is an alkylene group (for example, an alkylene group with 2 to 4 carbon atoms), and n 31 R is a positive integer representing the degree of polymerization, and each R 31 They can be the same or different. 32 is an alkylene group (for example, an alkylene group with 2 to 4 carbon atoms), and n 32 R is a positive integer representing the degree of polymerization, and each R 32 They can be the same or different. 33 is an alkylene group (for example, an alkylene group with 2 to 4 carbon atoms), and n 33 R is a positive integer representing the degree of polymerization, and each R 33 They may be the same or different. In the above chemical formula (IV), -R 31 -O-, -OR 32 - and OR 33 The polymerization units (oxyalkylenes) represented by - may be, for example, EO, PO, or EO and PO. Also, the degree of polymerization n 31 , n 32 and n 33 Each of these can be, for example, 1 or more, or 300 or less.

[0050] Among the polyoxyalkylene adducts of the aforementioned alcohols, examples of monool polyoxyalkylene adducts include Adeka Carpol MH-1000. Examples of diol polyoxyalkylene adducts include Adeka Carpol PH-2000, Adeka Carpol PH-800, Braunon P-178, Epan U-108, Epan 785, and Leocon 2105E. Examples of triol polyoxyalkylene adducts include Adeka Carpol GH-10, Adeka Carpol GH-5, and Braunon CW-200. All names containing "Adeka Carpol" are product names of ADEKA Corporation. All names containing "Braunon" are product names of Aoki Oil & Fat Industry Co., Ltd., all names containing "Epan" are product names of Daiichi Kogyo Seiyaku Co., Ltd., and all names containing "Leocon" are product names of Lion Specialty Chemicals Co., Ltd.

[0051] In the mold release agent for vulcanized rubber of the present invention, the polyoxyalkylene adduct of alcohol, which is component (B), may be of one type or multiple types may be used in combination.

[0052] In the mold release agent for vulcanized rubber of the present invention, the weight-average molecular weight of the polyoxyalkylene adduct of alcohol, which is component (B), is not particularly limited, but may be, for example, 30,000 or less, 20,000 or less, 10,000 or less, 8,000 or less, or 6,000 or less. From the viewpoint of washability, it is preferable that the weight-average molecular weight of component (B) is not too large. The lower limit of the weight-average molecular weight of component (B) is not particularly limited, but may be, for example, 500 or more, 1,000 or more, 1,500 or more, or 2,000 or more. From the viewpoint of mold release properties, it is preferable that the weight-average molecular weight of component (B) is not too small.

[0053] In the vulcanizing rubber release agent of the present invention, the content of the polyoxyalkylene adduct of alcohol, which is component (B), is not particularly limited, but may be, for example, 0.5 to 95% by mass relative to the total mass of components other than water in the vulcanizing rubber release agent. The content of component (A) may be, for example, 93% by mass or less, 90% by mass or less, 88% by mass or less, or 85% by mass or less relative to the total mass of components other than water in the vulcanizing rubber release agent, and may be, for example, 1.0% by mass or more, 5.0% by mass or more, 10.0% by mass or more, or 20.0% by mass or more. From the viewpoint of washability, it is preferable that the content of component (B) is not too low. From the viewpoint of release properties, it is preferable that the content of component (B) is not too high.

[0054] In the vulcanizing rubber release agent of the present invention, the content of the polyoxyalkylene adduct of alcohol, which is component (B), is not particularly limited, but may be, for example, 0.5 to 80% by mass with respect to the total mass of the vulcanizing rubber release agent. The content of component (A) may be, for example, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less with respect to the total mass of the vulcanizing rubber release agent, and may be, for example, 0.8% by mass or more, 1.0% by mass or more, 1.2% by mass or more, or 1.5% by mass or more.

[0055] In the polyoxyalkylene adduct of the alcohol, which is component (B), the oxyalkylene group may, for example, contain an oxyethylene group, as described above. In that case, the content of the oxyethylene group is not particularly limited, but for example, with the total mass of the oxyalkylene group being 100% by mass, it is preferable that the content of the oxyethylene group in the oxyalkylene is 5 to 50% by mass. The content of the oxyethylene group in the oxyalkylene in component (B) may be, for example, 45% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less, with the total mass of the oxyalkylene group being 100% by mass, for example, 8% by mass or more, 10% by mass or more, 13% by mass or more, or 15% by mass or more. From the viewpoint of washability, it is preferable that the content of the oxyethylene group is not too low. From the viewpoint of release properties, it is preferable that the content of the oxyethylene group is not too high.

[0056] [1-4.Optional components] The mold release agent for vulcanized rubber of the present invention may or may not contain any other components besides component (A) and component (B).

[0057] [1-4-1. Dilution solvent] The mold release agent for vulcanized rubber of the present invention may or may not contain a diluent solvent. The diluent solvent is not particularly limited, but water is preferred from the viewpoint of cost, ease of handling, and solvent crack resistance of the mold release agent. The water is not particularly limited, but examples include tap water and deionized water. The water content is not particularly limited, but may be 98% by mass or less, 95% by mass or less, 93% by mass or less, or 90% by mass or less based on the total mass of the mold release agent for vulcanized rubber, for example, 5% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, or 40% by mass or more. From the viewpoint of cleanability, it is preferable that the water content is not too low. From the viewpoint of release properties, it is preferable that the water content is not too high.

[0058] The mold release agent for vulcanized rubber of the present invention may or may not contain a diluent other than water as the diluent solvent. As the diluent other than water, for example, alcohols such as methanol, ethanol, and isopropyl alcohol may be used alone or in combination with water.

[0059] [1-4-2. Nonionic surfactants] The aforementioned optional component may or may not include, for example, a nonionic surfactant. For example, it is preferable to include a nonionic surfactant as a release component in addition to component (A) and component (B) above, as this further improves cleaning performance. The reason for this is not entirely clear, but it is thought that by adding a nonionic surfactant, the viscosity of the release agent after the dilution solvent evaporates in the high-temperature vulcanization process becomes appropriately low, allowing for cleaning in a short time (high cleaning performance).

[0060] The nonionic surfactant is not particularly limited, but may be the same as the nonionic surfactant included as a release component in general release agents for vulcanized rubber. More specifically, it may be the same as the nonionic surfactant included as a release component in general release agents for mandrels (release agents for vulcanized rubber). The nonionic surfactant may be, for example, glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene polyoxypropylene glycol, polyoxyethylene alkylphenyl ether, etc. Among these, the nonionic surfactant represented by the following chemical formula (3) is preferred. RO-(AO) n -R (3)

[0061] In the above chemical formula (3), each R is a hydrogen atom, an aliphatic hydrocarbon group, or an acyl group, and may be the same or different from each other. However, at least one of each R is an aliphatic hydrocarbon group or an acyl group. The aliphatic hydrocarbon group may be, for example, an aliphatic hydrocarbon group having 8 to 18 carbon atoms. The acyl group may be, for example, an acyl group having 8 to 18 carbon atoms. The aliphatic hydrocarbon group may be linear or branched, and may be saturated or unsaturated. The acyl group may be linear or branched, and may be saturated or unsaturated. The number of carbon atoms in R is preferably 12 to 16, and more preferably 12 to 14, from the viewpoint of excellent dispersibility of component (A). AO represents an oxyalkylene group with 2 to 4 carbon atoms, and n is the average number of moles of AO added. n is preferably 1 to 30, and more preferably 3 to 25. Specifically, from the viewpoint of preventing a decrease in surfactant activity and a decrease in the dispersibility of component (A), it is preferable that n is 1 or greater (i.e., not 0). Furthermore, from the viewpoint of preventing a decrease in adhesion due to excessively high hydrophilicity, it is preferable that n does not exceed 30, and more preferably does not exceed 25.

[0062] In the mold release agent for vulcanized rubber of the present invention, one type of nonionic surfactant may be used, or multiple types may be used in combination.

[0063] In the mold release agent for vulcanized rubber of the present invention, the weight-average molecular weight of the nonionic surfactant is not particularly limited, but may be less than 5,000, for example. The weight-average molecular weight of the nonionic surfactant may be, for example, 4,500 or less, 4,000 or less, or 3,500 or less. From the viewpoint of cleaning performance, it is preferable that the weight-average molecular weight of the nonionic surfactant is not too large. The lower limit of the weight-average molecular weight of the nonionic surfactant is not particularly limited, but may be, for example, 500 or more, 1,000 or more, 1,500 or more, or 2,000 or more. From the viewpoint of mold release performance, it is preferable that the weight-average molecular weight of the nonionic surfactant is not too small.

[0064] In the vulcanizing rubber release agent of the present invention, the amount (content) of the nonionic surfactant is preferably not too high, from the viewpoint of achieving both release properties and cleaning properties at low concentrations. If the amount (content) of the nonionic surfactant is too high, the release agent may not be easily retained at the interface between the rubber and the mold, which may result in poor release properties. When the vulcanizing rubber release agent of the present invention contains the nonionic surfactant, the amount (content) may be, for example, 20% by mass or less, 15% by mass or less, 10% by mass or less, 5% by mass or less, or 2% by mass or less, relative to the total mass of the components other than water in the vulcanizing rubber release agent, for example, 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, or 1% by mass or more.

[0065] [1-4-3. Viscosity modifiers] The mold release agent for vulcanized rubber of the present invention may or may not contain a viscosity modifier as an optional component. For example, by adding a thickening agent as a viscosity modifier, the viscosity of the mold release agent for vulcanized rubber can be appropriately increased, further enhancing its mold release properties. The thickening agent is not particularly limited, but examples include polyethylene glycol mono or di fatty acid esters, xanthan gum, tamarind gum, propylene glycol, carboxymethylcellulose (CMC), sodium alginate, polyvinyl alcohol, and acrylic polymers.

[0066] In the mold release agent for vulcanized rubber of the present invention, the viscosity modifier may be of one type only, or multiple types may be used in combination.

[0067] In the vulcanizing rubber release agent of the present invention, the amount (content) of the viscosity modifier is preferably 1 to 15% by weight of the total vulcanizing rubber release agent, and more preferably 3 to 10% by weight. Furthermore, the amount (content) of the viscosity modifier is preferably 10 to 25% by weight of the total weight of the components of the vulcanizing rubber release agent excluding the diluent (e.g., water).

[0068] [1-4-4. Solubilizers] The mold release agent for vulcanized rubber of the present invention may contain, for example, a solubilizing agent. The solubilizing agent is not particularly limited, but examples include cationic surfactants, anionic surfactants, and nonionic surfactants. The nonionic surfactant may include, for example, the nonionic surfactants mentioned above.

[0069] Examples of cationic surfactants include alkylamine salts and quaternary ammonium salts. Examples of nonionic surfactants include alkyl ether EOPO adducts, alkylamine EOPO adducts, and polyoxyalkylene alkyl ether type nonionic surfactants. Examples of nonionic surfactants include the nonionic surfactants exemplified above. Examples of anionic surfactants include the following (1) to (4). (1) Carboxylic acid type anionic surfactants such as higher fatty acid salts, alkyl ether carboxylates, polyoxyalkylene ether carboxylates, alkyl (or alkenyl) amide ether carboxylates, and acylaminocarboxylates. (2) Sulfate ester type anionic surfactants such as higher alcohol sulfates, polyoxyalkylene higher alcohol sulfates, alkylphenyl ether sulfates, polyoxyalkylene alkylphenyl ether sulfates, and glycerin fatty acid ester monosulfates. (3) Sulfonic acid type anionic surfactants such as alkanesulfonates, α-olefin sulfonates, linear alkylbenzene sulfonates, α-sulfo fatty acid esters, and dialkyl sulfosuccinates. (4) Phosphate ester type anionic surfactants such as alkyl phosphate salts, polyoxyalkylene alkyl phosphate salts, polyoxyalkylene alkylphenyl phosphate salts, and glycerin fatty acid ester monophosphate salts

[0070] The counterions of the anionic surfactant are not particularly limited, but alkali metals such as sodium and potassium, and alkanolamines such as monoethanolamine and diethanolamine are preferred. These may be used individually or in combination of two or more.

[0071] As an anionic surfactant, dialkyl sulfosuccinate (alkyl sulfosuccinate salt) is preferred, and dioctyl sulfosuccinate sodium salt is more preferred, as it provides an anti-adhesion suspension with superior wettability to the surface of unvulcanized rubber.

[0072] In the mold release agent for vulcanized rubber of the present invention, the dissolution aid may be of one type only, or multiple types may be used in combination.

[0073] In the vulcanizing rubber release agent of the present invention, the amount (content) of the solubilizing agent is preferably 0.3 to 8% by weight of the total vulcanizing rubber release agent, and more preferably 0.3 to 6% by weight. Furthermore, the amount (content) of the solubilizing agent is preferably 3 to 20% by weight of the total weight of the components obtained by removing the diluent (e.g., water) from the vulcanizing rubber release agent, and more preferably 3 to 15% by weight.

[0074] [1-4-5. Antimicrobial agents, etc.] The mold release agent for vulcanized rubber of the present invention may or may not contain, as optional components, known mold release components such as antibacterial agents, nonionic surfactants, anionic surfactants, and silicones, as well as oils (mineral oil, vegetable oil, mineral oil, etc.), preservatives, rust inhibitors, etc. The antibacterial agent is not particularly limited, but examples include cyclic nitrogen-based antibacterial agents.

[0075] [2. Method for manufacturing release agents for vulcanized rubber] The method for producing the mold release agent for vulcanized rubber of the present invention is not particularly limited, but for example, it may be simply a matter of mixing each component. For example, from the viewpoint of ease of handling, each component may be dissolved or dispersed in a diluent solvent to form the mold release agent for vulcanized rubber of the present invention. In this case, the weight of components other than the diluent solvent may be, for example, 10 to 80% by weight of the total mold release agent for vulcanized rubber. The diluent solvent is not particularly limited, but as mentioned above, water is preferred from the viewpoint of cost, ease of handling, and solvent crack resistance of the mold release agent. The water is not particularly limited, but for example, as mentioned above, tap water, deionized water, etc. In addition to water, for example, alcohols such as methanol, ethanol, and isopropyl alcohol may be used alone or in combination with water.

[0076] When dissolving or dispersing each of the above components in a diluent solvent, heating, stirring, etc., may be performed as necessary. The heating temperature may be, for example, 20 to 90°C. The heating time may be, for example, 0.2 to 5 hours.

[0077] [3. Method of using release agents for vulcanized rubber, method of manufacturing vulcanized rubber, etc.] The method of using the vulcanizing rubber release agent of the present invention is not particularly limited, and can be used in the same way as general methods of using vulcanizing rubber release agents. Specifically, for example, as described above, the unvulcanized rubber is vulcanized with the vulcanizing rubber release agent of the present invention or the aqueous dilution of the present invention adhering to the interface between the unvulcanized rubber and the mold. As described above, vulcanized rubber can be produced by the method of producing vulcanized rubber of the present invention, which includes this vulcanization step.

[0078] The mold release agent for vulcanized rubber of the present invention may be used as is without dilution, or it may be diluted with water beforehand (before it adheres to the interface between the unvulcanized rubber and the mold) to prepare the aqueous dilution of the present invention. In the aqueous dilution of the present invention, the weight of components other than water may be, for example, 7 to 36% by weight or 10 to 30% by weight of the total aqueous dilution of the present invention.

[0079] The mold may be, for example, a molding die. The molding die is not particularly limited, but may be, for example, a metal mold, or a mandrel. The vulcanized rubber may be, for example, a vulcanized rubber molded product. The vulcanized rubber molded product is not particularly limited, but may be, for example, a rubber hose. The method of applying the vulcanized rubber release agent or the aqueous diluent of the present invention to the interface between the unvulcanized rubber and the mold is not particularly limited, and a general method or a similar method can be used. Specifically, examples include immersing the tip of the unvulcanized rubber (for example, an unvulcanized rubber hose) in the release agent, or applying the release agent to the interface in advance with a brush or spray. At this time, for example, the vulcanized rubber release agent or the aqueous diluent of the present invention is applied to one or both of the unvulcanized rubber and the mold. For example, if the mold is a mandrel and the unvulcanized rubber is an unvulcanized rubber hose, the release agent for vulcanized rubber of the present invention or the aqueous solution of the present invention may be applied to one or both of the outer surface of the mandrel and the inner surface of the hose by means of coating, immersion, etc.

[0080] The vulcanization step for vulcanizing the unvulcanized rubber may be, for example, a vulcanization molding step for vulcanizing the unvulcanized rubber. The vulcanization step is also not particularly limited and can be carried out in the same way as a general vulcanization step or vulcanization molding step for unvulcanized rubber. Specifically, for example, steam vulcanization, hot air vulcanization, etc., can be used. The method of vulcanizing a mandrel into which an unvulcanized hose has been inserted into a vulcanization can (a device that fills the device with steam or hot air to vulcanize the unvulcanized hose) with steam is called "steam vulcanization," and the method of vulcanizing with hot air is called "hot air vulcanization."

[0081] The types of vulcanized rubber that can be produced by the method for producing vulcanized rubber of the present invention are not particularly limited, but examples include natural rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), ethylene-propylene-diene copolymer rubber (EPDM), and vulcanizable rubbers such as NBR and polyvinyl chloride blend polymer (NBR / PVC). Furthermore, the vulcanized rubber that can be produced by the method for producing vulcanized rubber of the present invention is not particularly limited, but examples include rubber molded products such as rubber hoses and rubber seals.

[0082] The mold release agent for vulcanized rubber of the present invention offers several advantages. For example, its excellent insertability prevents deformation and wrinkling when inserting unvulcanized rubber (e.g., unvulcanized rubber hoses) into a mold (e.g., a mandrel). Furthermore, its high slipperiness of the release film and excellent mold release properties improve workability during removal after vulcanization. Additionally, its excellent washability allows for easy removal during the cleaning process, resulting in a superior appearance for vulcanized rubber products.

[0083] For example, by coating the interface between the hose and the mandrel with the release agent for vulcanized rubber of the present invention, contact between the mandrel and the rubber hose can be prevented, thereby preventing adhesion during vulcanization and providing slippage performance during insertion and removal. This ensures workability in the rubber hose manufacturing process and prevents defects such as deformation of the rubber hose product.

[0084] In the present invention, component (A) (a polyoxyalkylene adduct of an amine with a weight-average molecular weight of less than 5000) and component (B) (a polyoxyalkylene adduct of an alcohol) are used in combination. As mentioned above, polyoxyalkylene adducts of alcohols have the problem of becoming highly viscous at high concentrations. In contrast, the release agent for vulcanized rubber of the present invention maintains low viscosity even at high concentrations by using a polyoxyalkylene adduct of an amine with a low molecular weight as component (A). According to the release agent for vulcanized rubber of the present invention, for example, it is possible to exhibit high adhesion prevention performance and sliding performance, as well as high cleanability that allows for easy removal from vulcanized rubber products, and without impairing the appearance of the vulcanized rubber products. The release agent for vulcanized rubber of the present invention, for example, maintains adhesion prevention and insertability between the hole and the mandrel, and is easily washable, so it is possible to manufacture and provide high-quality rubber hoses without impairing the appearance of the product. Furthermore, as described above, the mold release agent for vulcanized rubber of the present invention is not limited to rubber hoses and mandrels, but may be applied to any rubber product and mold. [Examples]

[0085] Next, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

[0086] [Examples 1-11 and Comparative Examples 1-4] The release agents for vulcanized rubber of Examples 1 to 11 (Table 1) and Comparative Examples 1 to 4 (Table 2) were produced by mixing the components listed in Tables 1 and 2 below in the mass ratios indicated in Tables 1 and 2 below. The values ​​for each component in Tables 1 and 2 below represent the content (mass%) of each component when the total mass of the release agent for vulcanized rubber is set to 100% by mass. In Tables 1 and 2 below, (A) represents component (A) of the present invention, and (B) represents component (B) of the present invention.

[0087] [Method for measuring weight-average molecular weight] In Tables 1 and 2 below, the weight-average molecular weight was measured by GPC (gel permeation chromatography) under the following analytical conditions. (Analysis conditions) Equipment: Waters e2695 Detector: Differential refractive index detector, Waters 2414 Columns: Three Waters HSPgel MB-H, RT2.0, and RT4.0 columns were connected in series. Solvent: tetrahydrofuran Flow rate: 0.3mL / min Temperature: 40℃

[0088] [Method for evaluating the properties of release agents for vulcanized rubber] The properties (insertionability, release properties, and washability) of each mold release agent for vulcanizing rubber produced in the examples and comparative examples were measured and evaluated using the following method. These evaluation results are shown in Tables 1 and 2 below.

[0089] (1) Method for evaluating insertability and release properties An unvulcanized acrylic rubber hose, immersed in a release agent, was inserted into a molded hose mandrel coated with the release agent. The release agent was used undiluted with water. The ease of insertion was evaluated on a 5-point scale (1-5) based on the following criteria. 5: It can be inserted easily without resistance. 4: There is slight resistance during insertion, but it can be inserted easily. 3: There is some resistance during insertion, but it can be inserted. 2: There is significant resistance during insertion, but it can be inserted. 1: There is resistance during insertion and insertion is not possible.

[0090] Next, the unvulcanized rubber hose inserted into the mandrel was vulcanized by heating it at 150°C for 30 minutes to create a vulcanized rubber hose. After that, the vulcanized rubber hose was withdrawn from the mandrel. The ease of withdrawal (release) was defined as the release property and was evaluated on a 5-point scale from 5 to 1 according to the following criteria, similar to the insertion property. 5: It comes off easily without resistance when demolding. 4: There is slight resistance when demolding, but it comes off easily. 3: There is some resistance when demolding, but it will come off. 2: There is significant resistance when demolding, but it will come off. 1: There is resistance when demolding, and it won't come off.

[0091] (2) Method for evaluating cleanability The vulcanized rubber hoses obtained from the above evaluation of insertability and release properties were immersed in 40°C water for 2 minutes and then removed. After that, the surface of the vulcanized rubber hoses was visually inspected and evaluated on a three-point scale (○△×) according to the following criteria. ○: No mold release agent remains on the surface of the vulcanized rubber hose after 2 minutes of soaking. △: After 2 minutes of soaking, some mold release agent remains on the surface of the vulcanized rubber hose. ×: A large amount of mold release agent remains on the surface of the vulcanized rubber hose even after 2 minutes of soaking.

[0092] [Table 1]

[0093] The components (raw materials) listed in Table 1 above are those listed below. The same applies to Table 2 below. The "EO ratio" below refers to the mass percentage of oxyethylene groups when the total oxyalkylene groups are considered to be 100% by mass. Raw materials used (A) component A-1: Ethylenediamine polyoxyalkylene adduct (weight-average molecular weight 4650, EO ratio 40%), synthetic product. A-2: Ethylenediamine polyoxyalkylene adduct (weight-average molecular weight 3500, EO ratio 20%), synthetic product. A-3: Ethylenediamine polyoxyalkylene adduct (weight-average molecular weight 3100, EO ratio 10%), synthetic product. A-4: Propanediamine polyoxyalkylene adduct (weight-average molecular weight 3200, EO ratio 10%), synthetic product. A-5: Pentanediamine polyoxyalkylene adduct (weight-average molecular weight 3100, EO ratio 10%), synthetic product. (B) Component B-1: Polyoxyalkylene alcohol (weight-average molecular weight 4800, EO ratio 50%), synthetic product. B-2: Polyoxyalkylene glycol (weight-average molecular weight 3100, EO ratio 10%), synthetic product. B-3: Polyoxyalkylene glycol (weight-average molecular weight 2600, EO ratio 20%), synthetic product. B-4: Polyoxyalkylene glycerol (weight-average molecular weight 2600, EO ratio 50%), synthetic product. Other ingredients PEG distearate, synthetic product. Antimicrobial agent: Cyclic nitrogen-based antimicrobial agent.

[0094] [Table 2]

[0095] As shown in Table 1, the mold release agents for vulcanizing rubber of Examples 1 to 11, which contained components (A) and (B) of the present invention, exhibited excellent insertability, release properties, and cleanability. In contrast, the mold release agents for vulcanizing rubber of Comparative Examples 1 to 2, which contained only component (A) of the present invention and did not contain component (B), exhibited excellent cleanability but inferior insertability and release properties compared to the examples. On the other hand, the mold release agents for vulcanizing rubber of Comparative Examples 3 to 4, which contained only component (B) of the present invention and did not contain component (A), exhibited excellent insertability and release properties but inferior cleanability compared to the examples.

[0096] <Note> The above embodiments and some or all of the examples may also be described as follows, but are not limited to these. (Note 1) A mold release agent for vulcanized rubber, characterized by containing the following components (A) and (B). (A) A polyoxyalkylene adduct of an amine having a weight-average molecular weight of less than 5000. (B) Polyoxyalkylene adducts of alcohols (Note 2) The release agent for vulcanized rubber according to Appendix 1, wherein the content of the amine polyoxyalkylene adduct, which is component (A), is 0.5 to 95% by mass relative to the total mass of components other than water in the release agent for vulcanized rubber. (Note 3) The vulcanizing rubber release agent according to Appendix 1 or 2, wherein the content of the amine polyoxyalkylene adduct, which is component (A), is 0.5 to 80% by mass with respect to the total mass of the vulcanizing rubber release agent. (Note 4) The release agent for vulcanized rubber according to any one of the appendices 1 to 3, wherein the content of the polyoxyalkylene adduct of the alcohol, which is component (B), is 0.5 to 95% by mass relative to the total mass of components other than water in the release agent for vulcanized rubber. (Note 5) The vulcanizing rubber release agent according to any one of the appendices 1 to 4, wherein the content of the polyoxyalkylene adduct of the alcohol, which is component (B), is 0.5 to 80% by mass with respect to the total mass of the vulcanizing rubber release agent. (Note 6) A mold release agent for vulcanized rubber according to any one of the appendices 1 to 5, wherein the mass ratio ((A) / (B)) obtained by dividing the mass of component (A) by the mass of component (B) is 0.05 to 30. (Note 7) A mold release agent for vulcanized rubber according to any one of the appendices 1 to 6, wherein the oxyalkylene adduct of the alcohol, which is component (B), has a content of oxyethylene groups in the oxyalkylene of 5 to 50% by mass, with the total mass of the oxyalkylene groups being 100% by mass. (Note 8) A mold release agent for vulcanized rubber according to any one of the appendices 1 to 7, wherein the oxyalkylene adduct of the amine, which is component (A), has a content of oxyethylene groups in the oxyalkylene of 5 to 50% by mass, with the total mass of the oxyalkylene groups being 100% by mass. (Note 9) The mold release agent for vulcanized rubber according to any one of the appendices 1 to 8, wherein the oxyalkylene adduct of the amine that is component (A) is an ethylenediamine polyoxyalkylene adduct. (Note 10) A water-diluted release agent for vulcanizing rubber, obtained by diluting one of the release agents for vulcanizing rubber described in any of Appendix 1 to 9 with water. (Note 11) A vulcanized rubber characterized by applying a mold release agent for vulcanized rubber described in any of the appendices 1 to 9 or a water-diluted mold release agent for vulcanized rubber described in appendice 10 to the interface between the unvulcanized rubber and the mold, and then vulcanizing it. (Note 12) The aforementioned mold is a molding die, as described in Appendix 11, for vulcanized rubber. (Note 13) The vulcanized rubber as described in Appendix 12, wherein the molding die is a mandrel. (Note 14) A vulcanized rubber characterized in that the components (A) and (B) of the mold release agent for vulcanized rubber described in any of the appendices 1 to 9 are attached to the surface. (Note 15) The vulcanized rubber according to any one of the appendices 11 to 14, wherein the vulcanized rubber is a rubber hose. (Note 16) A method for producing vulcanized rubber, characterized by including a vulcanization step in which a release agent for vulcanized rubber described in any of the appendices 1 to 9 or a diluted solution of the release agent for vulcanized rubber described in appendice 10 is applied to the interface between the unvulcanized rubber and the mold, and the unvulcanized rubber is vulcanized. (Note 17) The manufacturing method described in Appendix 16, wherein the mold is a molding die. (Note 18) The manufacturing method according to Appendix 17, wherein the mold is a mandrel. (Note 19) The manufacturing method according to any one of the appendices 16 to 18, wherein the vulcanized rubber is a rubber hose.

Claims

1. It contains the following ingredients (A) and (B): A mold release agent for vulcanized rubber, characterized in that, in a polyoxyalkylene adduct of the alcohol component (B) described below, the content of oxyethylene groups in the oxyalkylene is 10 to 50% by mass, with the total mass of oxyalkylene groups being 100% by mass. (A) A polyoxyalkylene adduct of an amine having a weight-average molecular weight of less than 5000. (B) Polyoxyalkylene adducts of alcohols

2. The mold release agent for vulcanized rubber according to claim 1, wherein the mass ratio ((A) / (B)) obtained by dividing the mass of component (A) by the mass of component (B) is 0.05 to 30.

3. The mold release agent for vulcanized rubber according to claim 1, wherein in the oxyalkylene adduct of the amine which is component (A), the content of oxyethylene groups in the oxyalkylene is 5 to 50% by mass, with the total mass of oxyalkylene groups being 100% by mass.

4. The mold release agent for vulcanized rubber according to claim 1, wherein the oxyalkylene adduct of the amine, which is component (A), is an ethylenediamine polyoxyalkylene adduct.

5. A water-diluted release agent for vulcanizing rubber, obtained by diluting the release agent for vulcanizing rubber according to claim 1 with water.

6. A method for producing vulcanized rubber, characterized by including a vulcanization step of vulcanizing the unvulcanized rubber while the release agent for vulcanized rubber described in Claim 1 or the aqueous diluted solution of the release agent for vulcanized rubber described in Claim 5 is adhering to the interface between the unvulcanized rubber and the mold.

7. The method for producing vulcanized rubber according to claim 6, wherein the mold is a molding die.

8. The method for manufacturing vulcanized rubber according to claim 6, wherein the vulcanized rubber is a rubber hose.

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