WO2001021721A1

WO2001021721A1 - Coating material for coating molded object made by dip forming

Info

Publication number: WO2001021721A1
Application number: PCT/JP2000/006392
Authority: WO
Inventors: Tutomu Tawa; Chikako Koda; Hiroyuki Shiraki; Tamio Fukuda; Shouji Tamura
Original assignee: Takeda Chemical Industries, Ltd.
Priority date: 1999-09-22
Filing date: 2000-09-19
Publication date: 2001-03-29
Also published as: AU7316400A

Abstract

A molded object made by dip forming is coated with a coating material therefor which is obtained by dispersing or dissolving a nonionic polyurethane resin in water and contains polyoxyethylene chains in an amount of 3 to 60 wt.% based on the solid matter. Thus, a dip-formed object can be obtained which can be easily attached and detached without the need of using a lubricant such as talc or starch.

Description

Description Coating agent for coating dip moldings Technical field

TECHNICAL FIELD The present invention relates to a nonionic water-based polyurethane coating agent for coating a so-called dip-formed product such as a rubber glove and a finger cot. More specifically, a coating agent for coating a dip molded product comprising a nonionic polyurethane resin dispersed or dissolved in water and containing a polyoxyethylene chain in an amount of 3 to 60% by weight based on the solid content, and a coating agent for coating the same. It relates to a dip molded product coated with a coating agent. Background art

For medical, industrial, and household rubber gloves and finger cots, first immerse the mold in a salt coagulation solution and dry it, then immerse the mold in a rubber latex solution and dry to form a thin film on the mold. It is manufactured by a method of forming. A film-like molded product obtained by immersing such a mold in a rubber latex solution is called a dip molded product. When these dip moldings are made from natural rubber latex, there is a problem that they induce allergy. Another problem is that rubber gloves are difficult to put on and take off because of their large surface frictional resistance. In order to solve the difficulty of detachment, a method of spraying a powdery lubricant such as talc or starch on a dip molded product is generally employed. However, if lubricants are sprayed during manufacture or use, the splattered lubricants can damage the respiratory system of workers. In the case of surgical rubber gloves, the lubricant may fall from the glove to the patient's wound, causing granulation to form.

Therefore, it is required that medical gloves be powder-free, especially. As a countermeasure, powder-free methods such as halogenating the contact surface of the glove with the hand or treating the contact surface with the hand with a material containing silicone, etc., which has better lubricity than the base rubber, are used. Attempts have been made to improve lubricity while You. However, these methods have many problems such as complicated manufacturing processes, high cost, and environmental pollution. Also, US Pat. No. 5,088,125 describes a glove in which the contact surface between the glove and the hand is coated with ionic polyurethane for the purpose of preventing allergy induction and reducing frictional resistance. However, this branching technique also suffers from the problem of water resistance of the coated layer and the stability of the aqueous polyurethane dispersion, which is thought to be due to the reaction of metal ions such as Ca derived from the salt coagulation solution used in the production with the ionic polyurethane. There is a problem such as a decrease in performance.

The present invention relates to an aqueous polyurethane coating agent for coating a dip molded product for obtaining a dip molded product which is easily removable without using a lubricant such as talc or starch, and a dip molded product coated with the coating agent. To provide. Further, the present invention provides a coating liquid for coating a dip molded product that does not solidify due to metal ions in a salt coagulation solution contained in the molded product in a coating process of the dip molded product, and thus can withstand long-term use. It is in. Disclosure of the invention

In order to solve the above-mentioned problems, as a result of diligent research on a coating agent for coating a dip molded product, a nonionic polyurethane resin is dispersed or dissolved in water, and a polyxylene chain is obtained. Is stable over a long period of time without being affected by metal ions such as calcium ions contained in the coagulating liquid used in the dip molded product manufacturing process. It was found that the adhesion to the surface was also very good.

In addition, when the nonionic polyurethane resin has a polyoxytetralamethylene chain in the main chain of the molecule, the obtained coating has good slipperiness to the hand, is easy to attach and detach, and has a polyoxyethylene chain as a side chain. Alternatively, it was found that the coating at the end had excellent water resistance.

Furthermore, when the nonionic polyurethane resin had an elongation of 300% or more, it was found that the adhesion between the rubber layer and the coating layer was well maintained even when the dip-formed product expanded and contracted. . The present inventors have further studied based on these findings and completed the present invention. That is, the present invention (1) a coating agent for coating a dip molded product obtained by dispersing or dissolving a nonionic polyurethane resin in water and containing 3 to 60% by weight of a polyoxyethylene chain based on a solid content;

(2) The coating agent according to (1), wherein a polyoxyethylene chain is introduced into a side chain of the nonionic polyurethane resin.

(3) The coating agent according to the above (1), wherein a polyxylene chain is introduced into the main chain terminal of the nonionic polyurethane resin.

(4) The coating agent according to the above (1), wherein the nonionic polyurethane resin contains about 0 to 70% by weight of a polyoxytetralamethylene chain in a main chain of the molecule.

(5) The coating agent according to the above (1), wherein the nonionic polyurethane resin is obtained by reacting an alicyclic polyisocyanate compound with an active hydrogen compound.

(6) A dip molded article having a coating layer of the coating agent according to (1), and

(7) The dip molded product according to (6), wherein the elongation percentage of the coating layer is at least 300%.

The dip molded product coated with the coating agent of the present invention is obtained by immersing a mold in rubber latex and drying. Therefore, a method for producing a dip molded product will be described.

First, a mold made of ceramic or the like is immersed in a salt coagulation solution for rubber latex such as an aqueous solution of calcium nitrate, pulled up and dried. The mold to which the salt coagulation liquid has adhered is immersed in rubber latex. As the rubber latex, natural rubber or synthetic rubber is used. When the mold is lifted from the latex tank, dried, and washed with water to remove water-soluble components, a dip molded product having a thickness of usually 150 to 200 m is obtained on the mold.

The dip molded product thus obtained is immersed in the coating agent of the present invention before or after demolding, and dried to obtain a dip molded product coated with a polyurethane resin. Usually, the dip molded product is vulcanized to improve its physical properties, and the vulcanization may be before or after coating with the polyurethane resin. The coating agent of the present invention is used as an aqueous dispersion or solution containing usually 1 to 20% by weight, preferably 2 to 10% by weight, more preferably 3 to 6% by weight of solids. It is.

The thickness of the film formed on the dip-formed product by this coating agent is usually 50 m or less, preferably 0.5 to 20 m, more preferably 1 to 5 tm. Next, the coating agent of the present invention will be described.

The coating agent of the present invention can be produced by a known technique.

For example, a compound having at least two active hydrogen groups per molecule and a compound having at least two isocyanate groups per molecule are reacted in one or more stages and dissolved or dispersed in water. Can be obtained by

First, a compound having at least two active hydrogen groups per molecule will be described.

Examples of the compound having at least two active hydrogen groups per molecule include, for example, compounds having an active hydrogen, such as an amino group, a hydroxyl group, and a mercapto group.The reaction rate with the isocyanate group, Considering the later mechanical properties, compounds having a hydroxyl group are preferred. The number of functional groups of the compound having an active hydrogen group is preferably 2 to 6, and particularly preferably 2 to 4, from the viewpoint of maintaining good mechanical properties of the coating film. The molecular weight of the compound having an active hydrogen group is preferably from 200 to 100,000 from the viewpoint of the urethane bond concentration that gives the final coating film performance and the workability during production. 00-5, 000 is particularly preferred.

Examples of the compound in which the active hydrogen group is a hydroxyl group include, for example, polyester polyol, polyether polyol, polyether ester polyol, polyester amide polyol, acrylic polyol, polycarbonate polyol, polyhydroxyalkane, castor oil, polyurethane polyol, or a mixture thereof. No.

Specific examples of polyester polyols include, for example, dibasic acids such as terephthalic acid, isophthalic acid, adipic acid, azelaic acid, and sebacic acid, and their alkyl esters or mixtures thereof, and, for example, ethylene glycol, propylene glycol, diethylene glycol, Butylene glycol, neopentyl glycol, 1,6-hexane glycol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyxylene glycol, polyoxypropylene glycol Polyesters obtained by reacting glycols or mixtures thereof with glycols such as polyoxytetramethylene glycol or the like, for example, polycaprolactone, polyvalerolactone, poly (/ 3-methyl-a-valerolactone) and the like. And polyester polyols obtained by ring-opening polymerization of lactones.

Specific examples of polyether polyols include, for example, water, ethylene glycol, propylene glycol, trimethylolpropane, glycerin and other low molecular weight polyols used as initiators, for example, ethylene oxide, propylene oxide, and butylene oxide. And polyether polyols obtained by polymerizing xylan compounds such as oxides and tetrahydrofuran.

Specific examples of the polyether ester polyol include, for example, a reaction between a dibasic acid such as terephthalic acid, isophthalic acid, adipic acid, azelaic acid, sebacic acid, or a dialkyl ester thereof, or a mixture thereof, and the above polyether polyol. And a polyetherester polyol obtained by the reaction.

As a specific example of the polyesteramide polyol, in the polyesterification reaction, for example, an aliphatic diamine having an amino group such as ethylenediamine, propylenediamine, hexamethylenediamine or the like is used as a raw material, And the like, which are obtained by reacting additionally.

Specific examples of acryl polyol include polymerizable monomers having one or more hydroxyl groups in one molecule, such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, and the corresponding methacrylic acid derivatives. And, for example, those obtained by copolymerizing acrylic acid, methacrylic acid or esters thereof.

Specific examples of polycarbonate polyols include, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 9-nonane Or 1,8-nonanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol-A, or one selected from the group consisting of Two or more glycols and dimethyl carbonate, diphenyl carbonate, ethylene Examples thereof include those obtained by reacting with carbonate, phosgene, and the like.

Specific examples of the polyhydroxyalkane include isoprene, butadiene, or a liquid rubber obtained by copolymerizing butadiene with acrylamide.

Specific examples of the polyurethane borol include, for example, a polyol having a urethane bond in one molecule. Examples of the polyol include a polyether polyol, a polyester polyol, and a polyether ester having a molecular weight of 200 to 50,000. Those obtained by reacting a polyol or the like with a compound having at least two isocyanate groups per molecule as described below at a mole number of (NCO group or ZOH group) of less than 1, preferably 0.9 or less. Is mentioned.

Further, a low molecular weight polyol may be mixed in addition to the polyol described above. Specific examples of these low molecular weight polyols include, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol. , 1,9-nonanediol, 1,8-nonanediol, neopentyl glycol, 2-methylpentanediol, 3-methylpentanediol, 3,3-dimethylolheptane, 2,2,4-trimethyl-1,3-pentane Glycols used in the production of polyester polyols such as diols, 2,4-getyl-1,5-pentanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc. And glycerin, trimethylolpropane, pentaerythritol, etc. Compounds.

The compounds having various active hydrogen groups may be used alone or in combination of two or more.

By using polyoxytetramethylene glycol as one of the compounds having an active hydrogen group, a polyoxytetramethylene chain can be introduced into the molecule, and a good sliding property required for the coating agent of the present invention can be obtained. Sex can be achieved. The content of polyoxytetramethylene chains required to achieve good lubricity is from 10 to 70% by weight, preferably from 20 to 60% by weight. Next, a compound having at least two isocyanate groups per molecule will be described.

Examples of the compound having at least two isocyanate groups per molecule used in the present invention include, for example, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, and pentamethylene diisocyanate. Isocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2, Aliphatic dissociates such as 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-dicyanate methylcaproate, for example, 1,3-cyclopentanediiso Cyanate, 1,4-cyclohexanediisocyanate, 1,3-cyclohexanediisocyanate, 3-isocyanatomethyl-3,5,5_trimethylcyclohexyl Isocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), Methyl 1,2,4-cyclohexanediisocyanate, Methyl 1,2,6-cyclohexanediisocyanate, 1 Alicyclic diisocyanates such as 1,4-bis (isosinate methyl) cyclohexane, 1,3-bis (isosinate methyl) cyclohexane, norbornene diisocyanate, for example, m-phenylene Range isocyanate, p-phenylene diisocyanate, 4,4 'diphenyl diisocyanate, 1,5_ naphthalene diisocyanate, 4, 4' diphenyl methane diisocyanate 2,4—or 2,6—tolylenediocyanate or a mixture thereof, 4,4′-toluidine diisocyanate, dianisidine diisocynate, 4_4 ′ diphenylate Aromatic diisocyanates such as rudiisocyanate, for example, 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω, ω'-diisocyanate-1,4-getyl benzene, 1,3— or 1 , 4-bis (1-isocyanate-1-methylethyl) benzene or an araliphatic diisocyanate such as a mixture thereof, for example, triphenylmethane-4,4 ', 4 "-triisocyanate, 1,3,5-triisocyanate Benzene, 2,4,6-trisocyanatotoluene, 1,3,5-triisocyanate such as triisocyanatohexane, for example, 4,4'-diphenyl dimethylethane 1,2 '-5,5'- Tetraisoshi, such as Tetraisocyanate Polyisocyanate monomer such as polyisocyanate, dimer, trimer, biuret, arophanate, carbodiimide, carbodiimide, and carbon dioxide gas derived from the above-mentioned polyisocyanate monomer, and 2,4, 6-year-old polyisocyanate having an oxatriazine trion ring, for example, ethylene glycol, propylene glycol, butylene glycol, 1,6-hexane glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3 '' Low molecular weight polyols with a molecular weight of less than 200, such as dimethylol heptane, cyclohexanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, etc. Adducts of the above-mentioned polyisocyanate monomers, for example, polyester polyols, polyether polyols, polyether ester polyols, polyester amide polyols, polycaprolactones having a molecular weight of 200 to 200,000 described above. Adducts of the above polyisocyanate monomers, such as polyols, polyvalerolactone polyols, acrylic polyols, polycarbonate polyols, polyhydroxyalkanes, castor oil, and polyurethane polyols.

Although compounds having these various isocyanate groups are used, an alicyclic isocyanate compound is preferable in order to impart the coating film properties and water resistance required for the polyurethane used in the present invention.

In order to dissolve or disperse the polyurethane prepolymer in water, a polyoxyethylene chain, which is a nonionic hydrophilic group, is introduced into the polyurethane prepolymer, or a nonion having a polyoxetylene chain is used. A surfactant is added.

In order to introduce a polyoxetylene chain into a polyurethane molecule, for example, at least one compound containing at least one active hydrogen group and a polyxylene chain in the molecule is used in the production of the polyurethane prepolymer. do it. In addition, as a method for introducing a polyxylene chain, the polyoxetylene chain-containing compound may be reacted simultaneously during the synthesis of the polyurethane prepolymer, reacted after the synthesis of the polyurethane prepolymer, or may be reacted with the polyurethane prepolymer. The reaction may be performed after dispersing in water. As a polyoxyethylene chain-containing compound, A polyoxyethylene-polyoxyalkylene copolymer having a molecular weight of 300-10000 and containing at least 3% by weight or more of a repeating unit of a styrene chain and having at least one active hydrogen group in the polymer. And polyetherester polyols obtained by copolymerizing these nonionic group-containing compounds.

In copolymerization, these polyoxyethylene chain-containing compounds can be used alone or in combination of two or more. Further, as the polyoxyethylene chain-containing compound, a compound modified in advance may be used.

In order to further improve the solubility or dispersibility of the polyurethane prepolymer containing a polyoxyethylene chain in water, or to dissolve or disperse a polyurethane prepolymer having no hydrophilic group in the molecule in water. For this purpose, a nonionic surfactant containing a polyoxyethylene chain may be used.

Examples of the nonionic surfactant containing a polyoxetylene chain include polyoxyethylene nonylphenyl ether and polyoxyethylene one-year xylene propylene block copolymer. A soap-free type containing no surfactant is preferred from the viewpoints of performance such as water resistance and solvent resistance.

The polyoxyethylene chain, which is a nonionic hydrophilic group, is required to be 3 to 60% by weight, preferably 5 to 40%, more preferably 7 to 30%, based on the solid content of the polyurethane resin. If it is less than 3% by weight, good water dispersibility is hardly obtained, and if it is more than 60% by weight, water resistance cannot be obtained.

Further, it is preferable that the poly (xylene) chain is introduced into a side chain or a terminal of the polyurethane molecule. By being introduced into the side chain or the terminal, good water dispersibility can be obtained, and the physical properties of a coating film required as a coating agent for rubber products can be easily achieved.

The reaction between the isocyanate compound and the active hydrogen-containing compound, that is, the urethanization reaction, is usually performed at room temperature to 100 ° C, and if necessary, a known organic acid, tin, lead, or amine compound is used. Can be used.

Examples of the amine-based urethanization catalyst include triethylamine, N, N-dimethylcyclohexylamine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N ' 1,3-Diamine, N, N, N ', N'-tetramethylhexane-1,6-diamine, N, N, N', N, ', N''pentamethylmethylentriamine, N, N, N', N ", N '' Pentamethyldipropylene triamine, Tetramethyldanidine, Triethylenediamine, N, N 'Monodimethylbiperazine, N-methyl-N' — (2-Dimethylamino) ethylbiperazine, N-methyl Morpholine, N- (N ', N'-dimethylaminoethyl) morpholine, 1,2-dimethylimidazole, 1,8-diazabicyclo (5.4.0) pendene 7-ene (and its phenol and octyl salts) ), Diazabicyclo- (2.2.2.) Monooctane (DABCO), dimethylaminoethanol, dimethylaminoethoxyethanol, N, N, N'trimethylethylaminoethylethanolamine, N-methyl- N '-(2-hydroxyethyl) piperazine, N- (2-hydroxyethyl) -molar phosphorus, bis- (2-dimethylaminoethyl) ether, ethylene glycol bis (3-dimethyl) amino Propyl ether, bis- (morpholinoethyl) ether, bis- (2,6-dimethylmorpholinoethyl) ether and the like.

Examples of tin-based urethanization catalysts include, for example, stannath acetate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin mercaptide, Dioctyl tincture carboxylates. Examples of the lead-based urethanization catalyst include lead 2-ethylhexanoate.

Other urethanization catalysts include, for example, phenylmercury propionate as a mercury-based catalyst.

When synthesizing the polyurethane prepolymer, an organic solvent can be used to make the reaction system uniform or to adjust the viscosity to an appropriate level.

For example, acetone, methylethyl ketone, acetate nitrile, N-methylpyrrolidone, dioxane, ethyl acetate and the like can be mentioned. Those having relatively high solubility in water are preferred. The amount of the organic solvent based on the reaction raw materials is preferably about 3 to 50% by weight.

The polyurethane pre-polymer is obtained by using a homogenizer, a mixer or the like in water. Dissolve or disperse in This temperature is preferably from 5 ° C to 70 ° C, and more preferably from room temperature to 50 ° C, to ensure workability. The concentration of the aqueous polyurethane composition when dispersed in a medium such as water is preferably from 10 to 50% by weight so as not to increase the viscosity so much and to maintain storage stability.

It is also possible to increase the molecular weight by reacting another chain extender. As the chain extender, for example, a known polyamine compound or the like is used. Examples of the polyamine compound include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylbiperazine, isophoronediamine, and 4,4′-dicyclohexylmethanediamine. Amine, 3,3'-dimethyl-4,4'Diamines such as dicyclohexylmethanediamine, 1,4-cyclohexanediamine, diethylenetriamine, dipropylenetriamine, triethylenetetraamine, tetraethylene Compounds having an amino group and a hydroxyl group, such as polyamines such as pentamine, hydroxyethylhydrazine, hydroxyethylethylentriamine, 2-[(2-aminoethyl) amino] ethanol, and 3-aminopropanediol; Hydrazines, acid hydrazides, aminosilanes and the like can be mentioned. In addition, those derived into a polyamine compound by various reactions may be used. The polyamine compounds are used alone or as a mixture of two or more.

The polyurethane coating agent used in the present invention may be a leveling agent, a slip agent, a thickening agent, a defoaming agent, a film-forming aid, etc., within a range that does not reduce the physical properties of the resin according to the purpose. May be added.

The polyurethane coating agent thus obtained is stable against salt coagulation liquid, and provides a rubber product having good lubricity without using powder by coating a rubber base material. be able to. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail with reference to Examples, Comparative Examples, and Test Examples, but the present invention is not limited to only the following Examples. In the following, parts and% are values based on weight. Example 1

(1) Synthesis of polyisocyanate containing mono-isocyanate (A 1)

Hexamethylene diisocyanate (Takenate T-700, manufactured by Takeda Pharmaceutical Co., Ltd.) while introducing nitrogen gas in a reactor equipped with a thermometer, nitrogen gas inlet tube and stirrer. 1 4 parts, 5 2,000 methoxypolyethylene glycol (MPEG-1 000, manufactured by Toho Chemical Co., Ltd.) heated to 5 CTC, 3 72.86 parts were charged, and 8 (6 After the reaction reached a predetermined content of the isocyanate group, unreacted hexamethylene diisocyanate was removed to obtain a polyisoethylene ethylene chain-containing monoisocyanate (A 1).

(2) Synthesis of diol (A 2) containing polyoxyethylene chain

In a reactor equipped with a thermometer, a nitrogen gas inlet tube and a stirrer, 80.56 parts of diethanolamine were charged at room temperature while introducing nitrogen gas. While cooling, 91.44 parts of the above polyoxyethylene chain-containing monoisocyanate (A 1) was added,

The reaction was performed at 6 CTC for 3 hours. Urea bond formation was confirmed by IR, and a polyoxyethylene chain-containing diol (A2) was obtained.

(3) Synthesis of polyurethane coating agent (B1)

In a reactor equipped with a thermometer, a nitrogen gas inlet tube and a stirrer, while introducing nitrogen gas, 06.94 parts of isophorone diisocyanate, a molecular weight of 2,000 liters of methylene glycol having a molecular weight of 2,000. (PTG-2000 SN, manufactured by Hodogaya Chemical Co., Ltd.) 14.25 parts, neopentyl glycol 18.40 parts, the above-mentioned poly (ethylene glycol) chain-containing diol (A2) 93.41 parts, N-methyl 90.00 parts of pyrrolidone and 0.072 parts (0.02 phr) of Stanasoctate (Stannoct) were charged.

7 (After reaction with TC for 6 hours, it was confirmed that the content of the isocyanate group had reached a predetermined value, and a polyurethane prepolymer was obtained.

Next, 68.03 parts of the above polyurethane prepolymer was added to 600.00 parts of water while stirring at a high speed, and dispersed in water. Thereafter, a solution of 5.58 parts of hydrazine monohydrate dissolved in 26.4 parts of water was gradually added to the urethane prepolymer aqueous dispersion with high-speed stirring. After stirring for 2 hours, add 1.00 part of a leveling agent (Taishi Rufin E1004, manufactured by Nissin Chemical Industry Co., Ltd.) A tan coating agent (B 1) was obtained. The obtained polyurethane coating agent (B 1) is a stable aqueous dispersion having a solid content of 30%, and has a polyoxyethylene chain content of 20.0% (per solid content) and a polyoxytetramethylene chain content. Was 39.0% (per solid) and the viscosity was 70 mPa · s. Further, the elongation of the obtained coating film was 400%.

Example 2

Synthesis of polyurethane coating agent (B2)

In a reactor equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, while introducing nitrogen gas, 805.6 parts of isophorone diisocyanate, polyoxytetramethylene glycol (PTG having a molecular weight of 2,000) was used. — 2000 SN, manufactured by Hodogaya Chemical Co., Ltd.) 6 52.68 parts, neopentyl glycol 170.02 parts, polyoxyethylene chain-containing diol (A2) 581.69 parts, stannoct 0.42 parts (0 .02 Phr) and reacted at 70 C for 6 hours, and it was confirmed that a predetermined content of the isocyanate group was reached. Next, 4750 parts of water was gradually added to the polyurethane prepolymer, and the polyurethane prepolymer was completely dispersed in water. Thereafter, a solution prepared by dissolving 5.1.12 parts of hydrazine monohydrate in 500 parts of water was gradually added to the aqueous dispersion of the urethane prepolymer while stirring. After stirring was continued for 2 hours, 7.50 parts of a leveling agent (Olfin E1004, manufactured by Nissin Chemical Industry Co., Ltd.) was added to obtain a polyurethane coating agent (B2). The resulting polyurethane coating agent (B2) is a stable aqueous dispersion having a solid content of 30%, and has a polyoxyethylene chain content of 20.5% (per solid content) and a polyoxytetramethylene chain content of 29.2% (per solid), and the viscosity was 5 OmPas. The elongation of the obtained coating film was 350%.

Example 3

Synthesis of polyurethane coating agent (B3)

Hydrogenated xylylene diisocyanate (Takenate 600, manufactured by Takeda Pharmaceutical Co., Ltd.) while introducing nitrogen gas in a reactor equipped with a thermometer, nitrogen gas inlet tube, and stirrer 1 22. 52 Parts, polycarbonate diol with a molecular weight of 2,000 (Carposol D-2000, manufactured by Toagosei Co., Ltd.) 1 43.53 parts, trimethylol Mouth bread 2.35 parts, neopentyldaricol 29.9 parts, 45.69 parts of the above-mentioned polyoxyethylene chain-containing diol (A2), 56.00 parts of N-methylpyrrolidone, 0.069 parts of stannoct 02 phr) and reacted at 70 ° C. for 6 hours. After confirming that a predetermined isocyanate group content was reached, a polyurethane prepolymer was obtained.

Next, 96.06 parts of the above polyurethane prepolymer was added to 500.00 parts of water while stirring at a high speed, and dispersed in water. Thereafter, a solution obtained by dissolving 9.39 parts of hydrazine monohydrate in 94.55 parts of water was gradually added to the aqueous dispersion of the urethane prepolymer while stirring at a high speed. After stirring was continued for 2 hours, 1.00 part of a silicon-based leveling agent BYK-302 (manufactured by Big Chemie Co., Ltd.) was added to obtain a polyurethane coating agent (B3). The obtained polyurethane coating agent (B3) is a stable aqueous dispersion having a solid content of 35%, a polyoxyethylene chain content of 10.2% (per solid content), and a viscosity of 50 mPa * s. Met. The elongation of the obtained coating film was 330%.

Example 4

Synthesis of polyurethane coating agent (B4)

In a reactor equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, while introducing nitrogen gas, consist of 13.4 1.48 parts of isophorone diisocyanate, adipic acid and 1,4-butanediol 106.78 parts of polyester polyol having a molecular weight of 2,000, 27.82 parts of neopentyldaricol, 93.93 parts of the above polyoxyethylene chain-containing diol (A 2), 90.00 parts of acetate ditriol, Stanok 0.072 parts (0.02 phr) of the mixture was charged, and the mixture was reacted with 7 (TC for 6 hours). After that, it was confirmed that a predetermined content of isocyanate group was reached, and a polyurethane prepolymer was obtained. 365.97 parts of the above polyurethane prepolymer was added to 600.00 parts of water while stirring at a high speed, and dispersed in water.7.22 parts of hydrazine monohydrate were added to 26.8 parts of water. The dissolved matter is stirred at high speed while the water content of the urethane prepolymer is After stirring for 2 hours, 1.0 part of a polyoxyethylene leveling agent (Olfin E110, manufactured by Nissin Chemical Industry Co., Ltd.) was added. After removing acetate nitrile at 55 ° C under reduced pressure, water was removed. In addition, the concentration was adjusted to obtain a polyurethane coating agent (B4). This polyurethane coating agent (B4) is a stable aqueous dispersion having a solid content of 30%, a polyoxyethylene chain content of 20.0% (per solid content), and a viscosity of 30 mPa · s. Was. The elongation of the obtained coating film was 450%.

Example 5

Synthesis of polyurethane coating agent (B5)

In a reactor equipped with a thermometer, a nitrogen gas inlet tube and a stirrer, introduce nitrogen gas and introduce 52.03 parts of isophorone diisocyanate, polyoxytetramethylene glycol (PTG) having a molecular weight of 2,000. — 200 SN, manufactured by Hodogaya Chemical Co., Ltd. 1 4 1.53 parts, neopentyl dalicol 36.87 parts, methoxypolyethylene lendaricol with a molecular weight of 1,000 (MP EG—1000, Toho Chemical ( 62.27 parts, Acetonitrile 69.30 parts, Stanok 0.02 3 parts (0.02phr), react at 70 ° C for 5 hours, and then react with the specified isocyanate. It was confirmed that the group content had been reached, and a polyurethane prepolymer was obtained.

Next, 45.92 parts of the above urethane prepolymer was added to 110 parts of water while stirring at a high speed, and dispersed in water. Thereafter, a solution prepared by dissolving 1.37 parts of ethylenediamine in 3.10. Parts of water was gradually added to the aqueous dispersion of urethane prepolymer by stirring at a high speed. After continuing stirring for 2 hours, 1.000 parts of a leveling agent (Olfin E 1004, manufactured by Nissin Chemical Co., Ltd.) was added. Thereafter, the acetate was removed under reduced pressure at 55, and water was added to adjust the concentration to obtain a polyurethane coating agent (B5).

This polyurethane coating agent (B5) is a stable aqueous dispersion having a solid content of 35%, and has a polyoxyethylene chain content of 15.2% (per solid content) and a polyoxytetraethylene chain content of 35.50%. 0%, viscosity was 45 mPa · s. Comparative Example 1

Synthesis of polyurethane coating agent (C 1)

In a reactor equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, introduce nitrogen gas while introducing nitrogen gas. 27 6.71 1 part, adipic acid, neopentylda alcohol, 1, 6- Polyester made of xandiol with molecular weight of 1,000 Polyol 355.48 parts, neopentyl glycol 6.17 parts, 1,6-hexanediol 14.00 parts, neopentyl glycol 6.17 parts, 2,2-dimethylolpropionic acid 47.63 parts , Asetoni Bok Lil 300.00 parts Sutanoku Bok 0.1 4 parts were charged (0. 02 phr), after reaction for 8 hours at 70 ^e C, to confirm that it has reached the predetermined Isoshiane Bokumoto content Thus, a polyurethane prepolymer was obtained.

Next, 35.98 parts of triethylamine was added to 1,000,000 parts of the obtained prepolymer to neutralize it. Hydrazine monohydrate was dissolved in 770.00 parts of water, and 454.63 parts of neutralized prepolymer was gradually added thereto, and the polyurethane was completely dispersed in water. Thereafter, the acetate was removed at 55 ° C. under reduced pressure, and water was added to adjust the concentration. By this operation, a polyurethane coating agent (C 1) was prepared as a stable aqueous dispersion having a solid content of 30%. The elongation of the obtained coating film was 300%.

Comparative Example 2

Synthesis of polyurethane coating agent (C2)

In a reactor equipped with a thermometer, a nitrogen gas inlet tube and a stirrer, while introducing nitrogen gas, 52.66 parts of 4,4'-diisocyanatodiphenylmethane, adipic acid and 1,6 —Polyester polyol consisting of hexanediol with a molecular weight of〗 000, 150.34 parts, 500.00 parts of tetrahydrofuran (THF), 0.14 parts of Stanoct (0.02 phr), and charged at 70 ° C for 5 hours After the reaction, it was confirmed that a predetermined content of the isocyanate group was reached, and a polyurethane prepolymer was obtained. Then, the obtained prepolymer was cooled to room temperature, and 73 parts of a 1.6% by weight acetone solution of ethylenediamine, 19.4 parts of a 2 M lysine solution in sodium salt, and 1 M parts of a 2 M taurine solution were stirred with high speed. 1.46 parts of an aqueous solution of lithium salt and 800.00 parts were further added, and the polyurethane was completely dispersed in water. Thereafter, THF and acetone were removed at 55 ° C under reduced pressure to obtain a polyurethane coating agent (C2). The elongation of the obtained coating film was 300%.

Test example 1

(1) Production of test latex membrane First, a 100-band X 200 Okiseki plate was preheated to 70 ° C and immersed in the following salt coagulation solution for 1 minute. After the unglazed plate was pulled out of the salt coagulation solution, it was allowed to stand for 3 minutes and immersed in the following latex compounding solution for 2 minutes. After lifting the unglazed plate from the latex formulation, it was washed with water for 3 minutes to remove water-soluble components. Then, it was dried at 70 ° C. for 30 minutes to prepare a test latex film.

Composition of salt coagulation liquid (combination: weight ratio)

C a (N 0 ₃ ) 30.0

Surfactant

(Epan 720, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 0 5

C a C0 ₃ 5 0

Water 64 5

1000.0 total composition of diving liquid (mixing ratio: weight ratio)

45% NBR latex 222.0

50% vulcanizing agent 8.0

S 1.0

Z n 0 0.5

B z (Z n B DC) 0.5

T i 0 ₂ 2.0

Wed 4.0

Water 0.0

Total 300.0

NBR latex is Closlen Ν Κ— 2 15 (manufactured by Takeda Pharmaceutical Co., Ltd.)

(2) Coating method of polyurethane coating agent

The test latex membranes prepared above were prepared by mixing polyurethane coatings of Examples 1 to 5 and Comparative Example 2 with water so as to have a solid content of 5%. It was immersed in a single solution for 2 minutes. Thereafter, the test latex film was pulled up from the polyurethane coating solution, and dried at 80 ° C. for 1 minute using a drier.

Evaluation

The stability of the salt coagulation solution, the water resistance, and the slipperiness of the polyurethane coating test latex film of each of the obtained polyurethane coating solutions were evaluated by the following methods. The results are shown in Table 1.

In addition, the latex film which was not coated with the polyurethane coating liquid was used as a reference example 1, and the latex film of Reference Example 1 in which corn starch powder was sprayed on the surface was used as Reference Example 2 to evaluate the slipperiness.

(1) Evaluation of salt coagulation liquid stability

To 200 g of each polyurethane coating solution prepared with water so that the polyurethane coating agent has a solid content of 5%, 10 g of the above-mentioned salt coagulation solution for producing a latex film is dropped and stirred, and the presence or absence of precipitation of aggregates is visually observed. Confirmed.

(2) Evaluation of water resistance

The polyurethane coating solution was applied on a glass plate with a bar coater so as to have a thickness of about 2, which was immersed in water for 1 day, and the appearance of the coating film was visually evaluated.

(3) Evaluation of slipperiness of polyurethane coated surface

The slip property was evaluated by a finger touch and a surface measuring device.

In the finger touch, skin smoothness was relatively evaluated in four stages, where the untreated latex film (Reference Example 1) had a slip property of D and the powdered latex film (Reference Example 2) had a slip property of A. .

In the evaluation by the surface measuring device, the dynamic friction coefficient was measured at a speed of 100 mm mZmin and a load of 100 g using a surface property measuring device (HEIDON-14N). The surface to be rubbed was measured by setting a sample film coated with Teflon tape on the upper side and polyurethane coating on the lower side.

【table 1】 By finger to salt coagulation liquid

Test latex film Stability Water resistance Slip property Dynamic friction coefficient Untreated D 0.52 Corn starch spraying A 0.15 (B1) obtained in Example 1 was applied. Stability No abnormality B 0.17 Obtained in Example 2 ( Apply B2) Stable No abnormality B 0.19 Apply (B3) obtained in Example 3 Stable No abnormality C 0.25 Apply (B4) obtained in Example 4 Stable No abnormality C 0.30 (B5) obtained in Example 5 was applied. Stability No defect B 0.17 (C1) obtained in Comparative Example 1 was applied. Aggregate precipitation No defect C 0.30. (C2) obtained in Comparative Example 2 Application Slightly aggregated dissolution C 0.28

As is clear from Table 1, those coated with the polyurethane coating agents (B 1) to (B 5) obtained in Examples 1 to 5 are excellent in stability against salt coagulation liquid and slipperiness. It can be seen that it is. Industrial applicability

As described above, the water-based polyurethane coating agent for dip molded articles of the present invention has good stability against salt coagulation liquid during the production of dip molded articles, and has good adhesion to the rubber layer even in a simple coating process. Thus, a dip-formed product having good lubricating properties can be produced without using a powdery lubricant.

Claims

The scope of the claims

1. A coating agent for coating a dip molded product obtained by dispersing or dissolving a nonionic polyurethane resin in water and containing 3 to 60% by weight of a polyoxyethylene chain based on a solid content.

2. The coating agent according to claim 1, wherein a polyoxyethylene chain is introduced into a side chain of the nonionic polyurethane resin.

3. The coating agent according to claim 1, wherein the polyoxetylene chain is introduced into the main chain terminal of the nonionic polyurethane resin.

4. The coating agent according to claim 1, wherein the nonionic polyurethane resin contains 10 to 70% by weight of a polyoxytetramethylene chain in the main chain of the molecule.

5. The coating agent according to claim 1, wherein the nonionic polyurethane resin is obtained by reacting an alicyclic polyisocyanate compound with an active hydrogen compound.

6. A dip molded product having a coating layer of the coating agent according to claim 1.

7. The dip molded product according to claim 6, wherein the elongation percentage of the coating layer is at least 300%.