JP2003213197A - Coating agent and dip molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a coating agent which can manufacture a dip molded article that is easy to release from a gummy globe, is excellent in blocking resistance, is easy to remove, and is hard to dust, and to provide a dip molded article coated with the coating agent. <P>SOLUTION: There are provided the coating agent comprising a polymeric latex which contains a polymer having a first glass transition temperature (Tg1) in the range of -20-30°C and a polymer having a second glass transition temperature (Tg2) in the range of 60-140°C, and the dip molded article coated with the coating agent. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating agent and a dip-formed product, more specifically, a dip-formed product which is easy to release from a hand mold, has excellent blocking resistance, is easy to put on and take off, and is hard to drop powder. And a dip-molded article obtained by coating the coating agent.

[0002]

2. Description of the Related Art Typical examples of dip-molded articles made of natural rubber latex or synthetic rubber latex include rubber gloves and finger cots. The inner surface of these rubber gloves is sticky, so they are hard to slip,
It is difficult to put on and take off. Various modifications have been made to these rubber gloves so that they can be easily put on and taken off. That is, in general, in order to prevent tackiness, a method of spraying powder such as talc on the inner surface of the glove or a method of forming irregularities on the inner surface of the glove by chlorination treatment is performed. . However, in the method of spraying the powder, the powder falls off from the gloves during attachment / detachment or during wearing. Therefore, when this type of rubber glove is used for medical gloves (surgical gloves), The surgical site may become contaminated resulting in post-operative infection. Further, the chlorination treatment has problems that the process is difficult to control, the detachability is not sufficiently improved, and that chlorine is used, so that the load on the environment is large.

Alternatively to these methods, by forming an elastomeric layer containing particulates on the inside of the glove,
The device is designed to enhance the putting on and taking off of gloves. For example, Japanese Patent Publication No. 60-6655 proposes a medical glove in which an elastomer layer containing a carboxylated styrene-butadiene latex in which starch particles are dispersed as a main component is formed.

Further, Japanese Patent Application Laid-Open No. 11-61527 proposes a rubber glove in which an elastomer layer is formed by an aqueous dispersion liquid containing a synthetic rubber latex and an organic filler which are not coagulated by a coagulant contained in the glove body. Examples of the synthetic rubber latex include styrene-butadiene rubber latex and acrylonitrile-butadiene rubber latex, and examples of the organic filler include crosslinked methyl methacrylate polymer particles and urethane resin particles.

Further, Japanese Patent Application Laid-Open No. 8-249430 proposes a rubber glove in which an elastomer layer containing thermoplastic resin particles, rubber latex and blocked isocyanate as a main component is formed. As the rubber latex, natural rubber latex, Examples of the chloroprene rubber latex and the thermoplastic resin particles include ethylene-acrylic acid copolymer resin particles and ethylene-methacrylic acid copolymer particles.

In the methods described in these publications, although the detachability is improved to some extent, there is a problem that the insides of the gloves stick to each other and are difficult to peel off. Further, in all cases, the gloves having the elastomer layer formed on the outside are turned over and released from the hand mold to manufacture rubber gloves having the elastomer layer on the inside. However, in such a method, since the frictional force when the elastomer layers rub against each other during release is large, it is difficult to release the mold, and in particular, in order to improve productivity, the mold release is performed at a high hand mold temperature. If it is tried, there is a problem that it becomes more difficult to release the mold.

[0007]

In view of the above circumstances, an object of the present invention is to produce a dip-molded product which is easy to release from a hand mold, has excellent blocking resistance, is easy to put on and take off, and is hard to drop powder. It is intended to provide a coating agent and a dip-molded article obtained by coating the coating agent.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that a polymer having a relatively low glass transition temperature and a polymer having a relatively high glass transition temperature. By using a coating agent containing a polymer latex containing a coalesced product, it is possible to obtain a dip-molded product that is easily released from the hand mold, has excellent blocking resistance, is easy to put on and take off, and does not easily fall off powder. The present invention has been completed based on this finding.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The coating agent of the present invention comprises a polymer having a first glass transition temperature (Tg1) in the range of −20 to 30 ° C. and 6
The second glass transition temperature (Tg in the range of 0 to 140 ° C.)
And a polymer latex containing a polymer having 2).

The polymer latex used in the present invention is -2.
A polymer having a first glass transition temperature (Tg1) in the range of 0 to 30 ° C, preferably -15 to 25 ° C, more preferably -10 to 20 ° C, and 60 to 140 ° C, preferably 70 to 130 ° C. And more preferably a polymer having a second glass transition temperature (Tg2) in the range of 80 to 120 ° C. If the temperature of Tg1 is too low, it is difficult to release from the mold, it is difficult to attach / detach, and the blocking resistance is inferior. If the temperature of Tg2 is too low, it is difficult to release from the mold, it is difficult to attach / detach, and the blocking resistance is inferior.

The polymer latex used in the present invention has a Tg of
Even if it is a mixture of a polymer latex having 1 and a polymer latex having Tg2, a polymer having Tg1 and a polymer having Tg2 exist in one particle, that is, a so-called heterophase structure type. It may be a polymer latex. A polymer having Tg1 and a Tg1 in that they are more easily attached and detached, less likely to fall off powder, and have excellent blocking resistance.
It is preferably a polymer latex of a so-called different phase structure type in which the polymer having g2 is present in one particle.

The polymer latex used in the present invention is usually obtained by polymerizing a monomer in an aqueous medium in the presence of a dispersion stabilizer.

As the aqueous medium, for example, methanol,
Water-soluble organic solvents such as ethanol, isopropanol and water, and mixtures thereof. The amount of the aqueous medium used is preferably 100 to 500 parts by weight, more preferably 150 to 300 parts by weight, based on 100 parts by weight of the monomer.
Parts by weight.

Examples of the dispersion stabilizer include cellulose derivatives such as alkyl cellulose and hydroxyalkyl cellulose; starch derivatives such as alkyl starch and carboxymethyl starch; water-soluble polymers such as gum arabic, polyalkylene glycol and polyvinyl alcohol, and emulsions. Low molecular weight surfactants commonly used in polymerization are used.
Among them, polyvinyl alcohol is preferable because it is easier to put on and take off, powder does not easily fall off, and blocking resistance is excellent.

Any polyvinyl alcohol may be used as long as it has a vinyl alcohol unit, is substantially water-soluble, and gives a stable polymer latex when used during polymerization.

Polyvinyl alcohol is usually a vinyl ester polymer obtained by polymerizing a vinyl monomer mainly composed of a vinyl ester monomer by a conventionally known method (ie, a homopolymer of a vinyl ester monomer, It can be easily obtained by saponifying a copolymer of two or more vinyl ester monomers and a copolymer of a vinyl ester monomer and another ethylenically unsaturated monomer) by a conventional method. In addition, a polymer in which a modifying group such as a mercapto group is introduced into the side chain or terminal of the polymer can also be used.

Any vinyl ester monomer can be used as long as it can be radically polymerized, and specific examples thereof include vinyl formate, vinyl acetate, vinyl propionate, isopropenyl acetate, vinyl valerate and vinyl caprate. , Vinyl laurate, vinyl stearate, vinyl benzoate, vinyl versatate, vinyl pivalate and the like. Of these, vinyl acetate, which is industrially manufactured and inexpensive, is preferable.

Other ethylenically unsaturated monomers copolymerizable with the vinyl ester monomer include olefins such as ethylene, propylene, 1-butene and isobutene; ethylenically unsaturated monomers such as acrylic acid and methacrylic acid. Monocarboxylic acids; ethylenically unsaturated polyvalent carboxylic acids such as fumaric acid, maleic acid, itaconic acid, maleic anhydride, phthalic anhydride, trimetic acid anhydride, itaconic anhydride and their acid anhydrides; methyl acrylate, acrylic acid Ethyl, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n methacrylate
Ethylenically unsaturated monocarboxylic acid ester such as butyl and 2-ethylhexyl methacrylate; ethylenically unsaturated polycarboxylic acid ester such as dimethyl fumarate, diethyl maleate and diisopropyl itaconate; methyl vinyl ether, n-propyl vinyl ether, Vinyl ethers such as isopropyl vinyl ether, n-butyl vinyl ether and isobutyl vinyl ether; ethylenically unsaturated nitriles such as acrylonitrile and methacrylonitrile; halogenated vinyls such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride; ethylene sulfonic acid , Sulfonic acid group-containing monomers such as allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid; vinyl trimethoxysilane and other vinyl Silane monomer; 3-acrylamidopropyl trimethylammonium chloride, 3-methacrylamidopropyltrimethylammonium chloride quaternary ammonium group-containing monomers, and the like.

From the viewpoint of water solubility, the degree of saponification of polyvinyl alcohol is preferably 40 to 100 mol%, more preferably 60 to 99 mol%, particularly preferably 80 to 100 mol%.
It is 95 mol%. If the degree of saponification is too low, the dispersion stability of the polymer latex particles will decrease.

The average degree of polymerization of polyvinyl alcohol is preferably 50 to 8,000, more preferably 100 to 8,000.
6,000, particularly preferably 300 to 3,000. If the degree of polymerization is too low, the polymerization stability is insufficient. Conversely, if it is too high, it is difficult to remove the reaction heat due to the increase in the viscosity of the polymerization system, the viscosity of the obtained latex becomes too high, and the handling becomes difficult. There is a problem such as becoming.

The amount of the dispersion stabilizer used is preferably 0.1 to 60 parts by weight, more preferably 0.5 to 20 parts by weight, and particularly preferably 1 to 10 parts by weight, based on 100 parts by weight of the monomer. Is. If this amount is too small, there is a problem that the polymerization stability is insufficient and a large amount of agglomerates are generated during the polymerization, or the mechanical stability of the latex obtained is lowered, and if it is too large, the polymerization is Problems such as difficulty in removing reaction heat due to increase in system viscosity and viscosity of the obtained latex are too high and handling becomes difficult.

When polyvinyl alcohol is used as the dispersion stabilizer, the amount of the low-molecular-weight surfactant used is preferably 0.5 part by weight or less based on 100 parts by weight of the monomer. It is preferably 0.2 parts by weight or less, and particularly preferably not used.

As the monomer used for producing the polymer latex in the present invention, any radical-polymerizable monomer can be used, and examples thereof include a conjugated diene monomer and an ethylenically unsaturated carboxylic acid monomer. Examples thereof include a monomer, an aromatic vinyl monomer, an ethylenically unsaturated carboxylic acid ester monomer, an ethylenically unsaturated carboxylic acid amide monomer, and an ethylenically unsaturated nitrile monomer. Of these, aromatic vinyl monomers and ethylenically unsaturated carboxylic acid ester monomers are preferable, and ethylenically unsaturated carboxylic acid ester monomers are more preferable.

As the conjugated diene monomer, for example, 1,
3-butadiene, isoprene, 2,3-dimethyl-1,
3-butadiene, 1,3-pentadiene, chloroprene and the like can be mentioned. Among these, 1,3-butadiene is preferable.

Examples of the ethylenically unsaturated carboxylic acid monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; ethylene such as fumaric acid, maleic acid, itaconic acid and butenetricarboxylic acid. Unsaturated polycarboxylic acid; monoethyl maleate,
Partial esterified products of ethylenically unsaturated polyvalent carboxylic acids such as monomethyl itaconate may be mentioned.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyltoluene, chlorostyrene and hydroxymethylstyrene.

Examples of the ethylenically unsaturated carboxylic acid ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Butyl (meth) acrylate, (meth) acrylic acid-2-
Ethylhexyl, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, methoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, cyanomethyl (meth) acrylate, 2- (meth) acrylate Ethylenically unsaturated monocarboxylic acid ester monomers such as cyanoethyl, 2-hydroxyethyl (meth) acrylate, and glycidyl (meth) acrylate; ethylenically unsaturated polycarboxylic acid monomers such as dibutyl maleate, dibutyl fumarate, and diethyl maleate. Examples thereof include carboxylic acid esters. Of these, an ethylenically unsaturated monocarboxylic acid ester monomer is preferable.

Examples of the ethylenically unsaturated carboxylic acid amide monomer include (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide and N-methoxymethyl (meth).
Examples include acrylamide.

Examples of the ethylenically unsaturated nitrile monomer include (meth) acrylonitrile, fumaronitrile, α-chloroacrylonitrile, α-cyanoethylacrylonitrile and the like.

These monomers can be used alone or in combination of two or more kinds.

As the monomer, a monomer (M1) capable of forming a polymer having Tg1 and a monomer (M2) capable of forming a polymer having Tg2 are appropriately selected. Each monomer may be a single compound or a mixture of two or more monomers.

Preferred monomers for M1 are n-butyl acrylate (BA) and methyl methacrylate (MMA).
And a mixture thereof. The quantity ratio is BA / MMA
Is preferably 70/30 to 30/70, more preferably 60/40 to 40/60, particularly preferably 55/45.
45/55. As a preferable monomer of M2,
Examples include a mixture of BA and MMA or MMA alone. The quantity ratio is such that BA / MMA is preferably 0/10.
0-20 / 80, more preferably 0 / 100-15 / 8
5, particularly preferably 1/99 to 10/90.

The polymer latex used in the present invention is preferably obtained by polymerizing M1 and M2 in two steps in the presence of a dispersion stabilizer in an aqueous medium. At this time, M1 may be polymerized and then M2 may be polymerized.
After polymerizing, M1 may be polymerized. Among them, M2
A polymer latex obtained by polymerizing M1 and then M1 is preferable.

The amount ratio of M1 and M2 is preferably M1 / M2, preferably 20/80 to 80/20, more preferably 25/7.
5 to 70/30, particularly preferably 30/70 to 50/5
It is 0.

In the case of carrying out the polymerization in two stages, the polymerization conversion in the first stage is preferably 80% by weight or more, more preferably 90% by weight.
The content is preferably at least wt%, particularly preferably at least 95 wt%.

The method of using the dispersion stabilizer is not particularly limited, but after the dispersion stabilizer is added to the polymerization reactor in advance or a part of the dispersion stabilizer is added to the polymerization reactor to start the polymerization reaction. The balance can be added to the polymerization reactor, or the dispersion stabilizer can be continuously or intermittently added to the polymerization reactor at the same time as the start of the polymerization reaction.

The method of adding the monomer is not particularly limited, but a method of adding the monomer to the polymerization reactor in advance, or a part of the monomer is added to the polymerization reactor to start the polymerization reaction and the rest is added. Can be used in the polymerization reactor, or a method in which the monomer is continuously or intermittently added to the polymerization reactor almost at the same time as the initiation of the polymerization reaction. Among them, the method of continuously adding the monomer to the polymerization reactor at substantially the same time as the start of the polymerization reaction is preferable.

The method of adding the monomer and the dispersion stabilizer is not particularly limited, but they may be added separately, and a monomer emulsion obtained by mixing the monomer, the dispersion stabilizer and water may be added. You may add in the form. When the monomer and the dispersion stabilizer are added separately, it is preferable to start the addition of both at substantially the same time, and it is preferable to finish the addition of both at almost the same time. Among them, a method of continuously adding to a polymerization reactor in the form of a monomer emulsion obtained by mixing a monomer, a dispersion stabilizer and water is preferable.

The addition rate in the case of continuously adding the monomers is not particularly limited, but it is preferable to control so as to keep the polymerization conversion rate during the reaction at 10% by weight or more. A preferable polymerization conversion rate during the reaction is 20% by weight or more, and more preferably 30% by weight or more. If the addition rate of the monomer is too fast, the polymerization conversion rate becomes low, and coarse particles are likely to occur.

As the polymerization initiator used for polymerizing the above-mentioned monomers, those usually used in emulsion polymerization can be used. Specific examples of the polymerization initiator include water-soluble peroxides such as potassium persulfate, ammonium persulfate and hydrogen peroxide; oil-soluble peroxides such as t-butyl hydroperoxide, benzoyl peroxide and di-t-butyl peroxide. Oxides; redox initiators obtained by combining peroxides with various reducing agents such as sodium bisulfite can be mentioned. Of these, water-soluble peroxides are preferable, and persulfates such as potassium persulfate and ammonium persulfate are more preferable. The amount of the polymerization initiator used is usually 0.05 to 3 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the monomer.

The method of adding the polymerization initiator is not particularly limited, but after the whole amount is added to the polymerization reactor before the initiation of the polymerization or a part of the polymerization initiator is introduced into the polymerization reactor before the initiation of the polymerization, The balance can be added at a specific time, or a part of the mixture can be added to the polymerization reactor before the start of polymerization to start the polymerization, and then the balance can be continuously or intermittently added to the polymerization reaction system.

In the above-mentioned method for producing a polymer latex, when polyvinyl alcohol is used as the dispersion stabilizer, it is preferable to carry out the polymerization in the presence of a water-soluble alcohol. The alcohol that can be used in this case is not particularly limited, but monohydric or polyhydric water-soluble alcohols are preferable. Specific examples of such alcohol include, for example, methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, glycerol and the like. The amount of alcohol used is preferably 1 to 50 parts by weight, more preferably 3 to 20 parts by weight, based on 100 parts by weight of the monomer.

The method of adding the alcohol is not particularly limited, but the whole amount is added to the polymerization reactor before the initiation of the polymerization, or a part of the alcohol is added to the polymerization reactor before the initiation of the polymerization to initiate the polymerization, and then the remaining portion is left. It may be added at a specific time, or a part thereof may be charged into the polymerization reactor before the start of the polymerization to start the polymerization, and the rest may be continuously or intermittently added to the polymerization reaction system. Among them, the method of adding the whole amount to the polymerization reactor before the initiation of the polymerization is preferable.

A chain transfer agent may be used in the polymerization, although it is not essential. As the chain transfer agent, for example,
Mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-stearyl mercaptan; mercaptos such as thioglycolic acid, thiomalic acid and 2-ethylhexyl thioglycolate. Compounds having a group; xanthogen compounds such as dimethylxanthogen disulfide and diisopropylxanthogen disulfide; α-methylstyrene dimer, 2,4-diphenyl-4-methyl-1-pentene, 2,4-diphenyl-4-methyl-2 -Α-methylstyrene dimers such as pentene and 1,1,3-trimethyl-3-phenylindane; dichloromethane,
Halogenated hydrocarbons such as dibromomethane, carbon tetrachloride and carbon tetrabromide; vinyl ethers such as α-benzyloxystyrene, α-benzyloxyacrylonitrile and α-benzyloxyacrylamide; triphenylethane, pentaphenylethane and the like. . The amount of chain transfer agent used is usually 100 parts by weight of the monomer,
It is 0.01 to 5 parts by weight. The method of adding the chain transfer agent is
It is not particularly limited, and may be added all at once or may be added intermittently or continuously to the polymerization reaction system.

The polymerization temperature is not particularly limited, but is usually 0.
~ 100 ° C, preferably 50-95 ° C.

After reaching a predetermined polymerization conversion rate, the polymerization is stopped. The termination of the polymerization can be performed by adding a polymerization terminator or simply by cooling the polymerization reaction system. The polymerization conversion rate when terminating the polymerization is preferably 90.
The content is at least wt%, more preferably at least 93 wt%, and particularly preferably at least 95 wt%. After stopping the polymerization, unreacted monomers may be removed, if desired.

The polymer latex used in the present invention includes
If necessary, an auxiliary agent such as a chelating agent, a dispersant, a pH adjuster, an antiseptic, a plasticizer and an antifoaming agent may be used together during or after the polymerization.

The volume average particle diameter of the polymer latex is preferably 50 to 5000 nm, more preferably 80 to 2 nm.
000 nm, particularly preferably 100 to 1000 nm. When the average particle size is small, the viscosity tends to increase during the polymerization, which makes the handling difficult. On the other hand, if the average particle size becomes large, it becomes difficult to obtain a uniform coating layer.

The coating agent of the present invention preferably contains the above-mentioned polymer latex and further contains fine particles. The fine particles are not particularly limited, and either inorganic fine particles or organic fine particles may be used. Of these, organic fine particles are preferable.

Examples of the inorganic fine particles include silica, magnesium oxide, titanium dioxide, calcium carbonate and the like. Examples of the organic fine particles include acrylic resin, acrylic-styrene resin, urethane resin, polyamide resin, olefin resin, formaldehyde resin,
Examples thereof include fine particles made of vinyl chloride resin, vinylidene chloride resin, nylon resin, cellulose resin, starch resin and cross-linked products thereof. Among these,
Fine particles of acrylic resin and styrene-acrylic resin are preferable because the glass transition temperature of the resin can be adjusted relatively freely. These fine particles may be used alone or in combination of two or more kinds.

The glass transition temperature of the resin constituting the organic fine particles is usually 60 to 140 ° C., preferably 70 to 120.
C., more preferably 80 to 110.degree. If the glass transition temperature is too low, the blocking resistance tends to be poor,
On the contrary, if it is too high, powder tends to fall off.

The volume average particle diameter of the fine particles is usually 1-5.
It is 0 μm, preferably 3 to 30 μm. When the volume average particle diameter of the fine particles is within this range, it is easier to put on and take off and the wearing feeling is good.

The shape of the fine particles is not particularly limited, but is preferably spherical. When the fine particles are spherical, there are advantages such that the feel of the glove when worn is good, and the particles are less likely to be subjected to force when detached and attached, and detachment is reduced.

The blending ratio of the polymer latex and the fine particles is
The fine particles are usually 10 to 200 parts by weight, preferably 20 to 15 parts by weight based on 100 parts by weight of the polymer latex solid content.
It is 0 part by weight, more preferably 40 to 100 parts by weight.
When the compounding ratio is within this range, it is easy to release the mold, and the balance between blocking resistance, desorption property and powder falling resistance is excellent.

If desired, the coating agent of the present invention may further contain a thickener, a wetting agent, a defoaming agent, a pH adjusting agent, an antiaging agent and the like. Further, a water-affinity solvent such as alcohols, cellosolves, glycols, and glycerin may be appropriately blended depending on the purpose of improving the drying property and the film forming property.

The solid content of the coating agent is usually 1
-15 wt%, preferably 3-12 wt%, more preferably 5-10 wt%.

Dip-molded product The dip-molded product of the present invention comprises a dip-molded product coated with the coating agent. The coating amount is not particularly limited, but is a solid content per unit surface area, preferably 0.1 to ² g / m ² , and more preferably 0.15 to 5 g / m ² .
It is 1.5 g / m ² .

The dip-molded article is not particularly limited, but gloves, finger sack obtained by dip-molding on a molding die by a conventional dip-molding method such as a direct dipping method, a coagulation dipping method, or a heat-sensitive dipping method. And so on. The dip-molded product is not particularly limited, but a product made of natural rubber latex or synthetic rubber latex can be used. Examples of the synthetic rubber latex include styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, carboxy-modified acrylonitrile-butadiene copolymer latex, and the like.
Among these, the coating agent of the present invention, in particular,
It can be suitably used for a glove obtained by a coagulation dipping method using a carboxy-modified acrylonitrile-butadiene copolymer latex.

The mold used in the dip molding is, for example, porcelain, earthenware, metal, glass,
And those made of plastic. When the dip molded product is a glove, the mold has a shape corresponding to the contour of a human hand, and a shape from the wrist to the fingertip, depending on the intended use of the glove to be manufactured,
Various shapes such as a shape from the elbow to the fingertip can be used.

Examples of the method for coating the dip-molded product with the coating agent include a method of immersing the dip-molded product in the coating agent and a method of applying the coating agent to the dip-molded product. Among them, the method of immersing the dip-molded product in the coating agent is preferable because a uniform surface treatment layer can be easily obtained.

The coating may be performed subsequent to the dip molding in the manufacturing process of the dip molded product, or
The completed dip-molded product may be processed later. In either case, after coating, it is dried to obtain a dip-molded article. Further, the coating may be performed on only one side of the dip-molded article, on both sides thereof, or on the entire surface or a part thereof.

The dip-molded product of the present invention has a thickness of about 0.
1 to about 3 mm can be manufactured, especially the thickness is about 0.1
It can be suitably used for thin things of about 0.3 mm. Specifically, medical supplies such as baby bottle nipples, droppers, conduits, water pillows; toys and exercise equipment such as balloons, dolls and balls; industrial products such as pressure molding bags and gas storage bags; surgery, Household, agricultural, fishing and industrial gloves; such as finger cots. In particular, it is suitable for thin surgical gloves.

[0063]

EXAMPLES The present invention will now be described in more detail by way of examples. In the examples, "%" and "parts" are based on weight unless otherwise specified.

(Evaluation of Polymer Latex and Fine Particles) (1) Volume Average Particle Diameter (μm) Coulter LS230 (Coulter Particle Size Measuring Instrument)
It was measured at. (2) Glass transition temperature (° C) In the case of polymer latex, the polymer latex is cast on a glass plate with a frame and left in a constant temperature and humidity chamber at a temperature of 20 ° C and a relative humidity of 65% for 48 hours to obtain a film. This was used as a sample. In the case of organic fine particles, an aqueous dispersion of organic fine particles was cast on a glass plate with a frame, allowed to stand in a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 65% for 48 hours, and dried to obtain a sample. The glass transition temperature of the sample was measured using a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd .: SSC5200) under the conditions of a starting temperature of -100 ° C and a heating rate of 5 ° C / min.
It was measured according to JIS K 7121.

(Physical properties of gloves) (3) Releasability from hand mold The hand mold before vulcanization and before the gloves are peeled off is put on the load cell of a Tensilon tensile tester (UTM-250 type: manufactured by Toyo Baldwin Co., Ltd.). Was hung so that it faces down. Then, the temperature of the palm portion of the hand mold is measured with a laser-type non-contact thermometer (THI440N: manufactured by TASCO),
When the temperature reached 70 ° C., the gloves were peeled off from the hand mold while being inverted. At this time, the maximum value of the stress measured by the load cell is defined as the mold release stress. This test was performed 5 times, and the average value of the three releasing stresses excluding the maximum value and the minimum value of the five releasing stresses was taken as the average releasing stress. The smaller the average mold release stress, the easier the mold release from the hand mold.

(4) Removability The degree of difficulty when putting on and taking off gloves while the inner surface is dry was evaluated according to the following criteria.

(5) Anti-blocking property A glove having a surface-treated layer on the inside was superposed by applying a load of 9.8 KPa from the outside. Temperature 60
After leaving the gloves in a constant temperature and humidity oven at a temperature of 95% and a humidity of 95% for 24 hours, the gloves were taken out, and the ease of peeling when the overlapped portions were peeled off with both hands was evaluated according to the following criteria. Evaluation criteria Blocking resistance A: Can be peeled off without difficulty. Blocking resistance B: Peeling requires force. Blocking resistance C: Not peelable. (6) Powder falling resistance According to ASTM D6124-97, the amount of released resin (m
g) was measured. The smaller this amount is, the more excellent the powder falling resistance is.

(Example 1) (Production of polymer latex) In a pressure vessel equipped with a stirrer,
45 parts of deionized water, 2.5 parts of butyl acrylate, 47.5 parts of methyl methacrylate, and 2.5 parts of polyvinyl alcohol (PVA-205, manufactured by Kuraray Co., Ltd., average polymerization degree 500, saponification degree 88 mol%). The mixture was added and stirred to obtain a monomer emulsion I. In another pressure vessel equipped with a stirrer, 45 parts of deionized water, 26.5 parts of butyl acrylate, 22.5 parts of methyl methacrylate, 1 part of 2-hydroxyethyl acrylate, and polyvinyl alcohol (PVA-224,
Kuraray Co., Ltd., average polymerization degree 2400, saponification degree 88 mol%) 1.5 parts was added and stirred to obtain a monomer emulsion II.

Separately, 70 parts of deionized water and 8 parts of ethanol were charged into a pressure resistant reactor equipped with a stirrer and the temperature was adjusted to 80.
The monomer emulsion I was continuously added to the reaction vessel while the temperature was raised to 80 ° C. and maintained at 80 ° C., and then 0.3 parts of potassium persulfate was dissolved in 10 parts of deionized water. The agent solution was added. The continuous addition of the monomer emulsion I was completed over 2 hours. After the addition was completed, post-reaction was carried out for 40 minutes. The polymerization conversion rate at this time was 99%. Subsequently, the monomer emulsion II was continuously added to the reaction vessel over 2 hours, and after the addition was completed, the reaction was further continued for 2 hours. After that, the reaction was terminated by cooling. The polymerization conversion rate at this time was 98%. After removing the unreacted monomer, the latex was adjusted to obtain a polymer latex A having a solid content concentration of 40%. The volume average particle size of the obtained polymer latex A was 350 nm, and the glass transition temperatures thereof were −2 ° C. and 94 ° C.

(Coating agent) The solid content concentration of the polymer latex A was adjusted to 8% to obtain a coating agent A1.

(Production of Dip Molded Article) Sulfur 10 parts, zinc oxide 15 parts, titanium oxide 7 parts and potassium hydroxide 0.
Solid content of 5 prepared by mixing 3 parts and 32 parts of water
7 parts of a 0.2% vulcanizing agent dispersion was mixed with 333 parts of a carboxy-modified acrylonitrile-butadiene copolymer latex for dip molding having a solid content of 30% to obtain a dip having a solid content of 30.4%. A molding compound liquid was obtained.

On the other hand, 20 parts of calcium nitrate, 0.05 part of polyoxyethylene octyl phenyl ether as a nonionic emulsifier and 80 parts of deionized water were mixed to prepare a coagulant solution having a solid content of 20.4%. A glove mold made of porcelain was immersed in the above for 1 minute, pulled up, and then dried at 50 ° C. for 3 minutes to adhere the coagulant to the glove mold.

Next, the glove mold to which the coagulant is attached is dipped in the above dip molding compound solution for 10 seconds and pulled up to 6
It was dried at 0 ° C. for 5 minutes, immersed in warm water at 50 ° C. for 5 minutes, and further dried at 60 ° C. for 5 minutes.

Then, the glove type is applied to the above coating agent 10 times.
After dipping for 2 seconds and pulling up, it was dried at 70 ° C. for 10 minutes with a drier, and further vulcanized at 120 ° C. for 25 minutes to obtain a solid coating on the surface of the glove mold. Finally, the solid coating was peeled off while being inverted from the mold to obtain a rubber glove having a coating layer inside. The thickness of this rubber glove was 0.15 mm, and the coating amount was 1 g / m ² . The properties of this glove were evaluated and the results are shown in Table 1.

Example 2 The procedure of Example 1 was repeated, except that the monomer mixture I, the monomer mixture II, and the respective monomer mixture continuous addition times shown in Table 1 were changed. A combined latex B was obtained. The volume average particle diameter and glass transition temperature are shown in Table 1. The same procedure as in Example 1 was carried out except that the polymer latex B was used instead of the polymer latex A. Table 1 shows the characteristics of the dip-molded product.

(Comparative Examples 1 and 2) Except that the monomer mixture I and the monomer mixture II shown in Table 1 were changed,
Polymer latexes C and D were obtained in the same manner as in Example 1. Table 1 shows the volume average particle diameter and the glass transition temperature thereof. The same procedure as in Example 1 was carried out except that polymer latexes C and D were used instead of polymer latex A. Table 1 shows the characteristics of the dip-molded product.

Comparative Example 3 A polymer latex E was obtained in the same manner as in Example 1 except that the monomer mixture I shown in Table 1 was used and polymerization was carried out in one stage. The volume average particle diameter and glass transition temperature are shown in Table 1. Polymer latex A
Example 1 was repeated except that the polymer latex E was used instead of. Table 1 shows the characteristics of the dip-molded product.

[0078]

[Table 1]

The following can be seen from Table 1. The coating agent C1 using the polymer latex C having Tg1 higher than the range specified in the present invention is easy to release from the mold, and is excellent in detachability and blocking resistance, but is inferior in powder falling resistance (Comparative Example 1). The coating agent D1 using the polymer latex D having a Tg2 lower than the range specified in the present invention has good powder removal resistance, but is difficult to release, and is inferior in detachability and blocking resistance (Comparative Example 2). . Coating agent E using polymer latex E having no two glass transition temperatures
No. 1 is difficult to release, and is inferior in detachability, blocking resistance and powder falling resistance (Comparative Example 3). Compared with these, the coating agents A1 and B1 using the polymer latexes A and B within the range specified in the present invention are easy to release from the mold, and are excellent in detachability, blocking resistance and powder falling resistance (implementation). Examples 1 and 2).

(Production of Organic Fine Particles) 2.1 parts of polyvinyl alcohol having an average degree of polymerization of 500 and a saponification degree of 88 mol% was dissolved in 200 parts of deionized water, and styrene 92.
8 parts, butyl acrylate 7 parts, divinylbenzene 0.2
Solution, 0.9 parts of t-dodecyl mercaptan and 5 parts of benzoyl peroxide (BPO) were added, and then a homogenizer treatment was performed to prepare a fine dispersion liquid. This was transferred to a reaction vessel equipped with a stirrer capable of controlling temperature, and after nitrogen substitution, the temperature was raised to 90 ° C. to initiate polymerization. After 6 hours, the reaction was terminated by cooling. The polymerization conversion rate at this time was 97%. After removing unreacted monomers, an organic fine particle aqueous dispersion having a solid content concentration of 30% was obtained.
The volume average particle diameter of the organic fine particles was 4.6 μm, and the glass transition temperature of the polymer was 92 ° C.

(Example 3) 100 parts (solid content) of polymer latex A and 55 parts (solid content) of the above organic fine particles were mixed to prepare a coating solution A2 having a solid content concentration of 8%. Got Instead of the coating agent A1,
A dip-molded article was obtained in the same manner as in Example 1 except that the coating agent A2 was used. Table 2 shows the characteristics of the dip-molded product.

(Example 4 and Comparative Example 4) The same procedure as in Example 3 was carried out except that the formulation shown in Table 2 was changed. Table 2 shows the characteristics of the dip-molded product.

[0083]

[Table 2]

The following can be seen from Table 2. The coating agent E2, which uses polymer latex E having no two glass transition temperatures and is mixed with organic fine particles, has excellent removability, but has insufficient blocking resistance, is difficult to release, and is resistant to powder falling. Inferior in sex (Comparative Example 4). Compared to this,
Polymer latexes A and B within the range specified in the present invention
Coating agent A2 containing organic fine particles
B2 and B2 are easily released from the mold, and are excellent in detachability, blocking resistance, and powder falling resistance (Examples 3 and 4).

[0085]

According to the present invention, it is easy to release from the hand mold,
It is possible to obtain a coating agent which has excellent blocking resistance, is easy to put on and take off, and is capable of producing a powdered article which is hard to fall off, and a dip molded article obtained by coating the coating agent.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08F 2/44 C08F 2/44 C 261/04 261/04 C09D 5/02 C09D 5/02 121/02 121 / 02 // C09D 129/04 129/04 F-term (reference) 3B033 AB09 AC03 4F205 AC05 AH70 AR06 GA08 GB01 GC01 GE24 GF03 GF24 4J011 BB02 KA16 KB29 4J026 AA30 BA05 BA06 BA24 BA27 BA31 BA32 BA34 BA36 BA45 BA04 BA47 BA49 BA47 BA47 BA49 DB08 DB14 GA06 4J038 CA021 CA051 CA061 CA081 CB002 CC001 CC062 CD032 CE022 CG001 CG002 CG121 CG161 CG171 CH031 CH082 CH191 DG002 HA186 HA216 HA286 HA446 KA08 KA09 MA08 MA10 MA13 PB02

Claims (10)

[Claims] 1. A polymer having a first glass transition temperature (Tg1) in the range of −20 to + 30 ° C. and 60 to 140.
A coating agent containing a polymer latex containing a polymer having a second glass transition temperature (Tg2) in the range of ° C. 2. The coating agent according to claim 1, wherein the polymer latex is obtained by polymerizing a monomer in the presence of polyvinyl alcohol in an aqueous medium. 3. A monomer capable of forming a polymer, wherein the polymer latex has a first glass transition temperature (Tg1) in the range of −20 to + 30 ° C. in the presence of polyvinyl alcohol in an aqueous medium ( 3. A compound obtained by polymerizing M1) and a monomer (M2) capable of forming a polymer having a second glass transition temperature (Tg2) in the range of 60 to 140 ° C. in two stages. The coating agent described. 4. The amount ratio of M1 / M2 is 20/80 to 80 /.
The coating agent according to claim 3, which is 20. 5. A monomer (M2) capable of forming a polymer, wherein the polymer latex has a second glass transition temperature (Tg2) in the range of 60 to 140 ° C. in the presence of polyvinyl alcohol in an aqueous medium. ), Then -20 to
First glass transition temperature (Tg1) in the range of + 30 ° C
The coating agent according to claim 3, which is obtained by polymerizing a monomer (M1) capable of forming a polymer having a. 6. The coating agent according to claim 1, further comprising fine particles. 7. The coating agent according to claim 1, which is for a dip-molded product. 8. The coating agent according to claim 7, wherein the dip-molded article is a rubber glove. 9. A dip-molded article coated with the coating agent according to claim 1. 10. The dip-molded article according to claim 9, which is a rubber glove.